xref: /freebsd/sys/netinet/tcp_stacks/rack.c (revision 32cc4beb0a8c3cadc0de4c255ba512fd7b196607) 
1 /*-
2  * Copyright (c) 2016-2020 Netflix, Inc.
3  *
4  * Redistribution and use in source and binary forms, with or without
5  * modification, are permitted provided that the following conditions
6  * are met:
7  * 1. Redistributions of source code must retain the above copyright
8  *    notice, this list of conditions and the following disclaimer.
9  * 2. Redistributions in binary form must reproduce the above copyright
10  *    notice, this list of conditions and the following disclaimer in the
11  *    documentation and/or other materials provided with the distribution.
12  *
13  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
14  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
15  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
16  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
17  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
18  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
19  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
20  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
21  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
22  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
23  * SUCH DAMAGE.
24  *
25  */
26 
27 #include <sys/cdefs.h>
28 #include "opt_inet.h"
29 #include "opt_inet6.h"
30 #include "opt_ipsec.h"
31 #include "opt_ratelimit.h"
32 #include "opt_kern_tls.h"
33 #if defined(INET) || defined(INET6)
34 #include <sys/param.h>
35 #include <sys/arb.h>
36 #include <sys/module.h>
37 #include <sys/kernel.h>
38 #ifdef TCP_HHOOK
39 #include <sys/hhook.h>
40 #endif
41 #include <sys/lock.h>
42 #include <sys/malloc.h>
43 #include <sys/mutex.h>
44 #include <sys/mbuf.h>
45 #include <sys/proc.h>		/* for proc0 declaration */
46 #include <sys/socket.h>
47 #include <sys/socketvar.h>
48 #include <sys/sysctl.h>
49 #include <sys/systm.h>
50 #ifdef STATS
51 #include <sys/qmath.h>
52 #include <sys/tree.h>
53 #include <sys/stats.h> /* Must come after qmath.h and tree.h */
54 #else
55 #include <sys/tree.h>
56 #endif
57 #include <sys/refcount.h>
58 #include <sys/queue.h>
59 #include <sys/tim_filter.h>
60 #include <sys/smp.h>
61 #include <sys/kthread.h>
62 #include <sys/kern_prefetch.h>
63 #include <sys/protosw.h>
64 #ifdef TCP_ACCOUNTING
65 #include <sys/sched.h>
66 #include <machine/cpu.h>
67 #endif
68 #include <vm/uma.h>
69 
70 #include <net/route.h>
71 #include <net/route/nhop.h>
72 #include <net/vnet.h>
73 
74 #define TCPSTATES		/* for logging */
75 
76 #include <netinet/in.h>
77 #include <netinet/in_kdtrace.h>
78 #include <netinet/in_pcb.h>
79 #include <netinet/ip.h>
80 #include <netinet/ip_var.h>
81 #include <netinet/ip6.h>
82 #include <netinet6/in6_pcb.h>
83 #include <netinet6/ip6_var.h>
84 #include <netinet/tcp.h>
85 #define	TCPOUTFLAGS
86 #include <netinet/tcp_fsm.h>
87 #include <netinet/tcp_seq.h>
88 #include <netinet/tcp_timer.h>
89 #include <netinet/tcp_var.h>
90 #include <netinet/tcp_log_buf.h>
91 #include <netinet/tcp_syncache.h>
92 #include <netinet/tcp_hpts.h>
93 #include <netinet/tcp_ratelimit.h>
94 #include <netinet/tcp_accounting.h>
95 #include <netinet/tcpip.h>
96 #include <netinet/cc/cc.h>
97 #include <netinet/cc/cc_newreno.h>
98 #include <netinet/tcp_fastopen.h>
99 #include <netinet/tcp_lro.h>
100 #ifdef NETFLIX_SHARED_CWND
101 #include <netinet/tcp_shared_cwnd.h>
102 #endif
103 #ifdef TCP_OFFLOAD
104 #include <netinet/tcp_offload.h>
105 #endif
106 #ifdef INET6
107 #include <netinet6/tcp6_var.h>
108 #endif
109 #include <netinet/tcp_ecn.h>
110 
111 #include <netipsec/ipsec_support.h>
112 
113 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
114 #include <netipsec/ipsec.h>
115 #include <netipsec/ipsec6.h>
116 #endif				/* IPSEC */
117 
118 #include <netinet/udp.h>
119 #include <netinet/udp_var.h>
120 #include <machine/in_cksum.h>
121 
122 #ifdef MAC
123 #include <security/mac/mac_framework.h>
124 #endif
125 #include "sack_filter.h"
126 #include "tcp_rack.h"
127 #include "tailq_hash.h"
128 #include "rack_bbr_common.h"
129 
130 uma_zone_t rack_zone;
131 uma_zone_t rack_pcb_zone;
132 
133 #ifndef TICKS2SBT
134 #define	TICKS2SBT(__t)	(tick_sbt * ((sbintime_t)(__t)))
135 #endif
136 
137 VNET_DECLARE(uint32_t, newreno_beta);
138 VNET_DECLARE(uint32_t, newreno_beta_ecn);
139 #define V_newreno_beta VNET(newreno_beta)
140 #define V_newreno_beta_ecn VNET(newreno_beta_ecn)
141 
142 #define	M_TCPFSB	__CONCAT(M_TCPFSB, STACKNAME)
143 #define	M_TCPDO		__CONCAT(M_TCPDO, STACKNAME)
144 
145 MALLOC_DEFINE(M_TCPFSB, "tcp_fsb_" __XSTRING(STACKNAME), "TCP fast send block");
146 MALLOC_DEFINE(M_TCPDO, "tcp_do_" __XSTRING(STACKNAME), "TCP deferred options");
147 MALLOC_DEFINE(M_TCPPCM, "tcp_pcm_" __XSTRING(STACKNAME), "TCP PCM measurement information");
148 
149 struct sysctl_ctx_list rack_sysctl_ctx;
150 struct sysctl_oid *rack_sysctl_root;
151 
152 #define CUM_ACKED 1
153 #define SACKED 2
154 
155 /*
156  * The RACK module incorporates a number of
157  * TCP ideas that have been put out into the IETF
158  * over the last few years:
159  * - Matt Mathis's Rate Halving which slowly drops
160  *    the congestion window so that the ack clock can
161  *    be maintained during a recovery.
162  * - Yuchung Cheng's RACK TCP (for which its named) that
163  *    will stop us using the number of dup acks and instead
164  *    use time as the gage of when we retransmit.
165  * - Reorder Detection of RFC4737 and the Tail-Loss probe draft
166  *    of Dukkipati et.al.
167  * RACK depends on SACK, so if an endpoint arrives that
168  * cannot do SACK the state machine below will shuttle the
169  * connection back to using the "default" TCP stack that is
170  * in FreeBSD.
171  *
172  * To implement RACK the original TCP stack was first decomposed
173  * into a functional state machine with individual states
174  * for each of the possible TCP connection states. The do_segment
175  * functions role in life is to mandate the connection supports SACK
176  * initially and then assure that the RACK state matches the conenction
177  * state before calling the states do_segment function. Each
178  * state is simplified due to the fact that the original do_segment
179  * has been decomposed and we *know* what state we are in (no
180  * switches on the state) and all tests for SACK are gone. This
181  * greatly simplifies what each state does.
182  *
183  * TCP output is also over-written with a new version since it
184  * must maintain the new rack scoreboard.
185  *
186  */
187 static int32_t rack_tlp_thresh = 1;
188 static int32_t rack_tlp_limit = 2;	/* No more than 2 TLPs w-out new data */
189 static int32_t rack_tlp_use_greater = 1;
190 static int32_t rack_reorder_thresh = 2;
191 static int32_t rack_reorder_fade = 60000000;	/* 0 - never fade, def 60,000,000
192 						 * - 60 seconds */
193 static uint32_t rack_pcm_every_n_rounds = 100;
194 static uint32_t rack_pcm_blast = 0;
195 static uint32_t rack_pcm_is_enabled = 1;
196 static uint8_t rack_ssthresh_rest_rto_rec = 0; /* Do we restore ssthresh when we have rec -> rto -> rec */
197 
198 static uint32_t rack_gp_gain_req = 1200;		/* Amount percent wise required to gain to record a round as "gaining" */
199 static uint32_t rack_rnd_cnt_req = 0x10005;		/* Default number of rounds if we are below rack_gp_gain_req where we exit ss */
200 
201 
202 static int32_t rack_rxt_scoreboard_clear_thresh = 2;
203 static int32_t rack_dnd_default = 0;		/* For rr_conf = 3, what is the default for dnd */
204 static int32_t rack_rxt_controls = 0;
205 static int32_t rack_fill_cw_state = 0;
206 static uint8_t rack_req_measurements = 1;
207 static uint32_t rack_rtt_divisor = 2;
208 static int32_t rack_enable_hw_pacing = 0; /* Due to CCSP keep it off by default */
209 static int32_t rack_hw_rate_caps = 0; /* 1; */
210 static int32_t rack_hw_rate_cap_per = 0;	/* 0 -- off  */
211 static int32_t rack_hw_rate_min = 0; /* 1500000;*/
212 static int32_t rack_hw_rate_to_low = 0; /* 1200000; */
213 static int32_t rack_hw_up_only = 0;
214 static int32_t rack_stats_gets_ms_rtt = 1;
215 static int32_t rack_prr_addbackmax = 2;
216 static int32_t rack_do_hystart = 0;
217 static int32_t rack_apply_rtt_with_reduced_conf = 0;
218 static int32_t rack_hibeta_setting = 0;
219 static int32_t rack_default_pacing_divisor = 250;
220 static uint16_t rack_pacing_min_seg = 0;
221 static int32_t rack_timely_off = 0;
222 
223 static int32_t rack_pkt_delay = 1000;
224 static int32_t rack_send_a_lot_in_prr = 1;
225 static int32_t rack_min_to = 1000;	/* Number of microsecond  min timeout */
226 static int32_t rack_verbose_logging = 0;
227 static int32_t rack_ignore_data_after_close = 1;
228 static int32_t rack_enable_shared_cwnd = 1;
229 static int32_t rack_use_cmp_acks = 1;
230 static int32_t rack_use_fsb = 1;
231 static int32_t rack_use_rfo = 1;
232 static int32_t rack_use_rsm_rfo = 1;
233 static int32_t rack_max_abc_post_recovery = 2;
234 static int32_t rack_client_low_buf = 0;
235 static int32_t rack_dsack_std_based = 0x3;	/* bit field bit 1 sets rc_rack_tmr_std_based and bit 2 sets rc_rack_use_dsack */
236 static int32_t rack_bw_multipler = 0;		/* Limit on fill cw's jump up to be this x gp_est */
237 #ifdef TCP_ACCOUNTING
238 static int32_t rack_tcp_accounting = 0;
239 #endif
240 static int32_t rack_limits_scwnd = 1;
241 static int32_t rack_enable_mqueue_for_nonpaced = 0;
242 static int32_t rack_hybrid_allow_set_maxseg = 0;
243 static int32_t rack_disable_prr = 0;
244 static int32_t use_rack_rr = 1;
245 static int32_t rack_non_rxt_use_cr = 0; /* does a non-rxt in recovery use the configured rate (ss/ca)? */
246 static int32_t rack_persist_min = 250000;	/* 250usec */
247 static int32_t rack_persist_max = 2000000;	/* 2 Second in usec's */
248 static int32_t rack_honors_hpts_min_to =  1;	/* Do we honor the hpts minimum time out for pacing timers */
249 static uint32_t rack_max_reduce = 10;		/* Percent we can reduce pacing delay by */
250 static int32_t rack_sack_not_required = 1;	/* set to one to allow non-sack to use rack */
251 static int32_t rack_limit_time_with_srtt = 0;
252 static int32_t rack_autosndbuf_inc = 20;	/* In percentage form */
253 static int32_t rack_enobuf_hw_boost_mult = 0;	/* How many times the hw rate we boost pacing delay using time_between */
254 static int32_t rack_enobuf_hw_max = 12000;	/* 12 ms in usecs */
255 static int32_t rack_enobuf_hw_min = 10000;	/* 10 ms in usecs */
256 static int32_t rack_hw_rwnd_factor = 2;		/* How many max_segs the rwnd must be before we hold off sending */
257 static int32_t rack_hw_check_queue = 0;		/* Do we always pre-check queue depth of a hw queue */
258 
259 /*
260  * Currently regular tcp has a rto_min of 30ms
261  * the backoff goes 12 times so that ends up
262  * being a total of 122.850 seconds before a
263  * connection is killed.
264  */
265 static uint32_t rack_def_data_window = 20;
266 static uint32_t rack_goal_bdp = 2;
267 static uint32_t rack_min_srtts = 1;
268 static uint32_t rack_min_measure_usec = 0;
269 static int32_t rack_tlp_min = 10000;	/* 10ms */
270 static int32_t rack_rto_min = 30000;	/* 30,000 usec same as main freebsd */
271 static int32_t rack_rto_max = 4000000;	/* 4 seconds in usec's */
272 static const int32_t rack_free_cache = 2;
273 static int32_t rack_hptsi_segments = 40;
274 static int32_t rack_rate_sample_method = USE_RTT_LOW;
275 static int32_t rack_pace_every_seg = 0;
276 static int32_t rack_delayed_ack_time = 40000;	/* 40ms in usecs */
277 static int32_t rack_pacing_delay_reduction = 4;
278 static int32_t rack_wma_divisor = 8;		/* For WMA calculation */
279 static int32_t rack_cwnd_block_ends_measure = 0;
280 static int32_t rack_rwnd_block_ends_measure = 0;
281 static int32_t rack_def_profile = 0;
282 
283 static int32_t rack_lower_cwnd_at_tlp = 0;
284 static int32_t rack_always_send_oldest = 0;
285 static int32_t rack_tlp_threshold_use = TLP_USE_TWO_ONE;
286 
287 static uint16_t rack_per_of_gp_ss = 250;	/* 250 % slow-start */
288 static uint16_t rack_per_of_gp_ca = 200;	/* 200 % congestion-avoidance */
289 static uint16_t rack_per_of_gp_rec = 200;	/* 200 % of bw */
290 
291 /* Probertt */
292 static uint16_t rack_per_of_gp_probertt = 60;	/* 60% of bw */
293 static uint16_t rack_per_of_gp_lowthresh = 40;	/* 40% is bottom */
294 static uint16_t rack_per_of_gp_probertt_reduce = 10; /* 10% reduction */
295 static uint16_t rack_atexit_prtt_hbp = 130;	/* Clamp to 130% on exit prtt if highly buffered path */
296 static uint16_t rack_atexit_prtt = 130;	/* Clamp to 100% on exit prtt if non highly buffered path */
297 
298 static uint32_t rack_max_drain_wait = 2;	/* How man gp srtt's before we give up draining */
299 static uint32_t rack_must_drain = 1;		/* How many GP srtt's we *must* wait */
300 static uint32_t rack_probertt_use_min_rtt_entry = 1;	/* Use the min to calculate the goal else gp_srtt */
301 static uint32_t rack_probertt_use_min_rtt_exit = 0;
302 static uint32_t rack_probe_rtt_sets_cwnd = 0;
303 static uint32_t rack_probe_rtt_safety_val = 2000000;	/* No more than 2 sec in probe-rtt */
304 static uint32_t rack_time_between_probertt = 9600000;	/* 9.6 sec in usecs */
305 static uint32_t rack_probertt_gpsrtt_cnt_mul = 0;	/* How many srtt periods does probe-rtt last top fraction */
306 static uint32_t rack_probertt_gpsrtt_cnt_div = 0;	/* How many srtt periods does probe-rtt last bottom fraction */
307 static uint32_t rack_min_probertt_hold = 40000;		/* Equal to delayed ack time */
308 static uint32_t rack_probertt_filter_life = 10000000;
309 static uint32_t rack_probertt_lower_within = 10;
310 static uint32_t rack_min_rtt_movement = 250000;	/* Must move at least 250ms (in microseconds)  to count as a lowering */
311 static int32_t rack_pace_one_seg = 0;		/* Shall we pace for less than 1.4Meg 1MSS at a time */
312 static int32_t rack_probertt_clear_is = 1;
313 static int32_t rack_max_drain_hbp = 1;		/* Extra drain times gpsrtt for highly buffered paths */
314 static int32_t rack_hbp_thresh = 3;		/* what is the divisor max_rtt/min_rtt to decided a hbp */
315 
316 /* Part of pacing */
317 static int32_t rack_max_per_above = 30;		/* When we go to increment stop if above 100+this% */
318 
319 /* Timely information:
320  *
321  * Here we have various control parameters on how
322  * timely may change the multiplier. rack_gain_p5_ub
323  * is associated with timely but not directly influencing
324  * the rate decision like the other variables. It controls
325  * the way fill-cw interacts with timely and caps how much
326  * timely can boost the fill-cw b/w.
327  *
328  * The other values are various boost/shrink numbers as well
329  * as potential caps when adjustments are made to the timely
330  * gain (returned by rack_get_output_gain(). Remember too that
331  * the gain returned can be overriden by other factors such as
332  * probeRTT as well as fixed-rate-pacing.
333  */
334 static int32_t rack_gain_p5_ub = 250;
335 static int32_t rack_gp_per_bw_mul_up = 2;	/* 2% */
336 static int32_t rack_gp_per_bw_mul_down = 4;	/* 4% */
337 static int32_t rack_gp_rtt_maxmul = 3;		/* 3 x maxmin */
338 static int32_t rack_gp_rtt_minmul = 1;		/* minrtt + (minrtt/mindiv) is lower rtt */
339 static int32_t rack_gp_rtt_mindiv = 4;		/* minrtt + (minrtt * minmul/mindiv) is lower rtt */
340 static int32_t rack_gp_decrease_per = 80;	/* Beta value of timely decrease (.8) = 80 */
341 static int32_t rack_gp_increase_per = 2;	/* 2% increase in multiplier */
342 static int32_t rack_per_lower_bound = 50;	/* Don't allow to drop below this multiplier */
343 static int32_t rack_per_upper_bound_ss = 0;	/* Don't allow SS to grow above this */
344 static int32_t rack_per_upper_bound_ca = 0;	/* Don't allow CA to grow above this */
345 static int32_t rack_do_dyn_mul = 0;		/* Are the rack gp multipliers dynamic */
346 static int32_t rack_gp_no_rec_chg = 1;		/* Prohibit recovery from reducing it's multiplier */
347 static int32_t rack_timely_dec_clear = 6;	/* Do we clear decrement count at a value (6)? */
348 static int32_t rack_timely_max_push_rise = 3;	/* One round of pushing */
349 static int32_t rack_timely_max_push_drop = 3;	/* Three round of pushing */
350 static int32_t rack_timely_min_segs = 4;	/* 4 segment minimum */
351 static int32_t rack_timely_no_stopping = 0;
352 static int32_t rack_down_raise_thresh = 100;
353 static int32_t rack_req_segs = 1;
354 static uint64_t rack_bw_rate_cap = 0;
355 static uint64_t rack_fillcw_bw_cap = 3750000;	/* Cap fillcw at 30Mbps */
356 
357 
358 /* Rack specific counters */
359 counter_u64_t rack_saw_enobuf;
360 counter_u64_t rack_saw_enobuf_hw;
361 counter_u64_t rack_saw_enetunreach;
362 counter_u64_t rack_persists_sends;
363 counter_u64_t rack_persists_acks;
364 counter_u64_t rack_persists_loss;
365 counter_u64_t rack_persists_lost_ends;
366 counter_u64_t rack_total_bytes;
367 #ifdef INVARIANTS
368 counter_u64_t rack_adjust_map_bw;
369 #endif
370 /* Tail loss probe counters */
371 counter_u64_t rack_tlp_tot;
372 counter_u64_t rack_tlp_newdata;
373 counter_u64_t rack_tlp_retran;
374 counter_u64_t rack_tlp_retran_bytes;
375 counter_u64_t rack_to_tot;
376 counter_u64_t rack_hot_alloc;
377 counter_u64_t rack_to_alloc;
378 counter_u64_t rack_to_alloc_hard;
379 counter_u64_t rack_to_alloc_emerg;
380 counter_u64_t rack_to_alloc_limited;
381 counter_u64_t rack_alloc_limited_conns;
382 counter_u64_t rack_split_limited;
383 counter_u64_t rack_rxt_clamps_cwnd;
384 counter_u64_t rack_rxt_clamps_cwnd_uniq;
385 
386 counter_u64_t rack_multi_single_eq;
387 counter_u64_t rack_proc_non_comp_ack;
388 
389 counter_u64_t rack_fto_send;
390 counter_u64_t rack_fto_rsm_send;
391 counter_u64_t rack_nfto_resend;
392 counter_u64_t rack_non_fto_send;
393 counter_u64_t rack_extended_rfo;
394 
395 counter_u64_t rack_sack_proc_all;
396 counter_u64_t rack_sack_proc_short;
397 counter_u64_t rack_sack_proc_restart;
398 
399 counter_u64_t rack_input_idle_reduces;
400 counter_u64_t rack_collapsed_win;
401 counter_u64_t rack_collapsed_win_seen;
402 counter_u64_t rack_collapsed_win_rxt;
403 counter_u64_t rack_collapsed_win_rxt_bytes;
404 counter_u64_t rack_try_scwnd;
405 counter_u64_t rack_hw_pace_init_fail;
406 counter_u64_t rack_hw_pace_lost;
407 
408 counter_u64_t rack_out_size[TCP_MSS_ACCT_SIZE];
409 counter_u64_t rack_opts_arry[RACK_OPTS_SIZE];
410 
411 
412 #define	RACK_REXMTVAL(tp) max(rack_rto_min, ((tp)->t_srtt + ((tp)->t_rttvar << 2)))
413 
414 #define	RACK_TCPT_RANGESET(tv, value, tvmin, tvmax, slop) do {	\
415 	(tv) = (value) + slop;	 \
416 	if ((u_long)(tv) < (u_long)(tvmin)) \
417 		(tv) = (tvmin); \
418 	if ((u_long)(tv) > (u_long)(tvmax)) \
419 		(tv) = (tvmax); \
420 } while (0)
421 
422 static void
423 rack_log_progress_event(struct tcp_rack *rack, struct tcpcb *tp, uint32_t tick,  int event, int line);
424 
425 static int
426 rack_process_ack(struct mbuf *m, struct tcphdr *th,
427     struct socket *so, struct tcpcb *tp, struct tcpopt *to,
428     uint32_t tiwin, int32_t tlen, int32_t * ofia, int32_t thflags, int32_t * ret_val, int32_t orig_tlen);
429 static int
430 rack_process_data(struct mbuf *m, struct tcphdr *th,
431     struct socket *so, struct tcpcb *tp, int32_t drop_hdrlen, int32_t tlen,
432     uint32_t tiwin, int32_t thflags, int32_t nxt_pkt);
433 static void
434 rack_ack_received(struct tcpcb *tp, struct tcp_rack *rack,
435    uint32_t th_ack, uint16_t nsegs, uint16_t type, int32_t recovery);
436 static struct rack_sendmap *rack_alloc(struct tcp_rack *rack);
437 static struct rack_sendmap *rack_alloc_limit(struct tcp_rack *rack,
438     uint8_t limit_type);
439 static struct rack_sendmap *
440 rack_check_recovery_mode(struct tcpcb *tp,
441     uint32_t tsused);
442 static uint32_t
443 rack_grab_rtt(struct tcpcb *tp, struct tcp_rack *rack);
444 static void
445 rack_cong_signal(struct tcpcb *tp,
446 		 uint32_t type, uint32_t ack, int );
447 static void rack_counter_destroy(void);
448 static int
449 rack_ctloutput(struct tcpcb *tp, struct sockopt *sopt);
450 static int32_t rack_ctor(void *mem, int32_t size, void *arg, int32_t how);
451 static void
452 rack_set_pace_segments(struct tcpcb *tp, struct tcp_rack *rack, uint32_t line, uint64_t *fill_override);
453 static void
454 rack_do_segment(struct tcpcb *tp, struct mbuf *m, struct tcphdr *th,
455     int32_t drop_hdrlen, int32_t tlen, uint8_t iptos);
456 static void rack_dtor(void *mem, int32_t size, void *arg);
457 static void
458 rack_log_alt_to_to_cancel(struct tcp_rack *rack,
459     uint32_t flex1, uint32_t flex2,
460     uint32_t flex3, uint32_t flex4,
461     uint32_t flex5, uint32_t flex6,
462     uint16_t flex7, uint8_t mod);
463 
464 static void
465 rack_log_pacing_delay_calc(struct tcp_rack *rack, uint32_t len, uint32_t pacing_delay,
466    uint64_t bw_est, uint64_t bw, uint64_t len_time, int method, int line,
467    struct rack_sendmap *rsm, uint8_t quality);
468 static struct rack_sendmap *
469 rack_find_high_nonack(struct tcp_rack *rack,
470     struct rack_sendmap *rsm);
471 static struct rack_sendmap *rack_find_lowest_rsm(struct tcp_rack *rack);
472 static void rack_free(struct tcp_rack *rack, struct rack_sendmap *rsm);
473 static void rack_fini(struct tcpcb *tp, int32_t tcb_is_purged);
474 static int rack_get_sockopt(struct tcpcb *tp, struct sockopt *sopt);
475 static void
476 rack_do_goodput_measurement(struct tcpcb *tp, struct tcp_rack *rack,
477 			    tcp_seq th_ack, int line, uint8_t quality);
478 static void
479 rack_log_type_pacing_sizes(struct tcpcb *tp, struct tcp_rack *rack, uint32_t arg1, uint32_t arg2, uint32_t arg3, uint8_t frm);
480 
481 static uint32_t
482 rack_get_pacing_len(struct tcp_rack *rack, uint64_t bw, uint32_t mss);
483 static int32_t rack_handoff_ok(struct tcpcb *tp);
484 static int32_t rack_init(struct tcpcb *tp, void **ptr);
485 static void rack_init_sysctls(void);
486 
487 static void
488 rack_log_ack(struct tcpcb *tp, struct tcpopt *to,
489     struct tcphdr *th, int entered_rec, int dup_ack_struck,
490     int *dsack_seen, int *sacks_seen);
491 static void
492 rack_log_output(struct tcpcb *tp, struct tcpopt *to, int32_t len,
493     uint32_t seq_out, uint16_t th_flags, int32_t err, uint64_t ts,
494     struct rack_sendmap *hintrsm, uint32_t add_flags, struct mbuf *s_mb, uint32_t s_moff, int hw_tls, int segsiz);
495 
496 static uint64_t rack_get_gp_est(struct tcp_rack *rack);
497 
498 
499 static void
500 rack_log_sack_passed(struct tcpcb *tp, struct tcp_rack *rack,
501     struct rack_sendmap *rsm, uint32_t cts, int line);
502 static void rack_log_to_event(struct tcp_rack *rack, int32_t to_num, struct rack_sendmap *rsm);
503 static int32_t rack_output(struct tcpcb *tp);
504 
505 static uint32_t
506 rack_proc_sack_blk(struct tcpcb *tp, struct tcp_rack *rack,
507     struct sackblk *sack, struct tcpopt *to, struct rack_sendmap **prsm,
508     uint32_t cts, uint32_t segsiz);
509 static void rack_post_recovery(struct tcpcb *tp, uint32_t th_seq);
510 static void rack_remxt_tmr(struct tcpcb *tp);
511 static int rack_set_sockopt(struct tcpcb *tp, struct sockopt *sopt);
512 static void rack_set_state(struct tcpcb *tp, struct tcp_rack *rack);
513 static int32_t rack_stopall(struct tcpcb *tp);
514 static void rack_timer_cancel(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cts, int line);
515 static uint32_t
516 rack_update_entry(struct tcpcb *tp, struct tcp_rack *rack,
517     struct rack_sendmap *rsm, uint64_t ts, int32_t * lenp, uint32_t add_flag, int segsiz);
518 static void
519 rack_update_rsm(struct tcpcb *tp, struct tcp_rack *rack,
520     struct rack_sendmap *rsm, uint64_t ts, uint32_t add_flag, int segsiz);
521 static int
522 rack_update_rtt(struct tcpcb *tp, struct tcp_rack *rack,
523     struct rack_sendmap *rsm, struct tcpopt *to, uint32_t cts, int32_t ack_type, tcp_seq th_ack);
524 static int32_t tcp_addrack(module_t mod, int32_t type, void *data);
525 static int
526 rack_do_close_wait(struct mbuf *m, struct tcphdr *th,
527     struct socket *so, struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen,
528     int32_t tlen, uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos);
529 
530 static int
531 rack_do_closing(struct mbuf *m, struct tcphdr *th,
532     struct socket *so, struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen,
533     int32_t tlen, uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos);
534 static int
535 rack_do_established(struct mbuf *m, struct tcphdr *th,
536     struct socket *so, struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen,
537     int32_t tlen, uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos);
538 static int
539 rack_do_fastnewdata(struct mbuf *m, struct tcphdr *th,
540     struct socket *so, struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen,
541     int32_t tlen, uint32_t tiwin, int32_t nxt_pkt, uint8_t iptos);
542 static int
543 rack_do_fin_wait_1(struct mbuf *m, struct tcphdr *th,
544     struct socket *so, struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen,
545     int32_t tlen, uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos);
546 static int
547 rack_do_fin_wait_2(struct mbuf *m, struct tcphdr *th,
548     struct socket *so, struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen,
549     int32_t tlen, uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos);
550 static int
551 rack_do_lastack(struct mbuf *m, struct tcphdr *th,
552     struct socket *so, struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen,
553     int32_t tlen, uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos);
554 static int
555 rack_do_syn_recv(struct mbuf *m, struct tcphdr *th,
556     struct socket *so, struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen,
557     int32_t tlen, uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos);
558 static int
559 rack_do_syn_sent(struct mbuf *m, struct tcphdr *th,
560     struct socket *so, struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen,
561     int32_t tlen, uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos);
562 static void rack_chk_req_and_hybrid_on_out(struct tcp_rack *rack, tcp_seq seq, uint32_t len, uint64_t cts);
563 struct rack_sendmap *
564 tcp_rack_output(struct tcpcb *tp, struct tcp_rack *rack,
565     uint32_t tsused);
566 static void tcp_rack_xmit_timer(struct tcp_rack *rack, int32_t rtt,
567     uint32_t len, uint32_t us_tim, int confidence, struct rack_sendmap *rsm, uint16_t rtrcnt);
568 static void
569      tcp_rack_partialack(struct tcpcb *tp);
570 static int
571 rack_set_profile(struct tcp_rack *rack, int prof);
572 static void
573 rack_apply_deferred_options(struct tcp_rack *rack);
574 
575 int32_t rack_clear_counter=0;
576 
577 static uint64_t
578 rack_get_lt_bw(struct tcp_rack *rack)
579 {
580 	struct timeval tv;
581 	uint64_t tim, bytes;
582 
583 	tim = rack->r_ctl.lt_bw_time;
584 	bytes = rack->r_ctl.lt_bw_bytes;
585 	if (rack->lt_bw_up) {
586 		/* Include all the current bytes too */
587 		microuptime(&tv);
588 		bytes += (rack->rc_tp->snd_una - rack->r_ctl.lt_seq);
589 		tim += (tcp_tv_to_lusec(&tv) - rack->r_ctl.lt_timemark);
590 	}
591 	if ((bytes != 0) && (tim != 0))
592 		return ((bytes * (uint64_t)1000000) / tim);
593 	else
594 		return (0);
595 }
596 
597 static void
598 rack_swap_beta_values(struct tcp_rack *rack, uint8_t flex8)
599 {
600 	struct sockopt sopt;
601 	struct cc_newreno_opts opt;
602 	struct tcpcb *tp;
603 	uint32_t old_beta;
604 	uint32_t old_beta_ecn;
605 	int error = 0, failed = 0;
606 
607 	tp = rack->rc_tp;
608 	if (tp->t_cc == NULL) {
609 		/* Tcb is leaving */
610 		return;
611 	}
612 	rack->rc_pacing_cc_set = 1;
613 	if (strcmp(tp->t_cc->name, CCALGONAME_NEWRENO) != 0) {
614 		/* Not new-reno we can't play games with beta! */
615 		failed = 1;
616 		goto out;
617 
618 	}
619 	if (CC_ALGO(tp)->ctl_output == NULL)  {
620 		/* Huh, not using new-reno so no swaps.? */
621 		failed = 2;
622 		goto out;
623 	}
624 	/* Get the current values out */
625 	sopt.sopt_valsize = sizeof(struct cc_newreno_opts);
626 	sopt.sopt_dir = SOPT_GET;
627 	opt.name = CC_NEWRENO_BETA;
628 	error = CC_ALGO(tp)->ctl_output(&tp->t_ccv, &sopt, &opt);
629 	if (error)  {
630 		failed = 3;
631 		goto out;
632 	}
633 	old_beta = opt.val;
634 	opt.name = CC_NEWRENO_BETA_ECN;
635 	error = CC_ALGO(tp)->ctl_output(&tp->t_ccv, &sopt, &opt);
636 	if (error)  {
637 		failed = 4;
638 		goto out;
639 	}
640 	old_beta_ecn = opt.val;
641 
642 	/* Now lets set in the values we have stored */
643 	sopt.sopt_dir = SOPT_SET;
644 	opt.name = CC_NEWRENO_BETA;
645 	opt.val = rack->r_ctl.rc_saved_beta;
646 	error = CC_ALGO(tp)->ctl_output(&tp->t_ccv, &sopt, &opt);
647 	if (error)  {
648 		failed = 5;
649 		goto out;
650 	}
651 	opt.name = CC_NEWRENO_BETA_ECN;
652 	opt.val = rack->r_ctl.rc_saved_beta_ecn;
653 	error = CC_ALGO(tp)->ctl_output(&tp->t_ccv, &sopt, &opt);
654 	if (error) {
655 		failed = 6;
656 		goto out;
657 	}
658 	/* Save off the values for restoral */
659 	rack->r_ctl.rc_saved_beta = old_beta;
660 	rack->r_ctl.rc_saved_beta_ecn = old_beta_ecn;
661 out:
662 	if (rack_verbose_logging && tcp_bblogging_on(rack->rc_tp)) {
663 		union tcp_log_stackspecific log;
664 		struct timeval tv;
665 		struct newreno *ptr;
666 
667 		ptr = ((struct newreno *)tp->t_ccv.cc_data);
668 		memset(&log, 0, sizeof(log));
669 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
670 		log.u_bbr.flex1 = ptr->beta;
671 		log.u_bbr.flex2 = ptr->beta_ecn;
672 		log.u_bbr.flex3 = ptr->newreno_flags;
673 		log.u_bbr.flex4 = rack->r_ctl.rc_saved_beta;
674 		log.u_bbr.flex5 = rack->r_ctl.rc_saved_beta_ecn;
675 		log.u_bbr.flex6 = failed;
676 		log.u_bbr.flex7 = rack->gp_ready;
677 		log.u_bbr.flex7 <<= 1;
678 		log.u_bbr.flex7 |= rack->use_fixed_rate;
679 		log.u_bbr.flex7 <<= 1;
680 		log.u_bbr.flex7 |= rack->rc_pacing_cc_set;
681 		log.u_bbr.pkts_out = rack->r_ctl.rc_prr_sndcnt;
682 		log.u_bbr.flex8 = flex8;
683 		tcp_log_event(tp, NULL, NULL, NULL, BBR_LOG_CWND, error,
684 			       0, &log, false, NULL, NULL, 0, &tv);
685 	}
686 }
687 
688 static void
689 rack_set_cc_pacing(struct tcp_rack *rack)
690 {
691 	if (rack->rc_pacing_cc_set)
692 		return;
693 	/*
694 	 * Use the swap utility placing in 3 for flex8 to id a
695 	 * set of a new set of values.
696 	 */
697 	rack->rc_pacing_cc_set = 1;
698 	rack_swap_beta_values(rack, 3);
699 }
700 
701 static void
702 rack_undo_cc_pacing(struct tcp_rack *rack)
703 {
704 	if (rack->rc_pacing_cc_set == 0)
705 		return;
706 	/*
707 	 * Use the swap utility placing in 4 for flex8 to id a
708 	 * restoral of the old values.
709 	 */
710 	rack->rc_pacing_cc_set = 0;
711 	rack_swap_beta_values(rack, 4);
712 }
713 
714 static void
715 rack_remove_pacing(struct tcp_rack *rack)
716 {
717 	if (rack->rc_pacing_cc_set)
718 		rack_undo_cc_pacing(rack);
719 	if (rack->r_ctl.pacing_method & RACK_REG_PACING)
720 		tcp_decrement_paced_conn();
721 	if (rack->r_ctl.pacing_method & RACK_DGP_PACING)
722 		tcp_dec_dgp_pacing_cnt();
723 	rack->rc_always_pace = 0;
724 	rack->r_ctl.pacing_method = RACK_PACING_NONE;
725 	rack->dgp_on = 0;
726 	rack->rc_hybrid_mode = 0;
727 	rack->use_fixed_rate = 0;
728 }
729 
730 static void
731 rack_log_gpset(struct tcp_rack *rack, uint32_t seq_end, uint32_t ack_end_t,
732 	       uint32_t send_end_t, int line, uint8_t mode, struct rack_sendmap *rsm)
733 {
734 	if (tcp_bblogging_on(rack->rc_tp) && (rack_verbose_logging != 0)) {
735 		union tcp_log_stackspecific log;
736 		struct timeval tv;
737 
738 		memset(&log, 0, sizeof(log));
739 		log.u_bbr.flex1 = seq_end;
740 		log.u_bbr.flex2 = rack->rc_tp->gput_seq;
741 		log.u_bbr.flex3 = ack_end_t;
742 		log.u_bbr.flex4 = rack->rc_tp->gput_ts;
743 		log.u_bbr.flex5 = send_end_t;
744 		log.u_bbr.flex6 = rack->rc_tp->gput_ack;
745 		log.u_bbr.flex7 = mode;
746 		log.u_bbr.flex8 = 69;
747 		log.u_bbr.rttProp = rack->r_ctl.rc_gp_cumack_ts;
748 		log.u_bbr.delRate = rack->r_ctl.rc_gp_output_ts;
749 		log.u_bbr.pkts_out = line;
750 		log.u_bbr.cwnd_gain = rack->app_limited_needs_set;
751 		log.u_bbr.pkt_epoch = rack->r_ctl.rc_app_limited_cnt;
752 		log.u_bbr.epoch = rack->r_ctl.current_round;
753 		log.u_bbr.lt_epoch = rack->r_ctl.rc_considered_lost;
754 		if (rsm != NULL) {
755 			log.u_bbr.applimited = rsm->r_start;
756 			log.u_bbr.delivered = rsm->r_end;
757 			log.u_bbr.epoch = rsm->r_flags;
758 		}
759 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
760 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
761 		    &rack->rc_inp->inp_socket->so_rcv,
762 		    &rack->rc_inp->inp_socket->so_snd,
763 		    BBR_LOG_HPTSI_CALC, 0,
764 		    0, &log, false, &tv);
765 	}
766 }
767 
768 static int
769 sysctl_rack_clear(SYSCTL_HANDLER_ARGS)
770 {
771 	uint32_t stat;
772 	int32_t error;
773 
774 	error = SYSCTL_OUT(req, &rack_clear_counter, sizeof(uint32_t));
775 	if (error || req->newptr == NULL)
776 		return error;
777 
778 	error = SYSCTL_IN(req, &stat, sizeof(uint32_t));
779 	if (error)
780 		return (error);
781 	if (stat == 1) {
782 #ifdef INVARIANTS
783 		printf("Clearing RACK counters\n");
784 #endif
785 		counter_u64_zero(rack_tlp_tot);
786 		counter_u64_zero(rack_tlp_newdata);
787 		counter_u64_zero(rack_tlp_retran);
788 		counter_u64_zero(rack_tlp_retran_bytes);
789 		counter_u64_zero(rack_to_tot);
790 		counter_u64_zero(rack_saw_enobuf);
791 		counter_u64_zero(rack_saw_enobuf_hw);
792 		counter_u64_zero(rack_saw_enetunreach);
793 		counter_u64_zero(rack_persists_sends);
794 		counter_u64_zero(rack_total_bytes);
795 		counter_u64_zero(rack_persists_acks);
796 		counter_u64_zero(rack_persists_loss);
797 		counter_u64_zero(rack_persists_lost_ends);
798 #ifdef INVARIANTS
799 		counter_u64_zero(rack_adjust_map_bw);
800 #endif
801 		counter_u64_zero(rack_to_alloc_hard);
802 		counter_u64_zero(rack_to_alloc_emerg);
803 		counter_u64_zero(rack_sack_proc_all);
804 		counter_u64_zero(rack_fto_send);
805 		counter_u64_zero(rack_fto_rsm_send);
806 		counter_u64_zero(rack_extended_rfo);
807 		counter_u64_zero(rack_hw_pace_init_fail);
808 		counter_u64_zero(rack_hw_pace_lost);
809 		counter_u64_zero(rack_non_fto_send);
810 		counter_u64_zero(rack_nfto_resend);
811 		counter_u64_zero(rack_sack_proc_short);
812 		counter_u64_zero(rack_sack_proc_restart);
813 		counter_u64_zero(rack_to_alloc);
814 		counter_u64_zero(rack_to_alloc_limited);
815 		counter_u64_zero(rack_alloc_limited_conns);
816 		counter_u64_zero(rack_split_limited);
817 		counter_u64_zero(rack_rxt_clamps_cwnd);
818 		counter_u64_zero(rack_rxt_clamps_cwnd_uniq);
819 		counter_u64_zero(rack_multi_single_eq);
820 		counter_u64_zero(rack_proc_non_comp_ack);
821 		counter_u64_zero(rack_try_scwnd);
822 		counter_u64_zero(rack_collapsed_win);
823 		counter_u64_zero(rack_collapsed_win_rxt);
824 		counter_u64_zero(rack_collapsed_win_seen);
825 		counter_u64_zero(rack_collapsed_win_rxt_bytes);
826 	} else if (stat == 2) {
827 #ifdef INVARIANTS
828 		printf("Clearing RACK option array\n");
829 #endif
830 		COUNTER_ARRAY_ZERO(rack_opts_arry, RACK_OPTS_SIZE);
831 	} else if (stat == 3) {
832 		printf("Rack has no stats counters to clear (use 1 to clear all stats in sysctl node)\n");
833 	} else if (stat == 4) {
834 #ifdef INVARIANTS
835 		printf("Clearing RACK out size array\n");
836 #endif
837 		COUNTER_ARRAY_ZERO(rack_out_size, TCP_MSS_ACCT_SIZE);
838 	}
839 	rack_clear_counter = 0;
840 	return (0);
841 }
842 
843 static void
844 rack_init_sysctls(void)
845 {
846 	struct sysctl_oid *rack_counters;
847 	struct sysctl_oid *rack_pacing;
848 	struct sysctl_oid *rack_timely;
849 	struct sysctl_oid *rack_timers;
850 	struct sysctl_oid *rack_tlp;
851 	struct sysctl_oid *rack_misc;
852 	struct sysctl_oid *rack_features;
853 	struct sysctl_oid *rack_measure;
854 	struct sysctl_oid *rack_probertt;
855 	struct sysctl_oid *rack_hw_pacing;
856 
857 	rack_counters = SYSCTL_ADD_NODE(&rack_sysctl_ctx,
858 	    SYSCTL_CHILDREN(rack_sysctl_root),
859 	    OID_AUTO,
860 	    "stats",
861 	    CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
862 	    "Rack Counters");
863 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
864 	    SYSCTL_CHILDREN(rack_sysctl_root),
865 	    OID_AUTO, "rate_sample_method", CTLFLAG_RW,
866 	    &rack_rate_sample_method , USE_RTT_LOW,
867 	    "What method should we use for rate sampling 0=high, 1=low ");
868 	/* Probe rtt related controls */
869 	rack_probertt = SYSCTL_ADD_NODE(&rack_sysctl_ctx,
870 	    SYSCTL_CHILDREN(rack_sysctl_root),
871 	    OID_AUTO,
872 	    "probertt",
873 	    CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
874 	    "ProbeRTT related Controls");
875 	SYSCTL_ADD_U16(&rack_sysctl_ctx,
876 	    SYSCTL_CHILDREN(rack_probertt),
877 	    OID_AUTO, "exit_per_hpb", CTLFLAG_RW,
878 	    &rack_atexit_prtt_hbp, 130,
879 	    "What percentage above goodput do we clamp CA/SS to at exit on high-BDP path 110%");
880 	SYSCTL_ADD_U16(&rack_sysctl_ctx,
881 	    SYSCTL_CHILDREN(rack_probertt),
882 	    OID_AUTO, "exit_per_nonhpb", CTLFLAG_RW,
883 	    &rack_atexit_prtt, 130,
884 	    "What percentage above goodput do we clamp CA/SS to at exit on a non high-BDP path 100%");
885 	SYSCTL_ADD_U16(&rack_sysctl_ctx,
886 	    SYSCTL_CHILDREN(rack_probertt),
887 	    OID_AUTO, "gp_per_mul", CTLFLAG_RW,
888 	    &rack_per_of_gp_probertt, 60,
889 	    "What percentage of goodput do we pace at in probertt");
890 	SYSCTL_ADD_U16(&rack_sysctl_ctx,
891 	    SYSCTL_CHILDREN(rack_probertt),
892 	    OID_AUTO, "gp_per_reduce", CTLFLAG_RW,
893 	    &rack_per_of_gp_probertt_reduce, 10,
894 	    "What percentage of goodput do we reduce every gp_srtt");
895 	SYSCTL_ADD_U16(&rack_sysctl_ctx,
896 	    SYSCTL_CHILDREN(rack_probertt),
897 	    OID_AUTO, "gp_per_low", CTLFLAG_RW,
898 	    &rack_per_of_gp_lowthresh, 40,
899 	    "What percentage of goodput do we allow the multiplier to fall to");
900 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
901 	    SYSCTL_CHILDREN(rack_probertt),
902 	    OID_AUTO, "time_between", CTLFLAG_RW,
903 	    &rack_time_between_probertt, 96000000,
904 	    "How many useconds between the lowest rtt falling must past before we enter probertt");
905 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
906 	    SYSCTL_CHILDREN(rack_probertt),
907 	    OID_AUTO, "safety", CTLFLAG_RW,
908 	    &rack_probe_rtt_safety_val, 2000000,
909 	    "If not zero, provides a maximum usecond that you can stay in probertt (2sec = 2000000)");
910 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
911 	    SYSCTL_CHILDREN(rack_probertt),
912 	    OID_AUTO, "sets_cwnd", CTLFLAG_RW,
913 	    &rack_probe_rtt_sets_cwnd, 0,
914 	    "Do we set the cwnd too (if always_lower is on)");
915 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
916 	    SYSCTL_CHILDREN(rack_probertt),
917 	    OID_AUTO, "maxdrainsrtts", CTLFLAG_RW,
918 	    &rack_max_drain_wait, 2,
919 	    "Maximum number of gp_srtt's to hold in drain waiting for flight to reach goal");
920 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
921 	    SYSCTL_CHILDREN(rack_probertt),
922 	    OID_AUTO, "mustdrainsrtts", CTLFLAG_RW,
923 	    &rack_must_drain, 1,
924 	    "We must drain this many gp_srtt's waiting for flight to reach goal");
925 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
926 	    SYSCTL_CHILDREN(rack_probertt),
927 	    OID_AUTO, "goal_use_min_entry", CTLFLAG_RW,
928 	    &rack_probertt_use_min_rtt_entry, 1,
929 	    "Should we use the min-rtt to calculate the goal rtt (else gp_srtt) at entry");
930 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
931 	    SYSCTL_CHILDREN(rack_probertt),
932 	    OID_AUTO, "goal_use_min_exit", CTLFLAG_RW,
933 	    &rack_probertt_use_min_rtt_exit, 0,
934 	    "How to set cwnd at exit, 0 - dynamic, 1 - use min-rtt, 2 - use curgprtt, 3 - entry gp-rtt");
935 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
936 	    SYSCTL_CHILDREN(rack_probertt),
937 	    OID_AUTO, "length_div", CTLFLAG_RW,
938 	    &rack_probertt_gpsrtt_cnt_div, 0,
939 	    "How many recent goodput srtt periods plus hold tim does probertt last (bottom of fraction)");
940 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
941 	    SYSCTL_CHILDREN(rack_probertt),
942 	    OID_AUTO, "length_mul", CTLFLAG_RW,
943 	    &rack_probertt_gpsrtt_cnt_mul, 0,
944 	    "How many recent goodput srtt periods plus hold tim does probertt last (top of fraction)");
945 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
946 	    SYSCTL_CHILDREN(rack_probertt),
947 	    OID_AUTO, "holdtim_at_target", CTLFLAG_RW,
948 	    &rack_min_probertt_hold, 200000,
949 	    "What is the minimum time we hold probertt at target");
950 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
951 	    SYSCTL_CHILDREN(rack_probertt),
952 	    OID_AUTO, "filter_life", CTLFLAG_RW,
953 	    &rack_probertt_filter_life, 10000000,
954 	    "What is the time for the filters life in useconds");
955 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
956 	    SYSCTL_CHILDREN(rack_probertt),
957 	    OID_AUTO, "lower_within", CTLFLAG_RW,
958 	    &rack_probertt_lower_within, 10,
959 	    "If the rtt goes lower within this percentage of the time, go into probe-rtt");
960 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
961 	    SYSCTL_CHILDREN(rack_probertt),
962 	    OID_AUTO, "must_move", CTLFLAG_RW,
963 	    &rack_min_rtt_movement, 250,
964 	    "How much is the minimum movement in rtt to count as a drop for probertt purposes");
965 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
966 	    SYSCTL_CHILDREN(rack_probertt),
967 	    OID_AUTO, "clear_is_cnts", CTLFLAG_RW,
968 	    &rack_probertt_clear_is, 1,
969 	    "Do we clear I/S counts on exiting probe-rtt");
970 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
971 	    SYSCTL_CHILDREN(rack_probertt),
972 	    OID_AUTO, "hbp_extra_drain", CTLFLAG_RW,
973 	    &rack_max_drain_hbp, 1,
974 	    "How many extra drain gpsrtt's do we get in highly buffered paths");
975 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
976 	    SYSCTL_CHILDREN(rack_probertt),
977 	    OID_AUTO, "hbp_threshold", CTLFLAG_RW,
978 	    &rack_hbp_thresh, 3,
979 	    "We are highly buffered if min_rtt_seen / max_rtt_seen > this-threshold");
980 	/* Pacing related sysctls */
981 	rack_pacing = SYSCTL_ADD_NODE(&rack_sysctl_ctx,
982 	    SYSCTL_CHILDREN(rack_sysctl_root),
983 	    OID_AUTO,
984 	    "pacing",
985 	    CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
986 	    "Pacing related Controls");
987 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
988 	    SYSCTL_CHILDREN(rack_pacing),
989 	    OID_AUTO, "pcm_enabled", CTLFLAG_RW,
990 	    &rack_pcm_is_enabled, 1,
991 	    "Do we by default do PCM measurements?");
992 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
993 	    SYSCTL_CHILDREN(rack_pacing),
994 	    OID_AUTO, "pcm_rnds", CTLFLAG_RW,
995 	    &rack_pcm_every_n_rounds, 100,
996 	    "How many rounds before we need to do a PCM measurement");
997 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
998 	    SYSCTL_CHILDREN(rack_pacing),
999 	    OID_AUTO, "pcm_blast", CTLFLAG_RW,
1000 	    &rack_pcm_blast, 0,
1001 	    "Blast out the full cwnd/rwnd when doing a PCM measurement");
1002 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
1003 	    SYSCTL_CHILDREN(rack_pacing),
1004 	    OID_AUTO, "rnd_gp_gain", CTLFLAG_RW,
1005 	    &rack_gp_gain_req, 1200,
1006 	    "How much do we have to increase the GP to record the round 1200 = 120.0");
1007 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
1008 	    SYSCTL_CHILDREN(rack_pacing),
1009 	    OID_AUTO, "dgp_out_of_ss_at", CTLFLAG_RW,
1010 	    &rack_rnd_cnt_req, 0x10005,
1011 	    "How many rounds less than rnd_gp_gain will drop us out of SS");
1012 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1013 	    SYSCTL_CHILDREN(rack_pacing),
1014 	    OID_AUTO, "no_timely", CTLFLAG_RW,
1015 	    &rack_timely_off, 0,
1016 	    "Do we not use timely in DGP?");
1017 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1018 	    SYSCTL_CHILDREN(rack_pacing),
1019 	    OID_AUTO, "fillcw", CTLFLAG_RW,
1020 	    &rack_fill_cw_state, 0,
1021 	    "Enable fillcw on new connections (default=0 off)?");
1022 	SYSCTL_ADD_U16(&rack_sysctl_ctx,
1023 	    SYSCTL_CHILDREN(rack_pacing),
1024 	    OID_AUTO, "min_burst", CTLFLAG_RW,
1025 	    &rack_pacing_min_seg, 0,
1026 	    "What is the min burst size for pacing (0 disables)?");
1027 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1028 	    SYSCTL_CHILDREN(rack_pacing),
1029 	    OID_AUTO, "divisor", CTLFLAG_RW,
1030 	    &rack_default_pacing_divisor, 250,
1031 	    "What is the default divisor given to the rl code?");
1032 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1033 	    SYSCTL_CHILDREN(rack_pacing),
1034 	    OID_AUTO, "fillcw_max_mult", CTLFLAG_RW,
1035 	    &rack_bw_multipler, 0,
1036 	    "What is the limit multiplier of the current gp_est that fillcw can increase the b/w too, 200 == 200% (0 = off)?");
1037 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1038 	    SYSCTL_CHILDREN(rack_pacing),
1039 	    OID_AUTO, "max_pace_over", CTLFLAG_RW,
1040 	    &rack_max_per_above, 30,
1041 	    "What is the maximum allowable percentage that we can pace above (so 30 = 130% of our goal)");
1042 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1043 	    SYSCTL_CHILDREN(rack_pacing),
1044 	    OID_AUTO, "allow1mss", CTLFLAG_RW,
1045 	    &rack_pace_one_seg, 0,
1046 	    "Do we allow low b/w pacing of 1MSS instead of two (1.2Meg and less)?");
1047 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1048 	    SYSCTL_CHILDREN(rack_pacing),
1049 	    OID_AUTO, "limit_wsrtt", CTLFLAG_RW,
1050 	    &rack_limit_time_with_srtt, 0,
1051 	    "Do we limit pacing time based on srtt");
1052 	SYSCTL_ADD_U16(&rack_sysctl_ctx,
1053 	    SYSCTL_CHILDREN(rack_pacing),
1054 	    OID_AUTO, "gp_per_ss", CTLFLAG_RW,
1055 	    &rack_per_of_gp_ss, 250,
1056 	    "If non zero, what percentage of goodput to pace at in slow start");
1057 	SYSCTL_ADD_U16(&rack_sysctl_ctx,
1058 	    SYSCTL_CHILDREN(rack_pacing),
1059 	    OID_AUTO, "gp_per_ca", CTLFLAG_RW,
1060 	    &rack_per_of_gp_ca, 150,
1061 	    "If non zero, what percentage of goodput to pace at in congestion avoidance");
1062 	SYSCTL_ADD_U16(&rack_sysctl_ctx,
1063 	    SYSCTL_CHILDREN(rack_pacing),
1064 	    OID_AUTO, "gp_per_rec", CTLFLAG_RW,
1065 	    &rack_per_of_gp_rec, 200,
1066 	    "If non zero, what percentage of goodput to pace at in recovery");
1067 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1068 	    SYSCTL_CHILDREN(rack_pacing),
1069 	    OID_AUTO, "pace_max_seg", CTLFLAG_RW,
1070 	    &rack_hptsi_segments, 40,
1071 	    "What size is the max for TSO segments in pacing and burst mitigation");
1072 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1073 	    SYSCTL_CHILDREN(rack_pacing),
1074 	    OID_AUTO, "burst_reduces", CTLFLAG_RW,
1075 	    &rack_pacing_delay_reduction, 4,
1076 	    "When doing only burst mitigation what is the reduce divisor");
1077 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1078 	    SYSCTL_CHILDREN(rack_sysctl_root),
1079 	    OID_AUTO, "use_pacing", CTLFLAG_RW,
1080 	    &rack_pace_every_seg, 0,
1081 	    "If set we use pacing, if clear we use only the original burst mitigation");
1082 	SYSCTL_ADD_U64(&rack_sysctl_ctx,
1083 	    SYSCTL_CHILDREN(rack_pacing),
1084 	    OID_AUTO, "rate_cap", CTLFLAG_RW,
1085 	    &rack_bw_rate_cap, 0,
1086 	    "If set we apply this value to the absolute rate cap used by pacing");
1087 	SYSCTL_ADD_U64(&rack_sysctl_ctx,
1088 	    SYSCTL_CHILDREN(rack_pacing),
1089 	    OID_AUTO, "fillcw_cap", CTLFLAG_RW,
1090 	    &rack_fillcw_bw_cap, 3750000,
1091 	    "Do we have an absolute cap on the amount of b/w fillcw can specify (0 = no)?");
1092 	SYSCTL_ADD_U8(&rack_sysctl_ctx,
1093 	    SYSCTL_CHILDREN(rack_sysctl_root),
1094 	    OID_AUTO, "req_measure_cnt", CTLFLAG_RW,
1095 	    &rack_req_measurements, 1,
1096 	    "If doing dynamic pacing, how many measurements must be in before we start pacing?");
1097 	/* Hardware pacing */
1098 	rack_hw_pacing = SYSCTL_ADD_NODE(&rack_sysctl_ctx,
1099 	    SYSCTL_CHILDREN(rack_sysctl_root),
1100 	    OID_AUTO,
1101 	    "hdwr_pacing",
1102 	    CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
1103 	    "Pacing related Controls");
1104 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1105 	    SYSCTL_CHILDREN(rack_hw_pacing),
1106 	    OID_AUTO, "rwnd_factor", CTLFLAG_RW,
1107 	    &rack_hw_rwnd_factor, 2,
1108 	    "How many times does snd_wnd need to be bigger than pace_max_seg so we will hold off and get more acks?");
1109 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1110 	    SYSCTL_CHILDREN(rack_hw_pacing),
1111 	    OID_AUTO, "precheck", CTLFLAG_RW,
1112 	    &rack_hw_check_queue, 0,
1113 	    "Do we always precheck the hdwr pacing queue to avoid ENOBUF's?");
1114 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1115 	    SYSCTL_CHILDREN(rack_hw_pacing),
1116 	    OID_AUTO, "pace_enobuf_mult", CTLFLAG_RW,
1117 	    &rack_enobuf_hw_boost_mult, 0,
1118 	    "By how many time_betweens should we boost the pacing time if we see a ENOBUFS?");
1119 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1120 	    SYSCTL_CHILDREN(rack_hw_pacing),
1121 	    OID_AUTO, "pace_enobuf_max", CTLFLAG_RW,
1122 	    &rack_enobuf_hw_max, 2,
1123 	    "What is the max boost the pacing time if we see a ENOBUFS?");
1124 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1125 	    SYSCTL_CHILDREN(rack_hw_pacing),
1126 	    OID_AUTO, "pace_enobuf_min", CTLFLAG_RW,
1127 	    &rack_enobuf_hw_min, 2,
1128 	    "What is the min boost the pacing time if we see a ENOBUFS?");
1129 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1130 	    SYSCTL_CHILDREN(rack_hw_pacing),
1131 	    OID_AUTO, "enable", CTLFLAG_RW,
1132 	    &rack_enable_hw_pacing, 0,
1133 	    "Should RACK attempt to use hw pacing?");
1134 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1135 	    SYSCTL_CHILDREN(rack_hw_pacing),
1136 	    OID_AUTO, "rate_cap", CTLFLAG_RW,
1137 	    &rack_hw_rate_caps, 0,
1138 	    "Does the highest hardware pacing rate cap the rate we will send at??");
1139 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1140 	    SYSCTL_CHILDREN(rack_hw_pacing),
1141 	    OID_AUTO, "uncap_per", CTLFLAG_RW,
1142 	    &rack_hw_rate_cap_per, 0,
1143 	    "If you go over b/w by this amount you will be uncapped (0 = never)");
1144 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1145 	    SYSCTL_CHILDREN(rack_hw_pacing),
1146 	    OID_AUTO, "rate_min", CTLFLAG_RW,
1147 	    &rack_hw_rate_min, 0,
1148 	    "Do we need a minimum estimate of this many bytes per second in order to engage hw pacing?");
1149 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1150 	    SYSCTL_CHILDREN(rack_hw_pacing),
1151 	    OID_AUTO, "rate_to_low", CTLFLAG_RW,
1152 	    &rack_hw_rate_to_low, 0,
1153 	    "If we fall below this rate, dis-engage hw pacing?");
1154 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1155 	    SYSCTL_CHILDREN(rack_hw_pacing),
1156 	    OID_AUTO, "up_only", CTLFLAG_RW,
1157 	    &rack_hw_up_only, 0,
1158 	    "Do we allow hw pacing to lower the rate selected?");
1159 	rack_timely = SYSCTL_ADD_NODE(&rack_sysctl_ctx,
1160 	    SYSCTL_CHILDREN(rack_sysctl_root),
1161 	    OID_AUTO,
1162 	    "timely",
1163 	    CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
1164 	    "Rack Timely RTT Controls");
1165 	/* Timely based GP dynmics */
1166 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1167 	    SYSCTL_CHILDREN(rack_timely),
1168 	    OID_AUTO, "upper", CTLFLAG_RW,
1169 	    &rack_gp_per_bw_mul_up, 2,
1170 	    "Rack timely upper range for equal b/w (in percentage)");
1171 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1172 	    SYSCTL_CHILDREN(rack_timely),
1173 	    OID_AUTO, "lower", CTLFLAG_RW,
1174 	    &rack_gp_per_bw_mul_down, 4,
1175 	    "Rack timely lower range for equal b/w (in percentage)");
1176 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1177 	    SYSCTL_CHILDREN(rack_timely),
1178 	    OID_AUTO, "rtt_max_mul", CTLFLAG_RW,
1179 	    &rack_gp_rtt_maxmul, 3,
1180 	    "Rack timely multiplier of lowest rtt for rtt_max");
1181 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1182 	    SYSCTL_CHILDREN(rack_timely),
1183 	    OID_AUTO, "rtt_min_div", CTLFLAG_RW,
1184 	    &rack_gp_rtt_mindiv, 4,
1185 	    "Rack timely divisor used for rtt + (rtt * mul/divisor) for check for lower rtt");
1186 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1187 	    SYSCTL_CHILDREN(rack_timely),
1188 	    OID_AUTO, "rtt_min_mul", CTLFLAG_RW,
1189 	    &rack_gp_rtt_minmul, 1,
1190 	    "Rack timely multiplier used for rtt + (rtt * mul/divisor) for check for lower rtt");
1191 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1192 	    SYSCTL_CHILDREN(rack_timely),
1193 	    OID_AUTO, "decrease", CTLFLAG_RW,
1194 	    &rack_gp_decrease_per, 80,
1195 	    "Rack timely Beta value 80 = .8 (scaled by 100)");
1196 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1197 	    SYSCTL_CHILDREN(rack_timely),
1198 	    OID_AUTO, "increase", CTLFLAG_RW,
1199 	    &rack_gp_increase_per, 2,
1200 	    "Rack timely increase perentage of our GP multiplication factor");
1201 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1202 	    SYSCTL_CHILDREN(rack_timely),
1203 	    OID_AUTO, "lowerbound", CTLFLAG_RW,
1204 	    &rack_per_lower_bound, 50,
1205 	    "Rack timely lowest percentage we allow GP multiplier to fall to");
1206 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1207 	    SYSCTL_CHILDREN(rack_timely),
1208 	    OID_AUTO, "p5_upper", CTLFLAG_RW,
1209 	    &rack_gain_p5_ub, 250,
1210 	    "Profile 5 upper bound to timely gain");
1211 
1212 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1213 	    SYSCTL_CHILDREN(rack_timely),
1214 	    OID_AUTO, "upperboundss", CTLFLAG_RW,
1215 	    &rack_per_upper_bound_ss, 0,
1216 	    "Rack timely highest percentage we allow GP multiplier in SS to raise to (0 is no upperbound)");
1217 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1218 	    SYSCTL_CHILDREN(rack_timely),
1219 	    OID_AUTO, "upperboundca", CTLFLAG_RW,
1220 	    &rack_per_upper_bound_ca, 0,
1221 	    "Rack timely highest percentage we allow GP multiplier to CA raise to (0 is no upperbound)");
1222 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1223 	    SYSCTL_CHILDREN(rack_timely),
1224 	    OID_AUTO, "dynamicgp", CTLFLAG_RW,
1225 	    &rack_do_dyn_mul, 0,
1226 	    "Rack timely do we enable dynmaic timely goodput by default");
1227 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1228 	    SYSCTL_CHILDREN(rack_timely),
1229 	    OID_AUTO, "no_rec_red", CTLFLAG_RW,
1230 	    &rack_gp_no_rec_chg, 1,
1231 	    "Rack timely do we prohibit the recovery multiplier from being lowered");
1232 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1233 	    SYSCTL_CHILDREN(rack_timely),
1234 	    OID_AUTO, "red_clear_cnt", CTLFLAG_RW,
1235 	    &rack_timely_dec_clear, 6,
1236 	    "Rack timely what threshold do we count to before another boost during b/w decent");
1237 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1238 	    SYSCTL_CHILDREN(rack_timely),
1239 	    OID_AUTO, "max_push_rise", CTLFLAG_RW,
1240 	    &rack_timely_max_push_rise, 3,
1241 	    "Rack timely how many times do we push up with b/w increase");
1242 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1243 	    SYSCTL_CHILDREN(rack_timely),
1244 	    OID_AUTO, "max_push_drop", CTLFLAG_RW,
1245 	    &rack_timely_max_push_drop, 3,
1246 	    "Rack timely how many times do we push back on b/w decent");
1247 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1248 	    SYSCTL_CHILDREN(rack_timely),
1249 	    OID_AUTO, "min_segs", CTLFLAG_RW,
1250 	    &rack_timely_min_segs, 4,
1251 	    "Rack timely when setting the cwnd what is the min num segments");
1252 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1253 	    SYSCTL_CHILDREN(rack_timely),
1254 	    OID_AUTO, "nonstop", CTLFLAG_RW,
1255 	    &rack_timely_no_stopping, 0,
1256 	    "Rack timely don't stop increase");
1257 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1258 	    SYSCTL_CHILDREN(rack_timely),
1259 	    OID_AUTO, "dec_raise_thresh", CTLFLAG_RW,
1260 	    &rack_down_raise_thresh, 100,
1261 	    "If the CA or SS is below this threshold raise on the first 3 b/w lowers (0=always)");
1262 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1263 	    SYSCTL_CHILDREN(rack_timely),
1264 	    OID_AUTO, "bottom_drag_segs", CTLFLAG_RW,
1265 	    &rack_req_segs, 1,
1266 	    "Bottom dragging if not these many segments outstanding and room");
1267 
1268 	/* TLP and Rack related parameters */
1269 	rack_tlp = SYSCTL_ADD_NODE(&rack_sysctl_ctx,
1270 	    SYSCTL_CHILDREN(rack_sysctl_root),
1271 	    OID_AUTO,
1272 	    "tlp",
1273 	    CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
1274 	    "TLP and Rack related Controls");
1275 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1276 	    SYSCTL_CHILDREN(rack_tlp),
1277 	    OID_AUTO, "use_rrr", CTLFLAG_RW,
1278 	    &use_rack_rr, 1,
1279 	    "Do we use Rack Rapid Recovery");
1280 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1281 	    SYSCTL_CHILDREN(rack_tlp),
1282 	    OID_AUTO, "post_rec_labc", CTLFLAG_RW,
1283 	    &rack_max_abc_post_recovery, 2,
1284 	    "Since we do early recovery, do we override the l_abc to a value, if so what?");
1285 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1286 	    SYSCTL_CHILDREN(rack_tlp),
1287 	    OID_AUTO, "nonrxt_use_cr", CTLFLAG_RW,
1288 	    &rack_non_rxt_use_cr, 0,
1289 	    "Do we use ss/ca rate if in recovery we are transmitting a new data chunk");
1290 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1291 	    SYSCTL_CHILDREN(rack_tlp),
1292 	    OID_AUTO, "tlpmethod", CTLFLAG_RW,
1293 	    &rack_tlp_threshold_use, TLP_USE_TWO_ONE,
1294 	    "What method do we do for TLP time calc 0=no-de-ack-comp, 1=ID, 2=2.1, 3=2.2");
1295 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1296 	    SYSCTL_CHILDREN(rack_tlp),
1297 	    OID_AUTO, "limit", CTLFLAG_RW,
1298 	    &rack_tlp_limit, 2,
1299 	    "How many TLP's can be sent without sending new data");
1300 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1301 	    SYSCTL_CHILDREN(rack_tlp),
1302 	    OID_AUTO, "use_greater", CTLFLAG_RW,
1303 	    &rack_tlp_use_greater, 1,
1304 	    "Should we use the rack_rtt time if its greater than srtt");
1305 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1306 	    SYSCTL_CHILDREN(rack_tlp),
1307 	    OID_AUTO, "tlpminto", CTLFLAG_RW,
1308 	    &rack_tlp_min, 10000,
1309 	    "TLP minimum timeout per the specification (in microseconds)");
1310 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1311 	    SYSCTL_CHILDREN(rack_tlp),
1312 	    OID_AUTO, "send_oldest", CTLFLAG_RW,
1313 	    &rack_always_send_oldest, 0,
1314 	    "Should we always send the oldest TLP and RACK-TLP");
1315 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1316 	    SYSCTL_CHILDREN(rack_tlp),
1317 	    OID_AUTO, "tlp_cwnd_flag", CTLFLAG_RW,
1318 	    &rack_lower_cwnd_at_tlp, 0,
1319 	    "When a TLP completes a retran should we enter recovery");
1320 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1321 	    SYSCTL_CHILDREN(rack_tlp),
1322 	    OID_AUTO, "reorder_thresh", CTLFLAG_RW,
1323 	    &rack_reorder_thresh, 2,
1324 	    "What factor for rack will be added when seeing reordering (shift right)");
1325 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1326 	    SYSCTL_CHILDREN(rack_tlp),
1327 	    OID_AUTO, "rtt_tlp_thresh", CTLFLAG_RW,
1328 	    &rack_tlp_thresh, 1,
1329 	    "What divisor for TLP rtt/retran will be added (1=rtt, 2=1/2 rtt etc)");
1330 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1331 	    SYSCTL_CHILDREN(rack_tlp),
1332 	    OID_AUTO, "reorder_fade", CTLFLAG_RW,
1333 	    &rack_reorder_fade, 60000000,
1334 	    "Does reorder detection fade, if so how many microseconds (0 means never)");
1335 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1336 	    SYSCTL_CHILDREN(rack_tlp),
1337 	    OID_AUTO, "pktdelay", CTLFLAG_RW,
1338 	    &rack_pkt_delay, 1000,
1339 	    "Extra RACK time (in microseconds) besides reordering thresh");
1340 
1341 	/* Timer related controls */
1342 	rack_timers = SYSCTL_ADD_NODE(&rack_sysctl_ctx,
1343 	    SYSCTL_CHILDREN(rack_sysctl_root),
1344 	    OID_AUTO,
1345 	    "timers",
1346 	    CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
1347 	    "Timer related controls");
1348 	SYSCTL_ADD_U8(&rack_sysctl_ctx,
1349 	    SYSCTL_CHILDREN(rack_timers),
1350 	    OID_AUTO, "reset_ssth_rec_rto", CTLFLAG_RW,
1351 	    &rack_ssthresh_rest_rto_rec, 0,
1352 	    "When doing recovery -> rto -> recovery do we reset SSthresh?");
1353 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
1354 	    SYSCTL_CHILDREN(rack_timers),
1355 	    OID_AUTO, "rtt_divisor", CTLFLAG_RW,
1356 	    &rack_rtt_divisor, 2,
1357 	    "When calculating the rtt threshold what 1/N is a rtt that indicates reordering");
1358 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
1359 	    SYSCTL_CHILDREN(rack_timers),
1360 	    OID_AUTO, "scoreboard_thresh", CTLFLAG_RW,
1361 	    &rack_rxt_scoreboard_clear_thresh, 2,
1362 	    "How many RTO's are allowed before we clear the scoreboard");
1363 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
1364 	    SYSCTL_CHILDREN(rack_timers),
1365 	    OID_AUTO, "honor_hpts_min", CTLFLAG_RW,
1366 	    &rack_honors_hpts_min_to, 1,
1367 	    "Do rack pacing timers honor hpts min timeout");
1368 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
1369 	    SYSCTL_CHILDREN(rack_timers),
1370 	    OID_AUTO, "hpts_max_reduce", CTLFLAG_RW,
1371 	    &rack_max_reduce, 10,
1372 	    "Max percentage we will reduce pacing delay by for pacing when we are behind");
1373 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
1374 	    SYSCTL_CHILDREN(rack_timers),
1375 	    OID_AUTO, "persmin", CTLFLAG_RW,
1376 	    &rack_persist_min, 250000,
1377 	    "What is the minimum time in microseconds between persists");
1378 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
1379 	    SYSCTL_CHILDREN(rack_timers),
1380 	    OID_AUTO, "persmax", CTLFLAG_RW,
1381 	    &rack_persist_max, 2000000,
1382 	    "What is the largest delay in microseconds between persists");
1383 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1384 	    SYSCTL_CHILDREN(rack_timers),
1385 	    OID_AUTO, "delayed_ack", CTLFLAG_RW,
1386 	    &rack_delayed_ack_time, 40000,
1387 	    "Delayed ack time (40ms in microseconds)");
1388 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1389 	    SYSCTL_CHILDREN(rack_timers),
1390 	    OID_AUTO, "minrto", CTLFLAG_RW,
1391 	    &rack_rto_min, 30000,
1392 	    "Minimum RTO in microseconds -- set with caution below 1000 due to TLP");
1393 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1394 	    SYSCTL_CHILDREN(rack_timers),
1395 	    OID_AUTO, "maxrto", CTLFLAG_RW,
1396 	    &rack_rto_max, 4000000,
1397 	    "Maximum RTO in microseconds -- should be at least as large as min_rto");
1398 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1399 	    SYSCTL_CHILDREN(rack_timers),
1400 	    OID_AUTO, "minto", CTLFLAG_RW,
1401 	    &rack_min_to, 1000,
1402 	    "Minimum rack timeout in microseconds");
1403 	/* Measure controls */
1404 	rack_measure = SYSCTL_ADD_NODE(&rack_sysctl_ctx,
1405 	    SYSCTL_CHILDREN(rack_sysctl_root),
1406 	    OID_AUTO,
1407 	    "measure",
1408 	    CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
1409 	    "Measure related controls");
1410 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1411 	    SYSCTL_CHILDREN(rack_measure),
1412 	    OID_AUTO, "wma_divisor", CTLFLAG_RW,
1413 	    &rack_wma_divisor, 8,
1414 	    "When doing b/w calculation what is the  divisor for the WMA");
1415 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1416 	    SYSCTL_CHILDREN(rack_measure),
1417 	    OID_AUTO, "end_cwnd", CTLFLAG_RW,
1418 	    &rack_cwnd_block_ends_measure, 0,
1419 	    "Does a cwnd just-return end the measurement window (app limited)");
1420 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1421 	    SYSCTL_CHILDREN(rack_measure),
1422 	    OID_AUTO, "end_rwnd", CTLFLAG_RW,
1423 	    &rack_rwnd_block_ends_measure, 0,
1424 	    "Does an rwnd just-return end the measurement window (app limited -- not persists)");
1425 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
1426 	    SYSCTL_CHILDREN(rack_measure),
1427 	    OID_AUTO, "min_target", CTLFLAG_RW,
1428 	    &rack_def_data_window, 20,
1429 	    "What is the minimum target window (in mss) for a GP measurements");
1430 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
1431 	    SYSCTL_CHILDREN(rack_measure),
1432 	    OID_AUTO, "goal_bdp", CTLFLAG_RW,
1433 	    &rack_goal_bdp, 2,
1434 	    "What is the goal BDP to measure");
1435 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
1436 	    SYSCTL_CHILDREN(rack_measure),
1437 	    OID_AUTO, "min_srtts", CTLFLAG_RW,
1438 	    &rack_min_srtts, 1,
1439 	    "What is the goal BDP to measure");
1440 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
1441 	    SYSCTL_CHILDREN(rack_measure),
1442 	    OID_AUTO, "min_measure_tim", CTLFLAG_RW,
1443 	    &rack_min_measure_usec, 0,
1444 	    "What is the Minimum time time for a measurement if 0, this is off");
1445 	/* Features */
1446 	rack_features = SYSCTL_ADD_NODE(&rack_sysctl_ctx,
1447 	    SYSCTL_CHILDREN(rack_sysctl_root),
1448 	    OID_AUTO,
1449 	    "features",
1450 	    CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
1451 	    "Feature controls");
1452 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1453 	    SYSCTL_CHILDREN(rack_features),
1454 	    OID_AUTO, "hybrid_set_maxseg", CTLFLAG_RW,
1455 	    &rack_hybrid_allow_set_maxseg, 0,
1456 	    "Should hybrid pacing allow the setmss command");
1457 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1458 	    SYSCTL_CHILDREN(rack_features),
1459 	    OID_AUTO, "cmpack", CTLFLAG_RW,
1460 	    &rack_use_cmp_acks, 1,
1461 	    "Should RACK have LRO send compressed acks");
1462 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1463 	    SYSCTL_CHILDREN(rack_features),
1464 	    OID_AUTO, "fsb", CTLFLAG_RW,
1465 	    &rack_use_fsb, 1,
1466 	    "Should RACK use the fast send block?");
1467 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1468 	    SYSCTL_CHILDREN(rack_features),
1469 	    OID_AUTO, "rfo", CTLFLAG_RW,
1470 	    &rack_use_rfo, 1,
1471 	    "Should RACK use rack_fast_output()?");
1472 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1473 	    SYSCTL_CHILDREN(rack_features),
1474 	    OID_AUTO, "rsmrfo", CTLFLAG_RW,
1475 	    &rack_use_rsm_rfo, 1,
1476 	    "Should RACK use rack_fast_rsm_output()?");
1477 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1478 	    SYSCTL_CHILDREN(rack_features),
1479 	    OID_AUTO, "non_paced_lro_queue", CTLFLAG_RW,
1480 	    &rack_enable_mqueue_for_nonpaced, 0,
1481 	    "Should RACK use mbuf queuing for non-paced connections");
1482 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1483 	    SYSCTL_CHILDREN(rack_features),
1484 	    OID_AUTO, "hystartplusplus", CTLFLAG_RW,
1485 	    &rack_do_hystart, 0,
1486 	    "Should RACK enable HyStart++ on connections?");
1487 	/* Misc rack controls */
1488 	rack_misc = SYSCTL_ADD_NODE(&rack_sysctl_ctx,
1489 	    SYSCTL_CHILDREN(rack_sysctl_root),
1490 	    OID_AUTO,
1491 	    "misc",
1492 	    CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
1493 	    "Misc related controls");
1494 #ifdef TCP_ACCOUNTING
1495 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1496 	    SYSCTL_CHILDREN(rack_misc),
1497 	    OID_AUTO, "tcp_acct", CTLFLAG_RW,
1498 	    &rack_tcp_accounting, 0,
1499 	    "Should we turn on TCP accounting for all rack sessions?");
1500 #endif
1501 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1502 	    SYSCTL_CHILDREN(rack_misc),
1503 	    OID_AUTO, "dnd", CTLFLAG_RW,
1504 	    &rack_dnd_default, 0,
1505 	    "Do not disturb default for rack_rrr = 3");
1506 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1507 	    SYSCTL_CHILDREN(rack_misc),
1508 	    OID_AUTO, "rxt_controls", CTLFLAG_RW,
1509 	    &rack_rxt_controls, 0,
1510 	    "Retransmit sending size controls (valid  values 0, 1, 2 default=1)?");
1511 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1512 	    SYSCTL_CHILDREN(rack_misc),
1513 	    OID_AUTO, "rack_hibeta", CTLFLAG_RW,
1514 	    &rack_hibeta_setting, 0,
1515 	    "Do we ue a high beta (80 instead of 50)?");
1516 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1517 	    SYSCTL_CHILDREN(rack_misc),
1518 	    OID_AUTO, "apply_rtt_with_low_conf", CTLFLAG_RW,
1519 	    &rack_apply_rtt_with_reduced_conf, 0,
1520 	    "When a persist or keep-alive probe is not answered do we calculate rtt on subsequent answers?");
1521 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1522 	    SYSCTL_CHILDREN(rack_misc),
1523 	    OID_AUTO, "rack_dsack_ctl", CTLFLAG_RW,
1524 	    &rack_dsack_std_based, 3,
1525 	    "How do we process dsack with respect to rack timers, bit field, 3 is standards based?");
1526 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1527 	    SYSCTL_CHILDREN(rack_misc),
1528 	    OID_AUTO, "prr_addback_max", CTLFLAG_RW,
1529 	    &rack_prr_addbackmax, 2,
1530 	    "What is the maximum number of MSS we allow to be added back if prr can't send all its data?");
1531 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1532 	    SYSCTL_CHILDREN(rack_misc),
1533 	    OID_AUTO, "stats_gets_ms", CTLFLAG_RW,
1534 	    &rack_stats_gets_ms_rtt, 1,
1535 	    "What do we feed the stats framework (1 = ms_rtt, 0 = us_rtt, 2 = ms_rtt from hdwr, > 2 usec rtt from hdwr)?");
1536 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1537 	    SYSCTL_CHILDREN(rack_misc),
1538 	    OID_AUTO, "clientlowbuf", CTLFLAG_RW,
1539 	    &rack_client_low_buf, 0,
1540 	    "Client low buffer level (below this we are more aggressive in DGP exiting recovery (0 = off)?");
1541 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1542 	    SYSCTL_CHILDREN(rack_misc),
1543 	    OID_AUTO, "defprofile", CTLFLAG_RW,
1544 	    &rack_def_profile, 0,
1545 	    "Should RACK use a default profile (0=no, num == profile num)?");
1546 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1547 	    SYSCTL_CHILDREN(rack_misc),
1548 	    OID_AUTO, "shared_cwnd", CTLFLAG_RW,
1549 	    &rack_enable_shared_cwnd, 1,
1550 	    "Should RACK try to use the shared cwnd on connections where allowed");
1551 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1552 	    SYSCTL_CHILDREN(rack_misc),
1553 	    OID_AUTO, "limits_on_scwnd", CTLFLAG_RW,
1554 	    &rack_limits_scwnd, 1,
1555 	    "Should RACK place low end time limits on the shared cwnd feature");
1556 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1557 	    SYSCTL_CHILDREN(rack_misc),
1558 	    OID_AUTO, "no_prr", CTLFLAG_RW,
1559 	    &rack_disable_prr, 0,
1560 	    "Should RACK not use prr and only pace (must have pacing on)");
1561 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1562 	    SYSCTL_CHILDREN(rack_misc),
1563 	    OID_AUTO, "bb_verbose", CTLFLAG_RW,
1564 	    &rack_verbose_logging, 0,
1565 	    "Should RACK black box logging be verbose");
1566 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1567 	    SYSCTL_CHILDREN(rack_misc),
1568 	    OID_AUTO, "data_after_close", CTLFLAG_RW,
1569 	    &rack_ignore_data_after_close, 1,
1570 	    "Do we hold off sending a RST until all pending data is ack'd");
1571 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1572 	    SYSCTL_CHILDREN(rack_misc),
1573 	    OID_AUTO, "no_sack_needed", CTLFLAG_RW,
1574 	    &rack_sack_not_required, 1,
1575 	    "Do we allow rack to run on connections not supporting SACK");
1576 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1577 	    SYSCTL_CHILDREN(rack_misc),
1578 	    OID_AUTO, "prr_sendalot", CTLFLAG_RW,
1579 	    &rack_send_a_lot_in_prr, 1,
1580 	    "Send a lot in prr");
1581 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1582 	    SYSCTL_CHILDREN(rack_misc),
1583 	    OID_AUTO, "autoscale", CTLFLAG_RW,
1584 	    &rack_autosndbuf_inc, 20,
1585 	    "What percentage should rack scale up its snd buffer by?");
1586 
1587 	/* Counters */
1588 	rack_total_bytes = counter_u64_alloc(M_WAITOK);
1589 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1590 	    SYSCTL_CHILDREN(rack_counters),
1591 	    OID_AUTO, "totalbytes", CTLFLAG_RD,
1592 	    &rack_total_bytes,
1593 	    "Total number of bytes sent");
1594 	rack_fto_send = counter_u64_alloc(M_WAITOK);
1595 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1596 	    SYSCTL_CHILDREN(rack_counters),
1597 	    OID_AUTO, "fto_send", CTLFLAG_RD,
1598 	    &rack_fto_send, "Total number of rack_fast_output sends");
1599 	rack_fto_rsm_send = counter_u64_alloc(M_WAITOK);
1600 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1601 	    SYSCTL_CHILDREN(rack_counters),
1602 	    OID_AUTO, "fto_rsm_send", CTLFLAG_RD,
1603 	    &rack_fto_rsm_send, "Total number of rack_fast_rsm_output sends");
1604 	rack_nfto_resend = counter_u64_alloc(M_WAITOK);
1605 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1606 	    SYSCTL_CHILDREN(rack_counters),
1607 	    OID_AUTO, "nfto_resend", CTLFLAG_RD,
1608 	    &rack_nfto_resend, "Total number of rack_output retransmissions");
1609 	rack_non_fto_send = counter_u64_alloc(M_WAITOK);
1610 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1611 	    SYSCTL_CHILDREN(rack_counters),
1612 	    OID_AUTO, "nfto_send", CTLFLAG_RD,
1613 	    &rack_non_fto_send, "Total number of rack_output first sends");
1614 	rack_extended_rfo = counter_u64_alloc(M_WAITOK);
1615 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1616 	    SYSCTL_CHILDREN(rack_counters),
1617 	    OID_AUTO, "rfo_extended", CTLFLAG_RD,
1618 	    &rack_extended_rfo, "Total number of times we extended rfo");
1619 
1620 	rack_hw_pace_init_fail = counter_u64_alloc(M_WAITOK);
1621 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1622 	    SYSCTL_CHILDREN(rack_counters),
1623 	    OID_AUTO, "hwpace_init_fail", CTLFLAG_RD,
1624 	    &rack_hw_pace_init_fail, "Total number of times we failed to initialize hw pacing");
1625 	rack_hw_pace_lost = counter_u64_alloc(M_WAITOK);
1626 
1627 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1628 	    SYSCTL_CHILDREN(rack_counters),
1629 	    OID_AUTO, "hwpace_lost", CTLFLAG_RD,
1630 	    &rack_hw_pace_lost, "Total number of times we failed to initialize hw pacing");
1631 	rack_tlp_tot = counter_u64_alloc(M_WAITOK);
1632 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1633 	    SYSCTL_CHILDREN(rack_counters),
1634 	    OID_AUTO, "tlp_to_total", CTLFLAG_RD,
1635 	    &rack_tlp_tot,
1636 	    "Total number of tail loss probe expirations");
1637 	rack_tlp_newdata = counter_u64_alloc(M_WAITOK);
1638 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1639 	    SYSCTL_CHILDREN(rack_counters),
1640 	    OID_AUTO, "tlp_new", CTLFLAG_RD,
1641 	    &rack_tlp_newdata,
1642 	    "Total number of tail loss probe sending new data");
1643 	rack_tlp_retran = counter_u64_alloc(M_WAITOK);
1644 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1645 	    SYSCTL_CHILDREN(rack_counters),
1646 	    OID_AUTO, "tlp_retran", CTLFLAG_RD,
1647 	    &rack_tlp_retran,
1648 	    "Total number of tail loss probe sending retransmitted data");
1649 	rack_tlp_retran_bytes = counter_u64_alloc(M_WAITOK);
1650 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1651 	    SYSCTL_CHILDREN(rack_counters),
1652 	    OID_AUTO, "tlp_retran_bytes", CTLFLAG_RD,
1653 	    &rack_tlp_retran_bytes,
1654 	    "Total bytes of tail loss probe sending retransmitted data");
1655 	rack_to_tot = counter_u64_alloc(M_WAITOK);
1656 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1657 	    SYSCTL_CHILDREN(rack_counters),
1658 	    OID_AUTO, "rack_to_tot", CTLFLAG_RD,
1659 	    &rack_to_tot,
1660 	    "Total number of times the rack to expired");
1661 	rack_saw_enobuf = counter_u64_alloc(M_WAITOK);
1662 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1663 	    SYSCTL_CHILDREN(rack_counters),
1664 	    OID_AUTO, "saw_enobufs", CTLFLAG_RD,
1665 	    &rack_saw_enobuf,
1666 	    "Total number of times a sends returned enobuf for non-hdwr paced connections");
1667 	rack_saw_enobuf_hw = counter_u64_alloc(M_WAITOK);
1668 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1669 	    SYSCTL_CHILDREN(rack_counters),
1670 	    OID_AUTO, "saw_enobufs_hw", CTLFLAG_RD,
1671 	    &rack_saw_enobuf_hw,
1672 	    "Total number of times a send returned enobuf for hdwr paced connections");
1673 	rack_saw_enetunreach = counter_u64_alloc(M_WAITOK);
1674 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1675 	    SYSCTL_CHILDREN(rack_counters),
1676 	    OID_AUTO, "saw_enetunreach", CTLFLAG_RD,
1677 	    &rack_saw_enetunreach,
1678 	    "Total number of times a send received a enetunreachable");
1679 	rack_hot_alloc = counter_u64_alloc(M_WAITOK);
1680 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1681 	    SYSCTL_CHILDREN(rack_counters),
1682 	    OID_AUTO, "alloc_hot", CTLFLAG_RD,
1683 	    &rack_hot_alloc,
1684 	    "Total allocations from the top of our list");
1685 	rack_to_alloc = counter_u64_alloc(M_WAITOK);
1686 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1687 	    SYSCTL_CHILDREN(rack_counters),
1688 	    OID_AUTO, "allocs", CTLFLAG_RD,
1689 	    &rack_to_alloc,
1690 	    "Total allocations of tracking structures");
1691 	rack_to_alloc_hard = counter_u64_alloc(M_WAITOK);
1692 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1693 	    SYSCTL_CHILDREN(rack_counters),
1694 	    OID_AUTO, "allochard", CTLFLAG_RD,
1695 	    &rack_to_alloc_hard,
1696 	    "Total allocations done with sleeping the hard way");
1697 	rack_to_alloc_emerg = counter_u64_alloc(M_WAITOK);
1698 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1699 	    SYSCTL_CHILDREN(rack_counters),
1700 	    OID_AUTO, "allocemerg", CTLFLAG_RD,
1701 	    &rack_to_alloc_emerg,
1702 	    "Total allocations done from emergency cache");
1703 	rack_to_alloc_limited = counter_u64_alloc(M_WAITOK);
1704 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1705 	    SYSCTL_CHILDREN(rack_counters),
1706 	    OID_AUTO, "alloc_limited", CTLFLAG_RD,
1707 	    &rack_to_alloc_limited,
1708 	    "Total allocations dropped due to limit");
1709 	rack_alloc_limited_conns = counter_u64_alloc(M_WAITOK);
1710 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1711 	    SYSCTL_CHILDREN(rack_counters),
1712 	    OID_AUTO, "alloc_limited_conns", CTLFLAG_RD,
1713 	    &rack_alloc_limited_conns,
1714 	    "Connections with allocations dropped due to limit");
1715 	rack_split_limited = counter_u64_alloc(M_WAITOK);
1716 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1717 	    SYSCTL_CHILDREN(rack_counters),
1718 	    OID_AUTO, "split_limited", CTLFLAG_RD,
1719 	    &rack_split_limited,
1720 	    "Split allocations dropped due to limit");
1721 	rack_rxt_clamps_cwnd = counter_u64_alloc(M_WAITOK);
1722 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1723 	    SYSCTL_CHILDREN(rack_counters),
1724 	    OID_AUTO, "rxt_clamps_cwnd", CTLFLAG_RD,
1725 	    &rack_rxt_clamps_cwnd,
1726 	    "Number of times that excessive rxt clamped the cwnd down");
1727 	rack_rxt_clamps_cwnd_uniq = counter_u64_alloc(M_WAITOK);
1728 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1729 	    SYSCTL_CHILDREN(rack_counters),
1730 	    OID_AUTO, "rxt_clamps_cwnd_uniq", CTLFLAG_RD,
1731 	    &rack_rxt_clamps_cwnd_uniq,
1732 	    "Number of connections that have had excessive rxt clamped the cwnd down");
1733 	rack_persists_sends = counter_u64_alloc(M_WAITOK);
1734 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1735 	    SYSCTL_CHILDREN(rack_counters),
1736 	    OID_AUTO, "persist_sends", CTLFLAG_RD,
1737 	    &rack_persists_sends,
1738 	    "Number of times we sent a persist probe");
1739 	rack_persists_acks = counter_u64_alloc(M_WAITOK);
1740 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1741 	    SYSCTL_CHILDREN(rack_counters),
1742 	    OID_AUTO, "persist_acks", CTLFLAG_RD,
1743 	    &rack_persists_acks,
1744 	    "Number of times a persist probe was acked");
1745 	rack_persists_loss = counter_u64_alloc(M_WAITOK);
1746 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1747 	    SYSCTL_CHILDREN(rack_counters),
1748 	    OID_AUTO, "persist_loss", CTLFLAG_RD,
1749 	    &rack_persists_loss,
1750 	    "Number of times we detected a lost persist probe (no ack)");
1751 	rack_persists_lost_ends = counter_u64_alloc(M_WAITOK);
1752 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1753 	    SYSCTL_CHILDREN(rack_counters),
1754 	    OID_AUTO, "persist_loss_ends", CTLFLAG_RD,
1755 	    &rack_persists_lost_ends,
1756 	    "Number of lost persist probe (no ack) that the run ended with a PERSIST abort");
1757 #ifdef INVARIANTS
1758 	rack_adjust_map_bw = counter_u64_alloc(M_WAITOK);
1759 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1760 	    SYSCTL_CHILDREN(rack_counters),
1761 	    OID_AUTO, "map_adjust_req", CTLFLAG_RD,
1762 	    &rack_adjust_map_bw,
1763 	    "Number of times we hit the case where the sb went up and down on a sendmap entry");
1764 #endif
1765 	rack_multi_single_eq = counter_u64_alloc(M_WAITOK);
1766 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1767 	    SYSCTL_CHILDREN(rack_counters),
1768 	    OID_AUTO, "cmp_ack_equiv", CTLFLAG_RD,
1769 	    &rack_multi_single_eq,
1770 	    "Number of compressed acks total represented");
1771 	rack_proc_non_comp_ack = counter_u64_alloc(M_WAITOK);
1772 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1773 	    SYSCTL_CHILDREN(rack_counters),
1774 	    OID_AUTO, "cmp_ack_not", CTLFLAG_RD,
1775 	    &rack_proc_non_comp_ack,
1776 	    "Number of non compresseds acks that we processed");
1777 
1778 
1779 	rack_sack_proc_all = counter_u64_alloc(M_WAITOK);
1780 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1781 	    SYSCTL_CHILDREN(rack_counters),
1782 	    OID_AUTO, "sack_long", CTLFLAG_RD,
1783 	    &rack_sack_proc_all,
1784 	    "Total times we had to walk whole list for sack processing");
1785 	rack_sack_proc_restart = counter_u64_alloc(M_WAITOK);
1786 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1787 	    SYSCTL_CHILDREN(rack_counters),
1788 	    OID_AUTO, "sack_restart", CTLFLAG_RD,
1789 	    &rack_sack_proc_restart,
1790 	    "Total times we had to walk whole list due to a restart");
1791 	rack_sack_proc_short = counter_u64_alloc(M_WAITOK);
1792 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1793 	    SYSCTL_CHILDREN(rack_counters),
1794 	    OID_AUTO, "sack_short", CTLFLAG_RD,
1795 	    &rack_sack_proc_short,
1796 	    "Total times we took shortcut for sack processing");
1797 	rack_input_idle_reduces = counter_u64_alloc(M_WAITOK);
1798 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1799 	    SYSCTL_CHILDREN(rack_counters),
1800 	    OID_AUTO, "idle_reduce_oninput", CTLFLAG_RD,
1801 	    &rack_input_idle_reduces,
1802 	    "Total number of idle reductions on input");
1803 	rack_collapsed_win_seen = counter_u64_alloc(M_WAITOK);
1804 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1805 	    SYSCTL_CHILDREN(rack_counters),
1806 	    OID_AUTO, "collapsed_win_seen", CTLFLAG_RD,
1807 	    &rack_collapsed_win_seen,
1808 	    "Total number of collapsed window events seen (where our window shrinks)");
1809 
1810 	rack_collapsed_win = counter_u64_alloc(M_WAITOK);
1811 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1812 	    SYSCTL_CHILDREN(rack_counters),
1813 	    OID_AUTO, "collapsed_win", CTLFLAG_RD,
1814 	    &rack_collapsed_win,
1815 	    "Total number of collapsed window events where we mark packets");
1816 	rack_collapsed_win_rxt = counter_u64_alloc(M_WAITOK);
1817 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1818 	    SYSCTL_CHILDREN(rack_counters),
1819 	    OID_AUTO, "collapsed_win_rxt", CTLFLAG_RD,
1820 	    &rack_collapsed_win_rxt,
1821 	    "Total number of packets that were retransmitted");
1822 	rack_collapsed_win_rxt_bytes = counter_u64_alloc(M_WAITOK);
1823 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1824 	    SYSCTL_CHILDREN(rack_counters),
1825 	    OID_AUTO, "collapsed_win_bytes", CTLFLAG_RD,
1826 	    &rack_collapsed_win_rxt_bytes,
1827 	    "Total number of bytes that were retransmitted");
1828 	rack_try_scwnd = counter_u64_alloc(M_WAITOK);
1829 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1830 	    SYSCTL_CHILDREN(rack_counters),
1831 	    OID_AUTO, "tried_scwnd", CTLFLAG_RD,
1832 	    &rack_try_scwnd,
1833 	    "Total number of scwnd attempts");
1834 	COUNTER_ARRAY_ALLOC(rack_out_size, TCP_MSS_ACCT_SIZE, M_WAITOK);
1835 	SYSCTL_ADD_COUNTER_U64_ARRAY(&rack_sysctl_ctx, SYSCTL_CHILDREN(rack_sysctl_root),
1836 	    OID_AUTO, "outsize", CTLFLAG_RD,
1837 	    rack_out_size, TCP_MSS_ACCT_SIZE, "MSS send sizes");
1838 	COUNTER_ARRAY_ALLOC(rack_opts_arry, RACK_OPTS_SIZE, M_WAITOK);
1839 	SYSCTL_ADD_COUNTER_U64_ARRAY(&rack_sysctl_ctx, SYSCTL_CHILDREN(rack_sysctl_root),
1840 	    OID_AUTO, "opts", CTLFLAG_RD,
1841 	    rack_opts_arry, RACK_OPTS_SIZE, "RACK Option Stats");
1842 	SYSCTL_ADD_PROC(&rack_sysctl_ctx,
1843 	    SYSCTL_CHILDREN(rack_sysctl_root),
1844 	    OID_AUTO, "clear", CTLTYPE_UINT | CTLFLAG_RW | CTLFLAG_MPSAFE,
1845 	    &rack_clear_counter, 0, sysctl_rack_clear, "IU", "Clear counters");
1846 }
1847 
1848 static uint32_t
1849 rc_init_window(struct tcp_rack *rack)
1850 {
1851 	return (tcp_compute_initwnd(tcp_maxseg(rack->rc_tp)));
1852 
1853 }
1854 
1855 static uint64_t
1856 rack_get_fixed_pacing_bw(struct tcp_rack *rack)
1857 {
1858 	if (IN_FASTRECOVERY(rack->rc_tp->t_flags))
1859 		return (rack->r_ctl.rc_fixed_pacing_rate_rec);
1860 	else if (rack->r_ctl.cwnd_to_use < rack->rc_tp->snd_ssthresh)
1861 		return (rack->r_ctl.rc_fixed_pacing_rate_ss);
1862 	else
1863 		return (rack->r_ctl.rc_fixed_pacing_rate_ca);
1864 }
1865 
1866 static void
1867 rack_log_hybrid_bw(struct tcp_rack *rack, uint32_t seq, uint64_t cbw, uint64_t tim,
1868 	uint64_t data, uint8_t mod, uint16_t aux,
1869 	struct tcp_sendfile_track *cur, int line)
1870 {
1871 #ifdef TCP_REQUEST_TRK
1872 	int do_log = 0;
1873 
1874 	/*
1875 	 * The rate cap one is noisy and only should come out when normal BB logging
1876 	 * is enabled, the other logs (not RATE_CAP and NOT CAP_CALC) only come out
1877 	 * once per chunk and make up the BBpoint that can be turned on by the client.
1878 	 */
1879 	if ((mod == HYBRID_LOG_RATE_CAP) || (mod == HYBRID_LOG_CAP_CALC)) {
1880 		/*
1881 		 * The very noisy two need to only come out when
1882 		 * we have verbose logging on.
1883 		 */
1884 		if (rack_verbose_logging != 0)
1885 			do_log = tcp_bblogging_on(rack->rc_tp);
1886 		else
1887 			do_log = 0;
1888 	} else if (mod != HYBRID_LOG_BW_MEASURE) {
1889 		/*
1890 		 * All other less noisy logs here except the measure which
1891 		 * also needs to come out on the point and the log.
1892 		 */
1893 		do_log = tcp_bblogging_on(rack->rc_tp);
1894 	} else {
1895 		do_log = tcp_bblogging_point_on(rack->rc_tp, TCP_BBPOINT_REQ_LEVEL_LOGGING);
1896 	}
1897 
1898 	if (do_log) {
1899 		union tcp_log_stackspecific log;
1900 		struct timeval tv;
1901 		uint64_t lt_bw;
1902 
1903 		/* Convert our ms to a microsecond */
1904 		memset(&log, 0, sizeof(log));
1905 
1906 		log.u_bbr.cwnd_gain = line;
1907 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
1908 		log.u_bbr.rttProp = tim;
1909 		log.u_bbr.bw_inuse = cbw;
1910 		log.u_bbr.delRate = rack_get_gp_est(rack);
1911 		lt_bw = rack_get_lt_bw(rack);
1912 		log.u_bbr.flex1 = seq;
1913 		log.u_bbr.pacing_gain = aux;
1914 		/* lt_bw = < flex3 | flex2 > */
1915 		log.u_bbr.flex2 = (uint32_t)(lt_bw & 0x00000000ffffffff);
1916 		log.u_bbr.flex3 = (uint32_t)((lt_bw >> 32) & 0x00000000ffffffff);
1917 		/* Record the last obtained us rtt in inflight */
1918 		if (cur == NULL) {
1919 			/* Make sure we are looking at the right log if an overide comes in */
1920 			cur = rack->r_ctl.rc_last_sft;
1921 		}
1922 		if (rack->r_ctl.rack_rs.rs_flags != RACK_RTT_EMPTY)
1923 			log.u_bbr.inflight = rack->r_ctl.rack_rs.rs_us_rtt;
1924 		else {
1925 			/* Use the last known rtt i.e. the rack-rtt */
1926 			log.u_bbr.inflight = rack->rc_rack_rtt;
1927 		}
1928 		if (cur != NULL) {
1929 			uint64_t off;
1930 
1931 			log.u_bbr.cur_del_rate = cur->deadline;
1932 			if ((mod == HYBRID_LOG_RATE_CAP) || (mod == HYBRID_LOG_CAP_CALC)) {
1933 				/* start = < lost | pkt_epoch > */
1934 				log.u_bbr.pkt_epoch = (uint32_t)(cur->start & 0x00000000ffffffff);
1935 				log.u_bbr.lost = (uint32_t)((cur->start >> 32) & 0x00000000ffffffff);
1936 				log.u_bbr.flex6 = cur->start_seq;
1937 				log.u_bbr.pkts_out = cur->end_seq;
1938 			} else {
1939 				/* start = < lost | pkt_epoch > */
1940 				log.u_bbr.pkt_epoch = (uint32_t)(cur->start & 0x00000000ffffffff);
1941 				log.u_bbr.lost = (uint32_t)((cur->start >> 32) & 0x00000000ffffffff);
1942 				/* end = < pkts_out | flex6 > */
1943 				log.u_bbr.flex6 = (uint32_t)(cur->end & 0x00000000ffffffff);
1944 				log.u_bbr.pkts_out = (uint32_t)((cur->end >> 32) & 0x00000000ffffffff);
1945 			}
1946 			/* first_send = <lt_epoch | epoch> */
1947 			log.u_bbr.epoch = (uint32_t)(cur->first_send & 0x00000000ffffffff);
1948 			log.u_bbr.lt_epoch = (uint32_t)((cur->first_send >> 32) & 0x00000000ffffffff);
1949 			/* localtime = <delivered | applimited>*/
1950 			log.u_bbr.applimited = (uint32_t)(cur->localtime & 0x00000000ffffffff);
1951 			log.u_bbr.delivered = (uint32_t)((cur->localtime >> 32) & 0x00000000ffffffff);
1952 #ifdef TCP_REQUEST_TRK
1953 			off = (uint64_t)(cur) - (uint64_t)(&rack->rc_tp->t_tcpreq_info[0]);
1954 			log.u_bbr.bbr_substate = (uint8_t)(off / sizeof(struct tcp_sendfile_track));
1955 #endif
1956 			log.u_bbr.inhpts = 1;
1957 			log.u_bbr.flex4 = (uint32_t)(rack->rc_tp->t_sndbytes - cur->sent_at_fs);
1958 			log.u_bbr.flex5 = (uint32_t)(rack->rc_tp->t_snd_rxt_bytes - cur->rxt_at_fs);
1959 			log.u_bbr.flex7 = (uint16_t)cur->hybrid_flags;
1960 		} else {
1961 			log.u_bbr.flex7 = 0xffff;
1962 			log.u_bbr.cur_del_rate = 0xffffffffffffffff;
1963 		}
1964 		/*
1965 		 * Compose bbr_state to be a bit wise 0000ADHF
1966 		 * where A is the always_pace flag
1967 		 * where D is the dgp_on flag
1968 		 * where H is the hybrid_mode on flag
1969 		 * where F is the use_fixed_rate flag.
1970 		 */
1971 		log.u_bbr.bbr_state = rack->rc_always_pace;
1972 		log.u_bbr.bbr_state <<= 1;
1973 		log.u_bbr.bbr_state |= rack->dgp_on;
1974 		log.u_bbr.bbr_state <<= 1;
1975 		log.u_bbr.bbr_state |= rack->rc_hybrid_mode;
1976 		log.u_bbr.bbr_state <<= 1;
1977 		log.u_bbr.bbr_state |= rack->use_fixed_rate;
1978 		log.u_bbr.flex8 = mod;
1979 		tcp_log_event(rack->rc_tp, NULL,
1980 		    &rack->rc_inp->inp_socket->so_rcv,
1981 		    &rack->rc_inp->inp_socket->so_snd,
1982 		    TCP_HYBRID_PACING_LOG, 0,
1983 		    0, &log, false, NULL, __func__, __LINE__, &tv);
1984 
1985 	}
1986 #endif
1987 }
1988 
1989 #ifdef TCP_REQUEST_TRK
1990 static void
1991 rack_log_hybrid_sends(struct tcp_rack *rack, struct tcp_sendfile_track *cur, int line)
1992 {
1993 	if (tcp_bblogging_point_on(rack->rc_tp, TCP_BBPOINT_REQ_LEVEL_LOGGING)) {
1994 		union tcp_log_stackspecific log;
1995 		struct timeval tv;
1996 		uint64_t off;
1997 
1998 		/* Convert our ms to a microsecond */
1999 		memset(&log, 0, sizeof(log));
2000 
2001 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
2002 		log.u_bbr.delRate = cur->sent_at_fs;
2003 
2004 		if ((cur->flags & TCP_TRK_TRACK_FLG_LSND) == 0) {
2005 			/*
2006 			 * We did not get a new Rules Applied to set so
2007 			 * no overlapping send occured, this means the
2008 			 * current byte counts are correct.
2009 			 */
2010 			log.u_bbr.cur_del_rate = rack->rc_tp->t_sndbytes;
2011 			log.u_bbr.rttProp = rack->rc_tp->t_snd_rxt_bytes;
2012 		} else {
2013 			/*
2014 			 * Overlapping send case, we switched to a new
2015 			 * send and did a rules applied.
2016 			 */
2017 			log.u_bbr.cur_del_rate = cur->sent_at_ls;
2018 			log.u_bbr.rttProp = cur->rxt_at_ls;
2019 		}
2020 		log.u_bbr.bw_inuse = cur->rxt_at_fs;
2021 		log.u_bbr.cwnd_gain = line;
2022 		off = (uint64_t)(cur) - (uint64_t)(&rack->rc_tp->t_tcpreq_info[0]);
2023 		log.u_bbr.bbr_substate = (uint8_t)(off / sizeof(struct tcp_sendfile_track));
2024 		/* start = < flex1 | flex2 > */
2025 		log.u_bbr.flex2 = (uint32_t)(cur->start & 0x00000000ffffffff);
2026 		log.u_bbr.flex1 = (uint32_t)((cur->start >> 32) & 0x00000000ffffffff);
2027 		/* end = < flex3 | flex4 > */
2028 		log.u_bbr.flex4 = (uint32_t)(cur->end & 0x00000000ffffffff);
2029 		log.u_bbr.flex3 = (uint32_t)((cur->end >> 32) & 0x00000000ffffffff);
2030 
2031 		/* localtime = <delivered | applimited>*/
2032 		log.u_bbr.applimited = (uint32_t)(cur->localtime & 0x00000000ffffffff);
2033 		log.u_bbr.delivered = (uint32_t)((cur->localtime >> 32) & 0x00000000ffffffff);
2034 		/* client timestamp = <lt_epoch | epoch>*/
2035 		log.u_bbr.epoch = (uint32_t)(cur->timestamp & 0x00000000ffffffff);
2036 		log.u_bbr.lt_epoch = (uint32_t)((cur->timestamp >> 32) & 0x00000000ffffffff);
2037 		/* now set all the flags in */
2038 		log.u_bbr.pkts_out = cur->hybrid_flags;
2039 		log.u_bbr.lost = cur->playout_ms;
2040 		log.u_bbr.flex6 = cur->flags;
2041 		/*
2042 		 * Last send time  = <flex5 | pkt_epoch>  note we do not distinguish cases
2043 		 * where a false retransmit occurred so first_send  <-> lastsend may
2044 		 * include longer time then it actually took if we have a false rxt.
2045 		 */
2046 		log.u_bbr.pkt_epoch = (uint32_t)(rack->r_ctl.last_tmit_time_acked & 0x00000000ffffffff);
2047 		log.u_bbr.flex5 = (uint32_t)((rack->r_ctl.last_tmit_time_acked >> 32) & 0x00000000ffffffff);
2048 		/*
2049 		 * Compose bbr_state to be a bit wise 0000ADHF
2050 		 * where A is the always_pace flag
2051 		 * where D is the dgp_on flag
2052 		 * where H is the hybrid_mode on flag
2053 		 * where F is the use_fixed_rate flag.
2054 		 */
2055 		log.u_bbr.bbr_state = rack->rc_always_pace;
2056 		log.u_bbr.bbr_state <<= 1;
2057 		log.u_bbr.bbr_state |= rack->dgp_on;
2058 		log.u_bbr.bbr_state <<= 1;
2059 		log.u_bbr.bbr_state |= rack->rc_hybrid_mode;
2060 		log.u_bbr.bbr_state <<= 1;
2061 		log.u_bbr.bbr_state |= rack->use_fixed_rate;
2062 
2063 		log.u_bbr.flex8 = HYBRID_LOG_SENT_LOST;
2064 		tcp_log_event(rack->rc_tp, NULL,
2065 		    &rack->rc_inp->inp_socket->so_rcv,
2066 		    &rack->rc_inp->inp_socket->so_snd,
2067 		    TCP_HYBRID_PACING_LOG, 0,
2068 		    0, &log, false, NULL, __func__, __LINE__, &tv);
2069 	}
2070 }
2071 #endif
2072 
2073 static inline uint64_t
2074 rack_compensate_for_linerate(struct tcp_rack *rack, uint64_t bw)
2075 {
2076 	uint64_t ret_bw, ether;
2077 	uint64_t u_segsiz;
2078 
2079 	ether = rack->rc_tp->t_maxseg + sizeof(struct tcphdr);
2080 	if (rack->r_is_v6){
2081 #ifdef INET6
2082 		ether += sizeof(struct ip6_hdr);
2083 #endif
2084 		ether += 14;	/* eheader size 6+6+2 */
2085 	} else {
2086 #ifdef INET
2087 		ether += sizeof(struct ip);
2088 #endif
2089 		ether += 14;	/* eheader size 6+6+2 */
2090 	}
2091 	u_segsiz = (uint64_t)min(ctf_fixed_maxseg(rack->rc_tp), rack->r_ctl.rc_pace_min_segs);
2092 	ret_bw = bw;
2093 	ret_bw *= ether;
2094 	ret_bw /= u_segsiz;
2095 	return (ret_bw);
2096 }
2097 
2098 static void
2099 rack_rate_cap_bw(struct tcp_rack *rack, uint64_t *bw, int *capped)
2100 {
2101 #ifdef TCP_REQUEST_TRK
2102 	struct timeval tv;
2103 	uint64_t timenow, timeleft, lenleft, lengone, calcbw;
2104 #endif
2105 
2106 	if (rack->r_ctl.bw_rate_cap == 0)
2107 		return;
2108 #ifdef TCP_REQUEST_TRK
2109 	if (rack->rc_catch_up && rack->rc_hybrid_mode &&
2110 	    (rack->r_ctl.rc_last_sft != NULL)) {
2111 		/*
2112 		 * We have a dynamic cap. The original target
2113 		 * is in bw_rate_cap, but we need to look at
2114 		 * how long it is until we hit the deadline.
2115 		 */
2116 		struct tcp_sendfile_track *ent;
2117 
2118       		ent = rack->r_ctl.rc_last_sft;
2119 		microuptime(&tv);
2120 		timenow = tcp_tv_to_lusec(&tv);
2121 		if (timenow >= ent->deadline) {
2122 			/* No time left we do DGP only */
2123 			rack_log_hybrid_bw(rack, rack->rc_tp->snd_max,
2124 					   0, 0, 0, HYBRID_LOG_OUTOFTIME, 0, ent, __LINE__);
2125 			rack->r_ctl.bw_rate_cap = 0;
2126 			return;
2127 		}
2128 		/* We have the time */
2129 		timeleft = rack->r_ctl.rc_last_sft->deadline - timenow;
2130 		if (timeleft < HPTS_MSEC_IN_SEC) {
2131 			/* If there is less than a ms left just use DGPs rate */
2132 			rack_log_hybrid_bw(rack, rack->rc_tp->snd_max,
2133 					   0, timeleft, 0, HYBRID_LOG_OUTOFTIME, 0, ent, __LINE__);
2134 			rack->r_ctl.bw_rate_cap = 0;
2135 			return;
2136 		}
2137 		/*
2138 		 * Now lets find the amount of data left to send.
2139 		 *
2140 		 * Now ideally we want to use the end_seq to figure out how much more
2141 		 * but it might not be possible (only if we have the TRACK_FG_COMP on the entry..
2142 		 */
2143 		if (ent->flags & TCP_TRK_TRACK_FLG_COMP) {
2144 			if (SEQ_GT(ent->end_seq, rack->rc_tp->snd_una))
2145 				lenleft = ent->end_seq - rack->rc_tp->snd_una;
2146 			else {
2147 				/* TSNH, we should catch it at the send */
2148 				rack_log_hybrid_bw(rack, rack->rc_tp->snd_max,
2149 						   0, timeleft, 0, HYBRID_LOG_CAPERROR, 0, ent, __LINE__);
2150 				rack->r_ctl.bw_rate_cap = 0;
2151 				return;
2152 			}
2153 		} else {
2154 			/*
2155 			 * The hard way, figure out how much is gone and then
2156 			 * take that away from the total the client asked for
2157 			 * (thats off by tls overhead if this is tls).
2158 			 */
2159 			if (SEQ_GT(rack->rc_tp->snd_una, ent->start_seq))
2160 				lengone = rack->rc_tp->snd_una - ent->start_seq;
2161 			else
2162 				lengone = 0;
2163 			if (lengone < (ent->end - ent->start))
2164 				lenleft = (ent->end - ent->start) - lengone;
2165 			else {
2166 				/* TSNH, we should catch it at the send */
2167 				rack_log_hybrid_bw(rack, rack->rc_tp->snd_max,
2168 						   0, timeleft, lengone, HYBRID_LOG_CAPERROR, 0, ent, __LINE__);
2169 				rack->r_ctl.bw_rate_cap = 0;
2170 				return;
2171 			}
2172 		}
2173 		if (lenleft == 0) {
2174 			/* We have it all sent */
2175 			rack_log_hybrid_bw(rack, rack->rc_tp->snd_max,
2176 					   0, timeleft, lenleft, HYBRID_LOG_ALLSENT, 0, ent, __LINE__);
2177 			if (rack->r_ctl.bw_rate_cap)
2178 				goto normal_ratecap;
2179 			else
2180 				return;
2181 		}
2182 		calcbw = lenleft * HPTS_USEC_IN_SEC;
2183 		calcbw /= timeleft;
2184 		/* Now we must compensate for IP/TCP overhead */
2185 		calcbw = rack_compensate_for_linerate(rack, calcbw);
2186 		/* Update the bit rate cap */
2187 		rack->r_ctl.bw_rate_cap = calcbw;
2188 		if ((rack->r_ctl.rc_last_sft->hybrid_flags & TCP_HYBRID_PACING_S_MSS) &&
2189 		    (rack_hybrid_allow_set_maxseg == 1) &&
2190 		    ((rack->r_ctl.rc_last_sft->hybrid_flags & TCP_HYBRID_PACING_SETMSS) == 0)) {
2191 			/* Lets set in a smaller mss possibly here to match our rate-cap */
2192 			uint32_t orig_max;
2193 
2194 			orig_max = rack->r_ctl.rc_pace_max_segs;
2195 			rack->r_ctl.rc_last_sft->hybrid_flags |= TCP_HYBRID_PACING_SETMSS;
2196 			rack->r_ctl.rc_pace_max_segs = rack_get_pacing_len(rack, calcbw, ctf_fixed_maxseg(rack->rc_tp));
2197 			rack_log_type_pacing_sizes(rack->rc_tp, rack, rack->r_ctl.client_suggested_maxseg, orig_max, __LINE__, 5);
2198 		}
2199 		rack_log_hybrid_bw(rack, rack->rc_tp->snd_max,
2200 				   calcbw, timeleft, lenleft, HYBRID_LOG_CAP_CALC, 0, ent, __LINE__);
2201 		if ((calcbw > 0) && (*bw > calcbw)) {
2202 			rack_log_hybrid_bw(rack, rack->rc_tp->snd_max,
2203 					   *bw, ent->deadline, lenleft, HYBRID_LOG_RATE_CAP, 0, ent, __LINE__);
2204 			*capped = 1;
2205 			*bw = calcbw;
2206 		}
2207 		return;
2208 	}
2209 normal_ratecap:
2210 #endif
2211 	if ((rack->r_ctl.bw_rate_cap > 0) && (*bw > rack->r_ctl.bw_rate_cap)) {
2212 #ifdef TCP_REQUEST_TRK
2213 		if (rack->rc_hybrid_mode &&
2214 		    rack->rc_catch_up &&
2215 		    (rack->r_ctl.rc_last_sft != NULL) &&
2216 		    (rack->r_ctl.rc_last_sft->hybrid_flags & TCP_HYBRID_PACING_S_MSS) &&
2217 		    (rack_hybrid_allow_set_maxseg == 1) &&
2218 		    ((rack->r_ctl.rc_last_sft->hybrid_flags & TCP_HYBRID_PACING_SETMSS) == 0)) {
2219 			/* Lets set in a smaller mss possibly here to match our rate-cap */
2220 			uint32_t orig_max;
2221 
2222 			orig_max = rack->r_ctl.rc_pace_max_segs;
2223 			rack->r_ctl.rc_last_sft->hybrid_flags |= TCP_HYBRID_PACING_SETMSS;
2224 			rack->r_ctl.rc_pace_max_segs = rack_get_pacing_len(rack, rack->r_ctl.bw_rate_cap, ctf_fixed_maxseg(rack->rc_tp));
2225 			rack_log_type_pacing_sizes(rack->rc_tp, rack, rack->r_ctl.client_suggested_maxseg, orig_max, __LINE__, 5);
2226 		}
2227 #endif
2228 		*capped = 1;
2229 		*bw = rack->r_ctl.bw_rate_cap;
2230 		rack_log_hybrid_bw(rack, rack->rc_tp->snd_max,
2231 				   *bw, 0, 0,
2232 				   HYBRID_LOG_RATE_CAP, 1, NULL, __LINE__);
2233 	}
2234 }
2235 
2236 static uint64_t
2237 rack_get_gp_est(struct tcp_rack *rack)
2238 {
2239 	uint64_t bw, lt_bw, ret_bw;
2240 
2241 	if (rack->rc_gp_filled == 0) {
2242 		/*
2243 		 * We have yet no b/w measurement,
2244 		 * if we have a user set initial bw
2245 		 * return it. If we don't have that and
2246 		 * we have an srtt, use the tcp IW (10) to
2247 		 * calculate a fictional b/w over the SRTT
2248 		 * which is more or less a guess. Note
2249 		 * we don't use our IW from rack on purpose
2250 		 * so if we have like IW=30, we are not
2251 		 * calculating a "huge" b/w.
2252 		 */
2253 		uint64_t srtt;
2254 
2255 		if (rack->dis_lt_bw == 1)
2256 			lt_bw = 0;
2257 		else
2258 			lt_bw = rack_get_lt_bw(rack);
2259 		if (lt_bw) {
2260 			/*
2261 			 * No goodput bw but a long-term b/w does exist
2262 			 * lets use that.
2263 			 */
2264 			ret_bw = lt_bw;
2265 			goto compensate;
2266 		}
2267 		if (rack->r_ctl.init_rate)
2268 			return (rack->r_ctl.init_rate);
2269 
2270 		/* Ok lets come up with the IW guess, if we have a srtt */
2271 		if (rack->rc_tp->t_srtt == 0) {
2272 			/*
2273 			 * Go with old pacing method
2274 			 * i.e. burst mitigation only.
2275 			 */
2276 			return (0);
2277 		}
2278 		/* Ok lets get the initial TCP win (not racks) */
2279 		bw = tcp_compute_initwnd(tcp_maxseg(rack->rc_tp));
2280 		srtt = (uint64_t)rack->rc_tp->t_srtt;
2281 		bw *= (uint64_t)USECS_IN_SECOND;
2282 		bw /= srtt;
2283 		ret_bw = bw;
2284 		goto compensate;
2285 
2286 	}
2287 	if (rack->r_ctl.num_measurements >= RACK_REQ_AVG) {
2288 		/* Averaging is done, we can return the value */
2289 		bw = rack->r_ctl.gp_bw;
2290 	} else {
2291 		/* Still doing initial average must calculate */
2292 		bw = rack->r_ctl.gp_bw / max(rack->r_ctl.num_measurements, 1);
2293 	}
2294 	if (rack->dis_lt_bw) {
2295 		/* We are not using lt-bw */
2296 		ret_bw = bw;
2297 		goto compensate;
2298 	}
2299 	lt_bw = rack_get_lt_bw(rack);
2300 	if (lt_bw == 0) {
2301 		/* If we don't have one then equate it to the gp_bw */
2302 		lt_bw = rack->r_ctl.gp_bw;
2303 	}
2304 	if (rack->use_lesser_lt_bw) {
2305 		if (lt_bw < bw)
2306 			ret_bw = lt_bw;
2307 		else
2308 			ret_bw = bw;
2309 	} else {
2310 		if (lt_bw > bw)
2311 			ret_bw = lt_bw;
2312 		else
2313 			ret_bw = bw;
2314 	}
2315 	/*
2316 	 * Now lets compensate based on the TCP/IP overhead. Our
2317 	 * Goodput estimate does not include this so we must pace out
2318 	 * a bit faster since our pacing calculations do. The pacing
2319 	 * calculations use the base ETHERNET_SEGMENT_SIZE and the segsiz
2320 	 * we are using to do this, so we do that here in the opposite
2321 	 * direction as well. This means that if we are tunneled and the
2322 	 * segsiz is say 1200 bytes we will get quite a boost, but its
2323 	 * compensated for in the pacing time the opposite way.
2324 	 */
2325 compensate:
2326 	ret_bw = rack_compensate_for_linerate(rack, ret_bw);
2327 	return(ret_bw);
2328 }
2329 
2330 
2331 static uint64_t
2332 rack_get_bw(struct tcp_rack *rack)
2333 {
2334 	uint64_t bw;
2335 
2336 	if (rack->use_fixed_rate) {
2337 		/* Return the fixed pacing rate */
2338 		return (rack_get_fixed_pacing_bw(rack));
2339 	}
2340 	bw = rack_get_gp_est(rack);
2341 	return (bw);
2342 }
2343 
2344 static uint16_t
2345 rack_get_output_gain(struct tcp_rack *rack, struct rack_sendmap *rsm)
2346 {
2347 	if (rack->use_fixed_rate) {
2348 		return (100);
2349 	} else if (rack->in_probe_rtt && (rsm == NULL))
2350 		return (rack->r_ctl.rack_per_of_gp_probertt);
2351 	else if ((IN_FASTRECOVERY(rack->rc_tp->t_flags) &&
2352 		  rack->r_ctl.rack_per_of_gp_rec)) {
2353 		if (rsm) {
2354 			/* a retransmission always use the recovery rate */
2355 			return (rack->r_ctl.rack_per_of_gp_rec);
2356 		} else if (rack->rack_rec_nonrxt_use_cr) {
2357 			/* Directed to use the configured rate */
2358 			goto configured_rate;
2359 		} else if (rack->rack_no_prr &&
2360 			   (rack->r_ctl.rack_per_of_gp_rec > 100)) {
2361 			/* No PRR, lets just use the b/w estimate only */
2362 			return (100);
2363 		} else {
2364 			/*
2365 			 * Here we may have a non-retransmit but we
2366 			 * have no overrides, so just use the recovery
2367 			 * rate (prr is in effect).
2368 			 */
2369 			return (rack->r_ctl.rack_per_of_gp_rec);
2370 		}
2371 	}
2372 configured_rate:
2373 	/* For the configured rate we look at our cwnd vs the ssthresh */
2374 	if (rack->r_ctl.cwnd_to_use < rack->rc_tp->snd_ssthresh)
2375 		return (rack->r_ctl.rack_per_of_gp_ss);
2376 	else
2377 		return (rack->r_ctl.rack_per_of_gp_ca);
2378 }
2379 
2380 static void
2381 rack_log_dsack_event(struct tcp_rack *rack, uint8_t mod, uint32_t flex4, uint32_t flex5, uint32_t flex6)
2382 {
2383 	/*
2384 	 * Types of logs (mod value)
2385 	 * 1 = dsack_persists reduced by 1 via T-O or fast recovery exit.
2386 	 * 2 = a dsack round begins, persist is reset to 16.
2387 	 * 3 = a dsack round ends
2388 	 * 4 = Dsack option increases rack rtt flex5 is the srtt input, flex6 is thresh
2389 	 * 5 = Socket option set changing the control flags rc_rack_tmr_std_based, rc_rack_use_dsack
2390 	 * 6 = Final rack rtt, flex4 is srtt and flex6 is final limited thresh.
2391 	 */
2392 	if (tcp_bblogging_on(rack->rc_tp)) {
2393 		union tcp_log_stackspecific log;
2394 		struct timeval tv;
2395 
2396 		memset(&log, 0, sizeof(log));
2397 		log.u_bbr.flex1 = rack->rc_rack_tmr_std_based;
2398 		log.u_bbr.flex1 <<= 1;
2399 		log.u_bbr.flex1 |= rack->rc_rack_use_dsack;
2400 		log.u_bbr.flex1 <<= 1;
2401 		log.u_bbr.flex1 |= rack->rc_dsack_round_seen;
2402 		log.u_bbr.flex2 = rack->r_ctl.dsack_round_end;
2403 		log.u_bbr.flex3 = rack->r_ctl.num_dsack;
2404 		log.u_bbr.flex4 = flex4;
2405 		log.u_bbr.flex5 = flex5;
2406 		log.u_bbr.flex6 = flex6;
2407 		log.u_bbr.flex7 = rack->r_ctl.dsack_persist;
2408 		log.u_bbr.flex8 = mod;
2409 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
2410 		log.u_bbr.epoch = rack->r_ctl.current_round;
2411 		log.u_bbr.lt_epoch = rack->r_ctl.rc_considered_lost;
2412 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
2413 		    &rack->rc_inp->inp_socket->so_rcv,
2414 		    &rack->rc_inp->inp_socket->so_snd,
2415 		    RACK_DSACK_HANDLING, 0,
2416 		    0, &log, false, &tv);
2417 	}
2418 }
2419 
2420 static void
2421 rack_log_hdwr_pacing(struct tcp_rack *rack,
2422 		     uint64_t rate, uint64_t hw_rate, int line,
2423 		     int error, uint16_t mod)
2424 {
2425 	if (tcp_bblogging_on(rack->rc_tp)) {
2426 		union tcp_log_stackspecific log;
2427 		struct timeval tv;
2428 		const struct ifnet *ifp;
2429 		uint64_t ifp64;
2430 
2431 		memset(&log, 0, sizeof(log));
2432 		log.u_bbr.flex1 = ((hw_rate >> 32) & 0x00000000ffffffff);
2433 		log.u_bbr.flex2 = (hw_rate & 0x00000000ffffffff);
2434 		if (rack->r_ctl.crte) {
2435 			ifp = rack->r_ctl.crte->ptbl->rs_ifp;
2436 		} else if (rack->rc_inp->inp_route.ro_nh &&
2437 			   rack->rc_inp->inp_route.ro_nh->nh_ifp) {
2438 			ifp = rack->rc_inp->inp_route.ro_nh->nh_ifp;
2439 		} else
2440 			ifp = NULL;
2441 		if (ifp) {
2442 			ifp64 = (uintptr_t)ifp;
2443 			log.u_bbr.flex3 = ((ifp64  >> 32) & 0x00000000ffffffff);
2444 			log.u_bbr.flex4 = (ifp64 & 0x00000000ffffffff);
2445 		}
2446 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
2447 		log.u_bbr.bw_inuse = rate;
2448 		log.u_bbr.flex5 = line;
2449 		log.u_bbr.flex6 = error;
2450 		log.u_bbr.flex7 = mod;
2451 		log.u_bbr.applimited = rack->r_ctl.rc_pace_max_segs;
2452 		log.u_bbr.flex8 = rack->use_fixed_rate;
2453 		log.u_bbr.flex8 <<= 1;
2454 		log.u_bbr.flex8 |= rack->rack_hdrw_pacing;
2455 		log.u_bbr.pkts_out = rack->rc_tp->t_maxseg;
2456 		log.u_bbr.delRate = rack->r_ctl.crte_prev_rate;
2457 		if (rack->r_ctl.crte)
2458 			log.u_bbr.cur_del_rate = rack->r_ctl.crte->rate;
2459 		else
2460 			log.u_bbr.cur_del_rate = 0;
2461 		log.u_bbr.rttProp = rack->r_ctl.last_hw_bw_req;
2462 		log.u_bbr.epoch = rack->r_ctl.current_round;
2463 		log.u_bbr.lt_epoch = rack->r_ctl.rc_considered_lost;
2464 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
2465 		    &rack->rc_inp->inp_socket->so_rcv,
2466 		    &rack->rc_inp->inp_socket->so_snd,
2467 		    BBR_LOG_HDWR_PACE, 0,
2468 		    0, &log, false, &tv);
2469 	}
2470 }
2471 
2472 static uint64_t
2473 rack_get_output_bw(struct tcp_rack *rack, uint64_t bw, struct rack_sendmap *rsm, int *capped)
2474 {
2475 	/*
2476 	 * We allow rack_per_of_gp_xx to dictate our bw rate we want.
2477 	 */
2478 	uint64_t bw_est, high_rate;
2479 	uint64_t gain;
2480 
2481 	gain = (uint64_t)rack_get_output_gain(rack, rsm);
2482 	bw_est = bw * gain;
2483 	bw_est /= (uint64_t)100;
2484 	/* Never fall below the minimum (def 64kbps) */
2485 	if (bw_est < RACK_MIN_BW)
2486 		bw_est = RACK_MIN_BW;
2487 	if (rack->r_rack_hw_rate_caps) {
2488 		/* Rate caps are in place */
2489 		if (rack->r_ctl.crte != NULL) {
2490 			/* We have a hdwr rate already */
2491 			high_rate = tcp_hw_highest_rate(rack->r_ctl.crte);
2492 			if (bw_est >= high_rate) {
2493 				/* We are capping bw at the highest rate table entry */
2494 				if (rack_hw_rate_cap_per &&
2495 				    (((high_rate * (100 + rack_hw_rate_cap_per)) / 100) < bw_est)) {
2496 					rack->r_rack_hw_rate_caps = 0;
2497 					goto done;
2498 				}
2499 				rack_log_hdwr_pacing(rack,
2500 						     bw_est, high_rate, __LINE__,
2501 						     0, 3);
2502 				bw_est = high_rate;
2503 				if (capped)
2504 					*capped = 1;
2505 			}
2506 		} else if ((rack->rack_hdrw_pacing == 0) &&
2507 			   (rack->rack_hdw_pace_ena) &&
2508 			   (rack->rack_attempt_hdwr_pace == 0) &&
2509 			   (rack->rc_inp->inp_route.ro_nh != NULL) &&
2510 			   (rack->rc_inp->inp_route.ro_nh->nh_ifp != NULL)) {
2511 			/*
2512 			 * Special case, we have not yet attempted hardware
2513 			 * pacing, and yet we may, when we do, find out if we are
2514 			 * above the highest rate. We need to know the maxbw for the interface
2515 			 * in question (if it supports ratelimiting). We get back
2516 			 * a 0, if the interface is not found in the RL lists.
2517 			 */
2518 			high_rate = tcp_hw_highest_rate_ifp(rack->rc_inp->inp_route.ro_nh->nh_ifp, rack->rc_inp);
2519 			if (high_rate) {
2520 				/* Yep, we have a rate is it above this rate? */
2521 				if (bw_est > high_rate) {
2522 					bw_est = high_rate;
2523 					if (capped)
2524 						*capped = 1;
2525 				}
2526 			}
2527 		}
2528 	}
2529 done:
2530 	return (bw_est);
2531 }
2532 
2533 static void
2534 rack_log_retran_reason(struct tcp_rack *rack, struct rack_sendmap *rsm, uint32_t tsused, uint32_t thresh, int mod)
2535 {
2536 	if (tcp_bblogging_on(rack->rc_tp)) {
2537 		union tcp_log_stackspecific log;
2538 		struct timeval tv;
2539 
2540 		if ((mod != 1) && (rack_verbose_logging == 0))  {
2541 			/*
2542 			 * We get 3 values currently for mod
2543 			 * 1 - We are retransmitting and this tells the reason.
2544 			 * 2 - We are clearing a dup-ack count.
2545 			 * 3 - We are incrementing a dup-ack count.
2546 			 *
2547 			 * The clear/increment are only logged
2548 			 * if you have BBverbose on.
2549 			 */
2550 			return;
2551 		}
2552 		memset(&log, 0, sizeof(log));
2553 		log.u_bbr.flex1 = tsused;
2554 		log.u_bbr.flex2 = thresh;
2555 		log.u_bbr.flex3 = rsm->r_flags;
2556 		log.u_bbr.flex4 = rsm->r_dupack;
2557 		log.u_bbr.flex5 = rsm->r_start;
2558 		log.u_bbr.flex6 = rsm->r_end;
2559 		log.u_bbr.flex8 = mod;
2560 		log.u_bbr.inhpts = tcp_in_hpts(rack->rc_tp);
2561 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
2562 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
2563 		log.u_bbr.pkts_out = rack->r_ctl.rc_out_at_rto;
2564 		log.u_bbr.delivered = rack->r_ctl.rc_snd_max_at_rto;
2565 		log.u_bbr.pacing_gain = rack->r_must_retran;
2566 		log.u_bbr.epoch = rack->r_ctl.current_round;
2567 		log.u_bbr.lt_epoch = rack->r_ctl.rc_considered_lost;
2568 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
2569 		    &rack->rc_inp->inp_socket->so_rcv,
2570 		    &rack->rc_inp->inp_socket->so_snd,
2571 		    BBR_LOG_SETTINGS_CHG, 0,
2572 		    0, &log, false, &tv);
2573 	}
2574 }
2575 
2576 static void
2577 rack_log_to_start(struct tcp_rack *rack, uint32_t cts, uint32_t to, int32_t pacing_delay, uint8_t which)
2578 {
2579 	if (tcp_bblogging_on(rack->rc_tp)) {
2580 		union tcp_log_stackspecific log;
2581 		struct timeval tv;
2582 
2583 		memset(&log, 0, sizeof(log));
2584 		log.u_bbr.flex1 = rack->rc_tp->t_srtt;
2585 		log.u_bbr.flex2 = to;
2586 		log.u_bbr.flex3 = rack->r_ctl.rc_hpts_flags;
2587 		log.u_bbr.flex4 = pacing_delay;
2588 		log.u_bbr.flex5 = rack->rc_tp->t_hpts_slot;
2589 		log.u_bbr.flex6 = rack->rc_tp->t_rxtcur;
2590 		log.u_bbr.flex7 = rack->rc_in_persist;
2591 		log.u_bbr.flex8 = which;
2592 		if (rack->rack_no_prr)
2593 			log.u_bbr.pkts_out = 0;
2594 		else
2595 			log.u_bbr.pkts_out = rack->r_ctl.rc_prr_sndcnt;
2596 		log.u_bbr.inhpts = tcp_in_hpts(rack->rc_tp);
2597 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
2598 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
2599 		log.u_bbr.pkts_out = rack->r_ctl.rc_out_at_rto;
2600 		log.u_bbr.delivered = rack->r_ctl.rc_snd_max_at_rto;
2601 		log.u_bbr.pacing_gain = rack->r_must_retran;
2602 		log.u_bbr.cwnd_gain = rack->rack_deferred_inited;
2603 		log.u_bbr.pkt_epoch = rack->rc_has_collapsed;
2604 		log.u_bbr.lt_epoch = rack->rc_tp->t_rxtshift;
2605 		log.u_bbr.lost = rack_rto_min;
2606 		log.u_bbr.epoch = rack->r_ctl.roundends;
2607 		log.u_bbr.bw_inuse = rack->r_ctl.current_round;
2608 		log.u_bbr.bw_inuse <<= 32;
2609 		log.u_bbr.bw_inuse |= rack->r_ctl.rc_considered_lost;
2610 		log.u_bbr.applimited = rack->rc_tp->t_flags2;
2611 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
2612 		    &rack->rc_inp->inp_socket->so_rcv,
2613 		    &rack->rc_inp->inp_socket->so_snd,
2614 		    BBR_LOG_TIMERSTAR, 0,
2615 		    0, &log, false, &tv);
2616 	}
2617 }
2618 
2619 static void
2620 rack_log_to_event(struct tcp_rack *rack, int32_t to_num, struct rack_sendmap *rsm)
2621 {
2622 	if (tcp_bblogging_on(rack->rc_tp)) {
2623 		union tcp_log_stackspecific log;
2624 		struct timeval tv;
2625 
2626 		memset(&log, 0, sizeof(log));
2627 		log.u_bbr.inhpts = tcp_in_hpts(rack->rc_tp);
2628 		log.u_bbr.flex8 = to_num;
2629 		log.u_bbr.flex1 = rack->r_ctl.rc_rack_min_rtt;
2630 		log.u_bbr.flex2 = rack->rc_rack_rtt;
2631 		if (rsm == NULL)
2632 			log.u_bbr.flex3 = 0;
2633 		else
2634 			log.u_bbr.flex3 = rsm->r_end - rsm->r_start;
2635 		if (rack->rack_no_prr)
2636 			log.u_bbr.flex5 = 0;
2637 		else
2638 			log.u_bbr.flex5 = rack->r_ctl.rc_prr_sndcnt;
2639 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
2640 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
2641 		log.u_bbr.pkts_out = rack->r_ctl.rc_out_at_rto;
2642 		log.u_bbr.delivered = rack->r_ctl.rc_snd_max_at_rto;
2643 		log.u_bbr.pacing_gain = rack->r_must_retran;
2644 		log.u_bbr.bw_inuse = rack->r_ctl.current_round;
2645 		log.u_bbr.bw_inuse <<= 32;
2646 		log.u_bbr.bw_inuse |= rack->r_ctl.rc_considered_lost;
2647 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
2648 		    &rack->rc_inp->inp_socket->so_rcv,
2649 		    &rack->rc_inp->inp_socket->so_snd,
2650 		    BBR_LOG_RTO, 0,
2651 		    0, &log, false, &tv);
2652 	}
2653 }
2654 
2655 static void
2656 rack_log_map_chg(struct tcpcb *tp, struct tcp_rack *rack,
2657 		 struct rack_sendmap *prev,
2658 		 struct rack_sendmap *rsm,
2659 		 struct rack_sendmap *next,
2660 		 int flag, uint32_t th_ack, int line)
2661 {
2662 	if (rack_verbose_logging && tcp_bblogging_on(rack->rc_tp)) {
2663 		union tcp_log_stackspecific log;
2664 		struct timeval tv;
2665 
2666 		memset(&log, 0, sizeof(log));
2667 		log.u_bbr.flex8 = flag;
2668 		log.u_bbr.inhpts = tcp_in_hpts(rack->rc_tp);
2669 		log.u_bbr.cur_del_rate = (uintptr_t)prev;
2670 		log.u_bbr.delRate = (uintptr_t)rsm;
2671 		log.u_bbr.rttProp = (uintptr_t)next;
2672 		if (rsm)
2673 			log.u_bbr.flex1 = rsm->r_flags;
2674 		log.u_bbr.flex7 = 0;
2675 		if (prev) {
2676 			log.u_bbr.flex1 = prev->r_start;
2677 			log.u_bbr.flex2 = prev->r_end;
2678 			log.u_bbr.flex7 |= 0x4;
2679 		}
2680 		if (rsm) {
2681 			log.u_bbr.flex3 = rsm->r_start;
2682 			log.u_bbr.flex4 = rsm->r_end;
2683 			log.u_bbr.flex7 |= 0x2;
2684 		}
2685 		if (next) {
2686 			log.u_bbr.flex5 = next->r_start;
2687 			log.u_bbr.flex6 = next->r_end;
2688 			log.u_bbr.flex7 |= 0x1;
2689 		}
2690 		log.u_bbr.applimited = line;
2691 		log.u_bbr.pkts_out = th_ack;
2692 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
2693 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
2694 		if (rack->rack_no_prr)
2695 			log.u_bbr.lost = 0;
2696 		else
2697 			log.u_bbr.lost = rack->r_ctl.rc_prr_sndcnt;
2698 		log.u_bbr.bw_inuse = rack->r_ctl.current_round;
2699 		log.u_bbr.bw_inuse <<= 32;
2700 		log.u_bbr.bw_inuse |= rack->r_ctl.rc_considered_lost;
2701 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
2702 		    &rack->rc_inp->inp_socket->so_rcv,
2703 		    &rack->rc_inp->inp_socket->so_snd,
2704 		    TCP_LOG_MAPCHG, 0,
2705 		    0, &log, false, &tv);
2706 	}
2707 }
2708 
2709 static void
2710 rack_log_rtt_upd(struct tcpcb *tp, struct tcp_rack *rack, uint32_t t, uint32_t len,
2711 		 struct rack_sendmap *rsm, int conf)
2712 {
2713 	if (tcp_bblogging_on(tp)) {
2714 		union tcp_log_stackspecific log;
2715 		struct timeval tv;
2716 		memset(&log, 0, sizeof(log));
2717 		log.u_bbr.inhpts = tcp_in_hpts(rack->rc_tp);
2718 		log.u_bbr.flex1 = t;
2719 		log.u_bbr.flex2 = len;
2720 		log.u_bbr.flex3 = rack->r_ctl.rc_rack_min_rtt;
2721 		log.u_bbr.flex4 = rack->r_ctl.rack_rs.rs_rtt_lowest;
2722 		log.u_bbr.flex5 = rack->r_ctl.rack_rs.rs_rtt_highest;
2723 		log.u_bbr.flex6 = rack->r_ctl.rack_rs.rs_us_rtrcnt;
2724 		log.u_bbr.flex7 = conf;
2725 		log.u_bbr.rttProp = (uint64_t)rack->r_ctl.rack_rs.rs_rtt_tot;
2726 		log.u_bbr.flex8 = rack->r_ctl.rc_rate_sample_method;
2727 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
2728 		log.u_bbr.delivered = rack->r_ctl.rack_rs.rs_us_rtrcnt;
2729 		log.u_bbr.pkts_out = rack->r_ctl.rack_rs.rs_flags;
2730 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
2731 		if (rsm) {
2732 			log.u_bbr.pkt_epoch = rsm->r_start;
2733 			log.u_bbr.lost = rsm->r_end;
2734 			log.u_bbr.cwnd_gain = rsm->r_rtr_cnt;
2735 			/* We loose any upper of the 24 bits */
2736 			log.u_bbr.pacing_gain = (uint16_t)rsm->r_flags;
2737 		} else {
2738 			/* Its a SYN */
2739 			log.u_bbr.pkt_epoch = rack->rc_tp->iss;
2740 			log.u_bbr.lost = 0;
2741 			log.u_bbr.cwnd_gain = 0;
2742 			log.u_bbr.pacing_gain = 0;
2743 		}
2744 		/* Write out general bits of interest rrs here */
2745 		log.u_bbr.use_lt_bw = rack->rc_highly_buffered;
2746 		log.u_bbr.use_lt_bw <<= 1;
2747 		log.u_bbr.use_lt_bw |= rack->forced_ack;
2748 		log.u_bbr.use_lt_bw <<= 1;
2749 		log.u_bbr.use_lt_bw |= rack->rc_gp_dyn_mul;
2750 		log.u_bbr.use_lt_bw <<= 1;
2751 		log.u_bbr.use_lt_bw |= rack->in_probe_rtt;
2752 		log.u_bbr.use_lt_bw <<= 1;
2753 		log.u_bbr.use_lt_bw |= rack->measure_saw_probe_rtt;
2754 		log.u_bbr.use_lt_bw <<= 1;
2755 		log.u_bbr.use_lt_bw |= rack->app_limited_needs_set;
2756 		log.u_bbr.use_lt_bw <<= 1;
2757 		log.u_bbr.use_lt_bw |= rack->rc_gp_filled;
2758 		log.u_bbr.use_lt_bw <<= 1;
2759 		log.u_bbr.use_lt_bw |= rack->rc_dragged_bottom;
2760 		log.u_bbr.applimited = rack->r_ctl.rc_target_probertt_flight;
2761 		log.u_bbr.epoch = rack->r_ctl.rc_time_probertt_starts;
2762 		log.u_bbr.lt_epoch = rack->r_ctl.rc_time_probertt_entered;
2763 		log.u_bbr.cur_del_rate = rack->r_ctl.rc_lower_rtt_us_cts;
2764 		log.u_bbr.delRate = rack->r_ctl.rc_gp_srtt;
2765 		log.u_bbr.bw_inuse = tcp_tv_to_usec(&rack->r_ctl.act_rcv_time);
2766 		log.u_bbr.bw_inuse <<= 32;
2767 		if (rsm)
2768 			log.u_bbr.bw_inuse |= ((uint32_t)rsm->r_tim_lastsent[(rsm->r_rtr_cnt-1)]);
2769 		TCP_LOG_EVENTP(tp, NULL,
2770 		    &rack->rc_inp->inp_socket->so_rcv,
2771 		    &rack->rc_inp->inp_socket->so_snd,
2772 		    BBR_LOG_BBRRTT, 0,
2773 		    0, &log, false, &tv);
2774 
2775 
2776 	}
2777 }
2778 
2779 static void
2780 rack_log_rtt_sample(struct tcp_rack *rack, uint32_t rtt)
2781 {
2782 	/*
2783 	 * Log the rtt sample we are
2784 	 * applying to the srtt algorithm in
2785 	 * useconds.
2786 	 */
2787 	if (tcp_bblogging_on(rack->rc_tp)) {
2788 		union tcp_log_stackspecific log;
2789 		struct timeval tv;
2790 
2791 		/* Convert our ms to a microsecond */
2792 		memset(&log, 0, sizeof(log));
2793 		log.u_bbr.flex1 = rtt;
2794 		log.u_bbr.flex6 = rack->rc_tp->t_rxtcur;
2795 		log.u_bbr.flex7 = 1;
2796 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
2797 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
2798 		log.u_bbr.pkts_out = rack->r_ctl.rc_out_at_rto;
2799 		log.u_bbr.delivered = rack->r_ctl.rc_snd_max_at_rto;
2800 		log.u_bbr.pacing_gain = rack->r_must_retran;
2801 		/*
2802 		 * We capture in delRate the upper 32 bits as
2803 		 * the confidence level we had declared, and the
2804 		 * lower 32 bits as the actual RTT using the arrival
2805 		 * timestamp.
2806 		 */
2807 		log.u_bbr.delRate = rack->r_ctl.rack_rs.confidence;
2808 		log.u_bbr.delRate <<= 32;
2809 		log.u_bbr.delRate |= rack->r_ctl.rack_rs.rs_us_rtt;
2810 		/* Lets capture all the things that make up t_rtxcur */
2811 		log.u_bbr.applimited = rack_rto_min;
2812 		log.u_bbr.epoch = rack_rto_max;
2813 		log.u_bbr.lt_epoch = rack->r_ctl.timer_slop;
2814 		log.u_bbr.lost = rack_rto_min;
2815 		log.u_bbr.pkt_epoch = TICKS_2_USEC(tcp_rexmit_slop);
2816 		log.u_bbr.rttProp = RACK_REXMTVAL(rack->rc_tp);
2817 		log.u_bbr.bw_inuse = rack->r_ctl.act_rcv_time.tv_sec;
2818 		log.u_bbr.bw_inuse *= HPTS_USEC_IN_SEC;
2819 		log.u_bbr.bw_inuse += rack->r_ctl.act_rcv_time.tv_usec;
2820 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
2821 		    &rack->rc_inp->inp_socket->so_rcv,
2822 		    &rack->rc_inp->inp_socket->so_snd,
2823 		    TCP_LOG_RTT, 0,
2824 		    0, &log, false, &tv);
2825 	}
2826 }
2827 
2828 static void
2829 rack_log_rtt_sample_calc(struct tcp_rack *rack, uint32_t rtt, uint32_t send_time, uint32_t ack_time, int where)
2830 {
2831 	if (rack_verbose_logging && tcp_bblogging_on(rack->rc_tp)) {
2832 		union tcp_log_stackspecific log;
2833 		struct timeval tv;
2834 
2835 		/* Convert our ms to a microsecond */
2836 		memset(&log, 0, sizeof(log));
2837 		log.u_bbr.flex1 = rtt;
2838 		log.u_bbr.flex2 = send_time;
2839 		log.u_bbr.flex3 = ack_time;
2840 		log.u_bbr.flex4 = where;
2841 		log.u_bbr.flex7 = 2;
2842 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
2843 		log.u_bbr.bw_inuse = rack->r_ctl.current_round;
2844 		log.u_bbr.bw_inuse <<= 32;
2845 		log.u_bbr.bw_inuse |= rack->r_ctl.rc_considered_lost;
2846 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
2847 		    &rack->rc_inp->inp_socket->so_rcv,
2848 		    &rack->rc_inp->inp_socket->so_snd,
2849 		    TCP_LOG_RTT, 0,
2850 		    0, &log, false, &tv);
2851 	}
2852 }
2853 
2854 
2855 static void
2856 rack_log_rtt_sendmap(struct tcp_rack *rack, uint32_t idx, uint64_t tsv, uint32_t tsecho)
2857 {
2858 	if (rack_verbose_logging && tcp_bblogging_on(rack->rc_tp)) {
2859 		union tcp_log_stackspecific log;
2860 		struct timeval tv;
2861 
2862 		/* Convert our ms to a microsecond */
2863 		memset(&log, 0, sizeof(log));
2864 		log.u_bbr.flex1 = idx;
2865 		log.u_bbr.flex2 = rack_ts_to_msec(tsv);
2866 		log.u_bbr.flex3 = tsecho;
2867 		log.u_bbr.flex7 = 3;
2868 		log.u_bbr.rttProp = tsv;
2869 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
2870 		log.u_bbr.bw_inuse = rack->r_ctl.current_round;
2871 		log.u_bbr.bw_inuse <<= 32;
2872 		log.u_bbr.bw_inuse |= rack->r_ctl.rc_considered_lost;
2873 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
2874 		    &rack->rc_inp->inp_socket->so_rcv,
2875 		    &rack->rc_inp->inp_socket->so_snd,
2876 		    TCP_LOG_RTT, 0,
2877 		    0, &log, false, &tv);
2878 	}
2879 }
2880 
2881 
2882 static inline void
2883 rack_log_progress_event(struct tcp_rack *rack, struct tcpcb *tp, uint32_t tick,  int event, int line)
2884 {
2885 	if (rack_verbose_logging && tcp_bblogging_on(rack->rc_tp)) {
2886 		union tcp_log_stackspecific log;
2887 		struct timeval tv;
2888 
2889 		memset(&log, 0, sizeof(log));
2890 		log.u_bbr.inhpts = tcp_in_hpts(rack->rc_tp);
2891 		log.u_bbr.flex1 = line;
2892 		log.u_bbr.flex2 = tick;
2893 		log.u_bbr.flex3 = tp->t_maxunacktime;
2894 		log.u_bbr.flex4 = tp->t_acktime;
2895 		log.u_bbr.flex8 = event;
2896 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
2897 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
2898 		log.u_bbr.pkts_out = rack->r_ctl.rc_out_at_rto;
2899 		log.u_bbr.delivered = rack->r_ctl.rc_snd_max_at_rto;
2900 		log.u_bbr.pacing_gain = rack->r_must_retran;
2901 		log.u_bbr.bw_inuse = rack->r_ctl.current_round;
2902 		log.u_bbr.bw_inuse <<= 32;
2903 		log.u_bbr.bw_inuse |= rack->r_ctl.rc_considered_lost;
2904 		TCP_LOG_EVENTP(tp, NULL,
2905 		    &rack->rc_inp->inp_socket->so_rcv,
2906 		    &rack->rc_inp->inp_socket->so_snd,
2907 		    BBR_LOG_PROGRESS, 0,
2908 		    0, &log, false, &tv);
2909 	}
2910 }
2911 
2912 static void
2913 rack_log_type_bbrsnd(struct tcp_rack *rack, uint32_t len, uint32_t pacing_delay, uint32_t cts, struct timeval *tv, int line)
2914 {
2915 	if (rack_verbose_logging && tcp_bblogging_on(rack->rc_tp)) {
2916 		union tcp_log_stackspecific log;
2917 
2918 		memset(&log, 0, sizeof(log));
2919 		log.u_bbr.inhpts = tcp_in_hpts(rack->rc_tp);
2920 		log.u_bbr.flex1 = pacing_delay;
2921 		if (rack->rack_no_prr)
2922 			log.u_bbr.flex2 = 0;
2923 		else
2924 			log.u_bbr.flex2 = rack->r_ctl.rc_prr_sndcnt;
2925 		log.u_bbr.flex4 = rack->r_ctl.rc_hpts_flags;
2926 		log.u_bbr.flex6 = line;
2927 		log.u_bbr.flex7 = (0x0000ffff & rack->r_ctl.rc_hpts_flags);
2928 		log.u_bbr.flex8 = rack->rc_in_persist;
2929 		log.u_bbr.timeStamp = cts;
2930 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
2931 		log.u_bbr.pkts_out = rack->r_ctl.rc_out_at_rto;
2932 		log.u_bbr.delivered = rack->r_ctl.rc_snd_max_at_rto;
2933 		log.u_bbr.pacing_gain = rack->r_must_retran;
2934 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
2935 		    &rack->rc_inp->inp_socket->so_rcv,
2936 		    &rack->rc_inp->inp_socket->so_snd,
2937 		    BBR_LOG_BBRSND, 0,
2938 		    0, &log, false, tv);
2939 	}
2940 }
2941 
2942 static void
2943 rack_log_doseg_done(struct tcp_rack *rack, uint32_t cts, int32_t nxt_pkt, int32_t did_out, int way_out, int nsegs)
2944 {
2945 	if (tcp_bblogging_on(rack->rc_tp)) {
2946 		union tcp_log_stackspecific log;
2947 		struct timeval tv;
2948 
2949 		memset(&log, 0, sizeof(log));
2950 		log.u_bbr.flex1 = did_out;
2951 		log.u_bbr.flex2 = nxt_pkt;
2952 		log.u_bbr.flex3 = way_out;
2953 		log.u_bbr.flex4 = rack->r_ctl.rc_hpts_flags;
2954 		if (rack->rack_no_prr)
2955 			log.u_bbr.flex5 = 0;
2956 		else
2957 			log.u_bbr.flex5 = rack->r_ctl.rc_prr_sndcnt;
2958 		log.u_bbr.flex6 = nsegs;
2959 		log.u_bbr.applimited = rack->r_ctl.rc_pace_min_segs;
2960 		log.u_bbr.flex7 = rack->rc_ack_can_sendout_data;	/* Do we have ack-can-send set */
2961 		log.u_bbr.flex7 <<= 1;
2962 		log.u_bbr.flex7 |= rack->r_fast_output;	/* is fast output primed */
2963 		log.u_bbr.flex7 <<= 1;
2964 		log.u_bbr.flex7 |= rack->r_wanted_output;	/* Do we want output */
2965 		log.u_bbr.flex8 = rack->rc_in_persist;
2966 		log.u_bbr.inhpts = tcp_in_hpts(rack->rc_tp);
2967 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
2968 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
2969 		log.u_bbr.use_lt_bw = rack->r_ent_rec_ns;
2970 		log.u_bbr.use_lt_bw <<= 1;
2971 		log.u_bbr.use_lt_bw |= rack->r_might_revert;
2972 		log.u_bbr.pkts_out = rack->r_ctl.rc_out_at_rto;
2973 		log.u_bbr.delivered = rack->r_ctl.rc_snd_max_at_rto;
2974 		log.u_bbr.pacing_gain = rack->r_must_retran;
2975 		log.u_bbr.bw_inuse = rack->r_ctl.current_round;
2976 		log.u_bbr.bw_inuse <<= 32;
2977 		log.u_bbr.bw_inuse |= rack->r_ctl.rc_considered_lost;
2978 		log.u_bbr.epoch = rack->rc_inp->inp_socket->so_snd.sb_hiwat;
2979 		log.u_bbr.lt_epoch = rack->rc_inp->inp_socket->so_rcv.sb_hiwat;
2980 		log.u_bbr.lost = rack->rc_tp->t_srtt;
2981 		log.u_bbr.pkt_epoch = rack->rc_tp->rfbuf_cnt;
2982 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
2983 		    &rack->rc_inp->inp_socket->so_rcv,
2984 		    &rack->rc_inp->inp_socket->so_snd,
2985 		    BBR_LOG_DOSEG_DONE, 0,
2986 		    0, &log, false, &tv);
2987 	}
2988 }
2989 
2990 static void
2991 rack_log_type_pacing_sizes(struct tcpcb *tp, struct tcp_rack *rack, uint32_t arg1, uint32_t arg2, uint32_t arg3, uint8_t frm)
2992 {
2993 	if (tcp_bblogging_on(rack->rc_tp)) {
2994 		union tcp_log_stackspecific log;
2995 		struct timeval tv;
2996 
2997 		memset(&log, 0, sizeof(log));
2998 		log.u_bbr.flex1 = rack->r_ctl.rc_pace_min_segs;
2999 		log.u_bbr.flex3 = rack->r_ctl.rc_pace_max_segs;
3000 		log.u_bbr.flex4 = arg1;
3001 		log.u_bbr.flex5 = arg2;
3002 		log.u_bbr.flex7 = rack->r_ctl.rc_user_set_min_segs;
3003 		log.u_bbr.flex6 = arg3;
3004 		log.u_bbr.flex8 = frm;
3005 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
3006 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
3007 		log.u_bbr.pkts_out = rack->r_ctl.rc_out_at_rto;
3008 		log.u_bbr.applimited = rack->r_ctl.rc_sacked;
3009 		log.u_bbr.delivered = rack->r_ctl.rc_snd_max_at_rto;
3010 		log.u_bbr.pacing_gain = rack->r_must_retran;
3011 		TCP_LOG_EVENTP(tp, NULL, &tptosocket(tp)->so_rcv,
3012 		    &tptosocket(tp)->so_snd,
3013 		    TCP_HDWR_PACE_SIZE, 0, 0, &log, false, &tv);
3014 	}
3015 }
3016 
3017 static void
3018 rack_log_type_just_return(struct tcp_rack *rack, uint32_t cts, uint32_t tlen, uint32_t pacing_delay,
3019 			  uint8_t hpts_calling, int reason, uint32_t cwnd_to_use)
3020 {
3021 	if (tcp_bblogging_on(rack->rc_tp)) {
3022 		union tcp_log_stackspecific log;
3023 		struct timeval tv;
3024 
3025 		memset(&log, 0, sizeof(log));
3026 		log.u_bbr.inhpts = tcp_in_hpts(rack->rc_tp);
3027 		log.u_bbr.flex1 = pacing_delay;
3028 		log.u_bbr.flex2 = rack->r_ctl.rc_hpts_flags;
3029 		log.u_bbr.flex4 = reason;
3030 		if (rack->rack_no_prr)
3031 			log.u_bbr.flex5 = 0;
3032 		else
3033 			log.u_bbr.flex5 = rack->r_ctl.rc_prr_sndcnt;
3034 		log.u_bbr.flex7 = hpts_calling;
3035 		log.u_bbr.flex8 = rack->rc_in_persist;
3036 		log.u_bbr.lt_epoch = cwnd_to_use;
3037 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
3038 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
3039 		log.u_bbr.pkts_out = rack->r_ctl.rc_out_at_rto;
3040 		log.u_bbr.delivered = rack->r_ctl.rc_snd_max_at_rto;
3041 		log.u_bbr.pacing_gain = rack->r_must_retran;
3042 		log.u_bbr.cwnd_gain = rack->rc_has_collapsed;
3043 		log.u_bbr.bw_inuse = rack->r_ctl.current_round;
3044 		log.u_bbr.bw_inuse <<= 32;
3045 		log.u_bbr.bw_inuse |= rack->r_ctl.rc_considered_lost;
3046 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
3047 		    &rack->rc_inp->inp_socket->so_rcv,
3048 		    &rack->rc_inp->inp_socket->so_snd,
3049 		    BBR_LOG_JUSTRET, 0,
3050 		    tlen, &log, false, &tv);
3051 	}
3052 }
3053 
3054 static void
3055 rack_log_to_cancel(struct tcp_rack *rack, int32_t hpts_removed, int line, uint32_t us_cts,
3056 		   struct timeval *tv, uint32_t flags_on_entry)
3057 {
3058 	if (tcp_bblogging_on(rack->rc_tp)) {
3059 		union tcp_log_stackspecific log;
3060 
3061 		memset(&log, 0, sizeof(log));
3062 		log.u_bbr.inhpts = tcp_in_hpts(rack->rc_tp);
3063 		log.u_bbr.flex1 = line;
3064 		log.u_bbr.flex2 = rack->r_ctl.rc_last_output_to;
3065 		log.u_bbr.flex3 = flags_on_entry;
3066 		log.u_bbr.flex4 = us_cts;
3067 		if (rack->rack_no_prr)
3068 			log.u_bbr.flex5 = 0;
3069 		else
3070 			log.u_bbr.flex5 = rack->r_ctl.rc_prr_sndcnt;
3071 		log.u_bbr.flex6 = rack->rc_tp->t_rxtcur;
3072 		log.u_bbr.flex7 = hpts_removed;
3073 		log.u_bbr.flex8 = 1;
3074 		log.u_bbr.applimited = rack->r_ctl.rc_hpts_flags;
3075 		log.u_bbr.timeStamp = us_cts;
3076 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
3077 		log.u_bbr.pkts_out = rack->r_ctl.rc_out_at_rto;
3078 		log.u_bbr.delivered = rack->r_ctl.rc_snd_max_at_rto;
3079 		log.u_bbr.pacing_gain = rack->r_must_retran;
3080 		log.u_bbr.bw_inuse = rack->r_ctl.current_round;
3081 		log.u_bbr.bw_inuse <<= 32;
3082 		log.u_bbr.bw_inuse |= rack->r_ctl.rc_considered_lost;
3083 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
3084 		    &rack->rc_inp->inp_socket->so_rcv,
3085 		    &rack->rc_inp->inp_socket->so_snd,
3086 		    BBR_LOG_TIMERCANC, 0,
3087 		    0, &log, false, tv);
3088 	}
3089 }
3090 
3091 static void
3092 rack_log_alt_to_to_cancel(struct tcp_rack *rack,
3093 			  uint32_t flex1, uint32_t flex2,
3094 			  uint32_t flex3, uint32_t flex4,
3095 			  uint32_t flex5, uint32_t flex6,
3096 			  uint16_t flex7, uint8_t mod)
3097 {
3098 	if (tcp_bblogging_on(rack->rc_tp)) {
3099 		union tcp_log_stackspecific log;
3100 		struct timeval tv;
3101 
3102 		if (mod == 1) {
3103 			/* No you can't use 1, its for the real to cancel */
3104 			return;
3105 		}
3106 		memset(&log, 0, sizeof(log));
3107 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
3108 		log.u_bbr.flex1 = flex1;
3109 		log.u_bbr.flex2 = flex2;
3110 		log.u_bbr.flex3 = flex3;
3111 		log.u_bbr.flex4 = flex4;
3112 		log.u_bbr.flex5 = flex5;
3113 		log.u_bbr.flex6 = flex6;
3114 		log.u_bbr.flex7 = flex7;
3115 		log.u_bbr.flex8 = mod;
3116 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
3117 		    &rack->rc_inp->inp_socket->so_rcv,
3118 		    &rack->rc_inp->inp_socket->so_snd,
3119 		    BBR_LOG_TIMERCANC, 0,
3120 		    0, &log, false, &tv);
3121 	}
3122 }
3123 
3124 static void
3125 rack_log_to_processing(struct tcp_rack *rack, uint32_t cts, int32_t ret, int32_t timers)
3126 {
3127 	if (rack_verbose_logging && tcp_bblogging_on(rack->rc_tp)) {
3128 		union tcp_log_stackspecific log;
3129 		struct timeval tv;
3130 
3131 		memset(&log, 0, sizeof(log));
3132 		log.u_bbr.flex1 = timers;
3133 		log.u_bbr.flex2 = ret;
3134 		log.u_bbr.flex3 = rack->r_ctl.rc_timer_exp;
3135 		log.u_bbr.flex4 = rack->r_ctl.rc_hpts_flags;
3136 		log.u_bbr.flex5 = cts;
3137 		if (rack->rack_no_prr)
3138 			log.u_bbr.flex6 = 0;
3139 		else
3140 			log.u_bbr.flex6 = rack->r_ctl.rc_prr_sndcnt;
3141 		log.u_bbr.pkts_out = rack->r_ctl.rc_out_at_rto;
3142 		log.u_bbr.delivered = rack->r_ctl.rc_snd_max_at_rto;
3143 		log.u_bbr.pacing_gain = rack->r_must_retran;
3144 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
3145 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
3146 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
3147 		    &rack->rc_inp->inp_socket->so_rcv,
3148 		    &rack->rc_inp->inp_socket->so_snd,
3149 		    BBR_LOG_TO_PROCESS, 0,
3150 		    0, &log, false, &tv);
3151 	}
3152 }
3153 
3154 static void
3155 rack_log_to_prr(struct tcp_rack *rack, int frm, int orig_cwnd, int line)
3156 {
3157 	if (tcp_bblogging_on(rack->rc_tp)) {
3158 		union tcp_log_stackspecific log;
3159 		struct timeval tv;
3160 
3161 		memset(&log, 0, sizeof(log));
3162 		log.u_bbr.flex1 = rack->r_ctl.rc_prr_out;
3163 		log.u_bbr.flex2 = rack->r_ctl.rc_prr_recovery_fs;
3164 		if (rack->rack_no_prr)
3165 			log.u_bbr.flex3 = 0;
3166 		else
3167 			log.u_bbr.flex3 = rack->r_ctl.rc_prr_sndcnt;
3168 		log.u_bbr.flex4 = rack->r_ctl.rc_prr_delivered;
3169 		log.u_bbr.flex5 = rack->r_ctl.rc_sacked;
3170 		log.u_bbr.flex6 = rack->r_ctl.rc_holes_rxt;
3171 		log.u_bbr.flex7 = line;
3172 		log.u_bbr.flex8 = frm;
3173 		log.u_bbr.pkts_out = orig_cwnd;
3174 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
3175 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
3176 		log.u_bbr.use_lt_bw = rack->r_ent_rec_ns;
3177 		log.u_bbr.use_lt_bw <<= 1;
3178 		log.u_bbr.use_lt_bw |= rack->r_might_revert;
3179 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
3180 		    &rack->rc_inp->inp_socket->so_rcv,
3181 		    &rack->rc_inp->inp_socket->so_snd,
3182 		    BBR_LOG_BBRUPD, 0,
3183 		    0, &log, false, &tv);
3184 	}
3185 }
3186 
3187 static void
3188 rack_counter_destroy(void)
3189 {
3190 	counter_u64_free(rack_total_bytes);
3191 	counter_u64_free(rack_fto_send);
3192 	counter_u64_free(rack_fto_rsm_send);
3193 	counter_u64_free(rack_nfto_resend);
3194 	counter_u64_free(rack_hw_pace_init_fail);
3195 	counter_u64_free(rack_hw_pace_lost);
3196 	counter_u64_free(rack_non_fto_send);
3197 	counter_u64_free(rack_extended_rfo);
3198 	counter_u64_free(rack_tlp_tot);
3199 	counter_u64_free(rack_tlp_newdata);
3200 	counter_u64_free(rack_tlp_retran);
3201 	counter_u64_free(rack_tlp_retran_bytes);
3202 	counter_u64_free(rack_to_tot);
3203 	counter_u64_free(rack_saw_enobuf);
3204 	counter_u64_free(rack_saw_enobuf_hw);
3205 	counter_u64_free(rack_saw_enetunreach);
3206 	counter_u64_free(rack_hot_alloc);
3207 	counter_u64_free(rack_to_alloc);
3208 	counter_u64_free(rack_to_alloc_hard);
3209 	counter_u64_free(rack_to_alloc_emerg);
3210 	counter_u64_free(rack_to_alloc_limited);
3211 	counter_u64_free(rack_alloc_limited_conns);
3212 	counter_u64_free(rack_split_limited);
3213 	counter_u64_free(rack_multi_single_eq);
3214 	counter_u64_free(rack_rxt_clamps_cwnd);
3215 	counter_u64_free(rack_rxt_clamps_cwnd_uniq);
3216 	counter_u64_free(rack_proc_non_comp_ack);
3217 	counter_u64_free(rack_sack_proc_all);
3218 	counter_u64_free(rack_sack_proc_restart);
3219 	counter_u64_free(rack_sack_proc_short);
3220 	counter_u64_free(rack_input_idle_reduces);
3221 	counter_u64_free(rack_collapsed_win);
3222 	counter_u64_free(rack_collapsed_win_rxt);
3223 	counter_u64_free(rack_collapsed_win_rxt_bytes);
3224 	counter_u64_free(rack_collapsed_win_seen);
3225 	counter_u64_free(rack_try_scwnd);
3226 	counter_u64_free(rack_persists_sends);
3227 	counter_u64_free(rack_persists_acks);
3228 	counter_u64_free(rack_persists_loss);
3229 	counter_u64_free(rack_persists_lost_ends);
3230 #ifdef INVARIANTS
3231 	counter_u64_free(rack_adjust_map_bw);
3232 #endif
3233 	COUNTER_ARRAY_FREE(rack_out_size, TCP_MSS_ACCT_SIZE);
3234 	COUNTER_ARRAY_FREE(rack_opts_arry, RACK_OPTS_SIZE);
3235 }
3236 
3237 static struct rack_sendmap *
3238 rack_alloc(struct tcp_rack *rack)
3239 {
3240 	struct rack_sendmap *rsm;
3241 
3242 	/*
3243 	 * First get the top of the list it in
3244 	 * theory is the "hottest" rsm we have,
3245 	 * possibly just freed by ack processing.
3246 	 */
3247 	if (rack->rc_free_cnt > rack_free_cache) {
3248 		rsm = TAILQ_FIRST(&rack->r_ctl.rc_free);
3249 		TAILQ_REMOVE(&rack->r_ctl.rc_free, rsm, r_tnext);
3250 		counter_u64_add(rack_hot_alloc, 1);
3251 		rack->rc_free_cnt--;
3252 		return (rsm);
3253 	}
3254 	/*
3255 	 * Once we get under our free cache we probably
3256 	 * no longer have a "hot" one available. Lets
3257 	 * get one from UMA.
3258 	 */
3259 	rsm = uma_zalloc(rack_zone, M_NOWAIT);
3260 	if (rsm) {
3261 		rack->r_ctl.rc_num_maps_alloced++;
3262 		counter_u64_add(rack_to_alloc, 1);
3263 		return (rsm);
3264 	}
3265 	/*
3266 	 * Dig in to our aux rsm's (the last two) since
3267 	 * UMA failed to get us one.
3268 	 */
3269 	if (rack->rc_free_cnt) {
3270 		counter_u64_add(rack_to_alloc_emerg, 1);
3271 		rsm = TAILQ_FIRST(&rack->r_ctl.rc_free);
3272 		TAILQ_REMOVE(&rack->r_ctl.rc_free, rsm, r_tnext);
3273 		rack->rc_free_cnt--;
3274 		return (rsm);
3275 	}
3276 	return (NULL);
3277 }
3278 
3279 static struct rack_sendmap *
3280 rack_alloc_full_limit(struct tcp_rack *rack)
3281 {
3282 	if ((V_tcp_map_entries_limit > 0) &&
3283 	    (rack->r_ctl.rc_num_maps_alloced >= V_tcp_map_entries_limit)) {
3284 		counter_u64_add(rack_to_alloc_limited, 1);
3285 		if (!rack->alloc_limit_reported) {
3286 			rack->alloc_limit_reported = 1;
3287 			counter_u64_add(rack_alloc_limited_conns, 1);
3288 		}
3289 		return (NULL);
3290 	}
3291 	return (rack_alloc(rack));
3292 }
3293 
3294 /* wrapper to allocate a sendmap entry, subject to a specific limit */
3295 static struct rack_sendmap *
3296 rack_alloc_limit(struct tcp_rack *rack, uint8_t limit_type)
3297 {
3298 	struct rack_sendmap *rsm;
3299 
3300 	if (limit_type) {
3301 		/* currently there is only one limit type */
3302 		if (rack->r_ctl.rc_split_limit > 0 &&
3303 		    rack->r_ctl.rc_num_split_allocs >= rack->r_ctl.rc_split_limit) {
3304 			counter_u64_add(rack_split_limited, 1);
3305 			if (!rack->alloc_limit_reported) {
3306 				rack->alloc_limit_reported = 1;
3307 				counter_u64_add(rack_alloc_limited_conns, 1);
3308 			}
3309 			return (NULL);
3310 		}
3311 	}
3312 
3313 	/* allocate and mark in the limit type, if set */
3314 	rsm = rack_alloc(rack);
3315 	if (rsm != NULL && limit_type) {
3316 		rsm->r_limit_type = limit_type;
3317 		rack->r_ctl.rc_num_split_allocs++;
3318 	}
3319 	return (rsm);
3320 }
3321 
3322 static void
3323 rack_free_trim(struct tcp_rack *rack)
3324 {
3325 	struct rack_sendmap *rsm;
3326 
3327 	/*
3328 	 * Free up all the tail entries until
3329 	 * we get our list down to the limit.
3330 	 */
3331 	while (rack->rc_free_cnt > rack_free_cache) {
3332 		rsm = TAILQ_LAST(&rack->r_ctl.rc_free, rack_head);
3333 		TAILQ_REMOVE(&rack->r_ctl.rc_free, rsm, r_tnext);
3334 		rack->rc_free_cnt--;
3335 		rack->r_ctl.rc_num_maps_alloced--;
3336 		uma_zfree(rack_zone, rsm);
3337 	}
3338 }
3339 
3340 static void
3341 rack_free(struct tcp_rack *rack, struct rack_sendmap *rsm)
3342 {
3343 	if (rsm->r_flags & RACK_APP_LIMITED) {
3344 		KASSERT((rack->r_ctl.rc_app_limited_cnt > 0),
3345 		    ("app_cnt %u, rsm %p", rack->r_ctl.rc_app_limited_cnt, rsm));
3346 		rack->r_ctl.rc_app_limited_cnt--;
3347 	}
3348 	if (rsm->r_limit_type) {
3349 		/* currently there is only one limit type */
3350 		rack->r_ctl.rc_num_split_allocs--;
3351 	}
3352 	if (rsm == rack->r_ctl.rc_first_appl) {
3353 		rack->r_ctl.cleared_app_ack_seq = rsm->r_end;
3354 		rack->r_ctl.cleared_app_ack = 1;
3355 		if (rack->r_ctl.rc_app_limited_cnt == 0)
3356 			rack->r_ctl.rc_first_appl = NULL;
3357 		else
3358 			rack->r_ctl.rc_first_appl = tqhash_find(rack->r_ctl.tqh, rsm->r_nseq_appl);
3359 	}
3360 	if (rsm == rack->r_ctl.rc_resend)
3361 		rack->r_ctl.rc_resend = NULL;
3362 	if (rsm == rack->r_ctl.rc_end_appl)
3363 		rack->r_ctl.rc_end_appl = NULL;
3364 	if (rack->r_ctl.rc_tlpsend == rsm)
3365 		rack->r_ctl.rc_tlpsend = NULL;
3366 	if (rack->r_ctl.rc_sacklast == rsm)
3367 		rack->r_ctl.rc_sacklast = NULL;
3368 	memset(rsm, 0, sizeof(struct rack_sendmap));
3369 	/* Make sure we are not going to overrun our count limit of 0xff */
3370 	if ((rack->rc_free_cnt + 1) > RACK_FREE_CNT_MAX) {
3371 		rack_free_trim(rack);
3372 	}
3373 	TAILQ_INSERT_HEAD(&rack->r_ctl.rc_free, rsm, r_tnext);
3374 	rack->rc_free_cnt++;
3375 }
3376 
3377 static uint32_t
3378 rack_get_measure_window(struct tcpcb *tp, struct tcp_rack *rack)
3379 {
3380 	uint64_t srtt, bw, len, tim;
3381 	uint32_t segsiz, def_len, minl;
3382 
3383 	segsiz = min(ctf_fixed_maxseg(tp), rack->r_ctl.rc_pace_min_segs);
3384 	def_len = rack_def_data_window * segsiz;
3385 	if (rack->rc_gp_filled == 0) {
3386 		/*
3387 		 * We have no measurement (IW is in flight?) so
3388 		 * we can only guess using our data_window sysctl
3389 		 * value (usually 20MSS).
3390 		 */
3391 		return (def_len);
3392 	}
3393 	/*
3394 	 * Now we have a number of factors to consider.
3395 	 *
3396 	 * 1) We have a desired BDP which is usually
3397 	 *    at least 2.
3398 	 * 2) We have a minimum number of rtt's usually 1 SRTT
3399 	 *    but we allow it too to be more.
3400 	 * 3) We want to make sure a measurement last N useconds (if
3401 	 *    we have set rack_min_measure_usec.
3402 	 *
3403 	 * We handle the first concern here by trying to create a data
3404 	 * window of max(rack_def_data_window, DesiredBDP). The
3405 	 * second concern we handle in not letting the measurement
3406 	 * window end normally until at least the required SRTT's
3407 	 * have gone by which is done further below in
3408 	 * rack_enough_for_measurement(). Finally the third concern
3409 	 * we also handle here by calculating how long that time
3410 	 * would take at the current BW and then return the
3411 	 * max of our first calculation and that length. Note
3412 	 * that if rack_min_measure_usec is 0, we don't deal
3413 	 * with concern 3. Also for both Concern 1 and 3 an
3414 	 * application limited period could end the measurement
3415 	 * earlier.
3416 	 *
3417 	 * So lets calculate the BDP with the "known" b/w using
3418 	 * the SRTT as our rtt and then multiply it by the goal.
3419 	 */
3420 	bw = rack_get_bw(rack);
3421 	srtt = (uint64_t)tp->t_srtt;
3422 	len = bw * srtt;
3423 	len /= (uint64_t)HPTS_USEC_IN_SEC;
3424 	len *= max(1, rack_goal_bdp);
3425 	/* Now we need to round up to the nearest MSS */
3426 	len = roundup(len, segsiz);
3427 	if (rack_min_measure_usec) {
3428 		/* Now calculate our min length for this b/w */
3429 		tim = rack_min_measure_usec;
3430 		minl = (tim * bw) / (uint64_t)HPTS_USEC_IN_SEC;
3431 		if (minl == 0)
3432 			minl = 1;
3433 		minl = roundup(minl, segsiz);
3434 		if (len < minl)
3435 			len = minl;
3436 	}
3437 	/*
3438 	 * Now if we have a very small window we want
3439 	 * to attempt to get the window that is
3440 	 * as small as possible. This happens on
3441 	 * low b/w connections and we don't want to
3442 	 * span huge numbers of rtt's between measurements.
3443 	 *
3444 	 * We basically include 2 over our "MIN window" so
3445 	 * that the measurement can be shortened (possibly) by
3446 	 * an ack'ed packet.
3447 	 */
3448 	if (len < def_len)
3449 		return (max((uint32_t)len, ((MIN_GP_WIN+2) * segsiz)));
3450 	else
3451 		return (max((uint32_t)len, def_len));
3452 
3453 }
3454 
3455 static int
3456 rack_enough_for_measurement(struct tcpcb *tp, struct tcp_rack *rack, tcp_seq th_ack, uint8_t *quality)
3457 {
3458 	uint32_t tim, srtts, segsiz;
3459 
3460 	/*
3461 	 * Has enough time passed for the GP measurement to be valid?
3462 	 */
3463 	if (SEQ_LT(th_ack, tp->gput_seq)) {
3464 		/* Not enough bytes yet */
3465 		return (0);
3466 	}
3467 	if ((tp->snd_max == tp->snd_una) ||
3468 	    (th_ack == tp->snd_max)){
3469 		/*
3470 		 * All is acked quality of all acked is
3471 		 * usually low or medium, but we in theory could split
3472 		 * all acked into two cases, where you got
3473 		 * a signifigant amount of your window and
3474 		 * where you did not. For now we leave it
3475 		 * but it is something to contemplate in the
3476 		 * future. The danger here is that delayed ack
3477 		 * is effecting the last byte (which is a 50:50 chance).
3478 		 */
3479 		*quality = RACK_QUALITY_ALLACKED;
3480 		return (1);
3481 	}
3482 	if (SEQ_GEQ(th_ack,  tp->gput_ack)) {
3483 		/*
3484 		 * We obtained our entire window of data we wanted
3485 		 * no matter if we are in recovery or not then
3486 		 * its ok since expanding the window does not
3487 		 * make things fuzzy (or at least not as much).
3488 		 */
3489 		*quality = RACK_QUALITY_HIGH;
3490 		return (1);
3491 	}
3492 	segsiz = min(ctf_fixed_maxseg(tp), rack->r_ctl.rc_pace_min_segs);
3493 	if (SEQ_LT(th_ack, tp->gput_ack) &&
3494 	    ((th_ack - tp->gput_seq) < max(rc_init_window(rack), (MIN_GP_WIN * segsiz)))) {
3495 		/* Not enough bytes yet */
3496 		return (0);
3497 	}
3498 	if (rack->r_ctl.rc_first_appl &&
3499 	    (SEQ_GEQ(th_ack, rack->r_ctl.rc_first_appl->r_end))) {
3500 		/*
3501 		 * We are up to the app limited send point
3502 		 * we have to measure irrespective of the time..
3503 		 */
3504 		*quality = RACK_QUALITY_APPLIMITED;
3505 		return (1);
3506 	}
3507 	/* Now what about time? */
3508 	srtts = (rack->r_ctl.rc_gp_srtt * rack_min_srtts);
3509 	tim = tcp_tv_to_usec(&rack->r_ctl.act_rcv_time) - tp->gput_ts;
3510 	if ((tim >= srtts) && (IN_RECOVERY(rack->rc_tp->t_flags) == 0)) {
3511 		/*
3512 		 * We do not allow a measurement if we are in recovery
3513 		 * that would shrink the goodput window we wanted.
3514 		 * This is to prevent cloudyness of when the last send
3515 		 * was actually made.
3516 		 */
3517 		*quality = RACK_QUALITY_HIGH;
3518 		return (1);
3519 	}
3520 	/* Nope not even a full SRTT has passed */
3521 	return (0);
3522 }
3523 
3524 static void
3525 rack_log_timely(struct tcp_rack *rack,
3526 		uint32_t logged, uint64_t cur_bw, uint64_t low_bnd,
3527 		uint64_t up_bnd, int line, uint8_t method)
3528 {
3529 	if (tcp_bblogging_on(rack->rc_tp)) {
3530 		union tcp_log_stackspecific log;
3531 		struct timeval tv;
3532 
3533 		memset(&log, 0, sizeof(log));
3534 		log.u_bbr.flex1 = logged;
3535 		log.u_bbr.flex2 = rack->rc_gp_timely_inc_cnt;
3536 		log.u_bbr.flex2 <<= 4;
3537 		log.u_bbr.flex2 |= rack->rc_gp_timely_dec_cnt;
3538 		log.u_bbr.flex2 <<= 4;
3539 		log.u_bbr.flex2 |= rack->rc_gp_incr;
3540 		log.u_bbr.flex2 <<= 4;
3541 		log.u_bbr.flex2 |= rack->rc_gp_bwred;
3542 		log.u_bbr.flex3 = rack->rc_gp_incr;
3543 		log.u_bbr.flex4 = rack->r_ctl.rack_per_of_gp_ss;
3544 		log.u_bbr.flex5 = rack->r_ctl.rack_per_of_gp_ca;
3545 		log.u_bbr.flex6 = rack->r_ctl.rack_per_of_gp_rec;
3546 		log.u_bbr.flex7 = rack->rc_gp_bwred;
3547 		log.u_bbr.flex8 = method;
3548 		log.u_bbr.cur_del_rate = cur_bw;
3549 		log.u_bbr.delRate = low_bnd;
3550 		log.u_bbr.bw_inuse = up_bnd;
3551 		log.u_bbr.rttProp = rack_get_bw(rack);
3552 		log.u_bbr.pkt_epoch = line;
3553 		log.u_bbr.pkts_out = rack->r_ctl.rc_rtt_diff;
3554 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
3555 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
3556 		log.u_bbr.epoch = rack->r_ctl.rc_gp_srtt;
3557 		log.u_bbr.lt_epoch = rack->r_ctl.rc_prev_gp_srtt;
3558 		log.u_bbr.cwnd_gain = rack->rc_dragged_bottom;
3559 		log.u_bbr.cwnd_gain <<= 1;
3560 		log.u_bbr.cwnd_gain |= rack->rc_gp_saw_rec;
3561 		log.u_bbr.cwnd_gain <<= 1;
3562 		log.u_bbr.cwnd_gain |= rack->rc_gp_saw_ss;
3563 		log.u_bbr.cwnd_gain <<= 1;
3564 		log.u_bbr.cwnd_gain |= rack->rc_gp_saw_ca;
3565 		log.u_bbr.lost = rack->r_ctl.rc_loss_count;
3566 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
3567 		    &rack->rc_inp->inp_socket->so_rcv,
3568 		    &rack->rc_inp->inp_socket->so_snd,
3569 		    TCP_TIMELY_WORK, 0,
3570 		    0, &log, false, &tv);
3571 	}
3572 }
3573 
3574 static int
3575 rack_bw_can_be_raised(struct tcp_rack *rack, uint64_t cur_bw, uint64_t last_bw_est, uint16_t mult)
3576 {
3577 	/*
3578 	 * Before we increase we need to know if
3579 	 * the estimate just made was less than
3580 	 * our pacing goal (i.e. (cur_bw * mult) > last_bw_est)
3581 	 *
3582 	 * If we already are pacing at a fast enough
3583 	 * rate to push us faster there is no sense of
3584 	 * increasing.
3585 	 *
3586 	 * We first caculate our actual pacing rate (ss or ca multiplier
3587 	 * times our cur_bw).
3588 	 *
3589 	 * Then we take the last measured rate and multipy by our
3590 	 * maximum pacing overage to give us a max allowable rate.
3591 	 *
3592 	 * If our act_rate is smaller than our max_allowable rate
3593 	 * then we should increase. Else we should hold steady.
3594 	 *
3595 	 */
3596 	uint64_t act_rate, max_allow_rate;
3597 
3598 	if (rack_timely_no_stopping)
3599 		return (1);
3600 
3601 	if ((cur_bw == 0) || (last_bw_est == 0)) {
3602 		/*
3603 		 * Initial startup case or
3604 		 * everything is acked case.
3605 		 */
3606 		rack_log_timely(rack,  mult, cur_bw, 0, 0,
3607 				__LINE__, 9);
3608 		return (1);
3609 	}
3610 	if (mult <= 100) {
3611 		/*
3612 		 * We can always pace at or slightly above our rate.
3613 		 */
3614 		rack_log_timely(rack,  mult, cur_bw, 0, 0,
3615 				__LINE__, 9);
3616 		return (1);
3617 	}
3618 	act_rate = cur_bw * (uint64_t)mult;
3619 	act_rate /= 100;
3620 	max_allow_rate = last_bw_est * ((uint64_t)rack_max_per_above + (uint64_t)100);
3621 	max_allow_rate /= 100;
3622 	if (act_rate < max_allow_rate) {
3623 		/*
3624 		 * Here the rate we are actually pacing at
3625 		 * is smaller than 10% above our last measurement.
3626 		 * This means we are pacing below what we would
3627 		 * like to try to achieve (plus some wiggle room).
3628 		 */
3629 		rack_log_timely(rack,  mult, cur_bw, act_rate, max_allow_rate,
3630 				__LINE__, 9);
3631 		return (1);
3632 	} else {
3633 		/*
3634 		 * Here we are already pacing at least rack_max_per_above(10%)
3635 		 * what we are getting back. This indicates most likely
3636 		 * that we are being limited (cwnd/rwnd/app) and can't
3637 		 * get any more b/w. There is no sense of trying to
3638 		 * raise up the pacing rate its not speeding us up
3639 		 * and we already are pacing faster than we are getting.
3640 		 */
3641 		rack_log_timely(rack,  mult, cur_bw, act_rate, max_allow_rate,
3642 				__LINE__, 8);
3643 		return (0);
3644 	}
3645 }
3646 
3647 static void
3648 rack_validate_multipliers_at_or_above100(struct tcp_rack *rack)
3649 {
3650 	/*
3651 	 * When we drag bottom, we want to assure
3652 	 * that no multiplier is below 1.0, if so
3653 	 * we want to restore it to at least that.
3654 	 */
3655 	if (rack->r_ctl.rack_per_of_gp_rec  < 100) {
3656 		/* This is unlikely we usually do not touch recovery */
3657 		rack->r_ctl.rack_per_of_gp_rec = 100;
3658 	}
3659 	if (rack->r_ctl.rack_per_of_gp_ca < 100) {
3660 		rack->r_ctl.rack_per_of_gp_ca = 100;
3661 	}
3662 	if (rack->r_ctl.rack_per_of_gp_ss < 100) {
3663 		rack->r_ctl.rack_per_of_gp_ss = 100;
3664 	}
3665 }
3666 
3667 static void
3668 rack_validate_multipliers_at_or_below_100(struct tcp_rack *rack)
3669 {
3670 	if (rack->r_ctl.rack_per_of_gp_ca > 100) {
3671 		rack->r_ctl.rack_per_of_gp_ca = 100;
3672 	}
3673 	if (rack->r_ctl.rack_per_of_gp_ss > 100) {
3674 		rack->r_ctl.rack_per_of_gp_ss = 100;
3675 	}
3676 }
3677 
3678 static void
3679 rack_increase_bw_mul(struct tcp_rack *rack, int timely_says, uint64_t cur_bw, uint64_t last_bw_est, int override)
3680 {
3681 	int32_t  calc, logged, plus;
3682 
3683 	logged = 0;
3684 
3685 	if (rack->rc_skip_timely)
3686 		return;
3687 	if (override) {
3688 		/*
3689 		 * override is passed when we are
3690 		 * loosing b/w and making one last
3691 		 * gasp at trying to not loose out
3692 		 * to a new-reno flow.
3693 		 */
3694 		goto extra_boost;
3695 	}
3696 	/* In classic timely we boost by 5x if we have 5 increases in a row, lets not */
3697 	if (rack->rc_gp_incr &&
3698 	    ((rack->rc_gp_timely_inc_cnt + 1) >= RACK_TIMELY_CNT_BOOST)) {
3699 		/*
3700 		 * Reset and get 5 strokes more before the boost. Note
3701 		 * that the count is 0 based so we have to add one.
3702 		 */
3703 extra_boost:
3704 		plus = (uint32_t)rack_gp_increase_per * RACK_TIMELY_CNT_BOOST;
3705 		rack->rc_gp_timely_inc_cnt = 0;
3706 	} else
3707 		plus = (uint32_t)rack_gp_increase_per;
3708 	/* Must be at least 1% increase for true timely increases */
3709 	if ((plus < 1) &&
3710 	    ((rack->r_ctl.rc_rtt_diff <= 0) || (timely_says <= 0)))
3711 		plus = 1;
3712 	if (rack->rc_gp_saw_rec &&
3713 	    (rack->rc_gp_no_rec_chg == 0) &&
3714 	    rack_bw_can_be_raised(rack, cur_bw, last_bw_est,
3715 				  rack->r_ctl.rack_per_of_gp_rec)) {
3716 		/* We have been in recovery ding it too */
3717 		calc = rack->r_ctl.rack_per_of_gp_rec + plus;
3718 		if (calc > 0xffff)
3719 			calc = 0xffff;
3720 		logged |= 1;
3721 		rack->r_ctl.rack_per_of_gp_rec = (uint16_t)calc;
3722 		if (rack->r_ctl.rack_per_upper_bound_ca &&
3723 		    (rack->rc_dragged_bottom == 0) &&
3724 		    (rack->r_ctl.rack_per_of_gp_rec > rack->r_ctl.rack_per_upper_bound_ca))
3725 			rack->r_ctl.rack_per_of_gp_rec = rack->r_ctl.rack_per_upper_bound_ca;
3726 	}
3727 	if (rack->rc_gp_saw_ca &&
3728 	    (rack->rc_gp_saw_ss == 0) &&
3729 	    rack_bw_can_be_raised(rack, cur_bw, last_bw_est,
3730 				  rack->r_ctl.rack_per_of_gp_ca)) {
3731 		/* In CA */
3732 		calc = rack->r_ctl.rack_per_of_gp_ca + plus;
3733 		if (calc > 0xffff)
3734 			calc = 0xffff;
3735 		logged |= 2;
3736 		rack->r_ctl.rack_per_of_gp_ca = (uint16_t)calc;
3737 		if (rack->r_ctl.rack_per_upper_bound_ca &&
3738 		    (rack->rc_dragged_bottom == 0) &&
3739 		    (rack->r_ctl.rack_per_of_gp_ca > rack->r_ctl.rack_per_upper_bound_ca))
3740 			rack->r_ctl.rack_per_of_gp_ca = rack->r_ctl.rack_per_upper_bound_ca;
3741 	}
3742 	if (rack->rc_gp_saw_ss &&
3743 	    rack_bw_can_be_raised(rack, cur_bw, last_bw_est,
3744 				  rack->r_ctl.rack_per_of_gp_ss)) {
3745 		/* In SS */
3746 		calc = rack->r_ctl.rack_per_of_gp_ss + plus;
3747 		if (calc > 0xffff)
3748 			calc = 0xffff;
3749 		rack->r_ctl.rack_per_of_gp_ss = (uint16_t)calc;
3750 		if (rack->r_ctl.rack_per_upper_bound_ss &&
3751 		    (rack->rc_dragged_bottom == 0) &&
3752 		    (rack->r_ctl.rack_per_of_gp_ss > rack->r_ctl.rack_per_upper_bound_ss))
3753 			rack->r_ctl.rack_per_of_gp_ss = rack->r_ctl.rack_per_upper_bound_ss;
3754 		logged |= 4;
3755 	}
3756 	if (logged &&
3757 	    (rack->rc_gp_incr == 0)){
3758 		/* Go into increment mode */
3759 		rack->rc_gp_incr = 1;
3760 		rack->rc_gp_timely_inc_cnt = 0;
3761 	}
3762 	if (rack->rc_gp_incr &&
3763 	    logged &&
3764 	    (rack->rc_gp_timely_inc_cnt < RACK_TIMELY_CNT_BOOST)) {
3765 		rack->rc_gp_timely_inc_cnt++;
3766 	}
3767 	rack_log_timely(rack,  logged, plus, 0, 0,
3768 			__LINE__, 1);
3769 }
3770 
3771 static uint32_t
3772 rack_get_decrease(struct tcp_rack *rack, uint32_t curper, int32_t rtt_diff)
3773 {
3774 	/*-
3775 	 * norm_grad = rtt_diff / minrtt;
3776 	 * new_per = curper * (1 - B * norm_grad)
3777 	 *
3778 	 * B = rack_gp_decrease_per (default 80%)
3779 	 * rtt_dif = input var current rtt-diff
3780 	 * curper = input var current percentage
3781 	 * minrtt = from rack filter
3782 	 *
3783 	 * In order to do the floating point calculations above we
3784 	 * do an integer conversion. The code looks confusing so let me
3785 	 * translate it into something that use more variables and
3786 	 * is clearer for us humans :)
3787 	 *
3788 	 * uint64_t norm_grad, inverse, reduce_by, final_result;
3789 	 * uint32_t perf;
3790 	 *
3791 	 * norm_grad = (((uint64_t)rtt_diff * 1000000) /
3792 	 *             (uint64_t)get_filter_small(&rack->r_ctl.rc_gp_min_rtt));
3793 	 * inverse = ((uint64_t)rack_gp_decrease * (uint64_t)1000000) * norm_grad;
3794 	 * inverse /= 1000000;
3795 	 * reduce_by = (1000000 - inverse);
3796 	 * final_result = (cur_per * reduce_by) / 1000000;
3797 	 * perf = (uint32_t)final_result;
3798 	 */
3799 	uint64_t perf;
3800 
3801 	perf = (((uint64_t)curper * ((uint64_t)1000000 -
3802 		    ((uint64_t)rack_gp_decrease_per * (uint64_t)10000 *
3803 		     (((uint64_t)rtt_diff * (uint64_t)1000000)/
3804 		      (uint64_t)get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt)))/
3805 		     (uint64_t)1000000)) /
3806 		(uint64_t)1000000);
3807 	if (perf > curper) {
3808 		/* TSNH */
3809 		perf = curper - 1;
3810 	}
3811 	return ((uint32_t)perf);
3812 }
3813 
3814 static uint32_t
3815 rack_decrease_highrtt(struct tcp_rack *rack, uint32_t curper, uint32_t rtt)
3816 {
3817 	/*
3818 	 *                                   highrttthresh
3819 	 * result = curper * (1 - (B * ( 1 -  ------          ))
3820 	 *                                     gp_srtt
3821 	 *
3822 	 * B = rack_gp_decrease_per (default .8 i.e. 80)
3823 	 * highrttthresh = filter_min * rack_gp_rtt_maxmul
3824 	 */
3825 	uint64_t perf;
3826 	uint32_t highrttthresh;
3827 
3828 	highrttthresh = get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt) * rack_gp_rtt_maxmul;
3829 
3830 	perf = (((uint64_t)curper * ((uint64_t)1000000 -
3831 				     ((uint64_t)rack_gp_decrease_per * ((uint64_t)1000000 -
3832 					((uint64_t)highrttthresh * (uint64_t)1000000) /
3833 						    (uint64_t)rtt)) / 100)) /(uint64_t)1000000);
3834 	if (tcp_bblogging_on(rack->rc_tp)) {
3835 		uint64_t log1;
3836 
3837 		log1 = rtt;
3838 		log1 <<= 32;
3839 		log1 |= highrttthresh;
3840 		rack_log_timely(rack,
3841 				rack_gp_decrease_per,
3842 				(uint64_t)curper,
3843 				log1,
3844 				perf,
3845 				__LINE__,
3846 				15);
3847 	}
3848 	return (perf);
3849 }
3850 
3851 static void
3852 rack_decrease_bw_mul(struct tcp_rack *rack, int timely_says, uint32_t rtt, int32_t rtt_diff)
3853 {
3854 	uint64_t logvar, logvar2, logvar3;
3855 	uint32_t logged, new_per, ss_red, ca_red, rec_red, alt, val;
3856 
3857 	if (rack->rc_skip_timely)
3858 		return;
3859 	if (rack->rc_gp_incr) {
3860 		/* Turn off increment counting */
3861 		rack->rc_gp_incr = 0;
3862 		rack->rc_gp_timely_inc_cnt = 0;
3863 	}
3864 	ss_red = ca_red = rec_red = 0;
3865 	logged = 0;
3866 	/* Calculate the reduction value */
3867 	if (rtt_diff < 0) {
3868 		rtt_diff *= -1;
3869 	}
3870 	/* Must be at least 1% reduction */
3871 	if (rack->rc_gp_saw_rec && (rack->rc_gp_no_rec_chg == 0)) {
3872 		/* We have been in recovery ding it too */
3873 		if (timely_says == 2) {
3874 			new_per = rack_decrease_highrtt(rack, rack->r_ctl.rack_per_of_gp_rec, rtt);
3875 			alt = rack_get_decrease(rack, rack->r_ctl.rack_per_of_gp_rec, rtt_diff);
3876 			if (alt < new_per)
3877 				val = alt;
3878 			else
3879 				val = new_per;
3880 		} else
3881 			 val = new_per = alt = rack_get_decrease(rack, rack->r_ctl.rack_per_of_gp_rec, rtt_diff);
3882 		if (rack->r_ctl.rack_per_of_gp_rec > val) {
3883 			rec_red = (rack->r_ctl.rack_per_of_gp_rec - val);
3884 			rack->r_ctl.rack_per_of_gp_rec = (uint16_t)val;
3885 		} else {
3886 			rack->r_ctl.rack_per_of_gp_rec = rack_per_lower_bound;
3887 			rec_red = 0;
3888 		}
3889 		if (rack_per_lower_bound > rack->r_ctl.rack_per_of_gp_rec)
3890 			rack->r_ctl.rack_per_of_gp_rec = rack_per_lower_bound;
3891 		logged |= 1;
3892 	}
3893 	if (rack->rc_gp_saw_ss) {
3894 		/* Sent in SS */
3895 		if (timely_says == 2) {
3896 			new_per = rack_decrease_highrtt(rack, rack->r_ctl.rack_per_of_gp_ss, rtt);
3897 			alt = rack_get_decrease(rack, rack->r_ctl.rack_per_of_gp_ss, rtt_diff);
3898 			if (alt < new_per)
3899 				val = alt;
3900 			else
3901 				val = new_per;
3902 		} else
3903 			val = new_per = alt = rack_get_decrease(rack, rack->r_ctl.rack_per_of_gp_ss, rtt_diff);
3904 		if (rack->r_ctl.rack_per_of_gp_ss > new_per) {
3905 			ss_red = rack->r_ctl.rack_per_of_gp_ss - val;
3906 			rack->r_ctl.rack_per_of_gp_ss = (uint16_t)val;
3907 		} else {
3908 			ss_red = new_per;
3909 			rack->r_ctl.rack_per_of_gp_ss = rack_per_lower_bound;
3910 			logvar = new_per;
3911 			logvar <<= 32;
3912 			logvar |= alt;
3913 			logvar2 = (uint32_t)rtt;
3914 			logvar2 <<= 32;
3915 			logvar2 |= (uint32_t)rtt_diff;
3916 			logvar3 = rack_gp_rtt_maxmul;
3917 			logvar3 <<= 32;
3918 			logvar3 |= get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt);
3919 			rack_log_timely(rack, timely_says,
3920 					logvar2, logvar3,
3921 					logvar, __LINE__, 10);
3922 		}
3923 		if (rack_per_lower_bound > rack->r_ctl.rack_per_of_gp_ss)
3924 			rack->r_ctl.rack_per_of_gp_ss = rack_per_lower_bound;
3925 		logged |= 4;
3926 	} else if (rack->rc_gp_saw_ca) {
3927 		/* Sent in CA */
3928 		if (timely_says == 2) {
3929 			new_per = rack_decrease_highrtt(rack, rack->r_ctl.rack_per_of_gp_ca, rtt);
3930 			alt = rack_get_decrease(rack, rack->r_ctl.rack_per_of_gp_ca, rtt_diff);
3931 			if (alt < new_per)
3932 				val = alt;
3933 			else
3934 				val = new_per;
3935 		} else
3936 			val = new_per = alt = rack_get_decrease(rack, rack->r_ctl.rack_per_of_gp_ca, rtt_diff);
3937 		if (rack->r_ctl.rack_per_of_gp_ca > val) {
3938 			ca_red = rack->r_ctl.rack_per_of_gp_ca - val;
3939 			rack->r_ctl.rack_per_of_gp_ca = (uint16_t)val;
3940 		} else {
3941 			rack->r_ctl.rack_per_of_gp_ca = rack_per_lower_bound;
3942 			ca_red = 0;
3943 			logvar = new_per;
3944 			logvar <<= 32;
3945 			logvar |= alt;
3946 			logvar2 = (uint32_t)rtt;
3947 			logvar2 <<= 32;
3948 			logvar2 |= (uint32_t)rtt_diff;
3949 			logvar3 = rack_gp_rtt_maxmul;
3950 			logvar3 <<= 32;
3951 			logvar3 |= get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt);
3952 			rack_log_timely(rack, timely_says,
3953 					logvar2, logvar3,
3954 					logvar, __LINE__, 10);
3955 		}
3956 		if (rack_per_lower_bound > rack->r_ctl.rack_per_of_gp_ca)
3957 			rack->r_ctl.rack_per_of_gp_ca = rack_per_lower_bound;
3958 		logged |= 2;
3959 	}
3960 	if (rack->rc_gp_timely_dec_cnt < 0x7) {
3961 		rack->rc_gp_timely_dec_cnt++;
3962 		if (rack_timely_dec_clear &&
3963 		    (rack->rc_gp_timely_dec_cnt == rack_timely_dec_clear))
3964 			rack->rc_gp_timely_dec_cnt = 0;
3965 	}
3966 	logvar = ss_red;
3967 	logvar <<= 32;
3968 	logvar |= ca_red;
3969 	rack_log_timely(rack,  logged, rec_red, rack_per_lower_bound, logvar,
3970 			__LINE__, 2);
3971 }
3972 
3973 static void
3974 rack_log_rtt_shrinks(struct tcp_rack *rack, uint32_t us_cts,
3975 		     uint32_t rtt, uint32_t line, uint8_t reas)
3976 {
3977 	if (tcp_bblogging_on(rack->rc_tp)) {
3978 		union tcp_log_stackspecific log;
3979 		struct timeval tv;
3980 
3981 		memset(&log, 0, sizeof(log));
3982 		log.u_bbr.flex1 = line;
3983 		log.u_bbr.flex2 = rack->r_ctl.rc_time_probertt_starts;
3984 		log.u_bbr.flex3 = rack->r_ctl.rc_lower_rtt_us_cts;
3985 		log.u_bbr.flex4 = rack->r_ctl.rack_per_of_gp_ss;
3986 		log.u_bbr.flex5 = rtt;
3987 		log.u_bbr.flex6 = rack->rc_highly_buffered;
3988 		log.u_bbr.flex6 <<= 1;
3989 		log.u_bbr.flex6 |= rack->forced_ack;
3990 		log.u_bbr.flex6 <<= 1;
3991 		log.u_bbr.flex6 |= rack->rc_gp_dyn_mul;
3992 		log.u_bbr.flex6 <<= 1;
3993 		log.u_bbr.flex6 |= rack->in_probe_rtt;
3994 		log.u_bbr.flex6 <<= 1;
3995 		log.u_bbr.flex6 |= rack->measure_saw_probe_rtt;
3996 		log.u_bbr.flex7 = rack->r_ctl.rack_per_of_gp_probertt;
3997 		log.u_bbr.pacing_gain = rack->r_ctl.rack_per_of_gp_ca;
3998 		log.u_bbr.cwnd_gain = rack->r_ctl.rack_per_of_gp_rec;
3999 		log.u_bbr.flex8 = reas;
4000 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
4001 		log.u_bbr.delRate = rack_get_bw(rack);
4002 		log.u_bbr.cur_del_rate = rack->r_ctl.rc_highest_us_rtt;
4003 		log.u_bbr.cur_del_rate <<= 32;
4004 		log.u_bbr.cur_del_rate |= rack->r_ctl.rc_lowest_us_rtt;
4005 		log.u_bbr.applimited = rack->r_ctl.rc_time_probertt_entered;
4006 		log.u_bbr.pkts_out = rack->r_ctl.rc_rtt_diff;
4007 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
4008 		log.u_bbr.epoch = rack->r_ctl.rc_gp_srtt;
4009 		log.u_bbr.lt_epoch = rack->r_ctl.rc_prev_gp_srtt;
4010 		log.u_bbr.pkt_epoch = rack->r_ctl.rc_lower_rtt_us_cts;
4011 		log.u_bbr.delivered = rack->r_ctl.rc_target_probertt_flight;
4012 		log.u_bbr.lost = get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt);
4013 		log.u_bbr.rttProp = us_cts;
4014 		log.u_bbr.rttProp <<= 32;
4015 		log.u_bbr.rttProp |= rack->r_ctl.rc_entry_gp_rtt;
4016 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
4017 		    &rack->rc_inp->inp_socket->so_rcv,
4018 		    &rack->rc_inp->inp_socket->so_snd,
4019 		    BBR_LOG_RTT_SHRINKS, 0,
4020 		    0, &log, false, &rack->r_ctl.act_rcv_time);
4021 	}
4022 }
4023 
4024 static void
4025 rack_set_prtt_target(struct tcp_rack *rack, uint32_t segsiz, uint32_t rtt)
4026 {
4027 	uint64_t bwdp;
4028 
4029 	bwdp = rack_get_bw(rack);
4030 	bwdp *= (uint64_t)rtt;
4031 	bwdp /= (uint64_t)HPTS_USEC_IN_SEC;
4032 	rack->r_ctl.rc_target_probertt_flight = roundup((uint32_t)bwdp, segsiz);
4033 	if (rack->r_ctl.rc_target_probertt_flight < (segsiz * rack_timely_min_segs)) {
4034 		/*
4035 		 * A window protocol must be able to have 4 packets
4036 		 * outstanding as the floor in order to function
4037 		 * (especially considering delayed ack :D).
4038 		 */
4039 		rack->r_ctl.rc_target_probertt_flight = (segsiz * rack_timely_min_segs);
4040 	}
4041 }
4042 
4043 static void
4044 rack_enter_probertt(struct tcp_rack *rack, uint32_t us_cts)
4045 {
4046 	/**
4047 	 * ProbeRTT is a bit different in rack_pacing than in
4048 	 * BBR. It is like BBR in that it uses the lowering of
4049 	 * the RTT as a signal that we saw something new and
4050 	 * counts from there for how long between. But it is
4051 	 * different in that its quite simple. It does not
4052 	 * play with the cwnd and wait until we get down
4053 	 * to N segments outstanding and hold that for
4054 	 * 200ms. Instead it just sets the pacing reduction
4055 	 * rate to a set percentage (70 by default) and hold
4056 	 * that for a number of recent GP Srtt's.
4057 	 */
4058 	uint32_t segsiz;
4059 
4060 	rack->r_ctl.rc_lower_rtt_us_cts = us_cts;
4061 	if (rack->rc_gp_dyn_mul == 0)
4062 		return;
4063 
4064 	if (rack->rc_tp->snd_max == rack->rc_tp->snd_una) {
4065 		/* We are idle */
4066 		return;
4067 	}
4068 	if ((rack->rc_tp->t_flags & TF_GPUTINPROG) &&
4069 	    SEQ_GT(rack->rc_tp->snd_una, rack->rc_tp->gput_seq)) {
4070 		/*
4071 		 * Stop the goodput now, the idea here is
4072 		 * that future measurements with in_probe_rtt
4073 		 * won't register if they are not greater so
4074 		 * we want to get what info (if any) is available
4075 		 * now.
4076 		 */
4077 		rack_do_goodput_measurement(rack->rc_tp, rack,
4078 					    rack->rc_tp->snd_una, __LINE__,
4079 					    RACK_QUALITY_PROBERTT);
4080 	}
4081 	rack->r_ctl.rack_per_of_gp_probertt = rack_per_of_gp_probertt;
4082 	rack->r_ctl.rc_time_probertt_entered = us_cts;
4083 	segsiz = min(ctf_fixed_maxseg(rack->rc_tp),
4084 		     rack->r_ctl.rc_pace_min_segs);
4085 	rack->in_probe_rtt = 1;
4086 	rack->measure_saw_probe_rtt = 1;
4087 	rack->r_ctl.rc_time_probertt_starts = 0;
4088 	rack->r_ctl.rc_entry_gp_rtt = rack->r_ctl.rc_gp_srtt;
4089 	if (rack_probertt_use_min_rtt_entry)
4090 		rack_set_prtt_target(rack, segsiz, get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt));
4091 	else
4092 		rack_set_prtt_target(rack, segsiz, rack->r_ctl.rc_gp_srtt);
4093 	rack_log_rtt_shrinks(rack,  us_cts,  get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt),
4094 			     __LINE__, RACK_RTTS_ENTERPROBE);
4095 }
4096 
4097 static void
4098 rack_exit_probertt(struct tcp_rack *rack, uint32_t us_cts)
4099 {
4100 	struct rack_sendmap *rsm;
4101 	uint32_t segsiz;
4102 
4103 	segsiz = min(ctf_fixed_maxseg(rack->rc_tp),
4104 		     rack->r_ctl.rc_pace_min_segs);
4105 	rack->in_probe_rtt = 0;
4106 	if ((rack->rc_tp->t_flags & TF_GPUTINPROG) &&
4107 	    SEQ_GT(rack->rc_tp->snd_una, rack->rc_tp->gput_seq)) {
4108 		/*
4109 		 * Stop the goodput now, the idea here is
4110 		 * that future measurements with in_probe_rtt
4111 		 * won't register if they are not greater so
4112 		 * we want to get what info (if any) is available
4113 		 * now.
4114 		 */
4115 		rack_do_goodput_measurement(rack->rc_tp, rack,
4116 					    rack->rc_tp->snd_una, __LINE__,
4117 					    RACK_QUALITY_PROBERTT);
4118 	} else if (rack->rc_tp->t_flags & TF_GPUTINPROG) {
4119 		/*
4120 		 * We don't have enough data to make a measurement.
4121 		 * So lets just stop and start here after exiting
4122 		 * probe-rtt. We probably are not interested in
4123 		 * the results anyway.
4124 		 */
4125 		rack->rc_tp->t_flags &= ~TF_GPUTINPROG;
4126 	}
4127 	/*
4128 	 * Measurements through the current snd_max are going
4129 	 * to be limited by the slower pacing rate.
4130 	 *
4131 	 * We need to mark these as app-limited so we
4132 	 * don't collapse the b/w.
4133 	 */
4134 	rsm = tqhash_max(rack->r_ctl.tqh);
4135 	if (rsm && ((rsm->r_flags & RACK_APP_LIMITED) == 0)) {
4136 		if (rack->r_ctl.rc_app_limited_cnt == 0)
4137 			rack->r_ctl.rc_end_appl = rack->r_ctl.rc_first_appl = rsm;
4138 		else {
4139 			/*
4140 			 * Go out to the end app limited and mark
4141 			 * this new one as next and move the end_appl up
4142 			 * to this guy.
4143 			 */
4144 			if (rack->r_ctl.rc_end_appl)
4145 				rack->r_ctl.rc_end_appl->r_nseq_appl = rsm->r_start;
4146 			rack->r_ctl.rc_end_appl = rsm;
4147 		}
4148 		rsm->r_flags |= RACK_APP_LIMITED;
4149 		rack->r_ctl.rc_app_limited_cnt++;
4150 	}
4151 	/*
4152 	 * Now, we need to examine our pacing rate multipliers.
4153 	 * If its under 100%, we need to kick it back up to
4154 	 * 100%. We also don't let it be over our "max" above
4155 	 * the actual rate i.e. 100% + rack_clamp_atexit_prtt.
4156 	 * Note setting clamp_atexit_prtt to 0 has the effect
4157 	 * of setting CA/SS to 100% always at exit (which is
4158 	 * the default behavior).
4159 	 */
4160 	if (rack_probertt_clear_is) {
4161 		rack->rc_gp_incr = 0;
4162 		rack->rc_gp_bwred = 0;
4163 		rack->rc_gp_timely_inc_cnt = 0;
4164 		rack->rc_gp_timely_dec_cnt = 0;
4165 	}
4166 	/* Do we do any clamping at exit? */
4167 	if (rack->rc_highly_buffered && rack_atexit_prtt_hbp) {
4168 		rack->r_ctl.rack_per_of_gp_ca = rack_atexit_prtt_hbp;
4169 		rack->r_ctl.rack_per_of_gp_ss = rack_atexit_prtt_hbp;
4170 	}
4171 	if ((rack->rc_highly_buffered == 0) && rack_atexit_prtt) {
4172 		rack->r_ctl.rack_per_of_gp_ca = rack_atexit_prtt;
4173 		rack->r_ctl.rack_per_of_gp_ss = rack_atexit_prtt;
4174 	}
4175 	/*
4176 	 * Lets set rtt_diff to 0, so that we will get a "boost"
4177 	 * after exiting.
4178 	 */
4179 	rack->r_ctl.rc_rtt_diff = 0;
4180 
4181 	/* Clear all flags so we start fresh */
4182 	rack->rc_tp->t_bytes_acked = 0;
4183 	rack->rc_tp->t_ccv.flags &= ~CCF_ABC_SENTAWND;
4184 	/*
4185 	 * If configured to, set the cwnd and ssthresh to
4186 	 * our targets.
4187 	 */
4188 	if (rack_probe_rtt_sets_cwnd) {
4189 		uint64_t ebdp;
4190 		uint32_t setto;
4191 
4192 		/* Set ssthresh so we get into CA once we hit our target */
4193 		if (rack_probertt_use_min_rtt_exit == 1) {
4194 			/* Set to min rtt */
4195 			rack_set_prtt_target(rack, segsiz,
4196 					     get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt));
4197 		} else if (rack_probertt_use_min_rtt_exit == 2) {
4198 			/* Set to current gp rtt */
4199 			rack_set_prtt_target(rack, segsiz,
4200 					     rack->r_ctl.rc_gp_srtt);
4201 		} else if (rack_probertt_use_min_rtt_exit == 3) {
4202 			/* Set to entry gp rtt */
4203 			rack_set_prtt_target(rack, segsiz,
4204 					     rack->r_ctl.rc_entry_gp_rtt);
4205 		} else {
4206 			uint64_t sum;
4207 			uint32_t setval;
4208 
4209 			sum = rack->r_ctl.rc_entry_gp_rtt;
4210 			sum *= 10;
4211 			sum /= (uint64_t)(max(1, rack->r_ctl.rc_gp_srtt));
4212 			if (sum >= 20) {
4213 				/*
4214 				 * A highly buffered path needs
4215 				 * cwnd space for timely to work.
4216 				 * Lets set things up as if
4217 				 * we are heading back here again.
4218 				 */
4219 				setval = rack->r_ctl.rc_entry_gp_rtt;
4220 			} else if (sum >= 15) {
4221 				/*
4222 				 * Lets take the smaller of the
4223 				 * two since we are just somewhat
4224 				 * buffered.
4225 				 */
4226 				setval = rack->r_ctl.rc_gp_srtt;
4227 				if (setval > rack->r_ctl.rc_entry_gp_rtt)
4228 					setval = rack->r_ctl.rc_entry_gp_rtt;
4229 			} else {
4230 				/*
4231 				 * Here we are not highly buffered
4232 				 * and should pick the min we can to
4233 				 * keep from causing loss.
4234 				 */
4235 				setval = get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt);
4236 			}
4237 			rack_set_prtt_target(rack, segsiz,
4238 					     setval);
4239 		}
4240 		if (rack_probe_rtt_sets_cwnd > 1) {
4241 			/* There is a percentage here to boost */
4242 			ebdp = rack->r_ctl.rc_target_probertt_flight;
4243 			ebdp *= rack_probe_rtt_sets_cwnd;
4244 			ebdp /= 100;
4245 			setto = rack->r_ctl.rc_target_probertt_flight + ebdp;
4246 		} else
4247 			setto = rack->r_ctl.rc_target_probertt_flight;
4248 		rack->rc_tp->snd_cwnd = roundup(setto, segsiz);
4249 		if (rack->rc_tp->snd_cwnd < (segsiz * rack_timely_min_segs)) {
4250 			/* Enforce a min */
4251 			rack->rc_tp->snd_cwnd = segsiz * rack_timely_min_segs;
4252 		}
4253 		/* If we set in the cwnd also set the ssthresh point so we are in CA */
4254 		rack->rc_tp->snd_ssthresh = (rack->rc_tp->snd_cwnd - 1);
4255 	}
4256 	rack_log_rtt_shrinks(rack,  us_cts,
4257 			     get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt),
4258 			     __LINE__, RACK_RTTS_EXITPROBE);
4259 	/* Clear times last so log has all the info */
4260 	rack->r_ctl.rc_probertt_sndmax_atexit = rack->rc_tp->snd_max;
4261 	rack->r_ctl.rc_time_probertt_entered = us_cts;
4262 	rack->r_ctl.rc_time_probertt_starts = rack->r_ctl.rc_lower_rtt_us_cts = us_cts;
4263 	rack->r_ctl.rc_time_of_last_probertt = us_cts;
4264 }
4265 
4266 static void
4267 rack_check_probe_rtt(struct tcp_rack *rack, uint32_t us_cts)
4268 {
4269 	/* Check in on probe-rtt */
4270 
4271 	if (rack->rc_gp_filled == 0) {
4272 		/* We do not do p-rtt unless we have gp measurements */
4273 		return;
4274 	}
4275 	if (rack->in_probe_rtt) {
4276 		uint64_t no_overflow;
4277 		uint32_t endtime, must_stay;
4278 
4279 		if (rack->r_ctl.rc_went_idle_time &&
4280 		    ((us_cts - rack->r_ctl.rc_went_idle_time) > rack_min_probertt_hold)) {
4281 			/*
4282 			 * We went idle during prtt, just exit now.
4283 			 */
4284 			rack_exit_probertt(rack, us_cts);
4285 		} else if (rack_probe_rtt_safety_val &&
4286 		    TSTMP_GT(us_cts, rack->r_ctl.rc_time_probertt_entered) &&
4287 		    ((us_cts - rack->r_ctl.rc_time_probertt_entered) > rack_probe_rtt_safety_val)) {
4288 			/*
4289 			 * Probe RTT safety value triggered!
4290 			 */
4291 			rack_log_rtt_shrinks(rack,  us_cts,
4292 					     get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt),
4293 					     __LINE__, RACK_RTTS_SAFETY);
4294 			rack_exit_probertt(rack, us_cts);
4295 		}
4296 		/* Calculate the max we will wait */
4297 		endtime = rack->r_ctl.rc_time_probertt_entered + (rack->r_ctl.rc_gp_srtt * rack_max_drain_wait);
4298 		if (rack->rc_highly_buffered)
4299 			endtime += (rack->r_ctl.rc_gp_srtt * rack_max_drain_hbp);
4300 		/* Calculate the min we must wait */
4301 		must_stay = rack->r_ctl.rc_time_probertt_entered + (rack->r_ctl.rc_gp_srtt * rack_must_drain);
4302 		if ((ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked) > rack->r_ctl.rc_target_probertt_flight) &&
4303 		    TSTMP_LT(us_cts, endtime)) {
4304 			uint32_t calc;
4305 			/* Do we lower more? */
4306 no_exit:
4307 			if (TSTMP_GT(us_cts, rack->r_ctl.rc_time_probertt_entered))
4308 				calc = us_cts - rack->r_ctl.rc_time_probertt_entered;
4309 			else
4310 				calc = 0;
4311 			calc /= max(rack->r_ctl.rc_gp_srtt, 1);
4312 			if (calc) {
4313 				/* Maybe */
4314 				calc *= rack_per_of_gp_probertt_reduce;
4315 				if (calc > rack_per_of_gp_probertt)
4316 					rack->r_ctl.rack_per_of_gp_probertt = rack_per_of_gp_lowthresh;
4317 				else
4318 					rack->r_ctl.rack_per_of_gp_probertt = rack_per_of_gp_probertt - calc;
4319 				/* Limit it too */
4320 				if (rack->r_ctl.rack_per_of_gp_probertt < rack_per_of_gp_lowthresh)
4321 					rack->r_ctl.rack_per_of_gp_probertt = rack_per_of_gp_lowthresh;
4322 			}
4323 			/* We must reach target or the time set */
4324 			return;
4325 		}
4326 		if (rack->r_ctl.rc_time_probertt_starts == 0) {
4327 			if ((TSTMP_LT(us_cts, must_stay) &&
4328 			     rack->rc_highly_buffered) ||
4329 			     (ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked) >
4330 			      rack->r_ctl.rc_target_probertt_flight)) {
4331 				/* We are not past the must_stay time */
4332 				goto no_exit;
4333 			}
4334 			rack_log_rtt_shrinks(rack,  us_cts,
4335 					     get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt),
4336 					     __LINE__, RACK_RTTS_REACHTARGET);
4337 			rack->r_ctl.rc_time_probertt_starts = us_cts;
4338 			if (rack->r_ctl.rc_time_probertt_starts == 0)
4339 				rack->r_ctl.rc_time_probertt_starts = 1;
4340 			/* Restore back to our rate we want to pace at in prtt */
4341 			rack->r_ctl.rack_per_of_gp_probertt = rack_per_of_gp_probertt;
4342 		}
4343 		/*
4344 		 * Setup our end time, some number of gp_srtts plus 200ms.
4345 		 */
4346 		no_overflow = ((uint64_t)rack->r_ctl.rc_gp_srtt *
4347 			       (uint64_t)rack_probertt_gpsrtt_cnt_mul);
4348 		if (rack_probertt_gpsrtt_cnt_div)
4349 			endtime = (uint32_t)(no_overflow / (uint64_t)rack_probertt_gpsrtt_cnt_div);
4350 		else
4351 			endtime = 0;
4352 		endtime += rack_min_probertt_hold;
4353 		endtime += rack->r_ctl.rc_time_probertt_starts;
4354 		if (TSTMP_GEQ(us_cts,  endtime)) {
4355 			/* yes, exit probertt */
4356 			rack_exit_probertt(rack, us_cts);
4357 		}
4358 
4359 	} else if ((rack->rc_skip_timely == 0) &&
4360 		   (TSTMP_GT(us_cts, rack->r_ctl.rc_lower_rtt_us_cts)) &&
4361 		   ((us_cts - rack->r_ctl.rc_lower_rtt_us_cts) >= rack_time_between_probertt)) {
4362 		/* Go into probertt, its been too long since we went lower */
4363 		rack_enter_probertt(rack, us_cts);
4364 	}
4365 }
4366 
4367 static void
4368 rack_update_multiplier(struct tcp_rack *rack, int32_t timely_says, uint64_t last_bw_est,
4369 		       uint32_t rtt, int32_t rtt_diff)
4370 {
4371 	uint64_t cur_bw, up_bnd, low_bnd, subfr;
4372 	uint32_t losses;
4373 
4374 	if ((rack->rc_gp_dyn_mul == 0) ||
4375 	    (rack->use_fixed_rate) ||
4376 	    (rack->in_probe_rtt) ||
4377 	    (rack->rc_always_pace == 0)) {
4378 		/* No dynamic GP multiplier in play */
4379 		return;
4380 	}
4381 	losses = rack->r_ctl.rc_loss_count - rack->r_ctl.rc_loss_at_start;
4382 	cur_bw = rack_get_bw(rack);
4383 	/* Calculate our up and down range */
4384 	up_bnd = rack->r_ctl.last_gp_comp_bw * (uint64_t)rack_gp_per_bw_mul_up;
4385 	up_bnd /= 100;
4386 	up_bnd += rack->r_ctl.last_gp_comp_bw;
4387 
4388 	subfr = (uint64_t)rack->r_ctl.last_gp_comp_bw * (uint64_t)rack_gp_per_bw_mul_down;
4389 	subfr /= 100;
4390 	low_bnd = rack->r_ctl.last_gp_comp_bw - subfr;
4391 	if ((timely_says == 2) && (rack->r_ctl.rc_no_push_at_mrtt)) {
4392 		/*
4393 		 * This is the case where our RTT is above
4394 		 * the max target and we have been configured
4395 		 * to just do timely no bonus up stuff in that case.
4396 		 *
4397 		 * There are two configurations, set to 1, and we
4398 		 * just do timely if we are over our max. If its
4399 		 * set above 1 then we slam the multipliers down
4400 		 * to 100 and then decrement per timely.
4401 		 */
4402 		rack_log_timely(rack,  timely_says, cur_bw, low_bnd, up_bnd,
4403 				__LINE__, 3);
4404 		if (rack->r_ctl.rc_no_push_at_mrtt > 1)
4405 			rack_validate_multipliers_at_or_below_100(rack);
4406 		rack_decrease_bw_mul(rack, timely_says, rtt, rtt_diff);
4407 	} else if ((timely_says != 0) && (last_bw_est < low_bnd) && !losses) {
4408 		/*
4409 		 * We are decreasing this is a bit complicated this
4410 		 * means we are loosing ground. This could be
4411 		 * because another flow entered and we are competing
4412 		 * for b/w with it. This will push the RTT up which
4413 		 * makes timely unusable unless we want to get shoved
4414 		 * into a corner and just be backed off (the age
4415 		 * old problem with delay based CC).
4416 		 *
4417 		 * On the other hand if it was a route change we
4418 		 * would like to stay somewhat contained and not
4419 		 * blow out the buffers.
4420 		 */
4421 		rack_log_timely(rack,  timely_says, cur_bw, low_bnd, up_bnd,
4422 				__LINE__, 3);
4423 		rack->r_ctl.last_gp_comp_bw = cur_bw;
4424 		if (rack->rc_gp_bwred == 0) {
4425 			/* Go into reduction counting */
4426 			rack->rc_gp_bwred = 1;
4427 			rack->rc_gp_timely_dec_cnt = 0;
4428 		}
4429 		if (rack->rc_gp_timely_dec_cnt < rack_timely_max_push_drop) {
4430 			/*
4431 			 * Push another time with a faster pacing
4432 			 * to try to gain back (we include override to
4433 			 * get a full raise factor).
4434 			 */
4435 			if ((rack->rc_gp_saw_ca && rack->r_ctl.rack_per_of_gp_ca <= rack_down_raise_thresh) ||
4436 			    (rack->rc_gp_saw_ss && rack->r_ctl.rack_per_of_gp_ss <= rack_down_raise_thresh) ||
4437 			    (timely_says == 0) ||
4438 			    (rack_down_raise_thresh == 0)) {
4439 				/*
4440 				 * Do an override up in b/w if we were
4441 				 * below the threshold or if the threshold
4442 				 * is zero we always do the raise.
4443 				 */
4444 				rack_increase_bw_mul(rack, timely_says, cur_bw, last_bw_est, 1);
4445 			} else {
4446 				/* Log it stays the same */
4447 				rack_log_timely(rack,  0, last_bw_est, low_bnd, 0,
4448 						__LINE__, 11);
4449 			}
4450 			rack->rc_gp_timely_dec_cnt++;
4451 			/* We are not incrementing really no-count */
4452 			rack->rc_gp_incr = 0;
4453 			rack->rc_gp_timely_inc_cnt = 0;
4454 		} else {
4455 			/*
4456 			 * Lets just use the RTT
4457 			 * information and give up
4458 			 * pushing.
4459 			 */
4460 			goto use_timely;
4461 		}
4462 	} else if ((timely_says != 2) &&
4463 		    !losses &&
4464 		    (last_bw_est > up_bnd)) {
4465 		/*
4466 		 * We are increasing b/w lets keep going, updating
4467 		 * our b/w and ignoring any timely input, unless
4468 		 * of course we are at our max raise (if there is one).
4469 		 */
4470 
4471 		rack_log_timely(rack,  timely_says, cur_bw, low_bnd, up_bnd,
4472 				__LINE__, 3);
4473 		rack->r_ctl.last_gp_comp_bw = cur_bw;
4474 		if (rack->rc_gp_saw_ss &&
4475 		    rack->r_ctl.rack_per_upper_bound_ss &&
4476 		     (rack->r_ctl.rack_per_of_gp_ss == rack->r_ctl.rack_per_upper_bound_ss)) {
4477 			    /*
4478 			     * In cases where we can't go higher
4479 			     * we should just use timely.
4480 			     */
4481 			    goto use_timely;
4482 		}
4483 		if (rack->rc_gp_saw_ca &&
4484 		    rack->r_ctl.rack_per_upper_bound_ca &&
4485 		    (rack->r_ctl.rack_per_of_gp_ca == rack->r_ctl.rack_per_upper_bound_ca)) {
4486 			    /*
4487 			     * In cases where we can't go higher
4488 			     * we should just use timely.
4489 			     */
4490 			    goto use_timely;
4491 		}
4492 		rack->rc_gp_bwred = 0;
4493 		rack->rc_gp_timely_dec_cnt = 0;
4494 		/* You get a set number of pushes if timely is trying to reduce */
4495 		if ((rack->rc_gp_incr < rack_timely_max_push_rise) || (timely_says == 0)) {
4496 			rack_increase_bw_mul(rack, timely_says, cur_bw, last_bw_est, 0);
4497 		} else {
4498 			/* Log it stays the same */
4499 			rack_log_timely(rack,  0, last_bw_est, up_bnd, 0,
4500 			    __LINE__, 12);
4501 		}
4502 		return;
4503 	} else {
4504 		/*
4505 		 * We are staying between the lower and upper range bounds
4506 		 * so use timely to decide.
4507 		 */
4508 		rack_log_timely(rack,  timely_says, cur_bw, low_bnd, up_bnd,
4509 				__LINE__, 3);
4510 use_timely:
4511 		if (timely_says) {
4512 			rack->rc_gp_incr = 0;
4513 			rack->rc_gp_timely_inc_cnt = 0;
4514 			if ((rack->rc_gp_timely_dec_cnt < rack_timely_max_push_drop) &&
4515 			    !losses &&
4516 			    (last_bw_est < low_bnd)) {
4517 				/* We are loosing ground */
4518 				rack_increase_bw_mul(rack, timely_says, cur_bw, last_bw_est, 0);
4519 				rack->rc_gp_timely_dec_cnt++;
4520 				/* We are not incrementing really no-count */
4521 				rack->rc_gp_incr = 0;
4522 				rack->rc_gp_timely_inc_cnt = 0;
4523 			} else
4524 				rack_decrease_bw_mul(rack, timely_says, rtt, rtt_diff);
4525 		} else {
4526 			rack->rc_gp_bwred = 0;
4527 			rack->rc_gp_timely_dec_cnt = 0;
4528 			rack_increase_bw_mul(rack, timely_says, cur_bw, last_bw_est, 0);
4529 		}
4530 	}
4531 }
4532 
4533 static int32_t
4534 rack_make_timely_judgement(struct tcp_rack *rack, uint32_t rtt, int32_t rtt_diff, uint32_t prev_rtt)
4535 {
4536 	int32_t timely_says;
4537 	uint64_t log_mult, log_rtt_a_diff;
4538 
4539 	log_rtt_a_diff = rtt;
4540 	log_rtt_a_diff <<= 32;
4541 	log_rtt_a_diff |= (uint32_t)rtt_diff;
4542 	if (rtt >= (get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt) *
4543 		    rack_gp_rtt_maxmul)) {
4544 		/* Reduce the b/w multiplier */
4545 		timely_says = 2;
4546 		log_mult = get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt) * rack_gp_rtt_maxmul;
4547 		log_mult <<= 32;
4548 		log_mult |= prev_rtt;
4549 		rack_log_timely(rack,  timely_says, log_mult,
4550 				get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt),
4551 				log_rtt_a_diff, __LINE__, 4);
4552 	} else if (rtt <= (get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt) +
4553 			   ((get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt) * rack_gp_rtt_minmul) /
4554 			    max(rack_gp_rtt_mindiv , 1)))) {
4555 		/* Increase the b/w multiplier */
4556 		log_mult = get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt) +
4557 			((get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt) * rack_gp_rtt_minmul) /
4558 			 max(rack_gp_rtt_mindiv , 1));
4559 		log_mult <<= 32;
4560 		log_mult |= prev_rtt;
4561 		timely_says = 0;
4562 		rack_log_timely(rack,  timely_says, log_mult ,
4563 				get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt),
4564 				log_rtt_a_diff, __LINE__, 5);
4565 	} else {
4566 		/*
4567 		 * Use a gradient to find it the timely gradient
4568 		 * is:
4569 		 * grad = rc_rtt_diff / min_rtt;
4570 		 *
4571 		 * anything below or equal to 0 will be
4572 		 * a increase indication. Anything above
4573 		 * zero is a decrease. Note we take care
4574 		 * of the actual gradient calculation
4575 		 * in the reduction (its not needed for
4576 		 * increase).
4577 		 */
4578 		log_mult = prev_rtt;
4579 		if (rtt_diff <= 0) {
4580 			/*
4581 			 * Rttdiff is less than zero, increase the
4582 			 * b/w multiplier (its 0 or negative)
4583 			 */
4584 			timely_says = 0;
4585 			rack_log_timely(rack,  timely_says, log_mult,
4586 					get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt), log_rtt_a_diff, __LINE__, 6);
4587 		} else {
4588 			/* Reduce the b/w multiplier */
4589 			timely_says = 1;
4590 			rack_log_timely(rack,  timely_says, log_mult,
4591 					get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt), log_rtt_a_diff, __LINE__, 7);
4592 		}
4593 	}
4594 	return (timely_says);
4595 }
4596 
4597 static inline int
4598 rack_in_gp_window(struct tcpcb *tp, struct rack_sendmap *rsm)
4599 {
4600 	if (SEQ_GEQ(rsm->r_start, tp->gput_seq) &&
4601 	    SEQ_LEQ(rsm->r_end, tp->gput_ack)) {
4602 		/**
4603 		 * This covers the case that the
4604 		 * resent is completely inside
4605 		 * the gp range or up to it.
4606 		 *      |----------------|
4607 		 *      |-----| <or>
4608 		 *            |----|
4609 		 *            <or>   |---|
4610 		 */
4611 		return (1);
4612 	} else if (SEQ_LT(rsm->r_start, tp->gput_seq) &&
4613 		   SEQ_GT(rsm->r_end, tp->gput_seq)){
4614 		/**
4615 		 * This covers the case of
4616 		 *      |--------------|
4617 		 *  |-------->|
4618 		 */
4619 		return (1);
4620 	} else if (SEQ_GEQ(rsm->r_start, tp->gput_seq) &&
4621 		   SEQ_LT(rsm->r_start, tp->gput_ack) &&
4622 		   SEQ_GEQ(rsm->r_end, tp->gput_ack)) {
4623 
4624 		/**
4625 		 * This covers the case of
4626 		 *      |--------------|
4627 		 *              |-------->|
4628 		 */
4629 		return (1);
4630 	}
4631 	return (0);
4632 }
4633 
4634 static inline void
4635 rack_mark_in_gp_win(struct tcpcb *tp, struct rack_sendmap *rsm)
4636 {
4637 
4638 	if ((tp->t_flags & TF_GPUTINPROG) == 0)
4639 		return;
4640 	/*
4641 	 * We have a Goodput measurement in progress. Mark
4642 	 * the send if its within the window. If its not
4643 	 * in the window make sure it does not have the mark.
4644 	 */
4645 	if (rack_in_gp_window(tp, rsm))
4646 		rsm->r_flags |= RACK_IN_GP_WIN;
4647 	else
4648 		rsm->r_flags &= ~RACK_IN_GP_WIN;
4649 }
4650 
4651 static inline void
4652 rack_clear_gp_marks(struct tcpcb *tp, struct tcp_rack *rack)
4653 {
4654 	/* A GP measurement is ending, clear all marks on the send map*/
4655 	struct rack_sendmap *rsm = NULL;
4656 
4657 	rsm = tqhash_find(rack->r_ctl.tqh, tp->gput_seq);
4658 	if (rsm == NULL) {
4659 		rsm = tqhash_min(rack->r_ctl.tqh);
4660 	}
4661 	/* Nothing left? */
4662 	while ((rsm != NULL) && (SEQ_GEQ(tp->gput_ack, rsm->r_start))){
4663 		rsm->r_flags &= ~RACK_IN_GP_WIN;
4664 		rsm = tqhash_next(rack->r_ctl.tqh, rsm);
4665 	}
4666 }
4667 
4668 
4669 static inline void
4670 rack_tend_gp_marks(struct tcpcb *tp, struct tcp_rack *rack)
4671 {
4672 	struct rack_sendmap *rsm = NULL;
4673 
4674 	if (tp->snd_una == tp->snd_max) {
4675 		/* Nothing outstanding yet, nothing to do here */
4676 		return;
4677 	}
4678 	if (SEQ_GT(tp->gput_seq, tp->snd_una)) {
4679 		/*
4680 		 * We are measuring ahead of some outstanding
4681 		 * data. We need to walk through up until we get
4682 		 * to gp_seq marking so that no rsm is set incorrectly
4683 		 * with RACK_IN_GP_WIN.
4684 		 */
4685 		rsm = tqhash_min(rack->r_ctl.tqh);
4686 		while (rsm != NULL) {
4687 			rack_mark_in_gp_win(tp, rsm);
4688 			if (SEQ_GEQ(rsm->r_end, tp->gput_seq))
4689 				break;
4690 			rsm = tqhash_next(rack->r_ctl.tqh, rsm);
4691 		}
4692 	}
4693 	if (rsm == NULL) {
4694 		/*
4695 		 * Need to find the GP seq, if rsm is
4696 		 * set we stopped as we hit it.
4697 		 */
4698 		rsm = tqhash_find(rack->r_ctl.tqh, tp->gput_seq);
4699 		if (rsm == NULL)
4700 			return;
4701 		rack_mark_in_gp_win(tp, rsm);
4702 	}
4703 	/*
4704 	 * Now we may need to mark already sent rsm, ahead of
4705 	 * gput_seq in the window since they may have been sent
4706 	 * *before* we started our measurment. The rsm, if non-null
4707 	 * has been marked (note if rsm would have been NULL we would have
4708 	 * returned in the previous block). So we go to the next, and continue
4709 	 * until we run out of entries or we exceed the gp_ack value.
4710 	 */
4711 	rsm = tqhash_next(rack->r_ctl.tqh, rsm);
4712 	while (rsm) {
4713 		rack_mark_in_gp_win(tp, rsm);
4714 		if (SEQ_GT(rsm->r_end, tp->gput_ack))
4715 			break;
4716 		rsm = tqhash_next(rack->r_ctl.tqh, rsm);
4717 	}
4718 }
4719 
4720 static void
4721 rack_log_gp_calc(struct tcp_rack *rack, uint32_t add_part, uint32_t sub_part, uint32_t srtt, uint64_t meas_bw, uint64_t utim, uint8_t meth, uint32_t line)
4722 {
4723 	if (tcp_bblogging_on(rack->rc_tp)) {
4724 		union tcp_log_stackspecific log;
4725 		struct timeval tv;
4726 
4727 		memset(&log, 0, sizeof(log));
4728 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
4729 		log.u_bbr.flex1 = add_part;
4730 		log.u_bbr.flex2 = sub_part;
4731 		log.u_bbr.flex3 = rack_wma_divisor;
4732 		log.u_bbr.flex4 = srtt;
4733 		log.u_bbr.flex7 = (uint16_t)line;
4734 		log.u_bbr.flex8 = meth;
4735 		log.u_bbr.delRate = rack->r_ctl.gp_bw;
4736 		log.u_bbr.cur_del_rate = meas_bw;
4737 		log.u_bbr.rttProp = utim;
4738 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
4739 		    &rack->rc_inp->inp_socket->so_rcv,
4740 		    &rack->rc_inp->inp_socket->so_snd,
4741 		    BBR_LOG_THRESH_CALC, 0,
4742 		    0, &log, false, &rack->r_ctl.act_rcv_time);
4743 	}
4744 }
4745 
4746 static void
4747 rack_do_goodput_measurement(struct tcpcb *tp, struct tcp_rack *rack,
4748 			    tcp_seq th_ack, int line, uint8_t quality)
4749 {
4750 	uint64_t tim, bytes_ps, stim, utim;
4751 	uint32_t segsiz, bytes, reqbytes, us_cts;
4752 	int32_t gput, new_rtt_diff, timely_says;
4753 	uint64_t  resid_bw, subpart = 0, addpart = 0, srtt;
4754 	int did_add = 0;
4755 
4756 	us_cts = tcp_tv_to_usec(&rack->r_ctl.act_rcv_time);
4757 	segsiz = min(ctf_fixed_maxseg(tp), rack->r_ctl.rc_pace_min_segs);
4758 	if (TSTMP_GEQ(us_cts, tp->gput_ts))
4759 		tim = us_cts - tp->gput_ts;
4760 	else
4761 		tim = 0;
4762 	if (rack->r_ctl.rc_gp_cumack_ts > rack->r_ctl.rc_gp_output_ts)
4763 		stim = rack->r_ctl.rc_gp_cumack_ts - rack->r_ctl.rc_gp_output_ts;
4764 	else
4765 		stim = 0;
4766 	/*
4767 	 * Use the larger of the send time or ack time. This prevents us
4768 	 * from being influenced by ack artifacts to come up with too
4769 	 * high of measurement. Note that since we are spanning over many more
4770 	 * bytes in most of our measurements hopefully that is less likely to
4771 	 * occur.
4772 	 */
4773 	if (tim > stim)
4774 		utim = max(tim, 1);
4775 	else
4776 		utim = max(stim, 1);
4777 	reqbytes = min(rc_init_window(rack), (MIN_GP_WIN * segsiz));
4778 	rack_log_gpset(rack, th_ack, us_cts, rack->r_ctl.rc_gp_cumack_ts, __LINE__, 3, NULL);
4779 	if ((tim == 0) && (stim == 0)) {
4780 		/*
4781 		 * Invalid measurement time, maybe
4782 		 * all on one ack/one send?
4783 		 */
4784 		bytes = 0;
4785 		bytes_ps = 0;
4786 		rack_log_pacing_delay_calc(rack, bytes_ps, reqbytes,
4787 					   0, 0, 0, 10, __LINE__, NULL, quality);
4788 		goto skip_measurement;
4789 	}
4790 	if (rack->r_ctl.rc_gp_lowrtt == 0xffffffff) {
4791 		/* We never made a us_rtt measurement? */
4792 		bytes = 0;
4793 		bytes_ps = 0;
4794 		rack_log_pacing_delay_calc(rack, bytes_ps, reqbytes,
4795 					   0, 0, 0, 10, __LINE__, NULL, quality);
4796 		goto skip_measurement;
4797 	}
4798 	/*
4799 	 * Calculate the maximum possible b/w this connection
4800 	 * could have. We base our calculation on the lowest
4801 	 * rtt we have seen during the measurement and the
4802 	 * largest rwnd the client has given us in that time. This
4803 	 * forms a BDP that is the maximum that we could ever
4804 	 * get to the client. Anything larger is not valid.
4805 	 *
4806 	 * I originally had code here that rejected measurements
4807 	 * where the time was less than 1/2 the latest us_rtt.
4808 	 * But after thinking on that I realized its wrong since
4809 	 * say you had a 150Mbps or even 1Gbps link, and you
4810 	 * were a long way away.. example I am in Europe (100ms rtt)
4811 	 * talking to my 1Gbps link in S.C. Now measuring say 150,000
4812 	 * bytes my time would be 1.2ms, and yet my rtt would say
4813 	 * the measurement was invalid the time was < 50ms. The
4814 	 * same thing is true for 150Mb (8ms of time).
4815 	 *
4816 	 * A better way I realized is to look at what the maximum
4817 	 * the connection could possibly do. This is gated on
4818 	 * the lowest RTT we have seen and the highest rwnd.
4819 	 * We should in theory never exceed that, if we are
4820 	 * then something on the path is storing up packets
4821 	 * and then feeding them all at once to our endpoint
4822 	 * messing up our measurement.
4823 	 */
4824 	rack->r_ctl.last_max_bw = rack->r_ctl.rc_gp_high_rwnd;
4825 	rack->r_ctl.last_max_bw *= HPTS_USEC_IN_SEC;
4826 	rack->r_ctl.last_max_bw /= rack->r_ctl.rc_gp_lowrtt;
4827 	if (SEQ_LT(th_ack, tp->gput_seq)) {
4828 		/* No measurement can be made */
4829 		bytes = 0;
4830 		bytes_ps = 0;
4831 		rack_log_pacing_delay_calc(rack, bytes_ps, reqbytes,
4832 					   0, 0, 0, 10, __LINE__, NULL, quality);
4833 		goto skip_measurement;
4834 	} else
4835 		bytes = (th_ack - tp->gput_seq);
4836 	bytes_ps = (uint64_t)bytes;
4837 	/*
4838 	 * Don't measure a b/w for pacing unless we have gotten at least
4839 	 * an initial windows worth of data in this measurement interval.
4840 	 *
4841 	 * Small numbers of bytes get badly influenced by delayed ack and
4842 	 * other artifacts. Note we take the initial window or our
4843 	 * defined minimum GP (defaulting to 10 which hopefully is the
4844 	 * IW).
4845 	 */
4846 	if (rack->rc_gp_filled == 0) {
4847 		/*
4848 		 * The initial estimate is special. We
4849 		 * have blasted out an IW worth of packets
4850 		 * without a real valid ack ts results. We
4851 		 * then setup the app_limited_needs_set flag,
4852 		 * this should get the first ack in (probably 2
4853 		 * MSS worth) to be recorded as the timestamp.
4854 		 * We thus allow a smaller number of bytes i.e.
4855 		 * IW - 2MSS.
4856 		 */
4857 		reqbytes -= (2 * segsiz);
4858 		/* Also lets fill previous for our first measurement to be neutral */
4859 		rack->r_ctl.rc_prev_gp_srtt = rack->r_ctl.rc_gp_srtt;
4860 	}
4861 	if ((bytes_ps < reqbytes) || rack->app_limited_needs_set) {
4862 		rack_log_pacing_delay_calc(rack, bytes_ps, reqbytes,
4863 					   rack->r_ctl.rc_app_limited_cnt,
4864 					   0, 0, 10, __LINE__, NULL, quality);
4865 		goto skip_measurement;
4866 	}
4867 	/*
4868 	 * We now need to calculate the Timely like status so
4869 	 * we can update (possibly) the b/w multipliers.
4870 	 */
4871 	new_rtt_diff = (int32_t)rack->r_ctl.rc_gp_srtt - (int32_t)rack->r_ctl.rc_prev_gp_srtt;
4872 	if (rack->rc_gp_filled == 0) {
4873 		/* No previous reading */
4874 		rack->r_ctl.rc_rtt_diff = new_rtt_diff;
4875 	} else {
4876 		if (rack->measure_saw_probe_rtt == 0) {
4877 			/*
4878 			 * We don't want a probertt to be counted
4879 			 * since it will be negative incorrectly. We
4880 			 * expect to be reducing the RTT when we
4881 			 * pace at a slower rate.
4882 			 */
4883 			rack->r_ctl.rc_rtt_diff -= (rack->r_ctl.rc_rtt_diff / 8);
4884 			rack->r_ctl.rc_rtt_diff += (new_rtt_diff / 8);
4885 		}
4886 	}
4887 	timely_says = rack_make_timely_judgement(rack,
4888 	    rack->r_ctl.rc_gp_srtt,
4889 	    rack->r_ctl.rc_rtt_diff,
4890 	    rack->r_ctl.rc_prev_gp_srtt
4891 	);
4892 	bytes_ps *= HPTS_USEC_IN_SEC;
4893 	bytes_ps /= utim;
4894 	if (bytes_ps > rack->r_ctl.last_max_bw) {
4895 		/*
4896 		 * Something is on path playing
4897 		 * since this b/w is not possible based
4898 		 * on our BDP (highest rwnd and lowest rtt
4899 		 * we saw in the measurement window).
4900 		 *
4901 		 * Another option here would be to
4902 		 * instead skip the measurement.
4903 		 */
4904 		rack_log_pacing_delay_calc(rack, bytes, reqbytes,
4905 					   bytes_ps, rack->r_ctl.last_max_bw, 0,
4906 					   11, __LINE__, NULL, quality);
4907 		bytes_ps = rack->r_ctl.last_max_bw;
4908 	}
4909 	/* We store gp for b/w in bytes per second */
4910 	if (rack->rc_gp_filled == 0) {
4911 		/* Initial measurement */
4912 		if (bytes_ps) {
4913 			rack->r_ctl.gp_bw = bytes_ps;
4914 			rack->rc_gp_filled = 1;
4915 			rack->r_ctl.num_measurements = 1;
4916 			rack_set_pace_segments(rack->rc_tp, rack, __LINE__, NULL);
4917 		} else {
4918 			rack_log_pacing_delay_calc(rack, bytes_ps, reqbytes,
4919 						   rack->r_ctl.rc_app_limited_cnt,
4920 						   0, 0, 10, __LINE__, NULL, quality);
4921 		}
4922 		if (tcp_in_hpts(rack->rc_tp) &&
4923 		    (rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT)) {
4924 			/*
4925 			 * Ok we can't trust the pacer in this case
4926 			 * where we transition from un-paced to paced.
4927 			 * Or for that matter when the burst mitigation
4928 			 * was making a wild guess and got it wrong.
4929 			 * Stop the pacer and clear up all the aggregate
4930 			 * delays etc.
4931 			 */
4932 			tcp_hpts_remove(rack->rc_tp);
4933 			rack->r_ctl.rc_hpts_flags = 0;
4934 			rack->r_ctl.rc_last_output_to = 0;
4935 		}
4936 		did_add = 2;
4937 	} else if (rack->r_ctl.num_measurements < RACK_REQ_AVG) {
4938 		/* Still a small number run an average */
4939 		rack->r_ctl.gp_bw += bytes_ps;
4940 		addpart = rack->r_ctl.num_measurements;
4941 		rack->r_ctl.num_measurements++;
4942 		if (rack->r_ctl.num_measurements >= RACK_REQ_AVG) {
4943 			/* We have collected enough to move forward */
4944 			rack->r_ctl.gp_bw /= (uint64_t)rack->r_ctl.num_measurements;
4945 		}
4946 		rack_set_pace_segments(tp, rack, __LINE__, NULL);
4947 		did_add = 3;
4948 	} else {
4949 		/*
4950 		 * We want to take 1/wma of the goodput and add in to 7/8th
4951 		 * of the old value weighted by the srtt. So if your measurement
4952 		 * period is say 2 SRTT's long you would get 1/4 as the
4953 		 * value, if it was like 1/2 SRTT then you would get 1/16th.
4954 		 *
4955 		 * But we must be careful not to take too much i.e. if the
4956 		 * srtt is say 20ms and the measurement is taken over
4957 		 * 400ms our weight would be 400/20 i.e. 20. On the
4958 		 * other hand if we get a measurement over 1ms with a
4959 		 * 10ms rtt we only want to take a much smaller portion.
4960 		 */
4961 		uint8_t meth;
4962 
4963 		if (rack->r_ctl.num_measurements < 0xff) {
4964 			rack->r_ctl.num_measurements++;
4965 		}
4966 		srtt = (uint64_t)tp->t_srtt;
4967 		if (srtt == 0) {
4968 			/*
4969 			 * Strange why did t_srtt go back to zero?
4970 			 */
4971 			if (rack->r_ctl.rc_rack_min_rtt)
4972 				srtt = rack->r_ctl.rc_rack_min_rtt;
4973 			else
4974 				srtt = HPTS_USEC_IN_MSEC;
4975 		}
4976 		/*
4977 		 * XXXrrs: Note for reviewers, in playing with
4978 		 * dynamic pacing I discovered this GP calculation
4979 		 * as done originally leads to some undesired results.
4980 		 * Basically you can get longer measurements contributing
4981 		 * too much to the WMA. Thus I changed it if you are doing
4982 		 * dynamic adjustments to only do the aportioned adjustment
4983 		 * if we have a very small (time wise) measurement. Longer
4984 		 * measurements just get there weight (defaulting to 1/8)
4985 		 * add to the WMA. We may want to think about changing
4986 		 * this to always do that for both sides i.e. dynamic
4987 		 * and non-dynamic... but considering lots of folks
4988 		 * were playing with this I did not want to change the
4989 		 * calculation per.se. without your thoughts.. Lawerence?
4990 		 * Peter??
4991 		 */
4992 		if (rack->rc_gp_dyn_mul == 0) {
4993 			subpart = rack->r_ctl.gp_bw * utim;
4994 			subpart /= (srtt * 8);
4995 			if (subpart < (rack->r_ctl.gp_bw / 2)) {
4996 				/*
4997 				 * The b/w update takes no more
4998 				 * away then 1/2 our running total
4999 				 * so factor it in.
5000 				 */
5001 				addpart = bytes_ps * utim;
5002 				addpart /= (srtt * 8);
5003 				meth = 1;
5004 			} else {
5005 				/*
5006 				 * Don't allow a single measurement
5007 				 * to account for more than 1/2 of the
5008 				 * WMA. This could happen on a retransmission
5009 				 * where utim becomes huge compared to
5010 				 * srtt (multiple retransmissions when using
5011 				 * the sending rate which factors in all the
5012 				 * transmissions from the first one).
5013 				 */
5014 				subpart = rack->r_ctl.gp_bw / 2;
5015 				addpart = bytes_ps / 2;
5016 				meth = 2;
5017 			}
5018 			rack_log_gp_calc(rack, addpart, subpart, srtt, bytes_ps, utim, meth, __LINE__);
5019 			resid_bw = rack->r_ctl.gp_bw - subpart;
5020 			rack->r_ctl.gp_bw = resid_bw + addpart;
5021 			did_add = 1;
5022 		} else {
5023 			if ((utim / srtt) <= 1) {
5024 				/*
5025 				 * The b/w update was over a small period
5026 				 * of time. The idea here is to prevent a small
5027 				 * measurement time period from counting
5028 				 * too much. So we scale it based on the
5029 				 * time so it attributes less than 1/rack_wma_divisor
5030 				 * of its measurement.
5031 				 */
5032 				subpart = rack->r_ctl.gp_bw * utim;
5033 				subpart /= (srtt * rack_wma_divisor);
5034 				addpart = bytes_ps * utim;
5035 				addpart /= (srtt * rack_wma_divisor);
5036 				meth = 3;
5037 			} else {
5038 				/*
5039 				 * The scaled measurement was long
5040 				 * enough so lets just add in the
5041 				 * portion of the measurement i.e. 1/rack_wma_divisor
5042 				 */
5043 				subpart = rack->r_ctl.gp_bw / rack_wma_divisor;
5044 				addpart = bytes_ps / rack_wma_divisor;
5045 				meth = 4;
5046 			}
5047 			if ((rack->measure_saw_probe_rtt == 0) ||
5048 		            (bytes_ps > rack->r_ctl.gp_bw)) {
5049 				/*
5050 				 * For probe-rtt we only add it in
5051 				 * if its larger, all others we just
5052 				 * add in.
5053 				 */
5054 				did_add = 1;
5055 				rack_log_gp_calc(rack, addpart, subpart, srtt, bytes_ps, utim, meth, __LINE__);
5056 				resid_bw = rack->r_ctl.gp_bw - subpart;
5057 				rack->r_ctl.gp_bw = resid_bw + addpart;
5058 			}
5059 		}
5060 		rack_set_pace_segments(tp, rack, __LINE__, NULL);
5061 	}
5062 	/*
5063 	 * We only watch the growth of the GP during the initial startup
5064 	 * or first-slowstart that ensues. If we ever needed to watch
5065 	 * growth of gp outside of that period all we need to do is
5066 	 * remove the first clause of this if (rc_initial_ss_comp).
5067 	 */
5068 	if ((rack->rc_initial_ss_comp == 0) &&
5069 	    (rack->r_ctl.num_measurements >= RACK_REQ_AVG)) {
5070 		uint64_t gp_est;
5071 
5072 		gp_est = bytes_ps;
5073 		if (tcp_bblogging_on(rack->rc_tp)) {
5074 			union tcp_log_stackspecific log;
5075 			struct timeval tv;
5076 
5077 			memset(&log, 0, sizeof(log));
5078 			log.u_bbr.timeStamp = tcp_get_usecs(&tv);
5079 			log.u_bbr.flex1 = rack->r_ctl.current_round;
5080 			log.u_bbr.flex2 = rack->r_ctl.last_rnd_of_gp_rise;
5081 			log.u_bbr.delRate = gp_est;
5082 			log.u_bbr.cur_del_rate = rack->r_ctl.last_gpest;
5083 			log.u_bbr.flex8 = 41;
5084 			(void)tcp_log_event(tp, NULL, NULL, NULL, BBR_LOG_CWND, 0,
5085 					    0, &log, false, NULL, __func__, __LINE__,&tv);
5086 		}
5087 		if ((rack->r_ctl.num_measurements == RACK_REQ_AVG) ||
5088 		    (rack->r_ctl.last_gpest == 0)) {
5089 			/*
5090 			 * The round we get our measurement averaging going
5091 			 * is the base round so it always is the source point
5092 			 * for when we had our first increment. From there on
5093 			 * we only record the round that had a rise.
5094 			 */
5095 			rack->r_ctl.last_rnd_of_gp_rise = rack->r_ctl.current_round;
5096 			rack->r_ctl.last_gpest = rack->r_ctl.gp_bw;
5097 		} else if (gp_est >= rack->r_ctl.last_gpest) {
5098 			/*
5099 			 * Test to see if its gone up enough
5100 			 * to set the round count up to now. Note
5101 			 * that on the seeding of the 4th measurement we
5102 			 */
5103 			gp_est *= 1000;
5104 			gp_est /= rack->r_ctl.last_gpest;
5105 			if ((uint32_t)gp_est > rack->r_ctl.gp_gain_req) {
5106 				/*
5107 				 * We went up enough to record the round.
5108 				 */
5109 				if (tcp_bblogging_on(rack->rc_tp)) {
5110 					union tcp_log_stackspecific log;
5111 					struct timeval tv;
5112 
5113 					memset(&log, 0, sizeof(log));
5114 					log.u_bbr.timeStamp = tcp_get_usecs(&tv);
5115 					log.u_bbr.flex1 = rack->r_ctl.current_round;
5116 					log.u_bbr.flex2 = (uint32_t)gp_est;
5117 					log.u_bbr.flex3 = rack->r_ctl.gp_gain_req;
5118 					log.u_bbr.delRate = gp_est;
5119 					log.u_bbr.cur_del_rate = rack->r_ctl.last_gpest;
5120 					log.u_bbr.flex8 = 42;
5121 					(void)tcp_log_event(tp, NULL, NULL, NULL, BBR_LOG_CWND, 0,
5122 							    0, &log, false, NULL, __func__, __LINE__,&tv);
5123 				}
5124 				rack->r_ctl.last_rnd_of_gp_rise = rack->r_ctl.current_round;
5125 				if (rack->r_ctl.use_gp_not_last == 1)
5126 					rack->r_ctl.last_gpest = rack->r_ctl.gp_bw;
5127 				else
5128 					rack->r_ctl.last_gpest = bytes_ps;
5129 			}
5130 		}
5131 	}
5132 	if ((rack->gp_ready == 0) &&
5133 	    (rack->r_ctl.num_measurements >= rack->r_ctl.req_measurements)) {
5134 		/* We have enough measurements now */
5135 		rack->gp_ready = 1;
5136 		if (rack->dgp_on ||
5137 		    rack->rack_hibeta)
5138 			rack_set_cc_pacing(rack);
5139 		if (rack->defer_options)
5140 			rack_apply_deferred_options(rack);
5141 	}
5142 	rack_log_pacing_delay_calc(rack, subpart, addpart, bytes_ps, stim,
5143 				   rack_get_bw(rack), 22, did_add, NULL, quality);
5144 	/* We do not update any multipliers if we are in or have seen a probe-rtt */
5145 
5146 	if ((rack->measure_saw_probe_rtt == 0) &&
5147 	    rack->rc_gp_rtt_set) {
5148 		if (rack->rc_skip_timely == 0) {
5149 			rack_update_multiplier(rack, timely_says, bytes_ps,
5150 					       rack->r_ctl.rc_gp_srtt,
5151 					       rack->r_ctl.rc_rtt_diff);
5152 		}
5153 	}
5154 	rack_log_pacing_delay_calc(rack, bytes, tim, bytes_ps, stim,
5155 				   rack_get_bw(rack), 3, line, NULL, quality);
5156 	rack_log_pacing_delay_calc(rack,
5157 				   bytes, /* flex2 */
5158 				   tim, /* flex1 */
5159 				   bytes_ps, /* bw_inuse */
5160 				   rack->r_ctl.gp_bw, /* delRate */
5161 				   rack_get_lt_bw(rack), /* rttProp */
5162 				   20, line, NULL, 0);
5163 	/* reset the gp srtt and setup the new prev */
5164 	rack->r_ctl.rc_prev_gp_srtt = rack->r_ctl.rc_gp_srtt;
5165 	/* Record the lost count for the next measurement */
5166 	rack->r_ctl.rc_loss_at_start = rack->r_ctl.rc_loss_count;
5167 skip_measurement:
5168 	/*
5169 	 * We restart our diffs based on the gpsrtt in the
5170 	 * measurement window.
5171 	 */
5172 	rack->rc_gp_rtt_set = 0;
5173 	rack->rc_gp_saw_rec = 0;
5174 	rack->rc_gp_saw_ca = 0;
5175 	rack->rc_gp_saw_ss = 0;
5176 	rack->rc_dragged_bottom = 0;
5177 	if (quality == RACK_QUALITY_HIGH) {
5178 		/*
5179 		 * Gput in the stats world is in kbps where bytes_ps is
5180 		 * bytes per second so we do ((x * 8)/ 1000).
5181 		 */
5182 		gput = (int32_t)((bytes_ps << 3) / (uint64_t)1000);
5183 #ifdef STATS
5184 		stats_voi_update_abs_u32(tp->t_stats, VOI_TCP_GPUT,
5185 					 gput);
5186 		/*
5187 		 * XXXLAS: This is a temporary hack, and should be
5188 		 * chained off VOI_TCP_GPUT when stats(9) grows an
5189 		 * API to deal with chained VOIs.
5190 		 */
5191 		if (tp->t_stats_gput_prev > 0)
5192 			stats_voi_update_abs_s32(tp->t_stats,
5193 						 VOI_TCP_GPUT_ND,
5194 						 ((gput - tp->t_stats_gput_prev) * 100) /
5195 						 tp->t_stats_gput_prev);
5196 #endif
5197 		tp->t_stats_gput_prev = gput;
5198 	}
5199 	tp->t_flags &= ~TF_GPUTINPROG;
5200 	/*
5201 	 * Now are we app limited now and there is space from where we
5202 	 * were to where we want to go?
5203 	 *
5204 	 * We don't do the other case i.e. non-applimited here since
5205 	 * the next send will trigger us picking up the missing data.
5206 	 */
5207 	if (rack->r_ctl.rc_first_appl &&
5208 	    TCPS_HAVEESTABLISHED(tp->t_state) &&
5209 	    rack->r_ctl.rc_app_limited_cnt &&
5210 	    (SEQ_GT(rack->r_ctl.rc_first_appl->r_start, th_ack)) &&
5211 	    ((rack->r_ctl.rc_first_appl->r_end - th_ack) >
5212 	     max(rc_init_window(rack), (MIN_GP_WIN * segsiz)))) {
5213 		/*
5214 		 * Yep there is enough outstanding to make a measurement here.
5215 		 */
5216 		struct rack_sendmap *rsm;
5217 
5218 		rack->r_ctl.rc_gp_lowrtt = 0xffffffff;
5219 		rack->r_ctl.rc_gp_high_rwnd = rack->rc_tp->snd_wnd;
5220 		tp->gput_ts = tcp_tv_to_usec(&rack->r_ctl.act_rcv_time);
5221 		rack->app_limited_needs_set = 0;
5222 		tp->gput_seq = th_ack;
5223 		if (rack->in_probe_rtt)
5224 			rack->measure_saw_probe_rtt = 1;
5225 		else if ((rack->measure_saw_probe_rtt) &&
5226 			 (SEQ_GEQ(tp->gput_seq, rack->r_ctl.rc_probertt_sndmax_atexit)))
5227 			rack->measure_saw_probe_rtt = 0;
5228 		if ((rack->r_ctl.rc_first_appl->r_end - th_ack) >= rack_get_measure_window(tp, rack)) {
5229 			/* There is a full window to gain info from */
5230 			tp->gput_ack = tp->gput_seq + rack_get_measure_window(tp, rack);
5231 		} else {
5232 			/* We can only measure up to the applimited point */
5233 			tp->gput_ack = tp->gput_seq + (rack->r_ctl.rc_first_appl->r_end - th_ack);
5234 			if ((tp->gput_ack - tp->gput_seq) < (MIN_GP_WIN * segsiz)) {
5235 				/*
5236 				 * We don't have enough to make a measurement.
5237 				 */
5238 				tp->t_flags &= ~TF_GPUTINPROG;
5239 				rack_log_pacing_delay_calc(rack, tp->gput_ack, tp->gput_seq,
5240 							   0, 0, 0, 6, __LINE__, NULL, quality);
5241 				return;
5242 			}
5243 		}
5244 		if (tp->t_state >= TCPS_FIN_WAIT_1) {
5245 			/*
5246 			 * We will get no more data into the SB
5247 			 * this means we need to have the data available
5248 			 * before we start a measurement.
5249 			 */
5250 			if (sbavail(&tptosocket(tp)->so_snd) < (tp->gput_ack - tp->gput_seq)) {
5251 				/* Nope not enough data. */
5252 				return;
5253 			}
5254 		}
5255 		tp->t_flags |= TF_GPUTINPROG;
5256 		/*
5257 		 * Now we need to find the timestamp of the send at tp->gput_seq
5258 		 * for the send based measurement.
5259 		 */
5260 		rack->r_ctl.rc_gp_cumack_ts = 0;
5261 		rsm = tqhash_find(rack->r_ctl.tqh, tp->gput_seq);
5262 		if (rsm) {
5263 			/* Ok send-based limit is set */
5264 			if (SEQ_LT(rsm->r_start, tp->gput_seq)) {
5265 				/*
5266 				 * Move back to include the earlier part
5267 				 * so our ack time lines up right (this may
5268 				 * make an overlapping measurement but thats
5269 				 * ok).
5270 				 */
5271 				tp->gput_seq = rsm->r_start;
5272 			}
5273 			if (rsm->r_flags & RACK_ACKED) {
5274 				struct rack_sendmap *nrsm;
5275 
5276 				tp->gput_ts = (uint32_t)rsm->r_ack_arrival;
5277 				tp->gput_seq = rsm->r_end;
5278 				nrsm = tqhash_next(rack->r_ctl.tqh, rsm);
5279 				if (nrsm)
5280 					rsm = nrsm;
5281 				else {
5282 					rack->app_limited_needs_set = 1;
5283 				}
5284 			} else
5285 				rack->app_limited_needs_set = 1;
5286 			/* We always go from the first send */
5287 			rack->r_ctl.rc_gp_output_ts = rsm->r_tim_lastsent[0];
5288 		} else {
5289 			/*
5290 			 * If we don't find the rsm due to some
5291 			 * send-limit set the current time, which
5292 			 * basically disables the send-limit.
5293 			 */
5294 			struct timeval tv;
5295 
5296 			microuptime(&tv);
5297 			rack->r_ctl.rc_gp_output_ts = rack_to_usec_ts(&tv);
5298 		}
5299 		rack_tend_gp_marks(tp, rack);
5300 		rack_log_pacing_delay_calc(rack,
5301 					   tp->gput_seq,
5302 					   tp->gput_ack,
5303 					   (uintptr_t)rsm,
5304 					   tp->gput_ts,
5305 					   (((uint64_t)rack->r_ctl.rc_app_limited_cnt << 32) | (uint64_t)rack->r_ctl.rc_gp_output_ts),
5306 					   9,
5307 					   __LINE__, rsm, quality);
5308 		rack_log_gpset(rack, tp->gput_ack, 0, 0, __LINE__, 1, NULL);
5309 	} else {
5310 		/*
5311 		 * To make sure proper timestamp merging occurs, we need to clear
5312 		 * all GP marks if we don't start a measurement.
5313 		 */
5314 		rack_clear_gp_marks(tp, rack);
5315 	}
5316 }
5317 
5318 /*
5319  * CC wrapper hook functions
5320  */
5321 static void
5322 rack_ack_received(struct tcpcb *tp, struct tcp_rack *rack, uint32_t th_ack, uint16_t nsegs,
5323     uint16_t type, int32_t post_recovery)
5324 {
5325 	uint32_t prior_cwnd, acked;
5326 	struct tcp_log_buffer *lgb = NULL;
5327 	uint8_t labc_to_use, quality;
5328 
5329 	INP_WLOCK_ASSERT(tptoinpcb(tp));
5330 	tp->t_ccv.nsegs = nsegs;
5331 	acked = tp->t_ccv.bytes_this_ack = (th_ack - tp->snd_una);
5332 	if ((post_recovery) && (rack->r_ctl.rc_early_recovery_segs)) {
5333 		uint32_t max;
5334 
5335 		max = rack->r_ctl.rc_early_recovery_segs * ctf_fixed_maxseg(tp);
5336 		if (tp->t_ccv.bytes_this_ack > max) {
5337 			tp->t_ccv.bytes_this_ack = max;
5338 		}
5339 	}
5340 #ifdef STATS
5341 	stats_voi_update_abs_s32(tp->t_stats, VOI_TCP_CALCFRWINDIFF,
5342 	    ((int32_t)rack->r_ctl.cwnd_to_use) - tp->snd_wnd);
5343 #endif
5344 	if ((th_ack == tp->snd_max) && rack->lt_bw_up) {
5345 		/*
5346 		 * We will ack all the data, time to end any
5347 		 * lt_bw_up we have running until something
5348 		 * new is sent. Note we need to use the actual
5349 		 * ack_rcv_time which with pacing may be different.
5350 		 */
5351 		uint64_t tmark;
5352 
5353 		rack->r_ctl.lt_bw_bytes += (tp->snd_max - rack->r_ctl.lt_seq);
5354 		rack->r_ctl.lt_seq = tp->snd_max;
5355 		tmark = tcp_tv_to_lusec(&rack->r_ctl.act_rcv_time);
5356 		if (tmark >= rack->r_ctl.lt_timemark) {
5357 			rack->r_ctl.lt_bw_time += (tmark - rack->r_ctl.lt_timemark);
5358 		}
5359 		rack->r_ctl.lt_timemark = tmark;
5360 		rack->lt_bw_up = 0;
5361 	}
5362 	quality = RACK_QUALITY_NONE;
5363 	if ((tp->t_flags & TF_GPUTINPROG) &&
5364 	    rack_enough_for_measurement(tp, rack, th_ack, &quality)) {
5365 		/* Measure the Goodput */
5366 		rack_do_goodput_measurement(tp, rack, th_ack, __LINE__, quality);
5367 	}
5368 	/* Which way our we limited, if not cwnd limited no advance in CA */
5369 	if (tp->snd_cwnd <= tp->snd_wnd)
5370 		tp->t_ccv.flags |= CCF_CWND_LIMITED;
5371 	else
5372 		tp->t_ccv.flags &= ~CCF_CWND_LIMITED;
5373 	if (tp->snd_cwnd > tp->snd_ssthresh) {
5374 		tp->t_bytes_acked += min(tp->t_ccv.bytes_this_ack,
5375 			 nsegs * V_tcp_abc_l_var * ctf_fixed_maxseg(tp));
5376 		/* For the setting of a window past use the actual scwnd we are using */
5377 		if (tp->t_bytes_acked >= rack->r_ctl.cwnd_to_use) {
5378 			tp->t_bytes_acked -= rack->r_ctl.cwnd_to_use;
5379 			tp->t_ccv.flags |= CCF_ABC_SENTAWND;
5380 		}
5381 	} else {
5382 		tp->t_ccv.flags &= ~CCF_ABC_SENTAWND;
5383 		tp->t_bytes_acked = 0;
5384 	}
5385 	prior_cwnd = tp->snd_cwnd;
5386 	if ((post_recovery == 0) || (rack_max_abc_post_recovery == 0) || rack->r_use_labc_for_rec ||
5387 	    (rack_client_low_buf && rack->client_bufferlvl &&
5388 	    (rack->client_bufferlvl < rack_client_low_buf)))
5389 		labc_to_use = rack->rc_labc;
5390 	else
5391 		labc_to_use = rack_max_abc_post_recovery;
5392 	if (rack_verbose_logging && tcp_bblogging_on(rack->rc_tp)) {
5393 		union tcp_log_stackspecific log;
5394 		struct timeval tv;
5395 
5396 		memset(&log, 0, sizeof(log));
5397 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
5398 		log.u_bbr.flex1 = th_ack;
5399 		log.u_bbr.flex2 = tp->t_ccv.flags;
5400 		log.u_bbr.flex3 = tp->t_ccv.bytes_this_ack;
5401 		log.u_bbr.flex4 = tp->t_ccv.nsegs;
5402 		log.u_bbr.flex5 = labc_to_use;
5403 		log.u_bbr.flex6 = prior_cwnd;
5404 		log.u_bbr.flex7 = 1;  /* always doing RFC6675 SACK */
5405 		log.u_bbr.flex8 = 1;
5406 		lgb = tcp_log_event(tp, NULL, NULL, NULL, BBR_LOG_CWND, 0,
5407 				     0, &log, false, NULL, __func__, __LINE__,&tv);
5408 	}
5409 	if (CC_ALGO(tp)->ack_received != NULL) {
5410 		/* XXXLAS: Find a way to live without this */
5411 		tp->t_ccv.curack = th_ack;
5412 		tp->t_ccv.labc = labc_to_use;
5413 		tp->t_ccv.flags |= CCF_USE_LOCAL_ABC;
5414 		CC_ALGO(tp)->ack_received(&tp->t_ccv, type);
5415 	}
5416 	if (lgb) {
5417 		lgb->tlb_stackinfo.u_bbr.flex6 = tp->snd_cwnd;
5418 	}
5419 	if (rack->r_must_retran) {
5420 		if (SEQ_GEQ(th_ack, rack->r_ctl.rc_snd_max_at_rto)) {
5421 			/*
5422 			 * We now are beyond the rxt point so lets disable
5423 			 * the flag.
5424 			 */
5425 			rack->r_ctl.rc_out_at_rto = 0;
5426 			rack->r_must_retran = 0;
5427 		} else if ((prior_cwnd + ctf_fixed_maxseg(tp)) <= tp->snd_cwnd) {
5428 			/*
5429 			 * Only decrement the rc_out_at_rto if the cwnd advances
5430 			 * at least a whole segment. Otherwise next time the peer
5431 			 * acks, we won't be able to send this generaly happens
5432 			 * when we are in Congestion Avoidance.
5433 			 */
5434 			if (acked <= rack->r_ctl.rc_out_at_rto){
5435 				rack->r_ctl.rc_out_at_rto -= acked;
5436 			} else {
5437 				rack->r_ctl.rc_out_at_rto = 0;
5438 			}
5439 		}
5440 	}
5441 #ifdef STATS
5442 	stats_voi_update_abs_ulong(tp->t_stats, VOI_TCP_LCWIN, rack->r_ctl.cwnd_to_use);
5443 #endif
5444 	if (rack->r_ctl.rc_rack_largest_cwnd < rack->r_ctl.cwnd_to_use) {
5445 		rack->r_ctl.rc_rack_largest_cwnd = rack->r_ctl.cwnd_to_use;
5446 	}
5447 	if ((rack->rc_initial_ss_comp == 0) &&
5448 	    (tp->snd_cwnd >= tp->snd_ssthresh)) {
5449 		/*
5450 		 * The cwnd has grown beyond ssthresh we have
5451 		 * entered ca and completed our first Slowstart.
5452 		 */
5453 		rack->rc_initial_ss_comp = 1;
5454 	}
5455 }
5456 
5457 static void
5458 tcp_rack_partialack(struct tcpcb *tp)
5459 {
5460 	struct tcp_rack *rack;
5461 
5462 	rack = (struct tcp_rack *)tp->t_fb_ptr;
5463 	INP_WLOCK_ASSERT(tptoinpcb(tp));
5464 	/*
5465 	 * If we are doing PRR and have enough
5466 	 * room to send <or> we are pacing and prr
5467 	 * is disabled we will want to see if we
5468 	 * can send data (by setting r_wanted_output to
5469 	 * true).
5470 	 */
5471 	if ((rack->r_ctl.rc_prr_sndcnt > 0) ||
5472 	    rack->rack_no_prr)
5473 		rack->r_wanted_output = 1;
5474 }
5475 
5476 static void
5477 rack_exit_recovery(struct tcpcb *tp, struct tcp_rack *rack, int how)
5478 {
5479 	/*
5480 	 * Now exit recovery.
5481 	 */
5482 	EXIT_RECOVERY(tp->t_flags);
5483 }
5484 
5485 static void
5486 rack_post_recovery(struct tcpcb *tp, uint32_t th_ack)
5487 {
5488 	struct tcp_rack *rack;
5489 	uint32_t orig_cwnd;
5490 
5491 	orig_cwnd = tp->snd_cwnd;
5492 	INP_WLOCK_ASSERT(tptoinpcb(tp));
5493 	rack = (struct tcp_rack *)tp->t_fb_ptr;
5494 	/* only alert CC if we alerted when we entered */
5495 	if (CC_ALGO(tp)->post_recovery != NULL) {
5496 		tp->t_ccv.curack = th_ack;
5497 		CC_ALGO(tp)->post_recovery(&tp->t_ccv);
5498 		if (tp->snd_cwnd < tp->snd_ssthresh) {
5499 			/*
5500 			 * Rack has burst control and pacing
5501 			 * so lets not set this any lower than
5502 			 * snd_ssthresh per RFC-6582 (option 2).
5503 			 */
5504 			tp->snd_cwnd = tp->snd_ssthresh;
5505 		}
5506 	}
5507 	if (rack_verbose_logging && tcp_bblogging_on(rack->rc_tp)) {
5508 		union tcp_log_stackspecific log;
5509 		struct timeval tv;
5510 
5511 		memset(&log, 0, sizeof(log));
5512 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
5513 		log.u_bbr.flex1 = th_ack;
5514 		log.u_bbr.flex2 = tp->t_ccv.flags;
5515 		log.u_bbr.flex3 = tp->t_ccv.bytes_this_ack;
5516 		log.u_bbr.flex4 = tp->t_ccv.nsegs;
5517 		log.u_bbr.flex5 = V_tcp_abc_l_var;
5518 		log.u_bbr.flex6 = orig_cwnd;
5519 		log.u_bbr.flex7 = 1;  /* always doing RFC6675 SACK */
5520 		log.u_bbr.pkts_out = rack->r_ctl.rc_prr_sndcnt;
5521 		log.u_bbr.flex8 = 2;
5522 		tcp_log_event(tp, NULL, NULL, NULL, BBR_LOG_CWND, 0,
5523 			       0, &log, false, NULL, __func__, __LINE__, &tv);
5524 	}
5525 	if ((rack->rack_no_prr == 0) &&
5526 	    (rack->no_prr_addback == 0) &&
5527 	    (rack->r_ctl.rc_prr_sndcnt > 0)) {
5528 		/*
5529 		 * Suck the next prr cnt back into cwnd, but
5530 		 * only do that if we are not application limited.
5531 		 */
5532 		if (ctf_outstanding(tp) <= sbavail(&tptosocket(tp)->so_snd)) {
5533 			/*
5534 			 * We are allowed to add back to the cwnd the amount we did
5535 			 * not get out if:
5536 			 * a) no_prr_addback is off.
5537 			 * b) we are not app limited
5538 			 * c) we are doing prr
5539 			 * <and>
5540 			 * d) it is bounded by rack_prr_addbackmax (if addback is 0, then none).
5541 			 */
5542 			tp->snd_cwnd += min((ctf_fixed_maxseg(tp) * rack_prr_addbackmax),
5543 					    rack->r_ctl.rc_prr_sndcnt);
5544 		}
5545 		rack->r_ctl.rc_prr_sndcnt = 0;
5546 		rack_log_to_prr(rack, 1, 0, __LINE__);
5547 	}
5548 	rack_log_to_prr(rack, 14, orig_cwnd, __LINE__);
5549 	tp->snd_recover = tp->snd_una;
5550 	if (rack->r_ctl.dsack_persist) {
5551 		rack->r_ctl.dsack_persist--;
5552 		if (rack->r_ctl.num_dsack && (rack->r_ctl.dsack_persist == 0)) {
5553 			rack->r_ctl.num_dsack = 0;
5554 		}
5555 		rack_log_dsack_event(rack, 1, __LINE__, 0, 0);
5556 	}
5557 	if (rack->rto_from_rec == 1) {
5558 		rack->rto_from_rec = 0;
5559 		if (rack->r_ctl.rto_ssthresh > tp->snd_ssthresh)
5560 			tp->snd_ssthresh = rack->r_ctl.rto_ssthresh;
5561 	}
5562 	rack_exit_recovery(tp, rack, 1);
5563 }
5564 
5565 static void
5566 rack_cong_signal(struct tcpcb *tp, uint32_t type, uint32_t ack, int line)
5567 {
5568 	struct tcp_rack *rack;
5569 	uint32_t ssthresh_enter, cwnd_enter, in_rec_at_entry, orig_cwnd;
5570 
5571 	INP_WLOCK_ASSERT(tptoinpcb(tp));
5572 #ifdef STATS
5573 	stats_voi_update_abs_u32(tp->t_stats, VOI_TCP_CSIG, type);
5574 #endif
5575 	if (IN_RECOVERY(tp->t_flags) == 0) {
5576 		in_rec_at_entry = 0;
5577 		ssthresh_enter = tp->snd_ssthresh;
5578 		cwnd_enter = tp->snd_cwnd;
5579 	} else
5580 		in_rec_at_entry = 1;
5581 	rack = (struct tcp_rack *)tp->t_fb_ptr;
5582 	switch (type) {
5583 	case CC_NDUPACK:
5584 		tp->t_flags &= ~TF_WASFRECOVERY;
5585 		tp->t_flags &= ~TF_WASCRECOVERY;
5586 		if (!IN_FASTRECOVERY(tp->t_flags)) {
5587 			/* Check if this is the end of the initial Start-up i.e. initial slow-start */
5588 			if (rack->rc_initial_ss_comp == 0) {
5589 				/* Yep it is the end of the initial slowstart */
5590 				rack->rc_initial_ss_comp = 1;
5591 			}
5592 			rack->r_ctl.rc_prr_delivered = 0;
5593 			rack->r_ctl.rc_prr_out = 0;
5594 			rack->r_fast_output = 0;
5595 			rack->r_ctl.recovery_rxt_cnt = 0;
5596 			if (rack->rack_no_prr == 0) {
5597 				rack->r_ctl.rc_prr_sndcnt = ctf_fixed_maxseg(tp);
5598 				rack_log_to_prr(rack, 2, in_rec_at_entry, line);
5599 			}
5600 			rack->r_ctl.rc_prr_recovery_fs = tp->snd_max - tp->snd_una;
5601 			tp->snd_recover = tp->snd_max;
5602 			if (tp->t_flags2 & TF2_ECN_PERMIT)
5603 				tp->t_flags2 |= TF2_ECN_SND_CWR;
5604 		}
5605 		break;
5606 	case CC_ECN:
5607 		if (!IN_CONGRECOVERY(tp->t_flags) ||
5608 		    /*
5609 		     * Allow ECN reaction on ACK to CWR, if
5610 		     * that data segment was also CE marked.
5611 		     */
5612 		    SEQ_GEQ(ack, tp->snd_recover)) {
5613 			EXIT_CONGRECOVERY(tp->t_flags);
5614 			KMOD_TCPSTAT_INC(tcps_ecn_rcwnd);
5615 			rack->r_fast_output = 0;
5616 			tp->snd_recover = tp->snd_max + 1;
5617 			if (tp->t_flags2 & TF2_ECN_PERMIT)
5618 				tp->t_flags2 |= TF2_ECN_SND_CWR;
5619 		}
5620 		break;
5621 	case CC_RTO:
5622 		tp->t_dupacks = 0;
5623 		tp->t_bytes_acked = 0;
5624 		rack->r_fast_output = 0;
5625 		if (IN_RECOVERY(tp->t_flags))
5626 			rack_exit_recovery(tp, rack, 2);
5627 		orig_cwnd = tp->snd_cwnd;
5628 		rack_log_to_prr(rack, 16, orig_cwnd, line);
5629 		if (CC_ALGO(tp)->cong_signal == NULL) {
5630 			/* TSNH */
5631 			tp->snd_ssthresh = max(2,
5632 			    min(tp->snd_wnd, rack->r_ctl.cwnd_to_use) / 2 /
5633 			    ctf_fixed_maxseg(tp)) * ctf_fixed_maxseg(tp);
5634 			tp->snd_cwnd = ctf_fixed_maxseg(tp);
5635 		}
5636 		if (tp->t_flags2 & TF2_ECN_PERMIT)
5637 			tp->t_flags2 |= TF2_ECN_SND_CWR;
5638 		break;
5639 	case CC_RTO_ERR:
5640 		KMOD_TCPSTAT_INC(tcps_sndrexmitbad);
5641 		/* RTO was unnecessary, so reset everything. */
5642 		tp->snd_cwnd = tp->snd_cwnd_prev;
5643 		tp->snd_ssthresh = tp->snd_ssthresh_prev;
5644 		tp->snd_recover = tp->snd_recover_prev;
5645 		if (tp->t_flags & TF_WASFRECOVERY) {
5646 			ENTER_FASTRECOVERY(tp->t_flags);
5647 			tp->t_flags &= ~TF_WASFRECOVERY;
5648 		}
5649 		if (tp->t_flags & TF_WASCRECOVERY) {
5650 			ENTER_CONGRECOVERY(tp->t_flags);
5651 			tp->t_flags &= ~TF_WASCRECOVERY;
5652 		}
5653 		tp->snd_nxt = tp->snd_max;
5654 		tp->t_badrxtwin = 0;
5655 		break;
5656 	}
5657 	if ((CC_ALGO(tp)->cong_signal != NULL) &&
5658 	    (type != CC_RTO)){
5659 		tp->t_ccv.curack = ack;
5660 		CC_ALGO(tp)->cong_signal(&tp->t_ccv, type);
5661 	}
5662 	if ((in_rec_at_entry == 0) && IN_RECOVERY(tp->t_flags)) {
5663 		rack_log_to_prr(rack, 15, cwnd_enter, line);
5664 		rack->r_ctl.dsack_byte_cnt = 0;
5665 		rack->r_ctl.retran_during_recovery = 0;
5666 		rack->r_ctl.rc_cwnd_at_erec = cwnd_enter;
5667 		rack->r_ctl.rc_ssthresh_at_erec = ssthresh_enter;
5668 		rack->r_ent_rec_ns = 1;
5669 	}
5670 }
5671 
5672 static inline void
5673 rack_cc_after_idle(struct tcp_rack *rack, struct tcpcb *tp)
5674 {
5675 	uint32_t i_cwnd;
5676 
5677 	INP_WLOCK_ASSERT(tptoinpcb(tp));
5678 
5679 	if (CC_ALGO(tp)->after_idle != NULL)
5680 		CC_ALGO(tp)->after_idle(&tp->t_ccv);
5681 
5682 	if (tp->snd_cwnd == 1)
5683 		i_cwnd = tp->t_maxseg;		/* SYN(-ACK) lost */
5684 	else
5685 		i_cwnd = rc_init_window(rack);
5686 
5687 	/*
5688 	 * Being idle is no different than the initial window. If the cc
5689 	 * clamps it down below the initial window raise it to the initial
5690 	 * window.
5691 	 */
5692 	if (tp->snd_cwnd < i_cwnd) {
5693 		tp->snd_cwnd = i_cwnd;
5694 	}
5695 }
5696 
5697 /*
5698  * Indicate whether this ack should be delayed.  We can delay the ack if
5699  * following conditions are met:
5700  *	- There is no delayed ack timer in progress.
5701  *	- Our last ack wasn't a 0-sized window. We never want to delay
5702  *	  the ack that opens up a 0-sized window.
5703  *	- LRO wasn't used for this segment. We make sure by checking that the
5704  *	  segment size is not larger than the MSS.
5705  *	- Delayed acks are enabled or this is a half-synchronized T/TCP
5706  *	  connection.
5707  */
5708 #define DELAY_ACK(tp, tlen)			 \
5709 	(((tp->t_flags & TF_RXWIN0SENT) == 0) && \
5710 	((tp->t_flags & TF_DELACK) == 0) &&	 \
5711 	(tlen <= tp->t_maxseg) &&		 \
5712 	(tp->t_delayed_ack || (tp->t_flags & TF_NEEDSYN)))
5713 
5714 static struct rack_sendmap *
5715 rack_find_lowest_rsm(struct tcp_rack *rack)
5716 {
5717 	struct rack_sendmap *rsm;
5718 
5719 	/*
5720 	 * Walk the time-order transmitted list looking for an rsm that is
5721 	 * not acked. This will be the one that was sent the longest time
5722 	 * ago that is still outstanding.
5723 	 */
5724 	TAILQ_FOREACH(rsm, &rack->r_ctl.rc_tmap, r_tnext) {
5725 		if (rsm->r_flags & RACK_ACKED) {
5726 			continue;
5727 		}
5728 		goto finish;
5729 	}
5730 finish:
5731 	return (rsm);
5732 }
5733 
5734 static struct rack_sendmap *
5735 rack_find_high_nonack(struct tcp_rack *rack, struct rack_sendmap *rsm)
5736 {
5737 	struct rack_sendmap *prsm;
5738 
5739 	/*
5740 	 * Walk the sequence order list backward until we hit and arrive at
5741 	 * the highest seq not acked. In theory when this is called it
5742 	 * should be the last segment (which it was not).
5743 	 */
5744 	prsm = rsm;
5745 
5746 	TQHASH_FOREACH_REVERSE_FROM(prsm, rack->r_ctl.tqh) {
5747 		if (prsm->r_flags & (RACK_ACKED | RACK_HAS_FIN)) {
5748 			continue;
5749 		}
5750 		return (prsm);
5751 	}
5752 	return (NULL);
5753 }
5754 
5755 static uint32_t
5756 rack_calc_thresh_rack(struct tcp_rack *rack, uint32_t srtt, uint32_t cts, int line, int log_allowed)
5757 {
5758 	int32_t lro;
5759 	uint32_t thresh;
5760 
5761 	/*
5762 	 * lro is the flag we use to determine if we have seen reordering.
5763 	 * If it gets set we have seen reordering. The reorder logic either
5764 	 * works in one of two ways:
5765 	 *
5766 	 * If reorder-fade is configured, then we track the last time we saw
5767 	 * re-ordering occur. If we reach the point where enough time as
5768 	 * passed we no longer consider reordering as occurring.
5769 	 *
5770 	 * Or if reorder-face is 0, then once we see reordering we consider
5771 	 * the connection to alway be subject to reordering and just set lro
5772 	 * to 1.
5773 	 *
5774 	 * In the end if lro is non-zero we add the extra time for
5775 	 * reordering in.
5776 	 */
5777 	if (srtt == 0)
5778 		srtt = 1;
5779 	if (rack->r_ctl.rc_reorder_ts) {
5780 		if (rack->r_ctl.rc_reorder_fade) {
5781 			if (SEQ_GEQ(cts, rack->r_ctl.rc_reorder_ts)) {
5782 				lro = cts - rack->r_ctl.rc_reorder_ts;
5783 				if (lro == 0) {
5784 					/*
5785 					 * No time as passed since the last
5786 					 * reorder, mark it as reordering.
5787 					 */
5788 					lro = 1;
5789 				}
5790 			} else {
5791 				/* Negative time? */
5792 				lro = 0;
5793 			}
5794 			if (lro > rack->r_ctl.rc_reorder_fade) {
5795 				/* Turn off reordering seen too */
5796 				rack->r_ctl.rc_reorder_ts = 0;
5797 				lro = 0;
5798 			}
5799 		} else {
5800 			/* Reodering does not fade */
5801 			lro = 1;
5802 		}
5803 	} else {
5804 		lro = 0;
5805 	}
5806 	if (rack->rc_rack_tmr_std_based == 0) {
5807 		thresh = srtt + rack->r_ctl.rc_pkt_delay;
5808 	} else {
5809 		/* Standards based pkt-delay is 1/4 srtt */
5810 		thresh = srtt +  (srtt >> 2);
5811 	}
5812 	if (lro && (rack->rc_rack_tmr_std_based == 0)) {
5813 		/* It must be set, if not you get 1/4 rtt */
5814 		if (rack->r_ctl.rc_reorder_shift)
5815 			thresh += (srtt >> rack->r_ctl.rc_reorder_shift);
5816 		else
5817 			thresh += (srtt >> 2);
5818 	}
5819 	if (rack->rc_rack_use_dsack &&
5820 	    lro &&
5821 	    (rack->r_ctl.num_dsack > 0)) {
5822 		/*
5823 		 * We only increase the reordering window if we
5824 		 * have seen reordering <and> we have a DSACK count.
5825 		 */
5826 		thresh += rack->r_ctl.num_dsack * (srtt >> 2);
5827 		if (log_allowed)
5828 			rack_log_dsack_event(rack, 4, line, srtt, thresh);
5829 	}
5830 	/* SRTT * 2 is the ceiling */
5831 	if (thresh > (srtt * 2)) {
5832 		thresh = srtt * 2;
5833 	}
5834 	/* And we don't want it above the RTO max either */
5835 	if (thresh > rack_rto_max) {
5836 		thresh = rack_rto_max;
5837 	}
5838 	if (log_allowed)
5839 		rack_log_dsack_event(rack, 6, line,  srtt, thresh);
5840 	return (thresh);
5841 }
5842 
5843 static uint32_t
5844 rack_calc_thresh_tlp(struct tcpcb *tp, struct tcp_rack *rack,
5845 		     struct rack_sendmap *rsm, uint32_t srtt)
5846 {
5847 	struct rack_sendmap *prsm;
5848 	uint32_t thresh, len;
5849 	int segsiz;
5850 
5851 	if (srtt == 0)
5852 		srtt = 1;
5853 	if (rack->r_ctl.rc_tlp_threshold)
5854 		thresh = srtt + (srtt / rack->r_ctl.rc_tlp_threshold);
5855 	else
5856 		thresh = (srtt * 2);
5857 
5858 	/* Get the previous sent packet, if any */
5859 	segsiz = min(ctf_fixed_maxseg(tp), rack->r_ctl.rc_pace_min_segs);
5860 	len = rsm->r_end - rsm->r_start;
5861 	if (rack->rack_tlp_threshold_use == TLP_USE_ID) {
5862 		/* Exactly like the ID */
5863 		if (((tp->snd_max - tp->snd_una) - rack->r_ctl.rc_sacked + rack->r_ctl.rc_holes_rxt) <= segsiz) {
5864 			uint32_t alt_thresh;
5865 			/*
5866 			 * Compensate for delayed-ack with the d-ack time.
5867 			 */
5868 			alt_thresh = srtt + (srtt / 2) + rack_delayed_ack_time;
5869 			if (alt_thresh > thresh)
5870 				thresh = alt_thresh;
5871 		}
5872 	} else if (rack->rack_tlp_threshold_use == TLP_USE_TWO_ONE) {
5873 		/* 2.1 behavior */
5874 		prsm = TAILQ_PREV(rsm, rack_head, r_tnext);
5875 		if (prsm && (len <= segsiz)) {
5876 			/*
5877 			 * Two packets outstanding, thresh should be (2*srtt) +
5878 			 * possible inter-packet delay (if any).
5879 			 */
5880 			uint32_t inter_gap = 0;
5881 			int idx, nidx;
5882 
5883 			idx = rsm->r_rtr_cnt - 1;
5884 			nidx = prsm->r_rtr_cnt - 1;
5885 			if (rsm->r_tim_lastsent[nidx] >= prsm->r_tim_lastsent[idx]) {
5886 				/* Yes it was sent later (or at the same time) */
5887 				inter_gap = rsm->r_tim_lastsent[idx] - prsm->r_tim_lastsent[nidx];
5888 			}
5889 			thresh += inter_gap;
5890 		} else if (len <= segsiz) {
5891 			/*
5892 			 * Possibly compensate for delayed-ack.
5893 			 */
5894 			uint32_t alt_thresh;
5895 
5896 			alt_thresh = srtt + (srtt / 2) + rack_delayed_ack_time;
5897 			if (alt_thresh > thresh)
5898 				thresh = alt_thresh;
5899 		}
5900 	} else if (rack->rack_tlp_threshold_use == TLP_USE_TWO_TWO) {
5901 		/* 2.2 behavior */
5902 		if (len <= segsiz) {
5903 			uint32_t alt_thresh;
5904 			/*
5905 			 * Compensate for delayed-ack with the d-ack time.
5906 			 */
5907 			alt_thresh = srtt + (srtt / 2) + rack_delayed_ack_time;
5908 			if (alt_thresh > thresh)
5909 				thresh = alt_thresh;
5910 		}
5911 	}
5912 	/* Not above an RTO */
5913 	if (thresh > tp->t_rxtcur) {
5914 		thresh = tp->t_rxtcur;
5915 	}
5916 	/* Not above a RTO max */
5917 	if (thresh > rack_rto_max) {
5918 		thresh = rack_rto_max;
5919 	}
5920 	/* Apply user supplied min TLP */
5921 	if (thresh < rack_tlp_min) {
5922 		thresh = rack_tlp_min;
5923 	}
5924 	return (thresh);
5925 }
5926 
5927 static uint32_t
5928 rack_grab_rtt(struct tcpcb *tp, struct tcp_rack *rack)
5929 {
5930 	/*
5931 	 * We want the rack_rtt which is the
5932 	 * last rtt we measured. However if that
5933 	 * does not exist we fallback to the srtt (which
5934 	 * we probably will never do) and then as a last
5935 	 * resort we use RACK_INITIAL_RTO if no srtt is
5936 	 * yet set.
5937 	 */
5938 	if (rack->rc_rack_rtt)
5939 		return (rack->rc_rack_rtt);
5940 	else if (tp->t_srtt == 0)
5941 		return (RACK_INITIAL_RTO);
5942 	return (tp->t_srtt);
5943 }
5944 
5945 static struct rack_sendmap *
5946 rack_check_recovery_mode(struct tcpcb *tp, uint32_t tsused)
5947 {
5948 	/*
5949 	 * Check to see that we don't need to fall into recovery. We will
5950 	 * need to do so if our oldest transmit is past the time we should
5951 	 * have had an ack.
5952 	 */
5953 	struct tcp_rack *rack;
5954 	struct rack_sendmap *rsm;
5955 	int32_t idx;
5956 	uint32_t srtt, thresh;
5957 
5958 	rack = (struct tcp_rack *)tp->t_fb_ptr;
5959 	if (tqhash_empty(rack->r_ctl.tqh)) {
5960 		return (NULL);
5961 	}
5962 	rsm = TAILQ_FIRST(&rack->r_ctl.rc_tmap);
5963 	if (rsm == NULL)
5964 		return (NULL);
5965 
5966 
5967 	if (rsm->r_flags & RACK_ACKED) {
5968 		rsm = rack_find_lowest_rsm(rack);
5969 		if (rsm == NULL)
5970 			return (NULL);
5971 	}
5972 	idx = rsm->r_rtr_cnt - 1;
5973 	srtt = rack_grab_rtt(tp, rack);
5974 	thresh = rack_calc_thresh_rack(rack, srtt, tsused, __LINE__, 1);
5975 	if (TSTMP_LT(tsused, ((uint32_t)rsm->r_tim_lastsent[idx]))) {
5976 		return (NULL);
5977 	}
5978 	if ((tsused - ((uint32_t)rsm->r_tim_lastsent[idx])) < thresh) {
5979 		return (NULL);
5980 	}
5981 	/* Ok if we reach here we are over-due and this guy can be sent */
5982 	rack_cong_signal(tp, CC_NDUPACK, tp->snd_una, __LINE__);
5983 	return (rsm);
5984 }
5985 
5986 static uint32_t
5987 rack_get_persists_timer_val(struct tcpcb *tp, struct tcp_rack *rack)
5988 {
5989 	int32_t t;
5990 	int32_t tt;
5991 	uint32_t ret_val;
5992 
5993 	t = (tp->t_srtt + (tp->t_rttvar << 2));
5994 	RACK_TCPT_RANGESET(tt, t * tcp_backoff[tp->t_rxtshift],
5995  	    rack_persist_min, rack_persist_max, rack->r_ctl.timer_slop);
5996 	rack->r_ctl.rc_hpts_flags |= PACE_TMR_PERSIT;
5997 	ret_val = (uint32_t)tt;
5998 	return (ret_val);
5999 }
6000 
6001 static uint32_t
6002 rack_timer_start(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cts, int sup_rack)
6003 {
6004 	/*
6005 	 * Start the FR timer, we do this based on getting the first one in
6006 	 * the rc_tmap. Note that if its NULL we must stop the timer. in all
6007 	 * events we need to stop the running timer (if its running) before
6008 	 * starting the new one.
6009 	 */
6010 	uint32_t thresh, exp, to, srtt, time_since_sent, tstmp_touse;
6011 	uint32_t srtt_cur;
6012 	int32_t idx;
6013 	int32_t is_tlp_timer = 0;
6014 	struct rack_sendmap *rsm;
6015 
6016 	if (rack->t_timers_stopped) {
6017 		/* All timers have been stopped none are to run */
6018 		return (0);
6019 	}
6020 	if (rack->rc_in_persist) {
6021 		/* We can't start any timer in persists */
6022 		return (rack_get_persists_timer_val(tp, rack));
6023 	}
6024 	rack->rc_on_min_to = 0;
6025 	if ((tp->t_state < TCPS_ESTABLISHED) ||
6026 	    ((tp->t_flags & TF_SACK_PERMIT) == 0)) {
6027 		goto activate_rxt;
6028 	}
6029 	rsm = TAILQ_FIRST(&rack->r_ctl.rc_tmap);
6030 	if ((rsm == NULL) || sup_rack) {
6031 		/* Nothing on the send map or no rack */
6032 activate_rxt:
6033 		time_since_sent = 0;
6034 		rsm = TAILQ_FIRST(&rack->r_ctl.rc_tmap);
6035 		if (rsm) {
6036 			/*
6037 			 * Should we discount the RTX timer any?
6038 			 *
6039 			 * We want to discount it the smallest amount.
6040 			 * If a timer (Rack/TLP or RXT) has gone off more
6041 			 * recently thats the discount we want to use (now - timer time).
6042 			 * If the retransmit of the oldest packet was more recent then
6043 			 * we want to use that (now - oldest-packet-last_transmit_time).
6044 			 *
6045 			 */
6046 			idx = rsm->r_rtr_cnt - 1;
6047 			if (TSTMP_GEQ(rack->r_ctl.rc_tlp_rxt_last_time, ((uint32_t)rsm->r_tim_lastsent[idx])))
6048 				tstmp_touse = (uint32_t)rack->r_ctl.rc_tlp_rxt_last_time;
6049 			else
6050 				tstmp_touse = (uint32_t)rsm->r_tim_lastsent[idx];
6051 			if (TSTMP_GT(cts, tstmp_touse))
6052 			    time_since_sent = cts - tstmp_touse;
6053 		}
6054 		if (SEQ_LT(tp->snd_una, tp->snd_max) ||
6055 		    sbavail(&tptosocket(tp)->so_snd)) {
6056 			rack->r_ctl.rc_hpts_flags |= PACE_TMR_RXT;
6057 			to = tp->t_rxtcur;
6058 			if (to > time_since_sent)
6059 				to -= time_since_sent;
6060 			else
6061 				to = rack->r_ctl.rc_min_to;
6062 			if (to == 0)
6063 				to = 1;
6064 			/* Special case for KEEPINIT */
6065 			if ((TCPS_HAVEESTABLISHED(tp->t_state) == 0) &&
6066 			    (TP_KEEPINIT(tp) != 0) &&
6067 			    rsm) {
6068 				/*
6069 				 * We have to put a ceiling on the rxt timer
6070 				 * of the keep-init timeout.
6071 				 */
6072 				uint32_t max_time, red;
6073 
6074 				max_time = TICKS_2_USEC(TP_KEEPINIT(tp));
6075 				if (TSTMP_GT(cts, (uint32_t)rsm->r_tim_lastsent[0])) {
6076 					red = (cts - (uint32_t)rsm->r_tim_lastsent[0]);
6077 					if (red < max_time)
6078 						max_time -= red;
6079 					else
6080 						max_time = 1;
6081 				}
6082 				/* Reduce timeout to the keep value if needed */
6083 				if (max_time < to)
6084 					to = max_time;
6085 			}
6086 			return (to);
6087 		}
6088 		return (0);
6089 	}
6090 	if (rsm->r_flags & RACK_ACKED) {
6091 		rsm = rack_find_lowest_rsm(rack);
6092 		if (rsm == NULL) {
6093 			/* No lowest? */
6094 			goto activate_rxt;
6095 		}
6096 	}
6097 	/* Convert from ms to usecs */
6098 	if ((rsm->r_flags & RACK_SACK_PASSED) ||
6099 	    (rsm->r_flags & RACK_RWND_COLLAPSED) ||
6100 	    (rsm->r_dupack >= DUP_ACK_THRESHOLD)) {
6101 		if ((tp->t_flags & TF_SENTFIN) &&
6102 		    ((tp->snd_max - tp->snd_una) == 1) &&
6103 		    (rsm->r_flags & RACK_HAS_FIN)) {
6104 			/*
6105 			 * We don't start a rack timer if all we have is a
6106 			 * FIN outstanding.
6107 			 */
6108 			goto activate_rxt;
6109 		}
6110 		if ((rack->use_rack_rr == 0) &&
6111 		    (IN_FASTRECOVERY(tp->t_flags)) &&
6112 		    (rack->rack_no_prr == 0) &&
6113 		     (rack->r_ctl.rc_prr_sndcnt  < ctf_fixed_maxseg(tp))) {
6114 			/*
6115 			 * We are not cheating, in recovery  and
6116 			 * not enough ack's to yet get our next
6117 			 * retransmission out.
6118 			 *
6119 			 * Note that classified attackers do not
6120 			 * get to use the rack-cheat.
6121 			 */
6122 			goto activate_tlp;
6123 		}
6124 		srtt = rack_grab_rtt(tp, rack);
6125 		thresh = rack_calc_thresh_rack(rack, srtt, cts, __LINE__, 1);
6126 		idx = rsm->r_rtr_cnt - 1;
6127 		exp = ((uint32_t)rsm->r_tim_lastsent[idx]) + thresh;
6128 		if (SEQ_GEQ(exp, cts)) {
6129 			to = exp - cts;
6130 			if (to < rack->r_ctl.rc_min_to) {
6131 				to = rack->r_ctl.rc_min_to;
6132 				if (rack->r_rr_config == 3)
6133 					rack->rc_on_min_to = 1;
6134 			}
6135 		} else {
6136 			to = rack->r_ctl.rc_min_to;
6137 			if (rack->r_rr_config == 3)
6138 				rack->rc_on_min_to = 1;
6139 		}
6140 	} else {
6141 		/* Ok we need to do a TLP not RACK */
6142 activate_tlp:
6143 		if ((rack->rc_tlp_in_progress != 0) &&
6144 		    (rack->r_ctl.rc_tlp_cnt_out >= rack_tlp_limit)) {
6145 			/*
6146 			 * The previous send was a TLP and we have sent
6147 			 * N TLP's without sending new data.
6148 			 */
6149 			goto activate_rxt;
6150 		}
6151 		rsm = TAILQ_LAST_FAST(&rack->r_ctl.rc_tmap, rack_sendmap, r_tnext);
6152 		if (rsm == NULL) {
6153 			/* We found no rsm to TLP with. */
6154 			goto activate_rxt;
6155 		}
6156 		if (rsm->r_flags & RACK_HAS_FIN) {
6157 			/* If its a FIN we dont do TLP */
6158 			rsm = NULL;
6159 			goto activate_rxt;
6160 		}
6161 		idx = rsm->r_rtr_cnt - 1;
6162 		time_since_sent = 0;
6163 		if (TSTMP_GEQ(((uint32_t)rsm->r_tim_lastsent[idx]), rack->r_ctl.rc_tlp_rxt_last_time))
6164 			tstmp_touse = (uint32_t)rsm->r_tim_lastsent[idx];
6165 		else
6166 			tstmp_touse = (uint32_t)rack->r_ctl.rc_tlp_rxt_last_time;
6167 		if (TSTMP_GT(cts, tstmp_touse))
6168 		    time_since_sent = cts - tstmp_touse;
6169 		is_tlp_timer = 1;
6170 		if (tp->t_srtt) {
6171 			if ((rack->rc_srtt_measure_made == 0) &&
6172 			    (tp->t_srtt == 1)) {
6173 				/*
6174 				 * If another stack as run and set srtt to 1,
6175 				 * then the srtt was 0, so lets use the initial.
6176 				 */
6177 				srtt = RACK_INITIAL_RTO;
6178 			} else {
6179 				srtt_cur = tp->t_srtt;
6180 				srtt = srtt_cur;
6181 			}
6182 		} else
6183 			srtt = RACK_INITIAL_RTO;
6184 		/*
6185 		 * If the SRTT is not keeping up and the
6186 		 * rack RTT has spiked we want to use
6187 		 * the last RTT not the smoothed one.
6188 		 */
6189 		if (rack_tlp_use_greater &&
6190 		    tp->t_srtt &&
6191 		    (srtt < rack_grab_rtt(tp, rack))) {
6192 			srtt = rack_grab_rtt(tp, rack);
6193 		}
6194 		thresh = rack_calc_thresh_tlp(tp, rack, rsm, srtt);
6195 		if (thresh > time_since_sent) {
6196 			to = thresh - time_since_sent;
6197 		} else {
6198 			to = rack->r_ctl.rc_min_to;
6199 			rack_log_alt_to_to_cancel(rack,
6200 						  thresh,		/* flex1 */
6201 						  time_since_sent,	/* flex2 */
6202 						  tstmp_touse,		/* flex3 */
6203 						  rack->r_ctl.rc_tlp_rxt_last_time, /* flex4 */
6204 						  (uint32_t)rsm->r_tim_lastsent[idx],
6205 						  srtt,
6206 						  idx, 99);
6207 		}
6208 		if (to < rack_tlp_min) {
6209 			to = rack_tlp_min;
6210 		}
6211 		if (to > TICKS_2_USEC(tcp_rexmit_max)) {
6212 			/*
6213 			 * If the TLP time works out to larger than the max
6214 			 * RTO lets not do TLP.. just RTO.
6215 			 */
6216 			goto activate_rxt;
6217 		}
6218 	}
6219 	if (is_tlp_timer == 0) {
6220 		rack->r_ctl.rc_hpts_flags |= PACE_TMR_RACK;
6221 	} else {
6222 		rack->r_ctl.rc_hpts_flags |= PACE_TMR_TLP;
6223 	}
6224 	if (to == 0)
6225 		to = 1;
6226 	return (to);
6227 }
6228 
6229 static void
6230 rack_enter_persist(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cts, tcp_seq snd_una)
6231 {
6232 	if (rack->rc_in_persist == 0) {
6233 		if (tp->t_flags & TF_GPUTINPROG) {
6234 			/*
6235 			 * Stop the goodput now, the calling of the
6236 			 * measurement function clears the flag.
6237 			 */
6238 			rack_do_goodput_measurement(tp, rack, tp->snd_una, __LINE__,
6239 						    RACK_QUALITY_PERSIST);
6240 		}
6241 #ifdef NETFLIX_SHARED_CWND
6242 		if (rack->r_ctl.rc_scw) {
6243 			tcp_shared_cwnd_idle(rack->r_ctl.rc_scw, rack->r_ctl.rc_scw_index);
6244 			rack->rack_scwnd_is_idle = 1;
6245 		}
6246 #endif
6247 		rack->r_ctl.rc_went_idle_time = cts;
6248 		if (rack->r_ctl.rc_went_idle_time == 0)
6249 			rack->r_ctl.rc_went_idle_time = 1;
6250 		if (rack->lt_bw_up) {
6251 			/* Suspend our LT BW measurement */
6252 			uint64_t tmark;
6253 
6254 			rack->r_ctl.lt_bw_bytes += (snd_una - rack->r_ctl.lt_seq);
6255 			rack->r_ctl.lt_seq = snd_una;
6256 			tmark = tcp_tv_to_lusec(&rack->r_ctl.act_rcv_time);
6257 			if (tmark >= rack->r_ctl.lt_timemark) {
6258 				rack->r_ctl.lt_bw_time += (tmark - rack->r_ctl.lt_timemark);
6259 			}
6260 			rack->r_ctl.lt_timemark = tmark;
6261 			rack->lt_bw_up = 0;
6262 			rack->r_persist_lt_bw_off = 1;
6263 		}
6264 		rack_timer_cancel(tp, rack, cts, __LINE__);
6265 		rack->r_ctl.persist_lost_ends = 0;
6266 		rack->probe_not_answered = 0;
6267 		rack->forced_ack = 0;
6268 		tp->t_rxtshift = 0;
6269 		RACK_TCPT_RANGESET(tp->t_rxtcur, RACK_REXMTVAL(tp),
6270 			      rack_rto_min, rack_rto_max, rack->r_ctl.timer_slop);
6271 		rack->rc_in_persist = 1;
6272 	}
6273 }
6274 
6275 static void
6276 rack_exit_persist(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cts)
6277 {
6278 	if (tcp_in_hpts(rack->rc_tp)) {
6279 		tcp_hpts_remove(rack->rc_tp);
6280 		rack->r_ctl.rc_hpts_flags = 0;
6281 	}
6282 #ifdef NETFLIX_SHARED_CWND
6283 	if (rack->r_ctl.rc_scw) {
6284 		tcp_shared_cwnd_active(rack->r_ctl.rc_scw, rack->r_ctl.rc_scw_index);
6285 		rack->rack_scwnd_is_idle = 0;
6286 	}
6287 #endif
6288 	if (rack->rc_gp_dyn_mul &&
6289 	    (rack->use_fixed_rate == 0) &&
6290 	    (rack->rc_always_pace)) {
6291 		/*
6292 		 * Do we count this as if a probe-rtt just
6293 		 * finished?
6294 		 */
6295 		uint32_t time_idle, idle_min;
6296 
6297 		time_idle = cts - rack->r_ctl.rc_went_idle_time;
6298 		idle_min = rack_min_probertt_hold;
6299 		if (rack_probertt_gpsrtt_cnt_div) {
6300 			uint64_t extra;
6301 			extra = (uint64_t)rack->r_ctl.rc_gp_srtt *
6302 				(uint64_t)rack_probertt_gpsrtt_cnt_mul;
6303 			extra /= (uint64_t)rack_probertt_gpsrtt_cnt_div;
6304 			idle_min += (uint32_t)extra;
6305 		}
6306 		if (time_idle >= idle_min) {
6307 			/* Yes, we count it as a probe-rtt. */
6308 			uint32_t us_cts;
6309 
6310 			us_cts = tcp_get_usecs(NULL);
6311 			if (rack->in_probe_rtt == 0) {
6312 				rack->r_ctl.rc_lower_rtt_us_cts = us_cts;
6313 				rack->r_ctl.rc_time_probertt_entered = rack->r_ctl.rc_lower_rtt_us_cts;
6314 				rack->r_ctl.rc_time_probertt_starts = rack->r_ctl.rc_lower_rtt_us_cts;
6315 				rack->r_ctl.rc_time_of_last_probertt = rack->r_ctl.rc_lower_rtt_us_cts;
6316 			} else {
6317 				rack_exit_probertt(rack, us_cts);
6318 			}
6319 		}
6320 	}
6321 	if (rack->r_persist_lt_bw_off) {
6322 		/* Continue where we left off */
6323 		rack->r_ctl.lt_timemark = tcp_get_u64_usecs(NULL);
6324 		rack->lt_bw_up = 1;
6325 		rack->r_persist_lt_bw_off = 0;
6326 	}
6327 	rack->rc_in_persist = 0;
6328 	rack->r_ctl.rc_went_idle_time = 0;
6329 	tp->t_rxtshift = 0;
6330 	RACK_TCPT_RANGESET(tp->t_rxtcur, RACK_REXMTVAL(tp),
6331 	   rack_rto_min, rack_rto_max, rack->r_ctl.timer_slop);
6332 	rack->r_ctl.rc_agg_delayed = 0;
6333 	rack->r_early = 0;
6334 	rack->r_late = 0;
6335 	rack->r_ctl.rc_agg_early = 0;
6336 }
6337 
6338 static void
6339 rack_log_hpts_diag(struct tcp_rack *rack, uint32_t cts,
6340 		   struct hpts_diag *diag, struct timeval *tv)
6341 {
6342 	if (rack_verbose_logging && tcp_bblogging_on(rack->rc_tp)) {
6343 		union tcp_log_stackspecific log;
6344 
6345 		memset(&log, 0, sizeof(log));
6346 		log.u_bbr.flex1 = diag->p_nxt_slot;
6347 		log.u_bbr.flex2 = diag->p_cur_slot;
6348 		log.u_bbr.flex3 = diag->slot_req;
6349 		log.u_bbr.flex4 = diag->inp_hptsslot;
6350 		log.u_bbr.flex5 = diag->time_remaining;
6351 		log.u_bbr.flex6 = diag->need_new_to;
6352 		log.u_bbr.flex7 = diag->p_hpts_active;
6353 		log.u_bbr.flex8 = diag->p_on_min_sleep;
6354 		/* Hijack other fields as needed */
6355 		log.u_bbr.epoch = diag->have_slept;
6356 		log.u_bbr.lt_epoch = diag->yet_to_sleep;
6357 		log.u_bbr.pkts_out = diag->co_ret;
6358 		log.u_bbr.applimited = diag->hpts_sleep_time;
6359 		log.u_bbr.delivered = diag->p_prev_slot;
6360 		log.u_bbr.inflight = diag->p_runningslot;
6361 		log.u_bbr.bw_inuse = diag->wheel_slot;
6362 		log.u_bbr.rttProp = diag->wheel_cts;
6363 		log.u_bbr.timeStamp = cts;
6364 		log.u_bbr.delRate = diag->maxslots;
6365 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
6366 		    &rack->rc_inp->inp_socket->so_rcv,
6367 		    &rack->rc_inp->inp_socket->so_snd,
6368 		    BBR_LOG_HPTSDIAG, 0,
6369 		    0, &log, false, tv);
6370 	}
6371 
6372 }
6373 
6374 static void
6375 rack_log_wakeup(struct tcpcb *tp, struct tcp_rack *rack, struct sockbuf *sb, uint32_t len, int type)
6376 {
6377 	if (rack_verbose_logging && tcp_bblogging_on(rack->rc_tp)) {
6378 		union tcp_log_stackspecific log;
6379 		struct timeval tv;
6380 
6381 		memset(&log, 0, sizeof(log));
6382 		log.u_bbr.flex1 = sb->sb_flags;
6383 		log.u_bbr.flex2 = len;
6384 		log.u_bbr.flex3 = sb->sb_state;
6385 		log.u_bbr.flex8 = type;
6386 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
6387 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
6388 		    &rack->rc_inp->inp_socket->so_rcv,
6389 		    &rack->rc_inp->inp_socket->so_snd,
6390 		    TCP_LOG_SB_WAKE, 0,
6391 		    len, &log, false, &tv);
6392 	}
6393 }
6394 
6395 static void
6396 rack_start_hpts_timer (struct tcp_rack *rack, struct tcpcb *tp, uint32_t cts,
6397       int32_t usecs, uint32_t tot_len_this_send, int sup_rack)
6398 {
6399 	struct hpts_diag diag;
6400 	struct inpcb *inp = tptoinpcb(tp);
6401 	struct timeval tv;
6402 	uint32_t delayed_ack = 0;
6403 	uint32_t hpts_timeout;
6404 	uint32_t entry_usecs = usecs;
6405 	uint8_t stopped;
6406 	uint32_t left = 0;
6407 	uint32_t us_cts;
6408 
6409 	if ((tp->t_state == TCPS_CLOSED) ||
6410 	    (tp->t_state == TCPS_LISTEN)) {
6411 		return;
6412 	}
6413 	if (tcp_in_hpts(tp)) {
6414 		/* Already on the pacer */
6415 		return;
6416 	}
6417 	stopped = rack->rc_tmr_stopped;
6418 	if (stopped && TSTMP_GT(rack->r_ctl.rc_timer_exp, cts)) {
6419 		left = rack->r_ctl.rc_timer_exp - cts;
6420 	}
6421 	rack->r_ctl.rc_timer_exp = 0;
6422 	rack->r_ctl.rc_hpts_flags = 0;
6423 	us_cts = tcp_get_usecs(&tv);
6424 	/* Now early/late accounting */
6425 	rack_log_pacing_delay_calc(rack, entry_usecs, usecs, 0, 0, 0, 26, __LINE__, NULL, 0);
6426 	if (rack->r_early && (rack->rc_ack_can_sendout_data == 0)) {
6427 		/*
6428 		 * We have a early carry over set,
6429 		 * we can always add more time so we
6430 		 * can always make this compensation.
6431 		 *
6432 		 * Note if ack's are allowed to wake us do not
6433 		 * penalize the next timer for being awoke
6434 		 * by an ack aka the rc_agg_early (non-paced mode).
6435 		 */
6436 		usecs += rack->r_ctl.rc_agg_early;
6437 		rack->r_early = 0;
6438 		rack->r_ctl.rc_agg_early = 0;
6439 	}
6440 	if ((rack->r_late) &&
6441 	    ((rack->r_use_hpts_min == 0) || (rack->dgp_on == 0))) {
6442 		/*
6443 		 * This is harder, we can
6444 		 * compensate some but it
6445 		 * really depends on what
6446 		 * the current pacing time is.
6447 		 */
6448 		if (rack->r_ctl.rc_agg_delayed >= usecs) {
6449 			/*
6450 			 * We can't compensate for it all.
6451 			 * And we have to have some time
6452 			 * on the clock. We always have a min
6453 			 * 10 HPTS timer units (10 x 10 i.e. 100 usecs).
6454 			 */
6455 			if (usecs <= HPTS_USECS_PER_SLOT) {
6456 				/* We gain delay */
6457 				rack->r_ctl.rc_agg_delayed += (HPTS_USECS_PER_SLOT - usecs);
6458 				usecs = HPTS_USECS_PER_SLOT;
6459 			} else {
6460 				/* We take off some */
6461 				rack->r_ctl.rc_agg_delayed -= (usecs - HPTS_USECS_PER_SLOT);
6462 				usecs = HPTS_USECS_PER_SLOT;
6463 			}
6464 		} else {
6465 			usecs -= rack->r_ctl.rc_agg_delayed;
6466 			rack->r_ctl.rc_agg_delayed = 0;
6467 			/* Make sure we have 100 useconds at minimum */
6468 			if (usecs < HPTS_USECS_PER_SLOT) {
6469 				rack->r_ctl.rc_agg_delayed = HPTS_USECS_PER_SLOT - usecs;
6470 				usecs = HPTS_USECS_PER_SLOT;
6471 			}
6472 			if (rack->r_ctl.rc_agg_delayed == 0)
6473 				rack->r_late = 0;
6474 		}
6475 	} else if (rack->r_late) {
6476 		/* r_use_hpts_min is on and so is DGP */
6477 		uint32_t max_red;
6478 
6479 		max_red = (usecs * rack->r_ctl.max_reduction) / 100;
6480 		if (max_red >= rack->r_ctl.rc_agg_delayed) {
6481 			usecs -= rack->r_ctl.rc_agg_delayed;
6482 			rack->r_ctl.rc_agg_delayed = 0;
6483 		} else {
6484 			usecs -= max_red;
6485 			rack->r_ctl.rc_agg_delayed -= max_red;
6486 		}
6487 	}
6488 	if ((rack->r_use_hpts_min == 1) &&
6489 	    (usecs > 0) &&
6490 	    (rack->dgp_on == 1)) {
6491 		/*
6492 		 * We are enforcing a min pacing timer
6493 		 * based on our hpts min timeout.
6494 		 */
6495 		uint32_t min;
6496 
6497 		min = get_hpts_min_sleep_time();
6498 		if (min > usecs) {
6499 			usecs = min;
6500 		}
6501 	}
6502 	hpts_timeout = rack_timer_start(tp, rack, cts, sup_rack);
6503 	if (tp->t_flags & TF_DELACK) {
6504 		delayed_ack = TICKS_2_USEC(tcp_delacktime);
6505 		rack->r_ctl.rc_hpts_flags |= PACE_TMR_DELACK;
6506 	}
6507 	if (delayed_ack && ((hpts_timeout == 0) ||
6508 			    (delayed_ack < hpts_timeout)))
6509 		hpts_timeout = delayed_ack;
6510 	else
6511 		rack->r_ctl.rc_hpts_flags &= ~PACE_TMR_DELACK;
6512 	/*
6513 	 * If no timers are going to run and we will fall off the hptsi
6514 	 * wheel, we resort to a keep-alive timer if its configured.
6515 	 */
6516 	if ((hpts_timeout == 0) &&
6517 	    (usecs == 0)) {
6518 		if ((V_tcp_always_keepalive || inp->inp_socket->so_options & SO_KEEPALIVE) &&
6519 		    (tp->t_state <= TCPS_CLOSING)) {
6520 			/*
6521 			 * Ok we have no timer (persists, rack, tlp, rxt  or
6522 			 * del-ack), we don't have segments being paced. So
6523 			 * all that is left is the keepalive timer.
6524 			 */
6525 			if (TCPS_HAVEESTABLISHED(tp->t_state)) {
6526 				/* Get the established keep-alive time */
6527 				hpts_timeout = TICKS_2_USEC(TP_KEEPIDLE(tp));
6528 			} else {
6529 				/*
6530 				 * Get the initial setup keep-alive time,
6531 				 * note that this is probably not going to
6532 				 * happen, since rack will be running a rxt timer
6533 				 * if a SYN of some sort is outstanding. It is
6534 				 * actually handled in rack_timeout_rxt().
6535 				 */
6536 				hpts_timeout = TICKS_2_USEC(TP_KEEPINIT(tp));
6537 			}
6538 			rack->r_ctl.rc_hpts_flags |= PACE_TMR_KEEP;
6539 			if (rack->in_probe_rtt) {
6540 				/*
6541 				 * We want to instead not wake up a long time from
6542 				 * now but to wake up about the time we would
6543 				 * exit probe-rtt and initiate a keep-alive ack.
6544 				 * This will get us out of probe-rtt and update
6545 				 * our min-rtt.
6546 				 */
6547 				hpts_timeout = rack_min_probertt_hold;
6548 			}
6549 		}
6550 	}
6551 	if (left && (stopped & (PACE_TMR_KEEP | PACE_TMR_DELACK)) ==
6552 	    (rack->r_ctl.rc_hpts_flags & PACE_TMR_MASK)) {
6553 		/*
6554 		 * RACK, TLP, persists and RXT timers all are restartable
6555 		 * based on actions input .. i.e we received a packet (ack
6556 		 * or sack) and that changes things (rw, or snd_una etc).
6557 		 * Thus we can restart them with a new value. For
6558 		 * keep-alive, delayed_ack we keep track of what was left
6559 		 * and restart the timer with a smaller value.
6560 		 */
6561 		if (left < hpts_timeout)
6562 			hpts_timeout = left;
6563 	}
6564 	if (hpts_timeout) {
6565 		/*
6566 		 * Hack alert for now we can't time-out over 2,147,483
6567 		 * seconds (a bit more than 596 hours), which is probably ok
6568 		 * :).
6569 		 */
6570 		if (hpts_timeout > 0x7ffffffe)
6571 			hpts_timeout = 0x7ffffffe;
6572 		rack->r_ctl.rc_timer_exp = cts + hpts_timeout;
6573 	}
6574 	rack_log_pacing_delay_calc(rack, entry_usecs, usecs, hpts_timeout, 0, 0, 27, __LINE__, NULL, 0);
6575 	if ((rack->gp_ready == 0) &&
6576 	    (rack->use_fixed_rate == 0) &&
6577 	    (hpts_timeout < usecs) &&
6578 	    (rack->r_ctl.rc_hpts_flags & (PACE_TMR_TLP|PACE_TMR_RXT))) {
6579 		/*
6580 		 * We have no good estimate yet for the
6581 		 * old clunky burst mitigation or the
6582 		 * real pacing. And the tlp or rxt is smaller
6583 		 * than the pacing calculation. Lets not
6584 		 * pace that long since we know the calculation
6585 		 * so far is not accurate.
6586 		 */
6587 		usecs = hpts_timeout;
6588 	}
6589 	/**
6590 	 * Turn off all the flags for queuing by default. The
6591 	 * flags have important meanings to what happens when
6592 	 * LRO interacts with the transport. Most likely (by default now)
6593 	 * mbuf_queueing and ack compression are on. So the transport
6594 	 * has a couple of flags that control what happens (if those
6595 	 * are not on then these flags won't have any effect since it
6596 	 * won't go through the queuing LRO path).
6597 	 *
6598 	 * TF2_MBUF_QUEUE_READY - This flags says that I am busy
6599 	 *                        pacing output, so don't disturb. But
6600 	 *                        it also means LRO can wake me if there
6601 	 *                        is a SACK arrival.
6602 	 *
6603 	 * TF2_DONT_SACK_QUEUE - This flag is used in conjunction
6604 	 *                       with the above flag (QUEUE_READY) and
6605 	 *                       when present it says don't even wake me
6606 	 *                       if a SACK arrives.
6607 	 *
6608 	 * The idea behind these flags is that if we are pacing we
6609 	 * set the MBUF_QUEUE_READY and only get woken up if
6610 	 * a SACK arrives (which could change things) or if
6611 	 * our pacing timer expires. If, however, we have a rack
6612 	 * timer running, then we don't even want a sack to wake
6613 	 * us since the rack timer has to expire before we can send.
6614 	 *
6615 	 * Other cases should usually have none of the flags set
6616 	 * so LRO can call into us.
6617 	 */
6618 	tp->t_flags2 &= ~(TF2_DONT_SACK_QUEUE|TF2_MBUF_QUEUE_READY);
6619 	if (usecs) {
6620 		rack->r_ctl.rc_hpts_flags |= PACE_PKT_OUTPUT;
6621 		rack->r_ctl.rc_last_output_to = us_cts + usecs;
6622 		/*
6623 		 * A pacing timer (usecs microseconds) is being set, in
6624 		 * such a case we cannot send (we are blocked by
6625 		 * the timer). So lets tell LRO that it should not
6626 		 * wake us unless there is a SACK. Note this only
6627 		 * will be effective if mbuf queueing is on or
6628 		 * compressed acks are being processed.
6629 		 */
6630 		tp->t_flags2 |= TF2_MBUF_QUEUE_READY;
6631 		/*
6632 		 * But wait if we have a Rack timer running
6633 		 * even a SACK should not disturb us (with
6634 		 * the exception of r_rr_config 3).
6635 		 */
6636 		if ((rack->r_ctl.rc_hpts_flags & PACE_TMR_RACK) ||
6637 		    (IN_RECOVERY(tp->t_flags))) {
6638 			if (rack->r_rr_config != 3)
6639 				tp->t_flags2 |= TF2_DONT_SACK_QUEUE;
6640 			else if (rack->rc_pace_dnd) {
6641 				/*
6642 				 * When DND is on, we only let a sack
6643 				 * interrupt us if we are not in recovery.
6644 				 *
6645 				 * If DND is off, then we never hit here
6646 				 * and let all sacks wake us up.
6647 				 *
6648 				 */
6649 				tp->t_flags2 |= TF2_DONT_SACK_QUEUE;
6650 			}
6651 		}
6652 		if (rack->rc_ack_can_sendout_data) {
6653 			/*
6654 			 * Ahh but wait, this is that special case
6655 			 * where the pacing timer can be disturbed
6656 			 * backout the changes (used for non-paced
6657 			 * burst limiting).
6658 			 */
6659 			tp->t_flags2 &= ~(TF2_DONT_SACK_QUEUE |
6660 			    TF2_MBUF_QUEUE_READY);
6661 		}
6662 		if ((rack->use_rack_rr) &&
6663 		    (rack->r_rr_config < 2) &&
6664 		    ((hpts_timeout) && (hpts_timeout < usecs))) {
6665 			/*
6666 			 * Arrange for the hpts to kick back in after the
6667 			 * t-o if the t-o does not cause a send.
6668 			 */
6669 			tcp_hpts_insert(tp, hpts_timeout, &diag);
6670 			rack_log_hpts_diag(rack, us_cts, &diag, &tv);
6671 			rack_log_to_start(rack, cts, hpts_timeout, usecs, 0);
6672 		} else {
6673 			tcp_hpts_insert(tp, usecs, &diag);
6674 			rack_log_hpts_diag(rack, us_cts, &diag, &tv);
6675 			rack_log_to_start(rack, cts, hpts_timeout, usecs, 1);
6676 		}
6677 	} else if (hpts_timeout) {
6678 		/*
6679 		 * With respect to t_flags2(?) here, lets let any new acks wake
6680 		 * us up here. Since we are not pacing (no pacing timer), output
6681 		 * can happen so we should let it. If its a Rack timer, then any inbound
6682 		 * packet probably won't change the sending (we will be blocked)
6683 		 * but it may change the prr stats so letting it in (the set defaults
6684 		 * at the start of this block) are good enough.
6685 		 */
6686 		rack->r_ctl.rc_hpts_flags &= ~PACE_PKT_OUTPUT;
6687 		tcp_hpts_insert(tp, hpts_timeout, &diag);
6688 		rack_log_hpts_diag(rack, us_cts, &diag, &tv);
6689 		rack_log_to_start(rack, cts, hpts_timeout, usecs, 0);
6690 	} else {
6691 		/* No timer starting */
6692 #ifdef INVARIANTS
6693 		if (SEQ_GT(tp->snd_max, tp->snd_una)) {
6694 			panic("tp:%p rack:%p tlts:%d cts:%u usecs:%u pto:%u -- no timer started?",
6695 			    tp, rack, tot_len_this_send, cts, usecs, hpts_timeout);
6696 		}
6697 #endif
6698 	}
6699 	rack->rc_tmr_stopped = 0;
6700 	if (usecs)
6701 		rack_log_type_bbrsnd(rack, tot_len_this_send, usecs, us_cts, &tv, __LINE__);
6702 }
6703 
6704 static void
6705 rack_mark_lost(struct tcpcb *tp,
6706     struct tcp_rack *rack, struct rack_sendmap *rsm, uint32_t cts)
6707 {
6708 	struct rack_sendmap *nrsm;
6709 	uint32_t thresh,  exp;
6710 
6711 	thresh = rack_calc_thresh_rack(rack, rack_grab_rtt(tp, rack), cts, __LINE__, 0);
6712 	nrsm = rsm;
6713 	TAILQ_FOREACH_FROM(nrsm, &rack->r_ctl.rc_tmap, r_tnext) {
6714 		if ((nrsm->r_flags & RACK_SACK_PASSED) == 0) {
6715 			/* Got up to all that were marked sack-passed */
6716 			break;
6717 		}
6718 		if ((nrsm->r_flags & RACK_WAS_LOST) == 0) {
6719 			exp = ((uint32_t)rsm->r_tim_lastsent[(rsm->r_rtr_cnt - 1)]) + thresh;
6720 			if (TSTMP_LT(exp, cts) || (exp == cts)) {
6721 				/* We now consider it lost */
6722 				nrsm->r_flags |= RACK_WAS_LOST;
6723 				rack->r_ctl.rc_considered_lost += nrsm->r_end - nrsm->r_start;
6724 			} else {
6725 				/* Past here it won't be lost so stop */
6726 				break;
6727 			}
6728 		}
6729 	}
6730 }
6731 
6732 static inline void
6733 rack_mark_nolonger_lost(struct tcp_rack *rack, struct rack_sendmap *rsm)
6734 {
6735 	KASSERT((rack->r_ctl.rc_considered_lost >= (rsm->r_end - rsm->r_start)),
6736 		("rsm:%p rack:%p rc_considered_lost goes negative", rsm,  rack));
6737 	rsm->r_flags &= ~RACK_WAS_LOST;
6738 	if (rack->r_ctl.rc_considered_lost >= (rsm->r_end - rsm->r_start))
6739 		rack->r_ctl.rc_considered_lost -= rsm->r_end - rsm->r_start;
6740 	else
6741 		rack->r_ctl.rc_considered_lost = 0;
6742 }
6743 
6744 /*
6745  * RACK Timer, here we simply do logging and house keeping.
6746  * the normal rack_output() function will call the
6747  * appropriate thing to check if we need to do a RACK retransmit.
6748  * We return 1, saying don't proceed with rack_output only
6749  * when all timers have been stopped (destroyed PCB?).
6750  */
6751 static int
6752 rack_timeout_rack(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cts)
6753 {
6754 	/*
6755 	 * This timer simply provides an internal trigger to send out data.
6756 	 * The check_recovery_mode call will see if there are needed
6757 	 * retransmissions, if so we will enter fast-recovery. The output
6758 	 * call may or may not do the same thing depending on sysctl
6759 	 * settings.
6760 	 */
6761 	struct rack_sendmap *rsm;
6762 
6763 	counter_u64_add(rack_to_tot, 1);
6764 	if (rack->r_state && (rack->r_state != tp->t_state))
6765 		rack_set_state(tp, rack);
6766 	rack->rc_on_min_to = 0;
6767 	rsm = rack_check_recovery_mode(tp, cts);
6768 	rack_log_to_event(rack, RACK_TO_FRM_RACK, rsm);
6769 	if (rsm) {
6770 		/* We need to stroke any lost that are now declared as lost */
6771 		rack_mark_lost(tp, rack, rsm, cts);
6772 		rack->r_ctl.rc_resend = rsm;
6773 		rack->r_timer_override = 1;
6774 		if (rack->use_rack_rr) {
6775 			/*
6776 			 * Don't accumulate extra pacing delay
6777 			 * we are allowing the rack timer to
6778 			 * over-ride pacing i.e. rrr takes precedence
6779 			 * if the pacing interval is longer than the rrr
6780 			 * time (in other words we get the min pacing
6781 			 * time versus rrr pacing time).
6782 			 */
6783 			rack->r_ctl.rc_hpts_flags &= ~PACE_PKT_OUTPUT;
6784 		}
6785 	}
6786 	rack->r_ctl.rc_hpts_flags &= ~PACE_TMR_RACK;
6787 	if (rsm == NULL) {
6788 		/* restart a timer and return 1 */
6789 		rack_start_hpts_timer(rack, tp, cts,
6790 				      0, 0, 0);
6791 		return (1);
6792 	}
6793 	return (0);
6794 }
6795 
6796 
6797 
6798 static void
6799 rack_adjust_orig_mlen(struct rack_sendmap *rsm)
6800 {
6801 
6802 	if ((M_TRAILINGROOM(rsm->m) != rsm->orig_t_space)) {
6803 		/*
6804 		 * The trailing space changed, mbufs can grow
6805 		 * at the tail but they can't shrink from
6806 		 * it, KASSERT that. Adjust the orig_m_len to
6807 		 * compensate for this change.
6808 		 */
6809 		KASSERT((rsm->orig_t_space > M_TRAILINGROOM(rsm->m)),
6810 			("mbuf:%p rsm:%p trailing_space:%jd ots:%u oml:%u mlen:%u\n",
6811 			 rsm->m,
6812 			 rsm,
6813 			 (intmax_t)M_TRAILINGROOM(rsm->m),
6814 			 rsm->orig_t_space,
6815 			 rsm->orig_m_len,
6816 			 rsm->m->m_len));
6817 		rsm->orig_m_len += (rsm->orig_t_space - M_TRAILINGROOM(rsm->m));
6818 		rsm->orig_t_space = M_TRAILINGROOM(rsm->m);
6819 	}
6820 	if (rsm->m->m_len < rsm->orig_m_len) {
6821 		/*
6822 		 * Mbuf shrank, trimmed off the top by an ack, our
6823 		 * offset changes.
6824 		 */
6825 		KASSERT((rsm->soff >= (rsm->orig_m_len - rsm->m->m_len)),
6826 			("mbuf:%p len:%u rsm:%p oml:%u soff:%u\n",
6827 			 rsm->m, rsm->m->m_len,
6828 			 rsm, rsm->orig_m_len,
6829 			 rsm->soff));
6830 		if (rsm->soff >= (rsm->orig_m_len - rsm->m->m_len))
6831 			rsm->soff -= (rsm->orig_m_len - rsm->m->m_len);
6832 		else
6833 			rsm->soff = 0;
6834 		rsm->orig_m_len = rsm->m->m_len;
6835 #ifdef INVARIANTS
6836 	} else if (rsm->m->m_len > rsm->orig_m_len) {
6837 		panic("rsm:%p m:%p m_len grew outside of t_space compensation",
6838 		      rsm, rsm->m);
6839 #endif
6840 	}
6841 }
6842 
6843 static void
6844 rack_setup_offset_for_rsm(struct tcp_rack *rack, struct rack_sendmap *src_rsm, struct rack_sendmap *rsm)
6845 {
6846 	struct mbuf *m;
6847 	uint32_t soff;
6848 
6849 	if (src_rsm->m &&
6850 	    ((src_rsm->orig_m_len != src_rsm->m->m_len) ||
6851 	     (M_TRAILINGROOM(src_rsm->m) != src_rsm->orig_t_space))) {
6852 		/* Fix up the orig_m_len and possibly the mbuf offset */
6853 		rack_adjust_orig_mlen(src_rsm);
6854 	}
6855 	m = src_rsm->m;
6856 	soff = src_rsm->soff + (src_rsm->r_end - src_rsm->r_start);
6857 	while (soff >= m->m_len) {
6858 		/* Move out past this mbuf */
6859 		soff -= m->m_len;
6860 		m = m->m_next;
6861 		KASSERT((m != NULL),
6862 			("rsm:%p nrsm:%p hit at soff:%u null m",
6863 			 src_rsm, rsm, soff));
6864 		if (m == NULL) {
6865 			/* This should *not* happen which is why there is a kassert */
6866 			src_rsm->m = sbsndmbuf(&rack->rc_inp->inp_socket->so_snd,
6867 					       (src_rsm->r_start - rack->rc_tp->snd_una),
6868 					       &src_rsm->soff);
6869 			src_rsm->orig_m_len = src_rsm->m->m_len;
6870 			src_rsm->orig_t_space = M_TRAILINGROOM(src_rsm->m);
6871 			rsm->m = sbsndmbuf(&rack->rc_inp->inp_socket->so_snd,
6872 					   (rsm->r_start - rack->rc_tp->snd_una),
6873 					   &rsm->soff);
6874 			rsm->orig_m_len = rsm->m->m_len;
6875 			rsm->orig_t_space = M_TRAILINGROOM(rsm->m);
6876 			return;
6877 		}
6878 	}
6879 	rsm->m = m;
6880 	rsm->soff = soff;
6881 	rsm->orig_m_len = m->m_len;
6882 	rsm->orig_t_space = M_TRAILINGROOM(rsm->m);
6883 }
6884 
6885 static inline void
6886 rack_clone_rsm(struct tcp_rack *rack, struct rack_sendmap *nrsm,
6887 	       struct rack_sendmap *rsm, uint32_t start)
6888 {
6889 	int idx;
6890 
6891 	nrsm->r_start = start;
6892 	nrsm->r_end = rsm->r_end;
6893 	nrsm->r_rtr_cnt = rsm->r_rtr_cnt;
6894 	nrsm->r_act_rxt_cnt = rsm->r_act_rxt_cnt;
6895 	nrsm->r_flags = rsm->r_flags;
6896 	nrsm->r_dupack = rsm->r_dupack;
6897 	nrsm->r_no_rtt_allowed = rsm->r_no_rtt_allowed;
6898 	nrsm->r_rtr_bytes = 0;
6899 	nrsm->r_fas = rsm->r_fas;
6900 	nrsm->r_bas = rsm->r_bas;
6901 	tqhash_update_end(rack->r_ctl.tqh, rsm, nrsm->r_start);
6902 	nrsm->r_just_ret = rsm->r_just_ret;
6903 	for (idx = 0; idx < nrsm->r_rtr_cnt; idx++) {
6904 		nrsm->r_tim_lastsent[idx] = rsm->r_tim_lastsent[idx];
6905 	}
6906 	/* Now if we have SYN flag we keep it on the left edge */
6907 	if (nrsm->r_flags & RACK_HAS_SYN)
6908 		nrsm->r_flags &= ~RACK_HAS_SYN;
6909 	/* Now if we have a FIN flag we keep it on the right edge */
6910 	if (rsm->r_flags & RACK_HAS_FIN)
6911 		rsm->r_flags &= ~RACK_HAS_FIN;
6912 	/* Push bit must go to the right edge as well */
6913 	if (rsm->r_flags & RACK_HAD_PUSH)
6914 		rsm->r_flags &= ~RACK_HAD_PUSH;
6915 	/* Update the count if app limited */
6916 	if (nrsm->r_flags & RACK_APP_LIMITED)
6917 		rack->r_ctl.rc_app_limited_cnt++;
6918 	/* Clone over the state of the hw_tls flag */
6919 	nrsm->r_hw_tls = rsm->r_hw_tls;
6920 	/*
6921 	 * Now we need to find nrsm's new location in the mbuf chain
6922 	 * we basically calculate a new offset, which is soff +
6923 	 * how much is left in original rsm. Then we walk out the mbuf
6924 	 * chain to find the righ position, it may be the same mbuf
6925 	 * or maybe not.
6926 	 */
6927 	KASSERT(((rsm->m != NULL) ||
6928 		 (rsm->r_flags & (RACK_HAS_SYN|RACK_HAS_FIN))),
6929 		("rsm:%p nrsm:%p rack:%p -- rsm->m is NULL?", rsm, nrsm, rack));
6930 	if (rsm->m)
6931 		rack_setup_offset_for_rsm(rack, rsm, nrsm);
6932 }
6933 
6934 static struct rack_sendmap *
6935 rack_merge_rsm(struct tcp_rack *rack,
6936 	       struct rack_sendmap *l_rsm,
6937 	       struct rack_sendmap *r_rsm)
6938 {
6939 	/*
6940 	 * We are merging two ack'd RSM's,
6941 	 * the l_rsm is on the left (lower seq
6942 	 * values) and the r_rsm is on the right
6943 	 * (higher seq value). The simplest way
6944 	 * to merge these is to move the right
6945 	 * one into the left. I don't think there
6946 	 * is any reason we need to try to find
6947 	 * the oldest (or last oldest retransmitted).
6948 	 */
6949 	rack_log_map_chg(rack->rc_tp, rack, NULL,
6950 			 l_rsm, r_rsm, MAP_MERGE, r_rsm->r_end, __LINE__);
6951 	tqhash_update_end(rack->r_ctl.tqh, l_rsm, r_rsm->r_end);
6952 	if (l_rsm->r_dupack < r_rsm->r_dupack)
6953 		l_rsm->r_dupack = r_rsm->r_dupack;
6954 	if (r_rsm->r_rtr_bytes)
6955 		l_rsm->r_rtr_bytes += r_rsm->r_rtr_bytes;
6956 	if (r_rsm->r_in_tmap) {
6957 		/* This really should not happen */
6958 		TAILQ_REMOVE(&rack->r_ctl.rc_tmap, r_rsm, r_tnext);
6959 		r_rsm->r_in_tmap = 0;
6960 	}
6961 
6962 	/* Now the flags */
6963 	if (r_rsm->r_flags & RACK_HAS_FIN)
6964 		l_rsm->r_flags |= RACK_HAS_FIN;
6965 	if (r_rsm->r_flags & RACK_TLP)
6966 		l_rsm->r_flags |= RACK_TLP;
6967 	if (r_rsm->r_flags & RACK_RWND_COLLAPSED)
6968 		l_rsm->r_flags |= RACK_RWND_COLLAPSED;
6969 	if ((r_rsm->r_flags & RACK_APP_LIMITED) &&
6970 	    ((l_rsm->r_flags & RACK_APP_LIMITED) == 0)) {
6971 		/*
6972 		 * If both are app-limited then let the
6973 		 * free lower the count. If right is app
6974 		 * limited and left is not, transfer.
6975 		 */
6976 		l_rsm->r_flags |= RACK_APP_LIMITED;
6977 		r_rsm->r_flags &= ~RACK_APP_LIMITED;
6978 		if (r_rsm == rack->r_ctl.rc_first_appl)
6979 			rack->r_ctl.rc_first_appl = l_rsm;
6980 	}
6981 	tqhash_remove(rack->r_ctl.tqh, r_rsm, REMOVE_TYPE_MERGE);
6982 	/*
6983 	 * We keep the largest value, which is the newest
6984 	 * send. We do this in case a segment that is
6985 	 * joined together and not part of a GP estimate
6986 	 * later gets expanded into the GP estimate.
6987 	 *
6988 	 * We prohibit the merging of unlike kinds i.e.
6989 	 * all pieces that are in the GP estimate can be
6990 	 * merged and all pieces that are not in a GP estimate
6991 	 * can be merged, but not disimilar pieces. Combine
6992 	 * this with taking the highest here and we should
6993 	 * be ok unless of course the client reneges. Then
6994 	 * all bets are off.
6995 	 */
6996 	if(l_rsm->r_tim_lastsent[(l_rsm->r_rtr_cnt-1)] <
6997 	   r_rsm->r_tim_lastsent[(r_rsm->r_rtr_cnt-1)]) {
6998 		l_rsm->r_tim_lastsent[(l_rsm->r_rtr_cnt-1)] = r_rsm->r_tim_lastsent[(r_rsm->r_rtr_cnt-1)];
6999 	}
7000 	/*
7001 	 * When merging two RSM's we also need to consider the ack time and keep
7002 	 * newest. If the ack gets merged into a measurement then that is the
7003 	 * one we will want to be using.
7004 	 */
7005 	if(l_rsm->r_ack_arrival	 < r_rsm->r_ack_arrival)
7006 		l_rsm->r_ack_arrival = r_rsm->r_ack_arrival;
7007 
7008 	if ((r_rsm->r_limit_type == 0) && (l_rsm->r_limit_type != 0)) {
7009 		/* Transfer the split limit to the map we free */
7010 		r_rsm->r_limit_type = l_rsm->r_limit_type;
7011 		l_rsm->r_limit_type = 0;
7012 	}
7013 	rack_free(rack, r_rsm);
7014 	l_rsm->r_flags |= RACK_MERGED;
7015 	return (l_rsm);
7016 }
7017 
7018 /*
7019  * TLP Timer, here we simply setup what segment we want to
7020  * have the TLP expire on, the normal rack_output() will then
7021  * send it out.
7022  *
7023  * We return 1, saying don't proceed with rack_output only
7024  * when all timers have been stopped (destroyed PCB?).
7025  */
7026 static int
7027 rack_timeout_tlp(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cts, uint8_t *doing_tlp)
7028 {
7029 	/*
7030 	 * Tail Loss Probe.
7031 	 */
7032 	struct rack_sendmap *rsm = NULL;
7033 	int insret __diagused;
7034 	struct socket *so = tptosocket(tp);
7035 	uint32_t amm;
7036 	uint32_t out, avail;
7037 	int collapsed_win = 0;
7038 
7039 	if (TSTMP_LT(cts, rack->r_ctl.rc_timer_exp)) {
7040 		/* Its not time yet */
7041 		return (0);
7042 	}
7043 	if (ctf_progress_timeout_check(tp, true)) {
7044 		rack_log_progress_event(rack, tp, tick, PROGRESS_DROP, __LINE__);
7045 		return (-ETIMEDOUT);	/* tcp_drop() */
7046 	}
7047 	/*
7048 	 * A TLP timer has expired. We have been idle for 2 rtts. So we now
7049 	 * need to figure out how to force a full MSS segment out.
7050 	 */
7051 	rack_log_to_event(rack, RACK_TO_FRM_TLP, NULL);
7052 	rack->r_ctl.retran_during_recovery = 0;
7053 	rack->r_might_revert = 0;
7054 	rack->r_ctl.dsack_byte_cnt = 0;
7055 	counter_u64_add(rack_tlp_tot, 1);
7056 	if (rack->r_state && (rack->r_state != tp->t_state))
7057 		rack_set_state(tp, rack);
7058 	avail = sbavail(&so->so_snd);
7059 	out = tp->snd_max - tp->snd_una;
7060 	if ((out > tp->snd_wnd) || rack->rc_has_collapsed) {
7061 		/* special case, we need a retransmission */
7062 		collapsed_win = 1;
7063 		goto need_retran;
7064 	}
7065 	if (rack->r_ctl.dsack_persist && (rack->r_ctl.rc_tlp_cnt_out >= 1)) {
7066 		rack->r_ctl.dsack_persist--;
7067 		if (rack->r_ctl.num_dsack && (rack->r_ctl.dsack_persist == 0)) {
7068 			rack->r_ctl.num_dsack = 0;
7069 		}
7070 		rack_log_dsack_event(rack, 1, __LINE__, 0, 0);
7071 	}
7072 	if ((tp->t_flags & TF_GPUTINPROG) &&
7073 	    (rack->r_ctl.rc_tlp_cnt_out == 1)) {
7074 		/*
7075 		 * If this is the second in a row
7076 		 * TLP and we are doing a measurement
7077 		 * its time to abandon the measurement.
7078 		 * Something is likely broken on
7079 		 * the clients network and measuring a
7080 		 * broken network does us no good.
7081 		 */
7082 		tp->t_flags &= ~TF_GPUTINPROG;
7083 		rack_log_pacing_delay_calc(rack, (tp->gput_ack - tp->gput_seq) /*flex2*/,
7084 					   rack->r_ctl.rc_gp_srtt /*flex1*/,
7085 					   tp->gput_seq,
7086 					   0, 0, 18, __LINE__, NULL, 0);
7087 	}
7088 	/*
7089 	 * Check our send oldest always settings, and if
7090 	 * there is an oldest to send jump to the need_retran.
7091 	 */
7092 	if (rack_always_send_oldest && (TAILQ_EMPTY(&rack->r_ctl.rc_tmap) == 0))
7093 		goto need_retran;
7094 
7095 	if (avail > out) {
7096 		/* New data is available */
7097 		amm = avail - out;
7098 		if (amm > ctf_fixed_maxseg(tp)) {
7099 			amm = ctf_fixed_maxseg(tp);
7100 			if ((amm + out) > tp->snd_wnd) {
7101 				/* We are rwnd limited */
7102 				goto need_retran;
7103 			}
7104 		} else if (amm < ctf_fixed_maxseg(tp)) {
7105 			/* not enough to fill a MTU */
7106 			goto need_retran;
7107 		}
7108 		if (IN_FASTRECOVERY(tp->t_flags)) {
7109 			/* Unlikely */
7110 			if (rack->rack_no_prr == 0) {
7111 				if (out + amm <= tp->snd_wnd) {
7112 					rack->r_ctl.rc_prr_sndcnt = amm;
7113 					rack->r_ctl.rc_tlp_new_data = amm;
7114 					rack_log_to_prr(rack, 4, 0, __LINE__);
7115 				}
7116 			} else
7117 				goto need_retran;
7118 		} else {
7119 			/* Set the send-new override */
7120 			if (out + amm <= tp->snd_wnd)
7121 				rack->r_ctl.rc_tlp_new_data = amm;
7122 			else
7123 				goto need_retran;
7124 		}
7125 		rack->r_ctl.rc_tlpsend = NULL;
7126 		counter_u64_add(rack_tlp_newdata, 1);
7127 		goto send;
7128 	}
7129 need_retran:
7130 	/*
7131 	 * Ok we need to arrange the last un-acked segment to be re-sent, or
7132 	 * optionally the first un-acked segment.
7133 	 */
7134 	if (collapsed_win == 0) {
7135 		if (rack_always_send_oldest)
7136 			rsm = TAILQ_FIRST(&rack->r_ctl.rc_tmap);
7137 		else {
7138 			rsm = tqhash_max(rack->r_ctl.tqh);
7139 			if (rsm && (rsm->r_flags & (RACK_ACKED | RACK_HAS_FIN))) {
7140 				rsm = rack_find_high_nonack(rack, rsm);
7141 			}
7142 		}
7143 		if (rsm == NULL) {
7144 #ifdef TCP_BLACKBOX
7145 			tcp_log_dump_tp_logbuf(tp, "nada counter trips", M_NOWAIT, true);
7146 #endif
7147 			goto out;
7148 		}
7149 	} else {
7150 		/*
7151 		 * We had a collapsed window, lets find
7152 		 * the point before the collapse.
7153 		 */
7154 		if (SEQ_GT((rack->r_ctl.last_collapse_point - 1), rack->rc_tp->snd_una))
7155 			rsm = tqhash_find(rack->r_ctl.tqh, (rack->r_ctl.last_collapse_point - 1));
7156 		else {
7157 			rsm = tqhash_min(rack->r_ctl.tqh);
7158 		}
7159 		if (rsm == NULL) {
7160 			/* Huh */
7161 			goto out;
7162 		}
7163 	}
7164 	if ((rsm->r_end - rsm->r_start) > ctf_fixed_maxseg(tp)) {
7165 		/*
7166 		 * We need to split this the last segment in two.
7167 		 */
7168 		struct rack_sendmap *nrsm;
7169 
7170 		nrsm = rack_alloc_full_limit(rack);
7171 		if (nrsm == NULL) {
7172 			/*
7173 			 * No memory to split, we will just exit and punt
7174 			 * off to the RXT timer.
7175 			 */
7176 			goto out;
7177 		}
7178 		rack_clone_rsm(rack, nrsm, rsm,
7179 			       (rsm->r_end - ctf_fixed_maxseg(tp)));
7180 		rack_log_map_chg(tp, rack, NULL, rsm, nrsm, MAP_SPLIT, 0, __LINE__);
7181 #ifndef INVARIANTS
7182 		(void)tqhash_insert(rack->r_ctl.tqh, nrsm);
7183 #else
7184 		if ((insret = tqhash_insert(rack->r_ctl.tqh, nrsm)) != 0) {
7185 			panic("Insert in tailq_hash of %p fails ret:%d rack:%p rsm:%p",
7186 			      nrsm, insret, rack, rsm);
7187 		}
7188 #endif
7189 		if (rsm->r_in_tmap) {
7190 			TAILQ_INSERT_AFTER(&rack->r_ctl.rc_tmap, rsm, nrsm, r_tnext);
7191 			nrsm->r_in_tmap = 1;
7192 		}
7193 		rsm = nrsm;
7194 	}
7195 	rack->r_ctl.rc_tlpsend = rsm;
7196 send:
7197 	/* Make sure output path knows we are doing a TLP */
7198 	*doing_tlp = 1;
7199 	rack->r_timer_override = 1;
7200 	rack->r_ctl.rc_hpts_flags &= ~PACE_TMR_TLP;
7201 	return (0);
7202 out:
7203 	rack->r_ctl.rc_hpts_flags &= ~PACE_TMR_TLP;
7204 	return (0);
7205 }
7206 
7207 /*
7208  * Delayed ack Timer, here we simply need to setup the
7209  * ACK_NOW flag and remove the DELACK flag. From there
7210  * the output routine will send the ack out.
7211  *
7212  * We only return 1, saying don't proceed, if all timers
7213  * are stopped (destroyed PCB?).
7214  */
7215 static int
7216 rack_timeout_delack(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cts)
7217 {
7218 
7219 	rack_log_to_event(rack, RACK_TO_FRM_DELACK, NULL);
7220 	tp->t_flags &= ~TF_DELACK;
7221 	tp->t_flags |= TF_ACKNOW;
7222 	KMOD_TCPSTAT_INC(tcps_delack);
7223 	rack->r_ctl.rc_hpts_flags &= ~PACE_TMR_DELACK;
7224 	return (0);
7225 }
7226 
7227 static inline int
7228 rack_send_ack_challange(struct tcp_rack *rack)
7229 {
7230 	struct tcptemp *t_template;
7231 
7232 	t_template = tcpip_maketemplate(rack->rc_inp);
7233 	if (t_template) {
7234 		if (rack->forced_ack == 0) {
7235 			rack->forced_ack = 1;
7236 			rack->r_ctl.forced_ack_ts = tcp_get_usecs(NULL);
7237 		} else {
7238 			rack->probe_not_answered = 1;
7239 		}
7240 		tcp_respond(rack->rc_tp, t_template->tt_ipgen,
7241 			    &t_template->tt_t, (struct mbuf *)NULL,
7242 			    rack->rc_tp->rcv_nxt, rack->rc_tp->snd_una - 1, 0);
7243 		free(t_template, M_TEMP);
7244 		/* This does send an ack so kill any D-ack timer */
7245 		if (rack->rc_tp->t_flags & TF_DELACK)
7246 			rack->rc_tp->t_flags &= ~TF_DELACK;
7247 		return(1);
7248 	} else
7249 		return (0);
7250 
7251 }
7252 
7253 /*
7254  * Persists timer, here we simply send the
7255  * same thing as a keepalive will.
7256  * the one byte send.
7257  *
7258  * We only return 1, saying don't proceed, if all timers
7259  * are stopped (destroyed PCB?).
7260  */
7261 static int
7262 rack_timeout_persist(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cts)
7263 {
7264 	int32_t retval = 1;
7265 
7266 	if (rack->rc_in_persist == 0)
7267 		return (0);
7268 	if (ctf_progress_timeout_check(tp, false)) {
7269 		tcp_log_end_status(tp, TCP_EI_STATUS_PERSIST_MAX);
7270 		rack_log_progress_event(rack, tp, tick, PROGRESS_DROP, __LINE__);
7271 		counter_u64_add(rack_persists_lost_ends, rack->r_ctl.persist_lost_ends);
7272 		return (-ETIMEDOUT);	/* tcp_drop() */
7273 	}
7274 	/*
7275 	 * Persistence timer into zero window. Force a byte to be output, if
7276 	 * possible.
7277 	 */
7278 	KMOD_TCPSTAT_INC(tcps_persisttimeo);
7279 	/*
7280 	 * Hack: if the peer is dead/unreachable, we do not time out if the
7281 	 * window is closed.  After a full backoff, drop the connection if
7282 	 * the idle time (no responses to probes) reaches the maximum
7283 	 * backoff that we would use if retransmitting.
7284 	 */
7285 	if (tp->t_rxtshift >= V_tcp_retries &&
7286 	    (ticks - tp->t_rcvtime >= tcp_maxpersistidle ||
7287 	     TICKS_2_USEC(ticks - tp->t_rcvtime) >= RACK_REXMTVAL(tp) * tcp_totbackoff)) {
7288 		KMOD_TCPSTAT_INC(tcps_persistdrop);
7289 		tcp_log_end_status(tp, TCP_EI_STATUS_PERSIST_MAX);
7290 		counter_u64_add(rack_persists_lost_ends, rack->r_ctl.persist_lost_ends);
7291 		retval = -ETIMEDOUT;	/* tcp_drop() */
7292 		goto out;
7293 	}
7294 	if ((sbavail(&rack->rc_inp->inp_socket->so_snd) == 0) &&
7295 	    tp->snd_una == tp->snd_max)
7296 		rack_exit_persist(tp, rack, cts);
7297 	rack->r_ctl.rc_hpts_flags &= ~PACE_TMR_PERSIT;
7298 	/*
7299 	 * If the user has closed the socket then drop a persisting
7300 	 * connection after a much reduced timeout.
7301 	 */
7302 	if (tp->t_state > TCPS_CLOSE_WAIT &&
7303 	    (ticks - tp->t_rcvtime) >= TCPTV_PERSMAX) {
7304 		KMOD_TCPSTAT_INC(tcps_persistdrop);
7305 		tcp_log_end_status(tp, TCP_EI_STATUS_PERSIST_MAX);
7306 		counter_u64_add(rack_persists_lost_ends, rack->r_ctl.persist_lost_ends);
7307 		retval = -ETIMEDOUT;	/* tcp_drop() */
7308 		goto out;
7309 	}
7310 	if (rack_send_ack_challange(rack)) {
7311 		/* only set it if we were answered */
7312 		if (rack->probe_not_answered) {
7313 			counter_u64_add(rack_persists_loss, 1);
7314 			rack->r_ctl.persist_lost_ends++;
7315 		}
7316 		counter_u64_add(rack_persists_sends, 1);
7317 		counter_u64_add(rack_out_size[TCP_MSS_ACCT_PERSIST], 1);
7318 	}
7319 	if (tp->t_rxtshift < V_tcp_retries)
7320 		tp->t_rxtshift++;
7321 out:
7322 	rack_log_to_event(rack, RACK_TO_FRM_PERSIST, NULL);
7323 	rack_start_hpts_timer(rack, tp, cts,
7324 			      0, 0, 0);
7325 	return (retval);
7326 }
7327 
7328 /*
7329  * If a keepalive goes off, we had no other timers
7330  * happening. We always return 1 here since this
7331  * routine either drops the connection or sends
7332  * out a segment with respond.
7333  */
7334 static int
7335 rack_timeout_keepalive(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cts)
7336 {
7337 	struct inpcb *inp = tptoinpcb(tp);
7338 
7339 	rack->r_ctl.rc_hpts_flags &= ~PACE_TMR_KEEP;
7340 	rack_log_to_event(rack, RACK_TO_FRM_KEEP, NULL);
7341 	/*
7342 	 * Keep-alive timer went off; send something or drop connection if
7343 	 * idle for too long.
7344 	 */
7345 	KMOD_TCPSTAT_INC(tcps_keeptimeo);
7346 	if (tp->t_state < TCPS_ESTABLISHED)
7347 		goto dropit;
7348 	if ((V_tcp_always_keepalive || inp->inp_socket->so_options & SO_KEEPALIVE) &&
7349 	    tp->t_state <= TCPS_CLOSING) {
7350 		if (ticks - tp->t_rcvtime >= TP_KEEPIDLE(tp) + TP_MAXIDLE(tp))
7351 			goto dropit;
7352 		/*
7353 		 * Send a packet designed to force a response if the peer is
7354 		 * up and reachable: either an ACK if the connection is
7355 		 * still alive, or an RST if the peer has closed the
7356 		 * connection due to timeout or reboot. Using sequence
7357 		 * number tp->snd_una-1 causes the transmitted zero-length
7358 		 * segment to lie outside the receive window; by the
7359 		 * protocol spec, this requires the correspondent TCP to
7360 		 * respond.
7361 		 */
7362 		KMOD_TCPSTAT_INC(tcps_keepprobe);
7363 		rack_send_ack_challange(rack);
7364 	}
7365 	rack_start_hpts_timer(rack, tp, cts, 0, 0, 0);
7366 	return (1);
7367 dropit:
7368 	KMOD_TCPSTAT_INC(tcps_keepdrops);
7369 	tcp_log_end_status(tp, TCP_EI_STATUS_KEEP_MAX);
7370 	return (-ETIMEDOUT);	/* tcp_drop() */
7371 }
7372 
7373 /*
7374  * Retransmit helper function, clear up all the ack
7375  * flags and take care of important book keeping.
7376  */
7377 static void
7378 rack_remxt_tmr(struct tcpcb *tp)
7379 {
7380 	/*
7381 	 * The retransmit timer went off, all sack'd blocks must be
7382 	 * un-acked.
7383 	 */
7384 	struct rack_sendmap *rsm, *trsm = NULL;
7385 	struct tcp_rack *rack;
7386 
7387 	rack = (struct tcp_rack *)tp->t_fb_ptr;
7388 	rack_timer_cancel(tp, rack, tcp_get_usecs(NULL), __LINE__);
7389 	rack_log_to_event(rack, RACK_TO_FRM_TMR, NULL);
7390 	rack->r_timer_override = 1;
7391 	rack->r_ctl.rc_snd_max_at_rto = tp->snd_max;
7392 	rack->r_ctl.rc_last_timeout_snduna = tp->snd_una;
7393 	rack->r_late = 0;
7394 	rack->r_early = 0;
7395 	rack->r_ctl.rc_agg_delayed = 0;
7396 	rack->r_ctl.rc_agg_early = 0;
7397 	if (rack->r_state && (rack->r_state != tp->t_state))
7398 		rack_set_state(tp, rack);
7399 	if (tp->t_rxtshift <= rack_rxt_scoreboard_clear_thresh) {
7400 		/*
7401 		 * We do not clear the scoreboard until we have had
7402 		 * more than rack_rxt_scoreboard_clear_thresh time-outs.
7403 		 */
7404 		rack->r_ctl.rc_resend = TAILQ_FIRST(&rack->r_ctl.rc_tmap);
7405 		if (rack->r_ctl.rc_resend != NULL)
7406 			rack->r_ctl.rc_resend->r_flags |= RACK_TO_REXT;
7407 
7408 		return;
7409 	}
7410 	/*
7411 	 * Ideally we would like to be able to
7412 	 * mark SACK-PASS on anything not acked here.
7413 	 *
7414 	 * However, if we do that we would burst out
7415 	 * all that data 1ms apart. This would be unwise,
7416 	 * so for now we will just let the normal rxt timer
7417 	 * and tlp timer take care of it.
7418 	 *
7419 	 * Also we really need to stick them back in sequence
7420 	 * order. This way we send in the proper order and any
7421 	 * sacks that come floating in will "re-ack" the data.
7422 	 * To do this we zap the tmap with an INIT and then
7423 	 * walk through and place every rsm in the tail queue
7424 	 * hash table back in its seq ordered place.
7425 	 */
7426 	TAILQ_INIT(&rack->r_ctl.rc_tmap);
7427 
7428 	rack->r_ctl.recovery_rxt_cnt = 0;
7429 	TQHASH_FOREACH(rsm, rack->r_ctl.tqh)  {
7430 		rsm->r_dupack = 0;
7431 		if (rack_verbose_logging)
7432 			rack_log_retran_reason(rack, rsm, __LINE__, 0, 2);
7433 		/* We must re-add it back to the tlist */
7434 		if (trsm == NULL) {
7435 			TAILQ_INSERT_HEAD(&rack->r_ctl.rc_tmap, rsm, r_tnext);
7436 		} else {
7437 			TAILQ_INSERT_AFTER(&rack->r_ctl.rc_tmap, trsm, rsm, r_tnext);
7438 		}
7439 		rsm->r_in_tmap = 1;
7440 		trsm = rsm;
7441 		if (rsm->r_flags & RACK_ACKED)
7442 			rsm->r_flags |= RACK_WAS_ACKED;
7443 		rsm->r_flags &= ~(RACK_ACKED | RACK_SACK_PASSED | RACK_WAS_SACKPASS | RACK_RWND_COLLAPSED | RACK_WAS_LOST);
7444 		rsm->r_flags |= RACK_MUST_RXT;
7445 	}
7446 	/* zero the lost since it's all gone */
7447 	rack->r_ctl.rc_considered_lost = 0;
7448 	/* Clear the count (we just un-acked them) */
7449 	rack->r_ctl.rc_sacked = 0;
7450 	rack->r_ctl.rc_sacklast = NULL;
7451 	/* Clear the tlp rtx mark */
7452 	rack->r_ctl.rc_resend = tqhash_min(rack->r_ctl.tqh);
7453 	if (rack->r_ctl.rc_resend != NULL)
7454 		rack->r_ctl.rc_resend->r_flags |= RACK_TO_REXT;
7455 	rack->r_ctl.rc_prr_sndcnt = 0;
7456 	rack_log_to_prr(rack, 6, 0, __LINE__);
7457 	rack->r_ctl.rc_resend = tqhash_min(rack->r_ctl.tqh);
7458 	if (rack->r_ctl.rc_resend != NULL)
7459 		rack->r_ctl.rc_resend->r_flags |= RACK_TO_REXT;
7460 	if (((tp->t_flags & TF_SACK_PERMIT) == 0) &&
7461 	    ((tp->t_flags & TF_SENTFIN) == 0)) {
7462 		/*
7463 		 * For non-sack customers new data
7464 		 * needs to go out as retransmits until
7465 		 * we retransmit up to snd_max.
7466 		 */
7467 		rack->r_must_retran = 1;
7468 		rack->r_ctl.rc_out_at_rto = ctf_flight_size(rack->rc_tp,
7469 							    rack->r_ctl.rc_sacked);
7470 	}
7471 }
7472 
7473 static void
7474 rack_convert_rtts(struct tcpcb *tp)
7475 {
7476 	tcp_change_time_units(tp, TCP_TMR_GRANULARITY_USEC);
7477 	tp->t_rxtcur = RACK_REXMTVAL(tp);
7478 	if (TCPS_HAVEESTABLISHED(tp->t_state)) {
7479 		tp->t_rxtcur += TICKS_2_USEC(tcp_rexmit_slop);
7480 	}
7481 	if (tp->t_rxtcur > rack_rto_max) {
7482 		tp->t_rxtcur = rack_rto_max;
7483 	}
7484 }
7485 
7486 static void
7487 rack_cc_conn_init(struct tcpcb *tp)
7488 {
7489 	struct tcp_rack *rack;
7490 	uint32_t srtt;
7491 
7492 	rack = (struct tcp_rack *)tp->t_fb_ptr;
7493 	srtt = tp->t_srtt;
7494 	cc_conn_init(tp);
7495 	/*
7496 	 * Now convert to rack's internal format,
7497 	 * if required.
7498 	 */
7499 	if ((srtt == 0) && (tp->t_srtt != 0))
7500 		rack_convert_rtts(tp);
7501 	/*
7502 	 * We want a chance to stay in slowstart as
7503 	 * we create a connection. TCP spec says that
7504 	 * initially ssthresh is infinite. For our
7505 	 * purposes that is the snd_wnd.
7506 	 */
7507 	if (tp->snd_ssthresh < tp->snd_wnd) {
7508 		tp->snd_ssthresh = tp->snd_wnd;
7509 	}
7510 	/*
7511 	 * We also want to assure a IW worth of
7512 	 * data can get inflight.
7513 	 */
7514 	if (rc_init_window(rack) < tp->snd_cwnd)
7515 		tp->snd_cwnd = rc_init_window(rack);
7516 }
7517 
7518 /*
7519  * Re-transmit timeout! If we drop the PCB we will return 1, otherwise
7520  * we will setup to retransmit the lowest seq number outstanding.
7521  */
7522 static int
7523 rack_timeout_rxt(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cts)
7524 {
7525 	struct inpcb *inp = tptoinpcb(tp);
7526 	int32_t rexmt;
7527 	int32_t retval = 0;
7528 	bool isipv6;
7529 
7530 	if ((tp->t_flags & TF_GPUTINPROG) &&
7531 	    (tp->t_rxtshift)) {
7532 		/*
7533 		 * We have had a second timeout
7534 		 * measurements on successive rxt's are not profitable.
7535 		 * It is unlikely to be of any use (the network is
7536 		 * broken or the client went away).
7537 		 */
7538 		tp->t_flags &= ~TF_GPUTINPROG;
7539 		rack_log_pacing_delay_calc(rack, (tp->gput_ack - tp->gput_seq) /*flex2*/,
7540 					   rack->r_ctl.rc_gp_srtt /*flex1*/,
7541 					   tp->gput_seq,
7542 					   0, 0, 18, __LINE__, NULL, 0);
7543 	}
7544 	if (ctf_progress_timeout_check(tp, false)) {
7545 		tcp_log_end_status(tp, TCP_EI_STATUS_RETRAN);
7546 		rack_log_progress_event(rack, tp, tick, PROGRESS_DROP, __LINE__);
7547 		return (-ETIMEDOUT);	/* tcp_drop() */
7548 	}
7549 	rack->r_ctl.rc_hpts_flags &= ~PACE_TMR_RXT;
7550 	rack->r_ctl.retran_during_recovery = 0;
7551 	rack->rc_ack_required = 1;
7552 	rack->r_ctl.dsack_byte_cnt = 0;
7553 	if (IN_RECOVERY(tp->t_flags) &&
7554 	    (rack->rto_from_rec == 0)) {
7555 		/*
7556 		 * Mark that we had a rto while in recovery
7557 		 * and save the ssthresh so if we go back
7558 		 * into recovery we will have a chance
7559 		 * to slowstart back to the level.
7560 		 */
7561 		rack->rto_from_rec = 1;
7562 		rack->r_ctl.rto_ssthresh = tp->snd_ssthresh;
7563 	}
7564 	if (IN_FASTRECOVERY(tp->t_flags))
7565 		tp->t_flags |= TF_WASFRECOVERY;
7566 	else
7567 		tp->t_flags &= ~TF_WASFRECOVERY;
7568 	if (IN_CONGRECOVERY(tp->t_flags))
7569 		tp->t_flags |= TF_WASCRECOVERY;
7570 	else
7571 		tp->t_flags &= ~TF_WASCRECOVERY;
7572 	if (TCPS_HAVEESTABLISHED(tp->t_state) &&
7573 	    (tp->snd_una == tp->snd_max)) {
7574 		/* Nothing outstanding .. nothing to do */
7575 		return (0);
7576 	}
7577 	if (rack->r_ctl.dsack_persist) {
7578 		rack->r_ctl.dsack_persist--;
7579 		if (rack->r_ctl.num_dsack && (rack->r_ctl.dsack_persist == 0)) {
7580 			rack->r_ctl.num_dsack = 0;
7581 		}
7582 		rack_log_dsack_event(rack, 1, __LINE__, 0, 0);
7583 	}
7584 	/*
7585 	 * Rack can only run one timer  at a time, so we cannot
7586 	 * run a KEEPINIT (gating SYN sending) and a retransmit
7587 	 * timer for the SYN. So if we are in a front state and
7588 	 * have a KEEPINIT timer we need to check the first transmit
7589 	 * against now to see if we have exceeded the KEEPINIT time
7590 	 * (if one is set).
7591 	 */
7592 	if ((TCPS_HAVEESTABLISHED(tp->t_state) == 0) &&
7593 	    (TP_KEEPINIT(tp) != 0)) {
7594 		struct rack_sendmap *rsm;
7595 
7596 		rsm = tqhash_min(rack->r_ctl.tqh);
7597 		if (rsm) {
7598 			/* Ok we have something outstanding to test keepinit with */
7599 			if ((TSTMP_GT(cts, (uint32_t)rsm->r_tim_lastsent[0])) &&
7600 			    ((cts - (uint32_t)rsm->r_tim_lastsent[0]) >= TICKS_2_USEC(TP_KEEPINIT(tp)))) {
7601 				/* We have exceeded the KEEPINIT time */
7602 				tcp_log_end_status(tp, TCP_EI_STATUS_KEEP_MAX);
7603 				goto drop_it;
7604 			}
7605 		}
7606 	}
7607 	/*
7608 	 * Retransmission timer went off.  Message has not been acked within
7609 	 * retransmit interval.  Back off to a longer retransmit interval
7610 	 * and retransmit one segment.
7611 	 */
7612 	if ((rack->r_ctl.rc_resend == NULL) ||
7613 	    ((rack->r_ctl.rc_resend->r_flags & RACK_RWND_COLLAPSED) == 0)) {
7614 		/*
7615 		 * If the rwnd collapsed on
7616 		 * the one we are retransmitting
7617 		 * it does not count against the
7618 		 * rxt count.
7619 		 */
7620 		tp->t_rxtshift++;
7621 	}
7622 	rack_remxt_tmr(tp);
7623 	if (tp->t_rxtshift > V_tcp_retries) {
7624 		tcp_log_end_status(tp, TCP_EI_STATUS_RETRAN);
7625 drop_it:
7626 		tp->t_rxtshift = V_tcp_retries;
7627 		KMOD_TCPSTAT_INC(tcps_timeoutdrop);
7628 		/* XXXGL: previously t_softerror was casted to uint16_t */
7629 		MPASS(tp->t_softerror >= 0);
7630 		retval = tp->t_softerror ? -tp->t_softerror : -ETIMEDOUT;
7631 		goto out;	/* tcp_drop() */
7632 	}
7633 	if (tp->t_state == TCPS_SYN_SENT) {
7634 		/*
7635 		 * If the SYN was retransmitted, indicate CWND to be limited
7636 		 * to 1 segment in cc_conn_init().
7637 		 */
7638 		tp->snd_cwnd = 1;
7639 	} else if (tp->t_rxtshift == 1) {
7640 		/*
7641 		 * first retransmit; record ssthresh and cwnd so they can be
7642 		 * recovered if this turns out to be a "bad" retransmit. A
7643 		 * retransmit is considered "bad" if an ACK for this segment
7644 		 * is received within RTT/2 interval; the assumption here is
7645 		 * that the ACK was already in flight.  See "On Estimating
7646 		 * End-to-End Network Path Properties" by Allman and Paxson
7647 		 * for more details.
7648 		 */
7649 		tp->snd_cwnd_prev = tp->snd_cwnd;
7650 		tp->snd_ssthresh_prev = tp->snd_ssthresh;
7651 		tp->snd_recover_prev = tp->snd_recover;
7652 		tp->t_badrxtwin = ticks + (USEC_2_TICKS(tp->t_srtt)/2);
7653 		tp->t_flags |= TF_PREVVALID;
7654 	} else if ((tp->t_flags & TF_RCVD_TSTMP) == 0)
7655 		tp->t_flags &= ~TF_PREVVALID;
7656 	KMOD_TCPSTAT_INC(tcps_rexmttimeo);
7657 	if ((tp->t_state == TCPS_SYN_SENT) ||
7658 	    (tp->t_state == TCPS_SYN_RECEIVED))
7659 		rexmt = RACK_INITIAL_RTO * tcp_backoff[tp->t_rxtshift];
7660 	else
7661 		rexmt = max(rack_rto_min, (tp->t_srtt + (tp->t_rttvar << 2))) * tcp_backoff[tp->t_rxtshift];
7662 
7663 	RACK_TCPT_RANGESET(tp->t_rxtcur, rexmt,
7664 	   max(rack_rto_min, rexmt), rack_rto_max, rack->r_ctl.timer_slop);
7665 	/*
7666 	 * We enter the path for PLMTUD if connection is established or, if
7667 	 * connection is FIN_WAIT_1 status, reason for the last is that if
7668 	 * amount of data we send is very small, we could send it in couple
7669 	 * of packets and process straight to FIN. In that case we won't
7670 	 * catch ESTABLISHED state.
7671 	 */
7672 #ifdef INET6
7673 	isipv6 = (inp->inp_vflag & INP_IPV6) ? true : false;
7674 #else
7675 	isipv6 = false;
7676 #endif
7677 	if (((V_tcp_pmtud_blackhole_detect == 1) ||
7678 	    (V_tcp_pmtud_blackhole_detect == 2 && !isipv6) ||
7679 	    (V_tcp_pmtud_blackhole_detect == 3 && isipv6)) &&
7680 	    ((tp->t_state == TCPS_ESTABLISHED) ||
7681 	    (tp->t_state == TCPS_FIN_WAIT_1))) {
7682 		/*
7683 		 * Idea here is that at each stage of mtu probe (usually,
7684 		 * 1448 -> 1188 -> 524) should be given 2 chances to recover
7685 		 * before further clamping down. 'tp->t_rxtshift % 2 == 0'
7686 		 * should take care of that.
7687 		 */
7688 		if (((tp->t_flags2 & (TF2_PLPMTU_PMTUD | TF2_PLPMTU_MAXSEGSNT)) ==
7689 		    (TF2_PLPMTU_PMTUD | TF2_PLPMTU_MAXSEGSNT)) &&
7690 		    (tp->t_rxtshift >= 2 && tp->t_rxtshift < 6 &&
7691 		    tp->t_rxtshift % 2 == 0)) {
7692 			/*
7693 			 * Enter Path MTU Black-hole Detection mechanism: -
7694 			 * Disable Path MTU Discovery (IP "DF" bit). -
7695 			 * Reduce MTU to lower value than what we negotiated
7696 			 * with peer.
7697 			 */
7698 			if ((tp->t_flags2 & TF2_PLPMTU_BLACKHOLE) == 0) {
7699 				/* Record that we may have found a black hole. */
7700 				tp->t_flags2 |= TF2_PLPMTU_BLACKHOLE;
7701 				/* Keep track of previous MSS. */
7702 				tp->t_pmtud_saved_maxseg = tp->t_maxseg;
7703 			}
7704 
7705 			/*
7706 			 * Reduce the MSS to blackhole value or to the
7707 			 * default in an attempt to retransmit.
7708 			 */
7709 #ifdef INET6
7710 			if (isipv6 &&
7711 			    tp->t_maxseg > V_tcp_v6pmtud_blackhole_mss) {
7712 				/* Use the sysctl tuneable blackhole MSS. */
7713 				tp->t_maxseg = V_tcp_v6pmtud_blackhole_mss;
7714 				KMOD_TCPSTAT_INC(tcps_pmtud_blackhole_activated);
7715 			} else if (isipv6) {
7716 				/* Use the default MSS. */
7717 				tp->t_maxseg = V_tcp_v6mssdflt;
7718 				/*
7719 				 * Disable Path MTU Discovery when we switch
7720 				 * to minmss.
7721 				 */
7722 				tp->t_flags2 &= ~TF2_PLPMTU_PMTUD;
7723 				KMOD_TCPSTAT_INC(tcps_pmtud_blackhole_activated_min_mss);
7724 			}
7725 #endif
7726 #if defined(INET6) && defined(INET)
7727 			else
7728 #endif
7729 #ifdef INET
7730 			if (tp->t_maxseg > V_tcp_pmtud_blackhole_mss) {
7731 				/* Use the sysctl tuneable blackhole MSS. */
7732 				tp->t_maxseg = V_tcp_pmtud_blackhole_mss;
7733 				KMOD_TCPSTAT_INC(tcps_pmtud_blackhole_activated);
7734 			} else {
7735 				/* Use the default MSS. */
7736 				tp->t_maxseg = V_tcp_mssdflt;
7737 				/*
7738 				 * Disable Path MTU Discovery when we switch
7739 				 * to minmss.
7740 				 */
7741 				tp->t_flags2 &= ~TF2_PLPMTU_PMTUD;
7742 				KMOD_TCPSTAT_INC(tcps_pmtud_blackhole_activated_min_mss);
7743 			}
7744 #endif
7745 		} else {
7746 			/*
7747 			 * If further retransmissions are still unsuccessful
7748 			 * with a lowered MTU, maybe this isn't a blackhole
7749 			 * and we restore the previous MSS and blackhole
7750 			 * detection flags. The limit '6' is determined by
7751 			 * giving each probe stage (1448, 1188, 524) 2
7752 			 * chances to recover.
7753 			 */
7754 			if ((tp->t_flags2 & TF2_PLPMTU_BLACKHOLE) &&
7755 			    (tp->t_rxtshift >= 6)) {
7756 				tp->t_flags2 |= TF2_PLPMTU_PMTUD;
7757 				tp->t_flags2 &= ~TF2_PLPMTU_BLACKHOLE;
7758 				tp->t_maxseg = tp->t_pmtud_saved_maxseg;
7759 				if (tp->t_maxseg < V_tcp_mssdflt) {
7760 					/*
7761 					 * The MSS is so small we should not
7762 					 * process incoming SACK's since we are
7763 					 * subject to attack in such a case.
7764 					 */
7765 					tp->t_flags2 |= TF2_PROC_SACK_PROHIBIT;
7766 				} else {
7767 					tp->t_flags2 &= ~TF2_PROC_SACK_PROHIBIT;
7768 				}
7769 				KMOD_TCPSTAT_INC(tcps_pmtud_blackhole_failed);
7770 			}
7771 		}
7772 	}
7773 	/*
7774 	 * Disable RFC1323 and SACK if we haven't got any response to
7775 	 * our third SYN to work-around some broken terminal servers
7776 	 * (most of which have hopefully been retired) that have bad VJ
7777 	 * header compression code which trashes TCP segments containing
7778 	 * unknown-to-them TCP options.
7779 	 */
7780 	if (tcp_rexmit_drop_options && (tp->t_state == TCPS_SYN_SENT) &&
7781 	    (tp->t_rxtshift == 3))
7782 		tp->t_flags &= ~(TF_REQ_SCALE|TF_REQ_TSTMP|TF_SACK_PERMIT);
7783 	/*
7784 	 * If we backed off this far, our srtt estimate is probably bogus.
7785 	 * Clobber it so we'll take the next rtt measurement as our srtt;
7786 	 * move the current srtt into rttvar to keep the current retransmit
7787 	 * times until then.
7788 	 */
7789 	if (tp->t_rxtshift > TCP_MAXRXTSHIFT / 4) {
7790 #ifdef INET6
7791 		if ((inp->inp_vflag & INP_IPV6) != 0)
7792 			in6_losing(inp);
7793 		else
7794 #endif
7795 			in_losing(inp);
7796 		tp->t_rttvar += tp->t_srtt;
7797 		tp->t_srtt = 0;
7798 	}
7799 	sack_filter_clear(&rack->r_ctl.rack_sf, tp->snd_una);
7800 	tp->snd_recover = tp->snd_max;
7801 	tp->t_flags |= TF_ACKNOW;
7802 	tp->t_rtttime = 0;
7803 	rack_cong_signal(tp, CC_RTO, tp->snd_una, __LINE__);
7804 out:
7805 	return (retval);
7806 }
7807 
7808 static int
7809 rack_process_timers(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cts, uint8_t hpts_calling, uint8_t *doing_tlp)
7810 {
7811 	int32_t ret = 0;
7812 	int32_t timers = (rack->r_ctl.rc_hpts_flags & PACE_TMR_MASK);
7813 
7814 	if ((tp->t_state >= TCPS_FIN_WAIT_1) &&
7815 	    (tp->t_flags & TF_GPUTINPROG)) {
7816 		/*
7817 		 * We have a goodput in progress
7818 		 * and we have entered a late state.
7819 		 * Do we have enough data in the sb
7820 		 * to handle the GPUT request?
7821 		 */
7822 		uint32_t bytes;
7823 
7824 		bytes = tp->gput_ack - tp->gput_seq;
7825 		if (SEQ_GT(tp->gput_seq, tp->snd_una))
7826 			bytes += tp->gput_seq - tp->snd_una;
7827 		if (bytes > sbavail(&tptosocket(tp)->so_snd)) {
7828 			/*
7829 			 * There are not enough bytes in the socket
7830 			 * buffer that have been sent to cover this
7831 			 * measurement. Cancel it.
7832 			 */
7833 			rack_log_pacing_delay_calc(rack, (tp->gput_ack - tp->gput_seq) /*flex2*/,
7834 						   rack->r_ctl.rc_gp_srtt /*flex1*/,
7835 						   tp->gput_seq,
7836 						   0, 0, 18, __LINE__, NULL, 0);
7837 			tp->t_flags &= ~TF_GPUTINPROG;
7838 		}
7839 	}
7840 	if (timers == 0) {
7841 		return (0);
7842 	}
7843 	if (tp->t_state == TCPS_LISTEN) {
7844 		/* no timers on listen sockets */
7845 		if (rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT)
7846 			return (0);
7847 		return (1);
7848 	}
7849 	if ((timers & PACE_TMR_RACK) &&
7850 	    rack->rc_on_min_to) {
7851 		/*
7852 		 * For the rack timer when we
7853 		 * are on a min-timeout (which means rrr_conf = 3)
7854 		 * we don't want to check the timer. It may
7855 		 * be going off for a pace and thats ok we
7856 		 * want to send the retransmit (if its ready).
7857 		 *
7858 		 * If its on a normal rack timer (non-min) then
7859 		 * we will check if its expired.
7860 		 */
7861 		goto skip_time_check;
7862 	}
7863 	if (TSTMP_LT(cts, rack->r_ctl.rc_timer_exp)) {
7864 		uint32_t left;
7865 
7866 		if (rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT) {
7867 			ret = -1;
7868 			rack_log_to_processing(rack, cts, ret, 0);
7869 			return (0);
7870 		}
7871 		if (hpts_calling == 0) {
7872 			/*
7873 			 * A user send or queued mbuf (sack) has called us? We
7874 			 * return 0 and let the pacing guards
7875 			 * deal with it if they should or
7876 			 * should not cause a send.
7877 			 */
7878 			ret = -2;
7879 			rack_log_to_processing(rack, cts, ret, 0);
7880 			return (0);
7881 		}
7882 		/*
7883 		 * Ok our timer went off early and we are not paced false
7884 		 * alarm, go back to sleep. We make sure we don't have
7885 		 * no-sack wakeup on since we no longer have a PKT_OUTPUT
7886 		 * flag in place.
7887 		 */
7888 		rack->rc_tp->t_flags2 &= ~TF2_DONT_SACK_QUEUE;
7889 		ret = -3;
7890 		left = rack->r_ctl.rc_timer_exp - cts;
7891 		tcp_hpts_insert(tp, left, NULL);
7892 		rack_log_to_processing(rack, cts, ret, left);
7893 		return (1);
7894 	}
7895 skip_time_check:
7896 	rack->rc_tmr_stopped = 0;
7897 	rack->r_ctl.rc_hpts_flags &= ~PACE_TMR_MASK;
7898 	if (timers & PACE_TMR_DELACK) {
7899 		ret = rack_timeout_delack(tp, rack, cts);
7900 	} else if (timers & PACE_TMR_RACK) {
7901 		rack->r_ctl.rc_tlp_rxt_last_time = cts;
7902 		rack->r_fast_output = 0;
7903 		ret = rack_timeout_rack(tp, rack, cts);
7904 	} else if (timers & PACE_TMR_TLP) {
7905 		rack->r_ctl.rc_tlp_rxt_last_time = cts;
7906 		rack->r_fast_output = 0;
7907 		ret = rack_timeout_tlp(tp, rack, cts, doing_tlp);
7908 	} else if (timers & PACE_TMR_RXT) {
7909 		rack->r_ctl.rc_tlp_rxt_last_time = cts;
7910 		rack->r_fast_output = 0;
7911 		ret = rack_timeout_rxt(tp, rack, cts);
7912 	} else if (timers & PACE_TMR_PERSIT) {
7913 		ret = rack_timeout_persist(tp, rack, cts);
7914 	} else if (timers & PACE_TMR_KEEP) {
7915 		ret = rack_timeout_keepalive(tp, rack, cts);
7916 	}
7917 	rack_log_to_processing(rack, cts, ret, timers);
7918 	return (ret);
7919 }
7920 
7921 static void
7922 rack_timer_cancel(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cts, int line)
7923 {
7924 	struct timeval tv;
7925 	uint32_t us_cts, flags_on_entry;
7926 	uint8_t hpts_removed = 0;
7927 
7928 	flags_on_entry = rack->r_ctl.rc_hpts_flags;
7929 	us_cts = tcp_get_usecs(&tv);
7930 	if ((rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT) &&
7931 	    ((TSTMP_GEQ(us_cts, rack->r_ctl.rc_last_output_to)) ||
7932 	     ((tp->snd_max - tp->snd_una) == 0))) {
7933 		tcp_hpts_remove(rack->rc_tp);
7934 		hpts_removed = 1;
7935 		/* If we were not delayed cancel out the flag. */
7936 		if ((tp->snd_max - tp->snd_una) == 0)
7937 			rack->r_ctl.rc_hpts_flags &= ~PACE_PKT_OUTPUT;
7938 		rack_log_to_cancel(rack, hpts_removed, line, us_cts, &tv, flags_on_entry);
7939 	}
7940 	if (rack->r_ctl.rc_hpts_flags & PACE_TMR_MASK) {
7941 		rack->rc_tmr_stopped = rack->r_ctl.rc_hpts_flags & PACE_TMR_MASK;
7942 		if (tcp_in_hpts(rack->rc_tp) &&
7943 		    ((rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT) == 0)) {
7944 			/*
7945 			 * Canceling timer's when we have no output being
7946 			 * paced. We also must remove ourselves from the
7947 			 * hpts.
7948 			 */
7949 			tcp_hpts_remove(rack->rc_tp);
7950 			hpts_removed = 1;
7951 		}
7952 		rack->r_ctl.rc_hpts_flags &= ~(PACE_TMR_MASK);
7953 	}
7954 	if (hpts_removed == 0)
7955 		rack_log_to_cancel(rack, hpts_removed, line, us_cts, &tv, flags_on_entry);
7956 }
7957 
7958 static int
7959 rack_stopall(struct tcpcb *tp)
7960 {
7961 	struct tcp_rack *rack;
7962 
7963 	rack = (struct tcp_rack *)tp->t_fb_ptr;
7964 	rack->t_timers_stopped = 1;
7965 
7966 	tcp_hpts_remove(tp);
7967 
7968 	return (0);
7969 }
7970 
7971 static void
7972 rack_stop_all_timers(struct tcpcb *tp, struct tcp_rack *rack)
7973 {
7974 	/*
7975 	 * Assure no timers are running.
7976 	 */
7977 	if (tcp_timer_active(tp, TT_PERSIST)) {
7978 		/* We enter in persists, set the flag appropriately */
7979 		rack->rc_in_persist = 1;
7980 	}
7981 	if (tcp_in_hpts(rack->rc_tp)) {
7982 		tcp_hpts_remove(rack->rc_tp);
7983 	}
7984 }
7985 
7986 static void
7987 rack_update_rsm(struct tcpcb *tp, struct tcp_rack *rack,
7988     struct rack_sendmap *rsm, uint64_t ts, uint32_t add_flag, int segsiz)
7989 {
7990 	int32_t idx;
7991 
7992 	rsm->r_rtr_cnt++;
7993 	if (rsm->r_rtr_cnt > RACK_NUM_OF_RETRANS) {
7994 		rsm->r_rtr_cnt = RACK_NUM_OF_RETRANS;
7995 		rsm->r_flags |= RACK_OVERMAX;
7996 	}
7997 	rsm->r_act_rxt_cnt++;
7998 	/* Peg the count/index */
7999 	rack_log_retran_reason(rack, rsm, __LINE__, 0, 2);
8000 	rsm->r_dupack = 0;
8001 	if ((rsm->r_rtr_cnt > 1) && ((rsm->r_flags & RACK_TLP) == 0)) {
8002 		rack->r_ctl.rc_holes_rxt += (rsm->r_end - rsm->r_start);
8003 		rsm->r_rtr_bytes += (rsm->r_end - rsm->r_start);
8004 	}
8005 	if (rsm->r_flags & RACK_WAS_LOST) {
8006 		/*
8007 		 * We retransmitted it putting it back in flight
8008 		 * remove the lost desgination and reduce the
8009 		 * bytes considered lost.
8010 		 */
8011 		rack_mark_nolonger_lost(rack, rsm);
8012 	}
8013 	idx = rsm->r_rtr_cnt - 1;
8014 	rsm->r_tim_lastsent[idx] = ts;
8015 	/*
8016 	 * Here we don't add in the len of send, since its already
8017 	 * in snduna <->snd_max.
8018 	 */
8019 	rsm->r_fas = ctf_flight_size(rack->rc_tp,
8020 				     rack->r_ctl.rc_sacked);
8021 	if (rsm->r_flags & RACK_ACKED) {
8022 		/* Problably MTU discovery messing with us */
8023 		rsm->r_flags &= ~RACK_ACKED;
8024 		rack->r_ctl.rc_sacked -= (rsm->r_end - rsm->r_start);
8025 	}
8026 	if (rsm->r_in_tmap) {
8027 		TAILQ_REMOVE(&rack->r_ctl.rc_tmap, rsm, r_tnext);
8028 		rsm->r_in_tmap = 0;
8029 	}
8030 	/* Lets make sure it really is in or not the GP window */
8031 	rack_mark_in_gp_win(tp, rsm);
8032 	TAILQ_INSERT_TAIL(&rack->r_ctl.rc_tmap, rsm, r_tnext);
8033 	rsm->r_in_tmap = 1;
8034 	rsm->r_bas = (uint8_t)(((rsm->r_end - rsm->r_start) + segsiz - 1) / segsiz);
8035 	/* Take off the must retransmit flag, if its on */
8036 	if (rsm->r_flags & RACK_MUST_RXT) {
8037 		if (rack->r_must_retran)
8038 			rack->r_ctl.rc_out_at_rto -= (rsm->r_end - rsm->r_start);
8039 		if (SEQ_GEQ(rsm->r_end, rack->r_ctl.rc_snd_max_at_rto)) {
8040 			/*
8041 			 * We have retransmitted all we need. Clear
8042 			 * any must retransmit flags.
8043 			 */
8044 			rack->r_must_retran = 0;
8045 			rack->r_ctl.rc_out_at_rto = 0;
8046 		}
8047 		rsm->r_flags &= ~RACK_MUST_RXT;
8048 	}
8049 	/* Remove any collapsed flag */
8050 	rsm->r_flags &= ~RACK_RWND_COLLAPSED;
8051 	if (rsm->r_flags & RACK_SACK_PASSED) {
8052 		/* We have retransmitted due to the SACK pass */
8053 		rsm->r_flags &= ~RACK_SACK_PASSED;
8054 		rsm->r_flags |= RACK_WAS_SACKPASS;
8055 		rack->r_ctl.recovery_rxt_cnt += (rsm->r_end - rsm->r_start);
8056 	}
8057 }
8058 
8059 static uint32_t
8060 rack_update_entry(struct tcpcb *tp, struct tcp_rack *rack,
8061     struct rack_sendmap *rsm, uint64_t ts, int32_t *lenp, uint32_t add_flag, int segsiz)
8062 {
8063 	/*
8064 	 * We (re-)transmitted starting at rsm->r_start for some length
8065 	 * (possibly less than r_end.
8066 	 */
8067 	struct rack_sendmap *nrsm;
8068 	int insret __diagused;
8069 	uint32_t c_end;
8070 	int32_t len;
8071 
8072 	len = *lenp;
8073 	c_end = rsm->r_start + len;
8074 	if (SEQ_GEQ(c_end, rsm->r_end)) {
8075 		/*
8076 		 * We retransmitted the whole piece or more than the whole
8077 		 * slopping into the next rsm.
8078 		 */
8079 		rack_update_rsm(tp, rack, rsm, ts, add_flag, segsiz);
8080 		if (c_end == rsm->r_end) {
8081 			*lenp = 0;
8082 			return (0);
8083 		} else {
8084 			int32_t act_len;
8085 
8086 			/* Hangs over the end return whats left */
8087 			act_len = rsm->r_end - rsm->r_start;
8088 			*lenp = (len - act_len);
8089 			return (rsm->r_end);
8090 		}
8091 		/* We don't get out of this block. */
8092 	}
8093 	/*
8094 	 * Here we retransmitted less than the whole thing which means we
8095 	 * have to split this into what was transmitted and what was not.
8096 	 */
8097 	nrsm = rack_alloc_full_limit(rack);
8098 	if (nrsm == NULL) {
8099 		/*
8100 		 * We can't get memory, so lets not proceed.
8101 		 */
8102 		*lenp = 0;
8103 		return (0);
8104 	}
8105 	/*
8106 	 * So here we are going to take the original rsm and make it what we
8107 	 * retransmitted. nrsm will be the tail portion we did not
8108 	 * retransmit. For example say the chunk was 1, 11 (10 bytes). And
8109 	 * we retransmitted 5 bytes i.e. 1, 5. The original piece shrinks to
8110 	 * 1, 6 and the new piece will be 6, 11.
8111 	 */
8112 	rack_clone_rsm(rack, nrsm, rsm, c_end);
8113 	nrsm->r_dupack = 0;
8114 	rack_log_retran_reason(rack, nrsm, __LINE__, 0, 2);
8115 #ifndef INVARIANTS
8116 	(void)tqhash_insert(rack->r_ctl.tqh, nrsm);
8117 #else
8118 	if ((insret = tqhash_insert(rack->r_ctl.tqh, nrsm)) != 0) {
8119 		panic("Insert in tailq_hash of %p fails ret:%d rack:%p rsm:%p",
8120 		      nrsm, insret, rack, rsm);
8121 	}
8122 #endif
8123 	if (rsm->r_in_tmap) {
8124 		TAILQ_INSERT_AFTER(&rack->r_ctl.rc_tmap, rsm, nrsm, r_tnext);
8125 		nrsm->r_in_tmap = 1;
8126 	}
8127 	rsm->r_flags &= (~RACK_HAS_FIN);
8128 	rack_update_rsm(tp, rack, rsm, ts, add_flag, segsiz);
8129 	/* Log a split of rsm into rsm and nrsm */
8130 	rack_log_map_chg(tp, rack, NULL, rsm, nrsm, MAP_SPLIT, 0, __LINE__);
8131 	*lenp = 0;
8132 	return (0);
8133 }
8134 
8135 static void
8136 rack_log_output(struct tcpcb *tp, struct tcpopt *to, int32_t len,
8137 		uint32_t seq_out, uint16_t th_flags, int32_t err, uint64_t cts,
8138 		struct rack_sendmap *hintrsm, uint32_t add_flag, struct mbuf *s_mb,
8139 		uint32_t s_moff, int hw_tls, int segsiz)
8140 {
8141 	struct tcp_rack *rack;
8142 	struct rack_sendmap *rsm, *nrsm;
8143 	int insret __diagused;
8144 
8145 	register uint32_t snd_max, snd_una;
8146 
8147 	/*
8148 	 * Add to the RACK log of packets in flight or retransmitted. If
8149 	 * there is a TS option we will use the TS echoed, if not we will
8150 	 * grab a TS.
8151 	 *
8152 	 * Retransmissions will increment the count and move the ts to its
8153 	 * proper place. Note that if options do not include TS's then we
8154 	 * won't be able to effectively use the ACK for an RTT on a retran.
8155 	 *
8156 	 * Notes about r_start and r_end. Lets consider a send starting at
8157 	 * sequence 1 for 10 bytes. In such an example the r_start would be
8158 	 * 1 (starting sequence) but the r_end would be r_start+len i.e. 11.
8159 	 * This means that r_end is actually the first sequence for the next
8160 	 * slot (11).
8161 	 *
8162 	 */
8163 	/*
8164 	 * If err is set what do we do XXXrrs? should we not add the thing?
8165 	 * -- i.e. return if err != 0 or should we pretend we sent it? --
8166 	 * i.e. proceed with add ** do this for now.
8167 	 */
8168 	INP_WLOCK_ASSERT(tptoinpcb(tp));
8169 	if (err)
8170 		/*
8171 		 * We don't log errors -- we could but snd_max does not
8172 		 * advance in this case either.
8173 		 */
8174 		return;
8175 
8176 	if (th_flags & TH_RST) {
8177 		/*
8178 		 * We don't log resets and we return immediately from
8179 		 * sending
8180 		 */
8181 		return;
8182 	}
8183 	rack = (struct tcp_rack *)tp->t_fb_ptr;
8184 	snd_una = tp->snd_una;
8185 	snd_max = tp->snd_max;
8186 	if (th_flags & (TH_SYN | TH_FIN)) {
8187 		/*
8188 		 * The call to rack_log_output is made before bumping
8189 		 * snd_max. This means we can record one extra byte on a SYN
8190 		 * or FIN if seq_out is adding more on and a FIN is present
8191 		 * (and we are not resending).
8192 		 */
8193 		if ((th_flags & TH_SYN) && (seq_out == tp->iss))
8194 			len++;
8195 		if (th_flags & TH_FIN)
8196 			len++;
8197 	}
8198 	if (SEQ_LEQ((seq_out + len), snd_una)) {
8199 		/* Are sending an old segment to induce an ack (keep-alive)? */
8200 		return;
8201 	}
8202 	if (SEQ_LT(seq_out, snd_una)) {
8203 		/* huh? should we panic? */
8204 		uint32_t end;
8205 
8206 		end = seq_out + len;
8207 		seq_out = snd_una;
8208 		if (SEQ_GEQ(end, seq_out))
8209 			len = end - seq_out;
8210 		else
8211 			len = 0;
8212 	}
8213 	if (len == 0) {
8214 		/* We don't log zero window probes */
8215 		return;
8216 	}
8217 	if (IN_FASTRECOVERY(tp->t_flags)) {
8218 		rack->r_ctl.rc_prr_out += len;
8219 	}
8220 	/* First question is it a retransmission or new? */
8221 	if (seq_out == snd_max) {
8222 		/* Its new */
8223 		rack_chk_req_and_hybrid_on_out(rack, seq_out, len, cts);
8224 again:
8225 		rsm = rack_alloc(rack);
8226 		if (rsm == NULL) {
8227 			/*
8228 			 * Hmm out of memory and the tcb got destroyed while
8229 			 * we tried to wait.
8230 			 */
8231 			return;
8232 		}
8233 		if (th_flags & TH_FIN) {
8234 			rsm->r_flags = RACK_HAS_FIN|add_flag;
8235 		} else {
8236 			rsm->r_flags = add_flag;
8237 		}
8238 		if (hw_tls)
8239 			rsm->r_hw_tls = 1;
8240 		rsm->r_tim_lastsent[0] = cts;
8241 		rsm->r_rtr_cnt = 1;
8242  		rsm->r_act_rxt_cnt = 0;
8243 		rsm->r_rtr_bytes = 0;
8244 		if (th_flags & TH_SYN) {
8245 			/* The data space is one beyond snd_una */
8246 			rsm->r_flags |= RACK_HAS_SYN;
8247 		}
8248 		rsm->r_start = seq_out;
8249 		rsm->r_end = rsm->r_start + len;
8250 		rack_mark_in_gp_win(tp, rsm);
8251 		rsm->r_dupack = 0;
8252 		/*
8253 		 * save off the mbuf location that
8254 		 * sndmbuf_noadv returned (which is
8255 		 * where we started copying from)..
8256 		 */
8257 		rsm->m = s_mb;
8258 		rsm->soff = s_moff;
8259 		/*
8260 		 * Here we do add in the len of send, since its not yet
8261 		 * reflected in in snduna <->snd_max
8262 		 */
8263 		rsm->r_fas = (ctf_flight_size(rack->rc_tp,
8264 					      rack->r_ctl.rc_sacked) +
8265 			      (rsm->r_end - rsm->r_start));
8266 		if ((rack->rc_initial_ss_comp == 0) &&
8267 		    (rack->r_ctl.ss_hi_fs < rsm->r_fas)) {
8268 			   rack->r_ctl.ss_hi_fs = rsm->r_fas;
8269 		}
8270 		/* rsm->m will be NULL if RACK_HAS_SYN or RACK_HAS_FIN is set */
8271 		if (rsm->m) {
8272 			if (rsm->m->m_len <= rsm->soff) {
8273 				/*
8274 				 * XXXrrs Question, will this happen?
8275 				 *
8276 				 * If sbsndptr is set at the correct place
8277 				 * then s_moff should always be somewhere
8278 				 * within rsm->m. But if the sbsndptr was
8279 				 * off then that won't be true. If it occurs
8280 				 * we need to walkout to the correct location.
8281 				 */
8282 				struct mbuf *lm;
8283 
8284 				lm = rsm->m;
8285 				while (lm->m_len <= rsm->soff) {
8286 					rsm->soff -= lm->m_len;
8287 					lm = lm->m_next;
8288 					KASSERT(lm != NULL, ("%s rack:%p lm goes null orig_off:%u origmb:%p rsm->soff:%u",
8289 							     __func__, rack, s_moff, s_mb, rsm->soff));
8290 				}
8291 				rsm->m = lm;
8292 			}
8293 			rsm->orig_m_len = rsm->m->m_len;
8294 			rsm->orig_t_space = M_TRAILINGROOM(rsm->m);
8295 		} else {
8296 			rsm->orig_m_len = 0;
8297 			rsm->orig_t_space = 0;
8298 		}
8299 		rsm->r_bas = (uint8_t)((len + segsiz - 1) / segsiz);
8300 		rack_log_retran_reason(rack, rsm, __LINE__, 0, 2);
8301 		/* Log a new rsm */
8302 		rack_log_map_chg(tp, rack, NULL, rsm, NULL, MAP_NEW, 0, __LINE__);
8303 #ifndef INVARIANTS
8304 		(void)tqhash_insert(rack->r_ctl.tqh, rsm);
8305 #else
8306 		if ((insret = tqhash_insert(rack->r_ctl.tqh, rsm)) != 0) {
8307 			panic("Insert in tailq_hash of %p fails ret:%d rack:%p rsm:%p",
8308 			      nrsm, insret, rack, rsm);
8309 		}
8310 #endif
8311 		TAILQ_INSERT_TAIL(&rack->r_ctl.rc_tmap, rsm, r_tnext);
8312 		rsm->r_in_tmap = 1;
8313 		if (rsm->r_flags & RACK_IS_PCM) {
8314 			rack->r_ctl.pcm_i.send_time = cts;
8315 			rack->r_ctl.pcm_i.eseq = rsm->r_end;
8316 			/* First time through we set the start too */
8317 			if (rack->pcm_in_progress == 0)
8318 				rack->r_ctl.pcm_i.sseq = rsm->r_start;
8319 		}
8320 		/*
8321 		 * Special case detection, is there just a single
8322 		 * packet outstanding when we are not in recovery?
8323 		 *
8324 		 * If this is true mark it so.
8325 		 */
8326 		if ((IN_FASTRECOVERY(tp->t_flags) == 0) &&
8327 		    (ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked) == ctf_fixed_maxseg(tp))) {
8328 			struct rack_sendmap *prsm;
8329 
8330 			prsm = tqhash_prev(rack->r_ctl.tqh, rsm);
8331 			if (prsm)
8332 				prsm->r_one_out_nr = 1;
8333 		}
8334 		return;
8335 	}
8336 	/*
8337 	 * If we reach here its a retransmission and we need to find it.
8338 	 */
8339 more:
8340 	if (hintrsm && (hintrsm->r_start == seq_out)) {
8341 		rsm = hintrsm;
8342 		hintrsm = NULL;
8343 	} else {
8344 		/* No hints sorry */
8345 		rsm = NULL;
8346 	}
8347 	if ((rsm) && (rsm->r_start == seq_out)) {
8348 		seq_out = rack_update_entry(tp, rack, rsm, cts, &len, add_flag, segsiz);
8349 		if (len == 0) {
8350 			return;
8351 		} else {
8352 			goto more;
8353 		}
8354 	}
8355 	/* Ok it was not the last pointer go through it the hard way. */
8356 refind:
8357 	rsm = tqhash_find(rack->r_ctl.tqh, seq_out);
8358 	if (rsm) {
8359 		if (rsm->r_start == seq_out) {
8360 			seq_out = rack_update_entry(tp, rack, rsm, cts, &len, add_flag, segsiz);
8361 			if (len == 0) {
8362 				return;
8363 			} else {
8364 				goto refind;
8365 			}
8366 		}
8367 		if (SEQ_GEQ(seq_out, rsm->r_start) && SEQ_LT(seq_out, rsm->r_end)) {
8368 			/* Transmitted within this piece */
8369 			/*
8370 			 * Ok we must split off the front and then let the
8371 			 * update do the rest
8372 			 */
8373 			nrsm = rack_alloc_full_limit(rack);
8374 			if (nrsm == NULL) {
8375 				rack_update_rsm(tp, rack, rsm, cts, add_flag, segsiz);
8376 				return;
8377 			}
8378 			/*
8379 			 * copy rsm to nrsm and then trim the front of rsm
8380 			 * to not include this part.
8381 			 */
8382 			rack_clone_rsm(rack, nrsm, rsm, seq_out);
8383 			rack_log_map_chg(tp, rack, NULL, rsm, nrsm, MAP_SPLIT, 0, __LINE__);
8384 #ifndef INVARIANTS
8385 			(void)tqhash_insert(rack->r_ctl.tqh, nrsm);
8386 #else
8387 			if ((insret = tqhash_insert(rack->r_ctl.tqh, nrsm)) != 0) {
8388 				panic("Insert in tailq_hash of %p fails ret:%d rack:%p rsm:%p",
8389 				      nrsm, insret, rack, rsm);
8390 			}
8391 #endif
8392 			if (rsm->r_in_tmap) {
8393 				TAILQ_INSERT_AFTER(&rack->r_ctl.rc_tmap, rsm, nrsm, r_tnext);
8394 				nrsm->r_in_tmap = 1;
8395 			}
8396 			rsm->r_flags &= (~RACK_HAS_FIN);
8397 			seq_out = rack_update_entry(tp, rack, nrsm, cts, &len, add_flag, segsiz);
8398 			if (len == 0) {
8399 				return;
8400 			} else if (len > 0)
8401 				goto refind;
8402 		}
8403 	}
8404 	/*
8405 	 * Hmm not found in map did they retransmit both old and on into the
8406 	 * new?
8407 	 */
8408 	if (seq_out == tp->snd_max) {
8409 		goto again;
8410 	} else if (SEQ_LT(seq_out, tp->snd_max)) {
8411 #ifdef INVARIANTS
8412 		printf("seq_out:%u len:%d snd_una:%u snd_max:%u -- but rsm not found?\n",
8413 		       seq_out, len, tp->snd_una, tp->snd_max);
8414 		printf("Starting Dump of all rack entries\n");
8415 		TQHASH_FOREACH(rsm, rack->r_ctl.tqh)  {
8416 			printf("rsm:%p start:%u end:%u\n",
8417 			       rsm, rsm->r_start, rsm->r_end);
8418 		}
8419 		printf("Dump complete\n");
8420 		panic("seq_out not found rack:%p tp:%p",
8421 		      rack, tp);
8422 #endif
8423 	} else {
8424 #ifdef INVARIANTS
8425 		/*
8426 		 * Hmm beyond sndmax? (only if we are using the new rtt-pack
8427 		 * flag)
8428 		 */
8429 		panic("seq_out:%u(%d) is beyond snd_max:%u tp:%p",
8430 		      seq_out, len, tp->snd_max, tp);
8431 #endif
8432 	}
8433 }
8434 
8435 /*
8436  * Record one of the RTT updates from an ack into
8437  * our sample structure.
8438  */
8439 
8440 static void
8441 tcp_rack_xmit_timer(struct tcp_rack *rack, int32_t rtt, uint32_t len, uint32_t us_rtt,
8442 		    int confidence, struct rack_sendmap *rsm, uint16_t rtrcnt)
8443 {
8444 	if ((rack->r_ctl.rack_rs.rs_flags & RACK_RTT_EMPTY) ||
8445 	    (rack->r_ctl.rack_rs.rs_rtt_lowest > rtt)) {
8446 		rack->r_ctl.rack_rs.rs_rtt_lowest = rtt;
8447 	}
8448 	if ((rack->r_ctl.rack_rs.rs_flags & RACK_RTT_EMPTY) ||
8449 	    (rack->r_ctl.rack_rs.rs_rtt_highest < rtt)) {
8450 		rack->r_ctl.rack_rs.rs_rtt_highest = rtt;
8451 	}
8452 	if (rack->rc_tp->t_flags & TF_GPUTINPROG) {
8453 	    if (us_rtt < rack->r_ctl.rc_gp_lowrtt)
8454 		rack->r_ctl.rc_gp_lowrtt = us_rtt;
8455 	    if (rack->rc_tp->snd_wnd > rack->r_ctl.rc_gp_high_rwnd)
8456 		    rack->r_ctl.rc_gp_high_rwnd = rack->rc_tp->snd_wnd;
8457 	}
8458 	if ((confidence == 1) &&
8459 	    ((rsm == NULL) ||
8460 	     (rsm->r_just_ret) ||
8461 	     (rsm->r_one_out_nr &&
8462 	      len < (ctf_fixed_maxseg(rack->rc_tp) * 2)))) {
8463 		/*
8464 		 * If the rsm had a just return
8465 		 * hit it then we can't trust the
8466 		 * rtt measurement for buffer deterimination
8467 		 * Note that a confidence of 2, indicates
8468 		 * SACK'd which overrides the r_just_ret or
8469 		 * the r_one_out_nr. If it was a CUM-ACK and
8470 		 * we had only two outstanding, but get an
8471 		 * ack for only 1. Then that also lowers our
8472 		 * confidence.
8473 		 */
8474 		confidence = 0;
8475 	}
8476 	if ((rack->r_ctl.rack_rs.rs_flags & RACK_RTT_EMPTY) ||
8477 	    (rack->r_ctl.rack_rs.rs_us_rtt > us_rtt)) {
8478 		if (rack->r_ctl.rack_rs.confidence == 0) {
8479 			/*
8480 			 * We take anything with no current confidence
8481 			 * saved.
8482 			 */
8483 			rack->r_ctl.rack_rs.rs_us_rtt = us_rtt;
8484 			rack->r_ctl.rack_rs.confidence = confidence;
8485 			rack->r_ctl.rack_rs.rs_us_rtrcnt = rtrcnt;
8486 		} else if (confidence != 0) {
8487 			/*
8488 			 * Once we have a confident number,
8489 			 * we can update it with a smaller
8490 			 * value since this confident number
8491 			 * may include the DSACK time until
8492 			 * the next segment (the second one) arrived.
8493 			 */
8494 			rack->r_ctl.rack_rs.rs_us_rtt = us_rtt;
8495 			rack->r_ctl.rack_rs.confidence = confidence;
8496 			rack->r_ctl.rack_rs.rs_us_rtrcnt = rtrcnt;
8497 		}
8498 	}
8499 	rack_log_rtt_upd(rack->rc_tp, rack, us_rtt, len, rsm, confidence);
8500 	rack->r_ctl.rack_rs.rs_flags = RACK_RTT_VALID;
8501 	rack->r_ctl.rack_rs.rs_rtt_tot += rtt;
8502 	rack->r_ctl.rack_rs.rs_rtt_cnt++;
8503 }
8504 
8505 /*
8506  * Collect new round-trip time estimate
8507  * and update averages and current timeout.
8508  */
8509 static void
8510 tcp_rack_xmit_timer_commit(struct tcp_rack *rack, struct tcpcb *tp)
8511 {
8512 	int32_t delta;
8513 	int32_t rtt;
8514 
8515 	if (rack->r_ctl.rack_rs.rs_flags & RACK_RTT_EMPTY)
8516 		/* No valid sample */
8517 		return;
8518 	if (rack->r_ctl.rc_rate_sample_method == USE_RTT_LOW) {
8519 		/* We are to use the lowest RTT seen in a single ack */
8520 		rtt = rack->r_ctl.rack_rs.rs_rtt_lowest;
8521 	} else if (rack->r_ctl.rc_rate_sample_method == USE_RTT_HIGH) {
8522 		/* We are to use the highest RTT seen in a single ack */
8523 		rtt = rack->r_ctl.rack_rs.rs_rtt_highest;
8524 	} else if (rack->r_ctl.rc_rate_sample_method == USE_RTT_AVG) {
8525 		/* We are to use the average RTT seen in a single ack */
8526 		rtt = (int32_t)(rack->r_ctl.rack_rs.rs_rtt_tot /
8527 				(uint64_t)rack->r_ctl.rack_rs.rs_rtt_cnt);
8528 	} else {
8529 #ifdef INVARIANTS
8530 		panic("Unknown rtt variant %d", rack->r_ctl.rc_rate_sample_method);
8531 #endif
8532 		return;
8533 	}
8534 	if (rtt == 0)
8535 		rtt = 1;
8536 	if (rack->rc_gp_rtt_set == 0) {
8537 		/*
8538 		 * With no RTT we have to accept
8539 		 * even one we are not confident of.
8540 		 */
8541 		rack->r_ctl.rc_gp_srtt = rack->r_ctl.rack_rs.rs_us_rtt;
8542 		rack->rc_gp_rtt_set = 1;
8543 	} else if (rack->r_ctl.rack_rs.confidence) {
8544 		/* update the running gp srtt */
8545 		rack->r_ctl.rc_gp_srtt -= (rack->r_ctl.rc_gp_srtt/8);
8546 		rack->r_ctl.rc_gp_srtt += rack->r_ctl.rack_rs.rs_us_rtt / 8;
8547 	}
8548 	if (rack->r_ctl.rack_rs.confidence) {
8549 		/*
8550 		 * record the low and high for highly buffered path computation,
8551 		 * we only do this if we are confident (not a retransmission).
8552 		 */
8553 		if (rack->r_ctl.rc_highest_us_rtt < rack->r_ctl.rack_rs.rs_us_rtt) {
8554 			rack->r_ctl.rc_highest_us_rtt = rack->r_ctl.rack_rs.rs_us_rtt;
8555 		}
8556 		if (rack->rc_highly_buffered == 0) {
8557 			/*
8558 			 * Currently once we declare a path has
8559 			 * highly buffered there is no going
8560 			 * back, which may be a problem...
8561 			 */
8562 			if ((rack->r_ctl.rc_highest_us_rtt / rack->r_ctl.rc_lowest_us_rtt) > rack_hbp_thresh) {
8563 				rack_log_rtt_shrinks(rack, rack->r_ctl.rack_rs.rs_us_rtt,
8564 						     rack->r_ctl.rc_highest_us_rtt,
8565 						     rack->r_ctl.rc_lowest_us_rtt,
8566 						     RACK_RTTS_SEEHBP);
8567 				rack->rc_highly_buffered = 1;
8568 			}
8569 		}
8570 	}
8571 	if ((rack->r_ctl.rack_rs.confidence) ||
8572 	    (rack->r_ctl.rack_rs.rs_us_rtrcnt == 1)) {
8573 		/*
8574 		 * If we are highly confident of it <or> it was
8575 		 * never retransmitted we accept it as the last us_rtt.
8576 		 */
8577 		rack->r_ctl.rc_last_us_rtt = rack->r_ctl.rack_rs.rs_us_rtt;
8578 		/* The lowest rtt can be set if its was not retransmited */
8579 		if (rack->r_ctl.rc_lowest_us_rtt > rack->r_ctl.rack_rs.rs_us_rtt) {
8580 			rack->r_ctl.rc_lowest_us_rtt = rack->r_ctl.rack_rs.rs_us_rtt;
8581 			if (rack->r_ctl.rc_lowest_us_rtt == 0)
8582 				rack->r_ctl.rc_lowest_us_rtt = 1;
8583 		}
8584 	}
8585 	rack = (struct tcp_rack *)tp->t_fb_ptr;
8586 	if (tp->t_srtt != 0) {
8587 		/*
8588 		 * We keep a simple srtt in microseconds, like our rtt
8589 		 * measurement. We don't need to do any tricks with shifting
8590 		 * etc. Instead we just add in 1/8th of the new measurement
8591 		 * and subtract out 1/8 of the old srtt. We do the same with
8592 		 * the variance after finding the absolute value of the
8593 		 * difference between this sample and the current srtt.
8594 		 */
8595 		delta = tp->t_srtt - rtt;
8596 		/* Take off 1/8th of the current sRTT */
8597 		tp->t_srtt -= (tp->t_srtt >> 3);
8598 		/* Add in 1/8th of the new RTT just measured */
8599 		tp->t_srtt += (rtt >> 3);
8600 		if (tp->t_srtt <= 0)
8601 			tp->t_srtt = 1;
8602 		/* Now lets make the absolute value of the variance */
8603 		if (delta < 0)
8604 			delta = -delta;
8605 		/* Subtract out 1/8th */
8606 		tp->t_rttvar -= (tp->t_rttvar >> 3);
8607 		/* Add in 1/8th of the new variance we just saw */
8608 		tp->t_rttvar += (delta >> 3);
8609 		if (tp->t_rttvar <= 0)
8610 			tp->t_rttvar = 1;
8611 	} else {
8612 		/*
8613 		 * No rtt measurement yet - use the unsmoothed rtt. Set the
8614 		 * variance to half the rtt (so our first retransmit happens
8615 		 * at 3*rtt).
8616 		 */
8617 		tp->t_srtt = rtt;
8618 		tp->t_rttvar = rtt >> 1;
8619 	}
8620 	rack->rc_srtt_measure_made = 1;
8621 	KMOD_TCPSTAT_INC(tcps_rttupdated);
8622 	if (tp->t_rttupdated < UCHAR_MAX)
8623 		tp->t_rttupdated++;
8624 #ifdef STATS
8625 	if (rack_stats_gets_ms_rtt == 0) {
8626 		/* Send in the microsecond rtt used for rxt timeout purposes */
8627 		stats_voi_update_abs_u32(tp->t_stats, VOI_TCP_RTT, imax(0, rtt));
8628 	} else if (rack_stats_gets_ms_rtt == 1) {
8629 		/* Send in the millisecond rtt used for rxt timeout purposes */
8630 		int32_t ms_rtt;
8631 
8632 		/* Round up */
8633 		ms_rtt = (rtt + HPTS_USEC_IN_MSEC - 1) / HPTS_USEC_IN_MSEC;
8634 		stats_voi_update_abs_u32(tp->t_stats, VOI_TCP_RTT, imax(0, ms_rtt));
8635 	} else if (rack_stats_gets_ms_rtt == 2) {
8636 		/* Send in the millisecond rtt has close to the path RTT as we can get  */
8637 		int32_t ms_rtt;
8638 
8639 		/* Round up */
8640 		ms_rtt = (rack->r_ctl.rack_rs.rs_us_rtt + HPTS_USEC_IN_MSEC - 1) / HPTS_USEC_IN_MSEC;
8641 		stats_voi_update_abs_u32(tp->t_stats, VOI_TCP_RTT, imax(0, ms_rtt));
8642 	}  else {
8643 		/* Send in the microsecond rtt has close to the path RTT as we can get  */
8644 		stats_voi_update_abs_u32(tp->t_stats, VOI_TCP_RTT, imax(0, rack->r_ctl.rack_rs.rs_us_rtt));
8645 	}
8646 	stats_voi_update_abs_u32(tp->t_stats, VOI_TCP_PATHRTT, imax(0, rack->r_ctl.rack_rs.rs_us_rtt));
8647 #endif
8648 	rack->r_ctl.last_rcv_tstmp_for_rtt = tcp_tv_to_msec(&rack->r_ctl.act_rcv_time);
8649 	/*
8650 	 * the retransmit should happen at rtt + 4 * rttvar. Because of the
8651 	 * way we do the smoothing, srtt and rttvar will each average +1/2
8652 	 * tick of bias.  When we compute the retransmit timer, we want 1/2
8653 	 * tick of rounding and 1 extra tick because of +-1/2 tick
8654 	 * uncertainty in the firing of the timer.  The bias will give us
8655 	 * exactly the 1.5 tick we need.  But, because the bias is
8656 	 * statistical, we have to test that we don't drop below the minimum
8657 	 * feasible timer (which is 2 ticks).
8658 	 */
8659 	tp->t_rxtshift = 0;
8660 	RACK_TCPT_RANGESET(tp->t_rxtcur, RACK_REXMTVAL(tp),
8661 		      max(rack_rto_min, rtt + 2), rack_rto_max, rack->r_ctl.timer_slop);
8662 	rack_log_rtt_sample(rack, rtt);
8663 	tp->t_softerror = 0;
8664 }
8665 
8666 
8667 static void
8668 rack_apply_updated_usrtt(struct tcp_rack *rack, uint32_t us_rtt, uint32_t us_cts)
8669 {
8670 	/*
8671 	 * Apply to filter the inbound us-rtt at us_cts.
8672 	 */
8673 	uint32_t old_rtt;
8674 
8675 	old_rtt = get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt);
8676 	apply_filter_min_small(&rack->r_ctl.rc_gp_min_rtt,
8677 			       us_rtt, us_cts);
8678 	if (old_rtt > us_rtt) {
8679 		/* We just hit a new lower rtt time */
8680 		rack_log_rtt_shrinks(rack,  us_cts,  old_rtt,
8681 				     __LINE__, RACK_RTTS_NEWRTT);
8682 		/*
8683 		 * Only count it if its lower than what we saw within our
8684 		 * calculated range.
8685 		 */
8686 		if ((old_rtt - us_rtt) > rack_min_rtt_movement) {
8687 			if (rack_probertt_lower_within &&
8688 			    rack->rc_gp_dyn_mul &&
8689 			    (rack->use_fixed_rate == 0) &&
8690 			    (rack->rc_always_pace)) {
8691 				/*
8692 				 * We are seeing a new lower rtt very close
8693 				 * to the time that we would have entered probe-rtt.
8694 				 * This is probably due to the fact that a peer flow
8695 				 * has entered probe-rtt. Lets go in now too.
8696 				 */
8697 				uint32_t val;
8698 
8699 				val = rack_probertt_lower_within * rack_time_between_probertt;
8700 				val /= 100;
8701 				if ((rack->in_probe_rtt == 0) &&
8702 				    (rack->rc_skip_timely == 0) &&
8703 				    ((us_cts - rack->r_ctl.rc_lower_rtt_us_cts) >= (rack_time_between_probertt - val)))	{
8704 					rack_enter_probertt(rack, us_cts);
8705 				}
8706 			}
8707 			rack->r_ctl.rc_lower_rtt_us_cts = us_cts;
8708 		}
8709 	}
8710 }
8711 
8712 static int
8713 rack_update_rtt(struct tcpcb *tp, struct tcp_rack *rack,
8714     struct rack_sendmap *rsm, struct tcpopt *to, uint32_t cts, int32_t ack_type, tcp_seq th_ack)
8715 {
8716 	uint32_t us_rtt;
8717 	int32_t i, all;
8718 	uint32_t t, len_acked;
8719 
8720 	if ((rsm->r_flags & RACK_ACKED) ||
8721 	    (rsm->r_flags & RACK_WAS_ACKED))
8722 		/* Already done */
8723 		return (0);
8724 	if (rsm->r_no_rtt_allowed) {
8725 		/* Not allowed */
8726 		return (0);
8727 	}
8728 	if (ack_type == CUM_ACKED) {
8729 		if (SEQ_GT(th_ack, rsm->r_end)) {
8730 			len_acked = rsm->r_end - rsm->r_start;
8731 			all = 1;
8732 		} else {
8733 			len_acked = th_ack - rsm->r_start;
8734 			all = 0;
8735 		}
8736 	} else {
8737 		len_acked = rsm->r_end - rsm->r_start;
8738 		all = 0;
8739 	}
8740 	if (rsm->r_rtr_cnt == 1) {
8741 
8742 		t = cts - (uint32_t)rsm->r_tim_lastsent[(rsm->r_rtr_cnt - 1)];
8743 		if ((int)t <= 0)
8744 			t = 1;
8745 		if (!tp->t_rttlow || tp->t_rttlow > t)
8746 			tp->t_rttlow = t;
8747 		if (!rack->r_ctl.rc_rack_min_rtt ||
8748 		    SEQ_LT(t, rack->r_ctl.rc_rack_min_rtt)) {
8749 			rack->r_ctl.rc_rack_min_rtt = t;
8750 			if (rack->r_ctl.rc_rack_min_rtt == 0) {
8751 				rack->r_ctl.rc_rack_min_rtt = 1;
8752 			}
8753 		}
8754 		if (TSTMP_GT(tcp_tv_to_usec(&rack->r_ctl.act_rcv_time), rsm->r_tim_lastsent[(rsm->r_rtr_cnt-1)]))
8755 			us_rtt = tcp_tv_to_usec(&rack->r_ctl.act_rcv_time) - (uint32_t)rsm->r_tim_lastsent[(rsm->r_rtr_cnt-1)];
8756 		else
8757 			us_rtt = tcp_get_usecs(NULL) - (uint32_t)rsm->r_tim_lastsent[(rsm->r_rtr_cnt-1)];
8758 		if (us_rtt == 0)
8759 			us_rtt = 1;
8760 		if (CC_ALGO(tp)->rttsample != NULL) {
8761 			/* Kick the RTT to the CC */
8762 			CC_ALGO(tp)->rttsample(&tp->t_ccv, us_rtt, 1, rsm->r_fas);
8763 		}
8764 		rack_apply_updated_usrtt(rack, us_rtt, tcp_tv_to_usec(&rack->r_ctl.act_rcv_time));
8765 		if (ack_type == SACKED) {
8766 			rack_log_rtt_sample_calc(rack, t, (uint32_t)rsm->r_tim_lastsent[(rsm->r_rtr_cnt - 1)], cts, 1);
8767 			tcp_rack_xmit_timer(rack, t + 1, len_acked, us_rtt, 2 , rsm, rsm->r_rtr_cnt);
8768 		} else {
8769 			/*
8770 			 * We need to setup what our confidence
8771 			 * is in this ack.
8772 			 *
8773 			 * If the rsm was app limited and it is
8774 			 * less than a mss in length (the end
8775 			 * of the send) then we have a gap. If we
8776 			 * were app limited but say we were sending
8777 			 * multiple MSS's then we are more confident
8778 			 * int it.
8779 			 *
8780 			 * When we are not app-limited then we see if
8781 			 * the rsm is being included in the current
8782 			 * measurement, we tell this by the app_limited_needs_set
8783 			 * flag.
8784 			 *
8785 			 * Note that being cwnd blocked is not applimited
8786 			 * as well as the pacing delay between packets which
8787 			 * are sending only 1 or 2 MSS's also will show up
8788 			 * in the RTT. We probably need to examine this algorithm
8789 			 * a bit more and enhance it to account for the delay
8790 			 * between rsm's. We could do that by saving off the
8791 			 * pacing delay of each rsm (in an rsm) and then
8792 			 * factoring that in somehow though for now I am
8793 			 * not sure how :)
8794 			 */
8795 			int calc_conf = 0;
8796 
8797 			if (rsm->r_flags & RACK_APP_LIMITED) {
8798 				if (all && (len_acked <= ctf_fixed_maxseg(tp)))
8799 					calc_conf = 0;
8800 				else
8801 					calc_conf = 1;
8802 			} else if (rack->app_limited_needs_set == 0) {
8803 				calc_conf = 1;
8804 			} else {
8805 				calc_conf = 0;
8806 			}
8807 			rack_log_rtt_sample_calc(rack, t, (uint32_t)rsm->r_tim_lastsent[(rsm->r_rtr_cnt - 1)], cts, 2);
8808 			tcp_rack_xmit_timer(rack, t + 1, len_acked, us_rtt,
8809 					    calc_conf, rsm, rsm->r_rtr_cnt);
8810 		}
8811 		if ((rsm->r_flags & RACK_TLP) &&
8812 		    (!IN_FASTRECOVERY(tp->t_flags))) {
8813 			/* Segment was a TLP and our retrans matched */
8814 			if (rack->r_ctl.rc_tlp_cwnd_reduce) {
8815 				rack_cong_signal(tp, CC_NDUPACK, th_ack, __LINE__);
8816 			}
8817 		}
8818 		if ((rack->r_ctl.rc_rack_tmit_time == 0) ||
8819 		    (SEQ_LT(rack->r_ctl.rc_rack_tmit_time,
8820 			    (uint32_t)rsm->r_tim_lastsent[(rsm->r_rtr_cnt - 1)]))) {
8821 			/* New more recent rack_tmit_time */
8822 			rack->r_ctl.rc_rack_tmit_time = (uint32_t)rsm->r_tim_lastsent[(rsm->r_rtr_cnt - 1)];
8823 			if (rack->r_ctl.rc_rack_tmit_time == 0)
8824 				rack->r_ctl.rc_rack_tmit_time = 1;
8825 			rack->rc_rack_rtt = t;
8826 		}
8827 		return (1);
8828 	}
8829 	/*
8830 	 * We clear the soft/rxtshift since we got an ack.
8831 	 * There is no assurance we will call the commit() function
8832 	 * so we need to clear these to avoid incorrect handling.
8833 	 */
8834 	tp->t_rxtshift = 0;
8835 	RACK_TCPT_RANGESET(tp->t_rxtcur, RACK_REXMTVAL(tp),
8836 		      rack_rto_min, rack_rto_max, rack->r_ctl.timer_slop);
8837 	tp->t_softerror = 0;
8838 	if (to && (to->to_flags & TOF_TS) &&
8839 	    (ack_type == CUM_ACKED) &&
8840 	    (to->to_tsecr) &&
8841 	    ((rsm->r_flags & RACK_OVERMAX) == 0)) {
8842 		/*
8843 		 * Now which timestamp does it match? In this block the ACK
8844 		 * must be coming from a previous transmission.
8845 		 */
8846 		for (i = 0; i < rsm->r_rtr_cnt; i++) {
8847 			if (rack_ts_to_msec(rsm->r_tim_lastsent[i]) == to->to_tsecr) {
8848 				t = cts - (uint32_t)rsm->r_tim_lastsent[i];
8849 				if ((int)t <= 0)
8850 					t = 1;
8851 				if (CC_ALGO(tp)->rttsample != NULL) {
8852 					/*
8853 					 * Kick the RTT to the CC, here
8854 					 * we lie a bit in that we know the
8855 					 * retransmission is correct even though
8856 					 * we retransmitted. This is because
8857 					 * we match the timestamps.
8858 					 */
8859 					if (TSTMP_GT(tcp_tv_to_usec(&rack->r_ctl.act_rcv_time), rsm->r_tim_lastsent[i]))
8860 						us_rtt = tcp_tv_to_usec(&rack->r_ctl.act_rcv_time) - (uint32_t)rsm->r_tim_lastsent[i];
8861 					else
8862 						us_rtt = tcp_get_usecs(NULL) - (uint32_t)rsm->r_tim_lastsent[i];
8863 					CC_ALGO(tp)->rttsample(&tp->t_ccv, us_rtt, 1, rsm->r_fas);
8864 				}
8865 				if ((i + 1) < rsm->r_rtr_cnt) {
8866 					/*
8867 					 * The peer ack'd from our previous
8868 					 * transmission. We have a spurious
8869 					 * retransmission and thus we dont
8870 					 * want to update our rack_rtt.
8871 					 *
8872 					 * Hmm should there be a CC revert here?
8873 					 *
8874 					 */
8875 					return (0);
8876 				}
8877 				if (!tp->t_rttlow || tp->t_rttlow > t)
8878 					tp->t_rttlow = t;
8879 				if (!rack->r_ctl.rc_rack_min_rtt || SEQ_LT(t, rack->r_ctl.rc_rack_min_rtt)) {
8880 					rack->r_ctl.rc_rack_min_rtt = t;
8881 					if (rack->r_ctl.rc_rack_min_rtt == 0) {
8882 						rack->r_ctl.rc_rack_min_rtt = 1;
8883 					}
8884 				}
8885 				if ((rack->r_ctl.rc_rack_tmit_time == 0) ||
8886 				    (SEQ_LT(rack->r_ctl.rc_rack_tmit_time,
8887 					    (uint32_t)rsm->r_tim_lastsent[(rsm->r_rtr_cnt - 1)]))) {
8888 					/* New more recent rack_tmit_time */
8889 					rack->r_ctl.rc_rack_tmit_time = (uint32_t)rsm->r_tim_lastsent[(rsm->r_rtr_cnt - 1)];
8890 					if (rack->r_ctl.rc_rack_tmit_time == 0)
8891 						rack->r_ctl.rc_rack_tmit_time = 1;
8892 					rack->rc_rack_rtt = t;
8893 				}
8894 				rack_log_rtt_sample_calc(rack, t, (uint32_t)rsm->r_tim_lastsent[i], cts, 3);
8895 				tcp_rack_xmit_timer(rack, t + 1, len_acked, t, 0, rsm,
8896 						    rsm->r_rtr_cnt);
8897 				return (1);
8898 			}
8899 		}
8900 		/* If we are logging log out the sendmap */
8901 		if (tcp_bblogging_on(rack->rc_tp)) {
8902 			for (i = 0; i < rsm->r_rtr_cnt; i++) {
8903 				rack_log_rtt_sendmap(rack, i, rsm->r_tim_lastsent[i], to->to_tsecr);
8904 			}
8905 		}
8906 		goto ts_not_found;
8907 	} else {
8908 		/*
8909 		 * Ok its a SACK block that we retransmitted. or a windows
8910 		 * machine without timestamps. We can tell nothing from the
8911 		 * time-stamp since its not there or the time the peer last
8912 		 * received a segment that moved forward its cum-ack point.
8913 		 */
8914 ts_not_found:
8915 		i = rsm->r_rtr_cnt - 1;
8916 		t = cts - (uint32_t)rsm->r_tim_lastsent[i];
8917 		if ((int)t <= 0)
8918 			t = 1;
8919 		if (rack->r_ctl.rc_rack_min_rtt && SEQ_LT(t, rack->r_ctl.rc_rack_min_rtt)) {
8920 			/*
8921 			 * We retransmitted and the ack came back in less
8922 			 * than the smallest rtt we have observed. We most
8923 			 * likely did an improper retransmit as outlined in
8924 			 * 6.2 Step 2 point 2 in the rack-draft so we
8925 			 * don't want to update our rack_rtt. We in
8926 			 * theory (in future) might want to think about reverting our
8927 			 * cwnd state but we won't for now.
8928 			 */
8929 			return (0);
8930 		} else if (rack->r_ctl.rc_rack_min_rtt) {
8931 			/*
8932 			 * We retransmitted it and the retransmit did the
8933 			 * job.
8934 			 */
8935 			if (!rack->r_ctl.rc_rack_min_rtt ||
8936 			    SEQ_LT(t, rack->r_ctl.rc_rack_min_rtt)) {
8937 				rack->r_ctl.rc_rack_min_rtt = t;
8938 				if (rack->r_ctl.rc_rack_min_rtt == 0) {
8939 					rack->r_ctl.rc_rack_min_rtt = 1;
8940 				}
8941 			}
8942 			if ((rack->r_ctl.rc_rack_tmit_time == 0) ||
8943 			    (SEQ_LT(rack->r_ctl.rc_rack_tmit_time,
8944 				    (uint32_t)rsm->r_tim_lastsent[i]))) {
8945 				/* New more recent rack_tmit_time */
8946 				rack->r_ctl.rc_rack_tmit_time = (uint32_t)rsm->r_tim_lastsent[i];
8947 				if (rack->r_ctl.rc_rack_tmit_time == 0)
8948 					rack->r_ctl.rc_rack_tmit_time = 1;
8949 				rack->rc_rack_rtt = t;
8950 			}
8951 			return (1);
8952 		}
8953 	}
8954 	return (0);
8955 }
8956 
8957 /*
8958  * Mark the SACK_PASSED flag on all entries prior to rsm send wise.
8959  */
8960 static void
8961 rack_log_sack_passed(struct tcpcb *tp,
8962     struct tcp_rack *rack, struct rack_sendmap *rsm, uint32_t cts, int line)
8963 {
8964 	struct rack_sendmap *nrsm;
8965 	uint32_t thresh;
8966 
8967 	/* Get our rxt threshold for lost consideration */
8968 	thresh = rack_calc_thresh_rack(rack, rack_grab_rtt(tp, rack), cts, __LINE__, 0);
8969 	/* Now start looking at rsm's */
8970 	nrsm = rsm;
8971 	TAILQ_FOREACH_REVERSE_FROM(nrsm, &rack->r_ctl.rc_tmap,
8972 	    rack_head, r_tnext) {
8973 		if (nrsm == rsm) {
8974 			/* Skip original segment he is acked */
8975 			continue;
8976 		}
8977 		if (nrsm->r_flags & RACK_ACKED) {
8978 			/*
8979 			 * Skip ack'd segments, though we
8980 			 * should not see these, since tmap
8981 			 * should not have ack'd segments.
8982 			 */
8983 			continue;
8984 		}
8985 		if (nrsm->r_flags & RACK_RWND_COLLAPSED) {
8986 			/*
8987 			 * If the peer dropped the rwnd on
8988 			 * these then we don't worry about them.
8989 			 */
8990 			continue;
8991 		}
8992 		/* Check lost state */
8993 		if ((nrsm->r_flags & RACK_WAS_LOST) == 0) {
8994 			uint32_t exp;
8995 
8996 			exp = ((uint32_t)rsm->r_tim_lastsent[(rsm->r_rtr_cnt - 1)]) + thresh;
8997 			if (TSTMP_LT(exp, cts) || (exp == cts)) {
8998 				/* We consider it lost */
8999 				nrsm->r_flags |= RACK_WAS_LOST;
9000 				rack->r_ctl.rc_considered_lost += nrsm->r_end - nrsm->r_start;
9001 			}
9002 		}
9003 		if (nrsm->r_flags & RACK_SACK_PASSED) {
9004 			/*
9005 			 * We found one that is already marked
9006 			 * passed, we have been here before and
9007 			 * so all others below this are marked.
9008 			 */
9009 			break;
9010 		}
9011 		rack_log_dsack_event(rack, 12, __LINE__, nrsm->r_start, nrsm->r_end);
9012 		nrsm->r_flags |= RACK_SACK_PASSED;
9013 		nrsm->r_flags &= ~RACK_WAS_SACKPASS;
9014 	}
9015 }
9016 
9017 static void
9018 rack_need_set_test(struct tcpcb *tp,
9019 		   struct tcp_rack *rack,
9020 		   struct rack_sendmap *rsm,
9021 		   tcp_seq th_ack,
9022 		   int line,
9023 		   int use_which)
9024 {
9025 	struct rack_sendmap *s_rsm;
9026 
9027 	if ((tp->t_flags & TF_GPUTINPROG) &&
9028 	    SEQ_GEQ(rsm->r_end, tp->gput_seq)) {
9029 		/*
9030 		 * We were app limited, and this ack
9031 		 * butts up or goes beyond the point where we want
9032 		 * to start our next measurement. We need
9033 		 * to record the new gput_ts as here and
9034 		 * possibly update the start sequence.
9035 		 */
9036 		uint32_t seq, ts;
9037 
9038 		if (rsm->r_rtr_cnt > 1) {
9039 			/*
9040 			 * This is a retransmit, can we
9041 			 * really make any assessment at this
9042 			 * point?  We are not really sure of
9043 			 * the timestamp, is it this or the
9044 			 * previous transmission?
9045 			 *
9046 			 * Lets wait for something better that
9047 			 * is not retransmitted.
9048 			 */
9049 			return;
9050 		}
9051 		seq = tp->gput_seq;
9052 		ts = tp->gput_ts;
9053 		rack->app_limited_needs_set = 0;
9054 		tp->gput_ts = tcp_tv_to_usec(&rack->r_ctl.act_rcv_time);
9055 		/* Do we start at a new end? */
9056 		if ((use_which == RACK_USE_BEG) &&
9057 		    SEQ_GEQ(rsm->r_start, tp->gput_seq)) {
9058 			/*
9059 			 * When we get an ACK that just eats
9060 			 * up some of the rsm, we set RACK_USE_BEG
9061 			 * since whats at r_start (i.e. th_ack)
9062 			 * is left unacked and thats where the
9063 			 * measurement now starts.
9064 			 */
9065 			tp->gput_seq = rsm->r_start;
9066 		}
9067 		if ((use_which == RACK_USE_END) &&
9068 		    SEQ_GEQ(rsm->r_end, tp->gput_seq)) {
9069 			/*
9070 			 * We use the end when the cumack
9071 			 * is moving forward and completely
9072 			 * deleting the rsm passed so basically
9073 			 * r_end holds th_ack.
9074 			 *
9075 			 * For SACK's we also want to use the end
9076 			 * since this piece just got sacked and
9077 			 * we want to target anything after that
9078 			 * in our measurement.
9079 			 */
9080 			tp->gput_seq = rsm->r_end;
9081 		}
9082 		if (use_which == RACK_USE_END_OR_THACK) {
9083 			/*
9084 			 * special case for ack moving forward,
9085 			 * not a sack, we need to move all the
9086 			 * way up to where this ack cum-ack moves
9087 			 * to.
9088 			 */
9089 			if (SEQ_GT(th_ack, rsm->r_end))
9090 				tp->gput_seq = th_ack;
9091 			else
9092 				tp->gput_seq = rsm->r_end;
9093 		}
9094 		if (SEQ_LT(tp->gput_seq, tp->snd_max))
9095 			s_rsm = tqhash_find(rack->r_ctl.tqh, tp->gput_seq);
9096 		else
9097 			s_rsm = NULL;
9098 		/*
9099 		 * Pick up the correct send time if we can the rsm passed in
9100 		 * may be equal to s_rsm if the RACK_USE_BEG was set. For the other
9101 		 * two cases (RACK_USE_THACK or RACK_USE_END) most likely we will
9102 		 * find a different seq i.e. the next send up.
9103 		 *
9104 		 * If that has not been sent, s_rsm will be NULL and we must
9105 		 * arrange it so this function will get called again by setting
9106 		 * app_limited_needs_set.
9107 		 */
9108 		if (s_rsm)
9109 			rack->r_ctl.rc_gp_output_ts = s_rsm->r_tim_lastsent[0];
9110 		else {
9111 			/* If we hit here we have to have *not* sent tp->gput_seq */
9112 			rack->r_ctl.rc_gp_output_ts = rsm->r_tim_lastsent[0];
9113 			/* Set it up so we will go through here again */
9114 			rack->app_limited_needs_set = 1;
9115 		}
9116 		if (SEQ_GT(tp->gput_seq, tp->gput_ack)) {
9117 			/*
9118 			 * We moved beyond this guy's range, re-calculate
9119 			 * the new end point.
9120 			 */
9121 			if (rack->rc_gp_filled == 0) {
9122 				tp->gput_ack = tp->gput_seq + max(rc_init_window(rack), (MIN_GP_WIN * ctf_fixed_maxseg(tp)));
9123 			} else {
9124 				tp->gput_ack = tp->gput_seq + rack_get_measure_window(tp, rack);
9125 			}
9126 		}
9127 		/*
9128 		 * We are moving the goal post, we may be able to clear the
9129 		 * measure_saw_probe_rtt flag.
9130 		 */
9131 		if ((rack->in_probe_rtt == 0) &&
9132 		    (rack->measure_saw_probe_rtt) &&
9133 		    (SEQ_GEQ(tp->gput_seq, rack->r_ctl.rc_probertt_sndmax_atexit)))
9134 			rack->measure_saw_probe_rtt = 0;
9135 		rack_log_pacing_delay_calc(rack, ts, tp->gput_ts,
9136 					   seq, tp->gput_seq,
9137 					   (((uint64_t)rack->r_ctl.rc_app_limited_cnt << 32) |
9138 					    (uint64_t)rack->r_ctl.rc_gp_output_ts),
9139 					   5, line, NULL, 0);
9140 		if (rack->rc_gp_filled &&
9141 		    ((tp->gput_ack - tp->gput_seq) <
9142 		     max(rc_init_window(rack), (MIN_GP_WIN *
9143 						ctf_fixed_maxseg(tp))))) {
9144 			uint32_t ideal_amount;
9145 
9146 			ideal_amount = rack_get_measure_window(tp, rack);
9147 			if (ideal_amount > sbavail(&tptosocket(tp)->so_snd)) {
9148 				/*
9149 				 * There is no sense of continuing this measurement
9150 				 * because its too small to gain us anything we
9151 				 * trust. Skip it and that way we can start a new
9152 				 * measurement quicker.
9153 				 */
9154 				tp->t_flags &= ~TF_GPUTINPROG;
9155 				rack_log_pacing_delay_calc(rack, tp->gput_ack, tp->gput_seq,
9156 							   0, 0,
9157 							   (((uint64_t)rack->r_ctl.rc_app_limited_cnt << 32) |
9158 							    (uint64_t)rack->r_ctl.rc_gp_output_ts),
9159 							   6, __LINE__, NULL, 0);
9160 			} else {
9161 				/*
9162 				 * Reset the window further out.
9163 				 */
9164 				tp->gput_ack = tp->gput_seq + ideal_amount;
9165 			}
9166 		}
9167 		rack_tend_gp_marks(tp, rack);
9168 		rack_log_gpset(rack, tp->gput_ack, 0, 0, line, 2, rsm);
9169 	}
9170 }
9171 
9172 static inline int
9173 is_rsm_inside_declared_tlp_block(struct tcp_rack *rack, struct rack_sendmap *rsm)
9174 {
9175 	if (SEQ_LT(rsm->r_end, rack->r_ctl.last_tlp_acked_start)) {
9176 		/* Behind our TLP definition or right at */
9177 		return (0);
9178 	}
9179 	if (SEQ_GT(rsm->r_start, rack->r_ctl.last_tlp_acked_end)) {
9180 		/* The start is beyond or right at our end of TLP definition */
9181 		return (0);
9182 	}
9183 	/* It has to be a sub-part of the original TLP recorded */
9184 	return (1);
9185 }
9186 
9187 
9188 static int
9189 rack_check_reorder_ack(struct tcpcb *tp, struct tcp_rack *rack, struct rack_sendmap *rsm, int the_end, uint32_t cts, int can_exit_recovery, int line)
9190 {
9191 	if ((rack_rtt_divisor > 0) &&
9192 	    (rsm->r_rtr_cnt == 2) &&
9193 	    IN_RECOVERY(tp->t_flags) &&
9194 	    (rsm->r_flags & RACK_WAS_SACKPASS)){
9195 		uint32_t fractional, snt_to_ack;
9196 
9197 		fractional = (tp->t_srtt / rack_rtt_divisor);
9198 		if (fractional == 0)
9199 			fractional = 1;
9200 		snt_to_ack = cts - (uint32_t)rsm->r_tim_lastsent[(rsm->r_rtr_cnt - 1)];
9201 		if (snt_to_ack <= fractional) {
9202 			rack->r_ctl.rc_reorder_ts = cts;
9203 			KASSERT((rack->r_ctl.recovery_rxt_cnt >= (the_end - rsm->r_start)),
9204 				("rsm:%p rack:%p recovery_rxt_cnt would go negative recovery_rxt_cnt:%u sub:%u", rsm,  rack, rack->r_ctl.recovery_rxt_cnt, (the_end - rsm->r_start)));
9205 			rack->r_ctl.recovery_rxt_cnt -= (the_end - rsm->r_start);
9206 			rack_log_to_prr(rack, 18, rack->r_ctl.recovery_rxt_cnt, line);
9207 			if (can_exit_recovery && (rack->r_ctl.recovery_rxt_cnt == 0)) {
9208 				tp->snd_ssthresh = rack->r_ctl.rc_ssthresh_at_erec;
9209 				rack_exit_recovery(tp, rack, 4);
9210 				rack->r_might_revert = 0;
9211 				rack->r_ctl.retran_during_recovery = 0;
9212 				rack_log_to_prr(rack, 17, snt_to_ack, line);
9213 			}
9214 			return (1);
9215 		}
9216 	}
9217 	return (0);
9218 }
9219 
9220 static uint32_t
9221 rack_proc_sack_blk(struct tcpcb *tp, struct tcp_rack *rack, struct sackblk *sack,
9222 		   struct tcpopt *to, struct rack_sendmap **prsm, uint32_t cts,
9223 		   uint32_t segsiz)
9224 {
9225 	uint32_t start, end, changed = 0;
9226 	struct rack_sendmap stack_map;
9227 	struct rack_sendmap *rsm, *nrsm, *prev, *next;
9228 	int insret __diagused;
9229 	int32_t used_ref = 1;
9230 	int can_use_hookery = 0;
9231 	int prohibit_marking = 0;
9232 
9233 	start = sack->start;
9234 	end = sack->end;
9235 	rsm = *prsm;
9236 
9237 do_rest_ofb:
9238 	if ((rsm == NULL) ||
9239 	    (SEQ_LT(end, rsm->r_start)) ||
9240 	    (SEQ_GEQ(start, rsm->r_end)) ||
9241 	    (SEQ_LT(start, rsm->r_start))) {
9242 		/*
9243 		 * We are not in the right spot,
9244 		 * find the correct spot in the tree.
9245 		 */
9246 		used_ref = 0;
9247 		rsm = tqhash_find(rack->r_ctl.tqh, start);
9248 	}
9249 	if (rsm == NULL) {
9250 		/* TSNH */
9251 		goto out;
9252 	}
9253 	/* Ok we have an ACK for some piece of this rsm */
9254 	if (rsm->r_start != start) {
9255 		if ((rsm->r_flags & RACK_ACKED) == 0) {
9256 			/*
9257 			 * Before any splitting or hookery is
9258 			 * done is it a TLP of interest i.e. rxt?
9259 			 */
9260 			if ((rsm->r_flags & RACK_TLP) &&
9261 			    (rsm->r_rtr_cnt > 1)) {
9262 				/*
9263 				 * We are splitting a rxt TLP, check
9264 				 * if we need to save off the start/end
9265 				 */
9266 				if (rack->rc_last_tlp_acked_set &&
9267 				    (is_rsm_inside_declared_tlp_block(rack, rsm))) {
9268 					/*
9269 					 * We already turned this on since we are inside
9270 					 * the previous one was a partially sack now we
9271 					 * are getting another one (maybe all of it).
9272 					 *
9273 					 */
9274 					rack_log_dsack_event(rack, 10, __LINE__, rsm->r_start, rsm->r_end);
9275 					/*
9276 					 * Lets make sure we have all of it though.
9277 					 */
9278 					if (SEQ_LT(rsm->r_start, rack->r_ctl.last_tlp_acked_start)) {
9279 						rack->r_ctl.last_tlp_acked_start = rsm->r_start;
9280 						rack_log_dsack_event(rack, 11, __LINE__, rack->r_ctl.last_tlp_acked_start,
9281 								     rack->r_ctl.last_tlp_acked_end);
9282 					}
9283 					if (SEQ_GT(rsm->r_end, rack->r_ctl.last_tlp_acked_end)) {
9284 						rack->r_ctl.last_tlp_acked_end = rsm->r_end;
9285 						rack_log_dsack_event(rack, 11, __LINE__, rack->r_ctl.last_tlp_acked_start,
9286 								     rack->r_ctl.last_tlp_acked_end);
9287 					}
9288 				} else {
9289 					rack->r_ctl.last_tlp_acked_start = rsm->r_start;
9290 					rack->r_ctl.last_tlp_acked_end = rsm->r_end;
9291 					rack->rc_last_tlp_past_cumack = 0;
9292 					rack->rc_last_tlp_acked_set = 1;
9293 					rack_log_dsack_event(rack, 8, __LINE__, rsm->r_start, rsm->r_end);
9294 				}
9295 			}
9296 			/**
9297 			 * Need to split this in two pieces the before and after,
9298 			 * the before remains in the map, the after must be
9299 			 * added. In other words we have:
9300 			 * rsm        |--------------|
9301 			 * sackblk        |------->
9302 			 * rsm will become
9303 			 *     rsm    |---|
9304 			 * and nrsm will be  the sacked piece
9305 			 *     nrsm       |----------|
9306 			 *
9307 			 * But before we start down that path lets
9308 			 * see if the sack spans over on top of
9309 			 * the next guy and it is already sacked.
9310 			 *
9311 			 */
9312 			/*
9313 			 * Hookery can only be used if the two entries
9314 			 * are in the same bucket and neither one of
9315 			 * them staddle the bucket line.
9316 			 */
9317 			next = tqhash_next(rack->r_ctl.tqh, rsm);
9318 			if (next &&
9319 			    (rsm->bindex == next->bindex) &&
9320 			    ((rsm->r_flags & RACK_STRADDLE) == 0) &&
9321 			    ((next->r_flags & RACK_STRADDLE) == 0) &&
9322 			    ((rsm->r_flags & RACK_WAS_SACKPASS) == 0) &&
9323 			    ((next->r_flags & RACK_WAS_SACKPASS) == 0) &&
9324 			    ((rsm->r_flags & RACK_IS_PCM) == 0) &&
9325 			    ((next->r_flags & RACK_IS_PCM) == 0) &&
9326 			    (rsm->r_flags & RACK_IN_GP_WIN) &&
9327 			    (next->r_flags & RACK_IN_GP_WIN))
9328 				can_use_hookery = 1;
9329 			else
9330 				can_use_hookery = 0;
9331 			if (next && can_use_hookery &&
9332 			    (next->r_flags & RACK_ACKED) &&
9333 			    SEQ_GEQ(end, next->r_start)) {
9334 				/**
9335 				 * So the next one is already acked, and
9336 				 * we can thus by hookery use our stack_map
9337 				 * to reflect the piece being sacked and
9338 				 * then adjust the two tree entries moving
9339 				 * the start and ends around. So we start like:
9340 				 *  rsm     |------------|             (not-acked)
9341 				 *  next                 |-----------| (acked)
9342 				 *  sackblk        |-------->
9343 				 *  We want to end like so:
9344 				 *  rsm     |------|                   (not-acked)
9345 				 *  next           |-----------------| (acked)
9346 				 *  nrsm           |-----|
9347 				 * Where nrsm is a temporary stack piece we
9348 				 * use to update all the gizmos.
9349 				 */
9350 				/* Copy up our fudge block */
9351 				nrsm = &stack_map;
9352 				memcpy(nrsm, rsm, sizeof(struct rack_sendmap));
9353 				/* Now adjust our tree blocks */
9354 				tqhash_update_end(rack->r_ctl.tqh, rsm, start);
9355 				next->r_start = start;
9356  				rsm->r_flags |= RACK_SHUFFLED;
9357 				next->r_flags |= RACK_SHUFFLED;
9358 				/* Now we must adjust back where next->m is */
9359 				rack_setup_offset_for_rsm(rack, rsm, next);
9360 				/*
9361 				 * Which timestamp do we keep? It is rather
9362 				 * important in GP measurements to have the
9363 				 * accurate end of the send window.
9364 				 *
9365 				 * We keep the largest value, which is the newest
9366 				 * send. We do this in case a segment that is
9367 				 * joined together and not part of a GP estimate
9368 				 * later gets expanded into the GP estimate.
9369 				 *
9370 				 * We prohibit the merging of unlike kinds i.e.
9371 				 * all pieces that are in the GP estimate can be
9372 				 * merged and all pieces that are not in a GP estimate
9373 				 * can be merged, but not disimilar pieces. Combine
9374 				 * this with taking the highest here and we should
9375 				 * be ok unless of course the client reneges. Then
9376 				 * all bets are off.
9377 				 */
9378 				if (next->r_tim_lastsent[(next->r_rtr_cnt-1)] <
9379 				    nrsm->r_tim_lastsent[(nrsm->r_rtr_cnt-1)])
9380 					next->r_tim_lastsent[(next->r_rtr_cnt-1)] = nrsm->r_tim_lastsent[(nrsm->r_rtr_cnt-1)];
9381 				/*
9382 				 * And we must keep the newest ack arrival time.
9383 				 */
9384 				if (next->r_ack_arrival <
9385 				    rack_to_usec_ts(&rack->r_ctl.act_rcv_time))
9386 					next->r_ack_arrival = rack_to_usec_ts(&rack->r_ctl.act_rcv_time);
9387 
9388 
9389 				/* We don't need to adjust rsm, it did not change */
9390 				/* Clear out the dup ack count of the remainder */
9391 				rsm->r_dupack = 0;
9392 				rsm->r_just_ret = 0;
9393 				rack_log_retran_reason(rack, rsm, __LINE__, 0, 2);
9394 				/* Now lets make sure our fudge block is right */
9395 				nrsm->r_start = start;
9396 				/* Check if the ack was too soon i.e. reordering + ack arrives too quickly */
9397 				prohibit_marking = rack_check_reorder_ack(tp, rack, nrsm, nrsm->r_end, cts, 0, __LINE__);
9398 				/* Now lets update all the stats and such */
9399 				rack_update_rtt(tp, rack, nrsm, to, cts, SACKED, 0);
9400 				if (rack->app_limited_needs_set)
9401 					rack_need_set_test(tp, rack, nrsm, tp->snd_una, __LINE__, RACK_USE_END);
9402 				changed += (nrsm->r_end - nrsm->r_start);
9403 				rack->r_ctl.rc_sacked += (nrsm->r_end - nrsm->r_start);
9404 				if (rsm->r_flags & RACK_WAS_LOST) {
9405 					int my_chg;
9406 
9407 					/*
9408 					 * Note here we do not use our rack_mark_nolonger_lost() function
9409 					 * since we are moving our data pointer around and the
9410 					 * ack'ed side is already not considered lost.
9411 					 */
9412 					my_chg = (nrsm->r_end - nrsm->r_start);
9413 					KASSERT((rack->r_ctl.rc_considered_lost >= my_chg),
9414 						("rsm:%p rack:%p rc_considered_lost goes negative", rsm,  rack));
9415 					if (my_chg <= rack->r_ctl.rc_considered_lost)
9416 						rack->r_ctl.rc_considered_lost -= my_chg;
9417 					else
9418 						rack->r_ctl.rc_considered_lost = 0;
9419 				}
9420 				if (nrsm->r_flags & RACK_SACK_PASSED) {
9421 					rack->r_ctl.rc_reorder_ts = cts;
9422 					if (rack->r_ctl.rc_reorder_ts == 0)
9423 						rack->r_ctl.rc_reorder_ts = 1;
9424 				}
9425 				/*
9426 				 * Now we want to go up from rsm (the
9427 				 * one left un-acked) to the next one
9428 				 * in the tmap. We do this so when
9429 				 * we walk backwards we include marking
9430 				 * sack-passed on rsm (The one passed in
9431 				 * is skipped since it is generally called
9432 				 * on something sacked before removing it
9433 				 * from the tmap).
9434 				 */
9435 				if (rsm->r_in_tmap) {
9436 					nrsm = TAILQ_NEXT(rsm, r_tnext);
9437 					/*
9438 					 * Now that we have the next
9439 					 * one walk backwards from there.
9440 					 */
9441 					if (nrsm && nrsm->r_in_tmap && (prohibit_marking == 0))
9442 						rack_log_sack_passed(tp, rack, nrsm, cts, __LINE__);
9443 				}
9444 				/* Now are we done? */
9445 				if (SEQ_LT(end, next->r_end) ||
9446 				    (end == next->r_end)) {
9447 					/* Done with block */
9448 					goto out;
9449 				}
9450 				rack_log_map_chg(tp, rack, &stack_map, rsm, next, MAP_SACK_M1, end, __LINE__);
9451 				/* Postion for the next block */
9452 				start = next->r_end;
9453 				rsm = tqhash_next(rack->r_ctl.tqh, next);
9454 				if (rsm == NULL)
9455 					goto out;
9456 			} else {
9457 				/**
9458 				 * We can't use any hookery here, so we
9459 				 * need to split the map. We enter like
9460 				 * so:
9461 				 *  rsm      |--------|
9462 				 *  sackblk       |----->
9463 				 * We will add the new block nrsm and
9464 				 * that will be the new portion, and then
9465 				 * fall through after reseting rsm. So we
9466 				 * split and look like this:
9467 				 *  rsm      |----|
9468 				 *  sackblk       |----->
9469 				 *  nrsm          |---|
9470 				 * We then fall through reseting
9471 				 * rsm to nrsm, so the next block
9472 				 * picks it up.
9473 				 */
9474 				nrsm = rack_alloc_limit(rack, RACK_LIMIT_TYPE_SPLIT);
9475 				if (nrsm == NULL) {
9476 					/*
9477 					 * failed XXXrrs what can we do but loose the sack
9478 					 * info?
9479 					 */
9480 					goto out;
9481 				}
9482 				rack_clone_rsm(rack, nrsm, rsm, start);
9483 				rsm->r_just_ret = 0;
9484 #ifndef INVARIANTS
9485 				(void)tqhash_insert(rack->r_ctl.tqh, nrsm);
9486 #else
9487 				if ((insret = tqhash_insert(rack->r_ctl.tqh, nrsm)) != 0) {
9488 					panic("Insert in tailq_hash of %p fails ret:%d rack:%p rsm:%p",
9489 					      nrsm, insret, rack, rsm);
9490 				}
9491 #endif
9492 				if (rsm->r_in_tmap) {
9493 					TAILQ_INSERT_AFTER(&rack->r_ctl.rc_tmap, rsm, nrsm, r_tnext);
9494 					nrsm->r_in_tmap = 1;
9495 				}
9496 				rack_log_map_chg(tp, rack, NULL, rsm, nrsm, MAP_SACK_M2, end, __LINE__);
9497 				rsm->r_flags &= (~RACK_HAS_FIN);
9498 				/* Check if the ack was too soon i.e. reordering + ack arrives too quickly */
9499 				prohibit_marking = rack_check_reorder_ack(tp, rack, nrsm, nrsm->r_end, cts, 0, __LINE__);
9500 				/* Position us to point to the new nrsm that starts the sack blk */
9501 				rsm = nrsm;
9502 			}
9503 		} else {
9504 			/* Already sacked this piece */
9505 			if (end == rsm->r_end) {
9506 				/* Done with block */
9507 				rsm = tqhash_next(rack->r_ctl.tqh, rsm);
9508 				goto out;
9509 			} else if (SEQ_LT(end, rsm->r_end)) {
9510 				/* A partial sack to a already sacked block */
9511 				rsm = tqhash_next(rack->r_ctl.tqh, rsm);
9512 				goto out;
9513 			} else {
9514 				/*
9515 				 * The end goes beyond this guy
9516 				 * reposition the start to the
9517 				 * next block.
9518 				 */
9519 				start = rsm->r_end;
9520 				rsm = tqhash_next(rack->r_ctl.tqh, rsm);
9521 				if (rsm == NULL)
9522 					goto out;
9523 			}
9524 		}
9525 	}
9526 	if (SEQ_GEQ(end, rsm->r_end)) {
9527 		/**
9528 		 * The end of this block is either beyond this guy or right
9529 		 * at this guy. I.e.:
9530 		 *  rsm ---                 |-----|
9531 		 *  end                     |-----|
9532 		 *  <or>
9533 		 *  end                     |---------|
9534 		 */
9535 		if ((rsm->r_flags & RACK_ACKED) == 0) {
9536 			/*
9537 			 * Is it a TLP of interest?
9538 			 */
9539 			if ((rsm->r_flags & RACK_TLP) &&
9540 			    (rsm->r_rtr_cnt > 1)) {
9541 				/*
9542 				 * We are splitting a rxt TLP, check
9543 				 * if we need to save off the start/end
9544 				 */
9545 				if (rack->rc_last_tlp_acked_set &&
9546 				    (is_rsm_inside_declared_tlp_block(rack, rsm))) {
9547 					/*
9548 					 * We already turned this on since we are inside
9549 					 * the previous one was a partially sack now we
9550 					 * are getting another one (maybe all of it).
9551 					 */
9552 					rack_log_dsack_event(rack, 10, __LINE__, rsm->r_start, rsm->r_end);
9553 					/*
9554 					 * Lets make sure we have all of it though.
9555 					 */
9556 					if (SEQ_LT(rsm->r_start, rack->r_ctl.last_tlp_acked_start)) {
9557 						rack->r_ctl.last_tlp_acked_start = rsm->r_start;
9558 						rack_log_dsack_event(rack, 11, __LINE__, rack->r_ctl.last_tlp_acked_start,
9559 								     rack->r_ctl.last_tlp_acked_end);
9560 					}
9561 					if (SEQ_GT(rsm->r_end, rack->r_ctl.last_tlp_acked_end)) {
9562 						rack->r_ctl.last_tlp_acked_end = rsm->r_end;
9563 						rack_log_dsack_event(rack, 11, __LINE__, rack->r_ctl.last_tlp_acked_start,
9564 								     rack->r_ctl.last_tlp_acked_end);
9565 					}
9566 				} else {
9567 					rack->r_ctl.last_tlp_acked_start = rsm->r_start;
9568 					rack->r_ctl.last_tlp_acked_end = rsm->r_end;
9569 					rack->rc_last_tlp_past_cumack = 0;
9570 					rack->rc_last_tlp_acked_set = 1;
9571 					rack_log_dsack_event(rack, 8, __LINE__, rsm->r_start, rsm->r_end);
9572 				}
9573 			}
9574 			rack_update_rtt(tp, rack, rsm, to, cts, SACKED, 0);
9575 			changed += (rsm->r_end - rsm->r_start);
9576 			/* Check if the ack was too soon i.e. reordering + ack arrives too quickly */
9577 			prohibit_marking = rack_check_reorder_ack(tp, rack, rsm, rsm->r_end, cts, 0, __LINE__);
9578 			/* You get a count for acking a whole segment or more */
9579 			if (rsm->r_flags & RACK_WAS_LOST) {
9580 				/*
9581 				 * Here we can use the inline function since
9582 				 * the rsm is truly marked lost and now no longer lost.
9583 				 */
9584 				rack_mark_nolonger_lost(rack, rsm);
9585 			}
9586 			rack->r_ctl.rc_sacked += (rsm->r_end - rsm->r_start);
9587 			if (rsm->r_in_tmap && (prohibit_marking == 0)) /* should be true */
9588 				rack_log_sack_passed(tp, rack, rsm, cts, __LINE__);
9589 
9590 			/* Is Reordering occuring? */
9591 			if (rsm->r_flags & RACK_SACK_PASSED) {
9592 				rsm->r_flags &= ~RACK_SACK_PASSED;
9593 				rack->r_ctl.rc_reorder_ts = cts;
9594 				if (rack->r_ctl.rc_reorder_ts == 0)
9595 					rack->r_ctl.rc_reorder_ts = 1;
9596 			}
9597 			if (rack->app_limited_needs_set)
9598 				rack_need_set_test(tp, rack, rsm, tp->snd_una, __LINE__, RACK_USE_END);
9599 			rsm->r_ack_arrival = rack_to_usec_ts(&rack->r_ctl.act_rcv_time);
9600 			rsm->r_flags |= RACK_ACKED;
9601 			rack_update_pcm_ack(rack, 0, rsm->r_start, rsm->r_end);
9602 			if (rsm->r_in_tmap) {
9603 				TAILQ_REMOVE(&rack->r_ctl.rc_tmap, rsm, r_tnext);
9604 				rsm->r_in_tmap = 0;
9605 			}
9606 			rack_log_map_chg(tp, rack, NULL, rsm, NULL, MAP_SACK_M3, end, __LINE__);
9607 		}
9608 		if (end == rsm->r_end) {
9609 			/* This block only - done, setup for next */
9610 			goto out;
9611 		}
9612 		/*
9613 		 * There is more not coverend by this rsm move on
9614 		 * to the next block in the tail queue hash table.
9615 		 */
9616 		nrsm = tqhash_next(rack->r_ctl.tqh, rsm);
9617 		start = rsm->r_end;
9618 		rsm = nrsm;
9619 		if (rsm == NULL)
9620 			goto out;
9621 		goto do_rest_ofb;
9622 	}
9623 	/**
9624 	 * The end of this sack block is smaller than
9625 	 * our rsm i.e.:
9626 	 *  rsm ---                 |-----|
9627 	 *  end                     |--|
9628 	 */
9629 	if ((rsm->r_flags & RACK_ACKED) == 0) {
9630 		/*
9631 		 * Is it a TLP of interest?
9632 		 */
9633 		if ((rsm->r_flags & RACK_TLP) &&
9634 		    (rsm->r_rtr_cnt > 1)) {
9635 			/*
9636 			 * We are splitting a rxt TLP, check
9637 			 * if we need to save off the start/end
9638 			 */
9639 			if (rack->rc_last_tlp_acked_set &&
9640 			    (is_rsm_inside_declared_tlp_block(rack, rsm))) {
9641 				/*
9642 				 * We already turned this on since we are inside
9643 				 * the previous one was a partially sack now we
9644 				 * are getting another one (maybe all of it).
9645 				 */
9646 				rack_log_dsack_event(rack, 10, __LINE__, rsm->r_start, rsm->r_end);
9647 				/*
9648 				 * Lets make sure we have all of it though.
9649 				 */
9650 				if (SEQ_LT(rsm->r_start, rack->r_ctl.last_tlp_acked_start)) {
9651 					rack->r_ctl.last_tlp_acked_start = rsm->r_start;
9652 					rack_log_dsack_event(rack, 11, __LINE__, rack->r_ctl.last_tlp_acked_start,
9653 							     rack->r_ctl.last_tlp_acked_end);
9654 				}
9655 				if (SEQ_GT(rsm->r_end, rack->r_ctl.last_tlp_acked_end)) {
9656 					rack->r_ctl.last_tlp_acked_end = rsm->r_end;
9657 					rack_log_dsack_event(rack, 11, __LINE__, rack->r_ctl.last_tlp_acked_start,
9658 							     rack->r_ctl.last_tlp_acked_end);
9659 				}
9660 			} else {
9661 				rack->r_ctl.last_tlp_acked_start = rsm->r_start;
9662 				rack->r_ctl.last_tlp_acked_end = rsm->r_end;
9663 				rack->rc_last_tlp_past_cumack = 0;
9664 				rack->rc_last_tlp_acked_set = 1;
9665 				rack_log_dsack_event(rack, 8, __LINE__, rsm->r_start, rsm->r_end);
9666 			}
9667 		}
9668 		/*
9669 		 * Hookery can only be used if the two entries
9670 		 * are in the same bucket and neither one of
9671 		 * them staddle the bucket line.
9672 		 */
9673 		prev = tqhash_prev(rack->r_ctl.tqh, rsm);
9674 		if (prev &&
9675 		    (rsm->bindex == prev->bindex) &&
9676 		    ((rsm->r_flags & RACK_STRADDLE) == 0) &&
9677 		    ((prev->r_flags & RACK_STRADDLE) == 0) &&
9678 		    ((prev->r_flags & RACK_WAS_SACKPASS) == 0) &&
9679 		    ((rsm->r_flags & RACK_WAS_SACKPASS) == 0) &&
9680 		    ((rsm->r_flags & RACK_IS_PCM) == 0) &&
9681 		    ((prev->r_flags & RACK_IS_PCM) == 0) &&
9682 		    (rsm->r_flags & RACK_IN_GP_WIN) &&
9683 		    (prev->r_flags & RACK_IN_GP_WIN))
9684 			can_use_hookery = 1;
9685 		else
9686 			can_use_hookery = 0;
9687 		if (prev && can_use_hookery &&
9688 		    (prev->r_flags & RACK_ACKED)) {
9689 			/**
9690 			 * Goal, we want the right remainder of rsm to shrink
9691 			 * in place and span from (rsm->r_start = end) to rsm->r_end.
9692 			 * We want to expand prev to go all the way
9693 			 * to prev->r_end <- end.
9694 			 * so in the tree we have before:
9695 			 *   prev     |--------|         (acked)
9696 			 *   rsm               |-------| (non-acked)
9697 			 *   sackblk           |-|
9698 			 * We churn it so we end up with
9699 			 *   prev     |----------|       (acked)
9700 			 *   rsm                 |-----| (non-acked)
9701 			 *   nrsm              |-| (temporary)
9702 			 *
9703 			 * Note if either prev/rsm is a TLP we don't
9704 			 * do this.
9705 			 */
9706 			nrsm = &stack_map;
9707 			memcpy(nrsm, rsm, sizeof(struct rack_sendmap));
9708 			tqhash_update_end(rack->r_ctl.tqh, prev, end);
9709 			rsm->r_start = end;
9710 			rsm->r_flags |= RACK_SHUFFLED;
9711 			prev->r_flags |= RACK_SHUFFLED;
9712 			/* Now adjust nrsm (stack copy) to be
9713 			 * the one that is the small
9714 			 * piece that was "sacked".
9715 			 */
9716 			nrsm->r_end = end;
9717 			rsm->r_dupack = 0;
9718 			/* Check if the ack was too soon i.e. reordering + ack arrives too quickly */
9719 			prohibit_marking = rack_check_reorder_ack(tp, rack, nrsm, nrsm->r_end, cts, 0, __LINE__);
9720 			/*
9721 			 * Which timestamp do we keep? It is rather
9722 			 * important in GP measurements to have the
9723 			 * accurate end of the send window.
9724 			 *
9725 			 * We keep the largest value, which is the newest
9726 			 * send. We do this in case a segment that is
9727 			 * joined together and not part of a GP estimate
9728 			 * later gets expanded into the GP estimate.
9729 			 *
9730 			 * We prohibit the merging of unlike kinds i.e.
9731 			 * all pieces that are in the GP estimate can be
9732 			 * merged and all pieces that are not in a GP estimate
9733 			 * can be merged, but not disimilar pieces. Combine
9734 			 * this with taking the highest here and we should
9735 			 * be ok unless of course the client reneges. Then
9736 			 * all bets are off.
9737 			 */
9738 			if(prev->r_tim_lastsent[(prev->r_rtr_cnt-1)] <
9739 			   nrsm->r_tim_lastsent[(nrsm->r_rtr_cnt-1)]) {
9740 				prev->r_tim_lastsent[(prev->r_rtr_cnt-1)] = nrsm->r_tim_lastsent[(rsm->r_rtr_cnt-1)];
9741 			}
9742 			/*
9743 			 * And we must keep the newest ack arrival time.
9744 			 */
9745 
9746 			if(prev->r_ack_arrival <
9747 			   rack_to_usec_ts(&rack->r_ctl.act_rcv_time))
9748 				prev->r_ack_arrival = rack_to_usec_ts(&rack->r_ctl.act_rcv_time);
9749 
9750 			rack_log_retran_reason(rack, rsm, __LINE__, 0, 2);
9751 			/*
9752 			 * Now that the rsm has had its start moved forward
9753 			 * lets go ahead and get its new place in the world.
9754 			 */
9755 			rack_setup_offset_for_rsm(rack, prev, rsm);
9756 			/*
9757 			 * Now nrsm is our new little piece
9758 			 * that is acked (which was merged
9759 			 * to prev). Update the rtt and changed
9760 			 * based on that. Also check for reordering.
9761 			 */
9762 			rack_update_rtt(tp, rack, nrsm, to, cts, SACKED, 0);
9763 			if (rack->app_limited_needs_set)
9764 				rack_need_set_test(tp, rack, nrsm, tp->snd_una, __LINE__, RACK_USE_END);
9765 			changed += (nrsm->r_end - nrsm->r_start);
9766 			rack->r_ctl.rc_sacked += (nrsm->r_end - nrsm->r_start);
9767 			if (rsm->r_flags & RACK_WAS_LOST) {
9768 				int my_chg;
9769 
9770 				/*
9771 				 * Note here we are using hookery again so we can't
9772 				 * use our rack_mark_nolonger_lost() function.
9773 				 */
9774 				my_chg = (nrsm->r_end - nrsm->r_start);
9775 				KASSERT((rack->r_ctl.rc_considered_lost >= my_chg),
9776 					("rsm:%p rack:%p rc_considered_lost goes negative", rsm,  rack));
9777 				if (my_chg <= rack->r_ctl.rc_considered_lost)
9778 					rack->r_ctl.rc_considered_lost -= my_chg;
9779 				else
9780 					rack->r_ctl.rc_considered_lost = 0;
9781 			}
9782 			if (nrsm->r_flags & RACK_SACK_PASSED) {
9783 				rack->r_ctl.rc_reorder_ts = cts;
9784 				if (rack->r_ctl.rc_reorder_ts == 0)
9785 					rack->r_ctl.rc_reorder_ts = 1;
9786 			}
9787 			rack_log_map_chg(tp, rack, prev, &stack_map, rsm, MAP_SACK_M4, end, __LINE__);
9788 			rsm = prev;
9789 		} else {
9790 			/**
9791 			 * This is the case where our previous
9792 			 * block is not acked either, so we must
9793 			 * split the block in two.
9794 			 */
9795 			nrsm = rack_alloc_limit(rack, RACK_LIMIT_TYPE_SPLIT);
9796 			if (nrsm == NULL) {
9797 				/* failed rrs what can we do but loose the sack info? */
9798 				goto out;
9799 			}
9800 			if ((rsm->r_flags & RACK_TLP) &&
9801 			    (rsm->r_rtr_cnt > 1)) {
9802 				/*
9803 				 * We are splitting a rxt TLP, check
9804 				 * if we need to save off the start/end
9805 				 */
9806 				if (rack->rc_last_tlp_acked_set &&
9807 				    (is_rsm_inside_declared_tlp_block(rack, rsm))) {
9808 					/*
9809 					 * We already turned this on since this block is inside
9810 					 * the previous one was a partially sack now we
9811 					 * are getting another one (maybe all of it).
9812 					 */
9813 					rack_log_dsack_event(rack, 10, __LINE__, rsm->r_start, rsm->r_end);
9814 					/*
9815 					 * Lets make sure we have all of it though.
9816 					 */
9817 					if (SEQ_LT(rsm->r_start, rack->r_ctl.last_tlp_acked_start)) {
9818 						rack->r_ctl.last_tlp_acked_start = rsm->r_start;
9819 						rack_log_dsack_event(rack, 11, __LINE__, rack->r_ctl.last_tlp_acked_start,
9820 								     rack->r_ctl.last_tlp_acked_end);
9821 					}
9822 					if (SEQ_GT(rsm->r_end, rack->r_ctl.last_tlp_acked_end)) {
9823 						rack->r_ctl.last_tlp_acked_end = rsm->r_end;
9824 						rack_log_dsack_event(rack, 11, __LINE__, rack->r_ctl.last_tlp_acked_start,
9825 								     rack->r_ctl.last_tlp_acked_end);
9826 					}
9827 				} else {
9828 					rack->r_ctl.last_tlp_acked_start = rsm->r_start;
9829 					rack->r_ctl.last_tlp_acked_end = rsm->r_end;
9830 					rack->rc_last_tlp_acked_set = 1;
9831 					rack->rc_last_tlp_past_cumack = 0;
9832 					rack_log_dsack_event(rack, 8, __LINE__, rsm->r_start, rsm->r_end);
9833 				}
9834 			}
9835 			/**
9836 			 * In this case nrsm becomes
9837 			 * nrsm->r_start = end;
9838 			 * nrsm->r_end = rsm->r_end;
9839 			 * which is un-acked.
9840 			 * <and>
9841 			 * rsm->r_end = nrsm->r_start;
9842 			 * i.e. the remaining un-acked
9843 			 * piece is left on the left
9844 			 * hand side.
9845 			 *
9846 			 * So we start like this
9847 			 * rsm      |----------| (not acked)
9848 			 * sackblk  |---|
9849 			 * build it so we have
9850 			 * rsm      |---|         (acked)
9851 			 * nrsm         |------|  (not acked)
9852 			 */
9853 			rack_clone_rsm(rack, nrsm, rsm, end);
9854 			rsm->r_flags &= (~RACK_HAS_FIN);
9855 			rsm->r_just_ret = 0;
9856 #ifndef INVARIANTS
9857 			(void)tqhash_insert(rack->r_ctl.tqh, nrsm);
9858 #else
9859 			if ((insret = tqhash_insert(rack->r_ctl.tqh, nrsm)) != 0) {
9860 				panic("Insert in tailq_hash of %p fails ret:% rack:%p rsm:%p",
9861 				      nrsm, insret, rack, rsm);
9862 			}
9863 #endif
9864 			if (rsm->r_in_tmap) {
9865 				TAILQ_INSERT_AFTER(&rack->r_ctl.rc_tmap, rsm, nrsm, r_tnext);
9866 				nrsm->r_in_tmap = 1;
9867 			}
9868 			nrsm->r_dupack = 0;
9869 			/* Check if the ack was too soon i.e. reordering + ack arrives too quickly */
9870 			prohibit_marking = rack_check_reorder_ack(tp, rack, nrsm, nrsm->r_end, cts, 0, __LINE__);
9871 			rack_log_retran_reason(rack, nrsm, __LINE__, 0, 2);
9872 			rack_update_rtt(tp, rack, rsm, to, cts, SACKED, 0);
9873 			changed += (rsm->r_end - rsm->r_start);
9874 			if (rsm->r_flags & RACK_WAS_LOST) {
9875 				/*
9876 				 * Here it is safe to use our function.
9877 				 */
9878 				rack_mark_nolonger_lost(rack, rsm);
9879 			}
9880 			rack->r_ctl.rc_sacked += (rsm->r_end - rsm->r_start);
9881 
9882 			if (rsm->r_in_tmap && (prohibit_marking == 0)) /* should be true */
9883 				rack_log_sack_passed(tp, rack, rsm, cts, __LINE__);
9884 			/* Is Reordering occuring? */
9885 			if (rsm->r_flags & RACK_SACK_PASSED) {
9886 				rsm->r_flags &= ~RACK_SACK_PASSED;
9887 				rack->r_ctl.rc_reorder_ts = cts;
9888 				if (rack->r_ctl.rc_reorder_ts == 0)
9889 					rack->r_ctl.rc_reorder_ts = 1;
9890 			}
9891 			if (rack->app_limited_needs_set)
9892 				rack_need_set_test(tp, rack, rsm, tp->snd_una, __LINE__, RACK_USE_END);
9893 			rsm->r_ack_arrival = rack_to_usec_ts(&rack->r_ctl.act_rcv_time);
9894 			rsm->r_flags |= RACK_ACKED;
9895 			rack_update_pcm_ack(rack, 0, rsm->r_start, rsm->r_end);
9896 			rack_log_map_chg(tp, rack, NULL, rsm, nrsm, MAP_SACK_M5, end, __LINE__);
9897 			if (rsm->r_in_tmap) {
9898 				TAILQ_REMOVE(&rack->r_ctl.rc_tmap, rsm, r_tnext);
9899 				rsm->r_in_tmap = 0;
9900 			}
9901 		}
9902 	}
9903 out:
9904 	if (rsm &&
9905 	    ((rsm->r_flags & RACK_TLP) == 0) &&
9906 	    (rsm->r_flags & RACK_ACKED)) {
9907 		/*
9908 		 * Now can we merge where we worked
9909 		 * with either the previous or
9910 		 * next block?
9911 		 */
9912 		next = tqhash_next(rack->r_ctl.tqh, rsm);
9913 		while (next) {
9914 			if (next->r_flags & RACK_TLP)
9915 				break;
9916 			/* Only allow merges between ones in or out of GP window */
9917 			if ((next->r_flags & RACK_IN_GP_WIN) &&
9918 			    ((rsm->r_flags & RACK_IN_GP_WIN) == 0)) {
9919 				break;
9920 			}
9921 			/* We can't merge retransmitted with sack-pass set */
9922 			if ((rsm->r_flags & RACK_WAS_SACKPASS) ||
9923 			    (next->r_flags & RACK_WAS_SACKPASS))
9924 				break;
9925 			if ((rsm->r_flags & RACK_IN_GP_WIN) &&
9926 			    ((next->r_flags & RACK_IN_GP_WIN) == 0)) {
9927 				break;
9928 			}
9929 			if (rsm->bindex != next->bindex)
9930 				break;
9931 			if (rsm->r_flags & RACK_STRADDLE)
9932 				break;
9933 			if (rsm->r_flags & RACK_IS_PCM)
9934 				break;
9935 			if (next->r_flags & RACK_STRADDLE)
9936 				break;
9937 			if (next->r_flags & RACK_IS_PCM)
9938 				break;
9939 			if (next->r_flags & RACK_ACKED) {
9940 				/* yep this and next can be merged */
9941 				rsm = rack_merge_rsm(rack, rsm, next);
9942 				next = tqhash_next(rack->r_ctl.tqh, rsm);
9943 			} else
9944 				break;
9945 		}
9946 		/* Now what about the previous? */
9947 		prev = tqhash_prev(rack->r_ctl.tqh, rsm);
9948 		while (prev) {
9949 			if (prev->r_flags & RACK_TLP)
9950 				break;
9951 			/* Only allow merges between ones in or out of GP window */
9952 			if ((prev->r_flags & RACK_IN_GP_WIN) &&
9953 			    ((rsm->r_flags & RACK_IN_GP_WIN) == 0)) {
9954 				break;
9955 			}
9956 			/* We can't merge retransmitted with sack-pass set */
9957 			if ((rsm->r_flags & RACK_WAS_SACKPASS) ||
9958 			    (prev->r_flags & RACK_WAS_SACKPASS))
9959 				break;
9960 			if ((rsm->r_flags & RACK_IN_GP_WIN) &&
9961 			    ((prev->r_flags & RACK_IN_GP_WIN) == 0)) {
9962 				break;
9963 			}
9964 			if (rsm->bindex != prev->bindex)
9965 				break;
9966 			if (rsm->r_flags & RACK_STRADDLE)
9967 				break;
9968 			if (rsm->r_flags & RACK_IS_PCM)
9969 				break;
9970 			if (prev->r_flags & RACK_STRADDLE)
9971 				break;
9972 			if (prev->r_flags & RACK_IS_PCM)
9973 				break;
9974 			if (prev->r_flags & RACK_ACKED) {
9975 				/* yep the previous and this can be merged */
9976 				rsm = rack_merge_rsm(rack, prev, rsm);
9977 				prev = tqhash_prev(rack->r_ctl.tqh, rsm);
9978 			} else
9979 				break;
9980 		}
9981 	}
9982 	if (used_ref == 0) {
9983 		counter_u64_add(rack_sack_proc_all, 1);
9984 	} else {
9985 		counter_u64_add(rack_sack_proc_short, 1);
9986 	}
9987 	/* Save off the next one for quick reference. */
9988 	nrsm = tqhash_find(rack->r_ctl.tqh, end);
9989 	*prsm = rack->r_ctl.rc_sacklast = nrsm;
9990 	return (changed);
9991 }
9992 
9993 static void inline
9994 rack_peer_reneges(struct tcp_rack *rack, struct rack_sendmap *rsm, tcp_seq th_ack)
9995 {
9996 	struct rack_sendmap *tmap;
9997 
9998 	tmap = NULL;
9999 	while (rsm && (rsm->r_flags & RACK_ACKED)) {
10000 		/* Its no longer sacked, mark it so */
10001 		rack->r_ctl.rc_sacked -= (rsm->r_end - rsm->r_start);
10002 #ifdef INVARIANTS
10003 		if (rsm->r_in_tmap) {
10004 			panic("rack:%p rsm:%p flags:0x%x in tmap?",
10005 			      rack, rsm, rsm->r_flags);
10006 		}
10007 #endif
10008 		rsm->r_flags &= ~(RACK_ACKED|RACK_SACK_PASSED|RACK_WAS_SACKPASS);
10009 		/* Rebuild it into our tmap */
10010 		if (tmap == NULL) {
10011 			TAILQ_INSERT_HEAD(&rack->r_ctl.rc_tmap, rsm, r_tnext);
10012 			tmap = rsm;
10013 		} else {
10014 			TAILQ_INSERT_AFTER(&rack->r_ctl.rc_tmap, tmap, rsm, r_tnext);
10015 			tmap = rsm;
10016 		}
10017 		tmap->r_in_tmap = 1;
10018 		rsm = tqhash_next(rack->r_ctl.tqh, rsm);
10019 	}
10020 	/*
10021 	 * Now lets possibly clear the sack filter so we start
10022 	 * recognizing sacks that cover this area.
10023 	 */
10024 	sack_filter_clear(&rack->r_ctl.rack_sf, th_ack);
10025 
10026 }
10027 
10028 
10029 static void inline
10030 rack_rsm_sender_update(struct tcp_rack *rack, struct tcpcb *tp, struct rack_sendmap *rsm, uint8_t from)
10031 {
10032 	/*
10033 	 * We look at advancing the end send time for our GP
10034 	 * measurement tracking only as the cumulative acknowledgment
10035 	 * moves forward. You might wonder about this, why not
10036 	 * at every transmission or retransmission within the
10037 	 * GP window update the rc_gp_cumack_ts? Well its rather
10038 	 * nuanced but basically the GP window *may* expand (as
10039 	 * it does below) or worse and harder to track it may shrink.
10040 	 *
10041 	 * This last makes it impossible to track at the time of
10042 	 * the send, since you may set forward your rc_gp_cumack_ts
10043 	 * when you send, because that send *is* in your currently
10044 	 * "guessed" window, but then it shrinks. Now which was
10045 	 * the send time of the last bytes in the window, by the
10046 	 * time you ask that question that part of the sendmap
10047 	 * is freed. So you don't know and you will have too
10048 	 * long of send window. Instead by updating the time
10049 	 * marker only when the cumack advances this assures us
10050 	 * that we will have only the sends in the window of our
10051 	 * GP measurement.
10052 	 *
10053 	 * Another complication from this is the
10054 	 * merging of sendmap entries. During SACK processing this
10055 	 * can happen to conserve the sendmap size. That breaks
10056 	 * everything down in tracking the send window of the GP
10057 	 * estimate. So to prevent that and keep it working with
10058 	 * a tiny bit more limited merging, we only allow like
10059 	 * types to be merged. I.e. if two sends are in the GP window
10060 	 * then its ok to merge them together. If two sends are not
10061 	 * in the GP window its ok to merge them together too. Though
10062 	 * one send in and one send out cannot be merged. We combine
10063 	 * this with never allowing the shrinking of the GP window when
10064 	 * we are in recovery so that we can properly calculate the
10065 	 * sending times.
10066 	 *
10067 	 * This all of course seems complicated, because it is.. :)
10068 	 *
10069 	 * The cum-ack is being advanced upon the sendmap.
10070 	 * If we are not doing a GP estimate don't
10071 	 * proceed.
10072 	 */
10073 	uint64_t ts;
10074 
10075 	if ((tp->t_flags & TF_GPUTINPROG) == 0)
10076 		return;
10077 	/*
10078 	 * If this sendmap entry is going
10079 	 * beyond the measurement window we had picked,
10080 	 * expand the measurement window by that much.
10081 	 */
10082 	if (SEQ_GT(rsm->r_end, tp->gput_ack)) {
10083 		tp->gput_ack = rsm->r_end;
10084 	}
10085 	/*
10086 	 * If we have not setup a ack, then we
10087 	 * have no idea if the newly acked pieces
10088 	 * will be "in our seq measurement range". If
10089 	 * it is when we clear the app_limited_needs_set
10090 	 * flag the timestamp will be updated.
10091 	 */
10092 	if (rack->app_limited_needs_set)
10093 		return;
10094 	/*
10095 	 * Finally, we grab out the latest timestamp
10096 	 * that this packet was sent and then see
10097 	 * if:
10098 	 *  a) The packet touches are newly defined GP range.
10099 	 *  b) The time is greater than (newer) than the
10100 	 *     one we currently have. If so we update
10101 	 *     our sending end time window.
10102 	 *
10103 	 * Note we *do not* do this at send time. The reason
10104 	 * is that if you do you *may* pick up a newer timestamp
10105 	 * for a range you are not going to measure. We project
10106 	 * out how far and then sometimes modify that to be
10107 	 * smaller. If that occurs then you will have a send
10108 	 * that does not belong to the range included.
10109 	 */
10110 	if ((ts = rsm->r_tim_lastsent[(rsm->r_rtr_cnt-1)]) <=
10111 	    rack->r_ctl.rc_gp_cumack_ts)
10112 		return;
10113 	if (rack_in_gp_window(tp, rsm)) {
10114 		rack->r_ctl.rc_gp_cumack_ts = ts;
10115 		rack_log_gpset(rack, tp->gput_ack, (uint32_t)ts, rsm->r_end,
10116 			       __LINE__, from, rsm);
10117 	}
10118 }
10119 
10120 static void
10121 rack_process_to_cumack(struct tcpcb *tp, struct tcp_rack *rack, register uint32_t th_ack, uint32_t cts, struct tcpopt *to, uint64_t acktime)
10122 {
10123 	struct rack_sendmap *rsm;
10124 	/*
10125 	 * The ACK point is advancing to th_ack, we must drop off
10126 	 * the packets in the rack log and calculate any eligble
10127 	 * RTT's.
10128 	 */
10129 
10130 	if (sack_filter_blks_used(&rack->r_ctl.rack_sf)) {
10131 		/*
10132 		 * If we have some sack blocks in the filter
10133 		 * lets prune them out by calling sfb with no blocks.
10134 		 */
10135 		sack_filter_blks(tp, &rack->r_ctl.rack_sf, NULL, 0, th_ack);
10136 	}
10137 	if (SEQ_GT(th_ack, tp->snd_una)) {
10138 		/* Clear any app ack remembered settings */
10139 		rack->r_ctl.cleared_app_ack = 0;
10140 	}
10141 	rack->r_wanted_output = 1;
10142 	if (SEQ_GT(th_ack, tp->snd_una))
10143 		rack->r_ctl.last_cumack_advance = acktime;
10144 
10145 	/* Tend any TLP that has been marked for 1/2 the seq space (its old)  */
10146 	if ((rack->rc_last_tlp_acked_set == 1)&&
10147 	    (rack->rc_last_tlp_past_cumack == 1) &&
10148 	    (SEQ_GT(rack->r_ctl.last_tlp_acked_start, th_ack))) {
10149 		/*
10150 		 * We have reached the point where our last rack
10151 		 * tlp retransmit sequence is ahead of the cum-ack.
10152 		 * This can only happen when the cum-ack moves all
10153 		 * the way around (its been a full 2^^31+1 bytes
10154 		 * or more since we sent a retransmitted TLP). Lets
10155 		 * turn off the valid flag since its not really valid.
10156 		 *
10157 		 * Note since sack's also turn on this event we have
10158 		 * a complication, we have to wait to age it out until
10159 		 * the cum-ack is by the TLP before checking which is
10160 		 * what the next else clause does.
10161 		 */
10162 		rack_log_dsack_event(rack, 9, __LINE__,
10163 				     rack->r_ctl.last_tlp_acked_start,
10164 				     rack->r_ctl.last_tlp_acked_end);
10165 		rack->rc_last_tlp_acked_set = 0;
10166 		rack->rc_last_tlp_past_cumack = 0;
10167 	} else if ((rack->rc_last_tlp_acked_set == 1) &&
10168 		   (rack->rc_last_tlp_past_cumack == 0) &&
10169 		   (SEQ_GEQ(th_ack, rack->r_ctl.last_tlp_acked_end))) {
10170 		/*
10171 		 * It is safe to start aging TLP's out.
10172 		 */
10173 		rack->rc_last_tlp_past_cumack = 1;
10174 	}
10175 	/* We do the same for the tlp send seq as well */
10176 	if ((rack->rc_last_sent_tlp_seq_valid == 1) &&
10177 	    (rack->rc_last_sent_tlp_past_cumack == 1) &&
10178 	    (SEQ_GT(rack->r_ctl.last_sent_tlp_seq,  th_ack))) {
10179 		rack_log_dsack_event(rack, 9, __LINE__,
10180 				     rack->r_ctl.last_sent_tlp_seq,
10181 				     (rack->r_ctl.last_sent_tlp_seq +
10182 				      rack->r_ctl.last_sent_tlp_len));
10183 		rack->rc_last_sent_tlp_seq_valid = 0;
10184 		rack->rc_last_sent_tlp_past_cumack = 0;
10185 	} else if ((rack->rc_last_sent_tlp_seq_valid == 1) &&
10186 		   (rack->rc_last_sent_tlp_past_cumack == 0) &&
10187 		   (SEQ_GEQ(th_ack, rack->r_ctl.last_sent_tlp_seq))) {
10188 		/*
10189 		 * It is safe to start aging TLP's send.
10190 		 */
10191 		rack->rc_last_sent_tlp_past_cumack = 1;
10192 	}
10193 more:
10194 	rsm = tqhash_min(rack->r_ctl.tqh);
10195 	if (rsm == NULL) {
10196 		if ((th_ack - 1) == tp->iss) {
10197 			/*
10198 			 * For the SYN incoming case we will not
10199 			 * have called tcp_output for the sending of
10200 			 * the SYN, so there will be no map. All
10201 			 * other cases should probably be a panic.
10202 			 */
10203 			return;
10204 		}
10205 		if (tp->t_flags & TF_SENTFIN) {
10206 			/* if we sent a FIN we often will not have map */
10207 			return;
10208 		}
10209 #ifdef INVARIANTS
10210 		panic("No rack map tp:%p for state:%d ack:%u rack:%p snd_una:%u snd_max:%u\n",
10211 		      tp,
10212 		      tp->t_state, th_ack, rack,
10213 		      tp->snd_una, tp->snd_max);
10214 #endif
10215 		return;
10216 	}
10217 	if (SEQ_LT(th_ack, rsm->r_start)) {
10218 		/* Huh map is missing this */
10219 #ifdef INVARIANTS
10220 		printf("Rack map starts at r_start:%u for th_ack:%u huh? ts:%d rs:%d\n",
10221 		       rsm->r_start,
10222 		       th_ack, tp->t_state, rack->r_state);
10223 #endif
10224 		return;
10225 	}
10226 	rack_update_rtt(tp, rack, rsm, to, cts, CUM_ACKED, th_ack);
10227 
10228 	/* Now was it a retransmitted TLP? */
10229 	if ((rsm->r_flags & RACK_TLP) &&
10230 	    (rsm->r_rtr_cnt > 1)) {
10231 		/*
10232 		 * Yes, this rsm was a TLP and retransmitted, remember that
10233 		 * since if a DSACK comes back on this we don't want
10234 		 * to think of it as a reordered segment. This may
10235 		 * get updated again with possibly even other TLPs
10236 		 * in flight, but thats ok. Only when we don't send
10237 		 * a retransmitted TLP for 1/2 the sequences space
10238 		 * will it get turned off (above).
10239 		 */
10240 		if (rack->rc_last_tlp_acked_set &&
10241 		    (is_rsm_inside_declared_tlp_block(rack, rsm))) {
10242 			/*
10243 			 * We already turned this on since the end matches,
10244 			 * the previous one was a partially ack now we
10245 			 * are getting another one (maybe all of it).
10246 			 */
10247 			rack_log_dsack_event(rack, 10, __LINE__, rsm->r_start, rsm->r_end);
10248 			/*
10249 			 * Lets make sure we have all of it though.
10250 			 */
10251 			if (SEQ_LT(rsm->r_start, rack->r_ctl.last_tlp_acked_start)) {
10252 				rack->r_ctl.last_tlp_acked_start = rsm->r_start;
10253 				rack_log_dsack_event(rack, 11, __LINE__, rack->r_ctl.last_tlp_acked_start,
10254 						     rack->r_ctl.last_tlp_acked_end);
10255 			}
10256 			if (SEQ_GT(rsm->r_end, rack->r_ctl.last_tlp_acked_end)) {
10257 				rack->r_ctl.last_tlp_acked_end = rsm->r_end;
10258 				rack_log_dsack_event(rack, 11, __LINE__, rack->r_ctl.last_tlp_acked_start,
10259 						     rack->r_ctl.last_tlp_acked_end);
10260 			}
10261 		} else {
10262 			rack->rc_last_tlp_past_cumack = 1;
10263 			rack->r_ctl.last_tlp_acked_start = rsm->r_start;
10264 			rack->r_ctl.last_tlp_acked_end = rsm->r_end;
10265 			rack->rc_last_tlp_acked_set = 1;
10266 			rack_log_dsack_event(rack, 8, __LINE__, rsm->r_start, rsm->r_end);
10267 		}
10268 	}
10269 	/* Now do we consume the whole thing? */
10270 	rack->r_ctl.last_tmit_time_acked = rsm->r_tim_lastsent[(rsm->r_rtr_cnt - 1)];
10271 	if (SEQ_GEQ(th_ack, rsm->r_end)) {
10272 		/* Its all consumed. */
10273 		uint32_t left;
10274 		uint8_t newly_acked;
10275 
10276 		if (rsm->r_flags & RACK_WAS_LOST) {
10277 			/*
10278 			 * This can happen when we marked it as lost
10279 			 * and yet before retransmitting we get an ack
10280 			 * which can happen due to reordering.
10281 			 */
10282 			rack_mark_nolonger_lost(rack, rsm);
10283 		}
10284 		rack_log_map_chg(tp, rack, NULL, rsm, NULL, MAP_FREE, rsm->r_end, __LINE__);
10285 		rack->r_ctl.rc_holes_rxt -= rsm->r_rtr_bytes;
10286 		rsm->r_rtr_bytes = 0;
10287 		/*
10288 		 * Record the time of highest cumack sent if its in our measurement
10289 		 * window and possibly bump out the end.
10290 		 */
10291 		rack_rsm_sender_update(rack, tp, rsm, 4);
10292 		tqhash_remove(rack->r_ctl.tqh, rsm, REMOVE_TYPE_CUMACK);
10293 		if (rsm->r_in_tmap) {
10294 			TAILQ_REMOVE(&rack->r_ctl.rc_tmap, rsm, r_tnext);
10295 			rsm->r_in_tmap = 0;
10296 		}
10297 		newly_acked = 1;
10298 		if (rsm->r_flags & RACK_ACKED) {
10299 			/*
10300 			 * It was acked on the scoreboard -- remove
10301 			 * it from total
10302 			 */
10303 			rack->r_ctl.rc_sacked -= (rsm->r_end - rsm->r_start);
10304 			newly_acked = 0;
10305 		} else if (rsm->r_flags & RACK_SACK_PASSED) {
10306 			/*
10307 			 * There are segments ACKED on the
10308 			 * scoreboard further up. We are seeing
10309 			 * reordering.
10310 			 */
10311 			rsm->r_flags &= ~RACK_SACK_PASSED;
10312 			rsm->r_ack_arrival = rack_to_usec_ts(&rack->r_ctl.act_rcv_time);
10313 			rsm->r_flags |= RACK_ACKED;
10314 			rack->r_ctl.rc_reorder_ts = cts;
10315 			if (rack->r_ctl.rc_reorder_ts == 0)
10316 				rack->r_ctl.rc_reorder_ts = 1;
10317 			if (rack->r_ent_rec_ns) {
10318 				/*
10319 				 * We have sent no more, and we saw an sack
10320 				 * then ack arrive.
10321 				 */
10322 				rack->r_might_revert = 1;
10323 			}
10324 			rack_update_pcm_ack(rack, 1, rsm->r_start, rsm->r_end);
10325 		} else {
10326 			(void)rack_check_reorder_ack(tp, rack, rsm, rsm->r_end, cts, 1, __LINE__);
10327 			rack_update_pcm_ack(rack, 1, rsm->r_start, rsm->r_end);
10328 		}
10329 		if ((rsm->r_flags & RACK_TO_REXT) &&
10330 		    (tp->t_flags & TF_RCVD_TSTMP) &&
10331 		    (to->to_flags & TOF_TS) &&
10332 		    (to->to_tsecr != 0) &&
10333 		    (tp->t_flags & TF_PREVVALID)) {
10334 			/*
10335 			 * We can use the timestamp to see
10336 			 * if this retransmission was from the
10337 			 * first transmit. If so we made a mistake.
10338 			 */
10339 			tp->t_flags &= ~TF_PREVVALID;
10340 			if (to->to_tsecr == rack_ts_to_msec(rsm->r_tim_lastsent[0])) {
10341 				/* The first transmit is what this ack is for */
10342 				rack_cong_signal(tp, CC_RTO_ERR, th_ack, __LINE__);
10343 			}
10344 		}
10345 		left = th_ack - rsm->r_end;
10346 		if (rack->app_limited_needs_set && newly_acked)
10347 			rack_need_set_test(tp, rack, rsm, th_ack, __LINE__, RACK_USE_END_OR_THACK);
10348 		/* Free back to zone */
10349 		rack_free(rack, rsm);
10350 		if (left) {
10351 			goto more;
10352 		}
10353 		/* Check for reneging */
10354 		rsm = tqhash_min(rack->r_ctl.tqh);
10355 		if (rsm && (rsm->r_flags & RACK_ACKED) && (th_ack == rsm->r_start)) {
10356 			/*
10357 			 * The peer has moved snd_una up to
10358 			 * the edge of this send, i.e. one
10359 			 * that it had previously acked. The only
10360 			 * way that can be true if the peer threw
10361 			 * away data (space issues) that it had
10362 			 * previously sacked (else it would have
10363 			 * given us snd_una up to (rsm->r_end).
10364 			 * We need to undo the acked markings here.
10365 			 *
10366 			 * Note we have to look to make sure th_ack is
10367 			 * our rsm->r_start in case we get an old ack
10368 			 * where th_ack is behind snd_una.
10369 			 */
10370 			rack_peer_reneges(rack, rsm, th_ack);
10371 		}
10372 		return;
10373 	}
10374 	if (rsm->r_flags & RACK_ACKED) {
10375 		/*
10376 		 * It was acked on the scoreboard -- remove it from
10377 		 * total for the part being cum-acked.
10378 		 */
10379 		rack->r_ctl.rc_sacked -= (th_ack - rsm->r_start);
10380 	} else {
10381 		rack_update_pcm_ack(rack, 1, rsm->r_start, th_ack);
10382 	}
10383 	/* And what about the lost flag? */
10384 	if (rsm->r_flags & RACK_WAS_LOST) {
10385 		/*
10386 		 * This can happen when we marked it as lost
10387 		 * and yet before retransmitting we get an ack
10388 		 * which can happen due to reordering. In this
10389 		 * case its only a partial ack of the send.
10390 		 */
10391 		rack_mark_nolonger_lost(rack, rsm);
10392 	}
10393 	/*
10394 	 * Clear the dup ack count for
10395 	 * the piece that remains.
10396 	 */
10397 	rsm->r_dupack = 0;
10398 	rack_log_retran_reason(rack, rsm, __LINE__, 0, 2);
10399 	if (rsm->r_rtr_bytes) {
10400 		/*
10401 		 * It was retransmitted adjust the
10402 		 * sack holes for what was acked.
10403 		 */
10404 		int ack_am;
10405 
10406 		ack_am = (th_ack - rsm->r_start);
10407 		if (ack_am >= rsm->r_rtr_bytes) {
10408 			rack->r_ctl.rc_holes_rxt -= ack_am;
10409 			rsm->r_rtr_bytes -= ack_am;
10410 		}
10411 	}
10412 	/*
10413 	 * Update where the piece starts and record
10414 	 * the time of send of highest cumack sent if
10415 	 * its in our GP range.
10416 	 */
10417 	rack_log_map_chg(tp, rack, NULL, rsm, NULL, MAP_TRIM_HEAD, th_ack, __LINE__);
10418 	/* Now we need to move our offset forward too */
10419 	if (rsm->m &&
10420 	    ((rsm->orig_m_len != rsm->m->m_len) ||
10421 	     (M_TRAILINGROOM(rsm->m) != rsm->orig_t_space))) {
10422 		/* Fix up the orig_m_len and possibly the mbuf offset */
10423 		rack_adjust_orig_mlen(rsm);
10424 	}
10425 	rsm->soff += (th_ack - rsm->r_start);
10426 	rack_rsm_sender_update(rack, tp, rsm, 5);
10427 
10428 	/*
10429 	 * Handle the special case where we retransmitted part of a segment we
10430 	 * in this case pass in th_ack which is shorter than r_end.
10431 	 */
10432 	if (rsm->r_flags & RACK_WAS_SACKPASS) {
10433 		rack_check_reorder_ack(tp, rack, rsm, th_ack, cts, 1, __LINE__);
10434 	}
10435 	/* The trim will move th_ack into r_start for us */
10436 	tqhash_trim(rack->r_ctl.tqh, th_ack);
10437 	/* Now do we need to move the mbuf fwd too? */
10438 	{
10439 		struct mbuf *m;
10440 		uint32_t soff;
10441 
10442 		m = rsm->m;
10443 		soff = rsm->soff;
10444 		if (m) {
10445 			while (soff >= m->m_len) {
10446 				soff -= m->m_len;
10447 				KASSERT((m->m_next != NULL),
10448 					(" rsm:%p  off:%u soff:%u m:%p",
10449 					 rsm, rsm->soff, soff, m));
10450 				m = m->m_next;
10451 				if (m == NULL) {
10452 					/*
10453 					 * This is a fall-back that prevents a panic. In reality
10454 					 * we should be able to walk the mbuf's and find our place.
10455 					 * At this point snd_una has not been updated with the sbcut() yet
10456 					 * but tqhash_trim did update rsm->r_start so the offset calcuation
10457 					 * should work fine. This is undesirable since we will take cache
10458 					 * hits to access the socket buffer. And even more puzzling is that
10459 					 * it happens occasionally. It should not :(
10460 					 */
10461 					m = sbsndmbuf(&rack->rc_inp->inp_socket->so_snd,
10462 						      (rsm->r_start - tp->snd_una),
10463 						      &soff);
10464 					break;
10465 				}
10466 			}
10467 			/*
10468 			 * Now save in our updated values.
10469 			 */
10470 			rsm->m = m;
10471 			rsm->soff = soff;
10472 			rsm->orig_m_len = rsm->m->m_len;
10473 			rsm->orig_t_space = M_TRAILINGROOM(rsm->m);
10474 		}
10475 	}
10476 	if (rack->app_limited_needs_set &&
10477 	    SEQ_GEQ(th_ack, tp->gput_seq))
10478 		rack_need_set_test(tp, rack, rsm, tp->snd_una, __LINE__, RACK_USE_BEG);
10479 }
10480 
10481 static void
10482 rack_handle_might_revert(struct tcpcb *tp, struct tcp_rack *rack)
10483 {
10484 	struct rack_sendmap *rsm;
10485 	int sack_pass_fnd = 0;
10486 
10487 	if (rack->r_might_revert) {
10488 		/*
10489 		 * Ok we have reordering, have not sent anything, we
10490 		 * might want to revert the congestion state if nothing
10491 		 * further has SACK_PASSED on it. Lets check.
10492 		 *
10493 		 * We also get here when we have DSACKs come in for
10494 		 * all the data that we FR'd. Note that a rxt or tlp
10495 		 * timer clears this from happening.
10496 		 */
10497 
10498 		TAILQ_FOREACH(rsm, &rack->r_ctl.rc_tmap, r_tnext) {
10499 			if (rsm->r_flags & RACK_SACK_PASSED) {
10500 				sack_pass_fnd = 1;
10501 				break;
10502 			}
10503 		}
10504 		if (sack_pass_fnd == 0) {
10505 			/*
10506 			 * We went into recovery
10507 			 * incorrectly due to reordering!
10508 			 */
10509 			int orig_cwnd;
10510 
10511 			rack->r_ent_rec_ns = 0;
10512 			orig_cwnd = tp->snd_cwnd;
10513 			tp->snd_ssthresh = rack->r_ctl.rc_ssthresh_at_erec;
10514 			tp->snd_recover = tp->snd_una;
10515 			rack_log_to_prr(rack, 14, orig_cwnd, __LINE__);
10516 			if (IN_RECOVERY(tp->t_flags)) {
10517 				rack_exit_recovery(tp, rack, 3);
10518 				if ((rack->rto_from_rec == 1) && (rack_ssthresh_rest_rto_rec != 0) ){
10519 					/*
10520 					 * We were in recovery, had an RTO
10521 					 * and then re-entered recovery (more sack's arrived)
10522 					 * and we have properly recorded the old ssthresh from
10523 					 * the first recovery. We want to be able to slow-start
10524 					 * back to this level. The ssthresh from the timeout
10525 					 * and then back into recovery will end up most likely
10526 					 * to be min(cwnd=1mss, 2mss). Which makes it basically
10527 					 * so we get no slow-start after our RTO.
10528 					 */
10529 					rack->rto_from_rec = 0;
10530 					if (rack->r_ctl.rto_ssthresh > tp->snd_ssthresh)
10531 						tp->snd_ssthresh = rack->r_ctl.rto_ssthresh;
10532 				}
10533 			}
10534 		}
10535 		rack->r_might_revert = 0;
10536 	}
10537 }
10538 
10539 
10540 static int
10541 rack_note_dsack(struct tcp_rack *rack, tcp_seq start, tcp_seq end)
10542 {
10543 
10544 	uint32_t am, l_end;
10545 	int was_tlp = 0;
10546 
10547 	if (SEQ_GT(end, start))
10548 		am = end - start;
10549 	else
10550 		am = 0;
10551 	if ((rack->rc_last_tlp_acked_set ) &&
10552 	    (SEQ_GEQ(start, rack->r_ctl.last_tlp_acked_start)) &&
10553 	    (SEQ_LEQ(end, rack->r_ctl.last_tlp_acked_end))) {
10554 		/*
10555 		 * The DSACK is because of a TLP which we don't
10556 		 * do anything with the reordering window over since
10557 		 * it was not reordering that caused the DSACK but
10558 		 * our previous retransmit TLP.
10559 		 */
10560 		rack_log_dsack_event(rack, 7, __LINE__, start, end);
10561 		was_tlp = 1;
10562 		goto skip_dsack_round;
10563 	}
10564 	if (rack->rc_last_sent_tlp_seq_valid) {
10565 		l_end = rack->r_ctl.last_sent_tlp_seq + rack->r_ctl.last_sent_tlp_len;
10566 		if (SEQ_GEQ(start, rack->r_ctl.last_sent_tlp_seq) &&
10567 		    (SEQ_LEQ(end, l_end))) {
10568 			/*
10569 			 * This dsack is from the last sent TLP, ignore it
10570 			 * for reordering purposes.
10571 			 */
10572 			rack_log_dsack_event(rack, 7, __LINE__, start, end);
10573 			was_tlp = 1;
10574 			goto skip_dsack_round;
10575 		}
10576 	}
10577 	if (rack->rc_dsack_round_seen == 0) {
10578 		rack->rc_dsack_round_seen = 1;
10579 		rack->r_ctl.dsack_round_end = rack->rc_tp->snd_max;
10580 		rack->r_ctl.num_dsack++;
10581 		rack->r_ctl.dsack_persist = 16;	/* 16 is from the standard */
10582 		rack_log_dsack_event(rack, 2, __LINE__, 0, 0);
10583 	}
10584 skip_dsack_round:
10585 	/*
10586 	 * We keep track of how many DSACK blocks we get
10587 	 * after a recovery incident.
10588 	 */
10589 	rack->r_ctl.dsack_byte_cnt += am;
10590 	if (!IN_FASTRECOVERY(rack->rc_tp->t_flags) &&
10591 	    rack->r_ctl.retran_during_recovery &&
10592 	    (rack->r_ctl.dsack_byte_cnt >= rack->r_ctl.retran_during_recovery)) {
10593 		/*
10594 		 * False recovery most likely culprit is reordering. If
10595 		 * nothing else is missing we need to revert.
10596 		 */
10597 		rack->r_might_revert = 1;
10598 		rack_handle_might_revert(rack->rc_tp, rack);
10599 		rack->r_might_revert = 0;
10600 		rack->r_ctl.retran_during_recovery = 0;
10601 		rack->r_ctl.dsack_byte_cnt = 0;
10602 	}
10603 	return (was_tlp);
10604 }
10605 
10606 static uint32_t
10607 do_rack_compute_pipe(struct tcpcb *tp, struct tcp_rack *rack, uint32_t snd_una)
10608 {
10609 	return (((tp->snd_max - snd_una) -
10610 		 (rack->r_ctl.rc_sacked + rack->r_ctl.rc_considered_lost)) + rack->r_ctl.rc_holes_rxt);
10611 }
10612 
10613 static int32_t
10614 rack_compute_pipe(struct tcpcb *tp)
10615 {
10616 	return ((int32_t)do_rack_compute_pipe(tp,
10617 					      (struct tcp_rack *)tp->t_fb_ptr,
10618 					      tp->snd_una));
10619 }
10620 
10621 static void
10622 rack_update_prr(struct tcpcb *tp, struct tcp_rack *rack, uint32_t changed, tcp_seq th_ack)
10623 {
10624 	/* Deal with changed and PRR here (in recovery only) */
10625 	uint32_t pipe, snd_una;
10626 
10627 	rack->r_ctl.rc_prr_delivered += changed;
10628 
10629 	if (sbavail(&rack->rc_inp->inp_socket->so_snd) <= (tp->snd_max - tp->snd_una)) {
10630 		/*
10631 		 * It is all outstanding, we are application limited
10632 		 * and thus we don't need more room to send anything.
10633 		 * Note we use tp->snd_una here and not th_ack because
10634 		 * the data as yet not been cut from the sb.
10635 		 */
10636 		rack->r_ctl.rc_prr_sndcnt = 0;
10637 		return;
10638 	}
10639 	/* Compute prr_sndcnt */
10640 	if (SEQ_GT(tp->snd_una, th_ack)) {
10641 		snd_una = tp->snd_una;
10642 	} else {
10643 		snd_una = th_ack;
10644 	}
10645 	pipe = do_rack_compute_pipe(tp, rack, snd_una);
10646 	if (pipe > tp->snd_ssthresh) {
10647 		long sndcnt;
10648 
10649 		sndcnt = rack->r_ctl.rc_prr_delivered * tp->snd_ssthresh;
10650 		if (rack->r_ctl.rc_prr_recovery_fs > 0)
10651 			sndcnt /= (long)rack->r_ctl.rc_prr_recovery_fs;
10652 		else {
10653 			rack->r_ctl.rc_prr_sndcnt = 0;
10654 			rack_log_to_prr(rack, 9, 0, __LINE__);
10655 			sndcnt = 0;
10656 		}
10657 		sndcnt++;
10658 		if (sndcnt > (long)rack->r_ctl.rc_prr_out)
10659 			sndcnt -= rack->r_ctl.rc_prr_out;
10660 		else
10661 			sndcnt = 0;
10662 		rack->r_ctl.rc_prr_sndcnt = sndcnt;
10663 		rack_log_to_prr(rack, 10, 0, __LINE__);
10664 	} else {
10665 		uint32_t limit;
10666 
10667 		if (rack->r_ctl.rc_prr_delivered > rack->r_ctl.rc_prr_out)
10668 			limit = (rack->r_ctl.rc_prr_delivered - rack->r_ctl.rc_prr_out);
10669 		else
10670 			limit = 0;
10671 		if (changed > limit)
10672 			limit = changed;
10673 		limit += ctf_fixed_maxseg(tp);
10674 		if (tp->snd_ssthresh > pipe) {
10675 			rack->r_ctl.rc_prr_sndcnt = min((tp->snd_ssthresh - pipe), limit);
10676 			rack_log_to_prr(rack, 11, 0, __LINE__);
10677 		} else {
10678 			rack->r_ctl.rc_prr_sndcnt = min(0, limit);
10679 			rack_log_to_prr(rack, 12, 0, __LINE__);
10680 		}
10681 	}
10682 }
10683 
10684 static void
10685 rack_log_ack(struct tcpcb *tp, struct tcpopt *to, struct tcphdr *th, int entered_recovery, int dup_ack_struck,
10686 	     int *dsack_seen, int *sacks_seen)
10687 {
10688 	uint32_t changed;
10689 	struct tcp_rack *rack;
10690 	struct rack_sendmap *rsm;
10691 	struct sackblk sack, sack_blocks[TCP_MAX_SACK + 1];
10692 	register uint32_t th_ack;
10693 	int32_t i, j, k, num_sack_blks = 0;
10694 	uint32_t cts, acked, ack_point;
10695 	int loop_start = 0;
10696 	uint32_t tsused;
10697 	uint32_t segsiz;
10698 
10699 
10700 	INP_WLOCK_ASSERT(tptoinpcb(tp));
10701 	if (tcp_get_flags(th) & TH_RST) {
10702 		/* We don't log resets */
10703 		return;
10704 	}
10705 	rack = (struct tcp_rack *)tp->t_fb_ptr;
10706 	cts = tcp_get_usecs(NULL);
10707 	rsm = tqhash_min(rack->r_ctl.tqh);
10708 	changed = 0;
10709 	th_ack = th->th_ack;
10710 	segsiz = ctf_fixed_maxseg(rack->rc_tp);
10711 	if (SEQ_GT(th_ack, tp->snd_una)) {
10712 		rack_log_progress_event(rack, tp, ticks, PROGRESS_UPDATE, __LINE__);
10713 		tp->t_acktime = ticks;
10714 	}
10715 	if (rsm && SEQ_GT(th_ack, rsm->r_start))
10716 		changed = th_ack - rsm->r_start;
10717 	if (changed) {
10718 		rack_process_to_cumack(tp, rack, th_ack, cts, to,
10719 				       tcp_tv_to_lusec(&rack->r_ctl.act_rcv_time));
10720 	}
10721 	if ((to->to_flags & TOF_SACK) == 0) {
10722 		/* We are done nothing left and no sack. */
10723 		rack_handle_might_revert(tp, rack);
10724 		/*
10725 		 * For cases where we struck a dup-ack
10726 		 * with no SACK, add to the changes so
10727 		 * PRR will work right.
10728 		 */
10729 		if (dup_ack_struck && (changed == 0)) {
10730 			changed += ctf_fixed_maxseg(rack->rc_tp);
10731 		}
10732 		goto out;
10733 	}
10734 	/* Sack block processing */
10735 	if (SEQ_GT(th_ack, tp->snd_una))
10736 		ack_point = th_ack;
10737 	else
10738 		ack_point = tp->snd_una;
10739 	for (i = 0; i < to->to_nsacks; i++) {
10740 		bcopy((to->to_sacks + i * TCPOLEN_SACK),
10741 		      &sack, sizeof(sack));
10742 		sack.start = ntohl(sack.start);
10743 		sack.end = ntohl(sack.end);
10744 		if (SEQ_GT(sack.end, sack.start) &&
10745 		    SEQ_GT(sack.start, ack_point) &&
10746 		    SEQ_LT(sack.start, tp->snd_max) &&
10747 		    SEQ_GT(sack.end, ack_point) &&
10748 		    SEQ_LEQ(sack.end, tp->snd_max)) {
10749 			sack_blocks[num_sack_blks] = sack;
10750 			num_sack_blks++;
10751 		} else if (SEQ_LEQ(sack.start, th_ack) &&
10752 			   SEQ_LEQ(sack.end, th_ack)) {
10753 			int was_tlp;
10754 
10755 			if (dsack_seen != NULL)
10756 				*dsack_seen = 1;
10757 			was_tlp = rack_note_dsack(rack, sack.start, sack.end);
10758 			/*
10759 			 * Its a D-SACK block.
10760 			 */
10761 			tcp_record_dsack(tp, sack.start, sack.end, was_tlp);
10762 		}
10763 	}
10764 	if (rack->rc_dsack_round_seen) {
10765 		/* Is the dsack roound over? */
10766 		if (SEQ_GEQ(th_ack, rack->r_ctl.dsack_round_end)) {
10767 			/* Yes it is */
10768 			rack->rc_dsack_round_seen = 0;
10769 			rack_log_dsack_event(rack, 3, __LINE__, 0, 0);
10770 		}
10771 	}
10772 	/*
10773 	 * Sort the SACK blocks so we can update the rack scoreboard with
10774 	 * just one pass.
10775 	 */
10776 	num_sack_blks = sack_filter_blks(tp, &rack->r_ctl.rack_sf, sack_blocks,
10777 					 num_sack_blks, th->th_ack);
10778 	ctf_log_sack_filter(rack->rc_tp, num_sack_blks, sack_blocks);
10779 	if (sacks_seen != NULL)
10780 		*sacks_seen = num_sack_blks;
10781 	if (num_sack_blks == 0) {
10782 		/* Nothing to sack */
10783 		goto out;
10784 	}
10785 	/* Its a sack of some sort */
10786 	if (num_sack_blks < 2) {
10787 		/* Only one, we don't need to sort */
10788 		goto do_sack_work;
10789 	}
10790 	/* Sort the sacks */
10791 	for (i = 0; i < num_sack_blks; i++) {
10792 		for (j = i + 1; j < num_sack_blks; j++) {
10793 			if (SEQ_GT(sack_blocks[i].end, sack_blocks[j].end)) {
10794 				sack = sack_blocks[i];
10795 				sack_blocks[i] = sack_blocks[j];
10796 				sack_blocks[j] = sack;
10797 			}
10798 		}
10799 	}
10800 	/*
10801 	 * Now are any of the sack block ends the same (yes some
10802 	 * implementations send these)?
10803 	 */
10804 again:
10805 	if (num_sack_blks == 0)
10806 		goto out;
10807 	if (num_sack_blks > 1) {
10808 		for (i = 0; i < num_sack_blks; i++) {
10809 			for (j = i + 1; j < num_sack_blks; j++) {
10810 				if (sack_blocks[i].end == sack_blocks[j].end) {
10811 					/*
10812 					 * Ok these two have the same end we
10813 					 * want the smallest end and then
10814 					 * throw away the larger and start
10815 					 * again.
10816 					 */
10817 					if (SEQ_LT(sack_blocks[j].start, sack_blocks[i].start)) {
10818 						/*
10819 						 * The second block covers
10820 						 * more area use that
10821 						 */
10822 						sack_blocks[i].start = sack_blocks[j].start;
10823 					}
10824 					/*
10825 					 * Now collapse out the dup-sack and
10826 					 * lower the count
10827 					 */
10828 					for (k = (j + 1); k < num_sack_blks; k++) {
10829 						sack_blocks[j].start = sack_blocks[k].start;
10830 						sack_blocks[j].end = sack_blocks[k].end;
10831 						j++;
10832 					}
10833 					num_sack_blks--;
10834 					goto again;
10835 				}
10836 			}
10837 		}
10838 	}
10839 do_sack_work:
10840 	/*
10841 	 * First lets look to see if
10842 	 * we have retransmitted and
10843 	 * can use the transmit next?
10844 	 */
10845 	rsm = TAILQ_FIRST(&rack->r_ctl.rc_tmap);
10846 	if (rsm &&
10847 	    SEQ_GT(sack_blocks[0].end, rsm->r_start) &&
10848 	    SEQ_LT(sack_blocks[0].start, rsm->r_end)) {
10849 		/*
10850 		 * We probably did the FR and the next
10851 		 * SACK in continues as we would expect.
10852 		 */
10853 		acked = rack_proc_sack_blk(tp, rack, &sack_blocks[0], to, &rsm, cts, segsiz);
10854 		if (acked) {
10855 			rack->r_wanted_output = 1;
10856 			changed += acked;
10857 		}
10858 		if (num_sack_blks == 1) {
10859 			goto out;
10860 		} else {
10861 			/*
10862 			 * Start the loop through the
10863 			 * rest of blocks, past the first block.
10864 			 */
10865 			loop_start = 1;
10866 		}
10867 	}
10868 	rsm = rack->r_ctl.rc_sacklast;
10869 	for (i = loop_start; i < num_sack_blks; i++) {
10870 		acked = rack_proc_sack_blk(tp, rack, &sack_blocks[i], to, &rsm, cts,  segsiz);
10871 		if (acked) {
10872 			rack->r_wanted_output = 1;
10873 			changed += acked;
10874 		}
10875 	}
10876 out:
10877 	if (changed) {
10878 		/* Something changed cancel the rack timer */
10879 		rack_timer_cancel(tp, rack, rack->r_ctl.rc_rcvtime, __LINE__);
10880 	}
10881 	tsused = tcp_get_usecs(NULL);
10882 	rsm = tcp_rack_output(tp, rack, tsused);
10883 	if ((!IN_FASTRECOVERY(tp->t_flags)) &&
10884 	    rsm &&
10885 	    ((rsm->r_flags & RACK_MUST_RXT) == 0)) {
10886 		/* Enter recovery */
10887 		entered_recovery = 1;
10888 		rack_cong_signal(tp, CC_NDUPACK, th_ack, __LINE__);
10889 		/*
10890 		 * When we enter recovery we need to assure we send
10891 		 * one packet.
10892 		 */
10893 		if (rack->rack_no_prr == 0) {
10894 			rack->r_ctl.rc_prr_sndcnt = ctf_fixed_maxseg(tp);
10895 			rack_log_to_prr(rack, 8, 0, __LINE__);
10896 		}
10897 		rack->r_timer_override = 1;
10898 		rack->r_early = 0;
10899 		rack->r_ctl.rc_agg_early = 0;
10900 	} else if (IN_FASTRECOVERY(tp->t_flags) &&
10901 		   rsm &&
10902 		   (rack->r_rr_config == 3)) {
10903 		/*
10904 		 * Assure we can output and we get no
10905 		 * remembered pace time except the retransmit.
10906 		 */
10907 		rack->r_timer_override = 1;
10908 		rack->r_ctl.rc_hpts_flags &= ~PACE_PKT_OUTPUT;
10909 		rack->r_ctl.rc_resend = rsm;
10910 	}
10911 	if (IN_FASTRECOVERY(tp->t_flags) &&
10912 	    (rack->rack_no_prr == 0) &&
10913 	    (entered_recovery == 0)) {
10914 		rack_update_prr(tp, rack, changed, th_ack);
10915 		if ((rsm && (rack->r_ctl.rc_prr_sndcnt >= ctf_fixed_maxseg(tp)) &&
10916 		     ((tcp_in_hpts(rack->rc_tp) == 0) &&
10917 		      ((rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT) == 0)))) {
10918 			/*
10919 			 * If you are pacing output you don't want
10920 			 * to override.
10921 			 */
10922 			rack->r_early = 0;
10923 			rack->r_ctl.rc_agg_early = 0;
10924 			rack->r_timer_override = 1;
10925 		}
10926 	}
10927 }
10928 
10929 static void
10930 rack_strike_dupack(struct tcp_rack *rack, tcp_seq th_ack)
10931 {
10932 	struct rack_sendmap *rsm;
10933 
10934 	rsm = TAILQ_FIRST(&rack->r_ctl.rc_tmap);
10935 	while (rsm) {
10936 		/*
10937 		 * We need to skip anything already set
10938 		 * to be retransmitted.
10939 		 */
10940 		if ((rsm->r_dupack >= DUP_ACK_THRESHOLD) ||
10941 		    (rsm->r_flags & RACK_MUST_RXT)) {
10942 			rsm = TAILQ_NEXT(rsm, r_tnext);
10943 			continue;
10944 		}
10945 		break;
10946 	}
10947 	if (rsm && (rsm->r_dupack < 0xff)) {
10948 		rsm->r_dupack++;
10949 		if (rsm->r_dupack >= DUP_ACK_THRESHOLD) {
10950 			struct timeval tv;
10951 			uint32_t cts;
10952 			/*
10953 			 * Here we see if we need to retransmit. For
10954 			 * a SACK type connection if enough time has passed
10955 			 * we will get a return of the rsm. For a non-sack
10956 			 * connection we will get the rsm returned if the
10957 			 * dupack value is 3 or more.
10958 			 */
10959 			cts = tcp_get_usecs(&tv);
10960 			rack->r_ctl.rc_resend = tcp_rack_output(rack->rc_tp, rack, cts);
10961 			if (rack->r_ctl.rc_resend != NULL) {
10962 				if (!IN_FASTRECOVERY(rack->rc_tp->t_flags)) {
10963 					rack_cong_signal(rack->rc_tp, CC_NDUPACK,
10964 							 th_ack,  __LINE__);
10965 				}
10966 				rack->r_wanted_output = 1;
10967 				rack->r_timer_override = 1;
10968 				rack_log_retran_reason(rack, rsm, __LINE__, 1, 3);
10969 			}
10970 		} else {
10971 			rack_log_retran_reason(rack, rsm, __LINE__, 0, 3);
10972 		}
10973 	}
10974 }
10975 
10976 static void
10977 rack_check_bottom_drag(struct tcpcb *tp,
10978 		       struct tcp_rack *rack,
10979 		       struct socket *so)
10980 {
10981 	/*
10982 	 * So what is dragging bottom?
10983 	 *
10984 	 * Dragging bottom means you were under pacing and had a
10985 	 * delay in processing inbound acks waiting on our pacing
10986 	 * timer to expire. While you were waiting all of the acknowledgments
10987 	 * for the packets you sent have arrived. This means we are pacing
10988 	 * way underneath the bottleneck to the point where our Goodput
10989 	 * measurements stop working, since they require more than one
10990 	 * ack (usually at least 8 packets worth with multiple acks so we can
10991 	 * gauge the inter-ack times). If that occurs we have a real problem
10992 	 * since we are stuck in a hole that we can't get out of without
10993 	 * something speeding us up.
10994 	 *
10995 	 * We also check to see if we are widdling down to just one segment
10996 	 * outstanding. If this occurs and we have room to send in our cwnd/rwnd
10997 	 * then we are adding the delayed ack interval into our measurments and
10998 	 * we need to speed up slightly.
10999 	 */
11000 	uint32_t segsiz, minseg;
11001 
11002 	segsiz = ctf_fixed_maxseg(tp);
11003 	minseg = segsiz;
11004 	if (tp->snd_max == tp->snd_una) {
11005 		/*
11006 		 * We are doing dynamic pacing and we are way
11007 		 * under. Basically everything got acked while
11008 		 * we were still waiting on the pacer to expire.
11009 		 *
11010 		 * This means we need to boost the b/w in
11011 		 * addition to any earlier boosting of
11012 		 * the multiplier.
11013 		 */
11014 		uint64_t lt_bw;
11015 
11016 		tcp_trace_point(rack->rc_tp, TCP_TP_PACED_BOTTOM);
11017 		lt_bw = rack_get_lt_bw(rack);
11018 		rack->rc_dragged_bottom = 1;
11019 		rack_validate_multipliers_at_or_above100(rack);
11020 		if ((rack->r_ctl.rack_rs.rs_flags & RACK_RTT_VALID) &&
11021 		    (rack->dis_lt_bw == 0) &&
11022 		    (rack->use_lesser_lt_bw == 0) &&
11023 		    (lt_bw > 0)) {
11024 			/*
11025 			 * Lets use the long-term b/w we have
11026 			 * been getting as a base.
11027 			 */
11028 			if (rack->rc_gp_filled == 0) {
11029 				if (lt_bw > ONE_POINT_TWO_MEG) {
11030 					/*
11031 					 * If we have no measurement
11032 					 * don't let us set in more than
11033 					 * 1.2Mbps. If we are still too
11034 					 * low after pacing with this we
11035 					 * will hopefully have a max b/w
11036 					 * available to sanity check things.
11037 					 */
11038 					lt_bw = ONE_POINT_TWO_MEG;
11039 				}
11040 				rack->r_ctl.rc_rtt_diff = 0;
11041 				rack->r_ctl.gp_bw = lt_bw;
11042 				rack->rc_gp_filled = 1;
11043 				if (rack->r_ctl.num_measurements < RACK_REQ_AVG)
11044 					rack->r_ctl.num_measurements = RACK_REQ_AVG;
11045 				rack_set_pace_segments(rack->rc_tp, rack, __LINE__, NULL);
11046 			} else if (lt_bw > rack->r_ctl.gp_bw) {
11047 				rack->r_ctl.rc_rtt_diff = 0;
11048 				if (rack->r_ctl.num_measurements < RACK_REQ_AVG)
11049 					rack->r_ctl.num_measurements = RACK_REQ_AVG;
11050 				rack->r_ctl.gp_bw = lt_bw;
11051 				rack_set_pace_segments(rack->rc_tp, rack, __LINE__, NULL);
11052 			} else
11053 				rack_increase_bw_mul(rack, -1, 0, 0, 1);
11054 			if ((rack->gp_ready == 0) &&
11055 			    (rack->r_ctl.num_measurements >= rack->r_ctl.req_measurements)) {
11056 				/* We have enough measurements now */
11057 				rack->gp_ready = 1;
11058 				if (rack->dgp_on ||
11059 				    rack->rack_hibeta)
11060 					rack_set_cc_pacing(rack);
11061 				if (rack->defer_options)
11062 					rack_apply_deferred_options(rack);
11063 			}
11064 		} else {
11065 			/*
11066 			 * zero rtt possibly?, settle for just an old increase.
11067 			 */
11068 			rack_increase_bw_mul(rack, -1, 0, 0, 1);
11069 		}
11070 	} else if ((IN_FASTRECOVERY(tp->t_flags) == 0) &&
11071 		   (sbavail(&so->so_snd) > max((segsiz * (4 + rack_req_segs)),
11072 					       minseg)) &&
11073 		   (rack->r_ctl.cwnd_to_use > max((segsiz * (rack_req_segs + 2)), minseg)) &&
11074 		   (tp->snd_wnd > max((segsiz * (rack_req_segs + 2)), minseg)) &&
11075 		   (ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked) <=
11076 		    (segsiz * rack_req_segs))) {
11077 		/*
11078 		 * We are doing dynamic GP pacing and
11079 		 * we have everything except 1MSS or less
11080 		 * bytes left out. We are still pacing away.
11081 		 * And there is data that could be sent, This
11082 		 * means we are inserting delayed ack time in
11083 		 * our measurements because we are pacing too slow.
11084 		 */
11085 		rack_validate_multipliers_at_or_above100(rack);
11086 		rack->rc_dragged_bottom = 1;
11087 		rack_increase_bw_mul(rack, -1, 0, 0, 1);
11088 	}
11089 }
11090 
11091 #ifdef TCP_REQUEST_TRK
11092 static void
11093 rack_log_hybrid(struct tcp_rack *rack, uint32_t seq,
11094 		struct tcp_sendfile_track *cur, uint8_t mod, int line, int err)
11095 {
11096 	int do_log;
11097 
11098 	do_log = tcp_bblogging_on(rack->rc_tp);
11099 	if (do_log == 0) {
11100 		if ((do_log = tcp_bblogging_point_on(rack->rc_tp, TCP_BBPOINT_REQ_LEVEL_LOGGING) )== 0)
11101 			return;
11102 		/* We only allow the three below with point logging on */
11103 		if ((mod != HYBRID_LOG_RULES_APP) &&
11104 		    (mod != HYBRID_LOG_RULES_SET) &&
11105 		    (mod != HYBRID_LOG_REQ_COMP))
11106 			return;
11107 
11108 	}
11109 	if (do_log) {
11110 		union tcp_log_stackspecific log;
11111 		struct timeval tv;
11112 
11113 		/* Convert our ms to a microsecond */
11114 		memset(&log, 0, sizeof(log));
11115 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
11116 		log.u_bbr.flex1 = seq;
11117 		log.u_bbr.cwnd_gain = line;
11118 		if (cur != NULL) {
11119 			uint64_t off;
11120 
11121 			log.u_bbr.flex2 = cur->start_seq;
11122 			log.u_bbr.flex3 = cur->end_seq;
11123 			log.u_bbr.flex4 = (uint32_t)((cur->localtime >> 32) & 0x00000000ffffffff);
11124 			log.u_bbr.flex5 = (uint32_t)(cur->localtime & 0x00000000ffffffff);
11125 			log.u_bbr.flex6 = cur->flags;
11126 			log.u_bbr.pkts_out = cur->hybrid_flags;
11127 			log.u_bbr.rttProp = cur->timestamp;
11128 			log.u_bbr.cur_del_rate = cur->cspr;
11129 			log.u_bbr.bw_inuse = cur->start;
11130 			log.u_bbr.applimited = (uint32_t)(cur->end & 0x00000000ffffffff);
11131 			log.u_bbr.delivered = (uint32_t)((cur->end >> 32) & 0x00000000ffffffff) ;
11132 			log.u_bbr.epoch = (uint32_t)(cur->deadline & 0x00000000ffffffff);
11133 			log.u_bbr.lt_epoch = (uint32_t)((cur->deadline >> 32) & 0x00000000ffffffff) ;
11134 			log.u_bbr.inhpts = 1;
11135 #ifdef TCP_REQUEST_TRK
11136 			off = (uint64_t)(cur) - (uint64_t)(&rack->rc_tp->t_tcpreq_info[0]);
11137 			log.u_bbr.use_lt_bw = (uint8_t)(off / sizeof(struct tcp_sendfile_track));
11138 #endif
11139 		} else {
11140 			log.u_bbr.flex2 = err;
11141 		}
11142 		/*
11143 		 * Fill in flex7 to be CHD (catchup|hybrid|DGP)
11144 		 */
11145 		log.u_bbr.flex7 = rack->rc_catch_up;
11146 		log.u_bbr.flex7 <<= 1;
11147 		log.u_bbr.flex7 |= rack->rc_hybrid_mode;
11148 		log.u_bbr.flex7 <<= 1;
11149 		log.u_bbr.flex7 |= rack->dgp_on;
11150 		/*
11151 		 * Compose bbr_state to be a bit wise 0000ADHF
11152 		 * where A is the always_pace flag
11153 		 * where D is the dgp_on flag
11154 		 * where H is the hybrid_mode on flag
11155 		 * where F is the use_fixed_rate flag.
11156 		 */
11157 		log.u_bbr.bbr_state = rack->rc_always_pace;
11158 		log.u_bbr.bbr_state <<= 1;
11159 		log.u_bbr.bbr_state |= rack->dgp_on;
11160 		log.u_bbr.bbr_state <<= 1;
11161 		log.u_bbr.bbr_state |= rack->rc_hybrid_mode;
11162 		log.u_bbr.bbr_state <<= 1;
11163 		log.u_bbr.bbr_state |= rack->use_fixed_rate;
11164 		log.u_bbr.flex8 = mod;
11165 		log.u_bbr.delRate = rack->r_ctl.bw_rate_cap;
11166 		log.u_bbr.bbr_substate = rack->r_ctl.client_suggested_maxseg;
11167 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
11168 		log.u_bbr.pkt_epoch = rack->rc_tp->tcp_hybrid_start;
11169 		log.u_bbr.lost = rack->rc_tp->tcp_hybrid_error;
11170 		log.u_bbr.pacing_gain = (uint16_t)rack->rc_tp->tcp_hybrid_stop;
11171 		tcp_log_event(rack->rc_tp, NULL,
11172 		    &rack->rc_inp->inp_socket->so_rcv,
11173 		    &rack->rc_inp->inp_socket->so_snd,
11174 		    TCP_HYBRID_PACING_LOG, 0,
11175 	            0, &log, false, NULL, __func__, __LINE__, &tv);
11176 	}
11177 }
11178 #endif
11179 
11180 #ifdef TCP_REQUEST_TRK
11181 static void
11182 rack_set_dgp_hybrid_mode(struct tcp_rack *rack, tcp_seq seq, uint32_t len, uint64_t cts)
11183 {
11184 	struct tcp_sendfile_track *rc_cur, *orig_ent;
11185 	struct tcpcb *tp;
11186 	int err = 0;
11187 
11188 	orig_ent = rack->r_ctl.rc_last_sft;
11189 	rc_cur = tcp_req_find_req_for_seq(rack->rc_tp, seq);
11190 	if (rc_cur == NULL) {
11191 		/* If not in the beginning what about the end piece */
11192 		if (rack->rc_hybrid_mode)
11193 			rack_log_hybrid(rack, seq, NULL, HYBRID_LOG_NO_RANGE, __LINE__, err);
11194 		rc_cur = tcp_req_find_req_for_seq(rack->rc_tp, (seq + len - 1));
11195 	} else {
11196 		err = 12345;
11197 	}
11198 	/* If we find no parameters we are in straight DGP mode */
11199 	if(rc_cur == NULL) {
11200 		/* None found for this seq, just DGP for now */
11201 		if (rack->rc_hybrid_mode) {
11202 			rack->r_ctl.client_suggested_maxseg = 0;
11203 			rack->rc_catch_up = 0;
11204 			if (rack->cspr_is_fcc == 0)
11205 				rack->r_ctl.bw_rate_cap = 0;
11206 			else
11207 				rack->r_ctl.fillcw_cap = rack_fillcw_bw_cap;
11208 		}
11209 		if (rack->rc_hybrid_mode) {
11210 			rack_log_hybrid(rack, (seq + len - 1), NULL, HYBRID_LOG_NO_RANGE, __LINE__, err);
11211 		}
11212 		if (rack->r_ctl.rc_last_sft) {
11213 			rack->r_ctl.rc_last_sft = NULL;
11214 		}
11215 		return;
11216 	}
11217 	if ((rc_cur->hybrid_flags & TCP_HYBRID_PACING_WASSET) == 0) {
11218 		/* This entry was never setup for hybrid pacing on/off etc */
11219 		if (rack->rc_hybrid_mode) {
11220 			rack->r_ctl.client_suggested_maxseg = 0;
11221 			rack->rc_catch_up = 0;
11222 			rack->r_ctl.bw_rate_cap = 0;
11223 		}
11224 		if (rack->r_ctl.rc_last_sft) {
11225 			rack->r_ctl.rc_last_sft = NULL;
11226 		}
11227 		if ((rc_cur->flags & TCP_TRK_TRACK_FLG_FSND) == 0) {
11228 			rc_cur->flags |= TCP_TRK_TRACK_FLG_FSND;
11229 			rc_cur->first_send = cts;
11230 			rc_cur->sent_at_fs = rack->rc_tp->t_sndbytes;
11231 			rc_cur->rxt_at_fs = rack->rc_tp->t_snd_rxt_bytes;
11232 		}
11233 		return;
11234 	}
11235 	/*
11236 	 * Ok if we have a new entry *or* have never
11237 	 * set up an entry we need to proceed. If
11238 	 * we have already set it up this entry we
11239 	 * just continue along with what we already
11240 	 * setup.
11241 	 */
11242 	tp = rack->rc_tp;
11243 	if ((rack->r_ctl.rc_last_sft != NULL) &&
11244 	    (rack->r_ctl.rc_last_sft == rc_cur)) {
11245 		/* Its already in place */
11246 		if (rack->rc_hybrid_mode)
11247 			rack_log_hybrid(rack, seq, rc_cur, HYBRID_LOG_ISSAME, __LINE__, 0);
11248 		return;
11249 	}
11250 	if (rack->rc_hybrid_mode == 0) {
11251 		rack->r_ctl.rc_last_sft = rc_cur;
11252 		if (orig_ent) {
11253 			orig_ent->sent_at_ls = rack->rc_tp->t_sndbytes;
11254 			orig_ent->rxt_at_ls = rack->rc_tp->t_snd_rxt_bytes;
11255 			orig_ent->flags |= TCP_TRK_TRACK_FLG_LSND;
11256 		}
11257 		rack_log_hybrid(rack, seq, rc_cur, HYBRID_LOG_RULES_APP, __LINE__, 0);
11258 		return;
11259 	}
11260 	if ((rc_cur->hybrid_flags & TCP_HYBRID_PACING_CSPR) && rc_cur->cspr){
11261 		/* Compensate for all the header overhead's */
11262 		if (rack->cspr_is_fcc == 0)
11263 			rack->r_ctl.bw_rate_cap	= rack_compensate_for_linerate(rack, rc_cur->cspr);
11264 		else
11265 			rack->r_ctl.fillcw_cap =  rack_compensate_for_linerate(rack, rc_cur->cspr);
11266 	} else {
11267 		if (rack->rc_hybrid_mode) {
11268 			if (rack->cspr_is_fcc == 0)
11269 				rack->r_ctl.bw_rate_cap = 0;
11270 			else
11271 				rack->r_ctl.fillcw_cap = rack_fillcw_bw_cap;
11272 		}
11273 	}
11274 	if (rc_cur->hybrid_flags & TCP_HYBRID_PACING_H_MS)
11275 		rack->r_ctl.client_suggested_maxseg = rc_cur->hint_maxseg;
11276 	else
11277 		rack->r_ctl.client_suggested_maxseg = 0;
11278 	if (rc_cur->timestamp == rack->r_ctl.last_tm_mark) {
11279 		/*
11280 		 * It is the same timestamp as the previous one
11281 		 * add the hybrid flag that will indicate we use
11282 		 * sendtime not arrival time for catch-up mode.
11283 		 */
11284 		rc_cur->hybrid_flags |= TCP_HYBRID_PACING_SENDTIME;
11285 	}
11286 	if ((rc_cur->hybrid_flags & TCP_HYBRID_PACING_CU) &&
11287 	    (rc_cur->cspr > 0)) {
11288 		uint64_t len;
11289 
11290 		rack->rc_catch_up = 1;
11291 		/*
11292 		 * Calculate the deadline time, first set the
11293 		 * time to when the request arrived.
11294 		 */
11295 		if (rc_cur->hybrid_flags & TCP_HYBRID_PACING_SENDTIME) {
11296 			/*
11297 			 * For cases where its a duplicate tm (we received more
11298 			 * than one request for a tm) we want to use now, the point
11299 			 * where we are just sending the first bit of the request.
11300 			 */
11301 			rc_cur->deadline = cts;
11302 		} else {
11303 			/*
11304 			 * Here we have a different tm from the last request
11305 			 * so we want to use arrival time as our base.
11306 			 */
11307 			rc_cur->deadline = rc_cur->localtime;
11308 		}
11309 		/*
11310 		 * Next calculate the length and compensate for
11311 		 * TLS if need be.
11312 		 */
11313 		len = rc_cur->end - rc_cur->start;
11314 		if (tp->t_inpcb.inp_socket->so_snd.sb_tls_info) {
11315 			/*
11316 			 * This session is doing TLS. Take a swag guess
11317 			 * at the overhead.
11318 			 */
11319 			len += tcp_estimate_tls_overhead(tp->t_inpcb.inp_socket, len);
11320 		}
11321 		/*
11322 		 * Now considering the size, and the cspr, what is the time that
11323 		 * would be required at the cspr rate. Here we use the raw
11324 		 * cspr value since the client only looks at the raw data. We
11325 		 * do use len which includes TLS overhead, but not the TCP/IP etc.
11326 		 * That will get made up for in the CU pacing rate set.
11327 		 */
11328 		len *= HPTS_USEC_IN_SEC;
11329 		len /= rc_cur->cspr;
11330 		rc_cur->deadline += len;
11331 	} else {
11332 		rack->rc_catch_up = 0;
11333 		rc_cur->deadline = 0;
11334 	}
11335 	if (rack->r_ctl.client_suggested_maxseg != 0) {
11336 		/*
11337 		 * We need to reset the max pace segs if we have a
11338 		 * client_suggested_maxseg.
11339 		 */
11340 		rack_set_pace_segments(tp, rack, __LINE__, NULL);
11341 	}
11342 	if (orig_ent) {
11343 		orig_ent->sent_at_ls = rack->rc_tp->t_sndbytes;
11344 		orig_ent->rxt_at_ls = rack->rc_tp->t_snd_rxt_bytes;
11345 		orig_ent->flags |= TCP_TRK_TRACK_FLG_LSND;
11346 	}
11347 	rack_log_hybrid(rack, seq, rc_cur, HYBRID_LOG_RULES_APP, __LINE__, 0);
11348 	/* Remember it for next time and for CU mode */
11349 	rack->r_ctl.rc_last_sft = rc_cur;
11350 	rack->r_ctl.last_tm_mark = rc_cur->timestamp;
11351 }
11352 #endif
11353 
11354 static void
11355 rack_chk_req_and_hybrid_on_out(struct tcp_rack *rack, tcp_seq seq, uint32_t len, uint64_t cts)
11356 {
11357 #ifdef TCP_REQUEST_TRK
11358 	struct tcp_sendfile_track *ent;
11359 
11360 	ent = rack->r_ctl.rc_last_sft;
11361 	if ((ent == NULL) ||
11362 	    (ent->flags == TCP_TRK_TRACK_FLG_EMPTY) ||
11363 	    (SEQ_GEQ(seq, ent->end_seq))) {
11364 		/* Time to update the track. */
11365 		rack_set_dgp_hybrid_mode(rack, seq, len, cts);
11366 		ent = rack->r_ctl.rc_last_sft;
11367 	}
11368 	/* Out of all */
11369 	if (ent == NULL) {
11370 		return;
11371 	}
11372 	if (SEQ_LT(ent->end_seq, (seq + len))) {
11373 		/*
11374 		 * This is the case where our end_seq guess
11375 		 * was wrong. This is usually due to TLS having
11376 		 * more bytes then our guess. It could also be the
11377 		 * case that the client sent in two requests closely
11378 		 * and the SB is full of both so we are sending part
11379 		 * of each (end|beg). In such a case lets move this
11380 		 * guys end to match the end of this send. That
11381 		 * way it will complete when all of it is acked.
11382 		 */
11383 		ent->end_seq = (seq + len);
11384 		if (rack->rc_hybrid_mode)
11385 			rack_log_hybrid_bw(rack, seq, len, 0, 0, HYBRID_LOG_EXTEND, 0, ent, __LINE__);
11386 	}
11387 	/* Now validate we have set the send time of this one */
11388 	if ((ent->flags & TCP_TRK_TRACK_FLG_FSND) == 0) {
11389 		ent->flags |= TCP_TRK_TRACK_FLG_FSND;
11390 		ent->first_send = cts;
11391 		ent->sent_at_fs = rack->rc_tp->t_sndbytes;
11392 		ent->rxt_at_fs = rack->rc_tp->t_snd_rxt_bytes;
11393 	}
11394 #endif
11395 }
11396 
11397 static void
11398 rack_gain_for_fastoutput(struct tcp_rack *rack, struct tcpcb *tp, struct socket *so, uint32_t acked_amount)
11399 {
11400 	/*
11401 	 * The fast output path is enabled and we
11402 	 * have moved the cumack forward. Lets see if
11403 	 * we can expand forward the fast path length by
11404 	 * that amount. What we would ideally like to
11405 	 * do is increase the number of bytes in the
11406 	 * fast path block (left_to_send) by the
11407 	 * acked amount. However we have to gate that
11408 	 * by two factors:
11409 	 * 1) The amount outstanding and the rwnd of the peer
11410 	 *    (i.e. we don't want to exceed the rwnd of the peer).
11411 	 *    <and>
11412 	 * 2) The amount of data left in the socket buffer (i.e.
11413 	 *    we can't send beyond what is in the buffer).
11414 	 *
11415 	 * Note that this does not take into account any increase
11416 	 * in the cwnd. We will only extend the fast path by
11417 	 * what was acked.
11418 	 */
11419 	uint32_t new_total, gating_val;
11420 
11421 	new_total = acked_amount + rack->r_ctl.fsb.left_to_send;
11422 	gating_val = min((sbavail(&so->so_snd) - (tp->snd_max - tp->snd_una)),
11423 			 (tp->snd_wnd - (tp->snd_max - tp->snd_una)));
11424 	if (new_total <= gating_val) {
11425 		/* We can increase left_to_send by the acked amount */
11426 		counter_u64_add(rack_extended_rfo, 1);
11427 		rack->r_ctl.fsb.left_to_send = new_total;
11428 		KASSERT((rack->r_ctl.fsb.left_to_send <= (sbavail(&rack->rc_inp->inp_socket->so_snd) - (tp->snd_max - tp->snd_una))),
11429 			("rack:%p left_to_send:%u sbavail:%u out:%u",
11430 			 rack, rack->r_ctl.fsb.left_to_send,
11431 			 sbavail(&rack->rc_inp->inp_socket->so_snd),
11432 			 (tp->snd_max - tp->snd_una)));
11433 
11434 	}
11435 }
11436 
11437 static void
11438 rack_adjust_sendmap_head(struct tcp_rack *rack, struct sockbuf *sb)
11439 {
11440 	/*
11441 	 * Here any sendmap entry that points to the
11442 	 * beginning mbuf must be adjusted to the correct
11443 	 * offset. This must be called with:
11444 	 * 1) The socket buffer locked
11445 	 * 2) snd_una adjusted to its new position.
11446 	 *
11447 	 * Note that (2) implies rack_ack_received has also
11448 	 * been called and all the sbcut's have been done.
11449 	 *
11450 	 * We grab the first mbuf in the socket buffer and
11451 	 * then go through the front of the sendmap, recalculating
11452 	 * the stored offset for any sendmap entry that has
11453 	 * that mbuf. We must use the sb functions to do this
11454 	 * since its possible an add was done has well as
11455 	 * the subtraction we may have just completed. This should
11456 	 * not be a penalty though, since we just referenced the sb
11457 	 * to go in and trim off the mbufs that we freed (of course
11458 	 * there will be a penalty for the sendmap references though).
11459 	 *
11460 	 * Note also with INVARIANT on, we validate with a KASSERT
11461 	 * that the first sendmap entry has a soff of 0.
11462 	 *
11463 	 */
11464 	struct mbuf *m;
11465 	struct rack_sendmap *rsm;
11466 	tcp_seq snd_una;
11467 #ifdef INVARIANTS
11468 	int first_processed = 0;
11469 #endif
11470 
11471 	snd_una = rack->rc_tp->snd_una;
11472 	SOCKBUF_LOCK_ASSERT(sb);
11473 	m = sb->sb_mb;
11474 	rsm = tqhash_min(rack->r_ctl.tqh);
11475 	if ((rsm == NULL) || (m == NULL)) {
11476 		/* Nothing outstanding */
11477 		return;
11478 	}
11479 	/* The very first RSM's mbuf must point to the head mbuf in the sb */
11480 	KASSERT((rsm->m == m),
11481 		("Rack:%p sb:%p rsm:%p -- first rsm mbuf not aligned to sb",
11482 		 rack, sb, rsm));
11483 	while (rsm->m && (rsm->m == m)) {
11484 		/* one to adjust */
11485 #ifdef INVARIANTS
11486 		struct mbuf *tm;
11487 		uint32_t soff;
11488 
11489 		tm = sbsndmbuf(sb, (rsm->r_start - snd_una), &soff);
11490 		if ((rsm->orig_m_len != m->m_len) ||
11491 		    (rsm->orig_t_space != M_TRAILINGROOM(m))){
11492 			rack_adjust_orig_mlen(rsm);
11493 		}
11494 		if (first_processed == 0) {
11495 			KASSERT((rsm->soff == 0),
11496 				("Rack:%p rsm:%p -- rsm at head but soff not zero",
11497 				 rack, rsm));
11498 			first_processed = 1;
11499 		}
11500 		if ((rsm->soff != soff) || (rsm->m != tm)) {
11501 			/*
11502 			 * This is not a fatal error, we anticipate it
11503 			 * might happen (the else code), so we count it here
11504 			 * so that under invariant we can see that it really
11505 			 * does happen.
11506 			 */
11507 			counter_u64_add(rack_adjust_map_bw, 1);
11508 		}
11509 		rsm->m = tm;
11510 		rsm->soff = soff;
11511 		if (tm) {
11512 			rsm->orig_m_len = rsm->m->m_len;
11513 			rsm->orig_t_space = M_TRAILINGROOM(rsm->m);
11514 		} else {
11515 			rsm->orig_m_len = 0;
11516 			rsm->orig_t_space = 0;
11517 		}
11518 #else
11519 		rsm->m = sbsndmbuf(sb, (rsm->r_start - snd_una), &rsm->soff);
11520 		if (rsm->m) {
11521 			rsm->orig_m_len = rsm->m->m_len;
11522 			rsm->orig_t_space = M_TRAILINGROOM(rsm->m);
11523 		} else {
11524 			rsm->orig_m_len = 0;
11525 			rsm->orig_t_space = 0;
11526 		}
11527 #endif
11528 		rsm = tqhash_next(rack->r_ctl.tqh, rsm);
11529 		if (rsm == NULL)
11530 			break;
11531 	}
11532 }
11533 
11534 #ifdef TCP_REQUEST_TRK
11535 static inline void
11536 rack_req_check_for_comp(struct tcp_rack *rack, tcp_seq th_ack)
11537 {
11538 	struct tcp_sendfile_track *ent;
11539 	int i;
11540 
11541 	if ((rack->rc_hybrid_mode == 0) &&
11542 	    (tcp_bblogging_point_on(rack->rc_tp, TCP_BBPOINT_REQ_LEVEL_LOGGING) == 0)) {
11543 		/*
11544 		 * Just do normal completions hybrid pacing is not on
11545 		 * and CLDL is off as well.
11546 		 */
11547 		tcp_req_check_for_comp(rack->rc_tp, th_ack);
11548 		return;
11549 	}
11550 	/*
11551 	 * Originally I was just going to find the th_ack associated
11552 	 * with an entry. But then I realized a large strech ack could
11553 	 * in theory ack two or more requests at once. So instead we
11554 	 * need to find all entries that are completed by th_ack not
11555 	 * just a single entry and do our logging.
11556 	 */
11557 	ent = tcp_req_find_a_req_that_is_completed_by(rack->rc_tp, th_ack, &i);
11558 	while (ent != NULL) {
11559 		/*
11560 		 * We may be doing hybrid pacing or CLDL and need more details possibly
11561 		 * so we do it manually instead of calling
11562 		 * tcp_req_check_for_comp()
11563 		 */
11564 		uint64_t laa, tim, data, cbw, ftim;
11565 
11566 		/* Ok this ack frees it */
11567 		rack_log_hybrid(rack, th_ack,
11568 				ent, HYBRID_LOG_REQ_COMP, __LINE__, 0);
11569 		rack_log_hybrid_sends(rack, ent, __LINE__);
11570 		/* calculate the time based on the ack arrival */
11571 		data = ent->end - ent->start;
11572 		laa = tcp_tv_to_lusec(&rack->r_ctl.act_rcv_time);
11573 		if (ent->flags & TCP_TRK_TRACK_FLG_FSND) {
11574 			if (ent->first_send > ent->localtime)
11575 				ftim = ent->first_send;
11576 			else
11577 				ftim = ent->localtime;
11578 		} else {
11579 			/* TSNH */
11580 			ftim = ent->localtime;
11581 		}
11582 		if (laa > ent->localtime)
11583 			tim = laa - ftim;
11584 		else
11585 			tim = 0;
11586 		cbw = data * HPTS_USEC_IN_SEC;
11587 		if (tim > 0)
11588 			cbw /= tim;
11589 		else
11590 			cbw = 0;
11591 		rack_log_hybrid_bw(rack, th_ack, cbw, tim, data, HYBRID_LOG_BW_MEASURE, 0, ent, __LINE__);
11592 		/*
11593 		 * Check to see if we are freeing what we are pointing to send wise
11594 		 * if so be sure to NULL the pointer so we know we are no longer
11595 		 * set to anything.
11596 		 */
11597 		if (ent == rack->r_ctl.rc_last_sft) {
11598 			rack->r_ctl.rc_last_sft = NULL;
11599 			if (rack->rc_hybrid_mode) {
11600 				rack->rc_catch_up = 0;
11601 				if (rack->cspr_is_fcc == 0)
11602 					rack->r_ctl.bw_rate_cap = 0;
11603 				else
11604 					rack->r_ctl.fillcw_cap = rack_fillcw_bw_cap;
11605 				rack->r_ctl.client_suggested_maxseg = 0;
11606 			}
11607 		}
11608 		/* Generate the log that the tcp_netflix call would have */
11609 		tcp_req_log_req_info(rack->rc_tp, ent,
11610 				      i, TCP_TRK_REQ_LOG_FREED, 0, 0);
11611 		/* Free it and see if there is another one */
11612 		tcp_req_free_a_slot(rack->rc_tp, ent);
11613 		ent = tcp_req_find_a_req_that_is_completed_by(rack->rc_tp, th_ack, &i);
11614 	}
11615 }
11616 #endif
11617 
11618 
11619 /*
11620  * Return value of 1, we do not need to call rack_process_data().
11621  * return value of 0, rack_process_data can be called.
11622  * For ret_val if its 0 the TCP is locked, if its non-zero
11623  * its unlocked and probably unsafe to touch the TCB.
11624  */
11625 static int
11626 rack_process_ack(struct mbuf *m, struct tcphdr *th, struct socket *so,
11627     struct tcpcb *tp, struct tcpopt *to,
11628     uint32_t tiwin, int32_t tlen,
11629     int32_t * ofia, int32_t thflags, int32_t *ret_val, int32_t orig_tlen)
11630 {
11631 	int32_t ourfinisacked = 0;
11632 	int32_t nsegs, acked_amount;
11633 	int32_t acked;
11634 	struct mbuf *mfree;
11635 	struct tcp_rack *rack;
11636 	int32_t under_pacing = 0;
11637 	int32_t post_recovery = 0;
11638 	uint32_t p_cwnd;
11639 
11640 	INP_WLOCK_ASSERT(tptoinpcb(tp));
11641 
11642 	rack = (struct tcp_rack *)tp->t_fb_ptr;
11643 	if (SEQ_GEQ(tp->snd_una, tp->iss + (65535 << tp->snd_scale))) {
11644 		/* Checking SEG.ACK against ISS is definitely redundant. */
11645 		tp->t_flags2 |= TF2_NO_ISS_CHECK;
11646 	}
11647 	if (!V_tcp_insecure_ack) {
11648 		tcp_seq seq_min;
11649 		bool ghost_ack_check;
11650 
11651 		if (tp->t_flags2 & TF2_NO_ISS_CHECK) {
11652 			/* Check for too old ACKs (RFC 5961, Section 5.2). */
11653 			seq_min = tp->snd_una - tp->max_sndwnd;
11654 			ghost_ack_check = false;
11655 		} else {
11656 			if (SEQ_GT(tp->iss + 1, tp->snd_una - tp->max_sndwnd)) {
11657 				/* Checking for ghost ACKs is stricter. */
11658 				seq_min = tp->iss + 1;
11659 				ghost_ack_check = true;
11660 			} else {
11661 				/*
11662 				 * Checking for too old ACKs (RFC 5961,
11663 				 * Section 5.2) is stricter.
11664 				 */
11665 				seq_min = tp->snd_una - tp->max_sndwnd;
11666 				ghost_ack_check = false;
11667 			}
11668 		}
11669 		if (SEQ_LT(th->th_ack, seq_min)) {
11670 			if (ghost_ack_check)
11671 				TCPSTAT_INC(tcps_rcvghostack);
11672 			else
11673 				TCPSTAT_INC(tcps_rcvacktooold);
11674 			/* Send challenge ACK. */
11675 			ctf_do_dropafterack(m, tp, th, thflags, tlen, ret_val);
11676 			rack->r_wanted_output = 1;
11677 			return (1);
11678 		}
11679 	}
11680 	if (SEQ_GT(th->th_ack, tp->snd_max)) {
11681 		ctf_do_dropafterack(m, tp, th, thflags, tlen, ret_val);
11682 		rack->r_wanted_output = 1;
11683 		return (1);
11684 	}
11685 	if (rack->gp_ready &&
11686 	    (rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT)) {
11687 		under_pacing = 1;
11688 	}
11689 	if (SEQ_GEQ(th->th_ack, tp->snd_una) || to->to_nsacks) {
11690 		int in_rec, dup_ack_struck = 0;
11691 		int dsack_seen = 0, sacks_seen = 0;
11692 
11693 		in_rec = IN_FASTRECOVERY(tp->t_flags);
11694 		if (rack->rc_in_persist) {
11695 			tp->t_rxtshift = 0;
11696 			RACK_TCPT_RANGESET(tp->t_rxtcur, RACK_REXMTVAL(tp),
11697 				      rack_rto_min, rack_rto_max, rack->r_ctl.timer_slop);
11698 		}
11699 
11700 		if ((th->th_ack == tp->snd_una) &&
11701 		    (tiwin == tp->snd_wnd) &&
11702 		    (orig_tlen == 0) &&
11703 		    ((to->to_flags & TOF_SACK) == 0)) {
11704 			rack_strike_dupack(rack, th->th_ack);
11705 			dup_ack_struck = 1;
11706 		}
11707 		rack_log_ack(tp, to, th, ((in_rec == 0) && IN_FASTRECOVERY(tp->t_flags)),
11708 			     dup_ack_struck, &dsack_seen, &sacks_seen);
11709 
11710 	}
11711 	if (__predict_false(SEQ_LEQ(th->th_ack, tp->snd_una))) {
11712 		/*
11713 		 * Old ack, behind (or duplicate to) the last one rcv'd
11714 		 * Note: We mark reordering is occuring if its
11715 		 * less than and we have not closed our window.
11716 		 */
11717 		if (SEQ_LT(th->th_ack, tp->snd_una) && (sbspace(&so->so_rcv) > ctf_fixed_maxseg(tp))) {
11718 			rack->r_ctl.rc_reorder_ts = tcp_tv_to_usec(&rack->r_ctl.act_rcv_time);
11719 			if (rack->r_ctl.rc_reorder_ts == 0)
11720 				rack->r_ctl.rc_reorder_ts = 1;
11721 		}
11722 		return (0);
11723 	}
11724 	/*
11725 	 * If we reach this point, ACK is not a duplicate, i.e., it ACKs
11726 	 * something we sent.
11727 	 */
11728 	if (tp->t_flags & TF_NEEDSYN) {
11729 		/*
11730 		 * T/TCP: Connection was half-synchronized, and our SYN has
11731 		 * been ACK'd (so connection is now fully synchronized).  Go
11732 		 * to non-starred state, increment snd_una for ACK of SYN,
11733 		 * and check if we can do window scaling.
11734 		 */
11735 		tp->t_flags &= ~TF_NEEDSYN;
11736 		tp->snd_una++;
11737 		/* Do window scaling? */
11738 		if ((tp->t_flags & (TF_RCVD_SCALE | TF_REQ_SCALE)) ==
11739 		    (TF_RCVD_SCALE | TF_REQ_SCALE)) {
11740 			tp->rcv_scale = tp->request_r_scale;
11741 			/* Send window already scaled. */
11742 		}
11743 	}
11744 	nsegs = max(1, m->m_pkthdr.lro_nsegs);
11745 
11746 	acked = BYTES_THIS_ACK(tp, th);
11747 	if (acked) {
11748 		/*
11749 		 * Any time we move the cum-ack forward clear
11750 		 * keep-alive tied probe-not-answered. The
11751 		 * persists clears its own on entry.
11752 		 */
11753 		rack->probe_not_answered = 0;
11754 	}
11755 	KMOD_TCPSTAT_ADD(tcps_rcvackpack, nsegs);
11756 	KMOD_TCPSTAT_ADD(tcps_rcvackbyte, acked);
11757 	/*
11758 	 * If we just performed our first retransmit, and the ACK arrives
11759 	 * within our recovery window, then it was a mistake to do the
11760 	 * retransmit in the first place.  Recover our original cwnd and
11761 	 * ssthresh, and proceed to transmit where we left off.
11762 	 */
11763 	if ((tp->t_flags & TF_PREVVALID) &&
11764 	    ((tp->t_flags & TF_RCVD_TSTMP) == 0)) {
11765 		tp->t_flags &= ~TF_PREVVALID;
11766 		if (tp->t_rxtshift == 1 &&
11767 		    (int)(ticks - tp->t_badrxtwin) < 0)
11768 			rack_cong_signal(tp, CC_RTO_ERR, th->th_ack, __LINE__);
11769 	}
11770 	if (acked) {
11771 		/* assure we are not backed off */
11772 		tp->t_rxtshift = 0;
11773 		RACK_TCPT_RANGESET(tp->t_rxtcur, RACK_REXMTVAL(tp),
11774 			      rack_rto_min, rack_rto_max, rack->r_ctl.timer_slop);
11775 		rack->rc_tlp_in_progress = 0;
11776 		rack->r_ctl.rc_tlp_cnt_out = 0;
11777 		/*
11778 		 * If it is the RXT timer we want to
11779 		 * stop it, so we can restart a TLP.
11780 		 */
11781 		if (rack->r_ctl.rc_hpts_flags & PACE_TMR_RXT)
11782 			rack_timer_cancel(tp, rack, rack->r_ctl.rc_rcvtime, __LINE__);
11783 #ifdef TCP_REQUEST_TRK
11784 		rack_req_check_for_comp(rack, th->th_ack);
11785 #endif
11786 	}
11787 	/*
11788 	 * If we have a timestamp reply, update smoothed round trip time. If
11789 	 * no timestamp is present but transmit timer is running and timed
11790 	 * sequence number was acked, update smoothed round trip time. Since
11791 	 * we now have an rtt measurement, cancel the timer backoff (cf.,
11792 	 * Phil Karn's retransmit alg.). Recompute the initial retransmit
11793 	 * timer.
11794 	 *
11795 	 * Some boxes send broken timestamp replies during the SYN+ACK
11796 	 * phase, ignore timestamps of 0 or we could calculate a huge RTT
11797 	 * and blow up the retransmit timer.
11798 	 */
11799 	/*
11800 	 * If all outstanding data is acked, stop retransmit timer and
11801 	 * remember to restart (more output or persist). If there is more
11802 	 * data to be acked, restart retransmit timer, using current
11803 	 * (possibly backed-off) value.
11804 	 */
11805 	if (acked == 0) {
11806 		if (ofia)
11807 			*ofia = ourfinisacked;
11808 		return (0);
11809 	}
11810 	if (IN_RECOVERY(tp->t_flags)) {
11811 		if (SEQ_LT(th->th_ack, tp->snd_recover) &&
11812 		    (SEQ_LT(th->th_ack, tp->snd_max))) {
11813 			tcp_rack_partialack(tp);
11814 		} else {
11815 			rack_post_recovery(tp, th->th_ack);
11816 			post_recovery = 1;
11817 			/*
11818 			 * Grab the segsiz, multiply by 2 and add the snd_cwnd
11819 			 * that is the max the CC should add if we are exiting
11820 			 * recovery and doing a late add.
11821 			 */
11822 			p_cwnd = min(ctf_fixed_maxseg(tp), rack->r_ctl.rc_pace_min_segs);
11823 			p_cwnd <<= 1;
11824 			p_cwnd += tp->snd_cwnd;
11825 		}
11826 	} else if ((rack->rto_from_rec == 1) &&
11827 		   SEQ_GEQ(th->th_ack, tp->snd_recover)) {
11828 		/*
11829 		 * We were in recovery, hit a rxt timeout
11830 		 * and never re-entered recovery. The timeout(s)
11831 		 * made up all the lost data. In such a case
11832 		 * we need to clear the rto_from_rec flag.
11833 		 */
11834 		rack->rto_from_rec = 0;
11835 	}
11836 	/*
11837 	 * Let the congestion control algorithm update congestion control
11838 	 * related information. This typically means increasing the
11839 	 * congestion window.
11840 	 */
11841 	rack_ack_received(tp, rack, th->th_ack, nsegs, CC_ACK, post_recovery);
11842 	if (post_recovery &&
11843 	    (tp->snd_cwnd > p_cwnd)) {
11844 		/* Must be non-newreno (cubic) getting too ahead of itself */
11845 		tp->snd_cwnd = p_cwnd;
11846 	}
11847 	SOCK_SENDBUF_LOCK(so);
11848 	acked_amount = min(acked, (int)sbavail(&so->so_snd));
11849 	tp->snd_wnd -= acked_amount;
11850 	mfree = sbcut_locked(&so->so_snd, acked_amount);
11851 	if ((sbused(&so->so_snd) == 0) &&
11852 	    (acked > acked_amount) &&
11853 	    (tp->t_state >= TCPS_FIN_WAIT_1) &&
11854 	    (tp->t_flags & TF_SENTFIN)) {
11855 		/*
11856 		 * We must be sure our fin
11857 		 * was sent and acked (we can be
11858 		 * in FIN_WAIT_1 without having
11859 		 * sent the fin).
11860 		 */
11861 		ourfinisacked = 1;
11862 	}
11863 	tp->snd_una = th->th_ack;
11864 	/* wakeups? */
11865 	if (acked_amount && sbavail(&so->so_snd))
11866 		rack_adjust_sendmap_head(rack, &so->so_snd);
11867 	rack_log_wakeup(tp,rack, &so->so_snd, acked, 2);
11868 	/* NB: sowwakeup_locked() does an implicit unlock. */
11869 	sowwakeup_locked(so);
11870 	m_freem(mfree);
11871 	if (SEQ_GT(tp->snd_una, tp->snd_recover))
11872 		tp->snd_recover = tp->snd_una;
11873 
11874 	if (SEQ_LT(tp->snd_nxt, tp->snd_max)) {
11875 		tp->snd_nxt = tp->snd_max;
11876 	}
11877 	if (under_pacing &&
11878 	    (rack->use_fixed_rate == 0) &&
11879 	    (rack->in_probe_rtt == 0) &&
11880 	    rack->rc_gp_dyn_mul &&
11881 	    rack->rc_always_pace) {
11882 		/* Check if we are dragging bottom */
11883 		rack_check_bottom_drag(tp, rack, so);
11884 	}
11885 	if (tp->snd_una == tp->snd_max) {
11886 		/* Nothing left outstanding */
11887 		tp->t_flags &= ~TF_PREVVALID;
11888 		if (rack->r_ctl.rc_went_idle_time == 0)
11889 			rack->r_ctl.rc_went_idle_time = 1;
11890 		rack->r_ctl.retran_during_recovery = 0;
11891 		rack->r_ctl.dsack_byte_cnt = 0;
11892 		rack_log_progress_event(rack, tp, 0, PROGRESS_CLEAR, __LINE__);
11893 		if (sbavail(&tptosocket(tp)->so_snd) == 0)
11894 			tp->t_acktime = 0;
11895 		rack_timer_cancel(tp, rack, rack->r_ctl.rc_rcvtime, __LINE__);
11896 		rack->rc_suspicious = 0;
11897 		/* Set need output so persist might get set */
11898 		rack->r_wanted_output = 1;
11899 		sack_filter_clear(&rack->r_ctl.rack_sf, tp->snd_una);
11900 		if ((tp->t_state >= TCPS_FIN_WAIT_1) &&
11901 		    (sbavail(&so->so_snd) == 0) &&
11902 		    (tp->t_flags2 & TF2_DROP_AF_DATA)) {
11903 			/*
11904 			 * The socket was gone and the
11905 			 * peer sent data (now or in the past), time to
11906 			 * reset him.
11907 			 */
11908 			*ret_val = 1;
11909 			/* tcp_close will kill the inp pre-log the Reset */
11910 			tcp_log_end_status(tp, TCP_EI_STATUS_SERVER_RST);
11911 			tp = tcp_close(tp);
11912 			ctf_do_dropwithreset(m, tp, th, tlen);
11913 			return (1);
11914 		}
11915 	}
11916 	if (ofia)
11917 		*ofia = ourfinisacked;
11918 	return (0);
11919 }
11920 
11921 
11922 static void
11923 rack_log_collapse(struct tcp_rack *rack, uint32_t cnt, uint32_t split, uint32_t out, int line,
11924 		  int dir, uint32_t flags, struct rack_sendmap *rsm)
11925 {
11926 	if (tcp_bblogging_on(rack->rc_tp)) {
11927 		union tcp_log_stackspecific log;
11928 		struct timeval tv;
11929 
11930 		memset(&log, 0, sizeof(log));
11931 		log.u_bbr.flex1 = cnt;
11932 		log.u_bbr.flex2 = split;
11933 		log.u_bbr.flex3 = out;
11934 		log.u_bbr.flex4 = line;
11935 		log.u_bbr.flex5 = rack->r_must_retran;
11936 		log.u_bbr.flex6 = flags;
11937 		log.u_bbr.flex7 = rack->rc_has_collapsed;
11938 		log.u_bbr.flex8 = dir;	/*
11939 					 * 1 is collapsed, 0 is uncollapsed,
11940 					 * 2 is log of a rsm being marked, 3 is a split.
11941 					 */
11942 		if (rsm == NULL)
11943 			log.u_bbr.rttProp = 0;
11944 		else
11945 			log.u_bbr.rttProp = (uintptr_t)rsm;
11946 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
11947 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
11948 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
11949 		    &rack->rc_inp->inp_socket->so_rcv,
11950 		    &rack->rc_inp->inp_socket->so_snd,
11951 		    TCP_RACK_LOG_COLLAPSE, 0,
11952 		    0, &log, false, &tv);
11953 	}
11954 }
11955 
11956 static void
11957 rack_collapsed_window(struct tcp_rack *rack, uint32_t out, tcp_seq th_ack, int line)
11958 {
11959 	/*
11960 	 * Here all we do is mark the collapsed point and set the flag.
11961 	 * This may happen again and again, but there is no
11962 	 * sense splitting our map until we know where the
11963 	 * peer finally lands in the collapse.
11964 	 */
11965 	tcp_trace_point(rack->rc_tp, TCP_TP_COLLAPSED_WND);
11966 	if ((rack->rc_has_collapsed == 0) ||
11967 	    (rack->r_ctl.last_collapse_point != (th_ack + rack->rc_tp->snd_wnd)))
11968 		counter_u64_add(rack_collapsed_win_seen, 1);
11969 	rack->r_ctl.last_collapse_point = th_ack + rack->rc_tp->snd_wnd;
11970 	rack->r_ctl.high_collapse_point = rack->rc_tp->snd_max;
11971 	rack->rc_has_collapsed = 1;
11972 	rack->r_collapse_point_valid = 1;
11973 	rack_log_collapse(rack, 0, th_ack, rack->r_ctl.last_collapse_point, line, 1, 0, NULL);
11974 }
11975 
11976 static void
11977 rack_un_collapse_window(struct tcp_rack *rack, int line)
11978 {
11979 	struct rack_sendmap *nrsm, *rsm;
11980 	int cnt = 0, split = 0;
11981 	int insret __diagused;
11982 
11983 
11984 	tcp_trace_point(rack->rc_tp, TCP_TP_COLLAPSED_WND);
11985 	rack->rc_has_collapsed = 0;
11986 	rsm = tqhash_find(rack->r_ctl.tqh, rack->r_ctl.last_collapse_point);
11987 	if (rsm == NULL) {
11988 		/* Nothing to do maybe the peer ack'ed it all */
11989 		rack_log_collapse(rack, 0, 0, ctf_outstanding(rack->rc_tp), line, 0, 0, NULL);
11990 		return;
11991 	}
11992 	/* Now do we need to split this one? */
11993 	if (SEQ_GT(rack->r_ctl.last_collapse_point, rsm->r_start)) {
11994 		rack_log_collapse(rack, rsm->r_start, rsm->r_end,
11995 				  rack->r_ctl.last_collapse_point, line, 3, rsm->r_flags, rsm);
11996 		nrsm = rack_alloc_limit(rack, RACK_LIMIT_TYPE_SPLIT);
11997 		if (nrsm == NULL) {
11998 			/* We can't get a rsm, mark all? */
11999 			nrsm = rsm;
12000 			goto no_split;
12001 		}
12002 		/* Clone it */
12003 		split = 1;
12004 		rack_clone_rsm(rack, nrsm, rsm, rack->r_ctl.last_collapse_point);
12005 #ifndef INVARIANTS
12006 		(void)tqhash_insert(rack->r_ctl.tqh, nrsm);
12007 #else
12008 		if ((insret = tqhash_insert(rack->r_ctl.tqh, nrsm)) != 0) {
12009 			panic("Insert in tailq_hash of %p fails ret:%d rack:%p rsm:%p",
12010 			      nrsm, insret, rack, rsm);
12011 		}
12012 #endif
12013 		rack_log_map_chg(rack->rc_tp, rack, NULL, rsm, nrsm, MAP_SPLIT,
12014 				 rack->r_ctl.last_collapse_point, __LINE__);
12015 		if (rsm->r_in_tmap) {
12016 			TAILQ_INSERT_AFTER(&rack->r_ctl.rc_tmap, rsm, nrsm, r_tnext);
12017 			nrsm->r_in_tmap = 1;
12018 		}
12019 		/*
12020 		 * Set in the new RSM as the
12021 		 * collapsed starting point
12022 		 */
12023 		rsm = nrsm;
12024 	}
12025 
12026 no_split:
12027 	TQHASH_FOREACH_FROM(nrsm, rack->r_ctl.tqh, rsm)  {
12028 		cnt++;
12029 		nrsm->r_flags |= RACK_RWND_COLLAPSED;
12030 		rack_log_collapse(rack, nrsm->r_start, nrsm->r_end, 0, line, 4, nrsm->r_flags, nrsm);
12031 		cnt++;
12032 	}
12033 	if (cnt) {
12034 		counter_u64_add(rack_collapsed_win, 1);
12035 	}
12036 	rack_log_collapse(rack, cnt, split, ctf_outstanding(rack->rc_tp), line, 0, 0, NULL);
12037 }
12038 
12039 static void
12040 rack_handle_delayed_ack(struct tcpcb *tp, struct tcp_rack *rack,
12041 			int32_t tlen, int32_t tfo_syn)
12042 {
12043 	if (DELAY_ACK(tp, tlen) || tfo_syn) {
12044 		rack_timer_cancel(tp, rack,
12045 				  rack->r_ctl.rc_rcvtime, __LINE__);
12046 		tp->t_flags |= TF_DELACK;
12047 	} else {
12048 		rack->r_wanted_output = 1;
12049 		tp->t_flags |= TF_ACKNOW;
12050 	}
12051 }
12052 
12053 static void
12054 rack_validate_fo_sendwin_up(struct tcpcb *tp, struct tcp_rack *rack)
12055 {
12056 	/*
12057 	 * If fast output is in progress, lets validate that
12058 	 * the new window did not shrink on us and make it
12059 	 * so fast output should end.
12060 	 */
12061 	if (rack->r_fast_output) {
12062 		uint32_t out;
12063 
12064 		/*
12065 		 * Calculate what we will send if left as is
12066 		 * and compare that to our send window.
12067 		 */
12068 		out = ctf_outstanding(tp);
12069 		if ((out + rack->r_ctl.fsb.left_to_send) > tp->snd_wnd) {
12070 			/* ok we have an issue */
12071 			if (out >= tp->snd_wnd) {
12072 				/* Turn off fast output the window is met or collapsed */
12073 				rack->r_fast_output = 0;
12074 			} else {
12075 				/* we have some room left */
12076 				rack->r_ctl.fsb.left_to_send = tp->snd_wnd - out;
12077 				if (rack->r_ctl.fsb.left_to_send < ctf_fixed_maxseg(tp)) {
12078 					/* If not at least 1 full segment never mind */
12079 					rack->r_fast_output = 0;
12080 				}
12081 			}
12082 		}
12083 	}
12084 }
12085 
12086 /*
12087  * Return value of 1, the TCB is unlocked and most
12088  * likely gone, return value of 0, the TCP is still
12089  * locked.
12090  */
12091 static int
12092 rack_process_data(struct mbuf *m, struct tcphdr *th, struct socket *so,
12093     struct tcpcb *tp, int32_t drop_hdrlen, int32_t tlen,
12094     uint32_t tiwin, int32_t thflags, int32_t nxt_pkt)
12095 {
12096 	/*
12097 	 * Update window information. Don't look at window if no ACK: TAC's
12098 	 * send garbage on first SYN.
12099 	 */
12100 	int32_t nsegs;
12101 	int32_t tfo_syn;
12102 	struct tcp_rack *rack;
12103 
12104 	INP_WLOCK_ASSERT(tptoinpcb(tp));
12105 
12106 	rack = (struct tcp_rack *)tp->t_fb_ptr;
12107 	nsegs = max(1, m->m_pkthdr.lro_nsegs);
12108 	if ((thflags & TH_ACK) &&
12109 	    (SEQ_LT(tp->snd_wl1, th->th_seq) ||
12110 	    (tp->snd_wl1 == th->th_seq && (SEQ_LT(tp->snd_wl2, th->th_ack) ||
12111 	    (tp->snd_wl2 == th->th_ack && tiwin > tp->snd_wnd))))) {
12112 		/* keep track of pure window updates */
12113 		if (tlen == 0 &&
12114 		    tp->snd_wl2 == th->th_ack && tiwin > tp->snd_wnd)
12115 			KMOD_TCPSTAT_INC(tcps_rcvwinupd);
12116 		tp->snd_wnd = tiwin;
12117 		rack_validate_fo_sendwin_up(tp, rack);
12118 		tp->snd_wl1 = th->th_seq;
12119 		tp->snd_wl2 = th->th_ack;
12120 		if (tp->snd_wnd > tp->max_sndwnd)
12121 			tp->max_sndwnd = tp->snd_wnd;
12122 		rack->r_wanted_output = 1;
12123 	} else if (thflags & TH_ACK) {
12124 		if ((tp->snd_wl2 == th->th_ack) && (tiwin < tp->snd_wnd)) {
12125 			tp->snd_wnd = tiwin;
12126 			rack_validate_fo_sendwin_up(tp, rack);
12127 			tp->snd_wl1 = th->th_seq;
12128 			tp->snd_wl2 = th->th_ack;
12129 		}
12130 	}
12131 	if (tp->snd_wnd < ctf_outstanding(tp))
12132 		/* The peer collapsed the window */
12133 		rack_collapsed_window(rack, ctf_outstanding(tp), th->th_ack, __LINE__);
12134 	else if (rack->rc_has_collapsed)
12135 		rack_un_collapse_window(rack, __LINE__);
12136 	if ((rack->r_collapse_point_valid) &&
12137 	    (SEQ_GT(th->th_ack, rack->r_ctl.high_collapse_point)))
12138 		rack->r_collapse_point_valid = 0;
12139 	/* Was persist timer active and now we have window space? */
12140 	if ((rack->rc_in_persist != 0) &&
12141 	    (tp->snd_wnd >= min((rack->r_ctl.rc_high_rwnd/2),
12142 				rack->r_ctl.rc_pace_min_segs))) {
12143 		rack_exit_persist(tp, rack, rack->r_ctl.rc_rcvtime);
12144 		tp->snd_nxt = tp->snd_max;
12145 		/* Make sure we output to start the timer */
12146 		rack->r_wanted_output = 1;
12147 	}
12148 	/* Do we enter persists? */
12149 	if ((rack->rc_in_persist == 0) &&
12150 	    (tp->snd_wnd < min((rack->r_ctl.rc_high_rwnd/2), rack->r_ctl.rc_pace_min_segs)) &&
12151 	    TCPS_HAVEESTABLISHED(tp->t_state) &&
12152 	    ((tp->snd_max == tp->snd_una) || rack->rc_has_collapsed) &&
12153 	    sbavail(&tptosocket(tp)->so_snd) &&
12154 	    (sbavail(&tptosocket(tp)->so_snd) > tp->snd_wnd)) {
12155 		/*
12156 		 * Here the rwnd is less than
12157 		 * the pacing size, we are established,
12158 		 * nothing is outstanding, and there is
12159 		 * data to send. Enter persists.
12160 		 */
12161 		rack_enter_persist(tp, rack, rack->r_ctl.rc_rcvtime, tp->snd_una);
12162 	}
12163 	if (tp->t_flags2 & TF2_DROP_AF_DATA) {
12164 		m_freem(m);
12165 		return (0);
12166 	}
12167 	/*
12168 	 * don't process the URG bit, ignore them drag
12169 	 * along the up.
12170 	 */
12171 	tp->rcv_up = tp->rcv_nxt;
12172 
12173 	/*
12174 	 * Process the segment text, merging it into the TCP sequencing
12175 	 * queue, and arranging for acknowledgment of receipt if necessary.
12176 	 * This process logically involves adjusting tp->rcv_wnd as data is
12177 	 * presented to the user (this happens in tcp_usrreq.c, case
12178 	 * PRU_RCVD).  If a FIN has already been received on this connection
12179 	 * then we just ignore the text.
12180 	 */
12181 	tfo_syn = ((tp->t_state == TCPS_SYN_RECEIVED) &&
12182 	    (tp->t_flags & TF_FASTOPEN));
12183 	if ((tlen || (thflags & TH_FIN) || (tfo_syn && tlen > 0)) &&
12184 	    TCPS_HAVERCVDFIN(tp->t_state) == 0) {
12185 		tcp_seq save_start = th->th_seq;
12186 		tcp_seq save_rnxt  = tp->rcv_nxt;
12187 		int     save_tlen  = tlen;
12188 
12189 		m_adj(m, drop_hdrlen);	/* delayed header drop */
12190 		/*
12191 		 * Insert segment which includes th into TCP reassembly
12192 		 * queue with control block tp.  Set thflags to whether
12193 		 * reassembly now includes a segment with FIN.  This handles
12194 		 * the common case inline (segment is the next to be
12195 		 * received on an established connection, and the queue is
12196 		 * empty), avoiding linkage into and removal from the queue
12197 		 * and repetition of various conversions. Set DELACK for
12198 		 * segments received in order, but ack immediately when
12199 		 * segments are out of order (so fast retransmit can work).
12200 		 */
12201 		if (th->th_seq == tp->rcv_nxt &&
12202 		    SEGQ_EMPTY(tp) &&
12203 		    (TCPS_HAVEESTABLISHED(tp->t_state) ||
12204 		    tfo_syn)) {
12205 #ifdef NETFLIX_SB_LIMITS
12206 			u_int mcnt, appended;
12207 
12208 			if (so->so_rcv.sb_shlim) {
12209 				mcnt = m_memcnt(m);
12210 				appended = 0;
12211 				if (counter_fo_get(so->so_rcv.sb_shlim, mcnt,
12212 				    CFO_NOSLEEP, NULL) == false) {
12213 					counter_u64_add(tcp_sb_shlim_fails, 1);
12214 					m_freem(m);
12215 					return (0);
12216 				}
12217 			}
12218 #endif
12219 			rack_handle_delayed_ack(tp, rack, tlen, tfo_syn);
12220 			tp->rcv_nxt += tlen;
12221 			if (tlen &&
12222 			    ((tp->t_flags2 & TF2_FBYTES_COMPLETE) == 0) &&
12223 			    (tp->t_fbyte_in == 0)) {
12224 				tp->t_fbyte_in = ticks;
12225 				if (tp->t_fbyte_in == 0)
12226 					tp->t_fbyte_in = 1;
12227 				if (tp->t_fbyte_out && tp->t_fbyte_in)
12228 					tp->t_flags2 |= TF2_FBYTES_COMPLETE;
12229 			}
12230 			thflags = tcp_get_flags(th) & TH_FIN;
12231 			KMOD_TCPSTAT_ADD(tcps_rcvpack, nsegs);
12232 			KMOD_TCPSTAT_ADD(tcps_rcvbyte, tlen);
12233 			SOCK_RECVBUF_LOCK(so);
12234 			if (so->so_rcv.sb_state & SBS_CANTRCVMORE) {
12235 				m_freem(m);
12236 			} else {
12237 				int32_t newsize;
12238 
12239 				if (tlen > 0) {
12240 					newsize = tcp_autorcvbuf(m, th, so, tp, tlen);
12241 					if (newsize)
12242 						if (!sbreserve_locked(so, SO_RCV, newsize, NULL))
12243 							so->so_rcv.sb_flags &= ~SB_AUTOSIZE;
12244 				}
12245 #ifdef NETFLIX_SB_LIMITS
12246 				appended =
12247 #endif
12248 					sbappendstream_locked(&so->so_rcv, m, 0);
12249 			}
12250 			rack_log_wakeup(tp,rack, &so->so_rcv, tlen, 1);
12251 			/* NB: sorwakeup_locked() does an implicit unlock. */
12252 			sorwakeup_locked(so);
12253 #ifdef NETFLIX_SB_LIMITS
12254 			if (so->so_rcv.sb_shlim && appended != mcnt)
12255 				counter_fo_release(so->so_rcv.sb_shlim,
12256 				    mcnt - appended);
12257 #endif
12258 		} else {
12259 			/*
12260 			 * XXX: Due to the header drop above "th" is
12261 			 * theoretically invalid by now.  Fortunately
12262 			 * m_adj() doesn't actually frees any mbufs when
12263 			 * trimming from the head.
12264 			 */
12265 			tcp_seq temp = save_start;
12266 
12267 			thflags = tcp_reass(tp, th, &temp, &tlen, m);
12268 			tp->t_flags |= TF_ACKNOW;
12269 			if (tp->t_flags & TF_WAKESOR) {
12270 				tp->t_flags &= ~TF_WAKESOR;
12271 				/* NB: sorwakeup_locked() does an implicit unlock. */
12272 				sorwakeup_locked(so);
12273 			}
12274 		}
12275 		if ((tp->t_flags & TF_SACK_PERMIT) &&
12276 		    (save_tlen > 0) &&
12277 		    TCPS_HAVEESTABLISHED(tp->t_state)) {
12278 			if ((tlen == 0) && (SEQ_LT(save_start, save_rnxt))) {
12279 				/*
12280 				 * DSACK actually handled in the fastpath
12281 				 * above.
12282 				 */
12283 				tcp_update_sack_list(tp, save_start,
12284 				    save_start + save_tlen);
12285 			} else if ((tlen > 0) && SEQ_GT(tp->rcv_nxt, save_rnxt)) {
12286 				if ((tp->rcv_numsacks >= 1) &&
12287 				    (tp->sackblks[0].end == save_start)) {
12288 					/*
12289 					 * Partial overlap, recorded at todrop
12290 					 * above.
12291 					 */
12292 					tcp_update_sack_list(tp,
12293 					    tp->sackblks[0].start,
12294 					    tp->sackblks[0].end);
12295 				} else {
12296 					tcp_update_dsack_list(tp, save_start,
12297 					    save_start + save_tlen);
12298 				}
12299 			} else if (tlen >= save_tlen) {
12300 				/* Update of sackblks. */
12301 				tcp_update_dsack_list(tp, save_start,
12302 				    save_start + save_tlen);
12303 			} else if (tlen > 0) {
12304 				tcp_update_dsack_list(tp, save_start,
12305 				    save_start + tlen);
12306 			}
12307 		}
12308 	} else {
12309 		m_freem(m);
12310 		thflags &= ~TH_FIN;
12311 	}
12312 
12313 	/*
12314 	 * If FIN is received ACK the FIN and let the user know that the
12315 	 * connection is closing.
12316 	 */
12317 	if (thflags & TH_FIN) {
12318 		if (TCPS_HAVERCVDFIN(tp->t_state) == 0) {
12319 			/* The socket upcall is handled by socantrcvmore. */
12320 			socantrcvmore(so);
12321 			/*
12322 			 * If connection is half-synchronized (ie NEEDSYN
12323 			 * flag on) then delay ACK, so it may be piggybacked
12324 			 * when SYN is sent. Otherwise, since we received a
12325 			 * FIN then no more input can be expected, send ACK
12326 			 * now.
12327 			 */
12328 			if (tp->t_flags & TF_NEEDSYN) {
12329 				rack_timer_cancel(tp, rack,
12330 				    rack->r_ctl.rc_rcvtime, __LINE__);
12331 				tp->t_flags |= TF_DELACK;
12332 			} else {
12333 				tp->t_flags |= TF_ACKNOW;
12334 			}
12335 			tp->rcv_nxt++;
12336 		}
12337 		switch (tp->t_state) {
12338 			/*
12339 			 * In SYN_RECEIVED and ESTABLISHED STATES enter the
12340 			 * CLOSE_WAIT state.
12341 			 */
12342 		case TCPS_SYN_RECEIVED:
12343 			tp->t_starttime = ticks;
12344 			/* FALLTHROUGH */
12345 		case TCPS_ESTABLISHED:
12346 			rack_timer_cancel(tp, rack,
12347 			    rack->r_ctl.rc_rcvtime, __LINE__);
12348 			tcp_state_change(tp, TCPS_CLOSE_WAIT);
12349 			break;
12350 
12351 			/*
12352 			 * If still in FIN_WAIT_1 STATE FIN has not been
12353 			 * acked so enter the CLOSING state.
12354 			 */
12355 		case TCPS_FIN_WAIT_1:
12356 			rack_timer_cancel(tp, rack,
12357 			    rack->r_ctl.rc_rcvtime, __LINE__);
12358 			tcp_state_change(tp, TCPS_CLOSING);
12359 			break;
12360 
12361 			/*
12362 			 * In FIN_WAIT_2 state enter the TIME_WAIT state,
12363 			 * starting the time-wait timer, turning off the
12364 			 * other standard timers.
12365 			 */
12366 		case TCPS_FIN_WAIT_2:
12367 			rack_timer_cancel(tp, rack,
12368 			    rack->r_ctl.rc_rcvtime, __LINE__);
12369 			tcp_twstart(tp);
12370 			return (1);
12371 		}
12372 	}
12373 	/*
12374 	 * Return any desired output.
12375 	 */
12376 	if ((tp->t_flags & TF_ACKNOW) ||
12377 	    (sbavail(&so->so_snd) > (tp->snd_max - tp->snd_una))) {
12378 		rack->r_wanted_output = 1;
12379 	}
12380 	return (0);
12381 }
12382 
12383 /*
12384  * Here nothing is really faster, its just that we
12385  * have broken out the fast-data path also just like
12386  * the fast-ack.
12387  */
12388 static int
12389 rack_do_fastnewdata(struct mbuf *m, struct tcphdr *th, struct socket *so,
12390     struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen,
12391     uint32_t tiwin, int32_t nxt_pkt, uint8_t iptos)
12392 {
12393 	int32_t nsegs;
12394 	int32_t newsize = 0;	/* automatic sockbuf scaling */
12395 	struct tcp_rack *rack;
12396 #ifdef NETFLIX_SB_LIMITS
12397 	u_int mcnt, appended;
12398 #endif
12399 
12400 	/*
12401 	 * If last ACK falls within this segment's sequence numbers, record
12402 	 * the timestamp. NOTE that the test is modified according to the
12403 	 * latest proposal of the tcplw@cray.com list (Braden 1993/04/26).
12404 	 */
12405 	if (__predict_false(th->th_seq != tp->rcv_nxt)) {
12406 		return (0);
12407 	}
12408 	if (tiwin && tiwin != tp->snd_wnd) {
12409 		return (0);
12410 	}
12411 	if (__predict_false((tp->t_flags & (TF_NEEDSYN | TF_NEEDFIN)))) {
12412 		return (0);
12413 	}
12414 	if (__predict_false((to->to_flags & TOF_TS) &&
12415 	    (TSTMP_LT(to->to_tsval, tp->ts_recent)))) {
12416 		return (0);
12417 	}
12418 	if (__predict_false((th->th_ack != tp->snd_una))) {
12419 		return (0);
12420 	}
12421 	if (__predict_false(tlen > sbspace(&so->so_rcv))) {
12422 		return (0);
12423 	}
12424 	if ((to->to_flags & TOF_TS) != 0 &&
12425 	    SEQ_LEQ(th->th_seq, tp->last_ack_sent)) {
12426 		tp->ts_recent_age = tcp_ts_getticks();
12427 		tp->ts_recent = to->to_tsval;
12428 	}
12429 	rack = (struct tcp_rack *)tp->t_fb_ptr;
12430 	/*
12431 	 * This is a pure, in-sequence data packet with nothing on the
12432 	 * reassembly queue and we have enough buffer space to take it.
12433 	 */
12434 	nsegs = max(1, m->m_pkthdr.lro_nsegs);
12435 
12436 #ifdef NETFLIX_SB_LIMITS
12437 	if (so->so_rcv.sb_shlim) {
12438 		mcnt = m_memcnt(m);
12439 		appended = 0;
12440 		if (counter_fo_get(so->so_rcv.sb_shlim, mcnt,
12441 		    CFO_NOSLEEP, NULL) == false) {
12442 			counter_u64_add(tcp_sb_shlim_fails, 1);
12443 			m_freem(m);
12444 			return (1);
12445 		}
12446 	}
12447 #endif
12448 	/* Clean receiver SACK report if present */
12449 	if (tp->rcv_numsacks)
12450 		tcp_clean_sackreport(tp);
12451 	KMOD_TCPSTAT_INC(tcps_preddat);
12452 	tp->rcv_nxt += tlen;
12453 	if (tlen &&
12454 	    ((tp->t_flags2 & TF2_FBYTES_COMPLETE) == 0) &&
12455 	    (tp->t_fbyte_in == 0)) {
12456 		tp->t_fbyte_in = ticks;
12457 		if (tp->t_fbyte_in == 0)
12458 			tp->t_fbyte_in = 1;
12459 		if (tp->t_fbyte_out && tp->t_fbyte_in)
12460 			tp->t_flags2 |= TF2_FBYTES_COMPLETE;
12461 	}
12462 	/*
12463 	 * Pull snd_wl1 up to prevent seq wrap relative to th_seq.
12464 	 */
12465 	tp->snd_wl1 = th->th_seq;
12466 	/*
12467 	 * Pull rcv_up up to prevent seq wrap relative to rcv_nxt.
12468 	 */
12469 	tp->rcv_up = tp->rcv_nxt;
12470 	KMOD_TCPSTAT_ADD(tcps_rcvpack, nsegs);
12471 	KMOD_TCPSTAT_ADD(tcps_rcvbyte, tlen);
12472 	newsize = tcp_autorcvbuf(m, th, so, tp, tlen);
12473 
12474 	/* Add data to socket buffer. */
12475 	SOCK_RECVBUF_LOCK(so);
12476 	if (so->so_rcv.sb_state & SBS_CANTRCVMORE) {
12477 		m_freem(m);
12478 	} else {
12479 		/*
12480 		 * Set new socket buffer size. Give up when limit is
12481 		 * reached.
12482 		 */
12483 		if (newsize)
12484 			if (!sbreserve_locked(so, SO_RCV, newsize, NULL))
12485 				so->so_rcv.sb_flags &= ~SB_AUTOSIZE;
12486 		m_adj(m, drop_hdrlen);	/* delayed header drop */
12487 #ifdef NETFLIX_SB_LIMITS
12488 		appended =
12489 #endif
12490 			sbappendstream_locked(&so->so_rcv, m, 0);
12491 		ctf_calc_rwin(so, tp);
12492 	}
12493 	rack_log_wakeup(tp,rack, &so->so_rcv, tlen, 1);
12494 	/* NB: sorwakeup_locked() does an implicit unlock. */
12495 	sorwakeup_locked(so);
12496 #ifdef NETFLIX_SB_LIMITS
12497 	if (so->so_rcv.sb_shlim && mcnt != appended)
12498 		counter_fo_release(so->so_rcv.sb_shlim, mcnt - appended);
12499 #endif
12500 	rack_handle_delayed_ack(tp, rack, tlen, 0);
12501 	if (tp->snd_una == tp->snd_max)
12502 		sack_filter_clear(&rack->r_ctl.rack_sf, tp->snd_una);
12503 	return (1);
12504 }
12505 
12506 /*
12507  * This subfunction is used to try to highly optimize the
12508  * fast path. We again allow window updates that are
12509  * in sequence to remain in the fast-path. We also add
12510  * in the __predict's to attempt to help the compiler.
12511  * Note that if we return a 0, then we can *not* process
12512  * it and the caller should push the packet into the
12513  * slow-path.
12514  */
12515 static int
12516 rack_fastack(struct mbuf *m, struct tcphdr *th, struct socket *so,
12517     struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen,
12518     uint32_t tiwin, int32_t nxt_pkt, uint32_t cts)
12519 {
12520 	int32_t acked;
12521 	int32_t nsegs;
12522 	int32_t under_pacing = 0;
12523 	struct tcp_rack *rack;
12524 
12525 	if (__predict_false(SEQ_LEQ(th->th_ack, tp->snd_una))) {
12526 		/* Old ack, behind (or duplicate to) the last one rcv'd */
12527 		return (0);
12528 	}
12529 	if (__predict_false(SEQ_GT(th->th_ack, tp->snd_max))) {
12530 		/* Above what we have sent? */
12531 		return (0);
12532 	}
12533 	if (__predict_false(tiwin == 0)) {
12534 		/* zero window */
12535 		return (0);
12536 	}
12537 	if (__predict_false(tp->t_flags & (TF_NEEDSYN | TF_NEEDFIN))) {
12538 		/* We need a SYN or a FIN, unlikely.. */
12539 		return (0);
12540 	}
12541 	if ((to->to_flags & TOF_TS) && __predict_false(TSTMP_LT(to->to_tsval, tp->ts_recent))) {
12542 		/* Timestamp is behind .. old ack with seq wrap? */
12543 		return (0);
12544 	}
12545 	if (__predict_false(IN_RECOVERY(tp->t_flags))) {
12546 		/* Still recovering */
12547 		return (0);
12548 	}
12549 	rack = (struct tcp_rack *)tp->t_fb_ptr;
12550 	if (rack->r_ctl.rc_sacked) {
12551 		/* We have sack holes on our scoreboard */
12552 		return (0);
12553 	}
12554 	/* Ok if we reach here, we can process a fast-ack */
12555 	if (rack->gp_ready &&
12556 	    (rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT)) {
12557 		under_pacing = 1;
12558 	}
12559 	nsegs = max(1, m->m_pkthdr.lro_nsegs);
12560 	rack_log_ack(tp, to, th, 0, 0, NULL, NULL);
12561 	/* Did the window get updated? */
12562 	if (tiwin != tp->snd_wnd) {
12563 		tp->snd_wnd = tiwin;
12564 		rack_validate_fo_sendwin_up(tp, rack);
12565 		tp->snd_wl1 = th->th_seq;
12566 		if (tp->snd_wnd > tp->max_sndwnd)
12567 			tp->max_sndwnd = tp->snd_wnd;
12568 	}
12569 	/* Do we exit persists? */
12570 	if ((rack->rc_in_persist != 0) &&
12571 	    (tp->snd_wnd >= min((rack->r_ctl.rc_high_rwnd/2),
12572 			       rack->r_ctl.rc_pace_min_segs))) {
12573 		rack_exit_persist(tp, rack, cts);
12574 	}
12575 	/* Do we enter persists? */
12576 	if ((rack->rc_in_persist == 0) &&
12577 	    (tp->snd_wnd < min((rack->r_ctl.rc_high_rwnd/2), rack->r_ctl.rc_pace_min_segs)) &&
12578 	    TCPS_HAVEESTABLISHED(tp->t_state) &&
12579 	    ((tp->snd_max == tp->snd_una) || rack->rc_has_collapsed) &&
12580 	    sbavail(&tptosocket(tp)->so_snd) &&
12581 	    (sbavail(&tptosocket(tp)->so_snd) > tp->snd_wnd)) {
12582 		/*
12583 		 * Here the rwnd is less than
12584 		 * the pacing size, we are established,
12585 		 * nothing is outstanding, and there is
12586 		 * data to send. Enter persists.
12587 		 */
12588 		rack_enter_persist(tp, rack, rack->r_ctl.rc_rcvtime, th->th_ack);
12589 	}
12590 	/*
12591 	 * If last ACK falls within this segment's sequence numbers, record
12592 	 * the timestamp. NOTE that the test is modified according to the
12593 	 * latest proposal of the tcplw@cray.com list (Braden 1993/04/26).
12594 	 */
12595 	if ((to->to_flags & TOF_TS) != 0 &&
12596 	    SEQ_LEQ(th->th_seq, tp->last_ack_sent)) {
12597 		tp->ts_recent_age = tcp_ts_getticks();
12598 		tp->ts_recent = to->to_tsval;
12599 	}
12600 	/*
12601 	 * This is a pure ack for outstanding data.
12602 	 */
12603 	KMOD_TCPSTAT_INC(tcps_predack);
12604 
12605 	/*
12606 	 * "bad retransmit" recovery.
12607 	 */
12608 	if ((tp->t_flags & TF_PREVVALID) &&
12609 	    ((tp->t_flags & TF_RCVD_TSTMP) == 0)) {
12610 		tp->t_flags &= ~TF_PREVVALID;
12611 		if (tp->t_rxtshift == 1 &&
12612 		    (int)(ticks - tp->t_badrxtwin) < 0)
12613 			rack_cong_signal(tp, CC_RTO_ERR, th->th_ack, __LINE__);
12614 	}
12615 	/*
12616 	 * Recalculate the transmit timer / rtt.
12617 	 *
12618 	 * Some boxes send broken timestamp replies during the SYN+ACK
12619 	 * phase, ignore timestamps of 0 or we could calculate a huge RTT
12620 	 * and blow up the retransmit timer.
12621 	 */
12622 	acked = BYTES_THIS_ACK(tp, th);
12623 
12624 #ifdef TCP_HHOOK
12625 	/* Run HHOOK_TCP_ESTABLISHED_IN helper hooks. */
12626 	hhook_run_tcp_est_in(tp, th, to);
12627 #endif
12628 	KMOD_TCPSTAT_ADD(tcps_rcvackpack, nsegs);
12629 	KMOD_TCPSTAT_ADD(tcps_rcvackbyte, acked);
12630 	if (acked) {
12631 		struct mbuf *mfree;
12632 
12633 		rack_ack_received(tp, rack, th->th_ack, nsegs, CC_ACK, 0);
12634 		SOCK_SENDBUF_LOCK(so);
12635 		mfree = sbcut_locked(&so->so_snd, acked);
12636 		tp->snd_una = th->th_ack;
12637 		/* Note we want to hold the sb lock through the sendmap adjust */
12638 		rack_adjust_sendmap_head(rack, &so->so_snd);
12639 		/* Wake up the socket if we have room to write more */
12640 		rack_log_wakeup(tp,rack, &so->so_snd, acked, 2);
12641 		sowwakeup_locked(so);
12642 		m_freem(mfree);
12643 		tp->t_rxtshift = 0;
12644 		RACK_TCPT_RANGESET(tp->t_rxtcur, RACK_REXMTVAL(tp),
12645 			      rack_rto_min, rack_rto_max, rack->r_ctl.timer_slop);
12646 		rack->rc_tlp_in_progress = 0;
12647 		rack->r_ctl.rc_tlp_cnt_out = 0;
12648 		/*
12649 		 * If it is the RXT timer we want to
12650 		 * stop it, so we can restart a TLP.
12651 		 */
12652 		if (rack->r_ctl.rc_hpts_flags & PACE_TMR_RXT)
12653 			rack_timer_cancel(tp, rack, rack->r_ctl.rc_rcvtime, __LINE__);
12654 
12655 #ifdef TCP_REQUEST_TRK
12656 		rack_req_check_for_comp(rack, th->th_ack);
12657 #endif
12658 	}
12659 	/*
12660 	 * Let the congestion control algorithm update congestion control
12661 	 * related information. This typically means increasing the
12662 	 * congestion window.
12663 	 */
12664 	if (tp->snd_wnd < ctf_outstanding(tp)) {
12665 		/* The peer collapsed the window */
12666 		rack_collapsed_window(rack, ctf_outstanding(tp), th->th_ack, __LINE__);
12667 	} else if (rack->rc_has_collapsed)
12668 		rack_un_collapse_window(rack, __LINE__);
12669 	if ((rack->r_collapse_point_valid) &&
12670 	    (SEQ_GT(tp->snd_una, rack->r_ctl.high_collapse_point)))
12671 		rack->r_collapse_point_valid = 0;
12672 	/*
12673 	 * Pull snd_wl2 up to prevent seq wrap relative to th_ack.
12674 	 */
12675 	tp->snd_wl2 = th->th_ack;
12676 	tp->t_dupacks = 0;
12677 	m_freem(m);
12678 	/* ND6_HINT(tp);	 *//* Some progress has been made. */
12679 
12680 	/*
12681 	 * If all outstanding data are acked, stop retransmit timer,
12682 	 * otherwise restart timer using current (possibly backed-off)
12683 	 * value. If process is waiting for space, wakeup/selwakeup/signal.
12684 	 * If data are ready to send, let tcp_output decide between more
12685 	 * output or persist.
12686 	 */
12687 	if (under_pacing &&
12688 	    (rack->use_fixed_rate == 0) &&
12689 	    (rack->in_probe_rtt == 0) &&
12690 	    rack->rc_gp_dyn_mul &&
12691 	    rack->rc_always_pace) {
12692 		/* Check if we are dragging bottom */
12693 		rack_check_bottom_drag(tp, rack, so);
12694 	}
12695 	if (tp->snd_una == tp->snd_max) {
12696 		tp->t_flags &= ~TF_PREVVALID;
12697 		rack->r_ctl.retran_during_recovery = 0;
12698 		rack->rc_suspicious = 0;
12699 		rack->r_ctl.dsack_byte_cnt = 0;
12700 		rack->r_ctl.rc_went_idle_time = tcp_get_usecs(NULL);
12701 		if (rack->r_ctl.rc_went_idle_time == 0)
12702 			rack->r_ctl.rc_went_idle_time = 1;
12703 		rack_log_progress_event(rack, tp, 0, PROGRESS_CLEAR, __LINE__);
12704 		if (sbavail(&tptosocket(tp)->so_snd) == 0)
12705 			tp->t_acktime = 0;
12706 		rack_timer_cancel(tp, rack, rack->r_ctl.rc_rcvtime, __LINE__);
12707 	}
12708 	if (acked && rack->r_fast_output)
12709 		rack_gain_for_fastoutput(rack, tp, so, (uint32_t)acked);
12710 	if (sbavail(&so->so_snd)) {
12711 		rack->r_wanted_output = 1;
12712 	}
12713 	return (1);
12714 }
12715 
12716 /*
12717  * Return value of 1, the TCB is unlocked and most
12718  * likely gone, return value of 0, the TCP is still
12719  * locked.
12720  */
12721 static int
12722 rack_do_syn_sent(struct mbuf *m, struct tcphdr *th, struct socket *so,
12723     struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen,
12724     uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos)
12725 {
12726 	int32_t ret_val = 0;
12727 	int32_t orig_tlen = tlen;
12728 	int32_t todrop;
12729 	int32_t ourfinisacked = 0;
12730 	struct tcp_rack *rack;
12731 
12732 	INP_WLOCK_ASSERT(tptoinpcb(tp));
12733 
12734 	ctf_calc_rwin(so, tp);
12735 	/*
12736 	 * If the state is SYN_SENT: if seg contains an ACK, but not for our
12737 	 * SYN, drop the input. if seg contains a RST, then drop the
12738 	 * connection. if seg does not contain SYN, then drop it. Otherwise
12739 	 * this is an acceptable SYN segment initialize tp->rcv_nxt and
12740 	 * tp->irs if seg contains ack then advance tp->snd_una if seg
12741 	 * contains an ECE and ECN support is enabled, the stream is ECN
12742 	 * capable. if SYN has been acked change to ESTABLISHED else
12743 	 * SYN_RCVD state arrange for segment to be acked (eventually)
12744 	 * continue processing rest of data/controls.
12745 	 */
12746 	if ((thflags & TH_ACK) &&
12747 	    (SEQ_LEQ(th->th_ack, tp->iss) ||
12748 	    SEQ_GT(th->th_ack, tp->snd_max))) {
12749 		tcp_log_end_status(tp, TCP_EI_STATUS_RST_IN_FRONT);
12750 		ctf_do_dropwithreset(m, tp, th, tlen);
12751 		return (1);
12752 	}
12753 	if ((thflags & (TH_ACK | TH_RST)) == (TH_ACK | TH_RST)) {
12754 		TCP_PROBE5(connect__refused, NULL, tp,
12755 		    mtod(m, const char *), tp, th);
12756 		tp = tcp_drop(tp, ECONNREFUSED);
12757 		ctf_do_drop(m, tp);
12758 		return (1);
12759 	}
12760 	if (thflags & TH_RST) {
12761 		ctf_do_drop(m, tp);
12762 		return (1);
12763 	}
12764 	if (!(thflags & TH_SYN)) {
12765 		ctf_do_drop(m, tp);
12766 		return (1);
12767 	}
12768 	tp->irs = th->th_seq;
12769 	tcp_rcvseqinit(tp);
12770 	rack = (struct tcp_rack *)tp->t_fb_ptr;
12771 	if (thflags & TH_ACK) {
12772 		int tfo_partial = 0;
12773 
12774 		KMOD_TCPSTAT_INC(tcps_connects);
12775 		soisconnected(so);
12776 #ifdef MAC
12777 		mac_socketpeer_set_from_mbuf(m, so);
12778 #endif
12779 		/* Do window scaling on this connection? */
12780 		if ((tp->t_flags & (TF_RCVD_SCALE | TF_REQ_SCALE)) ==
12781 		    (TF_RCVD_SCALE | TF_REQ_SCALE)) {
12782 			tp->rcv_scale = tp->request_r_scale;
12783 		}
12784 		tp->rcv_adv += min(tp->rcv_wnd,
12785 		    TCP_MAXWIN << tp->rcv_scale);
12786 		/*
12787 		 * If not all the data that was sent in the TFO SYN
12788 		 * has been acked, resend the remainder right away.
12789 		 */
12790 		if ((tp->t_flags & TF_FASTOPEN) &&
12791 		    (tp->snd_una != tp->snd_max)) {
12792 			/* Was it a partial ack? */
12793 			if (SEQ_LT(th->th_ack, tp->snd_max))
12794 				tfo_partial = 1;
12795 		}
12796 		/*
12797 		 * If there's data, delay ACK; if there's also a FIN ACKNOW
12798 		 * will be turned on later.
12799 		 */
12800 		if (DELAY_ACK(tp, tlen) && tlen != 0 && !tfo_partial) {
12801 			rack_timer_cancel(tp, rack,
12802 					  rack->r_ctl.rc_rcvtime, __LINE__);
12803 			tp->t_flags |= TF_DELACK;
12804 		} else {
12805 			rack->r_wanted_output = 1;
12806 			tp->t_flags |= TF_ACKNOW;
12807 		}
12808 
12809 		tcp_ecn_input_syn_sent(tp, thflags, iptos);
12810 
12811 		if (SEQ_GT(th->th_ack, tp->snd_una)) {
12812 			/*
12813 			 * We advance snd_una for the
12814 			 * fast open case. If th_ack is
12815 			 * acknowledging data beyond
12816 			 * snd_una we can't just call
12817 			 * ack-processing since the
12818 			 * data stream in our send-map
12819 			 * will start at snd_una + 1 (one
12820 			 * beyond the SYN). If its just
12821 			 * equal we don't need to do that
12822 			 * and there is no send_map.
12823 			 */
12824 			tp->snd_una++;
12825 			if (tfo_partial && (SEQ_GT(tp->snd_max, tp->snd_una))) {
12826 				/*
12827 				 * We sent a SYN with data, and thus have a
12828 				 * sendmap entry with a SYN set. Lets find it
12829 				 * and take off the send bit and the byte and
12830 				 * set it up to be what we send (send it next).
12831 				 */
12832 				struct rack_sendmap *rsm;
12833 
12834 				rsm = tqhash_min(rack->r_ctl.tqh);
12835 				if (rsm) {
12836 					if (rsm->r_flags & RACK_HAS_SYN) {
12837 						rsm->r_flags &= ~RACK_HAS_SYN;
12838 						rsm->r_start++;
12839 					}
12840 					rack->r_ctl.rc_resend = rsm;
12841 				}
12842 			}
12843 		}
12844 		/*
12845 		 * Received <SYN,ACK> in SYN_SENT[*] state. Transitions:
12846 		 * SYN_SENT  --> ESTABLISHED SYN_SENT* --> FIN_WAIT_1
12847 		 */
12848 		tp->t_starttime = ticks;
12849 		if (tp->t_flags & TF_NEEDFIN) {
12850 			tcp_state_change(tp, TCPS_FIN_WAIT_1);
12851 			tp->t_flags &= ~TF_NEEDFIN;
12852 			thflags &= ~TH_SYN;
12853 		} else {
12854 			tcp_state_change(tp, TCPS_ESTABLISHED);
12855 			TCP_PROBE5(connect__established, NULL, tp,
12856 			    mtod(m, const char *), tp, th);
12857 			rack_cc_conn_init(tp);
12858 		}
12859 	} else {
12860 		/*
12861 		 * Received initial SYN in SYN-SENT[*] state => simultaneous
12862 		 * open.  If segment contains CC option and there is a
12863 		 * cached CC, apply TAO test. If it succeeds, connection is *
12864 		 * half-synchronized. Otherwise, do 3-way handshake:
12865 		 * SYN-SENT -> SYN-RECEIVED SYN-SENT* -> SYN-RECEIVED* If
12866 		 * there was no CC option, clear cached CC value.
12867 		 */
12868 		tp->t_flags |= (TF_ACKNOW | TF_NEEDSYN | TF_SONOTCONN);
12869 		tcp_state_change(tp, TCPS_SYN_RECEIVED);
12870 	}
12871 	/*
12872 	 * Advance th->th_seq to correspond to first data byte. If data,
12873 	 * trim to stay within window, dropping FIN if necessary.
12874 	 */
12875 	th->th_seq++;
12876 	if (tlen > tp->rcv_wnd) {
12877 		todrop = tlen - tp->rcv_wnd;
12878 		m_adj(m, -todrop);
12879 		tlen = tp->rcv_wnd;
12880 		thflags &= ~TH_FIN;
12881 		KMOD_TCPSTAT_INC(tcps_rcvpackafterwin);
12882 		KMOD_TCPSTAT_ADD(tcps_rcvbyteafterwin, todrop);
12883 	}
12884 	tp->snd_wl1 = th->th_seq - 1;
12885 	tp->rcv_up = th->th_seq;
12886 	/*
12887 	 * Client side of transaction: already sent SYN and data. If the
12888 	 * remote host used T/TCP to validate the SYN, our data will be
12889 	 * ACK'd; if so, enter normal data segment processing in the middle
12890 	 * of step 5, ack processing. Otherwise, goto step 6.
12891 	 */
12892 	if (thflags & TH_ACK) {
12893 		/* For syn-sent we need to possibly update the rtt */
12894 		if ((to->to_flags & TOF_TS) != 0 && to->to_tsecr) {
12895 			uint32_t t, mcts;
12896 
12897 			mcts = tcp_ts_getticks();
12898 			t = (mcts - to->to_tsecr) * HPTS_USEC_IN_MSEC;
12899 			if (!tp->t_rttlow || tp->t_rttlow > t)
12900 				tp->t_rttlow = t;
12901 			rack_log_rtt_sample_calc(rack, t, (to->to_tsecr * 1000), (mcts * 1000), 4);
12902 			tcp_rack_xmit_timer(rack, t + 1, 1, t, 0, NULL, 2);
12903 			tcp_rack_xmit_timer_commit(rack, tp);
12904 		}
12905 		if (rack_process_ack(m, th, so, tp, to, tiwin, tlen, &ourfinisacked, thflags, &ret_val, orig_tlen))
12906 			return (ret_val);
12907 		/* We may have changed to FIN_WAIT_1 above */
12908 		if (tp->t_state == TCPS_FIN_WAIT_1) {
12909 			/*
12910 			 * In FIN_WAIT_1 STATE in addition to the processing
12911 			 * for the ESTABLISHED state if our FIN is now
12912 			 * acknowledged then enter FIN_WAIT_2.
12913 			 */
12914 			if (ourfinisacked) {
12915 				/*
12916 				 * If we can't receive any more data, then
12917 				 * closing user can proceed. Starting the
12918 				 * timer is contrary to the specification,
12919 				 * but if we don't get a FIN we'll hang
12920 				 * forever.
12921 				 *
12922 				 * XXXjl: we should release the tp also, and
12923 				 * use a compressed state.
12924 				 */
12925 				if (so->so_rcv.sb_state & SBS_CANTRCVMORE) {
12926 					soisdisconnected(so);
12927 					tcp_timer_activate(tp, TT_2MSL,
12928 					    (tcp_fast_finwait2_recycle ?
12929 					    tcp_finwait2_timeout :
12930 					    TP_MAXIDLE(tp)));
12931 				}
12932 				tcp_state_change(tp, TCPS_FIN_WAIT_2);
12933 			}
12934 		}
12935 	}
12936 	return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
12937 	   tiwin, thflags, nxt_pkt));
12938 }
12939 
12940 /*
12941  * Return value of 1, the TCB is unlocked and most
12942  * likely gone, return value of 0, the TCP is still
12943  * locked.
12944  */
12945 static int
12946 rack_do_syn_recv(struct mbuf *m, struct tcphdr *th, struct socket *so,
12947     struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen,
12948     uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos)
12949 {
12950 	struct tcp_rack *rack;
12951 	int32_t orig_tlen = tlen;
12952 	int32_t ret_val = 0;
12953 	int32_t ourfinisacked = 0;
12954 
12955 	rack = (struct tcp_rack *)tp->t_fb_ptr;
12956 	ctf_calc_rwin(so, tp);
12957 	if ((thflags & TH_RST) ||
12958 	    (tp->t_fin_is_rst && (thflags & TH_FIN)))
12959 		return (ctf_process_rst(m, th, so, tp));
12960 	if ((thflags & TH_ACK) &&
12961 	    (SEQ_LEQ(th->th_ack, tp->snd_una) ||
12962 	    SEQ_GT(th->th_ack, tp->snd_max))) {
12963 		tcp_log_end_status(tp, TCP_EI_STATUS_RST_IN_FRONT);
12964 		ctf_do_dropwithreset(m, tp, th, tlen);
12965 		return (1);
12966 	}
12967 	if (tp->t_flags & TF_FASTOPEN) {
12968 		/*
12969 		 * When a TFO connection is in SYN_RECEIVED, the
12970 		 * only valid packets are the initial SYN, a
12971 		 * retransmit/copy of the initial SYN (possibly with
12972 		 * a subset of the original data), a valid ACK, a
12973 		 * FIN, or a RST.
12974 		 */
12975 		if ((thflags & (TH_SYN | TH_ACK)) == (TH_SYN | TH_ACK)) {
12976 			tcp_log_end_status(tp, TCP_EI_STATUS_RST_IN_FRONT);
12977 			ctf_do_dropwithreset(m, tp, th, tlen);
12978 			return (1);
12979 		} else if (thflags & TH_SYN) {
12980 			/* non-initial SYN is ignored */
12981 			if ((rack->r_ctl.rc_hpts_flags & PACE_TMR_RXT) ||
12982 			    (rack->r_ctl.rc_hpts_flags & PACE_TMR_TLP) ||
12983 			    (rack->r_ctl.rc_hpts_flags & PACE_TMR_RACK)) {
12984 				ctf_do_drop(m, NULL);
12985 				return (0);
12986 			}
12987 		} else if (!(thflags & (TH_ACK | TH_FIN | TH_RST))) {
12988 			ctf_do_drop(m, NULL);
12989 			return (0);
12990 		}
12991 	}
12992 
12993 	/*
12994 	 * RFC 1323 PAWS: If we have a timestamp reply on this segment and
12995 	 * it's less than ts_recent, drop it.
12996 	 */
12997 	if ((to->to_flags & TOF_TS) != 0 && tp->ts_recent &&
12998 	    TSTMP_LT(to->to_tsval, tp->ts_recent)) {
12999 		if (ctf_ts_check(m, th, tp, tlen, thflags, &ret_val))
13000 			return (ret_val);
13001 	}
13002 	/*
13003 	 * In the SYN-RECEIVED state, validate that the packet belongs to
13004 	 * this connection before trimming the data to fit the receive
13005 	 * window.  Check the sequence number versus IRS since we know the
13006 	 * sequence numbers haven't wrapped.  This is a partial fix for the
13007 	 * "LAND" DoS attack.
13008 	 */
13009 	if (SEQ_LT(th->th_seq, tp->irs)) {
13010 		tcp_log_end_status(tp, TCP_EI_STATUS_RST_IN_FRONT);
13011 		ctf_do_dropwithreset(m, tp, th, tlen);
13012 		return (1);
13013 	}
13014 	if (ctf_drop_checks(to, m, th, tp, &tlen, &thflags, &drop_hdrlen, &ret_val)) {
13015 		return (ret_val);
13016 	}
13017 	/*
13018 	 * If last ACK falls within this segment's sequence numbers, record
13019 	 * its timestamp. NOTE: 1) That the test incorporates suggestions
13020 	 * from the latest proposal of the tcplw@cray.com list (Braden
13021 	 * 1993/04/26). 2) That updating only on newer timestamps interferes
13022 	 * with our earlier PAWS tests, so this check should be solely
13023 	 * predicated on the sequence space of this segment. 3) That we
13024 	 * modify the segment boundary check to be Last.ACK.Sent <= SEG.SEQ
13025 	 * + SEG.Len  instead of RFC1323's Last.ACK.Sent < SEG.SEQ +
13026 	 * SEG.Len, This modified check allows us to overcome RFC1323's
13027 	 * limitations as described in Stevens TCP/IP Illustrated Vol. 2
13028 	 * p.869. In such cases, we can still calculate the RTT correctly
13029 	 * when RCV.NXT == Last.ACK.Sent.
13030 	 */
13031 	if ((to->to_flags & TOF_TS) != 0 &&
13032 	    SEQ_LEQ(th->th_seq, tp->last_ack_sent) &&
13033 	    SEQ_LEQ(tp->last_ack_sent, th->th_seq + tlen +
13034 	    ((thflags & (TH_SYN | TH_FIN)) != 0))) {
13035 		tp->ts_recent_age = tcp_ts_getticks();
13036 		tp->ts_recent = to->to_tsval;
13037 	}
13038 	tp->snd_wnd = tiwin;
13039 	rack_validate_fo_sendwin_up(tp, rack);
13040 	/*
13041 	 * If the ACK bit is off:  if in SYN-RECEIVED state or SENDSYN flag
13042 	 * is on (half-synchronized state), then queue data for later
13043 	 * processing; else drop segment and return.
13044 	 */
13045 	if ((thflags & TH_ACK) == 0) {
13046 		if (tp->t_flags & TF_FASTOPEN) {
13047 			rack_cc_conn_init(tp);
13048 		}
13049 		return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
13050 		    tiwin, thflags, nxt_pkt));
13051 	}
13052 	KMOD_TCPSTAT_INC(tcps_connects);
13053 	if (tp->t_flags & TF_SONOTCONN) {
13054 		tp->t_flags &= ~TF_SONOTCONN;
13055 		soisconnected(so);
13056 	}
13057 	/* Do window scaling? */
13058 	if ((tp->t_flags & (TF_RCVD_SCALE | TF_REQ_SCALE)) ==
13059 	    (TF_RCVD_SCALE | TF_REQ_SCALE)) {
13060 		tp->rcv_scale = tp->request_r_scale;
13061 	}
13062 	/*
13063 	 * Make transitions: SYN-RECEIVED  -> ESTABLISHED SYN-RECEIVED* ->
13064 	 * FIN-WAIT-1
13065 	 */
13066 	tp->t_starttime = ticks;
13067 	if ((tp->t_flags & TF_FASTOPEN) && tp->t_tfo_pending) {
13068 		tcp_fastopen_decrement_counter(tp->t_tfo_pending);
13069 		tp->t_tfo_pending = NULL;
13070 	}
13071 	if (tp->t_flags & TF_NEEDFIN) {
13072 		tcp_state_change(tp, TCPS_FIN_WAIT_1);
13073 		tp->t_flags &= ~TF_NEEDFIN;
13074 	} else {
13075 		tcp_state_change(tp, TCPS_ESTABLISHED);
13076 		TCP_PROBE5(accept__established, NULL, tp,
13077 		    mtod(m, const char *), tp, th);
13078 		/*
13079 		 * TFO connections call cc_conn_init() during SYN
13080 		 * processing.  Calling it again here for such connections
13081 		 * is not harmless as it would undo the snd_cwnd reduction
13082 		 * that occurs when a TFO SYN|ACK is retransmitted.
13083 		 */
13084 		if (!(tp->t_flags & TF_FASTOPEN))
13085 			rack_cc_conn_init(tp);
13086 	}
13087 	/*
13088 	 * Account for the ACK of our SYN prior to
13089 	 * regular ACK processing below, except for
13090 	 * simultaneous SYN, which is handled later.
13091 	 */
13092 	if (SEQ_GT(th->th_ack, tp->snd_una) && !(tp->t_flags & TF_NEEDSYN))
13093 		tp->snd_una++;
13094 	/*
13095 	 * If segment contains data or ACK, will call tcp_reass() later; if
13096 	 * not, do so now to pass queued data to user.
13097 	 */
13098 	if (tlen == 0 && (thflags & TH_FIN) == 0) {
13099 		(void) tcp_reass(tp, (struct tcphdr *)0, NULL, 0,
13100 		    (struct mbuf *)0);
13101 		if (tp->t_flags & TF_WAKESOR) {
13102 			tp->t_flags &= ~TF_WAKESOR;
13103 			/* NB: sorwakeup_locked() does an implicit unlock. */
13104 			sorwakeup_locked(so);
13105 		}
13106 	}
13107 	tp->snd_wl1 = th->th_seq - 1;
13108 	/* For syn-recv we need to possibly update the rtt */
13109 	if ((to->to_flags & TOF_TS) != 0 && to->to_tsecr) {
13110 		uint32_t t, mcts;
13111 
13112 		mcts = tcp_ts_getticks();
13113 		t = (mcts - to->to_tsecr) * HPTS_USEC_IN_MSEC;
13114 		if (!tp->t_rttlow || tp->t_rttlow > t)
13115 			tp->t_rttlow = t;
13116 		rack_log_rtt_sample_calc(rack, t, (to->to_tsecr * 1000), (mcts * 1000), 5);
13117 		tcp_rack_xmit_timer(rack, t + 1, 1, t, 0, NULL, 2);
13118 		tcp_rack_xmit_timer_commit(rack, tp);
13119 	}
13120 	if (rack_process_ack(m, th, so, tp, to, tiwin, tlen, &ourfinisacked, thflags, &ret_val, orig_tlen)) {
13121 		return (ret_val);
13122 	}
13123 	if (tp->t_state == TCPS_FIN_WAIT_1) {
13124 		/* We could have went to FIN_WAIT_1 (or EST) above */
13125 		/*
13126 		 * In FIN_WAIT_1 STATE in addition to the processing for the
13127 		 * ESTABLISHED state if our FIN is now acknowledged then
13128 		 * enter FIN_WAIT_2.
13129 		 */
13130 		if (ourfinisacked) {
13131 			/*
13132 			 * If we can't receive any more data, then closing
13133 			 * user can proceed. Starting the timer is contrary
13134 			 * to the specification, but if we don't get a FIN
13135 			 * we'll hang forever.
13136 			 *
13137 			 * XXXjl: we should release the tp also, and use a
13138 			 * compressed state.
13139 			 */
13140 			if (so->so_rcv.sb_state & SBS_CANTRCVMORE) {
13141 				soisdisconnected(so);
13142 				tcp_timer_activate(tp, TT_2MSL,
13143 				    (tcp_fast_finwait2_recycle ?
13144 				    tcp_finwait2_timeout :
13145 				    TP_MAXIDLE(tp)));
13146 			}
13147 			tcp_state_change(tp, TCPS_FIN_WAIT_2);
13148 		}
13149 	}
13150 	return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
13151 	    tiwin, thflags, nxt_pkt));
13152 }
13153 
13154 /*
13155  * Return value of 1, the TCB is unlocked and most
13156  * likely gone, return value of 0, the TCP is still
13157  * locked.
13158  */
13159 static int
13160 rack_do_established(struct mbuf *m, struct tcphdr *th, struct socket *so,
13161     struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen,
13162     uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos)
13163 {
13164 	int32_t ret_val = 0;
13165 	int32_t orig_tlen = tlen;
13166 	struct tcp_rack *rack;
13167 
13168 	/*
13169 	 * Header prediction: check for the two common cases of a
13170 	 * uni-directional data xfer.  If the packet has no control flags,
13171 	 * is in-sequence, the window didn't change and we're not
13172 	 * retransmitting, it's a candidate.  If the length is zero and the
13173 	 * ack moved forward, we're the sender side of the xfer.  Just free
13174 	 * the data acked & wake any higher level process that was blocked
13175 	 * waiting for space.  If the length is non-zero and the ack didn't
13176 	 * move, we're the receiver side.  If we're getting packets in-order
13177 	 * (the reassembly queue is empty), add the data toc The socket
13178 	 * buffer and note that we need a delayed ack. Make sure that the
13179 	 * hidden state-flags are also off. Since we check for
13180 	 * TCPS_ESTABLISHED first, it can only be TH_NEEDSYN.
13181 	 */
13182 	rack = (struct tcp_rack *)tp->t_fb_ptr;
13183 	if (__predict_true(((to->to_flags & TOF_SACK) == 0)) &&
13184 	    __predict_true((thflags & (TH_SYN | TH_FIN | TH_RST | TH_ACK)) == TH_ACK) &&
13185 	    __predict_true(SEGQ_EMPTY(tp)) &&
13186 	    __predict_true(th->th_seq == tp->rcv_nxt)) {
13187 		if (tlen == 0) {
13188 			if (rack_fastack(m, th, so, tp, to, drop_hdrlen, tlen,
13189 			    tiwin, nxt_pkt, rack->r_ctl.rc_rcvtime)) {
13190 				return (0);
13191 			}
13192 		} else {
13193 			if (rack_do_fastnewdata(m, th, so, tp, to, drop_hdrlen, tlen,
13194 			    tiwin, nxt_pkt, iptos)) {
13195 				return (0);
13196 			}
13197 		}
13198 	}
13199 	ctf_calc_rwin(so, tp);
13200 
13201 	if ((thflags & TH_RST) ||
13202 	    (tp->t_fin_is_rst && (thflags & TH_FIN)))
13203 		return (ctf_process_rst(m, th, so, tp));
13204 
13205 	/*
13206 	 * RFC5961 Section 4.2 Send challenge ACK for any SYN in
13207 	 * synchronized state.
13208 	 */
13209 	if (thflags & TH_SYN) {
13210 		ctf_challenge_ack(m, th, tp, iptos, &ret_val);
13211 		return (ret_val);
13212 	}
13213 	/*
13214 	 * RFC 1323 PAWS: If we have a timestamp reply on this segment and
13215 	 * it's less than ts_recent, drop it.
13216 	 */
13217 	if ((to->to_flags & TOF_TS) != 0 && tp->ts_recent &&
13218 	    TSTMP_LT(to->to_tsval, tp->ts_recent)) {
13219 		if (ctf_ts_check(m, th, tp, tlen, thflags, &ret_val))
13220 			return (ret_val);
13221 	}
13222 	if (ctf_drop_checks(to, m, th, tp, &tlen, &thflags, &drop_hdrlen, &ret_val)) {
13223 		return (ret_val);
13224 	}
13225 	/*
13226 	 * If last ACK falls within this segment's sequence numbers, record
13227 	 * its timestamp. NOTE: 1) That the test incorporates suggestions
13228 	 * from the latest proposal of the tcplw@cray.com list (Braden
13229 	 * 1993/04/26). 2) That updating only on newer timestamps interferes
13230 	 * with our earlier PAWS tests, so this check should be solely
13231 	 * predicated on the sequence space of this segment. 3) That we
13232 	 * modify the segment boundary check to be Last.ACK.Sent <= SEG.SEQ
13233 	 * + SEG.Len  instead of RFC1323's Last.ACK.Sent < SEG.SEQ +
13234 	 * SEG.Len, This modified check allows us to overcome RFC1323's
13235 	 * limitations as described in Stevens TCP/IP Illustrated Vol. 2
13236 	 * p.869. In such cases, we can still calculate the RTT correctly
13237 	 * when RCV.NXT == Last.ACK.Sent.
13238 	 */
13239 	if ((to->to_flags & TOF_TS) != 0 &&
13240 	    SEQ_LEQ(th->th_seq, tp->last_ack_sent) &&
13241 	    SEQ_LEQ(tp->last_ack_sent, th->th_seq + tlen +
13242 	    ((thflags & (TH_SYN | TH_FIN)) != 0))) {
13243 		tp->ts_recent_age = tcp_ts_getticks();
13244 		tp->ts_recent = to->to_tsval;
13245 	}
13246 	/*
13247 	 * If the ACK bit is off:  if in SYN-RECEIVED state or SENDSYN flag
13248 	 * is on (half-synchronized state), then queue data for later
13249 	 * processing; else drop segment and return.
13250 	 */
13251 	if ((thflags & TH_ACK) == 0) {
13252 		if (tp->t_flags & TF_NEEDSYN) {
13253 			return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
13254 			    tiwin, thflags, nxt_pkt));
13255 
13256 		} else if (tp->t_flags & TF_ACKNOW) {
13257 			ctf_do_dropafterack(m, tp, th, thflags, tlen, &ret_val);
13258 			((struct tcp_rack *)tp->t_fb_ptr)->r_wanted_output = 1;
13259 			return (ret_val);
13260 		} else {
13261 			ctf_do_drop(m, NULL);
13262 			return (0);
13263 		}
13264 	}
13265 	/*
13266 	 * Ack processing.
13267 	 */
13268 	if (rack_process_ack(m, th, so, tp, to, tiwin, tlen, NULL, thflags, &ret_val, orig_tlen)) {
13269 		return (ret_val);
13270 	}
13271 	if (sbavail(&so->so_snd)) {
13272 		if (ctf_progress_timeout_check(tp, true)) {
13273 			rack_log_progress_event(rack, tp, tick, PROGRESS_DROP, __LINE__);
13274 			ctf_do_dropwithreset_conn(m, tp, th, tlen);
13275 			return (1);
13276 		}
13277 	}
13278 	/* State changes only happen in rack_process_data() */
13279 	return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
13280 	    tiwin, thflags, nxt_pkt));
13281 }
13282 
13283 /*
13284  * Return value of 1, the TCB is unlocked and most
13285  * likely gone, return value of 0, the TCP is still
13286  * locked.
13287  */
13288 static int
13289 rack_do_close_wait(struct mbuf *m, struct tcphdr *th, struct socket *so,
13290     struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen,
13291     uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos)
13292 {
13293 	int32_t ret_val = 0;
13294 	int32_t orig_tlen = tlen;
13295 
13296 	ctf_calc_rwin(so, tp);
13297 	if ((thflags & TH_RST) ||
13298 	    (tp->t_fin_is_rst && (thflags & TH_FIN)))
13299 		return (ctf_process_rst(m, th, so, tp));
13300 	/*
13301 	 * RFC5961 Section 4.2 Send challenge ACK for any SYN in
13302 	 * synchronized state.
13303 	 */
13304 	if (thflags & TH_SYN) {
13305 		ctf_challenge_ack(m, th, tp, iptos, &ret_val);
13306 		return (ret_val);
13307 	}
13308 	/*
13309 	 * RFC 1323 PAWS: If we have a timestamp reply on this segment and
13310 	 * it's less than ts_recent, drop it.
13311 	 */
13312 	if ((to->to_flags & TOF_TS) != 0 && tp->ts_recent &&
13313 	    TSTMP_LT(to->to_tsval, tp->ts_recent)) {
13314 		if (ctf_ts_check(m, th, tp, tlen, thflags, &ret_val))
13315 			return (ret_val);
13316 	}
13317 	if (ctf_drop_checks(to, m, th, tp, &tlen, &thflags, &drop_hdrlen, &ret_val)) {
13318 		return (ret_val);
13319 	}
13320 	/*
13321 	 * If last ACK falls within this segment's sequence numbers, record
13322 	 * its timestamp. NOTE: 1) That the test incorporates suggestions
13323 	 * from the latest proposal of the tcplw@cray.com list (Braden
13324 	 * 1993/04/26). 2) That updating only on newer timestamps interferes
13325 	 * with our earlier PAWS tests, so this check should be solely
13326 	 * predicated on the sequence space of this segment. 3) That we
13327 	 * modify the segment boundary check to be Last.ACK.Sent <= SEG.SEQ
13328 	 * + SEG.Len  instead of RFC1323's Last.ACK.Sent < SEG.SEQ +
13329 	 * SEG.Len, This modified check allows us to overcome RFC1323's
13330 	 * limitations as described in Stevens TCP/IP Illustrated Vol. 2
13331 	 * p.869. In such cases, we can still calculate the RTT correctly
13332 	 * when RCV.NXT == Last.ACK.Sent.
13333 	 */
13334 	if ((to->to_flags & TOF_TS) != 0 &&
13335 	    SEQ_LEQ(th->th_seq, tp->last_ack_sent) &&
13336 	    SEQ_LEQ(tp->last_ack_sent, th->th_seq + tlen +
13337 	    ((thflags & (TH_SYN | TH_FIN)) != 0))) {
13338 		tp->ts_recent_age = tcp_ts_getticks();
13339 		tp->ts_recent = to->to_tsval;
13340 	}
13341 	/*
13342 	 * If the ACK bit is off:  if in SYN-RECEIVED state or SENDSYN flag
13343 	 * is on (half-synchronized state), then queue data for later
13344 	 * processing; else drop segment and return.
13345 	 */
13346 	if ((thflags & TH_ACK) == 0) {
13347 		if (tp->t_flags & TF_NEEDSYN) {
13348 			return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
13349 			    tiwin, thflags, nxt_pkt));
13350 
13351 		} else if (tp->t_flags & TF_ACKNOW) {
13352 			ctf_do_dropafterack(m, tp, th, thflags, tlen, &ret_val);
13353 			((struct tcp_rack *)tp->t_fb_ptr)->r_wanted_output = 1;
13354 			return (ret_val);
13355 		} else {
13356 			ctf_do_drop(m, NULL);
13357 			return (0);
13358 		}
13359 	}
13360 	/*
13361 	 * Ack processing.
13362 	 */
13363 	if (rack_process_ack(m, th, so, tp, to, tiwin, tlen, NULL, thflags, &ret_val, orig_tlen)) {
13364 		return (ret_val);
13365 	}
13366 	if (sbavail(&so->so_snd)) {
13367 		if (ctf_progress_timeout_check(tp, true)) {
13368 			rack_log_progress_event((struct tcp_rack *)tp->t_fb_ptr,
13369 						tp, tick, PROGRESS_DROP, __LINE__);
13370 			ctf_do_dropwithreset_conn(m, tp, th, tlen);
13371 			return (1);
13372 		}
13373 	}
13374 	return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
13375 	    tiwin, thflags, nxt_pkt));
13376 }
13377 
13378 static int
13379 rack_check_data_after_close(struct mbuf *m,
13380     struct tcpcb *tp, int32_t *tlen, struct tcphdr *th, struct socket *so)
13381 {
13382 	struct tcp_rack *rack;
13383 
13384 	rack = (struct tcp_rack *)tp->t_fb_ptr;
13385 	if (rack->rc_allow_data_af_clo == 0) {
13386 	close_now:
13387 		tcp_log_end_status(tp, TCP_EI_STATUS_DATA_A_CLOSE);
13388 		/* tcp_close will kill the inp pre-log the Reset */
13389 		tcp_log_end_status(tp, TCP_EI_STATUS_SERVER_RST);
13390 		tp = tcp_close(tp);
13391 		KMOD_TCPSTAT_INC(tcps_rcvafterclose);
13392 		ctf_do_dropwithreset(m, tp, th, *tlen);
13393 		return (1);
13394 	}
13395 	if (sbavail(&so->so_snd) == 0)
13396 		goto close_now;
13397 	/* Ok we allow data that is ignored and a followup reset */
13398 	tcp_log_end_status(tp, TCP_EI_STATUS_DATA_A_CLOSE);
13399 	tp->rcv_nxt = th->th_seq + *tlen;
13400 	tp->t_flags2 |= TF2_DROP_AF_DATA;
13401 	rack->r_wanted_output = 1;
13402 	*tlen = 0;
13403 	return (0);
13404 }
13405 
13406 /*
13407  * Return value of 1, the TCB is unlocked and most
13408  * likely gone, return value of 0, the TCP is still
13409  * locked.
13410  */
13411 static int
13412 rack_do_fin_wait_1(struct mbuf *m, struct tcphdr *th, struct socket *so,
13413     struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen,
13414     uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos)
13415 {
13416 	int32_t ret_val = 0;
13417 	int32_t orig_tlen = tlen;
13418 	int32_t ourfinisacked = 0;
13419 
13420 	ctf_calc_rwin(so, tp);
13421 
13422 	if ((thflags & TH_RST) ||
13423 	    (tp->t_fin_is_rst && (thflags & TH_FIN)))
13424 		return (ctf_process_rst(m, th, so, tp));
13425 	/*
13426 	 * RFC5961 Section 4.2 Send challenge ACK for any SYN in
13427 	 * synchronized state.
13428 	 */
13429 	if (thflags & TH_SYN) {
13430 		ctf_challenge_ack(m, th, tp, iptos, &ret_val);
13431 		return (ret_val);
13432 	}
13433 	/*
13434 	 * RFC 1323 PAWS: If we have a timestamp reply on this segment and
13435 	 * it's less than ts_recent, drop it.
13436 	 */
13437 	if ((to->to_flags & TOF_TS) != 0 && tp->ts_recent &&
13438 	    TSTMP_LT(to->to_tsval, tp->ts_recent)) {
13439 		if (ctf_ts_check(m, th, tp, tlen, thflags, &ret_val))
13440 			return (ret_val);
13441 	}
13442 	if (ctf_drop_checks(to, m, th, tp, &tlen, &thflags, &drop_hdrlen, &ret_val)) {
13443 		return (ret_val);
13444 	}
13445 	/*
13446 	 * If new data are received on a connection after the user processes
13447 	 * are gone, then RST the other end.
13448 	 */
13449 	if ((tp->t_flags & TF_CLOSED) && tlen &&
13450 	    rack_check_data_after_close(m, tp, &tlen, th, so))
13451 		return (1);
13452 	/*
13453 	 * If last ACK falls within this segment's sequence numbers, record
13454 	 * its timestamp. NOTE: 1) That the test incorporates suggestions
13455 	 * from the latest proposal of the tcplw@cray.com list (Braden
13456 	 * 1993/04/26). 2) That updating only on newer timestamps interferes
13457 	 * with our earlier PAWS tests, so this check should be solely
13458 	 * predicated on the sequence space of this segment. 3) That we
13459 	 * modify the segment boundary check to be Last.ACK.Sent <= SEG.SEQ
13460 	 * + SEG.Len  instead of RFC1323's Last.ACK.Sent < SEG.SEQ +
13461 	 * SEG.Len, This modified check allows us to overcome RFC1323's
13462 	 * limitations as described in Stevens TCP/IP Illustrated Vol. 2
13463 	 * p.869. In such cases, we can still calculate the RTT correctly
13464 	 * when RCV.NXT == Last.ACK.Sent.
13465 	 */
13466 	if ((to->to_flags & TOF_TS) != 0 &&
13467 	    SEQ_LEQ(th->th_seq, tp->last_ack_sent) &&
13468 	    SEQ_LEQ(tp->last_ack_sent, th->th_seq + tlen +
13469 	    ((thflags & (TH_SYN | TH_FIN)) != 0))) {
13470 		tp->ts_recent_age = tcp_ts_getticks();
13471 		tp->ts_recent = to->to_tsval;
13472 	}
13473 	/*
13474 	 * If the ACK bit is off:  if in SYN-RECEIVED state or SENDSYN flag
13475 	 * is on (half-synchronized state), then queue data for later
13476 	 * processing; else drop segment and return.
13477 	 */
13478 	if ((thflags & TH_ACK) == 0) {
13479 		if (tp->t_flags & TF_NEEDSYN) {
13480 			return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
13481 			    tiwin, thflags, nxt_pkt));
13482 		} else if (tp->t_flags & TF_ACKNOW) {
13483 			ctf_do_dropafterack(m, tp, th, thflags, tlen, &ret_val);
13484 			((struct tcp_rack *)tp->t_fb_ptr)->r_wanted_output = 1;
13485 			return (ret_val);
13486 		} else {
13487 			ctf_do_drop(m, NULL);
13488 			return (0);
13489 		}
13490 	}
13491 	/*
13492 	 * Ack processing.
13493 	 */
13494 	if (rack_process_ack(m, th, so, tp, to, tiwin, tlen, &ourfinisacked, thflags, &ret_val, orig_tlen)) {
13495 		return (ret_val);
13496 	}
13497 	if (ourfinisacked) {
13498 		/*
13499 		 * If we can't receive any more data, then closing user can
13500 		 * proceed. Starting the timer is contrary to the
13501 		 * specification, but if we don't get a FIN we'll hang
13502 		 * forever.
13503 		 *
13504 		 * XXXjl: we should release the tp also, and use a
13505 		 * compressed state.
13506 		 */
13507 		if (so->so_rcv.sb_state & SBS_CANTRCVMORE) {
13508 			soisdisconnected(so);
13509 			tcp_timer_activate(tp, TT_2MSL,
13510 			    (tcp_fast_finwait2_recycle ?
13511 			    tcp_finwait2_timeout :
13512 			    TP_MAXIDLE(tp)));
13513 		}
13514 		tcp_state_change(tp, TCPS_FIN_WAIT_2);
13515 	}
13516 	if (sbavail(&so->so_snd)) {
13517 		if (ctf_progress_timeout_check(tp, true)) {
13518 			rack_log_progress_event((struct tcp_rack *)tp->t_fb_ptr,
13519 						tp, tick, PROGRESS_DROP, __LINE__);
13520 			ctf_do_dropwithreset_conn(m, tp, th, tlen);
13521 			return (1);
13522 		}
13523 	}
13524 	return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
13525 	    tiwin, thflags, nxt_pkt));
13526 }
13527 
13528 /*
13529  * Return value of 1, the TCB is unlocked and most
13530  * likely gone, return value of 0, the TCP is still
13531  * locked.
13532  */
13533 static int
13534 rack_do_closing(struct mbuf *m, struct tcphdr *th, struct socket *so,
13535     struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen,
13536     uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos)
13537 {
13538 	int32_t ret_val = 0;
13539 	int32_t orig_tlen = tlen;
13540 	int32_t ourfinisacked = 0;
13541 
13542 	ctf_calc_rwin(so, tp);
13543 
13544 	if ((thflags & TH_RST) ||
13545 	    (tp->t_fin_is_rst && (thflags & TH_FIN)))
13546 		return (ctf_process_rst(m, th, so, tp));
13547 	/*
13548 	 * RFC5961 Section 4.2 Send challenge ACK for any SYN in
13549 	 * synchronized state.
13550 	 */
13551 	if (thflags & TH_SYN) {
13552 		ctf_challenge_ack(m, th, tp, iptos, &ret_val);
13553 		return (ret_val);
13554 	}
13555 	/*
13556 	 * RFC 1323 PAWS: If we have a timestamp reply on this segment and
13557 	 * it's less than ts_recent, drop it.
13558 	 */
13559 	if ((to->to_flags & TOF_TS) != 0 && tp->ts_recent &&
13560 	    TSTMP_LT(to->to_tsval, tp->ts_recent)) {
13561 		if (ctf_ts_check(m, th, tp, tlen, thflags, &ret_val))
13562 			return (ret_val);
13563 	}
13564 	if (ctf_drop_checks(to, m, th, tp, &tlen, &thflags, &drop_hdrlen, &ret_val)) {
13565 		return (ret_val);
13566 	}
13567 	/*
13568 	 * If last ACK falls within this segment's sequence numbers, record
13569 	 * its timestamp. NOTE: 1) That the test incorporates suggestions
13570 	 * from the latest proposal of the tcplw@cray.com list (Braden
13571 	 * 1993/04/26). 2) That updating only on newer timestamps interferes
13572 	 * with our earlier PAWS tests, so this check should be solely
13573 	 * predicated on the sequence space of this segment. 3) That we
13574 	 * modify the segment boundary check to be Last.ACK.Sent <= SEG.SEQ
13575 	 * + SEG.Len  instead of RFC1323's Last.ACK.Sent < SEG.SEQ +
13576 	 * SEG.Len, This modified check allows us to overcome RFC1323's
13577 	 * limitations as described in Stevens TCP/IP Illustrated Vol. 2
13578 	 * p.869. In such cases, we can still calculate the RTT correctly
13579 	 * when RCV.NXT == Last.ACK.Sent.
13580 	 */
13581 	if ((to->to_flags & TOF_TS) != 0 &&
13582 	    SEQ_LEQ(th->th_seq, tp->last_ack_sent) &&
13583 	    SEQ_LEQ(tp->last_ack_sent, th->th_seq + tlen +
13584 	    ((thflags & (TH_SYN | TH_FIN)) != 0))) {
13585 		tp->ts_recent_age = tcp_ts_getticks();
13586 		tp->ts_recent = to->to_tsval;
13587 	}
13588 	/*
13589 	 * If the ACK bit is off:  if in SYN-RECEIVED state or SENDSYN flag
13590 	 * is on (half-synchronized state), then queue data for later
13591 	 * processing; else drop segment and return.
13592 	 */
13593 	if ((thflags & TH_ACK) == 0) {
13594 		if (tp->t_flags & TF_NEEDSYN) {
13595 			return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
13596 			    tiwin, thflags, nxt_pkt));
13597 		} else if (tp->t_flags & TF_ACKNOW) {
13598 			ctf_do_dropafterack(m, tp, th, thflags, tlen, &ret_val);
13599 			((struct tcp_rack *)tp->t_fb_ptr)->r_wanted_output = 1;
13600 			return (ret_val);
13601 		} else {
13602 			ctf_do_drop(m, NULL);
13603 			return (0);
13604 		}
13605 	}
13606 	/*
13607 	 * Ack processing.
13608 	 */
13609 	if (rack_process_ack(m, th, so, tp, to, tiwin, tlen, &ourfinisacked, thflags, &ret_val, orig_tlen)) {
13610 		return (ret_val);
13611 	}
13612 	if (ourfinisacked) {
13613 		tcp_twstart(tp);
13614 		m_freem(m);
13615 		return (1);
13616 	}
13617 	if (sbavail(&so->so_snd)) {
13618 		if (ctf_progress_timeout_check(tp, true)) {
13619 			rack_log_progress_event((struct tcp_rack *)tp->t_fb_ptr,
13620 						tp, tick, PROGRESS_DROP, __LINE__);
13621 			ctf_do_dropwithreset_conn(m, tp, th, tlen);
13622 			return (1);
13623 		}
13624 	}
13625 	return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
13626 	    tiwin, thflags, nxt_pkt));
13627 }
13628 
13629 /*
13630  * Return value of 1, the TCB is unlocked and most
13631  * likely gone, return value of 0, the TCP is still
13632  * locked.
13633  */
13634 static int
13635 rack_do_lastack(struct mbuf *m, struct tcphdr *th, struct socket *so,
13636     struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen,
13637     uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos)
13638 {
13639 	int32_t ret_val = 0;
13640 	int32_t orig_tlen;
13641 	int32_t ourfinisacked = 0;
13642 
13643 	ctf_calc_rwin(so, tp);
13644 
13645 	if ((thflags & TH_RST) ||
13646 	    (tp->t_fin_is_rst && (thflags & TH_FIN)))
13647 		return (ctf_process_rst(m, th, so, tp));
13648 	/*
13649 	 * RFC5961 Section 4.2 Send challenge ACK for any SYN in
13650 	 * synchronized state.
13651 	 */
13652 	if (thflags & TH_SYN) {
13653 		ctf_challenge_ack(m, th, tp, iptos, &ret_val);
13654 		return (ret_val);
13655 	}
13656 	/*
13657 	 * RFC 1323 PAWS: If we have a timestamp reply on this segment and
13658 	 * it's less than ts_recent, drop it.
13659 	 */
13660 	if ((to->to_flags & TOF_TS) != 0 && tp->ts_recent &&
13661 	    TSTMP_LT(to->to_tsval, tp->ts_recent)) {
13662 		if (ctf_ts_check(m, th, tp, tlen, thflags, &ret_val))
13663 			return (ret_val);
13664 	}
13665 	orig_tlen = tlen;
13666 	if (ctf_drop_checks(to, m, th, tp, &tlen, &thflags, &drop_hdrlen, &ret_val)) {
13667 		return (ret_val);
13668 	}
13669 	/*
13670 	 * If last ACK falls within this segment's sequence numbers, record
13671 	 * its timestamp. NOTE: 1) That the test incorporates suggestions
13672 	 * from the latest proposal of the tcplw@cray.com list (Braden
13673 	 * 1993/04/26). 2) That updating only on newer timestamps interferes
13674 	 * with our earlier PAWS tests, so this check should be solely
13675 	 * predicated on the sequence space of this segment. 3) That we
13676 	 * modify the segment boundary check to be Last.ACK.Sent <= SEG.SEQ
13677 	 * + SEG.Len  instead of RFC1323's Last.ACK.Sent < SEG.SEQ +
13678 	 * SEG.Len, This modified check allows us to overcome RFC1323's
13679 	 * limitations as described in Stevens TCP/IP Illustrated Vol. 2
13680 	 * p.869. In such cases, we can still calculate the RTT correctly
13681 	 * when RCV.NXT == Last.ACK.Sent.
13682 	 */
13683 	if ((to->to_flags & TOF_TS) != 0 &&
13684 	    SEQ_LEQ(th->th_seq, tp->last_ack_sent) &&
13685 	    SEQ_LEQ(tp->last_ack_sent, th->th_seq + tlen +
13686 	    ((thflags & (TH_SYN | TH_FIN)) != 0))) {
13687 		tp->ts_recent_age = tcp_ts_getticks();
13688 		tp->ts_recent = to->to_tsval;
13689 	}
13690 	/*
13691 	 * If the ACK bit is off:  if in SYN-RECEIVED state or SENDSYN flag
13692 	 * is on (half-synchronized state), then queue data for later
13693 	 * processing; else drop segment and return.
13694 	 */
13695 	if ((thflags & TH_ACK) == 0) {
13696 		if (tp->t_flags & TF_NEEDSYN) {
13697 			return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
13698 			    tiwin, thflags, nxt_pkt));
13699 		} else if (tp->t_flags & TF_ACKNOW) {
13700 			ctf_do_dropafterack(m, tp, th, thflags, tlen, &ret_val);
13701 			((struct tcp_rack *)tp->t_fb_ptr)->r_wanted_output = 1;
13702 			return (ret_val);
13703 		} else {
13704 			ctf_do_drop(m, NULL);
13705 			return (0);
13706 		}
13707 	}
13708 	/*
13709 	 * case TCPS_LAST_ACK: Ack processing.
13710 	 */
13711 	if (rack_process_ack(m, th, so, tp, to, tiwin, tlen, &ourfinisacked, thflags, &ret_val, orig_tlen)) {
13712 		return (ret_val);
13713 	}
13714 	if (ourfinisacked) {
13715 		tp = tcp_close(tp);
13716 		ctf_do_drop(m, tp);
13717 		return (1);
13718 	}
13719 	if (sbavail(&so->so_snd)) {
13720 		if (ctf_progress_timeout_check(tp, true)) {
13721 			rack_log_progress_event((struct tcp_rack *)tp->t_fb_ptr,
13722 						tp, tick, PROGRESS_DROP, __LINE__);
13723 			ctf_do_dropwithreset_conn(m, tp, th, tlen);
13724 			return (1);
13725 		}
13726 	}
13727 	return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
13728 	    tiwin, thflags, nxt_pkt));
13729 }
13730 
13731 /*
13732  * Return value of 1, the TCB is unlocked and most
13733  * likely gone, return value of 0, the TCP is still
13734  * locked.
13735  */
13736 static int
13737 rack_do_fin_wait_2(struct mbuf *m, struct tcphdr *th, struct socket *so,
13738     struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen,
13739     uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos)
13740 {
13741 	int32_t ret_val = 0;
13742 	int32_t orig_tlen = tlen;
13743 	int32_t ourfinisacked = 0;
13744 
13745 	ctf_calc_rwin(so, tp);
13746 
13747 	/* Reset receive buffer auto scaling when not in bulk receive mode. */
13748 	if ((thflags & TH_RST) ||
13749 	    (tp->t_fin_is_rst && (thflags & TH_FIN)))
13750 		return (ctf_process_rst(m, th, so, tp));
13751 	/*
13752 	 * RFC5961 Section 4.2 Send challenge ACK for any SYN in
13753 	 * synchronized state.
13754 	 */
13755 	if (thflags & TH_SYN) {
13756 		ctf_challenge_ack(m, th, tp, iptos, &ret_val);
13757 		return (ret_val);
13758 	}
13759 	/*
13760 	 * RFC 1323 PAWS: If we have a timestamp reply on this segment and
13761 	 * it's less than ts_recent, drop it.
13762 	 */
13763 	if ((to->to_flags & TOF_TS) != 0 && tp->ts_recent &&
13764 	    TSTMP_LT(to->to_tsval, tp->ts_recent)) {
13765 		if (ctf_ts_check(m, th, tp, tlen, thflags, &ret_val))
13766 			return (ret_val);
13767 	}
13768 	if (ctf_drop_checks(to, m, th, tp, &tlen, &thflags, &drop_hdrlen, &ret_val)) {
13769 		return (ret_val);
13770 	}
13771 	/*
13772 	 * If new data are received on a connection after the user processes
13773 	 * are gone, then RST the other end.
13774 	 */
13775 	if ((tp->t_flags & TF_CLOSED) && tlen &&
13776 	    rack_check_data_after_close(m, tp, &tlen, th, so))
13777 		return (1);
13778 	/*
13779 	 * If last ACK falls within this segment's sequence numbers, record
13780 	 * its timestamp. NOTE: 1) That the test incorporates suggestions
13781 	 * from the latest proposal of the tcplw@cray.com list (Braden
13782 	 * 1993/04/26). 2) That updating only on newer timestamps interferes
13783 	 * with our earlier PAWS tests, so this check should be solely
13784 	 * predicated on the sequence space of this segment. 3) That we
13785 	 * modify the segment boundary check to be Last.ACK.Sent <= SEG.SEQ
13786 	 * + SEG.Len  instead of RFC1323's Last.ACK.Sent < SEG.SEQ +
13787 	 * SEG.Len, This modified check allows us to overcome RFC1323's
13788 	 * limitations as described in Stevens TCP/IP Illustrated Vol. 2
13789 	 * p.869. In such cases, we can still calculate the RTT correctly
13790 	 * when RCV.NXT == Last.ACK.Sent.
13791 	 */
13792 	if ((to->to_flags & TOF_TS) != 0 &&
13793 	    SEQ_LEQ(th->th_seq, tp->last_ack_sent) &&
13794 	    SEQ_LEQ(tp->last_ack_sent, th->th_seq + tlen +
13795 	    ((thflags & (TH_SYN | TH_FIN)) != 0))) {
13796 		tp->ts_recent_age = tcp_ts_getticks();
13797 		tp->ts_recent = to->to_tsval;
13798 	}
13799 	/*
13800 	 * If the ACK bit is off:  if in SYN-RECEIVED state or SENDSYN flag
13801 	 * is on (half-synchronized state), then queue data for later
13802 	 * processing; else drop segment and return.
13803 	 */
13804 	if ((thflags & TH_ACK) == 0) {
13805 		if (tp->t_flags & TF_NEEDSYN) {
13806 			return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
13807 			    tiwin, thflags, nxt_pkt));
13808 		} else if (tp->t_flags & TF_ACKNOW) {
13809 			ctf_do_dropafterack(m, tp, th, thflags, tlen, &ret_val);
13810 			((struct tcp_rack *)tp->t_fb_ptr)->r_wanted_output = 1;
13811 			return (ret_val);
13812 		} else {
13813 			ctf_do_drop(m, NULL);
13814 			return (0);
13815 		}
13816 	}
13817 	/*
13818 	 * Ack processing.
13819 	 */
13820 	if (rack_process_ack(m, th, so, tp, to, tiwin, tlen, &ourfinisacked, thflags, &ret_val, orig_tlen)) {
13821 		return (ret_val);
13822 	}
13823 	if (sbavail(&so->so_snd)) {
13824 		if (ctf_progress_timeout_check(tp, true)) {
13825 			rack_log_progress_event((struct tcp_rack *)tp->t_fb_ptr,
13826 						tp, tick, PROGRESS_DROP, __LINE__);
13827 			ctf_do_dropwithreset_conn(m, tp, th, tlen);
13828 			return (1);
13829 		}
13830 	}
13831 	return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
13832 	    tiwin, thflags, nxt_pkt));
13833 }
13834 
13835 static void inline
13836 rack_clear_rate_sample(struct tcp_rack *rack)
13837 {
13838 	rack->r_ctl.rack_rs.rs_flags = RACK_RTT_EMPTY;
13839 	rack->r_ctl.rack_rs.rs_rtt_cnt = 0;
13840 	rack->r_ctl.rack_rs.rs_rtt_tot = 0;
13841 }
13842 
13843 static void
13844 rack_set_pace_segments(struct tcpcb *tp, struct tcp_rack *rack, uint32_t line, uint64_t *fill_override)
13845 {
13846 	uint64_t bw_est, rate_wanted;
13847 	int chged = 0;
13848 	uint32_t user_max, orig_min, orig_max;
13849 
13850 #ifdef TCP_REQUEST_TRK
13851 	if (rack->rc_hybrid_mode &&
13852 	    (rack->r_ctl.rc_pace_max_segs != 0) &&
13853 	    (rack_hybrid_allow_set_maxseg == 1) &&
13854 	    (rack->r_ctl.rc_last_sft != NULL)) {
13855 		rack->r_ctl.rc_last_sft->hybrid_flags &= ~TCP_HYBRID_PACING_SETMSS;
13856 		return;
13857 	}
13858 #endif
13859 	orig_min = rack->r_ctl.rc_pace_min_segs;
13860 	orig_max = rack->r_ctl.rc_pace_max_segs;
13861 	user_max = ctf_fixed_maxseg(tp) * rack->rc_user_set_max_segs;
13862 	if (ctf_fixed_maxseg(tp) != rack->r_ctl.rc_pace_min_segs)
13863 		chged = 1;
13864 	rack->r_ctl.rc_pace_min_segs = ctf_fixed_maxseg(tp);
13865 	if (rack->use_fixed_rate || rack->rc_force_max_seg) {
13866 		if (user_max != rack->r_ctl.rc_pace_max_segs)
13867 			chged = 1;
13868 	}
13869 	if (rack->rc_force_max_seg) {
13870 		rack->r_ctl.rc_pace_max_segs = user_max;
13871 	} else if (rack->use_fixed_rate) {
13872 		bw_est = rack_get_bw(rack);
13873 		if ((rack->r_ctl.crte == NULL) ||
13874 		    (bw_est != rack->r_ctl.crte->rate)) {
13875 			rack->r_ctl.rc_pace_max_segs = user_max;
13876 		} else {
13877 			/* We are pacing right at the hardware rate */
13878 			uint32_t segsiz, pace_one;
13879 
13880 			if (rack_pace_one_seg ||
13881 			    (rack->r_ctl.rc_user_set_min_segs == 1))
13882 				pace_one = 1;
13883 			else
13884 				pace_one = 0;
13885 			segsiz = min(ctf_fixed_maxseg(tp),
13886 				     rack->r_ctl.rc_pace_min_segs);
13887 			rack->r_ctl.rc_pace_max_segs = tcp_get_pacing_burst_size_w_divisor(
13888 				tp, bw_est, segsiz, pace_one,
13889 				rack->r_ctl.crte, NULL, rack->r_ctl.pace_len_divisor);
13890 		}
13891 	} else if (rack->rc_always_pace) {
13892 		if (rack->r_ctl.gp_bw ||
13893 		    rack->r_ctl.init_rate) {
13894 			/* We have a rate of some sort set */
13895 			uint32_t  orig;
13896 
13897 			bw_est = rack_get_bw(rack);
13898 			orig = rack->r_ctl.rc_pace_max_segs;
13899 			if (fill_override)
13900 				rate_wanted = *fill_override;
13901 			else
13902 				rate_wanted = rack_get_gp_est(rack);
13903 			if (rate_wanted) {
13904 				/* We have something */
13905 				rack->r_ctl.rc_pace_max_segs = rack_get_pacing_len(rack,
13906 										   rate_wanted,
13907 										   ctf_fixed_maxseg(rack->rc_tp));
13908 			} else
13909 				rack->r_ctl.rc_pace_max_segs = rack->r_ctl.rc_pace_min_segs;
13910 			if (orig != rack->r_ctl.rc_pace_max_segs)
13911 				chged = 1;
13912 		} else if ((rack->r_ctl.gp_bw == 0) &&
13913 			   (rack->r_ctl.rc_pace_max_segs == 0)) {
13914 			/*
13915 			 * If we have nothing limit us to bursting
13916 			 * out IW sized pieces.
13917 			 */
13918 			chged = 1;
13919 			rack->r_ctl.rc_pace_max_segs = rc_init_window(rack);
13920 		}
13921 	}
13922 	if (rack->r_ctl.rc_pace_max_segs > PACE_MAX_IP_BYTES) {
13923 		chged = 1;
13924 		rack->r_ctl.rc_pace_max_segs = PACE_MAX_IP_BYTES;
13925 	}
13926 	if (chged)
13927 		rack_log_type_pacing_sizes(tp, rack, orig_min, orig_max, line, 2);
13928 }
13929 
13930 
13931 static void
13932 rack_init_fsb_block(struct tcpcb *tp, struct tcp_rack *rack, int32_t flags)
13933 {
13934 #ifdef INET6
13935 	struct ip6_hdr *ip6 = NULL;
13936 #endif
13937 #ifdef INET
13938 	struct ip *ip = NULL;
13939 #endif
13940 	struct udphdr *udp = NULL;
13941 
13942 	/* Ok lets fill in the fast block, it can only be used with no IP options! */
13943 #ifdef INET6
13944 	if (rack->r_is_v6) {
13945 		rack->r_ctl.fsb.tcp_ip_hdr_len = sizeof(struct ip6_hdr) + sizeof(struct tcphdr);
13946 		ip6 = (struct ip6_hdr *)rack->r_ctl.fsb.tcp_ip_hdr;
13947 		if (tp->t_port) {
13948 			rack->r_ctl.fsb.tcp_ip_hdr_len += sizeof(struct udphdr);
13949 			udp = (struct udphdr *)((caddr_t)ip6 + sizeof(struct ip6_hdr));
13950 			udp->uh_sport = htons(V_tcp_udp_tunneling_port);
13951 			udp->uh_dport = tp->t_port;
13952 			rack->r_ctl.fsb.udp = udp;
13953 			rack->r_ctl.fsb.th = (struct tcphdr *)(udp + 1);
13954 		} else
13955 		{
13956 			rack->r_ctl.fsb.th = (struct tcphdr *)(ip6 + 1);
13957 			rack->r_ctl.fsb.udp = NULL;
13958 		}
13959 		tcpip_fillheaders(rack->rc_inp,
13960 				  tp->t_port,
13961 				  ip6, rack->r_ctl.fsb.th);
13962 		rack->r_ctl.fsb.hoplimit = in6_selecthlim(rack->rc_inp, NULL);
13963 	} else
13964 #endif				/* INET6 */
13965 #ifdef INET
13966 	{
13967 		rack->r_ctl.fsb.tcp_ip_hdr_len = sizeof(struct tcpiphdr);
13968 		ip = (struct ip *)rack->r_ctl.fsb.tcp_ip_hdr;
13969 		if (tp->t_port) {
13970 			rack->r_ctl.fsb.tcp_ip_hdr_len += sizeof(struct udphdr);
13971 			udp = (struct udphdr *)((caddr_t)ip + sizeof(struct ip));
13972 			udp->uh_sport = htons(V_tcp_udp_tunneling_port);
13973 			udp->uh_dport = tp->t_port;
13974 			rack->r_ctl.fsb.udp = udp;
13975 			rack->r_ctl.fsb.th = (struct tcphdr *)(udp + 1);
13976 		} else
13977 		{
13978 			rack->r_ctl.fsb.udp = NULL;
13979 			rack->r_ctl.fsb.th = (struct tcphdr *)(ip + 1);
13980 		}
13981 		tcpip_fillheaders(rack->rc_inp,
13982 				  tp->t_port,
13983 				  ip, rack->r_ctl.fsb.th);
13984 		rack->r_ctl.fsb.hoplimit = tptoinpcb(tp)->inp_ip_ttl;
13985 	}
13986 #endif
13987 	rack->r_ctl.fsb.recwin = lmin(lmax(sbspace(&tptosocket(tp)->so_rcv), 0),
13988 	    (long)TCP_MAXWIN << tp->rcv_scale);
13989 	rack->r_fsb_inited = 1;
13990 }
13991 
13992 static int
13993 rack_init_fsb(struct tcpcb *tp, struct tcp_rack *rack)
13994 {
13995 	/*
13996 	 * Allocate the larger of spaces V6 if available else just
13997 	 * V4 and include udphdr (overbook)
13998 	 */
13999 #ifdef INET6
14000 	rack->r_ctl.fsb.tcp_ip_hdr_len = sizeof(struct ip6_hdr) + sizeof(struct tcphdr) + sizeof(struct udphdr);
14001 #else
14002 	rack->r_ctl.fsb.tcp_ip_hdr_len = sizeof(struct tcpiphdr) + sizeof(struct udphdr);
14003 #endif
14004 	rack->r_ctl.fsb.tcp_ip_hdr = malloc(rack->r_ctl.fsb.tcp_ip_hdr_len,
14005 					    M_TCPFSB, M_NOWAIT|M_ZERO);
14006 	if (rack->r_ctl.fsb.tcp_ip_hdr == NULL) {
14007 		return (ENOMEM);
14008 	}
14009 	rack->r_fsb_inited = 0;
14010 	return (0);
14011 }
14012 
14013 static void
14014 rack_log_hystart_event(struct tcp_rack *rack, uint32_t high_seq, uint8_t mod)
14015 {
14016 	/*
14017 	 * Types of logs (mod value)
14018 	 * 20 - Initial round setup
14019 	 * 21 - Rack declares a new round.
14020 	 */
14021 	struct tcpcb *tp;
14022 
14023 	tp = rack->rc_tp;
14024 	if (tcp_bblogging_on(tp)) {
14025 		union tcp_log_stackspecific log;
14026 		struct timeval tv;
14027 
14028 		memset(&log, 0, sizeof(log));
14029 		log.u_bbr.flex1 = rack->r_ctl.current_round;
14030 		log.u_bbr.flex2 = rack->r_ctl.roundends;
14031 		log.u_bbr.flex3 = high_seq;
14032 		log.u_bbr.flex4 = tp->snd_max;
14033 		log.u_bbr.flex8 = mod;
14034 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
14035 		log.u_bbr.cur_del_rate = rack->rc_tp->t_sndbytes;
14036 		log.u_bbr.delRate = rack->rc_tp->t_snd_rxt_bytes;
14037 		TCP_LOG_EVENTP(tp, NULL,
14038 		    &tptosocket(tp)->so_rcv,
14039 		    &tptosocket(tp)->so_snd,
14040 		    TCP_HYSTART, 0,
14041 		    0, &log, false, &tv);
14042 	}
14043 }
14044 
14045 static void
14046 rack_deferred_init(struct tcpcb *tp, struct tcp_rack *rack)
14047 {
14048 	rack->rack_deferred_inited = 1;
14049 	rack->r_ctl.roundends = tp->snd_max;
14050 	rack->r_ctl.rc_high_rwnd = tp->snd_wnd;
14051 	rack->r_ctl.cwnd_to_use = tp->snd_cwnd;
14052 }
14053 
14054 static void
14055 rack_init_retransmit_value(struct tcp_rack *rack, int ctl)
14056 {
14057 	/* Retransmit bit controls.
14058 	 *
14059 	 * The setting of these values control one of
14060 	 * three settings you can have and dictate
14061 	 * how rack does retransmissions. Note this
14062 	 * is in *any* mode i.e. pacing on or off DGP
14063 	 * fixed rate pacing, or just bursting rack.
14064 	 *
14065 	 * 1 - Use full sized retransmits i.e. limit
14066 	 *     the size to whatever the pace_max_segments
14067 	 *     size is.
14068 	 *
14069 	 * 2 - Use pacer min granularity as a guide to
14070 	 *     the size combined with the current calculated
14071 	 *     goodput b/w measurement. So for example if
14072 	 *     the goodput is measured at 20Mbps we would
14073 	 *     calculate 8125 (pacer minimum 250usec in
14074 	 *     that b/w) and then round it up to the next
14075 	 *     MSS i.e. for 1448 mss 6 MSS or 8688 bytes.
14076 	 *
14077 	 * 0 - The rack default 1 MSS (anything not 0/1/2
14078 	 *     fall here too if we are setting via rack_init()).
14079 	 *
14080 	 */
14081 	if (ctl == 1) {
14082 		rack->full_size_rxt = 1;
14083 		rack->shape_rxt_to_pacing_min  = 0;
14084 	} else if (ctl == 2) {
14085 		rack->full_size_rxt = 0;
14086 		rack->shape_rxt_to_pacing_min  = 1;
14087 	} else {
14088 		rack->full_size_rxt = 0;
14089 		rack->shape_rxt_to_pacing_min  = 0;
14090 	}
14091 }
14092 
14093 static void
14094 rack_log_chg_info(struct tcpcb *tp, struct tcp_rack *rack, uint8_t mod,
14095 		  uint32_t flex1,
14096 		  uint32_t flex2,
14097 		  uint32_t flex3)
14098 {
14099 	if (tcp_bblogging_on(rack->rc_tp)) {
14100 		union tcp_log_stackspecific log;
14101 		struct timeval tv;
14102 
14103 		memset(&log, 0, sizeof(log));
14104 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
14105 		log.u_bbr.flex8 = mod;
14106 		log.u_bbr.flex1 = flex1;
14107 		log.u_bbr.flex2 = flex2;
14108 		log.u_bbr.flex3 = flex3;
14109 		tcp_log_event(tp, NULL, NULL, NULL, TCP_CHG_QUERY, 0,
14110 			       0, &log, false, NULL, __func__, __LINE__, &tv);
14111 	}
14112 }
14113 
14114 static int
14115 rack_chg_query(struct tcpcb *tp, struct tcp_query_resp *reqr)
14116 {
14117 	struct tcp_rack *rack;
14118 	struct rack_sendmap *rsm;
14119 	int i;
14120 
14121 
14122 	rack = (struct tcp_rack *)tp->t_fb_ptr;
14123 	switch (reqr->req) {
14124 	case TCP_QUERY_SENDMAP:
14125 		if ((reqr->req_param == tp->snd_max) ||
14126 		    (tp->snd_max == tp->snd_una)){
14127 			/* Unlikely */
14128 			return (0);
14129 		}
14130 		rsm = tqhash_find(rack->r_ctl.tqh, reqr->req_param);
14131 		if (rsm == NULL) {
14132 			/* Can't find that seq -- unlikely */
14133 			return (0);
14134 		}
14135 		reqr->sendmap_start = rsm->r_start;
14136 		reqr->sendmap_end = rsm->r_end;
14137 		reqr->sendmap_send_cnt = rsm->r_rtr_cnt;
14138 		reqr->sendmap_fas = rsm->r_fas;
14139 		if (reqr->sendmap_send_cnt > SNDMAP_NRTX)
14140 			reqr->sendmap_send_cnt = SNDMAP_NRTX;
14141 		for(i=0; i<reqr->sendmap_send_cnt; i++)
14142 			reqr->sendmap_time[i] = rsm->r_tim_lastsent[i];
14143 		reqr->sendmap_ack_arrival = rsm->r_ack_arrival;
14144 		reqr->sendmap_flags = rsm->r_flags & SNDMAP_MASK;
14145 		reqr->sendmap_r_rtr_bytes = rsm->r_rtr_bytes;
14146 		reqr->sendmap_dupacks = rsm->r_dupack;
14147 		rack_log_chg_info(tp, rack, 1,
14148 				  rsm->r_start,
14149 				  rsm->r_end,
14150 				  rsm->r_flags);
14151 		return(1);
14152 		break;
14153 	case TCP_QUERY_TIMERS_UP:
14154 		if (rack->r_ctl.rc_hpts_flags == 0) {
14155 			/* no timers up */
14156 			return (0);
14157 		}
14158 		reqr->timer_hpts_flags = rack->r_ctl.rc_hpts_flags;
14159 		if (rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT) {
14160 			reqr->timer_pacing_to = rack->r_ctl.rc_last_output_to;
14161 		}
14162 		if (rack->r_ctl.rc_hpts_flags & PACE_TMR_MASK) {
14163 			reqr->timer_timer_exp = rack->r_ctl.rc_timer_exp;
14164 		}
14165 		rack_log_chg_info(tp, rack, 2,
14166 				  rack->r_ctl.rc_hpts_flags,
14167 				  rack->r_ctl.rc_last_output_to,
14168 				  rack->r_ctl.rc_timer_exp);
14169 		return (1);
14170 		break;
14171 	case TCP_QUERY_RACK_TIMES:
14172 		/* Reordering items */
14173 		reqr->rack_num_dsacks = rack->r_ctl.num_dsack;
14174 		reqr->rack_reorder_ts = rack->r_ctl.rc_reorder_ts;
14175 		/* Timerstamps and timers */
14176 		reqr->rack_rxt_last_time = rack->r_ctl.rc_tlp_rxt_last_time;
14177 		reqr->rack_min_rtt = rack->r_ctl.rc_rack_min_rtt;
14178 		reqr->rack_rtt = rack->rc_rack_rtt;
14179 		reqr->rack_tmit_time = rack->r_ctl.rc_rack_tmit_time;
14180 		reqr->rack_srtt_measured = rack->rc_srtt_measure_made;
14181 		/* PRR data */
14182 		reqr->rack_sacked = rack->r_ctl.rc_sacked;
14183 		reqr->rack_holes_rxt = rack->r_ctl.rc_holes_rxt;
14184 		reqr->rack_prr_delivered = rack->r_ctl.rc_prr_delivered;
14185 		reqr->rack_prr_recovery_fs = rack->r_ctl.rc_prr_recovery_fs;
14186 		reqr->rack_prr_sndcnt = rack->r_ctl.rc_prr_sndcnt;
14187 		reqr->rack_prr_out = rack->r_ctl.rc_prr_out;
14188 		/* TLP and persists info */
14189 		reqr->rack_tlp_out = rack->rc_tlp_in_progress;
14190 		reqr->rack_tlp_cnt_out = rack->r_ctl.rc_tlp_cnt_out;
14191 		if (rack->rc_in_persist) {
14192 			reqr->rack_time_went_idle = rack->r_ctl.rc_went_idle_time;
14193 			reqr->rack_in_persist = 1;
14194 		} else {
14195 			reqr->rack_time_went_idle = 0;
14196 			reqr->rack_in_persist = 0;
14197 		}
14198 		if (rack->r_wanted_output)
14199 			reqr->rack_wanted_output = 1;
14200 		else
14201 			reqr->rack_wanted_output = 0;
14202 		return (1);
14203 		break;
14204 	default:
14205 		return (-EINVAL);
14206 	}
14207 }
14208 
14209 static void
14210 rack_switch_failed(struct tcpcb *tp)
14211 {
14212 	/*
14213 	 * This method gets called if a stack switch was
14214 	 * attempted and it failed. We are left
14215 	 * but our hpts timers were stopped and we
14216 	 * need to validate time units and t_flags2.
14217 	 */
14218 	struct tcp_rack *rack;
14219 	struct timeval tv;
14220 	uint32_t cts;
14221 	uint32_t toval;
14222 	struct hpts_diag diag;
14223 
14224 	rack = (struct tcp_rack *)tp->t_fb_ptr;
14225 	tcp_change_time_units(tp, TCP_TMR_GRANULARITY_USEC);
14226 	if  (rack->r_mbuf_queue || rack->rc_always_pace || rack->r_use_cmp_ack)
14227 		tp->t_flags2 |= TF2_SUPPORTS_MBUFQ;
14228 	else
14229 		tp->t_flags2 &= ~TF2_SUPPORTS_MBUFQ;
14230 	if (rack->r_use_cmp_ack && TCPS_HAVEESTABLISHED(tp->t_state))
14231 		tp->t_flags2 |= TF2_MBUF_ACKCMP;
14232 	if (tp->t_in_hpts > IHPTS_NONE) {
14233 		/* Strange */
14234 		return;
14235 	}
14236 	cts = tcp_get_usecs(&tv);
14237 	if (rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT) {
14238 		if (TSTMP_GT(rack->r_ctl.rc_last_output_to, cts)) {
14239 			toval = rack->r_ctl.rc_last_output_to - cts;
14240 		} else {
14241 			/* one slot please */
14242 			toval = HPTS_USECS_PER_SLOT;
14243 		}
14244 	} else if (rack->r_ctl.rc_hpts_flags & PACE_TMR_MASK) {
14245 		if (TSTMP_GT(rack->r_ctl.rc_timer_exp, cts)) {
14246 			toval = rack->r_ctl.rc_timer_exp - cts;
14247 		} else {
14248 			/* one slot please */
14249 			toval = HPTS_USECS_PER_SLOT;
14250 		}
14251 	} else
14252 		toval = HPTS_USECS_PER_SLOT;
14253 	tcp_hpts_insert(tp, toval, &diag);
14254 	rack_log_hpts_diag(rack, cts, &diag, &tv);
14255 }
14256 
14257 static int
14258 rack_init_outstanding(struct tcpcb *tp, struct tcp_rack *rack, uint32_t us_cts, void *ptr)
14259 {
14260 	struct rack_sendmap *rsm, *ersm;
14261 	int insret __diagused;
14262 	/*
14263 	 * When initing outstanding, we must be quite careful
14264 	 * to not refer to tp->t_fb_ptr. This has the old rack
14265 	 * pointer in it, not the "new" one (when we are doing
14266 	 * a stack switch).
14267 	 */
14268 
14269 
14270 	if (tp->t_fb->tfb_chg_query == NULL) {
14271 		/* Create a send map for the current outstanding data */
14272 
14273 		rsm = rack_alloc(rack);
14274 		if (rsm == NULL) {
14275 			uma_zfree(rack_pcb_zone, ptr);
14276 			return (ENOMEM);
14277 		}
14278 		rsm->r_no_rtt_allowed = 1;
14279 		rsm->r_tim_lastsent[0] = rack_to_usec_ts(&rack->r_ctl.act_rcv_time);
14280 		rsm->r_rtr_cnt = 1;
14281 		rsm->r_rtr_bytes = 0;
14282 		if (tp->t_flags & TF_SENTFIN)
14283 			rsm->r_flags |= RACK_HAS_FIN;
14284 		rsm->r_end = tp->snd_max;
14285 		if (tp->snd_una == tp->iss) {
14286 			/* The data space is one beyond snd_una */
14287 			rsm->r_flags |= RACK_HAS_SYN;
14288 			rsm->r_start = tp->iss;
14289 			rsm->r_end = rsm->r_start + (tp->snd_max - tp->snd_una);
14290 		} else
14291 			rsm->r_start = tp->snd_una;
14292 		rsm->r_dupack = 0;
14293 		if (rack->rc_inp->inp_socket->so_snd.sb_mb != NULL) {
14294 			rsm->m = sbsndmbuf(&rack->rc_inp->inp_socket->so_snd, 0, &rsm->soff);
14295 			if (rsm->m) {
14296 				rsm->orig_m_len = rsm->m->m_len;
14297 				rsm->orig_t_space = M_TRAILINGROOM(rsm->m);
14298 			} else {
14299 				rsm->orig_m_len = 0;
14300 				rsm->orig_t_space = 0;
14301 			}
14302 		} else {
14303 			/*
14304 			 * This can happen if we have a stand-alone FIN or
14305 			 *  SYN.
14306 			 */
14307 			rsm->m = NULL;
14308 			rsm->orig_m_len = 0;
14309 			rsm->orig_t_space = 0;
14310 			rsm->soff = 0;
14311 		}
14312 #ifdef INVARIANTS
14313 		if ((insret = tqhash_insert(rack->r_ctl.tqh, rsm)) != 0) {
14314 			panic("Insert in tailq_hash fails ret:%d rack:%p rsm:%p",
14315 			      insret, rack, rsm);
14316 		}
14317 #else
14318 		(void)tqhash_insert(rack->r_ctl.tqh, rsm);
14319 #endif
14320 		TAILQ_INSERT_TAIL(&rack->r_ctl.rc_tmap, rsm, r_tnext);
14321 		rsm->r_in_tmap = 1;
14322 	} else {
14323 		/* We have a query mechanism, lets use it */
14324 		struct tcp_query_resp qr;
14325 		int i;
14326 		tcp_seq at;
14327 
14328 		at = tp->snd_una;
14329 		while (at != tp->snd_max) {
14330 			memset(&qr, 0, sizeof(qr));
14331 			qr.req = TCP_QUERY_SENDMAP;
14332 			qr.req_param = at;
14333 			if ((*tp->t_fb->tfb_chg_query)(tp, &qr) == 0)
14334 				break;
14335 			/* Move forward */
14336 			at = qr.sendmap_end;
14337 			/* Now lets build the entry for this one */
14338 			rsm = rack_alloc(rack);
14339 			if (rsm == NULL) {
14340 				uma_zfree(rack_pcb_zone, ptr);
14341 				return (ENOMEM);
14342 			}
14343 			memset(rsm, 0, sizeof(struct rack_sendmap));
14344 			/* Now configure the rsm and insert it */
14345 			rsm->r_dupack = qr.sendmap_dupacks;
14346 			rsm->r_start = qr.sendmap_start;
14347 			rsm->r_end = qr.sendmap_end;
14348 			if (qr.sendmap_fas)
14349 				rsm->r_fas = qr.sendmap_end;
14350 			else
14351 				rsm->r_fas = rsm->r_start - tp->snd_una;
14352 			/*
14353 			 * We have carefully aligned the bits
14354 			 * so that all we have to do is copy over
14355 			 * the bits with the mask.
14356 			 */
14357 			rsm->r_flags = qr.sendmap_flags & SNDMAP_MASK;
14358 			rsm->r_rtr_bytes = qr.sendmap_r_rtr_bytes;
14359 			rsm->r_rtr_cnt = qr.sendmap_send_cnt;
14360 			rsm->r_ack_arrival = qr.sendmap_ack_arrival;
14361 			for (i=0 ; i<rsm->r_rtr_cnt; i++)
14362 				rsm->r_tim_lastsent[i]	= qr.sendmap_time[i];
14363 			rsm->m = sbsndmbuf(&rack->rc_inp->inp_socket->so_snd,
14364 					   (rsm->r_start - tp->snd_una), &rsm->soff);
14365 			if (rsm->m) {
14366 				rsm->orig_m_len = rsm->m->m_len;
14367 				rsm->orig_t_space = M_TRAILINGROOM(rsm->m);
14368 			} else {
14369 				rsm->orig_m_len = 0;
14370 				rsm->orig_t_space = 0;
14371 			}
14372 #ifdef INVARIANTS
14373 			if ((insret = tqhash_insert(rack->r_ctl.tqh, rsm)) != 0) {
14374 				panic("Insert in tailq_hash fails ret:%d rack:%p rsm:%p",
14375 				      insret, rack, rsm);
14376 			}
14377 #else
14378 			(void)tqhash_insert(rack->r_ctl.tqh, rsm);
14379 #endif
14380 			if ((rsm->r_flags & RACK_ACKED) == 0)  {
14381 				TAILQ_FOREACH(ersm, &rack->r_ctl.rc_tmap, r_tnext) {
14382 					if (ersm->r_tim_lastsent[(ersm->r_rtr_cnt-1)] >
14383 					    rsm->r_tim_lastsent[(rsm->r_rtr_cnt-1)]) {
14384 						/*
14385 						 * If the existing ersm was sent at
14386 						 * a later time than the new one, then
14387 						 * the new one should appear ahead of this
14388 						 * ersm.
14389 						 */
14390 						rsm->r_in_tmap = 1;
14391 						TAILQ_INSERT_BEFORE(ersm, rsm, r_tnext);
14392 						break;
14393 					}
14394 				}
14395 				if (rsm->r_in_tmap == 0) {
14396 					/*
14397 					 * Not found so shove it on the tail.
14398 					 */
14399 					TAILQ_INSERT_TAIL(&rack->r_ctl.rc_tmap, rsm, r_tnext);
14400 					rsm->r_in_tmap = 1;
14401 				}
14402  			} else {
14403 				if ((rack->r_ctl.rc_sacklast == NULL) ||
14404 				    (SEQ_GT(rsm->r_end, rack->r_ctl.rc_sacklast->r_end))) {
14405 					rack->r_ctl.rc_sacklast = rsm;
14406 				}
14407 			}
14408 			rack_log_chg_info(tp, rack, 3,
14409 					  rsm->r_start,
14410 					  rsm->r_end,
14411 					  rsm->r_flags);
14412 		}
14413 	}
14414 	return (0);
14415 }
14416 
14417 
14418 static int32_t
14419 rack_init(struct tcpcb *tp, void **ptr)
14420 {
14421 	struct inpcb *inp = tptoinpcb(tp);
14422 	struct tcp_rack *rack = NULL;
14423 	uint32_t iwin, snt, us_cts;
14424 	size_t sz;
14425 	int err, no_query;
14426 
14427 	tcp_hpts_init(tp);
14428 
14429 	/*
14430 	 * First are we the initial or are we a switched stack?
14431 	 * If we are initing via tcp_newtcppcb the ptr passed
14432 	 * will be tp->t_fb_ptr. If its a stack switch that
14433 	 * has a previous stack we can query it will be a local
14434 	 * var that will in the end be set into t_fb_ptr.
14435 	 */
14436 	if (ptr == &tp->t_fb_ptr)
14437 		no_query = 1;
14438 	else
14439 		no_query = 0;
14440 	*ptr = uma_zalloc(rack_pcb_zone, M_NOWAIT);
14441 	if (*ptr == NULL) {
14442 		/*
14443 		 * We need to allocate memory but cant. The INP and INP_INFO
14444 		 * locks and they are recursive (happens during setup. So a
14445 		 * scheme to drop the locks fails :(
14446 		 *
14447 		 */
14448 		return(ENOMEM);
14449 	}
14450 	memset(*ptr, 0, sizeof(struct tcp_rack));
14451 	rack = (struct tcp_rack *)*ptr;
14452 	rack->r_ctl.tqh = malloc(sizeof(struct tailq_hash), M_TCPFSB, M_NOWAIT);
14453 	if (rack->r_ctl.tqh == NULL) {
14454 		uma_zfree(rack_pcb_zone, rack);
14455 		return(ENOMEM);
14456 	}
14457 	tqhash_init(rack->r_ctl.tqh);
14458 	TAILQ_INIT(&rack->r_ctl.rc_free);
14459 	TAILQ_INIT(&rack->r_ctl.rc_tmap);
14460 	rack->rc_tp = tp;
14461 	rack->rc_inp = inp;
14462 	/* Set the flag */
14463 	rack->r_is_v6 = (inp->inp_vflag & INP_IPV6) != 0;
14464 	/* Probably not needed but lets be sure */
14465 	rack_clear_rate_sample(rack);
14466 	/*
14467 	 * Save off the default values, socket options will poke
14468 	 * at these if pacing is not on or we have not yet
14469 	 * reached where pacing is on (gp_ready/fixed enabled).
14470 	 * When they get set into the CC module (when gp_ready
14471 	 * is enabled or we enable fixed) then we will set these
14472 	 * values into the CC and place in here the old values
14473 	 * so we have a restoral. Then we will set the flag
14474 	 * rc_pacing_cc_set. That way whenever we turn off pacing
14475 	 * or switch off this stack, we will know to go restore
14476 	 * the saved values.
14477 	 *
14478 	 * We specifically put into the beta the ecn value for pacing.
14479 	 */
14480 	rack->rc_new_rnd_needed = 1;
14481 	rack->r_ctl.rc_split_limit = V_tcp_map_split_limit;
14482 	/* We want abe like behavior as well */
14483 
14484 	rack->r_ctl.rc_reorder_fade = rack_reorder_fade;
14485 	rack->rc_allow_data_af_clo = rack_ignore_data_after_close;
14486 	rack->r_ctl.rc_tlp_threshold = rack_tlp_thresh;
14487 	if (rack_fill_cw_state)
14488 		rack->rc_pace_to_cwnd = 1;
14489 	if (rack_pacing_min_seg)
14490 		rack->r_ctl.rc_user_set_min_segs = rack_pacing_min_seg;
14491 	if (use_rack_rr)
14492 		rack->use_rack_rr = 1;
14493 	if (rack_dnd_default) {
14494 		rack->rc_pace_dnd = 1;
14495 	}
14496 	if (V_tcp_delack_enabled)
14497 		tp->t_delayed_ack = 1;
14498 	else
14499 		tp->t_delayed_ack = 0;
14500 #ifdef TCP_ACCOUNTING
14501 	if (rack_tcp_accounting) {
14502 		tp->t_flags2 |= TF2_TCP_ACCOUNTING;
14503 	}
14504 #endif
14505 	rack->r_ctl.pcm_i.cnt_alloc = RACK_DEFAULT_PCM_ARRAY;
14506 	sz = (sizeof(struct rack_pcm_stats) * rack->r_ctl.pcm_i.cnt_alloc);
14507 	rack->r_ctl.pcm_s = malloc(sz,M_TCPPCM, M_NOWAIT);
14508 	if (rack->r_ctl.pcm_s == NULL) {
14509 		rack->r_ctl.pcm_i.cnt_alloc = 0;
14510 	}
14511 	rack->r_ctl.rack_per_upper_bound_ss = (uint8_t)rack_per_upper_bound_ss;
14512 	rack->r_ctl.rack_per_upper_bound_ca = (uint8_t)rack_per_upper_bound_ca;
14513 	if (rack_enable_shared_cwnd)
14514 		rack->rack_enable_scwnd = 1;
14515 	rack->r_ctl.pace_len_divisor = rack_default_pacing_divisor;
14516 	rack->rc_user_set_max_segs = rack_hptsi_segments;
14517 	rack->r_ctl.max_reduction = rack_max_reduce;
14518 	rack->rc_force_max_seg = 0;
14519 	TAILQ_INIT(&rack->r_ctl.opt_list);
14520 	rack->r_ctl.rc_saved_beta = V_newreno_beta_ecn;
14521 	rack->r_ctl.rc_saved_beta_ecn = V_newreno_beta_ecn;
14522 	if (rack_hibeta_setting) {
14523 		rack->rack_hibeta = 1;
14524 		if ((rack_hibeta_setting >= 50) &&
14525 		    (rack_hibeta_setting <= 100)) {
14526 			rack->r_ctl.rc_saved_beta = rack_hibeta_setting;
14527 			rack->r_ctl.saved_hibeta = rack_hibeta_setting;
14528 		}
14529 	} else {
14530 		rack->r_ctl.saved_hibeta = 50;
14531 	}
14532 	/*
14533 	 * We initialize to all ones so we never match 0
14534 	 * just in case the client sends in 0, it hopefully
14535 	 * will never have all 1's in ms :-)
14536 	 */
14537 	rack->r_ctl.last_tm_mark = 0xffffffffffffffff;
14538 	rack->r_ctl.rc_reorder_shift = rack_reorder_thresh;
14539 	rack->r_ctl.rc_pkt_delay = rack_pkt_delay;
14540 	rack->r_ctl.rc_tlp_cwnd_reduce = rack_lower_cwnd_at_tlp;
14541 	rack->r_ctl.rc_lowest_us_rtt = 0xffffffff;
14542 	rack->r_ctl.rc_highest_us_rtt = 0;
14543 	rack->r_ctl.bw_rate_cap = rack_bw_rate_cap;
14544 	rack->pcm_enabled = rack_pcm_is_enabled;
14545 	if (rack_fillcw_bw_cap)
14546 		rack->r_ctl.fillcw_cap = rack_fillcw_bw_cap;
14547 	rack->r_ctl.timer_slop = TICKS_2_USEC(tcp_rexmit_slop);
14548 	if (rack_use_cmp_acks)
14549 		rack->r_use_cmp_ack = 1;
14550 	if (rack_disable_prr)
14551 		rack->rack_no_prr = 1;
14552 	if (rack_gp_no_rec_chg)
14553 		rack->rc_gp_no_rec_chg = 1;
14554 	if (rack_pace_every_seg && tcp_can_enable_pacing()) {
14555 		rack->r_ctl.pacing_method |= RACK_REG_PACING;
14556 		rack->rc_always_pace = 1;
14557 		if (rack->rack_hibeta)
14558 			rack_set_cc_pacing(rack);
14559 	} else
14560 		rack->rc_always_pace = 0;
14561 	if (rack_enable_mqueue_for_nonpaced || rack->r_use_cmp_ack)
14562 		rack->r_mbuf_queue = 1;
14563 	else
14564 		rack->r_mbuf_queue = 0;
14565 	rack_set_pace_segments(tp, rack, __LINE__, NULL);
14566 	if (rack_limits_scwnd)
14567 		rack->r_limit_scw = 1;
14568 	else
14569 		rack->r_limit_scw = 0;
14570 	rack_init_retransmit_value(rack, rack_rxt_controls);
14571 	rack->rc_labc = V_tcp_abc_l_var;
14572 	if (rack_honors_hpts_min_to)
14573 		rack->r_use_hpts_min = 1;
14574 	if (tp->snd_una != 0) {
14575 		rack->rc_sendvars_notset = 0;
14576 		/*
14577 		 * Make sure any TCP timers are not running.
14578 		 */
14579 		tcp_timer_stop(tp);
14580 	} else {
14581 		/*
14582 		 * Server side, we are called from the
14583 		 * syn-cache. This means none of the
14584 		 * snd_una/max are set yet so we have
14585 		 * to defer this until the first send.
14586 		 */
14587 		rack->rc_sendvars_notset = 1;
14588 	}
14589 
14590 	rack->r_ctl.rc_rate_sample_method = rack_rate_sample_method;
14591 	rack->rack_tlp_threshold_use = rack_tlp_threshold_use;
14592 	rack->r_ctl.rc_prr_sendalot = rack_send_a_lot_in_prr;
14593 	rack->r_ctl.rc_min_to = rack_min_to;
14594 	microuptime(&rack->r_ctl.act_rcv_time);
14595 	rack->r_ctl.rack_per_of_gp_ss = rack_per_of_gp_ss;
14596 	if (rack_hw_up_only)
14597 		rack->r_up_only = 1;
14598 	if (rack_do_dyn_mul) {
14599 		/* When dynamic adjustment is on CA needs to start at 100% */
14600 		rack->rc_gp_dyn_mul = 1;
14601 		if (rack_do_dyn_mul >= 100)
14602 			rack->r_ctl.rack_per_of_gp_ca = rack_do_dyn_mul;
14603 	} else
14604 		rack->r_ctl.rack_per_of_gp_ca = rack_per_of_gp_ca;
14605 	rack->r_ctl.rack_per_of_gp_rec = rack_per_of_gp_rec;
14606 	if (rack_timely_off) {
14607 		rack->rc_skip_timely = 1;
14608 	}
14609 	if (rack->rc_skip_timely) {
14610 		rack->r_ctl.rack_per_of_gp_rec = 90;
14611 		rack->r_ctl.rack_per_of_gp_ca = 100;
14612 		rack->r_ctl.rack_per_of_gp_ss = 250;
14613 	}
14614 	rack->r_ctl.rack_per_of_gp_probertt = rack_per_of_gp_probertt;
14615 	rack->r_ctl.rc_tlp_rxt_last_time = tcp_tv_to_msec(&rack->r_ctl.act_rcv_time);
14616 	rack->r_ctl.last_rcv_tstmp_for_rtt = tcp_tv_to_msec(&rack->r_ctl.act_rcv_time);
14617 
14618 	setup_time_filter_small(&rack->r_ctl.rc_gp_min_rtt, FILTER_TYPE_MIN,
14619 				rack_probertt_filter_life);
14620 	us_cts = tcp_tv_to_usec(&rack->r_ctl.act_rcv_time);
14621 	rack->r_ctl.rc_lower_rtt_us_cts = us_cts;
14622 	rack->r_ctl.rc_time_of_last_probertt = us_cts;
14623 	rack->r_ctl.rc_went_idle_time = us_cts;
14624 	rack->r_ctl.rc_time_probertt_starts = 0;
14625 
14626 	rack->r_ctl.gp_rnd_thresh = rack_rnd_cnt_req & 0xff;
14627 	if (rack_rnd_cnt_req  & 0x10000)
14628 		rack->r_ctl.gate_to_fs = 1;
14629 	rack->r_ctl.gp_gain_req = rack_gp_gain_req;
14630 	if ((rack_rnd_cnt_req & 0x100) > 0) {
14631 
14632 	}
14633 	if (rack_dsack_std_based & 0x1) {
14634 		/* Basically this means all rack timers are at least (srtt + 1/4 srtt) */
14635 		rack->rc_rack_tmr_std_based = 1;
14636 	}
14637 	if (rack_dsack_std_based & 0x2) {
14638 		/* Basically this means  rack timers are extended based on dsack by up to (2 * srtt) */
14639 		rack->rc_rack_use_dsack = 1;
14640 	}
14641 	/* We require at least one measurement, even if the sysctl is 0 */
14642 	if (rack_req_measurements)
14643 		rack->r_ctl.req_measurements = rack_req_measurements;
14644 	else
14645 		rack->r_ctl.req_measurements = 1;
14646 	if (rack_enable_hw_pacing)
14647 		rack->rack_hdw_pace_ena = 1;
14648 	if (rack_hw_rate_caps)
14649 		rack->r_rack_hw_rate_caps = 1;
14650 	if (rack_non_rxt_use_cr)
14651 		rack->rack_rec_nonrxt_use_cr = 1;
14652 	/* Lets setup the fsb block */
14653 	err = rack_init_fsb(tp, rack);
14654 	if (err) {
14655 		uma_zfree(rack_pcb_zone, *ptr);
14656 		*ptr = NULL;
14657 		return (err);
14658 	}
14659 	if (rack_do_hystart) {
14660 		tp->t_ccv.flags |= CCF_HYSTART_ALLOWED;
14661 		if (rack_do_hystart > 1)
14662 			tp->t_ccv.flags |= CCF_HYSTART_CAN_SH_CWND;
14663 		if (rack_do_hystart > 2)
14664 			tp->t_ccv.flags |= CCF_HYSTART_CONS_SSTH;
14665 	}
14666 	/* Log what we will do with queries */
14667 	rack_log_chg_info(tp, rack, 7,
14668 			  no_query, 0, 0);
14669 	if (rack_def_profile)
14670 		rack_set_profile(rack, rack_def_profile);
14671 	/* Cancel the GP measurement in progress */
14672 	tp->t_flags &= ~TF_GPUTINPROG;
14673 	if ((tp->t_state != TCPS_CLOSED) &&
14674 	    (tp->t_state != TCPS_TIME_WAIT)) {
14675 		/*
14676 		 * We are already open, we may
14677 		 * need to adjust a few things.
14678 		 */
14679 		if (SEQ_GT(tp->snd_max, tp->iss))
14680 			snt = tp->snd_max - tp->iss;
14681 		else
14682 			snt = 0;
14683 		iwin = rc_init_window(rack);
14684 		if ((snt < iwin) &&
14685 		    (no_query == 1)) {
14686 			/* We are not past the initial window
14687 			 * on the first init (i.e. a stack switch
14688 			 * has not yet occured) so we need to make
14689 			 * sure cwnd and ssthresh is correct.
14690 			 */
14691 			if (tp->snd_cwnd < iwin)
14692 				tp->snd_cwnd = iwin;
14693 			/*
14694 			 * If we are within the initial window
14695 			 * we want ssthresh to be unlimited. Setting
14696 			 * it to the rwnd (which the default stack does
14697 			 * and older racks) is not really a good idea
14698 			 * since we want to be in SS and grow both the
14699 			 * cwnd and the rwnd (via dynamic rwnd growth). If
14700 			 * we set it to the rwnd then as the peer grows its
14701 			 * rwnd we will be stuck in CA and never hit SS.
14702 			 *
14703 			 * Its far better to raise it up high (this takes the
14704 			 * risk that there as been a loss already, probably
14705 			 * we should have an indicator in all stacks of loss
14706 			 * but we don't), but considering the normal use this
14707 			 * is a risk worth taking. The consequences of not
14708 			 * hitting SS are far worse than going one more time
14709 			 * into it early on (before we have sent even a IW).
14710 			 * It is highly unlikely that we will have had a loss
14711 			 * before getting the IW out.
14712 			 */
14713 			tp->snd_ssthresh = 0xffffffff;
14714 		}
14715 		/*
14716 		 * Any init based on sequence numbers
14717 		 * should be done in the deferred init path
14718 		 * since we can be CLOSED and not have them
14719 		 * inited when rack_init() is called. We
14720 		 * are not closed so lets call it.
14721 		 */
14722 		rack_deferred_init(tp, rack);
14723 	}
14724 	if ((tp->t_state != TCPS_CLOSED) &&
14725 	    (tp->t_state != TCPS_TIME_WAIT) &&
14726 	    (no_query == 0) &&
14727 	    (tp->snd_una != tp->snd_max))  {
14728 		err = rack_init_outstanding(tp, rack, us_cts, *ptr);
14729 		if (err) {
14730 			*ptr = NULL;
14731 			return(err);
14732 		}
14733 	}
14734 	rack_stop_all_timers(tp, rack);
14735 	/* Setup all the t_flags2 */
14736 	if  (rack->r_mbuf_queue || rack->rc_always_pace || rack->r_use_cmp_ack)
14737 		tp->t_flags2 |= TF2_SUPPORTS_MBUFQ;
14738 	else
14739 		tp->t_flags2 &= ~TF2_SUPPORTS_MBUFQ;
14740 	if (rack->r_use_cmp_ack && TCPS_HAVEESTABLISHED(tp->t_state))
14741 		tp->t_flags2 |= TF2_MBUF_ACKCMP;
14742 	/*
14743 	 * Timers in Rack are kept in microseconds so lets
14744 	 * convert any initial incoming variables
14745 	 * from ticks into usecs. Note that we
14746 	 * also change the values of t_srtt and t_rttvar, if
14747 	 * they are non-zero. They are kept with a 5
14748 	 * bit decimal so we have to carefully convert
14749 	 * these to get the full precision.
14750 	 */
14751 	rack_convert_rtts(tp);
14752 	rack_log_hystart_event(rack, rack->r_ctl.roundends, 20);
14753 	if ((tptoinpcb(tp)->inp_flags & INP_DROPPED) == 0) {
14754 		/* We do not start any timers on DROPPED connections */
14755 		if (tp->t_fb->tfb_chg_query == NULL) {
14756 			rack_start_hpts_timer(rack, tp, tcp_get_usecs(NULL), 0, 0, 0);
14757 		} else {
14758 			struct tcp_query_resp qr;
14759 			int ret;
14760 
14761 			memset(&qr, 0, sizeof(qr));
14762 
14763 			/* Get the misc time stamps and such for rack */
14764 			qr.req = TCP_QUERY_RACK_TIMES;
14765 			ret = (*tp->t_fb->tfb_chg_query)(tp, &qr);
14766 			if (ret == 1) {
14767 				rack->r_ctl.rc_reorder_ts = qr.rack_reorder_ts;
14768 				rack->r_ctl.num_dsack  = qr.rack_num_dsacks;
14769 				rack->r_ctl.rc_tlp_rxt_last_time = qr.rack_rxt_last_time;
14770 				rack->r_ctl.rc_rack_min_rtt = qr.rack_min_rtt;
14771 				rack->rc_rack_rtt = qr.rack_rtt;
14772 				rack->r_ctl.rc_rack_tmit_time = qr.rack_tmit_time;
14773 				rack->r_ctl.rc_sacked = qr.rack_sacked;
14774 				rack->r_ctl.rc_holes_rxt = qr.rack_holes_rxt;
14775 				rack->r_ctl.rc_prr_delivered = qr.rack_prr_delivered;
14776 				rack->r_ctl.rc_prr_recovery_fs = qr.rack_prr_recovery_fs;
14777 				rack->r_ctl.rc_prr_sndcnt = qr.rack_prr_sndcnt;
14778 				rack->r_ctl.rc_prr_out = qr.rack_prr_out;
14779 				if (qr.rack_tlp_out) {
14780 					rack->rc_tlp_in_progress = 1;
14781 					rack->r_ctl.rc_tlp_cnt_out = qr.rack_tlp_cnt_out;
14782 				} else {
14783 					rack->rc_tlp_in_progress = 0;
14784 					rack->r_ctl.rc_tlp_cnt_out = 0;
14785 				}
14786 				if (qr.rack_srtt_measured)
14787 					rack->rc_srtt_measure_made = 1;
14788 				if (qr.rack_in_persist == 1) {
14789 					rack->r_ctl.rc_went_idle_time = qr.rack_time_went_idle;
14790 #ifdef NETFLIX_SHARED_CWND
14791 					if (rack->r_ctl.rc_scw) {
14792 						tcp_shared_cwnd_idle(rack->r_ctl.rc_scw, rack->r_ctl.rc_scw_index);
14793 						rack->rack_scwnd_is_idle = 1;
14794 					}
14795 #endif
14796 					rack->r_ctl.persist_lost_ends = 0;
14797 					rack->probe_not_answered = 0;
14798 					rack->forced_ack = 0;
14799 					tp->t_rxtshift = 0;
14800 					rack->rc_in_persist = 1;
14801 					RACK_TCPT_RANGESET(tp->t_rxtcur, RACK_REXMTVAL(tp),
14802 							   rack_rto_min, rack_rto_max, rack->r_ctl.timer_slop);
14803 				}
14804 				if (qr.rack_wanted_output)
14805 					rack->r_wanted_output = 1;
14806 				rack_log_chg_info(tp, rack, 6,
14807 						  qr.rack_min_rtt,
14808 						  qr.rack_rtt,
14809 						  qr.rack_reorder_ts);
14810 			}
14811 			/* Get the old stack timers */
14812 			qr.req_param = 0;
14813 			qr.req = TCP_QUERY_TIMERS_UP;
14814 			ret = (*tp->t_fb->tfb_chg_query)(tp, &qr);
14815 			if (ret) {
14816 				/*
14817 				 * non-zero return means we have a timer('s)
14818 				 * to start. Zero means no timer (no keepalive
14819 				 * I suppose).
14820 				 */
14821 				uint32_t tov = 0;
14822 
14823 				rack->r_ctl.rc_hpts_flags = qr.timer_hpts_flags;
14824 				if (qr.timer_hpts_flags & PACE_PKT_OUTPUT) {
14825 					rack->r_ctl.rc_last_output_to = qr.timer_pacing_to;
14826 					if (TSTMP_GT(qr.timer_pacing_to, us_cts))
14827 						tov = qr.timer_pacing_to - us_cts;
14828 					else
14829 						tov = HPTS_USECS_PER_SLOT;
14830 				}
14831 				if (qr.timer_hpts_flags & PACE_TMR_MASK) {
14832 					rack->r_ctl.rc_timer_exp = qr.timer_timer_exp;
14833 					if (tov == 0) {
14834 						if (TSTMP_GT(qr.timer_timer_exp, us_cts))
14835 							tov = qr.timer_timer_exp - us_cts;
14836 						else
14837 							tov = HPTS_USECS_PER_SLOT;
14838 					}
14839 				}
14840 				rack_log_chg_info(tp, rack, 4,
14841 						  rack->r_ctl.rc_hpts_flags,
14842 						  rack->r_ctl.rc_last_output_to,
14843 						  rack->r_ctl.rc_timer_exp);
14844 				if (tov) {
14845 					struct hpts_diag diag;
14846 
14847 					tcp_hpts_insert(tp, tov, &diag);
14848 					rack_log_hpts_diag(rack, us_cts, &diag, &rack->r_ctl.act_rcv_time);
14849 				}
14850 			}
14851 		}
14852 		rack_log_rtt_shrinks(rack,  us_cts,  tp->t_rxtcur,
14853 				     __LINE__, RACK_RTTS_INIT);
14854 	}
14855 	return (0);
14856 }
14857 
14858 static int
14859 rack_handoff_ok(struct tcpcb *tp)
14860 {
14861 	if ((tp->t_state == TCPS_CLOSED) ||
14862 	    (tp->t_state == TCPS_LISTEN)) {
14863 		/* Sure no problem though it may not stick */
14864 		return (0);
14865 	}
14866 	if ((tp->t_state == TCPS_SYN_SENT) ||
14867 	    (tp->t_state == TCPS_SYN_RECEIVED)) {
14868 		/*
14869 		 * We really don't know if you support sack,
14870 		 * you have to get to ESTAB or beyond to tell.
14871 		 */
14872 		return (EAGAIN);
14873 	}
14874 	if ((tp->t_flags & TF_SENTFIN) && ((tp->snd_max - tp->snd_una) > 1)) {
14875 		/*
14876 		 * Rack will only send a FIN after all data is acknowledged.
14877 		 * So in this case we have more data outstanding. We can't
14878 		 * switch stacks until either all data and only the FIN
14879 		 * is left (in which case rack_init() now knows how
14880 		 * to deal with that) <or> all is acknowledged and we
14881 		 * are only left with incoming data, though why you
14882 		 * would want to switch to rack after all data is acknowledged
14883 		 * I have no idea (rrs)!
14884 		 */
14885 		return (EAGAIN);
14886 	}
14887 	if ((tp->t_flags & TF_SACK_PERMIT) || rack_sack_not_required){
14888 		return (0);
14889 	}
14890 	/*
14891 	 * If we reach here we don't do SACK on this connection so we can
14892 	 * never do rack.
14893 	 */
14894 	return (EINVAL);
14895 }
14896 
14897 static void
14898 rack_fini(struct tcpcb *tp, int32_t tcb_is_purged)
14899 {
14900 
14901 	if (tp->t_fb_ptr) {
14902 		uint32_t cnt_free = 0;
14903 		struct tcp_rack *rack;
14904 		struct rack_sendmap *rsm;
14905 
14906 		tcp_handle_orphaned_packets(tp);
14907 		tp->t_flags &= ~TF_FORCEDATA;
14908 		rack = (struct tcp_rack *)tp->t_fb_ptr;
14909 		rack_log_pacing_delay_calc(rack,
14910 					   0,
14911 					   0,
14912 					   0,
14913 					   rack_get_gp_est(rack), /* delRate */
14914 					   rack_get_lt_bw(rack), /* rttProp */
14915 					   20, __LINE__, NULL, 0);
14916 #ifdef NETFLIX_SHARED_CWND
14917 		if (rack->r_ctl.rc_scw) {
14918 			uint32_t limit;
14919 
14920 			if (rack->r_limit_scw)
14921 				limit = max(1, rack->r_ctl.rc_lowest_us_rtt);
14922 			else
14923 				limit = 0;
14924 			tcp_shared_cwnd_free_full(tp, rack->r_ctl.rc_scw,
14925 						  rack->r_ctl.rc_scw_index,
14926 						  limit);
14927 			rack->r_ctl.rc_scw = NULL;
14928 		}
14929 #endif
14930 		if (rack->r_ctl.fsb.tcp_ip_hdr) {
14931 			free(rack->r_ctl.fsb.tcp_ip_hdr, M_TCPFSB);
14932 			rack->r_ctl.fsb.tcp_ip_hdr = NULL;
14933 			rack->r_ctl.fsb.th = NULL;
14934 		}
14935 		if (rack->rc_always_pace == 1) {
14936 			rack_remove_pacing(rack);
14937 		}
14938 		/* Clean up any options if they were not applied */
14939 		while (!TAILQ_EMPTY(&rack->r_ctl.opt_list)) {
14940 			struct deferred_opt_list *dol;
14941 
14942 			dol = TAILQ_FIRST(&rack->r_ctl.opt_list);
14943 			TAILQ_REMOVE(&rack->r_ctl.opt_list, dol, next);
14944 			free(dol, M_TCPDO);
14945 		}
14946 		/* rack does not use force data but other stacks may clear it */
14947 		if (rack->r_ctl.crte != NULL) {
14948 			tcp_rel_pacing_rate(rack->r_ctl.crte, tp);
14949 			rack->rack_hdrw_pacing = 0;
14950 			rack->r_ctl.crte = NULL;
14951 		}
14952 #ifdef TCP_BLACKBOX
14953 		tcp_log_flowend(tp);
14954 #endif
14955 		/*
14956 		 * Lets take a different approach to purging just
14957 		 * get each one and free it like a cum-ack would and
14958 		 * not use a foreach loop.
14959 		 */
14960 		rsm = tqhash_min(rack->r_ctl.tqh);
14961 		while (rsm) {
14962 			tqhash_remove(rack->r_ctl.tqh, rsm, REMOVE_TYPE_CUMACK);
14963 			rack->r_ctl.rc_num_maps_alloced--;
14964 			uma_zfree(rack_zone, rsm);
14965 			rsm = tqhash_min(rack->r_ctl.tqh);
14966 		}
14967 		rsm = TAILQ_FIRST(&rack->r_ctl.rc_free);
14968 		while (rsm) {
14969 			TAILQ_REMOVE(&rack->r_ctl.rc_free, rsm, r_tnext);
14970 			rack->r_ctl.rc_num_maps_alloced--;
14971 			rack->rc_free_cnt--;
14972 			cnt_free++;
14973 			uma_zfree(rack_zone, rsm);
14974 			rsm = TAILQ_FIRST(&rack->r_ctl.rc_free);
14975 		}
14976 		if (rack->r_ctl.pcm_s != NULL) {
14977 			free(rack->r_ctl.pcm_s, M_TCPPCM);
14978 			rack->r_ctl.pcm_s = NULL;
14979 			rack->r_ctl.pcm_i.cnt_alloc = 0;
14980 			rack->r_ctl.pcm_i.cnt = 0;
14981 		}
14982 		if ((rack->r_ctl.rc_num_maps_alloced > 0) &&
14983 		    (tcp_bblogging_on(tp))) {
14984 			union tcp_log_stackspecific log;
14985 			struct timeval tv;
14986 
14987 			memset(&log, 0, sizeof(log));
14988 			log.u_bbr.flex8 = 10;
14989 			log.u_bbr.flex1 = rack->r_ctl.rc_num_maps_alloced;
14990 			log.u_bbr.flex2 = rack->rc_free_cnt;
14991 			log.u_bbr.flex3 = cnt_free;
14992 			log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
14993 			rsm = tqhash_min(rack->r_ctl.tqh);
14994 			log.u_bbr.delRate = (uintptr_t)rsm;
14995 			rsm = TAILQ_FIRST(&rack->r_ctl.rc_free);
14996 			log.u_bbr.cur_del_rate = (uintptr_t)rsm;
14997 			log.u_bbr.timeStamp = tcp_get_usecs(&tv);
14998 			log.u_bbr.pkt_epoch = __LINE__;
14999 			(void)tcp_log_event(tp, NULL, NULL, NULL, TCP_LOG_OUT, ERRNO_UNK,
15000 					     0, &log, false, NULL, NULL, 0, &tv);
15001 		}
15002 		KASSERT((rack->r_ctl.rc_num_maps_alloced == 0),
15003 			("rack:%p num_aloc:%u after freeing all?",
15004 			 rack,
15005 			 rack->r_ctl.rc_num_maps_alloced));
15006 		rack->rc_free_cnt = 0;
15007 		free(rack->r_ctl.tqh, M_TCPFSB);
15008 		rack->r_ctl.tqh = NULL;
15009 		uma_zfree(rack_pcb_zone, tp->t_fb_ptr);
15010 		tp->t_fb_ptr = NULL;
15011 	}
15012 	/* Make sure snd_nxt is correctly set */
15013 	tp->snd_nxt = tp->snd_max;
15014 }
15015 
15016 static void
15017 rack_set_state(struct tcpcb *tp, struct tcp_rack *rack)
15018 {
15019 	if ((rack->r_state == TCPS_CLOSED) && (tp->t_state != TCPS_CLOSED)) {
15020 		rack->r_is_v6 = (tptoinpcb(tp)->inp_vflag & INP_IPV6) != 0;
15021 	}
15022 	switch (tp->t_state) {
15023 	case TCPS_SYN_SENT:
15024 		rack->r_state = TCPS_SYN_SENT;
15025 		rack->r_substate = rack_do_syn_sent;
15026 		break;
15027 	case TCPS_SYN_RECEIVED:
15028 		rack->r_state = TCPS_SYN_RECEIVED;
15029 		rack->r_substate = rack_do_syn_recv;
15030 		break;
15031 	case TCPS_ESTABLISHED:
15032 		rack_set_pace_segments(tp, rack, __LINE__, NULL);
15033 		rack->r_state = TCPS_ESTABLISHED;
15034 		rack->r_substate = rack_do_established;
15035 		break;
15036 	case TCPS_CLOSE_WAIT:
15037 		rack->r_state = TCPS_CLOSE_WAIT;
15038 		rack->r_substate = rack_do_close_wait;
15039 		break;
15040 	case TCPS_FIN_WAIT_1:
15041 		rack_set_pace_segments(tp, rack, __LINE__, NULL);
15042 		rack->r_state = TCPS_FIN_WAIT_1;
15043 		rack->r_substate = rack_do_fin_wait_1;
15044 		break;
15045 	case TCPS_CLOSING:
15046 		rack_set_pace_segments(tp, rack, __LINE__, NULL);
15047 		rack->r_state = TCPS_CLOSING;
15048 		rack->r_substate = rack_do_closing;
15049 		break;
15050 	case TCPS_LAST_ACK:
15051 		rack_set_pace_segments(tp, rack, __LINE__, NULL);
15052 		rack->r_state = TCPS_LAST_ACK;
15053 		rack->r_substate = rack_do_lastack;
15054 		break;
15055 	case TCPS_FIN_WAIT_2:
15056 		rack->r_state = TCPS_FIN_WAIT_2;
15057 		rack->r_substate = rack_do_fin_wait_2;
15058 		break;
15059 	case TCPS_LISTEN:
15060 	case TCPS_CLOSED:
15061 	case TCPS_TIME_WAIT:
15062 	default:
15063 		break;
15064 	};
15065 	if (rack->r_use_cmp_ack && TCPS_HAVEESTABLISHED(tp->t_state))
15066 		rack->rc_tp->t_flags2 |= TF2_MBUF_ACKCMP;
15067 
15068 }
15069 
15070 static void
15071 rack_timer_audit(struct tcpcb *tp, struct tcp_rack *rack, struct sockbuf *sb)
15072 {
15073 	/*
15074 	 * We received an ack, and then did not
15075 	 * call send or were bounced out due to the
15076 	 * hpts was running. Now a timer is up as well, is
15077 	 * it the right timer?
15078 	 */
15079 	struct rack_sendmap *rsm;
15080 	int tmr_up;
15081 
15082 	tmr_up = rack->r_ctl.rc_hpts_flags & PACE_TMR_MASK;
15083 	if (tcp_in_hpts(rack->rc_tp) == 0) {
15084 		/*
15085 		 * Ok we probably need some timer up, but no
15086 		 * matter what the mask we are not in hpts. We
15087 		 * may have received an old ack and thus did nothing.
15088 		 */
15089 		rack_timer_cancel(tp, rack, rack->r_ctl.rc_rcvtime, __LINE__);
15090 		rack_start_hpts_timer(rack, tp, tcp_get_usecs(NULL), 0, 0, 0);
15091 		return;
15092 	}
15093 	if (rack->rc_in_persist && (tmr_up == PACE_TMR_PERSIT))
15094 		return;
15095 	rsm = TAILQ_FIRST(&rack->r_ctl.rc_tmap);
15096 	if (((rsm == NULL) || (tp->t_state < TCPS_ESTABLISHED)) &&
15097 	    (tmr_up == PACE_TMR_RXT)) {
15098 		/* Should be an RXT */
15099 		return;
15100 	}
15101 	if (rsm == NULL) {
15102 		/* Nothing outstanding? */
15103 		if (tp->t_flags & TF_DELACK) {
15104 			if (tmr_up == PACE_TMR_DELACK)
15105 				/* We are supposed to have delayed ack up and we do */
15106 				return;
15107 		} else if (((V_tcp_always_keepalive ||
15108 			     rack->rc_inp->inp_socket->so_options & SO_KEEPALIVE) &&
15109 			    (tp->t_state <= TCPS_CLOSING)) &&
15110 			   (tmr_up == PACE_TMR_KEEP) &&
15111 			   (tp->snd_max == tp->snd_una)) {
15112 			/* We should have keep alive up and we do */
15113 			return;
15114 		}
15115 	}
15116 	if (SEQ_GT(tp->snd_max, tp->snd_una) &&
15117 		   ((tmr_up == PACE_TMR_TLP) ||
15118 		    (tmr_up == PACE_TMR_RACK) ||
15119 		    (tmr_up == PACE_TMR_RXT))) {
15120 		/*
15121 		 * Either a Rack, TLP or RXT is fine if  we
15122 		 * have outstanding data.
15123 		 */
15124 		return;
15125 	} else if (tmr_up == PACE_TMR_DELACK) {
15126 		/*
15127 		 * If the delayed ack was going to go off
15128 		 * before the rtx/tlp/rack timer were going to
15129 		 * expire, then that would be the timer in control.
15130 		 * Note we don't check the time here trusting the
15131 		 * code is correct.
15132 		 */
15133 		return;
15134 	}
15135 	/*
15136 	 * Ok the timer originally started is not what we want now.
15137 	 * We will force the hpts to be stopped if any, and restart
15138 	 * with the slot set to what was in the saved slot.
15139 	 */
15140 	if (tcp_in_hpts(rack->rc_tp)) {
15141 		if (rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT) {
15142 			uint32_t us_cts;
15143 
15144 			us_cts = tcp_get_usecs(NULL);
15145 			if (TSTMP_GT(rack->r_ctl.rc_last_output_to, us_cts)) {
15146 				rack->r_early = 1;
15147 				rack->r_ctl.rc_agg_early += (rack->r_ctl.rc_last_output_to - us_cts);
15148 			}
15149 			rack->r_ctl.rc_hpts_flags &= ~PACE_PKT_OUTPUT;
15150 		}
15151 		tcp_hpts_remove(rack->rc_tp);
15152 	}
15153 	rack_timer_cancel(tp, rack, rack->r_ctl.rc_rcvtime, __LINE__);
15154 	rack_start_hpts_timer(rack, tp, tcp_get_usecs(NULL), 0, 0, 0);
15155 }
15156 
15157 
15158 static void
15159 rack_do_win_updates(struct tcpcb *tp, struct tcp_rack *rack, uint32_t tiwin, uint32_t seq, uint32_t ack, uint32_t cts)
15160 {
15161 	if ((SEQ_LT(tp->snd_wl1, seq) ||
15162 	    (tp->snd_wl1 == seq && (SEQ_LT(tp->snd_wl2, ack) ||
15163 	    (tp->snd_wl2 == ack && tiwin > tp->snd_wnd))))) {
15164 		/* keep track of pure window updates */
15165 		if ((tp->snd_wl2 == ack) && (tiwin > tp->snd_wnd))
15166 			KMOD_TCPSTAT_INC(tcps_rcvwinupd);
15167 		tp->snd_wnd = tiwin;
15168 		rack_validate_fo_sendwin_up(tp, rack);
15169 		tp->snd_wl1 = seq;
15170 		tp->snd_wl2 = ack;
15171 		if (tp->snd_wnd > tp->max_sndwnd)
15172 			tp->max_sndwnd = tp->snd_wnd;
15173 	    rack->r_wanted_output = 1;
15174 	} else if ((tp->snd_wl2 == ack) && (tiwin < tp->snd_wnd)) {
15175 		tp->snd_wnd = tiwin;
15176 		rack_validate_fo_sendwin_up(tp, rack);
15177 		tp->snd_wl1 = seq;
15178 		tp->snd_wl2 = ack;
15179 	} else {
15180 		/* Not a valid win update */
15181 		return;
15182 	}
15183 	if (tp->snd_wnd > tp->max_sndwnd)
15184 		tp->max_sndwnd = tp->snd_wnd;
15185 	/* Do we exit persists? */
15186 	if ((rack->rc_in_persist != 0) &&
15187 	    (tp->snd_wnd >= min((rack->r_ctl.rc_high_rwnd/2),
15188 				rack->r_ctl.rc_pace_min_segs))) {
15189 		rack_exit_persist(tp, rack, cts);
15190 	}
15191 	/* Do we enter persists? */
15192 	if ((rack->rc_in_persist == 0) &&
15193 	    (tp->snd_wnd < min((rack->r_ctl.rc_high_rwnd/2), rack->r_ctl.rc_pace_min_segs)) &&
15194 	    TCPS_HAVEESTABLISHED(tp->t_state) &&
15195 	    ((tp->snd_max == tp->snd_una) || rack->rc_has_collapsed) &&
15196 	    sbavail(&tptosocket(tp)->so_snd) &&
15197 	    (sbavail(&tptosocket(tp)->so_snd) > tp->snd_wnd)) {
15198 		/*
15199 		 * Here the rwnd is less than
15200 		 * the pacing size, we are established,
15201 		 * nothing is outstanding, and there is
15202 		 * data to send. Enter persists.
15203 		 */
15204 		rack_enter_persist(tp, rack, rack->r_ctl.rc_rcvtime, ack);
15205 	}
15206 }
15207 
15208 static void
15209 rack_log_input_packet(struct tcpcb *tp, struct tcp_rack *rack, struct tcp_ackent *ae, int ackval, uint32_t high_seq)
15210 {
15211 
15212 	if (tcp_bblogging_on(rack->rc_tp)) {
15213 		struct inpcb *inp = tptoinpcb(tp);
15214 		union tcp_log_stackspecific log;
15215 		struct timeval ltv;
15216 		char tcp_hdr_buf[60];
15217 		struct tcphdr *th;
15218 		struct timespec ts;
15219 		uint32_t orig_snd_una;
15220 		uint8_t xx = 0;
15221 
15222 #ifdef TCP_REQUEST_TRK
15223 		struct tcp_sendfile_track *tcp_req;
15224 
15225 		if (SEQ_GT(ae->ack, tp->snd_una)) {
15226 			tcp_req = tcp_req_find_req_for_seq(tp, (ae->ack-1));
15227 		} else {
15228 			tcp_req = tcp_req_find_req_for_seq(tp, ae->ack);
15229 		}
15230 #endif
15231 		memset(&log, 0, sizeof(log));
15232 		log.u_bbr.inhpts = tcp_in_hpts(rack->rc_tp);
15233 		if (rack->rack_no_prr == 0)
15234 			log.u_bbr.flex1 = rack->r_ctl.rc_prr_sndcnt;
15235 		else
15236 			log.u_bbr.flex1 = 0;
15237 		log.u_bbr.use_lt_bw = rack->r_ent_rec_ns;
15238 		log.u_bbr.use_lt_bw <<= 1;
15239 		log.u_bbr.use_lt_bw |= rack->r_might_revert;
15240 		log.u_bbr.flex2 = rack->r_ctl.rc_num_maps_alloced;
15241 		log.u_bbr.bbr_state = rack->rc_free_cnt;
15242 		log.u_bbr.inflight = ctf_flight_size(tp, rack->r_ctl.rc_sacked);
15243 		log.u_bbr.pkts_out = tp->t_maxseg;
15244 		log.u_bbr.flex4 = rack->r_ctl.rc_hpts_flags;
15245 		log.u_bbr.flex7 = 1;
15246 		log.u_bbr.lost = ae->flags;
15247 		log.u_bbr.cwnd_gain = ackval;
15248 		log.u_bbr.pacing_gain = 0x2;
15249 		if (ae->flags & TSTMP_HDWR) {
15250 			/* Record the hardware timestamp if present */
15251 			log.u_bbr.flex3 = M_TSTMP;
15252 			ts.tv_sec = ae->timestamp / 1000000000;
15253 			ts.tv_nsec = ae->timestamp % 1000000000;
15254 			ltv.tv_sec = ts.tv_sec;
15255 			ltv.tv_usec = ts.tv_nsec / 1000;
15256 			log.u_bbr.lt_epoch = tcp_tv_to_usec(&ltv);
15257 		} else if (ae->flags & TSTMP_LRO) {
15258 			/* Record the LRO the arrival timestamp */
15259 			log.u_bbr.flex3 = M_TSTMP_LRO;
15260 			ts.tv_sec = ae->timestamp / 1000000000;
15261 			ts.tv_nsec = ae->timestamp % 1000000000;
15262 			ltv.tv_sec = ts.tv_sec;
15263 			ltv.tv_usec = ts.tv_nsec / 1000;
15264 			log.u_bbr.flex5 = tcp_tv_to_usec(&ltv);
15265 		}
15266 		log.u_bbr.timeStamp = tcp_get_usecs(&ltv);
15267 		/* Log the rcv time */
15268 		log.u_bbr.delRate = ae->timestamp;
15269 #ifdef TCP_REQUEST_TRK
15270 		log.u_bbr.applimited = tp->t_tcpreq_closed;
15271 		log.u_bbr.applimited <<= 8;
15272 		log.u_bbr.applimited |= tp->t_tcpreq_open;
15273 		log.u_bbr.applimited <<= 8;
15274 		log.u_bbr.applimited |= tp->t_tcpreq_req;
15275 		if (tcp_req) {
15276 			/* Copy out any client req info */
15277 			/* seconds */
15278 			log.u_bbr.pkt_epoch = (tcp_req->localtime / HPTS_USEC_IN_SEC);
15279 			/* useconds */
15280 			log.u_bbr.delivered = (tcp_req->localtime % HPTS_USEC_IN_SEC);
15281 			log.u_bbr.rttProp = tcp_req->timestamp;
15282 			log.u_bbr.cur_del_rate = tcp_req->start;
15283 			if (tcp_req->flags & TCP_TRK_TRACK_FLG_OPEN) {
15284 				log.u_bbr.flex8 |= 1;
15285 			} else {
15286 				log.u_bbr.flex8 |= 2;
15287 				log.u_bbr.bw_inuse = tcp_req->end;
15288 			}
15289 			log.u_bbr.flex6 = tcp_req->start_seq;
15290 			if (tcp_req->flags & TCP_TRK_TRACK_FLG_COMP) {
15291 				log.u_bbr.flex8 |= 4;
15292 				log.u_bbr.epoch = tcp_req->end_seq;
15293 			}
15294 		}
15295 #endif
15296 		memset(tcp_hdr_buf, 0, sizeof(tcp_hdr_buf));
15297 		th = (struct tcphdr *)tcp_hdr_buf;
15298 		th->th_seq = ae->seq;
15299 		th->th_ack = ae->ack;
15300 		th->th_win = ae->win;
15301 		/* Now fill in the ports */
15302 		th->th_sport = inp->inp_fport;
15303 		th->th_dport = inp->inp_lport;
15304 		tcp_set_flags(th, ae->flags);
15305 		/* Now do we have a timestamp option? */
15306 		if (ae->flags & HAS_TSTMP) {
15307 			u_char *cp;
15308 			uint32_t val;
15309 
15310 			th->th_off = ((sizeof(struct tcphdr) + TCPOLEN_TSTAMP_APPA) >> 2);
15311 			cp = (u_char *)(th + 1);
15312 			*cp = TCPOPT_NOP;
15313 			cp++;
15314 			*cp = TCPOPT_NOP;
15315 			cp++;
15316 			*cp = TCPOPT_TIMESTAMP;
15317 			cp++;
15318 			*cp = TCPOLEN_TIMESTAMP;
15319 			cp++;
15320 			val = htonl(ae->ts_value);
15321 			bcopy((char *)&val,
15322 			      (char *)cp, sizeof(uint32_t));
15323 			val = htonl(ae->ts_echo);
15324 			bcopy((char *)&val,
15325 			      (char *)(cp + 4), sizeof(uint32_t));
15326 		} else
15327 			th->th_off = (sizeof(struct tcphdr) >> 2);
15328 
15329 		/*
15330 		 * For sane logging we need to play a little trick.
15331 		 * If the ack were fully processed we would have moved
15332 		 * snd_una to high_seq, but since compressed acks are
15333 		 * processed in two phases, at this point (logging) snd_una
15334 		 * won't be advanced. So we would see multiple acks showing
15335 		 * the advancement. We can prevent that by "pretending" that
15336 		 * snd_una was advanced and then un-advancing it so that the
15337 		 * logging code has the right value for tlb_snd_una.
15338 		 */
15339 		if (tp->snd_una != high_seq) {
15340 			orig_snd_una = tp->snd_una;
15341 			tp->snd_una = high_seq;
15342 			xx = 1;
15343 		} else
15344 			xx = 0;
15345 		TCP_LOG_EVENTP(tp, th,
15346 			       &tptosocket(tp)->so_rcv,
15347 			       &tptosocket(tp)->so_snd, TCP_LOG_IN, 0,
15348 			       0, &log, true, &ltv);
15349 		if (xx) {
15350 			tp->snd_una = orig_snd_una;
15351 		}
15352 	}
15353 
15354 }
15355 
15356 static void
15357 rack_handle_probe_response(struct tcp_rack *rack, uint32_t tiwin, uint32_t us_cts)
15358 {
15359 	uint32_t us_rtt;
15360 	/*
15361 	 * A persist or keep-alive was forced out, update our
15362 	 * min rtt time. Note now worry about lost responses.
15363 	 * When a subsequent keep-alive or persist times out
15364 	 * and forced_ack is still on, then the last probe
15365 	 * was not responded to. In such cases we have a
15366 	 * sysctl that controls the behavior. Either we apply
15367 	 * the rtt but with reduced confidence (0). Or we just
15368 	 * plain don't apply the rtt estimate. Having data flow
15369 	 * will clear the probe_not_answered flag i.e. cum-ack
15370 	 * move forward <or> exiting and reentering persists.
15371 	 */
15372 
15373 	rack->forced_ack = 0;
15374 	rack->rc_tp->t_rxtshift = 0;
15375 	if ((rack->rc_in_persist &&
15376 	     (tiwin == rack->rc_tp->snd_wnd)) ||
15377 	    (rack->rc_in_persist == 0)) {
15378 		/*
15379 		 * In persists only apply the RTT update if this is
15380 		 * a response to our window probe. And that
15381 		 * means the rwnd sent must match the current
15382 		 * snd_wnd. If it does not, then we got a
15383 		 * window update ack instead. For keepalive
15384 		 * we allow the answer no matter what the window.
15385 		 *
15386 		 * Note that if the probe_not_answered is set then
15387 		 * the forced_ack_ts is the oldest one i.e. the first
15388 		 * probe sent that might have been lost. This assures
15389 		 * us that if we do calculate an RTT it is longer not
15390 		 * some short thing.
15391 		 */
15392 		if (rack->rc_in_persist)
15393 			counter_u64_add(rack_persists_acks, 1);
15394 		us_rtt = us_cts - rack->r_ctl.forced_ack_ts;
15395 		if (us_rtt == 0)
15396 			us_rtt = 1;
15397 		if (rack->probe_not_answered == 0) {
15398 			rack_apply_updated_usrtt(rack, us_rtt, us_cts);
15399 			tcp_rack_xmit_timer(rack, us_rtt, 0, us_rtt, 3, NULL, 1);
15400 		} else {
15401 			/* We have a retransmitted probe here too */
15402 			if (rack_apply_rtt_with_reduced_conf) {
15403 				rack_apply_updated_usrtt(rack, us_rtt, us_cts);
15404 				tcp_rack_xmit_timer(rack, us_rtt, 0, us_rtt, 0, NULL, 1);
15405 			}
15406 		}
15407 	}
15408 }
15409 
15410 static void
15411 rack_new_round_starts(struct tcpcb *tp, struct tcp_rack *rack, uint32_t high_seq)
15412 {
15413 	/*
15414 	 * The next send has occurred mark the end of the round
15415 	 * as when that data gets acknowledged. We can
15416 	 * also do common things we might need to do when
15417 	 * a round begins.
15418 	 */
15419 	rack->r_ctl.roundends = tp->snd_max;
15420 	rack->rc_new_rnd_needed = 0;
15421 	rack_log_hystart_event(rack, tp->snd_max, 4);
15422 }
15423 
15424 
15425 static void
15426 rack_log_pcm(struct tcp_rack *rack, uint8_t mod, uint32_t flex1, uint32_t flex2,
15427 	     uint32_t flex3)
15428 {
15429 	if (tcp_bblogging_on(rack->rc_tp)) {
15430 		union tcp_log_stackspecific log;
15431 		struct timeval tv;
15432 
15433 		(void)tcp_get_usecs(&tv);
15434 		memset(&log, 0, sizeof(log));
15435 		log.u_bbr.timeStamp = tcp_tv_to_usec(&tv);
15436 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
15437 		log.u_bbr.flex8 = mod;
15438 		log.u_bbr.flex1 = flex1;
15439 		log.u_bbr.flex2 = flex2;
15440 		log.u_bbr.flex3 = flex3;
15441 		log.u_bbr.flex4 = rack_pcm_every_n_rounds;
15442 		log.u_bbr.flex5 = rack->r_ctl.pcm_idle_rounds;
15443 		log.u_bbr.bbr_substate = rack->pcm_needed;
15444 		log.u_bbr.bbr_substate <<= 1;
15445 		log.u_bbr.bbr_substate |= rack->pcm_in_progress;
15446 		log.u_bbr.bbr_substate <<= 1;
15447 		log.u_bbr.bbr_substate |= rack->pcm_enabled; /* bits are NIE for Needed, Inprogress, Enabled */
15448 		(void)tcp_log_event(rack->rc_tp, NULL, NULL, NULL, TCP_PCM_MEASURE, ERRNO_UNK,
15449 				    0, &log, false, NULL, NULL, 0, &tv);
15450 	}
15451 }
15452 
15453 static void
15454 rack_new_round_setup(struct tcpcb *tp, struct tcp_rack *rack, uint32_t high_seq)
15455 {
15456 	/*
15457 	 * The round (current_round) has ended. We now
15458 	 * setup for the next round by incrementing the
15459 	 * round numnber and doing any round specific
15460 	 * things.
15461 	 */
15462 	rack_log_hystart_event(rack, high_seq, 21);
15463 	rack->r_ctl.current_round++;
15464 	/* New round (current_round) begins at next send */
15465 	rack->rc_new_rnd_needed = 1;
15466 	if ((rack->pcm_enabled == 1) &&
15467 	    (rack->pcm_needed == 0) &&
15468 	    (rack->pcm_in_progress == 0)) {
15469 		/*
15470 		 * If we have enabled PCM, then we need to
15471 		 * check if the round has adanced to the state
15472 		 * where one is required.
15473 		 */
15474 		int rnds;
15475 
15476 		rnds = rack->r_ctl.current_round - rack->r_ctl.last_pcm_round;
15477 		if ((rnds + rack->r_ctl.pcm_idle_rounds) >= rack_pcm_every_n_rounds) {
15478 			rack->pcm_needed = 1;
15479 			rack_log_pcm(rack, 3, rack->r_ctl.last_pcm_round, rack_pcm_every_n_rounds, rack->r_ctl.current_round );
15480 		} else if (rack_verbose_logging) {
15481 			rack_log_pcm(rack, 3, rack->r_ctl.last_pcm_round, rack_pcm_every_n_rounds, rack->r_ctl.current_round );
15482 		}
15483 	}
15484 	if (tp->t_ccv.flags & CCF_HYSTART_ALLOWED) {
15485 		/* We have hystart enabled send the round info in */
15486 		if (CC_ALGO(tp)->newround != NULL) {
15487 			CC_ALGO(tp)->newround(&tp->t_ccv, rack->r_ctl.current_round);
15488 		}
15489 	}
15490 	/*
15491 	 * For DGP an initial startup check. We want to validate
15492 	 * that we are not just pushing on slow-start and just
15493 	 * not gaining.. i.e. filling buffers without getting any
15494 	 * boost in b/w during the inital slow-start.
15495 	 */
15496 	if (rack->dgp_on &&
15497 	    (rack->rc_initial_ss_comp == 0) &&
15498 	    (tp->snd_cwnd < tp->snd_ssthresh) &&
15499 	    (rack->r_ctl.num_measurements >= RACK_REQ_AVG) &&
15500 	    (rack->r_ctl.gp_rnd_thresh > 0) &&
15501 	    ((rack->r_ctl.current_round - rack->r_ctl.last_rnd_of_gp_rise) >= rack->r_ctl.gp_rnd_thresh)) {
15502 
15503 		/*
15504 		 * We are in the initial SS and we have hd rack_rnd_cnt_req rounds(def:5) where
15505 		 * we have not gained the required amount in the gp_est (120.0% aka 1200). Lets
15506 		 * exit SS.
15507 		 *
15508 		 * Pick up the flight size now as we enter slowstart (not the
15509 		 * cwnd which may be inflated).
15510 		 */
15511 		rack->rc_initial_ss_comp = 1;
15512 
15513 		if (tcp_bblogging_on(rack->rc_tp)) {
15514 			union tcp_log_stackspecific log;
15515 			struct timeval tv;
15516 
15517 			memset(&log, 0, sizeof(log));
15518 			log.u_bbr.timeStamp = tcp_get_usecs(&tv);
15519 			log.u_bbr.flex1 = rack->r_ctl.current_round;
15520 			log.u_bbr.flex2 = rack->r_ctl.last_rnd_of_gp_rise;
15521 			log.u_bbr.flex3 = rack->r_ctl.gp_rnd_thresh;
15522 			log.u_bbr.flex4 = rack->r_ctl.gate_to_fs;
15523 			log.u_bbr.flex5 = rack->r_ctl.ss_hi_fs;
15524 			log.u_bbr.flex8 = 40;
15525 			(void)tcp_log_event(tp, NULL, NULL, NULL, BBR_LOG_CWND, 0,
15526 					    0, &log, false, NULL, __func__, __LINE__,&tv);
15527 		}
15528 		if ((rack->r_ctl.gate_to_fs == 1) &&
15529 		     (tp->snd_cwnd > rack->r_ctl.ss_hi_fs)) {
15530 			tp->snd_cwnd = rack->r_ctl.ss_hi_fs;
15531 		}
15532 		tp->snd_ssthresh = tp->snd_cwnd - 1;
15533 		/* Turn off any fast output running */
15534 		rack->r_fast_output = 0;
15535 	}
15536 }
15537 
15538 static int
15539 rack_do_compressed_ack_processing(struct tcpcb *tp, struct socket *so, struct mbuf *m, int nxt_pkt, struct timeval *tv)
15540 {
15541 	/*
15542 	 * Handle a "special" compressed ack mbuf. Each incoming
15543 	 * ack has only four possible dispositions:
15544 	 *
15545 	 * A) It moves the cum-ack forward
15546 	 * B) It is behind the cum-ack.
15547 	 * C) It is a window-update ack.
15548 	 * D) It is a dup-ack.
15549 	 *
15550 	 * Note that we can have between 1 -> TCP_COMP_ACK_ENTRIES
15551 	 * in the incoming mbuf. We also need to still pay attention
15552 	 * to nxt_pkt since there may be another packet after this
15553 	 * one.
15554 	 */
15555 #ifdef TCP_ACCOUNTING
15556 	uint64_t ts_val;
15557 	uint64_t rdstc;
15558 #endif
15559 	int segsiz;
15560 	struct timespec ts;
15561 	struct tcp_rack *rack;
15562 	struct tcp_ackent *ae;
15563 	uint32_t tiwin, ms_cts, cts, acked, acked_amount, high_seq, win_seq, the_win, win_upd_ack;
15564 	int cnt, i, did_out, ourfinisacked = 0;
15565 	struct tcpopt to_holder, *to = NULL;
15566 #ifdef TCP_ACCOUNTING
15567 	int win_up_req = 0;
15568 #endif
15569 	int nsegs = 0;
15570 	int under_pacing = 0;
15571 	int post_recovery = 0;
15572 #ifdef TCP_ACCOUNTING
15573 	sched_pin();
15574 #endif
15575 	rack = (struct tcp_rack *)tp->t_fb_ptr;
15576 	if (rack->gp_ready &&
15577 	    (rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT))
15578 		under_pacing = 1;
15579 
15580 	if (rack->r_state != tp->t_state)
15581 		rack_set_state(tp, rack);
15582 	if ((tp->t_state >= TCPS_FIN_WAIT_1) &&
15583 	    (tp->t_flags & TF_GPUTINPROG)) {
15584 		/*
15585 		 * We have a goodput in progress
15586 		 * and we have entered a late state.
15587 		 * Do we have enough data in the sb
15588 		 * to handle the GPUT request?
15589 		 */
15590 		uint32_t bytes;
15591 
15592 		bytes = tp->gput_ack - tp->gput_seq;
15593 		if (SEQ_GT(tp->gput_seq, tp->snd_una))
15594 			bytes += tp->gput_seq - tp->snd_una;
15595 		if (bytes > sbavail(&tptosocket(tp)->so_snd)) {
15596 			/*
15597 			 * There are not enough bytes in the socket
15598 			 * buffer that have been sent to cover this
15599 			 * measurement. Cancel it.
15600 			 */
15601 			rack_log_pacing_delay_calc(rack, (tp->gput_ack - tp->gput_seq) /*flex2*/,
15602 						   rack->r_ctl.rc_gp_srtt /*flex1*/,
15603 						   tp->gput_seq,
15604 						   0, 0, 18, __LINE__, NULL, 0);
15605 			tp->t_flags &= ~TF_GPUTINPROG;
15606 		}
15607 	}
15608 	to = &to_holder;
15609 	to->to_flags = 0;
15610 	KASSERT((m->m_len >= sizeof(struct tcp_ackent)),
15611 		("tp:%p m_cmpack:%p with invalid len:%u", tp, m, m->m_len));
15612 	cnt = m->m_len / sizeof(struct tcp_ackent);
15613 	counter_u64_add(rack_multi_single_eq, cnt);
15614 	high_seq = tp->snd_una;
15615 	the_win = tp->snd_wnd;
15616 	win_seq = tp->snd_wl1;
15617 	win_upd_ack = tp->snd_wl2;
15618 	cts = tcp_tv_to_usec(tv);
15619 	ms_cts = tcp_tv_to_msec(tv);
15620 	rack->r_ctl.rc_rcvtime = cts;
15621 	segsiz = ctf_fixed_maxseg(tp);
15622 	if ((rack->rc_gp_dyn_mul) &&
15623 	    (rack->use_fixed_rate == 0) &&
15624 	    (rack->rc_always_pace)) {
15625 		/* Check in on probertt */
15626 		rack_check_probe_rtt(rack, cts);
15627 	}
15628 	for (i = 0; i < cnt; i++) {
15629 #ifdef TCP_ACCOUNTING
15630 		ts_val = get_cyclecount();
15631 #endif
15632 		rack_clear_rate_sample(rack);
15633 		ae = ((mtod(m, struct tcp_ackent *)) + i);
15634 		if (ae->flags & TH_FIN)
15635 			rack_log_pacing_delay_calc(rack,
15636 						   0,
15637 						   0,
15638 						   0,
15639 						   rack_get_gp_est(rack), /* delRate */
15640 						   rack_get_lt_bw(rack), /* rttProp */
15641 						   20, __LINE__, NULL, 0);
15642 		/* Setup the window */
15643 		tiwin = ae->win << tp->snd_scale;
15644 		if (tiwin > rack->r_ctl.rc_high_rwnd)
15645 			rack->r_ctl.rc_high_rwnd = tiwin;
15646 		/* figure out the type of ack */
15647 		if (SEQ_LT(ae->ack, high_seq)) {
15648 			/* Case B*/
15649 			ae->ack_val_set = ACK_BEHIND;
15650 		} else if (SEQ_GT(ae->ack, high_seq)) {
15651 			/* Case A */
15652 			ae->ack_val_set = ACK_CUMACK;
15653 		} else if ((tiwin == the_win) && (rack->rc_in_persist == 0)){
15654 			/* Case D */
15655 			ae->ack_val_set = ACK_DUPACK;
15656 		} else {
15657 			/* Case C */
15658 			ae->ack_val_set = ACK_RWND;
15659 		}
15660 		rack_log_type_bbrsnd(rack, 0, 0, cts, tv, __LINE__);
15661 		rack_log_input_packet(tp, rack, ae, ae->ack_val_set, high_seq);
15662 		/* Validate timestamp */
15663 		if (ae->flags & HAS_TSTMP) {
15664 			/* Setup for a timestamp */
15665 			to->to_flags = TOF_TS;
15666 			ae->ts_echo -= tp->ts_offset;
15667 			to->to_tsecr = ae->ts_echo;
15668 			to->to_tsval = ae->ts_value;
15669 			/*
15670 			 * If echoed timestamp is later than the current time, fall back to
15671 			 * non RFC1323 RTT calculation.  Normalize timestamp if syncookies
15672 			 * were used when this connection was established.
15673 			 */
15674 			if (TSTMP_GT(ae->ts_echo, ms_cts))
15675 				to->to_tsecr = 0;
15676 			if (tp->ts_recent &&
15677 			    TSTMP_LT(ae->ts_value, tp->ts_recent)) {
15678 				if (ctf_ts_check_ac(tp, (ae->flags & 0xff))) {
15679 #ifdef TCP_ACCOUNTING
15680 					rdstc = get_cyclecount();
15681 					if (rdstc > ts_val) {
15682 						if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
15683 							tp->tcp_proc_time[ae->ack_val_set] += (rdstc - ts_val);
15684 						}
15685 					}
15686 #endif
15687 					continue;
15688 				}
15689 			}
15690 			if (SEQ_LEQ(ae->seq, tp->last_ack_sent) &&
15691 			    SEQ_LEQ(tp->last_ack_sent, ae->seq)) {
15692 				tp->ts_recent_age = tcp_ts_getticks();
15693 				tp->ts_recent = ae->ts_value;
15694 			}
15695 		} else {
15696 			/* Setup for a no options */
15697 			to->to_flags = 0;
15698 		}
15699 		/* Update the rcv time and perform idle reduction possibly */
15700 		if  (tp->t_idle_reduce &&
15701 		     (tp->snd_max == tp->snd_una) &&
15702 		     (TICKS_2_USEC(ticks - tp->t_rcvtime) >= tp->t_rxtcur)) {
15703 			counter_u64_add(rack_input_idle_reduces, 1);
15704 			rack_cc_after_idle(rack, tp);
15705 		}
15706 		tp->t_rcvtime = ticks;
15707 		/* Now what about ECN of a chain of pure ACKs? */
15708 		if (tcp_ecn_input_segment(tp, ae->flags, 0,
15709 			tcp_packets_this_ack(tp, ae->ack),
15710 			ae->codepoint))
15711 			rack_cong_signal(tp, CC_ECN, ae->ack, __LINE__);
15712 		if (tp->t_flags & TF_ACKNOW)
15713 			rack->r_wanted_output = 1;
15714 #ifdef TCP_ACCOUNTING
15715 		/* Count for the specific type of ack in */
15716 		if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
15717 			tp->tcp_cnt_counters[ae->ack_val_set]++;
15718 		}
15719 #endif
15720 		/*
15721 		 * Note how we could move up these in the determination
15722 		 * above, but we don't so that way the timestamp checks (and ECN)
15723 		 * is done first before we do any processing on the ACK.
15724 		 * The non-compressed path through the code has this
15725 		 * weakness (noted by @jtl) that it actually does some
15726 		 * processing before verifying the timestamp information.
15727 		 * We don't take that path here which is why we set
15728 		 * the ack_val_set first, do the timestamp and ecn
15729 		 * processing, and then look at what we have setup.
15730 		 */
15731 		if (ae->ack_val_set == ACK_BEHIND) {
15732 			/*
15733 			 * Case B flag reordering, if window is not closed
15734 			 * or it could be a keep-alive or persists
15735 			 */
15736 			if (SEQ_LT(ae->ack, tp->snd_una) && (sbspace(&so->so_rcv) > segsiz)) {
15737 				rack->r_ctl.rc_reorder_ts = tcp_tv_to_usec(&rack->r_ctl.act_rcv_time);
15738 				if (rack->r_ctl.rc_reorder_ts == 0)
15739 					rack->r_ctl.rc_reorder_ts = 1;
15740 			}
15741 		} else if (ae->ack_val_set == ACK_DUPACK) {
15742 			/* Case D */
15743 			rack_strike_dupack(rack, ae->ack);
15744 		} else if (ae->ack_val_set == ACK_RWND) {
15745 			/* Case C */
15746 			if ((ae->flags & TSTMP_LRO) || (ae->flags & TSTMP_HDWR)) {
15747 				ts.tv_sec = ae->timestamp / 1000000000;
15748 				ts.tv_nsec = ae->timestamp % 1000000000;
15749 				rack->r_ctl.act_rcv_time.tv_sec = ts.tv_sec;
15750 				rack->r_ctl.act_rcv_time.tv_usec = ts.tv_nsec/1000;
15751 			} else {
15752 				rack->r_ctl.act_rcv_time = *tv;
15753 			}
15754 			if (rack->forced_ack) {
15755 				rack_handle_probe_response(rack, tiwin,
15756 							   tcp_tv_to_usec(&rack->r_ctl.act_rcv_time));
15757 			}
15758 #ifdef TCP_ACCOUNTING
15759 			win_up_req = 1;
15760 #endif
15761 			win_upd_ack = ae->ack;
15762 			win_seq = ae->seq;
15763 			the_win = tiwin;
15764 			rack_do_win_updates(tp, rack, the_win, win_seq, win_upd_ack, cts);
15765 		} else {
15766 			/* Case A */
15767 			if (SEQ_GT(ae->ack, tp->snd_max)) {
15768 				/*
15769 				 * We just send an ack since the incoming
15770 				 * ack is beyond the largest seq we sent.
15771 				 */
15772 				if ((tp->t_flags & TF_ACKNOW) == 0) {
15773 					ctf_ack_war_checks(tp);
15774 					if (tp->t_flags && TF_ACKNOW)
15775 						rack->r_wanted_output = 1;
15776 				}
15777 			} else {
15778 				nsegs++;
15779 				/* If the window changed setup to update */
15780 				if (tiwin != tp->snd_wnd) {
15781 					win_upd_ack = ae->ack;
15782 					win_seq = ae->seq;
15783 					the_win = tiwin;
15784 					rack_do_win_updates(tp, rack, the_win, win_seq, win_upd_ack, cts);
15785 				}
15786 #ifdef TCP_ACCOUNTING
15787 				/* Account for the acks */
15788 				if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
15789 					tp->tcp_cnt_counters[CNT_OF_ACKS_IN] += (((ae->ack - high_seq) + segsiz - 1) / segsiz);
15790 				}
15791 #endif
15792 				high_seq = ae->ack;
15793 				/* Setup our act_rcv_time */
15794 				if ((ae->flags & TSTMP_LRO) || (ae->flags & TSTMP_HDWR)) {
15795 					ts.tv_sec = ae->timestamp / 1000000000;
15796 					ts.tv_nsec = ae->timestamp % 1000000000;
15797 					rack->r_ctl.act_rcv_time.tv_sec = ts.tv_sec;
15798 					rack->r_ctl.act_rcv_time.tv_usec = ts.tv_nsec/1000;
15799 				} else {
15800 					rack->r_ctl.act_rcv_time = *tv;
15801 				}
15802 				rack_process_to_cumack(tp, rack, ae->ack, cts, to,
15803 						       tcp_tv_to_lusec(&rack->r_ctl.act_rcv_time));
15804 #ifdef TCP_REQUEST_TRK
15805 				rack_req_check_for_comp(rack, high_seq);
15806 #endif
15807 				if (rack->rc_dsack_round_seen) {
15808 					/* Is the dsack round over? */
15809 					if (SEQ_GEQ(ae->ack, rack->r_ctl.dsack_round_end)) {
15810 						/* Yes it is */
15811 						rack->rc_dsack_round_seen = 0;
15812 						rack_log_dsack_event(rack, 3, __LINE__, 0, 0);
15813 					}
15814 				}
15815 			}
15816 		}
15817 		/* And lets be sure to commit the rtt measurements for this ack */
15818 		tcp_rack_xmit_timer_commit(rack, tp);
15819 #ifdef TCP_ACCOUNTING
15820 		rdstc = get_cyclecount();
15821 		if (rdstc > ts_val) {
15822 			if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
15823 				tp->tcp_proc_time[ae->ack_val_set] += (rdstc - ts_val);
15824 				if (ae->ack_val_set == ACK_CUMACK)
15825 					tp->tcp_proc_time[CYC_HANDLE_MAP] += (rdstc - ts_val);
15826 			}
15827 		}
15828 #endif
15829 	}
15830 #ifdef TCP_ACCOUNTING
15831 	ts_val = get_cyclecount();
15832 #endif
15833 	/* Tend to any collapsed window */
15834 	if (SEQ_GT(tp->snd_max, high_seq) && (tp->snd_wnd < (tp->snd_max - high_seq))) {
15835 		/* The peer collapsed the window */
15836 		rack_collapsed_window(rack, (tp->snd_max - high_seq), high_seq, __LINE__);
15837 	} else if (rack->rc_has_collapsed)
15838 		rack_un_collapse_window(rack, __LINE__);
15839 	if ((rack->r_collapse_point_valid) &&
15840 	    (SEQ_GT(high_seq, rack->r_ctl.high_collapse_point)))
15841 		rack->r_collapse_point_valid = 0;
15842 	acked_amount = acked = (high_seq - tp->snd_una);
15843 	if (acked) {
15844 		/*
15845 		 * The draft (v3) calls for us to use SEQ_GEQ, but that
15846 		 * causes issues when we are just going app limited. Lets
15847 		 * instead use SEQ_GT <or> where its equal but more data
15848 		 * is outstanding.
15849 		 *
15850 		 * Also make sure we are on the last ack of a series. We
15851 		 * have to have all the ack's processed in queue to know
15852 		 * if there is something left outstanding.
15853 		 *
15854 		 */
15855 		if (SEQ_GEQ(high_seq, rack->r_ctl.roundends) &&
15856 		    (rack->rc_new_rnd_needed == 0) &&
15857 		    (nxt_pkt == 0)) {
15858 			/*
15859 			 * We have crossed into a new round with
15860 			 * this th_ack value.
15861 			 */
15862 			rack_new_round_setup(tp, rack, high_seq);
15863 		}
15864 		/*
15865 		 * Clear the probe not answered flag
15866 		 * since cum-ack moved forward.
15867 		 */
15868 		rack->probe_not_answered = 0;
15869 		if (tp->t_flags & TF_NEEDSYN) {
15870 			/*
15871 			 * T/TCP: Connection was half-synchronized, and our SYN has
15872 			 * been ACK'd (so connection is now fully synchronized).  Go
15873 			 * to non-starred state, increment snd_una for ACK of SYN,
15874 			 * and check if we can do window scaling.
15875 			 */
15876 			tp->t_flags &= ~TF_NEEDSYN;
15877 			tp->snd_una++;
15878 			acked_amount = acked = (high_seq - tp->snd_una);
15879 		}
15880 		if (acked > sbavail(&so->so_snd))
15881 			acked_amount = sbavail(&so->so_snd);
15882 		if (IN_FASTRECOVERY(tp->t_flags) &&
15883 		    (rack->rack_no_prr == 0))
15884 			rack_update_prr(tp, rack, acked_amount, high_seq);
15885 		if (IN_RECOVERY(tp->t_flags)) {
15886 			if (SEQ_LT(high_seq, tp->snd_recover) &&
15887 			    (SEQ_LT(high_seq, tp->snd_max))) {
15888 				tcp_rack_partialack(tp);
15889 			} else {
15890 				rack_post_recovery(tp, high_seq);
15891 				post_recovery = 1;
15892 			}
15893 		}  else if ((rack->rto_from_rec == 1) &&
15894 			    SEQ_GEQ(high_seq, tp->snd_recover)) {
15895 			/*
15896 			 * We were in recovery, hit a rxt timeout
15897 			 * and never re-entered recovery. The timeout(s)
15898 			 * made up all the lost data. In such a case
15899 			 * we need to clear the rto_from_rec flag.
15900 			 */
15901 			rack->rto_from_rec = 0;
15902 		}
15903 		/* Handle the rack-log-ack part (sendmap) */
15904 		if ((sbused(&so->so_snd) == 0) &&
15905 		    (acked > acked_amount) &&
15906 		    (tp->t_state >= TCPS_FIN_WAIT_1) &&
15907 		    (tp->t_flags & TF_SENTFIN)) {
15908 			/*
15909 			 * We must be sure our fin
15910 			 * was sent and acked (we can be
15911 			 * in FIN_WAIT_1 without having
15912 			 * sent the fin).
15913 			 */
15914 			ourfinisacked = 1;
15915 			/*
15916 			 * Lets make sure snd_una is updated
15917 			 * since most likely acked_amount = 0 (it
15918 			 * should be).
15919 			 */
15920 			tp->snd_una = high_seq;
15921 		}
15922 		/* Did we make a RTO error? */
15923 		if ((tp->t_flags & TF_PREVVALID) &&
15924 		    ((tp->t_flags & TF_RCVD_TSTMP) == 0)) {
15925 			tp->t_flags &= ~TF_PREVVALID;
15926 			if (tp->t_rxtshift == 1 &&
15927 			    (int)(ticks - tp->t_badrxtwin) < 0)
15928 				rack_cong_signal(tp, CC_RTO_ERR, high_seq, __LINE__);
15929 		}
15930 		/* Handle the data in the socket buffer */
15931 		KMOD_TCPSTAT_ADD(tcps_rcvackpack, 1);
15932 		KMOD_TCPSTAT_ADD(tcps_rcvackbyte, acked);
15933 		if (acked_amount > 0) {
15934 			uint32_t p_cwnd;
15935 			struct mbuf *mfree;
15936 
15937 			if (post_recovery) {
15938 				/*
15939 				 * Grab the segsiz, multiply by 2 and add the snd_cwnd
15940 				 * that is the max the CC should add if we are exiting
15941 				 * recovery and doing a late add.
15942 				 */
15943 				p_cwnd = min(ctf_fixed_maxseg(tp), rack->r_ctl.rc_pace_min_segs);
15944 				p_cwnd <<= 1;
15945 				p_cwnd += tp->snd_cwnd;
15946 			}
15947 			rack_ack_received(tp, rack, high_seq, nsegs, CC_ACK, post_recovery);
15948 			if (post_recovery && (tp->snd_cwnd > p_cwnd)) {
15949 				/* Must be non-newreno (cubic) getting too ahead of itself */
15950 				tp->snd_cwnd = p_cwnd;
15951 			}
15952 			SOCK_SENDBUF_LOCK(so);
15953 			mfree = sbcut_locked(&so->so_snd, acked_amount);
15954 			tp->snd_una = high_seq;
15955 			/* Note we want to hold the sb lock through the sendmap adjust */
15956 			rack_adjust_sendmap_head(rack, &so->so_snd);
15957 			/* Wake up the socket if we have room to write more */
15958 			rack_log_wakeup(tp,rack, &so->so_snd, acked, 2);
15959 			sowwakeup_locked(so);
15960 			m_freem(mfree);
15961 		}
15962 		/* update progress */
15963 		tp->t_acktime = ticks;
15964 		rack_log_progress_event(rack, tp, tp->t_acktime,
15965 					PROGRESS_UPDATE, __LINE__);
15966 		/* Clear out shifts and such */
15967 		tp->t_rxtshift = 0;
15968 		RACK_TCPT_RANGESET(tp->t_rxtcur, RACK_REXMTVAL(tp),
15969 				   rack_rto_min, rack_rto_max, rack->r_ctl.timer_slop);
15970 		rack->rc_tlp_in_progress = 0;
15971 		rack->r_ctl.rc_tlp_cnt_out = 0;
15972 		/* Send recover and snd_nxt must be dragged along */
15973 		if (SEQ_GT(tp->snd_una, tp->snd_recover))
15974 			tp->snd_recover = tp->snd_una;
15975 		if (SEQ_LT(tp->snd_nxt, tp->snd_max))
15976 			tp->snd_nxt = tp->snd_max;
15977 		/*
15978 		 * If the RXT timer is running we want to
15979 		 * stop it, so we can restart a TLP (or new RXT).
15980 		 */
15981 		if (rack->r_ctl.rc_hpts_flags & PACE_TMR_RXT)
15982 			rack_timer_cancel(tp, rack, rack->r_ctl.rc_rcvtime, __LINE__);
15983 		tp->snd_wl2 = high_seq;
15984 		tp->t_dupacks = 0;
15985 		if (under_pacing &&
15986 		    (rack->use_fixed_rate == 0) &&
15987 		    (rack->in_probe_rtt == 0) &&
15988 		    rack->rc_gp_dyn_mul &&
15989 		    rack->rc_always_pace) {
15990 			/* Check if we are dragging bottom */
15991 			rack_check_bottom_drag(tp, rack, so);
15992 		}
15993 		if (tp->snd_una == tp->snd_max) {
15994 			tp->t_flags &= ~TF_PREVVALID;
15995 			rack->r_ctl.retran_during_recovery = 0;
15996 			rack->rc_suspicious = 0;
15997 			rack->r_ctl.dsack_byte_cnt = 0;
15998 			rack->r_ctl.rc_went_idle_time = tcp_get_usecs(NULL);
15999 			if (rack->r_ctl.rc_went_idle_time == 0)
16000 				rack->r_ctl.rc_went_idle_time = 1;
16001 			rack_log_progress_event(rack, tp, 0, PROGRESS_CLEAR, __LINE__);
16002 			if (sbavail(&tptosocket(tp)->so_snd) == 0)
16003 				tp->t_acktime = 0;
16004 			/* Set so we might enter persists... */
16005 			rack->r_wanted_output = 1;
16006 			rack_timer_cancel(tp, rack, rack->r_ctl.rc_rcvtime, __LINE__);
16007 			sack_filter_clear(&rack->r_ctl.rack_sf, tp->snd_una);
16008 			if ((tp->t_state >= TCPS_FIN_WAIT_1) &&
16009 			    (sbavail(&so->so_snd) == 0) &&
16010 			    (tp->t_flags2 & TF2_DROP_AF_DATA)) {
16011 				/*
16012 				 * The socket was gone and the
16013 				 * peer sent data (not now in the past), time to
16014 				 * reset him.
16015 				 */
16016 				rack_timer_cancel(tp, rack, rack->r_ctl.rc_rcvtime, __LINE__);
16017 				/* tcp_close will kill the inp pre-log the Reset */
16018 				tcp_log_end_status(tp, TCP_EI_STATUS_SERVER_RST);
16019 #ifdef TCP_ACCOUNTING
16020 				rdstc = get_cyclecount();
16021 				if (rdstc > ts_val) {
16022 					if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
16023 						tp->tcp_proc_time[ACK_CUMACK] += (rdstc - ts_val);
16024 						tp->tcp_proc_time[CYC_HANDLE_ACK] += (rdstc - ts_val);
16025 					}
16026 				}
16027 #endif
16028 				m_freem(m);
16029 				tp = tcp_close(tp);
16030 				if (tp == NULL) {
16031 #ifdef TCP_ACCOUNTING
16032 					sched_unpin();
16033 #endif
16034 					return (1);
16035 				}
16036 				/*
16037 				 * We would normally do drop-with-reset which would
16038 				 * send back a reset. We can't since we don't have
16039 				 * all the needed bits. Instead lets arrange for
16040 				 * a call to tcp_output(). That way since we
16041 				 * are in the closed state we will generate a reset.
16042 				 *
16043 				 * Note if tcp_accounting is on we don't unpin since
16044 				 * we do that after the goto label.
16045 				 */
16046 				goto send_out_a_rst;
16047 			}
16048 			if ((sbused(&so->so_snd) == 0) &&
16049 			    (tp->t_state >= TCPS_FIN_WAIT_1) &&
16050 			    (tp->t_flags & TF_SENTFIN)) {
16051 				/*
16052 				 * If we can't receive any more data, then closing user can
16053 				 * proceed. Starting the timer is contrary to the
16054 				 * specification, but if we don't get a FIN we'll hang
16055 				 * forever.
16056 				 *
16057 				 */
16058 				if (so->so_rcv.sb_state & SBS_CANTRCVMORE) {
16059 					soisdisconnected(so);
16060 					tcp_timer_activate(tp, TT_2MSL,
16061 							   (tcp_fast_finwait2_recycle ?
16062 							    tcp_finwait2_timeout :
16063 							    TP_MAXIDLE(tp)));
16064 				}
16065 				if (ourfinisacked == 0) {
16066 					/*
16067 					 * We don't change to fin-wait-2 if we have our fin acked
16068 					 * which means we are probably in TCPS_CLOSING.
16069 					 */
16070 					tcp_state_change(tp, TCPS_FIN_WAIT_2);
16071 				}
16072 			}
16073 		}
16074 		/* Wake up the socket if we have room to write more */
16075 		if (sbavail(&so->so_snd)) {
16076 			rack->r_wanted_output = 1;
16077 			if (ctf_progress_timeout_check(tp, true)) {
16078 				rack_log_progress_event((struct tcp_rack *)tp->t_fb_ptr,
16079 							tp, tick, PROGRESS_DROP, __LINE__);
16080 				/*
16081 				 * We cheat here and don't send a RST, we should send one
16082 				 * when the pacer drops the connection.
16083 				 */
16084 #ifdef TCP_ACCOUNTING
16085 				rdstc = get_cyclecount();
16086 				if (rdstc > ts_val) {
16087 					if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
16088 						tp->tcp_proc_time[ACK_CUMACK] += (rdstc - ts_val);
16089 						tp->tcp_proc_time[CYC_HANDLE_ACK] += (rdstc - ts_val);
16090 					}
16091 				}
16092 				sched_unpin();
16093 #endif
16094 				(void)tcp_drop(tp, ETIMEDOUT);
16095 				m_freem(m);
16096 				return (1);
16097 			}
16098 		}
16099 		if (ourfinisacked) {
16100 			switch(tp->t_state) {
16101 			case TCPS_CLOSING:
16102 #ifdef TCP_ACCOUNTING
16103 				rdstc = get_cyclecount();
16104 				if (rdstc > ts_val) {
16105 					if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
16106 						tp->tcp_proc_time[ACK_CUMACK] += (rdstc - ts_val);
16107 						tp->tcp_proc_time[CYC_HANDLE_ACK] += (rdstc - ts_val);
16108 					}
16109 				}
16110 				sched_unpin();
16111 #endif
16112 				tcp_twstart(tp);
16113 				m_freem(m);
16114 				return (1);
16115 				break;
16116 			case TCPS_LAST_ACK:
16117 #ifdef TCP_ACCOUNTING
16118 				rdstc = get_cyclecount();
16119 				if (rdstc > ts_val) {
16120 					if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
16121 						tp->tcp_proc_time[ACK_CUMACK] += (rdstc - ts_val);
16122 						tp->tcp_proc_time[CYC_HANDLE_ACK] += (rdstc - ts_val);
16123 					}
16124 				}
16125 				sched_unpin();
16126 #endif
16127 				tp = tcp_close(tp);
16128 				ctf_do_drop(m, tp);
16129 				return (1);
16130 				break;
16131 			case TCPS_FIN_WAIT_1:
16132 #ifdef TCP_ACCOUNTING
16133 				rdstc = get_cyclecount();
16134 				if (rdstc > ts_val) {
16135 					if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
16136 						tp->tcp_proc_time[ACK_CUMACK] += (rdstc - ts_val);
16137 						tp->tcp_proc_time[CYC_HANDLE_ACK] += (rdstc - ts_val);
16138 					}
16139 				}
16140 #endif
16141 				if (so->so_rcv.sb_state & SBS_CANTRCVMORE) {
16142 					soisdisconnected(so);
16143 					tcp_timer_activate(tp, TT_2MSL,
16144 							   (tcp_fast_finwait2_recycle ?
16145 							    tcp_finwait2_timeout :
16146 							    TP_MAXIDLE(tp)));
16147 				}
16148 				tcp_state_change(tp, TCPS_FIN_WAIT_2);
16149 				break;
16150 			default:
16151 				break;
16152 			}
16153 		}
16154 		if (rack->r_fast_output) {
16155 			/*
16156 			 * We re doing fast output.. can we expand that?
16157 			 */
16158 			rack_gain_for_fastoutput(rack, tp, so, acked_amount);
16159 		}
16160 #ifdef TCP_ACCOUNTING
16161 		rdstc = get_cyclecount();
16162 		if (rdstc > ts_val) {
16163 			if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
16164 				tp->tcp_proc_time[ACK_CUMACK] += (rdstc - ts_val);
16165 				tp->tcp_proc_time[CYC_HANDLE_ACK] += (rdstc - ts_val);
16166 			}
16167 		}
16168 
16169 	} else if (win_up_req) {
16170 		rdstc = get_cyclecount();
16171 		if (rdstc > ts_val) {
16172 			if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
16173 				tp->tcp_proc_time[ACK_RWND] += (rdstc - ts_val);
16174 			}
16175 		}
16176 #endif
16177 	}
16178 	/* Now is there a next packet, if so we are done */
16179 	m_freem(m);
16180 	did_out = 0;
16181 	if (nxt_pkt) {
16182 #ifdef TCP_ACCOUNTING
16183 		sched_unpin();
16184 #endif
16185 		rack_log_doseg_done(rack, cts, nxt_pkt, did_out, 5, nsegs);
16186 		return (0);
16187 	}
16188 	rack_handle_might_revert(tp, rack);
16189 	ctf_calc_rwin(so, tp);
16190 	if ((rack->r_wanted_output != 0) ||
16191 	    (rack->r_fast_output != 0) ||
16192 	    (tp->t_flags & TF_ACKNOW )) {
16193 	send_out_a_rst:
16194 		if (tcp_output(tp) < 0) {
16195 #ifdef TCP_ACCOUNTING
16196 			sched_unpin();
16197 #endif
16198 			return (1);
16199 		}
16200 		did_out = 1;
16201 	}
16202 	if (tp->t_flags2 & TF2_HPTS_CALLS)
16203 		tp->t_flags2 &= ~TF2_HPTS_CALLS;
16204 	rack_free_trim(rack);
16205 #ifdef TCP_ACCOUNTING
16206 	sched_unpin();
16207 #endif
16208 	rack_timer_audit(tp, rack, &so->so_snd);
16209 	rack_log_doseg_done(rack, cts, nxt_pkt, did_out, 6, nsegs);
16210 	return (0);
16211 }
16212 
16213 #define	TCP_LRO_TS_OPTION \
16214     ntohl((TCPOPT_NOP << 24) | (TCPOPT_NOP << 16) | \
16215 	  (TCPOPT_TIMESTAMP << 8) | TCPOLEN_TIMESTAMP)
16216 
16217 static int
16218 rack_do_segment_nounlock(struct tcpcb *tp, struct mbuf *m, struct tcphdr *th,
16219     int32_t drop_hdrlen, int32_t tlen, uint8_t iptos, int32_t nxt_pkt,
16220     struct timeval *tv)
16221 {
16222 	struct inpcb *inp = tptoinpcb(tp);
16223 	struct socket *so = tptosocket(tp);
16224 #ifdef TCP_ACCOUNTING
16225 	uint64_t ts_val;
16226 #endif
16227 	int32_t thflags, retval, did_out = 0;
16228 	int32_t way_out = 0;
16229 	/*
16230 	 * cts - is the current time from tv (caller gets ts) in microseconds.
16231 	 * ms_cts - is the current time from tv in milliseconds.
16232 	 * us_cts - is the time that LRO or hardware actually got the packet in microseconds.
16233 	 */
16234 	uint32_t cts, us_cts, ms_cts;
16235 	uint32_t tiwin;
16236 	struct timespec ts;
16237 	struct tcpopt to;
16238 	struct tcp_rack *rack;
16239 	struct rack_sendmap *rsm;
16240 	int32_t prev_state = 0;
16241 	int no_output = 0;
16242 	int time_remaining = 0;
16243 #ifdef TCP_ACCOUNTING
16244 	int ack_val_set = 0xf;
16245 #endif
16246 	int nsegs;
16247 
16248 	NET_EPOCH_ASSERT();
16249 	INP_WLOCK_ASSERT(inp);
16250 
16251 	/*
16252 	 * tv passed from common code is from either M_TSTMP_LRO or
16253 	 * tcp_get_usecs() if no LRO m_pkthdr timestamp is present.
16254 	 */
16255 	rack = (struct tcp_rack *)tp->t_fb_ptr;
16256 	if (rack->rack_deferred_inited == 0) {
16257 		/*
16258 		 * If we are the connecting socket we will
16259 		 * hit rack_init() when no sequence numbers
16260 		 * are setup. This makes it so we must defer
16261 		 * some initialization. Call that now.
16262 		 */
16263 		rack_deferred_init(tp, rack);
16264 	}
16265 	/*
16266 	 * Check to see if we need to skip any output plans. This
16267 	 * can happen in the non-LRO path where we are pacing and
16268 	 * must process the ack coming in but need to defer sending
16269 	 * anything becase a pacing timer is running.
16270 	 */
16271 	us_cts = tcp_tv_to_usec(tv);
16272 	if (m->m_flags & M_ACKCMP) {
16273 		/*
16274 		 * All compressed ack's are ack's by definition so
16275 		 * remove any ack required flag and then do the processing.
16276 		 */
16277 		rack->rc_ack_required = 0;
16278 		return (rack_do_compressed_ack_processing(tp, so, m, nxt_pkt, tv));
16279 	}
16280 	thflags = tcp_get_flags(th);
16281 	if ((rack->rc_always_pace == 1) &&
16282 	    (rack->rc_ack_can_sendout_data == 0) &&
16283 	    (rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT) &&
16284 	    (TSTMP_LT(us_cts, rack->r_ctl.rc_last_output_to))) {
16285 		/*
16286 		 * Ok conditions are right for queuing the packets
16287 		 * but we do have to check the flags in the inp, it
16288 		 * could be, if a sack is present, we want to be awoken and
16289 		 * so should process the packets.
16290 		 */
16291 		time_remaining = rack->r_ctl.rc_last_output_to - us_cts;
16292 		if (rack->rc_tp->t_flags2 & TF2_DONT_SACK_QUEUE) {
16293 			no_output = 1;
16294 		} else {
16295 			/*
16296 			 * If there is no options, or just a
16297 			 * timestamp option, we will want to queue
16298 			 * the packets. This is the same that LRO does
16299 			 * and will need to change with accurate ECN.
16300 			 */
16301 			uint32_t *ts_ptr;
16302 			int optlen;
16303 
16304 			optlen = (th->th_off << 2) - sizeof(struct tcphdr);
16305 			ts_ptr = (uint32_t *)(th + 1);
16306 			if ((optlen == 0) ||
16307 			    ((optlen == TCPOLEN_TSTAMP_APPA) &&
16308 			     (*ts_ptr == TCP_LRO_TS_OPTION)))
16309 				no_output = 1;
16310 		}
16311 		if ((no_output == 1) && (time_remaining < tcp_min_hptsi_time)) {
16312 			/*
16313 			 * It is unrealistic to think we can pace in less than
16314 			 * the minimum granularity of the pacer (def:250usec). So
16315 			 * if we have less than that time remaining we should go
16316 			 * ahead and allow output to be "early". We will attempt to
16317 			 * make up for it in any pacing time we try to apply on
16318 			 * the outbound packet.
16319 			 */
16320 			no_output = 0;
16321 		}
16322 	}
16323 	/*
16324 	 * If there is a RST or FIN lets dump out the bw
16325 	 * with a FIN the connection may go on but we
16326 	 * may not.
16327 	 */
16328 	if ((thflags & TH_FIN) || (thflags & TH_RST))
16329 		rack_log_pacing_delay_calc(rack,
16330 					   rack->r_ctl.gp_bw,
16331 					   0,
16332 					   0,
16333 					   rack_get_gp_est(rack), /* delRate */
16334 					   rack_get_lt_bw(rack), /* rttProp */
16335 					   20, __LINE__, NULL, 0);
16336 	if (m->m_flags & M_ACKCMP) {
16337 		panic("Impossible reach m has ackcmp? m:%p tp:%p", m, tp);
16338 	}
16339 	cts = tcp_tv_to_usec(tv);
16340 	ms_cts =  tcp_tv_to_msec(tv);
16341 	nsegs = m->m_pkthdr.lro_nsegs;
16342 	counter_u64_add(rack_proc_non_comp_ack, 1);
16343 #ifdef TCP_ACCOUNTING
16344 	sched_pin();
16345 	if (thflags & TH_ACK)
16346 		ts_val = get_cyclecount();
16347 #endif
16348 	if ((m->m_flags & M_TSTMP) ||
16349 	    (m->m_flags & M_TSTMP_LRO)) {
16350 		mbuf_tstmp2timespec(m, &ts);
16351 		rack->r_ctl.act_rcv_time.tv_sec = ts.tv_sec;
16352 		rack->r_ctl.act_rcv_time.tv_usec = ts.tv_nsec/1000;
16353 	} else
16354 		rack->r_ctl.act_rcv_time = *tv;
16355 	kern_prefetch(rack, &prev_state);
16356 	prev_state = 0;
16357 	/*
16358 	 * Unscale the window into a 32-bit value. For the SYN_SENT state
16359 	 * the scale is zero.
16360 	 */
16361 	tiwin = th->th_win << tp->snd_scale;
16362 #ifdef TCP_ACCOUNTING
16363 	if (thflags & TH_ACK) {
16364 		/*
16365 		 * We have a tradeoff here. We can either do what we are
16366 		 * doing i.e. pinning to this CPU and then doing the accounting
16367 		 * <or> we could do a critical enter, setup the rdtsc and cpu
16368 		 * as in below, and then validate we are on the same CPU on
16369 		 * exit. I have choosen to not do the critical enter since
16370 		 * that often will gain you a context switch, and instead lock
16371 		 * us (line above this if) to the same CPU with sched_pin(). This
16372 		 * means we may be context switched out for a higher priority
16373 		 * interupt but we won't be moved to another CPU.
16374 		 *
16375 		 * If this occurs (which it won't very often since we most likely
16376 		 * are running this code in interupt context and only a higher
16377 		 * priority will bump us ... clock?) we will falsely add in
16378 		 * to the time the interupt processing time plus the ack processing
16379 		 * time. This is ok since its a rare event.
16380 		 */
16381 		ack_val_set = tcp_do_ack_accounting(tp, th, &to, tiwin,
16382 						    ctf_fixed_maxseg(tp));
16383 	}
16384 #endif
16385 	/*
16386 	 * Parse options on any incoming segment.
16387 	 */
16388 	memset(&to, 0, sizeof(to));
16389 	tcp_dooptions(&to, (u_char *)(th + 1),
16390 	    (th->th_off << 2) - sizeof(struct tcphdr),
16391 	    (thflags & TH_SYN) ? TO_SYN : 0);
16392 	KASSERT(tp->t_state > TCPS_LISTEN, ("%s: TCPS_LISTEN",
16393 	    __func__));
16394 	KASSERT(tp->t_state != TCPS_TIME_WAIT, ("%s: TCPS_TIME_WAIT",
16395 	    __func__));
16396 	if (tp->t_flags2 & TF2_PROC_SACK_PROHIBIT) {
16397 		/*
16398 		 * We don't look at sack's from the
16399 		 * peer because the MSS is too small which
16400 		 * can subject us to an attack.
16401 		 */
16402 		to.to_flags &= ~TOF_SACK;
16403 	}
16404 	if ((tp->t_state >= TCPS_FIN_WAIT_1) &&
16405 	    (tp->t_flags & TF_GPUTINPROG)) {
16406 		/*
16407 		 * We have a goodput in progress
16408 		 * and we have entered a late state.
16409 		 * Do we have enough data in the sb
16410 		 * to handle the GPUT request?
16411 		 */
16412 		uint32_t bytes;
16413 
16414 		bytes = tp->gput_ack - tp->gput_seq;
16415 		if (SEQ_GT(tp->gput_seq, tp->snd_una))
16416 			bytes += tp->gput_seq - tp->snd_una;
16417 		if (bytes > sbavail(&tptosocket(tp)->so_snd)) {
16418 			/*
16419 			 * There are not enough bytes in the socket
16420 			 * buffer that have been sent to cover this
16421 			 * measurement. Cancel it.
16422 			 */
16423 			rack_log_pacing_delay_calc(rack, (tp->gput_ack - tp->gput_seq) /*flex2*/,
16424 						   rack->r_ctl.rc_gp_srtt /*flex1*/,
16425 						   tp->gput_seq,
16426 						   0, 0, 18, __LINE__, NULL, 0);
16427 			tp->t_flags &= ~TF_GPUTINPROG;
16428 		}
16429 	}
16430 	if (tcp_bblogging_on(rack->rc_tp)) {
16431 		union tcp_log_stackspecific log;
16432 		struct timeval ltv;
16433 #ifdef TCP_REQUEST_TRK
16434 		struct tcp_sendfile_track *tcp_req;
16435 
16436 		if (SEQ_GT(th->th_ack, tp->snd_una)) {
16437 			tcp_req = tcp_req_find_req_for_seq(tp, (th->th_ack-1));
16438 		} else {
16439 			tcp_req = tcp_req_find_req_for_seq(tp, th->th_ack);
16440 		}
16441 #endif
16442 		memset(&log, 0, sizeof(log));
16443 		log.u_bbr.inhpts = tcp_in_hpts(rack->rc_tp);
16444 		if (rack->rack_no_prr == 0)
16445 			log.u_bbr.flex1 = rack->r_ctl.rc_prr_sndcnt;
16446 		else
16447 			log.u_bbr.flex1 = 0;
16448 		log.u_bbr.use_lt_bw = rack->r_ent_rec_ns;
16449 		log.u_bbr.use_lt_bw <<= 1;
16450 		log.u_bbr.use_lt_bw |= rack->r_might_revert;
16451 		log.u_bbr.flex2 = rack->r_ctl.rc_num_maps_alloced;
16452 		log.u_bbr.bbr_state = rack->rc_free_cnt;
16453 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
16454 		log.u_bbr.pkts_out = rack->rc_tp->t_maxseg;
16455 		log.u_bbr.flex3 = m->m_flags;
16456 		log.u_bbr.flex4 = rack->r_ctl.rc_hpts_flags;
16457 		log.u_bbr.lost = thflags;
16458 		log.u_bbr.pacing_gain = 0x1;
16459 #ifdef TCP_ACCOUNTING
16460 		log.u_bbr.cwnd_gain = ack_val_set;
16461 #endif
16462 		log.u_bbr.flex7 = 2;
16463 		if (m->m_flags & M_TSTMP) {
16464 			/* Record the hardware timestamp if present */
16465 			mbuf_tstmp2timespec(m, &ts);
16466 			ltv.tv_sec = ts.tv_sec;
16467 			ltv.tv_usec = ts.tv_nsec / 1000;
16468 			log.u_bbr.lt_epoch = tcp_tv_to_usec(&ltv);
16469 		} else if (m->m_flags & M_TSTMP_LRO) {
16470 			/* Record the LRO the arrival timestamp */
16471 			mbuf_tstmp2timespec(m, &ts);
16472 			ltv.tv_sec = ts.tv_sec;
16473 			ltv.tv_usec = ts.tv_nsec / 1000;
16474 			log.u_bbr.flex5 = tcp_tv_to_usec(&ltv);
16475 		}
16476 		log.u_bbr.timeStamp = tcp_get_usecs(&ltv);
16477 		/* Log the rcv time */
16478 		log.u_bbr.delRate = m->m_pkthdr.rcv_tstmp;
16479 #ifdef TCP_REQUEST_TRK
16480 		log.u_bbr.applimited = tp->t_tcpreq_closed;
16481 		log.u_bbr.applimited <<= 8;
16482 		log.u_bbr.applimited |= tp->t_tcpreq_open;
16483 		log.u_bbr.applimited <<= 8;
16484 		log.u_bbr.applimited |= tp->t_tcpreq_req;
16485 		if (tcp_req) {
16486 			/* Copy out any client req info */
16487 			/* seconds */
16488 			log.u_bbr.pkt_epoch = (tcp_req->localtime / HPTS_USEC_IN_SEC);
16489 			/* useconds */
16490 			log.u_bbr.delivered = (tcp_req->localtime % HPTS_USEC_IN_SEC);
16491 			log.u_bbr.rttProp = tcp_req->timestamp;
16492 			log.u_bbr.cur_del_rate = tcp_req->start;
16493 			if (tcp_req->flags & TCP_TRK_TRACK_FLG_OPEN) {
16494 				log.u_bbr.flex8 |= 1;
16495 			} else {
16496 				log.u_bbr.flex8 |= 2;
16497 				log.u_bbr.bw_inuse = tcp_req->end;
16498 			}
16499 			log.u_bbr.flex6 = tcp_req->start_seq;
16500 			if (tcp_req->flags & TCP_TRK_TRACK_FLG_COMP) {
16501 				log.u_bbr.flex8 |= 4;
16502 				log.u_bbr.epoch = tcp_req->end_seq;
16503 			}
16504 		}
16505 #endif
16506 		TCP_LOG_EVENTP(tp, th, &so->so_rcv, &so->so_snd, TCP_LOG_IN, 0,
16507 		    tlen, &log, true, &ltv);
16508 	}
16509 	/* Remove ack required flag if set, we have one  */
16510 	if (thflags & TH_ACK)
16511 		rack->rc_ack_required = 0;
16512 	rack_log_type_bbrsnd(rack, 0, 0, cts, tv, __LINE__);
16513 	if ((thflags & TH_SYN) && (thflags & TH_FIN) && V_drop_synfin) {
16514 		way_out = 4;
16515 		retval = 0;
16516 		m_freem(m);
16517 		goto done_with_input;
16518 	}
16519 	/*
16520 	 * If a segment with the ACK-bit set arrives in the SYN-SENT state
16521 	 * check SEQ.ACK first as described on page 66 of RFC 793, section 3.9.
16522 	 */
16523 	if ((tp->t_state == TCPS_SYN_SENT) && (thflags & TH_ACK) &&
16524 	    (SEQ_LEQ(th->th_ack, tp->iss) || SEQ_GT(th->th_ack, tp->snd_max))) {
16525 		tcp_log_end_status(tp, TCP_EI_STATUS_RST_IN_FRONT);
16526 		ctf_do_dropwithreset(m, tp, th, tlen);
16527 #ifdef TCP_ACCOUNTING
16528 		sched_unpin();
16529 #endif
16530 		return (1);
16531 	}
16532 	/*
16533 	 * If timestamps were negotiated during SYN/ACK and a
16534 	 * segment without a timestamp is received, silently drop
16535 	 * the segment, unless it is a RST segment or missing timestamps are
16536 	 * tolerated.
16537 	 * See section 3.2 of RFC 7323.
16538 	 */
16539 	if ((tp->t_flags & TF_RCVD_TSTMP) && !(to.to_flags & TOF_TS) &&
16540 	    ((thflags & TH_RST) == 0) && (V_tcp_tolerate_missing_ts == 0)) {
16541 		way_out = 5;
16542 		retval = 0;
16543 		m_freem(m);
16544 		goto done_with_input;
16545 	}
16546 	/*
16547 	 * Segment received on connection. Reset idle time and keep-alive
16548 	 * timer. XXX: This should be done after segment validation to
16549 	 * ignore broken/spoofed segs.
16550 	 */
16551 	if  (tp->t_idle_reduce &&
16552 	     (tp->snd_max == tp->snd_una) &&
16553 	     (TICKS_2_USEC(ticks - tp->t_rcvtime) >= tp->t_rxtcur)) {
16554 		counter_u64_add(rack_input_idle_reduces, 1);
16555 		rack_cc_after_idle(rack, tp);
16556 	}
16557 	tp->t_rcvtime = ticks;
16558 #ifdef STATS
16559 	stats_voi_update_abs_ulong(tp->t_stats, VOI_TCP_FRWIN, tiwin);
16560 #endif
16561 	if (tiwin > rack->r_ctl.rc_high_rwnd)
16562 		rack->r_ctl.rc_high_rwnd = tiwin;
16563 	/*
16564 	 * TCP ECN processing. XXXJTL: If we ever use ECN, we need to move
16565 	 * this to occur after we've validated the segment.
16566 	 */
16567 	if (tcp_ecn_input_segment(tp, thflags, tlen,
16568 	    tcp_packets_this_ack(tp, th->th_ack),
16569 	    iptos))
16570 		rack_cong_signal(tp, CC_ECN, th->th_ack, __LINE__);
16571 	if (tp->t_flags & TF_ACKNOW)
16572 		rack->r_wanted_output = 1;
16573 	/*
16574 	 * If echoed timestamp is later than the current time, fall back to
16575 	 * non RFC1323 RTT calculation.  Normalize timestamp if syncookies
16576 	 * were used when this connection was established.
16577 	 */
16578 	if ((to.to_flags & TOF_TS) && (to.to_tsecr != 0)) {
16579 		to.to_tsecr -= tp->ts_offset;
16580 		if (TSTMP_GT(to.to_tsecr, ms_cts))
16581 			to.to_tsecr = 0;
16582 	}
16583 	if ((rack->r_rcvpath_rtt_up == 1) &&
16584 	    (to.to_flags & TOF_TS) &&
16585 	    (TSTMP_GEQ(to.to_tsecr, rack->r_ctl.last_rcv_tstmp_for_rtt))) {
16586 		uint32_t rtt = 0;
16587 
16588 		/*
16589 		 * We are receiving only and thus not sending
16590 		 * data to do an RTT. We set a flag when we first
16591 		 * sent this TS to the peer. We now have it back
16592 		 * and have an RTT to share. We log it as a conf
16593 		 * 4, we are not so sure about it.. since we
16594 		 * may have lost an ack.
16595 		 */
16596 		if (TSTMP_GT(cts, rack->r_ctl.last_time_of_arm_rcv))
16597 		    rtt = (cts - rack->r_ctl.last_time_of_arm_rcv);
16598 		rack->r_rcvpath_rtt_up = 0;
16599 		/* Submit and commit the timer */
16600 		if (rtt > 0) {
16601 			tcp_rack_xmit_timer(rack, rtt, 0, rtt, 4, NULL, 1);
16602 			tcp_rack_xmit_timer_commit(rack, tp);
16603 		}
16604 	}
16605 	/*
16606 	 * If its the first time in we need to take care of options and
16607 	 * verify we can do SACK for rack!
16608 	 */
16609 	if (rack->r_state == 0) {
16610 		/* Should be init'd by rack_init() */
16611 		KASSERT(rack->rc_inp != NULL,
16612 		    ("%s: rack->rc_inp unexpectedly NULL", __func__));
16613 		if (rack->rc_inp == NULL) {
16614 			rack->rc_inp = inp;
16615 		}
16616 
16617 		/*
16618 		 * Process options only when we get SYN/ACK back. The SYN
16619 		 * case for incoming connections is handled in tcp_syncache.
16620 		 * According to RFC1323 the window field in a SYN (i.e., a
16621 		 * <SYN> or <SYN,ACK>) segment itself is never scaled. XXX
16622 		 * this is traditional behavior, may need to be cleaned up.
16623 		 */
16624 		if (tp->t_state == TCPS_SYN_SENT && (thflags & TH_SYN)) {
16625 			/* Handle parallel SYN for ECN */
16626 			tcp_ecn_input_parallel_syn(tp, thflags, iptos);
16627 			if ((to.to_flags & TOF_SCALE) &&
16628 			    (tp->t_flags & TF_REQ_SCALE)) {
16629 				tp->t_flags |= TF_RCVD_SCALE;
16630 				tp->snd_scale = to.to_wscale;
16631 			} else
16632 				tp->t_flags &= ~TF_REQ_SCALE;
16633 			/*
16634 			 * Initial send window.  It will be updated with the
16635 			 * next incoming segment to the scaled value.
16636 			 */
16637 			tp->snd_wnd = th->th_win;
16638 			rack_validate_fo_sendwin_up(tp, rack);
16639 			if ((to.to_flags & TOF_TS) &&
16640 			    (tp->t_flags & TF_REQ_TSTMP)) {
16641 				tp->t_flags |= TF_RCVD_TSTMP;
16642 				tp->ts_recent = to.to_tsval;
16643 				tp->ts_recent_age = cts;
16644 			} else
16645 				tp->t_flags &= ~TF_REQ_TSTMP;
16646 			if (to.to_flags & TOF_MSS) {
16647 				tcp_mss(tp, to.to_mss);
16648 			}
16649 			if ((tp->t_flags & TF_SACK_PERMIT) &&
16650 			    (to.to_flags & TOF_SACKPERM) == 0)
16651 				tp->t_flags &= ~TF_SACK_PERMIT;
16652 			if (tp->t_flags & TF_FASTOPEN) {
16653 				if (to.to_flags & TOF_FASTOPEN) {
16654 					uint16_t mss;
16655 
16656 					if (to.to_flags & TOF_MSS)
16657 						mss = to.to_mss;
16658 					else
16659 						if ((inp->inp_vflag & INP_IPV6) != 0)
16660 							mss = TCP6_MSS;
16661 						else
16662 							mss = TCP_MSS;
16663 					tcp_fastopen_update_cache(tp, mss,
16664 					    to.to_tfo_len, to.to_tfo_cookie);
16665 				} else
16666 					tcp_fastopen_disable_path(tp);
16667 			}
16668 		}
16669 		/*
16670 		 * At this point we are at the initial call. Here we decide
16671 		 * if we are doing RACK or not. We do this by seeing if
16672 		 * TF_SACK_PERMIT is set and the sack-not-required is clear.
16673 		 * The code now does do dup-ack counting so if you don't
16674 		 * switch back you won't get rack & TLP, but you will still
16675 		 * get this stack.
16676 		 */
16677 
16678 		if ((rack_sack_not_required == 0) &&
16679 		    ((tp->t_flags & TF_SACK_PERMIT) == 0)) {
16680 			tcp_switch_back_to_default(tp);
16681 			(*tp->t_fb->tfb_tcp_do_segment)(tp, m, th, drop_hdrlen,
16682 			    tlen, iptos);
16683 #ifdef TCP_ACCOUNTING
16684 			sched_unpin();
16685 #endif
16686 			return (1);
16687 		}
16688 		tcp_set_hpts(tp);
16689 		sack_filter_clear(&rack->r_ctl.rack_sf, th->th_ack);
16690 	}
16691 	if (thflags & TH_FIN)
16692 		tcp_log_end_status(tp, TCP_EI_STATUS_CLIENT_FIN);
16693 	us_cts = tcp_tv_to_usec(&rack->r_ctl.act_rcv_time);
16694 	if ((rack->rc_gp_dyn_mul) &&
16695 	    (rack->use_fixed_rate == 0) &&
16696 	    (rack->rc_always_pace)) {
16697 		/* Check in on probertt */
16698 		rack_check_probe_rtt(rack, cts);
16699 	}
16700 	rack_clear_rate_sample(rack);
16701 	if ((rack->forced_ack) &&
16702 	    ((tcp_get_flags(th) & TH_RST) == 0)) {
16703 		rack_handle_probe_response(rack, tiwin, us_cts);
16704 	}
16705 	/*
16706 	 * This is the one exception case where we set the rack state
16707 	 * always. All other times (timers etc) we must have a rack-state
16708 	 * set (so we assure we have done the checks above for SACK).
16709 	 */
16710 	rack->r_ctl.rc_rcvtime = cts;
16711 	if (rack->r_state != tp->t_state)
16712 		rack_set_state(tp, rack);
16713 	if (SEQ_GT(th->th_ack, tp->snd_una) &&
16714 	    (rsm = tqhash_min(rack->r_ctl.tqh)) != NULL)
16715 		kern_prefetch(rsm, &prev_state);
16716 	prev_state = rack->r_state;
16717 	if ((thflags & TH_RST) &&
16718 	    ((SEQ_GEQ(th->th_seq, tp->last_ack_sent) &&
16719 	      SEQ_LT(th->th_seq, tp->last_ack_sent + tp->rcv_wnd)) ||
16720 	     (tp->rcv_wnd == 0 && tp->last_ack_sent == th->th_seq))) {
16721 		/* The connection will be killed by a reset check the tracepoint */
16722 		tcp_trace_point(rack->rc_tp, TCP_TP_RESET_RCV);
16723 	}
16724 	retval = (*rack->r_substate) (m, th, so,
16725 	    tp, &to, drop_hdrlen,
16726 	    tlen, tiwin, thflags, nxt_pkt, iptos);
16727 	if (retval == 0) {
16728 		/*
16729 		 * If retval is 1 the tcb is unlocked and most likely the tp
16730 		 * is gone.
16731 		 */
16732 		INP_WLOCK_ASSERT(inp);
16733 		if ((rack->rc_gp_dyn_mul) &&
16734 		    (rack->rc_always_pace) &&
16735 		    (rack->use_fixed_rate == 0) &&
16736 		    rack->in_probe_rtt &&
16737 		    (rack->r_ctl.rc_time_probertt_starts == 0)) {
16738 			/*
16739 			 * If we are going for target, lets recheck before
16740 			 * we output.
16741 			 */
16742 			rack_check_probe_rtt(rack, cts);
16743 		}
16744 		if (rack->set_pacing_done_a_iw == 0) {
16745 			/* How much has been acked? */
16746 			if ((tp->snd_una - tp->iss) > (ctf_fixed_maxseg(tp) * 10)) {
16747 				/* We have enough to set in the pacing segment size */
16748 				rack->set_pacing_done_a_iw = 1;
16749 				rack_set_pace_segments(tp, rack, __LINE__, NULL);
16750 			}
16751 		}
16752 		tcp_rack_xmit_timer_commit(rack, tp);
16753 #ifdef TCP_ACCOUNTING
16754 		/*
16755 		 * If we set the ack_val_se to what ack processing we are doing
16756 		 * we also want to track how many cycles we burned. Note
16757 		 * the bits after tcp_output we let be "free". This is because
16758 		 * we are also tracking the tcp_output times as well. Note the
16759 		 * use of 0xf here since we only have 11 counter (0 - 0xa) and
16760 		 * 0xf cannot be returned and is what we initialize it too to
16761 		 * indicate we are not doing the tabulations.
16762 		 */
16763 		if (ack_val_set != 0xf) {
16764 			uint64_t crtsc;
16765 
16766 			crtsc = get_cyclecount();
16767 			if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
16768 				tp->tcp_proc_time[ack_val_set] += (crtsc - ts_val);
16769 			}
16770 		}
16771 #endif
16772 		if ((nxt_pkt == 0) && (no_output == 0)) {
16773 			if ((rack->r_wanted_output != 0) ||
16774 			    (tp->t_flags & TF_ACKNOW) ||
16775 			    (rack->r_fast_output != 0)) {
16776 
16777 do_output_now:
16778 				if (tcp_output(tp) < 0) {
16779 #ifdef TCP_ACCOUNTING
16780 					sched_unpin();
16781 #endif
16782 					return (1);
16783 				}
16784 				did_out = 1;
16785 			}
16786 			rack_start_hpts_timer(rack, tp, cts, 0, 0, 0);
16787 			rack_free_trim(rack);
16788 		} else if ((nxt_pkt == 0) && (tp->t_flags & TF_ACKNOW)) {
16789 			goto do_output_now;
16790 		} else if ((no_output == 1) &&
16791 			   (nxt_pkt == 0) &&
16792 			   (tcp_in_hpts(rack->rc_tp) == 0)) {
16793 			/*
16794 			 * We are not in hpts and we had a pacing timer up. Use
16795 			 * the remaining time (time_remaining) to restart the timer.
16796 			 */
16797 			KASSERT ((time_remaining != 0), ("slot remaining is zero for rack:%p tp:%p", rack, tp));
16798 			rack_start_hpts_timer(rack, tp, cts, time_remaining, 0, 0);
16799 			rack_free_trim(rack);
16800 		}
16801 		/* Clear the flag, it may have been cleared by output but we may not have  */
16802 		if ((nxt_pkt == 0) && (tp->t_flags2 & TF2_HPTS_CALLS))
16803 			tp->t_flags2 &= ~TF2_HPTS_CALLS;
16804 		/*
16805 		 * The draft (v3) calls for us to use SEQ_GEQ, but that
16806 		 * causes issues when we are just going app limited. Lets
16807 		 * instead use SEQ_GT <or> where its equal but more data
16808 		 * is outstanding.
16809 		 *
16810 		 * Also make sure we are on the last ack of a series. We
16811 		 * have to have all the ack's processed in queue to know
16812 		 * if there is something left outstanding.
16813 		 */
16814 		if (SEQ_GEQ(tp->snd_una, rack->r_ctl.roundends) &&
16815 		    (rack->rc_new_rnd_needed == 0) &&
16816 		    (nxt_pkt == 0)) {
16817 			/*
16818 			 * We have crossed into a new round with
16819 			 * the new snd_unae.
16820 			 */
16821 			rack_new_round_setup(tp, rack, tp->snd_una);
16822 		}
16823 		if ((nxt_pkt == 0) &&
16824 		    ((rack->r_ctl.rc_hpts_flags & PACE_TMR_MASK) == 0) &&
16825 		    (SEQ_GT(tp->snd_max, tp->snd_una) ||
16826 		     (tp->t_flags & TF_DELACK) ||
16827 		     ((V_tcp_always_keepalive || rack->rc_inp->inp_socket->so_options & SO_KEEPALIVE) &&
16828 		      (tp->t_state <= TCPS_CLOSING)))) {
16829 			/* We could not send (probably in the hpts but stopped the timer earlier)? */
16830 			if ((tp->snd_max == tp->snd_una) &&
16831 			    ((tp->t_flags & TF_DELACK) == 0) &&
16832 			    (tcp_in_hpts(rack->rc_tp)) &&
16833 			    (rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT)) {
16834 				/* keep alive not needed if we are hptsi output yet */
16835 				;
16836 			} else {
16837 				int late = 0;
16838 				if (tcp_in_hpts(tp)) {
16839 					if (rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT) {
16840 						us_cts = tcp_get_usecs(NULL);
16841 						if (TSTMP_GT(rack->r_ctl.rc_last_output_to, us_cts)) {
16842 							rack->r_early = 1;
16843 							rack->r_ctl.rc_agg_early += (rack->r_ctl.rc_last_output_to - us_cts);
16844 						} else
16845 							late = 1;
16846 						rack->r_ctl.rc_hpts_flags &= ~PACE_PKT_OUTPUT;
16847 					}
16848 					tcp_hpts_remove(tp);
16849 				}
16850 				if (late && (did_out == 0)) {
16851 					/*
16852 					 * We are late in the sending
16853 					 * and we did not call the output
16854 					 * (this probably should not happen).
16855 					 */
16856 					goto do_output_now;
16857 				}
16858 				rack_start_hpts_timer(rack, tp, tcp_get_usecs(NULL), 0, 0, 0);
16859 			}
16860 			way_out = 1;
16861 		} else if (nxt_pkt == 0) {
16862 			/* Do we have the correct timer running? */
16863 			rack_timer_audit(tp, rack, &so->so_snd);
16864 			way_out = 2;
16865 		}
16866 	done_with_input:
16867 		rack_log_doseg_done(rack, cts, nxt_pkt, did_out, way_out, max(1, nsegs));
16868 		if (did_out)
16869 			rack->r_wanted_output = 0;
16870 	}
16871 
16872 #ifdef TCP_ACCOUNTING
16873 	sched_unpin();
16874 #endif
16875 	return (retval);
16876 }
16877 
16878 static void
16879 rack_do_segment(struct tcpcb *tp, struct mbuf *m, struct tcphdr *th,
16880     int32_t drop_hdrlen, int32_t tlen, uint8_t iptos)
16881 {
16882 	struct timeval tv;
16883 
16884 	/* First lets see if we have old packets */
16885 	if (!STAILQ_EMPTY(&tp->t_inqueue)) {
16886 		if (ctf_do_queued_segments(tp, 1)) {
16887 			m_freem(m);
16888 			return;
16889 		}
16890 	}
16891 	if (m->m_flags & M_TSTMP_LRO) {
16892 		mbuf_tstmp2timeval(m, &tv);
16893 	} else {
16894 		/* Should not be should we kassert instead? */
16895 		tcp_get_usecs(&tv);
16896 	}
16897 	if (rack_do_segment_nounlock(tp, m, th, drop_hdrlen, tlen, iptos, 0,
16898 	    &tv) == 0) {
16899 		INP_WUNLOCK(tptoinpcb(tp));
16900 	}
16901 }
16902 
16903 struct rack_sendmap *
16904 tcp_rack_output(struct tcpcb *tp, struct tcp_rack *rack, uint32_t tsused)
16905 {
16906 	struct rack_sendmap *rsm = NULL;
16907 	int32_t idx;
16908 	uint32_t srtt = 0, thresh = 0, ts_low = 0;
16909 
16910 	/* Return the next guy to be re-transmitted */
16911 	if (tqhash_empty(rack->r_ctl.tqh)) {
16912 		return (NULL);
16913 	}
16914 	if (tp->t_flags & TF_SENTFIN) {
16915 		/* retran the end FIN? */
16916 		return (NULL);
16917 	}
16918 	/* ok lets look at this one */
16919 	rsm = TAILQ_FIRST(&rack->r_ctl.rc_tmap);
16920 	if (rack->r_must_retran && rsm && (rsm->r_flags & RACK_MUST_RXT)) {
16921 		return (rsm);
16922 	}
16923 	if (rsm && ((rsm->r_flags & RACK_ACKED) == 0)) {
16924 		goto check_it;
16925 	}
16926 	rsm = rack_find_lowest_rsm(rack);
16927 	if (rsm == NULL) {
16928 		return (NULL);
16929 	}
16930 check_it:
16931 	if (((rack->rc_tp->t_flags & TF_SACK_PERMIT) == 0) &&
16932 	    (rsm->r_dupack >= DUP_ACK_THRESHOLD)) {
16933 		/*
16934 		 * No sack so we automatically do the 3 strikes and
16935 		 * retransmit (no rack timer would be started).
16936 		 */
16937 		return (rsm);
16938 	}
16939 	if (rsm->r_flags & RACK_ACKED) {
16940 		return (NULL);
16941 	}
16942 	if (((rsm->r_flags & RACK_SACK_PASSED) == 0) &&
16943 	    (rsm->r_dupack < DUP_ACK_THRESHOLD)) {
16944 		/* Its not yet ready */
16945 		return (NULL);
16946 	}
16947 	srtt = rack_grab_rtt(tp, rack);
16948 	idx = rsm->r_rtr_cnt - 1;
16949 	ts_low = (uint32_t)rsm->r_tim_lastsent[idx];
16950 	thresh = rack_calc_thresh_rack(rack, srtt, tsused, __LINE__, 1);
16951 	if ((tsused == ts_low) ||
16952 	    (TSTMP_LT(tsused, ts_low))) {
16953 		/* No time since sending */
16954 		return (NULL);
16955 	}
16956 	if ((tsused - ts_low) < thresh) {
16957 		/* It has not been long enough yet */
16958 		return (NULL);
16959 	}
16960 	if ((rsm->r_dupack >= DUP_ACK_THRESHOLD) ||
16961 	    ((rsm->r_flags & RACK_SACK_PASSED))) {
16962 		/*
16963 		 * We have passed the dup-ack threshold <or>
16964 		 * a SACK has indicated this is missing.
16965 		 * Note that if you are a declared attacker
16966 		 * it is only the dup-ack threshold that
16967 		 * will cause retransmits.
16968 		 */
16969 		/* log retransmit reason */
16970 		rack_log_retran_reason(rack, rsm, (tsused - ts_low), thresh, 1);
16971 		rack->r_fast_output = 0;
16972 		return (rsm);
16973 	}
16974 	return (NULL);
16975 }
16976 
16977 static void
16978 rack_log_pacing_delay_calc (struct tcp_rack *rack, uint32_t len, uint32_t pacing_delay,
16979 			   uint64_t bw_est, uint64_t bw, uint64_t len_time, int method,
16980 			   int line, struct rack_sendmap *rsm, uint8_t quality)
16981 {
16982 	if (tcp_bblogging_on(rack->rc_tp)) {
16983 		union tcp_log_stackspecific log;
16984 		struct timeval tv;
16985 
16986 		if (rack_verbose_logging == 0) {
16987 			/*
16988 			 * We are not verbose screen out all but
16989 			 * ones we always want.
16990 			 */
16991 			if ((method != 2) &&
16992 			    (method != 3) &&
16993 			    (method != 7) &&
16994 			    (method != 89) &&
16995 			    (method != 14) &&
16996 			    (method != 20)) {
16997 				return;
16998 			}
16999 		}
17000 		memset(&log, 0, sizeof(log));
17001 		log.u_bbr.flex1 = pacing_delay;
17002 		log.u_bbr.flex2 = len;
17003 		log.u_bbr.flex3 = rack->r_ctl.rc_pace_min_segs;
17004 		log.u_bbr.flex4 = rack->r_ctl.rc_pace_max_segs;
17005 		log.u_bbr.flex5 = rack->r_ctl.rack_per_of_gp_ss;
17006 		log.u_bbr.flex6 = rack->r_ctl.rack_per_of_gp_ca;
17007 		log.u_bbr.use_lt_bw = rack->rc_ack_can_sendout_data;
17008 		log.u_bbr.use_lt_bw <<= 1;
17009 		log.u_bbr.use_lt_bw |= rack->r_late;
17010 		log.u_bbr.use_lt_bw <<= 1;
17011 		log.u_bbr.use_lt_bw |= rack->r_early;
17012 		log.u_bbr.use_lt_bw <<= 1;
17013 		log.u_bbr.use_lt_bw |= rack->app_limited_needs_set;
17014 		log.u_bbr.use_lt_bw <<= 1;
17015 		log.u_bbr.use_lt_bw |= rack->rc_gp_filled;
17016 		log.u_bbr.use_lt_bw <<= 1;
17017 		log.u_bbr.use_lt_bw |= rack->measure_saw_probe_rtt;
17018 		log.u_bbr.use_lt_bw <<= 1;
17019 		log.u_bbr.use_lt_bw |= rack->in_probe_rtt;
17020 		log.u_bbr.use_lt_bw <<= 1;
17021 		log.u_bbr.use_lt_bw |= rack->gp_ready;
17022 		log.u_bbr.pkt_epoch = line;
17023 		log.u_bbr.epoch = rack->r_ctl.rc_agg_delayed;
17024 		log.u_bbr.lt_epoch = rack->r_ctl.rc_agg_early;
17025 		log.u_bbr.applimited = rack->r_ctl.rack_per_of_gp_rec;
17026 		log.u_bbr.bw_inuse = bw_est;
17027 		log.u_bbr.delRate = bw;
17028 		if (rack->r_ctl.gp_bw == 0)
17029 			log.u_bbr.cur_del_rate = 0;
17030 		else
17031 			log.u_bbr.cur_del_rate = rack_get_bw(rack);
17032 		log.u_bbr.rttProp = len_time;
17033 		log.u_bbr.pkts_out = rack->r_ctl.rc_rack_min_rtt;
17034 		log.u_bbr.lost = rack->r_ctl.rc_probertt_sndmax_atexit;
17035 		log.u_bbr.pacing_gain = rack_get_output_gain(rack, rsm);
17036 		if (rack->r_ctl.cwnd_to_use < rack->rc_tp->snd_ssthresh) {
17037 			/* We are in slow start */
17038 			log.u_bbr.flex7 = 1;
17039 		} else {
17040 			/* we are on congestion avoidance */
17041 			log.u_bbr.flex7 = 0;
17042 		}
17043 		log.u_bbr.flex8 = method;
17044 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
17045 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
17046 		log.u_bbr.cwnd_gain = rack->rc_gp_saw_rec;
17047 		log.u_bbr.cwnd_gain <<= 1;
17048 		log.u_bbr.cwnd_gain |= rack->rc_gp_saw_ss;
17049 		log.u_bbr.cwnd_gain <<= 1;
17050 		log.u_bbr.cwnd_gain |= rack->rc_gp_saw_ca;
17051 		log.u_bbr.cwnd_gain <<= 1;
17052 		log.u_bbr.cwnd_gain |= rack->use_fixed_rate;
17053 		log.u_bbr.cwnd_gain <<= 1;
17054 		log.u_bbr.cwnd_gain |= rack->rc_always_pace;
17055 		log.u_bbr.cwnd_gain <<= 1;
17056 		log.u_bbr.cwnd_gain |= rack->gp_ready;
17057 		log.u_bbr.bbr_substate = quality;
17058 		log.u_bbr.bbr_state = rack->dgp_on;
17059 		log.u_bbr.bbr_state <<= 1;
17060 		log.u_bbr.bbr_state |= rack->rc_pace_to_cwnd;
17061 		log.u_bbr.bbr_state <<= 2;
17062 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
17063 		    &rack->rc_inp->inp_socket->so_rcv,
17064 		    &rack->rc_inp->inp_socket->so_snd,
17065 		    BBR_LOG_HPTSI_CALC, 0,
17066 		    0, &log, false, &tv);
17067 	}
17068 }
17069 
17070 static uint32_t
17071 rack_get_pacing_len(struct tcp_rack *rack, uint64_t bw, uint32_t mss)
17072 {
17073 	uint32_t new_tso, user_max, pace_one;
17074 
17075 	user_max = rack->rc_user_set_max_segs * mss;
17076 	if (rack->rc_force_max_seg) {
17077 		return (user_max);
17078 	}
17079 	if (rack->use_fixed_rate &&
17080 	    ((rack->r_ctl.crte == NULL) ||
17081 	     (bw != rack->r_ctl.crte->rate))) {
17082 		/* Use the user mss since we are not exactly matched */
17083 		return (user_max);
17084 	}
17085 	if (rack_pace_one_seg ||
17086 	    (rack->r_ctl.rc_user_set_min_segs == 1))
17087 		pace_one = 1;
17088 	else
17089 		pace_one = 0;
17090 
17091 	new_tso = tcp_get_pacing_burst_size_w_divisor(rack->rc_tp, bw, mss,
17092 		     pace_one, rack->r_ctl.crte, NULL, rack->r_ctl.pace_len_divisor);
17093 	if (new_tso > user_max)
17094 		new_tso = user_max;
17095 	if (rack->rc_hybrid_mode && rack->r_ctl.client_suggested_maxseg) {
17096 		if (((uint32_t)rack->r_ctl.client_suggested_maxseg * mss) > new_tso)
17097 			new_tso = (uint32_t)rack->r_ctl.client_suggested_maxseg * mss;
17098 	}
17099 	if (rack->r_ctl.rc_user_set_min_segs &&
17100 	    ((rack->r_ctl.rc_user_set_min_segs * mss) > new_tso))
17101 	    new_tso = rack->r_ctl.rc_user_set_min_segs * mss;
17102 	return (new_tso);
17103 }
17104 
17105 static uint64_t
17106 rack_arrive_at_discounted_rate(struct tcp_rack *rack, uint64_t window_input, uint32_t *rate_set, uint32_t *gain_b)
17107 {
17108 	uint64_t reduced_win;
17109 	uint32_t gain;
17110 
17111 	if (window_input < rc_init_window(rack)) {
17112 		/*
17113 		 * The cwnd is collapsed to
17114 		 * nearly zero, maybe because of a time-out?
17115 		 * Lets drop back to the lt-bw.
17116 		 */
17117 		reduced_win = rack_get_lt_bw(rack);
17118 		/* Set the flag so the caller knows its a rate and not a reduced window */
17119 		*rate_set = 1;
17120 		gain = 100;
17121 	} else if  (IN_RECOVERY(rack->rc_tp->t_flags)) {
17122 		/*
17123 		 * If we are in recover our cwnd needs to be less for
17124 		 * our pacing consideration.
17125 		 */
17126 		if (rack->rack_hibeta == 0) {
17127 			reduced_win = window_input / 2;
17128 			gain = 50;
17129 		} else {
17130 			reduced_win = window_input * rack->r_ctl.saved_hibeta;
17131 			reduced_win /= 100;
17132 			gain = rack->r_ctl.saved_hibeta;
17133 		}
17134 	} else {
17135 		/*
17136 		 * Apply Timely factor to increase/decrease the
17137 		 * amount we are pacing at.
17138 		 */
17139 		gain = rack_get_output_gain(rack, NULL);
17140 		if (gain > rack_gain_p5_ub) {
17141 			gain = rack_gain_p5_ub;
17142 		}
17143 		reduced_win = window_input * gain;
17144 		reduced_win /= 100;
17145 	}
17146 	if (gain_b != NULL)
17147 		*gain_b = gain;
17148 	/*
17149 	 * What is being returned here is a trimmed down
17150 	 * window values in all cases where rate_set is left
17151 	 * at 0. In one case we actually return the rate (lt_bw).
17152 	 * the "reduced_win" is returned as a slimmed down cwnd that
17153 	 * is then calculated by the caller into a rate when rate_set
17154 	 * is 0.
17155 	 */
17156 	return (reduced_win);
17157 }
17158 
17159 static int32_t
17160 pace_to_fill_cwnd(struct tcp_rack *rack, int32_t pacing_delay, uint32_t len, uint32_t segsiz, int *capped, uint64_t *rate_wanted, uint8_t non_paced)
17161 {
17162 	uint64_t lentim, fill_bw;
17163 
17164 	rack->r_via_fill_cw = 0;
17165 	if (ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked) > rack->r_ctl.cwnd_to_use)
17166 		return (pacing_delay);
17167 	if ((ctf_outstanding(rack->rc_tp) + (segsiz-1)) > rack->rc_tp->snd_wnd)
17168 		return (pacing_delay);
17169 	if (rack->r_ctl.rc_last_us_rtt == 0)
17170 		return (pacing_delay);
17171 	if (rack->rc_pace_fill_if_rttin_range &&
17172 	    (rack->r_ctl.rc_last_us_rtt >=
17173 	     (get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt) * rack->rtt_limit_mul))) {
17174 		/* The rtt is huge, N * smallest, lets not fill */
17175 		return (pacing_delay);
17176 	}
17177 	if (rack->r_ctl.fillcw_cap && *rate_wanted >= rack->r_ctl.fillcw_cap)
17178 		return (pacing_delay);
17179 	/*
17180 	 * first lets calculate the b/w based on the last us-rtt
17181 	 * and the the smallest send window.
17182 	 */
17183 	fill_bw = min(rack->rc_tp->snd_cwnd, rack->r_ctl.cwnd_to_use);
17184 	if (rack->rc_fillcw_apply_discount) {
17185 		uint32_t rate_set = 0;
17186 
17187 		fill_bw = rack_arrive_at_discounted_rate(rack, fill_bw, &rate_set, NULL);
17188 		if (rate_set) {
17189 			goto at_lt_bw;
17190 		}
17191 	}
17192 	/* Take the rwnd if its smaller */
17193 	if (fill_bw > rack->rc_tp->snd_wnd)
17194 		fill_bw = rack->rc_tp->snd_wnd;
17195 	/* Now lets make it into a b/w */
17196 	fill_bw *= (uint64_t)HPTS_USEC_IN_SEC;
17197 	fill_bw /= (uint64_t)rack->r_ctl.rc_last_us_rtt;
17198 	/* Adjust to any cap */
17199 	if (rack->r_ctl.fillcw_cap && fill_bw >= rack->r_ctl.fillcw_cap)
17200 		fill_bw = rack->r_ctl.fillcw_cap;
17201 
17202 at_lt_bw:
17203 	if (rack_bw_multipler > 0) {
17204 		/*
17205 		 * We want to limit fill-cw to the some multiplier
17206 		 * of the max(lt_bw, gp_est). The normal default
17207 		 * is 0 for off, so a sysctl has enabled it.
17208 		 */
17209 		uint64_t lt_bw, gp, rate;
17210 
17211 		gp = rack_get_gp_est(rack);
17212 		lt_bw = rack_get_lt_bw(rack);
17213 		if (lt_bw > gp)
17214 			rate = lt_bw;
17215 		else
17216 			rate = gp;
17217 		rate *= rack_bw_multipler;
17218 		rate /= 100;
17219 		if (rack_verbose_logging && tcp_bblogging_on(rack->rc_tp)) {
17220 			union tcp_log_stackspecific log;
17221 			struct timeval tv;
17222 
17223 			memset(&log, 0, sizeof(log));
17224 			log.u_bbr.timeStamp = tcp_get_usecs(&tv);
17225 			log.u_bbr.flex1 = rack_bw_multipler;
17226 			log.u_bbr.flex2 = len;
17227 			log.u_bbr.cur_del_rate = gp;
17228 			log.u_bbr.delRate = lt_bw;
17229 			log.u_bbr.bw_inuse = rate;
17230 			log.u_bbr.rttProp = fill_bw;
17231 			log.u_bbr.flex8 = 44;
17232 			tcp_log_event(rack->rc_tp, NULL, NULL, NULL,
17233 				      BBR_LOG_CWND, 0,
17234 				      0, &log, false, NULL,
17235 				      __func__, __LINE__, &tv);
17236 		}
17237 		if (fill_bw > rate)
17238 			fill_bw = rate;
17239 	}
17240 	/* We are below the min b/w */
17241 	if (non_paced)
17242 		*rate_wanted = fill_bw;
17243 	if ((fill_bw < RACK_MIN_BW) || (fill_bw < *rate_wanted))
17244 		return (pacing_delay);
17245 	rack->r_via_fill_cw = 1;
17246 	if (rack->r_rack_hw_rate_caps &&
17247 	    (rack->r_ctl.crte != NULL)) {
17248 		uint64_t high_rate;
17249 
17250 		high_rate = tcp_hw_highest_rate(rack->r_ctl.crte);
17251 		if (fill_bw > high_rate) {
17252 			/* We are capping bw at the highest rate table entry */
17253 			if (*rate_wanted > high_rate) {
17254 				/* The original rate was also capped */
17255 				rack->r_via_fill_cw = 0;
17256 			}
17257 			rack_log_hdwr_pacing(rack,
17258 					     fill_bw, high_rate, __LINE__,
17259 					     0, 3);
17260 			fill_bw = high_rate;
17261 			if (capped)
17262 				*capped = 1;
17263 		}
17264 	} else if ((rack->r_ctl.crte == NULL) &&
17265 		   (rack->rack_hdrw_pacing == 0) &&
17266 		   (rack->rack_hdw_pace_ena) &&
17267 		   rack->r_rack_hw_rate_caps &&
17268 		   (rack->rack_attempt_hdwr_pace == 0) &&
17269 		   (rack->rc_inp->inp_route.ro_nh != NULL) &&
17270 		   (rack->rc_inp->inp_route.ro_nh->nh_ifp != NULL)) {
17271 		/*
17272 		 * Ok we may have a first attempt that is greater than our top rate
17273 		 * lets check.
17274 		 */
17275 		uint64_t high_rate;
17276 
17277 		high_rate = tcp_hw_highest_rate_ifp(rack->rc_inp->inp_route.ro_nh->nh_ifp, rack->rc_inp);
17278 		if (high_rate) {
17279 			if (fill_bw > high_rate) {
17280 				fill_bw = high_rate;
17281 				if (capped)
17282 					*capped = 1;
17283 			}
17284 		}
17285 	}
17286 	if (rack->r_ctl.bw_rate_cap && (fill_bw > rack->r_ctl.bw_rate_cap)) {
17287 		rack_log_hybrid_bw(rack, rack->rc_tp->snd_max,
17288 				   fill_bw, 0, 0, HYBRID_LOG_RATE_CAP, 2, NULL, __LINE__);
17289 		fill_bw = rack->r_ctl.bw_rate_cap;
17290 	}
17291 	/*
17292 	 * Ok fill_bw holds our mythical b/w to fill the cwnd
17293 	 * in an rtt (unless it was capped), what does that
17294 	 * time wise equate too?
17295 	 */
17296 	lentim = (uint64_t)(len) * (uint64_t)HPTS_USEC_IN_SEC;
17297 	lentim /= fill_bw;
17298 	*rate_wanted = fill_bw;
17299 	if (non_paced || (lentim < pacing_delay)) {
17300 		rack_log_pacing_delay_calc(rack, len, pacing_delay, fill_bw,
17301 					   0, lentim, 12, __LINE__, NULL, 0);
17302 		return ((int32_t)lentim);
17303 	} else
17304 		return (pacing_delay);
17305 }
17306 
17307 static int32_t
17308 rack_get_pacing_delay(struct tcp_rack *rack, struct tcpcb *tp, uint32_t len, struct rack_sendmap *rsm, uint32_t segsiz, int line)
17309 {
17310 	uint64_t srtt;
17311 	int32_t pacing_delay = 0;
17312 	int can_start_hw_pacing = 1;
17313 	int err;
17314 	int pace_one;
17315 
17316 	if (rack_pace_one_seg ||
17317 	    (rack->r_ctl.rc_user_set_min_segs == 1))
17318 		pace_one = 1;
17319 	else
17320 		pace_one = 0;
17321 	if (rack->rc_always_pace == 0) {
17322 		/*
17323 		 * We use the most optimistic possible cwnd/srtt for
17324 		 * sending calculations. This will make our
17325 		 * calculation anticipate getting more through
17326 		 * quicker then possible. But thats ok we don't want
17327 		 * the peer to have a gap in data sending.
17328 		 */
17329 		uint64_t cwnd, tr_perms = 0;
17330 		int32_t reduce;
17331 
17332 	old_method:
17333 		/*
17334 		 * We keep no precise pacing with the old method
17335 		 * instead we use the pacer to mitigate bursts.
17336 		 */
17337 		if (rack->r_ctl.rc_rack_min_rtt)
17338 			srtt = rack->r_ctl.rc_rack_min_rtt;
17339 		else
17340 			srtt = max(tp->t_srtt, 1);
17341 		if (rack->r_ctl.rc_rack_largest_cwnd)
17342 			cwnd = rack->r_ctl.rc_rack_largest_cwnd;
17343 		else
17344 			cwnd = rack->r_ctl.cwnd_to_use;
17345 		/* Inflate cwnd by 1000 so srtt of usecs is in ms */
17346 		tr_perms = (cwnd * 1000) / srtt;
17347 		if (tr_perms == 0) {
17348 			tr_perms = ctf_fixed_maxseg(tp);
17349 		}
17350 		/*
17351 		 * Calculate how long this will take to drain, if
17352 		 * the calculation comes out to zero, thats ok we
17353 		 * will use send_a_lot to possibly spin around for
17354 		 * more increasing tot_len_this_send to the point
17355 		 * that its going to require a pace, or we hit the
17356 		 * cwnd. Which in that case we are just waiting for
17357 		 * a ACK.
17358 		 */
17359 		pacing_delay = len / tr_perms;
17360 		/* Now do we reduce the time so we don't run dry? */
17361 		if (pacing_delay && rack_pacing_delay_reduction) {
17362 			reduce = (pacing_delay / rack_pacing_delay_reduction);
17363 			if (reduce < pacing_delay) {
17364 				pacing_delay -= reduce;
17365 			} else
17366 				pacing_delay = 0;
17367 		} else
17368 			reduce = 0;
17369 		pacing_delay *= HPTS_USEC_IN_MSEC;
17370 		if (rack->rc_pace_to_cwnd) {
17371 			uint64_t rate_wanted = 0;
17372 
17373 			pacing_delay = pace_to_fill_cwnd(rack, pacing_delay, len, segsiz, NULL, &rate_wanted, 1);
17374 			rack->rc_ack_can_sendout_data = 1;
17375 			rack_log_pacing_delay_calc(rack, len, pacing_delay, rate_wanted, 0, 0, 14, __LINE__, NULL, 0);
17376 		} else
17377 			rack_log_pacing_delay_calc(rack, len, pacing_delay, tr_perms, reduce, 0, 7, __LINE__, NULL, 0);
17378 		/*******************************************************/
17379 		/* RRS: We insert non-paced call to stats here for len */
17380 		/*******************************************************/
17381 	} else {
17382 		uint64_t bw_est, res, lentim, rate_wanted;
17383 		uint32_t segs, oh;
17384 		int capped = 0;
17385 		int prev_fill;
17386 
17387 		if ((rack->r_rr_config == 1) && rsm) {
17388 			return (rack->r_ctl.rc_min_to);
17389 		}
17390 		if (rack->use_fixed_rate) {
17391 			rate_wanted = bw_est = rack_get_fixed_pacing_bw(rack);
17392 		} else if ((rack->r_ctl.init_rate == 0) &&
17393 			   (rack->r_ctl.gp_bw == 0)) {
17394 			/* no way to yet do an estimate */
17395 			bw_est = rate_wanted = 0;
17396 		} else if (rack->dgp_on) {
17397 			bw_est = rack_get_bw(rack);
17398 			rate_wanted = rack_get_output_bw(rack, bw_est, rsm, &capped);
17399 		} else {
17400 			uint32_t gain, rate_set = 0;
17401 
17402 			rate_wanted = min(rack->rc_tp->snd_cwnd, rack->r_ctl.cwnd_to_use);
17403 			rate_wanted = rack_arrive_at_discounted_rate(rack, rate_wanted, &rate_set, &gain);
17404 			if (rate_set == 0) {
17405 				if (rate_wanted > rack->rc_tp->snd_wnd)
17406 					rate_wanted = rack->rc_tp->snd_wnd;
17407 				/* Now lets make it into a b/w */
17408 				rate_wanted *= (uint64_t)HPTS_USEC_IN_SEC;
17409 				rate_wanted /= (uint64_t)rack->r_ctl.rc_last_us_rtt;
17410 			}
17411 			bw_est = rate_wanted;
17412 			rack_log_pacing_delay_calc(rack, rack->rc_tp->snd_cwnd,
17413 						   rack->r_ctl.cwnd_to_use,
17414 						   rate_wanted, bw_est,
17415 						   rack->r_ctl.rc_last_us_rtt,
17416 						   88, __LINE__, NULL, gain);
17417 		}
17418 		if (((bw_est == 0) || (rate_wanted == 0) || (rack->gp_ready == 0)) &&
17419 		    (rack->use_fixed_rate == 0)) {
17420 			/*
17421 			 * No way yet to make a b/w estimate or
17422 			 * our raise is set incorrectly.
17423 			 */
17424 			goto old_method;
17425 		}
17426 		rack_rate_cap_bw(rack, &rate_wanted, &capped);
17427 		/* We need to account for all the overheads */
17428 		segs = (len + segsiz - 1) / segsiz;
17429 		/*
17430 		 * We need the diff between 1514 bytes (e-mtu with e-hdr)
17431 		 * and how much data we put in each packet. Yes this
17432 		 * means we may be off if we are larger than 1500 bytes
17433 		 * or smaller. But this just makes us more conservative.
17434 		 */
17435 
17436 		oh =  (tp->t_maxseg - segsiz) + sizeof(struct tcphdr);
17437 		if (rack->r_is_v6) {
17438 #ifdef INET6
17439 			oh += sizeof(struct ip6_hdr);
17440 #endif
17441 		} else {
17442 #ifdef INET
17443 			oh += sizeof(struct ip);
17444 #endif
17445 		}
17446 		/* We add a fixed 14 for the ethernet header */
17447 		oh += 14;
17448 		segs *= oh;
17449 		lentim = (uint64_t)(len + segs) * (uint64_t)HPTS_USEC_IN_SEC;
17450 		res = lentim / rate_wanted;
17451 		pacing_delay = (uint32_t)res;
17452 		if (rack_hw_rate_min &&
17453 		    (rate_wanted < rack_hw_rate_min)) {
17454 			can_start_hw_pacing = 0;
17455 			if (rack->r_ctl.crte) {
17456 				/*
17457 				 * Ok we need to release it, we
17458 				 * have fallen too low.
17459 				 */
17460 				tcp_rel_pacing_rate(rack->r_ctl.crte, rack->rc_tp);
17461 				rack->r_ctl.crte = NULL;
17462 				rack->rack_attempt_hdwr_pace = 0;
17463 				rack->rack_hdrw_pacing = 0;
17464 			}
17465 		}
17466 		if (rack->r_ctl.crte &&
17467 		    (tcp_hw_highest_rate(rack->r_ctl.crte) < rate_wanted)) {
17468 			/*
17469 			 * We want more than the hardware can give us,
17470 			 * don't start any hw pacing.
17471 			 */
17472 			can_start_hw_pacing = 0;
17473 			if (rack->r_rack_hw_rate_caps == 0) {
17474 				/*
17475 				 * Ok we need to release it, we
17476 				 * want more than the card can give us and
17477 				 * no rate cap is in place. Set it up so
17478 				 * when we want less we can retry.
17479 				 */
17480 				tcp_rel_pacing_rate(rack->r_ctl.crte, rack->rc_tp);
17481 				rack->r_ctl.crte = NULL;
17482 				rack->rack_attempt_hdwr_pace = 0;
17483 				rack->rack_hdrw_pacing = 0;
17484 			}
17485 		}
17486 		if ((rack->r_ctl.crte != NULL) && (rack->rc_inp->inp_snd_tag == NULL)) {
17487 			/*
17488 			 * We lost our rate somehow, this can happen
17489 			 * if the interface changed underneath us.
17490 			 */
17491 			tcp_rel_pacing_rate(rack->r_ctl.crte, rack->rc_tp);
17492 			rack->r_ctl.crte = NULL;
17493 			/* Lets re-allow attempting to setup pacing */
17494 			rack->rack_hdrw_pacing = 0;
17495 			rack->rack_attempt_hdwr_pace = 0;
17496 			rack_log_hdwr_pacing(rack,
17497 					     rate_wanted, bw_est, __LINE__,
17498 					     0, 6);
17499 		}
17500 		prev_fill = rack->r_via_fill_cw;
17501 		if ((rack->rc_pace_to_cwnd) &&
17502 		    (capped == 0) &&
17503 		    (rack->dgp_on == 1) &&
17504 		    (rack->use_fixed_rate == 0) &&
17505 		    (rack->in_probe_rtt == 0) &&
17506 		    (IN_FASTRECOVERY(rack->rc_tp->t_flags) == 0)) {
17507 			/*
17508 			 * We want to pace at our rate *or* faster to
17509 			 * fill the cwnd to the max if its not full.
17510 			 */
17511 			pacing_delay = pace_to_fill_cwnd(rack, pacing_delay, (len+segs), segsiz, &capped, &rate_wanted, 0);
17512 			/* Re-check to make sure we are not exceeding our max b/w */
17513 			if ((rack->r_ctl.crte != NULL) &&
17514 			    (tcp_hw_highest_rate(rack->r_ctl.crte) < rate_wanted)) {
17515 				/*
17516 				 * We want more than the hardware can give us,
17517 				 * don't start any hw pacing.
17518 				 */
17519 				can_start_hw_pacing = 0;
17520 				if (rack->r_rack_hw_rate_caps == 0) {
17521 					/*
17522 					 * Ok we need to release it, we
17523 					 * want more than the card can give us and
17524 					 * no rate cap is in place. Set it up so
17525 					 * when we want less we can retry.
17526 					 */
17527 					tcp_rel_pacing_rate(rack->r_ctl.crte, rack->rc_tp);
17528 					rack->r_ctl.crte = NULL;
17529 					rack->rack_attempt_hdwr_pace = 0;
17530 					rack->rack_hdrw_pacing = 0;
17531 					rack_set_pace_segments(rack->rc_tp, rack, __LINE__, NULL);
17532 				}
17533 			}
17534 		}
17535 		if ((rack->rc_inp->inp_route.ro_nh != NULL) &&
17536 		    (rack->rc_inp->inp_route.ro_nh->nh_ifp != NULL)) {
17537 			if ((rack->rack_hdw_pace_ena) &&
17538 			    (can_start_hw_pacing > 0) &&
17539 			    (rack->rack_hdrw_pacing == 0) &&
17540 			    (rack->rack_attempt_hdwr_pace == 0)) {
17541 				/*
17542 				 * Lets attempt to turn on hardware pacing
17543 				 * if we can.
17544 				 */
17545 				rack->rack_attempt_hdwr_pace = 1;
17546 				rack->r_ctl.crte = tcp_set_pacing_rate(rack->rc_tp,
17547 								       rack->rc_inp->inp_route.ro_nh->nh_ifp,
17548 								       rate_wanted,
17549 								       RS_PACING_GEQ,
17550 								       &err, &rack->r_ctl.crte_prev_rate);
17551 				if (rack->r_ctl.crte) {
17552 					rack->rack_hdrw_pacing = 1;
17553 					rack->r_ctl.rc_pace_max_segs = tcp_get_pacing_burst_size_w_divisor(tp, rate_wanted, segsiz,
17554 													   pace_one, rack->r_ctl.crte,
17555 													   NULL, rack->r_ctl.pace_len_divisor);
17556 					rack_log_hdwr_pacing(rack,
17557 							     rate_wanted, rack->r_ctl.crte->rate, __LINE__,
17558 							     err, 0);
17559 					rack->r_ctl.last_hw_bw_req = rate_wanted;
17560 				} else {
17561 					counter_u64_add(rack_hw_pace_init_fail, 1);
17562 				}
17563 			} else if (rack->rack_hdrw_pacing &&
17564 				   (rack->r_ctl.last_hw_bw_req != rate_wanted)) {
17565 				/* Do we need to adjust our rate? */
17566 				const struct tcp_hwrate_limit_table *nrte;
17567 
17568 				if (rack->r_up_only &&
17569 				    (rate_wanted < rack->r_ctl.crte->rate)) {
17570 					/**
17571 					 * We have four possible states here
17572 					 * having to do with the previous time
17573 					 * and this time.
17574 					 *   previous  |  this-time
17575 					 * A)     0      |     0   -- fill_cw not in the picture
17576 					 * B)     1      |     0   -- we were doing a fill-cw but now are not
17577 					 * C)     1      |     1   -- all rates from fill_cw
17578 					 * D)     0      |     1   -- we were doing non-fill and now we are filling
17579 					 *
17580 					 * For case A, C and D we don't allow a drop. But for
17581 					 * case B where we now our on our steady rate we do
17582 					 * allow a drop.
17583 					 *
17584 					 */
17585 					if (!((prev_fill == 1) && (rack->r_via_fill_cw == 0)))
17586 						goto done_w_hdwr;
17587 				}
17588 				if ((rate_wanted > rack->r_ctl.crte->rate) ||
17589 				    (rate_wanted <= rack->r_ctl.crte_prev_rate)) {
17590 					if (rack_hw_rate_to_low &&
17591 					    (bw_est < rack_hw_rate_to_low)) {
17592 						/*
17593 						 * The pacing rate is too low for hardware, but
17594 						 * do allow hardware pacing to be restarted.
17595 						 */
17596 						rack_log_hdwr_pacing(rack,
17597 								     bw_est, rack->r_ctl.crte->rate, __LINE__,
17598 								     0, 5);
17599 						tcp_rel_pacing_rate(rack->r_ctl.crte, rack->rc_tp);
17600 						rack->r_ctl.crte = NULL;
17601 						rack->rack_attempt_hdwr_pace = 0;
17602 						rack->rack_hdrw_pacing = 0;
17603 						rack_set_pace_segments(rack->rc_tp, rack, __LINE__, &rate_wanted);
17604 						goto done_w_hdwr;
17605 					}
17606 					nrte = tcp_chg_pacing_rate(rack->r_ctl.crte,
17607 								   rack->rc_tp,
17608 								   rack->rc_inp->inp_route.ro_nh->nh_ifp,
17609 								   rate_wanted,
17610 								   RS_PACING_GEQ,
17611 								   &err, &rack->r_ctl.crte_prev_rate);
17612 					if (nrte == NULL) {
17613 						/*
17614 						 * Lost the rate, lets drop hardware pacing
17615 						 * period.
17616 						 */
17617 						rack->rack_hdrw_pacing = 0;
17618 						rack->r_ctl.crte = NULL;
17619 						rack_log_hdwr_pacing(rack,
17620 								     rate_wanted, 0, __LINE__,
17621 								     err, 1);
17622 						rack_set_pace_segments(rack->rc_tp, rack, __LINE__, &rate_wanted);
17623 						counter_u64_add(rack_hw_pace_lost, 1);
17624 					} else if (nrte != rack->r_ctl.crte) {
17625 						rack->r_ctl.crte = nrte;
17626 						rack->r_ctl.rc_pace_max_segs = tcp_get_pacing_burst_size_w_divisor(tp, rate_wanted,
17627 														   segsiz, pace_one, rack->r_ctl.crte,
17628 														   NULL, rack->r_ctl.pace_len_divisor);
17629 						rack_log_hdwr_pacing(rack,
17630 								     rate_wanted, rack->r_ctl.crte->rate, __LINE__,
17631 								     err, 2);
17632 						rack->r_ctl.last_hw_bw_req = rate_wanted;
17633 					}
17634 				} else {
17635 					/* We just need to adjust the segment size */
17636 					rack_set_pace_segments(rack->rc_tp, rack, __LINE__, &rate_wanted);
17637 					rack_log_hdwr_pacing(rack,
17638 							     rate_wanted, rack->r_ctl.crte->rate, __LINE__,
17639 							     0, 4);
17640 					rack->r_ctl.last_hw_bw_req = rate_wanted;
17641 				}
17642 			}
17643 		}
17644 	done_w_hdwr:
17645 		if (rack_limit_time_with_srtt &&
17646 		    (rack->use_fixed_rate == 0) &&
17647 		    (rack->rack_hdrw_pacing == 0)) {
17648 			/*
17649 			 * Sanity check, we do not allow the pacing delay
17650 			 * to be longer than the SRTT of the path. If it is
17651 			 * a slow path, then adding a packet should increase
17652 			 * the RTT and compensate for this i.e. the srtt will
17653 			 * be greater so the allowed pacing time will be greater.
17654 			 *
17655 			 * Note this restriction is not for where a peak rate
17656 			 * is set, we are doing fixed pacing or hardware pacing.
17657 			 */
17658 			if (rack->rc_tp->t_srtt)
17659 				srtt = rack->rc_tp->t_srtt;
17660 			else
17661 				srtt = RACK_INITIAL_RTO * HPTS_USEC_IN_MSEC;	/* its in ms convert */
17662 			if (srtt < (uint64_t)pacing_delay) {
17663 				rack_log_pacing_delay_calc(rack, srtt, pacing_delay, rate_wanted, bw_est, lentim, 99, __LINE__, NULL, 0);
17664 				pacing_delay = srtt;
17665 			}
17666 		}
17667 		/*******************************************************************/
17668 		/* RRS: We insert paced call to stats here for len and rate_wanted */
17669 		/*******************************************************************/
17670 		rack_log_pacing_delay_calc(rack, len, pacing_delay, rate_wanted, bw_est, lentim, 2, __LINE__, rsm, 0);
17671 	}
17672 	if (rack->r_ctl.crte && (rack->r_ctl.crte->rs_num_enobufs > 0)) {
17673 		/*
17674 		 * If this rate is seeing enobufs when it
17675 		 * goes to send then either the nic is out
17676 		 * of gas or we are mis-estimating the time
17677 		 * somehow and not letting the queue empty
17678 		 * completely. Lets add to the pacing time.
17679 		 */
17680 		int hw_boost_delay;
17681 
17682 		hw_boost_delay = rack->r_ctl.crte->time_between * rack_enobuf_hw_boost_mult;
17683 		if (hw_boost_delay > rack_enobuf_hw_max)
17684 			hw_boost_delay = rack_enobuf_hw_max;
17685 		else if (hw_boost_delay < rack_enobuf_hw_min)
17686 			hw_boost_delay = rack_enobuf_hw_min;
17687 		pacing_delay += hw_boost_delay;
17688 	}
17689 	return (pacing_delay);
17690 }
17691 
17692 static void
17693 rack_start_gp_measurement(struct tcpcb *tp, struct tcp_rack *rack,
17694     tcp_seq startseq, uint32_t sb_offset)
17695 {
17696 	struct rack_sendmap *my_rsm = NULL;
17697 
17698 	if (tp->t_state < TCPS_ESTABLISHED) {
17699 		/*
17700 		 * We don't start any measurements if we are
17701 		 * not at least established.
17702 		 */
17703 		return;
17704 	}
17705 	if (tp->t_state >= TCPS_FIN_WAIT_1) {
17706 		/*
17707 		 * We will get no more data into the SB
17708 		 * this means we need to have the data available
17709 		 * before we start a measurement.
17710 		 */
17711 
17712 		if (sbavail(&tptosocket(tp)->so_snd) <
17713 		    max(rc_init_window(rack),
17714 			(MIN_GP_WIN * ctf_fixed_maxseg(tp)))) {
17715 			/* Nope not enough data */
17716 			return;
17717 		}
17718 	}
17719 	tp->t_flags |= TF_GPUTINPROG;
17720 	rack->r_ctl.rc_gp_cumack_ts = 0;
17721 	rack->r_ctl.rc_gp_lowrtt = 0xffffffff;
17722 	rack->r_ctl.rc_gp_high_rwnd = rack->rc_tp->snd_wnd;
17723 	tp->gput_seq = startseq;
17724 	rack->app_limited_needs_set = 0;
17725 	if (rack->in_probe_rtt)
17726 		rack->measure_saw_probe_rtt = 1;
17727 	else if ((rack->measure_saw_probe_rtt) &&
17728 		 (SEQ_GEQ(tp->gput_seq, rack->r_ctl.rc_probertt_sndmax_atexit)))
17729 		rack->measure_saw_probe_rtt = 0;
17730 	if (rack->rc_gp_filled)
17731 		tp->gput_ts = rack->r_ctl.last_cumack_advance;
17732 	else {
17733 		/* Special case initial measurement */
17734 		struct timeval tv;
17735 
17736 		tp->gput_ts = tcp_get_usecs(&tv);
17737 		rack->r_ctl.rc_gp_output_ts = rack_to_usec_ts(&tv);
17738 	}
17739 	/*
17740 	 * We take a guess out into the future,
17741 	 * if we have no measurement and no
17742 	 * initial rate, we measure the first
17743 	 * initial-windows worth of data to
17744 	 * speed up getting some GP measurement and
17745 	 * thus start pacing.
17746 	 */
17747 	if ((rack->rc_gp_filled == 0) && (rack->r_ctl.init_rate == 0)) {
17748 		rack->app_limited_needs_set = 1;
17749 		tp->gput_ack = startseq + max(rc_init_window(rack),
17750 					      (MIN_GP_WIN * ctf_fixed_maxseg(tp)));
17751 		rack_log_pacing_delay_calc(rack,
17752 					   tp->gput_seq,
17753 					   tp->gput_ack,
17754 					   0,
17755 					   tp->gput_ts,
17756 					   (((uint64_t)rack->r_ctl.rc_app_limited_cnt << 32) | (uint64_t)rack->r_ctl.rc_gp_output_ts),
17757 					   9,
17758 					   __LINE__, NULL, 0);
17759 		rack_tend_gp_marks(tp, rack);
17760 		rack_log_gpset(rack, tp->gput_ack, 0, 0, __LINE__, 1, NULL);
17761 		return;
17762 	}
17763 	if (sb_offset) {
17764 		/*
17765 		 * We are out somewhere in the sb
17766 		 * can we use the already outstanding data?
17767 		 */
17768 
17769 		if (rack->r_ctl.rc_app_limited_cnt == 0) {
17770 			/*
17771 			 * Yes first one is good and in this case
17772 			 * the tp->gput_ts is correctly set based on
17773 			 * the last ack that arrived (no need to
17774 			 * set things up when an ack comes in).
17775 			 */
17776 			my_rsm = tqhash_min(rack->r_ctl.tqh);
17777 			if ((my_rsm == NULL) ||
17778 			    (my_rsm->r_rtr_cnt != 1)) {
17779 				/* retransmission? */
17780 				goto use_latest;
17781 			}
17782 		} else {
17783 			if (rack->r_ctl.rc_first_appl == NULL) {
17784 				/*
17785 				 * If rc_first_appl is NULL
17786 				 * then the cnt should be 0.
17787 				 * This is probably an error, maybe
17788 				 * a KASSERT would be approprate.
17789 				 */
17790 				goto use_latest;
17791 			}
17792 			/*
17793 			 * If we have a marker pointer to the last one that is
17794 			 * app limited we can use that, but we need to set
17795 			 * things up so that when it gets ack'ed we record
17796 			 * the ack time (if its not already acked).
17797 			 */
17798 			rack->app_limited_needs_set = 1;
17799 			/*
17800 			 * We want to get to the rsm that is either
17801 			 * next with space i.e. over 1 MSS or the one
17802 			 * after that (after the app-limited).
17803 			 */
17804 			my_rsm = tqhash_next(rack->r_ctl.tqh, rack->r_ctl.rc_first_appl);
17805 			if (my_rsm) {
17806 				if ((my_rsm->r_end - my_rsm->r_start) <= ctf_fixed_maxseg(tp))
17807 					/* Have to use the next one */
17808 					my_rsm = tqhash_next(rack->r_ctl.tqh, my_rsm);
17809 				else {
17810 					/* Use after the first MSS of it is acked */
17811 					tp->gput_seq = my_rsm->r_start + ctf_fixed_maxseg(tp);
17812 					goto start_set;
17813 				}
17814 			}
17815 			if ((my_rsm == NULL) ||
17816 			    (my_rsm->r_rtr_cnt != 1)) {
17817 				/*
17818 				 * Either its a retransmit or
17819 				 * the last is the app-limited one.
17820 				 */
17821 				goto use_latest;
17822 			}
17823 		}
17824 		tp->gput_seq = my_rsm->r_start;
17825 start_set:
17826 		if (my_rsm->r_flags & RACK_ACKED) {
17827 			/*
17828 			 * This one has been acked use the arrival ack time
17829 			 */
17830 			struct rack_sendmap *nrsm;
17831 
17832 			tp->gput_ts = (uint32_t)my_rsm->r_ack_arrival;
17833 			rack->app_limited_needs_set = 0;
17834 			/*
17835 			 * Ok in this path we need to use the r_end now
17836 			 * since this guy is the starting ack.
17837 			 */
17838 			tp->gput_seq = my_rsm->r_end;
17839 			/*
17840 			 * We also need to adjust up the sendtime
17841 			 * to the send of the next data after my_rsm.
17842 			 */
17843 			nrsm = tqhash_next(rack->r_ctl.tqh, my_rsm);
17844 			if (nrsm != NULL)
17845 				my_rsm = nrsm;
17846 			else {
17847 				/*
17848 				 * The next as not been sent, thats the
17849 				 * case for using the latest.
17850 				 */
17851 				goto use_latest;
17852 			}
17853 		}
17854 		rack->r_ctl.rc_gp_output_ts = my_rsm->r_tim_lastsent[0];
17855 		tp->gput_ack = tp->gput_seq + rack_get_measure_window(tp, rack);
17856 		rack->r_ctl.rc_gp_cumack_ts = 0;
17857 		if ((rack->r_ctl.cleared_app_ack == 1) &&
17858 		    (SEQ_GEQ(tp->gput_seq, rack->r_ctl.cleared_app_ack_seq))) {
17859 			/*
17860 			 * We just cleared an application limited period
17861 			 * so the next seq out needs to skip the first
17862 			 * ack.
17863 			 */
17864 			rack->app_limited_needs_set = 1;
17865 			rack->r_ctl.cleared_app_ack = 0;
17866 		}
17867 		rack_log_pacing_delay_calc(rack,
17868 					   tp->gput_seq,
17869 					   tp->gput_ack,
17870 					   (uintptr_t)my_rsm,
17871 					   tp->gput_ts,
17872 					   (((uint64_t)rack->r_ctl.rc_app_limited_cnt << 32) | (uint64_t)rack->r_ctl.rc_gp_output_ts),
17873 					   9,
17874 					   __LINE__, my_rsm, 0);
17875 		/* Now lets make sure all are marked as they should be */
17876 		rack_tend_gp_marks(tp, rack);
17877 		rack_log_gpset(rack, tp->gput_ack, 0, 0, __LINE__, 1, NULL);
17878 		return;
17879 	}
17880 
17881 use_latest:
17882 	/*
17883 	 * We don't know how long we may have been
17884 	 * idle or if this is the first-send. Lets
17885 	 * setup the flag so we will trim off
17886 	 * the first ack'd data so we get a true
17887 	 * measurement.
17888 	 */
17889 	rack->app_limited_needs_set = 1;
17890 	tp->gput_ack = startseq + rack_get_measure_window(tp, rack);
17891 	rack->r_ctl.rc_gp_cumack_ts = 0;
17892 	/* Find this guy so we can pull the send time */
17893 	my_rsm = tqhash_find(rack->r_ctl.tqh, startseq);
17894 	if (my_rsm) {
17895 		rack->r_ctl.rc_gp_output_ts = my_rsm->r_tim_lastsent[0];
17896 		if (my_rsm->r_flags & RACK_ACKED) {
17897 			/*
17898 			 * Unlikely since its probably what was
17899 			 * just transmitted (but I am paranoid).
17900 			 */
17901 			tp->gput_ts = (uint32_t)my_rsm->r_ack_arrival;
17902 			rack->app_limited_needs_set = 0;
17903 		}
17904 		if (SEQ_LT(my_rsm->r_start, tp->gput_seq)) {
17905 			/* This also is unlikely */
17906 			tp->gput_seq = my_rsm->r_start;
17907 		}
17908 	} else {
17909 		/*
17910 		 * TSNH unless we have some send-map limit,
17911 		 * and even at that it should not be hitting
17912 		 * that limit (we should have stopped sending).
17913 		 */
17914 		struct timeval tv;
17915 
17916 		microuptime(&tv);
17917 		rack->r_ctl.rc_gp_output_ts = rack_to_usec_ts(&tv);
17918 	}
17919 	rack_tend_gp_marks(tp, rack);
17920 	rack_log_pacing_delay_calc(rack,
17921 				   tp->gput_seq,
17922 				   tp->gput_ack,
17923 				   (uintptr_t)my_rsm,
17924 				   tp->gput_ts,
17925 				   (((uint64_t)rack->r_ctl.rc_app_limited_cnt << 32) | (uint64_t)rack->r_ctl.rc_gp_output_ts),
17926 				   9, __LINE__, NULL, 0);
17927 	rack_log_gpset(rack, tp->gput_ack, 0, 0, __LINE__, 1, NULL);
17928 }
17929 
17930 static inline uint32_t
17931 rack_what_can_we_send(struct tcpcb *tp, struct tcp_rack *rack,  uint32_t cwnd_to_use,
17932     uint32_t avail, int32_t sb_offset)
17933 {
17934 	uint32_t len;
17935 	uint32_t sendwin;
17936 
17937 	if (tp->snd_wnd > cwnd_to_use)
17938 		sendwin = cwnd_to_use;
17939 	else
17940 		sendwin = tp->snd_wnd;
17941 	if (ctf_outstanding(tp) >= tp->snd_wnd) {
17942 		/* We never want to go over our peers rcv-window */
17943 		len = 0;
17944 	} else {
17945 		uint32_t flight;
17946 
17947 		flight = ctf_flight_size(tp, rack->r_ctl.rc_sacked);
17948 		if (flight >= sendwin) {
17949 			/*
17950 			 * We have in flight what we are allowed by cwnd (if
17951 			 * it was rwnd blocking it would have hit above out
17952 			 * >= tp->snd_wnd).
17953 			 */
17954 			return (0);
17955 		}
17956 		len = sendwin - flight;
17957 		if ((len + ctf_outstanding(tp)) > tp->snd_wnd) {
17958 			/* We would send too much (beyond the rwnd) */
17959 			len = tp->snd_wnd - ctf_outstanding(tp);
17960 		}
17961 		if ((len + sb_offset) > avail) {
17962 			/*
17963 			 * We don't have that much in the SB, how much is
17964 			 * there?
17965 			 */
17966 			len = avail - sb_offset;
17967 		}
17968 	}
17969 	return (len);
17970 }
17971 
17972 static void
17973 rack_log_fsb(struct tcp_rack *rack, struct tcpcb *tp, struct socket *so, uint32_t flags,
17974 	     unsigned ipoptlen, int32_t orig_len, int32_t len, int error,
17975 	     int rsm_is_null, int optlen, int line, uint16_t mode)
17976 {
17977 	if (rack_verbose_logging && tcp_bblogging_on(rack->rc_tp)) {
17978 		union tcp_log_stackspecific log;
17979 		struct timeval tv;
17980 
17981 		memset(&log, 0, sizeof(log));
17982 		log.u_bbr.inhpts = tcp_in_hpts(rack->rc_tp);
17983 		log.u_bbr.flex1 = error;
17984 		log.u_bbr.flex2 = flags;
17985 		log.u_bbr.flex3 = rsm_is_null;
17986 		log.u_bbr.flex4 = ipoptlen;
17987 		log.u_bbr.flex5 = tp->rcv_numsacks;
17988 		log.u_bbr.flex6 = rack->r_ctl.rc_agg_early;
17989 		log.u_bbr.flex7 = optlen;
17990 		log.u_bbr.flex8 = rack->r_fsb_inited;
17991 		log.u_bbr.applimited = rack->r_fast_output;
17992 		log.u_bbr.bw_inuse = rack_get_bw(rack);
17993 		log.u_bbr.pacing_gain = rack_get_output_gain(rack, NULL);
17994 		log.u_bbr.cwnd_gain = mode;
17995 		log.u_bbr.pkts_out = orig_len;
17996 		log.u_bbr.lt_epoch = len;
17997 		log.u_bbr.delivered = line;
17998 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
17999 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
18000 		tcp_log_event(tp, NULL, &so->so_rcv, &so->so_snd, TCP_LOG_FSB, 0,
18001 			       len, &log, false, NULL, __func__, __LINE__, &tv);
18002 	}
18003 }
18004 
18005 
18006 static struct mbuf *
18007 rack_fo_base_copym(struct mbuf *the_m, uint32_t the_off, int32_t *plen,
18008 		   struct rack_fast_send_blk *fsb,
18009 		   int32_t seglimit, int32_t segsize, int hw_tls)
18010 {
18011 #ifdef KERN_TLS
18012 	struct ktls_session *tls, *ntls;
18013 #ifdef INVARIANTS
18014 	struct mbuf *start;
18015 #endif
18016 #endif
18017 	struct mbuf *m, *n, **np, *smb;
18018 	struct mbuf *top;
18019 	int32_t off, soff;
18020 	int32_t len = *plen;
18021 	int32_t fragsize;
18022 	int32_t len_cp = 0;
18023 	uint32_t mlen, frags;
18024 
18025 	soff = off = the_off;
18026 	smb = m = the_m;
18027 	np = &top;
18028 	top = NULL;
18029 #ifdef KERN_TLS
18030 	if (hw_tls && (m->m_flags & M_EXTPG))
18031 		tls = m->m_epg_tls;
18032 	else
18033 		tls = NULL;
18034 #ifdef INVARIANTS
18035 	start = m;
18036 #endif
18037 #endif
18038 	while (len > 0) {
18039 		if (m == NULL) {
18040 			*plen = len_cp;
18041 			break;
18042 		}
18043 #ifdef KERN_TLS
18044 		if (hw_tls) {
18045 			if (m->m_flags & M_EXTPG)
18046 				ntls = m->m_epg_tls;
18047 			else
18048 				ntls = NULL;
18049 
18050 			/*
18051 			 * Avoid mixing TLS records with handshake
18052 			 * data or TLS records from different
18053 			 * sessions.
18054 			 */
18055 			if (tls != ntls) {
18056 				MPASS(m != start);
18057 				*plen = len_cp;
18058 				break;
18059 			}
18060 		}
18061 #endif
18062 		mlen = min(len, m->m_len - off);
18063 		if (seglimit) {
18064 			/*
18065 			 * For M_EXTPG mbufs, add 3 segments
18066 			 * + 1 in case we are crossing page boundaries
18067 			 * + 2 in case the TLS hdr/trailer are used
18068 			 * It is cheaper to just add the segments
18069 			 * than it is to take the cache miss to look
18070 			 * at the mbuf ext_pgs state in detail.
18071 			 */
18072 			if (m->m_flags & M_EXTPG) {
18073 				fragsize = min(segsize, PAGE_SIZE);
18074 				frags = 3;
18075 			} else {
18076 				fragsize = segsize;
18077 				frags = 0;
18078 			}
18079 
18080 			/* Break if we really can't fit anymore. */
18081 			if ((frags + 1) >= seglimit) {
18082 				*plen =	len_cp;
18083 				break;
18084 			}
18085 
18086 			/*
18087 			 * Reduce size if you can't copy the whole
18088 			 * mbuf. If we can't copy the whole mbuf, also
18089 			 * adjust len so the loop will end after this
18090 			 * mbuf.
18091 			 */
18092 			if ((frags + howmany(mlen, fragsize)) >= seglimit) {
18093 				mlen = (seglimit - frags - 1) * fragsize;
18094 				len = mlen;
18095 				*plen = len_cp + len;
18096 			}
18097 			frags += howmany(mlen, fragsize);
18098 			if (frags == 0)
18099 				frags++;
18100 			seglimit -= frags;
18101 			KASSERT(seglimit > 0,
18102 			    ("%s: seglimit went too low", __func__));
18103 		}
18104 		n = m_get(M_NOWAIT, m->m_type);
18105 		*np = n;
18106 		if (n == NULL)
18107 			goto nospace;
18108 		n->m_len = mlen;
18109 		soff += mlen;
18110 		len_cp += n->m_len;
18111 		if (m->m_flags & (M_EXT | M_EXTPG)) {
18112 			n->m_data = m->m_data + off;
18113 			mb_dupcl(n, m);
18114 		} else {
18115 			bcopy(mtod(m, caddr_t)+off, mtod(n, caddr_t),
18116 			    (u_int)n->m_len);
18117 		}
18118 		len -= n->m_len;
18119 		off = 0;
18120 		m = m->m_next;
18121 		np = &n->m_next;
18122 		if (len || (soff == smb->m_len)) {
18123 			/*
18124 			 * We have more so we move forward  or
18125 			 * we have consumed the entire mbuf and
18126 			 * len has fell to 0.
18127 			 */
18128 			soff = 0;
18129 			smb = m;
18130 		}
18131 
18132 	}
18133 	if (fsb != NULL) {
18134 		fsb->m = smb;
18135 		fsb->off = soff;
18136 		if (smb) {
18137 			/*
18138 			 * Save off the size of the mbuf. We do
18139 			 * this so that we can recognize when it
18140 			 * has been trimmed by sbcut() as acks
18141 			 * come in.
18142 			 */
18143 			fsb->o_m_len = smb->m_len;
18144 			fsb->o_t_len = M_TRAILINGROOM(smb);
18145 		} else {
18146 			/*
18147 			 * This is the case where the next mbuf went to NULL. This
18148 			 * means with this copy we have sent everything in the sb.
18149 			 * In theory we could clear the fast_output flag, but lets
18150 			 * not since its possible that we could get more added
18151 			 * and acks that call the extend function which would let
18152 			 * us send more.
18153 			 */
18154 			fsb->o_m_len = 0;
18155 			fsb->o_t_len = 0;
18156 		}
18157 	}
18158 	return (top);
18159 nospace:
18160 	if (top)
18161 		m_freem(top);
18162 	return (NULL);
18163 
18164 }
18165 
18166 /*
18167  * This is a copy of m_copym(), taking the TSO segment size/limit
18168  * constraints into account, and advancing the sndptr as it goes.
18169  */
18170 static struct mbuf *
18171 rack_fo_m_copym(struct tcp_rack *rack, int32_t *plen,
18172 		int32_t seglimit, int32_t segsize, struct mbuf **s_mb, int *s_soff)
18173 {
18174 	struct mbuf *m, *n;
18175 	int32_t soff;
18176 
18177 	m = rack->r_ctl.fsb.m;
18178 	if (M_TRAILINGROOM(m) != rack->r_ctl.fsb.o_t_len) {
18179 		/*
18180 		 * The trailing space changed, mbufs can grow
18181 		 * at the tail but they can't shrink from
18182 		 * it, KASSERT that. Adjust the orig_m_len to
18183 		 * compensate for this change.
18184 		 */
18185 		KASSERT((rack->r_ctl.fsb.o_t_len > M_TRAILINGROOM(m)),
18186 			("mbuf:%p rack:%p trailing_space:%jd ots:%u oml:%u mlen:%u\n",
18187 			 m,
18188 			 rack,
18189 			 (intmax_t)M_TRAILINGROOM(m),
18190 			 rack->r_ctl.fsb.o_t_len,
18191 			 rack->r_ctl.fsb.o_m_len,
18192 			 m->m_len));
18193 		rack->r_ctl.fsb.o_m_len += (rack->r_ctl.fsb.o_t_len - M_TRAILINGROOM(m));
18194 		rack->r_ctl.fsb.o_t_len = M_TRAILINGROOM(m);
18195 	}
18196 	if (m->m_len < rack->r_ctl.fsb.o_m_len) {
18197 		/*
18198 		 * Mbuf shrank, trimmed off the top by an ack, our
18199 		 * offset changes.
18200 		 */
18201 		KASSERT((rack->r_ctl.fsb.off >= (rack->r_ctl.fsb.o_m_len - m->m_len)),
18202 			("mbuf:%p len:%u rack:%p oml:%u soff:%u\n",
18203 			 m, m->m_len,
18204 			 rack, rack->r_ctl.fsb.o_m_len,
18205 			 rack->r_ctl.fsb.off));
18206 
18207 		if (rack->r_ctl.fsb.off >= (rack->r_ctl.fsb.o_m_len- m->m_len))
18208 			rack->r_ctl.fsb.off -= (rack->r_ctl.fsb.o_m_len - m->m_len);
18209 		else
18210 			rack->r_ctl.fsb.off = 0;
18211 		rack->r_ctl.fsb.o_m_len = m->m_len;
18212 #ifdef INVARIANTS
18213 	} else if (m->m_len > rack->r_ctl.fsb.o_m_len) {
18214 		panic("rack:%p m:%p m_len grew outside of t_space compensation",
18215 		      rack, m);
18216 #endif
18217 	}
18218 	soff = rack->r_ctl.fsb.off;
18219 	KASSERT(soff >= 0, ("%s, negative off %d", __FUNCTION__, soff));
18220 	KASSERT(*plen >= 0, ("%s, negative len %d", __FUNCTION__, *plen));
18221 	KASSERT(soff < m->m_len, ("%s rack:%p len:%u m:%p m->m_len:%u < off?",
18222 				 __FUNCTION__,
18223 				 rack, *plen, m, m->m_len));
18224 	/* Save off the right location before we copy and advance */
18225 	*s_soff = soff;
18226 	*s_mb = rack->r_ctl.fsb.m;
18227 	n = rack_fo_base_copym(m, soff, plen,
18228 			       &rack->r_ctl.fsb,
18229 			       seglimit, segsize, rack->r_ctl.fsb.hw_tls);
18230 	return (n);
18231 }
18232 
18233 /* Log the buffer level */
18234 static void
18235 rack_log_queue_level(struct tcpcb *tp, struct tcp_rack *rack,
18236 		     int len, struct timeval *tv,
18237 		     uint32_t cts)
18238 {
18239 	uint32_t p_rate = 0, p_queue = 0, err = 0;
18240 	union tcp_log_stackspecific log;
18241 
18242 #ifdef RATELIMIT
18243 	err = in_pcbquery_txrlevel(rack->rc_inp, &p_queue);
18244 	err = in_pcbquery_txrtlmt(rack->rc_inp,	&p_rate);
18245 #endif
18246 	memset(&log, 0, sizeof(log));
18247 	log.u_bbr.inhpts = tcp_in_hpts(rack->rc_tp);
18248 	log.u_bbr.flex1 = p_rate;
18249 	log.u_bbr.flex2 = p_queue;
18250 	log.u_bbr.flex4 = (uint32_t)rack->r_ctl.crte->using;
18251 	log.u_bbr.flex5 = (uint32_t)rack->r_ctl.crte->rs_num_enobufs;
18252 	log.u_bbr.flex6 = rack->r_ctl.crte->time_between;
18253 	log.u_bbr.flex7 = 99;
18254 	log.u_bbr.flex8 = 0;
18255 	log.u_bbr.pkts_out = err;
18256 	log.u_bbr.delRate = rack->r_ctl.crte->rate;
18257 	log.u_bbr.timeStamp = cts;
18258 	log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
18259 	tcp_log_event(tp, NULL, NULL, NULL, BBR_LOG_HDWR_PACE, 0,
18260 		       len, &log, false, NULL, __func__, __LINE__, tv);
18261 
18262 }
18263 
18264 static uint32_t
18265 rack_check_queue_level(struct tcp_rack *rack, struct tcpcb *tp,
18266 		       struct timeval *tv, uint32_t cts, int len, uint32_t segsiz)
18267 {
18268 	uint64_t lentime = 0;
18269 #ifdef RATELIMIT
18270 	uint32_t p_rate = 0, p_queue = 0, err;
18271 	union tcp_log_stackspecific log;
18272 	uint64_t bw;
18273 
18274 	err = in_pcbquery_txrlevel(rack->rc_inp, &p_queue);
18275 	/* Failed or queue is zero */
18276 	if (err || (p_queue == 0)) {
18277 		lentime = 0;
18278 		goto out;
18279 	}
18280 	err = in_pcbquery_txrtlmt(rack->rc_inp, &p_rate);
18281 	if (err) {
18282 		lentime = 0;
18283 		goto out;
18284 	}
18285 	/*
18286 	 * If we reach here we have some bytes in
18287 	 * the queue. The number returned is a value
18288 	 * between 0 and 0xffff where ffff is full
18289 	 * and 0 is empty. So how best to make this into
18290 	 * something usable?
18291 	 *
18292 	 * The "safer" way is lets take the b/w gotten
18293 	 * from the query (which should be our b/w rate)
18294 	 * and pretend that a full send (our rc_pace_max_segs)
18295 	 * is outstanding. We factor it so its as if a full
18296 	 * number of our MSS segment is terms of full
18297 	 * ethernet segments are outstanding.
18298 	 */
18299 	bw = p_rate / 8;
18300 	if (bw) {
18301 		lentime = (rack->r_ctl.rc_pace_max_segs / segsiz);
18302 		lentime *= ETHERNET_SEGMENT_SIZE;
18303 		lentime *= (uint64_t)HPTS_USEC_IN_SEC;
18304 		lentime /= bw;
18305 	} else {
18306 		/* TSNH -- KASSERT? */
18307 		lentime = 0;
18308 	}
18309 out:
18310 	if (tcp_bblogging_on(tp)) {
18311 		memset(&log, 0, sizeof(log));
18312 		log.u_bbr.inhpts = tcp_in_hpts(rack->rc_tp);
18313 		log.u_bbr.flex1 = p_rate;
18314 		log.u_bbr.flex2 = p_queue;
18315 		log.u_bbr.flex4 = (uint32_t)rack->r_ctl.crte->using;
18316 		log.u_bbr.flex5 = (uint32_t)rack->r_ctl.crte->rs_num_enobufs;
18317 		log.u_bbr.flex6 = rack->r_ctl.crte->time_between;
18318 		log.u_bbr.flex7 = 99;
18319 		log.u_bbr.flex8 = 0;
18320 		log.u_bbr.pkts_out = err;
18321 		log.u_bbr.delRate = rack->r_ctl.crte->rate;
18322 		log.u_bbr.cur_del_rate = lentime;
18323 		log.u_bbr.timeStamp = cts;
18324 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
18325 		tcp_log_event(tp, NULL, NULL, NULL, BBR_LOG_HDWR_PACE, 0,
18326 			       len, &log, false, NULL, __func__, __LINE__,tv);
18327 	}
18328 #endif
18329 	return ((uint32_t)lentime);
18330 }
18331 
18332 static int
18333 rack_fast_rsm_output(struct tcpcb *tp, struct tcp_rack *rack, struct rack_sendmap *rsm,
18334 		     uint64_t ts_val, uint32_t cts, uint32_t ms_cts, struct timeval *tv, int len, uint8_t doing_tlp)
18335 {
18336 	/*
18337 	 * Enter the fast retransmit path. We are given that a sched_pin is
18338 	 * in place (if accounting is compliled in) and the cycle count taken
18339 	 * at the entry is in the ts_val. The concept her is that the rsm
18340 	 * now holds the mbuf offsets and such so we can directly transmit
18341 	 * without a lot of overhead, the len field is already set for
18342 	 * us to prohibit us from sending too much (usually its 1MSS).
18343 	 */
18344 	struct ip *ip = NULL;
18345 	struct udphdr *udp = NULL;
18346 	struct tcphdr *th = NULL;
18347 	struct mbuf *m = NULL;
18348 	struct inpcb *inp;
18349 	uint8_t *cpto;
18350 	struct tcp_log_buffer *lgb;
18351 #ifdef TCP_ACCOUNTING
18352 	uint64_t crtsc;
18353 	int cnt_thru = 1;
18354 #endif
18355 	struct tcpopt to;
18356 	u_char opt[TCP_MAXOLEN];
18357 	uint32_t hdrlen, optlen;
18358 	int32_t pacing_delay, segsiz, max_val, tso = 0, error = 0, ulen = 0;
18359 	uint16_t flags;
18360 	uint32_t if_hw_tsomaxsegcount = 0, startseq;
18361 	uint32_t if_hw_tsomaxsegsize;
18362 	int32_t ip_sendflag = IP_NO_SND_TAG_RL;
18363 
18364 #ifdef INET6
18365 	struct ip6_hdr *ip6 = NULL;
18366 
18367 	if (rack->r_is_v6) {
18368 		ip6 = (struct ip6_hdr *)rack->r_ctl.fsb.tcp_ip_hdr;
18369 		hdrlen = sizeof(struct ip6_hdr) + sizeof(struct tcphdr);
18370 	} else
18371 #endif				/* INET6 */
18372 	{
18373 		ip = (struct ip *)rack->r_ctl.fsb.tcp_ip_hdr;
18374 		hdrlen = sizeof(struct tcpiphdr);
18375 	}
18376 	if (tp->t_port && (V_tcp_udp_tunneling_port == 0)) {
18377 		goto failed;
18378 	}
18379 	if (doing_tlp) {
18380 		/* Its a TLP add the flag, it may already be there but be sure */
18381 		rsm->r_flags |= RACK_TLP;
18382 	} else {
18383 		/* If it was a TLP it is not not on this retransmit */
18384 		rsm->r_flags &= ~RACK_TLP;
18385 	}
18386 	startseq = rsm->r_start;
18387 	segsiz = min(ctf_fixed_maxseg(tp), rack->r_ctl.rc_pace_min_segs);
18388 	inp = rack->rc_inp;
18389 	to.to_flags = 0;
18390 	flags = tcp_outflags[tp->t_state];
18391 	if (flags & (TH_SYN|TH_RST)) {
18392 		goto failed;
18393 	}
18394 	if (rsm->r_flags & RACK_HAS_FIN) {
18395 		/* We can't send a FIN here */
18396 		goto failed;
18397 	}
18398 	if (flags & TH_FIN) {
18399 		/* We never send a FIN */
18400 		flags &= ~TH_FIN;
18401 	}
18402 	if (tp->t_flags & TF_RCVD_TSTMP) {
18403 		to.to_tsval = ms_cts + tp->ts_offset;
18404 		to.to_tsecr = tp->ts_recent;
18405 		to.to_flags = TOF_TS;
18406 	}
18407 #if defined(IPSEC_SUPPORT) || defined(TCP_SIGNATURE)
18408 	/* TCP-MD5 (RFC2385). */
18409 	if (tp->t_flags & TF_SIGNATURE)
18410 		to.to_flags |= TOF_SIGNATURE;
18411 #endif
18412 	optlen = tcp_addoptions(&to, opt);
18413 	hdrlen += optlen;
18414 	udp = rack->r_ctl.fsb.udp;
18415 	if (udp)
18416 		hdrlen += sizeof(struct udphdr);
18417 	if (rack->r_ctl.rc_pace_max_segs)
18418 		max_val = rack->r_ctl.rc_pace_max_segs;
18419 	else if (rack->rc_user_set_max_segs)
18420 		max_val = rack->rc_user_set_max_segs * segsiz;
18421 	else
18422 		max_val = len;
18423 	if ((tp->t_flags & TF_TSO) &&
18424 	    V_tcp_do_tso &&
18425 	    (len > segsiz) &&
18426 	    (tp->t_port == 0))
18427 		tso = 1;
18428 #ifdef INET6
18429 	if (MHLEN < hdrlen + max_linkhdr)
18430 		m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR);
18431 	else
18432 #endif
18433 		m = m_gethdr(M_NOWAIT, MT_DATA);
18434 	if (m == NULL)
18435 		goto failed;
18436 	m->m_data += max_linkhdr;
18437 	m->m_len = hdrlen;
18438 	th = rack->r_ctl.fsb.th;
18439 	/* Establish the len to send */
18440 	if (len > max_val)
18441 		len = max_val;
18442 	if ((tso) && (len + optlen > segsiz)) {
18443 		uint32_t if_hw_tsomax;
18444 		int32_t max_len;
18445 
18446 		/* extract TSO information */
18447 		if_hw_tsomax = tp->t_tsomax;
18448 		if_hw_tsomaxsegcount = tp->t_tsomaxsegcount;
18449 		if_hw_tsomaxsegsize = tp->t_tsomaxsegsize;
18450 		/*
18451 		 * Check if we should limit by maximum payload
18452 		 * length:
18453 		 */
18454 		if (if_hw_tsomax != 0) {
18455 			/* compute maximum TSO length */
18456 			max_len = (if_hw_tsomax - hdrlen -
18457 				   max_linkhdr);
18458 			if (max_len <= 0) {
18459 				goto failed;
18460 			} else if (len > max_len) {
18461 				len = max_len;
18462 			}
18463 		}
18464 		if (len <= segsiz) {
18465 			/*
18466 			 * In case there are too many small fragments don't
18467 			 * use TSO:
18468 			 */
18469 			tso = 0;
18470 		}
18471 	} else {
18472 		tso = 0;
18473 	}
18474 	if ((tso == 0) && (len > segsiz))
18475 		len = segsiz;
18476 	(void)tcp_get_usecs(tv);
18477 	if ((len == 0) ||
18478 	    (len <= MHLEN - hdrlen - max_linkhdr)) {
18479 		goto failed;
18480 	}
18481 	th->th_seq = htonl(rsm->r_start);
18482 	th->th_ack = htonl(tp->rcv_nxt);
18483 	/*
18484 	 * The PUSH bit should only be applied
18485 	 * if the full retransmission is made. If
18486 	 * we are sending less than this is the
18487 	 * left hand edge and should not have
18488 	 * the PUSH bit.
18489 	 */
18490 	if ((rsm->r_flags & RACK_HAD_PUSH) &&
18491 	    (len == (rsm->r_end - rsm->r_start)))
18492 		flags |= TH_PUSH;
18493 	th->th_win = htons((u_short)(rack->r_ctl.fsb.recwin >> tp->rcv_scale));
18494 	if (th->th_win == 0) {
18495 		tp->t_sndzerowin++;
18496 		tp->t_flags |= TF_RXWIN0SENT;
18497 	} else
18498 		tp->t_flags &= ~TF_RXWIN0SENT;
18499 	if (rsm->r_flags & RACK_TLP) {
18500 		/*
18501 		 * TLP should not count in retran count, but
18502 		 * in its own bin
18503 		 */
18504 		counter_u64_add(rack_tlp_retran, 1);
18505 		counter_u64_add(rack_tlp_retran_bytes, len);
18506 	} else {
18507 		tp->t_sndrexmitpack++;
18508 		KMOD_TCPSTAT_INC(tcps_sndrexmitpack);
18509 		KMOD_TCPSTAT_ADD(tcps_sndrexmitbyte, len);
18510 	}
18511 #ifdef STATS
18512 	stats_voi_update_abs_u32(tp->t_stats, VOI_TCP_RETXPB,
18513 				 len);
18514 #endif
18515 	if (rsm->m == NULL)
18516 		goto failed;
18517 	if (rsm->m &&
18518 	    ((rsm->orig_m_len != rsm->m->m_len) ||
18519 	     (M_TRAILINGROOM(rsm->m) != rsm->orig_t_space))) {
18520 		/* Fix up the orig_m_len and possibly the mbuf offset */
18521 		rack_adjust_orig_mlen(rsm);
18522 	}
18523 	m->m_next = rack_fo_base_copym(rsm->m, rsm->soff, &len, NULL, if_hw_tsomaxsegcount, if_hw_tsomaxsegsize, rsm->r_hw_tls);
18524 	if (len <= segsiz) {
18525 		/*
18526 		 * Must have ran out of mbufs for the copy
18527 		 * shorten it to no longer need tso. Lets
18528 		 * not put on sendalot since we are low on
18529 		 * mbufs.
18530 		 */
18531 		tso = 0;
18532 	}
18533 	if ((m->m_next == NULL) || (len <= 0)){
18534 		goto failed;
18535 	}
18536 	if (udp) {
18537 		if (rack->r_is_v6)
18538 			ulen = hdrlen + len - sizeof(struct ip6_hdr);
18539 		else
18540 			ulen = hdrlen + len - sizeof(struct ip);
18541 		udp->uh_ulen = htons(ulen);
18542 	}
18543 	m->m_pkthdr.rcvif = (struct ifnet *)0;
18544 	if (TCPS_HAVERCVDSYN(tp->t_state) &&
18545 	    (tp->t_flags2 & (TF2_ECN_PERMIT | TF2_ACE_PERMIT))) {
18546 		int ect = tcp_ecn_output_established(tp, &flags, len, true);
18547 		if ((tp->t_state == TCPS_SYN_RECEIVED) &&
18548 		    (tp->t_flags2 & TF2_ECN_SND_ECE))
18549 		    tp->t_flags2 &= ~TF2_ECN_SND_ECE;
18550 #ifdef INET6
18551 		if (rack->r_is_v6) {
18552 		    ip6->ip6_flow &= ~htonl(IPTOS_ECN_MASK << 20);
18553 		    ip6->ip6_flow |= htonl(ect << 20);
18554 		}
18555 		else
18556 #endif
18557 		{
18558 		    ip->ip_tos &= ~IPTOS_ECN_MASK;
18559 		    ip->ip_tos |= ect;
18560 		}
18561 	}
18562 	if (rack->r_ctl.crte != NULL) {
18563 		/* See if we can send via the hw queue */
18564 		pacing_delay = rack_check_queue_level(rack, tp, tv, cts, len, segsiz);
18565 		/* If there is nothing in queue (no pacing time) we can send via the hw queue */
18566 		if (pacing_delay == 0)
18567 			ip_sendflag = 0;
18568 	}
18569 	tcp_set_flags(th, flags);
18570 	m->m_pkthdr.len = hdrlen + len;	/* in6_cksum() need this */
18571 #if defined(IPSEC_SUPPORT) || defined(TCP_SIGNATURE)
18572 	if (to.to_flags & TOF_SIGNATURE) {
18573 		/*
18574 		 * Calculate MD5 signature and put it into the place
18575 		 * determined before.
18576 		 * NOTE: since TCP options buffer doesn't point into
18577 		 * mbuf's data, calculate offset and use it.
18578 		 */
18579 		if (!TCPMD5_ENABLED() || TCPMD5_OUTPUT(m, th,
18580 						       (u_char *)(th + 1) + (to.to_signature - opt)) != 0) {
18581 			/*
18582 			 * Do not send segment if the calculation of MD5
18583 			 * digest has failed.
18584 			 */
18585 			goto failed;
18586 		}
18587 	}
18588 #endif
18589 #ifdef INET6
18590 	if (rack->r_is_v6) {
18591 		if (tp->t_port) {
18592 			m->m_pkthdr.csum_flags = CSUM_UDP_IPV6;
18593 			m->m_pkthdr.csum_data = offsetof(struct udphdr, uh_sum);
18594 			udp->uh_sum = in6_cksum_pseudo(ip6, ulen, IPPROTO_UDP, 0);
18595 			th->th_sum = htons(0);
18596 			UDPSTAT_INC(udps_opackets);
18597 		} else {
18598 			m->m_pkthdr.csum_flags = CSUM_TCP_IPV6;
18599 			m->m_pkthdr.csum_data = offsetof(struct tcphdr, th_sum);
18600 			th->th_sum = in6_cksum_pseudo(ip6,
18601 						      sizeof(struct tcphdr) + optlen + len, IPPROTO_TCP,
18602 						      0);
18603 		}
18604 	}
18605 #endif
18606 #if defined(INET6) && defined(INET)
18607 	else
18608 #endif
18609 #ifdef INET
18610 	{
18611 		if (tp->t_port) {
18612 			m->m_pkthdr.csum_flags = CSUM_UDP;
18613 			m->m_pkthdr.csum_data = offsetof(struct udphdr, uh_sum);
18614 			udp->uh_sum = in_pseudo(ip->ip_src.s_addr,
18615 						ip->ip_dst.s_addr, htons(ulen + IPPROTO_UDP));
18616 			th->th_sum = htons(0);
18617 			UDPSTAT_INC(udps_opackets);
18618 		} else {
18619 			m->m_pkthdr.csum_flags = CSUM_TCP;
18620 			m->m_pkthdr.csum_data = offsetof(struct tcphdr, th_sum);
18621 			th->th_sum = in_pseudo(ip->ip_src.s_addr,
18622 					       ip->ip_dst.s_addr, htons(sizeof(struct tcphdr) +
18623 									IPPROTO_TCP + len + optlen));
18624 		}
18625 		/* IP version must be set here for ipv4/ipv6 checking later */
18626 		KASSERT(ip->ip_v == IPVERSION,
18627 			("%s: IP version incorrect: %d", __func__, ip->ip_v));
18628 	}
18629 #endif
18630 	if (tso) {
18631 		/*
18632 		 * Here we use segsiz since we have no added options besides
18633 		 * any standard timestamp options (no DSACKs or SACKS are sent
18634 		 * via either fast-path).
18635 		 */
18636 		KASSERT(len > segsiz,
18637 			("%s: len <= tso_segsz tp:%p", __func__, tp));
18638 		m->m_pkthdr.csum_flags |= CSUM_TSO;
18639 		m->m_pkthdr.tso_segsz = segsiz;
18640 	}
18641 #ifdef INET6
18642 	if (rack->r_is_v6) {
18643 		ip6->ip6_hlim = rack->r_ctl.fsb.hoplimit;
18644 		ip6->ip6_plen = htons(m->m_pkthdr.len - sizeof(*ip6));
18645 		if (V_path_mtu_discovery && tp->t_maxseg > V_tcp_minmss)
18646 			tp->t_flags2 |= TF2_PLPMTU_PMTUD;
18647 		else
18648 			tp->t_flags2 &= ~TF2_PLPMTU_PMTUD;
18649 	}
18650 #endif
18651 #if defined(INET) && defined(INET6)
18652 	else
18653 #endif
18654 #ifdef INET
18655 	{
18656 		ip->ip_len = htons(m->m_pkthdr.len);
18657 		ip->ip_ttl = rack->r_ctl.fsb.hoplimit;
18658 		if (V_path_mtu_discovery && tp->t_maxseg > V_tcp_minmss) {
18659 			tp->t_flags2 |= TF2_PLPMTU_PMTUD;
18660 			if (tp->t_port == 0 || len < V_tcp_minmss) {
18661 				ip->ip_off |= htons(IP_DF);
18662 			}
18663 		} else {
18664 			tp->t_flags2 &= ~TF2_PLPMTU_PMTUD;
18665 		}
18666 	}
18667 #endif
18668 	if (doing_tlp == 0) {
18669 		/* Set we retransmitted */
18670 		rack->rc_gp_saw_rec = 1;
18671 	} else {
18672 		/* Its a TLP set ca or ss */
18673 		if (tp->snd_cwnd > tp->snd_ssthresh) {
18674 			/* Set we sent in CA */
18675 			rack->rc_gp_saw_ca = 1;
18676 		} else {
18677 			/* Set we sent in SS */
18678 			rack->rc_gp_saw_ss = 1;
18679 		}
18680 	}
18681 	/* Time to copy in our header */
18682 	cpto = mtod(m, uint8_t *);
18683 	memcpy(cpto, rack->r_ctl.fsb.tcp_ip_hdr, rack->r_ctl.fsb.tcp_ip_hdr_len);
18684 	th = (struct tcphdr *)(cpto + ((uint8_t *)rack->r_ctl.fsb.th - rack->r_ctl.fsb.tcp_ip_hdr));
18685 	if (optlen) {
18686 		bcopy(opt, th + 1, optlen);
18687 		th->th_off = (sizeof(struct tcphdr) + optlen) >> 2;
18688 	} else {
18689 		th->th_off = sizeof(struct tcphdr) >> 2;
18690 	}
18691 	if (tcp_bblogging_on(rack->rc_tp)) {
18692 		union tcp_log_stackspecific log;
18693 
18694 		if (rsm->r_flags & RACK_RWND_COLLAPSED) {
18695 			rack_log_collapse(rack, rsm->r_start, rsm->r_end, 0, __LINE__, 5, rsm->r_flags, rsm);
18696 			counter_u64_add(rack_collapsed_win_rxt, 1);
18697 			counter_u64_add(rack_collapsed_win_rxt_bytes, (rsm->r_end - rsm->r_start));
18698 		}
18699 		memset(&log, 0, sizeof(log));
18700 		log.u_bbr.inhpts = tcp_in_hpts(rack->rc_tp);
18701 		if (rack->rack_no_prr)
18702 			log.u_bbr.flex1 = 0;
18703 		else
18704 			log.u_bbr.flex1 = rack->r_ctl.rc_prr_sndcnt;
18705 		log.u_bbr.flex2 = rack->r_ctl.rc_pace_min_segs;
18706 		log.u_bbr.flex3 = rack->r_ctl.rc_pace_max_segs;
18707 		log.u_bbr.flex4 = max_val;
18708 		/* Save off the early/late values */
18709 		log.u_bbr.flex6 = rack->r_ctl.rc_agg_early;
18710 		log.u_bbr.applimited = rack->r_ctl.rc_agg_delayed;
18711 		log.u_bbr.bw_inuse = rack_get_bw(rack);
18712 		log.u_bbr.cur_del_rate = rack->r_ctl.gp_bw;
18713 		if (doing_tlp == 0)
18714 			log.u_bbr.flex8 = 1;
18715 		else
18716 			log.u_bbr.flex8 = 2;
18717 		log.u_bbr.pacing_gain = rack_get_output_gain(rack, NULL);
18718 		log.u_bbr.flex7 = 55;
18719 		log.u_bbr.pkts_out = tp->t_maxseg;
18720 		log.u_bbr.timeStamp = cts;
18721 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
18722 		if (rsm->r_rtr_cnt > 0) {
18723 			/*
18724 			 * When we have a retransmit we want to log the
18725 			 * burst at send and flight at send from before.
18726 			 */
18727 			log.u_bbr.flex5 = rsm->r_fas;
18728 			log.u_bbr.bbr_substate = rsm->r_bas;
18729 		} else {
18730 			/*
18731 			 * This is currently unlikely until we do the
18732 			 * packet pair probes but I will add it for completeness.
18733 			 */
18734 			log.u_bbr.flex5 = log.u_bbr.inflight;
18735 			log.u_bbr.bbr_substate = (uint8_t)((len + segsiz - 1)/segsiz);
18736 		}
18737 		log.u_bbr.lt_epoch = rack->r_ctl.cwnd_to_use;
18738 		log.u_bbr.delivered = 0;
18739 		log.u_bbr.rttProp = (uintptr_t)rsm;
18740 		log.u_bbr.delRate = rsm->r_flags;
18741 		log.u_bbr.delRate <<= 31;
18742 		log.u_bbr.delRate |= rack->r_must_retran;
18743 		log.u_bbr.delRate <<= 1;
18744 		log.u_bbr.delRate |= 1;
18745 		log.u_bbr.pkt_epoch = __LINE__;
18746 		lgb = tcp_log_event(tp, th, NULL, NULL, TCP_LOG_OUT, ERRNO_UNK,
18747 				     len, &log, false, NULL, __func__, __LINE__, tv);
18748 	} else
18749 		lgb = NULL;
18750 	if ((rack->r_ctl.crte != NULL) &&
18751 	    tcp_bblogging_on(tp)) {
18752 		rack_log_queue_level(tp, rack, len, tv, cts);
18753 	}
18754 #ifdef INET6
18755 	if (rack->r_is_v6) {
18756 		error = ip6_output(m, inp->in6p_outputopts,
18757 				   &inp->inp_route6,
18758 				   ip_sendflag, NULL, NULL, inp);
18759 	}
18760 	else
18761 #endif
18762 #ifdef INET
18763 	{
18764 		error = ip_output(m, NULL,
18765 				  &inp->inp_route,
18766 				  ip_sendflag, 0, inp);
18767 	}
18768 #endif
18769 	m = NULL;
18770 	if (lgb) {
18771 		lgb->tlb_errno = error;
18772 		lgb = NULL;
18773 	}
18774 	/* Move snd_nxt to snd_max so we don't have false retransmissions */
18775 	tp->snd_nxt = tp->snd_max;
18776 	if (error) {
18777 		goto failed;
18778 	} else if (rack->rc_hw_nobuf && (ip_sendflag != IP_NO_SND_TAG_RL)) {
18779 		rack->rc_hw_nobuf = 0;
18780 		rack->r_ctl.rc_agg_delayed = 0;
18781 		rack->r_early = 0;
18782 		rack->r_late = 0;
18783 		rack->r_ctl.rc_agg_early = 0;
18784 	}
18785 	rack_log_output(tp, &to, len, rsm->r_start, flags, error, rack_to_usec_ts(tv),
18786 			rsm, RACK_SENT_FP, rsm->m, rsm->soff, rsm->r_hw_tls, segsiz);
18787 	if (doing_tlp) {
18788 		rack->rc_tlp_in_progress = 1;
18789 		rack->r_ctl.rc_tlp_cnt_out++;
18790 	}
18791 	if (error == 0) {
18792 		counter_u64_add(rack_total_bytes, len);
18793 		tcp_account_for_send(tp, len, 1, doing_tlp, rsm->r_hw_tls);
18794 		if (doing_tlp) {
18795 			rack->rc_last_sent_tlp_past_cumack = 0;
18796 			rack->rc_last_sent_tlp_seq_valid = 1;
18797 			rack->r_ctl.last_sent_tlp_seq = rsm->r_start;
18798 			rack->r_ctl.last_sent_tlp_len = rsm->r_end - rsm->r_start;
18799 		}
18800 		if (rack->r_ctl.rc_prr_sndcnt >= len)
18801 			rack->r_ctl.rc_prr_sndcnt -= len;
18802 		else
18803 			rack->r_ctl.rc_prr_sndcnt = 0;
18804 	}
18805 	tp->t_flags &= ~(TF_ACKNOW | TF_DELACK);
18806 	rack->forced_ack = 0;	/* If we send something zap the FA flag */
18807 	if (IN_FASTRECOVERY(tp->t_flags) && rsm)
18808 		rack->r_ctl.retran_during_recovery += len;
18809 	{
18810 		int idx;
18811 
18812 		idx = (len / segsiz) + 3;
18813 		if (idx >= TCP_MSS_ACCT_ATIMER)
18814 			counter_u64_add(rack_out_size[(TCP_MSS_ACCT_ATIMER-1)], 1);
18815 		else
18816 			counter_u64_add(rack_out_size[idx], 1);
18817 	}
18818 	if (tp->t_rtttime == 0) {
18819 		tp->t_rtttime = ticks;
18820 		tp->t_rtseq = startseq;
18821 		KMOD_TCPSTAT_INC(tcps_segstimed);
18822 	}
18823 	counter_u64_add(rack_fto_rsm_send, 1);
18824 	if (error && (error == ENOBUFS)) {
18825 		if (rack->r_ctl.crte != NULL) {
18826 			tcp_trace_point(rack->rc_tp, TCP_TP_HWENOBUF);
18827 			if (tcp_bblogging_on(rack->rc_tp))
18828 				rack_log_queue_level(tp, rack, len, tv, cts);
18829 		} else
18830 			tcp_trace_point(rack->rc_tp, TCP_TP_ENOBUF);
18831 		pacing_delay = ((1 + rack->rc_enobuf) * HPTS_USEC_IN_MSEC);
18832 		if (rack->rc_enobuf < 0x7f)
18833 			rack->rc_enobuf++;
18834 		if (pacing_delay < (10 * HPTS_USEC_IN_MSEC))
18835 			pacing_delay = 10 * HPTS_USEC_IN_MSEC;
18836 		if (rack->r_ctl.crte != NULL) {
18837 			counter_u64_add(rack_saw_enobuf_hw, 1);
18838 			tcp_rl_log_enobuf(rack->r_ctl.crte);
18839 		}
18840 		counter_u64_add(rack_saw_enobuf, 1);
18841 	} else {
18842 		pacing_delay = rack_get_pacing_delay(rack, tp, len, NULL, segsiz, __LINE__);
18843 	}
18844 	rack_start_hpts_timer(rack, tp, cts, pacing_delay, len, 0);
18845 #ifdef TCP_ACCOUNTING
18846 	crtsc = get_cyclecount();
18847 	if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
18848 		tp->tcp_cnt_counters[SND_OUT_DATA] += cnt_thru;
18849 		tp->tcp_proc_time[SND_OUT_DATA] += (crtsc - ts_val);
18850 		tp->tcp_cnt_counters[CNT_OF_MSS_OUT] += ((len + segsiz - 1) / segsiz);
18851 	}
18852 	sched_unpin();
18853 #endif
18854 	return (0);
18855 failed:
18856 	if (m)
18857 		m_free(m);
18858 	return (-1);
18859 }
18860 
18861 static void
18862 rack_sndbuf_autoscale(struct tcp_rack *rack)
18863 {
18864 	/*
18865 	 * Automatic sizing of send socket buffer.  Often the send buffer
18866 	 * size is not optimally adjusted to the actual network conditions
18867 	 * at hand (delay bandwidth product).  Setting the buffer size too
18868 	 * small limits throughput on links with high bandwidth and high
18869 	 * delay (eg. trans-continental/oceanic links).  Setting the
18870 	 * buffer size too big consumes too much real kernel memory,
18871 	 * especially with many connections on busy servers.
18872 	 *
18873 	 * The criteria to step up the send buffer one notch are:
18874 	 *  1. receive window of remote host is larger than send buffer
18875 	 *     (with a fudge factor of 5/4th);
18876 	 *  2. send buffer is filled to 7/8th with data (so we actually
18877 	 *     have data to make use of it);
18878 	 *  3. send buffer fill has not hit maximal automatic size;
18879 	 *  4. our send window (slow start and cogestion controlled) is
18880 	 *     larger than sent but unacknowledged data in send buffer.
18881 	 *
18882 	 * Note that the rack version moves things much faster since
18883 	 * we want to avoid hitting cache lines in the rack_fast_output()
18884 	 * path so this is called much less often and thus moves
18885 	 * the SB forward by a percentage.
18886 	 */
18887 	struct socket *so;
18888 	struct tcpcb *tp;
18889 	uint32_t sendwin, scaleup;
18890 
18891 	tp = rack->rc_tp;
18892 	so = rack->rc_inp->inp_socket;
18893 	sendwin = min(rack->r_ctl.cwnd_to_use, tp->snd_wnd);
18894 	if (V_tcp_do_autosndbuf && so->so_snd.sb_flags & SB_AUTOSIZE) {
18895 		if ((tp->snd_wnd / 4 * 5) >= so->so_snd.sb_hiwat &&
18896 		    sbused(&so->so_snd) >=
18897 		    (so->so_snd.sb_hiwat / 8 * 7) &&
18898 		    sbused(&so->so_snd) < V_tcp_autosndbuf_max &&
18899 		    sendwin >= (sbused(&so->so_snd) -
18900 		    (tp->snd_max - tp->snd_una))) {
18901 			if (rack_autosndbuf_inc)
18902 				scaleup = (rack_autosndbuf_inc * so->so_snd.sb_hiwat) / 100;
18903 			else
18904 				scaleup = V_tcp_autosndbuf_inc;
18905 			if (scaleup < V_tcp_autosndbuf_inc)
18906 				scaleup = V_tcp_autosndbuf_inc;
18907 			scaleup += so->so_snd.sb_hiwat;
18908 			if (scaleup > V_tcp_autosndbuf_max)
18909 				scaleup = V_tcp_autosndbuf_max;
18910 			if (!sbreserve_locked(so, SO_SND, scaleup, curthread))
18911 				so->so_snd.sb_flags &= ~SB_AUTOSIZE;
18912 		}
18913 	}
18914 }
18915 
18916 static int
18917 rack_fast_output(struct tcpcb *tp, struct tcp_rack *rack, uint64_t ts_val,
18918 		 uint32_t cts, uint32_t ms_cts, struct timeval *tv, long *tot_len, int *send_err, int line)
18919 {
18920 	/*
18921 	 * Enter to do fast output. We are given that the sched_pin is
18922 	 * in place (if accounting is compiled in) and the cycle count taken
18923 	 * at entry is in place in ts_val. The idea here is that
18924 	 * we know how many more bytes needs to be sent (presumably either
18925 	 * during pacing or to fill the cwnd and that was greater than
18926 	 * the max-burst). We have how much to send and all the info we
18927 	 * need to just send.
18928 	 */
18929 #ifdef INET
18930 	struct ip *ip = NULL;
18931 #endif
18932 	struct udphdr *udp = NULL;
18933 	struct tcphdr *th = NULL;
18934 	struct mbuf *m, *s_mb;
18935 	struct inpcb *inp;
18936 	uint8_t *cpto;
18937 	struct tcp_log_buffer *lgb;
18938 #ifdef TCP_ACCOUNTING
18939 	uint64_t crtsc;
18940 #endif
18941 	struct tcpopt to;
18942 	u_char opt[TCP_MAXOLEN];
18943 	uint32_t hdrlen, optlen;
18944 #ifdef TCP_ACCOUNTING
18945 	int cnt_thru = 1;
18946 #endif
18947 	int32_t pacing_delay, segsiz, len, max_val, tso = 0, sb_offset, error, ulen = 0;
18948 	uint16_t flags;
18949 	uint32_t s_soff;
18950 	uint32_t if_hw_tsomaxsegcount = 0, startseq;
18951 	uint32_t if_hw_tsomaxsegsize;
18952 	uint32_t add_flag = RACK_SENT_FP;
18953 #ifdef INET6
18954 	struct ip6_hdr *ip6 = NULL;
18955 
18956 	if (rack->r_is_v6) {
18957 		ip6 = (struct ip6_hdr *)rack->r_ctl.fsb.tcp_ip_hdr;
18958 		hdrlen = sizeof(struct ip6_hdr) + sizeof(struct tcphdr);
18959 	} else
18960 #endif				/* INET6 */
18961 	{
18962 #ifdef INET
18963 		ip = (struct ip *)rack->r_ctl.fsb.tcp_ip_hdr;
18964 		hdrlen = sizeof(struct tcpiphdr);
18965 #endif
18966 	}
18967 	if (tp->t_port && (V_tcp_udp_tunneling_port == 0)) {
18968 		m = NULL;
18969 		goto failed;
18970 	}
18971 	rack->r_ctl.cwnd_to_use = tp->snd_cwnd;
18972 	startseq = tp->snd_max;
18973 	segsiz = min(ctf_fixed_maxseg(tp), rack->r_ctl.rc_pace_min_segs);
18974 	inp = rack->rc_inp;
18975 	len = rack->r_ctl.fsb.left_to_send;
18976 	to.to_flags = 0;
18977 	flags = rack->r_ctl.fsb.tcp_flags;
18978 	if (tp->t_flags & TF_RCVD_TSTMP) {
18979 		to.to_tsval = ms_cts + tp->ts_offset;
18980 		to.to_tsecr = tp->ts_recent;
18981 		to.to_flags = TOF_TS;
18982 	}
18983 #if defined(IPSEC_SUPPORT) || defined(TCP_SIGNATURE)
18984 	/* TCP-MD5 (RFC2385). */
18985 	if (tp->t_flags & TF_SIGNATURE)
18986 		to.to_flags |= TOF_SIGNATURE;
18987 #endif
18988 	optlen = tcp_addoptions(&to, opt);
18989 	hdrlen += optlen;
18990 	udp = rack->r_ctl.fsb.udp;
18991 	if (udp)
18992 		hdrlen += sizeof(struct udphdr);
18993 	if (rack->r_ctl.rc_pace_max_segs)
18994 		max_val = rack->r_ctl.rc_pace_max_segs;
18995 	else if (rack->rc_user_set_max_segs)
18996 		max_val = rack->rc_user_set_max_segs * segsiz;
18997 	else
18998 		max_val = len;
18999 	if ((tp->t_flags & TF_TSO) &&
19000 	    V_tcp_do_tso &&
19001 	    (len > segsiz) &&
19002 	    (tp->t_port == 0))
19003 		tso = 1;
19004 again:
19005 #ifdef INET6
19006 	if (MHLEN < hdrlen + max_linkhdr)
19007 		m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR);
19008 	else
19009 #endif
19010 		m = m_gethdr(M_NOWAIT, MT_DATA);
19011 	if (m == NULL)
19012 		goto failed;
19013 	m->m_data += max_linkhdr;
19014 	m->m_len = hdrlen;
19015 	th = rack->r_ctl.fsb.th;
19016 	/* Establish the len to send */
19017 	if (len > max_val)
19018 		len = max_val;
19019 	if ((tso) && (len + optlen > segsiz)) {
19020 		uint32_t if_hw_tsomax;
19021 		int32_t max_len;
19022 
19023 		/* extract TSO information */
19024 		if_hw_tsomax = tp->t_tsomax;
19025 		if_hw_tsomaxsegcount = tp->t_tsomaxsegcount;
19026 		if_hw_tsomaxsegsize = tp->t_tsomaxsegsize;
19027 		/*
19028 		 * Check if we should limit by maximum payload
19029 		 * length:
19030 		 */
19031 		if (if_hw_tsomax != 0) {
19032 			/* compute maximum TSO length */
19033 			max_len = (if_hw_tsomax - hdrlen -
19034 				   max_linkhdr);
19035 			if (max_len <= 0) {
19036 				goto failed;
19037 			} else if (len > max_len) {
19038 				len = max_len;
19039 			}
19040 		}
19041 		if (len <= segsiz) {
19042 			/*
19043 			 * In case there are too many small fragments don't
19044 			 * use TSO:
19045 			 */
19046 			tso = 0;
19047 		}
19048 	} else {
19049 		tso = 0;
19050 	}
19051 	if ((tso == 0) && (len > segsiz))
19052 		len = segsiz;
19053 	(void)tcp_get_usecs(tv);
19054 	if ((len == 0) ||
19055 	    (len <= MHLEN - hdrlen - max_linkhdr)) {
19056 		goto failed;
19057 	}
19058 	sb_offset = tp->snd_max - tp->snd_una;
19059 	th->th_seq = htonl(tp->snd_max);
19060 	th->th_ack = htonl(tp->rcv_nxt);
19061 	th->th_win = htons((u_short)(rack->r_ctl.fsb.recwin >> tp->rcv_scale));
19062 	if (th->th_win == 0) {
19063 		tp->t_sndzerowin++;
19064 		tp->t_flags |= TF_RXWIN0SENT;
19065 	} else
19066 		tp->t_flags &= ~TF_RXWIN0SENT;
19067 	tp->snd_up = tp->snd_una;	/* drag it along, its deprecated */
19068 	KMOD_TCPSTAT_INC(tcps_sndpack);
19069 	KMOD_TCPSTAT_ADD(tcps_sndbyte, len);
19070 #ifdef STATS
19071 	stats_voi_update_abs_u64(tp->t_stats, VOI_TCP_TXPB,
19072 				 len);
19073 #endif
19074 	if (rack->r_ctl.fsb.m == NULL)
19075 		goto failed;
19076 
19077 	/* s_mb and s_soff are saved for rack_log_output */
19078 	m->m_next = rack_fo_m_copym(rack, &len, if_hw_tsomaxsegcount, if_hw_tsomaxsegsize,
19079 				    &s_mb, &s_soff);
19080 	if (len <= segsiz) {
19081 		/*
19082 		 * Must have ran out of mbufs for the copy
19083 		 * shorten it to no longer need tso. Lets
19084 		 * not put on sendalot since we are low on
19085 		 * mbufs.
19086 		 */
19087 		tso = 0;
19088 	}
19089 	if (rack->r_ctl.fsb.rfo_apply_push &&
19090 	    (len == rack->r_ctl.fsb.left_to_send)) {
19091 		flags |= TH_PUSH;
19092 		add_flag |= RACK_HAD_PUSH;
19093 	}
19094 	if ((m->m_next == NULL) || (len <= 0)){
19095 		goto failed;
19096 	}
19097 	if (udp) {
19098 		if (rack->r_is_v6)
19099 			ulen = hdrlen + len - sizeof(struct ip6_hdr);
19100 		else
19101 			ulen = hdrlen + len - sizeof(struct ip);
19102 		udp->uh_ulen = htons(ulen);
19103 	}
19104 	m->m_pkthdr.rcvif = (struct ifnet *)0;
19105 	if (TCPS_HAVERCVDSYN(tp->t_state) &&
19106 	    (tp->t_flags2 & (TF2_ECN_PERMIT | TF2_ACE_PERMIT))) {
19107 		int ect = tcp_ecn_output_established(tp, &flags, len, false);
19108 		if ((tp->t_state == TCPS_SYN_RECEIVED) &&
19109 		    (tp->t_flags2 & TF2_ECN_SND_ECE))
19110 			tp->t_flags2 &= ~TF2_ECN_SND_ECE;
19111 #ifdef INET6
19112 		if (rack->r_is_v6) {
19113 			ip6->ip6_flow &= ~htonl(IPTOS_ECN_MASK << 20);
19114 			ip6->ip6_flow |= htonl(ect << 20);
19115 		}
19116 		else
19117 #endif
19118 		{
19119 #ifdef INET
19120 			ip->ip_tos &= ~IPTOS_ECN_MASK;
19121 			ip->ip_tos |= ect;
19122 #endif
19123 		}
19124 	}
19125 	tcp_set_flags(th, flags);
19126 	m->m_pkthdr.len = hdrlen + len;	/* in6_cksum() need this */
19127 #if defined(IPSEC_SUPPORT) || defined(TCP_SIGNATURE)
19128 	if (to.to_flags & TOF_SIGNATURE) {
19129 		/*
19130 		 * Calculate MD5 signature and put it into the place
19131 		 * determined before.
19132 		 * NOTE: since TCP options buffer doesn't point into
19133 		 * mbuf's data, calculate offset and use it.
19134 		 */
19135 		if (!TCPMD5_ENABLED() || TCPMD5_OUTPUT(m, th,
19136 						       (u_char *)(th + 1) + (to.to_signature - opt)) != 0) {
19137 			/*
19138 			 * Do not send segment if the calculation of MD5
19139 			 * digest has failed.
19140 			 */
19141 			goto failed;
19142 		}
19143 	}
19144 #endif
19145 #ifdef INET6
19146 	if (rack->r_is_v6) {
19147 		if (tp->t_port) {
19148 			m->m_pkthdr.csum_flags = CSUM_UDP_IPV6;
19149 			m->m_pkthdr.csum_data = offsetof(struct udphdr, uh_sum);
19150 			udp->uh_sum = in6_cksum_pseudo(ip6, ulen, IPPROTO_UDP, 0);
19151 			th->th_sum = htons(0);
19152 			UDPSTAT_INC(udps_opackets);
19153 		} else {
19154 			m->m_pkthdr.csum_flags = CSUM_TCP_IPV6;
19155 			m->m_pkthdr.csum_data = offsetof(struct tcphdr, th_sum);
19156 			th->th_sum = in6_cksum_pseudo(ip6,
19157 						      sizeof(struct tcphdr) + optlen + len, IPPROTO_TCP,
19158 						      0);
19159 		}
19160 	}
19161 #endif
19162 #if defined(INET6) && defined(INET)
19163 	else
19164 #endif
19165 #ifdef INET
19166 	{
19167 		if (tp->t_port) {
19168 			m->m_pkthdr.csum_flags = CSUM_UDP;
19169 			m->m_pkthdr.csum_data = offsetof(struct udphdr, uh_sum);
19170 			udp->uh_sum = in_pseudo(ip->ip_src.s_addr,
19171 						ip->ip_dst.s_addr, htons(ulen + IPPROTO_UDP));
19172 			th->th_sum = htons(0);
19173 			UDPSTAT_INC(udps_opackets);
19174 		} else {
19175 			m->m_pkthdr.csum_flags = CSUM_TCP;
19176 			m->m_pkthdr.csum_data = offsetof(struct tcphdr, th_sum);
19177 			th->th_sum = in_pseudo(ip->ip_src.s_addr,
19178 					       ip->ip_dst.s_addr, htons(sizeof(struct tcphdr) +
19179 									IPPROTO_TCP + len + optlen));
19180 		}
19181 		/* IP version must be set here for ipv4/ipv6 checking later */
19182 		KASSERT(ip->ip_v == IPVERSION,
19183 			("%s: IP version incorrect: %d", __func__, ip->ip_v));
19184 	}
19185 #endif
19186 	if (tso) {
19187 		/*
19188 		 * Here we use segsiz since we have no added options besides
19189 		 * any standard timestamp options (no DSACKs or SACKS are sent
19190 		 * via either fast-path).
19191 		 */
19192 		KASSERT(len > segsiz,
19193 			("%s: len <= tso_segsz tp:%p", __func__, tp));
19194 		m->m_pkthdr.csum_flags |= CSUM_TSO;
19195 		m->m_pkthdr.tso_segsz = segsiz;
19196 	}
19197 #ifdef INET6
19198 	if (rack->r_is_v6) {
19199 		ip6->ip6_hlim = rack->r_ctl.fsb.hoplimit;
19200 		ip6->ip6_plen = htons(m->m_pkthdr.len - sizeof(*ip6));
19201 		if (V_path_mtu_discovery && tp->t_maxseg > V_tcp_minmss)
19202 			tp->t_flags2 |= TF2_PLPMTU_PMTUD;
19203 		else
19204 			tp->t_flags2 &= ~TF2_PLPMTU_PMTUD;
19205 	}
19206 #endif
19207 #if defined(INET) && defined(INET6)
19208 	else
19209 #endif
19210 #ifdef INET
19211 	{
19212 		ip->ip_len = htons(m->m_pkthdr.len);
19213 		ip->ip_ttl = rack->r_ctl.fsb.hoplimit;
19214 		if (V_path_mtu_discovery && tp->t_maxseg > V_tcp_minmss) {
19215 			tp->t_flags2 |= TF2_PLPMTU_PMTUD;
19216 			if (tp->t_port == 0 || len < V_tcp_minmss) {
19217 				ip->ip_off |= htons(IP_DF);
19218 			}
19219 		} else {
19220 			tp->t_flags2 &= ~TF2_PLPMTU_PMTUD;
19221 		}
19222 	}
19223 #endif
19224 	if (tp->snd_cwnd > tp->snd_ssthresh) {
19225 		/* Set we sent in CA */
19226 		rack->rc_gp_saw_ca = 1;
19227 	} else {
19228 		/* Set we sent in SS */
19229 		rack->rc_gp_saw_ss = 1;
19230 	}
19231 	/* Time to copy in our header */
19232 	cpto = mtod(m, uint8_t *);
19233 	memcpy(cpto, rack->r_ctl.fsb.tcp_ip_hdr, rack->r_ctl.fsb.tcp_ip_hdr_len);
19234 	th = (struct tcphdr *)(cpto + ((uint8_t *)rack->r_ctl.fsb.th - rack->r_ctl.fsb.tcp_ip_hdr));
19235 	if (optlen) {
19236 		bcopy(opt, th + 1, optlen);
19237 		th->th_off = (sizeof(struct tcphdr) + optlen) >> 2;
19238 	} else {
19239 		th->th_off = sizeof(struct tcphdr) >> 2;
19240 	}
19241 	if ((rack->r_ctl.crte != NULL) &&
19242 	    tcp_bblogging_on(tp)) {
19243 		rack_log_queue_level(tp, rack, len, tv, cts);
19244 	}
19245 	if (tcp_bblogging_on(rack->rc_tp)) {
19246 		union tcp_log_stackspecific log;
19247 
19248 		memset(&log, 0, sizeof(log));
19249 		log.u_bbr.inhpts = tcp_in_hpts(rack->rc_tp);
19250 		if (rack->rack_no_prr)
19251 			log.u_bbr.flex1 = 0;
19252 		else
19253 			log.u_bbr.flex1 = rack->r_ctl.rc_prr_sndcnt;
19254 		log.u_bbr.flex2 = rack->r_ctl.rc_pace_min_segs;
19255 		log.u_bbr.flex3 = rack->r_ctl.rc_pace_max_segs;
19256 		log.u_bbr.flex4 = max_val;
19257 		/* Save off the early/late values */
19258 		log.u_bbr.flex6 = rack->r_ctl.rc_agg_early;
19259 		log.u_bbr.applimited = rack->r_ctl.rc_agg_delayed;
19260 		log.u_bbr.bw_inuse = rack_get_bw(rack);
19261 		log.u_bbr.cur_del_rate = rack->r_ctl.gp_bw;
19262 		log.u_bbr.flex8 = 0;
19263 		log.u_bbr.pacing_gain = rack_get_output_gain(rack, NULL);
19264 		log.u_bbr.flex7 = 44;
19265 		log.u_bbr.pkts_out = tp->t_maxseg;
19266 		log.u_bbr.timeStamp = cts;
19267 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
19268 		log.u_bbr.flex5 = log.u_bbr.inflight;
19269 		log.u_bbr.lt_epoch = rack->r_ctl.cwnd_to_use;
19270 		log.u_bbr.delivered = rack->r_ctl.fsb.left_to_send;
19271 		log.u_bbr.rttProp = 0;
19272 		log.u_bbr.delRate = rack->r_must_retran;
19273 		log.u_bbr.delRate <<= 1;
19274 		log.u_bbr.pkt_epoch = line;
19275 		/* For fast output no retrans so just inflight and how many mss we send */
19276 		log.u_bbr.flex5 = log.u_bbr.inflight;
19277 		log.u_bbr.bbr_substate = (uint8_t)((len + segsiz - 1)/segsiz);
19278 		lgb = tcp_log_event(tp, th, NULL, NULL, TCP_LOG_OUT, ERRNO_UNK,
19279 				     len, &log, false, NULL, __func__, __LINE__, tv);
19280 	} else
19281 		lgb = NULL;
19282 #ifdef INET6
19283 	if (rack->r_is_v6) {
19284 		error = ip6_output(m, inp->in6p_outputopts,
19285 				   &inp->inp_route6,
19286 				   0, NULL, NULL, inp);
19287 	}
19288 #endif
19289 #if defined(INET) && defined(INET6)
19290 	else
19291 #endif
19292 #ifdef INET
19293 	{
19294 		error = ip_output(m, NULL,
19295 				  &inp->inp_route,
19296 				  0, 0, inp);
19297 	}
19298 #endif
19299 	if (lgb) {
19300 		lgb->tlb_errno = error;
19301 		lgb = NULL;
19302 	}
19303 	if (error) {
19304 		*send_err = error;
19305 		m = NULL;
19306 		goto failed;
19307 	} else if (rack->rc_hw_nobuf) {
19308 		rack->rc_hw_nobuf = 0;
19309 		rack->r_ctl.rc_agg_delayed = 0;
19310 		rack->r_early = 0;
19311 		rack->r_late = 0;
19312 		rack->r_ctl.rc_agg_early = 0;
19313 	}
19314 	if ((error == 0) && (rack->lt_bw_up == 0)) {
19315 		/* Unlikely */
19316 		rack->r_ctl.lt_timemark = tcp_tv_to_lusec(tv);
19317 		rack->r_ctl.lt_seq = tp->snd_una;
19318 		rack->lt_bw_up = 1;
19319 	} else if ((error == 0) &&
19320 		   (((tp->snd_max + len) - rack->r_ctl.lt_seq) > 0x7fffffff)) {
19321 		/*
19322 		 * Need to record what we have since we are
19323 		 * approaching seq wrap.
19324 		 */
19325 		struct timeval tv;
19326 		uint64_t tmark;
19327 
19328 		rack->r_ctl.lt_bw_bytes += (tp->snd_una - rack->r_ctl.lt_seq);
19329 		rack->r_ctl.lt_seq = tp->snd_una;
19330 		tmark = tcp_get_u64_usecs(&tv);
19331 		if (tmark > rack->r_ctl.lt_timemark) {
19332 			rack->r_ctl.lt_bw_time += (tmark - rack->r_ctl.lt_timemark);
19333 			rack->r_ctl.lt_timemark = tmark;
19334 		}
19335 	}
19336 	rack_log_output(tp, &to, len, tp->snd_max, flags, error, rack_to_usec_ts(tv),
19337 			NULL, add_flag, s_mb, s_soff, rack->r_ctl.fsb.hw_tls, segsiz);
19338 	if (tp->snd_una == tp->snd_max) {
19339 		rack->r_ctl.rc_tlp_rxt_last_time = cts;
19340 		rack_log_progress_event(rack, tp, ticks, PROGRESS_START, __LINE__);
19341 		tp->t_acktime = ticks;
19342 	}
19343 	counter_u64_add(rack_total_bytes, len);
19344 	tcp_account_for_send(tp, len, 0, 0, rack->r_ctl.fsb.hw_tls);
19345 
19346 	rack->forced_ack = 0;	/* If we send something zap the FA flag */
19347 	*tot_len += len;
19348 	if ((tp->t_flags & TF_GPUTINPROG) == 0)
19349 		rack_start_gp_measurement(tp, rack, tp->snd_max, sb_offset);
19350 	tp->snd_max += len;
19351 	tp->snd_nxt = tp->snd_max;
19352 	if (rack->rc_new_rnd_needed) {
19353 		rack_new_round_starts(tp, rack, tp->snd_max);
19354 	}
19355 	{
19356 		int idx;
19357 
19358 		idx = (len / segsiz) + 3;
19359 		if (idx >= TCP_MSS_ACCT_ATIMER)
19360 			counter_u64_add(rack_out_size[(TCP_MSS_ACCT_ATIMER-1)], 1);
19361 		else
19362 			counter_u64_add(rack_out_size[idx], 1);
19363 	}
19364 	if (len <= rack->r_ctl.fsb.left_to_send)
19365 		rack->r_ctl.fsb.left_to_send -= len;
19366 	else
19367 		rack->r_ctl.fsb.left_to_send = 0;
19368 	if (rack->r_ctl.fsb.left_to_send < segsiz) {
19369 		rack->r_fast_output = 0;
19370 		rack->r_ctl.fsb.left_to_send = 0;
19371 		/* At the end of fast_output scale up the sb */
19372 		SOCK_SENDBUF_LOCK(rack->rc_inp->inp_socket);
19373 		rack_sndbuf_autoscale(rack);
19374 		SOCK_SENDBUF_UNLOCK(rack->rc_inp->inp_socket);
19375 	}
19376 	if (tp->t_rtttime == 0) {
19377 		tp->t_rtttime = ticks;
19378 		tp->t_rtseq = startseq;
19379 		KMOD_TCPSTAT_INC(tcps_segstimed);
19380 	}
19381 	if ((rack->r_ctl.fsb.left_to_send >= segsiz) &&
19382 	    (max_val > len) &&
19383 	    (*tot_len < rack->r_ctl.rc_pace_max_segs) &&
19384 	    (tso == 0)) {
19385 		max_val -= len;
19386 		len = segsiz;
19387 		th = rack->r_ctl.fsb.th;
19388 #ifdef TCP_ACCOUNTING
19389 		cnt_thru++;
19390 #endif
19391 		goto again;
19392 	}
19393 	tp->t_flags &= ~(TF_ACKNOW | TF_DELACK);
19394 	counter_u64_add(rack_fto_send, 1);
19395 	pacing_delay = rack_get_pacing_delay(rack, tp, *tot_len, NULL, segsiz, __LINE__);
19396 	rack_start_hpts_timer(rack, tp, cts, pacing_delay, *tot_len, 0);
19397 #ifdef TCP_ACCOUNTING
19398 	crtsc = get_cyclecount();
19399 	if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
19400 		tp->tcp_cnt_counters[SND_OUT_DATA] += cnt_thru;
19401 		tp->tcp_proc_time[SND_OUT_DATA] += (crtsc - ts_val);
19402 		tp->tcp_cnt_counters[CNT_OF_MSS_OUT] += ((*tot_len + segsiz - 1) / segsiz);
19403 	}
19404 	sched_unpin();
19405 #endif
19406 	return (0);
19407 failed:
19408 	if (m)
19409 		m_free(m);
19410 	rack->r_fast_output = 0;
19411 	return (-1);
19412 }
19413 
19414 static inline void
19415 rack_setup_fast_output(struct tcpcb *tp, struct tcp_rack *rack,
19416 		       struct sockbuf *sb,
19417 		       int len, int orig_len, int segsiz, uint32_t pace_max_seg,
19418 		       bool hw_tls,
19419 		       uint16_t flags)
19420 {
19421 	rack->r_fast_output = 1;
19422 	rack->r_ctl.fsb.m = sbsndmbuf(sb, (tp->snd_max - tp->snd_una), &rack->r_ctl.fsb.off);
19423 	rack->r_ctl.fsb.o_m_len = rack->r_ctl.fsb.m->m_len;
19424 	rack->r_ctl.fsb.o_t_len = M_TRAILINGROOM(rack->r_ctl.fsb.m);
19425 	rack->r_ctl.fsb.tcp_flags = flags;
19426 	rack->r_ctl.fsb.left_to_send = orig_len - len;
19427 	if (rack->r_ctl.fsb.left_to_send < pace_max_seg) {
19428 		/* Less than a full sized pace, lets not  */
19429 		rack->r_fast_output = 0;
19430 		return;
19431 	} else {
19432 		/* Round down to the nearest pace_max_seg */
19433 		rack->r_ctl.fsb.left_to_send = rounddown(rack->r_ctl.fsb.left_to_send, pace_max_seg);
19434 	}
19435 	if (hw_tls)
19436 		rack->r_ctl.fsb.hw_tls = 1;
19437 	else
19438 		rack->r_ctl.fsb.hw_tls = 0;
19439 	KASSERT((rack->r_ctl.fsb.left_to_send <= (sbavail(sb) - (tp->snd_max - tp->snd_una))),
19440 		("rack:%p left_to_send:%u sbavail:%u out:%u",
19441 		 rack, rack->r_ctl.fsb.left_to_send, sbavail(sb),
19442 		 (tp->snd_max - tp->snd_una)));
19443 	if (rack->r_ctl.fsb.left_to_send < segsiz)
19444 		rack->r_fast_output = 0;
19445 	else {
19446 		if (rack->r_ctl.fsb.left_to_send == (sbavail(sb) - (tp->snd_max - tp->snd_una)))
19447 			rack->r_ctl.fsb.rfo_apply_push = 1;
19448 		else
19449 			rack->r_ctl.fsb.rfo_apply_push = 0;
19450 	}
19451 }
19452 
19453 static uint32_t
19454 rack_get_hpts_pacing_min_for_bw(struct tcp_rack *rack, int32_t segsiz)
19455 {
19456 	uint64_t min_time;
19457 	uint32_t maxlen;
19458 
19459 	min_time = (uint64_t)get_hpts_min_sleep_time();
19460 	maxlen = (uint32_t)((rack->r_ctl.gp_bw * min_time) / (uint64_t)HPTS_USEC_IN_SEC);
19461 	maxlen = roundup(maxlen, segsiz);
19462 	return (maxlen);
19463 }
19464 
19465 static struct rack_sendmap *
19466 rack_check_collapsed(struct tcp_rack *rack, uint32_t cts)
19467 {
19468 	struct rack_sendmap *rsm = NULL;
19469 	int thresh;
19470 
19471 restart:
19472 	rsm = tqhash_find(rack->r_ctl.tqh, rack->r_ctl.last_collapse_point);
19473 	if ((rsm == NULL) || ((rsm->r_flags & RACK_RWND_COLLAPSED) == 0)) {
19474 		/* Nothing, strange turn off validity  */
19475 		rack->r_collapse_point_valid = 0;
19476 		return (NULL);
19477 	}
19478 	/* Can we send it yet? */
19479 	if (rsm->r_end > (rack->rc_tp->snd_una + rack->rc_tp->snd_wnd)) {
19480 		/*
19481 		 * Receiver window has not grown enough for
19482 		 * the segment to be put on the wire.
19483 		 */
19484 		return (NULL);
19485 	}
19486 	if (rsm->r_flags & RACK_ACKED) {
19487 		/*
19488 		 * It has been sacked, lets move to the
19489 		 * next one if possible.
19490 		 */
19491 		rack->r_ctl.last_collapse_point = rsm->r_end;
19492 		/* Are we done? */
19493 		if (SEQ_GEQ(rack->r_ctl.last_collapse_point,
19494 			    rack->r_ctl.high_collapse_point)) {
19495 			rack->r_collapse_point_valid = 0;
19496 			return (NULL);
19497 		}
19498 		goto restart;
19499 	}
19500 	/* Now has it been long enough ? */
19501 	thresh = rack_calc_thresh_rack(rack, rack_grab_rtt(rack->rc_tp, rack), cts, __LINE__, 1);
19502 	if ((cts - ((uint32_t)rsm->r_tim_lastsent[(rsm->r_rtr_cnt-1)])) > thresh) {
19503 		rack_log_collapse(rack, rsm->r_start,
19504 				  (cts - ((uint32_t)rsm->r_tim_lastsent[(rsm->r_rtr_cnt-1)])),
19505 				  thresh, __LINE__, 6, rsm->r_flags, rsm);
19506 		return (rsm);
19507 	}
19508 	/* Not enough time */
19509 	rack_log_collapse(rack, rsm->r_start,
19510 			  (cts - ((uint32_t)rsm->r_tim_lastsent[(rsm->r_rtr_cnt-1)])),
19511 			  thresh, __LINE__, 7, rsm->r_flags, rsm);
19512 	return (NULL);
19513 }
19514 
19515 static inline void
19516 rack_validate_sizes(struct tcp_rack *rack, int32_t *len, int32_t segsiz, uint32_t pace_max_seg)
19517 {
19518 	if ((rack->full_size_rxt == 0) &&
19519 	    (rack->shape_rxt_to_pacing_min == 0) &&
19520 	    (*len >= segsiz)) {
19521 		*len = segsiz;
19522 	} else if (rack->shape_rxt_to_pacing_min &&
19523 		 rack->gp_ready) {
19524 		/* We use pacing min as shaping len req */
19525 		uint32_t maxlen;
19526 
19527 		maxlen = rack_get_hpts_pacing_min_for_bw(rack, segsiz);
19528 		if (*len > maxlen)
19529 			*len = maxlen;
19530 	} else {
19531 		/*
19532 		 * The else is full_size_rxt is on so send it all
19533 		 * note we do need to check this for exceeding
19534 		 * our max segment size due to the fact that
19535 		 * we do sometimes merge chunks together i.e.
19536 		 * we cannot just assume that we will never have
19537 		 * a chunk greater than pace_max_seg
19538 		 */
19539 		if (*len > pace_max_seg)
19540 			*len = pace_max_seg;
19541 	}
19542 }
19543 
19544 static int
19545 rack_output(struct tcpcb *tp)
19546 {
19547 	struct socket *so;
19548 	uint32_t recwin;
19549 	uint32_t sb_offset, s_moff = 0;
19550 	int32_t len, error = 0;
19551 	uint16_t flags;
19552 	struct mbuf *m, *s_mb = NULL;
19553 	struct mbuf *mb;
19554 	uint32_t if_hw_tsomaxsegcount = 0;
19555 	uint32_t if_hw_tsomaxsegsize;
19556 	int32_t segsiz, minseg;
19557 	long tot_len_this_send = 0;
19558 #ifdef INET
19559 	struct ip *ip = NULL;
19560 #endif
19561 	struct udphdr *udp = NULL;
19562 	struct tcp_rack *rack;
19563 	struct tcphdr *th;
19564 	uint8_t pass = 0;
19565 	uint8_t mark = 0;
19566 	uint8_t check_done = 0;
19567 	uint8_t wanted_cookie = 0;
19568 	u_char opt[TCP_MAXOLEN];
19569 	unsigned ipoptlen, optlen, hdrlen, ulen=0;
19570 	uint32_t rack_seq;
19571 
19572 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
19573 	unsigned ipsec_optlen = 0;
19574 
19575 #endif
19576 	int32_t idle, sendalot;
19577 	uint32_t tot_idle;
19578 	int32_t sub_from_prr = 0;
19579 	volatile int32_t sack_rxmit;
19580 	struct rack_sendmap *rsm = NULL;
19581 	int32_t tso, mtu;
19582 	struct tcpopt to;
19583 	int32_t pacing_delay = 0;
19584 	int32_t sup_rack = 0;
19585 	uint32_t cts, ms_cts, delayed, early;
19586 	uint32_t add_flag = RACK_SENT_SP;
19587 	/* The doing_tlp flag will be set by the actual rack_timeout_tlp() */
19588 	uint8_t doing_tlp = 0;
19589 	uint32_t cwnd_to_use, pace_max_seg;
19590 	int32_t do_a_prefetch = 0;
19591 	int32_t prefetch_rsm = 0;
19592 	int32_t orig_len = 0;
19593 	struct timeval tv;
19594 	int32_t prefetch_so_done = 0;
19595 	struct tcp_log_buffer *lgb;
19596 	struct inpcb *inp = tptoinpcb(tp);
19597 	struct sockbuf *sb;
19598 	uint64_t ts_val = 0;
19599 #ifdef TCP_ACCOUNTING
19600 	uint64_t crtsc;
19601 #endif
19602 #ifdef INET6
19603 	struct ip6_hdr *ip6 = NULL;
19604 	int32_t isipv6;
19605 #endif
19606 	bool hpts_calling, hw_tls = false;
19607 
19608 	NET_EPOCH_ASSERT();
19609 	INP_WLOCK_ASSERT(inp);
19610 
19611 	/* setup and take the cache hits here */
19612 	rack = (struct tcp_rack *)tp->t_fb_ptr;
19613 #ifdef TCP_ACCOUNTING
19614 	sched_pin();
19615 	ts_val = get_cyclecount();
19616 #endif
19617 	hpts_calling = !!(tp->t_flags2 & TF2_HPTS_CALLS);
19618 	tp->t_flags2 &= ~TF2_HPTS_CALLS;
19619 #ifdef TCP_OFFLOAD
19620 	if (tp->t_flags & TF_TOE) {
19621 #ifdef TCP_ACCOUNTING
19622 		sched_unpin();
19623 #endif
19624 		return (tcp_offload_output(tp));
19625 	}
19626 #endif
19627 	if (rack->rack_deferred_inited == 0) {
19628 		/*
19629 		 * If we are the connecting socket we will
19630 		 * hit rack_init() when no sequence numbers
19631 		 * are setup. This makes it so we must defer
19632 		 * some initialization. Call that now.
19633 		 */
19634 		rack_deferred_init(tp, rack);
19635 	}
19636 	/*
19637 	 * For TFO connections in SYN_RECEIVED, only allow the initial
19638 	 * SYN|ACK and those sent by the retransmit timer.
19639 	 */
19640 	if ((tp->t_flags & TF_FASTOPEN) &&
19641 	    (tp->t_state == TCPS_SYN_RECEIVED) &&
19642 	    SEQ_GT(tp->snd_max, tp->snd_una) &&    /* initial SYN|ACK sent */
19643 	    (rack->r_ctl.rc_resend == NULL)) {         /* not a retransmit */
19644 #ifdef TCP_ACCOUNTING
19645 		sched_unpin();
19646 #endif
19647 		return (0);
19648 	}
19649 #ifdef INET6
19650 	if (rack->r_state) {
19651 		/* Use the cache line loaded if possible */
19652 		isipv6 = rack->r_is_v6;
19653 	} else {
19654 		isipv6 = (rack->rc_inp->inp_vflag & INP_IPV6) != 0;
19655 	}
19656 #endif
19657 	early = 0;
19658 	cts = tcp_get_usecs(&tv);
19659 	ms_cts = tcp_tv_to_msec(&tv);
19660 	if (((rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT) == 0) &&
19661 	    tcp_in_hpts(rack->rc_tp)) {
19662 		/*
19663 		 * We are on the hpts for some timer but not hptsi output.
19664 		 * Remove from the hpts unconditionally.
19665 		 */
19666 		rack_timer_cancel(tp, rack, cts, __LINE__);
19667 	}
19668 	/* Are we pacing and late? */
19669 	if ((rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT) &&
19670 	    TSTMP_GEQ(cts, rack->r_ctl.rc_last_output_to)) {
19671 		/* We are delayed */
19672 		delayed = cts - rack->r_ctl.rc_last_output_to;
19673 	} else {
19674 		delayed = 0;
19675 	}
19676 	/* Do the timers, which may override the pacer */
19677 	if (rack->r_ctl.rc_hpts_flags & PACE_TMR_MASK) {
19678 		int retval;
19679 
19680 		retval = rack_process_timers(tp, rack, cts, hpts_calling,
19681 					     &doing_tlp);
19682 		if (retval != 0) {
19683 			counter_u64_add(rack_out_size[TCP_MSS_ACCT_ATIMER], 1);
19684 #ifdef TCP_ACCOUNTING
19685 			sched_unpin();
19686 #endif
19687 			/*
19688 			 * If timers want tcp_drop(), then pass error out,
19689 			 * otherwise suppress it.
19690 			 */
19691 			return (retval < 0 ? retval : 0);
19692 		}
19693 	}
19694 	if (rack->rc_in_persist) {
19695 		if (tcp_in_hpts(rack->rc_tp) == 0) {
19696 			/* Timer is not running */
19697 			rack_start_hpts_timer(rack, tp, cts, 0, 0, 0);
19698 		}
19699 #ifdef TCP_ACCOUNTING
19700 		sched_unpin();
19701 #endif
19702 		return (0);
19703 	}
19704 	if ((rack->rc_ack_required == 1) &&
19705 	    (rack->r_timer_override == 0)){
19706 		/* A timeout occurred and no ack has arrived */
19707 		if (tcp_in_hpts(rack->rc_tp) == 0) {
19708 			/* Timer is not running */
19709 			rack_start_hpts_timer(rack, tp, cts, 0, 0, 0);
19710 		}
19711 #ifdef TCP_ACCOUNTING
19712 		sched_unpin();
19713 #endif
19714 		return (0);
19715 	}
19716 	if ((rack->r_timer_override) ||
19717 	    (rack->rc_ack_can_sendout_data) ||
19718 	    (delayed) ||
19719 	    (tp->t_state < TCPS_ESTABLISHED)) {
19720 		rack->rc_ack_can_sendout_data = 0;
19721 		if (tcp_in_hpts(rack->rc_tp))
19722 			tcp_hpts_remove(rack->rc_tp);
19723 	} else if (tcp_in_hpts(rack->rc_tp)) {
19724 		/*
19725 		 * On the hpts you can't pass even if ACKNOW is on, we will
19726 		 * when the hpts fires.
19727 		 */
19728 #ifdef TCP_ACCOUNTING
19729 		crtsc = get_cyclecount();
19730 		if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
19731 			tp->tcp_proc_time[SND_BLOCKED] += (crtsc - ts_val);
19732 			tp->tcp_cnt_counters[SND_BLOCKED]++;
19733 		}
19734 		sched_unpin();
19735 #endif
19736 		counter_u64_add(rack_out_size[TCP_MSS_ACCT_INPACE], 1);
19737 		return (0);
19738 	}
19739 	/* Finish out both pacing early and late accounting */
19740 	if ((rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT) &&
19741 	    TSTMP_GT(rack->r_ctl.rc_last_output_to, cts)) {
19742 		early = rack->r_ctl.rc_last_output_to - cts;
19743 	} else
19744 		early = 0;
19745 	if (delayed && (rack->rc_always_pace == 1)) {
19746 		rack->r_ctl.rc_agg_delayed += delayed;
19747 		rack->r_late = 1;
19748 	} else if (early && (rack->rc_always_pace == 1)) {
19749 		rack->r_ctl.rc_agg_early += early;
19750 		rack->r_early = 1;
19751 	} else if (rack->rc_always_pace == 0) {
19752 		/* Non-paced we are not late */
19753 		rack->r_ctl.rc_agg_delayed = rack->r_ctl.rc_agg_early = 0;
19754 		rack->r_early = rack->r_late = 0;
19755 	}
19756 	/* Now that early/late accounting is done turn off the flag */
19757 	rack->r_ctl.rc_hpts_flags &= ~PACE_PKT_OUTPUT;
19758 	rack->r_wanted_output = 0;
19759 	rack->r_timer_override = 0;
19760 	if ((tp->t_state != rack->r_state) &&
19761 	    TCPS_HAVEESTABLISHED(tp->t_state)) {
19762 		rack_set_state(tp, rack);
19763 	}
19764 	segsiz = min(ctf_fixed_maxseg(tp), rack->r_ctl.rc_pace_min_segs);
19765 	minseg = segsiz;
19766 	if (rack->r_ctl.rc_pace_max_segs == 0)
19767 		pace_max_seg = rack->rc_user_set_max_segs * segsiz;
19768 	else
19769 		pace_max_seg = rack->r_ctl.rc_pace_max_segs;
19770 	if ((rack->r_fast_output) &&
19771 	    (doing_tlp == 0) &&
19772 	    (tp->rcv_numsacks == 0)) {
19773 		int ret;
19774 
19775 		error = 0;
19776 		ret = rack_fast_output(tp, rack, ts_val, cts, ms_cts, &tv, &tot_len_this_send, &error, __LINE__);
19777 		if (ret > 0)
19778 			return(ret);
19779 		else if (error) {
19780 			inp = rack->rc_inp;
19781 			so = inp->inp_socket;
19782 			sb = &so->so_snd;
19783 			goto nomore;
19784 		} else {
19785 			/* Return == 0, if there is more we can send tot_len wise fall through and send */
19786 			if (tot_len_this_send >= pace_max_seg)
19787 				return (ret);
19788 #ifdef TCP_ACCOUNTING
19789 			/* We need to re-pin since fast_output un-pined */
19790 			sched_pin();
19791 			ts_val = get_cyclecount();
19792 #endif
19793 			/* Fall back out so we can send any more that may bring us to pace_max_seg */
19794 		}
19795 	}
19796 	inp = rack->rc_inp;
19797 	/*
19798 	 * For TFO connections in SYN_SENT or SYN_RECEIVED,
19799 	 * only allow the initial SYN or SYN|ACK and those sent
19800 	 * by the retransmit timer.
19801 	 */
19802 	if ((tp->t_flags & TF_FASTOPEN) &&
19803 	    ((tp->t_state == TCPS_SYN_RECEIVED) ||
19804 	     (tp->t_state == TCPS_SYN_SENT)) &&
19805 	    SEQ_GT(tp->snd_max, tp->snd_una) && /* initial SYN or SYN|ACK sent */
19806 	    (tp->t_rxtshift == 0)) {              /* not a retransmit */
19807 		rack_start_hpts_timer(rack, tp, cts, 0, 0, 0);
19808 #ifdef TCP_ACCOUNTING
19809 		sched_unpin();
19810 #endif
19811 		return (0);
19812 	}
19813 	/*
19814 	 * Determine length of data that should be transmitted, and flags
19815 	 * that will be used. If there is some data or critical controls
19816 	 * (SYN, RST) to send, then transmit; otherwise, investigate
19817 	 * further.
19818 	 */
19819 	idle = (tp->t_flags & TF_LASTIDLE) || (tp->snd_max == tp->snd_una);
19820 	if (tp->t_idle_reduce) {
19821 		if (idle && (TICKS_2_USEC(ticks - tp->t_rcvtime) >= tp->t_rxtcur))
19822 			rack_cc_after_idle(rack, tp);
19823 	}
19824 	tp->t_flags &= ~TF_LASTIDLE;
19825 	if (idle) {
19826 		if (tp->t_flags & TF_MORETOCOME) {
19827 			tp->t_flags |= TF_LASTIDLE;
19828 			idle = 0;
19829 		}
19830 	}
19831 	if ((tp->snd_una == tp->snd_max) &&
19832 	    rack->r_ctl.rc_went_idle_time &&
19833 	    (cts > rack->r_ctl.rc_went_idle_time)) {
19834 		tot_idle = (cts - rack->r_ctl.rc_went_idle_time);
19835 		if (tot_idle > rack_min_probertt_hold) {
19836 			/* Count as a probe rtt */
19837 			if (rack->in_probe_rtt == 0) {
19838 				rack->r_ctl.rc_lower_rtt_us_cts = cts;
19839 				rack->r_ctl.rc_time_probertt_entered = rack->r_ctl.rc_lower_rtt_us_cts;
19840 				rack->r_ctl.rc_time_probertt_starts = rack->r_ctl.rc_lower_rtt_us_cts;
19841 				rack->r_ctl.rc_time_of_last_probertt = rack->r_ctl.rc_lower_rtt_us_cts;
19842 			} else {
19843 				rack_exit_probertt(rack, cts);
19844 			}
19845 		}
19846 	} else
19847 		tot_idle = 0;
19848 	if (rack_use_fsb &&
19849 	    (rack->r_ctl.fsb.tcp_ip_hdr) &&
19850 	    (rack->r_fsb_inited == 0) &&
19851 	    (rack->r_state != TCPS_CLOSED))
19852 		rack_init_fsb_block(tp, rack, tcp_outflags[tp->t_state]);
19853 	if (rack->rc_sendvars_notset == 1) {
19854 		rack->rc_sendvars_notset = 0;
19855 		/*
19856 		 * Make sure any TCP timers (keep-alive) is not running.
19857 		 */
19858 		tcp_timer_stop(tp);
19859 	}
19860 	if ((rack->rack_no_prr == 1) &&
19861 	    (rack->rc_always_pace == 0)) {
19862 		/*
19863 		 * Sanity check before sending, if we have
19864 		 * no-pacing enabled and prr is turned off that
19865 		 * is a logistics error. Correct this by turnning
19866 		 * prr back on. A user *must* set some form of
19867 		 * pacing in order to turn PRR off. We do this
19868 		 * in the output path so that we can avoid socket
19869 		 * option ordering issues that would occur if we
19870 		 * tried to do it while setting rack_no_prr on.
19871 		 */
19872 		rack->rack_no_prr = 0;
19873 	}
19874 	if ((rack->pcm_enabled == 1) &&
19875 	    (rack->pcm_needed == 0) &&
19876 	    (tot_idle > 0)) {
19877 		/*
19878 		 * We have been idle some micro seconds. We need
19879 		 * to factor this in to see if a PCM is needed.
19880 		 */
19881 		uint32_t rtts_idle, rnds;
19882 
19883 		if (tp->t_srtt)
19884 			rtts_idle = tot_idle / tp->t_srtt;
19885 		else
19886 			rtts_idle = 0;
19887 		rnds = rack->r_ctl.current_round - rack->r_ctl.last_pcm_round;
19888 		rack->r_ctl.pcm_idle_rounds += rtts_idle;
19889 		if ((rnds + rack->r_ctl.pcm_idle_rounds)  >= rack_pcm_every_n_rounds) {
19890 			rack->pcm_needed = 1;
19891 			rack_log_pcm(rack, 8, rack->r_ctl.last_pcm_round, rtts_idle, rack->r_ctl.current_round );
19892 		}
19893 	}
19894 again:
19895 	sendalot = 0;
19896 	cts = tcp_get_usecs(&tv);
19897 	ms_cts = tcp_tv_to_msec(&tv);
19898 	tso = 0;
19899 	mtu = 0;
19900 	if (TCPS_HAVEESTABLISHED(tp->t_state) &&
19901 	    (rack->r_ctl.pcm_max_seg == 0)) {
19902 		/*
19903 		 * We set in our first send so we know that the ctf_fixed_maxseg
19904 		 * has been fully set. If we do it in rack_init() we most likely
19905 		 * see 512 bytes so we end up at 5120, not desirable.
19906 		 */
19907 		rack->r_ctl.pcm_max_seg = rc_init_window(rack);
19908 		if (rack->r_ctl.pcm_max_seg < (ctf_fixed_maxseg(tp) * 10)) {
19909 			/*
19910 			 * Assure our initial PCM probe is at least 10 MSS.
19911 			 */
19912 			rack->r_ctl.pcm_max_seg = ctf_fixed_maxseg(tp) * 10;
19913 		}
19914 	}
19915 	if ((rack->r_ctl.pcm_max_seg != 0) && (rack->pcm_needed == 1)) {
19916 		uint32_t rw_avail, cwa;
19917 
19918 		if (tp->snd_wnd > ctf_outstanding(tp))
19919 			rw_avail = tp->snd_wnd - ctf_outstanding(tp);
19920 		else
19921 			rw_avail = 0;
19922 		if (tp->snd_cwnd > ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked))
19923 			cwa = tp->snd_cwnd -ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
19924 		else
19925 			cwa = 0;
19926 		if ((cwa >= rack->r_ctl.pcm_max_seg) &&
19927 		    (rw_avail > rack->r_ctl.pcm_max_seg)) {
19928 			/* Raise up the max seg for this trip through */
19929 			pace_max_seg = rack->r_ctl.pcm_max_seg;
19930 			/* Disable any fast output */
19931 			rack->r_fast_output = 0;
19932 		}
19933 		if (rack_verbose_logging) {
19934 			rack_log_pcm(rack, 4,
19935 				     cwa, rack->r_ctl.pcm_max_seg, rw_avail);
19936 		}
19937 	}
19938 	sb_offset = tp->snd_max - tp->snd_una;
19939 	cwnd_to_use = rack->r_ctl.cwnd_to_use = tp->snd_cwnd;
19940 	flags = tcp_outflags[tp->t_state];
19941 	while (rack->rc_free_cnt < rack_free_cache) {
19942 		rsm = rack_alloc(rack);
19943 		if (rsm == NULL) {
19944 			if (hpts_calling)
19945 				/* Retry in a ms */
19946 				pacing_delay = (1 * HPTS_USEC_IN_MSEC);
19947 			so = inp->inp_socket;
19948 			sb = &so->so_snd;
19949 			goto just_return_nolock;
19950 		}
19951 		TAILQ_INSERT_TAIL(&rack->r_ctl.rc_free, rsm, r_tnext);
19952 		rack->rc_free_cnt++;
19953 		rsm = NULL;
19954 	}
19955 	sack_rxmit = 0;
19956 	len = 0;
19957 	rsm = NULL;
19958 	if (flags & TH_RST) {
19959 		SOCK_SENDBUF_LOCK(inp->inp_socket);
19960 		so = inp->inp_socket;
19961 		sb = &so->so_snd;
19962 		goto send;
19963 	}
19964 	if (rack->r_ctl.rc_resend) {
19965 		/* Retransmit timer */
19966 		rsm = rack->r_ctl.rc_resend;
19967 		rack->r_ctl.rc_resend = NULL;
19968 		len = rsm->r_end - rsm->r_start;
19969 		sack_rxmit = 1;
19970 		sendalot = 0;
19971 		KASSERT(SEQ_LEQ(tp->snd_una, rsm->r_start),
19972 			("%s:%d: r.start:%u < SND.UNA:%u; tp:%p, rack:%p, rsm:%p",
19973 			 __func__, __LINE__,
19974 			 rsm->r_start, tp->snd_una, tp, rack, rsm));
19975 		sb_offset = rsm->r_start - tp->snd_una;
19976 		rack_validate_sizes(rack, &len, segsiz, pace_max_seg);
19977 	} else if (rack->r_collapse_point_valid &&
19978 		   ((rsm = rack_check_collapsed(rack, cts)) != NULL)) {
19979 		/*
19980 		 * If an RSM is returned then enough time has passed
19981 		 * for us to retransmit it. Move up the collapse point,
19982 		 * since this rsm has its chance to retransmit now.
19983 		 */
19984 		tcp_trace_point(rack->rc_tp, TCP_TP_COLLAPSED_RXT);
19985 		rack->r_ctl.last_collapse_point = rsm->r_end;
19986 		/* Are we done? */
19987 		if (SEQ_GEQ(rack->r_ctl.last_collapse_point,
19988 			    rack->r_ctl.high_collapse_point))
19989 			rack->r_collapse_point_valid = 0;
19990 		sack_rxmit = 1;
19991 		/* We are not doing a TLP */
19992 		doing_tlp = 0;
19993 		len = rsm->r_end - rsm->r_start;
19994 		sb_offset = rsm->r_start - tp->snd_una;
19995 		sendalot = 0;
19996 		rack_validate_sizes(rack, &len, segsiz, pace_max_seg);
19997 	} else if ((rsm = tcp_rack_output(tp, rack, cts)) != NULL) {
19998 		/* We have a retransmit that takes precedence */
19999 		if ((!IN_FASTRECOVERY(tp->t_flags)) &&
20000 		    ((rsm->r_flags & RACK_MUST_RXT) == 0) &&
20001 		    ((tp->t_flags & TF_WASFRECOVERY) == 0)) {
20002 			/* Enter recovery if not induced by a time-out */
20003 			rack_cong_signal(tp, CC_NDUPACK, tp->snd_una, __LINE__);
20004 		}
20005 #ifdef INVARIANTS
20006 		if (SEQ_LT(rsm->r_start, tp->snd_una)) {
20007 			panic("Huh, tp:%p rack:%p rsm:%p start:%u < snd_una:%u\n",
20008 			      tp, rack, rsm, rsm->r_start, tp->snd_una);
20009 		}
20010 #endif
20011 		len = rsm->r_end - rsm->r_start;
20012 		KASSERT(SEQ_LEQ(tp->snd_una, rsm->r_start),
20013 			("%s:%d: r.start:%u < SND.UNA:%u; tp:%p, rack:%p, rsm:%p",
20014 			 __func__, __LINE__,
20015 			 rsm->r_start, tp->snd_una, tp, rack, rsm));
20016 		sb_offset = rsm->r_start - tp->snd_una;
20017 		sendalot = 0;
20018 		rack_validate_sizes(rack, &len, segsiz, pace_max_seg);
20019 		if (len > 0) {
20020 			sack_rxmit = 1;
20021 			KMOD_TCPSTAT_INC(tcps_sack_rexmits);
20022 			KMOD_TCPSTAT_ADD(tcps_sack_rexmit_bytes,
20023 					 min(len, segsiz));
20024 		}
20025 	} else if (rack->r_ctl.rc_tlpsend) {
20026 		/* Tail loss probe */
20027 		long cwin;
20028 		long tlen;
20029 
20030 		/*
20031 		 * Check if we can do a TLP with a RACK'd packet
20032 		 * this can happen if we are not doing the rack
20033 		 * cheat and we skipped to a TLP and it
20034 		 * went off.
20035 		 */
20036 		rsm = rack->r_ctl.rc_tlpsend;
20037 		/* We are doing a TLP make sure the flag is preent */
20038 		rsm->r_flags |= RACK_TLP;
20039 		rack->r_ctl.rc_tlpsend = NULL;
20040 		sack_rxmit = 1;
20041 		tlen = rsm->r_end - rsm->r_start;
20042 		if (tlen > segsiz)
20043 			tlen = segsiz;
20044 		KASSERT(SEQ_LEQ(tp->snd_una, rsm->r_start),
20045 			("%s:%d: r.start:%u < SND.UNA:%u; tp:%p, rack:%p, rsm:%p",
20046 			 __func__, __LINE__,
20047 			 rsm->r_start, tp->snd_una, tp, rack, rsm));
20048 		sb_offset = rsm->r_start - tp->snd_una;
20049 		cwin = min(tp->snd_wnd, tlen);
20050 		len = cwin;
20051 	}
20052 	if (rack->r_must_retran &&
20053 	    (doing_tlp == 0) &&
20054 	    (SEQ_GT(tp->snd_max, tp->snd_una)) &&
20055 	    (rsm == NULL)) {
20056 		/*
20057 		 * There are two different ways that we
20058 		 * can get into this block:
20059 		 * a) This is a non-sack connection, we had a time-out
20060 		 *    and thus r_must_retran was set and everything
20061 		 *    left outstanding as been marked for retransmit.
20062 		 * b) The MTU of the path shrank, so that everything
20063 		 *    was marked to be retransmitted with the smaller
20064 		 *    mtu and r_must_retran was set.
20065 		 *
20066 		 * This means that we expect the sendmap (outstanding)
20067 		 * to all be marked must. We can use the tmap to
20068 		 * look at them.
20069 		 *
20070 		 */
20071 		int sendwin, flight;
20072 
20073 		sendwin = min(tp->snd_wnd, tp->snd_cwnd);
20074 		flight = ctf_flight_size(tp, rack->r_ctl.rc_out_at_rto);
20075 		if (flight >= sendwin) {
20076 			/*
20077 			 * We can't send yet.
20078 			 */
20079 			so = inp->inp_socket;
20080 			sb = &so->so_snd;
20081 			goto just_return_nolock;
20082 		}
20083 		/*
20084 		 * This is the case a/b mentioned above. All
20085 		 * outstanding/not-acked should be marked.
20086 		 * We can use the tmap to find them.
20087 		 */
20088 		rsm = TAILQ_FIRST(&rack->r_ctl.rc_tmap);
20089 		if (rsm == NULL) {
20090 			/* TSNH */
20091 			rack->r_must_retran = 0;
20092 			rack->r_ctl.rc_out_at_rto = 0;
20093 			so = inp->inp_socket;
20094 			sb = &so->so_snd;
20095 			goto just_return_nolock;
20096 		}
20097 		if ((rsm->r_flags & RACK_MUST_RXT) == 0) {
20098 			/*
20099 			 * The first one does not have the flag, did we collapse
20100 			 * further up in our list?
20101 			 */
20102 			rack->r_must_retran = 0;
20103 			rack->r_ctl.rc_out_at_rto = 0;
20104 			rsm = NULL;
20105 			sack_rxmit = 0;
20106 		} else {
20107 			sack_rxmit = 1;
20108 			len = rsm->r_end - rsm->r_start;
20109 			sb_offset = rsm->r_start - tp->snd_una;
20110 			sendalot = 0;
20111 			if ((rack->full_size_rxt == 0) &&
20112 			    (rack->shape_rxt_to_pacing_min == 0) &&
20113 			    (len >= segsiz))
20114 				len = segsiz;
20115 			else if (rack->shape_rxt_to_pacing_min &&
20116 				 rack->gp_ready) {
20117 				/* We use pacing min as shaping len req */
20118 				uint32_t maxlen;
20119 
20120 				maxlen = rack_get_hpts_pacing_min_for_bw(rack, segsiz);
20121 				if (len > maxlen)
20122 					len = maxlen;
20123 			}
20124 			/*
20125 			 * Delay removing the flag RACK_MUST_RXT so
20126 			 * that the fastpath for retransmit will
20127 			 * work with this rsm.
20128 			 */
20129 		}
20130 	}
20131 	/*
20132 	 * Enforce a connection sendmap count limit if set
20133 	 * as long as we are not retransmiting.
20134 	 */
20135 	if ((rsm == NULL) &&
20136 	    (V_tcp_map_entries_limit > 0) &&
20137 	    (rack->r_ctl.rc_num_maps_alloced >= V_tcp_map_entries_limit)) {
20138 		counter_u64_add(rack_to_alloc_limited, 1);
20139 		if (!rack->alloc_limit_reported) {
20140 			rack->alloc_limit_reported = 1;
20141 			counter_u64_add(rack_alloc_limited_conns, 1);
20142 		}
20143 		so = inp->inp_socket;
20144 		sb = &so->so_snd;
20145 		goto just_return_nolock;
20146 	}
20147 	if (rsm && (rsm->r_flags & RACK_HAS_FIN)) {
20148 		/* we are retransmitting the fin */
20149 		len--;
20150 		if (len) {
20151 			/*
20152 			 * When retransmitting data do *not* include the
20153 			 * FIN. This could happen from a TLP probe.
20154 			 */
20155 			flags &= ~TH_FIN;
20156 		}
20157 	}
20158 	if (rsm && rack->r_fsb_inited &&
20159 	    rack_use_rsm_rfo &&
20160 	    ((rsm->r_flags & RACK_HAS_FIN) == 0)) {
20161 		int ret;
20162 
20163 		ret = rack_fast_rsm_output(tp, rack, rsm, ts_val, cts, ms_cts, &tv, len, doing_tlp);
20164 		if (ret == 0)
20165 			return (0);
20166 	}
20167 	so = inp->inp_socket;
20168 	sb = &so->so_snd;
20169 	if (do_a_prefetch == 0) {
20170 		kern_prefetch(sb, &do_a_prefetch);
20171 		do_a_prefetch = 1;
20172 	}
20173 #ifdef NETFLIX_SHARED_CWND
20174 	if ((tp->t_flags2 & TF2_TCP_SCWND_ALLOWED) &&
20175 	    rack->rack_enable_scwnd) {
20176 		/* We are doing cwnd sharing */
20177 		if (rack->gp_ready &&
20178 		    (rack->rack_attempted_scwnd == 0) &&
20179 		    (rack->r_ctl.rc_scw == NULL) &&
20180 		    tp->t_lib) {
20181 			/* The pcbid is in, lets make an attempt */
20182 			counter_u64_add(rack_try_scwnd, 1);
20183 			rack->rack_attempted_scwnd = 1;
20184 			rack->r_ctl.rc_scw = tcp_shared_cwnd_alloc(tp,
20185 								   &rack->r_ctl.rc_scw_index,
20186 								   segsiz);
20187 		}
20188 		if (rack->r_ctl.rc_scw &&
20189 		    (rack->rack_scwnd_is_idle == 1) &&
20190 		    sbavail(&so->so_snd)) {
20191 			/* we are no longer out of data */
20192 			tcp_shared_cwnd_active(rack->r_ctl.rc_scw, rack->r_ctl.rc_scw_index);
20193 			rack->rack_scwnd_is_idle = 0;
20194 		}
20195 		if (rack->r_ctl.rc_scw) {
20196 			/* First lets update and get the cwnd */
20197 			rack->r_ctl.cwnd_to_use = cwnd_to_use = tcp_shared_cwnd_update(rack->r_ctl.rc_scw,
20198 										       rack->r_ctl.rc_scw_index,
20199 										       tp->snd_cwnd, tp->snd_wnd, segsiz);
20200 		}
20201 	}
20202 #endif
20203 	/*
20204 	 * Get standard flags, and add SYN or FIN if requested by 'hidden'
20205 	 * state flags.
20206 	 */
20207 	if (tp->t_flags & TF_NEEDFIN)
20208 		flags |= TH_FIN;
20209 	if (tp->t_flags & TF_NEEDSYN)
20210 		flags |= TH_SYN;
20211 	if ((sack_rxmit == 0) && (prefetch_rsm == 0)) {
20212 		void *end_rsm;
20213 		end_rsm = TAILQ_LAST_FAST(&rack->r_ctl.rc_tmap, rack_sendmap, r_tnext);
20214 		if (end_rsm)
20215 			kern_prefetch(end_rsm, &prefetch_rsm);
20216 		prefetch_rsm = 1;
20217 	}
20218 	SOCK_SENDBUF_LOCK(so);
20219 	if ((sack_rxmit == 0) &&
20220 	    (TCPS_HAVEESTABLISHED(tp->t_state) ||
20221 	    (tp->t_flags & TF_FASTOPEN))) {
20222 		/*
20223 		 * We are not retransmitting (sack_rxmit is 0) so we
20224 		 * are sending new data. This is always based on snd_max.
20225 		 * Now in theory snd_max may be equal to snd_una, if so
20226 		 * then nothing is outstanding and the offset would be 0.
20227 		 */
20228 		uint32_t avail;
20229 
20230 		avail = sbavail(sb);
20231 		if (SEQ_GT(tp->snd_max, tp->snd_una) && avail)
20232 			sb_offset = tp->snd_max - tp->snd_una;
20233 		else
20234 			sb_offset = 0;
20235 		if ((IN_FASTRECOVERY(tp->t_flags) == 0) || rack->rack_no_prr) {
20236 			if (rack->r_ctl.rc_tlp_new_data) {
20237 				/* TLP is forcing out new data */
20238 				if (rack->r_ctl.rc_tlp_new_data > (uint32_t) (avail - sb_offset)) {
20239 					rack->r_ctl.rc_tlp_new_data = (uint32_t) (avail - sb_offset);
20240 				}
20241 				if ((rack->r_ctl.rc_tlp_new_data + sb_offset) > tp->snd_wnd) {
20242 					if (tp->snd_wnd > sb_offset)
20243 						len = tp->snd_wnd - sb_offset;
20244 					else
20245 						len = 0;
20246 				} else {
20247 					len = rack->r_ctl.rc_tlp_new_data;
20248 				}
20249 				rack->r_ctl.rc_tlp_new_data = 0;
20250 			}  else {
20251 				len = rack_what_can_we_send(tp, rack, cwnd_to_use, avail, sb_offset);
20252 			}
20253 			if ((rack->r_ctl.crte == NULL) &&
20254 			    IN_FASTRECOVERY(tp->t_flags) &&
20255 			    (rack->full_size_rxt == 0) &&
20256 			    (rack->shape_rxt_to_pacing_min == 0) &&
20257 			    (len > segsiz)) {
20258 				/*
20259 				 * For prr=off, we need to send only 1 MSS
20260 				 * at a time. We do this because another sack could
20261 				 * be arriving that causes us to send retransmits and
20262 				 * we don't want to be on a long pace due to a larger send
20263 				 * that keeps us from sending out the retransmit.
20264 				 */
20265 				len = segsiz;
20266 			} else if (rack->shape_rxt_to_pacing_min &&
20267 				   rack->gp_ready) {
20268 				/* We use pacing min as shaping len req */
20269 				uint32_t maxlen;
20270 
20271 				maxlen = rack_get_hpts_pacing_min_for_bw(rack, segsiz);
20272 				if (len > maxlen)
20273 					len = maxlen;
20274 			}/* The else is full_size_rxt is on so send it all */
20275 		} else {
20276 			uint32_t outstanding;
20277 			/*
20278 			 * We are inside of a Fast recovery episode, this
20279 			 * is caused by a SACK or 3 dup acks. At this point
20280 			 * we have sent all the retransmissions and we rely
20281 			 * on PRR to dictate what we will send in the form of
20282 			 * new data.
20283 			 */
20284 
20285 			outstanding = tp->snd_max - tp->snd_una;
20286 			if ((rack->r_ctl.rc_prr_sndcnt + outstanding) > tp->snd_wnd) {
20287 				if (tp->snd_wnd > outstanding) {
20288 					len = tp->snd_wnd - outstanding;
20289 					/* Check to see if we have the data */
20290 					if ((sb_offset + len) > avail) {
20291 						/* It does not all fit */
20292 						if (avail > sb_offset)
20293 							len = avail - sb_offset;
20294 						else
20295 							len = 0;
20296 					}
20297 				} else {
20298 					len = 0;
20299 				}
20300 			} else if (avail > sb_offset) {
20301 				len = avail - sb_offset;
20302 			} else {
20303 				len = 0;
20304 			}
20305 			if (len > 0) {
20306 				if (len > rack->r_ctl.rc_prr_sndcnt) {
20307 					len = rack->r_ctl.rc_prr_sndcnt;
20308 				}
20309 				if (len > 0) {
20310 					sub_from_prr = 1;
20311 				}
20312 			}
20313 			if (len > segsiz) {
20314 				/*
20315 				 * We should never send more than a MSS when
20316 				 * retransmitting or sending new data in prr
20317 				 * mode unless the override flag is on. Most
20318 				 * likely the PRR algorithm is not going to
20319 				 * let us send a lot as well :-)
20320 				 */
20321 				if (rack->r_ctl.rc_prr_sendalot == 0) {
20322 					len = segsiz;
20323 				}
20324 			} else if (len < segsiz) {
20325 				/*
20326 				 * Do we send any? The idea here is if the
20327 				 * send empty's the socket buffer we want to
20328 				 * do it. However if not then lets just wait
20329 				 * for our prr_sndcnt to get bigger.
20330 				 */
20331 				long leftinsb;
20332 
20333 				leftinsb = sbavail(sb) - sb_offset;
20334 				if (leftinsb > len) {
20335 					/* This send does not empty the sb */
20336 					len = 0;
20337 				}
20338 			}
20339 		}
20340 	} else if (!TCPS_HAVEESTABLISHED(tp->t_state)) {
20341 		/*
20342 		 * If you have not established
20343 		 * and are not doing FAST OPEN
20344 		 * no data please.
20345 		 */
20346 		if ((sack_rxmit == 0) &&
20347 		    !(tp->t_flags & TF_FASTOPEN)) {
20348 			len = 0;
20349 			sb_offset = 0;
20350 		}
20351 	}
20352 	if (prefetch_so_done == 0) {
20353 		kern_prefetch(so, &prefetch_so_done);
20354 		prefetch_so_done = 1;
20355 	}
20356 	orig_len = len;
20357 	/*
20358 	 * Lop off SYN bit if it has already been sent.  However, if this is
20359 	 * SYN-SENT state and if segment contains data and if we don't know
20360 	 * that foreign host supports TAO, suppress sending segment.
20361 	 */
20362 	if ((flags & TH_SYN) &&
20363 	    SEQ_GT(tp->snd_max, tp->snd_una) &&
20364 	    ((sack_rxmit == 0) &&
20365 	     (tp->t_rxtshift == 0))) {
20366 		/*
20367 		 * When sending additional segments following a TFO SYN|ACK,
20368 		 * do not include the SYN bit.
20369 		 */
20370 		if ((tp->t_flags & TF_FASTOPEN) &&
20371 		    (tp->t_state == TCPS_SYN_RECEIVED))
20372 			flags &= ~TH_SYN;
20373 	}
20374 	/*
20375 	 * Be careful not to send data and/or FIN on SYN segments. This
20376 	 * measure is needed to prevent interoperability problems with not
20377 	 * fully conformant TCP implementations.
20378 	 */
20379 	if ((flags & TH_SYN) && (tp->t_flags & TF_NOOPT)) {
20380 		len = 0;
20381 		flags &= ~TH_FIN;
20382 	}
20383 	/*
20384 	 * On TFO sockets, ensure no data is sent in the following cases:
20385 	 *
20386 	 *  - When retransmitting SYN|ACK on a passively-created socket
20387 	 *
20388 	 *  - When retransmitting SYN on an actively created socket
20389 	 *
20390 	 *  - When sending a zero-length cookie (cookie request) on an
20391 	 *    actively created socket
20392 	 *
20393 	 *  - When the socket is in the CLOSED state (RST is being sent)
20394 	 */
20395 	if ((tp->t_flags & TF_FASTOPEN) &&
20396 	    (((flags & TH_SYN) && (tp->t_rxtshift > 0)) ||
20397 	     ((tp->t_state == TCPS_SYN_SENT) &&
20398 	      (tp->t_tfo_client_cookie_len == 0)) ||
20399 	     (flags & TH_RST))) {
20400 		sack_rxmit = 0;
20401 		len = 0;
20402 	}
20403 	/* Without fast-open there should never be data sent on a SYN */
20404 	if ((flags & TH_SYN) && !(tp->t_flags & TF_FASTOPEN)) {
20405 		len = 0;
20406 	}
20407 	if ((len > segsiz) && (tcp_dsack_block_exists(tp))) {
20408 		/* We only send 1 MSS if we have a DSACK block */
20409 		add_flag |= RACK_SENT_W_DSACK;
20410 		len = segsiz;
20411 	}
20412 	if (len <= 0) {
20413 		/*
20414 		 * We have nothing to send, or the window shrank, or
20415 		 * is closed, do we need to go into persists?
20416 		 */
20417 		len = 0;
20418 		if ((tp->snd_wnd == 0) &&
20419 		    (TCPS_HAVEESTABLISHED(tp->t_state)) &&
20420 		    (tp->snd_una == tp->snd_max) &&
20421 		    (sb_offset < (int)sbavail(sb))) {
20422 			rack_enter_persist(tp, rack, cts, tp->snd_una);
20423 		}
20424 	} else if ((rsm == NULL) &&
20425 		   (doing_tlp == 0) &&
20426 		   (len < pace_max_seg)) {
20427 		/*
20428 		 * We are not sending a maximum sized segment for
20429 		 * some reason. Should we not send anything (think
20430 		 * sws or persists)?
20431 		 */
20432 		if ((tp->snd_wnd < min((rack->r_ctl.rc_high_rwnd/2), minseg)) &&
20433 		    (TCPS_HAVEESTABLISHED(tp->t_state)) &&
20434 		    (len < minseg) &&
20435 		    (len < (int)(sbavail(sb) - sb_offset))) {
20436 			/*
20437 			 * Here the rwnd is less than
20438 			 * the minimum pacing size, this is not a retransmit,
20439 			 * we are established and
20440 			 * the send is not the last in the socket buffer
20441 			 * we send nothing, and we may enter persists
20442 			 * if nothing is outstanding.
20443 			 */
20444 			len = 0;
20445 			if (tp->snd_max == tp->snd_una) {
20446 				/*
20447 				 * Nothing out we can
20448 				 * go into persists.
20449 				 */
20450 				rack_enter_persist(tp, rack, cts, tp->snd_una);
20451 			}
20452 		} else if ((cwnd_to_use >= max(minseg, (segsiz * 4))) &&
20453 			   (ctf_flight_size(tp, rack->r_ctl.rc_sacked) > (2 * segsiz)) &&
20454 			   (len < (int)(sbavail(sb) - sb_offset)) &&
20455 			   (len < minseg)) {
20456 			/*
20457 			 * Here we are not retransmitting, and
20458 			 * the cwnd is not so small that we could
20459 			 * not send at least a min size (rxt timer
20460 			 * not having gone off), We have 2 segments or
20461 			 * more already in flight, its not the tail end
20462 			 * of the socket buffer  and the cwnd is blocking
20463 			 * us from sending out a minimum pacing segment size.
20464 			 * Lets not send anything.
20465 			 */
20466 			len = 0;
20467 		} else if (((tp->snd_wnd - ctf_outstanding(tp)) <
20468 			    min((rack->r_ctl.rc_high_rwnd/2), minseg)) &&
20469 			   (ctf_flight_size(tp, rack->r_ctl.rc_sacked) > (2 * segsiz)) &&
20470 			   (len < (int)(sbavail(sb) - sb_offset)) &&
20471 			   (TCPS_HAVEESTABLISHED(tp->t_state))) {
20472 			/*
20473 			 * Here we have a send window but we have
20474 			 * filled it up and we can't send another pacing segment.
20475 			 * We also have in flight more than 2 segments
20476 			 * and we are not completing the sb i.e. we allow
20477 			 * the last bytes of the sb to go out even if
20478 			 * its not a full pacing segment.
20479 			 */
20480 			len = 0;
20481 		} else if ((rack->r_ctl.crte != NULL) &&
20482 			   (tp->snd_wnd >= (pace_max_seg * max(1, rack_hw_rwnd_factor))) &&
20483 			   (cwnd_to_use >= (pace_max_seg + (4 * segsiz))) &&
20484 			   (ctf_flight_size(tp, rack->r_ctl.rc_sacked) >= (2 * segsiz)) &&
20485 			   (len < (int)(sbavail(sb) - sb_offset))) {
20486 			/*
20487 			 * Here we are doing hardware pacing, this is not a TLP,
20488 			 * we are not sending a pace max segment size, there is rwnd
20489 			 * room to send at least N pace_max_seg, the cwnd is greater
20490 			 * than or equal to a full pacing segments plus 4 mss and we have 2 or
20491 			 * more segments in flight and its not the tail of the socket buffer.
20492 			 *
20493 			 * We don't want to send instead we need to get more ack's in to
20494 			 * allow us to send a full pacing segment. Normally, if we are pacing
20495 			 * about the right speed, we should have finished our pacing
20496 			 * send as most of the acks have come back if we are at the
20497 			 * right rate. This is a bit fuzzy since return path delay
20498 			 * can delay the acks, which is why we want to make sure we
20499 			 * have cwnd space to have a bit more than a max pace segments in flight.
20500 			 *
20501 			 * If we have not gotten our acks back we are pacing at too high a
20502 			 * rate delaying will not hurt and will bring our GP estimate down by
20503 			 * injecting the delay. If we don't do this we will send
20504 			 * 2 MSS out in response to the acks being clocked in which
20505 			 * defeats the point of hw-pacing (i.e. to help us get
20506 			 * larger TSO's out).
20507 			 */
20508 			len = 0;
20509 		}
20510 
20511 	}
20512 	/* len will be >= 0 after this point. */
20513 	KASSERT(len >= 0, ("[%s:%d]: len < 0", __func__, __LINE__));
20514 	rack_sndbuf_autoscale(rack);
20515 	/*
20516 	 * Decide if we can use TCP Segmentation Offloading (if supported by
20517 	 * hardware).
20518 	 *
20519 	 * TSO may only be used if we are in a pure bulk sending state.  The
20520 	 * presence of TCP-MD5, SACK retransmits, SACK advertizements and IP
20521 	 * options prevent using TSO.  With TSO the TCP header is the same
20522 	 * (except for the sequence number) for all generated packets.  This
20523 	 * makes it impossible to transmit any options which vary per
20524 	 * generated segment or packet.
20525 	 *
20526 	 * IPv4 handling has a clear separation of ip options and ip header
20527 	 * flags while IPv6 combines both in in6p_outputopts. ip6_optlen() does
20528 	 * the right thing below to provide length of just ip options and thus
20529 	 * checking for ipoptlen is enough to decide if ip options are present.
20530 	 */
20531 	ipoptlen = 0;
20532 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
20533 	/*
20534 	 * Pre-calculate here as we save another lookup into the darknesses
20535 	 * of IPsec that way and can actually decide if TSO is ok.
20536 	 */
20537 #ifdef INET6
20538 	if (isipv6 && IPSEC_ENABLED(ipv6))
20539 		ipsec_optlen = IPSEC_HDRSIZE(ipv6, inp);
20540 #ifdef INET
20541 	else
20542 #endif
20543 #endif				/* INET6 */
20544 #ifdef INET
20545 		if (IPSEC_ENABLED(ipv4))
20546 			ipsec_optlen = IPSEC_HDRSIZE(ipv4, inp);
20547 #endif				/* INET */
20548 #endif
20549 
20550 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
20551 	ipoptlen += ipsec_optlen;
20552 #endif
20553 	if ((tp->t_flags & TF_TSO) && V_tcp_do_tso && len > segsiz &&
20554 	    (tp->t_port == 0) &&
20555 	    ((tp->t_flags & TF_SIGNATURE) == 0) &&
20556 	    sack_rxmit == 0 &&
20557 	    ipoptlen == 0)
20558 		tso = 1;
20559 	{
20560 		uint32_t outstanding __unused;
20561 
20562 		outstanding = tp->snd_max - tp->snd_una;
20563 		if (tp->t_flags & TF_SENTFIN) {
20564 			/*
20565 			 * If we sent a fin, snd_max is 1 higher than
20566 			 * snd_una
20567 			 */
20568 			outstanding--;
20569 		}
20570 		if (sack_rxmit) {
20571 			if ((rsm->r_flags & RACK_HAS_FIN) == 0)
20572 				flags &= ~TH_FIN;
20573 		}
20574 	}
20575 	recwin = lmin(lmax(sbspace(&so->so_rcv), 0),
20576 		      (long)TCP_MAXWIN << tp->rcv_scale);
20577 
20578 	/*
20579 	 * Sender silly window avoidance.   We transmit under the following
20580 	 * conditions when len is non-zero:
20581 	 *
20582 	 * - We have a full segment (or more with TSO) - This is the last
20583 	 * buffer in a write()/send() and we are either idle or running
20584 	 * NODELAY - we've timed out (e.g. persist timer) - we have more
20585 	 * then 1/2 the maximum send window's worth of data (receiver may be
20586 	 * limited the window size) - we need to retransmit
20587 	 */
20588 	if (len) {
20589 		if (len >= segsiz) {
20590 			goto send;
20591 		}
20592 		/*
20593 		 * NOTE! on localhost connections an 'ack' from the remote
20594 		 * end may occur synchronously with the output and cause us
20595 		 * to flush a buffer queued with moretocome.  XXX
20596 		 *
20597 		 */
20598 		if (!(tp->t_flags & TF_MORETOCOME) &&	/* normal case */
20599 		    (idle || (tp->t_flags & TF_NODELAY)) &&
20600 		    ((uint32_t)len + (uint32_t)sb_offset >= sbavail(sb)) &&
20601 		    (tp->t_flags & TF_NOPUSH) == 0) {
20602 			pass = 2;
20603 			goto send;
20604 		}
20605 		if ((tp->snd_una == tp->snd_max) && len) {	/* Nothing outstanding */
20606 			pass = 22;
20607 			goto send;
20608 		}
20609 		if (len >= tp->max_sndwnd / 2 && tp->max_sndwnd > 0) {
20610 			pass = 4;
20611 			goto send;
20612 		}
20613 		if (sack_rxmit) {
20614 			pass = 6;
20615 			goto send;
20616 		}
20617 		if (((tp->snd_wnd - ctf_outstanding(tp)) < segsiz) &&
20618 		    (ctf_outstanding(tp) < (segsiz * 2))) {
20619 			/*
20620 			 * We have less than two MSS outstanding (delayed ack)
20621 			 * and our rwnd will not let us send a full sized
20622 			 * MSS. Lets go ahead and let this small segment
20623 			 * out because we want to try to have at least two
20624 			 * packets inflight to not be caught by delayed ack.
20625 			 */
20626 			pass = 12;
20627 			goto send;
20628 		}
20629 	}
20630 	/*
20631 	 * Sending of standalone window updates.
20632 	 *
20633 	 * Window updates are important when we close our window due to a
20634 	 * full socket buffer and are opening it again after the application
20635 	 * reads data from it.  Once the window has opened again and the
20636 	 * remote end starts to send again the ACK clock takes over and
20637 	 * provides the most current window information.
20638 	 *
20639 	 * We must avoid the silly window syndrome whereas every read from
20640 	 * the receive buffer, no matter how small, causes a window update
20641 	 * to be sent.  We also should avoid sending a flurry of window
20642 	 * updates when the socket buffer had queued a lot of data and the
20643 	 * application is doing small reads.
20644 	 *
20645 	 * Prevent a flurry of pointless window updates by only sending an
20646 	 * update when we can increase the advertized window by more than
20647 	 * 1/4th of the socket buffer capacity.  When the buffer is getting
20648 	 * full or is very small be more aggressive and send an update
20649 	 * whenever we can increase by two mss sized segments. In all other
20650 	 * situations the ACK's to new incoming data will carry further
20651 	 * window increases.
20652 	 *
20653 	 * Don't send an independent window update if a delayed ACK is
20654 	 * pending (it will get piggy-backed on it) or the remote side
20655 	 * already has done a half-close and won't send more data.  Skip
20656 	 * this if the connection is in T/TCP half-open state.
20657 	 */
20658 	if (recwin > 0 && !(tp->t_flags & TF_NEEDSYN) &&
20659 	    !(tp->t_flags & TF_DELACK) &&
20660 	    !TCPS_HAVERCVDFIN(tp->t_state)) {
20661 		/*
20662 		 * "adv" is the amount we could increase the window, taking
20663 		 * into account that we are limited by TCP_MAXWIN <<
20664 		 * tp->rcv_scale.
20665 		 */
20666 		int32_t adv;
20667 		int oldwin;
20668 
20669 		adv = recwin;
20670 		if (SEQ_GT(tp->rcv_adv, tp->rcv_nxt)) {
20671 			oldwin = (tp->rcv_adv - tp->rcv_nxt);
20672 			if (adv > oldwin)
20673 				adv -= oldwin;
20674 			else {
20675 				/* We can't increase the window */
20676 				adv = 0;
20677 			}
20678 		} else
20679 			oldwin = 0;
20680 
20681 		/*
20682 		 * If the new window size ends up being the same as or less
20683 		 * than the old size when it is scaled, then don't force
20684 		 * a window update.
20685 		 */
20686 		if (oldwin >> tp->rcv_scale >= (adv + oldwin) >> tp->rcv_scale)
20687 			goto dontupdate;
20688 
20689 		if (adv >= (int32_t)(2 * segsiz) &&
20690 		    (adv >= (int32_t)(so->so_rcv.sb_hiwat / 4) ||
20691 		     recwin <= (int32_t)(so->so_rcv.sb_hiwat / 8) ||
20692 		     so->so_rcv.sb_hiwat <= 8 * segsiz)) {
20693 			pass = 7;
20694 			goto send;
20695 		}
20696 		if (2 * adv >= (int32_t) so->so_rcv.sb_hiwat) {
20697 			pass = 23;
20698 			goto send;
20699 		}
20700 	}
20701 dontupdate:
20702 
20703 	/*
20704 	 * Send if we owe the peer an ACK, RST, SYN, or urgent data.  ACKNOW
20705 	 * is also a catch-all for the retransmit timer timeout case.
20706 	 */
20707 	if (tp->t_flags & TF_ACKNOW) {
20708 		pass = 8;
20709 		goto send;
20710 	}
20711 	if (((flags & TH_SYN) && (tp->t_flags & TF_NEEDSYN) == 0)) {
20712 		pass = 9;
20713 		goto send;
20714 	}
20715 	/*
20716 	 * If our state indicates that FIN should be sent and we have not
20717 	 * yet done so, then we need to send.
20718 	 */
20719 	if ((flags & TH_FIN) &&
20720 	    (tp->snd_max == tp->snd_una)) {
20721 		pass = 11;
20722 		goto send;
20723 	}
20724 	/*
20725 	 * No reason to send a segment, just return.
20726 	 */
20727 just_return:
20728 	SOCK_SENDBUF_UNLOCK(so);
20729 just_return_nolock:
20730 	{
20731 		int app_limited = CTF_JR_SENT_DATA;
20732 
20733 		if ((tp->t_flags & TF_FASTOPEN) == 0 &&
20734 		    (flags & TH_FIN) &&
20735 		    (len == 0) &&
20736 		    (sbused(sb) == (tp->snd_max - tp->snd_una)) &&
20737 		    ((tp->snd_max - tp->snd_una) <= segsiz)) {
20738 			/*
20739 			 * Ok less than or right at a MSS is
20740 			 * outstanding. The original FreeBSD stack would
20741 			 * have sent a FIN, which can speed things up for
20742 			 * a transactional application doing a MSG_WAITALL.
20743 			 * To speed things up since we do *not* send a FIN
20744 			 * if data is outstanding, we send a "challenge ack".
20745 			 * The idea behind that is instead of having to have
20746 			 * the peer wait for the delayed-ack timer to run off
20747 			 * we send an ack that makes the peer send us an ack.
20748 			 *
20749 			 * Note we do not send anything if its been less than
20750 			 * a srtt.
20751 			 */
20752 			uint64_t tmark;
20753 
20754 			tmark = tcp_get_u64_usecs(&tv);
20755 			if ((tmark > rack->r_ctl.lt_timemark) &&
20756 			    (((tmark - rack->r_ctl.lt_timemark) / 1000) > tp->t_srtt)) {
20757 				rack_send_ack_challange(rack);
20758 			}
20759 		}
20760 		if (tot_len_this_send > 0) {
20761 			rack->r_ctl.fsb.recwin = recwin;
20762 			pacing_delay = rack_get_pacing_delay(rack, tp, tot_len_this_send, NULL, segsiz, __LINE__);
20763 			if ((error == 0) &&
20764 			    rack_use_rfo &&
20765 			    ((flags & (TH_SYN|TH_FIN)) == 0) &&
20766 			    (ipoptlen == 0) &&
20767 			    rack->r_fsb_inited &&
20768 			    TCPS_HAVEESTABLISHED(tp->t_state) &&
20769 			    ((IN_RECOVERY(tp->t_flags)) == 0) &&
20770 			    (doing_tlp == 0) &&
20771 			    (rack->r_must_retran == 0) &&
20772 			    ((tp->t_flags & TF_NEEDFIN) == 0) &&
20773 			    (len > 0) && (orig_len > 0) &&
20774 			    (orig_len > len) &&
20775 			    ((orig_len - len) >= segsiz) &&
20776 			    ((optlen == 0) ||
20777 			     ((optlen == TCPOLEN_TSTAMP_APPA) && (to.to_flags & TOF_TS)))) {
20778 				/* We can send at least one more MSS using our fsb */
20779 				rack_setup_fast_output(tp, rack, sb, len, orig_len,
20780 						       segsiz, pace_max_seg, hw_tls, flags);
20781 			} else
20782 				rack->r_fast_output = 0;
20783 			rack_log_fsb(rack, tp, so, flags,
20784 				     ipoptlen, orig_len, len, 0,
20785 				     1, optlen, __LINE__, 1);
20786 			/* Assure when we leave that snd_nxt will point to top */
20787 			if (SEQ_GT(tp->snd_max, tp->snd_nxt))
20788 				tp->snd_nxt = tp->snd_max;
20789 		} else {
20790 			int end_window = 0;
20791 			uint32_t seq = tp->gput_ack;
20792 
20793 			rsm = tqhash_max(rack->r_ctl.tqh);
20794 			if (rsm) {
20795 				/*
20796 				 * Mark the last sent that we just-returned (hinting
20797 				 * that delayed ack may play a role in any rtt measurement).
20798 				 */
20799 				rsm->r_just_ret = 1;
20800 			}
20801 			counter_u64_add(rack_out_size[TCP_MSS_ACCT_JUSTRET], 1);
20802 			rack->r_ctl.rc_agg_delayed = 0;
20803 			rack->r_early = 0;
20804 			rack->r_late = 0;
20805 			rack->r_ctl.rc_agg_early = 0;
20806 			if ((ctf_outstanding(tp) +
20807 			     min(max(segsiz, (rack->r_ctl.rc_high_rwnd/2)),
20808 				 minseg)) >= tp->snd_wnd) {
20809 				/* We are limited by the rwnd */
20810 				app_limited = CTF_JR_RWND_LIMITED;
20811 				if (IN_FASTRECOVERY(tp->t_flags))
20812 					rack->r_ctl.rc_prr_sndcnt = 0;
20813 			} else if (ctf_outstanding(tp) >= sbavail(sb)) {
20814 				/* We are limited by whats available -- app limited */
20815 				app_limited = CTF_JR_APP_LIMITED;
20816 				if (IN_FASTRECOVERY(tp->t_flags))
20817 					rack->r_ctl.rc_prr_sndcnt = 0;
20818 			} else if ((idle == 0) &&
20819 				   ((tp->t_flags & TF_NODELAY) == 0) &&
20820 				   ((uint32_t)len + (uint32_t)sb_offset >= sbavail(sb)) &&
20821 				   (len < segsiz)) {
20822 				/*
20823 				 * No delay is not on and the
20824 				 * user is sending less than 1MSS. This
20825 				 * brings out SWS avoidance so we
20826 				 * don't send. Another app-limited case.
20827 				 */
20828 				app_limited = CTF_JR_APP_LIMITED;
20829 			} else if (tp->t_flags & TF_NOPUSH) {
20830 				/*
20831 				 * The user has requested no push of
20832 				 * the last segment and we are
20833 				 * at the last segment. Another app
20834 				 * limited case.
20835 				 */
20836 				app_limited = CTF_JR_APP_LIMITED;
20837 			} else if ((ctf_outstanding(tp) + minseg) > cwnd_to_use) {
20838 				/* Its the cwnd */
20839 				app_limited = CTF_JR_CWND_LIMITED;
20840 			} else if (IN_FASTRECOVERY(tp->t_flags) &&
20841 				   (rack->rack_no_prr == 0) &&
20842 				   (rack->r_ctl.rc_prr_sndcnt < segsiz)) {
20843 				app_limited = CTF_JR_PRR;
20844 			} else {
20845 				/* Now why here are we not sending? */
20846 #ifdef NOW
20847 #ifdef INVARIANTS
20848 				panic("rack:%p hit JR_ASSESSING case cwnd_to_use:%u?", rack, cwnd_to_use);
20849 #endif
20850 #endif
20851 				app_limited = CTF_JR_ASSESSING;
20852 			}
20853 			/*
20854 			 * App limited in some fashion, for our pacing GP
20855 			 * measurements we don't want any gap (even cwnd).
20856 			 * Close  down the measurement window.
20857 			 */
20858 			if (rack_cwnd_block_ends_measure &&
20859 			    ((app_limited == CTF_JR_CWND_LIMITED) ||
20860 			     (app_limited == CTF_JR_PRR))) {
20861 				/*
20862 				 * The reason we are not sending is
20863 				 * the cwnd (or prr). We have been configured
20864 				 * to end the measurement window in
20865 				 * this case.
20866 				 */
20867 				end_window = 1;
20868 			} else if (rack_rwnd_block_ends_measure &&
20869 				   (app_limited == CTF_JR_RWND_LIMITED)) {
20870 				/*
20871 				 * We are rwnd limited and have been
20872 				 * configured to end the measurement
20873 				 * window in this case.
20874 				 */
20875 				end_window = 1;
20876 			} else if (app_limited == CTF_JR_APP_LIMITED) {
20877 				/*
20878 				 * A true application limited period, we have
20879 				 * ran out of data.
20880 				 */
20881 				end_window = 1;
20882 			} else if (app_limited == CTF_JR_ASSESSING) {
20883 				/*
20884 				 * In the assessing case we hit the end of
20885 				 * the if/else and had no known reason
20886 				 * This will panic us under invariants..
20887 				 *
20888 				 * If we get this out in logs we need to
20889 				 * investagate which reason we missed.
20890 				 */
20891 				end_window = 1;
20892 			}
20893 			if (end_window) {
20894 				uint8_t log = 0;
20895 
20896 				/* Adjust the Gput measurement */
20897 				if ((tp->t_flags & TF_GPUTINPROG) &&
20898 				    SEQ_GT(tp->gput_ack, tp->snd_max)) {
20899 					tp->gput_ack = tp->snd_max;
20900 					if ((tp->gput_ack - tp->gput_seq) < (MIN_GP_WIN * segsiz)) {
20901 						/*
20902 						 * There is not enough to measure.
20903 						 */
20904 						tp->t_flags &= ~TF_GPUTINPROG;
20905 						rack_log_pacing_delay_calc(rack, (tp->gput_ack - tp->gput_seq) /*flex2*/,
20906 									   rack->r_ctl.rc_gp_srtt /*flex1*/,
20907 									   tp->gput_seq,
20908 									   0, 0, 18, __LINE__, NULL, 0);
20909 					} else
20910 						log = 1;
20911 				}
20912 				/* Mark the last packet as app limited */
20913 				rsm = tqhash_max(rack->r_ctl.tqh);
20914 				if (rsm && ((rsm->r_flags & RACK_APP_LIMITED) == 0)) {
20915 					if (rack->r_ctl.rc_app_limited_cnt == 0)
20916 						rack->r_ctl.rc_end_appl = rack->r_ctl.rc_first_appl = rsm;
20917 					else {
20918 						/*
20919 						 * Go out to the end app limited and mark
20920 						 * this new one as next and move the end_appl up
20921 						 * to this guy.
20922 						 */
20923 						if (rack->r_ctl.rc_end_appl)
20924 							rack->r_ctl.rc_end_appl->r_nseq_appl = rsm->r_start;
20925 						rack->r_ctl.rc_end_appl = rsm;
20926 					}
20927 					rsm->r_flags |= RACK_APP_LIMITED;
20928 					rack->r_ctl.rc_app_limited_cnt++;
20929 				}
20930 				if (log)
20931 					rack_log_pacing_delay_calc(rack,
20932 								   rack->r_ctl.rc_app_limited_cnt, seq,
20933 								   tp->gput_ack, 0, 0, 4, __LINE__, NULL, 0);
20934 			}
20935 		}
20936 		/* Check if we need to go into persists or not */
20937 		if ((tp->snd_max == tp->snd_una) &&
20938 		    TCPS_HAVEESTABLISHED(tp->t_state) &&
20939 		    sbavail(sb) &&
20940 		    (sbavail(sb) > tp->snd_wnd) &&
20941 		    (tp->snd_wnd < min((rack->r_ctl.rc_high_rwnd/2), minseg))) {
20942 			/* Yes lets make sure to move to persist before timer-start */
20943 			rack_enter_persist(tp, rack, rack->r_ctl.rc_rcvtime, tp->snd_una);
20944 		}
20945 		rack_start_hpts_timer(rack, tp, cts, pacing_delay, tot_len_this_send, sup_rack);
20946 		rack_log_type_just_return(rack, cts, tot_len_this_send, pacing_delay, hpts_calling, app_limited, cwnd_to_use);
20947 	}
20948 #ifdef NETFLIX_SHARED_CWND
20949 	if ((sbavail(sb) == 0) &&
20950 	    rack->r_ctl.rc_scw) {
20951 		tcp_shared_cwnd_idle(rack->r_ctl.rc_scw, rack->r_ctl.rc_scw_index);
20952 		rack->rack_scwnd_is_idle = 1;
20953 	}
20954 #endif
20955 #ifdef TCP_ACCOUNTING
20956 	if (tot_len_this_send > 0) {
20957 		crtsc = get_cyclecount();
20958 		if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
20959 			tp->tcp_cnt_counters[SND_OUT_DATA]++;
20960 			tp->tcp_proc_time[SND_OUT_DATA] += (crtsc - ts_val);
20961 			tp->tcp_cnt_counters[CNT_OF_MSS_OUT] += ((tot_len_this_send + segsiz - 1) / segsiz);
20962 		}
20963 	} else {
20964 		crtsc = get_cyclecount();
20965 		if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
20966 			tp->tcp_cnt_counters[SND_LIMITED]++;
20967 			tp->tcp_proc_time[SND_LIMITED] += (crtsc - ts_val);
20968 		}
20969 	}
20970 	sched_unpin();
20971 #endif
20972 	return (0);
20973 
20974 send:
20975 	if ((rack->r_ctl.crte != NULL) &&
20976 	    (rsm == NULL) &&
20977 	    ((rack->rc_hw_nobuf == 1) ||
20978 	     (rack_hw_check_queue && (check_done == 0)))) {
20979 		/*
20980 		 * We only want to do this once with the hw_check_queue,
20981 		 * for the enobuf case we would only do it once if
20982 		 * we come around to again, the flag will be clear.
20983 		 */
20984 		check_done = 1;
20985 		pacing_delay = rack_check_queue_level(rack, tp, &tv, cts, len, segsiz);
20986 		if (pacing_delay) {
20987 			rack->r_ctl.rc_agg_delayed = 0;
20988 			rack->r_ctl.rc_agg_early = 0;
20989 			rack->r_early = 0;
20990 			rack->r_late = 0;
20991 			SOCK_SENDBUF_UNLOCK(so);
20992 			goto skip_all_send;
20993 		}
20994 	}
20995 	if (rsm || sack_rxmit)
20996 		counter_u64_add(rack_nfto_resend, 1);
20997 	else
20998 		counter_u64_add(rack_non_fto_send, 1);
20999 	if ((flags & TH_FIN) &&
21000 	    sbavail(sb)) {
21001 		/*
21002 		 * We do not transmit a FIN
21003 		 * with data outstanding. We
21004 		 * need to make it so all data
21005 		 * is acked first.
21006 		 */
21007 		flags &= ~TH_FIN;
21008 		if (TCPS_HAVEESTABLISHED(tp->t_state) &&
21009 		    (sbused(sb) == (tp->snd_max - tp->snd_una)) &&
21010 		    ((tp->snd_max - tp->snd_una) <= segsiz)) {
21011 			/*
21012 			 * Ok less than or right at a MSS is
21013 			 * outstanding. The original FreeBSD stack would
21014 			 * have sent a FIN, which can speed things up for
21015 			 * a transactional application doing a MSG_WAITALL.
21016 			 * To speed things up since we do *not* send a FIN
21017 			 * if data is outstanding, we send a "challenge ack".
21018 			 * The idea behind that is instead of having to have
21019 			 * the peer wait for the delayed-ack timer to run off
21020 			 * we send an ack that makes the peer send us an ack.
21021 			 */
21022 			rack_send_ack_challange(rack);
21023 		}
21024 	}
21025 	/* Enforce stack imposed max seg size if we have one */
21026 	if (pace_max_seg &&
21027 	    (len > pace_max_seg)) {
21028 		mark = 1;
21029 		len = pace_max_seg;
21030 	}
21031 	if ((rsm == NULL) &&
21032 	    (rack->pcm_in_progress == 0) &&
21033 	    (rack->r_ctl.pcm_max_seg > 0) &&
21034 	    (len >= rack->r_ctl.pcm_max_seg)) {
21035 		/* It is large enough for a measurement */
21036 		add_flag |= RACK_IS_PCM;
21037 		rack_log_pcm(rack, 5, len, rack->r_ctl.pcm_max_seg,  add_flag);
21038 	} else if (rack_verbose_logging) {
21039 		rack_log_pcm(rack, 6, len, rack->r_ctl.pcm_max_seg,  add_flag);
21040 	}
21041 
21042 	SOCKBUF_LOCK_ASSERT(sb);
21043 	if (len > 0) {
21044 		if (len >= segsiz)
21045 			tp->t_flags2 |= TF2_PLPMTU_MAXSEGSNT;
21046 		else
21047 			tp->t_flags2 &= ~TF2_PLPMTU_MAXSEGSNT;
21048 	}
21049 	/*
21050 	 * Before ESTABLISHED, force sending of initial options unless TCP
21051 	 * set not to do any options. NOTE: we assume that the IP/TCP header
21052 	 * plus TCP options always fit in a single mbuf, leaving room for a
21053 	 * maximum link header, i.e. max_linkhdr + sizeof (struct tcpiphdr)
21054 	 * + optlen <= MCLBYTES
21055 	 */
21056 	optlen = 0;
21057 #ifdef INET6
21058 	if (isipv6)
21059 		hdrlen = sizeof(struct ip6_hdr) + sizeof(struct tcphdr);
21060 	else
21061 #endif
21062 		hdrlen = sizeof(struct tcpiphdr);
21063 
21064 	/*
21065 	 * Ok what seq are we sending from. If we have
21066 	 * no rsm to use, then we look at various bits,
21067 	 * if we are putting out a SYN it will be ISS.
21068 	 * If we are retransmitting a FIN it will
21069 	 * be snd_max-1 else its snd_max.
21070 	 */
21071 	if (rsm == NULL) {
21072 		if (flags & TH_SYN)
21073 			rack_seq = tp->iss;
21074 		else if ((flags & TH_FIN) &&
21075 			 (tp->t_flags & TF_SENTFIN))
21076 			rack_seq = tp->snd_max - 1;
21077 		else
21078 			rack_seq = tp->snd_max;
21079 	} else {
21080 		rack_seq = rsm->r_start;
21081 	}
21082 	/*
21083 	 * Compute options for segment. We only have to care about SYN and
21084 	 * established connection segments.  Options for SYN-ACK segments
21085 	 * are handled in TCP syncache.
21086 	 */
21087 	to.to_flags = 0;
21088 	if ((tp->t_flags & TF_NOOPT) == 0) {
21089 		/* Maximum segment size. */
21090 		if (flags & TH_SYN) {
21091 			to.to_mss = tcp_mssopt(&inp->inp_inc);
21092 			if (tp->t_port)
21093 				to.to_mss -= V_tcp_udp_tunneling_overhead;
21094 			to.to_flags |= TOF_MSS;
21095 
21096 			/*
21097 			 * On SYN or SYN|ACK transmits on TFO connections,
21098 			 * only include the TFO option if it is not a
21099 			 * retransmit, as the presence of the TFO option may
21100 			 * have caused the original SYN or SYN|ACK to have
21101 			 * been dropped by a middlebox.
21102 			 */
21103 			if ((tp->t_flags & TF_FASTOPEN) &&
21104 			    (tp->t_rxtshift == 0)) {
21105 				if (tp->t_state == TCPS_SYN_RECEIVED) {
21106 					to.to_tfo_len = TCP_FASTOPEN_COOKIE_LEN;
21107 					to.to_tfo_cookie =
21108 						(u_int8_t *)&tp->t_tfo_cookie.server;
21109 					to.to_flags |= TOF_FASTOPEN;
21110 					wanted_cookie = 1;
21111 				} else if (tp->t_state == TCPS_SYN_SENT) {
21112 					to.to_tfo_len =
21113 						tp->t_tfo_client_cookie_len;
21114 					to.to_tfo_cookie =
21115 						tp->t_tfo_cookie.client;
21116 					to.to_flags |= TOF_FASTOPEN;
21117 					wanted_cookie = 1;
21118 					/*
21119 					 * If we wind up having more data to
21120 					 * send with the SYN than can fit in
21121 					 * one segment, don't send any more
21122 					 * until the SYN|ACK comes back from
21123 					 * the other end.
21124 					 */
21125 					sendalot = 0;
21126 				}
21127 			}
21128 		}
21129 		/* Window scaling. */
21130 		if ((flags & TH_SYN) && (tp->t_flags & TF_REQ_SCALE)) {
21131 			to.to_wscale = tp->request_r_scale;
21132 			to.to_flags |= TOF_SCALE;
21133 		}
21134 		/* Timestamps. */
21135 		if ((tp->t_flags & TF_RCVD_TSTMP) ||
21136 		    ((flags & TH_SYN) && (tp->t_flags & TF_REQ_TSTMP))) {
21137 			uint32_t ts_to_use;
21138 
21139 			if ((rack->r_rcvpath_rtt_up == 1) &&
21140 			    (ms_cts == rack->r_ctl.last_rcv_tstmp_for_rtt)) {
21141 				/*
21142 				 * When we are doing a rcv_rtt probe all
21143 				 * other timestamps use the next msec. This
21144 				 * is safe since our previous ack is in the
21145 				 * air and we will just have a few more
21146 				 * on the next ms. This assures that only
21147 				 * the one ack has the ms_cts that was on
21148 				 * our ack-probe.
21149 				 */
21150 				ts_to_use = ms_cts + 1;
21151 			} else {
21152 				ts_to_use = ms_cts;
21153 			}
21154 			to.to_tsval = ts_to_use + tp->ts_offset;
21155 			to.to_tsecr = tp->ts_recent;
21156 			to.to_flags |= TOF_TS;
21157 			if ((len == 0) &&
21158 			    (tp->t_state == TCPS_ESTABLISHED) &&
21159 			    ((ms_cts - rack->r_ctl.last_rcv_tstmp_for_rtt) > RCV_PATH_RTT_MS) &&
21160 			    (tp->snd_una == tp->snd_max) &&
21161 			    (flags & TH_ACK) &&
21162 			    (sbavail(sb) == 0) &&
21163 			    (rack->r_ctl.current_round != 0) &&
21164 			    ((flags & (TH_SYN|TH_FIN)) == 0) &&
21165 			    (rack->r_rcvpath_rtt_up == 0)) {
21166 				rack->r_ctl.last_rcv_tstmp_for_rtt = ms_cts;
21167 				rack->r_ctl.last_time_of_arm_rcv = cts;
21168 				rack->r_rcvpath_rtt_up = 1;
21169 				/* Subtract 1 from seq to force a response */
21170 				rack_seq--;
21171 			}
21172 		}
21173 		/* Set receive buffer autosizing timestamp. */
21174 		if (tp->rfbuf_ts == 0 &&
21175 		    (so->so_rcv.sb_flags & SB_AUTOSIZE)) {
21176 			tp->rfbuf_ts = ms_cts;
21177 		}
21178 		/* Selective ACK's. */
21179 		if (tp->t_flags & TF_SACK_PERMIT) {
21180 			if (flags & TH_SYN)
21181 				to.to_flags |= TOF_SACKPERM;
21182 			else if (TCPS_HAVEESTABLISHED(tp->t_state) &&
21183 				 tp->rcv_numsacks > 0) {
21184 				to.to_flags |= TOF_SACK;
21185 				to.to_nsacks = tp->rcv_numsacks;
21186 				to.to_sacks = (u_char *)tp->sackblks;
21187 			}
21188 		}
21189 #if defined(IPSEC_SUPPORT) || defined(TCP_SIGNATURE)
21190 		/* TCP-MD5 (RFC2385). */
21191 		if (tp->t_flags & TF_SIGNATURE)
21192 			to.to_flags |= TOF_SIGNATURE;
21193 #endif
21194 
21195 		/* Processing the options. */
21196 		hdrlen += optlen = tcp_addoptions(&to, opt);
21197 		/*
21198 		 * If we wanted a TFO option to be added, but it was unable
21199 		 * to fit, ensure no data is sent.
21200 		 */
21201 		if ((tp->t_flags & TF_FASTOPEN) && wanted_cookie &&
21202 		    !(to.to_flags & TOF_FASTOPEN))
21203 			len = 0;
21204 	}
21205 	if (tp->t_port) {
21206 		if (V_tcp_udp_tunneling_port == 0) {
21207 			/* The port was removed?? */
21208 			SOCK_SENDBUF_UNLOCK(so);
21209 #ifdef TCP_ACCOUNTING
21210 			crtsc = get_cyclecount();
21211 			if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
21212 				tp->tcp_cnt_counters[SND_OUT_FAIL]++;
21213 				tp->tcp_proc_time[SND_OUT_FAIL] += (crtsc - ts_val);
21214 			}
21215 			sched_unpin();
21216 #endif
21217 			return (EHOSTUNREACH);
21218 		}
21219 		hdrlen += sizeof(struct udphdr);
21220 	}
21221 #ifdef INET6
21222 	if (isipv6)
21223 		ipoptlen = ip6_optlen(inp);
21224 	else
21225 #endif
21226 		if (inp->inp_options)
21227 			ipoptlen = inp->inp_options->m_len -
21228 				offsetof(struct ipoption, ipopt_list);
21229 		else
21230 			ipoptlen = 0;
21231 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
21232 	ipoptlen += ipsec_optlen;
21233 #endif
21234 
21235 	/*
21236 	 * Adjust data length if insertion of options will bump the packet
21237 	 * length beyond the t_maxseg length. Clear the FIN bit because we
21238 	 * cut off the tail of the segment.
21239 	 */
21240 	if (len + optlen + ipoptlen > tp->t_maxseg) {
21241 		if (tso) {
21242 			uint32_t if_hw_tsomax;
21243 			uint32_t moff;
21244 			int32_t max_len;
21245 
21246 			/* extract TSO information */
21247 			if_hw_tsomax = tp->t_tsomax;
21248 			if_hw_tsomaxsegcount = tp->t_tsomaxsegcount;
21249 			if_hw_tsomaxsegsize = tp->t_tsomaxsegsize;
21250 			KASSERT(ipoptlen == 0,
21251 				("%s: TSO can't do IP options", __func__));
21252 
21253 			/*
21254 			 * Check if we should limit by maximum payload
21255 			 * length:
21256 			 */
21257 			if (if_hw_tsomax != 0) {
21258 				/* compute maximum TSO length */
21259 				max_len = (if_hw_tsomax - hdrlen -
21260 					   max_linkhdr);
21261 				if (max_len <= 0) {
21262 					len = 0;
21263 				} else if (len > max_len) {
21264 					if (doing_tlp == 0)
21265 						sendalot = 1;
21266 					len = max_len;
21267 					mark = 2;
21268 				}
21269 			}
21270 			/*
21271 			 * Prevent the last segment from being fractional
21272 			 * unless the send sockbuf can be emptied:
21273 			 */
21274 			max_len = (tp->t_maxseg - optlen);
21275 			if ((sb_offset + len) < sbavail(sb)) {
21276 				moff = len % (u_int)max_len;
21277 				if (moff != 0) {
21278 					mark = 3;
21279 					len -= moff;
21280 				}
21281 			}
21282 			/*
21283 			 * In case there are too many small fragments don't
21284 			 * use TSO:
21285 			 */
21286 			if (len <= max_len) {
21287 				mark = 4;
21288 				tso = 0;
21289 			}
21290 			/*
21291 			 * Send the FIN in a separate segment after the bulk
21292 			 * sending is done. We don't trust the TSO
21293 			 * implementations to clear the FIN flag on all but
21294 			 * the last segment.
21295 			 */
21296 			if (tp->t_flags & TF_NEEDFIN) {
21297 				sendalot = 4;
21298 			}
21299 		} else {
21300 			mark = 5;
21301 			if (optlen + ipoptlen >= tp->t_maxseg) {
21302 				/*
21303 				 * Since we don't have enough space to put
21304 				 * the IP header chain and the TCP header in
21305 				 * one packet as required by RFC 7112, don't
21306 				 * send it. Also ensure that at least one
21307 				 * byte of the payload can be put into the
21308 				 * TCP segment.
21309 				 */
21310 				SOCK_SENDBUF_UNLOCK(so);
21311 				error = EMSGSIZE;
21312 				sack_rxmit = 0;
21313 				goto out;
21314 			}
21315 			len = tp->t_maxseg - optlen - ipoptlen;
21316 			sendalot = 5;
21317 		}
21318 	} else {
21319 		tso = 0;
21320 		mark = 6;
21321 	}
21322 	KASSERT(len + hdrlen + ipoptlen <= IP_MAXPACKET,
21323 		("%s: len > IP_MAXPACKET", __func__));
21324 #ifdef DIAGNOSTIC
21325 #ifdef INET6
21326 	if (max_linkhdr + hdrlen > MCLBYTES)
21327 #else
21328 		if (max_linkhdr + hdrlen > MHLEN)
21329 #endif
21330 			panic("tcphdr too big");
21331 #endif
21332 
21333 	/*
21334 	 * This KASSERT is here to catch edge cases at a well defined place.
21335 	 * Before, those had triggered (random) panic conditions further
21336 	 * down.
21337 	 */
21338 	KASSERT(len >= 0, ("[%s:%d]: len < 0", __func__, __LINE__));
21339 	if ((len == 0) &&
21340 	    (flags & TH_FIN) &&
21341 	    (sbused(sb))) {
21342 		/*
21343 		 * We have outstanding data, don't send a fin by itself!.
21344 		 *
21345 		 * Check to see if we need to send a challenge ack.
21346 		 */
21347 		if ((sbused(sb) == (tp->snd_max - tp->snd_una)) &&
21348 		    ((tp->snd_max - tp->snd_una) <= segsiz)) {
21349 			/*
21350 			 * Ok less than or right at a MSS is
21351 			 * outstanding. The original FreeBSD stack would
21352 			 * have sent a FIN, which can speed things up for
21353 			 * a transactional application doing a MSG_WAITALL.
21354 			 * To speed things up since we do *not* send a FIN
21355 			 * if data is outstanding, we send a "challenge ack".
21356 			 * The idea behind that is instead of having to have
21357 			 * the peer wait for the delayed-ack timer to run off
21358 			 * we send an ack that makes the peer send us an ack.
21359 			 */
21360 			rack_send_ack_challange(rack);
21361 		}
21362 		goto just_return;
21363 	}
21364 	/*
21365 	 * Grab a header mbuf, attaching a copy of data to be transmitted,
21366 	 * and initialize the header from the template for sends on this
21367 	 * connection.
21368 	 */
21369 	hw_tls = tp->t_nic_ktls_xmit != 0;
21370 	if (len) {
21371 		uint32_t max_val;
21372 		uint32_t moff;
21373 
21374 		if (pace_max_seg)
21375 			max_val = pace_max_seg;
21376 		else
21377 			max_val = len;
21378 		/*
21379 		 * We allow a limit on sending with hptsi.
21380 		 */
21381 		if (len > max_val) {
21382 			mark = 7;
21383 			len = max_val;
21384 		}
21385 #ifdef INET6
21386 		if (MHLEN < hdrlen + max_linkhdr)
21387 			m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR);
21388 		else
21389 #endif
21390 			m = m_gethdr(M_NOWAIT, MT_DATA);
21391 
21392 		if (m == NULL) {
21393 			SOCK_SENDBUF_UNLOCK(so);
21394 			error = ENOBUFS;
21395 			sack_rxmit = 0;
21396 			goto out;
21397 		}
21398 		m->m_data += max_linkhdr;
21399 		m->m_len = hdrlen;
21400 
21401 		/*
21402 		 * Start the m_copy functions from the closest mbuf to the
21403 		 * sb_offset in the socket buffer chain.
21404 		 */
21405 		mb = sbsndptr_noadv(sb, sb_offset, &moff);
21406 		s_mb = mb;
21407 		s_moff = moff;
21408 		if (len <= MHLEN - hdrlen - max_linkhdr && !hw_tls) {
21409 			m_copydata(mb, moff, (int)len,
21410 				   mtod(m, caddr_t)+hdrlen);
21411 			/*
21412 			 * If we are not retransmitting advance the
21413 			 * sndptr to help remember the next place in
21414 			 * the sb.
21415 			 */
21416 			if (rsm == NULL)
21417 				sbsndptr_adv(sb, mb, len);
21418 			m->m_len += len;
21419 		} else {
21420 			struct sockbuf *msb;
21421 
21422 			/*
21423 			 * If we are not retransmitting pass in msb so
21424 			 * the socket buffer can be advanced. Otherwise
21425 			 * set it to NULL if its a retransmission since
21426 			 * we don't want to change the sb remembered
21427 			 * location.
21428 			 */
21429 			if (rsm == NULL)
21430 				msb = sb;
21431 			else
21432 				msb = NULL;
21433 			m->m_next = tcp_m_copym(
21434 				mb, moff, &len,
21435 				if_hw_tsomaxsegcount, if_hw_tsomaxsegsize, msb,
21436 				((rsm == NULL) ? hw_tls : 0));
21437 			if (len <= (tp->t_maxseg - optlen)) {
21438 				/*
21439 				 * Must have ran out of mbufs for the copy
21440 				 * shorten it to no longer need tso. Lets
21441 				 * not put on sendalot since we are low on
21442 				 * mbufs.
21443 				 */
21444 				tso = 0;
21445 			}
21446 			if (m->m_next == NULL) {
21447 				SOCK_SENDBUF_UNLOCK(so);
21448 				(void)m_free(m);
21449 				error = ENOBUFS;
21450 				sack_rxmit = 0;
21451 				goto out;
21452 			}
21453 		}
21454 		if (sack_rxmit) {
21455 			if (rsm && (rsm->r_flags & RACK_TLP)) {
21456 				/*
21457 				 * TLP should not count in retran count, but
21458 				 * in its own bin
21459 				 */
21460 				counter_u64_add(rack_tlp_retran, 1);
21461 				counter_u64_add(rack_tlp_retran_bytes, len);
21462 			} else {
21463 				tp->t_sndrexmitpack++;
21464 				KMOD_TCPSTAT_INC(tcps_sndrexmitpack);
21465 				KMOD_TCPSTAT_ADD(tcps_sndrexmitbyte, len);
21466 			}
21467 #ifdef STATS
21468 			stats_voi_update_abs_u32(tp->t_stats, VOI_TCP_RETXPB,
21469 						 len);
21470 #endif
21471 		} else {
21472 			KMOD_TCPSTAT_INC(tcps_sndpack);
21473 			KMOD_TCPSTAT_ADD(tcps_sndbyte, len);
21474 #ifdef STATS
21475 			stats_voi_update_abs_u64(tp->t_stats, VOI_TCP_TXPB,
21476 						 len);
21477 #endif
21478 		}
21479 		/*
21480 		 * If we're sending everything we've got, set PUSH. (This
21481 		 * will keep happy those implementations which only give
21482 		 * data to the user when a buffer fills or a PUSH comes in.)
21483 		 */
21484 		if (sb_offset + len == sbused(sb) &&
21485 		    sbused(sb) &&
21486 		    !(flags & TH_SYN)) {
21487 			flags |= TH_PUSH;
21488 			add_flag |= RACK_HAD_PUSH;
21489 		}
21490 		SOCK_SENDBUF_UNLOCK(so);
21491 	} else {
21492 		SOCK_SENDBUF_UNLOCK(so);
21493 		if (tp->t_flags & TF_ACKNOW)
21494 			KMOD_TCPSTAT_INC(tcps_sndacks);
21495 		else if (flags & (TH_SYN | TH_FIN | TH_RST))
21496 			KMOD_TCPSTAT_INC(tcps_sndctrl);
21497 		else
21498 			KMOD_TCPSTAT_INC(tcps_sndwinup);
21499 
21500 		m = m_gethdr(M_NOWAIT, MT_DATA);
21501 		if (m == NULL) {
21502 			error = ENOBUFS;
21503 			sack_rxmit = 0;
21504 			goto out;
21505 		}
21506 #ifdef INET6
21507 		if (isipv6 && (MHLEN < hdrlen + max_linkhdr) &&
21508 		    MHLEN >= hdrlen) {
21509 			M_ALIGN(m, hdrlen);
21510 		} else
21511 #endif
21512 			m->m_data += max_linkhdr;
21513 		m->m_len = hdrlen;
21514 	}
21515 	SOCK_SENDBUF_UNLOCK_ASSERT(so);
21516 	m->m_pkthdr.rcvif = (struct ifnet *)0;
21517 #ifdef MAC
21518 	mac_inpcb_create_mbuf(inp, m);
21519 #endif
21520 	if ((ipoptlen == 0) && (rack->r_ctl.fsb.tcp_ip_hdr) &&  rack->r_fsb_inited) {
21521 #ifdef INET6
21522 		if (isipv6)
21523 			ip6 = (struct ip6_hdr *)rack->r_ctl.fsb.tcp_ip_hdr;
21524 		else
21525 #endif				/* INET6 */
21526 #ifdef INET
21527 			ip = (struct ip *)rack->r_ctl.fsb.tcp_ip_hdr;
21528 #endif
21529 		th = rack->r_ctl.fsb.th;
21530 		udp = rack->r_ctl.fsb.udp;
21531 		if (udp) {
21532 #ifdef INET6
21533 			if (isipv6)
21534 				ulen = hdrlen + len - sizeof(struct ip6_hdr);
21535 			else
21536 #endif				/* INET6 */
21537 				ulen = hdrlen + len - sizeof(struct ip);
21538 			udp->uh_ulen = htons(ulen);
21539 		}
21540 	} else {
21541 #ifdef INET6
21542 		if (isipv6) {
21543 			ip6 = mtod(m, struct ip6_hdr *);
21544 			if (tp->t_port) {
21545 				udp = (struct udphdr *)((caddr_t)ip6 + sizeof(struct ip6_hdr));
21546 				udp->uh_sport = htons(V_tcp_udp_tunneling_port);
21547 				udp->uh_dport = tp->t_port;
21548 				ulen = hdrlen + len - sizeof(struct ip6_hdr);
21549 				udp->uh_ulen = htons(ulen);
21550 				th = (struct tcphdr *)(udp + 1);
21551 			} else
21552 				th = (struct tcphdr *)(ip6 + 1);
21553 			tcpip_fillheaders(inp, tp->t_port, ip6, th);
21554 		} else
21555 #endif				/* INET6 */
21556 		{
21557 #ifdef INET
21558 			ip = mtod(m, struct ip *);
21559 			if (tp->t_port) {
21560 				udp = (struct udphdr *)((caddr_t)ip + sizeof(struct ip));
21561 				udp->uh_sport = htons(V_tcp_udp_tunneling_port);
21562 				udp->uh_dport = tp->t_port;
21563 				ulen = hdrlen + len - sizeof(struct ip);
21564 				udp->uh_ulen = htons(ulen);
21565 				th = (struct tcphdr *)(udp + 1);
21566 			} else
21567 				th = (struct tcphdr *)(ip + 1);
21568 			tcpip_fillheaders(inp, tp->t_port, ip, th);
21569 #endif
21570 		}
21571 	}
21572 	/*
21573 	 * If we are starting a connection, send ECN setup SYN packet. If we
21574 	 * are on a retransmit, we may resend those bits a number of times
21575 	 * as per RFC 3168.
21576 	 */
21577 	if (tp->t_state == TCPS_SYN_SENT && V_tcp_do_ecn) {
21578 		flags |= tcp_ecn_output_syn_sent(tp);
21579 	}
21580 	/* Also handle parallel SYN for ECN */
21581 	if (TCPS_HAVERCVDSYN(tp->t_state) &&
21582 	    (tp->t_flags2 & (TF2_ECN_PERMIT | TF2_ACE_PERMIT))) {
21583 		int ect = tcp_ecn_output_established(tp, &flags, len, sack_rxmit);
21584 		if ((tp->t_state == TCPS_SYN_RECEIVED) &&
21585 		    (tp->t_flags2 & TF2_ECN_SND_ECE))
21586 			tp->t_flags2 &= ~TF2_ECN_SND_ECE;
21587 #ifdef INET6
21588 		if (isipv6) {
21589 			ip6->ip6_flow &= ~htonl(IPTOS_ECN_MASK << 20);
21590 			ip6->ip6_flow |= htonl(ect << 20);
21591 		}
21592 		else
21593 #endif
21594 		{
21595 #ifdef INET
21596 			ip->ip_tos &= ~IPTOS_ECN_MASK;
21597 			ip->ip_tos |= ect;
21598 #endif
21599 		}
21600 	}
21601 	th->th_seq = htonl(rack_seq);
21602 	th->th_ack = htonl(tp->rcv_nxt);
21603 	tcp_set_flags(th, flags);
21604 	/*
21605 	 * Calculate receive window.  Don't shrink window, but avoid silly
21606 	 * window syndrome.
21607 	 * If a RST segment is sent, advertise a window of zero.
21608 	 */
21609 	if (flags & TH_RST) {
21610 		recwin = 0;
21611 	} else {
21612 		if (recwin < (long)(so->so_rcv.sb_hiwat / 4) &&
21613 		    recwin < (long)segsiz) {
21614 			recwin = 0;
21615 		}
21616 		if (SEQ_GT(tp->rcv_adv, tp->rcv_nxt) &&
21617 		    recwin < (long)(tp->rcv_adv - tp->rcv_nxt))
21618 			recwin = (long)(tp->rcv_adv - tp->rcv_nxt);
21619 	}
21620 
21621 	/*
21622 	 * According to RFC1323 the window field in a SYN (i.e., a <SYN> or
21623 	 * <SYN,ACK>) segment itself is never scaled.  The <SYN,ACK> case is
21624 	 * handled in syncache.
21625 	 */
21626 	if (flags & TH_SYN)
21627 		th->th_win = htons((u_short)
21628 				   (min(sbspace(&so->so_rcv), TCP_MAXWIN)));
21629 	else {
21630 		/* Avoid shrinking window with window scaling. */
21631 		recwin = roundup2(recwin, 1 << tp->rcv_scale);
21632 		th->th_win = htons((u_short)(recwin >> tp->rcv_scale));
21633 	}
21634 	/*
21635 	 * Adjust the RXWIN0SENT flag - indicate that we have advertised a 0
21636 	 * window.  This may cause the remote transmitter to stall.  This
21637 	 * flag tells soreceive() to disable delayed acknowledgements when
21638 	 * draining the buffer.  This can occur if the receiver is
21639 	 * attempting to read more data than can be buffered prior to
21640 	 * transmitting on the connection.
21641 	 */
21642 	if (th->th_win == 0) {
21643 		tp->t_sndzerowin++;
21644 		tp->t_flags |= TF_RXWIN0SENT;
21645 	} else
21646 		tp->t_flags &= ~TF_RXWIN0SENT;
21647 	tp->snd_up = tp->snd_una;	/* drag it along, its deprecated */
21648 	/* Now are we using fsb?, if so copy the template data to the mbuf */
21649 	if ((ipoptlen == 0) && (rack->r_ctl.fsb.tcp_ip_hdr) && rack->r_fsb_inited) {
21650 		uint8_t *cpto;
21651 
21652 		cpto = mtod(m, uint8_t *);
21653 		memcpy(cpto, rack->r_ctl.fsb.tcp_ip_hdr, rack->r_ctl.fsb.tcp_ip_hdr_len);
21654 		/*
21655 		 * We have just copied in:
21656 		 * IP/IP6
21657 		 * <optional udphdr>
21658 		 * tcphdr (no options)
21659 		 *
21660 		 * We need to grab the correct pointers into the mbuf
21661 		 * for both the tcp header, and possibly the udp header (if tunneling).
21662 		 * We do this by using the offset in the copy buffer and adding it
21663 		 * to the mbuf base pointer (cpto).
21664 		 */
21665 #ifdef INET6
21666 		if (isipv6)
21667 			ip6 = mtod(m, struct ip6_hdr *);
21668 		else
21669 #endif				/* INET6 */
21670 #ifdef INET
21671 			ip = mtod(m, struct ip *);
21672 #endif
21673 		th = (struct tcphdr *)(cpto + ((uint8_t *)rack->r_ctl.fsb.th - rack->r_ctl.fsb.tcp_ip_hdr));
21674 		/* If we have a udp header lets set it into the mbuf as well */
21675 		if (udp)
21676 			udp = (struct udphdr *)(cpto + ((uint8_t *)rack->r_ctl.fsb.udp - rack->r_ctl.fsb.tcp_ip_hdr));
21677 	}
21678 	if (optlen) {
21679 		bcopy(opt, th + 1, optlen);
21680 		th->th_off = (sizeof(struct tcphdr) + optlen) >> 2;
21681 	}
21682 	/*
21683 	 * Put TCP length in extended header, and then checksum extended
21684 	 * header and data.
21685 	 */
21686 	m->m_pkthdr.len = hdrlen + len;	/* in6_cksum() need this */
21687 #if defined(IPSEC_SUPPORT) || defined(TCP_SIGNATURE)
21688 	if (to.to_flags & TOF_SIGNATURE) {
21689 		/*
21690 		 * Calculate MD5 signature and put it into the place
21691 		 * determined before.
21692 		 * NOTE: since TCP options buffer doesn't point into
21693 		 * mbuf's data, calculate offset and use it.
21694 		 */
21695 		if (!TCPMD5_ENABLED() || TCPMD5_OUTPUT(m, th,
21696 						       (u_char *)(th + 1) + (to.to_signature - opt)) != 0) {
21697 			/*
21698 			 * Do not send segment if the calculation of MD5
21699 			 * digest has failed.
21700 			 */
21701 			goto out;
21702 		}
21703 	}
21704 #endif
21705 #ifdef INET6
21706 	if (isipv6) {
21707 		/*
21708 		 * ip6_plen is not need to be filled now, and will be filled
21709 		 * in ip6_output.
21710 		 */
21711 		if (tp->t_port) {
21712 			m->m_pkthdr.csum_flags = CSUM_UDP_IPV6;
21713 			m->m_pkthdr.csum_data = offsetof(struct udphdr, uh_sum);
21714 			udp->uh_sum = in6_cksum_pseudo(ip6, ulen, IPPROTO_UDP, 0);
21715 			th->th_sum = htons(0);
21716 			UDPSTAT_INC(udps_opackets);
21717 		} else {
21718 			m->m_pkthdr.csum_flags = CSUM_TCP_IPV6;
21719 			m->m_pkthdr.csum_data = offsetof(struct tcphdr, th_sum);
21720 			th->th_sum = in6_cksum_pseudo(ip6,
21721 						      sizeof(struct tcphdr) + optlen + len, IPPROTO_TCP,
21722 						      0);
21723 		}
21724 	}
21725 #endif
21726 #if defined(INET6) && defined(INET)
21727 	else
21728 #endif
21729 #ifdef INET
21730 	{
21731 		if (tp->t_port) {
21732 			m->m_pkthdr.csum_flags = CSUM_UDP;
21733 			m->m_pkthdr.csum_data = offsetof(struct udphdr, uh_sum);
21734 			udp->uh_sum = in_pseudo(ip->ip_src.s_addr,
21735 						ip->ip_dst.s_addr, htons(ulen + IPPROTO_UDP));
21736 			th->th_sum = htons(0);
21737 			UDPSTAT_INC(udps_opackets);
21738 		} else {
21739 			m->m_pkthdr.csum_flags = CSUM_TCP;
21740 			m->m_pkthdr.csum_data = offsetof(struct tcphdr, th_sum);
21741 			th->th_sum = in_pseudo(ip->ip_src.s_addr,
21742 					       ip->ip_dst.s_addr, htons(sizeof(struct tcphdr) +
21743 									IPPROTO_TCP + len + optlen));
21744 		}
21745 		/* IP version must be set here for ipv4/ipv6 checking later */
21746 		KASSERT(ip->ip_v == IPVERSION,
21747 			("%s: IP version incorrect: %d", __func__, ip->ip_v));
21748 	}
21749 #endif
21750 	/*
21751 	 * Enable TSO and specify the size of the segments. The TCP pseudo
21752 	 * header checksum is always provided. XXX: Fixme: This is currently
21753 	 * not the case for IPv6.
21754 	 */
21755 	if (tso) {
21756 		/*
21757 		 * Here we must use t_maxseg and the optlen since
21758 		 * the optlen may include SACK's (or DSACK).
21759 		 */
21760 		KASSERT(len > tp->t_maxseg - optlen,
21761 			("%s: len <= tso_segsz", __func__));
21762 		m->m_pkthdr.csum_flags |= CSUM_TSO;
21763 		m->m_pkthdr.tso_segsz = tp->t_maxseg - optlen;
21764 	}
21765 	KASSERT(len + hdrlen == m_length(m, NULL),
21766 		("%s: mbuf chain different than expected: %d + %u != %u",
21767 		 __func__, len, hdrlen, m_length(m, NULL)));
21768 
21769 #ifdef TCP_HHOOK
21770 	/* Run HHOOK_TCP_ESTABLISHED_OUT helper hooks. */
21771 	hhook_run_tcp_est_out(tp, th, &to, len, tso);
21772 #endif
21773 	if ((rack->r_ctl.crte != NULL) &&
21774 	    (rack->rc_hw_nobuf == 0) &&
21775 	    tcp_bblogging_on(tp)) {
21776 		rack_log_queue_level(tp, rack, len, &tv, cts);
21777 	}
21778 	/* We're getting ready to send; log now. */
21779 	if (tcp_bblogging_on(rack->rc_tp)) {
21780 		union tcp_log_stackspecific log;
21781 
21782 		memset(&log, 0, sizeof(log));
21783 		log.u_bbr.inhpts = tcp_in_hpts(rack->rc_tp);
21784 		if (rack->rack_no_prr)
21785 			log.u_bbr.flex1 = 0;
21786 		else
21787 			log.u_bbr.flex1 = rack->r_ctl.rc_prr_sndcnt;
21788 		log.u_bbr.flex2 = rack->r_ctl.rc_pace_min_segs;
21789 		log.u_bbr.flex3 = rack->r_ctl.rc_pace_max_segs;
21790 		log.u_bbr.flex4 = orig_len;
21791 		/* Save off the early/late values */
21792 		log.u_bbr.flex6 = rack->r_ctl.rc_agg_early;
21793 		log.u_bbr.applimited = rack->r_ctl.rc_agg_delayed;
21794 		log.u_bbr.bw_inuse = rack_get_bw(rack);
21795 		log.u_bbr.cur_del_rate = rack->r_ctl.gp_bw;
21796 		log.u_bbr.flex8 = 0;
21797 		if (rsm) {
21798 			if (rsm->r_flags & RACK_RWND_COLLAPSED) {
21799 				rack_log_collapse(rack, rsm->r_start, rsm->r_end, 0, __LINE__, 5, rsm->r_flags, rsm);
21800 				counter_u64_add(rack_collapsed_win_rxt, 1);
21801 				counter_u64_add(rack_collapsed_win_rxt_bytes, (rsm->r_end - rsm->r_start));
21802 			}
21803 			if (doing_tlp)
21804 				log.u_bbr.flex8 = 2;
21805 			else
21806 				log.u_bbr.flex8 = 1;
21807 		} else {
21808 			if (doing_tlp)
21809 				log.u_bbr.flex8 = 3;
21810 		}
21811 		log.u_bbr.pacing_gain = rack_get_output_gain(rack, rsm);
21812 		log.u_bbr.flex7 = mark;
21813 		log.u_bbr.flex7 <<= 8;
21814 		log.u_bbr.flex7 |= pass;
21815 		log.u_bbr.pkts_out = tp->t_maxseg;
21816 		log.u_bbr.timeStamp = cts;
21817 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
21818 		if (rsm && (rsm->r_rtr_cnt > 0)) {
21819 			/*
21820 			 * When we have a retransmit we want to log the
21821 			 * burst at send and flight at send from before.
21822 			 */
21823 			log.u_bbr.flex5 = rsm->r_fas;
21824 			log.u_bbr.bbr_substate = rsm->r_bas;
21825 		} else {
21826 			/*
21827 			 * New transmits we log in flex5 the inflight again as
21828 			 * well as the number of segments in our send in the
21829 			 * substate field.
21830 			 */
21831 			log.u_bbr.flex5 = log.u_bbr.inflight;
21832 			log.u_bbr.bbr_substate = (uint8_t)((len + segsiz - 1)/segsiz);
21833 		}
21834 		log.u_bbr.lt_epoch = cwnd_to_use;
21835 		log.u_bbr.delivered = sendalot;
21836 		log.u_bbr.rttProp = (uintptr_t)rsm;
21837 		log.u_bbr.pkt_epoch = __LINE__;
21838 		if (rsm) {
21839 			log.u_bbr.delRate = rsm->r_flags;
21840 			log.u_bbr.delRate <<= 31;
21841 			log.u_bbr.delRate |= rack->r_must_retran;
21842 			log.u_bbr.delRate <<= 1;
21843 			log.u_bbr.delRate |= (sack_rxmit & 0x00000001);
21844 		} else {
21845 			log.u_bbr.delRate = rack->r_must_retran;
21846 			log.u_bbr.delRate <<= 1;
21847 			log.u_bbr.delRate |= (sack_rxmit & 0x00000001);
21848 		}
21849 		lgb = tcp_log_event(tp, th, &so->so_rcv, &so->so_snd, TCP_LOG_OUT, ERRNO_UNK,
21850 				    len, &log, false, NULL, __func__, __LINE__, &tv);
21851 	} else
21852 		lgb = NULL;
21853 
21854 	/*
21855 	 * Fill in IP length and desired time to live and send to IP level.
21856 	 * There should be a better way to handle ttl and tos; we could keep
21857 	 * them in the template, but need a way to checksum without them.
21858 	 */
21859 	/*
21860 	 * m->m_pkthdr.len should have been set before cksum calcuration,
21861 	 * because in6_cksum() need it.
21862 	 */
21863 #ifdef INET6
21864 	if (isipv6) {
21865 		/*
21866 		 * we separately set hoplimit for every segment, since the
21867 		 * user might want to change the value via setsockopt. Also,
21868 		 * desired default hop limit might be changed via Neighbor
21869 		 * Discovery.
21870 		 */
21871 		rack->r_ctl.fsb.hoplimit = ip6->ip6_hlim = in6_selecthlim(inp, NULL);
21872 
21873 		/*
21874 		 * Set the packet size here for the benefit of DTrace
21875 		 * probes. ip6_output() will set it properly; it's supposed
21876 		 * to include the option header lengths as well.
21877 		 */
21878 		ip6->ip6_plen = htons(m->m_pkthdr.len - sizeof(*ip6));
21879 
21880 		if (V_path_mtu_discovery && tp->t_maxseg > V_tcp_minmss)
21881 			tp->t_flags2 |= TF2_PLPMTU_PMTUD;
21882 		else
21883 			tp->t_flags2 &= ~TF2_PLPMTU_PMTUD;
21884 
21885 		if (tp->t_state == TCPS_SYN_SENT)
21886 			TCP_PROBE5(connect__request, NULL, tp, ip6, tp, th);
21887 
21888 		TCP_PROBE5(send, NULL, tp, ip6, tp, th);
21889 		/* TODO: IPv6 IP6TOS_ECT bit on */
21890 		error = ip6_output(m,
21891 				   inp->in6p_outputopts,
21892 				   &inp->inp_route6,
21893 				   ((rsm || sack_rxmit) ? IP_NO_SND_TAG_RL : 0),
21894 				   NULL, NULL, inp);
21895 
21896 		if (error == EMSGSIZE && inp->inp_route6.ro_nh != NULL)
21897 			mtu = inp->inp_route6.ro_nh->nh_mtu;
21898 	}
21899 #endif				/* INET6 */
21900 #if defined(INET) && defined(INET6)
21901 	else
21902 #endif
21903 #ifdef INET
21904 	{
21905 		ip->ip_len = htons(m->m_pkthdr.len);
21906 #ifdef INET6
21907 		if (inp->inp_vflag & INP_IPV6PROTO)
21908 			ip->ip_ttl = in6_selecthlim(inp, NULL);
21909 #endif				/* INET6 */
21910 		rack->r_ctl.fsb.hoplimit = ip->ip_ttl;
21911 		/*
21912 		 * If we do path MTU discovery, then we set DF on every
21913 		 * packet. This might not be the best thing to do according
21914 		 * to RFC3390 Section 2. However the tcp hostcache migitates
21915 		 * the problem so it affects only the first tcp connection
21916 		 * with a host.
21917 		 *
21918 		 * NB: Don't set DF on small MTU/MSS to have a safe
21919 		 * fallback.
21920 		 */
21921 		if (V_path_mtu_discovery && tp->t_maxseg > V_tcp_minmss) {
21922 			tp->t_flags2 |= TF2_PLPMTU_PMTUD;
21923 			if (tp->t_port == 0 || len < V_tcp_minmss) {
21924 				ip->ip_off |= htons(IP_DF);
21925 			}
21926 		} else {
21927 			tp->t_flags2 &= ~TF2_PLPMTU_PMTUD;
21928 		}
21929 
21930 		if (tp->t_state == TCPS_SYN_SENT)
21931 			TCP_PROBE5(connect__request, NULL, tp, ip, tp, th);
21932 
21933 		TCP_PROBE5(send, NULL, tp, ip, tp, th);
21934 
21935 		error = ip_output(m,
21936 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
21937 				  inp->inp_options,
21938 #else
21939 				  NULL,
21940 #endif
21941 				  &inp->inp_route,
21942 				  ((rsm || sack_rxmit) ? IP_NO_SND_TAG_RL : 0), 0,
21943 				  inp);
21944 		if (error == EMSGSIZE && inp->inp_route.ro_nh != NULL)
21945 			mtu = inp->inp_route.ro_nh->nh_mtu;
21946 	}
21947 #endif				/* INET */
21948 	if (lgb) {
21949 		lgb->tlb_errno = error;
21950 		lgb = NULL;
21951 	}
21952 
21953 out:
21954 	/*
21955 	 * In transmit state, time the transmission and arrange for the
21956 	 * retransmit.  In persist state, just set snd_max.
21957 	 */
21958 	if ((rsm == NULL) &&  doing_tlp)
21959 		add_flag |= RACK_TLP;
21960 	rack_log_output(tp, &to, len, rack_seq, (uint8_t) flags, error,
21961 			rack_to_usec_ts(&tv),
21962 			rsm, add_flag, s_mb, s_moff, hw_tls, segsiz);
21963 	if (error == 0) {
21964 		if (add_flag & RACK_IS_PCM) {
21965 			/* We just launched a PCM */
21966 			/* rrs here log */
21967 			rack->pcm_in_progress = 1;
21968 			rack->pcm_needed = 0;
21969 			rack_log_pcm(rack, 7, len, rack->r_ctl.pcm_max_seg,  add_flag);
21970 		}
21971 		if (rsm == NULL) {
21972 			if (rack->lt_bw_up == 0) {
21973 				rack->r_ctl.lt_timemark = tcp_tv_to_lusec(&tv);
21974 				rack->r_ctl.lt_seq = tp->snd_una;
21975 				rack->lt_bw_up = 1;
21976 			} else if (((rack_seq + len) - rack->r_ctl.lt_seq) > 0x7fffffff) {
21977 				/*
21978 				 * Need to record what we have since we are
21979 				 * approaching seq wrap.
21980 				 */
21981 				uint64_t tmark;
21982 
21983 				rack->r_ctl.lt_bw_bytes += (tp->snd_una - rack->r_ctl.lt_seq);
21984 				rack->r_ctl.lt_seq = tp->snd_una;
21985 				tmark = tcp_get_u64_usecs(&tv);
21986 				if (tmark > rack->r_ctl.lt_timemark) {
21987 					rack->r_ctl.lt_bw_time += (tmark - rack->r_ctl.lt_timemark);
21988 					rack->r_ctl.lt_timemark = tmark;
21989 				}
21990 			}
21991 		}
21992 		rack->forced_ack = 0;	/* If we send something zap the FA flag */
21993 		counter_u64_add(rack_total_bytes, len);
21994 		tcp_account_for_send(tp, len, (rsm != NULL), doing_tlp, hw_tls);
21995 		if (rsm && doing_tlp) {
21996 			rack->rc_last_sent_tlp_past_cumack = 0;
21997 			rack->rc_last_sent_tlp_seq_valid = 1;
21998 			rack->r_ctl.last_sent_tlp_seq = rsm->r_start;
21999 			rack->r_ctl.last_sent_tlp_len = rsm->r_end - rsm->r_start;
22000 		}
22001 		if (rack->rc_hw_nobuf) {
22002 			rack->rc_hw_nobuf = 0;
22003 			rack->r_ctl.rc_agg_delayed = 0;
22004 			rack->r_early = 0;
22005 			rack->r_late = 0;
22006 			rack->r_ctl.rc_agg_early = 0;
22007 		}
22008 		if (rsm && (doing_tlp == 0)) {
22009 			/* Set we retransmitted */
22010 			rack->rc_gp_saw_rec = 1;
22011 		} else {
22012 			if (cwnd_to_use > tp->snd_ssthresh) {
22013 				/* Set we sent in CA */
22014 				rack->rc_gp_saw_ca = 1;
22015 			} else {
22016 				/* Set we sent in SS */
22017 				rack->rc_gp_saw_ss = 1;
22018 			}
22019 		}
22020 		if (TCPS_HAVEESTABLISHED(tp->t_state) &&
22021 		    (tp->t_flags & TF_SACK_PERMIT) &&
22022 		    tp->rcv_numsacks > 0)
22023 			tcp_clean_dsack_blocks(tp);
22024 		tot_len_this_send += len;
22025 		if (len == 0) {
22026 			counter_u64_add(rack_out_size[TCP_MSS_ACCT_SNDACK], 1);
22027 		} else {
22028 			int idx;
22029 
22030 			idx = (len / segsiz) + 3;
22031 			if (idx >= TCP_MSS_ACCT_ATIMER)
22032 				counter_u64_add(rack_out_size[(TCP_MSS_ACCT_ATIMER-1)], 1);
22033 			else
22034 				counter_u64_add(rack_out_size[idx], 1);
22035 		}
22036 	}
22037 	if ((rack->rack_no_prr == 0) &&
22038 	    sub_from_prr &&
22039 	    (error == 0)) {
22040 		if (rack->r_ctl.rc_prr_sndcnt >= len)
22041 			rack->r_ctl.rc_prr_sndcnt -= len;
22042 		else
22043 			rack->r_ctl.rc_prr_sndcnt = 0;
22044 	}
22045 	sub_from_prr = 0;
22046 	if (rsm != NULL) {
22047 		if (doing_tlp)
22048 			/* Make sure the TLP is added */
22049 			rsm->r_flags |= RACK_TLP;
22050 		else
22051 			/* If its a resend without TLP then it must not have the flag */
22052 			rsm->r_flags &= ~RACK_TLP;
22053  	}
22054 	if ((error == 0) &&
22055 	    (len > 0) &&
22056 	    (tp->snd_una == tp->snd_max))
22057 		rack->r_ctl.rc_tlp_rxt_last_time = cts;
22058 
22059 	{
22060 		/*
22061 		 * This block is not associated with the above error == 0 test.
22062 		 * It is used to advance snd_max if we have a new transmit.
22063 		 */
22064 		tcp_seq startseq = tp->snd_max;
22065 
22066 
22067 		if (rsm && (doing_tlp == 0))
22068 			rack->r_ctl.rc_loss_count += rsm->r_end - rsm->r_start;
22069 		if (error)
22070 			/* We don't log or do anything with errors */
22071 			goto nomore;
22072 		if (doing_tlp == 0) {
22073 			if (rsm == NULL) {
22074 				/*
22075 				 * Not a retransmission of some
22076 				 * sort, new data is going out so
22077 				 * clear our TLP count and flag.
22078 				 */
22079 				rack->rc_tlp_in_progress = 0;
22080 				rack->r_ctl.rc_tlp_cnt_out = 0;
22081 			}
22082 		} else {
22083 			/*
22084 			 * We have just sent a TLP, mark that it is true
22085 			 * and make sure our in progress is set so we
22086 			 * continue to check the count.
22087 			 */
22088 			rack->rc_tlp_in_progress = 1;
22089 			rack->r_ctl.rc_tlp_cnt_out++;
22090 		}
22091 		/*
22092 		 * If we are retransmitting we are done, snd_max
22093 		 * does not get updated.
22094 		 */
22095 		if (sack_rxmit)
22096 			goto nomore;
22097 		if ((tp->snd_una == tp->snd_max) && (len > 0)) {
22098 			/*
22099 			 * Update the time we just added data since
22100 			 * nothing was outstanding.
22101 			 */
22102 			rack_log_progress_event(rack, tp, ticks, PROGRESS_START, __LINE__);
22103 			tp->t_acktime = ticks;
22104 		}
22105 		/*
22106 		 * Now for special SYN/FIN handling.
22107 		 */
22108 		if (flags & (TH_SYN | TH_FIN)) {
22109 			if ((flags & TH_SYN) != 0 && tp->snd_max == tp->iss) {
22110 				tp->snd_max++;
22111 			}
22112 			if ((flags & TH_FIN) &&
22113 			    ((tp->t_flags & TF_SENTFIN) == 0)) {
22114 				tp->snd_max++;
22115 				tp->t_flags |= TF_SENTFIN;
22116 			}
22117 		}
22118 		tp->snd_max += len;
22119 		if (rack->rc_new_rnd_needed) {
22120 			rack_new_round_starts(tp, rack, tp->snd_max);
22121 		}
22122 		/*
22123 		 * Time this transmission if not a retransmission and
22124 		 * not currently timing anything.
22125 		 * This is only relevant in case of switching back to
22126 		 * the base stack.
22127 		 */
22128 		if (tp->t_rtttime == 0) {
22129 			tp->t_rtttime = ticks;
22130 			tp->t_rtseq = startseq;
22131 			KMOD_TCPSTAT_INC(tcps_segstimed);
22132 		}
22133 		if (len &&
22134 		    ((tp->t_flags & TF_GPUTINPROG) == 0))
22135 			rack_start_gp_measurement(tp, rack, startseq, sb_offset);
22136 		/*
22137 		 * If we are doing FO we need to update the mbuf position and subtract
22138 		 * this happens when the peer sends us duplicate information and
22139 		 * we thus want to send a DSACK.
22140 		 *
22141 		 * XXXRRS: This brings to mind a ?, when we send a DSACK block is TSO
22142 		 * turned off? If not then we are going to echo multiple DSACK blocks
22143 		 * out (with the TSO), which we should not be doing.
22144 		 */
22145 		if (rack->r_fast_output && len) {
22146 			if (rack->r_ctl.fsb.left_to_send > len)
22147 				rack->r_ctl.fsb.left_to_send -= len;
22148 			else
22149 				rack->r_ctl.fsb.left_to_send = 0;
22150 			if (rack->r_ctl.fsb.left_to_send < segsiz)
22151 				rack->r_fast_output = 0;
22152 			if (rack->r_fast_output) {
22153 				rack->r_ctl.fsb.m = sbsndmbuf(sb, (tp->snd_max - tp->snd_una), &rack->r_ctl.fsb.off);
22154 				rack->r_ctl.fsb.o_m_len = rack->r_ctl.fsb.m->m_len;
22155 				rack->r_ctl.fsb.o_t_len = M_TRAILINGROOM(rack->r_ctl.fsb.m);
22156 			}
22157 		}
22158 		if (rack_pcm_blast == 0) {
22159 			if ((orig_len > len) &&
22160 			    (add_flag & RACK_IS_PCM) &&
22161 			    (len < pace_max_seg) &&
22162 			    ((pace_max_seg - len) > segsiz)) {
22163 				/*
22164 				 * We are doing a PCM measurement and we did
22165 				 * not get enough data in the TSO to meet the
22166 				 * burst requirement.
22167 				 */
22168 				uint32_t n_len;
22169 
22170 				n_len = (orig_len - len);
22171 				orig_len -= len;
22172 				pace_max_seg -= len;
22173 				len = n_len;
22174 				sb_offset = tp->snd_max - tp->snd_una;
22175 				/* Re-lock for the next spin */
22176 				SOCK_SENDBUF_LOCK(so);
22177 				goto send;
22178 			}
22179 		} else {
22180 			if ((orig_len > len) &&
22181 			    (add_flag & RACK_IS_PCM) &&
22182 			    ((orig_len - len) > segsiz)) {
22183 				/*
22184 				 * We are doing a PCM measurement and we did
22185 				 * not get enough data in the TSO to meet the
22186 				 * burst requirement.
22187 				 */
22188 				uint32_t n_len;
22189 
22190 				n_len = (orig_len - len);
22191 				orig_len -= len;
22192 				len = n_len;
22193 				sb_offset = tp->snd_max - tp->snd_una;
22194 				/* Re-lock for the next spin */
22195 				SOCK_SENDBUF_LOCK(so);
22196 				goto send;
22197 			}
22198 		}
22199 	}
22200 nomore:
22201 	if (error) {
22202 		rack->r_ctl.rc_agg_delayed = 0;
22203 		rack->r_early = 0;
22204 		rack->r_late = 0;
22205 		rack->r_ctl.rc_agg_early = 0;
22206 		SOCKBUF_UNLOCK_ASSERT(sb);	/* Check gotos. */
22207 		/*
22208 		 * Failures do not advance the seq counter above. For the
22209 		 * case of ENOBUFS we will fall out and retry in 1ms with
22210 		 * the hpts. Everything else will just have to retransmit
22211 		 * with the timer.
22212 		 *
22213 		 * In any case, we do not want to loop around for another
22214 		 * send without a good reason.
22215 		 */
22216 		sendalot = 0;
22217 		switch (error) {
22218 		case EPERM:
22219 		case EACCES:
22220 			tp->t_softerror = error;
22221 #ifdef TCP_ACCOUNTING
22222 			crtsc = get_cyclecount();
22223 			if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
22224 				tp->tcp_cnt_counters[SND_OUT_FAIL]++;
22225 				tp->tcp_proc_time[SND_OUT_FAIL] += (crtsc - ts_val);
22226 			}
22227 			sched_unpin();
22228 #endif
22229 			return (error);
22230 		case ENOBUFS:
22231 			/*
22232 			 * Pace us right away to retry in a some
22233 			 * time
22234 			 */
22235 			if (rack->r_ctl.crte != NULL) {
22236 				tcp_trace_point(rack->rc_tp, TCP_TP_HWENOBUF);
22237 				if (tcp_bblogging_on(rack->rc_tp))
22238 					rack_log_queue_level(tp, rack, len, &tv, cts);
22239 			} else
22240 				tcp_trace_point(rack->rc_tp, TCP_TP_ENOBUF);
22241 			pacing_delay = ((1 + rack->rc_enobuf) * HPTS_USEC_IN_MSEC);
22242 			if (rack->rc_enobuf < 0x7f)
22243 				rack->rc_enobuf++;
22244 			if (pacing_delay < (10 * HPTS_USEC_IN_MSEC))
22245 				pacing_delay = 10 * HPTS_USEC_IN_MSEC;
22246 			if (rack->r_ctl.crte != NULL) {
22247 				counter_u64_add(rack_saw_enobuf_hw, 1);
22248 				tcp_rl_log_enobuf(rack->r_ctl.crte);
22249 			}
22250 			counter_u64_add(rack_saw_enobuf, 1);
22251 			goto enobufs;
22252 		case EMSGSIZE:
22253 			/*
22254 			 * For some reason the interface we used initially
22255 			 * to send segments changed to another or lowered
22256 			 * its MTU. If TSO was active we either got an
22257 			 * interface without TSO capabilits or TSO was
22258 			 * turned off. If we obtained mtu from ip_output()
22259 			 * then update it and try again.
22260 			 */
22261 			if (tso)
22262 				tp->t_flags &= ~TF_TSO;
22263 			if (mtu != 0) {
22264 				int saved_mtu;
22265 
22266 				saved_mtu = tp->t_maxseg;
22267 				tcp_mss_update(tp, -1, mtu, NULL, NULL);
22268 				if (saved_mtu > tp->t_maxseg) {
22269 					goto again;
22270 				}
22271 			}
22272 			pacing_delay = 10 * HPTS_USEC_IN_MSEC;
22273 			rack_start_hpts_timer(rack, tp, cts, pacing_delay, 0, 0);
22274 #ifdef TCP_ACCOUNTING
22275 			crtsc = get_cyclecount();
22276 			if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
22277 				tp->tcp_cnt_counters[SND_OUT_FAIL]++;
22278 				tp->tcp_proc_time[SND_OUT_FAIL] += (crtsc - ts_val);
22279 			}
22280 			sched_unpin();
22281 #endif
22282 			return (error);
22283 		case ENETUNREACH:
22284 			counter_u64_add(rack_saw_enetunreach, 1);
22285 			/* FALLTHROUGH */
22286 		case EHOSTDOWN:
22287 		case EHOSTUNREACH:
22288 		case ENETDOWN:
22289 			if (TCPS_HAVERCVDSYN(tp->t_state)) {
22290 				tp->t_softerror = error;
22291 				error = 0;
22292 			}
22293 			/* FALLTHROUGH */
22294 		default:
22295 			pacing_delay = 10 * HPTS_USEC_IN_MSEC;
22296 			rack_start_hpts_timer(rack, tp, cts, pacing_delay, 0, 0);
22297 #ifdef TCP_ACCOUNTING
22298 			crtsc = get_cyclecount();
22299 			if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
22300 				tp->tcp_cnt_counters[SND_OUT_FAIL]++;
22301 				tp->tcp_proc_time[SND_OUT_FAIL] += (crtsc - ts_val);
22302 			}
22303 			sched_unpin();
22304 #endif
22305 			return (error);
22306 		}
22307 	} else {
22308 		rack->rc_enobuf = 0;
22309 		if (IN_FASTRECOVERY(tp->t_flags) && rsm)
22310 			rack->r_ctl.retran_during_recovery += len;
22311 	}
22312 	KMOD_TCPSTAT_INC(tcps_sndtotal);
22313 
22314 	/*
22315 	 * Data sent (as far as we can tell). If this advertises a larger
22316 	 * window than any other segment, then remember the size of the
22317 	 * advertised window. Any pending ACK has now been sent.
22318 	 */
22319 	if (recwin > 0 && SEQ_GT(tp->rcv_nxt + recwin, tp->rcv_adv))
22320 		tp->rcv_adv = tp->rcv_nxt + recwin;
22321 
22322 	tp->last_ack_sent = tp->rcv_nxt;
22323 	tp->t_flags &= ~(TF_ACKNOW | TF_DELACK);
22324 enobufs:
22325 	if (sendalot) {
22326 		/* Do we need to turn off sendalot? */
22327 		if (pace_max_seg &&
22328 		    (tot_len_this_send >= pace_max_seg)) {
22329 			/* We hit our max. */
22330 			sendalot = 0;
22331 		}
22332 	}
22333 	if ((error == 0) && (flags & TH_FIN))
22334 		tcp_log_end_status(tp, TCP_EI_STATUS_SERVER_FIN);
22335 	if (flags & TH_RST) {
22336 		/*
22337 		 * We don't send again after sending a RST.
22338 		 */
22339 		pacing_delay = 0;
22340 		sendalot = 0;
22341 		if (error == 0)
22342 			tcp_log_end_status(tp, TCP_EI_STATUS_SERVER_RST);
22343 	} else if ((pacing_delay == 0) && (sendalot == 0) && tot_len_this_send) {
22344 		/*
22345 		 * Get our pacing rate, if an error
22346 		 * occurred in sending (ENOBUF) we would
22347 		 * hit the else if with slot preset. Other
22348 		 * errors return.
22349 		 */
22350 		pacing_delay = rack_get_pacing_delay(rack, tp, tot_len_this_send, rsm, segsiz, __LINE__);
22351 	}
22352 	/* We have sent clear the flag */
22353 	rack->r_ent_rec_ns = 0;
22354 	if (rack->r_must_retran) {
22355 		if (rsm) {
22356 			rack->r_ctl.rc_out_at_rto -= (rsm->r_end - rsm->r_start);
22357 			if (SEQ_GEQ(rsm->r_end, rack->r_ctl.rc_snd_max_at_rto)) {
22358 				/*
22359 				 * We have retransmitted all.
22360 				 */
22361 				rack->r_must_retran = 0;
22362 				rack->r_ctl.rc_out_at_rto = 0;
22363 			}
22364 		} else if (SEQ_GEQ(tp->snd_max, rack->r_ctl.rc_snd_max_at_rto)) {
22365 			/*
22366 			 * Sending new data will also kill
22367 			 * the loop.
22368 			 */
22369 			rack->r_must_retran = 0;
22370 			rack->r_ctl.rc_out_at_rto = 0;
22371 		}
22372 	}
22373 	rack->r_ctl.fsb.recwin = recwin;
22374 	if ((tp->t_flags & (TF_WASCRECOVERY|TF_WASFRECOVERY)) &&
22375 	    SEQ_GT(tp->snd_max, rack->r_ctl.rc_snd_max_at_rto)) {
22376 		/*
22377 		 * We hit an RTO and now have past snd_max at the RTO
22378 		 * clear all the WAS flags.
22379 		 */
22380 		tp->t_flags &= ~(TF_WASCRECOVERY|TF_WASFRECOVERY);
22381 	}
22382 	if (pacing_delay) {
22383 		/* set the rack tcb into the slot N */
22384 		if ((error == 0) &&
22385 		    rack_use_rfo &&
22386 		    ((flags & (TH_SYN|TH_FIN)) == 0) &&
22387 		    (rsm == NULL) &&
22388 		    (ipoptlen == 0) &&
22389 		    (doing_tlp == 0) &&
22390 		    rack->r_fsb_inited &&
22391 		    TCPS_HAVEESTABLISHED(tp->t_state) &&
22392 		    ((IN_RECOVERY(tp->t_flags)) == 0) &&
22393 		    (rack->r_must_retran == 0) &&
22394 		    ((tp->t_flags & TF_NEEDFIN) == 0) &&
22395 		    (len > 0) && (orig_len > 0) &&
22396 		    (orig_len > len) &&
22397 		    ((orig_len - len) >= segsiz) &&
22398 		    ((optlen == 0) ||
22399 		     ((optlen == TCPOLEN_TSTAMP_APPA) && (to.to_flags & TOF_TS)))) {
22400 			/* We can send at least one more MSS using our fsb */
22401 			rack_setup_fast_output(tp, rack, sb, len, orig_len,
22402 					       segsiz, pace_max_seg, hw_tls, flags);
22403 		} else
22404 			rack->r_fast_output = 0;
22405 		rack_log_fsb(rack, tp, so, flags,
22406 			     ipoptlen, orig_len, len, error,
22407 			     (rsm == NULL), optlen, __LINE__, 2);
22408 	} else if (sendalot) {
22409 		int ret;
22410 
22411 		sack_rxmit = 0;
22412 		if ((error == 0) &&
22413 		    rack_use_rfo &&
22414 		    ((flags & (TH_SYN|TH_FIN)) == 0) &&
22415 		    (rsm == NULL) &&
22416 		    (doing_tlp == 0) &&
22417 		    (ipoptlen == 0) &&
22418 		    (rack->r_must_retran == 0) &&
22419 		    rack->r_fsb_inited &&
22420 		    TCPS_HAVEESTABLISHED(tp->t_state) &&
22421 		    ((IN_RECOVERY(tp->t_flags)) == 0) &&
22422 		    ((tp->t_flags & TF_NEEDFIN) == 0) &&
22423 		    (len > 0) && (orig_len > 0) &&
22424 		    (orig_len > len) &&
22425 		    ((orig_len - len) >= segsiz) &&
22426 		    ((optlen == 0) ||
22427 		     ((optlen == TCPOLEN_TSTAMP_APPA) && (to.to_flags & TOF_TS)))) {
22428 			/* we can use fast_output for more */
22429 			rack_setup_fast_output(tp, rack, sb, len, orig_len,
22430 					       segsiz, pace_max_seg, hw_tls, flags);
22431 			if (rack->r_fast_output) {
22432 				error = 0;
22433 				ret = rack_fast_output(tp, rack, ts_val, cts, ms_cts, &tv, &tot_len_this_send, &error, __LINE__);
22434 				if (ret >= 0)
22435 					return (ret);
22436 			        else if (error)
22437 					goto nomore;
22438 
22439 			}
22440 		}
22441 		goto again;
22442 	}
22443 skip_all_send:
22444 	/* Assure when we leave that snd_nxt will point to top */
22445 	if (SEQ_GT(tp->snd_max, tp->snd_nxt))
22446 		tp->snd_nxt = tp->snd_max;
22447 	rack_start_hpts_timer(rack, tp, cts, pacing_delay, tot_len_this_send, 0);
22448 #ifdef TCP_ACCOUNTING
22449 	crtsc = get_cyclecount() - ts_val;
22450 	if (tot_len_this_send) {
22451 		if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
22452 			tp->tcp_cnt_counters[SND_OUT_DATA]++;
22453 			tp->tcp_proc_time[SND_OUT_DATA] += crtsc;
22454 			tp->tcp_cnt_counters[CNT_OF_MSS_OUT] += ((tot_len_this_send + segsiz - 1) /segsiz);
22455 		}
22456 	} else {
22457 		if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
22458 			tp->tcp_cnt_counters[SND_OUT_ACK]++;
22459 			tp->tcp_proc_time[SND_OUT_ACK] += crtsc;
22460 		}
22461 	}
22462 	sched_unpin();
22463 #endif
22464 	if (error == ENOBUFS)
22465 		error = 0;
22466 	return (error);
22467 }
22468 
22469 static void
22470 rack_update_seg(struct tcp_rack *rack)
22471 {
22472 	uint32_t orig_val;
22473 
22474 	orig_val = rack->r_ctl.rc_pace_max_segs;
22475 	rack_set_pace_segments(rack->rc_tp, rack, __LINE__, NULL);
22476 	if (orig_val != rack->r_ctl.rc_pace_max_segs)
22477 		rack_log_pacing_delay_calc(rack, 0, 0, orig_val, 0, 0, 15, __LINE__, NULL, 0);
22478 }
22479 
22480 static void
22481 rack_mtu_change(struct tcpcb *tp)
22482 {
22483 	/*
22484 	 * The MSS may have changed
22485 	 */
22486 	struct tcp_rack *rack;
22487 	struct rack_sendmap *rsm;
22488 
22489 	rack = (struct tcp_rack *)tp->t_fb_ptr;
22490 	if (rack->r_ctl.rc_pace_min_segs != ctf_fixed_maxseg(tp)) {
22491 		/*
22492 		 * The MTU has changed we need to resend everything
22493 		 * since all we have sent is lost. We first fix
22494 		 * up the mtu though.
22495 		 */
22496 		rack_set_pace_segments(tp, rack, __LINE__, NULL);
22497 		/* We treat this like a full retransmit timeout without the cwnd adjustment */
22498 		rack_remxt_tmr(tp);
22499 		rack->r_fast_output = 0;
22500 		rack->r_ctl.rc_out_at_rto = ctf_flight_size(tp,
22501 						rack->r_ctl.rc_sacked);
22502 		rack->r_ctl.rc_snd_max_at_rto = tp->snd_max;
22503 		rack->r_must_retran = 1;
22504 		/* Mark all inflight to needing to be rxt'd */
22505 		TAILQ_FOREACH(rsm, &rack->r_ctl.rc_tmap, r_tnext) {
22506 			rsm->r_flags |= (RACK_MUST_RXT|RACK_PMTU_CHG);
22507 		}
22508 	}
22509 	sack_filter_clear(&rack->r_ctl.rack_sf, tp->snd_una);
22510 	/* We don't use snd_nxt to retransmit */
22511 	tp->snd_nxt = tp->snd_max;
22512 }
22513 
22514 static int
22515 rack_set_dgp(struct tcp_rack *rack)
22516 {
22517 	if (rack->dgp_on == 1)
22518 		return(0);
22519 	if ((rack->use_fixed_rate == 1) &&
22520 	    (rack->rc_always_pace == 1)) {
22521 		/*
22522 		 * We are already pacing another
22523 		 * way.
22524 		 */
22525 		return (EBUSY);
22526 	}
22527 	if (rack->rc_always_pace == 1) {
22528 		rack_remove_pacing(rack);
22529 	}
22530 	if (tcp_incr_dgp_pacing_cnt() == 0)
22531 		return (ENOSPC);
22532 	rack->r_ctl.pacing_method |= RACK_DGP_PACING;
22533 	rack->rc_fillcw_apply_discount = 0;
22534 	rack->dgp_on = 1;
22535 	rack->rc_always_pace = 1;
22536 	rack->rc_pace_dnd = 1;
22537 	rack->use_fixed_rate = 0;
22538 	if (rack->gp_ready)
22539 		rack_set_cc_pacing(rack);
22540 	rack->rc_tp->t_flags2 |= TF2_SUPPORTS_MBUFQ;
22541 	rack->rack_attempt_hdwr_pace = 0;
22542 	/* rxt settings */
22543 	rack->full_size_rxt = 1;
22544 	rack->shape_rxt_to_pacing_min  = 0;
22545 	/* cmpack=1 */
22546 	rack->r_use_cmp_ack = 1;
22547 	if (TCPS_HAVEESTABLISHED(rack->rc_tp->t_state) &&
22548 	    rack->r_use_cmp_ack)
22549 		rack->rc_tp->t_flags2 |= TF2_MBUF_ACKCMP;
22550 	/* scwnd=1 */
22551 	rack->rack_enable_scwnd = 1;
22552 	/* dynamic=100 */
22553 	rack->rc_gp_dyn_mul = 1;
22554 	/* gp_inc_ca */
22555 	rack->r_ctl.rack_per_of_gp_ca = 100;
22556 	/* rrr_conf=3 */
22557 	rack->r_rr_config = 3;
22558 	/* npush=2 */
22559 	rack->r_ctl.rc_no_push_at_mrtt = 2;
22560 	/* fillcw=1 */
22561 	rack->rc_pace_to_cwnd = 1;
22562 	rack->rc_pace_fill_if_rttin_range = 0;
22563 	rack->rtt_limit_mul = 0;
22564 	/* noprr=1 */
22565 	rack->rack_no_prr = 1;
22566 	/* lscwnd=1 */
22567 	rack->r_limit_scw = 1;
22568 	/* gp_inc_rec */
22569 	rack->r_ctl.rack_per_of_gp_rec = 90;
22570 	return (0);
22571 }
22572 
22573 static int
22574 rack_set_profile(struct tcp_rack *rack, int prof)
22575 {
22576 	int err = EINVAL;
22577 	if (prof == 1) {
22578 		/*
22579 		 * Profile 1 is "standard" DGP. It ignores
22580 		 * client buffer level.
22581 		 */
22582 		err = rack_set_dgp(rack);
22583 		if (err)
22584 			return (err);
22585 	} else if (prof == 6) {
22586 		err = rack_set_dgp(rack);
22587 		if (err)
22588 			return (err);
22589 		/*
22590 		 * Profile 6 tweaks DGP so that it will apply to
22591 		 * fill-cw the same settings that profile5 does
22592 		 * to replace DGP. It gets then the max(dgp-rate, fillcw(discounted).
22593 		 */
22594 		rack->rc_fillcw_apply_discount = 1;
22595 	} else if (prof == 0) {
22596 		/* This changes things back to the default settings */
22597 		if (rack->rc_always_pace == 1) {
22598 			rack_remove_pacing(rack);
22599 		} else {
22600 			/* Make sure any stray flags are off */
22601 			rack->dgp_on = 0;
22602 			rack->rc_hybrid_mode = 0;
22603 			rack->use_fixed_rate = 0;
22604 		}
22605 		err = 0;
22606 		if (rack_fill_cw_state)
22607 			rack->rc_pace_to_cwnd = 1;
22608 		else
22609 			rack->rc_pace_to_cwnd = 0;
22610 
22611 		if (rack_pace_every_seg && tcp_can_enable_pacing()) {
22612 			rack->r_ctl.pacing_method |= RACK_REG_PACING;
22613 			rack->rc_always_pace = 1;
22614 			if (rack->rack_hibeta)
22615 				rack_set_cc_pacing(rack);
22616 		} else
22617 			rack->rc_always_pace = 0;
22618 		if (rack_dsack_std_based & 0x1) {
22619 			/* Basically this means all rack timers are at least (srtt + 1/4 srtt) */
22620 			rack->rc_rack_tmr_std_based = 1;
22621 		}
22622 		if (rack_dsack_std_based & 0x2) {
22623 			/* Basically this means  rack timers are extended based on dsack by up to (2 * srtt) */
22624 			rack->rc_rack_use_dsack = 1;
22625 		}
22626 		if (rack_use_cmp_acks)
22627 			rack->r_use_cmp_ack = 1;
22628 		else
22629 			rack->r_use_cmp_ack = 0;
22630 		if (rack_disable_prr)
22631 			rack->rack_no_prr = 1;
22632 		else
22633 			rack->rack_no_prr = 0;
22634 		if (rack_gp_no_rec_chg)
22635 			rack->rc_gp_no_rec_chg = 1;
22636 		else
22637 			rack->rc_gp_no_rec_chg = 0;
22638 		if (rack_enable_mqueue_for_nonpaced || rack->r_use_cmp_ack) {
22639 			rack->r_mbuf_queue = 1;
22640 			if (TCPS_HAVEESTABLISHED(rack->rc_tp->t_state))
22641 				rack->rc_tp->t_flags2 |= TF2_MBUF_ACKCMP;
22642 			rack->rc_tp->t_flags2 |= TF2_SUPPORTS_MBUFQ;
22643 		} else {
22644 			rack->r_mbuf_queue = 0;
22645 			rack->rc_tp->t_flags2 &= ~TF2_SUPPORTS_MBUFQ;
22646 		}
22647 		if (rack_enable_shared_cwnd)
22648 			rack->rack_enable_scwnd = 1;
22649 		else
22650 			rack->rack_enable_scwnd = 0;
22651 		if (rack_do_dyn_mul) {
22652 			/* When dynamic adjustment is on CA needs to start at 100% */
22653 			rack->rc_gp_dyn_mul = 1;
22654 			if (rack_do_dyn_mul >= 100)
22655 				rack->r_ctl.rack_per_of_gp_ca = rack_do_dyn_mul;
22656 		} else {
22657 			rack->r_ctl.rack_per_of_gp_ca = rack_per_of_gp_ca;
22658 			rack->rc_gp_dyn_mul = 0;
22659 		}
22660 		rack->r_rr_config = 0;
22661 		rack->r_ctl.rc_no_push_at_mrtt = 0;
22662 		rack->rc_pace_fill_if_rttin_range = 0;
22663 		rack->rtt_limit_mul = 0;
22664 
22665 		if (rack_enable_hw_pacing)
22666 			rack->rack_hdw_pace_ena = 1;
22667 		else
22668 			rack->rack_hdw_pace_ena = 0;
22669 		if (rack_disable_prr)
22670 			rack->rack_no_prr = 1;
22671 		else
22672 			rack->rack_no_prr = 0;
22673 		if (rack_limits_scwnd)
22674 			rack->r_limit_scw  = 1;
22675 		else
22676 			rack->r_limit_scw  = 0;
22677 		rack_init_retransmit_value(rack, rack_rxt_controls);
22678 		err = 0;
22679 	}
22680 	return (err);
22681 }
22682 
22683 static int
22684 rack_add_deferred_option(struct tcp_rack *rack, int sopt_name, uint64_t loptval)
22685 {
22686 	struct deferred_opt_list *dol;
22687 
22688 	dol = malloc(sizeof(struct deferred_opt_list),
22689 		     M_TCPDO, M_NOWAIT|M_ZERO);
22690 	if (dol == NULL) {
22691 		/*
22692 		 * No space yikes -- fail out..
22693 		 */
22694 		return (0);
22695 	}
22696 	dol->optname = sopt_name;
22697 	dol->optval = loptval;
22698 	TAILQ_INSERT_TAIL(&rack->r_ctl.opt_list, dol, next);
22699 	return (1);
22700 }
22701 
22702 static int
22703 process_hybrid_pacing(struct tcp_rack *rack, struct tcp_hybrid_req *hybrid)
22704 {
22705 #ifdef TCP_REQUEST_TRK
22706 	struct tcp_sendfile_track *sft;
22707 	struct timeval tv;
22708 	tcp_seq seq;
22709 	int err;
22710 
22711 	microuptime(&tv);
22712 
22713 	/* Make sure no fixed rate is on */
22714 	rack->use_fixed_rate = 0;
22715 	rack->r_ctl.rc_fixed_pacing_rate_rec = 0;
22716 	rack->r_ctl.rc_fixed_pacing_rate_ca = 0;
22717 	rack->r_ctl.rc_fixed_pacing_rate_ss = 0;
22718 	/* Now allocate or find our entry that will have these settings */
22719 	sft = tcp_req_alloc_req_full(rack->rc_tp, &hybrid->req, tcp_tv_to_lusec(&tv), 0);
22720 	if (sft == NULL) {
22721 		rack->rc_tp->tcp_hybrid_error++;
22722 		/* no space, where would it have gone? */
22723 		seq = rack->rc_tp->snd_una + rack->rc_tp->t_inpcb.inp_socket->so_snd.sb_ccc;
22724 		rack_log_hybrid(rack, seq, NULL, HYBRID_LOG_NO_ROOM, __LINE__, 0);
22725 		return (ENOSPC);
22726 	}
22727 	/* mask our internal flags */
22728 	hybrid->hybrid_flags &= TCP_HYBRID_PACING_USER_MASK;
22729 	/* The seq will be snd_una + everything in the buffer */
22730 	seq = sft->start_seq;
22731 	if ((hybrid->hybrid_flags & TCP_HYBRID_PACING_ENABLE) == 0) {
22732 		/* Disabling hybrid pacing */
22733 		if (rack->rc_hybrid_mode) {
22734 			rack_set_profile(rack, 0);
22735 			rack->rc_tp->tcp_hybrid_stop++;
22736 		}
22737 		rack_log_hybrid(rack, seq, sft, HYBRID_LOG_TURNED_OFF, __LINE__, 0);
22738 		return (0);
22739 	}
22740 	if (rack->dgp_on == 0) {
22741 		/*
22742 		 * If we have not yet turned DGP on, do so
22743 		 * now setting pure DGP mode, no buffer level
22744 		 * response.
22745 		 */
22746 		if ((err = rack_set_profile(rack, 1)) != 0){
22747 			/* Failed to turn pacing on */
22748 			rack->rc_tp->tcp_hybrid_error++;
22749 			rack_log_hybrid(rack, seq, sft, HYBRID_LOG_NO_PACING, __LINE__, 0);
22750 			return (err);
22751 		}
22752 	}
22753 	/*
22754 	 * Now we must switch to hybrid mode as well which also
22755 	 * means moving to regular pacing.
22756 	 */
22757 	if (rack->rc_hybrid_mode == 0) {
22758 		/* First time */
22759 		if (tcp_can_enable_pacing()) {
22760 			rack->r_ctl.pacing_method |= RACK_REG_PACING;
22761 			rack->rc_hybrid_mode = 1;
22762 		} else {
22763 			return (ENOSPC);
22764 		}
22765 		if (rack->r_ctl.pacing_method & RACK_DGP_PACING) {
22766 			/*
22767 			 * This should be true.
22768 			 */
22769 			tcp_dec_dgp_pacing_cnt();
22770 			rack->r_ctl.pacing_method &= ~RACK_DGP_PACING;
22771 		}
22772 	}
22773 	/* Now set in our flags */
22774 	sft->hybrid_flags = hybrid->hybrid_flags | TCP_HYBRID_PACING_WASSET;
22775 	if (hybrid->hybrid_flags & TCP_HYBRID_PACING_CSPR)
22776 		sft->cspr = hybrid->cspr;
22777 	else
22778 		sft->cspr = 0;
22779 	if (hybrid->hybrid_flags & TCP_HYBRID_PACING_H_MS)
22780 		sft->hint_maxseg = hybrid->hint_maxseg;
22781 	else
22782 		sft->hint_maxseg = 0;
22783 	rack->rc_tp->tcp_hybrid_start++;
22784 	rack_log_hybrid(rack, seq, sft, HYBRID_LOG_RULES_SET, __LINE__,0);
22785 	return (0);
22786 #else
22787 	return (ENOTSUP);
22788 #endif
22789 }
22790 
22791 static int
22792 rack_stack_information(struct tcpcb *tp, struct stack_specific_info *si)
22793 {
22794 	/* We pulled a SSI info log out what was there */
22795 	si->bytes_transmitted = tp->t_sndbytes;
22796 	si->bytes_retransmitted = tp->t_snd_rxt_bytes;
22797 	return (0);
22798 }
22799 
22800 static int
22801 rack_process_option(struct tcpcb *tp, struct tcp_rack *rack, int sopt_name,
22802 		    uint32_t optval, uint64_t loptval, struct tcp_hybrid_req *hybrid)
22803 
22804 {
22805 	struct epoch_tracker et;
22806 	struct sockopt sopt;
22807 	struct cc_newreno_opts opt;
22808 	uint64_t val;
22809 	int error = 0;
22810 	uint16_t ca, ss;
22811 
22812 	switch (sopt_name) {
22813 	case TCP_RACK_SET_RXT_OPTIONS:
22814 		if (optval <= 2) {
22815 			rack_init_retransmit_value(rack, optval);
22816 		} else {
22817 			/*
22818 			 * You must send in 0, 1 or 2 all else is
22819 			 * invalid.
22820 			 */
22821 			error = EINVAL;
22822 		}
22823 		break;
22824 	case TCP_RACK_DSACK_OPT:
22825 		RACK_OPTS_INC(tcp_rack_dsack_opt);
22826 		if (optval & 0x1) {
22827 			rack->rc_rack_tmr_std_based = 1;
22828 		} else {
22829 			rack->rc_rack_tmr_std_based = 0;
22830 		}
22831 		if (optval & 0x2) {
22832 			rack->rc_rack_use_dsack = 1;
22833 		} else {
22834 			rack->rc_rack_use_dsack = 0;
22835 		}
22836 		rack_log_dsack_event(rack, 5, __LINE__, 0, 0);
22837 		break;
22838 	case TCP_RACK_PACING_DIVISOR:
22839 		RACK_OPTS_INC(tcp_rack_pacing_divisor);
22840 		if (optval == 0) {
22841 			rack->r_ctl.pace_len_divisor = rack_default_pacing_divisor;
22842 		} else {
22843 			if (optval < RL_MIN_DIVISOR)
22844 				rack->r_ctl.pace_len_divisor = RL_MIN_DIVISOR;
22845 			else
22846 				rack->r_ctl.pace_len_divisor = optval;
22847 		}
22848 		break;
22849 	case TCP_RACK_HI_BETA:
22850 		RACK_OPTS_INC(tcp_rack_hi_beta);
22851 		if (optval > 0) {
22852 			rack->rack_hibeta = 1;
22853 			if ((optval >= 50) &&
22854 			    (optval <= 100)) {
22855 				/*
22856 				 * User wants to set a custom beta.
22857 				 */
22858 				rack->r_ctl.saved_hibeta = optval;
22859 				if (rack->rc_pacing_cc_set)
22860 					rack_undo_cc_pacing(rack);
22861 				rack->r_ctl.rc_saved_beta = optval;
22862 			}
22863 			if (rack->rc_pacing_cc_set == 0)
22864 				rack_set_cc_pacing(rack);
22865 		} else {
22866 			rack->rack_hibeta = 0;
22867 			if (rack->rc_pacing_cc_set)
22868 				rack_undo_cc_pacing(rack);
22869 		}
22870 		break;
22871 	case TCP_RACK_PACING_BETA:
22872 		error = EINVAL;
22873 		break;
22874 	case TCP_RACK_TIMER_SLOP:
22875 		RACK_OPTS_INC(tcp_rack_timer_slop);
22876 		rack->r_ctl.timer_slop = optval;
22877 		if (rack->rc_tp->t_srtt) {
22878 			/*
22879 			 * If we have an SRTT lets update t_rxtcur
22880 			 * to have the new slop.
22881 			 */
22882 			RACK_TCPT_RANGESET(tp->t_rxtcur, RACK_REXMTVAL(tp),
22883 					   rack_rto_min, rack_rto_max,
22884 					   rack->r_ctl.timer_slop);
22885 		}
22886 		break;
22887 	case TCP_RACK_PACING_BETA_ECN:
22888 		RACK_OPTS_INC(tcp_rack_beta_ecn);
22889 		if (strcmp(tp->t_cc->name, CCALGONAME_NEWRENO) != 0) {
22890 			/* This only works for newreno. */
22891 			error = EINVAL;
22892 			break;
22893 		}
22894 		if (rack->rc_pacing_cc_set) {
22895 			/*
22896 			 * Set them into the real CC module
22897 			 * whats in the rack pcb is the old values
22898 			 * to be used on restoral/
22899 			 */
22900 			sopt.sopt_dir = SOPT_SET;
22901 			opt.name = CC_NEWRENO_BETA_ECN;
22902 			opt.val = optval;
22903 			if (CC_ALGO(tp)->ctl_output != NULL)
22904 				error = CC_ALGO(tp)->ctl_output(&tp->t_ccv, &sopt, &opt);
22905 			else
22906 				error = ENOENT;
22907 		} else {
22908 			/*
22909 			 * Not pacing yet so set it into our local
22910 			 * rack pcb storage.
22911 			 */
22912 			rack->r_ctl.rc_saved_beta_ecn = optval;
22913 		}
22914 		break;
22915 	case TCP_DEFER_OPTIONS:
22916 		RACK_OPTS_INC(tcp_defer_opt);
22917 		if (optval) {
22918 			if (rack->gp_ready) {
22919 				/* Too late */
22920 				error = EINVAL;
22921 				break;
22922 			}
22923 			rack->defer_options = 1;
22924 		} else
22925 			rack->defer_options = 0;
22926 		break;
22927 	case TCP_RACK_MEASURE_CNT:
22928 		RACK_OPTS_INC(tcp_rack_measure_cnt);
22929 		if (optval && (optval <= 0xff)) {
22930 			rack->r_ctl.req_measurements = optval;
22931 		} else
22932 			error = EINVAL;
22933 		break;
22934 	case TCP_REC_ABC_VAL:
22935 		RACK_OPTS_INC(tcp_rec_abc_val);
22936 		if (optval > 0)
22937 			rack->r_use_labc_for_rec = 1;
22938 		else
22939 			rack->r_use_labc_for_rec = 0;
22940 		break;
22941 	case TCP_RACK_ABC_VAL:
22942 		RACK_OPTS_INC(tcp_rack_abc_val);
22943 		if ((optval > 0) && (optval < 255))
22944 			rack->rc_labc = optval;
22945 		else
22946 			error = EINVAL;
22947 		break;
22948 	case TCP_HDWR_UP_ONLY:
22949 		RACK_OPTS_INC(tcp_pacing_up_only);
22950 		if (optval)
22951 			rack->r_up_only = 1;
22952 		else
22953 			rack->r_up_only = 0;
22954 		break;
22955 	case TCP_FILLCW_RATE_CAP:		/*  URL:fillcw_cap */
22956 		RACK_OPTS_INC(tcp_fillcw_rate_cap);
22957 		rack->r_ctl.fillcw_cap = loptval;
22958 		break;
22959 	case TCP_PACING_RATE_CAP:
22960 		RACK_OPTS_INC(tcp_pacing_rate_cap);
22961 		if ((rack->dgp_on == 1) &&
22962 		    (rack->r_ctl.pacing_method & RACK_DGP_PACING)) {
22963 			/*
22964 			 * If we are doing DGP we need to switch
22965 			 * to using the pacing limit.
22966 			 */
22967 			if (tcp_can_enable_pacing() == 0) {
22968 				error = ENOSPC;
22969 				break;
22970 			}
22971 			/*
22972 			 * Now change up the flags and counts to be correct.
22973 			 */
22974 			rack->r_ctl.pacing_method |= RACK_REG_PACING;
22975 			tcp_dec_dgp_pacing_cnt();
22976 			rack->r_ctl.pacing_method &= ~RACK_DGP_PACING;
22977 		}
22978 		rack->r_ctl.bw_rate_cap = loptval;
22979 		break;
22980 	case TCP_HYBRID_PACING:
22981 		if (hybrid == NULL) {
22982 			error = EINVAL;
22983 			break;
22984 		}
22985 		if (rack->r_ctl.side_chan_dis_mask & HYBRID_DIS_MASK) {
22986 			error = EPERM;
22987 			break;
22988 		}
22989 		error = process_hybrid_pacing(rack, hybrid);
22990 		break;
22991 	case TCP_SIDECHAN_DIS:			/*  URL:scodm */
22992 		if (optval)
22993 			rack->r_ctl.side_chan_dis_mask = optval;
22994 		else
22995 			rack->r_ctl.side_chan_dis_mask = 0;
22996 		break;
22997 	case TCP_RACK_PROFILE:
22998 		RACK_OPTS_INC(tcp_profile);
22999 		error = rack_set_profile(rack, optval);
23000 		break;
23001 	case TCP_USE_CMP_ACKS:
23002 		RACK_OPTS_INC(tcp_use_cmp_acks);
23003 		if ((optval == 0) && (tp->t_flags2 & TF2_MBUF_ACKCMP)) {
23004 			/* You can't turn it off once its on! */
23005 			error = EINVAL;
23006 		} else if ((optval == 1) && (rack->r_use_cmp_ack == 0)) {
23007 			rack->r_use_cmp_ack = 1;
23008 			rack->r_mbuf_queue = 1;
23009 			tp->t_flags2 |= TF2_SUPPORTS_MBUFQ;
23010 		}
23011 		if (rack->r_use_cmp_ack && TCPS_HAVEESTABLISHED(tp->t_state))
23012 			tp->t_flags2 |= TF2_MBUF_ACKCMP;
23013 		break;
23014 	case TCP_SHARED_CWND_TIME_LIMIT:
23015 		RACK_OPTS_INC(tcp_lscwnd);
23016 		if (optval)
23017 			rack->r_limit_scw = 1;
23018 		else
23019 			rack->r_limit_scw = 0;
23020 		break;
23021 	case TCP_RACK_DGP_IN_REC:
23022 		error = EINVAL;
23023 		break;
23024  	case TCP_RACK_PACE_TO_FILL:
23025 		RACK_OPTS_INC(tcp_fillcw);
23026 		if (optval == 0)
23027 			rack->rc_pace_to_cwnd = 0;
23028 		else {
23029 			rack->rc_pace_to_cwnd = 1;
23030 		}
23031 		if ((optval >= rack_gp_rtt_maxmul) &&
23032 		    rack_gp_rtt_maxmul &&
23033 		    (optval < 0xf)) {
23034 			rack->rc_pace_fill_if_rttin_range = 1;
23035 			rack->rtt_limit_mul = optval;
23036 		} else {
23037 			rack->rc_pace_fill_if_rttin_range = 0;
23038 			rack->rtt_limit_mul = 0;
23039 		}
23040 		break;
23041 	case TCP_RACK_NO_PUSH_AT_MAX:
23042 		RACK_OPTS_INC(tcp_npush);
23043 		if (optval == 0)
23044 			rack->r_ctl.rc_no_push_at_mrtt = 0;
23045 		else if (optval < 0xff)
23046 			rack->r_ctl.rc_no_push_at_mrtt = optval;
23047 		else
23048 			error = EINVAL;
23049 		break;
23050 	case TCP_SHARED_CWND_ENABLE:
23051 		RACK_OPTS_INC(tcp_rack_scwnd);
23052 		if (optval == 0)
23053 			rack->rack_enable_scwnd = 0;
23054 		else
23055 			rack->rack_enable_scwnd = 1;
23056 		break;
23057 	case TCP_RACK_MBUF_QUEUE:
23058 		/* Now do we use the LRO mbuf-queue feature */
23059 		RACK_OPTS_INC(tcp_rack_mbufq);
23060 		if (optval || rack->r_use_cmp_ack)
23061 			rack->r_mbuf_queue = 1;
23062 		else
23063 			rack->r_mbuf_queue = 0;
23064 		if  (rack->r_mbuf_queue || rack->rc_always_pace || rack->r_use_cmp_ack)
23065 			tp->t_flags2 |= TF2_SUPPORTS_MBUFQ;
23066 		else
23067 			tp->t_flags2 &= ~TF2_SUPPORTS_MBUFQ;
23068 		break;
23069 	case TCP_RACK_NONRXT_CFG_RATE:
23070 		RACK_OPTS_INC(tcp_rack_cfg_rate);
23071 		if (optval == 0)
23072 			rack->rack_rec_nonrxt_use_cr = 0;
23073 		else
23074 			rack->rack_rec_nonrxt_use_cr = 1;
23075 		break;
23076 	case TCP_NO_PRR:
23077 		RACK_OPTS_INC(tcp_rack_noprr);
23078 		if (optval == 0)
23079 			rack->rack_no_prr = 0;
23080 		else if (optval == 1)
23081 			rack->rack_no_prr = 1;
23082 		else if (optval == 2)
23083 			rack->no_prr_addback = 1;
23084 		else
23085 			error = EINVAL;
23086 		break;
23087 	case RACK_CSPR_IS_FCC:			/*  URL:csprisfcc */
23088 		if (optval > 0)
23089 			rack->cspr_is_fcc = 1;
23090 		else
23091 			rack->cspr_is_fcc = 0;
23092 		break;
23093 	case TCP_TIMELY_DYN_ADJ:
23094 		RACK_OPTS_INC(tcp_timely_dyn);
23095 		if (optval == 0)
23096 			rack->rc_gp_dyn_mul = 0;
23097 		else {
23098 			rack->rc_gp_dyn_mul = 1;
23099 			if (optval >= 100) {
23100 				/*
23101 				 * If the user sets something 100 or more
23102 				 * its the gp_ca value.
23103 				 */
23104 				rack->r_ctl.rack_per_of_gp_ca  = optval;
23105 			}
23106 		}
23107 		break;
23108 	case TCP_RACK_DO_DETECTION:
23109 		error = EINVAL;
23110 		break;
23111 	case TCP_RACK_TLP_USE:
23112 		if ((optval < TLP_USE_ID) || (optval > TLP_USE_TWO_TWO)) {
23113 			error = EINVAL;
23114 			break;
23115 		}
23116 		RACK_OPTS_INC(tcp_tlp_use);
23117 		rack->rack_tlp_threshold_use = optval;
23118 		break;
23119 	case TCP_RACK_TLP_REDUCE:
23120 		/* RACK TLP cwnd reduction (bool) */
23121 		RACK_OPTS_INC(tcp_rack_tlp_reduce);
23122 		rack->r_ctl.rc_tlp_cwnd_reduce = optval;
23123 		break;
23124 		/*  Pacing related ones */
23125 	case TCP_RACK_PACE_ALWAYS:
23126 		/*
23127 		 * zero is old rack method, 1 is new
23128 		 * method using a pacing rate.
23129 		 */
23130 		RACK_OPTS_INC(tcp_rack_pace_always);
23131 		if (rack->r_ctl.side_chan_dis_mask & CCSP_DIS_MASK) {
23132 			error = EPERM;
23133 			break;
23134 		}
23135 		if (optval > 0) {
23136 			if (rack->rc_always_pace) {
23137 				error = EALREADY;
23138 				break;
23139 			} else if (tcp_can_enable_pacing()) {
23140 				rack->r_ctl.pacing_method |= RACK_REG_PACING;
23141 				rack->rc_always_pace = 1;
23142 				if (rack->rack_hibeta)
23143 					rack_set_cc_pacing(rack);
23144 			}
23145 			else {
23146 				error = ENOSPC;
23147 				break;
23148 			}
23149 		} else {
23150 			if (rack->rc_always_pace == 1) {
23151 				rack_remove_pacing(rack);
23152 			}
23153 		}
23154 		if  (rack->r_mbuf_queue || rack->rc_always_pace || rack->r_use_cmp_ack)
23155 			tp->t_flags2 |= TF2_SUPPORTS_MBUFQ;
23156 		else
23157 			tp->t_flags2 &= ~TF2_SUPPORTS_MBUFQ;
23158 		/* A rate may be set irate or other, if so set seg size */
23159 		rack_update_seg(rack);
23160 		break;
23161 	case TCP_BBR_RACK_INIT_RATE:
23162 		RACK_OPTS_INC(tcp_initial_rate);
23163 		val = optval;
23164 		/* Change from kbits per second to bytes per second */
23165 		val *= 1000;
23166 		val /= 8;
23167 		rack->r_ctl.init_rate = val;
23168 		if (rack->rc_always_pace)
23169 			rack_update_seg(rack);
23170 		break;
23171 	case TCP_BBR_IWINTSO:
23172 		error = EINVAL;
23173 		break;
23174 	case TCP_RACK_FORCE_MSEG:
23175 		RACK_OPTS_INC(tcp_rack_force_max_seg);
23176 		if (optval)
23177 			rack->rc_force_max_seg = 1;
23178 		else
23179 			rack->rc_force_max_seg = 0;
23180 		break;
23181 	case TCP_RACK_PACE_MIN_SEG:
23182 		RACK_OPTS_INC(tcp_rack_min_seg);
23183 		rack->r_ctl.rc_user_set_min_segs = (0x0000ffff & optval);
23184 		rack_set_pace_segments(tp, rack, __LINE__, NULL);
23185 		break;
23186 	case TCP_RACK_PACE_MAX_SEG:
23187 		/* Max segments size in a pace in bytes */
23188 		RACK_OPTS_INC(tcp_rack_max_seg);
23189 		if ((rack->dgp_on == 1) &&
23190 		    (rack->r_ctl.pacing_method & RACK_DGP_PACING)) {
23191 			/*
23192 			 * If we set a max-seg and are doing DGP then
23193 			 * we now fall under the pacing limits not the
23194 			 * DGP ones.
23195 			 */
23196 			if (tcp_can_enable_pacing() == 0) {
23197 				error = ENOSPC;
23198 				break;
23199 			}
23200 			/*
23201 			 * Now change up the flags and counts to be correct.
23202 			 */
23203 			rack->r_ctl.pacing_method |= RACK_REG_PACING;
23204 			tcp_dec_dgp_pacing_cnt();
23205 			rack->r_ctl.pacing_method &= ~RACK_DGP_PACING;
23206 		}
23207 		if (optval <= MAX_USER_SET_SEG)
23208 			rack->rc_user_set_max_segs = optval;
23209 		else
23210 			rack->rc_user_set_max_segs = MAX_USER_SET_SEG;
23211 		rack_set_pace_segments(tp, rack, __LINE__, NULL);
23212 		break;
23213 	case TCP_RACK_PACE_RATE_REC:
23214 		/* Set the fixed pacing rate in Bytes per second ca */
23215 		RACK_OPTS_INC(tcp_rack_pace_rate_rec);
23216 		if (rack->r_ctl.side_chan_dis_mask & CCSP_DIS_MASK) {
23217 			error = EPERM;
23218 			break;
23219 		}
23220 		if (rack->dgp_on) {
23221 			/*
23222 			 * We are already pacing another
23223 			 * way.
23224 			 */
23225 			error = EBUSY;
23226 			break;
23227 		}
23228 		rack->r_ctl.rc_fixed_pacing_rate_rec = optval;
23229 		if (rack->r_ctl.rc_fixed_pacing_rate_ca == 0)
23230 			rack->r_ctl.rc_fixed_pacing_rate_ca = optval;
23231 		if (rack->r_ctl.rc_fixed_pacing_rate_ss == 0)
23232 			rack->r_ctl.rc_fixed_pacing_rate_ss = optval;
23233 		rack->use_fixed_rate = 1;
23234 		if (rack->rack_hibeta)
23235 			rack_set_cc_pacing(rack);
23236 		rack_log_pacing_delay_calc(rack,
23237 					   rack->r_ctl.rc_fixed_pacing_rate_ss,
23238 					   rack->r_ctl.rc_fixed_pacing_rate_ca,
23239 					   rack->r_ctl.rc_fixed_pacing_rate_rec, 0, 0, 8,
23240 					   __LINE__, NULL,0);
23241 		break;
23242 
23243 	case TCP_RACK_PACE_RATE_SS:
23244 		/* Set the fixed pacing rate in Bytes per second ca */
23245 		RACK_OPTS_INC(tcp_rack_pace_rate_ss);
23246 		if (rack->r_ctl.side_chan_dis_mask & CCSP_DIS_MASK) {
23247 			error = EPERM;
23248 			break;
23249 		}
23250 		if (rack->dgp_on) {
23251 			/*
23252 			 * We are already pacing another
23253 			 * way.
23254 			 */
23255 			error = EBUSY;
23256 			break;
23257 		}
23258 		rack->r_ctl.rc_fixed_pacing_rate_ss = optval;
23259 		if (rack->r_ctl.rc_fixed_pacing_rate_ca == 0)
23260 			rack->r_ctl.rc_fixed_pacing_rate_ca = optval;
23261 		if (rack->r_ctl.rc_fixed_pacing_rate_rec == 0)
23262 			rack->r_ctl.rc_fixed_pacing_rate_rec = optval;
23263 		rack->use_fixed_rate = 1;
23264 		if (rack->rack_hibeta)
23265 			rack_set_cc_pacing(rack);
23266 		rack_log_pacing_delay_calc(rack,
23267 					   rack->r_ctl.rc_fixed_pacing_rate_ss,
23268 					   rack->r_ctl.rc_fixed_pacing_rate_ca,
23269 					   rack->r_ctl.rc_fixed_pacing_rate_rec, 0, 0, 8,
23270 					   __LINE__, NULL, 0);
23271 		break;
23272 
23273 	case TCP_RACK_PACE_RATE_CA:
23274 		/* Set the fixed pacing rate in Bytes per second ca */
23275 		RACK_OPTS_INC(tcp_rack_pace_rate_ca);
23276 		if (rack->r_ctl.side_chan_dis_mask & CCSP_DIS_MASK) {
23277 			error = EPERM;
23278 			break;
23279 		}
23280 		if (rack->dgp_on) {
23281 			/*
23282 			 * We are already pacing another
23283 			 * way.
23284 			 */
23285 			error = EBUSY;
23286 			break;
23287 		}
23288 		rack->r_ctl.rc_fixed_pacing_rate_ca = optval;
23289 		if (rack->r_ctl.rc_fixed_pacing_rate_ss == 0)
23290 			rack->r_ctl.rc_fixed_pacing_rate_ss = optval;
23291 		if (rack->r_ctl.rc_fixed_pacing_rate_rec == 0)
23292 			rack->r_ctl.rc_fixed_pacing_rate_rec = optval;
23293 		rack->use_fixed_rate = 1;
23294 		if (rack->rack_hibeta)
23295 			rack_set_cc_pacing(rack);
23296 		rack_log_pacing_delay_calc(rack,
23297 					   rack->r_ctl.rc_fixed_pacing_rate_ss,
23298 					   rack->r_ctl.rc_fixed_pacing_rate_ca,
23299 					   rack->r_ctl.rc_fixed_pacing_rate_rec, 0, 0, 8,
23300 					   __LINE__, NULL, 0);
23301 		break;
23302 	case TCP_RACK_GP_INCREASE_REC:
23303 		RACK_OPTS_INC(tcp_gp_inc_rec);
23304 		rack->r_ctl.rack_per_of_gp_rec = optval;
23305 		rack_log_pacing_delay_calc(rack,
23306 					   rack->r_ctl.rack_per_of_gp_ss,
23307 					   rack->r_ctl.rack_per_of_gp_ca,
23308 					   rack->r_ctl.rack_per_of_gp_rec, 0, 0, 1,
23309 					   __LINE__, NULL, 0);
23310 		break;
23311 	case TCP_RACK_GP_INCREASE_CA:
23312 		RACK_OPTS_INC(tcp_gp_inc_ca);
23313 		ca = optval;
23314 		if (ca < 100) {
23315 			/*
23316 			 * We don't allow any reduction
23317 			 * over the GP b/w.
23318 			 */
23319 			error = EINVAL;
23320 			break;
23321 		}
23322 		rack->r_ctl.rack_per_of_gp_ca = ca;
23323 		rack_log_pacing_delay_calc(rack,
23324 					   rack->r_ctl.rack_per_of_gp_ss,
23325 					   rack->r_ctl.rack_per_of_gp_ca,
23326 					   rack->r_ctl.rack_per_of_gp_rec, 0, 0, 1,
23327 					   __LINE__, NULL, 0);
23328 		break;
23329 	case TCP_RACK_GP_INCREASE_SS:
23330 		RACK_OPTS_INC(tcp_gp_inc_ss);
23331 		ss = optval;
23332 		if (ss < 100) {
23333 			/*
23334 			 * We don't allow any reduction
23335 			 * over the GP b/w.
23336 			 */
23337 			error = EINVAL;
23338 			break;
23339 		}
23340 		rack->r_ctl.rack_per_of_gp_ss = ss;
23341 		rack_log_pacing_delay_calc(rack,
23342 					   rack->r_ctl.rack_per_of_gp_ss,
23343 					   rack->r_ctl.rack_per_of_gp_ca,
23344 					   rack->r_ctl.rack_per_of_gp_rec, 0, 0, 1,
23345 					   __LINE__, NULL, 0);
23346 		break;
23347 	case TCP_RACK_RR_CONF:
23348 		RACK_OPTS_INC(tcp_rack_rrr_no_conf_rate);
23349 		if (optval && optval <= 3)
23350 			rack->r_rr_config = optval;
23351 		else
23352 			rack->r_rr_config = 0;
23353 		break;
23354 	case TCP_PACING_DND:			/*  URL:dnd */
23355 		if (optval > 0)
23356 			rack->rc_pace_dnd = 1;
23357 		else
23358 			rack->rc_pace_dnd = 0;
23359 		break;
23360 	case TCP_HDWR_RATE_CAP:
23361 		RACK_OPTS_INC(tcp_hdwr_rate_cap);
23362 		if (optval) {
23363 			if (rack->r_rack_hw_rate_caps == 0)
23364 				rack->r_rack_hw_rate_caps = 1;
23365 			else
23366 				error = EALREADY;
23367 		} else {
23368 			rack->r_rack_hw_rate_caps = 0;
23369 		}
23370 		break;
23371 	case TCP_DGP_UPPER_BOUNDS:
23372 	{
23373 		uint8_t val;
23374 		val = optval & 0x0000ff;
23375 		rack->r_ctl.rack_per_upper_bound_ca = val;
23376 		val = (optval >> 16) & 0x0000ff;
23377 		rack->r_ctl.rack_per_upper_bound_ss = val;
23378 		break;
23379 	}
23380 	case TCP_SS_EEXIT:			/*  URL:eexit */
23381 		if (optval > 0) {
23382 			rack->r_ctl.gp_rnd_thresh =  optval & 0x0ff;
23383 			if (optval & 0x10000) {
23384 				rack->r_ctl.gate_to_fs = 1;
23385 			} else {
23386 				rack->r_ctl.gate_to_fs = 0;
23387 			}
23388 			if (optval & 0x20000) {
23389 				rack->r_ctl.use_gp_not_last = 1;
23390 			} else {
23391 				rack->r_ctl.use_gp_not_last = 0;
23392 			}
23393 			if (optval & 0xfffc0000) {
23394 				uint32_t v;
23395 
23396 				v = (optval >> 18) & 0x00003fff;
23397 				if (v >= 1000)
23398 					rack->r_ctl.gp_gain_req = v;
23399 			}
23400 		} else {
23401 			/* We do not do ss early exit at all */
23402 			rack->rc_initial_ss_comp = 1;
23403 			rack->r_ctl.gp_rnd_thresh = 0;
23404 		}
23405 		break;
23406 	case TCP_RACK_SPLIT_LIMIT:
23407 		RACK_OPTS_INC(tcp_split_limit);
23408 		rack->r_ctl.rc_split_limit = optval;
23409 		break;
23410 	case TCP_BBR_HDWR_PACE:
23411 		RACK_OPTS_INC(tcp_hdwr_pacing);
23412 		if (optval){
23413 			if (rack->rack_hdrw_pacing == 0) {
23414 				rack->rack_hdw_pace_ena = 1;
23415 				rack->rack_attempt_hdwr_pace = 0;
23416 			} else
23417 				error = EALREADY;
23418 		} else {
23419 			rack->rack_hdw_pace_ena = 0;
23420 #ifdef RATELIMIT
23421 			if (rack->r_ctl.crte != NULL) {
23422 				rack->rack_hdrw_pacing = 0;
23423 				rack->rack_attempt_hdwr_pace = 0;
23424 				tcp_rel_pacing_rate(rack->r_ctl.crte, tp);
23425 				rack->r_ctl.crte = NULL;
23426 			}
23427 #endif
23428 		}
23429 		break;
23430 		/*  End Pacing related ones */
23431 	case TCP_RACK_PRR_SENDALOT:
23432 		/* Allow PRR to send more than one seg */
23433 		RACK_OPTS_INC(tcp_rack_prr_sendalot);
23434 		rack->r_ctl.rc_prr_sendalot = optval;
23435 		break;
23436 	case TCP_RACK_MIN_TO:
23437 		/* Minimum time between rack t-o's in ms */
23438 		RACK_OPTS_INC(tcp_rack_min_to);
23439 		rack->r_ctl.rc_min_to = optval;
23440 		break;
23441 	case TCP_RACK_EARLY_SEG:
23442 		/* If early recovery max segments */
23443 		RACK_OPTS_INC(tcp_rack_early_seg);
23444 		rack->r_ctl.rc_early_recovery_segs = optval;
23445 		break;
23446 	case TCP_RACK_ENABLE_HYSTART:
23447 	{
23448 		if (optval) {
23449 			tp->t_ccv.flags |= CCF_HYSTART_ALLOWED;
23450 			if (rack_do_hystart > RACK_HYSTART_ON)
23451 				tp->t_ccv.flags |= CCF_HYSTART_CAN_SH_CWND;
23452 			if (rack_do_hystart > RACK_HYSTART_ON_W_SC)
23453 				tp->t_ccv.flags |= CCF_HYSTART_CONS_SSTH;
23454 		} else {
23455 			tp->t_ccv.flags &= ~(CCF_HYSTART_ALLOWED|CCF_HYSTART_CAN_SH_CWND|CCF_HYSTART_CONS_SSTH);
23456 		}
23457 	}
23458 	break;
23459 	case TCP_RACK_REORD_THRESH:
23460 		/* RACK reorder threshold (shift amount) */
23461 		RACK_OPTS_INC(tcp_rack_reord_thresh);
23462 		if ((optval > 0) && (optval < 31))
23463 			rack->r_ctl.rc_reorder_shift = optval;
23464 		else
23465 			error = EINVAL;
23466 		break;
23467 	case TCP_RACK_REORD_FADE:
23468 		/* Does reordering fade after ms time */
23469 		RACK_OPTS_INC(tcp_rack_reord_fade);
23470 		rack->r_ctl.rc_reorder_fade = optval;
23471 		break;
23472 	case TCP_RACK_TLP_THRESH:
23473 		/* RACK TLP theshold i.e. srtt+(srtt/N) */
23474 		RACK_OPTS_INC(tcp_rack_tlp_thresh);
23475 		if (optval)
23476 			rack->r_ctl.rc_tlp_threshold = optval;
23477 		else
23478 			error = EINVAL;
23479 		break;
23480 	case TCP_BBR_USE_RACK_RR:
23481 		RACK_OPTS_INC(tcp_rack_rr);
23482 		if (optval)
23483 			rack->use_rack_rr = 1;
23484 		else
23485 			rack->use_rack_rr = 0;
23486 		break;
23487 	case TCP_RACK_PKT_DELAY:
23488 		/* RACK added ms i.e. rack-rtt + reord + N */
23489 		RACK_OPTS_INC(tcp_rack_pkt_delay);
23490 		rack->r_ctl.rc_pkt_delay = optval;
23491 		break;
23492 	case TCP_DELACK:
23493 		RACK_OPTS_INC(tcp_rack_delayed_ack);
23494 		if (optval == 0)
23495 			tp->t_delayed_ack = 0;
23496 		else
23497 			tp->t_delayed_ack = 1;
23498 		if (tp->t_flags & TF_DELACK) {
23499 			tp->t_flags &= ~TF_DELACK;
23500 			tp->t_flags |= TF_ACKNOW;
23501 			NET_EPOCH_ENTER(et);
23502 			rack_output(tp);
23503 			NET_EPOCH_EXIT(et);
23504 		}
23505 		break;
23506 
23507 	case TCP_BBR_RACK_RTT_USE:
23508 		RACK_OPTS_INC(tcp_rack_rtt_use);
23509 		if ((optval != USE_RTT_HIGH) &&
23510 		    (optval != USE_RTT_LOW) &&
23511 		    (optval != USE_RTT_AVG))
23512 			error = EINVAL;
23513 		else
23514 			rack->r_ctl.rc_rate_sample_method = optval;
23515 		break;
23516 	case TCP_HONOR_HPTS_MIN:
23517 		RACK_OPTS_INC(tcp_honor_hpts);
23518 		if (optval) {
23519 			rack->r_use_hpts_min = 1;
23520 			/*
23521 			 * Must be between 2 - 80% to be a reduction else
23522 			 * we keep the default (10%).
23523 			 */
23524 			if ((optval > 1) && (optval <= 80)) {
23525 				rack->r_ctl.max_reduction = optval;
23526 			}
23527 		} else
23528 			rack->r_use_hpts_min = 0;
23529 		break;
23530 	case TCP_REC_IS_DYN:			/*  URL:dynrec */
23531 		RACK_OPTS_INC(tcp_dyn_rec);
23532 		if (optval)
23533 			rack->rc_gp_no_rec_chg = 1;
23534 		else
23535 			rack->rc_gp_no_rec_chg = 0;
23536 		break;
23537 	case TCP_NO_TIMELY:
23538 		RACK_OPTS_INC(tcp_notimely);
23539 		if (optval) {
23540 			rack->rc_skip_timely = 1;
23541 			rack->r_ctl.rack_per_of_gp_rec = 90;
23542 			rack->r_ctl.rack_per_of_gp_ca = 100;
23543 			rack->r_ctl.rack_per_of_gp_ss = 250;
23544 		} else {
23545 			rack->rc_skip_timely = 0;
23546 		}
23547 		break;
23548 	case TCP_GP_USE_LTBW:
23549 		if (optval == 0) {
23550 			rack->use_lesser_lt_bw = 0;
23551 			rack->dis_lt_bw = 1;
23552 		} else if (optval == 1) {
23553 			rack->use_lesser_lt_bw = 1;
23554 			rack->dis_lt_bw = 0;
23555 		} else if (optval == 2) {
23556 			rack->use_lesser_lt_bw = 0;
23557 			rack->dis_lt_bw = 0;
23558 		}
23559 		break;
23560 	case TCP_DATA_AFTER_CLOSE:
23561 		RACK_OPTS_INC(tcp_data_after_close);
23562 		if (optval)
23563 			rack->rc_allow_data_af_clo = 1;
23564 		else
23565 			rack->rc_allow_data_af_clo = 0;
23566 		break;
23567 	default:
23568 		break;
23569 	}
23570 	tcp_log_socket_option(tp, sopt_name, optval, error);
23571 	return (error);
23572 }
23573 
23574 static void
23575 rack_inherit(struct tcpcb *tp, struct inpcb *parent)
23576 {
23577 	/*
23578 	 * A new connection has been created (tp) and
23579 	 * the parent is the inpcb given. We want to
23580 	 * apply a read-lock to the parent (we are already
23581 	 * holding a write lock on the tp) and copy anything
23582 	 * out of the rack specific data as long as its tfb is
23583 	 * the same as ours i.e. we are the same stack. Otherwise
23584 	 * we just return.
23585 	 */
23586 	struct tcpcb *par;
23587 	struct tcp_rack *dest, *src;
23588 	int cnt = 0;
23589 
23590 	par = intotcpcb(parent);
23591 	if (par->t_fb != tp->t_fb) {
23592 		/* Not the same stack */
23593 		tcp_log_socket_option(tp, 0, 0, 1);
23594 		return;
23595 	}
23596 	/* Ok if we reach here lets setup the two rack pointers */
23597 	dest = (struct tcp_rack *)tp->t_fb_ptr;
23598 	src = (struct tcp_rack *)par->t_fb_ptr;
23599 	if ((src == NULL) || (dest == NULL)) {
23600 		/* Huh? */
23601 		tcp_log_socket_option(tp, 0, 0, 2);
23602 		return;
23603 	}
23604 	/* Now copy out anything we wish to inherit i.e. things in socket-options */
23605 	/* TCP_RACK_PROFILE we can't know but we can set DGP if its on */
23606 	if ((src->dgp_on) && (dest->dgp_on == 0)) {
23607 		/* Profile 1 had to be set via sock opt */
23608 		rack_set_dgp(dest);
23609 		cnt++;
23610 	}
23611 	/* TCP_RACK_SET_RXT_OPTIONS */
23612 	if (dest->full_size_rxt != src->full_size_rxt) {
23613 		dest->full_size_rxt = src->full_size_rxt;
23614 		cnt++;
23615 	}
23616 	if (dest->shape_rxt_to_pacing_min  != src->shape_rxt_to_pacing_min) {
23617 		dest->shape_rxt_to_pacing_min = src->shape_rxt_to_pacing_min;
23618 		cnt++;
23619 	}
23620 	/* TCP_RACK_DSACK_OPT */
23621 	if (dest->rc_rack_tmr_std_based != src->rc_rack_tmr_std_based) {
23622 		dest->rc_rack_tmr_std_based = src->rc_rack_tmr_std_based;
23623 		cnt++;
23624 	}
23625 	if (dest->rc_rack_use_dsack != src->rc_rack_use_dsack) {
23626 		dest->rc_rack_use_dsack = src->rc_rack_use_dsack;
23627 		cnt++;
23628 	}
23629 	/* TCP_RACK_PACING_DIVISOR */
23630 	if (dest->r_ctl.pace_len_divisor != src->r_ctl.pace_len_divisor) {
23631 		dest->r_ctl.pace_len_divisor = src->r_ctl.pace_len_divisor;
23632 		cnt++;
23633 	}
23634 	/* TCP_RACK_HI_BETA */
23635 	if (src->rack_hibeta != dest->rack_hibeta) {
23636 		cnt++;
23637 		if (src->rack_hibeta) {
23638 			dest->r_ctl.rc_saved_beta = src->r_ctl.rc_saved_beta;
23639 			dest->rack_hibeta = 1;
23640 		} else {
23641 			dest->rack_hibeta = 0;
23642 		}
23643 	}
23644 	/* TCP_RACK_TIMER_SLOP */
23645 	if (dest->r_ctl.timer_slop != src->r_ctl.timer_slop) {
23646 		dest->r_ctl.timer_slop = src->r_ctl.timer_slop;
23647 		cnt++;
23648 	}
23649 	/* TCP_RACK_PACING_BETA_ECN */
23650 	if (dest->r_ctl.rc_saved_beta_ecn != src->r_ctl.rc_saved_beta_ecn) {
23651 		dest->r_ctl.rc_saved_beta_ecn = src->r_ctl.rc_saved_beta_ecn;
23652 		cnt++;
23653 	}
23654 	/* We do not do TCP_DEFER_OPTIONS */
23655 	/* TCP_RACK_MEASURE_CNT */
23656 	if (dest->r_ctl.req_measurements != src->r_ctl.req_measurements) {
23657 		dest->r_ctl.req_measurements = src->r_ctl.req_measurements;
23658 		cnt++;
23659 	}
23660 	/* TCP_HDWR_UP_ONLY */
23661 	if (dest->r_up_only != src->r_up_only) {
23662 		dest->r_up_only = src->r_up_only;
23663 		cnt++;
23664 	}
23665 	/* TCP_FILLCW_RATE_CAP */
23666 	if (dest->r_ctl.fillcw_cap != src->r_ctl.fillcw_cap) {
23667 		dest->r_ctl.fillcw_cap = src->r_ctl.fillcw_cap;
23668 		cnt++;
23669 	}
23670 	/* TCP_PACING_RATE_CAP */
23671 	if (dest->r_ctl.bw_rate_cap != src->r_ctl.bw_rate_cap) {
23672 		dest->r_ctl.bw_rate_cap = src->r_ctl.bw_rate_cap;
23673 		cnt++;
23674 	}
23675 	/* A listener can't set TCP_HYBRID_PACING */
23676 	/* TCP_SIDECHAN_DIS */
23677 	if (dest->r_ctl.side_chan_dis_mask != src->r_ctl.side_chan_dis_mask) {
23678 		dest->r_ctl.side_chan_dis_mask = src->r_ctl.side_chan_dis_mask;
23679 		cnt++;
23680 	}
23681 	/* TCP_SHARED_CWND_TIME_LIMIT */
23682 	if (dest->r_limit_scw != src->r_limit_scw) {
23683 		dest->r_limit_scw = src->r_limit_scw;
23684 		cnt++;
23685 	}
23686 	/* TCP_RACK_PACE_TO_FILL */
23687 	if (dest->rc_pace_to_cwnd != src->rc_pace_to_cwnd) {
23688 		dest->rc_pace_to_cwnd = src->rc_pace_to_cwnd;
23689 		cnt++;
23690 	}
23691 	if (dest->rc_pace_fill_if_rttin_range != src->rc_pace_fill_if_rttin_range) {
23692 		dest->rc_pace_fill_if_rttin_range = src->rc_pace_fill_if_rttin_range;
23693 		cnt++;
23694 	}
23695 	if (dest->rtt_limit_mul != src->rtt_limit_mul) {
23696 		dest->rtt_limit_mul = src->rtt_limit_mul;
23697 		cnt++;
23698 	}
23699 	/* TCP_RACK_NO_PUSH_AT_MAX */
23700 	if (dest->r_ctl.rc_no_push_at_mrtt != src->r_ctl.rc_no_push_at_mrtt) {
23701 		dest->r_ctl.rc_no_push_at_mrtt = src->r_ctl.rc_no_push_at_mrtt;
23702 		cnt++;
23703 	}
23704 	/* TCP_SHARED_CWND_ENABLE */
23705 	if (dest->rack_enable_scwnd != src->rack_enable_scwnd) {
23706 		dest->rack_enable_scwnd = src->rack_enable_scwnd;
23707 		cnt++;
23708 	}
23709 	/* TCP_USE_CMP_ACKS */
23710 	if (dest->r_use_cmp_ack != src->r_use_cmp_ack) {
23711 		dest->r_use_cmp_ack = src->r_use_cmp_ack;
23712 		cnt++;
23713 	}
23714 
23715 	if (dest->r_mbuf_queue != src->r_mbuf_queue) {
23716 		dest->r_mbuf_queue = src->r_mbuf_queue;
23717 		cnt++;
23718 	}
23719 	/* TCP_RACK_MBUF_QUEUE */
23720 	if (dest->r_mbuf_queue != src->r_mbuf_queue) {
23721 		dest->r_mbuf_queue = src->r_mbuf_queue;
23722 		cnt++;
23723 	}
23724 	if  (dest->r_mbuf_queue || dest->rc_always_pace || dest->r_use_cmp_ack) {
23725 		tp->t_flags2 |= TF2_SUPPORTS_MBUFQ;
23726 	} else {
23727 		tp->t_flags2 &= ~TF2_SUPPORTS_MBUFQ;
23728 	}
23729 	if (dest->r_use_cmp_ack && TCPS_HAVEESTABLISHED(tp->t_state)) {
23730 		tp->t_flags2 |= TF2_MBUF_ACKCMP;
23731 	}
23732 	/* TCP_RACK_NONRXT_CFG_RATE */
23733 	if (dest->rack_rec_nonrxt_use_cr != src->rack_rec_nonrxt_use_cr) {
23734 		dest->rack_rec_nonrxt_use_cr = src->rack_rec_nonrxt_use_cr;
23735 		cnt++;
23736 	}
23737 	/* TCP_NO_PRR */
23738 	if (dest->rack_no_prr != src->rack_no_prr) {
23739 		dest->rack_no_prr = src->rack_no_prr;
23740 		cnt++;
23741 	}
23742 	if (dest->no_prr_addback != src->no_prr_addback) {
23743 		dest->no_prr_addback = src->no_prr_addback;
23744 		cnt++;
23745 	}
23746 	/* RACK_CSPR_IS_FCC */
23747 	if (dest->cspr_is_fcc != src->cspr_is_fcc) {
23748 		dest->cspr_is_fcc = src->cspr_is_fcc;
23749 		cnt++;
23750 	}
23751 	/* TCP_TIMELY_DYN_ADJ */
23752 	if (dest->rc_gp_dyn_mul != src->rc_gp_dyn_mul) {
23753 		dest->rc_gp_dyn_mul = src->rc_gp_dyn_mul;
23754 		cnt++;
23755 	}
23756 	if (dest->r_ctl.rack_per_of_gp_ca != src->r_ctl.rack_per_of_gp_ca) {
23757 		dest->r_ctl.rack_per_of_gp_ca = src->r_ctl.rack_per_of_gp_ca;
23758 		cnt++;
23759 	}
23760 	/* TCP_RACK_TLP_USE */
23761 	if (dest->rack_tlp_threshold_use != src->rack_tlp_threshold_use) {
23762 		dest->rack_tlp_threshold_use = src->rack_tlp_threshold_use;
23763 		cnt++;
23764 	}
23765 	/* we don't allow inheritence of TCP_RACK_PACE_ALWAYS */
23766 	/* TCP_BBR_RACK_INIT_RATE */
23767 	if (dest->r_ctl.init_rate != src->r_ctl.init_rate) {
23768 		dest->r_ctl.init_rate = src->r_ctl.init_rate;
23769 		cnt++;
23770 	}
23771 	/* TCP_RACK_FORCE_MSEG */
23772 	if (dest->rc_force_max_seg != src->rc_force_max_seg) {
23773 		dest->rc_force_max_seg = src->rc_force_max_seg;
23774 		cnt++;
23775 	}
23776 	/* TCP_RACK_PACE_MIN_SEG */
23777 	if (dest->r_ctl.rc_user_set_min_segs != src->r_ctl.rc_user_set_min_segs) {
23778 		dest->r_ctl.rc_user_set_min_segs = src->r_ctl.rc_user_set_min_segs;
23779 		cnt++;
23780 	}
23781 	/* we don't allow TCP_RACK_PACE_MAX_SEG */
23782 	/* TCP_RACK_PACE_RATE_REC, TCP_RACK_PACE_RATE_SS,  TCP_RACK_PACE_RATE_CA */
23783 	if (dest->r_ctl.rc_fixed_pacing_rate_ca != src->r_ctl.rc_fixed_pacing_rate_ca) {
23784 		dest->r_ctl.rc_fixed_pacing_rate_ca = src->r_ctl.rc_fixed_pacing_rate_ca;
23785 		cnt++;
23786 	}
23787 	if (dest->r_ctl.rc_fixed_pacing_rate_ss != src->r_ctl.rc_fixed_pacing_rate_ss) {
23788 		dest->r_ctl.rc_fixed_pacing_rate_ss = src->r_ctl.rc_fixed_pacing_rate_ss;
23789 		cnt++;
23790 	}
23791 	if (dest->r_ctl.rc_fixed_pacing_rate_rec != src->r_ctl.rc_fixed_pacing_rate_rec) {
23792 		dest->r_ctl.rc_fixed_pacing_rate_rec = src->r_ctl.rc_fixed_pacing_rate_rec;
23793 		cnt++;
23794 	}
23795 	/* TCP_RACK_GP_INCREASE_REC, TCP_RACK_GP_INCREASE_CA, TCP_RACK_GP_INCREASE_SS */
23796 	if (dest->r_ctl.rack_per_of_gp_rec != src->r_ctl.rack_per_of_gp_rec) {
23797 		dest->r_ctl.rack_per_of_gp_rec = src->r_ctl.rack_per_of_gp_rec;
23798 		cnt++;
23799 	}
23800 	if (dest->r_ctl.rack_per_of_gp_ca != src->r_ctl.rack_per_of_gp_ca) {
23801 		dest->r_ctl.rack_per_of_gp_ca = src->r_ctl.rack_per_of_gp_ca;
23802 		cnt++;
23803 	}
23804 
23805 	if (dest->r_ctl.rack_per_of_gp_ss != src->r_ctl.rack_per_of_gp_ss) {
23806 		dest->r_ctl.rack_per_of_gp_ss = src->r_ctl.rack_per_of_gp_ss;
23807 		cnt++;
23808 	}
23809 	/* TCP_RACK_RR_CONF */
23810 	if (dest->r_rr_config != src->r_rr_config) {
23811 		dest->r_rr_config = src->r_rr_config;
23812 		cnt++;
23813 	}
23814 	/* TCP_PACING_DND */
23815 	if (dest->rc_pace_dnd != src->rc_pace_dnd) {
23816 		dest->rc_pace_dnd = src->rc_pace_dnd;
23817 		cnt++;
23818 	}
23819 	/* TCP_HDWR_RATE_CAP */
23820 	if (dest->r_rack_hw_rate_caps != src->r_rack_hw_rate_caps) {
23821 		dest->r_rack_hw_rate_caps = src->r_rack_hw_rate_caps;
23822 		cnt++;
23823 	}
23824 	/* TCP_DGP_UPPER_BOUNDS */
23825 	if (dest->r_ctl.rack_per_upper_bound_ca != src->r_ctl.rack_per_upper_bound_ca) {
23826 		dest->r_ctl.rack_per_upper_bound_ca = src->r_ctl.rack_per_upper_bound_ca;
23827 		cnt++;
23828 	}
23829 	if (dest->r_ctl.rack_per_upper_bound_ss != src->r_ctl.rack_per_upper_bound_ss) {
23830 		dest->r_ctl.rack_per_upper_bound_ss = src->r_ctl.rack_per_upper_bound_ss;
23831 		cnt++;
23832 	}
23833 	/* TCP_SS_EEXIT */
23834 	if (dest->r_ctl.gp_rnd_thresh != src->r_ctl.gp_rnd_thresh) {
23835 		dest->r_ctl.gp_rnd_thresh = src->r_ctl.gp_rnd_thresh;
23836 		cnt++;
23837 	}
23838 	if (dest->r_ctl.gate_to_fs != src->r_ctl.gate_to_fs) {
23839 		dest->r_ctl.gate_to_fs = src->r_ctl.gate_to_fs;
23840 		cnt++;
23841 	}
23842 	if (dest->r_ctl.use_gp_not_last != src->r_ctl.use_gp_not_last) {
23843 		dest->r_ctl.use_gp_not_last = src->r_ctl.use_gp_not_last;
23844 		cnt++;
23845 	}
23846 	if (dest->r_ctl.gp_gain_req != src->r_ctl.gp_gain_req) {
23847 		dest->r_ctl.gp_gain_req = src->r_ctl.gp_gain_req;
23848 		cnt++;
23849 	}
23850 	/* TCP_BBR_HDWR_PACE */
23851 	if (dest->rack_hdw_pace_ena != src->rack_hdw_pace_ena) {
23852 		dest->rack_hdw_pace_ena = src->rack_hdw_pace_ena;
23853 		cnt++;
23854 	}
23855 	if (dest->rack_attempt_hdwr_pace != src->rack_attempt_hdwr_pace) {
23856 		dest->rack_attempt_hdwr_pace = src->rack_attempt_hdwr_pace;
23857 		cnt++;
23858 	}
23859 	/* TCP_RACK_PRR_SENDALOT */
23860 	if (dest->r_ctl.rc_prr_sendalot != src->r_ctl.rc_prr_sendalot) {
23861 		dest->r_ctl.rc_prr_sendalot = src->r_ctl.rc_prr_sendalot;
23862 		cnt++;
23863 	}
23864 	/* TCP_RACK_MIN_TO */
23865 	if (dest->r_ctl.rc_min_to != src->r_ctl.rc_min_to) {
23866 		dest->r_ctl.rc_min_to = src->r_ctl.rc_min_to;
23867 		cnt++;
23868 	}
23869 	/* TCP_RACK_EARLY_SEG */
23870 	if (dest->r_ctl.rc_early_recovery_segs != src->r_ctl.rc_early_recovery_segs) {
23871 		dest->r_ctl.rc_early_recovery_segs = src->r_ctl.rc_early_recovery_segs;
23872 		cnt++;
23873 	}
23874 	/* TCP_RACK_ENABLE_HYSTART */
23875 	if (par->t_ccv.flags != tp->t_ccv.flags) {
23876 		cnt++;
23877 		if (par->t_ccv.flags & CCF_HYSTART_ALLOWED) {
23878 			tp->t_ccv.flags |= CCF_HYSTART_ALLOWED;
23879 			if (rack_do_hystart > RACK_HYSTART_ON)
23880 				tp->t_ccv.flags |= CCF_HYSTART_CAN_SH_CWND;
23881 			if (rack_do_hystart > RACK_HYSTART_ON_W_SC)
23882 				tp->t_ccv.flags |= CCF_HYSTART_CONS_SSTH;
23883 		} else {
23884 			tp->t_ccv.flags &= ~(CCF_HYSTART_ALLOWED|CCF_HYSTART_CAN_SH_CWND|CCF_HYSTART_CONS_SSTH);
23885 		}
23886 	}
23887 	/* TCP_RACK_REORD_THRESH */
23888 	if (dest->r_ctl.rc_reorder_shift != src->r_ctl.rc_reorder_shift) {
23889 		dest->r_ctl.rc_reorder_shift = src->r_ctl.rc_reorder_shift;
23890 		cnt++;
23891 	}
23892 	/* TCP_RACK_REORD_FADE */
23893 	if (dest->r_ctl.rc_reorder_fade != src->r_ctl.rc_reorder_fade) {
23894 		dest->r_ctl.rc_reorder_fade = src->r_ctl.rc_reorder_fade;
23895 		cnt++;
23896 	}
23897 	/* TCP_RACK_TLP_THRESH */
23898 	if (dest->r_ctl.rc_tlp_threshold != src->r_ctl.rc_tlp_threshold) {
23899 		dest->r_ctl.rc_tlp_threshold = src->r_ctl.rc_tlp_threshold;
23900 		cnt++;
23901 	}
23902 	/* TCP_BBR_USE_RACK_RR */
23903 	if (dest->use_rack_rr != src->use_rack_rr) {
23904 		dest->use_rack_rr = src->use_rack_rr;
23905 		cnt++;
23906 	}
23907 	/* TCP_RACK_PKT_DELAY */
23908 	if (dest->r_ctl.rc_pkt_delay != src->r_ctl.rc_pkt_delay) {
23909 		dest->r_ctl.rc_pkt_delay = src->r_ctl.rc_pkt_delay;
23910 		cnt++;
23911 	}
23912 	/* TCP_DELACK will get copied via the main code if applicable */
23913 	/* TCP_BBR_RACK_RTT_USE */
23914 	if (dest->r_ctl.rc_rate_sample_method != src->r_ctl.rc_rate_sample_method) {
23915 		dest->r_ctl.rc_rate_sample_method = src->r_ctl.rc_rate_sample_method;
23916 		cnt++;
23917 	}
23918 	/* TCP_HONOR_HPTS_MIN */
23919 	if (dest->r_use_hpts_min != src->r_use_hpts_min) {
23920 		dest->r_use_hpts_min = src->r_use_hpts_min;
23921 		cnt++;
23922 	}
23923 	if (dest->r_ctl.max_reduction != src->r_ctl.max_reduction) {
23924 		dest->r_ctl.max_reduction = src->r_ctl.max_reduction;
23925 		cnt++;
23926 	}
23927 	/* TCP_REC_IS_DYN */
23928 	if (dest->rc_gp_no_rec_chg != src->rc_gp_no_rec_chg) {
23929 		dest->rc_gp_no_rec_chg = src->rc_gp_no_rec_chg;
23930 		cnt++;
23931 	}
23932 	if (dest->rc_skip_timely != src->rc_skip_timely) {
23933 		dest->rc_skip_timely = src->rc_skip_timely;
23934 		cnt++;
23935 	}
23936 	/* TCP_DATA_AFTER_CLOSE */
23937 	if (dest->rc_allow_data_af_clo != src->rc_allow_data_af_clo) {
23938 		dest->rc_allow_data_af_clo = src->rc_allow_data_af_clo;
23939 		cnt++;
23940 	}
23941 	/* TCP_GP_USE_LTBW */
23942 	if (src->use_lesser_lt_bw != dest->use_lesser_lt_bw) {
23943 		dest->use_lesser_lt_bw = src->use_lesser_lt_bw;
23944 		cnt++;
23945 	}
23946 	if (dest->dis_lt_bw != src->dis_lt_bw) {
23947 		dest->dis_lt_bw = src->dis_lt_bw;
23948 		cnt++;
23949 	}
23950 	tcp_log_socket_option(tp, 0, cnt, 0);
23951 }
23952 
23953 
23954 static void
23955 rack_apply_deferred_options(struct tcp_rack *rack)
23956 {
23957 	struct deferred_opt_list *dol, *sdol;
23958 	uint32_t s_optval;
23959 
23960 	TAILQ_FOREACH_SAFE(dol, &rack->r_ctl.opt_list, next, sdol) {
23961 		TAILQ_REMOVE(&rack->r_ctl.opt_list, dol, next);
23962 		/* Disadvantage of deferal is you loose the error return */
23963 		s_optval = (uint32_t)dol->optval;
23964 		(void)rack_process_option(rack->rc_tp, rack, dol->optname, s_optval, dol->optval, NULL);
23965 		free(dol, M_TCPDO);
23966 	}
23967 }
23968 
23969 static void
23970 rack_hw_tls_change(struct tcpcb *tp, int chg)
23971 {
23972 	/* Update HW tls state */
23973 	struct tcp_rack *rack;
23974 
23975 	rack = (struct tcp_rack *)tp->t_fb_ptr;
23976 	if (chg)
23977 		rack->r_ctl.fsb.hw_tls = 1;
23978 	else
23979 		rack->r_ctl.fsb.hw_tls = 0;
23980 }
23981 
23982 static int
23983 rack_pru_options(struct tcpcb *tp, int flags)
23984 {
23985 	if (flags & PRUS_OOB)
23986 		return (EOPNOTSUPP);
23987 	return (0);
23988 }
23989 
23990 static bool
23991 rack_wake_check(struct tcpcb *tp)
23992 {
23993 	struct tcp_rack *rack;
23994 	struct timeval tv;
23995 	uint32_t cts;
23996 
23997 	rack = (struct tcp_rack *)tp->t_fb_ptr;
23998 	if (rack->r_ctl.rc_hpts_flags) {
23999 		cts = tcp_get_usecs(&tv);
24000 		if ((rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT) == PACE_PKT_OUTPUT){
24001 			/*
24002 			 * Pacing timer is up, check if we are ready.
24003 			 */
24004 			if (TSTMP_GEQ(cts, rack->r_ctl.rc_last_output_to))
24005 				return (true);
24006 		} else if ((rack->r_ctl.rc_hpts_flags & PACE_TMR_MASK) != 0) {
24007 			/*
24008 			 * A timer is up, check if we are ready.
24009 			 */
24010 			if (TSTMP_GEQ(cts, rack->r_ctl.rc_timer_exp))
24011 				return (true);
24012 		}
24013 	}
24014 	return (false);
24015 }
24016 
24017 static struct tcp_function_block __tcp_rack = {
24018 	.tfb_tcp_block_name = __XSTRING(STACKNAME),
24019 	.tfb_tcp_output = rack_output,
24020 	.tfb_do_queued_segments = ctf_do_queued_segments,
24021 	.tfb_do_segment_nounlock = rack_do_segment_nounlock,
24022 	.tfb_tcp_do_segment = rack_do_segment,
24023 	.tfb_tcp_ctloutput = rack_ctloutput,
24024 	.tfb_tcp_fb_init = rack_init,
24025 	.tfb_tcp_fb_fini = rack_fini,
24026 	.tfb_tcp_timer_stop_all = rack_stopall,
24027 	.tfb_tcp_rexmit_tmr = rack_remxt_tmr,
24028 	.tfb_tcp_handoff_ok = rack_handoff_ok,
24029 	.tfb_tcp_mtu_chg = rack_mtu_change,
24030 	.tfb_pru_options = rack_pru_options,
24031 	.tfb_hwtls_change = rack_hw_tls_change,
24032 	.tfb_chg_query = rack_chg_query,
24033 	.tfb_switch_failed = rack_switch_failed,
24034 	.tfb_early_wake_check = rack_wake_check,
24035 	.tfb_compute_pipe = rack_compute_pipe,
24036 	.tfb_stack_info = rack_stack_information,
24037 	.tfb_inherit = rack_inherit,
24038 	.tfb_flags = TCP_FUNC_OUTPUT_CANDROP | TCP_FUNC_DEFAULT_OK,
24039 
24040 };
24041 
24042 /*
24043  * rack_ctloutput() must drop the inpcb lock before performing copyin on
24044  * socket option arguments.  When it re-acquires the lock after the copy, it
24045  * has to revalidate that the connection is still valid for the socket
24046  * option.
24047  */
24048 static int
24049 rack_set_sockopt(struct tcpcb *tp, struct sockopt *sopt)
24050 {
24051 	struct inpcb *inp = tptoinpcb(tp);
24052 #ifdef INET
24053 	struct ip *ip;
24054 #endif
24055 	struct tcp_rack *rack;
24056 	struct tcp_hybrid_req hybrid;
24057 	uint64_t loptval;
24058 	int32_t error = 0, optval;
24059 
24060 	rack = (struct tcp_rack *)tp->t_fb_ptr;
24061 	if (rack == NULL) {
24062 		INP_WUNLOCK(inp);
24063 		return (EINVAL);
24064 	}
24065 #ifdef INET
24066 	ip = (struct ip *)rack->r_ctl.fsb.tcp_ip_hdr;
24067 #endif
24068 
24069 	switch (sopt->sopt_level) {
24070 #ifdef INET6
24071 	case IPPROTO_IPV6:
24072 		MPASS(inp->inp_vflag & INP_IPV6PROTO);
24073 		switch (sopt->sopt_name) {
24074 		case IPV6_USE_MIN_MTU:
24075 			tcp6_use_min_mtu(tp);
24076 			break;
24077 		}
24078 		INP_WUNLOCK(inp);
24079 		return (0);
24080 #endif
24081 #ifdef INET
24082 	case IPPROTO_IP:
24083 		switch (sopt->sopt_name) {
24084 		case IP_TOS:
24085 			/*
24086 			 * The DSCP codepoint has changed, update the fsb.
24087 			 */
24088 			ip->ip_tos = rack->rc_inp->inp_ip_tos;
24089 			break;
24090 		case IP_TTL:
24091 			/*
24092 			 * The TTL has changed, update the fsb.
24093 			 */
24094 			ip->ip_ttl = rack->rc_inp->inp_ip_ttl;
24095 			break;
24096 		}
24097 		INP_WUNLOCK(inp);
24098 		return (0);
24099 #endif
24100 #ifdef SO_PEERPRIO
24101 	case SOL_SOCKET:
24102 		switch (sopt->sopt_name) {
24103 		case SO_PEERPRIO:			/*  SC-URL:bs */
24104 			/* Already read in and sanity checked in sosetopt(). */
24105 			if (inp->inp_socket) {
24106 				rack->client_bufferlvl = inp->inp_socket->so_peerprio;
24107 			}
24108 			break;
24109 		}
24110 		INP_WUNLOCK(inp);
24111 		return (0);
24112 #endif
24113 	case IPPROTO_TCP:
24114 		switch (sopt->sopt_name) {
24115 		case TCP_RACK_TLP_REDUCE:		/*  URL:tlp_reduce */
24116 		/*  Pacing related ones */
24117 		case TCP_RACK_PACE_ALWAYS:		/*  URL:pace_always */
24118 		case TCP_BBR_RACK_INIT_RATE:		/*  URL:irate */
24119 		case TCP_RACK_PACE_MIN_SEG:		/*  URL:pace_min_seg */
24120 		case TCP_RACK_PACE_MAX_SEG:		/*  URL:pace_max_seg */
24121 		case TCP_RACK_FORCE_MSEG:		/*  URL:force_max_seg */
24122 		case TCP_RACK_PACE_RATE_CA:		/*  URL:pr_ca */
24123 		case TCP_RACK_PACE_RATE_SS:		/*  URL:pr_ss*/
24124 		case TCP_RACK_PACE_RATE_REC:		/*  URL:pr_rec */
24125 		case TCP_RACK_GP_INCREASE_CA:		/*  URL:gp_inc_ca */
24126 		case TCP_RACK_GP_INCREASE_SS:		/*  URL:gp_inc_ss */
24127 		case TCP_RACK_GP_INCREASE_REC:		/*  URL:gp_inc_rec */
24128 		case TCP_RACK_RR_CONF:			/*  URL:rrr_conf */
24129 		case TCP_BBR_HDWR_PACE:			/*  URL:hdwrpace */
24130 		case TCP_HDWR_RATE_CAP:			/*  URL:hdwrcap boolean */
24131 		case TCP_PACING_RATE_CAP:		/*  URL:cap  -- used by side-channel */
24132 		case TCP_HDWR_UP_ONLY:			/*  URL:uponly -- hardware pacing  boolean */
24133 		case TCP_FILLCW_RATE_CAP:		/*  URL:fillcw_cap */
24134 		case TCP_RACK_PACING_BETA_ECN:		/*  URL:pacing_beta_ecn */
24135 		case TCP_RACK_PACE_TO_FILL:		/*  URL:fillcw */
24136 			/* End pacing related */
24137 		case TCP_DELACK:			/*  URL:delack (in base TCP i.e. tcp_hints along with cc etc ) */
24138 		case TCP_RACK_PRR_SENDALOT:		/*  URL:prr_sendalot */
24139 		case TCP_RACK_MIN_TO:			/*  URL:min_to */
24140 		case TCP_RACK_EARLY_SEG:		/*  URL:early_seg */
24141 		case TCP_RACK_REORD_THRESH:		/*  URL:reord_thresh */
24142 		case TCP_RACK_REORD_FADE:		/*  URL:reord_fade */
24143 		case TCP_RACK_TLP_THRESH:		/*  URL:tlp_thresh */
24144 		case TCP_RACK_PKT_DELAY:		/*  URL:pkt_delay */
24145 		case TCP_RACK_TLP_USE:			/*  URL:tlp_use */
24146 		case TCP_BBR_RACK_RTT_USE:		/*  URL:rttuse */
24147 		case TCP_BBR_USE_RACK_RR:		/*  URL:rackrr */
24148 		case TCP_NO_PRR:			/*  URL:noprr */
24149 		case TCP_TIMELY_DYN_ADJ:      		/*  URL:dynamic */
24150 		case TCP_DATA_AFTER_CLOSE:		/*  no URL */
24151 		case TCP_RACK_NONRXT_CFG_RATE:		/*  URL:nonrxtcr */
24152 		case TCP_SHARED_CWND_ENABLE:		/*  URL:scwnd */
24153 		case TCP_RACK_MBUF_QUEUE:		/*  URL:mqueue */
24154 		case TCP_RACK_NO_PUSH_AT_MAX:		/*  URL:npush */
24155 		case TCP_SHARED_CWND_TIME_LIMIT:	/*  URL:lscwnd */
24156 		case TCP_RACK_PROFILE:			/*  URL:profile */
24157 		case TCP_SIDECHAN_DIS:			/*  URL:scodm */
24158 		case TCP_HYBRID_PACING:			/*  URL:pacing=hybrid */
24159 		case TCP_USE_CMP_ACKS:			/*  URL:cmpack */
24160 		case TCP_RACK_ABC_VAL:			/*  URL:labc */
24161 		case TCP_REC_ABC_VAL:			/*  URL:reclabc */
24162 		case TCP_RACK_MEASURE_CNT:		/*  URL:measurecnt */
24163 		case TCP_DEFER_OPTIONS:			/*  URL:defer */
24164 		case TCP_RACK_DSACK_OPT:		/*  URL:dsack */
24165 		case TCP_RACK_TIMER_SLOP:		/*  URL:timer_slop */
24166 		case TCP_RACK_ENABLE_HYSTART:		/*  URL:hystart */
24167 		case TCP_RACK_SET_RXT_OPTIONS:		/*  URL:rxtsz */
24168 		case TCP_RACK_HI_BETA:			/*  URL:hibeta */
24169 		case TCP_RACK_SPLIT_LIMIT:		/*  URL:split */
24170 		case TCP_SS_EEXIT:			/*  URL:eexit */
24171 		case TCP_DGP_UPPER_BOUNDS:		/*  URL:upper */
24172 		case TCP_RACK_PACING_DIVISOR:		/*  URL:divisor */
24173 		case TCP_PACING_DND:			/*  URL:dnd */
24174 		case TCP_NO_TIMELY:			/*  URL:notimely */
24175 		case RACK_CSPR_IS_FCC:			/*  URL:csprisfcc */
24176 		case TCP_HONOR_HPTS_MIN:		/*  URL:hptsmin */
24177 		case TCP_REC_IS_DYN:			/*  URL:dynrec */
24178 		case TCP_GP_USE_LTBW:			/*  URL:useltbw */
24179 			goto process_opt;
24180 			break;
24181 		default:
24182 			/* Filter off all unknown options to the base stack */
24183 			return (tcp_default_ctloutput(tp, sopt));
24184 			break;
24185 		}
24186 	default:
24187 		INP_WUNLOCK(inp);
24188 		return (0);
24189 	}
24190 process_opt:
24191 	INP_WUNLOCK(inp);
24192 	if ((sopt->sopt_name == TCP_PACING_RATE_CAP) ||
24193 	    (sopt->sopt_name == TCP_FILLCW_RATE_CAP)) {
24194 		error = sooptcopyin(sopt, &loptval, sizeof(loptval), sizeof(loptval));
24195 		/*
24196 		 * We truncate it down to 32 bits for the socket-option trace this
24197 		 * means rates > 34Gbps won't show right, but thats probably ok.
24198 		 */
24199 		optval = (uint32_t)loptval;
24200 	} else if (sopt->sopt_name == TCP_HYBRID_PACING) {
24201 		error = sooptcopyin(sopt, &hybrid, sizeof(hybrid), sizeof(hybrid));
24202 	} else {
24203 		error = sooptcopyin(sopt, &optval, sizeof(optval), sizeof(optval));
24204 		/* Save it in 64 bit form too */
24205 		loptval = optval;
24206 	}
24207 	if (error)
24208 		return (error);
24209 	INP_WLOCK(inp);
24210 	if (tp->t_fb != &__tcp_rack) {
24211 		INP_WUNLOCK(inp);
24212 		return (ENOPROTOOPT);
24213 	}
24214 	if (rack->defer_options && (rack->gp_ready == 0) &&
24215 	    (sopt->sopt_name != TCP_DEFER_OPTIONS) &&
24216 	    (sopt->sopt_name != TCP_HYBRID_PACING) &&
24217 	    (sopt->sopt_name != TCP_RACK_SET_RXT_OPTIONS) &&
24218 	    (sopt->sopt_name != TCP_RACK_PACING_BETA_ECN) &&
24219 	    (sopt->sopt_name != TCP_RACK_MEASURE_CNT)) {
24220 		/* Options are being deferred */
24221 		if (rack_add_deferred_option(rack, sopt->sopt_name, loptval)) {
24222 			INP_WUNLOCK(inp);
24223 			return (0);
24224 		} else {
24225 			/* No memory to defer, fail */
24226 			INP_WUNLOCK(inp);
24227 			return (ENOMEM);
24228 		}
24229 	}
24230 	error = rack_process_option(tp, rack, sopt->sopt_name, optval, loptval, &hybrid);
24231 	INP_WUNLOCK(inp);
24232 	return (error);
24233 }
24234 
24235 static void
24236 rack_fill_info(struct tcpcb *tp, struct tcp_info *ti)
24237 {
24238 
24239 	INP_WLOCK_ASSERT(tptoinpcb(tp));
24240 	bzero(ti, sizeof(*ti));
24241 
24242 	ti->tcpi_state = tp->t_state;
24243 	if ((tp->t_flags & TF_REQ_TSTMP) && (tp->t_flags & TF_RCVD_TSTMP))
24244 		ti->tcpi_options |= TCPI_OPT_TIMESTAMPS;
24245 	if (tp->t_flags & TF_SACK_PERMIT)
24246 		ti->tcpi_options |= TCPI_OPT_SACK;
24247 	if ((tp->t_flags & TF_REQ_SCALE) && (tp->t_flags & TF_RCVD_SCALE)) {
24248 		ti->tcpi_options |= TCPI_OPT_WSCALE;
24249 		ti->tcpi_snd_wscale = tp->snd_scale;
24250 		ti->tcpi_rcv_wscale = tp->rcv_scale;
24251 	}
24252 	if (tp->t_flags2 & (TF2_ECN_PERMIT | TF2_ACE_PERMIT))
24253 		ti->tcpi_options |= TCPI_OPT_ECN;
24254 	if (tp->t_flags & TF_FASTOPEN)
24255 		ti->tcpi_options |= TCPI_OPT_TFO;
24256 	/* still kept in ticks is t_rcvtime */
24257 	ti->tcpi_last_data_recv = ((uint32_t)ticks - tp->t_rcvtime) * tick;
24258 	/* Since we hold everything in precise useconds this is easy */
24259 	ti->tcpi_rtt = tp->t_srtt;
24260 	ti->tcpi_rttvar = tp->t_rttvar;
24261 	ti->tcpi_rto = tp->t_rxtcur;
24262 	ti->tcpi_snd_ssthresh = tp->snd_ssthresh;
24263 	ti->tcpi_snd_cwnd = tp->snd_cwnd;
24264 	/*
24265 	 * FreeBSD-specific extension fields for tcp_info.
24266 	 */
24267 	ti->tcpi_rcv_space = tp->rcv_wnd;
24268 	ti->tcpi_rcv_nxt = tp->rcv_nxt;
24269 	ti->tcpi_snd_wnd = tp->snd_wnd;
24270 	ti->tcpi_snd_bwnd = 0;		/* Unused, kept for compat. */
24271 	ti->tcpi_snd_nxt = tp->snd_nxt;
24272 	ti->tcpi_snd_mss = tp->t_maxseg;
24273 	ti->tcpi_rcv_mss = tp->t_maxseg;
24274 	ti->tcpi_snd_rexmitpack = tp->t_sndrexmitpack;
24275 	ti->tcpi_rcv_ooopack = tp->t_rcvoopack;
24276 	ti->tcpi_snd_zerowin = tp->t_sndzerowin;
24277 	ti->tcpi_total_tlp = tp->t_sndtlppack;
24278 	ti->tcpi_total_tlp_bytes = tp->t_sndtlpbyte;
24279 	ti->tcpi_rttmin = tp->t_rttlow;
24280 #ifdef NETFLIX_STATS
24281 	memcpy(&ti->tcpi_rxsyninfo, &tp->t_rxsyninfo, sizeof(struct tcpsyninfo));
24282 #endif
24283 #ifdef TCP_OFFLOAD
24284 	if (tp->t_flags & TF_TOE) {
24285 		ti->tcpi_options |= TCPI_OPT_TOE;
24286 		tcp_offload_tcp_info(tp, ti);
24287 	}
24288 #endif
24289 }
24290 
24291 static int
24292 rack_get_sockopt(struct tcpcb *tp, struct sockopt *sopt)
24293 {
24294 	struct inpcb *inp = tptoinpcb(tp);
24295 	struct tcp_rack *rack;
24296 	int32_t error, optval;
24297 	uint64_t val, loptval;
24298 	struct	tcp_info ti;
24299 	/*
24300 	 * Because all our options are either boolean or an int, we can just
24301 	 * pull everything into optval and then unlock and copy. If we ever
24302 	 * add a option that is not a int, then this will have quite an
24303 	 * impact to this routine.
24304 	 */
24305 	error = 0;
24306 	rack = (struct tcp_rack *)tp->t_fb_ptr;
24307 	if (rack == NULL) {
24308 		INP_WUNLOCK(inp);
24309 		return (EINVAL);
24310 	}
24311 	switch (sopt->sopt_name) {
24312 	case TCP_INFO:
24313 		/* First get the info filled */
24314 		rack_fill_info(tp, &ti);
24315 		/* Fix up the rtt related fields if needed */
24316 		INP_WUNLOCK(inp);
24317 		error = sooptcopyout(sopt, &ti, sizeof ti);
24318 		return (error);
24319 	/*
24320 	 * Beta is the congestion control value for NewReno that influences how
24321 	 * much of a backoff happens when loss is detected. It is normally set
24322 	 * to 50 for 50% i.e. the cwnd is reduced to 50% of its previous value
24323 	 * when you exit recovery.
24324 	 */
24325 	case TCP_RACK_PACING_BETA:
24326 		if (strcmp(tp->t_cc->name, CCALGONAME_NEWRENO) != 0)
24327 			error = EINVAL;
24328 		else if (rack->rc_pacing_cc_set == 0)
24329 			optval = rack->r_ctl.rc_saved_beta;
24330 		else {
24331 			/*
24332 			 * Reach out into the CC data and report back what
24333 			 * I have previously set. Yeah it looks hackish but
24334 			 * we don't want to report the saved values.
24335 			 */
24336 			if (tp->t_ccv.cc_data)
24337 				optval = ((struct newreno *)tp->t_ccv.cc_data)->beta;
24338 			else
24339 				error = EINVAL;
24340 		}
24341 		break;
24342 	/*
24343 	 * Beta_ecn is the congestion control value for NewReno that influences how
24344 	 * much of a backoff happens when a ECN mark is detected. It is normally set
24345 	 * to 80 for 80% i.e. the cwnd is reduced by 20% of its previous value when
24346 	 * you exit recovery. Note that classic ECN has a beta of 50, it is only
24347 	 * ABE Ecn that uses this "less" value, but we do too with pacing :)
24348 	 */
24349 	case TCP_RACK_PACING_BETA_ECN:
24350 		if (strcmp(tp->t_cc->name, CCALGONAME_NEWRENO) != 0)
24351 			error = EINVAL;
24352 		else if (rack->rc_pacing_cc_set == 0)
24353 			optval = rack->r_ctl.rc_saved_beta_ecn;
24354 		else {
24355 			/*
24356 			 * Reach out into the CC data and report back what
24357 			 * I have previously set. Yeah it looks hackish but
24358 			 * we don't want to report the saved values.
24359 			 */
24360 			if (tp->t_ccv.cc_data)
24361 				optval = ((struct newreno *)tp->t_ccv.cc_data)->beta_ecn;
24362 			else
24363 				error = EINVAL;
24364 		}
24365 		break;
24366 	case TCP_RACK_DSACK_OPT:
24367 		optval = 0;
24368 		if (rack->rc_rack_tmr_std_based) {
24369 			optval |= 1;
24370 		}
24371 		if (rack->rc_rack_use_dsack) {
24372 			optval |= 2;
24373 		}
24374 		break;
24375 	case TCP_RACK_ENABLE_HYSTART:
24376 	{
24377 		if (tp->t_ccv.flags & CCF_HYSTART_ALLOWED) {
24378 			optval = RACK_HYSTART_ON;
24379 			if (tp->t_ccv.flags & CCF_HYSTART_CAN_SH_CWND)
24380 				optval = RACK_HYSTART_ON_W_SC;
24381 			if (tp->t_ccv.flags & CCF_HYSTART_CONS_SSTH)
24382 				optval = RACK_HYSTART_ON_W_SC_C;
24383 		} else {
24384 			optval = RACK_HYSTART_OFF;
24385 		}
24386 	}
24387 	break;
24388 	case TCP_RACK_DGP_IN_REC:
24389 		error = EINVAL;
24390 		break;
24391 	case TCP_RACK_HI_BETA:
24392 		optval = rack->rack_hibeta;
24393 		break;
24394 	case TCP_DEFER_OPTIONS:
24395 		optval = rack->defer_options;
24396 		break;
24397 	case TCP_RACK_MEASURE_CNT:
24398 		optval = rack->r_ctl.req_measurements;
24399 		break;
24400 	case TCP_REC_ABC_VAL:
24401 		optval = rack->r_use_labc_for_rec;
24402 		break;
24403 	case TCP_RACK_ABC_VAL:
24404 		optval = rack->rc_labc;
24405 		break;
24406 	case TCP_HDWR_UP_ONLY:
24407 		optval= rack->r_up_only;
24408 		break;
24409 	case TCP_FILLCW_RATE_CAP:
24410 		loptval = rack->r_ctl.fillcw_cap;
24411 		break;
24412 	case TCP_PACING_RATE_CAP:
24413 		loptval = rack->r_ctl.bw_rate_cap;
24414 		break;
24415 	case TCP_RACK_PROFILE:
24416 		/* You cannot retrieve a profile, its write only */
24417 		error = EINVAL;
24418 		break;
24419 	case TCP_SIDECHAN_DIS:
24420 		optval = rack->r_ctl.side_chan_dis_mask;
24421 		break;
24422 	case TCP_HYBRID_PACING:
24423 		/* You cannot retrieve hybrid pacing information, its write only */
24424 		error = EINVAL;
24425 		break;
24426 	case TCP_USE_CMP_ACKS:
24427 		optval = rack->r_use_cmp_ack;
24428 		break;
24429 	case TCP_RACK_PACE_TO_FILL:
24430 		optval = rack->rc_pace_to_cwnd;
24431 		break;
24432 	case TCP_RACK_NO_PUSH_AT_MAX:
24433 		optval = rack->r_ctl.rc_no_push_at_mrtt;
24434 		break;
24435 	case TCP_SHARED_CWND_ENABLE:
24436 		optval = rack->rack_enable_scwnd;
24437 		break;
24438 	case TCP_RACK_NONRXT_CFG_RATE:
24439 		optval = rack->rack_rec_nonrxt_use_cr;
24440 		break;
24441 	case TCP_NO_PRR:
24442 		if (rack->rack_no_prr  == 1)
24443 			optval = 1;
24444 		else if (rack->no_prr_addback == 1)
24445 			optval = 2;
24446 		else
24447 			optval = 0;
24448 		break;
24449 	case TCP_GP_USE_LTBW:
24450 		if (rack->dis_lt_bw) {
24451 			/* It is not used */
24452 			optval = 0;
24453 		} else if (rack->use_lesser_lt_bw) {
24454 			/* we use min() */
24455 			optval = 1;
24456 		} else {
24457 			/* we use max() */
24458 			optval = 2;
24459 		}
24460 		break;
24461 	case TCP_RACK_DO_DETECTION:
24462 		error = EINVAL;
24463 		break;
24464 	case TCP_RACK_MBUF_QUEUE:
24465 		/* Now do we use the LRO mbuf-queue feature */
24466 		optval = rack->r_mbuf_queue;
24467 		break;
24468 	case RACK_CSPR_IS_FCC:
24469 		optval = rack->cspr_is_fcc;
24470 		break;
24471 	case TCP_TIMELY_DYN_ADJ:
24472 		optval = rack->rc_gp_dyn_mul;
24473 		break;
24474 	case TCP_BBR_IWINTSO:
24475 		error = EINVAL;
24476 		break;
24477 	case TCP_RACK_TLP_REDUCE:
24478 		/* RACK TLP cwnd reduction (bool) */
24479 		optval = rack->r_ctl.rc_tlp_cwnd_reduce;
24480 		break;
24481 	case TCP_BBR_RACK_INIT_RATE:
24482 		val = rack->r_ctl.init_rate;
24483 		/* convert to kbits per sec */
24484 		val *= 8;
24485 		val /= 1000;
24486 		optval = (uint32_t)val;
24487 		break;
24488 	case TCP_RACK_FORCE_MSEG:
24489 		optval = rack->rc_force_max_seg;
24490 		break;
24491 	case TCP_RACK_PACE_MIN_SEG:
24492 		optval = rack->r_ctl.rc_user_set_min_segs;
24493 		break;
24494 	case TCP_RACK_PACE_MAX_SEG:
24495 		/* Max segments in a pace */
24496 		optval = rack->rc_user_set_max_segs;
24497 		break;
24498 	case TCP_RACK_PACE_ALWAYS:
24499 		/* Use the always pace method */
24500 		optval = rack->rc_always_pace;
24501 		break;
24502 	case TCP_RACK_PRR_SENDALOT:
24503 		/* Allow PRR to send more than one seg */
24504 		optval = rack->r_ctl.rc_prr_sendalot;
24505 		break;
24506 	case TCP_RACK_MIN_TO:
24507 		/* Minimum time between rack t-o's in ms */
24508 		optval = rack->r_ctl.rc_min_to;
24509 		break;
24510 	case TCP_RACK_SPLIT_LIMIT:
24511 		optval = rack->r_ctl.rc_split_limit;
24512 		break;
24513 	case TCP_RACK_EARLY_SEG:
24514 		/* If early recovery max segments */
24515 		optval = rack->r_ctl.rc_early_recovery_segs;
24516 		break;
24517 	case TCP_RACK_REORD_THRESH:
24518 		/* RACK reorder threshold (shift amount) */
24519 		optval = rack->r_ctl.rc_reorder_shift;
24520 		break;
24521 	case TCP_SS_EEXIT:
24522 		if (rack->r_ctl.gp_rnd_thresh) {
24523 			uint32_t v;
24524 
24525 			v = rack->r_ctl.gp_gain_req;
24526 			v <<= 17;
24527 			optval = v | (rack->r_ctl.gp_rnd_thresh & 0xff);
24528 			if (rack->r_ctl.gate_to_fs == 1)
24529 				optval |= 0x10000;
24530 		} else
24531 			optval = 0;
24532 		break;
24533 	case TCP_RACK_REORD_FADE:
24534 		/* Does reordering fade after ms time */
24535 		optval = rack->r_ctl.rc_reorder_fade;
24536 		break;
24537 	case TCP_BBR_USE_RACK_RR:
24538 		/* Do we use the rack cheat for rxt */
24539 		optval = rack->use_rack_rr;
24540 		break;
24541 	case TCP_RACK_RR_CONF:
24542 		optval = rack->r_rr_config;
24543 		break;
24544 	case TCP_HDWR_RATE_CAP:
24545 		optval = rack->r_rack_hw_rate_caps;
24546 		break;
24547 	case TCP_BBR_HDWR_PACE:
24548 		optval = rack->rack_hdw_pace_ena;
24549 		break;
24550 	case TCP_RACK_TLP_THRESH:
24551 		/* RACK TLP theshold i.e. srtt+(srtt/N) */
24552 		optval = rack->r_ctl.rc_tlp_threshold;
24553 		break;
24554 	case TCP_RACK_PKT_DELAY:
24555 		/* RACK added ms i.e. rack-rtt + reord + N */
24556 		optval = rack->r_ctl.rc_pkt_delay;
24557 		break;
24558 	case TCP_RACK_TLP_USE:
24559 		optval = rack->rack_tlp_threshold_use;
24560 		break;
24561 	case TCP_PACING_DND:
24562 		optval = rack->rc_pace_dnd;
24563 		break;
24564 	case TCP_RACK_PACE_RATE_CA:
24565 		optval = rack->r_ctl.rc_fixed_pacing_rate_ca;
24566 		break;
24567 	case TCP_RACK_PACE_RATE_SS:
24568 		optval = rack->r_ctl.rc_fixed_pacing_rate_ss;
24569 		break;
24570 	case TCP_RACK_PACE_RATE_REC:
24571 		optval = rack->r_ctl.rc_fixed_pacing_rate_rec;
24572 		break;
24573 	case TCP_DGP_UPPER_BOUNDS:
24574 		optval = rack->r_ctl.rack_per_upper_bound_ss;
24575 		optval <<= 16;
24576 		optval |= rack->r_ctl.rack_per_upper_bound_ca;
24577 		break;
24578 	case TCP_RACK_GP_INCREASE_SS:
24579 		optval = rack->r_ctl.rack_per_of_gp_ca;
24580 		break;
24581 	case TCP_RACK_GP_INCREASE_CA:
24582 		optval = rack->r_ctl.rack_per_of_gp_ss;
24583 		break;
24584 	case TCP_RACK_PACING_DIVISOR:
24585 		optval = rack->r_ctl.pace_len_divisor;
24586 		break;
24587 	case TCP_BBR_RACK_RTT_USE:
24588 		optval = rack->r_ctl.rc_rate_sample_method;
24589 		break;
24590 	case TCP_DELACK:
24591 		optval = tp->t_delayed_ack;
24592 		break;
24593 	case TCP_DATA_AFTER_CLOSE:
24594 		optval = rack->rc_allow_data_af_clo;
24595 		break;
24596 	case TCP_SHARED_CWND_TIME_LIMIT:
24597 		optval = rack->r_limit_scw;
24598 		break;
24599 	case TCP_HONOR_HPTS_MIN:
24600 		if (rack->r_use_hpts_min)
24601 			optval = rack->r_ctl.max_reduction;
24602 		else
24603 			optval = 0;
24604 		break;
24605 	case TCP_REC_IS_DYN:
24606 		optval = rack->rc_gp_no_rec_chg;
24607 		break;
24608 	case TCP_NO_TIMELY:
24609 		optval = rack->rc_skip_timely;
24610 		break;
24611 	case TCP_RACK_TIMER_SLOP:
24612 		optval = rack->r_ctl.timer_slop;
24613 		break;
24614 	default:
24615 		return (tcp_default_ctloutput(tp, sopt));
24616 		break;
24617 	}
24618 	INP_WUNLOCK(inp);
24619 	if (error == 0) {
24620 		if ((sopt->sopt_name == TCP_PACING_RATE_CAP) ||
24621 		    (sopt->sopt_name == TCP_FILLCW_RATE_CAP))
24622 			error = sooptcopyout(sopt, &loptval, sizeof loptval);
24623 		else
24624 			error = sooptcopyout(sopt, &optval, sizeof optval);
24625 	}
24626 	return (error);
24627 }
24628 
24629 static int
24630 rack_ctloutput(struct tcpcb *tp, struct sockopt *sopt)
24631 {
24632 	if (sopt->sopt_dir == SOPT_SET) {
24633 		return (rack_set_sockopt(tp, sopt));
24634 	} else if (sopt->sopt_dir == SOPT_GET) {
24635 		return (rack_get_sockopt(tp, sopt));
24636 	} else {
24637 		panic("%s: sopt_dir $%d", __func__, sopt->sopt_dir);
24638 	}
24639 }
24640 
24641 static const char *rack_stack_names[] = {
24642 	__XSTRING(STACKNAME),
24643 #ifdef STACKALIAS
24644 	__XSTRING(STACKALIAS),
24645 #endif
24646 };
24647 
24648 static int
24649 rack_ctor(void *mem, int32_t size, void *arg, int32_t how)
24650 {
24651 	memset(mem, 0, size);
24652 	return (0);
24653 }
24654 
24655 static void
24656 rack_dtor(void *mem, int32_t size, void *arg)
24657 {
24658 
24659 }
24660 
24661 static bool rack_mod_inited = false;
24662 
24663 static int
24664 tcp_addrack(module_t mod, int32_t type, void *data)
24665 {
24666 	int32_t err = 0;
24667 	int num_stacks;
24668 
24669 	switch (type) {
24670 	case MOD_LOAD:
24671 		rack_zone = uma_zcreate(__XSTRING(MODNAME) "_map",
24672 		    sizeof(struct rack_sendmap),
24673 		    rack_ctor, rack_dtor, NULL, NULL, UMA_ALIGN_PTR, 0);
24674 
24675 		rack_pcb_zone = uma_zcreate(__XSTRING(MODNAME) "_pcb",
24676 		    sizeof(struct tcp_rack),
24677 		    rack_ctor, NULL, NULL, NULL, UMA_ALIGN_CACHE, 0);
24678 
24679 		sysctl_ctx_init(&rack_sysctl_ctx);
24680 		rack_sysctl_root = SYSCTL_ADD_NODE(&rack_sysctl_ctx,
24681 		    SYSCTL_STATIC_CHILDREN(_net_inet_tcp),
24682 		    OID_AUTO,
24683 #ifdef STACKALIAS
24684 		    __XSTRING(STACKALIAS),
24685 #else
24686 		    __XSTRING(STACKNAME),
24687 #endif
24688 		    CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
24689 		    "");
24690 		if (rack_sysctl_root == NULL) {
24691 			printf("Failed to add sysctl node\n");
24692 			err = EFAULT;
24693 			goto free_uma;
24694 		}
24695 		rack_init_sysctls();
24696 		num_stacks = nitems(rack_stack_names);
24697 		err = register_tcp_functions_as_names(&__tcp_rack, M_WAITOK,
24698 		    rack_stack_names, &num_stacks);
24699 		if (err) {
24700 			printf("Failed to register %s stack name for "
24701 			    "%s module\n", rack_stack_names[num_stacks],
24702 			    __XSTRING(MODNAME));
24703 			sysctl_ctx_free(&rack_sysctl_ctx);
24704 free_uma:
24705 			uma_zdestroy(rack_zone);
24706 			uma_zdestroy(rack_pcb_zone);
24707 			rack_counter_destroy();
24708 			printf("Failed to register rack module -- err:%d\n", err);
24709 			return (err);
24710 		}
24711 		tcp_lro_reg_mbufq();
24712 		rack_mod_inited = true;
24713 		break;
24714 	case MOD_QUIESCE:
24715 		err = deregister_tcp_functions(&__tcp_rack, true, false);
24716 		break;
24717 	case MOD_UNLOAD:
24718 		err = deregister_tcp_functions(&__tcp_rack, false, true);
24719 		if (err == EBUSY)
24720 			break;
24721 		if (rack_mod_inited) {
24722 			uma_zdestroy(rack_zone);
24723 			uma_zdestroy(rack_pcb_zone);
24724 			sysctl_ctx_free(&rack_sysctl_ctx);
24725 			rack_counter_destroy();
24726 			rack_mod_inited = false;
24727 		}
24728 		tcp_lro_dereg_mbufq();
24729 		err = 0;
24730 		break;
24731 	default:
24732 		return (EOPNOTSUPP);
24733 	}
24734 	return (err);
24735 }
24736 
24737 static moduledata_t tcp_rack = {
24738 	.name = __XSTRING(MODNAME),
24739 	.evhand = tcp_addrack,
24740 	.priv = 0
24741 };
24742 
24743 MODULE_VERSION(MODNAME, 1);
24744 DECLARE_MODULE(MODNAME, tcp_rack, SI_SUB_PROTO_DOMAIN, SI_ORDER_ANY);
24745 MODULE_DEPEND(MODNAME, tcphpts, 1, 1, 1);
24746 
24747 #endif /* #if !defined(INET) && !defined(INET6) */
24748