xref: /freebsd/sys/netinet/tcp_stacks/rack.c (revision 6296500a85c8474e3ff3fe2f8e4a9d56dd0acd64) 
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 int32_t rack_enable_hw_pacing = 0; /* Due to CCSP keep it off by default */
208 static int32_t rack_hw_rate_caps = 0; /* 1; */
209 static int32_t rack_hw_rate_cap_per = 0;	/* 0 -- off  */
210 static int32_t rack_hw_rate_min = 0; /* 1500000;*/
211 static int32_t rack_hw_rate_to_low = 0; /* 1200000; */
212 static int32_t rack_hw_up_only = 0;
213 static int32_t rack_stats_gets_ms_rtt = 1;
214 static int32_t rack_prr_addbackmax = 2;
215 static int32_t rack_do_hystart = 0;
216 static int32_t rack_apply_rtt_with_reduced_conf = 0;
217 static int32_t rack_hibeta_setting = 0;
218 static int32_t rack_default_pacing_divisor = 250;
219 static uint16_t rack_pacing_min_seg = 0;
220 static int32_t rack_timely_off = 0;
221 
222 static int32_t rack_pkt_delay = 1000;
223 static int32_t rack_send_a_lot_in_prr = 1;
224 static int32_t rack_min_to = 1000;	/* Number of microsecond  min timeout */
225 static int32_t rack_verbose_logging = 0;
226 static int32_t rack_ignore_data_after_close = 1;
227 static int32_t rack_enable_shared_cwnd = 1;
228 static int32_t rack_use_cmp_acks = 1;
229 static int32_t rack_use_fsb = 1;
230 static int32_t rack_use_rfo = 1;
231 static int32_t rack_use_rsm_rfo = 1;
232 static int32_t rack_max_abc_post_recovery = 2;
233 static int32_t rack_client_low_buf = 0;
234 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 */
235 static int32_t rack_bw_multipler = 0;		/* Limit on fill cw's jump up to be this x gp_est */
236 #ifdef TCP_ACCOUNTING
237 static int32_t rack_tcp_accounting = 0;
238 #endif
239 static int32_t rack_limits_scwnd = 1;
240 static int32_t rack_enable_mqueue_for_nonpaced = 0;
241 static int32_t rack_hybrid_allow_set_maxseg = 0;
242 static int32_t rack_disable_prr = 0;
243 static int32_t use_rack_rr = 1;
244 static int32_t rack_non_rxt_use_cr = 0; /* does a non-rxt in recovery use the configured rate (ss/ca)? */
245 static int32_t rack_persist_min = 250000;	/* 250usec */
246 static int32_t rack_persist_max = 2000000;	/* 2 Second in usec's */
247 static int32_t rack_honors_hpts_min_to =  1;	/* Do we honor the hpts minimum time out for pacing timers */
248 static uint32_t rack_max_reduce = 10;		/* Percent we can reduce pacing delay by */
249 static int32_t rack_sack_not_required = 1;	/* set to one to allow non-sack to use rack */
250 static int32_t rack_limit_time_with_srtt = 0;
251 static int32_t rack_autosndbuf_inc = 20;	/* In percentage form */
252 static int32_t rack_enobuf_hw_boost_mult = 0;	/* How many times the hw rate we boost pacing delay using time_between */
253 static int32_t rack_enobuf_hw_max = 12000;	/* 12 ms in usecs */
254 static int32_t rack_enobuf_hw_min = 10000;	/* 10 ms in usecs */
255 static int32_t rack_hw_rwnd_factor = 2;		/* How many max_segs the rwnd must be before we hold off sending */
256 static int32_t rack_hw_check_queue = 0;		/* Do we always pre-check queue depth of a hw queue */
257 
258 /*
259  * Currently regular tcp has a rto_min of 30ms
260  * the backoff goes 12 times so that ends up
261  * being a total of 122.850 seconds before a
262  * connection is killed.
263  */
264 static uint32_t rack_def_data_window = 20;
265 static uint32_t rack_goal_bdp = 2;
266 static uint32_t rack_min_srtts = 1;
267 static uint32_t rack_min_measure_usec = 0;
268 static int32_t rack_tlp_min = 10000;	/* 10ms */
269 static int32_t rack_rto_min = 30000;	/* 30,000 usec same as main freebsd */
270 static int32_t rack_rto_max = 4000000;	/* 4 seconds in usec's */
271 static const int32_t rack_free_cache = 2;
272 static int32_t rack_hptsi_segments = 40;
273 static int32_t rack_rate_sample_method = USE_RTT_LOW;
274 static int32_t rack_pace_every_seg = 0;
275 static int32_t rack_delayed_ack_time = 40000;	/* 40ms in usecs */
276 static int32_t rack_pacing_delay_reduction = 4;
277 static int32_t rack_wma_divisor = 8;		/* For WMA calculation */
278 static int32_t rack_cwnd_block_ends_measure = 0;
279 static int32_t rack_rwnd_block_ends_measure = 0;
280 static int32_t rack_def_profile = 0;
281 
282 static int32_t rack_lower_cwnd_at_tlp = 0;
283 static int32_t rack_always_send_oldest = 0;
284 static int32_t rack_tlp_threshold_use = TLP_USE_TWO_ONE;
285 
286 static uint16_t rack_per_of_gp_ss = 250;	/* 250 % slow-start */
287 static uint16_t rack_per_of_gp_ca = 200;	/* 200 % congestion-avoidance */
288 static uint16_t rack_per_of_gp_rec = 200;	/* 200 % of bw */
289 
290 /* Probertt */
291 static uint16_t rack_per_of_gp_probertt = 60;	/* 60% of bw */
292 static uint16_t rack_per_of_gp_lowthresh = 40;	/* 40% is bottom */
293 static uint16_t rack_per_of_gp_probertt_reduce = 10; /* 10% reduction */
294 static uint16_t rack_atexit_prtt_hbp = 130;	/* Clamp to 130% on exit prtt if highly buffered path */
295 static uint16_t rack_atexit_prtt = 130;	/* Clamp to 100% on exit prtt if non highly buffered path */
296 
297 static uint32_t rack_max_drain_wait = 2;	/* How man gp srtt's before we give up draining */
298 static uint32_t rack_must_drain = 1;		/* How many GP srtt's we *must* wait */
299 static uint32_t rack_probertt_use_min_rtt_entry = 1;	/* Use the min to calculate the goal else gp_srtt */
300 static uint32_t rack_probertt_use_min_rtt_exit = 0;
301 static uint32_t rack_probe_rtt_sets_cwnd = 0;
302 static uint32_t rack_probe_rtt_safety_val = 2000000;	/* No more than 2 sec in probe-rtt */
303 static uint32_t rack_time_between_probertt = 9600000;	/* 9.6 sec in usecs */
304 static uint32_t rack_probertt_gpsrtt_cnt_mul = 0;	/* How many srtt periods does probe-rtt last top fraction */
305 static uint32_t rack_probertt_gpsrtt_cnt_div = 0;	/* How many srtt periods does probe-rtt last bottom fraction */
306 static uint32_t rack_min_probertt_hold = 40000;		/* Equal to delayed ack time */
307 static uint32_t rack_probertt_filter_life = 10000000;
308 static uint32_t rack_probertt_lower_within = 10;
309 static uint32_t rack_min_rtt_movement = 250000;	/* Must move at least 250ms (in microseconds)  to count as a lowering */
310 static int32_t rack_pace_one_seg = 0;		/* Shall we pace for less than 1.4Meg 1MSS at a time */
311 static int32_t rack_probertt_clear_is = 1;
312 static int32_t rack_max_drain_hbp = 1;		/* Extra drain times gpsrtt for highly buffered paths */
313 static int32_t rack_hbp_thresh = 3;		/* what is the divisor max_rtt/min_rtt to decided a hbp */
314 
315 /* Part of pacing */
316 static int32_t rack_max_per_above = 30;		/* When we go to increment stop if above 100+this% */
317 
318 /* Timely information:
319  *
320  * Here we have various control parameters on how
321  * timely may change the multiplier. rack_gain_p5_ub
322  * is associated with timely but not directly influencing
323  * the rate decision like the other variables. It controls
324  * the way fill-cw interacts with timely and caps how much
325  * timely can boost the fill-cw b/w.
326  *
327  * The other values are various boost/shrink numbers as well
328  * as potential caps when adjustments are made to the timely
329  * gain (returned by rack_get_output_gain(). Remember too that
330  * the gain returned can be overriden by other factors such as
331  * probeRTT as well as fixed-rate-pacing.
332  */
333 static int32_t rack_gain_p5_ub = 250;
334 static int32_t rack_gp_per_bw_mul_up = 2;	/* 2% */
335 static int32_t rack_gp_per_bw_mul_down = 4;	/* 4% */
336 static int32_t rack_gp_rtt_maxmul = 3;		/* 3 x maxmin */
337 static int32_t rack_gp_rtt_minmul = 1;		/* minrtt + (minrtt/mindiv) is lower rtt */
338 static int32_t rack_gp_rtt_mindiv = 4;		/* minrtt + (minrtt * minmul/mindiv) is lower rtt */
339 static int32_t rack_gp_decrease_per = 80;	/* Beta value of timely decrease (.8) = 80 */
340 static int32_t rack_gp_increase_per = 2;	/* 2% increase in multiplier */
341 static int32_t rack_per_lower_bound = 50;	/* Don't allow to drop below this multiplier */
342 static int32_t rack_per_upper_bound_ss = 0;	/* Don't allow SS to grow above this */
343 static int32_t rack_per_upper_bound_ca = 0;	/* Don't allow CA to grow above this */
344 static int32_t rack_do_dyn_mul = 0;		/* Are the rack gp multipliers dynamic */
345 static int32_t rack_gp_no_rec_chg = 1;		/* Prohibit recovery from reducing it's multiplier */
346 static int32_t rack_timely_dec_clear = 6;	/* Do we clear decrement count at a value (6)? */
347 static int32_t rack_timely_max_push_rise = 3;	/* One round of pushing */
348 static int32_t rack_timely_max_push_drop = 3;	/* Three round of pushing */
349 static int32_t rack_timely_min_segs = 4;	/* 4 segment minimum */
350 static int32_t rack_timely_no_stopping = 0;
351 static int32_t rack_down_raise_thresh = 100;
352 static int32_t rack_req_segs = 1;
353 static uint64_t rack_bw_rate_cap = 0;
354 static uint64_t rack_fillcw_bw_cap = 3750000;	/* Cap fillcw at 30Mbps */
355 
356 
357 /* Rack specific counters */
358 counter_u64_t rack_saw_enobuf;
359 counter_u64_t rack_saw_enobuf_hw;
360 counter_u64_t rack_saw_enetunreach;
361 counter_u64_t rack_persists_sends;
362 counter_u64_t rack_persists_acks;
363 counter_u64_t rack_persists_loss;
364 counter_u64_t rack_persists_lost_ends;
365 counter_u64_t rack_total_bytes;
366 #ifdef INVARIANTS
367 counter_u64_t rack_adjust_map_bw;
368 #endif
369 /* Tail loss probe counters */
370 counter_u64_t rack_tlp_tot;
371 counter_u64_t rack_tlp_newdata;
372 counter_u64_t rack_tlp_retran;
373 counter_u64_t rack_tlp_retran_bytes;
374 counter_u64_t rack_to_tot;
375 counter_u64_t rack_hot_alloc;
376 counter_u64_t rack_to_alloc;
377 counter_u64_t rack_to_alloc_hard;
378 counter_u64_t rack_to_alloc_emerg;
379 counter_u64_t rack_to_alloc_limited;
380 counter_u64_t rack_alloc_limited_conns;
381 counter_u64_t rack_split_limited;
382 counter_u64_t rack_rxt_clamps_cwnd;
383 counter_u64_t rack_rxt_clamps_cwnd_uniq;
384 
385 counter_u64_t rack_multi_single_eq;
386 counter_u64_t rack_proc_non_comp_ack;
387 
388 counter_u64_t rack_fto_send;
389 counter_u64_t rack_fto_rsm_send;
390 counter_u64_t rack_nfto_resend;
391 counter_u64_t rack_non_fto_send;
392 counter_u64_t rack_extended_rfo;
393 
394 counter_u64_t rack_sack_proc_all;
395 counter_u64_t rack_sack_proc_short;
396 counter_u64_t rack_sack_proc_restart;
397 
398 counter_u64_t rack_input_idle_reduces;
399 counter_u64_t rack_collapsed_win;
400 counter_u64_t rack_collapsed_win_seen;
401 counter_u64_t rack_collapsed_win_rxt;
402 counter_u64_t rack_collapsed_win_rxt_bytes;
403 counter_u64_t rack_try_scwnd;
404 counter_u64_t rack_hw_pace_init_fail;
405 counter_u64_t rack_hw_pace_lost;
406 
407 counter_u64_t rack_out_size[TCP_MSS_ACCT_SIZE];
408 counter_u64_t rack_opts_arry[RACK_OPTS_SIZE];
409 
410 
411 #define	RACK_REXMTVAL(tp) max(rack_rto_min, ((tp)->t_srtt + ((tp)->t_rttvar << 2)))
412 
413 #define	RACK_TCPT_RANGESET(tv, value, tvmin, tvmax, slop) do {	\
414 	(tv) = (value) + slop;	 \
415 	if ((u_long)(tv) < (u_long)(tvmin)) \
416 		(tv) = (tvmin); \
417 	if ((u_long)(tv) > (u_long)(tvmax)) \
418 		(tv) = (tvmax); \
419 } while (0)
420 
421 static void
422 rack_log_progress_event(struct tcp_rack *rack, struct tcpcb *tp, uint32_t tick,  int event, int line);
423 
424 static int
425 rack_process_ack(struct mbuf *m, struct tcphdr *th,
426     struct socket *so, struct tcpcb *tp, struct tcpopt *to,
427     uint32_t tiwin, int32_t tlen, int32_t * ofia, int32_t thflags, int32_t * ret_val, int32_t orig_tlen);
428 static int
429 rack_process_data(struct mbuf *m, struct tcphdr *th,
430     struct socket *so, struct tcpcb *tp, int32_t drop_hdrlen, int32_t tlen,
431     uint32_t tiwin, int32_t thflags, int32_t nxt_pkt);
432 static void
433 rack_ack_received(struct tcpcb *tp, struct tcp_rack *rack,
434    uint32_t th_ack, uint16_t nsegs, uint16_t type, int32_t recovery);
435 static struct rack_sendmap *rack_alloc(struct tcp_rack *rack);
436 static struct rack_sendmap *rack_alloc_limit(struct tcp_rack *rack,
437     uint8_t limit_type);
438 static struct rack_sendmap *
439 rack_check_recovery_mode(struct tcpcb *tp,
440     uint32_t tsused);
441 static uint32_t
442 rack_grab_rtt(struct tcpcb *tp, struct tcp_rack *rack);
443 static void
444 rack_cong_signal(struct tcpcb *tp,
445 		 uint32_t type, uint32_t ack, int );
446 static void rack_counter_destroy(void);
447 static int
448 rack_ctloutput(struct tcpcb *tp, struct sockopt *sopt);
449 static int32_t rack_ctor(void *mem, int32_t size, void *arg, int32_t how);
450 static void
451 rack_set_pace_segments(struct tcpcb *tp, struct tcp_rack *rack, uint32_t line, uint64_t *fill_override);
452 static void
453 rack_do_segment(struct tcpcb *tp, struct mbuf *m, struct tcphdr *th,
454     int32_t drop_hdrlen, int32_t tlen, uint8_t iptos);
455 static void rack_dtor(void *mem, int32_t size, void *arg);
456 static void
457 rack_log_alt_to_to_cancel(struct tcp_rack *rack,
458     uint32_t flex1, uint32_t flex2,
459     uint32_t flex3, uint32_t flex4,
460     uint32_t flex5, uint32_t flex6,
461     uint16_t flex7, uint8_t mod);
462 
463 static void
464 rack_log_pacing_delay_calc(struct tcp_rack *rack, uint32_t len, uint32_t pacing_delay,
465    uint64_t bw_est, uint64_t bw, uint64_t len_time, int method, int line,
466    struct rack_sendmap *rsm, uint8_t quality);
467 static struct rack_sendmap *
468 rack_find_high_nonack(struct tcp_rack *rack,
469     struct rack_sendmap *rsm);
470 static struct rack_sendmap *rack_find_lowest_rsm(struct tcp_rack *rack);
471 static void rack_free(struct tcp_rack *rack, struct rack_sendmap *rsm);
472 static void rack_fini(struct tcpcb *tp, int32_t tcb_is_purged);
473 static int rack_get_sockopt(struct tcpcb *tp, struct sockopt *sopt);
474 static void
475 rack_do_goodput_measurement(struct tcpcb *tp, struct tcp_rack *rack,
476 			    tcp_seq th_ack, int line, uint8_t quality);
477 static void
478 rack_log_type_pacing_sizes(struct tcpcb *tp, struct tcp_rack *rack, uint32_t arg1, uint32_t arg2, uint32_t arg3, uint8_t frm);
479 
480 static uint32_t
481 rack_get_pacing_len(struct tcp_rack *rack, uint64_t bw, uint32_t mss);
482 static int32_t rack_handoff_ok(struct tcpcb *tp);
483 static int32_t rack_init(struct tcpcb *tp, void **ptr);
484 static void rack_init_sysctls(void);
485 
486 static void
487 rack_log_ack(struct tcpcb *tp, struct tcpopt *to,
488     struct tcphdr *th, int entered_rec, int dup_ack_struck,
489     int *dsack_seen, int *sacks_seen);
490 static void
491 rack_log_output(struct tcpcb *tp, struct tcpopt *to, int32_t len,
492     uint32_t seq_out, uint16_t th_flags, int32_t err, uint64_t ts,
493     struct rack_sendmap *hintrsm, uint32_t add_flags, struct mbuf *s_mb, uint32_t s_moff, int hw_tls, int segsiz);
494 
495 static uint64_t rack_get_gp_est(struct tcp_rack *rack);
496 
497 
498 static void
499 rack_log_sack_passed(struct tcpcb *tp, struct tcp_rack *rack,
500     struct rack_sendmap *rsm, uint32_t cts);
501 static void rack_log_to_event(struct tcp_rack *rack, int32_t to_num, struct rack_sendmap *rsm);
502 static int32_t rack_output(struct tcpcb *tp);
503 
504 static uint32_t
505 rack_proc_sack_blk(struct tcpcb *tp, struct tcp_rack *rack,
506     struct sackblk *sack, struct tcpopt *to, struct rack_sendmap **prsm,
507     uint32_t cts, uint32_t segsiz);
508 static void rack_post_recovery(struct tcpcb *tp, uint32_t th_seq);
509 static void rack_remxt_tmr(struct tcpcb *tp);
510 static int rack_set_sockopt(struct tcpcb *tp, struct sockopt *sopt);
511 static void rack_set_state(struct tcpcb *tp, struct tcp_rack *rack);
512 static int32_t rack_stopall(struct tcpcb *tp);
513 static void rack_timer_cancel(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cts, int line);
514 static uint32_t
515 rack_update_entry(struct tcpcb *tp, struct tcp_rack *rack,
516     struct rack_sendmap *rsm, uint64_t ts, int32_t * lenp, uint32_t add_flag, int segsiz);
517 static void
518 rack_update_rsm(struct tcpcb *tp, struct tcp_rack *rack,
519     struct rack_sendmap *rsm, uint64_t ts, uint32_t add_flag, int segsiz);
520 static int
521 rack_update_rtt(struct tcpcb *tp, struct tcp_rack *rack,
522     struct rack_sendmap *rsm, struct tcpopt *to, uint32_t cts, int32_t ack_type, tcp_seq th_ack);
523 static int32_t tcp_addrack(module_t mod, int32_t type, void *data);
524 static int
525 rack_do_close_wait(struct mbuf *m, struct tcphdr *th,
526     struct socket *so, struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen,
527     int32_t tlen, uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos);
528 
529 static int
530 rack_do_closing(struct mbuf *m, struct tcphdr *th,
531     struct socket *so, struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen,
532     int32_t tlen, uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos);
533 static int
534 rack_do_established(struct mbuf *m, struct tcphdr *th,
535     struct socket *so, struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen,
536     int32_t tlen, uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos);
537 static int
538 rack_do_fastnewdata(struct mbuf *m, struct tcphdr *th,
539     struct socket *so, struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen,
540     int32_t tlen, uint32_t tiwin, int32_t nxt_pkt, uint8_t iptos);
541 static int
542 rack_do_fin_wait_1(struct mbuf *m, struct tcphdr *th,
543     struct socket *so, struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen,
544     int32_t tlen, uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos);
545 static int
546 rack_do_fin_wait_2(struct mbuf *m, struct tcphdr *th,
547     struct socket *so, struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen,
548     int32_t tlen, uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos);
549 static int
550 rack_do_lastack(struct mbuf *m, struct tcphdr *th,
551     struct socket *so, struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen,
552     int32_t tlen, uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos);
553 static int
554 rack_do_syn_recv(struct mbuf *m, struct tcphdr *th,
555     struct socket *so, struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen,
556     int32_t tlen, uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos);
557 static int
558 rack_do_syn_sent(struct mbuf *m, struct tcphdr *th,
559     struct socket *so, struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen,
560     int32_t tlen, uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos);
561 static void rack_chk_req_and_hybrid_on_out(struct tcp_rack *rack, tcp_seq seq, uint32_t len, uint64_t cts);
562 struct rack_sendmap *
563 tcp_rack_output(struct tcpcb *tp, struct tcp_rack *rack,
564     uint32_t tsused);
565 static void tcp_rack_xmit_timer(struct tcp_rack *rack, int32_t rtt,
566     uint32_t len, uint32_t us_tim, int confidence, struct rack_sendmap *rsm, uint16_t rtrcnt);
567 static void
568      tcp_rack_partialack(struct tcpcb *tp);
569 static int
570 rack_set_profile(struct tcp_rack *rack, int prof);
571 static void
572 rack_apply_deferred_options(struct tcp_rack *rack);
573 
574 int32_t rack_clear_counter=0;
575 
576 static uint64_t
577 rack_get_lt_bw(struct tcp_rack *rack)
578 {
579 	struct timeval tv;
580 	uint64_t tim, bytes;
581 
582 	tim = rack->r_ctl.lt_bw_time;
583 	bytes = rack->r_ctl.lt_bw_bytes;
584 	if (rack->lt_bw_up) {
585 		/* Include all the current bytes too */
586 		microuptime(&tv);
587 		bytes += (rack->rc_tp->snd_una - rack->r_ctl.lt_seq);
588 		tim += (tcp_tv_to_lusec(&tv) - rack->r_ctl.lt_timemark);
589 	}
590 	if ((bytes != 0) && (tim != 0))
591 		return ((bytes * (uint64_t)1000000) / tim);
592 	else
593 		return (0);
594 }
595 
596 static void
597 rack_swap_beta_values(struct tcp_rack *rack, uint8_t flex8)
598 {
599 	struct sockopt sopt;
600 	struct cc_newreno_opts opt;
601 	struct tcpcb *tp;
602 	uint32_t old_beta;
603 	uint32_t old_beta_ecn;
604 	int error = 0, failed = 0;
605 
606 	tp = rack->rc_tp;
607 	if (tp->t_cc == NULL) {
608 		/* Tcb is leaving */
609 		return;
610 	}
611 	rack->rc_pacing_cc_set = 1;
612 	if (strcmp(tp->t_cc->name, CCALGONAME_NEWRENO) != 0) {
613 		/* Not new-reno we can't play games with beta! */
614 		failed = 1;
615 		goto out;
616 
617 	}
618 	if (CC_ALGO(tp)->ctl_output == NULL)  {
619 		/* Huh, not using new-reno so no swaps.? */
620 		failed = 2;
621 		goto out;
622 	}
623 	/* Get the current values out */
624 	sopt.sopt_valsize = sizeof(struct cc_newreno_opts);
625 	sopt.sopt_dir = SOPT_GET;
626 	opt.name = CC_NEWRENO_BETA;
627 	error = CC_ALGO(tp)->ctl_output(&tp->t_ccv, &sopt, &opt);
628 	if (error)  {
629 		failed = 3;
630 		goto out;
631 	}
632 	old_beta = opt.val;
633 	opt.name = CC_NEWRENO_BETA_ECN;
634 	error = CC_ALGO(tp)->ctl_output(&tp->t_ccv, &sopt, &opt);
635 	if (error)  {
636 		failed = 4;
637 		goto out;
638 	}
639 	old_beta_ecn = opt.val;
640 
641 	/* Now lets set in the values we have stored */
642 	sopt.sopt_dir = SOPT_SET;
643 	opt.name = CC_NEWRENO_BETA;
644 	opt.val = rack->r_ctl.rc_saved_beta;
645 	error = CC_ALGO(tp)->ctl_output(&tp->t_ccv, &sopt, &opt);
646 	if (error)  {
647 		failed = 5;
648 		goto out;
649 	}
650 	opt.name = CC_NEWRENO_BETA_ECN;
651 	opt.val = rack->r_ctl.rc_saved_beta_ecn;
652 	error = CC_ALGO(tp)->ctl_output(&tp->t_ccv, &sopt, &opt);
653 	if (error) {
654 		failed = 6;
655 		goto out;
656 	}
657 	/* Save off the values for restoral */
658 	rack->r_ctl.rc_saved_beta = old_beta;
659 	rack->r_ctl.rc_saved_beta_ecn = old_beta_ecn;
660 out:
661 	if (rack_verbose_logging && tcp_bblogging_on(rack->rc_tp)) {
662 		union tcp_log_stackspecific log;
663 		struct timeval tv;
664 		struct newreno *ptr;
665 
666 		ptr = ((struct newreno *)tp->t_ccv.cc_data);
667 		memset(&log, 0, sizeof(log));
668 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
669 		log.u_bbr.flex1 = ptr->beta;
670 		log.u_bbr.flex2 = ptr->beta_ecn;
671 		log.u_bbr.flex3 = ptr->newreno_flags;
672 		log.u_bbr.flex4 = rack->r_ctl.rc_saved_beta;
673 		log.u_bbr.flex5 = rack->r_ctl.rc_saved_beta_ecn;
674 		log.u_bbr.flex6 = failed;
675 		log.u_bbr.flex7 = rack->gp_ready;
676 		log.u_bbr.flex7 <<= 1;
677 		log.u_bbr.flex7 |= rack->use_fixed_rate;
678 		log.u_bbr.flex7 <<= 1;
679 		log.u_bbr.flex7 |= rack->rc_pacing_cc_set;
680 		log.u_bbr.pkts_out = rack->r_ctl.rc_prr_sndcnt;
681 		log.u_bbr.flex8 = flex8;
682 		tcp_log_event(tp, NULL, NULL, NULL, BBR_LOG_CWND, error,
683 			       0, &log, false, NULL, NULL, 0, &tv);
684 	}
685 }
686 
687 static void
688 rack_set_cc_pacing(struct tcp_rack *rack)
689 {
690 	if (rack->rc_pacing_cc_set)
691 		return;
692 	/*
693 	 * Use the swap utility placing in 3 for flex8 to id a
694 	 * set of a new set of values.
695 	 */
696 	rack->rc_pacing_cc_set = 1;
697 	rack_swap_beta_values(rack, 3);
698 }
699 
700 static void
701 rack_undo_cc_pacing(struct tcp_rack *rack)
702 {
703 	if (rack->rc_pacing_cc_set == 0)
704 		return;
705 	/*
706 	 * Use the swap utility placing in 4 for flex8 to id a
707 	 * restoral of the old values.
708 	 */
709 	rack->rc_pacing_cc_set = 0;
710 	rack_swap_beta_values(rack, 4);
711 }
712 
713 static void
714 rack_remove_pacing(struct tcp_rack *rack)
715 {
716 	if (rack->rc_pacing_cc_set)
717 		rack_undo_cc_pacing(rack);
718 	if (rack->r_ctl.pacing_method & RACK_REG_PACING)
719 		tcp_decrement_paced_conn();
720 	if (rack->r_ctl.pacing_method & RACK_DGP_PACING)
721 		tcp_dec_dgp_pacing_cnt();
722 	rack->rc_always_pace = 0;
723 	rack->r_ctl.pacing_method = RACK_PACING_NONE;
724 	rack->dgp_on = 0;
725 	rack->rc_hybrid_mode = 0;
726 	rack->use_fixed_rate = 0;
727 }
728 
729 static void
730 rack_log_gpset(struct tcp_rack *rack, uint32_t seq_end, uint32_t ack_end_t,
731 	       uint32_t send_end_t, int line, uint8_t mode, struct rack_sendmap *rsm)
732 {
733 	if (tcp_bblogging_on(rack->rc_tp) && (rack_verbose_logging != 0)) {
734 		union tcp_log_stackspecific log;
735 		struct timeval tv;
736 
737 		memset(&log, 0, sizeof(log));
738 		log.u_bbr.flex1 = seq_end;
739 		log.u_bbr.flex2 = rack->rc_tp->gput_seq;
740 		log.u_bbr.flex3 = ack_end_t;
741 		log.u_bbr.flex4 = rack->rc_tp->gput_ts;
742 		log.u_bbr.flex5 = send_end_t;
743 		log.u_bbr.flex6 = rack->rc_tp->gput_ack;
744 		log.u_bbr.flex7 = mode;
745 		log.u_bbr.flex8 = 69;
746 		log.u_bbr.rttProp = rack->r_ctl.rc_gp_cumack_ts;
747 		log.u_bbr.delRate = rack->r_ctl.rc_gp_output_ts;
748 		log.u_bbr.pkts_out = line;
749 		log.u_bbr.cwnd_gain = rack->app_limited_needs_set;
750 		log.u_bbr.pkt_epoch = rack->r_ctl.rc_app_limited_cnt;
751 		log.u_bbr.epoch = rack->r_ctl.current_round;
752 		log.u_bbr.lt_epoch = rack->r_ctl.rc_considered_lost;
753 		if (rsm != NULL) {
754 			log.u_bbr.applimited = rsm->r_start;
755 			log.u_bbr.delivered = rsm->r_end;
756 			log.u_bbr.epoch = rsm->r_flags;
757 		}
758 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
759 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
760 		    &rack->rc_inp->inp_socket->so_rcv,
761 		    &rack->rc_inp->inp_socket->so_snd,
762 		    BBR_LOG_HPTSI_CALC, 0,
763 		    0, &log, false, &tv);
764 	}
765 }
766 
767 static int
768 sysctl_rack_clear(SYSCTL_HANDLER_ARGS)
769 {
770 	uint32_t stat;
771 	int32_t error;
772 
773 	error = SYSCTL_OUT(req, &rack_clear_counter, sizeof(uint32_t));
774 	if (error || req->newptr == NULL)
775 		return error;
776 
777 	error = SYSCTL_IN(req, &stat, sizeof(uint32_t));
778 	if (error)
779 		return (error);
780 	if (stat == 1) {
781 #ifdef INVARIANTS
782 		printf("Clearing RACK counters\n");
783 #endif
784 		counter_u64_zero(rack_tlp_tot);
785 		counter_u64_zero(rack_tlp_newdata);
786 		counter_u64_zero(rack_tlp_retran);
787 		counter_u64_zero(rack_tlp_retran_bytes);
788 		counter_u64_zero(rack_to_tot);
789 		counter_u64_zero(rack_saw_enobuf);
790 		counter_u64_zero(rack_saw_enobuf_hw);
791 		counter_u64_zero(rack_saw_enetunreach);
792 		counter_u64_zero(rack_persists_sends);
793 		counter_u64_zero(rack_total_bytes);
794 		counter_u64_zero(rack_persists_acks);
795 		counter_u64_zero(rack_persists_loss);
796 		counter_u64_zero(rack_persists_lost_ends);
797 #ifdef INVARIANTS
798 		counter_u64_zero(rack_adjust_map_bw);
799 #endif
800 		counter_u64_zero(rack_to_alloc_hard);
801 		counter_u64_zero(rack_to_alloc_emerg);
802 		counter_u64_zero(rack_sack_proc_all);
803 		counter_u64_zero(rack_fto_send);
804 		counter_u64_zero(rack_fto_rsm_send);
805 		counter_u64_zero(rack_extended_rfo);
806 		counter_u64_zero(rack_hw_pace_init_fail);
807 		counter_u64_zero(rack_hw_pace_lost);
808 		counter_u64_zero(rack_non_fto_send);
809 		counter_u64_zero(rack_nfto_resend);
810 		counter_u64_zero(rack_sack_proc_short);
811 		counter_u64_zero(rack_sack_proc_restart);
812 		counter_u64_zero(rack_to_alloc);
813 		counter_u64_zero(rack_to_alloc_limited);
814 		counter_u64_zero(rack_alloc_limited_conns);
815 		counter_u64_zero(rack_split_limited);
816 		counter_u64_zero(rack_rxt_clamps_cwnd);
817 		counter_u64_zero(rack_rxt_clamps_cwnd_uniq);
818 		counter_u64_zero(rack_multi_single_eq);
819 		counter_u64_zero(rack_proc_non_comp_ack);
820 		counter_u64_zero(rack_try_scwnd);
821 		counter_u64_zero(rack_collapsed_win);
822 		counter_u64_zero(rack_collapsed_win_rxt);
823 		counter_u64_zero(rack_collapsed_win_seen);
824 		counter_u64_zero(rack_collapsed_win_rxt_bytes);
825 	} else if (stat == 2) {
826 #ifdef INVARIANTS
827 		printf("Clearing RACK option array\n");
828 #endif
829 		COUNTER_ARRAY_ZERO(rack_opts_arry, RACK_OPTS_SIZE);
830 	} else if (stat == 3) {
831 		printf("Rack has no stats counters to clear (use 1 to clear all stats in sysctl node)\n");
832 	} else if (stat == 4) {
833 #ifdef INVARIANTS
834 		printf("Clearing RACK out size array\n");
835 #endif
836 		COUNTER_ARRAY_ZERO(rack_out_size, TCP_MSS_ACCT_SIZE);
837 	}
838 	rack_clear_counter = 0;
839 	return (0);
840 }
841 
842 static void
843 rack_init_sysctls(void)
844 {
845 	struct sysctl_oid *rack_counters;
846 	struct sysctl_oid *rack_pacing;
847 	struct sysctl_oid *rack_timely;
848 	struct sysctl_oid *rack_timers;
849 	struct sysctl_oid *rack_tlp;
850 	struct sysctl_oid *rack_misc;
851 	struct sysctl_oid *rack_features;
852 	struct sysctl_oid *rack_measure;
853 	struct sysctl_oid *rack_probertt;
854 	struct sysctl_oid *rack_hw_pacing;
855 
856 	rack_counters = SYSCTL_ADD_NODE(&rack_sysctl_ctx,
857 	    SYSCTL_CHILDREN(rack_sysctl_root),
858 	    OID_AUTO,
859 	    "stats",
860 	    CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
861 	    "Rack Counters");
862 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
863 	    SYSCTL_CHILDREN(rack_sysctl_root),
864 	    OID_AUTO, "rate_sample_method", CTLFLAG_RW,
865 	    &rack_rate_sample_method , USE_RTT_LOW,
866 	    "What method should we use for rate sampling 0=high, 1=low ");
867 	/* Probe rtt related controls */
868 	rack_probertt = SYSCTL_ADD_NODE(&rack_sysctl_ctx,
869 	    SYSCTL_CHILDREN(rack_sysctl_root),
870 	    OID_AUTO,
871 	    "probertt",
872 	    CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
873 	    "ProbeRTT related Controls");
874 	SYSCTL_ADD_U16(&rack_sysctl_ctx,
875 	    SYSCTL_CHILDREN(rack_probertt),
876 	    OID_AUTO, "exit_per_hpb", CTLFLAG_RW,
877 	    &rack_atexit_prtt_hbp, 130,
878 	    "What percentage above goodput do we clamp CA/SS to at exit on high-BDP path 110%");
879 	SYSCTL_ADD_U16(&rack_sysctl_ctx,
880 	    SYSCTL_CHILDREN(rack_probertt),
881 	    OID_AUTO, "exit_per_nonhpb", CTLFLAG_RW,
882 	    &rack_atexit_prtt, 130,
883 	    "What percentage above goodput do we clamp CA/SS to at exit on a non high-BDP path 100%");
884 	SYSCTL_ADD_U16(&rack_sysctl_ctx,
885 	    SYSCTL_CHILDREN(rack_probertt),
886 	    OID_AUTO, "gp_per_mul", CTLFLAG_RW,
887 	    &rack_per_of_gp_probertt, 60,
888 	    "What percentage of goodput do we pace at in probertt");
889 	SYSCTL_ADD_U16(&rack_sysctl_ctx,
890 	    SYSCTL_CHILDREN(rack_probertt),
891 	    OID_AUTO, "gp_per_reduce", CTLFLAG_RW,
892 	    &rack_per_of_gp_probertt_reduce, 10,
893 	    "What percentage of goodput do we reduce every gp_srtt");
894 	SYSCTL_ADD_U16(&rack_sysctl_ctx,
895 	    SYSCTL_CHILDREN(rack_probertt),
896 	    OID_AUTO, "gp_per_low", CTLFLAG_RW,
897 	    &rack_per_of_gp_lowthresh, 40,
898 	    "What percentage of goodput do we allow the multiplier to fall to");
899 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
900 	    SYSCTL_CHILDREN(rack_probertt),
901 	    OID_AUTO, "time_between", CTLFLAG_RW,
902 	    &rack_time_between_probertt, 96000000,
903 	    "How many useconds between the lowest rtt falling must past before we enter probertt");
904 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
905 	    SYSCTL_CHILDREN(rack_probertt),
906 	    OID_AUTO, "safety", CTLFLAG_RW,
907 	    &rack_probe_rtt_safety_val, 2000000,
908 	    "If not zero, provides a maximum usecond that you can stay in probertt (2sec = 2000000)");
909 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
910 	    SYSCTL_CHILDREN(rack_probertt),
911 	    OID_AUTO, "sets_cwnd", CTLFLAG_RW,
912 	    &rack_probe_rtt_sets_cwnd, 0,
913 	    "Do we set the cwnd too (if always_lower is on)");
914 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
915 	    SYSCTL_CHILDREN(rack_probertt),
916 	    OID_AUTO, "maxdrainsrtts", CTLFLAG_RW,
917 	    &rack_max_drain_wait, 2,
918 	    "Maximum number of gp_srtt's to hold in drain waiting for flight to reach goal");
919 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
920 	    SYSCTL_CHILDREN(rack_probertt),
921 	    OID_AUTO, "mustdrainsrtts", CTLFLAG_RW,
922 	    &rack_must_drain, 1,
923 	    "We must drain this many gp_srtt's waiting for flight to reach goal");
924 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
925 	    SYSCTL_CHILDREN(rack_probertt),
926 	    OID_AUTO, "goal_use_min_entry", CTLFLAG_RW,
927 	    &rack_probertt_use_min_rtt_entry, 1,
928 	    "Should we use the min-rtt to calculate the goal rtt (else gp_srtt) at entry");
929 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
930 	    SYSCTL_CHILDREN(rack_probertt),
931 	    OID_AUTO, "goal_use_min_exit", CTLFLAG_RW,
932 	    &rack_probertt_use_min_rtt_exit, 0,
933 	    "How to set cwnd at exit, 0 - dynamic, 1 - use min-rtt, 2 - use curgprtt, 3 - entry gp-rtt");
934 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
935 	    SYSCTL_CHILDREN(rack_probertt),
936 	    OID_AUTO, "length_div", CTLFLAG_RW,
937 	    &rack_probertt_gpsrtt_cnt_div, 0,
938 	    "How many recent goodput srtt periods plus hold tim does probertt last (bottom of fraction)");
939 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
940 	    SYSCTL_CHILDREN(rack_probertt),
941 	    OID_AUTO, "length_mul", CTLFLAG_RW,
942 	    &rack_probertt_gpsrtt_cnt_mul, 0,
943 	    "How many recent goodput srtt periods plus hold tim does probertt last (top of fraction)");
944 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
945 	    SYSCTL_CHILDREN(rack_probertt),
946 	    OID_AUTO, "holdtim_at_target", CTLFLAG_RW,
947 	    &rack_min_probertt_hold, 200000,
948 	    "What is the minimum time we hold probertt at target");
949 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
950 	    SYSCTL_CHILDREN(rack_probertt),
951 	    OID_AUTO, "filter_life", CTLFLAG_RW,
952 	    &rack_probertt_filter_life, 10000000,
953 	    "What is the time for the filters life in useconds");
954 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
955 	    SYSCTL_CHILDREN(rack_probertt),
956 	    OID_AUTO, "lower_within", CTLFLAG_RW,
957 	    &rack_probertt_lower_within, 10,
958 	    "If the rtt goes lower within this percentage of the time, go into probe-rtt");
959 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
960 	    SYSCTL_CHILDREN(rack_probertt),
961 	    OID_AUTO, "must_move", CTLFLAG_RW,
962 	    &rack_min_rtt_movement, 250,
963 	    "How much is the minimum movement in rtt to count as a drop for probertt purposes");
964 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
965 	    SYSCTL_CHILDREN(rack_probertt),
966 	    OID_AUTO, "clear_is_cnts", CTLFLAG_RW,
967 	    &rack_probertt_clear_is, 1,
968 	    "Do we clear I/S counts on exiting probe-rtt");
969 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
970 	    SYSCTL_CHILDREN(rack_probertt),
971 	    OID_AUTO, "hbp_extra_drain", CTLFLAG_RW,
972 	    &rack_max_drain_hbp, 1,
973 	    "How many extra drain gpsrtt's do we get in highly buffered paths");
974 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
975 	    SYSCTL_CHILDREN(rack_probertt),
976 	    OID_AUTO, "hbp_threshold", CTLFLAG_RW,
977 	    &rack_hbp_thresh, 3,
978 	    "We are highly buffered if min_rtt_seen / max_rtt_seen > this-threshold");
979 	/* Pacing related sysctls */
980 	rack_pacing = SYSCTL_ADD_NODE(&rack_sysctl_ctx,
981 	    SYSCTL_CHILDREN(rack_sysctl_root),
982 	    OID_AUTO,
983 	    "pacing",
984 	    CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
985 	    "Pacing related Controls");
986 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
987 	    SYSCTL_CHILDREN(rack_pacing),
988 	    OID_AUTO, "pcm_enabled", CTLFLAG_RW,
989 	    &rack_pcm_is_enabled, 1,
990 	    "Do we by default do PCM measurements?");
991 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
992 	    SYSCTL_CHILDREN(rack_pacing),
993 	    OID_AUTO, "pcm_rnds", CTLFLAG_RW,
994 	    &rack_pcm_every_n_rounds, 100,
995 	    "How many rounds before we need to do a PCM measurement");
996 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
997 	    SYSCTL_CHILDREN(rack_pacing),
998 	    OID_AUTO, "pcm_blast", CTLFLAG_RW,
999 	    &rack_pcm_blast, 0,
1000 	    "Blast out the full cwnd/rwnd when doing a PCM measurement");
1001 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
1002 	    SYSCTL_CHILDREN(rack_pacing),
1003 	    OID_AUTO, "rnd_gp_gain", CTLFLAG_RW,
1004 	    &rack_gp_gain_req, 1200,
1005 	    "How much do we have to increase the GP to record the round 1200 = 120.0");
1006 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
1007 	    SYSCTL_CHILDREN(rack_pacing),
1008 	    OID_AUTO, "dgp_out_of_ss_at", CTLFLAG_RW,
1009 	    &rack_rnd_cnt_req, 0x10005,
1010 	    "How many rounds less than rnd_gp_gain will drop us out of SS");
1011 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1012 	    SYSCTL_CHILDREN(rack_pacing),
1013 	    OID_AUTO, "no_timely", CTLFLAG_RW,
1014 	    &rack_timely_off, 0,
1015 	    "Do we not use timely in DGP?");
1016 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1017 	    SYSCTL_CHILDREN(rack_pacing),
1018 	    OID_AUTO, "fillcw", CTLFLAG_RW,
1019 	    &rack_fill_cw_state, 0,
1020 	    "Enable fillcw on new connections (default=0 off)?");
1021 	SYSCTL_ADD_U16(&rack_sysctl_ctx,
1022 	    SYSCTL_CHILDREN(rack_pacing),
1023 	    OID_AUTO, "min_burst", CTLFLAG_RW,
1024 	    &rack_pacing_min_seg, 0,
1025 	    "What is the min burst size for pacing (0 disables)?");
1026 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1027 	    SYSCTL_CHILDREN(rack_pacing),
1028 	    OID_AUTO, "divisor", CTLFLAG_RW,
1029 	    &rack_default_pacing_divisor, 250,
1030 	    "What is the default divisor given to the rl code?");
1031 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1032 	    SYSCTL_CHILDREN(rack_pacing),
1033 	    OID_AUTO, "fillcw_max_mult", CTLFLAG_RW,
1034 	    &rack_bw_multipler, 0,
1035 	    "What is the limit multiplier of the current gp_est that fillcw can increase the b/w too, 200 == 200% (0 = off)?");
1036 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1037 	    SYSCTL_CHILDREN(rack_pacing),
1038 	    OID_AUTO, "max_pace_over", CTLFLAG_RW,
1039 	    &rack_max_per_above, 30,
1040 	    "What is the maximum allowable percentage that we can pace above (so 30 = 130% of our goal)");
1041 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1042 	    SYSCTL_CHILDREN(rack_pacing),
1043 	    OID_AUTO, "allow1mss", CTLFLAG_RW,
1044 	    &rack_pace_one_seg, 0,
1045 	    "Do we allow low b/w pacing of 1MSS instead of two (1.2Meg and less)?");
1046 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1047 	    SYSCTL_CHILDREN(rack_pacing),
1048 	    OID_AUTO, "limit_wsrtt", CTLFLAG_RW,
1049 	    &rack_limit_time_with_srtt, 0,
1050 	    "Do we limit pacing time based on srtt");
1051 	SYSCTL_ADD_U16(&rack_sysctl_ctx,
1052 	    SYSCTL_CHILDREN(rack_pacing),
1053 	    OID_AUTO, "gp_per_ss", CTLFLAG_RW,
1054 	    &rack_per_of_gp_ss, 250,
1055 	    "If non zero, what percentage of goodput to pace at in slow start");
1056 	SYSCTL_ADD_U16(&rack_sysctl_ctx,
1057 	    SYSCTL_CHILDREN(rack_pacing),
1058 	    OID_AUTO, "gp_per_ca", CTLFLAG_RW,
1059 	    &rack_per_of_gp_ca, 150,
1060 	    "If non zero, what percentage of goodput to pace at in congestion avoidance");
1061 	SYSCTL_ADD_U16(&rack_sysctl_ctx,
1062 	    SYSCTL_CHILDREN(rack_pacing),
1063 	    OID_AUTO, "gp_per_rec", CTLFLAG_RW,
1064 	    &rack_per_of_gp_rec, 200,
1065 	    "If non zero, what percentage of goodput to pace at in recovery");
1066 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1067 	    SYSCTL_CHILDREN(rack_pacing),
1068 	    OID_AUTO, "pace_max_seg", CTLFLAG_RW,
1069 	    &rack_hptsi_segments, 40,
1070 	    "What size is the max for TSO segments in pacing and burst mitigation");
1071 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1072 	    SYSCTL_CHILDREN(rack_pacing),
1073 	    OID_AUTO, "burst_reduces", CTLFLAG_RW,
1074 	    &rack_pacing_delay_reduction, 4,
1075 	    "When doing only burst mitigation what is the reduce divisor");
1076 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1077 	    SYSCTL_CHILDREN(rack_sysctl_root),
1078 	    OID_AUTO, "use_pacing", CTLFLAG_RW,
1079 	    &rack_pace_every_seg, 0,
1080 	    "If set we use pacing, if clear we use only the original burst mitigation");
1081 	SYSCTL_ADD_U64(&rack_sysctl_ctx,
1082 	    SYSCTL_CHILDREN(rack_pacing),
1083 	    OID_AUTO, "rate_cap", CTLFLAG_RW,
1084 	    &rack_bw_rate_cap, 0,
1085 	    "If set we apply this value to the absolute rate cap used by pacing");
1086 	SYSCTL_ADD_U64(&rack_sysctl_ctx,
1087 	    SYSCTL_CHILDREN(rack_pacing),
1088 	    OID_AUTO, "fillcw_cap", CTLFLAG_RW,
1089 	    &rack_fillcw_bw_cap, 3750000,
1090 	    "Do we have an absolute cap on the amount of b/w fillcw can specify (0 = no)?");
1091 	SYSCTL_ADD_U8(&rack_sysctl_ctx,
1092 	    SYSCTL_CHILDREN(rack_sysctl_root),
1093 	    OID_AUTO, "req_measure_cnt", CTLFLAG_RW,
1094 	    &rack_req_measurements, 1,
1095 	    "If doing dynamic pacing, how many measurements must be in before we start pacing?");
1096 	/* Hardware pacing */
1097 	rack_hw_pacing = SYSCTL_ADD_NODE(&rack_sysctl_ctx,
1098 	    SYSCTL_CHILDREN(rack_sysctl_root),
1099 	    OID_AUTO,
1100 	    "hdwr_pacing",
1101 	    CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
1102 	    "Pacing related Controls");
1103 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1104 	    SYSCTL_CHILDREN(rack_hw_pacing),
1105 	    OID_AUTO, "rwnd_factor", CTLFLAG_RW,
1106 	    &rack_hw_rwnd_factor, 2,
1107 	    "How many times does snd_wnd need to be bigger than pace_max_seg so we will hold off and get more acks?");
1108 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1109 	    SYSCTL_CHILDREN(rack_hw_pacing),
1110 	    OID_AUTO, "precheck", CTLFLAG_RW,
1111 	    &rack_hw_check_queue, 0,
1112 	    "Do we always precheck the hdwr pacing queue to avoid ENOBUF's?");
1113 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1114 	    SYSCTL_CHILDREN(rack_hw_pacing),
1115 	    OID_AUTO, "pace_enobuf_mult", CTLFLAG_RW,
1116 	    &rack_enobuf_hw_boost_mult, 0,
1117 	    "By how many time_betweens should we boost the pacing time if we see a ENOBUFS?");
1118 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1119 	    SYSCTL_CHILDREN(rack_hw_pacing),
1120 	    OID_AUTO, "pace_enobuf_max", CTLFLAG_RW,
1121 	    &rack_enobuf_hw_max, 2,
1122 	    "What is the max boost the pacing time if we see a ENOBUFS?");
1123 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1124 	    SYSCTL_CHILDREN(rack_hw_pacing),
1125 	    OID_AUTO, "pace_enobuf_min", CTLFLAG_RW,
1126 	    &rack_enobuf_hw_min, 2,
1127 	    "What is the min boost the pacing time if we see a ENOBUFS?");
1128 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1129 	    SYSCTL_CHILDREN(rack_hw_pacing),
1130 	    OID_AUTO, "enable", CTLFLAG_RW,
1131 	    &rack_enable_hw_pacing, 0,
1132 	    "Should RACK attempt to use hw pacing?");
1133 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1134 	    SYSCTL_CHILDREN(rack_hw_pacing),
1135 	    OID_AUTO, "rate_cap", CTLFLAG_RW,
1136 	    &rack_hw_rate_caps, 0,
1137 	    "Does the highest hardware pacing rate cap the rate we will send at??");
1138 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1139 	    SYSCTL_CHILDREN(rack_hw_pacing),
1140 	    OID_AUTO, "uncap_per", CTLFLAG_RW,
1141 	    &rack_hw_rate_cap_per, 0,
1142 	    "If you go over b/w by this amount you will be uncapped (0 = never)");
1143 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1144 	    SYSCTL_CHILDREN(rack_hw_pacing),
1145 	    OID_AUTO, "rate_min", CTLFLAG_RW,
1146 	    &rack_hw_rate_min, 0,
1147 	    "Do we need a minimum estimate of this many bytes per second in order to engage hw pacing?");
1148 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1149 	    SYSCTL_CHILDREN(rack_hw_pacing),
1150 	    OID_AUTO, "rate_to_low", CTLFLAG_RW,
1151 	    &rack_hw_rate_to_low, 0,
1152 	    "If we fall below this rate, dis-engage hw pacing?");
1153 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1154 	    SYSCTL_CHILDREN(rack_hw_pacing),
1155 	    OID_AUTO, "up_only", CTLFLAG_RW,
1156 	    &rack_hw_up_only, 0,
1157 	    "Do we allow hw pacing to lower the rate selected?");
1158 	rack_timely = SYSCTL_ADD_NODE(&rack_sysctl_ctx,
1159 	    SYSCTL_CHILDREN(rack_sysctl_root),
1160 	    OID_AUTO,
1161 	    "timely",
1162 	    CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
1163 	    "Rack Timely RTT Controls");
1164 	/* Timely based GP dynmics */
1165 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1166 	    SYSCTL_CHILDREN(rack_timely),
1167 	    OID_AUTO, "upper", CTLFLAG_RW,
1168 	    &rack_gp_per_bw_mul_up, 2,
1169 	    "Rack timely upper range for equal b/w (in percentage)");
1170 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1171 	    SYSCTL_CHILDREN(rack_timely),
1172 	    OID_AUTO, "lower", CTLFLAG_RW,
1173 	    &rack_gp_per_bw_mul_down, 4,
1174 	    "Rack timely lower range for equal b/w (in percentage)");
1175 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1176 	    SYSCTL_CHILDREN(rack_timely),
1177 	    OID_AUTO, "rtt_max_mul", CTLFLAG_RW,
1178 	    &rack_gp_rtt_maxmul, 3,
1179 	    "Rack timely multiplier of lowest rtt for rtt_max");
1180 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1181 	    SYSCTL_CHILDREN(rack_timely),
1182 	    OID_AUTO, "rtt_min_div", CTLFLAG_RW,
1183 	    &rack_gp_rtt_mindiv, 4,
1184 	    "Rack timely divisor used for rtt + (rtt * mul/divisor) for check for lower rtt");
1185 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1186 	    SYSCTL_CHILDREN(rack_timely),
1187 	    OID_AUTO, "rtt_min_mul", CTLFLAG_RW,
1188 	    &rack_gp_rtt_minmul, 1,
1189 	    "Rack timely multiplier used for rtt + (rtt * mul/divisor) for check for lower rtt");
1190 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1191 	    SYSCTL_CHILDREN(rack_timely),
1192 	    OID_AUTO, "decrease", CTLFLAG_RW,
1193 	    &rack_gp_decrease_per, 80,
1194 	    "Rack timely Beta value 80 = .8 (scaled by 100)");
1195 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1196 	    SYSCTL_CHILDREN(rack_timely),
1197 	    OID_AUTO, "increase", CTLFLAG_RW,
1198 	    &rack_gp_increase_per, 2,
1199 	    "Rack timely increase perentage of our GP multiplication factor");
1200 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1201 	    SYSCTL_CHILDREN(rack_timely),
1202 	    OID_AUTO, "lowerbound", CTLFLAG_RW,
1203 	    &rack_per_lower_bound, 50,
1204 	    "Rack timely lowest percentage we allow GP multiplier to fall to");
1205 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1206 	    SYSCTL_CHILDREN(rack_timely),
1207 	    OID_AUTO, "p5_upper", CTLFLAG_RW,
1208 	    &rack_gain_p5_ub, 250,
1209 	    "Profile 5 upper bound to timely gain");
1210 
1211 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1212 	    SYSCTL_CHILDREN(rack_timely),
1213 	    OID_AUTO, "upperboundss", CTLFLAG_RW,
1214 	    &rack_per_upper_bound_ss, 0,
1215 	    "Rack timely highest percentage we allow GP multiplier in SS to raise to (0 is no upperbound)");
1216 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1217 	    SYSCTL_CHILDREN(rack_timely),
1218 	    OID_AUTO, "upperboundca", CTLFLAG_RW,
1219 	    &rack_per_upper_bound_ca, 0,
1220 	    "Rack timely highest percentage we allow GP multiplier to CA raise to (0 is no upperbound)");
1221 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1222 	    SYSCTL_CHILDREN(rack_timely),
1223 	    OID_AUTO, "dynamicgp", CTLFLAG_RW,
1224 	    &rack_do_dyn_mul, 0,
1225 	    "Rack timely do we enable dynmaic timely goodput by default");
1226 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1227 	    SYSCTL_CHILDREN(rack_timely),
1228 	    OID_AUTO, "no_rec_red", CTLFLAG_RW,
1229 	    &rack_gp_no_rec_chg, 1,
1230 	    "Rack timely do we prohibit the recovery multiplier from being lowered");
1231 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1232 	    SYSCTL_CHILDREN(rack_timely),
1233 	    OID_AUTO, "red_clear_cnt", CTLFLAG_RW,
1234 	    &rack_timely_dec_clear, 6,
1235 	    "Rack timely what threshold do we count to before another boost during b/w decent");
1236 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1237 	    SYSCTL_CHILDREN(rack_timely),
1238 	    OID_AUTO, "max_push_rise", CTLFLAG_RW,
1239 	    &rack_timely_max_push_rise, 3,
1240 	    "Rack timely how many times do we push up with b/w increase");
1241 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1242 	    SYSCTL_CHILDREN(rack_timely),
1243 	    OID_AUTO, "max_push_drop", CTLFLAG_RW,
1244 	    &rack_timely_max_push_drop, 3,
1245 	    "Rack timely how many times do we push back on b/w decent");
1246 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1247 	    SYSCTL_CHILDREN(rack_timely),
1248 	    OID_AUTO, "min_segs", CTLFLAG_RW,
1249 	    &rack_timely_min_segs, 4,
1250 	    "Rack timely when setting the cwnd what is the min num segments");
1251 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1252 	    SYSCTL_CHILDREN(rack_timely),
1253 	    OID_AUTO, "nonstop", CTLFLAG_RW,
1254 	    &rack_timely_no_stopping, 0,
1255 	    "Rack timely don't stop increase");
1256 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1257 	    SYSCTL_CHILDREN(rack_timely),
1258 	    OID_AUTO, "dec_raise_thresh", CTLFLAG_RW,
1259 	    &rack_down_raise_thresh, 100,
1260 	    "If the CA or SS is below this threshold raise on the first 3 b/w lowers (0=always)");
1261 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1262 	    SYSCTL_CHILDREN(rack_timely),
1263 	    OID_AUTO, "bottom_drag_segs", CTLFLAG_RW,
1264 	    &rack_req_segs, 1,
1265 	    "Bottom dragging if not these many segments outstanding and room");
1266 
1267 	/* TLP and Rack related parameters */
1268 	rack_tlp = SYSCTL_ADD_NODE(&rack_sysctl_ctx,
1269 	    SYSCTL_CHILDREN(rack_sysctl_root),
1270 	    OID_AUTO,
1271 	    "tlp",
1272 	    CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
1273 	    "TLP and Rack related Controls");
1274 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1275 	    SYSCTL_CHILDREN(rack_tlp),
1276 	    OID_AUTO, "use_rrr", CTLFLAG_RW,
1277 	    &use_rack_rr, 1,
1278 	    "Do we use Rack Rapid Recovery");
1279 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1280 	    SYSCTL_CHILDREN(rack_tlp),
1281 	    OID_AUTO, "post_rec_labc", CTLFLAG_RW,
1282 	    &rack_max_abc_post_recovery, 2,
1283 	    "Since we do early recovery, do we override the l_abc to a value, if so what?");
1284 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1285 	    SYSCTL_CHILDREN(rack_tlp),
1286 	    OID_AUTO, "nonrxt_use_cr", CTLFLAG_RW,
1287 	    &rack_non_rxt_use_cr, 0,
1288 	    "Do we use ss/ca rate if in recovery we are transmitting a new data chunk");
1289 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1290 	    SYSCTL_CHILDREN(rack_tlp),
1291 	    OID_AUTO, "tlpmethod", CTLFLAG_RW,
1292 	    &rack_tlp_threshold_use, TLP_USE_TWO_ONE,
1293 	    "What method do we do for TLP time calc 0=no-de-ack-comp, 1=ID, 2=2.1, 3=2.2");
1294 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1295 	    SYSCTL_CHILDREN(rack_tlp),
1296 	    OID_AUTO, "limit", CTLFLAG_RW,
1297 	    &rack_tlp_limit, 2,
1298 	    "How many TLP's can be sent without sending new data");
1299 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1300 	    SYSCTL_CHILDREN(rack_tlp),
1301 	    OID_AUTO, "use_greater", CTLFLAG_RW,
1302 	    &rack_tlp_use_greater, 1,
1303 	    "Should we use the rack_rtt time if its greater than srtt");
1304 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1305 	    SYSCTL_CHILDREN(rack_tlp),
1306 	    OID_AUTO, "tlpminto", CTLFLAG_RW,
1307 	    &rack_tlp_min, 10000,
1308 	    "TLP minimum timeout per the specification (in microseconds)");
1309 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1310 	    SYSCTL_CHILDREN(rack_tlp),
1311 	    OID_AUTO, "send_oldest", CTLFLAG_RW,
1312 	    &rack_always_send_oldest, 0,
1313 	    "Should we always send the oldest TLP and RACK-TLP");
1314 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1315 	    SYSCTL_CHILDREN(rack_tlp),
1316 	    OID_AUTO, "tlp_cwnd_flag", CTLFLAG_RW,
1317 	    &rack_lower_cwnd_at_tlp, 0,
1318 	    "When a TLP completes a retran should we enter recovery");
1319 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1320 	    SYSCTL_CHILDREN(rack_tlp),
1321 	    OID_AUTO, "reorder_thresh", CTLFLAG_RW,
1322 	    &rack_reorder_thresh, 2,
1323 	    "What factor for rack will be added when seeing reordering (shift right)");
1324 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1325 	    SYSCTL_CHILDREN(rack_tlp),
1326 	    OID_AUTO, "rtt_tlp_thresh", CTLFLAG_RW,
1327 	    &rack_tlp_thresh, 1,
1328 	    "What divisor for TLP rtt/retran will be added (1=rtt, 2=1/2 rtt etc)");
1329 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1330 	    SYSCTL_CHILDREN(rack_tlp),
1331 	    OID_AUTO, "reorder_fade", CTLFLAG_RW,
1332 	    &rack_reorder_fade, 60000000,
1333 	    "Does reorder detection fade, if so how many microseconds (0 means never)");
1334 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1335 	    SYSCTL_CHILDREN(rack_tlp),
1336 	    OID_AUTO, "pktdelay", CTLFLAG_RW,
1337 	    &rack_pkt_delay, 1000,
1338 	    "Extra RACK time (in microseconds) besides reordering thresh");
1339 
1340 	/* Timer related controls */
1341 	rack_timers = SYSCTL_ADD_NODE(&rack_sysctl_ctx,
1342 	    SYSCTL_CHILDREN(rack_sysctl_root),
1343 	    OID_AUTO,
1344 	    "timers",
1345 	    CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
1346 	    "Timer related controls");
1347 	SYSCTL_ADD_U8(&rack_sysctl_ctx,
1348 	    SYSCTL_CHILDREN(rack_timers),
1349 	    OID_AUTO, "reset_ssth_rec_rto", CTLFLAG_RW,
1350 	    &rack_ssthresh_rest_rto_rec, 0,
1351 	    "When doing recovery -> rto -> recovery do we reset SSthresh?");
1352 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
1353 	    SYSCTL_CHILDREN(rack_timers),
1354 	    OID_AUTO, "scoreboard_thresh", CTLFLAG_RW,
1355 	    &rack_rxt_scoreboard_clear_thresh, 2,
1356 	    "How many RTO's are allowed before we clear the scoreboard");
1357 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
1358 	    SYSCTL_CHILDREN(rack_timers),
1359 	    OID_AUTO, "honor_hpts_min", CTLFLAG_RW,
1360 	    &rack_honors_hpts_min_to, 1,
1361 	    "Do rack pacing timers honor hpts min timeout");
1362 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
1363 	    SYSCTL_CHILDREN(rack_timers),
1364 	    OID_AUTO, "hpts_max_reduce", CTLFLAG_RW,
1365 	    &rack_max_reduce, 10,
1366 	    "Max percentage we will reduce pacing delay by for pacing when we are behind");
1367 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
1368 	    SYSCTL_CHILDREN(rack_timers),
1369 	    OID_AUTO, "persmin", CTLFLAG_RW,
1370 	    &rack_persist_min, 250000,
1371 	    "What is the minimum time in microseconds between persists");
1372 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
1373 	    SYSCTL_CHILDREN(rack_timers),
1374 	    OID_AUTO, "persmax", CTLFLAG_RW,
1375 	    &rack_persist_max, 2000000,
1376 	    "What is the largest delay in microseconds between persists");
1377 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1378 	    SYSCTL_CHILDREN(rack_timers),
1379 	    OID_AUTO, "delayed_ack", CTLFLAG_RW,
1380 	    &rack_delayed_ack_time, 40000,
1381 	    "Delayed ack time (40ms in microseconds)");
1382 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1383 	    SYSCTL_CHILDREN(rack_timers),
1384 	    OID_AUTO, "minrto", CTLFLAG_RW,
1385 	    &rack_rto_min, 30000,
1386 	    "Minimum RTO in microseconds -- set with caution below 1000 due to TLP");
1387 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1388 	    SYSCTL_CHILDREN(rack_timers),
1389 	    OID_AUTO, "maxrto", CTLFLAG_RW,
1390 	    &rack_rto_max, 4000000,
1391 	    "Maximum RTO in microseconds -- should be at least as large as min_rto");
1392 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1393 	    SYSCTL_CHILDREN(rack_timers),
1394 	    OID_AUTO, "minto", CTLFLAG_RW,
1395 	    &rack_min_to, 1000,
1396 	    "Minimum rack timeout in microseconds");
1397 	/* Measure controls */
1398 	rack_measure = SYSCTL_ADD_NODE(&rack_sysctl_ctx,
1399 	    SYSCTL_CHILDREN(rack_sysctl_root),
1400 	    OID_AUTO,
1401 	    "measure",
1402 	    CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
1403 	    "Measure related controls");
1404 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1405 	    SYSCTL_CHILDREN(rack_measure),
1406 	    OID_AUTO, "wma_divisor", CTLFLAG_RW,
1407 	    &rack_wma_divisor, 8,
1408 	    "When doing b/w calculation what is the  divisor for the WMA");
1409 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1410 	    SYSCTL_CHILDREN(rack_measure),
1411 	    OID_AUTO, "end_cwnd", CTLFLAG_RW,
1412 	    &rack_cwnd_block_ends_measure, 0,
1413 	    "Does a cwnd just-return end the measurement window (app limited)");
1414 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1415 	    SYSCTL_CHILDREN(rack_measure),
1416 	    OID_AUTO, "end_rwnd", CTLFLAG_RW,
1417 	    &rack_rwnd_block_ends_measure, 0,
1418 	    "Does an rwnd just-return end the measurement window (app limited -- not persists)");
1419 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
1420 	    SYSCTL_CHILDREN(rack_measure),
1421 	    OID_AUTO, "min_target", CTLFLAG_RW,
1422 	    &rack_def_data_window, 20,
1423 	    "What is the minimum target window (in mss) for a GP measurements");
1424 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
1425 	    SYSCTL_CHILDREN(rack_measure),
1426 	    OID_AUTO, "goal_bdp", CTLFLAG_RW,
1427 	    &rack_goal_bdp, 2,
1428 	    "What is the goal BDP to measure");
1429 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
1430 	    SYSCTL_CHILDREN(rack_measure),
1431 	    OID_AUTO, "min_srtts", CTLFLAG_RW,
1432 	    &rack_min_srtts, 1,
1433 	    "What is the goal BDP to measure");
1434 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
1435 	    SYSCTL_CHILDREN(rack_measure),
1436 	    OID_AUTO, "min_measure_tim", CTLFLAG_RW,
1437 	    &rack_min_measure_usec, 0,
1438 	    "What is the Minimum time time for a measurement if 0, this is off");
1439 	/* Features */
1440 	rack_features = SYSCTL_ADD_NODE(&rack_sysctl_ctx,
1441 	    SYSCTL_CHILDREN(rack_sysctl_root),
1442 	    OID_AUTO,
1443 	    "features",
1444 	    CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
1445 	    "Feature controls");
1446 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1447 	    SYSCTL_CHILDREN(rack_features),
1448 	    OID_AUTO, "hybrid_set_maxseg", CTLFLAG_RW,
1449 	    &rack_hybrid_allow_set_maxseg, 0,
1450 	    "Should hybrid pacing allow the setmss command");
1451 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1452 	    SYSCTL_CHILDREN(rack_features),
1453 	    OID_AUTO, "cmpack", CTLFLAG_RW,
1454 	    &rack_use_cmp_acks, 1,
1455 	    "Should RACK have LRO send compressed acks");
1456 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1457 	    SYSCTL_CHILDREN(rack_features),
1458 	    OID_AUTO, "fsb", CTLFLAG_RW,
1459 	    &rack_use_fsb, 1,
1460 	    "Should RACK use the fast send block?");
1461 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1462 	    SYSCTL_CHILDREN(rack_features),
1463 	    OID_AUTO, "rfo", CTLFLAG_RW,
1464 	    &rack_use_rfo, 1,
1465 	    "Should RACK use rack_fast_output()?");
1466 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1467 	    SYSCTL_CHILDREN(rack_features),
1468 	    OID_AUTO, "rsmrfo", CTLFLAG_RW,
1469 	    &rack_use_rsm_rfo, 1,
1470 	    "Should RACK use rack_fast_rsm_output()?");
1471 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1472 	    SYSCTL_CHILDREN(rack_features),
1473 	    OID_AUTO, "non_paced_lro_queue", CTLFLAG_RW,
1474 	    &rack_enable_mqueue_for_nonpaced, 0,
1475 	    "Should RACK use mbuf queuing for non-paced connections");
1476 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1477 	    SYSCTL_CHILDREN(rack_features),
1478 	    OID_AUTO, "hystartplusplus", CTLFLAG_RW,
1479 	    &rack_do_hystart, 0,
1480 	    "Should RACK enable HyStart++ on connections?");
1481 	/* Misc rack controls */
1482 	rack_misc = SYSCTL_ADD_NODE(&rack_sysctl_ctx,
1483 	    SYSCTL_CHILDREN(rack_sysctl_root),
1484 	    OID_AUTO,
1485 	    "misc",
1486 	    CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
1487 	    "Misc related controls");
1488 #ifdef TCP_ACCOUNTING
1489 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1490 	    SYSCTL_CHILDREN(rack_misc),
1491 	    OID_AUTO, "tcp_acct", CTLFLAG_RW,
1492 	    &rack_tcp_accounting, 0,
1493 	    "Should we turn on TCP accounting for all rack sessions?");
1494 #endif
1495 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1496 	    SYSCTL_CHILDREN(rack_misc),
1497 	    OID_AUTO, "dnd", CTLFLAG_RW,
1498 	    &rack_dnd_default, 0,
1499 	    "Do not disturb default for rack_rrr = 3");
1500 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1501 	    SYSCTL_CHILDREN(rack_misc),
1502 	    OID_AUTO, "rxt_controls", CTLFLAG_RW,
1503 	    &rack_rxt_controls, 0,
1504 	    "Retransmit sending size controls (valid  values 0, 1, 2 default=1)?");
1505 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1506 	    SYSCTL_CHILDREN(rack_misc),
1507 	    OID_AUTO, "rack_hibeta", CTLFLAG_RW,
1508 	    &rack_hibeta_setting, 0,
1509 	    "Do we ue a high beta (80 instead of 50)?");
1510 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1511 	    SYSCTL_CHILDREN(rack_misc),
1512 	    OID_AUTO, "apply_rtt_with_low_conf", CTLFLAG_RW,
1513 	    &rack_apply_rtt_with_reduced_conf, 0,
1514 	    "When a persist or keep-alive probe is not answered do we calculate rtt on subsequent answers?");
1515 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1516 	    SYSCTL_CHILDREN(rack_misc),
1517 	    OID_AUTO, "rack_dsack_ctl", CTLFLAG_RW,
1518 	    &rack_dsack_std_based, 3,
1519 	    "How do we process dsack with respect to rack timers, bit field, 3 is standards based?");
1520 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1521 	    SYSCTL_CHILDREN(rack_misc),
1522 	    OID_AUTO, "prr_addback_max", CTLFLAG_RW,
1523 	    &rack_prr_addbackmax, 2,
1524 	    "What is the maximum number of MSS we allow to be added back if prr can't send all its data?");
1525 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1526 	    SYSCTL_CHILDREN(rack_misc),
1527 	    OID_AUTO, "stats_gets_ms", CTLFLAG_RW,
1528 	    &rack_stats_gets_ms_rtt, 1,
1529 	    "What do we feed the stats framework (1 = ms_rtt, 0 = us_rtt, 2 = ms_rtt from hdwr, > 2 usec rtt from hdwr)?");
1530 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1531 	    SYSCTL_CHILDREN(rack_misc),
1532 	    OID_AUTO, "clientlowbuf", CTLFLAG_RW,
1533 	    &rack_client_low_buf, 0,
1534 	    "Client low buffer level (below this we are more aggressive in DGP exiting recovery (0 = off)?");
1535 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1536 	    SYSCTL_CHILDREN(rack_misc),
1537 	    OID_AUTO, "defprofile", CTLFLAG_RW,
1538 	    &rack_def_profile, 0,
1539 	    "Should RACK use a default profile (0=no, num == profile num)?");
1540 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1541 	    SYSCTL_CHILDREN(rack_misc),
1542 	    OID_AUTO, "shared_cwnd", CTLFLAG_RW,
1543 	    &rack_enable_shared_cwnd, 1,
1544 	    "Should RACK try to use the shared cwnd on connections where allowed");
1545 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1546 	    SYSCTL_CHILDREN(rack_misc),
1547 	    OID_AUTO, "limits_on_scwnd", CTLFLAG_RW,
1548 	    &rack_limits_scwnd, 1,
1549 	    "Should RACK place low end time limits on the shared cwnd feature");
1550 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1551 	    SYSCTL_CHILDREN(rack_misc),
1552 	    OID_AUTO, "no_prr", CTLFLAG_RW,
1553 	    &rack_disable_prr, 0,
1554 	    "Should RACK not use prr and only pace (must have pacing on)");
1555 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1556 	    SYSCTL_CHILDREN(rack_misc),
1557 	    OID_AUTO, "bb_verbose", CTLFLAG_RW,
1558 	    &rack_verbose_logging, 0,
1559 	    "Should RACK black box logging be verbose");
1560 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1561 	    SYSCTL_CHILDREN(rack_misc),
1562 	    OID_AUTO, "data_after_close", CTLFLAG_RW,
1563 	    &rack_ignore_data_after_close, 1,
1564 	    "Do we hold off sending a RST until all pending data is ack'd");
1565 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1566 	    SYSCTL_CHILDREN(rack_misc),
1567 	    OID_AUTO, "no_sack_needed", CTLFLAG_RW,
1568 	    &rack_sack_not_required, 1,
1569 	    "Do we allow rack to run on connections not supporting SACK");
1570 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1571 	    SYSCTL_CHILDREN(rack_misc),
1572 	    OID_AUTO, "prr_sendalot", CTLFLAG_RW,
1573 	    &rack_send_a_lot_in_prr, 1,
1574 	    "Send a lot in prr");
1575 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1576 	    SYSCTL_CHILDREN(rack_misc),
1577 	    OID_AUTO, "autoscale", CTLFLAG_RW,
1578 	    &rack_autosndbuf_inc, 20,
1579 	    "What percentage should rack scale up its snd buffer by?");
1580 
1581 	/* Counters */
1582 	rack_total_bytes = counter_u64_alloc(M_WAITOK);
1583 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1584 	    SYSCTL_CHILDREN(rack_counters),
1585 	    OID_AUTO, "totalbytes", CTLFLAG_RD,
1586 	    &rack_total_bytes,
1587 	    "Total number of bytes sent");
1588 	rack_fto_send = counter_u64_alloc(M_WAITOK);
1589 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1590 	    SYSCTL_CHILDREN(rack_counters),
1591 	    OID_AUTO, "fto_send", CTLFLAG_RD,
1592 	    &rack_fto_send, "Total number of rack_fast_output sends");
1593 	rack_fto_rsm_send = counter_u64_alloc(M_WAITOK);
1594 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1595 	    SYSCTL_CHILDREN(rack_counters),
1596 	    OID_AUTO, "fto_rsm_send", CTLFLAG_RD,
1597 	    &rack_fto_rsm_send, "Total number of rack_fast_rsm_output sends");
1598 	rack_nfto_resend = counter_u64_alloc(M_WAITOK);
1599 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1600 	    SYSCTL_CHILDREN(rack_counters),
1601 	    OID_AUTO, "nfto_resend", CTLFLAG_RD,
1602 	    &rack_nfto_resend, "Total number of rack_output retransmissions");
1603 	rack_non_fto_send = counter_u64_alloc(M_WAITOK);
1604 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1605 	    SYSCTL_CHILDREN(rack_counters),
1606 	    OID_AUTO, "nfto_send", CTLFLAG_RD,
1607 	    &rack_non_fto_send, "Total number of rack_output first sends");
1608 	rack_extended_rfo = counter_u64_alloc(M_WAITOK);
1609 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1610 	    SYSCTL_CHILDREN(rack_counters),
1611 	    OID_AUTO, "rfo_extended", CTLFLAG_RD,
1612 	    &rack_extended_rfo, "Total number of times we extended rfo");
1613 
1614 	rack_hw_pace_init_fail = counter_u64_alloc(M_WAITOK);
1615 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1616 	    SYSCTL_CHILDREN(rack_counters),
1617 	    OID_AUTO, "hwpace_init_fail", CTLFLAG_RD,
1618 	    &rack_hw_pace_init_fail, "Total number of times we failed to initialize hw pacing");
1619 	rack_hw_pace_lost = counter_u64_alloc(M_WAITOK);
1620 
1621 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1622 	    SYSCTL_CHILDREN(rack_counters),
1623 	    OID_AUTO, "hwpace_lost", CTLFLAG_RD,
1624 	    &rack_hw_pace_lost, "Total number of times we failed to initialize hw pacing");
1625 	rack_tlp_tot = counter_u64_alloc(M_WAITOK);
1626 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1627 	    SYSCTL_CHILDREN(rack_counters),
1628 	    OID_AUTO, "tlp_to_total", CTLFLAG_RD,
1629 	    &rack_tlp_tot,
1630 	    "Total number of tail loss probe expirations");
1631 	rack_tlp_newdata = counter_u64_alloc(M_WAITOK);
1632 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1633 	    SYSCTL_CHILDREN(rack_counters),
1634 	    OID_AUTO, "tlp_new", CTLFLAG_RD,
1635 	    &rack_tlp_newdata,
1636 	    "Total number of tail loss probe sending new data");
1637 	rack_tlp_retran = counter_u64_alloc(M_WAITOK);
1638 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1639 	    SYSCTL_CHILDREN(rack_counters),
1640 	    OID_AUTO, "tlp_retran", CTLFLAG_RD,
1641 	    &rack_tlp_retran,
1642 	    "Total number of tail loss probe sending retransmitted data");
1643 	rack_tlp_retran_bytes = counter_u64_alloc(M_WAITOK);
1644 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1645 	    SYSCTL_CHILDREN(rack_counters),
1646 	    OID_AUTO, "tlp_retran_bytes", CTLFLAG_RD,
1647 	    &rack_tlp_retran_bytes,
1648 	    "Total bytes of tail loss probe sending retransmitted data");
1649 	rack_to_tot = counter_u64_alloc(M_WAITOK);
1650 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1651 	    SYSCTL_CHILDREN(rack_counters),
1652 	    OID_AUTO, "rack_to_tot", CTLFLAG_RD,
1653 	    &rack_to_tot,
1654 	    "Total number of times the rack to expired");
1655 	rack_saw_enobuf = counter_u64_alloc(M_WAITOK);
1656 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1657 	    SYSCTL_CHILDREN(rack_counters),
1658 	    OID_AUTO, "saw_enobufs", CTLFLAG_RD,
1659 	    &rack_saw_enobuf,
1660 	    "Total number of times a sends returned enobuf for non-hdwr paced connections");
1661 	rack_saw_enobuf_hw = counter_u64_alloc(M_WAITOK);
1662 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1663 	    SYSCTL_CHILDREN(rack_counters),
1664 	    OID_AUTO, "saw_enobufs_hw", CTLFLAG_RD,
1665 	    &rack_saw_enobuf_hw,
1666 	    "Total number of times a send returned enobuf for hdwr paced connections");
1667 	rack_saw_enetunreach = counter_u64_alloc(M_WAITOK);
1668 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1669 	    SYSCTL_CHILDREN(rack_counters),
1670 	    OID_AUTO, "saw_enetunreach", CTLFLAG_RD,
1671 	    &rack_saw_enetunreach,
1672 	    "Total number of times a send received a enetunreachable");
1673 	rack_hot_alloc = counter_u64_alloc(M_WAITOK);
1674 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1675 	    SYSCTL_CHILDREN(rack_counters),
1676 	    OID_AUTO, "alloc_hot", CTLFLAG_RD,
1677 	    &rack_hot_alloc,
1678 	    "Total allocations from the top of our list");
1679 	rack_to_alloc = counter_u64_alloc(M_WAITOK);
1680 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1681 	    SYSCTL_CHILDREN(rack_counters),
1682 	    OID_AUTO, "allocs", CTLFLAG_RD,
1683 	    &rack_to_alloc,
1684 	    "Total allocations of tracking structures");
1685 	rack_to_alloc_hard = counter_u64_alloc(M_WAITOK);
1686 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1687 	    SYSCTL_CHILDREN(rack_counters),
1688 	    OID_AUTO, "allochard", CTLFLAG_RD,
1689 	    &rack_to_alloc_hard,
1690 	    "Total allocations done with sleeping the hard way");
1691 	rack_to_alloc_emerg = counter_u64_alloc(M_WAITOK);
1692 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1693 	    SYSCTL_CHILDREN(rack_counters),
1694 	    OID_AUTO, "allocemerg", CTLFLAG_RD,
1695 	    &rack_to_alloc_emerg,
1696 	    "Total allocations done from emergency cache");
1697 	rack_to_alloc_limited = counter_u64_alloc(M_WAITOK);
1698 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1699 	    SYSCTL_CHILDREN(rack_counters),
1700 	    OID_AUTO, "alloc_limited", CTLFLAG_RD,
1701 	    &rack_to_alloc_limited,
1702 	    "Total allocations dropped due to limit");
1703 	rack_alloc_limited_conns = counter_u64_alloc(M_WAITOK);
1704 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1705 	    SYSCTL_CHILDREN(rack_counters),
1706 	    OID_AUTO, "alloc_limited_conns", CTLFLAG_RD,
1707 	    &rack_alloc_limited_conns,
1708 	    "Connections with allocations dropped due to limit");
1709 	rack_split_limited = counter_u64_alloc(M_WAITOK);
1710 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1711 	    SYSCTL_CHILDREN(rack_counters),
1712 	    OID_AUTO, "split_limited", CTLFLAG_RD,
1713 	    &rack_split_limited,
1714 	    "Split allocations dropped due to limit");
1715 	rack_rxt_clamps_cwnd = counter_u64_alloc(M_WAITOK);
1716 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1717 	    SYSCTL_CHILDREN(rack_counters),
1718 	    OID_AUTO, "rxt_clamps_cwnd", CTLFLAG_RD,
1719 	    &rack_rxt_clamps_cwnd,
1720 	    "Number of times that excessive rxt clamped the cwnd down");
1721 	rack_rxt_clamps_cwnd_uniq = counter_u64_alloc(M_WAITOK);
1722 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1723 	    SYSCTL_CHILDREN(rack_counters),
1724 	    OID_AUTO, "rxt_clamps_cwnd_uniq", CTLFLAG_RD,
1725 	    &rack_rxt_clamps_cwnd_uniq,
1726 	    "Number of connections that have had excessive rxt clamped the cwnd down");
1727 	rack_persists_sends = counter_u64_alloc(M_WAITOK);
1728 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1729 	    SYSCTL_CHILDREN(rack_counters),
1730 	    OID_AUTO, "persist_sends", CTLFLAG_RD,
1731 	    &rack_persists_sends,
1732 	    "Number of times we sent a persist probe");
1733 	rack_persists_acks = counter_u64_alloc(M_WAITOK);
1734 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1735 	    SYSCTL_CHILDREN(rack_counters),
1736 	    OID_AUTO, "persist_acks", CTLFLAG_RD,
1737 	    &rack_persists_acks,
1738 	    "Number of times a persist probe was acked");
1739 	rack_persists_loss = counter_u64_alloc(M_WAITOK);
1740 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1741 	    SYSCTL_CHILDREN(rack_counters),
1742 	    OID_AUTO, "persist_loss", CTLFLAG_RD,
1743 	    &rack_persists_loss,
1744 	    "Number of times we detected a lost persist probe (no ack)");
1745 	rack_persists_lost_ends = counter_u64_alloc(M_WAITOK);
1746 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1747 	    SYSCTL_CHILDREN(rack_counters),
1748 	    OID_AUTO, "persist_loss_ends", CTLFLAG_RD,
1749 	    &rack_persists_lost_ends,
1750 	    "Number of lost persist probe (no ack) that the run ended with a PERSIST abort");
1751 #ifdef INVARIANTS
1752 	rack_adjust_map_bw = counter_u64_alloc(M_WAITOK);
1753 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1754 	    SYSCTL_CHILDREN(rack_counters),
1755 	    OID_AUTO, "map_adjust_req", CTLFLAG_RD,
1756 	    &rack_adjust_map_bw,
1757 	    "Number of times we hit the case where the sb went up and down on a sendmap entry");
1758 #endif
1759 	rack_multi_single_eq = counter_u64_alloc(M_WAITOK);
1760 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1761 	    SYSCTL_CHILDREN(rack_counters),
1762 	    OID_AUTO, "cmp_ack_equiv", CTLFLAG_RD,
1763 	    &rack_multi_single_eq,
1764 	    "Number of compressed acks total represented");
1765 	rack_proc_non_comp_ack = counter_u64_alloc(M_WAITOK);
1766 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1767 	    SYSCTL_CHILDREN(rack_counters),
1768 	    OID_AUTO, "cmp_ack_not", CTLFLAG_RD,
1769 	    &rack_proc_non_comp_ack,
1770 	    "Number of non compresseds acks that we processed");
1771 
1772 
1773 	rack_sack_proc_all = counter_u64_alloc(M_WAITOK);
1774 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1775 	    SYSCTL_CHILDREN(rack_counters),
1776 	    OID_AUTO, "sack_long", CTLFLAG_RD,
1777 	    &rack_sack_proc_all,
1778 	    "Total times we had to walk whole list for sack processing");
1779 	rack_sack_proc_restart = counter_u64_alloc(M_WAITOK);
1780 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1781 	    SYSCTL_CHILDREN(rack_counters),
1782 	    OID_AUTO, "sack_restart", CTLFLAG_RD,
1783 	    &rack_sack_proc_restart,
1784 	    "Total times we had to walk whole list due to a restart");
1785 	rack_sack_proc_short = counter_u64_alloc(M_WAITOK);
1786 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1787 	    SYSCTL_CHILDREN(rack_counters),
1788 	    OID_AUTO, "sack_short", CTLFLAG_RD,
1789 	    &rack_sack_proc_short,
1790 	    "Total times we took shortcut for sack processing");
1791 	rack_input_idle_reduces = counter_u64_alloc(M_WAITOK);
1792 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1793 	    SYSCTL_CHILDREN(rack_counters),
1794 	    OID_AUTO, "idle_reduce_oninput", CTLFLAG_RD,
1795 	    &rack_input_idle_reduces,
1796 	    "Total number of idle reductions on input");
1797 	rack_collapsed_win_seen = counter_u64_alloc(M_WAITOK);
1798 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1799 	    SYSCTL_CHILDREN(rack_counters),
1800 	    OID_AUTO, "collapsed_win_seen", CTLFLAG_RD,
1801 	    &rack_collapsed_win_seen,
1802 	    "Total number of collapsed window events seen (where our window shrinks)");
1803 
1804 	rack_collapsed_win = counter_u64_alloc(M_WAITOK);
1805 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1806 	    SYSCTL_CHILDREN(rack_counters),
1807 	    OID_AUTO, "collapsed_win", CTLFLAG_RD,
1808 	    &rack_collapsed_win,
1809 	    "Total number of collapsed window events where we mark packets");
1810 	rack_collapsed_win_rxt = counter_u64_alloc(M_WAITOK);
1811 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1812 	    SYSCTL_CHILDREN(rack_counters),
1813 	    OID_AUTO, "collapsed_win_rxt", CTLFLAG_RD,
1814 	    &rack_collapsed_win_rxt,
1815 	    "Total number of packets that were retransmitted");
1816 	rack_collapsed_win_rxt_bytes = counter_u64_alloc(M_WAITOK);
1817 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1818 	    SYSCTL_CHILDREN(rack_counters),
1819 	    OID_AUTO, "collapsed_win_bytes", CTLFLAG_RD,
1820 	    &rack_collapsed_win_rxt_bytes,
1821 	    "Total number of bytes that were retransmitted");
1822 	rack_try_scwnd = counter_u64_alloc(M_WAITOK);
1823 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1824 	    SYSCTL_CHILDREN(rack_counters),
1825 	    OID_AUTO, "tried_scwnd", CTLFLAG_RD,
1826 	    &rack_try_scwnd,
1827 	    "Total number of scwnd attempts");
1828 	COUNTER_ARRAY_ALLOC(rack_out_size, TCP_MSS_ACCT_SIZE, M_WAITOK);
1829 	SYSCTL_ADD_COUNTER_U64_ARRAY(&rack_sysctl_ctx, SYSCTL_CHILDREN(rack_sysctl_root),
1830 	    OID_AUTO, "outsize", CTLFLAG_RD,
1831 	    rack_out_size, TCP_MSS_ACCT_SIZE, "MSS send sizes");
1832 	COUNTER_ARRAY_ALLOC(rack_opts_arry, RACK_OPTS_SIZE, M_WAITOK);
1833 	SYSCTL_ADD_COUNTER_U64_ARRAY(&rack_sysctl_ctx, SYSCTL_CHILDREN(rack_sysctl_root),
1834 	    OID_AUTO, "opts", CTLFLAG_RD,
1835 	    rack_opts_arry, RACK_OPTS_SIZE, "RACK Option Stats");
1836 	SYSCTL_ADD_PROC(&rack_sysctl_ctx,
1837 	    SYSCTL_CHILDREN(rack_sysctl_root),
1838 	    OID_AUTO, "clear", CTLTYPE_UINT | CTLFLAG_RW | CTLFLAG_MPSAFE,
1839 	    &rack_clear_counter, 0, sysctl_rack_clear, "IU", "Clear counters");
1840 }
1841 
1842 static uint32_t
1843 rc_init_window(struct tcp_rack *rack)
1844 {
1845 	return (tcp_compute_initwnd(tcp_maxseg(rack->rc_tp)));
1846 
1847 }
1848 
1849 static uint64_t
1850 rack_get_fixed_pacing_bw(struct tcp_rack *rack)
1851 {
1852 	if (IN_FASTRECOVERY(rack->rc_tp->t_flags))
1853 		return (rack->r_ctl.rc_fixed_pacing_rate_rec);
1854 	else if (rack->r_ctl.cwnd_to_use < rack->rc_tp->snd_ssthresh)
1855 		return (rack->r_ctl.rc_fixed_pacing_rate_ss);
1856 	else
1857 		return (rack->r_ctl.rc_fixed_pacing_rate_ca);
1858 }
1859 
1860 static void
1861 rack_log_hybrid_bw(struct tcp_rack *rack, uint32_t seq, uint64_t cbw, uint64_t tim,
1862 	uint64_t data, uint8_t mod, uint16_t aux,
1863 	struct tcp_sendfile_track *cur, int line)
1864 {
1865 #ifdef TCP_REQUEST_TRK
1866 	int do_log = 0;
1867 
1868 	/*
1869 	 * The rate cap one is noisy and only should come out when normal BB logging
1870 	 * is enabled, the other logs (not RATE_CAP and NOT CAP_CALC) only come out
1871 	 * once per chunk and make up the BBpoint that can be turned on by the client.
1872 	 */
1873 	if ((mod == HYBRID_LOG_RATE_CAP) || (mod == HYBRID_LOG_CAP_CALC)) {
1874 		/*
1875 		 * The very noisy two need to only come out when
1876 		 * we have verbose logging on.
1877 		 */
1878 		if (rack_verbose_logging != 0)
1879 			do_log = tcp_bblogging_on(rack->rc_tp);
1880 		else
1881 			do_log = 0;
1882 	} else if (mod != HYBRID_LOG_BW_MEASURE) {
1883 		/*
1884 		 * All other less noisy logs here except the measure which
1885 		 * also needs to come out on the point and the log.
1886 		 */
1887 		do_log = tcp_bblogging_on(rack->rc_tp);
1888 	} else {
1889 		do_log = tcp_bblogging_point_on(rack->rc_tp, TCP_BBPOINT_REQ_LEVEL_LOGGING);
1890 	}
1891 
1892 	if (do_log) {
1893 		union tcp_log_stackspecific log;
1894 		struct timeval tv;
1895 		uint64_t lt_bw;
1896 
1897 		/* Convert our ms to a microsecond */
1898 		memset(&log, 0, sizeof(log));
1899 
1900 		log.u_bbr.cwnd_gain = line;
1901 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
1902 		log.u_bbr.rttProp = tim;
1903 		log.u_bbr.bw_inuse = cbw;
1904 		log.u_bbr.delRate = rack_get_gp_est(rack);
1905 		lt_bw = rack_get_lt_bw(rack);
1906 		log.u_bbr.flex1 = seq;
1907 		log.u_bbr.pacing_gain = aux;
1908 		/* lt_bw = < flex3 | flex2 > */
1909 		log.u_bbr.flex2 = (uint32_t)(lt_bw & 0x00000000ffffffff);
1910 		log.u_bbr.flex3 = (uint32_t)((lt_bw >> 32) & 0x00000000ffffffff);
1911 		/* Record the last obtained us rtt in inflight */
1912 		if (cur == NULL) {
1913 			/* Make sure we are looking at the right log if an overide comes in */
1914 			cur = rack->r_ctl.rc_last_sft;
1915 		}
1916 		if (rack->r_ctl.rack_rs.rs_flags != RACK_RTT_EMPTY)
1917 			log.u_bbr.inflight = rack->r_ctl.rack_rs.rs_us_rtt;
1918 		else {
1919 			/* Use the last known rtt i.e. the rack-rtt */
1920 			log.u_bbr.inflight = rack->rc_rack_rtt;
1921 		}
1922 		if (cur != NULL) {
1923 			uint64_t off;
1924 
1925 			log.u_bbr.cur_del_rate = cur->deadline;
1926 			if ((mod == HYBRID_LOG_RATE_CAP) || (mod == HYBRID_LOG_CAP_CALC)) {
1927 				/* start = < lost | pkt_epoch > */
1928 				log.u_bbr.pkt_epoch = (uint32_t)(cur->start & 0x00000000ffffffff);
1929 				log.u_bbr.lost = (uint32_t)((cur->start >> 32) & 0x00000000ffffffff);
1930 				log.u_bbr.flex6 = cur->start_seq;
1931 				log.u_bbr.pkts_out = cur->end_seq;
1932 			} else {
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 				/* end = < pkts_out | flex6 > */
1937 				log.u_bbr.flex6 = (uint32_t)(cur->end & 0x00000000ffffffff);
1938 				log.u_bbr.pkts_out = (uint32_t)((cur->end >> 32) & 0x00000000ffffffff);
1939 			}
1940 			/* first_send = <lt_epoch | epoch> */
1941 			log.u_bbr.epoch = (uint32_t)(cur->first_send & 0x00000000ffffffff);
1942 			log.u_bbr.lt_epoch = (uint32_t)((cur->first_send >> 32) & 0x00000000ffffffff);
1943 			/* localtime = <delivered | applimited>*/
1944 			log.u_bbr.applimited = (uint32_t)(cur->localtime & 0x00000000ffffffff);
1945 			log.u_bbr.delivered = (uint32_t)((cur->localtime >> 32) & 0x00000000ffffffff);
1946 #ifdef TCP_REQUEST_TRK
1947 			off = (uint64_t)(cur) - (uint64_t)(&rack->rc_tp->t_tcpreq_info[0]);
1948 			log.u_bbr.bbr_substate = (uint8_t)(off / sizeof(struct tcp_sendfile_track));
1949 #endif
1950 			log.u_bbr.inhpts = 1;
1951 			log.u_bbr.flex4 = (uint32_t)(rack->rc_tp->t_sndbytes - cur->sent_at_fs);
1952 			log.u_bbr.flex5 = (uint32_t)(rack->rc_tp->t_snd_rxt_bytes - cur->rxt_at_fs);
1953 			log.u_bbr.flex7 = (uint16_t)cur->hybrid_flags;
1954 		} else {
1955 			log.u_bbr.flex7 = 0xffff;
1956 			log.u_bbr.cur_del_rate = 0xffffffffffffffff;
1957 		}
1958 		/*
1959 		 * Compose bbr_state to be a bit wise 0000ADHF
1960 		 * where A is the always_pace flag
1961 		 * where D is the dgp_on flag
1962 		 * where H is the hybrid_mode on flag
1963 		 * where F is the use_fixed_rate flag.
1964 		 */
1965 		log.u_bbr.bbr_state = rack->rc_always_pace;
1966 		log.u_bbr.bbr_state <<= 1;
1967 		log.u_bbr.bbr_state |= rack->dgp_on;
1968 		log.u_bbr.bbr_state <<= 1;
1969 		log.u_bbr.bbr_state |= rack->rc_hybrid_mode;
1970 		log.u_bbr.bbr_state <<= 1;
1971 		log.u_bbr.bbr_state |= rack->use_fixed_rate;
1972 		log.u_bbr.flex8 = mod;
1973 		tcp_log_event(rack->rc_tp, NULL,
1974 		    &rack->rc_inp->inp_socket->so_rcv,
1975 		    &rack->rc_inp->inp_socket->so_snd,
1976 		    TCP_HYBRID_PACING_LOG, 0,
1977 		    0, &log, false, NULL, __func__, __LINE__, &tv);
1978 
1979 	}
1980 #endif
1981 }
1982 
1983 #ifdef TCP_REQUEST_TRK
1984 static void
1985 rack_log_hybrid_sends(struct tcp_rack *rack, struct tcp_sendfile_track *cur, int line)
1986 {
1987 	if (tcp_bblogging_point_on(rack->rc_tp, TCP_BBPOINT_REQ_LEVEL_LOGGING)) {
1988 		union tcp_log_stackspecific log;
1989 		struct timeval tv;
1990 		uint64_t off;
1991 
1992 		/* Convert our ms to a microsecond */
1993 		memset(&log, 0, sizeof(log));
1994 
1995 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
1996 		log.u_bbr.delRate = cur->sent_at_fs;
1997 
1998 		if ((cur->flags & TCP_TRK_TRACK_FLG_LSND) == 0) {
1999 			/*
2000 			 * We did not get a new Rules Applied to set so
2001 			 * no overlapping send occured, this means the
2002 			 * current byte counts are correct.
2003 			 */
2004 			log.u_bbr.cur_del_rate = rack->rc_tp->t_sndbytes;
2005 			log.u_bbr.rttProp = rack->rc_tp->t_snd_rxt_bytes;
2006 		} else {
2007 			/*
2008 			 * Overlapping send case, we switched to a new
2009 			 * send and did a rules applied.
2010 			 */
2011 			log.u_bbr.cur_del_rate = cur->sent_at_ls;
2012 			log.u_bbr.rttProp = cur->rxt_at_ls;
2013 		}
2014 		log.u_bbr.bw_inuse = cur->rxt_at_fs;
2015 		log.u_bbr.cwnd_gain = line;
2016 		off = (uint64_t)(cur) - (uint64_t)(&rack->rc_tp->t_tcpreq_info[0]);
2017 		log.u_bbr.bbr_substate = (uint8_t)(off / sizeof(struct tcp_sendfile_track));
2018 		/* start = < flex1 | flex2 > */
2019 		log.u_bbr.flex2 = (uint32_t)(cur->start & 0x00000000ffffffff);
2020 		log.u_bbr.flex1 = (uint32_t)((cur->start >> 32) & 0x00000000ffffffff);
2021 		/* end = < flex3 | flex4 > */
2022 		log.u_bbr.flex4 = (uint32_t)(cur->end & 0x00000000ffffffff);
2023 		log.u_bbr.flex3 = (uint32_t)((cur->end >> 32) & 0x00000000ffffffff);
2024 
2025 		/* localtime = <delivered | applimited>*/
2026 		log.u_bbr.applimited = (uint32_t)(cur->localtime & 0x00000000ffffffff);
2027 		log.u_bbr.delivered = (uint32_t)((cur->localtime >> 32) & 0x00000000ffffffff);
2028 		/* client timestamp = <lt_epoch | epoch>*/
2029 		log.u_bbr.epoch = (uint32_t)(cur->timestamp & 0x00000000ffffffff);
2030 		log.u_bbr.lt_epoch = (uint32_t)((cur->timestamp >> 32) & 0x00000000ffffffff);
2031 		/* now set all the flags in */
2032 		log.u_bbr.pkts_out = cur->hybrid_flags;
2033 		log.u_bbr.lost = cur->playout_ms;
2034 		log.u_bbr.flex6 = cur->flags;
2035 		/*
2036 		 * Last send time  = <flex5 | pkt_epoch>  note we do not distinguish cases
2037 		 * where a false retransmit occurred so first_send  <-> lastsend may
2038 		 * include longer time then it actually took if we have a false rxt.
2039 		 */
2040 		log.u_bbr.pkt_epoch = (uint32_t)(rack->r_ctl.last_tmit_time_acked & 0x00000000ffffffff);
2041 		log.u_bbr.flex5 = (uint32_t)((rack->r_ctl.last_tmit_time_acked >> 32) & 0x00000000ffffffff);
2042 		/*
2043 		 * Compose bbr_state to be a bit wise 0000ADHF
2044 		 * where A is the always_pace flag
2045 		 * where D is the dgp_on flag
2046 		 * where H is the hybrid_mode on flag
2047 		 * where F is the use_fixed_rate flag.
2048 		 */
2049 		log.u_bbr.bbr_state = rack->rc_always_pace;
2050 		log.u_bbr.bbr_state <<= 1;
2051 		log.u_bbr.bbr_state |= rack->dgp_on;
2052 		log.u_bbr.bbr_state <<= 1;
2053 		log.u_bbr.bbr_state |= rack->rc_hybrid_mode;
2054 		log.u_bbr.bbr_state <<= 1;
2055 		log.u_bbr.bbr_state |= rack->use_fixed_rate;
2056 
2057 		log.u_bbr.flex8 = HYBRID_LOG_SENT_LOST;
2058 		tcp_log_event(rack->rc_tp, NULL,
2059 		    &rack->rc_inp->inp_socket->so_rcv,
2060 		    &rack->rc_inp->inp_socket->so_snd,
2061 		    TCP_HYBRID_PACING_LOG, 0,
2062 		    0, &log, false, NULL, __func__, __LINE__, &tv);
2063 	}
2064 }
2065 #endif
2066 
2067 static inline uint64_t
2068 rack_compensate_for_linerate(struct tcp_rack *rack, uint64_t bw)
2069 {
2070 	uint64_t ret_bw, ether;
2071 	uint64_t u_segsiz;
2072 
2073 	ether = rack->rc_tp->t_maxseg + sizeof(struct tcphdr);
2074 	if (rack->r_is_v6){
2075 #ifdef INET6
2076 		ether += sizeof(struct ip6_hdr);
2077 #endif
2078 		ether += 14;	/* eheader size 6+6+2 */
2079 	} else {
2080 #ifdef INET
2081 		ether += sizeof(struct ip);
2082 #endif
2083 		ether += 14;	/* eheader size 6+6+2 */
2084 	}
2085 	u_segsiz = (uint64_t)min(ctf_fixed_maxseg(rack->rc_tp), rack->r_ctl.rc_pace_min_segs);
2086 	ret_bw = bw;
2087 	ret_bw *= ether;
2088 	ret_bw /= u_segsiz;
2089 	return (ret_bw);
2090 }
2091 
2092 static void
2093 rack_rate_cap_bw(struct tcp_rack *rack, uint64_t *bw, int *capped)
2094 {
2095 #ifdef TCP_REQUEST_TRK
2096 	struct timeval tv;
2097 	uint64_t timenow, timeleft, lenleft, lengone, calcbw;
2098 #endif
2099 
2100 	if (rack->r_ctl.bw_rate_cap == 0)
2101 		return;
2102 #ifdef TCP_REQUEST_TRK
2103 	if (rack->rc_catch_up && rack->rc_hybrid_mode &&
2104 	    (rack->r_ctl.rc_last_sft != NULL)) {
2105 		/*
2106 		 * We have a dynamic cap. The original target
2107 		 * is in bw_rate_cap, but we need to look at
2108 		 * how long it is until we hit the deadline.
2109 		 */
2110 		struct tcp_sendfile_track *ent;
2111 
2112       		ent = rack->r_ctl.rc_last_sft;
2113 		microuptime(&tv);
2114 		timenow = tcp_tv_to_lusec(&tv);
2115 		if (timenow >= ent->deadline) {
2116 			/* No time left we do DGP only */
2117 			rack_log_hybrid_bw(rack, rack->rc_tp->snd_max,
2118 					   0, 0, 0, HYBRID_LOG_OUTOFTIME, 0, ent, __LINE__);
2119 			rack->r_ctl.bw_rate_cap = 0;
2120 			return;
2121 		}
2122 		/* We have the time */
2123 		timeleft = rack->r_ctl.rc_last_sft->deadline - timenow;
2124 		if (timeleft < HPTS_MSEC_IN_SEC) {
2125 			/* If there is less than a ms left just use DGPs rate */
2126 			rack_log_hybrid_bw(rack, rack->rc_tp->snd_max,
2127 					   0, timeleft, 0, HYBRID_LOG_OUTOFTIME, 0, ent, __LINE__);
2128 			rack->r_ctl.bw_rate_cap = 0;
2129 			return;
2130 		}
2131 		/*
2132 		 * Now lets find the amount of data left to send.
2133 		 *
2134 		 * Now ideally we want to use the end_seq to figure out how much more
2135 		 * but it might not be possible (only if we have the TRACK_FG_COMP on the entry..
2136 		 */
2137 		if (ent->flags & TCP_TRK_TRACK_FLG_COMP) {
2138 			if (SEQ_GT(ent->end_seq, rack->rc_tp->snd_una))
2139 				lenleft = ent->end_seq - rack->rc_tp->snd_una;
2140 			else {
2141 				/* TSNH, we should catch it at the send */
2142 				rack_log_hybrid_bw(rack, rack->rc_tp->snd_max,
2143 						   0, timeleft, 0, HYBRID_LOG_CAPERROR, 0, ent, __LINE__);
2144 				rack->r_ctl.bw_rate_cap = 0;
2145 				return;
2146 			}
2147 		} else {
2148 			/*
2149 			 * The hard way, figure out how much is gone and then
2150 			 * take that away from the total the client asked for
2151 			 * (thats off by tls overhead if this is tls).
2152 			 */
2153 			if (SEQ_GT(rack->rc_tp->snd_una, ent->start_seq))
2154 				lengone = rack->rc_tp->snd_una - ent->start_seq;
2155 			else
2156 				lengone = 0;
2157 			if (lengone < (ent->end - ent->start))
2158 				lenleft = (ent->end - ent->start) - lengone;
2159 			else {
2160 				/* TSNH, we should catch it at the send */
2161 				rack_log_hybrid_bw(rack, rack->rc_tp->snd_max,
2162 						   0, timeleft, lengone, HYBRID_LOG_CAPERROR, 0, ent, __LINE__);
2163 				rack->r_ctl.bw_rate_cap = 0;
2164 				return;
2165 			}
2166 		}
2167 		if (lenleft == 0) {
2168 			/* We have it all sent */
2169 			rack_log_hybrid_bw(rack, rack->rc_tp->snd_max,
2170 					   0, timeleft, lenleft, HYBRID_LOG_ALLSENT, 0, ent, __LINE__);
2171 			if (rack->r_ctl.bw_rate_cap)
2172 				goto normal_ratecap;
2173 			else
2174 				return;
2175 		}
2176 		calcbw = lenleft * HPTS_USEC_IN_SEC;
2177 		calcbw /= timeleft;
2178 		/* Now we must compensate for IP/TCP overhead */
2179 		calcbw = rack_compensate_for_linerate(rack, calcbw);
2180 		/* Update the bit rate cap */
2181 		rack->r_ctl.bw_rate_cap = calcbw;
2182 		if ((rack->r_ctl.rc_last_sft->hybrid_flags & TCP_HYBRID_PACING_S_MSS) &&
2183 		    (rack_hybrid_allow_set_maxseg == 1) &&
2184 		    ((rack->r_ctl.rc_last_sft->hybrid_flags & TCP_HYBRID_PACING_SETMSS) == 0)) {
2185 			/* Lets set in a smaller mss possibly here to match our rate-cap */
2186 			uint32_t orig_max;
2187 
2188 			orig_max = rack->r_ctl.rc_pace_max_segs;
2189 			rack->r_ctl.rc_last_sft->hybrid_flags |= TCP_HYBRID_PACING_SETMSS;
2190 			rack->r_ctl.rc_pace_max_segs = rack_get_pacing_len(rack, calcbw, ctf_fixed_maxseg(rack->rc_tp));
2191 			rack_log_type_pacing_sizes(rack->rc_tp, rack, rack->r_ctl.client_suggested_maxseg, orig_max, __LINE__, 5);
2192 		}
2193 		rack_log_hybrid_bw(rack, rack->rc_tp->snd_max,
2194 				   calcbw, timeleft, lenleft, HYBRID_LOG_CAP_CALC, 0, ent, __LINE__);
2195 		if ((calcbw > 0) && (*bw > calcbw)) {
2196 			rack_log_hybrid_bw(rack, rack->rc_tp->snd_max,
2197 					   *bw, ent->deadline, lenleft, HYBRID_LOG_RATE_CAP, 0, ent, __LINE__);
2198 			*capped = 1;
2199 			*bw = calcbw;
2200 		}
2201 		return;
2202 	}
2203 normal_ratecap:
2204 #endif
2205 	if ((rack->r_ctl.bw_rate_cap > 0) && (*bw > rack->r_ctl.bw_rate_cap)) {
2206 #ifdef TCP_REQUEST_TRK
2207 		if (rack->rc_hybrid_mode &&
2208 		    rack->rc_catch_up &&
2209 		    (rack->r_ctl.rc_last_sft != NULL) &&
2210 		    (rack->r_ctl.rc_last_sft->hybrid_flags & TCP_HYBRID_PACING_S_MSS) &&
2211 		    (rack_hybrid_allow_set_maxseg == 1) &&
2212 		    ((rack->r_ctl.rc_last_sft->hybrid_flags & TCP_HYBRID_PACING_SETMSS) == 0)) {
2213 			/* Lets set in a smaller mss possibly here to match our rate-cap */
2214 			uint32_t orig_max;
2215 
2216 			orig_max = rack->r_ctl.rc_pace_max_segs;
2217 			rack->r_ctl.rc_last_sft->hybrid_flags |= TCP_HYBRID_PACING_SETMSS;
2218 			rack->r_ctl.rc_pace_max_segs = rack_get_pacing_len(rack, rack->r_ctl.bw_rate_cap, ctf_fixed_maxseg(rack->rc_tp));
2219 			rack_log_type_pacing_sizes(rack->rc_tp, rack, rack->r_ctl.client_suggested_maxseg, orig_max, __LINE__, 5);
2220 		}
2221 #endif
2222 		*capped = 1;
2223 		*bw = rack->r_ctl.bw_rate_cap;
2224 		rack_log_hybrid_bw(rack, rack->rc_tp->snd_max,
2225 				   *bw, 0, 0,
2226 				   HYBRID_LOG_RATE_CAP, 1, NULL, __LINE__);
2227 	}
2228 }
2229 
2230 static uint64_t
2231 rack_get_gp_est(struct tcp_rack *rack)
2232 {
2233 	uint64_t bw, lt_bw, ret_bw;
2234 
2235 	if (rack->rc_gp_filled == 0) {
2236 		/*
2237 		 * We have yet no b/w measurement,
2238 		 * if we have a user set initial bw
2239 		 * return it. If we don't have that and
2240 		 * we have an srtt, use the tcp IW (10) to
2241 		 * calculate a fictional b/w over the SRTT
2242 		 * which is more or less a guess. Note
2243 		 * we don't use our IW from rack on purpose
2244 		 * so if we have like IW=30, we are not
2245 		 * calculating a "huge" b/w.
2246 		 */
2247 		uint64_t srtt;
2248 
2249 		if (rack->dis_lt_bw == 1)
2250 			lt_bw = 0;
2251 		else
2252 			lt_bw = rack_get_lt_bw(rack);
2253 		if (lt_bw) {
2254 			/*
2255 			 * No goodput bw but a long-term b/w does exist
2256 			 * lets use that.
2257 			 */
2258 			ret_bw = lt_bw;
2259 			goto compensate;
2260 		}
2261 		if (rack->r_ctl.init_rate)
2262 			return (rack->r_ctl.init_rate);
2263 
2264 		/* Ok lets come up with the IW guess, if we have a srtt */
2265 		if (rack->rc_tp->t_srtt == 0) {
2266 			/*
2267 			 * Go with old pacing method
2268 			 * i.e. burst mitigation only.
2269 			 */
2270 			return (0);
2271 		}
2272 		/* Ok lets get the initial TCP win (not racks) */
2273 		bw = tcp_compute_initwnd(tcp_maxseg(rack->rc_tp));
2274 		srtt = (uint64_t)rack->rc_tp->t_srtt;
2275 		bw *= (uint64_t)USECS_IN_SECOND;
2276 		bw /= srtt;
2277 		ret_bw = bw;
2278 		goto compensate;
2279 
2280 	}
2281 	if (rack->r_ctl.num_measurements >= RACK_REQ_AVG) {
2282 		/* Averaging is done, we can return the value */
2283 		bw = rack->r_ctl.gp_bw;
2284 	} else {
2285 		/* Still doing initial average must calculate */
2286 		bw = rack->r_ctl.gp_bw / max(rack->r_ctl.num_measurements, 1);
2287 	}
2288 	if (rack->dis_lt_bw) {
2289 		/* We are not using lt-bw */
2290 		ret_bw = bw;
2291 		goto compensate;
2292 	}
2293 	lt_bw = rack_get_lt_bw(rack);
2294 	if (lt_bw == 0) {
2295 		/* If we don't have one then equate it to the gp_bw */
2296 		lt_bw = rack->r_ctl.gp_bw;
2297 	}
2298 	if (rack->use_lesser_lt_bw) {
2299 		if (lt_bw < bw)
2300 			ret_bw = lt_bw;
2301 		else
2302 			ret_bw = bw;
2303 	} else {
2304 		if (lt_bw > bw)
2305 			ret_bw = lt_bw;
2306 		else
2307 			ret_bw = bw;
2308 	}
2309 	/*
2310 	 * Now lets compensate based on the TCP/IP overhead. Our
2311 	 * Goodput estimate does not include this so we must pace out
2312 	 * a bit faster since our pacing calculations do. The pacing
2313 	 * calculations use the base ETHERNET_SEGMENT_SIZE and the segsiz
2314 	 * we are using to do this, so we do that here in the opposite
2315 	 * direction as well. This means that if we are tunneled and the
2316 	 * segsiz is say 1200 bytes we will get quite a boost, but its
2317 	 * compensated for in the pacing time the opposite way.
2318 	 */
2319 compensate:
2320 	ret_bw = rack_compensate_for_linerate(rack, ret_bw);
2321 	return(ret_bw);
2322 }
2323 
2324 
2325 static uint64_t
2326 rack_get_bw(struct tcp_rack *rack)
2327 {
2328 	uint64_t bw;
2329 
2330 	if (rack->use_fixed_rate) {
2331 		/* Return the fixed pacing rate */
2332 		return (rack_get_fixed_pacing_bw(rack));
2333 	}
2334 	bw = rack_get_gp_est(rack);
2335 	return (bw);
2336 }
2337 
2338 static uint16_t
2339 rack_get_output_gain(struct tcp_rack *rack, struct rack_sendmap *rsm)
2340 {
2341 	if (rack->use_fixed_rate) {
2342 		return (100);
2343 	} else if (rack->in_probe_rtt && (rsm == NULL))
2344 		return (rack->r_ctl.rack_per_of_gp_probertt);
2345 	else if ((IN_FASTRECOVERY(rack->rc_tp->t_flags) &&
2346 		  rack->r_ctl.rack_per_of_gp_rec)) {
2347 		if (rsm) {
2348 			/* a retransmission always use the recovery rate */
2349 			return (rack->r_ctl.rack_per_of_gp_rec);
2350 		} else if (rack->rack_rec_nonrxt_use_cr) {
2351 			/* Directed to use the configured rate */
2352 			goto configured_rate;
2353 		} else if (rack->rack_no_prr &&
2354 			   (rack->r_ctl.rack_per_of_gp_rec > 100)) {
2355 			/* No PRR, lets just use the b/w estimate only */
2356 			return (100);
2357 		} else {
2358 			/*
2359 			 * Here we may have a non-retransmit but we
2360 			 * have no overrides, so just use the recovery
2361 			 * rate (prr is in effect).
2362 			 */
2363 			return (rack->r_ctl.rack_per_of_gp_rec);
2364 		}
2365 	}
2366 configured_rate:
2367 	/* For the configured rate we look at our cwnd vs the ssthresh */
2368 	if (rack->r_ctl.cwnd_to_use < rack->rc_tp->snd_ssthresh)
2369 		return (rack->r_ctl.rack_per_of_gp_ss);
2370 	else
2371 		return (rack->r_ctl.rack_per_of_gp_ca);
2372 }
2373 
2374 static void
2375 rack_log_dsack_event(struct tcp_rack *rack, uint8_t mod, uint32_t flex4, uint32_t flex5, uint32_t flex6)
2376 {
2377 	/*
2378 	 * Types of logs (mod value)
2379 	 * 1 = dsack_persists reduced by 1 via T-O or fast recovery exit.
2380 	 * 2 = a dsack round begins, persist is reset to 16.
2381 	 * 3 = a dsack round ends
2382 	 * 4 = Dsack option increases rack rtt flex5 is the srtt input, flex6 is thresh
2383 	 * 5 = Socket option set changing the control flags rc_rack_tmr_std_based, rc_rack_use_dsack
2384 	 * 6 = Final rack rtt, flex4 is srtt and flex6 is final limited thresh.
2385 	 */
2386 	if (tcp_bblogging_on(rack->rc_tp)) {
2387 		union tcp_log_stackspecific log;
2388 		struct timeval tv;
2389 
2390 		memset(&log, 0, sizeof(log));
2391 		log.u_bbr.flex1 = rack->rc_rack_tmr_std_based;
2392 		log.u_bbr.flex1 <<= 1;
2393 		log.u_bbr.flex1 |= rack->rc_rack_use_dsack;
2394 		log.u_bbr.flex1 <<= 1;
2395 		log.u_bbr.flex1 |= rack->rc_dsack_round_seen;
2396 		log.u_bbr.flex2 = rack->r_ctl.dsack_round_end;
2397 		log.u_bbr.flex3 = rack->r_ctl.num_dsack;
2398 		log.u_bbr.flex4 = flex4;
2399 		log.u_bbr.flex5 = flex5;
2400 		log.u_bbr.flex6 = flex6;
2401 		log.u_bbr.flex7 = rack->r_ctl.dsack_persist;
2402 		log.u_bbr.flex8 = mod;
2403 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
2404 		log.u_bbr.epoch = rack->r_ctl.current_round;
2405 		log.u_bbr.lt_epoch = rack->r_ctl.rc_considered_lost;
2406 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
2407 		    &rack->rc_inp->inp_socket->so_rcv,
2408 		    &rack->rc_inp->inp_socket->so_snd,
2409 		    RACK_DSACK_HANDLING, 0,
2410 		    0, &log, false, &tv);
2411 	}
2412 }
2413 
2414 static void
2415 rack_log_hdwr_pacing(struct tcp_rack *rack,
2416 		     uint64_t rate, uint64_t hw_rate, int line,
2417 		     int error, uint16_t mod)
2418 {
2419 	if (tcp_bblogging_on(rack->rc_tp)) {
2420 		union tcp_log_stackspecific log;
2421 		struct timeval tv;
2422 		const struct ifnet *ifp;
2423 		uint64_t ifp64;
2424 
2425 		memset(&log, 0, sizeof(log));
2426 		log.u_bbr.flex1 = ((hw_rate >> 32) & 0x00000000ffffffff);
2427 		log.u_bbr.flex2 = (hw_rate & 0x00000000ffffffff);
2428 		if (rack->r_ctl.crte) {
2429 			ifp = rack->r_ctl.crte->ptbl->rs_ifp;
2430 		} else if (rack->rc_inp->inp_route.ro_nh &&
2431 			   rack->rc_inp->inp_route.ro_nh->nh_ifp) {
2432 			ifp = rack->rc_inp->inp_route.ro_nh->nh_ifp;
2433 		} else
2434 			ifp = NULL;
2435 		if (ifp) {
2436 			ifp64 = (uintptr_t)ifp;
2437 			log.u_bbr.flex3 = ((ifp64  >> 32) & 0x00000000ffffffff);
2438 			log.u_bbr.flex4 = (ifp64 & 0x00000000ffffffff);
2439 		}
2440 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
2441 		log.u_bbr.bw_inuse = rate;
2442 		log.u_bbr.flex5 = line;
2443 		log.u_bbr.flex6 = error;
2444 		log.u_bbr.flex7 = mod;
2445 		log.u_bbr.applimited = rack->r_ctl.rc_pace_max_segs;
2446 		log.u_bbr.flex8 = rack->use_fixed_rate;
2447 		log.u_bbr.flex8 <<= 1;
2448 		log.u_bbr.flex8 |= rack->rack_hdrw_pacing;
2449 		log.u_bbr.pkts_out = rack->rc_tp->t_maxseg;
2450 		log.u_bbr.delRate = rack->r_ctl.crte_prev_rate;
2451 		if (rack->r_ctl.crte)
2452 			log.u_bbr.cur_del_rate = rack->r_ctl.crte->rate;
2453 		else
2454 			log.u_bbr.cur_del_rate = 0;
2455 		log.u_bbr.rttProp = rack->r_ctl.last_hw_bw_req;
2456 		log.u_bbr.epoch = rack->r_ctl.current_round;
2457 		log.u_bbr.lt_epoch = rack->r_ctl.rc_considered_lost;
2458 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
2459 		    &rack->rc_inp->inp_socket->so_rcv,
2460 		    &rack->rc_inp->inp_socket->so_snd,
2461 		    BBR_LOG_HDWR_PACE, 0,
2462 		    0, &log, false, &tv);
2463 	}
2464 }
2465 
2466 static uint64_t
2467 rack_get_output_bw(struct tcp_rack *rack, uint64_t bw, struct rack_sendmap *rsm, int *capped)
2468 {
2469 	/*
2470 	 * We allow rack_per_of_gp_xx to dictate our bw rate we want.
2471 	 */
2472 	uint64_t bw_est, high_rate;
2473 	uint64_t gain;
2474 
2475 	gain = (uint64_t)rack_get_output_gain(rack, rsm);
2476 	bw_est = bw * gain;
2477 	bw_est /= (uint64_t)100;
2478 	/* Never fall below the minimum (def 64kbps) */
2479 	if (bw_est < RACK_MIN_BW)
2480 		bw_est = RACK_MIN_BW;
2481 	if (rack->r_rack_hw_rate_caps) {
2482 		/* Rate caps are in place */
2483 		if (rack->r_ctl.crte != NULL) {
2484 			/* We have a hdwr rate already */
2485 			high_rate = tcp_hw_highest_rate(rack->r_ctl.crte);
2486 			if (bw_est >= high_rate) {
2487 				/* We are capping bw at the highest rate table entry */
2488 				if (rack_hw_rate_cap_per &&
2489 				    (((high_rate * (100 + rack_hw_rate_cap_per)) / 100) < bw_est)) {
2490 					rack->r_rack_hw_rate_caps = 0;
2491 					goto done;
2492 				}
2493 				rack_log_hdwr_pacing(rack,
2494 						     bw_est, high_rate, __LINE__,
2495 						     0, 3);
2496 				bw_est = high_rate;
2497 				if (capped)
2498 					*capped = 1;
2499 			}
2500 		} else if ((rack->rack_hdrw_pacing == 0) &&
2501 			   (rack->rack_hdw_pace_ena) &&
2502 			   (rack->rack_attempt_hdwr_pace == 0) &&
2503 			   (rack->rc_inp->inp_route.ro_nh != NULL) &&
2504 			   (rack->rc_inp->inp_route.ro_nh->nh_ifp != NULL)) {
2505 			/*
2506 			 * Special case, we have not yet attempted hardware
2507 			 * pacing, and yet we may, when we do, find out if we are
2508 			 * above the highest rate. We need to know the maxbw for the interface
2509 			 * in question (if it supports ratelimiting). We get back
2510 			 * a 0, if the interface is not found in the RL lists.
2511 			 */
2512 			high_rate = tcp_hw_highest_rate_ifp(rack->rc_inp->inp_route.ro_nh->nh_ifp, rack->rc_inp);
2513 			if (high_rate) {
2514 				/* Yep, we have a rate is it above this rate? */
2515 				if (bw_est > high_rate) {
2516 					bw_est = high_rate;
2517 					if (capped)
2518 						*capped = 1;
2519 				}
2520 			}
2521 		}
2522 	}
2523 done:
2524 	return (bw_est);
2525 }
2526 
2527 static void
2528 rack_log_retran_reason(struct tcp_rack *rack, struct rack_sendmap *rsm, uint32_t tsused, uint32_t thresh, int mod)
2529 {
2530 	if (tcp_bblogging_on(rack->rc_tp)) {
2531 		union tcp_log_stackspecific log;
2532 		struct timeval tv;
2533 
2534 		if ((mod != 1) && (rack_verbose_logging == 0))  {
2535 			/*
2536 			 * We get 3 values currently for mod
2537 			 * 1 - We are retransmitting and this tells the reason.
2538 			 * 2 - We are clearing a dup-ack count.
2539 			 * 3 - We are incrementing a dup-ack count.
2540 			 *
2541 			 * The clear/increment are only logged
2542 			 * if you have BBverbose on.
2543 			 */
2544 			return;
2545 		}
2546 		memset(&log, 0, sizeof(log));
2547 		log.u_bbr.flex1 = tsused;
2548 		log.u_bbr.flex2 = thresh;
2549 		log.u_bbr.flex3 = rsm->r_flags;
2550 		log.u_bbr.flex4 = rsm->r_dupack;
2551 		log.u_bbr.flex5 = rsm->r_start;
2552 		log.u_bbr.flex6 = rsm->r_end;
2553 		log.u_bbr.flex8 = mod;
2554 		log.u_bbr.inhpts = tcp_in_hpts(rack->rc_tp);
2555 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
2556 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
2557 		log.u_bbr.pkts_out = rack->r_ctl.rc_out_at_rto;
2558 		log.u_bbr.delivered = rack->r_ctl.rc_snd_max_at_rto;
2559 		log.u_bbr.pacing_gain = rack->r_must_retran;
2560 		log.u_bbr.epoch = rack->r_ctl.current_round;
2561 		log.u_bbr.lt_epoch = rack->r_ctl.rc_considered_lost;
2562 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
2563 		    &rack->rc_inp->inp_socket->so_rcv,
2564 		    &rack->rc_inp->inp_socket->so_snd,
2565 		    BBR_LOG_SETTINGS_CHG, 0,
2566 		    0, &log, false, &tv);
2567 	}
2568 }
2569 
2570 static void
2571 rack_log_to_start(struct tcp_rack *rack, uint32_t cts, uint32_t to, int32_t pacing_delay, uint8_t which)
2572 {
2573 	if (tcp_bblogging_on(rack->rc_tp)) {
2574 		union tcp_log_stackspecific log;
2575 		struct timeval tv;
2576 
2577 		memset(&log, 0, sizeof(log));
2578 		log.u_bbr.flex1 = rack->rc_tp->t_srtt;
2579 		log.u_bbr.flex2 = to;
2580 		log.u_bbr.flex3 = rack->r_ctl.rc_hpts_flags;
2581 		log.u_bbr.flex4 = pacing_delay;
2582 		log.u_bbr.flex5 = rack->rc_tp->t_hpts_slot;
2583 		log.u_bbr.flex6 = rack->rc_tp->t_rxtcur;
2584 		log.u_bbr.flex7 = rack->rc_in_persist;
2585 		log.u_bbr.flex8 = which;
2586 		if (rack->rack_no_prr)
2587 			log.u_bbr.pkts_out = 0;
2588 		else
2589 			log.u_bbr.pkts_out = rack->r_ctl.rc_prr_sndcnt;
2590 		log.u_bbr.inhpts = tcp_in_hpts(rack->rc_tp);
2591 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
2592 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
2593 		log.u_bbr.pkts_out = rack->r_ctl.rc_out_at_rto;
2594 		log.u_bbr.delivered = rack->r_ctl.rc_snd_max_at_rto;
2595 		log.u_bbr.pacing_gain = rack->r_must_retran;
2596 		log.u_bbr.cwnd_gain = rack->rack_deferred_inited;
2597 		log.u_bbr.pkt_epoch = rack->rc_has_collapsed;
2598 		log.u_bbr.lt_epoch = rack->rc_tp->t_rxtshift;
2599 		log.u_bbr.lost = rack_rto_min;
2600 		log.u_bbr.epoch = rack->r_ctl.roundends;
2601 		log.u_bbr.bw_inuse = rack->r_ctl.current_round;
2602 		log.u_bbr.bw_inuse <<= 32;
2603 		log.u_bbr.bw_inuse |= rack->r_ctl.rc_considered_lost;
2604 		log.u_bbr.applimited = rack->rc_tp->t_flags2;
2605 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
2606 		    &rack->rc_inp->inp_socket->so_rcv,
2607 		    &rack->rc_inp->inp_socket->so_snd,
2608 		    BBR_LOG_TIMERSTAR, 0,
2609 		    0, &log, false, &tv);
2610 	}
2611 }
2612 
2613 static void
2614 rack_log_to_event(struct tcp_rack *rack, int32_t to_num, struct rack_sendmap *rsm)
2615 {
2616 	if (tcp_bblogging_on(rack->rc_tp)) {
2617 		union tcp_log_stackspecific log;
2618 		struct timeval tv;
2619 
2620 		memset(&log, 0, sizeof(log));
2621 		log.u_bbr.inhpts = tcp_in_hpts(rack->rc_tp);
2622 		log.u_bbr.flex8 = to_num;
2623 		log.u_bbr.flex1 = rack->r_ctl.rc_rack_min_rtt;
2624 		log.u_bbr.flex2 = rack->rc_rack_rtt;
2625 		if (rsm == NULL)
2626 			log.u_bbr.flex3 = 0;
2627 		else
2628 			log.u_bbr.flex3 = rsm->r_end - rsm->r_start;
2629 		if (rack->rack_no_prr)
2630 			log.u_bbr.flex5 = 0;
2631 		else
2632 			log.u_bbr.flex5 = rack->r_ctl.rc_prr_sndcnt;
2633 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
2634 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
2635 		log.u_bbr.pkts_out = rack->r_ctl.rc_out_at_rto;
2636 		log.u_bbr.delivered = rack->r_ctl.rc_snd_max_at_rto;
2637 		log.u_bbr.pacing_gain = rack->r_must_retran;
2638 		log.u_bbr.bw_inuse = rack->r_ctl.current_round;
2639 		log.u_bbr.bw_inuse <<= 32;
2640 		log.u_bbr.bw_inuse |= rack->r_ctl.rc_considered_lost;
2641 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
2642 		    &rack->rc_inp->inp_socket->so_rcv,
2643 		    &rack->rc_inp->inp_socket->so_snd,
2644 		    BBR_LOG_RTO, 0,
2645 		    0, &log, false, &tv);
2646 	}
2647 }
2648 
2649 static void
2650 rack_log_map_chg(struct tcpcb *tp, struct tcp_rack *rack,
2651 		 struct rack_sendmap *prev,
2652 		 struct rack_sendmap *rsm,
2653 		 struct rack_sendmap *next,
2654 		 int flag, uint32_t th_ack, int line)
2655 {
2656 	if (rack_verbose_logging && tcp_bblogging_on(rack->rc_tp)) {
2657 		union tcp_log_stackspecific log;
2658 		struct timeval tv;
2659 
2660 		memset(&log, 0, sizeof(log));
2661 		log.u_bbr.flex8 = flag;
2662 		log.u_bbr.inhpts = tcp_in_hpts(rack->rc_tp);
2663 		log.u_bbr.cur_del_rate = (uintptr_t)prev;
2664 		log.u_bbr.delRate = (uintptr_t)rsm;
2665 		log.u_bbr.rttProp = (uintptr_t)next;
2666 		log.u_bbr.flex7 = 0;
2667 		if (prev) {
2668 			log.u_bbr.flex1 = prev->r_start;
2669 			log.u_bbr.flex2 = prev->r_end;
2670 			log.u_bbr.flex7 |= 0x4;
2671 		}
2672 		if (rsm) {
2673 			log.u_bbr.flex3 = rsm->r_start;
2674 			log.u_bbr.flex4 = rsm->r_end;
2675 			log.u_bbr.flex7 |= 0x2;
2676 		}
2677 		if (next) {
2678 			log.u_bbr.flex5 = next->r_start;
2679 			log.u_bbr.flex6 = next->r_end;
2680 			log.u_bbr.flex7 |= 0x1;
2681 		}
2682 		log.u_bbr.applimited = line;
2683 		log.u_bbr.pkts_out = th_ack;
2684 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
2685 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
2686 		if (rack->rack_no_prr)
2687 			log.u_bbr.lost = 0;
2688 		else
2689 			log.u_bbr.lost = rack->r_ctl.rc_prr_sndcnt;
2690 		log.u_bbr.bw_inuse = rack->r_ctl.current_round;
2691 		log.u_bbr.bw_inuse <<= 32;
2692 		log.u_bbr.bw_inuse |= rack->r_ctl.rc_considered_lost;
2693 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
2694 		    &rack->rc_inp->inp_socket->so_rcv,
2695 		    &rack->rc_inp->inp_socket->so_snd,
2696 		    TCP_LOG_MAPCHG, 0,
2697 		    0, &log, false, &tv);
2698 	}
2699 }
2700 
2701 static void
2702 rack_log_rtt_upd(struct tcpcb *tp, struct tcp_rack *rack, uint32_t t, uint32_t len,
2703 		 struct rack_sendmap *rsm, int conf)
2704 {
2705 	if (tcp_bblogging_on(tp)) {
2706 		union tcp_log_stackspecific log;
2707 		struct timeval tv;
2708 		memset(&log, 0, sizeof(log));
2709 		log.u_bbr.inhpts = tcp_in_hpts(rack->rc_tp);
2710 		log.u_bbr.flex1 = t;
2711 		log.u_bbr.flex2 = len;
2712 		log.u_bbr.flex3 = rack->r_ctl.rc_rack_min_rtt;
2713 		log.u_bbr.flex4 = rack->r_ctl.rack_rs.rs_rtt_lowest;
2714 		log.u_bbr.flex5 = rack->r_ctl.rack_rs.rs_rtt_highest;
2715 		log.u_bbr.flex6 = rack->r_ctl.rack_rs.rs_us_rtrcnt;
2716 		log.u_bbr.flex7 = conf;
2717 		log.u_bbr.rttProp = (uint64_t)rack->r_ctl.rack_rs.rs_rtt_tot;
2718 		log.u_bbr.flex8 = rack->r_ctl.rc_rate_sample_method;
2719 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
2720 		log.u_bbr.delivered = rack->r_ctl.rack_rs.rs_us_rtrcnt;
2721 		log.u_bbr.pkts_out = rack->r_ctl.rack_rs.rs_flags;
2722 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
2723 		if (rsm) {
2724 			log.u_bbr.pkt_epoch = rsm->r_start;
2725 			log.u_bbr.lost = rsm->r_end;
2726 			log.u_bbr.cwnd_gain = rsm->r_rtr_cnt;
2727 			/* We loose any upper of the 24 bits */
2728 			log.u_bbr.pacing_gain = (uint16_t)rsm->r_flags;
2729 		} else {
2730 			/* Its a SYN */
2731 			log.u_bbr.pkt_epoch = rack->rc_tp->iss;
2732 			log.u_bbr.lost = 0;
2733 			log.u_bbr.cwnd_gain = 0;
2734 			log.u_bbr.pacing_gain = 0;
2735 		}
2736 		/* Write out general bits of interest rrs here */
2737 		log.u_bbr.use_lt_bw = rack->rc_highly_buffered;
2738 		log.u_bbr.use_lt_bw <<= 1;
2739 		log.u_bbr.use_lt_bw |= rack->forced_ack;
2740 		log.u_bbr.use_lt_bw <<= 1;
2741 		log.u_bbr.use_lt_bw |= rack->rc_gp_dyn_mul;
2742 		log.u_bbr.use_lt_bw <<= 1;
2743 		log.u_bbr.use_lt_bw |= rack->in_probe_rtt;
2744 		log.u_bbr.use_lt_bw <<= 1;
2745 		log.u_bbr.use_lt_bw |= rack->measure_saw_probe_rtt;
2746 		log.u_bbr.use_lt_bw <<= 1;
2747 		log.u_bbr.use_lt_bw |= rack->app_limited_needs_set;
2748 		log.u_bbr.use_lt_bw <<= 1;
2749 		log.u_bbr.use_lt_bw |= rack->rc_gp_filled;
2750 		log.u_bbr.use_lt_bw <<= 1;
2751 		log.u_bbr.use_lt_bw |= rack->rc_dragged_bottom;
2752 		log.u_bbr.applimited = rack->r_ctl.rc_target_probertt_flight;
2753 		log.u_bbr.epoch = rack->r_ctl.rc_time_probertt_starts;
2754 		log.u_bbr.lt_epoch = rack->r_ctl.rc_time_probertt_entered;
2755 		log.u_bbr.cur_del_rate = rack->r_ctl.rc_lower_rtt_us_cts;
2756 		log.u_bbr.delRate = rack->r_ctl.rc_gp_srtt;
2757 		log.u_bbr.bw_inuse = tcp_tv_to_usec(&rack->r_ctl.act_rcv_time);
2758 		log.u_bbr.bw_inuse <<= 32;
2759 		if (rsm)
2760 			log.u_bbr.bw_inuse |= ((uint32_t)rsm->r_tim_lastsent[(rsm->r_rtr_cnt-1)]);
2761 		TCP_LOG_EVENTP(tp, NULL,
2762 		    &rack->rc_inp->inp_socket->so_rcv,
2763 		    &rack->rc_inp->inp_socket->so_snd,
2764 		    BBR_LOG_BBRRTT, 0,
2765 		    0, &log, false, &tv);
2766 
2767 
2768 	}
2769 }
2770 
2771 static void
2772 rack_log_rtt_sample(struct tcp_rack *rack, uint32_t rtt)
2773 {
2774 	/*
2775 	 * Log the rtt sample we are
2776 	 * applying to the srtt algorithm in
2777 	 * useconds.
2778 	 */
2779 	if (tcp_bblogging_on(rack->rc_tp)) {
2780 		union tcp_log_stackspecific log;
2781 		struct timeval tv;
2782 
2783 		/* Convert our ms to a microsecond */
2784 		memset(&log, 0, sizeof(log));
2785 		log.u_bbr.flex1 = rtt;
2786 		log.u_bbr.flex6 = rack->rc_tp->t_rxtcur;
2787 		log.u_bbr.flex7 = 1;
2788 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
2789 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
2790 		log.u_bbr.pkts_out = rack->r_ctl.rc_out_at_rto;
2791 		log.u_bbr.delivered = rack->r_ctl.rc_snd_max_at_rto;
2792 		log.u_bbr.pacing_gain = rack->r_must_retran;
2793 		/*
2794 		 * We capture in delRate the upper 32 bits as
2795 		 * the confidence level we had declared, and the
2796 		 * lower 32 bits as the actual RTT using the arrival
2797 		 * timestamp.
2798 		 */
2799 		log.u_bbr.delRate = rack->r_ctl.rack_rs.confidence;
2800 		log.u_bbr.delRate <<= 32;
2801 		log.u_bbr.delRate |= rack->r_ctl.rack_rs.rs_us_rtt;
2802 		/* Lets capture all the things that make up t_rtxcur */
2803 		log.u_bbr.applimited = rack_rto_min;
2804 		log.u_bbr.epoch = rack_rto_max;
2805 		log.u_bbr.lt_epoch = rack->r_ctl.timer_slop;
2806 		log.u_bbr.lost = rack_rto_min;
2807 		log.u_bbr.pkt_epoch = TICKS_2_USEC(tcp_rexmit_slop);
2808 		log.u_bbr.rttProp = RACK_REXMTVAL(rack->rc_tp);
2809 		log.u_bbr.bw_inuse = rack->r_ctl.act_rcv_time.tv_sec;
2810 		log.u_bbr.bw_inuse *= HPTS_USEC_IN_SEC;
2811 		log.u_bbr.bw_inuse += rack->r_ctl.act_rcv_time.tv_usec;
2812 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
2813 		    &rack->rc_inp->inp_socket->so_rcv,
2814 		    &rack->rc_inp->inp_socket->so_snd,
2815 		    TCP_LOG_RTT, 0,
2816 		    0, &log, false, &tv);
2817 	}
2818 }
2819 
2820 static void
2821 rack_log_rtt_sample_calc(struct tcp_rack *rack, uint32_t rtt, uint32_t send_time, uint32_t ack_time, int where)
2822 {
2823 	if (rack_verbose_logging && tcp_bblogging_on(rack->rc_tp)) {
2824 		union tcp_log_stackspecific log;
2825 		struct timeval tv;
2826 
2827 		/* Convert our ms to a microsecond */
2828 		memset(&log, 0, sizeof(log));
2829 		log.u_bbr.flex1 = rtt;
2830 		log.u_bbr.flex2 = send_time;
2831 		log.u_bbr.flex3 = ack_time;
2832 		log.u_bbr.flex4 = where;
2833 		log.u_bbr.flex7 = 2;
2834 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
2835 		log.u_bbr.bw_inuse = rack->r_ctl.current_round;
2836 		log.u_bbr.bw_inuse <<= 32;
2837 		log.u_bbr.bw_inuse |= rack->r_ctl.rc_considered_lost;
2838 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
2839 		    &rack->rc_inp->inp_socket->so_rcv,
2840 		    &rack->rc_inp->inp_socket->so_snd,
2841 		    TCP_LOG_RTT, 0,
2842 		    0, &log, false, &tv);
2843 	}
2844 }
2845 
2846 
2847 static void
2848 rack_log_rtt_sendmap(struct tcp_rack *rack, uint32_t idx, uint64_t tsv, uint32_t tsecho)
2849 {
2850 	if (rack_verbose_logging && tcp_bblogging_on(rack->rc_tp)) {
2851 		union tcp_log_stackspecific log;
2852 		struct timeval tv;
2853 
2854 		/* Convert our ms to a microsecond */
2855 		memset(&log, 0, sizeof(log));
2856 		log.u_bbr.flex1 = idx;
2857 		log.u_bbr.flex2 = rack_ts_to_msec(tsv);
2858 		log.u_bbr.flex3 = tsecho;
2859 		log.u_bbr.flex7 = 3;
2860 		log.u_bbr.rttProp = tsv;
2861 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
2862 		log.u_bbr.bw_inuse = rack->r_ctl.current_round;
2863 		log.u_bbr.bw_inuse <<= 32;
2864 		log.u_bbr.bw_inuse |= rack->r_ctl.rc_considered_lost;
2865 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
2866 		    &rack->rc_inp->inp_socket->so_rcv,
2867 		    &rack->rc_inp->inp_socket->so_snd,
2868 		    TCP_LOG_RTT, 0,
2869 		    0, &log, false, &tv);
2870 	}
2871 }
2872 
2873 
2874 static inline void
2875 rack_log_progress_event(struct tcp_rack *rack, struct tcpcb *tp, uint32_t tick,  int event, int line)
2876 {
2877 	if (rack_verbose_logging && tcp_bblogging_on(rack->rc_tp)) {
2878 		union tcp_log_stackspecific log;
2879 		struct timeval tv;
2880 
2881 		memset(&log, 0, sizeof(log));
2882 		log.u_bbr.inhpts = tcp_in_hpts(rack->rc_tp);
2883 		log.u_bbr.flex1 = line;
2884 		log.u_bbr.flex2 = tick;
2885 		log.u_bbr.flex3 = tp->t_maxunacktime;
2886 		log.u_bbr.flex4 = tp->t_acktime;
2887 		log.u_bbr.flex8 = event;
2888 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
2889 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
2890 		log.u_bbr.pkts_out = rack->r_ctl.rc_out_at_rto;
2891 		log.u_bbr.delivered = rack->r_ctl.rc_snd_max_at_rto;
2892 		log.u_bbr.pacing_gain = rack->r_must_retran;
2893 		log.u_bbr.bw_inuse = rack->r_ctl.current_round;
2894 		log.u_bbr.bw_inuse <<= 32;
2895 		log.u_bbr.bw_inuse |= rack->r_ctl.rc_considered_lost;
2896 		TCP_LOG_EVENTP(tp, NULL,
2897 		    &rack->rc_inp->inp_socket->so_rcv,
2898 		    &rack->rc_inp->inp_socket->so_snd,
2899 		    BBR_LOG_PROGRESS, 0,
2900 		    0, &log, false, &tv);
2901 	}
2902 }
2903 
2904 static void
2905 rack_log_type_bbrsnd(struct tcp_rack *rack, uint32_t len, uint32_t pacing_delay, uint32_t cts, struct timeval *tv, int line)
2906 {
2907 	if (rack_verbose_logging && tcp_bblogging_on(rack->rc_tp)) {
2908 		union tcp_log_stackspecific log;
2909 
2910 		memset(&log, 0, sizeof(log));
2911 		log.u_bbr.inhpts = tcp_in_hpts(rack->rc_tp);
2912 		log.u_bbr.flex1 = pacing_delay;
2913 		if (rack->rack_no_prr)
2914 			log.u_bbr.flex2 = 0;
2915 		else
2916 			log.u_bbr.flex2 = rack->r_ctl.rc_prr_sndcnt;
2917 		log.u_bbr.flex4 = rack->r_ctl.rc_hpts_flags;
2918 		log.u_bbr.flex6 = line;
2919 		log.u_bbr.flex7 = (0x0000ffff & rack->r_ctl.rc_hpts_flags);
2920 		log.u_bbr.flex8 = rack->rc_in_persist;
2921 		log.u_bbr.timeStamp = cts;
2922 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
2923 		log.u_bbr.pkts_out = rack->r_ctl.rc_out_at_rto;
2924 		log.u_bbr.delivered = rack->r_ctl.rc_snd_max_at_rto;
2925 		log.u_bbr.pacing_gain = rack->r_must_retran;
2926 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
2927 		    &rack->rc_inp->inp_socket->so_rcv,
2928 		    &rack->rc_inp->inp_socket->so_snd,
2929 		    BBR_LOG_BBRSND, 0,
2930 		    0, &log, false, tv);
2931 	}
2932 }
2933 
2934 static void
2935 rack_log_doseg_done(struct tcp_rack *rack, uint32_t cts, int32_t nxt_pkt, int32_t did_out, int way_out, int nsegs)
2936 {
2937 	if (tcp_bblogging_on(rack->rc_tp)) {
2938 		union tcp_log_stackspecific log;
2939 		struct timeval tv;
2940 
2941 		memset(&log, 0, sizeof(log));
2942 		log.u_bbr.flex1 = did_out;
2943 		log.u_bbr.flex2 = nxt_pkt;
2944 		log.u_bbr.flex3 = way_out;
2945 		log.u_bbr.flex4 = rack->r_ctl.rc_hpts_flags;
2946 		if (rack->rack_no_prr)
2947 			log.u_bbr.flex5 = 0;
2948 		else
2949 			log.u_bbr.flex5 = rack->r_ctl.rc_prr_sndcnt;
2950 		log.u_bbr.flex6 = nsegs;
2951 		log.u_bbr.applimited = rack->r_ctl.rc_pace_min_segs;
2952 		log.u_bbr.flex7 = rack->rc_ack_can_sendout_data;	/* Do we have ack-can-send set */
2953 		log.u_bbr.flex7 <<= 1;
2954 		log.u_bbr.flex7 |= rack->r_fast_output;	/* is fast output primed */
2955 		log.u_bbr.flex7 <<= 1;
2956 		log.u_bbr.flex7 |= rack->r_wanted_output;	/* Do we want output */
2957 		log.u_bbr.flex8 = rack->rc_in_persist;
2958 		log.u_bbr.inhpts = tcp_in_hpts(rack->rc_tp);
2959 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
2960 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
2961 		log.u_bbr.use_lt_bw = rack->r_ent_rec_ns;
2962 		log.u_bbr.use_lt_bw <<= 1;
2963 		log.u_bbr.use_lt_bw |= rack->r_might_revert;
2964 		log.u_bbr.pkts_out = rack->r_ctl.rc_out_at_rto;
2965 		log.u_bbr.delivered = rack->r_ctl.rc_snd_max_at_rto;
2966 		log.u_bbr.pacing_gain = rack->r_must_retran;
2967 		log.u_bbr.bw_inuse = rack->r_ctl.current_round;
2968 		log.u_bbr.bw_inuse <<= 32;
2969 		log.u_bbr.bw_inuse |= rack->r_ctl.rc_considered_lost;
2970 		log.u_bbr.epoch = rack->rc_inp->inp_socket->so_snd.sb_hiwat;
2971 		log.u_bbr.lt_epoch = rack->rc_inp->inp_socket->so_rcv.sb_hiwat;
2972 		log.u_bbr.lost = rack->rc_tp->t_srtt;
2973 		log.u_bbr.pkt_epoch = rack->rc_tp->rfbuf_cnt;
2974 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
2975 		    &rack->rc_inp->inp_socket->so_rcv,
2976 		    &rack->rc_inp->inp_socket->so_snd,
2977 		    BBR_LOG_DOSEG_DONE, 0,
2978 		    0, &log, false, &tv);
2979 	}
2980 }
2981 
2982 static void
2983 rack_log_type_pacing_sizes(struct tcpcb *tp, struct tcp_rack *rack, uint32_t arg1, uint32_t arg2, uint32_t arg3, uint8_t frm)
2984 {
2985 	if (tcp_bblogging_on(rack->rc_tp)) {
2986 		union tcp_log_stackspecific log;
2987 		struct timeval tv;
2988 
2989 		memset(&log, 0, sizeof(log));
2990 		log.u_bbr.flex1 = rack->r_ctl.rc_pace_min_segs;
2991 		log.u_bbr.flex3 = rack->r_ctl.rc_pace_max_segs;
2992 		log.u_bbr.flex4 = arg1;
2993 		log.u_bbr.flex5 = arg2;
2994 		log.u_bbr.flex7 = rack->r_ctl.rc_user_set_min_segs;
2995 		log.u_bbr.flex6 = arg3;
2996 		log.u_bbr.flex8 = frm;
2997 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
2998 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
2999 		log.u_bbr.pkts_out = rack->r_ctl.rc_out_at_rto;
3000 		log.u_bbr.applimited = rack->r_ctl.rc_sacked;
3001 		log.u_bbr.delivered = rack->r_ctl.rc_snd_max_at_rto;
3002 		log.u_bbr.pacing_gain = rack->r_must_retran;
3003 		TCP_LOG_EVENTP(tp, NULL, &tptosocket(tp)->so_rcv,
3004 		    &tptosocket(tp)->so_snd,
3005 		    TCP_HDWR_PACE_SIZE, 0, 0, &log, false, &tv);
3006 	}
3007 }
3008 
3009 static void
3010 rack_log_type_just_return(struct tcp_rack *rack, uint32_t cts, uint32_t tlen, uint32_t pacing_delay,
3011 			  uint8_t hpts_calling, int reason, uint32_t cwnd_to_use)
3012 {
3013 	if (tcp_bblogging_on(rack->rc_tp)) {
3014 		union tcp_log_stackspecific log;
3015 		struct timeval tv;
3016 
3017 		memset(&log, 0, sizeof(log));
3018 		log.u_bbr.inhpts = tcp_in_hpts(rack->rc_tp);
3019 		log.u_bbr.flex1 = pacing_delay;
3020 		log.u_bbr.flex2 = rack->r_ctl.rc_hpts_flags;
3021 		log.u_bbr.flex4 = reason;
3022 		if (rack->rack_no_prr)
3023 			log.u_bbr.flex5 = 0;
3024 		else
3025 			log.u_bbr.flex5 = rack->r_ctl.rc_prr_sndcnt;
3026 		log.u_bbr.flex7 = hpts_calling;
3027 		log.u_bbr.flex8 = rack->rc_in_persist;
3028 		log.u_bbr.lt_epoch = cwnd_to_use;
3029 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
3030 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
3031 		log.u_bbr.pkts_out = rack->r_ctl.rc_out_at_rto;
3032 		log.u_bbr.delivered = rack->r_ctl.rc_snd_max_at_rto;
3033 		log.u_bbr.pacing_gain = rack->r_must_retran;
3034 		log.u_bbr.cwnd_gain = rack->rc_has_collapsed;
3035 		log.u_bbr.bw_inuse = rack->r_ctl.current_round;
3036 		log.u_bbr.bw_inuse <<= 32;
3037 		log.u_bbr.bw_inuse |= rack->r_ctl.rc_considered_lost;
3038 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
3039 		    &rack->rc_inp->inp_socket->so_rcv,
3040 		    &rack->rc_inp->inp_socket->so_snd,
3041 		    BBR_LOG_JUSTRET, 0,
3042 		    tlen, &log, false, &tv);
3043 	}
3044 }
3045 
3046 static void
3047 rack_log_to_cancel(struct tcp_rack *rack, int32_t hpts_removed, int line, uint32_t us_cts,
3048 		   struct timeval *tv, uint32_t flags_on_entry)
3049 {
3050 	if (tcp_bblogging_on(rack->rc_tp)) {
3051 		union tcp_log_stackspecific log;
3052 
3053 		memset(&log, 0, sizeof(log));
3054 		log.u_bbr.inhpts = tcp_in_hpts(rack->rc_tp);
3055 		log.u_bbr.flex1 = line;
3056 		log.u_bbr.flex2 = rack->r_ctl.rc_last_output_to;
3057 		log.u_bbr.flex3 = flags_on_entry;
3058 		log.u_bbr.flex4 = us_cts;
3059 		if (rack->rack_no_prr)
3060 			log.u_bbr.flex5 = 0;
3061 		else
3062 			log.u_bbr.flex5 = rack->r_ctl.rc_prr_sndcnt;
3063 		log.u_bbr.flex6 = rack->rc_tp->t_rxtcur;
3064 		log.u_bbr.flex7 = hpts_removed;
3065 		log.u_bbr.flex8 = 1;
3066 		log.u_bbr.applimited = rack->r_ctl.rc_hpts_flags;
3067 		log.u_bbr.timeStamp = us_cts;
3068 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
3069 		log.u_bbr.pkts_out = rack->r_ctl.rc_out_at_rto;
3070 		log.u_bbr.delivered = rack->r_ctl.rc_snd_max_at_rto;
3071 		log.u_bbr.pacing_gain = rack->r_must_retran;
3072 		log.u_bbr.bw_inuse = rack->r_ctl.current_round;
3073 		log.u_bbr.bw_inuse <<= 32;
3074 		log.u_bbr.bw_inuse |= rack->r_ctl.rc_considered_lost;
3075 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
3076 		    &rack->rc_inp->inp_socket->so_rcv,
3077 		    &rack->rc_inp->inp_socket->so_snd,
3078 		    BBR_LOG_TIMERCANC, 0,
3079 		    0, &log, false, tv);
3080 	}
3081 }
3082 
3083 static void
3084 rack_log_alt_to_to_cancel(struct tcp_rack *rack,
3085 			  uint32_t flex1, uint32_t flex2,
3086 			  uint32_t flex3, uint32_t flex4,
3087 			  uint32_t flex5, uint32_t flex6,
3088 			  uint16_t flex7, uint8_t mod)
3089 {
3090 	if (tcp_bblogging_on(rack->rc_tp)) {
3091 		union tcp_log_stackspecific log;
3092 		struct timeval tv;
3093 
3094 		if (mod == 1) {
3095 			/* No you can't use 1, its for the real to cancel */
3096 			return;
3097 		}
3098 		memset(&log, 0, sizeof(log));
3099 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
3100 		log.u_bbr.flex1 = flex1;
3101 		log.u_bbr.flex2 = flex2;
3102 		log.u_bbr.flex3 = flex3;
3103 		log.u_bbr.flex4 = flex4;
3104 		log.u_bbr.flex5 = flex5;
3105 		log.u_bbr.flex6 = flex6;
3106 		log.u_bbr.flex7 = flex7;
3107 		log.u_bbr.flex8 = mod;
3108 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
3109 		    &rack->rc_inp->inp_socket->so_rcv,
3110 		    &rack->rc_inp->inp_socket->so_snd,
3111 		    BBR_LOG_TIMERCANC, 0,
3112 		    0, &log, false, &tv);
3113 	}
3114 }
3115 
3116 static void
3117 rack_log_to_processing(struct tcp_rack *rack, uint32_t cts, int32_t ret, int32_t timers)
3118 {
3119 	if (rack_verbose_logging && tcp_bblogging_on(rack->rc_tp)) {
3120 		union tcp_log_stackspecific log;
3121 		struct timeval tv;
3122 
3123 		memset(&log, 0, sizeof(log));
3124 		log.u_bbr.flex1 = timers;
3125 		log.u_bbr.flex2 = ret;
3126 		log.u_bbr.flex3 = rack->r_ctl.rc_timer_exp;
3127 		log.u_bbr.flex4 = rack->r_ctl.rc_hpts_flags;
3128 		log.u_bbr.flex5 = cts;
3129 		if (rack->rack_no_prr)
3130 			log.u_bbr.flex6 = 0;
3131 		else
3132 			log.u_bbr.flex6 = rack->r_ctl.rc_prr_sndcnt;
3133 		log.u_bbr.pkts_out = rack->r_ctl.rc_out_at_rto;
3134 		log.u_bbr.delivered = rack->r_ctl.rc_snd_max_at_rto;
3135 		log.u_bbr.pacing_gain = rack->r_must_retran;
3136 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
3137 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
3138 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
3139 		    &rack->rc_inp->inp_socket->so_rcv,
3140 		    &rack->rc_inp->inp_socket->so_snd,
3141 		    BBR_LOG_TO_PROCESS, 0,
3142 		    0, &log, false, &tv);
3143 	}
3144 }
3145 
3146 static void
3147 rack_log_to_prr(struct tcp_rack *rack, int frm, int orig_cwnd, int line)
3148 {
3149 	if (tcp_bblogging_on(rack->rc_tp)) {
3150 		union tcp_log_stackspecific log;
3151 		struct timeval tv;
3152 
3153 		memset(&log, 0, sizeof(log));
3154 		log.u_bbr.flex1 = rack->r_ctl.rc_prr_out;
3155 		log.u_bbr.flex2 = rack->r_ctl.rc_prr_recovery_fs;
3156 		if (rack->rack_no_prr)
3157 			log.u_bbr.flex3 = 0;
3158 		else
3159 			log.u_bbr.flex3 = rack->r_ctl.rc_prr_sndcnt;
3160 		log.u_bbr.flex4 = rack->r_ctl.rc_prr_delivered;
3161 		log.u_bbr.flex5 = rack->r_ctl.rc_sacked;
3162 		log.u_bbr.flex6 = rack->r_ctl.rc_holes_rxt;
3163 		log.u_bbr.flex7 = line;
3164 		log.u_bbr.flex8 = frm;
3165 		log.u_bbr.pkts_out = orig_cwnd;
3166 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
3167 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
3168 		log.u_bbr.use_lt_bw = rack->r_ent_rec_ns;
3169 		log.u_bbr.use_lt_bw <<= 1;
3170 		log.u_bbr.use_lt_bw |= rack->r_might_revert;
3171 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
3172 		    &rack->rc_inp->inp_socket->so_rcv,
3173 		    &rack->rc_inp->inp_socket->so_snd,
3174 		    BBR_LOG_BBRUPD, 0,
3175 		    0, &log, false, &tv);
3176 	}
3177 }
3178 
3179 static void
3180 rack_counter_destroy(void)
3181 {
3182 	counter_u64_free(rack_total_bytes);
3183 	counter_u64_free(rack_fto_send);
3184 	counter_u64_free(rack_fto_rsm_send);
3185 	counter_u64_free(rack_nfto_resend);
3186 	counter_u64_free(rack_hw_pace_init_fail);
3187 	counter_u64_free(rack_hw_pace_lost);
3188 	counter_u64_free(rack_non_fto_send);
3189 	counter_u64_free(rack_extended_rfo);
3190 	counter_u64_free(rack_tlp_tot);
3191 	counter_u64_free(rack_tlp_newdata);
3192 	counter_u64_free(rack_tlp_retran);
3193 	counter_u64_free(rack_tlp_retran_bytes);
3194 	counter_u64_free(rack_to_tot);
3195 	counter_u64_free(rack_saw_enobuf);
3196 	counter_u64_free(rack_saw_enobuf_hw);
3197 	counter_u64_free(rack_saw_enetunreach);
3198 	counter_u64_free(rack_hot_alloc);
3199 	counter_u64_free(rack_to_alloc);
3200 	counter_u64_free(rack_to_alloc_hard);
3201 	counter_u64_free(rack_to_alloc_emerg);
3202 	counter_u64_free(rack_to_alloc_limited);
3203 	counter_u64_free(rack_alloc_limited_conns);
3204 	counter_u64_free(rack_split_limited);
3205 	counter_u64_free(rack_multi_single_eq);
3206 	counter_u64_free(rack_rxt_clamps_cwnd);
3207 	counter_u64_free(rack_rxt_clamps_cwnd_uniq);
3208 	counter_u64_free(rack_proc_non_comp_ack);
3209 	counter_u64_free(rack_sack_proc_all);
3210 	counter_u64_free(rack_sack_proc_restart);
3211 	counter_u64_free(rack_sack_proc_short);
3212 	counter_u64_free(rack_input_idle_reduces);
3213 	counter_u64_free(rack_collapsed_win);
3214 	counter_u64_free(rack_collapsed_win_rxt);
3215 	counter_u64_free(rack_collapsed_win_rxt_bytes);
3216 	counter_u64_free(rack_collapsed_win_seen);
3217 	counter_u64_free(rack_try_scwnd);
3218 	counter_u64_free(rack_persists_sends);
3219 	counter_u64_free(rack_persists_acks);
3220 	counter_u64_free(rack_persists_loss);
3221 	counter_u64_free(rack_persists_lost_ends);
3222 #ifdef INVARIANTS
3223 	counter_u64_free(rack_adjust_map_bw);
3224 #endif
3225 	COUNTER_ARRAY_FREE(rack_out_size, TCP_MSS_ACCT_SIZE);
3226 	COUNTER_ARRAY_FREE(rack_opts_arry, RACK_OPTS_SIZE);
3227 }
3228 
3229 static struct rack_sendmap *
3230 rack_alloc(struct tcp_rack *rack)
3231 {
3232 	struct rack_sendmap *rsm;
3233 
3234 	/*
3235 	 * First get the top of the list it in
3236 	 * theory is the "hottest" rsm we have,
3237 	 * possibly just freed by ack processing.
3238 	 */
3239 	if (rack->rc_free_cnt > rack_free_cache) {
3240 		rsm = TAILQ_FIRST(&rack->r_ctl.rc_free);
3241 		TAILQ_REMOVE(&rack->r_ctl.rc_free, rsm, r_tnext);
3242 		counter_u64_add(rack_hot_alloc, 1);
3243 		rack->rc_free_cnt--;
3244 		return (rsm);
3245 	}
3246 	/*
3247 	 * Once we get under our free cache we probably
3248 	 * no longer have a "hot" one available. Lets
3249 	 * get one from UMA.
3250 	 */
3251 	rsm = uma_zalloc(rack_zone, M_NOWAIT);
3252 	if (rsm) {
3253 		rack->r_ctl.rc_num_maps_alloced++;
3254 		counter_u64_add(rack_to_alloc, 1);
3255 		return (rsm);
3256 	}
3257 	/*
3258 	 * Dig in to our aux rsm's (the last two) since
3259 	 * UMA failed to get us one.
3260 	 */
3261 	if (rack->rc_free_cnt) {
3262 		counter_u64_add(rack_to_alloc_emerg, 1);
3263 		rsm = TAILQ_FIRST(&rack->r_ctl.rc_free);
3264 		TAILQ_REMOVE(&rack->r_ctl.rc_free, rsm, r_tnext);
3265 		rack->rc_free_cnt--;
3266 		return (rsm);
3267 	}
3268 	return (NULL);
3269 }
3270 
3271 static struct rack_sendmap *
3272 rack_alloc_full_limit(struct tcp_rack *rack)
3273 {
3274 	if ((V_tcp_map_entries_limit > 0) &&
3275 	    (rack->r_ctl.rc_num_maps_alloced >= V_tcp_map_entries_limit)) {
3276 		counter_u64_add(rack_to_alloc_limited, 1);
3277 		if (!rack->alloc_limit_reported) {
3278 			rack->alloc_limit_reported = 1;
3279 			counter_u64_add(rack_alloc_limited_conns, 1);
3280 		}
3281 		return (NULL);
3282 	}
3283 	return (rack_alloc(rack));
3284 }
3285 
3286 /* wrapper to allocate a sendmap entry, subject to a specific limit */
3287 static struct rack_sendmap *
3288 rack_alloc_limit(struct tcp_rack *rack, uint8_t limit_type)
3289 {
3290 	struct rack_sendmap *rsm;
3291 
3292 	if (limit_type) {
3293 		/* currently there is only one limit type */
3294 		if (rack->r_ctl.rc_split_limit > 0 &&
3295 		    rack->r_ctl.rc_num_split_allocs >= rack->r_ctl.rc_split_limit) {
3296 			counter_u64_add(rack_split_limited, 1);
3297 			if (!rack->alloc_limit_reported) {
3298 				rack->alloc_limit_reported = 1;
3299 				counter_u64_add(rack_alloc_limited_conns, 1);
3300 			}
3301 			return (NULL);
3302 		}
3303 	}
3304 
3305 	/* allocate and mark in the limit type, if set */
3306 	rsm = rack_alloc(rack);
3307 	if (rsm != NULL && limit_type) {
3308 		rsm->r_limit_type = limit_type;
3309 		rack->r_ctl.rc_num_split_allocs++;
3310 	}
3311 	return (rsm);
3312 }
3313 
3314 static void
3315 rack_free_trim(struct tcp_rack *rack)
3316 {
3317 	struct rack_sendmap *rsm;
3318 
3319 	/*
3320 	 * Free up all the tail entries until
3321 	 * we get our list down to the limit.
3322 	 */
3323 	while (rack->rc_free_cnt > rack_free_cache) {
3324 		rsm = TAILQ_LAST(&rack->r_ctl.rc_free, rack_head);
3325 		TAILQ_REMOVE(&rack->r_ctl.rc_free, rsm, r_tnext);
3326 		rack->rc_free_cnt--;
3327 		rack->r_ctl.rc_num_maps_alloced--;
3328 		uma_zfree(rack_zone, rsm);
3329 	}
3330 }
3331 
3332 static void
3333 rack_free(struct tcp_rack *rack, struct rack_sendmap *rsm)
3334 {
3335 	if (rsm->r_flags & RACK_APP_LIMITED) {
3336 		KASSERT((rack->r_ctl.rc_app_limited_cnt > 0),
3337 		    ("app_cnt %u, rsm %p", rack->r_ctl.rc_app_limited_cnt, rsm));
3338 		rack->r_ctl.rc_app_limited_cnt--;
3339 	}
3340 	if (rsm->r_limit_type) {
3341 		/* currently there is only one limit type */
3342 		rack->r_ctl.rc_num_split_allocs--;
3343 	}
3344 	if (rsm == rack->r_ctl.rc_first_appl) {
3345 		rack->r_ctl.cleared_app_ack_seq = rsm->r_end;
3346 		rack->r_ctl.cleared_app_ack = 1;
3347 		if (rack->r_ctl.rc_app_limited_cnt == 0)
3348 			rack->r_ctl.rc_first_appl = NULL;
3349 		else
3350 			rack->r_ctl.rc_first_appl = tqhash_find(rack->r_ctl.tqh, rsm->r_nseq_appl);
3351 	}
3352 	if (rsm == rack->r_ctl.rc_resend)
3353 		rack->r_ctl.rc_resend = NULL;
3354 	if (rsm == rack->r_ctl.rc_end_appl)
3355 		rack->r_ctl.rc_end_appl = NULL;
3356 	if (rack->r_ctl.rc_tlpsend == rsm)
3357 		rack->r_ctl.rc_tlpsend = NULL;
3358 	if (rack->r_ctl.rc_sacklast == rsm)
3359 		rack->r_ctl.rc_sacklast = NULL;
3360 	memset(rsm, 0, sizeof(struct rack_sendmap));
3361 	/* Make sure we are not going to overrun our count limit of 0xff */
3362 	if ((rack->rc_free_cnt + 1) > RACK_FREE_CNT_MAX) {
3363 		rack_free_trim(rack);
3364 	}
3365 	TAILQ_INSERT_HEAD(&rack->r_ctl.rc_free, rsm, r_tnext);
3366 	rack->rc_free_cnt++;
3367 }
3368 
3369 static uint32_t
3370 rack_get_measure_window(struct tcpcb *tp, struct tcp_rack *rack)
3371 {
3372 	uint64_t srtt, bw, len, tim;
3373 	uint32_t segsiz, def_len, minl;
3374 
3375 	segsiz = min(ctf_fixed_maxseg(tp), rack->r_ctl.rc_pace_min_segs);
3376 	def_len = rack_def_data_window * segsiz;
3377 	if (rack->rc_gp_filled == 0) {
3378 		/*
3379 		 * We have no measurement (IW is in flight?) so
3380 		 * we can only guess using our data_window sysctl
3381 		 * value (usually 20MSS).
3382 		 */
3383 		return (def_len);
3384 	}
3385 	/*
3386 	 * Now we have a number of factors to consider.
3387 	 *
3388 	 * 1) We have a desired BDP which is usually
3389 	 *    at least 2.
3390 	 * 2) We have a minimum number of rtt's usually 1 SRTT
3391 	 *    but we allow it too to be more.
3392 	 * 3) We want to make sure a measurement last N useconds (if
3393 	 *    we have set rack_min_measure_usec.
3394 	 *
3395 	 * We handle the first concern here by trying to create a data
3396 	 * window of max(rack_def_data_window, DesiredBDP). The
3397 	 * second concern we handle in not letting the measurement
3398 	 * window end normally until at least the required SRTT's
3399 	 * have gone by which is done further below in
3400 	 * rack_enough_for_measurement(). Finally the third concern
3401 	 * we also handle here by calculating how long that time
3402 	 * would take at the current BW and then return the
3403 	 * max of our first calculation and that length. Note
3404 	 * that if rack_min_measure_usec is 0, we don't deal
3405 	 * with concern 3. Also for both Concern 1 and 3 an
3406 	 * application limited period could end the measurement
3407 	 * earlier.
3408 	 *
3409 	 * So lets calculate the BDP with the "known" b/w using
3410 	 * the SRTT as our rtt and then multiply it by the goal.
3411 	 */
3412 	bw = rack_get_bw(rack);
3413 	srtt = (uint64_t)tp->t_srtt;
3414 	len = bw * srtt;
3415 	len /= (uint64_t)HPTS_USEC_IN_SEC;
3416 	len *= max(1, rack_goal_bdp);
3417 	/* Now we need to round up to the nearest MSS */
3418 	len = roundup(len, segsiz);
3419 	if (rack_min_measure_usec) {
3420 		/* Now calculate our min length for this b/w */
3421 		tim = rack_min_measure_usec;
3422 		minl = (tim * bw) / (uint64_t)HPTS_USEC_IN_SEC;
3423 		if (minl == 0)
3424 			minl = 1;
3425 		minl = roundup(minl, segsiz);
3426 		if (len < minl)
3427 			len = minl;
3428 	}
3429 	/*
3430 	 * Now if we have a very small window we want
3431 	 * to attempt to get the window that is
3432 	 * as small as possible. This happens on
3433 	 * low b/w connections and we don't want to
3434 	 * span huge numbers of rtt's between measurements.
3435 	 *
3436 	 * We basically include 2 over our "MIN window" so
3437 	 * that the measurement can be shortened (possibly) by
3438 	 * an ack'ed packet.
3439 	 */
3440 	if (len < def_len)
3441 		return (max((uint32_t)len, ((MIN_GP_WIN+2) * segsiz)));
3442 	else
3443 		return (max((uint32_t)len, def_len));
3444 
3445 }
3446 
3447 static int
3448 rack_enough_for_measurement(struct tcpcb *tp, struct tcp_rack *rack, tcp_seq th_ack, uint8_t *quality)
3449 {
3450 	uint32_t tim, srtts, segsiz;
3451 
3452 	/*
3453 	 * Has enough time passed for the GP measurement to be valid?
3454 	 */
3455 	if (SEQ_LT(th_ack, tp->gput_seq)) {
3456 		/* Not enough bytes yet */
3457 		return (0);
3458 	}
3459 	if ((tp->snd_max == tp->snd_una) ||
3460 	    (th_ack == tp->snd_max)){
3461 		/*
3462 		 * All is acked quality of all acked is
3463 		 * usually low or medium, but we in theory could split
3464 		 * all acked into two cases, where you got
3465 		 * a signifigant amount of your window and
3466 		 * where you did not. For now we leave it
3467 		 * but it is something to contemplate in the
3468 		 * future. The danger here is that delayed ack
3469 		 * is effecting the last byte (which is a 50:50 chance).
3470 		 */
3471 		*quality = RACK_QUALITY_ALLACKED;
3472 		return (1);
3473 	}
3474 	if (SEQ_GEQ(th_ack,  tp->gput_ack)) {
3475 		/*
3476 		 * We obtained our entire window of data we wanted
3477 		 * no matter if we are in recovery or not then
3478 		 * its ok since expanding the window does not
3479 		 * make things fuzzy (or at least not as much).
3480 		 */
3481 		*quality = RACK_QUALITY_HIGH;
3482 		return (1);
3483 	}
3484 	segsiz = min(ctf_fixed_maxseg(tp), rack->r_ctl.rc_pace_min_segs);
3485 	if (SEQ_LT(th_ack, tp->gput_ack) &&
3486 	    ((th_ack - tp->gput_seq) < max(rc_init_window(rack), (MIN_GP_WIN * segsiz)))) {
3487 		/* Not enough bytes yet */
3488 		return (0);
3489 	}
3490 	if (rack->r_ctl.rc_first_appl &&
3491 	    (SEQ_GEQ(th_ack, rack->r_ctl.rc_first_appl->r_end))) {
3492 		/*
3493 		 * We are up to the app limited send point
3494 		 * we have to measure irrespective of the time..
3495 		 */
3496 		*quality = RACK_QUALITY_APPLIMITED;
3497 		return (1);
3498 	}
3499 	/* Now what about time? */
3500 	srtts = (rack->r_ctl.rc_gp_srtt * rack_min_srtts);
3501 	tim = tcp_tv_to_usec(&rack->r_ctl.act_rcv_time) - tp->gput_ts;
3502 	if ((tim >= srtts) && (IN_RECOVERY(rack->rc_tp->t_flags) == 0)) {
3503 		/*
3504 		 * We do not allow a measurement if we are in recovery
3505 		 * that would shrink the goodput window we wanted.
3506 		 * This is to prevent cloudyness of when the last send
3507 		 * was actually made.
3508 		 */
3509 		*quality = RACK_QUALITY_HIGH;
3510 		return (1);
3511 	}
3512 	/* Nope not even a full SRTT has passed */
3513 	return (0);
3514 }
3515 
3516 static void
3517 rack_log_timely(struct tcp_rack *rack,
3518 		uint32_t logged, uint64_t cur_bw, uint64_t low_bnd,
3519 		uint64_t up_bnd, int line, uint8_t method)
3520 {
3521 	if (tcp_bblogging_on(rack->rc_tp)) {
3522 		union tcp_log_stackspecific log;
3523 		struct timeval tv;
3524 
3525 		memset(&log, 0, sizeof(log));
3526 		log.u_bbr.flex1 = logged;
3527 		log.u_bbr.flex2 = rack->rc_gp_timely_inc_cnt;
3528 		log.u_bbr.flex2 <<= 4;
3529 		log.u_bbr.flex2 |= rack->rc_gp_timely_dec_cnt;
3530 		log.u_bbr.flex2 <<= 4;
3531 		log.u_bbr.flex2 |= rack->rc_gp_incr;
3532 		log.u_bbr.flex2 <<= 4;
3533 		log.u_bbr.flex2 |= rack->rc_gp_bwred;
3534 		log.u_bbr.flex3 = rack->rc_gp_incr;
3535 		log.u_bbr.flex4 = rack->r_ctl.rack_per_of_gp_ss;
3536 		log.u_bbr.flex5 = rack->r_ctl.rack_per_of_gp_ca;
3537 		log.u_bbr.flex6 = rack->r_ctl.rack_per_of_gp_rec;
3538 		log.u_bbr.flex7 = rack->rc_gp_bwred;
3539 		log.u_bbr.flex8 = method;
3540 		log.u_bbr.cur_del_rate = cur_bw;
3541 		log.u_bbr.delRate = low_bnd;
3542 		log.u_bbr.bw_inuse = up_bnd;
3543 		log.u_bbr.rttProp = rack_get_bw(rack);
3544 		log.u_bbr.pkt_epoch = line;
3545 		log.u_bbr.pkts_out = rack->r_ctl.rc_rtt_diff;
3546 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
3547 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
3548 		log.u_bbr.epoch = rack->r_ctl.rc_gp_srtt;
3549 		log.u_bbr.lt_epoch = rack->r_ctl.rc_prev_gp_srtt;
3550 		log.u_bbr.cwnd_gain = rack->rc_dragged_bottom;
3551 		log.u_bbr.cwnd_gain <<= 1;
3552 		log.u_bbr.cwnd_gain |= rack->rc_gp_saw_rec;
3553 		log.u_bbr.cwnd_gain <<= 1;
3554 		log.u_bbr.cwnd_gain |= rack->rc_gp_saw_ss;
3555 		log.u_bbr.cwnd_gain <<= 1;
3556 		log.u_bbr.cwnd_gain |= rack->rc_gp_saw_ca;
3557 		log.u_bbr.lost = rack->r_ctl.rc_loss_count;
3558 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
3559 		    &rack->rc_inp->inp_socket->so_rcv,
3560 		    &rack->rc_inp->inp_socket->so_snd,
3561 		    TCP_TIMELY_WORK, 0,
3562 		    0, &log, false, &tv);
3563 	}
3564 }
3565 
3566 static int
3567 rack_bw_can_be_raised(struct tcp_rack *rack, uint64_t cur_bw, uint64_t last_bw_est, uint16_t mult)
3568 {
3569 	/*
3570 	 * Before we increase we need to know if
3571 	 * the estimate just made was less than
3572 	 * our pacing goal (i.e. (cur_bw * mult) > last_bw_est)
3573 	 *
3574 	 * If we already are pacing at a fast enough
3575 	 * rate to push us faster there is no sense of
3576 	 * increasing.
3577 	 *
3578 	 * We first caculate our actual pacing rate (ss or ca multiplier
3579 	 * times our cur_bw).
3580 	 *
3581 	 * Then we take the last measured rate and multipy by our
3582 	 * maximum pacing overage to give us a max allowable rate.
3583 	 *
3584 	 * If our act_rate is smaller than our max_allowable rate
3585 	 * then we should increase. Else we should hold steady.
3586 	 *
3587 	 */
3588 	uint64_t act_rate, max_allow_rate;
3589 
3590 	if (rack_timely_no_stopping)
3591 		return (1);
3592 
3593 	if ((cur_bw == 0) || (last_bw_est == 0)) {
3594 		/*
3595 		 * Initial startup case or
3596 		 * everything is acked case.
3597 		 */
3598 		rack_log_timely(rack,  mult, cur_bw, 0, 0,
3599 				__LINE__, 9);
3600 		return (1);
3601 	}
3602 	if (mult <= 100) {
3603 		/*
3604 		 * We can always pace at or slightly above our rate.
3605 		 */
3606 		rack_log_timely(rack,  mult, cur_bw, 0, 0,
3607 				__LINE__, 9);
3608 		return (1);
3609 	}
3610 	act_rate = cur_bw * (uint64_t)mult;
3611 	act_rate /= 100;
3612 	max_allow_rate = last_bw_est * ((uint64_t)rack_max_per_above + (uint64_t)100);
3613 	max_allow_rate /= 100;
3614 	if (act_rate < max_allow_rate) {
3615 		/*
3616 		 * Here the rate we are actually pacing at
3617 		 * is smaller than 10% above our last measurement.
3618 		 * This means we are pacing below what we would
3619 		 * like to try to achieve (plus some wiggle room).
3620 		 */
3621 		rack_log_timely(rack,  mult, cur_bw, act_rate, max_allow_rate,
3622 				__LINE__, 9);
3623 		return (1);
3624 	} else {
3625 		/*
3626 		 * Here we are already pacing at least rack_max_per_above(10%)
3627 		 * what we are getting back. This indicates most likely
3628 		 * that we are being limited (cwnd/rwnd/app) and can't
3629 		 * get any more b/w. There is no sense of trying to
3630 		 * raise up the pacing rate its not speeding us up
3631 		 * and we already are pacing faster than we are getting.
3632 		 */
3633 		rack_log_timely(rack,  mult, cur_bw, act_rate, max_allow_rate,
3634 				__LINE__, 8);
3635 		return (0);
3636 	}
3637 }
3638 
3639 static void
3640 rack_validate_multipliers_at_or_above100(struct tcp_rack *rack)
3641 {
3642 	/*
3643 	 * When we drag bottom, we want to assure
3644 	 * that no multiplier is below 1.0, if so
3645 	 * we want to restore it to at least that.
3646 	 */
3647 	if (rack->r_ctl.rack_per_of_gp_rec  < 100) {
3648 		/* This is unlikely we usually do not touch recovery */
3649 		rack->r_ctl.rack_per_of_gp_rec = 100;
3650 	}
3651 	if (rack->r_ctl.rack_per_of_gp_ca < 100) {
3652 		rack->r_ctl.rack_per_of_gp_ca = 100;
3653 	}
3654 	if (rack->r_ctl.rack_per_of_gp_ss < 100) {
3655 		rack->r_ctl.rack_per_of_gp_ss = 100;
3656 	}
3657 }
3658 
3659 static void
3660 rack_validate_multipliers_at_or_below_100(struct tcp_rack *rack)
3661 {
3662 	if (rack->r_ctl.rack_per_of_gp_ca > 100) {
3663 		rack->r_ctl.rack_per_of_gp_ca = 100;
3664 	}
3665 	if (rack->r_ctl.rack_per_of_gp_ss > 100) {
3666 		rack->r_ctl.rack_per_of_gp_ss = 100;
3667 	}
3668 }
3669 
3670 static void
3671 rack_increase_bw_mul(struct tcp_rack *rack, int timely_says, uint64_t cur_bw, uint64_t last_bw_est, int override)
3672 {
3673 	int32_t  calc, logged, plus;
3674 
3675 	logged = 0;
3676 
3677 	if (rack->rc_skip_timely)
3678 		return;
3679 	if (override) {
3680 		/*
3681 		 * override is passed when we are
3682 		 * loosing b/w and making one last
3683 		 * gasp at trying to not loose out
3684 		 * to a new-reno flow.
3685 		 */
3686 		goto extra_boost;
3687 	}
3688 	/* In classic timely we boost by 5x if we have 5 increases in a row, lets not */
3689 	if (rack->rc_gp_incr &&
3690 	    ((rack->rc_gp_timely_inc_cnt + 1) >= RACK_TIMELY_CNT_BOOST)) {
3691 		/*
3692 		 * Reset and get 5 strokes more before the boost. Note
3693 		 * that the count is 0 based so we have to add one.
3694 		 */
3695 extra_boost:
3696 		plus = (uint32_t)rack_gp_increase_per * RACK_TIMELY_CNT_BOOST;
3697 		rack->rc_gp_timely_inc_cnt = 0;
3698 	} else
3699 		plus = (uint32_t)rack_gp_increase_per;
3700 	/* Must be at least 1% increase for true timely increases */
3701 	if ((plus < 1) &&
3702 	    ((rack->r_ctl.rc_rtt_diff <= 0) || (timely_says <= 0)))
3703 		plus = 1;
3704 	if (rack->rc_gp_saw_rec &&
3705 	    (rack->rc_gp_no_rec_chg == 0) &&
3706 	    rack_bw_can_be_raised(rack, cur_bw, last_bw_est,
3707 				  rack->r_ctl.rack_per_of_gp_rec)) {
3708 		/* We have been in recovery ding it too */
3709 		calc = rack->r_ctl.rack_per_of_gp_rec + plus;
3710 		if (calc > 0xffff)
3711 			calc = 0xffff;
3712 		logged |= 1;
3713 		rack->r_ctl.rack_per_of_gp_rec = (uint16_t)calc;
3714 		if (rack->r_ctl.rack_per_upper_bound_ca &&
3715 		    (rack->rc_dragged_bottom == 0) &&
3716 		    (rack->r_ctl.rack_per_of_gp_rec > rack->r_ctl.rack_per_upper_bound_ca))
3717 			rack->r_ctl.rack_per_of_gp_rec = rack->r_ctl.rack_per_upper_bound_ca;
3718 	}
3719 	if (rack->rc_gp_saw_ca &&
3720 	    (rack->rc_gp_saw_ss == 0) &&
3721 	    rack_bw_can_be_raised(rack, cur_bw, last_bw_est,
3722 				  rack->r_ctl.rack_per_of_gp_ca)) {
3723 		/* In CA */
3724 		calc = rack->r_ctl.rack_per_of_gp_ca + plus;
3725 		if (calc > 0xffff)
3726 			calc = 0xffff;
3727 		logged |= 2;
3728 		rack->r_ctl.rack_per_of_gp_ca = (uint16_t)calc;
3729 		if (rack->r_ctl.rack_per_upper_bound_ca &&
3730 		    (rack->rc_dragged_bottom == 0) &&
3731 		    (rack->r_ctl.rack_per_of_gp_ca > rack->r_ctl.rack_per_upper_bound_ca))
3732 			rack->r_ctl.rack_per_of_gp_ca = rack->r_ctl.rack_per_upper_bound_ca;
3733 	}
3734 	if (rack->rc_gp_saw_ss &&
3735 	    rack_bw_can_be_raised(rack, cur_bw, last_bw_est,
3736 				  rack->r_ctl.rack_per_of_gp_ss)) {
3737 		/* In SS */
3738 		calc = rack->r_ctl.rack_per_of_gp_ss + plus;
3739 		if (calc > 0xffff)
3740 			calc = 0xffff;
3741 		rack->r_ctl.rack_per_of_gp_ss = (uint16_t)calc;
3742 		if (rack->r_ctl.rack_per_upper_bound_ss &&
3743 		    (rack->rc_dragged_bottom == 0) &&
3744 		    (rack->r_ctl.rack_per_of_gp_ss > rack->r_ctl.rack_per_upper_bound_ss))
3745 			rack->r_ctl.rack_per_of_gp_ss = rack->r_ctl.rack_per_upper_bound_ss;
3746 		logged |= 4;
3747 	}
3748 	if (logged &&
3749 	    (rack->rc_gp_incr == 0)){
3750 		/* Go into increment mode */
3751 		rack->rc_gp_incr = 1;
3752 		rack->rc_gp_timely_inc_cnt = 0;
3753 	}
3754 	if (rack->rc_gp_incr &&
3755 	    logged &&
3756 	    (rack->rc_gp_timely_inc_cnt < RACK_TIMELY_CNT_BOOST)) {
3757 		rack->rc_gp_timely_inc_cnt++;
3758 	}
3759 	rack_log_timely(rack,  logged, plus, 0, 0,
3760 			__LINE__, 1);
3761 }
3762 
3763 static uint32_t
3764 rack_get_decrease(struct tcp_rack *rack, uint32_t curper, int32_t rtt_diff)
3765 {
3766 	/*-
3767 	 * norm_grad = rtt_diff / minrtt;
3768 	 * new_per = curper * (1 - B * norm_grad)
3769 	 *
3770 	 * B = rack_gp_decrease_per (default 80%)
3771 	 * rtt_dif = input var current rtt-diff
3772 	 * curper = input var current percentage
3773 	 * minrtt = from rack filter
3774 	 *
3775 	 * In order to do the floating point calculations above we
3776 	 * do an integer conversion. The code looks confusing so let me
3777 	 * translate it into something that use more variables and
3778 	 * is clearer for us humans :)
3779 	 *
3780 	 * uint64_t norm_grad, inverse, reduce_by, final_result;
3781 	 * uint32_t perf;
3782 	 *
3783 	 * norm_grad = (((uint64_t)rtt_diff * 1000000) /
3784 	 *             (uint64_t)get_filter_small(&rack->r_ctl.rc_gp_min_rtt));
3785 	 * inverse = ((uint64_t)rack_gp_decrease * (uint64_t)1000000) * norm_grad;
3786 	 * inverse /= 1000000;
3787 	 * reduce_by = (1000000 - inverse);
3788 	 * final_result = (cur_per * reduce_by) / 1000000;
3789 	 * perf = (uint32_t)final_result;
3790 	 */
3791 	uint64_t perf;
3792 
3793 	perf = (((uint64_t)curper * ((uint64_t)1000000 -
3794 		    ((uint64_t)rack_gp_decrease_per * (uint64_t)10000 *
3795 		     (((uint64_t)rtt_diff * (uint64_t)1000000)/
3796 		      (uint64_t)get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt)))/
3797 		     (uint64_t)1000000)) /
3798 		(uint64_t)1000000);
3799 	if (perf > curper) {
3800 		/* TSNH */
3801 		perf = curper - 1;
3802 	}
3803 	return ((uint32_t)perf);
3804 }
3805 
3806 static uint32_t
3807 rack_decrease_highrtt(struct tcp_rack *rack, uint32_t curper, uint32_t rtt)
3808 {
3809 	/*
3810 	 *                                   highrttthresh
3811 	 * result = curper * (1 - (B * ( 1 -  ------          ))
3812 	 *                                     gp_srtt
3813 	 *
3814 	 * B = rack_gp_decrease_per (default .8 i.e. 80)
3815 	 * highrttthresh = filter_min * rack_gp_rtt_maxmul
3816 	 */
3817 	uint64_t perf;
3818 	uint32_t highrttthresh;
3819 
3820 	highrttthresh = get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt) * rack_gp_rtt_maxmul;
3821 
3822 	perf = (((uint64_t)curper * ((uint64_t)1000000 -
3823 				     ((uint64_t)rack_gp_decrease_per * ((uint64_t)1000000 -
3824 					((uint64_t)highrttthresh * (uint64_t)1000000) /
3825 						    (uint64_t)rtt)) / 100)) /(uint64_t)1000000);
3826 	if (tcp_bblogging_on(rack->rc_tp)) {
3827 		uint64_t log1;
3828 
3829 		log1 = rtt;
3830 		log1 <<= 32;
3831 		log1 |= highrttthresh;
3832 		rack_log_timely(rack,
3833 				rack_gp_decrease_per,
3834 				(uint64_t)curper,
3835 				log1,
3836 				perf,
3837 				__LINE__,
3838 				15);
3839 	}
3840 	return (perf);
3841 }
3842 
3843 static void
3844 rack_decrease_bw_mul(struct tcp_rack *rack, int timely_says, uint32_t rtt, int32_t rtt_diff)
3845 {
3846 	uint64_t logvar, logvar2, logvar3;
3847 	uint32_t logged, new_per, ss_red, ca_red, rec_red, alt, val;
3848 
3849 	if (rack->rc_skip_timely)
3850 		return;
3851 	if (rack->rc_gp_incr) {
3852 		/* Turn off increment counting */
3853 		rack->rc_gp_incr = 0;
3854 		rack->rc_gp_timely_inc_cnt = 0;
3855 	}
3856 	ss_red = ca_red = rec_red = 0;
3857 	logged = 0;
3858 	/* Calculate the reduction value */
3859 	if (rtt_diff < 0) {
3860 		rtt_diff *= -1;
3861 	}
3862 	/* Must be at least 1% reduction */
3863 	if (rack->rc_gp_saw_rec && (rack->rc_gp_no_rec_chg == 0)) {
3864 		/* We have been in recovery ding it too */
3865 		if (timely_says == 2) {
3866 			new_per = rack_decrease_highrtt(rack, rack->r_ctl.rack_per_of_gp_rec, rtt);
3867 			alt = rack_get_decrease(rack, rack->r_ctl.rack_per_of_gp_rec, rtt_diff);
3868 			if (alt < new_per)
3869 				val = alt;
3870 			else
3871 				val = new_per;
3872 		} else
3873 			 val = new_per = alt = rack_get_decrease(rack, rack->r_ctl.rack_per_of_gp_rec, rtt_diff);
3874 		if (rack->r_ctl.rack_per_of_gp_rec > val) {
3875 			rec_red = (rack->r_ctl.rack_per_of_gp_rec - val);
3876 			rack->r_ctl.rack_per_of_gp_rec = (uint16_t)val;
3877 		} else {
3878 			rack->r_ctl.rack_per_of_gp_rec = rack_per_lower_bound;
3879 			rec_red = 0;
3880 		}
3881 		if (rack_per_lower_bound > rack->r_ctl.rack_per_of_gp_rec)
3882 			rack->r_ctl.rack_per_of_gp_rec = rack_per_lower_bound;
3883 		logged |= 1;
3884 	}
3885 	if (rack->rc_gp_saw_ss) {
3886 		/* Sent in SS */
3887 		if (timely_says == 2) {
3888 			new_per = rack_decrease_highrtt(rack, rack->r_ctl.rack_per_of_gp_ss, rtt);
3889 			alt = rack_get_decrease(rack, rack->r_ctl.rack_per_of_gp_ss, rtt_diff);
3890 			if (alt < new_per)
3891 				val = alt;
3892 			else
3893 				val = new_per;
3894 		} else
3895 			val = new_per = alt = rack_get_decrease(rack, rack->r_ctl.rack_per_of_gp_ss, rtt_diff);
3896 		if (rack->r_ctl.rack_per_of_gp_ss > new_per) {
3897 			ss_red = rack->r_ctl.rack_per_of_gp_ss - val;
3898 			rack->r_ctl.rack_per_of_gp_ss = (uint16_t)val;
3899 		} else {
3900 			ss_red = new_per;
3901 			rack->r_ctl.rack_per_of_gp_ss = rack_per_lower_bound;
3902 			logvar = new_per;
3903 			logvar <<= 32;
3904 			logvar |= alt;
3905 			logvar2 = (uint32_t)rtt;
3906 			logvar2 <<= 32;
3907 			logvar2 |= (uint32_t)rtt_diff;
3908 			logvar3 = rack_gp_rtt_maxmul;
3909 			logvar3 <<= 32;
3910 			logvar3 |= get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt);
3911 			rack_log_timely(rack, timely_says,
3912 					logvar2, logvar3,
3913 					logvar, __LINE__, 10);
3914 		}
3915 		if (rack_per_lower_bound > rack->r_ctl.rack_per_of_gp_ss)
3916 			rack->r_ctl.rack_per_of_gp_ss = rack_per_lower_bound;
3917 		logged |= 4;
3918 	} else if (rack->rc_gp_saw_ca) {
3919 		/* Sent in CA */
3920 		if (timely_says == 2) {
3921 			new_per = rack_decrease_highrtt(rack, rack->r_ctl.rack_per_of_gp_ca, rtt);
3922 			alt = rack_get_decrease(rack, rack->r_ctl.rack_per_of_gp_ca, rtt_diff);
3923 			if (alt < new_per)
3924 				val = alt;
3925 			else
3926 				val = new_per;
3927 		} else
3928 			val = new_per = alt = rack_get_decrease(rack, rack->r_ctl.rack_per_of_gp_ca, rtt_diff);
3929 		if (rack->r_ctl.rack_per_of_gp_ca > val) {
3930 			ca_red = rack->r_ctl.rack_per_of_gp_ca - val;
3931 			rack->r_ctl.rack_per_of_gp_ca = (uint16_t)val;
3932 		} else {
3933 			rack->r_ctl.rack_per_of_gp_ca = rack_per_lower_bound;
3934 			ca_red = 0;
3935 			logvar = new_per;
3936 			logvar <<= 32;
3937 			logvar |= alt;
3938 			logvar2 = (uint32_t)rtt;
3939 			logvar2 <<= 32;
3940 			logvar2 |= (uint32_t)rtt_diff;
3941 			logvar3 = rack_gp_rtt_maxmul;
3942 			logvar3 <<= 32;
3943 			logvar3 |= get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt);
3944 			rack_log_timely(rack, timely_says,
3945 					logvar2, logvar3,
3946 					logvar, __LINE__, 10);
3947 		}
3948 		if (rack_per_lower_bound > rack->r_ctl.rack_per_of_gp_ca)
3949 			rack->r_ctl.rack_per_of_gp_ca = rack_per_lower_bound;
3950 		logged |= 2;
3951 	}
3952 	if (rack->rc_gp_timely_dec_cnt < 0x7) {
3953 		rack->rc_gp_timely_dec_cnt++;
3954 		if (rack_timely_dec_clear &&
3955 		    (rack->rc_gp_timely_dec_cnt == rack_timely_dec_clear))
3956 			rack->rc_gp_timely_dec_cnt = 0;
3957 	}
3958 	logvar = ss_red;
3959 	logvar <<= 32;
3960 	logvar |= ca_red;
3961 	rack_log_timely(rack,  logged, rec_red, rack_per_lower_bound, logvar,
3962 			__LINE__, 2);
3963 }
3964 
3965 static void
3966 rack_log_rtt_shrinks(struct tcp_rack *rack, uint32_t us_cts,
3967 		     uint32_t rtt, uint32_t line, uint8_t reas)
3968 {
3969 	if (tcp_bblogging_on(rack->rc_tp)) {
3970 		union tcp_log_stackspecific log;
3971 		struct timeval tv;
3972 
3973 		memset(&log, 0, sizeof(log));
3974 		log.u_bbr.flex1 = line;
3975 		log.u_bbr.flex2 = rack->r_ctl.rc_time_probertt_starts;
3976 		log.u_bbr.flex3 = rack->r_ctl.rc_lower_rtt_us_cts;
3977 		log.u_bbr.flex4 = rack->r_ctl.rack_per_of_gp_ss;
3978 		log.u_bbr.flex5 = rtt;
3979 		log.u_bbr.flex6 = rack->rc_highly_buffered;
3980 		log.u_bbr.flex6 <<= 1;
3981 		log.u_bbr.flex6 |= rack->forced_ack;
3982 		log.u_bbr.flex6 <<= 1;
3983 		log.u_bbr.flex6 |= rack->rc_gp_dyn_mul;
3984 		log.u_bbr.flex6 <<= 1;
3985 		log.u_bbr.flex6 |= rack->in_probe_rtt;
3986 		log.u_bbr.flex6 <<= 1;
3987 		log.u_bbr.flex6 |= rack->measure_saw_probe_rtt;
3988 		log.u_bbr.flex7 = rack->r_ctl.rack_per_of_gp_probertt;
3989 		log.u_bbr.pacing_gain = rack->r_ctl.rack_per_of_gp_ca;
3990 		log.u_bbr.cwnd_gain = rack->r_ctl.rack_per_of_gp_rec;
3991 		log.u_bbr.flex8 = reas;
3992 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
3993 		log.u_bbr.delRate = rack_get_bw(rack);
3994 		log.u_bbr.cur_del_rate = rack->r_ctl.rc_highest_us_rtt;
3995 		log.u_bbr.cur_del_rate <<= 32;
3996 		log.u_bbr.cur_del_rate |= rack->r_ctl.rc_lowest_us_rtt;
3997 		log.u_bbr.applimited = rack->r_ctl.rc_time_probertt_entered;
3998 		log.u_bbr.pkts_out = rack->r_ctl.rc_rtt_diff;
3999 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
4000 		log.u_bbr.epoch = rack->r_ctl.rc_gp_srtt;
4001 		log.u_bbr.lt_epoch = rack->r_ctl.rc_prev_gp_srtt;
4002 		log.u_bbr.pkt_epoch = rack->r_ctl.rc_lower_rtt_us_cts;
4003 		log.u_bbr.delivered = rack->r_ctl.rc_target_probertt_flight;
4004 		log.u_bbr.lost = get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt);
4005 		log.u_bbr.rttProp = us_cts;
4006 		log.u_bbr.rttProp <<= 32;
4007 		log.u_bbr.rttProp |= rack->r_ctl.rc_entry_gp_rtt;
4008 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
4009 		    &rack->rc_inp->inp_socket->so_rcv,
4010 		    &rack->rc_inp->inp_socket->so_snd,
4011 		    BBR_LOG_RTT_SHRINKS, 0,
4012 		    0, &log, false, &rack->r_ctl.act_rcv_time);
4013 	}
4014 }
4015 
4016 static void
4017 rack_set_prtt_target(struct tcp_rack *rack, uint32_t segsiz, uint32_t rtt)
4018 {
4019 	uint64_t bwdp;
4020 
4021 	bwdp = rack_get_bw(rack);
4022 	bwdp *= (uint64_t)rtt;
4023 	bwdp /= (uint64_t)HPTS_USEC_IN_SEC;
4024 	rack->r_ctl.rc_target_probertt_flight = roundup((uint32_t)bwdp, segsiz);
4025 	if (rack->r_ctl.rc_target_probertt_flight < (segsiz * rack_timely_min_segs)) {
4026 		/*
4027 		 * A window protocol must be able to have 4 packets
4028 		 * outstanding as the floor in order to function
4029 		 * (especially considering delayed ack :D).
4030 		 */
4031 		rack->r_ctl.rc_target_probertt_flight = (segsiz * rack_timely_min_segs);
4032 	}
4033 }
4034 
4035 static void
4036 rack_enter_probertt(struct tcp_rack *rack, uint32_t us_cts)
4037 {
4038 	/**
4039 	 * ProbeRTT is a bit different in rack_pacing than in
4040 	 * BBR. It is like BBR in that it uses the lowering of
4041 	 * the RTT as a signal that we saw something new and
4042 	 * counts from there for how long between. But it is
4043 	 * different in that its quite simple. It does not
4044 	 * play with the cwnd and wait until we get down
4045 	 * to N segments outstanding and hold that for
4046 	 * 200ms. Instead it just sets the pacing reduction
4047 	 * rate to a set percentage (70 by default) and hold
4048 	 * that for a number of recent GP Srtt's.
4049 	 */
4050 	uint32_t segsiz;
4051 
4052 	rack->r_ctl.rc_lower_rtt_us_cts = us_cts;
4053 	if (rack->rc_gp_dyn_mul == 0)
4054 		return;
4055 
4056 	if (rack->rc_tp->snd_max == rack->rc_tp->snd_una) {
4057 		/* We are idle */
4058 		return;
4059 	}
4060 	if ((rack->rc_tp->t_flags & TF_GPUTINPROG) &&
4061 	    SEQ_GT(rack->rc_tp->snd_una, rack->rc_tp->gput_seq)) {
4062 		/*
4063 		 * Stop the goodput now, the idea here is
4064 		 * that future measurements with in_probe_rtt
4065 		 * won't register if they are not greater so
4066 		 * we want to get what info (if any) is available
4067 		 * now.
4068 		 */
4069 		rack_do_goodput_measurement(rack->rc_tp, rack,
4070 					    rack->rc_tp->snd_una, __LINE__,
4071 					    RACK_QUALITY_PROBERTT);
4072 	}
4073 	rack->r_ctl.rack_per_of_gp_probertt = rack_per_of_gp_probertt;
4074 	rack->r_ctl.rc_time_probertt_entered = us_cts;
4075 	segsiz = min(ctf_fixed_maxseg(rack->rc_tp),
4076 		     rack->r_ctl.rc_pace_min_segs);
4077 	rack->in_probe_rtt = 1;
4078 	rack->measure_saw_probe_rtt = 1;
4079 	rack->r_ctl.rc_time_probertt_starts = 0;
4080 	rack->r_ctl.rc_entry_gp_rtt = rack->r_ctl.rc_gp_srtt;
4081 	if (rack_probertt_use_min_rtt_entry)
4082 		rack_set_prtt_target(rack, segsiz, get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt));
4083 	else
4084 		rack_set_prtt_target(rack, segsiz, rack->r_ctl.rc_gp_srtt);
4085 	rack_log_rtt_shrinks(rack,  us_cts,  get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt),
4086 			     __LINE__, RACK_RTTS_ENTERPROBE);
4087 }
4088 
4089 static void
4090 rack_exit_probertt(struct tcp_rack *rack, uint32_t us_cts)
4091 {
4092 	struct rack_sendmap *rsm;
4093 	uint32_t segsiz;
4094 
4095 	segsiz = min(ctf_fixed_maxseg(rack->rc_tp),
4096 		     rack->r_ctl.rc_pace_min_segs);
4097 	rack->in_probe_rtt = 0;
4098 	if ((rack->rc_tp->t_flags & TF_GPUTINPROG) &&
4099 	    SEQ_GT(rack->rc_tp->snd_una, rack->rc_tp->gput_seq)) {
4100 		/*
4101 		 * Stop the goodput now, the idea here is
4102 		 * that future measurements with in_probe_rtt
4103 		 * won't register if they are not greater so
4104 		 * we want to get what info (if any) is available
4105 		 * now.
4106 		 */
4107 		rack_do_goodput_measurement(rack->rc_tp, rack,
4108 					    rack->rc_tp->snd_una, __LINE__,
4109 					    RACK_QUALITY_PROBERTT);
4110 	} else if (rack->rc_tp->t_flags & TF_GPUTINPROG) {
4111 		/*
4112 		 * We don't have enough data to make a measurement.
4113 		 * So lets just stop and start here after exiting
4114 		 * probe-rtt. We probably are not interested in
4115 		 * the results anyway.
4116 		 */
4117 		rack->rc_tp->t_flags &= ~TF_GPUTINPROG;
4118 	}
4119 	/*
4120 	 * Measurements through the current snd_max are going
4121 	 * to be limited by the slower pacing rate.
4122 	 *
4123 	 * We need to mark these as app-limited so we
4124 	 * don't collapse the b/w.
4125 	 */
4126 	rsm = tqhash_max(rack->r_ctl.tqh);
4127 	if (rsm && ((rsm->r_flags & RACK_APP_LIMITED) == 0)) {
4128 		if (rack->r_ctl.rc_app_limited_cnt == 0)
4129 			rack->r_ctl.rc_end_appl = rack->r_ctl.rc_first_appl = rsm;
4130 		else {
4131 			/*
4132 			 * Go out to the end app limited and mark
4133 			 * this new one as next and move the end_appl up
4134 			 * to this guy.
4135 			 */
4136 			if (rack->r_ctl.rc_end_appl)
4137 				rack->r_ctl.rc_end_appl->r_nseq_appl = rsm->r_start;
4138 			rack->r_ctl.rc_end_appl = rsm;
4139 		}
4140 		rsm->r_flags |= RACK_APP_LIMITED;
4141 		rack->r_ctl.rc_app_limited_cnt++;
4142 	}
4143 	/*
4144 	 * Now, we need to examine our pacing rate multipliers.
4145 	 * If its under 100%, we need to kick it back up to
4146 	 * 100%. We also don't let it be over our "max" above
4147 	 * the actual rate i.e. 100% + rack_clamp_atexit_prtt.
4148 	 * Note setting clamp_atexit_prtt to 0 has the effect
4149 	 * of setting CA/SS to 100% always at exit (which is
4150 	 * the default behavior).
4151 	 */
4152 	if (rack_probertt_clear_is) {
4153 		rack->rc_gp_incr = 0;
4154 		rack->rc_gp_bwred = 0;
4155 		rack->rc_gp_timely_inc_cnt = 0;
4156 		rack->rc_gp_timely_dec_cnt = 0;
4157 	}
4158 	/* Do we do any clamping at exit? */
4159 	if (rack->rc_highly_buffered && rack_atexit_prtt_hbp) {
4160 		rack->r_ctl.rack_per_of_gp_ca = rack_atexit_prtt_hbp;
4161 		rack->r_ctl.rack_per_of_gp_ss = rack_atexit_prtt_hbp;
4162 	}
4163 	if ((rack->rc_highly_buffered == 0) && rack_atexit_prtt) {
4164 		rack->r_ctl.rack_per_of_gp_ca = rack_atexit_prtt;
4165 		rack->r_ctl.rack_per_of_gp_ss = rack_atexit_prtt;
4166 	}
4167 	/*
4168 	 * Lets set rtt_diff to 0, so that we will get a "boost"
4169 	 * after exiting.
4170 	 */
4171 	rack->r_ctl.rc_rtt_diff = 0;
4172 
4173 	/* Clear all flags so we start fresh */
4174 	rack->rc_tp->t_bytes_acked = 0;
4175 	rack->rc_tp->t_ccv.flags &= ~CCF_ABC_SENTAWND;
4176 	/*
4177 	 * If configured to, set the cwnd and ssthresh to
4178 	 * our targets.
4179 	 */
4180 	if (rack_probe_rtt_sets_cwnd) {
4181 		uint64_t ebdp;
4182 		uint32_t setto;
4183 
4184 		/* Set ssthresh so we get into CA once we hit our target */
4185 		if (rack_probertt_use_min_rtt_exit == 1) {
4186 			/* Set to min rtt */
4187 			rack_set_prtt_target(rack, segsiz,
4188 					     get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt));
4189 		} else if (rack_probertt_use_min_rtt_exit == 2) {
4190 			/* Set to current gp rtt */
4191 			rack_set_prtt_target(rack, segsiz,
4192 					     rack->r_ctl.rc_gp_srtt);
4193 		} else if (rack_probertt_use_min_rtt_exit == 3) {
4194 			/* Set to entry gp rtt */
4195 			rack_set_prtt_target(rack, segsiz,
4196 					     rack->r_ctl.rc_entry_gp_rtt);
4197 		} else {
4198 			uint64_t sum;
4199 			uint32_t setval;
4200 
4201 			sum = rack->r_ctl.rc_entry_gp_rtt;
4202 			sum *= 10;
4203 			sum /= (uint64_t)(max(1, rack->r_ctl.rc_gp_srtt));
4204 			if (sum >= 20) {
4205 				/*
4206 				 * A highly buffered path needs
4207 				 * cwnd space for timely to work.
4208 				 * Lets set things up as if
4209 				 * we are heading back here again.
4210 				 */
4211 				setval = rack->r_ctl.rc_entry_gp_rtt;
4212 			} else if (sum >= 15) {
4213 				/*
4214 				 * Lets take the smaller of the
4215 				 * two since we are just somewhat
4216 				 * buffered.
4217 				 */
4218 				setval = rack->r_ctl.rc_gp_srtt;
4219 				if (setval > rack->r_ctl.rc_entry_gp_rtt)
4220 					setval = rack->r_ctl.rc_entry_gp_rtt;
4221 			} else {
4222 				/*
4223 				 * Here we are not highly buffered
4224 				 * and should pick the min we can to
4225 				 * keep from causing loss.
4226 				 */
4227 				setval = get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt);
4228 			}
4229 			rack_set_prtt_target(rack, segsiz,
4230 					     setval);
4231 		}
4232 		if (rack_probe_rtt_sets_cwnd > 1) {
4233 			/* There is a percentage here to boost */
4234 			ebdp = rack->r_ctl.rc_target_probertt_flight;
4235 			ebdp *= rack_probe_rtt_sets_cwnd;
4236 			ebdp /= 100;
4237 			setto = rack->r_ctl.rc_target_probertt_flight + ebdp;
4238 		} else
4239 			setto = rack->r_ctl.rc_target_probertt_flight;
4240 		rack->rc_tp->snd_cwnd = roundup(setto, segsiz);
4241 		if (rack->rc_tp->snd_cwnd < (segsiz * rack_timely_min_segs)) {
4242 			/* Enforce a min */
4243 			rack->rc_tp->snd_cwnd = segsiz * rack_timely_min_segs;
4244 		}
4245 		/* If we set in the cwnd also set the ssthresh point so we are in CA */
4246 		rack->rc_tp->snd_ssthresh = (rack->rc_tp->snd_cwnd - 1);
4247 	}
4248 	rack_log_rtt_shrinks(rack,  us_cts,
4249 			     get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt),
4250 			     __LINE__, RACK_RTTS_EXITPROBE);
4251 	/* Clear times last so log has all the info */
4252 	rack->r_ctl.rc_probertt_sndmax_atexit = rack->rc_tp->snd_max;
4253 	rack->r_ctl.rc_time_probertt_entered = us_cts;
4254 	rack->r_ctl.rc_time_probertt_starts = rack->r_ctl.rc_lower_rtt_us_cts = us_cts;
4255 	rack->r_ctl.rc_time_of_last_probertt = us_cts;
4256 }
4257 
4258 static void
4259 rack_check_probe_rtt(struct tcp_rack *rack, uint32_t us_cts)
4260 {
4261 	/* Check in on probe-rtt */
4262 
4263 	if (rack->rc_gp_filled == 0) {
4264 		/* We do not do p-rtt unless we have gp measurements */
4265 		return;
4266 	}
4267 	if (rack->in_probe_rtt) {
4268 		uint64_t no_overflow;
4269 		uint32_t endtime, must_stay;
4270 
4271 		if (rack->r_ctl.rc_went_idle_time &&
4272 		    ((us_cts - rack->r_ctl.rc_went_idle_time) > rack_min_probertt_hold)) {
4273 			/*
4274 			 * We went idle during prtt, just exit now.
4275 			 */
4276 			rack_exit_probertt(rack, us_cts);
4277 		} else if (rack_probe_rtt_safety_val &&
4278 		    TSTMP_GT(us_cts, rack->r_ctl.rc_time_probertt_entered) &&
4279 		    ((us_cts - rack->r_ctl.rc_time_probertt_entered) > rack_probe_rtt_safety_val)) {
4280 			/*
4281 			 * Probe RTT safety value triggered!
4282 			 */
4283 			rack_log_rtt_shrinks(rack,  us_cts,
4284 					     get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt),
4285 					     __LINE__, RACK_RTTS_SAFETY);
4286 			rack_exit_probertt(rack, us_cts);
4287 		}
4288 		/* Calculate the max we will wait */
4289 		endtime = rack->r_ctl.rc_time_probertt_entered + (rack->r_ctl.rc_gp_srtt * rack_max_drain_wait);
4290 		if (rack->rc_highly_buffered)
4291 			endtime += (rack->r_ctl.rc_gp_srtt * rack_max_drain_hbp);
4292 		/* Calculate the min we must wait */
4293 		must_stay = rack->r_ctl.rc_time_probertt_entered + (rack->r_ctl.rc_gp_srtt * rack_must_drain);
4294 		if ((ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked) > rack->r_ctl.rc_target_probertt_flight) &&
4295 		    TSTMP_LT(us_cts, endtime)) {
4296 			uint32_t calc;
4297 			/* Do we lower more? */
4298 no_exit:
4299 			if (TSTMP_GT(us_cts, rack->r_ctl.rc_time_probertt_entered))
4300 				calc = us_cts - rack->r_ctl.rc_time_probertt_entered;
4301 			else
4302 				calc = 0;
4303 			calc /= max(rack->r_ctl.rc_gp_srtt, 1);
4304 			if (calc) {
4305 				/* Maybe */
4306 				calc *= rack_per_of_gp_probertt_reduce;
4307 				if (calc > rack_per_of_gp_probertt)
4308 					rack->r_ctl.rack_per_of_gp_probertt = rack_per_of_gp_lowthresh;
4309 				else
4310 					rack->r_ctl.rack_per_of_gp_probertt = rack_per_of_gp_probertt - calc;
4311 				/* Limit it too */
4312 				if (rack->r_ctl.rack_per_of_gp_probertt < rack_per_of_gp_lowthresh)
4313 					rack->r_ctl.rack_per_of_gp_probertt = rack_per_of_gp_lowthresh;
4314 			}
4315 			/* We must reach target or the time set */
4316 			return;
4317 		}
4318 		if (rack->r_ctl.rc_time_probertt_starts == 0) {
4319 			if ((TSTMP_LT(us_cts, must_stay) &&
4320 			     rack->rc_highly_buffered) ||
4321 			     (ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked) >
4322 			      rack->r_ctl.rc_target_probertt_flight)) {
4323 				/* We are not past the must_stay time */
4324 				goto no_exit;
4325 			}
4326 			rack_log_rtt_shrinks(rack,  us_cts,
4327 					     get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt),
4328 					     __LINE__, RACK_RTTS_REACHTARGET);
4329 			rack->r_ctl.rc_time_probertt_starts = us_cts;
4330 			if (rack->r_ctl.rc_time_probertt_starts == 0)
4331 				rack->r_ctl.rc_time_probertt_starts = 1;
4332 			/* Restore back to our rate we want to pace at in prtt */
4333 			rack->r_ctl.rack_per_of_gp_probertt = rack_per_of_gp_probertt;
4334 		}
4335 		/*
4336 		 * Setup our end time, some number of gp_srtts plus 200ms.
4337 		 */
4338 		no_overflow = ((uint64_t)rack->r_ctl.rc_gp_srtt *
4339 			       (uint64_t)rack_probertt_gpsrtt_cnt_mul);
4340 		if (rack_probertt_gpsrtt_cnt_div)
4341 			endtime = (uint32_t)(no_overflow / (uint64_t)rack_probertt_gpsrtt_cnt_div);
4342 		else
4343 			endtime = 0;
4344 		endtime += rack_min_probertt_hold;
4345 		endtime += rack->r_ctl.rc_time_probertt_starts;
4346 		if (TSTMP_GEQ(us_cts,  endtime)) {
4347 			/* yes, exit probertt */
4348 			rack_exit_probertt(rack, us_cts);
4349 		}
4350 
4351 	} else if ((rack->rc_skip_timely == 0) &&
4352 		   (TSTMP_GT(us_cts, rack->r_ctl.rc_lower_rtt_us_cts)) &&
4353 		   ((us_cts - rack->r_ctl.rc_lower_rtt_us_cts) >= rack_time_between_probertt)) {
4354 		/* Go into probertt, its been too long since we went lower */
4355 		rack_enter_probertt(rack, us_cts);
4356 	}
4357 }
4358 
4359 static void
4360 rack_update_multiplier(struct tcp_rack *rack, int32_t timely_says, uint64_t last_bw_est,
4361 		       uint32_t rtt, int32_t rtt_diff)
4362 {
4363 	uint64_t cur_bw, up_bnd, low_bnd, subfr;
4364 	uint32_t losses;
4365 
4366 	if ((rack->rc_gp_dyn_mul == 0) ||
4367 	    (rack->use_fixed_rate) ||
4368 	    (rack->in_probe_rtt) ||
4369 	    (rack->rc_always_pace == 0)) {
4370 		/* No dynamic GP multiplier in play */
4371 		return;
4372 	}
4373 	losses = rack->r_ctl.rc_loss_count - rack->r_ctl.rc_loss_at_start;
4374 	cur_bw = rack_get_bw(rack);
4375 	/* Calculate our up and down range */
4376 	up_bnd = rack->r_ctl.last_gp_comp_bw * (uint64_t)rack_gp_per_bw_mul_up;
4377 	up_bnd /= 100;
4378 	up_bnd += rack->r_ctl.last_gp_comp_bw;
4379 
4380 	subfr = (uint64_t)rack->r_ctl.last_gp_comp_bw * (uint64_t)rack_gp_per_bw_mul_down;
4381 	subfr /= 100;
4382 	low_bnd = rack->r_ctl.last_gp_comp_bw - subfr;
4383 	if ((timely_says == 2) && (rack->r_ctl.rc_no_push_at_mrtt)) {
4384 		/*
4385 		 * This is the case where our RTT is above
4386 		 * the max target and we have been configured
4387 		 * to just do timely no bonus up stuff in that case.
4388 		 *
4389 		 * There are two configurations, set to 1, and we
4390 		 * just do timely if we are over our max. If its
4391 		 * set above 1 then we slam the multipliers down
4392 		 * to 100 and then decrement per timely.
4393 		 */
4394 		rack_log_timely(rack,  timely_says, cur_bw, low_bnd, up_bnd,
4395 				__LINE__, 3);
4396 		if (rack->r_ctl.rc_no_push_at_mrtt > 1)
4397 			rack_validate_multipliers_at_or_below_100(rack);
4398 		rack_decrease_bw_mul(rack, timely_says, rtt, rtt_diff);
4399 	} else if ((timely_says != 0) && (last_bw_est < low_bnd) && !losses) {
4400 		/*
4401 		 * We are decreasing this is a bit complicated this
4402 		 * means we are loosing ground. This could be
4403 		 * because another flow entered and we are competing
4404 		 * for b/w with it. This will push the RTT up which
4405 		 * makes timely unusable unless we want to get shoved
4406 		 * into a corner and just be backed off (the age
4407 		 * old problem with delay based CC).
4408 		 *
4409 		 * On the other hand if it was a route change we
4410 		 * would like to stay somewhat contained and not
4411 		 * blow out the buffers.
4412 		 */
4413 		rack_log_timely(rack,  timely_says, cur_bw, low_bnd, up_bnd,
4414 				__LINE__, 3);
4415 		rack->r_ctl.last_gp_comp_bw = cur_bw;
4416 		if (rack->rc_gp_bwred == 0) {
4417 			/* Go into reduction counting */
4418 			rack->rc_gp_bwred = 1;
4419 			rack->rc_gp_timely_dec_cnt = 0;
4420 		}
4421 		if (rack->rc_gp_timely_dec_cnt < rack_timely_max_push_drop) {
4422 			/*
4423 			 * Push another time with a faster pacing
4424 			 * to try to gain back (we include override to
4425 			 * get a full raise factor).
4426 			 */
4427 			if ((rack->rc_gp_saw_ca && rack->r_ctl.rack_per_of_gp_ca <= rack_down_raise_thresh) ||
4428 			    (rack->rc_gp_saw_ss && rack->r_ctl.rack_per_of_gp_ss <= rack_down_raise_thresh) ||
4429 			    (timely_says == 0) ||
4430 			    (rack_down_raise_thresh == 0)) {
4431 				/*
4432 				 * Do an override up in b/w if we were
4433 				 * below the threshold or if the threshold
4434 				 * is zero we always do the raise.
4435 				 */
4436 				rack_increase_bw_mul(rack, timely_says, cur_bw, last_bw_est, 1);
4437 			} else {
4438 				/* Log it stays the same */
4439 				rack_log_timely(rack,  0, last_bw_est, low_bnd, 0,
4440 						__LINE__, 11);
4441 			}
4442 			rack->rc_gp_timely_dec_cnt++;
4443 			/* We are not incrementing really no-count */
4444 			rack->rc_gp_incr = 0;
4445 			rack->rc_gp_timely_inc_cnt = 0;
4446 		} else {
4447 			/*
4448 			 * Lets just use the RTT
4449 			 * information and give up
4450 			 * pushing.
4451 			 */
4452 			goto use_timely;
4453 		}
4454 	} else if ((timely_says != 2) &&
4455 		    !losses &&
4456 		    (last_bw_est > up_bnd)) {
4457 		/*
4458 		 * We are increasing b/w lets keep going, updating
4459 		 * our b/w and ignoring any timely input, unless
4460 		 * of course we are at our max raise (if there is one).
4461 		 */
4462 
4463 		rack_log_timely(rack,  timely_says, cur_bw, low_bnd, up_bnd,
4464 				__LINE__, 3);
4465 		rack->r_ctl.last_gp_comp_bw = cur_bw;
4466 		if (rack->rc_gp_saw_ss &&
4467 		    rack->r_ctl.rack_per_upper_bound_ss &&
4468 		     (rack->r_ctl.rack_per_of_gp_ss == rack->r_ctl.rack_per_upper_bound_ss)) {
4469 			    /*
4470 			     * In cases where we can't go higher
4471 			     * we should just use timely.
4472 			     */
4473 			    goto use_timely;
4474 		}
4475 		if (rack->rc_gp_saw_ca &&
4476 		    rack->r_ctl.rack_per_upper_bound_ca &&
4477 		    (rack->r_ctl.rack_per_of_gp_ca == rack->r_ctl.rack_per_upper_bound_ca)) {
4478 			    /*
4479 			     * In cases where we can't go higher
4480 			     * we should just use timely.
4481 			     */
4482 			    goto use_timely;
4483 		}
4484 		rack->rc_gp_bwred = 0;
4485 		rack->rc_gp_timely_dec_cnt = 0;
4486 		/* You get a set number of pushes if timely is trying to reduce */
4487 		if ((rack->rc_gp_incr < rack_timely_max_push_rise) || (timely_says == 0)) {
4488 			rack_increase_bw_mul(rack, timely_says, cur_bw, last_bw_est, 0);
4489 		} else {
4490 			/* Log it stays the same */
4491 			rack_log_timely(rack,  0, last_bw_est, up_bnd, 0,
4492 			    __LINE__, 12);
4493 		}
4494 		return;
4495 	} else {
4496 		/*
4497 		 * We are staying between the lower and upper range bounds
4498 		 * so use timely to decide.
4499 		 */
4500 		rack_log_timely(rack,  timely_says, cur_bw, low_bnd, up_bnd,
4501 				__LINE__, 3);
4502 use_timely:
4503 		if (timely_says) {
4504 			rack->rc_gp_incr = 0;
4505 			rack->rc_gp_timely_inc_cnt = 0;
4506 			if ((rack->rc_gp_timely_dec_cnt < rack_timely_max_push_drop) &&
4507 			    !losses &&
4508 			    (last_bw_est < low_bnd)) {
4509 				/* We are loosing ground */
4510 				rack_increase_bw_mul(rack, timely_says, cur_bw, last_bw_est, 0);
4511 				rack->rc_gp_timely_dec_cnt++;
4512 				/* We are not incrementing really no-count */
4513 				rack->rc_gp_incr = 0;
4514 				rack->rc_gp_timely_inc_cnt = 0;
4515 			} else
4516 				rack_decrease_bw_mul(rack, timely_says, rtt, rtt_diff);
4517 		} else {
4518 			rack->rc_gp_bwred = 0;
4519 			rack->rc_gp_timely_dec_cnt = 0;
4520 			rack_increase_bw_mul(rack, timely_says, cur_bw, last_bw_est, 0);
4521 		}
4522 	}
4523 }
4524 
4525 static int32_t
4526 rack_make_timely_judgement(struct tcp_rack *rack, uint32_t rtt, int32_t rtt_diff, uint32_t prev_rtt)
4527 {
4528 	int32_t timely_says;
4529 	uint64_t log_mult, log_rtt_a_diff;
4530 
4531 	log_rtt_a_diff = rtt;
4532 	log_rtt_a_diff <<= 32;
4533 	log_rtt_a_diff |= (uint32_t)rtt_diff;
4534 	if (rtt >= (get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt) *
4535 		    rack_gp_rtt_maxmul)) {
4536 		/* Reduce the b/w multiplier */
4537 		timely_says = 2;
4538 		log_mult = get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt) * rack_gp_rtt_maxmul;
4539 		log_mult <<= 32;
4540 		log_mult |= prev_rtt;
4541 		rack_log_timely(rack,  timely_says, log_mult,
4542 				get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt),
4543 				log_rtt_a_diff, __LINE__, 4);
4544 	} else if (rtt <= (get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt) +
4545 			   ((get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt) * rack_gp_rtt_minmul) /
4546 			    max(rack_gp_rtt_mindiv , 1)))) {
4547 		/* Increase the b/w multiplier */
4548 		log_mult = get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt) +
4549 			((get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt) * rack_gp_rtt_minmul) /
4550 			 max(rack_gp_rtt_mindiv , 1));
4551 		log_mult <<= 32;
4552 		log_mult |= prev_rtt;
4553 		timely_says = 0;
4554 		rack_log_timely(rack,  timely_says, log_mult ,
4555 				get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt),
4556 				log_rtt_a_diff, __LINE__, 5);
4557 	} else {
4558 		/*
4559 		 * Use a gradient to find it the timely gradient
4560 		 * is:
4561 		 * grad = rc_rtt_diff / min_rtt;
4562 		 *
4563 		 * anything below or equal to 0 will be
4564 		 * a increase indication. Anything above
4565 		 * zero is a decrease. Note we take care
4566 		 * of the actual gradient calculation
4567 		 * in the reduction (its not needed for
4568 		 * increase).
4569 		 */
4570 		log_mult = prev_rtt;
4571 		if (rtt_diff <= 0) {
4572 			/*
4573 			 * Rttdiff is less than zero, increase the
4574 			 * b/w multiplier (its 0 or negative)
4575 			 */
4576 			timely_says = 0;
4577 			rack_log_timely(rack,  timely_says, log_mult,
4578 					get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt), log_rtt_a_diff, __LINE__, 6);
4579 		} else {
4580 			/* Reduce the b/w multiplier */
4581 			timely_says = 1;
4582 			rack_log_timely(rack,  timely_says, log_mult,
4583 					get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt), log_rtt_a_diff, __LINE__, 7);
4584 		}
4585 	}
4586 	return (timely_says);
4587 }
4588 
4589 static inline int
4590 rack_in_gp_window(struct tcpcb *tp, struct rack_sendmap *rsm)
4591 {
4592 	if (SEQ_GEQ(rsm->r_start, tp->gput_seq) &&
4593 	    SEQ_LEQ(rsm->r_end, tp->gput_ack)) {
4594 		/**
4595 		 * This covers the case that the
4596 		 * resent is completely inside
4597 		 * the gp range or up to it.
4598 		 *      |----------------|
4599 		 *      |-----| <or>
4600 		 *            |----|
4601 		 *            <or>   |---|
4602 		 */
4603 		return (1);
4604 	} else if (SEQ_LT(rsm->r_start, tp->gput_seq) &&
4605 		   SEQ_GT(rsm->r_end, tp->gput_seq)){
4606 		/**
4607 		 * This covers the case of
4608 		 *      |--------------|
4609 		 *  |-------->|
4610 		 */
4611 		return (1);
4612 	} else if (SEQ_GEQ(rsm->r_start, tp->gput_seq) &&
4613 		   SEQ_LT(rsm->r_start, tp->gput_ack) &&
4614 		   SEQ_GEQ(rsm->r_end, tp->gput_ack)) {
4615 
4616 		/**
4617 		 * This covers the case of
4618 		 *      |--------------|
4619 		 *              |-------->|
4620 		 */
4621 		return (1);
4622 	}
4623 	return (0);
4624 }
4625 
4626 static inline void
4627 rack_mark_in_gp_win(struct tcpcb *tp, struct rack_sendmap *rsm)
4628 {
4629 
4630 	if ((tp->t_flags & TF_GPUTINPROG) == 0)
4631 		return;
4632 	/*
4633 	 * We have a Goodput measurement in progress. Mark
4634 	 * the send if its within the window. If its not
4635 	 * in the window make sure it does not have the mark.
4636 	 */
4637 	if (rack_in_gp_window(tp, rsm))
4638 		rsm->r_flags |= RACK_IN_GP_WIN;
4639 	else
4640 		rsm->r_flags &= ~RACK_IN_GP_WIN;
4641 }
4642 
4643 static inline void
4644 rack_clear_gp_marks(struct tcpcb *tp, struct tcp_rack *rack)
4645 {
4646 	/* A GP measurement is ending, clear all marks on the send map*/
4647 	struct rack_sendmap *rsm = NULL;
4648 
4649 	rsm = tqhash_find(rack->r_ctl.tqh, tp->gput_seq);
4650 	if (rsm == NULL) {
4651 		rsm = tqhash_min(rack->r_ctl.tqh);
4652 	}
4653 	/* Nothing left? */
4654 	while ((rsm != NULL) && (SEQ_GEQ(tp->gput_ack, rsm->r_start))){
4655 		rsm->r_flags &= ~RACK_IN_GP_WIN;
4656 		rsm = tqhash_next(rack->r_ctl.tqh, rsm);
4657 	}
4658 }
4659 
4660 
4661 static inline void
4662 rack_tend_gp_marks(struct tcpcb *tp, struct tcp_rack *rack)
4663 {
4664 	struct rack_sendmap *rsm = NULL;
4665 
4666 	if (tp->snd_una == tp->snd_max) {
4667 		/* Nothing outstanding yet, nothing to do here */
4668 		return;
4669 	}
4670 	if (SEQ_GT(tp->gput_seq, tp->snd_una)) {
4671 		/*
4672 		 * We are measuring ahead of some outstanding
4673 		 * data. We need to walk through up until we get
4674 		 * to gp_seq marking so that no rsm is set incorrectly
4675 		 * with RACK_IN_GP_WIN.
4676 		 */
4677 		rsm = tqhash_min(rack->r_ctl.tqh);
4678 		while (rsm != NULL) {
4679 			rack_mark_in_gp_win(tp, rsm);
4680 			if (SEQ_GEQ(rsm->r_end, tp->gput_seq))
4681 				break;
4682 			rsm = tqhash_next(rack->r_ctl.tqh, rsm);
4683 		}
4684 	}
4685 	if (rsm == NULL) {
4686 		/*
4687 		 * Need to find the GP seq, if rsm is
4688 		 * set we stopped as we hit it.
4689 		 */
4690 		rsm = tqhash_find(rack->r_ctl.tqh, tp->gput_seq);
4691 		if (rsm == NULL)
4692 			return;
4693 		rack_mark_in_gp_win(tp, rsm);
4694 	}
4695 	/*
4696 	 * Now we may need to mark already sent rsm, ahead of
4697 	 * gput_seq in the window since they may have been sent
4698 	 * *before* we started our measurment. The rsm, if non-null
4699 	 * has been marked (note if rsm would have been NULL we would have
4700 	 * returned in the previous block). So we go to the next, and continue
4701 	 * until we run out of entries or we exceed the gp_ack value.
4702 	 */
4703 	rsm = tqhash_next(rack->r_ctl.tqh, rsm);
4704 	while (rsm) {
4705 		rack_mark_in_gp_win(tp, rsm);
4706 		if (SEQ_GT(rsm->r_end, tp->gput_ack))
4707 			break;
4708 		rsm = tqhash_next(rack->r_ctl.tqh, rsm);
4709 	}
4710 }
4711 
4712 static void
4713 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)
4714 {
4715 	if (tcp_bblogging_on(rack->rc_tp)) {
4716 		union tcp_log_stackspecific log;
4717 		struct timeval tv;
4718 
4719 		memset(&log, 0, sizeof(log));
4720 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
4721 		log.u_bbr.flex1 = add_part;
4722 		log.u_bbr.flex2 = sub_part;
4723 		log.u_bbr.flex3 = rack_wma_divisor;
4724 		log.u_bbr.flex4 = srtt;
4725 		log.u_bbr.flex7 = (uint16_t)line;
4726 		log.u_bbr.flex8 = meth;
4727 		log.u_bbr.delRate = rack->r_ctl.gp_bw;
4728 		log.u_bbr.cur_del_rate = meas_bw;
4729 		log.u_bbr.rttProp = utim;
4730 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
4731 		    &rack->rc_inp->inp_socket->so_rcv,
4732 		    &rack->rc_inp->inp_socket->so_snd,
4733 		    BBR_LOG_THRESH_CALC, 0,
4734 		    0, &log, false, &rack->r_ctl.act_rcv_time);
4735 	}
4736 }
4737 
4738 static void
4739 rack_do_goodput_measurement(struct tcpcb *tp, struct tcp_rack *rack,
4740 			    tcp_seq th_ack, int line, uint8_t quality)
4741 {
4742 	uint64_t tim, bytes_ps, stim, utim;
4743 	uint32_t segsiz, bytes, reqbytes, us_cts;
4744 	int32_t gput, new_rtt_diff, timely_says;
4745 	uint64_t  resid_bw, subpart = 0, addpart = 0, srtt;
4746 	int did_add = 0;
4747 
4748 	us_cts = tcp_tv_to_usec(&rack->r_ctl.act_rcv_time);
4749 	segsiz = min(ctf_fixed_maxseg(tp), rack->r_ctl.rc_pace_min_segs);
4750 	if (TSTMP_GEQ(us_cts, tp->gput_ts))
4751 		tim = us_cts - tp->gput_ts;
4752 	else
4753 		tim = 0;
4754 	if (rack->r_ctl.rc_gp_cumack_ts > rack->r_ctl.rc_gp_output_ts)
4755 		stim = rack->r_ctl.rc_gp_cumack_ts - rack->r_ctl.rc_gp_output_ts;
4756 	else
4757 		stim = 0;
4758 	/*
4759 	 * Use the larger of the send time or ack time. This prevents us
4760 	 * from being influenced by ack artifacts to come up with too
4761 	 * high of measurement. Note that since we are spanning over many more
4762 	 * bytes in most of our measurements hopefully that is less likely to
4763 	 * occur.
4764 	 */
4765 	if (tim > stim)
4766 		utim = max(tim, 1);
4767 	else
4768 		utim = max(stim, 1);
4769 	reqbytes = min(rc_init_window(rack), (MIN_GP_WIN * segsiz));
4770 	rack_log_gpset(rack, th_ack, us_cts, rack->r_ctl.rc_gp_cumack_ts, __LINE__, 3, NULL);
4771 	if ((tim == 0) && (stim == 0)) {
4772 		/*
4773 		 * Invalid measurement time, maybe
4774 		 * all on one ack/one send?
4775 		 */
4776 		bytes = 0;
4777 		bytes_ps = 0;
4778 		rack_log_pacing_delay_calc(rack, bytes_ps, reqbytes,
4779 					   0, 0, 0, 10, __LINE__, NULL, quality);
4780 		goto skip_measurement;
4781 	}
4782 	if (rack->r_ctl.rc_gp_lowrtt == 0xffffffff) {
4783 		/* We never made a us_rtt measurement? */
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 	/*
4791 	 * Calculate the maximum possible b/w this connection
4792 	 * could have. We base our calculation on the lowest
4793 	 * rtt we have seen during the measurement and the
4794 	 * largest rwnd the client has given us in that time. This
4795 	 * forms a BDP that is the maximum that we could ever
4796 	 * get to the client. Anything larger is not valid.
4797 	 *
4798 	 * I originally had code here that rejected measurements
4799 	 * where the time was less than 1/2 the latest us_rtt.
4800 	 * But after thinking on that I realized its wrong since
4801 	 * say you had a 150Mbps or even 1Gbps link, and you
4802 	 * were a long way away.. example I am in Europe (100ms rtt)
4803 	 * talking to my 1Gbps link in S.C. Now measuring say 150,000
4804 	 * bytes my time would be 1.2ms, and yet my rtt would say
4805 	 * the measurement was invalid the time was < 50ms. The
4806 	 * same thing is true for 150Mb (8ms of time).
4807 	 *
4808 	 * A better way I realized is to look at what the maximum
4809 	 * the connection could possibly do. This is gated on
4810 	 * the lowest RTT we have seen and the highest rwnd.
4811 	 * We should in theory never exceed that, if we are
4812 	 * then something on the path is storing up packets
4813 	 * and then feeding them all at once to our endpoint
4814 	 * messing up our measurement.
4815 	 */
4816 	rack->r_ctl.last_max_bw = rack->r_ctl.rc_gp_high_rwnd;
4817 	rack->r_ctl.last_max_bw *= HPTS_USEC_IN_SEC;
4818 	rack->r_ctl.last_max_bw /= rack->r_ctl.rc_gp_lowrtt;
4819 	if (SEQ_LT(th_ack, tp->gput_seq)) {
4820 		/* No measurement can be made */
4821 		bytes = 0;
4822 		bytes_ps = 0;
4823 		rack_log_pacing_delay_calc(rack, bytes_ps, reqbytes,
4824 					   0, 0, 0, 10, __LINE__, NULL, quality);
4825 		goto skip_measurement;
4826 	} else
4827 		bytes = (th_ack - tp->gput_seq);
4828 	bytes_ps = (uint64_t)bytes;
4829 	/*
4830 	 * Don't measure a b/w for pacing unless we have gotten at least
4831 	 * an initial windows worth of data in this measurement interval.
4832 	 *
4833 	 * Small numbers of bytes get badly influenced by delayed ack and
4834 	 * other artifacts. Note we take the initial window or our
4835 	 * defined minimum GP (defaulting to 10 which hopefully is the
4836 	 * IW).
4837 	 */
4838 	if (rack->rc_gp_filled == 0) {
4839 		/*
4840 		 * The initial estimate is special. We
4841 		 * have blasted out an IW worth of packets
4842 		 * without a real valid ack ts results. We
4843 		 * then setup the app_limited_needs_set flag,
4844 		 * this should get the first ack in (probably 2
4845 		 * MSS worth) to be recorded as the timestamp.
4846 		 * We thus allow a smaller number of bytes i.e.
4847 		 * IW - 2MSS.
4848 		 */
4849 		reqbytes -= (2 * segsiz);
4850 		/* Also lets fill previous for our first measurement to be neutral */
4851 		rack->r_ctl.rc_prev_gp_srtt = rack->r_ctl.rc_gp_srtt;
4852 	}
4853 	if ((bytes_ps < reqbytes) || rack->app_limited_needs_set) {
4854 		rack_log_pacing_delay_calc(rack, bytes_ps, reqbytes,
4855 					   rack->r_ctl.rc_app_limited_cnt,
4856 					   0, 0, 10, __LINE__, NULL, quality);
4857 		goto skip_measurement;
4858 	}
4859 	/*
4860 	 * We now need to calculate the Timely like status so
4861 	 * we can update (possibly) the b/w multipliers.
4862 	 */
4863 	new_rtt_diff = (int32_t)rack->r_ctl.rc_gp_srtt - (int32_t)rack->r_ctl.rc_prev_gp_srtt;
4864 	if (rack->rc_gp_filled == 0) {
4865 		/* No previous reading */
4866 		rack->r_ctl.rc_rtt_diff = new_rtt_diff;
4867 	} else {
4868 		if (rack->measure_saw_probe_rtt == 0) {
4869 			/*
4870 			 * We don't want a probertt to be counted
4871 			 * since it will be negative incorrectly. We
4872 			 * expect to be reducing the RTT when we
4873 			 * pace at a slower rate.
4874 			 */
4875 			rack->r_ctl.rc_rtt_diff -= (rack->r_ctl.rc_rtt_diff / 8);
4876 			rack->r_ctl.rc_rtt_diff += (new_rtt_diff / 8);
4877 		}
4878 	}
4879 	timely_says = rack_make_timely_judgement(rack,
4880 	    rack->r_ctl.rc_gp_srtt,
4881 	    rack->r_ctl.rc_rtt_diff,
4882 	    rack->r_ctl.rc_prev_gp_srtt
4883 	);
4884 	bytes_ps *= HPTS_USEC_IN_SEC;
4885 	bytes_ps /= utim;
4886 	if (bytes_ps > rack->r_ctl.last_max_bw) {
4887 		/*
4888 		 * Something is on path playing
4889 		 * since this b/w is not possible based
4890 		 * on our BDP (highest rwnd and lowest rtt
4891 		 * we saw in the measurement window).
4892 		 *
4893 		 * Another option here would be to
4894 		 * instead skip the measurement.
4895 		 */
4896 		rack_log_pacing_delay_calc(rack, bytes, reqbytes,
4897 					   bytes_ps, rack->r_ctl.last_max_bw, 0,
4898 					   11, __LINE__, NULL, quality);
4899 		bytes_ps = rack->r_ctl.last_max_bw;
4900 	}
4901 	/* We store gp for b/w in bytes per second */
4902 	if (rack->rc_gp_filled == 0) {
4903 		/* Initial measurement */
4904 		if (bytes_ps) {
4905 			rack->r_ctl.gp_bw = bytes_ps;
4906 			rack->rc_gp_filled = 1;
4907 			rack->r_ctl.num_measurements = 1;
4908 			rack_set_pace_segments(rack->rc_tp, rack, __LINE__, NULL);
4909 		} else {
4910 			rack_log_pacing_delay_calc(rack, bytes_ps, reqbytes,
4911 						   rack->r_ctl.rc_app_limited_cnt,
4912 						   0, 0, 10, __LINE__, NULL, quality);
4913 		}
4914 		if (tcp_in_hpts(rack->rc_tp) &&
4915 		    (rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT)) {
4916 			/*
4917 			 * Ok we can't trust the pacer in this case
4918 			 * where we transition from un-paced to paced.
4919 			 * Or for that matter when the burst mitigation
4920 			 * was making a wild guess and got it wrong.
4921 			 * Stop the pacer and clear up all the aggregate
4922 			 * delays etc.
4923 			 */
4924 			tcp_hpts_remove(rack->rc_tp);
4925 			rack->r_ctl.rc_hpts_flags = 0;
4926 			rack->r_ctl.rc_last_output_to = 0;
4927 		}
4928 		did_add = 2;
4929 	} else if (rack->r_ctl.num_measurements < RACK_REQ_AVG) {
4930 		/* Still a small number run an average */
4931 		rack->r_ctl.gp_bw += bytes_ps;
4932 		addpart = rack->r_ctl.num_measurements;
4933 		rack->r_ctl.num_measurements++;
4934 		if (rack->r_ctl.num_measurements >= RACK_REQ_AVG) {
4935 			/* We have collected enough to move forward */
4936 			rack->r_ctl.gp_bw /= (uint64_t)rack->r_ctl.num_measurements;
4937 		}
4938 		rack_set_pace_segments(tp, rack, __LINE__, NULL);
4939 		did_add = 3;
4940 	} else {
4941 		/*
4942 		 * We want to take 1/wma of the goodput and add in to 7/8th
4943 		 * of the old value weighted by the srtt. So if your measurement
4944 		 * period is say 2 SRTT's long you would get 1/4 as the
4945 		 * value, if it was like 1/2 SRTT then you would get 1/16th.
4946 		 *
4947 		 * But we must be careful not to take too much i.e. if the
4948 		 * srtt is say 20ms and the measurement is taken over
4949 		 * 400ms our weight would be 400/20 i.e. 20. On the
4950 		 * other hand if we get a measurement over 1ms with a
4951 		 * 10ms rtt we only want to take a much smaller portion.
4952 		 */
4953 		uint8_t meth;
4954 
4955 		if (rack->r_ctl.num_measurements < 0xff) {
4956 			rack->r_ctl.num_measurements++;
4957 		}
4958 		srtt = (uint64_t)tp->t_srtt;
4959 		if (srtt == 0) {
4960 			/*
4961 			 * Strange why did t_srtt go back to zero?
4962 			 */
4963 			if (rack->r_ctl.rc_rack_min_rtt)
4964 				srtt = rack->r_ctl.rc_rack_min_rtt;
4965 			else
4966 				srtt = HPTS_USEC_IN_MSEC;
4967 		}
4968 		/*
4969 		 * XXXrrs: Note for reviewers, in playing with
4970 		 * dynamic pacing I discovered this GP calculation
4971 		 * as done originally leads to some undesired results.
4972 		 * Basically you can get longer measurements contributing
4973 		 * too much to the WMA. Thus I changed it if you are doing
4974 		 * dynamic adjustments to only do the aportioned adjustment
4975 		 * if we have a very small (time wise) measurement. Longer
4976 		 * measurements just get there weight (defaulting to 1/8)
4977 		 * add to the WMA. We may want to think about changing
4978 		 * this to always do that for both sides i.e. dynamic
4979 		 * and non-dynamic... but considering lots of folks
4980 		 * were playing with this I did not want to change the
4981 		 * calculation per.se. without your thoughts.. Lawerence?
4982 		 * Peter??
4983 		 */
4984 		if (rack->rc_gp_dyn_mul == 0) {
4985 			subpart = rack->r_ctl.gp_bw * utim;
4986 			subpart /= (srtt * 8);
4987 			if (subpart < (rack->r_ctl.gp_bw / 2)) {
4988 				/*
4989 				 * The b/w update takes no more
4990 				 * away then 1/2 our running total
4991 				 * so factor it in.
4992 				 */
4993 				addpart = bytes_ps * utim;
4994 				addpart /= (srtt * 8);
4995 				meth = 1;
4996 			} else {
4997 				/*
4998 				 * Don't allow a single measurement
4999 				 * to account for more than 1/2 of the
5000 				 * WMA. This could happen on a retransmission
5001 				 * where utim becomes huge compared to
5002 				 * srtt (multiple retransmissions when using
5003 				 * the sending rate which factors in all the
5004 				 * transmissions from the first one).
5005 				 */
5006 				subpart = rack->r_ctl.gp_bw / 2;
5007 				addpart = bytes_ps / 2;
5008 				meth = 2;
5009 			}
5010 			rack_log_gp_calc(rack, addpart, subpart, srtt, bytes_ps, utim, meth, __LINE__);
5011 			resid_bw = rack->r_ctl.gp_bw - subpart;
5012 			rack->r_ctl.gp_bw = resid_bw + addpart;
5013 			did_add = 1;
5014 		} else {
5015 			if ((utim / srtt) <= 1) {
5016 				/*
5017 				 * The b/w update was over a small period
5018 				 * of time. The idea here is to prevent a small
5019 				 * measurement time period from counting
5020 				 * too much. So we scale it based on the
5021 				 * time so it attributes less than 1/rack_wma_divisor
5022 				 * of its measurement.
5023 				 */
5024 				subpart = rack->r_ctl.gp_bw * utim;
5025 				subpart /= (srtt * rack_wma_divisor);
5026 				addpart = bytes_ps * utim;
5027 				addpart /= (srtt * rack_wma_divisor);
5028 				meth = 3;
5029 			} else {
5030 				/*
5031 				 * The scaled measurement was long
5032 				 * enough so lets just add in the
5033 				 * portion of the measurement i.e. 1/rack_wma_divisor
5034 				 */
5035 				subpart = rack->r_ctl.gp_bw / rack_wma_divisor;
5036 				addpart = bytes_ps / rack_wma_divisor;
5037 				meth = 4;
5038 			}
5039 			if ((rack->measure_saw_probe_rtt == 0) ||
5040 		            (bytes_ps > rack->r_ctl.gp_bw)) {
5041 				/*
5042 				 * For probe-rtt we only add it in
5043 				 * if its larger, all others we just
5044 				 * add in.
5045 				 */
5046 				did_add = 1;
5047 				rack_log_gp_calc(rack, addpart, subpart, srtt, bytes_ps, utim, meth, __LINE__);
5048 				resid_bw = rack->r_ctl.gp_bw - subpart;
5049 				rack->r_ctl.gp_bw = resid_bw + addpart;
5050 			}
5051 		}
5052 		rack_set_pace_segments(tp, rack, __LINE__, NULL);
5053 	}
5054 	/*
5055 	 * We only watch the growth of the GP during the initial startup
5056 	 * or first-slowstart that ensues. If we ever needed to watch
5057 	 * growth of gp outside of that period all we need to do is
5058 	 * remove the first clause of this if (rc_initial_ss_comp).
5059 	 */
5060 	if ((rack->rc_initial_ss_comp == 0) &&
5061 	    (rack->r_ctl.num_measurements >= RACK_REQ_AVG)) {
5062 		uint64_t gp_est;
5063 
5064 		gp_est = bytes_ps;
5065 		if (tcp_bblogging_on(rack->rc_tp)) {
5066 			union tcp_log_stackspecific log;
5067 			struct timeval tv;
5068 
5069 			memset(&log, 0, sizeof(log));
5070 			log.u_bbr.timeStamp = tcp_get_usecs(&tv);
5071 			log.u_bbr.flex1 = rack->r_ctl.current_round;
5072 			log.u_bbr.flex2 = rack->r_ctl.last_rnd_of_gp_rise;
5073 			log.u_bbr.delRate = gp_est;
5074 			log.u_bbr.cur_del_rate = rack->r_ctl.last_gpest;
5075 			log.u_bbr.flex8 = 41;
5076 			(void)tcp_log_event(tp, NULL, NULL, NULL, BBR_LOG_CWND, 0,
5077 					    0, &log, false, NULL, __func__, __LINE__,&tv);
5078 		}
5079 		if ((rack->r_ctl.num_measurements == RACK_REQ_AVG) ||
5080 		    (rack->r_ctl.last_gpest == 0)) {
5081 			/*
5082 			 * The round we get our measurement averaging going
5083 			 * is the base round so it always is the source point
5084 			 * for when we had our first increment. From there on
5085 			 * we only record the round that had a rise.
5086 			 */
5087 			rack->r_ctl.last_rnd_of_gp_rise = rack->r_ctl.current_round;
5088 			rack->r_ctl.last_gpest = rack->r_ctl.gp_bw;
5089 		} else if (gp_est >= rack->r_ctl.last_gpest) {
5090 			/*
5091 			 * Test to see if its gone up enough
5092 			 * to set the round count up to now. Note
5093 			 * that on the seeding of the 4th measurement we
5094 			 */
5095 			gp_est *= 1000;
5096 			gp_est /= rack->r_ctl.last_gpest;
5097 			if ((uint32_t)gp_est > rack->r_ctl.gp_gain_req) {
5098 				/*
5099 				 * We went up enough to record the round.
5100 				 */
5101 				if (tcp_bblogging_on(rack->rc_tp)) {
5102 					union tcp_log_stackspecific log;
5103 					struct timeval tv;
5104 
5105 					memset(&log, 0, sizeof(log));
5106 					log.u_bbr.timeStamp = tcp_get_usecs(&tv);
5107 					log.u_bbr.flex1 = rack->r_ctl.current_round;
5108 					log.u_bbr.flex2 = (uint32_t)gp_est;
5109 					log.u_bbr.flex3 = rack->r_ctl.gp_gain_req;
5110 					log.u_bbr.delRate = gp_est;
5111 					log.u_bbr.cur_del_rate = rack->r_ctl.last_gpest;
5112 					log.u_bbr.flex8 = 42;
5113 					(void)tcp_log_event(tp, NULL, NULL, NULL, BBR_LOG_CWND, 0,
5114 							    0, &log, false, NULL, __func__, __LINE__,&tv);
5115 				}
5116 				rack->r_ctl.last_rnd_of_gp_rise = rack->r_ctl.current_round;
5117 				if (rack->r_ctl.use_gp_not_last == 1)
5118 					rack->r_ctl.last_gpest = rack->r_ctl.gp_bw;
5119 				else
5120 					rack->r_ctl.last_gpest = bytes_ps;
5121 			}
5122 		}
5123 	}
5124 	if ((rack->gp_ready == 0) &&
5125 	    (rack->r_ctl.num_measurements >= rack->r_ctl.req_measurements)) {
5126 		/* We have enough measurements now */
5127 		rack->gp_ready = 1;
5128 		if (rack->dgp_on ||
5129 		    rack->rack_hibeta)
5130 			rack_set_cc_pacing(rack);
5131 		if (rack->defer_options)
5132 			rack_apply_deferred_options(rack);
5133 	}
5134 	rack_log_pacing_delay_calc(rack, subpart, addpart, bytes_ps, stim,
5135 				   rack_get_bw(rack), 22, did_add, NULL, quality);
5136 	/* We do not update any multipliers if we are in or have seen a probe-rtt */
5137 
5138 	if ((rack->measure_saw_probe_rtt == 0) &&
5139 	    rack->rc_gp_rtt_set) {
5140 		if (rack->rc_skip_timely == 0) {
5141 			rack_update_multiplier(rack, timely_says, bytes_ps,
5142 					       rack->r_ctl.rc_gp_srtt,
5143 					       rack->r_ctl.rc_rtt_diff);
5144 		}
5145 	}
5146 	rack_log_pacing_delay_calc(rack, bytes, tim, bytes_ps, stim,
5147 				   rack_get_bw(rack), 3, line, NULL, quality);
5148 	rack_log_pacing_delay_calc(rack,
5149 				   bytes, /* flex2 */
5150 				   tim, /* flex1 */
5151 				   bytes_ps, /* bw_inuse */
5152 				   rack->r_ctl.gp_bw, /* delRate */
5153 				   rack_get_lt_bw(rack), /* rttProp */
5154 				   20, line, NULL, 0);
5155 	/* reset the gp srtt and setup the new prev */
5156 	rack->r_ctl.rc_prev_gp_srtt = rack->r_ctl.rc_gp_srtt;
5157 	/* Record the lost count for the next measurement */
5158 	rack->r_ctl.rc_loss_at_start = rack->r_ctl.rc_loss_count;
5159 skip_measurement:
5160 	/*
5161 	 * We restart our diffs based on the gpsrtt in the
5162 	 * measurement window.
5163 	 */
5164 	rack->rc_gp_rtt_set = 0;
5165 	rack->rc_gp_saw_rec = 0;
5166 	rack->rc_gp_saw_ca = 0;
5167 	rack->rc_gp_saw_ss = 0;
5168 	rack->rc_dragged_bottom = 0;
5169 	if (quality == RACK_QUALITY_HIGH) {
5170 		/*
5171 		 * Gput in the stats world is in kbps where bytes_ps is
5172 		 * bytes per second so we do ((x * 8)/ 1000).
5173 		 */
5174 		gput = (int32_t)((bytes_ps << 3) / (uint64_t)1000);
5175 #ifdef STATS
5176 		stats_voi_update_abs_u32(tp->t_stats, VOI_TCP_GPUT,
5177 					 gput);
5178 		/*
5179 		 * XXXLAS: This is a temporary hack, and should be
5180 		 * chained off VOI_TCP_GPUT when stats(9) grows an
5181 		 * API to deal with chained VOIs.
5182 		 */
5183 		if (tp->t_stats_gput_prev > 0)
5184 			stats_voi_update_abs_s32(tp->t_stats,
5185 						 VOI_TCP_GPUT_ND,
5186 						 ((gput - tp->t_stats_gput_prev) * 100) /
5187 						 tp->t_stats_gput_prev);
5188 #endif
5189 		tp->t_stats_gput_prev = gput;
5190 	}
5191 	tp->t_flags &= ~TF_GPUTINPROG;
5192 	/*
5193 	 * Now are we app limited now and there is space from where we
5194 	 * were to where we want to go?
5195 	 *
5196 	 * We don't do the other case i.e. non-applimited here since
5197 	 * the next send will trigger us picking up the missing data.
5198 	 */
5199 	if (rack->r_ctl.rc_first_appl &&
5200 	    TCPS_HAVEESTABLISHED(tp->t_state) &&
5201 	    rack->r_ctl.rc_app_limited_cnt &&
5202 	    (SEQ_GT(rack->r_ctl.rc_first_appl->r_start, th_ack)) &&
5203 	    ((rack->r_ctl.rc_first_appl->r_end - th_ack) >
5204 	     max(rc_init_window(rack), (MIN_GP_WIN * segsiz)))) {
5205 		/*
5206 		 * Yep there is enough outstanding to make a measurement here.
5207 		 */
5208 		struct rack_sendmap *rsm;
5209 
5210 		rack->r_ctl.rc_gp_lowrtt = 0xffffffff;
5211 		rack->r_ctl.rc_gp_high_rwnd = rack->rc_tp->snd_wnd;
5212 		tp->gput_ts = tcp_tv_to_usec(&rack->r_ctl.act_rcv_time);
5213 		rack->app_limited_needs_set = 0;
5214 		tp->gput_seq = th_ack;
5215 		if (rack->in_probe_rtt)
5216 			rack->measure_saw_probe_rtt = 1;
5217 		else if ((rack->measure_saw_probe_rtt) &&
5218 			 (SEQ_GEQ(tp->gput_seq, rack->r_ctl.rc_probertt_sndmax_atexit)))
5219 			rack->measure_saw_probe_rtt = 0;
5220 		if ((rack->r_ctl.rc_first_appl->r_end - th_ack) >= rack_get_measure_window(tp, rack)) {
5221 			/* There is a full window to gain info from */
5222 			tp->gput_ack = tp->gput_seq + rack_get_measure_window(tp, rack);
5223 		} else {
5224 			/* We can only measure up to the applimited point */
5225 			tp->gput_ack = tp->gput_seq + (rack->r_ctl.rc_first_appl->r_end - th_ack);
5226 			if ((tp->gput_ack - tp->gput_seq) < (MIN_GP_WIN * segsiz)) {
5227 				/*
5228 				 * We don't have enough to make a measurement.
5229 				 */
5230 				tp->t_flags &= ~TF_GPUTINPROG;
5231 				rack_log_pacing_delay_calc(rack, tp->gput_ack, tp->gput_seq,
5232 							   0, 0, 0, 6, __LINE__, NULL, quality);
5233 				return;
5234 			}
5235 		}
5236 		if (tp->t_state >= TCPS_FIN_WAIT_1) {
5237 			/*
5238 			 * We will get no more data into the SB
5239 			 * this means we need to have the data available
5240 			 * before we start a measurement.
5241 			 */
5242 			if (sbavail(&tptosocket(tp)->so_snd) < (tp->gput_ack - tp->gput_seq)) {
5243 				/* Nope not enough data. */
5244 				return;
5245 			}
5246 		}
5247 		tp->t_flags |= TF_GPUTINPROG;
5248 		/*
5249 		 * Now we need to find the timestamp of the send at tp->gput_seq
5250 		 * for the send based measurement.
5251 		 */
5252 		rack->r_ctl.rc_gp_cumack_ts = 0;
5253 		rsm = tqhash_find(rack->r_ctl.tqh, tp->gput_seq);
5254 		if (rsm) {
5255 			/* Ok send-based limit is set */
5256 			if (SEQ_LT(rsm->r_start, tp->gput_seq)) {
5257 				/*
5258 				 * Move back to include the earlier part
5259 				 * so our ack time lines up right (this may
5260 				 * make an overlapping measurement but thats
5261 				 * ok).
5262 				 */
5263 				tp->gput_seq = rsm->r_start;
5264 			}
5265 			if (rsm->r_flags & RACK_ACKED) {
5266 				struct rack_sendmap *nrsm;
5267 
5268 				tp->gput_ts = (uint32_t)rsm->r_ack_arrival;
5269 				tp->gput_seq = rsm->r_end;
5270 				nrsm = tqhash_next(rack->r_ctl.tqh, rsm);
5271 				if (nrsm)
5272 					rsm = nrsm;
5273 				else {
5274 					rack->app_limited_needs_set = 1;
5275 				}
5276 			} else
5277 				rack->app_limited_needs_set = 1;
5278 			/* We always go from the first send */
5279 			rack->r_ctl.rc_gp_output_ts = rsm->r_tim_lastsent[0];
5280 		} else {
5281 			/*
5282 			 * If we don't find the rsm due to some
5283 			 * send-limit set the current time, which
5284 			 * basically disables the send-limit.
5285 			 */
5286 			struct timeval tv;
5287 
5288 			microuptime(&tv);
5289 			rack->r_ctl.rc_gp_output_ts = rack_to_usec_ts(&tv);
5290 		}
5291 		rack_tend_gp_marks(tp, rack);
5292 		rack_log_pacing_delay_calc(rack,
5293 					   tp->gput_seq,
5294 					   tp->gput_ack,
5295 					   (uintptr_t)rsm,
5296 					   tp->gput_ts,
5297 					   (((uint64_t)rack->r_ctl.rc_app_limited_cnt << 32) | (uint64_t)rack->r_ctl.rc_gp_output_ts),
5298 					   9,
5299 					   __LINE__, rsm, quality);
5300 		rack_log_gpset(rack, tp->gput_ack, 0, 0, __LINE__, 1, NULL);
5301 	} else {
5302 		/*
5303 		 * To make sure proper timestamp merging occurs, we need to clear
5304 		 * all GP marks if we don't start a measurement.
5305 		 */
5306 		rack_clear_gp_marks(tp, rack);
5307 	}
5308 }
5309 
5310 /*
5311  * CC wrapper hook functions
5312  */
5313 static void
5314 rack_ack_received(struct tcpcb *tp, struct tcp_rack *rack, uint32_t th_ack, uint16_t nsegs,
5315     uint16_t type, int32_t post_recovery)
5316 {
5317 	uint32_t prior_cwnd, acked;
5318 	struct tcp_log_buffer *lgb = NULL;
5319 	uint8_t labc_to_use, quality;
5320 
5321 	INP_WLOCK_ASSERT(tptoinpcb(tp));
5322 	tp->t_ccv.nsegs = nsegs;
5323 	acked = tp->t_ccv.bytes_this_ack = (th_ack - tp->snd_una);
5324 	if ((post_recovery) && (rack->r_ctl.rc_early_recovery_segs)) {
5325 		uint32_t max;
5326 
5327 		max = rack->r_ctl.rc_early_recovery_segs * ctf_fixed_maxseg(tp);
5328 		if (tp->t_ccv.bytes_this_ack > max) {
5329 			tp->t_ccv.bytes_this_ack = max;
5330 		}
5331 	}
5332 #ifdef STATS
5333 	stats_voi_update_abs_s32(tp->t_stats, VOI_TCP_CALCFRWINDIFF,
5334 	    ((int32_t)rack->r_ctl.cwnd_to_use) - tp->snd_wnd);
5335 #endif
5336 	if ((th_ack == tp->snd_max) && rack->lt_bw_up) {
5337 		/*
5338 		 * We will ack all the data, time to end any
5339 		 * lt_bw_up we have running until something
5340 		 * new is sent. Note we need to use the actual
5341 		 * ack_rcv_time which with pacing may be different.
5342 		 */
5343 		uint64_t tmark;
5344 
5345 		rack->r_ctl.lt_bw_bytes += (tp->snd_max - rack->r_ctl.lt_seq);
5346 		rack->r_ctl.lt_seq = tp->snd_max;
5347 		tmark = tcp_tv_to_lusec(&rack->r_ctl.act_rcv_time);
5348 		if (tmark >= rack->r_ctl.lt_timemark) {
5349 			rack->r_ctl.lt_bw_time += (tmark - rack->r_ctl.lt_timemark);
5350 		}
5351 		rack->r_ctl.lt_timemark = tmark;
5352 		rack->lt_bw_up = 0;
5353 	}
5354 	quality = RACK_QUALITY_NONE;
5355 	if ((tp->t_flags & TF_GPUTINPROG) &&
5356 	    rack_enough_for_measurement(tp, rack, th_ack, &quality)) {
5357 		/* Measure the Goodput */
5358 		rack_do_goodput_measurement(tp, rack, th_ack, __LINE__, quality);
5359 	}
5360 	/* Which way our we limited, if not cwnd limited no advance in CA */
5361 	if (tp->snd_cwnd <= tp->snd_wnd)
5362 		tp->t_ccv.flags |= CCF_CWND_LIMITED;
5363 	else
5364 		tp->t_ccv.flags &= ~CCF_CWND_LIMITED;
5365 	if (tp->snd_cwnd > tp->snd_ssthresh) {
5366 		tp->t_bytes_acked += min(tp->t_ccv.bytes_this_ack,
5367 			 nsegs * V_tcp_abc_l_var * ctf_fixed_maxseg(tp));
5368 		/* For the setting of a window past use the actual scwnd we are using */
5369 		if (tp->t_bytes_acked >= rack->r_ctl.cwnd_to_use) {
5370 			tp->t_bytes_acked -= rack->r_ctl.cwnd_to_use;
5371 			tp->t_ccv.flags |= CCF_ABC_SENTAWND;
5372 		}
5373 	} else {
5374 		tp->t_ccv.flags &= ~CCF_ABC_SENTAWND;
5375 		tp->t_bytes_acked = 0;
5376 	}
5377 	prior_cwnd = tp->snd_cwnd;
5378 	if ((post_recovery == 0) || (rack_max_abc_post_recovery == 0) || rack->r_use_labc_for_rec ||
5379 	    (rack_client_low_buf && rack->client_bufferlvl &&
5380 	    (rack->client_bufferlvl < rack_client_low_buf)))
5381 		labc_to_use = rack->rc_labc;
5382 	else
5383 		labc_to_use = rack_max_abc_post_recovery;
5384 	if (rack_verbose_logging && tcp_bblogging_on(rack->rc_tp)) {
5385 		union tcp_log_stackspecific log;
5386 		struct timeval tv;
5387 
5388 		memset(&log, 0, sizeof(log));
5389 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
5390 		log.u_bbr.flex1 = th_ack;
5391 		log.u_bbr.flex2 = tp->t_ccv.flags;
5392 		log.u_bbr.flex3 = tp->t_ccv.bytes_this_ack;
5393 		log.u_bbr.flex4 = tp->t_ccv.nsegs;
5394 		log.u_bbr.flex5 = labc_to_use;
5395 		log.u_bbr.flex6 = prior_cwnd;
5396 		log.u_bbr.flex7 = V_tcp_do_newsack;
5397 		log.u_bbr.flex8 = 1;
5398 		lgb = tcp_log_event(tp, NULL, NULL, NULL, BBR_LOG_CWND, 0,
5399 				     0, &log, false, NULL, __func__, __LINE__,&tv);
5400 	}
5401 	if (CC_ALGO(tp)->ack_received != NULL) {
5402 		/* XXXLAS: Find a way to live without this */
5403 		tp->t_ccv.curack = th_ack;
5404 		tp->t_ccv.labc = labc_to_use;
5405 		tp->t_ccv.flags |= CCF_USE_LOCAL_ABC;
5406 		CC_ALGO(tp)->ack_received(&tp->t_ccv, type);
5407 	}
5408 	if (lgb) {
5409 		lgb->tlb_stackinfo.u_bbr.flex6 = tp->snd_cwnd;
5410 	}
5411 	if (rack->r_must_retran) {
5412 		if (SEQ_GEQ(th_ack, rack->r_ctl.rc_snd_max_at_rto)) {
5413 			/*
5414 			 * We now are beyond the rxt point so lets disable
5415 			 * the flag.
5416 			 */
5417 			rack->r_ctl.rc_out_at_rto = 0;
5418 			rack->r_must_retran = 0;
5419 		} else if ((prior_cwnd + ctf_fixed_maxseg(tp)) <= tp->snd_cwnd) {
5420 			/*
5421 			 * Only decrement the rc_out_at_rto if the cwnd advances
5422 			 * at least a whole segment. Otherwise next time the peer
5423 			 * acks, we won't be able to send this generaly happens
5424 			 * when we are in Congestion Avoidance.
5425 			 */
5426 			if (acked <= rack->r_ctl.rc_out_at_rto){
5427 				rack->r_ctl.rc_out_at_rto -= acked;
5428 			} else {
5429 				rack->r_ctl.rc_out_at_rto = 0;
5430 			}
5431 		}
5432 	}
5433 #ifdef STATS
5434 	stats_voi_update_abs_ulong(tp->t_stats, VOI_TCP_LCWIN, rack->r_ctl.cwnd_to_use);
5435 #endif
5436 	if (rack->r_ctl.rc_rack_largest_cwnd < rack->r_ctl.cwnd_to_use) {
5437 		rack->r_ctl.rc_rack_largest_cwnd = rack->r_ctl.cwnd_to_use;
5438 	}
5439 	if ((rack->rc_initial_ss_comp == 0) &&
5440 	    (tp->snd_cwnd >= tp->snd_ssthresh)) {
5441 		/*
5442 		 * The cwnd has grown beyond ssthresh we have
5443 		 * entered ca and completed our first Slowstart.
5444 		 */
5445 		rack->rc_initial_ss_comp = 1;
5446 	}
5447 }
5448 
5449 static void
5450 tcp_rack_partialack(struct tcpcb *tp)
5451 {
5452 	struct tcp_rack *rack;
5453 
5454 	rack = (struct tcp_rack *)tp->t_fb_ptr;
5455 	INP_WLOCK_ASSERT(tptoinpcb(tp));
5456 	/*
5457 	 * If we are doing PRR and have enough
5458 	 * room to send <or> we are pacing and prr
5459 	 * is disabled we will want to see if we
5460 	 * can send data (by setting r_wanted_output to
5461 	 * true).
5462 	 */
5463 	if ((rack->r_ctl.rc_prr_sndcnt > 0) ||
5464 	    rack->rack_no_prr)
5465 		rack->r_wanted_output = 1;
5466 }
5467 
5468 static void
5469 rack_exit_recovery(struct tcpcb *tp, struct tcp_rack *rack, int how)
5470 {
5471 	/*
5472 	 * Now exit recovery.
5473 	 */
5474 	EXIT_RECOVERY(tp->t_flags);
5475 }
5476 
5477 static void
5478 rack_post_recovery(struct tcpcb *tp, uint32_t th_ack)
5479 {
5480 	struct tcp_rack *rack;
5481 	uint32_t orig_cwnd;
5482 
5483 	orig_cwnd = tp->snd_cwnd;
5484 	INP_WLOCK_ASSERT(tptoinpcb(tp));
5485 	rack = (struct tcp_rack *)tp->t_fb_ptr;
5486 	/* only alert CC if we alerted when we entered */
5487 	if (CC_ALGO(tp)->post_recovery != NULL) {
5488 		tp->t_ccv.curack = th_ack;
5489 		CC_ALGO(tp)->post_recovery(&tp->t_ccv);
5490 		if (tp->snd_cwnd < tp->snd_ssthresh) {
5491 			/*
5492 			 * Rack has burst control and pacing
5493 			 * so lets not set this any lower than
5494 			 * snd_ssthresh per RFC-6582 (option 2).
5495 			 */
5496 			tp->snd_cwnd = tp->snd_ssthresh;
5497 		}
5498 	}
5499 	if (rack_verbose_logging && tcp_bblogging_on(rack->rc_tp)) {
5500 		union tcp_log_stackspecific log;
5501 		struct timeval tv;
5502 
5503 		memset(&log, 0, sizeof(log));
5504 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
5505 		log.u_bbr.flex1 = th_ack;
5506 		log.u_bbr.flex2 = tp->t_ccv.flags;
5507 		log.u_bbr.flex3 = tp->t_ccv.bytes_this_ack;
5508 		log.u_bbr.flex4 = tp->t_ccv.nsegs;
5509 		log.u_bbr.flex5 = V_tcp_abc_l_var;
5510 		log.u_bbr.flex6 = orig_cwnd;
5511 		log.u_bbr.flex7 = V_tcp_do_newsack;
5512 		log.u_bbr.pkts_out = rack->r_ctl.rc_prr_sndcnt;
5513 		log.u_bbr.flex8 = 2;
5514 		tcp_log_event(tp, NULL, NULL, NULL, BBR_LOG_CWND, 0,
5515 			       0, &log, false, NULL, __func__, __LINE__, &tv);
5516 	}
5517 	if ((rack->rack_no_prr == 0) &&
5518 	    (rack->no_prr_addback == 0) &&
5519 	    (rack->r_ctl.rc_prr_sndcnt > 0)) {
5520 		/*
5521 		 * Suck the next prr cnt back into cwnd, but
5522 		 * only do that if we are not application limited.
5523 		 */
5524 		if (ctf_outstanding(tp) <= sbavail(&tptosocket(tp)->so_snd)) {
5525 			/*
5526 			 * We are allowed to add back to the cwnd the amount we did
5527 			 * not get out if:
5528 			 * a) no_prr_addback is off.
5529 			 * b) we are not app limited
5530 			 * c) we are doing prr
5531 			 * <and>
5532 			 * d) it is bounded by rack_prr_addbackmax (if addback is 0, then none).
5533 			 */
5534 			tp->snd_cwnd += min((ctf_fixed_maxseg(tp) * rack_prr_addbackmax),
5535 					    rack->r_ctl.rc_prr_sndcnt);
5536 		}
5537 		rack->r_ctl.rc_prr_sndcnt = 0;
5538 		rack_log_to_prr(rack, 1, 0, __LINE__);
5539 	}
5540 	rack_log_to_prr(rack, 14, orig_cwnd, __LINE__);
5541 	tp->snd_recover = tp->snd_una;
5542 	if (rack->r_ctl.dsack_persist) {
5543 		rack->r_ctl.dsack_persist--;
5544 		if (rack->r_ctl.num_dsack && (rack->r_ctl.dsack_persist == 0)) {
5545 			rack->r_ctl.num_dsack = 0;
5546 		}
5547 		rack_log_dsack_event(rack, 1, __LINE__, 0, 0);
5548 	}
5549 	if (rack->rto_from_rec == 1) {
5550 		rack->rto_from_rec = 0;
5551 		if (rack->r_ctl.rto_ssthresh > tp->snd_ssthresh)
5552 			tp->snd_ssthresh = rack->r_ctl.rto_ssthresh;
5553 	}
5554 	rack_exit_recovery(tp, rack, 1);
5555 }
5556 
5557 static void
5558 rack_cong_signal(struct tcpcb *tp, uint32_t type, uint32_t ack, int line)
5559 {
5560 	struct tcp_rack *rack;
5561 	uint32_t ssthresh_enter, cwnd_enter, in_rec_at_entry, orig_cwnd;
5562 
5563 	INP_WLOCK_ASSERT(tptoinpcb(tp));
5564 #ifdef STATS
5565 	stats_voi_update_abs_u32(tp->t_stats, VOI_TCP_CSIG, type);
5566 #endif
5567 	if (IN_RECOVERY(tp->t_flags) == 0) {
5568 		in_rec_at_entry = 0;
5569 		ssthresh_enter = tp->snd_ssthresh;
5570 		cwnd_enter = tp->snd_cwnd;
5571 	} else
5572 		in_rec_at_entry = 1;
5573 	rack = (struct tcp_rack *)tp->t_fb_ptr;
5574 	switch (type) {
5575 	case CC_NDUPACK:
5576 		tp->t_flags &= ~TF_WASFRECOVERY;
5577 		tp->t_flags &= ~TF_WASCRECOVERY;
5578 		if (!IN_FASTRECOVERY(tp->t_flags)) {
5579 			/* Check if this is the end of the initial Start-up i.e. initial slow-start */
5580 			if (rack->rc_initial_ss_comp == 0) {
5581 				/* Yep it is the end of the initial slowstart */
5582 				rack->rc_initial_ss_comp = 1;
5583 			}
5584 			rack->r_ctl.rc_prr_delivered = 0;
5585 			rack->r_ctl.rc_prr_out = 0;
5586 			rack->r_fast_output = 0;
5587 			if (rack->rack_no_prr == 0) {
5588 				rack->r_ctl.rc_prr_sndcnt = ctf_fixed_maxseg(tp);
5589 				rack_log_to_prr(rack, 2, in_rec_at_entry, line);
5590 			}
5591 			rack->r_ctl.rc_prr_recovery_fs = tp->snd_max - tp->snd_una;
5592 			tp->snd_recover = tp->snd_max;
5593 			if (tp->t_flags2 & TF2_ECN_PERMIT)
5594 				tp->t_flags2 |= TF2_ECN_SND_CWR;
5595 		}
5596 		break;
5597 	case CC_ECN:
5598 		if (!IN_CONGRECOVERY(tp->t_flags) ||
5599 		    /*
5600 		     * Allow ECN reaction on ACK to CWR, if
5601 		     * that data segment was also CE marked.
5602 		     */
5603 		    SEQ_GEQ(ack, tp->snd_recover)) {
5604 			EXIT_CONGRECOVERY(tp->t_flags);
5605 			KMOD_TCPSTAT_INC(tcps_ecn_rcwnd);
5606 			rack->r_fast_output = 0;
5607 			tp->snd_recover = tp->snd_max + 1;
5608 			if (tp->t_flags2 & TF2_ECN_PERMIT)
5609 				tp->t_flags2 |= TF2_ECN_SND_CWR;
5610 		}
5611 		break;
5612 	case CC_RTO:
5613 		tp->t_dupacks = 0;
5614 		tp->t_bytes_acked = 0;
5615 		rack->r_fast_output = 0;
5616 		if (IN_RECOVERY(tp->t_flags))
5617 			rack_exit_recovery(tp, rack, 2);
5618 		orig_cwnd = tp->snd_cwnd;
5619 		rack_log_to_prr(rack, 16, orig_cwnd, line);
5620 		if (CC_ALGO(tp)->cong_signal == NULL) {
5621 			/* TSNH */
5622 			tp->snd_ssthresh = max(2,
5623 			    min(tp->snd_wnd, rack->r_ctl.cwnd_to_use) / 2 /
5624 			    ctf_fixed_maxseg(tp)) * ctf_fixed_maxseg(tp);
5625 			tp->snd_cwnd = ctf_fixed_maxseg(tp);
5626 		}
5627 		if (tp->t_flags2 & TF2_ECN_PERMIT)
5628 			tp->t_flags2 |= TF2_ECN_SND_CWR;
5629 		break;
5630 	case CC_RTO_ERR:
5631 		KMOD_TCPSTAT_INC(tcps_sndrexmitbad);
5632 		/* RTO was unnecessary, so reset everything. */
5633 		tp->snd_cwnd = tp->snd_cwnd_prev;
5634 		tp->snd_ssthresh = tp->snd_ssthresh_prev;
5635 		tp->snd_recover = tp->snd_recover_prev;
5636 		if (tp->t_flags & TF_WASFRECOVERY) {
5637 			ENTER_FASTRECOVERY(tp->t_flags);
5638 			tp->t_flags &= ~TF_WASFRECOVERY;
5639 		}
5640 		if (tp->t_flags & TF_WASCRECOVERY) {
5641 			ENTER_CONGRECOVERY(tp->t_flags);
5642 			tp->t_flags &= ~TF_WASCRECOVERY;
5643 		}
5644 		tp->snd_nxt = tp->snd_max;
5645 		tp->t_badrxtwin = 0;
5646 		break;
5647 	}
5648 	if ((CC_ALGO(tp)->cong_signal != NULL) &&
5649 	    (type != CC_RTO)){
5650 		tp->t_ccv.curack = ack;
5651 		CC_ALGO(tp)->cong_signal(&tp->t_ccv, type);
5652 	}
5653 	if ((in_rec_at_entry == 0) && IN_RECOVERY(tp->t_flags)) {
5654 		rack_log_to_prr(rack, 15, cwnd_enter, line);
5655 		rack->r_ctl.dsack_byte_cnt = 0;
5656 		rack->r_ctl.retran_during_recovery = 0;
5657 		rack->r_ctl.rc_cwnd_at_erec = cwnd_enter;
5658 		rack->r_ctl.rc_ssthresh_at_erec = ssthresh_enter;
5659 		rack->r_ent_rec_ns = 1;
5660 	}
5661 }
5662 
5663 static inline void
5664 rack_cc_after_idle(struct tcp_rack *rack, struct tcpcb *tp)
5665 {
5666 	uint32_t i_cwnd;
5667 
5668 	INP_WLOCK_ASSERT(tptoinpcb(tp));
5669 
5670 	if (CC_ALGO(tp)->after_idle != NULL)
5671 		CC_ALGO(tp)->after_idle(&tp->t_ccv);
5672 
5673 	if (tp->snd_cwnd == 1)
5674 		i_cwnd = tp->t_maxseg;		/* SYN(-ACK) lost */
5675 	else
5676 		i_cwnd = rc_init_window(rack);
5677 
5678 	/*
5679 	 * Being idle is no different than the initial window. If the cc
5680 	 * clamps it down below the initial window raise it to the initial
5681 	 * window.
5682 	 */
5683 	if (tp->snd_cwnd < i_cwnd) {
5684 		tp->snd_cwnd = i_cwnd;
5685 	}
5686 }
5687 
5688 /*
5689  * Indicate whether this ack should be delayed.  We can delay the ack if
5690  * following conditions are met:
5691  *	- There is no delayed ack timer in progress.
5692  *	- Our last ack wasn't a 0-sized window. We never want to delay
5693  *	  the ack that opens up a 0-sized window.
5694  *	- LRO wasn't used for this segment. We make sure by checking that the
5695  *	  segment size is not larger than the MSS.
5696  *	- Delayed acks are enabled or this is a half-synchronized T/TCP
5697  *	  connection.
5698  */
5699 #define DELAY_ACK(tp, tlen)			 \
5700 	(((tp->t_flags & TF_RXWIN0SENT) == 0) && \
5701 	((tp->t_flags & TF_DELACK) == 0) &&	 \
5702 	(tlen <= tp->t_maxseg) &&		 \
5703 	(tp->t_delayed_ack || (tp->t_flags & TF_NEEDSYN)))
5704 
5705 static struct rack_sendmap *
5706 rack_find_lowest_rsm(struct tcp_rack *rack)
5707 {
5708 	struct rack_sendmap *rsm;
5709 
5710 	/*
5711 	 * Walk the time-order transmitted list looking for an rsm that is
5712 	 * not acked. This will be the one that was sent the longest time
5713 	 * ago that is still outstanding.
5714 	 */
5715 	TAILQ_FOREACH(rsm, &rack->r_ctl.rc_tmap, r_tnext) {
5716 		if (rsm->r_flags & RACK_ACKED) {
5717 			continue;
5718 		}
5719 		goto finish;
5720 	}
5721 finish:
5722 	return (rsm);
5723 }
5724 
5725 static struct rack_sendmap *
5726 rack_find_high_nonack(struct tcp_rack *rack, struct rack_sendmap *rsm)
5727 {
5728 	struct rack_sendmap *prsm;
5729 
5730 	/*
5731 	 * Walk the sequence order list backward until we hit and arrive at
5732 	 * the highest seq not acked. In theory when this is called it
5733 	 * should be the last segment (which it was not).
5734 	 */
5735 	prsm = rsm;
5736 
5737 	TQHASH_FOREACH_REVERSE_FROM(prsm, rack->r_ctl.tqh) {
5738 		if (prsm->r_flags & (RACK_ACKED | RACK_HAS_FIN)) {
5739 			continue;
5740 		}
5741 		return (prsm);
5742 	}
5743 	return (NULL);
5744 }
5745 
5746 static uint32_t
5747 rack_calc_thresh_rack(struct tcp_rack *rack, uint32_t srtt, uint32_t cts, int line, int log_allowed)
5748 {
5749 	int32_t lro;
5750 	uint32_t thresh;
5751 
5752 	/*
5753 	 * lro is the flag we use to determine if we have seen reordering.
5754 	 * If it gets set we have seen reordering. The reorder logic either
5755 	 * works in one of two ways:
5756 	 *
5757 	 * If reorder-fade is configured, then we track the last time we saw
5758 	 * re-ordering occur. If we reach the point where enough time as
5759 	 * passed we no longer consider reordering as occurring.
5760 	 *
5761 	 * Or if reorder-face is 0, then once we see reordering we consider
5762 	 * the connection to alway be subject to reordering and just set lro
5763 	 * to 1.
5764 	 *
5765 	 * In the end if lro is non-zero we add the extra time for
5766 	 * reordering in.
5767 	 */
5768 	if (srtt == 0)
5769 		srtt = 1;
5770 	if (rack->r_ctl.rc_reorder_ts) {
5771 		if (rack->r_ctl.rc_reorder_fade) {
5772 			if (SEQ_GEQ(cts, rack->r_ctl.rc_reorder_ts)) {
5773 				lro = cts - rack->r_ctl.rc_reorder_ts;
5774 				if (lro == 0) {
5775 					/*
5776 					 * No time as passed since the last
5777 					 * reorder, mark it as reordering.
5778 					 */
5779 					lro = 1;
5780 				}
5781 			} else {
5782 				/* Negative time? */
5783 				lro = 0;
5784 			}
5785 			if (lro > rack->r_ctl.rc_reorder_fade) {
5786 				/* Turn off reordering seen too */
5787 				rack->r_ctl.rc_reorder_ts = 0;
5788 				lro = 0;
5789 			}
5790 		} else {
5791 			/* Reodering does not fade */
5792 			lro = 1;
5793 		}
5794 	} else {
5795 		lro = 0;
5796 	}
5797 	if (rack->rc_rack_tmr_std_based == 0) {
5798 		thresh = srtt + rack->r_ctl.rc_pkt_delay;
5799 	} else {
5800 		/* Standards based pkt-delay is 1/4 srtt */
5801 		thresh = srtt +  (srtt >> 2);
5802 	}
5803 	if (lro && (rack->rc_rack_tmr_std_based == 0)) {
5804 		/* It must be set, if not you get 1/4 rtt */
5805 		if (rack->r_ctl.rc_reorder_shift)
5806 			thresh += (srtt >> rack->r_ctl.rc_reorder_shift);
5807 		else
5808 			thresh += (srtt >> 2);
5809 	}
5810 	if (rack->rc_rack_use_dsack &&
5811 	    lro &&
5812 	    (rack->r_ctl.num_dsack > 0)) {
5813 		/*
5814 		 * We only increase the reordering window if we
5815 		 * have seen reordering <and> we have a DSACK count.
5816 		 */
5817 		thresh += rack->r_ctl.num_dsack * (srtt >> 2);
5818 		if (log_allowed)
5819 			rack_log_dsack_event(rack, 4, line, srtt, thresh);
5820 	}
5821 	/* SRTT * 2 is the ceiling */
5822 	if (thresh > (srtt * 2)) {
5823 		thresh = srtt * 2;
5824 	}
5825 	/* And we don't want it above the RTO max either */
5826 	if (thresh > rack_rto_max) {
5827 		thresh = rack_rto_max;
5828 	}
5829 	if (log_allowed)
5830 		rack_log_dsack_event(rack, 6, line,  srtt, thresh);
5831 	return (thresh);
5832 }
5833 
5834 static uint32_t
5835 rack_calc_thresh_tlp(struct tcpcb *tp, struct tcp_rack *rack,
5836 		     struct rack_sendmap *rsm, uint32_t srtt)
5837 {
5838 	struct rack_sendmap *prsm;
5839 	uint32_t thresh, len;
5840 	int segsiz;
5841 
5842 	if (srtt == 0)
5843 		srtt = 1;
5844 	if (rack->r_ctl.rc_tlp_threshold)
5845 		thresh = srtt + (srtt / rack->r_ctl.rc_tlp_threshold);
5846 	else
5847 		thresh = (srtt * 2);
5848 
5849 	/* Get the previous sent packet, if any */
5850 	segsiz = min(ctf_fixed_maxseg(tp), rack->r_ctl.rc_pace_min_segs);
5851 	len = rsm->r_end - rsm->r_start;
5852 	if (rack->rack_tlp_threshold_use == TLP_USE_ID) {
5853 		/* Exactly like the ID */
5854 		if (((tp->snd_max - tp->snd_una) - rack->r_ctl.rc_sacked + rack->r_ctl.rc_holes_rxt) <= segsiz) {
5855 			uint32_t alt_thresh;
5856 			/*
5857 			 * Compensate for delayed-ack with the d-ack time.
5858 			 */
5859 			alt_thresh = srtt + (srtt / 2) + rack_delayed_ack_time;
5860 			if (alt_thresh > thresh)
5861 				thresh = alt_thresh;
5862 		}
5863 	} else if (rack->rack_tlp_threshold_use == TLP_USE_TWO_ONE) {
5864 		/* 2.1 behavior */
5865 		prsm = TAILQ_PREV(rsm, rack_head, r_tnext);
5866 		if (prsm && (len <= segsiz)) {
5867 			/*
5868 			 * Two packets outstanding, thresh should be (2*srtt) +
5869 			 * possible inter-packet delay (if any).
5870 			 */
5871 			uint32_t inter_gap = 0;
5872 			int idx, nidx;
5873 
5874 			idx = rsm->r_rtr_cnt - 1;
5875 			nidx = prsm->r_rtr_cnt - 1;
5876 			if (rsm->r_tim_lastsent[nidx] >= prsm->r_tim_lastsent[idx]) {
5877 				/* Yes it was sent later (or at the same time) */
5878 				inter_gap = rsm->r_tim_lastsent[idx] - prsm->r_tim_lastsent[nidx];
5879 			}
5880 			thresh += inter_gap;
5881 		} else if (len <= segsiz) {
5882 			/*
5883 			 * Possibly compensate for delayed-ack.
5884 			 */
5885 			uint32_t alt_thresh;
5886 
5887 			alt_thresh = srtt + (srtt / 2) + rack_delayed_ack_time;
5888 			if (alt_thresh > thresh)
5889 				thresh = alt_thresh;
5890 		}
5891 	} else if (rack->rack_tlp_threshold_use == TLP_USE_TWO_TWO) {
5892 		/* 2.2 behavior */
5893 		if (len <= segsiz) {
5894 			uint32_t alt_thresh;
5895 			/*
5896 			 * Compensate for delayed-ack with the d-ack time.
5897 			 */
5898 			alt_thresh = srtt + (srtt / 2) + rack_delayed_ack_time;
5899 			if (alt_thresh > thresh)
5900 				thresh = alt_thresh;
5901 		}
5902 	}
5903 	/* Not above an RTO */
5904 	if (thresh > tp->t_rxtcur) {
5905 		thresh = tp->t_rxtcur;
5906 	}
5907 	/* Not above a RTO max */
5908 	if (thresh > rack_rto_max) {
5909 		thresh = rack_rto_max;
5910 	}
5911 	/* Apply user supplied min TLP */
5912 	if (thresh < rack_tlp_min) {
5913 		thresh = rack_tlp_min;
5914 	}
5915 	return (thresh);
5916 }
5917 
5918 static uint32_t
5919 rack_grab_rtt(struct tcpcb *tp, struct tcp_rack *rack)
5920 {
5921 	/*
5922 	 * We want the rack_rtt which is the
5923 	 * last rtt we measured. However if that
5924 	 * does not exist we fallback to the srtt (which
5925 	 * we probably will never do) and then as a last
5926 	 * resort we use RACK_INITIAL_RTO if no srtt is
5927 	 * yet set.
5928 	 */
5929 	if (rack->rc_rack_rtt)
5930 		return (rack->rc_rack_rtt);
5931 	else if (tp->t_srtt == 0)
5932 		return (RACK_INITIAL_RTO);
5933 	return (tp->t_srtt);
5934 }
5935 
5936 static struct rack_sendmap *
5937 rack_check_recovery_mode(struct tcpcb *tp, uint32_t tsused)
5938 {
5939 	/*
5940 	 * Check to see that we don't need to fall into recovery. We will
5941 	 * need to do so if our oldest transmit is past the time we should
5942 	 * have had an ack.
5943 	 */
5944 	struct tcp_rack *rack;
5945 	struct rack_sendmap *rsm;
5946 	int32_t idx;
5947 	uint32_t srtt, thresh;
5948 
5949 	rack = (struct tcp_rack *)tp->t_fb_ptr;
5950 	if (tqhash_empty(rack->r_ctl.tqh)) {
5951 		return (NULL);
5952 	}
5953 	rsm = TAILQ_FIRST(&rack->r_ctl.rc_tmap);
5954 	if (rsm == NULL)
5955 		return (NULL);
5956 
5957 
5958 	if (rsm->r_flags & RACK_ACKED) {
5959 		rsm = rack_find_lowest_rsm(rack);
5960 		if (rsm == NULL)
5961 			return (NULL);
5962 	}
5963 	idx = rsm->r_rtr_cnt - 1;
5964 	srtt = rack_grab_rtt(tp, rack);
5965 	thresh = rack_calc_thresh_rack(rack, srtt, tsused, __LINE__, 1);
5966 	if (TSTMP_LT(tsused, ((uint32_t)rsm->r_tim_lastsent[idx]))) {
5967 		return (NULL);
5968 	}
5969 	if ((tsused - ((uint32_t)rsm->r_tim_lastsent[idx])) < thresh) {
5970 		return (NULL);
5971 	}
5972 	/* Ok if we reach here we are over-due and this guy can be sent */
5973 	rack_cong_signal(tp, CC_NDUPACK, tp->snd_una, __LINE__);
5974 	return (rsm);
5975 }
5976 
5977 static uint32_t
5978 rack_get_persists_timer_val(struct tcpcb *tp, struct tcp_rack *rack)
5979 {
5980 	int32_t t;
5981 	int32_t tt;
5982 	uint32_t ret_val;
5983 
5984 	t = (tp->t_srtt + (tp->t_rttvar << 2));
5985 	RACK_TCPT_RANGESET(tt, t * tcp_backoff[tp->t_rxtshift],
5986  	    rack_persist_min, rack_persist_max, rack->r_ctl.timer_slop);
5987 	rack->r_ctl.rc_hpts_flags |= PACE_TMR_PERSIT;
5988 	ret_val = (uint32_t)tt;
5989 	return (ret_val);
5990 }
5991 
5992 static uint32_t
5993 rack_timer_start(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cts, int sup_rack)
5994 {
5995 	/*
5996 	 * Start the FR timer, we do this based on getting the first one in
5997 	 * the rc_tmap. Note that if its NULL we must stop the timer. in all
5998 	 * events we need to stop the running timer (if its running) before
5999 	 * starting the new one.
6000 	 */
6001 	uint32_t thresh, exp, to, srtt, time_since_sent, tstmp_touse;
6002 	uint32_t srtt_cur;
6003 	int32_t idx;
6004 	int32_t is_tlp_timer = 0;
6005 	struct rack_sendmap *rsm;
6006 
6007 	if (rack->t_timers_stopped) {
6008 		/* All timers have been stopped none are to run */
6009 		return (0);
6010 	}
6011 	if (rack->rc_in_persist) {
6012 		/* We can't start any timer in persists */
6013 		return (rack_get_persists_timer_val(tp, rack));
6014 	}
6015 	rack->rc_on_min_to = 0;
6016 	if ((tp->t_state < TCPS_ESTABLISHED) ||
6017 	    ((tp->t_flags & TF_SACK_PERMIT) == 0)) {
6018 		goto activate_rxt;
6019 	}
6020 	rsm = TAILQ_FIRST(&rack->r_ctl.rc_tmap);
6021 	if ((rsm == NULL) || sup_rack) {
6022 		/* Nothing on the send map or no rack */
6023 activate_rxt:
6024 		time_since_sent = 0;
6025 		rsm = TAILQ_FIRST(&rack->r_ctl.rc_tmap);
6026 		if (rsm) {
6027 			/*
6028 			 * Should we discount the RTX timer any?
6029 			 *
6030 			 * We want to discount it the smallest amount.
6031 			 * If a timer (Rack/TLP or RXT) has gone off more
6032 			 * recently thats the discount we want to use (now - timer time).
6033 			 * If the retransmit of the oldest packet was more recent then
6034 			 * we want to use that (now - oldest-packet-last_transmit_time).
6035 			 *
6036 			 */
6037 			idx = rsm->r_rtr_cnt - 1;
6038 			if (TSTMP_GEQ(rack->r_ctl.rc_tlp_rxt_last_time, ((uint32_t)rsm->r_tim_lastsent[idx])))
6039 				tstmp_touse = (uint32_t)rack->r_ctl.rc_tlp_rxt_last_time;
6040 			else
6041 				tstmp_touse = (uint32_t)rsm->r_tim_lastsent[idx];
6042 			if (TSTMP_GT(cts, tstmp_touse))
6043 			    time_since_sent = cts - tstmp_touse;
6044 		}
6045 		if (SEQ_LT(tp->snd_una, tp->snd_max) ||
6046 		    sbavail(&tptosocket(tp)->so_snd)) {
6047 			rack->r_ctl.rc_hpts_flags |= PACE_TMR_RXT;
6048 			to = tp->t_rxtcur;
6049 			if (to > time_since_sent)
6050 				to -= time_since_sent;
6051 			else
6052 				to = rack->r_ctl.rc_min_to;
6053 			if (to == 0)
6054 				to = 1;
6055 			/* Special case for KEEPINIT */
6056 			if ((TCPS_HAVEESTABLISHED(tp->t_state) == 0) &&
6057 			    (TP_KEEPINIT(tp) != 0) &&
6058 			    rsm) {
6059 				/*
6060 				 * We have to put a ceiling on the rxt timer
6061 				 * of the keep-init timeout.
6062 				 */
6063 				uint32_t max_time, red;
6064 
6065 				max_time = TICKS_2_USEC(TP_KEEPINIT(tp));
6066 				if (TSTMP_GT(cts, (uint32_t)rsm->r_tim_lastsent[0])) {
6067 					red = (cts - (uint32_t)rsm->r_tim_lastsent[0]);
6068 					if (red < max_time)
6069 						max_time -= red;
6070 					else
6071 						max_time = 1;
6072 				}
6073 				/* Reduce timeout to the keep value if needed */
6074 				if (max_time < to)
6075 					to = max_time;
6076 			}
6077 			return (to);
6078 		}
6079 		return (0);
6080 	}
6081 	if (rsm->r_flags & RACK_ACKED) {
6082 		rsm = rack_find_lowest_rsm(rack);
6083 		if (rsm == NULL) {
6084 			/* No lowest? */
6085 			goto activate_rxt;
6086 		}
6087 	}
6088 	/* Convert from ms to usecs */
6089 	if ((rsm->r_flags & RACK_SACK_PASSED) ||
6090 	    (rsm->r_flags & RACK_RWND_COLLAPSED) ||
6091 	    (rsm->r_dupack >= DUP_ACK_THRESHOLD)) {
6092 		if ((tp->t_flags & TF_SENTFIN) &&
6093 		    ((tp->snd_max - tp->snd_una) == 1) &&
6094 		    (rsm->r_flags & RACK_HAS_FIN)) {
6095 			/*
6096 			 * We don't start a rack timer if all we have is a
6097 			 * FIN outstanding.
6098 			 */
6099 			goto activate_rxt;
6100 		}
6101 		if ((rack->use_rack_rr == 0) &&
6102 		    (IN_FASTRECOVERY(tp->t_flags)) &&
6103 		    (rack->rack_no_prr == 0) &&
6104 		     (rack->r_ctl.rc_prr_sndcnt  < ctf_fixed_maxseg(tp))) {
6105 			/*
6106 			 * We are not cheating, in recovery  and
6107 			 * not enough ack's to yet get our next
6108 			 * retransmission out.
6109 			 *
6110 			 * Note that classified attackers do not
6111 			 * get to use the rack-cheat.
6112 			 */
6113 			goto activate_tlp;
6114 		}
6115 		srtt = rack_grab_rtt(tp, rack);
6116 		thresh = rack_calc_thresh_rack(rack, srtt, cts, __LINE__, 1);
6117 		idx = rsm->r_rtr_cnt - 1;
6118 		exp = ((uint32_t)rsm->r_tim_lastsent[idx]) + thresh;
6119 		if (SEQ_GEQ(exp, cts)) {
6120 			to = exp - cts;
6121 			if (to < rack->r_ctl.rc_min_to) {
6122 				to = rack->r_ctl.rc_min_to;
6123 				if (rack->r_rr_config == 3)
6124 					rack->rc_on_min_to = 1;
6125 			}
6126 		} else {
6127 			to = rack->r_ctl.rc_min_to;
6128 			if (rack->r_rr_config == 3)
6129 				rack->rc_on_min_to = 1;
6130 		}
6131 	} else {
6132 		/* Ok we need to do a TLP not RACK */
6133 activate_tlp:
6134 		if ((rack->rc_tlp_in_progress != 0) &&
6135 		    (rack->r_ctl.rc_tlp_cnt_out >= rack_tlp_limit)) {
6136 			/*
6137 			 * The previous send was a TLP and we have sent
6138 			 * N TLP's without sending new data.
6139 			 */
6140 			goto activate_rxt;
6141 		}
6142 		rsm = TAILQ_LAST_FAST(&rack->r_ctl.rc_tmap, rack_sendmap, r_tnext);
6143 		if (rsm == NULL) {
6144 			/* We found no rsm to TLP with. */
6145 			goto activate_rxt;
6146 		}
6147 		if (rsm->r_flags & RACK_HAS_FIN) {
6148 			/* If its a FIN we dont do TLP */
6149 			rsm = NULL;
6150 			goto activate_rxt;
6151 		}
6152 		idx = rsm->r_rtr_cnt - 1;
6153 		time_since_sent = 0;
6154 		if (TSTMP_GEQ(((uint32_t)rsm->r_tim_lastsent[idx]), rack->r_ctl.rc_tlp_rxt_last_time))
6155 			tstmp_touse = (uint32_t)rsm->r_tim_lastsent[idx];
6156 		else
6157 			tstmp_touse = (uint32_t)rack->r_ctl.rc_tlp_rxt_last_time;
6158 		if (TSTMP_GT(cts, tstmp_touse))
6159 		    time_since_sent = cts - tstmp_touse;
6160 		is_tlp_timer = 1;
6161 		if (tp->t_srtt) {
6162 			if ((rack->rc_srtt_measure_made == 0) &&
6163 			    (tp->t_srtt == 1)) {
6164 				/*
6165 				 * If another stack as run and set srtt to 1,
6166 				 * then the srtt was 0, so lets use the initial.
6167 				 */
6168 				srtt = RACK_INITIAL_RTO;
6169 			} else {
6170 				srtt_cur = tp->t_srtt;
6171 				srtt = srtt_cur;
6172 			}
6173 		} else
6174 			srtt = RACK_INITIAL_RTO;
6175 		/*
6176 		 * If the SRTT is not keeping up and the
6177 		 * rack RTT has spiked we want to use
6178 		 * the last RTT not the smoothed one.
6179 		 */
6180 		if (rack_tlp_use_greater &&
6181 		    tp->t_srtt &&
6182 		    (srtt < rack_grab_rtt(tp, rack))) {
6183 			srtt = rack_grab_rtt(tp, rack);
6184 		}
6185 		thresh = rack_calc_thresh_tlp(tp, rack, rsm, srtt);
6186 		if (thresh > time_since_sent) {
6187 			to = thresh - time_since_sent;
6188 		} else {
6189 			to = rack->r_ctl.rc_min_to;
6190 			rack_log_alt_to_to_cancel(rack,
6191 						  thresh,		/* flex1 */
6192 						  time_since_sent,	/* flex2 */
6193 						  tstmp_touse,		/* flex3 */
6194 						  rack->r_ctl.rc_tlp_rxt_last_time, /* flex4 */
6195 						  (uint32_t)rsm->r_tim_lastsent[idx],
6196 						  srtt,
6197 						  idx, 99);
6198 		}
6199 		if (to < rack_tlp_min) {
6200 			to = rack_tlp_min;
6201 		}
6202 		if (to > TICKS_2_USEC(tcp_rexmit_max)) {
6203 			/*
6204 			 * If the TLP time works out to larger than the max
6205 			 * RTO lets not do TLP.. just RTO.
6206 			 */
6207 			goto activate_rxt;
6208 		}
6209 	}
6210 	if (is_tlp_timer == 0) {
6211 		rack->r_ctl.rc_hpts_flags |= PACE_TMR_RACK;
6212 	} else {
6213 		rack->r_ctl.rc_hpts_flags |= PACE_TMR_TLP;
6214 	}
6215 	if (to == 0)
6216 		to = 1;
6217 	return (to);
6218 }
6219 
6220 static void
6221 rack_enter_persist(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cts, tcp_seq snd_una)
6222 {
6223 	if (rack->rc_in_persist == 0) {
6224 		if (tp->t_flags & TF_GPUTINPROG) {
6225 			/*
6226 			 * Stop the goodput now, the calling of the
6227 			 * measurement function clears the flag.
6228 			 */
6229 			rack_do_goodput_measurement(tp, rack, tp->snd_una, __LINE__,
6230 						    RACK_QUALITY_PERSIST);
6231 		}
6232 #ifdef NETFLIX_SHARED_CWND
6233 		if (rack->r_ctl.rc_scw) {
6234 			tcp_shared_cwnd_idle(rack->r_ctl.rc_scw, rack->r_ctl.rc_scw_index);
6235 			rack->rack_scwnd_is_idle = 1;
6236 		}
6237 #endif
6238 		rack->r_ctl.rc_went_idle_time = cts;
6239 		if (rack->r_ctl.rc_went_idle_time == 0)
6240 			rack->r_ctl.rc_went_idle_time = 1;
6241 		if (rack->lt_bw_up) {
6242 			/* Suspend our LT BW measurement */
6243 			uint64_t tmark;
6244 
6245 			rack->r_ctl.lt_bw_bytes += (snd_una - rack->r_ctl.lt_seq);
6246 			rack->r_ctl.lt_seq = snd_una;
6247 			tmark = tcp_tv_to_lusec(&rack->r_ctl.act_rcv_time);
6248 			if (tmark >= rack->r_ctl.lt_timemark) {
6249 				rack->r_ctl.lt_bw_time += (tmark - rack->r_ctl.lt_timemark);
6250 			}
6251 			rack->r_ctl.lt_timemark = tmark;
6252 			rack->lt_bw_up = 0;
6253 			rack->r_persist_lt_bw_off = 1;
6254 		}
6255 		rack_timer_cancel(tp, rack, cts, __LINE__);
6256 		rack->r_ctl.persist_lost_ends = 0;
6257 		rack->probe_not_answered = 0;
6258 		rack->forced_ack = 0;
6259 		tp->t_rxtshift = 0;
6260 		RACK_TCPT_RANGESET(tp->t_rxtcur, RACK_REXMTVAL(tp),
6261 			      rack_rto_min, rack_rto_max, rack->r_ctl.timer_slop);
6262 		rack->rc_in_persist = 1;
6263 	}
6264 }
6265 
6266 static void
6267 rack_exit_persist(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cts)
6268 {
6269 	if (tcp_in_hpts(rack->rc_tp)) {
6270 		tcp_hpts_remove(rack->rc_tp);
6271 		rack->r_ctl.rc_hpts_flags = 0;
6272 	}
6273 #ifdef NETFLIX_SHARED_CWND
6274 	if (rack->r_ctl.rc_scw) {
6275 		tcp_shared_cwnd_active(rack->r_ctl.rc_scw, rack->r_ctl.rc_scw_index);
6276 		rack->rack_scwnd_is_idle = 0;
6277 	}
6278 #endif
6279 	if (rack->rc_gp_dyn_mul &&
6280 	    (rack->use_fixed_rate == 0) &&
6281 	    (rack->rc_always_pace)) {
6282 		/*
6283 		 * Do we count this as if a probe-rtt just
6284 		 * finished?
6285 		 */
6286 		uint32_t time_idle, idle_min;
6287 
6288 		time_idle = cts - rack->r_ctl.rc_went_idle_time;
6289 		idle_min = rack_min_probertt_hold;
6290 		if (rack_probertt_gpsrtt_cnt_div) {
6291 			uint64_t extra;
6292 			extra = (uint64_t)rack->r_ctl.rc_gp_srtt *
6293 				(uint64_t)rack_probertt_gpsrtt_cnt_mul;
6294 			extra /= (uint64_t)rack_probertt_gpsrtt_cnt_div;
6295 			idle_min += (uint32_t)extra;
6296 		}
6297 		if (time_idle >= idle_min) {
6298 			/* Yes, we count it as a probe-rtt. */
6299 			uint32_t us_cts;
6300 
6301 			us_cts = tcp_get_usecs(NULL);
6302 			if (rack->in_probe_rtt == 0) {
6303 				rack->r_ctl.rc_lower_rtt_us_cts = us_cts;
6304 				rack->r_ctl.rc_time_probertt_entered = rack->r_ctl.rc_lower_rtt_us_cts;
6305 				rack->r_ctl.rc_time_probertt_starts = rack->r_ctl.rc_lower_rtt_us_cts;
6306 				rack->r_ctl.rc_time_of_last_probertt = rack->r_ctl.rc_lower_rtt_us_cts;
6307 			} else {
6308 				rack_exit_probertt(rack, us_cts);
6309 			}
6310 		}
6311 	}
6312 	if (rack->r_persist_lt_bw_off) {
6313 		/* Continue where we left off */
6314 		rack->r_ctl.lt_timemark = tcp_get_u64_usecs(NULL);
6315 		rack->lt_bw_up = 1;
6316 		rack->r_persist_lt_bw_off = 0;
6317 	}
6318 	rack->rc_in_persist = 0;
6319 	rack->r_ctl.rc_went_idle_time = 0;
6320 	tp->t_rxtshift = 0;
6321 	RACK_TCPT_RANGESET(tp->t_rxtcur, RACK_REXMTVAL(tp),
6322 	   rack_rto_min, rack_rto_max, rack->r_ctl.timer_slop);
6323 	rack->r_ctl.rc_agg_delayed = 0;
6324 	rack->r_early = 0;
6325 	rack->r_late = 0;
6326 	rack->r_ctl.rc_agg_early = 0;
6327 }
6328 
6329 static void
6330 rack_log_hpts_diag(struct tcp_rack *rack, uint32_t cts,
6331 		   struct hpts_diag *diag, struct timeval *tv)
6332 {
6333 	if (rack_verbose_logging && tcp_bblogging_on(rack->rc_tp)) {
6334 		union tcp_log_stackspecific log;
6335 
6336 		memset(&log, 0, sizeof(log));
6337 		log.u_bbr.flex1 = diag->p_nxt_slot;
6338 		log.u_bbr.flex2 = diag->p_cur_slot;
6339 		log.u_bbr.flex3 = diag->slot_req;
6340 		log.u_bbr.flex4 = diag->inp_hptsslot;
6341 		log.u_bbr.flex5 = diag->time_remaining;
6342 		log.u_bbr.flex6 = diag->need_new_to;
6343 		log.u_bbr.flex7 = diag->p_hpts_active;
6344 		log.u_bbr.flex8 = diag->p_on_min_sleep;
6345 		/* Hijack other fields as needed */
6346 		log.u_bbr.epoch = diag->have_slept;
6347 		log.u_bbr.lt_epoch = diag->yet_to_sleep;
6348 		log.u_bbr.pkts_out = diag->co_ret;
6349 		log.u_bbr.applimited = diag->hpts_sleep_time;
6350 		log.u_bbr.delivered = diag->p_prev_slot;
6351 		log.u_bbr.inflight = diag->p_runningslot;
6352 		log.u_bbr.bw_inuse = diag->wheel_slot;
6353 		log.u_bbr.rttProp = diag->wheel_cts;
6354 		log.u_bbr.timeStamp = cts;
6355 		log.u_bbr.delRate = diag->maxslots;
6356 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
6357 		    &rack->rc_inp->inp_socket->so_rcv,
6358 		    &rack->rc_inp->inp_socket->so_snd,
6359 		    BBR_LOG_HPTSDIAG, 0,
6360 		    0, &log, false, tv);
6361 	}
6362 
6363 }
6364 
6365 static void
6366 rack_log_wakeup(struct tcpcb *tp, struct tcp_rack *rack, struct sockbuf *sb, uint32_t len, int type)
6367 {
6368 	if (rack_verbose_logging && tcp_bblogging_on(rack->rc_tp)) {
6369 		union tcp_log_stackspecific log;
6370 		struct timeval tv;
6371 
6372 		memset(&log, 0, sizeof(log));
6373 		log.u_bbr.flex1 = sb->sb_flags;
6374 		log.u_bbr.flex2 = len;
6375 		log.u_bbr.flex3 = sb->sb_state;
6376 		log.u_bbr.flex8 = type;
6377 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
6378 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
6379 		    &rack->rc_inp->inp_socket->so_rcv,
6380 		    &rack->rc_inp->inp_socket->so_snd,
6381 		    TCP_LOG_SB_WAKE, 0,
6382 		    len, &log, false, &tv);
6383 	}
6384 }
6385 
6386 static void
6387 rack_start_hpts_timer (struct tcp_rack *rack, struct tcpcb *tp, uint32_t cts,
6388       int32_t usecs, uint32_t tot_len_this_send, int sup_rack)
6389 {
6390 	struct hpts_diag diag;
6391 	struct inpcb *inp = tptoinpcb(tp);
6392 	struct timeval tv;
6393 	uint32_t delayed_ack = 0;
6394 	uint32_t hpts_timeout;
6395 	uint32_t entry_usecs = usecs;
6396 	uint8_t stopped;
6397 	uint32_t left = 0;
6398 	uint32_t us_cts;
6399 
6400 	if ((tp->t_state == TCPS_CLOSED) ||
6401 	    (tp->t_state == TCPS_LISTEN)) {
6402 		return;
6403 	}
6404 	if (tcp_in_hpts(tp)) {
6405 		/* Already on the pacer */
6406 		return;
6407 	}
6408 	stopped = rack->rc_tmr_stopped;
6409 	if (stopped && TSTMP_GT(rack->r_ctl.rc_timer_exp, cts)) {
6410 		left = rack->r_ctl.rc_timer_exp - cts;
6411 	}
6412 	rack->r_ctl.rc_timer_exp = 0;
6413 	rack->r_ctl.rc_hpts_flags = 0;
6414 	us_cts = tcp_get_usecs(&tv);
6415 	/* Now early/late accounting */
6416 	rack_log_pacing_delay_calc(rack, entry_usecs, usecs, 0, 0, 0, 26, __LINE__, NULL, 0);
6417 	if (rack->r_early && (rack->rc_ack_can_sendout_data == 0)) {
6418 		/*
6419 		 * We have a early carry over set,
6420 		 * we can always add more time so we
6421 		 * can always make this compensation.
6422 		 *
6423 		 * Note if ack's are allowed to wake us do not
6424 		 * penalize the next timer for being awoke
6425 		 * by an ack aka the rc_agg_early (non-paced mode).
6426 		 */
6427 		usecs += rack->r_ctl.rc_agg_early;
6428 		rack->r_early = 0;
6429 		rack->r_ctl.rc_agg_early = 0;
6430 	}
6431 	if ((rack->r_late) &&
6432 	    ((rack->r_use_hpts_min == 0) || (rack->dgp_on == 0))) {
6433 		/*
6434 		 * This is harder, we can
6435 		 * compensate some but it
6436 		 * really depends on what
6437 		 * the current pacing time is.
6438 		 */
6439 		if (rack->r_ctl.rc_agg_delayed >= usecs) {
6440 			/*
6441 			 * We can't compensate for it all.
6442 			 * And we have to have some time
6443 			 * on the clock. We always have a min
6444 			 * 10 HPTS timer units (10 x 10 i.e. 100 usecs).
6445 			 */
6446 			if (usecs <= HPTS_USECS_PER_SLOT) {
6447 				/* We gain delay */
6448 				rack->r_ctl.rc_agg_delayed += (HPTS_USECS_PER_SLOT - usecs);
6449 				usecs = HPTS_USECS_PER_SLOT;
6450 			} else {
6451 				/* We take off some */
6452 				rack->r_ctl.rc_agg_delayed -= (usecs - HPTS_USECS_PER_SLOT);
6453 				usecs = HPTS_USECS_PER_SLOT;
6454 			}
6455 		} else {
6456 			usecs -= rack->r_ctl.rc_agg_delayed;
6457 			rack->r_ctl.rc_agg_delayed = 0;
6458 			/* Make sure we have 100 useconds at minimum */
6459 			if (usecs < HPTS_USECS_PER_SLOT) {
6460 				rack->r_ctl.rc_agg_delayed = HPTS_USECS_PER_SLOT - usecs;
6461 				usecs = HPTS_USECS_PER_SLOT;
6462 			}
6463 			if (rack->r_ctl.rc_agg_delayed == 0)
6464 				rack->r_late = 0;
6465 		}
6466 	} else if (rack->r_late) {
6467 		/* r_use_hpts_min is on and so is DGP */
6468 		uint32_t max_red;
6469 
6470 		max_red = (usecs * rack->r_ctl.max_reduction) / 100;
6471 		if (max_red >= rack->r_ctl.rc_agg_delayed) {
6472 			usecs -= rack->r_ctl.rc_agg_delayed;
6473 			rack->r_ctl.rc_agg_delayed = 0;
6474 		} else {
6475 			usecs -= max_red;
6476 			rack->r_ctl.rc_agg_delayed -= max_red;
6477 		}
6478 	}
6479 	if ((rack->r_use_hpts_min == 1) &&
6480 	    (usecs > 0) &&
6481 	    (rack->dgp_on == 1)) {
6482 		/*
6483 		 * We are enforcing a min pacing timer
6484 		 * based on our hpts min timeout.
6485 		 */
6486 		uint32_t min;
6487 
6488 		min = get_hpts_min_sleep_time();
6489 		if (min > usecs) {
6490 			usecs = min;
6491 		}
6492 	}
6493 	hpts_timeout = rack_timer_start(tp, rack, cts, sup_rack);
6494 	if (tp->t_flags & TF_DELACK) {
6495 		delayed_ack = TICKS_2_USEC(tcp_delacktime);
6496 		rack->r_ctl.rc_hpts_flags |= PACE_TMR_DELACK;
6497 	}
6498 	if (delayed_ack && ((hpts_timeout == 0) ||
6499 			    (delayed_ack < hpts_timeout)))
6500 		hpts_timeout = delayed_ack;
6501 	else
6502 		rack->r_ctl.rc_hpts_flags &= ~PACE_TMR_DELACK;
6503 	/*
6504 	 * If no timers are going to run and we will fall off the hptsi
6505 	 * wheel, we resort to a keep-alive timer if its configured.
6506 	 */
6507 	if ((hpts_timeout == 0) &&
6508 	    (usecs == 0)) {
6509 		if ((V_tcp_always_keepalive || inp->inp_socket->so_options & SO_KEEPALIVE) &&
6510 		    (tp->t_state <= TCPS_CLOSING)) {
6511 			/*
6512 			 * Ok we have no timer (persists, rack, tlp, rxt  or
6513 			 * del-ack), we don't have segments being paced. So
6514 			 * all that is left is the keepalive timer.
6515 			 */
6516 			if (TCPS_HAVEESTABLISHED(tp->t_state)) {
6517 				/* Get the established keep-alive time */
6518 				hpts_timeout = TICKS_2_USEC(TP_KEEPIDLE(tp));
6519 			} else {
6520 				/*
6521 				 * Get the initial setup keep-alive time,
6522 				 * note that this is probably not going to
6523 				 * happen, since rack will be running a rxt timer
6524 				 * if a SYN of some sort is outstanding. It is
6525 				 * actually handled in rack_timeout_rxt().
6526 				 */
6527 				hpts_timeout = TICKS_2_USEC(TP_KEEPINIT(tp));
6528 			}
6529 			rack->r_ctl.rc_hpts_flags |= PACE_TMR_KEEP;
6530 			if (rack->in_probe_rtt) {
6531 				/*
6532 				 * We want to instead not wake up a long time from
6533 				 * now but to wake up about the time we would
6534 				 * exit probe-rtt and initiate a keep-alive ack.
6535 				 * This will get us out of probe-rtt and update
6536 				 * our min-rtt.
6537 				 */
6538 				hpts_timeout = rack_min_probertt_hold;
6539 			}
6540 		}
6541 	}
6542 	if (left && (stopped & (PACE_TMR_KEEP | PACE_TMR_DELACK)) ==
6543 	    (rack->r_ctl.rc_hpts_flags & PACE_TMR_MASK)) {
6544 		/*
6545 		 * RACK, TLP, persists and RXT timers all are restartable
6546 		 * based on actions input .. i.e we received a packet (ack
6547 		 * or sack) and that changes things (rw, or snd_una etc).
6548 		 * Thus we can restart them with a new value. For
6549 		 * keep-alive, delayed_ack we keep track of what was left
6550 		 * and restart the timer with a smaller value.
6551 		 */
6552 		if (left < hpts_timeout)
6553 			hpts_timeout = left;
6554 	}
6555 	if (hpts_timeout) {
6556 		/*
6557 		 * Hack alert for now we can't time-out over 2,147,483
6558 		 * seconds (a bit more than 596 hours), which is probably ok
6559 		 * :).
6560 		 */
6561 		if (hpts_timeout > 0x7ffffffe)
6562 			hpts_timeout = 0x7ffffffe;
6563 		rack->r_ctl.rc_timer_exp = cts + hpts_timeout;
6564 	}
6565 	rack_log_pacing_delay_calc(rack, entry_usecs, usecs, hpts_timeout, 0, 0, 27, __LINE__, NULL, 0);
6566 	if ((rack->gp_ready == 0) &&
6567 	    (rack->use_fixed_rate == 0) &&
6568 	    (hpts_timeout < usecs) &&
6569 	    (rack->r_ctl.rc_hpts_flags & (PACE_TMR_TLP|PACE_TMR_RXT))) {
6570 		/*
6571 		 * We have no good estimate yet for the
6572 		 * old clunky burst mitigation or the
6573 		 * real pacing. And the tlp or rxt is smaller
6574 		 * than the pacing calculation. Lets not
6575 		 * pace that long since we know the calculation
6576 		 * so far is not accurate.
6577 		 */
6578 		usecs = hpts_timeout;
6579 	}
6580 	/**
6581 	 * Turn off all the flags for queuing by default. The
6582 	 * flags have important meanings to what happens when
6583 	 * LRO interacts with the transport. Most likely (by default now)
6584 	 * mbuf_queueing and ack compression are on. So the transport
6585 	 * has a couple of flags that control what happens (if those
6586 	 * are not on then these flags won't have any effect since it
6587 	 * won't go through the queuing LRO path).
6588 	 *
6589 	 * TF2_MBUF_QUEUE_READY - This flags says that I am busy
6590 	 *                        pacing output, so don't disturb. But
6591 	 *                        it also means LRO can wake me if there
6592 	 *                        is a SACK arrival.
6593 	 *
6594 	 * TF2_DONT_SACK_QUEUE - This flag is used in conjunction
6595 	 *                       with the above flag (QUEUE_READY) and
6596 	 *                       when present it says don't even wake me
6597 	 *                       if a SACK arrives.
6598 	 *
6599 	 * The idea behind these flags is that if we are pacing we
6600 	 * set the MBUF_QUEUE_READY and only get woken up if
6601 	 * a SACK arrives (which could change things) or if
6602 	 * our pacing timer expires. If, however, we have a rack
6603 	 * timer running, then we don't even want a sack to wake
6604 	 * us since the rack timer has to expire before we can send.
6605 	 *
6606 	 * Other cases should usually have none of the flags set
6607 	 * so LRO can call into us.
6608 	 */
6609 	tp->t_flags2 &= ~(TF2_DONT_SACK_QUEUE|TF2_MBUF_QUEUE_READY);
6610 	if (usecs) {
6611 		rack->r_ctl.rc_hpts_flags |= PACE_PKT_OUTPUT;
6612 		rack->r_ctl.rc_last_output_to = us_cts + usecs;
6613 		/*
6614 		 * A pacing timer (usecs microseconds) is being set, in
6615 		 * such a case we cannot send (we are blocked by
6616 		 * the timer). So lets tell LRO that it should not
6617 		 * wake us unless there is a SACK. Note this only
6618 		 * will be effective if mbuf queueing is on or
6619 		 * compressed acks are being processed.
6620 		 */
6621 		tp->t_flags2 |= TF2_MBUF_QUEUE_READY;
6622 		/*
6623 		 * But wait if we have a Rack timer running
6624 		 * even a SACK should not disturb us (with
6625 		 * the exception of r_rr_config 3).
6626 		 */
6627 		if ((rack->r_ctl.rc_hpts_flags & PACE_TMR_RACK) ||
6628 		    (IN_RECOVERY(tp->t_flags))) {
6629 			if (rack->r_rr_config != 3)
6630 				tp->t_flags2 |= TF2_DONT_SACK_QUEUE;
6631 			else if (rack->rc_pace_dnd) {
6632 				/*
6633 				 * When DND is on, we only let a sack
6634 				 * interrupt us if we are not in recovery.
6635 				 *
6636 				 * If DND is off, then we never hit here
6637 				 * and let all sacks wake us up.
6638 				 *
6639 				 */
6640 				tp->t_flags2 |= TF2_DONT_SACK_QUEUE;
6641 			}
6642 		}
6643 		if (rack->rc_ack_can_sendout_data) {
6644 			/*
6645 			 * Ahh but wait, this is that special case
6646 			 * where the pacing timer can be disturbed
6647 			 * backout the changes (used for non-paced
6648 			 * burst limiting).
6649 			 */
6650 			tp->t_flags2 &= ~(TF2_DONT_SACK_QUEUE |
6651 			    TF2_MBUF_QUEUE_READY);
6652 		}
6653 		if ((rack->use_rack_rr) &&
6654 		    (rack->r_rr_config < 2) &&
6655 		    ((hpts_timeout) && (hpts_timeout < usecs))) {
6656 			/*
6657 			 * Arrange for the hpts to kick back in after the
6658 			 * t-o if the t-o does not cause a send.
6659 			 */
6660 			tcp_hpts_insert(tp, hpts_timeout, &diag);
6661 			rack_log_hpts_diag(rack, us_cts, &diag, &tv);
6662 			rack_log_to_start(rack, cts, hpts_timeout, usecs, 0);
6663 		} else {
6664 			tcp_hpts_insert(tp, usecs, &diag);
6665 			rack_log_hpts_diag(rack, us_cts, &diag, &tv);
6666 			rack_log_to_start(rack, cts, hpts_timeout, usecs, 1);
6667 		}
6668 	} else if (hpts_timeout) {
6669 		/*
6670 		 * With respect to t_flags2(?) here, lets let any new acks wake
6671 		 * us up here. Since we are not pacing (no pacing timer), output
6672 		 * can happen so we should let it. If its a Rack timer, then any inbound
6673 		 * packet probably won't change the sending (we will be blocked)
6674 		 * but it may change the prr stats so letting it in (the set defaults
6675 		 * at the start of this block) are good enough.
6676 		 */
6677 		rack->r_ctl.rc_hpts_flags &= ~PACE_PKT_OUTPUT;
6678 		tcp_hpts_insert(tp, hpts_timeout, &diag);
6679 		rack_log_hpts_diag(rack, us_cts, &diag, &tv);
6680 		rack_log_to_start(rack, cts, hpts_timeout, usecs, 0);
6681 	} else {
6682 		/* No timer starting */
6683 #ifdef INVARIANTS
6684 		if (SEQ_GT(tp->snd_max, tp->snd_una)) {
6685 			panic("tp:%p rack:%p tlts:%d cts:%u usecs:%u pto:%u -- no timer started?",
6686 			    tp, rack, tot_len_this_send, cts, usecs, hpts_timeout);
6687 		}
6688 #endif
6689 	}
6690 	rack->rc_tmr_stopped = 0;
6691 	if (usecs)
6692 		rack_log_type_bbrsnd(rack, tot_len_this_send, usecs, us_cts, &tv, __LINE__);
6693 }
6694 
6695 static void
6696 rack_mark_lost(struct tcpcb *tp,
6697     struct tcp_rack *rack, struct rack_sendmap *rsm, uint32_t cts)
6698 {
6699 	struct rack_sendmap *nrsm;
6700 	uint32_t thresh,  exp;
6701 
6702 	thresh = rack_calc_thresh_rack(rack, rack_grab_rtt(tp, rack), cts, __LINE__, 0);
6703 	nrsm = rsm;
6704 	TAILQ_FOREACH_FROM(nrsm, &rack->r_ctl.rc_tmap, r_tnext) {
6705 		if ((nrsm->r_flags & RACK_SACK_PASSED) == 0) {
6706 			/* Got up to all that were marked sack-passed */
6707 			break;
6708 		}
6709 		if ((nrsm->r_flags & RACK_WAS_LOST) == 0) {
6710 			exp = ((uint32_t)rsm->r_tim_lastsent[(rsm->r_rtr_cnt - 1)]) + thresh;
6711 			if (TSTMP_LT(exp, cts) || (exp == cts)) {
6712 				/* We now consider it lost */
6713 				nrsm->r_flags |= RACK_WAS_LOST;
6714 				rack->r_ctl.rc_considered_lost += nrsm->r_end - nrsm->r_start;
6715 			} else {
6716 				/* Past here it won't be lost so stop */
6717 				break;
6718 			}
6719 		}
6720 	}
6721 }
6722 
6723 static inline void
6724 rack_mark_nolonger_lost(struct tcp_rack *rack, struct rack_sendmap *rsm)
6725 {
6726 	KASSERT((rack->r_ctl.rc_considered_lost >= (rsm->r_end - rsm->r_start)),
6727 		("rsm:%p rack:%p rc_considered_lost goes negative", rsm,  rack));
6728 	rsm->r_flags &= ~RACK_WAS_LOST;
6729 	if (rack->r_ctl.rc_considered_lost >= (rsm->r_end - rsm->r_start))
6730 		rack->r_ctl.rc_considered_lost -= rsm->r_end - rsm->r_start;
6731 	else
6732 		rack->r_ctl.rc_considered_lost = 0;
6733 }
6734 
6735 /*
6736  * RACK Timer, here we simply do logging and house keeping.
6737  * the normal rack_output() function will call the
6738  * appropriate thing to check if we need to do a RACK retransmit.
6739  * We return 1, saying don't proceed with rack_output only
6740  * when all timers have been stopped (destroyed PCB?).
6741  */
6742 static int
6743 rack_timeout_rack(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cts)
6744 {
6745 	/*
6746 	 * This timer simply provides an internal trigger to send out data.
6747 	 * The check_recovery_mode call will see if there are needed
6748 	 * retransmissions, if so we will enter fast-recovery. The output
6749 	 * call may or may not do the same thing depending on sysctl
6750 	 * settings.
6751 	 */
6752 	struct rack_sendmap *rsm;
6753 
6754 	counter_u64_add(rack_to_tot, 1);
6755 	if (rack->r_state && (rack->r_state != tp->t_state))
6756 		rack_set_state(tp, rack);
6757 	rack->rc_on_min_to = 0;
6758 	rsm = rack_check_recovery_mode(tp, cts);
6759 	rack_log_to_event(rack, RACK_TO_FRM_RACK, rsm);
6760 	if (rsm) {
6761 		/* We need to stroke any lost that are now declared as lost */
6762 		rack_mark_lost(tp, rack, rsm, cts);
6763 		rack->r_ctl.rc_resend = rsm;
6764 		rack->r_timer_override = 1;
6765 		if (rack->use_rack_rr) {
6766 			/*
6767 			 * Don't accumulate extra pacing delay
6768 			 * we are allowing the rack timer to
6769 			 * over-ride pacing i.e. rrr takes precedence
6770 			 * if the pacing interval is longer than the rrr
6771 			 * time (in other words we get the min pacing
6772 			 * time versus rrr pacing time).
6773 			 */
6774 			rack->r_ctl.rc_hpts_flags &= ~PACE_PKT_OUTPUT;
6775 		}
6776 	}
6777 	rack->r_ctl.rc_hpts_flags &= ~PACE_TMR_RACK;
6778 	if (rsm == NULL) {
6779 		/* restart a timer and return 1 */
6780 		rack_start_hpts_timer(rack, tp, cts,
6781 				      0, 0, 0);
6782 		return (1);
6783 	}
6784 	return (0);
6785 }
6786 
6787 
6788 
6789 static void
6790 rack_adjust_orig_mlen(struct rack_sendmap *rsm)
6791 {
6792 
6793 	if ((M_TRAILINGROOM(rsm->m) != rsm->orig_t_space)) {
6794 		/*
6795 		 * The trailing space changed, mbufs can grow
6796 		 * at the tail but they can't shrink from
6797 		 * it, KASSERT that. Adjust the orig_m_len to
6798 		 * compensate for this change.
6799 		 */
6800 		KASSERT((rsm->orig_t_space > M_TRAILINGROOM(rsm->m)),
6801 			("mbuf:%p rsm:%p trailing_space:%jd ots:%u oml:%u mlen:%u\n",
6802 			 rsm->m,
6803 			 rsm,
6804 			 (intmax_t)M_TRAILINGROOM(rsm->m),
6805 			 rsm->orig_t_space,
6806 			 rsm->orig_m_len,
6807 			 rsm->m->m_len));
6808 		rsm->orig_m_len += (rsm->orig_t_space - M_TRAILINGROOM(rsm->m));
6809 		rsm->orig_t_space = M_TRAILINGROOM(rsm->m);
6810 	}
6811 	if (rsm->m->m_len < rsm->orig_m_len) {
6812 		/*
6813 		 * Mbuf shrank, trimmed off the top by an ack, our
6814 		 * offset changes.
6815 		 */
6816 		KASSERT((rsm->soff >= (rsm->orig_m_len - rsm->m->m_len)),
6817 			("mbuf:%p len:%u rsm:%p oml:%u soff:%u\n",
6818 			 rsm->m, rsm->m->m_len,
6819 			 rsm, rsm->orig_m_len,
6820 			 rsm->soff));
6821 		if (rsm->soff >= (rsm->orig_m_len - rsm->m->m_len))
6822 			rsm->soff -= (rsm->orig_m_len - rsm->m->m_len);
6823 		else
6824 			rsm->soff = 0;
6825 		rsm->orig_m_len = rsm->m->m_len;
6826 #ifdef INVARIANTS
6827 	} else if (rsm->m->m_len > rsm->orig_m_len) {
6828 		panic("rsm:%p m:%p m_len grew outside of t_space compensation",
6829 		      rsm, rsm->m);
6830 #endif
6831 	}
6832 }
6833 
6834 static void
6835 rack_setup_offset_for_rsm(struct tcp_rack *rack, struct rack_sendmap *src_rsm, struct rack_sendmap *rsm)
6836 {
6837 	struct mbuf *m;
6838 	uint32_t soff;
6839 
6840 	if (src_rsm->m &&
6841 	    ((src_rsm->orig_m_len != src_rsm->m->m_len) ||
6842 	     (M_TRAILINGROOM(src_rsm->m) != src_rsm->orig_t_space))) {
6843 		/* Fix up the orig_m_len and possibly the mbuf offset */
6844 		rack_adjust_orig_mlen(src_rsm);
6845 	}
6846 	m = src_rsm->m;
6847 	soff = src_rsm->soff + (src_rsm->r_end - src_rsm->r_start);
6848 	while (soff >= m->m_len) {
6849 		/* Move out past this mbuf */
6850 		soff -= m->m_len;
6851 		m = m->m_next;
6852 		KASSERT((m != NULL),
6853 			("rsm:%p nrsm:%p hit at soff:%u null m",
6854 			 src_rsm, rsm, soff));
6855 		if (m == NULL) {
6856 			/* This should *not* happen which is why there is a kassert */
6857 			src_rsm->m = sbsndmbuf(&rack->rc_inp->inp_socket->so_snd,
6858 					       (src_rsm->r_start - rack->rc_tp->snd_una),
6859 					       &src_rsm->soff);
6860 			src_rsm->orig_m_len = src_rsm->m->m_len;
6861 			src_rsm->orig_t_space = M_TRAILINGROOM(src_rsm->m);
6862 			rsm->m = sbsndmbuf(&rack->rc_inp->inp_socket->so_snd,
6863 					   (rsm->r_start - rack->rc_tp->snd_una),
6864 					   &rsm->soff);
6865 			rsm->orig_m_len = rsm->m->m_len;
6866 			rsm->orig_t_space = M_TRAILINGROOM(rsm->m);
6867 			return;
6868 		}
6869 	}
6870 	rsm->m = m;
6871 	rsm->soff = soff;
6872 	rsm->orig_m_len = m->m_len;
6873 	rsm->orig_t_space = M_TRAILINGROOM(rsm->m);
6874 }
6875 
6876 static inline void
6877 rack_clone_rsm(struct tcp_rack *rack, struct rack_sendmap *nrsm,
6878 	       struct rack_sendmap *rsm, uint32_t start)
6879 {
6880 	int idx;
6881 
6882 	nrsm->r_start = start;
6883 	nrsm->r_end = rsm->r_end;
6884 	nrsm->r_rtr_cnt = rsm->r_rtr_cnt;
6885 	nrsm->r_act_rxt_cnt = rsm->r_act_rxt_cnt;
6886 	nrsm->r_flags = rsm->r_flags;
6887 	nrsm->r_dupack = rsm->r_dupack;
6888 	nrsm->r_no_rtt_allowed = rsm->r_no_rtt_allowed;
6889 	nrsm->r_rtr_bytes = 0;
6890 	nrsm->r_fas = rsm->r_fas;
6891 	nrsm->r_bas = rsm->r_bas;
6892 	tqhash_update_end(rack->r_ctl.tqh, rsm, nrsm->r_start);
6893 	nrsm->r_just_ret = rsm->r_just_ret;
6894 	for (idx = 0; idx < nrsm->r_rtr_cnt; idx++) {
6895 		nrsm->r_tim_lastsent[idx] = rsm->r_tim_lastsent[idx];
6896 	}
6897 	/* Now if we have SYN flag we keep it on the left edge */
6898 	if (nrsm->r_flags & RACK_HAS_SYN)
6899 		nrsm->r_flags &= ~RACK_HAS_SYN;
6900 	/* Now if we have a FIN flag we keep it on the right edge */
6901 	if (rsm->r_flags & RACK_HAS_FIN)
6902 		rsm->r_flags &= ~RACK_HAS_FIN;
6903 	/* Push bit must go to the right edge as well */
6904 	if (rsm->r_flags & RACK_HAD_PUSH)
6905 		rsm->r_flags &= ~RACK_HAD_PUSH;
6906 	/* Update the count if app limited */
6907 	if (nrsm->r_flags & RACK_APP_LIMITED)
6908 		rack->r_ctl.rc_app_limited_cnt++;
6909 	/* Clone over the state of the hw_tls flag */
6910 	nrsm->r_hw_tls = rsm->r_hw_tls;
6911 	/*
6912 	 * Now we need to find nrsm's new location in the mbuf chain
6913 	 * we basically calculate a new offset, which is soff +
6914 	 * how much is left in original rsm. Then we walk out the mbuf
6915 	 * chain to find the righ position, it may be the same mbuf
6916 	 * or maybe not.
6917 	 */
6918 	KASSERT(((rsm->m != NULL) ||
6919 		 (rsm->r_flags & (RACK_HAS_SYN|RACK_HAS_FIN))),
6920 		("rsm:%p nrsm:%p rack:%p -- rsm->m is NULL?", rsm, nrsm, rack));
6921 	if (rsm->m)
6922 		rack_setup_offset_for_rsm(rack, rsm, nrsm);
6923 }
6924 
6925 static struct rack_sendmap *
6926 rack_merge_rsm(struct tcp_rack *rack,
6927 	       struct rack_sendmap *l_rsm,
6928 	       struct rack_sendmap *r_rsm)
6929 {
6930 	/*
6931 	 * We are merging two ack'd RSM's,
6932 	 * the l_rsm is on the left (lower seq
6933 	 * values) and the r_rsm is on the right
6934 	 * (higher seq value). The simplest way
6935 	 * to merge these is to move the right
6936 	 * one into the left. I don't think there
6937 	 * is any reason we need to try to find
6938 	 * the oldest (or last oldest retransmitted).
6939 	 */
6940 	rack_log_map_chg(rack->rc_tp, rack, NULL,
6941 			 l_rsm, r_rsm, MAP_MERGE, r_rsm->r_end, __LINE__);
6942 	tqhash_update_end(rack->r_ctl.tqh, l_rsm, r_rsm->r_end);
6943 	if (l_rsm->r_dupack < r_rsm->r_dupack)
6944 		l_rsm->r_dupack = r_rsm->r_dupack;
6945 	if (r_rsm->r_rtr_bytes)
6946 		l_rsm->r_rtr_bytes += r_rsm->r_rtr_bytes;
6947 	if (r_rsm->r_in_tmap) {
6948 		/* This really should not happen */
6949 		TAILQ_REMOVE(&rack->r_ctl.rc_tmap, r_rsm, r_tnext);
6950 		r_rsm->r_in_tmap = 0;
6951 	}
6952 
6953 	/* Now the flags */
6954 	if (r_rsm->r_flags & RACK_HAS_FIN)
6955 		l_rsm->r_flags |= RACK_HAS_FIN;
6956 	if (r_rsm->r_flags & RACK_TLP)
6957 		l_rsm->r_flags |= RACK_TLP;
6958 	if (r_rsm->r_flags & RACK_RWND_COLLAPSED)
6959 		l_rsm->r_flags |= RACK_RWND_COLLAPSED;
6960 	if ((r_rsm->r_flags & RACK_APP_LIMITED) &&
6961 	    ((l_rsm->r_flags & RACK_APP_LIMITED) == 0)) {
6962 		/*
6963 		 * If both are app-limited then let the
6964 		 * free lower the count. If right is app
6965 		 * limited and left is not, transfer.
6966 		 */
6967 		l_rsm->r_flags |= RACK_APP_LIMITED;
6968 		r_rsm->r_flags &= ~RACK_APP_LIMITED;
6969 		if (r_rsm == rack->r_ctl.rc_first_appl)
6970 			rack->r_ctl.rc_first_appl = l_rsm;
6971 	}
6972 	tqhash_remove(rack->r_ctl.tqh, r_rsm, REMOVE_TYPE_MERGE);
6973 	/*
6974 	 * We keep the largest value, which is the newest
6975 	 * send. We do this in case a segment that is
6976 	 * joined together and not part of a GP estimate
6977 	 * later gets expanded into the GP estimate.
6978 	 *
6979 	 * We prohibit the merging of unlike kinds i.e.
6980 	 * all pieces that are in the GP estimate can be
6981 	 * merged and all pieces that are not in a GP estimate
6982 	 * can be merged, but not disimilar pieces. Combine
6983 	 * this with taking the highest here and we should
6984 	 * be ok unless of course the client reneges. Then
6985 	 * all bets are off.
6986 	 */
6987 	if(l_rsm->r_tim_lastsent[(l_rsm->r_rtr_cnt-1)] <
6988 	   r_rsm->r_tim_lastsent[(r_rsm->r_rtr_cnt-1)]) {
6989 		l_rsm->r_tim_lastsent[(l_rsm->r_rtr_cnt-1)] = r_rsm->r_tim_lastsent[(r_rsm->r_rtr_cnt-1)];
6990 	}
6991 	/*
6992 	 * When merging two RSM's we also need to consider the ack time and keep
6993 	 * newest. If the ack gets merged into a measurement then that is the
6994 	 * one we will want to be using.
6995 	 */
6996 	if(l_rsm->r_ack_arrival	 < r_rsm->r_ack_arrival)
6997 		l_rsm->r_ack_arrival = r_rsm->r_ack_arrival;
6998 
6999 	if ((r_rsm->r_limit_type == 0) && (l_rsm->r_limit_type != 0)) {
7000 		/* Transfer the split limit to the map we free */
7001 		r_rsm->r_limit_type = l_rsm->r_limit_type;
7002 		l_rsm->r_limit_type = 0;
7003 	}
7004 	rack_free(rack, r_rsm);
7005 	l_rsm->r_flags |= RACK_MERGED;
7006 	return (l_rsm);
7007 }
7008 
7009 /*
7010  * TLP Timer, here we simply setup what segment we want to
7011  * have the TLP expire on, the normal rack_output() will then
7012  * send it out.
7013  *
7014  * We return 1, saying don't proceed with rack_output only
7015  * when all timers have been stopped (destroyed PCB?).
7016  */
7017 static int
7018 rack_timeout_tlp(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cts, uint8_t *doing_tlp)
7019 {
7020 	/*
7021 	 * Tail Loss Probe.
7022 	 */
7023 	struct rack_sendmap *rsm = NULL;
7024 	int insret __diagused;
7025 	struct socket *so = tptosocket(tp);
7026 	uint32_t amm;
7027 	uint32_t out, avail;
7028 	int collapsed_win = 0;
7029 
7030 	if (TSTMP_LT(cts, rack->r_ctl.rc_timer_exp)) {
7031 		/* Its not time yet */
7032 		return (0);
7033 	}
7034 	if (ctf_progress_timeout_check(tp, true)) {
7035 		rack_log_progress_event(rack, tp, tick, PROGRESS_DROP, __LINE__);
7036 		return (-ETIMEDOUT);	/* tcp_drop() */
7037 	}
7038 	/*
7039 	 * A TLP timer has expired. We have been idle for 2 rtts. So we now
7040 	 * need to figure out how to force a full MSS segment out.
7041 	 */
7042 	rack_log_to_event(rack, RACK_TO_FRM_TLP, NULL);
7043 	rack->r_ctl.retran_during_recovery = 0;
7044 	rack->r_might_revert = 0;
7045 	rack->r_ctl.dsack_byte_cnt = 0;
7046 	counter_u64_add(rack_tlp_tot, 1);
7047 	if (rack->r_state && (rack->r_state != tp->t_state))
7048 		rack_set_state(tp, rack);
7049 	avail = sbavail(&so->so_snd);
7050 	out = tp->snd_max - tp->snd_una;
7051 	if ((out > tp->snd_wnd) || rack->rc_has_collapsed) {
7052 		/* special case, we need a retransmission */
7053 		collapsed_win = 1;
7054 		goto need_retran;
7055 	}
7056 	if (rack->r_ctl.dsack_persist && (rack->r_ctl.rc_tlp_cnt_out >= 1)) {
7057 		rack->r_ctl.dsack_persist--;
7058 		if (rack->r_ctl.num_dsack && (rack->r_ctl.dsack_persist == 0)) {
7059 			rack->r_ctl.num_dsack = 0;
7060 		}
7061 		rack_log_dsack_event(rack, 1, __LINE__, 0, 0);
7062 	}
7063 	if ((tp->t_flags & TF_GPUTINPROG) &&
7064 	    (rack->r_ctl.rc_tlp_cnt_out == 1)) {
7065 		/*
7066 		 * If this is the second in a row
7067 		 * TLP and we are doing a measurement
7068 		 * its time to abandon the measurement.
7069 		 * Something is likely broken on
7070 		 * the clients network and measuring a
7071 		 * broken network does us no good.
7072 		 */
7073 		tp->t_flags &= ~TF_GPUTINPROG;
7074 		rack_log_pacing_delay_calc(rack, (tp->gput_ack - tp->gput_seq) /*flex2*/,
7075 					   rack->r_ctl.rc_gp_srtt /*flex1*/,
7076 					   tp->gput_seq,
7077 					   0, 0, 18, __LINE__, NULL, 0);
7078 	}
7079 	/*
7080 	 * Check our send oldest always settings, and if
7081 	 * there is an oldest to send jump to the need_retran.
7082 	 */
7083 	if (rack_always_send_oldest && (TAILQ_EMPTY(&rack->r_ctl.rc_tmap) == 0))
7084 		goto need_retran;
7085 
7086 	if (avail > out) {
7087 		/* New data is available */
7088 		amm = avail - out;
7089 		if (amm > ctf_fixed_maxseg(tp)) {
7090 			amm = ctf_fixed_maxseg(tp);
7091 			if ((amm + out) > tp->snd_wnd) {
7092 				/* We are rwnd limited */
7093 				goto need_retran;
7094 			}
7095 		} else if (amm < ctf_fixed_maxseg(tp)) {
7096 			/* not enough to fill a MTU */
7097 			goto need_retran;
7098 		}
7099 		if (IN_FASTRECOVERY(tp->t_flags)) {
7100 			/* Unlikely */
7101 			if (rack->rack_no_prr == 0) {
7102 				if (out + amm <= tp->snd_wnd) {
7103 					rack->r_ctl.rc_prr_sndcnt = amm;
7104 					rack->r_ctl.rc_tlp_new_data = amm;
7105 					rack_log_to_prr(rack, 4, 0, __LINE__);
7106 				}
7107 			} else
7108 				goto need_retran;
7109 		} else {
7110 			/* Set the send-new override */
7111 			if (out + amm <= tp->snd_wnd)
7112 				rack->r_ctl.rc_tlp_new_data = amm;
7113 			else
7114 				goto need_retran;
7115 		}
7116 		rack->r_ctl.rc_tlpsend = NULL;
7117 		counter_u64_add(rack_tlp_newdata, 1);
7118 		goto send;
7119 	}
7120 need_retran:
7121 	/*
7122 	 * Ok we need to arrange the last un-acked segment to be re-sent, or
7123 	 * optionally the first un-acked segment.
7124 	 */
7125 	if (collapsed_win == 0) {
7126 		if (rack_always_send_oldest)
7127 			rsm = TAILQ_FIRST(&rack->r_ctl.rc_tmap);
7128 		else {
7129 			rsm = tqhash_max(rack->r_ctl.tqh);
7130 			if (rsm && (rsm->r_flags & (RACK_ACKED | RACK_HAS_FIN))) {
7131 				rsm = rack_find_high_nonack(rack, rsm);
7132 			}
7133 		}
7134 		if (rsm == NULL) {
7135 #ifdef TCP_BLACKBOX
7136 			tcp_log_dump_tp_logbuf(tp, "nada counter trips", M_NOWAIT, true);
7137 #endif
7138 			goto out;
7139 		}
7140 	} else {
7141 		/*
7142 		 * We had a collapsed window, lets find
7143 		 * the point before the collapse.
7144 		 */
7145 		if (SEQ_GT((rack->r_ctl.last_collapse_point - 1), rack->rc_tp->snd_una))
7146 			rsm = tqhash_find(rack->r_ctl.tqh, (rack->r_ctl.last_collapse_point - 1));
7147 		else {
7148 			rsm = tqhash_min(rack->r_ctl.tqh);
7149 		}
7150 		if (rsm == NULL) {
7151 			/* Huh */
7152 			goto out;
7153 		}
7154 	}
7155 	if ((rsm->r_end - rsm->r_start) > ctf_fixed_maxseg(tp)) {
7156 		/*
7157 		 * We need to split this the last segment in two.
7158 		 */
7159 		struct rack_sendmap *nrsm;
7160 
7161 		nrsm = rack_alloc_full_limit(rack);
7162 		if (nrsm == NULL) {
7163 			/*
7164 			 * No memory to split, we will just exit and punt
7165 			 * off to the RXT timer.
7166 			 */
7167 			goto out;
7168 		}
7169 		rack_clone_rsm(rack, nrsm, rsm,
7170 			       (rsm->r_end - ctf_fixed_maxseg(tp)));
7171 		rack_log_map_chg(tp, rack, NULL, rsm, nrsm, MAP_SPLIT, 0, __LINE__);
7172 #ifndef INVARIANTS
7173 		(void)tqhash_insert(rack->r_ctl.tqh, nrsm);
7174 #else
7175 		if ((insret = tqhash_insert(rack->r_ctl.tqh, nrsm)) != 0) {
7176 			panic("Insert in tailq_hash of %p fails ret:%d rack:%p rsm:%p",
7177 			      nrsm, insret, rack, rsm);
7178 		}
7179 #endif
7180 		if (rsm->r_in_tmap) {
7181 			TAILQ_INSERT_AFTER(&rack->r_ctl.rc_tmap, rsm, nrsm, r_tnext);
7182 			nrsm->r_in_tmap = 1;
7183 		}
7184 		rsm = nrsm;
7185 	}
7186 	rack->r_ctl.rc_tlpsend = rsm;
7187 send:
7188 	/* Make sure output path knows we are doing a TLP */
7189 	*doing_tlp = 1;
7190 	rack->r_timer_override = 1;
7191 	rack->r_ctl.rc_hpts_flags &= ~PACE_TMR_TLP;
7192 	return (0);
7193 out:
7194 	rack->r_ctl.rc_hpts_flags &= ~PACE_TMR_TLP;
7195 	return (0);
7196 }
7197 
7198 /*
7199  * Delayed ack Timer, here we simply need to setup the
7200  * ACK_NOW flag and remove the DELACK flag. From there
7201  * the output routine will send the ack out.
7202  *
7203  * We only return 1, saying don't proceed, if all timers
7204  * are stopped (destroyed PCB?).
7205  */
7206 static int
7207 rack_timeout_delack(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cts)
7208 {
7209 
7210 	rack_log_to_event(rack, RACK_TO_FRM_DELACK, NULL);
7211 	tp->t_flags &= ~TF_DELACK;
7212 	tp->t_flags |= TF_ACKNOW;
7213 	KMOD_TCPSTAT_INC(tcps_delack);
7214 	rack->r_ctl.rc_hpts_flags &= ~PACE_TMR_DELACK;
7215 	return (0);
7216 }
7217 
7218 static inline int
7219 rack_send_ack_challange(struct tcp_rack *rack)
7220 {
7221 	struct tcptemp *t_template;
7222 
7223 	t_template = tcpip_maketemplate(rack->rc_inp);
7224 	if (t_template) {
7225 		if (rack->forced_ack == 0) {
7226 			rack->forced_ack = 1;
7227 			rack->r_ctl.forced_ack_ts = tcp_get_usecs(NULL);
7228 		} else {
7229 			rack->probe_not_answered = 1;
7230 		}
7231 		tcp_respond(rack->rc_tp, t_template->tt_ipgen,
7232 			    &t_template->tt_t, (struct mbuf *)NULL,
7233 			    rack->rc_tp->rcv_nxt, rack->rc_tp->snd_una - 1, 0);
7234 		free(t_template, M_TEMP);
7235 		/* This does send an ack so kill any D-ack timer */
7236 		if (rack->rc_tp->t_flags & TF_DELACK)
7237 			rack->rc_tp->t_flags &= ~TF_DELACK;
7238 		return(1);
7239 	} else
7240 		return (0);
7241 
7242 }
7243 
7244 /*
7245  * Persists timer, here we simply send the
7246  * same thing as a keepalive will.
7247  * the one byte send.
7248  *
7249  * We only return 1, saying don't proceed, if all timers
7250  * are stopped (destroyed PCB?).
7251  */
7252 static int
7253 rack_timeout_persist(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cts)
7254 {
7255 	int32_t retval = 1;
7256 
7257 	if (rack->rc_in_persist == 0)
7258 		return (0);
7259 	if (ctf_progress_timeout_check(tp, false)) {
7260 		tcp_log_end_status(tp, TCP_EI_STATUS_PERSIST_MAX);
7261 		rack_log_progress_event(rack, tp, tick, PROGRESS_DROP, __LINE__);
7262 		counter_u64_add(rack_persists_lost_ends, rack->r_ctl.persist_lost_ends);
7263 		return (-ETIMEDOUT);	/* tcp_drop() */
7264 	}
7265 	/*
7266 	 * Persistence timer into zero window. Force a byte to be output, if
7267 	 * possible.
7268 	 */
7269 	KMOD_TCPSTAT_INC(tcps_persisttimeo);
7270 	/*
7271 	 * Hack: if the peer is dead/unreachable, we do not time out if the
7272 	 * window is closed.  After a full backoff, drop the connection if
7273 	 * the idle time (no responses to probes) reaches the maximum
7274 	 * backoff that we would use if retransmitting.
7275 	 */
7276 	if (tp->t_rxtshift >= V_tcp_retries &&
7277 	    (ticks - tp->t_rcvtime >= tcp_maxpersistidle ||
7278 	     TICKS_2_USEC(ticks - tp->t_rcvtime) >= RACK_REXMTVAL(tp) * tcp_totbackoff)) {
7279 		KMOD_TCPSTAT_INC(tcps_persistdrop);
7280 		tcp_log_end_status(tp, TCP_EI_STATUS_PERSIST_MAX);
7281 		counter_u64_add(rack_persists_lost_ends, rack->r_ctl.persist_lost_ends);
7282 		retval = -ETIMEDOUT;	/* tcp_drop() */
7283 		goto out;
7284 	}
7285 	if ((sbavail(&rack->rc_inp->inp_socket->so_snd) == 0) &&
7286 	    tp->snd_una == tp->snd_max)
7287 		rack_exit_persist(tp, rack, cts);
7288 	rack->r_ctl.rc_hpts_flags &= ~PACE_TMR_PERSIT;
7289 	/*
7290 	 * If the user has closed the socket then drop a persisting
7291 	 * connection after a much reduced timeout.
7292 	 */
7293 	if (tp->t_state > TCPS_CLOSE_WAIT &&
7294 	    (ticks - tp->t_rcvtime) >= TCPTV_PERSMAX) {
7295 		KMOD_TCPSTAT_INC(tcps_persistdrop);
7296 		tcp_log_end_status(tp, TCP_EI_STATUS_PERSIST_MAX);
7297 		counter_u64_add(rack_persists_lost_ends, rack->r_ctl.persist_lost_ends);
7298 		retval = -ETIMEDOUT;	/* tcp_drop() */
7299 		goto out;
7300 	}
7301 	if (rack_send_ack_challange(rack)) {
7302 		/* only set it if we were answered */
7303 		if (rack->probe_not_answered) {
7304 			counter_u64_add(rack_persists_loss, 1);
7305 			rack->r_ctl.persist_lost_ends++;
7306 		}
7307 		counter_u64_add(rack_persists_sends, 1);
7308 		counter_u64_add(rack_out_size[TCP_MSS_ACCT_PERSIST], 1);
7309 	}
7310 	if (tp->t_rxtshift < V_tcp_retries)
7311 		tp->t_rxtshift++;
7312 out:
7313 	rack_log_to_event(rack, RACK_TO_FRM_PERSIST, NULL);
7314 	rack_start_hpts_timer(rack, tp, cts,
7315 			      0, 0, 0);
7316 	return (retval);
7317 }
7318 
7319 /*
7320  * If a keepalive goes off, we had no other timers
7321  * happening. We always return 1 here since this
7322  * routine either drops the connection or sends
7323  * out a segment with respond.
7324  */
7325 static int
7326 rack_timeout_keepalive(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cts)
7327 {
7328 	struct inpcb *inp = tptoinpcb(tp);
7329 
7330 	rack->r_ctl.rc_hpts_flags &= ~PACE_TMR_KEEP;
7331 	rack_log_to_event(rack, RACK_TO_FRM_KEEP, NULL);
7332 	/*
7333 	 * Keep-alive timer went off; send something or drop connection if
7334 	 * idle for too long.
7335 	 */
7336 	KMOD_TCPSTAT_INC(tcps_keeptimeo);
7337 	if (tp->t_state < TCPS_ESTABLISHED)
7338 		goto dropit;
7339 	if ((V_tcp_always_keepalive || inp->inp_socket->so_options & SO_KEEPALIVE) &&
7340 	    tp->t_state <= TCPS_CLOSING) {
7341 		if (ticks - tp->t_rcvtime >= TP_KEEPIDLE(tp) + TP_MAXIDLE(tp))
7342 			goto dropit;
7343 		/*
7344 		 * Send a packet designed to force a response if the peer is
7345 		 * up and reachable: either an ACK if the connection is
7346 		 * still alive, or an RST if the peer has closed the
7347 		 * connection due to timeout or reboot. Using sequence
7348 		 * number tp->snd_una-1 causes the transmitted zero-length
7349 		 * segment to lie outside the receive window; by the
7350 		 * protocol spec, this requires the correspondent TCP to
7351 		 * respond.
7352 		 */
7353 		KMOD_TCPSTAT_INC(tcps_keepprobe);
7354 		rack_send_ack_challange(rack);
7355 	}
7356 	rack_start_hpts_timer(rack, tp, cts, 0, 0, 0);
7357 	return (1);
7358 dropit:
7359 	KMOD_TCPSTAT_INC(tcps_keepdrops);
7360 	tcp_log_end_status(tp, TCP_EI_STATUS_KEEP_MAX);
7361 	return (-ETIMEDOUT);	/* tcp_drop() */
7362 }
7363 
7364 /*
7365  * Retransmit helper function, clear up all the ack
7366  * flags and take care of important book keeping.
7367  */
7368 static void
7369 rack_remxt_tmr(struct tcpcb *tp)
7370 {
7371 	/*
7372 	 * The retransmit timer went off, all sack'd blocks must be
7373 	 * un-acked.
7374 	 */
7375 	struct rack_sendmap *rsm, *trsm = NULL;
7376 	struct tcp_rack *rack;
7377 
7378 	rack = (struct tcp_rack *)tp->t_fb_ptr;
7379 	rack_timer_cancel(tp, rack, tcp_get_usecs(NULL), __LINE__);
7380 	rack_log_to_event(rack, RACK_TO_FRM_TMR, NULL);
7381 	rack->r_timer_override = 1;
7382 	rack->r_ctl.rc_snd_max_at_rto = tp->snd_max;
7383 	rack->r_ctl.rc_last_timeout_snduna = tp->snd_una;
7384 	rack->r_late = 0;
7385 	rack->r_early = 0;
7386 	rack->r_ctl.rc_agg_delayed = 0;
7387 	rack->r_ctl.rc_agg_early = 0;
7388 	if (rack->r_state && (rack->r_state != tp->t_state))
7389 		rack_set_state(tp, rack);
7390 	if (tp->t_rxtshift <= rack_rxt_scoreboard_clear_thresh) {
7391 		/*
7392 		 * We do not clear the scoreboard until we have had
7393 		 * more than rack_rxt_scoreboard_clear_thresh time-outs.
7394 		 */
7395 		rack->r_ctl.rc_resend = TAILQ_FIRST(&rack->r_ctl.rc_tmap);
7396 		if (rack->r_ctl.rc_resend != NULL)
7397 			rack->r_ctl.rc_resend->r_flags |= RACK_TO_REXT;
7398 
7399 		return;
7400 	}
7401 	/*
7402 	 * Ideally we would like to be able to
7403 	 * mark SACK-PASS on anything not acked here.
7404 	 *
7405 	 * However, if we do that we would burst out
7406 	 * all that data 1ms apart. This would be unwise,
7407 	 * so for now we will just let the normal rxt timer
7408 	 * and tlp timer take care of it.
7409 	 *
7410 	 * Also we really need to stick them back in sequence
7411 	 * order. This way we send in the proper order and any
7412 	 * sacks that come floating in will "re-ack" the data.
7413 	 * To do this we zap the tmap with an INIT and then
7414 	 * walk through and place every rsm in the tail queue
7415 	 * hash table back in its seq ordered place.
7416 	 */
7417 	TAILQ_INIT(&rack->r_ctl.rc_tmap);
7418 
7419 	TQHASH_FOREACH(rsm, rack->r_ctl.tqh)  {
7420 		rsm->r_dupack = 0;
7421 		if (rack_verbose_logging)
7422 			rack_log_retran_reason(rack, rsm, __LINE__, 0, 2);
7423 		/* We must re-add it back to the tlist */
7424 		if (trsm == NULL) {
7425 			TAILQ_INSERT_HEAD(&rack->r_ctl.rc_tmap, rsm, r_tnext);
7426 		} else {
7427 			TAILQ_INSERT_AFTER(&rack->r_ctl.rc_tmap, trsm, rsm, r_tnext);
7428 		}
7429 		rsm->r_in_tmap = 1;
7430 		trsm = rsm;
7431 		if (rsm->r_flags & RACK_ACKED)
7432 			rsm->r_flags |= RACK_WAS_ACKED;
7433 		rsm->r_flags &= ~(RACK_ACKED | RACK_SACK_PASSED | RACK_WAS_SACKPASS | RACK_RWND_COLLAPSED | RACK_WAS_LOST);
7434 		rsm->r_flags |= RACK_MUST_RXT;
7435 	}
7436 	/* zero the lost since it's all gone */
7437 	rack->r_ctl.rc_considered_lost = 0;
7438 	/* Clear the count (we just un-acked them) */
7439 	rack->r_ctl.rc_sacked = 0;
7440 	rack->r_ctl.rc_sacklast = NULL;
7441 	/* Clear the tlp rtx mark */
7442 	rack->r_ctl.rc_resend = tqhash_min(rack->r_ctl.tqh);
7443 	if (rack->r_ctl.rc_resend != NULL)
7444 		rack->r_ctl.rc_resend->r_flags |= RACK_TO_REXT;
7445 	rack->r_ctl.rc_prr_sndcnt = 0;
7446 	rack_log_to_prr(rack, 6, 0, __LINE__);
7447 	rack->r_ctl.rc_resend = tqhash_min(rack->r_ctl.tqh);
7448 	if (rack->r_ctl.rc_resend != NULL)
7449 		rack->r_ctl.rc_resend->r_flags |= RACK_TO_REXT;
7450 	if (((tp->t_flags & TF_SACK_PERMIT) == 0) &&
7451 	    ((tp->t_flags & TF_SENTFIN) == 0)) {
7452 		/*
7453 		 * For non-sack customers new data
7454 		 * needs to go out as retransmits until
7455 		 * we retransmit up to snd_max.
7456 		 */
7457 		rack->r_must_retran = 1;
7458 		rack->r_ctl.rc_out_at_rto = ctf_flight_size(rack->rc_tp,
7459 							    rack->r_ctl.rc_sacked);
7460 	}
7461 }
7462 
7463 static void
7464 rack_convert_rtts(struct tcpcb *tp)
7465 {
7466 	tcp_change_time_units(tp, TCP_TMR_GRANULARITY_USEC);
7467 	tp->t_rxtcur = RACK_REXMTVAL(tp);
7468 	if (TCPS_HAVEESTABLISHED(tp->t_state)) {
7469 		tp->t_rxtcur += TICKS_2_USEC(tcp_rexmit_slop);
7470 	}
7471 	if (tp->t_rxtcur > rack_rto_max) {
7472 		tp->t_rxtcur = rack_rto_max;
7473 	}
7474 }
7475 
7476 static void
7477 rack_cc_conn_init(struct tcpcb *tp)
7478 {
7479 	struct tcp_rack *rack;
7480 	uint32_t srtt;
7481 
7482 	rack = (struct tcp_rack *)tp->t_fb_ptr;
7483 	srtt = tp->t_srtt;
7484 	cc_conn_init(tp);
7485 	/*
7486 	 * Now convert to rack's internal format,
7487 	 * if required.
7488 	 */
7489 	if ((srtt == 0) && (tp->t_srtt != 0))
7490 		rack_convert_rtts(tp);
7491 	/*
7492 	 * We want a chance to stay in slowstart as
7493 	 * we create a connection. TCP spec says that
7494 	 * initially ssthresh is infinite. For our
7495 	 * purposes that is the snd_wnd.
7496 	 */
7497 	if (tp->snd_ssthresh < tp->snd_wnd) {
7498 		tp->snd_ssthresh = tp->snd_wnd;
7499 	}
7500 	/*
7501 	 * We also want to assure a IW worth of
7502 	 * data can get inflight.
7503 	 */
7504 	if (rc_init_window(rack) < tp->snd_cwnd)
7505 		tp->snd_cwnd = rc_init_window(rack);
7506 }
7507 
7508 /*
7509  * Re-transmit timeout! If we drop the PCB we will return 1, otherwise
7510  * we will setup to retransmit the lowest seq number outstanding.
7511  */
7512 static int
7513 rack_timeout_rxt(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cts)
7514 {
7515 	struct inpcb *inp = tptoinpcb(tp);
7516 	int32_t rexmt;
7517 	int32_t retval = 0;
7518 	bool isipv6;
7519 
7520 	if ((tp->t_flags & TF_GPUTINPROG) &&
7521 	    (tp->t_rxtshift)) {
7522 		/*
7523 		 * We have had a second timeout
7524 		 * measurements on successive rxt's are not profitable.
7525 		 * It is unlikely to be of any use (the network is
7526 		 * broken or the client went away).
7527 		 */
7528 		tp->t_flags &= ~TF_GPUTINPROG;
7529 		rack_log_pacing_delay_calc(rack, (tp->gput_ack - tp->gput_seq) /*flex2*/,
7530 					   rack->r_ctl.rc_gp_srtt /*flex1*/,
7531 					   tp->gput_seq,
7532 					   0, 0, 18, __LINE__, NULL, 0);
7533 	}
7534 	if (ctf_progress_timeout_check(tp, false)) {
7535 		tcp_log_end_status(tp, TCP_EI_STATUS_RETRAN);
7536 		rack_log_progress_event(rack, tp, tick, PROGRESS_DROP, __LINE__);
7537 		return (-ETIMEDOUT);	/* tcp_drop() */
7538 	}
7539 	rack->r_ctl.rc_hpts_flags &= ~PACE_TMR_RXT;
7540 	rack->r_ctl.retran_during_recovery = 0;
7541 	rack->rc_ack_required = 1;
7542 	rack->r_ctl.dsack_byte_cnt = 0;
7543 	if (IN_RECOVERY(tp->t_flags) &&
7544 	    (rack->rto_from_rec == 0)) {
7545 		/*
7546 		 * Mark that we had a rto while in recovery
7547 		 * and save the ssthresh so if we go back
7548 		 * into recovery we will have a chance
7549 		 * to slowstart back to the level.
7550 		 */
7551 		rack->rto_from_rec = 1;
7552 		rack->r_ctl.rto_ssthresh = tp->snd_ssthresh;
7553 	}
7554 	if (IN_FASTRECOVERY(tp->t_flags))
7555 		tp->t_flags |= TF_WASFRECOVERY;
7556 	else
7557 		tp->t_flags &= ~TF_WASFRECOVERY;
7558 	if (IN_CONGRECOVERY(tp->t_flags))
7559 		tp->t_flags |= TF_WASCRECOVERY;
7560 	else
7561 		tp->t_flags &= ~TF_WASCRECOVERY;
7562 	if (TCPS_HAVEESTABLISHED(tp->t_state) &&
7563 	    (tp->snd_una == tp->snd_max)) {
7564 		/* Nothing outstanding .. nothing to do */
7565 		return (0);
7566 	}
7567 	if (rack->r_ctl.dsack_persist) {
7568 		rack->r_ctl.dsack_persist--;
7569 		if (rack->r_ctl.num_dsack && (rack->r_ctl.dsack_persist == 0)) {
7570 			rack->r_ctl.num_dsack = 0;
7571 		}
7572 		rack_log_dsack_event(rack, 1, __LINE__, 0, 0);
7573 	}
7574 	/*
7575 	 * Rack can only run one timer  at a time, so we cannot
7576 	 * run a KEEPINIT (gating SYN sending) and a retransmit
7577 	 * timer for the SYN. So if we are in a front state and
7578 	 * have a KEEPINIT timer we need to check the first transmit
7579 	 * against now to see if we have exceeded the KEEPINIT time
7580 	 * (if one is set).
7581 	 */
7582 	if ((TCPS_HAVEESTABLISHED(tp->t_state) == 0) &&
7583 	    (TP_KEEPINIT(tp) != 0)) {
7584 		struct rack_sendmap *rsm;
7585 
7586 		rsm = tqhash_min(rack->r_ctl.tqh);
7587 		if (rsm) {
7588 			/* Ok we have something outstanding to test keepinit with */
7589 			if ((TSTMP_GT(cts, (uint32_t)rsm->r_tim_lastsent[0])) &&
7590 			    ((cts - (uint32_t)rsm->r_tim_lastsent[0]) >= TICKS_2_USEC(TP_KEEPINIT(tp)))) {
7591 				/* We have exceeded the KEEPINIT time */
7592 				tcp_log_end_status(tp, TCP_EI_STATUS_KEEP_MAX);
7593 				goto drop_it;
7594 			}
7595 		}
7596 	}
7597 	/*
7598 	 * Retransmission timer went off.  Message has not been acked within
7599 	 * retransmit interval.  Back off to a longer retransmit interval
7600 	 * and retransmit one segment.
7601 	 */
7602 	if ((rack->r_ctl.rc_resend == NULL) ||
7603 	    ((rack->r_ctl.rc_resend->r_flags & RACK_RWND_COLLAPSED) == 0)) {
7604 		/*
7605 		 * If the rwnd collapsed on
7606 		 * the one we are retransmitting
7607 		 * it does not count against the
7608 		 * rxt count.
7609 		 */
7610 		tp->t_rxtshift++;
7611 	}
7612 	rack_remxt_tmr(tp);
7613 	if (tp->t_rxtshift > V_tcp_retries) {
7614 		tcp_log_end_status(tp, TCP_EI_STATUS_RETRAN);
7615 drop_it:
7616 		tp->t_rxtshift = V_tcp_retries;
7617 		KMOD_TCPSTAT_INC(tcps_timeoutdrop);
7618 		/* XXXGL: previously t_softerror was casted to uint16_t */
7619 		MPASS(tp->t_softerror >= 0);
7620 		retval = tp->t_softerror ? -tp->t_softerror : -ETIMEDOUT;
7621 		goto out;	/* tcp_drop() */
7622 	}
7623 	if (tp->t_state == TCPS_SYN_SENT) {
7624 		/*
7625 		 * If the SYN was retransmitted, indicate CWND to be limited
7626 		 * to 1 segment in cc_conn_init().
7627 		 */
7628 		tp->snd_cwnd = 1;
7629 	} else if (tp->t_rxtshift == 1) {
7630 		/*
7631 		 * first retransmit; record ssthresh and cwnd so they can be
7632 		 * recovered if this turns out to be a "bad" retransmit. A
7633 		 * retransmit is considered "bad" if an ACK for this segment
7634 		 * is received within RTT/2 interval; the assumption here is
7635 		 * that the ACK was already in flight.  See "On Estimating
7636 		 * End-to-End Network Path Properties" by Allman and Paxson
7637 		 * for more details.
7638 		 */
7639 		tp->snd_cwnd_prev = tp->snd_cwnd;
7640 		tp->snd_ssthresh_prev = tp->snd_ssthresh;
7641 		tp->snd_recover_prev = tp->snd_recover;
7642 		tp->t_badrxtwin = ticks + (USEC_2_TICKS(tp->t_srtt)/2);
7643 		tp->t_flags |= TF_PREVVALID;
7644 	} else if ((tp->t_flags & TF_RCVD_TSTMP) == 0)
7645 		tp->t_flags &= ~TF_PREVVALID;
7646 	KMOD_TCPSTAT_INC(tcps_rexmttimeo);
7647 	if ((tp->t_state == TCPS_SYN_SENT) ||
7648 	    (tp->t_state == TCPS_SYN_RECEIVED))
7649 		rexmt = RACK_INITIAL_RTO * tcp_backoff[tp->t_rxtshift];
7650 	else
7651 		rexmt = max(rack_rto_min, (tp->t_srtt + (tp->t_rttvar << 2))) * tcp_backoff[tp->t_rxtshift];
7652 
7653 	RACK_TCPT_RANGESET(tp->t_rxtcur, rexmt,
7654 	   max(rack_rto_min, rexmt), rack_rto_max, rack->r_ctl.timer_slop);
7655 	/*
7656 	 * We enter the path for PLMTUD if connection is established or, if
7657 	 * connection is FIN_WAIT_1 status, reason for the last is that if
7658 	 * amount of data we send is very small, we could send it in couple
7659 	 * of packets and process straight to FIN. In that case we won't
7660 	 * catch ESTABLISHED state.
7661 	 */
7662 #ifdef INET6
7663 	isipv6 = (inp->inp_vflag & INP_IPV6) ? true : false;
7664 #else
7665 	isipv6 = false;
7666 #endif
7667 	if (((V_tcp_pmtud_blackhole_detect == 1) ||
7668 	    (V_tcp_pmtud_blackhole_detect == 2 && !isipv6) ||
7669 	    (V_tcp_pmtud_blackhole_detect == 3 && isipv6)) &&
7670 	    ((tp->t_state == TCPS_ESTABLISHED) ||
7671 	    (tp->t_state == TCPS_FIN_WAIT_1))) {
7672 		/*
7673 		 * Idea here is that at each stage of mtu probe (usually,
7674 		 * 1448 -> 1188 -> 524) should be given 2 chances to recover
7675 		 * before further clamping down. 'tp->t_rxtshift % 2 == 0'
7676 		 * should take care of that.
7677 		 */
7678 		if (((tp->t_flags2 & (TF2_PLPMTU_PMTUD | TF2_PLPMTU_MAXSEGSNT)) ==
7679 		    (TF2_PLPMTU_PMTUD | TF2_PLPMTU_MAXSEGSNT)) &&
7680 		    (tp->t_rxtshift >= 2 && tp->t_rxtshift < 6 &&
7681 		    tp->t_rxtshift % 2 == 0)) {
7682 			/*
7683 			 * Enter Path MTU Black-hole Detection mechanism: -
7684 			 * Disable Path MTU Discovery (IP "DF" bit). -
7685 			 * Reduce MTU to lower value than what we negotiated
7686 			 * with peer.
7687 			 */
7688 			if ((tp->t_flags2 & TF2_PLPMTU_BLACKHOLE) == 0) {
7689 				/* Record that we may have found a black hole. */
7690 				tp->t_flags2 |= TF2_PLPMTU_BLACKHOLE;
7691 				/* Keep track of previous MSS. */
7692 				tp->t_pmtud_saved_maxseg = tp->t_maxseg;
7693 			}
7694 
7695 			/*
7696 			 * Reduce the MSS to blackhole value or to the
7697 			 * default in an attempt to retransmit.
7698 			 */
7699 #ifdef INET6
7700 			if (isipv6 &&
7701 			    tp->t_maxseg > V_tcp_v6pmtud_blackhole_mss) {
7702 				/* Use the sysctl tuneable blackhole MSS. */
7703 				tp->t_maxseg = V_tcp_v6pmtud_blackhole_mss;
7704 				KMOD_TCPSTAT_INC(tcps_pmtud_blackhole_activated);
7705 			} else if (isipv6) {
7706 				/* Use the default MSS. */
7707 				tp->t_maxseg = V_tcp_v6mssdflt;
7708 				/*
7709 				 * Disable Path MTU Discovery when we switch
7710 				 * to minmss.
7711 				 */
7712 				tp->t_flags2 &= ~TF2_PLPMTU_PMTUD;
7713 				KMOD_TCPSTAT_INC(tcps_pmtud_blackhole_activated_min_mss);
7714 			}
7715 #endif
7716 #if defined(INET6) && defined(INET)
7717 			else
7718 #endif
7719 #ifdef INET
7720 			if (tp->t_maxseg > V_tcp_pmtud_blackhole_mss) {
7721 				/* Use the sysctl tuneable blackhole MSS. */
7722 				tp->t_maxseg = V_tcp_pmtud_blackhole_mss;
7723 				KMOD_TCPSTAT_INC(tcps_pmtud_blackhole_activated);
7724 			} else {
7725 				/* Use the default MSS. */
7726 				tp->t_maxseg = V_tcp_mssdflt;
7727 				/*
7728 				 * Disable Path MTU Discovery when we switch
7729 				 * to minmss.
7730 				 */
7731 				tp->t_flags2 &= ~TF2_PLPMTU_PMTUD;
7732 				KMOD_TCPSTAT_INC(tcps_pmtud_blackhole_activated_min_mss);
7733 			}
7734 #endif
7735 		} else {
7736 			/*
7737 			 * If further retransmissions are still unsuccessful
7738 			 * with a lowered MTU, maybe this isn't a blackhole
7739 			 * and we restore the previous MSS and blackhole
7740 			 * detection flags. The limit '6' is determined by
7741 			 * giving each probe stage (1448, 1188, 524) 2
7742 			 * chances to recover.
7743 			 */
7744 			if ((tp->t_flags2 & TF2_PLPMTU_BLACKHOLE) &&
7745 			    (tp->t_rxtshift >= 6)) {
7746 				tp->t_flags2 |= TF2_PLPMTU_PMTUD;
7747 				tp->t_flags2 &= ~TF2_PLPMTU_BLACKHOLE;
7748 				tp->t_maxseg = tp->t_pmtud_saved_maxseg;
7749 				if (tp->t_maxseg < V_tcp_mssdflt) {
7750 					/*
7751 					 * The MSS is so small we should not
7752 					 * process incoming SACK's since we are
7753 					 * subject to attack in such a case.
7754 					 */
7755 					tp->t_flags2 |= TF2_PROC_SACK_PROHIBIT;
7756 				} else {
7757 					tp->t_flags2 &= ~TF2_PROC_SACK_PROHIBIT;
7758 				}
7759 				KMOD_TCPSTAT_INC(tcps_pmtud_blackhole_failed);
7760 			}
7761 		}
7762 	}
7763 	/*
7764 	 * Disable RFC1323 and SACK if we haven't got any response to
7765 	 * our third SYN to work-around some broken terminal servers
7766 	 * (most of which have hopefully been retired) that have bad VJ
7767 	 * header compression code which trashes TCP segments containing
7768 	 * unknown-to-them TCP options.
7769 	 */
7770 	if (tcp_rexmit_drop_options && (tp->t_state == TCPS_SYN_SENT) &&
7771 	    (tp->t_rxtshift == 3))
7772 		tp->t_flags &= ~(TF_REQ_SCALE|TF_REQ_TSTMP|TF_SACK_PERMIT);
7773 	/*
7774 	 * If we backed off this far, our srtt estimate is probably bogus.
7775 	 * Clobber it so we'll take the next rtt measurement as our srtt;
7776 	 * move the current srtt into rttvar to keep the current retransmit
7777 	 * times until then.
7778 	 */
7779 	if (tp->t_rxtshift > TCP_MAXRXTSHIFT / 4) {
7780 #ifdef INET6
7781 		if ((inp->inp_vflag & INP_IPV6) != 0)
7782 			in6_losing(inp);
7783 		else
7784 #endif
7785 			in_losing(inp);
7786 		tp->t_rttvar += tp->t_srtt;
7787 		tp->t_srtt = 0;
7788 	}
7789 	sack_filter_clear(&rack->r_ctl.rack_sf, tp->snd_una);
7790 	tp->snd_recover = tp->snd_max;
7791 	tp->t_flags |= TF_ACKNOW;
7792 	tp->t_rtttime = 0;
7793 	rack_cong_signal(tp, CC_RTO, tp->snd_una, __LINE__);
7794 out:
7795 	return (retval);
7796 }
7797 
7798 static int
7799 rack_process_timers(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cts, uint8_t hpts_calling, uint8_t *doing_tlp)
7800 {
7801 	int32_t ret = 0;
7802 	int32_t timers = (rack->r_ctl.rc_hpts_flags & PACE_TMR_MASK);
7803 
7804 	if ((tp->t_state >= TCPS_FIN_WAIT_1) &&
7805 	    (tp->t_flags & TF_GPUTINPROG)) {
7806 		/*
7807 		 * We have a goodput in progress
7808 		 * and we have entered a late state.
7809 		 * Do we have enough data in the sb
7810 		 * to handle the GPUT request?
7811 		 */
7812 		uint32_t bytes;
7813 
7814 		bytes = tp->gput_ack - tp->gput_seq;
7815 		if (SEQ_GT(tp->gput_seq, tp->snd_una))
7816 			bytes += tp->gput_seq - tp->snd_una;
7817 		if (bytes > sbavail(&tptosocket(tp)->so_snd)) {
7818 			/*
7819 			 * There are not enough bytes in the socket
7820 			 * buffer that have been sent to cover this
7821 			 * measurement. Cancel it.
7822 			 */
7823 			rack_log_pacing_delay_calc(rack, (tp->gput_ack - tp->gput_seq) /*flex2*/,
7824 						   rack->r_ctl.rc_gp_srtt /*flex1*/,
7825 						   tp->gput_seq,
7826 						   0, 0, 18, __LINE__, NULL, 0);
7827 			tp->t_flags &= ~TF_GPUTINPROG;
7828 		}
7829 	}
7830 	if (timers == 0) {
7831 		return (0);
7832 	}
7833 	if (tp->t_state == TCPS_LISTEN) {
7834 		/* no timers on listen sockets */
7835 		if (rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT)
7836 			return (0);
7837 		return (1);
7838 	}
7839 	if ((timers & PACE_TMR_RACK) &&
7840 	    rack->rc_on_min_to) {
7841 		/*
7842 		 * For the rack timer when we
7843 		 * are on a min-timeout (which means rrr_conf = 3)
7844 		 * we don't want to check the timer. It may
7845 		 * be going off for a pace and thats ok we
7846 		 * want to send the retransmit (if its ready).
7847 		 *
7848 		 * If its on a normal rack timer (non-min) then
7849 		 * we will check if its expired.
7850 		 */
7851 		goto skip_time_check;
7852 	}
7853 	if (TSTMP_LT(cts, rack->r_ctl.rc_timer_exp)) {
7854 		uint32_t left;
7855 
7856 		if (rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT) {
7857 			ret = -1;
7858 			rack_log_to_processing(rack, cts, ret, 0);
7859 			return (0);
7860 		}
7861 		if (hpts_calling == 0) {
7862 			/*
7863 			 * A user send or queued mbuf (sack) has called us? We
7864 			 * return 0 and let the pacing guards
7865 			 * deal with it if they should or
7866 			 * should not cause a send.
7867 			 */
7868 			ret = -2;
7869 			rack_log_to_processing(rack, cts, ret, 0);
7870 			return (0);
7871 		}
7872 		/*
7873 		 * Ok our timer went off early and we are not paced false
7874 		 * alarm, go back to sleep. We make sure we don't have
7875 		 * no-sack wakeup on since we no longer have a PKT_OUTPUT
7876 		 * flag in place.
7877 		 */
7878 		rack->rc_tp->t_flags2 &= ~TF2_DONT_SACK_QUEUE;
7879 		ret = -3;
7880 		left = rack->r_ctl.rc_timer_exp - cts;
7881 		tcp_hpts_insert(tp, left, NULL);
7882 		rack_log_to_processing(rack, cts, ret, left);
7883 		return (1);
7884 	}
7885 skip_time_check:
7886 	rack->rc_tmr_stopped = 0;
7887 	rack->r_ctl.rc_hpts_flags &= ~PACE_TMR_MASK;
7888 	if (timers & PACE_TMR_DELACK) {
7889 		ret = rack_timeout_delack(tp, rack, cts);
7890 	} else if (timers & PACE_TMR_RACK) {
7891 		rack->r_ctl.rc_tlp_rxt_last_time = cts;
7892 		rack->r_fast_output = 0;
7893 		ret = rack_timeout_rack(tp, rack, cts);
7894 	} else if (timers & PACE_TMR_TLP) {
7895 		rack->r_ctl.rc_tlp_rxt_last_time = cts;
7896 		rack->r_fast_output = 0;
7897 		ret = rack_timeout_tlp(tp, rack, cts, doing_tlp);
7898 	} else if (timers & PACE_TMR_RXT) {
7899 		rack->r_ctl.rc_tlp_rxt_last_time = cts;
7900 		rack->r_fast_output = 0;
7901 		ret = rack_timeout_rxt(tp, rack, cts);
7902 	} else if (timers & PACE_TMR_PERSIT) {
7903 		ret = rack_timeout_persist(tp, rack, cts);
7904 	} else if (timers & PACE_TMR_KEEP) {
7905 		ret = rack_timeout_keepalive(tp, rack, cts);
7906 	}
7907 	rack_log_to_processing(rack, cts, ret, timers);
7908 	return (ret);
7909 }
7910 
7911 static void
7912 rack_timer_cancel(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cts, int line)
7913 {
7914 	struct timeval tv;
7915 	uint32_t us_cts, flags_on_entry;
7916 	uint8_t hpts_removed = 0;
7917 
7918 	flags_on_entry = rack->r_ctl.rc_hpts_flags;
7919 	us_cts = tcp_get_usecs(&tv);
7920 	if ((rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT) &&
7921 	    ((TSTMP_GEQ(us_cts, rack->r_ctl.rc_last_output_to)) ||
7922 	     ((tp->snd_max - tp->snd_una) == 0))) {
7923 		tcp_hpts_remove(rack->rc_tp);
7924 		hpts_removed = 1;
7925 		/* If we were not delayed cancel out the flag. */
7926 		if ((tp->snd_max - tp->snd_una) == 0)
7927 			rack->r_ctl.rc_hpts_flags &= ~PACE_PKT_OUTPUT;
7928 		rack_log_to_cancel(rack, hpts_removed, line, us_cts, &tv, flags_on_entry);
7929 	}
7930 	if (rack->r_ctl.rc_hpts_flags & PACE_TMR_MASK) {
7931 		rack->rc_tmr_stopped = rack->r_ctl.rc_hpts_flags & PACE_TMR_MASK;
7932 		if (tcp_in_hpts(rack->rc_tp) &&
7933 		    ((rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT) == 0)) {
7934 			/*
7935 			 * Canceling timer's when we have no output being
7936 			 * paced. We also must remove ourselves from the
7937 			 * hpts.
7938 			 */
7939 			tcp_hpts_remove(rack->rc_tp);
7940 			hpts_removed = 1;
7941 		}
7942 		rack->r_ctl.rc_hpts_flags &= ~(PACE_TMR_MASK);
7943 	}
7944 	if (hpts_removed == 0)
7945 		rack_log_to_cancel(rack, hpts_removed, line, us_cts, &tv, flags_on_entry);
7946 }
7947 
7948 static int
7949 rack_stopall(struct tcpcb *tp)
7950 {
7951 	struct tcp_rack *rack;
7952 
7953 	rack = (struct tcp_rack *)tp->t_fb_ptr;
7954 	rack->t_timers_stopped = 1;
7955 
7956 	tcp_hpts_remove(tp);
7957 
7958 	return (0);
7959 }
7960 
7961 static void
7962 rack_stop_all_timers(struct tcpcb *tp, struct tcp_rack *rack)
7963 {
7964 	/*
7965 	 * Assure no timers are running.
7966 	 */
7967 	if (tcp_timer_active(tp, TT_PERSIST)) {
7968 		/* We enter in persists, set the flag appropriately */
7969 		rack->rc_in_persist = 1;
7970 	}
7971 	if (tcp_in_hpts(rack->rc_tp)) {
7972 		tcp_hpts_remove(rack->rc_tp);
7973 	}
7974 }
7975 
7976 static void
7977 rack_update_rsm(struct tcpcb *tp, struct tcp_rack *rack,
7978     struct rack_sendmap *rsm, uint64_t ts, uint32_t add_flag, int segsiz)
7979 {
7980 	int32_t idx;
7981 
7982 	rsm->r_rtr_cnt++;
7983 	if (rsm->r_rtr_cnt > RACK_NUM_OF_RETRANS) {
7984 		rsm->r_rtr_cnt = RACK_NUM_OF_RETRANS;
7985 		rsm->r_flags |= RACK_OVERMAX;
7986 	}
7987 	rsm->r_act_rxt_cnt++;
7988 	/* Peg the count/index */
7989 	rack_log_retran_reason(rack, rsm, __LINE__, 0, 2);
7990 	rsm->r_dupack = 0;
7991 	if ((rsm->r_rtr_cnt > 1) && ((rsm->r_flags & RACK_TLP) == 0)) {
7992 		rack->r_ctl.rc_holes_rxt += (rsm->r_end - rsm->r_start);
7993 		rsm->r_rtr_bytes += (rsm->r_end - rsm->r_start);
7994 	}
7995 	if (rsm->r_flags & RACK_WAS_LOST) {
7996 		/*
7997 		 * We retransmitted it putting it back in flight
7998 		 * remove the lost desgination and reduce the
7999 		 * bytes considered lost.
8000 		 */
8001 		rack_mark_nolonger_lost(rack, rsm);
8002 	}
8003 	idx = rsm->r_rtr_cnt - 1;
8004 	rsm->r_tim_lastsent[idx] = ts;
8005 	/*
8006 	 * Here we don't add in the len of send, since its already
8007 	 * in snduna <->snd_max.
8008 	 */
8009 	rsm->r_fas = ctf_flight_size(rack->rc_tp,
8010 				     rack->r_ctl.rc_sacked);
8011 	if (rsm->r_flags & RACK_ACKED) {
8012 		/* Problably MTU discovery messing with us */
8013 		rsm->r_flags &= ~RACK_ACKED;
8014 		rack->r_ctl.rc_sacked -= (rsm->r_end - rsm->r_start);
8015 	}
8016 	if (rsm->r_in_tmap) {
8017 		TAILQ_REMOVE(&rack->r_ctl.rc_tmap, rsm, r_tnext);
8018 		rsm->r_in_tmap = 0;
8019 	}
8020 	/* Lets make sure it really is in or not the GP window */
8021 	rack_mark_in_gp_win(tp, rsm);
8022 	TAILQ_INSERT_TAIL(&rack->r_ctl.rc_tmap, rsm, r_tnext);
8023 	rsm->r_in_tmap = 1;
8024 	rsm->r_bas = (uint8_t)(((rsm->r_end - rsm->r_start) + segsiz - 1) / segsiz);
8025 	/* Take off the must retransmit flag, if its on */
8026 	if (rsm->r_flags & RACK_MUST_RXT) {
8027 		if (rack->r_must_retran)
8028 			rack->r_ctl.rc_out_at_rto -= (rsm->r_end - rsm->r_start);
8029 		if (SEQ_GEQ(rsm->r_end, rack->r_ctl.rc_snd_max_at_rto)) {
8030 			/*
8031 			 * We have retransmitted all we need. Clear
8032 			 * any must retransmit flags.
8033 			 */
8034 			rack->r_must_retran = 0;
8035 			rack->r_ctl.rc_out_at_rto = 0;
8036 		}
8037 		rsm->r_flags &= ~RACK_MUST_RXT;
8038 	}
8039 	/* Remove any collapsed flag */
8040 	rsm->r_flags &= ~RACK_RWND_COLLAPSED;
8041 	if (rsm->r_flags & RACK_SACK_PASSED) {
8042 		/* We have retransmitted due to the SACK pass */
8043 		rsm->r_flags &= ~RACK_SACK_PASSED;
8044 		rsm->r_flags |= RACK_WAS_SACKPASS;
8045 	}
8046 }
8047 
8048 static uint32_t
8049 rack_update_entry(struct tcpcb *tp, struct tcp_rack *rack,
8050     struct rack_sendmap *rsm, uint64_t ts, int32_t *lenp, uint32_t add_flag, int segsiz)
8051 {
8052 	/*
8053 	 * We (re-)transmitted starting at rsm->r_start for some length
8054 	 * (possibly less than r_end.
8055 	 */
8056 	struct rack_sendmap *nrsm;
8057 	int insret __diagused;
8058 	uint32_t c_end;
8059 	int32_t len;
8060 
8061 	len = *lenp;
8062 	c_end = rsm->r_start + len;
8063 	if (SEQ_GEQ(c_end, rsm->r_end)) {
8064 		/*
8065 		 * We retransmitted the whole piece or more than the whole
8066 		 * slopping into the next rsm.
8067 		 */
8068 		rack_update_rsm(tp, rack, rsm, ts, add_flag, segsiz);
8069 		if (c_end == rsm->r_end) {
8070 			*lenp = 0;
8071 			return (0);
8072 		} else {
8073 			int32_t act_len;
8074 
8075 			/* Hangs over the end return whats left */
8076 			act_len = rsm->r_end - rsm->r_start;
8077 			*lenp = (len - act_len);
8078 			return (rsm->r_end);
8079 		}
8080 		/* We don't get out of this block. */
8081 	}
8082 	/*
8083 	 * Here we retransmitted less than the whole thing which means we
8084 	 * have to split this into what was transmitted and what was not.
8085 	 */
8086 	nrsm = rack_alloc_full_limit(rack);
8087 	if (nrsm == NULL) {
8088 		/*
8089 		 * We can't get memory, so lets not proceed.
8090 		 */
8091 		*lenp = 0;
8092 		return (0);
8093 	}
8094 	/*
8095 	 * So here we are going to take the original rsm and make it what we
8096 	 * retransmitted. nrsm will be the tail portion we did not
8097 	 * retransmit. For example say the chunk was 1, 11 (10 bytes). And
8098 	 * we retransmitted 5 bytes i.e. 1, 5. The original piece shrinks to
8099 	 * 1, 6 and the new piece will be 6, 11.
8100 	 */
8101 	rack_clone_rsm(rack, nrsm, rsm, c_end);
8102 	nrsm->r_dupack = 0;
8103 	rack_log_retran_reason(rack, nrsm, __LINE__, 0, 2);
8104 #ifndef INVARIANTS
8105 	(void)tqhash_insert(rack->r_ctl.tqh, nrsm);
8106 #else
8107 	if ((insret = tqhash_insert(rack->r_ctl.tqh, nrsm)) != 0) {
8108 		panic("Insert in tailq_hash of %p fails ret:%d rack:%p rsm:%p",
8109 		      nrsm, insret, rack, rsm);
8110 	}
8111 #endif
8112 	if (rsm->r_in_tmap) {
8113 		TAILQ_INSERT_AFTER(&rack->r_ctl.rc_tmap, rsm, nrsm, r_tnext);
8114 		nrsm->r_in_tmap = 1;
8115 	}
8116 	rsm->r_flags &= (~RACK_HAS_FIN);
8117 	rack_update_rsm(tp, rack, rsm, ts, add_flag, segsiz);
8118 	/* Log a split of rsm into rsm and nrsm */
8119 	rack_log_map_chg(tp, rack, NULL, rsm, nrsm, MAP_SPLIT, 0, __LINE__);
8120 	*lenp = 0;
8121 	return (0);
8122 }
8123 
8124 static void
8125 rack_log_output(struct tcpcb *tp, struct tcpopt *to, int32_t len,
8126 		uint32_t seq_out, uint16_t th_flags, int32_t err, uint64_t cts,
8127 		struct rack_sendmap *hintrsm, uint32_t add_flag, struct mbuf *s_mb,
8128 		uint32_t s_moff, int hw_tls, int segsiz)
8129 {
8130 	struct tcp_rack *rack;
8131 	struct rack_sendmap *rsm, *nrsm;
8132 	int insret __diagused;
8133 
8134 	register uint32_t snd_max, snd_una;
8135 
8136 	/*
8137 	 * Add to the RACK log of packets in flight or retransmitted. If
8138 	 * there is a TS option we will use the TS echoed, if not we will
8139 	 * grab a TS.
8140 	 *
8141 	 * Retransmissions will increment the count and move the ts to its
8142 	 * proper place. Note that if options do not include TS's then we
8143 	 * won't be able to effectively use the ACK for an RTT on a retran.
8144 	 *
8145 	 * Notes about r_start and r_end. Lets consider a send starting at
8146 	 * sequence 1 for 10 bytes. In such an example the r_start would be
8147 	 * 1 (starting sequence) but the r_end would be r_start+len i.e. 11.
8148 	 * This means that r_end is actually the first sequence for the next
8149 	 * slot (11).
8150 	 *
8151 	 */
8152 	/*
8153 	 * If err is set what do we do XXXrrs? should we not add the thing?
8154 	 * -- i.e. return if err != 0 or should we pretend we sent it? --
8155 	 * i.e. proceed with add ** do this for now.
8156 	 */
8157 	INP_WLOCK_ASSERT(tptoinpcb(tp));
8158 	if (err)
8159 		/*
8160 		 * We don't log errors -- we could but snd_max does not
8161 		 * advance in this case either.
8162 		 */
8163 		return;
8164 
8165 	if (th_flags & TH_RST) {
8166 		/*
8167 		 * We don't log resets and we return immediately from
8168 		 * sending
8169 		 */
8170 		return;
8171 	}
8172 	rack = (struct tcp_rack *)tp->t_fb_ptr;
8173 	snd_una = tp->snd_una;
8174 	snd_max = tp->snd_max;
8175 	if (th_flags & (TH_SYN | TH_FIN)) {
8176 		/*
8177 		 * The call to rack_log_output is made before bumping
8178 		 * snd_max. This means we can record one extra byte on a SYN
8179 		 * or FIN if seq_out is adding more on and a FIN is present
8180 		 * (and we are not resending).
8181 		 */
8182 		if ((th_flags & TH_SYN) && (seq_out == tp->iss))
8183 			len++;
8184 		if (th_flags & TH_FIN)
8185 			len++;
8186 	}
8187 	if (SEQ_LEQ((seq_out + len), snd_una)) {
8188 		/* Are sending an old segment to induce an ack (keep-alive)? */
8189 		return;
8190 	}
8191 	if (SEQ_LT(seq_out, snd_una)) {
8192 		/* huh? should we panic? */
8193 		uint32_t end;
8194 
8195 		end = seq_out + len;
8196 		seq_out = snd_una;
8197 		if (SEQ_GEQ(end, seq_out))
8198 			len = end - seq_out;
8199 		else
8200 			len = 0;
8201 	}
8202 	if (len == 0) {
8203 		/* We don't log zero window probes */
8204 		return;
8205 	}
8206 	if (IN_FASTRECOVERY(tp->t_flags)) {
8207 		rack->r_ctl.rc_prr_out += len;
8208 	}
8209 	/* First question is it a retransmission or new? */
8210 	if (seq_out == snd_max) {
8211 		/* Its new */
8212 		rack_chk_req_and_hybrid_on_out(rack, seq_out, len, cts);
8213 again:
8214 		rsm = rack_alloc(rack);
8215 		if (rsm == NULL) {
8216 			/*
8217 			 * Hmm out of memory and the tcb got destroyed while
8218 			 * we tried to wait.
8219 			 */
8220 			return;
8221 		}
8222 		if (th_flags & TH_FIN) {
8223 			rsm->r_flags = RACK_HAS_FIN|add_flag;
8224 		} else {
8225 			rsm->r_flags = add_flag;
8226 		}
8227 		if (hw_tls)
8228 			rsm->r_hw_tls = 1;
8229 		rsm->r_tim_lastsent[0] = cts;
8230 		rsm->r_rtr_cnt = 1;
8231  		rsm->r_act_rxt_cnt = 0;
8232 		rsm->r_rtr_bytes = 0;
8233 		if (th_flags & TH_SYN) {
8234 			/* The data space is one beyond snd_una */
8235 			rsm->r_flags |= RACK_HAS_SYN;
8236 		}
8237 		rsm->r_start = seq_out;
8238 		rsm->r_end = rsm->r_start + len;
8239 		rack_mark_in_gp_win(tp, rsm);
8240 		rsm->r_dupack = 0;
8241 		/*
8242 		 * save off the mbuf location that
8243 		 * sndmbuf_noadv returned (which is
8244 		 * where we started copying from)..
8245 		 */
8246 		rsm->m = s_mb;
8247 		rsm->soff = s_moff;
8248 		/*
8249 		 * Here we do add in the len of send, since its not yet
8250 		 * reflected in in snduna <->snd_max
8251 		 */
8252 		rsm->r_fas = (ctf_flight_size(rack->rc_tp,
8253 					      rack->r_ctl.rc_sacked) +
8254 			      (rsm->r_end - rsm->r_start));
8255 		if ((rack->rc_initial_ss_comp == 0) &&
8256 		    (rack->r_ctl.ss_hi_fs < rsm->r_fas)) {
8257 			   rack->r_ctl.ss_hi_fs = rsm->r_fas;
8258 		}
8259 		/* rsm->m will be NULL if RACK_HAS_SYN or RACK_HAS_FIN is set */
8260 		if (rsm->m) {
8261 			if (rsm->m->m_len <= rsm->soff) {
8262 				/*
8263 				 * XXXrrs Question, will this happen?
8264 				 *
8265 				 * If sbsndptr is set at the correct place
8266 				 * then s_moff should always be somewhere
8267 				 * within rsm->m. But if the sbsndptr was
8268 				 * off then that won't be true. If it occurs
8269 				 * we need to walkout to the correct location.
8270 				 */
8271 				struct mbuf *lm;
8272 
8273 				lm = rsm->m;
8274 				while (lm->m_len <= rsm->soff) {
8275 					rsm->soff -= lm->m_len;
8276 					lm = lm->m_next;
8277 					KASSERT(lm != NULL, ("%s rack:%p lm goes null orig_off:%u origmb:%p rsm->soff:%u",
8278 							     __func__, rack, s_moff, s_mb, rsm->soff));
8279 				}
8280 				rsm->m = lm;
8281 			}
8282 			rsm->orig_m_len = rsm->m->m_len;
8283 			rsm->orig_t_space = M_TRAILINGROOM(rsm->m);
8284 		} else {
8285 			rsm->orig_m_len = 0;
8286 			rsm->orig_t_space = 0;
8287 		}
8288 		rsm->r_bas = (uint8_t)((len + segsiz - 1) / segsiz);
8289 		rack_log_retran_reason(rack, rsm, __LINE__, 0, 2);
8290 		/* Log a new rsm */
8291 		rack_log_map_chg(tp, rack, NULL, rsm, NULL, MAP_NEW, 0, __LINE__);
8292 #ifndef INVARIANTS
8293 		(void)tqhash_insert(rack->r_ctl.tqh, rsm);
8294 #else
8295 		if ((insret = tqhash_insert(rack->r_ctl.tqh, rsm)) != 0) {
8296 			panic("Insert in tailq_hash of %p fails ret:%d rack:%p rsm:%p",
8297 			      nrsm, insret, rack, rsm);
8298 		}
8299 #endif
8300 		TAILQ_INSERT_TAIL(&rack->r_ctl.rc_tmap, rsm, r_tnext);
8301 		rsm->r_in_tmap = 1;
8302 		if (rsm->r_flags & RACK_IS_PCM) {
8303 			rack->r_ctl.pcm_i.send_time = cts;
8304 			rack->r_ctl.pcm_i.eseq = rsm->r_end;
8305 			/* First time through we set the start too */
8306 			if (rack->pcm_in_progress == 0)
8307 				rack->r_ctl.pcm_i.sseq = rsm->r_start;
8308 		}
8309 		/*
8310 		 * Special case detection, is there just a single
8311 		 * packet outstanding when we are not in recovery?
8312 		 *
8313 		 * If this is true mark it so.
8314 		 */
8315 		if ((IN_FASTRECOVERY(tp->t_flags) == 0) &&
8316 		    (ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked) == ctf_fixed_maxseg(tp))) {
8317 			struct rack_sendmap *prsm;
8318 
8319 			prsm = tqhash_prev(rack->r_ctl.tqh, rsm);
8320 			if (prsm)
8321 				prsm->r_one_out_nr = 1;
8322 		}
8323 		return;
8324 	}
8325 	/*
8326 	 * If we reach here its a retransmission and we need to find it.
8327 	 */
8328 more:
8329 	if (hintrsm && (hintrsm->r_start == seq_out)) {
8330 		rsm = hintrsm;
8331 		hintrsm = NULL;
8332 	} else {
8333 		/* No hints sorry */
8334 		rsm = NULL;
8335 	}
8336 	if ((rsm) && (rsm->r_start == seq_out)) {
8337 		seq_out = rack_update_entry(tp, rack, rsm, cts, &len, add_flag, segsiz);
8338 		if (len == 0) {
8339 			return;
8340 		} else {
8341 			goto more;
8342 		}
8343 	}
8344 	/* Ok it was not the last pointer go through it the hard way. */
8345 refind:
8346 	rsm = tqhash_find(rack->r_ctl.tqh, seq_out);
8347 	if (rsm) {
8348 		if (rsm->r_start == seq_out) {
8349 			seq_out = rack_update_entry(tp, rack, rsm, cts, &len, add_flag, segsiz);
8350 			if (len == 0) {
8351 				return;
8352 			} else {
8353 				goto refind;
8354 			}
8355 		}
8356 		if (SEQ_GEQ(seq_out, rsm->r_start) && SEQ_LT(seq_out, rsm->r_end)) {
8357 			/* Transmitted within this piece */
8358 			/*
8359 			 * Ok we must split off the front and then let the
8360 			 * update do the rest
8361 			 */
8362 			nrsm = rack_alloc_full_limit(rack);
8363 			if (nrsm == NULL) {
8364 				rack_update_rsm(tp, rack, rsm, cts, add_flag, segsiz);
8365 				return;
8366 			}
8367 			/*
8368 			 * copy rsm to nrsm and then trim the front of rsm
8369 			 * to not include this part.
8370 			 */
8371 			rack_clone_rsm(rack, nrsm, rsm, seq_out);
8372 			rack_log_map_chg(tp, rack, NULL, rsm, nrsm, MAP_SPLIT, 0, __LINE__);
8373 #ifndef INVARIANTS
8374 			(void)tqhash_insert(rack->r_ctl.tqh, nrsm);
8375 #else
8376 			if ((insret = tqhash_insert(rack->r_ctl.tqh, nrsm)) != 0) {
8377 				panic("Insert in tailq_hash of %p fails ret:%d rack:%p rsm:%p",
8378 				      nrsm, insret, rack, rsm);
8379 			}
8380 #endif
8381 			if (rsm->r_in_tmap) {
8382 				TAILQ_INSERT_AFTER(&rack->r_ctl.rc_tmap, rsm, nrsm, r_tnext);
8383 				nrsm->r_in_tmap = 1;
8384 			}
8385 			rsm->r_flags &= (~RACK_HAS_FIN);
8386 			seq_out = rack_update_entry(tp, rack, nrsm, cts, &len, add_flag, segsiz);
8387 			if (len == 0) {
8388 				return;
8389 			} else if (len > 0)
8390 				goto refind;
8391 		}
8392 	}
8393 	/*
8394 	 * Hmm not found in map did they retransmit both old and on into the
8395 	 * new?
8396 	 */
8397 	if (seq_out == tp->snd_max) {
8398 		goto again;
8399 	} else if (SEQ_LT(seq_out, tp->snd_max)) {
8400 #ifdef INVARIANTS
8401 		printf("seq_out:%u len:%d snd_una:%u snd_max:%u -- but rsm not found?\n",
8402 		       seq_out, len, tp->snd_una, tp->snd_max);
8403 		printf("Starting Dump of all rack entries\n");
8404 		TQHASH_FOREACH(rsm, rack->r_ctl.tqh)  {
8405 			printf("rsm:%p start:%u end:%u\n",
8406 			       rsm, rsm->r_start, rsm->r_end);
8407 		}
8408 		printf("Dump complete\n");
8409 		panic("seq_out not found rack:%p tp:%p",
8410 		      rack, tp);
8411 #endif
8412 	} else {
8413 #ifdef INVARIANTS
8414 		/*
8415 		 * Hmm beyond sndmax? (only if we are using the new rtt-pack
8416 		 * flag)
8417 		 */
8418 		panic("seq_out:%u(%d) is beyond snd_max:%u tp:%p",
8419 		      seq_out, len, tp->snd_max, tp);
8420 #endif
8421 	}
8422 }
8423 
8424 /*
8425  * Record one of the RTT updates from an ack into
8426  * our sample structure.
8427  */
8428 
8429 static void
8430 tcp_rack_xmit_timer(struct tcp_rack *rack, int32_t rtt, uint32_t len, uint32_t us_rtt,
8431 		    int confidence, struct rack_sendmap *rsm, uint16_t rtrcnt)
8432 {
8433 	if ((rack->r_ctl.rack_rs.rs_flags & RACK_RTT_EMPTY) ||
8434 	    (rack->r_ctl.rack_rs.rs_rtt_lowest > rtt)) {
8435 		rack->r_ctl.rack_rs.rs_rtt_lowest = rtt;
8436 	}
8437 	if ((rack->r_ctl.rack_rs.rs_flags & RACK_RTT_EMPTY) ||
8438 	    (rack->r_ctl.rack_rs.rs_rtt_highest < rtt)) {
8439 		rack->r_ctl.rack_rs.rs_rtt_highest = rtt;
8440 	}
8441 	if (rack->rc_tp->t_flags & TF_GPUTINPROG) {
8442 	    if (us_rtt < rack->r_ctl.rc_gp_lowrtt)
8443 		rack->r_ctl.rc_gp_lowrtt = us_rtt;
8444 	    if (rack->rc_tp->snd_wnd > rack->r_ctl.rc_gp_high_rwnd)
8445 		    rack->r_ctl.rc_gp_high_rwnd = rack->rc_tp->snd_wnd;
8446 	}
8447 	if ((confidence == 1) &&
8448 	    ((rsm == NULL) ||
8449 	     (rsm->r_just_ret) ||
8450 	     (rsm->r_one_out_nr &&
8451 	      len < (ctf_fixed_maxseg(rack->rc_tp) * 2)))) {
8452 		/*
8453 		 * If the rsm had a just return
8454 		 * hit it then we can't trust the
8455 		 * rtt measurement for buffer deterimination
8456 		 * Note that a confidence of 2, indicates
8457 		 * SACK'd which overrides the r_just_ret or
8458 		 * the r_one_out_nr. If it was a CUM-ACK and
8459 		 * we had only two outstanding, but get an
8460 		 * ack for only 1. Then that also lowers our
8461 		 * confidence.
8462 		 */
8463 		confidence = 0;
8464 	}
8465 	if ((rack->r_ctl.rack_rs.rs_flags & RACK_RTT_EMPTY) ||
8466 	    (rack->r_ctl.rack_rs.rs_us_rtt > us_rtt)) {
8467 		if (rack->r_ctl.rack_rs.confidence == 0) {
8468 			/*
8469 			 * We take anything with no current confidence
8470 			 * saved.
8471 			 */
8472 			rack->r_ctl.rack_rs.rs_us_rtt = us_rtt;
8473 			rack->r_ctl.rack_rs.confidence = confidence;
8474 			rack->r_ctl.rack_rs.rs_us_rtrcnt = rtrcnt;
8475 		} else if (confidence != 0) {
8476 			/*
8477 			 * Once we have a confident number,
8478 			 * we can update it with a smaller
8479 			 * value since this confident number
8480 			 * may include the DSACK time until
8481 			 * the next segment (the second one) arrived.
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 		}
8487 	}
8488 	rack_log_rtt_upd(rack->rc_tp, rack, us_rtt, len, rsm, confidence);
8489 	rack->r_ctl.rack_rs.rs_flags = RACK_RTT_VALID;
8490 	rack->r_ctl.rack_rs.rs_rtt_tot += rtt;
8491 	rack->r_ctl.rack_rs.rs_rtt_cnt++;
8492 }
8493 
8494 /*
8495  * Collect new round-trip time estimate
8496  * and update averages and current timeout.
8497  */
8498 static void
8499 tcp_rack_xmit_timer_commit(struct tcp_rack *rack, struct tcpcb *tp)
8500 {
8501 	int32_t delta;
8502 	int32_t rtt;
8503 
8504 	if (rack->r_ctl.rack_rs.rs_flags & RACK_RTT_EMPTY)
8505 		/* No valid sample */
8506 		return;
8507 	if (rack->r_ctl.rc_rate_sample_method == USE_RTT_LOW) {
8508 		/* We are to use the lowest RTT seen in a single ack */
8509 		rtt = rack->r_ctl.rack_rs.rs_rtt_lowest;
8510 	} else if (rack->r_ctl.rc_rate_sample_method == USE_RTT_HIGH) {
8511 		/* We are to use the highest RTT seen in a single ack */
8512 		rtt = rack->r_ctl.rack_rs.rs_rtt_highest;
8513 	} else if (rack->r_ctl.rc_rate_sample_method == USE_RTT_AVG) {
8514 		/* We are to use the average RTT seen in a single ack */
8515 		rtt = (int32_t)(rack->r_ctl.rack_rs.rs_rtt_tot /
8516 				(uint64_t)rack->r_ctl.rack_rs.rs_rtt_cnt);
8517 	} else {
8518 #ifdef INVARIANTS
8519 		panic("Unknown rtt variant %d", rack->r_ctl.rc_rate_sample_method);
8520 #endif
8521 		return;
8522 	}
8523 	if (rtt == 0)
8524 		rtt = 1;
8525 	if (rack->rc_gp_rtt_set == 0) {
8526 		/*
8527 		 * With no RTT we have to accept
8528 		 * even one we are not confident of.
8529 		 */
8530 		rack->r_ctl.rc_gp_srtt = rack->r_ctl.rack_rs.rs_us_rtt;
8531 		rack->rc_gp_rtt_set = 1;
8532 	} else if (rack->r_ctl.rack_rs.confidence) {
8533 		/* update the running gp srtt */
8534 		rack->r_ctl.rc_gp_srtt -= (rack->r_ctl.rc_gp_srtt/8);
8535 		rack->r_ctl.rc_gp_srtt += rack->r_ctl.rack_rs.rs_us_rtt / 8;
8536 	}
8537 	if (rack->r_ctl.rack_rs.confidence) {
8538 		/*
8539 		 * record the low and high for highly buffered path computation,
8540 		 * we only do this if we are confident (not a retransmission).
8541 		 */
8542 		if (rack->r_ctl.rc_highest_us_rtt < rack->r_ctl.rack_rs.rs_us_rtt) {
8543 			rack->r_ctl.rc_highest_us_rtt = rack->r_ctl.rack_rs.rs_us_rtt;
8544 		}
8545 		if (rack->rc_highly_buffered == 0) {
8546 			/*
8547 			 * Currently once we declare a path has
8548 			 * highly buffered there is no going
8549 			 * back, which may be a problem...
8550 			 */
8551 			if ((rack->r_ctl.rc_highest_us_rtt / rack->r_ctl.rc_lowest_us_rtt) > rack_hbp_thresh) {
8552 				rack_log_rtt_shrinks(rack, rack->r_ctl.rack_rs.rs_us_rtt,
8553 						     rack->r_ctl.rc_highest_us_rtt,
8554 						     rack->r_ctl.rc_lowest_us_rtt,
8555 						     RACK_RTTS_SEEHBP);
8556 				rack->rc_highly_buffered = 1;
8557 			}
8558 		}
8559 	}
8560 	if ((rack->r_ctl.rack_rs.confidence) ||
8561 	    (rack->r_ctl.rack_rs.rs_us_rtrcnt == 1)) {
8562 		/*
8563 		 * If we are highly confident of it <or> it was
8564 		 * never retransmitted we accept it as the last us_rtt.
8565 		 */
8566 		rack->r_ctl.rc_last_us_rtt = rack->r_ctl.rack_rs.rs_us_rtt;
8567 		/* The lowest rtt can be set if its was not retransmited */
8568 		if (rack->r_ctl.rc_lowest_us_rtt > rack->r_ctl.rack_rs.rs_us_rtt) {
8569 			rack->r_ctl.rc_lowest_us_rtt = rack->r_ctl.rack_rs.rs_us_rtt;
8570 			if (rack->r_ctl.rc_lowest_us_rtt == 0)
8571 				rack->r_ctl.rc_lowest_us_rtt = 1;
8572 		}
8573 	}
8574 	rack = (struct tcp_rack *)tp->t_fb_ptr;
8575 	if (tp->t_srtt != 0) {
8576 		/*
8577 		 * We keep a simple srtt in microseconds, like our rtt
8578 		 * measurement. We don't need to do any tricks with shifting
8579 		 * etc. Instead we just add in 1/8th of the new measurement
8580 		 * and subtract out 1/8 of the old srtt. We do the same with
8581 		 * the variance after finding the absolute value of the
8582 		 * difference between this sample and the current srtt.
8583 		 */
8584 		delta = tp->t_srtt - rtt;
8585 		/* Take off 1/8th of the current sRTT */
8586 		tp->t_srtt -= (tp->t_srtt >> 3);
8587 		/* Add in 1/8th of the new RTT just measured */
8588 		tp->t_srtt += (rtt >> 3);
8589 		if (tp->t_srtt <= 0)
8590 			tp->t_srtt = 1;
8591 		/* Now lets make the absolute value of the variance */
8592 		if (delta < 0)
8593 			delta = -delta;
8594 		/* Subtract out 1/8th */
8595 		tp->t_rttvar -= (tp->t_rttvar >> 3);
8596 		/* Add in 1/8th of the new variance we just saw */
8597 		tp->t_rttvar += (delta >> 3);
8598 		if (tp->t_rttvar <= 0)
8599 			tp->t_rttvar = 1;
8600 	} else {
8601 		/*
8602 		 * No rtt measurement yet - use the unsmoothed rtt. Set the
8603 		 * variance to half the rtt (so our first retransmit happens
8604 		 * at 3*rtt).
8605 		 */
8606 		tp->t_srtt = rtt;
8607 		tp->t_rttvar = rtt >> 1;
8608 	}
8609 	rack->rc_srtt_measure_made = 1;
8610 	KMOD_TCPSTAT_INC(tcps_rttupdated);
8611 	if (tp->t_rttupdated < UCHAR_MAX)
8612 		tp->t_rttupdated++;
8613 #ifdef STATS
8614 	if (rack_stats_gets_ms_rtt == 0) {
8615 		/* Send in the microsecond rtt used for rxt timeout purposes */
8616 		stats_voi_update_abs_u32(tp->t_stats, VOI_TCP_RTT, imax(0, rtt));
8617 	} else if (rack_stats_gets_ms_rtt == 1) {
8618 		/* Send in the millisecond rtt used for rxt timeout purposes */
8619 		int32_t ms_rtt;
8620 
8621 		/* Round up */
8622 		ms_rtt = (rtt + HPTS_USEC_IN_MSEC - 1) / HPTS_USEC_IN_MSEC;
8623 		stats_voi_update_abs_u32(tp->t_stats, VOI_TCP_RTT, imax(0, ms_rtt));
8624 	} else if (rack_stats_gets_ms_rtt == 2) {
8625 		/* Send in the millisecond rtt has close to the path RTT as we can get  */
8626 		int32_t ms_rtt;
8627 
8628 		/* Round up */
8629 		ms_rtt = (rack->r_ctl.rack_rs.rs_us_rtt + HPTS_USEC_IN_MSEC - 1) / HPTS_USEC_IN_MSEC;
8630 		stats_voi_update_abs_u32(tp->t_stats, VOI_TCP_RTT, imax(0, ms_rtt));
8631 	}  else {
8632 		/* Send in the microsecond rtt has close to the path RTT as we can get  */
8633 		stats_voi_update_abs_u32(tp->t_stats, VOI_TCP_RTT, imax(0, rack->r_ctl.rack_rs.rs_us_rtt));
8634 	}
8635 	stats_voi_update_abs_u32(tp->t_stats, VOI_TCP_PATHRTT, imax(0, rack->r_ctl.rack_rs.rs_us_rtt));
8636 #endif
8637 	rack->r_ctl.last_rcv_tstmp_for_rtt = tcp_tv_to_msec(&rack->r_ctl.act_rcv_time);
8638 	/*
8639 	 * the retransmit should happen at rtt + 4 * rttvar. Because of the
8640 	 * way we do the smoothing, srtt and rttvar will each average +1/2
8641 	 * tick of bias.  When we compute the retransmit timer, we want 1/2
8642 	 * tick of rounding and 1 extra tick because of +-1/2 tick
8643 	 * uncertainty in the firing of the timer.  The bias will give us
8644 	 * exactly the 1.5 tick we need.  But, because the bias is
8645 	 * statistical, we have to test that we don't drop below the minimum
8646 	 * feasible timer (which is 2 ticks).
8647 	 */
8648 	tp->t_rxtshift = 0;
8649 	RACK_TCPT_RANGESET(tp->t_rxtcur, RACK_REXMTVAL(tp),
8650 		      max(rack_rto_min, rtt + 2), rack_rto_max, rack->r_ctl.timer_slop);
8651 	rack_log_rtt_sample(rack, rtt);
8652 	tp->t_softerror = 0;
8653 }
8654 
8655 
8656 static void
8657 rack_apply_updated_usrtt(struct tcp_rack *rack, uint32_t us_rtt, uint32_t us_cts)
8658 {
8659 	/*
8660 	 * Apply to filter the inbound us-rtt at us_cts.
8661 	 */
8662 	uint32_t old_rtt;
8663 
8664 	old_rtt = get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt);
8665 	apply_filter_min_small(&rack->r_ctl.rc_gp_min_rtt,
8666 			       us_rtt, us_cts);
8667 	if (old_rtt > us_rtt) {
8668 		/* We just hit a new lower rtt time */
8669 		rack_log_rtt_shrinks(rack,  us_cts,  old_rtt,
8670 				     __LINE__, RACK_RTTS_NEWRTT);
8671 		/*
8672 		 * Only count it if its lower than what we saw within our
8673 		 * calculated range.
8674 		 */
8675 		if ((old_rtt - us_rtt) > rack_min_rtt_movement) {
8676 			if (rack_probertt_lower_within &&
8677 			    rack->rc_gp_dyn_mul &&
8678 			    (rack->use_fixed_rate == 0) &&
8679 			    (rack->rc_always_pace)) {
8680 				/*
8681 				 * We are seeing a new lower rtt very close
8682 				 * to the time that we would have entered probe-rtt.
8683 				 * This is probably due to the fact that a peer flow
8684 				 * has entered probe-rtt. Lets go in now too.
8685 				 */
8686 				uint32_t val;
8687 
8688 				val = rack_probertt_lower_within * rack_time_between_probertt;
8689 				val /= 100;
8690 				if ((rack->in_probe_rtt == 0) &&
8691 				    (rack->rc_skip_timely == 0) &&
8692 				    ((us_cts - rack->r_ctl.rc_lower_rtt_us_cts) >= (rack_time_between_probertt - val)))	{
8693 					rack_enter_probertt(rack, us_cts);
8694 				}
8695 			}
8696 			rack->r_ctl.rc_lower_rtt_us_cts = us_cts;
8697 		}
8698 	}
8699 }
8700 
8701 static int
8702 rack_update_rtt(struct tcpcb *tp, struct tcp_rack *rack,
8703     struct rack_sendmap *rsm, struct tcpopt *to, uint32_t cts, int32_t ack_type, tcp_seq th_ack)
8704 {
8705 	uint32_t us_rtt;
8706 	int32_t i, all;
8707 	uint32_t t, len_acked;
8708 
8709 	if ((rsm->r_flags & RACK_ACKED) ||
8710 	    (rsm->r_flags & RACK_WAS_ACKED))
8711 		/* Already done */
8712 		return (0);
8713 	if (rsm->r_no_rtt_allowed) {
8714 		/* Not allowed */
8715 		return (0);
8716 	}
8717 	if (ack_type == CUM_ACKED) {
8718 		if (SEQ_GT(th_ack, rsm->r_end)) {
8719 			len_acked = rsm->r_end - rsm->r_start;
8720 			all = 1;
8721 		} else {
8722 			len_acked = th_ack - rsm->r_start;
8723 			all = 0;
8724 		}
8725 	} else {
8726 		len_acked = rsm->r_end - rsm->r_start;
8727 		all = 0;
8728 	}
8729 	if (rsm->r_rtr_cnt == 1) {
8730 
8731 		t = cts - (uint32_t)rsm->r_tim_lastsent[(rsm->r_rtr_cnt - 1)];
8732 		if ((int)t <= 0)
8733 			t = 1;
8734 		if (!tp->t_rttlow || tp->t_rttlow > t)
8735 			tp->t_rttlow = t;
8736 		if (!rack->r_ctl.rc_rack_min_rtt ||
8737 		    SEQ_LT(t, rack->r_ctl.rc_rack_min_rtt)) {
8738 			rack->r_ctl.rc_rack_min_rtt = t;
8739 			if (rack->r_ctl.rc_rack_min_rtt == 0) {
8740 				rack->r_ctl.rc_rack_min_rtt = 1;
8741 			}
8742 		}
8743 		if (TSTMP_GT(tcp_tv_to_usec(&rack->r_ctl.act_rcv_time), rsm->r_tim_lastsent[(rsm->r_rtr_cnt-1)]))
8744 			us_rtt = tcp_tv_to_usec(&rack->r_ctl.act_rcv_time) - (uint32_t)rsm->r_tim_lastsent[(rsm->r_rtr_cnt-1)];
8745 		else
8746 			us_rtt = tcp_get_usecs(NULL) - (uint32_t)rsm->r_tim_lastsent[(rsm->r_rtr_cnt-1)];
8747 		if (us_rtt == 0)
8748 			us_rtt = 1;
8749 		if (CC_ALGO(tp)->rttsample != NULL) {
8750 			/* Kick the RTT to the CC */
8751 			CC_ALGO(tp)->rttsample(&tp->t_ccv, us_rtt, 1, rsm->r_fas);
8752 		}
8753 		rack_apply_updated_usrtt(rack, us_rtt, tcp_tv_to_usec(&rack->r_ctl.act_rcv_time));
8754 		if (ack_type == SACKED) {
8755 			rack_log_rtt_sample_calc(rack, t, (uint32_t)rsm->r_tim_lastsent[(rsm->r_rtr_cnt - 1)], cts, 1);
8756 			tcp_rack_xmit_timer(rack, t + 1, len_acked, us_rtt, 2 , rsm, rsm->r_rtr_cnt);
8757 		} else {
8758 			/*
8759 			 * We need to setup what our confidence
8760 			 * is in this ack.
8761 			 *
8762 			 * If the rsm was app limited and it is
8763 			 * less than a mss in length (the end
8764 			 * of the send) then we have a gap. If we
8765 			 * were app limited but say we were sending
8766 			 * multiple MSS's then we are more confident
8767 			 * int it.
8768 			 *
8769 			 * When we are not app-limited then we see if
8770 			 * the rsm is being included in the current
8771 			 * measurement, we tell this by the app_limited_needs_set
8772 			 * flag.
8773 			 *
8774 			 * Note that being cwnd blocked is not applimited
8775 			 * as well as the pacing delay between packets which
8776 			 * are sending only 1 or 2 MSS's also will show up
8777 			 * in the RTT. We probably need to examine this algorithm
8778 			 * a bit more and enhance it to account for the delay
8779 			 * between rsm's. We could do that by saving off the
8780 			 * pacing delay of each rsm (in an rsm) and then
8781 			 * factoring that in somehow though for now I am
8782 			 * not sure how :)
8783 			 */
8784 			int calc_conf = 0;
8785 
8786 			if (rsm->r_flags & RACK_APP_LIMITED) {
8787 				if (all && (len_acked <= ctf_fixed_maxseg(tp)))
8788 					calc_conf = 0;
8789 				else
8790 					calc_conf = 1;
8791 			} else if (rack->app_limited_needs_set == 0) {
8792 				calc_conf = 1;
8793 			} else {
8794 				calc_conf = 0;
8795 			}
8796 			rack_log_rtt_sample_calc(rack, t, (uint32_t)rsm->r_tim_lastsent[(rsm->r_rtr_cnt - 1)], cts, 2);
8797 			tcp_rack_xmit_timer(rack, t + 1, len_acked, us_rtt,
8798 					    calc_conf, rsm, rsm->r_rtr_cnt);
8799 		}
8800 		if ((rsm->r_flags & RACK_TLP) &&
8801 		    (!IN_FASTRECOVERY(tp->t_flags))) {
8802 			/* Segment was a TLP and our retrans matched */
8803 			if (rack->r_ctl.rc_tlp_cwnd_reduce) {
8804 				rack_cong_signal(tp, CC_NDUPACK, th_ack, __LINE__);
8805 			}
8806 		}
8807 		if ((rack->r_ctl.rc_rack_tmit_time == 0) ||
8808 		    (SEQ_LT(rack->r_ctl.rc_rack_tmit_time,
8809 			    (uint32_t)rsm->r_tim_lastsent[(rsm->r_rtr_cnt - 1)]))) {
8810 			/* New more recent rack_tmit_time */
8811 			rack->r_ctl.rc_rack_tmit_time = (uint32_t)rsm->r_tim_lastsent[(rsm->r_rtr_cnt - 1)];
8812 			if (rack->r_ctl.rc_rack_tmit_time == 0)
8813 				rack->r_ctl.rc_rack_tmit_time = 1;
8814 			rack->rc_rack_rtt = t;
8815 		}
8816 		return (1);
8817 	}
8818 	/*
8819 	 * We clear the soft/rxtshift since we got an ack.
8820 	 * There is no assurance we will call the commit() function
8821 	 * so we need to clear these to avoid incorrect handling.
8822 	 */
8823 	tp->t_rxtshift = 0;
8824 	RACK_TCPT_RANGESET(tp->t_rxtcur, RACK_REXMTVAL(tp),
8825 		      rack_rto_min, rack_rto_max, rack->r_ctl.timer_slop);
8826 	tp->t_softerror = 0;
8827 	if (to && (to->to_flags & TOF_TS) &&
8828 	    (ack_type == CUM_ACKED) &&
8829 	    (to->to_tsecr) &&
8830 	    ((rsm->r_flags & RACK_OVERMAX) == 0)) {
8831 		/*
8832 		 * Now which timestamp does it match? In this block the ACK
8833 		 * must be coming from a previous transmission.
8834 		 */
8835 		for (i = 0; i < rsm->r_rtr_cnt; i++) {
8836 			if (rack_ts_to_msec(rsm->r_tim_lastsent[i]) == to->to_tsecr) {
8837 				t = cts - (uint32_t)rsm->r_tim_lastsent[i];
8838 				if ((int)t <= 0)
8839 					t = 1;
8840 				if (CC_ALGO(tp)->rttsample != NULL) {
8841 					/*
8842 					 * Kick the RTT to the CC, here
8843 					 * we lie a bit in that we know the
8844 					 * retransmission is correct even though
8845 					 * we retransmitted. This is because
8846 					 * we match the timestamps.
8847 					 */
8848 					if (TSTMP_GT(tcp_tv_to_usec(&rack->r_ctl.act_rcv_time), rsm->r_tim_lastsent[i]))
8849 						us_rtt = tcp_tv_to_usec(&rack->r_ctl.act_rcv_time) - (uint32_t)rsm->r_tim_lastsent[i];
8850 					else
8851 						us_rtt = tcp_get_usecs(NULL) - (uint32_t)rsm->r_tim_lastsent[i];
8852 					CC_ALGO(tp)->rttsample(&tp->t_ccv, us_rtt, 1, rsm->r_fas);
8853 				}
8854 				if ((i + 1) < rsm->r_rtr_cnt) {
8855 					/*
8856 					 * The peer ack'd from our previous
8857 					 * transmission. We have a spurious
8858 					 * retransmission and thus we dont
8859 					 * want to update our rack_rtt.
8860 					 *
8861 					 * Hmm should there be a CC revert here?
8862 					 *
8863 					 */
8864 					return (0);
8865 				}
8866 				if (!tp->t_rttlow || tp->t_rttlow > t)
8867 					tp->t_rttlow = t;
8868 				if (!rack->r_ctl.rc_rack_min_rtt || SEQ_LT(t, rack->r_ctl.rc_rack_min_rtt)) {
8869 					rack->r_ctl.rc_rack_min_rtt = t;
8870 					if (rack->r_ctl.rc_rack_min_rtt == 0) {
8871 						rack->r_ctl.rc_rack_min_rtt = 1;
8872 					}
8873 				}
8874 				if ((rack->r_ctl.rc_rack_tmit_time == 0) ||
8875 				    (SEQ_LT(rack->r_ctl.rc_rack_tmit_time,
8876 					    (uint32_t)rsm->r_tim_lastsent[(rsm->r_rtr_cnt - 1)]))) {
8877 					/* New more recent rack_tmit_time */
8878 					rack->r_ctl.rc_rack_tmit_time = (uint32_t)rsm->r_tim_lastsent[(rsm->r_rtr_cnt - 1)];
8879 					if (rack->r_ctl.rc_rack_tmit_time == 0)
8880 						rack->r_ctl.rc_rack_tmit_time = 1;
8881 					rack->rc_rack_rtt = t;
8882 				}
8883 				rack_log_rtt_sample_calc(rack, t, (uint32_t)rsm->r_tim_lastsent[i], cts, 3);
8884 				tcp_rack_xmit_timer(rack, t + 1, len_acked, t, 0, rsm,
8885 						    rsm->r_rtr_cnt);
8886 				return (1);
8887 			}
8888 		}
8889 		/* If we are logging log out the sendmap */
8890 		if (tcp_bblogging_on(rack->rc_tp)) {
8891 			for (i = 0; i < rsm->r_rtr_cnt; i++) {
8892 				rack_log_rtt_sendmap(rack, i, rsm->r_tim_lastsent[i], to->to_tsecr);
8893 			}
8894 		}
8895 		goto ts_not_found;
8896 	} else {
8897 		/*
8898 		 * Ok its a SACK block that we retransmitted. or a windows
8899 		 * machine without timestamps. We can tell nothing from the
8900 		 * time-stamp since its not there or the time the peer last
8901 		 * received a segment that moved forward its cum-ack point.
8902 		 */
8903 ts_not_found:
8904 		i = rsm->r_rtr_cnt - 1;
8905 		t = cts - (uint32_t)rsm->r_tim_lastsent[i];
8906 		if ((int)t <= 0)
8907 			t = 1;
8908 		if (rack->r_ctl.rc_rack_min_rtt && SEQ_LT(t, rack->r_ctl.rc_rack_min_rtt)) {
8909 			/*
8910 			 * We retransmitted and the ack came back in less
8911 			 * than the smallest rtt we have observed. We most
8912 			 * likely did an improper retransmit as outlined in
8913 			 * 6.2 Step 2 point 2 in the rack-draft so we
8914 			 * don't want to update our rack_rtt. We in
8915 			 * theory (in future) might want to think about reverting our
8916 			 * cwnd state but we won't for now.
8917 			 */
8918 			return (0);
8919 		} else if (rack->r_ctl.rc_rack_min_rtt) {
8920 			/*
8921 			 * We retransmitted it and the retransmit did the
8922 			 * job.
8923 			 */
8924 			if (!rack->r_ctl.rc_rack_min_rtt ||
8925 			    SEQ_LT(t, rack->r_ctl.rc_rack_min_rtt)) {
8926 				rack->r_ctl.rc_rack_min_rtt = t;
8927 				if (rack->r_ctl.rc_rack_min_rtt == 0) {
8928 					rack->r_ctl.rc_rack_min_rtt = 1;
8929 				}
8930 			}
8931 			if ((rack->r_ctl.rc_rack_tmit_time == 0) ||
8932 			    (SEQ_LT(rack->r_ctl.rc_rack_tmit_time,
8933 				    (uint32_t)rsm->r_tim_lastsent[i]))) {
8934 				/* New more recent rack_tmit_time */
8935 				rack->r_ctl.rc_rack_tmit_time = (uint32_t)rsm->r_tim_lastsent[i];
8936 				if (rack->r_ctl.rc_rack_tmit_time == 0)
8937 					rack->r_ctl.rc_rack_tmit_time = 1;
8938 				rack->rc_rack_rtt = t;
8939 			}
8940 			return (1);
8941 		}
8942 	}
8943 	return (0);
8944 }
8945 
8946 /*
8947  * Mark the SACK_PASSED flag on all entries prior to rsm send wise.
8948  */
8949 static void
8950 rack_log_sack_passed(struct tcpcb *tp,
8951     struct tcp_rack *rack, struct rack_sendmap *rsm, uint32_t cts)
8952 {
8953 	struct rack_sendmap *nrsm;
8954 	uint32_t thresh;
8955 
8956 	/* Get our rxt threshold for lost consideration */
8957 	thresh = rack_calc_thresh_rack(rack, rack_grab_rtt(tp, rack), cts, __LINE__, 0);
8958 	/* Now start looking at rsm's */
8959 	nrsm = rsm;
8960 	TAILQ_FOREACH_REVERSE_FROM(nrsm, &rack->r_ctl.rc_tmap,
8961 	    rack_head, r_tnext) {
8962 		if (nrsm == rsm) {
8963 			/* Skip original segment he is acked */
8964 			continue;
8965 		}
8966 		if (nrsm->r_flags & RACK_ACKED) {
8967 			/*
8968 			 * Skip ack'd segments, though we
8969 			 * should not see these, since tmap
8970 			 * should not have ack'd segments.
8971 			 */
8972 			continue;
8973 		}
8974 		if (nrsm->r_flags & RACK_RWND_COLLAPSED) {
8975 			/*
8976 			 * If the peer dropped the rwnd on
8977 			 * these then we don't worry about them.
8978 			 */
8979 			continue;
8980 		}
8981 		/* Check lost state */
8982 		if ((nrsm->r_flags & RACK_WAS_LOST) == 0) {
8983 			uint32_t exp;
8984 
8985 			exp = ((uint32_t)rsm->r_tim_lastsent[(rsm->r_rtr_cnt - 1)]) + thresh;
8986 			if (TSTMP_LT(exp, cts) || (exp == cts)) {
8987 				/* We consider it lost */
8988 				nrsm->r_flags |= RACK_WAS_LOST;
8989 				rack->r_ctl.rc_considered_lost += nrsm->r_end - nrsm->r_start;
8990 			}
8991 		}
8992 		if (nrsm->r_flags & RACK_SACK_PASSED) {
8993 			/*
8994 			 * We found one that is already marked
8995 			 * passed, we have been here before and
8996 			 * so all others below this are marked.
8997 			 */
8998 			break;
8999 		}
9000 		nrsm->r_flags |= RACK_SACK_PASSED;
9001 		nrsm->r_flags &= ~RACK_WAS_SACKPASS;
9002 	}
9003 }
9004 
9005 static void
9006 rack_need_set_test(struct tcpcb *tp,
9007 		   struct tcp_rack *rack,
9008 		   struct rack_sendmap *rsm,
9009 		   tcp_seq th_ack,
9010 		   int line,
9011 		   int use_which)
9012 {
9013 	struct rack_sendmap *s_rsm;
9014 
9015 	if ((tp->t_flags & TF_GPUTINPROG) &&
9016 	    SEQ_GEQ(rsm->r_end, tp->gput_seq)) {
9017 		/*
9018 		 * We were app limited, and this ack
9019 		 * butts up or goes beyond the point where we want
9020 		 * to start our next measurement. We need
9021 		 * to record the new gput_ts as here and
9022 		 * possibly update the start sequence.
9023 		 */
9024 		uint32_t seq, ts;
9025 
9026 		if (rsm->r_rtr_cnt > 1) {
9027 			/*
9028 			 * This is a retransmit, can we
9029 			 * really make any assessment at this
9030 			 * point?  We are not really sure of
9031 			 * the timestamp, is it this or the
9032 			 * previous transmission?
9033 			 *
9034 			 * Lets wait for something better that
9035 			 * is not retransmitted.
9036 			 */
9037 			return;
9038 		}
9039 		seq = tp->gput_seq;
9040 		ts = tp->gput_ts;
9041 		rack->app_limited_needs_set = 0;
9042 		tp->gput_ts = tcp_tv_to_usec(&rack->r_ctl.act_rcv_time);
9043 		/* Do we start at a new end? */
9044 		if ((use_which == RACK_USE_BEG) &&
9045 		    SEQ_GEQ(rsm->r_start, tp->gput_seq)) {
9046 			/*
9047 			 * When we get an ACK that just eats
9048 			 * up some of the rsm, we set RACK_USE_BEG
9049 			 * since whats at r_start (i.e. th_ack)
9050 			 * is left unacked and thats where the
9051 			 * measurement now starts.
9052 			 */
9053 			tp->gput_seq = rsm->r_start;
9054 		}
9055 		if ((use_which == RACK_USE_END) &&
9056 		    SEQ_GEQ(rsm->r_end, tp->gput_seq)) {
9057 			/*
9058 			 * We use the end when the cumack
9059 			 * is moving forward and completely
9060 			 * deleting the rsm passed so basically
9061 			 * r_end holds th_ack.
9062 			 *
9063 			 * For SACK's we also want to use the end
9064 			 * since this piece just got sacked and
9065 			 * we want to target anything after that
9066 			 * in our measurement.
9067 			 */
9068 			tp->gput_seq = rsm->r_end;
9069 		}
9070 		if (use_which == RACK_USE_END_OR_THACK) {
9071 			/*
9072 			 * special case for ack moving forward,
9073 			 * not a sack, we need to move all the
9074 			 * way up to where this ack cum-ack moves
9075 			 * to.
9076 			 */
9077 			if (SEQ_GT(th_ack, rsm->r_end))
9078 				tp->gput_seq = th_ack;
9079 			else
9080 				tp->gput_seq = rsm->r_end;
9081 		}
9082 		if (SEQ_LT(tp->gput_seq, tp->snd_max))
9083 			s_rsm = tqhash_find(rack->r_ctl.tqh, tp->gput_seq);
9084 		else
9085 			s_rsm = NULL;
9086 		/*
9087 		 * Pick up the correct send time if we can the rsm passed in
9088 		 * may be equal to s_rsm if the RACK_USE_BEG was set. For the other
9089 		 * two cases (RACK_USE_THACK or RACK_USE_END) most likely we will
9090 		 * find a different seq i.e. the next send up.
9091 		 *
9092 		 * If that has not been sent, s_rsm will be NULL and we must
9093 		 * arrange it so this function will get called again by setting
9094 		 * app_limited_needs_set.
9095 		 */
9096 		if (s_rsm)
9097 			rack->r_ctl.rc_gp_output_ts = s_rsm->r_tim_lastsent[0];
9098 		else {
9099 			/* If we hit here we have to have *not* sent tp->gput_seq */
9100 			rack->r_ctl.rc_gp_output_ts = rsm->r_tim_lastsent[0];
9101 			/* Set it up so we will go through here again */
9102 			rack->app_limited_needs_set = 1;
9103 		}
9104 		if (SEQ_GT(tp->gput_seq, tp->gput_ack)) {
9105 			/*
9106 			 * We moved beyond this guy's range, re-calculate
9107 			 * the new end point.
9108 			 */
9109 			if (rack->rc_gp_filled == 0) {
9110 				tp->gput_ack = tp->gput_seq + max(rc_init_window(rack), (MIN_GP_WIN * ctf_fixed_maxseg(tp)));
9111 			} else {
9112 				tp->gput_ack = tp->gput_seq + rack_get_measure_window(tp, rack);
9113 			}
9114 		}
9115 		/*
9116 		 * We are moving the goal post, we may be able to clear the
9117 		 * measure_saw_probe_rtt flag.
9118 		 */
9119 		if ((rack->in_probe_rtt == 0) &&
9120 		    (rack->measure_saw_probe_rtt) &&
9121 		    (SEQ_GEQ(tp->gput_seq, rack->r_ctl.rc_probertt_sndmax_atexit)))
9122 			rack->measure_saw_probe_rtt = 0;
9123 		rack_log_pacing_delay_calc(rack, ts, tp->gput_ts,
9124 					   seq, tp->gput_seq,
9125 					   (((uint64_t)rack->r_ctl.rc_app_limited_cnt << 32) |
9126 					    (uint64_t)rack->r_ctl.rc_gp_output_ts),
9127 					   5, line, NULL, 0);
9128 		if (rack->rc_gp_filled &&
9129 		    ((tp->gput_ack - tp->gput_seq) <
9130 		     max(rc_init_window(rack), (MIN_GP_WIN *
9131 						ctf_fixed_maxseg(tp))))) {
9132 			uint32_t ideal_amount;
9133 
9134 			ideal_amount = rack_get_measure_window(tp, rack);
9135 			if (ideal_amount > sbavail(&tptosocket(tp)->so_snd)) {
9136 				/*
9137 				 * There is no sense of continuing this measurement
9138 				 * because its too small to gain us anything we
9139 				 * trust. Skip it and that way we can start a new
9140 				 * measurement quicker.
9141 				 */
9142 				tp->t_flags &= ~TF_GPUTINPROG;
9143 				rack_log_pacing_delay_calc(rack, tp->gput_ack, tp->gput_seq,
9144 							   0, 0,
9145 							   (((uint64_t)rack->r_ctl.rc_app_limited_cnt << 32) |
9146 							    (uint64_t)rack->r_ctl.rc_gp_output_ts),
9147 							   6, __LINE__, NULL, 0);
9148 			} else {
9149 				/*
9150 				 * Reset the window further out.
9151 				 */
9152 				tp->gput_ack = tp->gput_seq + ideal_amount;
9153 			}
9154 		}
9155 		rack_tend_gp_marks(tp, rack);
9156 		rack_log_gpset(rack, tp->gput_ack, 0, 0, line, 2, rsm);
9157 	}
9158 }
9159 
9160 static inline int
9161 is_rsm_inside_declared_tlp_block(struct tcp_rack *rack, struct rack_sendmap *rsm)
9162 {
9163 	if (SEQ_LT(rsm->r_end, rack->r_ctl.last_tlp_acked_start)) {
9164 		/* Behind our TLP definition or right at */
9165 		return (0);
9166 	}
9167 	if (SEQ_GT(rsm->r_start, rack->r_ctl.last_tlp_acked_end)) {
9168 		/* The start is beyond or right at our end of TLP definition */
9169 		return (0);
9170 	}
9171 	/* It has to be a sub-part of the original TLP recorded */
9172 	return (1);
9173 }
9174 
9175 static uint32_t
9176 rack_proc_sack_blk(struct tcpcb *tp, struct tcp_rack *rack, struct sackblk *sack,
9177 		   struct tcpopt *to, struct rack_sendmap **prsm, uint32_t cts,
9178 		   uint32_t segsiz)
9179 {
9180 	uint32_t start, end, changed = 0;
9181 	struct rack_sendmap stack_map;
9182 	struct rack_sendmap *rsm, *nrsm, *prev, *next;
9183 	int insret __diagused;
9184 	int32_t used_ref = 1;
9185 	int can_use_hookery = 0;
9186 
9187 	start = sack->start;
9188 	end = sack->end;
9189 	rsm = *prsm;
9190 
9191 do_rest_ofb:
9192 	if ((rsm == NULL) ||
9193 	    (SEQ_LT(end, rsm->r_start)) ||
9194 	    (SEQ_GEQ(start, rsm->r_end)) ||
9195 	    (SEQ_LT(start, rsm->r_start))) {
9196 		/*
9197 		 * We are not in the right spot,
9198 		 * find the correct spot in the tree.
9199 		 */
9200 		used_ref = 0;
9201 		rsm = tqhash_find(rack->r_ctl.tqh, start);
9202 	}
9203 	if (rsm == NULL) {
9204 		/* TSNH */
9205 		goto out;
9206 	}
9207 	/* Ok we have an ACK for some piece of this rsm */
9208 	if (rsm->r_start != start) {
9209 		if ((rsm->r_flags & RACK_ACKED) == 0) {
9210 			/*
9211 			 * Before any splitting or hookery is
9212 			 * done is it a TLP of interest i.e. rxt?
9213 			 */
9214 			if ((rsm->r_flags & RACK_TLP) &&
9215 			    (rsm->r_rtr_cnt > 1)) {
9216 				/*
9217 				 * We are splitting a rxt TLP, check
9218 				 * if we need to save off the start/end
9219 				 */
9220 				if (rack->rc_last_tlp_acked_set &&
9221 				    (is_rsm_inside_declared_tlp_block(rack, rsm))) {
9222 					/*
9223 					 * We already turned this on since we are inside
9224 					 * the previous one was a partially sack now we
9225 					 * are getting another one (maybe all of it).
9226 					 *
9227 					 */
9228 					rack_log_dsack_event(rack, 10, __LINE__, rsm->r_start, rsm->r_end);
9229 					/*
9230 					 * Lets make sure we have all of it though.
9231 					 */
9232 					if (SEQ_LT(rsm->r_start, rack->r_ctl.last_tlp_acked_start)) {
9233 						rack->r_ctl.last_tlp_acked_start = rsm->r_start;
9234 						rack_log_dsack_event(rack, 11, __LINE__, rack->r_ctl.last_tlp_acked_start,
9235 								     rack->r_ctl.last_tlp_acked_end);
9236 					}
9237 					if (SEQ_GT(rsm->r_end, rack->r_ctl.last_tlp_acked_end)) {
9238 						rack->r_ctl.last_tlp_acked_end = rsm->r_end;
9239 						rack_log_dsack_event(rack, 11, __LINE__, rack->r_ctl.last_tlp_acked_start,
9240 								     rack->r_ctl.last_tlp_acked_end);
9241 					}
9242 				} else {
9243 					rack->r_ctl.last_tlp_acked_start = rsm->r_start;
9244 					rack->r_ctl.last_tlp_acked_end = rsm->r_end;
9245 					rack->rc_last_tlp_past_cumack = 0;
9246 					rack->rc_last_tlp_acked_set = 1;
9247 					rack_log_dsack_event(rack, 8, __LINE__, rsm->r_start, rsm->r_end);
9248 				}
9249 			}
9250 			/**
9251 			 * Need to split this in two pieces the before and after,
9252 			 * the before remains in the map, the after must be
9253 			 * added. In other words we have:
9254 			 * rsm        |--------------|
9255 			 * sackblk        |------->
9256 			 * rsm will become
9257 			 *     rsm    |---|
9258 			 * and nrsm will be  the sacked piece
9259 			 *     nrsm       |----------|
9260 			 *
9261 			 * But before we start down that path lets
9262 			 * see if the sack spans over on top of
9263 			 * the next guy and it is already sacked.
9264 			 *
9265 			 */
9266 			/*
9267 			 * Hookery can only be used if the two entries
9268 			 * are in the same bucket and neither one of
9269 			 * them staddle the bucket line.
9270 			 */
9271 			next = tqhash_next(rack->r_ctl.tqh, rsm);
9272 			if (next &&
9273 			    (rsm->bindex == next->bindex) &&
9274 			    ((rsm->r_flags & RACK_STRADDLE) == 0) &&
9275 			    ((next->r_flags & RACK_STRADDLE) == 0) &&
9276 			    ((rsm->r_flags & RACK_IS_PCM) == 0) &&
9277 			    ((next->r_flags & RACK_IS_PCM) == 0) &&
9278 			    (rsm->r_flags & RACK_IN_GP_WIN) &&
9279 			    (next->r_flags & RACK_IN_GP_WIN))
9280 				can_use_hookery = 1;
9281 			else
9282 				can_use_hookery = 0;
9283 			if (next && can_use_hookery &&
9284 			    (next->r_flags & RACK_ACKED) &&
9285 			    SEQ_GEQ(end, next->r_start)) {
9286 				/**
9287 				 * So the next one is already acked, and
9288 				 * we can thus by hookery use our stack_map
9289 				 * to reflect the piece being sacked and
9290 				 * then adjust the two tree entries moving
9291 				 * the start and ends around. So we start like:
9292 				 *  rsm     |------------|             (not-acked)
9293 				 *  next                 |-----------| (acked)
9294 				 *  sackblk        |-------->
9295 				 *  We want to end like so:
9296 				 *  rsm     |------|                   (not-acked)
9297 				 *  next           |-----------------| (acked)
9298 				 *  nrsm           |-----|
9299 				 * Where nrsm is a temporary stack piece we
9300 				 * use to update all the gizmos.
9301 				 */
9302 				/* Copy up our fudge block */
9303 				nrsm = &stack_map;
9304 				memcpy(nrsm, rsm, sizeof(struct rack_sendmap));
9305 				/* Now adjust our tree blocks */
9306 				tqhash_update_end(rack->r_ctl.tqh, rsm, start);
9307 				next->r_start = start;
9308  				rsm->r_flags |= RACK_SHUFFLED;
9309 				next->r_flags |= RACK_SHUFFLED;
9310 				/* Now we must adjust back where next->m is */
9311 				rack_setup_offset_for_rsm(rack, rsm, next);
9312 				/*
9313 				 * Which timestamp do we keep? It is rather
9314 				 * important in GP measurements to have the
9315 				 * accurate end of the send window.
9316 				 *
9317 				 * We keep the largest value, which is the newest
9318 				 * send. We do this in case a segment that is
9319 				 * joined together and not part of a GP estimate
9320 				 * later gets expanded into the GP estimate.
9321 				 *
9322 				 * We prohibit the merging of unlike kinds i.e.
9323 				 * all pieces that are in the GP estimate can be
9324 				 * merged and all pieces that are not in a GP estimate
9325 				 * can be merged, but not disimilar pieces. Combine
9326 				 * this with taking the highest here and we should
9327 				 * be ok unless of course the client reneges. Then
9328 				 * all bets are off.
9329 				 */
9330 				if (next->r_tim_lastsent[(next->r_rtr_cnt-1)] <
9331 				    nrsm->r_tim_lastsent[(nrsm->r_rtr_cnt-1)])
9332 					next->r_tim_lastsent[(next->r_rtr_cnt-1)] = nrsm->r_tim_lastsent[(nrsm->r_rtr_cnt-1)];
9333 				/*
9334 				 * And we must keep the newest ack arrival time.
9335 				 */
9336 				if (next->r_ack_arrival <
9337 				    rack_to_usec_ts(&rack->r_ctl.act_rcv_time))
9338 					next->r_ack_arrival = rack_to_usec_ts(&rack->r_ctl.act_rcv_time);
9339 
9340 
9341 				/* We don't need to adjust rsm, it did not change */
9342 				/* Clear out the dup ack count of the remainder */
9343 				rsm->r_dupack = 0;
9344 				rsm->r_just_ret = 0;
9345 				rack_log_retran_reason(rack, rsm, __LINE__, 0, 2);
9346 				/* Now lets make sure our fudge block is right */
9347 				nrsm->r_start = start;
9348 				/* Now lets update all the stats and such */
9349 				rack_update_rtt(tp, rack, nrsm, to, cts, SACKED, 0);
9350 				if (rack->app_limited_needs_set)
9351 					rack_need_set_test(tp, rack, nrsm, tp->snd_una, __LINE__, RACK_USE_END);
9352 				changed += (nrsm->r_end - nrsm->r_start);
9353 				rack->r_ctl.rc_sacked += (nrsm->r_end - nrsm->r_start);
9354 				if (rsm->r_flags & RACK_WAS_LOST) {
9355 					int my_chg;
9356 
9357 					/*
9358 					 * Note here we do not use our rack_mark_nolonger_lost() function
9359 					 * since we are moving our data pointer around and the
9360 					 * ack'ed side is already not considered lost.
9361 					 */
9362 					my_chg = (nrsm->r_end - nrsm->r_start);
9363 					KASSERT((rack->r_ctl.rc_considered_lost >= my_chg),
9364 						("rsm:%p rack:%p rc_considered_lost goes negative", rsm,  rack));
9365 					if (my_chg <= rack->r_ctl.rc_considered_lost)
9366 						rack->r_ctl.rc_considered_lost -= my_chg;
9367 					else
9368 						rack->r_ctl.rc_considered_lost = 0;
9369 				}
9370 				if (nrsm->r_flags & RACK_SACK_PASSED) {
9371 					rack->r_ctl.rc_reorder_ts = cts;
9372 					if (rack->r_ctl.rc_reorder_ts == 0)
9373 						rack->r_ctl.rc_reorder_ts = 1;
9374 				}
9375 				/*
9376 				 * Now we want to go up from rsm (the
9377 				 * one left un-acked) to the next one
9378 				 * in the tmap. We do this so when
9379 				 * we walk backwards we include marking
9380 				 * sack-passed on rsm (The one passed in
9381 				 * is skipped since it is generally called
9382 				 * on something sacked before removing it
9383 				 * from the tmap).
9384 				 */
9385 				if (rsm->r_in_tmap) {
9386 					nrsm = TAILQ_NEXT(rsm, r_tnext);
9387 					/*
9388 					 * Now that we have the next
9389 					 * one walk backwards from there.
9390 					 */
9391 					if (nrsm && nrsm->r_in_tmap)
9392 						rack_log_sack_passed(tp, rack, nrsm, cts);
9393 				}
9394 				/* Now are we done? */
9395 				if (SEQ_LT(end, next->r_end) ||
9396 				    (end == next->r_end)) {
9397 					/* Done with block */
9398 					goto out;
9399 				}
9400 				rack_log_map_chg(tp, rack, &stack_map, rsm, next, MAP_SACK_M1, end, __LINE__);
9401 				/* Postion for the next block */
9402 				start = next->r_end;
9403 				rsm = tqhash_next(rack->r_ctl.tqh, next);
9404 				if (rsm == NULL)
9405 					goto out;
9406 			} else {
9407 				/**
9408 				 * We can't use any hookery here, so we
9409 				 * need to split the map. We enter like
9410 				 * so:
9411 				 *  rsm      |--------|
9412 				 *  sackblk       |----->
9413 				 * We will add the new block nrsm and
9414 				 * that will be the new portion, and then
9415 				 * fall through after reseting rsm. So we
9416 				 * split and look like this:
9417 				 *  rsm      |----|
9418 				 *  sackblk       |----->
9419 				 *  nrsm          |---|
9420 				 * We then fall through reseting
9421 				 * rsm to nrsm, so the next block
9422 				 * picks it up.
9423 				 */
9424 				nrsm = rack_alloc_limit(rack, RACK_LIMIT_TYPE_SPLIT);
9425 				if (nrsm == NULL) {
9426 					/*
9427 					 * failed XXXrrs what can we do but loose the sack
9428 					 * info?
9429 					 */
9430 					goto out;
9431 				}
9432 				rack_clone_rsm(rack, nrsm, rsm, start);
9433 				rsm->r_just_ret = 0;
9434 #ifndef INVARIANTS
9435 				(void)tqhash_insert(rack->r_ctl.tqh, nrsm);
9436 #else
9437 				if ((insret = tqhash_insert(rack->r_ctl.tqh, nrsm)) != 0) {
9438 					panic("Insert in tailq_hash of %p fails ret:%d rack:%p rsm:%p",
9439 					      nrsm, insret, rack, rsm);
9440 				}
9441 #endif
9442 				if (rsm->r_in_tmap) {
9443 					TAILQ_INSERT_AFTER(&rack->r_ctl.rc_tmap, rsm, nrsm, r_tnext);
9444 					nrsm->r_in_tmap = 1;
9445 				}
9446 				rack_log_map_chg(tp, rack, NULL, rsm, nrsm, MAP_SACK_M2, end, __LINE__);
9447 				rsm->r_flags &= (~RACK_HAS_FIN);
9448 				/* Position us to point to the new nrsm that starts the sack blk */
9449 				rsm = nrsm;
9450 			}
9451 		} else {
9452 			/* Already sacked this piece */
9453 			if (end == rsm->r_end) {
9454 				/* Done with block */
9455 				rsm = tqhash_next(rack->r_ctl.tqh, rsm);
9456 				goto out;
9457 			} else if (SEQ_LT(end, rsm->r_end)) {
9458 				/* A partial sack to a already sacked block */
9459 				rsm = tqhash_next(rack->r_ctl.tqh, rsm);
9460 				goto out;
9461 			} else {
9462 				/*
9463 				 * The end goes beyond this guy
9464 				 * reposition the start to the
9465 				 * next block.
9466 				 */
9467 				start = rsm->r_end;
9468 				rsm = tqhash_next(rack->r_ctl.tqh, rsm);
9469 				if (rsm == NULL)
9470 					goto out;
9471 			}
9472 		}
9473 	}
9474 	if (SEQ_GEQ(end, rsm->r_end)) {
9475 		/**
9476 		 * The end of this block is either beyond this guy or right
9477 		 * at this guy. I.e.:
9478 		 *  rsm ---                 |-----|
9479 		 *  end                     |-----|
9480 		 *  <or>
9481 		 *  end                     |---------|
9482 		 */
9483 		if ((rsm->r_flags & RACK_ACKED) == 0) {
9484 			/*
9485 			 * Is it a TLP of interest?
9486 			 */
9487 			if ((rsm->r_flags & RACK_TLP) &&
9488 			    (rsm->r_rtr_cnt > 1)) {
9489 				/*
9490 				 * We are splitting a rxt TLP, check
9491 				 * if we need to save off the start/end
9492 				 */
9493 				if (rack->rc_last_tlp_acked_set &&
9494 				    (is_rsm_inside_declared_tlp_block(rack, rsm))) {
9495 					/*
9496 					 * We already turned this on since we are inside
9497 					 * the previous one was a partially sack now we
9498 					 * are getting another one (maybe all of it).
9499 					 */
9500 					rack_log_dsack_event(rack, 10, __LINE__, rsm->r_start, rsm->r_end);
9501 					/*
9502 					 * Lets make sure we have all of it though.
9503 					 */
9504 					if (SEQ_LT(rsm->r_start, rack->r_ctl.last_tlp_acked_start)) {
9505 						rack->r_ctl.last_tlp_acked_start = rsm->r_start;
9506 						rack_log_dsack_event(rack, 11, __LINE__, rack->r_ctl.last_tlp_acked_start,
9507 								     rack->r_ctl.last_tlp_acked_end);
9508 					}
9509 					if (SEQ_GT(rsm->r_end, rack->r_ctl.last_tlp_acked_end)) {
9510 						rack->r_ctl.last_tlp_acked_end = rsm->r_end;
9511 						rack_log_dsack_event(rack, 11, __LINE__, rack->r_ctl.last_tlp_acked_start,
9512 								     rack->r_ctl.last_tlp_acked_end);
9513 					}
9514 				} else {
9515 					rack->r_ctl.last_tlp_acked_start = rsm->r_start;
9516 					rack->r_ctl.last_tlp_acked_end = rsm->r_end;
9517 					rack->rc_last_tlp_past_cumack = 0;
9518 					rack->rc_last_tlp_acked_set = 1;
9519 					rack_log_dsack_event(rack, 8, __LINE__, rsm->r_start, rsm->r_end);
9520 				}
9521 			}
9522 			rack_update_rtt(tp, rack, rsm, to, cts, SACKED, 0);
9523 			changed += (rsm->r_end - rsm->r_start);
9524 			/* You get a count for acking a whole segment or more */
9525 			if (rsm->r_flags & RACK_WAS_LOST) {
9526 				/*
9527 				 * Here we can use the inline function since
9528 				 * the rsm is truly marked lost and now no longer lost.
9529 				 */
9530 				rack_mark_nolonger_lost(rack, rsm);
9531 			}
9532 			rack->r_ctl.rc_sacked += (rsm->r_end - rsm->r_start);
9533 			if (rsm->r_in_tmap) /* should be true */
9534 				rack_log_sack_passed(tp, rack, rsm, cts);
9535 			/* Is Reordering occuring? */
9536 			if (rsm->r_flags & RACK_SACK_PASSED) {
9537 				rsm->r_flags &= ~RACK_SACK_PASSED;
9538 				rack->r_ctl.rc_reorder_ts = cts;
9539 				if (rack->r_ctl.rc_reorder_ts == 0)
9540 					rack->r_ctl.rc_reorder_ts = 1;
9541 			}
9542 			if (rack->app_limited_needs_set)
9543 				rack_need_set_test(tp, rack, rsm, tp->snd_una, __LINE__, RACK_USE_END);
9544 			rsm->r_ack_arrival = rack_to_usec_ts(&rack->r_ctl.act_rcv_time);
9545 			rsm->r_flags |= RACK_ACKED;
9546 			rack_update_pcm_ack(rack, 0, rsm->r_start, rsm->r_end);
9547 			if (rsm->r_in_tmap) {
9548 				TAILQ_REMOVE(&rack->r_ctl.rc_tmap, rsm, r_tnext);
9549 				rsm->r_in_tmap = 0;
9550 			}
9551 			rack_log_map_chg(tp, rack, NULL, rsm, NULL, MAP_SACK_M3, end, __LINE__);
9552 		}
9553 		if (end == rsm->r_end) {
9554 			/* This block only - done, setup for next */
9555 			goto out;
9556 		}
9557 		/*
9558 		 * There is more not coverend by this rsm move on
9559 		 * to the next block in the tail queue hash table.
9560 		 */
9561 		nrsm = tqhash_next(rack->r_ctl.tqh, rsm);
9562 		start = rsm->r_end;
9563 		rsm = nrsm;
9564 		if (rsm == NULL)
9565 			goto out;
9566 		goto do_rest_ofb;
9567 	}
9568 	/**
9569 	 * The end of this sack block is smaller than
9570 	 * our rsm i.e.:
9571 	 *  rsm ---                 |-----|
9572 	 *  end                     |--|
9573 	 */
9574 	if ((rsm->r_flags & RACK_ACKED) == 0) {
9575 		/*
9576 		 * Is it a TLP of interest?
9577 		 */
9578 		if ((rsm->r_flags & RACK_TLP) &&
9579 		    (rsm->r_rtr_cnt > 1)) {
9580 			/*
9581 			 * We are splitting a rxt TLP, check
9582 			 * if we need to save off the start/end
9583 			 */
9584 			if (rack->rc_last_tlp_acked_set &&
9585 			    (is_rsm_inside_declared_tlp_block(rack, rsm))) {
9586 				/*
9587 				 * We already turned this on since we are inside
9588 				 * the previous one was a partially sack now we
9589 				 * are getting another one (maybe all of it).
9590 				 */
9591 				rack_log_dsack_event(rack, 10, __LINE__, rsm->r_start, rsm->r_end);
9592 				/*
9593 				 * Lets make sure we have all of it though.
9594 				 */
9595 				if (SEQ_LT(rsm->r_start, rack->r_ctl.last_tlp_acked_start)) {
9596 					rack->r_ctl.last_tlp_acked_start = rsm->r_start;
9597 					rack_log_dsack_event(rack, 11, __LINE__, rack->r_ctl.last_tlp_acked_start,
9598 							     rack->r_ctl.last_tlp_acked_end);
9599 				}
9600 				if (SEQ_GT(rsm->r_end, rack->r_ctl.last_tlp_acked_end)) {
9601 					rack->r_ctl.last_tlp_acked_end = rsm->r_end;
9602 					rack_log_dsack_event(rack, 11, __LINE__, rack->r_ctl.last_tlp_acked_start,
9603 							     rack->r_ctl.last_tlp_acked_end);
9604 				}
9605 			} else {
9606 				rack->r_ctl.last_tlp_acked_start = rsm->r_start;
9607 				rack->r_ctl.last_tlp_acked_end = rsm->r_end;
9608 				rack->rc_last_tlp_past_cumack = 0;
9609 				rack->rc_last_tlp_acked_set = 1;
9610 				rack_log_dsack_event(rack, 8, __LINE__, rsm->r_start, rsm->r_end);
9611 			}
9612 		}
9613 		/*
9614 		 * Hookery can only be used if the two entries
9615 		 * are in the same bucket and neither one of
9616 		 * them staddle the bucket line.
9617 		 */
9618 		prev = tqhash_prev(rack->r_ctl.tqh, rsm);
9619 		if (prev &&
9620 		    (rsm->bindex == prev->bindex) &&
9621 		    ((rsm->r_flags & RACK_STRADDLE) == 0) &&
9622 		    ((prev->r_flags & RACK_STRADDLE) == 0) &&
9623 		    ((rsm->r_flags & RACK_IS_PCM) == 0) &&
9624 		    ((prev->r_flags & RACK_IS_PCM) == 0) &&
9625 		    (rsm->r_flags & RACK_IN_GP_WIN) &&
9626 		    (prev->r_flags & RACK_IN_GP_WIN))
9627 			can_use_hookery = 1;
9628 		else
9629 			can_use_hookery = 0;
9630 		if (prev && can_use_hookery &&
9631 		    (prev->r_flags & RACK_ACKED)) {
9632 			/**
9633 			 * Goal, we want the right remainder of rsm to shrink
9634 			 * in place and span from (rsm->r_start = end) to rsm->r_end.
9635 			 * We want to expand prev to go all the way
9636 			 * to prev->r_end <- end.
9637 			 * so in the tree we have before:
9638 			 *   prev     |--------|         (acked)
9639 			 *   rsm               |-------| (non-acked)
9640 			 *   sackblk           |-|
9641 			 * We churn it so we end up with
9642 			 *   prev     |----------|       (acked)
9643 			 *   rsm                 |-----| (non-acked)
9644 			 *   nrsm              |-| (temporary)
9645 			 *
9646 			 * Note if either prev/rsm is a TLP we don't
9647 			 * do this.
9648 			 */
9649 			nrsm = &stack_map;
9650 			memcpy(nrsm, rsm, sizeof(struct rack_sendmap));
9651 			tqhash_update_end(rack->r_ctl.tqh, prev, end);
9652 			rsm->r_start = end;
9653 			rsm->r_flags |= RACK_SHUFFLED;
9654 			prev->r_flags |= RACK_SHUFFLED;
9655 			/* Now adjust nrsm (stack copy) to be
9656 			 * the one that is the small
9657 			 * piece that was "sacked".
9658 			 */
9659 			nrsm->r_end = end;
9660 			rsm->r_dupack = 0;
9661 			/*
9662 			 * Which timestamp do we keep? It is rather
9663 			 * important in GP measurements to have the
9664 			 * accurate end of the send window.
9665 			 *
9666 			 * We keep the largest value, which is the newest
9667 			 * send. We do this in case a segment that is
9668 			 * joined together and not part of a GP estimate
9669 			 * later gets expanded into the GP estimate.
9670 			 *
9671 			 * We prohibit the merging of unlike kinds i.e.
9672 			 * all pieces that are in the GP estimate can be
9673 			 * merged and all pieces that are not in a GP estimate
9674 			 * can be merged, but not disimilar pieces. Combine
9675 			 * this with taking the highest here and we should
9676 			 * be ok unless of course the client reneges. Then
9677 			 * all bets are off.
9678 			 */
9679 			if(prev->r_tim_lastsent[(prev->r_rtr_cnt-1)] <
9680 			   nrsm->r_tim_lastsent[(nrsm->r_rtr_cnt-1)]) {
9681 				prev->r_tim_lastsent[(prev->r_rtr_cnt-1)] = nrsm->r_tim_lastsent[(rsm->r_rtr_cnt-1)];
9682 			}
9683 			/*
9684 			 * And we must keep the newest ack arrival time.
9685 			 */
9686 
9687 			if(prev->r_ack_arrival <
9688 			   rack_to_usec_ts(&rack->r_ctl.act_rcv_time))
9689 				prev->r_ack_arrival = rack_to_usec_ts(&rack->r_ctl.act_rcv_time);
9690 
9691 			rack_log_retran_reason(rack, rsm, __LINE__, 0, 2);
9692 			/*
9693 			 * Now that the rsm has had its start moved forward
9694 			 * lets go ahead and get its new place in the world.
9695 			 */
9696 			rack_setup_offset_for_rsm(rack, prev, rsm);
9697 			/*
9698 			 * Now nrsm is our new little piece
9699 			 * that is acked (which was merged
9700 			 * to prev). Update the rtt and changed
9701 			 * based on that. Also check for reordering.
9702 			 */
9703 			rack_update_rtt(tp, rack, nrsm, to, cts, SACKED, 0);
9704 			if (rack->app_limited_needs_set)
9705 				rack_need_set_test(tp, rack, nrsm, tp->snd_una, __LINE__, RACK_USE_END);
9706 			changed += (nrsm->r_end - nrsm->r_start);
9707 			rack->r_ctl.rc_sacked += (nrsm->r_end - nrsm->r_start);
9708 			if (rsm->r_flags & RACK_WAS_LOST) {
9709 				int my_chg;
9710 
9711 				/*
9712 				 * Note here we are using hookery again so we can't
9713 				 * use our rack_mark_nolonger_lost() function.
9714 				 */
9715 				my_chg = (nrsm->r_end - nrsm->r_start);
9716 				KASSERT((rack->r_ctl.rc_considered_lost >= my_chg),
9717 					("rsm:%p rack:%p rc_considered_lost goes negative", rsm,  rack));
9718 				if (my_chg <= rack->r_ctl.rc_considered_lost)
9719 					rack->r_ctl.rc_considered_lost -= my_chg;
9720 				else
9721 					rack->r_ctl.rc_considered_lost = 0;
9722 			}
9723 			if (nrsm->r_flags & RACK_SACK_PASSED) {
9724 				rack->r_ctl.rc_reorder_ts = cts;
9725 				if (rack->r_ctl.rc_reorder_ts == 0)
9726 					rack->r_ctl.rc_reorder_ts = 1;
9727 			}
9728 			rack_log_map_chg(tp, rack, prev, &stack_map, rsm, MAP_SACK_M4, end, __LINE__);
9729 			rsm = prev;
9730 		} else {
9731 			/**
9732 			 * This is the case where our previous
9733 			 * block is not acked either, so we must
9734 			 * split the block in two.
9735 			 */
9736 			nrsm = rack_alloc_limit(rack, RACK_LIMIT_TYPE_SPLIT);
9737 			if (nrsm == NULL) {
9738 				/* failed rrs what can we do but loose the sack info? */
9739 				goto out;
9740 			}
9741 			if ((rsm->r_flags & RACK_TLP) &&
9742 			    (rsm->r_rtr_cnt > 1)) {
9743 				/*
9744 				 * We are splitting a rxt TLP, check
9745 				 * if we need to save off the start/end
9746 				 */
9747 				if (rack->rc_last_tlp_acked_set &&
9748 				    (is_rsm_inside_declared_tlp_block(rack, rsm))) {
9749 					/*
9750 					 * We already turned this on since this block is inside
9751 					 * the previous one was a partially sack now we
9752 					 * are getting another one (maybe all of it).
9753 					 */
9754 					rack_log_dsack_event(rack, 10, __LINE__, rsm->r_start, rsm->r_end);
9755 					/*
9756 					 * Lets make sure we have all of it though.
9757 					 */
9758 					if (SEQ_LT(rsm->r_start, rack->r_ctl.last_tlp_acked_start)) {
9759 						rack->r_ctl.last_tlp_acked_start = rsm->r_start;
9760 						rack_log_dsack_event(rack, 11, __LINE__, rack->r_ctl.last_tlp_acked_start,
9761 								     rack->r_ctl.last_tlp_acked_end);
9762 					}
9763 					if (SEQ_GT(rsm->r_end, rack->r_ctl.last_tlp_acked_end)) {
9764 						rack->r_ctl.last_tlp_acked_end = rsm->r_end;
9765 						rack_log_dsack_event(rack, 11, __LINE__, rack->r_ctl.last_tlp_acked_start,
9766 								     rack->r_ctl.last_tlp_acked_end);
9767 					}
9768 				} else {
9769 					rack->r_ctl.last_tlp_acked_start = rsm->r_start;
9770 					rack->r_ctl.last_tlp_acked_end = rsm->r_end;
9771 					rack->rc_last_tlp_acked_set = 1;
9772 					rack->rc_last_tlp_past_cumack = 0;
9773 					rack_log_dsack_event(rack, 8, __LINE__, rsm->r_start, rsm->r_end);
9774 				}
9775 			}
9776 			/**
9777 			 * In this case nrsm becomes
9778 			 * nrsm->r_start = end;
9779 			 * nrsm->r_end = rsm->r_end;
9780 			 * which is un-acked.
9781 			 * <and>
9782 			 * rsm->r_end = nrsm->r_start;
9783 			 * i.e. the remaining un-acked
9784 			 * piece is left on the left
9785 			 * hand side.
9786 			 *
9787 			 * So we start like this
9788 			 * rsm      |----------| (not acked)
9789 			 * sackblk  |---|
9790 			 * build it so we have
9791 			 * rsm      |---|         (acked)
9792 			 * nrsm         |------|  (not acked)
9793 			 */
9794 			rack_clone_rsm(rack, nrsm, rsm, end);
9795 			rsm->r_flags &= (~RACK_HAS_FIN);
9796 			rsm->r_just_ret = 0;
9797 #ifndef INVARIANTS
9798 			(void)tqhash_insert(rack->r_ctl.tqh, nrsm);
9799 #else
9800 			if ((insret = tqhash_insert(rack->r_ctl.tqh, nrsm)) != 0) {
9801 				panic("Insert in tailq_hash of %p fails ret:% rack:%p rsm:%p",
9802 				      nrsm, insret, rack, rsm);
9803 			}
9804 #endif
9805 			if (rsm->r_in_tmap) {
9806 				TAILQ_INSERT_AFTER(&rack->r_ctl.rc_tmap, rsm, nrsm, r_tnext);
9807 				nrsm->r_in_tmap = 1;
9808 			}
9809 			nrsm->r_dupack = 0;
9810 			rack_log_retran_reason(rack, nrsm, __LINE__, 0, 2);
9811 			rack_update_rtt(tp, rack, rsm, to, cts, SACKED, 0);
9812 			changed += (rsm->r_end - rsm->r_start);
9813 			if (rsm->r_flags & RACK_WAS_LOST) {
9814 				/*
9815 				 * Here it is safe to use our function.
9816 				 */
9817 				rack_mark_nolonger_lost(rack, rsm);
9818 			}
9819 			rack->r_ctl.rc_sacked += (rsm->r_end - rsm->r_start);
9820 
9821 			if (rsm->r_in_tmap) /* should be true */
9822 				rack_log_sack_passed(tp, rack, rsm, cts);
9823 			/* Is Reordering occuring? */
9824 			if (rsm->r_flags & RACK_SACK_PASSED) {
9825 				rsm->r_flags &= ~RACK_SACK_PASSED;
9826 				rack->r_ctl.rc_reorder_ts = cts;
9827 				if (rack->r_ctl.rc_reorder_ts == 0)
9828 					rack->r_ctl.rc_reorder_ts = 1;
9829 			}
9830 			if (rack->app_limited_needs_set)
9831 				rack_need_set_test(tp, rack, rsm, tp->snd_una, __LINE__, RACK_USE_END);
9832 			rsm->r_ack_arrival = rack_to_usec_ts(&rack->r_ctl.act_rcv_time);
9833 			rsm->r_flags |= RACK_ACKED;
9834 			rack_update_pcm_ack(rack, 0, rsm->r_start, rsm->r_end);
9835 			rack_log_map_chg(tp, rack, NULL, rsm, nrsm, MAP_SACK_M5, end, __LINE__);
9836 			if (rsm->r_in_tmap) {
9837 				TAILQ_REMOVE(&rack->r_ctl.rc_tmap, rsm, r_tnext);
9838 				rsm->r_in_tmap = 0;
9839 			}
9840 		}
9841 	}
9842 out:
9843 	if (rsm &&
9844 	    ((rsm->r_flags & RACK_TLP) == 0) &&
9845 	    (rsm->r_flags & RACK_ACKED)) {
9846 		/*
9847 		 * Now can we merge where we worked
9848 		 * with either the previous or
9849 		 * next block?
9850 		 */
9851 		next = tqhash_next(rack->r_ctl.tqh, rsm);
9852 		while (next) {
9853 			if (next->r_flags & RACK_TLP)
9854 				break;
9855 			/* Only allow merges between ones in or out of GP window */
9856 			if ((next->r_flags & RACK_IN_GP_WIN) &&
9857 			    ((rsm->r_flags & RACK_IN_GP_WIN) == 0)) {
9858 				break;
9859 			}
9860 			if ((rsm->r_flags & RACK_IN_GP_WIN) &&
9861 			    ((next->r_flags & RACK_IN_GP_WIN) == 0)) {
9862 				break;
9863 			}
9864 			if (rsm->bindex != next->bindex)
9865 				break;
9866 			if (rsm->r_flags & RACK_STRADDLE)
9867 				break;
9868 			if (rsm->r_flags & RACK_IS_PCM)
9869 				break;
9870 			if (next->r_flags & RACK_STRADDLE)
9871 				break;
9872 			if (next->r_flags & RACK_IS_PCM)
9873 				break;
9874 			if (next->r_flags & RACK_ACKED) {
9875 				/* yep this and next can be merged */
9876 				rsm = rack_merge_rsm(rack, rsm, next);
9877 				next = tqhash_next(rack->r_ctl.tqh, rsm);
9878 			} else
9879 				break;
9880 		}
9881 		/* Now what about the previous? */
9882 		prev = tqhash_prev(rack->r_ctl.tqh, rsm);
9883 		while (prev) {
9884 			if (prev->r_flags & RACK_TLP)
9885 				break;
9886 			/* Only allow merges between ones in or out of GP window */
9887 			if ((prev->r_flags & RACK_IN_GP_WIN) &&
9888 			    ((rsm->r_flags & RACK_IN_GP_WIN) == 0)) {
9889 				break;
9890 			}
9891 			if ((rsm->r_flags & RACK_IN_GP_WIN) &&
9892 			    ((prev->r_flags & RACK_IN_GP_WIN) == 0)) {
9893 				break;
9894 			}
9895 			if (rsm->bindex != prev->bindex)
9896 				break;
9897 			if (rsm->r_flags & RACK_STRADDLE)
9898 				break;
9899 			if (rsm->r_flags & RACK_IS_PCM)
9900 				break;
9901 			if (prev->r_flags & RACK_STRADDLE)
9902 				break;
9903 			if (prev->r_flags & RACK_IS_PCM)
9904 				break;
9905 			if (prev->r_flags & RACK_ACKED) {
9906 				/* yep the previous and this can be merged */
9907 				rsm = rack_merge_rsm(rack, prev, rsm);
9908 				prev = tqhash_prev(rack->r_ctl.tqh, rsm);
9909 			} else
9910 				break;
9911 		}
9912 	}
9913 	if (used_ref == 0) {
9914 		counter_u64_add(rack_sack_proc_all, 1);
9915 	} else {
9916 		counter_u64_add(rack_sack_proc_short, 1);
9917 	}
9918 	/* Save off the next one for quick reference. */
9919 	nrsm = tqhash_find(rack->r_ctl.tqh, end);
9920 	*prsm = rack->r_ctl.rc_sacklast = nrsm;
9921 	return (changed);
9922 }
9923 
9924 static void inline
9925 rack_peer_reneges(struct tcp_rack *rack, struct rack_sendmap *rsm, tcp_seq th_ack)
9926 {
9927 	struct rack_sendmap *tmap;
9928 
9929 	tmap = NULL;
9930 	while (rsm && (rsm->r_flags & RACK_ACKED)) {
9931 		/* Its no longer sacked, mark it so */
9932 		rack->r_ctl.rc_sacked -= (rsm->r_end - rsm->r_start);
9933 #ifdef INVARIANTS
9934 		if (rsm->r_in_tmap) {
9935 			panic("rack:%p rsm:%p flags:0x%x in tmap?",
9936 			      rack, rsm, rsm->r_flags);
9937 		}
9938 #endif
9939 		rsm->r_flags &= ~(RACK_ACKED|RACK_SACK_PASSED|RACK_WAS_SACKPASS);
9940 		/* Rebuild it into our tmap */
9941 		if (tmap == NULL) {
9942 			TAILQ_INSERT_HEAD(&rack->r_ctl.rc_tmap, rsm, r_tnext);
9943 			tmap = rsm;
9944 		} else {
9945 			TAILQ_INSERT_AFTER(&rack->r_ctl.rc_tmap, tmap, rsm, r_tnext);
9946 			tmap = rsm;
9947 		}
9948 		tmap->r_in_tmap = 1;
9949 		rsm = tqhash_next(rack->r_ctl.tqh, rsm);
9950 	}
9951 	/*
9952 	 * Now lets possibly clear the sack filter so we start
9953 	 * recognizing sacks that cover this area.
9954 	 */
9955 	sack_filter_clear(&rack->r_ctl.rack_sf, th_ack);
9956 
9957 }
9958 
9959 
9960 static void inline
9961 rack_rsm_sender_update(struct tcp_rack *rack, struct tcpcb *tp, struct rack_sendmap *rsm, uint8_t from)
9962 {
9963 	/*
9964 	 * We look at advancing the end send time for our GP
9965 	 * measurement tracking only as the cumulative acknowledgment
9966 	 * moves forward. You might wonder about this, why not
9967 	 * at every transmission or retransmission within the
9968 	 * GP window update the rc_gp_cumack_ts? Well its rather
9969 	 * nuanced but basically the GP window *may* expand (as
9970 	 * it does below) or worse and harder to track it may shrink.
9971 	 *
9972 	 * This last makes it impossible to track at the time of
9973 	 * the send, since you may set forward your rc_gp_cumack_ts
9974 	 * when you send, because that send *is* in your currently
9975 	 * "guessed" window, but then it shrinks. Now which was
9976 	 * the send time of the last bytes in the window, by the
9977 	 * time you ask that question that part of the sendmap
9978 	 * is freed. So you don't know and you will have too
9979 	 * long of send window. Instead by updating the time
9980 	 * marker only when the cumack advances this assures us
9981 	 * that we will have only the sends in the window of our
9982 	 * GP measurement.
9983 	 *
9984 	 * Another complication from this is the
9985 	 * merging of sendmap entries. During SACK processing this
9986 	 * can happen to conserve the sendmap size. That breaks
9987 	 * everything down in tracking the send window of the GP
9988 	 * estimate. So to prevent that and keep it working with
9989 	 * a tiny bit more limited merging, we only allow like
9990 	 * types to be merged. I.e. if two sends are in the GP window
9991 	 * then its ok to merge them together. If two sends are not
9992 	 * in the GP window its ok to merge them together too. Though
9993 	 * one send in and one send out cannot be merged. We combine
9994 	 * this with never allowing the shrinking of the GP window when
9995 	 * we are in recovery so that we can properly calculate the
9996 	 * sending times.
9997 	 *
9998 	 * This all of course seems complicated, because it is.. :)
9999 	 *
10000 	 * The cum-ack is being advanced upon the sendmap.
10001 	 * If we are not doing a GP estimate don't
10002 	 * proceed.
10003 	 */
10004 	uint64_t ts;
10005 
10006 	if ((tp->t_flags & TF_GPUTINPROG) == 0)
10007 		return;
10008 	/*
10009 	 * If this sendmap entry is going
10010 	 * beyond the measurement window we had picked,
10011 	 * expand the measurement window by that much.
10012 	 */
10013 	if (SEQ_GT(rsm->r_end, tp->gput_ack)) {
10014 		tp->gput_ack = rsm->r_end;
10015 	}
10016 	/*
10017 	 * If we have not setup a ack, then we
10018 	 * have no idea if the newly acked pieces
10019 	 * will be "in our seq measurement range". If
10020 	 * it is when we clear the app_limited_needs_set
10021 	 * flag the timestamp will be updated.
10022 	 */
10023 	if (rack->app_limited_needs_set)
10024 		return;
10025 	/*
10026 	 * Finally, we grab out the latest timestamp
10027 	 * that this packet was sent and then see
10028 	 * if:
10029 	 *  a) The packet touches are newly defined GP range.
10030 	 *  b) The time is greater than (newer) than the
10031 	 *     one we currently have. If so we update
10032 	 *     our sending end time window.
10033 	 *
10034 	 * Note we *do not* do this at send time. The reason
10035 	 * is that if you do you *may* pick up a newer timestamp
10036 	 * for a range you are not going to measure. We project
10037 	 * out how far and then sometimes modify that to be
10038 	 * smaller. If that occurs then you will have a send
10039 	 * that does not belong to the range included.
10040 	 */
10041 	if ((ts = rsm->r_tim_lastsent[(rsm->r_rtr_cnt-1)]) <=
10042 	    rack->r_ctl.rc_gp_cumack_ts)
10043 		return;
10044 	if (rack_in_gp_window(tp, rsm)) {
10045 		rack->r_ctl.rc_gp_cumack_ts = ts;
10046 		rack_log_gpset(rack, tp->gput_ack, (uint32_t)ts, rsm->r_end,
10047 			       __LINE__, from, rsm);
10048 	}
10049 }
10050 
10051 static void
10052 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)
10053 {
10054 	struct rack_sendmap *rsm;
10055 	/*
10056 	 * The ACK point is advancing to th_ack, we must drop off
10057 	 * the packets in the rack log and calculate any eligble
10058 	 * RTT's.
10059 	 */
10060 
10061 	if (sack_filter_blks_used(&rack->r_ctl.rack_sf)) {
10062 		/*
10063 		 * If we have some sack blocks in the filter
10064 		 * lets prune them out by calling sfb with no blocks.
10065 		 */
10066 		sack_filter_blks(tp, &rack->r_ctl.rack_sf, NULL, 0, th_ack);
10067 	}
10068 	if (SEQ_GT(th_ack, tp->snd_una)) {
10069 		/* Clear any app ack remembered settings */
10070 		rack->r_ctl.cleared_app_ack = 0;
10071 	}
10072 	rack->r_wanted_output = 1;
10073 	if (SEQ_GT(th_ack, tp->snd_una))
10074 		rack->r_ctl.last_cumack_advance = acktime;
10075 
10076 	/* Tend any TLP that has been marked for 1/2 the seq space (its old)  */
10077 	if ((rack->rc_last_tlp_acked_set == 1)&&
10078 	    (rack->rc_last_tlp_past_cumack == 1) &&
10079 	    (SEQ_GT(rack->r_ctl.last_tlp_acked_start, th_ack))) {
10080 		/*
10081 		 * We have reached the point where our last rack
10082 		 * tlp retransmit sequence is ahead of the cum-ack.
10083 		 * This can only happen when the cum-ack moves all
10084 		 * the way around (its been a full 2^^31+1 bytes
10085 		 * or more since we sent a retransmitted TLP). Lets
10086 		 * turn off the valid flag since its not really valid.
10087 		 *
10088 		 * Note since sack's also turn on this event we have
10089 		 * a complication, we have to wait to age it out until
10090 		 * the cum-ack is by the TLP before checking which is
10091 		 * what the next else clause does.
10092 		 */
10093 		rack_log_dsack_event(rack, 9, __LINE__,
10094 				     rack->r_ctl.last_tlp_acked_start,
10095 				     rack->r_ctl.last_tlp_acked_end);
10096 		rack->rc_last_tlp_acked_set = 0;
10097 		rack->rc_last_tlp_past_cumack = 0;
10098 	} else if ((rack->rc_last_tlp_acked_set == 1) &&
10099 		   (rack->rc_last_tlp_past_cumack == 0) &&
10100 		   (SEQ_GEQ(th_ack, rack->r_ctl.last_tlp_acked_end))) {
10101 		/*
10102 		 * It is safe to start aging TLP's out.
10103 		 */
10104 		rack->rc_last_tlp_past_cumack = 1;
10105 	}
10106 	/* We do the same for the tlp send seq as well */
10107 	if ((rack->rc_last_sent_tlp_seq_valid == 1) &&
10108 	    (rack->rc_last_sent_tlp_past_cumack == 1) &&
10109 	    (SEQ_GT(rack->r_ctl.last_sent_tlp_seq,  th_ack))) {
10110 		rack_log_dsack_event(rack, 9, __LINE__,
10111 				     rack->r_ctl.last_sent_tlp_seq,
10112 				     (rack->r_ctl.last_sent_tlp_seq +
10113 				      rack->r_ctl.last_sent_tlp_len));
10114 		rack->rc_last_sent_tlp_seq_valid = 0;
10115 		rack->rc_last_sent_tlp_past_cumack = 0;
10116 	} else if ((rack->rc_last_sent_tlp_seq_valid == 1) &&
10117 		   (rack->rc_last_sent_tlp_past_cumack == 0) &&
10118 		   (SEQ_GEQ(th_ack, rack->r_ctl.last_sent_tlp_seq))) {
10119 		/*
10120 		 * It is safe to start aging TLP's send.
10121 		 */
10122 		rack->rc_last_sent_tlp_past_cumack = 1;
10123 	}
10124 more:
10125 	rsm = tqhash_min(rack->r_ctl.tqh);
10126 	if (rsm == NULL) {
10127 		if ((th_ack - 1) == tp->iss) {
10128 			/*
10129 			 * For the SYN incoming case we will not
10130 			 * have called tcp_output for the sending of
10131 			 * the SYN, so there will be no map. All
10132 			 * other cases should probably be a panic.
10133 			 */
10134 			return;
10135 		}
10136 		if (tp->t_flags & TF_SENTFIN) {
10137 			/* if we sent a FIN we often will not have map */
10138 			return;
10139 		}
10140 #ifdef INVARIANTS
10141 		panic("No rack map tp:%p for state:%d ack:%u rack:%p snd_una:%u snd_max:%u\n",
10142 		      tp,
10143 		      tp->t_state, th_ack, rack,
10144 		      tp->snd_una, tp->snd_max);
10145 #endif
10146 		return;
10147 	}
10148 	if (SEQ_LT(th_ack, rsm->r_start)) {
10149 		/* Huh map is missing this */
10150 #ifdef INVARIANTS
10151 		printf("Rack map starts at r_start:%u for th_ack:%u huh? ts:%d rs:%d\n",
10152 		       rsm->r_start,
10153 		       th_ack, tp->t_state, rack->r_state);
10154 #endif
10155 		return;
10156 	}
10157 	rack_update_rtt(tp, rack, rsm, to, cts, CUM_ACKED, th_ack);
10158 
10159 	/* Now was it a retransmitted TLP? */
10160 	if ((rsm->r_flags & RACK_TLP) &&
10161 	    (rsm->r_rtr_cnt > 1)) {
10162 		/*
10163 		 * Yes, this rsm was a TLP and retransmitted, remember that
10164 		 * since if a DSACK comes back on this we don't want
10165 		 * to think of it as a reordered segment. This may
10166 		 * get updated again with possibly even other TLPs
10167 		 * in flight, but thats ok. Only when we don't send
10168 		 * a retransmitted TLP for 1/2 the sequences space
10169 		 * will it get turned off (above).
10170 		 */
10171 		if (rack->rc_last_tlp_acked_set &&
10172 		    (is_rsm_inside_declared_tlp_block(rack, rsm))) {
10173 			/*
10174 			 * We already turned this on since the end matches,
10175 			 * the previous one was a partially ack now we
10176 			 * are getting another one (maybe all of it).
10177 			 */
10178 			rack_log_dsack_event(rack, 10, __LINE__, rsm->r_start, rsm->r_end);
10179 			/*
10180 			 * Lets make sure we have all of it though.
10181 			 */
10182 			if (SEQ_LT(rsm->r_start, rack->r_ctl.last_tlp_acked_start)) {
10183 				rack->r_ctl.last_tlp_acked_start = rsm->r_start;
10184 				rack_log_dsack_event(rack, 11, __LINE__, rack->r_ctl.last_tlp_acked_start,
10185 						     rack->r_ctl.last_tlp_acked_end);
10186 			}
10187 			if (SEQ_GT(rsm->r_end, rack->r_ctl.last_tlp_acked_end)) {
10188 				rack->r_ctl.last_tlp_acked_end = rsm->r_end;
10189 				rack_log_dsack_event(rack, 11, __LINE__, rack->r_ctl.last_tlp_acked_start,
10190 						     rack->r_ctl.last_tlp_acked_end);
10191 			}
10192 		} else {
10193 			rack->rc_last_tlp_past_cumack = 1;
10194 			rack->r_ctl.last_tlp_acked_start = rsm->r_start;
10195 			rack->r_ctl.last_tlp_acked_end = rsm->r_end;
10196 			rack->rc_last_tlp_acked_set = 1;
10197 			rack_log_dsack_event(rack, 8, __LINE__, rsm->r_start, rsm->r_end);
10198 		}
10199 	}
10200 	/* Now do we consume the whole thing? */
10201 	rack->r_ctl.last_tmit_time_acked = rsm->r_tim_lastsent[(rsm->r_rtr_cnt - 1)];
10202 	if (SEQ_GEQ(th_ack, rsm->r_end)) {
10203 		/* Its all consumed. */
10204 		uint32_t left;
10205 		uint8_t newly_acked;
10206 
10207 		if (rsm->r_flags & RACK_WAS_LOST) {
10208 			/*
10209 			 * This can happen when we marked it as lost
10210 			 * and yet before retransmitting we get an ack
10211 			 * which can happen due to reordering.
10212 			 */
10213 			rack_mark_nolonger_lost(rack, rsm);
10214 		}
10215 		rack_log_map_chg(tp, rack, NULL, rsm, NULL, MAP_FREE, rsm->r_end, __LINE__);
10216 		rack->r_ctl.rc_holes_rxt -= rsm->r_rtr_bytes;
10217 		rsm->r_rtr_bytes = 0;
10218 		/*
10219 		 * Record the time of highest cumack sent if its in our measurement
10220 		 * window and possibly bump out the end.
10221 		 */
10222 		rack_rsm_sender_update(rack, tp, rsm, 4);
10223 		tqhash_remove(rack->r_ctl.tqh, rsm, REMOVE_TYPE_CUMACK);
10224 		if (rsm->r_in_tmap) {
10225 			TAILQ_REMOVE(&rack->r_ctl.rc_tmap, rsm, r_tnext);
10226 			rsm->r_in_tmap = 0;
10227 		}
10228 		newly_acked = 1;
10229 		if (rsm->r_flags & RACK_ACKED) {
10230 			/*
10231 			 * It was acked on the scoreboard -- remove
10232 			 * it from total
10233 			 */
10234 			rack->r_ctl.rc_sacked -= (rsm->r_end - rsm->r_start);
10235 			newly_acked = 0;
10236 		} else if (rsm->r_flags & RACK_SACK_PASSED) {
10237 			/*
10238 			 * There are segments ACKED on the
10239 			 * scoreboard further up. We are seeing
10240 			 * reordering.
10241 			 */
10242 			rsm->r_flags &= ~RACK_SACK_PASSED;
10243 			rsm->r_ack_arrival = rack_to_usec_ts(&rack->r_ctl.act_rcv_time);
10244 			rsm->r_flags |= RACK_ACKED;
10245 			rack->r_ctl.rc_reorder_ts = cts;
10246 			if (rack->r_ctl.rc_reorder_ts == 0)
10247 				rack->r_ctl.rc_reorder_ts = 1;
10248 			if (rack->r_ent_rec_ns) {
10249 				/*
10250 				 * We have sent no more, and we saw an sack
10251 				 * then ack arrive.
10252 				 */
10253 				rack->r_might_revert = 1;
10254 			}
10255 			rack_update_pcm_ack(rack, 1, rsm->r_start, rsm->r_end);
10256 		} else {
10257 			rack_update_pcm_ack(rack, 1, rsm->r_start, rsm->r_end);
10258 		}
10259 		if ((rsm->r_flags & RACK_TO_REXT) &&
10260 		    (tp->t_flags & TF_RCVD_TSTMP) &&
10261 		    (to->to_flags & TOF_TS) &&
10262 		    (to->to_tsecr != 0) &&
10263 		    (tp->t_flags & TF_PREVVALID)) {
10264 			/*
10265 			 * We can use the timestamp to see
10266 			 * if this retransmission was from the
10267 			 * first transmit. If so we made a mistake.
10268 			 */
10269 			tp->t_flags &= ~TF_PREVVALID;
10270 			if (to->to_tsecr == rack_ts_to_msec(rsm->r_tim_lastsent[0])) {
10271 				/* The first transmit is what this ack is for */
10272 				rack_cong_signal(tp, CC_RTO_ERR, th_ack, __LINE__);
10273 			}
10274 		}
10275 		left = th_ack - rsm->r_end;
10276 		if (rack->app_limited_needs_set && newly_acked)
10277 			rack_need_set_test(tp, rack, rsm, th_ack, __LINE__, RACK_USE_END_OR_THACK);
10278 		/* Free back to zone */
10279 		rack_free(rack, rsm);
10280 		if (left) {
10281 			goto more;
10282 		}
10283 		/* Check for reneging */
10284 		rsm = tqhash_min(rack->r_ctl.tqh);
10285 		if (rsm && (rsm->r_flags & RACK_ACKED) && (th_ack == rsm->r_start)) {
10286 			/*
10287 			 * The peer has moved snd_una up to
10288 			 * the edge of this send, i.e. one
10289 			 * that it had previously acked. The only
10290 			 * way that can be true if the peer threw
10291 			 * away data (space issues) that it had
10292 			 * previously sacked (else it would have
10293 			 * given us snd_una up to (rsm->r_end).
10294 			 * We need to undo the acked markings here.
10295 			 *
10296 			 * Note we have to look to make sure th_ack is
10297 			 * our rsm->r_start in case we get an old ack
10298 			 * where th_ack is behind snd_una.
10299 			 */
10300 			rack_peer_reneges(rack, rsm, th_ack);
10301 		}
10302 		return;
10303 	}
10304 	if (rsm->r_flags & RACK_ACKED) {
10305 		/*
10306 		 * It was acked on the scoreboard -- remove it from
10307 		 * total for the part being cum-acked.
10308 		 */
10309 		rack->r_ctl.rc_sacked -= (th_ack - rsm->r_start);
10310 	} else {
10311 		rack_update_pcm_ack(rack, 1, rsm->r_start, th_ack);
10312 	}
10313 	/* And what about the lost flag? */
10314 	if (rsm->r_flags & RACK_WAS_LOST) {
10315 		/*
10316 		 * This can happen when we marked it as lost
10317 		 * and yet before retransmitting we get an ack
10318 		 * which can happen due to reordering. In this
10319 		 * case its only a partial ack of the send.
10320 		 */
10321 		rack_mark_nolonger_lost(rack, rsm);
10322 	}
10323 	/*
10324 	 * Clear the dup ack count for
10325 	 * the piece that remains.
10326 	 */
10327 	rsm->r_dupack = 0;
10328 	rack_log_retran_reason(rack, rsm, __LINE__, 0, 2);
10329 	if (rsm->r_rtr_bytes) {
10330 		/*
10331 		 * It was retransmitted adjust the
10332 		 * sack holes for what was acked.
10333 		 */
10334 		int ack_am;
10335 
10336 		ack_am = (th_ack - rsm->r_start);
10337 		if (ack_am >= rsm->r_rtr_bytes) {
10338 			rack->r_ctl.rc_holes_rxt -= ack_am;
10339 			rsm->r_rtr_bytes -= ack_am;
10340 		}
10341 	}
10342 	/*
10343 	 * Update where the piece starts and record
10344 	 * the time of send of highest cumack sent if
10345 	 * its in our GP range.
10346 	 */
10347 	rack_log_map_chg(tp, rack, NULL, rsm, NULL, MAP_TRIM_HEAD, th_ack, __LINE__);
10348 	/* Now we need to move our offset forward too */
10349 	if (rsm->m &&
10350 	    ((rsm->orig_m_len != rsm->m->m_len) ||
10351 	     (M_TRAILINGROOM(rsm->m) != rsm->orig_t_space))) {
10352 		/* Fix up the orig_m_len and possibly the mbuf offset */
10353 		rack_adjust_orig_mlen(rsm);
10354 	}
10355 	rsm->soff += (th_ack - rsm->r_start);
10356 	rack_rsm_sender_update(rack, tp, rsm, 5);
10357 	/* The trim will move th_ack into r_start for us */
10358 	tqhash_trim(rack->r_ctl.tqh, th_ack);
10359 	/* Now do we need to move the mbuf fwd too? */
10360 	{
10361 		struct mbuf *m;
10362 		uint32_t soff;
10363 
10364 		m = rsm->m;
10365 		soff = rsm->soff;
10366 		if (m) {
10367 			while (soff >= m->m_len) {
10368 				soff -= m->m_len;
10369 				KASSERT((m->m_next != NULL),
10370 					(" rsm:%p  off:%u soff:%u m:%p",
10371 					 rsm, rsm->soff, soff, m));
10372 				m = m->m_next;
10373 				if (m == NULL) {
10374 					/*
10375 					 * This is a fall-back that prevents a panic. In reality
10376 					 * we should be able to walk the mbuf's and find our place.
10377 					 * At this point snd_una has not been updated with the sbcut() yet
10378 					 * but tqhash_trim did update rsm->r_start so the offset calcuation
10379 					 * should work fine. This is undesirable since we will take cache
10380 					 * hits to access the socket buffer. And even more puzzling is that
10381 					 * it happens occasionally. It should not :(
10382 					 */
10383 					m = sbsndmbuf(&rack->rc_inp->inp_socket->so_snd,
10384 						      (rsm->r_start - tp->snd_una),
10385 						      &soff);
10386 					break;
10387 				}
10388 			}
10389 			/*
10390 			 * Now save in our updated values.
10391 			 */
10392 			rsm->m = m;
10393 			rsm->soff = soff;
10394 			rsm->orig_m_len = rsm->m->m_len;
10395 			rsm->orig_t_space = M_TRAILINGROOM(rsm->m);
10396 		}
10397 	}
10398 	if (rack->app_limited_needs_set &&
10399 	    SEQ_GEQ(th_ack, tp->gput_seq))
10400 		rack_need_set_test(tp, rack, rsm, tp->snd_una, __LINE__, RACK_USE_BEG);
10401 }
10402 
10403 static void
10404 rack_handle_might_revert(struct tcpcb *tp, struct tcp_rack *rack)
10405 {
10406 	struct rack_sendmap *rsm;
10407 	int sack_pass_fnd = 0;
10408 
10409 	if (rack->r_might_revert) {
10410 		/*
10411 		 * Ok we have reordering, have not sent anything, we
10412 		 * might want to revert the congestion state if nothing
10413 		 * further has SACK_PASSED on it. Lets check.
10414 		 *
10415 		 * We also get here when we have DSACKs come in for
10416 		 * all the data that we FR'd. Note that a rxt or tlp
10417 		 * timer clears this from happening.
10418 		 */
10419 
10420 		TAILQ_FOREACH(rsm, &rack->r_ctl.rc_tmap, r_tnext) {
10421 			if (rsm->r_flags & RACK_SACK_PASSED) {
10422 				sack_pass_fnd = 1;
10423 				break;
10424 			}
10425 		}
10426 		if (sack_pass_fnd == 0) {
10427 			/*
10428 			 * We went into recovery
10429 			 * incorrectly due to reordering!
10430 			 */
10431 			int orig_cwnd;
10432 
10433 			rack->r_ent_rec_ns = 0;
10434 			orig_cwnd = tp->snd_cwnd;
10435 			tp->snd_ssthresh = rack->r_ctl.rc_ssthresh_at_erec;
10436 			tp->snd_recover = tp->snd_una;
10437 			rack_log_to_prr(rack, 14, orig_cwnd, __LINE__);
10438 			if (IN_RECOVERY(tp->t_flags)) {
10439 				rack_exit_recovery(tp, rack, 3);
10440 				if ((rack->rto_from_rec == 1) && (rack_ssthresh_rest_rto_rec != 0) ){
10441 					/*
10442 					 * We were in recovery, had an RTO
10443 					 * and then re-entered recovery (more sack's arrived)
10444 					 * and we have properly recorded the old ssthresh from
10445 					 * the first recovery. We want to be able to slow-start
10446 					 * back to this level. The ssthresh from the timeout
10447 					 * and then back into recovery will end up most likely
10448 					 * to be min(cwnd=1mss, 2mss). Which makes it basically
10449 					 * so we get no slow-start after our RTO.
10450 					 */
10451 					rack->rto_from_rec = 0;
10452 					if (rack->r_ctl.rto_ssthresh > tp->snd_ssthresh)
10453 						tp->snd_ssthresh = rack->r_ctl.rto_ssthresh;
10454 				}
10455 			}
10456 		}
10457 		rack->r_might_revert = 0;
10458 	}
10459 }
10460 
10461 
10462 static int
10463 rack_note_dsack(struct tcp_rack *rack, tcp_seq start, tcp_seq end)
10464 {
10465 
10466 	uint32_t am, l_end;
10467 	int was_tlp = 0;
10468 
10469 	if (SEQ_GT(end, start))
10470 		am = end - start;
10471 	else
10472 		am = 0;
10473 	if ((rack->rc_last_tlp_acked_set ) &&
10474 	    (SEQ_GEQ(start, rack->r_ctl.last_tlp_acked_start)) &&
10475 	    (SEQ_LEQ(end, rack->r_ctl.last_tlp_acked_end))) {
10476 		/*
10477 		 * The DSACK is because of a TLP which we don't
10478 		 * do anything with the reordering window over since
10479 		 * it was not reordering that caused the DSACK but
10480 		 * our previous retransmit TLP.
10481 		 */
10482 		rack_log_dsack_event(rack, 7, __LINE__, start, end);
10483 		was_tlp = 1;
10484 		goto skip_dsack_round;
10485 	}
10486 	if (rack->rc_last_sent_tlp_seq_valid) {
10487 		l_end = rack->r_ctl.last_sent_tlp_seq + rack->r_ctl.last_sent_tlp_len;
10488 		if (SEQ_GEQ(start, rack->r_ctl.last_sent_tlp_seq) &&
10489 		    (SEQ_LEQ(end, l_end))) {
10490 			/*
10491 			 * This dsack is from the last sent TLP, ignore it
10492 			 * for reordering purposes.
10493 			 */
10494 			rack_log_dsack_event(rack, 7, __LINE__, start, end);
10495 			was_tlp = 1;
10496 			goto skip_dsack_round;
10497 		}
10498 	}
10499 	if (rack->rc_dsack_round_seen == 0) {
10500 		rack->rc_dsack_round_seen = 1;
10501 		rack->r_ctl.dsack_round_end = rack->rc_tp->snd_max;
10502 		rack->r_ctl.num_dsack++;
10503 		rack->r_ctl.dsack_persist = 16;	/* 16 is from the standard */
10504 		rack_log_dsack_event(rack, 2, __LINE__, 0, 0);
10505 	}
10506 skip_dsack_round:
10507 	/*
10508 	 * We keep track of how many DSACK blocks we get
10509 	 * after a recovery incident.
10510 	 */
10511 	rack->r_ctl.dsack_byte_cnt += am;
10512 	if (!IN_FASTRECOVERY(rack->rc_tp->t_flags) &&
10513 	    rack->r_ctl.retran_during_recovery &&
10514 	    (rack->r_ctl.dsack_byte_cnt >= rack->r_ctl.retran_during_recovery)) {
10515 		/*
10516 		 * False recovery most likely culprit is reordering. If
10517 		 * nothing else is missing we need to revert.
10518 		 */
10519 		rack->r_might_revert = 1;
10520 		rack_handle_might_revert(rack->rc_tp, rack);
10521 		rack->r_might_revert = 0;
10522 		rack->r_ctl.retran_during_recovery = 0;
10523 		rack->r_ctl.dsack_byte_cnt = 0;
10524 	}
10525 	return (was_tlp);
10526 }
10527 
10528 static uint32_t
10529 do_rack_compute_pipe(struct tcpcb *tp, struct tcp_rack *rack, uint32_t snd_una)
10530 {
10531 	return (((tp->snd_max - snd_una) -
10532 		 (rack->r_ctl.rc_sacked + rack->r_ctl.rc_considered_lost)) + rack->r_ctl.rc_holes_rxt);
10533 }
10534 
10535 static int32_t
10536 rack_compute_pipe(struct tcpcb *tp)
10537 {
10538 	return ((int32_t)do_rack_compute_pipe(tp,
10539 					      (struct tcp_rack *)tp->t_fb_ptr,
10540 					      tp->snd_una));
10541 }
10542 
10543 static void
10544 rack_update_prr(struct tcpcb *tp, struct tcp_rack *rack, uint32_t changed, tcp_seq th_ack)
10545 {
10546 	/* Deal with changed and PRR here (in recovery only) */
10547 	uint32_t pipe, snd_una;
10548 
10549 	rack->r_ctl.rc_prr_delivered += changed;
10550 
10551 	if (sbavail(&rack->rc_inp->inp_socket->so_snd) <= (tp->snd_max - tp->snd_una)) {
10552 		/*
10553 		 * It is all outstanding, we are application limited
10554 		 * and thus we don't need more room to send anything.
10555 		 * Note we use tp->snd_una here and not th_ack because
10556 		 * the data as yet not been cut from the sb.
10557 		 */
10558 		rack->r_ctl.rc_prr_sndcnt = 0;
10559 		return;
10560 	}
10561 	/* Compute prr_sndcnt */
10562 	if (SEQ_GT(tp->snd_una, th_ack)) {
10563 		snd_una = tp->snd_una;
10564 	} else {
10565 		snd_una = th_ack;
10566 	}
10567 	pipe = do_rack_compute_pipe(tp, rack, snd_una);
10568 	if (pipe > tp->snd_ssthresh) {
10569 		long sndcnt;
10570 
10571 		sndcnt = rack->r_ctl.rc_prr_delivered * tp->snd_ssthresh;
10572 		if (rack->r_ctl.rc_prr_recovery_fs > 0)
10573 			sndcnt /= (long)rack->r_ctl.rc_prr_recovery_fs;
10574 		else {
10575 			rack->r_ctl.rc_prr_sndcnt = 0;
10576 			rack_log_to_prr(rack, 9, 0, __LINE__);
10577 			sndcnt = 0;
10578 		}
10579 		sndcnt++;
10580 		if (sndcnt > (long)rack->r_ctl.rc_prr_out)
10581 			sndcnt -= rack->r_ctl.rc_prr_out;
10582 		else
10583 			sndcnt = 0;
10584 		rack->r_ctl.rc_prr_sndcnt = sndcnt;
10585 		rack_log_to_prr(rack, 10, 0, __LINE__);
10586 	} else {
10587 		uint32_t limit;
10588 
10589 		if (rack->r_ctl.rc_prr_delivered > rack->r_ctl.rc_prr_out)
10590 			limit = (rack->r_ctl.rc_prr_delivered - rack->r_ctl.rc_prr_out);
10591 		else
10592 			limit = 0;
10593 		if (changed > limit)
10594 			limit = changed;
10595 		limit += ctf_fixed_maxseg(tp);
10596 		if (tp->snd_ssthresh > pipe) {
10597 			rack->r_ctl.rc_prr_sndcnt = min((tp->snd_ssthresh - pipe), limit);
10598 			rack_log_to_prr(rack, 11, 0, __LINE__);
10599 		} else {
10600 			rack->r_ctl.rc_prr_sndcnt = min(0, limit);
10601 			rack_log_to_prr(rack, 12, 0, __LINE__);
10602 		}
10603 	}
10604 }
10605 
10606 static void
10607 rack_log_ack(struct tcpcb *tp, struct tcpopt *to, struct tcphdr *th, int entered_recovery, int dup_ack_struck,
10608 	     int *dsack_seen, int *sacks_seen)
10609 {
10610 	uint32_t changed;
10611 	struct tcp_rack *rack;
10612 	struct rack_sendmap *rsm;
10613 	struct sackblk sack, sack_blocks[TCP_MAX_SACK + 1];
10614 	register uint32_t th_ack;
10615 	int32_t i, j, k, num_sack_blks = 0;
10616 	uint32_t cts, acked, ack_point;
10617 	int loop_start = 0;
10618 	uint32_t tsused;
10619 	uint32_t segsiz;
10620 
10621 
10622 	INP_WLOCK_ASSERT(tptoinpcb(tp));
10623 	if (tcp_get_flags(th) & TH_RST) {
10624 		/* We don't log resets */
10625 		return;
10626 	}
10627 	rack = (struct tcp_rack *)tp->t_fb_ptr;
10628 	cts = tcp_get_usecs(NULL);
10629 	rsm = tqhash_min(rack->r_ctl.tqh);
10630 	changed = 0;
10631 	th_ack = th->th_ack;
10632 	segsiz = ctf_fixed_maxseg(rack->rc_tp);
10633 	if (SEQ_GT(th_ack, tp->snd_una)) {
10634 		rack_log_progress_event(rack, tp, ticks, PROGRESS_UPDATE, __LINE__);
10635 		tp->t_acktime = ticks;
10636 	}
10637 	if (rsm && SEQ_GT(th_ack, rsm->r_start))
10638 		changed = th_ack - rsm->r_start;
10639 	if (changed) {
10640 		rack_process_to_cumack(tp, rack, th_ack, cts, to,
10641 				       tcp_tv_to_lusec(&rack->r_ctl.act_rcv_time));
10642 	}
10643 	if ((to->to_flags & TOF_SACK) == 0) {
10644 		/* We are done nothing left and no sack. */
10645 		rack_handle_might_revert(tp, rack);
10646 		/*
10647 		 * For cases where we struck a dup-ack
10648 		 * with no SACK, add to the changes so
10649 		 * PRR will work right.
10650 		 */
10651 		if (dup_ack_struck && (changed == 0)) {
10652 			changed += ctf_fixed_maxseg(rack->rc_tp);
10653 		}
10654 		goto out;
10655 	}
10656 	/* Sack block processing */
10657 	if (SEQ_GT(th_ack, tp->snd_una))
10658 		ack_point = th_ack;
10659 	else
10660 		ack_point = tp->snd_una;
10661 	for (i = 0; i < to->to_nsacks; i++) {
10662 		bcopy((to->to_sacks + i * TCPOLEN_SACK),
10663 		      &sack, sizeof(sack));
10664 		sack.start = ntohl(sack.start);
10665 		sack.end = ntohl(sack.end);
10666 		if (SEQ_GT(sack.end, sack.start) &&
10667 		    SEQ_GT(sack.start, ack_point) &&
10668 		    SEQ_LT(sack.start, tp->snd_max) &&
10669 		    SEQ_GT(sack.end, ack_point) &&
10670 		    SEQ_LEQ(sack.end, tp->snd_max)) {
10671 			sack_blocks[num_sack_blks] = sack;
10672 			num_sack_blks++;
10673 		} else if (SEQ_LEQ(sack.start, th_ack) &&
10674 			   SEQ_LEQ(sack.end, th_ack)) {
10675 			int was_tlp;
10676 
10677 			if (dsack_seen != NULL)
10678 				*dsack_seen = 1;
10679 			was_tlp = rack_note_dsack(rack, sack.start, sack.end);
10680 			/*
10681 			 * Its a D-SACK block.
10682 			 */
10683 			tcp_record_dsack(tp, sack.start, sack.end, was_tlp);
10684 		}
10685 	}
10686 	if (rack->rc_dsack_round_seen) {
10687 		/* Is the dsack roound over? */
10688 		if (SEQ_GEQ(th_ack, rack->r_ctl.dsack_round_end)) {
10689 			/* Yes it is */
10690 			rack->rc_dsack_round_seen = 0;
10691 			rack_log_dsack_event(rack, 3, __LINE__, 0, 0);
10692 		}
10693 	}
10694 	/*
10695 	 * Sort the SACK blocks so we can update the rack scoreboard with
10696 	 * just one pass.
10697 	 */
10698 	num_sack_blks = sack_filter_blks(tp, &rack->r_ctl.rack_sf, sack_blocks,
10699 					 num_sack_blks, th->th_ack);
10700 	ctf_log_sack_filter(rack->rc_tp, num_sack_blks, sack_blocks);
10701 	if (sacks_seen != NULL)
10702 		*sacks_seen = num_sack_blks;
10703 	if (num_sack_blks == 0) {
10704 		/* Nothing to sack */
10705 		goto out;
10706 	}
10707 	/* Its a sack of some sort */
10708 	if (num_sack_blks < 2) {
10709 		/* Only one, we don't need to sort */
10710 		goto do_sack_work;
10711 	}
10712 	/* Sort the sacks */
10713 	for (i = 0; i < num_sack_blks; i++) {
10714 		for (j = i + 1; j < num_sack_blks; j++) {
10715 			if (SEQ_GT(sack_blocks[i].end, sack_blocks[j].end)) {
10716 				sack = sack_blocks[i];
10717 				sack_blocks[i] = sack_blocks[j];
10718 				sack_blocks[j] = sack;
10719 			}
10720 		}
10721 	}
10722 	/*
10723 	 * Now are any of the sack block ends the same (yes some
10724 	 * implementations send these)?
10725 	 */
10726 again:
10727 	if (num_sack_blks == 0)
10728 		goto out;
10729 	if (num_sack_blks > 1) {
10730 		for (i = 0; i < num_sack_blks; i++) {
10731 			for (j = i + 1; j < num_sack_blks; j++) {
10732 				if (sack_blocks[i].end == sack_blocks[j].end) {
10733 					/*
10734 					 * Ok these two have the same end we
10735 					 * want the smallest end and then
10736 					 * throw away the larger and start
10737 					 * again.
10738 					 */
10739 					if (SEQ_LT(sack_blocks[j].start, sack_blocks[i].start)) {
10740 						/*
10741 						 * The second block covers
10742 						 * more area use that
10743 						 */
10744 						sack_blocks[i].start = sack_blocks[j].start;
10745 					}
10746 					/*
10747 					 * Now collapse out the dup-sack and
10748 					 * lower the count
10749 					 */
10750 					for (k = (j + 1); k < num_sack_blks; k++) {
10751 						sack_blocks[j].start = sack_blocks[k].start;
10752 						sack_blocks[j].end = sack_blocks[k].end;
10753 						j++;
10754 					}
10755 					num_sack_blks--;
10756 					goto again;
10757 				}
10758 			}
10759 		}
10760 	}
10761 do_sack_work:
10762 	/*
10763 	 * First lets look to see if
10764 	 * we have retransmitted and
10765 	 * can use the transmit next?
10766 	 */
10767 	rsm = TAILQ_FIRST(&rack->r_ctl.rc_tmap);
10768 	if (rsm &&
10769 	    SEQ_GT(sack_blocks[0].end, rsm->r_start) &&
10770 	    SEQ_LT(sack_blocks[0].start, rsm->r_end)) {
10771 		/*
10772 		 * We probably did the FR and the next
10773 		 * SACK in continues as we would expect.
10774 		 */
10775 		acked = rack_proc_sack_blk(tp, rack, &sack_blocks[0], to, &rsm, cts, segsiz);
10776 		if (acked) {
10777 			rack->r_wanted_output = 1;
10778 			changed += acked;
10779 		}
10780 		if (num_sack_blks == 1) {
10781 			goto out;
10782 		} else {
10783 			/*
10784 			 * Start the loop through the
10785 			 * rest of blocks, past the first block.
10786 			 */
10787 			loop_start = 1;
10788 		}
10789 	}
10790 	rsm = rack->r_ctl.rc_sacklast;
10791 	for (i = loop_start; i < num_sack_blks; i++) {
10792 		acked = rack_proc_sack_blk(tp, rack, &sack_blocks[i], to, &rsm, cts,  segsiz);
10793 		if (acked) {
10794 			rack->r_wanted_output = 1;
10795 			changed += acked;
10796 		}
10797 	}
10798 out:
10799 	if (changed) {
10800 		/* Something changed cancel the rack timer */
10801 		rack_timer_cancel(tp, rack, rack->r_ctl.rc_rcvtime, __LINE__);
10802 	}
10803 	tsused = tcp_get_usecs(NULL);
10804 	rsm = tcp_rack_output(tp, rack, tsused);
10805 	if ((!IN_FASTRECOVERY(tp->t_flags)) &&
10806 	    rsm &&
10807 	    ((rsm->r_flags & RACK_MUST_RXT) == 0)) {
10808 		/* Enter recovery */
10809 		entered_recovery = 1;
10810 		rack_cong_signal(tp, CC_NDUPACK, th_ack, __LINE__);
10811 		/*
10812 		 * When we enter recovery we need to assure we send
10813 		 * one packet.
10814 		 */
10815 		if (rack->rack_no_prr == 0) {
10816 			rack->r_ctl.rc_prr_sndcnt = ctf_fixed_maxseg(tp);
10817 			rack_log_to_prr(rack, 8, 0, __LINE__);
10818 		}
10819 		rack->r_timer_override = 1;
10820 		rack->r_early = 0;
10821 		rack->r_ctl.rc_agg_early = 0;
10822 	} else if (IN_FASTRECOVERY(tp->t_flags) &&
10823 		   rsm &&
10824 		   (rack->r_rr_config == 3)) {
10825 		/*
10826 		 * Assure we can output and we get no
10827 		 * remembered pace time except the retransmit.
10828 		 */
10829 		rack->r_timer_override = 1;
10830 		rack->r_ctl.rc_hpts_flags &= ~PACE_PKT_OUTPUT;
10831 		rack->r_ctl.rc_resend = rsm;
10832 	}
10833 	if (IN_FASTRECOVERY(tp->t_flags) &&
10834 	    (rack->rack_no_prr == 0) &&
10835 	    (entered_recovery == 0)) {
10836 		rack_update_prr(tp, rack, changed, th_ack);
10837 		if ((rsm && (rack->r_ctl.rc_prr_sndcnt >= ctf_fixed_maxseg(tp)) &&
10838 		     ((tcp_in_hpts(rack->rc_tp) == 0) &&
10839 		      ((rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT) == 0)))) {
10840 			/*
10841 			 * If you are pacing output you don't want
10842 			 * to override.
10843 			 */
10844 			rack->r_early = 0;
10845 			rack->r_ctl.rc_agg_early = 0;
10846 			rack->r_timer_override = 1;
10847 		}
10848 	}
10849 }
10850 
10851 static void
10852 rack_strike_dupack(struct tcp_rack *rack, tcp_seq th_ack)
10853 {
10854 	struct rack_sendmap *rsm;
10855 
10856 	rsm = TAILQ_FIRST(&rack->r_ctl.rc_tmap);
10857 	while (rsm) {
10858 		/*
10859 		 * We need to skip anything already set
10860 		 * to be retransmitted.
10861 		 */
10862 		if ((rsm->r_dupack >= DUP_ACK_THRESHOLD) ||
10863 		    (rsm->r_flags & RACK_MUST_RXT)) {
10864 			rsm = TAILQ_NEXT(rsm, r_tnext);
10865 			continue;
10866 		}
10867 		break;
10868 	}
10869 	if (rsm && (rsm->r_dupack < 0xff)) {
10870 		rsm->r_dupack++;
10871 		if (rsm->r_dupack >= DUP_ACK_THRESHOLD) {
10872 			struct timeval tv;
10873 			uint32_t cts;
10874 			/*
10875 			 * Here we see if we need to retransmit. For
10876 			 * a SACK type connection if enough time has passed
10877 			 * we will get a return of the rsm. For a non-sack
10878 			 * connection we will get the rsm returned if the
10879 			 * dupack value is 3 or more.
10880 			 */
10881 			cts = tcp_get_usecs(&tv);
10882 			rack->r_ctl.rc_resend = tcp_rack_output(rack->rc_tp, rack, cts);
10883 			if (rack->r_ctl.rc_resend != NULL) {
10884 				if (!IN_FASTRECOVERY(rack->rc_tp->t_flags)) {
10885 					rack_cong_signal(rack->rc_tp, CC_NDUPACK,
10886 							 th_ack,  __LINE__);
10887 				}
10888 				rack->r_wanted_output = 1;
10889 				rack->r_timer_override = 1;
10890 				rack_log_retran_reason(rack, rsm, __LINE__, 1, 3);
10891 			}
10892 		} else {
10893 			rack_log_retran_reason(rack, rsm, __LINE__, 0, 3);
10894 		}
10895 	}
10896 }
10897 
10898 static void
10899 rack_check_bottom_drag(struct tcpcb *tp,
10900 		       struct tcp_rack *rack,
10901 		       struct socket *so)
10902 {
10903 	/*
10904 	 * So what is dragging bottom?
10905 	 *
10906 	 * Dragging bottom means you were under pacing and had a
10907 	 * delay in processing inbound acks waiting on our pacing
10908 	 * timer to expire. While you were waiting all of the acknowledgments
10909 	 * for the packets you sent have arrived. This means we are pacing
10910 	 * way underneath the bottleneck to the point where our Goodput
10911 	 * measurements stop working, since they require more than one
10912 	 * ack (usually at least 8 packets worth with multiple acks so we can
10913 	 * gauge the inter-ack times). If that occurs we have a real problem
10914 	 * since we are stuck in a hole that we can't get out of without
10915 	 * something speeding us up.
10916 	 *
10917 	 * We also check to see if we are widdling down to just one segment
10918 	 * outstanding. If this occurs and we have room to send in our cwnd/rwnd
10919 	 * then we are adding the delayed ack interval into our measurments and
10920 	 * we need to speed up slightly.
10921 	 */
10922 	uint32_t segsiz, minseg;
10923 
10924 	segsiz = ctf_fixed_maxseg(tp);
10925 	minseg = segsiz;
10926 	if (tp->snd_max == tp->snd_una) {
10927 		/*
10928 		 * We are doing dynamic pacing and we are way
10929 		 * under. Basically everything got acked while
10930 		 * we were still waiting on the pacer to expire.
10931 		 *
10932 		 * This means we need to boost the b/w in
10933 		 * addition to any earlier boosting of
10934 		 * the multiplier.
10935 		 */
10936 		uint64_t lt_bw;
10937 
10938 		tcp_trace_point(rack->rc_tp, TCP_TP_PACED_BOTTOM);
10939 		lt_bw = rack_get_lt_bw(rack);
10940 		rack->rc_dragged_bottom = 1;
10941 		rack_validate_multipliers_at_or_above100(rack);
10942 		if ((rack->r_ctl.rack_rs.rs_flags & RACK_RTT_VALID) &&
10943 		    (rack->dis_lt_bw == 0) &&
10944 		    (rack->use_lesser_lt_bw == 0) &&
10945 		    (lt_bw > 0)) {
10946 			/*
10947 			 * Lets use the long-term b/w we have
10948 			 * been getting as a base.
10949 			 */
10950 			if (rack->rc_gp_filled == 0) {
10951 				if (lt_bw > ONE_POINT_TWO_MEG) {
10952 					/*
10953 					 * If we have no measurement
10954 					 * don't let us set in more than
10955 					 * 1.2Mbps. If we are still too
10956 					 * low after pacing with this we
10957 					 * will hopefully have a max b/w
10958 					 * available to sanity check things.
10959 					 */
10960 					lt_bw = ONE_POINT_TWO_MEG;
10961 				}
10962 				rack->r_ctl.rc_rtt_diff = 0;
10963 				rack->r_ctl.gp_bw = lt_bw;
10964 				rack->rc_gp_filled = 1;
10965 				if (rack->r_ctl.num_measurements < RACK_REQ_AVG)
10966 					rack->r_ctl.num_measurements = RACK_REQ_AVG;
10967 				rack_set_pace_segments(rack->rc_tp, rack, __LINE__, NULL);
10968 			} else if (lt_bw > rack->r_ctl.gp_bw) {
10969 				rack->r_ctl.rc_rtt_diff = 0;
10970 				if (rack->r_ctl.num_measurements < RACK_REQ_AVG)
10971 					rack->r_ctl.num_measurements = RACK_REQ_AVG;
10972 				rack->r_ctl.gp_bw = lt_bw;
10973 				rack_set_pace_segments(rack->rc_tp, rack, __LINE__, NULL);
10974 			} else
10975 				rack_increase_bw_mul(rack, -1, 0, 0, 1);
10976 			if ((rack->gp_ready == 0) &&
10977 			    (rack->r_ctl.num_measurements >= rack->r_ctl.req_measurements)) {
10978 				/* We have enough measurements now */
10979 				rack->gp_ready = 1;
10980 				if (rack->dgp_on ||
10981 				    rack->rack_hibeta)
10982 					rack_set_cc_pacing(rack);
10983 				if (rack->defer_options)
10984 					rack_apply_deferred_options(rack);
10985 			}
10986 		} else {
10987 			/*
10988 			 * zero rtt possibly?, settle for just an old increase.
10989 			 */
10990 			rack_increase_bw_mul(rack, -1, 0, 0, 1);
10991 		}
10992 	} else if ((IN_FASTRECOVERY(tp->t_flags) == 0) &&
10993 		   (sbavail(&so->so_snd) > max((segsiz * (4 + rack_req_segs)),
10994 					       minseg)) &&
10995 		   (rack->r_ctl.cwnd_to_use > max((segsiz * (rack_req_segs + 2)), minseg)) &&
10996 		   (tp->snd_wnd > max((segsiz * (rack_req_segs + 2)), minseg)) &&
10997 		   (ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked) <=
10998 		    (segsiz * rack_req_segs))) {
10999 		/*
11000 		 * We are doing dynamic GP pacing and
11001 		 * we have everything except 1MSS or less
11002 		 * bytes left out. We are still pacing away.
11003 		 * And there is data that could be sent, This
11004 		 * means we are inserting delayed ack time in
11005 		 * our measurements because we are pacing too slow.
11006 		 */
11007 		rack_validate_multipliers_at_or_above100(rack);
11008 		rack->rc_dragged_bottom = 1;
11009 		rack_increase_bw_mul(rack, -1, 0, 0, 1);
11010 	}
11011 }
11012 
11013 #ifdef TCP_REQUEST_TRK
11014 static void
11015 rack_log_hybrid(struct tcp_rack *rack, uint32_t seq,
11016 		struct tcp_sendfile_track *cur, uint8_t mod, int line, int err)
11017 {
11018 	int do_log;
11019 
11020 	do_log = tcp_bblogging_on(rack->rc_tp);
11021 	if (do_log == 0) {
11022 		if ((do_log = tcp_bblogging_point_on(rack->rc_tp, TCP_BBPOINT_REQ_LEVEL_LOGGING) )== 0)
11023 			return;
11024 		/* We only allow the three below with point logging on */
11025 		if ((mod != HYBRID_LOG_RULES_APP) &&
11026 		    (mod != HYBRID_LOG_RULES_SET) &&
11027 		    (mod != HYBRID_LOG_REQ_COMP))
11028 			return;
11029 
11030 	}
11031 	if (do_log) {
11032 		union tcp_log_stackspecific log;
11033 		struct timeval tv;
11034 
11035 		/* Convert our ms to a microsecond */
11036 		memset(&log, 0, sizeof(log));
11037 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
11038 		log.u_bbr.flex1 = seq;
11039 		log.u_bbr.cwnd_gain = line;
11040 		if (cur != NULL) {
11041 			uint64_t off;
11042 
11043 			log.u_bbr.flex2 = cur->start_seq;
11044 			log.u_bbr.flex3 = cur->end_seq;
11045 			log.u_bbr.flex4 = (uint32_t)((cur->localtime >> 32) & 0x00000000ffffffff);
11046 			log.u_bbr.flex5 = (uint32_t)(cur->localtime & 0x00000000ffffffff);
11047 			log.u_bbr.flex6 = cur->flags;
11048 			log.u_bbr.pkts_out = cur->hybrid_flags;
11049 			log.u_bbr.rttProp = cur->timestamp;
11050 			log.u_bbr.cur_del_rate = cur->cspr;
11051 			log.u_bbr.bw_inuse = cur->start;
11052 			log.u_bbr.applimited = (uint32_t)(cur->end & 0x00000000ffffffff);
11053 			log.u_bbr.delivered = (uint32_t)((cur->end >> 32) & 0x00000000ffffffff) ;
11054 			log.u_bbr.epoch = (uint32_t)(cur->deadline & 0x00000000ffffffff);
11055 			log.u_bbr.lt_epoch = (uint32_t)((cur->deadline >> 32) & 0x00000000ffffffff) ;
11056 			log.u_bbr.inhpts = 1;
11057 #ifdef TCP_REQUEST_TRK
11058 			off = (uint64_t)(cur) - (uint64_t)(&rack->rc_tp->t_tcpreq_info[0]);
11059 			log.u_bbr.use_lt_bw = (uint8_t)(off / sizeof(struct tcp_sendfile_track));
11060 #endif
11061 		} else {
11062 			log.u_bbr.flex2 = err;
11063 		}
11064 		/*
11065 		 * Fill in flex7 to be CHD (catchup|hybrid|DGP)
11066 		 */
11067 		log.u_bbr.flex7 = rack->rc_catch_up;
11068 		log.u_bbr.flex7 <<= 1;
11069 		log.u_bbr.flex7 |= rack->rc_hybrid_mode;
11070 		log.u_bbr.flex7 <<= 1;
11071 		log.u_bbr.flex7 |= rack->dgp_on;
11072 		/*
11073 		 * Compose bbr_state to be a bit wise 0000ADHF
11074 		 * where A is the always_pace flag
11075 		 * where D is the dgp_on flag
11076 		 * where H is the hybrid_mode on flag
11077 		 * where F is the use_fixed_rate flag.
11078 		 */
11079 		log.u_bbr.bbr_state = rack->rc_always_pace;
11080 		log.u_bbr.bbr_state <<= 1;
11081 		log.u_bbr.bbr_state |= rack->dgp_on;
11082 		log.u_bbr.bbr_state <<= 1;
11083 		log.u_bbr.bbr_state |= rack->rc_hybrid_mode;
11084 		log.u_bbr.bbr_state <<= 1;
11085 		log.u_bbr.bbr_state |= rack->use_fixed_rate;
11086 		log.u_bbr.flex8 = mod;
11087 		log.u_bbr.delRate = rack->r_ctl.bw_rate_cap;
11088 		log.u_bbr.bbr_substate = rack->r_ctl.client_suggested_maxseg;
11089 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
11090 		log.u_bbr.pkt_epoch = rack->rc_tp->tcp_hybrid_start;
11091 		log.u_bbr.lost = rack->rc_tp->tcp_hybrid_error;
11092 		log.u_bbr.pacing_gain = (uint16_t)rack->rc_tp->tcp_hybrid_stop;
11093 		tcp_log_event(rack->rc_tp, NULL,
11094 		    &rack->rc_inp->inp_socket->so_rcv,
11095 		    &rack->rc_inp->inp_socket->so_snd,
11096 		    TCP_HYBRID_PACING_LOG, 0,
11097 	            0, &log, false, NULL, __func__, __LINE__, &tv);
11098 	}
11099 }
11100 #endif
11101 
11102 #ifdef TCP_REQUEST_TRK
11103 static void
11104 rack_set_dgp_hybrid_mode(struct tcp_rack *rack, tcp_seq seq, uint32_t len, uint64_t cts)
11105 {
11106 	struct tcp_sendfile_track *rc_cur, *orig_ent;
11107 	struct tcpcb *tp;
11108 	int err = 0;
11109 
11110 	orig_ent = rack->r_ctl.rc_last_sft;
11111 	rc_cur = tcp_req_find_req_for_seq(rack->rc_tp, seq);
11112 	if (rc_cur == NULL) {
11113 		/* If not in the beginning what about the end piece */
11114 		if (rack->rc_hybrid_mode)
11115 			rack_log_hybrid(rack, seq, NULL, HYBRID_LOG_NO_RANGE, __LINE__, err);
11116 		rc_cur = tcp_req_find_req_for_seq(rack->rc_tp, (seq + len - 1));
11117 	} else {
11118 		err = 12345;
11119 	}
11120 	/* If we find no parameters we are in straight DGP mode */
11121 	if(rc_cur == NULL) {
11122 		/* None found for this seq, just DGP for now */
11123 		if (rack->rc_hybrid_mode) {
11124 			rack->r_ctl.client_suggested_maxseg = 0;
11125 			rack->rc_catch_up = 0;
11126 			if (rack->cspr_is_fcc == 0)
11127 				rack->r_ctl.bw_rate_cap = 0;
11128 			else
11129 				rack->r_ctl.fillcw_cap = rack_fillcw_bw_cap;
11130 		}
11131 		if (rack->rc_hybrid_mode) {
11132 			rack_log_hybrid(rack, (seq + len - 1), NULL, HYBRID_LOG_NO_RANGE, __LINE__, err);
11133 		}
11134 		if (rack->r_ctl.rc_last_sft) {
11135 			rack->r_ctl.rc_last_sft = NULL;
11136 		}
11137 		return;
11138 	}
11139 	if ((rc_cur->hybrid_flags & TCP_HYBRID_PACING_WASSET) == 0) {
11140 		/* This entry was never setup for hybrid pacing on/off etc */
11141 		if (rack->rc_hybrid_mode) {
11142 			rack->r_ctl.client_suggested_maxseg = 0;
11143 			rack->rc_catch_up = 0;
11144 			rack->r_ctl.bw_rate_cap = 0;
11145 		}
11146 		if (rack->r_ctl.rc_last_sft) {
11147 			rack->r_ctl.rc_last_sft = NULL;
11148 		}
11149 		if ((rc_cur->flags & TCP_TRK_TRACK_FLG_FSND) == 0) {
11150 			rc_cur->flags |= TCP_TRK_TRACK_FLG_FSND;
11151 			rc_cur->first_send = cts;
11152 			rc_cur->sent_at_fs = rack->rc_tp->t_sndbytes;
11153 			rc_cur->rxt_at_fs = rack->rc_tp->t_snd_rxt_bytes;
11154 		}
11155 		return;
11156 	}
11157 	/*
11158 	 * Ok if we have a new entry *or* have never
11159 	 * set up an entry we need to proceed. If
11160 	 * we have already set it up this entry we
11161 	 * just continue along with what we already
11162 	 * setup.
11163 	 */
11164 	tp = rack->rc_tp;
11165 	if ((rack->r_ctl.rc_last_sft != NULL) &&
11166 	    (rack->r_ctl.rc_last_sft == rc_cur)) {
11167 		/* Its already in place */
11168 		if (rack->rc_hybrid_mode)
11169 			rack_log_hybrid(rack, seq, rc_cur, HYBRID_LOG_ISSAME, __LINE__, 0);
11170 		return;
11171 	}
11172 	if (rack->rc_hybrid_mode == 0) {
11173 		rack->r_ctl.rc_last_sft = rc_cur;
11174 		if (orig_ent) {
11175 			orig_ent->sent_at_ls = rack->rc_tp->t_sndbytes;
11176 			orig_ent->rxt_at_ls = rack->rc_tp->t_snd_rxt_bytes;
11177 			orig_ent->flags |= TCP_TRK_TRACK_FLG_LSND;
11178 		}
11179 		rack_log_hybrid(rack, seq, rc_cur, HYBRID_LOG_RULES_APP, __LINE__, 0);
11180 		return;
11181 	}
11182 	if ((rc_cur->hybrid_flags & TCP_HYBRID_PACING_CSPR) && rc_cur->cspr){
11183 		/* Compensate for all the header overhead's */
11184 		if (rack->cspr_is_fcc == 0)
11185 			rack->r_ctl.bw_rate_cap	= rack_compensate_for_linerate(rack, rc_cur->cspr);
11186 		else
11187 			rack->r_ctl.fillcw_cap =  rack_compensate_for_linerate(rack, rc_cur->cspr);
11188 	} else {
11189 		if (rack->rc_hybrid_mode) {
11190 			if (rack->cspr_is_fcc == 0)
11191 				rack->r_ctl.bw_rate_cap = 0;
11192 			else
11193 				rack->r_ctl.fillcw_cap = rack_fillcw_bw_cap;
11194 		}
11195 	}
11196 	if (rc_cur->hybrid_flags & TCP_HYBRID_PACING_H_MS)
11197 		rack->r_ctl.client_suggested_maxseg = rc_cur->hint_maxseg;
11198 	else
11199 		rack->r_ctl.client_suggested_maxseg = 0;
11200 	if (rc_cur->timestamp == rack->r_ctl.last_tm_mark) {
11201 		/*
11202 		 * It is the same timestamp as the previous one
11203 		 * add the hybrid flag that will indicate we use
11204 		 * sendtime not arrival time for catch-up mode.
11205 		 */
11206 		rc_cur->hybrid_flags |= TCP_HYBRID_PACING_SENDTIME;
11207 	}
11208 	if ((rc_cur->hybrid_flags & TCP_HYBRID_PACING_CU) &&
11209 	    (rc_cur->cspr > 0)) {
11210 		uint64_t len;
11211 
11212 		rack->rc_catch_up = 1;
11213 		/*
11214 		 * Calculate the deadline time, first set the
11215 		 * time to when the request arrived.
11216 		 */
11217 		if (rc_cur->hybrid_flags & TCP_HYBRID_PACING_SENDTIME) {
11218 			/*
11219 			 * For cases where its a duplicate tm (we received more
11220 			 * than one request for a tm) we want to use now, the point
11221 			 * where we are just sending the first bit of the request.
11222 			 */
11223 			rc_cur->deadline = cts;
11224 		} else {
11225 			/*
11226 			 * Here we have a different tm from the last request
11227 			 * so we want to use arrival time as our base.
11228 			 */
11229 			rc_cur->deadline = rc_cur->localtime;
11230 		}
11231 		/*
11232 		 * Next calculate the length and compensate for
11233 		 * TLS if need be.
11234 		 */
11235 		len = rc_cur->end - rc_cur->start;
11236 		if (tp->t_inpcb.inp_socket->so_snd.sb_tls_info) {
11237 			/*
11238 			 * This session is doing TLS. Take a swag guess
11239 			 * at the overhead.
11240 			 */
11241 			len += tcp_estimate_tls_overhead(tp->t_inpcb.inp_socket, len);
11242 		}
11243 		/*
11244 		 * Now considering the size, and the cspr, what is the time that
11245 		 * would be required at the cspr rate. Here we use the raw
11246 		 * cspr value since the client only looks at the raw data. We
11247 		 * do use len which includes TLS overhead, but not the TCP/IP etc.
11248 		 * That will get made up for in the CU pacing rate set.
11249 		 */
11250 		len *= HPTS_USEC_IN_SEC;
11251 		len /= rc_cur->cspr;
11252 		rc_cur->deadline += len;
11253 	} else {
11254 		rack->rc_catch_up = 0;
11255 		rc_cur->deadline = 0;
11256 	}
11257 	if (rack->r_ctl.client_suggested_maxseg != 0) {
11258 		/*
11259 		 * We need to reset the max pace segs if we have a
11260 		 * client_suggested_maxseg.
11261 		 */
11262 		rack_set_pace_segments(tp, rack, __LINE__, NULL);
11263 	}
11264 	if (orig_ent) {
11265 		orig_ent->sent_at_ls = rack->rc_tp->t_sndbytes;
11266 		orig_ent->rxt_at_ls = rack->rc_tp->t_snd_rxt_bytes;
11267 		orig_ent->flags |= TCP_TRK_TRACK_FLG_LSND;
11268 	}
11269 	rack_log_hybrid(rack, seq, rc_cur, HYBRID_LOG_RULES_APP, __LINE__, 0);
11270 	/* Remember it for next time and for CU mode */
11271 	rack->r_ctl.rc_last_sft = rc_cur;
11272 	rack->r_ctl.last_tm_mark = rc_cur->timestamp;
11273 }
11274 #endif
11275 
11276 static void
11277 rack_chk_req_and_hybrid_on_out(struct tcp_rack *rack, tcp_seq seq, uint32_t len, uint64_t cts)
11278 {
11279 #ifdef TCP_REQUEST_TRK
11280 	struct tcp_sendfile_track *ent;
11281 
11282 	ent = rack->r_ctl.rc_last_sft;
11283 	if ((ent == NULL) ||
11284 	    (ent->flags == TCP_TRK_TRACK_FLG_EMPTY) ||
11285 	    (SEQ_GEQ(seq, ent->end_seq))) {
11286 		/* Time to update the track. */
11287 		rack_set_dgp_hybrid_mode(rack, seq, len, cts);
11288 		ent = rack->r_ctl.rc_last_sft;
11289 	}
11290 	/* Out of all */
11291 	if (ent == NULL) {
11292 		return;
11293 	}
11294 	if (SEQ_LT(ent->end_seq, (seq + len))) {
11295 		/*
11296 		 * This is the case where our end_seq guess
11297 		 * was wrong. This is usually due to TLS having
11298 		 * more bytes then our guess. It could also be the
11299 		 * case that the client sent in two requests closely
11300 		 * and the SB is full of both so we are sending part
11301 		 * of each (end|beg). In such a case lets move this
11302 		 * guys end to match the end of this send. That
11303 		 * way it will complete when all of it is acked.
11304 		 */
11305 		ent->end_seq = (seq + len);
11306 		if (rack->rc_hybrid_mode)
11307 			rack_log_hybrid_bw(rack, seq, len, 0, 0, HYBRID_LOG_EXTEND, 0, ent, __LINE__);
11308 	}
11309 	/* Now validate we have set the send time of this one */
11310 	if ((ent->flags & TCP_TRK_TRACK_FLG_FSND) == 0) {
11311 		ent->flags |= TCP_TRK_TRACK_FLG_FSND;
11312 		ent->first_send = cts;
11313 		ent->sent_at_fs = rack->rc_tp->t_sndbytes;
11314 		ent->rxt_at_fs = rack->rc_tp->t_snd_rxt_bytes;
11315 	}
11316 #endif
11317 }
11318 
11319 static void
11320 rack_gain_for_fastoutput(struct tcp_rack *rack, struct tcpcb *tp, struct socket *so, uint32_t acked_amount)
11321 {
11322 	/*
11323 	 * The fast output path is enabled and we
11324 	 * have moved the cumack forward. Lets see if
11325 	 * we can expand forward the fast path length by
11326 	 * that amount. What we would ideally like to
11327 	 * do is increase the number of bytes in the
11328 	 * fast path block (left_to_send) by the
11329 	 * acked amount. However we have to gate that
11330 	 * by two factors:
11331 	 * 1) The amount outstanding and the rwnd of the peer
11332 	 *    (i.e. we don't want to exceed the rwnd of the peer).
11333 	 *    <and>
11334 	 * 2) The amount of data left in the socket buffer (i.e.
11335 	 *    we can't send beyond what is in the buffer).
11336 	 *
11337 	 * Note that this does not take into account any increase
11338 	 * in the cwnd. We will only extend the fast path by
11339 	 * what was acked.
11340 	 */
11341 	uint32_t new_total, gating_val;
11342 
11343 	new_total = acked_amount + rack->r_ctl.fsb.left_to_send;
11344 	gating_val = min((sbavail(&so->so_snd) - (tp->snd_max - tp->snd_una)),
11345 			 (tp->snd_wnd - (tp->snd_max - tp->snd_una)));
11346 	if (new_total <= gating_val) {
11347 		/* We can increase left_to_send by the acked amount */
11348 		counter_u64_add(rack_extended_rfo, 1);
11349 		rack->r_ctl.fsb.left_to_send = new_total;
11350 		KASSERT((rack->r_ctl.fsb.left_to_send <= (sbavail(&rack->rc_inp->inp_socket->so_snd) - (tp->snd_max - tp->snd_una))),
11351 			("rack:%p left_to_send:%u sbavail:%u out:%u",
11352 			 rack, rack->r_ctl.fsb.left_to_send,
11353 			 sbavail(&rack->rc_inp->inp_socket->so_snd),
11354 			 (tp->snd_max - tp->snd_una)));
11355 
11356 	}
11357 }
11358 
11359 static void
11360 rack_adjust_sendmap_head(struct tcp_rack *rack, struct sockbuf *sb)
11361 {
11362 	/*
11363 	 * Here any sendmap entry that points to the
11364 	 * beginning mbuf must be adjusted to the correct
11365 	 * offset. This must be called with:
11366 	 * 1) The socket buffer locked
11367 	 * 2) snd_una adjusted to its new position.
11368 	 *
11369 	 * Note that (2) implies rack_ack_received has also
11370 	 * been called and all the sbcut's have been done.
11371 	 *
11372 	 * We grab the first mbuf in the socket buffer and
11373 	 * then go through the front of the sendmap, recalculating
11374 	 * the stored offset for any sendmap entry that has
11375 	 * that mbuf. We must use the sb functions to do this
11376 	 * since its possible an add was done has well as
11377 	 * the subtraction we may have just completed. This should
11378 	 * not be a penalty though, since we just referenced the sb
11379 	 * to go in and trim off the mbufs that we freed (of course
11380 	 * there will be a penalty for the sendmap references though).
11381 	 *
11382 	 * Note also with INVARIANT on, we validate with a KASSERT
11383 	 * that the first sendmap entry has a soff of 0.
11384 	 *
11385 	 */
11386 	struct mbuf *m;
11387 	struct rack_sendmap *rsm;
11388 	tcp_seq snd_una;
11389 #ifdef INVARIANTS
11390 	int first_processed = 0;
11391 #endif
11392 
11393 	snd_una = rack->rc_tp->snd_una;
11394 	SOCKBUF_LOCK_ASSERT(sb);
11395 	m = sb->sb_mb;
11396 	rsm = tqhash_min(rack->r_ctl.tqh);
11397 	if ((rsm == NULL) || (m == NULL)) {
11398 		/* Nothing outstanding */
11399 		return;
11400 	}
11401 	/* The very first RSM's mbuf must point to the head mbuf in the sb */
11402 	KASSERT((rsm->m == m),
11403 		("Rack:%p sb:%p rsm:%p -- first rsm mbuf not aligned to sb",
11404 		 rack, sb, rsm));
11405 	while (rsm->m && (rsm->m == m)) {
11406 		/* one to adjust */
11407 #ifdef INVARIANTS
11408 		struct mbuf *tm;
11409 		uint32_t soff;
11410 
11411 		tm = sbsndmbuf(sb, (rsm->r_start - snd_una), &soff);
11412 		if ((rsm->orig_m_len != m->m_len) ||
11413 		    (rsm->orig_t_space != M_TRAILINGROOM(m))){
11414 			rack_adjust_orig_mlen(rsm);
11415 		}
11416 		if (first_processed == 0) {
11417 			KASSERT((rsm->soff == 0),
11418 				("Rack:%p rsm:%p -- rsm at head but soff not zero",
11419 				 rack, rsm));
11420 			first_processed = 1;
11421 		}
11422 		if ((rsm->soff != soff) || (rsm->m != tm)) {
11423 			/*
11424 			 * This is not a fatal error, we anticipate it
11425 			 * might happen (the else code), so we count it here
11426 			 * so that under invariant we can see that it really
11427 			 * does happen.
11428 			 */
11429 			counter_u64_add(rack_adjust_map_bw, 1);
11430 		}
11431 		rsm->m = tm;
11432 		rsm->soff = soff;
11433 		if (tm) {
11434 			rsm->orig_m_len = rsm->m->m_len;
11435 			rsm->orig_t_space = M_TRAILINGROOM(rsm->m);
11436 		} else {
11437 			rsm->orig_m_len = 0;
11438 			rsm->orig_t_space = 0;
11439 		}
11440 #else
11441 		rsm->m = sbsndmbuf(sb, (rsm->r_start - snd_una), &rsm->soff);
11442 		if (rsm->m) {
11443 			rsm->orig_m_len = rsm->m->m_len;
11444 			rsm->orig_t_space = M_TRAILINGROOM(rsm->m);
11445 		} else {
11446 			rsm->orig_m_len = 0;
11447 			rsm->orig_t_space = 0;
11448 		}
11449 #endif
11450 		rsm = tqhash_next(rack->r_ctl.tqh, rsm);
11451 		if (rsm == NULL)
11452 			break;
11453 	}
11454 }
11455 
11456 #ifdef TCP_REQUEST_TRK
11457 static inline void
11458 rack_req_check_for_comp(struct tcp_rack *rack, tcp_seq th_ack)
11459 {
11460 	struct tcp_sendfile_track *ent;
11461 	int i;
11462 
11463 	if ((rack->rc_hybrid_mode == 0) &&
11464 	    (tcp_bblogging_point_on(rack->rc_tp, TCP_BBPOINT_REQ_LEVEL_LOGGING) == 0)) {
11465 		/*
11466 		 * Just do normal completions hybrid pacing is not on
11467 		 * and CLDL is off as well.
11468 		 */
11469 		tcp_req_check_for_comp(rack->rc_tp, th_ack);
11470 		return;
11471 	}
11472 	/*
11473 	 * Originally I was just going to find the th_ack associated
11474 	 * with an entry. But then I realized a large strech ack could
11475 	 * in theory ack two or more requests at once. So instead we
11476 	 * need to find all entries that are completed by th_ack not
11477 	 * just a single entry and do our logging.
11478 	 */
11479 	ent = tcp_req_find_a_req_that_is_completed_by(rack->rc_tp, th_ack, &i);
11480 	while (ent != NULL) {
11481 		/*
11482 		 * We may be doing hybrid pacing or CLDL and need more details possibly
11483 		 * so we do it manually instead of calling
11484 		 * tcp_req_check_for_comp()
11485 		 */
11486 		uint64_t laa, tim, data, cbw, ftim;
11487 
11488 		/* Ok this ack frees it */
11489 		rack_log_hybrid(rack, th_ack,
11490 				ent, HYBRID_LOG_REQ_COMP, __LINE__, 0);
11491 		rack_log_hybrid_sends(rack, ent, __LINE__);
11492 		/* calculate the time based on the ack arrival */
11493 		data = ent->end - ent->start;
11494 		laa = tcp_tv_to_lusec(&rack->r_ctl.act_rcv_time);
11495 		if (ent->flags & TCP_TRK_TRACK_FLG_FSND) {
11496 			if (ent->first_send > ent->localtime)
11497 				ftim = ent->first_send;
11498 			else
11499 				ftim = ent->localtime;
11500 		} else {
11501 			/* TSNH */
11502 			ftim = ent->localtime;
11503 		}
11504 		if (laa > ent->localtime)
11505 			tim = laa - ftim;
11506 		else
11507 			tim = 0;
11508 		cbw = data * HPTS_USEC_IN_SEC;
11509 		if (tim > 0)
11510 			cbw /= tim;
11511 		else
11512 			cbw = 0;
11513 		rack_log_hybrid_bw(rack, th_ack, cbw, tim, data, HYBRID_LOG_BW_MEASURE, 0, ent, __LINE__);
11514 		/*
11515 		 * Check to see if we are freeing what we are pointing to send wise
11516 		 * if so be sure to NULL the pointer so we know we are no longer
11517 		 * set to anything.
11518 		 */
11519 		if (ent == rack->r_ctl.rc_last_sft) {
11520 			rack->r_ctl.rc_last_sft = NULL;
11521 			if (rack->rc_hybrid_mode) {
11522 				rack->rc_catch_up = 0;
11523 				if (rack->cspr_is_fcc == 0)
11524 					rack->r_ctl.bw_rate_cap = 0;
11525 				else
11526 					rack->r_ctl.fillcw_cap = rack_fillcw_bw_cap;
11527 				rack->r_ctl.client_suggested_maxseg = 0;
11528 			}
11529 		}
11530 		/* Generate the log that the tcp_netflix call would have */
11531 		tcp_req_log_req_info(rack->rc_tp, ent,
11532 				      i, TCP_TRK_REQ_LOG_FREED, 0, 0);
11533 		/* Free it and see if there is another one */
11534 		tcp_req_free_a_slot(rack->rc_tp, ent);
11535 		ent = tcp_req_find_a_req_that_is_completed_by(rack->rc_tp, th_ack, &i);
11536 	}
11537 }
11538 #endif
11539 
11540 
11541 /*
11542  * Return value of 1, we do not need to call rack_process_data().
11543  * return value of 0, rack_process_data can be called.
11544  * For ret_val if its 0 the TCP is locked, if its non-zero
11545  * its unlocked and probably unsafe to touch the TCB.
11546  */
11547 static int
11548 rack_process_ack(struct mbuf *m, struct tcphdr *th, struct socket *so,
11549     struct tcpcb *tp, struct tcpopt *to,
11550     uint32_t tiwin, int32_t tlen,
11551     int32_t * ofia, int32_t thflags, int32_t *ret_val, int32_t orig_tlen)
11552 {
11553 	int32_t ourfinisacked = 0;
11554 	int32_t nsegs, acked_amount;
11555 	int32_t acked;
11556 	struct mbuf *mfree;
11557 	struct tcp_rack *rack;
11558 	int32_t under_pacing = 0;
11559 	int32_t post_recovery = 0;
11560 	uint32_t p_cwnd;
11561 
11562 	INP_WLOCK_ASSERT(tptoinpcb(tp));
11563 
11564 	rack = (struct tcp_rack *)tp->t_fb_ptr;
11565 	if (SEQ_GEQ(tp->snd_una, tp->iss + (65535 << tp->snd_scale))) {
11566 		/* Checking SEG.ACK against ISS is definitely redundant. */
11567 		tp->t_flags2 |= TF2_NO_ISS_CHECK;
11568 	}
11569 	if (!V_tcp_insecure_ack) {
11570 		tcp_seq seq_min;
11571 		bool ghost_ack_check;
11572 
11573 		if (tp->t_flags2 & TF2_NO_ISS_CHECK) {
11574 			/* Check for too old ACKs (RFC 5961, Section 5.2). */
11575 			seq_min = tp->snd_una - tp->max_sndwnd;
11576 			ghost_ack_check = false;
11577 		} else {
11578 			if (SEQ_GT(tp->iss + 1, tp->snd_una - tp->max_sndwnd)) {
11579 				/* Checking for ghost ACKs is stricter. */
11580 				seq_min = tp->iss + 1;
11581 				ghost_ack_check = true;
11582 			} else {
11583 				/*
11584 				 * Checking for too old ACKs (RFC 5961,
11585 				 * Section 5.2) is stricter.
11586 				 */
11587 				seq_min = tp->snd_una - tp->max_sndwnd;
11588 				ghost_ack_check = false;
11589 			}
11590 		}
11591 		if (SEQ_LT(th->th_ack, seq_min)) {
11592 			if (ghost_ack_check)
11593 				TCPSTAT_INC(tcps_rcvghostack);
11594 			else
11595 				TCPSTAT_INC(tcps_rcvacktooold);
11596 			/* Send challenge ACK. */
11597 			ctf_do_dropafterack(m, tp, th, thflags, tlen, ret_val);
11598 			rack->r_wanted_output = 1;
11599 			return (1);
11600 		}
11601 	}
11602 	if (SEQ_GT(th->th_ack, tp->snd_max)) {
11603 		ctf_do_dropafterack(m, tp, th, thflags, tlen, ret_val);
11604 		rack->r_wanted_output = 1;
11605 		return (1);
11606 	}
11607 	if (rack->gp_ready &&
11608 	    (rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT)) {
11609 		under_pacing = 1;
11610 	}
11611 	if (SEQ_GEQ(th->th_ack, tp->snd_una) || to->to_nsacks) {
11612 		int in_rec, dup_ack_struck = 0;
11613 		int dsack_seen = 0, sacks_seen = 0;
11614 
11615 		in_rec = IN_FASTRECOVERY(tp->t_flags);
11616 		if (rack->rc_in_persist) {
11617 			tp->t_rxtshift = 0;
11618 			RACK_TCPT_RANGESET(tp->t_rxtcur, RACK_REXMTVAL(tp),
11619 				      rack_rto_min, rack_rto_max, rack->r_ctl.timer_slop);
11620 		}
11621 
11622 		if ((th->th_ack == tp->snd_una) &&
11623 		    (tiwin == tp->snd_wnd) &&
11624 		    (orig_tlen == 0) &&
11625 		    ((to->to_flags & TOF_SACK) == 0)) {
11626 			rack_strike_dupack(rack, th->th_ack);
11627 			dup_ack_struck = 1;
11628 		}
11629 		rack_log_ack(tp, to, th, ((in_rec == 0) && IN_FASTRECOVERY(tp->t_flags)),
11630 			     dup_ack_struck, &dsack_seen, &sacks_seen);
11631 
11632 	}
11633 	if (__predict_false(SEQ_LEQ(th->th_ack, tp->snd_una))) {
11634 		/*
11635 		 * Old ack, behind (or duplicate to) the last one rcv'd
11636 		 * Note: We mark reordering is occuring if its
11637 		 * less than and we have not closed our window.
11638 		 */
11639 		if (SEQ_LT(th->th_ack, tp->snd_una) && (sbspace(&so->so_rcv) > ctf_fixed_maxseg(tp))) {
11640 			rack->r_ctl.rc_reorder_ts = tcp_tv_to_usec(&rack->r_ctl.act_rcv_time);
11641 			if (rack->r_ctl.rc_reorder_ts == 0)
11642 				rack->r_ctl.rc_reorder_ts = 1;
11643 		}
11644 		return (0);
11645 	}
11646 	/*
11647 	 * If we reach this point, ACK is not a duplicate, i.e., it ACKs
11648 	 * something we sent.
11649 	 */
11650 	if (tp->t_flags & TF_NEEDSYN) {
11651 		/*
11652 		 * T/TCP: Connection was half-synchronized, and our SYN has
11653 		 * been ACK'd (so connection is now fully synchronized).  Go
11654 		 * to non-starred state, increment snd_una for ACK of SYN,
11655 		 * and check if we can do window scaling.
11656 		 */
11657 		tp->t_flags &= ~TF_NEEDSYN;
11658 		tp->snd_una++;
11659 		/* Do window scaling? */
11660 		if ((tp->t_flags & (TF_RCVD_SCALE | TF_REQ_SCALE)) ==
11661 		    (TF_RCVD_SCALE | TF_REQ_SCALE)) {
11662 			tp->rcv_scale = tp->request_r_scale;
11663 			/* Send window already scaled. */
11664 		}
11665 	}
11666 	nsegs = max(1, m->m_pkthdr.lro_nsegs);
11667 
11668 	acked = BYTES_THIS_ACK(tp, th);
11669 	if (acked) {
11670 		/*
11671 		 * Any time we move the cum-ack forward clear
11672 		 * keep-alive tied probe-not-answered. The
11673 		 * persists clears its own on entry.
11674 		 */
11675 		rack->probe_not_answered = 0;
11676 	}
11677 	KMOD_TCPSTAT_ADD(tcps_rcvackpack, nsegs);
11678 	KMOD_TCPSTAT_ADD(tcps_rcvackbyte, acked);
11679 	/*
11680 	 * If we just performed our first retransmit, and the ACK arrives
11681 	 * within our recovery window, then it was a mistake to do the
11682 	 * retransmit in the first place.  Recover our original cwnd and
11683 	 * ssthresh, and proceed to transmit where we left off.
11684 	 */
11685 	if ((tp->t_flags & TF_PREVVALID) &&
11686 	    ((tp->t_flags & TF_RCVD_TSTMP) == 0)) {
11687 		tp->t_flags &= ~TF_PREVVALID;
11688 		if (tp->t_rxtshift == 1 &&
11689 		    (int)(ticks - tp->t_badrxtwin) < 0)
11690 			rack_cong_signal(tp, CC_RTO_ERR, th->th_ack, __LINE__);
11691 	}
11692 	if (acked) {
11693 		/* assure we are not backed off */
11694 		tp->t_rxtshift = 0;
11695 		RACK_TCPT_RANGESET(tp->t_rxtcur, RACK_REXMTVAL(tp),
11696 			      rack_rto_min, rack_rto_max, rack->r_ctl.timer_slop);
11697 		rack->rc_tlp_in_progress = 0;
11698 		rack->r_ctl.rc_tlp_cnt_out = 0;
11699 		/*
11700 		 * If it is the RXT timer we want to
11701 		 * stop it, so we can restart a TLP.
11702 		 */
11703 		if (rack->r_ctl.rc_hpts_flags & PACE_TMR_RXT)
11704 			rack_timer_cancel(tp, rack, rack->r_ctl.rc_rcvtime, __LINE__);
11705 #ifdef TCP_REQUEST_TRK
11706 		rack_req_check_for_comp(rack, th->th_ack);
11707 #endif
11708 	}
11709 	/*
11710 	 * If we have a timestamp reply, update smoothed round trip time. If
11711 	 * no timestamp is present but transmit timer is running and timed
11712 	 * sequence number was acked, update smoothed round trip time. Since
11713 	 * we now have an rtt measurement, cancel the timer backoff (cf.,
11714 	 * Phil Karn's retransmit alg.). Recompute the initial retransmit
11715 	 * timer.
11716 	 *
11717 	 * Some boxes send broken timestamp replies during the SYN+ACK
11718 	 * phase, ignore timestamps of 0 or we could calculate a huge RTT
11719 	 * and blow up the retransmit timer.
11720 	 */
11721 	/*
11722 	 * If all outstanding data is acked, stop retransmit timer and
11723 	 * remember to restart (more output or persist). If there is more
11724 	 * data to be acked, restart retransmit timer, using current
11725 	 * (possibly backed-off) value.
11726 	 */
11727 	if (acked == 0) {
11728 		if (ofia)
11729 			*ofia = ourfinisacked;
11730 		return (0);
11731 	}
11732 	if (IN_RECOVERY(tp->t_flags)) {
11733 		if (SEQ_LT(th->th_ack, tp->snd_recover) &&
11734 		    (SEQ_LT(th->th_ack, tp->snd_max))) {
11735 			tcp_rack_partialack(tp);
11736 		} else {
11737 			rack_post_recovery(tp, th->th_ack);
11738 			post_recovery = 1;
11739 			/*
11740 			 * Grab the segsiz, multiply by 2 and add the snd_cwnd
11741 			 * that is the max the CC should add if we are exiting
11742 			 * recovery and doing a late add.
11743 			 */
11744 			p_cwnd = min(ctf_fixed_maxseg(tp), rack->r_ctl.rc_pace_min_segs);
11745 			p_cwnd <<= 1;
11746 			p_cwnd += tp->snd_cwnd;
11747 		}
11748 	} else if ((rack->rto_from_rec == 1) &&
11749 		   SEQ_GEQ(th->th_ack, tp->snd_recover)) {
11750 		/*
11751 		 * We were in recovery, hit a rxt timeout
11752 		 * and never re-entered recovery. The timeout(s)
11753 		 * made up all the lost data. In such a case
11754 		 * we need to clear the rto_from_rec flag.
11755 		 */
11756 		rack->rto_from_rec = 0;
11757 	}
11758 	/*
11759 	 * Let the congestion control algorithm update congestion control
11760 	 * related information. This typically means increasing the
11761 	 * congestion window.
11762 	 */
11763 	rack_ack_received(tp, rack, th->th_ack, nsegs, CC_ACK, post_recovery);
11764 	if (post_recovery &&
11765 	    (tp->snd_cwnd > p_cwnd)) {
11766 		/* Must be non-newreno (cubic) getting too ahead of itself */
11767 		tp->snd_cwnd = p_cwnd;
11768 	}
11769 	SOCK_SENDBUF_LOCK(so);
11770 	acked_amount = min(acked, (int)sbavail(&so->so_snd));
11771 	tp->snd_wnd -= acked_amount;
11772 	mfree = sbcut_locked(&so->so_snd, acked_amount);
11773 	if ((sbused(&so->so_snd) == 0) &&
11774 	    (acked > acked_amount) &&
11775 	    (tp->t_state >= TCPS_FIN_WAIT_1) &&
11776 	    (tp->t_flags & TF_SENTFIN)) {
11777 		/*
11778 		 * We must be sure our fin
11779 		 * was sent and acked (we can be
11780 		 * in FIN_WAIT_1 without having
11781 		 * sent the fin).
11782 		 */
11783 		ourfinisacked = 1;
11784 	}
11785 	tp->snd_una = th->th_ack;
11786 	/* wakeups? */
11787 	if (acked_amount && sbavail(&so->so_snd))
11788 		rack_adjust_sendmap_head(rack, &so->so_snd);
11789 	rack_log_wakeup(tp,rack, &so->so_snd, acked, 2);
11790 	/* NB: sowwakeup_locked() does an implicit unlock. */
11791 	sowwakeup_locked(so);
11792 	m_freem(mfree);
11793 	if (SEQ_GT(tp->snd_una, tp->snd_recover))
11794 		tp->snd_recover = tp->snd_una;
11795 
11796 	if (SEQ_LT(tp->snd_nxt, tp->snd_max)) {
11797 		tp->snd_nxt = tp->snd_max;
11798 	}
11799 	if (under_pacing &&
11800 	    (rack->use_fixed_rate == 0) &&
11801 	    (rack->in_probe_rtt == 0) &&
11802 	    rack->rc_gp_dyn_mul &&
11803 	    rack->rc_always_pace) {
11804 		/* Check if we are dragging bottom */
11805 		rack_check_bottom_drag(tp, rack, so);
11806 	}
11807 	if (tp->snd_una == tp->snd_max) {
11808 		/* Nothing left outstanding */
11809 		tp->t_flags &= ~TF_PREVVALID;
11810 		if (rack->r_ctl.rc_went_idle_time == 0)
11811 			rack->r_ctl.rc_went_idle_time = 1;
11812 		rack->r_ctl.retran_during_recovery = 0;
11813 		rack->r_ctl.dsack_byte_cnt = 0;
11814 		rack_log_progress_event(rack, tp, 0, PROGRESS_CLEAR, __LINE__);
11815 		if (sbavail(&tptosocket(tp)->so_snd) == 0)
11816 			tp->t_acktime = 0;
11817 		rack_timer_cancel(tp, rack, rack->r_ctl.rc_rcvtime, __LINE__);
11818 		rack->rc_suspicious = 0;
11819 		/* Set need output so persist might get set */
11820 		rack->r_wanted_output = 1;
11821 		sack_filter_clear(&rack->r_ctl.rack_sf, tp->snd_una);
11822 		if ((tp->t_state >= TCPS_FIN_WAIT_1) &&
11823 		    (sbavail(&so->so_snd) == 0) &&
11824 		    (tp->t_flags2 & TF2_DROP_AF_DATA)) {
11825 			/*
11826 			 * The socket was gone and the
11827 			 * peer sent data (now or in the past), time to
11828 			 * reset him.
11829 			 */
11830 			*ret_val = 1;
11831 			/* tcp_close will kill the inp pre-log the Reset */
11832 			tcp_log_end_status(tp, TCP_EI_STATUS_SERVER_RST);
11833 			tp = tcp_close(tp);
11834 			ctf_do_dropwithreset(m, tp, th, tlen);
11835 			return (1);
11836 		}
11837 	}
11838 	if (ofia)
11839 		*ofia = ourfinisacked;
11840 	return (0);
11841 }
11842 
11843 
11844 static void
11845 rack_log_collapse(struct tcp_rack *rack, uint32_t cnt, uint32_t split, uint32_t out, int line,
11846 		  int dir, uint32_t flags, struct rack_sendmap *rsm)
11847 {
11848 	if (tcp_bblogging_on(rack->rc_tp)) {
11849 		union tcp_log_stackspecific log;
11850 		struct timeval tv;
11851 
11852 		memset(&log, 0, sizeof(log));
11853 		log.u_bbr.flex1 = cnt;
11854 		log.u_bbr.flex2 = split;
11855 		log.u_bbr.flex3 = out;
11856 		log.u_bbr.flex4 = line;
11857 		log.u_bbr.flex5 = rack->r_must_retran;
11858 		log.u_bbr.flex6 = flags;
11859 		log.u_bbr.flex7 = rack->rc_has_collapsed;
11860 		log.u_bbr.flex8 = dir;	/*
11861 					 * 1 is collapsed, 0 is uncollapsed,
11862 					 * 2 is log of a rsm being marked, 3 is a split.
11863 					 */
11864 		if (rsm == NULL)
11865 			log.u_bbr.rttProp = 0;
11866 		else
11867 			log.u_bbr.rttProp = (uintptr_t)rsm;
11868 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
11869 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
11870 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
11871 		    &rack->rc_inp->inp_socket->so_rcv,
11872 		    &rack->rc_inp->inp_socket->so_snd,
11873 		    TCP_RACK_LOG_COLLAPSE, 0,
11874 		    0, &log, false, &tv);
11875 	}
11876 }
11877 
11878 static void
11879 rack_collapsed_window(struct tcp_rack *rack, uint32_t out, tcp_seq th_ack, int line)
11880 {
11881 	/*
11882 	 * Here all we do is mark the collapsed point and set the flag.
11883 	 * This may happen again and again, but there is no
11884 	 * sense splitting our map until we know where the
11885 	 * peer finally lands in the collapse.
11886 	 */
11887 	tcp_trace_point(rack->rc_tp, TCP_TP_COLLAPSED_WND);
11888 	if ((rack->rc_has_collapsed == 0) ||
11889 	    (rack->r_ctl.last_collapse_point != (th_ack + rack->rc_tp->snd_wnd)))
11890 		counter_u64_add(rack_collapsed_win_seen, 1);
11891 	rack->r_ctl.last_collapse_point = th_ack + rack->rc_tp->snd_wnd;
11892 	rack->r_ctl.high_collapse_point = rack->rc_tp->snd_max;
11893 	rack->rc_has_collapsed = 1;
11894 	rack->r_collapse_point_valid = 1;
11895 	rack_log_collapse(rack, 0, th_ack, rack->r_ctl.last_collapse_point, line, 1, 0, NULL);
11896 }
11897 
11898 static void
11899 rack_un_collapse_window(struct tcp_rack *rack, int line)
11900 {
11901 	struct rack_sendmap *nrsm, *rsm;
11902 	int cnt = 0, split = 0;
11903 	int insret __diagused;
11904 
11905 
11906 	tcp_trace_point(rack->rc_tp, TCP_TP_COLLAPSED_WND);
11907 	rack->rc_has_collapsed = 0;
11908 	rsm = tqhash_find(rack->r_ctl.tqh, rack->r_ctl.last_collapse_point);
11909 	if (rsm == NULL) {
11910 		/* Nothing to do maybe the peer ack'ed it all */
11911 		rack_log_collapse(rack, 0, 0, ctf_outstanding(rack->rc_tp), line, 0, 0, NULL);
11912 		return;
11913 	}
11914 	/* Now do we need to split this one? */
11915 	if (SEQ_GT(rack->r_ctl.last_collapse_point, rsm->r_start)) {
11916 		rack_log_collapse(rack, rsm->r_start, rsm->r_end,
11917 				  rack->r_ctl.last_collapse_point, line, 3, rsm->r_flags, rsm);
11918 		nrsm = rack_alloc_limit(rack, RACK_LIMIT_TYPE_SPLIT);
11919 		if (nrsm == NULL) {
11920 			/* We can't get a rsm, mark all? */
11921 			nrsm = rsm;
11922 			goto no_split;
11923 		}
11924 		/* Clone it */
11925 		split = 1;
11926 		rack_clone_rsm(rack, nrsm, rsm, rack->r_ctl.last_collapse_point);
11927 #ifndef INVARIANTS
11928 		(void)tqhash_insert(rack->r_ctl.tqh, nrsm);
11929 #else
11930 		if ((insret = tqhash_insert(rack->r_ctl.tqh, nrsm)) != 0) {
11931 			panic("Insert in tailq_hash of %p fails ret:%d rack:%p rsm:%p",
11932 			      nrsm, insret, rack, rsm);
11933 		}
11934 #endif
11935 		rack_log_map_chg(rack->rc_tp, rack, NULL, rsm, nrsm, MAP_SPLIT,
11936 				 rack->r_ctl.last_collapse_point, __LINE__);
11937 		if (rsm->r_in_tmap) {
11938 			TAILQ_INSERT_AFTER(&rack->r_ctl.rc_tmap, rsm, nrsm, r_tnext);
11939 			nrsm->r_in_tmap = 1;
11940 		}
11941 		/*
11942 		 * Set in the new RSM as the
11943 		 * collapsed starting point
11944 		 */
11945 		rsm = nrsm;
11946 	}
11947 
11948 no_split:
11949 	TQHASH_FOREACH_FROM(nrsm, rack->r_ctl.tqh, rsm)  {
11950 		cnt++;
11951 		nrsm->r_flags |= RACK_RWND_COLLAPSED;
11952 		rack_log_collapse(rack, nrsm->r_start, nrsm->r_end, 0, line, 4, nrsm->r_flags, nrsm);
11953 		cnt++;
11954 	}
11955 	if (cnt) {
11956 		counter_u64_add(rack_collapsed_win, 1);
11957 	}
11958 	rack_log_collapse(rack, cnt, split, ctf_outstanding(rack->rc_tp), line, 0, 0, NULL);
11959 }
11960 
11961 static void
11962 rack_handle_delayed_ack(struct tcpcb *tp, struct tcp_rack *rack,
11963 			int32_t tlen, int32_t tfo_syn)
11964 {
11965 	if (DELAY_ACK(tp, tlen) || tfo_syn) {
11966 		rack_timer_cancel(tp, rack,
11967 				  rack->r_ctl.rc_rcvtime, __LINE__);
11968 		tp->t_flags |= TF_DELACK;
11969 	} else {
11970 		rack->r_wanted_output = 1;
11971 		tp->t_flags |= TF_ACKNOW;
11972 	}
11973 }
11974 
11975 static void
11976 rack_validate_fo_sendwin_up(struct tcpcb *tp, struct tcp_rack *rack)
11977 {
11978 	/*
11979 	 * If fast output is in progress, lets validate that
11980 	 * the new window did not shrink on us and make it
11981 	 * so fast output should end.
11982 	 */
11983 	if (rack->r_fast_output) {
11984 		uint32_t out;
11985 
11986 		/*
11987 		 * Calculate what we will send if left as is
11988 		 * and compare that to our send window.
11989 		 */
11990 		out = ctf_outstanding(tp);
11991 		if ((out + rack->r_ctl.fsb.left_to_send) > tp->snd_wnd) {
11992 			/* ok we have an issue */
11993 			if (out >= tp->snd_wnd) {
11994 				/* Turn off fast output the window is met or collapsed */
11995 				rack->r_fast_output = 0;
11996 			} else {
11997 				/* we have some room left */
11998 				rack->r_ctl.fsb.left_to_send = tp->snd_wnd - out;
11999 				if (rack->r_ctl.fsb.left_to_send < ctf_fixed_maxseg(tp)) {
12000 					/* If not at least 1 full segment never mind */
12001 					rack->r_fast_output = 0;
12002 				}
12003 			}
12004 		}
12005 	}
12006 }
12007 
12008 /*
12009  * Return value of 1, the TCB is unlocked and most
12010  * likely gone, return value of 0, the TCP is still
12011  * locked.
12012  */
12013 static int
12014 rack_process_data(struct mbuf *m, struct tcphdr *th, struct socket *so,
12015     struct tcpcb *tp, int32_t drop_hdrlen, int32_t tlen,
12016     uint32_t tiwin, int32_t thflags, int32_t nxt_pkt)
12017 {
12018 	/*
12019 	 * Update window information. Don't look at window if no ACK: TAC's
12020 	 * send garbage on first SYN.
12021 	 */
12022 	int32_t nsegs;
12023 	int32_t tfo_syn;
12024 	struct tcp_rack *rack;
12025 
12026 	INP_WLOCK_ASSERT(tptoinpcb(tp));
12027 
12028 	rack = (struct tcp_rack *)tp->t_fb_ptr;
12029 	nsegs = max(1, m->m_pkthdr.lro_nsegs);
12030 	if ((thflags & TH_ACK) &&
12031 	    (SEQ_LT(tp->snd_wl1, th->th_seq) ||
12032 	    (tp->snd_wl1 == th->th_seq && (SEQ_LT(tp->snd_wl2, th->th_ack) ||
12033 	    (tp->snd_wl2 == th->th_ack && tiwin > tp->snd_wnd))))) {
12034 		/* keep track of pure window updates */
12035 		if (tlen == 0 &&
12036 		    tp->snd_wl2 == th->th_ack && tiwin > tp->snd_wnd)
12037 			KMOD_TCPSTAT_INC(tcps_rcvwinupd);
12038 		tp->snd_wnd = tiwin;
12039 		rack_validate_fo_sendwin_up(tp, rack);
12040 		tp->snd_wl1 = th->th_seq;
12041 		tp->snd_wl2 = th->th_ack;
12042 		if (tp->snd_wnd > tp->max_sndwnd)
12043 			tp->max_sndwnd = tp->snd_wnd;
12044 		rack->r_wanted_output = 1;
12045 	} else if (thflags & TH_ACK) {
12046 		if ((tp->snd_wl2 == th->th_ack) && (tiwin < tp->snd_wnd)) {
12047 			tp->snd_wnd = tiwin;
12048 			rack_validate_fo_sendwin_up(tp, rack);
12049 			tp->snd_wl1 = th->th_seq;
12050 			tp->snd_wl2 = th->th_ack;
12051 		}
12052 	}
12053 	if (tp->snd_wnd < ctf_outstanding(tp))
12054 		/* The peer collapsed the window */
12055 		rack_collapsed_window(rack, ctf_outstanding(tp), th->th_ack, __LINE__);
12056 	else if (rack->rc_has_collapsed)
12057 		rack_un_collapse_window(rack, __LINE__);
12058 	if ((rack->r_collapse_point_valid) &&
12059 	    (SEQ_GT(th->th_ack, rack->r_ctl.high_collapse_point)))
12060 		rack->r_collapse_point_valid = 0;
12061 	/* Was persist timer active and now we have window space? */
12062 	if ((rack->rc_in_persist != 0) &&
12063 	    (tp->snd_wnd >= min((rack->r_ctl.rc_high_rwnd/2),
12064 				rack->r_ctl.rc_pace_min_segs))) {
12065 		rack_exit_persist(tp, rack, rack->r_ctl.rc_rcvtime);
12066 		tp->snd_nxt = tp->snd_max;
12067 		/* Make sure we output to start the timer */
12068 		rack->r_wanted_output = 1;
12069 	}
12070 	/* Do we enter persists? */
12071 	if ((rack->rc_in_persist == 0) &&
12072 	    (tp->snd_wnd < min((rack->r_ctl.rc_high_rwnd/2), rack->r_ctl.rc_pace_min_segs)) &&
12073 	    TCPS_HAVEESTABLISHED(tp->t_state) &&
12074 	    ((tp->snd_max == tp->snd_una) || rack->rc_has_collapsed) &&
12075 	    sbavail(&tptosocket(tp)->so_snd) &&
12076 	    (sbavail(&tptosocket(tp)->so_snd) > tp->snd_wnd)) {
12077 		/*
12078 		 * Here the rwnd is less than
12079 		 * the pacing size, we are established,
12080 		 * nothing is outstanding, and there is
12081 		 * data to send. Enter persists.
12082 		 */
12083 		rack_enter_persist(tp, rack, rack->r_ctl.rc_rcvtime, tp->snd_una);
12084 	}
12085 	if (tp->t_flags2 & TF2_DROP_AF_DATA) {
12086 		m_freem(m);
12087 		return (0);
12088 	}
12089 	/*
12090 	 * don't process the URG bit, ignore them drag
12091 	 * along the up.
12092 	 */
12093 	tp->rcv_up = tp->rcv_nxt;
12094 
12095 	/*
12096 	 * Process the segment text, merging it into the TCP sequencing
12097 	 * queue, and arranging for acknowledgment of receipt if necessary.
12098 	 * This process logically involves adjusting tp->rcv_wnd as data is
12099 	 * presented to the user (this happens in tcp_usrreq.c, case
12100 	 * PRU_RCVD).  If a FIN has already been received on this connection
12101 	 * then we just ignore the text.
12102 	 */
12103 	tfo_syn = ((tp->t_state == TCPS_SYN_RECEIVED) &&
12104 	    (tp->t_flags & TF_FASTOPEN));
12105 	if ((tlen || (thflags & TH_FIN) || (tfo_syn && tlen > 0)) &&
12106 	    TCPS_HAVERCVDFIN(tp->t_state) == 0) {
12107 		tcp_seq save_start = th->th_seq;
12108 		tcp_seq save_rnxt  = tp->rcv_nxt;
12109 		int     save_tlen  = tlen;
12110 
12111 		m_adj(m, drop_hdrlen);	/* delayed header drop */
12112 		/*
12113 		 * Insert segment which includes th into TCP reassembly
12114 		 * queue with control block tp.  Set thflags to whether
12115 		 * reassembly now includes a segment with FIN.  This handles
12116 		 * the common case inline (segment is the next to be
12117 		 * received on an established connection, and the queue is
12118 		 * empty), avoiding linkage into and removal from the queue
12119 		 * and repetition of various conversions. Set DELACK for
12120 		 * segments received in order, but ack immediately when
12121 		 * segments are out of order (so fast retransmit can work).
12122 		 */
12123 		if (th->th_seq == tp->rcv_nxt &&
12124 		    SEGQ_EMPTY(tp) &&
12125 		    (TCPS_HAVEESTABLISHED(tp->t_state) ||
12126 		    tfo_syn)) {
12127 #ifdef NETFLIX_SB_LIMITS
12128 			u_int mcnt, appended;
12129 
12130 			if (so->so_rcv.sb_shlim) {
12131 				mcnt = m_memcnt(m);
12132 				appended = 0;
12133 				if (counter_fo_get(so->so_rcv.sb_shlim, mcnt,
12134 				    CFO_NOSLEEP, NULL) == false) {
12135 					counter_u64_add(tcp_sb_shlim_fails, 1);
12136 					m_freem(m);
12137 					return (0);
12138 				}
12139 			}
12140 #endif
12141 			rack_handle_delayed_ack(tp, rack, tlen, tfo_syn);
12142 			tp->rcv_nxt += tlen;
12143 			if (tlen &&
12144 			    ((tp->t_flags2 & TF2_FBYTES_COMPLETE) == 0) &&
12145 			    (tp->t_fbyte_in == 0)) {
12146 				tp->t_fbyte_in = ticks;
12147 				if (tp->t_fbyte_in == 0)
12148 					tp->t_fbyte_in = 1;
12149 				if (tp->t_fbyte_out && tp->t_fbyte_in)
12150 					tp->t_flags2 |= TF2_FBYTES_COMPLETE;
12151 			}
12152 			thflags = tcp_get_flags(th) & TH_FIN;
12153 			KMOD_TCPSTAT_ADD(tcps_rcvpack, nsegs);
12154 			KMOD_TCPSTAT_ADD(tcps_rcvbyte, tlen);
12155 			SOCK_RECVBUF_LOCK(so);
12156 			if (so->so_rcv.sb_state & SBS_CANTRCVMORE) {
12157 				m_freem(m);
12158 			} else {
12159 				int32_t newsize;
12160 
12161 				if (tlen > 0) {
12162 					newsize = tcp_autorcvbuf(m, th, so, tp, tlen);
12163 					if (newsize)
12164 						if (!sbreserve_locked(so, SO_RCV, newsize, NULL))
12165 							so->so_rcv.sb_flags &= ~SB_AUTOSIZE;
12166 				}
12167 #ifdef NETFLIX_SB_LIMITS
12168 				appended =
12169 #endif
12170 					sbappendstream_locked(&so->so_rcv, m, 0);
12171 			}
12172 			rack_log_wakeup(tp,rack, &so->so_rcv, tlen, 1);
12173 			/* NB: sorwakeup_locked() does an implicit unlock. */
12174 			sorwakeup_locked(so);
12175 #ifdef NETFLIX_SB_LIMITS
12176 			if (so->so_rcv.sb_shlim && appended != mcnt)
12177 				counter_fo_release(so->so_rcv.sb_shlim,
12178 				    mcnt - appended);
12179 #endif
12180 		} else {
12181 			/*
12182 			 * XXX: Due to the header drop above "th" is
12183 			 * theoretically invalid by now.  Fortunately
12184 			 * m_adj() doesn't actually frees any mbufs when
12185 			 * trimming from the head.
12186 			 */
12187 			tcp_seq temp = save_start;
12188 
12189 			thflags = tcp_reass(tp, th, &temp, &tlen, m);
12190 			tp->t_flags |= TF_ACKNOW;
12191 			if (tp->t_flags & TF_WAKESOR) {
12192 				tp->t_flags &= ~TF_WAKESOR;
12193 				/* NB: sorwakeup_locked() does an implicit unlock. */
12194 				sorwakeup_locked(so);
12195 			}
12196 		}
12197 		if ((tp->t_flags & TF_SACK_PERMIT) &&
12198 		    (save_tlen > 0) &&
12199 		    TCPS_HAVEESTABLISHED(tp->t_state)) {
12200 			if ((tlen == 0) && (SEQ_LT(save_start, save_rnxt))) {
12201 				/*
12202 				 * DSACK actually handled in the fastpath
12203 				 * above.
12204 				 */
12205 				tcp_update_sack_list(tp, save_start,
12206 				    save_start + save_tlen);
12207 			} else if ((tlen > 0) && SEQ_GT(tp->rcv_nxt, save_rnxt)) {
12208 				if ((tp->rcv_numsacks >= 1) &&
12209 				    (tp->sackblks[0].end == save_start)) {
12210 					/*
12211 					 * Partial overlap, recorded at todrop
12212 					 * above.
12213 					 */
12214 					tcp_update_sack_list(tp,
12215 					    tp->sackblks[0].start,
12216 					    tp->sackblks[0].end);
12217 				} else {
12218 					tcp_update_dsack_list(tp, save_start,
12219 					    save_start + save_tlen);
12220 				}
12221 			} else if (tlen >= save_tlen) {
12222 				/* Update of sackblks. */
12223 				tcp_update_dsack_list(tp, save_start,
12224 				    save_start + save_tlen);
12225 			} else if (tlen > 0) {
12226 				tcp_update_dsack_list(tp, save_start,
12227 				    save_start + tlen);
12228 			}
12229 		}
12230 	} else {
12231 		m_freem(m);
12232 		thflags &= ~TH_FIN;
12233 	}
12234 
12235 	/*
12236 	 * If FIN is received ACK the FIN and let the user know that the
12237 	 * connection is closing.
12238 	 */
12239 	if (thflags & TH_FIN) {
12240 		if (TCPS_HAVERCVDFIN(tp->t_state) == 0) {
12241 			/* The socket upcall is handled by socantrcvmore. */
12242 			socantrcvmore(so);
12243 			/*
12244 			 * If connection is half-synchronized (ie NEEDSYN
12245 			 * flag on) then delay ACK, so it may be piggybacked
12246 			 * when SYN is sent. Otherwise, since we received a
12247 			 * FIN then no more input can be expected, send ACK
12248 			 * now.
12249 			 */
12250 			if (tp->t_flags & TF_NEEDSYN) {
12251 				rack_timer_cancel(tp, rack,
12252 				    rack->r_ctl.rc_rcvtime, __LINE__);
12253 				tp->t_flags |= TF_DELACK;
12254 			} else {
12255 				tp->t_flags |= TF_ACKNOW;
12256 			}
12257 			tp->rcv_nxt++;
12258 		}
12259 		switch (tp->t_state) {
12260 			/*
12261 			 * In SYN_RECEIVED and ESTABLISHED STATES enter the
12262 			 * CLOSE_WAIT state.
12263 			 */
12264 		case TCPS_SYN_RECEIVED:
12265 			tp->t_starttime = ticks;
12266 			/* FALLTHROUGH */
12267 		case TCPS_ESTABLISHED:
12268 			rack_timer_cancel(tp, rack,
12269 			    rack->r_ctl.rc_rcvtime, __LINE__);
12270 			tcp_state_change(tp, TCPS_CLOSE_WAIT);
12271 			break;
12272 
12273 			/*
12274 			 * If still in FIN_WAIT_1 STATE FIN has not been
12275 			 * acked so enter the CLOSING state.
12276 			 */
12277 		case TCPS_FIN_WAIT_1:
12278 			rack_timer_cancel(tp, rack,
12279 			    rack->r_ctl.rc_rcvtime, __LINE__);
12280 			tcp_state_change(tp, TCPS_CLOSING);
12281 			break;
12282 
12283 			/*
12284 			 * In FIN_WAIT_2 state enter the TIME_WAIT state,
12285 			 * starting the time-wait timer, turning off the
12286 			 * other standard timers.
12287 			 */
12288 		case TCPS_FIN_WAIT_2:
12289 			rack_timer_cancel(tp, rack,
12290 			    rack->r_ctl.rc_rcvtime, __LINE__);
12291 			tcp_twstart(tp);
12292 			return (1);
12293 		}
12294 	}
12295 	/*
12296 	 * Return any desired output.
12297 	 */
12298 	if ((tp->t_flags & TF_ACKNOW) ||
12299 	    (sbavail(&so->so_snd) > (tp->snd_max - tp->snd_una))) {
12300 		rack->r_wanted_output = 1;
12301 	}
12302 	return (0);
12303 }
12304 
12305 /*
12306  * Here nothing is really faster, its just that we
12307  * have broken out the fast-data path also just like
12308  * the fast-ack.
12309  */
12310 static int
12311 rack_do_fastnewdata(struct mbuf *m, struct tcphdr *th, struct socket *so,
12312     struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen,
12313     uint32_t tiwin, int32_t nxt_pkt, uint8_t iptos)
12314 {
12315 	int32_t nsegs;
12316 	int32_t newsize = 0;	/* automatic sockbuf scaling */
12317 	struct tcp_rack *rack;
12318 #ifdef NETFLIX_SB_LIMITS
12319 	u_int mcnt, appended;
12320 #endif
12321 
12322 	/*
12323 	 * If last ACK falls within this segment's sequence numbers, record
12324 	 * the timestamp. NOTE that the test is modified according to the
12325 	 * latest proposal of the tcplw@cray.com list (Braden 1993/04/26).
12326 	 */
12327 	if (__predict_false(th->th_seq != tp->rcv_nxt)) {
12328 		return (0);
12329 	}
12330 	if (tiwin && tiwin != tp->snd_wnd) {
12331 		return (0);
12332 	}
12333 	if (__predict_false((tp->t_flags & (TF_NEEDSYN | TF_NEEDFIN)))) {
12334 		return (0);
12335 	}
12336 	if (__predict_false((to->to_flags & TOF_TS) &&
12337 	    (TSTMP_LT(to->to_tsval, tp->ts_recent)))) {
12338 		return (0);
12339 	}
12340 	if (__predict_false((th->th_ack != tp->snd_una))) {
12341 		return (0);
12342 	}
12343 	if (__predict_false(tlen > sbspace(&so->so_rcv))) {
12344 		return (0);
12345 	}
12346 	if ((to->to_flags & TOF_TS) != 0 &&
12347 	    SEQ_LEQ(th->th_seq, tp->last_ack_sent)) {
12348 		tp->ts_recent_age = tcp_ts_getticks();
12349 		tp->ts_recent = to->to_tsval;
12350 	}
12351 	rack = (struct tcp_rack *)tp->t_fb_ptr;
12352 	/*
12353 	 * This is a pure, in-sequence data packet with nothing on the
12354 	 * reassembly queue and we have enough buffer space to take it.
12355 	 */
12356 	nsegs = max(1, m->m_pkthdr.lro_nsegs);
12357 
12358 #ifdef NETFLIX_SB_LIMITS
12359 	if (so->so_rcv.sb_shlim) {
12360 		mcnt = m_memcnt(m);
12361 		appended = 0;
12362 		if (counter_fo_get(so->so_rcv.sb_shlim, mcnt,
12363 		    CFO_NOSLEEP, NULL) == false) {
12364 			counter_u64_add(tcp_sb_shlim_fails, 1);
12365 			m_freem(m);
12366 			return (1);
12367 		}
12368 	}
12369 #endif
12370 	/* Clean receiver SACK report if present */
12371 	if (tp->rcv_numsacks)
12372 		tcp_clean_sackreport(tp);
12373 	KMOD_TCPSTAT_INC(tcps_preddat);
12374 	tp->rcv_nxt += tlen;
12375 	if (tlen &&
12376 	    ((tp->t_flags2 & TF2_FBYTES_COMPLETE) == 0) &&
12377 	    (tp->t_fbyte_in == 0)) {
12378 		tp->t_fbyte_in = ticks;
12379 		if (tp->t_fbyte_in == 0)
12380 			tp->t_fbyte_in = 1;
12381 		if (tp->t_fbyte_out && tp->t_fbyte_in)
12382 			tp->t_flags2 |= TF2_FBYTES_COMPLETE;
12383 	}
12384 	/*
12385 	 * Pull snd_wl1 up to prevent seq wrap relative to th_seq.
12386 	 */
12387 	tp->snd_wl1 = th->th_seq;
12388 	/*
12389 	 * Pull rcv_up up to prevent seq wrap relative to rcv_nxt.
12390 	 */
12391 	tp->rcv_up = tp->rcv_nxt;
12392 	KMOD_TCPSTAT_ADD(tcps_rcvpack, nsegs);
12393 	KMOD_TCPSTAT_ADD(tcps_rcvbyte, tlen);
12394 	newsize = tcp_autorcvbuf(m, th, so, tp, tlen);
12395 
12396 	/* Add data to socket buffer. */
12397 	SOCK_RECVBUF_LOCK(so);
12398 	if (so->so_rcv.sb_state & SBS_CANTRCVMORE) {
12399 		m_freem(m);
12400 	} else {
12401 		/*
12402 		 * Set new socket buffer size. Give up when limit is
12403 		 * reached.
12404 		 */
12405 		if (newsize)
12406 			if (!sbreserve_locked(so, SO_RCV, newsize, NULL))
12407 				so->so_rcv.sb_flags &= ~SB_AUTOSIZE;
12408 		m_adj(m, drop_hdrlen);	/* delayed header drop */
12409 #ifdef NETFLIX_SB_LIMITS
12410 		appended =
12411 #endif
12412 			sbappendstream_locked(&so->so_rcv, m, 0);
12413 		ctf_calc_rwin(so, tp);
12414 	}
12415 	rack_log_wakeup(tp,rack, &so->so_rcv, tlen, 1);
12416 	/* NB: sorwakeup_locked() does an implicit unlock. */
12417 	sorwakeup_locked(so);
12418 #ifdef NETFLIX_SB_LIMITS
12419 	if (so->so_rcv.sb_shlim && mcnt != appended)
12420 		counter_fo_release(so->so_rcv.sb_shlim, mcnt - appended);
12421 #endif
12422 	rack_handle_delayed_ack(tp, rack, tlen, 0);
12423 	if (tp->snd_una == tp->snd_max)
12424 		sack_filter_clear(&rack->r_ctl.rack_sf, tp->snd_una);
12425 	return (1);
12426 }
12427 
12428 /*
12429  * This subfunction is used to try to highly optimize the
12430  * fast path. We again allow window updates that are
12431  * in sequence to remain in the fast-path. We also add
12432  * in the __predict's to attempt to help the compiler.
12433  * Note that if we return a 0, then we can *not* process
12434  * it and the caller should push the packet into the
12435  * slow-path.
12436  */
12437 static int
12438 rack_fastack(struct mbuf *m, struct tcphdr *th, struct socket *so,
12439     struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen,
12440     uint32_t tiwin, int32_t nxt_pkt, uint32_t cts)
12441 {
12442 	int32_t acked;
12443 	int32_t nsegs;
12444 	int32_t under_pacing = 0;
12445 	struct tcp_rack *rack;
12446 
12447 	if (__predict_false(SEQ_LEQ(th->th_ack, tp->snd_una))) {
12448 		/* Old ack, behind (or duplicate to) the last one rcv'd */
12449 		return (0);
12450 	}
12451 	if (__predict_false(SEQ_GT(th->th_ack, tp->snd_max))) {
12452 		/* Above what we have sent? */
12453 		return (0);
12454 	}
12455 	if (__predict_false(tiwin == 0)) {
12456 		/* zero window */
12457 		return (0);
12458 	}
12459 	if (__predict_false(tp->t_flags & (TF_NEEDSYN | TF_NEEDFIN))) {
12460 		/* We need a SYN or a FIN, unlikely.. */
12461 		return (0);
12462 	}
12463 	if ((to->to_flags & TOF_TS) && __predict_false(TSTMP_LT(to->to_tsval, tp->ts_recent))) {
12464 		/* Timestamp is behind .. old ack with seq wrap? */
12465 		return (0);
12466 	}
12467 	if (__predict_false(IN_RECOVERY(tp->t_flags))) {
12468 		/* Still recovering */
12469 		return (0);
12470 	}
12471 	rack = (struct tcp_rack *)tp->t_fb_ptr;
12472 	if (rack->r_ctl.rc_sacked) {
12473 		/* We have sack holes on our scoreboard */
12474 		return (0);
12475 	}
12476 	/* Ok if we reach here, we can process a fast-ack */
12477 	if (rack->gp_ready &&
12478 	    (rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT)) {
12479 		under_pacing = 1;
12480 	}
12481 	nsegs = max(1, m->m_pkthdr.lro_nsegs);
12482 	rack_log_ack(tp, to, th, 0, 0, NULL, NULL);
12483 	/* Did the window get updated? */
12484 	if (tiwin != tp->snd_wnd) {
12485 		tp->snd_wnd = tiwin;
12486 		rack_validate_fo_sendwin_up(tp, rack);
12487 		tp->snd_wl1 = th->th_seq;
12488 		if (tp->snd_wnd > tp->max_sndwnd)
12489 			tp->max_sndwnd = tp->snd_wnd;
12490 	}
12491 	/* Do we exit persists? */
12492 	if ((rack->rc_in_persist != 0) &&
12493 	    (tp->snd_wnd >= min((rack->r_ctl.rc_high_rwnd/2),
12494 			       rack->r_ctl.rc_pace_min_segs))) {
12495 		rack_exit_persist(tp, rack, cts);
12496 	}
12497 	/* Do we enter persists? */
12498 	if ((rack->rc_in_persist == 0) &&
12499 	    (tp->snd_wnd < min((rack->r_ctl.rc_high_rwnd/2), rack->r_ctl.rc_pace_min_segs)) &&
12500 	    TCPS_HAVEESTABLISHED(tp->t_state) &&
12501 	    ((tp->snd_max == tp->snd_una) || rack->rc_has_collapsed) &&
12502 	    sbavail(&tptosocket(tp)->so_snd) &&
12503 	    (sbavail(&tptosocket(tp)->so_snd) > tp->snd_wnd)) {
12504 		/*
12505 		 * Here the rwnd is less than
12506 		 * the pacing size, we are established,
12507 		 * nothing is outstanding, and there is
12508 		 * data to send. Enter persists.
12509 		 */
12510 		rack_enter_persist(tp, rack, rack->r_ctl.rc_rcvtime, th->th_ack);
12511 	}
12512 	/*
12513 	 * If last ACK falls within this segment's sequence numbers, record
12514 	 * the timestamp. NOTE that the test is modified according to the
12515 	 * latest proposal of the tcplw@cray.com list (Braden 1993/04/26).
12516 	 */
12517 	if ((to->to_flags & TOF_TS) != 0 &&
12518 	    SEQ_LEQ(th->th_seq, tp->last_ack_sent)) {
12519 		tp->ts_recent_age = tcp_ts_getticks();
12520 		tp->ts_recent = to->to_tsval;
12521 	}
12522 	/*
12523 	 * This is a pure ack for outstanding data.
12524 	 */
12525 	KMOD_TCPSTAT_INC(tcps_predack);
12526 
12527 	/*
12528 	 * "bad retransmit" recovery.
12529 	 */
12530 	if ((tp->t_flags & TF_PREVVALID) &&
12531 	    ((tp->t_flags & TF_RCVD_TSTMP) == 0)) {
12532 		tp->t_flags &= ~TF_PREVVALID;
12533 		if (tp->t_rxtshift == 1 &&
12534 		    (int)(ticks - tp->t_badrxtwin) < 0)
12535 			rack_cong_signal(tp, CC_RTO_ERR, th->th_ack, __LINE__);
12536 	}
12537 	/*
12538 	 * Recalculate the transmit timer / rtt.
12539 	 *
12540 	 * Some boxes send broken timestamp replies during the SYN+ACK
12541 	 * phase, ignore timestamps of 0 or we could calculate a huge RTT
12542 	 * and blow up the retransmit timer.
12543 	 */
12544 	acked = BYTES_THIS_ACK(tp, th);
12545 
12546 #ifdef TCP_HHOOK
12547 	/* Run HHOOK_TCP_ESTABLISHED_IN helper hooks. */
12548 	hhook_run_tcp_est_in(tp, th, to);
12549 #endif
12550 	KMOD_TCPSTAT_ADD(tcps_rcvackpack, nsegs);
12551 	KMOD_TCPSTAT_ADD(tcps_rcvackbyte, acked);
12552 	if (acked) {
12553 		struct mbuf *mfree;
12554 
12555 		rack_ack_received(tp, rack, th->th_ack, nsegs, CC_ACK, 0);
12556 		SOCK_SENDBUF_LOCK(so);
12557 		mfree = sbcut_locked(&so->so_snd, acked);
12558 		tp->snd_una = th->th_ack;
12559 		/* Note we want to hold the sb lock through the sendmap adjust */
12560 		rack_adjust_sendmap_head(rack, &so->so_snd);
12561 		/* Wake up the socket if we have room to write more */
12562 		rack_log_wakeup(tp,rack, &so->so_snd, acked, 2);
12563 		sowwakeup_locked(so);
12564 		m_freem(mfree);
12565 		tp->t_rxtshift = 0;
12566 		RACK_TCPT_RANGESET(tp->t_rxtcur, RACK_REXMTVAL(tp),
12567 			      rack_rto_min, rack_rto_max, rack->r_ctl.timer_slop);
12568 		rack->rc_tlp_in_progress = 0;
12569 		rack->r_ctl.rc_tlp_cnt_out = 0;
12570 		/*
12571 		 * If it is the RXT timer we want to
12572 		 * stop it, so we can restart a TLP.
12573 		 */
12574 		if (rack->r_ctl.rc_hpts_flags & PACE_TMR_RXT)
12575 			rack_timer_cancel(tp, rack, rack->r_ctl.rc_rcvtime, __LINE__);
12576 
12577 #ifdef TCP_REQUEST_TRK
12578 		rack_req_check_for_comp(rack, th->th_ack);
12579 #endif
12580 	}
12581 	/*
12582 	 * Let the congestion control algorithm update congestion control
12583 	 * related information. This typically means increasing the
12584 	 * congestion window.
12585 	 */
12586 	if (tp->snd_wnd < ctf_outstanding(tp)) {
12587 		/* The peer collapsed the window */
12588 		rack_collapsed_window(rack, ctf_outstanding(tp), th->th_ack, __LINE__);
12589 	} else if (rack->rc_has_collapsed)
12590 		rack_un_collapse_window(rack, __LINE__);
12591 	if ((rack->r_collapse_point_valid) &&
12592 	    (SEQ_GT(tp->snd_una, rack->r_ctl.high_collapse_point)))
12593 		rack->r_collapse_point_valid = 0;
12594 	/*
12595 	 * Pull snd_wl2 up to prevent seq wrap relative to th_ack.
12596 	 */
12597 	tp->snd_wl2 = th->th_ack;
12598 	tp->t_dupacks = 0;
12599 	m_freem(m);
12600 	/* ND6_HINT(tp);	 *//* Some progress has been made. */
12601 
12602 	/*
12603 	 * If all outstanding data are acked, stop retransmit timer,
12604 	 * otherwise restart timer using current (possibly backed-off)
12605 	 * value. If process is waiting for space, wakeup/selwakeup/signal.
12606 	 * If data are ready to send, let tcp_output decide between more
12607 	 * output or persist.
12608 	 */
12609 	if (under_pacing &&
12610 	    (rack->use_fixed_rate == 0) &&
12611 	    (rack->in_probe_rtt == 0) &&
12612 	    rack->rc_gp_dyn_mul &&
12613 	    rack->rc_always_pace) {
12614 		/* Check if we are dragging bottom */
12615 		rack_check_bottom_drag(tp, rack, so);
12616 	}
12617 	if (tp->snd_una == tp->snd_max) {
12618 		tp->t_flags &= ~TF_PREVVALID;
12619 		rack->r_ctl.retran_during_recovery = 0;
12620 		rack->rc_suspicious = 0;
12621 		rack->r_ctl.dsack_byte_cnt = 0;
12622 		rack->r_ctl.rc_went_idle_time = tcp_get_usecs(NULL);
12623 		if (rack->r_ctl.rc_went_idle_time == 0)
12624 			rack->r_ctl.rc_went_idle_time = 1;
12625 		rack_log_progress_event(rack, tp, 0, PROGRESS_CLEAR, __LINE__);
12626 		if (sbavail(&tptosocket(tp)->so_snd) == 0)
12627 			tp->t_acktime = 0;
12628 		rack_timer_cancel(tp, rack, rack->r_ctl.rc_rcvtime, __LINE__);
12629 	}
12630 	if (acked && rack->r_fast_output)
12631 		rack_gain_for_fastoutput(rack, tp, so, (uint32_t)acked);
12632 	if (sbavail(&so->so_snd)) {
12633 		rack->r_wanted_output = 1;
12634 	}
12635 	return (1);
12636 }
12637 
12638 /*
12639  * Return value of 1, the TCB is unlocked and most
12640  * likely gone, return value of 0, the TCP is still
12641  * locked.
12642  */
12643 static int
12644 rack_do_syn_sent(struct mbuf *m, struct tcphdr *th, struct socket *so,
12645     struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen,
12646     uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos)
12647 {
12648 	int32_t ret_val = 0;
12649 	int32_t orig_tlen = tlen;
12650 	int32_t todrop;
12651 	int32_t ourfinisacked = 0;
12652 	struct tcp_rack *rack;
12653 
12654 	INP_WLOCK_ASSERT(tptoinpcb(tp));
12655 
12656 	ctf_calc_rwin(so, tp);
12657 	/*
12658 	 * If the state is SYN_SENT: if seg contains an ACK, but not for our
12659 	 * SYN, drop the input. if seg contains a RST, then drop the
12660 	 * connection. if seg does not contain SYN, then drop it. Otherwise
12661 	 * this is an acceptable SYN segment initialize tp->rcv_nxt and
12662 	 * tp->irs if seg contains ack then advance tp->snd_una if seg
12663 	 * contains an ECE and ECN support is enabled, the stream is ECN
12664 	 * capable. if SYN has been acked change to ESTABLISHED else
12665 	 * SYN_RCVD state arrange for segment to be acked (eventually)
12666 	 * continue processing rest of data/controls.
12667 	 */
12668 	if ((thflags & TH_ACK) &&
12669 	    (SEQ_LEQ(th->th_ack, tp->iss) ||
12670 	    SEQ_GT(th->th_ack, tp->snd_max))) {
12671 		tcp_log_end_status(tp, TCP_EI_STATUS_RST_IN_FRONT);
12672 		ctf_do_dropwithreset(m, tp, th, tlen);
12673 		return (1);
12674 	}
12675 	if ((thflags & (TH_ACK | TH_RST)) == (TH_ACK | TH_RST)) {
12676 		TCP_PROBE5(connect__refused, NULL, tp,
12677 		    mtod(m, const char *), tp, th);
12678 		tp = tcp_drop(tp, ECONNREFUSED);
12679 		ctf_do_drop(m, tp);
12680 		return (1);
12681 	}
12682 	if (thflags & TH_RST) {
12683 		ctf_do_drop(m, tp);
12684 		return (1);
12685 	}
12686 	if (!(thflags & TH_SYN)) {
12687 		ctf_do_drop(m, tp);
12688 		return (1);
12689 	}
12690 	tp->irs = th->th_seq;
12691 	tcp_rcvseqinit(tp);
12692 	rack = (struct tcp_rack *)tp->t_fb_ptr;
12693 	if (thflags & TH_ACK) {
12694 		int tfo_partial = 0;
12695 
12696 		KMOD_TCPSTAT_INC(tcps_connects);
12697 		soisconnected(so);
12698 #ifdef MAC
12699 		mac_socketpeer_set_from_mbuf(m, so);
12700 #endif
12701 		/* Do window scaling on this connection? */
12702 		if ((tp->t_flags & (TF_RCVD_SCALE | TF_REQ_SCALE)) ==
12703 		    (TF_RCVD_SCALE | TF_REQ_SCALE)) {
12704 			tp->rcv_scale = tp->request_r_scale;
12705 		}
12706 		tp->rcv_adv += min(tp->rcv_wnd,
12707 		    TCP_MAXWIN << tp->rcv_scale);
12708 		/*
12709 		 * If not all the data that was sent in the TFO SYN
12710 		 * has been acked, resend the remainder right away.
12711 		 */
12712 		if ((tp->t_flags & TF_FASTOPEN) &&
12713 		    (tp->snd_una != tp->snd_max)) {
12714 			/* Was it a partial ack? */
12715 			if (SEQ_LT(th->th_ack, tp->snd_max))
12716 				tfo_partial = 1;
12717 		}
12718 		/*
12719 		 * If there's data, delay ACK; if there's also a FIN ACKNOW
12720 		 * will be turned on later.
12721 		 */
12722 		if (DELAY_ACK(tp, tlen) && tlen != 0 && !tfo_partial) {
12723 			rack_timer_cancel(tp, rack,
12724 					  rack->r_ctl.rc_rcvtime, __LINE__);
12725 			tp->t_flags |= TF_DELACK;
12726 		} else {
12727 			rack->r_wanted_output = 1;
12728 			tp->t_flags |= TF_ACKNOW;
12729 		}
12730 
12731 		tcp_ecn_input_syn_sent(tp, thflags, iptos);
12732 
12733 		if (SEQ_GT(th->th_ack, tp->snd_una)) {
12734 			/*
12735 			 * We advance snd_una for the
12736 			 * fast open case. If th_ack is
12737 			 * acknowledging data beyond
12738 			 * snd_una we can't just call
12739 			 * ack-processing since the
12740 			 * data stream in our send-map
12741 			 * will start at snd_una + 1 (one
12742 			 * beyond the SYN). If its just
12743 			 * equal we don't need to do that
12744 			 * and there is no send_map.
12745 			 */
12746 			tp->snd_una++;
12747 			if (tfo_partial && (SEQ_GT(tp->snd_max, tp->snd_una))) {
12748 				/*
12749 				 * We sent a SYN with data, and thus have a
12750 				 * sendmap entry with a SYN set. Lets find it
12751 				 * and take off the send bit and the byte and
12752 				 * set it up to be what we send (send it next).
12753 				 */
12754 				struct rack_sendmap *rsm;
12755 
12756 				rsm = tqhash_min(rack->r_ctl.tqh);
12757 				if (rsm) {
12758 					if (rsm->r_flags & RACK_HAS_SYN) {
12759 						rsm->r_flags &= ~RACK_HAS_SYN;
12760 						rsm->r_start++;
12761 					}
12762 					rack->r_ctl.rc_resend = rsm;
12763 				}
12764 			}
12765 		}
12766 		/*
12767 		 * Received <SYN,ACK> in SYN_SENT[*] state. Transitions:
12768 		 * SYN_SENT  --> ESTABLISHED SYN_SENT* --> FIN_WAIT_1
12769 		 */
12770 		tp->t_starttime = ticks;
12771 		if (tp->t_flags & TF_NEEDFIN) {
12772 			tcp_state_change(tp, TCPS_FIN_WAIT_1);
12773 			tp->t_flags &= ~TF_NEEDFIN;
12774 			thflags &= ~TH_SYN;
12775 		} else {
12776 			tcp_state_change(tp, TCPS_ESTABLISHED);
12777 			TCP_PROBE5(connect__established, NULL, tp,
12778 			    mtod(m, const char *), tp, th);
12779 			rack_cc_conn_init(tp);
12780 		}
12781 	} else {
12782 		/*
12783 		 * Received initial SYN in SYN-SENT[*] state => simultaneous
12784 		 * open.  If segment contains CC option and there is a
12785 		 * cached CC, apply TAO test. If it succeeds, connection is *
12786 		 * half-synchronized. Otherwise, do 3-way handshake:
12787 		 * SYN-SENT -> SYN-RECEIVED SYN-SENT* -> SYN-RECEIVED* If
12788 		 * there was no CC option, clear cached CC value.
12789 		 */
12790 		tp->t_flags |= (TF_ACKNOW | TF_NEEDSYN | TF_SONOTCONN);
12791 		tcp_state_change(tp, TCPS_SYN_RECEIVED);
12792 	}
12793 	/*
12794 	 * Advance th->th_seq to correspond to first data byte. If data,
12795 	 * trim to stay within window, dropping FIN if necessary.
12796 	 */
12797 	th->th_seq++;
12798 	if (tlen > tp->rcv_wnd) {
12799 		todrop = tlen - tp->rcv_wnd;
12800 		m_adj(m, -todrop);
12801 		tlen = tp->rcv_wnd;
12802 		thflags &= ~TH_FIN;
12803 		KMOD_TCPSTAT_INC(tcps_rcvpackafterwin);
12804 		KMOD_TCPSTAT_ADD(tcps_rcvbyteafterwin, todrop);
12805 	}
12806 	tp->snd_wl1 = th->th_seq - 1;
12807 	tp->rcv_up = th->th_seq;
12808 	/*
12809 	 * Client side of transaction: already sent SYN and data. If the
12810 	 * remote host used T/TCP to validate the SYN, our data will be
12811 	 * ACK'd; if so, enter normal data segment processing in the middle
12812 	 * of step 5, ack processing. Otherwise, goto step 6.
12813 	 */
12814 	if (thflags & TH_ACK) {
12815 		/* For syn-sent we need to possibly update the rtt */
12816 		if ((to->to_flags & TOF_TS) != 0 && to->to_tsecr) {
12817 			uint32_t t, mcts;
12818 
12819 			mcts = tcp_ts_getticks();
12820 			t = (mcts - to->to_tsecr) * HPTS_USEC_IN_MSEC;
12821 			if (!tp->t_rttlow || tp->t_rttlow > t)
12822 				tp->t_rttlow = t;
12823 			rack_log_rtt_sample_calc(rack, t, (to->to_tsecr * 1000), (mcts * 1000), 4);
12824 			tcp_rack_xmit_timer(rack, t + 1, 1, t, 0, NULL, 2);
12825 			tcp_rack_xmit_timer_commit(rack, tp);
12826 		}
12827 		if (rack_process_ack(m, th, so, tp, to, tiwin, tlen, &ourfinisacked, thflags, &ret_val, orig_tlen))
12828 			return (ret_val);
12829 		/* We may have changed to FIN_WAIT_1 above */
12830 		if (tp->t_state == TCPS_FIN_WAIT_1) {
12831 			/*
12832 			 * In FIN_WAIT_1 STATE in addition to the processing
12833 			 * for the ESTABLISHED state if our FIN is now
12834 			 * acknowledged then enter FIN_WAIT_2.
12835 			 */
12836 			if (ourfinisacked) {
12837 				/*
12838 				 * If we can't receive any more data, then
12839 				 * closing user can proceed. Starting the
12840 				 * timer is contrary to the specification,
12841 				 * but if we don't get a FIN we'll hang
12842 				 * forever.
12843 				 *
12844 				 * XXXjl: we should release the tp also, and
12845 				 * use a compressed state.
12846 				 */
12847 				if (so->so_rcv.sb_state & SBS_CANTRCVMORE) {
12848 					soisdisconnected(so);
12849 					tcp_timer_activate(tp, TT_2MSL,
12850 					    (tcp_fast_finwait2_recycle ?
12851 					    tcp_finwait2_timeout :
12852 					    TP_MAXIDLE(tp)));
12853 				}
12854 				tcp_state_change(tp, TCPS_FIN_WAIT_2);
12855 			}
12856 		}
12857 	}
12858 	return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
12859 	   tiwin, thflags, nxt_pkt));
12860 }
12861 
12862 /*
12863  * Return value of 1, the TCB is unlocked and most
12864  * likely gone, return value of 0, the TCP is still
12865  * locked.
12866  */
12867 static int
12868 rack_do_syn_recv(struct mbuf *m, struct tcphdr *th, struct socket *so,
12869     struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen,
12870     uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos)
12871 {
12872 	struct tcp_rack *rack;
12873 	int32_t orig_tlen = tlen;
12874 	int32_t ret_val = 0;
12875 	int32_t ourfinisacked = 0;
12876 
12877 	rack = (struct tcp_rack *)tp->t_fb_ptr;
12878 	ctf_calc_rwin(so, tp);
12879 	if ((thflags & TH_RST) ||
12880 	    (tp->t_fin_is_rst && (thflags & TH_FIN)))
12881 		return (ctf_process_rst(m, th, so, tp));
12882 	if ((thflags & TH_ACK) &&
12883 	    (SEQ_LEQ(th->th_ack, tp->snd_una) ||
12884 	    SEQ_GT(th->th_ack, tp->snd_max))) {
12885 		tcp_log_end_status(tp, TCP_EI_STATUS_RST_IN_FRONT);
12886 		ctf_do_dropwithreset(m, tp, th, tlen);
12887 		return (1);
12888 	}
12889 	if (tp->t_flags & TF_FASTOPEN) {
12890 		/*
12891 		 * When a TFO connection is in SYN_RECEIVED, the
12892 		 * only valid packets are the initial SYN, a
12893 		 * retransmit/copy of the initial SYN (possibly with
12894 		 * a subset of the original data), a valid ACK, a
12895 		 * FIN, or a RST.
12896 		 */
12897 		if ((thflags & (TH_SYN | TH_ACK)) == (TH_SYN | TH_ACK)) {
12898 			tcp_log_end_status(tp, TCP_EI_STATUS_RST_IN_FRONT);
12899 			ctf_do_dropwithreset(m, tp, th, tlen);
12900 			return (1);
12901 		} else if (thflags & TH_SYN) {
12902 			/* non-initial SYN is ignored */
12903 			if ((rack->r_ctl.rc_hpts_flags & PACE_TMR_RXT) ||
12904 			    (rack->r_ctl.rc_hpts_flags & PACE_TMR_TLP) ||
12905 			    (rack->r_ctl.rc_hpts_flags & PACE_TMR_RACK)) {
12906 				ctf_do_drop(m, NULL);
12907 				return (0);
12908 			}
12909 		} else if (!(thflags & (TH_ACK | TH_FIN | TH_RST))) {
12910 			ctf_do_drop(m, NULL);
12911 			return (0);
12912 		}
12913 	}
12914 
12915 	/*
12916 	 * RFC 1323 PAWS: If we have a timestamp reply on this segment and
12917 	 * it's less than ts_recent, drop it.
12918 	 */
12919 	if ((to->to_flags & TOF_TS) != 0 && tp->ts_recent &&
12920 	    TSTMP_LT(to->to_tsval, tp->ts_recent)) {
12921 		if (ctf_ts_check(m, th, tp, tlen, thflags, &ret_val))
12922 			return (ret_val);
12923 	}
12924 	/*
12925 	 * In the SYN-RECEIVED state, validate that the packet belongs to
12926 	 * this connection before trimming the data to fit the receive
12927 	 * window.  Check the sequence number versus IRS since we know the
12928 	 * sequence numbers haven't wrapped.  This is a partial fix for the
12929 	 * "LAND" DoS attack.
12930 	 */
12931 	if (SEQ_LT(th->th_seq, tp->irs)) {
12932 		tcp_log_end_status(tp, TCP_EI_STATUS_RST_IN_FRONT);
12933 		ctf_do_dropwithreset(m, tp, th, tlen);
12934 		return (1);
12935 	}
12936 	if (ctf_drop_checks(to, m, th, tp, &tlen, &thflags, &drop_hdrlen, &ret_val)) {
12937 		return (ret_val);
12938 	}
12939 	/*
12940 	 * If last ACK falls within this segment's sequence numbers, record
12941 	 * its timestamp. NOTE: 1) That the test incorporates suggestions
12942 	 * from the latest proposal of the tcplw@cray.com list (Braden
12943 	 * 1993/04/26). 2) That updating only on newer timestamps interferes
12944 	 * with our earlier PAWS tests, so this check should be solely
12945 	 * predicated on the sequence space of this segment. 3) That we
12946 	 * modify the segment boundary check to be Last.ACK.Sent <= SEG.SEQ
12947 	 * + SEG.Len  instead of RFC1323's Last.ACK.Sent < SEG.SEQ +
12948 	 * SEG.Len, This modified check allows us to overcome RFC1323's
12949 	 * limitations as described in Stevens TCP/IP Illustrated Vol. 2
12950 	 * p.869. In such cases, we can still calculate the RTT correctly
12951 	 * when RCV.NXT == Last.ACK.Sent.
12952 	 */
12953 	if ((to->to_flags & TOF_TS) != 0 &&
12954 	    SEQ_LEQ(th->th_seq, tp->last_ack_sent) &&
12955 	    SEQ_LEQ(tp->last_ack_sent, th->th_seq + tlen +
12956 	    ((thflags & (TH_SYN | TH_FIN)) != 0))) {
12957 		tp->ts_recent_age = tcp_ts_getticks();
12958 		tp->ts_recent = to->to_tsval;
12959 	}
12960 	tp->snd_wnd = tiwin;
12961 	rack_validate_fo_sendwin_up(tp, rack);
12962 	/*
12963 	 * If the ACK bit is off:  if in SYN-RECEIVED state or SENDSYN flag
12964 	 * is on (half-synchronized state), then queue data for later
12965 	 * processing; else drop segment and return.
12966 	 */
12967 	if ((thflags & TH_ACK) == 0) {
12968 		if (tp->t_flags & TF_FASTOPEN) {
12969 			rack_cc_conn_init(tp);
12970 		}
12971 		return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
12972 		    tiwin, thflags, nxt_pkt));
12973 	}
12974 	KMOD_TCPSTAT_INC(tcps_connects);
12975 	if (tp->t_flags & TF_SONOTCONN) {
12976 		tp->t_flags &= ~TF_SONOTCONN;
12977 		soisconnected(so);
12978 	}
12979 	/* Do window scaling? */
12980 	if ((tp->t_flags & (TF_RCVD_SCALE | TF_REQ_SCALE)) ==
12981 	    (TF_RCVD_SCALE | TF_REQ_SCALE)) {
12982 		tp->rcv_scale = tp->request_r_scale;
12983 	}
12984 	/*
12985 	 * Make transitions: SYN-RECEIVED  -> ESTABLISHED SYN-RECEIVED* ->
12986 	 * FIN-WAIT-1
12987 	 */
12988 	tp->t_starttime = ticks;
12989 	if ((tp->t_flags & TF_FASTOPEN) && tp->t_tfo_pending) {
12990 		tcp_fastopen_decrement_counter(tp->t_tfo_pending);
12991 		tp->t_tfo_pending = NULL;
12992 	}
12993 	if (tp->t_flags & TF_NEEDFIN) {
12994 		tcp_state_change(tp, TCPS_FIN_WAIT_1);
12995 		tp->t_flags &= ~TF_NEEDFIN;
12996 	} else {
12997 		tcp_state_change(tp, TCPS_ESTABLISHED);
12998 		TCP_PROBE5(accept__established, NULL, tp,
12999 		    mtod(m, const char *), tp, th);
13000 		/*
13001 		 * TFO connections call cc_conn_init() during SYN
13002 		 * processing.  Calling it again here for such connections
13003 		 * is not harmless as it would undo the snd_cwnd reduction
13004 		 * that occurs when a TFO SYN|ACK is retransmitted.
13005 		 */
13006 		if (!(tp->t_flags & TF_FASTOPEN))
13007 			rack_cc_conn_init(tp);
13008 	}
13009 	/*
13010 	 * Account for the ACK of our SYN prior to
13011 	 * regular ACK processing below, except for
13012 	 * simultaneous SYN, which is handled later.
13013 	 */
13014 	if (SEQ_GT(th->th_ack, tp->snd_una) && !(tp->t_flags & TF_NEEDSYN))
13015 		tp->snd_una++;
13016 	/*
13017 	 * If segment contains data or ACK, will call tcp_reass() later; if
13018 	 * not, do so now to pass queued data to user.
13019 	 */
13020 	if (tlen == 0 && (thflags & TH_FIN) == 0) {
13021 		(void) tcp_reass(tp, (struct tcphdr *)0, NULL, 0,
13022 		    (struct mbuf *)0);
13023 		if (tp->t_flags & TF_WAKESOR) {
13024 			tp->t_flags &= ~TF_WAKESOR;
13025 			/* NB: sorwakeup_locked() does an implicit unlock. */
13026 			sorwakeup_locked(so);
13027 		}
13028 	}
13029 	tp->snd_wl1 = th->th_seq - 1;
13030 	/* For syn-recv we need to possibly update the rtt */
13031 	if ((to->to_flags & TOF_TS) != 0 && to->to_tsecr) {
13032 		uint32_t t, mcts;
13033 
13034 		mcts = tcp_ts_getticks();
13035 		t = (mcts - to->to_tsecr) * HPTS_USEC_IN_MSEC;
13036 		if (!tp->t_rttlow || tp->t_rttlow > t)
13037 			tp->t_rttlow = t;
13038 		rack_log_rtt_sample_calc(rack, t, (to->to_tsecr * 1000), (mcts * 1000), 5);
13039 		tcp_rack_xmit_timer(rack, t + 1, 1, t, 0, NULL, 2);
13040 		tcp_rack_xmit_timer_commit(rack, tp);
13041 	}
13042 	if (rack_process_ack(m, th, so, tp, to, tiwin, tlen, &ourfinisacked, thflags, &ret_val, orig_tlen)) {
13043 		return (ret_val);
13044 	}
13045 	if (tp->t_state == TCPS_FIN_WAIT_1) {
13046 		/* We could have went to FIN_WAIT_1 (or EST) above */
13047 		/*
13048 		 * In FIN_WAIT_1 STATE in addition to the processing for the
13049 		 * ESTABLISHED state if our FIN is now acknowledged then
13050 		 * enter FIN_WAIT_2.
13051 		 */
13052 		if (ourfinisacked) {
13053 			/*
13054 			 * If we can't receive any more data, then closing
13055 			 * user can proceed. Starting the timer is contrary
13056 			 * to the specification, but if we don't get a FIN
13057 			 * we'll hang forever.
13058 			 *
13059 			 * XXXjl: we should release the tp also, and use a
13060 			 * compressed state.
13061 			 */
13062 			if (so->so_rcv.sb_state & SBS_CANTRCVMORE) {
13063 				soisdisconnected(so);
13064 				tcp_timer_activate(tp, TT_2MSL,
13065 				    (tcp_fast_finwait2_recycle ?
13066 				    tcp_finwait2_timeout :
13067 				    TP_MAXIDLE(tp)));
13068 			}
13069 			tcp_state_change(tp, TCPS_FIN_WAIT_2);
13070 		}
13071 	}
13072 	return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
13073 	    tiwin, thflags, nxt_pkt));
13074 }
13075 
13076 /*
13077  * Return value of 1, the TCB is unlocked and most
13078  * likely gone, return value of 0, the TCP is still
13079  * locked.
13080  */
13081 static int
13082 rack_do_established(struct mbuf *m, struct tcphdr *th, struct socket *so,
13083     struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen,
13084     uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos)
13085 {
13086 	int32_t ret_val = 0;
13087 	int32_t orig_tlen = tlen;
13088 	struct tcp_rack *rack;
13089 
13090 	/*
13091 	 * Header prediction: check for the two common cases of a
13092 	 * uni-directional data xfer.  If the packet has no control flags,
13093 	 * is in-sequence, the window didn't change and we're not
13094 	 * retransmitting, it's a candidate.  If the length is zero and the
13095 	 * ack moved forward, we're the sender side of the xfer.  Just free
13096 	 * the data acked & wake any higher level process that was blocked
13097 	 * waiting for space.  If the length is non-zero and the ack didn't
13098 	 * move, we're the receiver side.  If we're getting packets in-order
13099 	 * (the reassembly queue is empty), add the data toc The socket
13100 	 * buffer and note that we need a delayed ack. Make sure that the
13101 	 * hidden state-flags are also off. Since we check for
13102 	 * TCPS_ESTABLISHED first, it can only be TH_NEEDSYN.
13103 	 */
13104 	rack = (struct tcp_rack *)tp->t_fb_ptr;
13105 	if (__predict_true(((to->to_flags & TOF_SACK) == 0)) &&
13106 	    __predict_true((thflags & (TH_SYN | TH_FIN | TH_RST | TH_ACK)) == TH_ACK) &&
13107 	    __predict_true(SEGQ_EMPTY(tp)) &&
13108 	    __predict_true(th->th_seq == tp->rcv_nxt)) {
13109 		if (tlen == 0) {
13110 			if (rack_fastack(m, th, so, tp, to, drop_hdrlen, tlen,
13111 			    tiwin, nxt_pkt, rack->r_ctl.rc_rcvtime)) {
13112 				return (0);
13113 			}
13114 		} else {
13115 			if (rack_do_fastnewdata(m, th, so, tp, to, drop_hdrlen, tlen,
13116 			    tiwin, nxt_pkt, iptos)) {
13117 				return (0);
13118 			}
13119 		}
13120 	}
13121 	ctf_calc_rwin(so, tp);
13122 
13123 	if ((thflags & TH_RST) ||
13124 	    (tp->t_fin_is_rst && (thflags & TH_FIN)))
13125 		return (ctf_process_rst(m, th, so, tp));
13126 
13127 	/*
13128 	 * RFC5961 Section 4.2 Send challenge ACK for any SYN in
13129 	 * synchronized state.
13130 	 */
13131 	if (thflags & TH_SYN) {
13132 		ctf_challenge_ack(m, th, tp, iptos, &ret_val);
13133 		return (ret_val);
13134 	}
13135 	/*
13136 	 * RFC 1323 PAWS: If we have a timestamp reply on this segment and
13137 	 * it's less than ts_recent, drop it.
13138 	 */
13139 	if ((to->to_flags & TOF_TS) != 0 && tp->ts_recent &&
13140 	    TSTMP_LT(to->to_tsval, tp->ts_recent)) {
13141 		if (ctf_ts_check(m, th, tp, tlen, thflags, &ret_val))
13142 			return (ret_val);
13143 	}
13144 	if (ctf_drop_checks(to, m, th, tp, &tlen, &thflags, &drop_hdrlen, &ret_val)) {
13145 		return (ret_val);
13146 	}
13147 	/*
13148 	 * If last ACK falls within this segment's sequence numbers, record
13149 	 * its timestamp. NOTE: 1) That the test incorporates suggestions
13150 	 * from the latest proposal of the tcplw@cray.com list (Braden
13151 	 * 1993/04/26). 2) That updating only on newer timestamps interferes
13152 	 * with our earlier PAWS tests, so this check should be solely
13153 	 * predicated on the sequence space of this segment. 3) That we
13154 	 * modify the segment boundary check to be Last.ACK.Sent <= SEG.SEQ
13155 	 * + SEG.Len  instead of RFC1323's Last.ACK.Sent < SEG.SEQ +
13156 	 * SEG.Len, This modified check allows us to overcome RFC1323's
13157 	 * limitations as described in Stevens TCP/IP Illustrated Vol. 2
13158 	 * p.869. In such cases, we can still calculate the RTT correctly
13159 	 * when RCV.NXT == Last.ACK.Sent.
13160 	 */
13161 	if ((to->to_flags & TOF_TS) != 0 &&
13162 	    SEQ_LEQ(th->th_seq, tp->last_ack_sent) &&
13163 	    SEQ_LEQ(tp->last_ack_sent, th->th_seq + tlen +
13164 	    ((thflags & (TH_SYN | TH_FIN)) != 0))) {
13165 		tp->ts_recent_age = tcp_ts_getticks();
13166 		tp->ts_recent = to->to_tsval;
13167 	}
13168 	/*
13169 	 * If the ACK bit is off:  if in SYN-RECEIVED state or SENDSYN flag
13170 	 * is on (half-synchronized state), then queue data for later
13171 	 * processing; else drop segment and return.
13172 	 */
13173 	if ((thflags & TH_ACK) == 0) {
13174 		if (tp->t_flags & TF_NEEDSYN) {
13175 			return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
13176 			    tiwin, thflags, nxt_pkt));
13177 
13178 		} else if (tp->t_flags & TF_ACKNOW) {
13179 			ctf_do_dropafterack(m, tp, th, thflags, tlen, &ret_val);
13180 			((struct tcp_rack *)tp->t_fb_ptr)->r_wanted_output = 1;
13181 			return (ret_val);
13182 		} else {
13183 			ctf_do_drop(m, NULL);
13184 			return (0);
13185 		}
13186 	}
13187 	/*
13188 	 * Ack processing.
13189 	 */
13190 	if (rack_process_ack(m, th, so, tp, to, tiwin, tlen, NULL, thflags, &ret_val, orig_tlen)) {
13191 		return (ret_val);
13192 	}
13193 	if (sbavail(&so->so_snd)) {
13194 		if (ctf_progress_timeout_check(tp, true)) {
13195 			rack_log_progress_event(rack, tp, tick, PROGRESS_DROP, __LINE__);
13196 			ctf_do_dropwithreset_conn(m, tp, th, tlen);
13197 			return (1);
13198 		}
13199 	}
13200 	/* State changes only happen in rack_process_data() */
13201 	return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
13202 	    tiwin, thflags, nxt_pkt));
13203 }
13204 
13205 /*
13206  * Return value of 1, the TCB is unlocked and most
13207  * likely gone, return value of 0, the TCP is still
13208  * locked.
13209  */
13210 static int
13211 rack_do_close_wait(struct mbuf *m, struct tcphdr *th, struct socket *so,
13212     struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen,
13213     uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos)
13214 {
13215 	int32_t ret_val = 0;
13216 	int32_t orig_tlen = tlen;
13217 
13218 	ctf_calc_rwin(so, tp);
13219 	if ((thflags & TH_RST) ||
13220 	    (tp->t_fin_is_rst && (thflags & TH_FIN)))
13221 		return (ctf_process_rst(m, th, so, tp));
13222 	/*
13223 	 * RFC5961 Section 4.2 Send challenge ACK for any SYN in
13224 	 * synchronized state.
13225 	 */
13226 	if (thflags & TH_SYN) {
13227 		ctf_challenge_ack(m, th, tp, iptos, &ret_val);
13228 		return (ret_val);
13229 	}
13230 	/*
13231 	 * RFC 1323 PAWS: If we have a timestamp reply on this segment and
13232 	 * it's less than ts_recent, drop it.
13233 	 */
13234 	if ((to->to_flags & TOF_TS) != 0 && tp->ts_recent &&
13235 	    TSTMP_LT(to->to_tsval, tp->ts_recent)) {
13236 		if (ctf_ts_check(m, th, tp, tlen, thflags, &ret_val))
13237 			return (ret_val);
13238 	}
13239 	if (ctf_drop_checks(to, m, th, tp, &tlen, &thflags, &drop_hdrlen, &ret_val)) {
13240 		return (ret_val);
13241 	}
13242 	/*
13243 	 * If last ACK falls within this segment's sequence numbers, record
13244 	 * its timestamp. NOTE: 1) That the test incorporates suggestions
13245 	 * from the latest proposal of the tcplw@cray.com list (Braden
13246 	 * 1993/04/26). 2) That updating only on newer timestamps interferes
13247 	 * with our earlier PAWS tests, so this check should be solely
13248 	 * predicated on the sequence space of this segment. 3) That we
13249 	 * modify the segment boundary check to be Last.ACK.Sent <= SEG.SEQ
13250 	 * + SEG.Len  instead of RFC1323's Last.ACK.Sent < SEG.SEQ +
13251 	 * SEG.Len, This modified check allows us to overcome RFC1323's
13252 	 * limitations as described in Stevens TCP/IP Illustrated Vol. 2
13253 	 * p.869. In such cases, we can still calculate the RTT correctly
13254 	 * when RCV.NXT == Last.ACK.Sent.
13255 	 */
13256 	if ((to->to_flags & TOF_TS) != 0 &&
13257 	    SEQ_LEQ(th->th_seq, tp->last_ack_sent) &&
13258 	    SEQ_LEQ(tp->last_ack_sent, th->th_seq + tlen +
13259 	    ((thflags & (TH_SYN | TH_FIN)) != 0))) {
13260 		tp->ts_recent_age = tcp_ts_getticks();
13261 		tp->ts_recent = to->to_tsval;
13262 	}
13263 	/*
13264 	 * If the ACK bit is off:  if in SYN-RECEIVED state or SENDSYN flag
13265 	 * is on (half-synchronized state), then queue data for later
13266 	 * processing; else drop segment and return.
13267 	 */
13268 	if ((thflags & TH_ACK) == 0) {
13269 		if (tp->t_flags & TF_NEEDSYN) {
13270 			return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
13271 			    tiwin, thflags, nxt_pkt));
13272 
13273 		} else if (tp->t_flags & TF_ACKNOW) {
13274 			ctf_do_dropafterack(m, tp, th, thflags, tlen, &ret_val);
13275 			((struct tcp_rack *)tp->t_fb_ptr)->r_wanted_output = 1;
13276 			return (ret_val);
13277 		} else {
13278 			ctf_do_drop(m, NULL);
13279 			return (0);
13280 		}
13281 	}
13282 	/*
13283 	 * Ack processing.
13284 	 */
13285 	if (rack_process_ack(m, th, so, tp, to, tiwin, tlen, NULL, thflags, &ret_val, orig_tlen)) {
13286 		return (ret_val);
13287 	}
13288 	if (sbavail(&so->so_snd)) {
13289 		if (ctf_progress_timeout_check(tp, true)) {
13290 			rack_log_progress_event((struct tcp_rack *)tp->t_fb_ptr,
13291 						tp, tick, PROGRESS_DROP, __LINE__);
13292 			ctf_do_dropwithreset_conn(m, tp, th, tlen);
13293 			return (1);
13294 		}
13295 	}
13296 	return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
13297 	    tiwin, thflags, nxt_pkt));
13298 }
13299 
13300 static int
13301 rack_check_data_after_close(struct mbuf *m,
13302     struct tcpcb *tp, int32_t *tlen, struct tcphdr *th, struct socket *so)
13303 {
13304 	struct tcp_rack *rack;
13305 
13306 	rack = (struct tcp_rack *)tp->t_fb_ptr;
13307 	if (rack->rc_allow_data_af_clo == 0) {
13308 	close_now:
13309 		tcp_log_end_status(tp, TCP_EI_STATUS_DATA_A_CLOSE);
13310 		/* tcp_close will kill the inp pre-log the Reset */
13311 		tcp_log_end_status(tp, TCP_EI_STATUS_SERVER_RST);
13312 		tp = tcp_close(tp);
13313 		KMOD_TCPSTAT_INC(tcps_rcvafterclose);
13314 		ctf_do_dropwithreset(m, tp, th, *tlen);
13315 		return (1);
13316 	}
13317 	if (sbavail(&so->so_snd) == 0)
13318 		goto close_now;
13319 	/* Ok we allow data that is ignored and a followup reset */
13320 	tcp_log_end_status(tp, TCP_EI_STATUS_DATA_A_CLOSE);
13321 	tp->rcv_nxt = th->th_seq + *tlen;
13322 	tp->t_flags2 |= TF2_DROP_AF_DATA;
13323 	rack->r_wanted_output = 1;
13324 	*tlen = 0;
13325 	return (0);
13326 }
13327 
13328 /*
13329  * Return value of 1, the TCB is unlocked and most
13330  * likely gone, return value of 0, the TCP is still
13331  * locked.
13332  */
13333 static int
13334 rack_do_fin_wait_1(struct mbuf *m, struct tcphdr *th, struct socket *so,
13335     struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen,
13336     uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos)
13337 {
13338 	int32_t ret_val = 0;
13339 	int32_t orig_tlen = tlen;
13340 	int32_t ourfinisacked = 0;
13341 
13342 	ctf_calc_rwin(so, tp);
13343 
13344 	if ((thflags & TH_RST) ||
13345 	    (tp->t_fin_is_rst && (thflags & TH_FIN)))
13346 		return (ctf_process_rst(m, th, so, tp));
13347 	/*
13348 	 * RFC5961 Section 4.2 Send challenge ACK for any SYN in
13349 	 * synchronized state.
13350 	 */
13351 	if (thflags & TH_SYN) {
13352 		ctf_challenge_ack(m, th, tp, iptos, &ret_val);
13353 		return (ret_val);
13354 	}
13355 	/*
13356 	 * RFC 1323 PAWS: If we have a timestamp reply on this segment and
13357 	 * it's less than ts_recent, drop it.
13358 	 */
13359 	if ((to->to_flags & TOF_TS) != 0 && tp->ts_recent &&
13360 	    TSTMP_LT(to->to_tsval, tp->ts_recent)) {
13361 		if (ctf_ts_check(m, th, tp, tlen, thflags, &ret_val))
13362 			return (ret_val);
13363 	}
13364 	if (ctf_drop_checks(to, m, th, tp, &tlen, &thflags, &drop_hdrlen, &ret_val)) {
13365 		return (ret_val);
13366 	}
13367 	/*
13368 	 * If new data are received on a connection after the user processes
13369 	 * are gone, then RST the other end.
13370 	 */
13371 	if ((tp->t_flags & TF_CLOSED) && tlen &&
13372 	    rack_check_data_after_close(m, tp, &tlen, th, so))
13373 		return (1);
13374 	/*
13375 	 * If last ACK falls within this segment's sequence numbers, record
13376 	 * its timestamp. NOTE: 1) That the test incorporates suggestions
13377 	 * from the latest proposal of the tcplw@cray.com list (Braden
13378 	 * 1993/04/26). 2) That updating only on newer timestamps interferes
13379 	 * with our earlier PAWS tests, so this check should be solely
13380 	 * predicated on the sequence space of this segment. 3) That we
13381 	 * modify the segment boundary check to be Last.ACK.Sent <= SEG.SEQ
13382 	 * + SEG.Len  instead of RFC1323's Last.ACK.Sent < SEG.SEQ +
13383 	 * SEG.Len, This modified check allows us to overcome RFC1323's
13384 	 * limitations as described in Stevens TCP/IP Illustrated Vol. 2
13385 	 * p.869. In such cases, we can still calculate the RTT correctly
13386 	 * when RCV.NXT == Last.ACK.Sent.
13387 	 */
13388 	if ((to->to_flags & TOF_TS) != 0 &&
13389 	    SEQ_LEQ(th->th_seq, tp->last_ack_sent) &&
13390 	    SEQ_LEQ(tp->last_ack_sent, th->th_seq + tlen +
13391 	    ((thflags & (TH_SYN | TH_FIN)) != 0))) {
13392 		tp->ts_recent_age = tcp_ts_getticks();
13393 		tp->ts_recent = to->to_tsval;
13394 	}
13395 	/*
13396 	 * If the ACK bit is off:  if in SYN-RECEIVED state or SENDSYN flag
13397 	 * is on (half-synchronized state), then queue data for later
13398 	 * processing; else drop segment and return.
13399 	 */
13400 	if ((thflags & TH_ACK) == 0) {
13401 		if (tp->t_flags & TF_NEEDSYN) {
13402 			return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
13403 			    tiwin, thflags, nxt_pkt));
13404 		} else if (tp->t_flags & TF_ACKNOW) {
13405 			ctf_do_dropafterack(m, tp, th, thflags, tlen, &ret_val);
13406 			((struct tcp_rack *)tp->t_fb_ptr)->r_wanted_output = 1;
13407 			return (ret_val);
13408 		} else {
13409 			ctf_do_drop(m, NULL);
13410 			return (0);
13411 		}
13412 	}
13413 	/*
13414 	 * Ack processing.
13415 	 */
13416 	if (rack_process_ack(m, th, so, tp, to, tiwin, tlen, &ourfinisacked, thflags, &ret_val, orig_tlen)) {
13417 		return (ret_val);
13418 	}
13419 	if (ourfinisacked) {
13420 		/*
13421 		 * If we can't receive any more data, then closing user can
13422 		 * proceed. Starting the timer is contrary to the
13423 		 * specification, but if we don't get a FIN we'll hang
13424 		 * forever.
13425 		 *
13426 		 * XXXjl: we should release the tp also, and use a
13427 		 * compressed state.
13428 		 */
13429 		if (so->so_rcv.sb_state & SBS_CANTRCVMORE) {
13430 			soisdisconnected(so);
13431 			tcp_timer_activate(tp, TT_2MSL,
13432 			    (tcp_fast_finwait2_recycle ?
13433 			    tcp_finwait2_timeout :
13434 			    TP_MAXIDLE(tp)));
13435 		}
13436 		tcp_state_change(tp, TCPS_FIN_WAIT_2);
13437 	}
13438 	if (sbavail(&so->so_snd)) {
13439 		if (ctf_progress_timeout_check(tp, true)) {
13440 			rack_log_progress_event((struct tcp_rack *)tp->t_fb_ptr,
13441 						tp, tick, PROGRESS_DROP, __LINE__);
13442 			ctf_do_dropwithreset_conn(m, tp, th, tlen);
13443 			return (1);
13444 		}
13445 	}
13446 	return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
13447 	    tiwin, thflags, nxt_pkt));
13448 }
13449 
13450 /*
13451  * Return value of 1, the TCB is unlocked and most
13452  * likely gone, return value of 0, the TCP is still
13453  * locked.
13454  */
13455 static int
13456 rack_do_closing(struct mbuf *m, struct tcphdr *th, struct socket *so,
13457     struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen,
13458     uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos)
13459 {
13460 	int32_t ret_val = 0;
13461 	int32_t orig_tlen = tlen;
13462 	int32_t ourfinisacked = 0;
13463 
13464 	ctf_calc_rwin(so, tp);
13465 
13466 	if ((thflags & TH_RST) ||
13467 	    (tp->t_fin_is_rst && (thflags & TH_FIN)))
13468 		return (ctf_process_rst(m, th, so, tp));
13469 	/*
13470 	 * RFC5961 Section 4.2 Send challenge ACK for any SYN in
13471 	 * synchronized state.
13472 	 */
13473 	if (thflags & TH_SYN) {
13474 		ctf_challenge_ack(m, th, tp, iptos, &ret_val);
13475 		return (ret_val);
13476 	}
13477 	/*
13478 	 * RFC 1323 PAWS: If we have a timestamp reply on this segment and
13479 	 * it's less than ts_recent, drop it.
13480 	 */
13481 	if ((to->to_flags & TOF_TS) != 0 && tp->ts_recent &&
13482 	    TSTMP_LT(to->to_tsval, tp->ts_recent)) {
13483 		if (ctf_ts_check(m, th, tp, tlen, thflags, &ret_val))
13484 			return (ret_val);
13485 	}
13486 	if (ctf_drop_checks(to, m, th, tp, &tlen, &thflags, &drop_hdrlen, &ret_val)) {
13487 		return (ret_val);
13488 	}
13489 	/*
13490 	 * If last ACK falls within this segment's sequence numbers, record
13491 	 * its timestamp. NOTE: 1) That the test incorporates suggestions
13492 	 * from the latest proposal of the tcplw@cray.com list (Braden
13493 	 * 1993/04/26). 2) That updating only on newer timestamps interferes
13494 	 * with our earlier PAWS tests, so this check should be solely
13495 	 * predicated on the sequence space of this segment. 3) That we
13496 	 * modify the segment boundary check to be Last.ACK.Sent <= SEG.SEQ
13497 	 * + SEG.Len  instead of RFC1323's Last.ACK.Sent < SEG.SEQ +
13498 	 * SEG.Len, This modified check allows us to overcome RFC1323's
13499 	 * limitations as described in Stevens TCP/IP Illustrated Vol. 2
13500 	 * p.869. In such cases, we can still calculate the RTT correctly
13501 	 * when RCV.NXT == Last.ACK.Sent.
13502 	 */
13503 	if ((to->to_flags & TOF_TS) != 0 &&
13504 	    SEQ_LEQ(th->th_seq, tp->last_ack_sent) &&
13505 	    SEQ_LEQ(tp->last_ack_sent, th->th_seq + tlen +
13506 	    ((thflags & (TH_SYN | TH_FIN)) != 0))) {
13507 		tp->ts_recent_age = tcp_ts_getticks();
13508 		tp->ts_recent = to->to_tsval;
13509 	}
13510 	/*
13511 	 * If the ACK bit is off:  if in SYN-RECEIVED state or SENDSYN flag
13512 	 * is on (half-synchronized state), then queue data for later
13513 	 * processing; else drop segment and return.
13514 	 */
13515 	if ((thflags & TH_ACK) == 0) {
13516 		if (tp->t_flags & TF_NEEDSYN) {
13517 			return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
13518 			    tiwin, thflags, nxt_pkt));
13519 		} else if (tp->t_flags & TF_ACKNOW) {
13520 			ctf_do_dropafterack(m, tp, th, thflags, tlen, &ret_val);
13521 			((struct tcp_rack *)tp->t_fb_ptr)->r_wanted_output = 1;
13522 			return (ret_val);
13523 		} else {
13524 			ctf_do_drop(m, NULL);
13525 			return (0);
13526 		}
13527 	}
13528 	/*
13529 	 * Ack processing.
13530 	 */
13531 	if (rack_process_ack(m, th, so, tp, to, tiwin, tlen, &ourfinisacked, thflags, &ret_val, orig_tlen)) {
13532 		return (ret_val);
13533 	}
13534 	if (ourfinisacked) {
13535 		tcp_twstart(tp);
13536 		m_freem(m);
13537 		return (1);
13538 	}
13539 	if (sbavail(&so->so_snd)) {
13540 		if (ctf_progress_timeout_check(tp, true)) {
13541 			rack_log_progress_event((struct tcp_rack *)tp->t_fb_ptr,
13542 						tp, tick, PROGRESS_DROP, __LINE__);
13543 			ctf_do_dropwithreset_conn(m, tp, th, tlen);
13544 			return (1);
13545 		}
13546 	}
13547 	return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
13548 	    tiwin, thflags, nxt_pkt));
13549 }
13550 
13551 /*
13552  * Return value of 1, the TCB is unlocked and most
13553  * likely gone, return value of 0, the TCP is still
13554  * locked.
13555  */
13556 static int
13557 rack_do_lastack(struct mbuf *m, struct tcphdr *th, struct socket *so,
13558     struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen,
13559     uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos)
13560 {
13561 	int32_t ret_val = 0;
13562 	int32_t orig_tlen;
13563 	int32_t ourfinisacked = 0;
13564 
13565 	ctf_calc_rwin(so, tp);
13566 
13567 	if ((thflags & TH_RST) ||
13568 	    (tp->t_fin_is_rst && (thflags & TH_FIN)))
13569 		return (ctf_process_rst(m, th, so, tp));
13570 	/*
13571 	 * RFC5961 Section 4.2 Send challenge ACK for any SYN in
13572 	 * synchronized state.
13573 	 */
13574 	if (thflags & TH_SYN) {
13575 		ctf_challenge_ack(m, th, tp, iptos, &ret_val);
13576 		return (ret_val);
13577 	}
13578 	/*
13579 	 * RFC 1323 PAWS: If we have a timestamp reply on this segment and
13580 	 * it's less than ts_recent, drop it.
13581 	 */
13582 	if ((to->to_flags & TOF_TS) != 0 && tp->ts_recent &&
13583 	    TSTMP_LT(to->to_tsval, tp->ts_recent)) {
13584 		if (ctf_ts_check(m, th, tp, tlen, thflags, &ret_val))
13585 			return (ret_val);
13586 	}
13587 	orig_tlen = tlen;
13588 	if (ctf_drop_checks(to, m, th, tp, &tlen, &thflags, &drop_hdrlen, &ret_val)) {
13589 		return (ret_val);
13590 	}
13591 	/*
13592 	 * If last ACK falls within this segment's sequence numbers, record
13593 	 * its timestamp. NOTE: 1) That the test incorporates suggestions
13594 	 * from the latest proposal of the tcplw@cray.com list (Braden
13595 	 * 1993/04/26). 2) That updating only on newer timestamps interferes
13596 	 * with our earlier PAWS tests, so this check should be solely
13597 	 * predicated on the sequence space of this segment. 3) That we
13598 	 * modify the segment boundary check to be Last.ACK.Sent <= SEG.SEQ
13599 	 * + SEG.Len  instead of RFC1323's Last.ACK.Sent < SEG.SEQ +
13600 	 * SEG.Len, This modified check allows us to overcome RFC1323's
13601 	 * limitations as described in Stevens TCP/IP Illustrated Vol. 2
13602 	 * p.869. In such cases, we can still calculate the RTT correctly
13603 	 * when RCV.NXT == Last.ACK.Sent.
13604 	 */
13605 	if ((to->to_flags & TOF_TS) != 0 &&
13606 	    SEQ_LEQ(th->th_seq, tp->last_ack_sent) &&
13607 	    SEQ_LEQ(tp->last_ack_sent, th->th_seq + tlen +
13608 	    ((thflags & (TH_SYN | TH_FIN)) != 0))) {
13609 		tp->ts_recent_age = tcp_ts_getticks();
13610 		tp->ts_recent = to->to_tsval;
13611 	}
13612 	/*
13613 	 * If the ACK bit is off:  if in SYN-RECEIVED state or SENDSYN flag
13614 	 * is on (half-synchronized state), then queue data for later
13615 	 * processing; else drop segment and return.
13616 	 */
13617 	if ((thflags & TH_ACK) == 0) {
13618 		if (tp->t_flags & TF_NEEDSYN) {
13619 			return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
13620 			    tiwin, thflags, nxt_pkt));
13621 		} else if (tp->t_flags & TF_ACKNOW) {
13622 			ctf_do_dropafterack(m, tp, th, thflags, tlen, &ret_val);
13623 			((struct tcp_rack *)tp->t_fb_ptr)->r_wanted_output = 1;
13624 			return (ret_val);
13625 		} else {
13626 			ctf_do_drop(m, NULL);
13627 			return (0);
13628 		}
13629 	}
13630 	/*
13631 	 * case TCPS_LAST_ACK: Ack processing.
13632 	 */
13633 	if (rack_process_ack(m, th, so, tp, to, tiwin, tlen, &ourfinisacked, thflags, &ret_val, orig_tlen)) {
13634 		return (ret_val);
13635 	}
13636 	if (ourfinisacked) {
13637 		tp = tcp_close(tp);
13638 		ctf_do_drop(m, tp);
13639 		return (1);
13640 	}
13641 	if (sbavail(&so->so_snd)) {
13642 		if (ctf_progress_timeout_check(tp, true)) {
13643 			rack_log_progress_event((struct tcp_rack *)tp->t_fb_ptr,
13644 						tp, tick, PROGRESS_DROP, __LINE__);
13645 			ctf_do_dropwithreset_conn(m, tp, th, tlen);
13646 			return (1);
13647 		}
13648 	}
13649 	return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
13650 	    tiwin, thflags, nxt_pkt));
13651 }
13652 
13653 /*
13654  * Return value of 1, the TCB is unlocked and most
13655  * likely gone, return value of 0, the TCP is still
13656  * locked.
13657  */
13658 static int
13659 rack_do_fin_wait_2(struct mbuf *m, struct tcphdr *th, struct socket *so,
13660     struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen,
13661     uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos)
13662 {
13663 	int32_t ret_val = 0;
13664 	int32_t orig_tlen = tlen;
13665 	int32_t ourfinisacked = 0;
13666 
13667 	ctf_calc_rwin(so, tp);
13668 
13669 	/* Reset receive buffer auto scaling when not in bulk receive mode. */
13670 	if ((thflags & TH_RST) ||
13671 	    (tp->t_fin_is_rst && (thflags & TH_FIN)))
13672 		return (ctf_process_rst(m, th, so, tp));
13673 	/*
13674 	 * RFC5961 Section 4.2 Send challenge ACK for any SYN in
13675 	 * synchronized state.
13676 	 */
13677 	if (thflags & TH_SYN) {
13678 		ctf_challenge_ack(m, th, tp, iptos, &ret_val);
13679 		return (ret_val);
13680 	}
13681 	/*
13682 	 * RFC 1323 PAWS: If we have a timestamp reply on this segment and
13683 	 * it's less than ts_recent, drop it.
13684 	 */
13685 	if ((to->to_flags & TOF_TS) != 0 && tp->ts_recent &&
13686 	    TSTMP_LT(to->to_tsval, tp->ts_recent)) {
13687 		if (ctf_ts_check(m, th, tp, tlen, thflags, &ret_val))
13688 			return (ret_val);
13689 	}
13690 	if (ctf_drop_checks(to, m, th, tp, &tlen, &thflags, &drop_hdrlen, &ret_val)) {
13691 		return (ret_val);
13692 	}
13693 	/*
13694 	 * If new data are received on a connection after the user processes
13695 	 * are gone, then RST the other end.
13696 	 */
13697 	if ((tp->t_flags & TF_CLOSED) && tlen &&
13698 	    rack_check_data_after_close(m, tp, &tlen, th, so))
13699 		return (1);
13700 	/*
13701 	 * If last ACK falls within this segment's sequence numbers, record
13702 	 * its timestamp. NOTE: 1) That the test incorporates suggestions
13703 	 * from the latest proposal of the tcplw@cray.com list (Braden
13704 	 * 1993/04/26). 2) That updating only on newer timestamps interferes
13705 	 * with our earlier PAWS tests, so this check should be solely
13706 	 * predicated on the sequence space of this segment. 3) That we
13707 	 * modify the segment boundary check to be Last.ACK.Sent <= SEG.SEQ
13708 	 * + SEG.Len  instead of RFC1323's Last.ACK.Sent < SEG.SEQ +
13709 	 * SEG.Len, This modified check allows us to overcome RFC1323's
13710 	 * limitations as described in Stevens TCP/IP Illustrated Vol. 2
13711 	 * p.869. In such cases, we can still calculate the RTT correctly
13712 	 * when RCV.NXT == Last.ACK.Sent.
13713 	 */
13714 	if ((to->to_flags & TOF_TS) != 0 &&
13715 	    SEQ_LEQ(th->th_seq, tp->last_ack_sent) &&
13716 	    SEQ_LEQ(tp->last_ack_sent, th->th_seq + tlen +
13717 	    ((thflags & (TH_SYN | TH_FIN)) != 0))) {
13718 		tp->ts_recent_age = tcp_ts_getticks();
13719 		tp->ts_recent = to->to_tsval;
13720 	}
13721 	/*
13722 	 * If the ACK bit is off:  if in SYN-RECEIVED state or SENDSYN flag
13723 	 * is on (half-synchronized state), then queue data for later
13724 	 * processing; else drop segment and return.
13725 	 */
13726 	if ((thflags & TH_ACK) == 0) {
13727 		if (tp->t_flags & TF_NEEDSYN) {
13728 			return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
13729 			    tiwin, thflags, nxt_pkt));
13730 		} else if (tp->t_flags & TF_ACKNOW) {
13731 			ctf_do_dropafterack(m, tp, th, thflags, tlen, &ret_val);
13732 			((struct tcp_rack *)tp->t_fb_ptr)->r_wanted_output = 1;
13733 			return (ret_val);
13734 		} else {
13735 			ctf_do_drop(m, NULL);
13736 			return (0);
13737 		}
13738 	}
13739 	/*
13740 	 * Ack processing.
13741 	 */
13742 	if (rack_process_ack(m, th, so, tp, to, tiwin, tlen, &ourfinisacked, thflags, &ret_val, orig_tlen)) {
13743 		return (ret_val);
13744 	}
13745 	if (sbavail(&so->so_snd)) {
13746 		if (ctf_progress_timeout_check(tp, true)) {
13747 			rack_log_progress_event((struct tcp_rack *)tp->t_fb_ptr,
13748 						tp, tick, PROGRESS_DROP, __LINE__);
13749 			ctf_do_dropwithreset_conn(m, tp, th, tlen);
13750 			return (1);
13751 		}
13752 	}
13753 	return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
13754 	    tiwin, thflags, nxt_pkt));
13755 }
13756 
13757 static void inline
13758 rack_clear_rate_sample(struct tcp_rack *rack)
13759 {
13760 	rack->r_ctl.rack_rs.rs_flags = RACK_RTT_EMPTY;
13761 	rack->r_ctl.rack_rs.rs_rtt_cnt = 0;
13762 	rack->r_ctl.rack_rs.rs_rtt_tot = 0;
13763 }
13764 
13765 static void
13766 rack_set_pace_segments(struct tcpcb *tp, struct tcp_rack *rack, uint32_t line, uint64_t *fill_override)
13767 {
13768 	uint64_t bw_est, rate_wanted;
13769 	int chged = 0;
13770 	uint32_t user_max, orig_min, orig_max;
13771 
13772 #ifdef TCP_REQUEST_TRK
13773 	if (rack->rc_hybrid_mode &&
13774 	    (rack->r_ctl.rc_pace_max_segs != 0) &&
13775 	    (rack_hybrid_allow_set_maxseg == 1) &&
13776 	    (rack->r_ctl.rc_last_sft != NULL)) {
13777 		rack->r_ctl.rc_last_sft->hybrid_flags &= ~TCP_HYBRID_PACING_SETMSS;
13778 		return;
13779 	}
13780 #endif
13781 	orig_min = rack->r_ctl.rc_pace_min_segs;
13782 	orig_max = rack->r_ctl.rc_pace_max_segs;
13783 	user_max = ctf_fixed_maxseg(tp) * rack->rc_user_set_max_segs;
13784 	if (ctf_fixed_maxseg(tp) != rack->r_ctl.rc_pace_min_segs)
13785 		chged = 1;
13786 	rack->r_ctl.rc_pace_min_segs = ctf_fixed_maxseg(tp);
13787 	if (rack->use_fixed_rate || rack->rc_force_max_seg) {
13788 		if (user_max != rack->r_ctl.rc_pace_max_segs)
13789 			chged = 1;
13790 	}
13791 	if (rack->rc_force_max_seg) {
13792 		rack->r_ctl.rc_pace_max_segs = user_max;
13793 	} else if (rack->use_fixed_rate) {
13794 		bw_est = rack_get_bw(rack);
13795 		if ((rack->r_ctl.crte == NULL) ||
13796 		    (bw_est != rack->r_ctl.crte->rate)) {
13797 			rack->r_ctl.rc_pace_max_segs = user_max;
13798 		} else {
13799 			/* We are pacing right at the hardware rate */
13800 			uint32_t segsiz, pace_one;
13801 
13802 			if (rack_pace_one_seg ||
13803 			    (rack->r_ctl.rc_user_set_min_segs == 1))
13804 				pace_one = 1;
13805 			else
13806 				pace_one = 0;
13807 			segsiz = min(ctf_fixed_maxseg(tp),
13808 				     rack->r_ctl.rc_pace_min_segs);
13809 			rack->r_ctl.rc_pace_max_segs = tcp_get_pacing_burst_size_w_divisor(
13810 				tp, bw_est, segsiz, pace_one,
13811 				rack->r_ctl.crte, NULL, rack->r_ctl.pace_len_divisor);
13812 		}
13813 	} else if (rack->rc_always_pace) {
13814 		if (rack->r_ctl.gp_bw ||
13815 		    rack->r_ctl.init_rate) {
13816 			/* We have a rate of some sort set */
13817 			uint32_t  orig;
13818 
13819 			bw_est = rack_get_bw(rack);
13820 			orig = rack->r_ctl.rc_pace_max_segs;
13821 			if (fill_override)
13822 				rate_wanted = *fill_override;
13823 			else
13824 				rate_wanted = rack_get_gp_est(rack);
13825 			if (rate_wanted) {
13826 				/* We have something */
13827 				rack->r_ctl.rc_pace_max_segs = rack_get_pacing_len(rack,
13828 										   rate_wanted,
13829 										   ctf_fixed_maxseg(rack->rc_tp));
13830 			} else
13831 				rack->r_ctl.rc_pace_max_segs = rack->r_ctl.rc_pace_min_segs;
13832 			if (orig != rack->r_ctl.rc_pace_max_segs)
13833 				chged = 1;
13834 		} else if ((rack->r_ctl.gp_bw == 0) &&
13835 			   (rack->r_ctl.rc_pace_max_segs == 0)) {
13836 			/*
13837 			 * If we have nothing limit us to bursting
13838 			 * out IW sized pieces.
13839 			 */
13840 			chged = 1;
13841 			rack->r_ctl.rc_pace_max_segs = rc_init_window(rack);
13842 		}
13843 	}
13844 	if (rack->r_ctl.rc_pace_max_segs > PACE_MAX_IP_BYTES) {
13845 		chged = 1;
13846 		rack->r_ctl.rc_pace_max_segs = PACE_MAX_IP_BYTES;
13847 	}
13848 	if (chged)
13849 		rack_log_type_pacing_sizes(tp, rack, orig_min, orig_max, line, 2);
13850 }
13851 
13852 
13853 static void
13854 rack_init_fsb_block(struct tcpcb *tp, struct tcp_rack *rack, int32_t flags)
13855 {
13856 #ifdef INET6
13857 	struct ip6_hdr *ip6 = NULL;
13858 #endif
13859 #ifdef INET
13860 	struct ip *ip = NULL;
13861 #endif
13862 	struct udphdr *udp = NULL;
13863 
13864 	/* Ok lets fill in the fast block, it can only be used with no IP options! */
13865 #ifdef INET6
13866 	if (rack->r_is_v6) {
13867 		rack->r_ctl.fsb.tcp_ip_hdr_len = sizeof(struct ip6_hdr) + sizeof(struct tcphdr);
13868 		ip6 = (struct ip6_hdr *)rack->r_ctl.fsb.tcp_ip_hdr;
13869 		if (tp->t_port) {
13870 			rack->r_ctl.fsb.tcp_ip_hdr_len += sizeof(struct udphdr);
13871 			udp = (struct udphdr *)((caddr_t)ip6 + sizeof(struct ip6_hdr));
13872 			udp->uh_sport = htons(V_tcp_udp_tunneling_port);
13873 			udp->uh_dport = tp->t_port;
13874 			rack->r_ctl.fsb.udp = udp;
13875 			rack->r_ctl.fsb.th = (struct tcphdr *)(udp + 1);
13876 		} else
13877 		{
13878 			rack->r_ctl.fsb.th = (struct tcphdr *)(ip6 + 1);
13879 			rack->r_ctl.fsb.udp = NULL;
13880 		}
13881 		tcpip_fillheaders(rack->rc_inp,
13882 				  tp->t_port,
13883 				  ip6, rack->r_ctl.fsb.th);
13884 		rack->r_ctl.fsb.hoplimit = in6_selecthlim(rack->rc_inp, NULL);
13885 	} else
13886 #endif				/* INET6 */
13887 #ifdef INET
13888 	{
13889 		rack->r_ctl.fsb.tcp_ip_hdr_len = sizeof(struct tcpiphdr);
13890 		ip = (struct ip *)rack->r_ctl.fsb.tcp_ip_hdr;
13891 		if (tp->t_port) {
13892 			rack->r_ctl.fsb.tcp_ip_hdr_len += sizeof(struct udphdr);
13893 			udp = (struct udphdr *)((caddr_t)ip + sizeof(struct ip));
13894 			udp->uh_sport = htons(V_tcp_udp_tunneling_port);
13895 			udp->uh_dport = tp->t_port;
13896 			rack->r_ctl.fsb.udp = udp;
13897 			rack->r_ctl.fsb.th = (struct tcphdr *)(udp + 1);
13898 		} else
13899 		{
13900 			rack->r_ctl.fsb.udp = NULL;
13901 			rack->r_ctl.fsb.th = (struct tcphdr *)(ip + 1);
13902 		}
13903 		tcpip_fillheaders(rack->rc_inp,
13904 				  tp->t_port,
13905 				  ip, rack->r_ctl.fsb.th);
13906 		rack->r_ctl.fsb.hoplimit = tptoinpcb(tp)->inp_ip_ttl;
13907 	}
13908 #endif
13909 	rack->r_ctl.fsb.recwin = lmin(lmax(sbspace(&tptosocket(tp)->so_rcv), 0),
13910 	    (long)TCP_MAXWIN << tp->rcv_scale);
13911 	rack->r_fsb_inited = 1;
13912 }
13913 
13914 static int
13915 rack_init_fsb(struct tcpcb *tp, struct tcp_rack *rack)
13916 {
13917 	/*
13918 	 * Allocate the larger of spaces V6 if available else just
13919 	 * V4 and include udphdr (overbook)
13920 	 */
13921 #ifdef INET6
13922 	rack->r_ctl.fsb.tcp_ip_hdr_len = sizeof(struct ip6_hdr) + sizeof(struct tcphdr) + sizeof(struct udphdr);
13923 #else
13924 	rack->r_ctl.fsb.tcp_ip_hdr_len = sizeof(struct tcpiphdr) + sizeof(struct udphdr);
13925 #endif
13926 	rack->r_ctl.fsb.tcp_ip_hdr = malloc(rack->r_ctl.fsb.tcp_ip_hdr_len,
13927 					    M_TCPFSB, M_NOWAIT|M_ZERO);
13928 	if (rack->r_ctl.fsb.tcp_ip_hdr == NULL) {
13929 		return (ENOMEM);
13930 	}
13931 	rack->r_fsb_inited = 0;
13932 	return (0);
13933 }
13934 
13935 static void
13936 rack_log_hystart_event(struct tcp_rack *rack, uint32_t high_seq, uint8_t mod)
13937 {
13938 	/*
13939 	 * Types of logs (mod value)
13940 	 * 20 - Initial round setup
13941 	 * 21 - Rack declares a new round.
13942 	 */
13943 	struct tcpcb *tp;
13944 
13945 	tp = rack->rc_tp;
13946 	if (tcp_bblogging_on(tp)) {
13947 		union tcp_log_stackspecific log;
13948 		struct timeval tv;
13949 
13950 		memset(&log, 0, sizeof(log));
13951 		log.u_bbr.flex1 = rack->r_ctl.current_round;
13952 		log.u_bbr.flex2 = rack->r_ctl.roundends;
13953 		log.u_bbr.flex3 = high_seq;
13954 		log.u_bbr.flex4 = tp->snd_max;
13955 		log.u_bbr.flex8 = mod;
13956 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
13957 		log.u_bbr.cur_del_rate = rack->rc_tp->t_sndbytes;
13958 		log.u_bbr.delRate = rack->rc_tp->t_snd_rxt_bytes;
13959 		TCP_LOG_EVENTP(tp, NULL,
13960 		    &tptosocket(tp)->so_rcv,
13961 		    &tptosocket(tp)->so_snd,
13962 		    TCP_HYSTART, 0,
13963 		    0, &log, false, &tv);
13964 	}
13965 }
13966 
13967 static void
13968 rack_deferred_init(struct tcpcb *tp, struct tcp_rack *rack)
13969 {
13970 	rack->rack_deferred_inited = 1;
13971 	rack->r_ctl.roundends = tp->snd_max;
13972 	rack->r_ctl.rc_high_rwnd = tp->snd_wnd;
13973 	rack->r_ctl.cwnd_to_use = tp->snd_cwnd;
13974 }
13975 
13976 static void
13977 rack_init_retransmit_value(struct tcp_rack *rack, int ctl)
13978 {
13979 	/* Retransmit bit controls.
13980 	 *
13981 	 * The setting of these values control one of
13982 	 * three settings you can have and dictate
13983 	 * how rack does retransmissions. Note this
13984 	 * is in *any* mode i.e. pacing on or off DGP
13985 	 * fixed rate pacing, or just bursting rack.
13986 	 *
13987 	 * 1 - Use full sized retransmits i.e. limit
13988 	 *     the size to whatever the pace_max_segments
13989 	 *     size is.
13990 	 *
13991 	 * 2 - Use pacer min granularity as a guide to
13992 	 *     the size combined with the current calculated
13993 	 *     goodput b/w measurement. So for example if
13994 	 *     the goodput is measured at 20Mbps we would
13995 	 *     calculate 8125 (pacer minimum 250usec in
13996 	 *     that b/w) and then round it up to the next
13997 	 *     MSS i.e. for 1448 mss 6 MSS or 8688 bytes.
13998 	 *
13999 	 * 0 - The rack default 1 MSS (anything not 0/1/2
14000 	 *     fall here too if we are setting via rack_init()).
14001 	 *
14002 	 */
14003 	if (ctl == 1) {
14004 		rack->full_size_rxt = 1;
14005 		rack->shape_rxt_to_pacing_min  = 0;
14006 	} else if (ctl == 2) {
14007 		rack->full_size_rxt = 0;
14008 		rack->shape_rxt_to_pacing_min  = 1;
14009 	} else {
14010 		rack->full_size_rxt = 0;
14011 		rack->shape_rxt_to_pacing_min  = 0;
14012 	}
14013 }
14014 
14015 static void
14016 rack_log_chg_info(struct tcpcb *tp, struct tcp_rack *rack, uint8_t mod,
14017 		  uint32_t flex1,
14018 		  uint32_t flex2,
14019 		  uint32_t flex3)
14020 {
14021 	if (tcp_bblogging_on(rack->rc_tp)) {
14022 		union tcp_log_stackspecific log;
14023 		struct timeval tv;
14024 
14025 		memset(&log, 0, sizeof(log));
14026 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
14027 		log.u_bbr.flex8 = mod;
14028 		log.u_bbr.flex1 = flex1;
14029 		log.u_bbr.flex2 = flex2;
14030 		log.u_bbr.flex3 = flex3;
14031 		tcp_log_event(tp, NULL, NULL, NULL, TCP_CHG_QUERY, 0,
14032 			       0, &log, false, NULL, __func__, __LINE__, &tv);
14033 	}
14034 }
14035 
14036 static int
14037 rack_chg_query(struct tcpcb *tp, struct tcp_query_resp *reqr)
14038 {
14039 	struct tcp_rack *rack;
14040 	struct rack_sendmap *rsm;
14041 	int i;
14042 
14043 
14044 	rack = (struct tcp_rack *)tp->t_fb_ptr;
14045 	switch (reqr->req) {
14046 	case TCP_QUERY_SENDMAP:
14047 		if ((reqr->req_param == tp->snd_max) ||
14048 		    (tp->snd_max == tp->snd_una)){
14049 			/* Unlikely */
14050 			return (0);
14051 		}
14052 		rsm = tqhash_find(rack->r_ctl.tqh, reqr->req_param);
14053 		if (rsm == NULL) {
14054 			/* Can't find that seq -- unlikely */
14055 			return (0);
14056 		}
14057 		reqr->sendmap_start = rsm->r_start;
14058 		reqr->sendmap_end = rsm->r_end;
14059 		reqr->sendmap_send_cnt = rsm->r_rtr_cnt;
14060 		reqr->sendmap_fas = rsm->r_fas;
14061 		if (reqr->sendmap_send_cnt > SNDMAP_NRTX)
14062 			reqr->sendmap_send_cnt = SNDMAP_NRTX;
14063 		for(i=0; i<reqr->sendmap_send_cnt; i++)
14064 			reqr->sendmap_time[i] = rsm->r_tim_lastsent[i];
14065 		reqr->sendmap_ack_arrival = rsm->r_ack_arrival;
14066 		reqr->sendmap_flags = rsm->r_flags & SNDMAP_MASK;
14067 		reqr->sendmap_r_rtr_bytes = rsm->r_rtr_bytes;
14068 		reqr->sendmap_dupacks = rsm->r_dupack;
14069 		rack_log_chg_info(tp, rack, 1,
14070 				  rsm->r_start,
14071 				  rsm->r_end,
14072 				  rsm->r_flags);
14073 		return(1);
14074 		break;
14075 	case TCP_QUERY_TIMERS_UP:
14076 		if (rack->r_ctl.rc_hpts_flags == 0) {
14077 			/* no timers up */
14078 			return (0);
14079 		}
14080 		reqr->timer_hpts_flags = rack->r_ctl.rc_hpts_flags;
14081 		if (rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT) {
14082 			reqr->timer_pacing_to = rack->r_ctl.rc_last_output_to;
14083 		}
14084 		if (rack->r_ctl.rc_hpts_flags & PACE_TMR_MASK) {
14085 			reqr->timer_timer_exp = rack->r_ctl.rc_timer_exp;
14086 		}
14087 		rack_log_chg_info(tp, rack, 2,
14088 				  rack->r_ctl.rc_hpts_flags,
14089 				  rack->r_ctl.rc_last_output_to,
14090 				  rack->r_ctl.rc_timer_exp);
14091 		return (1);
14092 		break;
14093 	case TCP_QUERY_RACK_TIMES:
14094 		/* Reordering items */
14095 		reqr->rack_num_dsacks = rack->r_ctl.num_dsack;
14096 		reqr->rack_reorder_ts = rack->r_ctl.rc_reorder_ts;
14097 		/* Timerstamps and timers */
14098 		reqr->rack_rxt_last_time = rack->r_ctl.rc_tlp_rxt_last_time;
14099 		reqr->rack_min_rtt = rack->r_ctl.rc_rack_min_rtt;
14100 		reqr->rack_rtt = rack->rc_rack_rtt;
14101 		reqr->rack_tmit_time = rack->r_ctl.rc_rack_tmit_time;
14102 		reqr->rack_srtt_measured = rack->rc_srtt_measure_made;
14103 		/* PRR data */
14104 		reqr->rack_sacked = rack->r_ctl.rc_sacked;
14105 		reqr->rack_holes_rxt = rack->r_ctl.rc_holes_rxt;
14106 		reqr->rack_prr_delivered = rack->r_ctl.rc_prr_delivered;
14107 		reqr->rack_prr_recovery_fs = rack->r_ctl.rc_prr_recovery_fs;
14108 		reqr->rack_prr_sndcnt = rack->r_ctl.rc_prr_sndcnt;
14109 		reqr->rack_prr_out = rack->r_ctl.rc_prr_out;
14110 		/* TLP and persists info */
14111 		reqr->rack_tlp_out = rack->rc_tlp_in_progress;
14112 		reqr->rack_tlp_cnt_out = rack->r_ctl.rc_tlp_cnt_out;
14113 		if (rack->rc_in_persist) {
14114 			reqr->rack_time_went_idle = rack->r_ctl.rc_went_idle_time;
14115 			reqr->rack_in_persist = 1;
14116 		} else {
14117 			reqr->rack_time_went_idle = 0;
14118 			reqr->rack_in_persist = 0;
14119 		}
14120 		if (rack->r_wanted_output)
14121 			reqr->rack_wanted_output = 1;
14122 		else
14123 			reqr->rack_wanted_output = 0;
14124 		return (1);
14125 		break;
14126 	default:
14127 		return (-EINVAL);
14128 	}
14129 }
14130 
14131 static void
14132 rack_switch_failed(struct tcpcb *tp)
14133 {
14134 	/*
14135 	 * This method gets called if a stack switch was
14136 	 * attempted and it failed. We are left
14137 	 * but our hpts timers were stopped and we
14138 	 * need to validate time units and t_flags2.
14139 	 */
14140 	struct tcp_rack *rack;
14141 	struct timeval tv;
14142 	uint32_t cts;
14143 	uint32_t toval;
14144 	struct hpts_diag diag;
14145 
14146 	rack = (struct tcp_rack *)tp->t_fb_ptr;
14147 	tcp_change_time_units(tp, TCP_TMR_GRANULARITY_USEC);
14148 	if  (rack->r_mbuf_queue || rack->rc_always_pace || rack->r_use_cmp_ack)
14149 		tp->t_flags2 |= TF2_SUPPORTS_MBUFQ;
14150 	else
14151 		tp->t_flags2 &= ~TF2_SUPPORTS_MBUFQ;
14152 	if (rack->r_use_cmp_ack && TCPS_HAVEESTABLISHED(tp->t_state))
14153 		tp->t_flags2 |= TF2_MBUF_ACKCMP;
14154 	if (tp->t_in_hpts > IHPTS_NONE) {
14155 		/* Strange */
14156 		return;
14157 	}
14158 	cts = tcp_get_usecs(&tv);
14159 	if (rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT) {
14160 		if (TSTMP_GT(rack->r_ctl.rc_last_output_to, cts)) {
14161 			toval = rack->r_ctl.rc_last_output_to - cts;
14162 		} else {
14163 			/* one slot please */
14164 			toval = HPTS_USECS_PER_SLOT;
14165 		}
14166 	} else if (rack->r_ctl.rc_hpts_flags & PACE_TMR_MASK) {
14167 		if (TSTMP_GT(rack->r_ctl.rc_timer_exp, cts)) {
14168 			toval = rack->r_ctl.rc_timer_exp - cts;
14169 		} else {
14170 			/* one slot please */
14171 			toval = HPTS_USECS_PER_SLOT;
14172 		}
14173 	} else
14174 		toval = HPTS_USECS_PER_SLOT;
14175 	tcp_hpts_insert(tp, toval, &diag);
14176 	rack_log_hpts_diag(rack, cts, &diag, &tv);
14177 }
14178 
14179 static int
14180 rack_init_outstanding(struct tcpcb *tp, struct tcp_rack *rack, uint32_t us_cts, void *ptr)
14181 {
14182 	struct rack_sendmap *rsm, *ersm;
14183 	int insret __diagused;
14184 	/*
14185 	 * When initing outstanding, we must be quite careful
14186 	 * to not refer to tp->t_fb_ptr. This has the old rack
14187 	 * pointer in it, not the "new" one (when we are doing
14188 	 * a stack switch).
14189 	 */
14190 
14191 
14192 	if (tp->t_fb->tfb_chg_query == NULL) {
14193 		/* Create a send map for the current outstanding data */
14194 
14195 		rsm = rack_alloc(rack);
14196 		if (rsm == NULL) {
14197 			uma_zfree(rack_pcb_zone, ptr);
14198 			return (ENOMEM);
14199 		}
14200 		rsm->r_no_rtt_allowed = 1;
14201 		rsm->r_tim_lastsent[0] = rack_to_usec_ts(&rack->r_ctl.act_rcv_time);
14202 		rsm->r_rtr_cnt = 1;
14203 		rsm->r_rtr_bytes = 0;
14204 		if (tp->t_flags & TF_SENTFIN)
14205 			rsm->r_flags |= RACK_HAS_FIN;
14206 		rsm->r_end = tp->snd_max;
14207 		if (tp->snd_una == tp->iss) {
14208 			/* The data space is one beyond snd_una */
14209 			rsm->r_flags |= RACK_HAS_SYN;
14210 			rsm->r_start = tp->iss;
14211 			rsm->r_end = rsm->r_start + (tp->snd_max - tp->snd_una);
14212 		} else
14213 			rsm->r_start = tp->snd_una;
14214 		rsm->r_dupack = 0;
14215 		if (rack->rc_inp->inp_socket->so_snd.sb_mb != NULL) {
14216 			rsm->m = sbsndmbuf(&rack->rc_inp->inp_socket->so_snd, 0, &rsm->soff);
14217 			if (rsm->m) {
14218 				rsm->orig_m_len = rsm->m->m_len;
14219 				rsm->orig_t_space = M_TRAILINGROOM(rsm->m);
14220 			} else {
14221 				rsm->orig_m_len = 0;
14222 				rsm->orig_t_space = 0;
14223 			}
14224 		} else {
14225 			/*
14226 			 * This can happen if we have a stand-alone FIN or
14227 			 *  SYN.
14228 			 */
14229 			rsm->m = NULL;
14230 			rsm->orig_m_len = 0;
14231 			rsm->orig_t_space = 0;
14232 			rsm->soff = 0;
14233 		}
14234 #ifdef INVARIANTS
14235 		if ((insret = tqhash_insert(rack->r_ctl.tqh, rsm)) != 0) {
14236 			panic("Insert in tailq_hash fails ret:%d rack:%p rsm:%p",
14237 			      insret, rack, rsm);
14238 		}
14239 #else
14240 		(void)tqhash_insert(rack->r_ctl.tqh, rsm);
14241 #endif
14242 		TAILQ_INSERT_TAIL(&rack->r_ctl.rc_tmap, rsm, r_tnext);
14243 		rsm->r_in_tmap = 1;
14244 	} else {
14245 		/* We have a query mechanism, lets use it */
14246 		struct tcp_query_resp qr;
14247 		int i;
14248 		tcp_seq at;
14249 
14250 		at = tp->snd_una;
14251 		while (at != tp->snd_max) {
14252 			memset(&qr, 0, sizeof(qr));
14253 			qr.req = TCP_QUERY_SENDMAP;
14254 			qr.req_param = at;
14255 			if ((*tp->t_fb->tfb_chg_query)(tp, &qr) == 0)
14256 				break;
14257 			/* Move forward */
14258 			at = qr.sendmap_end;
14259 			/* Now lets build the entry for this one */
14260 			rsm = rack_alloc(rack);
14261 			if (rsm == NULL) {
14262 				uma_zfree(rack_pcb_zone, ptr);
14263 				return (ENOMEM);
14264 			}
14265 			memset(rsm, 0, sizeof(struct rack_sendmap));
14266 			/* Now configure the rsm and insert it */
14267 			rsm->r_dupack = qr.sendmap_dupacks;
14268 			rsm->r_start = qr.sendmap_start;
14269 			rsm->r_end = qr.sendmap_end;
14270 			if (qr.sendmap_fas)
14271 				rsm->r_fas = qr.sendmap_end;
14272 			else
14273 				rsm->r_fas = rsm->r_start - tp->snd_una;
14274 			/*
14275 			 * We have carefully aligned the bits
14276 			 * so that all we have to do is copy over
14277 			 * the bits with the mask.
14278 			 */
14279 			rsm->r_flags = qr.sendmap_flags & SNDMAP_MASK;
14280 			rsm->r_rtr_bytes = qr.sendmap_r_rtr_bytes;
14281 			rsm->r_rtr_cnt = qr.sendmap_send_cnt;
14282 			rsm->r_ack_arrival = qr.sendmap_ack_arrival;
14283 			for (i=0 ; i<rsm->r_rtr_cnt; i++)
14284 				rsm->r_tim_lastsent[i]	= qr.sendmap_time[i];
14285 			rsm->m = sbsndmbuf(&rack->rc_inp->inp_socket->so_snd,
14286 					   (rsm->r_start - tp->snd_una), &rsm->soff);
14287 			if (rsm->m) {
14288 				rsm->orig_m_len = rsm->m->m_len;
14289 				rsm->orig_t_space = M_TRAILINGROOM(rsm->m);
14290 			} else {
14291 				rsm->orig_m_len = 0;
14292 				rsm->orig_t_space = 0;
14293 			}
14294 #ifdef INVARIANTS
14295 			if ((insret = tqhash_insert(rack->r_ctl.tqh, rsm)) != 0) {
14296 				panic("Insert in tailq_hash fails ret:%d rack:%p rsm:%p",
14297 				      insret, rack, rsm);
14298 			}
14299 #else
14300 			(void)tqhash_insert(rack->r_ctl.tqh, rsm);
14301 #endif
14302 			if ((rsm->r_flags & RACK_ACKED) == 0)  {
14303 				TAILQ_FOREACH(ersm, &rack->r_ctl.rc_tmap, r_tnext) {
14304 					if (ersm->r_tim_lastsent[(ersm->r_rtr_cnt-1)] >
14305 					    rsm->r_tim_lastsent[(rsm->r_rtr_cnt-1)]) {
14306 						/*
14307 						 * If the existing ersm was sent at
14308 						 * a later time than the new one, then
14309 						 * the new one should appear ahead of this
14310 						 * ersm.
14311 						 */
14312 						rsm->r_in_tmap = 1;
14313 						TAILQ_INSERT_BEFORE(ersm, rsm, r_tnext);
14314 						break;
14315 					}
14316 				}
14317 				if (rsm->r_in_tmap == 0) {
14318 					/*
14319 					 * Not found so shove it on the tail.
14320 					 */
14321 					TAILQ_INSERT_TAIL(&rack->r_ctl.rc_tmap, rsm, r_tnext);
14322 					rsm->r_in_tmap = 1;
14323 				}
14324  			} else {
14325 				if ((rack->r_ctl.rc_sacklast == NULL) ||
14326 				    (SEQ_GT(rsm->r_end, rack->r_ctl.rc_sacklast->r_end))) {
14327 					rack->r_ctl.rc_sacklast = rsm;
14328 				}
14329 			}
14330 			rack_log_chg_info(tp, rack, 3,
14331 					  rsm->r_start,
14332 					  rsm->r_end,
14333 					  rsm->r_flags);
14334 		}
14335 	}
14336 	return (0);
14337 }
14338 
14339 
14340 static int32_t
14341 rack_init(struct tcpcb *tp, void **ptr)
14342 {
14343 	struct inpcb *inp = tptoinpcb(tp);
14344 	struct tcp_rack *rack = NULL;
14345 	uint32_t iwin, snt, us_cts;
14346 	size_t sz;
14347 	int err, no_query;
14348 
14349 	tcp_hpts_init(tp);
14350 
14351 	/*
14352 	 * First are we the initial or are we a switched stack?
14353 	 * If we are initing via tcp_newtcppcb the ptr passed
14354 	 * will be tp->t_fb_ptr. If its a stack switch that
14355 	 * has a previous stack we can query it will be a local
14356 	 * var that will in the end be set into t_fb_ptr.
14357 	 */
14358 	if (ptr == &tp->t_fb_ptr)
14359 		no_query = 1;
14360 	else
14361 		no_query = 0;
14362 	*ptr = uma_zalloc(rack_pcb_zone, M_NOWAIT);
14363 	if (*ptr == NULL) {
14364 		/*
14365 		 * We need to allocate memory but cant. The INP and INP_INFO
14366 		 * locks and they are recursive (happens during setup. So a
14367 		 * scheme to drop the locks fails :(
14368 		 *
14369 		 */
14370 		return(ENOMEM);
14371 	}
14372 	memset(*ptr, 0, sizeof(struct tcp_rack));
14373 	rack = (struct tcp_rack *)*ptr;
14374 	rack->r_ctl.tqh = malloc(sizeof(struct tailq_hash), M_TCPFSB, M_NOWAIT);
14375 	if (rack->r_ctl.tqh == NULL) {
14376 		uma_zfree(rack_pcb_zone, rack);
14377 		return(ENOMEM);
14378 	}
14379 	tqhash_init(rack->r_ctl.tqh);
14380 	TAILQ_INIT(&rack->r_ctl.rc_free);
14381 	TAILQ_INIT(&rack->r_ctl.rc_tmap);
14382 	rack->rc_tp = tp;
14383 	rack->rc_inp = inp;
14384 	/* Set the flag */
14385 	rack->r_is_v6 = (inp->inp_vflag & INP_IPV6) != 0;
14386 	/* Probably not needed but lets be sure */
14387 	rack_clear_rate_sample(rack);
14388 	/*
14389 	 * Save off the default values, socket options will poke
14390 	 * at these if pacing is not on or we have not yet
14391 	 * reached where pacing is on (gp_ready/fixed enabled).
14392 	 * When they get set into the CC module (when gp_ready
14393 	 * is enabled or we enable fixed) then we will set these
14394 	 * values into the CC and place in here the old values
14395 	 * so we have a restoral. Then we will set the flag
14396 	 * rc_pacing_cc_set. That way whenever we turn off pacing
14397 	 * or switch off this stack, we will know to go restore
14398 	 * the saved values.
14399 	 *
14400 	 * We specifically put into the beta the ecn value for pacing.
14401 	 */
14402 	rack->rc_new_rnd_needed = 1;
14403 	rack->r_ctl.rc_split_limit = V_tcp_map_split_limit;
14404 	/* We want abe like behavior as well */
14405 
14406 	rack->r_ctl.rc_reorder_fade = rack_reorder_fade;
14407 	rack->rc_allow_data_af_clo = rack_ignore_data_after_close;
14408 	rack->r_ctl.rc_tlp_threshold = rack_tlp_thresh;
14409 	if (rack_fill_cw_state)
14410 		rack->rc_pace_to_cwnd = 1;
14411 	if (rack_pacing_min_seg)
14412 		rack->r_ctl.rc_user_set_min_segs = rack_pacing_min_seg;
14413 	if (use_rack_rr)
14414 		rack->use_rack_rr = 1;
14415 	if (rack_dnd_default) {
14416 		rack->rc_pace_dnd = 1;
14417 	}
14418 	if (V_tcp_delack_enabled)
14419 		tp->t_delayed_ack = 1;
14420 	else
14421 		tp->t_delayed_ack = 0;
14422 #ifdef TCP_ACCOUNTING
14423 	if (rack_tcp_accounting) {
14424 		tp->t_flags2 |= TF2_TCP_ACCOUNTING;
14425 	}
14426 #endif
14427 	rack->r_ctl.pcm_i.cnt_alloc = RACK_DEFAULT_PCM_ARRAY;
14428 	sz = (sizeof(struct rack_pcm_stats) * rack->r_ctl.pcm_i.cnt_alloc);
14429 	rack->r_ctl.pcm_s = malloc(sz,M_TCPPCM, M_NOWAIT);
14430 	if (rack->r_ctl.pcm_s == NULL) {
14431 		rack->r_ctl.pcm_i.cnt_alloc = 0;
14432 	}
14433 	rack->r_ctl.rack_per_upper_bound_ss = (uint8_t)rack_per_upper_bound_ss;
14434 	rack->r_ctl.rack_per_upper_bound_ca = (uint8_t)rack_per_upper_bound_ca;
14435 	if (rack_enable_shared_cwnd)
14436 		rack->rack_enable_scwnd = 1;
14437 	rack->r_ctl.pace_len_divisor = rack_default_pacing_divisor;
14438 	rack->rc_user_set_max_segs = rack_hptsi_segments;
14439 	rack->r_ctl.max_reduction = rack_max_reduce;
14440 	rack->rc_force_max_seg = 0;
14441 	TAILQ_INIT(&rack->r_ctl.opt_list);
14442 	rack->r_ctl.rc_saved_beta = V_newreno_beta_ecn;
14443 	rack->r_ctl.rc_saved_beta_ecn = V_newreno_beta_ecn;
14444 	if (rack_hibeta_setting) {
14445 		rack->rack_hibeta = 1;
14446 		if ((rack_hibeta_setting >= 50) &&
14447 		    (rack_hibeta_setting <= 100)) {
14448 			rack->r_ctl.rc_saved_beta = rack_hibeta_setting;
14449 			rack->r_ctl.saved_hibeta = rack_hibeta_setting;
14450 		}
14451 	} else {
14452 		rack->r_ctl.saved_hibeta = 50;
14453 	}
14454 	/*
14455 	 * We initialize to all ones so we never match 0
14456 	 * just in case the client sends in 0, it hopefully
14457 	 * will never have all 1's in ms :-)
14458 	 */
14459 	rack->r_ctl.last_tm_mark = 0xffffffffffffffff;
14460 	rack->r_ctl.rc_reorder_shift = rack_reorder_thresh;
14461 	rack->r_ctl.rc_pkt_delay = rack_pkt_delay;
14462 	rack->r_ctl.rc_tlp_cwnd_reduce = rack_lower_cwnd_at_tlp;
14463 	rack->r_ctl.rc_lowest_us_rtt = 0xffffffff;
14464 	rack->r_ctl.rc_highest_us_rtt = 0;
14465 	rack->r_ctl.bw_rate_cap = rack_bw_rate_cap;
14466 	rack->pcm_enabled = rack_pcm_is_enabled;
14467 	if (rack_fillcw_bw_cap)
14468 		rack->r_ctl.fillcw_cap = rack_fillcw_bw_cap;
14469 	rack->r_ctl.timer_slop = TICKS_2_USEC(tcp_rexmit_slop);
14470 	if (rack_use_cmp_acks)
14471 		rack->r_use_cmp_ack = 1;
14472 	if (rack_disable_prr)
14473 		rack->rack_no_prr = 1;
14474 	if (rack_gp_no_rec_chg)
14475 		rack->rc_gp_no_rec_chg = 1;
14476 	if (rack_pace_every_seg && tcp_can_enable_pacing()) {
14477 		rack->r_ctl.pacing_method |= RACK_REG_PACING;
14478 		rack->rc_always_pace = 1;
14479 		if (rack->rack_hibeta)
14480 			rack_set_cc_pacing(rack);
14481 	} else
14482 		rack->rc_always_pace = 0;
14483 	if (rack_enable_mqueue_for_nonpaced || rack->r_use_cmp_ack)
14484 		rack->r_mbuf_queue = 1;
14485 	else
14486 		rack->r_mbuf_queue = 0;
14487 	rack_set_pace_segments(tp, rack, __LINE__, NULL);
14488 	if (rack_limits_scwnd)
14489 		rack->r_limit_scw = 1;
14490 	else
14491 		rack->r_limit_scw = 0;
14492 	rack_init_retransmit_value(rack, rack_rxt_controls);
14493 	rack->rc_labc = V_tcp_abc_l_var;
14494 	if (rack_honors_hpts_min_to)
14495 		rack->r_use_hpts_min = 1;
14496 	if (tp->snd_una != 0) {
14497 		rack->rc_sendvars_notset = 0;
14498 		/*
14499 		 * Make sure any TCP timers are not running.
14500 		 */
14501 		tcp_timer_stop(tp);
14502 	} else {
14503 		/*
14504 		 * Server side, we are called from the
14505 		 * syn-cache. This means none of the
14506 		 * snd_una/max are set yet so we have
14507 		 * to defer this until the first send.
14508 		 */
14509 		rack->rc_sendvars_notset = 1;
14510 	}
14511 
14512 	rack->r_ctl.rc_rate_sample_method = rack_rate_sample_method;
14513 	rack->rack_tlp_threshold_use = rack_tlp_threshold_use;
14514 	rack->r_ctl.rc_prr_sendalot = rack_send_a_lot_in_prr;
14515 	rack->r_ctl.rc_min_to = rack_min_to;
14516 	microuptime(&rack->r_ctl.act_rcv_time);
14517 	rack->r_ctl.rack_per_of_gp_ss = rack_per_of_gp_ss;
14518 	if (rack_hw_up_only)
14519 		rack->r_up_only = 1;
14520 	if (rack_do_dyn_mul) {
14521 		/* When dynamic adjustment is on CA needs to start at 100% */
14522 		rack->rc_gp_dyn_mul = 1;
14523 		if (rack_do_dyn_mul >= 100)
14524 			rack->r_ctl.rack_per_of_gp_ca = rack_do_dyn_mul;
14525 	} else
14526 		rack->r_ctl.rack_per_of_gp_ca = rack_per_of_gp_ca;
14527 	rack->r_ctl.rack_per_of_gp_rec = rack_per_of_gp_rec;
14528 	if (rack_timely_off) {
14529 		rack->rc_skip_timely = 1;
14530 	}
14531 	if (rack->rc_skip_timely) {
14532 		rack->r_ctl.rack_per_of_gp_rec = 90;
14533 		rack->r_ctl.rack_per_of_gp_ca = 100;
14534 		rack->r_ctl.rack_per_of_gp_ss = 250;
14535 	}
14536 	rack->r_ctl.rack_per_of_gp_probertt = rack_per_of_gp_probertt;
14537 	rack->r_ctl.rc_tlp_rxt_last_time = tcp_tv_to_msec(&rack->r_ctl.act_rcv_time);
14538 	rack->r_ctl.last_rcv_tstmp_for_rtt = tcp_tv_to_msec(&rack->r_ctl.act_rcv_time);
14539 
14540 	setup_time_filter_small(&rack->r_ctl.rc_gp_min_rtt, FILTER_TYPE_MIN,
14541 				rack_probertt_filter_life);
14542 	us_cts = tcp_tv_to_usec(&rack->r_ctl.act_rcv_time);
14543 	rack->r_ctl.rc_lower_rtt_us_cts = us_cts;
14544 	rack->r_ctl.rc_time_of_last_probertt = us_cts;
14545 	rack->r_ctl.rc_went_idle_time = us_cts;
14546 	rack->r_ctl.rc_time_probertt_starts = 0;
14547 
14548 	rack->r_ctl.gp_rnd_thresh = rack_rnd_cnt_req & 0xff;
14549 	if (rack_rnd_cnt_req  & 0x10000)
14550 		rack->r_ctl.gate_to_fs = 1;
14551 	rack->r_ctl.gp_gain_req = rack_gp_gain_req;
14552 	if ((rack_rnd_cnt_req & 0x100) > 0) {
14553 
14554 	}
14555 	if (rack_dsack_std_based & 0x1) {
14556 		/* Basically this means all rack timers are at least (srtt + 1/4 srtt) */
14557 		rack->rc_rack_tmr_std_based = 1;
14558 	}
14559 	if (rack_dsack_std_based & 0x2) {
14560 		/* Basically this means  rack timers are extended based on dsack by up to (2 * srtt) */
14561 		rack->rc_rack_use_dsack = 1;
14562 	}
14563 	/* We require at least one measurement, even if the sysctl is 0 */
14564 	if (rack_req_measurements)
14565 		rack->r_ctl.req_measurements = rack_req_measurements;
14566 	else
14567 		rack->r_ctl.req_measurements = 1;
14568 	if (rack_enable_hw_pacing)
14569 		rack->rack_hdw_pace_ena = 1;
14570 	if (rack_hw_rate_caps)
14571 		rack->r_rack_hw_rate_caps = 1;
14572 	if (rack_non_rxt_use_cr)
14573 		rack->rack_rec_nonrxt_use_cr = 1;
14574 	/* Lets setup the fsb block */
14575 	err = rack_init_fsb(tp, rack);
14576 	if (err) {
14577 		uma_zfree(rack_pcb_zone, *ptr);
14578 		*ptr = NULL;
14579 		return (err);
14580 	}
14581 	if (rack_do_hystart) {
14582 		tp->t_ccv.flags |= CCF_HYSTART_ALLOWED;
14583 		if (rack_do_hystart > 1)
14584 			tp->t_ccv.flags |= CCF_HYSTART_CAN_SH_CWND;
14585 		if (rack_do_hystart > 2)
14586 			tp->t_ccv.flags |= CCF_HYSTART_CONS_SSTH;
14587 	}
14588 	/* Log what we will do with queries */
14589 	rack_log_chg_info(tp, rack, 7,
14590 			  no_query, 0, 0);
14591 	if (rack_def_profile)
14592 		rack_set_profile(rack, rack_def_profile);
14593 	/* Cancel the GP measurement in progress */
14594 	tp->t_flags &= ~TF_GPUTINPROG;
14595 	if ((tp->t_state != TCPS_CLOSED) &&
14596 	    (tp->t_state != TCPS_TIME_WAIT)) {
14597 		/*
14598 		 * We are already open, we may
14599 		 * need to adjust a few things.
14600 		 */
14601 		if (SEQ_GT(tp->snd_max, tp->iss))
14602 			snt = tp->snd_max - tp->iss;
14603 		else
14604 			snt = 0;
14605 		iwin = rc_init_window(rack);
14606 		if ((snt < iwin) &&
14607 		    (no_query == 1)) {
14608 			/* We are not past the initial window
14609 			 * on the first init (i.e. a stack switch
14610 			 * has not yet occured) so we need to make
14611 			 * sure cwnd and ssthresh is correct.
14612 			 */
14613 			if (tp->snd_cwnd < iwin)
14614 				tp->snd_cwnd = iwin;
14615 			/*
14616 			 * If we are within the initial window
14617 			 * we want ssthresh to be unlimited. Setting
14618 			 * it to the rwnd (which the default stack does
14619 			 * and older racks) is not really a good idea
14620 			 * since we want to be in SS and grow both the
14621 			 * cwnd and the rwnd (via dynamic rwnd growth). If
14622 			 * we set it to the rwnd then as the peer grows its
14623 			 * rwnd we will be stuck in CA and never hit SS.
14624 			 *
14625 			 * Its far better to raise it up high (this takes the
14626 			 * risk that there as been a loss already, probably
14627 			 * we should have an indicator in all stacks of loss
14628 			 * but we don't), but considering the normal use this
14629 			 * is a risk worth taking. The consequences of not
14630 			 * hitting SS are far worse than going one more time
14631 			 * into it early on (before we have sent even a IW).
14632 			 * It is highly unlikely that we will have had a loss
14633 			 * before getting the IW out.
14634 			 */
14635 			tp->snd_ssthresh = 0xffffffff;
14636 		}
14637 		/*
14638 		 * Any init based on sequence numbers
14639 		 * should be done in the deferred init path
14640 		 * since we can be CLOSED and not have them
14641 		 * inited when rack_init() is called. We
14642 		 * are not closed so lets call it.
14643 		 */
14644 		rack_deferred_init(tp, rack);
14645 	}
14646 	if ((tp->t_state != TCPS_CLOSED) &&
14647 	    (tp->t_state != TCPS_TIME_WAIT) &&
14648 	    (no_query == 0) &&
14649 	    (tp->snd_una != tp->snd_max))  {
14650 		err = rack_init_outstanding(tp, rack, us_cts, *ptr);
14651 		if (err) {
14652 			*ptr = NULL;
14653 			return(err);
14654 		}
14655 	}
14656 	rack_stop_all_timers(tp, rack);
14657 	/* Setup all the t_flags2 */
14658 	if  (rack->r_mbuf_queue || rack->rc_always_pace || rack->r_use_cmp_ack)
14659 		tp->t_flags2 |= TF2_SUPPORTS_MBUFQ;
14660 	else
14661 		tp->t_flags2 &= ~TF2_SUPPORTS_MBUFQ;
14662 	if (rack->r_use_cmp_ack && TCPS_HAVEESTABLISHED(tp->t_state))
14663 		tp->t_flags2 |= TF2_MBUF_ACKCMP;
14664 	/*
14665 	 * Timers in Rack are kept in microseconds so lets
14666 	 * convert any initial incoming variables
14667 	 * from ticks into usecs. Note that we
14668 	 * also change the values of t_srtt and t_rttvar, if
14669 	 * they are non-zero. They are kept with a 5
14670 	 * bit decimal so we have to carefully convert
14671 	 * these to get the full precision.
14672 	 */
14673 	rack_convert_rtts(tp);
14674 	rack_log_hystart_event(rack, rack->r_ctl.roundends, 20);
14675 	if ((tptoinpcb(tp)->inp_flags & INP_DROPPED) == 0) {
14676 		/* We do not start any timers on DROPPED connections */
14677 		if (tp->t_fb->tfb_chg_query == NULL) {
14678 			rack_start_hpts_timer(rack, tp, tcp_get_usecs(NULL), 0, 0, 0);
14679 		} else {
14680 			struct tcp_query_resp qr;
14681 			int ret;
14682 
14683 			memset(&qr, 0, sizeof(qr));
14684 
14685 			/* Get the misc time stamps and such for rack */
14686 			qr.req = TCP_QUERY_RACK_TIMES;
14687 			ret = (*tp->t_fb->tfb_chg_query)(tp, &qr);
14688 			if (ret == 1) {
14689 				rack->r_ctl.rc_reorder_ts = qr.rack_reorder_ts;
14690 				rack->r_ctl.num_dsack  = qr.rack_num_dsacks;
14691 				rack->r_ctl.rc_tlp_rxt_last_time = qr.rack_rxt_last_time;
14692 				rack->r_ctl.rc_rack_min_rtt = qr.rack_min_rtt;
14693 				rack->rc_rack_rtt = qr.rack_rtt;
14694 				rack->r_ctl.rc_rack_tmit_time = qr.rack_tmit_time;
14695 				rack->r_ctl.rc_sacked = qr.rack_sacked;
14696 				rack->r_ctl.rc_holes_rxt = qr.rack_holes_rxt;
14697 				rack->r_ctl.rc_prr_delivered = qr.rack_prr_delivered;
14698 				rack->r_ctl.rc_prr_recovery_fs = qr.rack_prr_recovery_fs;
14699 				rack->r_ctl.rc_prr_sndcnt = qr.rack_prr_sndcnt;
14700 				rack->r_ctl.rc_prr_out = qr.rack_prr_out;
14701 				if (qr.rack_tlp_out) {
14702 					rack->rc_tlp_in_progress = 1;
14703 					rack->r_ctl.rc_tlp_cnt_out = qr.rack_tlp_cnt_out;
14704 				} else {
14705 					rack->rc_tlp_in_progress = 0;
14706 					rack->r_ctl.rc_tlp_cnt_out = 0;
14707 				}
14708 				if (qr.rack_srtt_measured)
14709 					rack->rc_srtt_measure_made = 1;
14710 				if (qr.rack_in_persist == 1) {
14711 					rack->r_ctl.rc_went_idle_time = qr.rack_time_went_idle;
14712 #ifdef NETFLIX_SHARED_CWND
14713 					if (rack->r_ctl.rc_scw) {
14714 						tcp_shared_cwnd_idle(rack->r_ctl.rc_scw, rack->r_ctl.rc_scw_index);
14715 						rack->rack_scwnd_is_idle = 1;
14716 					}
14717 #endif
14718 					rack->r_ctl.persist_lost_ends = 0;
14719 					rack->probe_not_answered = 0;
14720 					rack->forced_ack = 0;
14721 					tp->t_rxtshift = 0;
14722 					rack->rc_in_persist = 1;
14723 					RACK_TCPT_RANGESET(tp->t_rxtcur, RACK_REXMTVAL(tp),
14724 							   rack_rto_min, rack_rto_max, rack->r_ctl.timer_slop);
14725 				}
14726 				if (qr.rack_wanted_output)
14727 					rack->r_wanted_output = 1;
14728 				rack_log_chg_info(tp, rack, 6,
14729 						  qr.rack_min_rtt,
14730 						  qr.rack_rtt,
14731 						  qr.rack_reorder_ts);
14732 			}
14733 			/* Get the old stack timers */
14734 			qr.req_param = 0;
14735 			qr.req = TCP_QUERY_TIMERS_UP;
14736 			ret = (*tp->t_fb->tfb_chg_query)(tp, &qr);
14737 			if (ret) {
14738 				/*
14739 				 * non-zero return means we have a timer('s)
14740 				 * to start. Zero means no timer (no keepalive
14741 				 * I suppose).
14742 				 */
14743 				uint32_t tov = 0;
14744 
14745 				rack->r_ctl.rc_hpts_flags = qr.timer_hpts_flags;
14746 				if (qr.timer_hpts_flags & PACE_PKT_OUTPUT) {
14747 					rack->r_ctl.rc_last_output_to = qr.timer_pacing_to;
14748 					if (TSTMP_GT(qr.timer_pacing_to, us_cts))
14749 						tov = qr.timer_pacing_to - us_cts;
14750 					else
14751 						tov = HPTS_USECS_PER_SLOT;
14752 				}
14753 				if (qr.timer_hpts_flags & PACE_TMR_MASK) {
14754 					rack->r_ctl.rc_timer_exp = qr.timer_timer_exp;
14755 					if (tov == 0) {
14756 						if (TSTMP_GT(qr.timer_timer_exp, us_cts))
14757 							tov = qr.timer_timer_exp - us_cts;
14758 						else
14759 							tov = HPTS_USECS_PER_SLOT;
14760 					}
14761 				}
14762 				rack_log_chg_info(tp, rack, 4,
14763 						  rack->r_ctl.rc_hpts_flags,
14764 						  rack->r_ctl.rc_last_output_to,
14765 						  rack->r_ctl.rc_timer_exp);
14766 				if (tov) {
14767 					struct hpts_diag diag;
14768 
14769 					tcp_hpts_insert(tp, tov, &diag);
14770 					rack_log_hpts_diag(rack, us_cts, &diag, &rack->r_ctl.act_rcv_time);
14771 				}
14772 			}
14773 		}
14774 		rack_log_rtt_shrinks(rack,  us_cts,  tp->t_rxtcur,
14775 				     __LINE__, RACK_RTTS_INIT);
14776 	}
14777 	return (0);
14778 }
14779 
14780 static int
14781 rack_handoff_ok(struct tcpcb *tp)
14782 {
14783 	if ((tp->t_state == TCPS_CLOSED) ||
14784 	    (tp->t_state == TCPS_LISTEN)) {
14785 		/* Sure no problem though it may not stick */
14786 		return (0);
14787 	}
14788 	if ((tp->t_state == TCPS_SYN_SENT) ||
14789 	    (tp->t_state == TCPS_SYN_RECEIVED)) {
14790 		/*
14791 		 * We really don't know if you support sack,
14792 		 * you have to get to ESTAB or beyond to tell.
14793 		 */
14794 		return (EAGAIN);
14795 	}
14796 	if ((tp->t_flags & TF_SENTFIN) && ((tp->snd_max - tp->snd_una) > 1)) {
14797 		/*
14798 		 * Rack will only send a FIN after all data is acknowledged.
14799 		 * So in this case we have more data outstanding. We can't
14800 		 * switch stacks until either all data and only the FIN
14801 		 * is left (in which case rack_init() now knows how
14802 		 * to deal with that) <or> all is acknowledged and we
14803 		 * are only left with incoming data, though why you
14804 		 * would want to switch to rack after all data is acknowledged
14805 		 * I have no idea (rrs)!
14806 		 */
14807 		return (EAGAIN);
14808 	}
14809 	if ((tp->t_flags & TF_SACK_PERMIT) || rack_sack_not_required){
14810 		return (0);
14811 	}
14812 	/*
14813 	 * If we reach here we don't do SACK on this connection so we can
14814 	 * never do rack.
14815 	 */
14816 	return (EINVAL);
14817 }
14818 
14819 static void
14820 rack_fini(struct tcpcb *tp, int32_t tcb_is_purged)
14821 {
14822 
14823 	if (tp->t_fb_ptr) {
14824 		uint32_t cnt_free = 0;
14825 		struct tcp_rack *rack;
14826 		struct rack_sendmap *rsm;
14827 
14828 		tcp_handle_orphaned_packets(tp);
14829 		tp->t_flags &= ~TF_FORCEDATA;
14830 		rack = (struct tcp_rack *)tp->t_fb_ptr;
14831 		rack_log_pacing_delay_calc(rack,
14832 					   0,
14833 					   0,
14834 					   0,
14835 					   rack_get_gp_est(rack), /* delRate */
14836 					   rack_get_lt_bw(rack), /* rttProp */
14837 					   20, __LINE__, NULL, 0);
14838 #ifdef NETFLIX_SHARED_CWND
14839 		if (rack->r_ctl.rc_scw) {
14840 			uint32_t limit;
14841 
14842 			if (rack->r_limit_scw)
14843 				limit = max(1, rack->r_ctl.rc_lowest_us_rtt);
14844 			else
14845 				limit = 0;
14846 			tcp_shared_cwnd_free_full(tp, rack->r_ctl.rc_scw,
14847 						  rack->r_ctl.rc_scw_index,
14848 						  limit);
14849 			rack->r_ctl.rc_scw = NULL;
14850 		}
14851 #endif
14852 		if (rack->r_ctl.fsb.tcp_ip_hdr) {
14853 			free(rack->r_ctl.fsb.tcp_ip_hdr, M_TCPFSB);
14854 			rack->r_ctl.fsb.tcp_ip_hdr = NULL;
14855 			rack->r_ctl.fsb.th = NULL;
14856 		}
14857 		if (rack->rc_always_pace == 1) {
14858 			rack_remove_pacing(rack);
14859 		}
14860 		/* Clean up any options if they were not applied */
14861 		while (!TAILQ_EMPTY(&rack->r_ctl.opt_list)) {
14862 			struct deferred_opt_list *dol;
14863 
14864 			dol = TAILQ_FIRST(&rack->r_ctl.opt_list);
14865 			TAILQ_REMOVE(&rack->r_ctl.opt_list, dol, next);
14866 			free(dol, M_TCPDO);
14867 		}
14868 		/* rack does not use force data but other stacks may clear it */
14869 		if (rack->r_ctl.crte != NULL) {
14870 			tcp_rel_pacing_rate(rack->r_ctl.crte, tp);
14871 			rack->rack_hdrw_pacing = 0;
14872 			rack->r_ctl.crte = NULL;
14873 		}
14874 #ifdef TCP_BLACKBOX
14875 		tcp_log_flowend(tp);
14876 #endif
14877 		/*
14878 		 * Lets take a different approach to purging just
14879 		 * get each one and free it like a cum-ack would and
14880 		 * not use a foreach loop.
14881 		 */
14882 		rsm = tqhash_min(rack->r_ctl.tqh);
14883 		while (rsm) {
14884 			tqhash_remove(rack->r_ctl.tqh, rsm, REMOVE_TYPE_CUMACK);
14885 			rack->r_ctl.rc_num_maps_alloced--;
14886 			uma_zfree(rack_zone, rsm);
14887 			rsm = tqhash_min(rack->r_ctl.tqh);
14888 		}
14889 		rsm = TAILQ_FIRST(&rack->r_ctl.rc_free);
14890 		while (rsm) {
14891 			TAILQ_REMOVE(&rack->r_ctl.rc_free, rsm, r_tnext);
14892 			rack->r_ctl.rc_num_maps_alloced--;
14893 			rack->rc_free_cnt--;
14894 			cnt_free++;
14895 			uma_zfree(rack_zone, rsm);
14896 			rsm = TAILQ_FIRST(&rack->r_ctl.rc_free);
14897 		}
14898 		if (rack->r_ctl.pcm_s != NULL) {
14899 			free(rack->r_ctl.pcm_s, M_TCPPCM);
14900 			rack->r_ctl.pcm_s = NULL;
14901 			rack->r_ctl.pcm_i.cnt_alloc = 0;
14902 			rack->r_ctl.pcm_i.cnt = 0;
14903 		}
14904 		if ((rack->r_ctl.rc_num_maps_alloced > 0) &&
14905 		    (tcp_bblogging_on(tp))) {
14906 			union tcp_log_stackspecific log;
14907 			struct timeval tv;
14908 
14909 			memset(&log, 0, sizeof(log));
14910 			log.u_bbr.flex8 = 10;
14911 			log.u_bbr.flex1 = rack->r_ctl.rc_num_maps_alloced;
14912 			log.u_bbr.flex2 = rack->rc_free_cnt;
14913 			log.u_bbr.flex3 = cnt_free;
14914 			log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
14915 			rsm = tqhash_min(rack->r_ctl.tqh);
14916 			log.u_bbr.delRate = (uintptr_t)rsm;
14917 			rsm = TAILQ_FIRST(&rack->r_ctl.rc_free);
14918 			log.u_bbr.cur_del_rate = (uintptr_t)rsm;
14919 			log.u_bbr.timeStamp = tcp_get_usecs(&tv);
14920 			log.u_bbr.pkt_epoch = __LINE__;
14921 			(void)tcp_log_event(tp, NULL, NULL, NULL, TCP_LOG_OUT, ERRNO_UNK,
14922 					     0, &log, false, NULL, NULL, 0, &tv);
14923 		}
14924 		KASSERT((rack->r_ctl.rc_num_maps_alloced == 0),
14925 			("rack:%p num_aloc:%u after freeing all?",
14926 			 rack,
14927 			 rack->r_ctl.rc_num_maps_alloced));
14928 		rack->rc_free_cnt = 0;
14929 		free(rack->r_ctl.tqh, M_TCPFSB);
14930 		rack->r_ctl.tqh = NULL;
14931 		uma_zfree(rack_pcb_zone, tp->t_fb_ptr);
14932 		tp->t_fb_ptr = NULL;
14933 	}
14934 	/* Make sure snd_nxt is correctly set */
14935 	tp->snd_nxt = tp->snd_max;
14936 }
14937 
14938 static void
14939 rack_set_state(struct tcpcb *tp, struct tcp_rack *rack)
14940 {
14941 	if ((rack->r_state == TCPS_CLOSED) && (tp->t_state != TCPS_CLOSED)) {
14942 		rack->r_is_v6 = (tptoinpcb(tp)->inp_vflag & INP_IPV6) != 0;
14943 	}
14944 	switch (tp->t_state) {
14945 	case TCPS_SYN_SENT:
14946 		rack->r_state = TCPS_SYN_SENT;
14947 		rack->r_substate = rack_do_syn_sent;
14948 		break;
14949 	case TCPS_SYN_RECEIVED:
14950 		rack->r_state = TCPS_SYN_RECEIVED;
14951 		rack->r_substate = rack_do_syn_recv;
14952 		break;
14953 	case TCPS_ESTABLISHED:
14954 		rack_set_pace_segments(tp, rack, __LINE__, NULL);
14955 		rack->r_state = TCPS_ESTABLISHED;
14956 		rack->r_substate = rack_do_established;
14957 		break;
14958 	case TCPS_CLOSE_WAIT:
14959 		rack->r_state = TCPS_CLOSE_WAIT;
14960 		rack->r_substate = rack_do_close_wait;
14961 		break;
14962 	case TCPS_FIN_WAIT_1:
14963 		rack_set_pace_segments(tp, rack, __LINE__, NULL);
14964 		rack->r_state = TCPS_FIN_WAIT_1;
14965 		rack->r_substate = rack_do_fin_wait_1;
14966 		break;
14967 	case TCPS_CLOSING:
14968 		rack_set_pace_segments(tp, rack, __LINE__, NULL);
14969 		rack->r_state = TCPS_CLOSING;
14970 		rack->r_substate = rack_do_closing;
14971 		break;
14972 	case TCPS_LAST_ACK:
14973 		rack_set_pace_segments(tp, rack, __LINE__, NULL);
14974 		rack->r_state = TCPS_LAST_ACK;
14975 		rack->r_substate = rack_do_lastack;
14976 		break;
14977 	case TCPS_FIN_WAIT_2:
14978 		rack->r_state = TCPS_FIN_WAIT_2;
14979 		rack->r_substate = rack_do_fin_wait_2;
14980 		break;
14981 	case TCPS_LISTEN:
14982 	case TCPS_CLOSED:
14983 	case TCPS_TIME_WAIT:
14984 	default:
14985 		break;
14986 	};
14987 	if (rack->r_use_cmp_ack && TCPS_HAVEESTABLISHED(tp->t_state))
14988 		rack->rc_tp->t_flags2 |= TF2_MBUF_ACKCMP;
14989 
14990 }
14991 
14992 static void
14993 rack_timer_audit(struct tcpcb *tp, struct tcp_rack *rack, struct sockbuf *sb)
14994 {
14995 	/*
14996 	 * We received an ack, and then did not
14997 	 * call send or were bounced out due to the
14998 	 * hpts was running. Now a timer is up as well, is
14999 	 * it the right timer?
15000 	 */
15001 	struct rack_sendmap *rsm;
15002 	int tmr_up;
15003 
15004 	tmr_up = rack->r_ctl.rc_hpts_flags & PACE_TMR_MASK;
15005 	if (tcp_in_hpts(rack->rc_tp) == 0) {
15006 		/*
15007 		 * Ok we probably need some timer up, but no
15008 		 * matter what the mask we are not in hpts. We
15009 		 * may have received an old ack and thus did nothing.
15010 		 */
15011 		rack_timer_cancel(tp, rack, rack->r_ctl.rc_rcvtime, __LINE__);
15012 		rack_start_hpts_timer(rack, tp, tcp_get_usecs(NULL), 0, 0, 0);
15013 		return;
15014 	}
15015 	if (rack->rc_in_persist && (tmr_up == PACE_TMR_PERSIT))
15016 		return;
15017 	rsm = TAILQ_FIRST(&rack->r_ctl.rc_tmap);
15018 	if (((rsm == NULL) || (tp->t_state < TCPS_ESTABLISHED)) &&
15019 	    (tmr_up == PACE_TMR_RXT)) {
15020 		/* Should be an RXT */
15021 		return;
15022 	}
15023 	if (rsm == NULL) {
15024 		/* Nothing outstanding? */
15025 		if (tp->t_flags & TF_DELACK) {
15026 			if (tmr_up == PACE_TMR_DELACK)
15027 				/* We are supposed to have delayed ack up and we do */
15028 				return;
15029 		} else if (((V_tcp_always_keepalive ||
15030 			     rack->rc_inp->inp_socket->so_options & SO_KEEPALIVE) &&
15031 			    (tp->t_state <= TCPS_CLOSING)) &&
15032 			   (tmr_up == PACE_TMR_KEEP) &&
15033 			   (tp->snd_max == tp->snd_una)) {
15034 			/* We should have keep alive up and we do */
15035 			return;
15036 		}
15037 	}
15038 	if (SEQ_GT(tp->snd_max, tp->snd_una) &&
15039 		   ((tmr_up == PACE_TMR_TLP) ||
15040 		    (tmr_up == PACE_TMR_RACK) ||
15041 		    (tmr_up == PACE_TMR_RXT))) {
15042 		/*
15043 		 * Either a Rack, TLP or RXT is fine if  we
15044 		 * have outstanding data.
15045 		 */
15046 		return;
15047 	} else if (tmr_up == PACE_TMR_DELACK) {
15048 		/*
15049 		 * If the delayed ack was going to go off
15050 		 * before the rtx/tlp/rack timer were going to
15051 		 * expire, then that would be the timer in control.
15052 		 * Note we don't check the time here trusting the
15053 		 * code is correct.
15054 		 */
15055 		return;
15056 	}
15057 	/*
15058 	 * Ok the timer originally started is not what we want now.
15059 	 * We will force the hpts to be stopped if any, and restart
15060 	 * with the slot set to what was in the saved slot.
15061 	 */
15062 	if (tcp_in_hpts(rack->rc_tp)) {
15063 		if (rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT) {
15064 			uint32_t us_cts;
15065 
15066 			us_cts = tcp_get_usecs(NULL);
15067 			if (TSTMP_GT(rack->r_ctl.rc_last_output_to, us_cts)) {
15068 				rack->r_early = 1;
15069 				rack->r_ctl.rc_agg_early += (rack->r_ctl.rc_last_output_to - us_cts);
15070 			}
15071 			rack->r_ctl.rc_hpts_flags &= ~PACE_PKT_OUTPUT;
15072 		}
15073 		tcp_hpts_remove(rack->rc_tp);
15074 	}
15075 	rack_timer_cancel(tp, rack, rack->r_ctl.rc_rcvtime, __LINE__);
15076 	rack_start_hpts_timer(rack, tp, tcp_get_usecs(NULL), 0, 0, 0);
15077 }
15078 
15079 
15080 static void
15081 rack_do_win_updates(struct tcpcb *tp, struct tcp_rack *rack, uint32_t tiwin, uint32_t seq, uint32_t ack, uint32_t cts)
15082 {
15083 	if ((SEQ_LT(tp->snd_wl1, seq) ||
15084 	    (tp->snd_wl1 == seq && (SEQ_LT(tp->snd_wl2, ack) ||
15085 	    (tp->snd_wl2 == ack && tiwin > tp->snd_wnd))))) {
15086 		/* keep track of pure window updates */
15087 		if ((tp->snd_wl2 == ack) && (tiwin > tp->snd_wnd))
15088 			KMOD_TCPSTAT_INC(tcps_rcvwinupd);
15089 		tp->snd_wnd = tiwin;
15090 		rack_validate_fo_sendwin_up(tp, rack);
15091 		tp->snd_wl1 = seq;
15092 		tp->snd_wl2 = ack;
15093 		if (tp->snd_wnd > tp->max_sndwnd)
15094 			tp->max_sndwnd = tp->snd_wnd;
15095 	    rack->r_wanted_output = 1;
15096 	} else if ((tp->snd_wl2 == ack) && (tiwin < tp->snd_wnd)) {
15097 		tp->snd_wnd = tiwin;
15098 		rack_validate_fo_sendwin_up(tp, rack);
15099 		tp->snd_wl1 = seq;
15100 		tp->snd_wl2 = ack;
15101 	} else {
15102 		/* Not a valid win update */
15103 		return;
15104 	}
15105 	if (tp->snd_wnd > tp->max_sndwnd)
15106 		tp->max_sndwnd = tp->snd_wnd;
15107 	/* Do we exit persists? */
15108 	if ((rack->rc_in_persist != 0) &&
15109 	    (tp->snd_wnd >= min((rack->r_ctl.rc_high_rwnd/2),
15110 				rack->r_ctl.rc_pace_min_segs))) {
15111 		rack_exit_persist(tp, rack, cts);
15112 	}
15113 	/* Do we enter persists? */
15114 	if ((rack->rc_in_persist == 0) &&
15115 	    (tp->snd_wnd < min((rack->r_ctl.rc_high_rwnd/2), rack->r_ctl.rc_pace_min_segs)) &&
15116 	    TCPS_HAVEESTABLISHED(tp->t_state) &&
15117 	    ((tp->snd_max == tp->snd_una) || rack->rc_has_collapsed) &&
15118 	    sbavail(&tptosocket(tp)->so_snd) &&
15119 	    (sbavail(&tptosocket(tp)->so_snd) > tp->snd_wnd)) {
15120 		/*
15121 		 * Here the rwnd is less than
15122 		 * the pacing size, we are established,
15123 		 * nothing is outstanding, and there is
15124 		 * data to send. Enter persists.
15125 		 */
15126 		rack_enter_persist(tp, rack, rack->r_ctl.rc_rcvtime, ack);
15127 	}
15128 }
15129 
15130 static void
15131 rack_log_input_packet(struct tcpcb *tp, struct tcp_rack *rack, struct tcp_ackent *ae, int ackval, uint32_t high_seq)
15132 {
15133 
15134 	if (tcp_bblogging_on(rack->rc_tp)) {
15135 		struct inpcb *inp = tptoinpcb(tp);
15136 		union tcp_log_stackspecific log;
15137 		struct timeval ltv;
15138 		char tcp_hdr_buf[60];
15139 		struct tcphdr *th;
15140 		struct timespec ts;
15141 		uint32_t orig_snd_una;
15142 		uint8_t xx = 0;
15143 
15144 #ifdef TCP_REQUEST_TRK
15145 		struct tcp_sendfile_track *tcp_req;
15146 
15147 		if (SEQ_GT(ae->ack, tp->snd_una)) {
15148 			tcp_req = tcp_req_find_req_for_seq(tp, (ae->ack-1));
15149 		} else {
15150 			tcp_req = tcp_req_find_req_for_seq(tp, ae->ack);
15151 		}
15152 #endif
15153 		memset(&log, 0, sizeof(log));
15154 		log.u_bbr.inhpts = tcp_in_hpts(rack->rc_tp);
15155 		if (rack->rack_no_prr == 0)
15156 			log.u_bbr.flex1 = rack->r_ctl.rc_prr_sndcnt;
15157 		else
15158 			log.u_bbr.flex1 = 0;
15159 		log.u_bbr.use_lt_bw = rack->r_ent_rec_ns;
15160 		log.u_bbr.use_lt_bw <<= 1;
15161 		log.u_bbr.use_lt_bw |= rack->r_might_revert;
15162 		log.u_bbr.flex2 = rack->r_ctl.rc_num_maps_alloced;
15163 		log.u_bbr.bbr_state = rack->rc_free_cnt;
15164 		log.u_bbr.inflight = ctf_flight_size(tp, rack->r_ctl.rc_sacked);
15165 		log.u_bbr.pkts_out = tp->t_maxseg;
15166 		log.u_bbr.flex4 = rack->r_ctl.rc_hpts_flags;
15167 		log.u_bbr.flex7 = 1;
15168 		log.u_bbr.lost = ae->flags;
15169 		log.u_bbr.cwnd_gain = ackval;
15170 		log.u_bbr.pacing_gain = 0x2;
15171 		if (ae->flags & TSTMP_HDWR) {
15172 			/* Record the hardware timestamp if present */
15173 			log.u_bbr.flex3 = M_TSTMP;
15174 			ts.tv_sec = ae->timestamp / 1000000000;
15175 			ts.tv_nsec = ae->timestamp % 1000000000;
15176 			ltv.tv_sec = ts.tv_sec;
15177 			ltv.tv_usec = ts.tv_nsec / 1000;
15178 			log.u_bbr.lt_epoch = tcp_tv_to_usec(&ltv);
15179 		} else if (ae->flags & TSTMP_LRO) {
15180 			/* Record the LRO the arrival timestamp */
15181 			log.u_bbr.flex3 = M_TSTMP_LRO;
15182 			ts.tv_sec = ae->timestamp / 1000000000;
15183 			ts.tv_nsec = ae->timestamp % 1000000000;
15184 			ltv.tv_sec = ts.tv_sec;
15185 			ltv.tv_usec = ts.tv_nsec / 1000;
15186 			log.u_bbr.flex5 = tcp_tv_to_usec(&ltv);
15187 		}
15188 		log.u_bbr.timeStamp = tcp_get_usecs(&ltv);
15189 		/* Log the rcv time */
15190 		log.u_bbr.delRate = ae->timestamp;
15191 #ifdef TCP_REQUEST_TRK
15192 		log.u_bbr.applimited = tp->t_tcpreq_closed;
15193 		log.u_bbr.applimited <<= 8;
15194 		log.u_bbr.applimited |= tp->t_tcpreq_open;
15195 		log.u_bbr.applimited <<= 8;
15196 		log.u_bbr.applimited |= tp->t_tcpreq_req;
15197 		if (tcp_req) {
15198 			/* Copy out any client req info */
15199 			/* seconds */
15200 			log.u_bbr.pkt_epoch = (tcp_req->localtime / HPTS_USEC_IN_SEC);
15201 			/* useconds */
15202 			log.u_bbr.delivered = (tcp_req->localtime % HPTS_USEC_IN_SEC);
15203 			log.u_bbr.rttProp = tcp_req->timestamp;
15204 			log.u_bbr.cur_del_rate = tcp_req->start;
15205 			if (tcp_req->flags & TCP_TRK_TRACK_FLG_OPEN) {
15206 				log.u_bbr.flex8 |= 1;
15207 			} else {
15208 				log.u_bbr.flex8 |= 2;
15209 				log.u_bbr.bw_inuse = tcp_req->end;
15210 			}
15211 			log.u_bbr.flex6 = tcp_req->start_seq;
15212 			if (tcp_req->flags & TCP_TRK_TRACK_FLG_COMP) {
15213 				log.u_bbr.flex8 |= 4;
15214 				log.u_bbr.epoch = tcp_req->end_seq;
15215 			}
15216 		}
15217 #endif
15218 		memset(tcp_hdr_buf, 0, sizeof(tcp_hdr_buf));
15219 		th = (struct tcphdr *)tcp_hdr_buf;
15220 		th->th_seq = ae->seq;
15221 		th->th_ack = ae->ack;
15222 		th->th_win = ae->win;
15223 		/* Now fill in the ports */
15224 		th->th_sport = inp->inp_fport;
15225 		th->th_dport = inp->inp_lport;
15226 		tcp_set_flags(th, ae->flags);
15227 		/* Now do we have a timestamp option? */
15228 		if (ae->flags & HAS_TSTMP) {
15229 			u_char *cp;
15230 			uint32_t val;
15231 
15232 			th->th_off = ((sizeof(struct tcphdr) + TCPOLEN_TSTAMP_APPA) >> 2);
15233 			cp = (u_char *)(th + 1);
15234 			*cp = TCPOPT_NOP;
15235 			cp++;
15236 			*cp = TCPOPT_NOP;
15237 			cp++;
15238 			*cp = TCPOPT_TIMESTAMP;
15239 			cp++;
15240 			*cp = TCPOLEN_TIMESTAMP;
15241 			cp++;
15242 			val = htonl(ae->ts_value);
15243 			bcopy((char *)&val,
15244 			      (char *)cp, sizeof(uint32_t));
15245 			val = htonl(ae->ts_echo);
15246 			bcopy((char *)&val,
15247 			      (char *)(cp + 4), sizeof(uint32_t));
15248 		} else
15249 			th->th_off = (sizeof(struct tcphdr) >> 2);
15250 
15251 		/*
15252 		 * For sane logging we need to play a little trick.
15253 		 * If the ack were fully processed we would have moved
15254 		 * snd_una to high_seq, but since compressed acks are
15255 		 * processed in two phases, at this point (logging) snd_una
15256 		 * won't be advanced. So we would see multiple acks showing
15257 		 * the advancement. We can prevent that by "pretending" that
15258 		 * snd_una was advanced and then un-advancing it so that the
15259 		 * logging code has the right value for tlb_snd_una.
15260 		 */
15261 		if (tp->snd_una != high_seq) {
15262 			orig_snd_una = tp->snd_una;
15263 			tp->snd_una = high_seq;
15264 			xx = 1;
15265 		} else
15266 			xx = 0;
15267 		TCP_LOG_EVENTP(tp, th,
15268 			       &tptosocket(tp)->so_rcv,
15269 			       &tptosocket(tp)->so_snd, TCP_LOG_IN, 0,
15270 			       0, &log, true, &ltv);
15271 		if (xx) {
15272 			tp->snd_una = orig_snd_una;
15273 		}
15274 	}
15275 
15276 }
15277 
15278 static void
15279 rack_handle_probe_response(struct tcp_rack *rack, uint32_t tiwin, uint32_t us_cts)
15280 {
15281 	uint32_t us_rtt;
15282 	/*
15283 	 * A persist or keep-alive was forced out, update our
15284 	 * min rtt time. Note now worry about lost responses.
15285 	 * When a subsequent keep-alive or persist times out
15286 	 * and forced_ack is still on, then the last probe
15287 	 * was not responded to. In such cases we have a
15288 	 * sysctl that controls the behavior. Either we apply
15289 	 * the rtt but with reduced confidence (0). Or we just
15290 	 * plain don't apply the rtt estimate. Having data flow
15291 	 * will clear the probe_not_answered flag i.e. cum-ack
15292 	 * move forward <or> exiting and reentering persists.
15293 	 */
15294 
15295 	rack->forced_ack = 0;
15296 	rack->rc_tp->t_rxtshift = 0;
15297 	if ((rack->rc_in_persist &&
15298 	     (tiwin == rack->rc_tp->snd_wnd)) ||
15299 	    (rack->rc_in_persist == 0)) {
15300 		/*
15301 		 * In persists only apply the RTT update if this is
15302 		 * a response to our window probe. And that
15303 		 * means the rwnd sent must match the current
15304 		 * snd_wnd. If it does not, then we got a
15305 		 * window update ack instead. For keepalive
15306 		 * we allow the answer no matter what the window.
15307 		 *
15308 		 * Note that if the probe_not_answered is set then
15309 		 * the forced_ack_ts is the oldest one i.e. the first
15310 		 * probe sent that might have been lost. This assures
15311 		 * us that if we do calculate an RTT it is longer not
15312 		 * some short thing.
15313 		 */
15314 		if (rack->rc_in_persist)
15315 			counter_u64_add(rack_persists_acks, 1);
15316 		us_rtt = us_cts - rack->r_ctl.forced_ack_ts;
15317 		if (us_rtt == 0)
15318 			us_rtt = 1;
15319 		if (rack->probe_not_answered == 0) {
15320 			rack_apply_updated_usrtt(rack, us_rtt, us_cts);
15321 			tcp_rack_xmit_timer(rack, us_rtt, 0, us_rtt, 3, NULL, 1);
15322 		} else {
15323 			/* We have a retransmitted probe here too */
15324 			if (rack_apply_rtt_with_reduced_conf) {
15325 				rack_apply_updated_usrtt(rack, us_rtt, us_cts);
15326 				tcp_rack_xmit_timer(rack, us_rtt, 0, us_rtt, 0, NULL, 1);
15327 			}
15328 		}
15329 	}
15330 }
15331 
15332 static void
15333 rack_new_round_starts(struct tcpcb *tp, struct tcp_rack *rack, uint32_t high_seq)
15334 {
15335 	/*
15336 	 * The next send has occurred mark the end of the round
15337 	 * as when that data gets acknowledged. We can
15338 	 * also do common things we might need to do when
15339 	 * a round begins.
15340 	 */
15341 	rack->r_ctl.roundends = tp->snd_max;
15342 	rack->rc_new_rnd_needed = 0;
15343 	rack_log_hystart_event(rack, tp->snd_max, 4);
15344 }
15345 
15346 
15347 static void
15348 rack_log_pcm(struct tcp_rack *rack, uint8_t mod, uint32_t flex1, uint32_t flex2,
15349 	     uint32_t flex3)
15350 {
15351 	if (tcp_bblogging_on(rack->rc_tp)) {
15352 		union tcp_log_stackspecific log;
15353 		struct timeval tv;
15354 
15355 		(void)tcp_get_usecs(&tv);
15356 		memset(&log, 0, sizeof(log));
15357 		log.u_bbr.timeStamp = tcp_tv_to_usec(&tv);
15358 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
15359 		log.u_bbr.flex8 = mod;
15360 		log.u_bbr.flex1 = flex1;
15361 		log.u_bbr.flex2 = flex2;
15362 		log.u_bbr.flex3 = flex3;
15363 		log.u_bbr.flex4 = rack_pcm_every_n_rounds;
15364 		log.u_bbr.flex5 = rack->r_ctl.pcm_idle_rounds;
15365 		log.u_bbr.bbr_substate = rack->pcm_needed;
15366 		log.u_bbr.bbr_substate <<= 1;
15367 		log.u_bbr.bbr_substate |= rack->pcm_in_progress;
15368 		log.u_bbr.bbr_substate <<= 1;
15369 		log.u_bbr.bbr_substate |= rack->pcm_enabled; /* bits are NIE for Needed, Inprogress, Enabled */
15370 		(void)tcp_log_event(rack->rc_tp, NULL, NULL, NULL, TCP_PCM_MEASURE, ERRNO_UNK,
15371 				    0, &log, false, NULL, NULL, 0, &tv);
15372 	}
15373 }
15374 
15375 static void
15376 rack_new_round_setup(struct tcpcb *tp, struct tcp_rack *rack, uint32_t high_seq)
15377 {
15378 	/*
15379 	 * The round (current_round) has ended. We now
15380 	 * setup for the next round by incrementing the
15381 	 * round numnber and doing any round specific
15382 	 * things.
15383 	 */
15384 	rack_log_hystart_event(rack, high_seq, 21);
15385 	rack->r_ctl.current_round++;
15386 	/* New round (current_round) begins at next send */
15387 	rack->rc_new_rnd_needed = 1;
15388 	if ((rack->pcm_enabled == 1) &&
15389 	    (rack->pcm_needed == 0) &&
15390 	    (rack->pcm_in_progress == 0)) {
15391 		/*
15392 		 * If we have enabled PCM, then we need to
15393 		 * check if the round has adanced to the state
15394 		 * where one is required.
15395 		 */
15396 		int rnds;
15397 
15398 		rnds = rack->r_ctl.current_round - rack->r_ctl.last_pcm_round;
15399 		if ((rnds + rack->r_ctl.pcm_idle_rounds) >= rack_pcm_every_n_rounds) {
15400 			rack->pcm_needed = 1;
15401 			rack_log_pcm(rack, 3, rack->r_ctl.last_pcm_round, rack_pcm_every_n_rounds, rack->r_ctl.current_round );
15402 		} else if (rack_verbose_logging) {
15403 			rack_log_pcm(rack, 3, rack->r_ctl.last_pcm_round, rack_pcm_every_n_rounds, rack->r_ctl.current_round );
15404 		}
15405 	}
15406 	if (tp->t_ccv.flags & CCF_HYSTART_ALLOWED) {
15407 		/* We have hystart enabled send the round info in */
15408 		if (CC_ALGO(tp)->newround != NULL) {
15409 			CC_ALGO(tp)->newround(&tp->t_ccv, rack->r_ctl.current_round);
15410 		}
15411 	}
15412 	/*
15413 	 * For DGP an initial startup check. We want to validate
15414 	 * that we are not just pushing on slow-start and just
15415 	 * not gaining.. i.e. filling buffers without getting any
15416 	 * boost in b/w during the inital slow-start.
15417 	 */
15418 	if (rack->dgp_on &&
15419 	    (rack->rc_initial_ss_comp == 0) &&
15420 	    (tp->snd_cwnd < tp->snd_ssthresh) &&
15421 	    (rack->r_ctl.num_measurements >= RACK_REQ_AVG) &&
15422 	    (rack->r_ctl.gp_rnd_thresh > 0) &&
15423 	    ((rack->r_ctl.current_round - rack->r_ctl.last_rnd_of_gp_rise) >= rack->r_ctl.gp_rnd_thresh)) {
15424 
15425 		/*
15426 		 * We are in the initial SS and we have hd rack_rnd_cnt_req rounds(def:5) where
15427 		 * we have not gained the required amount in the gp_est (120.0% aka 1200). Lets
15428 		 * exit SS.
15429 		 *
15430 		 * Pick up the flight size now as we enter slowstart (not the
15431 		 * cwnd which may be inflated).
15432 		 */
15433 		rack->rc_initial_ss_comp = 1;
15434 
15435 		if (tcp_bblogging_on(rack->rc_tp)) {
15436 			union tcp_log_stackspecific log;
15437 			struct timeval tv;
15438 
15439 			memset(&log, 0, sizeof(log));
15440 			log.u_bbr.timeStamp = tcp_get_usecs(&tv);
15441 			log.u_bbr.flex1 = rack->r_ctl.current_round;
15442 			log.u_bbr.flex2 = rack->r_ctl.last_rnd_of_gp_rise;
15443 			log.u_bbr.flex3 = rack->r_ctl.gp_rnd_thresh;
15444 			log.u_bbr.flex4 = rack->r_ctl.gate_to_fs;
15445 			log.u_bbr.flex5 = rack->r_ctl.ss_hi_fs;
15446 			log.u_bbr.flex8 = 40;
15447 			(void)tcp_log_event(tp, NULL, NULL, NULL, BBR_LOG_CWND, 0,
15448 					    0, &log, false, NULL, __func__, __LINE__,&tv);
15449 		}
15450 		if ((rack->r_ctl.gate_to_fs == 1) &&
15451 		     (tp->snd_cwnd > rack->r_ctl.ss_hi_fs)) {
15452 			tp->snd_cwnd = rack->r_ctl.ss_hi_fs;
15453 		}
15454 		tp->snd_ssthresh = tp->snd_cwnd - 1;
15455 		/* Turn off any fast output running */
15456 		rack->r_fast_output = 0;
15457 	}
15458 }
15459 
15460 static int
15461 rack_do_compressed_ack_processing(struct tcpcb *tp, struct socket *so, struct mbuf *m, int nxt_pkt, struct timeval *tv)
15462 {
15463 	/*
15464 	 * Handle a "special" compressed ack mbuf. Each incoming
15465 	 * ack has only four possible dispositions:
15466 	 *
15467 	 * A) It moves the cum-ack forward
15468 	 * B) It is behind the cum-ack.
15469 	 * C) It is a window-update ack.
15470 	 * D) It is a dup-ack.
15471 	 *
15472 	 * Note that we can have between 1 -> TCP_COMP_ACK_ENTRIES
15473 	 * in the incoming mbuf. We also need to still pay attention
15474 	 * to nxt_pkt since there may be another packet after this
15475 	 * one.
15476 	 */
15477 #ifdef TCP_ACCOUNTING
15478 	uint64_t ts_val;
15479 	uint64_t rdstc;
15480 #endif
15481 	int segsiz;
15482 	struct timespec ts;
15483 	struct tcp_rack *rack;
15484 	struct tcp_ackent *ae;
15485 	uint32_t tiwin, ms_cts, cts, acked, acked_amount, high_seq, win_seq, the_win, win_upd_ack;
15486 	int cnt, i, did_out, ourfinisacked = 0;
15487 	struct tcpopt to_holder, *to = NULL;
15488 #ifdef TCP_ACCOUNTING
15489 	int win_up_req = 0;
15490 #endif
15491 	int nsegs = 0;
15492 	int under_pacing = 0;
15493 	int post_recovery = 0;
15494 #ifdef TCP_ACCOUNTING
15495 	sched_pin();
15496 #endif
15497 	rack = (struct tcp_rack *)tp->t_fb_ptr;
15498 	if (rack->gp_ready &&
15499 	    (rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT))
15500 		under_pacing = 1;
15501 
15502 	if (rack->r_state != tp->t_state)
15503 		rack_set_state(tp, rack);
15504 	if ((tp->t_state >= TCPS_FIN_WAIT_1) &&
15505 	    (tp->t_flags & TF_GPUTINPROG)) {
15506 		/*
15507 		 * We have a goodput in progress
15508 		 * and we have entered a late state.
15509 		 * Do we have enough data in the sb
15510 		 * to handle the GPUT request?
15511 		 */
15512 		uint32_t bytes;
15513 
15514 		bytes = tp->gput_ack - tp->gput_seq;
15515 		if (SEQ_GT(tp->gput_seq, tp->snd_una))
15516 			bytes += tp->gput_seq - tp->snd_una;
15517 		if (bytes > sbavail(&tptosocket(tp)->so_snd)) {
15518 			/*
15519 			 * There are not enough bytes in the socket
15520 			 * buffer that have been sent to cover this
15521 			 * measurement. Cancel it.
15522 			 */
15523 			rack_log_pacing_delay_calc(rack, (tp->gput_ack - tp->gput_seq) /*flex2*/,
15524 						   rack->r_ctl.rc_gp_srtt /*flex1*/,
15525 						   tp->gput_seq,
15526 						   0, 0, 18, __LINE__, NULL, 0);
15527 			tp->t_flags &= ~TF_GPUTINPROG;
15528 		}
15529 	}
15530 	to = &to_holder;
15531 	to->to_flags = 0;
15532 	KASSERT((m->m_len >= sizeof(struct tcp_ackent)),
15533 		("tp:%p m_cmpack:%p with invalid len:%u", tp, m, m->m_len));
15534 	cnt = m->m_len / sizeof(struct tcp_ackent);
15535 	counter_u64_add(rack_multi_single_eq, cnt);
15536 	high_seq = tp->snd_una;
15537 	the_win = tp->snd_wnd;
15538 	win_seq = tp->snd_wl1;
15539 	win_upd_ack = tp->snd_wl2;
15540 	cts = tcp_tv_to_usec(tv);
15541 	ms_cts = tcp_tv_to_msec(tv);
15542 	rack->r_ctl.rc_rcvtime = cts;
15543 	segsiz = ctf_fixed_maxseg(tp);
15544 	if ((rack->rc_gp_dyn_mul) &&
15545 	    (rack->use_fixed_rate == 0) &&
15546 	    (rack->rc_always_pace)) {
15547 		/* Check in on probertt */
15548 		rack_check_probe_rtt(rack, cts);
15549 	}
15550 	for (i = 0; i < cnt; i++) {
15551 #ifdef TCP_ACCOUNTING
15552 		ts_val = get_cyclecount();
15553 #endif
15554 		rack_clear_rate_sample(rack);
15555 		ae = ((mtod(m, struct tcp_ackent *)) + i);
15556 		if (ae->flags & TH_FIN)
15557 			rack_log_pacing_delay_calc(rack,
15558 						   0,
15559 						   0,
15560 						   0,
15561 						   rack_get_gp_est(rack), /* delRate */
15562 						   rack_get_lt_bw(rack), /* rttProp */
15563 						   20, __LINE__, NULL, 0);
15564 		/* Setup the window */
15565 		tiwin = ae->win << tp->snd_scale;
15566 		if (tiwin > rack->r_ctl.rc_high_rwnd)
15567 			rack->r_ctl.rc_high_rwnd = tiwin;
15568 		/* figure out the type of ack */
15569 		if (SEQ_LT(ae->ack, high_seq)) {
15570 			/* Case B*/
15571 			ae->ack_val_set = ACK_BEHIND;
15572 		} else if (SEQ_GT(ae->ack, high_seq)) {
15573 			/* Case A */
15574 			ae->ack_val_set = ACK_CUMACK;
15575 		} else if ((tiwin == the_win) && (rack->rc_in_persist == 0)){
15576 			/* Case D */
15577 			ae->ack_val_set = ACK_DUPACK;
15578 		} else {
15579 			/* Case C */
15580 			ae->ack_val_set = ACK_RWND;
15581 		}
15582 		rack_log_type_bbrsnd(rack, 0, 0, cts, tv, __LINE__);
15583 		rack_log_input_packet(tp, rack, ae, ae->ack_val_set, high_seq);
15584 		/* Validate timestamp */
15585 		if (ae->flags & HAS_TSTMP) {
15586 			/* Setup for a timestamp */
15587 			to->to_flags = TOF_TS;
15588 			ae->ts_echo -= tp->ts_offset;
15589 			to->to_tsecr = ae->ts_echo;
15590 			to->to_tsval = ae->ts_value;
15591 			/*
15592 			 * If echoed timestamp is later than the current time, fall back to
15593 			 * non RFC1323 RTT calculation.  Normalize timestamp if syncookies
15594 			 * were used when this connection was established.
15595 			 */
15596 			if (TSTMP_GT(ae->ts_echo, ms_cts))
15597 				to->to_tsecr = 0;
15598 			if (tp->ts_recent &&
15599 			    TSTMP_LT(ae->ts_value, tp->ts_recent)) {
15600 				if (ctf_ts_check_ac(tp, (ae->flags & 0xff))) {
15601 #ifdef TCP_ACCOUNTING
15602 					rdstc = get_cyclecount();
15603 					if (rdstc > ts_val) {
15604 						if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
15605 							tp->tcp_proc_time[ae->ack_val_set] += (rdstc - ts_val);
15606 						}
15607 					}
15608 #endif
15609 					continue;
15610 				}
15611 			}
15612 			if (SEQ_LEQ(ae->seq, tp->last_ack_sent) &&
15613 			    SEQ_LEQ(tp->last_ack_sent, ae->seq)) {
15614 				tp->ts_recent_age = tcp_ts_getticks();
15615 				tp->ts_recent = ae->ts_value;
15616 			}
15617 		} else {
15618 			/* Setup for a no options */
15619 			to->to_flags = 0;
15620 		}
15621 		/* Update the rcv time and perform idle reduction possibly */
15622 		if  (tp->t_idle_reduce &&
15623 		     (tp->snd_max == tp->snd_una) &&
15624 		     (TICKS_2_USEC(ticks - tp->t_rcvtime) >= tp->t_rxtcur)) {
15625 			counter_u64_add(rack_input_idle_reduces, 1);
15626 			rack_cc_after_idle(rack, tp);
15627 		}
15628 		tp->t_rcvtime = ticks;
15629 		/* Now what about ECN of a chain of pure ACKs? */
15630 		if (tcp_ecn_input_segment(tp, ae->flags, 0,
15631 			tcp_packets_this_ack(tp, ae->ack),
15632 			ae->codepoint))
15633 			rack_cong_signal(tp, CC_ECN, ae->ack, __LINE__);
15634 #ifdef TCP_ACCOUNTING
15635 		/* Count for the specific type of ack in */
15636 		if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
15637 			tp->tcp_cnt_counters[ae->ack_val_set]++;
15638 		}
15639 #endif
15640 		/*
15641 		 * Note how we could move up these in the determination
15642 		 * above, but we don't so that way the timestamp checks (and ECN)
15643 		 * is done first before we do any processing on the ACK.
15644 		 * The non-compressed path through the code has this
15645 		 * weakness (noted by @jtl) that it actually does some
15646 		 * processing before verifying the timestamp information.
15647 		 * We don't take that path here which is why we set
15648 		 * the ack_val_set first, do the timestamp and ecn
15649 		 * processing, and then look at what we have setup.
15650 		 */
15651 		if (ae->ack_val_set == ACK_BEHIND) {
15652 			/*
15653 			 * Case B flag reordering, if window is not closed
15654 			 * or it could be a keep-alive or persists
15655 			 */
15656 			if (SEQ_LT(ae->ack, tp->snd_una) && (sbspace(&so->so_rcv) > segsiz)) {
15657 				rack->r_ctl.rc_reorder_ts = tcp_tv_to_usec(&rack->r_ctl.act_rcv_time);
15658 				if (rack->r_ctl.rc_reorder_ts == 0)
15659 					rack->r_ctl.rc_reorder_ts = 1;
15660 			}
15661 		} else if (ae->ack_val_set == ACK_DUPACK) {
15662 			/* Case D */
15663 			rack_strike_dupack(rack, ae->ack);
15664 		} else if (ae->ack_val_set == ACK_RWND) {
15665 			/* Case C */
15666 			if ((ae->flags & TSTMP_LRO) || (ae->flags & TSTMP_HDWR)) {
15667 				ts.tv_sec = ae->timestamp / 1000000000;
15668 				ts.tv_nsec = ae->timestamp % 1000000000;
15669 				rack->r_ctl.act_rcv_time.tv_sec = ts.tv_sec;
15670 				rack->r_ctl.act_rcv_time.tv_usec = ts.tv_nsec/1000;
15671 			} else {
15672 				rack->r_ctl.act_rcv_time = *tv;
15673 			}
15674 			if (rack->forced_ack) {
15675 				rack_handle_probe_response(rack, tiwin,
15676 							   tcp_tv_to_usec(&rack->r_ctl.act_rcv_time));
15677 			}
15678 #ifdef TCP_ACCOUNTING
15679 			win_up_req = 1;
15680 #endif
15681 			win_upd_ack = ae->ack;
15682 			win_seq = ae->seq;
15683 			the_win = tiwin;
15684 			rack_do_win_updates(tp, rack, the_win, win_seq, win_upd_ack, cts);
15685 		} else {
15686 			/* Case A */
15687 			if (SEQ_GT(ae->ack, tp->snd_max)) {
15688 				/*
15689 				 * We just send an ack since the incoming
15690 				 * ack is beyond the largest seq we sent.
15691 				 */
15692 				if ((tp->t_flags & TF_ACKNOW) == 0) {
15693 					ctf_ack_war_checks(tp);
15694 					if (tp->t_flags && TF_ACKNOW)
15695 						rack->r_wanted_output = 1;
15696 				}
15697 			} else {
15698 				nsegs++;
15699 				/* If the window changed setup to update */
15700 				if (tiwin != tp->snd_wnd) {
15701 					win_upd_ack = ae->ack;
15702 					win_seq = ae->seq;
15703 					the_win = tiwin;
15704 					rack_do_win_updates(tp, rack, the_win, win_seq, win_upd_ack, cts);
15705 				}
15706 #ifdef TCP_ACCOUNTING
15707 				/* Account for the acks */
15708 				if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
15709 					tp->tcp_cnt_counters[CNT_OF_ACKS_IN] += (((ae->ack - high_seq) + segsiz - 1) / segsiz);
15710 				}
15711 #endif
15712 				high_seq = ae->ack;
15713 				/* Setup our act_rcv_time */
15714 				if ((ae->flags & TSTMP_LRO) || (ae->flags & TSTMP_HDWR)) {
15715 					ts.tv_sec = ae->timestamp / 1000000000;
15716 					ts.tv_nsec = ae->timestamp % 1000000000;
15717 					rack->r_ctl.act_rcv_time.tv_sec = ts.tv_sec;
15718 					rack->r_ctl.act_rcv_time.tv_usec = ts.tv_nsec/1000;
15719 				} else {
15720 					rack->r_ctl.act_rcv_time = *tv;
15721 				}
15722 				rack_process_to_cumack(tp, rack, ae->ack, cts, to,
15723 						       tcp_tv_to_lusec(&rack->r_ctl.act_rcv_time));
15724 #ifdef TCP_REQUEST_TRK
15725 				rack_req_check_for_comp(rack, high_seq);
15726 #endif
15727 				if (rack->rc_dsack_round_seen) {
15728 					/* Is the dsack round over? */
15729 					if (SEQ_GEQ(ae->ack, rack->r_ctl.dsack_round_end)) {
15730 						/* Yes it is */
15731 						rack->rc_dsack_round_seen = 0;
15732 						rack_log_dsack_event(rack, 3, __LINE__, 0, 0);
15733 					}
15734 				}
15735 			}
15736 		}
15737 		/* And lets be sure to commit the rtt measurements for this ack */
15738 		tcp_rack_xmit_timer_commit(rack, tp);
15739 #ifdef TCP_ACCOUNTING
15740 		rdstc = get_cyclecount();
15741 		if (rdstc > ts_val) {
15742 			if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
15743 				tp->tcp_proc_time[ae->ack_val_set] += (rdstc - ts_val);
15744 				if (ae->ack_val_set == ACK_CUMACK)
15745 					tp->tcp_proc_time[CYC_HANDLE_MAP] += (rdstc - ts_val);
15746 			}
15747 		}
15748 #endif
15749 	}
15750 #ifdef TCP_ACCOUNTING
15751 	ts_val = get_cyclecount();
15752 #endif
15753 	/* Tend to any collapsed window */
15754 	if (SEQ_GT(tp->snd_max, high_seq) && (tp->snd_wnd < (tp->snd_max - high_seq))) {
15755 		/* The peer collapsed the window */
15756 		rack_collapsed_window(rack, (tp->snd_max - high_seq), high_seq, __LINE__);
15757 	} else if (rack->rc_has_collapsed)
15758 		rack_un_collapse_window(rack, __LINE__);
15759 	if ((rack->r_collapse_point_valid) &&
15760 	    (SEQ_GT(high_seq, rack->r_ctl.high_collapse_point)))
15761 		rack->r_collapse_point_valid = 0;
15762 	acked_amount = acked = (high_seq - tp->snd_una);
15763 	if (acked) {
15764 		/*
15765 		 * The draft (v3) calls for us to use SEQ_GEQ, but that
15766 		 * causes issues when we are just going app limited. Lets
15767 		 * instead use SEQ_GT <or> where its equal but more data
15768 		 * is outstanding.
15769 		 *
15770 		 * Also make sure we are on the last ack of a series. We
15771 		 * have to have all the ack's processed in queue to know
15772 		 * if there is something left outstanding.
15773 		 *
15774 		 */
15775 		if (SEQ_GEQ(high_seq, rack->r_ctl.roundends) &&
15776 		    (rack->rc_new_rnd_needed == 0) &&
15777 		    (nxt_pkt == 0)) {
15778 			/*
15779 			 * We have crossed into a new round with
15780 			 * this th_ack value.
15781 			 */
15782 			rack_new_round_setup(tp, rack, high_seq);
15783 		}
15784 		/*
15785 		 * Clear the probe not answered flag
15786 		 * since cum-ack moved forward.
15787 		 */
15788 		rack->probe_not_answered = 0;
15789 		if (tp->t_flags & TF_NEEDSYN) {
15790 			/*
15791 			 * T/TCP: Connection was half-synchronized, and our SYN has
15792 			 * been ACK'd (so connection is now fully synchronized).  Go
15793 			 * to non-starred state, increment snd_una for ACK of SYN,
15794 			 * and check if we can do window scaling.
15795 			 */
15796 			tp->t_flags &= ~TF_NEEDSYN;
15797 			tp->snd_una++;
15798 			acked_amount = acked = (high_seq - tp->snd_una);
15799 		}
15800 		if (acked > sbavail(&so->so_snd))
15801 			acked_amount = sbavail(&so->so_snd);
15802 		if (IN_FASTRECOVERY(tp->t_flags) &&
15803 		    (rack->rack_no_prr == 0))
15804 			rack_update_prr(tp, rack, acked_amount, high_seq);
15805 		if (IN_RECOVERY(tp->t_flags)) {
15806 			if (SEQ_LT(high_seq, tp->snd_recover) &&
15807 			    (SEQ_LT(high_seq, tp->snd_max))) {
15808 				tcp_rack_partialack(tp);
15809 			} else {
15810 				rack_post_recovery(tp, high_seq);
15811 				post_recovery = 1;
15812 			}
15813 		}  else if ((rack->rto_from_rec == 1) &&
15814 			    SEQ_GEQ(high_seq, tp->snd_recover)) {
15815 			/*
15816 			 * We were in recovery, hit a rxt timeout
15817 			 * and never re-entered recovery. The timeout(s)
15818 			 * made up all the lost data. In such a case
15819 			 * we need to clear the rto_from_rec flag.
15820 			 */
15821 			rack->rto_from_rec = 0;
15822 		}
15823 		/* Handle the rack-log-ack part (sendmap) */
15824 		if ((sbused(&so->so_snd) == 0) &&
15825 		    (acked > acked_amount) &&
15826 		    (tp->t_state >= TCPS_FIN_WAIT_1) &&
15827 		    (tp->t_flags & TF_SENTFIN)) {
15828 			/*
15829 			 * We must be sure our fin
15830 			 * was sent and acked (we can be
15831 			 * in FIN_WAIT_1 without having
15832 			 * sent the fin).
15833 			 */
15834 			ourfinisacked = 1;
15835 			/*
15836 			 * Lets make sure snd_una is updated
15837 			 * since most likely acked_amount = 0 (it
15838 			 * should be).
15839 			 */
15840 			tp->snd_una = high_seq;
15841 		}
15842 		/* Did we make a RTO error? */
15843 		if ((tp->t_flags & TF_PREVVALID) &&
15844 		    ((tp->t_flags & TF_RCVD_TSTMP) == 0)) {
15845 			tp->t_flags &= ~TF_PREVVALID;
15846 			if (tp->t_rxtshift == 1 &&
15847 			    (int)(ticks - tp->t_badrxtwin) < 0)
15848 				rack_cong_signal(tp, CC_RTO_ERR, high_seq, __LINE__);
15849 		}
15850 		/* Handle the data in the socket buffer */
15851 		KMOD_TCPSTAT_ADD(tcps_rcvackpack, 1);
15852 		KMOD_TCPSTAT_ADD(tcps_rcvackbyte, acked);
15853 		if (acked_amount > 0) {
15854 			uint32_t p_cwnd;
15855 			struct mbuf *mfree;
15856 
15857 			if (post_recovery) {
15858 				/*
15859 				 * Grab the segsiz, multiply by 2 and add the snd_cwnd
15860 				 * that is the max the CC should add if we are exiting
15861 				 * recovery and doing a late add.
15862 				 */
15863 				p_cwnd = min(ctf_fixed_maxseg(tp), rack->r_ctl.rc_pace_min_segs);
15864 				p_cwnd <<= 1;
15865 				p_cwnd += tp->snd_cwnd;
15866 			}
15867 			rack_ack_received(tp, rack, high_seq, nsegs, CC_ACK, post_recovery);
15868 			if (post_recovery && (tp->snd_cwnd > p_cwnd)) {
15869 				/* Must be non-newreno (cubic) getting too ahead of itself */
15870 				tp->snd_cwnd = p_cwnd;
15871 			}
15872 			SOCK_SENDBUF_LOCK(so);
15873 			mfree = sbcut_locked(&so->so_snd, acked_amount);
15874 			tp->snd_una = high_seq;
15875 			/* Note we want to hold the sb lock through the sendmap adjust */
15876 			rack_adjust_sendmap_head(rack, &so->so_snd);
15877 			/* Wake up the socket if we have room to write more */
15878 			rack_log_wakeup(tp,rack, &so->so_snd, acked, 2);
15879 			sowwakeup_locked(so);
15880 			m_freem(mfree);
15881 		}
15882 		/* update progress */
15883 		tp->t_acktime = ticks;
15884 		rack_log_progress_event(rack, tp, tp->t_acktime,
15885 					PROGRESS_UPDATE, __LINE__);
15886 		/* Clear out shifts and such */
15887 		tp->t_rxtshift = 0;
15888 		RACK_TCPT_RANGESET(tp->t_rxtcur, RACK_REXMTVAL(tp),
15889 				   rack_rto_min, rack_rto_max, rack->r_ctl.timer_slop);
15890 		rack->rc_tlp_in_progress = 0;
15891 		rack->r_ctl.rc_tlp_cnt_out = 0;
15892 		/* Send recover and snd_nxt must be dragged along */
15893 		if (SEQ_GT(tp->snd_una, tp->snd_recover))
15894 			tp->snd_recover = tp->snd_una;
15895 		if (SEQ_LT(tp->snd_nxt, tp->snd_max))
15896 			tp->snd_nxt = tp->snd_max;
15897 		/*
15898 		 * If the RXT timer is running we want to
15899 		 * stop it, so we can restart a TLP (or new RXT).
15900 		 */
15901 		if (rack->r_ctl.rc_hpts_flags & PACE_TMR_RXT)
15902 			rack_timer_cancel(tp, rack, rack->r_ctl.rc_rcvtime, __LINE__);
15903 		tp->snd_wl2 = high_seq;
15904 		tp->t_dupacks = 0;
15905 		if (under_pacing &&
15906 		    (rack->use_fixed_rate == 0) &&
15907 		    (rack->in_probe_rtt == 0) &&
15908 		    rack->rc_gp_dyn_mul &&
15909 		    rack->rc_always_pace) {
15910 			/* Check if we are dragging bottom */
15911 			rack_check_bottom_drag(tp, rack, so);
15912 		}
15913 		if (tp->snd_una == tp->snd_max) {
15914 			tp->t_flags &= ~TF_PREVVALID;
15915 			rack->r_ctl.retran_during_recovery = 0;
15916 			rack->rc_suspicious = 0;
15917 			rack->r_ctl.dsack_byte_cnt = 0;
15918 			rack->r_ctl.rc_went_idle_time = tcp_get_usecs(NULL);
15919 			if (rack->r_ctl.rc_went_idle_time == 0)
15920 				rack->r_ctl.rc_went_idle_time = 1;
15921 			rack_log_progress_event(rack, tp, 0, PROGRESS_CLEAR, __LINE__);
15922 			if (sbavail(&tptosocket(tp)->so_snd) == 0)
15923 				tp->t_acktime = 0;
15924 			/* Set so we might enter persists... */
15925 			rack->r_wanted_output = 1;
15926 			rack_timer_cancel(tp, rack, rack->r_ctl.rc_rcvtime, __LINE__);
15927 			sack_filter_clear(&rack->r_ctl.rack_sf, tp->snd_una);
15928 			if ((tp->t_state >= TCPS_FIN_WAIT_1) &&
15929 			    (sbavail(&so->so_snd) == 0) &&
15930 			    (tp->t_flags2 & TF2_DROP_AF_DATA)) {
15931 				/*
15932 				 * The socket was gone and the
15933 				 * peer sent data (not now in the past), time to
15934 				 * reset him.
15935 				 */
15936 				rack_timer_cancel(tp, rack, rack->r_ctl.rc_rcvtime, __LINE__);
15937 				/* tcp_close will kill the inp pre-log the Reset */
15938 				tcp_log_end_status(tp, TCP_EI_STATUS_SERVER_RST);
15939 #ifdef TCP_ACCOUNTING
15940 				rdstc = get_cyclecount();
15941 				if (rdstc > ts_val) {
15942 					if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
15943 						tp->tcp_proc_time[ACK_CUMACK] += (rdstc - ts_val);
15944 						tp->tcp_proc_time[CYC_HANDLE_ACK] += (rdstc - ts_val);
15945 					}
15946 				}
15947 #endif
15948 				m_freem(m);
15949 				tp = tcp_close(tp);
15950 				if (tp == NULL) {
15951 #ifdef TCP_ACCOUNTING
15952 					sched_unpin();
15953 #endif
15954 					return (1);
15955 				}
15956 				/*
15957 				 * We would normally do drop-with-reset which would
15958 				 * send back a reset. We can't since we don't have
15959 				 * all the needed bits. Instead lets arrange for
15960 				 * a call to tcp_output(). That way since we
15961 				 * are in the closed state we will generate a reset.
15962 				 *
15963 				 * Note if tcp_accounting is on we don't unpin since
15964 				 * we do that after the goto label.
15965 				 */
15966 				goto send_out_a_rst;
15967 			}
15968 			if ((sbused(&so->so_snd) == 0) &&
15969 			    (tp->t_state >= TCPS_FIN_WAIT_1) &&
15970 			    (tp->t_flags & TF_SENTFIN)) {
15971 				/*
15972 				 * If we can't receive any more data, then closing user can
15973 				 * proceed. Starting the timer is contrary to the
15974 				 * specification, but if we don't get a FIN we'll hang
15975 				 * forever.
15976 				 *
15977 				 */
15978 				if (so->so_rcv.sb_state & SBS_CANTRCVMORE) {
15979 					soisdisconnected(so);
15980 					tcp_timer_activate(tp, TT_2MSL,
15981 							   (tcp_fast_finwait2_recycle ?
15982 							    tcp_finwait2_timeout :
15983 							    TP_MAXIDLE(tp)));
15984 				}
15985 				if (ourfinisacked == 0) {
15986 					/*
15987 					 * We don't change to fin-wait-2 if we have our fin acked
15988 					 * which means we are probably in TCPS_CLOSING.
15989 					 */
15990 					tcp_state_change(tp, TCPS_FIN_WAIT_2);
15991 				}
15992 			}
15993 		}
15994 		/* Wake up the socket if we have room to write more */
15995 		if (sbavail(&so->so_snd)) {
15996 			rack->r_wanted_output = 1;
15997 			if (ctf_progress_timeout_check(tp, true)) {
15998 				rack_log_progress_event((struct tcp_rack *)tp->t_fb_ptr,
15999 							tp, tick, PROGRESS_DROP, __LINE__);
16000 				/*
16001 				 * We cheat here and don't send a RST, we should send one
16002 				 * when the pacer drops the connection.
16003 				 */
16004 #ifdef TCP_ACCOUNTING
16005 				rdstc = get_cyclecount();
16006 				if (rdstc > ts_val) {
16007 					if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
16008 						tp->tcp_proc_time[ACK_CUMACK] += (rdstc - ts_val);
16009 						tp->tcp_proc_time[CYC_HANDLE_ACK] += (rdstc - ts_val);
16010 					}
16011 				}
16012 				sched_unpin();
16013 #endif
16014 				(void)tcp_drop(tp, ETIMEDOUT);
16015 				m_freem(m);
16016 				return (1);
16017 			}
16018 		}
16019 		if (ourfinisacked) {
16020 			switch(tp->t_state) {
16021 			case TCPS_CLOSING:
16022 #ifdef TCP_ACCOUNTING
16023 				rdstc = get_cyclecount();
16024 				if (rdstc > ts_val) {
16025 					if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
16026 						tp->tcp_proc_time[ACK_CUMACK] += (rdstc - ts_val);
16027 						tp->tcp_proc_time[CYC_HANDLE_ACK] += (rdstc - ts_val);
16028 					}
16029 				}
16030 				sched_unpin();
16031 #endif
16032 				tcp_twstart(tp);
16033 				m_freem(m);
16034 				return (1);
16035 				break;
16036 			case TCPS_LAST_ACK:
16037 #ifdef TCP_ACCOUNTING
16038 				rdstc = get_cyclecount();
16039 				if (rdstc > ts_val) {
16040 					if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
16041 						tp->tcp_proc_time[ACK_CUMACK] += (rdstc - ts_val);
16042 						tp->tcp_proc_time[CYC_HANDLE_ACK] += (rdstc - ts_val);
16043 					}
16044 				}
16045 				sched_unpin();
16046 #endif
16047 				tp = tcp_close(tp);
16048 				ctf_do_drop(m, tp);
16049 				return (1);
16050 				break;
16051 			case TCPS_FIN_WAIT_1:
16052 #ifdef TCP_ACCOUNTING
16053 				rdstc = get_cyclecount();
16054 				if (rdstc > ts_val) {
16055 					if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
16056 						tp->tcp_proc_time[ACK_CUMACK] += (rdstc - ts_val);
16057 						tp->tcp_proc_time[CYC_HANDLE_ACK] += (rdstc - ts_val);
16058 					}
16059 				}
16060 #endif
16061 				if (so->so_rcv.sb_state & SBS_CANTRCVMORE) {
16062 					soisdisconnected(so);
16063 					tcp_timer_activate(tp, TT_2MSL,
16064 							   (tcp_fast_finwait2_recycle ?
16065 							    tcp_finwait2_timeout :
16066 							    TP_MAXIDLE(tp)));
16067 				}
16068 				tcp_state_change(tp, TCPS_FIN_WAIT_2);
16069 				break;
16070 			default:
16071 				break;
16072 			}
16073 		}
16074 		if (rack->r_fast_output) {
16075 			/*
16076 			 * We re doing fast output.. can we expand that?
16077 			 */
16078 			rack_gain_for_fastoutput(rack, tp, so, acked_amount);
16079 		}
16080 #ifdef TCP_ACCOUNTING
16081 		rdstc = get_cyclecount();
16082 		if (rdstc > ts_val) {
16083 			if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
16084 				tp->tcp_proc_time[ACK_CUMACK] += (rdstc - ts_val);
16085 				tp->tcp_proc_time[CYC_HANDLE_ACK] += (rdstc - ts_val);
16086 			}
16087 		}
16088 
16089 	} else if (win_up_req) {
16090 		rdstc = get_cyclecount();
16091 		if (rdstc > ts_val) {
16092 			if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
16093 				tp->tcp_proc_time[ACK_RWND] += (rdstc - ts_val);
16094 			}
16095 		}
16096 #endif
16097 	}
16098 	/* Now is there a next packet, if so we are done */
16099 	m_freem(m);
16100 	did_out = 0;
16101 	if (nxt_pkt) {
16102 #ifdef TCP_ACCOUNTING
16103 		sched_unpin();
16104 #endif
16105 		rack_log_doseg_done(rack, cts, nxt_pkt, did_out, 5, nsegs);
16106 		return (0);
16107 	}
16108 	rack_handle_might_revert(tp, rack);
16109 	ctf_calc_rwin(so, tp);
16110 	if ((rack->r_wanted_output != 0) ||
16111 	    (rack->r_fast_output != 0) ||
16112 	    (tp->t_flags & TF_ACKNOW )) {
16113 	send_out_a_rst:
16114 		if (tcp_output(tp) < 0) {
16115 #ifdef TCP_ACCOUNTING
16116 			sched_unpin();
16117 #endif
16118 			return (1);
16119 		}
16120 		did_out = 1;
16121 	}
16122 	if (tp->t_flags2 & TF2_HPTS_CALLS)
16123 		tp->t_flags2 &= ~TF2_HPTS_CALLS;
16124 	rack_free_trim(rack);
16125 #ifdef TCP_ACCOUNTING
16126 	sched_unpin();
16127 #endif
16128 	rack_timer_audit(tp, rack, &so->so_snd);
16129 	rack_log_doseg_done(rack, cts, nxt_pkt, did_out, 6, nsegs);
16130 	return (0);
16131 }
16132 
16133 #define	TCP_LRO_TS_OPTION \
16134     ntohl((TCPOPT_NOP << 24) | (TCPOPT_NOP << 16) | \
16135 	  (TCPOPT_TIMESTAMP << 8) | TCPOLEN_TIMESTAMP)
16136 
16137 static int
16138 rack_do_segment_nounlock(struct tcpcb *tp, struct mbuf *m, struct tcphdr *th,
16139     int32_t drop_hdrlen, int32_t tlen, uint8_t iptos, int32_t nxt_pkt,
16140     struct timeval *tv)
16141 {
16142 	struct inpcb *inp = tptoinpcb(tp);
16143 	struct socket *so = tptosocket(tp);
16144 #ifdef TCP_ACCOUNTING
16145 	uint64_t ts_val;
16146 #endif
16147 	int32_t thflags, retval, did_out = 0;
16148 	int32_t way_out = 0;
16149 	/*
16150 	 * cts - is the current time from tv (caller gets ts) in microseconds.
16151 	 * ms_cts - is the current time from tv in milliseconds.
16152 	 * us_cts - is the time that LRO or hardware actually got the packet in microseconds.
16153 	 */
16154 	uint32_t cts, us_cts, ms_cts;
16155 	uint32_t tiwin;
16156 	struct timespec ts;
16157 	struct tcpopt to;
16158 	struct tcp_rack *rack;
16159 	struct rack_sendmap *rsm;
16160 	int32_t prev_state = 0;
16161 	int no_output = 0;
16162 	int time_remaining = 0;
16163 #ifdef TCP_ACCOUNTING
16164 	int ack_val_set = 0xf;
16165 #endif
16166 	int nsegs;
16167 
16168 	NET_EPOCH_ASSERT();
16169 	INP_WLOCK_ASSERT(inp);
16170 
16171 	/*
16172 	 * tv passed from common code is from either M_TSTMP_LRO or
16173 	 * tcp_get_usecs() if no LRO m_pkthdr timestamp is present.
16174 	 */
16175 	rack = (struct tcp_rack *)tp->t_fb_ptr;
16176 	if (rack->rack_deferred_inited == 0) {
16177 		/*
16178 		 * If we are the connecting socket we will
16179 		 * hit rack_init() when no sequence numbers
16180 		 * are setup. This makes it so we must defer
16181 		 * some initialization. Call that now.
16182 		 */
16183 		rack_deferred_init(tp, rack);
16184 	}
16185 	/*
16186 	 * Check to see if we need to skip any output plans. This
16187 	 * can happen in the non-LRO path where we are pacing and
16188 	 * must process the ack coming in but need to defer sending
16189 	 * anything becase a pacing timer is running.
16190 	 */
16191 	us_cts = tcp_tv_to_usec(tv);
16192 	if (m->m_flags & M_ACKCMP) {
16193 		/*
16194 		 * All compressed ack's are ack's by definition so
16195 		 * remove any ack required flag and then do the processing.
16196 		 */
16197 		rack->rc_ack_required = 0;
16198 		return (rack_do_compressed_ack_processing(tp, so, m, nxt_pkt, tv));
16199 	}
16200 	thflags = tcp_get_flags(th);
16201 	if ((rack->rc_always_pace == 1) &&
16202 	    (rack->rc_ack_can_sendout_data == 0) &&
16203 	    (rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT) &&
16204 	    (TSTMP_LT(us_cts, rack->r_ctl.rc_last_output_to))) {
16205 		/*
16206 		 * Ok conditions are right for queuing the packets
16207 		 * but we do have to check the flags in the inp, it
16208 		 * could be, if a sack is present, we want to be awoken and
16209 		 * so should process the packets.
16210 		 */
16211 		time_remaining = rack->r_ctl.rc_last_output_to - us_cts;
16212 		if (rack->rc_tp->t_flags2 & TF2_DONT_SACK_QUEUE) {
16213 			no_output = 1;
16214 		} else {
16215 			/*
16216 			 * If there is no options, or just a
16217 			 * timestamp option, we will want to queue
16218 			 * the packets. This is the same that LRO does
16219 			 * and will need to change with accurate ECN.
16220 			 */
16221 			uint32_t *ts_ptr;
16222 			int optlen;
16223 
16224 			optlen = (th->th_off << 2) - sizeof(struct tcphdr);
16225 			ts_ptr = (uint32_t *)(th + 1);
16226 			if ((optlen == 0) ||
16227 			    ((optlen == TCPOLEN_TSTAMP_APPA) &&
16228 			     (*ts_ptr == TCP_LRO_TS_OPTION)))
16229 				no_output = 1;
16230 		}
16231 		if ((no_output == 1) && (time_remaining < tcp_min_hptsi_time)) {
16232 			/*
16233 			 * It is unrealistic to think we can pace in less than
16234 			 * the minimum granularity of the pacer (def:250usec). So
16235 			 * if we have less than that time remaining we should go
16236 			 * ahead and allow output to be "early". We will attempt to
16237 			 * make up for it in any pacing time we try to apply on
16238 			 * the outbound packet.
16239 			 */
16240 			no_output = 0;
16241 		}
16242 	}
16243 	/*
16244 	 * If there is a RST or FIN lets dump out the bw
16245 	 * with a FIN the connection may go on but we
16246 	 * may not.
16247 	 */
16248 	if ((thflags & TH_FIN) || (thflags & TH_RST))
16249 		rack_log_pacing_delay_calc(rack,
16250 					   rack->r_ctl.gp_bw,
16251 					   0,
16252 					   0,
16253 					   rack_get_gp_est(rack), /* delRate */
16254 					   rack_get_lt_bw(rack), /* rttProp */
16255 					   20, __LINE__, NULL, 0);
16256 	if (m->m_flags & M_ACKCMP) {
16257 		panic("Impossible reach m has ackcmp? m:%p tp:%p", m, tp);
16258 	}
16259 	cts = tcp_tv_to_usec(tv);
16260 	ms_cts =  tcp_tv_to_msec(tv);
16261 	nsegs = m->m_pkthdr.lro_nsegs;
16262 	counter_u64_add(rack_proc_non_comp_ack, 1);
16263 #ifdef TCP_ACCOUNTING
16264 	sched_pin();
16265 	if (thflags & TH_ACK)
16266 		ts_val = get_cyclecount();
16267 #endif
16268 	if ((m->m_flags & M_TSTMP) ||
16269 	    (m->m_flags & M_TSTMP_LRO)) {
16270 		mbuf_tstmp2timespec(m, &ts);
16271 		rack->r_ctl.act_rcv_time.tv_sec = ts.tv_sec;
16272 		rack->r_ctl.act_rcv_time.tv_usec = ts.tv_nsec/1000;
16273 	} else
16274 		rack->r_ctl.act_rcv_time = *tv;
16275 	kern_prefetch(rack, &prev_state);
16276 	prev_state = 0;
16277 	/*
16278 	 * Unscale the window into a 32-bit value. For the SYN_SENT state
16279 	 * the scale is zero.
16280 	 */
16281 	tiwin = th->th_win << tp->snd_scale;
16282 #ifdef TCP_ACCOUNTING
16283 	if (thflags & TH_ACK) {
16284 		/*
16285 		 * We have a tradeoff here. We can either do what we are
16286 		 * doing i.e. pinning to this CPU and then doing the accounting
16287 		 * <or> we could do a critical enter, setup the rdtsc and cpu
16288 		 * as in below, and then validate we are on the same CPU on
16289 		 * exit. I have choosen to not do the critical enter since
16290 		 * that often will gain you a context switch, and instead lock
16291 		 * us (line above this if) to the same CPU with sched_pin(). This
16292 		 * means we may be context switched out for a higher priority
16293 		 * interupt but we won't be moved to another CPU.
16294 		 *
16295 		 * If this occurs (which it won't very often since we most likely
16296 		 * are running this code in interupt context and only a higher
16297 		 * priority will bump us ... clock?) we will falsely add in
16298 		 * to the time the interupt processing time plus the ack processing
16299 		 * time. This is ok since its a rare event.
16300 		 */
16301 		ack_val_set = tcp_do_ack_accounting(tp, th, &to, tiwin,
16302 						    ctf_fixed_maxseg(tp));
16303 	}
16304 #endif
16305 	/*
16306 	 * Parse options on any incoming segment.
16307 	 */
16308 	memset(&to, 0, sizeof(to));
16309 	tcp_dooptions(&to, (u_char *)(th + 1),
16310 	    (th->th_off << 2) - sizeof(struct tcphdr),
16311 	    (thflags & TH_SYN) ? TO_SYN : 0);
16312 	KASSERT(tp->t_state > TCPS_LISTEN, ("%s: TCPS_LISTEN",
16313 	    __func__));
16314 	KASSERT(tp->t_state != TCPS_TIME_WAIT, ("%s: TCPS_TIME_WAIT",
16315 	    __func__));
16316 	if (tp->t_flags2 & TF2_PROC_SACK_PROHIBIT) {
16317 		/*
16318 		 * We don't look at sack's from the
16319 		 * peer because the MSS is too small which
16320 		 * can subject us to an attack.
16321 		 */
16322 		to.to_flags &= ~TOF_SACK;
16323 	}
16324 	if ((tp->t_state >= TCPS_FIN_WAIT_1) &&
16325 	    (tp->t_flags & TF_GPUTINPROG)) {
16326 		/*
16327 		 * We have a goodput in progress
16328 		 * and we have entered a late state.
16329 		 * Do we have enough data in the sb
16330 		 * to handle the GPUT request?
16331 		 */
16332 		uint32_t bytes;
16333 
16334 		bytes = tp->gput_ack - tp->gput_seq;
16335 		if (SEQ_GT(tp->gput_seq, tp->snd_una))
16336 			bytes += tp->gput_seq - tp->snd_una;
16337 		if (bytes > sbavail(&tptosocket(tp)->so_snd)) {
16338 			/*
16339 			 * There are not enough bytes in the socket
16340 			 * buffer that have been sent to cover this
16341 			 * measurement. Cancel it.
16342 			 */
16343 			rack_log_pacing_delay_calc(rack, (tp->gput_ack - tp->gput_seq) /*flex2*/,
16344 						   rack->r_ctl.rc_gp_srtt /*flex1*/,
16345 						   tp->gput_seq,
16346 						   0, 0, 18, __LINE__, NULL, 0);
16347 			tp->t_flags &= ~TF_GPUTINPROG;
16348 		}
16349 	}
16350 	if (tcp_bblogging_on(rack->rc_tp)) {
16351 		union tcp_log_stackspecific log;
16352 		struct timeval ltv;
16353 #ifdef TCP_REQUEST_TRK
16354 		struct tcp_sendfile_track *tcp_req;
16355 
16356 		if (SEQ_GT(th->th_ack, tp->snd_una)) {
16357 			tcp_req = tcp_req_find_req_for_seq(tp, (th->th_ack-1));
16358 		} else {
16359 			tcp_req = tcp_req_find_req_for_seq(tp, th->th_ack);
16360 		}
16361 #endif
16362 		memset(&log, 0, sizeof(log));
16363 		log.u_bbr.inhpts = tcp_in_hpts(rack->rc_tp);
16364 		if (rack->rack_no_prr == 0)
16365 			log.u_bbr.flex1 = rack->r_ctl.rc_prr_sndcnt;
16366 		else
16367 			log.u_bbr.flex1 = 0;
16368 		log.u_bbr.use_lt_bw = rack->r_ent_rec_ns;
16369 		log.u_bbr.use_lt_bw <<= 1;
16370 		log.u_bbr.use_lt_bw |= rack->r_might_revert;
16371 		log.u_bbr.flex2 = rack->r_ctl.rc_num_maps_alloced;
16372 		log.u_bbr.bbr_state = rack->rc_free_cnt;
16373 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
16374 		log.u_bbr.pkts_out = rack->rc_tp->t_maxseg;
16375 		log.u_bbr.flex3 = m->m_flags;
16376 		log.u_bbr.flex4 = rack->r_ctl.rc_hpts_flags;
16377 		log.u_bbr.lost = thflags;
16378 		log.u_bbr.pacing_gain = 0x1;
16379 #ifdef TCP_ACCOUNTING
16380 		log.u_bbr.cwnd_gain = ack_val_set;
16381 #endif
16382 		log.u_bbr.flex7 = 2;
16383 		if (m->m_flags & M_TSTMP) {
16384 			/* Record the hardware timestamp if present */
16385 			mbuf_tstmp2timespec(m, &ts);
16386 			ltv.tv_sec = ts.tv_sec;
16387 			ltv.tv_usec = ts.tv_nsec / 1000;
16388 			log.u_bbr.lt_epoch = tcp_tv_to_usec(&ltv);
16389 		} else if (m->m_flags & M_TSTMP_LRO) {
16390 			/* Record the LRO the arrival timestamp */
16391 			mbuf_tstmp2timespec(m, &ts);
16392 			ltv.tv_sec = ts.tv_sec;
16393 			ltv.tv_usec = ts.tv_nsec / 1000;
16394 			log.u_bbr.flex5 = tcp_tv_to_usec(&ltv);
16395 		}
16396 		log.u_bbr.timeStamp = tcp_get_usecs(&ltv);
16397 		/* Log the rcv time */
16398 		log.u_bbr.delRate = m->m_pkthdr.rcv_tstmp;
16399 #ifdef TCP_REQUEST_TRK
16400 		log.u_bbr.applimited = tp->t_tcpreq_closed;
16401 		log.u_bbr.applimited <<= 8;
16402 		log.u_bbr.applimited |= tp->t_tcpreq_open;
16403 		log.u_bbr.applimited <<= 8;
16404 		log.u_bbr.applimited |= tp->t_tcpreq_req;
16405 		if (tcp_req) {
16406 			/* Copy out any client req info */
16407 			/* seconds */
16408 			log.u_bbr.pkt_epoch = (tcp_req->localtime / HPTS_USEC_IN_SEC);
16409 			/* useconds */
16410 			log.u_bbr.delivered = (tcp_req->localtime % HPTS_USEC_IN_SEC);
16411 			log.u_bbr.rttProp = tcp_req->timestamp;
16412 			log.u_bbr.cur_del_rate = tcp_req->start;
16413 			if (tcp_req->flags & TCP_TRK_TRACK_FLG_OPEN) {
16414 				log.u_bbr.flex8 |= 1;
16415 			} else {
16416 				log.u_bbr.flex8 |= 2;
16417 				log.u_bbr.bw_inuse = tcp_req->end;
16418 			}
16419 			log.u_bbr.flex6 = tcp_req->start_seq;
16420 			if (tcp_req->flags & TCP_TRK_TRACK_FLG_COMP) {
16421 				log.u_bbr.flex8 |= 4;
16422 				log.u_bbr.epoch = tcp_req->end_seq;
16423 			}
16424 		}
16425 #endif
16426 		TCP_LOG_EVENTP(tp, th, &so->so_rcv, &so->so_snd, TCP_LOG_IN, 0,
16427 		    tlen, &log, true, &ltv);
16428 	}
16429 	/* Remove ack required flag if set, we have one  */
16430 	if (thflags & TH_ACK)
16431 		rack->rc_ack_required = 0;
16432 	rack_log_type_bbrsnd(rack, 0, 0, cts, tv, __LINE__);
16433 	if ((thflags & TH_SYN) && (thflags & TH_FIN) && V_drop_synfin) {
16434 		way_out = 4;
16435 		retval = 0;
16436 		m_freem(m);
16437 		goto done_with_input;
16438 	}
16439 	/*
16440 	 * If a segment with the ACK-bit set arrives in the SYN-SENT state
16441 	 * check SEQ.ACK first as described on page 66 of RFC 793, section 3.9.
16442 	 */
16443 	if ((tp->t_state == TCPS_SYN_SENT) && (thflags & TH_ACK) &&
16444 	    (SEQ_LEQ(th->th_ack, tp->iss) || SEQ_GT(th->th_ack, tp->snd_max))) {
16445 		tcp_log_end_status(tp, TCP_EI_STATUS_RST_IN_FRONT);
16446 		ctf_do_dropwithreset(m, tp, th, tlen);
16447 #ifdef TCP_ACCOUNTING
16448 		sched_unpin();
16449 #endif
16450 		return (1);
16451 	}
16452 	/*
16453 	 * If timestamps were negotiated during SYN/ACK and a
16454 	 * segment without a timestamp is received, silently drop
16455 	 * the segment, unless it is a RST segment or missing timestamps are
16456 	 * tolerated.
16457 	 * See section 3.2 of RFC 7323.
16458 	 */
16459 	if ((tp->t_flags & TF_RCVD_TSTMP) && !(to.to_flags & TOF_TS) &&
16460 	    ((thflags & TH_RST) == 0) && (V_tcp_tolerate_missing_ts == 0)) {
16461 		way_out = 5;
16462 		retval = 0;
16463 		m_freem(m);
16464 		goto done_with_input;
16465 	}
16466 	/*
16467 	 * Segment received on connection. Reset idle time and keep-alive
16468 	 * timer. XXX: This should be done after segment validation to
16469 	 * ignore broken/spoofed segs.
16470 	 */
16471 	if  (tp->t_idle_reduce &&
16472 	     (tp->snd_max == tp->snd_una) &&
16473 	     (TICKS_2_USEC(ticks - tp->t_rcvtime) >= tp->t_rxtcur)) {
16474 		counter_u64_add(rack_input_idle_reduces, 1);
16475 		rack_cc_after_idle(rack, tp);
16476 	}
16477 	tp->t_rcvtime = ticks;
16478 #ifdef STATS
16479 	stats_voi_update_abs_ulong(tp->t_stats, VOI_TCP_FRWIN, tiwin);
16480 #endif
16481 	if (tiwin > rack->r_ctl.rc_high_rwnd)
16482 		rack->r_ctl.rc_high_rwnd = tiwin;
16483 	/*
16484 	 * TCP ECN processing. XXXJTL: If we ever use ECN, we need to move
16485 	 * this to occur after we've validated the segment.
16486 	 */
16487 	if (tcp_ecn_input_segment(tp, thflags, tlen,
16488 	    tcp_packets_this_ack(tp, th->th_ack),
16489 	    iptos))
16490 		rack_cong_signal(tp, CC_ECN, th->th_ack, __LINE__);
16491 
16492 	/*
16493 	 * If echoed timestamp is later than the current time, fall back to
16494 	 * non RFC1323 RTT calculation.  Normalize timestamp if syncookies
16495 	 * were used when this connection was established.
16496 	 */
16497 	if ((to.to_flags & TOF_TS) && (to.to_tsecr != 0)) {
16498 		to.to_tsecr -= tp->ts_offset;
16499 		if (TSTMP_GT(to.to_tsecr, ms_cts))
16500 			to.to_tsecr = 0;
16501 	}
16502 	if ((rack->r_rcvpath_rtt_up == 1) &&
16503 	    (to.to_flags & TOF_TS) &&
16504 	    (TSTMP_GEQ(to.to_tsecr, rack->r_ctl.last_rcv_tstmp_for_rtt))) {
16505 		uint32_t rtt = 0;
16506 
16507 		/*
16508 		 * We are receiving only and thus not sending
16509 		 * data to do an RTT. We set a flag when we first
16510 		 * sent this TS to the peer. We now have it back
16511 		 * and have an RTT to share. We log it as a conf
16512 		 * 4, we are not so sure about it.. since we
16513 		 * may have lost an ack.
16514 		 */
16515 		if (TSTMP_GT(cts, rack->r_ctl.last_time_of_arm_rcv))
16516 		    rtt = (cts - rack->r_ctl.last_time_of_arm_rcv);
16517 		rack->r_rcvpath_rtt_up = 0;
16518 		/* Submit and commit the timer */
16519 		if (rtt > 0) {
16520 			tcp_rack_xmit_timer(rack, rtt, 0, rtt, 4, NULL, 1);
16521 			tcp_rack_xmit_timer_commit(rack, tp);
16522 		}
16523 	}
16524 	/*
16525 	 * If its the first time in we need to take care of options and
16526 	 * verify we can do SACK for rack!
16527 	 */
16528 	if (rack->r_state == 0) {
16529 		/* Should be init'd by rack_init() */
16530 		KASSERT(rack->rc_inp != NULL,
16531 		    ("%s: rack->rc_inp unexpectedly NULL", __func__));
16532 		if (rack->rc_inp == NULL) {
16533 			rack->rc_inp = inp;
16534 		}
16535 
16536 		/*
16537 		 * Process options only when we get SYN/ACK back. The SYN
16538 		 * case for incoming connections is handled in tcp_syncache.
16539 		 * According to RFC1323 the window field in a SYN (i.e., a
16540 		 * <SYN> or <SYN,ACK>) segment itself is never scaled. XXX
16541 		 * this is traditional behavior, may need to be cleaned up.
16542 		 */
16543 		if (tp->t_state == TCPS_SYN_SENT && (thflags & TH_SYN)) {
16544 			/* Handle parallel SYN for ECN */
16545 			tcp_ecn_input_parallel_syn(tp, thflags, iptos);
16546 			if ((to.to_flags & TOF_SCALE) &&
16547 			    (tp->t_flags & TF_REQ_SCALE)) {
16548 				tp->t_flags |= TF_RCVD_SCALE;
16549 				tp->snd_scale = to.to_wscale;
16550 			} else
16551 				tp->t_flags &= ~TF_REQ_SCALE;
16552 			/*
16553 			 * Initial send window.  It will be updated with the
16554 			 * next incoming segment to the scaled value.
16555 			 */
16556 			tp->snd_wnd = th->th_win;
16557 			rack_validate_fo_sendwin_up(tp, rack);
16558 			if ((to.to_flags & TOF_TS) &&
16559 			    (tp->t_flags & TF_REQ_TSTMP)) {
16560 				tp->t_flags |= TF_RCVD_TSTMP;
16561 				tp->ts_recent = to.to_tsval;
16562 				tp->ts_recent_age = cts;
16563 			} else
16564 				tp->t_flags &= ~TF_REQ_TSTMP;
16565 			if (to.to_flags & TOF_MSS) {
16566 				tcp_mss(tp, to.to_mss);
16567 			}
16568 			if ((tp->t_flags & TF_SACK_PERMIT) &&
16569 			    (to.to_flags & TOF_SACKPERM) == 0)
16570 				tp->t_flags &= ~TF_SACK_PERMIT;
16571 			if (tp->t_flags & TF_FASTOPEN) {
16572 				if (to.to_flags & TOF_FASTOPEN) {
16573 					uint16_t mss;
16574 
16575 					if (to.to_flags & TOF_MSS)
16576 						mss = to.to_mss;
16577 					else
16578 						if ((inp->inp_vflag & INP_IPV6) != 0)
16579 							mss = TCP6_MSS;
16580 						else
16581 							mss = TCP_MSS;
16582 					tcp_fastopen_update_cache(tp, mss,
16583 					    to.to_tfo_len, to.to_tfo_cookie);
16584 				} else
16585 					tcp_fastopen_disable_path(tp);
16586 			}
16587 		}
16588 		/*
16589 		 * At this point we are at the initial call. Here we decide
16590 		 * if we are doing RACK or not. We do this by seeing if
16591 		 * TF_SACK_PERMIT is set and the sack-not-required is clear.
16592 		 * The code now does do dup-ack counting so if you don't
16593 		 * switch back you won't get rack & TLP, but you will still
16594 		 * get this stack.
16595 		 */
16596 
16597 		if ((rack_sack_not_required == 0) &&
16598 		    ((tp->t_flags & TF_SACK_PERMIT) == 0)) {
16599 			tcp_switch_back_to_default(tp);
16600 			(*tp->t_fb->tfb_tcp_do_segment)(tp, m, th, drop_hdrlen,
16601 			    tlen, iptos);
16602 #ifdef TCP_ACCOUNTING
16603 			sched_unpin();
16604 #endif
16605 			return (1);
16606 		}
16607 		tcp_set_hpts(tp);
16608 		sack_filter_clear(&rack->r_ctl.rack_sf, th->th_ack);
16609 	}
16610 	if (thflags & TH_FIN)
16611 		tcp_log_end_status(tp, TCP_EI_STATUS_CLIENT_FIN);
16612 	us_cts = tcp_tv_to_usec(&rack->r_ctl.act_rcv_time);
16613 	if ((rack->rc_gp_dyn_mul) &&
16614 	    (rack->use_fixed_rate == 0) &&
16615 	    (rack->rc_always_pace)) {
16616 		/* Check in on probertt */
16617 		rack_check_probe_rtt(rack, cts);
16618 	}
16619 	rack_clear_rate_sample(rack);
16620 	if ((rack->forced_ack) &&
16621 	    ((tcp_get_flags(th) & TH_RST) == 0)) {
16622 		rack_handle_probe_response(rack, tiwin, us_cts);
16623 	}
16624 	/*
16625 	 * This is the one exception case where we set the rack state
16626 	 * always. All other times (timers etc) we must have a rack-state
16627 	 * set (so we assure we have done the checks above for SACK).
16628 	 */
16629 	rack->r_ctl.rc_rcvtime = cts;
16630 	if (rack->r_state != tp->t_state)
16631 		rack_set_state(tp, rack);
16632 	if (SEQ_GT(th->th_ack, tp->snd_una) &&
16633 	    (rsm = tqhash_min(rack->r_ctl.tqh)) != NULL)
16634 		kern_prefetch(rsm, &prev_state);
16635 	prev_state = rack->r_state;
16636 	if ((thflags & TH_RST) &&
16637 	    ((SEQ_GEQ(th->th_seq, tp->last_ack_sent) &&
16638 	      SEQ_LT(th->th_seq, tp->last_ack_sent + tp->rcv_wnd)) ||
16639 	     (tp->rcv_wnd == 0 && tp->last_ack_sent == th->th_seq))) {
16640 		/* The connection will be killed by a reset check the tracepoint */
16641 		tcp_trace_point(rack->rc_tp, TCP_TP_RESET_RCV);
16642 	}
16643 	retval = (*rack->r_substate) (m, th, so,
16644 	    tp, &to, drop_hdrlen,
16645 	    tlen, tiwin, thflags, nxt_pkt, iptos);
16646 	if (retval == 0) {
16647 		/*
16648 		 * If retval is 1 the tcb is unlocked and most likely the tp
16649 		 * is gone.
16650 		 */
16651 		INP_WLOCK_ASSERT(inp);
16652 		if ((rack->rc_gp_dyn_mul) &&
16653 		    (rack->rc_always_pace) &&
16654 		    (rack->use_fixed_rate == 0) &&
16655 		    rack->in_probe_rtt &&
16656 		    (rack->r_ctl.rc_time_probertt_starts == 0)) {
16657 			/*
16658 			 * If we are going for target, lets recheck before
16659 			 * we output.
16660 			 */
16661 			rack_check_probe_rtt(rack, cts);
16662 		}
16663 		if (rack->set_pacing_done_a_iw == 0) {
16664 			/* How much has been acked? */
16665 			if ((tp->snd_una - tp->iss) > (ctf_fixed_maxseg(tp) * 10)) {
16666 				/* We have enough to set in the pacing segment size */
16667 				rack->set_pacing_done_a_iw = 1;
16668 				rack_set_pace_segments(tp, rack, __LINE__, NULL);
16669 			}
16670 		}
16671 		tcp_rack_xmit_timer_commit(rack, tp);
16672 #ifdef TCP_ACCOUNTING
16673 		/*
16674 		 * If we set the ack_val_se to what ack processing we are doing
16675 		 * we also want to track how many cycles we burned. Note
16676 		 * the bits after tcp_output we let be "free". This is because
16677 		 * we are also tracking the tcp_output times as well. Note the
16678 		 * use of 0xf here since we only have 11 counter (0 - 0xa) and
16679 		 * 0xf cannot be returned and is what we initialize it too to
16680 		 * indicate we are not doing the tabulations.
16681 		 */
16682 		if (ack_val_set != 0xf) {
16683 			uint64_t crtsc;
16684 
16685 			crtsc = get_cyclecount();
16686 			if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
16687 				tp->tcp_proc_time[ack_val_set] += (crtsc - ts_val);
16688 			}
16689 		}
16690 #endif
16691 		if ((nxt_pkt == 0) && (no_output == 0)) {
16692 			if ((rack->r_wanted_output != 0) ||
16693 			    (tp->t_flags & TF_ACKNOW) ||
16694 			    (rack->r_fast_output != 0)) {
16695 
16696 do_output_now:
16697 				if (tcp_output(tp) < 0) {
16698 #ifdef TCP_ACCOUNTING
16699 					sched_unpin();
16700 #endif
16701 					return (1);
16702 				}
16703 				did_out = 1;
16704 			}
16705 			rack_start_hpts_timer(rack, tp, cts, 0, 0, 0);
16706 			rack_free_trim(rack);
16707 		} else if ((nxt_pkt == 0) && (tp->t_flags & TF_ACKNOW)) {
16708 			goto do_output_now;
16709 		} else if ((no_output == 1) &&
16710 			   (nxt_pkt == 0) &&
16711 			   (tcp_in_hpts(rack->rc_tp) == 0)) {
16712 			/*
16713 			 * We are not in hpts and we had a pacing timer up. Use
16714 			 * the remaining time (time_remaining) to restart the timer.
16715 			 */
16716 			KASSERT ((time_remaining != 0), ("slot remaining is zero for rack:%p tp:%p", rack, tp));
16717 			rack_start_hpts_timer(rack, tp, cts, time_remaining, 0, 0);
16718 			rack_free_trim(rack);
16719 		}
16720 		/* Clear the flag, it may have been cleared by output but we may not have  */
16721 		if ((nxt_pkt == 0) && (tp->t_flags2 & TF2_HPTS_CALLS))
16722 			tp->t_flags2 &= ~TF2_HPTS_CALLS;
16723 		/*
16724 		 * The draft (v3) calls for us to use SEQ_GEQ, but that
16725 		 * causes issues when we are just going app limited. Lets
16726 		 * instead use SEQ_GT <or> where its equal but more data
16727 		 * is outstanding.
16728 		 *
16729 		 * Also make sure we are on the last ack of a series. We
16730 		 * have to have all the ack's processed in queue to know
16731 		 * if there is something left outstanding.
16732 		 */
16733 		if (SEQ_GEQ(tp->snd_una, rack->r_ctl.roundends) &&
16734 		    (rack->rc_new_rnd_needed == 0) &&
16735 		    (nxt_pkt == 0)) {
16736 			/*
16737 			 * We have crossed into a new round with
16738 			 * the new snd_unae.
16739 			 */
16740 			rack_new_round_setup(tp, rack, tp->snd_una);
16741 		}
16742 		if ((nxt_pkt == 0) &&
16743 		    ((rack->r_ctl.rc_hpts_flags & PACE_TMR_MASK) == 0) &&
16744 		    (SEQ_GT(tp->snd_max, tp->snd_una) ||
16745 		     (tp->t_flags & TF_DELACK) ||
16746 		     ((V_tcp_always_keepalive || rack->rc_inp->inp_socket->so_options & SO_KEEPALIVE) &&
16747 		      (tp->t_state <= TCPS_CLOSING)))) {
16748 			/* We could not send (probably in the hpts but stopped the timer earlier)? */
16749 			if ((tp->snd_max == tp->snd_una) &&
16750 			    ((tp->t_flags & TF_DELACK) == 0) &&
16751 			    (tcp_in_hpts(rack->rc_tp)) &&
16752 			    (rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT)) {
16753 				/* keep alive not needed if we are hptsi output yet */
16754 				;
16755 			} else {
16756 				int late = 0;
16757 				if (tcp_in_hpts(tp)) {
16758 					if (rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT) {
16759 						us_cts = tcp_get_usecs(NULL);
16760 						if (TSTMP_GT(rack->r_ctl.rc_last_output_to, us_cts)) {
16761 							rack->r_early = 1;
16762 							rack->r_ctl.rc_agg_early += (rack->r_ctl.rc_last_output_to - us_cts);
16763 						} else
16764 							late = 1;
16765 						rack->r_ctl.rc_hpts_flags &= ~PACE_PKT_OUTPUT;
16766 					}
16767 					tcp_hpts_remove(tp);
16768 				}
16769 				if (late && (did_out == 0)) {
16770 					/*
16771 					 * We are late in the sending
16772 					 * and we did not call the output
16773 					 * (this probably should not happen).
16774 					 */
16775 					goto do_output_now;
16776 				}
16777 				rack_start_hpts_timer(rack, tp, tcp_get_usecs(NULL), 0, 0, 0);
16778 			}
16779 			way_out = 1;
16780 		} else if (nxt_pkt == 0) {
16781 			/* Do we have the correct timer running? */
16782 			rack_timer_audit(tp, rack, &so->so_snd);
16783 			way_out = 2;
16784 		}
16785 	done_with_input:
16786 		rack_log_doseg_done(rack, cts, nxt_pkt, did_out, way_out, max(1, nsegs));
16787 		if (did_out)
16788 			rack->r_wanted_output = 0;
16789 	}
16790 
16791 #ifdef TCP_ACCOUNTING
16792 	sched_unpin();
16793 #endif
16794 	return (retval);
16795 }
16796 
16797 static void
16798 rack_do_segment(struct tcpcb *tp, struct mbuf *m, struct tcphdr *th,
16799     int32_t drop_hdrlen, int32_t tlen, uint8_t iptos)
16800 {
16801 	struct timeval tv;
16802 
16803 	/* First lets see if we have old packets */
16804 	if (!STAILQ_EMPTY(&tp->t_inqueue)) {
16805 		if (ctf_do_queued_segments(tp, 1)) {
16806 			m_freem(m);
16807 			return;
16808 		}
16809 	}
16810 	if (m->m_flags & M_TSTMP_LRO) {
16811 		mbuf_tstmp2timeval(m, &tv);
16812 	} else {
16813 		/* Should not be should we kassert instead? */
16814 		tcp_get_usecs(&tv);
16815 	}
16816 	if (rack_do_segment_nounlock(tp, m, th, drop_hdrlen, tlen, iptos, 0,
16817 	    &tv) == 0) {
16818 		INP_WUNLOCK(tptoinpcb(tp));
16819 	}
16820 }
16821 
16822 struct rack_sendmap *
16823 tcp_rack_output(struct tcpcb *tp, struct tcp_rack *rack, uint32_t tsused)
16824 {
16825 	struct rack_sendmap *rsm = NULL;
16826 	int32_t idx;
16827 	uint32_t srtt = 0, thresh = 0, ts_low = 0;
16828 
16829 	/* Return the next guy to be re-transmitted */
16830 	if (tqhash_empty(rack->r_ctl.tqh)) {
16831 		return (NULL);
16832 	}
16833 	if (tp->t_flags & TF_SENTFIN) {
16834 		/* retran the end FIN? */
16835 		return (NULL);
16836 	}
16837 	/* ok lets look at this one */
16838 	rsm = TAILQ_FIRST(&rack->r_ctl.rc_tmap);
16839 	if (rack->r_must_retran && rsm && (rsm->r_flags & RACK_MUST_RXT)) {
16840 		return (rsm);
16841 	}
16842 	if (rsm && ((rsm->r_flags & RACK_ACKED) == 0)) {
16843 		goto check_it;
16844 	}
16845 	rsm = rack_find_lowest_rsm(rack);
16846 	if (rsm == NULL) {
16847 		return (NULL);
16848 	}
16849 check_it:
16850 	if (((rack->rc_tp->t_flags & TF_SACK_PERMIT) == 0) &&
16851 	    (rsm->r_dupack >= DUP_ACK_THRESHOLD)) {
16852 		/*
16853 		 * No sack so we automatically do the 3 strikes and
16854 		 * retransmit (no rack timer would be started).
16855 		 */
16856 		return (rsm);
16857 	}
16858 	if (rsm->r_flags & RACK_ACKED) {
16859 		return (NULL);
16860 	}
16861 	if (((rsm->r_flags & RACK_SACK_PASSED) == 0) &&
16862 	    (rsm->r_dupack < DUP_ACK_THRESHOLD)) {
16863 		/* Its not yet ready */
16864 		return (NULL);
16865 	}
16866 	srtt = rack_grab_rtt(tp, rack);
16867 	idx = rsm->r_rtr_cnt - 1;
16868 	ts_low = (uint32_t)rsm->r_tim_lastsent[idx];
16869 	thresh = rack_calc_thresh_rack(rack, srtt, tsused, __LINE__, 1);
16870 	if ((tsused == ts_low) ||
16871 	    (TSTMP_LT(tsused, ts_low))) {
16872 		/* No time since sending */
16873 		return (NULL);
16874 	}
16875 	if ((tsused - ts_low) < thresh) {
16876 		/* It has not been long enough yet */
16877 		return (NULL);
16878 	}
16879 	if ((rsm->r_dupack >= DUP_ACK_THRESHOLD) ||
16880 	    ((rsm->r_flags & RACK_SACK_PASSED))) {
16881 		/*
16882 		 * We have passed the dup-ack threshold <or>
16883 		 * a SACK has indicated this is missing.
16884 		 * Note that if you are a declared attacker
16885 		 * it is only the dup-ack threshold that
16886 		 * will cause retransmits.
16887 		 */
16888 		/* log retransmit reason */
16889 		rack_log_retran_reason(rack, rsm, (tsused - ts_low), thresh, 1);
16890 		rack->r_fast_output = 0;
16891 		return (rsm);
16892 	}
16893 	return (NULL);
16894 }
16895 
16896 static void
16897 rack_log_pacing_delay_calc (struct tcp_rack *rack, uint32_t len, uint32_t pacing_delay,
16898 			   uint64_t bw_est, uint64_t bw, uint64_t len_time, int method,
16899 			   int line, struct rack_sendmap *rsm, uint8_t quality)
16900 {
16901 	if (tcp_bblogging_on(rack->rc_tp)) {
16902 		union tcp_log_stackspecific log;
16903 		struct timeval tv;
16904 
16905 		if (rack_verbose_logging == 0) {
16906 			/*
16907 			 * We are not verbose screen out all but
16908 			 * ones we always want.
16909 			 */
16910 			if ((method != 2) &&
16911 			    (method != 3) &&
16912 			    (method != 7) &&
16913 			    (method != 89) &&
16914 			    (method != 14) &&
16915 			    (method != 20)) {
16916 				return;
16917 			}
16918 		}
16919 		memset(&log, 0, sizeof(log));
16920 		log.u_bbr.flex1 = pacing_delay;
16921 		log.u_bbr.flex2 = len;
16922 		log.u_bbr.flex3 = rack->r_ctl.rc_pace_min_segs;
16923 		log.u_bbr.flex4 = rack->r_ctl.rc_pace_max_segs;
16924 		log.u_bbr.flex5 = rack->r_ctl.rack_per_of_gp_ss;
16925 		log.u_bbr.flex6 = rack->r_ctl.rack_per_of_gp_ca;
16926 		log.u_bbr.use_lt_bw = rack->rc_ack_can_sendout_data;
16927 		log.u_bbr.use_lt_bw <<= 1;
16928 		log.u_bbr.use_lt_bw |= rack->r_late;
16929 		log.u_bbr.use_lt_bw <<= 1;
16930 		log.u_bbr.use_lt_bw |= rack->r_early;
16931 		log.u_bbr.use_lt_bw <<= 1;
16932 		log.u_bbr.use_lt_bw |= rack->app_limited_needs_set;
16933 		log.u_bbr.use_lt_bw <<= 1;
16934 		log.u_bbr.use_lt_bw |= rack->rc_gp_filled;
16935 		log.u_bbr.use_lt_bw <<= 1;
16936 		log.u_bbr.use_lt_bw |= rack->measure_saw_probe_rtt;
16937 		log.u_bbr.use_lt_bw <<= 1;
16938 		log.u_bbr.use_lt_bw |= rack->in_probe_rtt;
16939 		log.u_bbr.use_lt_bw <<= 1;
16940 		log.u_bbr.use_lt_bw |= rack->gp_ready;
16941 		log.u_bbr.pkt_epoch = line;
16942 		log.u_bbr.epoch = rack->r_ctl.rc_agg_delayed;
16943 		log.u_bbr.lt_epoch = rack->r_ctl.rc_agg_early;
16944 		log.u_bbr.applimited = rack->r_ctl.rack_per_of_gp_rec;
16945 		log.u_bbr.bw_inuse = bw_est;
16946 		log.u_bbr.delRate = bw;
16947 		if (rack->r_ctl.gp_bw == 0)
16948 			log.u_bbr.cur_del_rate = 0;
16949 		else
16950 			log.u_bbr.cur_del_rate = rack_get_bw(rack);
16951 		log.u_bbr.rttProp = len_time;
16952 		log.u_bbr.pkts_out = rack->r_ctl.rc_rack_min_rtt;
16953 		log.u_bbr.lost = rack->r_ctl.rc_probertt_sndmax_atexit;
16954 		log.u_bbr.pacing_gain = rack_get_output_gain(rack, rsm);
16955 		if (rack->r_ctl.cwnd_to_use < rack->rc_tp->snd_ssthresh) {
16956 			/* We are in slow start */
16957 			log.u_bbr.flex7 = 1;
16958 		} else {
16959 			/* we are on congestion avoidance */
16960 			log.u_bbr.flex7 = 0;
16961 		}
16962 		log.u_bbr.flex8 = method;
16963 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
16964 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
16965 		log.u_bbr.cwnd_gain = rack->rc_gp_saw_rec;
16966 		log.u_bbr.cwnd_gain <<= 1;
16967 		log.u_bbr.cwnd_gain |= rack->rc_gp_saw_ss;
16968 		log.u_bbr.cwnd_gain <<= 1;
16969 		log.u_bbr.cwnd_gain |= rack->rc_gp_saw_ca;
16970 		log.u_bbr.cwnd_gain <<= 1;
16971 		log.u_bbr.cwnd_gain |= rack->use_fixed_rate;
16972 		log.u_bbr.cwnd_gain <<= 1;
16973 		log.u_bbr.cwnd_gain |= rack->rc_always_pace;
16974 		log.u_bbr.cwnd_gain <<= 1;
16975 		log.u_bbr.cwnd_gain |= rack->gp_ready;
16976 		log.u_bbr.bbr_substate = quality;
16977 		log.u_bbr.bbr_state = rack->dgp_on;
16978 		log.u_bbr.bbr_state <<= 1;
16979 		log.u_bbr.bbr_state |= rack->rc_pace_to_cwnd;
16980 		log.u_bbr.bbr_state <<= 2;
16981 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
16982 		    &rack->rc_inp->inp_socket->so_rcv,
16983 		    &rack->rc_inp->inp_socket->so_snd,
16984 		    BBR_LOG_HPTSI_CALC, 0,
16985 		    0, &log, false, &tv);
16986 	}
16987 }
16988 
16989 static uint32_t
16990 rack_get_pacing_len(struct tcp_rack *rack, uint64_t bw, uint32_t mss)
16991 {
16992 	uint32_t new_tso, user_max, pace_one;
16993 
16994 	user_max = rack->rc_user_set_max_segs * mss;
16995 	if (rack->rc_force_max_seg) {
16996 		return (user_max);
16997 	}
16998 	if (rack->use_fixed_rate &&
16999 	    ((rack->r_ctl.crte == NULL) ||
17000 	     (bw != rack->r_ctl.crte->rate))) {
17001 		/* Use the user mss since we are not exactly matched */
17002 		return (user_max);
17003 	}
17004 	if (rack_pace_one_seg ||
17005 	    (rack->r_ctl.rc_user_set_min_segs == 1))
17006 		pace_one = 1;
17007 	else
17008 		pace_one = 0;
17009 
17010 	new_tso = tcp_get_pacing_burst_size_w_divisor(rack->rc_tp, bw, mss,
17011 		     pace_one, rack->r_ctl.crte, NULL, rack->r_ctl.pace_len_divisor);
17012 	if (new_tso > user_max)
17013 		new_tso = user_max;
17014 	if (rack->rc_hybrid_mode && rack->r_ctl.client_suggested_maxseg) {
17015 		if (((uint32_t)rack->r_ctl.client_suggested_maxseg * mss) > new_tso)
17016 			new_tso = (uint32_t)rack->r_ctl.client_suggested_maxseg * mss;
17017 	}
17018 	if (rack->r_ctl.rc_user_set_min_segs &&
17019 	    ((rack->r_ctl.rc_user_set_min_segs * mss) > new_tso))
17020 	    new_tso = rack->r_ctl.rc_user_set_min_segs * mss;
17021 	return (new_tso);
17022 }
17023 
17024 static uint64_t
17025 rack_arrive_at_discounted_rate(struct tcp_rack *rack, uint64_t window_input, uint32_t *rate_set, uint32_t *gain_b)
17026 {
17027 	uint64_t reduced_win;
17028 	uint32_t gain;
17029 
17030 	if (window_input < rc_init_window(rack)) {
17031 		/*
17032 		 * The cwnd is collapsed to
17033 		 * nearly zero, maybe because of a time-out?
17034 		 * Lets drop back to the lt-bw.
17035 		 */
17036 		reduced_win = rack_get_lt_bw(rack);
17037 		/* Set the flag so the caller knows its a rate and not a reduced window */
17038 		*rate_set = 1;
17039 		gain = 100;
17040 	} else if  (IN_RECOVERY(rack->rc_tp->t_flags)) {
17041 		/*
17042 		 * If we are in recover our cwnd needs to be less for
17043 		 * our pacing consideration.
17044 		 */
17045 		if (rack->rack_hibeta == 0) {
17046 			reduced_win = window_input / 2;
17047 			gain = 50;
17048 		} else {
17049 			reduced_win = window_input * rack->r_ctl.saved_hibeta;
17050 			reduced_win /= 100;
17051 			gain = rack->r_ctl.saved_hibeta;
17052 		}
17053 	} else {
17054 		/*
17055 		 * Apply Timely factor to increase/decrease the
17056 		 * amount we are pacing at.
17057 		 */
17058 		gain = rack_get_output_gain(rack, NULL);
17059 		if (gain > rack_gain_p5_ub) {
17060 			gain = rack_gain_p5_ub;
17061 		}
17062 		reduced_win = window_input * gain;
17063 		reduced_win /= 100;
17064 	}
17065 	if (gain_b != NULL)
17066 		*gain_b = gain;
17067 	/*
17068 	 * What is being returned here is a trimmed down
17069 	 * window values in all cases where rate_set is left
17070 	 * at 0. In one case we actually return the rate (lt_bw).
17071 	 * the "reduced_win" is returned as a slimmed down cwnd that
17072 	 * is then calculated by the caller into a rate when rate_set
17073 	 * is 0.
17074 	 */
17075 	return (reduced_win);
17076 }
17077 
17078 static int32_t
17079 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)
17080 {
17081 	uint64_t lentim, fill_bw;
17082 
17083 	rack->r_via_fill_cw = 0;
17084 	if (ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked) > rack->r_ctl.cwnd_to_use)
17085 		return (pacing_delay);
17086 	if ((ctf_outstanding(rack->rc_tp) + (segsiz-1)) > rack->rc_tp->snd_wnd)
17087 		return (pacing_delay);
17088 	if (rack->r_ctl.rc_last_us_rtt == 0)
17089 		return (pacing_delay);
17090 	if (rack->rc_pace_fill_if_rttin_range &&
17091 	    (rack->r_ctl.rc_last_us_rtt >=
17092 	     (get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt) * rack->rtt_limit_mul))) {
17093 		/* The rtt is huge, N * smallest, lets not fill */
17094 		return (pacing_delay);
17095 	}
17096 	if (rack->r_ctl.fillcw_cap && *rate_wanted >= rack->r_ctl.fillcw_cap)
17097 		return (pacing_delay);
17098 	/*
17099 	 * first lets calculate the b/w based on the last us-rtt
17100 	 * and the the smallest send window.
17101 	 */
17102 	fill_bw = min(rack->rc_tp->snd_cwnd, rack->r_ctl.cwnd_to_use);
17103 	if (rack->rc_fillcw_apply_discount) {
17104 		uint32_t rate_set = 0;
17105 
17106 		fill_bw = rack_arrive_at_discounted_rate(rack, fill_bw, &rate_set, NULL);
17107 		if (rate_set) {
17108 			goto at_lt_bw;
17109 		}
17110 	}
17111 	/* Take the rwnd if its smaller */
17112 	if (fill_bw > rack->rc_tp->snd_wnd)
17113 		fill_bw = rack->rc_tp->snd_wnd;
17114 	/* Now lets make it into a b/w */
17115 	fill_bw *= (uint64_t)HPTS_USEC_IN_SEC;
17116 	fill_bw /= (uint64_t)rack->r_ctl.rc_last_us_rtt;
17117 	/* Adjust to any cap */
17118 	if (rack->r_ctl.fillcw_cap && fill_bw >= rack->r_ctl.fillcw_cap)
17119 		fill_bw = rack->r_ctl.fillcw_cap;
17120 
17121 at_lt_bw:
17122 	if (rack_bw_multipler > 0) {
17123 		/*
17124 		 * We want to limit fill-cw to the some multiplier
17125 		 * of the max(lt_bw, gp_est). The normal default
17126 		 * is 0 for off, so a sysctl has enabled it.
17127 		 */
17128 		uint64_t lt_bw, gp, rate;
17129 
17130 		gp = rack_get_gp_est(rack);
17131 		lt_bw = rack_get_lt_bw(rack);
17132 		if (lt_bw > gp)
17133 			rate = lt_bw;
17134 		else
17135 			rate = gp;
17136 		rate *= rack_bw_multipler;
17137 		rate /= 100;
17138 		if (rack_verbose_logging && tcp_bblogging_on(rack->rc_tp)) {
17139 			union tcp_log_stackspecific log;
17140 			struct timeval tv;
17141 
17142 			memset(&log, 0, sizeof(log));
17143 			log.u_bbr.timeStamp = tcp_get_usecs(&tv);
17144 			log.u_bbr.flex1 = rack_bw_multipler;
17145 			log.u_bbr.flex2 = len;
17146 			log.u_bbr.cur_del_rate = gp;
17147 			log.u_bbr.delRate = lt_bw;
17148 			log.u_bbr.bw_inuse = rate;
17149 			log.u_bbr.rttProp = fill_bw;
17150 			log.u_bbr.flex8 = 44;
17151 			tcp_log_event(rack->rc_tp, NULL, NULL, NULL,
17152 				      BBR_LOG_CWND, 0,
17153 				      0, &log, false, NULL,
17154 				      __func__, __LINE__, &tv);
17155 		}
17156 		if (fill_bw > rate)
17157 			fill_bw = rate;
17158 	}
17159 	/* We are below the min b/w */
17160 	if (non_paced)
17161 		*rate_wanted = fill_bw;
17162 	if ((fill_bw < RACK_MIN_BW) || (fill_bw < *rate_wanted))
17163 		return (pacing_delay);
17164 	rack->r_via_fill_cw = 1;
17165 	if (rack->r_rack_hw_rate_caps &&
17166 	    (rack->r_ctl.crte != NULL)) {
17167 		uint64_t high_rate;
17168 
17169 		high_rate = tcp_hw_highest_rate(rack->r_ctl.crte);
17170 		if (fill_bw > high_rate) {
17171 			/* We are capping bw at the highest rate table entry */
17172 			if (*rate_wanted > high_rate) {
17173 				/* The original rate was also capped */
17174 				rack->r_via_fill_cw = 0;
17175 			}
17176 			rack_log_hdwr_pacing(rack,
17177 					     fill_bw, high_rate, __LINE__,
17178 					     0, 3);
17179 			fill_bw = high_rate;
17180 			if (capped)
17181 				*capped = 1;
17182 		}
17183 	} else if ((rack->r_ctl.crte == NULL) &&
17184 		   (rack->rack_hdrw_pacing == 0) &&
17185 		   (rack->rack_hdw_pace_ena) &&
17186 		   rack->r_rack_hw_rate_caps &&
17187 		   (rack->rack_attempt_hdwr_pace == 0) &&
17188 		   (rack->rc_inp->inp_route.ro_nh != NULL) &&
17189 		   (rack->rc_inp->inp_route.ro_nh->nh_ifp != NULL)) {
17190 		/*
17191 		 * Ok we may have a first attempt that is greater than our top rate
17192 		 * lets check.
17193 		 */
17194 		uint64_t high_rate;
17195 
17196 		high_rate = tcp_hw_highest_rate_ifp(rack->rc_inp->inp_route.ro_nh->nh_ifp, rack->rc_inp);
17197 		if (high_rate) {
17198 			if (fill_bw > high_rate) {
17199 				fill_bw = high_rate;
17200 				if (capped)
17201 					*capped = 1;
17202 			}
17203 		}
17204 	}
17205 	if (rack->r_ctl.bw_rate_cap && (fill_bw > rack->r_ctl.bw_rate_cap)) {
17206 		rack_log_hybrid_bw(rack, rack->rc_tp->snd_max,
17207 				   fill_bw, 0, 0, HYBRID_LOG_RATE_CAP, 2, NULL, __LINE__);
17208 		fill_bw = rack->r_ctl.bw_rate_cap;
17209 	}
17210 	/*
17211 	 * Ok fill_bw holds our mythical b/w to fill the cwnd
17212 	 * in an rtt (unless it was capped), what does that
17213 	 * time wise equate too?
17214 	 */
17215 	lentim = (uint64_t)(len) * (uint64_t)HPTS_USEC_IN_SEC;
17216 	lentim /= fill_bw;
17217 	*rate_wanted = fill_bw;
17218 	if (non_paced || (lentim < pacing_delay)) {
17219 		rack_log_pacing_delay_calc(rack, len, pacing_delay, fill_bw,
17220 					   0, lentim, 12, __LINE__, NULL, 0);
17221 		return ((int32_t)lentim);
17222 	} else
17223 		return (pacing_delay);
17224 }
17225 
17226 static int32_t
17227 rack_get_pacing_delay(struct tcp_rack *rack, struct tcpcb *tp, uint32_t len, struct rack_sendmap *rsm, uint32_t segsiz, int line)
17228 {
17229 	uint64_t srtt;
17230 	int32_t pacing_delay = 0;
17231 	int can_start_hw_pacing = 1;
17232 	int err;
17233 	int pace_one;
17234 
17235 	if (rack_pace_one_seg ||
17236 	    (rack->r_ctl.rc_user_set_min_segs == 1))
17237 		pace_one = 1;
17238 	else
17239 		pace_one = 0;
17240 	if (rack->rc_always_pace == 0) {
17241 		/*
17242 		 * We use the most optimistic possible cwnd/srtt for
17243 		 * sending calculations. This will make our
17244 		 * calculation anticipate getting more through
17245 		 * quicker then possible. But thats ok we don't want
17246 		 * the peer to have a gap in data sending.
17247 		 */
17248 		uint64_t cwnd, tr_perms = 0;
17249 		int32_t reduce;
17250 
17251 	old_method:
17252 		/*
17253 		 * We keep no precise pacing with the old method
17254 		 * instead we use the pacer to mitigate bursts.
17255 		 */
17256 		if (rack->r_ctl.rc_rack_min_rtt)
17257 			srtt = rack->r_ctl.rc_rack_min_rtt;
17258 		else
17259 			srtt = max(tp->t_srtt, 1);
17260 		if (rack->r_ctl.rc_rack_largest_cwnd)
17261 			cwnd = rack->r_ctl.rc_rack_largest_cwnd;
17262 		else
17263 			cwnd = rack->r_ctl.cwnd_to_use;
17264 		/* Inflate cwnd by 1000 so srtt of usecs is in ms */
17265 		tr_perms = (cwnd * 1000) / srtt;
17266 		if (tr_perms == 0) {
17267 			tr_perms = ctf_fixed_maxseg(tp);
17268 		}
17269 		/*
17270 		 * Calculate how long this will take to drain, if
17271 		 * the calculation comes out to zero, thats ok we
17272 		 * will use send_a_lot to possibly spin around for
17273 		 * more increasing tot_len_this_send to the point
17274 		 * that its going to require a pace, or we hit the
17275 		 * cwnd. Which in that case we are just waiting for
17276 		 * a ACK.
17277 		 */
17278 		pacing_delay = len / tr_perms;
17279 		/* Now do we reduce the time so we don't run dry? */
17280 		if (pacing_delay && rack_pacing_delay_reduction) {
17281 			reduce = (pacing_delay / rack_pacing_delay_reduction);
17282 			if (reduce < pacing_delay) {
17283 				pacing_delay -= reduce;
17284 			} else
17285 				pacing_delay = 0;
17286 		} else
17287 			reduce = 0;
17288 		pacing_delay *= HPTS_USEC_IN_MSEC;
17289 		if (rack->rc_pace_to_cwnd) {
17290 			uint64_t rate_wanted = 0;
17291 
17292 			pacing_delay = pace_to_fill_cwnd(rack, pacing_delay, len, segsiz, NULL, &rate_wanted, 1);
17293 			rack->rc_ack_can_sendout_data = 1;
17294 			rack_log_pacing_delay_calc(rack, len, pacing_delay, rate_wanted, 0, 0, 14, __LINE__, NULL, 0);
17295 		} else
17296 			rack_log_pacing_delay_calc(rack, len, pacing_delay, tr_perms, reduce, 0, 7, __LINE__, NULL, 0);
17297 		/*******************************************************/
17298 		/* RRS: We insert non-paced call to stats here for len */
17299 		/*******************************************************/
17300 	} else {
17301 		uint64_t bw_est, res, lentim, rate_wanted;
17302 		uint32_t segs, oh;
17303 		int capped = 0;
17304 		int prev_fill;
17305 
17306 		if ((rack->r_rr_config == 1) && rsm) {
17307 			return (rack->r_ctl.rc_min_to);
17308 		}
17309 		if (rack->use_fixed_rate) {
17310 			rate_wanted = bw_est = rack_get_fixed_pacing_bw(rack);
17311 		} else if ((rack->r_ctl.init_rate == 0) &&
17312 			   (rack->r_ctl.gp_bw == 0)) {
17313 			/* no way to yet do an estimate */
17314 			bw_est = rate_wanted = 0;
17315 		} else if (rack->dgp_on) {
17316 			bw_est = rack_get_bw(rack);
17317 			rate_wanted = rack_get_output_bw(rack, bw_est, rsm, &capped);
17318 		} else {
17319 			uint32_t gain, rate_set = 0;
17320 
17321 			rate_wanted = min(rack->rc_tp->snd_cwnd, rack->r_ctl.cwnd_to_use);
17322 			rate_wanted = rack_arrive_at_discounted_rate(rack, rate_wanted, &rate_set, &gain);
17323 			if (rate_set == 0) {
17324 				if (rate_wanted > rack->rc_tp->snd_wnd)
17325 					rate_wanted = rack->rc_tp->snd_wnd;
17326 				/* Now lets make it into a b/w */
17327 				rate_wanted *= (uint64_t)HPTS_USEC_IN_SEC;
17328 				rate_wanted /= (uint64_t)rack->r_ctl.rc_last_us_rtt;
17329 			}
17330 			bw_est = rate_wanted;
17331 			rack_log_pacing_delay_calc(rack, rack->rc_tp->snd_cwnd,
17332 						   rack->r_ctl.cwnd_to_use,
17333 						   rate_wanted, bw_est,
17334 						   rack->r_ctl.rc_last_us_rtt,
17335 						   88, __LINE__, NULL, gain);
17336 		}
17337 		if (((bw_est == 0) || (rate_wanted == 0) || (rack->gp_ready == 0)) &&
17338 		    (rack->use_fixed_rate == 0)) {
17339 			/*
17340 			 * No way yet to make a b/w estimate or
17341 			 * our raise is set incorrectly.
17342 			 */
17343 			goto old_method;
17344 		}
17345 		rack_rate_cap_bw(rack, &rate_wanted, &capped);
17346 		/* We need to account for all the overheads */
17347 		segs = (len + segsiz - 1) / segsiz;
17348 		/*
17349 		 * We need the diff between 1514 bytes (e-mtu with e-hdr)
17350 		 * and how much data we put in each packet. Yes this
17351 		 * means we may be off if we are larger than 1500 bytes
17352 		 * or smaller. But this just makes us more conservative.
17353 		 */
17354 
17355 		oh =  (tp->t_maxseg - segsiz) + sizeof(struct tcphdr);
17356 		if (rack->r_is_v6) {
17357 #ifdef INET6
17358 			oh += sizeof(struct ip6_hdr);
17359 #endif
17360 		} else {
17361 #ifdef INET
17362 			oh += sizeof(struct ip);
17363 #endif
17364 		}
17365 		/* We add a fixed 14 for the ethernet header */
17366 		oh += 14;
17367 		segs *= oh;
17368 		lentim = (uint64_t)(len + segs) * (uint64_t)HPTS_USEC_IN_SEC;
17369 		res = lentim / rate_wanted;
17370 		pacing_delay = (uint32_t)res;
17371 		if (rack_hw_rate_min &&
17372 		    (rate_wanted < rack_hw_rate_min)) {
17373 			can_start_hw_pacing = 0;
17374 			if (rack->r_ctl.crte) {
17375 				/*
17376 				 * Ok we need to release it, we
17377 				 * have fallen too low.
17378 				 */
17379 				tcp_rel_pacing_rate(rack->r_ctl.crte, rack->rc_tp);
17380 				rack->r_ctl.crte = NULL;
17381 				rack->rack_attempt_hdwr_pace = 0;
17382 				rack->rack_hdrw_pacing = 0;
17383 			}
17384 		}
17385 		if (rack->r_ctl.crte &&
17386 		    (tcp_hw_highest_rate(rack->r_ctl.crte) < rate_wanted)) {
17387 			/*
17388 			 * We want more than the hardware can give us,
17389 			 * don't start any hw pacing.
17390 			 */
17391 			can_start_hw_pacing = 0;
17392 			if (rack->r_rack_hw_rate_caps == 0) {
17393 				/*
17394 				 * Ok we need to release it, we
17395 				 * want more than the card can give us and
17396 				 * no rate cap is in place. Set it up so
17397 				 * when we want less we can retry.
17398 				 */
17399 				tcp_rel_pacing_rate(rack->r_ctl.crte, rack->rc_tp);
17400 				rack->r_ctl.crte = NULL;
17401 				rack->rack_attempt_hdwr_pace = 0;
17402 				rack->rack_hdrw_pacing = 0;
17403 			}
17404 		}
17405 		if ((rack->r_ctl.crte != NULL) && (rack->rc_inp->inp_snd_tag == NULL)) {
17406 			/*
17407 			 * We lost our rate somehow, this can happen
17408 			 * if the interface changed underneath us.
17409 			 */
17410 			tcp_rel_pacing_rate(rack->r_ctl.crte, rack->rc_tp);
17411 			rack->r_ctl.crte = NULL;
17412 			/* Lets re-allow attempting to setup pacing */
17413 			rack->rack_hdrw_pacing = 0;
17414 			rack->rack_attempt_hdwr_pace = 0;
17415 			rack_log_hdwr_pacing(rack,
17416 					     rate_wanted, bw_est, __LINE__,
17417 					     0, 6);
17418 		}
17419 		prev_fill = rack->r_via_fill_cw;
17420 		if ((rack->rc_pace_to_cwnd) &&
17421 		    (capped == 0) &&
17422 		    (rack->dgp_on == 1) &&
17423 		    (rack->use_fixed_rate == 0) &&
17424 		    (rack->in_probe_rtt == 0) &&
17425 		    (IN_FASTRECOVERY(rack->rc_tp->t_flags) == 0)) {
17426 			/*
17427 			 * We want to pace at our rate *or* faster to
17428 			 * fill the cwnd to the max if its not full.
17429 			 */
17430 			pacing_delay = pace_to_fill_cwnd(rack, pacing_delay, (len+segs), segsiz, &capped, &rate_wanted, 0);
17431 			/* Re-check to make sure we are not exceeding our max b/w */
17432 			if ((rack->r_ctl.crte != NULL) &&
17433 			    (tcp_hw_highest_rate(rack->r_ctl.crte) < rate_wanted)) {
17434 				/*
17435 				 * We want more than the hardware can give us,
17436 				 * don't start any hw pacing.
17437 				 */
17438 				can_start_hw_pacing = 0;
17439 				if (rack->r_rack_hw_rate_caps == 0) {
17440 					/*
17441 					 * Ok we need to release it, we
17442 					 * want more than the card can give us and
17443 					 * no rate cap is in place. Set it up so
17444 					 * when we want less we can retry.
17445 					 */
17446 					tcp_rel_pacing_rate(rack->r_ctl.crte, rack->rc_tp);
17447 					rack->r_ctl.crte = NULL;
17448 					rack->rack_attempt_hdwr_pace = 0;
17449 					rack->rack_hdrw_pacing = 0;
17450 					rack_set_pace_segments(rack->rc_tp, rack, __LINE__, NULL);
17451 				}
17452 			}
17453 		}
17454 		if ((rack->rc_inp->inp_route.ro_nh != NULL) &&
17455 		    (rack->rc_inp->inp_route.ro_nh->nh_ifp != NULL)) {
17456 			if ((rack->rack_hdw_pace_ena) &&
17457 			    (can_start_hw_pacing > 0) &&
17458 			    (rack->rack_hdrw_pacing == 0) &&
17459 			    (rack->rack_attempt_hdwr_pace == 0)) {
17460 				/*
17461 				 * Lets attempt to turn on hardware pacing
17462 				 * if we can.
17463 				 */
17464 				rack->rack_attempt_hdwr_pace = 1;
17465 				rack->r_ctl.crte = tcp_set_pacing_rate(rack->rc_tp,
17466 								       rack->rc_inp->inp_route.ro_nh->nh_ifp,
17467 								       rate_wanted,
17468 								       RS_PACING_GEQ,
17469 								       &err, &rack->r_ctl.crte_prev_rate);
17470 				if (rack->r_ctl.crte) {
17471 					rack->rack_hdrw_pacing = 1;
17472 					rack->r_ctl.rc_pace_max_segs = tcp_get_pacing_burst_size_w_divisor(tp, rate_wanted, segsiz,
17473 													   pace_one, rack->r_ctl.crte,
17474 													   NULL, rack->r_ctl.pace_len_divisor);
17475 					rack_log_hdwr_pacing(rack,
17476 							     rate_wanted, rack->r_ctl.crte->rate, __LINE__,
17477 							     err, 0);
17478 					rack->r_ctl.last_hw_bw_req = rate_wanted;
17479 				} else {
17480 					counter_u64_add(rack_hw_pace_init_fail, 1);
17481 				}
17482 			} else if (rack->rack_hdrw_pacing &&
17483 				   (rack->r_ctl.last_hw_bw_req != rate_wanted)) {
17484 				/* Do we need to adjust our rate? */
17485 				const struct tcp_hwrate_limit_table *nrte;
17486 
17487 				if (rack->r_up_only &&
17488 				    (rate_wanted < rack->r_ctl.crte->rate)) {
17489 					/**
17490 					 * We have four possible states here
17491 					 * having to do with the previous time
17492 					 * and this time.
17493 					 *   previous  |  this-time
17494 					 * A)     0      |     0   -- fill_cw not in the picture
17495 					 * B)     1      |     0   -- we were doing a fill-cw but now are not
17496 					 * C)     1      |     1   -- all rates from fill_cw
17497 					 * D)     0      |     1   -- we were doing non-fill and now we are filling
17498 					 *
17499 					 * For case A, C and D we don't allow a drop. But for
17500 					 * case B where we now our on our steady rate we do
17501 					 * allow a drop.
17502 					 *
17503 					 */
17504 					if (!((prev_fill == 1) && (rack->r_via_fill_cw == 0)))
17505 						goto done_w_hdwr;
17506 				}
17507 				if ((rate_wanted > rack->r_ctl.crte->rate) ||
17508 				    (rate_wanted <= rack->r_ctl.crte_prev_rate)) {
17509 					if (rack_hw_rate_to_low &&
17510 					    (bw_est < rack_hw_rate_to_low)) {
17511 						/*
17512 						 * The pacing rate is too low for hardware, but
17513 						 * do allow hardware pacing to be restarted.
17514 						 */
17515 						rack_log_hdwr_pacing(rack,
17516 								     bw_est, rack->r_ctl.crte->rate, __LINE__,
17517 								     0, 5);
17518 						tcp_rel_pacing_rate(rack->r_ctl.crte, rack->rc_tp);
17519 						rack->r_ctl.crte = NULL;
17520 						rack->rack_attempt_hdwr_pace = 0;
17521 						rack->rack_hdrw_pacing = 0;
17522 						rack_set_pace_segments(rack->rc_tp, rack, __LINE__, &rate_wanted);
17523 						goto done_w_hdwr;
17524 					}
17525 					nrte = tcp_chg_pacing_rate(rack->r_ctl.crte,
17526 								   rack->rc_tp,
17527 								   rack->rc_inp->inp_route.ro_nh->nh_ifp,
17528 								   rate_wanted,
17529 								   RS_PACING_GEQ,
17530 								   &err, &rack->r_ctl.crte_prev_rate);
17531 					if (nrte == NULL) {
17532 						/*
17533 						 * Lost the rate, lets drop hardware pacing
17534 						 * period.
17535 						 */
17536 						rack->rack_hdrw_pacing = 0;
17537 						rack->r_ctl.crte = NULL;
17538 						rack_log_hdwr_pacing(rack,
17539 								     rate_wanted, 0, __LINE__,
17540 								     err, 1);
17541 						rack_set_pace_segments(rack->rc_tp, rack, __LINE__, &rate_wanted);
17542 						counter_u64_add(rack_hw_pace_lost, 1);
17543 					} else if (nrte != rack->r_ctl.crte) {
17544 						rack->r_ctl.crte = nrte;
17545 						rack->r_ctl.rc_pace_max_segs = tcp_get_pacing_burst_size_w_divisor(tp, rate_wanted,
17546 														   segsiz, pace_one, rack->r_ctl.crte,
17547 														   NULL, rack->r_ctl.pace_len_divisor);
17548 						rack_log_hdwr_pacing(rack,
17549 								     rate_wanted, rack->r_ctl.crte->rate, __LINE__,
17550 								     err, 2);
17551 						rack->r_ctl.last_hw_bw_req = rate_wanted;
17552 					}
17553 				} else {
17554 					/* We just need to adjust the segment size */
17555 					rack_set_pace_segments(rack->rc_tp, rack, __LINE__, &rate_wanted);
17556 					rack_log_hdwr_pacing(rack,
17557 							     rate_wanted, rack->r_ctl.crte->rate, __LINE__,
17558 							     0, 4);
17559 					rack->r_ctl.last_hw_bw_req = rate_wanted;
17560 				}
17561 			}
17562 		}
17563 	done_w_hdwr:
17564 		if (rack_limit_time_with_srtt &&
17565 		    (rack->use_fixed_rate == 0) &&
17566 		    (rack->rack_hdrw_pacing == 0)) {
17567 			/*
17568 			 * Sanity check, we do not allow the pacing delay
17569 			 * to be longer than the SRTT of the path. If it is
17570 			 * a slow path, then adding a packet should increase
17571 			 * the RTT and compensate for this i.e. the srtt will
17572 			 * be greater so the allowed pacing time will be greater.
17573 			 *
17574 			 * Note this restriction is not for where a peak rate
17575 			 * is set, we are doing fixed pacing or hardware pacing.
17576 			 */
17577 			if (rack->rc_tp->t_srtt)
17578 				srtt = rack->rc_tp->t_srtt;
17579 			else
17580 				srtt = RACK_INITIAL_RTO * HPTS_USEC_IN_MSEC;	/* its in ms convert */
17581 			if (srtt < (uint64_t)pacing_delay) {
17582 				rack_log_pacing_delay_calc(rack, srtt, pacing_delay, rate_wanted, bw_est, lentim, 99, __LINE__, NULL, 0);
17583 				pacing_delay = srtt;
17584 			}
17585 		}
17586 		/*******************************************************************/
17587 		/* RRS: We insert paced call to stats here for len and rate_wanted */
17588 		/*******************************************************************/
17589 		rack_log_pacing_delay_calc(rack, len, pacing_delay, rate_wanted, bw_est, lentim, 2, __LINE__, rsm, 0);
17590 	}
17591 	if (rack->r_ctl.crte && (rack->r_ctl.crte->rs_num_enobufs > 0)) {
17592 		/*
17593 		 * If this rate is seeing enobufs when it
17594 		 * goes to send then either the nic is out
17595 		 * of gas or we are mis-estimating the time
17596 		 * somehow and not letting the queue empty
17597 		 * completely. Lets add to the pacing time.
17598 		 */
17599 		int hw_boost_delay;
17600 
17601 		hw_boost_delay = rack->r_ctl.crte->time_between * rack_enobuf_hw_boost_mult;
17602 		if (hw_boost_delay > rack_enobuf_hw_max)
17603 			hw_boost_delay = rack_enobuf_hw_max;
17604 		else if (hw_boost_delay < rack_enobuf_hw_min)
17605 			hw_boost_delay = rack_enobuf_hw_min;
17606 		pacing_delay += hw_boost_delay;
17607 	}
17608 	return (pacing_delay);
17609 }
17610 
17611 static void
17612 rack_start_gp_measurement(struct tcpcb *tp, struct tcp_rack *rack,
17613     tcp_seq startseq, uint32_t sb_offset)
17614 {
17615 	struct rack_sendmap *my_rsm = NULL;
17616 
17617 	if (tp->t_state < TCPS_ESTABLISHED) {
17618 		/*
17619 		 * We don't start any measurements if we are
17620 		 * not at least established.
17621 		 */
17622 		return;
17623 	}
17624 	if (tp->t_state >= TCPS_FIN_WAIT_1) {
17625 		/*
17626 		 * We will get no more data into the SB
17627 		 * this means we need to have the data available
17628 		 * before we start a measurement.
17629 		 */
17630 
17631 		if (sbavail(&tptosocket(tp)->so_snd) <
17632 		    max(rc_init_window(rack),
17633 			(MIN_GP_WIN * ctf_fixed_maxseg(tp)))) {
17634 			/* Nope not enough data */
17635 			return;
17636 		}
17637 	}
17638 	tp->t_flags |= TF_GPUTINPROG;
17639 	rack->r_ctl.rc_gp_cumack_ts = 0;
17640 	rack->r_ctl.rc_gp_lowrtt = 0xffffffff;
17641 	rack->r_ctl.rc_gp_high_rwnd = rack->rc_tp->snd_wnd;
17642 	tp->gput_seq = startseq;
17643 	rack->app_limited_needs_set = 0;
17644 	if (rack->in_probe_rtt)
17645 		rack->measure_saw_probe_rtt = 1;
17646 	else if ((rack->measure_saw_probe_rtt) &&
17647 		 (SEQ_GEQ(tp->gput_seq, rack->r_ctl.rc_probertt_sndmax_atexit)))
17648 		rack->measure_saw_probe_rtt = 0;
17649 	if (rack->rc_gp_filled)
17650 		tp->gput_ts = rack->r_ctl.last_cumack_advance;
17651 	else {
17652 		/* Special case initial measurement */
17653 		struct timeval tv;
17654 
17655 		tp->gput_ts = tcp_get_usecs(&tv);
17656 		rack->r_ctl.rc_gp_output_ts = rack_to_usec_ts(&tv);
17657 	}
17658 	/*
17659 	 * We take a guess out into the future,
17660 	 * if we have no measurement and no
17661 	 * initial rate, we measure the first
17662 	 * initial-windows worth of data to
17663 	 * speed up getting some GP measurement and
17664 	 * thus start pacing.
17665 	 */
17666 	if ((rack->rc_gp_filled == 0) && (rack->r_ctl.init_rate == 0)) {
17667 		rack->app_limited_needs_set = 1;
17668 		tp->gput_ack = startseq + max(rc_init_window(rack),
17669 					      (MIN_GP_WIN * ctf_fixed_maxseg(tp)));
17670 		rack_log_pacing_delay_calc(rack,
17671 					   tp->gput_seq,
17672 					   tp->gput_ack,
17673 					   0,
17674 					   tp->gput_ts,
17675 					   (((uint64_t)rack->r_ctl.rc_app_limited_cnt << 32) | (uint64_t)rack->r_ctl.rc_gp_output_ts),
17676 					   9,
17677 					   __LINE__, NULL, 0);
17678 		rack_tend_gp_marks(tp, rack);
17679 		rack_log_gpset(rack, tp->gput_ack, 0, 0, __LINE__, 1, NULL);
17680 		return;
17681 	}
17682 	if (sb_offset) {
17683 		/*
17684 		 * We are out somewhere in the sb
17685 		 * can we use the already outstanding data?
17686 		 */
17687 
17688 		if (rack->r_ctl.rc_app_limited_cnt == 0) {
17689 			/*
17690 			 * Yes first one is good and in this case
17691 			 * the tp->gput_ts is correctly set based on
17692 			 * the last ack that arrived (no need to
17693 			 * set things up when an ack comes in).
17694 			 */
17695 			my_rsm = tqhash_min(rack->r_ctl.tqh);
17696 			if ((my_rsm == NULL) ||
17697 			    (my_rsm->r_rtr_cnt != 1)) {
17698 				/* retransmission? */
17699 				goto use_latest;
17700 			}
17701 		} else {
17702 			if (rack->r_ctl.rc_first_appl == NULL) {
17703 				/*
17704 				 * If rc_first_appl is NULL
17705 				 * then the cnt should be 0.
17706 				 * This is probably an error, maybe
17707 				 * a KASSERT would be approprate.
17708 				 */
17709 				goto use_latest;
17710 			}
17711 			/*
17712 			 * If we have a marker pointer to the last one that is
17713 			 * app limited we can use that, but we need to set
17714 			 * things up so that when it gets ack'ed we record
17715 			 * the ack time (if its not already acked).
17716 			 */
17717 			rack->app_limited_needs_set = 1;
17718 			/*
17719 			 * We want to get to the rsm that is either
17720 			 * next with space i.e. over 1 MSS or the one
17721 			 * after that (after the app-limited).
17722 			 */
17723 			my_rsm = tqhash_next(rack->r_ctl.tqh, rack->r_ctl.rc_first_appl);
17724 			if (my_rsm) {
17725 				if ((my_rsm->r_end - my_rsm->r_start) <= ctf_fixed_maxseg(tp))
17726 					/* Have to use the next one */
17727 					my_rsm = tqhash_next(rack->r_ctl.tqh, my_rsm);
17728 				else {
17729 					/* Use after the first MSS of it is acked */
17730 					tp->gput_seq = my_rsm->r_start + ctf_fixed_maxseg(tp);
17731 					goto start_set;
17732 				}
17733 			}
17734 			if ((my_rsm == NULL) ||
17735 			    (my_rsm->r_rtr_cnt != 1)) {
17736 				/*
17737 				 * Either its a retransmit or
17738 				 * the last is the app-limited one.
17739 				 */
17740 				goto use_latest;
17741 			}
17742 		}
17743 		tp->gput_seq = my_rsm->r_start;
17744 start_set:
17745 		if (my_rsm->r_flags & RACK_ACKED) {
17746 			/*
17747 			 * This one has been acked use the arrival ack time
17748 			 */
17749 			struct rack_sendmap *nrsm;
17750 
17751 			tp->gput_ts = (uint32_t)my_rsm->r_ack_arrival;
17752 			rack->app_limited_needs_set = 0;
17753 			/*
17754 			 * Ok in this path we need to use the r_end now
17755 			 * since this guy is the starting ack.
17756 			 */
17757 			tp->gput_seq = my_rsm->r_end;
17758 			/*
17759 			 * We also need to adjust up the sendtime
17760 			 * to the send of the next data after my_rsm.
17761 			 */
17762 			nrsm = tqhash_next(rack->r_ctl.tqh, my_rsm);
17763 			if (nrsm != NULL)
17764 				my_rsm = nrsm;
17765 			else {
17766 				/*
17767 				 * The next as not been sent, thats the
17768 				 * case for using the latest.
17769 				 */
17770 				goto use_latest;
17771 			}
17772 		}
17773 		rack->r_ctl.rc_gp_output_ts = my_rsm->r_tim_lastsent[0];
17774 		tp->gput_ack = tp->gput_seq + rack_get_measure_window(tp, rack);
17775 		rack->r_ctl.rc_gp_cumack_ts = 0;
17776 		if ((rack->r_ctl.cleared_app_ack == 1) &&
17777 		    (SEQ_GEQ(tp->gput_seq, rack->r_ctl.cleared_app_ack_seq))) {
17778 			/*
17779 			 * We just cleared an application limited period
17780 			 * so the next seq out needs to skip the first
17781 			 * ack.
17782 			 */
17783 			rack->app_limited_needs_set = 1;
17784 			rack->r_ctl.cleared_app_ack = 0;
17785 		}
17786 		rack_log_pacing_delay_calc(rack,
17787 					   tp->gput_seq,
17788 					   tp->gput_ack,
17789 					   (uintptr_t)my_rsm,
17790 					   tp->gput_ts,
17791 					   (((uint64_t)rack->r_ctl.rc_app_limited_cnt << 32) | (uint64_t)rack->r_ctl.rc_gp_output_ts),
17792 					   9,
17793 					   __LINE__, my_rsm, 0);
17794 		/* Now lets make sure all are marked as they should be */
17795 		rack_tend_gp_marks(tp, rack);
17796 		rack_log_gpset(rack, tp->gput_ack, 0, 0, __LINE__, 1, NULL);
17797 		return;
17798 	}
17799 
17800 use_latest:
17801 	/*
17802 	 * We don't know how long we may have been
17803 	 * idle or if this is the first-send. Lets
17804 	 * setup the flag so we will trim off
17805 	 * the first ack'd data so we get a true
17806 	 * measurement.
17807 	 */
17808 	rack->app_limited_needs_set = 1;
17809 	tp->gput_ack = startseq + rack_get_measure_window(tp, rack);
17810 	rack->r_ctl.rc_gp_cumack_ts = 0;
17811 	/* Find this guy so we can pull the send time */
17812 	my_rsm = tqhash_find(rack->r_ctl.tqh, startseq);
17813 	if (my_rsm) {
17814 		rack->r_ctl.rc_gp_output_ts = my_rsm->r_tim_lastsent[0];
17815 		if (my_rsm->r_flags & RACK_ACKED) {
17816 			/*
17817 			 * Unlikely since its probably what was
17818 			 * just transmitted (but I am paranoid).
17819 			 */
17820 			tp->gput_ts = (uint32_t)my_rsm->r_ack_arrival;
17821 			rack->app_limited_needs_set = 0;
17822 		}
17823 		if (SEQ_LT(my_rsm->r_start, tp->gput_seq)) {
17824 			/* This also is unlikely */
17825 			tp->gput_seq = my_rsm->r_start;
17826 		}
17827 	} else {
17828 		/*
17829 		 * TSNH unless we have some send-map limit,
17830 		 * and even at that it should not be hitting
17831 		 * that limit (we should have stopped sending).
17832 		 */
17833 		struct timeval tv;
17834 
17835 		microuptime(&tv);
17836 		rack->r_ctl.rc_gp_output_ts = rack_to_usec_ts(&tv);
17837 	}
17838 	rack_tend_gp_marks(tp, rack);
17839 	rack_log_pacing_delay_calc(rack,
17840 				   tp->gput_seq,
17841 				   tp->gput_ack,
17842 				   (uintptr_t)my_rsm,
17843 				   tp->gput_ts,
17844 				   (((uint64_t)rack->r_ctl.rc_app_limited_cnt << 32) | (uint64_t)rack->r_ctl.rc_gp_output_ts),
17845 				   9, __LINE__, NULL, 0);
17846 	rack_log_gpset(rack, tp->gput_ack, 0, 0, __LINE__, 1, NULL);
17847 }
17848 
17849 static inline uint32_t
17850 rack_what_can_we_send(struct tcpcb *tp, struct tcp_rack *rack,  uint32_t cwnd_to_use,
17851     uint32_t avail, int32_t sb_offset)
17852 {
17853 	uint32_t len;
17854 	uint32_t sendwin;
17855 
17856 	if (tp->snd_wnd > cwnd_to_use)
17857 		sendwin = cwnd_to_use;
17858 	else
17859 		sendwin = tp->snd_wnd;
17860 	if (ctf_outstanding(tp) >= tp->snd_wnd) {
17861 		/* We never want to go over our peers rcv-window */
17862 		len = 0;
17863 	} else {
17864 		uint32_t flight;
17865 
17866 		flight = ctf_flight_size(tp, rack->r_ctl.rc_sacked);
17867 		if (flight >= sendwin) {
17868 			/*
17869 			 * We have in flight what we are allowed by cwnd (if
17870 			 * it was rwnd blocking it would have hit above out
17871 			 * >= tp->snd_wnd).
17872 			 */
17873 			return (0);
17874 		}
17875 		len = sendwin - flight;
17876 		if ((len + ctf_outstanding(tp)) > tp->snd_wnd) {
17877 			/* We would send too much (beyond the rwnd) */
17878 			len = tp->snd_wnd - ctf_outstanding(tp);
17879 		}
17880 		if ((len + sb_offset) > avail) {
17881 			/*
17882 			 * We don't have that much in the SB, how much is
17883 			 * there?
17884 			 */
17885 			len = avail - sb_offset;
17886 		}
17887 	}
17888 	return (len);
17889 }
17890 
17891 static void
17892 rack_log_fsb(struct tcp_rack *rack, struct tcpcb *tp, struct socket *so, uint32_t flags,
17893 	     unsigned ipoptlen, int32_t orig_len, int32_t len, int error,
17894 	     int rsm_is_null, int optlen, int line, uint16_t mode)
17895 {
17896 	if (rack_verbose_logging && tcp_bblogging_on(rack->rc_tp)) {
17897 		union tcp_log_stackspecific log;
17898 		struct timeval tv;
17899 
17900 		memset(&log, 0, sizeof(log));
17901 		log.u_bbr.inhpts = tcp_in_hpts(rack->rc_tp);
17902 		log.u_bbr.flex1 = error;
17903 		log.u_bbr.flex2 = flags;
17904 		log.u_bbr.flex3 = rsm_is_null;
17905 		log.u_bbr.flex4 = ipoptlen;
17906 		log.u_bbr.flex5 = tp->rcv_numsacks;
17907 		log.u_bbr.flex6 = rack->r_ctl.rc_agg_early;
17908 		log.u_bbr.flex7 = optlen;
17909 		log.u_bbr.flex8 = rack->r_fsb_inited;
17910 		log.u_bbr.applimited = rack->r_fast_output;
17911 		log.u_bbr.bw_inuse = rack_get_bw(rack);
17912 		log.u_bbr.pacing_gain = rack_get_output_gain(rack, NULL);
17913 		log.u_bbr.cwnd_gain = mode;
17914 		log.u_bbr.pkts_out = orig_len;
17915 		log.u_bbr.lt_epoch = len;
17916 		log.u_bbr.delivered = line;
17917 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
17918 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
17919 		tcp_log_event(tp, NULL, &so->so_rcv, &so->so_snd, TCP_LOG_FSB, 0,
17920 			       len, &log, false, NULL, __func__, __LINE__, &tv);
17921 	}
17922 }
17923 
17924 
17925 static struct mbuf *
17926 rack_fo_base_copym(struct mbuf *the_m, uint32_t the_off, int32_t *plen,
17927 		   struct rack_fast_send_blk *fsb,
17928 		   int32_t seglimit, int32_t segsize, int hw_tls)
17929 {
17930 #ifdef KERN_TLS
17931 	struct ktls_session *tls, *ntls;
17932 #ifdef INVARIANTS
17933 	struct mbuf *start;
17934 #endif
17935 #endif
17936 	struct mbuf *m, *n, **np, *smb;
17937 	struct mbuf *top;
17938 	int32_t off, soff;
17939 	int32_t len = *plen;
17940 	int32_t fragsize;
17941 	int32_t len_cp = 0;
17942 	uint32_t mlen, frags;
17943 
17944 	soff = off = the_off;
17945 	smb = m = the_m;
17946 	np = &top;
17947 	top = NULL;
17948 #ifdef KERN_TLS
17949 	if (hw_tls && (m->m_flags & M_EXTPG))
17950 		tls = m->m_epg_tls;
17951 	else
17952 		tls = NULL;
17953 #ifdef INVARIANTS
17954 	start = m;
17955 #endif
17956 #endif
17957 	while (len > 0) {
17958 		if (m == NULL) {
17959 			*plen = len_cp;
17960 			break;
17961 		}
17962 #ifdef KERN_TLS
17963 		if (hw_tls) {
17964 			if (m->m_flags & M_EXTPG)
17965 				ntls = m->m_epg_tls;
17966 			else
17967 				ntls = NULL;
17968 
17969 			/*
17970 			 * Avoid mixing TLS records with handshake
17971 			 * data or TLS records from different
17972 			 * sessions.
17973 			 */
17974 			if (tls != ntls) {
17975 				MPASS(m != start);
17976 				*plen = len_cp;
17977 				break;
17978 			}
17979 		}
17980 #endif
17981 		mlen = min(len, m->m_len - off);
17982 		if (seglimit) {
17983 			/*
17984 			 * For M_EXTPG mbufs, add 3 segments
17985 			 * + 1 in case we are crossing page boundaries
17986 			 * + 2 in case the TLS hdr/trailer are used
17987 			 * It is cheaper to just add the segments
17988 			 * than it is to take the cache miss to look
17989 			 * at the mbuf ext_pgs state in detail.
17990 			 */
17991 			if (m->m_flags & M_EXTPG) {
17992 				fragsize = min(segsize, PAGE_SIZE);
17993 				frags = 3;
17994 			} else {
17995 				fragsize = segsize;
17996 				frags = 0;
17997 			}
17998 
17999 			/* Break if we really can't fit anymore. */
18000 			if ((frags + 1) >= seglimit) {
18001 				*plen =	len_cp;
18002 				break;
18003 			}
18004 
18005 			/*
18006 			 * Reduce size if you can't copy the whole
18007 			 * mbuf. If we can't copy the whole mbuf, also
18008 			 * adjust len so the loop will end after this
18009 			 * mbuf.
18010 			 */
18011 			if ((frags + howmany(mlen, fragsize)) >= seglimit) {
18012 				mlen = (seglimit - frags - 1) * fragsize;
18013 				len = mlen;
18014 				*plen = len_cp + len;
18015 			}
18016 			frags += howmany(mlen, fragsize);
18017 			if (frags == 0)
18018 				frags++;
18019 			seglimit -= frags;
18020 			KASSERT(seglimit > 0,
18021 			    ("%s: seglimit went too low", __func__));
18022 		}
18023 		n = m_get(M_NOWAIT, m->m_type);
18024 		*np = n;
18025 		if (n == NULL)
18026 			goto nospace;
18027 		n->m_len = mlen;
18028 		soff += mlen;
18029 		len_cp += n->m_len;
18030 		if (m->m_flags & (M_EXT | M_EXTPG)) {
18031 			n->m_data = m->m_data + off;
18032 			mb_dupcl(n, m);
18033 		} else {
18034 			bcopy(mtod(m, caddr_t)+off, mtod(n, caddr_t),
18035 			    (u_int)n->m_len);
18036 		}
18037 		len -= n->m_len;
18038 		off = 0;
18039 		m = m->m_next;
18040 		np = &n->m_next;
18041 		if (len || (soff == smb->m_len)) {
18042 			/*
18043 			 * We have more so we move forward  or
18044 			 * we have consumed the entire mbuf and
18045 			 * len has fell to 0.
18046 			 */
18047 			soff = 0;
18048 			smb = m;
18049 		}
18050 
18051 	}
18052 	if (fsb != NULL) {
18053 		fsb->m = smb;
18054 		fsb->off = soff;
18055 		if (smb) {
18056 			/*
18057 			 * Save off the size of the mbuf. We do
18058 			 * this so that we can recognize when it
18059 			 * has been trimmed by sbcut() as acks
18060 			 * come in.
18061 			 */
18062 			fsb->o_m_len = smb->m_len;
18063 			fsb->o_t_len = M_TRAILINGROOM(smb);
18064 		} else {
18065 			/*
18066 			 * This is the case where the next mbuf went to NULL. This
18067 			 * means with this copy we have sent everything in the sb.
18068 			 * In theory we could clear the fast_output flag, but lets
18069 			 * not since its possible that we could get more added
18070 			 * and acks that call the extend function which would let
18071 			 * us send more.
18072 			 */
18073 			fsb->o_m_len = 0;
18074 			fsb->o_t_len = 0;
18075 		}
18076 	}
18077 	return (top);
18078 nospace:
18079 	if (top)
18080 		m_freem(top);
18081 	return (NULL);
18082 
18083 }
18084 
18085 /*
18086  * This is a copy of m_copym(), taking the TSO segment size/limit
18087  * constraints into account, and advancing the sndptr as it goes.
18088  */
18089 static struct mbuf *
18090 rack_fo_m_copym(struct tcp_rack *rack, int32_t *plen,
18091 		int32_t seglimit, int32_t segsize, struct mbuf **s_mb, int *s_soff)
18092 {
18093 	struct mbuf *m, *n;
18094 	int32_t soff;
18095 
18096 	m = rack->r_ctl.fsb.m;
18097 	if (M_TRAILINGROOM(m) != rack->r_ctl.fsb.o_t_len) {
18098 		/*
18099 		 * The trailing space changed, mbufs can grow
18100 		 * at the tail but they can't shrink from
18101 		 * it, KASSERT that. Adjust the orig_m_len to
18102 		 * compensate for this change.
18103 		 */
18104 		KASSERT((rack->r_ctl.fsb.o_t_len > M_TRAILINGROOM(m)),
18105 			("mbuf:%p rack:%p trailing_space:%jd ots:%u oml:%u mlen:%u\n",
18106 			 m,
18107 			 rack,
18108 			 (intmax_t)M_TRAILINGROOM(m),
18109 			 rack->r_ctl.fsb.o_t_len,
18110 			 rack->r_ctl.fsb.o_m_len,
18111 			 m->m_len));
18112 		rack->r_ctl.fsb.o_m_len += (rack->r_ctl.fsb.o_t_len - M_TRAILINGROOM(m));
18113 		rack->r_ctl.fsb.o_t_len = M_TRAILINGROOM(m);
18114 	}
18115 	if (m->m_len < rack->r_ctl.fsb.o_m_len) {
18116 		/*
18117 		 * Mbuf shrank, trimmed off the top by an ack, our
18118 		 * offset changes.
18119 		 */
18120 		KASSERT((rack->r_ctl.fsb.off >= (rack->r_ctl.fsb.o_m_len - m->m_len)),
18121 			("mbuf:%p len:%u rack:%p oml:%u soff:%u\n",
18122 			 m, m->m_len,
18123 			 rack, rack->r_ctl.fsb.o_m_len,
18124 			 rack->r_ctl.fsb.off));
18125 
18126 		if (rack->r_ctl.fsb.off >= (rack->r_ctl.fsb.o_m_len- m->m_len))
18127 			rack->r_ctl.fsb.off -= (rack->r_ctl.fsb.o_m_len - m->m_len);
18128 		else
18129 			rack->r_ctl.fsb.off = 0;
18130 		rack->r_ctl.fsb.o_m_len = m->m_len;
18131 #ifdef INVARIANTS
18132 	} else if (m->m_len > rack->r_ctl.fsb.o_m_len) {
18133 		panic("rack:%p m:%p m_len grew outside of t_space compensation",
18134 		      rack, m);
18135 #endif
18136 	}
18137 	soff = rack->r_ctl.fsb.off;
18138 	KASSERT(soff >= 0, ("%s, negative off %d", __FUNCTION__, soff));
18139 	KASSERT(*plen >= 0, ("%s, negative len %d", __FUNCTION__, *plen));
18140 	KASSERT(soff < m->m_len, ("%s rack:%p len:%u m:%p m->m_len:%u < off?",
18141 				 __FUNCTION__,
18142 				 rack, *plen, m, m->m_len));
18143 	/* Save off the right location before we copy and advance */
18144 	*s_soff = soff;
18145 	*s_mb = rack->r_ctl.fsb.m;
18146 	n = rack_fo_base_copym(m, soff, plen,
18147 			       &rack->r_ctl.fsb,
18148 			       seglimit, segsize, rack->r_ctl.fsb.hw_tls);
18149 	return (n);
18150 }
18151 
18152 /* Log the buffer level */
18153 static void
18154 rack_log_queue_level(struct tcpcb *tp, struct tcp_rack *rack,
18155 		     int len, struct timeval *tv,
18156 		     uint32_t cts)
18157 {
18158 	uint32_t p_rate = 0, p_queue = 0, err = 0;
18159 	union tcp_log_stackspecific log;
18160 
18161 #ifdef RATELIMIT
18162 	err = in_pcbquery_txrlevel(rack->rc_inp, &p_queue);
18163 	err = in_pcbquery_txrtlmt(rack->rc_inp,	&p_rate);
18164 #endif
18165 	memset(&log, 0, sizeof(log));
18166 	log.u_bbr.inhpts = tcp_in_hpts(rack->rc_tp);
18167 	log.u_bbr.flex1 = p_rate;
18168 	log.u_bbr.flex2 = p_queue;
18169 	log.u_bbr.flex4 = (uint32_t)rack->r_ctl.crte->using;
18170 	log.u_bbr.flex5 = (uint32_t)rack->r_ctl.crte->rs_num_enobufs;
18171 	log.u_bbr.flex6 = rack->r_ctl.crte->time_between;
18172 	log.u_bbr.flex7 = 99;
18173 	log.u_bbr.flex8 = 0;
18174 	log.u_bbr.pkts_out = err;
18175 	log.u_bbr.delRate = rack->r_ctl.crte->rate;
18176 	log.u_bbr.timeStamp = cts;
18177 	log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
18178 	tcp_log_event(tp, NULL, NULL, NULL, BBR_LOG_HDWR_PACE, 0,
18179 		       len, &log, false, NULL, __func__, __LINE__, tv);
18180 
18181 }
18182 
18183 static uint32_t
18184 rack_check_queue_level(struct tcp_rack *rack, struct tcpcb *tp,
18185 		       struct timeval *tv, uint32_t cts, int len, uint32_t segsiz)
18186 {
18187 	uint64_t lentime = 0;
18188 #ifdef RATELIMIT
18189 	uint32_t p_rate = 0, p_queue = 0, err;
18190 	union tcp_log_stackspecific log;
18191 	uint64_t bw;
18192 
18193 	err = in_pcbquery_txrlevel(rack->rc_inp, &p_queue);
18194 	/* Failed or queue is zero */
18195 	if (err || (p_queue == 0)) {
18196 		lentime = 0;
18197 		goto out;
18198 	}
18199 	err = in_pcbquery_txrtlmt(rack->rc_inp, &p_rate);
18200 	if (err) {
18201 		lentime = 0;
18202 		goto out;
18203 	}
18204 	/*
18205 	 * If we reach here we have some bytes in
18206 	 * the queue. The number returned is a value
18207 	 * between 0 and 0xffff where ffff is full
18208 	 * and 0 is empty. So how best to make this into
18209 	 * something usable?
18210 	 *
18211 	 * The "safer" way is lets take the b/w gotten
18212 	 * from the query (which should be our b/w rate)
18213 	 * and pretend that a full send (our rc_pace_max_segs)
18214 	 * is outstanding. We factor it so its as if a full
18215 	 * number of our MSS segment is terms of full
18216 	 * ethernet segments are outstanding.
18217 	 */
18218 	bw = p_rate / 8;
18219 	if (bw) {
18220 		lentime = (rack->r_ctl.rc_pace_max_segs / segsiz);
18221 		lentime *= ETHERNET_SEGMENT_SIZE;
18222 		lentime *= (uint64_t)HPTS_USEC_IN_SEC;
18223 		lentime /= bw;
18224 	} else {
18225 		/* TSNH -- KASSERT? */
18226 		lentime = 0;
18227 	}
18228 out:
18229 	if (tcp_bblogging_on(tp)) {
18230 		memset(&log, 0, sizeof(log));
18231 		log.u_bbr.inhpts = tcp_in_hpts(rack->rc_tp);
18232 		log.u_bbr.flex1 = p_rate;
18233 		log.u_bbr.flex2 = p_queue;
18234 		log.u_bbr.flex4 = (uint32_t)rack->r_ctl.crte->using;
18235 		log.u_bbr.flex5 = (uint32_t)rack->r_ctl.crte->rs_num_enobufs;
18236 		log.u_bbr.flex6 = rack->r_ctl.crte->time_between;
18237 		log.u_bbr.flex7 = 99;
18238 		log.u_bbr.flex8 = 0;
18239 		log.u_bbr.pkts_out = err;
18240 		log.u_bbr.delRate = rack->r_ctl.crte->rate;
18241 		log.u_bbr.cur_del_rate = lentime;
18242 		log.u_bbr.timeStamp = cts;
18243 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
18244 		tcp_log_event(tp, NULL, NULL, NULL, BBR_LOG_HDWR_PACE, 0,
18245 			       len, &log, false, NULL, __func__, __LINE__,tv);
18246 	}
18247 #endif
18248 	return ((uint32_t)lentime);
18249 }
18250 
18251 static int
18252 rack_fast_rsm_output(struct tcpcb *tp, struct tcp_rack *rack, struct rack_sendmap *rsm,
18253 		     uint64_t ts_val, uint32_t cts, uint32_t ms_cts, struct timeval *tv, int len, uint8_t doing_tlp)
18254 {
18255 	/*
18256 	 * Enter the fast retransmit path. We are given that a sched_pin is
18257 	 * in place (if accounting is compliled in) and the cycle count taken
18258 	 * at the entry is in the ts_val. The concept her is that the rsm
18259 	 * now holds the mbuf offsets and such so we can directly transmit
18260 	 * without a lot of overhead, the len field is already set for
18261 	 * us to prohibit us from sending too much (usually its 1MSS).
18262 	 */
18263 	struct ip *ip = NULL;
18264 	struct udphdr *udp = NULL;
18265 	struct tcphdr *th = NULL;
18266 	struct mbuf *m = NULL;
18267 	struct inpcb *inp;
18268 	uint8_t *cpto;
18269 	struct tcp_log_buffer *lgb;
18270 #ifdef TCP_ACCOUNTING
18271 	uint64_t crtsc;
18272 	int cnt_thru = 1;
18273 #endif
18274 	struct tcpopt to;
18275 	u_char opt[TCP_MAXOLEN];
18276 	uint32_t hdrlen, optlen;
18277 	int32_t pacing_delay, segsiz, max_val, tso = 0, error = 0, ulen = 0;
18278 	uint16_t flags;
18279 	uint32_t if_hw_tsomaxsegcount = 0, startseq;
18280 	uint32_t if_hw_tsomaxsegsize;
18281 	int32_t ip_sendflag = IP_NO_SND_TAG_RL;
18282 
18283 #ifdef INET6
18284 	struct ip6_hdr *ip6 = NULL;
18285 
18286 	if (rack->r_is_v6) {
18287 		ip6 = (struct ip6_hdr *)rack->r_ctl.fsb.tcp_ip_hdr;
18288 		hdrlen = sizeof(struct ip6_hdr) + sizeof(struct tcphdr);
18289 	} else
18290 #endif				/* INET6 */
18291 	{
18292 		ip = (struct ip *)rack->r_ctl.fsb.tcp_ip_hdr;
18293 		hdrlen = sizeof(struct tcpiphdr);
18294 	}
18295 	if (tp->t_port && (V_tcp_udp_tunneling_port == 0)) {
18296 		goto failed;
18297 	}
18298 	if (doing_tlp) {
18299 		/* Its a TLP add the flag, it may already be there but be sure */
18300 		rsm->r_flags |= RACK_TLP;
18301 	} else {
18302 		/* If it was a TLP it is not not on this retransmit */
18303 		rsm->r_flags &= ~RACK_TLP;
18304 	}
18305 	startseq = rsm->r_start;
18306 	segsiz = min(ctf_fixed_maxseg(tp), rack->r_ctl.rc_pace_min_segs);
18307 	inp = rack->rc_inp;
18308 	to.to_flags = 0;
18309 	flags = tcp_outflags[tp->t_state];
18310 	if (flags & (TH_SYN|TH_RST)) {
18311 		goto failed;
18312 	}
18313 	if (rsm->r_flags & RACK_HAS_FIN) {
18314 		/* We can't send a FIN here */
18315 		goto failed;
18316 	}
18317 	if (flags & TH_FIN) {
18318 		/* We never send a FIN */
18319 		flags &= ~TH_FIN;
18320 	}
18321 	if (tp->t_flags & TF_RCVD_TSTMP) {
18322 		to.to_tsval = ms_cts + tp->ts_offset;
18323 		to.to_tsecr = tp->ts_recent;
18324 		to.to_flags = TOF_TS;
18325 	}
18326 #if defined(IPSEC_SUPPORT) || defined(TCP_SIGNATURE)
18327 	/* TCP-MD5 (RFC2385). */
18328 	if (tp->t_flags & TF_SIGNATURE)
18329 		to.to_flags |= TOF_SIGNATURE;
18330 #endif
18331 	optlen = tcp_addoptions(&to, opt);
18332 	hdrlen += optlen;
18333 	udp = rack->r_ctl.fsb.udp;
18334 	if (udp)
18335 		hdrlen += sizeof(struct udphdr);
18336 	if (rack->r_ctl.rc_pace_max_segs)
18337 		max_val = rack->r_ctl.rc_pace_max_segs;
18338 	else if (rack->rc_user_set_max_segs)
18339 		max_val = rack->rc_user_set_max_segs * segsiz;
18340 	else
18341 		max_val = len;
18342 	if ((tp->t_flags & TF_TSO) &&
18343 	    V_tcp_do_tso &&
18344 	    (len > segsiz) &&
18345 	    (tp->t_port == 0))
18346 		tso = 1;
18347 #ifdef INET6
18348 	if (MHLEN < hdrlen + max_linkhdr)
18349 		m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR);
18350 	else
18351 #endif
18352 		m = m_gethdr(M_NOWAIT, MT_DATA);
18353 	if (m == NULL)
18354 		goto failed;
18355 	m->m_data += max_linkhdr;
18356 	m->m_len = hdrlen;
18357 	th = rack->r_ctl.fsb.th;
18358 	/* Establish the len to send */
18359 	if (len > max_val)
18360 		len = max_val;
18361 	if ((tso) && (len + optlen > segsiz)) {
18362 		uint32_t if_hw_tsomax;
18363 		int32_t max_len;
18364 
18365 		/* extract TSO information */
18366 		if_hw_tsomax = tp->t_tsomax;
18367 		if_hw_tsomaxsegcount = tp->t_tsomaxsegcount;
18368 		if_hw_tsomaxsegsize = tp->t_tsomaxsegsize;
18369 		/*
18370 		 * Check if we should limit by maximum payload
18371 		 * length:
18372 		 */
18373 		if (if_hw_tsomax != 0) {
18374 			/* compute maximum TSO length */
18375 			max_len = (if_hw_tsomax - hdrlen -
18376 				   max_linkhdr);
18377 			if (max_len <= 0) {
18378 				goto failed;
18379 			} else if (len > max_len) {
18380 				len = max_len;
18381 			}
18382 		}
18383 		if (len <= segsiz) {
18384 			/*
18385 			 * In case there are too many small fragments don't
18386 			 * use TSO:
18387 			 */
18388 			tso = 0;
18389 		}
18390 	} else {
18391 		tso = 0;
18392 	}
18393 	if ((tso == 0) && (len > segsiz))
18394 		len = segsiz;
18395 	(void)tcp_get_usecs(tv);
18396 	if ((len == 0) ||
18397 	    (len <= MHLEN - hdrlen - max_linkhdr)) {
18398 		goto failed;
18399 	}
18400 	th->th_seq = htonl(rsm->r_start);
18401 	th->th_ack = htonl(tp->rcv_nxt);
18402 	/*
18403 	 * The PUSH bit should only be applied
18404 	 * if the full retransmission is made. If
18405 	 * we are sending less than this is the
18406 	 * left hand edge and should not have
18407 	 * the PUSH bit.
18408 	 */
18409 	if ((rsm->r_flags & RACK_HAD_PUSH) &&
18410 	    (len == (rsm->r_end - rsm->r_start)))
18411 		flags |= TH_PUSH;
18412 	th->th_win = htons((u_short)(rack->r_ctl.fsb.recwin >> tp->rcv_scale));
18413 	if (th->th_win == 0) {
18414 		tp->t_sndzerowin++;
18415 		tp->t_flags |= TF_RXWIN0SENT;
18416 	} else
18417 		tp->t_flags &= ~TF_RXWIN0SENT;
18418 	if (rsm->r_flags & RACK_TLP) {
18419 		/*
18420 		 * TLP should not count in retran count, but
18421 		 * in its own bin
18422 		 */
18423 		counter_u64_add(rack_tlp_retran, 1);
18424 		counter_u64_add(rack_tlp_retran_bytes, len);
18425 	} else {
18426 		tp->t_sndrexmitpack++;
18427 		KMOD_TCPSTAT_INC(tcps_sndrexmitpack);
18428 		KMOD_TCPSTAT_ADD(tcps_sndrexmitbyte, len);
18429 	}
18430 #ifdef STATS
18431 	stats_voi_update_abs_u32(tp->t_stats, VOI_TCP_RETXPB,
18432 				 len);
18433 #endif
18434 	if (rsm->m == NULL)
18435 		goto failed;
18436 	if (rsm->m &&
18437 	    ((rsm->orig_m_len != rsm->m->m_len) ||
18438 	     (M_TRAILINGROOM(rsm->m) != rsm->orig_t_space))) {
18439 		/* Fix up the orig_m_len and possibly the mbuf offset */
18440 		rack_adjust_orig_mlen(rsm);
18441 	}
18442 	m->m_next = rack_fo_base_copym(rsm->m, rsm->soff, &len, NULL, if_hw_tsomaxsegcount, if_hw_tsomaxsegsize, rsm->r_hw_tls);
18443 	if (len <= segsiz) {
18444 		/*
18445 		 * Must have ran out of mbufs for the copy
18446 		 * shorten it to no longer need tso. Lets
18447 		 * not put on sendalot since we are low on
18448 		 * mbufs.
18449 		 */
18450 		tso = 0;
18451 	}
18452 	if ((m->m_next == NULL) || (len <= 0)){
18453 		goto failed;
18454 	}
18455 	if (udp) {
18456 		if (rack->r_is_v6)
18457 			ulen = hdrlen + len - sizeof(struct ip6_hdr);
18458 		else
18459 			ulen = hdrlen + len - sizeof(struct ip);
18460 		udp->uh_ulen = htons(ulen);
18461 	}
18462 	m->m_pkthdr.rcvif = (struct ifnet *)0;
18463 	if (TCPS_HAVERCVDSYN(tp->t_state) &&
18464 	    (tp->t_flags2 & (TF2_ECN_PERMIT | TF2_ACE_PERMIT))) {
18465 		int ect = tcp_ecn_output_established(tp, &flags, len, true);
18466 		if ((tp->t_state == TCPS_SYN_RECEIVED) &&
18467 		    (tp->t_flags2 & TF2_ECN_SND_ECE))
18468 		    tp->t_flags2 &= ~TF2_ECN_SND_ECE;
18469 #ifdef INET6
18470 		if (rack->r_is_v6) {
18471 		    ip6->ip6_flow &= ~htonl(IPTOS_ECN_MASK << 20);
18472 		    ip6->ip6_flow |= htonl(ect << 20);
18473 		}
18474 		else
18475 #endif
18476 		{
18477 		    ip->ip_tos &= ~IPTOS_ECN_MASK;
18478 		    ip->ip_tos |= ect;
18479 		}
18480 	}
18481 	if (rack->r_ctl.crte != NULL) {
18482 		/* See if we can send via the hw queue */
18483 		pacing_delay = rack_check_queue_level(rack, tp, tv, cts, len, segsiz);
18484 		/* If there is nothing in queue (no pacing time) we can send via the hw queue */
18485 		if (pacing_delay == 0)
18486 			ip_sendflag = 0;
18487 	}
18488 	tcp_set_flags(th, flags);
18489 	m->m_pkthdr.len = hdrlen + len;	/* in6_cksum() need this */
18490 #if defined(IPSEC_SUPPORT) || defined(TCP_SIGNATURE)
18491 	if (to.to_flags & TOF_SIGNATURE) {
18492 		/*
18493 		 * Calculate MD5 signature and put it into the place
18494 		 * determined before.
18495 		 * NOTE: since TCP options buffer doesn't point into
18496 		 * mbuf's data, calculate offset and use it.
18497 		 */
18498 		if (!TCPMD5_ENABLED() || TCPMD5_OUTPUT(m, th,
18499 						       (u_char *)(th + 1) + (to.to_signature - opt)) != 0) {
18500 			/*
18501 			 * Do not send segment if the calculation of MD5
18502 			 * digest has failed.
18503 			 */
18504 			goto failed;
18505 		}
18506 	}
18507 #endif
18508 #ifdef INET6
18509 	if (rack->r_is_v6) {
18510 		if (tp->t_port) {
18511 			m->m_pkthdr.csum_flags = CSUM_UDP_IPV6;
18512 			m->m_pkthdr.csum_data = offsetof(struct udphdr, uh_sum);
18513 			udp->uh_sum = in6_cksum_pseudo(ip6, ulen, IPPROTO_UDP, 0);
18514 			th->th_sum = htons(0);
18515 			UDPSTAT_INC(udps_opackets);
18516 		} else {
18517 			m->m_pkthdr.csum_flags = CSUM_TCP_IPV6;
18518 			m->m_pkthdr.csum_data = offsetof(struct tcphdr, th_sum);
18519 			th->th_sum = in6_cksum_pseudo(ip6,
18520 						      sizeof(struct tcphdr) + optlen + len, IPPROTO_TCP,
18521 						      0);
18522 		}
18523 	}
18524 #endif
18525 #if defined(INET6) && defined(INET)
18526 	else
18527 #endif
18528 #ifdef INET
18529 	{
18530 		if (tp->t_port) {
18531 			m->m_pkthdr.csum_flags = CSUM_UDP;
18532 			m->m_pkthdr.csum_data = offsetof(struct udphdr, uh_sum);
18533 			udp->uh_sum = in_pseudo(ip->ip_src.s_addr,
18534 						ip->ip_dst.s_addr, htons(ulen + IPPROTO_UDP));
18535 			th->th_sum = htons(0);
18536 			UDPSTAT_INC(udps_opackets);
18537 		} else {
18538 			m->m_pkthdr.csum_flags = CSUM_TCP;
18539 			m->m_pkthdr.csum_data = offsetof(struct tcphdr, th_sum);
18540 			th->th_sum = in_pseudo(ip->ip_src.s_addr,
18541 					       ip->ip_dst.s_addr, htons(sizeof(struct tcphdr) +
18542 									IPPROTO_TCP + len + optlen));
18543 		}
18544 		/* IP version must be set here for ipv4/ipv6 checking later */
18545 		KASSERT(ip->ip_v == IPVERSION,
18546 			("%s: IP version incorrect: %d", __func__, ip->ip_v));
18547 	}
18548 #endif
18549 	if (tso) {
18550 		/*
18551 		 * Here we use segsiz since we have no added options besides
18552 		 * any standard timestamp options (no DSACKs or SACKS are sent
18553 		 * via either fast-path).
18554 		 */
18555 		KASSERT(len > segsiz,
18556 			("%s: len <= tso_segsz tp:%p", __func__, tp));
18557 		m->m_pkthdr.csum_flags |= CSUM_TSO;
18558 		m->m_pkthdr.tso_segsz = segsiz;
18559 	}
18560 #ifdef INET6
18561 	if (rack->r_is_v6) {
18562 		ip6->ip6_hlim = rack->r_ctl.fsb.hoplimit;
18563 		ip6->ip6_plen = htons(m->m_pkthdr.len - sizeof(*ip6));
18564 		if (V_path_mtu_discovery && tp->t_maxseg > V_tcp_minmss)
18565 			tp->t_flags2 |= TF2_PLPMTU_PMTUD;
18566 		else
18567 			tp->t_flags2 &= ~TF2_PLPMTU_PMTUD;
18568 	}
18569 #endif
18570 #if defined(INET) && defined(INET6)
18571 	else
18572 #endif
18573 #ifdef INET
18574 	{
18575 		ip->ip_len = htons(m->m_pkthdr.len);
18576 		ip->ip_ttl = rack->r_ctl.fsb.hoplimit;
18577 		if (V_path_mtu_discovery && tp->t_maxseg > V_tcp_minmss) {
18578 			tp->t_flags2 |= TF2_PLPMTU_PMTUD;
18579 			if (tp->t_port == 0 || len < V_tcp_minmss) {
18580 				ip->ip_off |= htons(IP_DF);
18581 			}
18582 		} else {
18583 			tp->t_flags2 &= ~TF2_PLPMTU_PMTUD;
18584 		}
18585 	}
18586 #endif
18587 	if (doing_tlp == 0) {
18588 		/* Set we retransmitted */
18589 		rack->rc_gp_saw_rec = 1;
18590 	} else {
18591 		/* Its a TLP set ca or ss */
18592 		if (tp->snd_cwnd > tp->snd_ssthresh) {
18593 			/* Set we sent in CA */
18594 			rack->rc_gp_saw_ca = 1;
18595 		} else {
18596 			/* Set we sent in SS */
18597 			rack->rc_gp_saw_ss = 1;
18598 		}
18599 	}
18600 	/* Time to copy in our header */
18601 	cpto = mtod(m, uint8_t *);
18602 	memcpy(cpto, rack->r_ctl.fsb.tcp_ip_hdr, rack->r_ctl.fsb.tcp_ip_hdr_len);
18603 	th = (struct tcphdr *)(cpto + ((uint8_t *)rack->r_ctl.fsb.th - rack->r_ctl.fsb.tcp_ip_hdr));
18604 	if (optlen) {
18605 		bcopy(opt, th + 1, optlen);
18606 		th->th_off = (sizeof(struct tcphdr) + optlen) >> 2;
18607 	} else {
18608 		th->th_off = sizeof(struct tcphdr) >> 2;
18609 	}
18610 	if (tcp_bblogging_on(rack->rc_tp)) {
18611 		union tcp_log_stackspecific log;
18612 
18613 		if (rsm->r_flags & RACK_RWND_COLLAPSED) {
18614 			rack_log_collapse(rack, rsm->r_start, rsm->r_end, 0, __LINE__, 5, rsm->r_flags, rsm);
18615 			counter_u64_add(rack_collapsed_win_rxt, 1);
18616 			counter_u64_add(rack_collapsed_win_rxt_bytes, (rsm->r_end - rsm->r_start));
18617 		}
18618 		memset(&log, 0, sizeof(log));
18619 		log.u_bbr.inhpts = tcp_in_hpts(rack->rc_tp);
18620 		if (rack->rack_no_prr)
18621 			log.u_bbr.flex1 = 0;
18622 		else
18623 			log.u_bbr.flex1 = rack->r_ctl.rc_prr_sndcnt;
18624 		log.u_bbr.flex2 = rack->r_ctl.rc_pace_min_segs;
18625 		log.u_bbr.flex3 = rack->r_ctl.rc_pace_max_segs;
18626 		log.u_bbr.flex4 = max_val;
18627 		/* Save off the early/late values */
18628 		log.u_bbr.flex6 = rack->r_ctl.rc_agg_early;
18629 		log.u_bbr.applimited = rack->r_ctl.rc_agg_delayed;
18630 		log.u_bbr.bw_inuse = rack_get_bw(rack);
18631 		log.u_bbr.cur_del_rate = rack->r_ctl.gp_bw;
18632 		if (doing_tlp == 0)
18633 			log.u_bbr.flex8 = 1;
18634 		else
18635 			log.u_bbr.flex8 = 2;
18636 		log.u_bbr.pacing_gain = rack_get_output_gain(rack, NULL);
18637 		log.u_bbr.flex7 = 55;
18638 		log.u_bbr.pkts_out = tp->t_maxseg;
18639 		log.u_bbr.timeStamp = cts;
18640 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
18641 		if (rsm->r_rtr_cnt > 0) {
18642 			/*
18643 			 * When we have a retransmit we want to log the
18644 			 * burst at send and flight at send from before.
18645 			 */
18646 			log.u_bbr.flex5 = rsm->r_fas;
18647 			log.u_bbr.bbr_substate = rsm->r_bas;
18648 		} else {
18649 			/*
18650 			 * This is currently unlikely until we do the
18651 			 * packet pair probes but I will add it for completeness.
18652 			 */
18653 			log.u_bbr.flex5 = log.u_bbr.inflight;
18654 			log.u_bbr.bbr_substate = (uint8_t)((len + segsiz - 1)/segsiz);
18655 		}
18656 		log.u_bbr.lt_epoch = rack->r_ctl.cwnd_to_use;
18657 		log.u_bbr.delivered = 0;
18658 		log.u_bbr.rttProp = (uintptr_t)rsm;
18659 		log.u_bbr.delRate = rsm->r_flags;
18660 		log.u_bbr.delRate <<= 31;
18661 		log.u_bbr.delRate |= rack->r_must_retran;
18662 		log.u_bbr.delRate <<= 1;
18663 		log.u_bbr.delRate |= 1;
18664 		log.u_bbr.pkt_epoch = __LINE__;
18665 		lgb = tcp_log_event(tp, th, NULL, NULL, TCP_LOG_OUT, ERRNO_UNK,
18666 				     len, &log, false, NULL, __func__, __LINE__, tv);
18667 	} else
18668 		lgb = NULL;
18669 	if ((rack->r_ctl.crte != NULL) &&
18670 	    tcp_bblogging_on(tp)) {
18671 		rack_log_queue_level(tp, rack, len, tv, cts);
18672 	}
18673 #ifdef INET6
18674 	if (rack->r_is_v6) {
18675 		error = ip6_output(m, inp->in6p_outputopts,
18676 				   &inp->inp_route6,
18677 				   ip_sendflag, NULL, NULL, inp);
18678 	}
18679 	else
18680 #endif
18681 #ifdef INET
18682 	{
18683 		error = ip_output(m, NULL,
18684 				  &inp->inp_route,
18685 				  ip_sendflag, 0, inp);
18686 	}
18687 #endif
18688 	m = NULL;
18689 	if (lgb) {
18690 		lgb->tlb_errno = error;
18691 		lgb = NULL;
18692 	}
18693 	/* Move snd_nxt to snd_max so we don't have false retransmissions */
18694 	tp->snd_nxt = tp->snd_max;
18695 	if (error) {
18696 		goto failed;
18697 	} else if (rack->rc_hw_nobuf && (ip_sendflag != IP_NO_SND_TAG_RL)) {
18698 		rack->rc_hw_nobuf = 0;
18699 		rack->r_ctl.rc_agg_delayed = 0;
18700 		rack->r_early = 0;
18701 		rack->r_late = 0;
18702 		rack->r_ctl.rc_agg_early = 0;
18703 	}
18704 	rack_log_output(tp, &to, len, rsm->r_start, flags, error, rack_to_usec_ts(tv),
18705 			rsm, RACK_SENT_FP, rsm->m, rsm->soff, rsm->r_hw_tls, segsiz);
18706 	if (doing_tlp) {
18707 		rack->rc_tlp_in_progress = 1;
18708 		rack->r_ctl.rc_tlp_cnt_out++;
18709 	}
18710 	if (error == 0) {
18711 		counter_u64_add(rack_total_bytes, len);
18712 		tcp_account_for_send(tp, len, 1, doing_tlp, rsm->r_hw_tls);
18713 		if (doing_tlp) {
18714 			rack->rc_last_sent_tlp_past_cumack = 0;
18715 			rack->rc_last_sent_tlp_seq_valid = 1;
18716 			rack->r_ctl.last_sent_tlp_seq = rsm->r_start;
18717 			rack->r_ctl.last_sent_tlp_len = rsm->r_end - rsm->r_start;
18718 		}
18719 		if (rack->r_ctl.rc_prr_sndcnt >= len)
18720 			rack->r_ctl.rc_prr_sndcnt -= len;
18721 		else
18722 			rack->r_ctl.rc_prr_sndcnt = 0;
18723 	}
18724 	tp->t_flags &= ~(TF_ACKNOW | TF_DELACK);
18725 	rack->forced_ack = 0;	/* If we send something zap the FA flag */
18726 	if (IN_FASTRECOVERY(tp->t_flags) && rsm)
18727 		rack->r_ctl.retran_during_recovery += len;
18728 	{
18729 		int idx;
18730 
18731 		idx = (len / segsiz) + 3;
18732 		if (idx >= TCP_MSS_ACCT_ATIMER)
18733 			counter_u64_add(rack_out_size[(TCP_MSS_ACCT_ATIMER-1)], 1);
18734 		else
18735 			counter_u64_add(rack_out_size[idx], 1);
18736 	}
18737 	if (tp->t_rtttime == 0) {
18738 		tp->t_rtttime = ticks;
18739 		tp->t_rtseq = startseq;
18740 		KMOD_TCPSTAT_INC(tcps_segstimed);
18741 	}
18742 	counter_u64_add(rack_fto_rsm_send, 1);
18743 	if (error && (error == ENOBUFS)) {
18744 		if (rack->r_ctl.crte != NULL) {
18745 			tcp_trace_point(rack->rc_tp, TCP_TP_HWENOBUF);
18746 			if (tcp_bblogging_on(rack->rc_tp))
18747 				rack_log_queue_level(tp, rack, len, tv, cts);
18748 		} else
18749 			tcp_trace_point(rack->rc_tp, TCP_TP_ENOBUF);
18750 		pacing_delay = ((1 + rack->rc_enobuf) * HPTS_USEC_IN_MSEC);
18751 		if (rack->rc_enobuf < 0x7f)
18752 			rack->rc_enobuf++;
18753 		if (pacing_delay < (10 * HPTS_USEC_IN_MSEC))
18754 			pacing_delay = 10 * HPTS_USEC_IN_MSEC;
18755 		if (rack->r_ctl.crte != NULL) {
18756 			counter_u64_add(rack_saw_enobuf_hw, 1);
18757 			tcp_rl_log_enobuf(rack->r_ctl.crte);
18758 		}
18759 		counter_u64_add(rack_saw_enobuf, 1);
18760 	} else {
18761 		pacing_delay = rack_get_pacing_delay(rack, tp, len, NULL, segsiz, __LINE__);
18762 	}
18763 	rack_start_hpts_timer(rack, tp, cts, pacing_delay, len, 0);
18764 #ifdef TCP_ACCOUNTING
18765 	crtsc = get_cyclecount();
18766 	if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
18767 		tp->tcp_cnt_counters[SND_OUT_DATA] += cnt_thru;
18768 		tp->tcp_proc_time[SND_OUT_DATA] += (crtsc - ts_val);
18769 		tp->tcp_cnt_counters[CNT_OF_MSS_OUT] += ((len + segsiz - 1) / segsiz);
18770 	}
18771 	sched_unpin();
18772 #endif
18773 	return (0);
18774 failed:
18775 	if (m)
18776 		m_free(m);
18777 	return (-1);
18778 }
18779 
18780 static void
18781 rack_sndbuf_autoscale(struct tcp_rack *rack)
18782 {
18783 	/*
18784 	 * Automatic sizing of send socket buffer.  Often the send buffer
18785 	 * size is not optimally adjusted to the actual network conditions
18786 	 * at hand (delay bandwidth product).  Setting the buffer size too
18787 	 * small limits throughput on links with high bandwidth and high
18788 	 * delay (eg. trans-continental/oceanic links).  Setting the
18789 	 * buffer size too big consumes too much real kernel memory,
18790 	 * especially with many connections on busy servers.
18791 	 *
18792 	 * The criteria to step up the send buffer one notch are:
18793 	 *  1. receive window of remote host is larger than send buffer
18794 	 *     (with a fudge factor of 5/4th);
18795 	 *  2. send buffer is filled to 7/8th with data (so we actually
18796 	 *     have data to make use of it);
18797 	 *  3. send buffer fill has not hit maximal automatic size;
18798 	 *  4. our send window (slow start and cogestion controlled) is
18799 	 *     larger than sent but unacknowledged data in send buffer.
18800 	 *
18801 	 * Note that the rack version moves things much faster since
18802 	 * we want to avoid hitting cache lines in the rack_fast_output()
18803 	 * path so this is called much less often and thus moves
18804 	 * the SB forward by a percentage.
18805 	 */
18806 	struct socket *so;
18807 	struct tcpcb *tp;
18808 	uint32_t sendwin, scaleup;
18809 
18810 	tp = rack->rc_tp;
18811 	so = rack->rc_inp->inp_socket;
18812 	sendwin = min(rack->r_ctl.cwnd_to_use, tp->snd_wnd);
18813 	if (V_tcp_do_autosndbuf && so->so_snd.sb_flags & SB_AUTOSIZE) {
18814 		if ((tp->snd_wnd / 4 * 5) >= so->so_snd.sb_hiwat &&
18815 		    sbused(&so->so_snd) >=
18816 		    (so->so_snd.sb_hiwat / 8 * 7) &&
18817 		    sbused(&so->so_snd) < V_tcp_autosndbuf_max &&
18818 		    sendwin >= (sbused(&so->so_snd) -
18819 		    (tp->snd_max - tp->snd_una))) {
18820 			if (rack_autosndbuf_inc)
18821 				scaleup = (rack_autosndbuf_inc * so->so_snd.sb_hiwat) / 100;
18822 			else
18823 				scaleup = V_tcp_autosndbuf_inc;
18824 			if (scaleup < V_tcp_autosndbuf_inc)
18825 				scaleup = V_tcp_autosndbuf_inc;
18826 			scaleup += so->so_snd.sb_hiwat;
18827 			if (scaleup > V_tcp_autosndbuf_max)
18828 				scaleup = V_tcp_autosndbuf_max;
18829 			if (!sbreserve_locked(so, SO_SND, scaleup, curthread))
18830 				so->so_snd.sb_flags &= ~SB_AUTOSIZE;
18831 		}
18832 	}
18833 }
18834 
18835 static int
18836 rack_fast_output(struct tcpcb *tp, struct tcp_rack *rack, uint64_t ts_val,
18837 		 uint32_t cts, uint32_t ms_cts, struct timeval *tv, long *tot_len, int *send_err, int line)
18838 {
18839 	/*
18840 	 * Enter to do fast output. We are given that the sched_pin is
18841 	 * in place (if accounting is compiled in) and the cycle count taken
18842 	 * at entry is in place in ts_val. The idea here is that
18843 	 * we know how many more bytes needs to be sent (presumably either
18844 	 * during pacing or to fill the cwnd and that was greater than
18845 	 * the max-burst). We have how much to send and all the info we
18846 	 * need to just send.
18847 	 */
18848 #ifdef INET
18849 	struct ip *ip = NULL;
18850 #endif
18851 	struct udphdr *udp = NULL;
18852 	struct tcphdr *th = NULL;
18853 	struct mbuf *m, *s_mb;
18854 	struct inpcb *inp;
18855 	uint8_t *cpto;
18856 	struct tcp_log_buffer *lgb;
18857 #ifdef TCP_ACCOUNTING
18858 	uint64_t crtsc;
18859 #endif
18860 	struct tcpopt to;
18861 	u_char opt[TCP_MAXOLEN];
18862 	uint32_t hdrlen, optlen;
18863 #ifdef TCP_ACCOUNTING
18864 	int cnt_thru = 1;
18865 #endif
18866 	int32_t pacing_delay, segsiz, len, max_val, tso = 0, sb_offset, error, ulen = 0;
18867 	uint16_t flags;
18868 	uint32_t s_soff;
18869 	uint32_t if_hw_tsomaxsegcount = 0, startseq;
18870 	uint32_t if_hw_tsomaxsegsize;
18871 	uint32_t add_flag = RACK_SENT_FP;
18872 #ifdef INET6
18873 	struct ip6_hdr *ip6 = NULL;
18874 
18875 	if (rack->r_is_v6) {
18876 		ip6 = (struct ip6_hdr *)rack->r_ctl.fsb.tcp_ip_hdr;
18877 		hdrlen = sizeof(struct ip6_hdr) + sizeof(struct tcphdr);
18878 	} else
18879 #endif				/* INET6 */
18880 	{
18881 #ifdef INET
18882 		ip = (struct ip *)rack->r_ctl.fsb.tcp_ip_hdr;
18883 		hdrlen = sizeof(struct tcpiphdr);
18884 #endif
18885 	}
18886 	if (tp->t_port && (V_tcp_udp_tunneling_port == 0)) {
18887 		m = NULL;
18888 		goto failed;
18889 	}
18890 	rack->r_ctl.cwnd_to_use = tp->snd_cwnd;
18891 	startseq = tp->snd_max;
18892 	segsiz = min(ctf_fixed_maxseg(tp), rack->r_ctl.rc_pace_min_segs);
18893 	inp = rack->rc_inp;
18894 	len = rack->r_ctl.fsb.left_to_send;
18895 	to.to_flags = 0;
18896 	flags = rack->r_ctl.fsb.tcp_flags;
18897 	if (tp->t_flags & TF_RCVD_TSTMP) {
18898 		to.to_tsval = ms_cts + tp->ts_offset;
18899 		to.to_tsecr = tp->ts_recent;
18900 		to.to_flags = TOF_TS;
18901 	}
18902 #if defined(IPSEC_SUPPORT) || defined(TCP_SIGNATURE)
18903 	/* TCP-MD5 (RFC2385). */
18904 	if (tp->t_flags & TF_SIGNATURE)
18905 		to.to_flags |= TOF_SIGNATURE;
18906 #endif
18907 	optlen = tcp_addoptions(&to, opt);
18908 	hdrlen += optlen;
18909 	udp = rack->r_ctl.fsb.udp;
18910 	if (udp)
18911 		hdrlen += sizeof(struct udphdr);
18912 	if (rack->r_ctl.rc_pace_max_segs)
18913 		max_val = rack->r_ctl.rc_pace_max_segs;
18914 	else if (rack->rc_user_set_max_segs)
18915 		max_val = rack->rc_user_set_max_segs * segsiz;
18916 	else
18917 		max_val = len;
18918 	if ((tp->t_flags & TF_TSO) &&
18919 	    V_tcp_do_tso &&
18920 	    (len > segsiz) &&
18921 	    (tp->t_port == 0))
18922 		tso = 1;
18923 again:
18924 #ifdef INET6
18925 	if (MHLEN < hdrlen + max_linkhdr)
18926 		m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR);
18927 	else
18928 #endif
18929 		m = m_gethdr(M_NOWAIT, MT_DATA);
18930 	if (m == NULL)
18931 		goto failed;
18932 	m->m_data += max_linkhdr;
18933 	m->m_len = hdrlen;
18934 	th = rack->r_ctl.fsb.th;
18935 	/* Establish the len to send */
18936 	if (len > max_val)
18937 		len = max_val;
18938 	if ((tso) && (len + optlen > segsiz)) {
18939 		uint32_t if_hw_tsomax;
18940 		int32_t max_len;
18941 
18942 		/* extract TSO information */
18943 		if_hw_tsomax = tp->t_tsomax;
18944 		if_hw_tsomaxsegcount = tp->t_tsomaxsegcount;
18945 		if_hw_tsomaxsegsize = tp->t_tsomaxsegsize;
18946 		/*
18947 		 * Check if we should limit by maximum payload
18948 		 * length:
18949 		 */
18950 		if (if_hw_tsomax != 0) {
18951 			/* compute maximum TSO length */
18952 			max_len = (if_hw_tsomax - hdrlen -
18953 				   max_linkhdr);
18954 			if (max_len <= 0) {
18955 				goto failed;
18956 			} else if (len > max_len) {
18957 				len = max_len;
18958 			}
18959 		}
18960 		if (len <= segsiz) {
18961 			/*
18962 			 * In case there are too many small fragments don't
18963 			 * use TSO:
18964 			 */
18965 			tso = 0;
18966 		}
18967 	} else {
18968 		tso = 0;
18969 	}
18970 	if ((tso == 0) && (len > segsiz))
18971 		len = segsiz;
18972 	(void)tcp_get_usecs(tv);
18973 	if ((len == 0) ||
18974 	    (len <= MHLEN - hdrlen - max_linkhdr)) {
18975 		goto failed;
18976 	}
18977 	sb_offset = tp->snd_max - tp->snd_una;
18978 	th->th_seq = htonl(tp->snd_max);
18979 	th->th_ack = htonl(tp->rcv_nxt);
18980 	th->th_win = htons((u_short)(rack->r_ctl.fsb.recwin >> tp->rcv_scale));
18981 	if (th->th_win == 0) {
18982 		tp->t_sndzerowin++;
18983 		tp->t_flags |= TF_RXWIN0SENT;
18984 	} else
18985 		tp->t_flags &= ~TF_RXWIN0SENT;
18986 	tp->snd_up = tp->snd_una;	/* drag it along, its deprecated */
18987 	KMOD_TCPSTAT_INC(tcps_sndpack);
18988 	KMOD_TCPSTAT_ADD(tcps_sndbyte, len);
18989 #ifdef STATS
18990 	stats_voi_update_abs_u64(tp->t_stats, VOI_TCP_TXPB,
18991 				 len);
18992 #endif
18993 	if (rack->r_ctl.fsb.m == NULL)
18994 		goto failed;
18995 
18996 	/* s_mb and s_soff are saved for rack_log_output */
18997 	m->m_next = rack_fo_m_copym(rack, &len, if_hw_tsomaxsegcount, if_hw_tsomaxsegsize,
18998 				    &s_mb, &s_soff);
18999 	if (len <= segsiz) {
19000 		/*
19001 		 * Must have ran out of mbufs for the copy
19002 		 * shorten it to no longer need tso. Lets
19003 		 * not put on sendalot since we are low on
19004 		 * mbufs.
19005 		 */
19006 		tso = 0;
19007 	}
19008 	if (rack->r_ctl.fsb.rfo_apply_push &&
19009 	    (len == rack->r_ctl.fsb.left_to_send)) {
19010 		flags |= TH_PUSH;
19011 		add_flag |= RACK_HAD_PUSH;
19012 	}
19013 	if ((m->m_next == NULL) || (len <= 0)){
19014 		goto failed;
19015 	}
19016 	if (udp) {
19017 		if (rack->r_is_v6)
19018 			ulen = hdrlen + len - sizeof(struct ip6_hdr);
19019 		else
19020 			ulen = hdrlen + len - sizeof(struct ip);
19021 		udp->uh_ulen = htons(ulen);
19022 	}
19023 	m->m_pkthdr.rcvif = (struct ifnet *)0;
19024 	if (TCPS_HAVERCVDSYN(tp->t_state) &&
19025 	    (tp->t_flags2 & (TF2_ECN_PERMIT | TF2_ACE_PERMIT))) {
19026 		int ect = tcp_ecn_output_established(tp, &flags, len, false);
19027 		if ((tp->t_state == TCPS_SYN_RECEIVED) &&
19028 		    (tp->t_flags2 & TF2_ECN_SND_ECE))
19029 			tp->t_flags2 &= ~TF2_ECN_SND_ECE;
19030 #ifdef INET6
19031 		if (rack->r_is_v6) {
19032 			ip6->ip6_flow &= ~htonl(IPTOS_ECN_MASK << 20);
19033 			ip6->ip6_flow |= htonl(ect << 20);
19034 		}
19035 		else
19036 #endif
19037 		{
19038 #ifdef INET
19039 			ip->ip_tos &= ~IPTOS_ECN_MASK;
19040 			ip->ip_tos |= ect;
19041 #endif
19042 		}
19043 	}
19044 	tcp_set_flags(th, flags);
19045 	m->m_pkthdr.len = hdrlen + len;	/* in6_cksum() need this */
19046 #if defined(IPSEC_SUPPORT) || defined(TCP_SIGNATURE)
19047 	if (to.to_flags & TOF_SIGNATURE) {
19048 		/*
19049 		 * Calculate MD5 signature and put it into the place
19050 		 * determined before.
19051 		 * NOTE: since TCP options buffer doesn't point into
19052 		 * mbuf's data, calculate offset and use it.
19053 		 */
19054 		if (!TCPMD5_ENABLED() || TCPMD5_OUTPUT(m, th,
19055 						       (u_char *)(th + 1) + (to.to_signature - opt)) != 0) {
19056 			/*
19057 			 * Do not send segment if the calculation of MD5
19058 			 * digest has failed.
19059 			 */
19060 			goto failed;
19061 		}
19062 	}
19063 #endif
19064 #ifdef INET6
19065 	if (rack->r_is_v6) {
19066 		if (tp->t_port) {
19067 			m->m_pkthdr.csum_flags = CSUM_UDP_IPV6;
19068 			m->m_pkthdr.csum_data = offsetof(struct udphdr, uh_sum);
19069 			udp->uh_sum = in6_cksum_pseudo(ip6, ulen, IPPROTO_UDP, 0);
19070 			th->th_sum = htons(0);
19071 			UDPSTAT_INC(udps_opackets);
19072 		} else {
19073 			m->m_pkthdr.csum_flags = CSUM_TCP_IPV6;
19074 			m->m_pkthdr.csum_data = offsetof(struct tcphdr, th_sum);
19075 			th->th_sum = in6_cksum_pseudo(ip6,
19076 						      sizeof(struct tcphdr) + optlen + len, IPPROTO_TCP,
19077 						      0);
19078 		}
19079 	}
19080 #endif
19081 #if defined(INET6) && defined(INET)
19082 	else
19083 #endif
19084 #ifdef INET
19085 	{
19086 		if (tp->t_port) {
19087 			m->m_pkthdr.csum_flags = CSUM_UDP;
19088 			m->m_pkthdr.csum_data = offsetof(struct udphdr, uh_sum);
19089 			udp->uh_sum = in_pseudo(ip->ip_src.s_addr,
19090 						ip->ip_dst.s_addr, htons(ulen + IPPROTO_UDP));
19091 			th->th_sum = htons(0);
19092 			UDPSTAT_INC(udps_opackets);
19093 		} else {
19094 			m->m_pkthdr.csum_flags = CSUM_TCP;
19095 			m->m_pkthdr.csum_data = offsetof(struct tcphdr, th_sum);
19096 			th->th_sum = in_pseudo(ip->ip_src.s_addr,
19097 					       ip->ip_dst.s_addr, htons(sizeof(struct tcphdr) +
19098 									IPPROTO_TCP + len + optlen));
19099 		}
19100 		/* IP version must be set here for ipv4/ipv6 checking later */
19101 		KASSERT(ip->ip_v == IPVERSION,
19102 			("%s: IP version incorrect: %d", __func__, ip->ip_v));
19103 	}
19104 #endif
19105 	if (tso) {
19106 		/*
19107 		 * Here we use segsiz since we have no added options besides
19108 		 * any standard timestamp options (no DSACKs or SACKS are sent
19109 		 * via either fast-path).
19110 		 */
19111 		KASSERT(len > segsiz,
19112 			("%s: len <= tso_segsz tp:%p", __func__, tp));
19113 		m->m_pkthdr.csum_flags |= CSUM_TSO;
19114 		m->m_pkthdr.tso_segsz = segsiz;
19115 	}
19116 #ifdef INET6
19117 	if (rack->r_is_v6) {
19118 		ip6->ip6_hlim = rack->r_ctl.fsb.hoplimit;
19119 		ip6->ip6_plen = htons(m->m_pkthdr.len - sizeof(*ip6));
19120 		if (V_path_mtu_discovery && tp->t_maxseg > V_tcp_minmss)
19121 			tp->t_flags2 |= TF2_PLPMTU_PMTUD;
19122 		else
19123 			tp->t_flags2 &= ~TF2_PLPMTU_PMTUD;
19124 	}
19125 #endif
19126 #if defined(INET) && defined(INET6)
19127 	else
19128 #endif
19129 #ifdef INET
19130 	{
19131 		ip->ip_len = htons(m->m_pkthdr.len);
19132 		ip->ip_ttl = rack->r_ctl.fsb.hoplimit;
19133 		if (V_path_mtu_discovery && tp->t_maxseg > V_tcp_minmss) {
19134 			tp->t_flags2 |= TF2_PLPMTU_PMTUD;
19135 			if (tp->t_port == 0 || len < V_tcp_minmss) {
19136 				ip->ip_off |= htons(IP_DF);
19137 			}
19138 		} else {
19139 			tp->t_flags2 &= ~TF2_PLPMTU_PMTUD;
19140 		}
19141 	}
19142 #endif
19143 	if (tp->snd_cwnd > tp->snd_ssthresh) {
19144 		/* Set we sent in CA */
19145 		rack->rc_gp_saw_ca = 1;
19146 	} else {
19147 		/* Set we sent in SS */
19148 		rack->rc_gp_saw_ss = 1;
19149 	}
19150 	/* Time to copy in our header */
19151 	cpto = mtod(m, uint8_t *);
19152 	memcpy(cpto, rack->r_ctl.fsb.tcp_ip_hdr, rack->r_ctl.fsb.tcp_ip_hdr_len);
19153 	th = (struct tcphdr *)(cpto + ((uint8_t *)rack->r_ctl.fsb.th - rack->r_ctl.fsb.tcp_ip_hdr));
19154 	if (optlen) {
19155 		bcopy(opt, th + 1, optlen);
19156 		th->th_off = (sizeof(struct tcphdr) + optlen) >> 2;
19157 	} else {
19158 		th->th_off = sizeof(struct tcphdr) >> 2;
19159 	}
19160 	if ((rack->r_ctl.crte != NULL) &&
19161 	    tcp_bblogging_on(tp)) {
19162 		rack_log_queue_level(tp, rack, len, tv, cts);
19163 	}
19164 	if (tcp_bblogging_on(rack->rc_tp)) {
19165 		union tcp_log_stackspecific log;
19166 
19167 		memset(&log, 0, sizeof(log));
19168 		log.u_bbr.inhpts = tcp_in_hpts(rack->rc_tp);
19169 		if (rack->rack_no_prr)
19170 			log.u_bbr.flex1 = 0;
19171 		else
19172 			log.u_bbr.flex1 = rack->r_ctl.rc_prr_sndcnt;
19173 		log.u_bbr.flex2 = rack->r_ctl.rc_pace_min_segs;
19174 		log.u_bbr.flex3 = rack->r_ctl.rc_pace_max_segs;
19175 		log.u_bbr.flex4 = max_val;
19176 		/* Save off the early/late values */
19177 		log.u_bbr.flex6 = rack->r_ctl.rc_agg_early;
19178 		log.u_bbr.applimited = rack->r_ctl.rc_agg_delayed;
19179 		log.u_bbr.bw_inuse = rack_get_bw(rack);
19180 		log.u_bbr.cur_del_rate = rack->r_ctl.gp_bw;
19181 		log.u_bbr.flex8 = 0;
19182 		log.u_bbr.pacing_gain = rack_get_output_gain(rack, NULL);
19183 		log.u_bbr.flex7 = 44;
19184 		log.u_bbr.pkts_out = tp->t_maxseg;
19185 		log.u_bbr.timeStamp = cts;
19186 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
19187 		log.u_bbr.flex5 = log.u_bbr.inflight;
19188 		log.u_bbr.lt_epoch = rack->r_ctl.cwnd_to_use;
19189 		log.u_bbr.delivered = rack->r_ctl.fsb.left_to_send;
19190 		log.u_bbr.rttProp = 0;
19191 		log.u_bbr.delRate = rack->r_must_retran;
19192 		log.u_bbr.delRate <<= 1;
19193 		log.u_bbr.pkt_epoch = line;
19194 		/* For fast output no retrans so just inflight and how many mss we send */
19195 		log.u_bbr.flex5 = log.u_bbr.inflight;
19196 		log.u_bbr.bbr_substate = (uint8_t)((len + segsiz - 1)/segsiz);
19197 		lgb = tcp_log_event(tp, th, NULL, NULL, TCP_LOG_OUT, ERRNO_UNK,
19198 				     len, &log, false, NULL, __func__, __LINE__, tv);
19199 	} else
19200 		lgb = NULL;
19201 #ifdef INET6
19202 	if (rack->r_is_v6) {
19203 		error = ip6_output(m, inp->in6p_outputopts,
19204 				   &inp->inp_route6,
19205 				   0, NULL, NULL, inp);
19206 	}
19207 #endif
19208 #if defined(INET) && defined(INET6)
19209 	else
19210 #endif
19211 #ifdef INET
19212 	{
19213 		error = ip_output(m, NULL,
19214 				  &inp->inp_route,
19215 				  0, 0, inp);
19216 	}
19217 #endif
19218 	if (lgb) {
19219 		lgb->tlb_errno = error;
19220 		lgb = NULL;
19221 	}
19222 	if (error) {
19223 		*send_err = error;
19224 		m = NULL;
19225 		goto failed;
19226 	} else if (rack->rc_hw_nobuf) {
19227 		rack->rc_hw_nobuf = 0;
19228 		rack->r_ctl.rc_agg_delayed = 0;
19229 		rack->r_early = 0;
19230 		rack->r_late = 0;
19231 		rack->r_ctl.rc_agg_early = 0;
19232 	}
19233 	if ((error == 0) && (rack->lt_bw_up == 0)) {
19234 		/* Unlikely */
19235 		rack->r_ctl.lt_timemark = tcp_tv_to_lusec(tv);
19236 		rack->r_ctl.lt_seq = tp->snd_una;
19237 		rack->lt_bw_up = 1;
19238 	} else if ((error == 0) &&
19239 		   (((tp->snd_max + len) - rack->r_ctl.lt_seq) > 0x7fffffff)) {
19240 		/*
19241 		 * Need to record what we have since we are
19242 		 * approaching seq wrap.
19243 		 */
19244 		struct timeval tv;
19245 		uint64_t tmark;
19246 
19247 		rack->r_ctl.lt_bw_bytes += (tp->snd_una - rack->r_ctl.lt_seq);
19248 		rack->r_ctl.lt_seq = tp->snd_una;
19249 		tmark = tcp_get_u64_usecs(&tv);
19250 		if (tmark > rack->r_ctl.lt_timemark) {
19251 			rack->r_ctl.lt_bw_time += (tmark - rack->r_ctl.lt_timemark);
19252 			rack->r_ctl.lt_timemark = tmark;
19253 		}
19254 	}
19255 	rack_log_output(tp, &to, len, tp->snd_max, flags, error, rack_to_usec_ts(tv),
19256 			NULL, add_flag, s_mb, s_soff, rack->r_ctl.fsb.hw_tls, segsiz);
19257 	if (tp->snd_una == tp->snd_max) {
19258 		rack->r_ctl.rc_tlp_rxt_last_time = cts;
19259 		rack_log_progress_event(rack, tp, ticks, PROGRESS_START, __LINE__);
19260 		tp->t_acktime = ticks;
19261 	}
19262 	counter_u64_add(rack_total_bytes, len);
19263 	tcp_account_for_send(tp, len, 0, 0, rack->r_ctl.fsb.hw_tls);
19264 
19265 	rack->forced_ack = 0;	/* If we send something zap the FA flag */
19266 	*tot_len += len;
19267 	if ((tp->t_flags & TF_GPUTINPROG) == 0)
19268 		rack_start_gp_measurement(tp, rack, tp->snd_max, sb_offset);
19269 	tp->snd_max += len;
19270 	tp->snd_nxt = tp->snd_max;
19271 	if (rack->rc_new_rnd_needed) {
19272 		rack_new_round_starts(tp, rack, tp->snd_max);
19273 	}
19274 	{
19275 		int idx;
19276 
19277 		idx = (len / segsiz) + 3;
19278 		if (idx >= TCP_MSS_ACCT_ATIMER)
19279 			counter_u64_add(rack_out_size[(TCP_MSS_ACCT_ATIMER-1)], 1);
19280 		else
19281 			counter_u64_add(rack_out_size[idx], 1);
19282 	}
19283 	if (len <= rack->r_ctl.fsb.left_to_send)
19284 		rack->r_ctl.fsb.left_to_send -= len;
19285 	else
19286 		rack->r_ctl.fsb.left_to_send = 0;
19287 	if (rack->r_ctl.fsb.left_to_send < segsiz) {
19288 		rack->r_fast_output = 0;
19289 		rack->r_ctl.fsb.left_to_send = 0;
19290 		/* At the end of fast_output scale up the sb */
19291 		SOCK_SENDBUF_LOCK(rack->rc_inp->inp_socket);
19292 		rack_sndbuf_autoscale(rack);
19293 		SOCK_SENDBUF_UNLOCK(rack->rc_inp->inp_socket);
19294 	}
19295 	if (tp->t_rtttime == 0) {
19296 		tp->t_rtttime = ticks;
19297 		tp->t_rtseq = startseq;
19298 		KMOD_TCPSTAT_INC(tcps_segstimed);
19299 	}
19300 	if ((rack->r_ctl.fsb.left_to_send >= segsiz) &&
19301 	    (max_val > len) &&
19302 	    (*tot_len < rack->r_ctl.rc_pace_max_segs) &&
19303 	    (tso == 0)) {
19304 		max_val -= len;
19305 		len = segsiz;
19306 		th = rack->r_ctl.fsb.th;
19307 #ifdef TCP_ACCOUNTING
19308 		cnt_thru++;
19309 #endif
19310 		goto again;
19311 	}
19312 	tp->t_flags &= ~(TF_ACKNOW | TF_DELACK);
19313 	counter_u64_add(rack_fto_send, 1);
19314 	pacing_delay = rack_get_pacing_delay(rack, tp, *tot_len, NULL, segsiz, __LINE__);
19315 	rack_start_hpts_timer(rack, tp, cts, pacing_delay, *tot_len, 0);
19316 #ifdef TCP_ACCOUNTING
19317 	crtsc = get_cyclecount();
19318 	if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
19319 		tp->tcp_cnt_counters[SND_OUT_DATA] += cnt_thru;
19320 		tp->tcp_proc_time[SND_OUT_DATA] += (crtsc - ts_val);
19321 		tp->tcp_cnt_counters[CNT_OF_MSS_OUT] += ((*tot_len + segsiz - 1) / segsiz);
19322 	}
19323 	sched_unpin();
19324 #endif
19325 	return (0);
19326 failed:
19327 	if (m)
19328 		m_free(m);
19329 	rack->r_fast_output = 0;
19330 	return (-1);
19331 }
19332 
19333 static inline void
19334 rack_setup_fast_output(struct tcpcb *tp, struct tcp_rack *rack,
19335 		       struct sockbuf *sb,
19336 		       int len, int orig_len, int segsiz, uint32_t pace_max_seg,
19337 		       bool hw_tls,
19338 		       uint16_t flags)
19339 {
19340 	rack->r_fast_output = 1;
19341 	rack->r_ctl.fsb.m = sbsndmbuf(sb, (tp->snd_max - tp->snd_una), &rack->r_ctl.fsb.off);
19342 	rack->r_ctl.fsb.o_m_len = rack->r_ctl.fsb.m->m_len;
19343 	rack->r_ctl.fsb.o_t_len = M_TRAILINGROOM(rack->r_ctl.fsb.m);
19344 	rack->r_ctl.fsb.tcp_flags = flags;
19345 	rack->r_ctl.fsb.left_to_send = orig_len - len;
19346 	if (rack->r_ctl.fsb.left_to_send < pace_max_seg) {
19347 		/* Less than a full sized pace, lets not  */
19348 		rack->r_fast_output = 0;
19349 		return;
19350 	} else {
19351 		/* Round down to the nearest pace_max_seg */
19352 		rack->r_ctl.fsb.left_to_send = rounddown(rack->r_ctl.fsb.left_to_send, pace_max_seg);
19353 	}
19354 	if (hw_tls)
19355 		rack->r_ctl.fsb.hw_tls = 1;
19356 	else
19357 		rack->r_ctl.fsb.hw_tls = 0;
19358 	KASSERT((rack->r_ctl.fsb.left_to_send <= (sbavail(sb) - (tp->snd_max - tp->snd_una))),
19359 		("rack:%p left_to_send:%u sbavail:%u out:%u",
19360 		 rack, rack->r_ctl.fsb.left_to_send, sbavail(sb),
19361 		 (tp->snd_max - tp->snd_una)));
19362 	if (rack->r_ctl.fsb.left_to_send < segsiz)
19363 		rack->r_fast_output = 0;
19364 	else {
19365 		if (rack->r_ctl.fsb.left_to_send == (sbavail(sb) - (tp->snd_max - tp->snd_una)))
19366 			rack->r_ctl.fsb.rfo_apply_push = 1;
19367 		else
19368 			rack->r_ctl.fsb.rfo_apply_push = 0;
19369 	}
19370 }
19371 
19372 static uint32_t
19373 rack_get_hpts_pacing_min_for_bw(struct tcp_rack *rack, int32_t segsiz)
19374 {
19375 	uint64_t min_time;
19376 	uint32_t maxlen;
19377 
19378 	min_time = (uint64_t)get_hpts_min_sleep_time();
19379 	maxlen = (uint32_t)((rack->r_ctl.gp_bw * min_time) / (uint64_t)HPTS_USEC_IN_SEC);
19380 	maxlen = roundup(maxlen, segsiz);
19381 	return (maxlen);
19382 }
19383 
19384 static struct rack_sendmap *
19385 rack_check_collapsed(struct tcp_rack *rack, uint32_t cts)
19386 {
19387 	struct rack_sendmap *rsm = NULL;
19388 	int thresh;
19389 
19390 restart:
19391 	rsm = tqhash_find(rack->r_ctl.tqh, rack->r_ctl.last_collapse_point);
19392 	if ((rsm == NULL) || ((rsm->r_flags & RACK_RWND_COLLAPSED) == 0)) {
19393 		/* Nothing, strange turn off validity  */
19394 		rack->r_collapse_point_valid = 0;
19395 		return (NULL);
19396 	}
19397 	/* Can we send it yet? */
19398 	if (rsm->r_end > (rack->rc_tp->snd_una + rack->rc_tp->snd_wnd)) {
19399 		/*
19400 		 * Receiver window has not grown enough for
19401 		 * the segment to be put on the wire.
19402 		 */
19403 		return (NULL);
19404 	}
19405 	if (rsm->r_flags & RACK_ACKED) {
19406 		/*
19407 		 * It has been sacked, lets move to the
19408 		 * next one if possible.
19409 		 */
19410 		rack->r_ctl.last_collapse_point = rsm->r_end;
19411 		/* Are we done? */
19412 		if (SEQ_GEQ(rack->r_ctl.last_collapse_point,
19413 			    rack->r_ctl.high_collapse_point)) {
19414 			rack->r_collapse_point_valid = 0;
19415 			return (NULL);
19416 		}
19417 		goto restart;
19418 	}
19419 	/* Now has it been long enough ? */
19420 	thresh = rack_calc_thresh_rack(rack, rack_grab_rtt(rack->rc_tp, rack), cts, __LINE__, 1);
19421 	if ((cts - ((uint32_t)rsm->r_tim_lastsent[(rsm->r_rtr_cnt-1)])) > thresh) {
19422 		rack_log_collapse(rack, rsm->r_start,
19423 				  (cts - ((uint32_t)rsm->r_tim_lastsent[(rsm->r_rtr_cnt-1)])),
19424 				  thresh, __LINE__, 6, rsm->r_flags, rsm);
19425 		return (rsm);
19426 	}
19427 	/* Not enough time */
19428 	rack_log_collapse(rack, rsm->r_start,
19429 			  (cts - ((uint32_t)rsm->r_tim_lastsent[(rsm->r_rtr_cnt-1)])),
19430 			  thresh, __LINE__, 7, rsm->r_flags, rsm);
19431 	return (NULL);
19432 }
19433 
19434 static inline void
19435 rack_validate_sizes(struct tcp_rack *rack, int32_t *len, int32_t segsiz, uint32_t pace_max_seg)
19436 {
19437 	if ((rack->full_size_rxt == 0) &&
19438 	    (rack->shape_rxt_to_pacing_min == 0) &&
19439 	    (*len >= segsiz)) {
19440 		*len = segsiz;
19441 	} else if (rack->shape_rxt_to_pacing_min &&
19442 		 rack->gp_ready) {
19443 		/* We use pacing min as shaping len req */
19444 		uint32_t maxlen;
19445 
19446 		maxlen = rack_get_hpts_pacing_min_for_bw(rack, segsiz);
19447 		if (*len > maxlen)
19448 			*len = maxlen;
19449 	} else {
19450 		/*
19451 		 * The else is full_size_rxt is on so send it all
19452 		 * note we do need to check this for exceeding
19453 		 * our max segment size due to the fact that
19454 		 * we do sometimes merge chunks together i.e.
19455 		 * we cannot just assume that we will never have
19456 		 * a chunk greater than pace_max_seg
19457 		 */
19458 		if (*len > pace_max_seg)
19459 			*len = pace_max_seg;
19460 	}
19461 }
19462 
19463 static int
19464 rack_output(struct tcpcb *tp)
19465 {
19466 	struct socket *so;
19467 	uint32_t recwin;
19468 	uint32_t sb_offset, s_moff = 0;
19469 	int32_t len, error = 0;
19470 	uint16_t flags;
19471 	struct mbuf *m, *s_mb = NULL;
19472 	struct mbuf *mb;
19473 	uint32_t if_hw_tsomaxsegcount = 0;
19474 	uint32_t if_hw_tsomaxsegsize;
19475 	int32_t segsiz, minseg;
19476 	long tot_len_this_send = 0;
19477 #ifdef INET
19478 	struct ip *ip = NULL;
19479 #endif
19480 	struct udphdr *udp = NULL;
19481 	struct tcp_rack *rack;
19482 	struct tcphdr *th;
19483 	uint8_t pass = 0;
19484 	uint8_t mark = 0;
19485 	uint8_t check_done = 0;
19486 	uint8_t wanted_cookie = 0;
19487 	u_char opt[TCP_MAXOLEN];
19488 	unsigned ipoptlen, optlen, hdrlen, ulen=0;
19489 	uint32_t rack_seq;
19490 
19491 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
19492 	unsigned ipsec_optlen = 0;
19493 
19494 #endif
19495 	int32_t idle, sendalot;
19496 	uint32_t tot_idle;
19497 	int32_t sub_from_prr = 0;
19498 	volatile int32_t sack_rxmit;
19499 	struct rack_sendmap *rsm = NULL;
19500 	int32_t tso, mtu;
19501 	struct tcpopt to;
19502 	int32_t pacing_delay = 0;
19503 	int32_t sup_rack = 0;
19504 	uint32_t cts, ms_cts, delayed, early;
19505 	uint32_t add_flag = RACK_SENT_SP;
19506 	/* The doing_tlp flag will be set by the actual rack_timeout_tlp() */
19507 	uint8_t doing_tlp = 0;
19508 	uint32_t cwnd_to_use, pace_max_seg;
19509 	int32_t do_a_prefetch = 0;
19510 	int32_t prefetch_rsm = 0;
19511 	int32_t orig_len = 0;
19512 	struct timeval tv;
19513 	int32_t prefetch_so_done = 0;
19514 	struct tcp_log_buffer *lgb;
19515 	struct inpcb *inp = tptoinpcb(tp);
19516 	struct sockbuf *sb;
19517 	uint64_t ts_val = 0;
19518 #ifdef TCP_ACCOUNTING
19519 	uint64_t crtsc;
19520 #endif
19521 #ifdef INET6
19522 	struct ip6_hdr *ip6 = NULL;
19523 	int32_t isipv6;
19524 #endif
19525 	bool hpts_calling, hw_tls = false;
19526 
19527 	NET_EPOCH_ASSERT();
19528 	INP_WLOCK_ASSERT(inp);
19529 
19530 	/* setup and take the cache hits here */
19531 	rack = (struct tcp_rack *)tp->t_fb_ptr;
19532 #ifdef TCP_ACCOUNTING
19533 	sched_pin();
19534 	ts_val = get_cyclecount();
19535 #endif
19536 	hpts_calling = !!(tp->t_flags2 & TF2_HPTS_CALLS);
19537 	tp->t_flags2 &= ~TF2_HPTS_CALLS;
19538 #ifdef TCP_OFFLOAD
19539 	if (tp->t_flags & TF_TOE) {
19540 #ifdef TCP_ACCOUNTING
19541 		sched_unpin();
19542 #endif
19543 		return (tcp_offload_output(tp));
19544 	}
19545 #endif
19546 	if (rack->rack_deferred_inited == 0) {
19547 		/*
19548 		 * If we are the connecting socket we will
19549 		 * hit rack_init() when no sequence numbers
19550 		 * are setup. This makes it so we must defer
19551 		 * some initialization. Call that now.
19552 		 */
19553 		rack_deferred_init(tp, rack);
19554 	}
19555 	/*
19556 	 * For TFO connections in SYN_RECEIVED, only allow the initial
19557 	 * SYN|ACK and those sent by the retransmit timer.
19558 	 */
19559 	if ((tp->t_flags & TF_FASTOPEN) &&
19560 	    (tp->t_state == TCPS_SYN_RECEIVED) &&
19561 	    SEQ_GT(tp->snd_max, tp->snd_una) &&    /* initial SYN|ACK sent */
19562 	    (rack->r_ctl.rc_resend == NULL)) {         /* not a retransmit */
19563 #ifdef TCP_ACCOUNTING
19564 		sched_unpin();
19565 #endif
19566 		return (0);
19567 	}
19568 #ifdef INET6
19569 	if (rack->r_state) {
19570 		/* Use the cache line loaded if possible */
19571 		isipv6 = rack->r_is_v6;
19572 	} else {
19573 		isipv6 = (rack->rc_inp->inp_vflag & INP_IPV6) != 0;
19574 	}
19575 #endif
19576 	early = 0;
19577 	cts = tcp_get_usecs(&tv);
19578 	ms_cts = tcp_tv_to_msec(&tv);
19579 	if (((rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT) == 0) &&
19580 	    tcp_in_hpts(rack->rc_tp)) {
19581 		/*
19582 		 * We are on the hpts for some timer but not hptsi output.
19583 		 * Remove from the hpts unconditionally.
19584 		 */
19585 		rack_timer_cancel(tp, rack, cts, __LINE__);
19586 	}
19587 	/* Are we pacing and late? */
19588 	if ((rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT) &&
19589 	    TSTMP_GEQ(cts, rack->r_ctl.rc_last_output_to)) {
19590 		/* We are delayed */
19591 		delayed = cts - rack->r_ctl.rc_last_output_to;
19592 	} else {
19593 		delayed = 0;
19594 	}
19595 	/* Do the timers, which may override the pacer */
19596 	if (rack->r_ctl.rc_hpts_flags & PACE_TMR_MASK) {
19597 		int retval;
19598 
19599 		retval = rack_process_timers(tp, rack, cts, hpts_calling,
19600 					     &doing_tlp);
19601 		if (retval != 0) {
19602 			counter_u64_add(rack_out_size[TCP_MSS_ACCT_ATIMER], 1);
19603 #ifdef TCP_ACCOUNTING
19604 			sched_unpin();
19605 #endif
19606 			/*
19607 			 * If timers want tcp_drop(), then pass error out,
19608 			 * otherwise suppress it.
19609 			 */
19610 			return (retval < 0 ? retval : 0);
19611 		}
19612 	}
19613 	if (rack->rc_in_persist) {
19614 		if (tcp_in_hpts(rack->rc_tp) == 0) {
19615 			/* Timer is not running */
19616 			rack_start_hpts_timer(rack, tp, cts, 0, 0, 0);
19617 		}
19618 #ifdef TCP_ACCOUNTING
19619 		sched_unpin();
19620 #endif
19621 		return (0);
19622 	}
19623 	if ((rack->rc_ack_required == 1) &&
19624 	    (rack->r_timer_override == 0)){
19625 		/* A timeout occurred and no ack has arrived */
19626 		if (tcp_in_hpts(rack->rc_tp) == 0) {
19627 			/* Timer is not running */
19628 			rack_start_hpts_timer(rack, tp, cts, 0, 0, 0);
19629 		}
19630 #ifdef TCP_ACCOUNTING
19631 		sched_unpin();
19632 #endif
19633 		return (0);
19634 	}
19635 	if ((rack->r_timer_override) ||
19636 	    (rack->rc_ack_can_sendout_data) ||
19637 	    (delayed) ||
19638 	    (tp->t_state < TCPS_ESTABLISHED)) {
19639 		rack->rc_ack_can_sendout_data = 0;
19640 		if (tcp_in_hpts(rack->rc_tp))
19641 			tcp_hpts_remove(rack->rc_tp);
19642 	} else if (tcp_in_hpts(rack->rc_tp)) {
19643 		/*
19644 		 * On the hpts you can't pass even if ACKNOW is on, we will
19645 		 * when the hpts fires.
19646 		 */
19647 #ifdef TCP_ACCOUNTING
19648 		crtsc = get_cyclecount();
19649 		if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
19650 			tp->tcp_proc_time[SND_BLOCKED] += (crtsc - ts_val);
19651 			tp->tcp_cnt_counters[SND_BLOCKED]++;
19652 		}
19653 		sched_unpin();
19654 #endif
19655 		counter_u64_add(rack_out_size[TCP_MSS_ACCT_INPACE], 1);
19656 		return (0);
19657 	}
19658 	/* Finish out both pacing early and late accounting */
19659 	if ((rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT) &&
19660 	    TSTMP_GT(rack->r_ctl.rc_last_output_to, cts)) {
19661 		early = rack->r_ctl.rc_last_output_to - cts;
19662 	} else
19663 		early = 0;
19664 	if (delayed && (rack->rc_always_pace == 1)) {
19665 		rack->r_ctl.rc_agg_delayed += delayed;
19666 		rack->r_late = 1;
19667 	} else if (early && (rack->rc_always_pace == 1)) {
19668 		rack->r_ctl.rc_agg_early += early;
19669 		rack->r_early = 1;
19670 	} else if (rack->rc_always_pace == 0) {
19671 		/* Non-paced we are not late */
19672 		rack->r_ctl.rc_agg_delayed = rack->r_ctl.rc_agg_early = 0;
19673 		rack->r_early = rack->r_late = 0;
19674 	}
19675 	/* Now that early/late accounting is done turn off the flag */
19676 	rack->r_ctl.rc_hpts_flags &= ~PACE_PKT_OUTPUT;
19677 	rack->r_wanted_output = 0;
19678 	rack->r_timer_override = 0;
19679 	if ((tp->t_state != rack->r_state) &&
19680 	    TCPS_HAVEESTABLISHED(tp->t_state)) {
19681 		rack_set_state(tp, rack);
19682 	}
19683 	segsiz = min(ctf_fixed_maxseg(tp), rack->r_ctl.rc_pace_min_segs);
19684 	minseg = segsiz;
19685 	if (rack->r_ctl.rc_pace_max_segs == 0)
19686 		pace_max_seg = rack->rc_user_set_max_segs * segsiz;
19687 	else
19688 		pace_max_seg = rack->r_ctl.rc_pace_max_segs;
19689 	if ((rack->r_fast_output) &&
19690 	    (doing_tlp == 0) &&
19691 	    (tp->rcv_numsacks == 0)) {
19692 		int ret;
19693 
19694 		error = 0;
19695 		ret = rack_fast_output(tp, rack, ts_val, cts, ms_cts, &tv, &tot_len_this_send, &error, __LINE__);
19696 		if (ret > 0)
19697 			return(ret);
19698 		else if (error) {
19699 			inp = rack->rc_inp;
19700 			so = inp->inp_socket;
19701 			sb = &so->so_snd;
19702 			goto nomore;
19703 		} else {
19704 			/* Return == 0, if there is more we can send tot_len wise fall through and send */
19705 			if (tot_len_this_send >= pace_max_seg)
19706 				return (ret);
19707 #ifdef TCP_ACCOUNTING
19708 			/* We need to re-pin since fast_output un-pined */
19709 			sched_pin();
19710 			ts_val = get_cyclecount();
19711 #endif
19712 			/* Fall back out so we can send any more that may bring us to pace_max_seg */
19713 		}
19714 	}
19715 	inp = rack->rc_inp;
19716 	/*
19717 	 * For TFO connections in SYN_SENT or SYN_RECEIVED,
19718 	 * only allow the initial SYN or SYN|ACK and those sent
19719 	 * by the retransmit timer.
19720 	 */
19721 	if ((tp->t_flags & TF_FASTOPEN) &&
19722 	    ((tp->t_state == TCPS_SYN_RECEIVED) ||
19723 	     (tp->t_state == TCPS_SYN_SENT)) &&
19724 	    SEQ_GT(tp->snd_max, tp->snd_una) && /* initial SYN or SYN|ACK sent */
19725 	    (tp->t_rxtshift == 0)) {              /* not a retransmit */
19726 		rack_start_hpts_timer(rack, tp, cts, 0, 0, 0);
19727 #ifdef TCP_ACCOUNTING
19728 		sched_unpin();
19729 #endif
19730 		return (0);
19731 	}
19732 	/*
19733 	 * Determine length of data that should be transmitted, and flags
19734 	 * that will be used. If there is some data or critical controls
19735 	 * (SYN, RST) to send, then transmit; otherwise, investigate
19736 	 * further.
19737 	 */
19738 	idle = (tp->t_flags & TF_LASTIDLE) || (tp->snd_max == tp->snd_una);
19739 	if (tp->t_idle_reduce) {
19740 		if (idle && (TICKS_2_USEC(ticks - tp->t_rcvtime) >= tp->t_rxtcur))
19741 			rack_cc_after_idle(rack, tp);
19742 	}
19743 	tp->t_flags &= ~TF_LASTIDLE;
19744 	if (idle) {
19745 		if (tp->t_flags & TF_MORETOCOME) {
19746 			tp->t_flags |= TF_LASTIDLE;
19747 			idle = 0;
19748 		}
19749 	}
19750 	if ((tp->snd_una == tp->snd_max) &&
19751 	    rack->r_ctl.rc_went_idle_time &&
19752 	    (cts > rack->r_ctl.rc_went_idle_time)) {
19753 		tot_idle = (cts - rack->r_ctl.rc_went_idle_time);
19754 		if (tot_idle > rack_min_probertt_hold) {
19755 			/* Count as a probe rtt */
19756 			if (rack->in_probe_rtt == 0) {
19757 				rack->r_ctl.rc_lower_rtt_us_cts = cts;
19758 				rack->r_ctl.rc_time_probertt_entered = rack->r_ctl.rc_lower_rtt_us_cts;
19759 				rack->r_ctl.rc_time_probertt_starts = rack->r_ctl.rc_lower_rtt_us_cts;
19760 				rack->r_ctl.rc_time_of_last_probertt = rack->r_ctl.rc_lower_rtt_us_cts;
19761 			} else {
19762 				rack_exit_probertt(rack, cts);
19763 			}
19764 		}
19765 	} else
19766 		tot_idle = 0;
19767 	if (rack_use_fsb &&
19768 	    (rack->r_ctl.fsb.tcp_ip_hdr) &&
19769 	    (rack->r_fsb_inited == 0) &&
19770 	    (rack->r_state != TCPS_CLOSED))
19771 		rack_init_fsb_block(tp, rack, tcp_outflags[tp->t_state]);
19772 	if (rack->rc_sendvars_notset == 1) {
19773 		rack->rc_sendvars_notset = 0;
19774 		/*
19775 		 * Make sure any TCP timers (keep-alive) is not running.
19776 		 */
19777 		tcp_timer_stop(tp);
19778 	}
19779 	if ((rack->rack_no_prr == 1) &&
19780 	    (rack->rc_always_pace == 0)) {
19781 		/*
19782 		 * Sanity check before sending, if we have
19783 		 * no-pacing enabled and prr is turned off that
19784 		 * is a logistics error. Correct this by turnning
19785 		 * prr back on. A user *must* set some form of
19786 		 * pacing in order to turn PRR off. We do this
19787 		 * in the output path so that we can avoid socket
19788 		 * option ordering issues that would occur if we
19789 		 * tried to do it while setting rack_no_prr on.
19790 		 */
19791 		rack->rack_no_prr = 0;
19792 	}
19793 	if ((rack->pcm_enabled == 1) &&
19794 	    (rack->pcm_needed == 0) &&
19795 	    (tot_idle > 0)) {
19796 		/*
19797 		 * We have been idle some micro seconds. We need
19798 		 * to factor this in to see if a PCM is needed.
19799 		 */
19800 		uint32_t rtts_idle, rnds;
19801 
19802 		if (tp->t_srtt)
19803 			rtts_idle = tot_idle / tp->t_srtt;
19804 		else
19805 			rtts_idle = 0;
19806 		rnds = rack->r_ctl.current_round - rack->r_ctl.last_pcm_round;
19807 		rack->r_ctl.pcm_idle_rounds += rtts_idle;
19808 		if ((rnds + rack->r_ctl.pcm_idle_rounds)  >= rack_pcm_every_n_rounds) {
19809 			rack->pcm_needed = 1;
19810 			rack_log_pcm(rack, 8, rack->r_ctl.last_pcm_round, rtts_idle, rack->r_ctl.current_round );
19811 		}
19812 	}
19813 again:
19814 	sendalot = 0;
19815 	cts = tcp_get_usecs(&tv);
19816 	ms_cts = tcp_tv_to_msec(&tv);
19817 	tso = 0;
19818 	mtu = 0;
19819 	if (TCPS_HAVEESTABLISHED(tp->t_state) &&
19820 	    (rack->r_ctl.pcm_max_seg == 0)) {
19821 		/*
19822 		 * We set in our first send so we know that the ctf_fixed_maxseg
19823 		 * has been fully set. If we do it in rack_init() we most likely
19824 		 * see 512 bytes so we end up at 5120, not desirable.
19825 		 */
19826 		rack->r_ctl.pcm_max_seg = rc_init_window(rack);
19827 		if (rack->r_ctl.pcm_max_seg < (ctf_fixed_maxseg(tp) * 10)) {
19828 			/*
19829 			 * Assure our initial PCM probe is at least 10 MSS.
19830 			 */
19831 			rack->r_ctl.pcm_max_seg = ctf_fixed_maxseg(tp) * 10;
19832 		}
19833 	}
19834 	if ((rack->r_ctl.pcm_max_seg != 0) && (rack->pcm_needed == 1)) {
19835 		uint32_t rw_avail, cwa;
19836 
19837 		if (tp->snd_wnd > ctf_outstanding(tp))
19838 			rw_avail = tp->snd_wnd - ctf_outstanding(tp);
19839 		else
19840 			rw_avail = 0;
19841 		if (tp->snd_cwnd > ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked))
19842 			cwa = tp->snd_cwnd -ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
19843 		else
19844 			cwa = 0;
19845 		if ((cwa >= rack->r_ctl.pcm_max_seg) &&
19846 		    (rw_avail > rack->r_ctl.pcm_max_seg)) {
19847 			/* Raise up the max seg for this trip through */
19848 			pace_max_seg = rack->r_ctl.pcm_max_seg;
19849 			/* Disable any fast output */
19850 			rack->r_fast_output = 0;
19851 		}
19852 		if (rack_verbose_logging) {
19853 			rack_log_pcm(rack, 4,
19854 				     cwa, rack->r_ctl.pcm_max_seg, rw_avail);
19855 		}
19856 	}
19857 	sb_offset = tp->snd_max - tp->snd_una;
19858 	cwnd_to_use = rack->r_ctl.cwnd_to_use = tp->snd_cwnd;
19859 	flags = tcp_outflags[tp->t_state];
19860 	while (rack->rc_free_cnt < rack_free_cache) {
19861 		rsm = rack_alloc(rack);
19862 		if (rsm == NULL) {
19863 			if (hpts_calling)
19864 				/* Retry in a ms */
19865 				pacing_delay = (1 * HPTS_USEC_IN_MSEC);
19866 			so = inp->inp_socket;
19867 			sb = &so->so_snd;
19868 			goto just_return_nolock;
19869 		}
19870 		TAILQ_INSERT_TAIL(&rack->r_ctl.rc_free, rsm, r_tnext);
19871 		rack->rc_free_cnt++;
19872 		rsm = NULL;
19873 	}
19874 	sack_rxmit = 0;
19875 	len = 0;
19876 	rsm = NULL;
19877 	if (flags & TH_RST) {
19878 		SOCK_SENDBUF_LOCK(inp->inp_socket);
19879 		so = inp->inp_socket;
19880 		sb = &so->so_snd;
19881 		goto send;
19882 	}
19883 	if (rack->r_ctl.rc_resend) {
19884 		/* Retransmit timer */
19885 		rsm = rack->r_ctl.rc_resend;
19886 		rack->r_ctl.rc_resend = NULL;
19887 		len = rsm->r_end - rsm->r_start;
19888 		sack_rxmit = 1;
19889 		sendalot = 0;
19890 		KASSERT(SEQ_LEQ(tp->snd_una, rsm->r_start),
19891 			("%s:%d: r.start:%u < SND.UNA:%u; tp:%p, rack:%p, rsm:%p",
19892 			 __func__, __LINE__,
19893 			 rsm->r_start, tp->snd_una, tp, rack, rsm));
19894 		sb_offset = rsm->r_start - tp->snd_una;
19895 		rack_validate_sizes(rack, &len, segsiz, pace_max_seg);
19896 	} else if (rack->r_collapse_point_valid &&
19897 		   ((rsm = rack_check_collapsed(rack, cts)) != NULL)) {
19898 		/*
19899 		 * If an RSM is returned then enough time has passed
19900 		 * for us to retransmit it. Move up the collapse point,
19901 		 * since this rsm has its chance to retransmit now.
19902 		 */
19903 		tcp_trace_point(rack->rc_tp, TCP_TP_COLLAPSED_RXT);
19904 		rack->r_ctl.last_collapse_point = rsm->r_end;
19905 		/* Are we done? */
19906 		if (SEQ_GEQ(rack->r_ctl.last_collapse_point,
19907 			    rack->r_ctl.high_collapse_point))
19908 			rack->r_collapse_point_valid = 0;
19909 		sack_rxmit = 1;
19910 		/* We are not doing a TLP */
19911 		doing_tlp = 0;
19912 		len = rsm->r_end - rsm->r_start;
19913 		sb_offset = rsm->r_start - tp->snd_una;
19914 		sendalot = 0;
19915 		rack_validate_sizes(rack, &len, segsiz, pace_max_seg);
19916 	} else if ((rsm = tcp_rack_output(tp, rack, cts)) != NULL) {
19917 		/* We have a retransmit that takes precedence */
19918 		if ((!IN_FASTRECOVERY(tp->t_flags)) &&
19919 		    ((rsm->r_flags & RACK_MUST_RXT) == 0) &&
19920 		    ((tp->t_flags & TF_WASFRECOVERY) == 0)) {
19921 			/* Enter recovery if not induced by a time-out */
19922 			rack_cong_signal(tp, CC_NDUPACK, tp->snd_una, __LINE__);
19923 		}
19924 #ifdef INVARIANTS
19925 		if (SEQ_LT(rsm->r_start, tp->snd_una)) {
19926 			panic("Huh, tp:%p rack:%p rsm:%p start:%u < snd_una:%u\n",
19927 			      tp, rack, rsm, rsm->r_start, tp->snd_una);
19928 		}
19929 #endif
19930 		len = rsm->r_end - rsm->r_start;
19931 		KASSERT(SEQ_LEQ(tp->snd_una, rsm->r_start),
19932 			("%s:%d: r.start:%u < SND.UNA:%u; tp:%p, rack:%p, rsm:%p",
19933 			 __func__, __LINE__,
19934 			 rsm->r_start, tp->snd_una, tp, rack, rsm));
19935 		sb_offset = rsm->r_start - tp->snd_una;
19936 		sendalot = 0;
19937 		rack_validate_sizes(rack, &len, segsiz, pace_max_seg);
19938 		if (len > 0) {
19939 			sack_rxmit = 1;
19940 			KMOD_TCPSTAT_INC(tcps_sack_rexmits);
19941 			KMOD_TCPSTAT_ADD(tcps_sack_rexmit_bytes,
19942 					 min(len, segsiz));
19943 		}
19944 	} else if (rack->r_ctl.rc_tlpsend) {
19945 		/* Tail loss probe */
19946 		long cwin;
19947 		long tlen;
19948 
19949 		/*
19950 		 * Check if we can do a TLP with a RACK'd packet
19951 		 * this can happen if we are not doing the rack
19952 		 * cheat and we skipped to a TLP and it
19953 		 * went off.
19954 		 */
19955 		rsm = rack->r_ctl.rc_tlpsend;
19956 		/* We are doing a TLP make sure the flag is preent */
19957 		rsm->r_flags |= RACK_TLP;
19958 		rack->r_ctl.rc_tlpsend = NULL;
19959 		sack_rxmit = 1;
19960 		tlen = rsm->r_end - rsm->r_start;
19961 		if (tlen > segsiz)
19962 			tlen = segsiz;
19963 		KASSERT(SEQ_LEQ(tp->snd_una, rsm->r_start),
19964 			("%s:%d: r.start:%u < SND.UNA:%u; tp:%p, rack:%p, rsm:%p",
19965 			 __func__, __LINE__,
19966 			 rsm->r_start, tp->snd_una, tp, rack, rsm));
19967 		sb_offset = rsm->r_start - tp->snd_una;
19968 		cwin = min(tp->snd_wnd, tlen);
19969 		len = cwin;
19970 	}
19971 	if (rack->r_must_retran &&
19972 	    (doing_tlp == 0) &&
19973 	    (SEQ_GT(tp->snd_max, tp->snd_una)) &&
19974 	    (rsm == NULL)) {
19975 		/*
19976 		 * There are two different ways that we
19977 		 * can get into this block:
19978 		 * a) This is a non-sack connection, we had a time-out
19979 		 *    and thus r_must_retran was set and everything
19980 		 *    left outstanding as been marked for retransmit.
19981 		 * b) The MTU of the path shrank, so that everything
19982 		 *    was marked to be retransmitted with the smaller
19983 		 *    mtu and r_must_retran was set.
19984 		 *
19985 		 * This means that we expect the sendmap (outstanding)
19986 		 * to all be marked must. We can use the tmap to
19987 		 * look at them.
19988 		 *
19989 		 */
19990 		int sendwin, flight;
19991 
19992 		sendwin = min(tp->snd_wnd, tp->snd_cwnd);
19993 		flight = ctf_flight_size(tp, rack->r_ctl.rc_out_at_rto);
19994 		if (flight >= sendwin) {
19995 			/*
19996 			 * We can't send yet.
19997 			 */
19998 			so = inp->inp_socket;
19999 			sb = &so->so_snd;
20000 			goto just_return_nolock;
20001 		}
20002 		/*
20003 		 * This is the case a/b mentioned above. All
20004 		 * outstanding/not-acked should be marked.
20005 		 * We can use the tmap to find them.
20006 		 */
20007 		rsm = TAILQ_FIRST(&rack->r_ctl.rc_tmap);
20008 		if (rsm == NULL) {
20009 			/* TSNH */
20010 			rack->r_must_retran = 0;
20011 			rack->r_ctl.rc_out_at_rto = 0;
20012 			so = inp->inp_socket;
20013 			sb = &so->so_snd;
20014 			goto just_return_nolock;
20015 		}
20016 		if ((rsm->r_flags & RACK_MUST_RXT) == 0) {
20017 			/*
20018 			 * The first one does not have the flag, did we collapse
20019 			 * further up in our list?
20020 			 */
20021 			rack->r_must_retran = 0;
20022 			rack->r_ctl.rc_out_at_rto = 0;
20023 			rsm = NULL;
20024 			sack_rxmit = 0;
20025 		} else {
20026 			sack_rxmit = 1;
20027 			len = rsm->r_end - rsm->r_start;
20028 			sb_offset = rsm->r_start - tp->snd_una;
20029 			sendalot = 0;
20030 			if ((rack->full_size_rxt == 0) &&
20031 			    (rack->shape_rxt_to_pacing_min == 0) &&
20032 			    (len >= segsiz))
20033 				len = segsiz;
20034 			else if (rack->shape_rxt_to_pacing_min &&
20035 				 rack->gp_ready) {
20036 				/* We use pacing min as shaping len req */
20037 				uint32_t maxlen;
20038 
20039 				maxlen = rack_get_hpts_pacing_min_for_bw(rack, segsiz);
20040 				if (len > maxlen)
20041 					len = maxlen;
20042 			}
20043 			/*
20044 			 * Delay removing the flag RACK_MUST_RXT so
20045 			 * that the fastpath for retransmit will
20046 			 * work with this rsm.
20047 			 */
20048 		}
20049 	}
20050 	/*
20051 	 * Enforce a connection sendmap count limit if set
20052 	 * as long as we are not retransmiting.
20053 	 */
20054 	if ((rsm == NULL) &&
20055 	    (V_tcp_map_entries_limit > 0) &&
20056 	    (rack->r_ctl.rc_num_maps_alloced >= V_tcp_map_entries_limit)) {
20057 		counter_u64_add(rack_to_alloc_limited, 1);
20058 		if (!rack->alloc_limit_reported) {
20059 			rack->alloc_limit_reported = 1;
20060 			counter_u64_add(rack_alloc_limited_conns, 1);
20061 		}
20062 		so = inp->inp_socket;
20063 		sb = &so->so_snd;
20064 		goto just_return_nolock;
20065 	}
20066 	if (rsm && (rsm->r_flags & RACK_HAS_FIN)) {
20067 		/* we are retransmitting the fin */
20068 		len--;
20069 		if (len) {
20070 			/*
20071 			 * When retransmitting data do *not* include the
20072 			 * FIN. This could happen from a TLP probe.
20073 			 */
20074 			flags &= ~TH_FIN;
20075 		}
20076 	}
20077 	if (rsm && rack->r_fsb_inited &&
20078 	    rack_use_rsm_rfo &&
20079 	    ((rsm->r_flags & RACK_HAS_FIN) == 0)) {
20080 		int ret;
20081 
20082 		ret = rack_fast_rsm_output(tp, rack, rsm, ts_val, cts, ms_cts, &tv, len, doing_tlp);
20083 		if (ret == 0)
20084 			return (0);
20085 	}
20086 	so = inp->inp_socket;
20087 	sb = &so->so_snd;
20088 	if (do_a_prefetch == 0) {
20089 		kern_prefetch(sb, &do_a_prefetch);
20090 		do_a_prefetch = 1;
20091 	}
20092 #ifdef NETFLIX_SHARED_CWND
20093 	if ((tp->t_flags2 & TF2_TCP_SCWND_ALLOWED) &&
20094 	    rack->rack_enable_scwnd) {
20095 		/* We are doing cwnd sharing */
20096 		if (rack->gp_ready &&
20097 		    (rack->rack_attempted_scwnd == 0) &&
20098 		    (rack->r_ctl.rc_scw == NULL) &&
20099 		    tp->t_lib) {
20100 			/* The pcbid is in, lets make an attempt */
20101 			counter_u64_add(rack_try_scwnd, 1);
20102 			rack->rack_attempted_scwnd = 1;
20103 			rack->r_ctl.rc_scw = tcp_shared_cwnd_alloc(tp,
20104 								   &rack->r_ctl.rc_scw_index,
20105 								   segsiz);
20106 		}
20107 		if (rack->r_ctl.rc_scw &&
20108 		    (rack->rack_scwnd_is_idle == 1) &&
20109 		    sbavail(&so->so_snd)) {
20110 			/* we are no longer out of data */
20111 			tcp_shared_cwnd_active(rack->r_ctl.rc_scw, rack->r_ctl.rc_scw_index);
20112 			rack->rack_scwnd_is_idle = 0;
20113 		}
20114 		if (rack->r_ctl.rc_scw) {
20115 			/* First lets update and get the cwnd */
20116 			rack->r_ctl.cwnd_to_use = cwnd_to_use = tcp_shared_cwnd_update(rack->r_ctl.rc_scw,
20117 										       rack->r_ctl.rc_scw_index,
20118 										       tp->snd_cwnd, tp->snd_wnd, segsiz);
20119 		}
20120 	}
20121 #endif
20122 	/*
20123 	 * Get standard flags, and add SYN or FIN if requested by 'hidden'
20124 	 * state flags.
20125 	 */
20126 	if (tp->t_flags & TF_NEEDFIN)
20127 		flags |= TH_FIN;
20128 	if (tp->t_flags & TF_NEEDSYN)
20129 		flags |= TH_SYN;
20130 	if ((sack_rxmit == 0) && (prefetch_rsm == 0)) {
20131 		void *end_rsm;
20132 		end_rsm = TAILQ_LAST_FAST(&rack->r_ctl.rc_tmap, rack_sendmap, r_tnext);
20133 		if (end_rsm)
20134 			kern_prefetch(end_rsm, &prefetch_rsm);
20135 		prefetch_rsm = 1;
20136 	}
20137 	SOCK_SENDBUF_LOCK(so);
20138 	if ((sack_rxmit == 0) &&
20139 	    (TCPS_HAVEESTABLISHED(tp->t_state) ||
20140 	    (tp->t_flags & TF_FASTOPEN))) {
20141 		/*
20142 		 * We are not retransmitting (sack_rxmit is 0) so we
20143 		 * are sending new data. This is always based on snd_max.
20144 		 * Now in theory snd_max may be equal to snd_una, if so
20145 		 * then nothing is outstanding and the offset would be 0.
20146 		 */
20147 		uint32_t avail;
20148 
20149 		avail = sbavail(sb);
20150 		if (SEQ_GT(tp->snd_max, tp->snd_una) && avail)
20151 			sb_offset = tp->snd_max - tp->snd_una;
20152 		else
20153 			sb_offset = 0;
20154 		if ((IN_FASTRECOVERY(tp->t_flags) == 0) || rack->rack_no_prr) {
20155 			if (rack->r_ctl.rc_tlp_new_data) {
20156 				/* TLP is forcing out new data */
20157 				if (rack->r_ctl.rc_tlp_new_data > (uint32_t) (avail - sb_offset)) {
20158 					rack->r_ctl.rc_tlp_new_data = (uint32_t) (avail - sb_offset);
20159 				}
20160 				if ((rack->r_ctl.rc_tlp_new_data + sb_offset) > tp->snd_wnd) {
20161 					if (tp->snd_wnd > sb_offset)
20162 						len = tp->snd_wnd - sb_offset;
20163 					else
20164 						len = 0;
20165 				} else {
20166 					len = rack->r_ctl.rc_tlp_new_data;
20167 				}
20168 				rack->r_ctl.rc_tlp_new_data = 0;
20169 			}  else {
20170 				len = rack_what_can_we_send(tp, rack, cwnd_to_use, avail, sb_offset);
20171 			}
20172 			if ((rack->r_ctl.crte == NULL) &&
20173 			    IN_FASTRECOVERY(tp->t_flags) &&
20174 			    (rack->full_size_rxt == 0) &&
20175 			    (rack->shape_rxt_to_pacing_min == 0) &&
20176 			    (len > segsiz)) {
20177 				/*
20178 				 * For prr=off, we need to send only 1 MSS
20179 				 * at a time. We do this because another sack could
20180 				 * be arriving that causes us to send retransmits and
20181 				 * we don't want to be on a long pace due to a larger send
20182 				 * that keeps us from sending out the retransmit.
20183 				 */
20184 				len = segsiz;
20185 			} else if (rack->shape_rxt_to_pacing_min &&
20186 				   rack->gp_ready) {
20187 				/* We use pacing min as shaping len req */
20188 				uint32_t maxlen;
20189 
20190 				maxlen = rack_get_hpts_pacing_min_for_bw(rack, segsiz);
20191 				if (len > maxlen)
20192 					len = maxlen;
20193 			}/* The else is full_size_rxt is on so send it all */
20194 		} else {
20195 			uint32_t outstanding;
20196 			/*
20197 			 * We are inside of a Fast recovery episode, this
20198 			 * is caused by a SACK or 3 dup acks. At this point
20199 			 * we have sent all the retransmissions and we rely
20200 			 * on PRR to dictate what we will send in the form of
20201 			 * new data.
20202 			 */
20203 
20204 			outstanding = tp->snd_max - tp->snd_una;
20205 			if ((rack->r_ctl.rc_prr_sndcnt + outstanding) > tp->snd_wnd) {
20206 				if (tp->snd_wnd > outstanding) {
20207 					len = tp->snd_wnd - outstanding;
20208 					/* Check to see if we have the data */
20209 					if ((sb_offset + len) > avail) {
20210 						/* It does not all fit */
20211 						if (avail > sb_offset)
20212 							len = avail - sb_offset;
20213 						else
20214 							len = 0;
20215 					}
20216 				} else {
20217 					len = 0;
20218 				}
20219 			} else if (avail > sb_offset) {
20220 				len = avail - sb_offset;
20221 			} else {
20222 				len = 0;
20223 			}
20224 			if (len > 0) {
20225 				if (len > rack->r_ctl.rc_prr_sndcnt) {
20226 					len = rack->r_ctl.rc_prr_sndcnt;
20227 				}
20228 				if (len > 0) {
20229 					sub_from_prr = 1;
20230 				}
20231 			}
20232 			if (len > segsiz) {
20233 				/*
20234 				 * We should never send more than a MSS when
20235 				 * retransmitting or sending new data in prr
20236 				 * mode unless the override flag is on. Most
20237 				 * likely the PRR algorithm is not going to
20238 				 * let us send a lot as well :-)
20239 				 */
20240 				if (rack->r_ctl.rc_prr_sendalot == 0) {
20241 					len = segsiz;
20242 				}
20243 			} else if (len < segsiz) {
20244 				/*
20245 				 * Do we send any? The idea here is if the
20246 				 * send empty's the socket buffer we want to
20247 				 * do it. However if not then lets just wait
20248 				 * for our prr_sndcnt to get bigger.
20249 				 */
20250 				long leftinsb;
20251 
20252 				leftinsb = sbavail(sb) - sb_offset;
20253 				if (leftinsb > len) {
20254 					/* This send does not empty the sb */
20255 					len = 0;
20256 				}
20257 			}
20258 		}
20259 	} else if (!TCPS_HAVEESTABLISHED(tp->t_state)) {
20260 		/*
20261 		 * If you have not established
20262 		 * and are not doing FAST OPEN
20263 		 * no data please.
20264 		 */
20265 		if ((sack_rxmit == 0) &&
20266 		    !(tp->t_flags & TF_FASTOPEN)) {
20267 			len = 0;
20268 			sb_offset = 0;
20269 		}
20270 	}
20271 	if (prefetch_so_done == 0) {
20272 		kern_prefetch(so, &prefetch_so_done);
20273 		prefetch_so_done = 1;
20274 	}
20275 	orig_len = len;
20276 	/*
20277 	 * Lop off SYN bit if it has already been sent.  However, if this is
20278 	 * SYN-SENT state and if segment contains data and if we don't know
20279 	 * that foreign host supports TAO, suppress sending segment.
20280 	 */
20281 	if ((flags & TH_SYN) &&
20282 	    SEQ_GT(tp->snd_max, tp->snd_una) &&
20283 	    ((sack_rxmit == 0) &&
20284 	     (tp->t_rxtshift == 0))) {
20285 		/*
20286 		 * When sending additional segments following a TFO SYN|ACK,
20287 		 * do not include the SYN bit.
20288 		 */
20289 		if ((tp->t_flags & TF_FASTOPEN) &&
20290 		    (tp->t_state == TCPS_SYN_RECEIVED))
20291 			flags &= ~TH_SYN;
20292 	}
20293 	/*
20294 	 * Be careful not to send data and/or FIN on SYN segments. This
20295 	 * measure is needed to prevent interoperability problems with not
20296 	 * fully conformant TCP implementations.
20297 	 */
20298 	if ((flags & TH_SYN) && (tp->t_flags & TF_NOOPT)) {
20299 		len = 0;
20300 		flags &= ~TH_FIN;
20301 	}
20302 	/*
20303 	 * On TFO sockets, ensure no data is sent in the following cases:
20304 	 *
20305 	 *  - When retransmitting SYN|ACK on a passively-created socket
20306 	 *
20307 	 *  - When retransmitting SYN on an actively created socket
20308 	 *
20309 	 *  - When sending a zero-length cookie (cookie request) on an
20310 	 *    actively created socket
20311 	 *
20312 	 *  - When the socket is in the CLOSED state (RST is being sent)
20313 	 */
20314 	if ((tp->t_flags & TF_FASTOPEN) &&
20315 	    (((flags & TH_SYN) && (tp->t_rxtshift > 0)) ||
20316 	     ((tp->t_state == TCPS_SYN_SENT) &&
20317 	      (tp->t_tfo_client_cookie_len == 0)) ||
20318 	     (flags & TH_RST))) {
20319 		sack_rxmit = 0;
20320 		len = 0;
20321 	}
20322 	/* Without fast-open there should never be data sent on a SYN */
20323 	if ((flags & TH_SYN) && !(tp->t_flags & TF_FASTOPEN)) {
20324 		len = 0;
20325 	}
20326 	if ((len > segsiz) && (tcp_dsack_block_exists(tp))) {
20327 		/* We only send 1 MSS if we have a DSACK block */
20328 		add_flag |= RACK_SENT_W_DSACK;
20329 		len = segsiz;
20330 	}
20331 	if (len <= 0) {
20332 		/*
20333 		 * We have nothing to send, or the window shrank, or
20334 		 * is closed, do we need to go into persists?
20335 		 */
20336 		len = 0;
20337 		if ((tp->snd_wnd == 0) &&
20338 		    (TCPS_HAVEESTABLISHED(tp->t_state)) &&
20339 		    (tp->snd_una == tp->snd_max) &&
20340 		    (sb_offset < (int)sbavail(sb))) {
20341 			rack_enter_persist(tp, rack, cts, tp->snd_una);
20342 		}
20343 	} else if ((rsm == NULL) &&
20344 		   (doing_tlp == 0) &&
20345 		   (len < pace_max_seg)) {
20346 		/*
20347 		 * We are not sending a maximum sized segment for
20348 		 * some reason. Should we not send anything (think
20349 		 * sws or persists)?
20350 		 */
20351 		if ((tp->snd_wnd < min((rack->r_ctl.rc_high_rwnd/2), minseg)) &&
20352 		    (TCPS_HAVEESTABLISHED(tp->t_state)) &&
20353 		    (len < minseg) &&
20354 		    (len < (int)(sbavail(sb) - sb_offset))) {
20355 			/*
20356 			 * Here the rwnd is less than
20357 			 * the minimum pacing size, this is not a retransmit,
20358 			 * we are established and
20359 			 * the send is not the last in the socket buffer
20360 			 * we send nothing, and we may enter persists
20361 			 * if nothing is outstanding.
20362 			 */
20363 			len = 0;
20364 			if (tp->snd_max == tp->snd_una) {
20365 				/*
20366 				 * Nothing out we can
20367 				 * go into persists.
20368 				 */
20369 				rack_enter_persist(tp, rack, cts, tp->snd_una);
20370 			}
20371 		} else if ((cwnd_to_use >= max(minseg, (segsiz * 4))) &&
20372 			   (ctf_flight_size(tp, rack->r_ctl.rc_sacked) > (2 * segsiz)) &&
20373 			   (len < (int)(sbavail(sb) - sb_offset)) &&
20374 			   (len < minseg)) {
20375 			/*
20376 			 * Here we are not retransmitting, and
20377 			 * the cwnd is not so small that we could
20378 			 * not send at least a min size (rxt timer
20379 			 * not having gone off), We have 2 segments or
20380 			 * more already in flight, its not the tail end
20381 			 * of the socket buffer  and the cwnd is blocking
20382 			 * us from sending out a minimum pacing segment size.
20383 			 * Lets not send anything.
20384 			 */
20385 			len = 0;
20386 		} else if (((tp->snd_wnd - ctf_outstanding(tp)) <
20387 			    min((rack->r_ctl.rc_high_rwnd/2), minseg)) &&
20388 			   (ctf_flight_size(tp, rack->r_ctl.rc_sacked) > (2 * segsiz)) &&
20389 			   (len < (int)(sbavail(sb) - sb_offset)) &&
20390 			   (TCPS_HAVEESTABLISHED(tp->t_state))) {
20391 			/*
20392 			 * Here we have a send window but we have
20393 			 * filled it up and we can't send another pacing segment.
20394 			 * We also have in flight more than 2 segments
20395 			 * and we are not completing the sb i.e. we allow
20396 			 * the last bytes of the sb to go out even if
20397 			 * its not a full pacing segment.
20398 			 */
20399 			len = 0;
20400 		} else if ((rack->r_ctl.crte != NULL) &&
20401 			   (tp->snd_wnd >= (pace_max_seg * max(1, rack_hw_rwnd_factor))) &&
20402 			   (cwnd_to_use >= (pace_max_seg + (4 * segsiz))) &&
20403 			   (ctf_flight_size(tp, rack->r_ctl.rc_sacked) >= (2 * segsiz)) &&
20404 			   (len < (int)(sbavail(sb) - sb_offset))) {
20405 			/*
20406 			 * Here we are doing hardware pacing, this is not a TLP,
20407 			 * we are not sending a pace max segment size, there is rwnd
20408 			 * room to send at least N pace_max_seg, the cwnd is greater
20409 			 * than or equal to a full pacing segments plus 4 mss and we have 2 or
20410 			 * more segments in flight and its not the tail of the socket buffer.
20411 			 *
20412 			 * We don't want to send instead we need to get more ack's in to
20413 			 * allow us to send a full pacing segment. Normally, if we are pacing
20414 			 * about the right speed, we should have finished our pacing
20415 			 * send as most of the acks have come back if we are at the
20416 			 * right rate. This is a bit fuzzy since return path delay
20417 			 * can delay the acks, which is why we want to make sure we
20418 			 * have cwnd space to have a bit more than a max pace segments in flight.
20419 			 *
20420 			 * If we have not gotten our acks back we are pacing at too high a
20421 			 * rate delaying will not hurt and will bring our GP estimate down by
20422 			 * injecting the delay. If we don't do this we will send
20423 			 * 2 MSS out in response to the acks being clocked in which
20424 			 * defeats the point of hw-pacing (i.e. to help us get
20425 			 * larger TSO's out).
20426 			 */
20427 			len = 0;
20428 		}
20429 
20430 	}
20431 	/* len will be >= 0 after this point. */
20432 	KASSERT(len >= 0, ("[%s:%d]: len < 0", __func__, __LINE__));
20433 	rack_sndbuf_autoscale(rack);
20434 	/*
20435 	 * Decide if we can use TCP Segmentation Offloading (if supported by
20436 	 * hardware).
20437 	 *
20438 	 * TSO may only be used if we are in a pure bulk sending state.  The
20439 	 * presence of TCP-MD5, SACK retransmits, SACK advertizements and IP
20440 	 * options prevent using TSO.  With TSO the TCP header is the same
20441 	 * (except for the sequence number) for all generated packets.  This
20442 	 * makes it impossible to transmit any options which vary per
20443 	 * generated segment or packet.
20444 	 *
20445 	 * IPv4 handling has a clear separation of ip options and ip header
20446 	 * flags while IPv6 combines both in in6p_outputopts. ip6_optlen() does
20447 	 * the right thing below to provide length of just ip options and thus
20448 	 * checking for ipoptlen is enough to decide if ip options are present.
20449 	 */
20450 	ipoptlen = 0;
20451 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
20452 	/*
20453 	 * Pre-calculate here as we save another lookup into the darknesses
20454 	 * of IPsec that way and can actually decide if TSO is ok.
20455 	 */
20456 #ifdef INET6
20457 	if (isipv6 && IPSEC_ENABLED(ipv6))
20458 		ipsec_optlen = IPSEC_HDRSIZE(ipv6, inp);
20459 #ifdef INET
20460 	else
20461 #endif
20462 #endif				/* INET6 */
20463 #ifdef INET
20464 		if (IPSEC_ENABLED(ipv4))
20465 			ipsec_optlen = IPSEC_HDRSIZE(ipv4, inp);
20466 #endif				/* INET */
20467 #endif
20468 
20469 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
20470 	ipoptlen += ipsec_optlen;
20471 #endif
20472 	if ((tp->t_flags & TF_TSO) && V_tcp_do_tso && len > segsiz &&
20473 	    (tp->t_port == 0) &&
20474 	    ((tp->t_flags & TF_SIGNATURE) == 0) &&
20475 	    sack_rxmit == 0 &&
20476 	    ipoptlen == 0)
20477 		tso = 1;
20478 	{
20479 		uint32_t outstanding __unused;
20480 
20481 		outstanding = tp->snd_max - tp->snd_una;
20482 		if (tp->t_flags & TF_SENTFIN) {
20483 			/*
20484 			 * If we sent a fin, snd_max is 1 higher than
20485 			 * snd_una
20486 			 */
20487 			outstanding--;
20488 		}
20489 		if (sack_rxmit) {
20490 			if ((rsm->r_flags & RACK_HAS_FIN) == 0)
20491 				flags &= ~TH_FIN;
20492 		}
20493 	}
20494 	recwin = lmin(lmax(sbspace(&so->so_rcv), 0),
20495 		      (long)TCP_MAXWIN << tp->rcv_scale);
20496 
20497 	/*
20498 	 * Sender silly window avoidance.   We transmit under the following
20499 	 * conditions when len is non-zero:
20500 	 *
20501 	 * - We have a full segment (or more with TSO) - This is the last
20502 	 * buffer in a write()/send() and we are either idle or running
20503 	 * NODELAY - we've timed out (e.g. persist timer) - we have more
20504 	 * then 1/2 the maximum send window's worth of data (receiver may be
20505 	 * limited the window size) - we need to retransmit
20506 	 */
20507 	if (len) {
20508 		if (len >= segsiz) {
20509 			goto send;
20510 		}
20511 		/*
20512 		 * NOTE! on localhost connections an 'ack' from the remote
20513 		 * end may occur synchronously with the output and cause us
20514 		 * to flush a buffer queued with moretocome.  XXX
20515 		 *
20516 		 */
20517 		if (!(tp->t_flags & TF_MORETOCOME) &&	/* normal case */
20518 		    (idle || (tp->t_flags & TF_NODELAY)) &&
20519 		    ((uint32_t)len + (uint32_t)sb_offset >= sbavail(sb)) &&
20520 		    (tp->t_flags & TF_NOPUSH) == 0) {
20521 			pass = 2;
20522 			goto send;
20523 		}
20524 		if ((tp->snd_una == tp->snd_max) && len) {	/* Nothing outstanding */
20525 			pass = 22;
20526 			goto send;
20527 		}
20528 		if (len >= tp->max_sndwnd / 2 && tp->max_sndwnd > 0) {
20529 			pass = 4;
20530 			goto send;
20531 		}
20532 		if (sack_rxmit) {
20533 			pass = 6;
20534 			goto send;
20535 		}
20536 		if (((tp->snd_wnd - ctf_outstanding(tp)) < segsiz) &&
20537 		    (ctf_outstanding(tp) < (segsiz * 2))) {
20538 			/*
20539 			 * We have less than two MSS outstanding (delayed ack)
20540 			 * and our rwnd will not let us send a full sized
20541 			 * MSS. Lets go ahead and let this small segment
20542 			 * out because we want to try to have at least two
20543 			 * packets inflight to not be caught by delayed ack.
20544 			 */
20545 			pass = 12;
20546 			goto send;
20547 		}
20548 	}
20549 	/*
20550 	 * Sending of standalone window updates.
20551 	 *
20552 	 * Window updates are important when we close our window due to a
20553 	 * full socket buffer and are opening it again after the application
20554 	 * reads data from it.  Once the window has opened again and the
20555 	 * remote end starts to send again the ACK clock takes over and
20556 	 * provides the most current window information.
20557 	 *
20558 	 * We must avoid the silly window syndrome whereas every read from
20559 	 * the receive buffer, no matter how small, causes a window update
20560 	 * to be sent.  We also should avoid sending a flurry of window
20561 	 * updates when the socket buffer had queued a lot of data and the
20562 	 * application is doing small reads.
20563 	 *
20564 	 * Prevent a flurry of pointless window updates by only sending an
20565 	 * update when we can increase the advertized window by more than
20566 	 * 1/4th of the socket buffer capacity.  When the buffer is getting
20567 	 * full or is very small be more aggressive and send an update
20568 	 * whenever we can increase by two mss sized segments. In all other
20569 	 * situations the ACK's to new incoming data will carry further
20570 	 * window increases.
20571 	 *
20572 	 * Don't send an independent window update if a delayed ACK is
20573 	 * pending (it will get piggy-backed on it) or the remote side
20574 	 * already has done a half-close and won't send more data.  Skip
20575 	 * this if the connection is in T/TCP half-open state.
20576 	 */
20577 	if (recwin > 0 && !(tp->t_flags & TF_NEEDSYN) &&
20578 	    !(tp->t_flags & TF_DELACK) &&
20579 	    !TCPS_HAVERCVDFIN(tp->t_state)) {
20580 		/*
20581 		 * "adv" is the amount we could increase the window, taking
20582 		 * into account that we are limited by TCP_MAXWIN <<
20583 		 * tp->rcv_scale.
20584 		 */
20585 		int32_t adv;
20586 		int oldwin;
20587 
20588 		adv = recwin;
20589 		if (SEQ_GT(tp->rcv_adv, tp->rcv_nxt)) {
20590 			oldwin = (tp->rcv_adv - tp->rcv_nxt);
20591 			if (adv > oldwin)
20592 				adv -= oldwin;
20593 			else {
20594 				/* We can't increase the window */
20595 				adv = 0;
20596 			}
20597 		} else
20598 			oldwin = 0;
20599 
20600 		/*
20601 		 * If the new window size ends up being the same as or less
20602 		 * than the old size when it is scaled, then don't force
20603 		 * a window update.
20604 		 */
20605 		if (oldwin >> tp->rcv_scale >= (adv + oldwin) >> tp->rcv_scale)
20606 			goto dontupdate;
20607 
20608 		if (adv >= (int32_t)(2 * segsiz) &&
20609 		    (adv >= (int32_t)(so->so_rcv.sb_hiwat / 4) ||
20610 		     recwin <= (int32_t)(so->so_rcv.sb_hiwat / 8) ||
20611 		     so->so_rcv.sb_hiwat <= 8 * segsiz)) {
20612 			pass = 7;
20613 			goto send;
20614 		}
20615 		if (2 * adv >= (int32_t) so->so_rcv.sb_hiwat) {
20616 			pass = 23;
20617 			goto send;
20618 		}
20619 	}
20620 dontupdate:
20621 
20622 	/*
20623 	 * Send if we owe the peer an ACK, RST, SYN, or urgent data.  ACKNOW
20624 	 * is also a catch-all for the retransmit timer timeout case.
20625 	 */
20626 	if (tp->t_flags & TF_ACKNOW) {
20627 		pass = 8;
20628 		goto send;
20629 	}
20630 	if (((flags & TH_SYN) && (tp->t_flags & TF_NEEDSYN) == 0)) {
20631 		pass = 9;
20632 		goto send;
20633 	}
20634 	/*
20635 	 * If our state indicates that FIN should be sent and we have not
20636 	 * yet done so, then we need to send.
20637 	 */
20638 	if ((flags & TH_FIN) &&
20639 	    (tp->snd_max == tp->snd_una)) {
20640 		pass = 11;
20641 		goto send;
20642 	}
20643 	/*
20644 	 * No reason to send a segment, just return.
20645 	 */
20646 just_return:
20647 	SOCK_SENDBUF_UNLOCK(so);
20648 just_return_nolock:
20649 	{
20650 		int app_limited = CTF_JR_SENT_DATA;
20651 
20652 		if ((tp->t_flags & TF_FASTOPEN) == 0 &&
20653 		    (flags & TH_FIN) &&
20654 		    (len == 0) &&
20655 		    (sbused(sb) == (tp->snd_max - tp->snd_una)) &&
20656 		    ((tp->snd_max - tp->snd_una) <= segsiz)) {
20657 			/*
20658 			 * Ok less than or right at a MSS is
20659 			 * outstanding. The original FreeBSD stack would
20660 			 * have sent a FIN, which can speed things up for
20661 			 * a transactional application doing a MSG_WAITALL.
20662 			 * To speed things up since we do *not* send a FIN
20663 			 * if data is outstanding, we send a "challenge ack".
20664 			 * The idea behind that is instead of having to have
20665 			 * the peer wait for the delayed-ack timer to run off
20666 			 * we send an ack that makes the peer send us an ack.
20667 			 */
20668 			rack_send_ack_challange(rack);
20669 		}
20670 		if (tot_len_this_send > 0) {
20671 			rack->r_ctl.fsb.recwin = recwin;
20672 			pacing_delay = rack_get_pacing_delay(rack, tp, tot_len_this_send, NULL, segsiz, __LINE__);
20673 			if ((error == 0) &&
20674 			    rack_use_rfo &&
20675 			    ((flags & (TH_SYN|TH_FIN)) == 0) &&
20676 			    (ipoptlen == 0) &&
20677 			    rack->r_fsb_inited &&
20678 			    TCPS_HAVEESTABLISHED(tp->t_state) &&
20679 			    ((IN_RECOVERY(tp->t_flags)) == 0) &&
20680 			    (doing_tlp == 0) &&
20681 			    (rack->r_must_retran == 0) &&
20682 			    ((tp->t_flags & TF_NEEDFIN) == 0) &&
20683 			    (len > 0) && (orig_len > 0) &&
20684 			    (orig_len > len) &&
20685 			    ((orig_len - len) >= segsiz) &&
20686 			    ((optlen == 0) ||
20687 			     ((optlen == TCPOLEN_TSTAMP_APPA) && (to.to_flags & TOF_TS)))) {
20688 				/* We can send at least one more MSS using our fsb */
20689 				rack_setup_fast_output(tp, rack, sb, len, orig_len,
20690 						       segsiz, pace_max_seg, hw_tls, flags);
20691 			} else
20692 				rack->r_fast_output = 0;
20693 			rack_log_fsb(rack, tp, so, flags,
20694 				     ipoptlen, orig_len, len, 0,
20695 				     1, optlen, __LINE__, 1);
20696 			/* Assure when we leave that snd_nxt will point to top */
20697 			if (SEQ_GT(tp->snd_max, tp->snd_nxt))
20698 				tp->snd_nxt = tp->snd_max;
20699 		} else {
20700 			int end_window = 0;
20701 			uint32_t seq = tp->gput_ack;
20702 
20703 			rsm = tqhash_max(rack->r_ctl.tqh);
20704 			if (rsm) {
20705 				/*
20706 				 * Mark the last sent that we just-returned (hinting
20707 				 * that delayed ack may play a role in any rtt measurement).
20708 				 */
20709 				rsm->r_just_ret = 1;
20710 			}
20711 			counter_u64_add(rack_out_size[TCP_MSS_ACCT_JUSTRET], 1);
20712 			rack->r_ctl.rc_agg_delayed = 0;
20713 			rack->r_early = 0;
20714 			rack->r_late = 0;
20715 			rack->r_ctl.rc_agg_early = 0;
20716 			if ((ctf_outstanding(tp) +
20717 			     min(max(segsiz, (rack->r_ctl.rc_high_rwnd/2)),
20718 				 minseg)) >= tp->snd_wnd) {
20719 				/* We are limited by the rwnd */
20720 				app_limited = CTF_JR_RWND_LIMITED;
20721 				if (IN_FASTRECOVERY(tp->t_flags))
20722 					rack->r_ctl.rc_prr_sndcnt = 0;
20723 			} else if (ctf_outstanding(tp) >= sbavail(sb)) {
20724 				/* We are limited by whats available -- app limited */
20725 				app_limited = CTF_JR_APP_LIMITED;
20726 				if (IN_FASTRECOVERY(tp->t_flags))
20727 					rack->r_ctl.rc_prr_sndcnt = 0;
20728 			} else if ((idle == 0) &&
20729 				   ((tp->t_flags & TF_NODELAY) == 0) &&
20730 				   ((uint32_t)len + (uint32_t)sb_offset >= sbavail(sb)) &&
20731 				   (len < segsiz)) {
20732 				/*
20733 				 * No delay is not on and the
20734 				 * user is sending less than 1MSS. This
20735 				 * brings out SWS avoidance so we
20736 				 * don't send. Another app-limited case.
20737 				 */
20738 				app_limited = CTF_JR_APP_LIMITED;
20739 			} else if (tp->t_flags & TF_NOPUSH) {
20740 				/*
20741 				 * The user has requested no push of
20742 				 * the last segment and we are
20743 				 * at the last segment. Another app
20744 				 * limited case.
20745 				 */
20746 				app_limited = CTF_JR_APP_LIMITED;
20747 			} else if ((ctf_outstanding(tp) + minseg) > cwnd_to_use) {
20748 				/* Its the cwnd */
20749 				app_limited = CTF_JR_CWND_LIMITED;
20750 			} else if (IN_FASTRECOVERY(tp->t_flags) &&
20751 				   (rack->rack_no_prr == 0) &&
20752 				   (rack->r_ctl.rc_prr_sndcnt < segsiz)) {
20753 				app_limited = CTF_JR_PRR;
20754 			} else {
20755 				/* Now why here are we not sending? */
20756 #ifdef NOW
20757 #ifdef INVARIANTS
20758 				panic("rack:%p hit JR_ASSESSING case cwnd_to_use:%u?", rack, cwnd_to_use);
20759 #endif
20760 #endif
20761 				app_limited = CTF_JR_ASSESSING;
20762 			}
20763 			/*
20764 			 * App limited in some fashion, for our pacing GP
20765 			 * measurements we don't want any gap (even cwnd).
20766 			 * Close  down the measurement window.
20767 			 */
20768 			if (rack_cwnd_block_ends_measure &&
20769 			    ((app_limited == CTF_JR_CWND_LIMITED) ||
20770 			     (app_limited == CTF_JR_PRR))) {
20771 				/*
20772 				 * The reason we are not sending is
20773 				 * the cwnd (or prr). We have been configured
20774 				 * to end the measurement window in
20775 				 * this case.
20776 				 */
20777 				end_window = 1;
20778 			} else if (rack_rwnd_block_ends_measure &&
20779 				   (app_limited == CTF_JR_RWND_LIMITED)) {
20780 				/*
20781 				 * We are rwnd limited and have been
20782 				 * configured to end the measurement
20783 				 * window in this case.
20784 				 */
20785 				end_window = 1;
20786 			} else if (app_limited == CTF_JR_APP_LIMITED) {
20787 				/*
20788 				 * A true application limited period, we have
20789 				 * ran out of data.
20790 				 */
20791 				end_window = 1;
20792 			} else if (app_limited == CTF_JR_ASSESSING) {
20793 				/*
20794 				 * In the assessing case we hit the end of
20795 				 * the if/else and had no known reason
20796 				 * This will panic us under invariants..
20797 				 *
20798 				 * If we get this out in logs we need to
20799 				 * investagate which reason we missed.
20800 				 */
20801 				end_window = 1;
20802 			}
20803 			if (end_window) {
20804 				uint8_t log = 0;
20805 
20806 				/* Adjust the Gput measurement */
20807 				if ((tp->t_flags & TF_GPUTINPROG) &&
20808 				    SEQ_GT(tp->gput_ack, tp->snd_max)) {
20809 					tp->gput_ack = tp->snd_max;
20810 					if ((tp->gput_ack - tp->gput_seq) < (MIN_GP_WIN * segsiz)) {
20811 						/*
20812 						 * There is not enough to measure.
20813 						 */
20814 						tp->t_flags &= ~TF_GPUTINPROG;
20815 						rack_log_pacing_delay_calc(rack, (tp->gput_ack - tp->gput_seq) /*flex2*/,
20816 									   rack->r_ctl.rc_gp_srtt /*flex1*/,
20817 									   tp->gput_seq,
20818 									   0, 0, 18, __LINE__, NULL, 0);
20819 					} else
20820 						log = 1;
20821 				}
20822 				/* Mark the last packet as app limited */
20823 				rsm = tqhash_max(rack->r_ctl.tqh);
20824 				if (rsm && ((rsm->r_flags & RACK_APP_LIMITED) == 0)) {
20825 					if (rack->r_ctl.rc_app_limited_cnt == 0)
20826 						rack->r_ctl.rc_end_appl = rack->r_ctl.rc_first_appl = rsm;
20827 					else {
20828 						/*
20829 						 * Go out to the end app limited and mark
20830 						 * this new one as next and move the end_appl up
20831 						 * to this guy.
20832 						 */
20833 						if (rack->r_ctl.rc_end_appl)
20834 							rack->r_ctl.rc_end_appl->r_nseq_appl = rsm->r_start;
20835 						rack->r_ctl.rc_end_appl = rsm;
20836 					}
20837 					rsm->r_flags |= RACK_APP_LIMITED;
20838 					rack->r_ctl.rc_app_limited_cnt++;
20839 				}
20840 				if (log)
20841 					rack_log_pacing_delay_calc(rack,
20842 								   rack->r_ctl.rc_app_limited_cnt, seq,
20843 								   tp->gput_ack, 0, 0, 4, __LINE__, NULL, 0);
20844 			}
20845 		}
20846 		/* Check if we need to go into persists or not */
20847 		if ((tp->snd_max == tp->snd_una) &&
20848 		    TCPS_HAVEESTABLISHED(tp->t_state) &&
20849 		    sbavail(sb) &&
20850 		    (sbavail(sb) > tp->snd_wnd) &&
20851 		    (tp->snd_wnd < min((rack->r_ctl.rc_high_rwnd/2), minseg))) {
20852 			/* Yes lets make sure to move to persist before timer-start */
20853 			rack_enter_persist(tp, rack, rack->r_ctl.rc_rcvtime, tp->snd_una);
20854 		}
20855 		rack_start_hpts_timer(rack, tp, cts, pacing_delay, tot_len_this_send, sup_rack);
20856 		rack_log_type_just_return(rack, cts, tot_len_this_send, pacing_delay, hpts_calling, app_limited, cwnd_to_use);
20857 	}
20858 #ifdef NETFLIX_SHARED_CWND
20859 	if ((sbavail(sb) == 0) &&
20860 	    rack->r_ctl.rc_scw) {
20861 		tcp_shared_cwnd_idle(rack->r_ctl.rc_scw, rack->r_ctl.rc_scw_index);
20862 		rack->rack_scwnd_is_idle = 1;
20863 	}
20864 #endif
20865 #ifdef TCP_ACCOUNTING
20866 	if (tot_len_this_send > 0) {
20867 		crtsc = get_cyclecount();
20868 		if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
20869 			tp->tcp_cnt_counters[SND_OUT_DATA]++;
20870 			tp->tcp_proc_time[SND_OUT_DATA] += (crtsc - ts_val);
20871 			tp->tcp_cnt_counters[CNT_OF_MSS_OUT] += ((tot_len_this_send + segsiz - 1) / segsiz);
20872 		}
20873 	} else {
20874 		crtsc = get_cyclecount();
20875 		if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
20876 			tp->tcp_cnt_counters[SND_LIMITED]++;
20877 			tp->tcp_proc_time[SND_LIMITED] += (crtsc - ts_val);
20878 		}
20879 	}
20880 	sched_unpin();
20881 #endif
20882 	return (0);
20883 
20884 send:
20885 	if ((rack->r_ctl.crte != NULL) &&
20886 	    (rsm == NULL) &&
20887 	    ((rack->rc_hw_nobuf == 1) ||
20888 	     (rack_hw_check_queue && (check_done == 0)))) {
20889 		/*
20890 		 * We only want to do this once with the hw_check_queue,
20891 		 * for the enobuf case we would only do it once if
20892 		 * we come around to again, the flag will be clear.
20893 		 */
20894 		check_done = 1;
20895 		pacing_delay = rack_check_queue_level(rack, tp, &tv, cts, len, segsiz);
20896 		if (pacing_delay) {
20897 			rack->r_ctl.rc_agg_delayed = 0;
20898 			rack->r_ctl.rc_agg_early = 0;
20899 			rack->r_early = 0;
20900 			rack->r_late = 0;
20901 			SOCK_SENDBUF_UNLOCK(so);
20902 			goto skip_all_send;
20903 		}
20904 	}
20905 	if (rsm || sack_rxmit)
20906 		counter_u64_add(rack_nfto_resend, 1);
20907 	else
20908 		counter_u64_add(rack_non_fto_send, 1);
20909 	if ((flags & TH_FIN) &&
20910 	    sbavail(sb)) {
20911 		/*
20912 		 * We do not transmit a FIN
20913 		 * with data outstanding. We
20914 		 * need to make it so all data
20915 		 * is acked first.
20916 		 */
20917 		flags &= ~TH_FIN;
20918 		if (TCPS_HAVEESTABLISHED(tp->t_state) &&
20919 		    (sbused(sb) == (tp->snd_max - tp->snd_una)) &&
20920 		    ((tp->snd_max - tp->snd_una) <= segsiz)) {
20921 			/*
20922 			 * Ok less than or right at a MSS is
20923 			 * outstanding. The original FreeBSD stack would
20924 			 * have sent a FIN, which can speed things up for
20925 			 * a transactional application doing a MSG_WAITALL.
20926 			 * To speed things up since we do *not* send a FIN
20927 			 * if data is outstanding, we send a "challenge ack".
20928 			 * The idea behind that is instead of having to have
20929 			 * the peer wait for the delayed-ack timer to run off
20930 			 * we send an ack that makes the peer send us an ack.
20931 			 */
20932 			rack_send_ack_challange(rack);
20933 		}
20934 	}
20935 	/* Enforce stack imposed max seg size if we have one */
20936 	if (pace_max_seg &&
20937 	    (len > pace_max_seg)) {
20938 		mark = 1;
20939 		len = pace_max_seg;
20940 	}
20941 	if ((rsm == NULL) &&
20942 	    (rack->pcm_in_progress == 0) &&
20943 	    (rack->r_ctl.pcm_max_seg > 0) &&
20944 	    (len >= rack->r_ctl.pcm_max_seg)) {
20945 		/* It is large enough for a measurement */
20946 		add_flag |= RACK_IS_PCM;
20947 		rack_log_pcm(rack, 5, len, rack->r_ctl.pcm_max_seg,  add_flag);
20948 	} else if (rack_verbose_logging) {
20949 		rack_log_pcm(rack, 6, len, rack->r_ctl.pcm_max_seg,  add_flag);
20950 	}
20951 
20952 	SOCKBUF_LOCK_ASSERT(sb);
20953 	if (len > 0) {
20954 		if (len >= segsiz)
20955 			tp->t_flags2 |= TF2_PLPMTU_MAXSEGSNT;
20956 		else
20957 			tp->t_flags2 &= ~TF2_PLPMTU_MAXSEGSNT;
20958 	}
20959 	/*
20960 	 * Before ESTABLISHED, force sending of initial options unless TCP
20961 	 * set not to do any options. NOTE: we assume that the IP/TCP header
20962 	 * plus TCP options always fit in a single mbuf, leaving room for a
20963 	 * maximum link header, i.e. max_linkhdr + sizeof (struct tcpiphdr)
20964 	 * + optlen <= MCLBYTES
20965 	 */
20966 	optlen = 0;
20967 #ifdef INET6
20968 	if (isipv6)
20969 		hdrlen = sizeof(struct ip6_hdr) + sizeof(struct tcphdr);
20970 	else
20971 #endif
20972 		hdrlen = sizeof(struct tcpiphdr);
20973 
20974 	/*
20975 	 * Ok what seq are we sending from. If we have
20976 	 * no rsm to use, then we look at various bits,
20977 	 * if we are putting out a SYN it will be ISS.
20978 	 * If we are retransmitting a FIN it will
20979 	 * be snd_max-1 else its snd_max.
20980 	 */
20981 	if (rsm == NULL) {
20982 		if (flags & TH_SYN)
20983 			rack_seq = tp->iss;
20984 		else if ((flags & TH_FIN) &&
20985 			 (tp->t_flags & TF_SENTFIN))
20986 			rack_seq = tp->snd_max - 1;
20987 		else
20988 			rack_seq = tp->snd_max;
20989 	} else {
20990 		rack_seq = rsm->r_start;
20991 	}
20992 	/*
20993 	 * Compute options for segment. We only have to care about SYN and
20994 	 * established connection segments.  Options for SYN-ACK segments
20995 	 * are handled in TCP syncache.
20996 	 */
20997 	to.to_flags = 0;
20998 	if ((tp->t_flags & TF_NOOPT) == 0) {
20999 		/* Maximum segment size. */
21000 		if (flags & TH_SYN) {
21001 			to.to_mss = tcp_mssopt(&inp->inp_inc);
21002 			if (tp->t_port)
21003 				to.to_mss -= V_tcp_udp_tunneling_overhead;
21004 			to.to_flags |= TOF_MSS;
21005 
21006 			/*
21007 			 * On SYN or SYN|ACK transmits on TFO connections,
21008 			 * only include the TFO option if it is not a
21009 			 * retransmit, as the presence of the TFO option may
21010 			 * have caused the original SYN or SYN|ACK to have
21011 			 * been dropped by a middlebox.
21012 			 */
21013 			if ((tp->t_flags & TF_FASTOPEN) &&
21014 			    (tp->t_rxtshift == 0)) {
21015 				if (tp->t_state == TCPS_SYN_RECEIVED) {
21016 					to.to_tfo_len = TCP_FASTOPEN_COOKIE_LEN;
21017 					to.to_tfo_cookie =
21018 						(u_int8_t *)&tp->t_tfo_cookie.server;
21019 					to.to_flags |= TOF_FASTOPEN;
21020 					wanted_cookie = 1;
21021 				} else if (tp->t_state == TCPS_SYN_SENT) {
21022 					to.to_tfo_len =
21023 						tp->t_tfo_client_cookie_len;
21024 					to.to_tfo_cookie =
21025 						tp->t_tfo_cookie.client;
21026 					to.to_flags |= TOF_FASTOPEN;
21027 					wanted_cookie = 1;
21028 					/*
21029 					 * If we wind up having more data to
21030 					 * send with the SYN than can fit in
21031 					 * one segment, don't send any more
21032 					 * until the SYN|ACK comes back from
21033 					 * the other end.
21034 					 */
21035 					sendalot = 0;
21036 				}
21037 			}
21038 		}
21039 		/* Window scaling. */
21040 		if ((flags & TH_SYN) && (tp->t_flags & TF_REQ_SCALE)) {
21041 			to.to_wscale = tp->request_r_scale;
21042 			to.to_flags |= TOF_SCALE;
21043 		}
21044 		/* Timestamps. */
21045 		if ((tp->t_flags & TF_RCVD_TSTMP) ||
21046 		    ((flags & TH_SYN) && (tp->t_flags & TF_REQ_TSTMP))) {
21047 			uint32_t ts_to_use;
21048 
21049 			if ((rack->r_rcvpath_rtt_up == 1) &&
21050 			    (ms_cts == rack->r_ctl.last_rcv_tstmp_for_rtt)) {
21051 				/*
21052 				 * When we are doing a rcv_rtt probe all
21053 				 * other timestamps use the next msec. This
21054 				 * is safe since our previous ack is in the
21055 				 * air and we will just have a few more
21056 				 * on the next ms. This assures that only
21057 				 * the one ack has the ms_cts that was on
21058 				 * our ack-probe.
21059 				 */
21060 				ts_to_use = ms_cts + 1;
21061 			} else {
21062 				ts_to_use = ms_cts;
21063 			}
21064 			to.to_tsval = ts_to_use + tp->ts_offset;
21065 			to.to_tsecr = tp->ts_recent;
21066 			to.to_flags |= TOF_TS;
21067 			if ((len == 0) &&
21068 			    (TCPS_HAVEESTABLISHED(tp->t_state)) &&
21069 			    ((ms_cts - rack->r_ctl.last_rcv_tstmp_for_rtt) > RCV_PATH_RTT_MS) &&
21070 			    (tp->snd_una == tp->snd_max) &&
21071 			    (flags & TH_ACK) &&
21072 			    (sbavail(sb) == 0) &&
21073 			    (rack->r_ctl.current_round != 0) &&
21074 			    ((flags & (TH_SYN|TH_FIN)) == 0) &&
21075 			    (rack->r_rcvpath_rtt_up == 0)) {
21076 				rack->r_ctl.last_rcv_tstmp_for_rtt = ms_cts;
21077 				rack->r_ctl.last_time_of_arm_rcv = cts;
21078 				rack->r_rcvpath_rtt_up = 1;
21079 				/* Subtract 1 from seq to force a response */
21080 				rack_seq--;
21081 			}
21082 		}
21083 		/* Set receive buffer autosizing timestamp. */
21084 		if (tp->rfbuf_ts == 0 &&
21085 		    (so->so_rcv.sb_flags & SB_AUTOSIZE)) {
21086 			tp->rfbuf_ts = ms_cts;
21087 		}
21088 		/* Selective ACK's. */
21089 		if (tp->t_flags & TF_SACK_PERMIT) {
21090 			if (flags & TH_SYN)
21091 				to.to_flags |= TOF_SACKPERM;
21092 			else if (TCPS_HAVEESTABLISHED(tp->t_state) &&
21093 				 tp->rcv_numsacks > 0) {
21094 				to.to_flags |= TOF_SACK;
21095 				to.to_nsacks = tp->rcv_numsacks;
21096 				to.to_sacks = (u_char *)tp->sackblks;
21097 			}
21098 		}
21099 #if defined(IPSEC_SUPPORT) || defined(TCP_SIGNATURE)
21100 		/* TCP-MD5 (RFC2385). */
21101 		if (tp->t_flags & TF_SIGNATURE)
21102 			to.to_flags |= TOF_SIGNATURE;
21103 #endif
21104 
21105 		/* Processing the options. */
21106 		hdrlen += optlen = tcp_addoptions(&to, opt);
21107 		/*
21108 		 * If we wanted a TFO option to be added, but it was unable
21109 		 * to fit, ensure no data is sent.
21110 		 */
21111 		if ((tp->t_flags & TF_FASTOPEN) && wanted_cookie &&
21112 		    !(to.to_flags & TOF_FASTOPEN))
21113 			len = 0;
21114 	}
21115 	if (tp->t_port) {
21116 		if (V_tcp_udp_tunneling_port == 0) {
21117 			/* The port was removed?? */
21118 			SOCK_SENDBUF_UNLOCK(so);
21119 #ifdef TCP_ACCOUNTING
21120 			crtsc = get_cyclecount();
21121 			if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
21122 				tp->tcp_cnt_counters[SND_OUT_FAIL]++;
21123 				tp->tcp_proc_time[SND_OUT_FAIL] += (crtsc - ts_val);
21124 			}
21125 			sched_unpin();
21126 #endif
21127 			return (EHOSTUNREACH);
21128 		}
21129 		hdrlen += sizeof(struct udphdr);
21130 	}
21131 #ifdef INET6
21132 	if (isipv6)
21133 		ipoptlen = ip6_optlen(inp);
21134 	else
21135 #endif
21136 		if (inp->inp_options)
21137 			ipoptlen = inp->inp_options->m_len -
21138 				offsetof(struct ipoption, ipopt_list);
21139 		else
21140 			ipoptlen = 0;
21141 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
21142 	ipoptlen += ipsec_optlen;
21143 #endif
21144 
21145 	/*
21146 	 * Adjust data length if insertion of options will bump the packet
21147 	 * length beyond the t_maxseg length. Clear the FIN bit because we
21148 	 * cut off the tail of the segment.
21149 	 */
21150 	if (len + optlen + ipoptlen > tp->t_maxseg) {
21151 		if (tso) {
21152 			uint32_t if_hw_tsomax;
21153 			uint32_t moff;
21154 			int32_t max_len;
21155 
21156 			/* extract TSO information */
21157 			if_hw_tsomax = tp->t_tsomax;
21158 			if_hw_tsomaxsegcount = tp->t_tsomaxsegcount;
21159 			if_hw_tsomaxsegsize = tp->t_tsomaxsegsize;
21160 			KASSERT(ipoptlen == 0,
21161 				("%s: TSO can't do IP options", __func__));
21162 
21163 			/*
21164 			 * Check if we should limit by maximum payload
21165 			 * length:
21166 			 */
21167 			if (if_hw_tsomax != 0) {
21168 				/* compute maximum TSO length */
21169 				max_len = (if_hw_tsomax - hdrlen -
21170 					   max_linkhdr);
21171 				if (max_len <= 0) {
21172 					len = 0;
21173 				} else if (len > max_len) {
21174 					if (doing_tlp == 0)
21175 						sendalot = 1;
21176 					len = max_len;
21177 					mark = 2;
21178 				}
21179 			}
21180 			/*
21181 			 * Prevent the last segment from being fractional
21182 			 * unless the send sockbuf can be emptied:
21183 			 */
21184 			max_len = (tp->t_maxseg - optlen);
21185 			if ((sb_offset + len) < sbavail(sb)) {
21186 				moff = len % (u_int)max_len;
21187 				if (moff != 0) {
21188 					mark = 3;
21189 					len -= moff;
21190 				}
21191 			}
21192 			/*
21193 			 * In case there are too many small fragments don't
21194 			 * use TSO:
21195 			 */
21196 			if (len <= max_len) {
21197 				mark = 4;
21198 				tso = 0;
21199 			}
21200 			/*
21201 			 * Send the FIN in a separate segment after the bulk
21202 			 * sending is done. We don't trust the TSO
21203 			 * implementations to clear the FIN flag on all but
21204 			 * the last segment.
21205 			 */
21206 			if (tp->t_flags & TF_NEEDFIN) {
21207 				sendalot = 4;
21208 			}
21209 		} else {
21210 			mark = 5;
21211 			if (optlen + ipoptlen >= tp->t_maxseg) {
21212 				/*
21213 				 * Since we don't have enough space to put
21214 				 * the IP header chain and the TCP header in
21215 				 * one packet as required by RFC 7112, don't
21216 				 * send it. Also ensure that at least one
21217 				 * byte of the payload can be put into the
21218 				 * TCP segment.
21219 				 */
21220 				SOCK_SENDBUF_UNLOCK(so);
21221 				error = EMSGSIZE;
21222 				sack_rxmit = 0;
21223 				goto out;
21224 			}
21225 			len = tp->t_maxseg - optlen - ipoptlen;
21226 			sendalot = 5;
21227 		}
21228 	} else {
21229 		tso = 0;
21230 		mark = 6;
21231 	}
21232 	KASSERT(len + hdrlen + ipoptlen <= IP_MAXPACKET,
21233 		("%s: len > IP_MAXPACKET", __func__));
21234 #ifdef DIAGNOSTIC
21235 #ifdef INET6
21236 	if (max_linkhdr + hdrlen > MCLBYTES)
21237 #else
21238 		if (max_linkhdr + hdrlen > MHLEN)
21239 #endif
21240 			panic("tcphdr too big");
21241 #endif
21242 
21243 	/*
21244 	 * This KASSERT is here to catch edge cases at a well defined place.
21245 	 * Before, those had triggered (random) panic conditions further
21246 	 * down.
21247 	 */
21248 	KASSERT(len >= 0, ("[%s:%d]: len < 0", __func__, __LINE__));
21249 	if ((len == 0) &&
21250 	    (flags & TH_FIN) &&
21251 	    (sbused(sb))) {
21252 		/*
21253 		 * We have outstanding data, don't send a fin by itself!.
21254 		 *
21255 		 * Check to see if we need to send a challenge ack.
21256 		 */
21257 		if ((sbused(sb) == (tp->snd_max - tp->snd_una)) &&
21258 		    ((tp->snd_max - tp->snd_una) <= segsiz)) {
21259 			/*
21260 			 * Ok less than or right at a MSS is
21261 			 * outstanding. The original FreeBSD stack would
21262 			 * have sent a FIN, which can speed things up for
21263 			 * a transactional application doing a MSG_WAITALL.
21264 			 * To speed things up since we do *not* send a FIN
21265 			 * if data is outstanding, we send a "challenge ack".
21266 			 * The idea behind that is instead of having to have
21267 			 * the peer wait for the delayed-ack timer to run off
21268 			 * we send an ack that makes the peer send us an ack.
21269 			 */
21270 			rack_send_ack_challange(rack);
21271 		}
21272 		goto just_return;
21273 	}
21274 	/*
21275 	 * Grab a header mbuf, attaching a copy of data to be transmitted,
21276 	 * and initialize the header from the template for sends on this
21277 	 * connection.
21278 	 */
21279 	hw_tls = tp->t_nic_ktls_xmit != 0;
21280 	if (len) {
21281 		uint32_t max_val;
21282 		uint32_t moff;
21283 
21284 		if (pace_max_seg)
21285 			max_val = pace_max_seg;
21286 		else
21287 			max_val = len;
21288 		/*
21289 		 * We allow a limit on sending with hptsi.
21290 		 */
21291 		if (len > max_val) {
21292 			mark = 7;
21293 			len = max_val;
21294 		}
21295 #ifdef INET6
21296 		if (MHLEN < hdrlen + max_linkhdr)
21297 			m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR);
21298 		else
21299 #endif
21300 			m = m_gethdr(M_NOWAIT, MT_DATA);
21301 
21302 		if (m == NULL) {
21303 			SOCK_SENDBUF_UNLOCK(so);
21304 			error = ENOBUFS;
21305 			sack_rxmit = 0;
21306 			goto out;
21307 		}
21308 		m->m_data += max_linkhdr;
21309 		m->m_len = hdrlen;
21310 
21311 		/*
21312 		 * Start the m_copy functions from the closest mbuf to the
21313 		 * sb_offset in the socket buffer chain.
21314 		 */
21315 		mb = sbsndptr_noadv(sb, sb_offset, &moff);
21316 		s_mb = mb;
21317 		s_moff = moff;
21318 		if (len <= MHLEN - hdrlen - max_linkhdr && !hw_tls) {
21319 			m_copydata(mb, moff, (int)len,
21320 				   mtod(m, caddr_t)+hdrlen);
21321 			/*
21322 			 * If we are not retransmitting advance the
21323 			 * sndptr to help remember the next place in
21324 			 * the sb.
21325 			 */
21326 			if (rsm == NULL)
21327 				sbsndptr_adv(sb, mb, len);
21328 			m->m_len += len;
21329 		} else {
21330 			struct sockbuf *msb;
21331 
21332 			/*
21333 			 * If we are not retransmitting pass in msb so
21334 			 * the socket buffer can be advanced. Otherwise
21335 			 * set it to NULL if its a retransmission since
21336 			 * we don't want to change the sb remembered
21337 			 * location.
21338 			 */
21339 			if (rsm == NULL)
21340 				msb = sb;
21341 			else
21342 				msb = NULL;
21343 			m->m_next = tcp_m_copym(
21344 				mb, moff, &len,
21345 				if_hw_tsomaxsegcount, if_hw_tsomaxsegsize, msb,
21346 				((rsm == NULL) ? hw_tls : 0));
21347 			if (len <= (tp->t_maxseg - optlen)) {
21348 				/*
21349 				 * Must have ran out of mbufs for the copy
21350 				 * shorten it to no longer need tso. Lets
21351 				 * not put on sendalot since we are low on
21352 				 * mbufs.
21353 				 */
21354 				tso = 0;
21355 			}
21356 			if (m->m_next == NULL) {
21357 				SOCK_SENDBUF_UNLOCK(so);
21358 				(void)m_free(m);
21359 				error = ENOBUFS;
21360 				sack_rxmit = 0;
21361 				goto out;
21362 			}
21363 		}
21364 		if (sack_rxmit) {
21365 			if (rsm && (rsm->r_flags & RACK_TLP)) {
21366 				/*
21367 				 * TLP should not count in retran count, but
21368 				 * in its own bin
21369 				 */
21370 				counter_u64_add(rack_tlp_retran, 1);
21371 				counter_u64_add(rack_tlp_retran_bytes, len);
21372 			} else {
21373 				tp->t_sndrexmitpack++;
21374 				KMOD_TCPSTAT_INC(tcps_sndrexmitpack);
21375 				KMOD_TCPSTAT_ADD(tcps_sndrexmitbyte, len);
21376 			}
21377 #ifdef STATS
21378 			stats_voi_update_abs_u32(tp->t_stats, VOI_TCP_RETXPB,
21379 						 len);
21380 #endif
21381 		} else {
21382 			KMOD_TCPSTAT_INC(tcps_sndpack);
21383 			KMOD_TCPSTAT_ADD(tcps_sndbyte, len);
21384 #ifdef STATS
21385 			stats_voi_update_abs_u64(tp->t_stats, VOI_TCP_TXPB,
21386 						 len);
21387 #endif
21388 		}
21389 		/*
21390 		 * If we're sending everything we've got, set PUSH. (This
21391 		 * will keep happy those implementations which only give
21392 		 * data to the user when a buffer fills or a PUSH comes in.)
21393 		 */
21394 		if (sb_offset + len == sbused(sb) &&
21395 		    sbused(sb) &&
21396 		    !(flags & TH_SYN)) {
21397 			flags |= TH_PUSH;
21398 			add_flag |= RACK_HAD_PUSH;
21399 		}
21400 		SOCK_SENDBUF_UNLOCK(so);
21401 	} else {
21402 		SOCK_SENDBUF_UNLOCK(so);
21403 		if (tp->t_flags & TF_ACKNOW)
21404 			KMOD_TCPSTAT_INC(tcps_sndacks);
21405 		else if (flags & (TH_SYN | TH_FIN | TH_RST))
21406 			KMOD_TCPSTAT_INC(tcps_sndctrl);
21407 		else
21408 			KMOD_TCPSTAT_INC(tcps_sndwinup);
21409 
21410 		m = m_gethdr(M_NOWAIT, MT_DATA);
21411 		if (m == NULL) {
21412 			error = ENOBUFS;
21413 			sack_rxmit = 0;
21414 			goto out;
21415 		}
21416 #ifdef INET6
21417 		if (isipv6 && (MHLEN < hdrlen + max_linkhdr) &&
21418 		    MHLEN >= hdrlen) {
21419 			M_ALIGN(m, hdrlen);
21420 		} else
21421 #endif
21422 			m->m_data += max_linkhdr;
21423 		m->m_len = hdrlen;
21424 	}
21425 	SOCK_SENDBUF_UNLOCK_ASSERT(so);
21426 	m->m_pkthdr.rcvif = (struct ifnet *)0;
21427 #ifdef MAC
21428 	mac_inpcb_create_mbuf(inp, m);
21429 #endif
21430 	if ((ipoptlen == 0) && (rack->r_ctl.fsb.tcp_ip_hdr) &&  rack->r_fsb_inited) {
21431 #ifdef INET6
21432 		if (isipv6)
21433 			ip6 = (struct ip6_hdr *)rack->r_ctl.fsb.tcp_ip_hdr;
21434 		else
21435 #endif				/* INET6 */
21436 #ifdef INET
21437 			ip = (struct ip *)rack->r_ctl.fsb.tcp_ip_hdr;
21438 #endif
21439 		th = rack->r_ctl.fsb.th;
21440 		udp = rack->r_ctl.fsb.udp;
21441 		if (udp) {
21442 #ifdef INET6
21443 			if (isipv6)
21444 				ulen = hdrlen + len - sizeof(struct ip6_hdr);
21445 			else
21446 #endif				/* INET6 */
21447 				ulen = hdrlen + len - sizeof(struct ip);
21448 			udp->uh_ulen = htons(ulen);
21449 		}
21450 	} else {
21451 #ifdef INET6
21452 		if (isipv6) {
21453 			ip6 = mtod(m, struct ip6_hdr *);
21454 			if (tp->t_port) {
21455 				udp = (struct udphdr *)((caddr_t)ip6 + sizeof(struct ip6_hdr));
21456 				udp->uh_sport = htons(V_tcp_udp_tunneling_port);
21457 				udp->uh_dport = tp->t_port;
21458 				ulen = hdrlen + len - sizeof(struct ip6_hdr);
21459 				udp->uh_ulen = htons(ulen);
21460 				th = (struct tcphdr *)(udp + 1);
21461 			} else
21462 				th = (struct tcphdr *)(ip6 + 1);
21463 			tcpip_fillheaders(inp, tp->t_port, ip6, th);
21464 		} else
21465 #endif				/* INET6 */
21466 		{
21467 #ifdef INET
21468 			ip = mtod(m, struct ip *);
21469 			if (tp->t_port) {
21470 				udp = (struct udphdr *)((caddr_t)ip + sizeof(struct ip));
21471 				udp->uh_sport = htons(V_tcp_udp_tunneling_port);
21472 				udp->uh_dport = tp->t_port;
21473 				ulen = hdrlen + len - sizeof(struct ip);
21474 				udp->uh_ulen = htons(ulen);
21475 				th = (struct tcphdr *)(udp + 1);
21476 			} else
21477 				th = (struct tcphdr *)(ip + 1);
21478 			tcpip_fillheaders(inp, tp->t_port, ip, th);
21479 #endif
21480 		}
21481 	}
21482 	/*
21483 	 * If we are starting a connection, send ECN setup SYN packet. If we
21484 	 * are on a retransmit, we may resend those bits a number of times
21485 	 * as per RFC 3168.
21486 	 */
21487 	if (tp->t_state == TCPS_SYN_SENT && V_tcp_do_ecn) {
21488 		flags |= tcp_ecn_output_syn_sent(tp);
21489 	}
21490 	/* Also handle parallel SYN for ECN */
21491 	if (TCPS_HAVERCVDSYN(tp->t_state) &&
21492 	    (tp->t_flags2 & (TF2_ECN_PERMIT | TF2_ACE_PERMIT))) {
21493 		int ect = tcp_ecn_output_established(tp, &flags, len, sack_rxmit);
21494 		if ((tp->t_state == TCPS_SYN_RECEIVED) &&
21495 		    (tp->t_flags2 & TF2_ECN_SND_ECE))
21496 			tp->t_flags2 &= ~TF2_ECN_SND_ECE;
21497 #ifdef INET6
21498 		if (isipv6) {
21499 			ip6->ip6_flow &= ~htonl(IPTOS_ECN_MASK << 20);
21500 			ip6->ip6_flow |= htonl(ect << 20);
21501 		}
21502 		else
21503 #endif
21504 		{
21505 #ifdef INET
21506 			ip->ip_tos &= ~IPTOS_ECN_MASK;
21507 			ip->ip_tos |= ect;
21508 #endif
21509 		}
21510 	}
21511 	th->th_seq = htonl(rack_seq);
21512 	th->th_ack = htonl(tp->rcv_nxt);
21513 	tcp_set_flags(th, flags);
21514 	/*
21515 	 * Calculate receive window.  Don't shrink window, but avoid silly
21516 	 * window syndrome.
21517 	 * If a RST segment is sent, advertise a window of zero.
21518 	 */
21519 	if (flags & TH_RST) {
21520 		recwin = 0;
21521 	} else {
21522 		if (recwin < (long)(so->so_rcv.sb_hiwat / 4) &&
21523 		    recwin < (long)segsiz) {
21524 			recwin = 0;
21525 		}
21526 		if (SEQ_GT(tp->rcv_adv, tp->rcv_nxt) &&
21527 		    recwin < (long)(tp->rcv_adv - tp->rcv_nxt))
21528 			recwin = (long)(tp->rcv_adv - tp->rcv_nxt);
21529 	}
21530 
21531 	/*
21532 	 * According to RFC1323 the window field in a SYN (i.e., a <SYN> or
21533 	 * <SYN,ACK>) segment itself is never scaled.  The <SYN,ACK> case is
21534 	 * handled in syncache.
21535 	 */
21536 	if (flags & TH_SYN)
21537 		th->th_win = htons((u_short)
21538 				   (min(sbspace(&so->so_rcv), TCP_MAXWIN)));
21539 	else {
21540 		/* Avoid shrinking window with window scaling. */
21541 		recwin = roundup2(recwin, 1 << tp->rcv_scale);
21542 		th->th_win = htons((u_short)(recwin >> tp->rcv_scale));
21543 	}
21544 	/*
21545 	 * Adjust the RXWIN0SENT flag - indicate that we have advertised a 0
21546 	 * window.  This may cause the remote transmitter to stall.  This
21547 	 * flag tells soreceive() to disable delayed acknowledgements when
21548 	 * draining the buffer.  This can occur if the receiver is
21549 	 * attempting to read more data than can be buffered prior to
21550 	 * transmitting on the connection.
21551 	 */
21552 	if (th->th_win == 0) {
21553 		tp->t_sndzerowin++;
21554 		tp->t_flags |= TF_RXWIN0SENT;
21555 	} else
21556 		tp->t_flags &= ~TF_RXWIN0SENT;
21557 	tp->snd_up = tp->snd_una;	/* drag it along, its deprecated */
21558 	/* Now are we using fsb?, if so copy the template data to the mbuf */
21559 	if ((ipoptlen == 0) && (rack->r_ctl.fsb.tcp_ip_hdr) && rack->r_fsb_inited) {
21560 		uint8_t *cpto;
21561 
21562 		cpto = mtod(m, uint8_t *);
21563 		memcpy(cpto, rack->r_ctl.fsb.tcp_ip_hdr, rack->r_ctl.fsb.tcp_ip_hdr_len);
21564 		/*
21565 		 * We have just copied in:
21566 		 * IP/IP6
21567 		 * <optional udphdr>
21568 		 * tcphdr (no options)
21569 		 *
21570 		 * We need to grab the correct pointers into the mbuf
21571 		 * for both the tcp header, and possibly the udp header (if tunneling).
21572 		 * We do this by using the offset in the copy buffer and adding it
21573 		 * to the mbuf base pointer (cpto).
21574 		 */
21575 #ifdef INET6
21576 		if (isipv6)
21577 			ip6 = mtod(m, struct ip6_hdr *);
21578 		else
21579 #endif				/* INET6 */
21580 #ifdef INET
21581 			ip = mtod(m, struct ip *);
21582 #endif
21583 		th = (struct tcphdr *)(cpto + ((uint8_t *)rack->r_ctl.fsb.th - rack->r_ctl.fsb.tcp_ip_hdr));
21584 		/* If we have a udp header lets set it into the mbuf as well */
21585 		if (udp)
21586 			udp = (struct udphdr *)(cpto + ((uint8_t *)rack->r_ctl.fsb.udp - rack->r_ctl.fsb.tcp_ip_hdr));
21587 	}
21588 	if (optlen) {
21589 		bcopy(opt, th + 1, optlen);
21590 		th->th_off = (sizeof(struct tcphdr) + optlen) >> 2;
21591 	}
21592 	/*
21593 	 * Put TCP length in extended header, and then checksum extended
21594 	 * header and data.
21595 	 */
21596 	m->m_pkthdr.len = hdrlen + len;	/* in6_cksum() need this */
21597 #if defined(IPSEC_SUPPORT) || defined(TCP_SIGNATURE)
21598 	if (to.to_flags & TOF_SIGNATURE) {
21599 		/*
21600 		 * Calculate MD5 signature and put it into the place
21601 		 * determined before.
21602 		 * NOTE: since TCP options buffer doesn't point into
21603 		 * mbuf's data, calculate offset and use it.
21604 		 */
21605 		if (!TCPMD5_ENABLED() || TCPMD5_OUTPUT(m, th,
21606 						       (u_char *)(th + 1) + (to.to_signature - opt)) != 0) {
21607 			/*
21608 			 * Do not send segment if the calculation of MD5
21609 			 * digest has failed.
21610 			 */
21611 			goto out;
21612 		}
21613 	}
21614 #endif
21615 #ifdef INET6
21616 	if (isipv6) {
21617 		/*
21618 		 * ip6_plen is not need to be filled now, and will be filled
21619 		 * in ip6_output.
21620 		 */
21621 		if (tp->t_port) {
21622 			m->m_pkthdr.csum_flags = CSUM_UDP_IPV6;
21623 			m->m_pkthdr.csum_data = offsetof(struct udphdr, uh_sum);
21624 			udp->uh_sum = in6_cksum_pseudo(ip6, ulen, IPPROTO_UDP, 0);
21625 			th->th_sum = htons(0);
21626 			UDPSTAT_INC(udps_opackets);
21627 		} else {
21628 			m->m_pkthdr.csum_flags = CSUM_TCP_IPV6;
21629 			m->m_pkthdr.csum_data = offsetof(struct tcphdr, th_sum);
21630 			th->th_sum = in6_cksum_pseudo(ip6,
21631 						      sizeof(struct tcphdr) + optlen + len, IPPROTO_TCP,
21632 						      0);
21633 		}
21634 	}
21635 #endif
21636 #if defined(INET6) && defined(INET)
21637 	else
21638 #endif
21639 #ifdef INET
21640 	{
21641 		if (tp->t_port) {
21642 			m->m_pkthdr.csum_flags = CSUM_UDP;
21643 			m->m_pkthdr.csum_data = offsetof(struct udphdr, uh_sum);
21644 			udp->uh_sum = in_pseudo(ip->ip_src.s_addr,
21645 						ip->ip_dst.s_addr, htons(ulen + IPPROTO_UDP));
21646 			th->th_sum = htons(0);
21647 			UDPSTAT_INC(udps_opackets);
21648 		} else {
21649 			m->m_pkthdr.csum_flags = CSUM_TCP;
21650 			m->m_pkthdr.csum_data = offsetof(struct tcphdr, th_sum);
21651 			th->th_sum = in_pseudo(ip->ip_src.s_addr,
21652 					       ip->ip_dst.s_addr, htons(sizeof(struct tcphdr) +
21653 									IPPROTO_TCP + len + optlen));
21654 		}
21655 		/* IP version must be set here for ipv4/ipv6 checking later */
21656 		KASSERT(ip->ip_v == IPVERSION,
21657 			("%s: IP version incorrect: %d", __func__, ip->ip_v));
21658 	}
21659 #endif
21660 	/*
21661 	 * Enable TSO and specify the size of the segments. The TCP pseudo
21662 	 * header checksum is always provided. XXX: Fixme: This is currently
21663 	 * not the case for IPv6.
21664 	 */
21665 	if (tso) {
21666 		/*
21667 		 * Here we must use t_maxseg and the optlen since
21668 		 * the optlen may include SACK's (or DSACK).
21669 		 */
21670 		KASSERT(len > tp->t_maxseg - optlen,
21671 			("%s: len <= tso_segsz", __func__));
21672 		m->m_pkthdr.csum_flags |= CSUM_TSO;
21673 		m->m_pkthdr.tso_segsz = tp->t_maxseg - optlen;
21674 	}
21675 	KASSERT(len + hdrlen == m_length(m, NULL),
21676 		("%s: mbuf chain different than expected: %d + %u != %u",
21677 		 __func__, len, hdrlen, m_length(m, NULL)));
21678 
21679 #ifdef TCP_HHOOK
21680 	/* Run HHOOK_TCP_ESTABLISHED_OUT helper hooks. */
21681 	hhook_run_tcp_est_out(tp, th, &to, len, tso);
21682 #endif
21683 	if ((rack->r_ctl.crte != NULL) &&
21684 	    (rack->rc_hw_nobuf == 0) &&
21685 	    tcp_bblogging_on(tp)) {
21686 		rack_log_queue_level(tp, rack, len, &tv, cts);
21687 	}
21688 	/* We're getting ready to send; log now. */
21689 	if (tcp_bblogging_on(rack->rc_tp)) {
21690 		union tcp_log_stackspecific log;
21691 
21692 		memset(&log, 0, sizeof(log));
21693 		log.u_bbr.inhpts = tcp_in_hpts(rack->rc_tp);
21694 		if (rack->rack_no_prr)
21695 			log.u_bbr.flex1 = 0;
21696 		else
21697 			log.u_bbr.flex1 = rack->r_ctl.rc_prr_sndcnt;
21698 		log.u_bbr.flex2 = rack->r_ctl.rc_pace_min_segs;
21699 		log.u_bbr.flex3 = rack->r_ctl.rc_pace_max_segs;
21700 		log.u_bbr.flex4 = orig_len;
21701 		/* Save off the early/late values */
21702 		log.u_bbr.flex6 = rack->r_ctl.rc_agg_early;
21703 		log.u_bbr.applimited = rack->r_ctl.rc_agg_delayed;
21704 		log.u_bbr.bw_inuse = rack_get_bw(rack);
21705 		log.u_bbr.cur_del_rate = rack->r_ctl.gp_bw;
21706 		log.u_bbr.flex8 = 0;
21707 		if (rsm) {
21708 			if (rsm->r_flags & RACK_RWND_COLLAPSED) {
21709 				rack_log_collapse(rack, rsm->r_start, rsm->r_end, 0, __LINE__, 5, rsm->r_flags, rsm);
21710 				counter_u64_add(rack_collapsed_win_rxt, 1);
21711 				counter_u64_add(rack_collapsed_win_rxt_bytes, (rsm->r_end - rsm->r_start));
21712 			}
21713 			if (doing_tlp)
21714 				log.u_bbr.flex8 = 2;
21715 			else
21716 				log.u_bbr.flex8 = 1;
21717 		} else {
21718 			if (doing_tlp)
21719 				log.u_bbr.flex8 = 3;
21720 		}
21721 		log.u_bbr.pacing_gain = rack_get_output_gain(rack, rsm);
21722 		log.u_bbr.flex7 = mark;
21723 		log.u_bbr.flex7 <<= 8;
21724 		log.u_bbr.flex7 |= pass;
21725 		log.u_bbr.pkts_out = tp->t_maxseg;
21726 		log.u_bbr.timeStamp = cts;
21727 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
21728 		if (rsm && (rsm->r_rtr_cnt > 0)) {
21729 			/*
21730 			 * When we have a retransmit we want to log the
21731 			 * burst at send and flight at send from before.
21732 			 */
21733 			log.u_bbr.flex5 = rsm->r_fas;
21734 			log.u_bbr.bbr_substate = rsm->r_bas;
21735 		} else {
21736 			/*
21737 			 * New transmits we log in flex5 the inflight again as
21738 			 * well as the number of segments in our send in the
21739 			 * substate field.
21740 			 */
21741 			log.u_bbr.flex5 = log.u_bbr.inflight;
21742 			log.u_bbr.bbr_substate = (uint8_t)((len + segsiz - 1)/segsiz);
21743 		}
21744 		log.u_bbr.lt_epoch = cwnd_to_use;
21745 		log.u_bbr.delivered = sendalot;
21746 		log.u_bbr.rttProp = (uintptr_t)rsm;
21747 		log.u_bbr.pkt_epoch = __LINE__;
21748 		if (rsm) {
21749 			log.u_bbr.delRate = rsm->r_flags;
21750 			log.u_bbr.delRate <<= 31;
21751 			log.u_bbr.delRate |= rack->r_must_retran;
21752 			log.u_bbr.delRate <<= 1;
21753 			log.u_bbr.delRate |= (sack_rxmit & 0x00000001);
21754 		} else {
21755 			log.u_bbr.delRate = rack->r_must_retran;
21756 			log.u_bbr.delRate <<= 1;
21757 			log.u_bbr.delRate |= (sack_rxmit & 0x00000001);
21758 		}
21759 		lgb = tcp_log_event(tp, th, &so->so_rcv, &so->so_snd, TCP_LOG_OUT, ERRNO_UNK,
21760 				    len, &log, false, NULL, __func__, __LINE__, &tv);
21761 	} else
21762 		lgb = NULL;
21763 
21764 	/*
21765 	 * Fill in IP length and desired time to live and send to IP level.
21766 	 * There should be a better way to handle ttl and tos; we could keep
21767 	 * them in the template, but need a way to checksum without them.
21768 	 */
21769 	/*
21770 	 * m->m_pkthdr.len should have been set before cksum calcuration,
21771 	 * because in6_cksum() need it.
21772 	 */
21773 #ifdef INET6
21774 	if (isipv6) {
21775 		/*
21776 		 * we separately set hoplimit for every segment, since the
21777 		 * user might want to change the value via setsockopt. Also,
21778 		 * desired default hop limit might be changed via Neighbor
21779 		 * Discovery.
21780 		 */
21781 		rack->r_ctl.fsb.hoplimit = ip6->ip6_hlim = in6_selecthlim(inp, NULL);
21782 
21783 		/*
21784 		 * Set the packet size here for the benefit of DTrace
21785 		 * probes. ip6_output() will set it properly; it's supposed
21786 		 * to include the option header lengths as well.
21787 		 */
21788 		ip6->ip6_plen = htons(m->m_pkthdr.len - sizeof(*ip6));
21789 
21790 		if (V_path_mtu_discovery && tp->t_maxseg > V_tcp_minmss)
21791 			tp->t_flags2 |= TF2_PLPMTU_PMTUD;
21792 		else
21793 			tp->t_flags2 &= ~TF2_PLPMTU_PMTUD;
21794 
21795 		if (tp->t_state == TCPS_SYN_SENT)
21796 			TCP_PROBE5(connect__request, NULL, tp, ip6, tp, th);
21797 
21798 		TCP_PROBE5(send, NULL, tp, ip6, tp, th);
21799 		/* TODO: IPv6 IP6TOS_ECT bit on */
21800 		error = ip6_output(m,
21801 				   inp->in6p_outputopts,
21802 				   &inp->inp_route6,
21803 				   ((rsm || sack_rxmit) ? IP_NO_SND_TAG_RL : 0),
21804 				   NULL, NULL, inp);
21805 
21806 		if (error == EMSGSIZE && inp->inp_route6.ro_nh != NULL)
21807 			mtu = inp->inp_route6.ro_nh->nh_mtu;
21808 	}
21809 #endif				/* INET6 */
21810 #if defined(INET) && defined(INET6)
21811 	else
21812 #endif
21813 #ifdef INET
21814 	{
21815 		ip->ip_len = htons(m->m_pkthdr.len);
21816 #ifdef INET6
21817 		if (inp->inp_vflag & INP_IPV6PROTO)
21818 			ip->ip_ttl = in6_selecthlim(inp, NULL);
21819 #endif				/* INET6 */
21820 		rack->r_ctl.fsb.hoplimit = ip->ip_ttl;
21821 		/*
21822 		 * If we do path MTU discovery, then we set DF on every
21823 		 * packet. This might not be the best thing to do according
21824 		 * to RFC3390 Section 2. However the tcp hostcache migitates
21825 		 * the problem so it affects only the first tcp connection
21826 		 * with a host.
21827 		 *
21828 		 * NB: Don't set DF on small MTU/MSS to have a safe
21829 		 * fallback.
21830 		 */
21831 		if (V_path_mtu_discovery && tp->t_maxseg > V_tcp_minmss) {
21832 			tp->t_flags2 |= TF2_PLPMTU_PMTUD;
21833 			if (tp->t_port == 0 || len < V_tcp_minmss) {
21834 				ip->ip_off |= htons(IP_DF);
21835 			}
21836 		} else {
21837 			tp->t_flags2 &= ~TF2_PLPMTU_PMTUD;
21838 		}
21839 
21840 		if (tp->t_state == TCPS_SYN_SENT)
21841 			TCP_PROBE5(connect__request, NULL, tp, ip, tp, th);
21842 
21843 		TCP_PROBE5(send, NULL, tp, ip, tp, th);
21844 
21845 		error = ip_output(m,
21846 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
21847 				  inp->inp_options,
21848 #else
21849 				  NULL,
21850 #endif
21851 				  &inp->inp_route,
21852 				  ((rsm || sack_rxmit) ? IP_NO_SND_TAG_RL : 0), 0,
21853 				  inp);
21854 		if (error == EMSGSIZE && inp->inp_route.ro_nh != NULL)
21855 			mtu = inp->inp_route.ro_nh->nh_mtu;
21856 	}
21857 #endif				/* INET */
21858 	if (lgb) {
21859 		lgb->tlb_errno = error;
21860 		lgb = NULL;
21861 	}
21862 
21863 out:
21864 	/*
21865 	 * In transmit state, time the transmission and arrange for the
21866 	 * retransmit.  In persist state, just set snd_max.
21867 	 */
21868 	if ((rsm == NULL) &&  doing_tlp)
21869 		add_flag |= RACK_TLP;
21870 	rack_log_output(tp, &to, len, rack_seq, (uint8_t) flags, error,
21871 			rack_to_usec_ts(&tv),
21872 			rsm, add_flag, s_mb, s_moff, hw_tls, segsiz);
21873 	if (error == 0) {
21874 		if (add_flag & RACK_IS_PCM) {
21875 			/* We just launched a PCM */
21876 			/* rrs here log */
21877 			rack->pcm_in_progress = 1;
21878 			rack->pcm_needed = 0;
21879 			rack_log_pcm(rack, 7, len, rack->r_ctl.pcm_max_seg,  add_flag);
21880 		}
21881 		if (rsm == NULL) {
21882 			if (rack->lt_bw_up == 0) {
21883 				rack->r_ctl.lt_timemark = tcp_tv_to_lusec(&tv);
21884 				rack->r_ctl.lt_seq = tp->snd_una;
21885 				rack->lt_bw_up = 1;
21886 			} else if (((rack_seq + len) - rack->r_ctl.lt_seq) > 0x7fffffff) {
21887 				/*
21888 				 * Need to record what we have since we are
21889 				 * approaching seq wrap.
21890 				 */
21891 				uint64_t tmark;
21892 
21893 				rack->r_ctl.lt_bw_bytes += (tp->snd_una - rack->r_ctl.lt_seq);
21894 				rack->r_ctl.lt_seq = tp->snd_una;
21895 				tmark = tcp_get_u64_usecs(&tv);
21896 				if (tmark > rack->r_ctl.lt_timemark) {
21897 					rack->r_ctl.lt_bw_time += (tmark - rack->r_ctl.lt_timemark);
21898 					rack->r_ctl.lt_timemark = tmark;
21899 				}
21900 			}
21901 		}
21902 		rack->forced_ack = 0;	/* If we send something zap the FA flag */
21903 		counter_u64_add(rack_total_bytes, len);
21904 		tcp_account_for_send(tp, len, (rsm != NULL), doing_tlp, hw_tls);
21905 		if (rsm && doing_tlp) {
21906 			rack->rc_last_sent_tlp_past_cumack = 0;
21907 			rack->rc_last_sent_tlp_seq_valid = 1;
21908 			rack->r_ctl.last_sent_tlp_seq = rsm->r_start;
21909 			rack->r_ctl.last_sent_tlp_len = rsm->r_end - rsm->r_start;
21910 		}
21911 		if (rack->rc_hw_nobuf) {
21912 			rack->rc_hw_nobuf = 0;
21913 			rack->r_ctl.rc_agg_delayed = 0;
21914 			rack->r_early = 0;
21915 			rack->r_late = 0;
21916 			rack->r_ctl.rc_agg_early = 0;
21917 		}
21918 		if (rsm && (doing_tlp == 0)) {
21919 			/* Set we retransmitted */
21920 			rack->rc_gp_saw_rec = 1;
21921 		} else {
21922 			if (cwnd_to_use > tp->snd_ssthresh) {
21923 				/* Set we sent in CA */
21924 				rack->rc_gp_saw_ca = 1;
21925 			} else {
21926 				/* Set we sent in SS */
21927 				rack->rc_gp_saw_ss = 1;
21928 			}
21929 		}
21930 		if (TCPS_HAVEESTABLISHED(tp->t_state) &&
21931 		    (tp->t_flags & TF_SACK_PERMIT) &&
21932 		    tp->rcv_numsacks > 0)
21933 			tcp_clean_dsack_blocks(tp);
21934 		tot_len_this_send += len;
21935 		if (len == 0) {
21936 			counter_u64_add(rack_out_size[TCP_MSS_ACCT_SNDACK], 1);
21937 		} else {
21938 			int idx;
21939 
21940 			idx = (len / segsiz) + 3;
21941 			if (idx >= TCP_MSS_ACCT_ATIMER)
21942 				counter_u64_add(rack_out_size[(TCP_MSS_ACCT_ATIMER-1)], 1);
21943 			else
21944 				counter_u64_add(rack_out_size[idx], 1);
21945 		}
21946 	}
21947 	if ((rack->rack_no_prr == 0) &&
21948 	    sub_from_prr &&
21949 	    (error == 0)) {
21950 		if (rack->r_ctl.rc_prr_sndcnt >= len)
21951 			rack->r_ctl.rc_prr_sndcnt -= len;
21952 		else
21953 			rack->r_ctl.rc_prr_sndcnt = 0;
21954 	}
21955 	sub_from_prr = 0;
21956 	if (rsm != NULL) {
21957 		if (doing_tlp)
21958 			/* Make sure the TLP is added */
21959 			rsm->r_flags |= RACK_TLP;
21960 		else
21961 			/* If its a resend without TLP then it must not have the flag */
21962 			rsm->r_flags &= ~RACK_TLP;
21963  	}
21964 	if ((error == 0) &&
21965 	    (len > 0) &&
21966 	    (tp->snd_una == tp->snd_max))
21967 		rack->r_ctl.rc_tlp_rxt_last_time = cts;
21968 
21969 	{
21970 		/*
21971 		 * This block is not associated with the above error == 0 test.
21972 		 * It is used to advance snd_max if we have a new transmit.
21973 		 */
21974 		tcp_seq startseq = tp->snd_max;
21975 
21976 
21977 		if (rsm && (doing_tlp == 0))
21978 			rack->r_ctl.rc_loss_count += rsm->r_end - rsm->r_start;
21979 		if (error)
21980 			/* We don't log or do anything with errors */
21981 			goto nomore;
21982 		if (doing_tlp == 0) {
21983 			if (rsm == NULL) {
21984 				/*
21985 				 * Not a retransmission of some
21986 				 * sort, new data is going out so
21987 				 * clear our TLP count and flag.
21988 				 */
21989 				rack->rc_tlp_in_progress = 0;
21990 				rack->r_ctl.rc_tlp_cnt_out = 0;
21991 			}
21992 		} else {
21993 			/*
21994 			 * We have just sent a TLP, mark that it is true
21995 			 * and make sure our in progress is set so we
21996 			 * continue to check the count.
21997 			 */
21998 			rack->rc_tlp_in_progress = 1;
21999 			rack->r_ctl.rc_tlp_cnt_out++;
22000 		}
22001 		/*
22002 		 * If we are retransmitting we are done, snd_max
22003 		 * does not get updated.
22004 		 */
22005 		if (sack_rxmit)
22006 			goto nomore;
22007 		if ((tp->snd_una == tp->snd_max) && (len > 0)) {
22008 			/*
22009 			 * Update the time we just added data since
22010 			 * nothing was outstanding.
22011 			 */
22012 			rack_log_progress_event(rack, tp, ticks, PROGRESS_START, __LINE__);
22013 			tp->t_acktime = ticks;
22014 		}
22015 		/*
22016 		 * Now for special SYN/FIN handling.
22017 		 */
22018 		if (flags & (TH_SYN | TH_FIN)) {
22019 			if ((flags & TH_SYN) &&
22020 			    ((tp->t_flags & TF_SENTSYN) == 0)) {
22021 				tp->snd_max++;
22022 				tp->t_flags |= TF_SENTSYN;
22023 			}
22024 			if ((flags & TH_FIN) &&
22025 			    ((tp->t_flags & TF_SENTFIN) == 0)) {
22026 				tp->snd_max++;
22027 				tp->t_flags |= TF_SENTFIN;
22028 			}
22029 		}
22030 		tp->snd_max += len;
22031 		if (rack->rc_new_rnd_needed) {
22032 			rack_new_round_starts(tp, rack, tp->snd_max);
22033 		}
22034 		/*
22035 		 * Time this transmission if not a retransmission and
22036 		 * not currently timing anything.
22037 		 * This is only relevant in case of switching back to
22038 		 * the base stack.
22039 		 */
22040 		if (tp->t_rtttime == 0) {
22041 			tp->t_rtttime = ticks;
22042 			tp->t_rtseq = startseq;
22043 			KMOD_TCPSTAT_INC(tcps_segstimed);
22044 		}
22045 		if (len &&
22046 		    ((tp->t_flags & TF_GPUTINPROG) == 0))
22047 			rack_start_gp_measurement(tp, rack, startseq, sb_offset);
22048 		/*
22049 		 * If we are doing FO we need to update the mbuf position and subtract
22050 		 * this happens when the peer sends us duplicate information and
22051 		 * we thus want to send a DSACK.
22052 		 *
22053 		 * XXXRRS: This brings to mind a ?, when we send a DSACK block is TSO
22054 		 * turned off? If not then we are going to echo multiple DSACK blocks
22055 		 * out (with the TSO), which we should not be doing.
22056 		 */
22057 		if (rack->r_fast_output && len) {
22058 			if (rack->r_ctl.fsb.left_to_send > len)
22059 				rack->r_ctl.fsb.left_to_send -= len;
22060 			else
22061 				rack->r_ctl.fsb.left_to_send = 0;
22062 			if (rack->r_ctl.fsb.left_to_send < segsiz)
22063 				rack->r_fast_output = 0;
22064 			if (rack->r_fast_output) {
22065 				rack->r_ctl.fsb.m = sbsndmbuf(sb, (tp->snd_max - tp->snd_una), &rack->r_ctl.fsb.off);
22066 				rack->r_ctl.fsb.o_m_len = rack->r_ctl.fsb.m->m_len;
22067 				rack->r_ctl.fsb.o_t_len = M_TRAILINGROOM(rack->r_ctl.fsb.m);
22068 			}
22069 		}
22070 		if (rack_pcm_blast == 0) {
22071 			if ((orig_len > len) &&
22072 			    (add_flag & RACK_IS_PCM) &&
22073 			    (len < pace_max_seg) &&
22074 			    ((pace_max_seg - len) > segsiz)) {
22075 				/*
22076 				 * We are doing a PCM measurement and we did
22077 				 * not get enough data in the TSO to meet the
22078 				 * burst requirement.
22079 				 */
22080 				uint32_t n_len;
22081 
22082 				n_len = (orig_len - len);
22083 				orig_len -= len;
22084 				pace_max_seg -= len;
22085 				len = n_len;
22086 				sb_offset = tp->snd_max - tp->snd_una;
22087 				/* Re-lock for the next spin */
22088 				SOCK_SENDBUF_LOCK(so);
22089 				goto send;
22090 			}
22091 		} else {
22092 			if ((orig_len > len) &&
22093 			    (add_flag & RACK_IS_PCM) &&
22094 			    ((orig_len - len) > segsiz)) {
22095 				/*
22096 				 * We are doing a PCM measurement and we did
22097 				 * not get enough data in the TSO to meet the
22098 				 * burst requirement.
22099 				 */
22100 				uint32_t n_len;
22101 
22102 				n_len = (orig_len - len);
22103 				orig_len -= len;
22104 				len = n_len;
22105 				sb_offset = tp->snd_max - tp->snd_una;
22106 				/* Re-lock for the next spin */
22107 				SOCK_SENDBUF_LOCK(so);
22108 				goto send;
22109 			}
22110 		}
22111 	}
22112 nomore:
22113 	if (error) {
22114 		rack->r_ctl.rc_agg_delayed = 0;
22115 		rack->r_early = 0;
22116 		rack->r_late = 0;
22117 		rack->r_ctl.rc_agg_early = 0;
22118 		SOCKBUF_UNLOCK_ASSERT(sb);	/* Check gotos. */
22119 		/*
22120 		 * Failures do not advance the seq counter above. For the
22121 		 * case of ENOBUFS we will fall out and retry in 1ms with
22122 		 * the hpts. Everything else will just have to retransmit
22123 		 * with the timer.
22124 		 *
22125 		 * In any case, we do not want to loop around for another
22126 		 * send without a good reason.
22127 		 */
22128 		sendalot = 0;
22129 		switch (error) {
22130 		case EPERM:
22131 		case EACCES:
22132 			tp->t_softerror = error;
22133 #ifdef TCP_ACCOUNTING
22134 			crtsc = get_cyclecount();
22135 			if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
22136 				tp->tcp_cnt_counters[SND_OUT_FAIL]++;
22137 				tp->tcp_proc_time[SND_OUT_FAIL] += (crtsc - ts_val);
22138 			}
22139 			sched_unpin();
22140 #endif
22141 			return (error);
22142 		case ENOBUFS:
22143 			/*
22144 			 * Pace us right away to retry in a some
22145 			 * time
22146 			 */
22147 			if (rack->r_ctl.crte != NULL) {
22148 				tcp_trace_point(rack->rc_tp, TCP_TP_HWENOBUF);
22149 				if (tcp_bblogging_on(rack->rc_tp))
22150 					rack_log_queue_level(tp, rack, len, &tv, cts);
22151 			} else
22152 				tcp_trace_point(rack->rc_tp, TCP_TP_ENOBUF);
22153 			pacing_delay = ((1 + rack->rc_enobuf) * HPTS_USEC_IN_MSEC);
22154 			if (rack->rc_enobuf < 0x7f)
22155 				rack->rc_enobuf++;
22156 			if (pacing_delay < (10 * HPTS_USEC_IN_MSEC))
22157 				pacing_delay = 10 * HPTS_USEC_IN_MSEC;
22158 			if (rack->r_ctl.crte != NULL) {
22159 				counter_u64_add(rack_saw_enobuf_hw, 1);
22160 				tcp_rl_log_enobuf(rack->r_ctl.crte);
22161 			}
22162 			counter_u64_add(rack_saw_enobuf, 1);
22163 			goto enobufs;
22164 		case EMSGSIZE:
22165 			/*
22166 			 * For some reason the interface we used initially
22167 			 * to send segments changed to another or lowered
22168 			 * its MTU. If TSO was active we either got an
22169 			 * interface without TSO capabilits or TSO was
22170 			 * turned off. If we obtained mtu from ip_output()
22171 			 * then update it and try again.
22172 			 */
22173 			if (tso)
22174 				tp->t_flags &= ~TF_TSO;
22175 			if (mtu != 0) {
22176 				int saved_mtu;
22177 
22178 				saved_mtu = tp->t_maxseg;
22179 				tcp_mss_update(tp, -1, mtu, NULL, NULL);
22180 				if (saved_mtu > tp->t_maxseg) {
22181 					goto again;
22182 				}
22183 			}
22184 			pacing_delay = 10 * HPTS_USEC_IN_MSEC;
22185 			rack_start_hpts_timer(rack, tp, cts, pacing_delay, 0, 0);
22186 #ifdef TCP_ACCOUNTING
22187 			crtsc = get_cyclecount();
22188 			if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
22189 				tp->tcp_cnt_counters[SND_OUT_FAIL]++;
22190 				tp->tcp_proc_time[SND_OUT_FAIL] += (crtsc - ts_val);
22191 			}
22192 			sched_unpin();
22193 #endif
22194 			return (error);
22195 		case ENETUNREACH:
22196 			counter_u64_add(rack_saw_enetunreach, 1);
22197 			/* FALLTHROUGH */
22198 		case EHOSTDOWN:
22199 		case EHOSTUNREACH:
22200 		case ENETDOWN:
22201 			if (TCPS_HAVERCVDSYN(tp->t_state)) {
22202 				tp->t_softerror = error;
22203 				error = 0;
22204 			}
22205 			/* FALLTHROUGH */
22206 		default:
22207 			pacing_delay = 10 * HPTS_USEC_IN_MSEC;
22208 			rack_start_hpts_timer(rack, tp, cts, pacing_delay, 0, 0);
22209 #ifdef TCP_ACCOUNTING
22210 			crtsc = get_cyclecount();
22211 			if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
22212 				tp->tcp_cnt_counters[SND_OUT_FAIL]++;
22213 				tp->tcp_proc_time[SND_OUT_FAIL] += (crtsc - ts_val);
22214 			}
22215 			sched_unpin();
22216 #endif
22217 			return (error);
22218 		}
22219 	} else {
22220 		rack->rc_enobuf = 0;
22221 		if (IN_FASTRECOVERY(tp->t_flags) && rsm)
22222 			rack->r_ctl.retran_during_recovery += len;
22223 	}
22224 	KMOD_TCPSTAT_INC(tcps_sndtotal);
22225 
22226 	/*
22227 	 * Data sent (as far as we can tell). If this advertises a larger
22228 	 * window than any other segment, then remember the size of the
22229 	 * advertised window. Any pending ACK has now been sent.
22230 	 */
22231 	if (recwin > 0 && SEQ_GT(tp->rcv_nxt + recwin, tp->rcv_adv))
22232 		tp->rcv_adv = tp->rcv_nxt + recwin;
22233 
22234 	tp->last_ack_sent = tp->rcv_nxt;
22235 	tp->t_flags &= ~(TF_ACKNOW | TF_DELACK);
22236 enobufs:
22237 	if (sendalot) {
22238 		/* Do we need to turn off sendalot? */
22239 		if (pace_max_seg &&
22240 		    (tot_len_this_send >= pace_max_seg)) {
22241 			/* We hit our max. */
22242 			sendalot = 0;
22243 		}
22244 	}
22245 	if ((error == 0) && (flags & TH_FIN))
22246 		tcp_log_end_status(tp, TCP_EI_STATUS_SERVER_FIN);
22247 	if (flags & TH_RST) {
22248 		/*
22249 		 * We don't send again after sending a RST.
22250 		 */
22251 		pacing_delay = 0;
22252 		sendalot = 0;
22253 		if (error == 0)
22254 			tcp_log_end_status(tp, TCP_EI_STATUS_SERVER_RST);
22255 	} else if ((pacing_delay == 0) && (sendalot == 0) && tot_len_this_send) {
22256 		/*
22257 		 * Get our pacing rate, if an error
22258 		 * occurred in sending (ENOBUF) we would
22259 		 * hit the else if with slot preset. Other
22260 		 * errors return.
22261 		 */
22262 		pacing_delay = rack_get_pacing_delay(rack, tp, tot_len_this_send, rsm, segsiz, __LINE__);
22263 	}
22264 	/* We have sent clear the flag */
22265 	rack->r_ent_rec_ns = 0;
22266 	if (rack->r_must_retran) {
22267 		if (rsm) {
22268 			rack->r_ctl.rc_out_at_rto -= (rsm->r_end - rsm->r_start);
22269 			if (SEQ_GEQ(rsm->r_end, rack->r_ctl.rc_snd_max_at_rto)) {
22270 				/*
22271 				 * We have retransmitted all.
22272 				 */
22273 				rack->r_must_retran = 0;
22274 				rack->r_ctl.rc_out_at_rto = 0;
22275 			}
22276 		} else if (SEQ_GEQ(tp->snd_max, rack->r_ctl.rc_snd_max_at_rto)) {
22277 			/*
22278 			 * Sending new data will also kill
22279 			 * the loop.
22280 			 */
22281 			rack->r_must_retran = 0;
22282 			rack->r_ctl.rc_out_at_rto = 0;
22283 		}
22284 	}
22285 	rack->r_ctl.fsb.recwin = recwin;
22286 	if ((tp->t_flags & (TF_WASCRECOVERY|TF_WASFRECOVERY)) &&
22287 	    SEQ_GT(tp->snd_max, rack->r_ctl.rc_snd_max_at_rto)) {
22288 		/*
22289 		 * We hit an RTO and now have past snd_max at the RTO
22290 		 * clear all the WAS flags.
22291 		 */
22292 		tp->t_flags &= ~(TF_WASCRECOVERY|TF_WASFRECOVERY);
22293 	}
22294 	if (pacing_delay) {
22295 		/* set the rack tcb into the slot N */
22296 		if ((error == 0) &&
22297 		    rack_use_rfo &&
22298 		    ((flags & (TH_SYN|TH_FIN)) == 0) &&
22299 		    (rsm == NULL) &&
22300 		    (ipoptlen == 0) &&
22301 		    (doing_tlp == 0) &&
22302 		    rack->r_fsb_inited &&
22303 		    TCPS_HAVEESTABLISHED(tp->t_state) &&
22304 		    ((IN_RECOVERY(tp->t_flags)) == 0) &&
22305 		    (rack->r_must_retran == 0) &&
22306 		    ((tp->t_flags & TF_NEEDFIN) == 0) &&
22307 		    (len > 0) && (orig_len > 0) &&
22308 		    (orig_len > len) &&
22309 		    ((orig_len - len) >= segsiz) &&
22310 		    ((optlen == 0) ||
22311 		     ((optlen == TCPOLEN_TSTAMP_APPA) && (to.to_flags & TOF_TS)))) {
22312 			/* We can send at least one more MSS using our fsb */
22313 			rack_setup_fast_output(tp, rack, sb, len, orig_len,
22314 					       segsiz, pace_max_seg, hw_tls, flags);
22315 		} else
22316 			rack->r_fast_output = 0;
22317 		rack_log_fsb(rack, tp, so, flags,
22318 			     ipoptlen, orig_len, len, error,
22319 			     (rsm == NULL), optlen, __LINE__, 2);
22320 	} else if (sendalot) {
22321 		int ret;
22322 
22323 		sack_rxmit = 0;
22324 		if ((error == 0) &&
22325 		    rack_use_rfo &&
22326 		    ((flags & (TH_SYN|TH_FIN)) == 0) &&
22327 		    (rsm == NULL) &&
22328 		    (doing_tlp == 0) &&
22329 		    (ipoptlen == 0) &&
22330 		    (rack->r_must_retran == 0) &&
22331 		    rack->r_fsb_inited &&
22332 		    TCPS_HAVEESTABLISHED(tp->t_state) &&
22333 		    ((IN_RECOVERY(tp->t_flags)) == 0) &&
22334 		    ((tp->t_flags & TF_NEEDFIN) == 0) &&
22335 		    (len > 0) && (orig_len > 0) &&
22336 		    (orig_len > len) &&
22337 		    ((orig_len - len) >= segsiz) &&
22338 		    ((optlen == 0) ||
22339 		     ((optlen == TCPOLEN_TSTAMP_APPA) && (to.to_flags & TOF_TS)))) {
22340 			/* we can use fast_output for more */
22341 			rack_setup_fast_output(tp, rack, sb, len, orig_len,
22342 					       segsiz, pace_max_seg, hw_tls, flags);
22343 			if (rack->r_fast_output) {
22344 				error = 0;
22345 				ret = rack_fast_output(tp, rack, ts_val, cts, ms_cts, &tv, &tot_len_this_send, &error, __LINE__);
22346 				if (ret >= 0)
22347 					return (ret);
22348 			        else if (error)
22349 					goto nomore;
22350 
22351 			}
22352 		}
22353 		goto again;
22354 	}
22355 skip_all_send:
22356 	/* Assure when we leave that snd_nxt will point to top */
22357 	if (SEQ_GT(tp->snd_max, tp->snd_nxt))
22358 		tp->snd_nxt = tp->snd_max;
22359 	rack_start_hpts_timer(rack, tp, cts, pacing_delay, tot_len_this_send, 0);
22360 #ifdef TCP_ACCOUNTING
22361 	crtsc = get_cyclecount() - ts_val;
22362 	if (tot_len_this_send) {
22363 		if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
22364 			tp->tcp_cnt_counters[SND_OUT_DATA]++;
22365 			tp->tcp_proc_time[SND_OUT_DATA] += crtsc;
22366 			tp->tcp_cnt_counters[CNT_OF_MSS_OUT] += ((tot_len_this_send + segsiz - 1) /segsiz);
22367 		}
22368 	} else {
22369 		if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
22370 			tp->tcp_cnt_counters[SND_OUT_ACK]++;
22371 			tp->tcp_proc_time[SND_OUT_ACK] += crtsc;
22372 		}
22373 	}
22374 	sched_unpin();
22375 #endif
22376 	if (error == ENOBUFS)
22377 		error = 0;
22378 	return (error);
22379 }
22380 
22381 static void
22382 rack_update_seg(struct tcp_rack *rack)
22383 {
22384 	uint32_t orig_val;
22385 
22386 	orig_val = rack->r_ctl.rc_pace_max_segs;
22387 	rack_set_pace_segments(rack->rc_tp, rack, __LINE__, NULL);
22388 	if (orig_val != rack->r_ctl.rc_pace_max_segs)
22389 		rack_log_pacing_delay_calc(rack, 0, 0, orig_val, 0, 0, 15, __LINE__, NULL, 0);
22390 }
22391 
22392 static void
22393 rack_mtu_change(struct tcpcb *tp)
22394 {
22395 	/*
22396 	 * The MSS may have changed
22397 	 */
22398 	struct tcp_rack *rack;
22399 	struct rack_sendmap *rsm;
22400 
22401 	rack = (struct tcp_rack *)tp->t_fb_ptr;
22402 	if (rack->r_ctl.rc_pace_min_segs != ctf_fixed_maxseg(tp)) {
22403 		/*
22404 		 * The MTU has changed we need to resend everything
22405 		 * since all we have sent is lost. We first fix
22406 		 * up the mtu though.
22407 		 */
22408 		rack_set_pace_segments(tp, rack, __LINE__, NULL);
22409 		/* We treat this like a full retransmit timeout without the cwnd adjustment */
22410 		rack_remxt_tmr(tp);
22411 		rack->r_fast_output = 0;
22412 		rack->r_ctl.rc_out_at_rto = ctf_flight_size(tp,
22413 						rack->r_ctl.rc_sacked);
22414 		rack->r_ctl.rc_snd_max_at_rto = tp->snd_max;
22415 		rack->r_must_retran = 1;
22416 		/* Mark all inflight to needing to be rxt'd */
22417 		TAILQ_FOREACH(rsm, &rack->r_ctl.rc_tmap, r_tnext) {
22418 			rsm->r_flags |= (RACK_MUST_RXT|RACK_PMTU_CHG);
22419 		}
22420 	}
22421 	sack_filter_clear(&rack->r_ctl.rack_sf, tp->snd_una);
22422 	/* We don't use snd_nxt to retransmit */
22423 	tp->snd_nxt = tp->snd_max;
22424 }
22425 
22426 static int
22427 rack_set_dgp(struct tcp_rack *rack)
22428 {
22429 	if (rack->dgp_on == 1)
22430 		return(0);
22431 	if ((rack->use_fixed_rate == 1) &&
22432 	    (rack->rc_always_pace == 1)) {
22433 		/*
22434 		 * We are already pacing another
22435 		 * way.
22436 		 */
22437 		return (EBUSY);
22438 	}
22439 	if (rack->rc_always_pace == 1) {
22440 		rack_remove_pacing(rack);
22441 	}
22442 	if (tcp_incr_dgp_pacing_cnt() == 0)
22443 		return (ENOSPC);
22444 	rack->r_ctl.pacing_method |= RACK_DGP_PACING;
22445 	rack->rc_fillcw_apply_discount = 0;
22446 	rack->dgp_on = 1;
22447 	rack->rc_always_pace = 1;
22448 	rack->rc_pace_dnd = 1;
22449 	rack->use_fixed_rate = 0;
22450 	if (rack->gp_ready)
22451 		rack_set_cc_pacing(rack);
22452 	rack->rc_tp->t_flags2 |= TF2_SUPPORTS_MBUFQ;
22453 	rack->rack_attempt_hdwr_pace = 0;
22454 	/* rxt settings */
22455 	rack->full_size_rxt = 1;
22456 	rack->shape_rxt_to_pacing_min  = 0;
22457 	/* cmpack=1 */
22458 	rack->r_use_cmp_ack = 1;
22459 	if (TCPS_HAVEESTABLISHED(rack->rc_tp->t_state) &&
22460 	    rack->r_use_cmp_ack)
22461 		rack->rc_tp->t_flags2 |= TF2_MBUF_ACKCMP;
22462 	/* scwnd=1 */
22463 	rack->rack_enable_scwnd = 1;
22464 	/* dynamic=100 */
22465 	rack->rc_gp_dyn_mul = 1;
22466 	/* gp_inc_ca */
22467 	rack->r_ctl.rack_per_of_gp_ca = 100;
22468 	/* rrr_conf=3 */
22469 	rack->r_rr_config = 3;
22470 	/* npush=2 */
22471 	rack->r_ctl.rc_no_push_at_mrtt = 2;
22472 	/* fillcw=1 */
22473 	rack->rc_pace_to_cwnd = 1;
22474 	rack->rc_pace_fill_if_rttin_range = 0;
22475 	rack->rtt_limit_mul = 0;
22476 	/* noprr=1 */
22477 	rack->rack_no_prr = 1;
22478 	/* lscwnd=1 */
22479 	rack->r_limit_scw = 1;
22480 	/* gp_inc_rec */
22481 	rack->r_ctl.rack_per_of_gp_rec = 90;
22482 	return (0);
22483 }
22484 
22485 static int
22486 rack_set_profile(struct tcp_rack *rack, int prof)
22487 {
22488 	int err = EINVAL;
22489 	if (prof == 1) {
22490 		/*
22491 		 * Profile 1 is "standard" DGP. It ignores
22492 		 * client buffer level.
22493 		 */
22494 		err = rack_set_dgp(rack);
22495 		if (err)
22496 			return (err);
22497 	} else if (prof == 6) {
22498 		err = rack_set_dgp(rack);
22499 		if (err)
22500 			return (err);
22501 		/*
22502 		 * Profile 6 tweaks DGP so that it will apply to
22503 		 * fill-cw the same settings that profile5 does
22504 		 * to replace DGP. It gets then the max(dgp-rate, fillcw(discounted).
22505 		 */
22506 		rack->rc_fillcw_apply_discount = 1;
22507 	} else if (prof == 0) {
22508 		/* This changes things back to the default settings */
22509 		if (rack->rc_always_pace == 1) {
22510 			rack_remove_pacing(rack);
22511 		} else {
22512 			/* Make sure any stray flags are off */
22513 			rack->dgp_on = 0;
22514 			rack->rc_hybrid_mode = 0;
22515 			rack->use_fixed_rate = 0;
22516 		}
22517 		err = 0;
22518 		if (rack_fill_cw_state)
22519 			rack->rc_pace_to_cwnd = 1;
22520 		else
22521 			rack->rc_pace_to_cwnd = 0;
22522 
22523 		if (rack_pace_every_seg && tcp_can_enable_pacing()) {
22524 			rack->r_ctl.pacing_method |= RACK_REG_PACING;
22525 			rack->rc_always_pace = 1;
22526 			if (rack->rack_hibeta)
22527 				rack_set_cc_pacing(rack);
22528 		} else
22529 			rack->rc_always_pace = 0;
22530 		if (rack_dsack_std_based & 0x1) {
22531 			/* Basically this means all rack timers are at least (srtt + 1/4 srtt) */
22532 			rack->rc_rack_tmr_std_based = 1;
22533 		}
22534 		if (rack_dsack_std_based & 0x2) {
22535 			/* Basically this means  rack timers are extended based on dsack by up to (2 * srtt) */
22536 			rack->rc_rack_use_dsack = 1;
22537 		}
22538 		if (rack_use_cmp_acks)
22539 			rack->r_use_cmp_ack = 1;
22540 		else
22541 			rack->r_use_cmp_ack = 0;
22542 		if (rack_disable_prr)
22543 			rack->rack_no_prr = 1;
22544 		else
22545 			rack->rack_no_prr = 0;
22546 		if (rack_gp_no_rec_chg)
22547 			rack->rc_gp_no_rec_chg = 1;
22548 		else
22549 			rack->rc_gp_no_rec_chg = 0;
22550 		if (rack_enable_mqueue_for_nonpaced || rack->r_use_cmp_ack) {
22551 			rack->r_mbuf_queue = 1;
22552 			if (TCPS_HAVEESTABLISHED(rack->rc_tp->t_state))
22553 				rack->rc_tp->t_flags2 |= TF2_MBUF_ACKCMP;
22554 			rack->rc_tp->t_flags2 |= TF2_SUPPORTS_MBUFQ;
22555 		} else {
22556 			rack->r_mbuf_queue = 0;
22557 			rack->rc_tp->t_flags2 &= ~TF2_SUPPORTS_MBUFQ;
22558 		}
22559 		if (rack_enable_shared_cwnd)
22560 			rack->rack_enable_scwnd = 1;
22561 		else
22562 			rack->rack_enable_scwnd = 0;
22563 		if (rack_do_dyn_mul) {
22564 			/* When dynamic adjustment is on CA needs to start at 100% */
22565 			rack->rc_gp_dyn_mul = 1;
22566 			if (rack_do_dyn_mul >= 100)
22567 				rack->r_ctl.rack_per_of_gp_ca = rack_do_dyn_mul;
22568 		} else {
22569 			rack->r_ctl.rack_per_of_gp_ca = rack_per_of_gp_ca;
22570 			rack->rc_gp_dyn_mul = 0;
22571 		}
22572 		rack->r_rr_config = 0;
22573 		rack->r_ctl.rc_no_push_at_mrtt = 0;
22574 		rack->rc_pace_fill_if_rttin_range = 0;
22575 		rack->rtt_limit_mul = 0;
22576 
22577 		if (rack_enable_hw_pacing)
22578 			rack->rack_hdw_pace_ena = 1;
22579 		else
22580 			rack->rack_hdw_pace_ena = 0;
22581 		if (rack_disable_prr)
22582 			rack->rack_no_prr = 1;
22583 		else
22584 			rack->rack_no_prr = 0;
22585 		if (rack_limits_scwnd)
22586 			rack->r_limit_scw  = 1;
22587 		else
22588 			rack->r_limit_scw  = 0;
22589 		rack_init_retransmit_value(rack, rack_rxt_controls);
22590 		err = 0;
22591 	}
22592 	return (err);
22593 }
22594 
22595 static int
22596 rack_add_deferred_option(struct tcp_rack *rack, int sopt_name, uint64_t loptval)
22597 {
22598 	struct deferred_opt_list *dol;
22599 
22600 	dol = malloc(sizeof(struct deferred_opt_list),
22601 		     M_TCPDO, M_NOWAIT|M_ZERO);
22602 	if (dol == NULL) {
22603 		/*
22604 		 * No space yikes -- fail out..
22605 		 */
22606 		return (0);
22607 	}
22608 	dol->optname = sopt_name;
22609 	dol->optval = loptval;
22610 	TAILQ_INSERT_TAIL(&rack->r_ctl.opt_list, dol, next);
22611 	return (1);
22612 }
22613 
22614 static int
22615 process_hybrid_pacing(struct tcp_rack *rack, struct tcp_hybrid_req *hybrid)
22616 {
22617 #ifdef TCP_REQUEST_TRK
22618 	struct tcp_sendfile_track *sft;
22619 	struct timeval tv;
22620 	tcp_seq seq;
22621 	int err;
22622 
22623 	microuptime(&tv);
22624 
22625 	/* Make sure no fixed rate is on */
22626 	rack->use_fixed_rate = 0;
22627 	rack->r_ctl.rc_fixed_pacing_rate_rec = 0;
22628 	rack->r_ctl.rc_fixed_pacing_rate_ca = 0;
22629 	rack->r_ctl.rc_fixed_pacing_rate_ss = 0;
22630 	/* Now allocate or find our entry that will have these settings */
22631 	sft = tcp_req_alloc_req_full(rack->rc_tp, &hybrid->req, tcp_tv_to_lusec(&tv), 0);
22632 	if (sft == NULL) {
22633 		rack->rc_tp->tcp_hybrid_error++;
22634 		/* no space, where would it have gone? */
22635 		seq = rack->rc_tp->snd_una + rack->rc_tp->t_inpcb.inp_socket->so_snd.sb_ccc;
22636 		rack_log_hybrid(rack, seq, NULL, HYBRID_LOG_NO_ROOM, __LINE__, 0);
22637 		return (ENOSPC);
22638 	}
22639 	/* mask our internal flags */
22640 	hybrid->hybrid_flags &= TCP_HYBRID_PACING_USER_MASK;
22641 	/* The seq will be snd_una + everything in the buffer */
22642 	seq = sft->start_seq;
22643 	if ((hybrid->hybrid_flags & TCP_HYBRID_PACING_ENABLE) == 0) {
22644 		/* Disabling hybrid pacing */
22645 		if (rack->rc_hybrid_mode) {
22646 			rack_set_profile(rack, 0);
22647 			rack->rc_tp->tcp_hybrid_stop++;
22648 		}
22649 		rack_log_hybrid(rack, seq, sft, HYBRID_LOG_TURNED_OFF, __LINE__, 0);
22650 		return (0);
22651 	}
22652 	if (rack->dgp_on == 0) {
22653 		/*
22654 		 * If we have not yet turned DGP on, do so
22655 		 * now setting pure DGP mode, no buffer level
22656 		 * response.
22657 		 */
22658 		if ((err = rack_set_profile(rack, 1)) != 0){
22659 			/* Failed to turn pacing on */
22660 			rack->rc_tp->tcp_hybrid_error++;
22661 			rack_log_hybrid(rack, seq, sft, HYBRID_LOG_NO_PACING, __LINE__, 0);
22662 			return (err);
22663 		}
22664 	}
22665 	/*
22666 	 * Now we must switch to hybrid mode as well which also
22667 	 * means moving to regular pacing.
22668 	 */
22669 	if (rack->rc_hybrid_mode == 0) {
22670 		/* First time */
22671 		if (tcp_can_enable_pacing()) {
22672 			rack->r_ctl.pacing_method |= RACK_REG_PACING;
22673 			rack->rc_hybrid_mode = 1;
22674 		} else {
22675 			return (ENOSPC);
22676 		}
22677 		if (rack->r_ctl.pacing_method & RACK_DGP_PACING) {
22678 			/*
22679 			 * This should be true.
22680 			 */
22681 			tcp_dec_dgp_pacing_cnt();
22682 			rack->r_ctl.pacing_method &= ~RACK_DGP_PACING;
22683 		}
22684 	}
22685 	/* Now set in our flags */
22686 	sft->hybrid_flags = hybrid->hybrid_flags | TCP_HYBRID_PACING_WASSET;
22687 	if (hybrid->hybrid_flags & TCP_HYBRID_PACING_CSPR)
22688 		sft->cspr = hybrid->cspr;
22689 	else
22690 		sft->cspr = 0;
22691 	if (hybrid->hybrid_flags & TCP_HYBRID_PACING_H_MS)
22692 		sft->hint_maxseg = hybrid->hint_maxseg;
22693 	else
22694 		sft->hint_maxseg = 0;
22695 	rack->rc_tp->tcp_hybrid_start++;
22696 	rack_log_hybrid(rack, seq, sft, HYBRID_LOG_RULES_SET, __LINE__,0);
22697 	return (0);
22698 #else
22699 	return (ENOTSUP);
22700 #endif
22701 }
22702 
22703 static int
22704 rack_stack_information(struct tcpcb *tp, struct stack_specific_info *si)
22705 {
22706 	/* We pulled a SSI info log out what was there */
22707 	si->bytes_transmitted = tp->t_sndbytes;
22708 	si->bytes_retransmitted = tp->t_snd_rxt_bytes;
22709 	return (0);
22710 }
22711 
22712 static int
22713 rack_process_option(struct tcpcb *tp, struct tcp_rack *rack, int sopt_name,
22714 		    uint32_t optval, uint64_t loptval, struct tcp_hybrid_req *hybrid)
22715 
22716 {
22717 	struct epoch_tracker et;
22718 	struct sockopt sopt;
22719 	struct cc_newreno_opts opt;
22720 	uint64_t val;
22721 	int error = 0;
22722 	uint16_t ca, ss;
22723 
22724 	switch (sopt_name) {
22725 	case TCP_RACK_SET_RXT_OPTIONS:
22726 		if (optval <= 2) {
22727 			rack_init_retransmit_value(rack, optval);
22728 		} else {
22729 			/*
22730 			 * You must send in 0, 1 or 2 all else is
22731 			 * invalid.
22732 			 */
22733 			error = EINVAL;
22734 		}
22735 		break;
22736 	case TCP_RACK_DSACK_OPT:
22737 		RACK_OPTS_INC(tcp_rack_dsack_opt);
22738 		if (optval & 0x1) {
22739 			rack->rc_rack_tmr_std_based = 1;
22740 		} else {
22741 			rack->rc_rack_tmr_std_based = 0;
22742 		}
22743 		if (optval & 0x2) {
22744 			rack->rc_rack_use_dsack = 1;
22745 		} else {
22746 			rack->rc_rack_use_dsack = 0;
22747 		}
22748 		rack_log_dsack_event(rack, 5, __LINE__, 0, 0);
22749 		break;
22750 	case TCP_RACK_PACING_DIVISOR:
22751 		RACK_OPTS_INC(tcp_rack_pacing_divisor);
22752 		if (optval == 0) {
22753 			rack->r_ctl.pace_len_divisor = rack_default_pacing_divisor;
22754 		} else {
22755 			if (optval < RL_MIN_DIVISOR)
22756 				rack->r_ctl.pace_len_divisor = RL_MIN_DIVISOR;
22757 			else
22758 				rack->r_ctl.pace_len_divisor = optval;
22759 		}
22760 		break;
22761 	case TCP_RACK_HI_BETA:
22762 		RACK_OPTS_INC(tcp_rack_hi_beta);
22763 		if (optval > 0) {
22764 			rack->rack_hibeta = 1;
22765 			if ((optval >= 50) &&
22766 			    (optval <= 100)) {
22767 				/*
22768 				 * User wants to set a custom beta.
22769 				 */
22770 				rack->r_ctl.saved_hibeta = optval;
22771 				if (rack->rc_pacing_cc_set)
22772 					rack_undo_cc_pacing(rack);
22773 				rack->r_ctl.rc_saved_beta = optval;
22774 			}
22775 			if (rack->rc_pacing_cc_set == 0)
22776 				rack_set_cc_pacing(rack);
22777 		} else {
22778 			rack->rack_hibeta = 0;
22779 			if (rack->rc_pacing_cc_set)
22780 				rack_undo_cc_pacing(rack);
22781 		}
22782 		break;
22783 	case TCP_RACK_PACING_BETA:
22784 		error = EINVAL;
22785 		break;
22786 	case TCP_RACK_TIMER_SLOP:
22787 		RACK_OPTS_INC(tcp_rack_timer_slop);
22788 		rack->r_ctl.timer_slop = optval;
22789 		if (rack->rc_tp->t_srtt) {
22790 			/*
22791 			 * If we have an SRTT lets update t_rxtcur
22792 			 * to have the new slop.
22793 			 */
22794 			RACK_TCPT_RANGESET(tp->t_rxtcur, RACK_REXMTVAL(tp),
22795 					   rack_rto_min, rack_rto_max,
22796 					   rack->r_ctl.timer_slop);
22797 		}
22798 		break;
22799 	case TCP_RACK_PACING_BETA_ECN:
22800 		RACK_OPTS_INC(tcp_rack_beta_ecn);
22801 		if (strcmp(tp->t_cc->name, CCALGONAME_NEWRENO) != 0) {
22802 			/* This only works for newreno. */
22803 			error = EINVAL;
22804 			break;
22805 		}
22806 		if (rack->rc_pacing_cc_set) {
22807 			/*
22808 			 * Set them into the real CC module
22809 			 * whats in the rack pcb is the old values
22810 			 * to be used on restoral/
22811 			 */
22812 			sopt.sopt_dir = SOPT_SET;
22813 			opt.name = CC_NEWRENO_BETA_ECN;
22814 			opt.val = optval;
22815 			if (CC_ALGO(tp)->ctl_output != NULL)
22816 				error = CC_ALGO(tp)->ctl_output(&tp->t_ccv, &sopt, &opt);
22817 			else
22818 				error = ENOENT;
22819 		} else {
22820 			/*
22821 			 * Not pacing yet so set it into our local
22822 			 * rack pcb storage.
22823 			 */
22824 			rack->r_ctl.rc_saved_beta_ecn = optval;
22825 		}
22826 		break;
22827 	case TCP_DEFER_OPTIONS:
22828 		RACK_OPTS_INC(tcp_defer_opt);
22829 		if (optval) {
22830 			if (rack->gp_ready) {
22831 				/* Too late */
22832 				error = EINVAL;
22833 				break;
22834 			}
22835 			rack->defer_options = 1;
22836 		} else
22837 			rack->defer_options = 0;
22838 		break;
22839 	case TCP_RACK_MEASURE_CNT:
22840 		RACK_OPTS_INC(tcp_rack_measure_cnt);
22841 		if (optval && (optval <= 0xff)) {
22842 			rack->r_ctl.req_measurements = optval;
22843 		} else
22844 			error = EINVAL;
22845 		break;
22846 	case TCP_REC_ABC_VAL:
22847 		RACK_OPTS_INC(tcp_rec_abc_val);
22848 		if (optval > 0)
22849 			rack->r_use_labc_for_rec = 1;
22850 		else
22851 			rack->r_use_labc_for_rec = 0;
22852 		break;
22853 	case TCP_RACK_ABC_VAL:
22854 		RACK_OPTS_INC(tcp_rack_abc_val);
22855 		if ((optval > 0) && (optval < 255))
22856 			rack->rc_labc = optval;
22857 		else
22858 			error = EINVAL;
22859 		break;
22860 	case TCP_HDWR_UP_ONLY:
22861 		RACK_OPTS_INC(tcp_pacing_up_only);
22862 		if (optval)
22863 			rack->r_up_only = 1;
22864 		else
22865 			rack->r_up_only = 0;
22866 		break;
22867 	case TCP_FILLCW_RATE_CAP:		/*  URL:fillcw_cap */
22868 		RACK_OPTS_INC(tcp_fillcw_rate_cap);
22869 		rack->r_ctl.fillcw_cap = loptval;
22870 		break;
22871 	case TCP_PACING_RATE_CAP:
22872 		RACK_OPTS_INC(tcp_pacing_rate_cap);
22873 		if ((rack->dgp_on == 1) &&
22874 		    (rack->r_ctl.pacing_method & RACK_DGP_PACING)) {
22875 			/*
22876 			 * If we are doing DGP we need to switch
22877 			 * to using the pacing limit.
22878 			 */
22879 			if (tcp_can_enable_pacing() == 0) {
22880 				error = ENOSPC;
22881 				break;
22882 			}
22883 			/*
22884 			 * Now change up the flags and counts to be correct.
22885 			 */
22886 			rack->r_ctl.pacing_method |= RACK_REG_PACING;
22887 			tcp_dec_dgp_pacing_cnt();
22888 			rack->r_ctl.pacing_method &= ~RACK_DGP_PACING;
22889 		}
22890 		rack->r_ctl.bw_rate_cap = loptval;
22891 		break;
22892 	case TCP_HYBRID_PACING:
22893 		if (hybrid == NULL) {
22894 			error = EINVAL;
22895 			break;
22896 		}
22897 		if (rack->r_ctl.side_chan_dis_mask & HYBRID_DIS_MASK) {
22898 			error = EPERM;
22899 			break;
22900 		}
22901 		error = process_hybrid_pacing(rack, hybrid);
22902 		break;
22903 	case TCP_SIDECHAN_DIS:			/*  URL:scodm */
22904 		if (optval)
22905 			rack->r_ctl.side_chan_dis_mask = optval;
22906 		else
22907 			rack->r_ctl.side_chan_dis_mask = 0;
22908 		break;
22909 	case TCP_RACK_PROFILE:
22910 		RACK_OPTS_INC(tcp_profile);
22911 		error = rack_set_profile(rack, optval);
22912 		break;
22913 	case TCP_USE_CMP_ACKS:
22914 		RACK_OPTS_INC(tcp_use_cmp_acks);
22915 		if ((optval == 0) && (tp->t_flags2 & TF2_MBUF_ACKCMP)) {
22916 			/* You can't turn it off once its on! */
22917 			error = EINVAL;
22918 		} else if ((optval == 1) && (rack->r_use_cmp_ack == 0)) {
22919 			rack->r_use_cmp_ack = 1;
22920 			rack->r_mbuf_queue = 1;
22921 			tp->t_flags2 |= TF2_SUPPORTS_MBUFQ;
22922 		}
22923 		if (rack->r_use_cmp_ack && TCPS_HAVEESTABLISHED(tp->t_state))
22924 			tp->t_flags2 |= TF2_MBUF_ACKCMP;
22925 		break;
22926 	case TCP_SHARED_CWND_TIME_LIMIT:
22927 		RACK_OPTS_INC(tcp_lscwnd);
22928 		if (optval)
22929 			rack->r_limit_scw = 1;
22930 		else
22931 			rack->r_limit_scw = 0;
22932 		break;
22933 	case TCP_RACK_DGP_IN_REC:
22934 		error = EINVAL;
22935 		break;
22936  	case TCP_RACK_PACE_TO_FILL:
22937 		RACK_OPTS_INC(tcp_fillcw);
22938 		if (optval == 0)
22939 			rack->rc_pace_to_cwnd = 0;
22940 		else {
22941 			rack->rc_pace_to_cwnd = 1;
22942 		}
22943 		if ((optval >= rack_gp_rtt_maxmul) &&
22944 		    rack_gp_rtt_maxmul &&
22945 		    (optval < 0xf)) {
22946 			rack->rc_pace_fill_if_rttin_range = 1;
22947 			rack->rtt_limit_mul = optval;
22948 		} else {
22949 			rack->rc_pace_fill_if_rttin_range = 0;
22950 			rack->rtt_limit_mul = 0;
22951 		}
22952 		break;
22953 	case TCP_RACK_NO_PUSH_AT_MAX:
22954 		RACK_OPTS_INC(tcp_npush);
22955 		if (optval == 0)
22956 			rack->r_ctl.rc_no_push_at_mrtt = 0;
22957 		else if (optval < 0xff)
22958 			rack->r_ctl.rc_no_push_at_mrtt = optval;
22959 		else
22960 			error = EINVAL;
22961 		break;
22962 	case TCP_SHARED_CWND_ENABLE:
22963 		RACK_OPTS_INC(tcp_rack_scwnd);
22964 		if (optval == 0)
22965 			rack->rack_enable_scwnd = 0;
22966 		else
22967 			rack->rack_enable_scwnd = 1;
22968 		break;
22969 	case TCP_RACK_MBUF_QUEUE:
22970 		/* Now do we use the LRO mbuf-queue feature */
22971 		RACK_OPTS_INC(tcp_rack_mbufq);
22972 		if (optval || rack->r_use_cmp_ack)
22973 			rack->r_mbuf_queue = 1;
22974 		else
22975 			rack->r_mbuf_queue = 0;
22976 		if  (rack->r_mbuf_queue || rack->rc_always_pace || rack->r_use_cmp_ack)
22977 			tp->t_flags2 |= TF2_SUPPORTS_MBUFQ;
22978 		else
22979 			tp->t_flags2 &= ~TF2_SUPPORTS_MBUFQ;
22980 		break;
22981 	case TCP_RACK_NONRXT_CFG_RATE:
22982 		RACK_OPTS_INC(tcp_rack_cfg_rate);
22983 		if (optval == 0)
22984 			rack->rack_rec_nonrxt_use_cr = 0;
22985 		else
22986 			rack->rack_rec_nonrxt_use_cr = 1;
22987 		break;
22988 	case TCP_NO_PRR:
22989 		RACK_OPTS_INC(tcp_rack_noprr);
22990 		if (optval == 0)
22991 			rack->rack_no_prr = 0;
22992 		else if (optval == 1)
22993 			rack->rack_no_prr = 1;
22994 		else if (optval == 2)
22995 			rack->no_prr_addback = 1;
22996 		else
22997 			error = EINVAL;
22998 		break;
22999 	case RACK_CSPR_IS_FCC:			/*  URL:csprisfcc */
23000 		if (optval > 0)
23001 			rack->cspr_is_fcc = 1;
23002 		else
23003 			rack->cspr_is_fcc = 0;
23004 		break;
23005 	case TCP_TIMELY_DYN_ADJ:
23006 		RACK_OPTS_INC(tcp_timely_dyn);
23007 		if (optval == 0)
23008 			rack->rc_gp_dyn_mul = 0;
23009 		else {
23010 			rack->rc_gp_dyn_mul = 1;
23011 			if (optval >= 100) {
23012 				/*
23013 				 * If the user sets something 100 or more
23014 				 * its the gp_ca value.
23015 				 */
23016 				rack->r_ctl.rack_per_of_gp_ca  = optval;
23017 			}
23018 		}
23019 		break;
23020 	case TCP_RACK_DO_DETECTION:
23021 		error = EINVAL;
23022 		break;
23023 	case TCP_RACK_TLP_USE:
23024 		if ((optval < TLP_USE_ID) || (optval > TLP_USE_TWO_TWO)) {
23025 			error = EINVAL;
23026 			break;
23027 		}
23028 		RACK_OPTS_INC(tcp_tlp_use);
23029 		rack->rack_tlp_threshold_use = optval;
23030 		break;
23031 	case TCP_RACK_TLP_REDUCE:
23032 		/* RACK TLP cwnd reduction (bool) */
23033 		RACK_OPTS_INC(tcp_rack_tlp_reduce);
23034 		rack->r_ctl.rc_tlp_cwnd_reduce = optval;
23035 		break;
23036 		/*  Pacing related ones */
23037 	case TCP_RACK_PACE_ALWAYS:
23038 		/*
23039 		 * zero is old rack method, 1 is new
23040 		 * method using a pacing rate.
23041 		 */
23042 		RACK_OPTS_INC(tcp_rack_pace_always);
23043 		if (rack->r_ctl.side_chan_dis_mask & CCSP_DIS_MASK) {
23044 			error = EPERM;
23045 			break;
23046 		}
23047 		if (optval > 0) {
23048 			if (rack->rc_always_pace) {
23049 				error = EALREADY;
23050 				break;
23051 			} else if (tcp_can_enable_pacing()) {
23052 				rack->r_ctl.pacing_method |= RACK_REG_PACING;
23053 				rack->rc_always_pace = 1;
23054 				if (rack->rack_hibeta)
23055 					rack_set_cc_pacing(rack);
23056 			}
23057 			else {
23058 				error = ENOSPC;
23059 				break;
23060 			}
23061 		} else {
23062 			if (rack->rc_always_pace == 1) {
23063 				rack_remove_pacing(rack);
23064 			}
23065 		}
23066 		if  (rack->r_mbuf_queue || rack->rc_always_pace || rack->r_use_cmp_ack)
23067 			tp->t_flags2 |= TF2_SUPPORTS_MBUFQ;
23068 		else
23069 			tp->t_flags2 &= ~TF2_SUPPORTS_MBUFQ;
23070 		/* A rate may be set irate or other, if so set seg size */
23071 		rack_update_seg(rack);
23072 		break;
23073 	case TCP_BBR_RACK_INIT_RATE:
23074 		RACK_OPTS_INC(tcp_initial_rate);
23075 		val = optval;
23076 		/* Change from kbits per second to bytes per second */
23077 		val *= 1000;
23078 		val /= 8;
23079 		rack->r_ctl.init_rate = val;
23080 		if (rack->rc_always_pace)
23081 			rack_update_seg(rack);
23082 		break;
23083 	case TCP_BBR_IWINTSO:
23084 		error = EINVAL;
23085 		break;
23086 	case TCP_RACK_FORCE_MSEG:
23087 		RACK_OPTS_INC(tcp_rack_force_max_seg);
23088 		if (optval)
23089 			rack->rc_force_max_seg = 1;
23090 		else
23091 			rack->rc_force_max_seg = 0;
23092 		break;
23093 	case TCP_RACK_PACE_MIN_SEG:
23094 		RACK_OPTS_INC(tcp_rack_min_seg);
23095 		rack->r_ctl.rc_user_set_min_segs = (0x0000ffff & optval);
23096 		rack_set_pace_segments(tp, rack, __LINE__, NULL);
23097 		break;
23098 	case TCP_RACK_PACE_MAX_SEG:
23099 		/* Max segments size in a pace in bytes */
23100 		RACK_OPTS_INC(tcp_rack_max_seg);
23101 		if ((rack->dgp_on == 1) &&
23102 		    (rack->r_ctl.pacing_method & RACK_DGP_PACING)) {
23103 			/*
23104 			 * If we set a max-seg and are doing DGP then
23105 			 * we now fall under the pacing limits not the
23106 			 * DGP ones.
23107 			 */
23108 			if (tcp_can_enable_pacing() == 0) {
23109 				error = ENOSPC;
23110 				break;
23111 			}
23112 			/*
23113 			 * Now change up the flags and counts to be correct.
23114 			 */
23115 			rack->r_ctl.pacing_method |= RACK_REG_PACING;
23116 			tcp_dec_dgp_pacing_cnt();
23117 			rack->r_ctl.pacing_method &= ~RACK_DGP_PACING;
23118 		}
23119 		if (optval <= MAX_USER_SET_SEG)
23120 			rack->rc_user_set_max_segs = optval;
23121 		else
23122 			rack->rc_user_set_max_segs = MAX_USER_SET_SEG;
23123 		rack_set_pace_segments(tp, rack, __LINE__, NULL);
23124 		break;
23125 	case TCP_RACK_PACE_RATE_REC:
23126 		/* Set the fixed pacing rate in Bytes per second ca */
23127 		RACK_OPTS_INC(tcp_rack_pace_rate_rec);
23128 		if (rack->r_ctl.side_chan_dis_mask & CCSP_DIS_MASK) {
23129 			error = EPERM;
23130 			break;
23131 		}
23132 		if (rack->dgp_on) {
23133 			/*
23134 			 * We are already pacing another
23135 			 * way.
23136 			 */
23137 			error = EBUSY;
23138 			break;
23139 		}
23140 		rack->r_ctl.rc_fixed_pacing_rate_rec = optval;
23141 		if (rack->r_ctl.rc_fixed_pacing_rate_ca == 0)
23142 			rack->r_ctl.rc_fixed_pacing_rate_ca = optval;
23143 		if (rack->r_ctl.rc_fixed_pacing_rate_ss == 0)
23144 			rack->r_ctl.rc_fixed_pacing_rate_ss = optval;
23145 		rack->use_fixed_rate = 1;
23146 		if (rack->rack_hibeta)
23147 			rack_set_cc_pacing(rack);
23148 		rack_log_pacing_delay_calc(rack,
23149 					   rack->r_ctl.rc_fixed_pacing_rate_ss,
23150 					   rack->r_ctl.rc_fixed_pacing_rate_ca,
23151 					   rack->r_ctl.rc_fixed_pacing_rate_rec, 0, 0, 8,
23152 					   __LINE__, NULL,0);
23153 		break;
23154 
23155 	case TCP_RACK_PACE_RATE_SS:
23156 		/* Set the fixed pacing rate in Bytes per second ca */
23157 		RACK_OPTS_INC(tcp_rack_pace_rate_ss);
23158 		if (rack->r_ctl.side_chan_dis_mask & CCSP_DIS_MASK) {
23159 			error = EPERM;
23160 			break;
23161 		}
23162 		if (rack->dgp_on) {
23163 			/*
23164 			 * We are already pacing another
23165 			 * way.
23166 			 */
23167 			error = EBUSY;
23168 			break;
23169 		}
23170 		rack->r_ctl.rc_fixed_pacing_rate_ss = optval;
23171 		if (rack->r_ctl.rc_fixed_pacing_rate_ca == 0)
23172 			rack->r_ctl.rc_fixed_pacing_rate_ca = optval;
23173 		if (rack->r_ctl.rc_fixed_pacing_rate_rec == 0)
23174 			rack->r_ctl.rc_fixed_pacing_rate_rec = optval;
23175 		rack->use_fixed_rate = 1;
23176 		if (rack->rack_hibeta)
23177 			rack_set_cc_pacing(rack);
23178 		rack_log_pacing_delay_calc(rack,
23179 					   rack->r_ctl.rc_fixed_pacing_rate_ss,
23180 					   rack->r_ctl.rc_fixed_pacing_rate_ca,
23181 					   rack->r_ctl.rc_fixed_pacing_rate_rec, 0, 0, 8,
23182 					   __LINE__, NULL, 0);
23183 		break;
23184 
23185 	case TCP_RACK_PACE_RATE_CA:
23186 		/* Set the fixed pacing rate in Bytes per second ca */
23187 		RACK_OPTS_INC(tcp_rack_pace_rate_ca);
23188 		if (rack->r_ctl.side_chan_dis_mask & CCSP_DIS_MASK) {
23189 			error = EPERM;
23190 			break;
23191 		}
23192 		if (rack->dgp_on) {
23193 			/*
23194 			 * We are already pacing another
23195 			 * way.
23196 			 */
23197 			error = EBUSY;
23198 			break;
23199 		}
23200 		rack->r_ctl.rc_fixed_pacing_rate_ca = optval;
23201 		if (rack->r_ctl.rc_fixed_pacing_rate_ss == 0)
23202 			rack->r_ctl.rc_fixed_pacing_rate_ss = optval;
23203 		if (rack->r_ctl.rc_fixed_pacing_rate_rec == 0)
23204 			rack->r_ctl.rc_fixed_pacing_rate_rec = optval;
23205 		rack->use_fixed_rate = 1;
23206 		if (rack->rack_hibeta)
23207 			rack_set_cc_pacing(rack);
23208 		rack_log_pacing_delay_calc(rack,
23209 					   rack->r_ctl.rc_fixed_pacing_rate_ss,
23210 					   rack->r_ctl.rc_fixed_pacing_rate_ca,
23211 					   rack->r_ctl.rc_fixed_pacing_rate_rec, 0, 0, 8,
23212 					   __LINE__, NULL, 0);
23213 		break;
23214 	case TCP_RACK_GP_INCREASE_REC:
23215 		RACK_OPTS_INC(tcp_gp_inc_rec);
23216 		rack->r_ctl.rack_per_of_gp_rec = optval;
23217 		rack_log_pacing_delay_calc(rack,
23218 					   rack->r_ctl.rack_per_of_gp_ss,
23219 					   rack->r_ctl.rack_per_of_gp_ca,
23220 					   rack->r_ctl.rack_per_of_gp_rec, 0, 0, 1,
23221 					   __LINE__, NULL, 0);
23222 		break;
23223 	case TCP_RACK_GP_INCREASE_CA:
23224 		RACK_OPTS_INC(tcp_gp_inc_ca);
23225 		ca = optval;
23226 		if (ca < 100) {
23227 			/*
23228 			 * We don't allow any reduction
23229 			 * over the GP b/w.
23230 			 */
23231 			error = EINVAL;
23232 			break;
23233 		}
23234 		rack->r_ctl.rack_per_of_gp_ca = ca;
23235 		rack_log_pacing_delay_calc(rack,
23236 					   rack->r_ctl.rack_per_of_gp_ss,
23237 					   rack->r_ctl.rack_per_of_gp_ca,
23238 					   rack->r_ctl.rack_per_of_gp_rec, 0, 0, 1,
23239 					   __LINE__, NULL, 0);
23240 		break;
23241 	case TCP_RACK_GP_INCREASE_SS:
23242 		RACK_OPTS_INC(tcp_gp_inc_ss);
23243 		ss = optval;
23244 		if (ss < 100) {
23245 			/*
23246 			 * We don't allow any reduction
23247 			 * over the GP b/w.
23248 			 */
23249 			error = EINVAL;
23250 			break;
23251 		}
23252 		rack->r_ctl.rack_per_of_gp_ss = ss;
23253 		rack_log_pacing_delay_calc(rack,
23254 					   rack->r_ctl.rack_per_of_gp_ss,
23255 					   rack->r_ctl.rack_per_of_gp_ca,
23256 					   rack->r_ctl.rack_per_of_gp_rec, 0, 0, 1,
23257 					   __LINE__, NULL, 0);
23258 		break;
23259 	case TCP_RACK_RR_CONF:
23260 		RACK_OPTS_INC(tcp_rack_rrr_no_conf_rate);
23261 		if (optval && optval <= 3)
23262 			rack->r_rr_config = optval;
23263 		else
23264 			rack->r_rr_config = 0;
23265 		break;
23266 	case TCP_PACING_DND:			/*  URL:dnd */
23267 		if (optval > 0)
23268 			rack->rc_pace_dnd = 1;
23269 		else
23270 			rack->rc_pace_dnd = 0;
23271 		break;
23272 	case TCP_HDWR_RATE_CAP:
23273 		RACK_OPTS_INC(tcp_hdwr_rate_cap);
23274 		if (optval) {
23275 			if (rack->r_rack_hw_rate_caps == 0)
23276 				rack->r_rack_hw_rate_caps = 1;
23277 			else
23278 				error = EALREADY;
23279 		} else {
23280 			rack->r_rack_hw_rate_caps = 0;
23281 		}
23282 		break;
23283 	case TCP_DGP_UPPER_BOUNDS:
23284 	{
23285 		uint8_t val;
23286 		val = optval & 0x0000ff;
23287 		rack->r_ctl.rack_per_upper_bound_ca = val;
23288 		val = (optval >> 16) & 0x0000ff;
23289 		rack->r_ctl.rack_per_upper_bound_ss = val;
23290 		break;
23291 	}
23292 	case TCP_SS_EEXIT:			/*  URL:eexit */
23293 		if (optval > 0) {
23294 			rack->r_ctl.gp_rnd_thresh =  optval & 0x0ff;
23295 			if (optval & 0x10000) {
23296 				rack->r_ctl.gate_to_fs = 1;
23297 			} else {
23298 				rack->r_ctl.gate_to_fs = 0;
23299 			}
23300 			if (optval & 0x20000) {
23301 				rack->r_ctl.use_gp_not_last = 1;
23302 			} else {
23303 				rack->r_ctl.use_gp_not_last = 0;
23304 			}
23305 			if (optval & 0xfffc0000) {
23306 				uint32_t v;
23307 
23308 				v = (optval >> 18) & 0x00003fff;
23309 				if (v >= 1000)
23310 					rack->r_ctl.gp_gain_req = v;
23311 			}
23312 		} else {
23313 			/* We do not do ss early exit at all */
23314 			rack->rc_initial_ss_comp = 1;
23315 			rack->r_ctl.gp_rnd_thresh = 0;
23316 		}
23317 		break;
23318 	case TCP_RACK_SPLIT_LIMIT:
23319 		RACK_OPTS_INC(tcp_split_limit);
23320 		rack->r_ctl.rc_split_limit = optval;
23321 		break;
23322 	case TCP_BBR_HDWR_PACE:
23323 		RACK_OPTS_INC(tcp_hdwr_pacing);
23324 		if (optval){
23325 			if (rack->rack_hdrw_pacing == 0) {
23326 				rack->rack_hdw_pace_ena = 1;
23327 				rack->rack_attempt_hdwr_pace = 0;
23328 			} else
23329 				error = EALREADY;
23330 		} else {
23331 			rack->rack_hdw_pace_ena = 0;
23332 #ifdef RATELIMIT
23333 			if (rack->r_ctl.crte != NULL) {
23334 				rack->rack_hdrw_pacing = 0;
23335 				rack->rack_attempt_hdwr_pace = 0;
23336 				tcp_rel_pacing_rate(rack->r_ctl.crte, tp);
23337 				rack->r_ctl.crte = NULL;
23338 			}
23339 #endif
23340 		}
23341 		break;
23342 		/*  End Pacing related ones */
23343 	case TCP_RACK_PRR_SENDALOT:
23344 		/* Allow PRR to send more than one seg */
23345 		RACK_OPTS_INC(tcp_rack_prr_sendalot);
23346 		rack->r_ctl.rc_prr_sendalot = optval;
23347 		break;
23348 	case TCP_RACK_MIN_TO:
23349 		/* Minimum time between rack t-o's in ms */
23350 		RACK_OPTS_INC(tcp_rack_min_to);
23351 		rack->r_ctl.rc_min_to = optval;
23352 		break;
23353 	case TCP_RACK_EARLY_SEG:
23354 		/* If early recovery max segments */
23355 		RACK_OPTS_INC(tcp_rack_early_seg);
23356 		rack->r_ctl.rc_early_recovery_segs = optval;
23357 		break;
23358 	case TCP_RACK_ENABLE_HYSTART:
23359 	{
23360 		if (optval) {
23361 			tp->t_ccv.flags |= CCF_HYSTART_ALLOWED;
23362 			if (rack_do_hystart > RACK_HYSTART_ON)
23363 				tp->t_ccv.flags |= CCF_HYSTART_CAN_SH_CWND;
23364 			if (rack_do_hystart > RACK_HYSTART_ON_W_SC)
23365 				tp->t_ccv.flags |= CCF_HYSTART_CONS_SSTH;
23366 		} else {
23367 			tp->t_ccv.flags &= ~(CCF_HYSTART_ALLOWED|CCF_HYSTART_CAN_SH_CWND|CCF_HYSTART_CONS_SSTH);
23368 		}
23369 	}
23370 	break;
23371 	case TCP_RACK_REORD_THRESH:
23372 		/* RACK reorder threshold (shift amount) */
23373 		RACK_OPTS_INC(tcp_rack_reord_thresh);
23374 		if ((optval > 0) && (optval < 31))
23375 			rack->r_ctl.rc_reorder_shift = optval;
23376 		else
23377 			error = EINVAL;
23378 		break;
23379 	case TCP_RACK_REORD_FADE:
23380 		/* Does reordering fade after ms time */
23381 		RACK_OPTS_INC(tcp_rack_reord_fade);
23382 		rack->r_ctl.rc_reorder_fade = optval;
23383 		break;
23384 	case TCP_RACK_TLP_THRESH:
23385 		/* RACK TLP theshold i.e. srtt+(srtt/N) */
23386 		RACK_OPTS_INC(tcp_rack_tlp_thresh);
23387 		if (optval)
23388 			rack->r_ctl.rc_tlp_threshold = optval;
23389 		else
23390 			error = EINVAL;
23391 		break;
23392 	case TCP_BBR_USE_RACK_RR:
23393 		RACK_OPTS_INC(tcp_rack_rr);
23394 		if (optval)
23395 			rack->use_rack_rr = 1;
23396 		else
23397 			rack->use_rack_rr = 0;
23398 		break;
23399 	case TCP_RACK_PKT_DELAY:
23400 		/* RACK added ms i.e. rack-rtt + reord + N */
23401 		RACK_OPTS_INC(tcp_rack_pkt_delay);
23402 		rack->r_ctl.rc_pkt_delay = optval;
23403 		break;
23404 	case TCP_DELACK:
23405 		RACK_OPTS_INC(tcp_rack_delayed_ack);
23406 		if (optval == 0)
23407 			tp->t_delayed_ack = 0;
23408 		else
23409 			tp->t_delayed_ack = 1;
23410 		if (tp->t_flags & TF_DELACK) {
23411 			tp->t_flags &= ~TF_DELACK;
23412 			tp->t_flags |= TF_ACKNOW;
23413 			NET_EPOCH_ENTER(et);
23414 			rack_output(tp);
23415 			NET_EPOCH_EXIT(et);
23416 		}
23417 		break;
23418 
23419 	case TCP_BBR_RACK_RTT_USE:
23420 		RACK_OPTS_INC(tcp_rack_rtt_use);
23421 		if ((optval != USE_RTT_HIGH) &&
23422 		    (optval != USE_RTT_LOW) &&
23423 		    (optval != USE_RTT_AVG))
23424 			error = EINVAL;
23425 		else
23426 			rack->r_ctl.rc_rate_sample_method = optval;
23427 		break;
23428 	case TCP_HONOR_HPTS_MIN:
23429 		RACK_OPTS_INC(tcp_honor_hpts);
23430 		if (optval) {
23431 			rack->r_use_hpts_min = 1;
23432 			/*
23433 			 * Must be between 2 - 80% to be a reduction else
23434 			 * we keep the default (10%).
23435 			 */
23436 			if ((optval > 1) && (optval <= 80)) {
23437 				rack->r_ctl.max_reduction = optval;
23438 			}
23439 		} else
23440 			rack->r_use_hpts_min = 0;
23441 		break;
23442 	case TCP_REC_IS_DYN:			/*  URL:dynrec */
23443 		RACK_OPTS_INC(tcp_dyn_rec);
23444 		if (optval)
23445 			rack->rc_gp_no_rec_chg = 1;
23446 		else
23447 			rack->rc_gp_no_rec_chg = 0;
23448 		break;
23449 	case TCP_NO_TIMELY:
23450 		RACK_OPTS_INC(tcp_notimely);
23451 		if (optval) {
23452 			rack->rc_skip_timely = 1;
23453 			rack->r_ctl.rack_per_of_gp_rec = 90;
23454 			rack->r_ctl.rack_per_of_gp_ca = 100;
23455 			rack->r_ctl.rack_per_of_gp_ss = 250;
23456 		} else {
23457 			rack->rc_skip_timely = 0;
23458 		}
23459 		break;
23460 	case TCP_GP_USE_LTBW:
23461 		if (optval == 0) {
23462 			rack->use_lesser_lt_bw = 0;
23463 			rack->dis_lt_bw = 1;
23464 		} else if (optval == 1) {
23465 			rack->use_lesser_lt_bw = 1;
23466 			rack->dis_lt_bw = 0;
23467 		} else if (optval == 2) {
23468 			rack->use_lesser_lt_bw = 0;
23469 			rack->dis_lt_bw = 0;
23470 		}
23471 		break;
23472 	case TCP_DATA_AFTER_CLOSE:
23473 		RACK_OPTS_INC(tcp_data_after_close);
23474 		if (optval)
23475 			rack->rc_allow_data_af_clo = 1;
23476 		else
23477 			rack->rc_allow_data_af_clo = 0;
23478 		break;
23479 	default:
23480 		break;
23481 	}
23482 	tcp_log_socket_option(tp, sopt_name, optval, error);
23483 	return (error);
23484 }
23485 
23486 static void
23487 rack_inherit(struct tcpcb *tp, struct inpcb *parent)
23488 {
23489 	/*
23490 	 * A new connection has been created (tp) and
23491 	 * the parent is the inpcb given. We want to
23492 	 * apply a read-lock to the parent (we are already
23493 	 * holding a write lock on the tp) and copy anything
23494 	 * out of the rack specific data as long as its tfb is
23495 	 * the same as ours i.e. we are the same stack. Otherwise
23496 	 * we just return.
23497 	 */
23498 	struct tcpcb *par;
23499 	struct tcp_rack *dest, *src;
23500 	int cnt = 0;
23501 
23502 	par = intotcpcb(parent);
23503 	if (par->t_fb != tp->t_fb) {
23504 		/* Not the same stack */
23505 		tcp_log_socket_option(tp, 0, 0, 1);
23506 		return;
23507 	}
23508 	/* Ok if we reach here lets setup the two rack pointers */
23509 	dest = (struct tcp_rack *)tp->t_fb_ptr;
23510 	src = (struct tcp_rack *)par->t_fb_ptr;
23511 	if ((src == NULL) || (dest == NULL)) {
23512 		/* Huh? */
23513 		tcp_log_socket_option(tp, 0, 0, 2);
23514 		return;
23515 	}
23516 	/* Now copy out anything we wish to inherit i.e. things in socket-options */
23517 	/* TCP_RACK_PROFILE we can't know but we can set DGP if its on */
23518 	if ((src->dgp_on) && (dest->dgp_on == 0)) {
23519 		/* Profile 1 had to be set via sock opt */
23520 		rack_set_dgp(dest);
23521 		cnt++;
23522 	}
23523 	/* TCP_RACK_SET_RXT_OPTIONS */
23524 	if (dest->full_size_rxt != src->full_size_rxt) {
23525 		dest->full_size_rxt = src->full_size_rxt;
23526 		cnt++;
23527 	}
23528 	if (dest->shape_rxt_to_pacing_min  != src->shape_rxt_to_pacing_min) {
23529 		dest->shape_rxt_to_pacing_min = src->shape_rxt_to_pacing_min;
23530 		cnt++;
23531 	}
23532 	/* TCP_RACK_DSACK_OPT */
23533 	if (dest->rc_rack_tmr_std_based != src->rc_rack_tmr_std_based) {
23534 		dest->rc_rack_tmr_std_based = src->rc_rack_tmr_std_based;
23535 		cnt++;
23536 	}
23537 	if (dest->rc_rack_use_dsack != src->rc_rack_use_dsack) {
23538 		dest->rc_rack_use_dsack = src->rc_rack_use_dsack;
23539 		cnt++;
23540 	}
23541 	/* TCP_RACK_PACING_DIVISOR */
23542 	if (dest->r_ctl.pace_len_divisor != src->r_ctl.pace_len_divisor) {
23543 		dest->r_ctl.pace_len_divisor = src->r_ctl.pace_len_divisor;
23544 		cnt++;
23545 	}
23546 	/* TCP_RACK_HI_BETA */
23547 	if (src->rack_hibeta != dest->rack_hibeta) {
23548 		cnt++;
23549 		if (src->rack_hibeta) {
23550 			dest->r_ctl.rc_saved_beta = src->r_ctl.rc_saved_beta;
23551 			dest->rack_hibeta = 1;
23552 		} else {
23553 			dest->rack_hibeta = 0;
23554 		}
23555 	}
23556 	/* TCP_RACK_TIMER_SLOP */
23557 	if (dest->r_ctl.timer_slop != src->r_ctl.timer_slop) {
23558 		dest->r_ctl.timer_slop = src->r_ctl.timer_slop;
23559 		cnt++;
23560 	}
23561 	/* TCP_RACK_PACING_BETA_ECN */
23562 	if (dest->r_ctl.rc_saved_beta_ecn != src->r_ctl.rc_saved_beta_ecn) {
23563 		dest->r_ctl.rc_saved_beta_ecn = src->r_ctl.rc_saved_beta_ecn;
23564 		cnt++;
23565 	}
23566 	/* We do not do TCP_DEFER_OPTIONS */
23567 	/* TCP_RACK_MEASURE_CNT */
23568 	if (dest->r_ctl.req_measurements != src->r_ctl.req_measurements) {
23569 		dest->r_ctl.req_measurements = src->r_ctl.req_measurements;
23570 		cnt++;
23571 	}
23572 	/* TCP_HDWR_UP_ONLY */
23573 	if (dest->r_up_only != src->r_up_only) {
23574 		dest->r_up_only = src->r_up_only;
23575 		cnt++;
23576 	}
23577 	/* TCP_FILLCW_RATE_CAP */
23578 	if (dest->r_ctl.fillcw_cap != src->r_ctl.fillcw_cap) {
23579 		dest->r_ctl.fillcw_cap = src->r_ctl.fillcw_cap;
23580 		cnt++;
23581 	}
23582 	/* TCP_PACING_RATE_CAP */
23583 	if (dest->r_ctl.bw_rate_cap != src->r_ctl.bw_rate_cap) {
23584 		dest->r_ctl.bw_rate_cap = src->r_ctl.bw_rate_cap;
23585 		cnt++;
23586 	}
23587 	/* A listener can't set TCP_HYBRID_PACING */
23588 	/* TCP_SIDECHAN_DIS */
23589 	if (dest->r_ctl.side_chan_dis_mask != src->r_ctl.side_chan_dis_mask) {
23590 		dest->r_ctl.side_chan_dis_mask = src->r_ctl.side_chan_dis_mask;
23591 		cnt++;
23592 	}
23593 	/* TCP_SHARED_CWND_TIME_LIMIT */
23594 	if (dest->r_limit_scw != src->r_limit_scw) {
23595 		dest->r_limit_scw = src->r_limit_scw;
23596 		cnt++;
23597 	}
23598 	/* TCP_RACK_PACE_TO_FILL */
23599 	if (dest->rc_pace_to_cwnd != src->rc_pace_to_cwnd) {
23600 		dest->rc_pace_to_cwnd = src->rc_pace_to_cwnd;
23601 		cnt++;
23602 	}
23603 	if (dest->rc_pace_fill_if_rttin_range != src->rc_pace_fill_if_rttin_range) {
23604 		dest->rc_pace_fill_if_rttin_range = src->rc_pace_fill_if_rttin_range;
23605 		cnt++;
23606 	}
23607 	if (dest->rtt_limit_mul != src->rtt_limit_mul) {
23608 		dest->rtt_limit_mul = src->rtt_limit_mul;
23609 		cnt++;
23610 	}
23611 	/* TCP_RACK_NO_PUSH_AT_MAX */
23612 	if (dest->r_ctl.rc_no_push_at_mrtt != src->r_ctl.rc_no_push_at_mrtt) {
23613 		dest->r_ctl.rc_no_push_at_mrtt = src->r_ctl.rc_no_push_at_mrtt;
23614 		cnt++;
23615 	}
23616 	/* TCP_SHARED_CWND_ENABLE */
23617 	if (dest->rack_enable_scwnd != src->rack_enable_scwnd) {
23618 		dest->rack_enable_scwnd = src->rack_enable_scwnd;
23619 		cnt++;
23620 	}
23621 	/* TCP_USE_CMP_ACKS */
23622 	if (dest->r_use_cmp_ack != src->r_use_cmp_ack) {
23623 		dest->r_use_cmp_ack = src->r_use_cmp_ack;
23624 		cnt++;
23625 	}
23626 
23627 	if (dest->r_mbuf_queue != src->r_mbuf_queue) {
23628 		dest->r_mbuf_queue = src->r_mbuf_queue;
23629 		cnt++;
23630 	}
23631 	/* TCP_RACK_MBUF_QUEUE */
23632 	if (dest->r_mbuf_queue != src->r_mbuf_queue) {
23633 		dest->r_mbuf_queue = src->r_mbuf_queue;
23634 		cnt++;
23635 	}
23636 	if  (dest->r_mbuf_queue || dest->rc_always_pace || dest->r_use_cmp_ack) {
23637 		tp->t_flags2 |= TF2_SUPPORTS_MBUFQ;
23638 	} else {
23639 		tp->t_flags2 &= ~TF2_SUPPORTS_MBUFQ;
23640 	}
23641 	if (dest->r_use_cmp_ack && TCPS_HAVEESTABLISHED(tp->t_state)) {
23642 		tp->t_flags2 |= TF2_MBUF_ACKCMP;
23643 	}
23644 	/* TCP_RACK_NONRXT_CFG_RATE */
23645 	if (dest->rack_rec_nonrxt_use_cr != src->rack_rec_nonrxt_use_cr) {
23646 		dest->rack_rec_nonrxt_use_cr = src->rack_rec_nonrxt_use_cr;
23647 		cnt++;
23648 	}
23649 	/* TCP_NO_PRR */
23650 	if (dest->rack_no_prr != src->rack_no_prr) {
23651 		dest->rack_no_prr = src->rack_no_prr;
23652 		cnt++;
23653 	}
23654 	if (dest->no_prr_addback != src->no_prr_addback) {
23655 		dest->no_prr_addback = src->no_prr_addback;
23656 		cnt++;
23657 	}
23658 	/* RACK_CSPR_IS_FCC */
23659 	if (dest->cspr_is_fcc != src->cspr_is_fcc) {
23660 		dest->cspr_is_fcc = src->cspr_is_fcc;
23661 		cnt++;
23662 	}
23663 	/* TCP_TIMELY_DYN_ADJ */
23664 	if (dest->rc_gp_dyn_mul != src->rc_gp_dyn_mul) {
23665 		dest->rc_gp_dyn_mul = src->rc_gp_dyn_mul;
23666 		cnt++;
23667 	}
23668 	if (dest->r_ctl.rack_per_of_gp_ca != src->r_ctl.rack_per_of_gp_ca) {
23669 		dest->r_ctl.rack_per_of_gp_ca = src->r_ctl.rack_per_of_gp_ca;
23670 		cnt++;
23671 	}
23672 	/* TCP_RACK_TLP_USE */
23673 	if (dest->rack_tlp_threshold_use != src->rack_tlp_threshold_use) {
23674 		dest->rack_tlp_threshold_use = src->rack_tlp_threshold_use;
23675 		cnt++;
23676 	}
23677 	/* we don't allow inheritence of TCP_RACK_PACE_ALWAYS */
23678 	/* TCP_BBR_RACK_INIT_RATE */
23679 	if (dest->r_ctl.init_rate != src->r_ctl.init_rate) {
23680 		dest->r_ctl.init_rate = src->r_ctl.init_rate;
23681 		cnt++;
23682 	}
23683 	/* TCP_RACK_FORCE_MSEG */
23684 	if (dest->rc_force_max_seg != src->rc_force_max_seg) {
23685 		dest->rc_force_max_seg = src->rc_force_max_seg;
23686 		cnt++;
23687 	}
23688 	/* TCP_RACK_PACE_MIN_SEG */
23689 	if (dest->r_ctl.rc_user_set_min_segs != src->r_ctl.rc_user_set_min_segs) {
23690 		dest->r_ctl.rc_user_set_min_segs = src->r_ctl.rc_user_set_min_segs;
23691 		cnt++;
23692 	}
23693 	/* we don't allow TCP_RACK_PACE_MAX_SEG */
23694 	/* TCP_RACK_PACE_RATE_REC, TCP_RACK_PACE_RATE_SS,  TCP_RACK_PACE_RATE_CA */
23695 	if (dest->r_ctl.rc_fixed_pacing_rate_ca != src->r_ctl.rc_fixed_pacing_rate_ca) {
23696 		dest->r_ctl.rc_fixed_pacing_rate_ca = src->r_ctl.rc_fixed_pacing_rate_ca;
23697 		cnt++;
23698 	}
23699 	if (dest->r_ctl.rc_fixed_pacing_rate_ss != src->r_ctl.rc_fixed_pacing_rate_ss) {
23700 		dest->r_ctl.rc_fixed_pacing_rate_ss = src->r_ctl.rc_fixed_pacing_rate_ss;
23701 		cnt++;
23702 	}
23703 	if (dest->r_ctl.rc_fixed_pacing_rate_rec != src->r_ctl.rc_fixed_pacing_rate_rec) {
23704 		dest->r_ctl.rc_fixed_pacing_rate_rec = src->r_ctl.rc_fixed_pacing_rate_rec;
23705 		cnt++;
23706 	}
23707 	/* TCP_RACK_GP_INCREASE_REC, TCP_RACK_GP_INCREASE_CA, TCP_RACK_GP_INCREASE_SS */
23708 	if (dest->r_ctl.rack_per_of_gp_rec != src->r_ctl.rack_per_of_gp_rec) {
23709 		dest->r_ctl.rack_per_of_gp_rec = src->r_ctl.rack_per_of_gp_rec;
23710 		cnt++;
23711 	}
23712 	if (dest->r_ctl.rack_per_of_gp_ca != src->r_ctl.rack_per_of_gp_ca) {
23713 		dest->r_ctl.rack_per_of_gp_ca = src->r_ctl.rack_per_of_gp_ca;
23714 		cnt++;
23715 	}
23716 
23717 	if (dest->r_ctl.rack_per_of_gp_ss != src->r_ctl.rack_per_of_gp_ss) {
23718 		dest->r_ctl.rack_per_of_gp_ss = src->r_ctl.rack_per_of_gp_ss;
23719 		cnt++;
23720 	}
23721 	/* TCP_RACK_RR_CONF */
23722 	if (dest->r_rr_config != src->r_rr_config) {
23723 		dest->r_rr_config = src->r_rr_config;
23724 		cnt++;
23725 	}
23726 	/* TCP_PACING_DND */
23727 	if (dest->rc_pace_dnd != src->rc_pace_dnd) {
23728 		dest->rc_pace_dnd = src->rc_pace_dnd;
23729 		cnt++;
23730 	}
23731 	/* TCP_HDWR_RATE_CAP */
23732 	if (dest->r_rack_hw_rate_caps != src->r_rack_hw_rate_caps) {
23733 		dest->r_rack_hw_rate_caps = src->r_rack_hw_rate_caps;
23734 		cnt++;
23735 	}
23736 	/* TCP_DGP_UPPER_BOUNDS */
23737 	if (dest->r_ctl.rack_per_upper_bound_ca != src->r_ctl.rack_per_upper_bound_ca) {
23738 		dest->r_ctl.rack_per_upper_bound_ca = src->r_ctl.rack_per_upper_bound_ca;
23739 		cnt++;
23740 	}
23741 	if (dest->r_ctl.rack_per_upper_bound_ss != src->r_ctl.rack_per_upper_bound_ss) {
23742 		dest->r_ctl.rack_per_upper_bound_ss = src->r_ctl.rack_per_upper_bound_ss;
23743 		cnt++;
23744 	}
23745 	/* TCP_SS_EEXIT */
23746 	if (dest->r_ctl.gp_rnd_thresh != src->r_ctl.gp_rnd_thresh) {
23747 		dest->r_ctl.gp_rnd_thresh = src->r_ctl.gp_rnd_thresh;
23748 		cnt++;
23749 	}
23750 	if (dest->r_ctl.gate_to_fs != src->r_ctl.gate_to_fs) {
23751 		dest->r_ctl.gate_to_fs = src->r_ctl.gate_to_fs;
23752 		cnt++;
23753 	}
23754 	if (dest->r_ctl.use_gp_not_last != src->r_ctl.use_gp_not_last) {
23755 		dest->r_ctl.use_gp_not_last = src->r_ctl.use_gp_not_last;
23756 		cnt++;
23757 	}
23758 	if (dest->r_ctl.gp_gain_req != src->r_ctl.gp_gain_req) {
23759 		dest->r_ctl.gp_gain_req = src->r_ctl.gp_gain_req;
23760 		cnt++;
23761 	}
23762 	/* TCP_BBR_HDWR_PACE */
23763 	if (dest->rack_hdw_pace_ena != src->rack_hdw_pace_ena) {
23764 		dest->rack_hdw_pace_ena = src->rack_hdw_pace_ena;
23765 		cnt++;
23766 	}
23767 	if (dest->rack_attempt_hdwr_pace != src->rack_attempt_hdwr_pace) {
23768 		dest->rack_attempt_hdwr_pace = src->rack_attempt_hdwr_pace;
23769 		cnt++;
23770 	}
23771 	/* TCP_RACK_PRR_SENDALOT */
23772 	if (dest->r_ctl.rc_prr_sendalot != src->r_ctl.rc_prr_sendalot) {
23773 		dest->r_ctl.rc_prr_sendalot = src->r_ctl.rc_prr_sendalot;
23774 		cnt++;
23775 	}
23776 	/* TCP_RACK_MIN_TO */
23777 	if (dest->r_ctl.rc_min_to != src->r_ctl.rc_min_to) {
23778 		dest->r_ctl.rc_min_to = src->r_ctl.rc_min_to;
23779 		cnt++;
23780 	}
23781 	/* TCP_RACK_EARLY_SEG */
23782 	if (dest->r_ctl.rc_early_recovery_segs != src->r_ctl.rc_early_recovery_segs) {
23783 		dest->r_ctl.rc_early_recovery_segs = src->r_ctl.rc_early_recovery_segs;
23784 		cnt++;
23785 	}
23786 	/* TCP_RACK_ENABLE_HYSTART */
23787 	if (par->t_ccv.flags != tp->t_ccv.flags) {
23788 		cnt++;
23789 		if (par->t_ccv.flags & CCF_HYSTART_ALLOWED) {
23790 			tp->t_ccv.flags |= CCF_HYSTART_ALLOWED;
23791 			if (rack_do_hystart > RACK_HYSTART_ON)
23792 				tp->t_ccv.flags |= CCF_HYSTART_CAN_SH_CWND;
23793 			if (rack_do_hystart > RACK_HYSTART_ON_W_SC)
23794 				tp->t_ccv.flags |= CCF_HYSTART_CONS_SSTH;
23795 		} else {
23796 			tp->t_ccv.flags &= ~(CCF_HYSTART_ALLOWED|CCF_HYSTART_CAN_SH_CWND|CCF_HYSTART_CONS_SSTH);
23797 		}
23798 	}
23799 	/* TCP_RACK_REORD_THRESH */
23800 	if (dest->r_ctl.rc_reorder_shift != src->r_ctl.rc_reorder_shift) {
23801 		dest->r_ctl.rc_reorder_shift = src->r_ctl.rc_reorder_shift;
23802 		cnt++;
23803 	}
23804 	/* TCP_RACK_REORD_FADE */
23805 	if (dest->r_ctl.rc_reorder_fade != src->r_ctl.rc_reorder_fade) {
23806 		dest->r_ctl.rc_reorder_fade = src->r_ctl.rc_reorder_fade;
23807 		cnt++;
23808 	}
23809 	/* TCP_RACK_TLP_THRESH */
23810 	if (dest->r_ctl.rc_tlp_threshold != src->r_ctl.rc_tlp_threshold) {
23811 		dest->r_ctl.rc_tlp_threshold = src->r_ctl.rc_tlp_threshold;
23812 		cnt++;
23813 	}
23814 	/* TCP_BBR_USE_RACK_RR */
23815 	if (dest->use_rack_rr != src->use_rack_rr) {
23816 		dest->use_rack_rr = src->use_rack_rr;
23817 		cnt++;
23818 	}
23819 	/* TCP_RACK_PKT_DELAY */
23820 	if (dest->r_ctl.rc_pkt_delay != src->r_ctl.rc_pkt_delay) {
23821 		dest->r_ctl.rc_pkt_delay = src->r_ctl.rc_pkt_delay;
23822 		cnt++;
23823 	}
23824 	/* TCP_DELACK will get copied via the main code if applicable */
23825 	/* TCP_BBR_RACK_RTT_USE */
23826 	if (dest->r_ctl.rc_rate_sample_method != src->r_ctl.rc_rate_sample_method) {
23827 		dest->r_ctl.rc_rate_sample_method = src->r_ctl.rc_rate_sample_method;
23828 		cnt++;
23829 	}
23830 	/* TCP_HONOR_HPTS_MIN */
23831 	if (dest->r_use_hpts_min != src->r_use_hpts_min) {
23832 		dest->r_use_hpts_min = src->r_use_hpts_min;
23833 		cnt++;
23834 	}
23835 	if (dest->r_ctl.max_reduction != src->r_ctl.max_reduction) {
23836 		dest->r_ctl.max_reduction = src->r_ctl.max_reduction;
23837 		cnt++;
23838 	}
23839 	/* TCP_REC_IS_DYN */
23840 	if (dest->rc_gp_no_rec_chg != src->rc_gp_no_rec_chg) {
23841 		dest->rc_gp_no_rec_chg = src->rc_gp_no_rec_chg;
23842 		cnt++;
23843 	}
23844 	if (dest->rc_skip_timely != src->rc_skip_timely) {
23845 		dest->rc_skip_timely = src->rc_skip_timely;
23846 		cnt++;
23847 	}
23848 	/* TCP_DATA_AFTER_CLOSE */
23849 	if (dest->rc_allow_data_af_clo != src->rc_allow_data_af_clo) {
23850 		dest->rc_allow_data_af_clo = src->rc_allow_data_af_clo;
23851 		cnt++;
23852 	}
23853 	/* TCP_GP_USE_LTBW */
23854 	if (src->use_lesser_lt_bw != dest->use_lesser_lt_bw) {
23855 		dest->use_lesser_lt_bw = src->use_lesser_lt_bw;
23856 		cnt++;
23857 	}
23858 	if (dest->dis_lt_bw != src->dis_lt_bw) {
23859 		dest->dis_lt_bw = src->dis_lt_bw;
23860 		cnt++;
23861 	}
23862 	tcp_log_socket_option(tp, 0, cnt, 0);
23863 }
23864 
23865 
23866 static void
23867 rack_apply_deferred_options(struct tcp_rack *rack)
23868 {
23869 	struct deferred_opt_list *dol, *sdol;
23870 	uint32_t s_optval;
23871 
23872 	TAILQ_FOREACH_SAFE(dol, &rack->r_ctl.opt_list, next, sdol) {
23873 		TAILQ_REMOVE(&rack->r_ctl.opt_list, dol, next);
23874 		/* Disadvantage of deferal is you loose the error return */
23875 		s_optval = (uint32_t)dol->optval;
23876 		(void)rack_process_option(rack->rc_tp, rack, dol->optname, s_optval, dol->optval, NULL);
23877 		free(dol, M_TCPDO);
23878 	}
23879 }
23880 
23881 static void
23882 rack_hw_tls_change(struct tcpcb *tp, int chg)
23883 {
23884 	/* Update HW tls state */
23885 	struct tcp_rack *rack;
23886 
23887 	rack = (struct tcp_rack *)tp->t_fb_ptr;
23888 	if (chg)
23889 		rack->r_ctl.fsb.hw_tls = 1;
23890 	else
23891 		rack->r_ctl.fsb.hw_tls = 0;
23892 }
23893 
23894 static int
23895 rack_pru_options(struct tcpcb *tp, int flags)
23896 {
23897 	if (flags & PRUS_OOB)
23898 		return (EOPNOTSUPP);
23899 	return (0);
23900 }
23901 
23902 static bool
23903 rack_wake_check(struct tcpcb *tp)
23904 {
23905 	struct tcp_rack *rack;
23906 	struct timeval tv;
23907 	uint32_t cts;
23908 
23909 	rack = (struct tcp_rack *)tp->t_fb_ptr;
23910 	if (rack->r_ctl.rc_hpts_flags) {
23911 		cts = tcp_get_usecs(&tv);
23912 		if ((rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT) == PACE_PKT_OUTPUT){
23913 			/*
23914 			 * Pacing timer is up, check if we are ready.
23915 			 */
23916 			if (TSTMP_GEQ(cts, rack->r_ctl.rc_last_output_to))
23917 				return (true);
23918 		} else if ((rack->r_ctl.rc_hpts_flags & PACE_TMR_MASK) != 0) {
23919 			/*
23920 			 * A timer is up, check if we are ready.
23921 			 */
23922 			if (TSTMP_GEQ(cts, rack->r_ctl.rc_timer_exp))
23923 				return (true);
23924 		}
23925 	}
23926 	return (false);
23927 }
23928 
23929 static struct tcp_function_block __tcp_rack = {
23930 	.tfb_tcp_block_name = __XSTRING(STACKNAME),
23931 	.tfb_tcp_output = rack_output,
23932 	.tfb_do_queued_segments = ctf_do_queued_segments,
23933 	.tfb_do_segment_nounlock = rack_do_segment_nounlock,
23934 	.tfb_tcp_do_segment = rack_do_segment,
23935 	.tfb_tcp_ctloutput = rack_ctloutput,
23936 	.tfb_tcp_fb_init = rack_init,
23937 	.tfb_tcp_fb_fini = rack_fini,
23938 	.tfb_tcp_timer_stop_all = rack_stopall,
23939 	.tfb_tcp_rexmit_tmr = rack_remxt_tmr,
23940 	.tfb_tcp_handoff_ok = rack_handoff_ok,
23941 	.tfb_tcp_mtu_chg = rack_mtu_change,
23942 	.tfb_pru_options = rack_pru_options,
23943 	.tfb_hwtls_change = rack_hw_tls_change,
23944 	.tfb_chg_query = rack_chg_query,
23945 	.tfb_switch_failed = rack_switch_failed,
23946 	.tfb_early_wake_check = rack_wake_check,
23947 	.tfb_compute_pipe = rack_compute_pipe,
23948 	.tfb_stack_info = rack_stack_information,
23949 	.tfb_inherit = rack_inherit,
23950 	.tfb_flags = TCP_FUNC_OUTPUT_CANDROP | TCP_FUNC_DEFAULT_OK,
23951 
23952 };
23953 
23954 /*
23955  * rack_ctloutput() must drop the inpcb lock before performing copyin on
23956  * socket option arguments.  When it re-acquires the lock after the copy, it
23957  * has to revalidate that the connection is still valid for the socket
23958  * option.
23959  */
23960 static int
23961 rack_set_sockopt(struct tcpcb *tp, struct sockopt *sopt)
23962 {
23963 	struct inpcb *inp = tptoinpcb(tp);
23964 #ifdef INET
23965 	struct ip *ip;
23966 #endif
23967 	struct tcp_rack *rack;
23968 	struct tcp_hybrid_req hybrid;
23969 	uint64_t loptval;
23970 	int32_t error = 0, optval;
23971 
23972 	rack = (struct tcp_rack *)tp->t_fb_ptr;
23973 	if (rack == NULL) {
23974 		INP_WUNLOCK(inp);
23975 		return (EINVAL);
23976 	}
23977 #ifdef INET
23978 	ip = (struct ip *)rack->r_ctl.fsb.tcp_ip_hdr;
23979 #endif
23980 
23981 	switch (sopt->sopt_level) {
23982 #ifdef INET6
23983 	case IPPROTO_IPV6:
23984 		MPASS(inp->inp_vflag & INP_IPV6PROTO);
23985 		switch (sopt->sopt_name) {
23986 		case IPV6_USE_MIN_MTU:
23987 			tcp6_use_min_mtu(tp);
23988 			break;
23989 		}
23990 		INP_WUNLOCK(inp);
23991 		return (0);
23992 #endif
23993 #ifdef INET
23994 	case IPPROTO_IP:
23995 		switch (sopt->sopt_name) {
23996 		case IP_TOS:
23997 			/*
23998 			 * The DSCP codepoint has changed, update the fsb.
23999 			 */
24000 			ip->ip_tos = rack->rc_inp->inp_ip_tos;
24001 			break;
24002 		case IP_TTL:
24003 			/*
24004 			 * The TTL has changed, update the fsb.
24005 			 */
24006 			ip->ip_ttl = rack->rc_inp->inp_ip_ttl;
24007 			break;
24008 		}
24009 		INP_WUNLOCK(inp);
24010 		return (0);
24011 #endif
24012 #ifdef SO_PEERPRIO
24013 	case SOL_SOCKET:
24014 		switch (sopt->sopt_name) {
24015 		case SO_PEERPRIO:			/*  SC-URL:bs */
24016 			/* Already read in and sanity checked in sosetopt(). */
24017 			if (inp->inp_socket) {
24018 				rack->client_bufferlvl = inp->inp_socket->so_peerprio;
24019 			}
24020 			break;
24021 		}
24022 		INP_WUNLOCK(inp);
24023 		return (0);
24024 #endif
24025 	case IPPROTO_TCP:
24026 		switch (sopt->sopt_name) {
24027 		case TCP_RACK_TLP_REDUCE:		/*  URL:tlp_reduce */
24028 		/*  Pacing related ones */
24029 		case TCP_RACK_PACE_ALWAYS:		/*  URL:pace_always */
24030 		case TCP_BBR_RACK_INIT_RATE:		/*  URL:irate */
24031 		case TCP_RACK_PACE_MIN_SEG:		/*  URL:pace_min_seg */
24032 		case TCP_RACK_PACE_MAX_SEG:		/*  URL:pace_max_seg */
24033 		case TCP_RACK_FORCE_MSEG:		/*  URL:force_max_seg */
24034 		case TCP_RACK_PACE_RATE_CA:		/*  URL:pr_ca */
24035 		case TCP_RACK_PACE_RATE_SS:		/*  URL:pr_ss*/
24036 		case TCP_RACK_PACE_RATE_REC:		/*  URL:pr_rec */
24037 		case TCP_RACK_GP_INCREASE_CA:		/*  URL:gp_inc_ca */
24038 		case TCP_RACK_GP_INCREASE_SS:		/*  URL:gp_inc_ss */
24039 		case TCP_RACK_GP_INCREASE_REC:		/*  URL:gp_inc_rec */
24040 		case TCP_RACK_RR_CONF:			/*  URL:rrr_conf */
24041 		case TCP_BBR_HDWR_PACE:			/*  URL:hdwrpace */
24042 		case TCP_HDWR_RATE_CAP:			/*  URL:hdwrcap boolean */
24043 		case TCP_PACING_RATE_CAP:		/*  URL:cap  -- used by side-channel */
24044 		case TCP_HDWR_UP_ONLY:			/*  URL:uponly -- hardware pacing  boolean */
24045 		case TCP_FILLCW_RATE_CAP:		/*  URL:fillcw_cap */
24046 		case TCP_RACK_PACING_BETA_ECN:		/*  URL:pacing_beta_ecn */
24047 		case TCP_RACK_PACE_TO_FILL:		/*  URL:fillcw */
24048 			/* End pacing related */
24049 		case TCP_DELACK:			/*  URL:delack (in base TCP i.e. tcp_hints along with cc etc ) */
24050 		case TCP_RACK_PRR_SENDALOT:		/*  URL:prr_sendalot */
24051 		case TCP_RACK_MIN_TO:			/*  URL:min_to */
24052 		case TCP_RACK_EARLY_SEG:		/*  URL:early_seg */
24053 		case TCP_RACK_REORD_THRESH:		/*  URL:reord_thresh */
24054 		case TCP_RACK_REORD_FADE:		/*  URL:reord_fade */
24055 		case TCP_RACK_TLP_THRESH:		/*  URL:tlp_thresh */
24056 		case TCP_RACK_PKT_DELAY:		/*  URL:pkt_delay */
24057 		case TCP_RACK_TLP_USE:			/*  URL:tlp_use */
24058 		case TCP_BBR_RACK_RTT_USE:		/*  URL:rttuse */
24059 		case TCP_BBR_USE_RACK_RR:		/*  URL:rackrr */
24060 		case TCP_NO_PRR:			/*  URL:noprr */
24061 		case TCP_TIMELY_DYN_ADJ:      		/*  URL:dynamic */
24062 		case TCP_DATA_AFTER_CLOSE:		/*  no URL */
24063 		case TCP_RACK_NONRXT_CFG_RATE:		/*  URL:nonrxtcr */
24064 		case TCP_SHARED_CWND_ENABLE:		/*  URL:scwnd */
24065 		case TCP_RACK_MBUF_QUEUE:		/*  URL:mqueue */
24066 		case TCP_RACK_NO_PUSH_AT_MAX:		/*  URL:npush */
24067 		case TCP_SHARED_CWND_TIME_LIMIT:	/*  URL:lscwnd */
24068 		case TCP_RACK_PROFILE:			/*  URL:profile */
24069 		case TCP_SIDECHAN_DIS:			/*  URL:scodm */
24070 		case TCP_HYBRID_PACING:			/*  URL:pacing=hybrid */
24071 		case TCP_USE_CMP_ACKS:			/*  URL:cmpack */
24072 		case TCP_RACK_ABC_VAL:			/*  URL:labc */
24073 		case TCP_REC_ABC_VAL:			/*  URL:reclabc */
24074 		case TCP_RACK_MEASURE_CNT:		/*  URL:measurecnt */
24075 		case TCP_DEFER_OPTIONS:			/*  URL:defer */
24076 		case TCP_RACK_DSACK_OPT:		/*  URL:dsack */
24077 		case TCP_RACK_TIMER_SLOP:		/*  URL:timer_slop */
24078 		case TCP_RACK_ENABLE_HYSTART:		/*  URL:hystart */
24079 		case TCP_RACK_SET_RXT_OPTIONS:		/*  URL:rxtsz */
24080 		case TCP_RACK_HI_BETA:			/*  URL:hibeta */
24081 		case TCP_RACK_SPLIT_LIMIT:		/*  URL:split */
24082 		case TCP_SS_EEXIT:			/*  URL:eexit */
24083 		case TCP_DGP_UPPER_BOUNDS:		/*  URL:upper */
24084 		case TCP_RACK_PACING_DIVISOR:		/*  URL:divisor */
24085 		case TCP_PACING_DND:			/*  URL:dnd */
24086 		case TCP_NO_TIMELY:			/*  URL:notimely */
24087 		case RACK_CSPR_IS_FCC:			/*  URL:csprisfcc */
24088 		case TCP_HONOR_HPTS_MIN:		/*  URL:hptsmin */
24089 		case TCP_REC_IS_DYN:			/*  URL:dynrec */
24090 		case TCP_GP_USE_LTBW:			/*  URL:useltbw */
24091 			goto process_opt;
24092 			break;
24093 		default:
24094 			/* Filter off all unknown options to the base stack */
24095 			return (tcp_default_ctloutput(tp, sopt));
24096 			break;
24097 		}
24098 	default:
24099 		INP_WUNLOCK(inp);
24100 		return (0);
24101 	}
24102 process_opt:
24103 	INP_WUNLOCK(inp);
24104 	if ((sopt->sopt_name == TCP_PACING_RATE_CAP) ||
24105 	    (sopt->sopt_name == TCP_FILLCW_RATE_CAP)) {
24106 		error = sooptcopyin(sopt, &loptval, sizeof(loptval), sizeof(loptval));
24107 		/*
24108 		 * We truncate it down to 32 bits for the socket-option trace this
24109 		 * means rates > 34Gbps won't show right, but thats probably ok.
24110 		 */
24111 		optval = (uint32_t)loptval;
24112 	} else if (sopt->sopt_name == TCP_HYBRID_PACING) {
24113 		error = sooptcopyin(sopt, &hybrid, sizeof(hybrid), sizeof(hybrid));
24114 	} else {
24115 		error = sooptcopyin(sopt, &optval, sizeof(optval), sizeof(optval));
24116 		/* Save it in 64 bit form too */
24117 		loptval = optval;
24118 	}
24119 	if (error)
24120 		return (error);
24121 	INP_WLOCK(inp);
24122 	if (tp->t_fb != &__tcp_rack) {
24123 		INP_WUNLOCK(inp);
24124 		return (ENOPROTOOPT);
24125 	}
24126 	if (rack->defer_options && (rack->gp_ready == 0) &&
24127 	    (sopt->sopt_name != TCP_DEFER_OPTIONS) &&
24128 	    (sopt->sopt_name != TCP_HYBRID_PACING) &&
24129 	    (sopt->sopt_name != TCP_RACK_SET_RXT_OPTIONS) &&
24130 	    (sopt->sopt_name != TCP_RACK_PACING_BETA_ECN) &&
24131 	    (sopt->sopt_name != TCP_RACK_MEASURE_CNT)) {
24132 		/* Options are being deferred */
24133 		if (rack_add_deferred_option(rack, sopt->sopt_name, loptval)) {
24134 			INP_WUNLOCK(inp);
24135 			return (0);
24136 		} else {
24137 			/* No memory to defer, fail */
24138 			INP_WUNLOCK(inp);
24139 			return (ENOMEM);
24140 		}
24141 	}
24142 	error = rack_process_option(tp, rack, sopt->sopt_name, optval, loptval, &hybrid);
24143 	INP_WUNLOCK(inp);
24144 	return (error);
24145 }
24146 
24147 static void
24148 rack_fill_info(struct tcpcb *tp, struct tcp_info *ti)
24149 {
24150 
24151 	INP_WLOCK_ASSERT(tptoinpcb(tp));
24152 	bzero(ti, sizeof(*ti));
24153 
24154 	ti->tcpi_state = tp->t_state;
24155 	if ((tp->t_flags & TF_REQ_TSTMP) && (tp->t_flags & TF_RCVD_TSTMP))
24156 		ti->tcpi_options |= TCPI_OPT_TIMESTAMPS;
24157 	if (tp->t_flags & TF_SACK_PERMIT)
24158 		ti->tcpi_options |= TCPI_OPT_SACK;
24159 	if ((tp->t_flags & TF_REQ_SCALE) && (tp->t_flags & TF_RCVD_SCALE)) {
24160 		ti->tcpi_options |= TCPI_OPT_WSCALE;
24161 		ti->tcpi_snd_wscale = tp->snd_scale;
24162 		ti->tcpi_rcv_wscale = tp->rcv_scale;
24163 	}
24164 	if (tp->t_flags2 & (TF2_ECN_PERMIT | TF2_ACE_PERMIT))
24165 		ti->tcpi_options |= TCPI_OPT_ECN;
24166 	if (tp->t_flags & TF_FASTOPEN)
24167 		ti->tcpi_options |= TCPI_OPT_TFO;
24168 	/* still kept in ticks is t_rcvtime */
24169 	ti->tcpi_last_data_recv = ((uint32_t)ticks - tp->t_rcvtime) * tick;
24170 	/* Since we hold everything in precise useconds this is easy */
24171 	ti->tcpi_rtt = tp->t_srtt;
24172 	ti->tcpi_rttvar = tp->t_rttvar;
24173 	ti->tcpi_rto = tp->t_rxtcur;
24174 	ti->tcpi_snd_ssthresh = tp->snd_ssthresh;
24175 	ti->tcpi_snd_cwnd = tp->snd_cwnd;
24176 	/*
24177 	 * FreeBSD-specific extension fields for tcp_info.
24178 	 */
24179 	ti->tcpi_rcv_space = tp->rcv_wnd;
24180 	ti->tcpi_rcv_nxt = tp->rcv_nxt;
24181 	ti->tcpi_snd_wnd = tp->snd_wnd;
24182 	ti->tcpi_snd_bwnd = 0;		/* Unused, kept for compat. */
24183 	ti->tcpi_snd_nxt = tp->snd_nxt;
24184 	ti->tcpi_snd_mss = tp->t_maxseg;
24185 	ti->tcpi_rcv_mss = tp->t_maxseg;
24186 	ti->tcpi_snd_rexmitpack = tp->t_sndrexmitpack;
24187 	ti->tcpi_rcv_ooopack = tp->t_rcvoopack;
24188 	ti->tcpi_snd_zerowin = tp->t_sndzerowin;
24189 	ti->tcpi_total_tlp = tp->t_sndtlppack;
24190 	ti->tcpi_total_tlp_bytes = tp->t_sndtlpbyte;
24191 	ti->tcpi_rttmin = tp->t_rttlow;
24192 #ifdef NETFLIX_STATS
24193 	memcpy(&ti->tcpi_rxsyninfo, &tp->t_rxsyninfo, sizeof(struct tcpsyninfo));
24194 #endif
24195 #ifdef TCP_OFFLOAD
24196 	if (tp->t_flags & TF_TOE) {
24197 		ti->tcpi_options |= TCPI_OPT_TOE;
24198 		tcp_offload_tcp_info(tp, ti);
24199 	}
24200 #endif
24201 }
24202 
24203 static int
24204 rack_get_sockopt(struct tcpcb *tp, struct sockopt *sopt)
24205 {
24206 	struct inpcb *inp = tptoinpcb(tp);
24207 	struct tcp_rack *rack;
24208 	int32_t error, optval;
24209 	uint64_t val, loptval;
24210 	struct	tcp_info ti;
24211 	/*
24212 	 * Because all our options are either boolean or an int, we can just
24213 	 * pull everything into optval and then unlock and copy. If we ever
24214 	 * add a option that is not a int, then this will have quite an
24215 	 * impact to this routine.
24216 	 */
24217 	error = 0;
24218 	rack = (struct tcp_rack *)tp->t_fb_ptr;
24219 	if (rack == NULL) {
24220 		INP_WUNLOCK(inp);
24221 		return (EINVAL);
24222 	}
24223 	switch (sopt->sopt_name) {
24224 	case TCP_INFO:
24225 		/* First get the info filled */
24226 		rack_fill_info(tp, &ti);
24227 		/* Fix up the rtt related fields if needed */
24228 		INP_WUNLOCK(inp);
24229 		error = sooptcopyout(sopt, &ti, sizeof ti);
24230 		return (error);
24231 	/*
24232 	 * Beta is the congestion control value for NewReno that influences how
24233 	 * much of a backoff happens when loss is detected. It is normally set
24234 	 * to 50 for 50% i.e. the cwnd is reduced to 50% of its previous value
24235 	 * when you exit recovery.
24236 	 */
24237 	case TCP_RACK_PACING_BETA:
24238 		if (strcmp(tp->t_cc->name, CCALGONAME_NEWRENO) != 0)
24239 			error = EINVAL;
24240 		else if (rack->rc_pacing_cc_set == 0)
24241 			optval = rack->r_ctl.rc_saved_beta;
24242 		else {
24243 			/*
24244 			 * Reach out into the CC data and report back what
24245 			 * I have previously set. Yeah it looks hackish but
24246 			 * we don't want to report the saved values.
24247 			 */
24248 			if (tp->t_ccv.cc_data)
24249 				optval = ((struct newreno *)tp->t_ccv.cc_data)->beta;
24250 			else
24251 				error = EINVAL;
24252 		}
24253 		break;
24254 	/*
24255 	 * Beta_ecn is the congestion control value for NewReno that influences how
24256 	 * much of a backoff happens when a ECN mark is detected. It is normally set
24257 	 * to 80 for 80% i.e. the cwnd is reduced by 20% of its previous value when
24258 	 * you exit recovery. Note that classic ECN has a beta of 50, it is only
24259 	 * ABE Ecn that uses this "less" value, but we do too with pacing :)
24260 	 */
24261 	case TCP_RACK_PACING_BETA_ECN:
24262 		if (strcmp(tp->t_cc->name, CCALGONAME_NEWRENO) != 0)
24263 			error = EINVAL;
24264 		else if (rack->rc_pacing_cc_set == 0)
24265 			optval = rack->r_ctl.rc_saved_beta_ecn;
24266 		else {
24267 			/*
24268 			 * Reach out into the CC data and report back what
24269 			 * I have previously set. Yeah it looks hackish but
24270 			 * we don't want to report the saved values.
24271 			 */
24272 			if (tp->t_ccv.cc_data)
24273 				optval = ((struct newreno *)tp->t_ccv.cc_data)->beta_ecn;
24274 			else
24275 				error = EINVAL;
24276 		}
24277 		break;
24278 	case TCP_RACK_DSACK_OPT:
24279 		optval = 0;
24280 		if (rack->rc_rack_tmr_std_based) {
24281 			optval |= 1;
24282 		}
24283 		if (rack->rc_rack_use_dsack) {
24284 			optval |= 2;
24285 		}
24286 		break;
24287 	case TCP_RACK_ENABLE_HYSTART:
24288 	{
24289 		if (tp->t_ccv.flags & CCF_HYSTART_ALLOWED) {
24290 			optval = RACK_HYSTART_ON;
24291 			if (tp->t_ccv.flags & CCF_HYSTART_CAN_SH_CWND)
24292 				optval = RACK_HYSTART_ON_W_SC;
24293 			if (tp->t_ccv.flags & CCF_HYSTART_CONS_SSTH)
24294 				optval = RACK_HYSTART_ON_W_SC_C;
24295 		} else {
24296 			optval = RACK_HYSTART_OFF;
24297 		}
24298 	}
24299 	break;
24300 	case TCP_RACK_DGP_IN_REC:
24301 		error = EINVAL;
24302 		break;
24303 	case TCP_RACK_HI_BETA:
24304 		optval = rack->rack_hibeta;
24305 		break;
24306 	case TCP_DEFER_OPTIONS:
24307 		optval = rack->defer_options;
24308 		break;
24309 	case TCP_RACK_MEASURE_CNT:
24310 		optval = rack->r_ctl.req_measurements;
24311 		break;
24312 	case TCP_REC_ABC_VAL:
24313 		optval = rack->r_use_labc_for_rec;
24314 		break;
24315 	case TCP_RACK_ABC_VAL:
24316 		optval = rack->rc_labc;
24317 		break;
24318 	case TCP_HDWR_UP_ONLY:
24319 		optval= rack->r_up_only;
24320 		break;
24321 	case TCP_FILLCW_RATE_CAP:
24322 		loptval = rack->r_ctl.fillcw_cap;
24323 		break;
24324 	case TCP_PACING_RATE_CAP:
24325 		loptval = rack->r_ctl.bw_rate_cap;
24326 		break;
24327 	case TCP_RACK_PROFILE:
24328 		/* You cannot retrieve a profile, its write only */
24329 		error = EINVAL;
24330 		break;
24331 	case TCP_SIDECHAN_DIS:
24332 		optval = rack->r_ctl.side_chan_dis_mask;
24333 		break;
24334 	case TCP_HYBRID_PACING:
24335 		/* You cannot retrieve hybrid pacing information, its write only */
24336 		error = EINVAL;
24337 		break;
24338 	case TCP_USE_CMP_ACKS:
24339 		optval = rack->r_use_cmp_ack;
24340 		break;
24341 	case TCP_RACK_PACE_TO_FILL:
24342 		optval = rack->rc_pace_to_cwnd;
24343 		break;
24344 	case TCP_RACK_NO_PUSH_AT_MAX:
24345 		optval = rack->r_ctl.rc_no_push_at_mrtt;
24346 		break;
24347 	case TCP_SHARED_CWND_ENABLE:
24348 		optval = rack->rack_enable_scwnd;
24349 		break;
24350 	case TCP_RACK_NONRXT_CFG_RATE:
24351 		optval = rack->rack_rec_nonrxt_use_cr;
24352 		break;
24353 	case TCP_NO_PRR:
24354 		if (rack->rack_no_prr  == 1)
24355 			optval = 1;
24356 		else if (rack->no_prr_addback == 1)
24357 			optval = 2;
24358 		else
24359 			optval = 0;
24360 		break;
24361 	case TCP_GP_USE_LTBW:
24362 		if (rack->dis_lt_bw) {
24363 			/* It is not used */
24364 			optval = 0;
24365 		} else if (rack->use_lesser_lt_bw) {
24366 			/* we use min() */
24367 			optval = 1;
24368 		} else {
24369 			/* we use max() */
24370 			optval = 2;
24371 		}
24372 		break;
24373 	case TCP_RACK_DO_DETECTION:
24374 		error = EINVAL;
24375 		break;
24376 	case TCP_RACK_MBUF_QUEUE:
24377 		/* Now do we use the LRO mbuf-queue feature */
24378 		optval = rack->r_mbuf_queue;
24379 		break;
24380 	case RACK_CSPR_IS_FCC:
24381 		optval = rack->cspr_is_fcc;
24382 		break;
24383 	case TCP_TIMELY_DYN_ADJ:
24384 		optval = rack->rc_gp_dyn_mul;
24385 		break;
24386 	case TCP_BBR_IWINTSO:
24387 		error = EINVAL;
24388 		break;
24389 	case TCP_RACK_TLP_REDUCE:
24390 		/* RACK TLP cwnd reduction (bool) */
24391 		optval = rack->r_ctl.rc_tlp_cwnd_reduce;
24392 		break;
24393 	case TCP_BBR_RACK_INIT_RATE:
24394 		val = rack->r_ctl.init_rate;
24395 		/* convert to kbits per sec */
24396 		val *= 8;
24397 		val /= 1000;
24398 		optval = (uint32_t)val;
24399 		break;
24400 	case TCP_RACK_FORCE_MSEG:
24401 		optval = rack->rc_force_max_seg;
24402 		break;
24403 	case TCP_RACK_PACE_MIN_SEG:
24404 		optval = rack->r_ctl.rc_user_set_min_segs;
24405 		break;
24406 	case TCP_RACK_PACE_MAX_SEG:
24407 		/* Max segments in a pace */
24408 		optval = rack->rc_user_set_max_segs;
24409 		break;
24410 	case TCP_RACK_PACE_ALWAYS:
24411 		/* Use the always pace method */
24412 		optval = rack->rc_always_pace;
24413 		break;
24414 	case TCP_RACK_PRR_SENDALOT:
24415 		/* Allow PRR to send more than one seg */
24416 		optval = rack->r_ctl.rc_prr_sendalot;
24417 		break;
24418 	case TCP_RACK_MIN_TO:
24419 		/* Minimum time between rack t-o's in ms */
24420 		optval = rack->r_ctl.rc_min_to;
24421 		break;
24422 	case TCP_RACK_SPLIT_LIMIT:
24423 		optval = rack->r_ctl.rc_split_limit;
24424 		break;
24425 	case TCP_RACK_EARLY_SEG:
24426 		/* If early recovery max segments */
24427 		optval = rack->r_ctl.rc_early_recovery_segs;
24428 		break;
24429 	case TCP_RACK_REORD_THRESH:
24430 		/* RACK reorder threshold (shift amount) */
24431 		optval = rack->r_ctl.rc_reorder_shift;
24432 		break;
24433 	case TCP_SS_EEXIT:
24434 		if (rack->r_ctl.gp_rnd_thresh) {
24435 			uint32_t v;
24436 
24437 			v = rack->r_ctl.gp_gain_req;
24438 			v <<= 17;
24439 			optval = v | (rack->r_ctl.gp_rnd_thresh & 0xff);
24440 			if (rack->r_ctl.gate_to_fs == 1)
24441 				optval |= 0x10000;
24442 		} else
24443 			optval = 0;
24444 		break;
24445 	case TCP_RACK_REORD_FADE:
24446 		/* Does reordering fade after ms time */
24447 		optval = rack->r_ctl.rc_reorder_fade;
24448 		break;
24449 	case TCP_BBR_USE_RACK_RR:
24450 		/* Do we use the rack cheat for rxt */
24451 		optval = rack->use_rack_rr;
24452 		break;
24453 	case TCP_RACK_RR_CONF:
24454 		optval = rack->r_rr_config;
24455 		break;
24456 	case TCP_HDWR_RATE_CAP:
24457 		optval = rack->r_rack_hw_rate_caps;
24458 		break;
24459 	case TCP_BBR_HDWR_PACE:
24460 		optval = rack->rack_hdw_pace_ena;
24461 		break;
24462 	case TCP_RACK_TLP_THRESH:
24463 		/* RACK TLP theshold i.e. srtt+(srtt/N) */
24464 		optval = rack->r_ctl.rc_tlp_threshold;
24465 		break;
24466 	case TCP_RACK_PKT_DELAY:
24467 		/* RACK added ms i.e. rack-rtt + reord + N */
24468 		optval = rack->r_ctl.rc_pkt_delay;
24469 		break;
24470 	case TCP_RACK_TLP_USE:
24471 		optval = rack->rack_tlp_threshold_use;
24472 		break;
24473 	case TCP_PACING_DND:
24474 		optval = rack->rc_pace_dnd;
24475 		break;
24476 	case TCP_RACK_PACE_RATE_CA:
24477 		optval = rack->r_ctl.rc_fixed_pacing_rate_ca;
24478 		break;
24479 	case TCP_RACK_PACE_RATE_SS:
24480 		optval = rack->r_ctl.rc_fixed_pacing_rate_ss;
24481 		break;
24482 	case TCP_RACK_PACE_RATE_REC:
24483 		optval = rack->r_ctl.rc_fixed_pacing_rate_rec;
24484 		break;
24485 	case TCP_DGP_UPPER_BOUNDS:
24486 		optval = rack->r_ctl.rack_per_upper_bound_ss;
24487 		optval <<= 16;
24488 		optval |= rack->r_ctl.rack_per_upper_bound_ca;
24489 		break;
24490 	case TCP_RACK_GP_INCREASE_SS:
24491 		optval = rack->r_ctl.rack_per_of_gp_ca;
24492 		break;
24493 	case TCP_RACK_GP_INCREASE_CA:
24494 		optval = rack->r_ctl.rack_per_of_gp_ss;
24495 		break;
24496 	case TCP_RACK_PACING_DIVISOR:
24497 		optval = rack->r_ctl.pace_len_divisor;
24498 		break;
24499 	case TCP_BBR_RACK_RTT_USE:
24500 		optval = rack->r_ctl.rc_rate_sample_method;
24501 		break;
24502 	case TCP_DELACK:
24503 		optval = tp->t_delayed_ack;
24504 		break;
24505 	case TCP_DATA_AFTER_CLOSE:
24506 		optval = rack->rc_allow_data_af_clo;
24507 		break;
24508 	case TCP_SHARED_CWND_TIME_LIMIT:
24509 		optval = rack->r_limit_scw;
24510 		break;
24511 	case TCP_HONOR_HPTS_MIN:
24512 		if (rack->r_use_hpts_min)
24513 			optval = rack->r_ctl.max_reduction;
24514 		else
24515 			optval = 0;
24516 		break;
24517 	case TCP_REC_IS_DYN:
24518 		optval = rack->rc_gp_no_rec_chg;
24519 		break;
24520 	case TCP_NO_TIMELY:
24521 		optval = rack->rc_skip_timely;
24522 		break;
24523 	case TCP_RACK_TIMER_SLOP:
24524 		optval = rack->r_ctl.timer_slop;
24525 		break;
24526 	default:
24527 		return (tcp_default_ctloutput(tp, sopt));
24528 		break;
24529 	}
24530 	INP_WUNLOCK(inp);
24531 	if (error == 0) {
24532 		if ((sopt->sopt_name == TCP_PACING_RATE_CAP) ||
24533 		    (sopt->sopt_name == TCP_FILLCW_RATE_CAP))
24534 			error = sooptcopyout(sopt, &loptval, sizeof loptval);
24535 		else
24536 			error = sooptcopyout(sopt, &optval, sizeof optval);
24537 	}
24538 	return (error);
24539 }
24540 
24541 static int
24542 rack_ctloutput(struct tcpcb *tp, struct sockopt *sopt)
24543 {
24544 	if (sopt->sopt_dir == SOPT_SET) {
24545 		return (rack_set_sockopt(tp, sopt));
24546 	} else if (sopt->sopt_dir == SOPT_GET) {
24547 		return (rack_get_sockopt(tp, sopt));
24548 	} else {
24549 		panic("%s: sopt_dir $%d", __func__, sopt->sopt_dir);
24550 	}
24551 }
24552 
24553 static const char *rack_stack_names[] = {
24554 	__XSTRING(STACKNAME),
24555 #ifdef STACKALIAS
24556 	__XSTRING(STACKALIAS),
24557 #endif
24558 };
24559 
24560 static int
24561 rack_ctor(void *mem, int32_t size, void *arg, int32_t how)
24562 {
24563 	memset(mem, 0, size);
24564 	return (0);
24565 }
24566 
24567 static void
24568 rack_dtor(void *mem, int32_t size, void *arg)
24569 {
24570 
24571 }
24572 
24573 static bool rack_mod_inited = false;
24574 
24575 static int
24576 tcp_addrack(module_t mod, int32_t type, void *data)
24577 {
24578 	int32_t err = 0;
24579 	int num_stacks;
24580 
24581 	switch (type) {
24582 	case MOD_LOAD:
24583 		rack_zone = uma_zcreate(__XSTRING(MODNAME) "_map",
24584 		    sizeof(struct rack_sendmap),
24585 		    rack_ctor, rack_dtor, NULL, NULL, UMA_ALIGN_PTR, 0);
24586 
24587 		rack_pcb_zone = uma_zcreate(__XSTRING(MODNAME) "_pcb",
24588 		    sizeof(struct tcp_rack),
24589 		    rack_ctor, NULL, NULL, NULL, UMA_ALIGN_CACHE, 0);
24590 
24591 		sysctl_ctx_init(&rack_sysctl_ctx);
24592 		rack_sysctl_root = SYSCTL_ADD_NODE(&rack_sysctl_ctx,
24593 		    SYSCTL_STATIC_CHILDREN(_net_inet_tcp),
24594 		    OID_AUTO,
24595 #ifdef STACKALIAS
24596 		    __XSTRING(STACKALIAS),
24597 #else
24598 		    __XSTRING(STACKNAME),
24599 #endif
24600 		    CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
24601 		    "");
24602 		if (rack_sysctl_root == NULL) {
24603 			printf("Failed to add sysctl node\n");
24604 			err = EFAULT;
24605 			goto free_uma;
24606 		}
24607 		rack_init_sysctls();
24608 		num_stacks = nitems(rack_stack_names);
24609 		err = register_tcp_functions_as_names(&__tcp_rack, M_WAITOK,
24610 		    rack_stack_names, &num_stacks);
24611 		if (err) {
24612 			printf("Failed to register %s stack name for "
24613 			    "%s module\n", rack_stack_names[num_stacks],
24614 			    __XSTRING(MODNAME));
24615 			sysctl_ctx_free(&rack_sysctl_ctx);
24616 free_uma:
24617 			uma_zdestroy(rack_zone);
24618 			uma_zdestroy(rack_pcb_zone);
24619 			rack_counter_destroy();
24620 			printf("Failed to register rack module -- err:%d\n", err);
24621 			return (err);
24622 		}
24623 		tcp_lro_reg_mbufq();
24624 		rack_mod_inited = true;
24625 		break;
24626 	case MOD_QUIESCE:
24627 		err = deregister_tcp_functions(&__tcp_rack, true, false);
24628 		break;
24629 	case MOD_UNLOAD:
24630 		err = deregister_tcp_functions(&__tcp_rack, false, true);
24631 		if (err == EBUSY)
24632 			break;
24633 		if (rack_mod_inited) {
24634 			uma_zdestroy(rack_zone);
24635 			uma_zdestroy(rack_pcb_zone);
24636 			sysctl_ctx_free(&rack_sysctl_ctx);
24637 			rack_counter_destroy();
24638 			rack_mod_inited = false;
24639 		}
24640 		tcp_lro_dereg_mbufq();
24641 		err = 0;
24642 		break;
24643 	default:
24644 		return (EOPNOTSUPP);
24645 	}
24646 	return (err);
24647 }
24648 
24649 static moduledata_t tcp_rack = {
24650 	.name = __XSTRING(MODNAME),
24651 	.evhand = tcp_addrack,
24652 	.priv = 0
24653 };
24654 
24655 MODULE_VERSION(MODNAME, 1);
24656 DECLARE_MODULE(MODNAME, tcp_rack, SI_SUB_PROTO_DOMAIN, SI_ORDER_ANY);
24657 MODULE_DEPEND(MODNAME, tcphpts, 1, 1, 1);
24658 
24659 #endif /* #if !defined(INET) && !defined(INET6) */
24660