xref: /freebsd/sys/netinet/tcp_stacks/rack.c (revision dba226d43d11cd29ab8ee2fd05b1472562ae09f5) 
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 __FBSDID("$FreeBSD$");
29 
30 #include "opt_inet.h"
31 #include "opt_inet6.h"
32 #include "opt_ipsec.h"
33 #include "opt_tcpdebug.h"
34 #include "opt_ratelimit.h"
35 #include "opt_kern_tls.h"
36 #include <sys/param.h>
37 #include <sys/arb.h>
38 #include <sys/module.h>
39 #include <sys/kernel.h>
40 #ifdef TCP_HHOOK
41 #include <sys/hhook.h>
42 #endif
43 #include <sys/lock.h>
44 #include <sys/malloc.h>
45 #include <sys/lock.h>
46 #include <sys/mutex.h>
47 #include <sys/mbuf.h>
48 #include <sys/proc.h>		/* for proc0 declaration */
49 #include <sys/socket.h>
50 #include <sys/socketvar.h>
51 #include <sys/sysctl.h>
52 #include <sys/systm.h>
53 #ifdef STATS
54 #include <sys/qmath.h>
55 #include <sys/tree.h>
56 #include <sys/stats.h> /* Must come after qmath.h and tree.h */
57 #else
58 #include <sys/tree.h>
59 #endif
60 #include <sys/refcount.h>
61 #include <sys/queue.h>
62 #include <sys/tim_filter.h>
63 #include <sys/smp.h>
64 #include <sys/kthread.h>
65 #include <sys/kern_prefetch.h>
66 #include <sys/protosw.h>
67 #ifdef TCP_ACCOUNTING
68 #include <sys/sched.h>
69 #include <machine/cpu.h>
70 #endif
71 #include <vm/uma.h>
72 
73 #include <net/route.h>
74 #include <net/route/nhop.h>
75 #include <net/vnet.h>
76 
77 #define TCPSTATES		/* for logging */
78 
79 #include <netinet/in.h>
80 #include <netinet/in_kdtrace.h>
81 #include <netinet/in_pcb.h>
82 #include <netinet/ip.h>
83 #include <netinet/ip_icmp.h>	/* required for icmp_var.h */
84 #include <netinet/icmp_var.h>	/* for ICMP_BANDLIM */
85 #include <netinet/ip_var.h>
86 #include <netinet/ip6.h>
87 #include <netinet6/in6_pcb.h>
88 #include <netinet6/ip6_var.h>
89 #include <netinet/tcp.h>
90 #define	TCPOUTFLAGS
91 #include <netinet/tcp_fsm.h>
92 #include <netinet/tcp_log_buf.h>
93 #include <netinet/tcp_seq.h>
94 #include <netinet/tcp_timer.h>
95 #include <netinet/tcp_var.h>
96 #include <netinet/tcp_syncache.h>
97 #include <netinet/tcp_hpts.h>
98 #include <netinet/tcp_ratelimit.h>
99 #include <netinet/tcp_accounting.h>
100 #include <netinet/tcpip.h>
101 #include <netinet/cc/cc.h>
102 #include <netinet/cc/cc_newreno.h>
103 #include <netinet/tcp_fastopen.h>
104 #include <netinet/tcp_lro.h>
105 #ifdef NETFLIX_SHARED_CWND
106 #include <netinet/tcp_shared_cwnd.h>
107 #endif
108 #ifdef TCPDEBUG
109 #include <netinet/tcp_debug.h>
110 #endif				/* TCPDEBUG */
111 #ifdef TCP_OFFLOAD
112 #include <netinet/tcp_offload.h>
113 #endif
114 #ifdef INET6
115 #include <netinet6/tcp6_var.h>
116 #endif
117 #include <netinet/tcp_ecn.h>
118 
119 #include <netipsec/ipsec_support.h>
120 
121 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
122 #include <netipsec/ipsec.h>
123 #include <netipsec/ipsec6.h>
124 #endif				/* IPSEC */
125 
126 #include <netinet/udp.h>
127 #include <netinet/udp_var.h>
128 #include <machine/in_cksum.h>
129 
130 #ifdef MAC
131 #include <security/mac/mac_framework.h>
132 #endif
133 #include "sack_filter.h"
134 #include "tcp_rack.h"
135 #include "rack_bbr_common.h"
136 
137 uma_zone_t rack_zone;
138 uma_zone_t rack_pcb_zone;
139 
140 #ifndef TICKS2SBT
141 #define	TICKS2SBT(__t)	(tick_sbt * ((sbintime_t)(__t)))
142 #endif
143 
144 VNET_DECLARE(uint32_t, newreno_beta);
145 VNET_DECLARE(uint32_t, newreno_beta_ecn);
146 #define V_newreno_beta VNET(newreno_beta)
147 #define V_newreno_beta_ecn VNET(newreno_beta_ecn)
148 
149 
150 MALLOC_DEFINE(M_TCPFSB, "tcp_fsb", "TCP fast send block");
151 MALLOC_DEFINE(M_TCPDO, "tcp_do", "TCP deferred options");
152 
153 struct sysctl_ctx_list rack_sysctl_ctx;
154 struct sysctl_oid *rack_sysctl_root;
155 
156 #define CUM_ACKED 1
157 #define SACKED 2
158 
159 /*
160  * The RACK module incorporates a number of
161  * TCP ideas that have been put out into the IETF
162  * over the last few years:
163  * - Matt Mathis's Rate Halving which slowly drops
164  *    the congestion window so that the ack clock can
165  *    be maintained during a recovery.
166  * - Yuchung Cheng's RACK TCP (for which its named) that
167  *    will stop us using the number of dup acks and instead
168  *    use time as the gage of when we retransmit.
169  * - Reorder Detection of RFC4737 and the Tail-Loss probe draft
170  *    of Dukkipati et.al.
171  * RACK depends on SACK, so if an endpoint arrives that
172  * cannot do SACK the state machine below will shuttle the
173  * connection back to using the "default" TCP stack that is
174  * in FreeBSD.
175  *
176  * To implement RACK the original TCP stack was first decomposed
177  * into a functional state machine with individual states
178  * for each of the possible TCP connection states. The do_segment
179  * functions role in life is to mandate the connection supports SACK
180  * initially and then assure that the RACK state matches the conenction
181  * state before calling the states do_segment function. Each
182  * state is simplified due to the fact that the original do_segment
183  * has been decomposed and we *know* what state we are in (no
184  * switches on the state) and all tests for SACK are gone. This
185  * greatly simplifies what each state does.
186  *
187  * TCP output is also over-written with a new version since it
188  * must maintain the new rack scoreboard.
189  *
190  */
191 static int32_t rack_tlp_thresh = 1;
192 static int32_t rack_tlp_limit = 2;	/* No more than 2 TLPs w-out new data */
193 static int32_t rack_tlp_use_greater = 1;
194 static int32_t rack_reorder_thresh = 2;
195 static int32_t rack_reorder_fade = 60000000;	/* 0 - never fade, def 60,000,000
196 						 * - 60 seconds */
197 static uint8_t rack_req_measurements = 1;
198 /* Attack threshold detections */
199 static uint32_t rack_highest_sack_thresh_seen = 0;
200 static uint32_t rack_highest_move_thresh_seen = 0;
201 static int32_t rack_enable_hw_pacing = 0; /* Due to CCSP keep it off by default */
202 static int32_t rack_hw_pace_extra_slots = 2;	/* 2 extra MSS time betweens */
203 static int32_t rack_hw_rate_caps = 1; /* 1; */
204 static int32_t rack_hw_rate_min = 0; /* 1500000;*/
205 static int32_t rack_hw_rate_to_low = 0; /* 1200000; */
206 static int32_t rack_hw_up_only = 1;
207 static int32_t rack_stats_gets_ms_rtt = 1;
208 static int32_t rack_prr_addbackmax = 2;
209 static int32_t rack_do_hystart = 0;
210 static int32_t rack_apply_rtt_with_reduced_conf = 0;
211 
212 static int32_t rack_pkt_delay = 1000;
213 static int32_t rack_send_a_lot_in_prr = 1;
214 static int32_t rack_min_to = 1000;	/* Number of microsecond  min timeout */
215 static int32_t rack_verbose_logging = 0;
216 static int32_t rack_ignore_data_after_close = 1;
217 static int32_t rack_enable_shared_cwnd = 1;
218 static int32_t rack_use_cmp_acks = 1;
219 static int32_t rack_use_fsb = 1;
220 static int32_t rack_use_rfo = 1;
221 static int32_t rack_use_rsm_rfo = 1;
222 static int32_t rack_max_abc_post_recovery = 2;
223 static int32_t rack_client_low_buf = 0;
224 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 */
225 #ifdef TCP_ACCOUNTING
226 static int32_t rack_tcp_accounting = 0;
227 #endif
228 static int32_t rack_limits_scwnd = 1;
229 static int32_t rack_enable_mqueue_for_nonpaced = 0;
230 static int32_t rack_disable_prr = 0;
231 static int32_t use_rack_rr = 1;
232 static int32_t rack_non_rxt_use_cr = 0; /* does a non-rxt in recovery use the configured rate (ss/ca)? */
233 static int32_t rack_persist_min = 250000;	/* 250usec */
234 static int32_t rack_persist_max = 2000000;	/* 2 Second in usec's */
235 static int32_t rack_sack_not_required = 1;	/* set to one to allow non-sack to use rack */
236 static int32_t rack_default_init_window = 0;	/* Use system default */
237 static int32_t rack_limit_time_with_srtt = 0;
238 static int32_t rack_autosndbuf_inc = 20;	/* In percentage form */
239 static int32_t rack_enobuf_hw_boost_mult = 2;	/* How many times the hw rate we boost slot using time_between */
240 static int32_t rack_enobuf_hw_max = 12000;	/* 12 ms in usecs */
241 static int32_t rack_enobuf_hw_min = 10000;	/* 10 ms in usecs */
242 static int32_t rack_hw_rwnd_factor = 2;		/* How many max_segs the rwnd must be before we hold off sending */
243 
244 /*
245  * Currently regular tcp has a rto_min of 30ms
246  * the backoff goes 12 times so that ends up
247  * being a total of 122.850 seconds before a
248  * connection is killed.
249  */
250 static uint32_t rack_def_data_window = 20;
251 static uint32_t rack_goal_bdp = 2;
252 static uint32_t rack_min_srtts = 1;
253 static uint32_t rack_min_measure_usec = 0;
254 static int32_t rack_tlp_min = 10000;	/* 10ms */
255 static int32_t rack_rto_min = 30000;	/* 30,000 usec same as main freebsd */
256 static int32_t rack_rto_max = 4000000;	/* 4 seconds in usec's */
257 static const int32_t rack_free_cache = 2;
258 static int32_t rack_hptsi_segments = 40;
259 static int32_t rack_rate_sample_method = USE_RTT_LOW;
260 static int32_t rack_pace_every_seg = 0;
261 static int32_t rack_delayed_ack_time = 40000;	/* 40ms in usecs */
262 static int32_t rack_slot_reduction = 4;
263 static int32_t rack_wma_divisor = 8;		/* For WMA calculation */
264 static int32_t rack_cwnd_block_ends_measure = 0;
265 static int32_t rack_rwnd_block_ends_measure = 0;
266 static int32_t rack_def_profile = 0;
267 
268 static int32_t rack_lower_cwnd_at_tlp = 0;
269 static int32_t rack_limited_retran = 0;
270 static int32_t rack_always_send_oldest = 0;
271 static int32_t rack_tlp_threshold_use = TLP_USE_TWO_ONE;
272 
273 static uint16_t rack_per_of_gp_ss = 250;	/* 250 % slow-start */
274 static uint16_t rack_per_of_gp_ca = 200;	/* 200 % congestion-avoidance */
275 static uint16_t rack_per_of_gp_rec = 200;	/* 200 % of bw */
276 
277 /* Probertt */
278 static uint16_t rack_per_of_gp_probertt = 60;	/* 60% of bw */
279 static uint16_t rack_per_of_gp_lowthresh = 40;	/* 40% is bottom */
280 static uint16_t rack_per_of_gp_probertt_reduce = 10; /* 10% reduction */
281 static uint16_t rack_atexit_prtt_hbp = 130;	/* Clamp to 130% on exit prtt if highly buffered path */
282 static uint16_t rack_atexit_prtt = 130;	/* Clamp to 100% on exit prtt if non highly buffered path */
283 
284 static uint32_t rack_max_drain_wait = 2;	/* How man gp srtt's before we give up draining */
285 static uint32_t rack_must_drain = 1;		/* How many GP srtt's we *must* wait */
286 static uint32_t rack_probertt_use_min_rtt_entry = 1;	/* Use the min to calculate the goal else gp_srtt */
287 static uint32_t rack_probertt_use_min_rtt_exit = 0;
288 static uint32_t rack_probe_rtt_sets_cwnd = 0;
289 static uint32_t rack_probe_rtt_safety_val = 2000000;	/* No more than 2 sec in probe-rtt */
290 static uint32_t rack_time_between_probertt = 9600000;	/* 9.6 sec in usecs */
291 static uint32_t rack_probertt_gpsrtt_cnt_mul = 0;	/* How many srtt periods does probe-rtt last top fraction */
292 static uint32_t rack_probertt_gpsrtt_cnt_div = 0;	/* How many srtt periods does probe-rtt last bottom fraction */
293 static uint32_t rack_min_probertt_hold = 40000;		/* Equal to delayed ack time */
294 static uint32_t rack_probertt_filter_life = 10000000;
295 static uint32_t rack_probertt_lower_within = 10;
296 static uint32_t rack_min_rtt_movement = 250000;	/* Must move at least 250ms (in microseconds)  to count as a lowering */
297 static int32_t rack_pace_one_seg = 0;		/* Shall we pace for less than 1.4Meg 1MSS at a time */
298 static int32_t rack_probertt_clear_is = 1;
299 static int32_t rack_max_drain_hbp = 1;		/* Extra drain times gpsrtt for highly buffered paths */
300 static int32_t rack_hbp_thresh = 3;		/* what is the divisor max_rtt/min_rtt to decided a hbp */
301 
302 /* Part of pacing */
303 static int32_t rack_max_per_above = 30;		/* When we go to increment stop if above 100+this% */
304 
305 /* Timely information */
306 /* Combine these two gives the range of 'no change' to bw */
307 /* ie the up/down provide the upper and lower bound */
308 static int32_t rack_gp_per_bw_mul_up = 2;	/* 2% */
309 static int32_t rack_gp_per_bw_mul_down = 4;	/* 4% */
310 static int32_t rack_gp_rtt_maxmul = 3;		/* 3 x maxmin */
311 static int32_t rack_gp_rtt_minmul = 1;		/* minrtt + (minrtt/mindiv) is lower rtt */
312 static int32_t rack_gp_rtt_mindiv = 4;		/* minrtt + (minrtt * minmul/mindiv) is lower rtt */
313 static int32_t rack_gp_decrease_per = 20;	/* 20% decrease in multiplier */
314 static int32_t rack_gp_increase_per = 2;	/* 2% increase in multiplier */
315 static int32_t rack_per_lower_bound = 50;	/* Don't allow to drop below this multiplier */
316 static int32_t rack_per_upper_bound_ss = 0;	/* Don't allow SS to grow above this */
317 static int32_t rack_per_upper_bound_ca = 0;	/* Don't allow CA to grow above this */
318 static int32_t rack_do_dyn_mul = 0;		/* Are the rack gp multipliers dynamic */
319 static int32_t rack_gp_no_rec_chg = 1;		/* Prohibit recovery from reducing it's multiplier */
320 static int32_t rack_timely_dec_clear = 6;	/* Do we clear decrement count at a value (6)? */
321 static int32_t rack_timely_max_push_rise = 3;	/* One round of pushing */
322 static int32_t rack_timely_max_push_drop = 3;	/* Three round of pushing */
323 static int32_t rack_timely_min_segs = 4;	/* 4 segment minimum */
324 static int32_t rack_use_max_for_nobackoff = 0;
325 static int32_t rack_timely_int_timely_only = 0;	/* do interim timely's only use the timely algo (no b/w changes)? */
326 static int32_t rack_timely_no_stopping = 0;
327 static int32_t rack_down_raise_thresh = 100;
328 static int32_t rack_req_segs = 1;
329 static uint64_t rack_bw_rate_cap = 0;
330 static uint32_t rack_trace_point_config = 0;
331 static uint32_t rack_trace_point_bb_mode = 4;
332 static int32_t rack_trace_point_count = 0;
333 
334 
335 /* Weird delayed ack mode */
336 static int32_t rack_use_imac_dack = 0;
337 /* Rack specific counters */
338 counter_u64_t rack_saw_enobuf;
339 counter_u64_t rack_saw_enobuf_hw;
340 counter_u64_t rack_saw_enetunreach;
341 counter_u64_t rack_persists_sends;
342 counter_u64_t rack_persists_acks;
343 counter_u64_t rack_persists_loss;
344 counter_u64_t rack_persists_lost_ends;
345 #ifdef INVARIANTS
346 counter_u64_t rack_adjust_map_bw;
347 #endif
348 /* Tail loss probe counters */
349 counter_u64_t rack_tlp_tot;
350 counter_u64_t rack_tlp_newdata;
351 counter_u64_t rack_tlp_retran;
352 counter_u64_t rack_tlp_retran_bytes;
353 counter_u64_t rack_to_tot;
354 counter_u64_t rack_hot_alloc;
355 counter_u64_t rack_to_alloc;
356 counter_u64_t rack_to_alloc_hard;
357 counter_u64_t rack_to_alloc_emerg;
358 counter_u64_t rack_to_alloc_limited;
359 counter_u64_t rack_alloc_limited_conns;
360 counter_u64_t rack_split_limited;
361 
362 counter_u64_t rack_multi_single_eq;
363 counter_u64_t rack_proc_non_comp_ack;
364 
365 counter_u64_t rack_fto_send;
366 counter_u64_t rack_fto_rsm_send;
367 counter_u64_t rack_nfto_resend;
368 counter_u64_t rack_non_fto_send;
369 counter_u64_t rack_extended_rfo;
370 
371 counter_u64_t rack_sack_proc_all;
372 counter_u64_t rack_sack_proc_short;
373 counter_u64_t rack_sack_proc_restart;
374 counter_u64_t rack_sack_attacks_detected;
375 counter_u64_t rack_sack_attacks_reversed;
376 counter_u64_t rack_sack_used_next_merge;
377 counter_u64_t rack_sack_splits;
378 counter_u64_t rack_sack_used_prev_merge;
379 counter_u64_t rack_sack_skipped_acked;
380 counter_u64_t rack_ack_total;
381 counter_u64_t rack_express_sack;
382 counter_u64_t rack_sack_total;
383 counter_u64_t rack_move_none;
384 counter_u64_t rack_move_some;
385 
386 counter_u64_t rack_input_idle_reduces;
387 counter_u64_t rack_collapsed_win;
388 counter_u64_t rack_collapsed_win_seen;
389 counter_u64_t rack_collapsed_win_rxt;
390 counter_u64_t rack_collapsed_win_rxt_bytes;
391 counter_u64_t rack_try_scwnd;
392 counter_u64_t rack_hw_pace_init_fail;
393 counter_u64_t rack_hw_pace_lost;
394 
395 counter_u64_t rack_out_size[TCP_MSS_ACCT_SIZE];
396 counter_u64_t rack_opts_arry[RACK_OPTS_SIZE];
397 
398 
399 #define	RACK_REXMTVAL(tp) max(rack_rto_min, ((tp)->t_srtt + ((tp)->t_rttvar << 2)))
400 
401 #define	RACK_TCPT_RANGESET(tv, value, tvmin, tvmax, slop) do {	\
402 	(tv) = (value) + slop;	 \
403 	if ((u_long)(tv) < (u_long)(tvmin)) \
404 		(tv) = (tvmin); \
405 	if ((u_long)(tv) > (u_long)(tvmax)) \
406 		(tv) = (tvmax); \
407 } while (0)
408 
409 static void
410 rack_log_progress_event(struct tcp_rack *rack, struct tcpcb *tp, uint32_t tick,  int event, int line);
411 
412 static int
413 rack_process_ack(struct mbuf *m, struct tcphdr *th,
414     struct socket *so, struct tcpcb *tp, struct tcpopt *to,
415     uint32_t tiwin, int32_t tlen, int32_t * ofia, int32_t thflags, int32_t * ret_val);
416 static int
417 rack_process_data(struct mbuf *m, struct tcphdr *th,
418     struct socket *so, struct tcpcb *tp, int32_t drop_hdrlen, int32_t tlen,
419     uint32_t tiwin, int32_t thflags, int32_t nxt_pkt);
420 static void
421 rack_ack_received(struct tcpcb *tp, struct tcp_rack *rack,
422    uint32_t th_ack, uint16_t nsegs, uint16_t type, int32_t recovery);
423 static struct rack_sendmap *rack_alloc(struct tcp_rack *rack);
424 static struct rack_sendmap *rack_alloc_limit(struct tcp_rack *rack,
425     uint8_t limit_type);
426 static struct rack_sendmap *
427 rack_check_recovery_mode(struct tcpcb *tp,
428     uint32_t tsused);
429 static void
430 rack_cong_signal(struct tcpcb *tp,
431 		 uint32_t type, uint32_t ack, int );
432 static void rack_counter_destroy(void);
433 static int
434 rack_ctloutput(struct inpcb *inp, struct sockopt *sopt);
435 static int32_t rack_ctor(void *mem, int32_t size, void *arg, int32_t how);
436 static void
437 rack_set_pace_segments(struct tcpcb *tp, struct tcp_rack *rack, uint32_t line, uint64_t *fill_override);
438 static void
439 rack_do_segment(struct mbuf *m, struct tcphdr *th,
440     struct socket *so, struct tcpcb *tp, int32_t drop_hdrlen, int32_t tlen,
441     uint8_t iptos);
442 static void rack_dtor(void *mem, int32_t size, void *arg);
443 static void
444 rack_log_alt_to_to_cancel(struct tcp_rack *rack,
445     uint32_t flex1, uint32_t flex2,
446     uint32_t flex3, uint32_t flex4,
447     uint32_t flex5, uint32_t flex6,
448     uint16_t flex7, uint8_t mod);
449 
450 static void
451 rack_log_pacing_delay_calc(struct tcp_rack *rack, uint32_t len, uint32_t slot,
452    uint64_t bw_est, uint64_t bw, uint64_t len_time, int method, int line,
453    struct rack_sendmap *rsm, uint8_t quality);
454 static struct rack_sendmap *
455 rack_find_high_nonack(struct tcp_rack *rack,
456     struct rack_sendmap *rsm);
457 static struct rack_sendmap *rack_find_lowest_rsm(struct tcp_rack *rack);
458 static void rack_free(struct tcp_rack *rack, struct rack_sendmap *rsm);
459 static void rack_fini(struct tcpcb *tp, int32_t tcb_is_purged);
460 static int rack_get_sockopt(struct inpcb *inp, struct sockopt *sopt);
461 static void
462 rack_do_goodput_measurement(struct tcpcb *tp, struct tcp_rack *rack,
463 			    tcp_seq th_ack, int line, uint8_t quality);
464 static uint32_t
465 rack_get_pacing_len(struct tcp_rack *rack, uint64_t bw, uint32_t mss);
466 static int32_t rack_handoff_ok(struct tcpcb *tp);
467 static int32_t rack_init(struct tcpcb *tp);
468 static void rack_init_sysctls(void);
469 static void
470 rack_log_ack(struct tcpcb *tp, struct tcpopt *to,
471     struct tcphdr *th, int entered_rec, int dup_ack_struck);
472 static void
473 rack_log_output(struct tcpcb *tp, struct tcpopt *to, int32_t len,
474     uint32_t seq_out, uint16_t th_flags, int32_t err, uint64_t ts,
475     struct rack_sendmap *hintrsm, uint16_t add_flags, struct mbuf *s_mb, uint32_t s_moff, int hw_tls);
476 
477 static void
478 rack_log_sack_passed(struct tcpcb *tp, struct tcp_rack *rack,
479     struct rack_sendmap *rsm);
480 static void rack_log_to_event(struct tcp_rack *rack, int32_t to_num, struct rack_sendmap *rsm);
481 static int32_t rack_output(struct tcpcb *tp);
482 
483 static uint32_t
484 rack_proc_sack_blk(struct tcpcb *tp, struct tcp_rack *rack,
485     struct sackblk *sack, struct tcpopt *to, struct rack_sendmap **prsm,
486     uint32_t cts, int *moved_two);
487 static void rack_post_recovery(struct tcpcb *tp, uint32_t th_seq);
488 static void rack_remxt_tmr(struct tcpcb *tp);
489 static int rack_set_sockopt(struct inpcb *inp, struct sockopt *sopt);
490 static void rack_set_state(struct tcpcb *tp, struct tcp_rack *rack);
491 static int32_t rack_stopall(struct tcpcb *tp);
492 static void
493 rack_timer_activate(struct tcpcb *tp, uint32_t timer_type,
494     uint32_t delta);
495 static int32_t rack_timer_active(struct tcpcb *tp, uint32_t timer_type);
496 static void rack_timer_cancel(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cts, int line);
497 static void rack_timer_stop(struct tcpcb *tp, uint32_t timer_type);
498 static uint32_t
499 rack_update_entry(struct tcpcb *tp, struct tcp_rack *rack,
500     struct rack_sendmap *rsm, uint64_t ts, int32_t * lenp, uint16_t add_flag);
501 static void
502 rack_update_rsm(struct tcpcb *tp, struct tcp_rack *rack,
503     struct rack_sendmap *rsm, uint64_t ts, uint16_t add_flag);
504 static int
505 rack_update_rtt(struct tcpcb *tp, struct tcp_rack *rack,
506     struct rack_sendmap *rsm, struct tcpopt *to, uint32_t cts, int32_t ack_type, tcp_seq th_ack);
507 static int32_t tcp_addrack(module_t mod, int32_t type, void *data);
508 static int
509 rack_do_close_wait(struct mbuf *m, struct tcphdr *th,
510     struct socket *so, struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen,
511     int32_t tlen, uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos);
512 static int
513 rack_do_closing(struct mbuf *m, struct tcphdr *th,
514     struct socket *so, struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen,
515     int32_t tlen, uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos);
516 static int
517 rack_do_established(struct mbuf *m, struct tcphdr *th,
518     struct socket *so, struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen,
519     int32_t tlen, uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos);
520 static int
521 rack_do_fastnewdata(struct mbuf *m, struct tcphdr *th,
522     struct socket *so, struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen,
523     int32_t tlen, uint32_t tiwin, int32_t nxt_pkt, uint8_t iptos);
524 static int
525 rack_do_fin_wait_1(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 static int
529 rack_do_fin_wait_2(struct mbuf *m, struct tcphdr *th,
530     struct socket *so, struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen,
531     int32_t tlen, uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos);
532 static int
533 rack_do_lastack(struct mbuf *m, struct tcphdr *th,
534     struct socket *so, struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen,
535     int32_t tlen, uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos);
536 static int
537 rack_do_syn_recv(struct mbuf *m, struct tcphdr *th,
538     struct socket *so, struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen,
539     int32_t tlen, uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos);
540 static int
541 rack_do_syn_sent(struct mbuf *m, struct tcphdr *th,
542     struct socket *so, struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen,
543     int32_t tlen, uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos);
544 struct rack_sendmap *
545 tcp_rack_output(struct tcpcb *tp, struct tcp_rack *rack,
546     uint32_t tsused);
547 static void tcp_rack_xmit_timer(struct tcp_rack *rack, int32_t rtt,
548     uint32_t len, uint32_t us_tim, int confidence, struct rack_sendmap *rsm, uint16_t rtrcnt);
549 static void
550      tcp_rack_partialack(struct tcpcb *tp);
551 static int
552 rack_set_profile(struct tcp_rack *rack, int prof);
553 static void
554 rack_apply_deferred_options(struct tcp_rack *rack);
555 
556 int32_t rack_clear_counter=0;
557 
558 static inline void
559 rack_trace_point(struct tcp_rack *rack, int num)
560 {
561 	if (((rack_trace_point_config == num)  ||
562 	     (rack_trace_point_config = 0xffffffff)) &&
563 	    (rack_trace_point_bb_mode != 0) &&
564 	    (rack_trace_point_count > 0) &&
565 	    (rack->rc_tp->t_logstate == 0)) {
566 		int res;
567 		res = atomic_fetchadd_int(&rack_trace_point_count, -1);
568 		if (res > 0) {
569 			rack->rc_tp->t_logstate = rack_trace_point_bb_mode;
570 		} else {
571 			/* Loss a race assure its zero now */
572 			rack_trace_point_count = 0;
573 		}
574 	}
575 }
576 
577 static void
578 rack_set_cc_pacing(struct tcp_rack *rack)
579 {
580 	struct sockopt sopt;
581 	struct cc_newreno_opts opt;
582 	struct newreno old, *ptr;
583 	struct tcpcb *tp;
584 	int error;
585 
586 	if (rack->rc_pacing_cc_set)
587 		return;
588 
589 	tp = rack->rc_tp;
590 	if (tp->cc_algo == NULL) {
591 		/* Tcb is leaving */
592 		return;
593 	}
594 	rack->rc_pacing_cc_set = 1;
595 	if (strcmp(tp->cc_algo->name, CCALGONAME_NEWRENO) != 0) {
596 		/* Not new-reno we can't play games with beta! */
597 		goto out;
598 	}
599 	ptr = ((struct newreno *)tp->ccv->cc_data);
600 	if (CC_ALGO(tp)->ctl_output == NULL)  {
601 		/* Huh, why does new_reno no longer have a set function? */
602 		goto out;
603 	}
604 	if (ptr == NULL) {
605 		/* Just the default values */
606 		old.beta = V_newreno_beta_ecn;
607 		old.beta_ecn = V_newreno_beta_ecn;
608 		old.newreno_flags = 0;
609 	} else {
610 		old.beta = ptr->beta;
611 		old.beta_ecn = ptr->beta_ecn;
612 		old.newreno_flags = ptr->newreno_flags;
613 	}
614 	sopt.sopt_valsize = sizeof(struct cc_newreno_opts);
615 	sopt.sopt_dir = SOPT_SET;
616 	opt.name = CC_NEWRENO_BETA;
617 	opt.val = rack->r_ctl.rc_saved_beta.beta;
618 	error = CC_ALGO(tp)->ctl_output(tp->ccv, &sopt, &opt);
619 	if (error)  {
620 		goto out;
621 	}
622 	/*
623 	 * Hack alert we need to set in our newreno_flags
624 	 * so that Abe behavior is also applied.
625 	 */
626 	((struct newreno *)tp->ccv->cc_data)->newreno_flags |= CC_NEWRENO_BETA_ECN_ENABLED;
627 	opt.name = CC_NEWRENO_BETA_ECN;
628 	opt.val = rack->r_ctl.rc_saved_beta.beta_ecn;
629 	error = CC_ALGO(tp)->ctl_output(tp->ccv, &sopt, &opt);
630 	if (error) {
631 		goto out;
632 	}
633 	/* Save off the original values for restoral */
634 	memcpy(&rack->r_ctl.rc_saved_beta, &old, sizeof(struct newreno));
635 out:
636 	if (rack_verbose_logging && (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF)) {
637 		union tcp_log_stackspecific log;
638 		struct timeval tv;
639 
640 		ptr = ((struct newreno *)tp->ccv->cc_data);
641 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
642 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
643 		if (ptr) {
644 			log.u_bbr.flex1 = ptr->beta;
645 			log.u_bbr.flex2 = ptr->beta_ecn;
646 			log.u_bbr.flex3 = ptr->newreno_flags;
647 		}
648 		log.u_bbr.flex4 = rack->r_ctl.rc_saved_beta.beta;
649 		log.u_bbr.flex5 = rack->r_ctl.rc_saved_beta.beta_ecn;
650 		log.u_bbr.flex6 = rack->r_ctl.rc_saved_beta.newreno_flags;
651 		log.u_bbr.flex7 = rack->gp_ready;
652 		log.u_bbr.flex7 <<= 1;
653 		log.u_bbr.flex7 |= rack->use_fixed_rate;
654 		log.u_bbr.flex7 <<= 1;
655 		log.u_bbr.flex7 |= rack->rc_pacing_cc_set;
656 		log.u_bbr.pkts_out = rack->r_ctl.rc_prr_sndcnt;
657 		log.u_bbr.flex8 = 3;
658 		tcp_log_event_(tp, NULL, NULL, NULL, BBR_LOG_CWND, error,
659 			       0, &log, false, NULL, NULL, 0, &tv);
660 	}
661 }
662 
663 static void
664 rack_undo_cc_pacing(struct tcp_rack *rack)
665 {
666 	struct newreno old, *ptr;
667 	struct tcpcb *tp;
668 
669 	if (rack->rc_pacing_cc_set == 0)
670 		return;
671 	tp = rack->rc_tp;
672 	rack->rc_pacing_cc_set = 0;
673 	if (tp->cc_algo == NULL)
674 		/* Tcb is leaving */
675 		return;
676 	if (strcmp(tp->cc_algo->name, CCALGONAME_NEWRENO) != 0) {
677 		/* Not new-reno nothing to do! */
678 		return;
679 	}
680 	ptr = ((struct newreno *)tp->ccv->cc_data);
681 	if (ptr == NULL) {
682 		/*
683 		 * This happens at rack_fini() if the
684 		 * cc module gets freed on us. In that
685 		 * case we loose our "new" settings but
686 		 * thats ok, since the tcb is going away anyway.
687 		 */
688 		return;
689 	}
690 	/* Grab out our set values */
691 	memcpy(&old, ptr, sizeof(struct newreno));
692 	/* Copy back in the original values */
693 	memcpy(ptr, &rack->r_ctl.rc_saved_beta, sizeof(struct newreno));
694 	/* Now save back the values we had set in (for when pacing is restored) */
695 	memcpy(&rack->r_ctl.rc_saved_beta, &old, sizeof(struct newreno));
696 	if (rack_verbose_logging && (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF)) {
697 		union tcp_log_stackspecific log;
698 		struct timeval tv;
699 
700 		ptr = ((struct newreno *)tp->ccv->cc_data);
701 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
702 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
703 		log.u_bbr.flex1 = ptr->beta;
704 		log.u_bbr.flex2 = ptr->beta_ecn;
705 		log.u_bbr.flex3 = ptr->newreno_flags;
706 		log.u_bbr.flex4 = rack->r_ctl.rc_saved_beta.beta;
707 		log.u_bbr.flex5 = rack->r_ctl.rc_saved_beta.beta_ecn;
708 		log.u_bbr.flex6 = rack->r_ctl.rc_saved_beta.newreno_flags;
709 		log.u_bbr.flex7 = rack->gp_ready;
710 		log.u_bbr.flex7 <<= 1;
711 		log.u_bbr.flex7 |= rack->use_fixed_rate;
712 		log.u_bbr.flex7 <<= 1;
713 		log.u_bbr.flex7 |= rack->rc_pacing_cc_set;
714 		log.u_bbr.pkts_out = rack->r_ctl.rc_prr_sndcnt;
715 		log.u_bbr.flex8 = 4;
716 		tcp_log_event_(tp, NULL, NULL, NULL, BBR_LOG_CWND, 0,
717 			       0, &log, false, NULL, NULL, 0, &tv);
718 	}
719 }
720 
721 #ifdef NETFLIX_PEAKRATE
722 static inline void
723 rack_update_peakrate_thr(struct tcpcb *tp)
724 {
725 	/* Keep in mind that t_maxpeakrate is in B/s. */
726 	uint64_t peak;
727 	peak = uqmax((tp->t_maxseg * 2),
728 		     (((uint64_t)tp->t_maxpeakrate * (uint64_t)(tp->t_srtt)) / (uint64_t)HPTS_USEC_IN_SEC));
729 	tp->t_peakrate_thr = (uint32_t)uqmin(peak, UINT32_MAX);
730 }
731 #endif
732 
733 static int
734 sysctl_rack_clear(SYSCTL_HANDLER_ARGS)
735 {
736 	uint32_t stat;
737 	int32_t error;
738 
739 	error = SYSCTL_OUT(req, &rack_clear_counter, sizeof(uint32_t));
740 	if (error || req->newptr == NULL)
741 		return error;
742 
743 	error = SYSCTL_IN(req, &stat, sizeof(uint32_t));
744 	if (error)
745 		return (error);
746 	if (stat == 1) {
747 #ifdef INVARIANTS
748 		printf("Clearing RACK counters\n");
749 #endif
750 		counter_u64_zero(rack_tlp_tot);
751 		counter_u64_zero(rack_tlp_newdata);
752 		counter_u64_zero(rack_tlp_retran);
753 		counter_u64_zero(rack_tlp_retran_bytes);
754 		counter_u64_zero(rack_to_tot);
755 		counter_u64_zero(rack_saw_enobuf);
756 		counter_u64_zero(rack_saw_enobuf_hw);
757 		counter_u64_zero(rack_saw_enetunreach);
758 		counter_u64_zero(rack_persists_sends);
759 		counter_u64_zero(rack_persists_acks);
760 		counter_u64_zero(rack_persists_loss);
761 		counter_u64_zero(rack_persists_lost_ends);
762 #ifdef INVARIANTS
763 		counter_u64_zero(rack_adjust_map_bw);
764 #endif
765 		counter_u64_zero(rack_to_alloc_hard);
766 		counter_u64_zero(rack_to_alloc_emerg);
767 		counter_u64_zero(rack_sack_proc_all);
768 		counter_u64_zero(rack_fto_send);
769 		counter_u64_zero(rack_fto_rsm_send);
770 		counter_u64_zero(rack_extended_rfo);
771 		counter_u64_zero(rack_hw_pace_init_fail);
772 		counter_u64_zero(rack_hw_pace_lost);
773 		counter_u64_zero(rack_non_fto_send);
774 		counter_u64_zero(rack_nfto_resend);
775 		counter_u64_zero(rack_sack_proc_short);
776 		counter_u64_zero(rack_sack_proc_restart);
777 		counter_u64_zero(rack_to_alloc);
778 		counter_u64_zero(rack_to_alloc_limited);
779 		counter_u64_zero(rack_alloc_limited_conns);
780 		counter_u64_zero(rack_split_limited);
781 		counter_u64_zero(rack_multi_single_eq);
782 		counter_u64_zero(rack_proc_non_comp_ack);
783 		counter_u64_zero(rack_sack_attacks_detected);
784 		counter_u64_zero(rack_sack_attacks_reversed);
785 		counter_u64_zero(rack_sack_used_next_merge);
786 		counter_u64_zero(rack_sack_used_prev_merge);
787 		counter_u64_zero(rack_sack_splits);
788 		counter_u64_zero(rack_sack_skipped_acked);
789 		counter_u64_zero(rack_ack_total);
790 		counter_u64_zero(rack_express_sack);
791 		counter_u64_zero(rack_sack_total);
792 		counter_u64_zero(rack_move_none);
793 		counter_u64_zero(rack_move_some);
794 		counter_u64_zero(rack_try_scwnd);
795 		counter_u64_zero(rack_collapsed_win);
796 		counter_u64_zero(rack_collapsed_win_rxt);
797 		counter_u64_zero(rack_collapsed_win_seen);
798 		counter_u64_zero(rack_collapsed_win_rxt_bytes);
799 	}
800 	rack_clear_counter = 0;
801 	return (0);
802 }
803 
804 static void
805 rack_init_sysctls(void)
806 {
807 	struct sysctl_oid *rack_counters;
808 	struct sysctl_oid *rack_attack;
809 	struct sysctl_oid *rack_pacing;
810 	struct sysctl_oid *rack_timely;
811 	struct sysctl_oid *rack_timers;
812 	struct sysctl_oid *rack_tlp;
813 	struct sysctl_oid *rack_misc;
814 	struct sysctl_oid *rack_features;
815 	struct sysctl_oid *rack_measure;
816 	struct sysctl_oid *rack_probertt;
817 	struct sysctl_oid *rack_hw_pacing;
818 	struct sysctl_oid *rack_tracepoint;
819 
820 	rack_attack = SYSCTL_ADD_NODE(&rack_sysctl_ctx,
821 	    SYSCTL_CHILDREN(rack_sysctl_root),
822 	    OID_AUTO,
823 	    "sack_attack",
824 	    CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
825 	    "Rack Sack Attack Counters and Controls");
826 	rack_counters = SYSCTL_ADD_NODE(&rack_sysctl_ctx,
827 	    SYSCTL_CHILDREN(rack_sysctl_root),
828 	    OID_AUTO,
829 	    "stats",
830 	    CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
831 	    "Rack Counters");
832 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
833 	    SYSCTL_CHILDREN(rack_sysctl_root),
834 	    OID_AUTO, "rate_sample_method", CTLFLAG_RW,
835 	    &rack_rate_sample_method , USE_RTT_LOW,
836 	    "What method should we use for rate sampling 0=high, 1=low ");
837 	/* Probe rtt related controls */
838 	rack_probertt = SYSCTL_ADD_NODE(&rack_sysctl_ctx,
839 	    SYSCTL_CHILDREN(rack_sysctl_root),
840 	    OID_AUTO,
841 	    "probertt",
842 	    CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
843 	    "ProbeRTT related Controls");
844 	SYSCTL_ADD_U16(&rack_sysctl_ctx,
845 	    SYSCTL_CHILDREN(rack_probertt),
846 	    OID_AUTO, "exit_per_hpb", CTLFLAG_RW,
847 	    &rack_atexit_prtt_hbp, 130,
848 	    "What percentage above goodput do we clamp CA/SS to at exit on high-BDP path 110%");
849 	SYSCTL_ADD_U16(&rack_sysctl_ctx,
850 	    SYSCTL_CHILDREN(rack_probertt),
851 	    OID_AUTO, "exit_per_nonhpb", CTLFLAG_RW,
852 	    &rack_atexit_prtt, 130,
853 	    "What percentage above goodput do we clamp CA/SS to at exit on a non high-BDP path 100%");
854 	SYSCTL_ADD_U16(&rack_sysctl_ctx,
855 	    SYSCTL_CHILDREN(rack_probertt),
856 	    OID_AUTO, "gp_per_mul", CTLFLAG_RW,
857 	    &rack_per_of_gp_probertt, 60,
858 	    "What percentage of goodput do we pace at in probertt");
859 	SYSCTL_ADD_U16(&rack_sysctl_ctx,
860 	    SYSCTL_CHILDREN(rack_probertt),
861 	    OID_AUTO, "gp_per_reduce", CTLFLAG_RW,
862 	    &rack_per_of_gp_probertt_reduce, 10,
863 	    "What percentage of goodput do we reduce every gp_srtt");
864 	SYSCTL_ADD_U16(&rack_sysctl_ctx,
865 	    SYSCTL_CHILDREN(rack_probertt),
866 	    OID_AUTO, "gp_per_low", CTLFLAG_RW,
867 	    &rack_per_of_gp_lowthresh, 40,
868 	    "What percentage of goodput do we allow the multiplier to fall to");
869 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
870 	    SYSCTL_CHILDREN(rack_probertt),
871 	    OID_AUTO, "time_between", CTLFLAG_RW,
872 	    & rack_time_between_probertt, 96000000,
873 	    "How many useconds between the lowest rtt falling must past before we enter probertt");
874 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
875 	    SYSCTL_CHILDREN(rack_probertt),
876 	    OID_AUTO, "safety", CTLFLAG_RW,
877 	    &rack_probe_rtt_safety_val, 2000000,
878 	    "If not zero, provides a maximum usecond that you can stay in probertt (2sec = 2000000)");
879 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
880 	    SYSCTL_CHILDREN(rack_probertt),
881 	    OID_AUTO, "sets_cwnd", CTLFLAG_RW,
882 	    &rack_probe_rtt_sets_cwnd, 0,
883 	    "Do we set the cwnd too (if always_lower is on)");
884 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
885 	    SYSCTL_CHILDREN(rack_probertt),
886 	    OID_AUTO, "maxdrainsrtts", CTLFLAG_RW,
887 	    &rack_max_drain_wait, 2,
888 	    "Maximum number of gp_srtt's to hold in drain waiting for flight to reach goal");
889 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
890 	    SYSCTL_CHILDREN(rack_probertt),
891 	    OID_AUTO, "mustdrainsrtts", CTLFLAG_RW,
892 	    &rack_must_drain, 1,
893 	    "We must drain this many gp_srtt's waiting for flight to reach goal");
894 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
895 	    SYSCTL_CHILDREN(rack_probertt),
896 	    OID_AUTO, "goal_use_min_entry", CTLFLAG_RW,
897 	    &rack_probertt_use_min_rtt_entry, 1,
898 	    "Should we use the min-rtt to calculate the goal rtt (else gp_srtt) at entry");
899 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
900 	    SYSCTL_CHILDREN(rack_probertt),
901 	    OID_AUTO, "goal_use_min_exit", CTLFLAG_RW,
902 	    &rack_probertt_use_min_rtt_exit, 0,
903 	    "How to set cwnd at exit, 0 - dynamic, 1 - use min-rtt, 2 - use curgprtt, 3 - entry gp-rtt");
904 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
905 	    SYSCTL_CHILDREN(rack_probertt),
906 	    OID_AUTO, "length_div", CTLFLAG_RW,
907 	    &rack_probertt_gpsrtt_cnt_div, 0,
908 	    "How many recent goodput srtt periods plus hold tim does probertt last (bottom of fraction)");
909 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
910 	    SYSCTL_CHILDREN(rack_probertt),
911 	    OID_AUTO, "length_mul", CTLFLAG_RW,
912 	    &rack_probertt_gpsrtt_cnt_mul, 0,
913 	    "How many recent goodput srtt periods plus hold tim does probertt last (top of fraction)");
914 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
915 	    SYSCTL_CHILDREN(rack_probertt),
916 	    OID_AUTO, "holdtim_at_target", CTLFLAG_RW,
917 	    &rack_min_probertt_hold, 200000,
918 	    "What is the minimum time we hold probertt at target");
919 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
920 	    SYSCTL_CHILDREN(rack_probertt),
921 	    OID_AUTO, "filter_life", CTLFLAG_RW,
922 	    &rack_probertt_filter_life, 10000000,
923 	    "What is the time for the filters life in useconds");
924 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
925 	    SYSCTL_CHILDREN(rack_probertt),
926 	    OID_AUTO, "lower_within", CTLFLAG_RW,
927 	    &rack_probertt_lower_within, 10,
928 	    "If the rtt goes lower within this percentage of the time, go into probe-rtt");
929 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
930 	    SYSCTL_CHILDREN(rack_probertt),
931 	    OID_AUTO, "must_move", CTLFLAG_RW,
932 	    &rack_min_rtt_movement, 250,
933 	    "How much is the minimum movement in rtt to count as a drop for probertt purposes");
934 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
935 	    SYSCTL_CHILDREN(rack_probertt),
936 	    OID_AUTO, "clear_is_cnts", CTLFLAG_RW,
937 	    &rack_probertt_clear_is, 1,
938 	    "Do we clear I/S counts on exiting probe-rtt");
939 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
940 	    SYSCTL_CHILDREN(rack_probertt),
941 	    OID_AUTO, "hbp_extra_drain", CTLFLAG_RW,
942 	    &rack_max_drain_hbp, 1,
943 	    "How many extra drain gpsrtt's do we get in highly buffered paths");
944 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
945 	    SYSCTL_CHILDREN(rack_probertt),
946 	    OID_AUTO, "hbp_threshold", CTLFLAG_RW,
947 	    &rack_hbp_thresh, 3,
948 	    "We are highly buffered if min_rtt_seen / max_rtt_seen > this-threshold");
949 
950 	rack_tracepoint = SYSCTL_ADD_NODE(&rack_sysctl_ctx,
951 	    SYSCTL_CHILDREN(rack_sysctl_root),
952 	    OID_AUTO,
953 	    "tp",
954 	    CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
955 	    "Rack tracepoint facility");
956 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
957 	    SYSCTL_CHILDREN(rack_tracepoint),
958 	    OID_AUTO, "number", CTLFLAG_RW,
959 	    &rack_trace_point_config, 0,
960 	    "What is the trace point number to activate (0=none, 0xffffffff = all)?");
961 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
962 	    SYSCTL_CHILDREN(rack_tracepoint),
963 	    OID_AUTO, "bbmode", CTLFLAG_RW,
964 	    &rack_trace_point_bb_mode, 4,
965 	    "What is BB logging mode that is activated?");
966 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
967 	    SYSCTL_CHILDREN(rack_tracepoint),
968 	    OID_AUTO, "count", CTLFLAG_RW,
969 	    &rack_trace_point_count, 0,
970 	    "How many connections will have BB logging turned on that hit the tracepoint?");
971 	/* Pacing related sysctls */
972 	rack_pacing = SYSCTL_ADD_NODE(&rack_sysctl_ctx,
973 	    SYSCTL_CHILDREN(rack_sysctl_root),
974 	    OID_AUTO,
975 	    "pacing",
976 	    CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
977 	    "Pacing related Controls");
978 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
979 	    SYSCTL_CHILDREN(rack_pacing),
980 	    OID_AUTO, "max_pace_over", CTLFLAG_RW,
981 	    &rack_max_per_above, 30,
982 	    "What is the maximum allowable percentage that we can pace above (so 30 = 130% of our goal)");
983 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
984 	    SYSCTL_CHILDREN(rack_pacing),
985 	    OID_AUTO, "pace_to_one", CTLFLAG_RW,
986 	    &rack_pace_one_seg, 0,
987 	    "Do we allow low b/w pacing of 1MSS instead of two");
988 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
989 	    SYSCTL_CHILDREN(rack_pacing),
990 	    OID_AUTO, "limit_wsrtt", CTLFLAG_RW,
991 	    &rack_limit_time_with_srtt, 0,
992 	    "Do we limit pacing time based on srtt");
993 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
994 	    SYSCTL_CHILDREN(rack_pacing),
995 	    OID_AUTO, "init_win", CTLFLAG_RW,
996 	    &rack_default_init_window, 0,
997 	    "Do we have a rack initial window 0 = system default");
998 	SYSCTL_ADD_U16(&rack_sysctl_ctx,
999 	    SYSCTL_CHILDREN(rack_pacing),
1000 	    OID_AUTO, "gp_per_ss", CTLFLAG_RW,
1001 	    &rack_per_of_gp_ss, 250,
1002 	    "If non zero, what percentage of goodput to pace at in slow start");
1003 	SYSCTL_ADD_U16(&rack_sysctl_ctx,
1004 	    SYSCTL_CHILDREN(rack_pacing),
1005 	    OID_AUTO, "gp_per_ca", CTLFLAG_RW,
1006 	    &rack_per_of_gp_ca, 150,
1007 	    "If non zero, what percentage of goodput to pace at in congestion avoidance");
1008 	SYSCTL_ADD_U16(&rack_sysctl_ctx,
1009 	    SYSCTL_CHILDREN(rack_pacing),
1010 	    OID_AUTO, "gp_per_rec", CTLFLAG_RW,
1011 	    &rack_per_of_gp_rec, 200,
1012 	    "If non zero, what percentage of goodput to pace at in recovery");
1013 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1014 	    SYSCTL_CHILDREN(rack_pacing),
1015 	    OID_AUTO, "pace_max_seg", CTLFLAG_RW,
1016 	    &rack_hptsi_segments, 40,
1017 	    "What size is the max for TSO segments in pacing and burst mitigation");
1018 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1019 	    SYSCTL_CHILDREN(rack_pacing),
1020 	    OID_AUTO, "burst_reduces", CTLFLAG_RW,
1021 	    &rack_slot_reduction, 4,
1022 	    "When doing only burst mitigation what is the reduce divisor");
1023 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1024 	    SYSCTL_CHILDREN(rack_sysctl_root),
1025 	    OID_AUTO, "use_pacing", CTLFLAG_RW,
1026 	    &rack_pace_every_seg, 0,
1027 	    "If set we use pacing, if clear we use only the original burst mitigation");
1028 	SYSCTL_ADD_U64(&rack_sysctl_ctx,
1029 	    SYSCTL_CHILDREN(rack_pacing),
1030 	    OID_AUTO, "rate_cap", CTLFLAG_RW,
1031 	    &rack_bw_rate_cap, 0,
1032 	    "If set we apply this value to the absolute rate cap used by pacing");
1033 	SYSCTL_ADD_U8(&rack_sysctl_ctx,
1034 	    SYSCTL_CHILDREN(rack_sysctl_root),
1035 	    OID_AUTO, "req_measure_cnt", CTLFLAG_RW,
1036 	    &rack_req_measurements, 1,
1037 	    "If doing dynamic pacing, how many measurements must be in before we start pacing?");
1038 	/* Hardware pacing */
1039 	rack_hw_pacing = SYSCTL_ADD_NODE(&rack_sysctl_ctx,
1040 	    SYSCTL_CHILDREN(rack_sysctl_root),
1041 	    OID_AUTO,
1042 	    "hdwr_pacing",
1043 	    CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
1044 	    "Pacing related Controls");
1045 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1046 	    SYSCTL_CHILDREN(rack_hw_pacing),
1047 	    OID_AUTO, "rwnd_factor", CTLFLAG_RW,
1048 	    &rack_hw_rwnd_factor, 2,
1049 	    "How many times does snd_wnd need to be bigger than pace_max_seg so we will hold off and get more acks?");
1050 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1051 	    SYSCTL_CHILDREN(rack_hw_pacing),
1052 	    OID_AUTO, "pace_enobuf_mult", CTLFLAG_RW,
1053 	    &rack_enobuf_hw_boost_mult, 2,
1054 	    "By how many time_betweens should we boost the pacing time if we see a ENOBUFS?");
1055 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1056 	    SYSCTL_CHILDREN(rack_hw_pacing),
1057 	    OID_AUTO, "pace_enobuf_max", CTLFLAG_RW,
1058 	    &rack_enobuf_hw_max, 2,
1059 	    "What is the max boost the pacing time if we see a ENOBUFS?");
1060 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1061 	    SYSCTL_CHILDREN(rack_hw_pacing),
1062 	    OID_AUTO, "pace_enobuf_min", CTLFLAG_RW,
1063 	    &rack_enobuf_hw_min, 2,
1064 	    "What is the min boost the pacing time if we see a ENOBUFS?");
1065 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1066 	    SYSCTL_CHILDREN(rack_hw_pacing),
1067 	    OID_AUTO, "enable", CTLFLAG_RW,
1068 	    &rack_enable_hw_pacing, 0,
1069 	    "Should RACK attempt to use hw pacing?");
1070 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1071 	    SYSCTL_CHILDREN(rack_hw_pacing),
1072 	    OID_AUTO, "rate_cap", CTLFLAG_RW,
1073 	    &rack_hw_rate_caps, 1,
1074 	    "Does the highest hardware pacing rate cap the rate we will send at??");
1075 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1076 	    SYSCTL_CHILDREN(rack_hw_pacing),
1077 	    OID_AUTO, "rate_min", CTLFLAG_RW,
1078 	    &rack_hw_rate_min, 0,
1079 	    "Do we need a minimum estimate of this many bytes per second in order to engage hw pacing?");
1080 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1081 	    SYSCTL_CHILDREN(rack_hw_pacing),
1082 	    OID_AUTO, "rate_to_low", CTLFLAG_RW,
1083 	    &rack_hw_rate_to_low, 0,
1084 	    "If we fall below this rate, dis-engage hw pacing?");
1085 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1086 	    SYSCTL_CHILDREN(rack_hw_pacing),
1087 	    OID_AUTO, "up_only", CTLFLAG_RW,
1088 	    &rack_hw_up_only, 1,
1089 	    "Do we allow hw pacing to lower the rate selected?");
1090 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1091 	    SYSCTL_CHILDREN(rack_hw_pacing),
1092 	    OID_AUTO, "extra_mss_precise", CTLFLAG_RW,
1093 	    &rack_hw_pace_extra_slots, 2,
1094 	    "If the rates between software and hardware match precisely how many extra time_betweens do we get?");
1095 	rack_timely = SYSCTL_ADD_NODE(&rack_sysctl_ctx,
1096 	    SYSCTL_CHILDREN(rack_sysctl_root),
1097 	    OID_AUTO,
1098 	    "timely",
1099 	    CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
1100 	    "Rack Timely RTT Controls");
1101 	/* Timely based GP dynmics */
1102 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1103 	    SYSCTL_CHILDREN(rack_timely),
1104 	    OID_AUTO, "upper", CTLFLAG_RW,
1105 	    &rack_gp_per_bw_mul_up, 2,
1106 	    "Rack timely upper range for equal b/w (in percentage)");
1107 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1108 	    SYSCTL_CHILDREN(rack_timely),
1109 	    OID_AUTO, "lower", CTLFLAG_RW,
1110 	    &rack_gp_per_bw_mul_down, 4,
1111 	    "Rack timely lower range for equal b/w (in percentage)");
1112 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1113 	    SYSCTL_CHILDREN(rack_timely),
1114 	    OID_AUTO, "rtt_max_mul", CTLFLAG_RW,
1115 	    &rack_gp_rtt_maxmul, 3,
1116 	    "Rack timely multiplier of lowest rtt for rtt_max");
1117 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1118 	    SYSCTL_CHILDREN(rack_timely),
1119 	    OID_AUTO, "rtt_min_div", CTLFLAG_RW,
1120 	    &rack_gp_rtt_mindiv, 4,
1121 	    "Rack timely divisor used for rtt + (rtt * mul/divisor) for check for lower rtt");
1122 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1123 	    SYSCTL_CHILDREN(rack_timely),
1124 	    OID_AUTO, "rtt_min_mul", CTLFLAG_RW,
1125 	    &rack_gp_rtt_minmul, 1,
1126 	    "Rack timely multiplier used for rtt + (rtt * mul/divisor) for check for lower rtt");
1127 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1128 	    SYSCTL_CHILDREN(rack_timely),
1129 	    OID_AUTO, "decrease", CTLFLAG_RW,
1130 	    &rack_gp_decrease_per, 20,
1131 	    "Rack timely decrease percentage of our GP multiplication factor");
1132 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1133 	    SYSCTL_CHILDREN(rack_timely),
1134 	    OID_AUTO, "increase", CTLFLAG_RW,
1135 	    &rack_gp_increase_per, 2,
1136 	    "Rack timely increase perentage of our GP multiplication factor");
1137 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1138 	    SYSCTL_CHILDREN(rack_timely),
1139 	    OID_AUTO, "lowerbound", CTLFLAG_RW,
1140 	    &rack_per_lower_bound, 50,
1141 	    "Rack timely lowest percentage we allow GP multiplier to fall to");
1142 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1143 	    SYSCTL_CHILDREN(rack_timely),
1144 	    OID_AUTO, "upperboundss", CTLFLAG_RW,
1145 	    &rack_per_upper_bound_ss, 0,
1146 	    "Rack timely highest percentage we allow GP multiplier in SS to raise to (0 is no upperbound)");
1147 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1148 	    SYSCTL_CHILDREN(rack_timely),
1149 	    OID_AUTO, "upperboundca", CTLFLAG_RW,
1150 	    &rack_per_upper_bound_ca, 0,
1151 	    "Rack timely highest percentage we allow GP multiplier to CA raise to (0 is no upperbound)");
1152 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1153 	    SYSCTL_CHILDREN(rack_timely),
1154 	    OID_AUTO, "dynamicgp", CTLFLAG_RW,
1155 	    &rack_do_dyn_mul, 0,
1156 	    "Rack timely do we enable dynmaic timely goodput by default");
1157 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1158 	    SYSCTL_CHILDREN(rack_timely),
1159 	    OID_AUTO, "no_rec_red", CTLFLAG_RW,
1160 	    &rack_gp_no_rec_chg, 1,
1161 	    "Rack timely do we prohibit the recovery multiplier from being lowered");
1162 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1163 	    SYSCTL_CHILDREN(rack_timely),
1164 	    OID_AUTO, "red_clear_cnt", CTLFLAG_RW,
1165 	    &rack_timely_dec_clear, 6,
1166 	    "Rack timely what threshold do we count to before another boost during b/w decent");
1167 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1168 	    SYSCTL_CHILDREN(rack_timely),
1169 	    OID_AUTO, "max_push_rise", CTLFLAG_RW,
1170 	    &rack_timely_max_push_rise, 3,
1171 	    "Rack timely how many times do we push up with b/w increase");
1172 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1173 	    SYSCTL_CHILDREN(rack_timely),
1174 	    OID_AUTO, "max_push_drop", CTLFLAG_RW,
1175 	    &rack_timely_max_push_drop, 3,
1176 	    "Rack timely how many times do we push back on b/w decent");
1177 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1178 	    SYSCTL_CHILDREN(rack_timely),
1179 	    OID_AUTO, "min_segs", CTLFLAG_RW,
1180 	    &rack_timely_min_segs, 4,
1181 	    "Rack timely when setting the cwnd what is the min num segments");
1182 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1183 	    SYSCTL_CHILDREN(rack_timely),
1184 	    OID_AUTO, "noback_max", CTLFLAG_RW,
1185 	    &rack_use_max_for_nobackoff, 0,
1186 	    "Rack timely when deciding if to backoff on a loss, do we use under max rtt else min");
1187 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1188 	    SYSCTL_CHILDREN(rack_timely),
1189 	    OID_AUTO, "interim_timely_only", CTLFLAG_RW,
1190 	    &rack_timely_int_timely_only, 0,
1191 	    "Rack timely when doing interim timely's do we only do timely (no b/w consideration)");
1192 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1193 	    SYSCTL_CHILDREN(rack_timely),
1194 	    OID_AUTO, "nonstop", CTLFLAG_RW,
1195 	    &rack_timely_no_stopping, 0,
1196 	    "Rack timely don't stop increase");
1197 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1198 	    SYSCTL_CHILDREN(rack_timely),
1199 	    OID_AUTO, "dec_raise_thresh", CTLFLAG_RW,
1200 	    &rack_down_raise_thresh, 100,
1201 	    "If the CA or SS is below this threshold raise on the first 3 b/w lowers (0=always)");
1202 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1203 	    SYSCTL_CHILDREN(rack_timely),
1204 	    OID_AUTO, "bottom_drag_segs", CTLFLAG_RW,
1205 	    &rack_req_segs, 1,
1206 	    "Bottom dragging if not these many segments outstanding and room");
1207 
1208 	/* TLP and Rack related parameters */
1209 	rack_tlp = SYSCTL_ADD_NODE(&rack_sysctl_ctx,
1210 	    SYSCTL_CHILDREN(rack_sysctl_root),
1211 	    OID_AUTO,
1212 	    "tlp",
1213 	    CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
1214 	    "TLP and Rack related Controls");
1215 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1216 	    SYSCTL_CHILDREN(rack_tlp),
1217 	    OID_AUTO, "use_rrr", CTLFLAG_RW,
1218 	    &use_rack_rr, 1,
1219 	    "Do we use Rack Rapid Recovery");
1220 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1221 	    SYSCTL_CHILDREN(rack_tlp),
1222 	    OID_AUTO, "post_rec_labc", CTLFLAG_RW,
1223 	    &rack_max_abc_post_recovery, 2,
1224 	    "Since we do early recovery, do we override the l_abc to a value, if so what?");
1225 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1226 	    SYSCTL_CHILDREN(rack_tlp),
1227 	    OID_AUTO, "nonrxt_use_cr", CTLFLAG_RW,
1228 	    &rack_non_rxt_use_cr, 0,
1229 	    "Do we use ss/ca rate if in recovery we are transmitting a new data chunk");
1230 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1231 	    SYSCTL_CHILDREN(rack_tlp),
1232 	    OID_AUTO, "tlpmethod", CTLFLAG_RW,
1233 	    &rack_tlp_threshold_use, TLP_USE_TWO_ONE,
1234 	    "What method do we do for TLP time calc 0=no-de-ack-comp, 1=ID, 2=2.1, 3=2.2");
1235 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1236 	    SYSCTL_CHILDREN(rack_tlp),
1237 	    OID_AUTO, "limit", CTLFLAG_RW,
1238 	    &rack_tlp_limit, 2,
1239 	    "How many TLP's can be sent without sending new data");
1240 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1241 	    SYSCTL_CHILDREN(rack_tlp),
1242 	    OID_AUTO, "use_greater", CTLFLAG_RW,
1243 	    &rack_tlp_use_greater, 1,
1244 	    "Should we use the rack_rtt time if its greater than srtt");
1245 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1246 	    SYSCTL_CHILDREN(rack_tlp),
1247 	    OID_AUTO, "tlpminto", CTLFLAG_RW,
1248 	    &rack_tlp_min, 10000,
1249 	    "TLP minimum timeout per the specification (in microseconds)");
1250 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1251 	    SYSCTL_CHILDREN(rack_tlp),
1252 	    OID_AUTO, "send_oldest", CTLFLAG_RW,
1253 	    &rack_always_send_oldest, 0,
1254 	    "Should we always send the oldest TLP and RACK-TLP");
1255 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1256 	    SYSCTL_CHILDREN(rack_tlp),
1257 	    OID_AUTO, "rack_tlimit", CTLFLAG_RW,
1258 	    &rack_limited_retran, 0,
1259 	    "How many times can a rack timeout drive out sends");
1260 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1261 	    SYSCTL_CHILDREN(rack_tlp),
1262 	    OID_AUTO, "tlp_cwnd_flag", CTLFLAG_RW,
1263 	    &rack_lower_cwnd_at_tlp, 0,
1264 	    "When a TLP completes a retran should we enter recovery");
1265 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1266 	    SYSCTL_CHILDREN(rack_tlp),
1267 	    OID_AUTO, "reorder_thresh", CTLFLAG_RW,
1268 	    &rack_reorder_thresh, 2,
1269 	    "What factor for rack will be added when seeing reordering (shift right)");
1270 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1271 	    SYSCTL_CHILDREN(rack_tlp),
1272 	    OID_AUTO, "rtt_tlp_thresh", CTLFLAG_RW,
1273 	    &rack_tlp_thresh, 1,
1274 	    "What divisor for TLP rtt/retran will be added (1=rtt, 2=1/2 rtt etc)");
1275 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1276 	    SYSCTL_CHILDREN(rack_tlp),
1277 	    OID_AUTO, "reorder_fade", CTLFLAG_RW,
1278 	    &rack_reorder_fade, 60000000,
1279 	    "Does reorder detection fade, if so how many microseconds (0 means never)");
1280 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1281 	    SYSCTL_CHILDREN(rack_tlp),
1282 	    OID_AUTO, "pktdelay", CTLFLAG_RW,
1283 	    &rack_pkt_delay, 1000,
1284 	    "Extra RACK time (in microseconds) besides reordering thresh");
1285 
1286 	/* Timer related controls */
1287 	rack_timers = SYSCTL_ADD_NODE(&rack_sysctl_ctx,
1288 	    SYSCTL_CHILDREN(rack_sysctl_root),
1289 	    OID_AUTO,
1290 	    "timers",
1291 	    CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
1292 	    "Timer related controls");
1293 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
1294 	    SYSCTL_CHILDREN(rack_timers),
1295 	    OID_AUTO, "persmin", CTLFLAG_RW,
1296 	    &rack_persist_min, 250000,
1297 	    "What is the minimum time in microseconds between persists");
1298 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
1299 	    SYSCTL_CHILDREN(rack_timers),
1300 	    OID_AUTO, "persmax", CTLFLAG_RW,
1301 	    &rack_persist_max, 2000000,
1302 	    "What is the largest delay in microseconds between persists");
1303 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1304 	    SYSCTL_CHILDREN(rack_timers),
1305 	    OID_AUTO, "delayed_ack", CTLFLAG_RW,
1306 	    &rack_delayed_ack_time, 40000,
1307 	    "Delayed ack time (40ms in microseconds)");
1308 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1309 	    SYSCTL_CHILDREN(rack_timers),
1310 	    OID_AUTO, "minrto", CTLFLAG_RW,
1311 	    &rack_rto_min, 30000,
1312 	    "Minimum RTO in microseconds -- set with caution below 1000 due to TLP");
1313 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1314 	    SYSCTL_CHILDREN(rack_timers),
1315 	    OID_AUTO, "maxrto", CTLFLAG_RW,
1316 	    &rack_rto_max, 4000000,
1317 	    "Maximum RTO in microseconds -- should be at least as large as min_rto");
1318 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1319 	    SYSCTL_CHILDREN(rack_timers),
1320 	    OID_AUTO, "minto", CTLFLAG_RW,
1321 	    &rack_min_to, 1000,
1322 	    "Minimum rack timeout in microseconds");
1323 	/* Measure controls */
1324 	rack_measure = SYSCTL_ADD_NODE(&rack_sysctl_ctx,
1325 	    SYSCTL_CHILDREN(rack_sysctl_root),
1326 	    OID_AUTO,
1327 	    "measure",
1328 	    CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
1329 	    "Measure related controls");
1330 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1331 	    SYSCTL_CHILDREN(rack_measure),
1332 	    OID_AUTO, "wma_divisor", CTLFLAG_RW,
1333 	    &rack_wma_divisor, 8,
1334 	    "When doing b/w calculation what is the  divisor for the WMA");
1335 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1336 	    SYSCTL_CHILDREN(rack_measure),
1337 	    OID_AUTO, "end_cwnd", CTLFLAG_RW,
1338 	    &rack_cwnd_block_ends_measure, 0,
1339 	    "Does a cwnd just-return end the measurement window (app limited)");
1340 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1341 	    SYSCTL_CHILDREN(rack_measure),
1342 	    OID_AUTO, "end_rwnd", CTLFLAG_RW,
1343 	    &rack_rwnd_block_ends_measure, 0,
1344 	    "Does an rwnd just-return end the measurement window (app limited -- not persists)");
1345 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
1346 	    SYSCTL_CHILDREN(rack_measure),
1347 	    OID_AUTO, "min_target", CTLFLAG_RW,
1348 	    &rack_def_data_window, 20,
1349 	    "What is the minimum target window (in mss) for a GP measurements");
1350 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
1351 	    SYSCTL_CHILDREN(rack_measure),
1352 	    OID_AUTO, "goal_bdp", CTLFLAG_RW,
1353 	    &rack_goal_bdp, 2,
1354 	    "What is the goal BDP to measure");
1355 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
1356 	    SYSCTL_CHILDREN(rack_measure),
1357 	    OID_AUTO, "min_srtts", CTLFLAG_RW,
1358 	    &rack_min_srtts, 1,
1359 	    "What is the goal BDP to measure");
1360 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
1361 	    SYSCTL_CHILDREN(rack_measure),
1362 	    OID_AUTO, "min_measure_tim", CTLFLAG_RW,
1363 	    &rack_min_measure_usec, 0,
1364 	    "What is the Minimum time time for a measurement if 0, this is off");
1365 	/* Features */
1366 	rack_features = SYSCTL_ADD_NODE(&rack_sysctl_ctx,
1367 	    SYSCTL_CHILDREN(rack_sysctl_root),
1368 	    OID_AUTO,
1369 	    "features",
1370 	    CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
1371 	    "Feature controls");
1372 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1373 	    SYSCTL_CHILDREN(rack_features),
1374 	    OID_AUTO, "cmpack", CTLFLAG_RW,
1375 	    &rack_use_cmp_acks, 1,
1376 	    "Should RACK have LRO send compressed acks");
1377 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1378 	    SYSCTL_CHILDREN(rack_features),
1379 	    OID_AUTO, "fsb", CTLFLAG_RW,
1380 	    &rack_use_fsb, 1,
1381 	    "Should RACK use the fast send block?");
1382 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1383 	    SYSCTL_CHILDREN(rack_features),
1384 	    OID_AUTO, "rfo", CTLFLAG_RW,
1385 	    &rack_use_rfo, 1,
1386 	    "Should RACK use rack_fast_output()?");
1387 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1388 	    SYSCTL_CHILDREN(rack_features),
1389 	    OID_AUTO, "rsmrfo", CTLFLAG_RW,
1390 	    &rack_use_rsm_rfo, 1,
1391 	    "Should RACK use rack_fast_rsm_output()?");
1392 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1393 	    SYSCTL_CHILDREN(rack_features),
1394 	    OID_AUTO, "non_paced_lro_queue", CTLFLAG_RW,
1395 	    &rack_enable_mqueue_for_nonpaced, 0,
1396 	    "Should RACK use mbuf queuing for non-paced connections");
1397 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1398 	    SYSCTL_CHILDREN(rack_features),
1399 	    OID_AUTO, "hystartplusplus", CTLFLAG_RW,
1400 	    &rack_do_hystart, 0,
1401 	    "Should RACK enable HyStart++ on connections?");
1402 	/* Misc rack controls */
1403 	rack_misc = SYSCTL_ADD_NODE(&rack_sysctl_ctx,
1404 	    SYSCTL_CHILDREN(rack_sysctl_root),
1405 	    OID_AUTO,
1406 	    "misc",
1407 	    CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
1408 	    "Misc related controls");
1409 #ifdef TCP_ACCOUNTING
1410 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1411 	    SYSCTL_CHILDREN(rack_misc),
1412 	    OID_AUTO, "tcp_acct", CTLFLAG_RW,
1413 	    &rack_tcp_accounting, 0,
1414 	    "Should we turn on TCP accounting for all rack sessions?");
1415 #endif
1416 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1417 	    SYSCTL_CHILDREN(rack_misc),
1418 	    OID_AUTO, "apply_rtt_with_low_conf", CTLFLAG_RW,
1419 	    &rack_apply_rtt_with_reduced_conf, 0,
1420 	    "When a persist or keep-alive probe is not answered do we calculate rtt on subsequent answers?");
1421 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1422 	    SYSCTL_CHILDREN(rack_misc),
1423 	    OID_AUTO, "rack_dsack_ctl", CTLFLAG_RW,
1424 	    &rack_dsack_std_based, 3,
1425 	    "How do we process dsack with respect to rack timers, bit field, 3 is standards based?");
1426 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1427 	    SYSCTL_CHILDREN(rack_misc),
1428 	    OID_AUTO, "prr_addback_max", CTLFLAG_RW,
1429 	    &rack_prr_addbackmax, 2,
1430 	    "What is the maximum number of MSS we allow to be added back if prr can't send all its data?");
1431 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1432 	    SYSCTL_CHILDREN(rack_misc),
1433 	    OID_AUTO, "stats_gets_ms", CTLFLAG_RW,
1434 	    &rack_stats_gets_ms_rtt, 1,
1435 	    "What do we feed the stats framework (1 = ms_rtt, 0 = us_rtt, 2 = ms_rtt from hdwr, > 2 usec rtt from hdwr)?");
1436 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1437 	    SYSCTL_CHILDREN(rack_misc),
1438 	    OID_AUTO, "clientlowbuf", CTLFLAG_RW,
1439 	    &rack_client_low_buf, 0,
1440 	    "Client low buffer level (below this we are more aggressive in DGP exiting recovery (0 = off)?");
1441 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1442 	    SYSCTL_CHILDREN(rack_misc),
1443 	    OID_AUTO, "defprofile", CTLFLAG_RW,
1444 	    &rack_def_profile, 0,
1445 	    "Should RACK use a default profile (0=no, num == profile num)?");
1446 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1447 	    SYSCTL_CHILDREN(rack_misc),
1448 	    OID_AUTO, "shared_cwnd", CTLFLAG_RW,
1449 	    &rack_enable_shared_cwnd, 1,
1450 	    "Should RACK try to use the shared cwnd on connections where allowed");
1451 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1452 	    SYSCTL_CHILDREN(rack_misc),
1453 	    OID_AUTO, "limits_on_scwnd", CTLFLAG_RW,
1454 	    &rack_limits_scwnd, 1,
1455 	    "Should RACK place low end time limits on the shared cwnd feature");
1456 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1457 	    SYSCTL_CHILDREN(rack_misc),
1458 	    OID_AUTO, "iMac_dack", CTLFLAG_RW,
1459 	    &rack_use_imac_dack, 0,
1460 	    "Should RACK try to emulate iMac delayed ack");
1461 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1462 	    SYSCTL_CHILDREN(rack_misc),
1463 	    OID_AUTO, "no_prr", CTLFLAG_RW,
1464 	    &rack_disable_prr, 0,
1465 	    "Should RACK not use prr and only pace (must have pacing on)");
1466 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1467 	    SYSCTL_CHILDREN(rack_misc),
1468 	    OID_AUTO, "bb_verbose", CTLFLAG_RW,
1469 	    &rack_verbose_logging, 0,
1470 	    "Should RACK black box logging be verbose");
1471 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1472 	    SYSCTL_CHILDREN(rack_misc),
1473 	    OID_AUTO, "data_after_close", CTLFLAG_RW,
1474 	    &rack_ignore_data_after_close, 1,
1475 	    "Do we hold off sending a RST until all pending data is ack'd");
1476 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1477 	    SYSCTL_CHILDREN(rack_misc),
1478 	    OID_AUTO, "no_sack_needed", CTLFLAG_RW,
1479 	    &rack_sack_not_required, 1,
1480 	    "Do we allow rack to run on connections not supporting SACK");
1481 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1482 	    SYSCTL_CHILDREN(rack_misc),
1483 	    OID_AUTO, "prr_sendalot", CTLFLAG_RW,
1484 	    &rack_send_a_lot_in_prr, 1,
1485 	    "Send a lot in prr");
1486 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1487 	    SYSCTL_CHILDREN(rack_misc),
1488 	    OID_AUTO, "autoscale", CTLFLAG_RW,
1489 	    &rack_autosndbuf_inc, 20,
1490 	    "What percentage should rack scale up its snd buffer by?");
1491 	/* Sack Attacker detection stuff */
1492 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
1493 	    SYSCTL_CHILDREN(rack_attack),
1494 	    OID_AUTO, "detect_highsackratio", CTLFLAG_RW,
1495 	    &rack_highest_sack_thresh_seen, 0,
1496 	    "Highest sack to ack ratio seen");
1497 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
1498 	    SYSCTL_CHILDREN(rack_attack),
1499 	    OID_AUTO, "detect_highmoveratio", CTLFLAG_RW,
1500 	    &rack_highest_move_thresh_seen, 0,
1501 	    "Highest move to non-move ratio seen");
1502 	rack_ack_total = counter_u64_alloc(M_WAITOK);
1503 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1504 	    SYSCTL_CHILDREN(rack_attack),
1505 	    OID_AUTO, "acktotal", CTLFLAG_RD,
1506 	    &rack_ack_total,
1507 	    "Total number of Ack's");
1508 	rack_express_sack = counter_u64_alloc(M_WAITOK);
1509 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1510 	    SYSCTL_CHILDREN(rack_attack),
1511 	    OID_AUTO, "exp_sacktotal", CTLFLAG_RD,
1512 	    &rack_express_sack,
1513 	    "Total expresss number of Sack's");
1514 	rack_sack_total = counter_u64_alloc(M_WAITOK);
1515 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1516 	    SYSCTL_CHILDREN(rack_attack),
1517 	    OID_AUTO, "sacktotal", CTLFLAG_RD,
1518 	    &rack_sack_total,
1519 	    "Total number of SACKs");
1520 	rack_move_none = counter_u64_alloc(M_WAITOK);
1521 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1522 	    SYSCTL_CHILDREN(rack_attack),
1523 	    OID_AUTO, "move_none", CTLFLAG_RD,
1524 	    &rack_move_none,
1525 	    "Total number of SACK index reuse of positions under threshold");
1526 	rack_move_some = counter_u64_alloc(M_WAITOK);
1527 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1528 	    SYSCTL_CHILDREN(rack_attack),
1529 	    OID_AUTO, "move_some", CTLFLAG_RD,
1530 	    &rack_move_some,
1531 	    "Total number of SACK index reuse of positions over threshold");
1532 	rack_sack_attacks_detected = counter_u64_alloc(M_WAITOK);
1533 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1534 	    SYSCTL_CHILDREN(rack_attack),
1535 	    OID_AUTO, "attacks", CTLFLAG_RD,
1536 	    &rack_sack_attacks_detected,
1537 	    "Total number of SACK attackers that had sack disabled");
1538 	rack_sack_attacks_reversed = counter_u64_alloc(M_WAITOK);
1539 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1540 	    SYSCTL_CHILDREN(rack_attack),
1541 	    OID_AUTO, "reversed", CTLFLAG_RD,
1542 	    &rack_sack_attacks_reversed,
1543 	    "Total number of SACK attackers that were later determined false positive");
1544 	rack_sack_used_next_merge = counter_u64_alloc(M_WAITOK);
1545 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1546 	    SYSCTL_CHILDREN(rack_attack),
1547 	    OID_AUTO, "nextmerge", CTLFLAG_RD,
1548 	    &rack_sack_used_next_merge,
1549 	    "Total number of times we used the next merge");
1550 	rack_sack_used_prev_merge = counter_u64_alloc(M_WAITOK);
1551 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1552 	    SYSCTL_CHILDREN(rack_attack),
1553 	    OID_AUTO, "prevmerge", CTLFLAG_RD,
1554 	    &rack_sack_used_prev_merge,
1555 	    "Total number of times we used the prev merge");
1556 	/* Counters */
1557 	rack_fto_send = counter_u64_alloc(M_WAITOK);
1558 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1559 	    SYSCTL_CHILDREN(rack_counters),
1560 	    OID_AUTO, "fto_send", CTLFLAG_RD,
1561 	    &rack_fto_send, "Total number of rack_fast_output sends");
1562 	rack_fto_rsm_send = counter_u64_alloc(M_WAITOK);
1563 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1564 	    SYSCTL_CHILDREN(rack_counters),
1565 	    OID_AUTO, "fto_rsm_send", CTLFLAG_RD,
1566 	    &rack_fto_rsm_send, "Total number of rack_fast_rsm_output sends");
1567 	rack_nfto_resend = counter_u64_alloc(M_WAITOK);
1568 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1569 	    SYSCTL_CHILDREN(rack_counters),
1570 	    OID_AUTO, "nfto_resend", CTLFLAG_RD,
1571 	    &rack_nfto_resend, "Total number of rack_output retransmissions");
1572 	rack_non_fto_send = counter_u64_alloc(M_WAITOK);
1573 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1574 	    SYSCTL_CHILDREN(rack_counters),
1575 	    OID_AUTO, "nfto_send", CTLFLAG_RD,
1576 	    &rack_non_fto_send, "Total number of rack_output first sends");
1577 	rack_extended_rfo = counter_u64_alloc(M_WAITOK);
1578 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1579 	    SYSCTL_CHILDREN(rack_counters),
1580 	    OID_AUTO, "rfo_extended", CTLFLAG_RD,
1581 	    &rack_extended_rfo, "Total number of times we extended rfo");
1582 
1583 	rack_hw_pace_init_fail = counter_u64_alloc(M_WAITOK);
1584 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1585 	    SYSCTL_CHILDREN(rack_counters),
1586 	    OID_AUTO, "hwpace_init_fail", CTLFLAG_RD,
1587 	    &rack_hw_pace_init_fail, "Total number of times we failed to initialize hw pacing");
1588 	rack_hw_pace_lost = counter_u64_alloc(M_WAITOK);
1589 
1590 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1591 	    SYSCTL_CHILDREN(rack_counters),
1592 	    OID_AUTO, "hwpace_lost", CTLFLAG_RD,
1593 	    &rack_hw_pace_lost, "Total number of times we failed to initialize hw pacing");
1594 	rack_tlp_tot = counter_u64_alloc(M_WAITOK);
1595 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1596 	    SYSCTL_CHILDREN(rack_counters),
1597 	    OID_AUTO, "tlp_to_total", CTLFLAG_RD,
1598 	    &rack_tlp_tot,
1599 	    "Total number of tail loss probe expirations");
1600 	rack_tlp_newdata = counter_u64_alloc(M_WAITOK);
1601 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1602 	    SYSCTL_CHILDREN(rack_counters),
1603 	    OID_AUTO, "tlp_new", CTLFLAG_RD,
1604 	    &rack_tlp_newdata,
1605 	    "Total number of tail loss probe sending new data");
1606 	rack_tlp_retran = counter_u64_alloc(M_WAITOK);
1607 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1608 	    SYSCTL_CHILDREN(rack_counters),
1609 	    OID_AUTO, "tlp_retran", CTLFLAG_RD,
1610 	    &rack_tlp_retran,
1611 	    "Total number of tail loss probe sending retransmitted data");
1612 	rack_tlp_retran_bytes = counter_u64_alloc(M_WAITOK);
1613 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1614 	    SYSCTL_CHILDREN(rack_counters),
1615 	    OID_AUTO, "tlp_retran_bytes", CTLFLAG_RD,
1616 	    &rack_tlp_retran_bytes,
1617 	    "Total bytes of tail loss probe sending retransmitted data");
1618 	rack_to_tot = counter_u64_alloc(M_WAITOK);
1619 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1620 	    SYSCTL_CHILDREN(rack_counters),
1621 	    OID_AUTO, "rack_to_tot", CTLFLAG_RD,
1622 	    &rack_to_tot,
1623 	    "Total number of times the rack to expired");
1624 	rack_saw_enobuf = counter_u64_alloc(M_WAITOK);
1625 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1626 	    SYSCTL_CHILDREN(rack_counters),
1627 	    OID_AUTO, "saw_enobufs", CTLFLAG_RD,
1628 	    &rack_saw_enobuf,
1629 	    "Total number of times a sends returned enobuf for non-hdwr paced connections");
1630 	rack_saw_enobuf_hw = counter_u64_alloc(M_WAITOK);
1631 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1632 	    SYSCTL_CHILDREN(rack_counters),
1633 	    OID_AUTO, "saw_enobufs_hw", CTLFLAG_RD,
1634 	    &rack_saw_enobuf_hw,
1635 	    "Total number of times a send returned enobuf for hdwr paced connections");
1636 	rack_saw_enetunreach = counter_u64_alloc(M_WAITOK);
1637 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1638 	    SYSCTL_CHILDREN(rack_counters),
1639 	    OID_AUTO, "saw_enetunreach", CTLFLAG_RD,
1640 	    &rack_saw_enetunreach,
1641 	    "Total number of times a send received a enetunreachable");
1642 	rack_hot_alloc = counter_u64_alloc(M_WAITOK);
1643 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1644 	    SYSCTL_CHILDREN(rack_counters),
1645 	    OID_AUTO, "alloc_hot", CTLFLAG_RD,
1646 	    &rack_hot_alloc,
1647 	    "Total allocations from the top of our list");
1648 	rack_to_alloc = counter_u64_alloc(M_WAITOK);
1649 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1650 	    SYSCTL_CHILDREN(rack_counters),
1651 	    OID_AUTO, "allocs", CTLFLAG_RD,
1652 	    &rack_to_alloc,
1653 	    "Total allocations of tracking structures");
1654 	rack_to_alloc_hard = counter_u64_alloc(M_WAITOK);
1655 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1656 	    SYSCTL_CHILDREN(rack_counters),
1657 	    OID_AUTO, "allochard", CTLFLAG_RD,
1658 	    &rack_to_alloc_hard,
1659 	    "Total allocations done with sleeping the hard way");
1660 	rack_to_alloc_emerg = counter_u64_alloc(M_WAITOK);
1661 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1662 	    SYSCTL_CHILDREN(rack_counters),
1663 	    OID_AUTO, "allocemerg", CTLFLAG_RD,
1664 	    &rack_to_alloc_emerg,
1665 	    "Total allocations done from emergency cache");
1666 	rack_to_alloc_limited = counter_u64_alloc(M_WAITOK);
1667 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1668 	    SYSCTL_CHILDREN(rack_counters),
1669 	    OID_AUTO, "alloc_limited", CTLFLAG_RD,
1670 	    &rack_to_alloc_limited,
1671 	    "Total allocations dropped due to limit");
1672 	rack_alloc_limited_conns = counter_u64_alloc(M_WAITOK);
1673 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1674 	    SYSCTL_CHILDREN(rack_counters),
1675 	    OID_AUTO, "alloc_limited_conns", CTLFLAG_RD,
1676 	    &rack_alloc_limited_conns,
1677 	    "Connections with allocations dropped due to limit");
1678 	rack_split_limited = counter_u64_alloc(M_WAITOK);
1679 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1680 	    SYSCTL_CHILDREN(rack_counters),
1681 	    OID_AUTO, "split_limited", CTLFLAG_RD,
1682 	    &rack_split_limited,
1683 	    "Split allocations dropped due to limit");
1684 	rack_persists_sends = counter_u64_alloc(M_WAITOK);
1685 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1686 	    SYSCTL_CHILDREN(rack_counters),
1687 	    OID_AUTO, "persist_sends", CTLFLAG_RD,
1688 	    &rack_persists_sends,
1689 	    "Number of times we sent a persist probe");
1690 	rack_persists_acks = counter_u64_alloc(M_WAITOK);
1691 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1692 	    SYSCTL_CHILDREN(rack_counters),
1693 	    OID_AUTO, "persist_acks", CTLFLAG_RD,
1694 	    &rack_persists_acks,
1695 	    "Number of times a persist probe was acked");
1696 	rack_persists_loss = counter_u64_alloc(M_WAITOK);
1697 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1698 	    SYSCTL_CHILDREN(rack_counters),
1699 	    OID_AUTO, "persist_loss", CTLFLAG_RD,
1700 	    &rack_persists_loss,
1701 	    "Number of times we detected a lost persist probe (no ack)");
1702 	rack_persists_lost_ends = counter_u64_alloc(M_WAITOK);
1703 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1704 	    SYSCTL_CHILDREN(rack_counters),
1705 	    OID_AUTO, "persist_loss_ends", CTLFLAG_RD,
1706 	    &rack_persists_lost_ends,
1707 	    "Number of lost persist probe (no ack) that the run ended with a PERSIST abort");
1708 #ifdef INVARIANTS
1709 	rack_adjust_map_bw = counter_u64_alloc(M_WAITOK);
1710 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1711 	    SYSCTL_CHILDREN(rack_counters),
1712 	    OID_AUTO, "map_adjust_req", CTLFLAG_RD,
1713 	    &rack_adjust_map_bw,
1714 	    "Number of times we hit the case where the sb went up and down on a sendmap entry");
1715 #endif
1716 	rack_multi_single_eq = counter_u64_alloc(M_WAITOK);
1717 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1718 	    SYSCTL_CHILDREN(rack_counters),
1719 	    OID_AUTO, "cmp_ack_equiv", CTLFLAG_RD,
1720 	    &rack_multi_single_eq,
1721 	    "Number of compressed acks total represented");
1722 	rack_proc_non_comp_ack = counter_u64_alloc(M_WAITOK);
1723 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1724 	    SYSCTL_CHILDREN(rack_counters),
1725 	    OID_AUTO, "cmp_ack_not", CTLFLAG_RD,
1726 	    &rack_proc_non_comp_ack,
1727 	    "Number of non compresseds acks that we processed");
1728 
1729 
1730 	rack_sack_proc_all = counter_u64_alloc(M_WAITOK);
1731 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1732 	    SYSCTL_CHILDREN(rack_counters),
1733 	    OID_AUTO, "sack_long", CTLFLAG_RD,
1734 	    &rack_sack_proc_all,
1735 	    "Total times we had to walk whole list for sack processing");
1736 	rack_sack_proc_restart = counter_u64_alloc(M_WAITOK);
1737 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1738 	    SYSCTL_CHILDREN(rack_counters),
1739 	    OID_AUTO, "sack_restart", CTLFLAG_RD,
1740 	    &rack_sack_proc_restart,
1741 	    "Total times we had to walk whole list due to a restart");
1742 	rack_sack_proc_short = counter_u64_alloc(M_WAITOK);
1743 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1744 	    SYSCTL_CHILDREN(rack_counters),
1745 	    OID_AUTO, "sack_short", CTLFLAG_RD,
1746 	    &rack_sack_proc_short,
1747 	    "Total times we took shortcut for sack processing");
1748 	rack_sack_skipped_acked = counter_u64_alloc(M_WAITOK);
1749 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1750 	    SYSCTL_CHILDREN(rack_attack),
1751 	    OID_AUTO, "skipacked", CTLFLAG_RD,
1752 	    &rack_sack_skipped_acked,
1753 	    "Total number of times we skipped previously sacked");
1754 	rack_sack_splits = counter_u64_alloc(M_WAITOK);
1755 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1756 	    SYSCTL_CHILDREN(rack_attack),
1757 	    OID_AUTO, "ofsplit", CTLFLAG_RD,
1758 	    &rack_sack_splits,
1759 	    "Total number of times we did the old fashion tree split");
1760 	rack_input_idle_reduces = counter_u64_alloc(M_WAITOK);
1761 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1762 	    SYSCTL_CHILDREN(rack_counters),
1763 	    OID_AUTO, "idle_reduce_oninput", CTLFLAG_RD,
1764 	    &rack_input_idle_reduces,
1765 	    "Total number of idle reductions on input");
1766 	rack_collapsed_win_seen = counter_u64_alloc(M_WAITOK);
1767 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1768 	    SYSCTL_CHILDREN(rack_counters),
1769 	    OID_AUTO, "collapsed_win_seen", CTLFLAG_RD,
1770 	    &rack_collapsed_win_seen,
1771 	    "Total number of collapsed window events seen (where our window shrinks)");
1772 
1773 	rack_collapsed_win = counter_u64_alloc(M_WAITOK);
1774 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1775 	    SYSCTL_CHILDREN(rack_counters),
1776 	    OID_AUTO, "collapsed_win", CTLFLAG_RD,
1777 	    &rack_collapsed_win,
1778 	    "Total number of collapsed window events where we mark packets");
1779 	rack_collapsed_win_rxt = counter_u64_alloc(M_WAITOK);
1780 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1781 	    SYSCTL_CHILDREN(rack_counters),
1782 	    OID_AUTO, "collapsed_win_rxt", CTLFLAG_RD,
1783 	    &rack_collapsed_win_rxt,
1784 	    "Total number of packets that were retransmitted");
1785 	rack_collapsed_win_rxt_bytes = counter_u64_alloc(M_WAITOK);
1786 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1787 	    SYSCTL_CHILDREN(rack_counters),
1788 	    OID_AUTO, "collapsed_win_bytes", CTLFLAG_RD,
1789 	    &rack_collapsed_win_rxt_bytes,
1790 	    "Total number of bytes that were retransmitted");
1791 	rack_try_scwnd = counter_u64_alloc(M_WAITOK);
1792 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1793 	    SYSCTL_CHILDREN(rack_counters),
1794 	    OID_AUTO, "tried_scwnd", CTLFLAG_RD,
1795 	    &rack_try_scwnd,
1796 	    "Total number of scwnd attempts");
1797 	COUNTER_ARRAY_ALLOC(rack_out_size, TCP_MSS_ACCT_SIZE, M_WAITOK);
1798 	SYSCTL_ADD_COUNTER_U64_ARRAY(&rack_sysctl_ctx, SYSCTL_CHILDREN(rack_sysctl_root),
1799 	    OID_AUTO, "outsize", CTLFLAG_RD,
1800 	    rack_out_size, TCP_MSS_ACCT_SIZE, "MSS send sizes");
1801 	COUNTER_ARRAY_ALLOC(rack_opts_arry, RACK_OPTS_SIZE, M_WAITOK);
1802 	SYSCTL_ADD_COUNTER_U64_ARRAY(&rack_sysctl_ctx, SYSCTL_CHILDREN(rack_sysctl_root),
1803 	    OID_AUTO, "opts", CTLFLAG_RD,
1804 	    rack_opts_arry, RACK_OPTS_SIZE, "RACK Option Stats");
1805 	SYSCTL_ADD_PROC(&rack_sysctl_ctx,
1806 	    SYSCTL_CHILDREN(rack_sysctl_root),
1807 	    OID_AUTO, "clear", CTLTYPE_UINT | CTLFLAG_RW | CTLFLAG_MPSAFE,
1808 	    &rack_clear_counter, 0, sysctl_rack_clear, "IU", "Clear counters");
1809 }
1810 
1811 static __inline int
1812 rb_map_cmp(struct rack_sendmap *b, struct rack_sendmap *a)
1813 {
1814 	if (SEQ_GEQ(b->r_start, a->r_start) &&
1815 	    SEQ_LT(b->r_start, a->r_end)) {
1816 		/*
1817 		 * The entry b is within the
1818 		 * block a. i.e.:
1819 		 * a --   |-------------|
1820 		 * b --   |----|
1821 		 * <or>
1822 		 * b --       |------|
1823 		 * <or>
1824 		 * b --       |-----------|
1825 		 */
1826 		return (0);
1827 	} else if (SEQ_GEQ(b->r_start, a->r_end)) {
1828 		/*
1829 		 * b falls as either the next
1830 		 * sequence block after a so a
1831 		 * is said to be smaller than b.
1832 		 * i.e:
1833 		 * a --   |------|
1834 		 * b --          |--------|
1835 		 * or
1836 		 * b --              |-----|
1837 		 */
1838 		return (1);
1839 	}
1840 	/*
1841 	 * Whats left is where a is
1842 	 * larger than b. i.e:
1843 	 * a --         |-------|
1844 	 * b --  |---|
1845 	 * or even possibly
1846 	 * b --   |--------------|
1847 	 */
1848 	return (-1);
1849 }
1850 
1851 RB_PROTOTYPE(rack_rb_tree_head, rack_sendmap, r_next, rb_map_cmp);
1852 RB_GENERATE(rack_rb_tree_head, rack_sendmap, r_next, rb_map_cmp);
1853 
1854 static uint32_t
1855 rc_init_window(struct tcp_rack *rack)
1856 {
1857 	uint32_t win;
1858 
1859 	if (rack->rc_init_win == 0) {
1860 		/*
1861 		 * Nothing set by the user, use the system stack
1862 		 * default.
1863 		 */
1864 		return (tcp_compute_initwnd(tcp_maxseg(rack->rc_tp)));
1865 	}
1866 	win = ctf_fixed_maxseg(rack->rc_tp) * rack->rc_init_win;
1867 	return (win);
1868 }
1869 
1870 static uint64_t
1871 rack_get_fixed_pacing_bw(struct tcp_rack *rack)
1872 {
1873 	if (IN_FASTRECOVERY(rack->rc_tp->t_flags))
1874 		return (rack->r_ctl.rc_fixed_pacing_rate_rec);
1875 	else if (rack->r_ctl.cwnd_to_use < rack->rc_tp->snd_ssthresh)
1876 		return (rack->r_ctl.rc_fixed_pacing_rate_ss);
1877 	else
1878 		return (rack->r_ctl.rc_fixed_pacing_rate_ca);
1879 }
1880 
1881 static uint64_t
1882 rack_get_bw(struct tcp_rack *rack)
1883 {
1884 	if (rack->use_fixed_rate) {
1885 		/* Return the fixed pacing rate */
1886 		return (rack_get_fixed_pacing_bw(rack));
1887 	}
1888 	if (rack->r_ctl.gp_bw == 0) {
1889 		/*
1890 		 * We have yet no b/w measurement,
1891 		 * if we have a user set initial bw
1892 		 * return it. If we don't have that and
1893 		 * we have an srtt, use the tcp IW (10) to
1894 		 * calculate a fictional b/w over the SRTT
1895 		 * which is more or less a guess. Note
1896 		 * we don't use our IW from rack on purpose
1897 		 * so if we have like IW=30, we are not
1898 		 * calculating a "huge" b/w.
1899 		 */
1900 		uint64_t bw, srtt;
1901 		if (rack->r_ctl.init_rate)
1902 			return (rack->r_ctl.init_rate);
1903 
1904 		/* Has the user set a max peak rate? */
1905 #ifdef NETFLIX_PEAKRATE
1906 		if (rack->rc_tp->t_maxpeakrate)
1907 			return (rack->rc_tp->t_maxpeakrate);
1908 #endif
1909 		/* Ok lets come up with the IW guess, if we have a srtt */
1910 		if (rack->rc_tp->t_srtt == 0) {
1911 			/*
1912 			 * Go with old pacing method
1913 			 * i.e. burst mitigation only.
1914 			 */
1915 			return (0);
1916 		}
1917 		/* Ok lets get the initial TCP win (not racks) */
1918 		bw = tcp_compute_initwnd(tcp_maxseg(rack->rc_tp));
1919 		srtt = (uint64_t)rack->rc_tp->t_srtt;
1920 		bw *= (uint64_t)USECS_IN_SECOND;
1921 		bw /= srtt;
1922 		if (rack->r_ctl.bw_rate_cap && (bw > rack->r_ctl.bw_rate_cap))
1923 			bw = rack->r_ctl.bw_rate_cap;
1924 		return (bw);
1925 	} else {
1926 		uint64_t bw;
1927 
1928 		if (rack->r_ctl.num_measurements >= RACK_REQ_AVG) {
1929 			/* Averaging is done, we can return the value */
1930 			bw = rack->r_ctl.gp_bw;
1931 		} else {
1932 			/* Still doing initial average must calculate */
1933 			bw = rack->r_ctl.gp_bw / rack->r_ctl.num_measurements;
1934 		}
1935 #ifdef NETFLIX_PEAKRATE
1936 		if ((rack->rc_tp->t_maxpeakrate) &&
1937 		    (bw > rack->rc_tp->t_maxpeakrate)) {
1938 			/* The user has set a peak rate to pace at
1939 			 * don't allow us to pace faster than that.
1940 			 */
1941 			return (rack->rc_tp->t_maxpeakrate);
1942 		}
1943 #endif
1944 		if (rack->r_ctl.bw_rate_cap && (bw > rack->r_ctl.bw_rate_cap))
1945 			bw = rack->r_ctl.bw_rate_cap;
1946 		return (bw);
1947 	}
1948 }
1949 
1950 static uint16_t
1951 rack_get_output_gain(struct tcp_rack *rack, struct rack_sendmap *rsm)
1952 {
1953 	if (rack->use_fixed_rate) {
1954 		return (100);
1955 	} else if (rack->in_probe_rtt && (rsm == NULL))
1956 		return (rack->r_ctl.rack_per_of_gp_probertt);
1957 	else if ((IN_FASTRECOVERY(rack->rc_tp->t_flags) &&
1958 		  rack->r_ctl.rack_per_of_gp_rec)) {
1959 		if (rsm) {
1960 			/* a retransmission always use the recovery rate */
1961 			return (rack->r_ctl.rack_per_of_gp_rec);
1962 		} else if (rack->rack_rec_nonrxt_use_cr) {
1963 			/* Directed to use the configured rate */
1964 			goto configured_rate;
1965 		} else if (rack->rack_no_prr &&
1966 			   (rack->r_ctl.rack_per_of_gp_rec > 100)) {
1967 			/* No PRR, lets just use the b/w estimate only */
1968 			return (100);
1969 		} else {
1970 			/*
1971 			 * Here we may have a non-retransmit but we
1972 			 * have no overrides, so just use the recovery
1973 			 * rate (prr is in effect).
1974 			 */
1975 			return (rack->r_ctl.rack_per_of_gp_rec);
1976 		}
1977 	}
1978 configured_rate:
1979 	/* For the configured rate we look at our cwnd vs the ssthresh */
1980 	if (rack->r_ctl.cwnd_to_use < rack->rc_tp->snd_ssthresh)
1981 		return (rack->r_ctl.rack_per_of_gp_ss);
1982 	else
1983 		return (rack->r_ctl.rack_per_of_gp_ca);
1984 }
1985 
1986 static void
1987 rack_log_dsack_event(struct tcp_rack *rack, uint8_t mod, uint32_t flex4, uint32_t flex5, uint32_t flex6)
1988 {
1989 	/*
1990 	 * Types of logs (mod value)
1991 	 * 1 = dsack_persists reduced by 1 via T-O or fast recovery exit.
1992 	 * 2 = a dsack round begins, persist is reset to 16.
1993 	 * 3 = a dsack round ends
1994 	 * 4 = Dsack option increases rack rtt flex5 is the srtt input, flex6 is thresh
1995 	 * 5 = Socket option set changing the control flags rc_rack_tmr_std_based, rc_rack_use_dsack
1996 	 * 6 = Final rack rtt, flex4 is srtt and flex6 is final limited thresh.
1997 	 */
1998 	if (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
1999 		union tcp_log_stackspecific log;
2000 		struct timeval tv;
2001 
2002 		memset(&log, 0, sizeof(log));
2003 		log.u_bbr.flex1 = rack->rc_rack_tmr_std_based;
2004 		log.u_bbr.flex1 <<= 1;
2005 		log.u_bbr.flex1 |= rack->rc_rack_use_dsack;
2006 		log.u_bbr.flex1 <<= 1;
2007 		log.u_bbr.flex1 |= rack->rc_dsack_round_seen;
2008 		log.u_bbr.flex2 = rack->r_ctl.dsack_round_end;
2009 		log.u_bbr.flex3 = rack->r_ctl.num_dsack;
2010 		log.u_bbr.flex4 = flex4;
2011 		log.u_bbr.flex5 = flex5;
2012 		log.u_bbr.flex6 = flex6;
2013 		log.u_bbr.flex7 = rack->r_ctl.dsack_persist;
2014 		log.u_bbr.flex8 = mod;
2015 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
2016 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
2017 		    &rack->rc_inp->inp_socket->so_rcv,
2018 		    &rack->rc_inp->inp_socket->so_snd,
2019 		    RACK_DSACK_HANDLING, 0,
2020 		    0, &log, false, &tv);
2021 	}
2022 }
2023 
2024 static void
2025 rack_log_hdwr_pacing(struct tcp_rack *rack,
2026 		     uint64_t rate, uint64_t hw_rate, int line,
2027 		     int error, uint16_t mod)
2028 {
2029 	if (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
2030 		union tcp_log_stackspecific log;
2031 		struct timeval tv;
2032 		const struct ifnet *ifp;
2033 
2034 		memset(&log, 0, sizeof(log));
2035 		log.u_bbr.flex1 = ((hw_rate >> 32) & 0x00000000ffffffff);
2036 		log.u_bbr.flex2 = (hw_rate & 0x00000000ffffffff);
2037 		if (rack->r_ctl.crte) {
2038 			ifp = rack->r_ctl.crte->ptbl->rs_ifp;
2039 		} else if (rack->rc_inp->inp_route.ro_nh &&
2040 			   rack->rc_inp->inp_route.ro_nh->nh_ifp) {
2041 			ifp = rack->rc_inp->inp_route.ro_nh->nh_ifp;
2042 		} else
2043 			ifp = NULL;
2044 		if (ifp) {
2045 			log.u_bbr.flex3 = (((uint64_t)ifp  >> 32) & 0x00000000ffffffff);
2046 			log.u_bbr.flex4 = ((uint64_t)ifp & 0x00000000ffffffff);
2047 		}
2048 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
2049 		log.u_bbr.bw_inuse = rate;
2050 		log.u_bbr.flex5 = line;
2051 		log.u_bbr.flex6 = error;
2052 		log.u_bbr.flex7 = mod;
2053 		log.u_bbr.applimited = rack->r_ctl.rc_pace_max_segs;
2054 		log.u_bbr.flex8 = rack->use_fixed_rate;
2055 		log.u_bbr.flex8 <<= 1;
2056 		log.u_bbr.flex8 |= rack->rack_hdrw_pacing;
2057 		log.u_bbr.pkts_out = rack->rc_tp->t_maxseg;
2058 		log.u_bbr.delRate = rack->r_ctl.crte_prev_rate;
2059 		if (rack->r_ctl.crte)
2060 			log.u_bbr.cur_del_rate = rack->r_ctl.crte->rate;
2061 		else
2062 			log.u_bbr.cur_del_rate = 0;
2063 		log.u_bbr.rttProp = rack->r_ctl.last_hw_bw_req;
2064 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
2065 		    &rack->rc_inp->inp_socket->so_rcv,
2066 		    &rack->rc_inp->inp_socket->so_snd,
2067 		    BBR_LOG_HDWR_PACE, 0,
2068 		    0, &log, false, &tv);
2069 	}
2070 }
2071 
2072 static uint64_t
2073 rack_get_output_bw(struct tcp_rack *rack, uint64_t bw, struct rack_sendmap *rsm, int *capped)
2074 {
2075 	/*
2076 	 * We allow rack_per_of_gp_xx to dictate our bw rate we want.
2077 	 */
2078 	uint64_t bw_est, high_rate;
2079 	uint64_t gain;
2080 
2081 	gain = (uint64_t)rack_get_output_gain(rack, rsm);
2082 	bw_est = bw * gain;
2083 	bw_est /= (uint64_t)100;
2084 	/* Never fall below the minimum (def 64kbps) */
2085 	if (bw_est < RACK_MIN_BW)
2086 		bw_est = RACK_MIN_BW;
2087 	if (rack->r_rack_hw_rate_caps) {
2088 		/* Rate caps are in place */
2089 		if (rack->r_ctl.crte != NULL) {
2090 			/* We have a hdwr rate already */
2091 			high_rate = tcp_hw_highest_rate(rack->r_ctl.crte);
2092 			if (bw_est >= high_rate) {
2093 				/* We are capping bw at the highest rate table entry */
2094 				rack_log_hdwr_pacing(rack,
2095 						     bw_est, high_rate, __LINE__,
2096 						     0, 3);
2097 				bw_est = high_rate;
2098 				if (capped)
2099 					*capped = 1;
2100 			}
2101 		} else if ((rack->rack_hdrw_pacing == 0) &&
2102 			   (rack->rack_hdw_pace_ena) &&
2103 			   (rack->rack_attempt_hdwr_pace == 0) &&
2104 			   (rack->rc_inp->inp_route.ro_nh != NULL) &&
2105 			   (rack->rc_inp->inp_route.ro_nh->nh_ifp != NULL)) {
2106 			/*
2107 			 * Special case, we have not yet attempted hardware
2108 			 * pacing, and yet we may, when we do, find out if we are
2109 			 * above the highest rate. We need to know the maxbw for the interface
2110 			 * in question (if it supports ratelimiting). We get back
2111 			 * a 0, if the interface is not found in the RL lists.
2112 			 */
2113 			high_rate = tcp_hw_highest_rate_ifp(rack->rc_inp->inp_route.ro_nh->nh_ifp, rack->rc_inp);
2114 			if (high_rate) {
2115 				/* Yep, we have a rate is it above this rate? */
2116 				if (bw_est > high_rate) {
2117 					bw_est = high_rate;
2118 					if (capped)
2119 						*capped = 1;
2120 				}
2121 			}
2122 		}
2123 	}
2124 	return (bw_est);
2125 }
2126 
2127 static void
2128 rack_log_retran_reason(struct tcp_rack *rack, struct rack_sendmap *rsm, uint32_t tsused, uint32_t thresh, int mod)
2129 {
2130 	if (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
2131 		union tcp_log_stackspecific log;
2132 		struct timeval tv;
2133 
2134 		if ((mod != 1) && (rack_verbose_logging == 0)) {
2135 			/*
2136 			 * We get 3 values currently for mod
2137 			 * 1 - We are retransmitting and this tells the reason.
2138 			 * 2 - We are clearing a dup-ack count.
2139 			 * 3 - We are incrementing a dup-ack count.
2140 			 *
2141 			 * The clear/increment are only logged
2142 			 * if you have BBverbose on.
2143 			 */
2144 			return;
2145 		}
2146 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
2147 		log.u_bbr.flex1 = tsused;
2148 		log.u_bbr.flex2 = thresh;
2149 		log.u_bbr.flex3 = rsm->r_flags;
2150 		log.u_bbr.flex4 = rsm->r_dupack;
2151 		log.u_bbr.flex5 = rsm->r_start;
2152 		log.u_bbr.flex6 = rsm->r_end;
2153 		log.u_bbr.flex8 = mod;
2154 		log.u_bbr.inhpts = tcp_in_hpts(rack->rc_inp);
2155 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
2156 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
2157 		log.u_bbr.pkts_out = rack->r_ctl.rc_out_at_rto;
2158 		log.u_bbr.delivered = rack->r_ctl.rc_snd_max_at_rto;
2159 		log.u_bbr.pacing_gain = rack->r_must_retran;
2160 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
2161 		    &rack->rc_inp->inp_socket->so_rcv,
2162 		    &rack->rc_inp->inp_socket->so_snd,
2163 		    BBR_LOG_SETTINGS_CHG, 0,
2164 		    0, &log, false, &tv);
2165 	}
2166 }
2167 
2168 static void
2169 rack_log_to_start(struct tcp_rack *rack, uint32_t cts, uint32_t to, int32_t slot, uint8_t which)
2170 {
2171 	if (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
2172 		union tcp_log_stackspecific log;
2173 		struct timeval tv;
2174 
2175 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
2176 		log.u_bbr.flex1 = rack->rc_tp->t_srtt;
2177 		log.u_bbr.flex2 = to;
2178 		log.u_bbr.flex3 = rack->r_ctl.rc_hpts_flags;
2179 		log.u_bbr.flex4 = slot;
2180 		log.u_bbr.flex5 = rack->rc_inp->inp_hptsslot;
2181 		log.u_bbr.flex6 = rack->rc_tp->t_rxtcur;
2182 		log.u_bbr.flex7 = rack->rc_in_persist;
2183 		log.u_bbr.flex8 = which;
2184 		if (rack->rack_no_prr)
2185 			log.u_bbr.pkts_out = 0;
2186 		else
2187 			log.u_bbr.pkts_out = rack->r_ctl.rc_prr_sndcnt;
2188 		log.u_bbr.inhpts = tcp_in_hpts(rack->rc_inp);
2189 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
2190 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
2191 		log.u_bbr.pkts_out = rack->r_ctl.rc_out_at_rto;
2192 		log.u_bbr.delivered = rack->r_ctl.rc_snd_max_at_rto;
2193 		log.u_bbr.pacing_gain = rack->r_must_retran;
2194 		log.u_bbr.cwnd_gain = rack->rc_has_collapsed;
2195 		log.u_bbr.lt_epoch = rack->rc_tp->t_rxtshift;
2196 		log.u_bbr.lost = rack_rto_min;
2197 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
2198 		    &rack->rc_inp->inp_socket->so_rcv,
2199 		    &rack->rc_inp->inp_socket->so_snd,
2200 		    BBR_LOG_TIMERSTAR, 0,
2201 		    0, &log, false, &tv);
2202 	}
2203 }
2204 
2205 static void
2206 rack_log_to_event(struct tcp_rack *rack, int32_t to_num, struct rack_sendmap *rsm)
2207 {
2208 	if (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
2209 		union tcp_log_stackspecific log;
2210 		struct timeval tv;
2211 
2212 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
2213 		log.u_bbr.inhpts = tcp_in_hpts(rack->rc_inp);
2214 		log.u_bbr.flex8 = to_num;
2215 		log.u_bbr.flex1 = rack->r_ctl.rc_rack_min_rtt;
2216 		log.u_bbr.flex2 = rack->rc_rack_rtt;
2217 		if (rsm == NULL)
2218 			log.u_bbr.flex3 = 0;
2219 		else
2220 			log.u_bbr.flex3 = rsm->r_end - rsm->r_start;
2221 		if (rack->rack_no_prr)
2222 			log.u_bbr.flex5 = 0;
2223 		else
2224 			log.u_bbr.flex5 = rack->r_ctl.rc_prr_sndcnt;
2225 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
2226 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
2227 		log.u_bbr.pkts_out = rack->r_ctl.rc_out_at_rto;
2228 		log.u_bbr.delivered = rack->r_ctl.rc_snd_max_at_rto;
2229 		log.u_bbr.pacing_gain = rack->r_must_retran;
2230 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
2231 		    &rack->rc_inp->inp_socket->so_rcv,
2232 		    &rack->rc_inp->inp_socket->so_snd,
2233 		    BBR_LOG_RTO, 0,
2234 		    0, &log, false, &tv);
2235 	}
2236 }
2237 
2238 static void
2239 rack_log_map_chg(struct tcpcb *tp, struct tcp_rack *rack,
2240 		 struct rack_sendmap *prev,
2241 		 struct rack_sendmap *rsm,
2242 		 struct rack_sendmap *next,
2243 		 int flag, uint32_t th_ack, int line)
2244 {
2245 	if (rack_verbose_logging && (tp->t_logstate != TCP_LOG_STATE_OFF)) {
2246 		union tcp_log_stackspecific log;
2247 		struct timeval tv;
2248 
2249 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
2250 		log.u_bbr.flex8 = flag;
2251 		log.u_bbr.inhpts = tcp_in_hpts(rack->rc_inp);
2252 		log.u_bbr.cur_del_rate = (uint64_t)prev;
2253 		log.u_bbr.delRate = (uint64_t)rsm;
2254 		log.u_bbr.rttProp = (uint64_t)next;
2255 		log.u_bbr.flex7 = 0;
2256 		if (prev) {
2257 			log.u_bbr.flex1 = prev->r_start;
2258 			log.u_bbr.flex2 = prev->r_end;
2259 			log.u_bbr.flex7 |= 0x4;
2260 		}
2261 		if (rsm) {
2262 			log.u_bbr.flex3 = rsm->r_start;
2263 			log.u_bbr.flex4 = rsm->r_end;
2264 			log.u_bbr.flex7 |= 0x2;
2265 		}
2266 		if (next) {
2267 			log.u_bbr.flex5 = next->r_start;
2268 			log.u_bbr.flex6 = next->r_end;
2269 			log.u_bbr.flex7 |= 0x1;
2270 		}
2271 		log.u_bbr.applimited = line;
2272 		log.u_bbr.pkts_out = th_ack;
2273 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
2274 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
2275 		if (rack->rack_no_prr)
2276 			log.u_bbr.lost = 0;
2277 		else
2278 			log.u_bbr.lost = rack->r_ctl.rc_prr_sndcnt;
2279 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
2280 		    &rack->rc_inp->inp_socket->so_rcv,
2281 		    &rack->rc_inp->inp_socket->so_snd,
2282 		    TCP_LOG_MAPCHG, 0,
2283 		    0, &log, false, &tv);
2284 	}
2285 }
2286 
2287 static void
2288 rack_log_rtt_upd(struct tcpcb *tp, struct tcp_rack *rack, uint32_t t, uint32_t len,
2289 		 struct rack_sendmap *rsm, int conf)
2290 {
2291 	if (tp->t_logstate != TCP_LOG_STATE_OFF) {
2292 		union tcp_log_stackspecific log;
2293 		struct timeval tv;
2294 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
2295 		log.u_bbr.inhpts = tcp_in_hpts(rack->rc_inp);
2296 		log.u_bbr.flex1 = t;
2297 		log.u_bbr.flex2 = len;
2298 		log.u_bbr.flex3 = rack->r_ctl.rc_rack_min_rtt;
2299 		log.u_bbr.flex4 = rack->r_ctl.rack_rs.rs_rtt_lowest;
2300 		log.u_bbr.flex5 = rack->r_ctl.rack_rs.rs_rtt_highest;
2301 		log.u_bbr.flex6 = rack->r_ctl.rack_rs.rs_us_rtrcnt;
2302 		log.u_bbr.flex7 = conf;
2303 		log.u_bbr.rttProp = (uint64_t)rack->r_ctl.rack_rs.rs_rtt_tot;
2304 		log.u_bbr.flex8 = rack->r_ctl.rc_rate_sample_method;
2305 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
2306 		log.u_bbr.delivered = rack->r_ctl.rack_rs.rs_us_rtrcnt;
2307 		log.u_bbr.pkts_out = rack->r_ctl.rack_rs.rs_flags;
2308 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
2309 		if (rsm) {
2310 			log.u_bbr.pkt_epoch = rsm->r_start;
2311 			log.u_bbr.lost = rsm->r_end;
2312 			log.u_bbr.cwnd_gain = rsm->r_rtr_cnt;
2313 			/* We loose any upper of the 24 bits */
2314 			log.u_bbr.pacing_gain = (uint16_t)rsm->r_flags;
2315 		} else {
2316 			/* Its a SYN */
2317 			log.u_bbr.pkt_epoch = rack->rc_tp->iss;
2318 			log.u_bbr.lost = 0;
2319 			log.u_bbr.cwnd_gain = 0;
2320 			log.u_bbr.pacing_gain = 0;
2321 		}
2322 		/* Write out general bits of interest rrs here */
2323 		log.u_bbr.use_lt_bw = rack->rc_highly_buffered;
2324 		log.u_bbr.use_lt_bw <<= 1;
2325 		log.u_bbr.use_lt_bw |= rack->forced_ack;
2326 		log.u_bbr.use_lt_bw <<= 1;
2327 		log.u_bbr.use_lt_bw |= rack->rc_gp_dyn_mul;
2328 		log.u_bbr.use_lt_bw <<= 1;
2329 		log.u_bbr.use_lt_bw |= rack->in_probe_rtt;
2330 		log.u_bbr.use_lt_bw <<= 1;
2331 		log.u_bbr.use_lt_bw |= rack->measure_saw_probe_rtt;
2332 		log.u_bbr.use_lt_bw <<= 1;
2333 		log.u_bbr.use_lt_bw |= rack->app_limited_needs_set;
2334 		log.u_bbr.use_lt_bw <<= 1;
2335 		log.u_bbr.use_lt_bw |= rack->rc_gp_filled;
2336 		log.u_bbr.use_lt_bw <<= 1;
2337 		log.u_bbr.use_lt_bw |= rack->rc_dragged_bottom;
2338 		log.u_bbr.applimited = rack->r_ctl.rc_target_probertt_flight;
2339 		log.u_bbr.epoch = rack->r_ctl.rc_time_probertt_starts;
2340 		log.u_bbr.lt_epoch = rack->r_ctl.rc_time_probertt_entered;
2341 		log.u_bbr.cur_del_rate = rack->r_ctl.rc_lower_rtt_us_cts;
2342 		log.u_bbr.delRate = rack->r_ctl.rc_gp_srtt;
2343 		log.u_bbr.bw_inuse = tcp_tv_to_usectick(&rack->r_ctl.act_rcv_time);
2344 		log.u_bbr.bw_inuse <<= 32;
2345 		if (rsm)
2346 			log.u_bbr.bw_inuse |= ((uint32_t)rsm->r_tim_lastsent[(rsm->r_rtr_cnt-1)]);
2347 		TCP_LOG_EVENTP(tp, NULL,
2348 		    &rack->rc_inp->inp_socket->so_rcv,
2349 		    &rack->rc_inp->inp_socket->so_snd,
2350 		    BBR_LOG_BBRRTT, 0,
2351 		    0, &log, false, &tv);
2352 
2353 
2354 	}
2355 }
2356 
2357 static void
2358 rack_log_rtt_sample(struct tcp_rack *rack, uint32_t rtt)
2359 {
2360 	/*
2361 	 * Log the rtt sample we are
2362 	 * applying to the srtt algorithm in
2363 	 * useconds.
2364 	 */
2365 	if (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
2366 		union tcp_log_stackspecific log;
2367 		struct timeval tv;
2368 
2369 		/* Convert our ms to a microsecond */
2370 		memset(&log, 0, sizeof(log));
2371 		log.u_bbr.flex1 = rtt;
2372 		log.u_bbr.flex2 = rack->r_ctl.ack_count;
2373 		log.u_bbr.flex3 = rack->r_ctl.sack_count;
2374 		log.u_bbr.flex4 = rack->r_ctl.sack_noextra_move;
2375 		log.u_bbr.flex5 = rack->r_ctl.sack_moved_extra;
2376 		log.u_bbr.flex6 = rack->rc_tp->t_rxtcur;
2377 		log.u_bbr.flex7 = 1;
2378 		log.u_bbr.flex8 = rack->sack_attack_disable;
2379 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
2380 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
2381 		log.u_bbr.pkts_out = rack->r_ctl.rc_out_at_rto;
2382 		log.u_bbr.delivered = rack->r_ctl.rc_snd_max_at_rto;
2383 		log.u_bbr.pacing_gain = rack->r_must_retran;
2384 		/*
2385 		 * We capture in delRate the upper 32 bits as
2386 		 * the confidence level we had declared, and the
2387 		 * lower 32 bits as the actual RTT using the arrival
2388 		 * timestamp.
2389 		 */
2390 		log.u_bbr.delRate = rack->r_ctl.rack_rs.confidence;
2391 		log.u_bbr.delRate <<= 32;
2392 		log.u_bbr.delRate |= rack->r_ctl.rack_rs.rs_us_rtt;
2393 		/* Lets capture all the things that make up t_rtxcur */
2394 		log.u_bbr.applimited = rack_rto_min;
2395 		log.u_bbr.epoch = rack_rto_max;
2396 		log.u_bbr.lt_epoch = rack->r_ctl.timer_slop;
2397 		log.u_bbr.lost = rack_rto_min;
2398 		log.u_bbr.pkt_epoch = TICKS_2_USEC(tcp_rexmit_slop);
2399 		log.u_bbr.rttProp = RACK_REXMTVAL(rack->rc_tp);
2400 		log.u_bbr.bw_inuse = rack->r_ctl.act_rcv_time.tv_sec;
2401 		log.u_bbr.bw_inuse *= HPTS_USEC_IN_SEC;
2402 		log.u_bbr.bw_inuse += rack->r_ctl.act_rcv_time.tv_usec;
2403 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
2404 		    &rack->rc_inp->inp_socket->so_rcv,
2405 		    &rack->rc_inp->inp_socket->so_snd,
2406 		    TCP_LOG_RTT, 0,
2407 		    0, &log, false, &tv);
2408 	}
2409 }
2410 
2411 static void
2412 rack_log_rtt_sample_calc(struct tcp_rack *rack, uint32_t rtt, uint32_t send_time, uint32_t ack_time, int where)
2413 {
2414 	if (rack_verbose_logging && (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF)) {
2415 		union tcp_log_stackspecific log;
2416 		struct timeval tv;
2417 
2418 		/* Convert our ms to a microsecond */
2419 		memset(&log, 0, sizeof(log));
2420 		log.u_bbr.flex1 = rtt;
2421 		log.u_bbr.flex2 = send_time;
2422 		log.u_bbr.flex3 = ack_time;
2423 		log.u_bbr.flex4 = where;
2424 		log.u_bbr.flex7 = 2;
2425 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
2426 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
2427 		    &rack->rc_inp->inp_socket->so_rcv,
2428 		    &rack->rc_inp->inp_socket->so_snd,
2429 		    TCP_LOG_RTT, 0,
2430 		    0, &log, false, &tv);
2431 	}
2432 }
2433 
2434 
2435 
2436 static inline void
2437 rack_log_progress_event(struct tcp_rack *rack, struct tcpcb *tp, uint32_t tick,  int event, int line)
2438 {
2439 	if (rack_verbose_logging && (tp->t_logstate != TCP_LOG_STATE_OFF)) {
2440 		union tcp_log_stackspecific log;
2441 		struct timeval tv;
2442 
2443 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
2444 		log.u_bbr.inhpts = tcp_in_hpts(rack->rc_inp);
2445 		log.u_bbr.flex1 = line;
2446 		log.u_bbr.flex2 = tick;
2447 		log.u_bbr.flex3 = tp->t_maxunacktime;
2448 		log.u_bbr.flex4 = tp->t_acktime;
2449 		log.u_bbr.flex8 = event;
2450 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
2451 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
2452 		log.u_bbr.pkts_out = rack->r_ctl.rc_out_at_rto;
2453 		log.u_bbr.delivered = rack->r_ctl.rc_snd_max_at_rto;
2454 		log.u_bbr.pacing_gain = rack->r_must_retran;
2455 		TCP_LOG_EVENTP(tp, NULL,
2456 		    &rack->rc_inp->inp_socket->so_rcv,
2457 		    &rack->rc_inp->inp_socket->so_snd,
2458 		    BBR_LOG_PROGRESS, 0,
2459 		    0, &log, false, &tv);
2460 	}
2461 }
2462 
2463 static void
2464 rack_log_type_bbrsnd(struct tcp_rack *rack, uint32_t len, uint32_t slot, uint32_t cts, struct timeval *tv)
2465 {
2466 	if (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
2467 		union tcp_log_stackspecific log;
2468 
2469 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
2470 		log.u_bbr.inhpts = tcp_in_hpts(rack->rc_inp);
2471 		log.u_bbr.flex1 = slot;
2472 		if (rack->rack_no_prr)
2473 			log.u_bbr.flex2 = 0;
2474 		else
2475 			log.u_bbr.flex2 = rack->r_ctl.rc_prr_sndcnt;
2476 		log.u_bbr.flex7 = (0x0000ffff & rack->r_ctl.rc_hpts_flags);
2477 		log.u_bbr.flex8 = rack->rc_in_persist;
2478 		log.u_bbr.timeStamp = cts;
2479 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
2480 		log.u_bbr.pkts_out = rack->r_ctl.rc_out_at_rto;
2481 		log.u_bbr.delivered = rack->r_ctl.rc_snd_max_at_rto;
2482 		log.u_bbr.pacing_gain = rack->r_must_retran;
2483 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
2484 		    &rack->rc_inp->inp_socket->so_rcv,
2485 		    &rack->rc_inp->inp_socket->so_snd,
2486 		    BBR_LOG_BBRSND, 0,
2487 		    0, &log, false, tv);
2488 	}
2489 }
2490 
2491 static void
2492 rack_log_doseg_done(struct tcp_rack *rack, uint32_t cts, int32_t nxt_pkt, int32_t did_out, int way_out, int nsegs)
2493 {
2494 	if (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
2495 		union tcp_log_stackspecific log;
2496 		struct timeval tv;
2497 
2498 		memset(&log, 0, sizeof(log));
2499 		log.u_bbr.flex1 = did_out;
2500 		log.u_bbr.flex2 = nxt_pkt;
2501 		log.u_bbr.flex3 = way_out;
2502 		log.u_bbr.flex4 = rack->r_ctl.rc_hpts_flags;
2503 		if (rack->rack_no_prr)
2504 			log.u_bbr.flex5 = 0;
2505 		else
2506 			log.u_bbr.flex5 = rack->r_ctl.rc_prr_sndcnt;
2507 		log.u_bbr.flex6 = nsegs;
2508 		log.u_bbr.applimited = rack->r_ctl.rc_pace_min_segs;
2509 		log.u_bbr.flex7 = rack->rc_ack_can_sendout_data;	/* Do we have ack-can-send set */
2510 		log.u_bbr.flex7 <<= 1;
2511 		log.u_bbr.flex7 |= rack->r_fast_output;	/* is fast output primed */
2512 		log.u_bbr.flex7 <<= 1;
2513 		log.u_bbr.flex7 |= rack->r_wanted_output;	/* Do we want output */
2514 		log.u_bbr.flex8 = rack->rc_in_persist;
2515 		log.u_bbr.inhpts = tcp_in_hpts(rack->rc_inp);
2516 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
2517 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
2518 		log.u_bbr.use_lt_bw = rack->r_ent_rec_ns;
2519 		log.u_bbr.use_lt_bw <<= 1;
2520 		log.u_bbr.use_lt_bw |= rack->r_might_revert;
2521 		log.u_bbr.pkts_out = rack->r_ctl.rc_out_at_rto;
2522 		log.u_bbr.delivered = rack->r_ctl.rc_snd_max_at_rto;
2523 		log.u_bbr.pacing_gain = rack->r_must_retran;
2524 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
2525 		    &rack->rc_inp->inp_socket->so_rcv,
2526 		    &rack->rc_inp->inp_socket->so_snd,
2527 		    BBR_LOG_DOSEG_DONE, 0,
2528 		    0, &log, false, &tv);
2529 	}
2530 }
2531 
2532 static void
2533 rack_log_type_pacing_sizes(struct tcpcb *tp, struct tcp_rack *rack, uint32_t arg1, uint32_t arg2, uint32_t arg3, uint8_t frm)
2534 {
2535 	if (tp->t_logstate != TCP_LOG_STATE_OFF) {
2536 		union tcp_log_stackspecific log;
2537 		struct timeval tv;
2538 
2539 		memset(&log, 0, sizeof(log));
2540 		log.u_bbr.flex1 = rack->r_ctl.rc_pace_min_segs;
2541 		log.u_bbr.flex3 = rack->r_ctl.rc_pace_max_segs;
2542 		log.u_bbr.flex4 = arg1;
2543 		log.u_bbr.flex5 = arg2;
2544 		log.u_bbr.flex6 = arg3;
2545 		log.u_bbr.flex8 = frm;
2546 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
2547 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
2548 		log.u_bbr.pkts_out = rack->r_ctl.rc_out_at_rto;
2549 		log.u_bbr.applimited = rack->r_ctl.rc_sacked;
2550 		log.u_bbr.delivered = rack->r_ctl.rc_snd_max_at_rto;
2551 		log.u_bbr.pacing_gain = rack->r_must_retran;
2552 		TCP_LOG_EVENTP(tp, NULL, &tptosocket(tp)->so_rcv,
2553 		    &tptosocket(tp)->so_snd,
2554 		    TCP_HDWR_PACE_SIZE, 0, 0, &log, false, &tv);
2555 	}
2556 }
2557 
2558 static void
2559 rack_log_type_just_return(struct tcp_rack *rack, uint32_t cts, uint32_t tlen, uint32_t slot,
2560 			  uint8_t hpts_calling, int reason, uint32_t cwnd_to_use)
2561 {
2562 	if (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
2563 		union tcp_log_stackspecific log;
2564 		struct timeval tv;
2565 
2566 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
2567 		log.u_bbr.inhpts = tcp_in_hpts(rack->rc_inp);
2568 		log.u_bbr.flex1 = slot;
2569 		log.u_bbr.flex2 = rack->r_ctl.rc_hpts_flags;
2570 		log.u_bbr.flex4 = reason;
2571 		if (rack->rack_no_prr)
2572 			log.u_bbr.flex5 = 0;
2573 		else
2574 			log.u_bbr.flex5 = rack->r_ctl.rc_prr_sndcnt;
2575 		log.u_bbr.flex7 = hpts_calling;
2576 		log.u_bbr.flex8 = rack->rc_in_persist;
2577 		log.u_bbr.lt_epoch = cwnd_to_use;
2578 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
2579 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
2580 		log.u_bbr.pkts_out = rack->r_ctl.rc_out_at_rto;
2581 		log.u_bbr.delivered = rack->r_ctl.rc_snd_max_at_rto;
2582 		log.u_bbr.pacing_gain = rack->r_must_retran;
2583 		log.u_bbr.cwnd_gain = rack->rc_has_collapsed;
2584 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
2585 		    &rack->rc_inp->inp_socket->so_rcv,
2586 		    &rack->rc_inp->inp_socket->so_snd,
2587 		    BBR_LOG_JUSTRET, 0,
2588 		    tlen, &log, false, &tv);
2589 	}
2590 }
2591 
2592 static void
2593 rack_log_to_cancel(struct tcp_rack *rack, int32_t hpts_removed, int line, uint32_t us_cts,
2594 		   struct timeval *tv, uint32_t flags_on_entry)
2595 {
2596 	if (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
2597 		union tcp_log_stackspecific log;
2598 
2599 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
2600 		log.u_bbr.inhpts = tcp_in_hpts(rack->rc_inp);
2601 		log.u_bbr.flex1 = line;
2602 		log.u_bbr.flex2 = rack->r_ctl.rc_last_output_to;
2603 		log.u_bbr.flex3 = flags_on_entry;
2604 		log.u_bbr.flex4 = us_cts;
2605 		if (rack->rack_no_prr)
2606 			log.u_bbr.flex5 = 0;
2607 		else
2608 			log.u_bbr.flex5 = rack->r_ctl.rc_prr_sndcnt;
2609 		log.u_bbr.flex6 = rack->rc_tp->t_rxtcur;
2610 		log.u_bbr.flex7 = hpts_removed;
2611 		log.u_bbr.flex8 = 1;
2612 		log.u_bbr.applimited = rack->r_ctl.rc_hpts_flags;
2613 		log.u_bbr.timeStamp = us_cts;
2614 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
2615 		log.u_bbr.pkts_out = rack->r_ctl.rc_out_at_rto;
2616 		log.u_bbr.delivered = rack->r_ctl.rc_snd_max_at_rto;
2617 		log.u_bbr.pacing_gain = rack->r_must_retran;
2618 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
2619 		    &rack->rc_inp->inp_socket->so_rcv,
2620 		    &rack->rc_inp->inp_socket->so_snd,
2621 		    BBR_LOG_TIMERCANC, 0,
2622 		    0, &log, false, tv);
2623 	}
2624 }
2625 
2626 static void
2627 rack_log_alt_to_to_cancel(struct tcp_rack *rack,
2628 			  uint32_t flex1, uint32_t flex2,
2629 			  uint32_t flex3, uint32_t flex4,
2630 			  uint32_t flex5, uint32_t flex6,
2631 			  uint16_t flex7, uint8_t mod)
2632 {
2633 	if (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
2634 		union tcp_log_stackspecific log;
2635 		struct timeval tv;
2636 
2637 		if (mod == 1) {
2638 			/* No you can't use 1, its for the real to cancel */
2639 			return;
2640 		}
2641 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
2642 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
2643 		log.u_bbr.flex1 = flex1;
2644 		log.u_bbr.flex2 = flex2;
2645 		log.u_bbr.flex3 = flex3;
2646 		log.u_bbr.flex4 = flex4;
2647 		log.u_bbr.flex5 = flex5;
2648 		log.u_bbr.flex6 = flex6;
2649 		log.u_bbr.flex7 = flex7;
2650 		log.u_bbr.flex8 = mod;
2651 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
2652 		    &rack->rc_inp->inp_socket->so_rcv,
2653 		    &rack->rc_inp->inp_socket->so_snd,
2654 		    BBR_LOG_TIMERCANC, 0,
2655 		    0, &log, false, &tv);
2656 	}
2657 }
2658 
2659 static void
2660 rack_log_to_processing(struct tcp_rack *rack, uint32_t cts, int32_t ret, int32_t timers)
2661 {
2662 	if (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
2663 		union tcp_log_stackspecific log;
2664 		struct timeval tv;
2665 
2666 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
2667 		log.u_bbr.flex1 = timers;
2668 		log.u_bbr.flex2 = ret;
2669 		log.u_bbr.flex3 = rack->r_ctl.rc_timer_exp;
2670 		log.u_bbr.flex4 = rack->r_ctl.rc_hpts_flags;
2671 		log.u_bbr.flex5 = cts;
2672 		if (rack->rack_no_prr)
2673 			log.u_bbr.flex6 = 0;
2674 		else
2675 			log.u_bbr.flex6 = rack->r_ctl.rc_prr_sndcnt;
2676 		log.u_bbr.pkts_out = rack->r_ctl.rc_out_at_rto;
2677 		log.u_bbr.delivered = rack->r_ctl.rc_snd_max_at_rto;
2678 		log.u_bbr.pacing_gain = rack->r_must_retran;
2679 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
2680 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
2681 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
2682 		    &rack->rc_inp->inp_socket->so_rcv,
2683 		    &rack->rc_inp->inp_socket->so_snd,
2684 		    BBR_LOG_TO_PROCESS, 0,
2685 		    0, &log, false, &tv);
2686 	}
2687 }
2688 
2689 static void
2690 rack_log_to_prr(struct tcp_rack *rack, int frm, int orig_cwnd, int line)
2691 {
2692 	if (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
2693 		union tcp_log_stackspecific log;
2694 		struct timeval tv;
2695 
2696 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
2697 		log.u_bbr.flex1 = rack->r_ctl.rc_prr_out;
2698 		log.u_bbr.flex2 = rack->r_ctl.rc_prr_recovery_fs;
2699 		if (rack->rack_no_prr)
2700 			log.u_bbr.flex3 = 0;
2701 		else
2702 			log.u_bbr.flex3 = rack->r_ctl.rc_prr_sndcnt;
2703 		log.u_bbr.flex4 = rack->r_ctl.rc_prr_delivered;
2704 		log.u_bbr.flex5 = rack->r_ctl.rc_sacked;
2705 		log.u_bbr.flex6 = rack->r_ctl.rc_holes_rxt;
2706 		log.u_bbr.flex7 = line;
2707 		log.u_bbr.flex8 = frm;
2708 		log.u_bbr.pkts_out = orig_cwnd;
2709 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
2710 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
2711 		log.u_bbr.use_lt_bw = rack->r_ent_rec_ns;
2712 		log.u_bbr.use_lt_bw <<= 1;
2713 		log.u_bbr.use_lt_bw |= rack->r_might_revert;
2714 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
2715 		    &rack->rc_inp->inp_socket->so_rcv,
2716 		    &rack->rc_inp->inp_socket->so_snd,
2717 		    BBR_LOG_BBRUPD, 0,
2718 		    0, &log, false, &tv);
2719 	}
2720 }
2721 
2722 #ifdef NETFLIX_EXP_DETECTION
2723 static void
2724 rack_log_sad(struct tcp_rack *rack, int event)
2725 {
2726 	if (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
2727 		union tcp_log_stackspecific log;
2728 		struct timeval tv;
2729 
2730 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
2731 		log.u_bbr.flex1 = rack->r_ctl.sack_count;
2732 		log.u_bbr.flex2 = rack->r_ctl.ack_count;
2733 		log.u_bbr.flex3 = rack->r_ctl.sack_moved_extra;
2734 		log.u_bbr.flex4 = rack->r_ctl.sack_noextra_move;
2735 		log.u_bbr.flex5 = rack->r_ctl.rc_num_maps_alloced;
2736 		log.u_bbr.flex6 = tcp_sack_to_ack_thresh;
2737 		log.u_bbr.pkts_out = tcp_sack_to_move_thresh;
2738 		log.u_bbr.lt_epoch = (tcp_force_detection << 8);
2739 		log.u_bbr.lt_epoch |= rack->do_detection;
2740 		log.u_bbr.applimited = tcp_map_minimum;
2741 		log.u_bbr.flex7 = rack->sack_attack_disable;
2742 		log.u_bbr.flex8 = event;
2743 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
2744 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
2745 		log.u_bbr.delivered = tcp_sad_decay_val;
2746 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
2747 		    &rack->rc_inp->inp_socket->so_rcv,
2748 		    &rack->rc_inp->inp_socket->so_snd,
2749 		    TCP_SAD_DETECTION, 0,
2750 		    0, &log, false, &tv);
2751 	}
2752 }
2753 #endif
2754 
2755 static void
2756 rack_counter_destroy(void)
2757 {
2758 	counter_u64_free(rack_fto_send);
2759 	counter_u64_free(rack_fto_rsm_send);
2760 	counter_u64_free(rack_nfto_resend);
2761 	counter_u64_free(rack_hw_pace_init_fail);
2762 	counter_u64_free(rack_hw_pace_lost);
2763 	counter_u64_free(rack_non_fto_send);
2764 	counter_u64_free(rack_extended_rfo);
2765 	counter_u64_free(rack_ack_total);
2766 	counter_u64_free(rack_express_sack);
2767 	counter_u64_free(rack_sack_total);
2768 	counter_u64_free(rack_move_none);
2769 	counter_u64_free(rack_move_some);
2770 	counter_u64_free(rack_sack_attacks_detected);
2771 	counter_u64_free(rack_sack_attacks_reversed);
2772 	counter_u64_free(rack_sack_used_next_merge);
2773 	counter_u64_free(rack_sack_used_prev_merge);
2774 	counter_u64_free(rack_tlp_tot);
2775 	counter_u64_free(rack_tlp_newdata);
2776 	counter_u64_free(rack_tlp_retran);
2777 	counter_u64_free(rack_tlp_retran_bytes);
2778 	counter_u64_free(rack_to_tot);
2779 	counter_u64_free(rack_saw_enobuf);
2780 	counter_u64_free(rack_saw_enobuf_hw);
2781 	counter_u64_free(rack_saw_enetunreach);
2782 	counter_u64_free(rack_hot_alloc);
2783 	counter_u64_free(rack_to_alloc);
2784 	counter_u64_free(rack_to_alloc_hard);
2785 	counter_u64_free(rack_to_alloc_emerg);
2786 	counter_u64_free(rack_to_alloc_limited);
2787 	counter_u64_free(rack_alloc_limited_conns);
2788 	counter_u64_free(rack_split_limited);
2789 	counter_u64_free(rack_multi_single_eq);
2790 	counter_u64_free(rack_proc_non_comp_ack);
2791 	counter_u64_free(rack_sack_proc_all);
2792 	counter_u64_free(rack_sack_proc_restart);
2793 	counter_u64_free(rack_sack_proc_short);
2794 	counter_u64_free(rack_sack_skipped_acked);
2795 	counter_u64_free(rack_sack_splits);
2796 	counter_u64_free(rack_input_idle_reduces);
2797 	counter_u64_free(rack_collapsed_win);
2798 	counter_u64_free(rack_collapsed_win_rxt);
2799 	counter_u64_free(rack_collapsed_win_rxt_bytes);
2800 	counter_u64_free(rack_collapsed_win_seen);
2801 	counter_u64_free(rack_try_scwnd);
2802 	counter_u64_free(rack_persists_sends);
2803 	counter_u64_free(rack_persists_acks);
2804 	counter_u64_free(rack_persists_loss);
2805 	counter_u64_free(rack_persists_lost_ends);
2806 #ifdef INVARIANTS
2807 	counter_u64_free(rack_adjust_map_bw);
2808 #endif
2809 	COUNTER_ARRAY_FREE(rack_out_size, TCP_MSS_ACCT_SIZE);
2810 	COUNTER_ARRAY_FREE(rack_opts_arry, RACK_OPTS_SIZE);
2811 }
2812 
2813 static struct rack_sendmap *
2814 rack_alloc(struct tcp_rack *rack)
2815 {
2816 	struct rack_sendmap *rsm;
2817 
2818 	/*
2819 	 * First get the top of the list it in
2820 	 * theory is the "hottest" rsm we have,
2821 	 * possibly just freed by ack processing.
2822 	 */
2823 	if (rack->rc_free_cnt > rack_free_cache) {
2824 		rsm = TAILQ_FIRST(&rack->r_ctl.rc_free);
2825 		TAILQ_REMOVE(&rack->r_ctl.rc_free, rsm, r_tnext);
2826 		counter_u64_add(rack_hot_alloc, 1);
2827 		rack->rc_free_cnt--;
2828 		return (rsm);
2829 	}
2830 	/*
2831 	 * Once we get under our free cache we probably
2832 	 * no longer have a "hot" one available. Lets
2833 	 * get one from UMA.
2834 	 */
2835 	rsm = uma_zalloc(rack_zone, M_NOWAIT);
2836 	if (rsm) {
2837 		rack->r_ctl.rc_num_maps_alloced++;
2838 		counter_u64_add(rack_to_alloc, 1);
2839 		return (rsm);
2840 	}
2841 	/*
2842 	 * Dig in to our aux rsm's (the last two) since
2843 	 * UMA failed to get us one.
2844 	 */
2845 	if (rack->rc_free_cnt) {
2846 		counter_u64_add(rack_to_alloc_emerg, 1);
2847 		rsm = TAILQ_FIRST(&rack->r_ctl.rc_free);
2848 		TAILQ_REMOVE(&rack->r_ctl.rc_free, rsm, r_tnext);
2849 		rack->rc_free_cnt--;
2850 		return (rsm);
2851 	}
2852 	return (NULL);
2853 }
2854 
2855 static struct rack_sendmap *
2856 rack_alloc_full_limit(struct tcp_rack *rack)
2857 {
2858 	if ((V_tcp_map_entries_limit > 0) &&
2859 	    (rack->do_detection == 0) &&
2860 	    (rack->r_ctl.rc_num_maps_alloced >= V_tcp_map_entries_limit)) {
2861 		counter_u64_add(rack_to_alloc_limited, 1);
2862 		if (!rack->alloc_limit_reported) {
2863 			rack->alloc_limit_reported = 1;
2864 			counter_u64_add(rack_alloc_limited_conns, 1);
2865 		}
2866 		return (NULL);
2867 	}
2868 	return (rack_alloc(rack));
2869 }
2870 
2871 /* wrapper to allocate a sendmap entry, subject to a specific limit */
2872 static struct rack_sendmap *
2873 rack_alloc_limit(struct tcp_rack *rack, uint8_t limit_type)
2874 {
2875 	struct rack_sendmap *rsm;
2876 
2877 	if (limit_type) {
2878 		/* currently there is only one limit type */
2879 		if (V_tcp_map_split_limit > 0 &&
2880 		    (rack->do_detection == 0) &&
2881 		    rack->r_ctl.rc_num_split_allocs >= V_tcp_map_split_limit) {
2882 			counter_u64_add(rack_split_limited, 1);
2883 			if (!rack->alloc_limit_reported) {
2884 				rack->alloc_limit_reported = 1;
2885 				counter_u64_add(rack_alloc_limited_conns, 1);
2886 			}
2887 			return (NULL);
2888 		}
2889 	}
2890 
2891 	/* allocate and mark in the limit type, if set */
2892 	rsm = rack_alloc(rack);
2893 	if (rsm != NULL && limit_type) {
2894 		rsm->r_limit_type = limit_type;
2895 		rack->r_ctl.rc_num_split_allocs++;
2896 	}
2897 	return (rsm);
2898 }
2899 
2900 static void
2901 rack_free(struct tcp_rack *rack, struct rack_sendmap *rsm)
2902 {
2903 	if (rsm->r_flags & RACK_APP_LIMITED) {
2904 		if (rack->r_ctl.rc_app_limited_cnt > 0) {
2905 			rack->r_ctl.rc_app_limited_cnt--;
2906 		}
2907 	}
2908 	if (rsm->r_limit_type) {
2909 		/* currently there is only one limit type */
2910 		rack->r_ctl.rc_num_split_allocs--;
2911 	}
2912 	if (rsm == rack->r_ctl.rc_first_appl) {
2913 		if (rack->r_ctl.rc_app_limited_cnt == 0)
2914 			rack->r_ctl.rc_first_appl = NULL;
2915 		else {
2916 			/* Follow the next one out */
2917 			struct rack_sendmap fe;
2918 
2919 			fe.r_start = rsm->r_nseq_appl;
2920 			rack->r_ctl.rc_first_appl = RB_FIND(rack_rb_tree_head, &rack->r_ctl.rc_mtree, &fe);
2921 		}
2922 	}
2923 	if (rsm == rack->r_ctl.rc_resend)
2924 		rack->r_ctl.rc_resend = NULL;
2925 	if (rsm == rack->r_ctl.rc_end_appl)
2926 		rack->r_ctl.rc_end_appl = NULL;
2927 	if (rack->r_ctl.rc_tlpsend == rsm)
2928 		rack->r_ctl.rc_tlpsend = NULL;
2929 	if (rack->r_ctl.rc_sacklast == rsm)
2930 		rack->r_ctl.rc_sacklast = NULL;
2931 	memset(rsm, 0, sizeof(struct rack_sendmap));
2932 	TAILQ_INSERT_HEAD(&rack->r_ctl.rc_free, rsm, r_tnext);
2933 	rack->rc_free_cnt++;
2934 }
2935 
2936 static void
2937 rack_free_trim(struct tcp_rack *rack)
2938 {
2939 	struct rack_sendmap *rsm;
2940 
2941 	/*
2942 	 * Free up all the tail entries until
2943 	 * we get our list down to the limit.
2944 	 */
2945 	while (rack->rc_free_cnt > rack_free_cache) {
2946 		rsm = TAILQ_LAST(&rack->r_ctl.rc_free, rack_head);
2947 		TAILQ_REMOVE(&rack->r_ctl.rc_free, rsm, r_tnext);
2948 		rack->rc_free_cnt--;
2949 		uma_zfree(rack_zone, rsm);
2950 	}
2951 }
2952 
2953 
2954 static uint32_t
2955 rack_get_measure_window(struct tcpcb *tp, struct tcp_rack *rack)
2956 {
2957 	uint64_t srtt, bw, len, tim;
2958 	uint32_t segsiz, def_len, minl;
2959 
2960 	segsiz = min(ctf_fixed_maxseg(tp), rack->r_ctl.rc_pace_min_segs);
2961 	def_len = rack_def_data_window * segsiz;
2962 	if (rack->rc_gp_filled == 0) {
2963 		/*
2964 		 * We have no measurement (IW is in flight?) so
2965 		 * we can only guess using our data_window sysctl
2966 		 * value (usually 20MSS).
2967 		 */
2968 		return (def_len);
2969 	}
2970 	/*
2971 	 * Now we have a number of factors to consider.
2972 	 *
2973 	 * 1) We have a desired BDP which is usually
2974 	 *    at least 2.
2975 	 * 2) We have a minimum number of rtt's usually 1 SRTT
2976 	 *    but we allow it too to be more.
2977 	 * 3) We want to make sure a measurement last N useconds (if
2978 	 *    we have set rack_min_measure_usec.
2979 	 *
2980 	 * We handle the first concern here by trying to create a data
2981 	 * window of max(rack_def_data_window, DesiredBDP). The
2982 	 * second concern we handle in not letting the measurement
2983 	 * window end normally until at least the required SRTT's
2984 	 * have gone by which is done further below in
2985 	 * rack_enough_for_measurement(). Finally the third concern
2986 	 * we also handle here by calculating how long that time
2987 	 * would take at the current BW and then return the
2988 	 * max of our first calculation and that length. Note
2989 	 * that if rack_min_measure_usec is 0, we don't deal
2990 	 * with concern 3. Also for both Concern 1 and 3 an
2991 	 * application limited period could end the measurement
2992 	 * earlier.
2993 	 *
2994 	 * So lets calculate the BDP with the "known" b/w using
2995 	 * the SRTT has our rtt and then multiply it by the
2996 	 * goal.
2997 	 */
2998 	bw = rack_get_bw(rack);
2999 	srtt = (uint64_t)tp->t_srtt;
3000 	len = bw * srtt;
3001 	len /= (uint64_t)HPTS_USEC_IN_SEC;
3002 	len *= max(1, rack_goal_bdp);
3003 	/* Now we need to round up to the nearest MSS */
3004 	len = roundup(len, segsiz);
3005 	if (rack_min_measure_usec) {
3006 		/* Now calculate our min length for this b/w */
3007 		tim = rack_min_measure_usec;
3008 		minl = (tim * bw) / (uint64_t)HPTS_USEC_IN_SEC;
3009 		if (minl == 0)
3010 			minl = 1;
3011 		minl = roundup(minl, segsiz);
3012 		if (len < minl)
3013 			len = minl;
3014 	}
3015 	/*
3016 	 * Now if we have a very small window we want
3017 	 * to attempt to get the window that is
3018 	 * as small as possible. This happens on
3019 	 * low b/w connections and we don't want to
3020 	 * span huge numbers of rtt's between measurements.
3021 	 *
3022 	 * We basically include 2 over our "MIN window" so
3023 	 * that the measurement can be shortened (possibly) by
3024 	 * an ack'ed packet.
3025 	 */
3026 	if (len < def_len)
3027 		return (max((uint32_t)len, ((MIN_GP_WIN+2) * segsiz)));
3028 	else
3029 		return (max((uint32_t)len, def_len));
3030 
3031 }
3032 
3033 static int
3034 rack_enough_for_measurement(struct tcpcb *tp, struct tcp_rack *rack, tcp_seq th_ack, uint8_t *quality)
3035 {
3036 	uint32_t tim, srtts, segsiz;
3037 
3038 	/*
3039 	 * Has enough time passed for the GP measurement to be valid?
3040 	 */
3041 	if ((tp->snd_max == tp->snd_una) ||
3042 	    (th_ack == tp->snd_max)){
3043 		/* All is acked */
3044 		*quality = RACK_QUALITY_ALLACKED;
3045 		return (1);
3046 	}
3047 	if (SEQ_LT(th_ack, tp->gput_seq)) {
3048 		/* Not enough bytes yet */
3049 		return (0);
3050 	}
3051 	segsiz = min(ctf_fixed_maxseg(tp), rack->r_ctl.rc_pace_min_segs);
3052 	if (SEQ_LT(th_ack, tp->gput_ack) &&
3053 	    ((th_ack - tp->gput_seq) < max(rc_init_window(rack), (MIN_GP_WIN * segsiz)))) {
3054 		/* Not enough bytes yet */
3055 		return (0);
3056 	}
3057 	if (rack->r_ctl.rc_first_appl &&
3058 	    (SEQ_GEQ(th_ack, rack->r_ctl.rc_first_appl->r_end))) {
3059 		/*
3060 		 * We are up to the app limited send point
3061 		 * we have to measure irrespective of the time..
3062 		 */
3063 		*quality = RACK_QUALITY_APPLIMITED;
3064 		return (1);
3065 	}
3066 	/* Now what about time? */
3067 	srtts = (rack->r_ctl.rc_gp_srtt * rack_min_srtts);
3068 	tim = tcp_tv_to_usectick(&rack->r_ctl.act_rcv_time) - tp->gput_ts;
3069 	if (tim >= srtts) {
3070 		*quality = RACK_QUALITY_HIGH;
3071 		return (1);
3072 	}
3073 	/* Nope not even a full SRTT has passed */
3074 	return (0);
3075 }
3076 
3077 static void
3078 rack_log_timely(struct tcp_rack *rack,
3079 		uint32_t logged, uint64_t cur_bw, uint64_t low_bnd,
3080 		uint64_t up_bnd, int line, uint8_t method)
3081 {
3082 	if (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
3083 		union tcp_log_stackspecific log;
3084 		struct timeval tv;
3085 
3086 		memset(&log, 0, sizeof(log));
3087 		log.u_bbr.flex1 = logged;
3088 		log.u_bbr.flex2 = rack->rc_gp_timely_inc_cnt;
3089 		log.u_bbr.flex2 <<= 4;
3090 		log.u_bbr.flex2 |= rack->rc_gp_timely_dec_cnt;
3091 		log.u_bbr.flex2 <<= 4;
3092 		log.u_bbr.flex2 |= rack->rc_gp_incr;
3093 		log.u_bbr.flex2 <<= 4;
3094 		log.u_bbr.flex2 |= rack->rc_gp_bwred;
3095 		log.u_bbr.flex3 = rack->rc_gp_incr;
3096 		log.u_bbr.flex4 = rack->r_ctl.rack_per_of_gp_ss;
3097 		log.u_bbr.flex5 = rack->r_ctl.rack_per_of_gp_ca;
3098 		log.u_bbr.flex6 = rack->r_ctl.rack_per_of_gp_rec;
3099 		log.u_bbr.flex7 = rack->rc_gp_bwred;
3100 		log.u_bbr.flex8 = method;
3101 		log.u_bbr.cur_del_rate = cur_bw;
3102 		log.u_bbr.delRate = low_bnd;
3103 		log.u_bbr.bw_inuse = up_bnd;
3104 		log.u_bbr.rttProp = rack_get_bw(rack);
3105 		log.u_bbr.pkt_epoch = line;
3106 		log.u_bbr.pkts_out = rack->r_ctl.rc_rtt_diff;
3107 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
3108 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
3109 		log.u_bbr.epoch = rack->r_ctl.rc_gp_srtt;
3110 		log.u_bbr.lt_epoch = rack->r_ctl.rc_prev_gp_srtt;
3111 		log.u_bbr.cwnd_gain = rack->rc_dragged_bottom;
3112 		log.u_bbr.cwnd_gain <<= 1;
3113 		log.u_bbr.cwnd_gain |= rack->rc_gp_saw_rec;
3114 		log.u_bbr.cwnd_gain <<= 1;
3115 		log.u_bbr.cwnd_gain |= rack->rc_gp_saw_ss;
3116 		log.u_bbr.cwnd_gain <<= 1;
3117 		log.u_bbr.cwnd_gain |= rack->rc_gp_saw_ca;
3118 		log.u_bbr.lost = rack->r_ctl.rc_loss_count;
3119 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
3120 		    &rack->rc_inp->inp_socket->so_rcv,
3121 		    &rack->rc_inp->inp_socket->so_snd,
3122 		    TCP_TIMELY_WORK, 0,
3123 		    0, &log, false, &tv);
3124 	}
3125 }
3126 
3127 static int
3128 rack_bw_can_be_raised(struct tcp_rack *rack, uint64_t cur_bw, uint64_t last_bw_est, uint16_t mult)
3129 {
3130 	/*
3131 	 * Before we increase we need to know if
3132 	 * the estimate just made was less than
3133 	 * our pacing goal (i.e. (cur_bw * mult) > last_bw_est)
3134 	 *
3135 	 * If we already are pacing at a fast enough
3136 	 * rate to push us faster there is no sense of
3137 	 * increasing.
3138 	 *
3139 	 * We first caculate our actual pacing rate (ss or ca multiplier
3140 	 * times our cur_bw).
3141 	 *
3142 	 * Then we take the last measured rate and multipy by our
3143 	 * maximum pacing overage to give us a max allowable rate.
3144 	 *
3145 	 * If our act_rate is smaller than our max_allowable rate
3146 	 * then we should increase. Else we should hold steady.
3147 	 *
3148 	 */
3149 	uint64_t act_rate, max_allow_rate;
3150 
3151 	if (rack_timely_no_stopping)
3152 		return (1);
3153 
3154 	if ((cur_bw == 0) || (last_bw_est == 0)) {
3155 		/*
3156 		 * Initial startup case or
3157 		 * everything is acked case.
3158 		 */
3159 		rack_log_timely(rack,  mult, cur_bw, 0, 0,
3160 				__LINE__, 9);
3161 		return (1);
3162 	}
3163 	if (mult <= 100) {
3164 		/*
3165 		 * We can always pace at or slightly above our rate.
3166 		 */
3167 		rack_log_timely(rack,  mult, cur_bw, 0, 0,
3168 				__LINE__, 9);
3169 		return (1);
3170 	}
3171 	act_rate = cur_bw * (uint64_t)mult;
3172 	act_rate /= 100;
3173 	max_allow_rate = last_bw_est * ((uint64_t)rack_max_per_above + (uint64_t)100);
3174 	max_allow_rate /= 100;
3175 	if (act_rate < max_allow_rate) {
3176 		/*
3177 		 * Here the rate we are actually pacing at
3178 		 * is smaller than 10% above our last measurement.
3179 		 * This means we are pacing below what we would
3180 		 * like to try to achieve (plus some wiggle room).
3181 		 */
3182 		rack_log_timely(rack,  mult, cur_bw, act_rate, max_allow_rate,
3183 				__LINE__, 9);
3184 		return (1);
3185 	} else {
3186 		/*
3187 		 * Here we are already pacing at least rack_max_per_above(10%)
3188 		 * what we are getting back. This indicates most likely
3189 		 * that we are being limited (cwnd/rwnd/app) and can't
3190 		 * get any more b/w. There is no sense of trying to
3191 		 * raise up the pacing rate its not speeding us up
3192 		 * and we already are pacing faster than we are getting.
3193 		 */
3194 		rack_log_timely(rack,  mult, cur_bw, act_rate, max_allow_rate,
3195 				__LINE__, 8);
3196 		return (0);
3197 	}
3198 }
3199 
3200 static void
3201 rack_validate_multipliers_at_or_above100(struct tcp_rack *rack)
3202 {
3203 	/*
3204 	 * When we drag bottom, we want to assure
3205 	 * that no multiplier is below 1.0, if so
3206 	 * we want to restore it to at least that.
3207 	 */
3208 	if (rack->r_ctl.rack_per_of_gp_rec  < 100) {
3209 		/* This is unlikely we usually do not touch recovery */
3210 		rack->r_ctl.rack_per_of_gp_rec = 100;
3211 	}
3212 	if (rack->r_ctl.rack_per_of_gp_ca < 100) {
3213 		rack->r_ctl.rack_per_of_gp_ca = 100;
3214 	}
3215 	if (rack->r_ctl.rack_per_of_gp_ss < 100) {
3216 		rack->r_ctl.rack_per_of_gp_ss = 100;
3217 	}
3218 }
3219 
3220 static void
3221 rack_validate_multipliers_at_or_below_100(struct tcp_rack *rack)
3222 {
3223 	if (rack->r_ctl.rack_per_of_gp_ca > 100) {
3224 		rack->r_ctl.rack_per_of_gp_ca = 100;
3225 	}
3226 	if (rack->r_ctl.rack_per_of_gp_ss > 100) {
3227 		rack->r_ctl.rack_per_of_gp_ss = 100;
3228 	}
3229 }
3230 
3231 static void
3232 rack_increase_bw_mul(struct tcp_rack *rack, int timely_says, uint64_t cur_bw, uint64_t last_bw_est, int override)
3233 {
3234 	int32_t  calc, logged, plus;
3235 
3236 	logged = 0;
3237 
3238 	if (override) {
3239 		/*
3240 		 * override is passed when we are
3241 		 * loosing b/w and making one last
3242 		 * gasp at trying to not loose out
3243 		 * to a new-reno flow.
3244 		 */
3245 		goto extra_boost;
3246 	}
3247 	/* In classic timely we boost by 5x if we have 5 increases in a row, lets not */
3248 	if (rack->rc_gp_incr &&
3249 	    ((rack->rc_gp_timely_inc_cnt + 1) >= RACK_TIMELY_CNT_BOOST)) {
3250 		/*
3251 		 * Reset and get 5 strokes more before the boost. Note
3252 		 * that the count is 0 based so we have to add one.
3253 		 */
3254 extra_boost:
3255 		plus = (uint32_t)rack_gp_increase_per * RACK_TIMELY_CNT_BOOST;
3256 		rack->rc_gp_timely_inc_cnt = 0;
3257 	} else
3258 		plus = (uint32_t)rack_gp_increase_per;
3259 	/* Must be at least 1% increase for true timely increases */
3260 	if ((plus < 1) &&
3261 	    ((rack->r_ctl.rc_rtt_diff <= 0) || (timely_says <= 0)))
3262 		plus = 1;
3263 	if (rack->rc_gp_saw_rec &&
3264 	    (rack->rc_gp_no_rec_chg == 0) &&
3265 	    rack_bw_can_be_raised(rack, cur_bw, last_bw_est,
3266 				  rack->r_ctl.rack_per_of_gp_rec)) {
3267 		/* We have been in recovery ding it too */
3268 		calc = rack->r_ctl.rack_per_of_gp_rec + plus;
3269 		if (calc > 0xffff)
3270 			calc = 0xffff;
3271 		logged |= 1;
3272 		rack->r_ctl.rack_per_of_gp_rec = (uint16_t)calc;
3273 		if (rack_per_upper_bound_ss &&
3274 		    (rack->rc_dragged_bottom == 0) &&
3275 		    (rack->r_ctl.rack_per_of_gp_rec > rack_per_upper_bound_ss))
3276 			rack->r_ctl.rack_per_of_gp_rec = rack_per_upper_bound_ss;
3277 	}
3278 	if (rack->rc_gp_saw_ca &&
3279 	    (rack->rc_gp_saw_ss == 0) &&
3280 	    rack_bw_can_be_raised(rack, cur_bw, last_bw_est,
3281 				  rack->r_ctl.rack_per_of_gp_ca)) {
3282 		/* In CA */
3283 		calc = rack->r_ctl.rack_per_of_gp_ca + plus;
3284 		if (calc > 0xffff)
3285 			calc = 0xffff;
3286 		logged |= 2;
3287 		rack->r_ctl.rack_per_of_gp_ca = (uint16_t)calc;
3288 		if (rack_per_upper_bound_ca &&
3289 		    (rack->rc_dragged_bottom == 0) &&
3290 		    (rack->r_ctl.rack_per_of_gp_ca > rack_per_upper_bound_ca))
3291 			rack->r_ctl.rack_per_of_gp_ca = rack_per_upper_bound_ca;
3292 	}
3293 	if (rack->rc_gp_saw_ss &&
3294 	    rack_bw_can_be_raised(rack, cur_bw, last_bw_est,
3295 				  rack->r_ctl.rack_per_of_gp_ss)) {
3296 		/* In SS */
3297 		calc = rack->r_ctl.rack_per_of_gp_ss + plus;
3298 		if (calc > 0xffff)
3299 			calc = 0xffff;
3300 		rack->r_ctl.rack_per_of_gp_ss = (uint16_t)calc;
3301 		if (rack_per_upper_bound_ss &&
3302 		    (rack->rc_dragged_bottom == 0) &&
3303 		    (rack->r_ctl.rack_per_of_gp_ss > rack_per_upper_bound_ss))
3304 			rack->r_ctl.rack_per_of_gp_ss = rack_per_upper_bound_ss;
3305 		logged |= 4;
3306 	}
3307 	if (logged &&
3308 	    (rack->rc_gp_incr == 0)){
3309 		/* Go into increment mode */
3310 		rack->rc_gp_incr = 1;
3311 		rack->rc_gp_timely_inc_cnt = 0;
3312 	}
3313 	if (rack->rc_gp_incr &&
3314 	    logged &&
3315 	    (rack->rc_gp_timely_inc_cnt < RACK_TIMELY_CNT_BOOST)) {
3316 		rack->rc_gp_timely_inc_cnt++;
3317 	}
3318 	rack_log_timely(rack,  logged, plus, 0, 0,
3319 			__LINE__, 1);
3320 }
3321 
3322 static uint32_t
3323 rack_get_decrease(struct tcp_rack *rack, uint32_t curper, int32_t rtt_diff)
3324 {
3325 	/*
3326 	 * norm_grad = rtt_diff / minrtt;
3327 	 * new_per = curper * (1 - B * norm_grad)
3328 	 *
3329 	 * B = rack_gp_decrease_per (default 10%)
3330 	 * rtt_dif = input var current rtt-diff
3331 	 * curper = input var current percentage
3332 	 * minrtt = from rack filter
3333 	 *
3334 	 */
3335 	uint64_t perf;
3336 
3337 	perf = (((uint64_t)curper * ((uint64_t)1000000 -
3338 		    ((uint64_t)rack_gp_decrease_per * (uint64_t)10000 *
3339 		     (((uint64_t)rtt_diff * (uint64_t)1000000)/
3340 		      (uint64_t)get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt)))/
3341 		     (uint64_t)1000000)) /
3342 		(uint64_t)1000000);
3343 	if (perf > curper) {
3344 		/* TSNH */
3345 		perf = curper - 1;
3346 	}
3347 	return ((uint32_t)perf);
3348 }
3349 
3350 static uint32_t
3351 rack_decrease_highrtt(struct tcp_rack *rack, uint32_t curper, uint32_t rtt)
3352 {
3353 	/*
3354 	 *                                   highrttthresh
3355 	 * result = curper * (1 - (B * ( 1 -  ------          ))
3356 	 *                                     gp_srtt
3357 	 *
3358 	 * B = rack_gp_decrease_per (default 10%)
3359 	 * highrttthresh = filter_min * rack_gp_rtt_maxmul
3360 	 */
3361 	uint64_t perf;
3362 	uint32_t highrttthresh;
3363 
3364 	highrttthresh = get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt) * rack_gp_rtt_maxmul;
3365 
3366 	perf = (((uint64_t)curper * ((uint64_t)1000000 -
3367 				     ((uint64_t)rack_gp_decrease_per * ((uint64_t)1000000 -
3368 					((uint64_t)highrttthresh * (uint64_t)1000000) /
3369 						    (uint64_t)rtt)) / 100)) /(uint64_t)1000000);
3370 	return (perf);
3371 }
3372 
3373 static void
3374 rack_decrease_bw_mul(struct tcp_rack *rack, int timely_says, uint32_t rtt, int32_t rtt_diff)
3375 {
3376 	uint64_t logvar, logvar2, logvar3;
3377 	uint32_t logged, new_per, ss_red, ca_red, rec_red, alt, val;
3378 
3379 	if (rack->rc_gp_incr) {
3380 		/* Turn off increment counting */
3381 		rack->rc_gp_incr = 0;
3382 		rack->rc_gp_timely_inc_cnt = 0;
3383 	}
3384 	ss_red = ca_red = rec_red = 0;
3385 	logged = 0;
3386 	/* Calculate the reduction value */
3387 	if (rtt_diff < 0) {
3388 		rtt_diff *= -1;
3389 	}
3390 	/* Must be at least 1% reduction */
3391 	if (rack->rc_gp_saw_rec && (rack->rc_gp_no_rec_chg == 0)) {
3392 		/* We have been in recovery ding it too */
3393 		if (timely_says == 2) {
3394 			new_per = rack_decrease_highrtt(rack, rack->r_ctl.rack_per_of_gp_rec, rtt);
3395 			alt = rack_get_decrease(rack, rack->r_ctl.rack_per_of_gp_rec, rtt_diff);
3396 			if (alt < new_per)
3397 				val = alt;
3398 			else
3399 				val = new_per;
3400 		} else
3401 			 val = new_per = alt = rack_get_decrease(rack, rack->r_ctl.rack_per_of_gp_rec, rtt_diff);
3402 		if (rack->r_ctl.rack_per_of_gp_rec > val) {
3403 			rec_red = (rack->r_ctl.rack_per_of_gp_rec - val);
3404 			rack->r_ctl.rack_per_of_gp_rec = (uint16_t)val;
3405 		} else {
3406 			rack->r_ctl.rack_per_of_gp_rec = rack_per_lower_bound;
3407 			rec_red = 0;
3408 		}
3409 		if (rack_per_lower_bound > rack->r_ctl.rack_per_of_gp_rec)
3410 			rack->r_ctl.rack_per_of_gp_rec = rack_per_lower_bound;
3411 		logged |= 1;
3412 	}
3413 	if (rack->rc_gp_saw_ss) {
3414 		/* Sent in SS */
3415 		if (timely_says == 2) {
3416 			new_per = rack_decrease_highrtt(rack, rack->r_ctl.rack_per_of_gp_ss, rtt);
3417 			alt = rack_get_decrease(rack, rack->r_ctl.rack_per_of_gp_rec, rtt_diff);
3418 			if (alt < new_per)
3419 				val = alt;
3420 			else
3421 				val = new_per;
3422 		} else
3423 			val = new_per = alt = rack_get_decrease(rack, rack->r_ctl.rack_per_of_gp_ss, rtt_diff);
3424 		if (rack->r_ctl.rack_per_of_gp_ss > new_per) {
3425 			ss_red = rack->r_ctl.rack_per_of_gp_ss - val;
3426 			rack->r_ctl.rack_per_of_gp_ss = (uint16_t)val;
3427 		} else {
3428 			ss_red = new_per;
3429 			rack->r_ctl.rack_per_of_gp_ss = rack_per_lower_bound;
3430 			logvar = new_per;
3431 			logvar <<= 32;
3432 			logvar |= alt;
3433 			logvar2 = (uint32_t)rtt;
3434 			logvar2 <<= 32;
3435 			logvar2 |= (uint32_t)rtt_diff;
3436 			logvar3 = rack_gp_rtt_maxmul;
3437 			logvar3 <<= 32;
3438 			logvar3 |= get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt);
3439 			rack_log_timely(rack, timely_says,
3440 					logvar2, logvar3,
3441 					logvar, __LINE__, 10);
3442 		}
3443 		if (rack_per_lower_bound > rack->r_ctl.rack_per_of_gp_ss)
3444 			rack->r_ctl.rack_per_of_gp_ss = rack_per_lower_bound;
3445 		logged |= 4;
3446 	} else if (rack->rc_gp_saw_ca) {
3447 		/* Sent in CA */
3448 		if (timely_says == 2) {
3449 			new_per = rack_decrease_highrtt(rack, rack->r_ctl.rack_per_of_gp_ca, rtt);
3450 			alt = rack_get_decrease(rack, rack->r_ctl.rack_per_of_gp_rec, rtt_diff);
3451 			if (alt < new_per)
3452 				val = alt;
3453 			else
3454 				val = new_per;
3455 		} else
3456 			val = new_per = alt = rack_get_decrease(rack, rack->r_ctl.rack_per_of_gp_ca, rtt_diff);
3457 		if (rack->r_ctl.rack_per_of_gp_ca > val) {
3458 			ca_red = rack->r_ctl.rack_per_of_gp_ca - val;
3459 			rack->r_ctl.rack_per_of_gp_ca = (uint16_t)val;
3460 		} else {
3461 			rack->r_ctl.rack_per_of_gp_ca = rack_per_lower_bound;
3462 			ca_red = 0;
3463 			logvar = new_per;
3464 			logvar <<= 32;
3465 			logvar |= alt;
3466 			logvar2 = (uint32_t)rtt;
3467 			logvar2 <<= 32;
3468 			logvar2 |= (uint32_t)rtt_diff;
3469 			logvar3 = rack_gp_rtt_maxmul;
3470 			logvar3 <<= 32;
3471 			logvar3 |= get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt);
3472 			rack_log_timely(rack, timely_says,
3473 					logvar2, logvar3,
3474 					logvar, __LINE__, 10);
3475 		}
3476 		if (rack_per_lower_bound > rack->r_ctl.rack_per_of_gp_ca)
3477 			rack->r_ctl.rack_per_of_gp_ca = rack_per_lower_bound;
3478 		logged |= 2;
3479 	}
3480 	if (rack->rc_gp_timely_dec_cnt < 0x7) {
3481 		rack->rc_gp_timely_dec_cnt++;
3482 		if (rack_timely_dec_clear &&
3483 		    (rack->rc_gp_timely_dec_cnt == rack_timely_dec_clear))
3484 			rack->rc_gp_timely_dec_cnt = 0;
3485 	}
3486 	logvar = ss_red;
3487 	logvar <<= 32;
3488 	logvar |= ca_red;
3489 	rack_log_timely(rack,  logged, rec_red, rack_per_lower_bound, logvar,
3490 			__LINE__, 2);
3491 }
3492 
3493 static void
3494 rack_log_rtt_shrinks(struct tcp_rack *rack, uint32_t us_cts,
3495 		     uint32_t rtt, uint32_t line, uint8_t reas)
3496 {
3497 	if (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
3498 		union tcp_log_stackspecific log;
3499 		struct timeval tv;
3500 
3501 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
3502 		log.u_bbr.flex1 = line;
3503 		log.u_bbr.flex2 = rack->r_ctl.rc_time_probertt_starts;
3504 		log.u_bbr.flex3 = rack->r_ctl.rc_lower_rtt_us_cts;
3505 		log.u_bbr.flex4 = rack->r_ctl.rack_per_of_gp_ss;
3506 		log.u_bbr.flex5 = rtt;
3507 		log.u_bbr.flex6 = rack->rc_highly_buffered;
3508 		log.u_bbr.flex6 <<= 1;
3509 		log.u_bbr.flex6 |= rack->forced_ack;
3510 		log.u_bbr.flex6 <<= 1;
3511 		log.u_bbr.flex6 |= rack->rc_gp_dyn_mul;
3512 		log.u_bbr.flex6 <<= 1;
3513 		log.u_bbr.flex6 |= rack->in_probe_rtt;
3514 		log.u_bbr.flex6 <<= 1;
3515 		log.u_bbr.flex6 |= rack->measure_saw_probe_rtt;
3516 		log.u_bbr.flex7 = rack->r_ctl.rack_per_of_gp_probertt;
3517 		log.u_bbr.pacing_gain = rack->r_ctl.rack_per_of_gp_ca;
3518 		log.u_bbr.cwnd_gain = rack->r_ctl.rack_per_of_gp_rec;
3519 		log.u_bbr.flex8 = reas;
3520 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
3521 		log.u_bbr.delRate = rack_get_bw(rack);
3522 		log.u_bbr.cur_del_rate = rack->r_ctl.rc_highest_us_rtt;
3523 		log.u_bbr.cur_del_rate <<= 32;
3524 		log.u_bbr.cur_del_rate |= rack->r_ctl.rc_lowest_us_rtt;
3525 		log.u_bbr.applimited = rack->r_ctl.rc_time_probertt_entered;
3526 		log.u_bbr.pkts_out = rack->r_ctl.rc_rtt_diff;
3527 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
3528 		log.u_bbr.epoch = rack->r_ctl.rc_gp_srtt;
3529 		log.u_bbr.lt_epoch = rack->r_ctl.rc_prev_gp_srtt;
3530 		log.u_bbr.pkt_epoch = rack->r_ctl.rc_lower_rtt_us_cts;
3531 		log.u_bbr.delivered = rack->r_ctl.rc_target_probertt_flight;
3532 		log.u_bbr.lost = get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt);
3533 		log.u_bbr.rttProp = us_cts;
3534 		log.u_bbr.rttProp <<= 32;
3535 		log.u_bbr.rttProp |= rack->r_ctl.rc_entry_gp_rtt;
3536 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
3537 		    &rack->rc_inp->inp_socket->so_rcv,
3538 		    &rack->rc_inp->inp_socket->so_snd,
3539 		    BBR_LOG_RTT_SHRINKS, 0,
3540 		    0, &log, false, &rack->r_ctl.act_rcv_time);
3541 	}
3542 }
3543 
3544 static void
3545 rack_set_prtt_target(struct tcp_rack *rack, uint32_t segsiz, uint32_t rtt)
3546 {
3547 	uint64_t bwdp;
3548 
3549 	bwdp = rack_get_bw(rack);
3550 	bwdp *= (uint64_t)rtt;
3551 	bwdp /= (uint64_t)HPTS_USEC_IN_SEC;
3552 	rack->r_ctl.rc_target_probertt_flight = roundup((uint32_t)bwdp, segsiz);
3553 	if (rack->r_ctl.rc_target_probertt_flight < (segsiz * rack_timely_min_segs)) {
3554 		/*
3555 		 * A window protocol must be able to have 4 packets
3556 		 * outstanding as the floor in order to function
3557 		 * (especially considering delayed ack :D).
3558 		 */
3559 		rack->r_ctl.rc_target_probertt_flight = (segsiz * rack_timely_min_segs);
3560 	}
3561 }
3562 
3563 static void
3564 rack_enter_probertt(struct tcp_rack *rack, uint32_t us_cts)
3565 {
3566 	/**
3567 	 * ProbeRTT is a bit different in rack_pacing than in
3568 	 * BBR. It is like BBR in that it uses the lowering of
3569 	 * the RTT as a signal that we saw something new and
3570 	 * counts from there for how long between. But it is
3571 	 * different in that its quite simple. It does not
3572 	 * play with the cwnd and wait until we get down
3573 	 * to N segments outstanding and hold that for
3574 	 * 200ms. Instead it just sets the pacing reduction
3575 	 * rate to a set percentage (70 by default) and hold
3576 	 * that for a number of recent GP Srtt's.
3577 	 */
3578 	uint32_t segsiz;
3579 
3580 	if (rack->rc_gp_dyn_mul == 0)
3581 		return;
3582 
3583 	if (rack->rc_tp->snd_max == rack->rc_tp->snd_una) {
3584 		/* We are idle */
3585 		return;
3586 	}
3587 	if ((rack->rc_tp->t_flags & TF_GPUTINPROG) &&
3588 	    SEQ_GT(rack->rc_tp->snd_una, rack->rc_tp->gput_seq)) {
3589 		/*
3590 		 * Stop the goodput now, the idea here is
3591 		 * that future measurements with in_probe_rtt
3592 		 * won't register if they are not greater so
3593 		 * we want to get what info (if any) is available
3594 		 * now.
3595 		 */
3596 		rack_do_goodput_measurement(rack->rc_tp, rack,
3597 					    rack->rc_tp->snd_una, __LINE__,
3598 					    RACK_QUALITY_PROBERTT);
3599 	}
3600 	rack->r_ctl.rack_per_of_gp_probertt = rack_per_of_gp_probertt;
3601 	rack->r_ctl.rc_time_probertt_entered = us_cts;
3602 	segsiz = min(ctf_fixed_maxseg(rack->rc_tp),
3603 		     rack->r_ctl.rc_pace_min_segs);
3604 	rack->in_probe_rtt = 1;
3605 	rack->measure_saw_probe_rtt = 1;
3606 	rack->r_ctl.rc_lower_rtt_us_cts = us_cts;
3607 	rack->r_ctl.rc_time_probertt_starts = 0;
3608 	rack->r_ctl.rc_entry_gp_rtt = rack->r_ctl.rc_gp_srtt;
3609 	if (rack_probertt_use_min_rtt_entry)
3610 		rack_set_prtt_target(rack, segsiz, get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt));
3611 	else
3612 		rack_set_prtt_target(rack, segsiz, rack->r_ctl.rc_gp_srtt);
3613 	rack_log_rtt_shrinks(rack,  us_cts,  get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt),
3614 			     __LINE__, RACK_RTTS_ENTERPROBE);
3615 }
3616 
3617 static void
3618 rack_exit_probertt(struct tcp_rack *rack, uint32_t us_cts)
3619 {
3620 	struct rack_sendmap *rsm;
3621 	uint32_t segsiz;
3622 
3623 	segsiz = min(ctf_fixed_maxseg(rack->rc_tp),
3624 		     rack->r_ctl.rc_pace_min_segs);
3625 	rack->in_probe_rtt = 0;
3626 	if ((rack->rc_tp->t_flags & TF_GPUTINPROG) &&
3627 	    SEQ_GT(rack->rc_tp->snd_una, rack->rc_tp->gput_seq)) {
3628 		/*
3629 		 * Stop the goodput now, the idea here is
3630 		 * that future measurements with in_probe_rtt
3631 		 * won't register if they are not greater so
3632 		 * we want to get what info (if any) is available
3633 		 * now.
3634 		 */
3635 		rack_do_goodput_measurement(rack->rc_tp, rack,
3636 					    rack->rc_tp->snd_una, __LINE__,
3637 					    RACK_QUALITY_PROBERTT);
3638 	} else if (rack->rc_tp->t_flags & TF_GPUTINPROG) {
3639 		/*
3640 		 * We don't have enough data to make a measurement.
3641 		 * So lets just stop and start here after exiting
3642 		 * probe-rtt. We probably are not interested in
3643 		 * the results anyway.
3644 		 */
3645 		rack->rc_tp->t_flags &= ~TF_GPUTINPROG;
3646 	}
3647 	/*
3648 	 * Measurements through the current snd_max are going
3649 	 * to be limited by the slower pacing rate.
3650 	 *
3651 	 * We need to mark these as app-limited so we
3652 	 * don't collapse the b/w.
3653 	 */
3654 	rsm = RB_MAX(rack_rb_tree_head, &rack->r_ctl.rc_mtree);
3655 	if (rsm && ((rsm->r_flags & RACK_APP_LIMITED) == 0)) {
3656 		if (rack->r_ctl.rc_app_limited_cnt == 0)
3657 			rack->r_ctl.rc_end_appl = rack->r_ctl.rc_first_appl = rsm;
3658 		else {
3659 			/*
3660 			 * Go out to the end app limited and mark
3661 			 * this new one as next and move the end_appl up
3662 			 * to this guy.
3663 			 */
3664 			if (rack->r_ctl.rc_end_appl)
3665 				rack->r_ctl.rc_end_appl->r_nseq_appl = rsm->r_start;
3666 			rack->r_ctl.rc_end_appl = rsm;
3667 		}
3668 		rsm->r_flags |= RACK_APP_LIMITED;
3669 		rack->r_ctl.rc_app_limited_cnt++;
3670 	}
3671 	/*
3672 	 * Now, we need to examine our pacing rate multipliers.
3673 	 * If its under 100%, we need to kick it back up to
3674 	 * 100%. We also don't let it be over our "max" above
3675 	 * the actual rate i.e. 100% + rack_clamp_atexit_prtt.
3676 	 * Note setting clamp_atexit_prtt to 0 has the effect
3677 	 * of setting CA/SS to 100% always at exit (which is
3678 	 * the default behavior).
3679 	 */
3680 	if (rack_probertt_clear_is) {
3681 		rack->rc_gp_incr = 0;
3682 		rack->rc_gp_bwred = 0;
3683 		rack->rc_gp_timely_inc_cnt = 0;
3684 		rack->rc_gp_timely_dec_cnt = 0;
3685 	}
3686 	/* Do we do any clamping at exit? */
3687 	if (rack->rc_highly_buffered && rack_atexit_prtt_hbp) {
3688 		rack->r_ctl.rack_per_of_gp_ca = rack_atexit_prtt_hbp;
3689 		rack->r_ctl.rack_per_of_gp_ss = rack_atexit_prtt_hbp;
3690 	}
3691 	if ((rack->rc_highly_buffered == 0) && rack_atexit_prtt) {
3692 		rack->r_ctl.rack_per_of_gp_ca = rack_atexit_prtt;
3693 		rack->r_ctl.rack_per_of_gp_ss = rack_atexit_prtt;
3694 	}
3695 	/*
3696 	 * Lets set rtt_diff to 0, so that we will get a "boost"
3697 	 * after exiting.
3698 	 */
3699 	rack->r_ctl.rc_rtt_diff = 0;
3700 
3701 	/* Clear all flags so we start fresh */
3702 	rack->rc_tp->t_bytes_acked = 0;
3703 	rack->rc_tp->ccv->flags &= ~CCF_ABC_SENTAWND;
3704 	/*
3705 	 * If configured to, set the cwnd and ssthresh to
3706 	 * our targets.
3707 	 */
3708 	if (rack_probe_rtt_sets_cwnd) {
3709 		uint64_t ebdp;
3710 		uint32_t setto;
3711 
3712 		/* Set ssthresh so we get into CA once we hit our target */
3713 		if (rack_probertt_use_min_rtt_exit == 1) {
3714 			/* Set to min rtt */
3715 			rack_set_prtt_target(rack, segsiz,
3716 					     get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt));
3717 		} else if (rack_probertt_use_min_rtt_exit == 2) {
3718 			/* Set to current gp rtt */
3719 			rack_set_prtt_target(rack, segsiz,
3720 					     rack->r_ctl.rc_gp_srtt);
3721 		} else if (rack_probertt_use_min_rtt_exit == 3) {
3722 			/* Set to entry gp rtt */
3723 			rack_set_prtt_target(rack, segsiz,
3724 					     rack->r_ctl.rc_entry_gp_rtt);
3725 		} else {
3726 			uint64_t sum;
3727 			uint32_t setval;
3728 
3729 			sum = rack->r_ctl.rc_entry_gp_rtt;
3730 			sum *= 10;
3731 			sum /= (uint64_t)(max(1, rack->r_ctl.rc_gp_srtt));
3732 			if (sum >= 20) {
3733 				/*
3734 				 * A highly buffered path needs
3735 				 * cwnd space for timely to work.
3736 				 * Lets set things up as if
3737 				 * we are heading back here again.
3738 				 */
3739 				setval = rack->r_ctl.rc_entry_gp_rtt;
3740 			} else if (sum >= 15) {
3741 				/*
3742 				 * Lets take the smaller of the
3743 				 * two since we are just somewhat
3744 				 * buffered.
3745 				 */
3746 				setval = rack->r_ctl.rc_gp_srtt;
3747 				if (setval > rack->r_ctl.rc_entry_gp_rtt)
3748 					setval = rack->r_ctl.rc_entry_gp_rtt;
3749 			} else {
3750 				/*
3751 				 * Here we are not highly buffered
3752 				 * and should pick the min we can to
3753 				 * keep from causing loss.
3754 				 */
3755 				setval = get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt);
3756 			}
3757 			rack_set_prtt_target(rack, segsiz,
3758 					     setval);
3759 		}
3760 		if (rack_probe_rtt_sets_cwnd > 1) {
3761 			/* There is a percentage here to boost */
3762 			ebdp = rack->r_ctl.rc_target_probertt_flight;
3763 			ebdp *= rack_probe_rtt_sets_cwnd;
3764 			ebdp /= 100;
3765 			setto = rack->r_ctl.rc_target_probertt_flight + ebdp;
3766 		} else
3767 			setto = rack->r_ctl.rc_target_probertt_flight;
3768 		rack->rc_tp->snd_cwnd = roundup(setto, segsiz);
3769 		if (rack->rc_tp->snd_cwnd < (segsiz * rack_timely_min_segs)) {
3770 			/* Enforce a min */
3771 			rack->rc_tp->snd_cwnd = segsiz * rack_timely_min_segs;
3772 		}
3773 		/* If we set in the cwnd also set the ssthresh point so we are in CA */
3774 		rack->rc_tp->snd_ssthresh = (rack->rc_tp->snd_cwnd - 1);
3775 	}
3776 	rack_log_rtt_shrinks(rack,  us_cts,
3777 			     get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt),
3778 			     __LINE__, RACK_RTTS_EXITPROBE);
3779 	/* Clear times last so log has all the info */
3780 	rack->r_ctl.rc_probertt_sndmax_atexit = rack->rc_tp->snd_max;
3781 	rack->r_ctl.rc_time_probertt_entered = us_cts;
3782 	rack->r_ctl.rc_time_probertt_starts = rack->r_ctl.rc_lower_rtt_us_cts = us_cts;
3783 	rack->r_ctl.rc_time_of_last_probertt = us_cts;
3784 }
3785 
3786 static void
3787 rack_check_probe_rtt(struct tcp_rack *rack, uint32_t us_cts)
3788 {
3789 	/* Check in on probe-rtt */
3790 	if (rack->rc_gp_filled == 0) {
3791 		/* We do not do p-rtt unless we have gp measurements */
3792 		return;
3793 	}
3794 	if (rack->in_probe_rtt) {
3795 		uint64_t no_overflow;
3796 		uint32_t endtime, must_stay;
3797 
3798 		if (rack->r_ctl.rc_went_idle_time &&
3799 		    ((us_cts - rack->r_ctl.rc_went_idle_time) > rack_min_probertt_hold)) {
3800 			/*
3801 			 * We went idle during prtt, just exit now.
3802 			 */
3803 			rack_exit_probertt(rack, us_cts);
3804 		} else if (rack_probe_rtt_safety_val &&
3805 		    TSTMP_GT(us_cts, rack->r_ctl.rc_time_probertt_entered) &&
3806 		    ((us_cts - rack->r_ctl.rc_time_probertt_entered) > rack_probe_rtt_safety_val)) {
3807 			/*
3808 			 * Probe RTT safety value triggered!
3809 			 */
3810 			rack_log_rtt_shrinks(rack,  us_cts,
3811 					     get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt),
3812 					     __LINE__, RACK_RTTS_SAFETY);
3813 			rack_exit_probertt(rack, us_cts);
3814 		}
3815 		/* Calculate the max we will wait */
3816 		endtime = rack->r_ctl.rc_time_probertt_entered + (rack->r_ctl.rc_gp_srtt * rack_max_drain_wait);
3817 		if (rack->rc_highly_buffered)
3818 			endtime += (rack->r_ctl.rc_gp_srtt * rack_max_drain_hbp);
3819 		/* Calculate the min we must wait */
3820 		must_stay = rack->r_ctl.rc_time_probertt_entered + (rack->r_ctl.rc_gp_srtt * rack_must_drain);
3821 		if ((ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked) > rack->r_ctl.rc_target_probertt_flight) &&
3822 		    TSTMP_LT(us_cts, endtime)) {
3823 			uint32_t calc;
3824 			/* Do we lower more? */
3825 no_exit:
3826 			if (TSTMP_GT(us_cts, rack->r_ctl.rc_time_probertt_entered))
3827 				calc = us_cts - rack->r_ctl.rc_time_probertt_entered;
3828 			else
3829 				calc = 0;
3830 			calc /= max(rack->r_ctl.rc_gp_srtt, 1);
3831 			if (calc) {
3832 				/* Maybe */
3833 				calc *= rack_per_of_gp_probertt_reduce;
3834 				rack->r_ctl.rack_per_of_gp_probertt = rack_per_of_gp_probertt - calc;
3835 				/* Limit it too */
3836 				if (rack->r_ctl.rack_per_of_gp_probertt < rack_per_of_gp_lowthresh)
3837 					rack->r_ctl.rack_per_of_gp_probertt = rack_per_of_gp_lowthresh;
3838 			}
3839 			/* We must reach target or the time set */
3840 			return;
3841 		}
3842 		if (rack->r_ctl.rc_time_probertt_starts == 0) {
3843 			if ((TSTMP_LT(us_cts, must_stay) &&
3844 			     rack->rc_highly_buffered) ||
3845 			     (ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked) >
3846 			      rack->r_ctl.rc_target_probertt_flight)) {
3847 				/* We are not past the must_stay time */
3848 				goto no_exit;
3849 			}
3850 			rack_log_rtt_shrinks(rack,  us_cts,
3851 					     get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt),
3852 					     __LINE__, RACK_RTTS_REACHTARGET);
3853 			rack->r_ctl.rc_time_probertt_starts = us_cts;
3854 			if (rack->r_ctl.rc_time_probertt_starts == 0)
3855 				rack->r_ctl.rc_time_probertt_starts = 1;
3856 			/* Restore back to our rate we want to pace at in prtt */
3857 			rack->r_ctl.rack_per_of_gp_probertt = rack_per_of_gp_probertt;
3858 		}
3859 		/*
3860 		 * Setup our end time, some number of gp_srtts plus 200ms.
3861 		 */
3862 		no_overflow = ((uint64_t)rack->r_ctl.rc_gp_srtt *
3863 			       (uint64_t)rack_probertt_gpsrtt_cnt_mul);
3864 		if (rack_probertt_gpsrtt_cnt_div)
3865 			endtime = (uint32_t)(no_overflow / (uint64_t)rack_probertt_gpsrtt_cnt_div);
3866 		else
3867 			endtime = 0;
3868 		endtime += rack_min_probertt_hold;
3869 		endtime += rack->r_ctl.rc_time_probertt_starts;
3870 		if (TSTMP_GEQ(us_cts,  endtime)) {
3871 			/* yes, exit probertt */
3872 			rack_exit_probertt(rack, us_cts);
3873 		}
3874 
3875 	} else if ((us_cts - rack->r_ctl.rc_lower_rtt_us_cts) >= rack_time_between_probertt) {
3876 		/* Go into probertt, its been too long since we went lower */
3877 		rack_enter_probertt(rack, us_cts);
3878 	}
3879 }
3880 
3881 static void
3882 rack_update_multiplier(struct tcp_rack *rack, int32_t timely_says, uint64_t last_bw_est,
3883 		       uint32_t rtt, int32_t rtt_diff)
3884 {
3885 	uint64_t cur_bw, up_bnd, low_bnd, subfr;
3886 	uint32_t losses;
3887 
3888 	if ((rack->rc_gp_dyn_mul == 0) ||
3889 	    (rack->use_fixed_rate) ||
3890 	    (rack->in_probe_rtt) ||
3891 	    (rack->rc_always_pace == 0)) {
3892 		/* No dynamic GP multiplier in play */
3893 		return;
3894 	}
3895 	losses = rack->r_ctl.rc_loss_count - rack->r_ctl.rc_loss_at_start;
3896 	cur_bw = rack_get_bw(rack);
3897 	/* Calculate our up and down range */
3898 	up_bnd = rack->r_ctl.last_gp_comp_bw * (uint64_t)rack_gp_per_bw_mul_up;
3899 	up_bnd /= 100;
3900 	up_bnd += rack->r_ctl.last_gp_comp_bw;
3901 
3902 	subfr = (uint64_t)rack->r_ctl.last_gp_comp_bw * (uint64_t)rack_gp_per_bw_mul_down;
3903 	subfr /= 100;
3904 	low_bnd = rack->r_ctl.last_gp_comp_bw - subfr;
3905 	if ((timely_says == 2) && (rack->r_ctl.rc_no_push_at_mrtt)) {
3906 		/*
3907 		 * This is the case where our RTT is above
3908 		 * the max target and we have been configured
3909 		 * to just do timely no bonus up stuff in that case.
3910 		 *
3911 		 * There are two configurations, set to 1, and we
3912 		 * just do timely if we are over our max. If its
3913 		 * set above 1 then we slam the multipliers down
3914 		 * to 100 and then decrement per timely.
3915 		 */
3916 		rack_log_timely(rack,  timely_says, cur_bw, low_bnd, up_bnd,
3917 				__LINE__, 3);
3918 		if (rack->r_ctl.rc_no_push_at_mrtt > 1)
3919 			rack_validate_multipliers_at_or_below_100(rack);
3920 		rack_decrease_bw_mul(rack, timely_says, rtt, rtt_diff);
3921 	} else if ((last_bw_est < low_bnd) && !losses) {
3922 		/*
3923 		 * We are decreasing this is a bit complicated this
3924 		 * means we are loosing ground. This could be
3925 		 * because another flow entered and we are competing
3926 		 * for b/w with it. This will push the RTT up which
3927 		 * makes timely unusable unless we want to get shoved
3928 		 * into a corner and just be backed off (the age
3929 		 * old problem with delay based CC).
3930 		 *
3931 		 * On the other hand if it was a route change we
3932 		 * would like to stay somewhat contained and not
3933 		 * blow out the buffers.
3934 		 */
3935 		rack_log_timely(rack,  timely_says, cur_bw, low_bnd, up_bnd,
3936 				__LINE__, 3);
3937 		rack->r_ctl.last_gp_comp_bw = cur_bw;
3938 		if (rack->rc_gp_bwred == 0) {
3939 			/* Go into reduction counting */
3940 			rack->rc_gp_bwred = 1;
3941 			rack->rc_gp_timely_dec_cnt = 0;
3942 		}
3943 		if ((rack->rc_gp_timely_dec_cnt < rack_timely_max_push_drop) ||
3944 		    (timely_says == 0)) {
3945 			/*
3946 			 * Push another time with a faster pacing
3947 			 * to try to gain back (we include override to
3948 			 * get a full raise factor).
3949 			 */
3950 			if ((rack->rc_gp_saw_ca && rack->r_ctl.rack_per_of_gp_ca <= rack_down_raise_thresh) ||
3951 			    (rack->rc_gp_saw_ss && rack->r_ctl.rack_per_of_gp_ss <= rack_down_raise_thresh) ||
3952 			    (timely_says == 0) ||
3953 			    (rack_down_raise_thresh == 0)) {
3954 				/*
3955 				 * Do an override up in b/w if we were
3956 				 * below the threshold or if the threshold
3957 				 * is zero we always do the raise.
3958 				 */
3959 				rack_increase_bw_mul(rack, timely_says, cur_bw, last_bw_est, 1);
3960 			} else {
3961 				/* Log it stays the same */
3962 				rack_log_timely(rack,  0, last_bw_est, low_bnd, 0,
3963 						__LINE__, 11);
3964 			}
3965 			rack->rc_gp_timely_dec_cnt++;
3966 			/* We are not incrementing really no-count */
3967 			rack->rc_gp_incr = 0;
3968 			rack->rc_gp_timely_inc_cnt = 0;
3969 		} else {
3970 			/*
3971 			 * Lets just use the RTT
3972 			 * information and give up
3973 			 * pushing.
3974 			 */
3975 			goto use_timely;
3976 		}
3977 	} else if ((timely_says != 2) &&
3978 		    !losses &&
3979 		    (last_bw_est > up_bnd)) {
3980 		/*
3981 		 * We are increasing b/w lets keep going, updating
3982 		 * our b/w and ignoring any timely input, unless
3983 		 * of course we are at our max raise (if there is one).
3984 		 */
3985 
3986 		rack_log_timely(rack,  timely_says, cur_bw, low_bnd, up_bnd,
3987 				__LINE__, 3);
3988 		rack->r_ctl.last_gp_comp_bw = cur_bw;
3989 		if (rack->rc_gp_saw_ss &&
3990 		    rack_per_upper_bound_ss &&
3991 		     (rack->r_ctl.rack_per_of_gp_ss == rack_per_upper_bound_ss)) {
3992 			    /*
3993 			     * In cases where we can't go higher
3994 			     * we should just use timely.
3995 			     */
3996 			    goto use_timely;
3997 		}
3998 		if (rack->rc_gp_saw_ca &&
3999 		    rack_per_upper_bound_ca &&
4000 		    (rack->r_ctl.rack_per_of_gp_ca == rack_per_upper_bound_ca)) {
4001 			    /*
4002 			     * In cases where we can't go higher
4003 			     * we should just use timely.
4004 			     */
4005 			    goto use_timely;
4006 		}
4007 		rack->rc_gp_bwred = 0;
4008 		rack->rc_gp_timely_dec_cnt = 0;
4009 		/* You get a set number of pushes if timely is trying to reduce */
4010 		if ((rack->rc_gp_incr < rack_timely_max_push_rise) || (timely_says == 0)) {
4011 			rack_increase_bw_mul(rack, timely_says, cur_bw, last_bw_est, 0);
4012 		} else {
4013 			/* Log it stays the same */
4014 			rack_log_timely(rack,  0, last_bw_est, up_bnd, 0,
4015 			    __LINE__, 12);
4016 		}
4017 		return;
4018 	} else {
4019 		/*
4020 		 * We are staying between the lower and upper range bounds
4021 		 * so use timely to decide.
4022 		 */
4023 		rack_log_timely(rack,  timely_says, cur_bw, low_bnd, up_bnd,
4024 				__LINE__, 3);
4025 use_timely:
4026 		if (timely_says) {
4027 			rack->rc_gp_incr = 0;
4028 			rack->rc_gp_timely_inc_cnt = 0;
4029 			if ((rack->rc_gp_timely_dec_cnt < rack_timely_max_push_drop) &&
4030 			    !losses &&
4031 			    (last_bw_est < low_bnd)) {
4032 				/* We are loosing ground */
4033 				rack_increase_bw_mul(rack, timely_says, cur_bw, last_bw_est, 0);
4034 				rack->rc_gp_timely_dec_cnt++;
4035 				/* We are not incrementing really no-count */
4036 				rack->rc_gp_incr = 0;
4037 				rack->rc_gp_timely_inc_cnt = 0;
4038 			} else
4039 				rack_decrease_bw_mul(rack, timely_says, rtt, rtt_diff);
4040 		} else {
4041 			rack->rc_gp_bwred = 0;
4042 			rack->rc_gp_timely_dec_cnt = 0;
4043 			rack_increase_bw_mul(rack, timely_says, cur_bw, last_bw_est, 0);
4044 		}
4045 	}
4046 }
4047 
4048 static int32_t
4049 rack_make_timely_judgement(struct tcp_rack *rack, uint32_t rtt, int32_t rtt_diff, uint32_t prev_rtt)
4050 {
4051 	int32_t timely_says;
4052 	uint64_t log_mult, log_rtt_a_diff;
4053 
4054 	log_rtt_a_diff = rtt;
4055 	log_rtt_a_diff <<= 32;
4056 	log_rtt_a_diff |= (uint32_t)rtt_diff;
4057 	if (rtt >= (get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt) *
4058 		    rack_gp_rtt_maxmul)) {
4059 		/* Reduce the b/w multiplier */
4060 		timely_says = 2;
4061 		log_mult = get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt) * rack_gp_rtt_maxmul;
4062 		log_mult <<= 32;
4063 		log_mult |= prev_rtt;
4064 		rack_log_timely(rack,  timely_says, log_mult,
4065 				get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt),
4066 				log_rtt_a_diff, __LINE__, 4);
4067 	} else if (rtt <= (get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt) +
4068 			   ((get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt) * rack_gp_rtt_minmul) /
4069 			    max(rack_gp_rtt_mindiv , 1)))) {
4070 		/* Increase the b/w multiplier */
4071 		log_mult = get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt) +
4072 			((get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt) * rack_gp_rtt_minmul) /
4073 			 max(rack_gp_rtt_mindiv , 1));
4074 		log_mult <<= 32;
4075 		log_mult |= prev_rtt;
4076 		timely_says = 0;
4077 		rack_log_timely(rack,  timely_says, log_mult ,
4078 				get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt),
4079 				log_rtt_a_diff, __LINE__, 5);
4080 	} else {
4081 		/*
4082 		 * Use a gradient to find it the timely gradient
4083 		 * is:
4084 		 * grad = rc_rtt_diff / min_rtt;
4085 		 *
4086 		 * anything below or equal to 0 will be
4087 		 * a increase indication. Anything above
4088 		 * zero is a decrease. Note we take care
4089 		 * of the actual gradient calculation
4090 		 * in the reduction (its not needed for
4091 		 * increase).
4092 		 */
4093 		log_mult = prev_rtt;
4094 		if (rtt_diff <= 0) {
4095 			/*
4096 			 * Rttdiff is less than zero, increase the
4097 			 * b/w multiplier (its 0 or negative)
4098 			 */
4099 			timely_says = 0;
4100 			rack_log_timely(rack,  timely_says, log_mult,
4101 					get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt), log_rtt_a_diff, __LINE__, 6);
4102 		} else {
4103 			/* Reduce the b/w multiplier */
4104 			timely_says = 1;
4105 			rack_log_timely(rack,  timely_says, log_mult,
4106 					get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt), log_rtt_a_diff, __LINE__, 7);
4107 		}
4108 	}
4109 	return (timely_says);
4110 }
4111 
4112 static void
4113 rack_do_goodput_measurement(struct tcpcb *tp, struct tcp_rack *rack,
4114 			    tcp_seq th_ack, int line, uint8_t quality)
4115 {
4116 	uint64_t tim, bytes_ps, ltim, stim, utim;
4117 	uint32_t segsiz, bytes, reqbytes, us_cts;
4118 	int32_t gput, new_rtt_diff, timely_says;
4119 	uint64_t  resid_bw, subpart = 0, addpart = 0, srtt;
4120 	int did_add = 0;
4121 
4122 	us_cts = tcp_tv_to_usectick(&rack->r_ctl.act_rcv_time);
4123 	segsiz = min(ctf_fixed_maxseg(tp), rack->r_ctl.rc_pace_min_segs);
4124 	if (TSTMP_GEQ(us_cts, tp->gput_ts))
4125 		tim = us_cts - tp->gput_ts;
4126 	else
4127 		tim = 0;
4128 	if (rack->r_ctl.rc_gp_cumack_ts > rack->r_ctl.rc_gp_output_ts)
4129 		stim = rack->r_ctl.rc_gp_cumack_ts - rack->r_ctl.rc_gp_output_ts;
4130 	else
4131 		stim = 0;
4132 	/*
4133 	 * Use the larger of the send time or ack time. This prevents us
4134 	 * from being influenced by ack artifacts to come up with too
4135 	 * high of measurement. Note that since we are spanning over many more
4136 	 * bytes in most of our measurements hopefully that is less likely to
4137 	 * occur.
4138 	 */
4139 	if (tim > stim)
4140 		utim = max(tim, 1);
4141 	else
4142 		utim = max(stim, 1);
4143 	/* Lets get a msec time ltim too for the old stuff */
4144 	ltim = max(1, (utim / HPTS_USEC_IN_MSEC));
4145 	gput = (((uint64_t) (th_ack - tp->gput_seq)) << 3) / ltim;
4146 	reqbytes = min(rc_init_window(rack), (MIN_GP_WIN * segsiz));
4147 	if ((tim == 0) && (stim == 0)) {
4148 		/*
4149 		 * Invalid measurement time, maybe
4150 		 * all on one ack/one send?
4151 		 */
4152 		bytes = 0;
4153 		bytes_ps = 0;
4154 		rack_log_pacing_delay_calc(rack, bytes_ps, reqbytes,
4155 					   0, 0, 0, 10, __LINE__, NULL, quality);
4156 		goto skip_measurement;
4157 	}
4158 	if (rack->r_ctl.rc_gp_lowrtt == 0xffffffff) {
4159 		/* We never made a us_rtt measurement? */
4160 		bytes = 0;
4161 		bytes_ps = 0;
4162 		rack_log_pacing_delay_calc(rack, bytes_ps, reqbytes,
4163 					   0, 0, 0, 10, __LINE__, NULL, quality);
4164 		goto skip_measurement;
4165 	}
4166 	/*
4167 	 * Calculate the maximum possible b/w this connection
4168 	 * could have. We base our calculation on the lowest
4169 	 * rtt we have seen during the measurement and the
4170 	 * largest rwnd the client has given us in that time. This
4171 	 * forms a BDP that is the maximum that we could ever
4172 	 * get to the client. Anything larger is not valid.
4173 	 *
4174 	 * I originally had code here that rejected measurements
4175 	 * where the time was less than 1/2 the latest us_rtt.
4176 	 * But after thinking on that I realized its wrong since
4177 	 * say you had a 150Mbps or even 1Gbps link, and you
4178 	 * were a long way away.. example I am in Europe (100ms rtt)
4179 	 * talking to my 1Gbps link in S.C. Now measuring say 150,000
4180 	 * bytes my time would be 1.2ms, and yet my rtt would say
4181 	 * the measurement was invalid the time was < 50ms. The
4182 	 * same thing is true for 150Mb (8ms of time).
4183 	 *
4184 	 * A better way I realized is to look at what the maximum
4185 	 * the connection could possibly do. This is gated on
4186 	 * the lowest RTT we have seen and the highest rwnd.
4187 	 * We should in theory never exceed that, if we are
4188 	 * then something on the path is storing up packets
4189 	 * and then feeding them all at once to our endpoint
4190 	 * messing up our measurement.
4191 	 */
4192 	rack->r_ctl.last_max_bw = rack->r_ctl.rc_gp_high_rwnd;
4193 	rack->r_ctl.last_max_bw *= HPTS_USEC_IN_SEC;
4194 	rack->r_ctl.last_max_bw /= rack->r_ctl.rc_gp_lowrtt;
4195 	if (SEQ_LT(th_ack, tp->gput_seq)) {
4196 		/* No measurement can be made */
4197 		bytes = 0;
4198 		bytes_ps = 0;
4199 		rack_log_pacing_delay_calc(rack, bytes_ps, reqbytes,
4200 					   0, 0, 0, 10, __LINE__, NULL, quality);
4201 		goto skip_measurement;
4202 	} else
4203 		bytes = (th_ack - tp->gput_seq);
4204 	bytes_ps = (uint64_t)bytes;
4205 	/*
4206 	 * Don't measure a b/w for pacing unless we have gotten at least
4207 	 * an initial windows worth of data in this measurement interval.
4208 	 *
4209 	 * Small numbers of bytes get badly influenced by delayed ack and
4210 	 * other artifacts. Note we take the initial window or our
4211 	 * defined minimum GP (defaulting to 10 which hopefully is the
4212 	 * IW).
4213 	 */
4214 	if (rack->rc_gp_filled == 0) {
4215 		/*
4216 		 * The initial estimate is special. We
4217 		 * have blasted out an IW worth of packets
4218 		 * without a real valid ack ts results. We
4219 		 * then setup the app_limited_needs_set flag,
4220 		 * this should get the first ack in (probably 2
4221 		 * MSS worth) to be recorded as the timestamp.
4222 		 * We thus allow a smaller number of bytes i.e.
4223 		 * IW - 2MSS.
4224 		 */
4225 		reqbytes -= (2 * segsiz);
4226 		/* Also lets fill previous for our first measurement to be neutral */
4227 		rack->r_ctl.rc_prev_gp_srtt = rack->r_ctl.rc_gp_srtt;
4228 	}
4229 	if ((bytes_ps < reqbytes) || rack->app_limited_needs_set) {
4230 		rack_log_pacing_delay_calc(rack, bytes_ps, reqbytes,
4231 					   rack->r_ctl.rc_app_limited_cnt,
4232 					   0, 0, 10, __LINE__, NULL, quality);
4233 		goto skip_measurement;
4234 	}
4235 	/*
4236 	 * We now need to calculate the Timely like status so
4237 	 * we can update (possibly) the b/w multipliers.
4238 	 */
4239 	new_rtt_diff = (int32_t)rack->r_ctl.rc_gp_srtt - (int32_t)rack->r_ctl.rc_prev_gp_srtt;
4240 	if (rack->rc_gp_filled == 0) {
4241 		/* No previous reading */
4242 		rack->r_ctl.rc_rtt_diff = new_rtt_diff;
4243 	} else {
4244 		if (rack->measure_saw_probe_rtt == 0) {
4245 			/*
4246 			 * We don't want a probertt to be counted
4247 			 * since it will be negative incorrectly. We
4248 			 * expect to be reducing the RTT when we
4249 			 * pace at a slower rate.
4250 			 */
4251 			rack->r_ctl.rc_rtt_diff -= (rack->r_ctl.rc_rtt_diff / 8);
4252 			rack->r_ctl.rc_rtt_diff += (new_rtt_diff / 8);
4253 		}
4254 	}
4255 	timely_says = rack_make_timely_judgement(rack,
4256 		rack->r_ctl.rc_gp_srtt,
4257 		rack->r_ctl.rc_rtt_diff,
4258 	        rack->r_ctl.rc_prev_gp_srtt
4259 		);
4260 	bytes_ps *= HPTS_USEC_IN_SEC;
4261 	bytes_ps /= utim;
4262 	if (bytes_ps > rack->r_ctl.last_max_bw) {
4263 		/*
4264 		 * Something is on path playing
4265 		 * since this b/w is not possible based
4266 		 * on our BDP (highest rwnd and lowest rtt
4267 		 * we saw in the measurement window).
4268 		 *
4269 		 * Another option here would be to
4270 		 * instead skip the measurement.
4271 		 */
4272 		rack_log_pacing_delay_calc(rack, bytes, reqbytes,
4273 					   bytes_ps, rack->r_ctl.last_max_bw, 0,
4274 					   11, __LINE__, NULL, quality);
4275 		bytes_ps = rack->r_ctl.last_max_bw;
4276 	}
4277 	/* We store gp for b/w in bytes per second */
4278 	if (rack->rc_gp_filled == 0) {
4279 		/* Initial measurement */
4280 		if (bytes_ps) {
4281 			rack->r_ctl.gp_bw = bytes_ps;
4282 			rack->rc_gp_filled = 1;
4283 			rack->r_ctl.num_measurements = 1;
4284 			rack_set_pace_segments(rack->rc_tp, rack, __LINE__, NULL);
4285 		} else {
4286 			rack_log_pacing_delay_calc(rack, bytes_ps, reqbytes,
4287 						   rack->r_ctl.rc_app_limited_cnt,
4288 						   0, 0, 10, __LINE__, NULL, quality);
4289 		}
4290 		if (tcp_in_hpts(rack->rc_inp) &&
4291 		    (rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT)) {
4292 			/*
4293 			 * Ok we can't trust the pacer in this case
4294 			 * where we transition from un-paced to paced.
4295 			 * Or for that matter when the burst mitigation
4296 			 * was making a wild guess and got it wrong.
4297 			 * Stop the pacer and clear up all the aggregate
4298 			 * delays etc.
4299 			 */
4300 			tcp_hpts_remove(rack->rc_inp);
4301 			rack->r_ctl.rc_hpts_flags = 0;
4302 			rack->r_ctl.rc_last_output_to = 0;
4303 		}
4304 		did_add = 2;
4305 	} else if (rack->r_ctl.num_measurements < RACK_REQ_AVG) {
4306 		/* Still a small number run an average */
4307 		rack->r_ctl.gp_bw += bytes_ps;
4308 		addpart = rack->r_ctl.num_measurements;
4309 		rack->r_ctl.num_measurements++;
4310 		if (rack->r_ctl.num_measurements >= RACK_REQ_AVG) {
4311 			/* We have collected enough to move forward */
4312 			rack->r_ctl.gp_bw /= (uint64_t)rack->r_ctl.num_measurements;
4313 		}
4314 		did_add = 3;
4315 	} else {
4316 		/*
4317 		 * We want to take 1/wma of the goodput and add in to 7/8th
4318 		 * of the old value weighted by the srtt. So if your measurement
4319 		 * period is say 2 SRTT's long you would get 1/4 as the
4320 		 * value, if it was like 1/2 SRTT then you would get 1/16th.
4321 		 *
4322 		 * But we must be careful not to take too much i.e. if the
4323 		 * srtt is say 20ms and the measurement is taken over
4324 		 * 400ms our weight would be 400/20 i.e. 20. On the
4325 		 * other hand if we get a measurement over 1ms with a
4326 		 * 10ms rtt we only want to take a much smaller portion.
4327 		 */
4328 		if (rack->r_ctl.num_measurements < 0xff) {
4329 			rack->r_ctl.num_measurements++;
4330 		}
4331 		srtt = (uint64_t)tp->t_srtt;
4332 		if (srtt == 0) {
4333 			/*
4334 			 * Strange why did t_srtt go back to zero?
4335 			 */
4336 			if (rack->r_ctl.rc_rack_min_rtt)
4337 				srtt = rack->r_ctl.rc_rack_min_rtt;
4338 			else
4339 				srtt = HPTS_USEC_IN_MSEC;
4340 		}
4341 		/*
4342 		 * XXXrrs: Note for reviewers, in playing with
4343 		 * dynamic pacing I discovered this GP calculation
4344 		 * as done originally leads to some undesired results.
4345 		 * Basically you can get longer measurements contributing
4346 		 * too much to the WMA. Thus I changed it if you are doing
4347 		 * dynamic adjustments to only do the aportioned adjustment
4348 		 * if we have a very small (time wise) measurement. Longer
4349 		 * measurements just get there weight (defaulting to 1/8)
4350 		 * add to the WMA. We may want to think about changing
4351 		 * this to always do that for both sides i.e. dynamic
4352 		 * and non-dynamic... but considering lots of folks
4353 		 * were playing with this I did not want to change the
4354 		 * calculation per.se. without your thoughts.. Lawerence?
4355 		 * Peter??
4356 		 */
4357 		if (rack->rc_gp_dyn_mul == 0) {
4358 			subpart = rack->r_ctl.gp_bw * utim;
4359 			subpart /= (srtt * 8);
4360 			if (subpart < (rack->r_ctl.gp_bw / 2)) {
4361 				/*
4362 				 * The b/w update takes no more
4363 				 * away then 1/2 our running total
4364 				 * so factor it in.
4365 				 */
4366 				addpart = bytes_ps * utim;
4367 				addpart /= (srtt * 8);
4368 			} else {
4369 				/*
4370 				 * Don't allow a single measurement
4371 				 * to account for more than 1/2 of the
4372 				 * WMA. This could happen on a retransmission
4373 				 * where utim becomes huge compared to
4374 				 * srtt (multiple retransmissions when using
4375 				 * the sending rate which factors in all the
4376 				 * transmissions from the first one).
4377 				 */
4378 				subpart = rack->r_ctl.gp_bw / 2;
4379 				addpart = bytes_ps / 2;
4380 			}
4381 			resid_bw = rack->r_ctl.gp_bw - subpart;
4382 			rack->r_ctl.gp_bw = resid_bw + addpart;
4383 			did_add = 1;
4384 		} else {
4385 			if ((utim / srtt) <= 1) {
4386 				/*
4387 				 * The b/w update was over a small period
4388 				 * of time. The idea here is to prevent a small
4389 				 * measurement time period from counting
4390 				 * too much. So we scale it based on the
4391 				 * time so it attributes less than 1/rack_wma_divisor
4392 				 * of its measurement.
4393 				 */
4394 				subpart = rack->r_ctl.gp_bw * utim;
4395 				subpart /= (srtt * rack_wma_divisor);
4396 				addpart = bytes_ps * utim;
4397 				addpart /= (srtt * rack_wma_divisor);
4398 			} else {
4399 				/*
4400 				 * The scaled measurement was long
4401 				 * enough so lets just add in the
4402 				 * portion of the measurement i.e. 1/rack_wma_divisor
4403 				 */
4404 				subpart = rack->r_ctl.gp_bw / rack_wma_divisor;
4405 				addpart = bytes_ps / rack_wma_divisor;
4406 			}
4407 			if ((rack->measure_saw_probe_rtt == 0) ||
4408 		            (bytes_ps > rack->r_ctl.gp_bw)) {
4409 				/*
4410 				 * For probe-rtt we only add it in
4411 				 * if its larger, all others we just
4412 				 * add in.
4413 				 */
4414 				did_add = 1;
4415 				resid_bw = rack->r_ctl.gp_bw - subpart;
4416 				rack->r_ctl.gp_bw = resid_bw + addpart;
4417 			}
4418 		}
4419 	}
4420 	if ((rack->gp_ready == 0) &&
4421 	    (rack->r_ctl.num_measurements >= rack->r_ctl.req_measurements)) {
4422 		/* We have enough measurements now */
4423 		rack->gp_ready = 1;
4424 		rack_set_cc_pacing(rack);
4425 		if (rack->defer_options)
4426 			rack_apply_deferred_options(rack);
4427 	}
4428 	rack_log_pacing_delay_calc(rack, subpart, addpart, bytes_ps, stim,
4429 				   rack_get_bw(rack), 22, did_add, NULL, quality);
4430 	/* We do not update any multipliers if we are in or have seen a probe-rtt */
4431 	if ((rack->measure_saw_probe_rtt == 0) && rack->rc_gp_rtt_set)
4432 		rack_update_multiplier(rack, timely_says, bytes_ps,
4433 				       rack->r_ctl.rc_gp_srtt,
4434 				       rack->r_ctl.rc_rtt_diff);
4435 	rack_log_pacing_delay_calc(rack, bytes, tim, bytes_ps, stim,
4436 				   rack_get_bw(rack), 3, line, NULL, quality);
4437 	/* reset the gp srtt and setup the new prev */
4438 	rack->r_ctl.rc_prev_gp_srtt = rack->r_ctl.rc_gp_srtt;
4439 	/* Record the lost count for the next measurement */
4440 	rack->r_ctl.rc_loss_at_start = rack->r_ctl.rc_loss_count;
4441 	/*
4442 	 * We restart our diffs based on the gpsrtt in the
4443 	 * measurement window.
4444 	 */
4445 	rack->rc_gp_rtt_set = 0;
4446 	rack->rc_gp_saw_rec = 0;
4447 	rack->rc_gp_saw_ca = 0;
4448 	rack->rc_gp_saw_ss = 0;
4449 	rack->rc_dragged_bottom = 0;
4450 skip_measurement:
4451 
4452 #ifdef STATS
4453 	stats_voi_update_abs_u32(tp->t_stats, VOI_TCP_GPUT,
4454 				 gput);
4455 	/*
4456 	 * XXXLAS: This is a temporary hack, and should be
4457 	 * chained off VOI_TCP_GPUT when stats(9) grows an
4458 	 * API to deal with chained VOIs.
4459 	 */
4460 	if (tp->t_stats_gput_prev > 0)
4461 		stats_voi_update_abs_s32(tp->t_stats,
4462 					 VOI_TCP_GPUT_ND,
4463 					 ((gput - tp->t_stats_gput_prev) * 100) /
4464 					 tp->t_stats_gput_prev);
4465 #endif
4466 	tp->t_flags &= ~TF_GPUTINPROG;
4467 	tp->t_stats_gput_prev = gput;
4468 	/*
4469 	 * Now are we app limited now and there is space from where we
4470 	 * were to where we want to go?
4471 	 *
4472 	 * We don't do the other case i.e. non-applimited here since
4473 	 * the next send will trigger us picking up the missing data.
4474 	 */
4475 	if (rack->r_ctl.rc_first_appl &&
4476 	    TCPS_HAVEESTABLISHED(tp->t_state) &&
4477 	    rack->r_ctl.rc_app_limited_cnt &&
4478 	    (SEQ_GT(rack->r_ctl.rc_first_appl->r_start, th_ack)) &&
4479 	    ((rack->r_ctl.rc_first_appl->r_end - th_ack) >
4480 	     max(rc_init_window(rack), (MIN_GP_WIN * segsiz)))) {
4481 		/*
4482 		 * Yep there is enough outstanding to make a measurement here.
4483 		 */
4484 		struct rack_sendmap *rsm, fe;
4485 
4486 		rack->r_ctl.rc_gp_lowrtt = 0xffffffff;
4487 		rack->r_ctl.rc_gp_high_rwnd = rack->rc_tp->snd_wnd;
4488 		tp->gput_ts = tcp_tv_to_usectick(&rack->r_ctl.act_rcv_time);
4489 		rack->app_limited_needs_set = 0;
4490 		tp->gput_seq = th_ack;
4491 		if (rack->in_probe_rtt)
4492 			rack->measure_saw_probe_rtt = 1;
4493 		else if ((rack->measure_saw_probe_rtt) &&
4494 			 (SEQ_GEQ(tp->gput_seq, rack->r_ctl.rc_probertt_sndmax_atexit)))
4495 			rack->measure_saw_probe_rtt = 0;
4496 		if ((rack->r_ctl.rc_first_appl->r_end - th_ack) >= rack_get_measure_window(tp, rack)) {
4497 			/* There is a full window to gain info from */
4498 			tp->gput_ack = tp->gput_seq + rack_get_measure_window(tp, rack);
4499 		} else {
4500 			/* We can only measure up to the applimited point */
4501 			tp->gput_ack = tp->gput_seq + (rack->r_ctl.rc_first_appl->r_end - th_ack);
4502 			if ((tp->gput_ack - tp->gput_seq) < (MIN_GP_WIN * segsiz)) {
4503 				/*
4504 				 * We don't have enough to make a measurement.
4505 				 */
4506 				tp->t_flags &= ~TF_GPUTINPROG;
4507 				rack_log_pacing_delay_calc(rack, tp->gput_ack, tp->gput_seq,
4508 							   0, 0, 0, 6, __LINE__, NULL, quality);
4509 				return;
4510 			}
4511 		}
4512 		if (tp->t_state >= TCPS_FIN_WAIT_1) {
4513 			/*
4514 			 * We will get no more data into the SB
4515 			 * this means we need to have the data available
4516 			 * before we start a measurement.
4517 			 */
4518 			if (sbavail(&tptosocket(tp)->so_snd) < (tp->gput_ack - tp->gput_seq)) {
4519 				/* Nope not enough data. */
4520 				return;
4521 			}
4522 		}
4523 		tp->t_flags |= TF_GPUTINPROG;
4524 		/*
4525 		 * Now we need to find the timestamp of the send at tp->gput_seq
4526 		 * for the send based measurement.
4527 		 */
4528 		fe.r_start = tp->gput_seq;
4529 		rsm = RB_FIND(rack_rb_tree_head, &rack->r_ctl.rc_mtree, &fe);
4530 		if (rsm) {
4531 			/* Ok send-based limit is set */
4532 			if (SEQ_LT(rsm->r_start, tp->gput_seq)) {
4533 				/*
4534 				 * Move back to include the earlier part
4535 				 * so our ack time lines up right (this may
4536 				 * make an overlapping measurement but thats
4537 				 * ok).
4538 				 */
4539 				tp->gput_seq = rsm->r_start;
4540 			}
4541 			if (rsm->r_flags & RACK_ACKED)
4542 				tp->gput_ts = (uint32_t)rsm->r_ack_arrival;
4543 			else
4544 				rack->app_limited_needs_set = 1;
4545 			rack->r_ctl.rc_gp_output_ts = rsm->r_tim_lastsent[(rsm->r_rtr_cnt-1)];
4546 		} else {
4547 			/*
4548 			 * If we don't find the rsm due to some
4549 			 * send-limit set the current time, which
4550 			 * basically disables the send-limit.
4551 			 */
4552 			struct timeval tv;
4553 
4554 			microuptime(&tv);
4555 			rack->r_ctl.rc_gp_output_ts = rack_to_usec_ts(&tv);
4556 		}
4557 		rack_log_pacing_delay_calc(rack,
4558 					   tp->gput_seq,
4559 					   tp->gput_ack,
4560 					   (uint64_t)rsm,
4561 					   tp->gput_ts,
4562 					   rack->r_ctl.rc_app_limited_cnt,
4563 					   9,
4564 					   __LINE__, NULL, quality);
4565 	}
4566 }
4567 
4568 /*
4569  * CC wrapper hook functions
4570  */
4571 static void
4572 rack_ack_received(struct tcpcb *tp, struct tcp_rack *rack, uint32_t th_ack, uint16_t nsegs,
4573     uint16_t type, int32_t recovery)
4574 {
4575 	uint32_t prior_cwnd, acked;
4576 	struct tcp_log_buffer *lgb = NULL;
4577 	uint8_t labc_to_use, quality;
4578 
4579 	INP_WLOCK_ASSERT(tptoinpcb(tp));
4580 	tp->ccv->nsegs = nsegs;
4581 	acked = tp->ccv->bytes_this_ack = (th_ack - tp->snd_una);
4582 	if ((recovery) && (rack->r_ctl.rc_early_recovery_segs)) {
4583 		uint32_t max;
4584 
4585 		max = rack->r_ctl.rc_early_recovery_segs * ctf_fixed_maxseg(tp);
4586 		if (tp->ccv->bytes_this_ack > max) {
4587 			tp->ccv->bytes_this_ack = max;
4588 		}
4589 	}
4590 #ifdef STATS
4591 	stats_voi_update_abs_s32(tp->t_stats, VOI_TCP_CALCFRWINDIFF,
4592 	    ((int32_t)rack->r_ctl.cwnd_to_use) - tp->snd_wnd);
4593 #endif
4594 	quality = RACK_QUALITY_NONE;
4595 	if ((tp->t_flags & TF_GPUTINPROG) &&
4596 	    rack_enough_for_measurement(tp, rack, th_ack, &quality)) {
4597 		/* Measure the Goodput */
4598 		rack_do_goodput_measurement(tp, rack, th_ack, __LINE__, quality);
4599 #ifdef NETFLIX_PEAKRATE
4600 		if ((type == CC_ACK) &&
4601 		    (tp->t_maxpeakrate)) {
4602 			/*
4603 			 * We update t_peakrate_thr. This gives us roughly
4604 			 * one update per round trip time. Note
4605 			 * it will only be used if pace_always is off i.e
4606 			 * we don't do this for paced flows.
4607 			 */
4608 			rack_update_peakrate_thr(tp);
4609 		}
4610 #endif
4611 	}
4612 	/* Which way our we limited, if not cwnd limited no advance in CA */
4613 	if (tp->snd_cwnd <= tp->snd_wnd)
4614 		tp->ccv->flags |= CCF_CWND_LIMITED;
4615 	else
4616 		tp->ccv->flags &= ~CCF_CWND_LIMITED;
4617 	if (tp->snd_cwnd > tp->snd_ssthresh) {
4618 		tp->t_bytes_acked += min(tp->ccv->bytes_this_ack,
4619 			 nsegs * V_tcp_abc_l_var * ctf_fixed_maxseg(tp));
4620 		/* For the setting of a window past use the actual scwnd we are using */
4621 		if (tp->t_bytes_acked >= rack->r_ctl.cwnd_to_use) {
4622 			tp->t_bytes_acked -= rack->r_ctl.cwnd_to_use;
4623 			tp->ccv->flags |= CCF_ABC_SENTAWND;
4624 		}
4625 	} else {
4626 		tp->ccv->flags &= ~CCF_ABC_SENTAWND;
4627 		tp->t_bytes_acked = 0;
4628 	}
4629 	prior_cwnd = tp->snd_cwnd;
4630 	if ((recovery == 0) || (rack_max_abc_post_recovery == 0) || rack->r_use_labc_for_rec ||
4631 	    (rack_client_low_buf && (rack->client_bufferlvl < rack_client_low_buf)))
4632 		labc_to_use = rack->rc_labc;
4633 	else
4634 		labc_to_use = rack_max_abc_post_recovery;
4635 	if (rack_verbose_logging && (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF)) {
4636 		union tcp_log_stackspecific log;
4637 		struct timeval tv;
4638 
4639 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
4640 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
4641 		log.u_bbr.flex1 = th_ack;
4642 		log.u_bbr.flex2 = tp->ccv->flags;
4643 		log.u_bbr.flex3 = tp->ccv->bytes_this_ack;
4644 		log.u_bbr.flex4 = tp->ccv->nsegs;
4645 		log.u_bbr.flex5 = labc_to_use;
4646 		log.u_bbr.flex6 = prior_cwnd;
4647 		log.u_bbr.flex7 = V_tcp_do_newsack;
4648 		log.u_bbr.flex8 = 1;
4649 		lgb = tcp_log_event_(tp, NULL, NULL, NULL, BBR_LOG_CWND, 0,
4650 				     0, &log, false, NULL, NULL, 0, &tv);
4651 	}
4652 	if (CC_ALGO(tp)->ack_received != NULL) {
4653 		/* XXXLAS: Find a way to live without this */
4654 		tp->ccv->curack = th_ack;
4655 		tp->ccv->labc = labc_to_use;
4656 		tp->ccv->flags |= CCF_USE_LOCAL_ABC;
4657 		CC_ALGO(tp)->ack_received(tp->ccv, type);
4658 	}
4659 	if (lgb) {
4660 		lgb->tlb_stackinfo.u_bbr.flex6 = tp->snd_cwnd;
4661 	}
4662 	if (rack->r_must_retran) {
4663 		if (SEQ_GEQ(th_ack, rack->r_ctl.rc_snd_max_at_rto)) {
4664 			/*
4665 			 * We now are beyond the rxt point so lets disable
4666 			 * the flag.
4667 			 */
4668 			rack->r_ctl.rc_out_at_rto = 0;
4669 			rack->r_must_retran = 0;
4670 		} else if ((prior_cwnd + ctf_fixed_maxseg(tp)) <= tp->snd_cwnd) {
4671 			/*
4672 			 * Only decrement the rc_out_at_rto if the cwnd advances
4673 			 * at least a whole segment. Otherwise next time the peer
4674 			 * acks, we won't be able to send this generaly happens
4675 			 * when we are in Congestion Avoidance.
4676 			 */
4677 			if (acked <= rack->r_ctl.rc_out_at_rto){
4678 				rack->r_ctl.rc_out_at_rto -= acked;
4679 			} else {
4680 				rack->r_ctl.rc_out_at_rto = 0;
4681 			}
4682 		}
4683 	}
4684 #ifdef STATS
4685 	stats_voi_update_abs_ulong(tp->t_stats, VOI_TCP_LCWIN, rack->r_ctl.cwnd_to_use);
4686 #endif
4687 	if (rack->r_ctl.rc_rack_largest_cwnd < rack->r_ctl.cwnd_to_use) {
4688 		rack->r_ctl.rc_rack_largest_cwnd = rack->r_ctl.cwnd_to_use;
4689 	}
4690 #ifdef NETFLIX_PEAKRATE
4691 	/* we enforce max peak rate if it is set and we are not pacing */
4692 	if ((rack->rc_always_pace == 0) &&
4693 	    tp->t_peakrate_thr &&
4694 	    (tp->snd_cwnd > tp->t_peakrate_thr)) {
4695 		tp->snd_cwnd = tp->t_peakrate_thr;
4696 	}
4697 #endif
4698 }
4699 
4700 static void
4701 tcp_rack_partialack(struct tcpcb *tp)
4702 {
4703 	struct tcp_rack *rack;
4704 
4705 	rack = (struct tcp_rack *)tp->t_fb_ptr;
4706 	INP_WLOCK_ASSERT(tptoinpcb(tp));
4707 	/*
4708 	 * If we are doing PRR and have enough
4709 	 * room to send <or> we are pacing and prr
4710 	 * is disabled we will want to see if we
4711 	 * can send data (by setting r_wanted_output to
4712 	 * true).
4713 	 */
4714 	if ((rack->r_ctl.rc_prr_sndcnt > 0) ||
4715 	    rack->rack_no_prr)
4716 		rack->r_wanted_output = 1;
4717 }
4718 
4719 static void
4720 rack_post_recovery(struct tcpcb *tp, uint32_t th_ack)
4721 {
4722 	struct tcp_rack *rack;
4723 	uint32_t orig_cwnd;
4724 
4725 	orig_cwnd = tp->snd_cwnd;
4726 	INP_WLOCK_ASSERT(tptoinpcb(tp));
4727 	rack = (struct tcp_rack *)tp->t_fb_ptr;
4728 	/* only alert CC if we alerted when we entered */
4729 	if (CC_ALGO(tp)->post_recovery != NULL) {
4730 		tp->ccv->curack = th_ack;
4731 		CC_ALGO(tp)->post_recovery(tp->ccv);
4732 		if (tp->snd_cwnd < tp->snd_ssthresh) {
4733 			/*
4734 			 * Rack has burst control and pacing
4735 			 * so lets not set this any lower than
4736 			 * snd_ssthresh per RFC-6582 (option 2).
4737 			 */
4738 			tp->snd_cwnd = tp->snd_ssthresh;
4739 		}
4740 	}
4741 	if (rack_verbose_logging && (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF)) {
4742 		union tcp_log_stackspecific log;
4743 		struct timeval tv;
4744 
4745 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
4746 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
4747 		log.u_bbr.flex1 = th_ack;
4748 		log.u_bbr.flex2 = tp->ccv->flags;
4749 		log.u_bbr.flex3 = tp->ccv->bytes_this_ack;
4750 		log.u_bbr.flex4 = tp->ccv->nsegs;
4751 		log.u_bbr.flex5 = V_tcp_abc_l_var;
4752 		log.u_bbr.flex6 = orig_cwnd;
4753 		log.u_bbr.flex7 = V_tcp_do_newsack;
4754 		log.u_bbr.pkts_out = rack->r_ctl.rc_prr_sndcnt;
4755 		log.u_bbr.flex8 = 2;
4756 		tcp_log_event_(tp, NULL, NULL, NULL, BBR_LOG_CWND, 0,
4757 			       0, &log, false, NULL, NULL, 0, &tv);
4758 	}
4759 	if ((rack->rack_no_prr == 0) &&
4760 	    (rack->no_prr_addback == 0) &&
4761 	    (rack->r_ctl.rc_prr_sndcnt > 0)) {
4762 		/*
4763 		 * Suck the next prr cnt back into cwnd, but
4764 		 * only do that if we are not application limited.
4765 		 */
4766 		if (ctf_outstanding(tp) <= sbavail(&tptosocket(tp)->so_snd)) {
4767 			/*
4768 			 * We are allowed to add back to the cwnd the amount we did
4769 			 * not get out if:
4770 			 * a) no_prr_addback is off.
4771 			 * b) we are not app limited
4772 			 * c) we are doing prr
4773 			 * <and>
4774 			 * d) it is bounded by rack_prr_addbackmax (if addback is 0, then none).
4775 			 */
4776 			tp->snd_cwnd += min((ctf_fixed_maxseg(tp) * rack_prr_addbackmax),
4777 					    rack->r_ctl.rc_prr_sndcnt);
4778 		}
4779 		rack->r_ctl.rc_prr_sndcnt = 0;
4780 		rack_log_to_prr(rack, 1, 0, __LINE__);
4781 	}
4782 	rack_log_to_prr(rack, 14, orig_cwnd, __LINE__);
4783 	tp->snd_recover = tp->snd_una;
4784 	if (rack->r_ctl.dsack_persist) {
4785 		rack->r_ctl.dsack_persist--;
4786 		if (rack->r_ctl.num_dsack && (rack->r_ctl.dsack_persist == 0)) {
4787 			rack->r_ctl.num_dsack = 0;
4788 		}
4789 		rack_log_dsack_event(rack, 1, __LINE__, 0, 0);
4790 	}
4791 	EXIT_RECOVERY(tp->t_flags);
4792 }
4793 
4794 static void
4795 rack_cong_signal(struct tcpcb *tp, uint32_t type, uint32_t ack, int line)
4796 {
4797 	struct tcp_rack *rack;
4798 	uint32_t ssthresh_enter, cwnd_enter, in_rec_at_entry, orig_cwnd;
4799 
4800 	INP_WLOCK_ASSERT(tptoinpcb(tp));
4801 #ifdef STATS
4802 	stats_voi_update_abs_u32(tp->t_stats, VOI_TCP_CSIG, type);
4803 #endif
4804 	if (IN_RECOVERY(tp->t_flags) == 0) {
4805 		in_rec_at_entry = 0;
4806 		ssthresh_enter = tp->snd_ssthresh;
4807 		cwnd_enter = tp->snd_cwnd;
4808 	} else
4809 		in_rec_at_entry = 1;
4810 	rack = (struct tcp_rack *)tp->t_fb_ptr;
4811 	switch (type) {
4812 	case CC_NDUPACK:
4813 		tp->t_flags &= ~TF_WASFRECOVERY;
4814 		tp->t_flags &= ~TF_WASCRECOVERY;
4815 		if (!IN_FASTRECOVERY(tp->t_flags)) {
4816 			rack->r_ctl.rc_prr_delivered = 0;
4817 			rack->r_ctl.rc_prr_out = 0;
4818 			if (rack->rack_no_prr == 0) {
4819 				rack->r_ctl.rc_prr_sndcnt = ctf_fixed_maxseg(tp);
4820 				rack_log_to_prr(rack, 2, in_rec_at_entry, line);
4821 			}
4822 			rack->r_ctl.rc_prr_recovery_fs = tp->snd_max - tp->snd_una;
4823 			tp->snd_recover = tp->snd_max;
4824 			if (tp->t_flags2 & TF2_ECN_PERMIT)
4825 				tp->t_flags2 |= TF2_ECN_SND_CWR;
4826 		}
4827 		break;
4828 	case CC_ECN:
4829 		if (!IN_CONGRECOVERY(tp->t_flags) ||
4830 		    /*
4831 		     * Allow ECN reaction on ACK to CWR, if
4832 		     * that data segment was also CE marked.
4833 		     */
4834 		    SEQ_GEQ(ack, tp->snd_recover)) {
4835 			EXIT_CONGRECOVERY(tp->t_flags);
4836 			KMOD_TCPSTAT_INC(tcps_ecn_rcwnd);
4837 			tp->snd_recover = tp->snd_max + 1;
4838 			if (tp->t_flags2 & TF2_ECN_PERMIT)
4839 				tp->t_flags2 |= TF2_ECN_SND_CWR;
4840 		}
4841 		break;
4842 	case CC_RTO:
4843 		tp->t_dupacks = 0;
4844 		tp->t_bytes_acked = 0;
4845 		EXIT_RECOVERY(tp->t_flags);
4846 		tp->snd_ssthresh = max(2, min(tp->snd_wnd, rack->r_ctl.cwnd_to_use) / 2 /
4847 		    ctf_fixed_maxseg(tp)) * ctf_fixed_maxseg(tp);
4848 		orig_cwnd = tp->snd_cwnd;
4849 		tp->snd_cwnd = ctf_fixed_maxseg(tp);
4850 		rack_log_to_prr(rack, 16, orig_cwnd, line);
4851 		if (tp->t_flags2 & TF2_ECN_PERMIT)
4852 			tp->t_flags2 |= TF2_ECN_SND_CWR;
4853 		break;
4854 	case CC_RTO_ERR:
4855 		KMOD_TCPSTAT_INC(tcps_sndrexmitbad);
4856 		/* RTO was unnecessary, so reset everything. */
4857 		tp->snd_cwnd = tp->snd_cwnd_prev;
4858 		tp->snd_ssthresh = tp->snd_ssthresh_prev;
4859 		tp->snd_recover = tp->snd_recover_prev;
4860 		if (tp->t_flags & TF_WASFRECOVERY) {
4861 			ENTER_FASTRECOVERY(tp->t_flags);
4862 			tp->t_flags &= ~TF_WASFRECOVERY;
4863 		}
4864 		if (tp->t_flags & TF_WASCRECOVERY) {
4865 			ENTER_CONGRECOVERY(tp->t_flags);
4866 			tp->t_flags &= ~TF_WASCRECOVERY;
4867 		}
4868 		tp->snd_nxt = tp->snd_max;
4869 		tp->t_badrxtwin = 0;
4870 		break;
4871 	}
4872 	if ((CC_ALGO(tp)->cong_signal != NULL)  &&
4873 	    (type != CC_RTO)){
4874 		tp->ccv->curack = ack;
4875 		CC_ALGO(tp)->cong_signal(tp->ccv, type);
4876 	}
4877 	if ((in_rec_at_entry == 0) && IN_RECOVERY(tp->t_flags)) {
4878 		rack_log_to_prr(rack, 15, cwnd_enter, line);
4879 		rack->r_ctl.dsack_byte_cnt = 0;
4880 		rack->r_ctl.retran_during_recovery = 0;
4881 		rack->r_ctl.rc_cwnd_at_erec = cwnd_enter;
4882 		rack->r_ctl.rc_ssthresh_at_erec = ssthresh_enter;
4883 		rack->r_ent_rec_ns = 1;
4884 	}
4885 }
4886 
4887 static inline void
4888 rack_cc_after_idle(struct tcp_rack *rack, struct tcpcb *tp)
4889 {
4890 	uint32_t i_cwnd;
4891 
4892 	INP_WLOCK_ASSERT(tptoinpcb(tp));
4893 
4894 #ifdef NETFLIX_STATS
4895 	KMOD_TCPSTAT_INC(tcps_idle_restarts);
4896 	if (tp->t_state == TCPS_ESTABLISHED)
4897 		KMOD_TCPSTAT_INC(tcps_idle_estrestarts);
4898 #endif
4899 	if (CC_ALGO(tp)->after_idle != NULL)
4900 		CC_ALGO(tp)->after_idle(tp->ccv);
4901 
4902 	if (tp->snd_cwnd == 1)
4903 		i_cwnd = tp->t_maxseg;		/* SYN(-ACK) lost */
4904 	else
4905 		i_cwnd = rc_init_window(rack);
4906 
4907 	/*
4908 	 * Being idle is no different than the initial window. If the cc
4909 	 * clamps it down below the initial window raise it to the initial
4910 	 * window.
4911 	 */
4912 	if (tp->snd_cwnd < i_cwnd) {
4913 		tp->snd_cwnd = i_cwnd;
4914 	}
4915 }
4916 
4917 /*
4918  * Indicate whether this ack should be delayed.  We can delay the ack if
4919  * following conditions are met:
4920  *	- There is no delayed ack timer in progress.
4921  *	- Our last ack wasn't a 0-sized window. We never want to delay
4922  *	  the ack that opens up a 0-sized window.
4923  *	- LRO wasn't used for this segment. We make sure by checking that the
4924  *	  segment size is not larger than the MSS.
4925  *	- Delayed acks are enabled or this is a half-synchronized T/TCP
4926  *	  connection.
4927  */
4928 #define DELAY_ACK(tp, tlen)			 \
4929 	(((tp->t_flags & TF_RXWIN0SENT) == 0) && \
4930 	((tp->t_flags & TF_DELACK) == 0) &&	 \
4931 	(tlen <= tp->t_maxseg) &&		 \
4932 	(tp->t_delayed_ack || (tp->t_flags & TF_NEEDSYN)))
4933 
4934 static struct rack_sendmap *
4935 rack_find_lowest_rsm(struct tcp_rack *rack)
4936 {
4937 	struct rack_sendmap *rsm;
4938 
4939 	/*
4940 	 * Walk the time-order transmitted list looking for an rsm that is
4941 	 * not acked. This will be the one that was sent the longest time
4942 	 * ago that is still outstanding.
4943 	 */
4944 	TAILQ_FOREACH(rsm, &rack->r_ctl.rc_tmap, r_tnext) {
4945 		if (rsm->r_flags & RACK_ACKED) {
4946 			continue;
4947 		}
4948 		goto finish;
4949 	}
4950 finish:
4951 	return (rsm);
4952 }
4953 
4954 static struct rack_sendmap *
4955 rack_find_high_nonack(struct tcp_rack *rack, struct rack_sendmap *rsm)
4956 {
4957 	struct rack_sendmap *prsm;
4958 
4959 	/*
4960 	 * Walk the sequence order list backward until we hit and arrive at
4961 	 * the highest seq not acked. In theory when this is called it
4962 	 * should be the last segment (which it was not).
4963 	 */
4964 	prsm = rsm;
4965 	RB_FOREACH_REVERSE_FROM(prsm, rack_rb_tree_head, rsm) {
4966 		if (prsm->r_flags & (RACK_ACKED | RACK_HAS_FIN)) {
4967 			continue;
4968 		}
4969 		return (prsm);
4970 	}
4971 	return (NULL);
4972 }
4973 
4974 static uint32_t
4975 rack_calc_thresh_rack(struct tcp_rack *rack, uint32_t srtt, uint32_t cts)
4976 {
4977 	int32_t lro;
4978 	uint32_t thresh;
4979 
4980 	/*
4981 	 * lro is the flag we use to determine if we have seen reordering.
4982 	 * If it gets set we have seen reordering. The reorder logic either
4983 	 * works in one of two ways:
4984 	 *
4985 	 * If reorder-fade is configured, then we track the last time we saw
4986 	 * re-ordering occur. If we reach the point where enough time as
4987 	 * passed we no longer consider reordering has occuring.
4988 	 *
4989 	 * Or if reorder-face is 0, then once we see reordering we consider
4990 	 * the connection to alway be subject to reordering and just set lro
4991 	 * to 1.
4992 	 *
4993 	 * In the end if lro is non-zero we add the extra time for
4994 	 * reordering in.
4995 	 */
4996 	if (srtt == 0)
4997 		srtt = 1;
4998 	if (rack->r_ctl.rc_reorder_ts) {
4999 		if (rack->r_ctl.rc_reorder_fade) {
5000 			if (SEQ_GEQ(cts, rack->r_ctl.rc_reorder_ts)) {
5001 				lro = cts - rack->r_ctl.rc_reorder_ts;
5002 				if (lro == 0) {
5003 					/*
5004 					 * No time as passed since the last
5005 					 * reorder, mark it as reordering.
5006 					 */
5007 					lro = 1;
5008 				}
5009 			} else {
5010 				/* Negative time? */
5011 				lro = 0;
5012 			}
5013 			if (lro > rack->r_ctl.rc_reorder_fade) {
5014 				/* Turn off reordering seen too */
5015 				rack->r_ctl.rc_reorder_ts = 0;
5016 				lro = 0;
5017 			}
5018 		} else {
5019 			/* Reodering does not fade */
5020 			lro = 1;
5021 		}
5022 	} else {
5023 		lro = 0;
5024 	}
5025 	if (rack->rc_rack_tmr_std_based == 0) {
5026 		thresh = srtt + rack->r_ctl.rc_pkt_delay;
5027 	} else {
5028 		/* Standards based pkt-delay is 1/4 srtt */
5029 		thresh = srtt +  (srtt >> 2);
5030 	}
5031 	if (lro && (rack->rc_rack_tmr_std_based == 0)) {
5032 		/* It must be set, if not you get 1/4 rtt */
5033 		if (rack->r_ctl.rc_reorder_shift)
5034 			thresh += (srtt >> rack->r_ctl.rc_reorder_shift);
5035 		else
5036 			thresh += (srtt >> 2);
5037 	}
5038 	if (rack->rc_rack_use_dsack &&
5039 	    lro &&
5040 	    (rack->r_ctl.num_dsack > 0)) {
5041 		/*
5042 		 * We only increase the reordering window if we
5043 		 * have seen reordering <and> we have a DSACK count.
5044 		 */
5045 		thresh += rack->r_ctl.num_dsack * (srtt >> 2);
5046 		rack_log_dsack_event(rack, 4, __LINE__, srtt, thresh);
5047 	}
5048 	/* SRTT * 2 is the ceiling */
5049 	if (thresh > (srtt * 2)) {
5050 		thresh = srtt * 2;
5051 	}
5052 	/* And we don't want it above the RTO max either */
5053 	if (thresh > rack_rto_max) {
5054 		thresh = rack_rto_max;
5055 	}
5056 	rack_log_dsack_event(rack, 6, __LINE__, srtt, thresh);
5057 	return (thresh);
5058 }
5059 
5060 static uint32_t
5061 rack_calc_thresh_tlp(struct tcpcb *tp, struct tcp_rack *rack,
5062 		     struct rack_sendmap *rsm, uint32_t srtt)
5063 {
5064 	struct rack_sendmap *prsm;
5065 	uint32_t thresh, len;
5066 	int segsiz;
5067 
5068 	if (srtt == 0)
5069 		srtt = 1;
5070 	if (rack->r_ctl.rc_tlp_threshold)
5071 		thresh = srtt + (srtt / rack->r_ctl.rc_tlp_threshold);
5072 	else
5073 		thresh = (srtt * 2);
5074 
5075 	/* Get the previous sent packet, if any */
5076 	segsiz = min(ctf_fixed_maxseg(tp), rack->r_ctl.rc_pace_min_segs);
5077 	len = rsm->r_end - rsm->r_start;
5078 	if (rack->rack_tlp_threshold_use == TLP_USE_ID) {
5079 		/* Exactly like the ID */
5080 		if (((tp->snd_max - tp->snd_una) - rack->r_ctl.rc_sacked + rack->r_ctl.rc_holes_rxt) <= segsiz) {
5081 			uint32_t alt_thresh;
5082 			/*
5083 			 * Compensate for delayed-ack with the d-ack time.
5084 			 */
5085 			alt_thresh = srtt + (srtt / 2) + rack_delayed_ack_time;
5086 			if (alt_thresh > thresh)
5087 				thresh = alt_thresh;
5088 		}
5089 	} else if (rack->rack_tlp_threshold_use == TLP_USE_TWO_ONE) {
5090 		/* 2.1 behavior */
5091 		prsm = TAILQ_PREV(rsm, rack_head, r_tnext);
5092 		if (prsm && (len <= segsiz)) {
5093 			/*
5094 			 * Two packets outstanding, thresh should be (2*srtt) +
5095 			 * possible inter-packet delay (if any).
5096 			 */
5097 			uint32_t inter_gap = 0;
5098 			int idx, nidx;
5099 
5100 			idx = rsm->r_rtr_cnt - 1;
5101 			nidx = prsm->r_rtr_cnt - 1;
5102 			if (rsm->r_tim_lastsent[nidx] >= prsm->r_tim_lastsent[idx]) {
5103 				/* Yes it was sent later (or at the same time) */
5104 				inter_gap = rsm->r_tim_lastsent[idx] - prsm->r_tim_lastsent[nidx];
5105 			}
5106 			thresh += inter_gap;
5107 		} else if (len <= segsiz) {
5108 			/*
5109 			 * Possibly compensate for delayed-ack.
5110 			 */
5111 			uint32_t alt_thresh;
5112 
5113 			alt_thresh = srtt + (srtt / 2) + rack_delayed_ack_time;
5114 			if (alt_thresh > thresh)
5115 				thresh = alt_thresh;
5116 		}
5117 	} else if (rack->rack_tlp_threshold_use == TLP_USE_TWO_TWO) {
5118 		/* 2.2 behavior */
5119 		if (len <= segsiz) {
5120 			uint32_t alt_thresh;
5121 			/*
5122 			 * Compensate for delayed-ack with the d-ack time.
5123 			 */
5124 			alt_thresh = srtt + (srtt / 2) + rack_delayed_ack_time;
5125 			if (alt_thresh > thresh)
5126 				thresh = alt_thresh;
5127 		}
5128 	}
5129 	/* Not above an RTO */
5130 	if (thresh > tp->t_rxtcur) {
5131 		thresh = tp->t_rxtcur;
5132 	}
5133 	/* Not above a RTO max */
5134 	if (thresh > rack_rto_max) {
5135 		thresh = rack_rto_max;
5136 	}
5137 	/* Apply user supplied min TLP */
5138 	if (thresh < rack_tlp_min) {
5139 		thresh = rack_tlp_min;
5140 	}
5141 	return (thresh);
5142 }
5143 
5144 static uint32_t
5145 rack_grab_rtt(struct tcpcb *tp, struct tcp_rack *rack)
5146 {
5147 	/*
5148 	 * We want the rack_rtt which is the
5149 	 * last rtt we measured. However if that
5150 	 * does not exist we fallback to the srtt (which
5151 	 * we probably will never do) and then as a last
5152 	 * resort we use RACK_INITIAL_RTO if no srtt is
5153 	 * yet set.
5154 	 */
5155 	if (rack->rc_rack_rtt)
5156 		return (rack->rc_rack_rtt);
5157 	else if (tp->t_srtt == 0)
5158 		return (RACK_INITIAL_RTO);
5159 	return (tp->t_srtt);
5160 }
5161 
5162 static struct rack_sendmap *
5163 rack_check_recovery_mode(struct tcpcb *tp, uint32_t tsused)
5164 {
5165 	/*
5166 	 * Check to see that we don't need to fall into recovery. We will
5167 	 * need to do so if our oldest transmit is past the time we should
5168 	 * have had an ack.
5169 	 */
5170 	struct tcp_rack *rack;
5171 	struct rack_sendmap *rsm;
5172 	int32_t idx;
5173 	uint32_t srtt, thresh;
5174 
5175 	rack = (struct tcp_rack *)tp->t_fb_ptr;
5176 	if (RB_EMPTY(&rack->r_ctl.rc_mtree)) {
5177 		return (NULL);
5178 	}
5179 	rsm = TAILQ_FIRST(&rack->r_ctl.rc_tmap);
5180 	if (rsm == NULL)
5181 		return (NULL);
5182 
5183 
5184 	if (rsm->r_flags & RACK_ACKED) {
5185 		rsm = rack_find_lowest_rsm(rack);
5186 		if (rsm == NULL)
5187 			return (NULL);
5188 	}
5189 	idx = rsm->r_rtr_cnt - 1;
5190 	srtt = rack_grab_rtt(tp, rack);
5191 	thresh = rack_calc_thresh_rack(rack, srtt, tsused);
5192 	if (TSTMP_LT(tsused, ((uint32_t)rsm->r_tim_lastsent[idx]))) {
5193 		return (NULL);
5194 	}
5195 	if ((tsused - ((uint32_t)rsm->r_tim_lastsent[idx])) < thresh) {
5196 		return (NULL);
5197 	}
5198 	/* Ok if we reach here we are over-due and this guy can be sent */
5199 	rack_cong_signal(tp, CC_NDUPACK, tp->snd_una, __LINE__);
5200 	return (rsm);
5201 }
5202 
5203 static uint32_t
5204 rack_get_persists_timer_val(struct tcpcb *tp, struct tcp_rack *rack)
5205 {
5206 	int32_t t;
5207 	int32_t tt;
5208 	uint32_t ret_val;
5209 
5210 	t = (tp->t_srtt + (tp->t_rttvar << 2));
5211 	RACK_TCPT_RANGESET(tt, t * tcp_backoff[tp->t_rxtshift],
5212  	    rack_persist_min, rack_persist_max, rack->r_ctl.timer_slop);
5213 	rack->r_ctl.rc_hpts_flags |= PACE_TMR_PERSIT;
5214 	ret_val = (uint32_t)tt;
5215 	return (ret_val);
5216 }
5217 
5218 static uint32_t
5219 rack_timer_start(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cts, int sup_rack)
5220 {
5221 	/*
5222 	 * Start the FR timer, we do this based on getting the first one in
5223 	 * the rc_tmap. Note that if its NULL we must stop the timer. in all
5224 	 * events we need to stop the running timer (if its running) before
5225 	 * starting the new one.
5226 	 */
5227 	uint32_t thresh, exp, to, srtt, time_since_sent, tstmp_touse;
5228 	uint32_t srtt_cur;
5229 	int32_t idx;
5230 	int32_t is_tlp_timer = 0;
5231 	struct rack_sendmap *rsm;
5232 
5233 	if (rack->t_timers_stopped) {
5234 		/* All timers have been stopped none are to run */
5235 		return (0);
5236 	}
5237 	if (rack->rc_in_persist) {
5238 		/* We can't start any timer in persists */
5239 		return (rack_get_persists_timer_val(tp, rack));
5240 	}
5241 	rack->rc_on_min_to = 0;
5242 	if ((tp->t_state < TCPS_ESTABLISHED) ||
5243 	    ((tp->t_flags & TF_SACK_PERMIT) == 0)) {
5244 		goto activate_rxt;
5245 	}
5246 	rsm = TAILQ_FIRST(&rack->r_ctl.rc_tmap);
5247 	if ((rsm == NULL) || sup_rack) {
5248 		/* Nothing on the send map or no rack */
5249 activate_rxt:
5250 		time_since_sent = 0;
5251 		rsm = TAILQ_FIRST(&rack->r_ctl.rc_tmap);
5252 		if (rsm) {
5253 			/*
5254 			 * Should we discount the RTX timer any?
5255 			 *
5256 			 * We want to discount it the smallest amount.
5257 			 * If a timer (Rack/TLP or RXT) has gone off more
5258 			 * recently thats the discount we want to use (now - timer time).
5259 			 * If the retransmit of the oldest packet was more recent then
5260 			 * we want to use that (now - oldest-packet-last_transmit_time).
5261 			 *
5262 			 */
5263 			idx = rsm->r_rtr_cnt - 1;
5264 			if (TSTMP_GEQ(rack->r_ctl.rc_tlp_rxt_last_time, ((uint32_t)rsm->r_tim_lastsent[idx])))
5265 				tstmp_touse = (uint32_t)rack->r_ctl.rc_tlp_rxt_last_time;
5266 			else
5267 				tstmp_touse = (uint32_t)rsm->r_tim_lastsent[idx];
5268 			if (TSTMP_GT(cts, tstmp_touse))
5269 			    time_since_sent = cts - tstmp_touse;
5270 		}
5271 		if (SEQ_LT(tp->snd_una, tp->snd_max) ||
5272 		    sbavail(&tptosocket(tp)->so_snd)) {
5273 			rack->r_ctl.rc_hpts_flags |= PACE_TMR_RXT;
5274 			to = tp->t_rxtcur;
5275 			if (to > time_since_sent)
5276 				to -= time_since_sent;
5277 			else
5278 				to = rack->r_ctl.rc_min_to;
5279 			if (to == 0)
5280 				to = 1;
5281 			/* Special case for KEEPINIT */
5282 			if ((TCPS_HAVEESTABLISHED(tp->t_state) == 0) &&
5283 			    (TP_KEEPINIT(tp) != 0) &&
5284 			    rsm) {
5285 				/*
5286 				 * We have to put a ceiling on the rxt timer
5287 				 * of the keep-init timeout.
5288 				 */
5289 				uint32_t max_time, red;
5290 
5291 				max_time = TICKS_2_USEC(TP_KEEPINIT(tp));
5292 				if (TSTMP_GT(cts, (uint32_t)rsm->r_tim_lastsent[0])) {
5293 					red = (cts - (uint32_t)rsm->r_tim_lastsent[0]);
5294 					if (red < max_time)
5295 						max_time -= red;
5296 					else
5297 						max_time = 1;
5298 				}
5299 				/* Reduce timeout to the keep value if needed */
5300 				if (max_time < to)
5301 					to = max_time;
5302 			}
5303 			return (to);
5304 		}
5305 		return (0);
5306 	}
5307 	if (rsm->r_flags & RACK_ACKED) {
5308 		rsm = rack_find_lowest_rsm(rack);
5309 		if (rsm == NULL) {
5310 			/* No lowest? */
5311 			goto activate_rxt;
5312 		}
5313 	}
5314 	if (rack->sack_attack_disable) {
5315 		/*
5316 		 * We don't want to do
5317 		 * any TLP's if you are an attacker.
5318 		 * Though if you are doing what
5319 		 * is expected you may still have
5320 		 * SACK-PASSED marks.
5321 		 */
5322 		goto activate_rxt;
5323 	}
5324 	/* Convert from ms to usecs */
5325 	if ((rsm->r_flags & RACK_SACK_PASSED) ||
5326 	    (rsm->r_flags & RACK_RWND_COLLAPSED) ||
5327 	    (rsm->r_dupack >= DUP_ACK_THRESHOLD)) {
5328 		if ((tp->t_flags & TF_SENTFIN) &&
5329 		    ((tp->snd_max - tp->snd_una) == 1) &&
5330 		    (rsm->r_flags & RACK_HAS_FIN)) {
5331 			/*
5332 			 * We don't start a rack timer if all we have is a
5333 			 * FIN outstanding.
5334 			 */
5335 			goto activate_rxt;
5336 		}
5337 		if ((rack->use_rack_rr == 0) &&
5338 		    (IN_FASTRECOVERY(tp->t_flags)) &&
5339 		    (rack->rack_no_prr == 0) &&
5340 		     (rack->r_ctl.rc_prr_sndcnt  < ctf_fixed_maxseg(tp))) {
5341 			/*
5342 			 * We are not cheating, in recovery  and
5343 			 * not enough ack's to yet get our next
5344 			 * retransmission out.
5345 			 *
5346 			 * Note that classified attackers do not
5347 			 * get to use the rack-cheat.
5348 			 */
5349 			goto activate_tlp;
5350 		}
5351 		srtt = rack_grab_rtt(tp, rack);
5352 		thresh = rack_calc_thresh_rack(rack, srtt, cts);
5353 		idx = rsm->r_rtr_cnt - 1;
5354 		exp = ((uint32_t)rsm->r_tim_lastsent[idx]) + thresh;
5355 		if (SEQ_GEQ(exp, cts)) {
5356 			to = exp - cts;
5357 			if (to < rack->r_ctl.rc_min_to) {
5358 				to = rack->r_ctl.rc_min_to;
5359 				if (rack->r_rr_config == 3)
5360 					rack->rc_on_min_to = 1;
5361 			}
5362 		} else {
5363 			to = rack->r_ctl.rc_min_to;
5364 			if (rack->r_rr_config == 3)
5365 				rack->rc_on_min_to = 1;
5366 		}
5367 	} else {
5368 		/* Ok we need to do a TLP not RACK */
5369 activate_tlp:
5370 		if ((rack->rc_tlp_in_progress != 0) &&
5371 		    (rack->r_ctl.rc_tlp_cnt_out >= rack_tlp_limit)) {
5372 			/*
5373 			 * The previous send was a TLP and we have sent
5374 			 * N TLP's without sending new data.
5375 			 */
5376 			goto activate_rxt;
5377 		}
5378 		rsm = TAILQ_LAST_FAST(&rack->r_ctl.rc_tmap, rack_sendmap, r_tnext);
5379 		if (rsm == NULL) {
5380 			/* We found no rsm to TLP with. */
5381 			goto activate_rxt;
5382 		}
5383 		if (rsm->r_flags & RACK_HAS_FIN) {
5384 			/* If its a FIN we dont do TLP */
5385 			rsm = NULL;
5386 			goto activate_rxt;
5387 		}
5388 		idx = rsm->r_rtr_cnt - 1;
5389 		time_since_sent = 0;
5390 		if (TSTMP_GEQ(((uint32_t)rsm->r_tim_lastsent[idx]), rack->r_ctl.rc_tlp_rxt_last_time))
5391 			tstmp_touse = (uint32_t)rsm->r_tim_lastsent[idx];
5392 		else
5393 			tstmp_touse = (uint32_t)rack->r_ctl.rc_tlp_rxt_last_time;
5394 		if (TSTMP_GT(cts, tstmp_touse))
5395 		    time_since_sent = cts - tstmp_touse;
5396 		is_tlp_timer = 1;
5397 		if (tp->t_srtt) {
5398 			if ((rack->rc_srtt_measure_made == 0) &&
5399 			    (tp->t_srtt == 1)) {
5400 				/*
5401 				 * If another stack as run and set srtt to 1,
5402 				 * then the srtt was 0, so lets use the initial.
5403 				 */
5404 				srtt = RACK_INITIAL_RTO;
5405 			} else {
5406 				srtt_cur = tp->t_srtt;
5407 				srtt = srtt_cur;
5408 			}
5409 		} else
5410 			srtt = RACK_INITIAL_RTO;
5411 		/*
5412 		 * If the SRTT is not keeping up and the
5413 		 * rack RTT has spiked we want to use
5414 		 * the last RTT not the smoothed one.
5415 		 */
5416 		if (rack_tlp_use_greater &&
5417 		    tp->t_srtt &&
5418 		    (srtt < rack_grab_rtt(tp, rack))) {
5419 			srtt = rack_grab_rtt(tp, rack);
5420 		}
5421 		thresh = rack_calc_thresh_tlp(tp, rack, rsm, srtt);
5422 		if (thresh > time_since_sent) {
5423 			to = thresh - time_since_sent;
5424 		} else {
5425 			to = rack->r_ctl.rc_min_to;
5426 			rack_log_alt_to_to_cancel(rack,
5427 						  thresh,		/* flex1 */
5428 						  time_since_sent,	/* flex2 */
5429 						  tstmp_touse,		/* flex3 */
5430 						  rack->r_ctl.rc_tlp_rxt_last_time, /* flex4 */
5431 						  (uint32_t)rsm->r_tim_lastsent[idx],
5432 						  srtt,
5433 						  idx, 99);
5434 		}
5435 		if (to < rack_tlp_min) {
5436 			to = rack_tlp_min;
5437 		}
5438 		if (to > TICKS_2_USEC(TCPTV_REXMTMAX)) {
5439 			/*
5440 			 * If the TLP time works out to larger than the max
5441 			 * RTO lets not do TLP.. just RTO.
5442 			 */
5443 			goto activate_rxt;
5444 		}
5445 	}
5446 	if (is_tlp_timer == 0) {
5447 		rack->r_ctl.rc_hpts_flags |= PACE_TMR_RACK;
5448 	} else {
5449 		rack->r_ctl.rc_hpts_flags |= PACE_TMR_TLP;
5450 	}
5451 	if (to == 0)
5452 		to = 1;
5453 	return (to);
5454 }
5455 
5456 static void
5457 rack_enter_persist(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cts)
5458 {
5459 	if (rack->rc_in_persist == 0) {
5460 		if (tp->t_flags & TF_GPUTINPROG) {
5461 			/*
5462 			 * Stop the goodput now, the calling of the
5463 			 * measurement function clears the flag.
5464 			 */
5465 			rack_do_goodput_measurement(tp, rack, tp->snd_una, __LINE__,
5466 						    RACK_QUALITY_PERSIST);
5467 		}
5468 #ifdef NETFLIX_SHARED_CWND
5469 		if (rack->r_ctl.rc_scw) {
5470 			tcp_shared_cwnd_idle(rack->r_ctl.rc_scw, rack->r_ctl.rc_scw_index);
5471 			rack->rack_scwnd_is_idle = 1;
5472 		}
5473 #endif
5474 		rack->r_ctl.rc_went_idle_time = tcp_get_usecs(NULL);
5475 		if (rack->r_ctl.rc_went_idle_time == 0)
5476 			rack->r_ctl.rc_went_idle_time = 1;
5477 		rack_timer_cancel(tp, rack, cts, __LINE__);
5478 		rack->r_ctl.persist_lost_ends = 0;
5479 		rack->probe_not_answered = 0;
5480 		rack->forced_ack = 0;
5481 		tp->t_rxtshift = 0;
5482 		RACK_TCPT_RANGESET(tp->t_rxtcur, RACK_REXMTVAL(tp),
5483 			      rack_rto_min, rack_rto_max, rack->r_ctl.timer_slop);
5484 		rack->rc_in_persist = 1;
5485 	}
5486 }
5487 
5488 static void
5489 rack_exit_persist(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cts)
5490 {
5491 	if (tcp_in_hpts(rack->rc_inp)) {
5492 		tcp_hpts_remove(rack->rc_inp);
5493 		rack->r_ctl.rc_hpts_flags = 0;
5494 	}
5495 #ifdef NETFLIX_SHARED_CWND
5496 	if (rack->r_ctl.rc_scw) {
5497 		tcp_shared_cwnd_active(rack->r_ctl.rc_scw, rack->r_ctl.rc_scw_index);
5498 		rack->rack_scwnd_is_idle = 0;
5499 	}
5500 #endif
5501 	if (rack->rc_gp_dyn_mul &&
5502 	    (rack->use_fixed_rate == 0) &&
5503 	    (rack->rc_always_pace)) {
5504 		/*
5505 		 * Do we count this as if a probe-rtt just
5506 		 * finished?
5507 		 */
5508 		uint32_t time_idle, idle_min;
5509 
5510 		time_idle = tcp_get_usecs(NULL) - rack->r_ctl.rc_went_idle_time;
5511 		idle_min = rack_min_probertt_hold;
5512 		if (rack_probertt_gpsrtt_cnt_div) {
5513 			uint64_t extra;
5514 			extra = (uint64_t)rack->r_ctl.rc_gp_srtt *
5515 				(uint64_t)rack_probertt_gpsrtt_cnt_mul;
5516 			extra /= (uint64_t)rack_probertt_gpsrtt_cnt_div;
5517 			idle_min += (uint32_t)extra;
5518 		}
5519 		if (time_idle >= idle_min) {
5520 			/* Yes, we count it as a probe-rtt. */
5521 			uint32_t us_cts;
5522 
5523 			us_cts = tcp_get_usecs(NULL);
5524 			if (rack->in_probe_rtt == 0) {
5525 				rack->r_ctl.rc_lower_rtt_us_cts = us_cts;
5526 				rack->r_ctl.rc_time_probertt_entered = rack->r_ctl.rc_lower_rtt_us_cts;
5527 				rack->r_ctl.rc_time_probertt_starts = rack->r_ctl.rc_lower_rtt_us_cts;
5528 				rack->r_ctl.rc_time_of_last_probertt = rack->r_ctl.rc_lower_rtt_us_cts;
5529 			} else {
5530 				rack_exit_probertt(rack, us_cts);
5531 			}
5532 		}
5533 	}
5534 	rack->rc_in_persist = 0;
5535 	rack->r_ctl.rc_went_idle_time = 0;
5536 	tp->t_rxtshift = 0;
5537 	RACK_TCPT_RANGESET(tp->t_rxtcur, RACK_REXMTVAL(tp),
5538 	   rack_rto_min, rack_rto_max, rack->r_ctl.timer_slop);
5539 	rack->r_ctl.rc_agg_delayed = 0;
5540 	rack->r_early = 0;
5541 	rack->r_late = 0;
5542 	rack->r_ctl.rc_agg_early = 0;
5543 }
5544 
5545 static void
5546 rack_log_hpts_diag(struct tcp_rack *rack, uint32_t cts,
5547 		   struct hpts_diag *diag, struct timeval *tv)
5548 {
5549 	if (rack_verbose_logging && rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
5550 		union tcp_log_stackspecific log;
5551 
5552 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
5553 		log.u_bbr.flex1 = diag->p_nxt_slot;
5554 		log.u_bbr.flex2 = diag->p_cur_slot;
5555 		log.u_bbr.flex3 = diag->slot_req;
5556 		log.u_bbr.flex4 = diag->inp_hptsslot;
5557 		log.u_bbr.flex5 = diag->slot_remaining;
5558 		log.u_bbr.flex6 = diag->need_new_to;
5559 		log.u_bbr.flex7 = diag->p_hpts_active;
5560 		log.u_bbr.flex8 = diag->p_on_min_sleep;
5561 		/* Hijack other fields as needed */
5562 		log.u_bbr.epoch = diag->have_slept;
5563 		log.u_bbr.lt_epoch = diag->yet_to_sleep;
5564 		log.u_bbr.pkts_out = diag->co_ret;
5565 		log.u_bbr.applimited = diag->hpts_sleep_time;
5566 		log.u_bbr.delivered = diag->p_prev_slot;
5567 		log.u_bbr.inflight = diag->p_runningslot;
5568 		log.u_bbr.bw_inuse = diag->wheel_slot;
5569 		log.u_bbr.rttProp = diag->wheel_cts;
5570 		log.u_bbr.timeStamp = cts;
5571 		log.u_bbr.delRate = diag->maxslots;
5572 		log.u_bbr.cur_del_rate = diag->p_curtick;
5573 		log.u_bbr.cur_del_rate <<= 32;
5574 		log.u_bbr.cur_del_rate |= diag->p_lasttick;
5575 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
5576 		    &rack->rc_inp->inp_socket->so_rcv,
5577 		    &rack->rc_inp->inp_socket->so_snd,
5578 		    BBR_LOG_HPTSDIAG, 0,
5579 		    0, &log, false, tv);
5580 	}
5581 
5582 }
5583 
5584 static void
5585 rack_log_wakeup(struct tcpcb *tp, struct tcp_rack *rack, struct sockbuf *sb, uint32_t len, int type)
5586 {
5587 	if (rack_verbose_logging && rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
5588 		union tcp_log_stackspecific log;
5589 		struct timeval tv;
5590 
5591 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
5592 		log.u_bbr.flex1 = sb->sb_flags;
5593 		log.u_bbr.flex2 = len;
5594 		log.u_bbr.flex3 = sb->sb_state;
5595 		log.u_bbr.flex8 = type;
5596 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
5597 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
5598 		    &rack->rc_inp->inp_socket->so_rcv,
5599 		    &rack->rc_inp->inp_socket->so_snd,
5600 		    TCP_LOG_SB_WAKE, 0,
5601 		    len, &log, false, &tv);
5602 	}
5603 }
5604 
5605 static void
5606 rack_start_hpts_timer(struct tcp_rack *rack, struct tcpcb *tp, uint32_t cts,
5607       int32_t slot, uint32_t tot_len_this_send, int sup_rack)
5608 {
5609 	struct hpts_diag diag;
5610 	struct inpcb *inp = tptoinpcb(tp);
5611 	struct timeval tv;
5612 	uint32_t delayed_ack = 0;
5613 	uint32_t hpts_timeout;
5614 	uint32_t entry_slot = slot;
5615 	uint8_t stopped;
5616 	uint32_t left = 0;
5617 	uint32_t us_cts;
5618 
5619 	if ((tp->t_state == TCPS_CLOSED) ||
5620 	    (tp->t_state == TCPS_LISTEN)) {
5621 		return;
5622 	}
5623 	if (tcp_in_hpts(inp)) {
5624 		/* Already on the pacer */
5625 		return;
5626 	}
5627 	stopped = rack->rc_tmr_stopped;
5628 	if (stopped && TSTMP_GT(rack->r_ctl.rc_timer_exp, cts)) {
5629 		left = rack->r_ctl.rc_timer_exp - cts;
5630 	}
5631 	rack->r_ctl.rc_timer_exp = 0;
5632 	rack->r_ctl.rc_hpts_flags = 0;
5633 	us_cts = tcp_get_usecs(&tv);
5634 	/* Now early/late accounting */
5635 	rack_log_pacing_delay_calc(rack, entry_slot, slot, 0, 0, 0, 26, __LINE__, NULL, 0);
5636 	if (rack->r_early && (rack->rc_ack_can_sendout_data == 0)) {
5637 		/*
5638 		 * We have a early carry over set,
5639 		 * we can always add more time so we
5640 		 * can always make this compensation.
5641 		 *
5642 		 * Note if ack's are allowed to wake us do not
5643 		 * penalize the next timer for being awoke
5644 		 * by an ack aka the rc_agg_early (non-paced mode).
5645 		 */
5646 		slot += rack->r_ctl.rc_agg_early;
5647 		rack->r_early = 0;
5648 		rack->r_ctl.rc_agg_early = 0;
5649 	}
5650 	if (rack->r_late) {
5651 		/*
5652 		 * This is harder, we can
5653 		 * compensate some but it
5654 		 * really depends on what
5655 		 * the current pacing time is.
5656 		 */
5657 		if (rack->r_ctl.rc_agg_delayed >= slot) {
5658 			/*
5659 			 * We can't compensate for it all.
5660 			 * And we have to have some time
5661 			 * on the clock. We always have a min
5662 			 * 10 slots (10 x 10 i.e. 100 usecs).
5663 			 */
5664 			if (slot <= HPTS_TICKS_PER_SLOT) {
5665 				/* We gain delay */
5666 				rack->r_ctl.rc_agg_delayed += (HPTS_TICKS_PER_SLOT - slot);
5667 				slot = HPTS_TICKS_PER_SLOT;
5668 			} else {
5669 				/* We take off some */
5670 				rack->r_ctl.rc_agg_delayed -= (slot - HPTS_TICKS_PER_SLOT);
5671 				slot = HPTS_TICKS_PER_SLOT;
5672 			}
5673 		} else {
5674 			slot -= rack->r_ctl.rc_agg_delayed;
5675 			rack->r_ctl.rc_agg_delayed = 0;
5676 			/* Make sure we have 100 useconds at minimum */
5677 			if (slot < HPTS_TICKS_PER_SLOT) {
5678 				rack->r_ctl.rc_agg_delayed = HPTS_TICKS_PER_SLOT - slot;
5679 				slot = HPTS_TICKS_PER_SLOT;
5680 			}
5681 			if (rack->r_ctl.rc_agg_delayed == 0)
5682 				rack->r_late = 0;
5683 		}
5684 	}
5685 	if (slot) {
5686 		/* We are pacing too */
5687 		rack->r_ctl.rc_hpts_flags |= PACE_PKT_OUTPUT;
5688 	}
5689 	hpts_timeout = rack_timer_start(tp, rack, cts, sup_rack);
5690 #ifdef NETFLIX_EXP_DETECTION
5691 	if (rack->sack_attack_disable &&
5692 	    (slot < tcp_sad_pacing_interval)) {
5693 		/*
5694 		 * We have a potential attacker on
5695 		 * the line. We have possibly some
5696 		 * (or now) pacing time set. We want to
5697 		 * slow down the processing of sacks by some
5698 		 * amount (if it is an attacker). Set the default
5699 		 * slot for attackers in place (unless the orginal
5700 		 * interval is longer). Its stored in
5701 		 * micro-seconds, so lets convert to msecs.
5702 		 */
5703 		slot = tcp_sad_pacing_interval;
5704 	}
5705 #endif
5706 	if (tp->t_flags & TF_DELACK) {
5707 		delayed_ack = TICKS_2_USEC(tcp_delacktime);
5708 		rack->r_ctl.rc_hpts_flags |= PACE_TMR_DELACK;
5709 	}
5710 	if (delayed_ack && ((hpts_timeout == 0) ||
5711 			    (delayed_ack < hpts_timeout)))
5712 		hpts_timeout = delayed_ack;
5713 	else
5714 		rack->r_ctl.rc_hpts_flags &= ~PACE_TMR_DELACK;
5715 	/*
5716 	 * If no timers are going to run and we will fall off the hptsi
5717 	 * wheel, we resort to a keep-alive timer if its configured.
5718 	 */
5719 	if ((hpts_timeout == 0) &&
5720 	    (slot == 0)) {
5721 		if ((V_tcp_always_keepalive || inp->inp_socket->so_options & SO_KEEPALIVE) &&
5722 		    (tp->t_state <= TCPS_CLOSING)) {
5723 			/*
5724 			 * Ok we have no timer (persists, rack, tlp, rxt  or
5725 			 * del-ack), we don't have segments being paced. So
5726 			 * all that is left is the keepalive timer.
5727 			 */
5728 			if (TCPS_HAVEESTABLISHED(tp->t_state)) {
5729 				/* Get the established keep-alive time */
5730 				hpts_timeout = TICKS_2_USEC(TP_KEEPIDLE(tp));
5731 			} else {
5732 				/*
5733 				 * Get the initial setup keep-alive time,
5734 				 * note that this is probably not going to
5735 				 * happen, since rack will be running a rxt timer
5736 				 * if a SYN of some sort is outstanding. It is
5737 				 * actually handled in rack_timeout_rxt().
5738 				 */
5739 				hpts_timeout = TICKS_2_USEC(TP_KEEPINIT(tp));
5740 			}
5741 			rack->r_ctl.rc_hpts_flags |= PACE_TMR_KEEP;
5742 			if (rack->in_probe_rtt) {
5743 				/*
5744 				 * We want to instead not wake up a long time from
5745 				 * now but to wake up about the time we would
5746 				 * exit probe-rtt and initiate a keep-alive ack.
5747 				 * This will get us out of probe-rtt and update
5748 				 * our min-rtt.
5749 				 */
5750 				hpts_timeout = rack_min_probertt_hold;
5751 			}
5752 		}
5753 	}
5754 	if (left && (stopped & (PACE_TMR_KEEP | PACE_TMR_DELACK)) ==
5755 	    (rack->r_ctl.rc_hpts_flags & PACE_TMR_MASK)) {
5756 		/*
5757 		 * RACK, TLP, persists and RXT timers all are restartable
5758 		 * based on actions input .. i.e we received a packet (ack
5759 		 * or sack) and that changes things (rw, or snd_una etc).
5760 		 * Thus we can restart them with a new value. For
5761 		 * keep-alive, delayed_ack we keep track of what was left
5762 		 * and restart the timer with a smaller value.
5763 		 */
5764 		if (left < hpts_timeout)
5765 			hpts_timeout = left;
5766 	}
5767 	if (hpts_timeout) {
5768 		/*
5769 		 * Hack alert for now we can't time-out over 2,147,483
5770 		 * seconds (a bit more than 596 hours), which is probably ok
5771 		 * :).
5772 		 */
5773 		if (hpts_timeout > 0x7ffffffe)
5774 			hpts_timeout = 0x7ffffffe;
5775 		rack->r_ctl.rc_timer_exp = cts + hpts_timeout;
5776 	}
5777 	rack_log_pacing_delay_calc(rack, entry_slot, slot, hpts_timeout, 0, 0, 27, __LINE__, NULL, 0);
5778 	if ((rack->gp_ready == 0) &&
5779 	    (rack->use_fixed_rate == 0) &&
5780 	    (hpts_timeout < slot) &&
5781 	    (rack->r_ctl.rc_hpts_flags & (PACE_TMR_TLP|PACE_TMR_RXT))) {
5782 		/*
5783 		 * We have no good estimate yet for the
5784 		 * old clunky burst mitigation or the
5785 		 * real pacing. And the tlp or rxt is smaller
5786 		 * than the pacing calculation. Lets not
5787 		 * pace that long since we know the calculation
5788 		 * so far is not accurate.
5789 		 */
5790 		slot = hpts_timeout;
5791 	}
5792 	/**
5793 	 * Turn off all the flags for queuing by default. The
5794 	 * flags have important meanings to what happens when
5795 	 * LRO interacts with the transport. Most likely (by default now)
5796 	 * mbuf_queueing and ack compression are on. So the transport
5797 	 * has a couple of flags that control what happens (if those
5798 	 * are not on then these flags won't have any effect since it
5799 	 * won't go through the queuing LRO path).
5800 	 *
5801 	 * INP_MBUF_QUEUE_READY - This flags says that I am busy
5802 	 *                        pacing output, so don't disturb. But
5803 	 *                        it also means LRO can wake me if there
5804 	 *                        is a SACK arrival.
5805 	 *
5806 	 * INP_DONT_SACK_QUEUE - This flag is used in conjunction
5807 	 *                       with the above flag (QUEUE_READY) and
5808 	 *                       when present it says don't even wake me
5809 	 *                       if a SACK arrives.
5810 	 *
5811 	 * The idea behind these flags is that if we are pacing we
5812 	 * set the MBUF_QUEUE_READY and only get woken up if
5813 	 * a SACK arrives (which could change things) or if
5814 	 * our pacing timer expires. If, however, we have a rack
5815 	 * timer running, then we don't even want a sack to wake
5816 	 * us since the rack timer has to expire before we can send.
5817 	 *
5818 	 * Other cases should usually have none of the flags set
5819 	 * so LRO can call into us.
5820 	 */
5821 	inp->inp_flags2 &= ~(INP_DONT_SACK_QUEUE|INP_MBUF_QUEUE_READY);
5822 	if (slot) {
5823 		rack->r_ctl.rc_last_output_to = us_cts + slot;
5824 		/*
5825 		 * A pacing timer (slot) is being set, in
5826 		 * such a case we cannot send (we are blocked by
5827 		 * the timer). So lets tell LRO that it should not
5828 		 * wake us unless there is a SACK. Note this only
5829 		 * will be effective if mbuf queueing is on or
5830 		 * compressed acks are being processed.
5831 		 */
5832 		inp->inp_flags2 |= INP_MBUF_QUEUE_READY;
5833 		/*
5834 		 * But wait if we have a Rack timer running
5835 		 * even a SACK should not disturb us (with
5836 		 * the exception of r_rr_config 3).
5837 		 */
5838 		if ((rack->r_ctl.rc_hpts_flags & PACE_TMR_RACK) &&
5839 		    (rack->r_rr_config != 3))
5840 			inp->inp_flags2 |= INP_DONT_SACK_QUEUE;
5841 		if (rack->rc_ack_can_sendout_data) {
5842 			/*
5843 			 * Ahh but wait, this is that special case
5844 			 * where the pacing timer can be disturbed
5845 			 * backout the changes (used for non-paced
5846 			 * burst limiting).
5847 			 */
5848 			inp->inp_flags2 &= ~(INP_DONT_SACK_QUEUE|INP_MBUF_QUEUE_READY);
5849 		}
5850 		if ((rack->use_rack_rr) &&
5851 		    (rack->r_rr_config < 2) &&
5852 		    ((hpts_timeout) && (hpts_timeout < slot))) {
5853 			/*
5854 			 * Arrange for the hpts to kick back in after the
5855 			 * t-o if the t-o does not cause a send.
5856 			 */
5857 			(void)tcp_hpts_insert_diag(inp, HPTS_USEC_TO_SLOTS(hpts_timeout),
5858 						   __LINE__, &diag);
5859 			rack_log_hpts_diag(rack, us_cts, &diag, &tv);
5860 			rack_log_to_start(rack, cts, hpts_timeout, slot, 0);
5861 		} else {
5862 			(void)tcp_hpts_insert_diag(inp, HPTS_USEC_TO_SLOTS(slot),
5863 						   __LINE__, &diag);
5864 			rack_log_hpts_diag(rack, us_cts, &diag, &tv);
5865 			rack_log_to_start(rack, cts, hpts_timeout, slot, 1);
5866 		}
5867 	} else if (hpts_timeout) {
5868 		/*
5869 		 * With respect to inp_flags2 here, lets let any new acks wake
5870 		 * us up here. Since we are not pacing (no pacing timer), output
5871 		 * can happen so we should let it. If its a Rack timer, then any inbound
5872 		 * packet probably won't change the sending (we will be blocked)
5873 		 * but it may change the prr stats so letting it in (the set defaults
5874 		 * at the start of this block) are good enough.
5875 		 */
5876 		(void)tcp_hpts_insert_diag(inp, HPTS_USEC_TO_SLOTS(hpts_timeout),
5877 					   __LINE__, &diag);
5878 		rack_log_hpts_diag(rack, us_cts, &diag, &tv);
5879 		rack_log_to_start(rack, cts, hpts_timeout, slot, 0);
5880 	} else {
5881 		/* No timer starting */
5882 #ifdef INVARIANTS
5883 		if (SEQ_GT(tp->snd_max, tp->snd_una)) {
5884 			panic("tp:%p rack:%p tlts:%d cts:%u slot:%u pto:%u -- no timer started?",
5885 			    tp, rack, tot_len_this_send, cts, slot, hpts_timeout);
5886 		}
5887 #endif
5888 	}
5889 	rack->rc_tmr_stopped = 0;
5890 	if (slot)
5891 		rack_log_type_bbrsnd(rack, tot_len_this_send, slot, us_cts, &tv);
5892 }
5893 
5894 /*
5895  * RACK Timer, here we simply do logging and house keeping.
5896  * the normal rack_output() function will call the
5897  * appropriate thing to check if we need to do a RACK retransmit.
5898  * We return 1, saying don't proceed with rack_output only
5899  * when all timers have been stopped (destroyed PCB?).
5900  */
5901 static int
5902 rack_timeout_rack(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cts)
5903 {
5904 	/*
5905 	 * This timer simply provides an internal trigger to send out data.
5906 	 * The check_recovery_mode call will see if there are needed
5907 	 * retransmissions, if so we will enter fast-recovery. The output
5908 	 * call may or may not do the same thing depending on sysctl
5909 	 * settings.
5910 	 */
5911 	struct rack_sendmap *rsm;
5912 
5913 	if (tp->t_timers->tt_flags & TT_STOPPED) {
5914 		return (1);
5915 	}
5916 	counter_u64_add(rack_to_tot, 1);
5917 	if (rack->r_state && (rack->r_state != tp->t_state))
5918 		rack_set_state(tp, rack);
5919 	rack->rc_on_min_to = 0;
5920 	rsm = rack_check_recovery_mode(tp, cts);
5921 	rack_log_to_event(rack, RACK_TO_FRM_RACK, rsm);
5922 	if (rsm) {
5923 		rack->r_ctl.rc_resend = rsm;
5924 		rack->r_timer_override = 1;
5925 		if (rack->use_rack_rr) {
5926 			/*
5927 			 * Don't accumulate extra pacing delay
5928 			 * we are allowing the rack timer to
5929 			 * over-ride pacing i.e. rrr takes precedence
5930 			 * if the pacing interval is longer than the rrr
5931 			 * time (in other words we get the min pacing
5932 			 * time versus rrr pacing time).
5933 			 */
5934 			rack->r_ctl.rc_hpts_flags &= ~PACE_PKT_OUTPUT;
5935 		}
5936 	}
5937 	rack->r_ctl.rc_hpts_flags &= ~PACE_TMR_RACK;
5938 	if (rsm == NULL) {
5939 		/* restart a timer and return 1 */
5940 		rack_start_hpts_timer(rack, tp, cts,
5941 				      0, 0, 0);
5942 		return (1);
5943 	}
5944 	return (0);
5945 }
5946 
5947 static void
5948 rack_adjust_orig_mlen(struct rack_sendmap *rsm)
5949 {
5950 	if (rsm->m->m_len > rsm->orig_m_len) {
5951 		/*
5952 		 * Mbuf grew, caused by sbcompress, our offset does
5953 		 * not change.
5954 		 */
5955 		rsm->orig_m_len = rsm->m->m_len;
5956 	} else if (rsm->m->m_len < rsm->orig_m_len) {
5957 		/*
5958 		 * Mbuf shrank, trimmed off the top by an ack, our
5959 		 * offset changes.
5960 		 */
5961 		rsm->soff -= (rsm->orig_m_len - rsm->m->m_len);
5962 		rsm->orig_m_len = rsm->m->m_len;
5963 	}
5964 }
5965 
5966 static void
5967 rack_setup_offset_for_rsm(struct rack_sendmap *src_rsm, struct rack_sendmap *rsm)
5968 {
5969 	struct mbuf *m;
5970 	uint32_t soff;
5971 
5972 	if (src_rsm->m && (src_rsm->orig_m_len != src_rsm->m->m_len)) {
5973 		/* Fix up the orig_m_len and possibly the mbuf offset */
5974 		rack_adjust_orig_mlen(src_rsm);
5975 	}
5976 	m = src_rsm->m;
5977 	soff = src_rsm->soff + (src_rsm->r_end - src_rsm->r_start);
5978 	while (soff >= m->m_len) {
5979 		/* Move out past this mbuf */
5980 		soff -= m->m_len;
5981 		m = m->m_next;
5982 		KASSERT((m != NULL),
5983 			("rsm:%p nrsm:%p hit at soff:%u null m",
5984 			 src_rsm, rsm, soff));
5985 	}
5986 	rsm->m = m;
5987 	rsm->soff = soff;
5988 	rsm->orig_m_len = m->m_len;
5989 }
5990 
5991 static __inline void
5992 rack_clone_rsm(struct tcp_rack *rack, struct rack_sendmap *nrsm,
5993 	       struct rack_sendmap *rsm, uint32_t start)
5994 {
5995 	int idx;
5996 
5997 	nrsm->r_start = start;
5998 	nrsm->r_end = rsm->r_end;
5999 	nrsm->r_rtr_cnt = rsm->r_rtr_cnt;
6000 	nrsm->r_flags = rsm->r_flags;
6001 	nrsm->r_dupack = rsm->r_dupack;
6002 	nrsm->r_no_rtt_allowed = rsm->r_no_rtt_allowed;
6003 	nrsm->r_rtr_bytes = 0;
6004 	nrsm->r_fas = rsm->r_fas;
6005 	rsm->r_end = nrsm->r_start;
6006 	nrsm->r_just_ret = rsm->r_just_ret;
6007 	for (idx = 0; idx < nrsm->r_rtr_cnt; idx++) {
6008 		nrsm->r_tim_lastsent[idx] = rsm->r_tim_lastsent[idx];
6009 	}
6010 	/* Now if we have SYN flag we keep it on the left edge */
6011 	if (nrsm->r_flags & RACK_HAS_SYN)
6012 		nrsm->r_flags &= ~RACK_HAS_SYN;
6013 	/* Now if we have a FIN flag we keep it on the right edge */
6014 	if (rsm->r_flags & RACK_HAS_FIN)
6015 		rsm->r_flags &= ~RACK_HAS_FIN;
6016 	/* Push bit must go to the right edge as well */
6017 	if (rsm->r_flags & RACK_HAD_PUSH)
6018 		rsm->r_flags &= ~RACK_HAD_PUSH;
6019 	/* Clone over the state of the hw_tls flag */
6020 	nrsm->r_hw_tls = rsm->r_hw_tls;
6021 	/*
6022 	 * Now we need to find nrsm's new location in the mbuf chain
6023 	 * we basically calculate a new offset, which is soff +
6024 	 * how much is left in original rsm. Then we walk out the mbuf
6025 	 * chain to find the righ position, it may be the same mbuf
6026 	 * or maybe not.
6027 	 */
6028 	KASSERT(((rsm->m != NULL) ||
6029 		 (rsm->r_flags & (RACK_HAS_SYN|RACK_HAS_FIN))),
6030 		("rsm:%p nrsm:%p rack:%p -- rsm->m is NULL?", rsm, nrsm, rack));
6031 	if (rsm->m)
6032 		rack_setup_offset_for_rsm(rsm, nrsm);
6033 }
6034 
6035 static struct rack_sendmap *
6036 rack_merge_rsm(struct tcp_rack *rack,
6037 	       struct rack_sendmap *l_rsm,
6038 	       struct rack_sendmap *r_rsm)
6039 {
6040 	/*
6041 	 * We are merging two ack'd RSM's,
6042 	 * the l_rsm is on the left (lower seq
6043 	 * values) and the r_rsm is on the right
6044 	 * (higher seq value). The simplest way
6045 	 * to merge these is to move the right
6046 	 * one into the left. I don't think there
6047 	 * is any reason we need to try to find
6048 	 * the oldest (or last oldest retransmitted).
6049 	 */
6050 #ifdef INVARIANTS
6051 	struct rack_sendmap *rm;
6052 #endif
6053 	rack_log_map_chg(rack->rc_tp, rack, NULL,
6054 			 l_rsm, r_rsm, MAP_MERGE, r_rsm->r_end, __LINE__);
6055 	l_rsm->r_end = r_rsm->r_end;
6056 	if (l_rsm->r_dupack < r_rsm->r_dupack)
6057 		l_rsm->r_dupack = r_rsm->r_dupack;
6058 	if (r_rsm->r_rtr_bytes)
6059 		l_rsm->r_rtr_bytes += r_rsm->r_rtr_bytes;
6060 	if (r_rsm->r_in_tmap) {
6061 		/* This really should not happen */
6062 		TAILQ_REMOVE(&rack->r_ctl.rc_tmap, r_rsm, r_tnext);
6063 		r_rsm->r_in_tmap = 0;
6064 	}
6065 
6066 	/* Now the flags */
6067 	if (r_rsm->r_flags & RACK_HAS_FIN)
6068 		l_rsm->r_flags |= RACK_HAS_FIN;
6069 	if (r_rsm->r_flags & RACK_TLP)
6070 		l_rsm->r_flags |= RACK_TLP;
6071 	if (r_rsm->r_flags & RACK_RWND_COLLAPSED)
6072 		l_rsm->r_flags |= RACK_RWND_COLLAPSED;
6073 	if ((r_rsm->r_flags & RACK_APP_LIMITED)  &&
6074 	    ((l_rsm->r_flags & RACK_APP_LIMITED) == 0)) {
6075 		/*
6076 		 * If both are app-limited then let the
6077 		 * free lower the count. If right is app
6078 		 * limited and left is not, transfer.
6079 		 */
6080 		l_rsm->r_flags |= RACK_APP_LIMITED;
6081 		r_rsm->r_flags &= ~RACK_APP_LIMITED;
6082 		if (r_rsm == rack->r_ctl.rc_first_appl)
6083 			rack->r_ctl.rc_first_appl = l_rsm;
6084 	}
6085 #ifndef INVARIANTS
6086 	(void)RB_REMOVE(rack_rb_tree_head, &rack->r_ctl.rc_mtree, r_rsm);
6087 #else
6088 	rm = RB_REMOVE(rack_rb_tree_head, &rack->r_ctl.rc_mtree, r_rsm);
6089 	if (rm != r_rsm) {
6090 		panic("removing head in rack:%p rsm:%p rm:%p",
6091 		      rack, r_rsm, rm);
6092 	}
6093 #endif
6094 	if ((r_rsm->r_limit_type == 0) && (l_rsm->r_limit_type != 0)) {
6095 		/* Transfer the split limit to the map we free */
6096 		r_rsm->r_limit_type = l_rsm->r_limit_type;
6097 		l_rsm->r_limit_type = 0;
6098 	}
6099 	rack_free(rack, r_rsm);
6100 	return (l_rsm);
6101 }
6102 
6103 /*
6104  * TLP Timer, here we simply setup what segment we want to
6105  * have the TLP expire on, the normal rack_output() will then
6106  * send it out.
6107  *
6108  * We return 1, saying don't proceed with rack_output only
6109  * when all timers have been stopped (destroyed PCB?).
6110  */
6111 static int
6112 rack_timeout_tlp(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cts, uint8_t *doing_tlp)
6113 {
6114 	/*
6115 	 * Tail Loss Probe.
6116 	 */
6117 	struct rack_sendmap *rsm = NULL;
6118 #ifdef INVARIANTS
6119 	struct rack_sendmap *insret;
6120 #endif
6121 	struct socket *so = tptosocket(tp);
6122 	uint32_t amm;
6123 	uint32_t out, avail;
6124 	int collapsed_win = 0;
6125 
6126 	if (tp->t_timers->tt_flags & TT_STOPPED) {
6127 		return (1);
6128 	}
6129 	if (TSTMP_LT(cts, rack->r_ctl.rc_timer_exp)) {
6130 		/* Its not time yet */
6131 		return (0);
6132 	}
6133 	if (ctf_progress_timeout_check(tp, true)) {
6134 		rack_log_progress_event(rack, tp, tick, PROGRESS_DROP, __LINE__);
6135 		return (-ETIMEDOUT);	/* tcp_drop() */
6136 	}
6137 	/*
6138 	 * A TLP timer has expired. We have been idle for 2 rtts. So we now
6139 	 * need to figure out how to force a full MSS segment out.
6140 	 */
6141 	rack_log_to_event(rack, RACK_TO_FRM_TLP, NULL);
6142 	rack->r_ctl.retran_during_recovery = 0;
6143 	rack->r_ctl.dsack_byte_cnt = 0;
6144 	counter_u64_add(rack_tlp_tot, 1);
6145 	if (rack->r_state && (rack->r_state != tp->t_state))
6146 		rack_set_state(tp, rack);
6147 	avail = sbavail(&so->so_snd);
6148 	out = tp->snd_max - tp->snd_una;
6149 	if ((out > tp->snd_wnd) || rack->rc_has_collapsed) {
6150 		/* special case, we need a retransmission */
6151 		collapsed_win = 1;
6152 		goto need_retran;
6153 	}
6154 	if (rack->r_ctl.dsack_persist && (rack->r_ctl.rc_tlp_cnt_out >= 1)) {
6155 		rack->r_ctl.dsack_persist--;
6156 		if (rack->r_ctl.num_dsack && (rack->r_ctl.dsack_persist == 0)) {
6157 			rack->r_ctl.num_dsack = 0;
6158 		}
6159 		rack_log_dsack_event(rack, 1, __LINE__, 0, 0);
6160 	}
6161 	if ((tp->t_flags & TF_GPUTINPROG) &&
6162 	    (rack->r_ctl.rc_tlp_cnt_out == 1)) {
6163 		/*
6164 		 * If this is the second in a row
6165 		 * TLP and we are doing a measurement
6166 		 * its time to abandon the measurement.
6167 		 * Something is likely broken on
6168 		 * the clients network and measuring a
6169 		 * broken network does us no good.
6170 		 */
6171 		tp->t_flags &= ~TF_GPUTINPROG;
6172 		rack_log_pacing_delay_calc(rack, (tp->gput_ack - tp->gput_seq) /*flex2*/,
6173 					   rack->r_ctl.rc_gp_srtt /*flex1*/,
6174 					   tp->gput_seq,
6175 					   0, 0, 18, __LINE__, NULL, 0);
6176 	}
6177 	/*
6178 	 * Check our send oldest always settings, and if
6179 	 * there is an oldest to send jump to the need_retran.
6180 	 */
6181 	if (rack_always_send_oldest && (TAILQ_EMPTY(&rack->r_ctl.rc_tmap) == 0))
6182 		goto need_retran;
6183 
6184 	if (avail > out) {
6185 		/* New data is available */
6186 		amm = avail - out;
6187 		if (amm > ctf_fixed_maxseg(tp)) {
6188 			amm = ctf_fixed_maxseg(tp);
6189 			if ((amm + out) > tp->snd_wnd) {
6190 				/* We are rwnd limited */
6191 				goto need_retran;
6192 			}
6193 		} else if (amm < ctf_fixed_maxseg(tp)) {
6194 			/* not enough to fill a MTU */
6195 			goto need_retran;
6196 		}
6197 		if (IN_FASTRECOVERY(tp->t_flags)) {
6198 			/* Unlikely */
6199 			if (rack->rack_no_prr == 0) {
6200 				if (out + amm <= tp->snd_wnd) {
6201 					rack->r_ctl.rc_prr_sndcnt = amm;
6202 					rack->r_ctl.rc_tlp_new_data = amm;
6203 					rack_log_to_prr(rack, 4, 0, __LINE__);
6204 				}
6205 			} else
6206 				goto need_retran;
6207 		} else {
6208 			/* Set the send-new override */
6209 			if (out + amm <= tp->snd_wnd)
6210 				rack->r_ctl.rc_tlp_new_data = amm;
6211 			else
6212 				goto need_retran;
6213 		}
6214 		rack->r_ctl.rc_tlpsend = NULL;
6215 		counter_u64_add(rack_tlp_newdata, 1);
6216 		goto send;
6217 	}
6218 need_retran:
6219 	/*
6220 	 * Ok we need to arrange the last un-acked segment to be re-sent, or
6221 	 * optionally the first un-acked segment.
6222 	 */
6223 	if (collapsed_win == 0) {
6224 		if (rack_always_send_oldest)
6225 			rsm = TAILQ_FIRST(&rack->r_ctl.rc_tmap);
6226 		else {
6227 			rsm = RB_MAX(rack_rb_tree_head, &rack->r_ctl.rc_mtree);
6228 			if (rsm && (rsm->r_flags & (RACK_ACKED | RACK_HAS_FIN))) {
6229 				rsm = rack_find_high_nonack(rack, rsm);
6230 			}
6231 		}
6232 		if (rsm == NULL) {
6233 #ifdef TCP_BLACKBOX
6234 			tcp_log_dump_tp_logbuf(tp, "nada counter trips", M_NOWAIT, true);
6235 #endif
6236 			goto out;
6237 		}
6238 	} else {
6239 		/*
6240 		 * We must find the last segment
6241 		 * that was acceptable by the client.
6242 		 */
6243 		RB_FOREACH_REVERSE(rsm, rack_rb_tree_head, &rack->r_ctl.rc_mtree) {
6244 			if ((rsm->r_flags & RACK_RWND_COLLAPSED) == 0) {
6245 				/* Found one */
6246 				break;
6247 			}
6248 		}
6249 		if (rsm == NULL) {
6250 			/* None? if so send the first */
6251 			rsm = RB_MIN(rack_rb_tree_head, &rack->r_ctl.rc_mtree);
6252 			if (rsm == NULL) {
6253 #ifdef TCP_BLACKBOX
6254 				tcp_log_dump_tp_logbuf(tp, "nada counter trips", M_NOWAIT, true);
6255 #endif
6256 				goto out;
6257 			}
6258 		}
6259 	}
6260 	if ((rsm->r_end - rsm->r_start) > ctf_fixed_maxseg(tp)) {
6261 		/*
6262 		 * We need to split this the last segment in two.
6263 		 */
6264 		struct rack_sendmap *nrsm;
6265 
6266 		nrsm = rack_alloc_full_limit(rack);
6267 		if (nrsm == NULL) {
6268 			/*
6269 			 * No memory to split, we will just exit and punt
6270 			 * off to the RXT timer.
6271 			 */
6272 			goto out;
6273 		}
6274 		rack_clone_rsm(rack, nrsm, rsm,
6275 			       (rsm->r_end - ctf_fixed_maxseg(tp)));
6276 		rack_log_map_chg(tp, rack, NULL, rsm, nrsm, MAP_SPLIT, 0, __LINE__);
6277 #ifndef INVARIANTS
6278 		(void)RB_INSERT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, nrsm);
6279 #else
6280 		insret = RB_INSERT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, nrsm);
6281 		if (insret != NULL) {
6282 			panic("Insert in rb tree of %p fails ret:%p rack:%p rsm:%p",
6283 			      nrsm, insret, rack, rsm);
6284 		}
6285 #endif
6286 		if (rsm->r_in_tmap) {
6287 			TAILQ_INSERT_AFTER(&rack->r_ctl.rc_tmap, rsm, nrsm, r_tnext);
6288 			nrsm->r_in_tmap = 1;
6289 		}
6290 		rsm = nrsm;
6291 	}
6292 	rack->r_ctl.rc_tlpsend = rsm;
6293 send:
6294 	/* Make sure output path knows we are doing a TLP */
6295 	*doing_tlp = 1;
6296 	rack->r_timer_override = 1;
6297 	rack->r_ctl.rc_hpts_flags &= ~PACE_TMR_TLP;
6298 	return (0);
6299 out:
6300 	rack->r_ctl.rc_hpts_flags &= ~PACE_TMR_TLP;
6301 	return (0);
6302 }
6303 
6304 /*
6305  * Delayed ack Timer, here we simply need to setup the
6306  * ACK_NOW flag and remove the DELACK flag. From there
6307  * the output routine will send the ack out.
6308  *
6309  * We only return 1, saying don't proceed, if all timers
6310  * are stopped (destroyed PCB?).
6311  */
6312 static int
6313 rack_timeout_delack(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cts)
6314 {
6315 	if (tp->t_timers->tt_flags & TT_STOPPED) {
6316 		return (1);
6317 	}
6318 	rack_log_to_event(rack, RACK_TO_FRM_DELACK, NULL);
6319 	tp->t_flags &= ~TF_DELACK;
6320 	tp->t_flags |= TF_ACKNOW;
6321 	KMOD_TCPSTAT_INC(tcps_delack);
6322 	rack->r_ctl.rc_hpts_flags &= ~PACE_TMR_DELACK;
6323 	return (0);
6324 }
6325 
6326 /*
6327  * Persists timer, here we simply send the
6328  * same thing as a keepalive will.
6329  * the one byte send.
6330  *
6331  * We only return 1, saying don't proceed, if all timers
6332  * are stopped (destroyed PCB?).
6333  */
6334 static int
6335 rack_timeout_persist(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cts)
6336 {
6337 	struct tcptemp *t_template;
6338 	int32_t retval = 1;
6339 
6340 	if (tp->t_timers->tt_flags & TT_STOPPED) {
6341 		return (1);
6342 	}
6343 	if (rack->rc_in_persist == 0)
6344 		return (0);
6345 	if (ctf_progress_timeout_check(tp, false)) {
6346 		tcp_log_end_status(tp, TCP_EI_STATUS_PERSIST_MAX);
6347 		rack_log_progress_event(rack, tp, tick, PROGRESS_DROP, __LINE__);
6348 		counter_u64_add(rack_persists_lost_ends, rack->r_ctl.persist_lost_ends);
6349 		return (-ETIMEDOUT);	/* tcp_drop() */
6350 	}
6351 	/*
6352 	 * Persistence timer into zero window. Force a byte to be output, if
6353 	 * possible.
6354 	 */
6355 	KMOD_TCPSTAT_INC(tcps_persisttimeo);
6356 	/*
6357 	 * Hack: if the peer is dead/unreachable, we do not time out if the
6358 	 * window is closed.  After a full backoff, drop the connection if
6359 	 * the idle time (no responses to probes) reaches the maximum
6360 	 * backoff that we would use if retransmitting.
6361 	 */
6362 	if (tp->t_rxtshift == TCP_MAXRXTSHIFT &&
6363 	    (ticks - tp->t_rcvtime >= tcp_maxpersistidle ||
6364 	     TICKS_2_USEC(ticks - tp->t_rcvtime) >= RACK_REXMTVAL(tp) * tcp_totbackoff)) {
6365 		KMOD_TCPSTAT_INC(tcps_persistdrop);
6366 		tcp_log_end_status(tp, TCP_EI_STATUS_PERSIST_MAX);
6367 		counter_u64_add(rack_persists_lost_ends, rack->r_ctl.persist_lost_ends);
6368 		retval = -ETIMEDOUT;	/* tcp_drop() */
6369 		goto out;
6370 	}
6371 	if ((sbavail(&rack->rc_inp->inp_socket->so_snd) == 0) &&
6372 	    tp->snd_una == tp->snd_max)
6373 		rack_exit_persist(tp, rack, cts);
6374 	rack->r_ctl.rc_hpts_flags &= ~PACE_TMR_PERSIT;
6375 	/*
6376 	 * If the user has closed the socket then drop a persisting
6377 	 * connection after a much reduced timeout.
6378 	 */
6379 	if (tp->t_state > TCPS_CLOSE_WAIT &&
6380 	    (ticks - tp->t_rcvtime) >= TCPTV_PERSMAX) {
6381 		KMOD_TCPSTAT_INC(tcps_persistdrop);
6382 		tcp_log_end_status(tp, TCP_EI_STATUS_PERSIST_MAX);
6383 		counter_u64_add(rack_persists_lost_ends, rack->r_ctl.persist_lost_ends);
6384 		retval = -ETIMEDOUT;	/* tcp_drop() */
6385 		goto out;
6386 	}
6387 	t_template = tcpip_maketemplate(rack->rc_inp);
6388 	if (t_template) {
6389 		/* only set it if we were answered */
6390 		if (rack->forced_ack == 0) {
6391 			rack->forced_ack = 1;
6392 			rack->r_ctl.forced_ack_ts = tcp_get_usecs(NULL);
6393 		} else {
6394 			rack->probe_not_answered = 1;
6395 			counter_u64_add(rack_persists_loss, 1);
6396 			rack->r_ctl.persist_lost_ends++;
6397 		}
6398 		counter_u64_add(rack_persists_sends, 1);
6399 		tcp_respond(tp, t_template->tt_ipgen,
6400 			    &t_template->tt_t, (struct mbuf *)NULL,
6401 			    tp->rcv_nxt, tp->snd_una - 1, 0);
6402 		/* This sends an ack */
6403 		if (tp->t_flags & TF_DELACK)
6404 			tp->t_flags &= ~TF_DELACK;
6405 		free(t_template, M_TEMP);
6406 	}
6407 	if (tp->t_rxtshift < TCP_MAXRXTSHIFT)
6408 		tp->t_rxtshift++;
6409 out:
6410 	rack_log_to_event(rack, RACK_TO_FRM_PERSIST, NULL);
6411 	rack_start_hpts_timer(rack, tp, cts,
6412 			      0, 0, 0);
6413 	return (retval);
6414 }
6415 
6416 /*
6417  * If a keepalive goes off, we had no other timers
6418  * happening. We always return 1 here since this
6419  * routine either drops the connection or sends
6420  * out a segment with respond.
6421  */
6422 static int
6423 rack_timeout_keepalive(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cts)
6424 {
6425 	struct tcptemp *t_template;
6426 	struct inpcb *inp = tptoinpcb(tp);
6427 
6428 	if (tp->t_timers->tt_flags & TT_STOPPED) {
6429 		return (1);
6430 	}
6431 	rack->r_ctl.rc_hpts_flags &= ~PACE_TMR_KEEP;
6432 	rack_log_to_event(rack, RACK_TO_FRM_KEEP, NULL);
6433 	/*
6434 	 * Keep-alive timer went off; send something or drop connection if
6435 	 * idle for too long.
6436 	 */
6437 	KMOD_TCPSTAT_INC(tcps_keeptimeo);
6438 	if (tp->t_state < TCPS_ESTABLISHED)
6439 		goto dropit;
6440 	if ((V_tcp_always_keepalive || inp->inp_socket->so_options & SO_KEEPALIVE) &&
6441 	    tp->t_state <= TCPS_CLOSING) {
6442 		if (ticks - tp->t_rcvtime >= TP_KEEPIDLE(tp) + TP_MAXIDLE(tp))
6443 			goto dropit;
6444 		/*
6445 		 * Send a packet designed to force a response if the peer is
6446 		 * up and reachable: either an ACK if the connection is
6447 		 * still alive, or an RST if the peer has closed the
6448 		 * connection due to timeout or reboot. Using sequence
6449 		 * number tp->snd_una-1 causes the transmitted zero-length
6450 		 * segment to lie outside the receive window; by the
6451 		 * protocol spec, this requires the correspondent TCP to
6452 		 * respond.
6453 		 */
6454 		KMOD_TCPSTAT_INC(tcps_keepprobe);
6455 		t_template = tcpip_maketemplate(inp);
6456 		if (t_template) {
6457 			if (rack->forced_ack == 0) {
6458 				rack->forced_ack = 1;
6459 				rack->r_ctl.forced_ack_ts = tcp_get_usecs(NULL);
6460 			} else {
6461 				rack->probe_not_answered = 1;
6462 			}
6463 			tcp_respond(tp, t_template->tt_ipgen,
6464 			    &t_template->tt_t, (struct mbuf *)NULL,
6465 			    tp->rcv_nxt, tp->snd_una - 1, 0);
6466 			free(t_template, M_TEMP);
6467 		}
6468 	}
6469 	rack_start_hpts_timer(rack, tp, cts, 0, 0, 0);
6470 	return (1);
6471 dropit:
6472 	KMOD_TCPSTAT_INC(tcps_keepdrops);
6473 	tcp_log_end_status(tp, TCP_EI_STATUS_KEEP_MAX);
6474 	return (-ETIMEDOUT);	/* tcp_drop() */
6475 }
6476 
6477 /*
6478  * Retransmit helper function, clear up all the ack
6479  * flags and take care of important book keeping.
6480  */
6481 static void
6482 rack_remxt_tmr(struct tcpcb *tp)
6483 {
6484 	/*
6485 	 * The retransmit timer went off, all sack'd blocks must be
6486 	 * un-acked.
6487 	 */
6488 	struct rack_sendmap *rsm, *trsm = NULL;
6489 	struct tcp_rack *rack;
6490 
6491 	rack = (struct tcp_rack *)tp->t_fb_ptr;
6492 	rack_timer_cancel(tp, rack, tcp_get_usecs(NULL), __LINE__);
6493 	rack_log_to_event(rack, RACK_TO_FRM_TMR, NULL);
6494 	if (rack->r_state && (rack->r_state != tp->t_state))
6495 		rack_set_state(tp, rack);
6496 	/*
6497 	 * Ideally we would like to be able to
6498 	 * mark SACK-PASS on anything not acked here.
6499 	 *
6500 	 * However, if we do that we would burst out
6501 	 * all that data 1ms apart. This would be unwise,
6502 	 * so for now we will just let the normal rxt timer
6503 	 * and tlp timer take care of it.
6504 	 *
6505 	 * Also we really need to stick them back in sequence
6506 	 * order. This way we send in the proper order and any
6507 	 * sacks that come floating in will "re-ack" the data.
6508 	 * To do this we zap the tmap with an INIT and then
6509 	 * walk through and place every rsm in the RB tree
6510 	 * back in its seq ordered place.
6511 	 */
6512 	TAILQ_INIT(&rack->r_ctl.rc_tmap);
6513 	RB_FOREACH(rsm, rack_rb_tree_head, &rack->r_ctl.rc_mtree) {
6514 		rsm->r_dupack = 0;
6515 		rack_log_retran_reason(rack, rsm, __LINE__, 0, 2);
6516 		/* We must re-add it back to the tlist */
6517 		if (trsm == NULL) {
6518 			TAILQ_INSERT_HEAD(&rack->r_ctl.rc_tmap, rsm, r_tnext);
6519 		} else {
6520 			TAILQ_INSERT_AFTER(&rack->r_ctl.rc_tmap, trsm, rsm, r_tnext);
6521 		}
6522 		rsm->r_in_tmap = 1;
6523 		trsm = rsm;
6524 		if (rsm->r_flags & RACK_ACKED)
6525 			rsm->r_flags |= RACK_WAS_ACKED;
6526 		rsm->r_flags &= ~(RACK_ACKED | RACK_SACK_PASSED | RACK_WAS_SACKPASS | RACK_RWND_COLLAPSED);
6527 		rsm->r_flags |= RACK_MUST_RXT;
6528 	}
6529 	/* Clear the count (we just un-acked them) */
6530 	rack->r_ctl.rc_last_timeout_snduna = tp->snd_una;
6531 	rack->r_ctl.rc_sacked = 0;
6532 	rack->r_ctl.rc_sacklast = NULL;
6533 	rack->r_ctl.rc_agg_delayed = 0;
6534 	rack->r_early = 0;
6535 	rack->r_ctl.rc_agg_early = 0;
6536 	rack->r_late = 0;
6537 	/* Clear the tlp rtx mark */
6538 	rack->r_ctl.rc_resend = RB_MIN(rack_rb_tree_head, &rack->r_ctl.rc_mtree);
6539 	if (rack->r_ctl.rc_resend != NULL)
6540 		rack->r_ctl.rc_resend->r_flags |= RACK_TO_REXT;
6541 	rack->r_ctl.rc_prr_sndcnt = 0;
6542 	rack_log_to_prr(rack, 6, 0, __LINE__);
6543 	rack->r_timer_override = 1;
6544 	if ((((tp->t_flags & TF_SACK_PERMIT) == 0)
6545 #ifdef NETFLIX_EXP_DETECTION
6546 	    || (rack->sack_attack_disable != 0)
6547 #endif
6548 		    ) && ((tp->t_flags & TF_SENTFIN) == 0)) {
6549 		/*
6550 		 * For non-sack customers new data
6551 		 * needs to go out as retransmits until
6552 		 * we retransmit up to snd_max.
6553 		 */
6554 		rack->r_must_retran = 1;
6555 		rack->r_ctl.rc_out_at_rto = ctf_flight_size(rack->rc_tp,
6556 						rack->r_ctl.rc_sacked);
6557 	}
6558 	rack->r_ctl.rc_snd_max_at_rto = tp->snd_max;
6559 }
6560 
6561 static void
6562 rack_convert_rtts(struct tcpcb *tp)
6563 {
6564 	if (tp->t_srtt > 1) {
6565 		uint32_t val, frac;
6566 
6567 		val = tp->t_srtt >> TCP_RTT_SHIFT;
6568 		frac = tp->t_srtt & 0x1f;
6569 		tp->t_srtt = TICKS_2_USEC(val);
6570 		/*
6571 		 * frac is the fractional part of the srtt (if any)
6572 		 * but its in ticks and every bit represents
6573 		 * 1/32nd of a hz.
6574 		 */
6575 		if (frac) {
6576 			if (hz == 1000) {
6577 				frac = (((uint64_t)frac * (uint64_t)HPTS_USEC_IN_MSEC) / (uint64_t)TCP_RTT_SCALE);
6578 			} else {
6579 				frac = (((uint64_t)frac * (uint64_t)HPTS_USEC_IN_SEC) / ((uint64_t)(hz) * (uint64_t)TCP_RTT_SCALE));
6580 			}
6581 			tp->t_srtt += frac;
6582 		}
6583 	}
6584 	if (tp->t_rttvar) {
6585 		uint32_t val, frac;
6586 
6587 		val = tp->t_rttvar >> TCP_RTTVAR_SHIFT;
6588 		frac = tp->t_rttvar & 0x1f;
6589 		tp->t_rttvar = TICKS_2_USEC(val);
6590 		/*
6591 		 * frac is the fractional part of the srtt (if any)
6592 		 * but its in ticks and every bit represents
6593 		 * 1/32nd of a hz.
6594 		 */
6595 		if (frac) {
6596 			if (hz == 1000) {
6597 				frac = (((uint64_t)frac * (uint64_t)HPTS_USEC_IN_MSEC) / (uint64_t)TCP_RTT_SCALE);
6598 			} else {
6599 				frac = (((uint64_t)frac * (uint64_t)HPTS_USEC_IN_SEC) / ((uint64_t)(hz) * (uint64_t)TCP_RTT_SCALE));
6600 			}
6601 			tp->t_rttvar += frac;
6602 		}
6603 	}
6604 	tp->t_rxtcur = RACK_REXMTVAL(tp);
6605 	if (TCPS_HAVEESTABLISHED(tp->t_state)) {
6606 		tp->t_rxtcur += TICKS_2_USEC(tcp_rexmit_slop);
6607 	}
6608 	if (tp->t_rxtcur > rack_rto_max) {
6609 		tp->t_rxtcur = rack_rto_max;
6610 	}
6611 }
6612 
6613 static void
6614 rack_cc_conn_init(struct tcpcb *tp)
6615 {
6616 	struct tcp_rack *rack;
6617 	uint32_t srtt;
6618 
6619 	rack = (struct tcp_rack *)tp->t_fb_ptr;
6620 	srtt = tp->t_srtt;
6621 	cc_conn_init(tp);
6622 	/*
6623 	 * Now convert to rack's internal format,
6624 	 * if required.
6625 	 */
6626 	if ((srtt == 0) && (tp->t_srtt != 0))
6627 		rack_convert_rtts(tp);
6628 	/*
6629 	 * We want a chance to stay in slowstart as
6630 	 * we create a connection. TCP spec says that
6631 	 * initially ssthresh is infinite. For our
6632 	 * purposes that is the snd_wnd.
6633 	 */
6634 	if (tp->snd_ssthresh < tp->snd_wnd) {
6635 		tp->snd_ssthresh = tp->snd_wnd;
6636 	}
6637 	/*
6638 	 * We also want to assure a IW worth of
6639 	 * data can get inflight.
6640 	 */
6641 	if (rc_init_window(rack) < tp->snd_cwnd)
6642 		tp->snd_cwnd = rc_init_window(rack);
6643 }
6644 
6645 /*
6646  * Re-transmit timeout! If we drop the PCB we will return 1, otherwise
6647  * we will setup to retransmit the lowest seq number outstanding.
6648  */
6649 static int
6650 rack_timeout_rxt(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cts)
6651 {
6652 	struct inpcb *inp = tptoinpcb(tp);
6653 	int32_t rexmt;
6654 	int32_t retval = 0;
6655 	bool isipv6;
6656 
6657 	if (tp->t_timers->tt_flags & TT_STOPPED) {
6658 		return (1);
6659 	}
6660 	if ((tp->t_flags & TF_GPUTINPROG) &&
6661 	    (tp->t_rxtshift)) {
6662 		/*
6663 		 * We have had a second timeout
6664 		 * measurements on successive rxt's are not profitable.
6665 		 * It is unlikely to be of any use (the network is
6666 		 * broken or the client went away).
6667 		 */
6668 		tp->t_flags &= ~TF_GPUTINPROG;
6669 		rack_log_pacing_delay_calc(rack, (tp->gput_ack - tp->gput_seq) /*flex2*/,
6670 					   rack->r_ctl.rc_gp_srtt /*flex1*/,
6671 					   tp->gput_seq,
6672 					   0, 0, 18, __LINE__, NULL, 0);
6673 	}
6674 	if (ctf_progress_timeout_check(tp, false)) {
6675 		tcp_log_end_status(tp, TCP_EI_STATUS_RETRAN);
6676 		rack_log_progress_event(rack, tp, tick, PROGRESS_DROP, __LINE__);
6677 		return (-ETIMEDOUT);	/* tcp_drop() */
6678 	}
6679 	rack->r_ctl.rc_hpts_flags &= ~PACE_TMR_RXT;
6680 	rack->r_ctl.retran_during_recovery = 0;
6681 	rack->rc_ack_required = 1;
6682 	rack->r_ctl.dsack_byte_cnt = 0;
6683 	if (IN_FASTRECOVERY(tp->t_flags))
6684 		tp->t_flags |= TF_WASFRECOVERY;
6685 	else
6686 		tp->t_flags &= ~TF_WASFRECOVERY;
6687 	if (IN_CONGRECOVERY(tp->t_flags))
6688 		tp->t_flags |= TF_WASCRECOVERY;
6689 	else
6690 		tp->t_flags &= ~TF_WASCRECOVERY;
6691 	if (TCPS_HAVEESTABLISHED(tp->t_state) &&
6692 	    (tp->snd_una == tp->snd_max)) {
6693 		/* Nothing outstanding .. nothing to do */
6694 		return (0);
6695 	}
6696 	if (rack->r_ctl.dsack_persist) {
6697 		rack->r_ctl.dsack_persist--;
6698 		if (rack->r_ctl.num_dsack && (rack->r_ctl.dsack_persist == 0)) {
6699 			rack->r_ctl.num_dsack = 0;
6700 		}
6701 		rack_log_dsack_event(rack, 1, __LINE__, 0, 0);
6702 	}
6703 	/*
6704 	 * Rack can only run one timer  at a time, so we cannot
6705 	 * run a KEEPINIT (gating SYN sending) and a retransmit
6706 	 * timer for the SYN. So if we are in a front state and
6707 	 * have a KEEPINIT timer we need to check the first transmit
6708 	 * against now to see if we have exceeded the KEEPINIT time
6709 	 * (if one is set).
6710 	 */
6711 	if ((TCPS_HAVEESTABLISHED(tp->t_state) == 0) &&
6712 	    (TP_KEEPINIT(tp) != 0)) {
6713 		struct rack_sendmap *rsm;
6714 
6715 		rsm = RB_MIN(rack_rb_tree_head, &rack->r_ctl.rc_mtree);
6716 		if (rsm) {
6717 			/* Ok we have something outstanding to test keepinit with */
6718 			if ((TSTMP_GT(cts, (uint32_t)rsm->r_tim_lastsent[0])) &&
6719 			    ((cts - (uint32_t)rsm->r_tim_lastsent[0]) >= TICKS_2_USEC(TP_KEEPINIT(tp)))) {
6720 				/* We have exceeded the KEEPINIT time */
6721 				tcp_log_end_status(tp, TCP_EI_STATUS_KEEP_MAX);
6722 				goto drop_it;
6723 			}
6724 		}
6725 	}
6726 	/*
6727 	 * Retransmission timer went off.  Message has not been acked within
6728 	 * retransmit interval.  Back off to a longer retransmit interval
6729 	 * and retransmit one segment.
6730 	 */
6731 	rack_remxt_tmr(tp);
6732 	if ((rack->r_ctl.rc_resend == NULL) ||
6733 	    ((rack->r_ctl.rc_resend->r_flags & RACK_RWND_COLLAPSED) == 0)) {
6734 		/*
6735 		 * If the rwnd collapsed on
6736 		 * the one we are retransmitting
6737 		 * it does not count against the
6738 		 * rxt count.
6739 		 */
6740 		tp->t_rxtshift++;
6741 	}
6742 	if (tp->t_rxtshift > TCP_MAXRXTSHIFT) {
6743 		tcp_log_end_status(tp, TCP_EI_STATUS_RETRAN);
6744 drop_it:
6745 		tp->t_rxtshift = TCP_MAXRXTSHIFT;
6746 		KMOD_TCPSTAT_INC(tcps_timeoutdrop);
6747 		/* XXXGL: previously t_softerror was casted to uint16_t */
6748 		MPASS(tp->t_softerror >= 0);
6749 		retval = tp->t_softerror ? -tp->t_softerror : -ETIMEDOUT;
6750 		goto out;	/* tcp_drop() */
6751 	}
6752 	if (tp->t_state == TCPS_SYN_SENT) {
6753 		/*
6754 		 * If the SYN was retransmitted, indicate CWND to be limited
6755 		 * to 1 segment in cc_conn_init().
6756 		 */
6757 		tp->snd_cwnd = 1;
6758 	} else if (tp->t_rxtshift == 1) {
6759 		/*
6760 		 * first retransmit; record ssthresh and cwnd so they can be
6761 		 * recovered if this turns out to be a "bad" retransmit. A
6762 		 * retransmit is considered "bad" if an ACK for this segment
6763 		 * is received within RTT/2 interval; the assumption here is
6764 		 * that the ACK was already in flight.  See "On Estimating
6765 		 * End-to-End Network Path Properties" by Allman and Paxson
6766 		 * for more details.
6767 		 */
6768 		tp->snd_cwnd_prev = tp->snd_cwnd;
6769 		tp->snd_ssthresh_prev = tp->snd_ssthresh;
6770 		tp->snd_recover_prev = tp->snd_recover;
6771 		tp->t_badrxtwin = ticks + (USEC_2_TICKS(tp->t_srtt)/2);
6772 		tp->t_flags |= TF_PREVVALID;
6773 	} else if ((tp->t_flags & TF_RCVD_TSTMP) == 0)
6774 		tp->t_flags &= ~TF_PREVVALID;
6775 	KMOD_TCPSTAT_INC(tcps_rexmttimeo);
6776 	if ((tp->t_state == TCPS_SYN_SENT) ||
6777 	    (tp->t_state == TCPS_SYN_RECEIVED))
6778 		rexmt = RACK_INITIAL_RTO * tcp_backoff[tp->t_rxtshift];
6779 	else
6780 		rexmt = max(rack_rto_min, (tp->t_srtt + (tp->t_rttvar << 2))) * tcp_backoff[tp->t_rxtshift];
6781 
6782 	RACK_TCPT_RANGESET(tp->t_rxtcur, rexmt,
6783 	   max(rack_rto_min, rexmt), rack_rto_max, rack->r_ctl.timer_slop);
6784 	/*
6785 	 * We enter the path for PLMTUD if connection is established or, if
6786 	 * connection is FIN_WAIT_1 status, reason for the last is that if
6787 	 * amount of data we send is very small, we could send it in couple
6788 	 * of packets and process straight to FIN. In that case we won't
6789 	 * catch ESTABLISHED state.
6790 	 */
6791 #ifdef INET6
6792 	isipv6 = (inp->inp_vflag & INP_IPV6) ? true : false;
6793 #else
6794 	isipv6 = false;
6795 #endif
6796 	if (((V_tcp_pmtud_blackhole_detect == 1) ||
6797 	    (V_tcp_pmtud_blackhole_detect == 2 && !isipv6) ||
6798 	    (V_tcp_pmtud_blackhole_detect == 3 && isipv6)) &&
6799 	    ((tp->t_state == TCPS_ESTABLISHED) ||
6800 	    (tp->t_state == TCPS_FIN_WAIT_1))) {
6801 		/*
6802 		 * Idea here is that at each stage of mtu probe (usually,
6803 		 * 1448 -> 1188 -> 524) should be given 2 chances to recover
6804 		 * before further clamping down. 'tp->t_rxtshift % 2 == 0'
6805 		 * should take care of that.
6806 		 */
6807 		if (((tp->t_flags2 & (TF2_PLPMTU_PMTUD | TF2_PLPMTU_MAXSEGSNT)) ==
6808 		    (TF2_PLPMTU_PMTUD | TF2_PLPMTU_MAXSEGSNT)) &&
6809 		    (tp->t_rxtshift >= 2 && tp->t_rxtshift < 6 &&
6810 		    tp->t_rxtshift % 2 == 0)) {
6811 			/*
6812 			 * Enter Path MTU Black-hole Detection mechanism: -
6813 			 * Disable Path MTU Discovery (IP "DF" bit). -
6814 			 * Reduce MTU to lower value than what we negotiated
6815 			 * with peer.
6816 			 */
6817 			if ((tp->t_flags2 & TF2_PLPMTU_BLACKHOLE) == 0) {
6818 				/* Record that we may have found a black hole. */
6819 				tp->t_flags2 |= TF2_PLPMTU_BLACKHOLE;
6820 				/* Keep track of previous MSS. */
6821 				tp->t_pmtud_saved_maxseg = tp->t_maxseg;
6822 			}
6823 
6824 			/*
6825 			 * Reduce the MSS to blackhole value or to the
6826 			 * default in an attempt to retransmit.
6827 			 */
6828 #ifdef INET6
6829 			if (isipv6 &&
6830 			    tp->t_maxseg > V_tcp_v6pmtud_blackhole_mss) {
6831 				/* Use the sysctl tuneable blackhole MSS. */
6832 				tp->t_maxseg = V_tcp_v6pmtud_blackhole_mss;
6833 				KMOD_TCPSTAT_INC(tcps_pmtud_blackhole_activated);
6834 			} else if (isipv6) {
6835 				/* Use the default MSS. */
6836 				tp->t_maxseg = V_tcp_v6mssdflt;
6837 				/*
6838 				 * Disable Path MTU Discovery when we switch
6839 				 * to minmss.
6840 				 */
6841 				tp->t_flags2 &= ~TF2_PLPMTU_PMTUD;
6842 				KMOD_TCPSTAT_INC(tcps_pmtud_blackhole_activated_min_mss);
6843 			}
6844 #endif
6845 #if defined(INET6) && defined(INET)
6846 			else
6847 #endif
6848 #ifdef INET
6849 			if (tp->t_maxseg > V_tcp_pmtud_blackhole_mss) {
6850 				/* Use the sysctl tuneable blackhole MSS. */
6851 				tp->t_maxseg = V_tcp_pmtud_blackhole_mss;
6852 				KMOD_TCPSTAT_INC(tcps_pmtud_blackhole_activated);
6853 			} else {
6854 				/* Use the default MSS. */
6855 				tp->t_maxseg = V_tcp_mssdflt;
6856 				/*
6857 				 * Disable Path MTU Discovery when we switch
6858 				 * to minmss.
6859 				 */
6860 				tp->t_flags2 &= ~TF2_PLPMTU_PMTUD;
6861 				KMOD_TCPSTAT_INC(tcps_pmtud_blackhole_activated_min_mss);
6862 			}
6863 #endif
6864 		} else {
6865 			/*
6866 			 * If further retransmissions are still unsuccessful
6867 			 * with a lowered MTU, maybe this isn't a blackhole
6868 			 * and we restore the previous MSS and blackhole
6869 			 * detection flags. The limit '6' is determined by
6870 			 * giving each probe stage (1448, 1188, 524) 2
6871 			 * chances to recover.
6872 			 */
6873 			if ((tp->t_flags2 & TF2_PLPMTU_BLACKHOLE) &&
6874 			    (tp->t_rxtshift >= 6)) {
6875 				tp->t_flags2 |= TF2_PLPMTU_PMTUD;
6876 				tp->t_flags2 &= ~TF2_PLPMTU_BLACKHOLE;
6877 				tp->t_maxseg = tp->t_pmtud_saved_maxseg;
6878 				KMOD_TCPSTAT_INC(tcps_pmtud_blackhole_failed);
6879 			}
6880 		}
6881 	}
6882 	/*
6883 	 * Disable RFC1323 and SACK if we haven't got any response to
6884 	 * our third SYN to work-around some broken terminal servers
6885 	 * (most of which have hopefully been retired) that have bad VJ
6886 	 * header compression code which trashes TCP segments containing
6887 	 * unknown-to-them TCP options.
6888 	 */
6889 	if (tcp_rexmit_drop_options && (tp->t_state == TCPS_SYN_SENT) &&
6890 	    (tp->t_rxtshift == 3))
6891 		tp->t_flags &= ~(TF_REQ_SCALE|TF_REQ_TSTMP|TF_SACK_PERMIT);
6892 	/*
6893 	 * If we backed off this far, our srtt estimate is probably bogus.
6894 	 * Clobber it so we'll take the next rtt measurement as our srtt;
6895 	 * move the current srtt into rttvar to keep the current retransmit
6896 	 * times until then.
6897 	 */
6898 	if (tp->t_rxtshift > TCP_MAXRXTSHIFT / 4) {
6899 #ifdef INET6
6900 		if ((inp->inp_vflag & INP_IPV6) != 0)
6901 			in6_losing(inp);
6902 		else
6903 #endif
6904 			in_losing(inp);
6905 		tp->t_rttvar += tp->t_srtt;
6906 		tp->t_srtt = 0;
6907 	}
6908 	sack_filter_clear(&rack->r_ctl.rack_sf, tp->snd_una);
6909 	tp->snd_recover = tp->snd_max;
6910 	tp->t_flags |= TF_ACKNOW;
6911 	tp->t_rtttime = 0;
6912 	rack_cong_signal(tp, CC_RTO, tp->snd_una, __LINE__);
6913 out:
6914 	return (retval);
6915 }
6916 
6917 static int
6918 rack_process_timers(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cts, uint8_t hpts_calling, uint8_t *doing_tlp)
6919 {
6920 	int32_t ret = 0;
6921 	int32_t timers = (rack->r_ctl.rc_hpts_flags & PACE_TMR_MASK);
6922 
6923 	if ((tp->t_state >= TCPS_FIN_WAIT_1) &&
6924 	    (tp->t_flags & TF_GPUTINPROG)) {
6925 		/*
6926 		 * We have a goodput in progress
6927 		 * and we have entered a late state.
6928 		 * Do we have enough data in the sb
6929 		 * to handle the GPUT request?
6930 		 */
6931 		uint32_t bytes;
6932 
6933 		bytes = tp->gput_ack - tp->gput_seq;
6934 		if (SEQ_GT(tp->gput_seq, tp->snd_una))
6935 			bytes += tp->gput_seq - tp->snd_una;
6936 		if (bytes > sbavail(&tptosocket(tp)->so_snd)) {
6937 			/*
6938 			 * There are not enough bytes in the socket
6939 			 * buffer that have been sent to cover this
6940 			 * measurement. Cancel it.
6941 			 */
6942 			rack_log_pacing_delay_calc(rack, (tp->gput_ack - tp->gput_seq) /*flex2*/,
6943 						   rack->r_ctl.rc_gp_srtt /*flex1*/,
6944 						   tp->gput_seq,
6945 						   0, 0, 18, __LINE__, NULL, 0);
6946 			tp->t_flags &= ~TF_GPUTINPROG;
6947 		}
6948 	}
6949 	if (timers == 0) {
6950 		return (0);
6951 	}
6952 	if (tp->t_state == TCPS_LISTEN) {
6953 		/* no timers on listen sockets */
6954 		if (rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT)
6955 			return (0);
6956 		return (1);
6957 	}
6958 	if ((timers & PACE_TMR_RACK) &&
6959 	    rack->rc_on_min_to) {
6960 		/*
6961 		 * For the rack timer when we
6962 		 * are on a min-timeout (which means rrr_conf = 3)
6963 		 * we don't want to check the timer. It may
6964 		 * be going off for a pace and thats ok we
6965 		 * want to send the retransmit (if its ready).
6966 		 *
6967 		 * If its on a normal rack timer (non-min) then
6968 		 * we will check if its expired.
6969 		 */
6970 		goto skip_time_check;
6971 	}
6972 	if (TSTMP_LT(cts, rack->r_ctl.rc_timer_exp)) {
6973 		uint32_t left;
6974 
6975 		if (rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT) {
6976 			ret = -1;
6977 			rack_log_to_processing(rack, cts, ret, 0);
6978 			return (0);
6979 		}
6980 		if (hpts_calling == 0) {
6981 			/*
6982 			 * A user send or queued mbuf (sack) has called us? We
6983 			 * return 0 and let the pacing guards
6984 			 * deal with it if they should or
6985 			 * should not cause a send.
6986 			 */
6987 			ret = -2;
6988 			rack_log_to_processing(rack, cts, ret, 0);
6989 			return (0);
6990 		}
6991 		/*
6992 		 * Ok our timer went off early and we are not paced false
6993 		 * alarm, go back to sleep.
6994 		 */
6995 		ret = -3;
6996 		left = rack->r_ctl.rc_timer_exp - cts;
6997 		tcp_hpts_insert(tptoinpcb(tp), HPTS_MS_TO_SLOTS(left));
6998 		rack_log_to_processing(rack, cts, ret, left);
6999 		return (1);
7000 	}
7001 skip_time_check:
7002 	rack->rc_tmr_stopped = 0;
7003 	rack->r_ctl.rc_hpts_flags &= ~PACE_TMR_MASK;
7004 	if (timers & PACE_TMR_DELACK) {
7005 		ret = rack_timeout_delack(tp, rack, cts);
7006 	} else if (timers & PACE_TMR_RACK) {
7007 		rack->r_ctl.rc_tlp_rxt_last_time = cts;
7008 		rack->r_fast_output = 0;
7009 		ret = rack_timeout_rack(tp, rack, cts);
7010 	} else if (timers & PACE_TMR_TLP) {
7011 		rack->r_ctl.rc_tlp_rxt_last_time = cts;
7012 		ret = rack_timeout_tlp(tp, rack, cts, doing_tlp);
7013 	} else if (timers & PACE_TMR_RXT) {
7014 		rack->r_ctl.rc_tlp_rxt_last_time = cts;
7015 		rack->r_fast_output = 0;
7016 		ret = rack_timeout_rxt(tp, rack, cts);
7017 	} else if (timers & PACE_TMR_PERSIT) {
7018 		ret = rack_timeout_persist(tp, rack, cts);
7019 	} else if (timers & PACE_TMR_KEEP) {
7020 		ret = rack_timeout_keepalive(tp, rack, cts);
7021 	}
7022 	rack_log_to_processing(rack, cts, ret, timers);
7023 	return (ret);
7024 }
7025 
7026 static void
7027 rack_timer_cancel(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cts, int line)
7028 {
7029 	struct timeval tv;
7030 	uint32_t us_cts, flags_on_entry;
7031 	uint8_t hpts_removed = 0;
7032 
7033 	flags_on_entry = rack->r_ctl.rc_hpts_flags;
7034 	us_cts = tcp_get_usecs(&tv);
7035 	if ((rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT) &&
7036 	    ((TSTMP_GEQ(us_cts, rack->r_ctl.rc_last_output_to)) ||
7037 	     ((tp->snd_max - tp->snd_una) == 0))) {
7038 		tcp_hpts_remove(rack->rc_inp);
7039 		hpts_removed = 1;
7040 		/* If we were not delayed cancel out the flag. */
7041 		if ((tp->snd_max - tp->snd_una) == 0)
7042 			rack->r_ctl.rc_hpts_flags &= ~PACE_PKT_OUTPUT;
7043 		rack_log_to_cancel(rack, hpts_removed, line, us_cts, &tv, flags_on_entry);
7044 	}
7045 	if (rack->r_ctl.rc_hpts_flags & PACE_TMR_MASK) {
7046 		rack->rc_tmr_stopped = rack->r_ctl.rc_hpts_flags & PACE_TMR_MASK;
7047 		if (tcp_in_hpts(rack->rc_inp) &&
7048 		    ((rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT) == 0)) {
7049 			/*
7050 			 * Canceling timer's when we have no output being
7051 			 * paced. We also must remove ourselves from the
7052 			 * hpts.
7053 			 */
7054 			tcp_hpts_remove(rack->rc_inp);
7055 			hpts_removed = 1;
7056 		}
7057 		rack->r_ctl.rc_hpts_flags &= ~(PACE_TMR_MASK);
7058 	}
7059 	if (hpts_removed == 0)
7060 		rack_log_to_cancel(rack, hpts_removed, line, us_cts, &tv, flags_on_entry);
7061 }
7062 
7063 static void
7064 rack_timer_stop(struct tcpcb *tp, uint32_t timer_type)
7065 {
7066 	return;
7067 }
7068 
7069 static int
7070 rack_stopall(struct tcpcb *tp)
7071 {
7072 	struct tcp_rack *rack;
7073 	rack = (struct tcp_rack *)tp->t_fb_ptr;
7074 	rack->t_timers_stopped = 1;
7075 	return (0);
7076 }
7077 
7078 static void
7079 rack_timer_activate(struct tcpcb *tp, uint32_t timer_type, uint32_t delta)
7080 {
7081 	return;
7082 }
7083 
7084 static int
7085 rack_timer_active(struct tcpcb *tp, uint32_t timer_type)
7086 {
7087 	return (0);
7088 }
7089 
7090 static void
7091 rack_stop_all_timers(struct tcpcb *tp)
7092 {
7093 	struct tcp_rack *rack;
7094 
7095 	/*
7096 	 * Assure no timers are running.
7097 	 */
7098 	if (tcp_timer_active(tp, TT_PERSIST)) {
7099 		/* We enter in persists, set the flag appropriately */
7100 		rack = (struct tcp_rack *)tp->t_fb_ptr;
7101 		rack->rc_in_persist = 1;
7102 	}
7103 	tcp_timer_suspend(tp, TT_PERSIST);
7104 	tcp_timer_suspend(tp, TT_REXMT);
7105 	tcp_timer_suspend(tp, TT_KEEP);
7106 	tcp_timer_suspend(tp, TT_DELACK);
7107 }
7108 
7109 static void
7110 rack_update_rsm(struct tcpcb *tp, struct tcp_rack *rack,
7111     struct rack_sendmap *rsm, uint64_t ts, uint16_t add_flag)
7112 {
7113 	int32_t idx;
7114 
7115 	rsm->r_rtr_cnt++;
7116 	rack_log_retran_reason(rack, rsm, __LINE__, 0, 2);
7117 	rsm->r_dupack = 0;
7118 	if (rsm->r_rtr_cnt > RACK_NUM_OF_RETRANS) {
7119 		rsm->r_rtr_cnt = RACK_NUM_OF_RETRANS;
7120 		rsm->r_flags |= RACK_OVERMAX;
7121 	}
7122 	if ((rsm->r_rtr_cnt > 1) && ((rsm->r_flags & RACK_TLP) == 0)) {
7123 		rack->r_ctl.rc_holes_rxt += (rsm->r_end - rsm->r_start);
7124 		rsm->r_rtr_bytes += (rsm->r_end - rsm->r_start);
7125 	}
7126 	idx = rsm->r_rtr_cnt - 1;
7127 	rsm->r_tim_lastsent[idx] = ts;
7128 	/*
7129 	 * Here we don't add in the len of send, since its already
7130 	 * in snduna <->snd_max.
7131 	 */
7132 	rsm->r_fas = ctf_flight_size(rack->rc_tp,
7133 				     rack->r_ctl.rc_sacked);
7134 	if (rsm->r_flags & RACK_ACKED) {
7135 		/* Problably MTU discovery messing with us */
7136 		rsm->r_flags &= ~RACK_ACKED;
7137 		rack->r_ctl.rc_sacked -= (rsm->r_end - rsm->r_start);
7138 	}
7139 	if (rsm->r_in_tmap) {
7140 		TAILQ_REMOVE(&rack->r_ctl.rc_tmap, rsm, r_tnext);
7141 		rsm->r_in_tmap = 0;
7142 	}
7143 	TAILQ_INSERT_TAIL(&rack->r_ctl.rc_tmap, rsm, r_tnext);
7144 	rsm->r_in_tmap = 1;
7145 	/* Take off the must retransmit flag, if its on */
7146 	if (rsm->r_flags & RACK_MUST_RXT) {
7147 		if (rack->r_must_retran)
7148 			rack->r_ctl.rc_out_at_rto -= (rsm->r_end - rsm->r_start);
7149 		if (SEQ_GEQ(rsm->r_end, rack->r_ctl.rc_snd_max_at_rto)) {
7150 			/*
7151 			 * We have retransmitted all we need. Clear
7152 			 * any must retransmit flags.
7153 			 */
7154 			rack->r_must_retran = 0;
7155 			rack->r_ctl.rc_out_at_rto = 0;
7156 		}
7157 		rsm->r_flags &= ~RACK_MUST_RXT;
7158 	}
7159 	if (rsm->r_flags & RACK_SACK_PASSED) {
7160 		/* We have retransmitted due to the SACK pass */
7161 		rsm->r_flags &= ~RACK_SACK_PASSED;
7162 		rsm->r_flags |= RACK_WAS_SACKPASS;
7163 	}
7164 }
7165 
7166 static uint32_t
7167 rack_update_entry(struct tcpcb *tp, struct tcp_rack *rack,
7168     struct rack_sendmap *rsm, uint64_t ts, int32_t *lenp, uint16_t add_flag)
7169 {
7170 	/*
7171 	 * We (re-)transmitted starting at rsm->r_start for some length
7172 	 * (possibly less than r_end.
7173 	 */
7174 	struct rack_sendmap *nrsm;
7175 #ifdef INVARIANTS
7176 	struct rack_sendmap *insret;
7177 #endif
7178 	uint32_t c_end;
7179 	int32_t len;
7180 
7181 	len = *lenp;
7182 	c_end = rsm->r_start + len;
7183 	if (SEQ_GEQ(c_end, rsm->r_end)) {
7184 		/*
7185 		 * We retransmitted the whole piece or more than the whole
7186 		 * slopping into the next rsm.
7187 		 */
7188 		rack_update_rsm(tp, rack, rsm, ts, add_flag);
7189 		if (c_end == rsm->r_end) {
7190 			*lenp = 0;
7191 			return (0);
7192 		} else {
7193 			int32_t act_len;
7194 
7195 			/* Hangs over the end return whats left */
7196 			act_len = rsm->r_end - rsm->r_start;
7197 			*lenp = (len - act_len);
7198 			return (rsm->r_end);
7199 		}
7200 		/* We don't get out of this block. */
7201 	}
7202 	/*
7203 	 * Here we retransmitted less than the whole thing which means we
7204 	 * have to split this into what was transmitted and what was not.
7205 	 */
7206 	nrsm = rack_alloc_full_limit(rack);
7207 	if (nrsm == NULL) {
7208 		/*
7209 		 * We can't get memory, so lets not proceed.
7210 		 */
7211 		*lenp = 0;
7212 		return (0);
7213 	}
7214 	/*
7215 	 * So here we are going to take the original rsm and make it what we
7216 	 * retransmitted. nrsm will be the tail portion we did not
7217 	 * retransmit. For example say the chunk was 1, 11 (10 bytes). And
7218 	 * we retransmitted 5 bytes i.e. 1, 5. The original piece shrinks to
7219 	 * 1, 6 and the new piece will be 6, 11.
7220 	 */
7221 	rack_clone_rsm(rack, nrsm, rsm, c_end);
7222 	nrsm->r_dupack = 0;
7223 	rack_log_retran_reason(rack, nrsm, __LINE__, 0, 2);
7224 #ifndef INVARIANTS
7225 	(void)RB_INSERT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, nrsm);
7226 #else
7227 	insret = RB_INSERT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, nrsm);
7228 	if (insret != NULL) {
7229 		panic("Insert in rb tree of %p fails ret:%p rack:%p rsm:%p",
7230 		      nrsm, insret, rack, rsm);
7231 	}
7232 #endif
7233 	if (rsm->r_in_tmap) {
7234 		TAILQ_INSERT_AFTER(&rack->r_ctl.rc_tmap, rsm, nrsm, r_tnext);
7235 		nrsm->r_in_tmap = 1;
7236 	}
7237 	rsm->r_flags &= (~RACK_HAS_FIN);
7238 	rack_update_rsm(tp, rack, rsm, ts, add_flag);
7239 	/* Log a split of rsm into rsm and nrsm */
7240 	rack_log_map_chg(tp, rack, NULL, rsm, nrsm, MAP_SPLIT, 0, __LINE__);
7241 	*lenp = 0;
7242 	return (0);
7243 }
7244 
7245 static void
7246 rack_log_output(struct tcpcb *tp, struct tcpopt *to, int32_t len,
7247 		uint32_t seq_out, uint16_t th_flags, int32_t err, uint64_t cts,
7248 		struct rack_sendmap *hintrsm, uint16_t add_flag, struct mbuf *s_mb, uint32_t s_moff, int hw_tls)
7249 {
7250 	struct tcp_rack *rack;
7251 	struct rack_sendmap *rsm, *nrsm, fe;
7252 #ifdef INVARIANTS
7253 	struct rack_sendmap *insret;
7254 #endif
7255 	register uint32_t snd_max, snd_una;
7256 
7257 	/*
7258 	 * Add to the RACK log of packets in flight or retransmitted. If
7259 	 * there is a TS option we will use the TS echoed, if not we will
7260 	 * grab a TS.
7261 	 *
7262 	 * Retransmissions will increment the count and move the ts to its
7263 	 * proper place. Note that if options do not include TS's then we
7264 	 * won't be able to effectively use the ACK for an RTT on a retran.
7265 	 *
7266 	 * Notes about r_start and r_end. Lets consider a send starting at
7267 	 * sequence 1 for 10 bytes. In such an example the r_start would be
7268 	 * 1 (starting sequence) but the r_end would be r_start+len i.e. 11.
7269 	 * This means that r_end is actually the first sequence for the next
7270 	 * slot (11).
7271 	 *
7272 	 */
7273 	/*
7274 	 * If err is set what do we do XXXrrs? should we not add the thing?
7275 	 * -- i.e. return if err != 0 or should we pretend we sent it? --
7276 	 * i.e. proceed with add ** do this for now.
7277 	 */
7278 	INP_WLOCK_ASSERT(tptoinpcb(tp));
7279 	if (err)
7280 		/*
7281 		 * We don't log errors -- we could but snd_max does not
7282 		 * advance in this case either.
7283 		 */
7284 		return;
7285 
7286 	if (th_flags & TH_RST) {
7287 		/*
7288 		 * We don't log resets and we return immediately from
7289 		 * sending
7290 		 */
7291 		return;
7292 	}
7293 	rack = (struct tcp_rack *)tp->t_fb_ptr;
7294 	snd_una = tp->snd_una;
7295 	snd_max = tp->snd_max;
7296 	if (th_flags & (TH_SYN | TH_FIN)) {
7297 		/*
7298 		 * The call to rack_log_output is made before bumping
7299 		 * snd_max. This means we can record one extra byte on a SYN
7300 		 * or FIN if seq_out is adding more on and a FIN is present
7301 		 * (and we are not resending).
7302 		 */
7303 		if ((th_flags & TH_SYN) && (seq_out == tp->iss))
7304 			len++;
7305 		if (th_flags & TH_FIN)
7306 			len++;
7307 		if (SEQ_LT(snd_max, tp->snd_nxt)) {
7308 			/*
7309 			 * The add/update as not been done for the FIN/SYN
7310 			 * yet.
7311 			 */
7312 			snd_max = tp->snd_nxt;
7313 		}
7314 	}
7315 	if (SEQ_LEQ((seq_out + len), snd_una)) {
7316 		/* Are sending an old segment to induce an ack (keep-alive)? */
7317 		return;
7318 	}
7319 	if (SEQ_LT(seq_out, snd_una)) {
7320 		/* huh? should we panic? */
7321 		uint32_t end;
7322 
7323 		end = seq_out + len;
7324 		seq_out = snd_una;
7325 		if (SEQ_GEQ(end, seq_out))
7326 			len = end - seq_out;
7327 		else
7328 			len = 0;
7329 	}
7330 	if (len == 0) {
7331 		/* We don't log zero window probes */
7332 		return;
7333 	}
7334 	if (IN_FASTRECOVERY(tp->t_flags)) {
7335 		rack->r_ctl.rc_prr_out += len;
7336 	}
7337 	/* First question is it a retransmission or new? */
7338 	if (seq_out == snd_max) {
7339 		/* Its new */
7340 again:
7341 		rsm = rack_alloc(rack);
7342 		if (rsm == NULL) {
7343 			/*
7344 			 * Hmm out of memory and the tcb got destroyed while
7345 			 * we tried to wait.
7346 			 */
7347 			return;
7348 		}
7349 		if (th_flags & TH_FIN) {
7350 			rsm->r_flags = RACK_HAS_FIN|add_flag;
7351 		} else {
7352 			rsm->r_flags = add_flag;
7353 		}
7354 		if (hw_tls)
7355 			rsm->r_hw_tls = 1;
7356 		rsm->r_tim_lastsent[0] = cts;
7357 		rsm->r_rtr_cnt = 1;
7358 		rsm->r_rtr_bytes = 0;
7359 		if (th_flags & TH_SYN) {
7360 			/* The data space is one beyond snd_una */
7361 			rsm->r_flags |= RACK_HAS_SYN;
7362 		}
7363 		rsm->r_start = seq_out;
7364 		rsm->r_end = rsm->r_start + len;
7365 		rsm->r_dupack = 0;
7366 		/*
7367 		 * save off the mbuf location that
7368 		 * sndmbuf_noadv returned (which is
7369 		 * where we started copying from)..
7370 		 */
7371 		rsm->m = s_mb;
7372 		rsm->soff = s_moff;
7373 		/*
7374 		 * Here we do add in the len of send, since its not yet
7375 		 * reflected in in snduna <->snd_max
7376 		 */
7377 		rsm->r_fas = (ctf_flight_size(rack->rc_tp,
7378 					      rack->r_ctl.rc_sacked) +
7379 			      (rsm->r_end - rsm->r_start));
7380 		/* rsm->m will be NULL if RACK_HAS_SYN or RACK_HAS_FIN is set */
7381 		if (rsm->m) {
7382 			if (rsm->m->m_len <= rsm->soff) {
7383 				/*
7384 				 * XXXrrs Question, will this happen?
7385 				 *
7386 				 * If sbsndptr is set at the correct place
7387 				 * then s_moff should always be somewhere
7388 				 * within rsm->m. But if the sbsndptr was
7389 				 * off then that won't be true. If it occurs
7390 				 * we need to walkout to the correct location.
7391 				 */
7392 				struct mbuf *lm;
7393 
7394 				lm = rsm->m;
7395 				while (lm->m_len <= rsm->soff) {
7396 					rsm->soff -= lm->m_len;
7397 					lm = lm->m_next;
7398 					KASSERT(lm != NULL, ("%s rack:%p lm goes null orig_off:%u origmb:%p rsm->soff:%u",
7399 							     __func__, rack, s_moff, s_mb, rsm->soff));
7400 				}
7401 				rsm->m = lm;
7402 			}
7403 			rsm->orig_m_len = rsm->m->m_len;
7404 		} else
7405 			rsm->orig_m_len = 0;
7406 		rack_log_retran_reason(rack, rsm, __LINE__, 0, 2);
7407 		/* Log a new rsm */
7408 		rack_log_map_chg(tp, rack, NULL, rsm, NULL, MAP_NEW, 0, __LINE__);
7409 #ifndef INVARIANTS
7410 		(void)RB_INSERT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm);
7411 #else
7412 		insret = RB_INSERT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm);
7413 		if (insret != NULL) {
7414 			panic("Insert in rb tree of %p fails ret:%p rack:%p rsm:%p",
7415 			      nrsm, insret, rack, rsm);
7416 		}
7417 #endif
7418 		TAILQ_INSERT_TAIL(&rack->r_ctl.rc_tmap, rsm, r_tnext);
7419 		rsm->r_in_tmap = 1;
7420 		/*
7421 		 * Special case detection, is there just a single
7422 		 * packet outstanding when we are not in recovery?
7423 		 *
7424 		 * If this is true mark it so.
7425 		 */
7426 		if ((IN_FASTRECOVERY(tp->t_flags) == 0) &&
7427 		    (ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked) == ctf_fixed_maxseg(tp))) {
7428 			struct rack_sendmap *prsm;
7429 
7430 			prsm = RB_PREV(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm);
7431 			if (prsm)
7432 				prsm->r_one_out_nr = 1;
7433 		}
7434 		return;
7435 	}
7436 	/*
7437 	 * If we reach here its a retransmission and we need to find it.
7438 	 */
7439 	memset(&fe, 0, sizeof(fe));
7440 more:
7441 	if (hintrsm && (hintrsm->r_start == seq_out)) {
7442 		rsm = hintrsm;
7443 		hintrsm = NULL;
7444 	} else {
7445 		/* No hints sorry */
7446 		rsm = NULL;
7447 	}
7448 	if ((rsm) && (rsm->r_start == seq_out)) {
7449 		seq_out = rack_update_entry(tp, rack, rsm, cts, &len, add_flag);
7450 		if (len == 0) {
7451 			return;
7452 		} else {
7453 			goto more;
7454 		}
7455 	}
7456 	/* Ok it was not the last pointer go through it the hard way. */
7457 refind:
7458 	fe.r_start = seq_out;
7459 	rsm = RB_FIND(rack_rb_tree_head, &rack->r_ctl.rc_mtree, &fe);
7460 	if (rsm) {
7461 		if (rsm->r_start == seq_out) {
7462 			seq_out = rack_update_entry(tp, rack, rsm, cts, &len, add_flag);
7463 			if (len == 0) {
7464 				return;
7465 			} else {
7466 				goto refind;
7467 			}
7468 		}
7469 		if (SEQ_GEQ(seq_out, rsm->r_start) && SEQ_LT(seq_out, rsm->r_end)) {
7470 			/* Transmitted within this piece */
7471 			/*
7472 			 * Ok we must split off the front and then let the
7473 			 * update do the rest
7474 			 */
7475 			nrsm = rack_alloc_full_limit(rack);
7476 			if (nrsm == NULL) {
7477 				rack_update_rsm(tp, rack, rsm, cts, add_flag);
7478 				return;
7479 			}
7480 			/*
7481 			 * copy rsm to nrsm and then trim the front of rsm
7482 			 * to not include this part.
7483 			 */
7484 			rack_clone_rsm(rack, nrsm, rsm, seq_out);
7485 			rack_log_map_chg(tp, rack, NULL, rsm, nrsm, MAP_SPLIT, 0, __LINE__);
7486 #ifndef INVARIANTS
7487 			(void)RB_INSERT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, nrsm);
7488 #else
7489 			insret = RB_INSERT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, nrsm);
7490 			if (insret != NULL) {
7491 				panic("Insert in rb tree of %p fails ret:%p rack:%p rsm:%p",
7492 				      nrsm, insret, rack, rsm);
7493 			}
7494 #endif
7495 			if (rsm->r_in_tmap) {
7496 				TAILQ_INSERT_AFTER(&rack->r_ctl.rc_tmap, rsm, nrsm, r_tnext);
7497 				nrsm->r_in_tmap = 1;
7498 			}
7499 			rsm->r_flags &= (~RACK_HAS_FIN);
7500 			seq_out = rack_update_entry(tp, rack, nrsm, cts, &len, add_flag);
7501 			if (len == 0) {
7502 				return;
7503 			} else if (len > 0)
7504 				goto refind;
7505 		}
7506 	}
7507 	/*
7508 	 * Hmm not found in map did they retransmit both old and on into the
7509 	 * new?
7510 	 */
7511 	if (seq_out == tp->snd_max) {
7512 		goto again;
7513 	} else if (SEQ_LT(seq_out, tp->snd_max)) {
7514 #ifdef INVARIANTS
7515 		printf("seq_out:%u len:%d snd_una:%u snd_max:%u -- but rsm not found?\n",
7516 		       seq_out, len, tp->snd_una, tp->snd_max);
7517 		printf("Starting Dump of all rack entries\n");
7518 		RB_FOREACH(rsm, rack_rb_tree_head, &rack->r_ctl.rc_mtree) {
7519 			printf("rsm:%p start:%u end:%u\n",
7520 			       rsm, rsm->r_start, rsm->r_end);
7521 		}
7522 		printf("Dump complete\n");
7523 		panic("seq_out not found rack:%p tp:%p",
7524 		      rack, tp);
7525 #endif
7526 	} else {
7527 #ifdef INVARIANTS
7528 		/*
7529 		 * Hmm beyond sndmax? (only if we are using the new rtt-pack
7530 		 * flag)
7531 		 */
7532 		panic("seq_out:%u(%d) is beyond snd_max:%u tp:%p",
7533 		      seq_out, len, tp->snd_max, tp);
7534 #endif
7535 	}
7536 }
7537 
7538 /*
7539  * Record one of the RTT updates from an ack into
7540  * our sample structure.
7541  */
7542 
7543 static void
7544 tcp_rack_xmit_timer(struct tcp_rack *rack, int32_t rtt, uint32_t len, uint32_t us_rtt,
7545 		    int confidence, struct rack_sendmap *rsm, uint16_t rtrcnt)
7546 {
7547 	if ((rack->r_ctl.rack_rs.rs_flags & RACK_RTT_EMPTY) ||
7548 	    (rack->r_ctl.rack_rs.rs_rtt_lowest > rtt)) {
7549 		rack->r_ctl.rack_rs.rs_rtt_lowest = rtt;
7550 	}
7551 	if ((rack->r_ctl.rack_rs.rs_flags & RACK_RTT_EMPTY) ||
7552 	    (rack->r_ctl.rack_rs.rs_rtt_highest < rtt)) {
7553 		rack->r_ctl.rack_rs.rs_rtt_highest = rtt;
7554 	}
7555 	if (rack->rc_tp->t_flags & TF_GPUTINPROG) {
7556 	    if (us_rtt < rack->r_ctl.rc_gp_lowrtt)
7557 		rack->r_ctl.rc_gp_lowrtt = us_rtt;
7558 	    if (rack->rc_tp->snd_wnd > rack->r_ctl.rc_gp_high_rwnd)
7559 		    rack->r_ctl.rc_gp_high_rwnd = rack->rc_tp->snd_wnd;
7560 	}
7561 	if ((confidence == 1) &&
7562 	    ((rsm == NULL) ||
7563 	     (rsm->r_just_ret) ||
7564 	     (rsm->r_one_out_nr &&
7565 	      len < (ctf_fixed_maxseg(rack->rc_tp) * 2)))) {
7566 		/*
7567 		 * If the rsm had a just return
7568 		 * hit it then we can't trust the
7569 		 * rtt measurement for buffer deterimination
7570 		 * Note that a confidence of 2, indicates
7571 		 * SACK'd which overrides the r_just_ret or
7572 		 * the r_one_out_nr. If it was a CUM-ACK and
7573 		 * we had only two outstanding, but get an
7574 		 * ack for only 1. Then that also lowers our
7575 		 * confidence.
7576 		 */
7577 		confidence = 0;
7578 	}
7579 	if ((rack->r_ctl.rack_rs.rs_flags & RACK_RTT_EMPTY) ||
7580 	    (rack->r_ctl.rack_rs.rs_us_rtt > us_rtt)) {
7581 		if (rack->r_ctl.rack_rs.confidence == 0) {
7582 			/*
7583 			 * We take anything with no current confidence
7584 			 * saved.
7585 			 */
7586 			rack->r_ctl.rack_rs.rs_us_rtt = us_rtt;
7587 			rack->r_ctl.rack_rs.confidence = confidence;
7588 			rack->r_ctl.rack_rs.rs_us_rtrcnt = rtrcnt;
7589 		} else if (confidence || rack->r_ctl.rack_rs.confidence) {
7590 			/*
7591 			 * Once we have a confident number,
7592 			 * we can update it with a smaller
7593 			 * value since this confident number
7594 			 * may include the DSACK time until
7595 			 * the next segment (the second one) arrived.
7596 			 */
7597 			rack->r_ctl.rack_rs.rs_us_rtt = us_rtt;
7598 			rack->r_ctl.rack_rs.confidence = confidence;
7599 			rack->r_ctl.rack_rs.rs_us_rtrcnt = rtrcnt;
7600 		}
7601 	}
7602 	rack_log_rtt_upd(rack->rc_tp, rack, us_rtt, len, rsm, confidence);
7603 	rack->r_ctl.rack_rs.rs_flags = RACK_RTT_VALID;
7604 	rack->r_ctl.rack_rs.rs_rtt_tot += rtt;
7605 	rack->r_ctl.rack_rs.rs_rtt_cnt++;
7606 }
7607 
7608 /*
7609  * Collect new round-trip time estimate
7610  * and update averages and current timeout.
7611  */
7612 static void
7613 tcp_rack_xmit_timer_commit(struct tcp_rack *rack, struct tcpcb *tp)
7614 {
7615 	int32_t delta;
7616 	int32_t rtt;
7617 
7618 	if (rack->r_ctl.rack_rs.rs_flags & RACK_RTT_EMPTY)
7619 		/* No valid sample */
7620 		return;
7621 	if (rack->r_ctl.rc_rate_sample_method == USE_RTT_LOW) {
7622 		/* We are to use the lowest RTT seen in a single ack */
7623 		rtt = rack->r_ctl.rack_rs.rs_rtt_lowest;
7624 	} else if (rack->r_ctl.rc_rate_sample_method == USE_RTT_HIGH) {
7625 		/* We are to use the highest RTT seen in a single ack */
7626 		rtt = rack->r_ctl.rack_rs.rs_rtt_highest;
7627 	} else if (rack->r_ctl.rc_rate_sample_method == USE_RTT_AVG) {
7628 		/* We are to use the average RTT seen in a single ack */
7629 		rtt = (int32_t)(rack->r_ctl.rack_rs.rs_rtt_tot /
7630 				(uint64_t)rack->r_ctl.rack_rs.rs_rtt_cnt);
7631 	} else {
7632 #ifdef INVARIANTS
7633 		panic("Unknown rtt variant %d", rack->r_ctl.rc_rate_sample_method);
7634 #endif
7635 		return;
7636 	}
7637 	if (rtt == 0)
7638 		rtt = 1;
7639 	if (rack->rc_gp_rtt_set == 0) {
7640 		/*
7641 		 * With no RTT we have to accept
7642 		 * even one we are not confident of.
7643 		 */
7644 		rack->r_ctl.rc_gp_srtt = rack->r_ctl.rack_rs.rs_us_rtt;
7645 		rack->rc_gp_rtt_set = 1;
7646 	} else if (rack->r_ctl.rack_rs.confidence) {
7647 		/* update the running gp srtt */
7648 		rack->r_ctl.rc_gp_srtt -= (rack->r_ctl.rc_gp_srtt/8);
7649 		rack->r_ctl.rc_gp_srtt += rack->r_ctl.rack_rs.rs_us_rtt / 8;
7650 	}
7651 	if (rack->r_ctl.rack_rs.confidence) {
7652 		/*
7653 		 * record the low and high for highly buffered path computation,
7654 		 * we only do this if we are confident (not a retransmission).
7655 		 */
7656 		if (rack->r_ctl.rc_highest_us_rtt < rack->r_ctl.rack_rs.rs_us_rtt) {
7657 			rack->r_ctl.rc_highest_us_rtt = rack->r_ctl.rack_rs.rs_us_rtt;
7658 		}
7659 		if (rack->rc_highly_buffered == 0) {
7660 			/*
7661 			 * Currently once we declare a path has
7662 			 * highly buffered there is no going
7663 			 * back, which may be a problem...
7664 			 */
7665 			if ((rack->r_ctl.rc_highest_us_rtt / rack->r_ctl.rc_lowest_us_rtt) > rack_hbp_thresh) {
7666 				rack_log_rtt_shrinks(rack, rack->r_ctl.rack_rs.rs_us_rtt,
7667 						     rack->r_ctl.rc_highest_us_rtt,
7668 						     rack->r_ctl.rc_lowest_us_rtt,
7669 						     RACK_RTTS_SEEHBP);
7670 				rack->rc_highly_buffered = 1;
7671 			}
7672 		}
7673 	}
7674 	if ((rack->r_ctl.rack_rs.confidence) ||
7675 	    (rack->r_ctl.rack_rs.rs_us_rtrcnt == 1)) {
7676 		/*
7677 		 * If we are highly confident of it <or> it was
7678 		 * never retransmitted we accept it as the last us_rtt.
7679 		 */
7680 		rack->r_ctl.rc_last_us_rtt = rack->r_ctl.rack_rs.rs_us_rtt;
7681 		/* The lowest rtt can be set if its was not retransmited */
7682 		if (rack->r_ctl.rc_lowest_us_rtt > rack->r_ctl.rack_rs.rs_us_rtt) {
7683 			rack->r_ctl.rc_lowest_us_rtt = rack->r_ctl.rack_rs.rs_us_rtt;
7684 			if (rack->r_ctl.rc_lowest_us_rtt == 0)
7685 				rack->r_ctl.rc_lowest_us_rtt = 1;
7686 		}
7687 	}
7688 	rack = (struct tcp_rack *)tp->t_fb_ptr;
7689 	if (tp->t_srtt != 0) {
7690 		/*
7691 		 * We keep a simple srtt in microseconds, like our rtt
7692 		 * measurement. We don't need to do any tricks with shifting
7693 		 * etc. Instead we just add in 1/8th of the new measurement
7694 		 * and subtract out 1/8 of the old srtt. We do the same with
7695 		 * the variance after finding the absolute value of the
7696 		 * difference between this sample and the current srtt.
7697 		 */
7698 		delta = tp->t_srtt - rtt;
7699 		/* Take off 1/8th of the current sRTT */
7700 		tp->t_srtt -= (tp->t_srtt >> 3);
7701 		/* Add in 1/8th of the new RTT just measured */
7702 		tp->t_srtt += (rtt >> 3);
7703 		if (tp->t_srtt <= 0)
7704 			tp->t_srtt = 1;
7705 		/* Now lets make the absolute value of the variance */
7706 		if (delta < 0)
7707 			delta = -delta;
7708 		/* Subtract out 1/8th */
7709 		tp->t_rttvar -= (tp->t_rttvar >> 3);
7710 		/* Add in 1/8th of the new variance we just saw */
7711 		tp->t_rttvar += (delta >> 3);
7712 		if (tp->t_rttvar <= 0)
7713 			tp->t_rttvar = 1;
7714 	} else {
7715 		/*
7716 		 * No rtt measurement yet - use the unsmoothed rtt. Set the
7717 		 * variance to half the rtt (so our first retransmit happens
7718 		 * at 3*rtt).
7719 		 */
7720 		tp->t_srtt = rtt;
7721 		tp->t_rttvar = rtt >> 1;
7722 	}
7723 	rack->rc_srtt_measure_made = 1;
7724 	KMOD_TCPSTAT_INC(tcps_rttupdated);
7725 	tp->t_rttupdated++;
7726 #ifdef STATS
7727 	if (rack_stats_gets_ms_rtt == 0) {
7728 		/* Send in the microsecond rtt used for rxt timeout purposes */
7729 		stats_voi_update_abs_u32(tp->t_stats, VOI_TCP_RTT, imax(0, rtt));
7730 	} else if (rack_stats_gets_ms_rtt == 1) {
7731 		/* Send in the millisecond rtt used for rxt timeout purposes */
7732 		int32_t ms_rtt;
7733 
7734 		/* Round up */
7735 		ms_rtt = (rtt + HPTS_USEC_IN_MSEC - 1) / HPTS_USEC_IN_MSEC;
7736 		stats_voi_update_abs_u32(tp->t_stats, VOI_TCP_RTT, imax(0, ms_rtt));
7737 	} else if (rack_stats_gets_ms_rtt == 2) {
7738 		/* Send in the millisecond rtt has close to the path RTT as we can get  */
7739 		int32_t ms_rtt;
7740 
7741 		/* Round up */
7742 		ms_rtt = (rack->r_ctl.rack_rs.rs_us_rtt + HPTS_USEC_IN_MSEC - 1) / HPTS_USEC_IN_MSEC;
7743 		stats_voi_update_abs_u32(tp->t_stats, VOI_TCP_RTT, imax(0, ms_rtt));
7744 	}  else {
7745 		/* Send in the microsecond rtt has close to the path RTT as we can get  */
7746 		stats_voi_update_abs_u32(tp->t_stats, VOI_TCP_RTT, imax(0, rack->r_ctl.rack_rs.rs_us_rtt));
7747 	}
7748 
7749 #endif
7750 	/*
7751 	 * the retransmit should happen at rtt + 4 * rttvar. Because of the
7752 	 * way we do the smoothing, srtt and rttvar will each average +1/2
7753 	 * tick of bias.  When we compute the retransmit timer, we want 1/2
7754 	 * tick of rounding and 1 extra tick because of +-1/2 tick
7755 	 * uncertainty in the firing of the timer.  The bias will give us
7756 	 * exactly the 1.5 tick we need.  But, because the bias is
7757 	 * statistical, we have to test that we don't drop below the minimum
7758 	 * feasible timer (which is 2 ticks).
7759 	 */
7760 	tp->t_rxtshift = 0;
7761 	RACK_TCPT_RANGESET(tp->t_rxtcur, RACK_REXMTVAL(tp),
7762 		      max(rack_rto_min, rtt + 2), rack_rto_max, rack->r_ctl.timer_slop);
7763 	rack_log_rtt_sample(rack, rtt);
7764 	tp->t_softerror = 0;
7765 }
7766 
7767 
7768 static void
7769 rack_apply_updated_usrtt(struct tcp_rack *rack, uint32_t us_rtt, uint32_t us_cts)
7770 {
7771 	/*
7772 	 * Apply to filter the inbound us-rtt at us_cts.
7773 	 */
7774 	uint32_t old_rtt;
7775 
7776 	old_rtt = get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt);
7777 	apply_filter_min_small(&rack->r_ctl.rc_gp_min_rtt,
7778 			       us_rtt, us_cts);
7779 	if (old_rtt > us_rtt) {
7780 		/* We just hit a new lower rtt time */
7781 		rack_log_rtt_shrinks(rack,  us_cts,  old_rtt,
7782 				     __LINE__, RACK_RTTS_NEWRTT);
7783 		/*
7784 		 * Only count it if its lower than what we saw within our
7785 		 * calculated range.
7786 		 */
7787 		if ((old_rtt - us_rtt) > rack_min_rtt_movement) {
7788 			if (rack_probertt_lower_within &&
7789 			    rack->rc_gp_dyn_mul &&
7790 			    (rack->use_fixed_rate == 0) &&
7791 			    (rack->rc_always_pace)) {
7792 				/*
7793 				 * We are seeing a new lower rtt very close
7794 				 * to the time that we would have entered probe-rtt.
7795 				 * This is probably due to the fact that a peer flow
7796 				 * has entered probe-rtt. Lets go in now too.
7797 				 */
7798 				uint32_t val;
7799 
7800 				val = rack_probertt_lower_within * rack_time_between_probertt;
7801 				val /= 100;
7802 				if ((rack->in_probe_rtt == 0)  &&
7803 				    ((us_cts - rack->r_ctl.rc_lower_rtt_us_cts) >= (rack_time_between_probertt - val)))	{
7804 					rack_enter_probertt(rack, us_cts);
7805 				}
7806 			}
7807 			rack->r_ctl.rc_lower_rtt_us_cts = us_cts;
7808 		}
7809 	}
7810 }
7811 
7812 static int
7813 rack_update_rtt(struct tcpcb *tp, struct tcp_rack *rack,
7814     struct rack_sendmap *rsm, struct tcpopt *to, uint32_t cts, int32_t ack_type, tcp_seq th_ack)
7815 {
7816 	uint32_t us_rtt;
7817 	int32_t i, all;
7818 	uint32_t t, len_acked;
7819 
7820 	if ((rsm->r_flags & RACK_ACKED) ||
7821 	    (rsm->r_flags & RACK_WAS_ACKED))
7822 		/* Already done */
7823 		return (0);
7824 	if (rsm->r_no_rtt_allowed) {
7825 		/* Not allowed */
7826 		return (0);
7827 	}
7828 	if (ack_type == CUM_ACKED) {
7829 		if (SEQ_GT(th_ack, rsm->r_end)) {
7830 			len_acked = rsm->r_end - rsm->r_start;
7831 			all = 1;
7832 		} else {
7833 			len_acked = th_ack - rsm->r_start;
7834 			all = 0;
7835 		}
7836 	} else {
7837 		len_acked = rsm->r_end - rsm->r_start;
7838 		all = 0;
7839 	}
7840 	if (rsm->r_rtr_cnt == 1) {
7841 
7842 		t = cts - (uint32_t)rsm->r_tim_lastsent[(rsm->r_rtr_cnt - 1)];
7843 		if ((int)t <= 0)
7844 			t = 1;
7845 		if (!tp->t_rttlow || tp->t_rttlow > t)
7846 			tp->t_rttlow = t;
7847 		if (!rack->r_ctl.rc_rack_min_rtt ||
7848 		    SEQ_LT(t, rack->r_ctl.rc_rack_min_rtt)) {
7849 			rack->r_ctl.rc_rack_min_rtt = t;
7850 			if (rack->r_ctl.rc_rack_min_rtt == 0) {
7851 				rack->r_ctl.rc_rack_min_rtt = 1;
7852 			}
7853 		}
7854 		if (TSTMP_GT(tcp_tv_to_usectick(&rack->r_ctl.act_rcv_time), rsm->r_tim_lastsent[(rsm->r_rtr_cnt-1)]))
7855 			us_rtt = tcp_tv_to_usectick(&rack->r_ctl.act_rcv_time) - (uint32_t)rsm->r_tim_lastsent[(rsm->r_rtr_cnt-1)];
7856 		else
7857 			us_rtt = tcp_get_usecs(NULL) - (uint32_t)rsm->r_tim_lastsent[(rsm->r_rtr_cnt-1)];
7858 		if (us_rtt == 0)
7859 			us_rtt = 1;
7860 		if (CC_ALGO(tp)->rttsample != NULL) {
7861 			/* Kick the RTT to the CC */
7862 			CC_ALGO(tp)->rttsample(tp->ccv, us_rtt, 1, rsm->r_fas);
7863 		}
7864 		rack_apply_updated_usrtt(rack, us_rtt, tcp_tv_to_usectick(&rack->r_ctl.act_rcv_time));
7865 		if (ack_type == SACKED) {
7866 			rack_log_rtt_sample_calc(rack, t, (uint32_t)rsm->r_tim_lastsent[(rsm->r_rtr_cnt - 1)], cts, 1);
7867 			tcp_rack_xmit_timer(rack, t + 1, len_acked, us_rtt, 2 , rsm, rsm->r_rtr_cnt);
7868 		} else {
7869 			/*
7870 			 * We need to setup what our confidence
7871 			 * is in this ack.
7872 			 *
7873 			 * If the rsm was app limited and it is
7874 			 * less than a mss in length (the end
7875 			 * of the send) then we have a gap. If we
7876 			 * were app limited but say we were sending
7877 			 * multiple MSS's then we are more confident
7878 			 * int it.
7879 			 *
7880 			 * When we are not app-limited then we see if
7881 			 * the rsm is being included in the current
7882 			 * measurement, we tell this by the app_limited_needs_set
7883 			 * flag.
7884 			 *
7885 			 * Note that being cwnd blocked is not applimited
7886 			 * as well as the pacing delay between packets which
7887 			 * are sending only 1 or 2 MSS's also will show up
7888 			 * in the RTT. We probably need to examine this algorithm
7889 			 * a bit more and enhance it to account for the delay
7890 			 * between rsm's. We could do that by saving off the
7891 			 * pacing delay of each rsm (in an rsm) and then
7892 			 * factoring that in somehow though for now I am
7893 			 * not sure how :)
7894 			 */
7895 			int calc_conf = 0;
7896 
7897 			if (rsm->r_flags & RACK_APP_LIMITED) {
7898 				if (all && (len_acked <= ctf_fixed_maxseg(tp)))
7899 					calc_conf = 0;
7900 				else
7901 					calc_conf = 1;
7902 			} else if (rack->app_limited_needs_set == 0) {
7903 				calc_conf = 1;
7904 			} else {
7905 				calc_conf = 0;
7906 			}
7907 			rack_log_rtt_sample_calc(rack, t, (uint32_t)rsm->r_tim_lastsent[(rsm->r_rtr_cnt - 1)], cts, 2);
7908 			tcp_rack_xmit_timer(rack, t + 1, len_acked, us_rtt,
7909 					    calc_conf, rsm, rsm->r_rtr_cnt);
7910 		}
7911 		if ((rsm->r_flags & RACK_TLP) &&
7912 		    (!IN_FASTRECOVERY(tp->t_flags))) {
7913 			/* Segment was a TLP and our retrans matched */
7914 			if (rack->r_ctl.rc_tlp_cwnd_reduce) {
7915 				rack_cong_signal(tp, CC_NDUPACK, tp->snd_una, __LINE__);
7916 			}
7917 		}
7918 		if (SEQ_LT(rack->r_ctl.rc_rack_tmit_time, (uint32_t)rsm->r_tim_lastsent[(rsm->r_rtr_cnt - 1)])) {
7919 			/* New more recent rack_tmit_time */
7920 			rack->r_ctl.rc_rack_tmit_time = (uint32_t)rsm->r_tim_lastsent[(rsm->r_rtr_cnt - 1)];
7921 			rack->rc_rack_rtt = t;
7922 		}
7923 		return (1);
7924 	}
7925 	/*
7926 	 * We clear the soft/rxtshift since we got an ack.
7927 	 * There is no assurance we will call the commit() function
7928 	 * so we need to clear these to avoid incorrect handling.
7929 	 */
7930 	tp->t_rxtshift = 0;
7931 	RACK_TCPT_RANGESET(tp->t_rxtcur, RACK_REXMTVAL(tp),
7932 		      rack_rto_min, rack_rto_max, rack->r_ctl.timer_slop);
7933 	tp->t_softerror = 0;
7934 	if (to && (to->to_flags & TOF_TS) &&
7935 	    (ack_type == CUM_ACKED) &&
7936 	    (to->to_tsecr) &&
7937 	    ((rsm->r_flags & RACK_OVERMAX) == 0)) {
7938 		/*
7939 		 * Now which timestamp does it match? In this block the ACK
7940 		 * must be coming from a previous transmission.
7941 		 */
7942 		for (i = 0; i < rsm->r_rtr_cnt; i++) {
7943 			if (rack_ts_to_msec(rsm->r_tim_lastsent[i]) == to->to_tsecr) {
7944 				t = cts - (uint32_t)rsm->r_tim_lastsent[i];
7945 				if ((int)t <= 0)
7946 					t = 1;
7947 				if (CC_ALGO(tp)->rttsample != NULL) {
7948 					/*
7949 					 * Kick the RTT to the CC, here
7950 					 * we lie a bit in that we know the
7951 					 * retransmission is correct even though
7952 					 * we retransmitted. This is because
7953 					 * we match the timestamps.
7954 					 */
7955 					if (TSTMP_GT(tcp_tv_to_usectick(&rack->r_ctl.act_rcv_time), rsm->r_tim_lastsent[i]))
7956 						us_rtt = tcp_tv_to_usectick(&rack->r_ctl.act_rcv_time) - (uint32_t)rsm->r_tim_lastsent[i];
7957 					else
7958 						us_rtt = tcp_get_usecs(NULL) - (uint32_t)rsm->r_tim_lastsent[i];
7959 					CC_ALGO(tp)->rttsample(tp->ccv, us_rtt, 1, rsm->r_fas);
7960 				}
7961 				if ((i + 1) < rsm->r_rtr_cnt) {
7962 					/*
7963 					 * The peer ack'd from our previous
7964 					 * transmission. We have a spurious
7965 					 * retransmission and thus we dont
7966 					 * want to update our rack_rtt.
7967 					 *
7968 					 * Hmm should there be a CC revert here?
7969 					 *
7970 					 */
7971 					return (0);
7972 				}
7973 				if (!tp->t_rttlow || tp->t_rttlow > t)
7974 					tp->t_rttlow = t;
7975 				if (!rack->r_ctl.rc_rack_min_rtt || SEQ_LT(t, rack->r_ctl.rc_rack_min_rtt)) {
7976 					rack->r_ctl.rc_rack_min_rtt = t;
7977 					if (rack->r_ctl.rc_rack_min_rtt == 0) {
7978 						rack->r_ctl.rc_rack_min_rtt = 1;
7979 					}
7980 				}
7981 				if (SEQ_LT(rack->r_ctl.rc_rack_tmit_time,
7982 					   (uint32_t)rsm->r_tim_lastsent[(rsm->r_rtr_cnt - 1)])) {
7983 					/* New more recent rack_tmit_time */
7984 					rack->r_ctl.rc_rack_tmit_time = (uint32_t)rsm->r_tim_lastsent[(rsm->r_rtr_cnt - 1)];
7985 					rack->rc_rack_rtt = t;
7986 				}
7987 				rack_log_rtt_sample_calc(rack, t, (uint32_t)rsm->r_tim_lastsent[i], cts, 3);
7988 				tcp_rack_xmit_timer(rack, t + 1, len_acked, t, 0, rsm,
7989 						    rsm->r_rtr_cnt);
7990 				return (1);
7991 			}
7992 		}
7993 		goto ts_not_found;
7994 	} else {
7995 		/*
7996 		 * Ok its a SACK block that we retransmitted. or a windows
7997 		 * machine without timestamps. We can tell nothing from the
7998 		 * time-stamp since its not there or the time the peer last
7999 		 * recieved a segment that moved forward its cum-ack point.
8000 		 */
8001 ts_not_found:
8002 		i = rsm->r_rtr_cnt - 1;
8003 		t = cts - (uint32_t)rsm->r_tim_lastsent[i];
8004 		if ((int)t <= 0)
8005 			t = 1;
8006 		if (rack->r_ctl.rc_rack_min_rtt && SEQ_LT(t, rack->r_ctl.rc_rack_min_rtt)) {
8007 			/*
8008 			 * We retransmitted and the ack came back in less
8009 			 * than the smallest rtt we have observed. We most
8010 			 * likely did an improper retransmit as outlined in
8011 			 * 6.2 Step 2 point 2 in the rack-draft so we
8012 			 * don't want to update our rack_rtt. We in
8013 			 * theory (in future) might want to think about reverting our
8014 			 * cwnd state but we won't for now.
8015 			 */
8016 			return (0);
8017 		} else if (rack->r_ctl.rc_rack_min_rtt) {
8018 			/*
8019 			 * We retransmitted it and the retransmit did the
8020 			 * job.
8021 			 */
8022 			if (!rack->r_ctl.rc_rack_min_rtt ||
8023 			    SEQ_LT(t, rack->r_ctl.rc_rack_min_rtt)) {
8024 				rack->r_ctl.rc_rack_min_rtt = t;
8025 				if (rack->r_ctl.rc_rack_min_rtt == 0) {
8026 					rack->r_ctl.rc_rack_min_rtt = 1;
8027 				}
8028 			}
8029 			if (SEQ_LT(rack->r_ctl.rc_rack_tmit_time, (uint32_t)rsm->r_tim_lastsent[i])) {
8030 				/* New more recent rack_tmit_time */
8031 				rack->r_ctl.rc_rack_tmit_time = (uint32_t)rsm->r_tim_lastsent[i];
8032 				rack->rc_rack_rtt = t;
8033 			}
8034 			return (1);
8035 		}
8036 	}
8037 	return (0);
8038 }
8039 
8040 /*
8041  * Mark the SACK_PASSED flag on all entries prior to rsm send wise.
8042  */
8043 static void
8044 rack_log_sack_passed(struct tcpcb *tp,
8045     struct tcp_rack *rack, struct rack_sendmap *rsm)
8046 {
8047 	struct rack_sendmap *nrsm;
8048 
8049 	nrsm = rsm;
8050 	TAILQ_FOREACH_REVERSE_FROM(nrsm, &rack->r_ctl.rc_tmap,
8051 	    rack_head, r_tnext) {
8052 		if (nrsm == rsm) {
8053 			/* Skip orginal segment he is acked */
8054 			continue;
8055 		}
8056 		if (nrsm->r_flags & RACK_ACKED) {
8057 			/*
8058 			 * Skip ack'd segments, though we
8059 			 * should not see these, since tmap
8060 			 * should not have ack'd segments.
8061 			 */
8062 			continue;
8063 		}
8064 		if (nrsm->r_flags & RACK_RWND_COLLAPSED) {
8065 			/*
8066 			 * If the peer dropped the rwnd on
8067 			 * these then we don't worry about them.
8068 			 */
8069 			continue;
8070 		}
8071 		if (nrsm->r_flags & RACK_SACK_PASSED) {
8072 			/*
8073 			 * We found one that is already marked
8074 			 * passed, we have been here before and
8075 			 * so all others below this are marked.
8076 			 */
8077 			break;
8078 		}
8079 		nrsm->r_flags |= RACK_SACK_PASSED;
8080 		nrsm->r_flags &= ~RACK_WAS_SACKPASS;
8081 	}
8082 }
8083 
8084 static void
8085 rack_need_set_test(struct tcpcb *tp,
8086 		   struct tcp_rack *rack,
8087 		   struct rack_sendmap *rsm,
8088 		   tcp_seq th_ack,
8089 		   int line,
8090 		   int use_which)
8091 {
8092 
8093 	if ((tp->t_flags & TF_GPUTINPROG) &&
8094 	    SEQ_GEQ(rsm->r_end, tp->gput_seq)) {
8095 		/*
8096 		 * We were app limited, and this ack
8097 		 * butts up or goes beyond the point where we want
8098 		 * to start our next measurement. We need
8099 		 * to record the new gput_ts as here and
8100 		 * possibly update the start sequence.
8101 		 */
8102 		uint32_t seq, ts;
8103 
8104 		if (rsm->r_rtr_cnt > 1) {
8105 			/*
8106 			 * This is a retransmit, can we
8107 			 * really make any assessment at this
8108 			 * point?  We are not really sure of
8109 			 * the timestamp, is it this or the
8110 			 * previous transmission?
8111 			 *
8112 			 * Lets wait for something better that
8113 			 * is not retransmitted.
8114 			 */
8115 			return;
8116 		}
8117 		seq = tp->gput_seq;
8118 		ts = tp->gput_ts;
8119 		rack->app_limited_needs_set = 0;
8120 		tp->gput_ts = tcp_tv_to_usectick(&rack->r_ctl.act_rcv_time);
8121 		/* Do we start at a new end? */
8122 		if ((use_which == RACK_USE_BEG) &&
8123 		    SEQ_GEQ(rsm->r_start, tp->gput_seq)) {
8124 			/*
8125 			 * When we get an ACK that just eats
8126 			 * up some of the rsm, we set RACK_USE_BEG
8127 			 * since whats at r_start (i.e. th_ack)
8128 			 * is left unacked and thats where the
8129 			 * measurement not starts.
8130 			 */
8131 			tp->gput_seq = rsm->r_start;
8132 			rack->r_ctl.rc_gp_output_ts = rsm->r_tim_lastsent[(rsm->r_rtr_cnt-1)];
8133 		}
8134 		if ((use_which == RACK_USE_END) &&
8135 		    SEQ_GEQ(rsm->r_end, tp->gput_seq)) {
8136 			    /*
8137 			     * We use the end when the cumack
8138 			     * is moving forward and completely
8139 			     * deleting the rsm passed so basically
8140 			     * r_end holds th_ack.
8141 			     *
8142 			     * For SACK's we also want to use the end
8143 			     * since this piece just got sacked and
8144 			     * we want to target anything after that
8145 			     * in our measurement.
8146 			     */
8147 			    tp->gput_seq = rsm->r_end;
8148 			    rack->r_ctl.rc_gp_output_ts = rsm->r_tim_lastsent[(rsm->r_rtr_cnt-1)];
8149 		}
8150 		if (use_which == RACK_USE_END_OR_THACK) {
8151 			/*
8152 			 * special case for ack moving forward,
8153 			 * not a sack, we need to move all the
8154 			 * way up to where this ack cum-ack moves
8155 			 * to.
8156 			 */
8157 			if (SEQ_GT(th_ack, rsm->r_end))
8158 				tp->gput_seq = th_ack;
8159 			else
8160 				tp->gput_seq = rsm->r_end;
8161 			rack->r_ctl.rc_gp_output_ts = rsm->r_tim_lastsent[(rsm->r_rtr_cnt-1)];
8162 		}
8163 		if (SEQ_GT(tp->gput_seq, tp->gput_ack)) {
8164 			/*
8165 			 * We moved beyond this guy's range, re-calculate
8166 			 * the new end point.
8167 			 */
8168 			if (rack->rc_gp_filled == 0) {
8169 				tp->gput_ack = tp->gput_seq + max(rc_init_window(rack), (MIN_GP_WIN * ctf_fixed_maxseg(tp)));
8170 			} else {
8171 				tp->gput_ack = tp->gput_seq + rack_get_measure_window(tp, rack);
8172 			}
8173 		}
8174 		/*
8175 		 * We are moving the goal post, we may be able to clear the
8176 		 * measure_saw_probe_rtt flag.
8177 		 */
8178 		if ((rack->in_probe_rtt == 0) &&
8179 		    (rack->measure_saw_probe_rtt) &&
8180 		    (SEQ_GEQ(tp->gput_seq, rack->r_ctl.rc_probertt_sndmax_atexit)))
8181 			rack->measure_saw_probe_rtt = 0;
8182 		rack_log_pacing_delay_calc(rack, ts, tp->gput_ts,
8183 					   seq, tp->gput_seq, 0, 5, line, NULL, 0);
8184 		if (rack->rc_gp_filled &&
8185 		    ((tp->gput_ack - tp->gput_seq) <
8186 		     max(rc_init_window(rack), (MIN_GP_WIN *
8187 						ctf_fixed_maxseg(tp))))) {
8188 			uint32_t ideal_amount;
8189 
8190 			ideal_amount = rack_get_measure_window(tp, rack);
8191 			if (ideal_amount > sbavail(&tptosocket(tp)->so_snd)) {
8192 				/*
8193 				 * There is no sense of continuing this measurement
8194 				 * because its too small to gain us anything we
8195 				 * trust. Skip it and that way we can start a new
8196 				 * measurement quicker.
8197 				 */
8198 				tp->t_flags &= ~TF_GPUTINPROG;
8199 				rack_log_pacing_delay_calc(rack, tp->gput_ack, tp->gput_seq,
8200 							   0, 0, 0, 6, __LINE__, NULL, 0);
8201 			} else {
8202 				/*
8203 				 * Reset the window further out.
8204 				 */
8205 				tp->gput_ack = tp->gput_seq + ideal_amount;
8206 			}
8207 		}
8208 	}
8209 }
8210 
8211 static inline int
8212 is_rsm_inside_declared_tlp_block(struct tcp_rack *rack, struct rack_sendmap *rsm)
8213 {
8214 	if (SEQ_LT(rsm->r_end, rack->r_ctl.last_tlp_acked_start)) {
8215 		/* Behind our TLP definition or right at */
8216 		return (0);
8217 	}
8218 	if (SEQ_GT(rsm->r_start, rack->r_ctl.last_tlp_acked_end)) {
8219 		/* The start is beyond or right at our end of TLP definition */
8220 		return (0);
8221 	}
8222 	/* It has to be a sub-part of the original TLP recorded */
8223 	return (1);
8224 }
8225 
8226 
8227 static uint32_t
8228 rack_proc_sack_blk(struct tcpcb *tp, struct tcp_rack *rack, struct sackblk *sack,
8229 		   struct tcpopt *to, struct rack_sendmap **prsm, uint32_t cts, int *moved_two)
8230 {
8231 	uint32_t start, end, changed = 0;
8232 	struct rack_sendmap stack_map;
8233 	struct rack_sendmap *rsm, *nrsm, fe, *prev, *next;
8234 #ifdef INVARIANTS
8235 	struct rack_sendmap *insret;
8236 #endif
8237 	int32_t used_ref = 1;
8238 	int moved = 0;
8239 
8240 	start = sack->start;
8241 	end = sack->end;
8242 	rsm = *prsm;
8243 	memset(&fe, 0, sizeof(fe));
8244 do_rest_ofb:
8245 	if ((rsm == NULL) ||
8246 	    (SEQ_LT(end, rsm->r_start)) ||
8247 	    (SEQ_GEQ(start, rsm->r_end)) ||
8248 	    (SEQ_LT(start, rsm->r_start))) {
8249 		/*
8250 		 * We are not in the right spot,
8251 		 * find the correct spot in the tree.
8252 		 */
8253 		used_ref = 0;
8254 		fe.r_start = start;
8255 		rsm = RB_FIND(rack_rb_tree_head, &rack->r_ctl.rc_mtree, &fe);
8256 		moved++;
8257 	}
8258 	if (rsm == NULL) {
8259 		/* TSNH */
8260 		goto out;
8261 	}
8262 	/* Ok we have an ACK for some piece of this rsm */
8263 	if (rsm->r_start != start) {
8264 		if ((rsm->r_flags & RACK_ACKED) == 0) {
8265 			/*
8266 			 * Before any splitting or hookery is
8267 			 * done is it a TLP of interest i.e. rxt?
8268 			 */
8269 			if ((rsm->r_flags & RACK_TLP) &&
8270 			    (rsm->r_rtr_cnt > 1)) {
8271 				/*
8272 				 * We are splitting a rxt TLP, check
8273 				 * if we need to save off the start/end
8274 				 */
8275 				if (rack->rc_last_tlp_acked_set &&
8276 				    (is_rsm_inside_declared_tlp_block(rack, rsm))) {
8277 					/*
8278 					 * We already turned this on since we are inside
8279 					 * the previous one was a partially sack now we
8280 					 * are getting another one (maybe all of it).
8281 					 *
8282 					 */
8283 					rack_log_dsack_event(rack, 10, __LINE__, rsm->r_start, rsm->r_end);
8284 					/*
8285 					 * Lets make sure we have all of it though.
8286 					 */
8287 					if (SEQ_LT(rsm->r_start, rack->r_ctl.last_tlp_acked_start)) {
8288 						rack->r_ctl.last_tlp_acked_start = rsm->r_start;
8289 						rack_log_dsack_event(rack, 11, __LINE__, rack->r_ctl.last_tlp_acked_start,
8290 								     rack->r_ctl.last_tlp_acked_end);
8291 					}
8292 					if (SEQ_GT(rsm->r_end, rack->r_ctl.last_tlp_acked_end)) {
8293 						rack->r_ctl.last_tlp_acked_end = rsm->r_end;
8294 						rack_log_dsack_event(rack, 11, __LINE__, rack->r_ctl.last_tlp_acked_start,
8295 								     rack->r_ctl.last_tlp_acked_end);
8296 					}
8297 				} else {
8298 					rack->r_ctl.last_tlp_acked_start = rsm->r_start;
8299 					rack->r_ctl.last_tlp_acked_end = rsm->r_end;
8300 					rack->rc_last_tlp_past_cumack = 0;
8301 					rack->rc_last_tlp_acked_set = 1;
8302 					rack_log_dsack_event(rack, 8, __LINE__, rsm->r_start, rsm->r_end);
8303 				}
8304 			}
8305 			/**
8306 			 * Need to split this in two pieces the before and after,
8307 			 * the before remains in the map, the after must be
8308 			 * added. In other words we have:
8309 			 * rsm        |--------------|
8310 			 * sackblk        |------->
8311 			 * rsm will become
8312 			 *     rsm    |---|
8313 			 * and nrsm will be  the sacked piece
8314 			 *     nrsm       |----------|
8315 			 *
8316 			 * But before we start down that path lets
8317 			 * see if the sack spans over on top of
8318 			 * the next guy and it is already sacked.
8319 			 *
8320 			 */
8321 			next = RB_NEXT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm);
8322 			if (next && (next->r_flags & RACK_ACKED) &&
8323 			    SEQ_GEQ(end, next->r_start)) {
8324 				/**
8325 				 * So the next one is already acked, and
8326 				 * we can thus by hookery use our stack_map
8327 				 * to reflect the piece being sacked and
8328 				 * then adjust the two tree entries moving
8329 				 * the start and ends around. So we start like:
8330 				 *  rsm     |------------|             (not-acked)
8331 				 *  next                 |-----------| (acked)
8332 				 *  sackblk        |-------->
8333 				 *  We want to end like so:
8334 				 *  rsm     |------|                   (not-acked)
8335 				 *  next           |-----------------| (acked)
8336 				 *  nrsm           |-----|
8337 				 * Where nrsm is a temporary stack piece we
8338 				 * use to update all the gizmos.
8339 				 */
8340 				/* Copy up our fudge block */
8341 				nrsm = &stack_map;
8342 				memcpy(nrsm, rsm, sizeof(struct rack_sendmap));
8343 				/* Now adjust our tree blocks */
8344 				rsm->r_end = start;
8345 				next->r_start = start;
8346 				/* Now we must adjust back where next->m is */
8347 				rack_setup_offset_for_rsm(rsm, next);
8348 
8349 				/* We don't need to adjust rsm, it did not change */
8350 				/* Clear out the dup ack count of the remainder */
8351 				rsm->r_dupack = 0;
8352 				rsm->r_just_ret = 0;
8353 				rack_log_retran_reason(rack, rsm, __LINE__, 0, 2);
8354 				/* Now lets make sure our fudge block is right */
8355 				nrsm->r_start = start;
8356 				/* Now lets update all the stats and such */
8357 				rack_update_rtt(tp, rack, nrsm, to, cts, SACKED, 0);
8358 				if (rack->app_limited_needs_set)
8359 					rack_need_set_test(tp, rack, nrsm, tp->snd_una, __LINE__, RACK_USE_END);
8360 				changed += (nrsm->r_end - nrsm->r_start);
8361 				rack->r_ctl.rc_sacked += (nrsm->r_end - nrsm->r_start);
8362 				if (nrsm->r_flags & RACK_SACK_PASSED) {
8363 					rack->r_ctl.rc_reorder_ts = cts;
8364 				}
8365 				/*
8366 				 * Now we want to go up from rsm (the
8367 				 * one left un-acked) to the next one
8368 				 * in the tmap. We do this so when
8369 				 * we walk backwards we include marking
8370 				 * sack-passed on rsm (The one passed in
8371 				 * is skipped since it is generally called
8372 				 * on something sacked before removing it
8373 				 * from the tmap).
8374 				 */
8375 				if (rsm->r_in_tmap) {
8376 					nrsm = TAILQ_NEXT(rsm, r_tnext);
8377 					/*
8378 					 * Now that we have the next
8379 					 * one walk backwards from there.
8380 					 */
8381 					if (nrsm && nrsm->r_in_tmap)
8382 						rack_log_sack_passed(tp, rack, nrsm);
8383 				}
8384 				/* Now are we done? */
8385 				if (SEQ_LT(end, next->r_end) ||
8386 				    (end == next->r_end)) {
8387 					/* Done with block */
8388 					goto out;
8389 				}
8390 				rack_log_map_chg(tp, rack, &stack_map, rsm, next, MAP_SACK_M1, end, __LINE__);
8391 				counter_u64_add(rack_sack_used_next_merge, 1);
8392 				/* Postion for the next block */
8393 				start = next->r_end;
8394 				rsm = RB_NEXT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, next);
8395 				if (rsm == NULL)
8396 					goto out;
8397 			} else {
8398 				/**
8399 				 * We can't use any hookery here, so we
8400 				 * need to split the map. We enter like
8401 				 * so:
8402 				 *  rsm      |--------|
8403 				 *  sackblk       |----->
8404 				 * We will add the new block nrsm and
8405 				 * that will be the new portion, and then
8406 				 * fall through after reseting rsm. So we
8407 				 * split and look like this:
8408 				 *  rsm      |----|
8409 				 *  sackblk       |----->
8410 				 *  nrsm          |---|
8411 				 * We then fall through reseting
8412 				 * rsm to nrsm, so the next block
8413 				 * picks it up.
8414 				 */
8415 				nrsm = rack_alloc_limit(rack, RACK_LIMIT_TYPE_SPLIT);
8416 				if (nrsm == NULL) {
8417 					/*
8418 					 * failed XXXrrs what can we do but loose the sack
8419 					 * info?
8420 					 */
8421 					goto out;
8422 				}
8423 				counter_u64_add(rack_sack_splits, 1);
8424 				rack_clone_rsm(rack, nrsm, rsm, start);
8425 				rsm->r_just_ret = 0;
8426 #ifndef INVARIANTS
8427 				(void)RB_INSERT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, nrsm);
8428 #else
8429 				insret = RB_INSERT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, nrsm);
8430 				if (insret != NULL) {
8431 					panic("Insert in rb tree of %p fails ret:%p rack:%p rsm:%p",
8432 					      nrsm, insret, rack, rsm);
8433 				}
8434 #endif
8435 				if (rsm->r_in_tmap) {
8436 					TAILQ_INSERT_AFTER(&rack->r_ctl.rc_tmap, rsm, nrsm, r_tnext);
8437 					nrsm->r_in_tmap = 1;
8438 				}
8439 				rack_log_map_chg(tp, rack, NULL, rsm, nrsm, MAP_SACK_M2, end, __LINE__);
8440 				rsm->r_flags &= (~RACK_HAS_FIN);
8441 				/* Position us to point to the new nrsm that starts the sack blk */
8442 				rsm = nrsm;
8443 			}
8444 		} else {
8445 			/* Already sacked this piece */
8446 			counter_u64_add(rack_sack_skipped_acked, 1);
8447 			moved++;
8448 			if (end == rsm->r_end) {
8449 				/* Done with block */
8450 				rsm = RB_NEXT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm);
8451 				goto out;
8452 			} else if (SEQ_LT(end, rsm->r_end)) {
8453 				/* A partial sack to a already sacked block */
8454 				moved++;
8455 				rsm = RB_NEXT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm);
8456 				goto out;
8457 			} else {
8458 				/*
8459 				 * The end goes beyond this guy
8460 				 * reposition the start to the
8461 				 * next block.
8462 				 */
8463 				start = rsm->r_end;
8464 				rsm = RB_NEXT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm);
8465 				if (rsm == NULL)
8466 					goto out;
8467 			}
8468 		}
8469 	}
8470 	if (SEQ_GEQ(end, rsm->r_end)) {
8471 		/**
8472 		 * The end of this block is either beyond this guy or right
8473 		 * at this guy. I.e.:
8474 		 *  rsm ---                 |-----|
8475 		 *  end                     |-----|
8476 		 *  <or>
8477 		 *  end                     |---------|
8478 		 */
8479 		if ((rsm->r_flags & RACK_ACKED) == 0) {
8480 			/*
8481 			 * Is it a TLP of interest?
8482 			 */
8483 			if ((rsm->r_flags & RACK_TLP) &&
8484 			    (rsm->r_rtr_cnt > 1)) {
8485 				/*
8486 				 * We are splitting a rxt TLP, check
8487 				 * if we need to save off the start/end
8488 				 */
8489 				if (rack->rc_last_tlp_acked_set &&
8490 				    (is_rsm_inside_declared_tlp_block(rack, rsm))) {
8491 					/*
8492 					 * We already turned this on since we are inside
8493 					 * the previous one was a partially sack now we
8494 					 * are getting another one (maybe all of it).
8495 					 */
8496 					rack_log_dsack_event(rack, 10, __LINE__, rsm->r_start, rsm->r_end);
8497 					/*
8498 					 * Lets make sure we have all of it though.
8499 					 */
8500 					if (SEQ_LT(rsm->r_start, rack->r_ctl.last_tlp_acked_start)) {
8501 						rack->r_ctl.last_tlp_acked_start = rsm->r_start;
8502 						rack_log_dsack_event(rack, 11, __LINE__, rack->r_ctl.last_tlp_acked_start,
8503 								     rack->r_ctl.last_tlp_acked_end);
8504 					}
8505 					if (SEQ_GT(rsm->r_end, rack->r_ctl.last_tlp_acked_end)) {
8506 						rack->r_ctl.last_tlp_acked_end = rsm->r_end;
8507 						rack_log_dsack_event(rack, 11, __LINE__, rack->r_ctl.last_tlp_acked_start,
8508 								     rack->r_ctl.last_tlp_acked_end);
8509 					}
8510 				} else {
8511 					rack->r_ctl.last_tlp_acked_start = rsm->r_start;
8512 					rack->r_ctl.last_tlp_acked_end = rsm->r_end;
8513 					rack->rc_last_tlp_past_cumack = 0;
8514 					rack->rc_last_tlp_acked_set = 1;
8515 					rack_log_dsack_event(rack, 8, __LINE__, rsm->r_start, rsm->r_end);
8516 				}
8517 			}
8518 			rack_update_rtt(tp, rack, rsm, to, cts, SACKED, 0);
8519 			changed += (rsm->r_end - rsm->r_start);
8520 			rack->r_ctl.rc_sacked += (rsm->r_end - rsm->r_start);
8521 			if (rsm->r_in_tmap) /* should be true */
8522 				rack_log_sack_passed(tp, rack, rsm);
8523 			/* Is Reordering occuring? */
8524 			if (rsm->r_flags & RACK_SACK_PASSED) {
8525 				rsm->r_flags &= ~RACK_SACK_PASSED;
8526 				rack->r_ctl.rc_reorder_ts = cts;
8527 			}
8528 			if (rack->app_limited_needs_set)
8529 				rack_need_set_test(tp, rack, rsm, tp->snd_una, __LINE__, RACK_USE_END);
8530 			rsm->r_ack_arrival = rack_to_usec_ts(&rack->r_ctl.act_rcv_time);
8531 			rsm->r_flags |= RACK_ACKED;
8532 			if (rsm->r_in_tmap) {
8533 				TAILQ_REMOVE(&rack->r_ctl.rc_tmap, rsm, r_tnext);
8534 				rsm->r_in_tmap = 0;
8535 			}
8536 			rack_log_map_chg(tp, rack, NULL, rsm, NULL, MAP_SACK_M3, end, __LINE__);
8537 		} else {
8538 			counter_u64_add(rack_sack_skipped_acked, 1);
8539 			moved++;
8540 		}
8541 		if (end == rsm->r_end) {
8542 			/* This block only - done, setup for next */
8543 			goto out;
8544 		}
8545 		/*
8546 		 * There is more not coverend by this rsm move on
8547 		 * to the next block in the RB tree.
8548 		 */
8549 		nrsm = RB_NEXT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm);
8550 		start = rsm->r_end;
8551 		rsm = nrsm;
8552 		if (rsm == NULL)
8553 			goto out;
8554 		goto do_rest_ofb;
8555 	}
8556 	/**
8557 	 * The end of this sack block is smaller than
8558 	 * our rsm i.e.:
8559 	 *  rsm ---                 |-----|
8560 	 *  end                     |--|
8561 	 */
8562 	if ((rsm->r_flags & RACK_ACKED) == 0) {
8563 		/*
8564 		 * Is it a TLP of interest?
8565 		 */
8566 		if ((rsm->r_flags & RACK_TLP) &&
8567 		    (rsm->r_rtr_cnt > 1)) {
8568 			/*
8569 			 * We are splitting a rxt TLP, check
8570 			 * if we need to save off the start/end
8571 			 */
8572 			if (rack->rc_last_tlp_acked_set &&
8573 			    (is_rsm_inside_declared_tlp_block(rack, rsm))) {
8574 				/*
8575 				 * We already turned this on since we are inside
8576 				 * the previous one was a partially sack now we
8577 				 * are getting another one (maybe all of it).
8578 				 */
8579 				rack_log_dsack_event(rack, 10, __LINE__, rsm->r_start, rsm->r_end);
8580 				/*
8581 				 * Lets make sure we have all of it though.
8582 				 */
8583 				if (SEQ_LT(rsm->r_start, rack->r_ctl.last_tlp_acked_start)) {
8584 					rack->r_ctl.last_tlp_acked_start = rsm->r_start;
8585 					rack_log_dsack_event(rack, 11, __LINE__, rack->r_ctl.last_tlp_acked_start,
8586 							     rack->r_ctl.last_tlp_acked_end);
8587 				}
8588 				if (SEQ_GT(rsm->r_end, rack->r_ctl.last_tlp_acked_end)) {
8589 					rack->r_ctl.last_tlp_acked_end = rsm->r_end;
8590 					rack_log_dsack_event(rack, 11, __LINE__, rack->r_ctl.last_tlp_acked_start,
8591 							     rack->r_ctl.last_tlp_acked_end);
8592 				}
8593 			} else {
8594 				rack->r_ctl.last_tlp_acked_start = rsm->r_start;
8595 				rack->r_ctl.last_tlp_acked_end = rsm->r_end;
8596 				rack->rc_last_tlp_past_cumack = 0;
8597 				rack->rc_last_tlp_acked_set = 1;
8598 				rack_log_dsack_event(rack, 8, __LINE__, rsm->r_start, rsm->r_end);
8599 			}
8600 		}
8601 		prev = RB_PREV(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm);
8602 		if (prev &&
8603 		    (prev->r_flags & RACK_ACKED)) {
8604 			/**
8605 			 * Goal, we want the right remainder of rsm to shrink
8606 			 * in place and span from (rsm->r_start = end) to rsm->r_end.
8607 			 * We want to expand prev to go all the way
8608 			 * to prev->r_end <- end.
8609 			 * so in the tree we have before:
8610 			 *   prev     |--------|         (acked)
8611 			 *   rsm               |-------| (non-acked)
8612 			 *   sackblk           |-|
8613 			 * We churn it so we end up with
8614 			 *   prev     |----------|       (acked)
8615 			 *   rsm                 |-----| (non-acked)
8616 			 *   nrsm              |-| (temporary)
8617 			 *
8618 			 * Note if either prev/rsm is a TLP we don't
8619 			 * do this.
8620 			 */
8621 			nrsm = &stack_map;
8622 			memcpy(nrsm, rsm, sizeof(struct rack_sendmap));
8623 			prev->r_end = end;
8624 			rsm->r_start = end;
8625 			/* Now adjust nrsm (stack copy) to be
8626 			 * the one that is the small
8627 			 * piece that was "sacked".
8628 			 */
8629 			nrsm->r_end = end;
8630 			rsm->r_dupack = 0;
8631 			rack_log_retran_reason(rack, rsm, __LINE__, 0, 2);
8632 			/*
8633 			 * Now that the rsm has had its start moved forward
8634 			 * lets go ahead and get its new place in the world.
8635 			 */
8636 			rack_setup_offset_for_rsm(prev, rsm);
8637 			/*
8638 			 * Now nrsm is our new little piece
8639 			 * that is acked (which was merged
8640 			 * to prev). Update the rtt and changed
8641 			 * based on that. Also check for reordering.
8642 			 */
8643 			rack_update_rtt(tp, rack, nrsm, to, cts, SACKED, 0);
8644 			if (rack->app_limited_needs_set)
8645 				rack_need_set_test(tp, rack, nrsm, tp->snd_una, __LINE__, RACK_USE_END);
8646 			changed += (nrsm->r_end - nrsm->r_start);
8647 			rack->r_ctl.rc_sacked += (nrsm->r_end - nrsm->r_start);
8648 			if (nrsm->r_flags & RACK_SACK_PASSED) {
8649 				rack->r_ctl.rc_reorder_ts = cts;
8650 			}
8651 			rack_log_map_chg(tp, rack, prev, &stack_map, rsm, MAP_SACK_M4, end, __LINE__);
8652 			rsm = prev;
8653 			counter_u64_add(rack_sack_used_prev_merge, 1);
8654 		} else {
8655 			/**
8656 			 * This is the case where our previous
8657 			 * block is not acked either, so we must
8658 			 * split the block in two.
8659 			 */
8660 			nrsm = rack_alloc_limit(rack, RACK_LIMIT_TYPE_SPLIT);
8661 			if (nrsm == NULL) {
8662 				/* failed rrs what can we do but loose the sack info? */
8663 				goto out;
8664 			}
8665 			if ((rsm->r_flags & RACK_TLP) &&
8666 			    (rsm->r_rtr_cnt > 1)) {
8667 				/*
8668 				 * We are splitting a rxt TLP, check
8669 				 * if we need to save off the start/end
8670 				 */
8671 				if (rack->rc_last_tlp_acked_set &&
8672 				    (is_rsm_inside_declared_tlp_block(rack, rsm))) {
8673 					    /*
8674 					     * We already turned this on since this block is inside
8675 					     * the previous one was a partially sack now we
8676 					     * are getting another one (maybe all of it).
8677 					     */
8678 					    rack_log_dsack_event(rack, 10, __LINE__, rsm->r_start, rsm->r_end);
8679 					    /*
8680 					     * Lets make sure we have all of it though.
8681 					     */
8682 					    if (SEQ_LT(rsm->r_start, rack->r_ctl.last_tlp_acked_start)) {
8683 						    rack->r_ctl.last_tlp_acked_start = rsm->r_start;
8684 						    rack_log_dsack_event(rack, 11, __LINE__, rack->r_ctl.last_tlp_acked_start,
8685 									 rack->r_ctl.last_tlp_acked_end);
8686 					    }
8687 					    if (SEQ_GT(rsm->r_end, rack->r_ctl.last_tlp_acked_end)) {
8688 						    rack->r_ctl.last_tlp_acked_end = rsm->r_end;
8689 						    rack_log_dsack_event(rack, 11, __LINE__, rack->r_ctl.last_tlp_acked_start,
8690 									 rack->r_ctl.last_tlp_acked_end);
8691 					    }
8692 				    } else {
8693 					    rack->r_ctl.last_tlp_acked_start = rsm->r_start;
8694 					    rack->r_ctl.last_tlp_acked_end = rsm->r_end;
8695 					    rack->rc_last_tlp_acked_set = 1;
8696 					    rack->rc_last_tlp_past_cumack = 0;
8697 					    rack_log_dsack_event(rack, 8, __LINE__, rsm->r_start, rsm->r_end);
8698 				    }
8699 			}
8700 			/**
8701 			 * In this case nrsm becomes
8702 			 * nrsm->r_start = end;
8703 			 * nrsm->r_end = rsm->r_end;
8704 			 * which is un-acked.
8705 			 * <and>
8706 			 * rsm->r_end = nrsm->r_start;
8707 			 * i.e. the remaining un-acked
8708 			 * piece is left on the left
8709 			 * hand side.
8710 			 *
8711 			 * So we start like this
8712 			 * rsm      |----------| (not acked)
8713 			 * sackblk  |---|
8714 			 * build it so we have
8715 			 * rsm      |---|         (acked)
8716 			 * nrsm         |------|  (not acked)
8717 			 */
8718 			counter_u64_add(rack_sack_splits, 1);
8719 			rack_clone_rsm(rack, nrsm, rsm, end);
8720 			rsm->r_flags &= (~RACK_HAS_FIN);
8721 			rsm->r_just_ret = 0;
8722 #ifndef INVARIANTS
8723 			(void)RB_INSERT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, nrsm);
8724 #else
8725 			insret = RB_INSERT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, nrsm);
8726 			if (insret != NULL) {
8727 				panic("Insert in rb tree of %p fails ret:%p rack:%p rsm:%p",
8728 				      nrsm, insret, rack, rsm);
8729 			}
8730 #endif
8731 			if (rsm->r_in_tmap) {
8732 				TAILQ_INSERT_AFTER(&rack->r_ctl.rc_tmap, rsm, nrsm, r_tnext);
8733 				nrsm->r_in_tmap = 1;
8734 			}
8735 			nrsm->r_dupack = 0;
8736 			rack_log_retran_reason(rack, nrsm, __LINE__, 0, 2);
8737 			rack_update_rtt(tp, rack, rsm, to, cts, SACKED, 0);
8738 			changed += (rsm->r_end - rsm->r_start);
8739 			rack->r_ctl.rc_sacked += (rsm->r_end - rsm->r_start);
8740 			if (rsm->r_in_tmap) /* should be true */
8741 				rack_log_sack_passed(tp, rack, rsm);
8742 			/* Is Reordering occuring? */
8743 			if (rsm->r_flags & RACK_SACK_PASSED) {
8744 				rsm->r_flags &= ~RACK_SACK_PASSED;
8745 				rack->r_ctl.rc_reorder_ts = cts;
8746 			}
8747 			if (rack->app_limited_needs_set)
8748 				rack_need_set_test(tp, rack, rsm, tp->snd_una, __LINE__, RACK_USE_END);
8749 			rsm->r_ack_arrival = rack_to_usec_ts(&rack->r_ctl.act_rcv_time);
8750 			rsm->r_flags |= RACK_ACKED;
8751 			rack_log_map_chg(tp, rack, NULL, rsm, nrsm, MAP_SACK_M5, end, __LINE__);
8752 			if (rsm->r_in_tmap) {
8753 				TAILQ_REMOVE(&rack->r_ctl.rc_tmap, rsm, r_tnext);
8754 				rsm->r_in_tmap = 0;
8755 			}
8756 		}
8757 	} else if (start != end){
8758 		/*
8759 		 * The block was already acked.
8760 		 */
8761 		counter_u64_add(rack_sack_skipped_acked, 1);
8762 		moved++;
8763 	}
8764 out:
8765 	if (rsm &&
8766 	    ((rsm->r_flags & RACK_TLP) == 0) &&
8767 	    (rsm->r_flags & RACK_ACKED)) {
8768 		/*
8769 		 * Now can we merge where we worked
8770 		 * with either the previous or
8771 		 * next block?
8772 		 */
8773 		next = RB_NEXT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm);
8774 		while (next) {
8775 			if (next->r_flags & RACK_TLP)
8776 				break;
8777 			if (next->r_flags & RACK_ACKED) {
8778 			/* yep this and next can be merged */
8779 				rsm = rack_merge_rsm(rack, rsm, next);
8780 				next = RB_NEXT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm);
8781 			} else
8782 				break;
8783 		}
8784 		/* Now what about the previous? */
8785 		prev = RB_PREV(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm);
8786 		while (prev) {
8787 			if (prev->r_flags & RACK_TLP)
8788 				break;
8789 			if (prev->r_flags & RACK_ACKED) {
8790 				/* yep the previous and this can be merged */
8791 				rsm = rack_merge_rsm(rack, prev, rsm);
8792 				prev = RB_PREV(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm);
8793 			} else
8794 				break;
8795 		}
8796 	}
8797 	if (used_ref == 0) {
8798 		counter_u64_add(rack_sack_proc_all, 1);
8799 	} else {
8800 		counter_u64_add(rack_sack_proc_short, 1);
8801 	}
8802 	/* Save off the next one for quick reference. */
8803 	if (rsm)
8804 		nrsm = RB_NEXT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm);
8805 	else
8806 		nrsm = NULL;
8807 	*prsm = rack->r_ctl.rc_sacklast = nrsm;
8808 	/* Pass back the moved. */
8809 	*moved_two = moved;
8810 	return (changed);
8811 }
8812 
8813 static void inline
8814 rack_peer_reneges(struct tcp_rack *rack, struct rack_sendmap *rsm, tcp_seq th_ack)
8815 {
8816 	struct rack_sendmap *tmap;
8817 
8818 	tmap = NULL;
8819 	while (rsm && (rsm->r_flags & RACK_ACKED)) {
8820 		/* Its no longer sacked, mark it so */
8821 		rack->r_ctl.rc_sacked -= (rsm->r_end - rsm->r_start);
8822 #ifdef INVARIANTS
8823 		if (rsm->r_in_tmap) {
8824 			panic("rack:%p rsm:%p flags:0x%x in tmap?",
8825 			      rack, rsm, rsm->r_flags);
8826 		}
8827 #endif
8828 		rsm->r_flags &= ~(RACK_ACKED|RACK_SACK_PASSED|RACK_WAS_SACKPASS);
8829 		/* Rebuild it into our tmap */
8830 		if (tmap == NULL) {
8831 			TAILQ_INSERT_HEAD(&rack->r_ctl.rc_tmap, rsm, r_tnext);
8832 			tmap = rsm;
8833 		} else {
8834 			TAILQ_INSERT_AFTER(&rack->r_ctl.rc_tmap, tmap, rsm, r_tnext);
8835 			tmap = rsm;
8836 		}
8837 		tmap->r_in_tmap = 1;
8838 		rsm = RB_NEXT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm);
8839 	}
8840 	/*
8841 	 * Now lets possibly clear the sack filter so we start
8842 	 * recognizing sacks that cover this area.
8843 	 */
8844 	sack_filter_clear(&rack->r_ctl.rack_sf, th_ack);
8845 
8846 }
8847 
8848 static void
8849 rack_do_decay(struct tcp_rack *rack)
8850 {
8851 	struct timeval res;
8852 
8853 #define	timersub(tvp, uvp, vvp)						\
8854 	do {								\
8855 		(vvp)->tv_sec = (tvp)->tv_sec - (uvp)->tv_sec;		\
8856 		(vvp)->tv_usec = (tvp)->tv_usec - (uvp)->tv_usec;	\
8857 		if ((vvp)->tv_usec < 0) {				\
8858 			(vvp)->tv_sec--;				\
8859 			(vvp)->tv_usec += 1000000;			\
8860 		}							\
8861 	} while (0)
8862 
8863 	timersub(&rack->r_ctl.act_rcv_time, &rack->r_ctl.rc_last_time_decay, &res);
8864 #undef timersub
8865 
8866 	rack->r_ctl.input_pkt++;
8867 	if ((rack->rc_in_persist) ||
8868 	    (res.tv_sec >= 1) ||
8869 	    (rack->rc_tp->snd_max == rack->rc_tp->snd_una)) {
8870 		/*
8871 		 * Check for decay of non-SAD,
8872 		 * we want all SAD detection metrics to
8873 		 * decay 1/4 per second (or more) passed.
8874 		 */
8875 #ifdef NETFLIX_EXP_DETECTION
8876 		uint32_t pkt_delta;
8877 
8878 		pkt_delta = rack->r_ctl.input_pkt - rack->r_ctl.saved_input_pkt;
8879 #endif
8880 		/* Update our saved tracking values */
8881 		rack->r_ctl.saved_input_pkt = rack->r_ctl.input_pkt;
8882 		rack->r_ctl.rc_last_time_decay = rack->r_ctl.act_rcv_time;
8883 		/* Now do we escape without decay? */
8884 #ifdef NETFLIX_EXP_DETECTION
8885 		if (rack->rc_in_persist ||
8886 		    (rack->rc_tp->snd_max == rack->rc_tp->snd_una) ||
8887 		    (pkt_delta < tcp_sad_low_pps)){
8888 			/*
8889 			 * We don't decay idle connections
8890 			 * or ones that have a low input pps.
8891 			 */
8892 			return;
8893 		}
8894 		/* Decay the counters */
8895 		rack->r_ctl.ack_count = ctf_decay_count(rack->r_ctl.ack_count,
8896 							tcp_sad_decay_val);
8897 		rack->r_ctl.sack_count = ctf_decay_count(rack->r_ctl.sack_count,
8898 							 tcp_sad_decay_val);
8899 		rack->r_ctl.sack_moved_extra = ctf_decay_count(rack->r_ctl.sack_moved_extra,
8900 							       tcp_sad_decay_val);
8901 		rack->r_ctl.sack_noextra_move = ctf_decay_count(rack->r_ctl.sack_noextra_move,
8902 								tcp_sad_decay_val);
8903 #endif
8904 	}
8905 }
8906 
8907 static void
8908 rack_process_to_cumack(struct tcpcb *tp, struct tcp_rack *rack, register uint32_t th_ack, uint32_t cts, struct tcpopt *to)
8909 {
8910 	struct rack_sendmap *rsm;
8911 #ifdef INVARIANTS
8912 	struct rack_sendmap *rm;
8913 #endif
8914 
8915 	/*
8916 	 * The ACK point is advancing to th_ack, we must drop off
8917 	 * the packets in the rack log and calculate any eligble
8918 	 * RTT's.
8919 	 */
8920 	rack->r_wanted_output = 1;
8921 
8922 	/* Tend any TLP that has been marked for 1/2 the seq space (its old)  */
8923 	if ((rack->rc_last_tlp_acked_set == 1)&&
8924 	    (rack->rc_last_tlp_past_cumack == 1) &&
8925 	    (SEQ_GT(rack->r_ctl.last_tlp_acked_start, th_ack))) {
8926 		/*
8927 		 * We have reached the point where our last rack
8928 		 * tlp retransmit sequence is ahead of the cum-ack.
8929 		 * This can only happen when the cum-ack moves all
8930 		 * the way around (its been a full 2^^31+1 bytes
8931 		 * or more since we sent a retransmitted TLP). Lets
8932 		 * turn off the valid flag since its not really valid.
8933 		 *
8934 		 * Note since sack's also turn on this event we have
8935 		 * a complication, we have to wait to age it out until
8936 		 * the cum-ack is by the TLP before checking which is
8937 		 * what the next else clause does.
8938 		 */
8939 		rack_log_dsack_event(rack, 9, __LINE__,
8940 				     rack->r_ctl.last_tlp_acked_start,
8941 				     rack->r_ctl.last_tlp_acked_end);
8942 		rack->rc_last_tlp_acked_set = 0;
8943 		rack->rc_last_tlp_past_cumack = 0;
8944 	} else if ((rack->rc_last_tlp_acked_set == 1) &&
8945 		   (rack->rc_last_tlp_past_cumack == 0) &&
8946 		   (SEQ_GEQ(th_ack, rack->r_ctl.last_tlp_acked_end))) {
8947 		/*
8948 		 * It is safe to start aging TLP's out.
8949 		 */
8950 		rack->rc_last_tlp_past_cumack = 1;
8951 	}
8952 	/* We do the same for the tlp send seq as well */
8953 	if ((rack->rc_last_sent_tlp_seq_valid == 1) &&
8954 	    (rack->rc_last_sent_tlp_past_cumack == 1) &&
8955 	    (SEQ_GT(rack->r_ctl.last_sent_tlp_seq,  th_ack))) {
8956 		rack_log_dsack_event(rack, 9, __LINE__,
8957 				     rack->r_ctl.last_sent_tlp_seq,
8958 				     (rack->r_ctl.last_sent_tlp_seq +
8959 				      rack->r_ctl.last_sent_tlp_len));
8960 		rack->rc_last_sent_tlp_seq_valid = 0;
8961 		rack->rc_last_sent_tlp_past_cumack = 0;
8962 	} else if ((rack->rc_last_sent_tlp_seq_valid == 1) &&
8963 		   (rack->rc_last_sent_tlp_past_cumack == 0) &&
8964 		   (SEQ_GEQ(th_ack, rack->r_ctl.last_sent_tlp_seq))) {
8965 		/*
8966 		 * It is safe to start aging TLP's send.
8967 		 */
8968 		rack->rc_last_sent_tlp_past_cumack = 1;
8969 	}
8970 more:
8971 	rsm = RB_MIN(rack_rb_tree_head, &rack->r_ctl.rc_mtree);
8972 	if (rsm == NULL) {
8973 		if ((th_ack - 1) == tp->iss) {
8974 			/*
8975 			 * For the SYN incoming case we will not
8976 			 * have called tcp_output for the sending of
8977 			 * the SYN, so there will be no map. All
8978 			 * other cases should probably be a panic.
8979 			 */
8980 			return;
8981 		}
8982 		if (tp->t_flags & TF_SENTFIN) {
8983 			/* if we sent a FIN we often will not have map */
8984 			return;
8985 		}
8986 #ifdef INVARIANTS
8987 		panic("No rack map tp:%p for state:%d ack:%u rack:%p snd_una:%u snd_max:%u snd_nxt:%u\n",
8988 		      tp,
8989 		      tp->t_state, th_ack, rack,
8990 		      tp->snd_una, tp->snd_max, tp->snd_nxt);
8991 #endif
8992 		return;
8993 	}
8994 	if (SEQ_LT(th_ack, rsm->r_start)) {
8995 		/* Huh map is missing this */
8996 #ifdef INVARIANTS
8997 		printf("Rack map starts at r_start:%u for th_ack:%u huh? ts:%d rs:%d\n",
8998 		       rsm->r_start,
8999 		       th_ack, tp->t_state, rack->r_state);
9000 #endif
9001 		return;
9002 	}
9003 	rack_update_rtt(tp, rack, rsm, to, cts, CUM_ACKED, th_ack);
9004 
9005 	/* Now was it a retransmitted TLP? */
9006 	if ((rsm->r_flags & RACK_TLP) &&
9007 	    (rsm->r_rtr_cnt > 1)) {
9008 		/*
9009 		 * Yes, this rsm was a TLP and retransmitted, remember that
9010 		 * since if a DSACK comes back on this we don't want
9011 		 * to think of it as a reordered segment. This may
9012 		 * get updated again with possibly even other TLPs
9013 		 * in flight, but thats ok. Only when we don't send
9014 		 * a retransmitted TLP for 1/2 the sequences space
9015 		 * will it get turned off (above).
9016 		 */
9017 		if (rack->rc_last_tlp_acked_set &&
9018 		    (is_rsm_inside_declared_tlp_block(rack, rsm))) {
9019 			/*
9020 			 * We already turned this on since the end matches,
9021 			 * the previous one was a partially ack now we
9022 			 * are getting another one (maybe all of it).
9023 			 */
9024 			rack_log_dsack_event(rack, 10, __LINE__, rsm->r_start, rsm->r_end);
9025 			/*
9026 			 * Lets make sure we have all of it though.
9027 			 */
9028 			if (SEQ_LT(rsm->r_start, rack->r_ctl.last_tlp_acked_start)) {
9029 				rack->r_ctl.last_tlp_acked_start = rsm->r_start;
9030 				rack_log_dsack_event(rack, 11, __LINE__, rack->r_ctl.last_tlp_acked_start,
9031 						     rack->r_ctl.last_tlp_acked_end);
9032 			}
9033 			if (SEQ_GT(rsm->r_end, rack->r_ctl.last_tlp_acked_end)) {
9034 				rack->r_ctl.last_tlp_acked_end = rsm->r_end;
9035 				rack_log_dsack_event(rack, 11, __LINE__, rack->r_ctl.last_tlp_acked_start,
9036 						     rack->r_ctl.last_tlp_acked_end);
9037 			}
9038 		} else {
9039 			rack->rc_last_tlp_past_cumack = 1;
9040 			rack->r_ctl.last_tlp_acked_start = rsm->r_start;
9041 			rack->r_ctl.last_tlp_acked_end = rsm->r_end;
9042 			rack->rc_last_tlp_acked_set = 1;
9043 			rack_log_dsack_event(rack, 8, __LINE__, rsm->r_start, rsm->r_end);
9044 		}
9045 	}
9046 	/* Now do we consume the whole thing? */
9047 	if (SEQ_GEQ(th_ack, rsm->r_end)) {
9048 		/* Its all consumed. */
9049 		uint32_t left;
9050 		uint8_t newly_acked;
9051 
9052 		rack_log_map_chg(tp, rack, NULL, rsm, NULL, MAP_FREE, rsm->r_end, __LINE__);
9053 		rack->r_ctl.rc_holes_rxt -= rsm->r_rtr_bytes;
9054 		rsm->r_rtr_bytes = 0;
9055 		/* Record the time of highest cumack sent */
9056 		rack->r_ctl.rc_gp_cumack_ts = rsm->r_tim_lastsent[(rsm->r_rtr_cnt-1)];
9057 #ifndef INVARIANTS
9058 		(void)RB_REMOVE(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm);
9059 #else
9060 		rm = RB_REMOVE(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm);
9061 		if (rm != rsm) {
9062 			panic("removing head in rack:%p rsm:%p rm:%p",
9063 			      rack, rsm, rm);
9064 		}
9065 #endif
9066 		if (rsm->r_in_tmap) {
9067 			TAILQ_REMOVE(&rack->r_ctl.rc_tmap, rsm, r_tnext);
9068 			rsm->r_in_tmap = 0;
9069 		}
9070 		newly_acked = 1;
9071 		if (rsm->r_flags & RACK_ACKED) {
9072 			/*
9073 			 * It was acked on the scoreboard -- remove
9074 			 * it from total
9075 			 */
9076 			rack->r_ctl.rc_sacked -= (rsm->r_end - rsm->r_start);
9077 			newly_acked = 0;
9078 		} else if (rsm->r_flags & RACK_SACK_PASSED) {
9079 			/*
9080 			 * There are segments ACKED on the
9081 			 * scoreboard further up. We are seeing
9082 			 * reordering.
9083 			 */
9084 			rsm->r_flags &= ~RACK_SACK_PASSED;
9085 			rsm->r_ack_arrival = rack_to_usec_ts(&rack->r_ctl.act_rcv_time);
9086 			rsm->r_flags |= RACK_ACKED;
9087 			rack->r_ctl.rc_reorder_ts = cts;
9088 			if (rack->r_ent_rec_ns) {
9089 				/*
9090 				 * We have sent no more, and we saw an sack
9091 				 * then ack arrive.
9092 				 */
9093 				rack->r_might_revert = 1;
9094 			}
9095 		}
9096 		if ((rsm->r_flags & RACK_TO_REXT) &&
9097 		    (tp->t_flags & TF_RCVD_TSTMP) &&
9098 		    (to->to_flags & TOF_TS) &&
9099 		    (to->to_tsecr != 0) &&
9100 		    (tp->t_flags & TF_PREVVALID)) {
9101 			/*
9102 			 * We can use the timestamp to see
9103 			 * if this retransmission was from the
9104 			 * first transmit. If so we made a mistake.
9105 			 */
9106 			tp->t_flags &= ~TF_PREVVALID;
9107 			if (to->to_tsecr == rack_ts_to_msec(rsm->r_tim_lastsent[0])) {
9108 				/* The first transmit is what this ack is for */
9109 				rack_cong_signal(tp, CC_RTO_ERR, th_ack, __LINE__);
9110 			}
9111 		}
9112 		left = th_ack - rsm->r_end;
9113 		if (rack->app_limited_needs_set && newly_acked)
9114 			rack_need_set_test(tp, rack, rsm, th_ack, __LINE__, RACK_USE_END_OR_THACK);
9115 		/* Free back to zone */
9116 		rack_free(rack, rsm);
9117 		if (left) {
9118 			goto more;
9119 		}
9120 		/* Check for reneging */
9121 		rsm = RB_MIN(rack_rb_tree_head, &rack->r_ctl.rc_mtree);
9122 		if (rsm && (rsm->r_flags & RACK_ACKED) && (th_ack == rsm->r_start)) {
9123 			/*
9124 			 * The peer has moved snd_una up to
9125 			 * the edge of this send, i.e. one
9126 			 * that it had previously acked. The only
9127 			 * way that can be true if the peer threw
9128 			 * away data (space issues) that it had
9129 			 * previously sacked (else it would have
9130 			 * given us snd_una up to (rsm->r_end).
9131 			 * We need to undo the acked markings here.
9132 			 *
9133 			 * Note we have to look to make sure th_ack is
9134 			 * our rsm->r_start in case we get an old ack
9135 			 * where th_ack is behind snd_una.
9136 			 */
9137 			rack_peer_reneges(rack, rsm, th_ack);
9138 		}
9139 		return;
9140 	}
9141 	if (rsm->r_flags & RACK_ACKED) {
9142 		/*
9143 		 * It was acked on the scoreboard -- remove it from
9144 		 * total for the part being cum-acked.
9145 		 */
9146 		rack->r_ctl.rc_sacked -= (th_ack - rsm->r_start);
9147 	}
9148 	/*
9149 	 * Clear the dup ack count for
9150 	 * the piece that remains.
9151 	 */
9152 	rsm->r_dupack = 0;
9153 	rack_log_retran_reason(rack, rsm, __LINE__, 0, 2);
9154 	if (rsm->r_rtr_bytes) {
9155 		/*
9156 		 * It was retransmitted adjust the
9157 		 * sack holes for what was acked.
9158 		 */
9159 		int ack_am;
9160 
9161 		ack_am = (th_ack - rsm->r_start);
9162 		if (ack_am >= rsm->r_rtr_bytes) {
9163 			rack->r_ctl.rc_holes_rxt -= ack_am;
9164 			rsm->r_rtr_bytes -= ack_am;
9165 		}
9166 	}
9167 	/*
9168 	 * Update where the piece starts and record
9169 	 * the time of send of highest cumack sent.
9170 	 */
9171 	rack->r_ctl.rc_gp_cumack_ts = rsm->r_tim_lastsent[(rsm->r_rtr_cnt-1)];
9172 	rack_log_map_chg(tp, rack, NULL, rsm, NULL, MAP_TRIM_HEAD, th_ack, __LINE__);
9173 	/* Now we need to move our offset forward too */
9174 	if (rsm->m && (rsm->orig_m_len != rsm->m->m_len)) {
9175 		/* Fix up the orig_m_len and possibly the mbuf offset */
9176 		rack_adjust_orig_mlen(rsm);
9177 	}
9178 	rsm->soff += (th_ack - rsm->r_start);
9179 	rsm->r_start = th_ack;
9180 	/* Now do we need to move the mbuf fwd too? */
9181 	if (rsm->m) {
9182 		while (rsm->soff >= rsm->m->m_len) {
9183 			rsm->soff -= rsm->m->m_len;
9184 			rsm->m = rsm->m->m_next;
9185 			KASSERT((rsm->m != NULL),
9186 				(" nrsm:%p hit at soff:%u null m",
9187 				 rsm, rsm->soff));
9188 		}
9189 		rsm->orig_m_len = rsm->m->m_len;
9190 	}
9191 	if (rack->app_limited_needs_set)
9192 		rack_need_set_test(tp, rack, rsm, tp->snd_una, __LINE__, RACK_USE_BEG);
9193 }
9194 
9195 static void
9196 rack_handle_might_revert(struct tcpcb *tp, struct tcp_rack *rack)
9197 {
9198 	struct rack_sendmap *rsm;
9199 	int sack_pass_fnd = 0;
9200 
9201 	if (rack->r_might_revert) {
9202 		/*
9203 		 * Ok we have reordering, have not sent anything, we
9204 		 * might want to revert the congestion state if nothing
9205 		 * further has SACK_PASSED on it. Lets check.
9206 		 *
9207 		 * We also get here when we have DSACKs come in for
9208 		 * all the data that we FR'd. Note that a rxt or tlp
9209 		 * timer clears this from happening.
9210 		 */
9211 
9212 		TAILQ_FOREACH(rsm, &rack->r_ctl.rc_tmap, r_tnext) {
9213 			if (rsm->r_flags & RACK_SACK_PASSED) {
9214 				sack_pass_fnd = 1;
9215 				break;
9216 			}
9217 		}
9218 		if (sack_pass_fnd == 0) {
9219 			/*
9220 			 * We went into recovery
9221 			 * incorrectly due to reordering!
9222 			 */
9223 			int orig_cwnd;
9224 
9225 			rack->r_ent_rec_ns = 0;
9226 			orig_cwnd = tp->snd_cwnd;
9227 			tp->snd_ssthresh = rack->r_ctl.rc_ssthresh_at_erec;
9228 			tp->snd_recover = tp->snd_una;
9229 			rack_log_to_prr(rack, 14, orig_cwnd, __LINE__);
9230 			EXIT_RECOVERY(tp->t_flags);
9231 		}
9232 		rack->r_might_revert = 0;
9233 	}
9234 }
9235 
9236 #ifdef NETFLIX_EXP_DETECTION
9237 static void
9238 rack_do_detection(struct tcpcb *tp, struct tcp_rack *rack,  uint32_t bytes_this_ack, uint32_t segsiz)
9239 {
9240 	if ((rack->do_detection || tcp_force_detection) &&
9241 	    tcp_sack_to_ack_thresh &&
9242 	    tcp_sack_to_move_thresh &&
9243 	    ((rack->r_ctl.rc_num_maps_alloced > tcp_map_minimum) || rack->sack_attack_disable)) {
9244 		/*
9245 		 * We have thresholds set to find
9246 		 * possible attackers and disable sack.
9247 		 * Check them.
9248 		 */
9249 		uint64_t ackratio, moveratio, movetotal;
9250 
9251 		/* Log detecting */
9252 		rack_log_sad(rack, 1);
9253 		ackratio = (uint64_t)(rack->r_ctl.sack_count);
9254 		ackratio *= (uint64_t)(1000);
9255 		if (rack->r_ctl.ack_count)
9256 			ackratio /= (uint64_t)(rack->r_ctl.ack_count);
9257 		else {
9258 			/* We really should not hit here */
9259 			ackratio = 1000;
9260 		}
9261 		if ((rack->sack_attack_disable == 0) &&
9262 		    (ackratio > rack_highest_sack_thresh_seen))
9263 			rack_highest_sack_thresh_seen = (uint32_t)ackratio;
9264 		movetotal = rack->r_ctl.sack_moved_extra;
9265 		movetotal += rack->r_ctl.sack_noextra_move;
9266 		moveratio = rack->r_ctl.sack_moved_extra;
9267 		moveratio *= (uint64_t)1000;
9268 		if (movetotal)
9269 			moveratio /= movetotal;
9270 		else {
9271 			/* No moves, thats pretty good */
9272 			moveratio = 0;
9273 		}
9274 		if ((rack->sack_attack_disable == 0) &&
9275 		    (moveratio > rack_highest_move_thresh_seen))
9276 			rack_highest_move_thresh_seen = (uint32_t)moveratio;
9277 		if (rack->sack_attack_disable == 0) {
9278 			if ((ackratio > tcp_sack_to_ack_thresh) &&
9279 			    (moveratio > tcp_sack_to_move_thresh)) {
9280 				/* Disable sack processing */
9281 				rack->sack_attack_disable = 1;
9282 				if (rack->r_rep_attack == 0) {
9283 					rack->r_rep_attack = 1;
9284 					counter_u64_add(rack_sack_attacks_detected, 1);
9285 				}
9286 				if (tcp_attack_on_turns_on_logging) {
9287 					/*
9288 					 * Turn on logging, used for debugging
9289 					 * false positives.
9290 					 */
9291 					rack->rc_tp->t_logstate = tcp_attack_on_turns_on_logging;
9292 				}
9293 				/* Clamp the cwnd at flight size */
9294 				rack->r_ctl.rc_saved_cwnd = rack->rc_tp->snd_cwnd;
9295 				rack->rc_tp->snd_cwnd = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
9296 				rack_log_sad(rack, 2);
9297 			}
9298 		} else {
9299 			/* We are sack-disabled check for false positives */
9300 			if ((ackratio <= tcp_restoral_thresh) ||
9301 			    (rack->r_ctl.rc_num_maps_alloced  < tcp_map_minimum)) {
9302 				rack->sack_attack_disable = 0;
9303 				rack_log_sad(rack, 3);
9304 				/* Restart counting */
9305 				rack->r_ctl.sack_count = 0;
9306 				rack->r_ctl.sack_moved_extra = 0;
9307 				rack->r_ctl.sack_noextra_move = 1;
9308 				rack->r_ctl.ack_count = max(1,
9309 				      (bytes_this_ack / segsiz));
9310 
9311 				if (rack->r_rep_reverse == 0) {
9312 					rack->r_rep_reverse = 1;
9313 					counter_u64_add(rack_sack_attacks_reversed, 1);
9314 				}
9315 				/* Restore the cwnd */
9316 				if (rack->r_ctl.rc_saved_cwnd > rack->rc_tp->snd_cwnd)
9317 					rack->rc_tp->snd_cwnd = rack->r_ctl.rc_saved_cwnd;
9318 			}
9319 		}
9320 	}
9321 }
9322 #endif
9323 
9324 static int
9325 rack_note_dsack(struct tcp_rack *rack, tcp_seq start, tcp_seq end)
9326 {
9327 
9328 	uint32_t am, l_end;
9329 	int was_tlp = 0;
9330 
9331 	if (SEQ_GT(end, start))
9332 		am = end - start;
9333 	else
9334 		am = 0;
9335 	if ((rack->rc_last_tlp_acked_set ) &&
9336 	    (SEQ_GEQ(start, rack->r_ctl.last_tlp_acked_start)) &&
9337 	    (SEQ_LEQ(end, rack->r_ctl.last_tlp_acked_end))) {
9338 		/*
9339 		 * The DSACK is because of a TLP which we don't
9340 		 * do anything with the reordering window over since
9341 		 * it was not reordering that caused the DSACK but
9342 		 * our previous retransmit TLP.
9343 		 */
9344 		rack_log_dsack_event(rack, 7, __LINE__, start, end);
9345 		was_tlp = 1;
9346 		goto skip_dsack_round;
9347 	}
9348 	if (rack->rc_last_sent_tlp_seq_valid) {
9349 		l_end = rack->r_ctl.last_sent_tlp_seq + rack->r_ctl.last_sent_tlp_len;
9350 		if (SEQ_GEQ(start, rack->r_ctl.last_sent_tlp_seq) &&
9351 		    (SEQ_LEQ(end, l_end))) {
9352 			/*
9353 			 * This dsack is from the last sent TLP, ignore it
9354 			 * for reordering purposes.
9355 			 */
9356 			rack_log_dsack_event(rack, 7, __LINE__, start, end);
9357 			was_tlp = 1;
9358 			goto skip_dsack_round;
9359 		}
9360 	}
9361 	if (rack->rc_dsack_round_seen == 0) {
9362 		rack->rc_dsack_round_seen = 1;
9363 		rack->r_ctl.dsack_round_end = rack->rc_tp->snd_max;
9364 		rack->r_ctl.num_dsack++;
9365 		rack->r_ctl.dsack_persist = 16;	/* 16 is from the standard */
9366 		rack_log_dsack_event(rack, 2, __LINE__, 0, 0);
9367 	}
9368 skip_dsack_round:
9369 	/*
9370 	 * We keep track of how many DSACK blocks we get
9371 	 * after a recovery incident.
9372 	 */
9373 	rack->r_ctl.dsack_byte_cnt += am;
9374 	if (!IN_FASTRECOVERY(rack->rc_tp->t_flags) &&
9375 	    rack->r_ctl.retran_during_recovery &&
9376 	    (rack->r_ctl.dsack_byte_cnt >= rack->r_ctl.retran_during_recovery)) {
9377 		/*
9378 		 * False recovery most likely culprit is reordering. If
9379 		 * nothing else is missing we need to revert.
9380 		 */
9381 		rack->r_might_revert = 1;
9382 		rack_handle_might_revert(rack->rc_tp, rack);
9383 		rack->r_might_revert = 0;
9384 		rack->r_ctl.retran_during_recovery = 0;
9385 		rack->r_ctl.dsack_byte_cnt = 0;
9386 	}
9387 	return (was_tlp);
9388 }
9389 
9390 static uint32_t
9391 do_rack_compute_pipe(struct tcpcb *tp, struct tcp_rack *rack, uint32_t snd_una)
9392 {
9393 	return (((tp->snd_max - snd_una) - rack->r_ctl.rc_sacked) + rack->r_ctl.rc_holes_rxt);
9394 }
9395 
9396 static int32_t
9397 rack_compute_pipe(struct tcpcb *tp)
9398 {
9399 	return ((int32_t)do_rack_compute_pipe(tp,
9400 					      (struct tcp_rack *)tp->t_fb_ptr,
9401 					      tp->snd_una));
9402 }
9403 
9404 static void
9405 rack_update_prr(struct tcpcb *tp, struct tcp_rack *rack, uint32_t changed, tcp_seq th_ack)
9406 {
9407 	/* Deal with changed and PRR here (in recovery only) */
9408 	uint32_t pipe, snd_una;
9409 
9410 	rack->r_ctl.rc_prr_delivered += changed;
9411 
9412 	if (sbavail(&rack->rc_inp->inp_socket->so_snd) <= (tp->snd_max - tp->snd_una)) {
9413 		/*
9414 		 * It is all outstanding, we are application limited
9415 		 * and thus we don't need more room to send anything.
9416 		 * Note we use tp->snd_una here and not th_ack because
9417 		 * the data as yet not been cut from the sb.
9418 		 */
9419 		rack->r_ctl.rc_prr_sndcnt = 0;
9420 		return;
9421 	}
9422 	/* Compute prr_sndcnt */
9423 	if (SEQ_GT(tp->snd_una, th_ack)) {
9424 		snd_una = tp->snd_una;
9425 	} else {
9426 		snd_una = th_ack;
9427 	}
9428 	pipe = do_rack_compute_pipe(tp, rack, snd_una);
9429 	if (pipe > tp->snd_ssthresh) {
9430 		long sndcnt;
9431 
9432 		sndcnt = rack->r_ctl.rc_prr_delivered * tp->snd_ssthresh;
9433 		if (rack->r_ctl.rc_prr_recovery_fs > 0)
9434 			sndcnt /= (long)rack->r_ctl.rc_prr_recovery_fs;
9435 		else {
9436 			rack->r_ctl.rc_prr_sndcnt = 0;
9437 			rack_log_to_prr(rack, 9, 0, __LINE__);
9438 			sndcnt = 0;
9439 		}
9440 		sndcnt++;
9441 		if (sndcnt > (long)rack->r_ctl.rc_prr_out)
9442 			sndcnt -= rack->r_ctl.rc_prr_out;
9443 		else
9444 			sndcnt = 0;
9445 		rack->r_ctl.rc_prr_sndcnt = sndcnt;
9446 		rack_log_to_prr(rack, 10, 0, __LINE__);
9447 	} else {
9448 		uint32_t limit;
9449 
9450 		if (rack->r_ctl.rc_prr_delivered > rack->r_ctl.rc_prr_out)
9451 			limit = (rack->r_ctl.rc_prr_delivered - rack->r_ctl.rc_prr_out);
9452 		else
9453 			limit = 0;
9454 		if (changed > limit)
9455 			limit = changed;
9456 		limit += ctf_fixed_maxseg(tp);
9457 		if (tp->snd_ssthresh > pipe) {
9458 			rack->r_ctl.rc_prr_sndcnt = min((tp->snd_ssthresh - pipe), limit);
9459 			rack_log_to_prr(rack, 11, 0, __LINE__);
9460 		} else {
9461 			rack->r_ctl.rc_prr_sndcnt = min(0, limit);
9462 			rack_log_to_prr(rack, 12, 0, __LINE__);
9463 		}
9464 	}
9465 }
9466 
9467 static void
9468 rack_log_ack(struct tcpcb *tp, struct tcpopt *to, struct tcphdr *th, int entered_recovery, int dup_ack_struck)
9469 {
9470 	uint32_t changed;
9471 	struct tcp_rack *rack;
9472 	struct rack_sendmap *rsm;
9473 	struct sackblk sack, sack_blocks[TCP_MAX_SACK + 1];
9474 	register uint32_t th_ack;
9475 	int32_t i, j, k, num_sack_blks = 0;
9476 	uint32_t cts, acked, ack_point;
9477 	int loop_start = 0, moved_two = 0;
9478 	uint32_t tsused;
9479 
9480 
9481 	INP_WLOCK_ASSERT(tptoinpcb(tp));
9482 	if (tcp_get_flags(th) & TH_RST) {
9483 		/* We don't log resets */
9484 		return;
9485 	}
9486 	rack = (struct tcp_rack *)tp->t_fb_ptr;
9487 	cts = tcp_get_usecs(NULL);
9488 	rsm = RB_MIN(rack_rb_tree_head, &rack->r_ctl.rc_mtree);
9489 	changed = 0;
9490 	th_ack = th->th_ack;
9491 	if (rack->sack_attack_disable == 0)
9492 		rack_do_decay(rack);
9493 	if (BYTES_THIS_ACK(tp, th) >= ctf_fixed_maxseg(rack->rc_tp)) {
9494 		/*
9495 		 * You only get credit for
9496 		 * MSS and greater (and you get extra
9497 		 * credit for larger cum-ack moves).
9498 		 */
9499 		int ac;
9500 
9501 		ac = BYTES_THIS_ACK(tp, th) / ctf_fixed_maxseg(rack->rc_tp);
9502 		rack->r_ctl.ack_count += ac;
9503 		counter_u64_add(rack_ack_total, ac);
9504 	}
9505 	if (rack->r_ctl.ack_count > 0xfff00000) {
9506 		/*
9507 		 * reduce the number to keep us under
9508 		 * a uint32_t.
9509 		 */
9510 		rack->r_ctl.ack_count /= 2;
9511 		rack->r_ctl.sack_count /= 2;
9512 	}
9513 	if (SEQ_GT(th_ack, tp->snd_una)) {
9514 		rack_log_progress_event(rack, tp, ticks, PROGRESS_UPDATE, __LINE__);
9515 		tp->t_acktime = ticks;
9516 	}
9517 	if (rsm && SEQ_GT(th_ack, rsm->r_start))
9518 		changed = th_ack - rsm->r_start;
9519 	if (changed) {
9520 		rack_process_to_cumack(tp, rack, th_ack, cts, to);
9521 	}
9522 	if ((to->to_flags & TOF_SACK) == 0) {
9523 		/* We are done nothing left and no sack. */
9524 		rack_handle_might_revert(tp, rack);
9525 		/*
9526 		 * For cases where we struck a dup-ack
9527 		 * with no SACK, add to the changes so
9528 		 * PRR will work right.
9529 		 */
9530 		if (dup_ack_struck && (changed == 0)) {
9531 			changed += ctf_fixed_maxseg(rack->rc_tp);
9532 		}
9533 		goto out;
9534 	}
9535 	/* Sack block processing */
9536 	if (SEQ_GT(th_ack, tp->snd_una))
9537 		ack_point = th_ack;
9538 	else
9539 		ack_point = tp->snd_una;
9540 	for (i = 0; i < to->to_nsacks; i++) {
9541 		bcopy((to->to_sacks + i * TCPOLEN_SACK),
9542 		      &sack, sizeof(sack));
9543 		sack.start = ntohl(sack.start);
9544 		sack.end = ntohl(sack.end);
9545 		if (SEQ_GT(sack.end, sack.start) &&
9546 		    SEQ_GT(sack.start, ack_point) &&
9547 		    SEQ_LT(sack.start, tp->snd_max) &&
9548 		    SEQ_GT(sack.end, ack_point) &&
9549 		    SEQ_LEQ(sack.end, tp->snd_max)) {
9550 			sack_blocks[num_sack_blks] = sack;
9551 			num_sack_blks++;
9552 		} else if (SEQ_LEQ(sack.start, th_ack) &&
9553 			   SEQ_LEQ(sack.end, th_ack)) {
9554 			int was_tlp;
9555 
9556 			was_tlp = rack_note_dsack(rack, sack.start, sack.end);
9557 			/*
9558 			 * Its a D-SACK block.
9559 			 */
9560 			tcp_record_dsack(tp, sack.start, sack.end, was_tlp);
9561 		}
9562 	}
9563 	if (rack->rc_dsack_round_seen) {
9564 		/* Is the dsack roound over? */
9565 		if (SEQ_GEQ(th_ack, rack->r_ctl.dsack_round_end)) {
9566 			/* Yes it is */
9567 			rack->rc_dsack_round_seen = 0;
9568 			rack_log_dsack_event(rack, 3, __LINE__, 0, 0);
9569 		}
9570 	}
9571 	/*
9572 	 * Sort the SACK blocks so we can update the rack scoreboard with
9573 	 * just one pass.
9574 	 */
9575 	num_sack_blks = sack_filter_blks(&rack->r_ctl.rack_sf, sack_blocks,
9576 					 num_sack_blks, th->th_ack);
9577 	ctf_log_sack_filter(rack->rc_tp, num_sack_blks, sack_blocks);
9578 	if (num_sack_blks == 0) {
9579 		/* Nothing to sack (DSACKs?) */
9580 		goto out_with_totals;
9581 	}
9582 	if (num_sack_blks < 2) {
9583 		/* Only one, we don't need to sort */
9584 		goto do_sack_work;
9585 	}
9586 	/* Sort the sacks */
9587 	for (i = 0; i < num_sack_blks; i++) {
9588 		for (j = i + 1; j < num_sack_blks; j++) {
9589 			if (SEQ_GT(sack_blocks[i].end, sack_blocks[j].end)) {
9590 				sack = sack_blocks[i];
9591 				sack_blocks[i] = sack_blocks[j];
9592 				sack_blocks[j] = sack;
9593 			}
9594 		}
9595 	}
9596 	/*
9597 	 * Now are any of the sack block ends the same (yes some
9598 	 * implementations send these)?
9599 	 */
9600 again:
9601 	if (num_sack_blks == 0)
9602 		goto out_with_totals;
9603 	if (num_sack_blks > 1) {
9604 		for (i = 0; i < num_sack_blks; i++) {
9605 			for (j = i + 1; j < num_sack_blks; j++) {
9606 				if (sack_blocks[i].end == sack_blocks[j].end) {
9607 					/*
9608 					 * Ok these two have the same end we
9609 					 * want the smallest end and then
9610 					 * throw away the larger and start
9611 					 * again.
9612 					 */
9613 					if (SEQ_LT(sack_blocks[j].start, sack_blocks[i].start)) {
9614 						/*
9615 						 * The second block covers
9616 						 * more area use that
9617 						 */
9618 						sack_blocks[i].start = sack_blocks[j].start;
9619 					}
9620 					/*
9621 					 * Now collapse out the dup-sack and
9622 					 * lower the count
9623 					 */
9624 					for (k = (j + 1); k < num_sack_blks; k++) {
9625 						sack_blocks[j].start = sack_blocks[k].start;
9626 						sack_blocks[j].end = sack_blocks[k].end;
9627 						j++;
9628 					}
9629 					num_sack_blks--;
9630 					goto again;
9631 				}
9632 			}
9633 		}
9634 	}
9635 do_sack_work:
9636 	/*
9637 	 * First lets look to see if
9638 	 * we have retransmitted and
9639 	 * can use the transmit next?
9640 	 */
9641 	rsm = TAILQ_FIRST(&rack->r_ctl.rc_tmap);
9642 	if (rsm &&
9643 	    SEQ_GT(sack_blocks[0].end, rsm->r_start) &&
9644 	    SEQ_LT(sack_blocks[0].start, rsm->r_end)) {
9645 		/*
9646 		 * We probably did the FR and the next
9647 		 * SACK in continues as we would expect.
9648 		 */
9649 		acked = rack_proc_sack_blk(tp, rack, &sack_blocks[0], to, &rsm, cts, &moved_two);
9650 		if (acked) {
9651 			rack->r_wanted_output = 1;
9652 			changed += acked;
9653 		}
9654 		if (num_sack_blks == 1) {
9655 			/*
9656 			 * This is what we would expect from
9657 			 * a normal implementation to happen
9658 			 * after we have retransmitted the FR,
9659 			 * i.e the sack-filter pushes down
9660 			 * to 1 block and the next to be retransmitted
9661 			 * is the sequence in the sack block (has more
9662 			 * are acked). Count this as ACK'd data to boost
9663 			 * up the chances of recovering any false positives.
9664 			 */
9665 			rack->r_ctl.ack_count += (acked / ctf_fixed_maxseg(rack->rc_tp));
9666 			counter_u64_add(rack_ack_total, (acked / ctf_fixed_maxseg(rack->rc_tp)));
9667 			counter_u64_add(rack_express_sack, 1);
9668 			if (rack->r_ctl.ack_count > 0xfff00000) {
9669 				/*
9670 				 * reduce the number to keep us under
9671 				 * a uint32_t.
9672 				 */
9673 				rack->r_ctl.ack_count /= 2;
9674 				rack->r_ctl.sack_count /= 2;
9675 			}
9676 			goto out_with_totals;
9677 		} else {
9678 			/*
9679 			 * Start the loop through the
9680 			 * rest of blocks, past the first block.
9681 			 */
9682 			moved_two = 0;
9683 			loop_start = 1;
9684 		}
9685 	}
9686 	/* Its a sack of some sort */
9687 	rack->r_ctl.sack_count++;
9688 	if (rack->r_ctl.sack_count > 0xfff00000) {
9689 		/*
9690 		 * reduce the number to keep us under
9691 		 * a uint32_t.
9692 		 */
9693 		rack->r_ctl.ack_count /= 2;
9694 		rack->r_ctl.sack_count /= 2;
9695 	}
9696 	counter_u64_add(rack_sack_total, 1);
9697 	if (rack->sack_attack_disable) {
9698 		/* An attacker disablement is in place */
9699 		if (num_sack_blks > 1) {
9700 			rack->r_ctl.sack_count += (num_sack_blks - 1);
9701 			rack->r_ctl.sack_moved_extra++;
9702 			counter_u64_add(rack_move_some, 1);
9703 			if (rack->r_ctl.sack_moved_extra > 0xfff00000) {
9704 				rack->r_ctl.sack_moved_extra /= 2;
9705 				rack->r_ctl.sack_noextra_move /= 2;
9706 			}
9707 		}
9708 		goto out;
9709 	}
9710 	rsm = rack->r_ctl.rc_sacklast;
9711 	for (i = loop_start; i < num_sack_blks; i++) {
9712 		acked = rack_proc_sack_blk(tp, rack, &sack_blocks[i], to, &rsm, cts, &moved_two);
9713 		if (acked) {
9714 			rack->r_wanted_output = 1;
9715 			changed += acked;
9716 		}
9717 		if (moved_two) {
9718 			/*
9719 			 * If we did not get a SACK for at least a MSS and
9720 			 * had to move at all, or if we moved more than our
9721 			 * threshold, it counts against the "extra" move.
9722 			 */
9723 			rack->r_ctl.sack_moved_extra += moved_two;
9724 			counter_u64_add(rack_move_some, 1);
9725 		} else {
9726 			/*
9727 			 * else we did not have to move
9728 			 * any more than we would expect.
9729 			 */
9730 			rack->r_ctl.sack_noextra_move++;
9731 			counter_u64_add(rack_move_none, 1);
9732 		}
9733 		if (moved_two && (acked < ctf_fixed_maxseg(rack->rc_tp))) {
9734 			/*
9735 			 * If the SACK was not a full MSS then
9736 			 * we add to sack_count the number of
9737 			 * MSS's (or possibly more than
9738 			 * a MSS if its a TSO send) we had to skip by.
9739 			 */
9740 			rack->r_ctl.sack_count += moved_two;
9741 			counter_u64_add(rack_sack_total, moved_two);
9742 		}
9743 		/*
9744 		 * Now we need to setup for the next
9745 		 * round. First we make sure we won't
9746 		 * exceed the size of our uint32_t on
9747 		 * the various counts, and then clear out
9748 		 * moved_two.
9749 		 */
9750 		if ((rack->r_ctl.sack_moved_extra > 0xfff00000) ||
9751 		    (rack->r_ctl.sack_noextra_move > 0xfff00000)) {
9752 			rack->r_ctl.sack_moved_extra /= 2;
9753 			rack->r_ctl.sack_noextra_move /= 2;
9754 		}
9755 		if (rack->r_ctl.sack_count > 0xfff00000) {
9756 			rack->r_ctl.ack_count /= 2;
9757 			rack->r_ctl.sack_count /= 2;
9758 		}
9759 		moved_two = 0;
9760 	}
9761 out_with_totals:
9762 	if (num_sack_blks > 1) {
9763 		/*
9764 		 * You get an extra stroke if
9765 		 * you have more than one sack-blk, this
9766 		 * could be where we are skipping forward
9767 		 * and the sack-filter is still working, or
9768 		 * it could be an attacker constantly
9769 		 * moving us.
9770 		 */
9771 		rack->r_ctl.sack_moved_extra++;
9772 		counter_u64_add(rack_move_some, 1);
9773 	}
9774 out:
9775 #ifdef NETFLIX_EXP_DETECTION
9776 	rack_do_detection(tp, rack, BYTES_THIS_ACK(tp, th), ctf_fixed_maxseg(rack->rc_tp));
9777 #endif
9778 	if (changed) {
9779 		/* Something changed cancel the rack timer */
9780 		rack_timer_cancel(tp, rack, rack->r_ctl.rc_rcvtime, __LINE__);
9781 	}
9782 	tsused = tcp_get_usecs(NULL);
9783 	rsm = tcp_rack_output(tp, rack, tsused);
9784 	if ((!IN_FASTRECOVERY(tp->t_flags)) &&
9785 	    rsm &&
9786 	    ((rsm->r_flags & RACK_MUST_RXT) == 0)) {
9787 		/* Enter recovery */
9788 		entered_recovery = 1;
9789 		rack_cong_signal(tp, CC_NDUPACK, tp->snd_una, __LINE__);
9790 		/*
9791 		 * When we enter recovery we need to assure we send
9792 		 * one packet.
9793 		 */
9794 		if (rack->rack_no_prr == 0) {
9795 			rack->r_ctl.rc_prr_sndcnt = ctf_fixed_maxseg(tp);
9796 			rack_log_to_prr(rack, 8, 0, __LINE__);
9797 		}
9798 		rack->r_timer_override = 1;
9799 		rack->r_early = 0;
9800 		rack->r_ctl.rc_agg_early = 0;
9801 	} else if (IN_FASTRECOVERY(tp->t_flags) &&
9802 		   rsm &&
9803 		   (rack->r_rr_config == 3)) {
9804 		/*
9805 		 * Assure we can output and we get no
9806 		 * remembered pace time except the retransmit.
9807 		 */
9808 		rack->r_timer_override = 1;
9809 		rack->r_ctl.rc_hpts_flags &= ~PACE_PKT_OUTPUT;
9810 		rack->r_ctl.rc_resend = rsm;
9811 	}
9812 	if (IN_FASTRECOVERY(tp->t_flags) &&
9813 	    (rack->rack_no_prr == 0) &&
9814 	    (entered_recovery == 0)) {
9815 		rack_update_prr(tp, rack, changed, th_ack);
9816 		if ((rsm && (rack->r_ctl.rc_prr_sndcnt >= ctf_fixed_maxseg(tp)) &&
9817 		     ((tcp_in_hpts(rack->rc_inp) == 0) &&
9818 		      ((rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT) == 0)))) {
9819 			/*
9820 			 * If you are pacing output you don't want
9821 			 * to override.
9822 			 */
9823 			rack->r_early = 0;
9824 			rack->r_ctl.rc_agg_early = 0;
9825 			rack->r_timer_override = 1;
9826 		}
9827 	}
9828 }
9829 
9830 static void
9831 rack_strike_dupack(struct tcp_rack *rack)
9832 {
9833 	struct rack_sendmap *rsm;
9834 
9835 	rsm = TAILQ_FIRST(&rack->r_ctl.rc_tmap);
9836 	while (rsm && (rsm->r_dupack >= DUP_ACK_THRESHOLD)) {
9837 		rsm = TAILQ_NEXT(rsm, r_tnext);
9838 		if (rsm->r_flags & RACK_MUST_RXT) {
9839 			/* Sendmap entries that are marked to
9840 			 * be retransmitted do not need dupack's
9841 			 * struck. We get these marks for a number
9842 			 * of reasons (rxt timeout with no sack,
9843 			 * mtu change, or rwnd collapses). When
9844 			 * these events occur, we know we must retransmit
9845 			 * them and mark the sendmap entries. Dupack counting
9846 			 * is not needed since we are already set to retransmit
9847 			 * it as soon as we can.
9848 			 */
9849 			continue;
9850 		}
9851 	}
9852 	if (rsm && (rsm->r_dupack < 0xff)) {
9853 		rsm->r_dupack++;
9854 		if (rsm->r_dupack >= DUP_ACK_THRESHOLD) {
9855 			struct timeval tv;
9856 			uint32_t cts;
9857 			/*
9858 			 * Here we see if we need to retransmit. For
9859 			 * a SACK type connection if enough time has passed
9860 			 * we will get a return of the rsm. For a non-sack
9861 			 * connection we will get the rsm returned if the
9862 			 * dupack value is 3 or more.
9863 			 */
9864 			cts = tcp_get_usecs(&tv);
9865 			rack->r_ctl.rc_resend = tcp_rack_output(rack->rc_tp, rack, cts);
9866 			if (rack->r_ctl.rc_resend != NULL) {
9867 				if (!IN_FASTRECOVERY(rack->rc_tp->t_flags)) {
9868 					rack_cong_signal(rack->rc_tp, CC_NDUPACK,
9869 							 rack->rc_tp->snd_una, __LINE__);
9870 				}
9871 				rack->r_wanted_output = 1;
9872 				rack->r_timer_override = 1;
9873 				rack_log_retran_reason(rack, rsm, __LINE__, 1, 3);
9874 			}
9875 		} else {
9876 			rack_log_retran_reason(rack, rsm, __LINE__, 0, 3);
9877 		}
9878 	}
9879 }
9880 
9881 static void
9882 rack_check_bottom_drag(struct tcpcb *tp,
9883 		       struct tcp_rack *rack,
9884 		       struct socket *so, int32_t acked)
9885 {
9886 	uint32_t segsiz, minseg;
9887 
9888 	segsiz = ctf_fixed_maxseg(tp);
9889 	minseg = segsiz;
9890 
9891 	if (tp->snd_max == tp->snd_una) {
9892 		/*
9893 		 * We are doing dynamic pacing and we are way
9894 		 * under. Basically everything got acked while
9895 		 * we were still waiting on the pacer to expire.
9896 		 *
9897 		 * This means we need to boost the b/w in
9898 		 * addition to any earlier boosting of
9899 		 * the multiplier.
9900 		 */
9901 		rack->rc_dragged_bottom = 1;
9902 		rack_validate_multipliers_at_or_above100(rack);
9903 		/*
9904 		 * Lets use the segment bytes acked plus
9905 		 * the lowest RTT seen as the basis to
9906 		 * form a b/w estimate. This will be off
9907 		 * due to the fact that the true estimate
9908 		 * should be around 1/2 the time of the RTT
9909 		 * but we can settle for that.
9910 		 */
9911 		if ((rack->r_ctl.rack_rs.rs_flags & RACK_RTT_VALID) &&
9912 		    acked) {
9913 			uint64_t bw, calc_bw, rtt;
9914 
9915 			rtt = rack->r_ctl.rack_rs.rs_us_rtt;
9916 			if (rtt == 0) {
9917 				/* no us sample is there a ms one? */
9918 				if (rack->r_ctl.rack_rs.rs_rtt_lowest) {
9919 					rtt = rack->r_ctl.rack_rs.rs_rtt_lowest;
9920 				} else {
9921 					goto no_measurement;
9922 				}
9923 			}
9924 			bw = acked;
9925 			calc_bw = bw * 1000000;
9926 			calc_bw /= rtt;
9927 			if (rack->r_ctl.last_max_bw &&
9928 			    (rack->r_ctl.last_max_bw < calc_bw)) {
9929 				/*
9930 				 * If we have a last calculated max bw
9931 				 * enforce it.
9932 				 */
9933 				calc_bw = rack->r_ctl.last_max_bw;
9934 			}
9935 			/* now plop it in */
9936 			if (rack->rc_gp_filled == 0) {
9937 				if (calc_bw > ONE_POINT_TWO_MEG) {
9938 					/*
9939 					 * If we have no measurement
9940 					 * don't let us set in more than
9941 					 * 1.2Mbps. If we are still too
9942 					 * low after pacing with this we
9943 					 * will hopefully have a max b/w
9944 					 * available to sanity check things.
9945 					 */
9946 					calc_bw = ONE_POINT_TWO_MEG;
9947 				}
9948 				rack->r_ctl.rc_rtt_diff = 0;
9949 				rack->r_ctl.gp_bw = calc_bw;
9950 				rack->rc_gp_filled = 1;
9951 				if (rack->r_ctl.num_measurements < RACK_REQ_AVG)
9952 					rack->r_ctl.num_measurements = RACK_REQ_AVG;
9953 				rack_set_pace_segments(rack->rc_tp, rack, __LINE__, NULL);
9954 			} else if (calc_bw > rack->r_ctl.gp_bw) {
9955 				rack->r_ctl.rc_rtt_diff = 0;
9956 				if (rack->r_ctl.num_measurements < RACK_REQ_AVG)
9957 					rack->r_ctl.num_measurements = RACK_REQ_AVG;
9958 				rack->r_ctl.gp_bw = calc_bw;
9959 				rack_set_pace_segments(rack->rc_tp, rack, __LINE__, NULL);
9960 			} else
9961 				rack_increase_bw_mul(rack, -1, 0, 0, 1);
9962 			if ((rack->gp_ready == 0) &&
9963 			    (rack->r_ctl.num_measurements >= rack->r_ctl.req_measurements)) {
9964 				/* We have enough measurements now */
9965 				rack->gp_ready = 1;
9966 				rack_set_cc_pacing(rack);
9967 				if (rack->defer_options)
9968 					rack_apply_deferred_options(rack);
9969 			}
9970 			/*
9971 			 * For acks over 1mss we do a extra boost to simulate
9972 			 * where we would get 2 acks (we want 110 for the mul).
9973 			 */
9974 			if (acked > segsiz)
9975 				rack_increase_bw_mul(rack, -1, 0, 0, 1);
9976 		} else {
9977 			/*
9978 			 * zero rtt possibly?, settle for just an old increase.
9979 			 */
9980 no_measurement:
9981 			rack_increase_bw_mul(rack, -1, 0, 0, 1);
9982 		}
9983 	} else if ((IN_FASTRECOVERY(tp->t_flags) == 0) &&
9984 		   (sbavail(&so->so_snd) > max((segsiz * (4 + rack_req_segs)),
9985 					       minseg)) &&
9986 		   (rack->r_ctl.cwnd_to_use > max((segsiz * (rack_req_segs + 2)), minseg)) &&
9987 		   (tp->snd_wnd > max((segsiz * (rack_req_segs + 2)), minseg)) &&
9988 		   (ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked) <=
9989 		    (segsiz * rack_req_segs))) {
9990 		/*
9991 		 * We are doing dynamic GP pacing and
9992 		 * we have everything except 1MSS or less
9993 		 * bytes left out. We are still pacing away.
9994 		 * And there is data that could be sent, This
9995 		 * means we are inserting delayed ack time in
9996 		 * our measurements because we are pacing too slow.
9997 		 */
9998 		rack_validate_multipliers_at_or_above100(rack);
9999 		rack->rc_dragged_bottom = 1;
10000 		rack_increase_bw_mul(rack, -1, 0, 0, 1);
10001 	}
10002 }
10003 
10004 
10005 
10006 static void
10007 rack_gain_for_fastoutput(struct tcp_rack *rack, struct tcpcb *tp, struct socket *so, uint32_t acked_amount)
10008 {
10009 	/*
10010 	 * The fast output path is enabled and we
10011 	 * have moved the cumack forward. Lets see if
10012 	 * we can expand forward the fast path length by
10013 	 * that amount. What we would ideally like to
10014 	 * do is increase the number of bytes in the
10015 	 * fast path block (left_to_send) by the
10016 	 * acked amount. However we have to gate that
10017 	 * by two factors:
10018 	 * 1) The amount outstanding and the rwnd of the peer
10019 	 *    (i.e. we don't want to exceed the rwnd of the peer).
10020 	 *    <and>
10021 	 * 2) The amount of data left in the socket buffer (i.e.
10022 	 *    we can't send beyond what is in the buffer).
10023 	 *
10024 	 * Note that this does not take into account any increase
10025 	 * in the cwnd. We will only extend the fast path by
10026 	 * what was acked.
10027 	 */
10028 	uint32_t new_total, gating_val;
10029 
10030 	new_total = acked_amount + rack->r_ctl.fsb.left_to_send;
10031 	gating_val = min((sbavail(&so->so_snd) - (tp->snd_max - tp->snd_una)),
10032 			 (tp->snd_wnd - (tp->snd_max - tp->snd_una)));
10033 	if (new_total <= gating_val) {
10034 		/* We can increase left_to_send by the acked amount */
10035 		counter_u64_add(rack_extended_rfo, 1);
10036 		rack->r_ctl.fsb.left_to_send = new_total;
10037 		KASSERT((rack->r_ctl.fsb.left_to_send <= (sbavail(&rack->rc_inp->inp_socket->so_snd) - (tp->snd_max - tp->snd_una))),
10038 			("rack:%p left_to_send:%u sbavail:%u out:%u",
10039 			 rack, rack->r_ctl.fsb.left_to_send,
10040 			 sbavail(&rack->rc_inp->inp_socket->so_snd),
10041 			 (tp->snd_max - tp->snd_una)));
10042 
10043 	}
10044 }
10045 
10046 static void
10047 rack_adjust_sendmap(struct tcp_rack *rack, struct sockbuf *sb, tcp_seq snd_una)
10048 {
10049 	/*
10050 	 * Here any sendmap entry that points to the
10051 	 * beginning mbuf must be adjusted to the correct
10052 	 * offset. This must be called with:
10053 	 * 1) The socket buffer locked
10054 	 * 2) snd_una adjusted to its new postion.
10055 	 *
10056 	 * Note that (2) implies rack_ack_received has also
10057 	 * been called.
10058 	 *
10059 	 * We grab the first mbuf in the socket buffer and
10060 	 * then go through the front of the sendmap, recalculating
10061 	 * the stored offset for any sendmap entry that has
10062 	 * that mbuf. We must use the sb functions to do this
10063 	 * since its possible an add was done has well as
10064 	 * the subtraction we may have just completed. This should
10065 	 * not be a penalty though, since we just referenced the sb
10066 	 * to go in and trim off the mbufs that we freed (of course
10067 	 * there will be a penalty for the sendmap references though).
10068 	 */
10069 	struct mbuf *m;
10070 	struct rack_sendmap *rsm;
10071 
10072 	SOCKBUF_LOCK_ASSERT(sb);
10073 	m = sb->sb_mb;
10074 	rsm = RB_MIN(rack_rb_tree_head, &rack->r_ctl.rc_mtree);
10075 	if ((rsm == NULL) || (m == NULL)) {
10076 		/* Nothing outstanding */
10077 		return;
10078 	}
10079 	while (rsm->m && (rsm->m == m)) {
10080 		/* one to adjust */
10081 #ifdef INVARIANTS
10082 		struct mbuf *tm;
10083 		uint32_t soff;
10084 
10085 		tm = sbsndmbuf(sb, (rsm->r_start - snd_una), &soff);
10086 		if (rsm->orig_m_len != m->m_len) {
10087 			rack_adjust_orig_mlen(rsm);
10088 		}
10089 		if (rsm->soff != soff) {
10090 			/*
10091 			 * This is not a fatal error, we anticipate it
10092 			 * might happen (the else code), so we count it here
10093 			 * so that under invariant we can see that it really
10094 			 * does happen.
10095 			 */
10096 			counter_u64_add(rack_adjust_map_bw, 1);
10097 		}
10098 		rsm->m = tm;
10099 		rsm->soff = soff;
10100 		if (tm)
10101 			rsm->orig_m_len = rsm->m->m_len;
10102 		else
10103 			rsm->orig_m_len = 0;
10104 #else
10105 		rsm->m = sbsndmbuf(sb, (rsm->r_start - snd_una), &rsm->soff);
10106 		if (rsm->m)
10107 			rsm->orig_m_len = rsm->m->m_len;
10108 		else
10109 			rsm->orig_m_len = 0;
10110 #endif
10111 		rsm = RB_NEXT(rack_rb_tree_head, &rack->r_ctl.rc_mtree,
10112 			      rsm);
10113 		if (rsm == NULL)
10114 			break;
10115 	}
10116 }
10117 
10118 /*
10119  * Return value of 1, we do not need to call rack_process_data().
10120  * return value of 0, rack_process_data can be called.
10121  * For ret_val if its 0 the TCP is locked, if its non-zero
10122  * its unlocked and probably unsafe to touch the TCB.
10123  */
10124 static int
10125 rack_process_ack(struct mbuf *m, struct tcphdr *th, struct socket *so,
10126     struct tcpcb *tp, struct tcpopt *to,
10127     uint32_t tiwin, int32_t tlen,
10128     int32_t * ofia, int32_t thflags, int32_t *ret_val)
10129 {
10130 	int32_t ourfinisacked = 0;
10131 	int32_t nsegs, acked_amount;
10132 	int32_t acked;
10133 	struct mbuf *mfree;
10134 	struct tcp_rack *rack;
10135 	int32_t under_pacing = 0;
10136 	int32_t recovery = 0;
10137 
10138 	INP_WLOCK_ASSERT(tptoinpcb(tp));
10139 
10140 	rack = (struct tcp_rack *)tp->t_fb_ptr;
10141 	if (SEQ_GT(th->th_ack, tp->snd_max)) {
10142 		__ctf_do_dropafterack(m, tp, th, thflags, tlen, ret_val,
10143 				      &rack->r_ctl.challenge_ack_ts,
10144 				      &rack->r_ctl.challenge_ack_cnt);
10145 		rack->r_wanted_output = 1;
10146 		return (1);
10147 	}
10148 	if (rack->gp_ready &&
10149 	    (rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT)) {
10150 		under_pacing = 1;
10151 	}
10152 	if (SEQ_GEQ(th->th_ack, tp->snd_una) || to->to_nsacks) {
10153 		int in_rec, dup_ack_struck = 0;
10154 
10155 		in_rec = IN_FASTRECOVERY(tp->t_flags);
10156 		if (rack->rc_in_persist) {
10157 			tp->t_rxtshift = 0;
10158 			RACK_TCPT_RANGESET(tp->t_rxtcur, RACK_REXMTVAL(tp),
10159 				      rack_rto_min, rack_rto_max, rack->r_ctl.timer_slop);
10160 		}
10161 		if ((th->th_ack == tp->snd_una) &&
10162 		    (tiwin == tp->snd_wnd) &&
10163 		    ((to->to_flags & TOF_SACK) == 0)) {
10164 			rack_strike_dupack(rack);
10165 			dup_ack_struck = 1;
10166 		}
10167 		rack_log_ack(tp, to, th, ((in_rec == 0) && IN_FASTRECOVERY(tp->t_flags)), dup_ack_struck);
10168 	}
10169 	if (__predict_false(SEQ_LEQ(th->th_ack, tp->snd_una))) {
10170 		/*
10171 		 * Old ack, behind (or duplicate to) the last one rcv'd
10172 		 * Note: We mark reordering is occuring if its
10173 		 * less than and we have not closed our window.
10174 		 */
10175 		if (SEQ_LT(th->th_ack, tp->snd_una) && (sbspace(&so->so_rcv) > ctf_fixed_maxseg(tp))) {
10176 			rack->r_ctl.rc_reorder_ts = tcp_tv_to_usectick(&rack->r_ctl.act_rcv_time);
10177 		}
10178 		return (0);
10179 	}
10180 	/*
10181 	 * If we reach this point, ACK is not a duplicate, i.e., it ACKs
10182 	 * something we sent.
10183 	 */
10184 	if (tp->t_flags & TF_NEEDSYN) {
10185 		/*
10186 		 * T/TCP: Connection was half-synchronized, and our SYN has
10187 		 * been ACK'd (so connection is now fully synchronized).  Go
10188 		 * to non-starred state, increment snd_una for ACK of SYN,
10189 		 * and check if we can do window scaling.
10190 		 */
10191 		tp->t_flags &= ~TF_NEEDSYN;
10192 		tp->snd_una++;
10193 		/* Do window scaling? */
10194 		if ((tp->t_flags & (TF_RCVD_SCALE | TF_REQ_SCALE)) ==
10195 		    (TF_RCVD_SCALE | TF_REQ_SCALE)) {
10196 			tp->rcv_scale = tp->request_r_scale;
10197 			/* Send window already scaled. */
10198 		}
10199 	}
10200 	nsegs = max(1, m->m_pkthdr.lro_nsegs);
10201 
10202 	acked = BYTES_THIS_ACK(tp, th);
10203 	if (acked) {
10204 		/*
10205 		 * Any time we move the cum-ack forward clear
10206 		 * keep-alive tied probe-not-answered. The
10207 		 * persists clears its own on entry.
10208 		 */
10209 		rack->probe_not_answered = 0;
10210 	}
10211 	KMOD_TCPSTAT_ADD(tcps_rcvackpack, nsegs);
10212 	KMOD_TCPSTAT_ADD(tcps_rcvackbyte, acked);
10213 	/*
10214 	 * If we just performed our first retransmit, and the ACK arrives
10215 	 * within our recovery window, then it was a mistake to do the
10216 	 * retransmit in the first place.  Recover our original cwnd and
10217 	 * ssthresh, and proceed to transmit where we left off.
10218 	 */
10219 	if ((tp->t_flags & TF_PREVVALID) &&
10220 	    ((tp->t_flags & TF_RCVD_TSTMP) == 0)) {
10221 		tp->t_flags &= ~TF_PREVVALID;
10222 		if (tp->t_rxtshift == 1 &&
10223 		    (int)(ticks - tp->t_badrxtwin) < 0)
10224 			rack_cong_signal(tp, CC_RTO_ERR, th->th_ack, __LINE__);
10225 	}
10226 	if (acked) {
10227 		/* assure we are not backed off */
10228 		tp->t_rxtshift = 0;
10229 		RACK_TCPT_RANGESET(tp->t_rxtcur, RACK_REXMTVAL(tp),
10230 			      rack_rto_min, rack_rto_max, rack->r_ctl.timer_slop);
10231 		rack->rc_tlp_in_progress = 0;
10232 		rack->r_ctl.rc_tlp_cnt_out = 0;
10233 		/*
10234 		 * If it is the RXT timer we want to
10235 		 * stop it, so we can restart a TLP.
10236 		 */
10237 		if (rack->r_ctl.rc_hpts_flags & PACE_TMR_RXT)
10238 			rack_timer_cancel(tp, rack, rack->r_ctl.rc_rcvtime, __LINE__);
10239 #ifdef NETFLIX_HTTP_LOGGING
10240 		tcp_http_check_for_comp(rack->rc_tp, th->th_ack);
10241 #endif
10242 	}
10243 	/*
10244 	 * If we have a timestamp reply, update smoothed round trip time. If
10245 	 * no timestamp is present but transmit timer is running and timed
10246 	 * sequence number was acked, update smoothed round trip time. Since
10247 	 * we now have an rtt measurement, cancel the timer backoff (cf.,
10248 	 * Phil Karn's retransmit alg.). Recompute the initial retransmit
10249 	 * timer.
10250 	 *
10251 	 * Some boxes send broken timestamp replies during the SYN+ACK
10252 	 * phase, ignore timestamps of 0 or we could calculate a huge RTT
10253 	 * and blow up the retransmit timer.
10254 	 */
10255 	/*
10256 	 * If all outstanding data is acked, stop retransmit timer and
10257 	 * remember to restart (more output or persist). If there is more
10258 	 * data to be acked, restart retransmit timer, using current
10259 	 * (possibly backed-off) value.
10260 	 */
10261 	if (acked == 0) {
10262 		if (ofia)
10263 			*ofia = ourfinisacked;
10264 		return (0);
10265 	}
10266 	if (IN_RECOVERY(tp->t_flags)) {
10267 		if (SEQ_LT(th->th_ack, tp->snd_recover) &&
10268 		    (SEQ_LT(th->th_ack, tp->snd_max))) {
10269 			tcp_rack_partialack(tp);
10270 		} else {
10271 			rack_post_recovery(tp, th->th_ack);
10272 			recovery = 1;
10273 		}
10274 	}
10275 	/*
10276 	 * Let the congestion control algorithm update congestion control
10277 	 * related information. This typically means increasing the
10278 	 * congestion window.
10279 	 */
10280 	rack_ack_received(tp, rack, th->th_ack, nsegs, CC_ACK, recovery);
10281 	SOCKBUF_LOCK(&so->so_snd);
10282 	acked_amount = min(acked, (int)sbavail(&so->so_snd));
10283 	tp->snd_wnd -= acked_amount;
10284 	mfree = sbcut_locked(&so->so_snd, acked_amount);
10285 	if ((sbused(&so->so_snd) == 0) &&
10286 	    (acked > acked_amount) &&
10287 	    (tp->t_state >= TCPS_FIN_WAIT_1) &&
10288 	    (tp->t_flags & TF_SENTFIN)) {
10289 		/*
10290 		 * We must be sure our fin
10291 		 * was sent and acked (we can be
10292 		 * in FIN_WAIT_1 without having
10293 		 * sent the fin).
10294 		 */
10295 		ourfinisacked = 1;
10296 	}
10297 	tp->snd_una = th->th_ack;
10298 	if (acked_amount && sbavail(&so->so_snd))
10299 		rack_adjust_sendmap(rack, &so->so_snd, tp->snd_una);
10300 	rack_log_wakeup(tp,rack, &so->so_snd, acked, 2);
10301 	/* NB: sowwakeup_locked() does an implicit unlock. */
10302 	sowwakeup_locked(so);
10303 	m_freem(mfree);
10304 	if (SEQ_GT(tp->snd_una, tp->snd_recover))
10305 		tp->snd_recover = tp->snd_una;
10306 
10307 	if (SEQ_LT(tp->snd_nxt, tp->snd_una)) {
10308 		tp->snd_nxt = tp->snd_una;
10309 	}
10310 	if (under_pacing &&
10311 	    (rack->use_fixed_rate == 0) &&
10312 	    (rack->in_probe_rtt == 0) &&
10313 	    rack->rc_gp_dyn_mul &&
10314 	    rack->rc_always_pace) {
10315 		/* Check if we are dragging bottom */
10316 		rack_check_bottom_drag(tp, rack, so, acked);
10317 	}
10318 	if (tp->snd_una == tp->snd_max) {
10319 		/* Nothing left outstanding */
10320 		tp->t_flags &= ~TF_PREVVALID;
10321 		rack->r_ctl.rc_went_idle_time = tcp_get_usecs(NULL);
10322 		rack->r_ctl.retran_during_recovery = 0;
10323 		rack->r_ctl.dsack_byte_cnt = 0;
10324 		if (rack->r_ctl.rc_went_idle_time == 0)
10325 			rack->r_ctl.rc_went_idle_time = 1;
10326 		rack_log_progress_event(rack, tp, 0, PROGRESS_CLEAR, __LINE__);
10327 		if (sbavail(&tptosocket(tp)->so_snd) == 0)
10328 			tp->t_acktime = 0;
10329 		rack_timer_cancel(tp, rack, rack->r_ctl.rc_rcvtime, __LINE__);
10330 		/* Set need output so persist might get set */
10331 		rack->r_wanted_output = 1;
10332 		sack_filter_clear(&rack->r_ctl.rack_sf, tp->snd_una);
10333 		if ((tp->t_state >= TCPS_FIN_WAIT_1) &&
10334 		    (sbavail(&so->so_snd) == 0) &&
10335 		    (tp->t_flags2 & TF2_DROP_AF_DATA)) {
10336 			/*
10337 			 * The socket was gone and the
10338 			 * peer sent data (now or in the past), time to
10339 			 * reset him.
10340 			 */
10341 			*ret_val = 1;
10342 			/* tcp_close will kill the inp pre-log the Reset */
10343 			tcp_log_end_status(tp, TCP_EI_STATUS_SERVER_RST);
10344 			tp = tcp_close(tp);
10345 			ctf_do_dropwithreset(m, tp, th, BANDLIM_UNLIMITED, tlen);
10346 			return (1);
10347 		}
10348 	}
10349 	if (ofia)
10350 		*ofia = ourfinisacked;
10351 	return (0);
10352 }
10353 
10354 
10355 static void
10356 rack_log_collapse(struct tcp_rack *rack, uint32_t cnt, uint32_t split, uint32_t out, int line,
10357 		  int dir, uint32_t flags, struct rack_sendmap *rsm)
10358 {
10359 	if (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
10360 		union tcp_log_stackspecific log;
10361 		struct timeval tv;
10362 
10363 		memset(&log, 0, sizeof(log));
10364 		log.u_bbr.flex1 = cnt;
10365 		log.u_bbr.flex2 = split;
10366 		log.u_bbr.flex3 = out;
10367 		log.u_bbr.flex4 = line;
10368 		log.u_bbr.flex5 = rack->r_must_retran;
10369 		log.u_bbr.flex6 = flags;
10370 		log.u_bbr.flex7 = rack->rc_has_collapsed;
10371 		log.u_bbr.flex8 = dir;	/*
10372 					 * 1 is collapsed, 0 is uncollapsed,
10373 					 * 2 is log of a rsm being marked, 3 is a split.
10374 					 */
10375 		if (rsm == NULL)
10376 			log.u_bbr.rttProp = 0;
10377 		else
10378 			log.u_bbr.rttProp = (uint64_t)rsm;
10379 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
10380 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
10381 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
10382 		    &rack->rc_inp->inp_socket->so_rcv,
10383 		    &rack->rc_inp->inp_socket->so_snd,
10384 		    TCP_RACK_LOG_COLLAPSE, 0,
10385 		    0, &log, false, &tv);
10386 	}
10387 }
10388 
10389 static void
10390 rack_collapsed_window(struct tcp_rack *rack, uint32_t out, int line)
10391 {
10392 	/*
10393 	 * Here all we do is mark the collapsed point and set the flag.
10394 	 * This may happen again and again, but there is no
10395 	 * sense splitting our map until we know where the
10396 	 * peer finally lands in the collapse.
10397 	 */
10398 	rack_trace_point(rack, RACK_TP_COLLAPSED_WND);
10399 	if ((rack->rc_has_collapsed == 0) ||
10400 	    (rack->r_ctl.last_collapse_point != (rack->rc_tp->snd_una + rack->rc_tp->snd_wnd)))
10401 		counter_u64_add(rack_collapsed_win_seen, 1);
10402 	rack->r_ctl.last_collapse_point = rack->rc_tp->snd_una + rack->rc_tp->snd_wnd;
10403 	rack->r_ctl.high_collapse_point = rack->rc_tp->snd_max;
10404 	rack->rc_has_collapsed = 1;
10405 	rack->r_collapse_point_valid = 1;
10406 	rack_log_collapse(rack, 0, 0, rack->r_ctl.last_collapse_point, line, 1, 0, NULL);
10407 }
10408 
10409 static void
10410 rack_un_collapse_window(struct tcp_rack *rack, int line)
10411 {
10412 	struct rack_sendmap *nrsm, *rsm, fe;
10413 	int cnt = 0, split = 0;
10414 #ifdef INVARIANTS
10415 	struct rack_sendmap *insret;
10416 #endif
10417 
10418 	memset(&fe, 0, sizeof(fe));
10419 	rack->rc_has_collapsed = 0;
10420 	fe.r_start = rack->r_ctl.last_collapse_point;
10421 	rsm = RB_FIND(rack_rb_tree_head, &rack->r_ctl.rc_mtree, &fe);
10422 	if (rsm == NULL) {
10423 		/* Nothing to do maybe the peer ack'ed it all */
10424 		rack_log_collapse(rack, 0, 0, ctf_outstanding(rack->rc_tp), line, 0, 0, NULL);
10425 		return;
10426 	}
10427 	/* Now do we need to split this one? */
10428 	if (SEQ_GT(rack->r_ctl.last_collapse_point, rsm->r_start)) {
10429 		rack_log_collapse(rack, rsm->r_start, rsm->r_end,
10430 				  rack->r_ctl.last_collapse_point, line, 3, rsm->r_flags, rsm);
10431 		nrsm = rack_alloc_limit(rack, RACK_LIMIT_TYPE_SPLIT);
10432 		if (nrsm == NULL) {
10433 			/* We can't get a rsm, mark all? */
10434 			nrsm = rsm;
10435 			goto no_split;
10436 		}
10437 		/* Clone it */
10438 		split = 1;
10439 		rack_clone_rsm(rack, nrsm, rsm, rack->r_ctl.last_collapse_point);
10440 #ifndef INVARIANTS
10441 		(void)RB_INSERT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, nrsm);
10442 #else
10443 		insret = RB_INSERT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, nrsm);
10444 		if (insret != NULL) {
10445 			panic("Insert in rb tree of %p fails ret:%p rack:%p rsm:%p",
10446 			      nrsm, insret, rack, rsm);
10447 		}
10448 #endif
10449 		rack_log_map_chg(rack->rc_tp, rack, NULL, rsm, nrsm, MAP_SPLIT,
10450 				 rack->r_ctl.last_collapse_point, __LINE__);
10451 		if (rsm->r_in_tmap) {
10452 			TAILQ_INSERT_AFTER(&rack->r_ctl.rc_tmap, rsm, nrsm, r_tnext);
10453 			nrsm->r_in_tmap = 1;
10454 		}
10455 		/*
10456 		 * Set in the new RSM as the
10457 		 * collapsed starting point
10458 		 */
10459 		rsm = nrsm;
10460 	}
10461 no_split:
10462 	RB_FOREACH_FROM(nrsm, rack_rb_tree_head, rsm) {
10463 		nrsm->r_flags |= RACK_RWND_COLLAPSED;
10464 		rack_log_collapse(rack, nrsm->r_start, nrsm->r_end, 0, line, 4, nrsm->r_flags, nrsm);
10465 		cnt++;
10466 	}
10467 	if (cnt) {
10468 		counter_u64_add(rack_collapsed_win, 1);
10469 	}
10470 	rack_log_collapse(rack, cnt, split, ctf_outstanding(rack->rc_tp), line, 0, 0, NULL);
10471 }
10472 
10473 static void
10474 rack_handle_delayed_ack(struct tcpcb *tp, struct tcp_rack *rack,
10475 			int32_t tlen, int32_t tfo_syn)
10476 {
10477 	if (DELAY_ACK(tp, tlen) || tfo_syn) {
10478 		if (rack->rc_dack_mode &&
10479 		    (tlen > 500) &&
10480 		    (rack->rc_dack_toggle == 1)) {
10481 			goto no_delayed_ack;
10482 		}
10483 		rack_timer_cancel(tp, rack,
10484 				  rack->r_ctl.rc_rcvtime, __LINE__);
10485 		tp->t_flags |= TF_DELACK;
10486 	} else {
10487 no_delayed_ack:
10488 		rack->r_wanted_output = 1;
10489 		tp->t_flags |= TF_ACKNOW;
10490 		if (rack->rc_dack_mode) {
10491 			if (tp->t_flags & TF_DELACK)
10492 				rack->rc_dack_toggle = 1;
10493 			else
10494 				rack->rc_dack_toggle = 0;
10495 		}
10496 	}
10497 }
10498 
10499 static void
10500 rack_validate_fo_sendwin_up(struct tcpcb *tp, struct tcp_rack *rack)
10501 {
10502 	/*
10503 	 * If fast output is in progress, lets validate that
10504 	 * the new window did not shrink on us and make it
10505 	 * so fast output should end.
10506 	 */
10507 	if (rack->r_fast_output) {
10508 		uint32_t out;
10509 
10510 		/*
10511 		 * Calculate what we will send if left as is
10512 		 * and compare that to our send window.
10513 		 */
10514 		out = ctf_outstanding(tp);
10515 		if ((out + rack->r_ctl.fsb.left_to_send) > tp->snd_wnd) {
10516 			/* ok we have an issue */
10517 			if (out >= tp->snd_wnd) {
10518 				/* Turn off fast output the window is met or collapsed */
10519 				rack->r_fast_output = 0;
10520 			} else {
10521 				/* we have some room left */
10522 				rack->r_ctl.fsb.left_to_send = tp->snd_wnd - out;
10523 				if (rack->r_ctl.fsb.left_to_send < ctf_fixed_maxseg(tp)) {
10524 					/* If not at least 1 full segment never mind */
10525 					rack->r_fast_output = 0;
10526 				}
10527 			}
10528 		}
10529 	}
10530 }
10531 
10532 
10533 /*
10534  * Return value of 1, the TCB is unlocked and most
10535  * likely gone, return value of 0, the TCP is still
10536  * locked.
10537  */
10538 static int
10539 rack_process_data(struct mbuf *m, struct tcphdr *th, struct socket *so,
10540     struct tcpcb *tp, int32_t drop_hdrlen, int32_t tlen,
10541     uint32_t tiwin, int32_t thflags, int32_t nxt_pkt)
10542 {
10543 	/*
10544 	 * Update window information. Don't look at window if no ACK: TAC's
10545 	 * send garbage on first SYN.
10546 	 */
10547 	int32_t nsegs;
10548 	int32_t tfo_syn;
10549 	struct tcp_rack *rack;
10550 
10551 	INP_WLOCK_ASSERT(tptoinpcb(tp));
10552 
10553 	rack = (struct tcp_rack *)tp->t_fb_ptr;
10554 	nsegs = max(1, m->m_pkthdr.lro_nsegs);
10555 	if ((thflags & TH_ACK) &&
10556 	    (SEQ_LT(tp->snd_wl1, th->th_seq) ||
10557 	    (tp->snd_wl1 == th->th_seq && (SEQ_LT(tp->snd_wl2, th->th_ack) ||
10558 	    (tp->snd_wl2 == th->th_ack && tiwin > tp->snd_wnd))))) {
10559 		/* keep track of pure window updates */
10560 		if (tlen == 0 &&
10561 		    tp->snd_wl2 == th->th_ack && tiwin > tp->snd_wnd)
10562 			KMOD_TCPSTAT_INC(tcps_rcvwinupd);
10563 		tp->snd_wnd = tiwin;
10564 		rack_validate_fo_sendwin_up(tp, rack);
10565 		tp->snd_wl1 = th->th_seq;
10566 		tp->snd_wl2 = th->th_ack;
10567 		if (tp->snd_wnd > tp->max_sndwnd)
10568 			tp->max_sndwnd = tp->snd_wnd;
10569 		rack->r_wanted_output = 1;
10570 	} else if (thflags & TH_ACK) {
10571 		if ((tp->snd_wl2 == th->th_ack) && (tiwin < tp->snd_wnd)) {
10572 			tp->snd_wnd = tiwin;
10573 			rack_validate_fo_sendwin_up(tp, rack);
10574 			tp->snd_wl1 = th->th_seq;
10575 			tp->snd_wl2 = th->th_ack;
10576 		}
10577 	}
10578 	if (tp->snd_wnd < ctf_outstanding(tp))
10579 		/* The peer collapsed the window */
10580 		rack_collapsed_window(rack, ctf_outstanding(tp), __LINE__);
10581 	else if (rack->rc_has_collapsed)
10582 		rack_un_collapse_window(rack, __LINE__);
10583 	if ((rack->r_collapse_point_valid) &&
10584 	    (SEQ_GT(th->th_ack, rack->r_ctl.high_collapse_point)))
10585 		rack->r_collapse_point_valid = 0;
10586 	/* Was persist timer active and now we have window space? */
10587 	if ((rack->rc_in_persist != 0) &&
10588 	    (tp->snd_wnd >= min((rack->r_ctl.rc_high_rwnd/2),
10589 				rack->r_ctl.rc_pace_min_segs))) {
10590 		rack_exit_persist(tp, rack, rack->r_ctl.rc_rcvtime);
10591 		tp->snd_nxt = tp->snd_max;
10592 		/* Make sure we output to start the timer */
10593 		rack->r_wanted_output = 1;
10594 	}
10595 	/* Do we enter persists? */
10596 	if ((rack->rc_in_persist == 0) &&
10597 	    (tp->snd_wnd < min((rack->r_ctl.rc_high_rwnd/2), rack->r_ctl.rc_pace_min_segs)) &&
10598 	    TCPS_HAVEESTABLISHED(tp->t_state) &&
10599 	    ((tp->snd_max == tp->snd_una) || rack->rc_has_collapsed) &&
10600 	    sbavail(&tptosocket(tp)->so_snd) &&
10601 	    (sbavail(&tptosocket(tp)->so_snd) > tp->snd_wnd)) {
10602 		/*
10603 		 * Here the rwnd is less than
10604 		 * the pacing size, we are established,
10605 		 * nothing is outstanding, and there is
10606 		 * data to send. Enter persists.
10607 		 */
10608 		rack_enter_persist(tp, rack, rack->r_ctl.rc_rcvtime);
10609 	}
10610 	if (tp->t_flags2 & TF2_DROP_AF_DATA) {
10611 		m_freem(m);
10612 		return (0);
10613 	}
10614 	/*
10615 	 * don't process the URG bit, ignore them drag
10616 	 * along the up.
10617 	 */
10618 	tp->rcv_up = tp->rcv_nxt;
10619 
10620 	/*
10621 	 * Process the segment text, merging it into the TCP sequencing
10622 	 * queue, and arranging for acknowledgment of receipt if necessary.
10623 	 * This process logically involves adjusting tp->rcv_wnd as data is
10624 	 * presented to the user (this happens in tcp_usrreq.c, case
10625 	 * PRU_RCVD).  If a FIN has already been received on this connection
10626 	 * then we just ignore the text.
10627 	 */
10628 	tfo_syn = ((tp->t_state == TCPS_SYN_RECEIVED) &&
10629 		   IS_FASTOPEN(tp->t_flags));
10630 	if ((tlen || (thflags & TH_FIN) || (tfo_syn && tlen > 0)) &&
10631 	    TCPS_HAVERCVDFIN(tp->t_state) == 0) {
10632 		tcp_seq save_start = th->th_seq;
10633 		tcp_seq save_rnxt  = tp->rcv_nxt;
10634 		int     save_tlen  = tlen;
10635 
10636 		m_adj(m, drop_hdrlen);	/* delayed header drop */
10637 		/*
10638 		 * Insert segment which includes th into TCP reassembly
10639 		 * queue with control block tp.  Set thflags to whether
10640 		 * reassembly now includes a segment with FIN.  This handles
10641 		 * the common case inline (segment is the next to be
10642 		 * received on an established connection, and the queue is
10643 		 * empty), avoiding linkage into and removal from the queue
10644 		 * and repetition of various conversions. Set DELACK for
10645 		 * segments received in order, but ack immediately when
10646 		 * segments are out of order (so fast retransmit can work).
10647 		 */
10648 		if (th->th_seq == tp->rcv_nxt &&
10649 		    SEGQ_EMPTY(tp) &&
10650 		    (TCPS_HAVEESTABLISHED(tp->t_state) ||
10651 		    tfo_syn)) {
10652 #ifdef NETFLIX_SB_LIMITS
10653 			u_int mcnt, appended;
10654 
10655 			if (so->so_rcv.sb_shlim) {
10656 				mcnt = m_memcnt(m);
10657 				appended = 0;
10658 				if (counter_fo_get(so->so_rcv.sb_shlim, mcnt,
10659 				    CFO_NOSLEEP, NULL) == false) {
10660 					counter_u64_add(tcp_sb_shlim_fails, 1);
10661 					m_freem(m);
10662 					return (0);
10663 				}
10664 			}
10665 #endif
10666 			rack_handle_delayed_ack(tp, rack, tlen, tfo_syn);
10667 			tp->rcv_nxt += tlen;
10668 			if (tlen &&
10669 			    ((tp->t_flags2 & TF2_FBYTES_COMPLETE) == 0) &&
10670 			    (tp->t_fbyte_in == 0)) {
10671 				tp->t_fbyte_in = ticks;
10672 				if (tp->t_fbyte_in == 0)
10673 					tp->t_fbyte_in = 1;
10674 				if (tp->t_fbyte_out && tp->t_fbyte_in)
10675 					tp->t_flags2 |= TF2_FBYTES_COMPLETE;
10676 			}
10677 			thflags = tcp_get_flags(th) & TH_FIN;
10678 			KMOD_TCPSTAT_ADD(tcps_rcvpack, nsegs);
10679 			KMOD_TCPSTAT_ADD(tcps_rcvbyte, tlen);
10680 			SOCKBUF_LOCK(&so->so_rcv);
10681 			if (so->so_rcv.sb_state & SBS_CANTRCVMORE) {
10682 				m_freem(m);
10683 			} else
10684 #ifdef NETFLIX_SB_LIMITS
10685 				appended =
10686 #endif
10687 					sbappendstream_locked(&so->so_rcv, m, 0);
10688 
10689 			rack_log_wakeup(tp,rack, &so->so_rcv, tlen, 1);
10690 			/* NB: sorwakeup_locked() does an implicit unlock. */
10691 			sorwakeup_locked(so);
10692 #ifdef NETFLIX_SB_LIMITS
10693 			if (so->so_rcv.sb_shlim && appended != mcnt)
10694 				counter_fo_release(so->so_rcv.sb_shlim,
10695 				    mcnt - appended);
10696 #endif
10697 		} else {
10698 			/*
10699 			 * XXX: Due to the header drop above "th" is
10700 			 * theoretically invalid by now.  Fortunately
10701 			 * m_adj() doesn't actually frees any mbufs when
10702 			 * trimming from the head.
10703 			 */
10704 			tcp_seq temp = save_start;
10705 
10706 			thflags = tcp_reass(tp, th, &temp, &tlen, m);
10707 			tp->t_flags |= TF_ACKNOW;
10708 			if (tp->t_flags & TF_WAKESOR) {
10709 				tp->t_flags &= ~TF_WAKESOR;
10710 				/* NB: sorwakeup_locked() does an implicit unlock. */
10711 				sorwakeup_locked(so);
10712 			}
10713 		}
10714 		if ((tp->t_flags & TF_SACK_PERMIT) &&
10715 		    (save_tlen > 0) &&
10716 		    TCPS_HAVEESTABLISHED(tp->t_state)) {
10717 			if ((tlen == 0) && (SEQ_LT(save_start, save_rnxt))) {
10718 				/*
10719 				 * DSACK actually handled in the fastpath
10720 				 * above.
10721 				 */
10722 				RACK_OPTS_INC(tcp_sack_path_1);
10723 				tcp_update_sack_list(tp, save_start,
10724 				    save_start + save_tlen);
10725 			} else if ((tlen > 0) && SEQ_GT(tp->rcv_nxt, save_rnxt)) {
10726 				if ((tp->rcv_numsacks >= 1) &&
10727 				    (tp->sackblks[0].end == save_start)) {
10728 					/*
10729 					 * Partial overlap, recorded at todrop
10730 					 * above.
10731 					 */
10732 					RACK_OPTS_INC(tcp_sack_path_2a);
10733 					tcp_update_sack_list(tp,
10734 					    tp->sackblks[0].start,
10735 					    tp->sackblks[0].end);
10736 				} else {
10737 					RACK_OPTS_INC(tcp_sack_path_2b);
10738 					tcp_update_dsack_list(tp, save_start,
10739 					    save_start + save_tlen);
10740 				}
10741 			} else if (tlen >= save_tlen) {
10742 				/* Update of sackblks. */
10743 				RACK_OPTS_INC(tcp_sack_path_3);
10744 				tcp_update_dsack_list(tp, save_start,
10745 				    save_start + save_tlen);
10746 			} else if (tlen > 0) {
10747 				RACK_OPTS_INC(tcp_sack_path_4);
10748 				tcp_update_dsack_list(tp, save_start,
10749 				    save_start + tlen);
10750 			}
10751 		}
10752 	} else {
10753 		m_freem(m);
10754 		thflags &= ~TH_FIN;
10755 	}
10756 
10757 	/*
10758 	 * If FIN is received ACK the FIN and let the user know that the
10759 	 * connection is closing.
10760 	 */
10761 	if (thflags & TH_FIN) {
10762 		if (TCPS_HAVERCVDFIN(tp->t_state) == 0) {
10763 			/* The socket upcall is handled by socantrcvmore. */
10764 			socantrcvmore(so);
10765 			/*
10766 			 * If connection is half-synchronized (ie NEEDSYN
10767 			 * flag on) then delay ACK, so it may be piggybacked
10768 			 * when SYN is sent. Otherwise, since we received a
10769 			 * FIN then no more input can be expected, send ACK
10770 			 * now.
10771 			 */
10772 			if (tp->t_flags & TF_NEEDSYN) {
10773 				rack_timer_cancel(tp, rack,
10774 				    rack->r_ctl.rc_rcvtime, __LINE__);
10775 				tp->t_flags |= TF_DELACK;
10776 			} else {
10777 				tp->t_flags |= TF_ACKNOW;
10778 			}
10779 			tp->rcv_nxt++;
10780 		}
10781 		switch (tp->t_state) {
10782 			/*
10783 			 * In SYN_RECEIVED and ESTABLISHED STATES enter the
10784 			 * CLOSE_WAIT state.
10785 			 */
10786 		case TCPS_SYN_RECEIVED:
10787 			tp->t_starttime = ticks;
10788 			/* FALLTHROUGH */
10789 		case TCPS_ESTABLISHED:
10790 			rack_timer_cancel(tp, rack,
10791 			    rack->r_ctl.rc_rcvtime, __LINE__);
10792 			tcp_state_change(tp, TCPS_CLOSE_WAIT);
10793 			break;
10794 
10795 			/*
10796 			 * If still in FIN_WAIT_1 STATE FIN has not been
10797 			 * acked so enter the CLOSING state.
10798 			 */
10799 		case TCPS_FIN_WAIT_1:
10800 			rack_timer_cancel(tp, rack,
10801 			    rack->r_ctl.rc_rcvtime, __LINE__);
10802 			tcp_state_change(tp, TCPS_CLOSING);
10803 			break;
10804 
10805 			/*
10806 			 * In FIN_WAIT_2 state enter the TIME_WAIT state,
10807 			 * starting the time-wait timer, turning off the
10808 			 * other standard timers.
10809 			 */
10810 		case TCPS_FIN_WAIT_2:
10811 			rack_timer_cancel(tp, rack,
10812 			    rack->r_ctl.rc_rcvtime, __LINE__);
10813 			tcp_twstart(tp);
10814 			return (1);
10815 		}
10816 	}
10817 	/*
10818 	 * Return any desired output.
10819 	 */
10820 	if ((tp->t_flags & TF_ACKNOW) ||
10821 	    (sbavail(&so->so_snd) > (tp->snd_max - tp->snd_una))) {
10822 		rack->r_wanted_output = 1;
10823 	}
10824 	return (0);
10825 }
10826 
10827 /*
10828  * Here nothing is really faster, its just that we
10829  * have broken out the fast-data path also just like
10830  * the fast-ack.
10831  */
10832 static int
10833 rack_do_fastnewdata(struct mbuf *m, struct tcphdr *th, struct socket *so,
10834     struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen,
10835     uint32_t tiwin, int32_t nxt_pkt, uint8_t iptos)
10836 {
10837 	int32_t nsegs;
10838 	int32_t newsize = 0;	/* automatic sockbuf scaling */
10839 	struct tcp_rack *rack;
10840 #ifdef NETFLIX_SB_LIMITS
10841 	u_int mcnt, appended;
10842 #endif
10843 #ifdef TCPDEBUG
10844 	/*
10845 	 * The size of tcp_saveipgen must be the size of the max ip header,
10846 	 * now IPv6.
10847 	 */
10848 	u_char tcp_saveipgen[IP6_HDR_LEN];
10849 	struct tcphdr tcp_savetcp;
10850 	short ostate = 0;
10851 
10852 #endif
10853 	/*
10854 	 * If last ACK falls within this segment's sequence numbers, record
10855 	 * the timestamp. NOTE that the test is modified according to the
10856 	 * latest proposal of the tcplw@cray.com list (Braden 1993/04/26).
10857 	 */
10858 	if (__predict_false(th->th_seq != tp->rcv_nxt)) {
10859 		return (0);
10860 	}
10861 	if (__predict_false(tp->snd_nxt != tp->snd_max)) {
10862 		return (0);
10863 	}
10864 	if (tiwin && tiwin != tp->snd_wnd) {
10865 		return (0);
10866 	}
10867 	if (__predict_false((tp->t_flags & (TF_NEEDSYN | TF_NEEDFIN)))) {
10868 		return (0);
10869 	}
10870 	if (__predict_false((to->to_flags & TOF_TS) &&
10871 	    (TSTMP_LT(to->to_tsval, tp->ts_recent)))) {
10872 		return (0);
10873 	}
10874 	if (__predict_false((th->th_ack != tp->snd_una))) {
10875 		return (0);
10876 	}
10877 	if (__predict_false(tlen > sbspace(&so->so_rcv))) {
10878 		return (0);
10879 	}
10880 	if ((to->to_flags & TOF_TS) != 0 &&
10881 	    SEQ_LEQ(th->th_seq, tp->last_ack_sent)) {
10882 		tp->ts_recent_age = tcp_ts_getticks();
10883 		tp->ts_recent = to->to_tsval;
10884 	}
10885 	rack = (struct tcp_rack *)tp->t_fb_ptr;
10886 	/*
10887 	 * This is a pure, in-sequence data packet with nothing on the
10888 	 * reassembly queue and we have enough buffer space to take it.
10889 	 */
10890 	nsegs = max(1, m->m_pkthdr.lro_nsegs);
10891 
10892 #ifdef NETFLIX_SB_LIMITS
10893 	if (so->so_rcv.sb_shlim) {
10894 		mcnt = m_memcnt(m);
10895 		appended = 0;
10896 		if (counter_fo_get(so->so_rcv.sb_shlim, mcnt,
10897 		    CFO_NOSLEEP, NULL) == false) {
10898 			counter_u64_add(tcp_sb_shlim_fails, 1);
10899 			m_freem(m);
10900 			return (1);
10901 		}
10902 	}
10903 #endif
10904 	/* Clean receiver SACK report if present */
10905 	if (tp->rcv_numsacks)
10906 		tcp_clean_sackreport(tp);
10907 	KMOD_TCPSTAT_INC(tcps_preddat);
10908 	tp->rcv_nxt += tlen;
10909 	if (tlen &&
10910 	    ((tp->t_flags2 & TF2_FBYTES_COMPLETE) == 0) &&
10911 	    (tp->t_fbyte_in == 0)) {
10912 		tp->t_fbyte_in = ticks;
10913 		if (tp->t_fbyte_in == 0)
10914 			tp->t_fbyte_in = 1;
10915 		if (tp->t_fbyte_out && tp->t_fbyte_in)
10916 			tp->t_flags2 |= TF2_FBYTES_COMPLETE;
10917 	}
10918 	/*
10919 	 * Pull snd_wl1 up to prevent seq wrap relative to th_seq.
10920 	 */
10921 	tp->snd_wl1 = th->th_seq;
10922 	/*
10923 	 * Pull rcv_up up to prevent seq wrap relative to rcv_nxt.
10924 	 */
10925 	tp->rcv_up = tp->rcv_nxt;
10926 	KMOD_TCPSTAT_ADD(tcps_rcvpack, nsegs);
10927 	KMOD_TCPSTAT_ADD(tcps_rcvbyte, tlen);
10928 #ifdef TCPDEBUG
10929 	if (so->so_options & SO_DEBUG)
10930 		tcp_trace(TA_INPUT, ostate, tp,
10931 		    (void *)tcp_saveipgen, &tcp_savetcp, 0);
10932 #endif
10933 	newsize = tcp_autorcvbuf(m, th, so, tp, tlen);
10934 
10935 	/* Add data to socket buffer. */
10936 	SOCKBUF_LOCK(&so->so_rcv);
10937 	if (so->so_rcv.sb_state & SBS_CANTRCVMORE) {
10938 		m_freem(m);
10939 	} else {
10940 		/*
10941 		 * Set new socket buffer size. Give up when limit is
10942 		 * reached.
10943 		 */
10944 		if (newsize)
10945 			if (!sbreserve_locked(so, SO_RCV, newsize, NULL))
10946 				so->so_rcv.sb_flags &= ~SB_AUTOSIZE;
10947 		m_adj(m, drop_hdrlen);	/* delayed header drop */
10948 #ifdef NETFLIX_SB_LIMITS
10949 		appended =
10950 #endif
10951 			sbappendstream_locked(&so->so_rcv, m, 0);
10952 		ctf_calc_rwin(so, tp);
10953 	}
10954 	rack_log_wakeup(tp,rack, &so->so_rcv, tlen, 1);
10955 	/* NB: sorwakeup_locked() does an implicit unlock. */
10956 	sorwakeup_locked(so);
10957 #ifdef NETFLIX_SB_LIMITS
10958 	if (so->so_rcv.sb_shlim && mcnt != appended)
10959 		counter_fo_release(so->so_rcv.sb_shlim, mcnt - appended);
10960 #endif
10961 	rack_handle_delayed_ack(tp, rack, tlen, 0);
10962 	if (tp->snd_una == tp->snd_max)
10963 		sack_filter_clear(&rack->r_ctl.rack_sf, tp->snd_una);
10964 	return (1);
10965 }
10966 
10967 /*
10968  * This subfunction is used to try to highly optimize the
10969  * fast path. We again allow window updates that are
10970  * in sequence to remain in the fast-path. We also add
10971  * in the __predict's to attempt to help the compiler.
10972  * Note that if we return a 0, then we can *not* process
10973  * it and the caller should push the packet into the
10974  * slow-path.
10975  */
10976 static int
10977 rack_fastack(struct mbuf *m, struct tcphdr *th, struct socket *so,
10978     struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen,
10979     uint32_t tiwin, int32_t nxt_pkt, uint32_t cts)
10980 {
10981 	int32_t acked;
10982 	int32_t nsegs;
10983 #ifdef TCPDEBUG
10984 	/*
10985 	 * The size of tcp_saveipgen must be the size of the max ip header,
10986 	 * now IPv6.
10987 	 */
10988 	u_char tcp_saveipgen[IP6_HDR_LEN];
10989 	struct tcphdr tcp_savetcp;
10990 	short ostate = 0;
10991 #endif
10992 	int32_t under_pacing = 0;
10993 	struct tcp_rack *rack;
10994 
10995 	if (__predict_false(SEQ_LEQ(th->th_ack, tp->snd_una))) {
10996 		/* Old ack, behind (or duplicate to) the last one rcv'd */
10997 		return (0);
10998 	}
10999 	if (__predict_false(SEQ_GT(th->th_ack, tp->snd_max))) {
11000 		/* Above what we have sent? */
11001 		return (0);
11002 	}
11003 	if (__predict_false(tp->snd_nxt != tp->snd_max)) {
11004 		/* We are retransmitting */
11005 		return (0);
11006 	}
11007 	if (__predict_false(tiwin == 0)) {
11008 		/* zero window */
11009 		return (0);
11010 	}
11011 	if (__predict_false(tp->t_flags & (TF_NEEDSYN | TF_NEEDFIN))) {
11012 		/* We need a SYN or a FIN, unlikely.. */
11013 		return (0);
11014 	}
11015 	if ((to->to_flags & TOF_TS) && __predict_false(TSTMP_LT(to->to_tsval, tp->ts_recent))) {
11016 		/* Timestamp is behind .. old ack with seq wrap? */
11017 		return (0);
11018 	}
11019 	if (__predict_false(IN_RECOVERY(tp->t_flags))) {
11020 		/* Still recovering */
11021 		return (0);
11022 	}
11023 	rack = (struct tcp_rack *)tp->t_fb_ptr;
11024 	if (rack->r_ctl.rc_sacked) {
11025 		/* We have sack holes on our scoreboard */
11026 		return (0);
11027 	}
11028 	/* Ok if we reach here, we can process a fast-ack */
11029 	if (rack->gp_ready &&
11030 	    (rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT)) {
11031 		under_pacing = 1;
11032 	}
11033 	nsegs = max(1, m->m_pkthdr.lro_nsegs);
11034 	rack_log_ack(tp, to, th, 0, 0);
11035 	/* Did the window get updated? */
11036 	if (tiwin != tp->snd_wnd) {
11037 		tp->snd_wnd = tiwin;
11038 		rack_validate_fo_sendwin_up(tp, rack);
11039 		tp->snd_wl1 = th->th_seq;
11040 		if (tp->snd_wnd > tp->max_sndwnd)
11041 			tp->max_sndwnd = tp->snd_wnd;
11042 	}
11043 	/* Do we exit persists? */
11044 	if ((rack->rc_in_persist != 0) &&
11045 	    (tp->snd_wnd >= min((rack->r_ctl.rc_high_rwnd/2),
11046 			       rack->r_ctl.rc_pace_min_segs))) {
11047 		rack_exit_persist(tp, rack, cts);
11048 	}
11049 	/* Do we enter persists? */
11050 	if ((rack->rc_in_persist == 0) &&
11051 	    (tp->snd_wnd < min((rack->r_ctl.rc_high_rwnd/2), rack->r_ctl.rc_pace_min_segs)) &&
11052 	    TCPS_HAVEESTABLISHED(tp->t_state) &&
11053 	    ((tp->snd_max == tp->snd_una) || rack->rc_has_collapsed) &&
11054 	    sbavail(&tptosocket(tp)->so_snd) &&
11055 	    (sbavail(&tptosocket(tp)->so_snd) > tp->snd_wnd)) {
11056 		/*
11057 		 * Here the rwnd is less than
11058 		 * the pacing size, we are established,
11059 		 * nothing is outstanding, and there is
11060 		 * data to send. Enter persists.
11061 		 */
11062 		rack_enter_persist(tp, rack, rack->r_ctl.rc_rcvtime);
11063 	}
11064 	/*
11065 	 * If last ACK falls within this segment's sequence numbers, record
11066 	 * the timestamp. NOTE that the test is modified according to the
11067 	 * latest proposal of the tcplw@cray.com list (Braden 1993/04/26).
11068 	 */
11069 	if ((to->to_flags & TOF_TS) != 0 &&
11070 	    SEQ_LEQ(th->th_seq, tp->last_ack_sent)) {
11071 		tp->ts_recent_age = tcp_ts_getticks();
11072 		tp->ts_recent = to->to_tsval;
11073 	}
11074 	/*
11075 	 * This is a pure ack for outstanding data.
11076 	 */
11077 	KMOD_TCPSTAT_INC(tcps_predack);
11078 
11079 	/*
11080 	 * "bad retransmit" recovery.
11081 	 */
11082 	if ((tp->t_flags & TF_PREVVALID) &&
11083 	    ((tp->t_flags & TF_RCVD_TSTMP) == 0)) {
11084 		tp->t_flags &= ~TF_PREVVALID;
11085 		if (tp->t_rxtshift == 1 &&
11086 		    (int)(ticks - tp->t_badrxtwin) < 0)
11087 			rack_cong_signal(tp, CC_RTO_ERR, th->th_ack, __LINE__);
11088 	}
11089 	/*
11090 	 * Recalculate the transmit timer / rtt.
11091 	 *
11092 	 * Some boxes send broken timestamp replies during the SYN+ACK
11093 	 * phase, ignore timestamps of 0 or we could calculate a huge RTT
11094 	 * and blow up the retransmit timer.
11095 	 */
11096 	acked = BYTES_THIS_ACK(tp, th);
11097 
11098 #ifdef TCP_HHOOK
11099 	/* Run HHOOK_TCP_ESTABLISHED_IN helper hooks. */
11100 	hhook_run_tcp_est_in(tp, th, to);
11101 #endif
11102 	KMOD_TCPSTAT_ADD(tcps_rcvackpack, nsegs);
11103 	KMOD_TCPSTAT_ADD(tcps_rcvackbyte, acked);
11104 	if (acked) {
11105 		struct mbuf *mfree;
11106 
11107 		rack_ack_received(tp, rack, th->th_ack, nsegs, CC_ACK, 0);
11108 		SOCKBUF_LOCK(&so->so_snd);
11109 		mfree = sbcut_locked(&so->so_snd, acked);
11110 		tp->snd_una = th->th_ack;
11111 		/* Note we want to hold the sb lock through the sendmap adjust */
11112 		rack_adjust_sendmap(rack, &so->so_snd, tp->snd_una);
11113 		/* Wake up the socket if we have room to write more */
11114 		rack_log_wakeup(tp,rack, &so->so_snd, acked, 2);
11115 		sowwakeup_locked(so);
11116 		m_freem(mfree);
11117 		tp->t_rxtshift = 0;
11118 		RACK_TCPT_RANGESET(tp->t_rxtcur, RACK_REXMTVAL(tp),
11119 			      rack_rto_min, rack_rto_max, rack->r_ctl.timer_slop);
11120 		rack->rc_tlp_in_progress = 0;
11121 		rack->r_ctl.rc_tlp_cnt_out = 0;
11122 		/*
11123 		 * If it is the RXT timer we want to
11124 		 * stop it, so we can restart a TLP.
11125 		 */
11126 		if (rack->r_ctl.rc_hpts_flags & PACE_TMR_RXT)
11127 			rack_timer_cancel(tp, rack, rack->r_ctl.rc_rcvtime, __LINE__);
11128 #ifdef NETFLIX_HTTP_LOGGING
11129 		tcp_http_check_for_comp(rack->rc_tp, th->th_ack);
11130 #endif
11131 	}
11132 	/*
11133 	 * Let the congestion control algorithm update congestion control
11134 	 * related information. This typically means increasing the
11135 	 * congestion window.
11136 	 */
11137 	if (tp->snd_wnd < ctf_outstanding(tp)) {
11138 		/* The peer collapsed the window */
11139 		rack_collapsed_window(rack, ctf_outstanding(tp), __LINE__);
11140 	} else if (rack->rc_has_collapsed)
11141 		rack_un_collapse_window(rack, __LINE__);
11142 	if ((rack->r_collapse_point_valid) &&
11143 	    (SEQ_GT(tp->snd_una, rack->r_ctl.high_collapse_point)))
11144 		rack->r_collapse_point_valid = 0;
11145 	/*
11146 	 * Pull snd_wl2 up to prevent seq wrap relative to th_ack.
11147 	 */
11148 	tp->snd_wl2 = th->th_ack;
11149 	tp->t_dupacks = 0;
11150 	m_freem(m);
11151 	/* ND6_HINT(tp);	 *//* Some progress has been made. */
11152 
11153 	/*
11154 	 * If all outstanding data are acked, stop retransmit timer,
11155 	 * otherwise restart timer using current (possibly backed-off)
11156 	 * value. If process is waiting for space, wakeup/selwakeup/signal.
11157 	 * If data are ready to send, let tcp_output decide between more
11158 	 * output or persist.
11159 	 */
11160 #ifdef TCPDEBUG
11161 	if (so->so_options & SO_DEBUG)
11162 		tcp_trace(TA_INPUT, ostate, tp,
11163 		    (void *)tcp_saveipgen,
11164 		    &tcp_savetcp, 0);
11165 #endif
11166 	if (under_pacing &&
11167 	    (rack->use_fixed_rate == 0) &&
11168 	    (rack->in_probe_rtt == 0) &&
11169 	    rack->rc_gp_dyn_mul &&
11170 	    rack->rc_always_pace) {
11171 		/* Check if we are dragging bottom */
11172 		rack_check_bottom_drag(tp, rack, so, acked);
11173 	}
11174 	if (tp->snd_una == tp->snd_max) {
11175 		tp->t_flags &= ~TF_PREVVALID;
11176 		rack->r_ctl.retran_during_recovery = 0;
11177 		rack->r_ctl.dsack_byte_cnt = 0;
11178 		rack->r_ctl.rc_went_idle_time = tcp_get_usecs(NULL);
11179 		if (rack->r_ctl.rc_went_idle_time == 0)
11180 			rack->r_ctl.rc_went_idle_time = 1;
11181 		rack_log_progress_event(rack, tp, 0, PROGRESS_CLEAR, __LINE__);
11182 		if (sbavail(&tptosocket(tp)->so_snd) == 0)
11183 			tp->t_acktime = 0;
11184 		rack_timer_cancel(tp, rack, rack->r_ctl.rc_rcvtime, __LINE__);
11185 	}
11186 	if (acked && rack->r_fast_output)
11187 		rack_gain_for_fastoutput(rack, tp, so, (uint32_t)acked);
11188 	if (sbavail(&so->so_snd)) {
11189 		rack->r_wanted_output = 1;
11190 	}
11191 	return (1);
11192 }
11193 
11194 /*
11195  * Return value of 1, the TCB is unlocked and most
11196  * likely gone, return value of 0, the TCP is still
11197  * locked.
11198  */
11199 static int
11200 rack_do_syn_sent(struct mbuf *m, struct tcphdr *th, struct socket *so,
11201     struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen,
11202     uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos)
11203 {
11204 	int32_t ret_val = 0;
11205 	int32_t todrop;
11206 	int32_t ourfinisacked = 0;
11207 	struct tcp_rack *rack;
11208 
11209 	INP_WLOCK_ASSERT(tptoinpcb(tp));
11210 
11211 	ctf_calc_rwin(so, tp);
11212 	/*
11213 	 * If the state is SYN_SENT: if seg contains an ACK, but not for our
11214 	 * SYN, drop the input. if seg contains a RST, then drop the
11215 	 * connection. if seg does not contain SYN, then drop it. Otherwise
11216 	 * this is an acceptable SYN segment initialize tp->rcv_nxt and
11217 	 * tp->irs if seg contains ack then advance tp->snd_una if seg
11218 	 * contains an ECE and ECN support is enabled, the stream is ECN
11219 	 * capable. if SYN has been acked change to ESTABLISHED else
11220 	 * SYN_RCVD state arrange for segment to be acked (eventually)
11221 	 * continue processing rest of data/controls.
11222 	 */
11223 	if ((thflags & TH_ACK) &&
11224 	    (SEQ_LEQ(th->th_ack, tp->iss) ||
11225 	    SEQ_GT(th->th_ack, tp->snd_max))) {
11226 		tcp_log_end_status(tp, TCP_EI_STATUS_RST_IN_FRONT);
11227 		ctf_do_dropwithreset(m, tp, th, BANDLIM_RST_OPENPORT, tlen);
11228 		return (1);
11229 	}
11230 	if ((thflags & (TH_ACK | TH_RST)) == (TH_ACK | TH_RST)) {
11231 		TCP_PROBE5(connect__refused, NULL, tp,
11232 		    mtod(m, const char *), tp, th);
11233 		tp = tcp_drop(tp, ECONNREFUSED);
11234 		ctf_do_drop(m, tp);
11235 		return (1);
11236 	}
11237 	if (thflags & TH_RST) {
11238 		ctf_do_drop(m, tp);
11239 		return (1);
11240 	}
11241 	if (!(thflags & TH_SYN)) {
11242 		ctf_do_drop(m, tp);
11243 		return (1);
11244 	}
11245 	tp->irs = th->th_seq;
11246 	tcp_rcvseqinit(tp);
11247 	rack = (struct tcp_rack *)tp->t_fb_ptr;
11248 	if (thflags & TH_ACK) {
11249 		int tfo_partial = 0;
11250 
11251 		KMOD_TCPSTAT_INC(tcps_connects);
11252 		soisconnected(so);
11253 #ifdef MAC
11254 		mac_socketpeer_set_from_mbuf(m, so);
11255 #endif
11256 		/* Do window scaling on this connection? */
11257 		if ((tp->t_flags & (TF_RCVD_SCALE | TF_REQ_SCALE)) ==
11258 		    (TF_RCVD_SCALE | TF_REQ_SCALE)) {
11259 			tp->rcv_scale = tp->request_r_scale;
11260 		}
11261 		tp->rcv_adv += min(tp->rcv_wnd,
11262 		    TCP_MAXWIN << tp->rcv_scale);
11263 		/*
11264 		 * If not all the data that was sent in the TFO SYN
11265 		 * has been acked, resend the remainder right away.
11266 		 */
11267 		if (IS_FASTOPEN(tp->t_flags) &&
11268 		    (tp->snd_una != tp->snd_max)) {
11269 			tp->snd_nxt = th->th_ack;
11270 			tfo_partial = 1;
11271 		}
11272 		/*
11273 		 * If there's data, delay ACK; if there's also a FIN ACKNOW
11274 		 * will be turned on later.
11275 		 */
11276 		if (DELAY_ACK(tp, tlen) && tlen != 0 && !tfo_partial) {
11277 			rack_timer_cancel(tp, rack,
11278 					  rack->r_ctl.rc_rcvtime, __LINE__);
11279 			tp->t_flags |= TF_DELACK;
11280 		} else {
11281 			rack->r_wanted_output = 1;
11282 			tp->t_flags |= TF_ACKNOW;
11283 			rack->rc_dack_toggle = 0;
11284 		}
11285 
11286 		tcp_ecn_input_syn_sent(tp, thflags, iptos);
11287 
11288 		if (SEQ_GT(th->th_ack, tp->snd_una)) {
11289 			/*
11290 			 * We advance snd_una for the
11291 			 * fast open case. If th_ack is
11292 			 * acknowledging data beyond
11293 			 * snd_una we can't just call
11294 			 * ack-processing since the
11295 			 * data stream in our send-map
11296 			 * will start at snd_una + 1 (one
11297 			 * beyond the SYN). If its just
11298 			 * equal we don't need to do that
11299 			 * and there is no send_map.
11300 			 */
11301 			tp->snd_una++;
11302 		}
11303 		/*
11304 		 * Received <SYN,ACK> in SYN_SENT[*] state. Transitions:
11305 		 * SYN_SENT  --> ESTABLISHED SYN_SENT* --> FIN_WAIT_1
11306 		 */
11307 		tp->t_starttime = ticks;
11308 		if (tp->t_flags & TF_NEEDFIN) {
11309 			tcp_state_change(tp, TCPS_FIN_WAIT_1);
11310 			tp->t_flags &= ~TF_NEEDFIN;
11311 			thflags &= ~TH_SYN;
11312 		} else {
11313 			tcp_state_change(tp, TCPS_ESTABLISHED);
11314 			TCP_PROBE5(connect__established, NULL, tp,
11315 			    mtod(m, const char *), tp, th);
11316 			rack_cc_conn_init(tp);
11317 		}
11318 	} else {
11319 		/*
11320 		 * Received initial SYN in SYN-SENT[*] state => simultaneous
11321 		 * open.  If segment contains CC option and there is a
11322 		 * cached CC, apply TAO test. If it succeeds, connection is *
11323 		 * half-synchronized. Otherwise, do 3-way handshake:
11324 		 * SYN-SENT -> SYN-RECEIVED SYN-SENT* -> SYN-RECEIVED* If
11325 		 * there was no CC option, clear cached CC value.
11326 		 */
11327 		tp->t_flags |= (TF_ACKNOW | TF_NEEDSYN | TF_SONOTCONN);
11328 		tcp_state_change(tp, TCPS_SYN_RECEIVED);
11329 	}
11330 	/*
11331 	 * Advance th->th_seq to correspond to first data byte. If data,
11332 	 * trim to stay within window, dropping FIN if necessary.
11333 	 */
11334 	th->th_seq++;
11335 	if (tlen > tp->rcv_wnd) {
11336 		todrop = tlen - tp->rcv_wnd;
11337 		m_adj(m, -todrop);
11338 		tlen = tp->rcv_wnd;
11339 		thflags &= ~TH_FIN;
11340 		KMOD_TCPSTAT_INC(tcps_rcvpackafterwin);
11341 		KMOD_TCPSTAT_ADD(tcps_rcvbyteafterwin, todrop);
11342 	}
11343 	tp->snd_wl1 = th->th_seq - 1;
11344 	tp->rcv_up = th->th_seq;
11345 	/*
11346 	 * Client side of transaction: already sent SYN and data. If the
11347 	 * remote host used T/TCP to validate the SYN, our data will be
11348 	 * ACK'd; if so, enter normal data segment processing in the middle
11349 	 * of step 5, ack processing. Otherwise, goto step 6.
11350 	 */
11351 	if (thflags & TH_ACK) {
11352 		/* For syn-sent we need to possibly update the rtt */
11353 		if ((to->to_flags & TOF_TS) != 0 && to->to_tsecr) {
11354 			uint32_t t, mcts;
11355 
11356 			mcts = tcp_ts_getticks();
11357 			t = (mcts - to->to_tsecr) * HPTS_USEC_IN_MSEC;
11358 			if (!tp->t_rttlow || tp->t_rttlow > t)
11359 				tp->t_rttlow = t;
11360 			rack_log_rtt_sample_calc(rack, t, (to->to_tsecr * 1000), (mcts * 1000), 4);
11361 			tcp_rack_xmit_timer(rack, t + 1, 1, t, 0, NULL, 2);
11362 			tcp_rack_xmit_timer_commit(rack, tp);
11363 		}
11364 		if (rack_process_ack(m, th, so, tp, to, tiwin, tlen, &ourfinisacked, thflags, &ret_val))
11365 			return (ret_val);
11366 		/* We may have changed to FIN_WAIT_1 above */
11367 		if (tp->t_state == TCPS_FIN_WAIT_1) {
11368 			/*
11369 			 * In FIN_WAIT_1 STATE in addition to the processing
11370 			 * for the ESTABLISHED state if our FIN is now
11371 			 * acknowledged then enter FIN_WAIT_2.
11372 			 */
11373 			if (ourfinisacked) {
11374 				/*
11375 				 * If we can't receive any more data, then
11376 				 * closing user can proceed. Starting the
11377 				 * timer is contrary to the specification,
11378 				 * but if we don't get a FIN we'll hang
11379 				 * forever.
11380 				 *
11381 				 * XXXjl: we should release the tp also, and
11382 				 * use a compressed state.
11383 				 */
11384 				if (so->so_rcv.sb_state & SBS_CANTRCVMORE) {
11385 					soisdisconnected(so);
11386 					tcp_timer_activate(tp, TT_2MSL,
11387 					    (tcp_fast_finwait2_recycle ?
11388 					    tcp_finwait2_timeout :
11389 					    TP_MAXIDLE(tp)));
11390 				}
11391 				tcp_state_change(tp, TCPS_FIN_WAIT_2);
11392 			}
11393 		}
11394 	}
11395 	return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
11396 	   tiwin, thflags, nxt_pkt));
11397 }
11398 
11399 /*
11400  * Return value of 1, the TCB is unlocked and most
11401  * likely gone, return value of 0, the TCP is still
11402  * locked.
11403  */
11404 static int
11405 rack_do_syn_recv(struct mbuf *m, struct tcphdr *th, struct socket *so,
11406     struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen,
11407     uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos)
11408 {
11409 	struct tcp_rack *rack;
11410 	int32_t ret_val = 0;
11411 	int32_t ourfinisacked = 0;
11412 
11413 	ctf_calc_rwin(so, tp);
11414 	if ((thflags & TH_ACK) &&
11415 	    (SEQ_LEQ(th->th_ack, tp->snd_una) ||
11416 	    SEQ_GT(th->th_ack, tp->snd_max))) {
11417 		tcp_log_end_status(tp, TCP_EI_STATUS_RST_IN_FRONT);
11418 		ctf_do_dropwithreset(m, tp, th, BANDLIM_RST_OPENPORT, tlen);
11419 		return (1);
11420 	}
11421 	rack = (struct tcp_rack *)tp->t_fb_ptr;
11422 	if (IS_FASTOPEN(tp->t_flags)) {
11423 		/*
11424 		 * When a TFO connection is in SYN_RECEIVED, the
11425 		 * only valid packets are the initial SYN, a
11426 		 * retransmit/copy of the initial SYN (possibly with
11427 		 * a subset of the original data), a valid ACK, a
11428 		 * FIN, or a RST.
11429 		 */
11430 		if ((thflags & (TH_SYN | TH_ACK)) == (TH_SYN | TH_ACK)) {
11431 			tcp_log_end_status(tp, TCP_EI_STATUS_RST_IN_FRONT);
11432 			ctf_do_dropwithreset(m, tp, th, BANDLIM_RST_OPENPORT, tlen);
11433 			return (1);
11434 		} else if (thflags & TH_SYN) {
11435 			/* non-initial SYN is ignored */
11436 			if ((rack->r_ctl.rc_hpts_flags & PACE_TMR_RXT) ||
11437 			    (rack->r_ctl.rc_hpts_flags & PACE_TMR_TLP) ||
11438 			    (rack->r_ctl.rc_hpts_flags & PACE_TMR_RACK)) {
11439 				ctf_do_drop(m, NULL);
11440 				return (0);
11441 			}
11442 		} else if (!(thflags & (TH_ACK | TH_FIN | TH_RST))) {
11443 			ctf_do_drop(m, NULL);
11444 			return (0);
11445 		}
11446 	}
11447 
11448 	if ((thflags & TH_RST) ||
11449 	    (tp->t_fin_is_rst && (thflags & TH_FIN)))
11450 		return (__ctf_process_rst(m, th, so, tp,
11451 					  &rack->r_ctl.challenge_ack_ts,
11452 					  &rack->r_ctl.challenge_ack_cnt));
11453 	/*
11454 	 * RFC 1323 PAWS: If we have a timestamp reply on this segment and
11455 	 * it's less than ts_recent, drop it.
11456 	 */
11457 	if ((to->to_flags & TOF_TS) != 0 && tp->ts_recent &&
11458 	    TSTMP_LT(to->to_tsval, tp->ts_recent)) {
11459 		if (ctf_ts_check(m, th, tp, tlen, thflags, &ret_val))
11460 			return (ret_val);
11461 	}
11462 	/*
11463 	 * In the SYN-RECEIVED state, validate that the packet belongs to
11464 	 * this connection before trimming the data to fit the receive
11465 	 * window.  Check the sequence number versus IRS since we know the
11466 	 * sequence numbers haven't wrapped.  This is a partial fix for the
11467 	 * "LAND" DoS attack.
11468 	 */
11469 	if (SEQ_LT(th->th_seq, tp->irs)) {
11470 		tcp_log_end_status(tp, TCP_EI_STATUS_RST_IN_FRONT);
11471 		ctf_do_dropwithreset(m, tp, th, BANDLIM_RST_OPENPORT, tlen);
11472 		return (1);
11473 	}
11474 	if (_ctf_drop_checks(to, m, th, tp, &tlen, &thflags, &drop_hdrlen, &ret_val,
11475 			      &rack->r_ctl.challenge_ack_ts,
11476 			      &rack->r_ctl.challenge_ack_cnt)) {
11477 		return (ret_val);
11478 	}
11479 	/*
11480 	 * If last ACK falls within this segment's sequence numbers, record
11481 	 * its timestamp. NOTE: 1) That the test incorporates suggestions
11482 	 * from the latest proposal of the tcplw@cray.com list (Braden
11483 	 * 1993/04/26). 2) That updating only on newer timestamps interferes
11484 	 * with our earlier PAWS tests, so this check should be solely
11485 	 * predicated on the sequence space of this segment. 3) That we
11486 	 * modify the segment boundary check to be Last.ACK.Sent <= SEG.SEQ
11487 	 * + SEG.Len  instead of RFC1323's Last.ACK.Sent < SEG.SEQ +
11488 	 * SEG.Len, This modified check allows us to overcome RFC1323's
11489 	 * limitations as described in Stevens TCP/IP Illustrated Vol. 2
11490 	 * p.869. In such cases, we can still calculate the RTT correctly
11491 	 * when RCV.NXT == Last.ACK.Sent.
11492 	 */
11493 	if ((to->to_flags & TOF_TS) != 0 &&
11494 	    SEQ_LEQ(th->th_seq, tp->last_ack_sent) &&
11495 	    SEQ_LEQ(tp->last_ack_sent, th->th_seq + tlen +
11496 	    ((thflags & (TH_SYN | TH_FIN)) != 0))) {
11497 		tp->ts_recent_age = tcp_ts_getticks();
11498 		tp->ts_recent = to->to_tsval;
11499 	}
11500 	tp->snd_wnd = tiwin;
11501 	rack_validate_fo_sendwin_up(tp, rack);
11502 	/*
11503 	 * If the ACK bit is off:  if in SYN-RECEIVED state or SENDSYN flag
11504 	 * is on (half-synchronized state), then queue data for later
11505 	 * processing; else drop segment and return.
11506 	 */
11507 	if ((thflags & TH_ACK) == 0) {
11508 		if (IS_FASTOPEN(tp->t_flags)) {
11509 			rack_cc_conn_init(tp);
11510 		}
11511 		return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
11512 		    tiwin, thflags, nxt_pkt));
11513 	}
11514 	KMOD_TCPSTAT_INC(tcps_connects);
11515 	if (tp->t_flags & TF_SONOTCONN) {
11516 		tp->t_flags &= ~TF_SONOTCONN;
11517 		soisconnected(so);
11518 	}
11519 	/* Do window scaling? */
11520 	if ((tp->t_flags & (TF_RCVD_SCALE | TF_REQ_SCALE)) ==
11521 	    (TF_RCVD_SCALE | TF_REQ_SCALE)) {
11522 		tp->rcv_scale = tp->request_r_scale;
11523 	}
11524 	/*
11525 	 * Make transitions: SYN-RECEIVED  -> ESTABLISHED SYN-RECEIVED* ->
11526 	 * FIN-WAIT-1
11527 	 */
11528 	tp->t_starttime = ticks;
11529 	if (IS_FASTOPEN(tp->t_flags) && tp->t_tfo_pending) {
11530 		tcp_fastopen_decrement_counter(tp->t_tfo_pending);
11531 		tp->t_tfo_pending = NULL;
11532 	}
11533 	if (tp->t_flags & TF_NEEDFIN) {
11534 		tcp_state_change(tp, TCPS_FIN_WAIT_1);
11535 		tp->t_flags &= ~TF_NEEDFIN;
11536 	} else {
11537 		tcp_state_change(tp, TCPS_ESTABLISHED);
11538 		TCP_PROBE5(accept__established, NULL, tp,
11539 		    mtod(m, const char *), tp, th);
11540 		/*
11541 		 * TFO connections call cc_conn_init() during SYN
11542 		 * processing.  Calling it again here for such connections
11543 		 * is not harmless as it would undo the snd_cwnd reduction
11544 		 * that occurs when a TFO SYN|ACK is retransmitted.
11545 		 */
11546 		if (!IS_FASTOPEN(tp->t_flags))
11547 			rack_cc_conn_init(tp);
11548 	}
11549 	/*
11550 	 * Account for the ACK of our SYN prior to
11551 	 * regular ACK processing below, except for
11552 	 * simultaneous SYN, which is handled later.
11553 	 */
11554 	if (SEQ_GT(th->th_ack, tp->snd_una) && !(tp->t_flags & TF_NEEDSYN))
11555 		tp->snd_una++;
11556 	/*
11557 	 * If segment contains data or ACK, will call tcp_reass() later; if
11558 	 * not, do so now to pass queued data to user.
11559 	 */
11560 	if (tlen == 0 && (thflags & TH_FIN) == 0) {
11561 		(void) tcp_reass(tp, (struct tcphdr *)0, NULL, 0,
11562 		    (struct mbuf *)0);
11563 		if (tp->t_flags & TF_WAKESOR) {
11564 			tp->t_flags &= ~TF_WAKESOR;
11565 			/* NB: sorwakeup_locked() does an implicit unlock. */
11566 			sorwakeup_locked(so);
11567 		}
11568 	}
11569 	tp->snd_wl1 = th->th_seq - 1;
11570 	/* For syn-recv we need to possibly update the rtt */
11571 	if ((to->to_flags & TOF_TS) != 0 && to->to_tsecr) {
11572 		uint32_t t, mcts;
11573 
11574 		mcts = tcp_ts_getticks();
11575 		t = (mcts - to->to_tsecr) * HPTS_USEC_IN_MSEC;
11576 		if (!tp->t_rttlow || tp->t_rttlow > t)
11577 			tp->t_rttlow = t;
11578 		rack_log_rtt_sample_calc(rack, t, (to->to_tsecr * 1000), (mcts * 1000), 5);
11579 		tcp_rack_xmit_timer(rack, t + 1, 1, t, 0, NULL, 2);
11580 		tcp_rack_xmit_timer_commit(rack, tp);
11581 	}
11582 	if (rack_process_ack(m, th, so, tp, to, tiwin, tlen, &ourfinisacked, thflags, &ret_val)) {
11583 		return (ret_val);
11584 	}
11585 	if (tp->t_state == TCPS_FIN_WAIT_1) {
11586 		/* We could have went to FIN_WAIT_1 (or EST) above */
11587 		/*
11588 		 * In FIN_WAIT_1 STATE in addition to the processing for the
11589 		 * ESTABLISHED state if our FIN is now acknowledged then
11590 		 * enter FIN_WAIT_2.
11591 		 */
11592 		if (ourfinisacked) {
11593 			/*
11594 			 * If we can't receive any more data, then closing
11595 			 * user can proceed. Starting the timer is contrary
11596 			 * to the specification, but if we don't get a FIN
11597 			 * we'll hang forever.
11598 			 *
11599 			 * XXXjl: we should release the tp also, and use a
11600 			 * compressed state.
11601 			 */
11602 			if (so->so_rcv.sb_state & SBS_CANTRCVMORE) {
11603 				soisdisconnected(so);
11604 				tcp_timer_activate(tp, TT_2MSL,
11605 				    (tcp_fast_finwait2_recycle ?
11606 				    tcp_finwait2_timeout :
11607 				    TP_MAXIDLE(tp)));
11608 			}
11609 			tcp_state_change(tp, TCPS_FIN_WAIT_2);
11610 		}
11611 	}
11612 	return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
11613 	    tiwin, thflags, nxt_pkt));
11614 }
11615 
11616 /*
11617  * Return value of 1, the TCB is unlocked and most
11618  * likely gone, return value of 0, the TCP is still
11619  * locked.
11620  */
11621 static int
11622 rack_do_established(struct mbuf *m, struct tcphdr *th, struct socket *so,
11623     struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen,
11624     uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos)
11625 {
11626 	int32_t ret_val = 0;
11627 	struct tcp_rack *rack;
11628 
11629 	/*
11630 	 * Header prediction: check for the two common cases of a
11631 	 * uni-directional data xfer.  If the packet has no control flags,
11632 	 * is in-sequence, the window didn't change and we're not
11633 	 * retransmitting, it's a candidate.  If the length is zero and the
11634 	 * ack moved forward, we're the sender side of the xfer.  Just free
11635 	 * the data acked & wake any higher level process that was blocked
11636 	 * waiting for space.  If the length is non-zero and the ack didn't
11637 	 * move, we're the receiver side.  If we're getting packets in-order
11638 	 * (the reassembly queue is empty), add the data toc The socket
11639 	 * buffer and note that we need a delayed ack. Make sure that the
11640 	 * hidden state-flags are also off. Since we check for
11641 	 * TCPS_ESTABLISHED first, it can only be TH_NEEDSYN.
11642 	 */
11643 	rack = (struct tcp_rack *)tp->t_fb_ptr;
11644 	if (__predict_true(((to->to_flags & TOF_SACK) == 0)) &&
11645 	    __predict_true((thflags & (TH_SYN | TH_FIN | TH_RST | TH_ACK)) == TH_ACK) &&
11646 	    __predict_true(SEGQ_EMPTY(tp)) &&
11647 	    __predict_true(th->th_seq == tp->rcv_nxt)) {
11648 		if (tlen == 0) {
11649 			if (rack_fastack(m, th, so, tp, to, drop_hdrlen, tlen,
11650 			    tiwin, nxt_pkt, rack->r_ctl.rc_rcvtime)) {
11651 				return (0);
11652 			}
11653 		} else {
11654 			if (rack_do_fastnewdata(m, th, so, tp, to, drop_hdrlen, tlen,
11655 			    tiwin, nxt_pkt, iptos)) {
11656 				return (0);
11657 			}
11658 		}
11659 	}
11660 	ctf_calc_rwin(so, tp);
11661 
11662 	if ((thflags & TH_RST) ||
11663 	    (tp->t_fin_is_rst && (thflags & TH_FIN)))
11664 		return (__ctf_process_rst(m, th, so, tp,
11665 					  &rack->r_ctl.challenge_ack_ts,
11666 					  &rack->r_ctl.challenge_ack_cnt));
11667 
11668 	/*
11669 	 * RFC5961 Section 4.2 Send challenge ACK for any SYN in
11670 	 * synchronized state.
11671 	 */
11672 	if (thflags & TH_SYN) {
11673 		ctf_challenge_ack(m, th, tp, iptos, &ret_val);
11674 		return (ret_val);
11675 	}
11676 	/*
11677 	 * RFC 1323 PAWS: If we have a timestamp reply on this segment and
11678 	 * it's less than ts_recent, drop it.
11679 	 */
11680 	if ((to->to_flags & TOF_TS) != 0 && tp->ts_recent &&
11681 	    TSTMP_LT(to->to_tsval, tp->ts_recent)) {
11682 		if (ctf_ts_check(m, th, tp, tlen, thflags, &ret_val))
11683 			return (ret_val);
11684 	}
11685 	if (_ctf_drop_checks(to, m, th, tp, &tlen, &thflags, &drop_hdrlen, &ret_val,
11686 			      &rack->r_ctl.challenge_ack_ts,
11687 			      &rack->r_ctl.challenge_ack_cnt)) {
11688 		return (ret_val);
11689 	}
11690 	/*
11691 	 * If last ACK falls within this segment's sequence numbers, record
11692 	 * its timestamp. NOTE: 1) That the test incorporates suggestions
11693 	 * from the latest proposal of the tcplw@cray.com list (Braden
11694 	 * 1993/04/26). 2) That updating only on newer timestamps interferes
11695 	 * with our earlier PAWS tests, so this check should be solely
11696 	 * predicated on the sequence space of this segment. 3) That we
11697 	 * modify the segment boundary check to be Last.ACK.Sent <= SEG.SEQ
11698 	 * + SEG.Len  instead of RFC1323's Last.ACK.Sent < SEG.SEQ +
11699 	 * SEG.Len, This modified check allows us to overcome RFC1323's
11700 	 * limitations as described in Stevens TCP/IP Illustrated Vol. 2
11701 	 * p.869. In such cases, we can still calculate the RTT correctly
11702 	 * when RCV.NXT == Last.ACK.Sent.
11703 	 */
11704 	if ((to->to_flags & TOF_TS) != 0 &&
11705 	    SEQ_LEQ(th->th_seq, tp->last_ack_sent) &&
11706 	    SEQ_LEQ(tp->last_ack_sent, th->th_seq + tlen +
11707 	    ((thflags & (TH_SYN | TH_FIN)) != 0))) {
11708 		tp->ts_recent_age = tcp_ts_getticks();
11709 		tp->ts_recent = to->to_tsval;
11710 	}
11711 	/*
11712 	 * If the ACK bit is off:  if in SYN-RECEIVED state or SENDSYN flag
11713 	 * is on (half-synchronized state), then queue data for later
11714 	 * processing; else drop segment and return.
11715 	 */
11716 	if ((thflags & TH_ACK) == 0) {
11717 		if (tp->t_flags & TF_NEEDSYN) {
11718 			return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
11719 			    tiwin, thflags, nxt_pkt));
11720 
11721 		} else if (tp->t_flags & TF_ACKNOW) {
11722 			ctf_do_dropafterack(m, tp, th, thflags, tlen, &ret_val);
11723 			((struct tcp_rack *)tp->t_fb_ptr)->r_wanted_output = 1;
11724 			return (ret_val);
11725 		} else {
11726 			ctf_do_drop(m, NULL);
11727 			return (0);
11728 		}
11729 	}
11730 	/*
11731 	 * Ack processing.
11732 	 */
11733 	if (rack_process_ack(m, th, so, tp, to, tiwin, tlen, NULL, thflags, &ret_val)) {
11734 		return (ret_val);
11735 	}
11736 	if (sbavail(&so->so_snd)) {
11737 		if (ctf_progress_timeout_check(tp, true)) {
11738 			rack_log_progress_event(rack, tp, tick, PROGRESS_DROP, __LINE__);
11739 			ctf_do_dropwithreset_conn(m, tp, th, BANDLIM_RST_OPENPORT, tlen);
11740 			return (1);
11741 		}
11742 	}
11743 	/* State changes only happen in rack_process_data() */
11744 	return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
11745 	    tiwin, thflags, nxt_pkt));
11746 }
11747 
11748 /*
11749  * Return value of 1, the TCB is unlocked and most
11750  * likely gone, return value of 0, the TCP is still
11751  * locked.
11752  */
11753 static int
11754 rack_do_close_wait(struct mbuf *m, struct tcphdr *th, struct socket *so,
11755     struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen,
11756     uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos)
11757 {
11758 	int32_t ret_val = 0;
11759 	struct tcp_rack *rack;
11760 
11761 	rack = (struct tcp_rack *)tp->t_fb_ptr;
11762 	ctf_calc_rwin(so, tp);
11763 	if ((thflags & TH_RST) ||
11764 	    (tp->t_fin_is_rst && (thflags & TH_FIN)))
11765 		return (__ctf_process_rst(m, th, so, tp,
11766 					  &rack->r_ctl.challenge_ack_ts,
11767 					  &rack->r_ctl.challenge_ack_cnt));
11768 	/*
11769 	 * RFC5961 Section 4.2 Send challenge ACK for any SYN in
11770 	 * synchronized state.
11771 	 */
11772 	if (thflags & TH_SYN) {
11773 		ctf_challenge_ack(m, th, tp, iptos, &ret_val);
11774 		return (ret_val);
11775 	}
11776 	/*
11777 	 * RFC 1323 PAWS: If we have a timestamp reply on this segment and
11778 	 * it's less than ts_recent, drop it.
11779 	 */
11780 	if ((to->to_flags & TOF_TS) != 0 && tp->ts_recent &&
11781 	    TSTMP_LT(to->to_tsval, tp->ts_recent)) {
11782 		if (ctf_ts_check(m, th, tp, tlen, thflags, &ret_val))
11783 			return (ret_val);
11784 	}
11785 	if (_ctf_drop_checks(to, m, th, tp, &tlen, &thflags, &drop_hdrlen, &ret_val,
11786 			      &rack->r_ctl.challenge_ack_ts,
11787 			      &rack->r_ctl.challenge_ack_cnt)) {
11788 		return (ret_val);
11789 	}
11790 	/*
11791 	 * If last ACK falls within this segment's sequence numbers, record
11792 	 * its timestamp. NOTE: 1) That the test incorporates suggestions
11793 	 * from the latest proposal of the tcplw@cray.com list (Braden
11794 	 * 1993/04/26). 2) That updating only on newer timestamps interferes
11795 	 * with our earlier PAWS tests, so this check should be solely
11796 	 * predicated on the sequence space of this segment. 3) That we
11797 	 * modify the segment boundary check to be Last.ACK.Sent <= SEG.SEQ
11798 	 * + SEG.Len  instead of RFC1323's Last.ACK.Sent < SEG.SEQ +
11799 	 * SEG.Len, This modified check allows us to overcome RFC1323's
11800 	 * limitations as described in Stevens TCP/IP Illustrated Vol. 2
11801 	 * p.869. In such cases, we can still calculate the RTT correctly
11802 	 * when RCV.NXT == Last.ACK.Sent.
11803 	 */
11804 	if ((to->to_flags & TOF_TS) != 0 &&
11805 	    SEQ_LEQ(th->th_seq, tp->last_ack_sent) &&
11806 	    SEQ_LEQ(tp->last_ack_sent, th->th_seq + tlen +
11807 	    ((thflags & (TH_SYN | TH_FIN)) != 0))) {
11808 		tp->ts_recent_age = tcp_ts_getticks();
11809 		tp->ts_recent = to->to_tsval;
11810 	}
11811 	/*
11812 	 * If the ACK bit is off:  if in SYN-RECEIVED state or SENDSYN flag
11813 	 * is on (half-synchronized state), then queue data for later
11814 	 * processing; else drop segment and return.
11815 	 */
11816 	if ((thflags & TH_ACK) == 0) {
11817 		if (tp->t_flags & TF_NEEDSYN) {
11818 			return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
11819 			    tiwin, thflags, nxt_pkt));
11820 
11821 		} else if (tp->t_flags & TF_ACKNOW) {
11822 			ctf_do_dropafterack(m, tp, th, thflags, tlen, &ret_val);
11823 			((struct tcp_rack *)tp->t_fb_ptr)->r_wanted_output = 1;
11824 			return (ret_val);
11825 		} else {
11826 			ctf_do_drop(m, NULL);
11827 			return (0);
11828 		}
11829 	}
11830 	/*
11831 	 * Ack processing.
11832 	 */
11833 	if (rack_process_ack(m, th, so, tp, to, tiwin, tlen, NULL, thflags, &ret_val)) {
11834 		return (ret_val);
11835 	}
11836 	if (sbavail(&so->so_snd)) {
11837 		if (ctf_progress_timeout_check(tp, true)) {
11838 			rack_log_progress_event((struct tcp_rack *)tp->t_fb_ptr,
11839 						tp, tick, PROGRESS_DROP, __LINE__);
11840 			ctf_do_dropwithreset_conn(m, tp, th, BANDLIM_RST_OPENPORT, tlen);
11841 			return (1);
11842 		}
11843 	}
11844 	return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
11845 	    tiwin, thflags, nxt_pkt));
11846 }
11847 
11848 static int
11849 rack_check_data_after_close(struct mbuf *m,
11850     struct tcpcb *tp, int32_t *tlen, struct tcphdr *th, struct socket *so)
11851 {
11852 	struct tcp_rack *rack;
11853 
11854 	rack = (struct tcp_rack *)tp->t_fb_ptr;
11855 	if (rack->rc_allow_data_af_clo == 0) {
11856 	close_now:
11857 		tcp_log_end_status(tp, TCP_EI_STATUS_DATA_A_CLOSE);
11858 		/* tcp_close will kill the inp pre-log the Reset */
11859 		tcp_log_end_status(tp, TCP_EI_STATUS_SERVER_RST);
11860 		tp = tcp_close(tp);
11861 		KMOD_TCPSTAT_INC(tcps_rcvafterclose);
11862 		ctf_do_dropwithreset(m, tp, th, BANDLIM_UNLIMITED, (*tlen));
11863 		return (1);
11864 	}
11865 	if (sbavail(&so->so_snd) == 0)
11866 		goto close_now;
11867 	/* Ok we allow data that is ignored and a followup reset */
11868 	tcp_log_end_status(tp, TCP_EI_STATUS_DATA_A_CLOSE);
11869 	tp->rcv_nxt = th->th_seq + *tlen;
11870 	tp->t_flags2 |= TF2_DROP_AF_DATA;
11871 	rack->r_wanted_output = 1;
11872 	*tlen = 0;
11873 	return (0);
11874 }
11875 
11876 /*
11877  * Return value of 1, the TCB is unlocked and most
11878  * likely gone, return value of 0, the TCP is still
11879  * locked.
11880  */
11881 static int
11882 rack_do_fin_wait_1(struct mbuf *m, struct tcphdr *th, struct socket *so,
11883     struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen,
11884     uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos)
11885 {
11886 	int32_t ret_val = 0;
11887 	int32_t ourfinisacked = 0;
11888 	struct tcp_rack *rack;
11889 
11890 	rack = (struct tcp_rack *)tp->t_fb_ptr;
11891 	ctf_calc_rwin(so, tp);
11892 
11893 	if ((thflags & TH_RST) ||
11894 	    (tp->t_fin_is_rst && (thflags & TH_FIN)))
11895 		return (__ctf_process_rst(m, th, so, tp,
11896 					  &rack->r_ctl.challenge_ack_ts,
11897 					  &rack->r_ctl.challenge_ack_cnt));
11898 	/*
11899 	 * RFC5961 Section 4.2 Send challenge ACK for any SYN in
11900 	 * synchronized state.
11901 	 */
11902 	if (thflags & TH_SYN) {
11903 		ctf_challenge_ack(m, th, tp, iptos, &ret_val);
11904 		return (ret_val);
11905 	}
11906 	/*
11907 	 * RFC 1323 PAWS: If we have a timestamp reply on this segment and
11908 	 * it's less than ts_recent, drop it.
11909 	 */
11910 	if ((to->to_flags & TOF_TS) != 0 && tp->ts_recent &&
11911 	    TSTMP_LT(to->to_tsval, tp->ts_recent)) {
11912 		if (ctf_ts_check(m, th, tp, tlen, thflags, &ret_val))
11913 			return (ret_val);
11914 	}
11915 	if (_ctf_drop_checks(to, m, th, tp, &tlen, &thflags, &drop_hdrlen, &ret_val,
11916 			      &rack->r_ctl.challenge_ack_ts,
11917 			      &rack->r_ctl.challenge_ack_cnt)) {
11918 		return (ret_val);
11919 	}
11920 	/*
11921 	 * If new data are received on a connection after the user processes
11922 	 * are gone, then RST the other end.
11923 	 */
11924 	if ((tp->t_flags & TF_CLOSED) && tlen &&
11925 	    rack_check_data_after_close(m, tp, &tlen, th, so))
11926 		return (1);
11927 	/*
11928 	 * If last ACK falls within this segment's sequence numbers, record
11929 	 * its timestamp. NOTE: 1) That the test incorporates suggestions
11930 	 * from the latest proposal of the tcplw@cray.com list (Braden
11931 	 * 1993/04/26). 2) That updating only on newer timestamps interferes
11932 	 * with our earlier PAWS tests, so this check should be solely
11933 	 * predicated on the sequence space of this segment. 3) That we
11934 	 * modify the segment boundary check to be Last.ACK.Sent <= SEG.SEQ
11935 	 * + SEG.Len  instead of RFC1323's Last.ACK.Sent < SEG.SEQ +
11936 	 * SEG.Len, This modified check allows us to overcome RFC1323's
11937 	 * limitations as described in Stevens TCP/IP Illustrated Vol. 2
11938 	 * p.869. In such cases, we can still calculate the RTT correctly
11939 	 * when RCV.NXT == Last.ACK.Sent.
11940 	 */
11941 	if ((to->to_flags & TOF_TS) != 0 &&
11942 	    SEQ_LEQ(th->th_seq, tp->last_ack_sent) &&
11943 	    SEQ_LEQ(tp->last_ack_sent, th->th_seq + tlen +
11944 	    ((thflags & (TH_SYN | TH_FIN)) != 0))) {
11945 		tp->ts_recent_age = tcp_ts_getticks();
11946 		tp->ts_recent = to->to_tsval;
11947 	}
11948 	/*
11949 	 * If the ACK bit is off:  if in SYN-RECEIVED state or SENDSYN flag
11950 	 * is on (half-synchronized state), then queue data for later
11951 	 * processing; else drop segment and return.
11952 	 */
11953 	if ((thflags & TH_ACK) == 0) {
11954 		if (tp->t_flags & TF_NEEDSYN) {
11955 			return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
11956 			    tiwin, thflags, nxt_pkt));
11957 		} else if (tp->t_flags & TF_ACKNOW) {
11958 			ctf_do_dropafterack(m, tp, th, thflags, tlen, &ret_val);
11959 			((struct tcp_rack *)tp->t_fb_ptr)->r_wanted_output = 1;
11960 			return (ret_val);
11961 		} else {
11962 			ctf_do_drop(m, NULL);
11963 			return (0);
11964 		}
11965 	}
11966 	/*
11967 	 * Ack processing.
11968 	 */
11969 	if (rack_process_ack(m, th, so, tp, to, tiwin, tlen, &ourfinisacked, thflags, &ret_val)) {
11970 		return (ret_val);
11971 	}
11972 	if (ourfinisacked) {
11973 		/*
11974 		 * If we can't receive any more data, then closing user can
11975 		 * proceed. Starting the timer is contrary to the
11976 		 * specification, but if we don't get a FIN we'll hang
11977 		 * forever.
11978 		 *
11979 		 * XXXjl: we should release the tp also, and use a
11980 		 * compressed state.
11981 		 */
11982 		if (so->so_rcv.sb_state & SBS_CANTRCVMORE) {
11983 			soisdisconnected(so);
11984 			tcp_timer_activate(tp, TT_2MSL,
11985 			    (tcp_fast_finwait2_recycle ?
11986 			    tcp_finwait2_timeout :
11987 			    TP_MAXIDLE(tp)));
11988 		}
11989 		tcp_state_change(tp, TCPS_FIN_WAIT_2);
11990 	}
11991 	if (sbavail(&so->so_snd)) {
11992 		if (ctf_progress_timeout_check(tp, true)) {
11993 			rack_log_progress_event((struct tcp_rack *)tp->t_fb_ptr,
11994 						tp, tick, PROGRESS_DROP, __LINE__);
11995 			ctf_do_dropwithreset_conn(m, tp, th, BANDLIM_RST_OPENPORT, tlen);
11996 			return (1);
11997 		}
11998 	}
11999 	return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
12000 	    tiwin, thflags, nxt_pkt));
12001 }
12002 
12003 /*
12004  * Return value of 1, the TCB is unlocked and most
12005  * likely gone, return value of 0, the TCP is still
12006  * locked.
12007  */
12008 static int
12009 rack_do_closing(struct mbuf *m, struct tcphdr *th, struct socket *so,
12010     struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen,
12011     uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos)
12012 {
12013 	int32_t ret_val = 0;
12014 	int32_t ourfinisacked = 0;
12015 	struct tcp_rack *rack;
12016 
12017 	rack = (struct tcp_rack *)tp->t_fb_ptr;
12018 	ctf_calc_rwin(so, tp);
12019 
12020 	if ((thflags & TH_RST) ||
12021 	    (tp->t_fin_is_rst && (thflags & TH_FIN)))
12022 		return (__ctf_process_rst(m, th, so, tp,
12023 					  &rack->r_ctl.challenge_ack_ts,
12024 					  &rack->r_ctl.challenge_ack_cnt));
12025 	/*
12026 	 * RFC5961 Section 4.2 Send challenge ACK for any SYN in
12027 	 * synchronized state.
12028 	 */
12029 	if (thflags & TH_SYN) {
12030 		ctf_challenge_ack(m, th, tp, iptos, &ret_val);
12031 		return (ret_val);
12032 	}
12033 	/*
12034 	 * RFC 1323 PAWS: If we have a timestamp reply on this segment and
12035 	 * it's less than ts_recent, drop it.
12036 	 */
12037 	if ((to->to_flags & TOF_TS) != 0 && tp->ts_recent &&
12038 	    TSTMP_LT(to->to_tsval, tp->ts_recent)) {
12039 		if (ctf_ts_check(m, th, tp, tlen, thflags, &ret_val))
12040 			return (ret_val);
12041 	}
12042 	if (_ctf_drop_checks(to, m, th, tp, &tlen, &thflags, &drop_hdrlen, &ret_val,
12043 			      &rack->r_ctl.challenge_ack_ts,
12044 			      &rack->r_ctl.challenge_ack_cnt)) {
12045 		return (ret_val);
12046 	}
12047 	/*
12048 	 * If new data are received on a connection after the user processes
12049 	 * are gone, then RST the other end.
12050 	 */
12051 	if ((tp->t_flags & TF_CLOSED) && tlen &&
12052 	    rack_check_data_after_close(m, tp, &tlen, th, so))
12053 		return (1);
12054 	/*
12055 	 * If last ACK falls within this segment's sequence numbers, record
12056 	 * its timestamp. NOTE: 1) That the test incorporates suggestions
12057 	 * from the latest proposal of the tcplw@cray.com list (Braden
12058 	 * 1993/04/26). 2) That updating only on newer timestamps interferes
12059 	 * with our earlier PAWS tests, so this check should be solely
12060 	 * predicated on the sequence space of this segment. 3) That we
12061 	 * modify the segment boundary check to be Last.ACK.Sent <= SEG.SEQ
12062 	 * + SEG.Len  instead of RFC1323's Last.ACK.Sent < SEG.SEQ +
12063 	 * SEG.Len, This modified check allows us to overcome RFC1323's
12064 	 * limitations as described in Stevens TCP/IP Illustrated Vol. 2
12065 	 * p.869. In such cases, we can still calculate the RTT correctly
12066 	 * when RCV.NXT == Last.ACK.Sent.
12067 	 */
12068 	if ((to->to_flags & TOF_TS) != 0 &&
12069 	    SEQ_LEQ(th->th_seq, tp->last_ack_sent) &&
12070 	    SEQ_LEQ(tp->last_ack_sent, th->th_seq + tlen +
12071 	    ((thflags & (TH_SYN | TH_FIN)) != 0))) {
12072 		tp->ts_recent_age = tcp_ts_getticks();
12073 		tp->ts_recent = to->to_tsval;
12074 	}
12075 	/*
12076 	 * If the ACK bit is off:  if in SYN-RECEIVED state or SENDSYN flag
12077 	 * is on (half-synchronized state), then queue data for later
12078 	 * processing; else drop segment and return.
12079 	 */
12080 	if ((thflags & TH_ACK) == 0) {
12081 		if (tp->t_flags & TF_NEEDSYN) {
12082 			return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
12083 			    tiwin, thflags, nxt_pkt));
12084 		} else if (tp->t_flags & TF_ACKNOW) {
12085 			ctf_do_dropafterack(m, tp, th, thflags, tlen, &ret_val);
12086 			((struct tcp_rack *)tp->t_fb_ptr)->r_wanted_output = 1;
12087 			return (ret_val);
12088 		} else {
12089 			ctf_do_drop(m, NULL);
12090 			return (0);
12091 		}
12092 	}
12093 	/*
12094 	 * Ack processing.
12095 	 */
12096 	if (rack_process_ack(m, th, so, tp, to, tiwin, tlen, &ourfinisacked, thflags, &ret_val)) {
12097 		return (ret_val);
12098 	}
12099 	if (ourfinisacked) {
12100 		tcp_twstart(tp);
12101 		m_freem(m);
12102 		return (1);
12103 	}
12104 	if (sbavail(&so->so_snd)) {
12105 		if (ctf_progress_timeout_check(tp, true)) {
12106 			rack_log_progress_event((struct tcp_rack *)tp->t_fb_ptr,
12107 						tp, tick, PROGRESS_DROP, __LINE__);
12108 			ctf_do_dropwithreset_conn(m, tp, th, BANDLIM_RST_OPENPORT, tlen);
12109 			return (1);
12110 		}
12111 	}
12112 	return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
12113 	    tiwin, thflags, nxt_pkt));
12114 }
12115 
12116 /*
12117  * Return value of 1, the TCB is unlocked and most
12118  * likely gone, return value of 0, the TCP is still
12119  * locked.
12120  */
12121 static int
12122 rack_do_lastack(struct mbuf *m, struct tcphdr *th, struct socket *so,
12123     struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen,
12124     uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos)
12125 {
12126 	int32_t ret_val = 0;
12127 	int32_t ourfinisacked = 0;
12128 	struct tcp_rack *rack;
12129 
12130 	rack = (struct tcp_rack *)tp->t_fb_ptr;
12131 	ctf_calc_rwin(so, tp);
12132 
12133 	if ((thflags & TH_RST) ||
12134 	    (tp->t_fin_is_rst && (thflags & TH_FIN)))
12135 		return (__ctf_process_rst(m, th, so, tp,
12136 					  &rack->r_ctl.challenge_ack_ts,
12137 					  &rack->r_ctl.challenge_ack_cnt));
12138 	/*
12139 	 * RFC5961 Section 4.2 Send challenge ACK for any SYN in
12140 	 * synchronized state.
12141 	 */
12142 	if (thflags & TH_SYN) {
12143 		ctf_challenge_ack(m, th, tp, iptos, &ret_val);
12144 		return (ret_val);
12145 	}
12146 	/*
12147 	 * RFC 1323 PAWS: If we have a timestamp reply on this segment and
12148 	 * it's less than ts_recent, drop it.
12149 	 */
12150 	if ((to->to_flags & TOF_TS) != 0 && tp->ts_recent &&
12151 	    TSTMP_LT(to->to_tsval, tp->ts_recent)) {
12152 		if (ctf_ts_check(m, th, tp, tlen, thflags, &ret_val))
12153 			return (ret_val);
12154 	}
12155 	if (_ctf_drop_checks(to, m, th, tp, &tlen, &thflags, &drop_hdrlen, &ret_val,
12156 			      &rack->r_ctl.challenge_ack_ts,
12157 			      &rack->r_ctl.challenge_ack_cnt)) {
12158 		return (ret_val);
12159 	}
12160 	/*
12161 	 * If new data are received on a connection after the user processes
12162 	 * are gone, then RST the other end.
12163 	 */
12164 	if ((tp->t_flags & TF_CLOSED) && tlen &&
12165 	    rack_check_data_after_close(m, tp, &tlen, th, so))
12166 		return (1);
12167 	/*
12168 	 * If last ACK falls within this segment's sequence numbers, record
12169 	 * its timestamp. NOTE: 1) That the test incorporates suggestions
12170 	 * from the latest proposal of the tcplw@cray.com list (Braden
12171 	 * 1993/04/26). 2) That updating only on newer timestamps interferes
12172 	 * with our earlier PAWS tests, so this check should be solely
12173 	 * predicated on the sequence space of this segment. 3) That we
12174 	 * modify the segment boundary check to be Last.ACK.Sent <= SEG.SEQ
12175 	 * + SEG.Len  instead of RFC1323's Last.ACK.Sent < SEG.SEQ +
12176 	 * SEG.Len, This modified check allows us to overcome RFC1323's
12177 	 * limitations as described in Stevens TCP/IP Illustrated Vol. 2
12178 	 * p.869. In such cases, we can still calculate the RTT correctly
12179 	 * when RCV.NXT == Last.ACK.Sent.
12180 	 */
12181 	if ((to->to_flags & TOF_TS) != 0 &&
12182 	    SEQ_LEQ(th->th_seq, tp->last_ack_sent) &&
12183 	    SEQ_LEQ(tp->last_ack_sent, th->th_seq + tlen +
12184 	    ((thflags & (TH_SYN | TH_FIN)) != 0))) {
12185 		tp->ts_recent_age = tcp_ts_getticks();
12186 		tp->ts_recent = to->to_tsval;
12187 	}
12188 	/*
12189 	 * If the ACK bit is off:  if in SYN-RECEIVED state or SENDSYN flag
12190 	 * is on (half-synchronized state), then queue data for later
12191 	 * processing; else drop segment and return.
12192 	 */
12193 	if ((thflags & TH_ACK) == 0) {
12194 		if (tp->t_flags & TF_NEEDSYN) {
12195 			return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
12196 			    tiwin, thflags, nxt_pkt));
12197 		} else if (tp->t_flags & TF_ACKNOW) {
12198 			ctf_do_dropafterack(m, tp, th, thflags, tlen, &ret_val);
12199 			((struct tcp_rack *)tp->t_fb_ptr)->r_wanted_output = 1;
12200 			return (ret_val);
12201 		} else {
12202 			ctf_do_drop(m, NULL);
12203 			return (0);
12204 		}
12205 	}
12206 	/*
12207 	 * case TCPS_LAST_ACK: Ack processing.
12208 	 */
12209 	if (rack_process_ack(m, th, so, tp, to, tiwin, tlen, &ourfinisacked, thflags, &ret_val)) {
12210 		return (ret_val);
12211 	}
12212 	if (ourfinisacked) {
12213 		tp = tcp_close(tp);
12214 		ctf_do_drop(m, tp);
12215 		return (1);
12216 	}
12217 	if (sbavail(&so->so_snd)) {
12218 		if (ctf_progress_timeout_check(tp, true)) {
12219 			rack_log_progress_event((struct tcp_rack *)tp->t_fb_ptr,
12220 						tp, tick, PROGRESS_DROP, __LINE__);
12221 			ctf_do_dropwithreset_conn(m, tp, th, BANDLIM_RST_OPENPORT, tlen);
12222 			return (1);
12223 		}
12224 	}
12225 	return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
12226 	    tiwin, thflags, nxt_pkt));
12227 }
12228 
12229 /*
12230  * Return value of 1, the TCB is unlocked and most
12231  * likely gone, return value of 0, the TCP is still
12232  * locked.
12233  */
12234 static int
12235 rack_do_fin_wait_2(struct mbuf *m, struct tcphdr *th, struct socket *so,
12236     struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen,
12237     uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos)
12238 {
12239 	int32_t ret_val = 0;
12240 	int32_t ourfinisacked = 0;
12241 	struct tcp_rack *rack;
12242 
12243 	rack = (struct tcp_rack *)tp->t_fb_ptr;
12244 	ctf_calc_rwin(so, tp);
12245 
12246 	/* Reset receive buffer auto scaling when not in bulk receive mode. */
12247 	if ((thflags & TH_RST) ||
12248 	    (tp->t_fin_is_rst && (thflags & TH_FIN)))
12249 		return (__ctf_process_rst(m, th, so, tp,
12250 					  &rack->r_ctl.challenge_ack_ts,
12251 					  &rack->r_ctl.challenge_ack_cnt));
12252 	/*
12253 	 * RFC5961 Section 4.2 Send challenge ACK for any SYN in
12254 	 * synchronized state.
12255 	 */
12256 	if (thflags & TH_SYN) {
12257 		ctf_challenge_ack(m, th, tp, iptos, &ret_val);
12258 		return (ret_val);
12259 	}
12260 	/*
12261 	 * RFC 1323 PAWS: If we have a timestamp reply on this segment and
12262 	 * it's less than ts_recent, drop it.
12263 	 */
12264 	if ((to->to_flags & TOF_TS) != 0 && tp->ts_recent &&
12265 	    TSTMP_LT(to->to_tsval, tp->ts_recent)) {
12266 		if (ctf_ts_check(m, th, tp, tlen, thflags, &ret_val))
12267 			return (ret_val);
12268 	}
12269 	if (_ctf_drop_checks(to, m, th, tp, &tlen, &thflags, &drop_hdrlen, &ret_val,
12270 			      &rack->r_ctl.challenge_ack_ts,
12271 			      &rack->r_ctl.challenge_ack_cnt)) {
12272 		return (ret_val);
12273 	}
12274 	/*
12275 	 * If new data are received on a connection after the user processes
12276 	 * are gone, then RST the other end.
12277 	 */
12278 	if ((tp->t_flags & TF_CLOSED) && tlen &&
12279 	    rack_check_data_after_close(m, tp, &tlen, th, so))
12280 		return (1);
12281 	/*
12282 	 * If last ACK falls within this segment's sequence numbers, record
12283 	 * its timestamp. NOTE: 1) That the test incorporates suggestions
12284 	 * from the latest proposal of the tcplw@cray.com list (Braden
12285 	 * 1993/04/26). 2) That updating only on newer timestamps interferes
12286 	 * with our earlier PAWS tests, so this check should be solely
12287 	 * predicated on the sequence space of this segment. 3) That we
12288 	 * modify the segment boundary check to be Last.ACK.Sent <= SEG.SEQ
12289 	 * + SEG.Len  instead of RFC1323's Last.ACK.Sent < SEG.SEQ +
12290 	 * SEG.Len, This modified check allows us to overcome RFC1323's
12291 	 * limitations as described in Stevens TCP/IP Illustrated Vol. 2
12292 	 * p.869. In such cases, we can still calculate the RTT correctly
12293 	 * when RCV.NXT == Last.ACK.Sent.
12294 	 */
12295 	if ((to->to_flags & TOF_TS) != 0 &&
12296 	    SEQ_LEQ(th->th_seq, tp->last_ack_sent) &&
12297 	    SEQ_LEQ(tp->last_ack_sent, th->th_seq + tlen +
12298 	    ((thflags & (TH_SYN | TH_FIN)) != 0))) {
12299 		tp->ts_recent_age = tcp_ts_getticks();
12300 		tp->ts_recent = to->to_tsval;
12301 	}
12302 	/*
12303 	 * If the ACK bit is off:  if in SYN-RECEIVED state or SENDSYN flag
12304 	 * is on (half-synchronized state), then queue data for later
12305 	 * processing; else drop segment and return.
12306 	 */
12307 	if ((thflags & TH_ACK) == 0) {
12308 		if (tp->t_flags & TF_NEEDSYN) {
12309 			return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
12310 			    tiwin, thflags, nxt_pkt));
12311 		} else if (tp->t_flags & TF_ACKNOW) {
12312 			ctf_do_dropafterack(m, tp, th, thflags, tlen, &ret_val);
12313 			((struct tcp_rack *)tp->t_fb_ptr)->r_wanted_output = 1;
12314 			return (ret_val);
12315 		} else {
12316 			ctf_do_drop(m, NULL);
12317 			return (0);
12318 		}
12319 	}
12320 	/*
12321 	 * Ack processing.
12322 	 */
12323 	if (rack_process_ack(m, th, so, tp, to, tiwin, tlen, &ourfinisacked, thflags, &ret_val)) {
12324 		return (ret_val);
12325 	}
12326 	if (sbavail(&so->so_snd)) {
12327 		if (ctf_progress_timeout_check(tp, true)) {
12328 			rack_log_progress_event((struct tcp_rack *)tp->t_fb_ptr,
12329 						tp, tick, PROGRESS_DROP, __LINE__);
12330 			ctf_do_dropwithreset_conn(m, tp, th, BANDLIM_RST_OPENPORT, tlen);
12331 			return (1);
12332 		}
12333 	}
12334 	return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
12335 	    tiwin, thflags, nxt_pkt));
12336 }
12337 
12338 static void inline
12339 rack_clear_rate_sample(struct tcp_rack *rack)
12340 {
12341 	rack->r_ctl.rack_rs.rs_flags = RACK_RTT_EMPTY;
12342 	rack->r_ctl.rack_rs.rs_rtt_cnt = 0;
12343 	rack->r_ctl.rack_rs.rs_rtt_tot = 0;
12344 }
12345 
12346 static void
12347 rack_set_pace_segments(struct tcpcb *tp, struct tcp_rack *rack, uint32_t line, uint64_t *fill_override)
12348 {
12349 	uint64_t bw_est, rate_wanted;
12350 	int chged = 0;
12351 	uint32_t user_max, orig_min, orig_max;
12352 
12353 	orig_min = rack->r_ctl.rc_pace_min_segs;
12354 	orig_max = rack->r_ctl.rc_pace_max_segs;
12355 	user_max = ctf_fixed_maxseg(tp) * rack->rc_user_set_max_segs;
12356 	if (ctf_fixed_maxseg(tp) != rack->r_ctl.rc_pace_min_segs)
12357 		chged = 1;
12358 	rack->r_ctl.rc_pace_min_segs = ctf_fixed_maxseg(tp);
12359 	if (rack->use_fixed_rate || rack->rc_force_max_seg) {
12360 		if (user_max != rack->r_ctl.rc_pace_max_segs)
12361 			chged = 1;
12362 	}
12363 	if (rack->rc_force_max_seg) {
12364 		rack->r_ctl.rc_pace_max_segs = user_max;
12365 	} else if (rack->use_fixed_rate) {
12366 		bw_est = rack_get_bw(rack);
12367 		if ((rack->r_ctl.crte == NULL) ||
12368 		    (bw_est != rack->r_ctl.crte->rate)) {
12369 			rack->r_ctl.rc_pace_max_segs = user_max;
12370 		} else {
12371 			/* We are pacing right at the hardware rate */
12372 			uint32_t segsiz;
12373 
12374 			segsiz = min(ctf_fixed_maxseg(tp),
12375 				     rack->r_ctl.rc_pace_min_segs);
12376 			rack->r_ctl.rc_pace_max_segs = tcp_get_pacing_burst_size(
12377 				                           tp, bw_est, segsiz, 0,
12378 							   rack->r_ctl.crte, NULL);
12379 		}
12380 	} else if (rack->rc_always_pace) {
12381 		if (rack->r_ctl.gp_bw ||
12382 #ifdef NETFLIX_PEAKRATE
12383 		    rack->rc_tp->t_maxpeakrate ||
12384 #endif
12385 		    rack->r_ctl.init_rate) {
12386 			/* We have a rate of some sort set */
12387 			uint32_t  orig;
12388 
12389 			bw_est = rack_get_bw(rack);
12390 			orig = rack->r_ctl.rc_pace_max_segs;
12391 			if (fill_override)
12392 				rate_wanted = *fill_override;
12393 			else
12394 				rate_wanted = rack_get_output_bw(rack, bw_est, NULL, NULL);
12395 			if (rate_wanted) {
12396 				/* We have something */
12397 				rack->r_ctl.rc_pace_max_segs = rack_get_pacing_len(rack,
12398 										   rate_wanted,
12399 										   ctf_fixed_maxseg(rack->rc_tp));
12400 			} else
12401 				rack->r_ctl.rc_pace_max_segs = rack->r_ctl.rc_pace_min_segs;
12402 			if (orig != rack->r_ctl.rc_pace_max_segs)
12403 				chged = 1;
12404 		} else if ((rack->r_ctl.gp_bw == 0) &&
12405 			   (rack->r_ctl.rc_pace_max_segs == 0)) {
12406 			/*
12407 			 * If we have nothing limit us to bursting
12408 			 * out IW sized pieces.
12409 			 */
12410 			chged = 1;
12411 			rack->r_ctl.rc_pace_max_segs = rc_init_window(rack);
12412 		}
12413 	}
12414 	if (rack->r_ctl.rc_pace_max_segs > PACE_MAX_IP_BYTES) {
12415 		chged = 1;
12416 		rack->r_ctl.rc_pace_max_segs = PACE_MAX_IP_BYTES;
12417 	}
12418 	if (chged)
12419 		rack_log_type_pacing_sizes(tp, rack, orig_min, orig_max, line, 2);
12420 }
12421 
12422 
12423 static void
12424 rack_init_fsb_block(struct tcpcb *tp, struct tcp_rack *rack)
12425 {
12426 #ifdef INET6
12427 	struct ip6_hdr *ip6 = NULL;
12428 #endif
12429 #ifdef INET
12430 	struct ip *ip = NULL;
12431 #endif
12432 	struct udphdr *udp = NULL;
12433 
12434 	/* Ok lets fill in the fast block, it can only be used with no IP options! */
12435 #ifdef INET6
12436 	if (rack->r_is_v6) {
12437 		rack->r_ctl.fsb.tcp_ip_hdr_len = sizeof(struct ip6_hdr) + sizeof(struct tcphdr);
12438 		ip6 = (struct ip6_hdr *)rack->r_ctl.fsb.tcp_ip_hdr;
12439 		if (tp->t_port) {
12440 			rack->r_ctl.fsb.tcp_ip_hdr_len += sizeof(struct udphdr);
12441 			udp = (struct udphdr *)((caddr_t)ip6 + sizeof(struct ip6_hdr));
12442 			udp->uh_sport = htons(V_tcp_udp_tunneling_port);
12443 			udp->uh_dport = tp->t_port;
12444 			rack->r_ctl.fsb.udp = udp;
12445 			rack->r_ctl.fsb.th = (struct tcphdr *)(udp + 1);
12446 		} else
12447 		{
12448 			rack->r_ctl.fsb.th = (struct tcphdr *)(ip6 + 1);
12449 			rack->r_ctl.fsb.udp = NULL;
12450 		}
12451 		tcpip_fillheaders(rack->rc_inp,
12452 				  tp->t_port,
12453 				  ip6, rack->r_ctl.fsb.th);
12454 	} else
12455 #endif				/* INET6 */
12456 	{
12457 		rack->r_ctl.fsb.tcp_ip_hdr_len = sizeof(struct tcpiphdr);
12458 		ip = (struct ip *)rack->r_ctl.fsb.tcp_ip_hdr;
12459 		if (tp->t_port) {
12460 			rack->r_ctl.fsb.tcp_ip_hdr_len += sizeof(struct udphdr);
12461 			udp = (struct udphdr *)((caddr_t)ip + sizeof(struct ip));
12462 			udp->uh_sport = htons(V_tcp_udp_tunneling_port);
12463 			udp->uh_dport = tp->t_port;
12464 			rack->r_ctl.fsb.udp = udp;
12465 			rack->r_ctl.fsb.th = (struct tcphdr *)(udp + 1);
12466 		} else
12467 		{
12468 			rack->r_ctl.fsb.udp = NULL;
12469 			rack->r_ctl.fsb.th = (struct tcphdr *)(ip + 1);
12470 		}
12471 		tcpip_fillheaders(rack->rc_inp,
12472 				  tp->t_port,
12473 				  ip, rack->r_ctl.fsb.th);
12474 	}
12475 	rack->r_fsb_inited = 1;
12476 }
12477 
12478 static int
12479 rack_init_fsb(struct tcpcb *tp, struct tcp_rack *rack)
12480 {
12481 	/*
12482 	 * Allocate the larger of spaces V6 if available else just
12483 	 * V4 and include udphdr (overbook)
12484 	 */
12485 #ifdef INET6
12486 	rack->r_ctl.fsb.tcp_ip_hdr_len = sizeof(struct ip6_hdr) + sizeof(struct tcphdr) + sizeof(struct udphdr);
12487 #else
12488 	rack->r_ctl.fsb.tcp_ip_hdr_len = sizeof(struct tcpiphdr) + sizeof(struct udphdr);
12489 #endif
12490 	rack->r_ctl.fsb.tcp_ip_hdr = malloc(rack->r_ctl.fsb.tcp_ip_hdr_len,
12491 					    M_TCPFSB, M_NOWAIT|M_ZERO);
12492 	if (rack->r_ctl.fsb.tcp_ip_hdr == NULL) {
12493 		return (ENOMEM);
12494 	}
12495 	rack->r_fsb_inited = 0;
12496 	return (0);
12497 }
12498 
12499 static int
12500 rack_init(struct tcpcb *tp)
12501 {
12502 	struct inpcb *inp = tptoinpcb(tp);
12503 	struct tcp_rack *rack = NULL;
12504 #ifdef INVARIANTS
12505 	struct rack_sendmap *insret;
12506 #endif
12507 	uint32_t iwin, snt, us_cts;
12508 	int err;
12509 
12510 	tp->t_fb_ptr = uma_zalloc(rack_pcb_zone, M_NOWAIT);
12511 	if (tp->t_fb_ptr == NULL) {
12512 		/*
12513 		 * We need to allocate memory but cant. The INP and INP_INFO
12514 		 * locks and they are recursive (happens during setup. So a
12515 		 * scheme to drop the locks fails :(
12516 		 *
12517 		 */
12518 		return (ENOMEM);
12519 	}
12520 	memset(tp->t_fb_ptr, 0, sizeof(struct tcp_rack));
12521 
12522 	rack = (struct tcp_rack *)tp->t_fb_ptr;
12523 	RB_INIT(&rack->r_ctl.rc_mtree);
12524 	TAILQ_INIT(&rack->r_ctl.rc_free);
12525 	TAILQ_INIT(&rack->r_ctl.rc_tmap);
12526 	rack->rc_tp = tp;
12527 	rack->rc_inp = inp;
12528 	/* Set the flag */
12529 	rack->r_is_v6 = (inp->inp_vflag & INP_IPV6) != 0;
12530 	/* Probably not needed but lets be sure */
12531 	rack_clear_rate_sample(rack);
12532 	/*
12533 	 * Save off the default values, socket options will poke
12534 	 * at these if pacing is not on or we have not yet
12535 	 * reached where pacing is on (gp_ready/fixed enabled).
12536 	 * When they get set into the CC module (when gp_ready
12537 	 * is enabled or we enable fixed) then we will set these
12538 	 * values into the CC and place in here the old values
12539 	 * so we have a restoral. Then we will set the flag
12540 	 * rc_pacing_cc_set. That way whenever we turn off pacing
12541 	 * or switch off this stack, we will know to go restore
12542 	 * the saved values.
12543 	 */
12544 	rack->r_ctl.rc_saved_beta.beta = V_newreno_beta_ecn;
12545 	rack->r_ctl.rc_saved_beta.beta_ecn = V_newreno_beta_ecn;
12546 	/* We want abe like behavior as well */
12547 	rack->r_ctl.rc_saved_beta.newreno_flags |= CC_NEWRENO_BETA_ECN_ENABLED;
12548 	rack->r_ctl.rc_reorder_fade = rack_reorder_fade;
12549 	rack->rc_allow_data_af_clo = rack_ignore_data_after_close;
12550 	rack->r_ctl.rc_tlp_threshold = rack_tlp_thresh;
12551 	rack->r_ctl.roundends = tp->snd_max;
12552 	if (use_rack_rr)
12553 		rack->use_rack_rr = 1;
12554 	if (V_tcp_delack_enabled)
12555 		tp->t_delayed_ack = 1;
12556 	else
12557 		tp->t_delayed_ack = 0;
12558 #ifdef TCP_ACCOUNTING
12559 	if (rack_tcp_accounting) {
12560 		tp->t_flags2 |= TF2_TCP_ACCOUNTING;
12561 	}
12562 #endif
12563 	if (rack_enable_shared_cwnd)
12564 		rack->rack_enable_scwnd = 1;
12565 	rack->rc_user_set_max_segs = rack_hptsi_segments;
12566 	rack->rc_force_max_seg = 0;
12567 	if (rack_use_imac_dack)
12568 		rack->rc_dack_mode = 1;
12569 	TAILQ_INIT(&rack->r_ctl.opt_list);
12570 	rack->r_ctl.rc_reorder_shift = rack_reorder_thresh;
12571 	rack->r_ctl.rc_pkt_delay = rack_pkt_delay;
12572 	rack->r_ctl.rc_tlp_cwnd_reduce = rack_lower_cwnd_at_tlp;
12573 	rack->r_ctl.rc_lowest_us_rtt = 0xffffffff;
12574 	rack->r_ctl.rc_highest_us_rtt = 0;
12575 	rack->r_ctl.bw_rate_cap = rack_bw_rate_cap;
12576 	rack->r_ctl.timer_slop = TICKS_2_USEC(tcp_rexmit_slop);
12577 	if (rack_use_cmp_acks)
12578 		rack->r_use_cmp_ack = 1;
12579 	if (rack_disable_prr)
12580 		rack->rack_no_prr = 1;
12581 	if (rack_gp_no_rec_chg)
12582 		rack->rc_gp_no_rec_chg = 1;
12583 	if (rack_pace_every_seg && tcp_can_enable_pacing()) {
12584 		rack->rc_always_pace = 1;
12585 		if (rack->use_fixed_rate || rack->gp_ready)
12586 			rack_set_cc_pacing(rack);
12587 	} else
12588 		rack->rc_always_pace = 0;
12589 	if (rack_enable_mqueue_for_nonpaced || rack->r_use_cmp_ack)
12590 		rack->r_mbuf_queue = 1;
12591 	else
12592 		rack->r_mbuf_queue = 0;
12593 	if  (rack->r_mbuf_queue || rack->rc_always_pace || rack->r_use_cmp_ack)
12594 		inp->inp_flags2 |= INP_SUPPORTS_MBUFQ;
12595 	else
12596 		inp->inp_flags2 &= ~INP_SUPPORTS_MBUFQ;
12597 	rack_set_pace_segments(tp, rack, __LINE__, NULL);
12598 	if (rack_limits_scwnd)
12599 		rack->r_limit_scw = 1;
12600 	else
12601 		rack->r_limit_scw = 0;
12602 	rack->rc_labc = V_tcp_abc_l_var;
12603 	rack->r_ctl.rc_high_rwnd = tp->snd_wnd;
12604 	rack->r_ctl.cwnd_to_use = tp->snd_cwnd;
12605 	rack->r_ctl.rc_rate_sample_method = rack_rate_sample_method;
12606 	rack->rack_tlp_threshold_use = rack_tlp_threshold_use;
12607 	rack->r_ctl.rc_prr_sendalot = rack_send_a_lot_in_prr;
12608 	rack->r_ctl.rc_min_to = rack_min_to;
12609 	microuptime(&rack->r_ctl.act_rcv_time);
12610 	rack->r_ctl.rc_last_time_decay = rack->r_ctl.act_rcv_time;
12611 	rack->rc_init_win = rack_default_init_window;
12612 	rack->r_ctl.rack_per_of_gp_ss = rack_per_of_gp_ss;
12613 	if (rack_hw_up_only)
12614 		rack->r_up_only = 1;
12615 	if (rack_do_dyn_mul) {
12616 		/* When dynamic adjustment is on CA needs to start at 100% */
12617 		rack->rc_gp_dyn_mul = 1;
12618 		if (rack_do_dyn_mul >= 100)
12619 			rack->r_ctl.rack_per_of_gp_ca = rack_do_dyn_mul;
12620 	} else
12621 		rack->r_ctl.rack_per_of_gp_ca = rack_per_of_gp_ca;
12622 	rack->r_ctl.rack_per_of_gp_rec = rack_per_of_gp_rec;
12623 	rack->r_ctl.rack_per_of_gp_probertt = rack_per_of_gp_probertt;
12624 	rack->r_ctl.rc_tlp_rxt_last_time = tcp_tv_to_mssectick(&rack->r_ctl.act_rcv_time);
12625 	setup_time_filter_small(&rack->r_ctl.rc_gp_min_rtt, FILTER_TYPE_MIN,
12626 				rack_probertt_filter_life);
12627 	us_cts = tcp_tv_to_usectick(&rack->r_ctl.act_rcv_time);
12628 	rack->r_ctl.rc_lower_rtt_us_cts = us_cts;
12629 	rack->r_ctl.rc_time_of_last_probertt = us_cts;
12630 	rack->r_ctl.challenge_ack_ts = tcp_ts_getticks();
12631 	rack->r_ctl.rc_time_probertt_starts = 0;
12632 	if (rack_dsack_std_based & 0x1) {
12633 		/* Basically this means all rack timers are at least (srtt + 1/4 srtt) */
12634 		rack->rc_rack_tmr_std_based = 1;
12635 	}
12636 	if (rack_dsack_std_based & 0x2) {
12637 		/* Basically this means  rack timers are extended based on dsack by up to (2 * srtt) */
12638 		rack->rc_rack_use_dsack = 1;
12639 	}
12640 	/* We require at least one measurement, even if the sysctl is 0 */
12641 	if (rack_req_measurements)
12642 		rack->r_ctl.req_measurements = rack_req_measurements;
12643 	else
12644 		rack->r_ctl.req_measurements = 1;
12645 	if (rack_enable_hw_pacing)
12646 		rack->rack_hdw_pace_ena = 1;
12647 	if (rack_hw_rate_caps)
12648 		rack->r_rack_hw_rate_caps = 1;
12649 	/* Do we force on detection? */
12650 #ifdef NETFLIX_EXP_DETECTION
12651 	if (tcp_force_detection)
12652 		rack->do_detection = 1;
12653 	else
12654 #endif
12655 		rack->do_detection = 0;
12656 	if (rack_non_rxt_use_cr)
12657 		rack->rack_rec_nonrxt_use_cr = 1;
12658 	err = rack_init_fsb(tp, rack);
12659 	if (err) {
12660 		uma_zfree(rack_pcb_zone, tp->t_fb_ptr);
12661 		tp->t_fb_ptr = NULL;
12662 		return (err);
12663 	}
12664 	if (tp->snd_una != tp->snd_max) {
12665 		/* Create a send map for the current outstanding data */
12666 		struct rack_sendmap *rsm;
12667 
12668 		rsm = rack_alloc(rack);
12669 		if (rsm == NULL) {
12670 			uma_zfree(rack_pcb_zone, tp->t_fb_ptr);
12671 			tp->t_fb_ptr = NULL;
12672 			return (ENOMEM);
12673 		}
12674 		rsm->r_no_rtt_allowed = 1;
12675 		rsm->r_tim_lastsent[0] = rack_to_usec_ts(&rack->r_ctl.act_rcv_time);
12676 		rsm->r_rtr_cnt = 1;
12677 		rsm->r_rtr_bytes = 0;
12678 		if (tp->t_flags & TF_SENTFIN)
12679 			rsm->r_flags |= RACK_HAS_FIN;
12680 		if ((tp->snd_una == tp->iss) &&
12681 		    !TCPS_HAVEESTABLISHED(tp->t_state))
12682 			rsm->r_flags |= RACK_HAS_SYN;
12683 		rsm->r_start = tp->snd_una;
12684 		rsm->r_end = tp->snd_max;
12685 		rsm->r_dupack = 0;
12686 		if (rack->rc_inp->inp_socket->so_snd.sb_mb != NULL) {
12687 			rsm->m = sbsndmbuf(&rack->rc_inp->inp_socket->so_snd, 0, &rsm->soff);
12688 			if (rsm->m)
12689 				rsm->orig_m_len = rsm->m->m_len;
12690 			else
12691 				rsm->orig_m_len = 0;
12692 		} else {
12693 			/*
12694 			 * This can happen if we have a stand-alone FIN or
12695 			 *  SYN.
12696 			 */
12697 			rsm->m = NULL;
12698 			rsm->orig_m_len = 0;
12699 			rsm->soff = 0;
12700 		}
12701 #ifndef INVARIANTS
12702 		(void)RB_INSERT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm);
12703 #else
12704 		insret = RB_INSERT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm);
12705 		if (insret != NULL) {
12706 			panic("Insert in rb tree fails ret:%p rack:%p rsm:%p",
12707 			      insret, rack, rsm);
12708 		}
12709 #endif
12710 		TAILQ_INSERT_TAIL(&rack->r_ctl.rc_tmap, rsm, r_tnext);
12711 		rsm->r_in_tmap = 1;
12712 	}
12713 	/*
12714 	 * Timers in Rack are kept in microseconds so lets
12715 	 * convert any initial incoming variables
12716 	 * from ticks into usecs. Note that we
12717 	 * also change the values of t_srtt and t_rttvar, if
12718 	 * they are non-zero. They are kept with a 5
12719 	 * bit decimal so we have to carefully convert
12720 	 * these to get the full precision.
12721 	 */
12722 	rack_convert_rtts(tp);
12723 	tp->t_rttlow = TICKS_2_USEC(tp->t_rttlow);
12724 	if (rack_do_hystart) {
12725 		tp->ccv->flags |= CCF_HYSTART_ALLOWED;
12726 		if (rack_do_hystart > 1)
12727 			tp->ccv->flags |= CCF_HYSTART_CAN_SH_CWND;
12728 		if (rack_do_hystart > 2)
12729 			tp->ccv->flags |= CCF_HYSTART_CONS_SSTH;
12730 	}
12731 	if (rack_def_profile)
12732 		rack_set_profile(rack, rack_def_profile);
12733 	/* Cancel the GP measurement in progress */
12734 	tp->t_flags &= ~TF_GPUTINPROG;
12735 	if (SEQ_GT(tp->snd_max, tp->iss))
12736 		snt = tp->snd_max - tp->iss;
12737 	else
12738 		snt = 0;
12739 	iwin = rc_init_window(rack);
12740 	if (snt < iwin) {
12741 		/* We are not past the initial window
12742 		 * so we need to make sure cwnd is
12743 		 * correct.
12744 		 */
12745 		if (tp->snd_cwnd < iwin)
12746 			tp->snd_cwnd = iwin;
12747 		/*
12748 		 * If we are within the initial window
12749 		 * we want ssthresh to be unlimited. Setting
12750 		 * it to the rwnd (which the default stack does
12751 		 * and older racks) is not really a good idea
12752 		 * since we want to be in SS and grow both the
12753 		 * cwnd and the rwnd (via dynamic rwnd growth). If
12754 		 * we set it to the rwnd then as the peer grows its
12755 		 * rwnd we will be stuck in CA and never hit SS.
12756 		 *
12757 		 * Its far better to raise it up high (this takes the
12758 		 * risk that there as been a loss already, probably
12759 		 * we should have an indicator in all stacks of loss
12760 		 * but we don't), but considering the normal use this
12761 		 * is a risk worth taking. The consequences of not
12762 		 * hitting SS are far worse than going one more time
12763 		 * into it early on (before we have sent even a IW).
12764 		 * It is highly unlikely that we will have had a loss
12765 		 * before getting the IW out.
12766 		 */
12767 		tp->snd_ssthresh = 0xffffffff;
12768 	}
12769 	rack_stop_all_timers(tp);
12770 	/* Lets setup the fsb block */
12771 	rack_start_hpts_timer(rack, tp, tcp_get_usecs(NULL), 0, 0, 0);
12772 	rack_log_rtt_shrinks(rack,  us_cts,  tp->t_rxtcur,
12773 			     __LINE__, RACK_RTTS_INIT);
12774 	return (0);
12775 }
12776 
12777 static int
12778 rack_handoff_ok(struct tcpcb *tp)
12779 {
12780 	if ((tp->t_state == TCPS_CLOSED) ||
12781 	    (tp->t_state == TCPS_LISTEN)) {
12782 		/* Sure no problem though it may not stick */
12783 		return (0);
12784 	}
12785 	if ((tp->t_state == TCPS_SYN_SENT) ||
12786 	    (tp->t_state == TCPS_SYN_RECEIVED)) {
12787 		/*
12788 		 * We really don't know if you support sack,
12789 		 * you have to get to ESTAB or beyond to tell.
12790 		 */
12791 		return (EAGAIN);
12792 	}
12793 	if ((tp->t_flags & TF_SENTFIN) && ((tp->snd_max - tp->snd_una) > 1)) {
12794 		/*
12795 		 * Rack will only send a FIN after all data is acknowledged.
12796 		 * So in this case we have more data outstanding. We can't
12797 		 * switch stacks until either all data and only the FIN
12798 		 * is left (in which case rack_init() now knows how
12799 		 * to deal with that) <or> all is acknowledged and we
12800 		 * are only left with incoming data, though why you
12801 		 * would want to switch to rack after all data is acknowledged
12802 		 * I have no idea (rrs)!
12803 		 */
12804 		return (EAGAIN);
12805 	}
12806 	if ((tp->t_flags & TF_SACK_PERMIT) || rack_sack_not_required){
12807 		return (0);
12808 	}
12809 	/*
12810 	 * If we reach here we don't do SACK on this connection so we can
12811 	 * never do rack.
12812 	 */
12813 	return (EINVAL);
12814 }
12815 
12816 
12817 static void
12818 rack_fini(struct tcpcb *tp, int32_t tcb_is_purged)
12819 {
12820 	struct inpcb *inp = tptoinpcb(tp);
12821 
12822 	if (tp->t_fb_ptr) {
12823 		struct tcp_rack *rack;
12824 		struct rack_sendmap *rsm, *nrsm;
12825 #ifdef INVARIANTS
12826 		struct rack_sendmap *rm;
12827 #endif
12828 
12829 		rack = (struct tcp_rack *)tp->t_fb_ptr;
12830 		if (tp->t_in_pkt) {
12831 			/*
12832 			 * It is unsafe to process the packets since a
12833 			 * reset may be lurking in them (its rare but it
12834 			 * can occur). If we were to find a RST, then we
12835 			 * would end up dropping the connection and the
12836 			 * INP lock, so when we return the caller (tcp_usrreq)
12837 			 * will blow up when it trys to unlock the inp.
12838 			 */
12839 			struct mbuf *save, *m;
12840 
12841 			m = tp->t_in_pkt;
12842 			tp->t_in_pkt = NULL;
12843 			tp->t_tail_pkt = NULL;
12844 			while (m) {
12845 				save = m->m_nextpkt;
12846 				m->m_nextpkt = NULL;
12847 				m_freem(m);
12848 				m = save;
12849 			}
12850 		}
12851 		tp->t_flags &= ~TF_FORCEDATA;
12852 #ifdef NETFLIX_SHARED_CWND
12853 		if (rack->r_ctl.rc_scw) {
12854 			uint32_t limit;
12855 
12856 			if (rack->r_limit_scw)
12857 				limit = max(1, rack->r_ctl.rc_lowest_us_rtt);
12858 			else
12859 				limit = 0;
12860 			tcp_shared_cwnd_free_full(tp, rack->r_ctl.rc_scw,
12861 						  rack->r_ctl.rc_scw_index,
12862 						  limit);
12863 			rack->r_ctl.rc_scw = NULL;
12864 		}
12865 #endif
12866 		if (rack->r_ctl.fsb.tcp_ip_hdr) {
12867 			free(rack->r_ctl.fsb.tcp_ip_hdr, M_TCPFSB);
12868 			rack->r_ctl.fsb.tcp_ip_hdr = NULL;
12869 			rack->r_ctl.fsb.th = NULL;
12870 		}
12871 		/* Convert back to ticks, with  */
12872 		if (tp->t_srtt > 1) {
12873 			uint32_t val, frac;
12874 
12875 			val = USEC_2_TICKS(tp->t_srtt);
12876 			frac = tp->t_srtt % (HPTS_USEC_IN_SEC / hz);
12877 			tp->t_srtt = val << TCP_RTT_SHIFT;
12878 			/*
12879 			 * frac is the fractional part here is left
12880 			 * over from converting to hz and shifting.
12881 			 * We need to convert this to the 5 bit
12882 			 * remainder.
12883 			 */
12884 			if (frac) {
12885 				if (hz == 1000) {
12886 					frac = (((uint64_t)frac *  (uint64_t)TCP_RTT_SCALE) / (uint64_t)HPTS_USEC_IN_MSEC);
12887 				} else {
12888 					frac = (((uint64_t)frac * (uint64_t)(hz) * (uint64_t)TCP_RTT_SCALE) /(uint64_t)HPTS_USEC_IN_SEC);
12889 				}
12890 				tp->t_srtt += frac;
12891 			}
12892 		}
12893 		if (tp->t_rttvar) {
12894 			uint32_t val, frac;
12895 
12896 			val = USEC_2_TICKS(tp->t_rttvar);
12897 			frac = tp->t_srtt % (HPTS_USEC_IN_SEC / hz);
12898 			tp->t_rttvar = val <<  TCP_RTTVAR_SHIFT;
12899 			/*
12900 			 * frac is the fractional part here is left
12901 			 * over from converting to hz and shifting.
12902 			 * We need to convert this to the 5 bit
12903 			 * remainder.
12904 			 */
12905 			if (frac) {
12906 				if (hz == 1000) {
12907 					frac = (((uint64_t)frac *  (uint64_t)TCP_RTT_SCALE) / (uint64_t)HPTS_USEC_IN_MSEC);
12908 				} else {
12909 					frac = (((uint64_t)frac * (uint64_t)(hz) * (uint64_t)TCP_RTT_SCALE) /(uint64_t)HPTS_USEC_IN_SEC);
12910 				}
12911 				tp->t_rttvar += frac;
12912 			}
12913 		}
12914 		tp->t_rxtcur = USEC_2_TICKS(tp->t_rxtcur);
12915 		tp->t_rttlow = USEC_2_TICKS(tp->t_rttlow);
12916 		if (rack->rc_always_pace) {
12917 			tcp_decrement_paced_conn();
12918 			rack_undo_cc_pacing(rack);
12919 			rack->rc_always_pace = 0;
12920 		}
12921 		/* Clean up any options if they were not applied */
12922 		while (!TAILQ_EMPTY(&rack->r_ctl.opt_list)) {
12923 			struct deferred_opt_list *dol;
12924 
12925 			dol = TAILQ_FIRST(&rack->r_ctl.opt_list);
12926 			TAILQ_REMOVE(&rack->r_ctl.opt_list, dol, next);
12927 			free(dol, M_TCPDO);
12928 		}
12929 		/* rack does not use force data but other stacks may clear it */
12930 		if (rack->r_ctl.crte != NULL) {
12931 			tcp_rel_pacing_rate(rack->r_ctl.crte, tp);
12932 			rack->rack_hdrw_pacing = 0;
12933 			rack->r_ctl.crte = NULL;
12934 		}
12935 #ifdef TCP_BLACKBOX
12936 		tcp_log_flowend(tp);
12937 #endif
12938 		RB_FOREACH_SAFE(rsm, rack_rb_tree_head, &rack->r_ctl.rc_mtree, nrsm) {
12939 #ifndef INVARIANTS
12940 			(void)RB_REMOVE(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm);
12941 #else
12942 			rm = RB_REMOVE(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm);
12943 			if (rm != rsm) {
12944 				panic("At fini, rack:%p rsm:%p rm:%p",
12945 				      rack, rsm, rm);
12946 			}
12947 #endif
12948 			uma_zfree(rack_zone, rsm);
12949 		}
12950 		rsm = TAILQ_FIRST(&rack->r_ctl.rc_free);
12951 		while (rsm) {
12952 			TAILQ_REMOVE(&rack->r_ctl.rc_free, rsm, r_tnext);
12953 			uma_zfree(rack_zone, rsm);
12954 			rsm = TAILQ_FIRST(&rack->r_ctl.rc_free);
12955 		}
12956 		rack->rc_free_cnt = 0;
12957 		uma_zfree(rack_pcb_zone, tp->t_fb_ptr);
12958 		tp->t_fb_ptr = NULL;
12959 	}
12960 	inp->inp_flags2 &= ~INP_SUPPORTS_MBUFQ;
12961 	inp->inp_flags2 &= ~INP_MBUF_QUEUE_READY;
12962 	inp->inp_flags2 &= ~INP_DONT_SACK_QUEUE;
12963 	inp->inp_flags2 &= ~INP_MBUF_ACKCMP;
12964 	/* Cancel the GP measurement in progress */
12965 	tp->t_flags &= ~TF_GPUTINPROG;
12966 	inp->inp_flags2 &= ~INP_MBUF_L_ACKS;
12967 	/* Make sure snd_nxt is correctly set */
12968 	tp->snd_nxt = tp->snd_max;
12969 }
12970 
12971 static void
12972 rack_set_state(struct tcpcb *tp, struct tcp_rack *rack)
12973 {
12974 	if ((rack->r_state == TCPS_CLOSED) && (tp->t_state != TCPS_CLOSED)) {
12975 		rack->r_is_v6 = (tptoinpcb(tp)->inp_vflag & INP_IPV6) != 0;
12976 	}
12977 	switch (tp->t_state) {
12978 	case TCPS_SYN_SENT:
12979 		rack->r_state = TCPS_SYN_SENT;
12980 		rack->r_substate = rack_do_syn_sent;
12981 		break;
12982 	case TCPS_SYN_RECEIVED:
12983 		rack->r_state = TCPS_SYN_RECEIVED;
12984 		rack->r_substate = rack_do_syn_recv;
12985 		break;
12986 	case TCPS_ESTABLISHED:
12987 		rack_set_pace_segments(tp, rack, __LINE__, NULL);
12988 		rack->r_state = TCPS_ESTABLISHED;
12989 		rack->r_substate = rack_do_established;
12990 		break;
12991 	case TCPS_CLOSE_WAIT:
12992 		rack_set_pace_segments(tp, rack, __LINE__, NULL);
12993 		rack->r_state = TCPS_CLOSE_WAIT;
12994 		rack->r_substate = rack_do_close_wait;
12995 		break;
12996 	case TCPS_FIN_WAIT_1:
12997 		rack_set_pace_segments(tp, rack, __LINE__, NULL);
12998 		rack->r_state = TCPS_FIN_WAIT_1;
12999 		rack->r_substate = rack_do_fin_wait_1;
13000 		break;
13001 	case TCPS_CLOSING:
13002 		rack_set_pace_segments(tp, rack, __LINE__, NULL);
13003 		rack->r_state = TCPS_CLOSING;
13004 		rack->r_substate = rack_do_closing;
13005 		break;
13006 	case TCPS_LAST_ACK:
13007 		rack_set_pace_segments(tp, rack, __LINE__, NULL);
13008 		rack->r_state = TCPS_LAST_ACK;
13009 		rack->r_substate = rack_do_lastack;
13010 		break;
13011 	case TCPS_FIN_WAIT_2:
13012 		rack_set_pace_segments(tp, rack, __LINE__, NULL);
13013 		rack->r_state = TCPS_FIN_WAIT_2;
13014 		rack->r_substate = rack_do_fin_wait_2;
13015 		break;
13016 	case TCPS_LISTEN:
13017 	case TCPS_CLOSED:
13018 	case TCPS_TIME_WAIT:
13019 	default:
13020 		break;
13021 	};
13022 	if (rack->r_use_cmp_ack && TCPS_HAVEESTABLISHED(tp->t_state))
13023 		rack->rc_inp->inp_flags2 |= INP_MBUF_ACKCMP;
13024 
13025 }
13026 
13027 static void
13028 rack_timer_audit(struct tcpcb *tp, struct tcp_rack *rack, struct sockbuf *sb)
13029 {
13030 	/*
13031 	 * We received an ack, and then did not
13032 	 * call send or were bounced out due to the
13033 	 * hpts was running. Now a timer is up as well, is
13034 	 * it the right timer?
13035 	 */
13036 	struct rack_sendmap *rsm;
13037 	int tmr_up;
13038 
13039 	tmr_up = rack->r_ctl.rc_hpts_flags & PACE_TMR_MASK;
13040 	if (rack->rc_in_persist && (tmr_up == PACE_TMR_PERSIT))
13041 		return;
13042 	rsm = TAILQ_FIRST(&rack->r_ctl.rc_tmap);
13043 	if (((rsm == NULL) || (tp->t_state < TCPS_ESTABLISHED)) &&
13044 	    (tmr_up == PACE_TMR_RXT)) {
13045 		/* Should be an RXT */
13046 		return;
13047 	}
13048 	if (rsm == NULL) {
13049 		/* Nothing outstanding? */
13050 		if (tp->t_flags & TF_DELACK) {
13051 			if (tmr_up == PACE_TMR_DELACK)
13052 				/* We are supposed to have delayed ack up and we do */
13053 				return;
13054 		} else if (sbavail(&tptosocket(tp)->so_snd) && (tmr_up == PACE_TMR_RXT)) {
13055 			/*
13056 			 * if we hit enobufs then we would expect the possibility
13057 			 * of nothing outstanding and the RXT up (and the hptsi timer).
13058 			 */
13059 			return;
13060 		} else if (((V_tcp_always_keepalive ||
13061 			     rack->rc_inp->inp_socket->so_options & SO_KEEPALIVE) &&
13062 			    (tp->t_state <= TCPS_CLOSING)) &&
13063 			   (tmr_up == PACE_TMR_KEEP) &&
13064 			   (tp->snd_max == tp->snd_una)) {
13065 			/* We should have keep alive up and we do */
13066 			return;
13067 		}
13068 	}
13069 	if (SEQ_GT(tp->snd_max, tp->snd_una) &&
13070 		   ((tmr_up == PACE_TMR_TLP) ||
13071 		    (tmr_up == PACE_TMR_RACK) ||
13072 		    (tmr_up == PACE_TMR_RXT))) {
13073 		/*
13074 		 * Either a Rack, TLP or RXT is fine if  we
13075 		 * have outstanding data.
13076 		 */
13077 		return;
13078 	} else if (tmr_up == PACE_TMR_DELACK) {
13079 		/*
13080 		 * If the delayed ack was going to go off
13081 		 * before the rtx/tlp/rack timer were going to
13082 		 * expire, then that would be the timer in control.
13083 		 * Note we don't check the time here trusting the
13084 		 * code is correct.
13085 		 */
13086 		return;
13087 	}
13088 	/*
13089 	 * Ok the timer originally started is not what we want now.
13090 	 * We will force the hpts to be stopped if any, and restart
13091 	 * with the slot set to what was in the saved slot.
13092 	 */
13093 	if (tcp_in_hpts(rack->rc_inp)) {
13094 		if (rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT) {
13095 			uint32_t us_cts;
13096 
13097 			us_cts = tcp_get_usecs(NULL);
13098 			if (TSTMP_GT(rack->r_ctl.rc_last_output_to, us_cts)) {
13099 				rack->r_early = 1;
13100 				rack->r_ctl.rc_agg_early += (rack->r_ctl.rc_last_output_to - us_cts);
13101 			}
13102 			rack->r_ctl.rc_hpts_flags &= ~PACE_PKT_OUTPUT;
13103 		}
13104 		tcp_hpts_remove(rack->rc_inp);
13105 	}
13106 	rack_timer_cancel(tp, rack, rack->r_ctl.rc_rcvtime, __LINE__);
13107 	rack_start_hpts_timer(rack, tp, tcp_get_usecs(NULL), 0, 0, 0);
13108 }
13109 
13110 
13111 static void
13112 rack_do_win_updates(struct tcpcb *tp, struct tcp_rack *rack, uint32_t tiwin, uint32_t seq, uint32_t ack, uint32_t cts, uint32_t high_seq)
13113 {
13114 	if ((SEQ_LT(tp->snd_wl1, seq) ||
13115 	    (tp->snd_wl1 == seq && (SEQ_LT(tp->snd_wl2, ack) ||
13116 	    (tp->snd_wl2 == ack && tiwin > tp->snd_wnd))))) {
13117 		/* keep track of pure window updates */
13118 		if ((tp->snd_wl2 == ack) && (tiwin > tp->snd_wnd))
13119 			KMOD_TCPSTAT_INC(tcps_rcvwinupd);
13120 		tp->snd_wnd = tiwin;
13121 		rack_validate_fo_sendwin_up(tp, rack);
13122 		tp->snd_wl1 = seq;
13123 		tp->snd_wl2 = ack;
13124 		if (tp->snd_wnd > tp->max_sndwnd)
13125 			tp->max_sndwnd = tp->snd_wnd;
13126 	    rack->r_wanted_output = 1;
13127 	} else if ((tp->snd_wl2 == ack) && (tiwin < tp->snd_wnd)) {
13128 		tp->snd_wnd = tiwin;
13129 		rack_validate_fo_sendwin_up(tp, rack);
13130 		tp->snd_wl1 = seq;
13131 		tp->snd_wl2 = ack;
13132 	} else {
13133 		/* Not a valid win update */
13134 		return;
13135 	}
13136 	/* Do we exit persists? */
13137 	if ((rack->rc_in_persist != 0) &&
13138 	    (tp->snd_wnd >= min((rack->r_ctl.rc_high_rwnd/2),
13139 				rack->r_ctl.rc_pace_min_segs))) {
13140 		rack_exit_persist(tp, rack, cts);
13141 	}
13142 	/* Do we enter persists? */
13143 	if ((rack->rc_in_persist == 0) &&
13144 	    (tp->snd_wnd < min((rack->r_ctl.rc_high_rwnd/2), rack->r_ctl.rc_pace_min_segs)) &&
13145 	    TCPS_HAVEESTABLISHED(tp->t_state) &&
13146 	    ((tp->snd_max == tp->snd_una) || rack->rc_has_collapsed) &&
13147 	    sbavail(&tptosocket(tp)->so_snd) &&
13148 	    (sbavail(&tptosocket(tp)->so_snd) > tp->snd_wnd)) {
13149 		/*
13150 		 * Here the rwnd is less than
13151 		 * the pacing size, we are established,
13152 		 * nothing is outstanding, and there is
13153 		 * data to send. Enter persists.
13154 		 */
13155 		rack_enter_persist(tp, rack, rack->r_ctl.rc_rcvtime);
13156 	}
13157 }
13158 
13159 static void
13160 rack_log_input_packet(struct tcpcb *tp, struct tcp_rack *rack, struct tcp_ackent *ae, int ackval, uint32_t high_seq)
13161 {
13162 
13163 	if (tp->t_logstate != TCP_LOG_STATE_OFF) {
13164 		struct inpcb *inp = tptoinpcb(tp);
13165 		union tcp_log_stackspecific log;
13166 		struct timeval ltv;
13167 		char tcp_hdr_buf[60];
13168 		struct tcphdr *th;
13169 		struct timespec ts;
13170 		uint32_t orig_snd_una;
13171 		uint8_t xx = 0;
13172 
13173 #ifdef NETFLIX_HTTP_LOGGING
13174 		struct http_sendfile_track *http_req;
13175 
13176 		if (SEQ_GT(ae->ack, tp->snd_una)) {
13177 			http_req = tcp_http_find_req_for_seq(tp, (ae->ack-1));
13178 		} else {
13179 			http_req = tcp_http_find_req_for_seq(tp, ae->ack);
13180 		}
13181 #endif
13182 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
13183 		log.u_bbr.inhpts = tcp_in_hpts(rack->rc_inp);
13184 		if (rack->rack_no_prr == 0)
13185 			log.u_bbr.flex1 = rack->r_ctl.rc_prr_sndcnt;
13186 		else
13187 			log.u_bbr.flex1 = 0;
13188 		log.u_bbr.use_lt_bw = rack->r_ent_rec_ns;
13189 		log.u_bbr.use_lt_bw <<= 1;
13190 		log.u_bbr.use_lt_bw |= rack->r_might_revert;
13191 		log.u_bbr.flex2 = rack->r_ctl.rc_num_maps_alloced;
13192 		log.u_bbr.inflight = ctf_flight_size(tp, rack->r_ctl.rc_sacked);
13193 		log.u_bbr.pkts_out = tp->t_maxseg;
13194 		log.u_bbr.flex4 = rack->r_ctl.rc_hpts_flags;
13195 		log.u_bbr.flex7 = 1;
13196 		log.u_bbr.lost = ae->flags;
13197 		log.u_bbr.cwnd_gain = ackval;
13198 		log.u_bbr.pacing_gain = 0x2;
13199 		if (ae->flags & TSTMP_HDWR) {
13200 			/* Record the hardware timestamp if present */
13201 			log.u_bbr.flex3 = M_TSTMP;
13202 			ts.tv_sec = ae->timestamp / 1000000000;
13203 			ts.tv_nsec = ae->timestamp % 1000000000;
13204 			ltv.tv_sec = ts.tv_sec;
13205 			ltv.tv_usec = ts.tv_nsec / 1000;
13206 			log.u_bbr.lt_epoch = tcp_tv_to_usectick(&ltv);
13207 		} else if (ae->flags & TSTMP_LRO) {
13208 			/* Record the LRO the arrival timestamp */
13209 			log.u_bbr.flex3 = M_TSTMP_LRO;
13210 			ts.tv_sec = ae->timestamp / 1000000000;
13211 			ts.tv_nsec = ae->timestamp % 1000000000;
13212 			ltv.tv_sec = ts.tv_sec;
13213 			ltv.tv_usec = ts.tv_nsec / 1000;
13214 			log.u_bbr.flex5 = tcp_tv_to_usectick(&ltv);
13215 		}
13216 		log.u_bbr.timeStamp = tcp_get_usecs(&ltv);
13217 		/* Log the rcv time */
13218 		log.u_bbr.delRate = ae->timestamp;
13219 #ifdef NETFLIX_HTTP_LOGGING
13220 		log.u_bbr.applimited = tp->t_http_closed;
13221 		log.u_bbr.applimited <<= 8;
13222 		log.u_bbr.applimited |= tp->t_http_open;
13223 		log.u_bbr.applimited <<= 8;
13224 		log.u_bbr.applimited |= tp->t_http_req;
13225 		if (http_req) {
13226 			/* Copy out any client req info */
13227 			/* seconds */
13228 			log.u_bbr.pkt_epoch = (http_req->localtime / HPTS_USEC_IN_SEC);
13229 			/* useconds */
13230 			log.u_bbr.delivered = (http_req->localtime % HPTS_USEC_IN_SEC);
13231 			log.u_bbr.rttProp = http_req->timestamp;
13232 			log.u_bbr.cur_del_rate = http_req->start;
13233 			if (http_req->flags & TCP_HTTP_TRACK_FLG_OPEN) {
13234 				log.u_bbr.flex8 |= 1;
13235 			} else {
13236 				log.u_bbr.flex8 |= 2;
13237 				log.u_bbr.bw_inuse = http_req->end;
13238 			}
13239 			log.u_bbr.flex6 = http_req->start_seq;
13240 			if (http_req->flags & TCP_HTTP_TRACK_FLG_COMP) {
13241 				log.u_bbr.flex8 |= 4;
13242 				log.u_bbr.epoch = http_req->end_seq;
13243 			}
13244 		}
13245 #endif
13246 		memset(tcp_hdr_buf, 0, sizeof(tcp_hdr_buf));
13247 		th = (struct tcphdr *)tcp_hdr_buf;
13248 		th->th_seq = ae->seq;
13249 		th->th_ack = ae->ack;
13250 		th->th_win = ae->win;
13251 		/* Now fill in the ports */
13252 		th->th_sport = inp->inp_fport;
13253 		th->th_dport = inp->inp_lport;
13254 		tcp_set_flags(th, ae->flags);
13255 		/* Now do we have a timestamp option? */
13256 		if (ae->flags & HAS_TSTMP) {
13257 			u_char *cp;
13258 			uint32_t val;
13259 
13260 			th->th_off = ((sizeof(struct tcphdr) + TCPOLEN_TSTAMP_APPA) >> 2);
13261 			cp = (u_char *)(th + 1);
13262 			*cp = TCPOPT_NOP;
13263 			cp++;
13264 			*cp = TCPOPT_NOP;
13265 			cp++;
13266 			*cp = TCPOPT_TIMESTAMP;
13267 			cp++;
13268 			*cp = TCPOLEN_TIMESTAMP;
13269 			cp++;
13270 			val = htonl(ae->ts_value);
13271 			bcopy((char *)&val,
13272 			      (char *)cp, sizeof(uint32_t));
13273 			val = htonl(ae->ts_echo);
13274 			bcopy((char *)&val,
13275 			      (char *)(cp + 4), sizeof(uint32_t));
13276 		} else
13277 			th->th_off = (sizeof(struct tcphdr) >> 2);
13278 
13279 		/*
13280 		 * For sane logging we need to play a little trick.
13281 		 * If the ack were fully processed we would have moved
13282 		 * snd_una to high_seq, but since compressed acks are
13283 		 * processed in two phases, at this point (logging) snd_una
13284 		 * won't be advanced. So we would see multiple acks showing
13285 		 * the advancement. We can prevent that by "pretending" that
13286 		 * snd_una was advanced and then un-advancing it so that the
13287 		 * logging code has the right value for tlb_snd_una.
13288 		 */
13289 		if (tp->snd_una != high_seq) {
13290 			orig_snd_una = tp->snd_una;
13291 			tp->snd_una = high_seq;
13292 			xx = 1;
13293 		} else
13294 			xx = 0;
13295 		TCP_LOG_EVENTP(tp, th,
13296 			       &tptosocket(tp)->so_rcv,
13297 			       &tptosocket(tp)->so_snd, TCP_LOG_IN, 0,
13298 			       0, &log, true, &ltv);
13299 		if (xx) {
13300 			tp->snd_una = orig_snd_una;
13301 		}
13302 	}
13303 
13304 }
13305 
13306 static void
13307 rack_handle_probe_response(struct tcp_rack *rack, uint32_t tiwin, uint32_t us_cts)
13308 {
13309 	uint32_t us_rtt;
13310 	/*
13311 	 * A persist or keep-alive was forced out, update our
13312 	 * min rtt time. Note now worry about lost responses.
13313 	 * When a subsequent keep-alive or persist times out
13314 	 * and forced_ack is still on, then the last probe
13315 	 * was not responded to. In such cases we have a
13316 	 * sysctl that controls the behavior. Either we apply
13317 	 * the rtt but with reduced confidence (0). Or we just
13318 	 * plain don't apply the rtt estimate. Having data flow
13319 	 * will clear the probe_not_answered flag i.e. cum-ack
13320 	 * move forward <or> exiting and reentering persists.
13321 	 */
13322 
13323 	rack->forced_ack = 0;
13324 	rack->rc_tp->t_rxtshift = 0;
13325 	if ((rack->rc_in_persist &&
13326 	     (tiwin == rack->rc_tp->snd_wnd)) ||
13327 	    (rack->rc_in_persist == 0)) {
13328 		/*
13329 		 * In persists only apply the RTT update if this is
13330 		 * a response to our window probe. And that
13331 		 * means the rwnd sent must match the current
13332 		 * snd_wnd. If it does not, then we got a
13333 		 * window update ack instead. For keepalive
13334 		 * we allow the answer no matter what the window.
13335 		 *
13336 		 * Note that if the probe_not_answered is set then
13337 		 * the forced_ack_ts is the oldest one i.e. the first
13338 		 * probe sent that might have been lost. This assures
13339 		 * us that if we do calculate an RTT it is longer not
13340 		 * some short thing.
13341 		 */
13342 		if (rack->rc_in_persist)
13343 			counter_u64_add(rack_persists_acks, 1);
13344 		us_rtt = us_cts - rack->r_ctl.forced_ack_ts;
13345 		if (us_rtt == 0)
13346 			us_rtt = 1;
13347 		if (rack->probe_not_answered == 0) {
13348 			rack_apply_updated_usrtt(rack, us_rtt, us_cts);
13349 			tcp_rack_xmit_timer(rack, us_rtt, 0, us_rtt, 3, NULL, 1);
13350 		} else {
13351 			/* We have a retransmitted probe here too */
13352 			if (rack_apply_rtt_with_reduced_conf) {
13353 				rack_apply_updated_usrtt(rack, us_rtt, us_cts);
13354 				tcp_rack_xmit_timer(rack, us_rtt, 0, us_rtt, 0, NULL, 1);
13355 			}
13356 		}
13357 	}
13358 }
13359 
13360 static int
13361 rack_do_compressed_ack_processing(struct tcpcb *tp, struct socket *so, struct mbuf *m, int nxt_pkt, struct timeval *tv)
13362 {
13363 	/*
13364 	 * Handle a "special" compressed ack mbuf. Each incoming
13365 	 * ack has only four possible dispositions:
13366 	 *
13367 	 * A) It moves the cum-ack forward
13368 	 * B) It is behind the cum-ack.
13369 	 * C) It is a window-update ack.
13370 	 * D) It is a dup-ack.
13371 	 *
13372 	 * Note that we can have between 1 -> TCP_COMP_ACK_ENTRIES
13373 	 * in the incoming mbuf. We also need to still pay attention
13374 	 * to nxt_pkt since there may be another packet after this
13375 	 * one.
13376 	 */
13377 #ifdef TCP_ACCOUNTING
13378 	uint64_t ts_val;
13379 	uint64_t rdstc;
13380 #endif
13381 	int segsiz;
13382 	struct timespec ts;
13383 	struct tcp_rack *rack;
13384 	struct tcp_ackent *ae;
13385 	uint32_t tiwin, ms_cts, cts, acked, acked_amount, high_seq, win_seq, the_win, win_upd_ack;
13386 	int cnt, i, did_out, ourfinisacked = 0;
13387 	struct tcpopt to_holder, *to = NULL;
13388 #ifdef TCP_ACCOUNTING
13389 	int win_up_req = 0;
13390 #endif
13391 	int nsegs = 0;
13392 	int under_pacing = 1;
13393 	int recovery = 0;
13394 #ifdef TCP_ACCOUNTING
13395 	sched_pin();
13396 #endif
13397 	rack = (struct tcp_rack *)tp->t_fb_ptr;
13398 	if (rack->gp_ready &&
13399 	    (rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT))
13400 		under_pacing = 0;
13401 	else
13402 		under_pacing = 1;
13403 
13404 	if (rack->r_state != tp->t_state)
13405 		rack_set_state(tp, rack);
13406 	if ((tp->t_state >= TCPS_FIN_WAIT_1) &&
13407 	    (tp->t_flags & TF_GPUTINPROG)) {
13408 		/*
13409 		 * We have a goodput in progress
13410 		 * and we have entered a late state.
13411 		 * Do we have enough data in the sb
13412 		 * to handle the GPUT request?
13413 		 */
13414 		uint32_t bytes;
13415 
13416 		bytes = tp->gput_ack - tp->gput_seq;
13417 		if (SEQ_GT(tp->gput_seq, tp->snd_una))
13418 			bytes += tp->gput_seq - tp->snd_una;
13419 		if (bytes > sbavail(&tptosocket(tp)->so_snd)) {
13420 			/*
13421 			 * There are not enough bytes in the socket
13422 			 * buffer that have been sent to cover this
13423 			 * measurement. Cancel it.
13424 			 */
13425 			rack_log_pacing_delay_calc(rack, (tp->gput_ack - tp->gput_seq) /*flex2*/,
13426 						   rack->r_ctl.rc_gp_srtt /*flex1*/,
13427 						   tp->gput_seq,
13428 						   0, 0, 18, __LINE__, NULL, 0);
13429 			tp->t_flags &= ~TF_GPUTINPROG;
13430 		}
13431 	}
13432 	to = &to_holder;
13433 	to->to_flags = 0;
13434 	KASSERT((m->m_len >= sizeof(struct tcp_ackent)),
13435 		("tp:%p m_cmpack:%p with invalid len:%u", tp, m, m->m_len));
13436 	cnt = m->m_len / sizeof(struct tcp_ackent);
13437 	counter_u64_add(rack_multi_single_eq, cnt);
13438 	high_seq = tp->snd_una;
13439 	the_win = tp->snd_wnd;
13440 	win_seq = tp->snd_wl1;
13441 	win_upd_ack = tp->snd_wl2;
13442 	cts = tcp_tv_to_usectick(tv);
13443 	ms_cts = tcp_tv_to_mssectick(tv);
13444 	rack->r_ctl.rc_rcvtime = cts;
13445 	segsiz = ctf_fixed_maxseg(tp);
13446 	if ((rack->rc_gp_dyn_mul) &&
13447 	    (rack->use_fixed_rate == 0) &&
13448 	    (rack->rc_always_pace)) {
13449 		/* Check in on probertt */
13450 		rack_check_probe_rtt(rack, cts);
13451 	}
13452 	for (i = 0; i < cnt; i++) {
13453 #ifdef TCP_ACCOUNTING
13454 		ts_val = get_cyclecount();
13455 #endif
13456 		rack_clear_rate_sample(rack);
13457 		ae = ((mtod(m, struct tcp_ackent *)) + i);
13458 		/* Setup the window */
13459 		tiwin = ae->win << tp->snd_scale;
13460 		if (tiwin > rack->r_ctl.rc_high_rwnd)
13461 			rack->r_ctl.rc_high_rwnd = tiwin;
13462 		/* figure out the type of ack */
13463 		if (SEQ_LT(ae->ack, high_seq)) {
13464 			/* Case B*/
13465 			ae->ack_val_set = ACK_BEHIND;
13466 		} else if (SEQ_GT(ae->ack, high_seq)) {
13467 			/* Case A */
13468 			ae->ack_val_set = ACK_CUMACK;
13469 		} else if ((tiwin == the_win) && (rack->rc_in_persist == 0)){
13470 			/* Case D */
13471 			ae->ack_val_set = ACK_DUPACK;
13472 		} else {
13473 			/* Case C */
13474 			ae->ack_val_set = ACK_RWND;
13475 		}
13476 		rack_log_input_packet(tp, rack, ae, ae->ack_val_set, high_seq);
13477 		/* Validate timestamp */
13478 		if (ae->flags & HAS_TSTMP) {
13479 			/* Setup for a timestamp */
13480 			to->to_flags = TOF_TS;
13481 			ae->ts_echo -= tp->ts_offset;
13482 			to->to_tsecr = ae->ts_echo;
13483 			to->to_tsval = ae->ts_value;
13484 			/*
13485 			 * If echoed timestamp is later than the current time, fall back to
13486 			 * non RFC1323 RTT calculation.  Normalize timestamp if syncookies
13487 			 * were used when this connection was established.
13488 			 */
13489 			if (TSTMP_GT(ae->ts_echo, ms_cts))
13490 				to->to_tsecr = 0;
13491 			if (tp->ts_recent &&
13492 			    TSTMP_LT(ae->ts_value, tp->ts_recent)) {
13493 				if (ctf_ts_check_ac(tp, (ae->flags & 0xff))) {
13494 #ifdef TCP_ACCOUNTING
13495 					rdstc = get_cyclecount();
13496 					if (rdstc > ts_val) {
13497 						counter_u64_add(tcp_proc_time[ae->ack_val_set] ,
13498 								(rdstc - ts_val));
13499 						if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
13500 							tp->tcp_proc_time[ae->ack_val_set] += (rdstc - ts_val);
13501 						}
13502 					}
13503 #endif
13504 					continue;
13505 				}
13506 			}
13507 			if (SEQ_LEQ(ae->seq, tp->last_ack_sent) &&
13508 			    SEQ_LEQ(tp->last_ack_sent, ae->seq)) {
13509 				tp->ts_recent_age = tcp_ts_getticks();
13510 				tp->ts_recent = ae->ts_value;
13511 			}
13512 		} else {
13513 			/* Setup for a no options */
13514 			to->to_flags = 0;
13515 		}
13516 		/* Update the rcv time and perform idle reduction possibly */
13517 		if  (tp->t_idle_reduce &&
13518 		     (tp->snd_max == tp->snd_una) &&
13519 		     (TICKS_2_USEC(ticks - tp->t_rcvtime) >= tp->t_rxtcur)) {
13520 			counter_u64_add(rack_input_idle_reduces, 1);
13521 			rack_cc_after_idle(rack, tp);
13522 		}
13523 		tp->t_rcvtime = ticks;
13524 		/* Now what about ECN of a chain of pure ACKs? */
13525 		if (tcp_ecn_input_segment(tp, ae->flags, 0,
13526 			tcp_packets_this_ack(tp, ae->ack),
13527 			ae->codepoint))
13528 			rack_cong_signal(tp, CC_ECN, ae->ack, __LINE__);
13529 #ifdef TCP_ACCOUNTING
13530 		/* Count for the specific type of ack in */
13531 		counter_u64_add(tcp_cnt_counters[ae->ack_val_set], 1);
13532 		if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
13533 			tp->tcp_cnt_counters[ae->ack_val_set]++;
13534 		}
13535 #endif
13536 		/*
13537 		 * Note how we could move up these in the determination
13538 		 * above, but we don't so that way the timestamp checks (and ECN)
13539 		 * is done first before we do any processing on the ACK.
13540 		 * The non-compressed path through the code has this
13541 		 * weakness (noted by @jtl) that it actually does some
13542 		 * processing before verifying the timestamp information.
13543 		 * We don't take that path here which is why we set
13544 		 * the ack_val_set first, do the timestamp and ecn
13545 		 * processing, and then look at what we have setup.
13546 		 */
13547 		if (ae->ack_val_set == ACK_BEHIND) {
13548 			/*
13549 			 * Case B flag reordering, if window is not closed
13550 			 * or it could be a keep-alive or persists
13551 			 */
13552 			if (SEQ_LT(ae->ack, tp->snd_una) && (sbspace(&so->so_rcv) > segsiz)) {
13553 				rack->r_ctl.rc_reorder_ts = tcp_tv_to_usectick(&rack->r_ctl.act_rcv_time);
13554 			}
13555 		} else if (ae->ack_val_set == ACK_DUPACK) {
13556 			/* Case D */
13557 			rack_strike_dupack(rack);
13558 		} else if (ae->ack_val_set == ACK_RWND) {
13559 			/* Case C */
13560 			if ((ae->flags & TSTMP_LRO) || (ae->flags & TSTMP_HDWR)) {
13561 				ts.tv_sec = ae->timestamp / 1000000000;
13562 				ts.tv_nsec = ae->timestamp % 1000000000;
13563 				rack->r_ctl.act_rcv_time.tv_sec = ts.tv_sec;
13564 				rack->r_ctl.act_rcv_time.tv_usec = ts.tv_nsec/1000;
13565 			} else {
13566 				rack->r_ctl.act_rcv_time = *tv;
13567 			}
13568 			if (rack->forced_ack) {
13569 				rack_handle_probe_response(rack, tiwin,
13570 							   tcp_tv_to_usectick(&rack->r_ctl.act_rcv_time));
13571 			}
13572 #ifdef TCP_ACCOUNTING
13573 			win_up_req = 1;
13574 #endif
13575 			win_upd_ack = ae->ack;
13576 			win_seq = ae->seq;
13577 			the_win = tiwin;
13578 			rack_do_win_updates(tp, rack, the_win, win_seq, win_upd_ack, cts, high_seq);
13579 		} else {
13580 			/* Case A */
13581 			if (SEQ_GT(ae->ack, tp->snd_max)) {
13582 				/*
13583 				 * We just send an ack since the incoming
13584 				 * ack is beyond the largest seq we sent.
13585 				 */
13586 				if ((tp->t_flags & TF_ACKNOW) == 0) {
13587 					ctf_ack_war_checks(tp, &rack->r_ctl.challenge_ack_ts, &rack->r_ctl.challenge_ack_cnt);
13588 					if (tp->t_flags && TF_ACKNOW)
13589 						rack->r_wanted_output = 1;
13590 				}
13591 			} else {
13592 				nsegs++;
13593 				/* If the window changed setup to update */
13594 				if (tiwin != tp->snd_wnd) {
13595 					win_upd_ack = ae->ack;
13596 					win_seq = ae->seq;
13597 					the_win = tiwin;
13598 					rack_do_win_updates(tp, rack, the_win, win_seq, win_upd_ack, cts, high_seq);
13599 				}
13600 #ifdef TCP_ACCOUNTING
13601 				/* Account for the acks */
13602 				if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
13603 					tp->tcp_cnt_counters[CNT_OF_ACKS_IN] += (((ae->ack - high_seq) + segsiz - 1) / segsiz);
13604 				}
13605 				counter_u64_add(tcp_cnt_counters[CNT_OF_ACKS_IN],
13606 						(((ae->ack - high_seq) + segsiz - 1) / segsiz));
13607 #endif
13608 				high_seq = ae->ack;
13609 				if (rack_verbose_logging && (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF)) {
13610 					union tcp_log_stackspecific log;
13611 					struct timeval tv;
13612 
13613 					memset(&log.u_bbr, 0, sizeof(log.u_bbr));
13614 					log.u_bbr.timeStamp = tcp_get_usecs(&tv);
13615 					log.u_bbr.flex1 = high_seq;
13616 					log.u_bbr.flex2 = rack->r_ctl.roundends;
13617 					log.u_bbr.flex3 = rack->r_ctl.current_round;
13618 					log.u_bbr.rttProp = (uint64_t)CC_ALGO(tp)->newround;
13619 					log.u_bbr.flex8 = 8;
13620 					tcp_log_event_(tp, NULL, NULL, NULL, BBR_LOG_CWND, 0,
13621 						       0, &log, false, NULL, NULL, 0, &tv);
13622 				}
13623 				/*
13624 				 * The draft (v3) calls for us to use SEQ_GEQ, but that
13625 				 * causes issues when we are just going app limited. Lets
13626 				 * instead use SEQ_GT <or> where its equal but more data
13627 				 * is outstanding.
13628 				 */
13629 				if ((SEQ_GT(high_seq, rack->r_ctl.roundends)) ||
13630 				    ((high_seq == rack->r_ctl.roundends) &&
13631 				     SEQ_GT(tp->snd_max, tp->snd_una))) {
13632 					rack->r_ctl.current_round++;
13633 					rack->r_ctl.roundends = tp->snd_max;
13634 					if (CC_ALGO(tp)->newround != NULL) {
13635 						CC_ALGO(tp)->newround(tp->ccv, rack->r_ctl.current_round);
13636 					}
13637 				}
13638 				/* Setup our act_rcv_time */
13639 				if ((ae->flags & TSTMP_LRO) || (ae->flags & TSTMP_HDWR)) {
13640 					ts.tv_sec = ae->timestamp / 1000000000;
13641 					ts.tv_nsec = ae->timestamp % 1000000000;
13642 					rack->r_ctl.act_rcv_time.tv_sec = ts.tv_sec;
13643 					rack->r_ctl.act_rcv_time.tv_usec = ts.tv_nsec/1000;
13644 				} else {
13645 					rack->r_ctl.act_rcv_time = *tv;
13646 				}
13647 				rack_process_to_cumack(tp, rack, ae->ack, cts, to);
13648 				if (rack->rc_dsack_round_seen) {
13649 					/* Is the dsack round over? */
13650 					if (SEQ_GEQ(ae->ack, rack->r_ctl.dsack_round_end)) {
13651 						/* Yes it is */
13652 						rack->rc_dsack_round_seen = 0;
13653 						rack_log_dsack_event(rack, 3, __LINE__, 0, 0);
13654 					}
13655 				}
13656 			}
13657 		}
13658 		/* And lets be sure to commit the rtt measurements for this ack */
13659 		tcp_rack_xmit_timer_commit(rack, tp);
13660 #ifdef TCP_ACCOUNTING
13661 		rdstc = get_cyclecount();
13662 		if (rdstc > ts_val) {
13663 			counter_u64_add(tcp_proc_time[ae->ack_val_set] , (rdstc - ts_val));
13664 			if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
13665 				tp->tcp_proc_time[ae->ack_val_set] += (rdstc - ts_val);
13666 				if (ae->ack_val_set == ACK_CUMACK)
13667 					tp->tcp_proc_time[CYC_HANDLE_MAP] += (rdstc - ts_val);
13668 			}
13669 		}
13670 #endif
13671 	}
13672 #ifdef TCP_ACCOUNTING
13673 	ts_val = get_cyclecount();
13674 #endif
13675 	/* Tend to any collapsed window */
13676 	if (SEQ_GT(tp->snd_max, high_seq) && (tp->snd_wnd < (tp->snd_max - high_seq))) {
13677 		/* The peer collapsed the window */
13678 		rack_collapsed_window(rack, (tp->snd_max - high_seq), __LINE__);
13679 	} else if (rack->rc_has_collapsed)
13680 		rack_un_collapse_window(rack, __LINE__);
13681 	if ((rack->r_collapse_point_valid) &&
13682 	    (SEQ_GT(high_seq, rack->r_ctl.high_collapse_point)))
13683 		rack->r_collapse_point_valid = 0;
13684 	acked_amount = acked = (high_seq - tp->snd_una);
13685 	if (acked) {
13686 		/*
13687 		 * Clear the probe not answered flag
13688 		 * since cum-ack moved forward.
13689 		 */
13690 		rack->probe_not_answered = 0;
13691 		if (rack->sack_attack_disable == 0)
13692 			rack_do_decay(rack);
13693 		if (acked >= segsiz) {
13694 			/*
13695 			 * You only get credit for
13696 			 * MSS and greater (and you get extra
13697 			 * credit for larger cum-ack moves).
13698 			 */
13699 			int ac;
13700 
13701 			ac = acked / segsiz;
13702 			rack->r_ctl.ack_count += ac;
13703 			counter_u64_add(rack_ack_total, ac);
13704 		}
13705 		if (rack->r_ctl.ack_count > 0xfff00000) {
13706 			/*
13707 			 * reduce the number to keep us under
13708 			 * a uint32_t.
13709 			 */
13710 			rack->r_ctl.ack_count /= 2;
13711 			rack->r_ctl.sack_count /= 2;
13712 		}
13713 		if (tp->t_flags & TF_NEEDSYN) {
13714 			/*
13715 			 * T/TCP: Connection was half-synchronized, and our SYN has
13716 			 * been ACK'd (so connection is now fully synchronized).  Go
13717 			 * to non-starred state, increment snd_una for ACK of SYN,
13718 			 * and check if we can do window scaling.
13719 			 */
13720 			tp->t_flags &= ~TF_NEEDSYN;
13721 			tp->snd_una++;
13722 			acked_amount = acked = (high_seq - tp->snd_una);
13723 		}
13724 		if (acked > sbavail(&so->so_snd))
13725 			acked_amount = sbavail(&so->so_snd);
13726 #ifdef NETFLIX_EXP_DETECTION
13727 		/*
13728 		 * We only care on a cum-ack move if we are in a sack-disabled
13729 		 * state. We have already added in to the ack_count, and we never
13730 		 * would disable on a cum-ack move, so we only care to do the
13731 		 * detection if it may "undo" it, i.e. we were in disabled already.
13732 		 */
13733 		if (rack->sack_attack_disable)
13734 			rack_do_detection(tp, rack, acked_amount, segsiz);
13735 #endif
13736 		if (IN_FASTRECOVERY(tp->t_flags) &&
13737 		    (rack->rack_no_prr == 0))
13738 			rack_update_prr(tp, rack, acked_amount, high_seq);
13739 		if (IN_RECOVERY(tp->t_flags)) {
13740 			if (SEQ_LT(high_seq, tp->snd_recover) &&
13741 			    (SEQ_LT(high_seq, tp->snd_max))) {
13742 				tcp_rack_partialack(tp);
13743 			} else {
13744 				rack_post_recovery(tp, high_seq);
13745 				recovery = 1;
13746 			}
13747 		}
13748 		/* Handle the rack-log-ack part (sendmap) */
13749 		if ((sbused(&so->so_snd) == 0) &&
13750 		    (acked > acked_amount) &&
13751 		    (tp->t_state >= TCPS_FIN_WAIT_1) &&
13752 		    (tp->t_flags & TF_SENTFIN)) {
13753 			/*
13754 			 * We must be sure our fin
13755 			 * was sent and acked (we can be
13756 			 * in FIN_WAIT_1 without having
13757 			 * sent the fin).
13758 			 */
13759 			ourfinisacked = 1;
13760 			/*
13761 			 * Lets make sure snd_una is updated
13762 			 * since most likely acked_amount = 0 (it
13763 			 * should be).
13764 			 */
13765 			tp->snd_una = high_seq;
13766 		}
13767 		/* Did we make a RTO error? */
13768 		if ((tp->t_flags & TF_PREVVALID) &&
13769 		    ((tp->t_flags & TF_RCVD_TSTMP) == 0)) {
13770 			tp->t_flags &= ~TF_PREVVALID;
13771 			if (tp->t_rxtshift == 1 &&
13772 			    (int)(ticks - tp->t_badrxtwin) < 0)
13773 				rack_cong_signal(tp, CC_RTO_ERR, high_seq, __LINE__);
13774 		}
13775 		/* Handle the data in the socket buffer */
13776 		KMOD_TCPSTAT_ADD(tcps_rcvackpack, 1);
13777 		KMOD_TCPSTAT_ADD(tcps_rcvackbyte, acked);
13778 		if (acked_amount > 0) {
13779 			struct mbuf *mfree;
13780 
13781 			rack_ack_received(tp, rack, high_seq, nsegs, CC_ACK, recovery);
13782 			SOCKBUF_LOCK(&so->so_snd);
13783 			mfree = sbcut_locked(&so->so_snd, acked_amount);
13784 			tp->snd_una = high_seq;
13785 			/* Note we want to hold the sb lock through the sendmap adjust */
13786 			rack_adjust_sendmap(rack, &so->so_snd, tp->snd_una);
13787 			/* Wake up the socket if we have room to write more */
13788 			rack_log_wakeup(tp,rack, &so->so_snd, acked, 2);
13789 			sowwakeup_locked(so);
13790 			m_freem(mfree);
13791 		}
13792 		/* update progress */
13793 		tp->t_acktime = ticks;
13794 		rack_log_progress_event(rack, tp, tp->t_acktime,
13795 					PROGRESS_UPDATE, __LINE__);
13796 		/* Clear out shifts and such */
13797 		tp->t_rxtshift = 0;
13798 		RACK_TCPT_RANGESET(tp->t_rxtcur, RACK_REXMTVAL(tp),
13799 				   rack_rto_min, rack_rto_max, rack->r_ctl.timer_slop);
13800 		rack->rc_tlp_in_progress = 0;
13801 		rack->r_ctl.rc_tlp_cnt_out = 0;
13802 		/* Send recover and snd_nxt must be dragged along */
13803 		if (SEQ_GT(tp->snd_una, tp->snd_recover))
13804 			tp->snd_recover = tp->snd_una;
13805 		if (SEQ_LT(tp->snd_nxt, tp->snd_una))
13806 			tp->snd_nxt = tp->snd_una;
13807 		/*
13808 		 * If the RXT timer is running we want to
13809 		 * stop it, so we can restart a TLP (or new RXT).
13810 		 */
13811 		if (rack->r_ctl.rc_hpts_flags & PACE_TMR_RXT)
13812 			rack_timer_cancel(tp, rack, rack->r_ctl.rc_rcvtime, __LINE__);
13813 #ifdef NETFLIX_HTTP_LOGGING
13814 		tcp_http_check_for_comp(rack->rc_tp, high_seq);
13815 #endif
13816 		tp->snd_wl2 = high_seq;
13817 		tp->t_dupacks = 0;
13818 		if (under_pacing &&
13819 		    (rack->use_fixed_rate == 0) &&
13820 		    (rack->in_probe_rtt == 0) &&
13821 		    rack->rc_gp_dyn_mul &&
13822 		    rack->rc_always_pace) {
13823 			/* Check if we are dragging bottom */
13824 			rack_check_bottom_drag(tp, rack, so, acked);
13825 		}
13826 		if (tp->snd_una == tp->snd_max) {
13827 			tp->t_flags &= ~TF_PREVVALID;
13828 			rack->r_ctl.retran_during_recovery = 0;
13829 			rack->r_ctl.dsack_byte_cnt = 0;
13830 			rack->r_ctl.rc_went_idle_time = tcp_get_usecs(NULL);
13831 			if (rack->r_ctl.rc_went_idle_time == 0)
13832 				rack->r_ctl.rc_went_idle_time = 1;
13833 			rack_log_progress_event(rack, tp, 0, PROGRESS_CLEAR, __LINE__);
13834 			if (sbavail(&tptosocket(tp)->so_snd) == 0)
13835 				tp->t_acktime = 0;
13836 			/* Set so we might enter persists... */
13837 			rack->r_wanted_output = 1;
13838 			rack_timer_cancel(tp, rack, rack->r_ctl.rc_rcvtime, __LINE__);
13839 			sack_filter_clear(&rack->r_ctl.rack_sf, tp->snd_una);
13840 			if ((tp->t_state >= TCPS_FIN_WAIT_1) &&
13841 			    (sbavail(&so->so_snd) == 0) &&
13842 			    (tp->t_flags2 & TF2_DROP_AF_DATA)) {
13843 				/*
13844 				 * The socket was gone and the
13845 				 * peer sent data (not now in the past), time to
13846 				 * reset him.
13847 				 */
13848 				rack_timer_cancel(tp, rack, rack->r_ctl.rc_rcvtime, __LINE__);
13849 				/* tcp_close will kill the inp pre-log the Reset */
13850 				tcp_log_end_status(tp, TCP_EI_STATUS_SERVER_RST);
13851 #ifdef TCP_ACCOUNTING
13852 				rdstc = get_cyclecount();
13853 				if (rdstc > ts_val) {
13854 					counter_u64_add(tcp_proc_time[ACK_CUMACK] , (rdstc - ts_val));
13855 					if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
13856 						tp->tcp_proc_time[ACK_CUMACK] += (rdstc - ts_val);
13857 						tp->tcp_proc_time[CYC_HANDLE_ACK] += (rdstc - ts_val);
13858 					}
13859 				}
13860 #endif
13861 				m_freem(m);
13862 				tp = tcp_close(tp);
13863 				if (tp == NULL) {
13864 #ifdef TCP_ACCOUNTING
13865 					sched_unpin();
13866 #endif
13867 					return (1);
13868 				}
13869 				/*
13870 				 * We would normally do drop-with-reset which would
13871 				 * send back a reset. We can't since we don't have
13872 				 * all the needed bits. Instead lets arrange for
13873 				 * a call to tcp_output(). That way since we
13874 				 * are in the closed state we will generate a reset.
13875 				 *
13876 				 * Note if tcp_accounting is on we don't unpin since
13877 				 * we do that after the goto label.
13878 				 */
13879 				goto send_out_a_rst;
13880 			}
13881 			if ((sbused(&so->so_snd) == 0) &&
13882 			    (tp->t_state >= TCPS_FIN_WAIT_1) &&
13883 			    (tp->t_flags & TF_SENTFIN)) {
13884 				/*
13885 				 * If we can't receive any more data, then closing user can
13886 				 * proceed. Starting the timer is contrary to the
13887 				 * specification, but if we don't get a FIN we'll hang
13888 				 * forever.
13889 				 *
13890 				 */
13891 				if (so->so_rcv.sb_state & SBS_CANTRCVMORE) {
13892 					soisdisconnected(so);
13893 					tcp_timer_activate(tp, TT_2MSL,
13894 							   (tcp_fast_finwait2_recycle ?
13895 							    tcp_finwait2_timeout :
13896 							    TP_MAXIDLE(tp)));
13897 				}
13898 				if (ourfinisacked == 0) {
13899 					/*
13900 					 * We don't change to fin-wait-2 if we have our fin acked
13901 					 * which means we are probably in TCPS_CLOSING.
13902 					 */
13903 					tcp_state_change(tp, TCPS_FIN_WAIT_2);
13904 				}
13905 			}
13906 		}
13907 		/* Wake up the socket if we have room to write more */
13908 		if (sbavail(&so->so_snd)) {
13909 			rack->r_wanted_output = 1;
13910 			if (ctf_progress_timeout_check(tp, true)) {
13911 				rack_log_progress_event((struct tcp_rack *)tp->t_fb_ptr,
13912 							tp, tick, PROGRESS_DROP, __LINE__);
13913 				/*
13914 				 * We cheat here and don't send a RST, we should send one
13915 				 * when the pacer drops the connection.
13916 				 */
13917 #ifdef TCP_ACCOUNTING
13918 				rdstc = get_cyclecount();
13919 				if (rdstc > ts_val) {
13920 					counter_u64_add(tcp_proc_time[ACK_CUMACK] , (rdstc - ts_val));
13921 					if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
13922 						tp->tcp_proc_time[ACK_CUMACK] += (rdstc - ts_val);
13923 						tp->tcp_proc_time[CYC_HANDLE_ACK] += (rdstc - ts_val);
13924 					}
13925 				}
13926 				sched_unpin();
13927 #endif
13928 				(void)tcp_drop(tp, ETIMEDOUT);
13929 				m_freem(m);
13930 				return (1);
13931 			}
13932 		}
13933 		if (ourfinisacked) {
13934 			switch(tp->t_state) {
13935 			case TCPS_CLOSING:
13936 #ifdef TCP_ACCOUNTING
13937 				rdstc = get_cyclecount();
13938 				if (rdstc > ts_val) {
13939 					counter_u64_add(tcp_proc_time[ACK_CUMACK] ,
13940 							(rdstc - ts_val));
13941 					if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
13942 						tp->tcp_proc_time[ACK_CUMACK] += (rdstc - ts_val);
13943 						tp->tcp_proc_time[CYC_HANDLE_ACK] += (rdstc - ts_val);
13944 					}
13945 				}
13946 				sched_unpin();
13947 #endif
13948 				tcp_twstart(tp);
13949 				m_freem(m);
13950 				return (1);
13951 				break;
13952 			case TCPS_LAST_ACK:
13953 #ifdef TCP_ACCOUNTING
13954 				rdstc = get_cyclecount();
13955 				if (rdstc > ts_val) {
13956 					counter_u64_add(tcp_proc_time[ACK_CUMACK] ,
13957 							(rdstc - ts_val));
13958 					if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
13959 						tp->tcp_proc_time[ACK_CUMACK] += (rdstc - ts_val);
13960 						tp->tcp_proc_time[CYC_HANDLE_ACK] += (rdstc - ts_val);
13961 					}
13962 				}
13963 				sched_unpin();
13964 #endif
13965 				tp = tcp_close(tp);
13966 				ctf_do_drop(m, tp);
13967 				return (1);
13968 				break;
13969 			case TCPS_FIN_WAIT_1:
13970 #ifdef TCP_ACCOUNTING
13971 				rdstc = get_cyclecount();
13972 				if (rdstc > ts_val) {
13973 					counter_u64_add(tcp_proc_time[ACK_CUMACK] ,
13974 							(rdstc - ts_val));
13975 					if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
13976 						tp->tcp_proc_time[ACK_CUMACK] += (rdstc - ts_val);
13977 						tp->tcp_proc_time[CYC_HANDLE_ACK] += (rdstc - ts_val);
13978 					}
13979 				}
13980 #endif
13981 				if (so->so_rcv.sb_state & SBS_CANTRCVMORE) {
13982 					soisdisconnected(so);
13983 					tcp_timer_activate(tp, TT_2MSL,
13984 							   (tcp_fast_finwait2_recycle ?
13985 							    tcp_finwait2_timeout :
13986 							    TP_MAXIDLE(tp)));
13987 				}
13988 				tcp_state_change(tp, TCPS_FIN_WAIT_2);
13989 				break;
13990 			default:
13991 				break;
13992 			}
13993 		}
13994 		if (rack->r_fast_output) {
13995 			/*
13996 			 * We re doing fast output.. can we expand that?
13997 			 */
13998 			rack_gain_for_fastoutput(rack, tp, so, acked_amount);
13999 		}
14000 #ifdef TCP_ACCOUNTING
14001 		rdstc = get_cyclecount();
14002 		if (rdstc > ts_val) {
14003 			counter_u64_add(tcp_proc_time[ACK_CUMACK] , (rdstc - ts_val));
14004 			if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
14005 				tp->tcp_proc_time[ACK_CUMACK] += (rdstc - ts_val);
14006 				tp->tcp_proc_time[CYC_HANDLE_ACK] += (rdstc - ts_val);
14007 			}
14008 		}
14009 
14010 	} else if (win_up_req) {
14011 		rdstc = get_cyclecount();
14012 		if (rdstc > ts_val) {
14013 			counter_u64_add(tcp_proc_time[ACK_RWND] , (rdstc - ts_val));
14014 			if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
14015 				tp->tcp_proc_time[ACK_RWND] += (rdstc - ts_val);
14016 			}
14017 		}
14018 #endif
14019 	}
14020 	/* Now is there a next packet, if so we are done */
14021 	m_freem(m);
14022 	did_out = 0;
14023 	if (nxt_pkt) {
14024 #ifdef TCP_ACCOUNTING
14025 		sched_unpin();
14026 #endif
14027 		rack_log_doseg_done(rack, cts, nxt_pkt, did_out, 5, nsegs);
14028 		return (0);
14029 	}
14030 	rack_handle_might_revert(tp, rack);
14031 	ctf_calc_rwin(so, tp);
14032 	if ((rack->r_wanted_output != 0) || (rack->r_fast_output != 0)) {
14033 	send_out_a_rst:
14034 		if (tcp_output(tp) < 0) {
14035 #ifdef TCP_ACCOUNTING
14036 			sched_unpin();
14037 #endif
14038 			return (1);
14039 		}
14040 		did_out = 1;
14041 	}
14042 	rack_free_trim(rack);
14043 #ifdef TCP_ACCOUNTING
14044 	sched_unpin();
14045 #endif
14046 	rack_timer_audit(tp, rack, &so->so_snd);
14047 	rack_log_doseg_done(rack, cts, nxt_pkt, did_out, 6, nsegs);
14048 	return (0);
14049 }
14050 
14051 
14052 static int
14053 rack_do_segment_nounlock(struct mbuf *m, struct tcphdr *th, struct socket *so,
14054     struct tcpcb *tp, int32_t drop_hdrlen, int32_t tlen, uint8_t iptos,
14055     int32_t nxt_pkt, struct timeval *tv)
14056 {
14057 	struct inpcb *inp = tptoinpcb(tp);
14058 #ifdef TCP_ACCOUNTING
14059 	uint64_t ts_val;
14060 #endif
14061 	int32_t thflags, retval, did_out = 0;
14062 	int32_t way_out = 0;
14063 	/*
14064 	 * cts - is the current time from tv (caller gets ts) in microseconds.
14065 	 * ms_cts - is the current time from tv in milliseconds.
14066 	 * us_cts - is the time that LRO or hardware actually got the packet in microseconds.
14067 	 */
14068 	uint32_t cts, us_cts, ms_cts;
14069 	uint32_t tiwin, high_seq;
14070 	struct timespec ts;
14071 	struct tcpopt to;
14072 	struct tcp_rack *rack;
14073 	struct rack_sendmap *rsm;
14074 	int32_t prev_state = 0;
14075 #ifdef TCP_ACCOUNTING
14076 	int ack_val_set = 0xf;
14077 #endif
14078 	int nsegs;
14079 
14080 	NET_EPOCH_ASSERT();
14081 	INP_WLOCK_ASSERT(inp);
14082 
14083 	/*
14084 	 * tv passed from common code is from either M_TSTMP_LRO or
14085 	 * tcp_get_usecs() if no LRO m_pkthdr timestamp is present.
14086 	 */
14087 	rack = (struct tcp_rack *)tp->t_fb_ptr;
14088 	if (m->m_flags & M_ACKCMP) {
14089 		/*
14090 		 * All compressed ack's are ack's by definition so
14091 		 * remove any ack required flag and then do the processing.
14092 		 */
14093 		rack->rc_ack_required = 0;
14094 		return (rack_do_compressed_ack_processing(tp, so, m, nxt_pkt, tv));
14095 	}
14096 	if (m->m_flags & M_ACKCMP) {
14097 		panic("Impossible reach m has ackcmp? m:%p tp:%p", m, tp);
14098 	}
14099 	cts = tcp_tv_to_usectick(tv);
14100 	ms_cts =  tcp_tv_to_mssectick(tv);
14101 	nsegs = m->m_pkthdr.lro_nsegs;
14102 	counter_u64_add(rack_proc_non_comp_ack, 1);
14103 	thflags = tcp_get_flags(th);
14104 #ifdef TCP_ACCOUNTING
14105 	sched_pin();
14106 	if (thflags & TH_ACK)
14107 		ts_val = get_cyclecount();
14108 #endif
14109 	if ((m->m_flags & M_TSTMP) ||
14110 	    (m->m_flags & M_TSTMP_LRO)) {
14111 		mbuf_tstmp2timespec(m, &ts);
14112 		rack->r_ctl.act_rcv_time.tv_sec = ts.tv_sec;
14113 		rack->r_ctl.act_rcv_time.tv_usec = ts.tv_nsec/1000;
14114 	} else
14115 		rack->r_ctl.act_rcv_time = *tv;
14116 	kern_prefetch(rack, &prev_state);
14117 	prev_state = 0;
14118 	/*
14119 	 * Unscale the window into a 32-bit value. For the SYN_SENT state
14120 	 * the scale is zero.
14121 	 */
14122 	tiwin = th->th_win << tp->snd_scale;
14123 #ifdef TCP_ACCOUNTING
14124 	if (thflags & TH_ACK) {
14125 		/*
14126 		 * We have a tradeoff here. We can either do what we are
14127 		 * doing i.e. pinning to this CPU and then doing the accounting
14128 		 * <or> we could do a critical enter, setup the rdtsc and cpu
14129 		 * as in below, and then validate we are on the same CPU on
14130 		 * exit. I have choosen to not do the critical enter since
14131 		 * that often will gain you a context switch, and instead lock
14132 		 * us (line above this if) to the same CPU with sched_pin(). This
14133 		 * means we may be context switched out for a higher priority
14134 		 * interupt but we won't be moved to another CPU.
14135 		 *
14136 		 * If this occurs (which it won't very often since we most likely
14137 		 * are running this code in interupt context and only a higher
14138 		 * priority will bump us ... clock?) we will falsely add in
14139 		 * to the time the interupt processing time plus the ack processing
14140 		 * time. This is ok since its a rare event.
14141 		 */
14142 		ack_val_set = tcp_do_ack_accounting(tp, th, &to, tiwin,
14143 						    ctf_fixed_maxseg(tp));
14144 	}
14145 #endif
14146 	/*
14147 	 * Parse options on any incoming segment.
14148 	 */
14149 	memset(&to, 0, sizeof(to));
14150 	tcp_dooptions(&to, (u_char *)(th + 1),
14151 	    (th->th_off << 2) - sizeof(struct tcphdr),
14152 	    (thflags & TH_SYN) ? TO_SYN : 0);
14153 	KASSERT(tp->t_state > TCPS_LISTEN, ("%s: TCPS_LISTEN",
14154 	    __func__));
14155 	KASSERT(tp->t_state != TCPS_TIME_WAIT, ("%s: TCPS_TIME_WAIT",
14156 	    __func__));
14157 
14158 	if ((tp->t_state >= TCPS_FIN_WAIT_1) &&
14159 	    (tp->t_flags & TF_GPUTINPROG)) {
14160 		/*
14161 		 * We have a goodput in progress
14162 		 * and we have entered a late state.
14163 		 * Do we have enough data in the sb
14164 		 * to handle the GPUT request?
14165 		 */
14166 		uint32_t bytes;
14167 
14168 		bytes = tp->gput_ack - tp->gput_seq;
14169 		if (SEQ_GT(tp->gput_seq, tp->snd_una))
14170 			bytes += tp->gput_seq - tp->snd_una;
14171 		if (bytes > sbavail(&tptosocket(tp)->so_snd)) {
14172 			/*
14173 			 * There are not enough bytes in the socket
14174 			 * buffer that have been sent to cover this
14175 			 * measurement. Cancel it.
14176 			 */
14177 			rack_log_pacing_delay_calc(rack, (tp->gput_ack - tp->gput_seq) /*flex2*/,
14178 						   rack->r_ctl.rc_gp_srtt /*flex1*/,
14179 						   tp->gput_seq,
14180 						   0, 0, 18, __LINE__, NULL, 0);
14181 			tp->t_flags &= ~TF_GPUTINPROG;
14182 		}
14183 	}
14184 	high_seq = th->th_ack;
14185 	if (tp->t_logstate != TCP_LOG_STATE_OFF) {
14186 		union tcp_log_stackspecific log;
14187 		struct timeval ltv;
14188 #ifdef NETFLIX_HTTP_LOGGING
14189 		struct http_sendfile_track *http_req;
14190 
14191 		if (SEQ_GT(th->th_ack, tp->snd_una)) {
14192 			http_req = tcp_http_find_req_for_seq(tp, (th->th_ack-1));
14193 		} else {
14194 			http_req = tcp_http_find_req_for_seq(tp, th->th_ack);
14195 		}
14196 #endif
14197 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
14198 		log.u_bbr.inhpts = tcp_in_hpts(rack->rc_inp);
14199 		if (rack->rack_no_prr == 0)
14200 			log.u_bbr.flex1 = rack->r_ctl.rc_prr_sndcnt;
14201 		else
14202 			log.u_bbr.flex1 = 0;
14203 		log.u_bbr.use_lt_bw = rack->r_ent_rec_ns;
14204 		log.u_bbr.use_lt_bw <<= 1;
14205 		log.u_bbr.use_lt_bw |= rack->r_might_revert;
14206 		log.u_bbr.flex2 = rack->r_ctl.rc_num_maps_alloced;
14207 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
14208 		log.u_bbr.pkts_out = rack->rc_tp->t_maxseg;
14209 		log.u_bbr.flex3 = m->m_flags;
14210 		log.u_bbr.flex4 = rack->r_ctl.rc_hpts_flags;
14211 		log.u_bbr.lost = thflags;
14212 		log.u_bbr.pacing_gain = 0x1;
14213 #ifdef TCP_ACCOUNTING
14214 		log.u_bbr.cwnd_gain = ack_val_set;
14215 #endif
14216 		log.u_bbr.flex7 = 2;
14217 		if (m->m_flags & M_TSTMP) {
14218 			/* Record the hardware timestamp if present */
14219 			mbuf_tstmp2timespec(m, &ts);
14220 			ltv.tv_sec = ts.tv_sec;
14221 			ltv.tv_usec = ts.tv_nsec / 1000;
14222 			log.u_bbr.lt_epoch = tcp_tv_to_usectick(&ltv);
14223 		} else if (m->m_flags & M_TSTMP_LRO) {
14224 			/* Record the LRO the arrival timestamp */
14225 			mbuf_tstmp2timespec(m, &ts);
14226 			ltv.tv_sec = ts.tv_sec;
14227 			ltv.tv_usec = ts.tv_nsec / 1000;
14228 			log.u_bbr.flex5 = tcp_tv_to_usectick(&ltv);
14229 		}
14230 		log.u_bbr.timeStamp = tcp_get_usecs(&ltv);
14231 		/* Log the rcv time */
14232 		log.u_bbr.delRate = m->m_pkthdr.rcv_tstmp;
14233 #ifdef NETFLIX_HTTP_LOGGING
14234 		log.u_bbr.applimited = tp->t_http_closed;
14235 		log.u_bbr.applimited <<= 8;
14236 		log.u_bbr.applimited |= tp->t_http_open;
14237 		log.u_bbr.applimited <<= 8;
14238 		log.u_bbr.applimited |= tp->t_http_req;
14239 		if (http_req) {
14240 			/* Copy out any client req info */
14241 			/* seconds */
14242 			log.u_bbr.pkt_epoch = (http_req->localtime / HPTS_USEC_IN_SEC);
14243 			/* useconds */
14244 			log.u_bbr.delivered = (http_req->localtime % HPTS_USEC_IN_SEC);
14245 			log.u_bbr.rttProp = http_req->timestamp;
14246 			log.u_bbr.cur_del_rate = http_req->start;
14247 			if (http_req->flags & TCP_HTTP_TRACK_FLG_OPEN) {
14248 				log.u_bbr.flex8 |= 1;
14249 			} else {
14250 				log.u_bbr.flex8 |= 2;
14251 				log.u_bbr.bw_inuse = http_req->end;
14252 			}
14253 			log.u_bbr.flex6 = http_req->start_seq;
14254 			if (http_req->flags & TCP_HTTP_TRACK_FLG_COMP) {
14255 				log.u_bbr.flex8 |= 4;
14256 				log.u_bbr.epoch = http_req->end_seq;
14257 			}
14258 		}
14259 #endif
14260 		TCP_LOG_EVENTP(tp, th, &so->so_rcv, &so->so_snd, TCP_LOG_IN, 0,
14261 		    tlen, &log, true, &ltv);
14262 	}
14263 	/* Remove ack required flag if set, we have one  */
14264 	if (thflags & TH_ACK)
14265 		rack->rc_ack_required = 0;
14266 	if ((thflags & TH_SYN) && (thflags & TH_FIN) && V_drop_synfin) {
14267 		way_out = 4;
14268 		retval = 0;
14269 		m_freem(m);
14270 		goto done_with_input;
14271 	}
14272 	/*
14273 	 * If a segment with the ACK-bit set arrives in the SYN-SENT state
14274 	 * check SEQ.ACK first as described on page 66 of RFC 793, section 3.9.
14275 	 */
14276 	if ((tp->t_state == TCPS_SYN_SENT) && (thflags & TH_ACK) &&
14277 	    (SEQ_LEQ(th->th_ack, tp->iss) || SEQ_GT(th->th_ack, tp->snd_max))) {
14278 		tcp_log_end_status(tp, TCP_EI_STATUS_RST_IN_FRONT);
14279 		ctf_do_dropwithreset(m, tp, th, BANDLIM_RST_OPENPORT, tlen);
14280 #ifdef TCP_ACCOUNTING
14281 		sched_unpin();
14282 #endif
14283 		return (1);
14284 	}
14285 	/*
14286 	 * If timestamps were negotiated during SYN/ACK and a
14287 	 * segment without a timestamp is received, silently drop
14288 	 * the segment, unless it is a RST segment or missing timestamps are
14289 	 * tolerated.
14290 	 * See section 3.2 of RFC 7323.
14291 	 */
14292 	if ((tp->t_flags & TF_RCVD_TSTMP) && !(to.to_flags & TOF_TS) &&
14293 	    ((thflags & TH_RST) == 0) && (V_tcp_tolerate_missing_ts == 0)) {
14294 		way_out = 5;
14295 		retval = 0;
14296 		m_freem(m);
14297 		goto done_with_input;
14298 	}
14299 
14300 	/*
14301 	 * Segment received on connection. Reset idle time and keep-alive
14302 	 * timer. XXX: This should be done after segment validation to
14303 	 * ignore broken/spoofed segs.
14304 	 */
14305 	if  (tp->t_idle_reduce &&
14306 	     (tp->snd_max == tp->snd_una) &&
14307 	     (TICKS_2_USEC(ticks - tp->t_rcvtime) >= tp->t_rxtcur)) {
14308 		counter_u64_add(rack_input_idle_reduces, 1);
14309 		rack_cc_after_idle(rack, tp);
14310 	}
14311 	tp->t_rcvtime = ticks;
14312 #ifdef STATS
14313 	stats_voi_update_abs_ulong(tp->t_stats, VOI_TCP_FRWIN, tiwin);
14314 #endif
14315 	if (tiwin > rack->r_ctl.rc_high_rwnd)
14316 		rack->r_ctl.rc_high_rwnd = tiwin;
14317 	/*
14318 	 * TCP ECN processing. XXXJTL: If we ever use ECN, we need to move
14319 	 * this to occur after we've validated the segment.
14320 	 */
14321 	if (tcp_ecn_input_segment(tp, thflags, tlen,
14322 	    tcp_packets_this_ack(tp, th->th_ack),
14323 	    iptos))
14324 		rack_cong_signal(tp, CC_ECN, th->th_ack, __LINE__);
14325 
14326 	/*
14327 	 * If echoed timestamp is later than the current time, fall back to
14328 	 * non RFC1323 RTT calculation.  Normalize timestamp if syncookies
14329 	 * were used when this connection was established.
14330 	 */
14331 	if ((to.to_flags & TOF_TS) && (to.to_tsecr != 0)) {
14332 		to.to_tsecr -= tp->ts_offset;
14333 		if (TSTMP_GT(to.to_tsecr, ms_cts))
14334 			to.to_tsecr = 0;
14335 	}
14336 
14337 	/*
14338 	 * If its the first time in we need to take care of options and
14339 	 * verify we can do SACK for rack!
14340 	 */
14341 	if (rack->r_state == 0) {
14342 		/* Should be init'd by rack_init() */
14343 		KASSERT(rack->rc_inp != NULL,
14344 		    ("%s: rack->rc_inp unexpectedly NULL", __func__));
14345 		if (rack->rc_inp == NULL) {
14346 			rack->rc_inp = inp;
14347 		}
14348 
14349 		/*
14350 		 * Process options only when we get SYN/ACK back. The SYN
14351 		 * case for incoming connections is handled in tcp_syncache.
14352 		 * According to RFC1323 the window field in a SYN (i.e., a
14353 		 * <SYN> or <SYN,ACK>) segment itself is never scaled. XXX
14354 		 * this is traditional behavior, may need to be cleaned up.
14355 		 */
14356 		if (tp->t_state == TCPS_SYN_SENT && (thflags & TH_SYN)) {
14357 			/* Handle parallel SYN for ECN */
14358 			tcp_ecn_input_parallel_syn(tp, thflags, iptos);
14359 			if ((to.to_flags & TOF_SCALE) &&
14360 			    (tp->t_flags & TF_REQ_SCALE)) {
14361 				tp->t_flags |= TF_RCVD_SCALE;
14362 				tp->snd_scale = to.to_wscale;
14363 			} else
14364 				tp->t_flags &= ~TF_REQ_SCALE;
14365 			/*
14366 			 * Initial send window.  It will be updated with the
14367 			 * next incoming segment to the scaled value.
14368 			 */
14369 			tp->snd_wnd = th->th_win;
14370 			rack_validate_fo_sendwin_up(tp, rack);
14371 			if ((to.to_flags & TOF_TS) &&
14372 			    (tp->t_flags & TF_REQ_TSTMP)) {
14373 				tp->t_flags |= TF_RCVD_TSTMP;
14374 				tp->ts_recent = to.to_tsval;
14375 				tp->ts_recent_age = cts;
14376 			} else
14377 				tp->t_flags &= ~TF_REQ_TSTMP;
14378 			if (to.to_flags & TOF_MSS) {
14379 				tcp_mss(tp, to.to_mss);
14380 			}
14381 			if ((tp->t_flags & TF_SACK_PERMIT) &&
14382 			    (to.to_flags & TOF_SACKPERM) == 0)
14383 				tp->t_flags &= ~TF_SACK_PERMIT;
14384 			if (IS_FASTOPEN(tp->t_flags)) {
14385 				if (to.to_flags & TOF_FASTOPEN) {
14386 					uint16_t mss;
14387 
14388 					if (to.to_flags & TOF_MSS)
14389 						mss = to.to_mss;
14390 					else
14391 						if ((inp->inp_vflag & INP_IPV6) != 0)
14392 							mss = TCP6_MSS;
14393 						else
14394 							mss = TCP_MSS;
14395 					tcp_fastopen_update_cache(tp, mss,
14396 					    to.to_tfo_len, to.to_tfo_cookie);
14397 				} else
14398 					tcp_fastopen_disable_path(tp);
14399 			}
14400 		}
14401 		/*
14402 		 * At this point we are at the initial call. Here we decide
14403 		 * if we are doing RACK or not. We do this by seeing if
14404 		 * TF_SACK_PERMIT is set and the sack-not-required is clear.
14405 		 * The code now does do dup-ack counting so if you don't
14406 		 * switch back you won't get rack & TLP, but you will still
14407 		 * get this stack.
14408 		 */
14409 
14410 		if ((rack_sack_not_required == 0) &&
14411 		    ((tp->t_flags & TF_SACK_PERMIT) == 0)) {
14412 			tcp_switch_back_to_default(tp);
14413 			(*tp->t_fb->tfb_tcp_do_segment) (m, th, so, tp, drop_hdrlen,
14414 			    tlen, iptos);
14415 #ifdef TCP_ACCOUNTING
14416 			sched_unpin();
14417 #endif
14418 			return (1);
14419 		}
14420 		tcp_set_hpts(inp);
14421 		sack_filter_clear(&rack->r_ctl.rack_sf, th->th_ack);
14422 	}
14423 	if (thflags & TH_FIN)
14424 		tcp_log_end_status(tp, TCP_EI_STATUS_CLIENT_FIN);
14425 	us_cts = tcp_tv_to_usectick(&rack->r_ctl.act_rcv_time);
14426 	if ((rack->rc_gp_dyn_mul) &&
14427 	    (rack->use_fixed_rate == 0) &&
14428 	    (rack->rc_always_pace)) {
14429 		/* Check in on probertt */
14430 		rack_check_probe_rtt(rack, us_cts);
14431 	}
14432 	rack_clear_rate_sample(rack);
14433 	if ((rack->forced_ack) &&
14434 	    ((tcp_get_flags(th) & TH_RST) == 0)) {
14435 		rack_handle_probe_response(rack, tiwin, us_cts);
14436 	}
14437 	/*
14438 	 * This is the one exception case where we set the rack state
14439 	 * always. All other times (timers etc) we must have a rack-state
14440 	 * set (so we assure we have done the checks above for SACK).
14441 	 */
14442 	rack->r_ctl.rc_rcvtime = cts;
14443 	if (rack->r_state != tp->t_state)
14444 		rack_set_state(tp, rack);
14445 	if (SEQ_GT(th->th_ack, tp->snd_una) &&
14446 	    (rsm = RB_MIN(rack_rb_tree_head, &rack->r_ctl.rc_mtree)) != NULL)
14447 		kern_prefetch(rsm, &prev_state);
14448 	prev_state = rack->r_state;
14449 	retval = (*rack->r_substate) (m, th, so,
14450 	    tp, &to, drop_hdrlen,
14451 	    tlen, tiwin, thflags, nxt_pkt, iptos);
14452 	if (retval == 0) {
14453 		/*
14454 		 * If retval is 1 the tcb is unlocked and most likely the tp
14455 		 * is gone.
14456 		 */
14457 		INP_WLOCK_ASSERT(inp);
14458 		if ((rack->rc_gp_dyn_mul) &&
14459 		    (rack->rc_always_pace) &&
14460 		    (rack->use_fixed_rate == 0) &&
14461 		    rack->in_probe_rtt &&
14462 		    (rack->r_ctl.rc_time_probertt_starts == 0)) {
14463 			/*
14464 			 * If we are going for target, lets recheck before
14465 			 * we output.
14466 			 */
14467 			rack_check_probe_rtt(rack, us_cts);
14468 		}
14469 		if (rack->set_pacing_done_a_iw == 0) {
14470 			/* How much has been acked? */
14471 			if ((tp->snd_una - tp->iss) > (ctf_fixed_maxseg(tp) * 10)) {
14472 				/* We have enough to set in the pacing segment size */
14473 				rack->set_pacing_done_a_iw = 1;
14474 				rack_set_pace_segments(tp, rack, __LINE__, NULL);
14475 			}
14476 		}
14477 		tcp_rack_xmit_timer_commit(rack, tp);
14478 #ifdef TCP_ACCOUNTING
14479 		/*
14480 		 * If we set the ack_val_se to what ack processing we are doing
14481 		 * we also want to track how many cycles we burned. Note
14482 		 * the bits after tcp_output we let be "free". This is because
14483 		 * we are also tracking the tcp_output times as well. Note the
14484 		 * use of 0xf here since we only have 11 counter (0 - 0xa) and
14485 		 * 0xf cannot be returned and is what we initialize it too to
14486 		 * indicate we are not doing the tabulations.
14487 		 */
14488 		if (ack_val_set != 0xf) {
14489 			uint64_t crtsc;
14490 
14491 			crtsc = get_cyclecount();
14492 			counter_u64_add(tcp_proc_time[ack_val_set] , (crtsc - ts_val));
14493 			if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
14494 				tp->tcp_proc_time[ack_val_set] += (crtsc - ts_val);
14495 			}
14496 		}
14497 #endif
14498 		if (nxt_pkt == 0) {
14499 			if ((rack->r_wanted_output != 0) || (rack->r_fast_output != 0)) {
14500 do_output_now:
14501 				if (tcp_output(tp) < 0)
14502 					return (1);
14503 				did_out = 1;
14504 			}
14505 			rack_start_hpts_timer(rack, tp, cts, 0, 0, 0);
14506 			rack_free_trim(rack);
14507 		}
14508 		/* Update any rounds needed */
14509 		if (rack_verbose_logging &&  (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF)) {
14510 			union tcp_log_stackspecific log;
14511 			struct timeval tv;
14512 
14513 			memset(&log.u_bbr, 0, sizeof(log.u_bbr));
14514 			log.u_bbr.timeStamp = tcp_get_usecs(&tv);
14515 			log.u_bbr.flex1 = high_seq;
14516 			log.u_bbr.flex2 = rack->r_ctl.roundends;
14517 			log.u_bbr.flex3 = rack->r_ctl.current_round;
14518 			log.u_bbr.rttProp = (uint64_t)CC_ALGO(tp)->newround;
14519 			log.u_bbr.flex8 = 9;
14520 			tcp_log_event_(tp, NULL, NULL, NULL, BBR_LOG_CWND, 0,
14521 				       0, &log, false, NULL, NULL, 0, &tv);
14522 		}
14523 		/*
14524 		 * The draft (v3) calls for us to use SEQ_GEQ, but that
14525 		 * causes issues when we are just going app limited. Lets
14526 		 * instead use SEQ_GT <or> where its equal but more data
14527 		 * is outstanding.
14528 		 */
14529 		if ((SEQ_GT(tp->snd_una, rack->r_ctl.roundends)) ||
14530 		    ((tp->snd_una == rack->r_ctl.roundends) && SEQ_GT(tp->snd_max, tp->snd_una))) {
14531 			rack->r_ctl.current_round++;
14532 			rack->r_ctl.roundends = tp->snd_max;
14533 			if (CC_ALGO(tp)->newround != NULL) {
14534 				CC_ALGO(tp)->newround(tp->ccv, rack->r_ctl.current_round);
14535 			}
14536 		}
14537 		if ((nxt_pkt == 0) &&
14538 		    ((rack->r_ctl.rc_hpts_flags & PACE_TMR_MASK) == 0) &&
14539 		    (SEQ_GT(tp->snd_max, tp->snd_una) ||
14540 		     (tp->t_flags & TF_DELACK) ||
14541 		     ((V_tcp_always_keepalive || rack->rc_inp->inp_socket->so_options & SO_KEEPALIVE) &&
14542 		      (tp->t_state <= TCPS_CLOSING)))) {
14543 			/* We could not send (probably in the hpts but stopped the timer earlier)? */
14544 			if ((tp->snd_max == tp->snd_una) &&
14545 			    ((tp->t_flags & TF_DELACK) == 0) &&
14546 			    (tcp_in_hpts(rack->rc_inp)) &&
14547 			    (rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT)) {
14548 				/* keep alive not needed if we are hptsi output yet */
14549 				;
14550 			} else {
14551 				int late = 0;
14552 				if (tcp_in_hpts(inp)) {
14553 					if (rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT) {
14554 						us_cts = tcp_get_usecs(NULL);
14555 						if (TSTMP_GT(rack->r_ctl.rc_last_output_to, us_cts)) {
14556 							rack->r_early = 1;
14557 							rack->r_ctl.rc_agg_early += (rack->r_ctl.rc_last_output_to - us_cts);
14558 						} else
14559 							late = 1;
14560 						rack->r_ctl.rc_hpts_flags &= ~PACE_PKT_OUTPUT;
14561 					}
14562 					tcp_hpts_remove(inp);
14563 				}
14564 				if (late && (did_out == 0)) {
14565 					/*
14566 					 * We are late in the sending
14567 					 * and we did not call the output
14568 					 * (this probably should not happen).
14569 					 */
14570 					goto do_output_now;
14571 				}
14572 				rack_start_hpts_timer(rack, tp, tcp_get_usecs(NULL), 0, 0, 0);
14573 			}
14574 			way_out = 1;
14575 		} else if (nxt_pkt == 0) {
14576 			/* Do we have the correct timer running? */
14577 			rack_timer_audit(tp, rack, &so->so_snd);
14578 			way_out = 2;
14579 		}
14580 	done_with_input:
14581 		rack_log_doseg_done(rack, cts, nxt_pkt, did_out, way_out, max(1, nsegs));
14582 		if (did_out)
14583 			rack->r_wanted_output = 0;
14584 #ifdef TCP_ACCOUNTING
14585 	} else {
14586 		/*
14587 		 * Track the time (see above).
14588 		 */
14589 		if (ack_val_set != 0xf) {
14590 			uint64_t crtsc;
14591 
14592 			crtsc = get_cyclecount();
14593 			counter_u64_add(tcp_proc_time[ack_val_set] , (crtsc - ts_val));
14594 			/*
14595 			 * Note we *DO NOT* increment the per-tcb counters since
14596 			 * in the else the TP may be gone!!
14597 			 */
14598 		}
14599 #endif
14600 	}
14601 #ifdef TCP_ACCOUNTING
14602 	sched_unpin();
14603 #endif
14604 	return (retval);
14605 }
14606 
14607 void
14608 rack_do_segment(struct mbuf *m, struct tcphdr *th, struct socket *so,
14609     struct tcpcb *tp, int32_t drop_hdrlen, int32_t tlen, uint8_t iptos)
14610 {
14611 	struct timeval tv;
14612 
14613 	/* First lets see if we have old packets */
14614 	if (tp->t_in_pkt) {
14615 		if (ctf_do_queued_segments(so, tp, 1)) {
14616 			m_freem(m);
14617 			return;
14618 		}
14619 	}
14620 	if (m->m_flags & M_TSTMP_LRO) {
14621 		mbuf_tstmp2timeval(m, &tv);
14622 	} else {
14623 		/* Should not be should we kassert instead? */
14624 		tcp_get_usecs(&tv);
14625 	}
14626 	if (rack_do_segment_nounlock(m, th, so, tp,
14627 				     drop_hdrlen, tlen, iptos, 0, &tv) == 0) {
14628 		INP_WUNLOCK(tptoinpcb(tp));
14629 	}
14630 }
14631 
14632 struct rack_sendmap *
14633 tcp_rack_output(struct tcpcb *tp, struct tcp_rack *rack, uint32_t tsused)
14634 {
14635 	struct rack_sendmap *rsm = NULL;
14636 	int32_t idx;
14637 	uint32_t srtt = 0, thresh = 0, ts_low = 0;
14638 
14639 	/* Return the next guy to be re-transmitted */
14640 	if (RB_EMPTY(&rack->r_ctl.rc_mtree)) {
14641 		return (NULL);
14642 	}
14643 	if (tp->t_flags & TF_SENTFIN) {
14644 		/* retran the end FIN? */
14645 		return (NULL);
14646 	}
14647 	/* ok lets look at this one */
14648 	rsm = TAILQ_FIRST(&rack->r_ctl.rc_tmap);
14649 	if (rack->r_must_retran && rsm && (rsm->r_flags & RACK_MUST_RXT)) {
14650 		return (rsm);
14651 	}
14652 	if (rsm && ((rsm->r_flags & RACK_ACKED) == 0)) {
14653 		goto check_it;
14654 	}
14655 	rsm = rack_find_lowest_rsm(rack);
14656 	if (rsm == NULL) {
14657 		return (NULL);
14658 	}
14659 check_it:
14660 	if (((rack->rc_tp->t_flags & TF_SACK_PERMIT) == 0) &&
14661 	    (rsm->r_dupack >= DUP_ACK_THRESHOLD)) {
14662 		/*
14663 		 * No sack so we automatically do the 3 strikes and
14664 		 * retransmit (no rack timer would be started).
14665 		 */
14666 
14667 		return (rsm);
14668 	}
14669 	if (rsm->r_flags & RACK_ACKED) {
14670 		return (NULL);
14671 	}
14672 	if (((rsm->r_flags & RACK_SACK_PASSED) == 0) &&
14673 	    (rsm->r_dupack < DUP_ACK_THRESHOLD)) {
14674 		/* Its not yet ready */
14675 		return (NULL);
14676 	}
14677 	srtt = rack_grab_rtt(tp, rack);
14678 	idx = rsm->r_rtr_cnt - 1;
14679 	ts_low = (uint32_t)rsm->r_tim_lastsent[idx];
14680 	thresh = rack_calc_thresh_rack(rack, srtt, tsused);
14681 	if ((tsused == ts_low) ||
14682 	    (TSTMP_LT(tsused, ts_low))) {
14683 		/* No time since sending */
14684 		return (NULL);
14685 	}
14686 	if ((tsused - ts_low) < thresh) {
14687 		/* It has not been long enough yet */
14688 		return (NULL);
14689 	}
14690 	if ((rsm->r_dupack >= DUP_ACK_THRESHOLD) ||
14691 	    ((rsm->r_flags & RACK_SACK_PASSED) &&
14692 	     (rack->sack_attack_disable == 0))) {
14693 		/*
14694 		 * We have passed the dup-ack threshold <or>
14695 		 * a SACK has indicated this is missing.
14696 		 * Note that if you are a declared attacker
14697 		 * it is only the dup-ack threshold that
14698 		 * will cause retransmits.
14699 		 */
14700 		/* log retransmit reason */
14701 		rack_log_retran_reason(rack, rsm, (tsused - ts_low), thresh, 1);
14702 		rack->r_fast_output = 0;
14703 		return (rsm);
14704 	}
14705 	return (NULL);
14706 }
14707 
14708 static void
14709 rack_log_pacing_delay_calc(struct tcp_rack *rack, uint32_t len, uint32_t slot,
14710 			   uint64_t bw_est, uint64_t bw, uint64_t len_time, int method,
14711 			   int line, struct rack_sendmap *rsm, uint8_t quality)
14712 {
14713 	if (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
14714 		union tcp_log_stackspecific log;
14715 		struct timeval tv;
14716 
14717 		memset(&log, 0, sizeof(log));
14718 		log.u_bbr.flex1 = slot;
14719 		log.u_bbr.flex2 = len;
14720 		log.u_bbr.flex3 = rack->r_ctl.rc_pace_min_segs;
14721 		log.u_bbr.flex4 = rack->r_ctl.rc_pace_max_segs;
14722 		log.u_bbr.flex5 = rack->r_ctl.rack_per_of_gp_ss;
14723 		log.u_bbr.flex6 = rack->r_ctl.rack_per_of_gp_ca;
14724 		log.u_bbr.use_lt_bw = rack->rc_ack_can_sendout_data;
14725 		log.u_bbr.use_lt_bw <<= 1;
14726 		log.u_bbr.use_lt_bw |= rack->r_late;
14727 		log.u_bbr.use_lt_bw <<= 1;
14728 		log.u_bbr.use_lt_bw |= rack->r_early;
14729 		log.u_bbr.use_lt_bw <<= 1;
14730 		log.u_bbr.use_lt_bw |= rack->app_limited_needs_set;
14731 		log.u_bbr.use_lt_bw <<= 1;
14732 		log.u_bbr.use_lt_bw |= rack->rc_gp_filled;
14733 		log.u_bbr.use_lt_bw <<= 1;
14734 		log.u_bbr.use_lt_bw |= rack->measure_saw_probe_rtt;
14735 		log.u_bbr.use_lt_bw <<= 1;
14736 		log.u_bbr.use_lt_bw |= rack->in_probe_rtt;
14737 		log.u_bbr.use_lt_bw <<= 1;
14738 		log.u_bbr.use_lt_bw |= rack->gp_ready;
14739 		log.u_bbr.pkt_epoch = line;
14740 		log.u_bbr.epoch = rack->r_ctl.rc_agg_delayed;
14741 		log.u_bbr.lt_epoch = rack->r_ctl.rc_agg_early;
14742 		log.u_bbr.applimited = rack->r_ctl.rack_per_of_gp_rec;
14743 		log.u_bbr.bw_inuse = bw_est;
14744 		log.u_bbr.delRate = bw;
14745 		if (rack->r_ctl.gp_bw == 0)
14746 			log.u_bbr.cur_del_rate = 0;
14747 		else
14748 			log.u_bbr.cur_del_rate = rack_get_bw(rack);
14749 		log.u_bbr.rttProp = len_time;
14750 		log.u_bbr.pkts_out = rack->r_ctl.rc_rack_min_rtt;
14751 		log.u_bbr.lost = rack->r_ctl.rc_probertt_sndmax_atexit;
14752 		log.u_bbr.pacing_gain = rack_get_output_gain(rack, rsm);
14753 		if (rack->r_ctl.cwnd_to_use < rack->rc_tp->snd_ssthresh) {
14754 			/* We are in slow start */
14755 			log.u_bbr.flex7 = 1;
14756 		} else {
14757 			/* we are on congestion avoidance */
14758 			log.u_bbr.flex7 = 0;
14759 		}
14760 		log.u_bbr.flex8 = method;
14761 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
14762 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
14763 		log.u_bbr.cwnd_gain = rack->rc_gp_saw_rec;
14764 		log.u_bbr.cwnd_gain <<= 1;
14765 		log.u_bbr.cwnd_gain |= rack->rc_gp_saw_ss;
14766 		log.u_bbr.cwnd_gain <<= 1;
14767 		log.u_bbr.cwnd_gain |= rack->rc_gp_saw_ca;
14768 		log.u_bbr.bbr_substate = quality;
14769 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
14770 		    &rack->rc_inp->inp_socket->so_rcv,
14771 		    &rack->rc_inp->inp_socket->so_snd,
14772 		    BBR_LOG_HPTSI_CALC, 0,
14773 		    0, &log, false, &tv);
14774 	}
14775 }
14776 
14777 static uint32_t
14778 rack_get_pacing_len(struct tcp_rack *rack, uint64_t bw, uint32_t mss)
14779 {
14780 	uint32_t new_tso, user_max;
14781 
14782 	user_max = rack->rc_user_set_max_segs * mss;
14783 	if (rack->rc_force_max_seg) {
14784 		return (user_max);
14785 	}
14786 	if (rack->use_fixed_rate &&
14787 	    ((rack->r_ctl.crte == NULL) ||
14788 	     (bw != rack->r_ctl.crte->rate))) {
14789 		/* Use the user mss since we are not exactly matched */
14790 		return (user_max);
14791 	}
14792 	new_tso = tcp_get_pacing_burst_size(rack->rc_tp, bw, mss, rack_pace_one_seg, rack->r_ctl.crte, NULL);
14793 	if (new_tso > user_max)
14794 		new_tso = user_max;
14795 	return (new_tso);
14796 }
14797 
14798 static int32_t
14799 pace_to_fill_cwnd(struct tcp_rack *rack, int32_t slot, uint32_t len, uint32_t segsiz, int *capped, uint64_t *rate_wanted, uint8_t non_paced)
14800 {
14801 	uint64_t lentim, fill_bw;
14802 
14803 	/* Lets first see if we are full, if so continue with normal rate */
14804 	rack->r_via_fill_cw = 0;
14805 	if (ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked) > rack->r_ctl.cwnd_to_use)
14806 		return (slot);
14807 	if ((ctf_outstanding(rack->rc_tp) + (segsiz-1)) > rack->rc_tp->snd_wnd)
14808 		return (slot);
14809 	if (rack->r_ctl.rc_last_us_rtt == 0)
14810 		return (slot);
14811 	if (rack->rc_pace_fill_if_rttin_range &&
14812 	    (rack->r_ctl.rc_last_us_rtt >=
14813 	     (get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt) * rack->rtt_limit_mul))) {
14814 		/* The rtt is huge, N * smallest, lets not fill */
14815 		return (slot);
14816 	}
14817 	/*
14818 	 * first lets calculate the b/w based on the last us-rtt
14819 	 * and the sndwnd.
14820 	 */
14821 	fill_bw = rack->r_ctl.cwnd_to_use;
14822 	/* Take the rwnd if its smaller */
14823 	if (fill_bw > rack->rc_tp->snd_wnd)
14824 		fill_bw = rack->rc_tp->snd_wnd;
14825 	if (rack->r_fill_less_agg) {
14826 		/*
14827 		 * Now take away the inflight (this will reduce our
14828 		 * aggressiveness and yeah, if we get that much out in 1RTT
14829 		 * we will have had acks come back and still be behind).
14830 		 */
14831 		fill_bw -= ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
14832 	}
14833 	/* Now lets make it into a b/w */
14834 	fill_bw *= (uint64_t)HPTS_USEC_IN_SEC;
14835 	fill_bw /= (uint64_t)rack->r_ctl.rc_last_us_rtt;
14836 	/* We are below the min b/w */
14837 	if (non_paced)
14838 		*rate_wanted = fill_bw;
14839 	if ((fill_bw < RACK_MIN_BW) || (fill_bw < *rate_wanted))
14840 		return (slot);
14841 	if (rack->r_ctl.bw_rate_cap && (fill_bw > rack->r_ctl.bw_rate_cap))
14842 		fill_bw = rack->r_ctl.bw_rate_cap;
14843 	rack->r_via_fill_cw = 1;
14844 	if (rack->r_rack_hw_rate_caps &&
14845 	    (rack->r_ctl.crte != NULL)) {
14846 		uint64_t high_rate;
14847 
14848 		high_rate = tcp_hw_highest_rate(rack->r_ctl.crte);
14849 		if (fill_bw > high_rate) {
14850 			/* We are capping bw at the highest rate table entry */
14851 			if (*rate_wanted > high_rate) {
14852 				/* The original rate was also capped */
14853 				rack->r_via_fill_cw = 0;
14854 			}
14855 			rack_log_hdwr_pacing(rack,
14856 					     fill_bw, high_rate, __LINE__,
14857 					     0, 3);
14858 			fill_bw = high_rate;
14859 			if (capped)
14860 				*capped = 1;
14861 		}
14862 	} else if ((rack->r_ctl.crte == NULL) &&
14863 		   (rack->rack_hdrw_pacing == 0) &&
14864 		   (rack->rack_hdw_pace_ena) &&
14865 		   rack->r_rack_hw_rate_caps &&
14866 		   (rack->rack_attempt_hdwr_pace == 0) &&
14867 		   (rack->rc_inp->inp_route.ro_nh != NULL) &&
14868 		   (rack->rc_inp->inp_route.ro_nh->nh_ifp != NULL)) {
14869 		/*
14870 		 * Ok we may have a first attempt that is greater than our top rate
14871 		 * lets check.
14872 		 */
14873 		uint64_t high_rate;
14874 
14875 		high_rate = tcp_hw_highest_rate_ifp(rack->rc_inp->inp_route.ro_nh->nh_ifp, rack->rc_inp);
14876 		if (high_rate) {
14877 			if (fill_bw > high_rate) {
14878 				fill_bw = high_rate;
14879 				if (capped)
14880 					*capped = 1;
14881 			}
14882 		}
14883 	}
14884 	/*
14885 	 * Ok fill_bw holds our mythical b/w to fill the cwnd
14886 	 * in a rtt, what does that time wise equate too?
14887 	 */
14888 	lentim = (uint64_t)(len) * (uint64_t)HPTS_USEC_IN_SEC;
14889 	lentim /= fill_bw;
14890 	*rate_wanted = fill_bw;
14891 	if (non_paced || (lentim < slot)) {
14892 		rack_log_pacing_delay_calc(rack, len, slot, fill_bw,
14893 					   0, lentim, 12, __LINE__, NULL, 0);
14894 		return ((int32_t)lentim);
14895 	} else
14896 		return (slot);
14897 }
14898 
14899 static int32_t
14900 rack_get_pacing_delay(struct tcp_rack *rack, struct tcpcb *tp, uint32_t len, struct rack_sendmap *rsm, uint32_t segsiz)
14901 {
14902 	uint64_t srtt;
14903 	int32_t slot = 0;
14904 	int can_start_hw_pacing = 1;
14905 	int err;
14906 
14907 	if (rack->rc_always_pace == 0) {
14908 		/*
14909 		 * We use the most optimistic possible cwnd/srtt for
14910 		 * sending calculations. This will make our
14911 		 * calculation anticipate getting more through
14912 		 * quicker then possible. But thats ok we don't want
14913 		 * the peer to have a gap in data sending.
14914 		 */
14915 		uint64_t cwnd, tr_perms = 0;
14916 		int32_t reduce = 0;
14917 
14918 	old_method:
14919 		/*
14920 		 * We keep no precise pacing with the old method
14921 		 * instead we use the pacer to mitigate bursts.
14922 		 */
14923 		if (rack->r_ctl.rc_rack_min_rtt)
14924 			srtt = rack->r_ctl.rc_rack_min_rtt;
14925 		else
14926 			srtt = max(tp->t_srtt, 1);
14927 		if (rack->r_ctl.rc_rack_largest_cwnd)
14928 			cwnd = rack->r_ctl.rc_rack_largest_cwnd;
14929 		else
14930 			cwnd = rack->r_ctl.cwnd_to_use;
14931 		/* Inflate cwnd by 1000 so srtt of usecs is in ms */
14932 		tr_perms = (cwnd * 1000) / srtt;
14933 		if (tr_perms == 0) {
14934 			tr_perms = ctf_fixed_maxseg(tp);
14935 		}
14936 		/*
14937 		 * Calculate how long this will take to drain, if
14938 		 * the calculation comes out to zero, thats ok we
14939 		 * will use send_a_lot to possibly spin around for
14940 		 * more increasing tot_len_this_send to the point
14941 		 * that its going to require a pace, or we hit the
14942 		 * cwnd. Which in that case we are just waiting for
14943 		 * a ACK.
14944 		 */
14945 		slot = len / tr_perms;
14946 		/* Now do we reduce the time so we don't run dry? */
14947 		if (slot && rack_slot_reduction) {
14948 			reduce = (slot / rack_slot_reduction);
14949 			if (reduce < slot) {
14950 				slot -= reduce;
14951 			} else
14952 				slot = 0;
14953 		}
14954 		slot *= HPTS_USEC_IN_MSEC;
14955 		if (rack->rc_pace_to_cwnd) {
14956 			uint64_t rate_wanted = 0;
14957 
14958 			slot = pace_to_fill_cwnd(rack, slot, len, segsiz, NULL, &rate_wanted, 1);
14959 			rack->rc_ack_can_sendout_data = 1;
14960 			rack_log_pacing_delay_calc(rack, len, slot, rate_wanted, 0, 0, 14, __LINE__, NULL, 0);
14961 		} else
14962 			rack_log_pacing_delay_calc(rack, len, slot, tr_perms, reduce, 0, 7, __LINE__, NULL, 0);
14963 	} else {
14964 		uint64_t bw_est, res, lentim, rate_wanted;
14965 		uint32_t orig_val, segs, oh;
14966 		int capped = 0;
14967 		int prev_fill;
14968 
14969 		if ((rack->r_rr_config == 1) && rsm) {
14970 			return (rack->r_ctl.rc_min_to);
14971 		}
14972 		if (rack->use_fixed_rate) {
14973 			rate_wanted = bw_est = rack_get_fixed_pacing_bw(rack);
14974 		} else if ((rack->r_ctl.init_rate == 0) &&
14975 #ifdef NETFLIX_PEAKRATE
14976 			   (rack->rc_tp->t_maxpeakrate == 0) &&
14977 #endif
14978 			   (rack->r_ctl.gp_bw == 0)) {
14979 			/* no way to yet do an estimate */
14980 			bw_est = rate_wanted = 0;
14981 		} else {
14982 			bw_est = rack_get_bw(rack);
14983 			rate_wanted = rack_get_output_bw(rack, bw_est, rsm, &capped);
14984 		}
14985 		if ((bw_est == 0) || (rate_wanted == 0) ||
14986 		    ((rack->gp_ready == 0) && (rack->use_fixed_rate == 0))) {
14987 			/*
14988 			 * No way yet to make a b/w estimate or
14989 			 * our raise is set incorrectly.
14990 			 */
14991 			goto old_method;
14992 		}
14993 		/* We need to account for all the overheads */
14994 		segs = (len + segsiz - 1) / segsiz;
14995 		/*
14996 		 * We need the diff between 1514 bytes (e-mtu with e-hdr)
14997 		 * and how much data we put in each packet. Yes this
14998 		 * means we may be off if we are larger than 1500 bytes
14999 		 * or smaller. But this just makes us more conservative.
15000 		 */
15001 		if (rack_hw_rate_min &&
15002 		    (bw_est < rack_hw_rate_min))
15003 			can_start_hw_pacing = 0;
15004 		if (ETHERNET_SEGMENT_SIZE > segsiz)
15005 			oh = ETHERNET_SEGMENT_SIZE - segsiz;
15006 		else
15007 			oh = 0;
15008 		segs *= oh;
15009 		lentim = (uint64_t)(len + segs) * (uint64_t)HPTS_USEC_IN_SEC;
15010 		res = lentim / rate_wanted;
15011 		slot = (uint32_t)res;
15012 		orig_val = rack->r_ctl.rc_pace_max_segs;
15013 		if (rack->r_ctl.crte == NULL) {
15014 			/*
15015 			 * Only do this if we are not hardware pacing
15016 			 * since if we are doing hw-pacing below we will
15017 			 * set make a call after setting up or changing
15018 			 * the rate.
15019 			 */
15020 			rack_set_pace_segments(rack->rc_tp, rack, __LINE__, NULL);
15021 		} else if (rack->rc_inp->inp_snd_tag == NULL) {
15022 			/*
15023 			 * We lost our rate somehow, this can happen
15024 			 * if the interface changed underneath us.
15025 			 */
15026 			tcp_rel_pacing_rate(rack->r_ctl.crte, rack->rc_tp);
15027 			rack->r_ctl.crte = NULL;
15028 			/* Lets re-allow attempting to setup pacing */
15029 			rack->rack_hdrw_pacing = 0;
15030 			rack->rack_attempt_hdwr_pace = 0;
15031 			rack_log_hdwr_pacing(rack,
15032 					     rate_wanted, bw_est, __LINE__,
15033 					     0, 6);
15034 		}
15035 		/* Did we change the TSO size, if so log it */
15036 		if (rack->r_ctl.rc_pace_max_segs != orig_val)
15037 			rack_log_pacing_delay_calc(rack, len, slot, orig_val, 0, 0, 15, __LINE__, NULL, 0);
15038 		prev_fill = rack->r_via_fill_cw;
15039 		if ((rack->rc_pace_to_cwnd) &&
15040 		    (capped == 0) &&
15041 		    (rack->use_fixed_rate == 0) &&
15042 		    (rack->in_probe_rtt == 0) &&
15043 		    (IN_FASTRECOVERY(rack->rc_tp->t_flags) == 0)) {
15044 			/*
15045 			 * We want to pace at our rate *or* faster to
15046 			 * fill the cwnd to the max if its not full.
15047 			 */
15048 			slot = pace_to_fill_cwnd(rack, slot, (len+segs), segsiz, &capped, &rate_wanted, 0);
15049 		}
15050 		if ((rack->rc_inp->inp_route.ro_nh != NULL) &&
15051 		    (rack->rc_inp->inp_route.ro_nh->nh_ifp != NULL)) {
15052 			if ((rack->rack_hdw_pace_ena) &&
15053 			    (can_start_hw_pacing > 0) &&
15054 			    (rack->rack_hdrw_pacing == 0) &&
15055 			    (rack->rack_attempt_hdwr_pace == 0)) {
15056 				/*
15057 				 * Lets attempt to turn on hardware pacing
15058 				 * if we can.
15059 				 */
15060 				rack->rack_attempt_hdwr_pace = 1;
15061 				rack->r_ctl.crte = tcp_set_pacing_rate(rack->rc_tp,
15062 								       rack->rc_inp->inp_route.ro_nh->nh_ifp,
15063 								       rate_wanted,
15064 								       RS_PACING_GEQ,
15065 								       &err, &rack->r_ctl.crte_prev_rate);
15066 				if (rack->r_ctl.crte) {
15067 					rack->rack_hdrw_pacing = 1;
15068 					rack->r_ctl.rc_pace_max_segs = tcp_get_pacing_burst_size(tp, rate_wanted, segsiz,
15069 												 0, rack->r_ctl.crte,
15070 												 NULL);
15071 					rack_log_hdwr_pacing(rack,
15072 							     rate_wanted, rack->r_ctl.crte->rate, __LINE__,
15073 							     err, 0);
15074 					rack->r_ctl.last_hw_bw_req = rate_wanted;
15075 				} else {
15076 					counter_u64_add(rack_hw_pace_init_fail, 1);
15077 				}
15078 			} else if (rack->rack_hdrw_pacing &&
15079 				   (rack->r_ctl.last_hw_bw_req != rate_wanted)) {
15080 				/* Do we need to adjust our rate? */
15081 				const struct tcp_hwrate_limit_table *nrte;
15082 
15083 				if (rack->r_up_only &&
15084 				    (rate_wanted < rack->r_ctl.crte->rate)) {
15085 					/**
15086 					 * We have four possible states here
15087 					 * having to do with the previous time
15088 					 * and this time.
15089 					 *   previous  |  this-time
15090 					 * A)     0      |     0   -- fill_cw not in the picture
15091 					 * B)     1      |     0   -- we were doing a fill-cw but now are not
15092 					 * C)     1      |     1   -- all rates from fill_cw
15093 					 * D)     0      |     1   -- we were doing non-fill and now we are filling
15094 					 *
15095 					 * For case A, C and D we don't allow a drop. But for
15096 					 * case B where we now our on our steady rate we do
15097 					 * allow a drop.
15098 					 *
15099 					 */
15100 					if (!((prev_fill == 1) && (rack->r_via_fill_cw == 0)))
15101 						goto done_w_hdwr;
15102 				}
15103 				if ((rate_wanted > rack->r_ctl.crte->rate) ||
15104 				    (rate_wanted <= rack->r_ctl.crte_prev_rate)) {
15105 					if (rack_hw_rate_to_low &&
15106 					    (bw_est < rack_hw_rate_to_low)) {
15107 						/*
15108 						 * The pacing rate is too low for hardware, but
15109 						 * do allow hardware pacing to be restarted.
15110 						 */
15111 						rack_log_hdwr_pacing(rack,
15112 							     bw_est, rack->r_ctl.crte->rate, __LINE__,
15113 							     0, 5);
15114 						tcp_rel_pacing_rate(rack->r_ctl.crte, rack->rc_tp);
15115 						rack->r_ctl.crte = NULL;
15116 						rack->rack_attempt_hdwr_pace = 0;
15117 						rack->rack_hdrw_pacing = 0;
15118 						rack_set_pace_segments(rack->rc_tp, rack, __LINE__, &rate_wanted);
15119 						goto done_w_hdwr;
15120 					}
15121 					nrte = tcp_chg_pacing_rate(rack->r_ctl.crte,
15122 								   rack->rc_tp,
15123 								   rack->rc_inp->inp_route.ro_nh->nh_ifp,
15124 								   rate_wanted,
15125 								   RS_PACING_GEQ,
15126 								   &err, &rack->r_ctl.crte_prev_rate);
15127 					if (nrte == NULL) {
15128 						/* Lost the rate */
15129 						rack->rack_hdrw_pacing = 0;
15130 						rack->r_ctl.crte = NULL;
15131 						rack_log_hdwr_pacing(rack,
15132 								     rate_wanted, 0, __LINE__,
15133 								     err, 1);
15134 						rack_set_pace_segments(rack->rc_tp, rack, __LINE__, &rate_wanted);
15135 						counter_u64_add(rack_hw_pace_lost, 1);
15136 					} else if (nrte != rack->r_ctl.crte) {
15137 						rack->r_ctl.crte = nrte;
15138 						rack->r_ctl.rc_pace_max_segs = tcp_get_pacing_burst_size(tp, rate_wanted,
15139 													 segsiz, 0,
15140 													 rack->r_ctl.crte,
15141 													 NULL);
15142 						rack_log_hdwr_pacing(rack,
15143 								     rate_wanted, rack->r_ctl.crte->rate, __LINE__,
15144 								     err, 2);
15145 						rack->r_ctl.last_hw_bw_req = rate_wanted;
15146 					}
15147 				} else {
15148 					/* We just need to adjust the segment size */
15149 					rack_set_pace_segments(rack->rc_tp, rack, __LINE__, &rate_wanted);
15150 					rack_log_hdwr_pacing(rack,
15151 							     rate_wanted, rack->r_ctl.crte->rate, __LINE__,
15152 							     0, 4);
15153 					rack->r_ctl.last_hw_bw_req = rate_wanted;
15154 				}
15155 			}
15156 		}
15157 		if ((rack->r_ctl.crte != NULL) &&
15158 		    (rack->r_ctl.crte->rate == rate_wanted)) {
15159 			/*
15160 			 * We need to add a extra if the rates
15161 			 * are exactly matched. The idea is
15162 			 * we want the software to make sure the
15163 			 * queue is empty before adding more, this
15164 			 * gives us N MSS extra pace times where
15165 			 * N is our sysctl
15166 			 */
15167 			slot += (rack->r_ctl.crte->time_between * rack_hw_pace_extra_slots);
15168 		}
15169 done_w_hdwr:
15170 		if (rack_limit_time_with_srtt &&
15171 		    (rack->use_fixed_rate == 0) &&
15172 #ifdef NETFLIX_PEAKRATE
15173 		    (rack->rc_tp->t_maxpeakrate == 0) &&
15174 #endif
15175 		    (rack->rack_hdrw_pacing == 0)) {
15176 			/*
15177 			 * Sanity check, we do not allow the pacing delay
15178 			 * to be longer than the SRTT of the path. If it is
15179 			 * a slow path, then adding a packet should increase
15180 			 * the RTT and compensate for this i.e. the srtt will
15181 			 * be greater so the allowed pacing time will be greater.
15182 			 *
15183 			 * Note this restriction is not for where a peak rate
15184 			 * is set, we are doing fixed pacing or hardware pacing.
15185 			 */
15186 			if (rack->rc_tp->t_srtt)
15187 				srtt = rack->rc_tp->t_srtt;
15188 			else
15189 				srtt = RACK_INITIAL_RTO * HPTS_USEC_IN_MSEC;	/* its in ms convert */
15190 			if (srtt < (uint64_t)slot) {
15191 				rack_log_pacing_delay_calc(rack, srtt, slot, rate_wanted, bw_est, lentim, 99, __LINE__, NULL, 0);
15192 				slot = srtt;
15193 			}
15194 		}
15195 		rack_log_pacing_delay_calc(rack, len, slot, rate_wanted, bw_est, lentim, 2, __LINE__, rsm, 0);
15196 	}
15197 	if (rack->r_ctl.crte && (rack->r_ctl.crte->rs_num_enobufs > 0)) {
15198 		/*
15199 		 * If this rate is seeing enobufs when it
15200 		 * goes to send then either the nic is out
15201 		 * of gas or we are mis-estimating the time
15202 		 * somehow and not letting the queue empty
15203 		 * completely. Lets add to the pacing time.
15204 		 */
15205 		int hw_boost_delay;
15206 
15207 		hw_boost_delay = rack->r_ctl.crte->time_between * rack_enobuf_hw_boost_mult;
15208 		if (hw_boost_delay > rack_enobuf_hw_max)
15209 			hw_boost_delay = rack_enobuf_hw_max;
15210 		else if (hw_boost_delay < rack_enobuf_hw_min)
15211 			hw_boost_delay = rack_enobuf_hw_min;
15212 		slot += hw_boost_delay;
15213 	}
15214 	return (slot);
15215 }
15216 
15217 static void
15218 rack_start_gp_measurement(struct tcpcb *tp, struct tcp_rack *rack,
15219     tcp_seq startseq, uint32_t sb_offset)
15220 {
15221 	struct rack_sendmap *my_rsm = NULL;
15222 	struct rack_sendmap fe;
15223 
15224 	if (tp->t_state < TCPS_ESTABLISHED) {
15225 		/*
15226 		 * We don't start any measurements if we are
15227 		 * not at least established.
15228 		 */
15229 		return;
15230 	}
15231 	if (tp->t_state >= TCPS_FIN_WAIT_1) {
15232 		/*
15233 		 * We will get no more data into the SB
15234 		 * this means we need to have the data available
15235 		 * before we start a measurement.
15236 		 */
15237 
15238 		if (sbavail(&tptosocket(tp)->so_snd) <
15239 		    max(rc_init_window(rack),
15240 			(MIN_GP_WIN * ctf_fixed_maxseg(tp)))) {
15241 			/* Nope not enough data */
15242 			return;
15243 		}
15244 	}
15245 	tp->t_flags |= TF_GPUTINPROG;
15246 	rack->r_ctl.rc_gp_lowrtt = 0xffffffff;
15247 	rack->r_ctl.rc_gp_high_rwnd = rack->rc_tp->snd_wnd;
15248 	tp->gput_seq = startseq;
15249 	rack->app_limited_needs_set = 0;
15250 	if (rack->in_probe_rtt)
15251 		rack->measure_saw_probe_rtt = 1;
15252 	else if ((rack->measure_saw_probe_rtt) &&
15253 		 (SEQ_GEQ(tp->gput_seq, rack->r_ctl.rc_probertt_sndmax_atexit)))
15254 		rack->measure_saw_probe_rtt = 0;
15255 	if (rack->rc_gp_filled)
15256 		tp->gput_ts = tcp_tv_to_usectick(&rack->r_ctl.act_rcv_time);
15257 	else {
15258 		/* Special case initial measurement */
15259 		struct timeval tv;
15260 
15261 		tp->gput_ts = tcp_get_usecs(&tv);
15262 		rack->r_ctl.rc_gp_output_ts = rack_to_usec_ts(&tv);
15263 	}
15264 	/*
15265 	 * We take a guess out into the future,
15266 	 * if we have no measurement and no
15267 	 * initial rate, we measure the first
15268 	 * initial-windows worth of data to
15269 	 * speed up getting some GP measurement and
15270 	 * thus start pacing.
15271 	 */
15272 	if ((rack->rc_gp_filled == 0) && (rack->r_ctl.init_rate == 0)) {
15273 		rack->app_limited_needs_set = 1;
15274 		tp->gput_ack = startseq + max(rc_init_window(rack),
15275 					      (MIN_GP_WIN * ctf_fixed_maxseg(tp)));
15276 		rack_log_pacing_delay_calc(rack,
15277 					   tp->gput_seq,
15278 					   tp->gput_ack,
15279 					   0,
15280 					   tp->gput_ts,
15281 					   rack->r_ctl.rc_app_limited_cnt,
15282 					   9,
15283 					   __LINE__, NULL, 0);
15284 		return;
15285 	}
15286 	if (sb_offset) {
15287 		/*
15288 		 * We are out somewhere in the sb
15289 		 * can we use the already outstanding data?
15290 		 */
15291 		if (rack->r_ctl.rc_app_limited_cnt == 0) {
15292 			/*
15293 			 * Yes first one is good and in this case
15294 			 * the tp->gput_ts is correctly set based on
15295 			 * the last ack that arrived (no need to
15296 			 * set things up when an ack comes in).
15297 			 */
15298 			my_rsm = RB_MIN(rack_rb_tree_head, &rack->r_ctl.rc_mtree);
15299 			if ((my_rsm == NULL) ||
15300 			    (my_rsm->r_rtr_cnt != 1)) {
15301 				/* retransmission? */
15302 				goto use_latest;
15303 			}
15304 		} else {
15305 			if (rack->r_ctl.rc_first_appl == NULL) {
15306 				/*
15307 				 * If rc_first_appl is NULL
15308 				 * then the cnt should be 0.
15309 				 * This is probably an error, maybe
15310 				 * a KASSERT would be approprate.
15311 				 */
15312 				goto use_latest;
15313 			}
15314 			/*
15315 			 * If we have a marker pointer to the last one that is
15316 			 * app limited we can use that, but we need to set
15317 			 * things up so that when it gets ack'ed we record
15318 			 * the ack time (if its not already acked).
15319 			 */
15320 			rack->app_limited_needs_set = 1;
15321 			/*
15322 			 * We want to get to the rsm that is either
15323 			 * next with space i.e. over 1 MSS or the one
15324 			 * after that (after the app-limited).
15325 			 */
15326 			my_rsm = RB_NEXT(rack_rb_tree_head, &rack->r_ctl.rc_mtree,
15327 					 rack->r_ctl.rc_first_appl);
15328 			if (my_rsm) {
15329 				if ((my_rsm->r_end - my_rsm->r_start) <= ctf_fixed_maxseg(tp))
15330 					/* Have to use the next one */
15331 					my_rsm = RB_NEXT(rack_rb_tree_head, &rack->r_ctl.rc_mtree,
15332 							 my_rsm);
15333 				else {
15334 					/* Use after the first MSS of it is acked */
15335 					tp->gput_seq = my_rsm->r_start + ctf_fixed_maxseg(tp);
15336 					goto start_set;
15337 				}
15338 			}
15339 			if ((my_rsm == NULL) ||
15340 			    (my_rsm->r_rtr_cnt != 1)) {
15341 				/*
15342 				 * Either its a retransmit or
15343 				 * the last is the app-limited one.
15344 				 */
15345 				goto use_latest;
15346 			}
15347 		}
15348 		tp->gput_seq = my_rsm->r_start;
15349 start_set:
15350 		if (my_rsm->r_flags & RACK_ACKED) {
15351 			/*
15352 			 * This one has been acked use the arrival ack time
15353 			 */
15354 			tp->gput_ts = (uint32_t)my_rsm->r_ack_arrival;
15355 			rack->app_limited_needs_set = 0;
15356 		}
15357 		rack->r_ctl.rc_gp_output_ts = my_rsm->r_tim_lastsent[(my_rsm->r_rtr_cnt-1)];
15358 		tp->gput_ack = tp->gput_seq + rack_get_measure_window(tp, rack);
15359 		rack_log_pacing_delay_calc(rack,
15360 					   tp->gput_seq,
15361 					   tp->gput_ack,
15362 					   (uint64_t)my_rsm,
15363 					   tp->gput_ts,
15364 					   rack->r_ctl.rc_app_limited_cnt,
15365 					   9,
15366 					   __LINE__, NULL, 0);
15367 		return;
15368 	}
15369 
15370 use_latest:
15371 	/*
15372 	 * We don't know how long we may have been
15373 	 * idle or if this is the first-send. Lets
15374 	 * setup the flag so we will trim off
15375 	 * the first ack'd data so we get a true
15376 	 * measurement.
15377 	 */
15378 	rack->app_limited_needs_set = 1;
15379 	tp->gput_ack = startseq + rack_get_measure_window(tp, rack);
15380 	/* Find this guy so we can pull the send time */
15381 	fe.r_start = startseq;
15382 	my_rsm = RB_FIND(rack_rb_tree_head, &rack->r_ctl.rc_mtree, &fe);
15383 	if (my_rsm) {
15384 		rack->r_ctl.rc_gp_output_ts = my_rsm->r_tim_lastsent[(my_rsm->r_rtr_cnt-1)];
15385 		if (my_rsm->r_flags & RACK_ACKED) {
15386 			/*
15387 			 * Unlikely since its probably what was
15388 			 * just transmitted (but I am paranoid).
15389 			 */
15390 			tp->gput_ts = (uint32_t)my_rsm->r_ack_arrival;
15391 			rack->app_limited_needs_set = 0;
15392 		}
15393 		if (SEQ_LT(my_rsm->r_start, tp->gput_seq)) {
15394 			/* This also is unlikely */
15395 			tp->gput_seq = my_rsm->r_start;
15396 		}
15397 	} else {
15398 		/*
15399 		 * TSNH unless we have some send-map limit,
15400 		 * and even at that it should not be hitting
15401 		 * that limit (we should have stopped sending).
15402 		 */
15403 		struct timeval tv;
15404 
15405 		microuptime(&tv);
15406 		rack->r_ctl.rc_gp_output_ts = rack_to_usec_ts(&tv);
15407 	}
15408 	rack_log_pacing_delay_calc(rack,
15409 				   tp->gput_seq,
15410 				   tp->gput_ack,
15411 				   (uint64_t)my_rsm,
15412 				   tp->gput_ts,
15413 				   rack->r_ctl.rc_app_limited_cnt,
15414 				   9, __LINE__, NULL, 0);
15415 }
15416 
15417 static inline uint32_t
15418 rack_what_can_we_send(struct tcpcb *tp, struct tcp_rack *rack,  uint32_t cwnd_to_use,
15419     uint32_t avail, int32_t sb_offset)
15420 {
15421 	uint32_t len;
15422 	uint32_t sendwin;
15423 
15424 	if (tp->snd_wnd > cwnd_to_use)
15425 		sendwin = cwnd_to_use;
15426 	else
15427 		sendwin = tp->snd_wnd;
15428 	if (ctf_outstanding(tp) >= tp->snd_wnd) {
15429 		/* We never want to go over our peers rcv-window */
15430 		len = 0;
15431 	} else {
15432 		uint32_t flight;
15433 
15434 		flight = ctf_flight_size(tp, rack->r_ctl.rc_sacked);
15435 		if (flight >= sendwin) {
15436 			/*
15437 			 * We have in flight what we are allowed by cwnd (if
15438 			 * it was rwnd blocking it would have hit above out
15439 			 * >= tp->snd_wnd).
15440 			 */
15441 			return (0);
15442 		}
15443 		len = sendwin - flight;
15444 		if ((len + ctf_outstanding(tp)) > tp->snd_wnd) {
15445 			/* We would send too much (beyond the rwnd) */
15446 			len = tp->snd_wnd - ctf_outstanding(tp);
15447 		}
15448 		if ((len + sb_offset) > avail) {
15449 			/*
15450 			 * We don't have that much in the SB, how much is
15451 			 * there?
15452 			 */
15453 			len = avail - sb_offset;
15454 		}
15455 	}
15456 	return (len);
15457 }
15458 
15459 static void
15460 rack_log_fsb(struct tcp_rack *rack, struct tcpcb *tp, struct socket *so, uint32_t flags,
15461 	     unsigned ipoptlen, int32_t orig_len, int32_t len, int error,
15462 	     int rsm_is_null, int optlen, int line, uint16_t mode)
15463 {
15464 	if (tp->t_logstate != TCP_LOG_STATE_OFF) {
15465 		union tcp_log_stackspecific log;
15466 		struct timeval tv;
15467 
15468 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
15469 		log.u_bbr.inhpts = tcp_in_hpts(rack->rc_inp);
15470 		log.u_bbr.flex1 = error;
15471 		log.u_bbr.flex2 = flags;
15472 		log.u_bbr.flex3 = rsm_is_null;
15473 		log.u_bbr.flex4 = ipoptlen;
15474 		log.u_bbr.flex5 = tp->rcv_numsacks;
15475 		log.u_bbr.flex6 = rack->r_ctl.rc_agg_early;
15476 		log.u_bbr.flex7 = optlen;
15477 		log.u_bbr.flex8 = rack->r_fsb_inited;
15478 		log.u_bbr.applimited = rack->r_fast_output;
15479 		log.u_bbr.bw_inuse = rack_get_bw(rack);
15480 		log.u_bbr.pacing_gain = rack_get_output_gain(rack, NULL);
15481 		log.u_bbr.cwnd_gain = mode;
15482 		log.u_bbr.pkts_out = orig_len;
15483 		log.u_bbr.lt_epoch = len;
15484 		log.u_bbr.delivered = line;
15485 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
15486 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
15487 		tcp_log_event_(tp, NULL, &so->so_rcv, &so->so_snd, TCP_LOG_FSB, 0,
15488 			       len, &log, false, NULL, NULL, 0, &tv);
15489 	}
15490 }
15491 
15492 
15493 static struct mbuf *
15494 rack_fo_base_copym(struct mbuf *the_m, uint32_t the_off, int32_t *plen,
15495 		   struct rack_fast_send_blk *fsb,
15496 		   int32_t seglimit, int32_t segsize, int hw_tls)
15497 {
15498 #ifdef KERN_TLS
15499 	struct ktls_session *tls, *ntls;
15500 #ifdef INVARIANTS
15501 	struct mbuf *start;
15502 #endif
15503 #endif
15504 	struct mbuf *m, *n, **np, *smb;
15505 	struct mbuf *top;
15506 	int32_t off, soff;
15507 	int32_t len = *plen;
15508 	int32_t fragsize;
15509 	int32_t len_cp = 0;
15510 	uint32_t mlen, frags;
15511 
15512 	soff = off = the_off;
15513 	smb = m = the_m;
15514 	np = &top;
15515 	top = NULL;
15516 #ifdef KERN_TLS
15517 	if (hw_tls && (m->m_flags & M_EXTPG))
15518 		tls = m->m_epg_tls;
15519 	else
15520 		tls = NULL;
15521 #ifdef INVARIANTS
15522 	start = m;
15523 #endif
15524 #endif
15525 	while (len > 0) {
15526 		if (m == NULL) {
15527 			*plen = len_cp;
15528 			break;
15529 		}
15530 #ifdef KERN_TLS
15531 		if (hw_tls) {
15532 			if (m->m_flags & M_EXTPG)
15533 				ntls = m->m_epg_tls;
15534 			else
15535 				ntls = NULL;
15536 
15537 			/*
15538 			 * Avoid mixing TLS records with handshake
15539 			 * data or TLS records from different
15540 			 * sessions.
15541 			 */
15542 			if (tls != ntls) {
15543 				MPASS(m != start);
15544 				*plen = len_cp;
15545 				break;
15546 			}
15547 		}
15548 #endif
15549 		mlen = min(len, m->m_len - off);
15550 		if (seglimit) {
15551 			/*
15552 			 * For M_EXTPG mbufs, add 3 segments
15553 			 * + 1 in case we are crossing page boundaries
15554 			 * + 2 in case the TLS hdr/trailer are used
15555 			 * It is cheaper to just add the segments
15556 			 * than it is to take the cache miss to look
15557 			 * at the mbuf ext_pgs state in detail.
15558 			 */
15559 			if (m->m_flags & M_EXTPG) {
15560 				fragsize = min(segsize, PAGE_SIZE);
15561 				frags = 3;
15562 			} else {
15563 				fragsize = segsize;
15564 				frags = 0;
15565 			}
15566 
15567 			/* Break if we really can't fit anymore. */
15568 			if ((frags + 1) >= seglimit) {
15569 				*plen =	len_cp;
15570 				break;
15571 			}
15572 
15573 			/*
15574 			 * Reduce size if you can't copy the whole
15575 			 * mbuf. If we can't copy the whole mbuf, also
15576 			 * adjust len so the loop will end after this
15577 			 * mbuf.
15578 			 */
15579 			if ((frags + howmany(mlen, fragsize)) >= seglimit) {
15580 				mlen = (seglimit - frags - 1) * fragsize;
15581 				len = mlen;
15582 				*plen = len_cp + len;
15583 			}
15584 			frags += howmany(mlen, fragsize);
15585 			if (frags == 0)
15586 				frags++;
15587 			seglimit -= frags;
15588 			KASSERT(seglimit > 0,
15589 			    ("%s: seglimit went too low", __func__));
15590 		}
15591 		n = m_get(M_NOWAIT, m->m_type);
15592 		*np = n;
15593 		if (n == NULL)
15594 			goto nospace;
15595 		n->m_len = mlen;
15596 		soff += mlen;
15597 		len_cp += n->m_len;
15598 		if (m->m_flags & (M_EXT|M_EXTPG)) {
15599 			n->m_data = m->m_data + off;
15600 			mb_dupcl(n, m);
15601 		} else {
15602 			bcopy(mtod(m, caddr_t)+off, mtod(n, caddr_t),
15603 			    (u_int)n->m_len);
15604 		}
15605 		len -= n->m_len;
15606 		off = 0;
15607 		m = m->m_next;
15608 		np = &n->m_next;
15609 		if (len || (soff == smb->m_len)) {
15610 			/*
15611 			 * We have more so we move forward  or
15612 			 * we have consumed the entire mbuf and
15613 			 * len has fell to 0.
15614 			 */
15615 			soff = 0;
15616 			smb = m;
15617 		}
15618 
15619 	}
15620 	if (fsb != NULL) {
15621 		fsb->m = smb;
15622 		fsb->off = soff;
15623 		if (smb) {
15624 			/*
15625 			 * Save off the size of the mbuf. We do
15626 			 * this so that we can recognize when it
15627 			 * has been trimmed by sbcut() as acks
15628 			 * come in.
15629 			 */
15630 			fsb->o_m_len = smb->m_len;
15631 		} else {
15632 			/*
15633 			 * This is the case where the next mbuf went to NULL. This
15634 			 * means with this copy we have sent everything in the sb.
15635 			 * In theory we could clear the fast_output flag, but lets
15636 			 * not since its possible that we could get more added
15637 			 * and acks that call the extend function which would let
15638 			 * us send more.
15639 			 */
15640 			fsb->o_m_len = 0;
15641 		}
15642 	}
15643 	return (top);
15644 nospace:
15645 	if (top)
15646 		m_freem(top);
15647 	return (NULL);
15648 
15649 }
15650 
15651 /*
15652  * This is a copy of m_copym(), taking the TSO segment size/limit
15653  * constraints into account, and advancing the sndptr as it goes.
15654  */
15655 static struct mbuf *
15656 rack_fo_m_copym(struct tcp_rack *rack, int32_t *plen,
15657 		int32_t seglimit, int32_t segsize, struct mbuf **s_mb, int *s_soff)
15658 {
15659 	struct mbuf *m, *n;
15660 	int32_t soff;
15661 
15662 	soff = rack->r_ctl.fsb.off;
15663 	m = rack->r_ctl.fsb.m;
15664 	if (rack->r_ctl.fsb.o_m_len > m->m_len) {
15665 		/*
15666 		 * The mbuf had the front of it chopped off by an ack
15667 		 * we need to adjust the soff/off by that difference.
15668 		 */
15669 		uint32_t delta;
15670 
15671 		delta = rack->r_ctl.fsb.o_m_len - m->m_len;
15672 		soff -= delta;
15673 	} else if (rack->r_ctl.fsb.o_m_len < m->m_len) {
15674 		/*
15675 		 * The mbuf was expanded probably by
15676 		 * a m_compress. Just update o_m_len.
15677 		 */
15678 		rack->r_ctl.fsb.o_m_len = m->m_len;
15679 	}
15680 	KASSERT(soff >= 0, ("%s, negative off %d", __FUNCTION__, soff));
15681 	KASSERT(*plen >= 0, ("%s, negative len %d", __FUNCTION__, *plen));
15682 	KASSERT(soff < m->m_len, ("%s rack:%p len:%u m:%p m->m_len:%u < off?",
15683 				 __FUNCTION__,
15684 				 rack, *plen, m, m->m_len));
15685 	/* Save off the right location before we copy and advance */
15686 	*s_soff = soff;
15687 	*s_mb = rack->r_ctl.fsb.m;
15688 	n = rack_fo_base_copym(m, soff, plen,
15689 			       &rack->r_ctl.fsb,
15690 			       seglimit, segsize, rack->r_ctl.fsb.hw_tls);
15691 	return (n);
15692 }
15693 
15694 static int
15695 rack_fast_rsm_output(struct tcpcb *tp, struct tcp_rack *rack, struct rack_sendmap *rsm,
15696 		     uint64_t ts_val, uint32_t cts, uint32_t ms_cts, struct timeval *tv, int len, uint8_t doing_tlp)
15697 {
15698 	/*
15699 	 * Enter the fast retransmit path. We are given that a sched_pin is
15700 	 * in place (if accounting is compliled in) and the cycle count taken
15701 	 * at the entry is in the ts_val. The concept her is that the rsm
15702 	 * now holds the mbuf offsets and such so we can directly transmit
15703 	 * without a lot of overhead, the len field is already set for
15704 	 * us to prohibit us from sending too much (usually its 1MSS).
15705 	 */
15706 	struct ip *ip = NULL;
15707 	struct udphdr *udp = NULL;
15708 	struct tcphdr *th = NULL;
15709 	struct mbuf *m = NULL;
15710 	struct inpcb *inp;
15711 	uint8_t *cpto;
15712 	struct tcp_log_buffer *lgb;
15713 #ifdef TCP_ACCOUNTING
15714 	uint64_t crtsc;
15715 	int cnt_thru = 1;
15716 #endif
15717 	struct tcpopt to;
15718 	u_char opt[TCP_MAXOLEN];
15719 	uint32_t hdrlen, optlen;
15720 	int32_t slot, segsiz, max_val, tso = 0, error, ulen = 0;
15721 	uint16_t flags;
15722 	uint32_t if_hw_tsomaxsegcount = 0, startseq;
15723 	uint32_t if_hw_tsomaxsegsize;
15724 
15725 #ifdef INET6
15726 	struct ip6_hdr *ip6 = NULL;
15727 
15728 	if (rack->r_is_v6) {
15729 		ip6 = (struct ip6_hdr *)rack->r_ctl.fsb.tcp_ip_hdr;
15730 		hdrlen = sizeof(struct ip6_hdr) + sizeof(struct tcphdr);
15731 	} else
15732 #endif				/* INET6 */
15733 	{
15734 		ip = (struct ip *)rack->r_ctl.fsb.tcp_ip_hdr;
15735 		hdrlen = sizeof(struct tcpiphdr);
15736 	}
15737 	if (tp->t_port && (V_tcp_udp_tunneling_port == 0)) {
15738 		goto failed;
15739 	}
15740 	if (doing_tlp) {
15741 		/* Its a TLP add the flag, it may already be there but be sure */
15742 		rsm->r_flags |= RACK_TLP;
15743 	} else {
15744 		/* If it was a TLP it is not not on this retransmit */
15745 		rsm->r_flags &= ~RACK_TLP;
15746 	}
15747 	startseq = rsm->r_start;
15748 	segsiz = min(ctf_fixed_maxseg(tp), rack->r_ctl.rc_pace_min_segs);
15749 	inp = rack->rc_inp;
15750 	to.to_flags = 0;
15751 	flags = tcp_outflags[tp->t_state];
15752 	if (flags & (TH_SYN|TH_RST)) {
15753 		goto failed;
15754 	}
15755 	if (rsm->r_flags & RACK_HAS_FIN) {
15756 		/* We can't send a FIN here */
15757 		goto failed;
15758 	}
15759 	if (flags & TH_FIN) {
15760 		/* We never send a FIN */
15761 		flags &= ~TH_FIN;
15762 	}
15763 	if (tp->t_flags & TF_RCVD_TSTMP) {
15764 		to.to_tsval = ms_cts + tp->ts_offset;
15765 		to.to_tsecr = tp->ts_recent;
15766 		to.to_flags = TOF_TS;
15767 	}
15768 	optlen = tcp_addoptions(&to, opt);
15769 	hdrlen += optlen;
15770 	udp = rack->r_ctl.fsb.udp;
15771 	if (udp)
15772 		hdrlen += sizeof(struct udphdr);
15773 	if (rack->r_ctl.rc_pace_max_segs)
15774 		max_val = rack->r_ctl.rc_pace_max_segs;
15775 	else if (rack->rc_user_set_max_segs)
15776 		max_val = rack->rc_user_set_max_segs * segsiz;
15777 	else
15778 		max_val = len;
15779 	if ((tp->t_flags & TF_TSO) &&
15780 	    V_tcp_do_tso &&
15781 	    (len > segsiz) &&
15782 	    (tp->t_port == 0))
15783 		tso = 1;
15784 #ifdef INET6
15785 	if (MHLEN < hdrlen + max_linkhdr)
15786 		m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR);
15787 	else
15788 #endif
15789 		m = m_gethdr(M_NOWAIT, MT_DATA);
15790 	if (m == NULL)
15791 		goto failed;
15792 	m->m_data += max_linkhdr;
15793 	m->m_len = hdrlen;
15794 	th = rack->r_ctl.fsb.th;
15795 	/* Establish the len to send */
15796 	if (len > max_val)
15797 		len = max_val;
15798 	if ((tso) && (len + optlen > tp->t_maxseg)) {
15799 		uint32_t if_hw_tsomax;
15800 		int32_t max_len;
15801 
15802 		/* extract TSO information */
15803 		if_hw_tsomax = tp->t_tsomax;
15804 		if_hw_tsomaxsegcount = tp->t_tsomaxsegcount;
15805 		if_hw_tsomaxsegsize = tp->t_tsomaxsegsize;
15806 		/*
15807 		 * Check if we should limit by maximum payload
15808 		 * length:
15809 		 */
15810 		if (if_hw_tsomax != 0) {
15811 			/* compute maximum TSO length */
15812 			max_len = (if_hw_tsomax - hdrlen -
15813 				   max_linkhdr);
15814 			if (max_len <= 0) {
15815 				goto failed;
15816 			} else if (len > max_len) {
15817 				len = max_len;
15818 			}
15819 		}
15820 		if (len <= segsiz) {
15821 			/*
15822 			 * In case there are too many small fragments don't
15823 			 * use TSO:
15824 			 */
15825 			tso = 0;
15826 		}
15827 	} else {
15828 		tso = 0;
15829 	}
15830 	if ((tso == 0) && (len > segsiz))
15831 		len = segsiz;
15832 	if ((len == 0) ||
15833 	    (len <= MHLEN - hdrlen - max_linkhdr)) {
15834 		goto failed;
15835 	}
15836 	th->th_seq = htonl(rsm->r_start);
15837 	th->th_ack = htonl(tp->rcv_nxt);
15838 	/*
15839 	 * The PUSH bit should only be applied
15840 	 * if the full retransmission is made. If
15841 	 * we are sending less than this is the
15842 	 * left hand edge and should not have
15843 	 * the PUSH bit.
15844 	 */
15845 	if ((rsm->r_flags & RACK_HAD_PUSH) &&
15846 	    (len == (rsm->r_end - rsm->r_start)))
15847 		flags |= TH_PUSH;
15848 	th->th_win = htons((u_short)(rack->r_ctl.fsb.recwin >> tp->rcv_scale));
15849 	if (th->th_win == 0) {
15850 		tp->t_sndzerowin++;
15851 		tp->t_flags |= TF_RXWIN0SENT;
15852 	} else
15853 		tp->t_flags &= ~TF_RXWIN0SENT;
15854 	if (rsm->r_flags & RACK_TLP) {
15855 		/*
15856 		 * TLP should not count in retran count, but
15857 		 * in its own bin
15858 		 */
15859 		counter_u64_add(rack_tlp_retran, 1);
15860 		counter_u64_add(rack_tlp_retran_bytes, len);
15861 	} else {
15862 		tp->t_sndrexmitpack++;
15863 		KMOD_TCPSTAT_INC(tcps_sndrexmitpack);
15864 		KMOD_TCPSTAT_ADD(tcps_sndrexmitbyte, len);
15865 	}
15866 #ifdef STATS
15867 	stats_voi_update_abs_u32(tp->t_stats, VOI_TCP_RETXPB,
15868 				 len);
15869 #endif
15870 	if (rsm->m == NULL)
15871 		goto failed;
15872 	if (rsm->orig_m_len != rsm->m->m_len) {
15873 		/* Fix up the orig_m_len and possibly the mbuf offset */
15874 		rack_adjust_orig_mlen(rsm);
15875 	}
15876 	m->m_next = rack_fo_base_copym(rsm->m, rsm->soff, &len, NULL, if_hw_tsomaxsegcount, if_hw_tsomaxsegsize, rsm->r_hw_tls);
15877 	if (len <= segsiz) {
15878 		/*
15879 		 * Must have ran out of mbufs for the copy
15880 		 * shorten it to no longer need tso. Lets
15881 		 * not put on sendalot since we are low on
15882 		 * mbufs.
15883 		 */
15884 		tso = 0;
15885 	}
15886 	if ((m->m_next == NULL) || (len <= 0)){
15887 		goto failed;
15888 	}
15889 	if (udp) {
15890 		if (rack->r_is_v6)
15891 			ulen = hdrlen + len - sizeof(struct ip6_hdr);
15892 		else
15893 			ulen = hdrlen + len - sizeof(struct ip);
15894 		udp->uh_ulen = htons(ulen);
15895 	}
15896 	m->m_pkthdr.rcvif = (struct ifnet *)0;
15897 	if (TCPS_HAVERCVDSYN(tp->t_state) &&
15898 	    (tp->t_flags2 & (TF2_ECN_PERMIT | TF2_ACE_PERMIT))) {
15899 		int ect = tcp_ecn_output_established(tp, &flags, len, true);
15900 		if ((tp->t_state == TCPS_SYN_RECEIVED) &&
15901 		    (tp->t_flags2 & TF2_ECN_SND_ECE))
15902 		    tp->t_flags2 &= ~TF2_ECN_SND_ECE;
15903 #ifdef INET6
15904 		if (rack->r_is_v6) {
15905 		    ip6->ip6_flow &= ~htonl(IPTOS_ECN_MASK << 20);
15906 		    ip6->ip6_flow |= htonl(ect << 20);
15907 		}
15908 		else
15909 #endif
15910 		{
15911 		    ip->ip_tos &= ~IPTOS_ECN_MASK;
15912 		    ip->ip_tos |= ect;
15913 		}
15914 	}
15915 	tcp_set_flags(th, flags);
15916 	m->m_pkthdr.len = hdrlen + len;	/* in6_cksum() need this */
15917 #ifdef INET6
15918 	if (rack->r_is_v6) {
15919 		if (tp->t_port) {
15920 			m->m_pkthdr.csum_flags = CSUM_UDP_IPV6;
15921 			m->m_pkthdr.csum_data = offsetof(struct udphdr, uh_sum);
15922 			udp->uh_sum = in6_cksum_pseudo(ip6, ulen, IPPROTO_UDP, 0);
15923 			th->th_sum = htons(0);
15924 			UDPSTAT_INC(udps_opackets);
15925 		} else {
15926 			m->m_pkthdr.csum_flags = CSUM_TCP_IPV6;
15927 			m->m_pkthdr.csum_data = offsetof(struct tcphdr, th_sum);
15928 			th->th_sum = in6_cksum_pseudo(ip6,
15929 						      sizeof(struct tcphdr) + optlen + len, IPPROTO_TCP,
15930 						      0);
15931 		}
15932 	}
15933 #endif
15934 #if defined(INET6) && defined(INET)
15935 	else
15936 #endif
15937 #ifdef INET
15938 	{
15939 		if (tp->t_port) {
15940 			m->m_pkthdr.csum_flags = CSUM_UDP;
15941 			m->m_pkthdr.csum_data = offsetof(struct udphdr, uh_sum);
15942 			udp->uh_sum = in_pseudo(ip->ip_src.s_addr,
15943 						ip->ip_dst.s_addr, htons(ulen + IPPROTO_UDP));
15944 			th->th_sum = htons(0);
15945 			UDPSTAT_INC(udps_opackets);
15946 		} else {
15947 			m->m_pkthdr.csum_flags = CSUM_TCP;
15948 			m->m_pkthdr.csum_data = offsetof(struct tcphdr, th_sum);
15949 			th->th_sum = in_pseudo(ip->ip_src.s_addr,
15950 					       ip->ip_dst.s_addr, htons(sizeof(struct tcphdr) +
15951 									IPPROTO_TCP + len + optlen));
15952 		}
15953 		/* IP version must be set here for ipv4/ipv6 checking later */
15954 		KASSERT(ip->ip_v == IPVERSION,
15955 			("%s: IP version incorrect: %d", __func__, ip->ip_v));
15956 	}
15957 #endif
15958 	if (tso) {
15959 		KASSERT(len > tp->t_maxseg - optlen,
15960 			("%s: len <= tso_segsz tp:%p", __func__, tp));
15961 		m->m_pkthdr.csum_flags |= CSUM_TSO;
15962 		m->m_pkthdr.tso_segsz = tp->t_maxseg - optlen;
15963 	}
15964 #ifdef INET6
15965 	if (rack->r_is_v6) {
15966 		ip6->ip6_hlim = rack->r_ctl.fsb.hoplimit;
15967 		ip6->ip6_plen = htons(m->m_pkthdr.len - sizeof(*ip6));
15968 		if (V_path_mtu_discovery && tp->t_maxseg > V_tcp_minmss)
15969 			tp->t_flags2 |= TF2_PLPMTU_PMTUD;
15970 		else
15971 			tp->t_flags2 &= ~TF2_PLPMTU_PMTUD;
15972 	}
15973 #endif
15974 #if defined(INET) && defined(INET6)
15975 	else
15976 #endif
15977 #ifdef INET
15978 	{
15979 		ip->ip_len = htons(m->m_pkthdr.len);
15980 		ip->ip_ttl = rack->r_ctl.fsb.hoplimit;
15981 		if (V_path_mtu_discovery && tp->t_maxseg > V_tcp_minmss) {
15982 			tp->t_flags2 |= TF2_PLPMTU_PMTUD;
15983 			if (tp->t_port == 0 || len < V_tcp_minmss) {
15984 				ip->ip_off |= htons(IP_DF);
15985 			}
15986 		} else {
15987 			tp->t_flags2 &= ~TF2_PLPMTU_PMTUD;
15988 		}
15989 	}
15990 #endif
15991 	/* Time to copy in our header */
15992 	cpto = mtod(m, uint8_t *);
15993 	memcpy(cpto, rack->r_ctl.fsb.tcp_ip_hdr, rack->r_ctl.fsb.tcp_ip_hdr_len);
15994 	th = (struct tcphdr *)(cpto + ((uint8_t *)rack->r_ctl.fsb.th - rack->r_ctl.fsb.tcp_ip_hdr));
15995 	if (optlen) {
15996 		bcopy(opt, th + 1, optlen);
15997 		th->th_off = (sizeof(struct tcphdr) + optlen) >> 2;
15998 	} else {
15999 		th->th_off = sizeof(struct tcphdr) >> 2;
16000 	}
16001 	if (tp->t_logstate != TCP_LOG_STATE_OFF) {
16002 		union tcp_log_stackspecific log;
16003 
16004 		if (rsm->r_flags & RACK_RWND_COLLAPSED) {
16005 			rack_log_collapse(rack, rsm->r_start, rsm->r_end, 0, __LINE__, 5, rsm->r_flags, rsm);
16006 			counter_u64_add(rack_collapsed_win_rxt, 1);
16007 			counter_u64_add(rack_collapsed_win_rxt_bytes, (rsm->r_end - rsm->r_start));
16008 		}
16009 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
16010 		log.u_bbr.inhpts = tcp_in_hpts(rack->rc_inp);
16011 		if (rack->rack_no_prr)
16012 			log.u_bbr.flex1 = 0;
16013 		else
16014 			log.u_bbr.flex1 = rack->r_ctl.rc_prr_sndcnt;
16015 		log.u_bbr.flex2 = rack->r_ctl.rc_pace_min_segs;
16016 		log.u_bbr.flex3 = rack->r_ctl.rc_pace_max_segs;
16017 		log.u_bbr.flex4 = max_val;
16018 		log.u_bbr.flex5 = 0;
16019 		/* Save off the early/late values */
16020 		log.u_bbr.flex6 = rack->r_ctl.rc_agg_early;
16021 		log.u_bbr.applimited = rack->r_ctl.rc_agg_delayed;
16022 		log.u_bbr.bw_inuse = rack_get_bw(rack);
16023 		if (doing_tlp == 0)
16024 			log.u_bbr.flex8 = 1;
16025 		else
16026 			log.u_bbr.flex8 = 2;
16027 		log.u_bbr.pacing_gain = rack_get_output_gain(rack, NULL);
16028 		log.u_bbr.flex7 = 55;
16029 		log.u_bbr.pkts_out = tp->t_maxseg;
16030 		log.u_bbr.timeStamp = cts;
16031 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
16032 		log.u_bbr.lt_epoch = rack->r_ctl.cwnd_to_use;
16033 		log.u_bbr.delivered = 0;
16034 		lgb = tcp_log_event_(tp, th, NULL, NULL, TCP_LOG_OUT, ERRNO_UNK,
16035 				     len, &log, false, NULL, NULL, 0, tv);
16036 	} else
16037 		lgb = NULL;
16038 #ifdef INET6
16039 	if (rack->r_is_v6) {
16040 		error = ip6_output(m, NULL,
16041 				   &inp->inp_route6,
16042 				   0, NULL, NULL, inp);
16043 	}
16044 #endif
16045 #if defined(INET) && defined(INET6)
16046 	else
16047 #endif
16048 #ifdef INET
16049 	{
16050 		error = ip_output(m, NULL,
16051 				  &inp->inp_route,
16052 				  0, 0, inp);
16053 	}
16054 #endif
16055 	m = NULL;
16056 	if (lgb) {
16057 		lgb->tlb_errno = error;
16058 		lgb = NULL;
16059 	}
16060 	if (error) {
16061 		goto failed;
16062 	}
16063 	rack_log_output(tp, &to, len, rsm->r_start, flags, error, rack_to_usec_ts(tv),
16064 			rsm, RACK_SENT_FP, rsm->m, rsm->soff, rsm->r_hw_tls);
16065 	if (doing_tlp && (rack->fast_rsm_hack == 0)) {
16066 		rack->rc_tlp_in_progress = 1;
16067 		rack->r_ctl.rc_tlp_cnt_out++;
16068 	}
16069 	if (error == 0) {
16070 		tcp_account_for_send(tp, len, 1, doing_tlp, rsm->r_hw_tls);
16071 		if (doing_tlp) {
16072 			rack->rc_last_sent_tlp_past_cumack = 0;
16073 			rack->rc_last_sent_tlp_seq_valid = 1;
16074 			rack->r_ctl.last_sent_tlp_seq = rsm->r_start;
16075 			rack->r_ctl.last_sent_tlp_len = rsm->r_end - rsm->r_start;
16076 		}
16077 	}
16078 	tp->t_flags &= ~(TF_ACKNOW | TF_DELACK);
16079 	rack->forced_ack = 0;	/* If we send something zap the FA flag */
16080 	if (IN_FASTRECOVERY(tp->t_flags) && rsm)
16081 		rack->r_ctl.retran_during_recovery += len;
16082 	{
16083 		int idx;
16084 
16085 		idx = (len / segsiz) + 3;
16086 		if (idx >= TCP_MSS_ACCT_ATIMER)
16087 			counter_u64_add(rack_out_size[(TCP_MSS_ACCT_ATIMER-1)], 1);
16088 		else
16089 			counter_u64_add(rack_out_size[idx], 1);
16090 	}
16091 	if (tp->t_rtttime == 0) {
16092 		tp->t_rtttime = ticks;
16093 		tp->t_rtseq = startseq;
16094 		KMOD_TCPSTAT_INC(tcps_segstimed);
16095 	}
16096 	counter_u64_add(rack_fto_rsm_send, 1);
16097 	if (error && (error == ENOBUFS)) {
16098 		if (rack->r_ctl.crte != NULL) {
16099 			rack_trace_point(rack, RACK_TP_HWENOBUF);
16100 		} else
16101 			rack_trace_point(rack, RACK_TP_ENOBUF);
16102 		slot = ((1 + rack->rc_enobuf) * HPTS_USEC_IN_MSEC);
16103 		if (rack->rc_enobuf < 0x7f)
16104 			rack->rc_enobuf++;
16105 		if (slot < (10 * HPTS_USEC_IN_MSEC))
16106 			slot = 10 * HPTS_USEC_IN_MSEC;
16107 	} else
16108 		slot = rack_get_pacing_delay(rack, tp, len, NULL, segsiz);
16109 	if ((slot == 0) ||
16110 	    (rack->rc_always_pace == 0) ||
16111 	    (rack->r_rr_config == 1)) {
16112 		/*
16113 		 * We have no pacing set or we
16114 		 * are using old-style rack or
16115 		 * we are overridden to use the old 1ms pacing.
16116 		 */
16117 		slot = rack->r_ctl.rc_min_to;
16118 	}
16119 	rack_start_hpts_timer(rack, tp, cts, slot, len, 0);
16120 #ifdef TCP_ACCOUNTING
16121 	crtsc = get_cyclecount();
16122 	if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
16123 		tp->tcp_cnt_counters[SND_OUT_DATA] += cnt_thru;
16124 	}
16125 	counter_u64_add(tcp_cnt_counters[SND_OUT_DATA], cnt_thru);
16126 	if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
16127 		tp->tcp_proc_time[SND_OUT_DATA] += (crtsc - ts_val);
16128 	}
16129 	counter_u64_add(tcp_proc_time[SND_OUT_DATA], (crtsc - ts_val));
16130 	if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
16131 		tp->tcp_cnt_counters[CNT_OF_MSS_OUT] += ((len + segsiz - 1) / segsiz);
16132 	}
16133 	counter_u64_add(tcp_cnt_counters[CNT_OF_MSS_OUT], ((len + segsiz - 1) / segsiz));
16134 	sched_unpin();
16135 #endif
16136 	return (0);
16137 failed:
16138 	if (m)
16139 		m_free(m);
16140 	return (-1);
16141 }
16142 
16143 static void
16144 rack_sndbuf_autoscale(struct tcp_rack *rack)
16145 {
16146 	/*
16147 	 * Automatic sizing of send socket buffer.  Often the send buffer
16148 	 * size is not optimally adjusted to the actual network conditions
16149 	 * at hand (delay bandwidth product).  Setting the buffer size too
16150 	 * small limits throughput on links with high bandwidth and high
16151 	 * delay (eg. trans-continental/oceanic links).  Setting the
16152 	 * buffer size too big consumes too much real kernel memory,
16153 	 * especially with many connections on busy servers.
16154 	 *
16155 	 * The criteria to step up the send buffer one notch are:
16156 	 *  1. receive window of remote host is larger than send buffer
16157 	 *     (with a fudge factor of 5/4th);
16158 	 *  2. send buffer is filled to 7/8th with data (so we actually
16159 	 *     have data to make use of it);
16160 	 *  3. send buffer fill has not hit maximal automatic size;
16161 	 *  4. our send window (slow start and cogestion controlled) is
16162 	 *     larger than sent but unacknowledged data in send buffer.
16163 	 *
16164 	 * Note that the rack version moves things much faster since
16165 	 * we want to avoid hitting cache lines in the rack_fast_output()
16166 	 * path so this is called much less often and thus moves
16167 	 * the SB forward by a percentage.
16168 	 */
16169 	struct socket *so;
16170 	struct tcpcb *tp;
16171 	uint32_t sendwin, scaleup;
16172 
16173 	tp = rack->rc_tp;
16174 	so = rack->rc_inp->inp_socket;
16175 	sendwin = min(rack->r_ctl.cwnd_to_use, tp->snd_wnd);
16176 	if (V_tcp_do_autosndbuf && so->so_snd.sb_flags & SB_AUTOSIZE) {
16177 		if ((tp->snd_wnd / 4 * 5) >= so->so_snd.sb_hiwat &&
16178 		    sbused(&so->so_snd) >=
16179 		    (so->so_snd.sb_hiwat / 8 * 7) &&
16180 		    sbused(&so->so_snd) < V_tcp_autosndbuf_max &&
16181 		    sendwin >= (sbused(&so->so_snd) -
16182 		    (tp->snd_nxt - tp->snd_una))) {
16183 			if (rack_autosndbuf_inc)
16184 				scaleup = (rack_autosndbuf_inc * so->so_snd.sb_hiwat) / 100;
16185 			else
16186 				scaleup = V_tcp_autosndbuf_inc;
16187 			if (scaleup < V_tcp_autosndbuf_inc)
16188 				scaleup = V_tcp_autosndbuf_inc;
16189 			scaleup += so->so_snd.sb_hiwat;
16190 			if (scaleup > V_tcp_autosndbuf_max)
16191 				scaleup = V_tcp_autosndbuf_max;
16192 			if (!sbreserve_locked(so, SO_SND, scaleup, curthread))
16193 				so->so_snd.sb_flags &= ~SB_AUTOSIZE;
16194 		}
16195 	}
16196 }
16197 
16198 static int
16199 rack_fast_output(struct tcpcb *tp, struct tcp_rack *rack, uint64_t ts_val,
16200 		 uint32_t cts, uint32_t ms_cts, struct timeval *tv, long tot_len, int *send_err)
16201 {
16202 	/*
16203 	 * Enter to do fast output. We are given that the sched_pin is
16204 	 * in place (if accounting is compiled in) and the cycle count taken
16205 	 * at entry is in place in ts_val. The idea here is that
16206 	 * we know how many more bytes needs to be sent (presumably either
16207 	 * during pacing or to fill the cwnd and that was greater than
16208 	 * the max-burst). We have how much to send and all the info we
16209 	 * need to just send.
16210 	 */
16211 	struct ip *ip = NULL;
16212 	struct udphdr *udp = NULL;
16213 	struct tcphdr *th = NULL;
16214 	struct mbuf *m, *s_mb;
16215 	struct inpcb *inp;
16216 	uint8_t *cpto;
16217 	struct tcp_log_buffer *lgb;
16218 #ifdef TCP_ACCOUNTING
16219 	uint64_t crtsc;
16220 #endif
16221 	struct tcpopt to;
16222 	u_char opt[TCP_MAXOLEN];
16223 	uint32_t hdrlen, optlen;
16224 #ifdef TCP_ACCOUNTING
16225 	int cnt_thru = 1;
16226 #endif
16227 	int32_t slot, segsiz, len, max_val, tso = 0, sb_offset, error, ulen = 0;
16228 	uint16_t flags;
16229 	uint32_t s_soff;
16230 	uint32_t if_hw_tsomaxsegcount = 0, startseq;
16231 	uint32_t if_hw_tsomaxsegsize;
16232 	uint16_t add_flag = RACK_SENT_FP;
16233 #ifdef INET6
16234 	struct ip6_hdr *ip6 = NULL;
16235 
16236 	if (rack->r_is_v6) {
16237 		ip6 = (struct ip6_hdr *)rack->r_ctl.fsb.tcp_ip_hdr;
16238 		hdrlen = sizeof(struct ip6_hdr) + sizeof(struct tcphdr);
16239 	} else
16240 #endif				/* INET6 */
16241 	{
16242 		ip = (struct ip *)rack->r_ctl.fsb.tcp_ip_hdr;
16243 		hdrlen = sizeof(struct tcpiphdr);
16244 	}
16245 	if (tp->t_port && (V_tcp_udp_tunneling_port == 0)) {
16246 		m = NULL;
16247 		goto failed;
16248 	}
16249 	startseq = tp->snd_max;
16250 	segsiz = min(ctf_fixed_maxseg(tp), rack->r_ctl.rc_pace_min_segs);
16251 	inp = rack->rc_inp;
16252 	len = rack->r_ctl.fsb.left_to_send;
16253 	to.to_flags = 0;
16254 	flags = rack->r_ctl.fsb.tcp_flags;
16255 	if (tp->t_flags & TF_RCVD_TSTMP) {
16256 		to.to_tsval = ms_cts + tp->ts_offset;
16257 		to.to_tsecr = tp->ts_recent;
16258 		to.to_flags = TOF_TS;
16259 	}
16260 	optlen = tcp_addoptions(&to, opt);
16261 	hdrlen += optlen;
16262 	udp = rack->r_ctl.fsb.udp;
16263 	if (udp)
16264 		hdrlen += sizeof(struct udphdr);
16265 	if (rack->r_ctl.rc_pace_max_segs)
16266 		max_val = rack->r_ctl.rc_pace_max_segs;
16267 	else if (rack->rc_user_set_max_segs)
16268 		max_val = rack->rc_user_set_max_segs * segsiz;
16269 	else
16270 		max_val = len;
16271 	if ((tp->t_flags & TF_TSO) &&
16272 	    V_tcp_do_tso &&
16273 	    (len > segsiz) &&
16274 	    (tp->t_port == 0))
16275 		tso = 1;
16276 again:
16277 #ifdef INET6
16278 	if (MHLEN < hdrlen + max_linkhdr)
16279 		m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR);
16280 	else
16281 #endif
16282 		m = m_gethdr(M_NOWAIT, MT_DATA);
16283 	if (m == NULL)
16284 		goto failed;
16285 	m->m_data += max_linkhdr;
16286 	m->m_len = hdrlen;
16287 	th = rack->r_ctl.fsb.th;
16288 	/* Establish the len to send */
16289 	if (len > max_val)
16290 		len = max_val;
16291 	if ((tso) && (len + optlen > tp->t_maxseg)) {
16292 		uint32_t if_hw_tsomax;
16293 		int32_t max_len;
16294 
16295 		/* extract TSO information */
16296 		if_hw_tsomax = tp->t_tsomax;
16297 		if_hw_tsomaxsegcount = tp->t_tsomaxsegcount;
16298 		if_hw_tsomaxsegsize = tp->t_tsomaxsegsize;
16299 		/*
16300 		 * Check if we should limit by maximum payload
16301 		 * length:
16302 		 */
16303 		if (if_hw_tsomax != 0) {
16304 			/* compute maximum TSO length */
16305 			max_len = (if_hw_tsomax - hdrlen -
16306 				   max_linkhdr);
16307 			if (max_len <= 0) {
16308 				goto failed;
16309 			} else if (len > max_len) {
16310 				len = max_len;
16311 			}
16312 		}
16313 		if (len <= segsiz) {
16314 			/*
16315 			 * In case there are too many small fragments don't
16316 			 * use TSO:
16317 			 */
16318 			tso = 0;
16319 		}
16320 	} else {
16321 		tso = 0;
16322 	}
16323 	if ((tso == 0) && (len > segsiz))
16324 		len = segsiz;
16325 	if ((len == 0) ||
16326 	    (len <= MHLEN - hdrlen - max_linkhdr)) {
16327 		goto failed;
16328 	}
16329 	sb_offset = tp->snd_max - tp->snd_una;
16330 	th->th_seq = htonl(tp->snd_max);
16331 	th->th_ack = htonl(tp->rcv_nxt);
16332 	th->th_win = htons((u_short)(rack->r_ctl.fsb.recwin >> tp->rcv_scale));
16333 	if (th->th_win == 0) {
16334 		tp->t_sndzerowin++;
16335 		tp->t_flags |= TF_RXWIN0SENT;
16336 	} else
16337 		tp->t_flags &= ~TF_RXWIN0SENT;
16338 	tp->snd_up = tp->snd_una;	/* drag it along, its deprecated */
16339 	KMOD_TCPSTAT_INC(tcps_sndpack);
16340 	KMOD_TCPSTAT_ADD(tcps_sndbyte, len);
16341 #ifdef STATS
16342 	stats_voi_update_abs_u64(tp->t_stats, VOI_TCP_TXPB,
16343 				 len);
16344 #endif
16345 	if (rack->r_ctl.fsb.m == NULL)
16346 		goto failed;
16347 
16348 	/* s_mb and s_soff are saved for rack_log_output */
16349 	m->m_next = rack_fo_m_copym(rack, &len, if_hw_tsomaxsegcount, if_hw_tsomaxsegsize,
16350 				    &s_mb, &s_soff);
16351 	if (len <= segsiz) {
16352 		/*
16353 		 * Must have ran out of mbufs for the copy
16354 		 * shorten it to no longer need tso. Lets
16355 		 * not put on sendalot since we are low on
16356 		 * mbufs.
16357 		 */
16358 		tso = 0;
16359 	}
16360 	if (rack->r_ctl.fsb.rfo_apply_push &&
16361 	    (len == rack->r_ctl.fsb.left_to_send)) {
16362 		flags |= TH_PUSH;
16363 		add_flag |= RACK_HAD_PUSH;
16364 	}
16365 	if ((m->m_next == NULL) || (len <= 0)){
16366 		goto failed;
16367 	}
16368 	if (udp) {
16369 		if (rack->r_is_v6)
16370 			ulen = hdrlen + len - sizeof(struct ip6_hdr);
16371 		else
16372 			ulen = hdrlen + len - sizeof(struct ip);
16373 		udp->uh_ulen = htons(ulen);
16374 	}
16375 	m->m_pkthdr.rcvif = (struct ifnet *)0;
16376 	if (TCPS_HAVERCVDSYN(tp->t_state) &&
16377 	    (tp->t_flags2 & (TF2_ECN_PERMIT | TF2_ACE_PERMIT))) {
16378 		int ect = tcp_ecn_output_established(tp, &flags, len, false);
16379 		if ((tp->t_state == TCPS_SYN_RECEIVED) &&
16380 		    (tp->t_flags2 & TF2_ECN_SND_ECE))
16381 			tp->t_flags2 &= ~TF2_ECN_SND_ECE;
16382 #ifdef INET6
16383 		if (rack->r_is_v6) {
16384 			ip6->ip6_flow &= ~htonl(IPTOS_ECN_MASK << 20);
16385 			ip6->ip6_flow |= htonl(ect << 20);
16386 		}
16387 		else
16388 #endif
16389 		{
16390 			ip->ip_tos &= ~IPTOS_ECN_MASK;
16391 			ip->ip_tos |= ect;
16392 		}
16393 	}
16394 	tcp_set_flags(th, flags);
16395 	m->m_pkthdr.len = hdrlen + len;	/* in6_cksum() need this */
16396 #ifdef INET6
16397 	if (rack->r_is_v6) {
16398 		if (tp->t_port) {
16399 			m->m_pkthdr.csum_flags = CSUM_UDP_IPV6;
16400 			m->m_pkthdr.csum_data = offsetof(struct udphdr, uh_sum);
16401 			udp->uh_sum = in6_cksum_pseudo(ip6, ulen, IPPROTO_UDP, 0);
16402 			th->th_sum = htons(0);
16403 			UDPSTAT_INC(udps_opackets);
16404 		} else {
16405 			m->m_pkthdr.csum_flags = CSUM_TCP_IPV6;
16406 			m->m_pkthdr.csum_data = offsetof(struct tcphdr, th_sum);
16407 			th->th_sum = in6_cksum_pseudo(ip6,
16408 						      sizeof(struct tcphdr) + optlen + len, IPPROTO_TCP,
16409 						      0);
16410 		}
16411 	}
16412 #endif
16413 #if defined(INET6) && defined(INET)
16414 	else
16415 #endif
16416 #ifdef INET
16417 	{
16418 		if (tp->t_port) {
16419 			m->m_pkthdr.csum_flags = CSUM_UDP;
16420 			m->m_pkthdr.csum_data = offsetof(struct udphdr, uh_sum);
16421 			udp->uh_sum = in_pseudo(ip->ip_src.s_addr,
16422 						ip->ip_dst.s_addr, htons(ulen + IPPROTO_UDP));
16423 			th->th_sum = htons(0);
16424 			UDPSTAT_INC(udps_opackets);
16425 		} else {
16426 			m->m_pkthdr.csum_flags = CSUM_TCP;
16427 			m->m_pkthdr.csum_data = offsetof(struct tcphdr, th_sum);
16428 			th->th_sum = in_pseudo(ip->ip_src.s_addr,
16429 					       ip->ip_dst.s_addr, htons(sizeof(struct tcphdr) +
16430 									IPPROTO_TCP + len + optlen));
16431 		}
16432 		/* IP version must be set here for ipv4/ipv6 checking later */
16433 		KASSERT(ip->ip_v == IPVERSION,
16434 			("%s: IP version incorrect: %d", __func__, ip->ip_v));
16435 	}
16436 #endif
16437 	if (tso) {
16438 		KASSERT(len > tp->t_maxseg - optlen,
16439 			("%s: len <= tso_segsz tp:%p", __func__, tp));
16440 		m->m_pkthdr.csum_flags |= CSUM_TSO;
16441 		m->m_pkthdr.tso_segsz = tp->t_maxseg - optlen;
16442 	}
16443 #ifdef INET6
16444 	if (rack->r_is_v6) {
16445 		ip6->ip6_hlim = rack->r_ctl.fsb.hoplimit;
16446 		ip6->ip6_plen = htons(m->m_pkthdr.len - sizeof(*ip6));
16447 		if (V_path_mtu_discovery && tp->t_maxseg > V_tcp_minmss)
16448 			tp->t_flags2 |= TF2_PLPMTU_PMTUD;
16449 		else
16450 			tp->t_flags2 &= ~TF2_PLPMTU_PMTUD;
16451 	}
16452 #endif
16453 #if defined(INET) && defined(INET6)
16454 	else
16455 #endif
16456 #ifdef INET
16457 	{
16458 		ip->ip_len = htons(m->m_pkthdr.len);
16459 		ip->ip_ttl = rack->r_ctl.fsb.hoplimit;
16460 		if (V_path_mtu_discovery && tp->t_maxseg > V_tcp_minmss) {
16461 			tp->t_flags2 |= TF2_PLPMTU_PMTUD;
16462 			if (tp->t_port == 0 || len < V_tcp_minmss) {
16463 				ip->ip_off |= htons(IP_DF);
16464 			}
16465 		} else {
16466 			tp->t_flags2 &= ~TF2_PLPMTU_PMTUD;
16467 		}
16468 	}
16469 #endif
16470 	/* Time to copy in our header */
16471 	cpto = mtod(m, uint8_t *);
16472 	memcpy(cpto, rack->r_ctl.fsb.tcp_ip_hdr, rack->r_ctl.fsb.tcp_ip_hdr_len);
16473 	th = (struct tcphdr *)(cpto + ((uint8_t *)rack->r_ctl.fsb.th - rack->r_ctl.fsb.tcp_ip_hdr));
16474 	if (optlen) {
16475 		bcopy(opt, th + 1, optlen);
16476 		th->th_off = (sizeof(struct tcphdr) + optlen) >> 2;
16477 	} else {
16478 		th->th_off = sizeof(struct tcphdr) >> 2;
16479 	}
16480 	if (tp->t_logstate != TCP_LOG_STATE_OFF) {
16481 		union tcp_log_stackspecific log;
16482 
16483 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
16484 		log.u_bbr.inhpts = tcp_in_hpts(rack->rc_inp);
16485 		if (rack->rack_no_prr)
16486 			log.u_bbr.flex1 = 0;
16487 		else
16488 			log.u_bbr.flex1 = rack->r_ctl.rc_prr_sndcnt;
16489 		log.u_bbr.flex2 = rack->r_ctl.rc_pace_min_segs;
16490 		log.u_bbr.flex3 = rack->r_ctl.rc_pace_max_segs;
16491 		log.u_bbr.flex4 = max_val;
16492 		log.u_bbr.flex5 = 0;
16493 		/* Save off the early/late values */
16494 		log.u_bbr.flex6 = rack->r_ctl.rc_agg_early;
16495 		log.u_bbr.applimited = rack->r_ctl.rc_agg_delayed;
16496 		log.u_bbr.bw_inuse = rack_get_bw(rack);
16497 		log.u_bbr.flex8 = 0;
16498 		log.u_bbr.pacing_gain = rack_get_output_gain(rack, NULL);
16499 		log.u_bbr.flex7 = 44;
16500 		log.u_bbr.pkts_out = tp->t_maxseg;
16501 		log.u_bbr.timeStamp = cts;
16502 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
16503 		log.u_bbr.lt_epoch = rack->r_ctl.cwnd_to_use;
16504 		log.u_bbr.delivered = 0;
16505 		lgb = tcp_log_event_(tp, th, NULL, NULL, TCP_LOG_OUT, ERRNO_UNK,
16506 				     len, &log, false, NULL, NULL, 0, tv);
16507 	} else
16508 		lgb = NULL;
16509 #ifdef INET6
16510 	if (rack->r_is_v6) {
16511 		error = ip6_output(m, NULL,
16512 				   &inp->inp_route6,
16513 				   0, NULL, NULL, inp);
16514 	}
16515 #endif
16516 #if defined(INET) && defined(INET6)
16517 	else
16518 #endif
16519 #ifdef INET
16520 	{
16521 		error = ip_output(m, NULL,
16522 				  &inp->inp_route,
16523 				  0, 0, inp);
16524 	}
16525 #endif
16526 	if (lgb) {
16527 		lgb->tlb_errno = error;
16528 		lgb = NULL;
16529 	}
16530 	if (error) {
16531 		*send_err = error;
16532 		m = NULL;
16533 		goto failed;
16534 	}
16535 	rack_log_output(tp, &to, len, tp->snd_max, flags, error, rack_to_usec_ts(tv),
16536 			NULL, add_flag, s_mb, s_soff, rack->r_ctl.fsb.hw_tls);
16537 	m = NULL;
16538 	if (tp->snd_una == tp->snd_max) {
16539 		rack->r_ctl.rc_tlp_rxt_last_time = cts;
16540 		rack_log_progress_event(rack, tp, ticks, PROGRESS_START, __LINE__);
16541 		tp->t_acktime = ticks;
16542 	}
16543 	if (error == 0)
16544 		tcp_account_for_send(tp, len, 0, 0, rack->r_ctl.fsb.hw_tls);
16545 
16546 	rack->forced_ack = 0;	/* If we send something zap the FA flag */
16547 	tot_len += len;
16548 	if ((tp->t_flags & TF_GPUTINPROG) == 0)
16549 		rack_start_gp_measurement(tp, rack, tp->snd_max, sb_offset);
16550 	tp->snd_max += len;
16551 	tp->snd_nxt = tp->snd_max;
16552 	{
16553 		int idx;
16554 
16555 		idx = (len / segsiz) + 3;
16556 		if (idx >= TCP_MSS_ACCT_ATIMER)
16557 			counter_u64_add(rack_out_size[(TCP_MSS_ACCT_ATIMER-1)], 1);
16558 		else
16559 			counter_u64_add(rack_out_size[idx], 1);
16560 	}
16561 	if (len <= rack->r_ctl.fsb.left_to_send)
16562 		rack->r_ctl.fsb.left_to_send -= len;
16563 	else
16564 		rack->r_ctl.fsb.left_to_send = 0;
16565 	if (rack->r_ctl.fsb.left_to_send < segsiz) {
16566 		rack->r_fast_output = 0;
16567 		rack->r_ctl.fsb.left_to_send = 0;
16568 		/* At the end of fast_output scale up the sb */
16569 		SOCKBUF_LOCK(&rack->rc_inp->inp_socket->so_snd);
16570 		rack_sndbuf_autoscale(rack);
16571 		SOCKBUF_UNLOCK(&rack->rc_inp->inp_socket->so_snd);
16572 	}
16573 	if (tp->t_rtttime == 0) {
16574 		tp->t_rtttime = ticks;
16575 		tp->t_rtseq = startseq;
16576 		KMOD_TCPSTAT_INC(tcps_segstimed);
16577 	}
16578 	if ((rack->r_ctl.fsb.left_to_send >= segsiz) &&
16579 	    (max_val > len) &&
16580 	    (tso == 0)) {
16581 		max_val -= len;
16582 		len = segsiz;
16583 		th = rack->r_ctl.fsb.th;
16584 #ifdef TCP_ACCOUNTING
16585 		cnt_thru++;
16586 #endif
16587 		goto again;
16588 	}
16589 	tp->t_flags &= ~(TF_ACKNOW | TF_DELACK);
16590 	counter_u64_add(rack_fto_send, 1);
16591 	slot = rack_get_pacing_delay(rack, tp, tot_len, NULL, segsiz);
16592 	rack_start_hpts_timer(rack, tp, cts, slot, tot_len, 0);
16593 #ifdef TCP_ACCOUNTING
16594 	crtsc = get_cyclecount();
16595 	if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
16596 		tp->tcp_cnt_counters[SND_OUT_DATA] += cnt_thru;
16597 	}
16598 	counter_u64_add(tcp_cnt_counters[SND_OUT_DATA], cnt_thru);
16599 	if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
16600 		tp->tcp_proc_time[SND_OUT_DATA] += (crtsc - ts_val);
16601 	}
16602 	counter_u64_add(tcp_proc_time[SND_OUT_DATA], (crtsc - ts_val));
16603 	if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
16604 		tp->tcp_cnt_counters[CNT_OF_MSS_OUT] += ((tot_len + segsiz - 1) / segsiz);
16605 	}
16606 	counter_u64_add(tcp_cnt_counters[CNT_OF_MSS_OUT], ((tot_len + segsiz - 1) / segsiz));
16607 	sched_unpin();
16608 #endif
16609 	return (0);
16610 failed:
16611 	if (m)
16612 		m_free(m);
16613 	rack->r_fast_output = 0;
16614 	return (-1);
16615 }
16616 
16617 static struct rack_sendmap *
16618 rack_check_collapsed(struct tcp_rack *rack, uint32_t cts)
16619 {
16620 	struct rack_sendmap *rsm = NULL;
16621 	struct rack_sendmap fe;
16622 	int thresh;
16623 
16624 restart:
16625 	fe.r_start = rack->r_ctl.last_collapse_point;
16626 	rsm = RB_FIND(rack_rb_tree_head, &rack->r_ctl.rc_mtree, &fe);
16627 	if ((rsm == NULL) || ((rsm->r_flags & RACK_RWND_COLLAPSED) == 0)) {
16628 		/* Nothing, strange turn off validity  */
16629 		rack->r_collapse_point_valid = 0;
16630 		return (NULL);
16631 	}
16632 	/* Can we send it yet? */
16633 	if (rsm->r_end > (rack->rc_tp->snd_una + rack->rc_tp->snd_wnd)) {
16634 		/*
16635 		 * Receiver window has not grown enough for
16636 		 * the segment to be put on the wire.
16637 		 */
16638 		return (NULL);
16639 	}
16640 	if (rsm->r_flags & RACK_ACKED) {
16641 		/*
16642 		 * It has been sacked, lets move to the
16643 		 * next one if possible.
16644 		 */
16645 		rack->r_ctl.last_collapse_point = rsm->r_end;
16646 		/* Are we done? */
16647 		if (SEQ_GEQ(rack->r_ctl.last_collapse_point,
16648 			    rack->r_ctl.high_collapse_point)) {
16649 			rack->r_collapse_point_valid = 0;
16650 			return (NULL);
16651 		}
16652 		goto restart;
16653 	}
16654 	/* Now has it been long enough ? */
16655 	thresh = rack_calc_thresh_rack(rack, rack_grab_rtt(rack->rc_tp, rack), cts);
16656 	if ((cts - ((uint32_t)rsm->r_tim_lastsent[(rsm->r_rtr_cnt-1)])) > thresh) {
16657 		rack_log_collapse(rack, rsm->r_start,
16658 				  (cts - ((uint32_t)rsm->r_tim_lastsent[(rsm->r_rtr_cnt-1)])),
16659 				  thresh, __LINE__, 6, rsm->r_flags, rsm);
16660 		return (rsm);
16661 	}
16662 	/* Not enough time */
16663 	rack_log_collapse(rack, rsm->r_start,
16664 			  (cts - ((uint32_t)rsm->r_tim_lastsent[(rsm->r_rtr_cnt-1)])),
16665 			  thresh, __LINE__, 7, rsm->r_flags, rsm);
16666 	return (NULL);
16667 }
16668 
16669 static int
16670 rack_output(struct tcpcb *tp)
16671 {
16672 	struct socket *so;
16673 	uint32_t recwin;
16674 	uint32_t sb_offset, s_moff = 0;
16675 	int32_t len, error = 0;
16676 	uint16_t flags;
16677 	struct mbuf *m, *s_mb = NULL;
16678 	struct mbuf *mb;
16679 	uint32_t if_hw_tsomaxsegcount = 0;
16680 	uint32_t if_hw_tsomaxsegsize;
16681 	int32_t segsiz, minseg;
16682 	long tot_len_this_send = 0;
16683 #ifdef INET
16684 	struct ip *ip = NULL;
16685 #endif
16686 	struct udphdr *udp = NULL;
16687 	struct tcp_rack *rack;
16688 	struct tcphdr *th;
16689 	uint8_t pass = 0;
16690 	uint8_t mark = 0;
16691 	uint8_t wanted_cookie = 0;
16692 	u_char opt[TCP_MAXOLEN];
16693 	unsigned ipoptlen, optlen, hdrlen, ulen=0;
16694 	uint32_t rack_seq;
16695 
16696 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
16697 	unsigned ipsec_optlen = 0;
16698 
16699 #endif
16700 	int32_t idle, sendalot;
16701 	int32_t sub_from_prr = 0;
16702 	volatile int32_t sack_rxmit;
16703 	struct rack_sendmap *rsm = NULL;
16704 	int32_t tso, mtu;
16705 	struct tcpopt to;
16706 	int32_t slot = 0;
16707 	int32_t sup_rack = 0;
16708 	uint32_t cts, ms_cts, delayed, early;
16709 	uint16_t add_flag = RACK_SENT_SP;
16710 	/* The doing_tlp flag will be set by the actual rack_timeout_tlp() */
16711 	uint8_t hpts_calling,  doing_tlp = 0;
16712 	uint32_t cwnd_to_use, pace_max_seg;
16713 	int32_t do_a_prefetch = 0;
16714 	int32_t prefetch_rsm = 0;
16715 	int32_t orig_len = 0;
16716 	struct timeval tv;
16717 	int32_t prefetch_so_done = 0;
16718 	struct tcp_log_buffer *lgb;
16719 	struct inpcb *inp = tptoinpcb(tp);
16720 	struct sockbuf *sb;
16721 	uint64_t ts_val = 0;
16722 #ifdef TCP_ACCOUNTING
16723 	uint64_t crtsc;
16724 #endif
16725 #ifdef INET6
16726 	struct ip6_hdr *ip6 = NULL;
16727 	int32_t isipv6;
16728 #endif
16729 	bool hw_tls = false;
16730 
16731 	NET_EPOCH_ASSERT();
16732 	INP_WLOCK_ASSERT(inp);
16733 
16734 	/* setup and take the cache hits here */
16735 	rack = (struct tcp_rack *)tp->t_fb_ptr;
16736 #ifdef TCP_ACCOUNTING
16737 	sched_pin();
16738 	ts_val = get_cyclecount();
16739 #endif
16740 	hpts_calling = inp->inp_hpts_calls;
16741 #ifdef TCP_OFFLOAD
16742 	if (tp->t_flags & TF_TOE) {
16743 #ifdef TCP_ACCOUNTING
16744 		sched_unpin();
16745 #endif
16746 		return (tcp_offload_output(tp));
16747 	}
16748 #endif
16749 	/*
16750 	 * For TFO connections in SYN_RECEIVED, only allow the initial
16751 	 * SYN|ACK and those sent by the retransmit timer.
16752 	 */
16753 	if (IS_FASTOPEN(tp->t_flags) &&
16754 	    (tp->t_state == TCPS_SYN_RECEIVED) &&
16755 	    SEQ_GT(tp->snd_max, tp->snd_una) &&    /* initial SYN|ACK sent */
16756 	    (rack->r_ctl.rc_resend == NULL)) {         /* not a retransmit */
16757 #ifdef TCP_ACCOUNTING
16758 		sched_unpin();
16759 #endif
16760 		return (0);
16761 	}
16762 #ifdef INET6
16763 	if (rack->r_state) {
16764 		/* Use the cache line loaded if possible */
16765 		isipv6 = rack->r_is_v6;
16766 	} else {
16767 		isipv6 = (rack->rc_inp->inp_vflag & INP_IPV6) != 0;
16768 	}
16769 #endif
16770 	early = 0;
16771 	cts = tcp_get_usecs(&tv);
16772 	ms_cts = tcp_tv_to_mssectick(&tv);
16773 	if (((rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT) == 0) &&
16774 	    tcp_in_hpts(rack->rc_inp)) {
16775 		/*
16776 		 * We are on the hpts for some timer but not hptsi output.
16777 		 * Remove from the hpts unconditionally.
16778 		 */
16779 		rack_timer_cancel(tp, rack, cts, __LINE__);
16780 	}
16781 	/* Are we pacing and late? */
16782 	if ((rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT) &&
16783 	    TSTMP_GEQ(cts, rack->r_ctl.rc_last_output_to)) {
16784 		/* We are delayed */
16785 		delayed = cts - rack->r_ctl.rc_last_output_to;
16786 	} else {
16787 		delayed = 0;
16788 	}
16789 	/* Do the timers, which may override the pacer */
16790 	if (rack->r_ctl.rc_hpts_flags & PACE_TMR_MASK) {
16791 		int retval;
16792 
16793 		retval = rack_process_timers(tp, rack, cts, hpts_calling,
16794 		    &doing_tlp);
16795 		if (retval != 0) {
16796 			counter_u64_add(rack_out_size[TCP_MSS_ACCT_ATIMER], 1);
16797 #ifdef TCP_ACCOUNTING
16798 			sched_unpin();
16799 #endif
16800 			/*
16801 			 * If timers want tcp_drop(), then pass error out,
16802 			 * otherwise suppress it.
16803 			 */
16804 			return (retval < 0 ? retval : 0);
16805 		}
16806 	}
16807 	if (rack->rc_in_persist) {
16808 		if (tcp_in_hpts(rack->rc_inp) == 0) {
16809 			/* Timer is not running */
16810 			rack_start_hpts_timer(rack, tp, cts, 0, 0, 0);
16811 		}
16812 #ifdef TCP_ACCOUNTING
16813 		sched_unpin();
16814 #endif
16815 		return (0);
16816 	}
16817 	if ((rack->rc_ack_required == 1) &&
16818 	    (rack->r_timer_override == 0)){
16819 		/* A timeout occurred and no ack has arrived */
16820 		if (tcp_in_hpts(rack->rc_inp) == 0) {
16821 			/* Timer is not running */
16822 			rack_start_hpts_timer(rack, tp, cts, 0, 0, 0);
16823 		}
16824 #ifdef TCP_ACCOUNTING
16825 		sched_unpin();
16826 #endif
16827 		return (0);
16828 	}
16829 	if ((rack->r_timer_override) ||
16830 	    (rack->rc_ack_can_sendout_data) ||
16831 	    (delayed) ||
16832 	    (tp->t_state < TCPS_ESTABLISHED)) {
16833 		rack->rc_ack_can_sendout_data = 0;
16834 		if (tcp_in_hpts(rack->rc_inp))
16835 			tcp_hpts_remove(rack->rc_inp);
16836 	} else if (tcp_in_hpts(rack->rc_inp)) {
16837 		/*
16838 		 * On the hpts you can't pass even if ACKNOW is on, we will
16839 		 * when the hpts fires.
16840 		 */
16841 #ifdef TCP_ACCOUNTING
16842 		crtsc = get_cyclecount();
16843 		if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
16844 			tp->tcp_proc_time[SND_BLOCKED] += (crtsc - ts_val);
16845 		}
16846 		counter_u64_add(tcp_proc_time[SND_BLOCKED], (crtsc - ts_val));
16847 		if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
16848 			tp->tcp_cnt_counters[SND_BLOCKED]++;
16849 		}
16850 		counter_u64_add(tcp_cnt_counters[SND_BLOCKED], 1);
16851 		sched_unpin();
16852 #endif
16853 		counter_u64_add(rack_out_size[TCP_MSS_ACCT_INPACE], 1);
16854 		return (0);
16855 	}
16856 	rack->rc_inp->inp_hpts_calls = 0;
16857 	/* Finish out both pacing early and late accounting */
16858 	if ((rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT) &&
16859 	    TSTMP_GT(rack->r_ctl.rc_last_output_to, cts)) {
16860 		early = rack->r_ctl.rc_last_output_to - cts;
16861 	} else
16862 		early = 0;
16863 	if (delayed) {
16864 		rack->r_ctl.rc_agg_delayed += delayed;
16865 		rack->r_late = 1;
16866 	} else if (early) {
16867 		rack->r_ctl.rc_agg_early += early;
16868 		rack->r_early = 1;
16869 	}
16870 	/* Now that early/late accounting is done turn off the flag */
16871 	rack->r_ctl.rc_hpts_flags &= ~PACE_PKT_OUTPUT;
16872 	rack->r_wanted_output = 0;
16873 	rack->r_timer_override = 0;
16874 	if ((tp->t_state != rack->r_state) &&
16875 	    TCPS_HAVEESTABLISHED(tp->t_state)) {
16876 		rack_set_state(tp, rack);
16877 	}
16878 	if ((rack->r_fast_output) &&
16879 	    (doing_tlp == 0) &&
16880 	    (tp->rcv_numsacks == 0)) {
16881 		int ret;
16882 
16883 		error = 0;
16884 		ret = rack_fast_output(tp, rack, ts_val, cts, ms_cts, &tv, tot_len_this_send, &error);
16885 		if (ret >= 0)
16886 			return(ret);
16887 		else if (error) {
16888 			inp = rack->rc_inp;
16889 			so = inp->inp_socket;
16890 			sb = &so->so_snd;
16891 			goto nomore;
16892 		}
16893 	}
16894 	inp = rack->rc_inp;
16895 	/*
16896 	 * For TFO connections in SYN_SENT or SYN_RECEIVED,
16897 	 * only allow the initial SYN or SYN|ACK and those sent
16898 	 * by the retransmit timer.
16899 	 */
16900 	if (IS_FASTOPEN(tp->t_flags) &&
16901 	    ((tp->t_state == TCPS_SYN_RECEIVED) ||
16902 	     (tp->t_state == TCPS_SYN_SENT)) &&
16903 	    SEQ_GT(tp->snd_max, tp->snd_una) && /* initial SYN or SYN|ACK sent */
16904 	    (tp->t_rxtshift == 0)) {              /* not a retransmit */
16905 		cwnd_to_use = rack->r_ctl.cwnd_to_use = tp->snd_cwnd;
16906 		so = inp->inp_socket;
16907 		sb = &so->so_snd;
16908 		goto just_return_nolock;
16909 	}
16910 	/*
16911 	 * Determine length of data that should be transmitted, and flags
16912 	 * that will be used. If there is some data or critical controls
16913 	 * (SYN, RST) to send, then transmit; otherwise, investigate
16914 	 * further.
16915 	 */
16916 	idle = (tp->t_flags & TF_LASTIDLE) || (tp->snd_max == tp->snd_una);
16917 	if (tp->t_idle_reduce) {
16918 		if (idle && (TICKS_2_USEC(ticks - tp->t_rcvtime) >= tp->t_rxtcur))
16919 			rack_cc_after_idle(rack, tp);
16920 	}
16921 	tp->t_flags &= ~TF_LASTIDLE;
16922 	if (idle) {
16923 		if (tp->t_flags & TF_MORETOCOME) {
16924 			tp->t_flags |= TF_LASTIDLE;
16925 			idle = 0;
16926 		}
16927 	}
16928 	if ((tp->snd_una == tp->snd_max) &&
16929 	    rack->r_ctl.rc_went_idle_time &&
16930 	    TSTMP_GT(cts, rack->r_ctl.rc_went_idle_time)) {
16931 		idle = cts - rack->r_ctl.rc_went_idle_time;
16932 		if (idle > rack_min_probertt_hold) {
16933 			/* Count as a probe rtt */
16934 			if (rack->in_probe_rtt == 0) {
16935 				rack->r_ctl.rc_lower_rtt_us_cts = cts;
16936 				rack->r_ctl.rc_time_probertt_entered = rack->r_ctl.rc_lower_rtt_us_cts;
16937 				rack->r_ctl.rc_time_probertt_starts = rack->r_ctl.rc_lower_rtt_us_cts;
16938 				rack->r_ctl.rc_time_of_last_probertt = rack->r_ctl.rc_lower_rtt_us_cts;
16939 			} else {
16940 				rack_exit_probertt(rack, cts);
16941 			}
16942 		}
16943 		idle = 0;
16944 	}
16945 	if (rack_use_fsb && (rack->r_fsb_inited == 0) && (rack->r_state != TCPS_CLOSED))
16946 		rack_init_fsb_block(tp, rack);
16947 again:
16948 	/*
16949 	 * If we've recently taken a timeout, snd_max will be greater than
16950 	 * snd_nxt.  There may be SACK information that allows us to avoid
16951 	 * resending already delivered data.  Adjust snd_nxt accordingly.
16952 	 */
16953 	sendalot = 0;
16954 	cts = tcp_get_usecs(&tv);
16955 	ms_cts = tcp_tv_to_mssectick(&tv);
16956 	tso = 0;
16957 	mtu = 0;
16958 	segsiz = min(ctf_fixed_maxseg(tp), rack->r_ctl.rc_pace_min_segs);
16959 	minseg = segsiz;
16960 	if (rack->r_ctl.rc_pace_max_segs == 0)
16961 		pace_max_seg = rack->rc_user_set_max_segs * segsiz;
16962 	else
16963 		pace_max_seg = rack->r_ctl.rc_pace_max_segs;
16964 	sb_offset = tp->snd_max - tp->snd_una;
16965 	cwnd_to_use = rack->r_ctl.cwnd_to_use = tp->snd_cwnd;
16966 	flags = tcp_outflags[tp->t_state];
16967 	while (rack->rc_free_cnt < rack_free_cache) {
16968 		rsm = rack_alloc(rack);
16969 		if (rsm == NULL) {
16970 			if (inp->inp_hpts_calls)
16971 				/* Retry in a ms */
16972 				slot = (1 * HPTS_USEC_IN_MSEC);
16973 			so = inp->inp_socket;
16974 			sb = &so->so_snd;
16975 			goto just_return_nolock;
16976 		}
16977 		TAILQ_INSERT_TAIL(&rack->r_ctl.rc_free, rsm, r_tnext);
16978 		rack->rc_free_cnt++;
16979 		rsm = NULL;
16980 	}
16981 	if (inp->inp_hpts_calls)
16982 		inp->inp_hpts_calls = 0;
16983 	sack_rxmit = 0;
16984 	len = 0;
16985 	rsm = NULL;
16986 	if (flags & TH_RST) {
16987 		SOCKBUF_LOCK(&inp->inp_socket->so_snd);
16988 		so = inp->inp_socket;
16989 		sb = &so->so_snd;
16990 		goto send;
16991 	}
16992 	if (rack->r_ctl.rc_resend) {
16993 		/* Retransmit timer */
16994 		rsm = rack->r_ctl.rc_resend;
16995 		rack->r_ctl.rc_resend = NULL;
16996 		len = rsm->r_end - rsm->r_start;
16997 		sack_rxmit = 1;
16998 		sendalot = 0;
16999 		KASSERT(SEQ_LEQ(tp->snd_una, rsm->r_start),
17000 			("%s:%d: r.start:%u < SND.UNA:%u; tp:%p, rack:%p, rsm:%p",
17001 			 __func__, __LINE__,
17002 			 rsm->r_start, tp->snd_una, tp, rack, rsm));
17003 		sb_offset = rsm->r_start - tp->snd_una;
17004 		if (len >= segsiz)
17005 			len = segsiz;
17006 	} else if (rack->r_collapse_point_valid &&
17007 		   ((rsm = rack_check_collapsed(rack, cts)) != NULL)) {
17008 		/*
17009 		 * If an RSM is returned then enough time has passed
17010 		 * for us to retransmit it. Move up the collapse point,
17011 		 * since this rsm has its chance to retransmit now.
17012 		 */
17013 		rack_trace_point(rack, RACK_TP_COLLAPSED_RXT);
17014 		rack->r_ctl.last_collapse_point = rsm->r_end;
17015 		/* Are we done? */
17016 		if (SEQ_GEQ(rack->r_ctl.last_collapse_point,
17017 			    rack->r_ctl.high_collapse_point))
17018 			rack->r_collapse_point_valid = 0;
17019 		sack_rxmit = 1;
17020 		/* We are not doing a TLP */
17021 		doing_tlp = 0;
17022 		len = rsm->r_end - rsm->r_start;
17023 		sb_offset = rsm->r_start - tp->snd_una;
17024 		sendalot = 0;
17025 		if ((rack->full_size_rxt == 0) &&
17026 		    (rack->shape_rxt_to_pacing_min == 0) &&
17027 		    (len >= segsiz))
17028 			len = segsiz;
17029 	} else if ((rsm = tcp_rack_output(tp, rack, cts)) != NULL) {
17030 		/* We have a retransmit that takes precedence */
17031 		if ((!IN_FASTRECOVERY(tp->t_flags)) &&
17032 		    ((rsm->r_flags & RACK_MUST_RXT) == 0) &&
17033 		    ((tp->t_flags & TF_WASFRECOVERY) == 0)) {
17034 			/* Enter recovery if not induced by a time-out */
17035 			rack_cong_signal(tp, CC_NDUPACK, tp->snd_una, __LINE__);
17036 		}
17037 #ifdef INVARIANTS
17038 		if (SEQ_LT(rsm->r_start, tp->snd_una)) {
17039 			panic("Huh, tp:%p rack:%p rsm:%p start:%u < snd_una:%u\n",
17040 			      tp, rack, rsm, rsm->r_start, tp->snd_una);
17041 		}
17042 #endif
17043 		len = rsm->r_end - rsm->r_start;
17044 		KASSERT(SEQ_LEQ(tp->snd_una, rsm->r_start),
17045 			("%s:%d: r.start:%u < SND.UNA:%u; tp:%p, rack:%p, rsm:%p",
17046 			 __func__, __LINE__,
17047 			 rsm->r_start, tp->snd_una, tp, rack, rsm));
17048 		sb_offset = rsm->r_start - tp->snd_una;
17049 		sendalot = 0;
17050 		if (len >= segsiz)
17051 			len = segsiz;
17052 		if (len > 0) {
17053 			sack_rxmit = 1;
17054 			KMOD_TCPSTAT_INC(tcps_sack_rexmits);
17055 			KMOD_TCPSTAT_ADD(tcps_sack_rexmit_bytes,
17056 			    min(len, segsiz));
17057 		}
17058 	} else if (rack->r_ctl.rc_tlpsend) {
17059 		/* Tail loss probe */
17060 		long cwin;
17061 		long tlen;
17062 
17063 		/*
17064 		 * Check if we can do a TLP with a RACK'd packet
17065 		 * this can happen if we are not doing the rack
17066 		 * cheat and we skipped to a TLP and it
17067 		 * went off.
17068 		 */
17069 		rsm = rack->r_ctl.rc_tlpsend;
17070 		/* We are doing a TLP make sure the flag is preent */
17071 		rsm->r_flags |= RACK_TLP;
17072 		rack->r_ctl.rc_tlpsend = NULL;
17073 		sack_rxmit = 1;
17074 		tlen = rsm->r_end - rsm->r_start;
17075 		if (tlen > segsiz)
17076 			tlen = segsiz;
17077 		KASSERT(SEQ_LEQ(tp->snd_una, rsm->r_start),
17078 			("%s:%d: r.start:%u < SND.UNA:%u; tp:%p, rack:%p, rsm:%p",
17079 			 __func__, __LINE__,
17080 			 rsm->r_start, tp->snd_una, tp, rack, rsm));
17081 		sb_offset = rsm->r_start - tp->snd_una;
17082 		cwin = min(tp->snd_wnd, tlen);
17083 		len = cwin;
17084 	}
17085 	if (rack->r_must_retran &&
17086 	    (doing_tlp == 0) &&
17087 	    (SEQ_GT(tp->snd_max, tp->snd_una)) &&
17088 	    (rsm == NULL)) {
17089 		/*
17090 		 * There are two different ways that we
17091 		 * can get into this block:
17092 		 * a) This is a non-sack connection, we had a time-out
17093 		 *    and thus r_must_retran was set and everything
17094 		 *    left outstanding as been marked for retransmit.
17095 		 * b) The MTU of the path shrank, so that everything
17096 		 *    was marked to be retransmitted with the smaller
17097 		 *    mtu and r_must_retran was set.
17098 		 *
17099 		 * This means that we expect the sendmap (outstanding)
17100 		 * to all be marked must. We can use the tmap to
17101 		 * look at them.
17102 		 *
17103 		 */
17104 		int sendwin, flight;
17105 
17106 		sendwin = min(tp->snd_wnd, tp->snd_cwnd);
17107 		flight = ctf_flight_size(tp, rack->r_ctl.rc_out_at_rto);
17108 		if (flight >= sendwin) {
17109 			/*
17110 			 * We can't send yet.
17111 			 */
17112 			so = inp->inp_socket;
17113 			sb = &so->so_snd;
17114 			goto just_return_nolock;
17115 		}
17116 		/*
17117 		 * This is the case a/b mentioned above. All
17118 		 * outstanding/not-acked should be marked.
17119 		 * We can use the tmap to find them.
17120 		 */
17121 		rsm = TAILQ_FIRST(&rack->r_ctl.rc_tmap);
17122 		if (rsm == NULL) {
17123 			/* TSNH */
17124 			rack->r_must_retran = 0;
17125 			rack->r_ctl.rc_out_at_rto = 0;
17126 			so = inp->inp_socket;
17127 			sb = &so->so_snd;
17128 			goto just_return_nolock;
17129 		}
17130 		if ((rsm->r_flags & RACK_MUST_RXT) == 0) {
17131 			/*
17132 			 * The first one does not have the flag, did we collapse
17133 			 * further up in our list?
17134 			 */
17135 			rack->r_must_retran = 0;
17136 			rack->r_ctl.rc_out_at_rto = 0;
17137 			rsm = NULL;
17138 			sack_rxmit = 0;
17139 		} else {
17140 			sack_rxmit = 1;
17141 			len = rsm->r_end - rsm->r_start;
17142 			sb_offset = rsm->r_start - tp->snd_una;
17143 			sendalot = 0;
17144 			if ((rack->full_size_rxt == 0) &&
17145 			    (rack->shape_rxt_to_pacing_min == 0) &&
17146 			    (len >= segsiz))
17147 				len = segsiz;
17148 			/*
17149 			 * Delay removing the flag RACK_MUST_RXT so
17150 			 * that the fastpath for retransmit will
17151 			 * work with this rsm.
17152 			 */
17153 		}
17154 	}
17155 	/*
17156 	 * Enforce a connection sendmap count limit if set
17157 	 * as long as we are not retransmiting.
17158 	 */
17159 	if ((rsm == NULL) &&
17160 	    (rack->do_detection == 0) &&
17161 	    (V_tcp_map_entries_limit > 0) &&
17162 	    (rack->r_ctl.rc_num_maps_alloced >= V_tcp_map_entries_limit)) {
17163 		counter_u64_add(rack_to_alloc_limited, 1);
17164 		if (!rack->alloc_limit_reported) {
17165 			rack->alloc_limit_reported = 1;
17166 			counter_u64_add(rack_alloc_limited_conns, 1);
17167 		}
17168 		so = inp->inp_socket;
17169 		sb = &so->so_snd;
17170 		goto just_return_nolock;
17171 	}
17172 	if (rsm && (rsm->r_flags & RACK_HAS_FIN)) {
17173 		/* we are retransmitting the fin */
17174 		len--;
17175 		if (len) {
17176 			/*
17177 			 * When retransmitting data do *not* include the
17178 			 * FIN. This could happen from a TLP probe.
17179 			 */
17180 			flags &= ~TH_FIN;
17181 		}
17182 	}
17183 	if (rsm && rack->r_fsb_inited && rack_use_rsm_rfo &&
17184 	    ((rsm->r_flags & RACK_HAS_FIN) == 0)) {
17185 		int ret;
17186 
17187 		ret = rack_fast_rsm_output(tp, rack, rsm, ts_val, cts, ms_cts, &tv, len, doing_tlp);
17188 		if (ret == 0)
17189 			return (0);
17190 	}
17191 	so = inp->inp_socket;
17192 	sb = &so->so_snd;
17193 	if (do_a_prefetch == 0) {
17194 		kern_prefetch(sb, &do_a_prefetch);
17195 		do_a_prefetch = 1;
17196 	}
17197 #ifdef NETFLIX_SHARED_CWND
17198 	if ((tp->t_flags2 & TF2_TCP_SCWND_ALLOWED) &&
17199 	    rack->rack_enable_scwnd) {
17200 		/* We are doing cwnd sharing */
17201 		if (rack->gp_ready &&
17202 		    (rack->rack_attempted_scwnd == 0) &&
17203 		    (rack->r_ctl.rc_scw == NULL) &&
17204 		    tp->t_lib) {
17205 			/* The pcbid is in, lets make an attempt */
17206 			counter_u64_add(rack_try_scwnd, 1);
17207 			rack->rack_attempted_scwnd = 1;
17208 			rack->r_ctl.rc_scw = tcp_shared_cwnd_alloc(tp,
17209 								   &rack->r_ctl.rc_scw_index,
17210 								   segsiz);
17211 		}
17212 		if (rack->r_ctl.rc_scw &&
17213 		    (rack->rack_scwnd_is_idle == 1) &&
17214 		    sbavail(&so->so_snd)) {
17215 			/* we are no longer out of data */
17216 			tcp_shared_cwnd_active(rack->r_ctl.rc_scw, rack->r_ctl.rc_scw_index);
17217 			rack->rack_scwnd_is_idle = 0;
17218 		}
17219 		if (rack->r_ctl.rc_scw) {
17220 			/* First lets update and get the cwnd */
17221 			rack->r_ctl.cwnd_to_use = cwnd_to_use = tcp_shared_cwnd_update(rack->r_ctl.rc_scw,
17222 								    rack->r_ctl.rc_scw_index,
17223 								    tp->snd_cwnd, tp->snd_wnd, segsiz);
17224 		}
17225 	}
17226 #endif
17227 	/*
17228 	 * Get standard flags, and add SYN or FIN if requested by 'hidden'
17229 	 * state flags.
17230 	 */
17231 	if (tp->t_flags & TF_NEEDFIN)
17232 		flags |= TH_FIN;
17233 	if (tp->t_flags & TF_NEEDSYN)
17234 		flags |= TH_SYN;
17235 	if ((sack_rxmit == 0) && (prefetch_rsm == 0)) {
17236 		void *end_rsm;
17237 		end_rsm = TAILQ_LAST_FAST(&rack->r_ctl.rc_tmap, rack_sendmap, r_tnext);
17238 		if (end_rsm)
17239 			kern_prefetch(end_rsm, &prefetch_rsm);
17240 		prefetch_rsm = 1;
17241 	}
17242 	SOCKBUF_LOCK(sb);
17243 	/*
17244 	 * If snd_nxt == snd_max and we have transmitted a FIN, the
17245 	 * sb_offset will be > 0 even if so_snd.sb_cc is 0, resulting in a
17246 	 * negative length.  This can also occur when TCP opens up its
17247 	 * congestion window while receiving additional duplicate acks after
17248 	 * fast-retransmit because TCP will reset snd_nxt to snd_max after
17249 	 * the fast-retransmit.
17250 	 *
17251 	 * In the normal retransmit-FIN-only case, however, snd_nxt will be
17252 	 * set to snd_una, the sb_offset will be 0, and the length may wind
17253 	 * up 0.
17254 	 *
17255 	 * If sack_rxmit is true we are retransmitting from the scoreboard
17256 	 * in which case len is already set.
17257 	 */
17258 	if ((sack_rxmit == 0) &&
17259 	    (TCPS_HAVEESTABLISHED(tp->t_state) || IS_FASTOPEN(tp->t_flags))) {
17260 		uint32_t avail;
17261 
17262 		avail = sbavail(sb);
17263 		if (SEQ_GT(tp->snd_nxt, tp->snd_una) && avail)
17264 			sb_offset = tp->snd_nxt - tp->snd_una;
17265 		else
17266 			sb_offset = 0;
17267 		if ((IN_FASTRECOVERY(tp->t_flags) == 0) || rack->rack_no_prr) {
17268 			if (rack->r_ctl.rc_tlp_new_data) {
17269 				/* TLP is forcing out new data */
17270 				if (rack->r_ctl.rc_tlp_new_data > (uint32_t) (avail - sb_offset)) {
17271 					rack->r_ctl.rc_tlp_new_data = (uint32_t) (avail - sb_offset);
17272 				}
17273 				if ((rack->r_ctl.rc_tlp_new_data + sb_offset) > tp->snd_wnd) {
17274 					if (tp->snd_wnd > sb_offset)
17275 						len = tp->snd_wnd - sb_offset;
17276 					else
17277 						len = 0;
17278 				} else {
17279 					len = rack->r_ctl.rc_tlp_new_data;
17280 				}
17281 				rack->r_ctl.rc_tlp_new_data = 0;
17282 			}  else {
17283 				len = rack_what_can_we_send(tp, rack, cwnd_to_use, avail, sb_offset);
17284 			}
17285 			if ((rack->r_ctl.crte == NULL) && IN_FASTRECOVERY(tp->t_flags) && (len > segsiz)) {
17286 				/*
17287 				 * For prr=off, we need to send only 1 MSS
17288 				 * at a time. We do this because another sack could
17289 				 * be arriving that causes us to send retransmits and
17290 				 * we don't want to be on a long pace due to a larger send
17291 				 * that keeps us from sending out the retransmit.
17292 				 */
17293 				len = segsiz;
17294 			}
17295 		} else {
17296 			uint32_t outstanding;
17297 			/*
17298 			 * We are inside of a Fast recovery episode, this
17299 			 * is caused by a SACK or 3 dup acks. At this point
17300 			 * we have sent all the retransmissions and we rely
17301 			 * on PRR to dictate what we will send in the form of
17302 			 * new data.
17303 			 */
17304 
17305 			outstanding = tp->snd_max - tp->snd_una;
17306 			if ((rack->r_ctl.rc_prr_sndcnt + outstanding) > tp->snd_wnd) {
17307 				if (tp->snd_wnd > outstanding) {
17308 					len = tp->snd_wnd - outstanding;
17309 					/* Check to see if we have the data */
17310 					if ((sb_offset + len) > avail) {
17311 						/* It does not all fit */
17312 						if (avail > sb_offset)
17313 							len = avail - sb_offset;
17314 						else
17315 							len = 0;
17316 					}
17317 				} else {
17318 					len = 0;
17319 				}
17320 			} else if (avail > sb_offset) {
17321 				len = avail - sb_offset;
17322 			} else {
17323 				len = 0;
17324 			}
17325 			if (len > 0) {
17326 				if (len > rack->r_ctl.rc_prr_sndcnt) {
17327 					len = rack->r_ctl.rc_prr_sndcnt;
17328 				}
17329 				if (len > 0) {
17330 					sub_from_prr = 1;
17331 				}
17332 			}
17333 			if (len > segsiz) {
17334 				/*
17335 				 * We should never send more than a MSS when
17336 				 * retransmitting or sending new data in prr
17337 				 * mode unless the override flag is on. Most
17338 				 * likely the PRR algorithm is not going to
17339 				 * let us send a lot as well :-)
17340 				 */
17341 				if (rack->r_ctl.rc_prr_sendalot == 0) {
17342 					len = segsiz;
17343 				}
17344 			} else if (len < segsiz) {
17345 				/*
17346 				 * Do we send any? The idea here is if the
17347 				 * send empty's the socket buffer we want to
17348 				 * do it. However if not then lets just wait
17349 				 * for our prr_sndcnt to get bigger.
17350 				 */
17351 				long leftinsb;
17352 
17353 				leftinsb = sbavail(sb) - sb_offset;
17354 				if (leftinsb > len) {
17355 					/* This send does not empty the sb */
17356 					len = 0;
17357 				}
17358 			}
17359 		}
17360 	} else if (!TCPS_HAVEESTABLISHED(tp->t_state)) {
17361 		/*
17362 		 * If you have not established
17363 		 * and are not doing FAST OPEN
17364 		 * no data please.
17365 		 */
17366 		if ((sack_rxmit == 0) &&
17367 		    (!IS_FASTOPEN(tp->t_flags))){
17368 			len = 0;
17369 			sb_offset = 0;
17370 		}
17371 	}
17372 	if (prefetch_so_done == 0) {
17373 		kern_prefetch(so, &prefetch_so_done);
17374 		prefetch_so_done = 1;
17375 	}
17376 	/*
17377 	 * Lop off SYN bit if it has already been sent.  However, if this is
17378 	 * SYN-SENT state and if segment contains data and if we don't know
17379 	 * that foreign host supports TAO, suppress sending segment.
17380 	 */
17381 	if ((flags & TH_SYN) && SEQ_GT(tp->snd_nxt, tp->snd_una) &&
17382 	    ((sack_rxmit == 0) && (tp->t_rxtshift == 0))) {
17383 		/*
17384 		 * When sending additional segments following a TFO SYN|ACK,
17385 		 * do not include the SYN bit.
17386 		 */
17387 		if (IS_FASTOPEN(tp->t_flags) &&
17388 		    (tp->t_state == TCPS_SYN_RECEIVED))
17389 			flags &= ~TH_SYN;
17390 	}
17391 	/*
17392 	 * Be careful not to send data and/or FIN on SYN segments. This
17393 	 * measure is needed to prevent interoperability problems with not
17394 	 * fully conformant TCP implementations.
17395 	 */
17396 	if ((flags & TH_SYN) && (tp->t_flags & TF_NOOPT)) {
17397 		len = 0;
17398 		flags &= ~TH_FIN;
17399 	}
17400 	/*
17401 	 * On TFO sockets, ensure no data is sent in the following cases:
17402 	 *
17403 	 *  - When retransmitting SYN|ACK on a passively-created socket
17404 	 *
17405 	 *  - When retransmitting SYN on an actively created socket
17406 	 *
17407 	 *  - When sending a zero-length cookie (cookie request) on an
17408 	 *    actively created socket
17409 	 *
17410 	 *  - When the socket is in the CLOSED state (RST is being sent)
17411 	 */
17412 	if (IS_FASTOPEN(tp->t_flags) &&
17413 	    (((flags & TH_SYN) && (tp->t_rxtshift > 0)) ||
17414 	     ((tp->t_state == TCPS_SYN_SENT) &&
17415 	      (tp->t_tfo_client_cookie_len == 0)) ||
17416 	     (flags & TH_RST))) {
17417 		sack_rxmit = 0;
17418 		len = 0;
17419 	}
17420 	/* Without fast-open there should never be data sent on a SYN */
17421 	if ((flags & TH_SYN) && (!IS_FASTOPEN(tp->t_flags))) {
17422 		tp->snd_nxt = tp->iss;
17423 		len = 0;
17424 	}
17425 	if ((len > segsiz) && (tcp_dsack_block_exists(tp))) {
17426 		/* We only send 1 MSS if we have a DSACK block */
17427 		add_flag |= RACK_SENT_W_DSACK;
17428 		len = segsiz;
17429 	}
17430 	orig_len = len;
17431 	if (len <= 0) {
17432 		/*
17433 		 * If FIN has been sent but not acked, but we haven't been
17434 		 * called to retransmit, len will be < 0.  Otherwise, window
17435 		 * shrank after we sent into it.  If window shrank to 0,
17436 		 * cancel pending retransmit, pull snd_nxt back to (closed)
17437 		 * window, and set the persist timer if it isn't already
17438 		 * going.  If the window didn't close completely, just wait
17439 		 * for an ACK.
17440 		 *
17441 		 * We also do a general check here to ensure that we will
17442 		 * set the persist timer when we have data to send, but a
17443 		 * 0-byte window. This makes sure the persist timer is set
17444 		 * even if the packet hits one of the "goto send" lines
17445 		 * below.
17446 		 */
17447 		len = 0;
17448 		if ((tp->snd_wnd == 0) &&
17449 		    (TCPS_HAVEESTABLISHED(tp->t_state)) &&
17450 		    (tp->snd_una == tp->snd_max) &&
17451 		    (sb_offset < (int)sbavail(sb))) {
17452 			rack_enter_persist(tp, rack, cts);
17453 		}
17454 	} else if ((rsm == NULL) &&
17455 		   (doing_tlp == 0) &&
17456 		   (len < pace_max_seg)) {
17457 		/*
17458 		 * We are not sending a maximum sized segment for
17459 		 * some reason. Should we not send anything (think
17460 		 * sws or persists)?
17461 		 */
17462 		if ((tp->snd_wnd < min((rack->r_ctl.rc_high_rwnd/2), minseg)) &&
17463 		    (TCPS_HAVEESTABLISHED(tp->t_state)) &&
17464 		    (len < minseg) &&
17465 		    (len < (int)(sbavail(sb) - sb_offset))) {
17466 			/*
17467 			 * Here the rwnd is less than
17468 			 * the minimum pacing size, this is not a retransmit,
17469 			 * we are established and
17470 			 * the send is not the last in the socket buffer
17471 			 * we send nothing, and we may enter persists
17472 			 * if nothing is outstanding.
17473 			 */
17474 			len = 0;
17475 			if (tp->snd_max == tp->snd_una) {
17476 				/*
17477 				 * Nothing out we can
17478 				 * go into persists.
17479 				 */
17480 				rack_enter_persist(tp, rack, cts);
17481 			}
17482 		     } else if ((cwnd_to_use >= max(minseg, (segsiz * 4))) &&
17483 			   (ctf_flight_size(tp, rack->r_ctl.rc_sacked) > (2 * segsiz)) &&
17484 			   (len < (int)(sbavail(sb) - sb_offset)) &&
17485 			   (len < minseg)) {
17486 			/*
17487 			 * Here we are not retransmitting, and
17488 			 * the cwnd is not so small that we could
17489 			 * not send at least a min size (rxt timer
17490 			 * not having gone off), We have 2 segments or
17491 			 * more already in flight, its not the tail end
17492 			 * of the socket buffer  and the cwnd is blocking
17493 			 * us from sending out a minimum pacing segment size.
17494 			 * Lets not send anything.
17495 			 */
17496 			len = 0;
17497 		} else if (((tp->snd_wnd - ctf_outstanding(tp)) <
17498 			    min((rack->r_ctl.rc_high_rwnd/2), minseg)) &&
17499 			   (ctf_flight_size(tp, rack->r_ctl.rc_sacked) > (2 * segsiz)) &&
17500 			   (len < (int)(sbavail(sb) - sb_offset)) &&
17501 			   (TCPS_HAVEESTABLISHED(tp->t_state))) {
17502 			/*
17503 			 * Here we have a send window but we have
17504 			 * filled it up and we can't send another pacing segment.
17505 			 * We also have in flight more than 2 segments
17506 			 * and we are not completing the sb i.e. we allow
17507 			 * the last bytes of the sb to go out even if
17508 			 * its not a full pacing segment.
17509 			 */
17510 			len = 0;
17511 		} else if ((rack->r_ctl.crte != NULL) &&
17512 			   (tp->snd_wnd >= (pace_max_seg * max(1, rack_hw_rwnd_factor))) &&
17513 			   (cwnd_to_use >= (pace_max_seg + (4 * segsiz))) &&
17514 			   (ctf_flight_size(tp, rack->r_ctl.rc_sacked) >= (2 * segsiz)) &&
17515 			   (len < (int)(sbavail(sb) - sb_offset))) {
17516 			/*
17517 			 * Here we are doing hardware pacing, this is not a TLP,
17518 			 * we are not sending a pace max segment size, there is rwnd
17519 			 * room to send at least N pace_max_seg, the cwnd is greater
17520 			 * than or equal to a full pacing segments plus 4 mss and we have 2 or
17521 			 * more segments in flight and its not the tail of the socket buffer.
17522 			 *
17523 			 * We don't want to send instead we need to get more ack's in to
17524 			 * allow us to send a full pacing segment. Normally, if we are pacing
17525 			 * about the right speed, we should have finished our pacing
17526 			 * send as most of the acks have come back if we are at the
17527 			 * right rate. This is a bit fuzzy since return path delay
17528 			 * can delay the acks, which is why we want to make sure we
17529 			 * have cwnd space to have a bit more than a max pace segments in flight.
17530 			 *
17531 			 * If we have not gotten our acks back we are pacing at too high a
17532 			 * rate delaying will not hurt and will bring our GP estimate down by
17533 			 * injecting the delay. If we don't do this we will send
17534 			 * 2 MSS out in response to the acks being clocked in which
17535 			 * defeats the point of hw-pacing (i.e. to help us get
17536 			 * larger TSO's out).
17537 			 */
17538 			len = 0;
17539 
17540 		}
17541 
17542 	}
17543 	/* len will be >= 0 after this point. */
17544 	KASSERT(len >= 0, ("[%s:%d]: len < 0", __func__, __LINE__));
17545 	rack_sndbuf_autoscale(rack);
17546 	/*
17547 	 * Decide if we can use TCP Segmentation Offloading (if supported by
17548 	 * hardware).
17549 	 *
17550 	 * TSO may only be used if we are in a pure bulk sending state.  The
17551 	 * presence of TCP-MD5, SACK retransmits, SACK advertizements and IP
17552 	 * options prevent using TSO.  With TSO the TCP header is the same
17553 	 * (except for the sequence number) for all generated packets.  This
17554 	 * makes it impossible to transmit any options which vary per
17555 	 * generated segment or packet.
17556 	 *
17557 	 * IPv4 handling has a clear separation of ip options and ip header
17558 	 * flags while IPv6 combines both in in6p_outputopts. ip6_optlen() does
17559 	 * the right thing below to provide length of just ip options and thus
17560 	 * checking for ipoptlen is enough to decide if ip options are present.
17561 	 */
17562 	ipoptlen = 0;
17563 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
17564 	/*
17565 	 * Pre-calculate here as we save another lookup into the darknesses
17566 	 * of IPsec that way and can actually decide if TSO is ok.
17567 	 */
17568 #ifdef INET6
17569 	if (isipv6 && IPSEC_ENABLED(ipv6))
17570 		ipsec_optlen = IPSEC_HDRSIZE(ipv6, inp);
17571 #ifdef INET
17572 	else
17573 #endif
17574 #endif				/* INET6 */
17575 #ifdef INET
17576 		if (IPSEC_ENABLED(ipv4))
17577 			ipsec_optlen = IPSEC_HDRSIZE(ipv4, inp);
17578 #endif				/* INET */
17579 #endif
17580 
17581 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
17582 	ipoptlen += ipsec_optlen;
17583 #endif
17584 	if ((tp->t_flags & TF_TSO) && V_tcp_do_tso && len > segsiz &&
17585 	    (tp->t_port == 0) &&
17586 	    ((tp->t_flags & TF_SIGNATURE) == 0) &&
17587 	    tp->rcv_numsacks == 0 && sack_rxmit == 0 &&
17588 	    ipoptlen == 0)
17589 		tso = 1;
17590 	{
17591 		uint32_t outstanding __unused;
17592 
17593 		outstanding = tp->snd_max - tp->snd_una;
17594 		if (tp->t_flags & TF_SENTFIN) {
17595 			/*
17596 			 * If we sent a fin, snd_max is 1 higher than
17597 			 * snd_una
17598 			 */
17599 			outstanding--;
17600 		}
17601 		if (sack_rxmit) {
17602 			if ((rsm->r_flags & RACK_HAS_FIN) == 0)
17603 				flags &= ~TH_FIN;
17604 		} else {
17605 			if (SEQ_LT(tp->snd_nxt + len, tp->snd_una +
17606 				   sbused(sb)))
17607 				flags &= ~TH_FIN;
17608 		}
17609 	}
17610 	recwin = lmin(lmax(sbspace(&so->so_rcv), 0),
17611 	    (long)TCP_MAXWIN << tp->rcv_scale);
17612 
17613 	/*
17614 	 * Sender silly window avoidance.   We transmit under the following
17615 	 * conditions when len is non-zero:
17616 	 *
17617 	 * - We have a full segment (or more with TSO) - This is the last
17618 	 * buffer in a write()/send() and we are either idle or running
17619 	 * NODELAY - we've timed out (e.g. persist timer) - we have more
17620 	 * then 1/2 the maximum send window's worth of data (receiver may be
17621 	 * limited the window size) - we need to retransmit
17622 	 */
17623 	if (len) {
17624 		if (len >= segsiz) {
17625 			goto send;
17626 		}
17627 		/*
17628 		 * NOTE! on localhost connections an 'ack' from the remote
17629 		 * end may occur synchronously with the output and cause us
17630 		 * to flush a buffer queued with moretocome.  XXX
17631 		 *
17632 		 */
17633 		if (!(tp->t_flags & TF_MORETOCOME) &&	/* normal case */
17634 		    (idle || (tp->t_flags & TF_NODELAY)) &&
17635 		    ((uint32_t)len + (uint32_t)sb_offset >= sbavail(sb)) &&
17636 		    (tp->t_flags & TF_NOPUSH) == 0) {
17637 			pass = 2;
17638 			goto send;
17639 		}
17640 		if ((tp->snd_una == tp->snd_max) && len) {	/* Nothing outstanding */
17641 			pass = 22;
17642 			goto send;
17643 		}
17644 		if (len >= tp->max_sndwnd / 2 && tp->max_sndwnd > 0) {
17645 			pass = 4;
17646 			goto send;
17647 		}
17648 		if (SEQ_LT(tp->snd_nxt, tp->snd_max)) {	/* retransmit case */
17649 			pass = 5;
17650 			goto send;
17651 		}
17652 		if (sack_rxmit) {
17653 			pass = 6;
17654 			goto send;
17655 		}
17656 		if (((tp->snd_wnd - ctf_outstanding(tp)) < segsiz) &&
17657 		    (ctf_outstanding(tp) < (segsiz * 2))) {
17658 			/*
17659 			 * We have less than two MSS outstanding (delayed ack)
17660 			 * and our rwnd will not let us send a full sized
17661 			 * MSS. Lets go ahead and let this small segment
17662 			 * out because we want to try to have at least two
17663 			 * packets inflight to not be caught by delayed ack.
17664 			 */
17665 			pass = 12;
17666 			goto send;
17667 		}
17668 	}
17669 	/*
17670 	 * Sending of standalone window updates.
17671 	 *
17672 	 * Window updates are important when we close our window due to a
17673 	 * full socket buffer and are opening it again after the application
17674 	 * reads data from it.  Once the window has opened again and the
17675 	 * remote end starts to send again the ACK clock takes over and
17676 	 * provides the most current window information.
17677 	 *
17678 	 * We must avoid the silly window syndrome whereas every read from
17679 	 * the receive buffer, no matter how small, causes a window update
17680 	 * to be sent.  We also should avoid sending a flurry of window
17681 	 * updates when the socket buffer had queued a lot of data and the
17682 	 * application is doing small reads.
17683 	 *
17684 	 * Prevent a flurry of pointless window updates by only sending an
17685 	 * update when we can increase the advertized window by more than
17686 	 * 1/4th of the socket buffer capacity.  When the buffer is getting
17687 	 * full or is very small be more aggressive and send an update
17688 	 * whenever we can increase by two mss sized segments. In all other
17689 	 * situations the ACK's to new incoming data will carry further
17690 	 * window increases.
17691 	 *
17692 	 * Don't send an independent window update if a delayed ACK is
17693 	 * pending (it will get piggy-backed on it) or the remote side
17694 	 * already has done a half-close and won't send more data.  Skip
17695 	 * this if the connection is in T/TCP half-open state.
17696 	 */
17697 	if (recwin > 0 && !(tp->t_flags & TF_NEEDSYN) &&
17698 	    !(tp->t_flags & TF_DELACK) &&
17699 	    !TCPS_HAVERCVDFIN(tp->t_state)) {
17700 		/*
17701 		 * "adv" is the amount we could increase the window, taking
17702 		 * into account that we are limited by TCP_MAXWIN <<
17703 		 * tp->rcv_scale.
17704 		 */
17705 		int32_t adv;
17706 		int oldwin;
17707 
17708 		adv = recwin;
17709 		if (SEQ_GT(tp->rcv_adv, tp->rcv_nxt)) {
17710 			oldwin = (tp->rcv_adv - tp->rcv_nxt);
17711 			if (adv > oldwin)
17712 			    adv -= oldwin;
17713 			else {
17714 				/* We can't increase the window */
17715 				adv = 0;
17716 			}
17717 		} else
17718 			oldwin = 0;
17719 
17720 		/*
17721 		 * If the new window size ends up being the same as or less
17722 		 * than the old size when it is scaled, then don't force
17723 		 * a window update.
17724 		 */
17725 		if (oldwin >> tp->rcv_scale >= (adv + oldwin) >> tp->rcv_scale)
17726 			goto dontupdate;
17727 
17728 		if (adv >= (int32_t)(2 * segsiz) &&
17729 		    (adv >= (int32_t)(so->so_rcv.sb_hiwat / 4) ||
17730 		     recwin <= (int32_t)(so->so_rcv.sb_hiwat / 8) ||
17731 		     so->so_rcv.sb_hiwat <= 8 * segsiz)) {
17732 			pass = 7;
17733 			goto send;
17734 		}
17735 		if (2 * adv >= (int32_t) so->so_rcv.sb_hiwat) {
17736 			pass = 23;
17737 			goto send;
17738 		}
17739 	}
17740 dontupdate:
17741 
17742 	/*
17743 	 * Send if we owe the peer an ACK, RST, SYN, or urgent data.  ACKNOW
17744 	 * is also a catch-all for the retransmit timer timeout case.
17745 	 */
17746 	if (tp->t_flags & TF_ACKNOW) {
17747 		pass = 8;
17748 		goto send;
17749 	}
17750 	if (((flags & TH_SYN) && (tp->t_flags & TF_NEEDSYN) == 0)) {
17751 		pass = 9;
17752 		goto send;
17753 	}
17754 	/*
17755 	 * If our state indicates that FIN should be sent and we have not
17756 	 * yet done so, then we need to send.
17757 	 */
17758 	if ((flags & TH_FIN) &&
17759 	    (tp->snd_nxt == tp->snd_una)) {
17760 		pass = 11;
17761 		goto send;
17762 	}
17763 	/*
17764 	 * No reason to send a segment, just return.
17765 	 */
17766 just_return:
17767 	SOCKBUF_UNLOCK(sb);
17768 just_return_nolock:
17769 	{
17770 		int app_limited = CTF_JR_SENT_DATA;
17771 
17772 		if (tot_len_this_send > 0) {
17773 			/* Make sure snd_nxt is up to max */
17774 			rack->r_ctl.fsb.recwin = recwin;
17775 			slot = rack_get_pacing_delay(rack, tp, tot_len_this_send, NULL, segsiz);
17776 			if ((error == 0) &&
17777 			    rack_use_rfo &&
17778 			    ((flags & (TH_SYN|TH_FIN)) == 0) &&
17779 			    (ipoptlen == 0) &&
17780 			    (tp->snd_nxt == tp->snd_max) &&
17781 			    (tp->rcv_numsacks == 0) &&
17782 			    rack->r_fsb_inited &&
17783 			    TCPS_HAVEESTABLISHED(tp->t_state) &&
17784 			    (rack->r_must_retran == 0) &&
17785 			    ((tp->t_flags & TF_NEEDFIN) == 0) &&
17786 			    (len > 0) && (orig_len > 0) &&
17787 			    (orig_len > len) &&
17788 			    ((orig_len - len) >= segsiz) &&
17789 			    ((optlen == 0) ||
17790 			     ((optlen == TCPOLEN_TSTAMP_APPA) && (to.to_flags & TOF_TS)))) {
17791 				/* We can send at least one more MSS using our fsb */
17792 
17793 				rack->r_fast_output = 1;
17794 				rack->r_ctl.fsb.m = sbsndmbuf(sb, (tp->snd_max - tp->snd_una), &rack->r_ctl.fsb.off);
17795 				rack->r_ctl.fsb.o_m_len = rack->r_ctl.fsb.m->m_len;
17796 				rack->r_ctl.fsb.tcp_flags = flags;
17797 				rack->r_ctl.fsb.left_to_send = orig_len - len;
17798 				if (hw_tls)
17799 					rack->r_ctl.fsb.hw_tls = 1;
17800 				else
17801 					rack->r_ctl.fsb.hw_tls = 0;
17802 				KASSERT((rack->r_ctl.fsb.left_to_send <= (sbavail(sb) - (tp->snd_max - tp->snd_una))),
17803 					("rack:%p left_to_send:%u sbavail:%u out:%u",
17804 					rack, rack->r_ctl.fsb.left_to_send, sbavail(sb),
17805 					 (tp->snd_max - tp->snd_una)));
17806 				if (rack->r_ctl.fsb.left_to_send < segsiz)
17807 					rack->r_fast_output = 0;
17808 				else {
17809 					if (rack->r_ctl.fsb.left_to_send == (sbavail(sb) - (tp->snd_max - tp->snd_una)))
17810 						rack->r_ctl.fsb.rfo_apply_push = 1;
17811 					else
17812 						rack->r_ctl.fsb.rfo_apply_push = 0;
17813 				}
17814 			} else
17815 				rack->r_fast_output = 0;
17816 
17817 
17818 			rack_log_fsb(rack, tp, so, flags,
17819 				     ipoptlen, orig_len, len, 0,
17820 				     1, optlen, __LINE__, 1);
17821 			if (SEQ_GT(tp->snd_max, tp->snd_nxt))
17822 				tp->snd_nxt = tp->snd_max;
17823 		} else {
17824 			int end_window = 0;
17825 			uint32_t seq = tp->gput_ack;
17826 
17827 			rsm = RB_MAX(rack_rb_tree_head, &rack->r_ctl.rc_mtree);
17828 			if (rsm) {
17829 				/*
17830 				 * Mark the last sent that we just-returned (hinting
17831 				 * that delayed ack may play a role in any rtt measurement).
17832 				 */
17833 				rsm->r_just_ret = 1;
17834 			}
17835 			counter_u64_add(rack_out_size[TCP_MSS_ACCT_JUSTRET], 1);
17836 			rack->r_ctl.rc_agg_delayed = 0;
17837 			rack->r_early = 0;
17838 			rack->r_late = 0;
17839 			rack->r_ctl.rc_agg_early = 0;
17840 			if ((ctf_outstanding(tp) +
17841 			     min(max(segsiz, (rack->r_ctl.rc_high_rwnd/2)),
17842 				 minseg)) >= tp->snd_wnd) {
17843 				/* We are limited by the rwnd */
17844 				app_limited = CTF_JR_RWND_LIMITED;
17845 				if (IN_FASTRECOVERY(tp->t_flags))
17846 				    rack->r_ctl.rc_prr_sndcnt = 0;
17847 			} else if (ctf_outstanding(tp) >= sbavail(sb)) {
17848 				/* We are limited by whats available -- app limited */
17849 				app_limited = CTF_JR_APP_LIMITED;
17850 				if (IN_FASTRECOVERY(tp->t_flags))
17851 				    rack->r_ctl.rc_prr_sndcnt = 0;
17852 			} else if ((idle == 0) &&
17853 				   ((tp->t_flags & TF_NODELAY) == 0) &&
17854 				   ((uint32_t)len + (uint32_t)sb_offset >= sbavail(sb)) &&
17855 				   (len < segsiz)) {
17856 				/*
17857 				 * No delay is not on and the
17858 				 * user is sending less than 1MSS. This
17859 				 * brings out SWS avoidance so we
17860 				 * don't send. Another app-limited case.
17861 				 */
17862 				app_limited = CTF_JR_APP_LIMITED;
17863 			} else if (tp->t_flags & TF_NOPUSH) {
17864 				/*
17865 				 * The user has requested no push of
17866 				 * the last segment and we are
17867 				 * at the last segment. Another app
17868 				 * limited case.
17869 				 */
17870 				app_limited = CTF_JR_APP_LIMITED;
17871 			} else if ((ctf_outstanding(tp) + minseg) > cwnd_to_use) {
17872 				/* Its the cwnd */
17873 				app_limited = CTF_JR_CWND_LIMITED;
17874 			} else if (IN_FASTRECOVERY(tp->t_flags) &&
17875 				   (rack->rack_no_prr == 0) &&
17876 				   (rack->r_ctl.rc_prr_sndcnt < segsiz)) {
17877 				app_limited = CTF_JR_PRR;
17878 			} else {
17879 				/* Now why here are we not sending? */
17880 #ifdef NOW
17881 #ifdef INVARIANTS
17882 				panic("rack:%p hit JR_ASSESSING case cwnd_to_use:%u?", rack, cwnd_to_use);
17883 #endif
17884 #endif
17885 				app_limited = CTF_JR_ASSESSING;
17886 			}
17887 			/*
17888 			 * App limited in some fashion, for our pacing GP
17889 			 * measurements we don't want any gap (even cwnd).
17890 			 * Close  down the measurement window.
17891 			 */
17892 			if (rack_cwnd_block_ends_measure &&
17893 			    ((app_limited == CTF_JR_CWND_LIMITED) ||
17894 			     (app_limited == CTF_JR_PRR))) {
17895 				/*
17896 				 * The reason we are not sending is
17897 				 * the cwnd (or prr). We have been configured
17898 				 * to end the measurement window in
17899 				 * this case.
17900 				 */
17901 				end_window = 1;
17902 			} else if (rack_rwnd_block_ends_measure &&
17903 				   (app_limited == CTF_JR_RWND_LIMITED)) {
17904 				/*
17905 				 * We are rwnd limited and have been
17906 				 * configured to end the measurement
17907 				 * window in this case.
17908 				 */
17909 				end_window = 1;
17910 			} else if (app_limited == CTF_JR_APP_LIMITED) {
17911 				/*
17912 				 * A true application limited period, we have
17913 				 * ran out of data.
17914 				 */
17915 				end_window = 1;
17916 			} else if (app_limited == CTF_JR_ASSESSING) {
17917 				/*
17918 				 * In the assessing case we hit the end of
17919 				 * the if/else and had no known reason
17920 				 * This will panic us under invariants..
17921 				 *
17922 				 * If we get this out in logs we need to
17923 				 * investagate which reason we missed.
17924 				 */
17925 				end_window = 1;
17926 			}
17927 			if (end_window) {
17928 				uint8_t log = 0;
17929 
17930 				/* Adjust the Gput measurement */
17931 				if ((tp->t_flags & TF_GPUTINPROG) &&
17932 				    SEQ_GT(tp->gput_ack, tp->snd_max)) {
17933 					tp->gput_ack = tp->snd_max;
17934 					if ((tp->gput_ack - tp->gput_seq) < (MIN_GP_WIN * segsiz)) {
17935 						/*
17936 						 * There is not enough to measure.
17937 						 */
17938 						tp->t_flags &= ~TF_GPUTINPROG;
17939 						rack_log_pacing_delay_calc(rack, (tp->gput_ack - tp->gput_seq) /*flex2*/,
17940 									   rack->r_ctl.rc_gp_srtt /*flex1*/,
17941 									   tp->gput_seq,
17942 									   0, 0, 18, __LINE__, NULL, 0);
17943 					} else
17944 						log = 1;
17945 				}
17946 				/* Mark the last packet has app limited */
17947 				rsm = RB_MAX(rack_rb_tree_head, &rack->r_ctl.rc_mtree);
17948 				if (rsm && ((rsm->r_flags & RACK_APP_LIMITED) == 0)) {
17949 					if (rack->r_ctl.rc_app_limited_cnt == 0)
17950 						rack->r_ctl.rc_end_appl = rack->r_ctl.rc_first_appl = rsm;
17951 					else {
17952 						/*
17953 						 * Go out to the end app limited and mark
17954 						 * this new one as next and move the end_appl up
17955 						 * to this guy.
17956 						 */
17957 						if (rack->r_ctl.rc_end_appl)
17958 							rack->r_ctl.rc_end_appl->r_nseq_appl = rsm->r_start;
17959 						rack->r_ctl.rc_end_appl = rsm;
17960 					}
17961 					rsm->r_flags |= RACK_APP_LIMITED;
17962 					rack->r_ctl.rc_app_limited_cnt++;
17963 				}
17964 				if (log)
17965 					rack_log_pacing_delay_calc(rack,
17966 								   rack->r_ctl.rc_app_limited_cnt, seq,
17967 								   tp->gput_ack, 0, 0, 4, __LINE__, NULL, 0);
17968 			}
17969 		}
17970 		/* Check if we need to go into persists or not */
17971 		if ((tp->snd_max == tp->snd_una) &&
17972 		    TCPS_HAVEESTABLISHED(tp->t_state) &&
17973 		    sbavail(sb) &&
17974 		    (sbavail(sb) > tp->snd_wnd) &&
17975 		    (tp->snd_wnd < min((rack->r_ctl.rc_high_rwnd/2), minseg))) {
17976 			/* Yes lets make sure to move to persist before timer-start */
17977 			rack_enter_persist(tp, rack, rack->r_ctl.rc_rcvtime);
17978 		}
17979 		rack_start_hpts_timer(rack, tp, cts, slot, tot_len_this_send, sup_rack);
17980 		rack_log_type_just_return(rack, cts, tot_len_this_send, slot, hpts_calling, app_limited, cwnd_to_use);
17981 	}
17982 #ifdef NETFLIX_SHARED_CWND
17983 	if ((sbavail(sb) == 0) &&
17984 	    rack->r_ctl.rc_scw) {
17985 		tcp_shared_cwnd_idle(rack->r_ctl.rc_scw, rack->r_ctl.rc_scw_index);
17986 		rack->rack_scwnd_is_idle = 1;
17987 	}
17988 #endif
17989 #ifdef TCP_ACCOUNTING
17990 	if (tot_len_this_send > 0) {
17991 		crtsc = get_cyclecount();
17992 		if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
17993 			tp->tcp_cnt_counters[SND_OUT_DATA]++;
17994 		}
17995 		counter_u64_add(tcp_cnt_counters[SND_OUT_DATA], 1);
17996 		if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
17997 			tp->tcp_proc_time[SND_OUT_DATA] += (crtsc - ts_val);
17998 		}
17999 		counter_u64_add(tcp_proc_time[SND_OUT_DATA], (crtsc - ts_val));
18000 		if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
18001 			tp->tcp_cnt_counters[CNT_OF_MSS_OUT] += ((tot_len_this_send + segsiz - 1) / segsiz);
18002 		}
18003 		counter_u64_add(tcp_cnt_counters[CNT_OF_MSS_OUT], ((tot_len_this_send + segsiz - 1) / segsiz));
18004 	} else {
18005 		crtsc = get_cyclecount();
18006 		if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
18007 			tp->tcp_cnt_counters[SND_LIMITED]++;
18008 		}
18009 		counter_u64_add(tcp_cnt_counters[SND_LIMITED], 1);
18010 		if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
18011 			tp->tcp_proc_time[SND_LIMITED] += (crtsc - ts_val);
18012 		}
18013 		counter_u64_add(tcp_proc_time[SND_LIMITED], (crtsc - ts_val));
18014 	}
18015 	sched_unpin();
18016 #endif
18017 	return (0);
18018 
18019 send:
18020 	if (rsm || sack_rxmit)
18021 		counter_u64_add(rack_nfto_resend, 1);
18022 	else
18023 		counter_u64_add(rack_non_fto_send, 1);
18024 	if ((flags & TH_FIN) &&
18025 	    sbavail(sb)) {
18026 		/*
18027 		 * We do not transmit a FIN
18028 		 * with data outstanding. We
18029 		 * need to make it so all data
18030 		 * is acked first.
18031 		 */
18032 		flags &= ~TH_FIN;
18033 	}
18034 	/* Enforce stack imposed max seg size if we have one */
18035 	if (rack->r_ctl.rc_pace_max_segs &&
18036 	    (len > rack->r_ctl.rc_pace_max_segs)) {
18037 		mark = 1;
18038 		len = rack->r_ctl.rc_pace_max_segs;
18039 	}
18040 	SOCKBUF_LOCK_ASSERT(sb);
18041 	if (len > 0) {
18042 		if (len >= segsiz)
18043 			tp->t_flags2 |= TF2_PLPMTU_MAXSEGSNT;
18044 		else
18045 			tp->t_flags2 &= ~TF2_PLPMTU_MAXSEGSNT;
18046 	}
18047 	/*
18048 	 * Before ESTABLISHED, force sending of initial options unless TCP
18049 	 * set not to do any options. NOTE: we assume that the IP/TCP header
18050 	 * plus TCP options always fit in a single mbuf, leaving room for a
18051 	 * maximum link header, i.e. max_linkhdr + sizeof (struct tcpiphdr)
18052 	 * + optlen <= MCLBYTES
18053 	 */
18054 	optlen = 0;
18055 #ifdef INET6
18056 	if (isipv6)
18057 		hdrlen = sizeof(struct ip6_hdr) + sizeof(struct tcphdr);
18058 	else
18059 #endif
18060 		hdrlen = sizeof(struct tcpiphdr);
18061 
18062 	/*
18063 	 * Compute options for segment. We only have to care about SYN and
18064 	 * established connection segments.  Options for SYN-ACK segments
18065 	 * are handled in TCP syncache.
18066 	 */
18067 	to.to_flags = 0;
18068 	if ((tp->t_flags & TF_NOOPT) == 0) {
18069 		/* Maximum segment size. */
18070 		if (flags & TH_SYN) {
18071 			tp->snd_nxt = tp->iss;
18072 			to.to_mss = tcp_mssopt(&inp->inp_inc);
18073 			if (tp->t_port)
18074 				to.to_mss -= V_tcp_udp_tunneling_overhead;
18075 			to.to_flags |= TOF_MSS;
18076 
18077 			/*
18078 			 * On SYN or SYN|ACK transmits on TFO connections,
18079 			 * only include the TFO option if it is not a
18080 			 * retransmit, as the presence of the TFO option may
18081 			 * have caused the original SYN or SYN|ACK to have
18082 			 * been dropped by a middlebox.
18083 			 */
18084 			if (IS_FASTOPEN(tp->t_flags) &&
18085 			    (tp->t_rxtshift == 0)) {
18086 				if (tp->t_state == TCPS_SYN_RECEIVED) {
18087 					to.to_tfo_len = TCP_FASTOPEN_COOKIE_LEN;
18088 					to.to_tfo_cookie =
18089 						(u_int8_t *)&tp->t_tfo_cookie.server;
18090 					to.to_flags |= TOF_FASTOPEN;
18091 					wanted_cookie = 1;
18092 				} else if (tp->t_state == TCPS_SYN_SENT) {
18093 					to.to_tfo_len =
18094 						tp->t_tfo_client_cookie_len;
18095 					to.to_tfo_cookie =
18096 						tp->t_tfo_cookie.client;
18097 					to.to_flags |= TOF_FASTOPEN;
18098 					wanted_cookie = 1;
18099 					/*
18100 					 * If we wind up having more data to
18101 					 * send with the SYN than can fit in
18102 					 * one segment, don't send any more
18103 					 * until the SYN|ACK comes back from
18104 					 * the other end.
18105 					 */
18106 					sendalot = 0;
18107 				}
18108 			}
18109 		}
18110 		/* Window scaling. */
18111 		if ((flags & TH_SYN) && (tp->t_flags & TF_REQ_SCALE)) {
18112 			to.to_wscale = tp->request_r_scale;
18113 			to.to_flags |= TOF_SCALE;
18114 		}
18115 		/* Timestamps. */
18116 		if ((tp->t_flags & TF_RCVD_TSTMP) ||
18117 		    ((flags & TH_SYN) && (tp->t_flags & TF_REQ_TSTMP))) {
18118 			to.to_tsval = ms_cts + tp->ts_offset;
18119 			to.to_tsecr = tp->ts_recent;
18120 			to.to_flags |= TOF_TS;
18121 		}
18122 		/* Set receive buffer autosizing timestamp. */
18123 		if (tp->rfbuf_ts == 0 &&
18124 		    (so->so_rcv.sb_flags & SB_AUTOSIZE))
18125 			tp->rfbuf_ts = tcp_ts_getticks();
18126 		/* Selective ACK's. */
18127 		if (tp->t_flags & TF_SACK_PERMIT) {
18128 			if (flags & TH_SYN)
18129 				to.to_flags |= TOF_SACKPERM;
18130 			else if (TCPS_HAVEESTABLISHED(tp->t_state) &&
18131 				 tp->rcv_numsacks > 0) {
18132 				to.to_flags |= TOF_SACK;
18133 				to.to_nsacks = tp->rcv_numsacks;
18134 				to.to_sacks = (u_char *)tp->sackblks;
18135 			}
18136 		}
18137 #if defined(IPSEC_SUPPORT) || defined(TCP_SIGNATURE)
18138 		/* TCP-MD5 (RFC2385). */
18139 		if (tp->t_flags & TF_SIGNATURE)
18140 			to.to_flags |= TOF_SIGNATURE;
18141 #endif				/* TCP_SIGNATURE */
18142 
18143 		/* Processing the options. */
18144 		hdrlen += optlen = tcp_addoptions(&to, opt);
18145 		/*
18146 		 * If we wanted a TFO option to be added, but it was unable
18147 		 * to fit, ensure no data is sent.
18148 		 */
18149 		if (IS_FASTOPEN(tp->t_flags) && wanted_cookie &&
18150 		    !(to.to_flags & TOF_FASTOPEN))
18151 			len = 0;
18152 	}
18153 	if (tp->t_port) {
18154 		if (V_tcp_udp_tunneling_port == 0) {
18155 			/* The port was removed?? */
18156 			SOCKBUF_UNLOCK(&so->so_snd);
18157 #ifdef TCP_ACCOUNTING
18158 			crtsc = get_cyclecount();
18159 			if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
18160 				tp->tcp_cnt_counters[SND_OUT_FAIL]++;
18161 			}
18162 			counter_u64_add(tcp_cnt_counters[SND_OUT_FAIL], 1);
18163 			if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
18164 				tp->tcp_proc_time[SND_OUT_FAIL] += (crtsc - ts_val);
18165 			}
18166 			counter_u64_add(tcp_proc_time[SND_OUT_FAIL], (crtsc - ts_val));
18167 			sched_unpin();
18168 #endif
18169 			return (EHOSTUNREACH);
18170 		}
18171 		hdrlen += sizeof(struct udphdr);
18172 	}
18173 #ifdef INET6
18174 	if (isipv6)
18175 		ipoptlen = ip6_optlen(inp);
18176 	else
18177 #endif
18178 		if (inp->inp_options)
18179 			ipoptlen = inp->inp_options->m_len -
18180 				offsetof(struct ipoption, ipopt_list);
18181 		else
18182 			ipoptlen = 0;
18183 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
18184 	ipoptlen += ipsec_optlen;
18185 #endif
18186 
18187 	/*
18188 	 * Adjust data length if insertion of options will bump the packet
18189 	 * length beyond the t_maxseg length. Clear the FIN bit because we
18190 	 * cut off the tail of the segment.
18191 	 */
18192 	if (len + optlen + ipoptlen > tp->t_maxseg) {
18193 		if (tso) {
18194 			uint32_t if_hw_tsomax;
18195 			uint32_t moff;
18196 			int32_t max_len;
18197 
18198 			/* extract TSO information */
18199 			if_hw_tsomax = tp->t_tsomax;
18200 			if_hw_tsomaxsegcount = tp->t_tsomaxsegcount;
18201 			if_hw_tsomaxsegsize = tp->t_tsomaxsegsize;
18202 			KASSERT(ipoptlen == 0,
18203 				("%s: TSO can't do IP options", __func__));
18204 
18205 			/*
18206 			 * Check if we should limit by maximum payload
18207 			 * length:
18208 			 */
18209 			if (if_hw_tsomax != 0) {
18210 				/* compute maximum TSO length */
18211 				max_len = (if_hw_tsomax - hdrlen -
18212 					   max_linkhdr);
18213 				if (max_len <= 0) {
18214 					len = 0;
18215 				} else if (len > max_len) {
18216 					sendalot = 1;
18217 					len = max_len;
18218 					mark = 2;
18219 				}
18220 			}
18221 			/*
18222 			 * Prevent the last segment from being fractional
18223 			 * unless the send sockbuf can be emptied:
18224 			 */
18225 			max_len = (tp->t_maxseg - optlen);
18226 			if ((sb_offset + len) < sbavail(sb)) {
18227 				moff = len % (u_int)max_len;
18228 				if (moff != 0) {
18229 					mark = 3;
18230 					len -= moff;
18231 				}
18232 			}
18233 			/*
18234 			 * In case there are too many small fragments don't
18235 			 * use TSO:
18236 			 */
18237 			if (len <= segsiz) {
18238 				mark = 4;
18239 				tso = 0;
18240 			}
18241 			/*
18242 			 * Send the FIN in a separate segment after the bulk
18243 			 * sending is done. We don't trust the TSO
18244 			 * implementations to clear the FIN flag on all but
18245 			 * the last segment.
18246 			 */
18247 			if (tp->t_flags & TF_NEEDFIN) {
18248 				sendalot = 4;
18249 			}
18250 		} else {
18251 			mark = 5;
18252 			if (optlen + ipoptlen >= tp->t_maxseg) {
18253 				/*
18254 				 * Since we don't have enough space to put
18255 				 * the IP header chain and the TCP header in
18256 				 * one packet as required by RFC 7112, don't
18257 				 * send it. Also ensure that at least one
18258 				 * byte of the payload can be put into the
18259 				 * TCP segment.
18260 				 */
18261 				SOCKBUF_UNLOCK(&so->so_snd);
18262 				error = EMSGSIZE;
18263 				sack_rxmit = 0;
18264 				goto out;
18265 			}
18266 			len = tp->t_maxseg - optlen - ipoptlen;
18267 			sendalot = 5;
18268 		}
18269 	} else {
18270 		tso = 0;
18271 		mark = 6;
18272 	}
18273 	KASSERT(len + hdrlen + ipoptlen <= IP_MAXPACKET,
18274 		("%s: len > IP_MAXPACKET", __func__));
18275 #ifdef DIAGNOSTIC
18276 #ifdef INET6
18277 	if (max_linkhdr + hdrlen > MCLBYTES)
18278 #else
18279 		if (max_linkhdr + hdrlen > MHLEN)
18280 #endif
18281 			panic("tcphdr too big");
18282 #endif
18283 
18284 	/*
18285 	 * This KASSERT is here to catch edge cases at a well defined place.
18286 	 * Before, those had triggered (random) panic conditions further
18287 	 * down.
18288 	 */
18289 	KASSERT(len >= 0, ("[%s:%d]: len < 0", __func__, __LINE__));
18290 	if ((len == 0) &&
18291 	    (flags & TH_FIN) &&
18292 	    (sbused(sb))) {
18293 		/*
18294 		 * We have outstanding data, don't send a fin by itself!.
18295 		 */
18296 		goto just_return;
18297 	}
18298 	/*
18299 	 * Grab a header mbuf, attaching a copy of data to be transmitted,
18300 	 * and initialize the header from the template for sends on this
18301 	 * connection.
18302 	 */
18303 	hw_tls = (sb->sb_flags & SB_TLS_IFNET) != 0;
18304 	if (len) {
18305 		uint32_t max_val;
18306 		uint32_t moff;
18307 
18308 		if (rack->r_ctl.rc_pace_max_segs)
18309 			max_val = rack->r_ctl.rc_pace_max_segs;
18310 		else if (rack->rc_user_set_max_segs)
18311 			max_val = rack->rc_user_set_max_segs * segsiz;
18312 		else
18313 			max_val = len;
18314 		/*
18315 		 * We allow a limit on sending with hptsi.
18316 		 */
18317 		if (len > max_val) {
18318 			mark = 7;
18319 			len = max_val;
18320 		}
18321 #ifdef INET6
18322 		if (MHLEN < hdrlen + max_linkhdr)
18323 			m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR);
18324 		else
18325 #endif
18326 			m = m_gethdr(M_NOWAIT, MT_DATA);
18327 
18328 		if (m == NULL) {
18329 			SOCKBUF_UNLOCK(sb);
18330 			error = ENOBUFS;
18331 			sack_rxmit = 0;
18332 			goto out;
18333 		}
18334 		m->m_data += max_linkhdr;
18335 		m->m_len = hdrlen;
18336 
18337 		/*
18338 		 * Start the m_copy functions from the closest mbuf to the
18339 		 * sb_offset in the socket buffer chain.
18340 		 */
18341 		mb = sbsndptr_noadv(sb, sb_offset, &moff);
18342 		s_mb = mb;
18343 		s_moff = moff;
18344 		if (len <= MHLEN - hdrlen - max_linkhdr && !hw_tls) {
18345 			m_copydata(mb, moff, (int)len,
18346 				   mtod(m, caddr_t)+hdrlen);
18347 			if (SEQ_LT(tp->snd_nxt, tp->snd_max))
18348 				sbsndptr_adv(sb, mb, len);
18349 			m->m_len += len;
18350 		} else {
18351 			struct sockbuf *msb;
18352 
18353 			if (SEQ_LT(tp->snd_nxt, tp->snd_max))
18354 				msb = NULL;
18355 			else
18356 				msb = sb;
18357 			m->m_next = tcp_m_copym(
18358 				mb, moff, &len,
18359 				if_hw_tsomaxsegcount, if_hw_tsomaxsegsize, msb,
18360 				((rsm == NULL) ? hw_tls : 0)
18361 #ifdef NETFLIX_COPY_ARGS
18362 				, &s_mb, &s_moff
18363 #endif
18364 				);
18365 			if (len <= (tp->t_maxseg - optlen)) {
18366 				/*
18367 				 * Must have ran out of mbufs for the copy
18368 				 * shorten it to no longer need tso. Lets
18369 				 * not put on sendalot since we are low on
18370 				 * mbufs.
18371 				 */
18372 				tso = 0;
18373 			}
18374 			if (m->m_next == NULL) {
18375 				SOCKBUF_UNLOCK(sb);
18376 				(void)m_free(m);
18377 				error = ENOBUFS;
18378 				sack_rxmit = 0;
18379 				goto out;
18380 			}
18381 		}
18382 		if (SEQ_LT(tp->snd_nxt, tp->snd_max) || sack_rxmit) {
18383 			if (rsm && (rsm->r_flags & RACK_TLP)) {
18384 				/*
18385 				 * TLP should not count in retran count, but
18386 				 * in its own bin
18387 				 */
18388 				counter_u64_add(rack_tlp_retran, 1);
18389 				counter_u64_add(rack_tlp_retran_bytes, len);
18390 			} else {
18391 				tp->t_sndrexmitpack++;
18392 				KMOD_TCPSTAT_INC(tcps_sndrexmitpack);
18393 				KMOD_TCPSTAT_ADD(tcps_sndrexmitbyte, len);
18394 			}
18395 #ifdef STATS
18396 			stats_voi_update_abs_u32(tp->t_stats, VOI_TCP_RETXPB,
18397 						 len);
18398 #endif
18399 		} else {
18400 			KMOD_TCPSTAT_INC(tcps_sndpack);
18401 			KMOD_TCPSTAT_ADD(tcps_sndbyte, len);
18402 #ifdef STATS
18403 			stats_voi_update_abs_u64(tp->t_stats, VOI_TCP_TXPB,
18404 						 len);
18405 #endif
18406 		}
18407 		/*
18408 		 * If we're sending everything we've got, set PUSH. (This
18409 		 * will keep happy those implementations which only give
18410 		 * data to the user when a buffer fills or a PUSH comes in.)
18411 		 */
18412 		if (sb_offset + len == sbused(sb) &&
18413 		    sbused(sb) &&
18414 		    !(flags & TH_SYN)) {
18415 			flags |= TH_PUSH;
18416 			add_flag |= RACK_HAD_PUSH;
18417 		}
18418 
18419 		SOCKBUF_UNLOCK(sb);
18420 	} else {
18421 		SOCKBUF_UNLOCK(sb);
18422 		if (tp->t_flags & TF_ACKNOW)
18423 			KMOD_TCPSTAT_INC(tcps_sndacks);
18424 		else if (flags & (TH_SYN | TH_FIN | TH_RST))
18425 			KMOD_TCPSTAT_INC(tcps_sndctrl);
18426 		else
18427 			KMOD_TCPSTAT_INC(tcps_sndwinup);
18428 
18429 		m = m_gethdr(M_NOWAIT, MT_DATA);
18430 		if (m == NULL) {
18431 			error = ENOBUFS;
18432 			sack_rxmit = 0;
18433 			goto out;
18434 		}
18435 #ifdef INET6
18436 		if (isipv6 && (MHLEN < hdrlen + max_linkhdr) &&
18437 		    MHLEN >= hdrlen) {
18438 			M_ALIGN(m, hdrlen);
18439 		} else
18440 #endif
18441 			m->m_data += max_linkhdr;
18442 		m->m_len = hdrlen;
18443 	}
18444 	SOCKBUF_UNLOCK_ASSERT(sb);
18445 	m->m_pkthdr.rcvif = (struct ifnet *)0;
18446 #ifdef MAC
18447 	mac_inpcb_create_mbuf(inp, m);
18448 #endif
18449 	if ((ipoptlen == 0) && (rack->r_ctl.fsb.tcp_ip_hdr) &&  rack->r_fsb_inited) {
18450 #ifdef INET6
18451 		if (isipv6)
18452 			ip6 = (struct ip6_hdr *)rack->r_ctl.fsb.tcp_ip_hdr;
18453 		else
18454 #endif				/* INET6 */
18455 			ip = (struct ip *)rack->r_ctl.fsb.tcp_ip_hdr;
18456 		th = rack->r_ctl.fsb.th;
18457 		udp = rack->r_ctl.fsb.udp;
18458 		if (udp) {
18459 #ifdef INET6
18460 			if (isipv6)
18461 				ulen = hdrlen + len - sizeof(struct ip6_hdr);
18462 			else
18463 #endif				/* INET6 */
18464 				ulen = hdrlen + len - sizeof(struct ip);
18465 			udp->uh_ulen = htons(ulen);
18466 		}
18467 	} else {
18468 #ifdef INET6
18469 		if (isipv6) {
18470 			ip6 = mtod(m, struct ip6_hdr *);
18471 			if (tp->t_port) {
18472 				udp = (struct udphdr *)((caddr_t)ip6 + sizeof(struct ip6_hdr));
18473 				udp->uh_sport = htons(V_tcp_udp_tunneling_port);
18474 				udp->uh_dport = tp->t_port;
18475 				ulen = hdrlen + len - sizeof(struct ip6_hdr);
18476 				udp->uh_ulen = htons(ulen);
18477 				th = (struct tcphdr *)(udp + 1);
18478 			} else
18479 				th = (struct tcphdr *)(ip6 + 1);
18480 			tcpip_fillheaders(inp, tp->t_port, ip6, th);
18481 		} else
18482 #endif				/* INET6 */
18483 		{
18484 			ip = mtod(m, struct ip *);
18485 			if (tp->t_port) {
18486 				udp = (struct udphdr *)((caddr_t)ip + sizeof(struct ip));
18487 				udp->uh_sport = htons(V_tcp_udp_tunneling_port);
18488 				udp->uh_dport = tp->t_port;
18489 				ulen = hdrlen + len - sizeof(struct ip);
18490 				udp->uh_ulen = htons(ulen);
18491 				th = (struct tcphdr *)(udp + 1);
18492 			} else
18493 				th = (struct tcphdr *)(ip + 1);
18494 			tcpip_fillheaders(inp, tp->t_port, ip, th);
18495 		}
18496 	}
18497 	/*
18498 	 * Fill in fields, remembering maximum advertised window for use in
18499 	 * delaying messages about window sizes. If resending a FIN, be sure
18500 	 * not to use a new sequence number.
18501 	 */
18502 	if (flags & TH_FIN && tp->t_flags & TF_SENTFIN &&
18503 	    tp->snd_nxt == tp->snd_max)
18504 		tp->snd_nxt--;
18505 	/*
18506 	 * If we are starting a connection, send ECN setup SYN packet. If we
18507 	 * are on a retransmit, we may resend those bits a number of times
18508 	 * as per RFC 3168.
18509 	 */
18510 	if (tp->t_state == TCPS_SYN_SENT && V_tcp_do_ecn) {
18511 		flags |= tcp_ecn_output_syn_sent(tp);
18512 	}
18513 	/* Also handle parallel SYN for ECN */
18514 	if (TCPS_HAVERCVDSYN(tp->t_state) &&
18515 	    (tp->t_flags2 & (TF2_ECN_PERMIT | TF2_ACE_PERMIT))) {
18516 		int ect = tcp_ecn_output_established(tp, &flags, len, sack_rxmit);
18517 		if ((tp->t_state == TCPS_SYN_RECEIVED) &&
18518 		    (tp->t_flags2 & TF2_ECN_SND_ECE))
18519 			tp->t_flags2 &= ~TF2_ECN_SND_ECE;
18520 #ifdef INET6
18521 		if (isipv6) {
18522 			ip6->ip6_flow &= ~htonl(IPTOS_ECN_MASK << 20);
18523 			ip6->ip6_flow |= htonl(ect << 20);
18524 		}
18525 		else
18526 #endif
18527 		{
18528 			ip->ip_tos &= ~IPTOS_ECN_MASK;
18529 			ip->ip_tos |= ect;
18530 		}
18531 	}
18532 	/*
18533 	 * If we are doing retransmissions, then snd_nxt will not reflect
18534 	 * the first unsent octet.  For ACK only packets, we do not want the
18535 	 * sequence number of the retransmitted packet, we want the sequence
18536 	 * number of the next unsent octet.  So, if there is no data (and no
18537 	 * SYN or FIN), use snd_max instead of snd_nxt when filling in
18538 	 * ti_seq.  But if we are in persist state, snd_max might reflect
18539 	 * one byte beyond the right edge of the window, so use snd_nxt in
18540 	 * that case, since we know we aren't doing a retransmission.
18541 	 * (retransmit and persist are mutually exclusive...)
18542 	 */
18543 	if (sack_rxmit == 0) {
18544 		if (len || (flags & (TH_SYN | TH_FIN))) {
18545 			th->th_seq = htonl(tp->snd_nxt);
18546 			rack_seq = tp->snd_nxt;
18547 		} else {
18548 			th->th_seq = htonl(tp->snd_max);
18549 			rack_seq = tp->snd_max;
18550 		}
18551 	} else {
18552 		th->th_seq = htonl(rsm->r_start);
18553 		rack_seq = rsm->r_start;
18554 	}
18555 	th->th_ack = htonl(tp->rcv_nxt);
18556 	tcp_set_flags(th, flags);
18557 	/*
18558 	 * Calculate receive window.  Don't shrink window, but avoid silly
18559 	 * window syndrome.
18560 	 * If a RST segment is sent, advertise a window of zero.
18561 	 */
18562 	if (flags & TH_RST) {
18563 		recwin = 0;
18564 	} else {
18565 		if (recwin < (long)(so->so_rcv.sb_hiwat / 4) &&
18566 		    recwin < (long)segsiz) {
18567 			recwin = 0;
18568 		}
18569 		if (SEQ_GT(tp->rcv_adv, tp->rcv_nxt) &&
18570 		    recwin < (long)(tp->rcv_adv - tp->rcv_nxt))
18571 			recwin = (long)(tp->rcv_adv - tp->rcv_nxt);
18572 	}
18573 
18574 	/*
18575 	 * According to RFC1323 the window field in a SYN (i.e., a <SYN> or
18576 	 * <SYN,ACK>) segment itself is never scaled.  The <SYN,ACK> case is
18577 	 * handled in syncache.
18578 	 */
18579 	if (flags & TH_SYN)
18580 		th->th_win = htons((u_short)
18581 				   (min(sbspace(&so->so_rcv), TCP_MAXWIN)));
18582 	else {
18583 		/* Avoid shrinking window with window scaling. */
18584 		recwin = roundup2(recwin, 1 << tp->rcv_scale);
18585 		th->th_win = htons((u_short)(recwin >> tp->rcv_scale));
18586 	}
18587 	/*
18588 	 * Adjust the RXWIN0SENT flag - indicate that we have advertised a 0
18589 	 * window.  This may cause the remote transmitter to stall.  This
18590 	 * flag tells soreceive() to disable delayed acknowledgements when
18591 	 * draining the buffer.  This can occur if the receiver is
18592 	 * attempting to read more data than can be buffered prior to
18593 	 * transmitting on the connection.
18594 	 */
18595 	if (th->th_win == 0) {
18596 		tp->t_sndzerowin++;
18597 		tp->t_flags |= TF_RXWIN0SENT;
18598 	} else
18599 		tp->t_flags &= ~TF_RXWIN0SENT;
18600 	tp->snd_up = tp->snd_una;	/* drag it along, its deprecated */
18601 	/* Now are we using fsb?, if so copy the template data to the mbuf */
18602 	if ((ipoptlen == 0) && (rack->r_ctl.fsb.tcp_ip_hdr) && rack->r_fsb_inited) {
18603 		uint8_t *cpto;
18604 
18605 		cpto = mtod(m, uint8_t *);
18606 		memcpy(cpto, rack->r_ctl.fsb.tcp_ip_hdr, rack->r_ctl.fsb.tcp_ip_hdr_len);
18607 		/*
18608 		 * We have just copied in:
18609 		 * IP/IP6
18610 		 * <optional udphdr>
18611 		 * tcphdr (no options)
18612 		 *
18613 		 * We need to grab the correct pointers into the mbuf
18614 		 * for both the tcp header, and possibly the udp header (if tunneling).
18615 		 * We do this by using the offset in the copy buffer and adding it
18616 		 * to the mbuf base pointer (cpto).
18617 		 */
18618 #ifdef INET6
18619 		if (isipv6)
18620 			ip6 = mtod(m, struct ip6_hdr *);
18621 		else
18622 #endif				/* INET6 */
18623 			ip = mtod(m, struct ip *);
18624 		th = (struct tcphdr *)(cpto + ((uint8_t *)rack->r_ctl.fsb.th - rack->r_ctl.fsb.tcp_ip_hdr));
18625 		/* If we have a udp header lets set it into the mbuf as well */
18626 		if (udp)
18627 			udp = (struct udphdr *)(cpto + ((uint8_t *)rack->r_ctl.fsb.udp - rack->r_ctl.fsb.tcp_ip_hdr));
18628 	}
18629 #if defined(IPSEC_SUPPORT) || defined(TCP_SIGNATURE)
18630 	if (to.to_flags & TOF_SIGNATURE) {
18631 		/*
18632 		 * Calculate MD5 signature and put it into the place
18633 		 * determined before.
18634 		 * NOTE: since TCP options buffer doesn't point into
18635 		 * mbuf's data, calculate offset and use it.
18636 		 */
18637 		if (!TCPMD5_ENABLED() || TCPMD5_OUTPUT(m, th,
18638 						       (u_char *)(th + 1) + (to.to_signature - opt)) != 0) {
18639 			/*
18640 			 * Do not send segment if the calculation of MD5
18641 			 * digest has failed.
18642 			 */
18643 			goto out;
18644 		}
18645 	}
18646 #endif
18647 	if (optlen) {
18648 		bcopy(opt, th + 1, optlen);
18649 		th->th_off = (sizeof(struct tcphdr) + optlen) >> 2;
18650 	}
18651 	/*
18652 	 * Put TCP length in extended header, and then checksum extended
18653 	 * header and data.
18654 	 */
18655 	m->m_pkthdr.len = hdrlen + len;	/* in6_cksum() need this */
18656 #ifdef INET6
18657 	if (isipv6) {
18658 		/*
18659 		 * ip6_plen is not need to be filled now, and will be filled
18660 		 * in ip6_output.
18661 		 */
18662 		if (tp->t_port) {
18663 			m->m_pkthdr.csum_flags = CSUM_UDP_IPV6;
18664 			m->m_pkthdr.csum_data = offsetof(struct udphdr, uh_sum);
18665 			udp->uh_sum = in6_cksum_pseudo(ip6, ulen, IPPROTO_UDP, 0);
18666 			th->th_sum = htons(0);
18667 			UDPSTAT_INC(udps_opackets);
18668 		} else {
18669 			m->m_pkthdr.csum_flags = CSUM_TCP_IPV6;
18670 			m->m_pkthdr.csum_data = offsetof(struct tcphdr, th_sum);
18671 			th->th_sum = in6_cksum_pseudo(ip6,
18672 						      sizeof(struct tcphdr) + optlen + len, IPPROTO_TCP,
18673 						      0);
18674 		}
18675 	}
18676 #endif
18677 #if defined(INET6) && defined(INET)
18678 	else
18679 #endif
18680 #ifdef INET
18681 	{
18682 		if (tp->t_port) {
18683 			m->m_pkthdr.csum_flags = CSUM_UDP;
18684 			m->m_pkthdr.csum_data = offsetof(struct udphdr, uh_sum);
18685 			udp->uh_sum = in_pseudo(ip->ip_src.s_addr,
18686 						ip->ip_dst.s_addr, htons(ulen + IPPROTO_UDP));
18687 			th->th_sum = htons(0);
18688 			UDPSTAT_INC(udps_opackets);
18689 		} else {
18690 			m->m_pkthdr.csum_flags = CSUM_TCP;
18691 			m->m_pkthdr.csum_data = offsetof(struct tcphdr, th_sum);
18692 			th->th_sum = in_pseudo(ip->ip_src.s_addr,
18693 					       ip->ip_dst.s_addr, htons(sizeof(struct tcphdr) +
18694 									IPPROTO_TCP + len + optlen));
18695 		}
18696 		/* IP version must be set here for ipv4/ipv6 checking later */
18697 		KASSERT(ip->ip_v == IPVERSION,
18698 			("%s: IP version incorrect: %d", __func__, ip->ip_v));
18699 	}
18700 #endif
18701 	/*
18702 	 * Enable TSO and specify the size of the segments. The TCP pseudo
18703 	 * header checksum is always provided. XXX: Fixme: This is currently
18704 	 * not the case for IPv6.
18705 	 */
18706 	if (tso) {
18707 		KASSERT(len > tp->t_maxseg - optlen,
18708 			("%s: len <= tso_segsz", __func__));
18709 		m->m_pkthdr.csum_flags |= CSUM_TSO;
18710 		m->m_pkthdr.tso_segsz = tp->t_maxseg - optlen;
18711 	}
18712 	KASSERT(len + hdrlen == m_length(m, NULL),
18713 		("%s: mbuf chain different than expected: %d + %u != %u",
18714 		 __func__, len, hdrlen, m_length(m, NULL)));
18715 
18716 #ifdef TCP_HHOOK
18717 	/* Run HHOOK_TCP_ESTABLISHED_OUT helper hooks. */
18718 	hhook_run_tcp_est_out(tp, th, &to, len, tso);
18719 #endif
18720 	/* We're getting ready to send; log now. */
18721 	if (tp->t_logstate != TCP_LOG_STATE_OFF) {
18722 		union tcp_log_stackspecific log;
18723 
18724 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
18725 		log.u_bbr.inhpts = tcp_in_hpts(rack->rc_inp);
18726 		if (rack->rack_no_prr)
18727 			log.u_bbr.flex1 = 0;
18728 		else
18729 			log.u_bbr.flex1 = rack->r_ctl.rc_prr_sndcnt;
18730 		log.u_bbr.flex2 = rack->r_ctl.rc_pace_min_segs;
18731 		log.u_bbr.flex3 = rack->r_ctl.rc_pace_max_segs;
18732 		log.u_bbr.flex4 = orig_len;
18733 		/* Save off the early/late values */
18734 		log.u_bbr.flex6 = rack->r_ctl.rc_agg_early;
18735 		log.u_bbr.applimited = rack->r_ctl.rc_agg_delayed;
18736 		log.u_bbr.bw_inuse = rack_get_bw(rack);
18737 		log.u_bbr.flex8 = 0;
18738 		if (rsm) {
18739 			if (rsm->r_flags & RACK_RWND_COLLAPSED) {
18740 				rack_log_collapse(rack, rsm->r_start, rsm->r_end, 0, __LINE__, 5, rsm->r_flags, rsm);
18741 				counter_u64_add(rack_collapsed_win_rxt, 1);
18742 				counter_u64_add(rack_collapsed_win_rxt_bytes, (rsm->r_end - rsm->r_start));
18743 			}
18744 			if (doing_tlp)
18745 				log.u_bbr.flex8 = 2;
18746 			else
18747 				log.u_bbr.flex8 = 1;
18748 		} else {
18749 			if (doing_tlp)
18750 				log.u_bbr.flex8 = 3;
18751 			else
18752 				log.u_bbr.flex8 = 0;
18753 		}
18754 		log.u_bbr.pacing_gain = rack_get_output_gain(rack, rsm);
18755 		log.u_bbr.flex7 = mark;
18756 		log.u_bbr.flex7 <<= 8;
18757 		log.u_bbr.flex7 |= pass;
18758 		log.u_bbr.pkts_out = tp->t_maxseg;
18759 		log.u_bbr.timeStamp = cts;
18760 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
18761 		log.u_bbr.lt_epoch = cwnd_to_use;
18762 		log.u_bbr.delivered = sendalot;
18763 		lgb = tcp_log_event_(tp, th, &so->so_rcv, &so->so_snd, TCP_LOG_OUT, ERRNO_UNK,
18764 				     len, &log, false, NULL, NULL, 0, &tv);
18765 	} else
18766 		lgb = NULL;
18767 
18768 	/*
18769 	 * Fill in IP length and desired time to live and send to IP level.
18770 	 * There should be a better way to handle ttl and tos; we could keep
18771 	 * them in the template, but need a way to checksum without them.
18772 	 */
18773 	/*
18774 	 * m->m_pkthdr.len should have been set before cksum calcuration,
18775 	 * because in6_cksum() need it.
18776 	 */
18777 #ifdef INET6
18778 	if (isipv6) {
18779 		/*
18780 		 * we separately set hoplimit for every segment, since the
18781 		 * user might want to change the value via setsockopt. Also,
18782 		 * desired default hop limit might be changed via Neighbor
18783 		 * Discovery.
18784 		 */
18785 		rack->r_ctl.fsb.hoplimit = ip6->ip6_hlim = in6_selecthlim(inp, NULL);
18786 
18787 		/*
18788 		 * Set the packet size here for the benefit of DTrace
18789 		 * probes. ip6_output() will set it properly; it's supposed
18790 		 * to include the option header lengths as well.
18791 		 */
18792 		ip6->ip6_plen = htons(m->m_pkthdr.len - sizeof(*ip6));
18793 
18794 		if (V_path_mtu_discovery && tp->t_maxseg > V_tcp_minmss)
18795 			tp->t_flags2 |= TF2_PLPMTU_PMTUD;
18796 		else
18797 			tp->t_flags2 &= ~TF2_PLPMTU_PMTUD;
18798 
18799 		if (tp->t_state == TCPS_SYN_SENT)
18800 			TCP_PROBE5(connect__request, NULL, tp, ip6, tp, th);
18801 
18802 		TCP_PROBE5(send, NULL, tp, ip6, tp, th);
18803 		/* TODO: IPv6 IP6TOS_ECT bit on */
18804 		error = ip6_output(m,
18805 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
18806 				   inp->in6p_outputopts,
18807 #else
18808 				   NULL,
18809 #endif
18810 				   &inp->inp_route6,
18811 				   ((rsm || sack_rxmit) ? IP_NO_SND_TAG_RL : 0),
18812 				   NULL, NULL, inp);
18813 
18814 		if (error == EMSGSIZE && inp->inp_route6.ro_nh != NULL)
18815 			mtu = inp->inp_route6.ro_nh->nh_mtu;
18816 	}
18817 #endif				/* INET6 */
18818 #if defined(INET) && defined(INET6)
18819 	else
18820 #endif
18821 #ifdef INET
18822 	{
18823 		ip->ip_len = htons(m->m_pkthdr.len);
18824 #ifdef INET6
18825 		if (inp->inp_vflag & INP_IPV6PROTO)
18826 			ip->ip_ttl = in6_selecthlim(inp, NULL);
18827 #endif				/* INET6 */
18828 		rack->r_ctl.fsb.hoplimit = ip->ip_ttl;
18829 		/*
18830 		 * If we do path MTU discovery, then we set DF on every
18831 		 * packet. This might not be the best thing to do according
18832 		 * to RFC3390 Section 2. However the tcp hostcache migitates
18833 		 * the problem so it affects only the first tcp connection
18834 		 * with a host.
18835 		 *
18836 		 * NB: Don't set DF on small MTU/MSS to have a safe
18837 		 * fallback.
18838 		 */
18839 		if (V_path_mtu_discovery && tp->t_maxseg > V_tcp_minmss) {
18840 			tp->t_flags2 |= TF2_PLPMTU_PMTUD;
18841 			if (tp->t_port == 0 || len < V_tcp_minmss) {
18842 				ip->ip_off |= htons(IP_DF);
18843 			}
18844 		} else {
18845 			tp->t_flags2 &= ~TF2_PLPMTU_PMTUD;
18846 		}
18847 
18848 		if (tp->t_state == TCPS_SYN_SENT)
18849 			TCP_PROBE5(connect__request, NULL, tp, ip, tp, th);
18850 
18851 		TCP_PROBE5(send, NULL, tp, ip, tp, th);
18852 
18853 		error = ip_output(m,
18854 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
18855 				  inp->inp_options,
18856 #else
18857 				  NULL,
18858 #endif
18859 				  &inp->inp_route,
18860 				  ((rsm || sack_rxmit) ? IP_NO_SND_TAG_RL : 0), 0,
18861 				  inp);
18862 		if (error == EMSGSIZE && inp->inp_route.ro_nh != NULL)
18863 			mtu = inp->inp_route.ro_nh->nh_mtu;
18864 	}
18865 #endif				/* INET */
18866 
18867 out:
18868 	if (lgb) {
18869 		lgb->tlb_errno = error;
18870 		lgb = NULL;
18871 	}
18872 	/*
18873 	 * In transmit state, time the transmission and arrange for the
18874 	 * retransmit.  In persist state, just set snd_max.
18875 	 */
18876 	if (error == 0) {
18877 		tcp_account_for_send(tp, len, (rsm != NULL), doing_tlp, hw_tls);
18878 		if (rsm && doing_tlp) {
18879 			rack->rc_last_sent_tlp_past_cumack = 0;
18880 			rack->rc_last_sent_tlp_seq_valid = 1;
18881 			rack->r_ctl.last_sent_tlp_seq = rsm->r_start;
18882 			rack->r_ctl.last_sent_tlp_len = rsm->r_end - rsm->r_start;
18883 		}
18884 		rack->forced_ack = 0;	/* If we send something zap the FA flag */
18885 		if (rsm && (doing_tlp == 0)) {
18886 			/* Set we retransmitted */
18887 			rack->rc_gp_saw_rec = 1;
18888 		} else {
18889 			if (cwnd_to_use > tp->snd_ssthresh) {
18890 				/* Set we sent in CA */
18891 				rack->rc_gp_saw_ca = 1;
18892 			} else {
18893 				/* Set we sent in SS */
18894 				rack->rc_gp_saw_ss = 1;
18895 			}
18896 		}
18897 		if (TCPS_HAVEESTABLISHED(tp->t_state) &&
18898 		    (tp->t_flags & TF_SACK_PERMIT) &&
18899 		    tp->rcv_numsacks > 0)
18900 			tcp_clean_dsack_blocks(tp);
18901 		tot_len_this_send += len;
18902 		if (len == 0)
18903 			counter_u64_add(rack_out_size[TCP_MSS_ACCT_SNDACK], 1);
18904 		else if (len == 1) {
18905 			counter_u64_add(rack_out_size[TCP_MSS_ACCT_PERSIST], 1);
18906 		} else if (len > 1) {
18907 			int idx;
18908 
18909 			idx = (len / segsiz) + 3;
18910 			if (idx >= TCP_MSS_ACCT_ATIMER)
18911 				counter_u64_add(rack_out_size[(TCP_MSS_ACCT_ATIMER-1)], 1);
18912 			else
18913 				counter_u64_add(rack_out_size[idx], 1);
18914 		}
18915 	}
18916 	if ((rack->rack_no_prr == 0) &&
18917 	    sub_from_prr &&
18918 	    (error == 0)) {
18919 		if (rack->r_ctl.rc_prr_sndcnt >= len)
18920 			rack->r_ctl.rc_prr_sndcnt -= len;
18921 		else
18922 			rack->r_ctl.rc_prr_sndcnt = 0;
18923 	}
18924 	sub_from_prr = 0;
18925 	if (doing_tlp) {
18926 		/* Make sure the TLP is added */
18927 		add_flag |= RACK_TLP;
18928 	} else if (rsm) {
18929 		/* If its a resend without TLP then it must not have the flag */
18930 		rsm->r_flags &= ~RACK_TLP;
18931 	}
18932 	rack_log_output(tp, &to, len, rack_seq, (uint8_t) flags, error,
18933 			rack_to_usec_ts(&tv),
18934 			rsm, add_flag, s_mb, s_moff, hw_tls);
18935 
18936 
18937 	if ((error == 0) &&
18938 	    (len > 0) &&
18939 	    (tp->snd_una == tp->snd_max))
18940 		rack->r_ctl.rc_tlp_rxt_last_time = cts;
18941 	{
18942 		tcp_seq startseq = tp->snd_nxt;
18943 
18944 		/* Track our lost count */
18945 		if (rsm && (doing_tlp == 0))
18946 			rack->r_ctl.rc_loss_count += rsm->r_end - rsm->r_start;
18947 		/*
18948 		 * Advance snd_nxt over sequence space of this segment.
18949 		 */
18950 		if (error)
18951 			/* We don't log or do anything with errors */
18952 			goto nomore;
18953 		if (doing_tlp == 0) {
18954 			if (rsm == NULL) {
18955 				/*
18956 				 * Not a retransmission of some
18957 				 * sort, new data is going out so
18958 				 * clear our TLP count and flag.
18959 				 */
18960 				rack->rc_tlp_in_progress = 0;
18961 				rack->r_ctl.rc_tlp_cnt_out = 0;
18962 			}
18963 		} else {
18964 			/*
18965 			 * We have just sent a TLP, mark that it is true
18966 			 * and make sure our in progress is set so we
18967 			 * continue to check the count.
18968 			 */
18969 			rack->rc_tlp_in_progress = 1;
18970 			rack->r_ctl.rc_tlp_cnt_out++;
18971 		}
18972 		if (flags & (TH_SYN | TH_FIN)) {
18973 			if (flags & TH_SYN)
18974 				tp->snd_nxt++;
18975 			if (flags & TH_FIN) {
18976 				tp->snd_nxt++;
18977 				tp->t_flags |= TF_SENTFIN;
18978 			}
18979 		}
18980 		/* In the ENOBUFS case we do *not* update snd_max */
18981 		if (sack_rxmit)
18982 			goto nomore;
18983 
18984 		tp->snd_nxt += len;
18985 		if (SEQ_GT(tp->snd_nxt, tp->snd_max)) {
18986 			if (tp->snd_una == tp->snd_max) {
18987 				/*
18988 				 * Update the time we just added data since
18989 				 * none was outstanding.
18990 				 */
18991 				rack_log_progress_event(rack, tp, ticks, PROGRESS_START, __LINE__);
18992 				tp->t_acktime = ticks;
18993 			}
18994 			tp->snd_max = tp->snd_nxt;
18995 			/*
18996 			 * Time this transmission if not a retransmission and
18997 			 * not currently timing anything.
18998 			 * This is only relevant in case of switching back to
18999 			 * the base stack.
19000 			 */
19001 			if (tp->t_rtttime == 0) {
19002 				tp->t_rtttime = ticks;
19003 				tp->t_rtseq = startseq;
19004 				KMOD_TCPSTAT_INC(tcps_segstimed);
19005 			}
19006 			if (len &&
19007 			    ((tp->t_flags & TF_GPUTINPROG) == 0))
19008 				rack_start_gp_measurement(tp, rack, startseq, sb_offset);
19009 		}
19010 		/*
19011 		 * If we are doing FO we need to update the mbuf position and subtract
19012 		 * this happens when the peer sends us duplicate information and
19013 		 * we thus want to send a DSACK.
19014 		 *
19015 		 * XXXRRS: This brings to mind a ?, when we send a DSACK block is TSO
19016 		 * turned off? If not then we are going to echo multiple DSACK blocks
19017 		 * out (with the TSO), which we should not be doing.
19018 		 */
19019 		if (rack->r_fast_output && len) {
19020 			if (rack->r_ctl.fsb.left_to_send > len)
19021 				rack->r_ctl.fsb.left_to_send -= len;
19022 			else
19023 				rack->r_ctl.fsb.left_to_send = 0;
19024 			if (rack->r_ctl.fsb.left_to_send < segsiz)
19025 				rack->r_fast_output = 0;
19026 			if (rack->r_fast_output) {
19027 				rack->r_ctl.fsb.m = sbsndmbuf(sb, (tp->snd_max - tp->snd_una), &rack->r_ctl.fsb.off);
19028 				rack->r_ctl.fsb.o_m_len = rack->r_ctl.fsb.m->m_len;
19029 			}
19030 		}
19031 	}
19032 nomore:
19033 	if (error) {
19034 		rack->r_ctl.rc_agg_delayed = 0;
19035 		rack->r_early = 0;
19036 		rack->r_late = 0;
19037 		rack->r_ctl.rc_agg_early = 0;
19038 		SOCKBUF_UNLOCK_ASSERT(sb);	/* Check gotos. */
19039 		/*
19040 		 * Failures do not advance the seq counter above. For the
19041 		 * case of ENOBUFS we will fall out and retry in 1ms with
19042 		 * the hpts. Everything else will just have to retransmit
19043 		 * with the timer.
19044 		 *
19045 		 * In any case, we do not want to loop around for another
19046 		 * send without a good reason.
19047 		 */
19048 		sendalot = 0;
19049 		switch (error) {
19050 		case EPERM:
19051 			tp->t_softerror = error;
19052 #ifdef TCP_ACCOUNTING
19053 			crtsc = get_cyclecount();
19054 			if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
19055 				tp->tcp_cnt_counters[SND_OUT_FAIL]++;
19056 			}
19057 			counter_u64_add(tcp_cnt_counters[SND_OUT_FAIL], 1);
19058 			if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
19059 				tp->tcp_proc_time[SND_OUT_FAIL] += (crtsc - ts_val);
19060 			}
19061 			counter_u64_add(tcp_proc_time[SND_OUT_FAIL], (crtsc - ts_val));
19062 			sched_unpin();
19063 #endif
19064 			return (error);
19065 		case ENOBUFS:
19066 			/*
19067 			 * Pace us right away to retry in a some
19068 			 * time
19069 			 */
19070 			if (rack->r_ctl.crte != NULL) {
19071 				rack_trace_point(rack, RACK_TP_HWENOBUF);
19072 			} else
19073 				rack_trace_point(rack, RACK_TP_ENOBUF);
19074 			slot = ((1 + rack->rc_enobuf) * HPTS_USEC_IN_MSEC);
19075 			if (rack->rc_enobuf < 0x7f)
19076 				rack->rc_enobuf++;
19077 			if (slot < (10 * HPTS_USEC_IN_MSEC))
19078 				slot = 10 * HPTS_USEC_IN_MSEC;
19079 			if (rack->r_ctl.crte != NULL) {
19080 				counter_u64_add(rack_saw_enobuf_hw, 1);
19081 				tcp_rl_log_enobuf(rack->r_ctl.crte);
19082 			}
19083 			counter_u64_add(rack_saw_enobuf, 1);
19084 			goto enobufs;
19085 		case EMSGSIZE:
19086 			/*
19087 			 * For some reason the interface we used initially
19088 			 * to send segments changed to another or lowered
19089 			 * its MTU. If TSO was active we either got an
19090 			 * interface without TSO capabilits or TSO was
19091 			 * turned off. If we obtained mtu from ip_output()
19092 			 * then update it and try again.
19093 			 */
19094 			if (tso)
19095 				tp->t_flags &= ~TF_TSO;
19096 			if (mtu != 0) {
19097 				tcp_mss_update(tp, -1, mtu, NULL, NULL);
19098 				goto again;
19099 			}
19100 			slot = 10 * HPTS_USEC_IN_MSEC;
19101 			rack_start_hpts_timer(rack, tp, cts, slot, 0, 0);
19102 #ifdef TCP_ACCOUNTING
19103 			crtsc = get_cyclecount();
19104 			if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
19105 				tp->tcp_cnt_counters[SND_OUT_FAIL]++;
19106 			}
19107 			counter_u64_add(tcp_cnt_counters[SND_OUT_FAIL], 1);
19108 			if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
19109 				tp->tcp_proc_time[SND_OUT_FAIL] += (crtsc - ts_val);
19110 			}
19111 			counter_u64_add(tcp_proc_time[SND_OUT_FAIL], (crtsc - ts_val));
19112 			sched_unpin();
19113 #endif
19114 			return (error);
19115 		case ENETUNREACH:
19116 			counter_u64_add(rack_saw_enetunreach, 1);
19117 		case EHOSTDOWN:
19118 		case EHOSTUNREACH:
19119 		case ENETDOWN:
19120 			if (TCPS_HAVERCVDSYN(tp->t_state)) {
19121 				tp->t_softerror = error;
19122 			}
19123 			/* FALLTHROUGH */
19124 		default:
19125 			slot = 10 * HPTS_USEC_IN_MSEC;
19126 			rack_start_hpts_timer(rack, tp, cts, slot, 0, 0);
19127 #ifdef TCP_ACCOUNTING
19128 			crtsc = get_cyclecount();
19129 			if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
19130 				tp->tcp_cnt_counters[SND_OUT_FAIL]++;
19131 			}
19132 			counter_u64_add(tcp_cnt_counters[SND_OUT_FAIL], 1);
19133 			if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
19134 				tp->tcp_proc_time[SND_OUT_FAIL] += (crtsc - ts_val);
19135 			}
19136 			counter_u64_add(tcp_proc_time[SND_OUT_FAIL], (crtsc - ts_val));
19137 			sched_unpin();
19138 #endif
19139 			return (error);
19140 		}
19141 	} else {
19142 		rack->rc_enobuf = 0;
19143 		if (IN_FASTRECOVERY(tp->t_flags) && rsm)
19144 			rack->r_ctl.retran_during_recovery += len;
19145 	}
19146 	KMOD_TCPSTAT_INC(tcps_sndtotal);
19147 
19148 	/*
19149 	 * Data sent (as far as we can tell). If this advertises a larger
19150 	 * window than any other segment, then remember the size of the
19151 	 * advertised window. Any pending ACK has now been sent.
19152 	 */
19153 	if (recwin > 0 && SEQ_GT(tp->rcv_nxt + recwin, tp->rcv_adv))
19154 		tp->rcv_adv = tp->rcv_nxt + recwin;
19155 
19156 	tp->last_ack_sent = tp->rcv_nxt;
19157 	tp->t_flags &= ~(TF_ACKNOW | TF_DELACK);
19158 enobufs:
19159 	if (sendalot) {
19160 		/* Do we need to turn off sendalot? */
19161 		if (rack->r_ctl.rc_pace_max_segs &&
19162 		    (tot_len_this_send >= rack->r_ctl.rc_pace_max_segs)) {
19163 			/* We hit our max. */
19164 			sendalot = 0;
19165 		} else if ((rack->rc_user_set_max_segs) &&
19166 			   (tot_len_this_send >= (rack->rc_user_set_max_segs * segsiz))) {
19167 			/* We hit the user defined max */
19168 			sendalot = 0;
19169 		}
19170 	}
19171 	if ((error == 0) && (flags & TH_FIN))
19172 		tcp_log_end_status(tp, TCP_EI_STATUS_SERVER_FIN);
19173 	if (flags & TH_RST) {
19174 		/*
19175 		 * We don't send again after sending a RST.
19176 		 */
19177 		slot = 0;
19178 		sendalot = 0;
19179 		if (error == 0)
19180 			tcp_log_end_status(tp, TCP_EI_STATUS_SERVER_RST);
19181 	} else if ((slot == 0) && (sendalot == 0) && tot_len_this_send) {
19182 		/*
19183 		 * Get our pacing rate, if an error
19184 		 * occurred in sending (ENOBUF) we would
19185 		 * hit the else if with slot preset. Other
19186 		 * errors return.
19187 		 */
19188 		slot = rack_get_pacing_delay(rack, tp, tot_len_this_send, rsm, segsiz);
19189 	}
19190 	if (rsm &&
19191 	    (rsm->r_flags & RACK_HAS_SYN) == 0 &&
19192 	    rack->use_rack_rr) {
19193 		/* Its a retransmit and we use the rack cheat? */
19194 		if ((slot == 0) ||
19195 		    (rack->rc_always_pace == 0) ||
19196 		    (rack->r_rr_config == 1)) {
19197 			/*
19198 			 * We have no pacing set or we
19199 			 * are using old-style rack or
19200 			 * we are overridden to use the old 1ms pacing.
19201 			 */
19202 			slot = rack->r_ctl.rc_min_to;
19203 		}
19204 	}
19205 	/* We have sent clear the flag */
19206 	rack->r_ent_rec_ns = 0;
19207 	if (rack->r_must_retran) {
19208 		if (rsm) {
19209 			rack->r_ctl.rc_out_at_rto -= (rsm->r_end - rsm->r_start);
19210 			if (SEQ_GEQ(rsm->r_end, rack->r_ctl.rc_snd_max_at_rto)) {
19211 				/*
19212 				 * We have retransmitted all.
19213 				 */
19214 				rack->r_must_retran = 0;
19215 				rack->r_ctl.rc_out_at_rto = 0;
19216 			}
19217 		} else if (SEQ_GEQ(tp->snd_max, rack->r_ctl.rc_snd_max_at_rto)) {
19218 			/*
19219 			 * Sending new data will also kill
19220 			 * the loop.
19221 			 */
19222 			rack->r_must_retran = 0;
19223 			rack->r_ctl.rc_out_at_rto = 0;
19224 		}
19225 	}
19226 	rack->r_ctl.fsb.recwin = recwin;
19227 	if ((tp->t_flags & (TF_WASCRECOVERY|TF_WASFRECOVERY)) &&
19228 	    SEQ_GT(tp->snd_max, rack->r_ctl.rc_snd_max_at_rto)) {
19229 		/*
19230 		 * We hit an RTO and now have past snd_max at the RTO
19231 		 * clear all the WAS flags.
19232 		 */
19233 		tp->t_flags &= ~(TF_WASCRECOVERY|TF_WASFRECOVERY);
19234 	}
19235 	if (slot) {
19236 		/* set the rack tcb into the slot N */
19237 		if ((error == 0) &&
19238 		    rack_use_rfo &&
19239 		    ((flags & (TH_SYN|TH_FIN)) == 0) &&
19240 		    (rsm == NULL) &&
19241 		    (tp->snd_nxt == tp->snd_max) &&
19242 		    (ipoptlen == 0) &&
19243 		    (tp->rcv_numsacks == 0) &&
19244 		    rack->r_fsb_inited &&
19245 		    TCPS_HAVEESTABLISHED(tp->t_state) &&
19246 		    (rack->r_must_retran == 0) &&
19247 		    ((tp->t_flags & TF_NEEDFIN) == 0) &&
19248 		    (len > 0) && (orig_len > 0) &&
19249 		    (orig_len > len) &&
19250 		    ((orig_len - len) >= segsiz) &&
19251 		    ((optlen == 0) ||
19252 		     ((optlen == TCPOLEN_TSTAMP_APPA) && (to.to_flags & TOF_TS)))) {
19253 			/* We can send at least one more MSS using our fsb */
19254 
19255 			rack->r_fast_output = 1;
19256 			rack->r_ctl.fsb.m = sbsndmbuf(sb, (tp->snd_max - tp->snd_una), &rack->r_ctl.fsb.off);
19257 			rack->r_ctl.fsb.o_m_len = rack->r_ctl.fsb.m->m_len;
19258 			rack->r_ctl.fsb.tcp_flags = flags;
19259 			rack->r_ctl.fsb.left_to_send = orig_len - len;
19260 			if (hw_tls)
19261 				rack->r_ctl.fsb.hw_tls = 1;
19262 			else
19263 				rack->r_ctl.fsb.hw_tls = 0;
19264 			KASSERT((rack->r_ctl.fsb.left_to_send <= (sbavail(sb) - (tp->snd_max - tp->snd_una))),
19265 				("rack:%p left_to_send:%u sbavail:%u out:%u",
19266 				 rack, rack->r_ctl.fsb.left_to_send, sbavail(sb),
19267 				 (tp->snd_max - tp->snd_una)));
19268 			if (rack->r_ctl.fsb.left_to_send < segsiz)
19269 				rack->r_fast_output = 0;
19270 			else {
19271 				if (rack->r_ctl.fsb.left_to_send == (sbavail(sb) - (tp->snd_max - tp->snd_una)))
19272 					rack->r_ctl.fsb.rfo_apply_push = 1;
19273 				else
19274 					rack->r_ctl.fsb.rfo_apply_push = 0;
19275 			}
19276 		} else
19277 			rack->r_fast_output = 0;
19278 		rack_log_fsb(rack, tp, so, flags,
19279 			     ipoptlen, orig_len, len, error,
19280 			     (rsm == NULL), optlen, __LINE__, 2);
19281 	} else if (sendalot) {
19282 		int ret;
19283 
19284 		sack_rxmit = 0;
19285 		if ((error == 0) &&
19286 		    rack_use_rfo &&
19287 		    ((flags & (TH_SYN|TH_FIN)) == 0) &&
19288 		    (rsm == NULL) &&
19289 		    (ipoptlen == 0) &&
19290 		    (tp->rcv_numsacks == 0) &&
19291 		    (tp->snd_nxt == tp->snd_max) &&
19292 		    (rack->r_must_retran == 0) &&
19293 		    rack->r_fsb_inited &&
19294 		    TCPS_HAVEESTABLISHED(tp->t_state) &&
19295 		    ((tp->t_flags & TF_NEEDFIN) == 0) &&
19296 		    (len > 0) && (orig_len > 0) &&
19297 		    (orig_len > len) &&
19298 		    ((orig_len - len) >= segsiz) &&
19299 		    ((optlen == 0) ||
19300 		     ((optlen == TCPOLEN_TSTAMP_APPA) && (to.to_flags & TOF_TS)))) {
19301 			/* we can use fast_output for more */
19302 
19303 			rack->r_fast_output = 1;
19304 			rack->r_ctl.fsb.m = sbsndmbuf(sb, (tp->snd_max - tp->snd_una), &rack->r_ctl.fsb.off);
19305 			rack->r_ctl.fsb.o_m_len = rack->r_ctl.fsb.m->m_len;
19306 			rack->r_ctl.fsb.tcp_flags = flags;
19307 			rack->r_ctl.fsb.left_to_send = orig_len - len;
19308 			if (hw_tls)
19309 				rack->r_ctl.fsb.hw_tls = 1;
19310 			else
19311 				rack->r_ctl.fsb.hw_tls = 0;
19312 			KASSERT((rack->r_ctl.fsb.left_to_send <= (sbavail(sb) - (tp->snd_max - tp->snd_una))),
19313 				("rack:%p left_to_send:%u sbavail:%u out:%u",
19314 				 rack, rack->r_ctl.fsb.left_to_send, sbavail(sb),
19315 				 (tp->snd_max - tp->snd_una)));
19316 			if (rack->r_ctl.fsb.left_to_send < segsiz) {
19317 				rack->r_fast_output = 0;
19318 			}
19319 			if (rack->r_fast_output) {
19320 				if (rack->r_ctl.fsb.left_to_send == (sbavail(sb) - (tp->snd_max - tp->snd_una)))
19321 					rack->r_ctl.fsb.rfo_apply_push = 1;
19322 				else
19323 					rack->r_ctl.fsb.rfo_apply_push = 0;
19324 				rack_log_fsb(rack, tp, so, flags,
19325 					     ipoptlen, orig_len, len, error,
19326 					     (rsm == NULL), optlen, __LINE__, 3);
19327 				error = 0;
19328 				ret = rack_fast_output(tp, rack, ts_val, cts, ms_cts, &tv, tot_len_this_send, &error);
19329 				if (ret >= 0)
19330 					return (ret);
19331 			        else if (error)
19332 					goto nomore;
19333 
19334 			}
19335 		}
19336 		goto again;
19337 	}
19338 	/* Assure when we leave that snd_nxt will point to top */
19339 	if (SEQ_GT(tp->snd_max, tp->snd_nxt))
19340 		tp->snd_nxt = tp->snd_max;
19341 	rack_start_hpts_timer(rack, tp, cts, slot, tot_len_this_send, 0);
19342 #ifdef TCP_ACCOUNTING
19343 	crtsc = get_cyclecount() - ts_val;
19344 	if (tot_len_this_send) {
19345 		if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
19346 			tp->tcp_cnt_counters[SND_OUT_DATA]++;
19347 		}
19348 		counter_u64_add(tcp_cnt_counters[SND_OUT_DATA], 1);
19349 		if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
19350 			tp->tcp_proc_time[SND_OUT_DATA] += crtsc;
19351 		}
19352 		counter_u64_add(tcp_proc_time[SND_OUT_DATA], crtsc);
19353 		if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
19354 			tp->tcp_cnt_counters[CNT_OF_MSS_OUT] += ((tot_len_this_send + segsiz - 1) /segsiz);
19355 		}
19356 		counter_u64_add(tcp_cnt_counters[CNT_OF_MSS_OUT], ((tot_len_this_send + segsiz - 1) /segsiz));
19357 	} else {
19358 		if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
19359 			tp->tcp_cnt_counters[SND_OUT_ACK]++;
19360 		}
19361 		counter_u64_add(tcp_cnt_counters[SND_OUT_ACK], 1);
19362 		if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
19363 			tp->tcp_proc_time[SND_OUT_ACK] += crtsc;
19364 		}
19365 		counter_u64_add(tcp_proc_time[SND_OUT_ACK], crtsc);
19366 	}
19367 	sched_unpin();
19368 #endif
19369 	if (error == ENOBUFS)
19370 		error = 0;
19371 	return (error);
19372 }
19373 
19374 static void
19375 rack_update_seg(struct tcp_rack *rack)
19376 {
19377 	uint32_t orig_val;
19378 
19379 	orig_val = rack->r_ctl.rc_pace_max_segs;
19380 	rack_set_pace_segments(rack->rc_tp, rack, __LINE__, NULL);
19381 	if (orig_val != rack->r_ctl.rc_pace_max_segs)
19382 		rack_log_pacing_delay_calc(rack, 0, 0, orig_val, 0, 0, 15, __LINE__, NULL, 0);
19383 }
19384 
19385 static void
19386 rack_mtu_change(struct tcpcb *tp)
19387 {
19388 	/*
19389 	 * The MSS may have changed
19390 	 */
19391 	struct tcp_rack *rack;
19392 	struct rack_sendmap *rsm;
19393 
19394 	rack = (struct tcp_rack *)tp->t_fb_ptr;
19395 	if (rack->r_ctl.rc_pace_min_segs != ctf_fixed_maxseg(tp)) {
19396 		/*
19397 		 * The MTU has changed we need to resend everything
19398 		 * since all we have sent is lost. We first fix
19399 		 * up the mtu though.
19400 		 */
19401 		rack_set_pace_segments(tp, rack, __LINE__, NULL);
19402 		/* We treat this like a full retransmit timeout without the cwnd adjustment */
19403 		rack_remxt_tmr(tp);
19404 		rack->r_fast_output = 0;
19405 		rack->r_ctl.rc_out_at_rto = ctf_flight_size(tp,
19406 						rack->r_ctl.rc_sacked);
19407 		rack->r_ctl.rc_snd_max_at_rto = tp->snd_max;
19408 		rack->r_must_retran = 1;
19409 		/* Mark all inflight to needing to be rxt'd */
19410 		TAILQ_FOREACH(rsm, &rack->r_ctl.rc_tmap, r_tnext) {
19411 			rsm->r_flags |= RACK_MUST_RXT;
19412 		}
19413 	}
19414 	sack_filter_clear(&rack->r_ctl.rack_sf, tp->snd_una);
19415 	/* We don't use snd_nxt to retransmit */
19416 	tp->snd_nxt = tp->snd_max;
19417 }
19418 
19419 static int
19420 rack_set_profile(struct tcp_rack *rack, int prof)
19421 {
19422 	int err = EINVAL;
19423 	if (prof == 1) {
19424 		/* pace_always=1 */
19425 		if (rack->rc_always_pace == 0) {
19426 			if (tcp_can_enable_pacing() == 0)
19427 				return (EBUSY);
19428 		}
19429 		rack->rc_always_pace = 1;
19430 		if (rack->use_fixed_rate || rack->gp_ready)
19431 			rack_set_cc_pacing(rack);
19432 		rack->rc_inp->inp_flags2 |= INP_SUPPORTS_MBUFQ;
19433 		rack->rack_attempt_hdwr_pace = 0;
19434 		/* cmpack=1 */
19435 		if (rack_use_cmp_acks)
19436 			rack->r_use_cmp_ack = 1;
19437 		if (TCPS_HAVEESTABLISHED(rack->rc_tp->t_state) &&
19438 		    rack->r_use_cmp_ack)
19439 			rack->rc_inp->inp_flags2 |= INP_MBUF_ACKCMP;
19440 		/* scwnd=1 */
19441 		rack->rack_enable_scwnd = 1;
19442 		/* dynamic=100 */
19443 		rack->rc_gp_dyn_mul = 1;
19444 		/* gp_inc_ca */
19445 		rack->r_ctl.rack_per_of_gp_ca = 100;
19446 		/* rrr_conf=3 */
19447 		rack->r_rr_config = 3;
19448 		/* npush=2 */
19449 		rack->r_ctl.rc_no_push_at_mrtt = 2;
19450 		/* fillcw=1 */
19451 		rack->rc_pace_to_cwnd = 1;
19452 		rack->rc_pace_fill_if_rttin_range = 0;
19453 		rack->rtt_limit_mul = 0;
19454 		/* noprr=1 */
19455 		rack->rack_no_prr = 1;
19456 		/* lscwnd=1 */
19457 		rack->r_limit_scw = 1;
19458 		/* gp_inc_rec */
19459 		rack->r_ctl.rack_per_of_gp_rec = 90;
19460 		err = 0;
19461 
19462 	} else if (prof == 3) {
19463 		/* Same as profile one execept fill_cw becomes 2 (less aggressive set) */
19464 		/* pace_always=1 */
19465 		if (rack->rc_always_pace == 0) {
19466 			if (tcp_can_enable_pacing() == 0)
19467 				return (EBUSY);
19468 		}
19469 		rack->rc_always_pace = 1;
19470 		if (rack->use_fixed_rate || rack->gp_ready)
19471 			rack_set_cc_pacing(rack);
19472 		rack->rc_inp->inp_flags2 |= INP_SUPPORTS_MBUFQ;
19473 		rack->rack_attempt_hdwr_pace = 0;
19474 		/* cmpack=1 */
19475 		if (rack_use_cmp_acks)
19476 			rack->r_use_cmp_ack = 1;
19477 		if (TCPS_HAVEESTABLISHED(rack->rc_tp->t_state) &&
19478 		    rack->r_use_cmp_ack)
19479 			rack->rc_inp->inp_flags2 |= INP_MBUF_ACKCMP;
19480 		/* scwnd=1 */
19481 		rack->rack_enable_scwnd = 1;
19482 		/* dynamic=100 */
19483 		rack->rc_gp_dyn_mul = 1;
19484 		/* gp_inc_ca */
19485 		rack->r_ctl.rack_per_of_gp_ca = 100;
19486 		/* rrr_conf=3 */
19487 		rack->r_rr_config = 3;
19488 		/* npush=2 */
19489 		rack->r_ctl.rc_no_push_at_mrtt = 2;
19490 		/* fillcw=2 */
19491 		rack->rc_pace_to_cwnd = 1;
19492 		rack->r_fill_less_agg = 1;
19493 		rack->rc_pace_fill_if_rttin_range = 0;
19494 		rack->rtt_limit_mul = 0;
19495 		/* noprr=1 */
19496 		rack->rack_no_prr = 1;
19497 		/* lscwnd=1 */
19498 		rack->r_limit_scw = 1;
19499 		/* gp_inc_rec */
19500 		rack->r_ctl.rack_per_of_gp_rec = 90;
19501 		err = 0;
19502 
19503 
19504 	} else if (prof == 2) {
19505 		/* cmpack=1 */
19506 		if (rack->rc_always_pace == 0) {
19507 			if (tcp_can_enable_pacing() == 0)
19508 				return (EBUSY);
19509 		}
19510 		rack->rc_always_pace = 1;
19511 		if (rack->use_fixed_rate || rack->gp_ready)
19512 			rack_set_cc_pacing(rack);
19513 		rack->r_use_cmp_ack = 1;
19514 		if (TCPS_HAVEESTABLISHED(rack->rc_tp->t_state))
19515 			rack->rc_inp->inp_flags2 |= INP_MBUF_ACKCMP;
19516 		/* pace_always=1 */
19517 		rack->rc_inp->inp_flags2 |= INP_SUPPORTS_MBUFQ;
19518 		/* scwnd=1 */
19519 		rack->rack_enable_scwnd = 1;
19520 		/* dynamic=100 */
19521 		rack->rc_gp_dyn_mul = 1;
19522 		rack->r_ctl.rack_per_of_gp_ca = 100;
19523 		/* rrr_conf=3 */
19524 		rack->r_rr_config = 3;
19525 		/* npush=2 */
19526 		rack->r_ctl.rc_no_push_at_mrtt = 2;
19527 		/* fillcw=1 */
19528 		rack->rc_pace_to_cwnd = 1;
19529 		rack->rc_pace_fill_if_rttin_range = 0;
19530 		rack->rtt_limit_mul = 0;
19531 		/* noprr=1 */
19532 		rack->rack_no_prr = 1;
19533 		/* lscwnd=0 */
19534 		rack->r_limit_scw = 0;
19535 		err = 0;
19536 	} else if (prof == 0) {
19537 		/* This changes things back to the default settings */
19538 		err = 0;
19539 		if (rack->rc_always_pace) {
19540 			tcp_decrement_paced_conn();
19541 			rack_undo_cc_pacing(rack);
19542 			rack->rc_always_pace = 0;
19543 		}
19544 		if (rack_pace_every_seg && tcp_can_enable_pacing()) {
19545 			rack->rc_always_pace = 1;
19546 			if (rack->use_fixed_rate || rack->gp_ready)
19547 				rack_set_cc_pacing(rack);
19548 		} else
19549 			rack->rc_always_pace = 0;
19550 		if (rack_dsack_std_based & 0x1) {
19551 			/* Basically this means all rack timers are at least (srtt + 1/4 srtt) */
19552 			rack->rc_rack_tmr_std_based = 1;
19553 		}
19554 		if (rack_dsack_std_based & 0x2) {
19555 			/* Basically this means  rack timers are extended based on dsack by up to (2 * srtt) */
19556 			rack->rc_rack_use_dsack = 1;
19557 		}
19558 		if (rack_use_cmp_acks)
19559 			rack->r_use_cmp_ack = 1;
19560 		else
19561 			rack->r_use_cmp_ack = 0;
19562 		if (rack_disable_prr)
19563 			rack->rack_no_prr = 1;
19564 		else
19565 			rack->rack_no_prr = 0;
19566 		if (rack_gp_no_rec_chg)
19567 			rack->rc_gp_no_rec_chg = 1;
19568 		else
19569 			rack->rc_gp_no_rec_chg = 0;
19570 		if (rack_enable_mqueue_for_nonpaced || rack->r_use_cmp_ack) {
19571 			rack->r_mbuf_queue = 1;
19572 			if (TCPS_HAVEESTABLISHED(rack->rc_tp->t_state))
19573 				rack->rc_inp->inp_flags2 |= INP_MBUF_ACKCMP;
19574 			rack->rc_inp->inp_flags2 |= INP_SUPPORTS_MBUFQ;
19575 		} else {
19576 			rack->r_mbuf_queue = 0;
19577 			rack->rc_inp->inp_flags2 &= ~INP_SUPPORTS_MBUFQ;
19578 		}
19579 		if (rack_enable_shared_cwnd)
19580 			rack->rack_enable_scwnd = 1;
19581 		else
19582 			rack->rack_enable_scwnd = 0;
19583 		if (rack_do_dyn_mul) {
19584 			/* When dynamic adjustment is on CA needs to start at 100% */
19585 			rack->rc_gp_dyn_mul = 1;
19586 			if (rack_do_dyn_mul >= 100)
19587 				rack->r_ctl.rack_per_of_gp_ca = rack_do_dyn_mul;
19588 		} else {
19589 			rack->r_ctl.rack_per_of_gp_ca = rack_per_of_gp_ca;
19590 			rack->rc_gp_dyn_mul = 0;
19591 		}
19592 		rack->r_rr_config = 0;
19593 		rack->r_ctl.rc_no_push_at_mrtt = 0;
19594 		rack->rc_pace_to_cwnd = 0;
19595 		rack->rc_pace_fill_if_rttin_range = 0;
19596 		rack->rtt_limit_mul = 0;
19597 
19598 		if (rack_enable_hw_pacing)
19599 			rack->rack_hdw_pace_ena = 1;
19600 		else
19601 			rack->rack_hdw_pace_ena = 0;
19602 		if (rack_disable_prr)
19603 			rack->rack_no_prr = 1;
19604 		else
19605 			rack->rack_no_prr = 0;
19606 		if (rack_limits_scwnd)
19607 			rack->r_limit_scw  = 1;
19608 		else
19609 			rack->r_limit_scw  = 0;
19610 		err = 0;
19611 	}
19612 	return (err);
19613 }
19614 
19615 static int
19616 rack_add_deferred_option(struct tcp_rack *rack, int sopt_name, uint64_t loptval)
19617 {
19618 	struct deferred_opt_list *dol;
19619 
19620 	dol = malloc(sizeof(struct deferred_opt_list),
19621 		     M_TCPFSB, M_NOWAIT|M_ZERO);
19622 	if (dol == NULL) {
19623 		/*
19624 		 * No space yikes -- fail out..
19625 		 */
19626 		return (0);
19627 	}
19628 	dol->optname = sopt_name;
19629 	dol->optval = loptval;
19630 	TAILQ_INSERT_TAIL(&rack->r_ctl.opt_list, dol, next);
19631 	return (1);
19632 }
19633 
19634 static int
19635 rack_process_option(struct tcpcb *tp, struct tcp_rack *rack, int sopt_name,
19636 		    uint32_t optval, uint64_t loptval)
19637 {
19638 	struct epoch_tracker et;
19639 	struct sockopt sopt;
19640 	struct cc_newreno_opts opt;
19641 	struct inpcb *inp = tptoinpcb(tp);
19642 	uint64_t val;
19643 	int error = 0;
19644 	uint16_t ca, ss;
19645 
19646 	switch (sopt_name) {
19647 
19648 	case TCP_RACK_DSACK_OPT:
19649 		RACK_OPTS_INC(tcp_rack_dsack_opt);
19650 		if (optval & 0x1) {
19651 			rack->rc_rack_tmr_std_based = 1;
19652 		} else {
19653 			rack->rc_rack_tmr_std_based = 0;
19654 		}
19655 		if (optval & 0x2) {
19656 			rack->rc_rack_use_dsack = 1;
19657 		} else {
19658 			rack->rc_rack_use_dsack = 0;
19659 		}
19660 		rack_log_dsack_event(rack, 5, __LINE__, 0, 0);
19661 		break;
19662 	case TCP_RACK_PACING_BETA:
19663 		RACK_OPTS_INC(tcp_rack_beta);
19664 		if (strcmp(tp->cc_algo->name, CCALGONAME_NEWRENO) != 0) {
19665 			/* This only works for newreno. */
19666 			error = EINVAL;
19667 			break;
19668 		}
19669 		if (rack->rc_pacing_cc_set) {
19670 			/*
19671 			 * Set them into the real CC module
19672 			 * whats in the rack pcb is the old values
19673 			 * to be used on restoral/
19674 			 */
19675 			sopt.sopt_dir = SOPT_SET;
19676 			opt.name = CC_NEWRENO_BETA;
19677 			opt.val = optval;
19678 			if (CC_ALGO(tp)->ctl_output != NULL)
19679 				error = CC_ALGO(tp)->ctl_output(tp->ccv, &sopt, &opt);
19680 			else {
19681 				error = ENOENT;
19682 				break;
19683 			}
19684 		} else {
19685 			/*
19686 			 * Not pacing yet so set it into our local
19687 			 * rack pcb storage.
19688 			 */
19689 			rack->r_ctl.rc_saved_beta.beta = optval;
19690 		}
19691 		break;
19692 	case TCP_RACK_TIMER_SLOP:
19693 		RACK_OPTS_INC(tcp_rack_timer_slop);
19694 		rack->r_ctl.timer_slop = optval;
19695 		if (rack->rc_tp->t_srtt) {
19696 			/*
19697 			 * If we have an SRTT lets update t_rxtcur
19698 			 * to have the new slop.
19699 			 */
19700 			RACK_TCPT_RANGESET(tp->t_rxtcur, RACK_REXMTVAL(tp),
19701 					   rack_rto_min, rack_rto_max,
19702 					   rack->r_ctl.timer_slop);
19703 		}
19704 		break;
19705 	case TCP_RACK_PACING_BETA_ECN:
19706 		RACK_OPTS_INC(tcp_rack_beta_ecn);
19707 		if (strcmp(tp->cc_algo->name, CCALGONAME_NEWRENO) != 0) {
19708 			/* This only works for newreno. */
19709 			error = EINVAL;
19710 			break;
19711 		}
19712 		if (rack->rc_pacing_cc_set) {
19713 			/*
19714 			 * Set them into the real CC module
19715 			 * whats in the rack pcb is the old values
19716 			 * to be used on restoral/
19717 			 */
19718 			sopt.sopt_dir = SOPT_SET;
19719 			opt.name = CC_NEWRENO_BETA_ECN;
19720 			opt.val = optval;
19721 			if (CC_ALGO(tp)->ctl_output != NULL)
19722 				error = CC_ALGO(tp)->ctl_output(tp->ccv, &sopt, &opt);
19723 			else
19724 				error = ENOENT;
19725 		} else {
19726 			/*
19727 			 * Not pacing yet so set it into our local
19728 			 * rack pcb storage.
19729 			 */
19730 			rack->r_ctl.rc_saved_beta.beta_ecn = optval;
19731 			rack->r_ctl.rc_saved_beta.newreno_flags = CC_NEWRENO_BETA_ECN_ENABLED;
19732 		}
19733 		break;
19734 	case TCP_DEFER_OPTIONS:
19735 		RACK_OPTS_INC(tcp_defer_opt);
19736 		if (optval) {
19737 			if (rack->gp_ready) {
19738 				/* Too late */
19739 				error = EINVAL;
19740 				break;
19741 			}
19742 			rack->defer_options = 1;
19743 		} else
19744 			rack->defer_options = 0;
19745 		break;
19746 	case TCP_RACK_MEASURE_CNT:
19747 		RACK_OPTS_INC(tcp_rack_measure_cnt);
19748 		if (optval && (optval <= 0xff)) {
19749 			rack->r_ctl.req_measurements = optval;
19750 		} else
19751 			error = EINVAL;
19752 		break;
19753 	case TCP_REC_ABC_VAL:
19754 		RACK_OPTS_INC(tcp_rec_abc_val);
19755 		if (optval > 0)
19756 			rack->r_use_labc_for_rec = 1;
19757 		else
19758 			rack->r_use_labc_for_rec = 0;
19759 		break;
19760 	case TCP_RACK_ABC_VAL:
19761 		RACK_OPTS_INC(tcp_rack_abc_val);
19762 		if ((optval > 0) && (optval < 255))
19763 			rack->rc_labc = optval;
19764 		else
19765 			error = EINVAL;
19766 		break;
19767 	case TCP_HDWR_UP_ONLY:
19768 		RACK_OPTS_INC(tcp_pacing_up_only);
19769 		if (optval)
19770 			rack->r_up_only = 1;
19771 		else
19772 			rack->r_up_only = 0;
19773 		break;
19774 	case TCP_PACING_RATE_CAP:
19775 		RACK_OPTS_INC(tcp_pacing_rate_cap);
19776 		rack->r_ctl.bw_rate_cap = loptval;
19777 		break;
19778 	case TCP_RACK_PROFILE:
19779 		RACK_OPTS_INC(tcp_profile);
19780 		error = rack_set_profile(rack, optval);
19781 		break;
19782 	case TCP_USE_CMP_ACKS:
19783 		RACK_OPTS_INC(tcp_use_cmp_acks);
19784 		if ((optval == 0) && (rack->rc_inp->inp_flags2 & INP_MBUF_ACKCMP)) {
19785 			/* You can't turn it off once its on! */
19786 			error = EINVAL;
19787 		} else if ((optval == 1) && (rack->r_use_cmp_ack == 0)) {
19788 			rack->r_use_cmp_ack = 1;
19789 			rack->r_mbuf_queue = 1;
19790 			inp->inp_flags2 |= INP_SUPPORTS_MBUFQ;
19791 		}
19792 		if (rack->r_use_cmp_ack && TCPS_HAVEESTABLISHED(tp->t_state))
19793 			inp->inp_flags2 |= INP_MBUF_ACKCMP;
19794 		break;
19795 	case TCP_SHARED_CWND_TIME_LIMIT:
19796 		RACK_OPTS_INC(tcp_lscwnd);
19797 		if (optval)
19798 			rack->r_limit_scw = 1;
19799 		else
19800 			rack->r_limit_scw = 0;
19801 		break;
19802  	case TCP_RACK_PACE_TO_FILL:
19803 		RACK_OPTS_INC(tcp_fillcw);
19804 		if (optval == 0)
19805 			rack->rc_pace_to_cwnd = 0;
19806 		else {
19807 			rack->rc_pace_to_cwnd = 1;
19808 			if (optval > 1)
19809 				rack->r_fill_less_agg = 1;
19810 		}
19811 		if ((optval >= rack_gp_rtt_maxmul) &&
19812 		    rack_gp_rtt_maxmul &&
19813 		    (optval < 0xf)) {
19814 			rack->rc_pace_fill_if_rttin_range = 1;
19815 			rack->rtt_limit_mul = optval;
19816 		} else {
19817 			rack->rc_pace_fill_if_rttin_range = 0;
19818 			rack->rtt_limit_mul = 0;
19819 		}
19820 		break;
19821 	case TCP_RACK_NO_PUSH_AT_MAX:
19822 		RACK_OPTS_INC(tcp_npush);
19823 		if (optval == 0)
19824 			rack->r_ctl.rc_no_push_at_mrtt = 0;
19825 		else if (optval < 0xff)
19826 			rack->r_ctl.rc_no_push_at_mrtt = optval;
19827 		else
19828 			error = EINVAL;
19829 		break;
19830 	case TCP_SHARED_CWND_ENABLE:
19831 		RACK_OPTS_INC(tcp_rack_scwnd);
19832 		if (optval == 0)
19833 			rack->rack_enable_scwnd = 0;
19834 		else
19835 			rack->rack_enable_scwnd = 1;
19836 		break;
19837 	case TCP_RACK_MBUF_QUEUE:
19838 		/* Now do we use the LRO mbuf-queue feature */
19839 		RACK_OPTS_INC(tcp_rack_mbufq);
19840 		if (optval || rack->r_use_cmp_ack)
19841 			rack->r_mbuf_queue = 1;
19842 		else
19843 			rack->r_mbuf_queue = 0;
19844 		if  (rack->r_mbuf_queue || rack->rc_always_pace || rack->r_use_cmp_ack)
19845 			inp->inp_flags2 |= INP_SUPPORTS_MBUFQ;
19846 		else
19847 			inp->inp_flags2 &= ~INP_SUPPORTS_MBUFQ;
19848 		break;
19849 	case TCP_RACK_NONRXT_CFG_RATE:
19850 		RACK_OPTS_INC(tcp_rack_cfg_rate);
19851 		if (optval == 0)
19852 			rack->rack_rec_nonrxt_use_cr = 0;
19853 		else
19854 			rack->rack_rec_nonrxt_use_cr = 1;
19855 		break;
19856 	case TCP_NO_PRR:
19857 		RACK_OPTS_INC(tcp_rack_noprr);
19858 		if (optval == 0)
19859 			rack->rack_no_prr = 0;
19860 		else if (optval == 1)
19861 			rack->rack_no_prr = 1;
19862 		else if (optval == 2)
19863 			rack->no_prr_addback = 1;
19864 		else
19865 			error = EINVAL;
19866 		break;
19867 	case TCP_TIMELY_DYN_ADJ:
19868 		RACK_OPTS_INC(tcp_timely_dyn);
19869 		if (optval == 0)
19870 			rack->rc_gp_dyn_mul = 0;
19871 		else {
19872 			rack->rc_gp_dyn_mul = 1;
19873 			if (optval >= 100) {
19874 				/*
19875 				 * If the user sets something 100 or more
19876 				 * its the gp_ca value.
19877 				 */
19878 				rack->r_ctl.rack_per_of_gp_ca  = optval;
19879 			}
19880 		}
19881 		break;
19882 	case TCP_RACK_DO_DETECTION:
19883 		RACK_OPTS_INC(tcp_rack_do_detection);
19884 		if (optval == 0)
19885 			rack->do_detection = 0;
19886 		else
19887 			rack->do_detection = 1;
19888 		break;
19889 	case TCP_RACK_TLP_USE:
19890 		if ((optval < TLP_USE_ID) || (optval > TLP_USE_TWO_TWO)) {
19891 			error = EINVAL;
19892 			break;
19893 		}
19894 		RACK_OPTS_INC(tcp_tlp_use);
19895 		rack->rack_tlp_threshold_use = optval;
19896 		break;
19897 	case TCP_RACK_TLP_REDUCE:
19898 		/* RACK TLP cwnd reduction (bool) */
19899 		RACK_OPTS_INC(tcp_rack_tlp_reduce);
19900 		rack->r_ctl.rc_tlp_cwnd_reduce = optval;
19901 		break;
19902 	/*  Pacing related ones */
19903 	case TCP_RACK_PACE_ALWAYS:
19904 		/*
19905 		 * zero is old rack method, 1 is new
19906 		 * method using a pacing rate.
19907 		 */
19908 		RACK_OPTS_INC(tcp_rack_pace_always);
19909 		if (optval > 0) {
19910 			if (rack->rc_always_pace) {
19911 				error = EALREADY;
19912 				break;
19913 			} else if (tcp_can_enable_pacing()) {
19914 				rack->rc_always_pace = 1;
19915 				if (rack->use_fixed_rate || rack->gp_ready)
19916 					rack_set_cc_pacing(rack);
19917 			}
19918 			else {
19919 				error = ENOSPC;
19920 				break;
19921 			}
19922 		} else {
19923 			if (rack->rc_always_pace) {
19924 				tcp_decrement_paced_conn();
19925 				rack->rc_always_pace = 0;
19926 				rack_undo_cc_pacing(rack);
19927 			}
19928 		}
19929 		if  (rack->r_mbuf_queue || rack->rc_always_pace || rack->r_use_cmp_ack)
19930 			inp->inp_flags2 |= INP_SUPPORTS_MBUFQ;
19931 		else
19932 			inp->inp_flags2 &= ~INP_SUPPORTS_MBUFQ;
19933 		/* A rate may be set irate or other, if so set seg size */
19934 		rack_update_seg(rack);
19935 		break;
19936 	case TCP_BBR_RACK_INIT_RATE:
19937 		RACK_OPTS_INC(tcp_initial_rate);
19938 		val = optval;
19939 		/* Change from kbits per second to bytes per second */
19940 		val *= 1000;
19941 		val /= 8;
19942 		rack->r_ctl.init_rate = val;
19943 		if (rack->rc_init_win != rack_default_init_window) {
19944 			uint32_t win, snt;
19945 
19946 			/*
19947 			 * Options don't always get applied
19948 			 * in the order you think. So in order
19949 			 * to assure we update a cwnd we need
19950 			 * to check and see if we are still
19951 			 * where we should raise the cwnd.
19952 			 */
19953 			win = rc_init_window(rack);
19954 			if (SEQ_GT(tp->snd_max, tp->iss))
19955 				snt = tp->snd_max - tp->iss;
19956 			else
19957 				snt = 0;
19958 			if ((snt < win) &&
19959 			    (tp->snd_cwnd < win))
19960 				tp->snd_cwnd = win;
19961 		}
19962 		if (rack->rc_always_pace)
19963 			rack_update_seg(rack);
19964 		break;
19965 	case TCP_BBR_IWINTSO:
19966 		RACK_OPTS_INC(tcp_initial_win);
19967 		if (optval && (optval <= 0xff)) {
19968 			uint32_t win, snt;
19969 
19970 			rack->rc_init_win = optval;
19971 			win = rc_init_window(rack);
19972 			if (SEQ_GT(tp->snd_max, tp->iss))
19973 				snt = tp->snd_max - tp->iss;
19974 			else
19975 				snt = 0;
19976 			if ((snt < win) &&
19977 			    (tp->t_srtt |
19978 #ifdef NETFLIX_PEAKRATE
19979 			     tp->t_maxpeakrate |
19980 #endif
19981 			     rack->r_ctl.init_rate)) {
19982 				/*
19983 				 * We are not past the initial window
19984 				 * and we have some bases for pacing,
19985 				 * so we need to possibly adjust up
19986 				 * the cwnd. Note even if we don't set
19987 				 * the cwnd, its still ok to raise the rc_init_win
19988 				 * which can be used coming out of idle when we
19989 				 * would have a rate.
19990 				 */
19991 				if (tp->snd_cwnd < win)
19992 					tp->snd_cwnd = win;
19993 			}
19994 			if (rack->rc_always_pace)
19995 				rack_update_seg(rack);
19996 		} else
19997 			error = EINVAL;
19998 		break;
19999 	case TCP_RACK_FORCE_MSEG:
20000 		RACK_OPTS_INC(tcp_rack_force_max_seg);
20001 		if (optval)
20002 			rack->rc_force_max_seg = 1;
20003 		else
20004 			rack->rc_force_max_seg = 0;
20005 		break;
20006 	case TCP_RACK_PACE_MAX_SEG:
20007 		/* Max segments size in a pace in bytes */
20008 		RACK_OPTS_INC(tcp_rack_max_seg);
20009 		rack->rc_user_set_max_segs = optval;
20010 		rack_set_pace_segments(tp, rack, __LINE__, NULL);
20011 		break;
20012 	case TCP_RACK_PACE_RATE_REC:
20013 		/* Set the fixed pacing rate in Bytes per second ca */
20014 		RACK_OPTS_INC(tcp_rack_pace_rate_rec);
20015 		rack->r_ctl.rc_fixed_pacing_rate_rec = optval;
20016 		if (rack->r_ctl.rc_fixed_pacing_rate_ca == 0)
20017 			rack->r_ctl.rc_fixed_pacing_rate_ca = optval;
20018 		if (rack->r_ctl.rc_fixed_pacing_rate_ss == 0)
20019 			rack->r_ctl.rc_fixed_pacing_rate_ss = optval;
20020 		rack->use_fixed_rate = 1;
20021 		if (rack->rc_always_pace)
20022 			rack_set_cc_pacing(rack);
20023 		rack_log_pacing_delay_calc(rack,
20024 					   rack->r_ctl.rc_fixed_pacing_rate_ss,
20025 					   rack->r_ctl.rc_fixed_pacing_rate_ca,
20026 					   rack->r_ctl.rc_fixed_pacing_rate_rec, 0, 0, 8,
20027 					   __LINE__, NULL,0);
20028 		break;
20029 
20030 	case TCP_RACK_PACE_RATE_SS:
20031 		/* Set the fixed pacing rate in Bytes per second ca */
20032 		RACK_OPTS_INC(tcp_rack_pace_rate_ss);
20033 		rack->r_ctl.rc_fixed_pacing_rate_ss = optval;
20034 		if (rack->r_ctl.rc_fixed_pacing_rate_ca == 0)
20035 			rack->r_ctl.rc_fixed_pacing_rate_ca = optval;
20036 		if (rack->r_ctl.rc_fixed_pacing_rate_rec == 0)
20037 			rack->r_ctl.rc_fixed_pacing_rate_rec = optval;
20038 		rack->use_fixed_rate = 1;
20039 		if (rack->rc_always_pace)
20040 			rack_set_cc_pacing(rack);
20041 		rack_log_pacing_delay_calc(rack,
20042 					   rack->r_ctl.rc_fixed_pacing_rate_ss,
20043 					   rack->r_ctl.rc_fixed_pacing_rate_ca,
20044 					   rack->r_ctl.rc_fixed_pacing_rate_rec, 0, 0, 8,
20045 					   __LINE__, NULL, 0);
20046 		break;
20047 
20048 	case TCP_RACK_PACE_RATE_CA:
20049 		/* Set the fixed pacing rate in Bytes per second ca */
20050 		RACK_OPTS_INC(tcp_rack_pace_rate_ca);
20051 		rack->r_ctl.rc_fixed_pacing_rate_ca = optval;
20052 		if (rack->r_ctl.rc_fixed_pacing_rate_ss == 0)
20053 			rack->r_ctl.rc_fixed_pacing_rate_ss = optval;
20054 		if (rack->r_ctl.rc_fixed_pacing_rate_rec == 0)
20055 			rack->r_ctl.rc_fixed_pacing_rate_rec = optval;
20056 		rack->use_fixed_rate = 1;
20057 		if (rack->rc_always_pace)
20058 			rack_set_cc_pacing(rack);
20059 		rack_log_pacing_delay_calc(rack,
20060 					   rack->r_ctl.rc_fixed_pacing_rate_ss,
20061 					   rack->r_ctl.rc_fixed_pacing_rate_ca,
20062 					   rack->r_ctl.rc_fixed_pacing_rate_rec, 0, 0, 8,
20063 					   __LINE__, NULL, 0);
20064 		break;
20065 	case TCP_RACK_GP_INCREASE_REC:
20066 		RACK_OPTS_INC(tcp_gp_inc_rec);
20067 		rack->r_ctl.rack_per_of_gp_rec = optval;
20068 		rack_log_pacing_delay_calc(rack,
20069 					   rack->r_ctl.rack_per_of_gp_ss,
20070 					   rack->r_ctl.rack_per_of_gp_ca,
20071 					   rack->r_ctl.rack_per_of_gp_rec, 0, 0, 1,
20072 					   __LINE__, NULL, 0);
20073 		break;
20074 	case TCP_RACK_GP_INCREASE_CA:
20075 		RACK_OPTS_INC(tcp_gp_inc_ca);
20076 		ca = optval;
20077 		if (ca < 100) {
20078 			/*
20079 			 * We don't allow any reduction
20080 			 * over the GP b/w.
20081 			 */
20082 			error = EINVAL;
20083 			break;
20084 		}
20085 		rack->r_ctl.rack_per_of_gp_ca = ca;
20086 		rack_log_pacing_delay_calc(rack,
20087 					   rack->r_ctl.rack_per_of_gp_ss,
20088 					   rack->r_ctl.rack_per_of_gp_ca,
20089 					   rack->r_ctl.rack_per_of_gp_rec, 0, 0, 1,
20090 					   __LINE__, NULL, 0);
20091 		break;
20092 	case TCP_RACK_GP_INCREASE_SS:
20093 		RACK_OPTS_INC(tcp_gp_inc_ss);
20094 		ss = optval;
20095 		if (ss < 100) {
20096 			/*
20097 			 * We don't allow any reduction
20098 			 * over the GP b/w.
20099 			 */
20100 			error = EINVAL;
20101 			break;
20102 		}
20103 		rack->r_ctl.rack_per_of_gp_ss = ss;
20104 		rack_log_pacing_delay_calc(rack,
20105 					   rack->r_ctl.rack_per_of_gp_ss,
20106 					   rack->r_ctl.rack_per_of_gp_ca,
20107 					   rack->r_ctl.rack_per_of_gp_rec, 0, 0, 1,
20108 					   __LINE__, NULL, 0);
20109 		break;
20110 	case TCP_RACK_RR_CONF:
20111 		RACK_OPTS_INC(tcp_rack_rrr_no_conf_rate);
20112 		if (optval && optval <= 3)
20113 			rack->r_rr_config = optval;
20114 		else
20115 			rack->r_rr_config = 0;
20116 		break;
20117 	case TCP_HDWR_RATE_CAP:
20118 		RACK_OPTS_INC(tcp_hdwr_rate_cap);
20119 		if (optval) {
20120 			if (rack->r_rack_hw_rate_caps == 0)
20121 				rack->r_rack_hw_rate_caps = 1;
20122 			else
20123 				error = EALREADY;
20124 		} else {
20125 			rack->r_rack_hw_rate_caps = 0;
20126 		}
20127 		break;
20128 	case TCP_BBR_HDWR_PACE:
20129 		RACK_OPTS_INC(tcp_hdwr_pacing);
20130 		if (optval){
20131 			if (rack->rack_hdrw_pacing == 0) {
20132 				rack->rack_hdw_pace_ena = 1;
20133 				rack->rack_attempt_hdwr_pace = 0;
20134 			} else
20135 				error = EALREADY;
20136 		} else {
20137 			rack->rack_hdw_pace_ena = 0;
20138 #ifdef RATELIMIT
20139 			if (rack->r_ctl.crte != NULL) {
20140 				rack->rack_hdrw_pacing = 0;
20141 				rack->rack_attempt_hdwr_pace = 0;
20142 				tcp_rel_pacing_rate(rack->r_ctl.crte, tp);
20143 				rack->r_ctl.crte = NULL;
20144 			}
20145 #endif
20146 		}
20147 		break;
20148 	/*  End Pacing related ones */
20149 	case TCP_RACK_PRR_SENDALOT:
20150 		/* Allow PRR to send more than one seg */
20151 		RACK_OPTS_INC(tcp_rack_prr_sendalot);
20152 		rack->r_ctl.rc_prr_sendalot = optval;
20153 		break;
20154 	case TCP_RACK_MIN_TO:
20155 		/* Minimum time between rack t-o's in ms */
20156 		RACK_OPTS_INC(tcp_rack_min_to);
20157 		rack->r_ctl.rc_min_to = optval;
20158 		break;
20159 	case TCP_RACK_EARLY_SEG:
20160 		/* If early recovery max segments */
20161 		RACK_OPTS_INC(tcp_rack_early_seg);
20162 		rack->r_ctl.rc_early_recovery_segs = optval;
20163 		break;
20164 	case TCP_RACK_ENABLE_HYSTART:
20165 	{
20166 		if (optval) {
20167 			tp->ccv->flags |= CCF_HYSTART_ALLOWED;
20168 			if (rack_do_hystart > RACK_HYSTART_ON)
20169 				tp->ccv->flags |= CCF_HYSTART_CAN_SH_CWND;
20170 			if (rack_do_hystart > RACK_HYSTART_ON_W_SC)
20171 				tp->ccv->flags |= CCF_HYSTART_CONS_SSTH;
20172 		} else {
20173 			tp->ccv->flags &= ~(CCF_HYSTART_ALLOWED|CCF_HYSTART_CAN_SH_CWND|CCF_HYSTART_CONS_SSTH);
20174 		}
20175 	}
20176 	break;
20177 	case TCP_RACK_REORD_THRESH:
20178 		/* RACK reorder threshold (shift amount) */
20179 		RACK_OPTS_INC(tcp_rack_reord_thresh);
20180 		if ((optval > 0) && (optval < 31))
20181 			rack->r_ctl.rc_reorder_shift = optval;
20182 		else
20183 			error = EINVAL;
20184 		break;
20185 	case TCP_RACK_REORD_FADE:
20186 		/* Does reordering fade after ms time */
20187 		RACK_OPTS_INC(tcp_rack_reord_fade);
20188 		rack->r_ctl.rc_reorder_fade = optval;
20189 		break;
20190 	case TCP_RACK_TLP_THRESH:
20191 		/* RACK TLP theshold i.e. srtt+(srtt/N) */
20192 		RACK_OPTS_INC(tcp_rack_tlp_thresh);
20193 		if (optval)
20194 			rack->r_ctl.rc_tlp_threshold = optval;
20195 		else
20196 			error = EINVAL;
20197 		break;
20198 	case TCP_BBR_USE_RACK_RR:
20199 		RACK_OPTS_INC(tcp_rack_rr);
20200 		if (optval)
20201 			rack->use_rack_rr = 1;
20202 		else
20203 			rack->use_rack_rr = 0;
20204 		break;
20205 	case TCP_FAST_RSM_HACK:
20206 		RACK_OPTS_INC(tcp_rack_fastrsm_hack);
20207 		if (optval)
20208 			rack->fast_rsm_hack = 1;
20209 		else
20210 			rack->fast_rsm_hack = 0;
20211 		break;
20212 	case TCP_RACK_PKT_DELAY:
20213 		/* RACK added ms i.e. rack-rtt + reord + N */
20214 		RACK_OPTS_INC(tcp_rack_pkt_delay);
20215 		rack->r_ctl.rc_pkt_delay = optval;
20216 		break;
20217 	case TCP_DELACK:
20218 		RACK_OPTS_INC(tcp_rack_delayed_ack);
20219 		if (optval == 0)
20220 			tp->t_delayed_ack = 0;
20221 		else
20222 			tp->t_delayed_ack = 1;
20223 		if (tp->t_flags & TF_DELACK) {
20224 			tp->t_flags &= ~TF_DELACK;
20225 			tp->t_flags |= TF_ACKNOW;
20226 			NET_EPOCH_ENTER(et);
20227 			rack_output(tp);
20228 			NET_EPOCH_EXIT(et);
20229 		}
20230 		break;
20231 
20232 	case TCP_BBR_RACK_RTT_USE:
20233 		RACK_OPTS_INC(tcp_rack_rtt_use);
20234 		if ((optval != USE_RTT_HIGH) &&
20235 		    (optval != USE_RTT_LOW) &&
20236 		    (optval != USE_RTT_AVG))
20237 			error = EINVAL;
20238 		else
20239 			rack->r_ctl.rc_rate_sample_method = optval;
20240 		break;
20241 	case TCP_DATA_AFTER_CLOSE:
20242 		RACK_OPTS_INC(tcp_data_after_close);
20243 		if (optval)
20244 			rack->rc_allow_data_af_clo = 1;
20245 		else
20246 			rack->rc_allow_data_af_clo = 0;
20247 		break;
20248 	default:
20249 		break;
20250 	}
20251 #ifdef NETFLIX_STATS
20252 	tcp_log_socket_option(tp, sopt_name, optval, error);
20253 #endif
20254 	return (error);
20255 }
20256 
20257 
20258 static void
20259 rack_apply_deferred_options(struct tcp_rack *rack)
20260 {
20261 	struct deferred_opt_list *dol, *sdol;
20262 	uint32_t s_optval;
20263 
20264 	TAILQ_FOREACH_SAFE(dol, &rack->r_ctl.opt_list, next, sdol) {
20265 		TAILQ_REMOVE(&rack->r_ctl.opt_list, dol, next);
20266 		/* Disadvantage of deferal is you loose the error return */
20267 		s_optval = (uint32_t)dol->optval;
20268 		(void)rack_process_option(rack->rc_tp, rack, dol->optname, s_optval, dol->optval);
20269 		free(dol, M_TCPDO);
20270 	}
20271 }
20272 
20273 static void
20274 rack_hw_tls_change(struct tcpcb *tp, int chg)
20275 {
20276 	/*
20277 	 * HW tls state has changed.. fix all
20278 	 * rsm's in flight.
20279 	 */
20280 	struct tcp_rack *rack;
20281 	struct rack_sendmap *rsm;
20282 
20283 	rack = (struct tcp_rack *)tp->t_fb_ptr;
20284 	RB_FOREACH(rsm, rack_rb_tree_head, &rack->r_ctl.rc_mtree) {
20285 		if (chg)
20286 			rsm->r_hw_tls = 1;
20287 		else
20288 			rsm->r_hw_tls = 0;
20289 	}
20290 	if (chg)
20291 		rack->r_ctl.fsb.hw_tls = 1;
20292 	else
20293 		rack->r_ctl.fsb.hw_tls = 0;
20294 }
20295 
20296 static int
20297 rack_pru_options(struct tcpcb *tp, int flags)
20298 {
20299 	if (flags & PRUS_OOB)
20300 		return (EOPNOTSUPP);
20301 	return (0);
20302 }
20303 
20304 static struct tcp_function_block __tcp_rack = {
20305 	.tfb_tcp_block_name = __XSTRING(STACKNAME),
20306 	.tfb_tcp_output = rack_output,
20307 	.tfb_do_queued_segments = ctf_do_queued_segments,
20308 	.tfb_do_segment_nounlock = rack_do_segment_nounlock,
20309 	.tfb_tcp_do_segment = rack_do_segment,
20310 	.tfb_tcp_ctloutput = rack_ctloutput,
20311 	.tfb_tcp_fb_init = rack_init,
20312 	.tfb_tcp_fb_fini = rack_fini,
20313 	.tfb_tcp_timer_stop_all = rack_stopall,
20314 	.tfb_tcp_timer_activate = rack_timer_activate,
20315 	.tfb_tcp_timer_active = rack_timer_active,
20316 	.tfb_tcp_timer_stop = rack_timer_stop,
20317 	.tfb_tcp_rexmit_tmr = rack_remxt_tmr,
20318 	.tfb_tcp_handoff_ok = rack_handoff_ok,
20319 	.tfb_tcp_mtu_chg = rack_mtu_change,
20320 	.tfb_pru_options = rack_pru_options,
20321 	.tfb_hwtls_change = rack_hw_tls_change,
20322 	.tfb_compute_pipe = rack_compute_pipe,
20323 	.tfb_flags = TCP_FUNC_OUTPUT_CANDROP,
20324 };
20325 
20326 /*
20327  * rack_ctloutput() must drop the inpcb lock before performing copyin on
20328  * socket option arguments.  When it re-acquires the lock after the copy, it
20329  * has to revalidate that the connection is still valid for the socket
20330  * option.
20331  */
20332 static int
20333 rack_set_sockopt(struct inpcb *inp, struct sockopt *sopt)
20334 {
20335 #ifdef INET6
20336 	struct ip6_hdr *ip6;
20337 #endif
20338 #ifdef INET
20339 	struct ip *ip;
20340 #endif
20341 	struct tcpcb *tp;
20342 	struct tcp_rack *rack;
20343 	uint64_t loptval;
20344 	int32_t error = 0, optval;
20345 
20346 	tp = intotcpcb(inp);
20347 	rack = (struct tcp_rack *)tp->t_fb_ptr;
20348 	if (rack == NULL) {
20349 		INP_WUNLOCK(inp);
20350 		return (EINVAL);
20351 	}
20352 #ifdef INET6
20353 	ip6 = (struct ip6_hdr *)rack->r_ctl.fsb.tcp_ip_hdr;
20354 #endif
20355 #ifdef INET
20356 	ip = (struct ip *)rack->r_ctl.fsb.tcp_ip_hdr;
20357 #endif
20358 
20359 	switch (sopt->sopt_level) {
20360 #ifdef INET6
20361 	case IPPROTO_IPV6:
20362 		MPASS(inp->inp_vflag & INP_IPV6PROTO);
20363 		switch (sopt->sopt_name) {
20364 		case IPV6_USE_MIN_MTU:
20365 			tcp6_use_min_mtu(tp);
20366 			break;
20367 		case IPV6_TCLASS:
20368 			/*
20369 			 * The DSCP codepoint has changed, update the fsb.
20370 			 */
20371 			ip6->ip6_flow = (ip6->ip6_flow & ~IPV6_FLOWINFO_MASK) |
20372 			    (rack->rc_inp->inp_flow & IPV6_FLOWINFO_MASK);
20373 			break;
20374 		}
20375 		INP_WUNLOCK(inp);
20376 		return (0);
20377 #endif
20378 #ifdef INET
20379 	case IPPROTO_IP:
20380 		switch (sopt->sopt_name) {
20381 		case IP_TOS:
20382 			/*
20383 			 * The DSCP codepoint has changed, update the fsb.
20384 			 */
20385 			ip->ip_tos = rack->rc_inp->inp_ip_tos;
20386 			break;
20387 		case IP_TTL:
20388 			/*
20389 			 * The TTL has changed, update the fsb.
20390 			 */
20391 			ip->ip_ttl = rack->rc_inp->inp_ip_ttl;
20392 			break;
20393 		}
20394 		INP_WUNLOCK(inp);
20395 		return (0);
20396 #endif
20397 	}
20398 
20399 	switch (sopt->sopt_name) {
20400 	case TCP_RACK_TLP_REDUCE:		/*  URL:tlp_reduce */
20401 	/*  Pacing related ones */
20402 	case TCP_RACK_PACE_ALWAYS:		/*  URL:pace_always */
20403 	case TCP_BBR_RACK_INIT_RATE:		/*  URL:irate */
20404 	case TCP_BBR_IWINTSO:			/*  URL:tso_iwin */
20405 	case TCP_RACK_PACE_MAX_SEG:		/*  URL:pace_max_seg */
20406 	case TCP_RACK_FORCE_MSEG:		/*  URL:force_max_seg */
20407 	case TCP_RACK_PACE_RATE_CA:		/*  URL:pr_ca */
20408 	case TCP_RACK_PACE_RATE_SS:		/*  URL:pr_ss*/
20409 	case TCP_RACK_PACE_RATE_REC:		/*  URL:pr_rec */
20410 	case TCP_RACK_GP_INCREASE_CA:		/*  URL:gp_inc_ca */
20411 	case TCP_RACK_GP_INCREASE_SS:		/*  URL:gp_inc_ss */
20412 	case TCP_RACK_GP_INCREASE_REC:		/*  URL:gp_inc_rec */
20413 	case TCP_RACK_RR_CONF:			/*  URL:rrr_conf */
20414 	case TCP_BBR_HDWR_PACE:			/*  URL:hdwrpace */
20415 	case TCP_HDWR_RATE_CAP:			/*  URL:hdwrcap boolean */
20416 	case TCP_PACING_RATE_CAP:		/*  URL:cap  -- used by side-channel */
20417 	case TCP_HDWR_UP_ONLY:			/*  URL:uponly -- hardware pacing  boolean */
20418        /* End pacing related */
20419 	case TCP_FAST_RSM_HACK:			/*  URL:frsm_hack */
20420 	case TCP_DELACK:			/*  URL:delack (in base TCP i.e. tcp_hints along with cc etc ) */
20421 	case TCP_RACK_PRR_SENDALOT:		/*  URL:prr_sendalot */
20422 	case TCP_RACK_MIN_TO:			/*  URL:min_to */
20423 	case TCP_RACK_EARLY_SEG:		/*  URL:early_seg */
20424 	case TCP_RACK_REORD_THRESH:		/*  URL:reord_thresh */
20425 	case TCP_RACK_REORD_FADE:		/*  URL:reord_fade */
20426 	case TCP_RACK_TLP_THRESH:		/*  URL:tlp_thresh */
20427 	case TCP_RACK_PKT_DELAY:		/*  URL:pkt_delay */
20428 	case TCP_RACK_TLP_USE:			/*  URL:tlp_use */
20429 	case TCP_BBR_RACK_RTT_USE:		/*  URL:rttuse */
20430 	case TCP_BBR_USE_RACK_RR:		/*  URL:rackrr */
20431 	case TCP_RACK_DO_DETECTION:		/*  URL:detect */
20432 	case TCP_NO_PRR:			/*  URL:noprr */
20433 	case TCP_TIMELY_DYN_ADJ:      		/*  URL:dynamic */
20434 	case TCP_DATA_AFTER_CLOSE:		/*  no URL */
20435 	case TCP_RACK_NONRXT_CFG_RATE:		/*  URL:nonrxtcr */
20436 	case TCP_SHARED_CWND_ENABLE:		/*  URL:scwnd */
20437 	case TCP_RACK_MBUF_QUEUE:		/*  URL:mqueue */
20438 	case TCP_RACK_NO_PUSH_AT_MAX:		/*  URL:npush */
20439 	case TCP_RACK_PACE_TO_FILL:		/*  URL:fillcw */
20440 	case TCP_SHARED_CWND_TIME_LIMIT:	/*  URL:lscwnd */
20441 	case TCP_RACK_PROFILE:			/*  URL:profile */
20442 	case TCP_USE_CMP_ACKS:			/*  URL:cmpack */
20443 	case TCP_RACK_ABC_VAL:			/*  URL:labc */
20444 	case TCP_REC_ABC_VAL:			/*  URL:reclabc */
20445 	case TCP_RACK_MEASURE_CNT:		/*  URL:measurecnt */
20446 	case TCP_DEFER_OPTIONS:			/*  URL:defer */
20447 	case TCP_RACK_DSACK_OPT:		/*  URL:dsack */
20448 	case TCP_RACK_PACING_BETA:		/*  URL:pacing_beta */
20449 	case TCP_RACK_PACING_BETA_ECN:		/*  URL:pacing_beta_ecn */
20450 	case TCP_RACK_TIMER_SLOP:		/*  URL:timer_slop */
20451 	case TCP_RACK_ENABLE_HYSTART:		/*  URL:hystart */
20452 		break;
20453 	default:
20454 		/* Filter off all unknown options to the base stack */
20455 		return (tcp_default_ctloutput(inp, sopt));
20456 		break;
20457 	}
20458 	INP_WUNLOCK(inp);
20459 	if (sopt->sopt_name == TCP_PACING_RATE_CAP) {
20460 		error = sooptcopyin(sopt, &loptval, sizeof(loptval), sizeof(loptval));
20461 		/*
20462 		 * We truncate it down to 32 bits for the socket-option trace this
20463 		 * means rates > 34Gbps won't show right, but thats probably ok.
20464 		 */
20465 		optval = (uint32_t)loptval;
20466 	} else {
20467 		error = sooptcopyin(sopt, &optval, sizeof(optval), sizeof(optval));
20468 		/* Save it in 64 bit form too */
20469 		loptval = optval;
20470 	}
20471 	if (error)
20472 		return (error);
20473 	INP_WLOCK(inp);
20474 	if (inp->inp_flags & INP_DROPPED) {
20475 		INP_WUNLOCK(inp);
20476 		return (ECONNRESET);
20477 	}
20478 	if (tp->t_fb != &__tcp_rack) {
20479 		INP_WUNLOCK(inp);
20480 		return (ENOPROTOOPT);
20481 	}
20482 	if (rack->defer_options && (rack->gp_ready == 0) &&
20483 	    (sopt->sopt_name != TCP_DEFER_OPTIONS) &&
20484 	    (sopt->sopt_name != TCP_RACK_PACING_BETA) &&
20485 	    (sopt->sopt_name != TCP_RACK_PACING_BETA_ECN) &&
20486 	    (sopt->sopt_name != TCP_RACK_MEASURE_CNT)) {
20487 		/* Options are beind deferred */
20488 		if (rack_add_deferred_option(rack, sopt->sopt_name, loptval)) {
20489 			INP_WUNLOCK(inp);
20490 			return (0);
20491 		} else {
20492 			/* No memory to defer, fail */
20493 			INP_WUNLOCK(inp);
20494 			return (ENOMEM);
20495 		}
20496 	}
20497 	error = rack_process_option(tp, rack, sopt->sopt_name, optval, loptval);
20498 	INP_WUNLOCK(inp);
20499 	return (error);
20500 }
20501 
20502 static void
20503 rack_fill_info(struct tcpcb *tp, struct tcp_info *ti)
20504 {
20505 
20506 	INP_WLOCK_ASSERT(tptoinpcb(tp));
20507 	bzero(ti, sizeof(*ti));
20508 
20509 	ti->tcpi_state = tp->t_state;
20510 	if ((tp->t_flags & TF_REQ_TSTMP) && (tp->t_flags & TF_RCVD_TSTMP))
20511 		ti->tcpi_options |= TCPI_OPT_TIMESTAMPS;
20512 	if (tp->t_flags & TF_SACK_PERMIT)
20513 		ti->tcpi_options |= TCPI_OPT_SACK;
20514 	if ((tp->t_flags & TF_REQ_SCALE) && (tp->t_flags & TF_RCVD_SCALE)) {
20515 		ti->tcpi_options |= TCPI_OPT_WSCALE;
20516 		ti->tcpi_snd_wscale = tp->snd_scale;
20517 		ti->tcpi_rcv_wscale = tp->rcv_scale;
20518 	}
20519 	if (tp->t_flags2 & (TF2_ECN_PERMIT | TF2_ACE_PERMIT))
20520 		ti->tcpi_options |= TCPI_OPT_ECN;
20521 	if (tp->t_flags & TF_FASTOPEN)
20522 		ti->tcpi_options |= TCPI_OPT_TFO;
20523 	/* still kept in ticks is t_rcvtime */
20524 	ti->tcpi_last_data_recv = ((uint32_t)ticks - tp->t_rcvtime) * tick;
20525 	/* Since we hold everything in precise useconds this is easy */
20526 	ti->tcpi_rtt = tp->t_srtt;
20527 	ti->tcpi_rttvar = tp->t_rttvar;
20528 	ti->tcpi_rto = tp->t_rxtcur;
20529 	ti->tcpi_snd_ssthresh = tp->snd_ssthresh;
20530 	ti->tcpi_snd_cwnd = tp->snd_cwnd;
20531 	/*
20532 	 * FreeBSD-specific extension fields for tcp_info.
20533 	 */
20534 	ti->tcpi_rcv_space = tp->rcv_wnd;
20535 	ti->tcpi_rcv_nxt = tp->rcv_nxt;
20536 	ti->tcpi_snd_wnd = tp->snd_wnd;
20537 	ti->tcpi_snd_bwnd = 0;		/* Unused, kept for compat. */
20538 	ti->tcpi_snd_nxt = tp->snd_nxt;
20539 	ti->tcpi_snd_mss = tp->t_maxseg;
20540 	ti->tcpi_rcv_mss = tp->t_maxseg;
20541 	ti->tcpi_snd_rexmitpack = tp->t_sndrexmitpack;
20542 	ti->tcpi_rcv_ooopack = tp->t_rcvoopack;
20543 	ti->tcpi_snd_zerowin = tp->t_sndzerowin;
20544 #ifdef NETFLIX_STATS
20545 	ti->tcpi_total_tlp = tp->t_sndtlppack;
20546 	ti->tcpi_total_tlp_bytes = tp->t_sndtlpbyte;
20547 	memcpy(&ti->tcpi_rxsyninfo, &tp->t_rxsyninfo, sizeof(struct tcpsyninfo));
20548 #endif
20549 #ifdef TCP_OFFLOAD
20550 	if (tp->t_flags & TF_TOE) {
20551 		ti->tcpi_options |= TCPI_OPT_TOE;
20552 		tcp_offload_tcp_info(tp, ti);
20553 	}
20554 #endif
20555 }
20556 
20557 static int
20558 rack_get_sockopt(struct inpcb *inp, struct sockopt *sopt)
20559 {
20560 	struct tcpcb *tp;
20561 	struct tcp_rack *rack;
20562 	int32_t error, optval;
20563 	uint64_t val, loptval;
20564 	struct	tcp_info ti;
20565 	/*
20566 	 * Because all our options are either boolean or an int, we can just
20567 	 * pull everything into optval and then unlock and copy. If we ever
20568 	 * add a option that is not a int, then this will have quite an
20569 	 * impact to this routine.
20570 	 */
20571 	error = 0;
20572 	tp = intotcpcb(inp);
20573 	rack = (struct tcp_rack *)tp->t_fb_ptr;
20574 	if (rack == NULL) {
20575 		INP_WUNLOCK(inp);
20576 		return (EINVAL);
20577 	}
20578 	switch (sopt->sopt_name) {
20579 	case TCP_INFO:
20580 		/* First get the info filled */
20581 		rack_fill_info(tp, &ti);
20582 		/* Fix up the rtt related fields if needed */
20583 		INP_WUNLOCK(inp);
20584 		error = sooptcopyout(sopt, &ti, sizeof ti);
20585 		return (error);
20586 	/*
20587 	 * Beta is the congestion control value for NewReno that influences how
20588 	 * much of a backoff happens when loss is detected. It is normally set
20589 	 * to 50 for 50% i.e. the cwnd is reduced to 50% of its previous value
20590 	 * when you exit recovery.
20591 	 */
20592 	case TCP_RACK_PACING_BETA:
20593 		if (strcmp(tp->cc_algo->name, CCALGONAME_NEWRENO) != 0)
20594 			error = EINVAL;
20595 		else if (rack->rc_pacing_cc_set == 0)
20596 			optval = rack->r_ctl.rc_saved_beta.beta;
20597 		else {
20598 			/*
20599 			 * Reach out into the CC data and report back what
20600 			 * I have previously set. Yeah it looks hackish but
20601 			 * we don't want to report the saved values.
20602 			 */
20603 			if (tp->ccv->cc_data)
20604 				optval = ((struct newreno *)tp->ccv->cc_data)->beta;
20605 			else
20606 				error = EINVAL;
20607 		}
20608 		break;
20609 		/*
20610 		 * Beta_ecn is the congestion control value for NewReno that influences how
20611 		 * much of a backoff happens when a ECN mark is detected. It is normally set
20612 		 * to 80 for 80% i.e. the cwnd is reduced by 20% of its previous value when
20613 		 * you exit recovery. Note that classic ECN has a beta of 50, it is only
20614 		 * ABE Ecn that uses this "less" value, but we do too with pacing :)
20615 		 */
20616 
20617 	case TCP_RACK_PACING_BETA_ECN:
20618 		if (strcmp(tp->cc_algo->name, CCALGONAME_NEWRENO) != 0)
20619 			error = EINVAL;
20620 		else if (rack->rc_pacing_cc_set == 0)
20621 			optval = rack->r_ctl.rc_saved_beta.beta_ecn;
20622 		else {
20623 			/*
20624 			 * Reach out into the CC data and report back what
20625 			 * I have previously set. Yeah it looks hackish but
20626 			 * we don't want to report the saved values.
20627 			 */
20628 			if (tp->ccv->cc_data)
20629 				optval = ((struct newreno *)tp->ccv->cc_data)->beta_ecn;
20630 			else
20631 				error = EINVAL;
20632 		}
20633 		break;
20634 	case TCP_RACK_DSACK_OPT:
20635 		optval = 0;
20636 		if (rack->rc_rack_tmr_std_based) {
20637 			optval |= 1;
20638 		}
20639 		if (rack->rc_rack_use_dsack) {
20640 			optval |= 2;
20641 		}
20642 		break;
20643  	case TCP_RACK_ENABLE_HYSTART:
20644 	{
20645 		if (tp->ccv->flags & CCF_HYSTART_ALLOWED) {
20646 			optval = RACK_HYSTART_ON;
20647 			if (tp->ccv->flags & CCF_HYSTART_CAN_SH_CWND)
20648 				optval = RACK_HYSTART_ON_W_SC;
20649 			if (tp->ccv->flags & CCF_HYSTART_CONS_SSTH)
20650 				optval = RACK_HYSTART_ON_W_SC_C;
20651 		} else {
20652 			optval = RACK_HYSTART_OFF;
20653 		}
20654 	}
20655 	break;
20656 	case TCP_FAST_RSM_HACK:
20657 		optval = rack->fast_rsm_hack;
20658 		break;
20659 	case TCP_DEFER_OPTIONS:
20660 		optval = rack->defer_options;
20661 		break;
20662 	case TCP_RACK_MEASURE_CNT:
20663 		optval = rack->r_ctl.req_measurements;
20664 		break;
20665 	case TCP_REC_ABC_VAL:
20666 		optval = rack->r_use_labc_for_rec;
20667 		break;
20668 	case TCP_RACK_ABC_VAL:
20669 		optval = rack->rc_labc;
20670 		break;
20671 	case TCP_HDWR_UP_ONLY:
20672 		optval= rack->r_up_only;
20673 		break;
20674 	case TCP_PACING_RATE_CAP:
20675 		loptval = rack->r_ctl.bw_rate_cap;
20676 		break;
20677 	case TCP_RACK_PROFILE:
20678 		/* You cannot retrieve a profile, its write only */
20679 		error = EINVAL;
20680 		break;
20681 	case TCP_USE_CMP_ACKS:
20682 		optval = rack->r_use_cmp_ack;
20683 		break;
20684 	case TCP_RACK_PACE_TO_FILL:
20685 		optval = rack->rc_pace_to_cwnd;
20686 		if (optval && rack->r_fill_less_agg)
20687 			optval++;
20688 		break;
20689 	case TCP_RACK_NO_PUSH_AT_MAX:
20690 		optval = rack->r_ctl.rc_no_push_at_mrtt;
20691 		break;
20692 	case TCP_SHARED_CWND_ENABLE:
20693 		optval = rack->rack_enable_scwnd;
20694 		break;
20695 	case TCP_RACK_NONRXT_CFG_RATE:
20696 		optval = rack->rack_rec_nonrxt_use_cr;
20697 		break;
20698 	case TCP_NO_PRR:
20699 		if (rack->rack_no_prr  == 1)
20700 			optval = 1;
20701 		else if (rack->no_prr_addback == 1)
20702 			optval = 2;
20703 		else
20704 			optval = 0;
20705 		break;
20706 	case TCP_RACK_DO_DETECTION:
20707 		optval = rack->do_detection;
20708 		break;
20709 	case TCP_RACK_MBUF_QUEUE:
20710 		/* Now do we use the LRO mbuf-queue feature */
20711 		optval = rack->r_mbuf_queue;
20712 		break;
20713 	case TCP_TIMELY_DYN_ADJ:
20714 		optval = rack->rc_gp_dyn_mul;
20715 		break;
20716 	case TCP_BBR_IWINTSO:
20717 		optval = rack->rc_init_win;
20718 		break;
20719 	case TCP_RACK_TLP_REDUCE:
20720 		/* RACK TLP cwnd reduction (bool) */
20721 		optval = rack->r_ctl.rc_tlp_cwnd_reduce;
20722 		break;
20723 	case TCP_BBR_RACK_INIT_RATE:
20724 		val = rack->r_ctl.init_rate;
20725 		/* convert to kbits per sec */
20726 		val *= 8;
20727 		val /= 1000;
20728 		optval = (uint32_t)val;
20729 		break;
20730 	case TCP_RACK_FORCE_MSEG:
20731 		optval = rack->rc_force_max_seg;
20732 		break;
20733 	case TCP_RACK_PACE_MAX_SEG:
20734 		/* Max segments in a pace */
20735 		optval = rack->rc_user_set_max_segs;
20736 		break;
20737 	case TCP_RACK_PACE_ALWAYS:
20738 		/* Use the always pace method */
20739 		optval = rack->rc_always_pace;
20740 		break;
20741 	case TCP_RACK_PRR_SENDALOT:
20742 		/* Allow PRR to send more than one seg */
20743 		optval = rack->r_ctl.rc_prr_sendalot;
20744 		break;
20745 	case TCP_RACK_MIN_TO:
20746 		/* Minimum time between rack t-o's in ms */
20747 		optval = rack->r_ctl.rc_min_to;
20748 		break;
20749 	case TCP_RACK_EARLY_SEG:
20750 		/* If early recovery max segments */
20751 		optval = rack->r_ctl.rc_early_recovery_segs;
20752 		break;
20753 	case TCP_RACK_REORD_THRESH:
20754 		/* RACK reorder threshold (shift amount) */
20755 		optval = rack->r_ctl.rc_reorder_shift;
20756 		break;
20757 	case TCP_RACK_REORD_FADE:
20758 		/* Does reordering fade after ms time */
20759 		optval = rack->r_ctl.rc_reorder_fade;
20760 		break;
20761 	case TCP_BBR_USE_RACK_RR:
20762 		/* Do we use the rack cheat for rxt */
20763 		optval = rack->use_rack_rr;
20764 		break;
20765 	case TCP_RACK_RR_CONF:
20766 		optval = rack->r_rr_config;
20767 		break;
20768 	case TCP_HDWR_RATE_CAP:
20769 		optval = rack->r_rack_hw_rate_caps;
20770 		break;
20771 	case TCP_BBR_HDWR_PACE:
20772 		optval = rack->rack_hdw_pace_ena;
20773 		break;
20774 	case TCP_RACK_TLP_THRESH:
20775 		/* RACK TLP theshold i.e. srtt+(srtt/N) */
20776 		optval = rack->r_ctl.rc_tlp_threshold;
20777 		break;
20778 	case TCP_RACK_PKT_DELAY:
20779 		/* RACK added ms i.e. rack-rtt + reord + N */
20780 		optval = rack->r_ctl.rc_pkt_delay;
20781 		break;
20782 	case TCP_RACK_TLP_USE:
20783 		optval = rack->rack_tlp_threshold_use;
20784 		break;
20785 	case TCP_RACK_PACE_RATE_CA:
20786 		optval = rack->r_ctl.rc_fixed_pacing_rate_ca;
20787 		break;
20788 	case TCP_RACK_PACE_RATE_SS:
20789 		optval = rack->r_ctl.rc_fixed_pacing_rate_ss;
20790 		break;
20791 	case TCP_RACK_PACE_RATE_REC:
20792 		optval = rack->r_ctl.rc_fixed_pacing_rate_rec;
20793 		break;
20794 	case TCP_RACK_GP_INCREASE_SS:
20795 		optval = rack->r_ctl.rack_per_of_gp_ca;
20796 		break;
20797 	case TCP_RACK_GP_INCREASE_CA:
20798 		optval = rack->r_ctl.rack_per_of_gp_ss;
20799 		break;
20800 	case TCP_BBR_RACK_RTT_USE:
20801 		optval = rack->r_ctl.rc_rate_sample_method;
20802 		break;
20803 	case TCP_DELACK:
20804 		optval = tp->t_delayed_ack;
20805 		break;
20806 	case TCP_DATA_AFTER_CLOSE:
20807 		optval = rack->rc_allow_data_af_clo;
20808 		break;
20809 	case TCP_SHARED_CWND_TIME_LIMIT:
20810 		optval = rack->r_limit_scw;
20811 		break;
20812 	case TCP_RACK_TIMER_SLOP:
20813 		optval = rack->r_ctl.timer_slop;
20814 		break;
20815 	default:
20816 		return (tcp_default_ctloutput(inp, sopt));
20817 		break;
20818 	}
20819 	INP_WUNLOCK(inp);
20820 	if (error == 0) {
20821 		if (TCP_PACING_RATE_CAP)
20822 			error = sooptcopyout(sopt, &loptval, sizeof loptval);
20823 		else
20824 			error = sooptcopyout(sopt, &optval, sizeof optval);
20825 	}
20826 	return (error);
20827 }
20828 
20829 static int
20830 rack_ctloutput(struct inpcb *inp, struct sockopt *sopt)
20831 {
20832 	if (sopt->sopt_dir == SOPT_SET) {
20833 		return (rack_set_sockopt(inp, sopt));
20834 	} else if (sopt->sopt_dir == SOPT_GET) {
20835 		return (rack_get_sockopt(inp, sopt));
20836 	} else {
20837 		panic("%s: sopt_dir $%d", __func__, sopt->sopt_dir);
20838 	}
20839 }
20840 
20841 static const char *rack_stack_names[] = {
20842 	__XSTRING(STACKNAME),
20843 #ifdef STACKALIAS
20844 	__XSTRING(STACKALIAS),
20845 #endif
20846 };
20847 
20848 static int
20849 rack_ctor(void *mem, int32_t size, void *arg, int32_t how)
20850 {
20851 	memset(mem, 0, size);
20852 	return (0);
20853 }
20854 
20855 static void
20856 rack_dtor(void *mem, int32_t size, void *arg)
20857 {
20858 
20859 }
20860 
20861 static bool rack_mod_inited = false;
20862 
20863 static int
20864 tcp_addrack(module_t mod, int32_t type, void *data)
20865 {
20866 	int32_t err = 0;
20867 	int num_stacks;
20868 
20869 	switch (type) {
20870 	case MOD_LOAD:
20871 		rack_zone = uma_zcreate(__XSTRING(MODNAME) "_map",
20872 		    sizeof(struct rack_sendmap),
20873 		    rack_ctor, rack_dtor, NULL, NULL, UMA_ALIGN_PTR, 0);
20874 
20875 		rack_pcb_zone = uma_zcreate(__XSTRING(MODNAME) "_pcb",
20876 		    sizeof(struct tcp_rack),
20877 		    rack_ctor, NULL, NULL, NULL, UMA_ALIGN_CACHE, 0);
20878 
20879 		sysctl_ctx_init(&rack_sysctl_ctx);
20880 		rack_sysctl_root = SYSCTL_ADD_NODE(&rack_sysctl_ctx,
20881 		    SYSCTL_STATIC_CHILDREN(_net_inet_tcp),
20882 		    OID_AUTO,
20883 #ifdef STACKALIAS
20884 		    __XSTRING(STACKALIAS),
20885 #else
20886 		    __XSTRING(STACKNAME),
20887 #endif
20888 		    CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
20889 		    "");
20890 		if (rack_sysctl_root == NULL) {
20891 			printf("Failed to add sysctl node\n");
20892 			err = EFAULT;
20893 			goto free_uma;
20894 		}
20895 		rack_init_sysctls();
20896 		num_stacks = nitems(rack_stack_names);
20897 		err = register_tcp_functions_as_names(&__tcp_rack, M_WAITOK,
20898 		    rack_stack_names, &num_stacks);
20899 		if (err) {
20900 			printf("Failed to register %s stack name for "
20901 			    "%s module\n", rack_stack_names[num_stacks],
20902 			    __XSTRING(MODNAME));
20903 			sysctl_ctx_free(&rack_sysctl_ctx);
20904 free_uma:
20905 			uma_zdestroy(rack_zone);
20906 			uma_zdestroy(rack_pcb_zone);
20907 			rack_counter_destroy();
20908 			printf("Failed to register rack module -- err:%d\n", err);
20909 			return (err);
20910 		}
20911 		tcp_lro_reg_mbufq();
20912 		rack_mod_inited = true;
20913 		break;
20914 	case MOD_QUIESCE:
20915 		err = deregister_tcp_functions(&__tcp_rack, true, false);
20916 		break;
20917 	case MOD_UNLOAD:
20918 		err = deregister_tcp_functions(&__tcp_rack, false, true);
20919 		if (err == EBUSY)
20920 			break;
20921 		if (rack_mod_inited) {
20922 			uma_zdestroy(rack_zone);
20923 			uma_zdestroy(rack_pcb_zone);
20924 			sysctl_ctx_free(&rack_sysctl_ctx);
20925 			rack_counter_destroy();
20926 			rack_mod_inited = false;
20927 		}
20928 		tcp_lro_dereg_mbufq();
20929 		err = 0;
20930 		break;
20931 	default:
20932 		return (EOPNOTSUPP);
20933 	}
20934 	return (err);
20935 }
20936 
20937 static moduledata_t tcp_rack = {
20938 	.name = __XSTRING(MODNAME),
20939 	.evhand = tcp_addrack,
20940 	.priv = 0
20941 };
20942 
20943 MODULE_VERSION(MODNAME, 1);
20944 DECLARE_MODULE(MODNAME, tcp_rack, SI_SUB_PROTO_DOMAIN, SI_ORDER_ANY);
20945 MODULE_DEPEND(MODNAME, tcphpts, 1, 1, 1);
20946