xref: /freebsd/sys/netinet/tcp_stacks/rack.c (revision 6312d144613f97bf59703c442ee4871be1450c46) 
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_hpts.h>
97 #include <netinet/tcp_ratelimit.h>
98 #include <netinet/tcp_accounting.h>
99 #include <netinet/tcpip.h>
100 #include <netinet/cc/cc.h>
101 #include <netinet/cc/cc_newreno.h>
102 #include <netinet/tcp_fastopen.h>
103 #include <netinet/tcp_lro.h>
104 #ifdef NETFLIX_SHARED_CWND
105 #include <netinet/tcp_shared_cwnd.h>
106 #endif
107 #ifdef TCPDEBUG
108 #include <netinet/tcp_debug.h>
109 #endif				/* TCPDEBUG */
110 #ifdef TCP_OFFLOAD
111 #include <netinet/tcp_offload.h>
112 #endif
113 #ifdef INET6
114 #include <netinet6/tcp6_var.h>
115 #endif
116 
117 #include <netipsec/ipsec_support.h>
118 
119 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
120 #include <netipsec/ipsec.h>
121 #include <netipsec/ipsec6.h>
122 #endif				/* IPSEC */
123 
124 #include <netinet/udp.h>
125 #include <netinet/udp_var.h>
126 #include <machine/in_cksum.h>
127 
128 #ifdef MAC
129 #include <security/mac/mac_framework.h>
130 #endif
131 #include "sack_filter.h"
132 #include "tcp_rack.h"
133 #include "rack_bbr_common.h"
134 
135 uma_zone_t rack_zone;
136 uma_zone_t rack_pcb_zone;
137 
138 #ifndef TICKS2SBT
139 #define	TICKS2SBT(__t)	(tick_sbt * ((sbintime_t)(__t)))
140 #endif
141 
142 VNET_DECLARE(uint32_t, newreno_beta);
143 VNET_DECLARE(uint32_t, newreno_beta_ecn);
144 #define V_newreno_beta VNET(newreno_beta)
145 #define V_newreno_beta_ecn VNET(newreno_beta_ecn)
146 
147 
148 MALLOC_DEFINE(M_TCPFSB, "tcp_fsb", "TCP fast send block");
149 MALLOC_DEFINE(M_TCPDO, "tcp_do", "TCP deferred options");
150 
151 struct sysctl_ctx_list rack_sysctl_ctx;
152 struct sysctl_oid *rack_sysctl_root;
153 
154 #define CUM_ACKED 1
155 #define SACKED 2
156 
157 /*
158  * The RACK module incorporates a number of
159  * TCP ideas that have been put out into the IETF
160  * over the last few years:
161  * - Matt Mathis's Rate Halving which slowly drops
162  *    the congestion window so that the ack clock can
163  *    be maintained during a recovery.
164  * - Yuchung Cheng's RACK TCP (for which its named) that
165  *    will stop us using the number of dup acks and instead
166  *    use time as the gage of when we retransmit.
167  * - Reorder Detection of RFC4737 and the Tail-Loss probe draft
168  *    of Dukkipati et.al.
169  * RACK depends on SACK, so if an endpoint arrives that
170  * cannot do SACK the state machine below will shuttle the
171  * connection back to using the "default" TCP stack that is
172  * in FreeBSD.
173  *
174  * To implement RACK the original TCP stack was first decomposed
175  * into a functional state machine with individual states
176  * for each of the possible TCP connection states. The do_segement
177  * functions role in life is to mandate the connection supports SACK
178  * initially and then assure that the RACK state matches the conenction
179  * state before calling the states do_segment function. Each
180  * state is simplified due to the fact that the original do_segment
181  * has been decomposed and we *know* what state we are in (no
182  * switches on the state) and all tests for SACK are gone. This
183  * greatly simplifies what each state does.
184  *
185  * TCP output is also over-written with a new version since it
186  * must maintain the new rack scoreboard.
187  *
188  */
189 static int32_t rack_tlp_thresh = 1;
190 static int32_t rack_tlp_limit = 2;	/* No more than 2 TLPs w-out new data */
191 static int32_t rack_tlp_use_greater = 1;
192 static int32_t rack_reorder_thresh = 2;
193 static int32_t rack_reorder_fade = 60000000;	/* 0 - never fade, def 60,000,000
194 						 * - 60 seconds */
195 static uint8_t rack_req_measurements = 1;
196 /* Attack threshold detections */
197 static uint32_t rack_highest_sack_thresh_seen = 0;
198 static uint32_t rack_highest_move_thresh_seen = 0;
199 static int32_t rack_enable_hw_pacing = 0; /* Due to CCSP keep it off by default */
200 static int32_t rack_hw_pace_extra_slots = 2;	/* 2 extra MSS time betweens */
201 static int32_t rack_hw_rate_caps = 1; /* 1; */
202 static int32_t rack_hw_rate_min = 0; /* 1500000;*/
203 static int32_t rack_hw_rate_to_low = 0; /* 1200000; */
204 static int32_t rack_hw_up_only = 1;
205 static int32_t rack_stats_gets_ms_rtt = 1;
206 static int32_t rack_prr_addbackmax = 2;
207 static int32_t rack_do_hystart = 0;
208 
209 static int32_t rack_pkt_delay = 1000;
210 static int32_t rack_send_a_lot_in_prr = 1;
211 static int32_t rack_min_to = 1000;	/* Number of microsecond  min timeout */
212 static int32_t rack_verbose_logging = 0;
213 static int32_t rack_ignore_data_after_close = 1;
214 static int32_t rack_enable_shared_cwnd = 1;
215 static int32_t rack_use_cmp_acks = 1;
216 static int32_t rack_use_fsb = 1;
217 static int32_t rack_use_rfo = 1;
218 static int32_t rack_use_rsm_rfo = 1;
219 static int32_t rack_max_abc_post_recovery = 2;
220 static int32_t rack_client_low_buf = 0;
221 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 */
222 #ifdef TCP_ACCOUNTING
223 static int32_t rack_tcp_accounting = 0;
224 #endif
225 static int32_t rack_limits_scwnd = 1;
226 static int32_t rack_enable_mqueue_for_nonpaced = 0;
227 static int32_t rack_disable_prr = 0;
228 static int32_t use_rack_rr = 1;
229 static int32_t rack_non_rxt_use_cr = 0; /* does a non-rxt in recovery use the configured rate (ss/ca)? */
230 static int32_t rack_persist_min = 250000;	/* 250usec */
231 static int32_t rack_persist_max = 2000000;	/* 2 Second in usec's */
232 static int32_t rack_sack_not_required = 1;	/* set to one to allow non-sack to use rack */
233 static int32_t rack_default_init_window = 0;	/* Use system default */
234 static int32_t rack_limit_time_with_srtt = 0;
235 static int32_t rack_autosndbuf_inc = 20;	/* In percentage form */
236 static int32_t rack_enobuf_hw_boost_mult = 2;	/* How many times the hw rate we boost slot using time_between */
237 static int32_t rack_enobuf_hw_max = 12000;	/* 12 ms in usecs */
238 static int32_t rack_enobuf_hw_min = 10000;	/* 10 ms in usecs */
239 static int32_t rack_hw_rwnd_factor = 2;		/* How many max_segs the rwnd must be before we hold off sending */
240 /*
241  * Currently regular tcp has a rto_min of 30ms
242  * the backoff goes 12 times so that ends up
243  * being a total of 122.850 seconds before a
244  * connection is killed.
245  */
246 static uint32_t rack_def_data_window = 20;
247 static uint32_t rack_goal_bdp = 2;
248 static uint32_t rack_min_srtts = 1;
249 static uint32_t rack_min_measure_usec = 0;
250 static int32_t rack_tlp_min = 10000;	/* 10ms */
251 static int32_t rack_rto_min = 30000;	/* 30,000 usec same as main freebsd */
252 static int32_t rack_rto_max = 4000000;	/* 4 seconds in usec's */
253 static const int32_t rack_free_cache = 2;
254 static int32_t rack_hptsi_segments = 40;
255 static int32_t rack_rate_sample_method = USE_RTT_LOW;
256 static int32_t rack_pace_every_seg = 0;
257 static int32_t rack_delayed_ack_time = 40000;	/* 40ms in usecs */
258 static int32_t rack_slot_reduction = 4;
259 static int32_t rack_wma_divisor = 8;		/* For WMA calculation */
260 static int32_t rack_cwnd_block_ends_measure = 0;
261 static int32_t rack_rwnd_block_ends_measure = 0;
262 static int32_t rack_def_profile = 0;
263 
264 static int32_t rack_lower_cwnd_at_tlp = 0;
265 static int32_t rack_limited_retran = 0;
266 static int32_t rack_always_send_oldest = 0;
267 static int32_t rack_tlp_threshold_use = TLP_USE_TWO_ONE;
268 
269 static uint16_t rack_per_of_gp_ss = 250;	/* 250 % slow-start */
270 static uint16_t rack_per_of_gp_ca = 200;	/* 200 % congestion-avoidance */
271 static uint16_t rack_per_of_gp_rec = 200;	/* 200 % of bw */
272 
273 /* Probertt */
274 static uint16_t rack_per_of_gp_probertt = 60;	/* 60% of bw */
275 static uint16_t rack_per_of_gp_lowthresh = 40;	/* 40% is bottom */
276 static uint16_t rack_per_of_gp_probertt_reduce = 10; /* 10% reduction */
277 static uint16_t rack_atexit_prtt_hbp = 130;	/* Clamp to 130% on exit prtt if highly buffered path */
278 static uint16_t rack_atexit_prtt = 130;	/* Clamp to 100% on exit prtt if non highly buffered path */
279 
280 static uint32_t rack_max_drain_wait = 2;	/* How man gp srtt's before we give up draining */
281 static uint32_t rack_must_drain = 1;		/* How many GP srtt's we *must* wait */
282 static uint32_t rack_probertt_use_min_rtt_entry = 1;	/* Use the min to calculate the goal else gp_srtt */
283 static uint32_t rack_probertt_use_min_rtt_exit = 0;
284 static uint32_t rack_probe_rtt_sets_cwnd = 0;
285 static uint32_t rack_probe_rtt_safety_val = 2000000;	/* No more than 2 sec in probe-rtt */
286 static uint32_t rack_time_between_probertt = 9600000;	/* 9.6 sec in usecs */
287 static uint32_t rack_probertt_gpsrtt_cnt_mul = 0;	/* How many srtt periods does probe-rtt last top fraction */
288 static uint32_t rack_probertt_gpsrtt_cnt_div = 0;	/* How many srtt periods does probe-rtt last bottom fraction */
289 static uint32_t rack_min_probertt_hold = 40000;		/* Equal to delayed ack time */
290 static uint32_t rack_probertt_filter_life = 10000000;
291 static uint32_t rack_probertt_lower_within = 10;
292 static uint32_t rack_min_rtt_movement = 250000;	/* Must move at least 250ms (in microseconds)  to count as a lowering */
293 static int32_t rack_pace_one_seg = 0;		/* Shall we pace for less than 1.4Meg 1MSS at a time */
294 static int32_t rack_probertt_clear_is = 1;
295 static int32_t rack_max_drain_hbp = 1;		/* Extra drain times gpsrtt for highly buffered paths */
296 static int32_t rack_hbp_thresh = 3;		/* what is the divisor max_rtt/min_rtt to decided a hbp */
297 
298 /* Part of pacing */
299 static int32_t rack_max_per_above = 30;		/* When we go to increment stop if above 100+this% */
300 
301 /* Timely information */
302 /* Combine these two gives the range of 'no change' to bw */
303 /* ie the up/down provide the upper and lower bound */
304 static int32_t rack_gp_per_bw_mul_up = 2;	/* 2% */
305 static int32_t rack_gp_per_bw_mul_down = 4;	/* 4% */
306 static int32_t rack_gp_rtt_maxmul = 3;		/* 3 x maxmin */
307 static int32_t rack_gp_rtt_minmul = 1;		/* minrtt + (minrtt/mindiv) is lower rtt */
308 static int32_t rack_gp_rtt_mindiv = 4;		/* minrtt + (minrtt * minmul/mindiv) is lower rtt */
309 static int32_t rack_gp_decrease_per = 20;	/* 20% decrease in multipler */
310 static int32_t rack_gp_increase_per = 2;	/* 2% increase in multipler */
311 static int32_t rack_per_lower_bound = 50;	/* Don't allow to drop below this multiplier */
312 static int32_t rack_per_upper_bound_ss = 0;	/* Don't allow SS to grow above this */
313 static int32_t rack_per_upper_bound_ca = 0;	/* Don't allow CA to grow above this */
314 static int32_t rack_do_dyn_mul = 0;		/* Are the rack gp multipliers dynamic */
315 static int32_t rack_gp_no_rec_chg = 1;		/* Prohibit recovery from reducing it's multiplier */
316 static int32_t rack_timely_dec_clear = 6;	/* Do we clear decrement count at a value (6)? */
317 static int32_t rack_timely_max_push_rise = 3;	/* One round of pushing */
318 static int32_t rack_timely_max_push_drop = 3;	/* Three round of pushing */
319 static int32_t rack_timely_min_segs = 4;	/* 4 segment minimum */
320 static int32_t rack_use_max_for_nobackoff = 0;
321 static int32_t rack_timely_int_timely_only = 0;	/* do interim timely's only use the timely algo (no b/w changes)? */
322 static int32_t rack_timely_no_stopping = 0;
323 static int32_t rack_down_raise_thresh = 100;
324 static int32_t rack_req_segs = 1;
325 static uint64_t rack_bw_rate_cap = 0;
326 
327 /* Weird delayed ack mode */
328 static int32_t rack_use_imac_dack = 0;
329 /* Rack specific counters */
330 counter_u64_t rack_badfr;
331 counter_u64_t rack_badfr_bytes;
332 counter_u64_t rack_rtm_prr_retran;
333 counter_u64_t rack_rtm_prr_newdata;
334 counter_u64_t rack_timestamp_mismatch;
335 counter_u64_t rack_reorder_seen;
336 counter_u64_t rack_paced_segments;
337 counter_u64_t rack_unpaced_segments;
338 counter_u64_t rack_calc_zero;
339 counter_u64_t rack_calc_nonzero;
340 counter_u64_t rack_saw_enobuf;
341 counter_u64_t rack_saw_enobuf_hw;
342 counter_u64_t rack_saw_enetunreach;
343 counter_u64_t rack_per_timer_hole;
344 counter_u64_t rack_large_ackcmp;
345 counter_u64_t rack_small_ackcmp;
346 #ifdef INVARIANTS
347 counter_u64_t rack_adjust_map_bw;
348 #endif
349 /* Tail loss probe counters */
350 counter_u64_t rack_tlp_tot;
351 counter_u64_t rack_tlp_newdata;
352 counter_u64_t rack_tlp_retran;
353 counter_u64_t rack_tlp_retran_bytes;
354 counter_u64_t rack_tlp_retran_fail;
355 counter_u64_t rack_to_tot;
356 counter_u64_t rack_to_arm_rack;
357 counter_u64_t rack_to_arm_tlp;
358 counter_u64_t rack_hot_alloc;
359 counter_u64_t rack_to_alloc;
360 counter_u64_t rack_to_alloc_hard;
361 counter_u64_t rack_to_alloc_emerg;
362 counter_u64_t rack_to_alloc_limited;
363 counter_u64_t rack_alloc_limited_conns;
364 counter_u64_t rack_split_limited;
365 
366 #define MAX_NUM_OF_CNTS 13
367 counter_u64_t rack_proc_comp_ack[MAX_NUM_OF_CNTS];
368 counter_u64_t rack_multi_single_eq;
369 counter_u64_t rack_proc_non_comp_ack;
370 
371 counter_u64_t rack_fto_send;
372 counter_u64_t rack_fto_rsm_send;
373 counter_u64_t rack_nfto_resend;
374 counter_u64_t rack_non_fto_send;
375 counter_u64_t rack_extended_rfo;
376 
377 counter_u64_t rack_sack_proc_all;
378 counter_u64_t rack_sack_proc_short;
379 counter_u64_t rack_sack_proc_restart;
380 counter_u64_t rack_sack_attacks_detected;
381 counter_u64_t rack_sack_attacks_reversed;
382 counter_u64_t rack_sack_used_next_merge;
383 counter_u64_t rack_sack_splits;
384 counter_u64_t rack_sack_used_prev_merge;
385 counter_u64_t rack_sack_skipped_acked;
386 counter_u64_t rack_ack_total;
387 counter_u64_t rack_express_sack;
388 counter_u64_t rack_sack_total;
389 counter_u64_t rack_move_none;
390 counter_u64_t rack_move_some;
391 
392 counter_u64_t rack_used_tlpmethod;
393 counter_u64_t rack_used_tlpmethod2;
394 counter_u64_t rack_enter_tlp_calc;
395 counter_u64_t rack_input_idle_reduces;
396 counter_u64_t rack_collapsed_win;
397 counter_u64_t rack_tlp_does_nada;
398 counter_u64_t rack_try_scwnd;
399 counter_u64_t rack_hw_pace_init_fail;
400 counter_u64_t rack_hw_pace_lost;
401 counter_u64_t rack_sbsndptr_right;
402 counter_u64_t rack_sbsndptr_wrong;
403 
404 /* Temp CPU counters */
405 counter_u64_t rack_find_high;
406 
407 counter_u64_t rack_progress_drops;
408 counter_u64_t rack_out_size[TCP_MSS_ACCT_SIZE];
409 counter_u64_t rack_opts_arry[RACK_OPTS_SIZE];
410 
411 
412 #define	RACK_REXMTVAL(tp) max(rack_rto_min, ((tp)->t_srtt + ((tp)->t_rttvar << 2)))
413 
414 #define	RACK_TCPT_RANGESET(tv, value, tvmin, tvmax, slop) do {	\
415 	(tv) = (value) + slop;	 \
416 	if ((u_long)(tv) < (u_long)(tvmin)) \
417 		(tv) = (tvmin); \
418 	if ((u_long)(tv) > (u_long)(tvmax)) \
419 		(tv) = (tvmax); \
420 } while (0)
421 
422 static void
423 rack_log_progress_event(struct tcp_rack *rack, struct tcpcb *tp, uint32_t tick,  int event, int line);
424 
425 static int
426 rack_process_ack(struct mbuf *m, struct tcphdr *th,
427     struct socket *so, struct tcpcb *tp, struct tcpopt *to,
428     uint32_t tiwin, int32_t tlen, int32_t * ofia, int32_t thflags, int32_t * ret_val);
429 static int
430 rack_process_data(struct mbuf *m, struct tcphdr *th,
431     struct socket *so, struct tcpcb *tp, int32_t drop_hdrlen, int32_t tlen,
432     uint32_t tiwin, int32_t thflags, int32_t nxt_pkt);
433 static void
434 rack_ack_received(struct tcpcb *tp, struct tcp_rack *rack,
435    uint32_t th_ack, uint16_t nsegs, uint16_t type, int32_t recovery);
436 static struct rack_sendmap *rack_alloc(struct tcp_rack *rack);
437 static struct rack_sendmap *rack_alloc_limit(struct tcp_rack *rack,
438     uint8_t limit_type);
439 static struct rack_sendmap *
440 rack_check_recovery_mode(struct tcpcb *tp,
441     uint32_t tsused);
442 static void
443 rack_cong_signal(struct tcpcb *tp,
444 		 uint32_t type, uint32_t ack);
445 static void rack_counter_destroy(void);
446 static int
447 rack_ctloutput(struct socket *so, struct sockopt *sopt,
448     struct inpcb *inp, struct tcpcb *tp);
449 static int32_t rack_ctor(void *mem, int32_t size, void *arg, int32_t how);
450 static void
451 rack_set_pace_segments(struct tcpcb *tp, struct tcp_rack *rack, uint32_t line, uint64_t *fill_override);
452 static void
453 rack_do_segment(struct mbuf *m, struct tcphdr *th,
454     struct socket *so, struct tcpcb *tp, int32_t drop_hdrlen, int32_t tlen,
455     uint8_t iptos);
456 static void rack_dtor(void *mem, int32_t size, void *arg);
457 static void
458 rack_log_alt_to_to_cancel(struct tcp_rack *rack,
459     uint32_t flex1, uint32_t flex2,
460     uint32_t flex3, uint32_t flex4,
461     uint32_t flex5, uint32_t flex6,
462     uint16_t flex7, uint8_t mod);
463 
464 static void
465 rack_log_pacing_delay_calc(struct tcp_rack *rack, uint32_t len, uint32_t slot,
466    uint64_t bw_est, uint64_t bw, uint64_t len_time, int method, int line,
467    struct rack_sendmap *rsm, uint8_t quality);
468 static struct rack_sendmap *
469 rack_find_high_nonack(struct tcp_rack *rack,
470     struct rack_sendmap *rsm);
471 static struct rack_sendmap *rack_find_lowest_rsm(struct tcp_rack *rack);
472 static void rack_free(struct tcp_rack *rack, struct rack_sendmap *rsm);
473 static void rack_fini(struct tcpcb *tp, int32_t tcb_is_purged);
474 static int
475 rack_get_sockopt(struct socket *so, struct sockopt *sopt,
476     struct inpcb *inp, struct tcpcb *tp, struct tcp_rack *rack);
477 static void
478 rack_do_goodput_measurement(struct tcpcb *tp, struct tcp_rack *rack,
479 			    tcp_seq th_ack, int line, uint8_t quality);
480 static uint32_t
481 rack_get_pacing_len(struct tcp_rack *rack, uint64_t bw, uint32_t mss);
482 static int32_t rack_handoff_ok(struct tcpcb *tp);
483 static int32_t rack_init(struct tcpcb *tp);
484 static void rack_init_sysctls(void);
485 static void
486 rack_log_ack(struct tcpcb *tp, struct tcpopt *to,
487     struct tcphdr *th, int entered_rec, int dup_ack_struck);
488 static void
489 rack_log_output(struct tcpcb *tp, struct tcpopt *to, int32_t len,
490     uint32_t seq_out, uint8_t th_flags, int32_t err, uint64_t ts,
491     struct rack_sendmap *hintrsm, uint16_t add_flags, struct mbuf *s_mb, uint32_t s_moff, int hw_tls);
492 
493 static void
494 rack_log_sack_passed(struct tcpcb *tp, struct tcp_rack *rack,
495     struct rack_sendmap *rsm);
496 static void rack_log_to_event(struct tcp_rack *rack, int32_t to_num, struct rack_sendmap *rsm);
497 static int32_t rack_output(struct tcpcb *tp);
498 
499 static uint32_t
500 rack_proc_sack_blk(struct tcpcb *tp, struct tcp_rack *rack,
501     struct sackblk *sack, struct tcpopt *to, struct rack_sendmap **prsm,
502     uint32_t cts, int *moved_two);
503 static void rack_post_recovery(struct tcpcb *tp, uint32_t th_seq);
504 static void rack_remxt_tmr(struct tcpcb *tp);
505 static int
506 rack_set_sockopt(struct socket *so, struct sockopt *sopt,
507     struct inpcb *inp, struct tcpcb *tp, struct tcp_rack *rack);
508 static void rack_set_state(struct tcpcb *tp, struct tcp_rack *rack);
509 static int32_t rack_stopall(struct tcpcb *tp);
510 static void
511 rack_timer_activate(struct tcpcb *tp, uint32_t timer_type,
512     uint32_t delta);
513 static int32_t rack_timer_active(struct tcpcb *tp, uint32_t timer_type);
514 static void rack_timer_cancel(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cts, int line);
515 static void rack_timer_stop(struct tcpcb *tp, uint32_t timer_type);
516 static uint32_t
517 rack_update_entry(struct tcpcb *tp, struct tcp_rack *rack,
518     struct rack_sendmap *rsm, uint64_t ts, int32_t * lenp, uint16_t add_flag);
519 static void
520 rack_update_rsm(struct tcpcb *tp, struct tcp_rack *rack,
521     struct rack_sendmap *rsm, uint64_t ts, uint16_t add_flag);
522 static int
523 rack_update_rtt(struct tcpcb *tp, struct tcp_rack *rack,
524     struct rack_sendmap *rsm, struct tcpopt *to, uint32_t cts, int32_t ack_type, tcp_seq th_ack);
525 static int32_t tcp_addrack(module_t mod, int32_t type, void *data);
526 static int
527 rack_do_close_wait(struct mbuf *m, struct tcphdr *th,
528     struct socket *so, struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen,
529     int32_t tlen, uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos);
530 static int
531 rack_do_closing(struct mbuf *m, struct tcphdr *th,
532     struct socket *so, struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen,
533     int32_t tlen, uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos);
534 static int
535 rack_do_established(struct mbuf *m, struct tcphdr *th,
536     struct socket *so, struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen,
537     int32_t tlen, uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos);
538 static int
539 rack_do_fastnewdata(struct mbuf *m, struct tcphdr *th,
540     struct socket *so, struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen,
541     int32_t tlen, uint32_t tiwin, int32_t nxt_pkt, uint8_t iptos);
542 static int
543 rack_do_fin_wait_1(struct mbuf *m, struct tcphdr *th,
544     struct socket *so, struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen,
545     int32_t tlen, uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos);
546 static int
547 rack_do_fin_wait_2(struct mbuf *m, struct tcphdr *th,
548     struct socket *so, struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen,
549     int32_t tlen, uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos);
550 static int
551 rack_do_lastack(struct mbuf *m, struct tcphdr *th,
552     struct socket *so, struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen,
553     int32_t tlen, uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos);
554 static int
555 rack_do_syn_recv(struct mbuf *m, struct tcphdr *th,
556     struct socket *so, struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen,
557     int32_t tlen, uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos);
558 static int
559 rack_do_syn_sent(struct mbuf *m, struct tcphdr *th,
560     struct socket *so, struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen,
561     int32_t tlen, uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos);
562 struct rack_sendmap *
563 tcp_rack_output(struct tcpcb *tp, struct tcp_rack *rack,
564     uint32_t tsused);
565 static void tcp_rack_xmit_timer(struct tcp_rack *rack, int32_t rtt,
566     uint32_t len, uint32_t us_tim, int confidence, struct rack_sendmap *rsm, uint16_t rtrcnt);
567 static void
568      tcp_rack_partialack(struct tcpcb *tp);
569 static int
570 rack_set_profile(struct tcp_rack *rack, int prof);
571 static void
572 rack_apply_deferred_options(struct tcp_rack *rack);
573 
574 int32_t rack_clear_counter=0;
575 
576 static void
577 rack_set_cc_pacing(struct tcp_rack *rack)
578 {
579 	struct sockopt sopt;
580 	struct cc_newreno_opts opt;
581 	struct newreno old, *ptr;
582 	struct tcpcb *tp;
583 	int error;
584 
585 	if (rack->rc_pacing_cc_set)
586 		return;
587 
588 	tp = rack->rc_tp;
589 	if (tp->cc_algo == NULL) {
590 		/* Tcb is leaving */
591 		printf("No cc algorithm?\n");
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 		printf("no ctl_output for algo:%s\n", tp->cc_algo->name);
603 		goto out;
604 	}
605 	if (ptr == NULL) {
606 		/* Just the default values */
607 		old.beta = V_newreno_beta_ecn;
608 		old.beta_ecn = V_newreno_beta_ecn;
609 		old.newreno_flags = 0;
610 	} else {
611 		old.beta = ptr->beta;
612 		old.beta_ecn = ptr->beta_ecn;
613 		old.newreno_flags = ptr->newreno_flags;
614 	}
615 	sopt.sopt_valsize = sizeof(struct cc_newreno_opts);
616 	sopt.sopt_dir = SOPT_SET;
617 	opt.name = CC_NEWRENO_BETA;
618 	opt.val = rack->r_ctl.rc_saved_beta.beta;
619 	error = CC_ALGO(tp)->ctl_output(tp->ccv, &sopt, &opt);
620 	if (error)  {
621 		printf("Error returned by ctl_output %d\n", error);
622 		goto out;
623 	}
624 	/*
625 	 * Hack alert we need to set in our newreno_flags
626 	 * so that Abe behavior is also applied.
627 	 */
628 	((struct newreno *)tp->ccv->cc_data)->newreno_flags |= CC_NEWRENO_BETA_ECN_ENABLED;
629 	opt.name = CC_NEWRENO_BETA_ECN;
630 	opt.val = rack->r_ctl.rc_saved_beta.beta_ecn;
631 	error = CC_ALGO(tp)->ctl_output(tp->ccv, &sopt, &opt);
632 	if (error) {
633 		printf("Error returned by ctl_output %d\n", error);
634 		goto out;
635 	}
636 	/* Save off the original values for restoral */
637 	memcpy(&rack->r_ctl.rc_saved_beta, &old, sizeof(struct newreno));
638 out:
639 	if (rack_verbose_logging && (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF)) {
640 		union tcp_log_stackspecific log;
641 		struct timeval tv;
642 
643 		ptr = ((struct newreno *)tp->ccv->cc_data);
644 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
645 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
646 		if (ptr) {
647 			log.u_bbr.flex1 = ptr->beta;
648 			log.u_bbr.flex2 = ptr->beta_ecn;
649 			log.u_bbr.flex3 = ptr->newreno_flags;
650 		}
651 		log.u_bbr.flex4 = rack->r_ctl.rc_saved_beta.beta;
652 		log.u_bbr.flex5 = rack->r_ctl.rc_saved_beta.beta_ecn;
653 		log.u_bbr.flex6 = rack->r_ctl.rc_saved_beta.newreno_flags;
654 		log.u_bbr.flex7 = rack->gp_ready;
655 		log.u_bbr.flex7 <<= 1;
656 		log.u_bbr.flex7 |= rack->use_fixed_rate;
657 		log.u_bbr.flex7 <<= 1;
658 		log.u_bbr.flex7 |= rack->rc_pacing_cc_set;
659 		log.u_bbr.pkts_out = rack->r_ctl.rc_prr_sndcnt;
660 		log.u_bbr.flex8 = 3;
661 		tcp_log_event_(tp, NULL, NULL, NULL, BBR_LOG_CWND, error,
662 			       0, &log, false, NULL, NULL, 0, &tv);
663 	}
664 }
665 
666 static void
667 rack_undo_cc_pacing(struct tcp_rack *rack)
668 {
669 	struct newreno old, *ptr;
670 	struct tcpcb *tp;
671 
672 	if (rack->rc_pacing_cc_set == 0)
673 		return;
674 	tp = rack->rc_tp;
675 	rack->rc_pacing_cc_set = 0;
676 	if (tp->cc_algo == NULL)
677 		/* Tcb is leaving */
678 		return;
679 	if (strcmp(tp->cc_algo->name, CCALGONAME_NEWRENO) != 0) {
680 		/* Not new-reno nothing to do! */
681 		return;
682 	}
683 	ptr = ((struct newreno *)tp->ccv->cc_data);
684 	if (ptr == NULL) {
685 		/*
686 		 * This happens at rack_fini() if the
687 		 * cc module gets freed on us. In that
688 		 * case we loose our "new" settings but
689 		 * thats ok, since the tcb is going away anyway.
690 		 */
691 		return;
692 	}
693 	/* Grab out our set values */
694 	memcpy(&old, ptr, sizeof(struct newreno));
695 	/* Copy back in the original values */
696 	memcpy(ptr, &rack->r_ctl.rc_saved_beta, sizeof(struct newreno));
697 	/* Now save back the values we had set in (for when pacing is restored) */
698 	memcpy(&rack->r_ctl.rc_saved_beta, &old, sizeof(struct newreno));
699 	if (rack_verbose_logging && (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF)) {
700 		union tcp_log_stackspecific log;
701 		struct timeval tv;
702 
703 		ptr = ((struct newreno *)tp->ccv->cc_data);
704 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
705 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
706 		log.u_bbr.flex1 = ptr->beta;
707 		log.u_bbr.flex2 = ptr->beta_ecn;
708 		log.u_bbr.flex3 = ptr->newreno_flags;
709 		log.u_bbr.flex4 = rack->r_ctl.rc_saved_beta.beta;
710 		log.u_bbr.flex5 = rack->r_ctl.rc_saved_beta.beta_ecn;
711 		log.u_bbr.flex6 = rack->r_ctl.rc_saved_beta.newreno_flags;
712 		log.u_bbr.flex7 = rack->gp_ready;
713 		log.u_bbr.flex7 <<= 1;
714 		log.u_bbr.flex7 |= rack->use_fixed_rate;
715 		log.u_bbr.flex7 <<= 1;
716 		log.u_bbr.flex7 |= rack->rc_pacing_cc_set;
717 		log.u_bbr.pkts_out = rack->r_ctl.rc_prr_sndcnt;
718 		log.u_bbr.flex8 = 4;
719 		tcp_log_event_(tp, NULL, NULL, NULL, BBR_LOG_CWND, 0,
720 			       0, &log, false, NULL, NULL, 0, &tv);
721 	}
722 }
723 
724 #ifdef NETFLIX_PEAKRATE
725 static inline void
726 rack_update_peakrate_thr(struct tcpcb *tp)
727 {
728 	/* Keep in mind that t_maxpeakrate is in B/s. */
729 	uint64_t peak;
730 	peak = uqmax((tp->t_maxseg * 2),
731 		     (((uint64_t)tp->t_maxpeakrate * (uint64_t)(tp->t_srtt)) / (uint64_t)HPTS_USEC_IN_SEC));
732 	tp->t_peakrate_thr = (uint32_t)uqmin(peak, UINT32_MAX);
733 }
734 #endif
735 
736 static int
737 sysctl_rack_clear(SYSCTL_HANDLER_ARGS)
738 {
739 	uint32_t stat;
740 	int32_t error;
741 	int i;
742 
743 	error = SYSCTL_OUT(req, &rack_clear_counter, sizeof(uint32_t));
744 	if (error || req->newptr == NULL)
745 		return error;
746 
747 	error = SYSCTL_IN(req, &stat, sizeof(uint32_t));
748 	if (error)
749 		return (error);
750 	if (stat == 1) {
751 #ifdef INVARIANTS
752 		printf("Clearing RACK counters\n");
753 #endif
754 		counter_u64_zero(rack_badfr);
755 		counter_u64_zero(rack_badfr_bytes);
756 		counter_u64_zero(rack_rtm_prr_retran);
757 		counter_u64_zero(rack_rtm_prr_newdata);
758 		counter_u64_zero(rack_timestamp_mismatch);
759 		counter_u64_zero(rack_reorder_seen);
760 		counter_u64_zero(rack_tlp_tot);
761 		counter_u64_zero(rack_tlp_newdata);
762 		counter_u64_zero(rack_tlp_retran);
763 		counter_u64_zero(rack_tlp_retran_bytes);
764 		counter_u64_zero(rack_tlp_retran_fail);
765 		counter_u64_zero(rack_to_tot);
766 		counter_u64_zero(rack_to_arm_rack);
767 		counter_u64_zero(rack_to_arm_tlp);
768 		counter_u64_zero(rack_paced_segments);
769 		counter_u64_zero(rack_calc_zero);
770 		counter_u64_zero(rack_calc_nonzero);
771 		counter_u64_zero(rack_unpaced_segments);
772 		counter_u64_zero(rack_saw_enobuf);
773 		counter_u64_zero(rack_saw_enobuf_hw);
774 		counter_u64_zero(rack_saw_enetunreach);
775 		counter_u64_zero(rack_per_timer_hole);
776 		counter_u64_zero(rack_large_ackcmp);
777 		counter_u64_zero(rack_small_ackcmp);
778 #ifdef INVARIANTS
779 		counter_u64_zero(rack_adjust_map_bw);
780 #endif
781 		counter_u64_zero(rack_to_alloc_hard);
782 		counter_u64_zero(rack_to_alloc_emerg);
783 		counter_u64_zero(rack_sack_proc_all);
784 		counter_u64_zero(rack_fto_send);
785 		counter_u64_zero(rack_fto_rsm_send);
786 		counter_u64_zero(rack_extended_rfo);
787 		counter_u64_zero(rack_hw_pace_init_fail);
788 		counter_u64_zero(rack_hw_pace_lost);
789 		counter_u64_zero(rack_sbsndptr_wrong);
790 		counter_u64_zero(rack_sbsndptr_right);
791 		counter_u64_zero(rack_non_fto_send);
792 		counter_u64_zero(rack_nfto_resend);
793 		counter_u64_zero(rack_sack_proc_short);
794 		counter_u64_zero(rack_sack_proc_restart);
795 		counter_u64_zero(rack_to_alloc);
796 		counter_u64_zero(rack_to_alloc_limited);
797 		counter_u64_zero(rack_alloc_limited_conns);
798 		counter_u64_zero(rack_split_limited);
799 		for (i = 0; i < MAX_NUM_OF_CNTS; i++) {
800 			counter_u64_zero(rack_proc_comp_ack[i]);
801 		}
802 		counter_u64_zero(rack_multi_single_eq);
803 		counter_u64_zero(rack_proc_non_comp_ack);
804 		counter_u64_zero(rack_find_high);
805 		counter_u64_zero(rack_sack_attacks_detected);
806 		counter_u64_zero(rack_sack_attacks_reversed);
807 		counter_u64_zero(rack_sack_used_next_merge);
808 		counter_u64_zero(rack_sack_used_prev_merge);
809 		counter_u64_zero(rack_sack_splits);
810 		counter_u64_zero(rack_sack_skipped_acked);
811 		counter_u64_zero(rack_ack_total);
812 		counter_u64_zero(rack_express_sack);
813 		counter_u64_zero(rack_sack_total);
814 		counter_u64_zero(rack_move_none);
815 		counter_u64_zero(rack_move_some);
816 		counter_u64_zero(rack_used_tlpmethod);
817 		counter_u64_zero(rack_used_tlpmethod2);
818 		counter_u64_zero(rack_enter_tlp_calc);
819 		counter_u64_zero(rack_progress_drops);
820 		counter_u64_zero(rack_tlp_does_nada);
821 		counter_u64_zero(rack_try_scwnd);
822 		counter_u64_zero(rack_collapsed_win);
823 	}
824 	rack_clear_counter = 0;
825 	return (0);
826 }
827 
828 static void
829 rack_init_sysctls(void)
830 {
831 	int i;
832 	struct sysctl_oid *rack_counters;
833 	struct sysctl_oid *rack_attack;
834 	struct sysctl_oid *rack_pacing;
835 	struct sysctl_oid *rack_timely;
836 	struct sysctl_oid *rack_timers;
837 	struct sysctl_oid *rack_tlp;
838 	struct sysctl_oid *rack_misc;
839 	struct sysctl_oid *rack_features;
840 	struct sysctl_oid *rack_measure;
841 	struct sysctl_oid *rack_probertt;
842 	struct sysctl_oid *rack_hw_pacing;
843 
844 	rack_attack = SYSCTL_ADD_NODE(&rack_sysctl_ctx,
845 	    SYSCTL_CHILDREN(rack_sysctl_root),
846 	    OID_AUTO,
847 	    "sack_attack",
848 	    CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
849 	    "Rack Sack Attack Counters and Controls");
850 	rack_counters = SYSCTL_ADD_NODE(&rack_sysctl_ctx,
851 	    SYSCTL_CHILDREN(rack_sysctl_root),
852 	    OID_AUTO,
853 	    "stats",
854 	    CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
855 	    "Rack Counters");
856 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
857 	    SYSCTL_CHILDREN(rack_sysctl_root),
858 	    OID_AUTO, "rate_sample_method", CTLFLAG_RW,
859 	    &rack_rate_sample_method , USE_RTT_LOW,
860 	    "What method should we use for rate sampling 0=high, 1=low ");
861 	/* Probe rtt related controls */
862 	rack_probertt = SYSCTL_ADD_NODE(&rack_sysctl_ctx,
863 	    SYSCTL_CHILDREN(rack_sysctl_root),
864 	    OID_AUTO,
865 	    "probertt",
866 	    CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
867 	    "ProbeRTT related Controls");
868 	SYSCTL_ADD_U16(&rack_sysctl_ctx,
869 	    SYSCTL_CHILDREN(rack_probertt),
870 	    OID_AUTO, "exit_per_hpb", CTLFLAG_RW,
871 	    &rack_atexit_prtt_hbp, 130,
872 	    "What percentage above goodput do we clamp CA/SS to at exit on high-BDP path 110%");
873 	SYSCTL_ADD_U16(&rack_sysctl_ctx,
874 	    SYSCTL_CHILDREN(rack_probertt),
875 	    OID_AUTO, "exit_per_nonhpb", CTLFLAG_RW,
876 	    &rack_atexit_prtt, 130,
877 	    "What percentage above goodput do we clamp CA/SS to at exit on a non high-BDP path 100%");
878 	SYSCTL_ADD_U16(&rack_sysctl_ctx,
879 	    SYSCTL_CHILDREN(rack_probertt),
880 	    OID_AUTO, "gp_per_mul", CTLFLAG_RW,
881 	    &rack_per_of_gp_probertt, 60,
882 	    "What percentage of goodput do we pace at in probertt");
883 	SYSCTL_ADD_U16(&rack_sysctl_ctx,
884 	    SYSCTL_CHILDREN(rack_probertt),
885 	    OID_AUTO, "gp_per_reduce", CTLFLAG_RW,
886 	    &rack_per_of_gp_probertt_reduce, 10,
887 	    "What percentage of goodput do we reduce every gp_srtt");
888 	SYSCTL_ADD_U16(&rack_sysctl_ctx,
889 	    SYSCTL_CHILDREN(rack_probertt),
890 	    OID_AUTO, "gp_per_low", CTLFLAG_RW,
891 	    &rack_per_of_gp_lowthresh, 40,
892 	    "What percentage of goodput do we allow the multiplier to fall to");
893 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
894 	    SYSCTL_CHILDREN(rack_probertt),
895 	    OID_AUTO, "time_between", CTLFLAG_RW,
896 	    & rack_time_between_probertt, 96000000,
897 	    "How many useconds between the lowest rtt falling must past before we enter probertt");
898 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
899 	    SYSCTL_CHILDREN(rack_probertt),
900 	    OID_AUTO, "safety", CTLFLAG_RW,
901 	    &rack_probe_rtt_safety_val, 2000000,
902 	    "If not zero, provides a maximum usecond that you can stay in probertt (2sec = 2000000)");
903 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
904 	    SYSCTL_CHILDREN(rack_probertt),
905 	    OID_AUTO, "sets_cwnd", CTLFLAG_RW,
906 	    &rack_probe_rtt_sets_cwnd, 0,
907 	    "Do we set the cwnd too (if always_lower is on)");
908 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
909 	    SYSCTL_CHILDREN(rack_probertt),
910 	    OID_AUTO, "maxdrainsrtts", CTLFLAG_RW,
911 	    &rack_max_drain_wait, 2,
912 	    "Maximum number of gp_srtt's to hold in drain waiting for flight to reach goal");
913 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
914 	    SYSCTL_CHILDREN(rack_probertt),
915 	    OID_AUTO, "mustdrainsrtts", CTLFLAG_RW,
916 	    &rack_must_drain, 1,
917 	    "We must drain this many gp_srtt's waiting for flight to reach goal");
918 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
919 	    SYSCTL_CHILDREN(rack_probertt),
920 	    OID_AUTO, "goal_use_min_entry", CTLFLAG_RW,
921 	    &rack_probertt_use_min_rtt_entry, 1,
922 	    "Should we use the min-rtt to calculate the goal rtt (else gp_srtt) at entry");
923 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
924 	    SYSCTL_CHILDREN(rack_probertt),
925 	    OID_AUTO, "goal_use_min_exit", CTLFLAG_RW,
926 	    &rack_probertt_use_min_rtt_exit, 0,
927 	    "How to set cwnd at exit, 0 - dynamic, 1 - use min-rtt, 2 - use curgprtt, 3 - entry gp-rtt");
928 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
929 	    SYSCTL_CHILDREN(rack_probertt),
930 	    OID_AUTO, "length_div", CTLFLAG_RW,
931 	    &rack_probertt_gpsrtt_cnt_div, 0,
932 	    "How many recent goodput srtt periods plus hold tim does probertt last (bottom of fraction)");
933 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
934 	    SYSCTL_CHILDREN(rack_probertt),
935 	    OID_AUTO, "length_mul", CTLFLAG_RW,
936 	    &rack_probertt_gpsrtt_cnt_mul, 0,
937 	    "How many recent goodput srtt periods plus hold tim does probertt last (top of fraction)");
938 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
939 	    SYSCTL_CHILDREN(rack_probertt),
940 	    OID_AUTO, "holdtim_at_target", CTLFLAG_RW,
941 	    &rack_min_probertt_hold, 200000,
942 	    "What is the minimum time we hold probertt at target");
943 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
944 	    SYSCTL_CHILDREN(rack_probertt),
945 	    OID_AUTO, "filter_life", CTLFLAG_RW,
946 	    &rack_probertt_filter_life, 10000000,
947 	    "What is the time for the filters life in useconds");
948 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
949 	    SYSCTL_CHILDREN(rack_probertt),
950 	    OID_AUTO, "lower_within", CTLFLAG_RW,
951 	    &rack_probertt_lower_within, 10,
952 	    "If the rtt goes lower within this percentage of the time, go into probe-rtt");
953 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
954 	    SYSCTL_CHILDREN(rack_probertt),
955 	    OID_AUTO, "must_move", CTLFLAG_RW,
956 	    &rack_min_rtt_movement, 250,
957 	    "How much is the minimum movement in rtt to count as a drop for probertt purposes");
958 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
959 	    SYSCTL_CHILDREN(rack_probertt),
960 	    OID_AUTO, "clear_is_cnts", CTLFLAG_RW,
961 	    &rack_probertt_clear_is, 1,
962 	    "Do we clear I/S counts on exiting probe-rtt");
963 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
964 	    SYSCTL_CHILDREN(rack_probertt),
965 	    OID_AUTO, "hbp_extra_drain", CTLFLAG_RW,
966 	    &rack_max_drain_hbp, 1,
967 	    "How many extra drain gpsrtt's do we get in highly buffered paths");
968 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
969 	    SYSCTL_CHILDREN(rack_probertt),
970 	    OID_AUTO, "hbp_threshold", CTLFLAG_RW,
971 	    &rack_hbp_thresh, 3,
972 	    "We are highly buffered if min_rtt_seen / max_rtt_seen > this-threshold");
973 	/* Pacing related sysctls */
974 	rack_pacing = SYSCTL_ADD_NODE(&rack_sysctl_ctx,
975 	    SYSCTL_CHILDREN(rack_sysctl_root),
976 	    OID_AUTO,
977 	    "pacing",
978 	    CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
979 	    "Pacing related Controls");
980 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
981 	    SYSCTL_CHILDREN(rack_pacing),
982 	    OID_AUTO, "max_pace_over", CTLFLAG_RW,
983 	    &rack_max_per_above, 30,
984 	    "What is the maximum allowable percentage that we can pace above (so 30 = 130% of our goal)");
985 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
986 	    SYSCTL_CHILDREN(rack_pacing),
987 	    OID_AUTO, "pace_to_one", CTLFLAG_RW,
988 	    &rack_pace_one_seg, 0,
989 	    "Do we allow low b/w pacing of 1MSS instead of two");
990 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
991 	    SYSCTL_CHILDREN(rack_pacing),
992 	    OID_AUTO, "limit_wsrtt", CTLFLAG_RW,
993 	    &rack_limit_time_with_srtt, 0,
994 	    "Do we limit pacing time based on srtt");
995 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
996 	    SYSCTL_CHILDREN(rack_pacing),
997 	    OID_AUTO, "init_win", CTLFLAG_RW,
998 	    &rack_default_init_window, 0,
999 	    "Do we have a rack initial window 0 = system default");
1000 	SYSCTL_ADD_U16(&rack_sysctl_ctx,
1001 	    SYSCTL_CHILDREN(rack_pacing),
1002 	    OID_AUTO, "gp_per_ss", CTLFLAG_RW,
1003 	    &rack_per_of_gp_ss, 250,
1004 	    "If non zero, what percentage of goodput to pace at in slow start");
1005 	SYSCTL_ADD_U16(&rack_sysctl_ctx,
1006 	    SYSCTL_CHILDREN(rack_pacing),
1007 	    OID_AUTO, "gp_per_ca", CTLFLAG_RW,
1008 	    &rack_per_of_gp_ca, 150,
1009 	    "If non zero, what percentage of goodput to pace at in congestion avoidance");
1010 	SYSCTL_ADD_U16(&rack_sysctl_ctx,
1011 	    SYSCTL_CHILDREN(rack_pacing),
1012 	    OID_AUTO, "gp_per_rec", CTLFLAG_RW,
1013 	    &rack_per_of_gp_rec, 200,
1014 	    "If non zero, what percentage of goodput to pace at in recovery");
1015 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1016 	    SYSCTL_CHILDREN(rack_pacing),
1017 	    OID_AUTO, "pace_max_seg", CTLFLAG_RW,
1018 	    &rack_hptsi_segments, 40,
1019 	    "What size is the max for TSO segments in pacing and burst mitigation");
1020 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1021 	    SYSCTL_CHILDREN(rack_pacing),
1022 	    OID_AUTO, "burst_reduces", CTLFLAG_RW,
1023 	    &rack_slot_reduction, 4,
1024 	    "When doing only burst mitigation what is the reduce divisor");
1025 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1026 	    SYSCTL_CHILDREN(rack_sysctl_root),
1027 	    OID_AUTO, "use_pacing", CTLFLAG_RW,
1028 	    &rack_pace_every_seg, 0,
1029 	    "If set we use pacing, if clear we use only the original burst mitigation");
1030 	SYSCTL_ADD_U64(&rack_sysctl_ctx,
1031 	    SYSCTL_CHILDREN(rack_pacing),
1032 	    OID_AUTO, "rate_cap", CTLFLAG_RW,
1033 	    &rack_bw_rate_cap, 0,
1034 	    "If set we apply this value to the absolute rate cap used by pacing");
1035 	SYSCTL_ADD_U8(&rack_sysctl_ctx,
1036 	    SYSCTL_CHILDREN(rack_sysctl_root),
1037 	    OID_AUTO, "req_measure_cnt", CTLFLAG_RW,
1038 	    &rack_req_measurements, 1,
1039 	    "If doing dynamic pacing, how many measurements must be in before we start pacing?");
1040 	/* Hardware pacing */
1041 	rack_hw_pacing = SYSCTL_ADD_NODE(&rack_sysctl_ctx,
1042 	    SYSCTL_CHILDREN(rack_sysctl_root),
1043 	    OID_AUTO,
1044 	    "hdwr_pacing",
1045 	    CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
1046 	    "Pacing related Controls");
1047 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1048 	    SYSCTL_CHILDREN(rack_hw_pacing),
1049 	    OID_AUTO, "rwnd_factor", CTLFLAG_RW,
1050 	    &rack_hw_rwnd_factor, 2,
1051 	    "How many times does snd_wnd need to be bigger than pace_max_seg so we will hold off and get more acks?");
1052 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1053 	    SYSCTL_CHILDREN(rack_hw_pacing),
1054 	    OID_AUTO, "pace_enobuf_mult", CTLFLAG_RW,
1055 	    &rack_enobuf_hw_boost_mult, 2,
1056 	    "By how many time_betweens should we boost the pacing time if we see a ENOBUFS?");
1057 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1058 	    SYSCTL_CHILDREN(rack_hw_pacing),
1059 	    OID_AUTO, "pace_enobuf_max", CTLFLAG_RW,
1060 	    &rack_enobuf_hw_max, 2,
1061 	    "What is the max boost the pacing time if we see a ENOBUFS?");
1062 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1063 	    SYSCTL_CHILDREN(rack_hw_pacing),
1064 	    OID_AUTO, "pace_enobuf_min", CTLFLAG_RW,
1065 	    &rack_enobuf_hw_min, 2,
1066 	    "What is the min boost the pacing time if we see a ENOBUFS?");
1067 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1068 	    SYSCTL_CHILDREN(rack_hw_pacing),
1069 	    OID_AUTO, "enable", CTLFLAG_RW,
1070 	    &rack_enable_hw_pacing, 0,
1071 	    "Should RACK attempt to use hw pacing?");
1072 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1073 	    SYSCTL_CHILDREN(rack_hw_pacing),
1074 	    OID_AUTO, "rate_cap", CTLFLAG_RW,
1075 	    &rack_hw_rate_caps, 1,
1076 	    "Does the highest hardware pacing rate cap the rate we will send at??");
1077 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1078 	    SYSCTL_CHILDREN(rack_hw_pacing),
1079 	    OID_AUTO, "rate_min", CTLFLAG_RW,
1080 	    &rack_hw_rate_min, 0,
1081 	    "Do we need a minimum estimate of this many bytes per second in order to engage hw pacing?");
1082 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1083 	    SYSCTL_CHILDREN(rack_hw_pacing),
1084 	    OID_AUTO, "rate_to_low", CTLFLAG_RW,
1085 	    &rack_hw_rate_to_low, 0,
1086 	    "If we fall below this rate, dis-engage hw pacing?");
1087 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1088 	    SYSCTL_CHILDREN(rack_hw_pacing),
1089 	    OID_AUTO, "up_only", CTLFLAG_RW,
1090 	    &rack_hw_up_only, 1,
1091 	    "Do we allow hw pacing to lower the rate selected?");
1092 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1093 	    SYSCTL_CHILDREN(rack_hw_pacing),
1094 	    OID_AUTO, "extra_mss_precise", CTLFLAG_RW,
1095 	    &rack_hw_pace_extra_slots, 2,
1096 	    "If the rates between software and hardware match precisely how many extra time_betweens do we get?");
1097 	rack_timely = SYSCTL_ADD_NODE(&rack_sysctl_ctx,
1098 	    SYSCTL_CHILDREN(rack_sysctl_root),
1099 	    OID_AUTO,
1100 	    "timely",
1101 	    CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
1102 	    "Rack Timely RTT Controls");
1103 	/* Timely based GP dynmics */
1104 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1105 	    SYSCTL_CHILDREN(rack_timely),
1106 	    OID_AUTO, "upper", CTLFLAG_RW,
1107 	    &rack_gp_per_bw_mul_up, 2,
1108 	    "Rack timely upper range for equal b/w (in percentage)");
1109 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1110 	    SYSCTL_CHILDREN(rack_timely),
1111 	    OID_AUTO, "lower", CTLFLAG_RW,
1112 	    &rack_gp_per_bw_mul_down, 4,
1113 	    "Rack timely lower range for equal b/w (in percentage)");
1114 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1115 	    SYSCTL_CHILDREN(rack_timely),
1116 	    OID_AUTO, "rtt_max_mul", CTLFLAG_RW,
1117 	    &rack_gp_rtt_maxmul, 3,
1118 	    "Rack timely multipler of lowest rtt for rtt_max");
1119 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1120 	    SYSCTL_CHILDREN(rack_timely),
1121 	    OID_AUTO, "rtt_min_div", CTLFLAG_RW,
1122 	    &rack_gp_rtt_mindiv, 4,
1123 	    "Rack timely divisor used for rtt + (rtt * mul/divisor) for check for lower rtt");
1124 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1125 	    SYSCTL_CHILDREN(rack_timely),
1126 	    OID_AUTO, "rtt_min_mul", CTLFLAG_RW,
1127 	    &rack_gp_rtt_minmul, 1,
1128 	    "Rack timely multiplier used for rtt + (rtt * mul/divisor) for check for lower rtt");
1129 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1130 	    SYSCTL_CHILDREN(rack_timely),
1131 	    OID_AUTO, "decrease", CTLFLAG_RW,
1132 	    &rack_gp_decrease_per, 20,
1133 	    "Rack timely decrease percentage of our GP multiplication factor");
1134 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1135 	    SYSCTL_CHILDREN(rack_timely),
1136 	    OID_AUTO, "increase", CTLFLAG_RW,
1137 	    &rack_gp_increase_per, 2,
1138 	    "Rack timely increase perentage of our GP multiplication factor");
1139 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1140 	    SYSCTL_CHILDREN(rack_timely),
1141 	    OID_AUTO, "lowerbound", CTLFLAG_RW,
1142 	    &rack_per_lower_bound, 50,
1143 	    "Rack timely lowest percentage we allow GP multiplier to fall to");
1144 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1145 	    SYSCTL_CHILDREN(rack_timely),
1146 	    OID_AUTO, "upperboundss", CTLFLAG_RW,
1147 	    &rack_per_upper_bound_ss, 0,
1148 	    "Rack timely higest percentage we allow GP multiplier in SS to raise to (0 is no upperbound)");
1149 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1150 	    SYSCTL_CHILDREN(rack_timely),
1151 	    OID_AUTO, "upperboundca", CTLFLAG_RW,
1152 	    &rack_per_upper_bound_ca, 0,
1153 	    "Rack timely higest percentage we allow GP multiplier to CA raise to (0 is no upperbound)");
1154 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1155 	    SYSCTL_CHILDREN(rack_timely),
1156 	    OID_AUTO, "dynamicgp", CTLFLAG_RW,
1157 	    &rack_do_dyn_mul, 0,
1158 	    "Rack timely do we enable dynmaic timely goodput by default");
1159 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1160 	    SYSCTL_CHILDREN(rack_timely),
1161 	    OID_AUTO, "no_rec_red", CTLFLAG_RW,
1162 	    &rack_gp_no_rec_chg, 1,
1163 	    "Rack timely do we prohibit the recovery multiplier from being lowered");
1164 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1165 	    SYSCTL_CHILDREN(rack_timely),
1166 	    OID_AUTO, "red_clear_cnt", CTLFLAG_RW,
1167 	    &rack_timely_dec_clear, 6,
1168 	    "Rack timely what threshold do we count to before another boost during b/w decent");
1169 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1170 	    SYSCTL_CHILDREN(rack_timely),
1171 	    OID_AUTO, "max_push_rise", CTLFLAG_RW,
1172 	    &rack_timely_max_push_rise, 3,
1173 	    "Rack timely how many times do we push up with b/w increase");
1174 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1175 	    SYSCTL_CHILDREN(rack_timely),
1176 	    OID_AUTO, "max_push_drop", CTLFLAG_RW,
1177 	    &rack_timely_max_push_drop, 3,
1178 	    "Rack timely how many times do we push back on b/w decent");
1179 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1180 	    SYSCTL_CHILDREN(rack_timely),
1181 	    OID_AUTO, "min_segs", CTLFLAG_RW,
1182 	    &rack_timely_min_segs, 4,
1183 	    "Rack timely when setting the cwnd what is the min num segments");
1184 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1185 	    SYSCTL_CHILDREN(rack_timely),
1186 	    OID_AUTO, "noback_max", CTLFLAG_RW,
1187 	    &rack_use_max_for_nobackoff, 0,
1188 	    "Rack timely when deciding if to backoff on a loss, do we use under max rtt else min");
1189 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1190 	    SYSCTL_CHILDREN(rack_timely),
1191 	    OID_AUTO, "interim_timely_only", CTLFLAG_RW,
1192 	    &rack_timely_int_timely_only, 0,
1193 	    "Rack timely when doing interim timely's do we only do timely (no b/w consideration)");
1194 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1195 	    SYSCTL_CHILDREN(rack_timely),
1196 	    OID_AUTO, "nonstop", CTLFLAG_RW,
1197 	    &rack_timely_no_stopping, 0,
1198 	    "Rack timely don't stop increase");
1199 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1200 	    SYSCTL_CHILDREN(rack_timely),
1201 	    OID_AUTO, "dec_raise_thresh", CTLFLAG_RW,
1202 	    &rack_down_raise_thresh, 100,
1203 	    "If the CA or SS is below this threshold raise on the first 3 b/w lowers (0=always)");
1204 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1205 	    SYSCTL_CHILDREN(rack_timely),
1206 	    OID_AUTO, "bottom_drag_segs", CTLFLAG_RW,
1207 	    &rack_req_segs, 1,
1208 	    "Bottom dragging if not these many segments outstanding and room");
1209 
1210 	/* TLP and Rack related parameters */
1211 	rack_tlp = SYSCTL_ADD_NODE(&rack_sysctl_ctx,
1212 	    SYSCTL_CHILDREN(rack_sysctl_root),
1213 	    OID_AUTO,
1214 	    "tlp",
1215 	    CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
1216 	    "TLP and Rack related Controls");
1217 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1218 	    SYSCTL_CHILDREN(rack_tlp),
1219 	    OID_AUTO, "use_rrr", CTLFLAG_RW,
1220 	    &use_rack_rr, 1,
1221 	    "Do we use Rack Rapid Recovery");
1222 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1223 	    SYSCTL_CHILDREN(rack_tlp),
1224 	    OID_AUTO, "post_rec_labc", CTLFLAG_RW,
1225 	    &rack_max_abc_post_recovery, 2,
1226 	    "Since we do early recovery, do we override the l_abc to a value, if so what?");
1227 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1228 	    SYSCTL_CHILDREN(rack_tlp),
1229 	    OID_AUTO, "nonrxt_use_cr", CTLFLAG_RW,
1230 	    &rack_non_rxt_use_cr, 0,
1231 	    "Do we use ss/ca rate if in recovery we are transmitting a new data chunk");
1232 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1233 	    SYSCTL_CHILDREN(rack_tlp),
1234 	    OID_AUTO, "tlpmethod", CTLFLAG_RW,
1235 	    &rack_tlp_threshold_use, TLP_USE_TWO_ONE,
1236 	    "What method do we do for TLP time calc 0=no-de-ack-comp, 1=ID, 2=2.1, 3=2.2");
1237 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1238 	    SYSCTL_CHILDREN(rack_tlp),
1239 	    OID_AUTO, "limit", CTLFLAG_RW,
1240 	    &rack_tlp_limit, 2,
1241 	    "How many TLP's can be sent without sending new data");
1242 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1243 	    SYSCTL_CHILDREN(rack_tlp),
1244 	    OID_AUTO, "use_greater", CTLFLAG_RW,
1245 	    &rack_tlp_use_greater, 1,
1246 	    "Should we use the rack_rtt time if its greater than srtt");
1247 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1248 	    SYSCTL_CHILDREN(rack_tlp),
1249 	    OID_AUTO, "tlpminto", CTLFLAG_RW,
1250 	    &rack_tlp_min, 10000,
1251 	    "TLP minimum timeout per the specification (in microseconds)");
1252 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1253 	    SYSCTL_CHILDREN(rack_tlp),
1254 	    OID_AUTO, "send_oldest", CTLFLAG_RW,
1255 	    &rack_always_send_oldest, 0,
1256 	    "Should we always send the oldest TLP and RACK-TLP");
1257 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1258 	    SYSCTL_CHILDREN(rack_tlp),
1259 	    OID_AUTO, "rack_tlimit", CTLFLAG_RW,
1260 	    &rack_limited_retran, 0,
1261 	    "How many times can a rack timeout drive out sends");
1262 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1263 	    SYSCTL_CHILDREN(rack_tlp),
1264 	    OID_AUTO, "tlp_cwnd_flag", CTLFLAG_RW,
1265 	    &rack_lower_cwnd_at_tlp, 0,
1266 	    "When a TLP completes a retran should we enter recovery");
1267 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1268 	    SYSCTL_CHILDREN(rack_tlp),
1269 	    OID_AUTO, "reorder_thresh", CTLFLAG_RW,
1270 	    &rack_reorder_thresh, 2,
1271 	    "What factor for rack will be added when seeing reordering (shift right)");
1272 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1273 	    SYSCTL_CHILDREN(rack_tlp),
1274 	    OID_AUTO, "rtt_tlp_thresh", CTLFLAG_RW,
1275 	    &rack_tlp_thresh, 1,
1276 	    "What divisor for TLP rtt/retran will be added (1=rtt, 2=1/2 rtt etc)");
1277 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1278 	    SYSCTL_CHILDREN(rack_tlp),
1279 	    OID_AUTO, "reorder_fade", CTLFLAG_RW,
1280 	    &rack_reorder_fade, 60000000,
1281 	    "Does reorder detection fade, if so how many microseconds (0 means never)");
1282 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1283 	    SYSCTL_CHILDREN(rack_tlp),
1284 	    OID_AUTO, "pktdelay", CTLFLAG_RW,
1285 	    &rack_pkt_delay, 1000,
1286 	    "Extra RACK time (in microseconds) besides reordering thresh");
1287 
1288 	/* Timer related controls */
1289 	rack_timers = SYSCTL_ADD_NODE(&rack_sysctl_ctx,
1290 	    SYSCTL_CHILDREN(rack_sysctl_root),
1291 	    OID_AUTO,
1292 	    "timers",
1293 	    CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
1294 	    "Timer related controls");
1295 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
1296 	    SYSCTL_CHILDREN(rack_timers),
1297 	    OID_AUTO, "persmin", CTLFLAG_RW,
1298 	    &rack_persist_min, 250000,
1299 	    "What is the minimum time in microseconds between persists");
1300 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
1301 	    SYSCTL_CHILDREN(rack_timers),
1302 	    OID_AUTO, "persmax", CTLFLAG_RW,
1303 	    &rack_persist_max, 2000000,
1304 	    "What is the largest delay in microseconds between persists");
1305 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1306 	    SYSCTL_CHILDREN(rack_timers),
1307 	    OID_AUTO, "delayed_ack", CTLFLAG_RW,
1308 	    &rack_delayed_ack_time, 40000,
1309 	    "Delayed ack time (40ms in microseconds)");
1310 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1311 	    SYSCTL_CHILDREN(rack_timers),
1312 	    OID_AUTO, "minrto", CTLFLAG_RW,
1313 	    &rack_rto_min, 30000,
1314 	    "Minimum RTO in microseconds -- set with caution below 1000 due to TLP");
1315 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1316 	    SYSCTL_CHILDREN(rack_timers),
1317 	    OID_AUTO, "maxrto", CTLFLAG_RW,
1318 	    &rack_rto_max, 4000000,
1319 	    "Maxiumum RTO in microseconds -- should be at least as large as min_rto");
1320 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1321 	    SYSCTL_CHILDREN(rack_timers),
1322 	    OID_AUTO, "minto", CTLFLAG_RW,
1323 	    &rack_min_to, 1000,
1324 	    "Minimum rack timeout in microseconds");
1325 	/* Measure controls */
1326 	rack_measure = SYSCTL_ADD_NODE(&rack_sysctl_ctx,
1327 	    SYSCTL_CHILDREN(rack_sysctl_root),
1328 	    OID_AUTO,
1329 	    "measure",
1330 	    CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
1331 	    "Measure related controls");
1332 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1333 	    SYSCTL_CHILDREN(rack_measure),
1334 	    OID_AUTO, "wma_divisor", CTLFLAG_RW,
1335 	    &rack_wma_divisor, 8,
1336 	    "When doing b/w calculation what is the  divisor for the WMA");
1337 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1338 	    SYSCTL_CHILDREN(rack_measure),
1339 	    OID_AUTO, "end_cwnd", CTLFLAG_RW,
1340 	    &rack_cwnd_block_ends_measure, 0,
1341 	    "Does a cwnd just-return end the measurement window (app limited)");
1342 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1343 	    SYSCTL_CHILDREN(rack_measure),
1344 	    OID_AUTO, "end_rwnd", CTLFLAG_RW,
1345 	    &rack_rwnd_block_ends_measure, 0,
1346 	    "Does an rwnd just-return end the measurement window (app limited -- not persists)");
1347 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
1348 	    SYSCTL_CHILDREN(rack_measure),
1349 	    OID_AUTO, "min_target", CTLFLAG_RW,
1350 	    &rack_def_data_window, 20,
1351 	    "What is the minimum target window (in mss) for a GP measurements");
1352 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
1353 	    SYSCTL_CHILDREN(rack_measure),
1354 	    OID_AUTO, "goal_bdp", CTLFLAG_RW,
1355 	    &rack_goal_bdp, 2,
1356 	    "What is the goal BDP to measure");
1357 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
1358 	    SYSCTL_CHILDREN(rack_measure),
1359 	    OID_AUTO, "min_srtts", CTLFLAG_RW,
1360 	    &rack_min_srtts, 1,
1361 	    "What is the goal BDP to measure");
1362 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
1363 	    SYSCTL_CHILDREN(rack_measure),
1364 	    OID_AUTO, "min_measure_tim", CTLFLAG_RW,
1365 	    &rack_min_measure_usec, 0,
1366 	    "What is the Minimum time time for a measurement if 0, this is off");
1367 	/* Features */
1368 	rack_features = SYSCTL_ADD_NODE(&rack_sysctl_ctx,
1369 	    SYSCTL_CHILDREN(rack_sysctl_root),
1370 	    OID_AUTO,
1371 	    "features",
1372 	    CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
1373 	    "Feature controls");
1374 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1375 	    SYSCTL_CHILDREN(rack_features),
1376 	    OID_AUTO, "cmpack", CTLFLAG_RW,
1377 	    &rack_use_cmp_acks, 1,
1378 	    "Should RACK have LRO send compressed acks");
1379 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1380 	    SYSCTL_CHILDREN(rack_features),
1381 	    OID_AUTO, "fsb", CTLFLAG_RW,
1382 	    &rack_use_fsb, 1,
1383 	    "Should RACK use the fast send block?");
1384 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1385 	    SYSCTL_CHILDREN(rack_features),
1386 	    OID_AUTO, "rfo", CTLFLAG_RW,
1387 	    &rack_use_rfo, 1,
1388 	    "Should RACK use rack_fast_output()?");
1389 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1390 	    SYSCTL_CHILDREN(rack_features),
1391 	    OID_AUTO, "rsmrfo", CTLFLAG_RW,
1392 	    &rack_use_rsm_rfo, 1,
1393 	    "Should RACK use rack_fast_rsm_output()?");
1394 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1395 	    SYSCTL_CHILDREN(rack_features),
1396 	    OID_AUTO, "non_paced_lro_queue", CTLFLAG_RW,
1397 	    &rack_enable_mqueue_for_nonpaced, 0,
1398 	    "Should RACK use mbuf queuing for non-paced connections");
1399 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1400 	    SYSCTL_CHILDREN(rack_features),
1401 	    OID_AUTO, "hystartplusplus", CTLFLAG_RW,
1402 	    &rack_do_hystart, 0,
1403 	    "Should RACK enable HyStart++ on connections?");
1404 	/* Misc rack controls */
1405 	rack_misc = SYSCTL_ADD_NODE(&rack_sysctl_ctx,
1406 	    SYSCTL_CHILDREN(rack_sysctl_root),
1407 	    OID_AUTO,
1408 	    "misc",
1409 	    CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
1410 	    "Misc related controls");
1411 #ifdef TCP_ACCOUNTING
1412 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1413 	    SYSCTL_CHILDREN(rack_misc),
1414 	    OID_AUTO, "tcp_acct", CTLFLAG_RW,
1415 	    &rack_tcp_accounting, 0,
1416 	    "Should we turn on TCP accounting for all rack sessions?");
1417 #endif
1418 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1419 	    SYSCTL_CHILDREN(rack_misc),
1420 	    OID_AUTO, "rack_dsack_ctl", CTLFLAG_RW,
1421 	    &rack_dsack_std_based, 3,
1422 	    "How do we process dsack with respect to rack timers, bit field, 3 is standards based?");
1423 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1424 	    SYSCTL_CHILDREN(rack_misc),
1425 	    OID_AUTO, "prr_addback_max", CTLFLAG_RW,
1426 	    &rack_prr_addbackmax, 2,
1427 	    "What is the maximum number of MSS we allow to be added back if prr can't send all its data?");
1428 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1429 	    SYSCTL_CHILDREN(rack_misc),
1430 	    OID_AUTO, "stats_gets_ms", CTLFLAG_RW,
1431 	    &rack_stats_gets_ms_rtt, 1,
1432 	    "What do we feed the stats framework (1 = ms_rtt, 0 = us_rtt, 2 = ms_rtt from hdwr, > 2 usec rtt from hdwr)?");
1433 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1434 	    SYSCTL_CHILDREN(rack_misc),
1435 	    OID_AUTO, "clientlowbuf", CTLFLAG_RW,
1436 	    &rack_client_low_buf, 0,
1437 	    "Client low buffer level (below this we are more aggressive in DGP exiting recovery (0 = off)?");
1438 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1439 	    SYSCTL_CHILDREN(rack_misc),
1440 	    OID_AUTO, "defprofile", CTLFLAG_RW,
1441 	    &rack_def_profile, 0,
1442 	    "Should RACK use a default profile (0=no, num == profile num)?");
1443 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1444 	    SYSCTL_CHILDREN(rack_misc),
1445 	    OID_AUTO, "shared_cwnd", CTLFLAG_RW,
1446 	    &rack_enable_shared_cwnd, 1,
1447 	    "Should RACK try to use the shared cwnd on connections where allowed");
1448 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1449 	    SYSCTL_CHILDREN(rack_misc),
1450 	    OID_AUTO, "limits_on_scwnd", CTLFLAG_RW,
1451 	    &rack_limits_scwnd, 1,
1452 	    "Should RACK place low end time limits on the shared cwnd feature");
1453 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1454 	    SYSCTL_CHILDREN(rack_misc),
1455 	    OID_AUTO, "iMac_dack", CTLFLAG_RW,
1456 	    &rack_use_imac_dack, 0,
1457 	    "Should RACK try to emulate iMac delayed ack");
1458 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1459 	    SYSCTL_CHILDREN(rack_misc),
1460 	    OID_AUTO, "no_prr", CTLFLAG_RW,
1461 	    &rack_disable_prr, 0,
1462 	    "Should RACK not use prr and only pace (must have pacing on)");
1463 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1464 	    SYSCTL_CHILDREN(rack_misc),
1465 	    OID_AUTO, "bb_verbose", CTLFLAG_RW,
1466 	    &rack_verbose_logging, 0,
1467 	    "Should RACK black box logging be verbose");
1468 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1469 	    SYSCTL_CHILDREN(rack_misc),
1470 	    OID_AUTO, "data_after_close", CTLFLAG_RW,
1471 	    &rack_ignore_data_after_close, 1,
1472 	    "Do we hold off sending a RST until all pending data is ack'd");
1473 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1474 	    SYSCTL_CHILDREN(rack_misc),
1475 	    OID_AUTO, "no_sack_needed", CTLFLAG_RW,
1476 	    &rack_sack_not_required, 1,
1477 	    "Do we allow rack to run on connections not supporting SACK");
1478 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1479 	    SYSCTL_CHILDREN(rack_misc),
1480 	    OID_AUTO, "prr_sendalot", CTLFLAG_RW,
1481 	    &rack_send_a_lot_in_prr, 1,
1482 	    "Send a lot in prr");
1483 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1484 	    SYSCTL_CHILDREN(rack_misc),
1485 	    OID_AUTO, "autoscale", CTLFLAG_RW,
1486 	    &rack_autosndbuf_inc, 20,
1487 	    "What percentage should rack scale up its snd buffer by?");
1488 	/* Sack Attacker detection stuff */
1489 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
1490 	    SYSCTL_CHILDREN(rack_attack),
1491 	    OID_AUTO, "detect_highsackratio", CTLFLAG_RW,
1492 	    &rack_highest_sack_thresh_seen, 0,
1493 	    "Highest sack to ack ratio seen");
1494 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
1495 	    SYSCTL_CHILDREN(rack_attack),
1496 	    OID_AUTO, "detect_highmoveratio", CTLFLAG_RW,
1497 	    &rack_highest_move_thresh_seen, 0,
1498 	    "Highest move to non-move ratio seen");
1499 	rack_ack_total = counter_u64_alloc(M_WAITOK);
1500 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1501 	    SYSCTL_CHILDREN(rack_attack),
1502 	    OID_AUTO, "acktotal", CTLFLAG_RD,
1503 	    &rack_ack_total,
1504 	    "Total number of Ack's");
1505 	rack_express_sack = counter_u64_alloc(M_WAITOK);
1506 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1507 	    SYSCTL_CHILDREN(rack_attack),
1508 	    OID_AUTO, "exp_sacktotal", CTLFLAG_RD,
1509 	    &rack_express_sack,
1510 	    "Total expresss number of Sack's");
1511 	rack_sack_total = counter_u64_alloc(M_WAITOK);
1512 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1513 	    SYSCTL_CHILDREN(rack_attack),
1514 	    OID_AUTO, "sacktotal", CTLFLAG_RD,
1515 	    &rack_sack_total,
1516 	    "Total number of SACKs");
1517 	rack_move_none = counter_u64_alloc(M_WAITOK);
1518 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1519 	    SYSCTL_CHILDREN(rack_attack),
1520 	    OID_AUTO, "move_none", CTLFLAG_RD,
1521 	    &rack_move_none,
1522 	    "Total number of SACK index reuse of postions under threshold");
1523 	rack_move_some = counter_u64_alloc(M_WAITOK);
1524 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1525 	    SYSCTL_CHILDREN(rack_attack),
1526 	    OID_AUTO, "move_some", CTLFLAG_RD,
1527 	    &rack_move_some,
1528 	    "Total number of SACK index reuse of postions over threshold");
1529 	rack_sack_attacks_detected = counter_u64_alloc(M_WAITOK);
1530 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1531 	    SYSCTL_CHILDREN(rack_attack),
1532 	    OID_AUTO, "attacks", CTLFLAG_RD,
1533 	    &rack_sack_attacks_detected,
1534 	    "Total number of SACK attackers that had sack disabled");
1535 	rack_sack_attacks_reversed = counter_u64_alloc(M_WAITOK);
1536 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1537 	    SYSCTL_CHILDREN(rack_attack),
1538 	    OID_AUTO, "reversed", CTLFLAG_RD,
1539 	    &rack_sack_attacks_reversed,
1540 	    "Total number of SACK attackers that were later determined false positive");
1541 	rack_sack_used_next_merge = counter_u64_alloc(M_WAITOK);
1542 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1543 	    SYSCTL_CHILDREN(rack_attack),
1544 	    OID_AUTO, "nextmerge", CTLFLAG_RD,
1545 	    &rack_sack_used_next_merge,
1546 	    "Total number of times we used the next merge");
1547 	rack_sack_used_prev_merge = counter_u64_alloc(M_WAITOK);
1548 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1549 	    SYSCTL_CHILDREN(rack_attack),
1550 	    OID_AUTO, "prevmerge", CTLFLAG_RD,
1551 	    &rack_sack_used_prev_merge,
1552 	    "Total number of times we used the prev merge");
1553 	/* Counters */
1554 	rack_fto_send = counter_u64_alloc(M_WAITOK);
1555 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1556 	    SYSCTL_CHILDREN(rack_counters),
1557 	    OID_AUTO, "fto_send", CTLFLAG_RD,
1558 	    &rack_fto_send, "Total number of rack_fast_output sends");
1559 	rack_fto_rsm_send = counter_u64_alloc(M_WAITOK);
1560 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1561 	    SYSCTL_CHILDREN(rack_counters),
1562 	    OID_AUTO, "fto_rsm_send", CTLFLAG_RD,
1563 	    &rack_fto_rsm_send, "Total number of rack_fast_rsm_output sends");
1564 	rack_nfto_resend = counter_u64_alloc(M_WAITOK);
1565 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1566 	    SYSCTL_CHILDREN(rack_counters),
1567 	    OID_AUTO, "nfto_resend", CTLFLAG_RD,
1568 	    &rack_nfto_resend, "Total number of rack_output retransmissions");
1569 	rack_non_fto_send = counter_u64_alloc(M_WAITOK);
1570 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1571 	    SYSCTL_CHILDREN(rack_counters),
1572 	    OID_AUTO, "nfto_send", CTLFLAG_RD,
1573 	    &rack_non_fto_send, "Total number of rack_output first sends");
1574 	rack_extended_rfo = counter_u64_alloc(M_WAITOK);
1575 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1576 	    SYSCTL_CHILDREN(rack_counters),
1577 	    OID_AUTO, "rfo_extended", CTLFLAG_RD,
1578 	    &rack_extended_rfo, "Total number of times we extended rfo");
1579 
1580 	rack_hw_pace_init_fail = counter_u64_alloc(M_WAITOK);
1581 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1582 	    SYSCTL_CHILDREN(rack_counters),
1583 	    OID_AUTO, "hwpace_init_fail", CTLFLAG_RD,
1584 	    &rack_hw_pace_init_fail, "Total number of times we failed to initialize hw pacing");
1585 	rack_hw_pace_lost = counter_u64_alloc(M_WAITOK);
1586 
1587 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1588 	    SYSCTL_CHILDREN(rack_counters),
1589 	    OID_AUTO, "hwpace_lost", CTLFLAG_RD,
1590 	    &rack_hw_pace_lost, "Total number of times we failed to initialize hw pacing");
1591 	rack_badfr = counter_u64_alloc(M_WAITOK);
1592 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1593 	    SYSCTL_CHILDREN(rack_counters),
1594 	    OID_AUTO, "badfr", CTLFLAG_RD,
1595 	    &rack_badfr, "Total number of bad FRs");
1596 	rack_badfr_bytes = counter_u64_alloc(M_WAITOK);
1597 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1598 	    SYSCTL_CHILDREN(rack_counters),
1599 	    OID_AUTO, "badfr_bytes", CTLFLAG_RD,
1600 	    &rack_badfr_bytes, "Total number of bad FRs");
1601 	rack_rtm_prr_retran = counter_u64_alloc(M_WAITOK);
1602 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1603 	    SYSCTL_CHILDREN(rack_counters),
1604 	    OID_AUTO, "prrsndret", CTLFLAG_RD,
1605 	    &rack_rtm_prr_retran,
1606 	    "Total number of prr based retransmits");
1607 	rack_rtm_prr_newdata = counter_u64_alloc(M_WAITOK);
1608 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1609 	    SYSCTL_CHILDREN(rack_counters),
1610 	    OID_AUTO, "prrsndnew", CTLFLAG_RD,
1611 	    &rack_rtm_prr_newdata,
1612 	    "Total number of prr based new transmits");
1613 	rack_timestamp_mismatch = counter_u64_alloc(M_WAITOK);
1614 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1615 	    SYSCTL_CHILDREN(rack_counters),
1616 	    OID_AUTO, "tsnf", CTLFLAG_RD,
1617 	    &rack_timestamp_mismatch,
1618 	    "Total number of timestamps that we could not find the reported ts");
1619 	rack_find_high = counter_u64_alloc(M_WAITOK);
1620 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1621 	    SYSCTL_CHILDREN(rack_counters),
1622 	    OID_AUTO, "findhigh", CTLFLAG_RD,
1623 	    &rack_find_high,
1624 	    "Total number of FIN causing find-high");
1625 	rack_reorder_seen = counter_u64_alloc(M_WAITOK);
1626 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1627 	    SYSCTL_CHILDREN(rack_counters),
1628 	    OID_AUTO, "reordering", CTLFLAG_RD,
1629 	    &rack_reorder_seen,
1630 	    "Total number of times we added delay due to reordering");
1631 	rack_tlp_tot = counter_u64_alloc(M_WAITOK);
1632 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1633 	    SYSCTL_CHILDREN(rack_counters),
1634 	    OID_AUTO, "tlp_to_total", CTLFLAG_RD,
1635 	    &rack_tlp_tot,
1636 	    "Total number of tail loss probe expirations");
1637 	rack_tlp_newdata = counter_u64_alloc(M_WAITOK);
1638 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1639 	    SYSCTL_CHILDREN(rack_counters),
1640 	    OID_AUTO, "tlp_new", CTLFLAG_RD,
1641 	    &rack_tlp_newdata,
1642 	    "Total number of tail loss probe sending new data");
1643 	rack_tlp_retran = counter_u64_alloc(M_WAITOK);
1644 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1645 	    SYSCTL_CHILDREN(rack_counters),
1646 	    OID_AUTO, "tlp_retran", CTLFLAG_RD,
1647 	    &rack_tlp_retran,
1648 	    "Total number of tail loss probe sending retransmitted data");
1649 	rack_tlp_retran_bytes = counter_u64_alloc(M_WAITOK);
1650 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1651 	    SYSCTL_CHILDREN(rack_counters),
1652 	    OID_AUTO, "tlp_retran_bytes", CTLFLAG_RD,
1653 	    &rack_tlp_retran_bytes,
1654 	    "Total bytes of tail loss probe sending retransmitted data");
1655 	rack_tlp_retran_fail = counter_u64_alloc(M_WAITOK);
1656 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1657 	    SYSCTL_CHILDREN(rack_counters),
1658 	    OID_AUTO, "tlp_retran_fail", CTLFLAG_RD,
1659 	    &rack_tlp_retran_fail,
1660 	    "Total number of tail loss probe sending retransmitted data that failed (wait for t3)");
1661 	rack_to_tot = counter_u64_alloc(M_WAITOK);
1662 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1663 	    SYSCTL_CHILDREN(rack_counters),
1664 	    OID_AUTO, "rack_to_tot", CTLFLAG_RD,
1665 	    &rack_to_tot,
1666 	    "Total number of times the rack to expired");
1667 	rack_to_arm_rack = counter_u64_alloc(M_WAITOK);
1668 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1669 	    SYSCTL_CHILDREN(rack_counters),
1670 	    OID_AUTO, "arm_rack", CTLFLAG_RD,
1671 	    &rack_to_arm_rack,
1672 	    "Total number of times the rack timer armed");
1673 	rack_to_arm_tlp = counter_u64_alloc(M_WAITOK);
1674 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1675 	    SYSCTL_CHILDREN(rack_counters),
1676 	    OID_AUTO, "arm_tlp", CTLFLAG_RD,
1677 	    &rack_to_arm_tlp,
1678 	    "Total number of times the tlp timer armed");
1679 	rack_calc_zero = counter_u64_alloc(M_WAITOK);
1680 	rack_calc_nonzero = counter_u64_alloc(M_WAITOK);
1681 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1682 	    SYSCTL_CHILDREN(rack_counters),
1683 	    OID_AUTO, "calc_zero", CTLFLAG_RD,
1684 	    &rack_calc_zero,
1685 	    "Total number of times pacing time worked out to zero");
1686 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1687 	    SYSCTL_CHILDREN(rack_counters),
1688 	    OID_AUTO, "calc_nonzero", CTLFLAG_RD,
1689 	    &rack_calc_nonzero,
1690 	    "Total number of times pacing time worked out to non-zero");
1691 	rack_paced_segments = counter_u64_alloc(M_WAITOK);
1692 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1693 	    SYSCTL_CHILDREN(rack_counters),
1694 	    OID_AUTO, "paced", CTLFLAG_RD,
1695 	    &rack_paced_segments,
1696 	    "Total number of times a segment send caused hptsi");
1697 	rack_unpaced_segments = counter_u64_alloc(M_WAITOK);
1698 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1699 	    SYSCTL_CHILDREN(rack_counters),
1700 	    OID_AUTO, "unpaced", CTLFLAG_RD,
1701 	    &rack_unpaced_segments,
1702 	    "Total number of times a segment did not cause hptsi");
1703 	rack_saw_enobuf = counter_u64_alloc(M_WAITOK);
1704 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1705 	    SYSCTL_CHILDREN(rack_counters),
1706 	    OID_AUTO, "saw_enobufs", CTLFLAG_RD,
1707 	    &rack_saw_enobuf,
1708 	    "Total number of times a sends returned enobuf for non-hdwr paced connections");
1709 	rack_saw_enobuf_hw = counter_u64_alloc(M_WAITOK);
1710 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1711 	    SYSCTL_CHILDREN(rack_counters),
1712 	    OID_AUTO, "saw_enobufs_hw", CTLFLAG_RD,
1713 	    &rack_saw_enobuf_hw,
1714 	    "Total number of times a send returned enobuf for hdwr paced connections");
1715 	rack_saw_enetunreach = counter_u64_alloc(M_WAITOK);
1716 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1717 	    SYSCTL_CHILDREN(rack_counters),
1718 	    OID_AUTO, "saw_enetunreach", CTLFLAG_RD,
1719 	    &rack_saw_enetunreach,
1720 	    "Total number of times a send received a enetunreachable");
1721 	rack_hot_alloc = counter_u64_alloc(M_WAITOK);
1722 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1723 	    SYSCTL_CHILDREN(rack_counters),
1724 	    OID_AUTO, "alloc_hot", CTLFLAG_RD,
1725 	    &rack_hot_alloc,
1726 	    "Total allocations from the top of our list");
1727 	rack_to_alloc = counter_u64_alloc(M_WAITOK);
1728 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1729 	    SYSCTL_CHILDREN(rack_counters),
1730 	    OID_AUTO, "allocs", CTLFLAG_RD,
1731 	    &rack_to_alloc,
1732 	    "Total allocations of tracking structures");
1733 	rack_to_alloc_hard = counter_u64_alloc(M_WAITOK);
1734 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1735 	    SYSCTL_CHILDREN(rack_counters),
1736 	    OID_AUTO, "allochard", CTLFLAG_RD,
1737 	    &rack_to_alloc_hard,
1738 	    "Total allocations done with sleeping the hard way");
1739 	rack_to_alloc_emerg = counter_u64_alloc(M_WAITOK);
1740 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1741 	    SYSCTL_CHILDREN(rack_counters),
1742 	    OID_AUTO, "allocemerg", CTLFLAG_RD,
1743 	    &rack_to_alloc_emerg,
1744 	    "Total allocations done from emergency cache");
1745 	rack_to_alloc_limited = counter_u64_alloc(M_WAITOK);
1746 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1747 	    SYSCTL_CHILDREN(rack_counters),
1748 	    OID_AUTO, "alloc_limited", CTLFLAG_RD,
1749 	    &rack_to_alloc_limited,
1750 	    "Total allocations dropped due to limit");
1751 	rack_alloc_limited_conns = counter_u64_alloc(M_WAITOK);
1752 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1753 	    SYSCTL_CHILDREN(rack_counters),
1754 	    OID_AUTO, "alloc_limited_conns", CTLFLAG_RD,
1755 	    &rack_alloc_limited_conns,
1756 	    "Connections with allocations dropped due to limit");
1757 	rack_split_limited = counter_u64_alloc(M_WAITOK);
1758 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1759 	    SYSCTL_CHILDREN(rack_counters),
1760 	    OID_AUTO, "split_limited", CTLFLAG_RD,
1761 	    &rack_split_limited,
1762 	    "Split allocations dropped due to limit");
1763 
1764 	for (i = 0; i < MAX_NUM_OF_CNTS; i++) {
1765 		char name[32];
1766 		sprintf(name, "cmp_ack_cnt_%d", i);
1767 		rack_proc_comp_ack[i] = counter_u64_alloc(M_WAITOK);
1768 		SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1769 				       SYSCTL_CHILDREN(rack_counters),
1770 				       OID_AUTO, name, CTLFLAG_RD,
1771 				       &rack_proc_comp_ack[i],
1772 				       "Number of compressed acks we processed");
1773 	}
1774 	rack_large_ackcmp = counter_u64_alloc(M_WAITOK);
1775 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1776 	    SYSCTL_CHILDREN(rack_counters),
1777 	    OID_AUTO, "cmp_large_mbufs", CTLFLAG_RD,
1778 	    &rack_large_ackcmp,
1779 	    "Number of TCP connections with large mbuf's for compressed acks");
1780 	rack_small_ackcmp = counter_u64_alloc(M_WAITOK);
1781 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1782 	    SYSCTL_CHILDREN(rack_counters),
1783 	    OID_AUTO, "cmp_small_mbufs", CTLFLAG_RD,
1784 	    &rack_small_ackcmp,
1785 	    "Number of TCP connections with small mbuf's for compressed acks");
1786 #ifdef INVARIANTS
1787 	rack_adjust_map_bw = counter_u64_alloc(M_WAITOK);
1788 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1789 	    SYSCTL_CHILDREN(rack_counters),
1790 	    OID_AUTO, "map_adjust_req", CTLFLAG_RD,
1791 	    &rack_adjust_map_bw,
1792 	    "Number of times we hit the case where the sb went up and down on a sendmap entry");
1793 #endif
1794 	rack_multi_single_eq = counter_u64_alloc(M_WAITOK);
1795 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1796 	    SYSCTL_CHILDREN(rack_counters),
1797 	    OID_AUTO, "cmp_ack_equiv", CTLFLAG_RD,
1798 	    &rack_multi_single_eq,
1799 	    "Number of compressed acks total represented");
1800 	rack_proc_non_comp_ack = counter_u64_alloc(M_WAITOK);
1801 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1802 	    SYSCTL_CHILDREN(rack_counters),
1803 	    OID_AUTO, "cmp_ack_not", CTLFLAG_RD,
1804 	    &rack_proc_non_comp_ack,
1805 	    "Number of non compresseds acks that we processed");
1806 
1807 
1808 	rack_sack_proc_all = counter_u64_alloc(M_WAITOK);
1809 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1810 	    SYSCTL_CHILDREN(rack_counters),
1811 	    OID_AUTO, "sack_long", CTLFLAG_RD,
1812 	    &rack_sack_proc_all,
1813 	    "Total times we had to walk whole list for sack processing");
1814 	rack_sack_proc_restart = counter_u64_alloc(M_WAITOK);
1815 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1816 	    SYSCTL_CHILDREN(rack_counters),
1817 	    OID_AUTO, "sack_restart", CTLFLAG_RD,
1818 	    &rack_sack_proc_restart,
1819 	    "Total times we had to walk whole list due to a restart");
1820 	rack_sack_proc_short = counter_u64_alloc(M_WAITOK);
1821 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1822 	    SYSCTL_CHILDREN(rack_counters),
1823 	    OID_AUTO, "sack_short", CTLFLAG_RD,
1824 	    &rack_sack_proc_short,
1825 	    "Total times we took shortcut for sack processing");
1826 	rack_enter_tlp_calc = counter_u64_alloc(M_WAITOK);
1827 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1828 	    SYSCTL_CHILDREN(rack_counters),
1829 	    OID_AUTO, "tlp_calc_entered", CTLFLAG_RD,
1830 	    &rack_enter_tlp_calc,
1831 	    "Total times we called calc-tlp");
1832 	rack_used_tlpmethod = counter_u64_alloc(M_WAITOK);
1833 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1834 	    SYSCTL_CHILDREN(rack_counters),
1835 	    OID_AUTO, "hit_tlp_method", CTLFLAG_RD,
1836 	    &rack_used_tlpmethod,
1837 	    "Total number of runt sacks");
1838 	rack_used_tlpmethod2 = counter_u64_alloc(M_WAITOK);
1839 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1840 	    SYSCTL_CHILDREN(rack_counters),
1841 	    OID_AUTO, "hit_tlp_method2", CTLFLAG_RD,
1842 	    &rack_used_tlpmethod2,
1843 	    "Total number of times we hit TLP method 2");
1844 	rack_sack_skipped_acked = counter_u64_alloc(M_WAITOK);
1845 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1846 	    SYSCTL_CHILDREN(rack_attack),
1847 	    OID_AUTO, "skipacked", CTLFLAG_RD,
1848 	    &rack_sack_skipped_acked,
1849 	    "Total number of times we skipped previously sacked");
1850 	rack_sack_splits = counter_u64_alloc(M_WAITOK);
1851 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1852 	    SYSCTL_CHILDREN(rack_attack),
1853 	    OID_AUTO, "ofsplit", CTLFLAG_RD,
1854 	    &rack_sack_splits,
1855 	    "Total number of times we did the old fashion tree split");
1856 	rack_progress_drops = counter_u64_alloc(M_WAITOK);
1857 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1858 	    SYSCTL_CHILDREN(rack_counters),
1859 	    OID_AUTO, "prog_drops", CTLFLAG_RD,
1860 	    &rack_progress_drops,
1861 	    "Total number of progress drops");
1862 	rack_input_idle_reduces = counter_u64_alloc(M_WAITOK);
1863 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1864 	    SYSCTL_CHILDREN(rack_counters),
1865 	    OID_AUTO, "idle_reduce_oninput", CTLFLAG_RD,
1866 	    &rack_input_idle_reduces,
1867 	    "Total number of idle reductions on input");
1868 	rack_collapsed_win = counter_u64_alloc(M_WAITOK);
1869 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1870 	    SYSCTL_CHILDREN(rack_counters),
1871 	    OID_AUTO, "collapsed_win", CTLFLAG_RD,
1872 	    &rack_collapsed_win,
1873 	    "Total number of collapsed windows");
1874 	rack_tlp_does_nada = counter_u64_alloc(M_WAITOK);
1875 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1876 	    SYSCTL_CHILDREN(rack_counters),
1877 	    OID_AUTO, "tlp_nada", CTLFLAG_RD,
1878 	    &rack_tlp_does_nada,
1879 	    "Total number of nada tlp calls");
1880 	rack_try_scwnd = counter_u64_alloc(M_WAITOK);
1881 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1882 	    SYSCTL_CHILDREN(rack_counters),
1883 	    OID_AUTO, "tried_scwnd", CTLFLAG_RD,
1884 	    &rack_try_scwnd,
1885 	    "Total number of scwnd attempts");
1886 
1887 	rack_per_timer_hole = counter_u64_alloc(M_WAITOK);
1888 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1889 	    SYSCTL_CHILDREN(rack_counters),
1890 	    OID_AUTO, "timer_hole", CTLFLAG_RD,
1891 	    &rack_per_timer_hole,
1892 	    "Total persists start in timer hole");
1893 
1894 	rack_sbsndptr_wrong = counter_u64_alloc(M_WAITOK);
1895 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1896 	    SYSCTL_CHILDREN(rack_counters),
1897 	    OID_AUTO, "sndptr_wrong", CTLFLAG_RD,
1898 	    &rack_sbsndptr_wrong, "Total number of times the saved sbsndptr was incorret");
1899 	rack_sbsndptr_right = counter_u64_alloc(M_WAITOK);
1900 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1901 	    SYSCTL_CHILDREN(rack_counters),
1902 	    OID_AUTO, "sndptr_right", CTLFLAG_RD,
1903 	    &rack_sbsndptr_right, "Total number of times the saved sbsndptr was corret");
1904 
1905 	COUNTER_ARRAY_ALLOC(rack_out_size, TCP_MSS_ACCT_SIZE, M_WAITOK);
1906 	SYSCTL_ADD_COUNTER_U64_ARRAY(&rack_sysctl_ctx, SYSCTL_CHILDREN(rack_sysctl_root),
1907 	    OID_AUTO, "outsize", CTLFLAG_RD,
1908 	    rack_out_size, TCP_MSS_ACCT_SIZE, "MSS send sizes");
1909 	COUNTER_ARRAY_ALLOC(rack_opts_arry, RACK_OPTS_SIZE, M_WAITOK);
1910 	SYSCTL_ADD_COUNTER_U64_ARRAY(&rack_sysctl_ctx, SYSCTL_CHILDREN(rack_sysctl_root),
1911 	    OID_AUTO, "opts", CTLFLAG_RD,
1912 	    rack_opts_arry, RACK_OPTS_SIZE, "RACK Option Stats");
1913 	SYSCTL_ADD_PROC(&rack_sysctl_ctx,
1914 	    SYSCTL_CHILDREN(rack_sysctl_root),
1915 	    OID_AUTO, "clear", CTLTYPE_UINT | CTLFLAG_RW | CTLFLAG_MPSAFE,
1916 	    &rack_clear_counter, 0, sysctl_rack_clear, "IU", "Clear counters");
1917 }
1918 
1919 static __inline int
1920 rb_map_cmp(struct rack_sendmap *b, struct rack_sendmap *a)
1921 {
1922 	if (SEQ_GEQ(b->r_start, a->r_start) &&
1923 	    SEQ_LT(b->r_start, a->r_end)) {
1924 		/*
1925 		 * The entry b is within the
1926 		 * block a. i.e.:
1927 		 * a --   |-------------|
1928 		 * b --   |----|
1929 		 * <or>
1930 		 * b --       |------|
1931 		 * <or>
1932 		 * b --       |-----------|
1933 		 */
1934 		return (0);
1935 	} else if (SEQ_GEQ(b->r_start, a->r_end)) {
1936 		/*
1937 		 * b falls as either the next
1938 		 * sequence block after a so a
1939 		 * is said to be smaller than b.
1940 		 * i.e:
1941 		 * a --   |------|
1942 		 * b --          |--------|
1943 		 * or
1944 		 * b --              |-----|
1945 		 */
1946 		return (1);
1947 	}
1948 	/*
1949 	 * Whats left is where a is
1950 	 * larger than b. i.e:
1951 	 * a --         |-------|
1952 	 * b --  |---|
1953 	 * or even possibly
1954 	 * b --   |--------------|
1955 	 */
1956 	return (-1);
1957 }
1958 
1959 RB_PROTOTYPE(rack_rb_tree_head, rack_sendmap, r_next, rb_map_cmp);
1960 RB_GENERATE(rack_rb_tree_head, rack_sendmap, r_next, rb_map_cmp);
1961 
1962 static uint32_t
1963 rc_init_window(struct tcp_rack *rack)
1964 {
1965 	uint32_t win;
1966 
1967 	if (rack->rc_init_win == 0) {
1968 		/*
1969 		 * Nothing set by the user, use the system stack
1970 		 * default.
1971 		 */
1972 		return (tcp_compute_initwnd(tcp_maxseg(rack->rc_tp)));
1973 	}
1974 	win = ctf_fixed_maxseg(rack->rc_tp) * rack->rc_init_win;
1975 	return (win);
1976 }
1977 
1978 static uint64_t
1979 rack_get_fixed_pacing_bw(struct tcp_rack *rack)
1980 {
1981 	if (IN_FASTRECOVERY(rack->rc_tp->t_flags))
1982 		return (rack->r_ctl.rc_fixed_pacing_rate_rec);
1983 	else if (rack->r_ctl.cwnd_to_use < rack->rc_tp->snd_ssthresh)
1984 		return (rack->r_ctl.rc_fixed_pacing_rate_ss);
1985 	else
1986 		return (rack->r_ctl.rc_fixed_pacing_rate_ca);
1987 }
1988 
1989 static uint64_t
1990 rack_get_bw(struct tcp_rack *rack)
1991 {
1992 	if (rack->use_fixed_rate) {
1993 		/* Return the fixed pacing rate */
1994 		return (rack_get_fixed_pacing_bw(rack));
1995 	}
1996 	if (rack->r_ctl.gp_bw == 0) {
1997 		/*
1998 		 * We have yet no b/w measurement,
1999 		 * if we have a user set initial bw
2000 		 * return it. If we don't have that and
2001 		 * we have an srtt, use the tcp IW (10) to
2002 		 * calculate a fictional b/w over the SRTT
2003 		 * which is more or less a guess. Note
2004 		 * we don't use our IW from rack on purpose
2005 		 * so if we have like IW=30, we are not
2006 		 * calculating a "huge" b/w.
2007 		 */
2008 		uint64_t bw, srtt;
2009 		if (rack->r_ctl.init_rate)
2010 			return (rack->r_ctl.init_rate);
2011 
2012 		/* Has the user set a max peak rate? */
2013 #ifdef NETFLIX_PEAKRATE
2014 		if (rack->rc_tp->t_maxpeakrate)
2015 			return (rack->rc_tp->t_maxpeakrate);
2016 #endif
2017 		/* Ok lets come up with the IW guess, if we have a srtt */
2018 		if (rack->rc_tp->t_srtt == 0) {
2019 			/*
2020 			 * Go with old pacing method
2021 			 * i.e. burst mitigation only.
2022 			 */
2023 			return (0);
2024 		}
2025 		/* Ok lets get the initial TCP win (not racks) */
2026 		bw = tcp_compute_initwnd(tcp_maxseg(rack->rc_tp));
2027 		srtt = (uint64_t)rack->rc_tp->t_srtt;
2028 		bw *= (uint64_t)USECS_IN_SECOND;
2029 		bw /= srtt;
2030 		if (rack->r_ctl.bw_rate_cap && (bw > rack->r_ctl.bw_rate_cap))
2031 			bw = rack->r_ctl.bw_rate_cap;
2032 		return (bw);
2033 	} else {
2034 		uint64_t bw;
2035 
2036 		if (rack->r_ctl.num_measurements >= RACK_REQ_AVG) {
2037 			/* Averaging is done, we can return the value */
2038 			bw = rack->r_ctl.gp_bw;
2039 		} else {
2040 			/* Still doing initial average must calculate */
2041 			bw = rack->r_ctl.gp_bw / rack->r_ctl.num_measurements;
2042 		}
2043 #ifdef NETFLIX_PEAKRATE
2044 		if ((rack->rc_tp->t_maxpeakrate) &&
2045 		    (bw > rack->rc_tp->t_maxpeakrate)) {
2046 			/* The user has set a peak rate to pace at
2047 			 * don't allow us to pace faster than that.
2048 			 */
2049 			return (rack->rc_tp->t_maxpeakrate);
2050 		}
2051 #endif
2052 		if (rack->r_ctl.bw_rate_cap && (bw > rack->r_ctl.bw_rate_cap))
2053 			bw = rack->r_ctl.bw_rate_cap;
2054 		return (bw);
2055 	}
2056 }
2057 
2058 static uint16_t
2059 rack_get_output_gain(struct tcp_rack *rack, struct rack_sendmap *rsm)
2060 {
2061 	if (rack->use_fixed_rate) {
2062 		return (100);
2063 	} else if (rack->in_probe_rtt && (rsm == NULL))
2064 		return (rack->r_ctl.rack_per_of_gp_probertt);
2065 	else if ((IN_FASTRECOVERY(rack->rc_tp->t_flags) &&
2066 		  rack->r_ctl.rack_per_of_gp_rec)) {
2067 		if (rsm) {
2068 			/* a retransmission always use the recovery rate */
2069 			return (rack->r_ctl.rack_per_of_gp_rec);
2070 		} else if (rack->rack_rec_nonrxt_use_cr) {
2071 			/* Directed to use the configured rate */
2072 			goto configured_rate;
2073 		} else if (rack->rack_no_prr &&
2074 			   (rack->r_ctl.rack_per_of_gp_rec > 100)) {
2075 			/* No PRR, lets just use the b/w estimate only */
2076 			return (100);
2077 		} else {
2078 			/*
2079 			 * Here we may have a non-retransmit but we
2080 			 * have no overrides, so just use the recovery
2081 			 * rate (prr is in effect).
2082 			 */
2083 			return (rack->r_ctl.rack_per_of_gp_rec);
2084 		}
2085 	}
2086 configured_rate:
2087 	/* For the configured rate we look at our cwnd vs the ssthresh */
2088 	if (rack->r_ctl.cwnd_to_use < rack->rc_tp->snd_ssthresh)
2089 		return (rack->r_ctl.rack_per_of_gp_ss);
2090 	else
2091 		return (rack->r_ctl.rack_per_of_gp_ca);
2092 }
2093 
2094 static void
2095 rack_log_dsack_event(struct tcp_rack *rack, uint8_t mod, uint32_t flex4, uint32_t flex5, uint32_t flex6)
2096 {
2097 	/*
2098 	 * Types of logs (mod value)
2099 	 * 1 = dsack_persists reduced by 1 via T-O or fast recovery exit.
2100 	 * 2 = a dsack round begins, persist is reset to 16.
2101 	 * 3 = a dsack round ends
2102 	 * 4 = Dsack option increases rack rtt flex5 is the srtt input, flex6 is thresh
2103 	 * 5 = Socket option set changing the control flags rc_rack_tmr_std_based, rc_rack_use_dsack
2104 	 * 6 = Final rack rtt, flex4 is srtt and flex6 is final limited thresh.
2105 	 */
2106 	if (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
2107 		union tcp_log_stackspecific log;
2108 		struct timeval tv;
2109 
2110 		memset(&log, 0, sizeof(log));
2111 		log.u_bbr.flex1 = rack->rc_rack_tmr_std_based;
2112 		log.u_bbr.flex1 <<= 1;
2113 		log.u_bbr.flex1 |= rack->rc_rack_use_dsack;
2114 		log.u_bbr.flex1 <<= 1;
2115 		log.u_bbr.flex1 |= rack->rc_dsack_round_seen;
2116 		log.u_bbr.flex2 = rack->r_ctl.dsack_round_end;
2117 		log.u_bbr.flex3 = rack->r_ctl.num_dsack;
2118 		log.u_bbr.flex4 = flex4;
2119 		log.u_bbr.flex5 = flex5;
2120 		log.u_bbr.flex6 = flex6;
2121 		log.u_bbr.flex7 = rack->r_ctl.dsack_persist;
2122 		log.u_bbr.flex8 = mod;
2123 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
2124 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
2125 		    &rack->rc_inp->inp_socket->so_rcv,
2126 		    &rack->rc_inp->inp_socket->so_snd,
2127 		    RACK_DSACK_HANDLING, 0,
2128 		    0, &log, false, &tv);
2129 	}
2130 }
2131 
2132 static void
2133 rack_log_hdwr_pacing(struct tcp_rack *rack,
2134 		     uint64_t rate, uint64_t hw_rate, int line,
2135 		     int error, uint16_t mod)
2136 {
2137 	if (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
2138 		union tcp_log_stackspecific log;
2139 		struct timeval tv;
2140 		const struct ifnet *ifp;
2141 
2142 		memset(&log, 0, sizeof(log));
2143 		log.u_bbr.flex1 = ((hw_rate >> 32) & 0x00000000ffffffff);
2144 		log.u_bbr.flex2 = (hw_rate & 0x00000000ffffffff);
2145 		if (rack->r_ctl.crte) {
2146 			ifp = rack->r_ctl.crte->ptbl->rs_ifp;
2147 		} else if (rack->rc_inp->inp_route.ro_nh &&
2148 			   rack->rc_inp->inp_route.ro_nh->nh_ifp) {
2149 			ifp = rack->rc_inp->inp_route.ro_nh->nh_ifp;
2150 		} else
2151 			ifp = NULL;
2152 		if (ifp) {
2153 			log.u_bbr.flex3 = (((uint64_t)ifp  >> 32) & 0x00000000ffffffff);
2154 			log.u_bbr.flex4 = ((uint64_t)ifp & 0x00000000ffffffff);
2155 		}
2156 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
2157 		log.u_bbr.bw_inuse = rate;
2158 		log.u_bbr.flex5 = line;
2159 		log.u_bbr.flex6 = error;
2160 		log.u_bbr.flex7 = mod;
2161 		log.u_bbr.applimited = rack->r_ctl.rc_pace_max_segs;
2162 		log.u_bbr.flex8 = rack->use_fixed_rate;
2163 		log.u_bbr.flex8 <<= 1;
2164 		log.u_bbr.flex8 |= rack->rack_hdrw_pacing;
2165 		log.u_bbr.pkts_out = rack->rc_tp->t_maxseg;
2166 		log.u_bbr.delRate = rack->r_ctl.crte_prev_rate;
2167 		if (rack->r_ctl.crte)
2168 			log.u_bbr.cur_del_rate = rack->r_ctl.crte->rate;
2169 		else
2170 			log.u_bbr.cur_del_rate = 0;
2171 		log.u_bbr.rttProp = rack->r_ctl.last_hw_bw_req;
2172 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
2173 		    &rack->rc_inp->inp_socket->so_rcv,
2174 		    &rack->rc_inp->inp_socket->so_snd,
2175 		    BBR_LOG_HDWR_PACE, 0,
2176 		    0, &log, false, &tv);
2177 	}
2178 }
2179 
2180 static uint64_t
2181 rack_get_output_bw(struct tcp_rack *rack, uint64_t bw, struct rack_sendmap *rsm, int *capped)
2182 {
2183 	/*
2184 	 * We allow rack_per_of_gp_xx to dictate our bw rate we want.
2185 	 */
2186 	uint64_t bw_est, high_rate;
2187 	uint64_t gain;
2188 
2189 	gain = (uint64_t)rack_get_output_gain(rack, rsm);
2190 	bw_est = bw * gain;
2191 	bw_est /= (uint64_t)100;
2192 	/* Never fall below the minimum (def 64kbps) */
2193 	if (bw_est < RACK_MIN_BW)
2194 		bw_est = RACK_MIN_BW;
2195 	if (rack->r_rack_hw_rate_caps) {
2196 		/* Rate caps are in place */
2197 		if (rack->r_ctl.crte != NULL) {
2198 			/* We have a hdwr rate already */
2199 			high_rate = tcp_hw_highest_rate(rack->r_ctl.crte);
2200 			if (bw_est >= high_rate) {
2201 				/* We are capping bw at the highest rate table entry */
2202 				rack_log_hdwr_pacing(rack,
2203 						     bw_est, high_rate, __LINE__,
2204 						     0, 3);
2205 				bw_est = high_rate;
2206 				if (capped)
2207 					*capped = 1;
2208 			}
2209 		} else if ((rack->rack_hdrw_pacing == 0) &&
2210 			   (rack->rack_hdw_pace_ena) &&
2211 			   (rack->rack_attempt_hdwr_pace == 0) &&
2212 			   (rack->rc_inp->inp_route.ro_nh != NULL) &&
2213 			   (rack->rc_inp->inp_route.ro_nh->nh_ifp != NULL)) {
2214 			/*
2215 			 * Special case, we have not yet attempted hardware
2216 			 * pacing, and yet we may, when we do, find out if we are
2217 			 * above the highest rate. We need to know the maxbw for the interface
2218 			 * in question (if it supports ratelimiting). We get back
2219 			 * a 0, if the interface is not found in the RL lists.
2220 			 */
2221 			high_rate = tcp_hw_highest_rate_ifp(rack->rc_inp->inp_route.ro_nh->nh_ifp, rack->rc_inp);
2222 			if (high_rate) {
2223 				/* Yep, we have a rate is it above this rate? */
2224 				if (bw_est > high_rate) {
2225 					bw_est = high_rate;
2226 					if (capped)
2227 						*capped = 1;
2228 				}
2229 			}
2230 		}
2231 	}
2232 	return (bw_est);
2233 }
2234 
2235 static void
2236 rack_log_retran_reason(struct tcp_rack *rack, struct rack_sendmap *rsm, uint32_t tsused, uint32_t thresh, int mod)
2237 {
2238 	if (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
2239 		union tcp_log_stackspecific log;
2240 		struct timeval tv;
2241 
2242 		if ((mod != 1) && (rack_verbose_logging == 0)) {
2243 			/*
2244 			 * We get 3 values currently for mod
2245 			 * 1 - We are retransmitting and this tells the reason.
2246 			 * 2 - We are clearing a dup-ack count.
2247 			 * 3 - We are incrementing a dup-ack count.
2248 			 *
2249 			 * The clear/increment are only logged
2250 			 * if you have BBverbose on.
2251 			 */
2252 			return;
2253 		}
2254 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
2255 		log.u_bbr.flex1 = tsused;
2256 		log.u_bbr.flex2 = thresh;
2257 		log.u_bbr.flex3 = rsm->r_flags;
2258 		log.u_bbr.flex4 = rsm->r_dupack;
2259 		log.u_bbr.flex5 = rsm->r_start;
2260 		log.u_bbr.flex6 = rsm->r_end;
2261 		log.u_bbr.flex8 = mod;
2262 		log.u_bbr.inhpts = rack->rc_inp->inp_in_hpts;
2263 		log.u_bbr.ininput = rack->rc_inp->inp_in_input;
2264 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
2265 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
2266 		log.u_bbr.pkts_out = rack->r_ctl.rc_out_at_rto;
2267 		log.u_bbr.delivered = rack->r_ctl.rc_snd_max_at_rto;
2268 		log.u_bbr.pacing_gain = rack->r_must_retran;
2269 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
2270 		    &rack->rc_inp->inp_socket->so_rcv,
2271 		    &rack->rc_inp->inp_socket->so_snd,
2272 		    BBR_LOG_SETTINGS_CHG, 0,
2273 		    0, &log, false, &tv);
2274 	}
2275 }
2276 
2277 static void
2278 rack_log_to_start(struct tcp_rack *rack, uint32_t cts, uint32_t to, int32_t slot, uint8_t which)
2279 {
2280 	if (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
2281 		union tcp_log_stackspecific log;
2282 		struct timeval tv;
2283 
2284 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
2285 		log.u_bbr.flex1 = rack->rc_tp->t_srtt;
2286 		log.u_bbr.flex2 = to;
2287 		log.u_bbr.flex3 = rack->r_ctl.rc_hpts_flags;
2288 		log.u_bbr.flex4 = slot;
2289 		log.u_bbr.flex5 = rack->rc_inp->inp_hptsslot;
2290 		log.u_bbr.flex6 = rack->rc_tp->t_rxtcur;
2291 		log.u_bbr.flex7 = rack->rc_in_persist;
2292 		log.u_bbr.flex8 = which;
2293 		if (rack->rack_no_prr)
2294 			log.u_bbr.pkts_out = 0;
2295 		else
2296 			log.u_bbr.pkts_out = rack->r_ctl.rc_prr_sndcnt;
2297 		log.u_bbr.inhpts = rack->rc_inp->inp_in_hpts;
2298 		log.u_bbr.ininput = rack->rc_inp->inp_in_input;
2299 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
2300 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
2301 		log.u_bbr.pkts_out = rack->r_ctl.rc_out_at_rto;
2302 		log.u_bbr.delivered = rack->r_ctl.rc_snd_max_at_rto;
2303 		log.u_bbr.pacing_gain = rack->r_must_retran;
2304 		log.u_bbr.lt_epoch = rack->rc_tp->t_rxtshift;
2305 		log.u_bbr.lost = rack_rto_min;
2306 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
2307 		    &rack->rc_inp->inp_socket->so_rcv,
2308 		    &rack->rc_inp->inp_socket->so_snd,
2309 		    BBR_LOG_TIMERSTAR, 0,
2310 		    0, &log, false, &tv);
2311 	}
2312 }
2313 
2314 static void
2315 rack_log_to_event(struct tcp_rack *rack, int32_t to_num, struct rack_sendmap *rsm)
2316 {
2317 	if (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
2318 		union tcp_log_stackspecific log;
2319 		struct timeval tv;
2320 
2321 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
2322 		log.u_bbr.inhpts = rack->rc_inp->inp_in_hpts;
2323 		log.u_bbr.ininput = rack->rc_inp->inp_in_input;
2324 		log.u_bbr.flex8 = to_num;
2325 		log.u_bbr.flex1 = rack->r_ctl.rc_rack_min_rtt;
2326 		log.u_bbr.flex2 = rack->rc_rack_rtt;
2327 		if (rsm == NULL)
2328 			log.u_bbr.flex3 = 0;
2329 		else
2330 			log.u_bbr.flex3 = rsm->r_end - rsm->r_start;
2331 		if (rack->rack_no_prr)
2332 			log.u_bbr.flex5 = 0;
2333 		else
2334 			log.u_bbr.flex5 = rack->r_ctl.rc_prr_sndcnt;
2335 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
2336 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
2337 		log.u_bbr.pkts_out = rack->r_ctl.rc_out_at_rto;
2338 		log.u_bbr.delivered = rack->r_ctl.rc_snd_max_at_rto;
2339 		log.u_bbr.pacing_gain = rack->r_must_retran;
2340 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
2341 		    &rack->rc_inp->inp_socket->so_rcv,
2342 		    &rack->rc_inp->inp_socket->so_snd,
2343 		    BBR_LOG_RTO, 0,
2344 		    0, &log, false, &tv);
2345 	}
2346 }
2347 
2348 static void
2349 rack_log_map_chg(struct tcpcb *tp, struct tcp_rack *rack,
2350 		 struct rack_sendmap *prev,
2351 		 struct rack_sendmap *rsm,
2352 		 struct rack_sendmap *next,
2353 		 int flag, uint32_t th_ack, int line)
2354 {
2355 	if (rack_verbose_logging && (tp->t_logstate != TCP_LOG_STATE_OFF)) {
2356 		union tcp_log_stackspecific log;
2357 		struct timeval tv;
2358 
2359 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
2360 		log.u_bbr.flex8 = flag;
2361 		log.u_bbr.inhpts = rack->rc_inp->inp_in_hpts;
2362 		log.u_bbr.ininput = rack->rc_inp->inp_in_input;
2363 		log.u_bbr.cur_del_rate = (uint64_t)prev;
2364 		log.u_bbr.delRate = (uint64_t)rsm;
2365 		log.u_bbr.rttProp = (uint64_t)next;
2366 		log.u_bbr.flex7 = 0;
2367 		if (prev) {
2368 			log.u_bbr.flex1 = prev->r_start;
2369 			log.u_bbr.flex2 = prev->r_end;
2370 			log.u_bbr.flex7 |= 0x4;
2371 		}
2372 		if (rsm) {
2373 			log.u_bbr.flex3 = rsm->r_start;
2374 			log.u_bbr.flex4 = rsm->r_end;
2375 			log.u_bbr.flex7 |= 0x2;
2376 		}
2377 		if (next) {
2378 			log.u_bbr.flex5 = next->r_start;
2379 			log.u_bbr.flex6 = next->r_end;
2380 			log.u_bbr.flex7 |= 0x1;
2381 		}
2382 		log.u_bbr.applimited = line;
2383 		log.u_bbr.pkts_out = th_ack;
2384 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
2385 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
2386 		if (rack->rack_no_prr)
2387 			log.u_bbr.lost = 0;
2388 		else
2389 			log.u_bbr.lost = rack->r_ctl.rc_prr_sndcnt;
2390 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
2391 		    &rack->rc_inp->inp_socket->so_rcv,
2392 		    &rack->rc_inp->inp_socket->so_snd,
2393 		    TCP_LOG_MAPCHG, 0,
2394 		    0, &log, false, &tv);
2395 	}
2396 }
2397 
2398 static void
2399 rack_log_rtt_upd(struct tcpcb *tp, struct tcp_rack *rack, uint32_t t, uint32_t len,
2400 		 struct rack_sendmap *rsm, int conf)
2401 {
2402 	if (tp->t_logstate != TCP_LOG_STATE_OFF) {
2403 		union tcp_log_stackspecific log;
2404 		struct timeval tv;
2405 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
2406 		log.u_bbr.inhpts = rack->rc_inp->inp_in_hpts;
2407 		log.u_bbr.ininput = rack->rc_inp->inp_in_input;
2408 		log.u_bbr.flex1 = t;
2409 		log.u_bbr.flex2 = len;
2410 		log.u_bbr.flex3 = rack->r_ctl.rc_rack_min_rtt;
2411 		log.u_bbr.flex4 = rack->r_ctl.rack_rs.rs_rtt_lowest;
2412 		log.u_bbr.flex5 = rack->r_ctl.rack_rs.rs_rtt_highest;
2413 		log.u_bbr.flex6 = rack->r_ctl.rack_rs.rs_us_rtrcnt;
2414 		log.u_bbr.flex7 = conf;
2415 		log.u_bbr.rttProp = (uint64_t)rack->r_ctl.rack_rs.rs_rtt_tot;
2416 		log.u_bbr.flex8 = rack->r_ctl.rc_rate_sample_method;
2417 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
2418 		log.u_bbr.delivered = rack->r_ctl.rack_rs.rs_us_rtrcnt;
2419 		log.u_bbr.pkts_out = rack->r_ctl.rack_rs.rs_flags;
2420 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
2421 		if (rsm) {
2422 			log.u_bbr.pkt_epoch = rsm->r_start;
2423 			log.u_bbr.lost = rsm->r_end;
2424 			log.u_bbr.cwnd_gain = rsm->r_rtr_cnt;
2425 			log.u_bbr.pacing_gain = rsm->r_flags;
2426 		} else {
2427 			/* Its a SYN */
2428 			log.u_bbr.pkt_epoch = rack->rc_tp->iss;
2429 			log.u_bbr.lost = 0;
2430 			log.u_bbr.cwnd_gain = 0;
2431 			log.u_bbr.pacing_gain = 0;
2432 		}
2433 		/* Write out general bits of interest rrs here */
2434 		log.u_bbr.use_lt_bw = rack->rc_highly_buffered;
2435 		log.u_bbr.use_lt_bw <<= 1;
2436 		log.u_bbr.use_lt_bw |= rack->forced_ack;
2437 		log.u_bbr.use_lt_bw <<= 1;
2438 		log.u_bbr.use_lt_bw |= rack->rc_gp_dyn_mul;
2439 		log.u_bbr.use_lt_bw <<= 1;
2440 		log.u_bbr.use_lt_bw |= rack->in_probe_rtt;
2441 		log.u_bbr.use_lt_bw <<= 1;
2442 		log.u_bbr.use_lt_bw |= rack->measure_saw_probe_rtt;
2443 		log.u_bbr.use_lt_bw <<= 1;
2444 		log.u_bbr.use_lt_bw |= rack->app_limited_needs_set;
2445 		log.u_bbr.use_lt_bw <<= 1;
2446 		log.u_bbr.use_lt_bw |= rack->rc_gp_filled;
2447 		log.u_bbr.use_lt_bw <<= 1;
2448 		log.u_bbr.use_lt_bw |= rack->rc_dragged_bottom;
2449 		log.u_bbr.applimited = rack->r_ctl.rc_target_probertt_flight;
2450 		log.u_bbr.epoch = rack->r_ctl.rc_time_probertt_starts;
2451 		log.u_bbr.lt_epoch = rack->r_ctl.rc_time_probertt_entered;
2452 		log.u_bbr.cur_del_rate = rack->r_ctl.rc_lower_rtt_us_cts;
2453 		log.u_bbr.delRate = rack->r_ctl.rc_gp_srtt;
2454 		log.u_bbr.bw_inuse = tcp_tv_to_usectick(&rack->r_ctl.act_rcv_time);
2455 		log.u_bbr.bw_inuse <<= 32;
2456 		if (rsm)
2457 			log.u_bbr.bw_inuse |= ((uint32_t)rsm->r_tim_lastsent[(rsm->r_rtr_cnt-1)]);
2458 		TCP_LOG_EVENTP(tp, NULL,
2459 		    &rack->rc_inp->inp_socket->so_rcv,
2460 		    &rack->rc_inp->inp_socket->so_snd,
2461 		    BBR_LOG_BBRRTT, 0,
2462 		    0, &log, false, &tv);
2463 
2464 
2465 	}
2466 }
2467 
2468 static void
2469 rack_log_rtt_sample(struct tcp_rack *rack, uint32_t rtt)
2470 {
2471 	/*
2472 	 * Log the rtt sample we are
2473 	 * applying to the srtt algorithm in
2474 	 * useconds.
2475 	 */
2476 	if (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
2477 		union tcp_log_stackspecific log;
2478 		struct timeval tv;
2479 
2480 		/* Convert our ms to a microsecond */
2481 		memset(&log, 0, sizeof(log));
2482 		log.u_bbr.flex1 = rtt;
2483 		log.u_bbr.flex2 = rack->r_ctl.ack_count;
2484 		log.u_bbr.flex3 = rack->r_ctl.sack_count;
2485 		log.u_bbr.flex4 = rack->r_ctl.sack_noextra_move;
2486 		log.u_bbr.flex5 = rack->r_ctl.sack_moved_extra;
2487 		log.u_bbr.flex6 = rack->rc_tp->t_rxtcur;
2488 		log.u_bbr.flex7 = 1;
2489 		log.u_bbr.flex8 = rack->sack_attack_disable;
2490 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
2491 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
2492 		log.u_bbr.pkts_out = rack->r_ctl.rc_out_at_rto;
2493 		log.u_bbr.delivered = rack->r_ctl.rc_snd_max_at_rto;
2494 		log.u_bbr.pacing_gain = rack->r_must_retran;
2495 		/*
2496 		 * We capture in delRate the upper 32 bits as
2497 		 * the confidence level we had declared, and the
2498 		 * lower 32 bits as the actual RTT using the arrival
2499 		 * timestamp.
2500 		 */
2501 		log.u_bbr.delRate = rack->r_ctl.rack_rs.confidence;
2502 		log.u_bbr.delRate <<= 32;
2503 		log.u_bbr.delRate |= rack->r_ctl.rack_rs.rs_us_rtt;
2504 		/* Lets capture all the things that make up t_rtxcur */
2505 		log.u_bbr.applimited = rack_rto_min;
2506 		log.u_bbr.epoch = rack_rto_max;
2507 		log.u_bbr.lt_epoch = rack->r_ctl.timer_slop;
2508 		log.u_bbr.lost = rack_rto_min;
2509 		log.u_bbr.pkt_epoch = TICKS_2_USEC(tcp_rexmit_slop);
2510 		log.u_bbr.rttProp = RACK_REXMTVAL(rack->rc_tp);
2511 		log.u_bbr.bw_inuse = rack->r_ctl.act_rcv_time.tv_sec;
2512 		log.u_bbr.bw_inuse *= HPTS_USEC_IN_SEC;
2513 		log.u_bbr.bw_inuse += rack->r_ctl.act_rcv_time.tv_usec;
2514 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
2515 		    &rack->rc_inp->inp_socket->so_rcv,
2516 		    &rack->rc_inp->inp_socket->so_snd,
2517 		    TCP_LOG_RTT, 0,
2518 		    0, &log, false, &tv);
2519 	}
2520 }
2521 
2522 static void
2523 rack_log_rtt_sample_calc(struct tcp_rack *rack, uint32_t rtt, uint32_t send_time, uint32_t ack_time, int where)
2524 {
2525 	if (rack_verbose_logging && (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF)) {
2526 		union tcp_log_stackspecific log;
2527 		struct timeval tv;
2528 
2529 		/* Convert our ms to a microsecond */
2530 		memset(&log, 0, sizeof(log));
2531 		log.u_bbr.flex1 = rtt;
2532 		log.u_bbr.flex2 = send_time;
2533 		log.u_bbr.flex3 = ack_time;
2534 		log.u_bbr.flex4 = where;
2535 		log.u_bbr.flex7 = 2;
2536 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
2537 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
2538 		    &rack->rc_inp->inp_socket->so_rcv,
2539 		    &rack->rc_inp->inp_socket->so_snd,
2540 		    TCP_LOG_RTT, 0,
2541 		    0, &log, false, &tv);
2542 	}
2543 }
2544 
2545 
2546 
2547 static inline void
2548 rack_log_progress_event(struct tcp_rack *rack, struct tcpcb *tp, uint32_t tick,  int event, int line)
2549 {
2550 	if (rack_verbose_logging && (tp->t_logstate != TCP_LOG_STATE_OFF)) {
2551 		union tcp_log_stackspecific log;
2552 		struct timeval tv;
2553 
2554 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
2555 		log.u_bbr.inhpts = rack->rc_inp->inp_in_hpts;
2556 		log.u_bbr.ininput = rack->rc_inp->inp_in_input;
2557 		log.u_bbr.flex1 = line;
2558 		log.u_bbr.flex2 = tick;
2559 		log.u_bbr.flex3 = tp->t_maxunacktime;
2560 		log.u_bbr.flex4 = tp->t_acktime;
2561 		log.u_bbr.flex8 = event;
2562 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
2563 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
2564 		log.u_bbr.pkts_out = rack->r_ctl.rc_out_at_rto;
2565 		log.u_bbr.delivered = rack->r_ctl.rc_snd_max_at_rto;
2566 		log.u_bbr.pacing_gain = rack->r_must_retran;
2567 		TCP_LOG_EVENTP(tp, NULL,
2568 		    &rack->rc_inp->inp_socket->so_rcv,
2569 		    &rack->rc_inp->inp_socket->so_snd,
2570 		    BBR_LOG_PROGRESS, 0,
2571 		    0, &log, false, &tv);
2572 	}
2573 }
2574 
2575 static void
2576 rack_log_type_bbrsnd(struct tcp_rack *rack, uint32_t len, uint32_t slot, uint32_t cts, struct timeval *tv)
2577 {
2578 	if (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
2579 		union tcp_log_stackspecific log;
2580 
2581 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
2582 		log.u_bbr.inhpts = rack->rc_inp->inp_in_hpts;
2583 		log.u_bbr.ininput = rack->rc_inp->inp_in_input;
2584 		log.u_bbr.flex1 = slot;
2585 		if (rack->rack_no_prr)
2586 			log.u_bbr.flex2 = 0;
2587 		else
2588 			log.u_bbr.flex2 = rack->r_ctl.rc_prr_sndcnt;
2589 		log.u_bbr.flex7 = (0x0000ffff & rack->r_ctl.rc_hpts_flags);
2590 		log.u_bbr.flex8 = rack->rc_in_persist;
2591 		log.u_bbr.timeStamp = cts;
2592 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
2593 		log.u_bbr.pkts_out = rack->r_ctl.rc_out_at_rto;
2594 		log.u_bbr.delivered = rack->r_ctl.rc_snd_max_at_rto;
2595 		log.u_bbr.pacing_gain = rack->r_must_retran;
2596 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
2597 		    &rack->rc_inp->inp_socket->so_rcv,
2598 		    &rack->rc_inp->inp_socket->so_snd,
2599 		    BBR_LOG_BBRSND, 0,
2600 		    0, &log, false, tv);
2601 	}
2602 }
2603 
2604 static void
2605 rack_log_doseg_done(struct tcp_rack *rack, uint32_t cts, int32_t nxt_pkt, int32_t did_out, int way_out, int nsegs)
2606 {
2607 	if (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
2608 		union tcp_log_stackspecific log;
2609 		struct timeval tv;
2610 
2611 		memset(&log, 0, sizeof(log));
2612 		log.u_bbr.flex1 = did_out;
2613 		log.u_bbr.flex2 = nxt_pkt;
2614 		log.u_bbr.flex3 = way_out;
2615 		log.u_bbr.flex4 = rack->r_ctl.rc_hpts_flags;
2616 		if (rack->rack_no_prr)
2617 			log.u_bbr.flex5 = 0;
2618 		else
2619 			log.u_bbr.flex5 = rack->r_ctl.rc_prr_sndcnt;
2620 		log.u_bbr.flex6 = nsegs;
2621 		log.u_bbr.applimited = rack->r_ctl.rc_pace_min_segs;
2622 		log.u_bbr.flex7 = rack->rc_ack_can_sendout_data;	/* Do we have ack-can-send set */
2623 		log.u_bbr.flex7 <<= 1;
2624 		log.u_bbr.flex7 |= rack->r_fast_output;	/* is fast output primed */
2625 		log.u_bbr.flex7 <<= 1;
2626 		log.u_bbr.flex7 |= rack->r_wanted_output;	/* Do we want output */
2627 		log.u_bbr.flex8 = rack->rc_in_persist;
2628 		log.u_bbr.inhpts = rack->rc_inp->inp_in_hpts;
2629 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
2630 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
2631 		log.u_bbr.use_lt_bw = rack->r_ent_rec_ns;
2632 		log.u_bbr.use_lt_bw <<= 1;
2633 		log.u_bbr.use_lt_bw |= rack->r_might_revert;
2634 		log.u_bbr.pkts_out = rack->r_ctl.rc_out_at_rto;
2635 		log.u_bbr.delivered = rack->r_ctl.rc_snd_max_at_rto;
2636 		log.u_bbr.pacing_gain = rack->r_must_retran;
2637 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
2638 		    &rack->rc_inp->inp_socket->so_rcv,
2639 		    &rack->rc_inp->inp_socket->so_snd,
2640 		    BBR_LOG_DOSEG_DONE, 0,
2641 		    0, &log, false, &tv);
2642 	}
2643 }
2644 
2645 static void
2646 rack_log_type_pacing_sizes(struct tcpcb *tp, struct tcp_rack *rack, uint32_t arg1, uint32_t arg2, uint32_t arg3, uint8_t frm)
2647 {
2648 	if (tp->t_logstate != TCP_LOG_STATE_OFF) {
2649 		union tcp_log_stackspecific log;
2650 		struct timeval tv;
2651 		uint32_t cts;
2652 
2653 		memset(&log, 0, sizeof(log));
2654 		cts = tcp_get_usecs(&tv);
2655 		log.u_bbr.flex1 = rack->r_ctl.rc_pace_min_segs;
2656 		log.u_bbr.flex3 = rack->r_ctl.rc_pace_max_segs;
2657 		log.u_bbr.flex4 = arg1;
2658 		log.u_bbr.flex5 = arg2;
2659 		log.u_bbr.flex6 = arg3;
2660 		log.u_bbr.flex8 = frm;
2661 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
2662 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
2663 		log.u_bbr.pkts_out = rack->r_ctl.rc_out_at_rto;
2664 		log.u_bbr.applimited = rack->r_ctl.rc_sacked;
2665 		log.u_bbr.delivered = rack->r_ctl.rc_snd_max_at_rto;
2666 		log.u_bbr.pacing_gain = rack->r_must_retran;
2667 		TCP_LOG_EVENTP(tp, NULL,
2668 		    &tp->t_inpcb->inp_socket->so_rcv,
2669 		    &tp->t_inpcb->inp_socket->so_snd,
2670 		    TCP_HDWR_PACE_SIZE, 0,
2671 		    0, &log, false, &tv);
2672 	}
2673 }
2674 
2675 static void
2676 rack_log_type_just_return(struct tcp_rack *rack, uint32_t cts, uint32_t tlen, uint32_t slot,
2677 			  uint8_t hpts_calling, int reason, uint32_t cwnd_to_use)
2678 {
2679 	if (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
2680 		union tcp_log_stackspecific log;
2681 		struct timeval tv;
2682 
2683 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
2684 		log.u_bbr.inhpts = rack->rc_inp->inp_in_hpts;
2685 		log.u_bbr.ininput = rack->rc_inp->inp_in_input;
2686 		log.u_bbr.flex1 = slot;
2687 		log.u_bbr.flex2 = rack->r_ctl.rc_hpts_flags;
2688 		log.u_bbr.flex4 = reason;
2689 		if (rack->rack_no_prr)
2690 			log.u_bbr.flex5 = 0;
2691 		else
2692 			log.u_bbr.flex5 = rack->r_ctl.rc_prr_sndcnt;
2693 		log.u_bbr.flex7 = hpts_calling;
2694 		log.u_bbr.flex8 = rack->rc_in_persist;
2695 		log.u_bbr.lt_epoch = cwnd_to_use;
2696 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
2697 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
2698 		log.u_bbr.pkts_out = rack->r_ctl.rc_out_at_rto;
2699 		log.u_bbr.delivered = rack->r_ctl.rc_snd_max_at_rto;
2700 		log.u_bbr.pacing_gain = rack->r_must_retran;
2701 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
2702 		    &rack->rc_inp->inp_socket->so_rcv,
2703 		    &rack->rc_inp->inp_socket->so_snd,
2704 		    BBR_LOG_JUSTRET, 0,
2705 		    tlen, &log, false, &tv);
2706 	}
2707 }
2708 
2709 static void
2710 rack_log_to_cancel(struct tcp_rack *rack, int32_t hpts_removed, int line, uint32_t us_cts,
2711 		   struct timeval *tv, uint32_t flags_on_entry)
2712 {
2713 	if (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
2714 		union tcp_log_stackspecific log;
2715 
2716 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
2717 		log.u_bbr.inhpts = rack->rc_inp->inp_in_hpts;
2718 		log.u_bbr.ininput = rack->rc_inp->inp_in_input;
2719 		log.u_bbr.flex1 = line;
2720 		log.u_bbr.flex2 = rack->r_ctl.rc_last_output_to;
2721 		log.u_bbr.flex3 = flags_on_entry;
2722 		log.u_bbr.flex4 = us_cts;
2723 		if (rack->rack_no_prr)
2724 			log.u_bbr.flex5 = 0;
2725 		else
2726 			log.u_bbr.flex5 = rack->r_ctl.rc_prr_sndcnt;
2727 		log.u_bbr.flex6 = rack->rc_tp->t_rxtcur;
2728 		log.u_bbr.flex7 = hpts_removed;
2729 		log.u_bbr.flex8 = 1;
2730 		log.u_bbr.applimited = rack->r_ctl.rc_hpts_flags;
2731 		log.u_bbr.timeStamp = us_cts;
2732 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
2733 		log.u_bbr.pkts_out = rack->r_ctl.rc_out_at_rto;
2734 		log.u_bbr.delivered = rack->r_ctl.rc_snd_max_at_rto;
2735 		log.u_bbr.pacing_gain = rack->r_must_retran;
2736 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
2737 		    &rack->rc_inp->inp_socket->so_rcv,
2738 		    &rack->rc_inp->inp_socket->so_snd,
2739 		    BBR_LOG_TIMERCANC, 0,
2740 		    0, &log, false, tv);
2741 	}
2742 }
2743 
2744 static void
2745 rack_log_alt_to_to_cancel(struct tcp_rack *rack,
2746 			  uint32_t flex1, uint32_t flex2,
2747 			  uint32_t flex3, uint32_t flex4,
2748 			  uint32_t flex5, uint32_t flex6,
2749 			  uint16_t flex7, uint8_t mod)
2750 {
2751 	if (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
2752 		union tcp_log_stackspecific log;
2753 		struct timeval tv;
2754 
2755 		if (mod == 1) {
2756 			/* No you can't use 1, its for the real to cancel */
2757 			return;
2758 		}
2759 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
2760 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
2761 		log.u_bbr.flex1 = flex1;
2762 		log.u_bbr.flex2 = flex2;
2763 		log.u_bbr.flex3 = flex3;
2764 		log.u_bbr.flex4 = flex4;
2765 		log.u_bbr.flex5 = flex5;
2766 		log.u_bbr.flex6 = flex6;
2767 		log.u_bbr.flex7 = flex7;
2768 		log.u_bbr.flex8 = mod;
2769 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
2770 		    &rack->rc_inp->inp_socket->so_rcv,
2771 		    &rack->rc_inp->inp_socket->so_snd,
2772 		    BBR_LOG_TIMERCANC, 0,
2773 		    0, &log, false, &tv);
2774 	}
2775 }
2776 
2777 static void
2778 rack_log_to_processing(struct tcp_rack *rack, uint32_t cts, int32_t ret, int32_t timers)
2779 {
2780 	if (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
2781 		union tcp_log_stackspecific log;
2782 		struct timeval tv;
2783 
2784 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
2785 		log.u_bbr.flex1 = timers;
2786 		log.u_bbr.flex2 = ret;
2787 		log.u_bbr.flex3 = rack->r_ctl.rc_timer_exp;
2788 		log.u_bbr.flex4 = rack->r_ctl.rc_hpts_flags;
2789 		log.u_bbr.flex5 = cts;
2790 		if (rack->rack_no_prr)
2791 			log.u_bbr.flex6 = 0;
2792 		else
2793 			log.u_bbr.flex6 = rack->r_ctl.rc_prr_sndcnt;
2794 		log.u_bbr.pkts_out = rack->r_ctl.rc_out_at_rto;
2795 		log.u_bbr.delivered = rack->r_ctl.rc_snd_max_at_rto;
2796 		log.u_bbr.pacing_gain = rack->r_must_retran;
2797 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
2798 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
2799 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
2800 		    &rack->rc_inp->inp_socket->so_rcv,
2801 		    &rack->rc_inp->inp_socket->so_snd,
2802 		    BBR_LOG_TO_PROCESS, 0,
2803 		    0, &log, false, &tv);
2804 	}
2805 }
2806 
2807 static void
2808 rack_log_to_prr(struct tcp_rack *rack, int frm, int orig_cwnd)
2809 {
2810 	if (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
2811 		union tcp_log_stackspecific log;
2812 		struct timeval tv;
2813 
2814 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
2815 		log.u_bbr.flex1 = rack->r_ctl.rc_prr_out;
2816 		log.u_bbr.flex2 = rack->r_ctl.rc_prr_recovery_fs;
2817 		if (rack->rack_no_prr)
2818 			log.u_bbr.flex3 = 0;
2819 		else
2820 			log.u_bbr.flex3 = rack->r_ctl.rc_prr_sndcnt;
2821 		log.u_bbr.flex4 = rack->r_ctl.rc_prr_delivered;
2822 		log.u_bbr.flex5 = rack->r_ctl.rc_sacked;
2823 		log.u_bbr.flex6 = rack->r_ctl.rc_holes_rxt;
2824 		log.u_bbr.flex8 = frm;
2825 		log.u_bbr.pkts_out = orig_cwnd;
2826 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
2827 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
2828 		log.u_bbr.use_lt_bw = rack->r_ent_rec_ns;
2829 		log.u_bbr.use_lt_bw <<= 1;
2830 		log.u_bbr.use_lt_bw |= rack->r_might_revert;
2831 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
2832 		    &rack->rc_inp->inp_socket->so_rcv,
2833 		    &rack->rc_inp->inp_socket->so_snd,
2834 		    BBR_LOG_BBRUPD, 0,
2835 		    0, &log, false, &tv);
2836 	}
2837 }
2838 
2839 #ifdef NETFLIX_EXP_DETECTION
2840 static void
2841 rack_log_sad(struct tcp_rack *rack, int event)
2842 {
2843 	if (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
2844 		union tcp_log_stackspecific log;
2845 		struct timeval tv;
2846 
2847 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
2848 		log.u_bbr.flex1 = rack->r_ctl.sack_count;
2849 		log.u_bbr.flex2 = rack->r_ctl.ack_count;
2850 		log.u_bbr.flex3 = rack->r_ctl.sack_moved_extra;
2851 		log.u_bbr.flex4 = rack->r_ctl.sack_noextra_move;
2852 		log.u_bbr.flex5 = rack->r_ctl.rc_num_maps_alloced;
2853 		log.u_bbr.flex6 = tcp_sack_to_ack_thresh;
2854 		log.u_bbr.pkts_out = tcp_sack_to_move_thresh;
2855 		log.u_bbr.lt_epoch = (tcp_force_detection << 8);
2856 		log.u_bbr.lt_epoch |= rack->do_detection;
2857 		log.u_bbr.applimited = tcp_map_minimum;
2858 		log.u_bbr.flex7 = rack->sack_attack_disable;
2859 		log.u_bbr.flex8 = event;
2860 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
2861 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
2862 		log.u_bbr.delivered = tcp_sad_decay_val;
2863 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
2864 		    &rack->rc_inp->inp_socket->so_rcv,
2865 		    &rack->rc_inp->inp_socket->so_snd,
2866 		    TCP_SAD_DETECTION, 0,
2867 		    0, &log, false, &tv);
2868 	}
2869 }
2870 #endif
2871 
2872 static void
2873 rack_counter_destroy(void)
2874 {
2875 	int i;
2876 
2877 	counter_u64_free(rack_fto_send);
2878 	counter_u64_free(rack_fto_rsm_send);
2879 	counter_u64_free(rack_nfto_resend);
2880 	counter_u64_free(rack_hw_pace_init_fail);
2881 	counter_u64_free(rack_hw_pace_lost);
2882 	counter_u64_free(rack_non_fto_send);
2883 	counter_u64_free(rack_extended_rfo);
2884 	counter_u64_free(rack_ack_total);
2885 	counter_u64_free(rack_express_sack);
2886 	counter_u64_free(rack_sack_total);
2887 	counter_u64_free(rack_move_none);
2888 	counter_u64_free(rack_move_some);
2889 	counter_u64_free(rack_sack_attacks_detected);
2890 	counter_u64_free(rack_sack_attacks_reversed);
2891 	counter_u64_free(rack_sack_used_next_merge);
2892 	counter_u64_free(rack_sack_used_prev_merge);
2893 	counter_u64_free(rack_badfr);
2894 	counter_u64_free(rack_badfr_bytes);
2895 	counter_u64_free(rack_rtm_prr_retran);
2896 	counter_u64_free(rack_rtm_prr_newdata);
2897 	counter_u64_free(rack_timestamp_mismatch);
2898 	counter_u64_free(rack_find_high);
2899 	counter_u64_free(rack_reorder_seen);
2900 	counter_u64_free(rack_tlp_tot);
2901 	counter_u64_free(rack_tlp_newdata);
2902 	counter_u64_free(rack_tlp_retran);
2903 	counter_u64_free(rack_tlp_retran_bytes);
2904 	counter_u64_free(rack_tlp_retran_fail);
2905 	counter_u64_free(rack_to_tot);
2906 	counter_u64_free(rack_to_arm_rack);
2907 	counter_u64_free(rack_to_arm_tlp);
2908 	counter_u64_free(rack_calc_zero);
2909 	counter_u64_free(rack_calc_nonzero);
2910 	counter_u64_free(rack_paced_segments);
2911 	counter_u64_free(rack_unpaced_segments);
2912 	counter_u64_free(rack_saw_enobuf);
2913 	counter_u64_free(rack_saw_enobuf_hw);
2914 	counter_u64_free(rack_saw_enetunreach);
2915 	counter_u64_free(rack_hot_alloc);
2916 	counter_u64_free(rack_to_alloc);
2917 	counter_u64_free(rack_to_alloc_hard);
2918 	counter_u64_free(rack_to_alloc_emerg);
2919 	counter_u64_free(rack_to_alloc_limited);
2920 	counter_u64_free(rack_alloc_limited_conns);
2921 	counter_u64_free(rack_split_limited);
2922 	for (i = 0; i < MAX_NUM_OF_CNTS; i++) {
2923 		counter_u64_free(rack_proc_comp_ack[i]);
2924 	}
2925 	counter_u64_free(rack_multi_single_eq);
2926 	counter_u64_free(rack_proc_non_comp_ack);
2927 	counter_u64_free(rack_sack_proc_all);
2928 	counter_u64_free(rack_sack_proc_restart);
2929 	counter_u64_free(rack_sack_proc_short);
2930 	counter_u64_free(rack_enter_tlp_calc);
2931 	counter_u64_free(rack_used_tlpmethod);
2932 	counter_u64_free(rack_used_tlpmethod2);
2933 	counter_u64_free(rack_sack_skipped_acked);
2934 	counter_u64_free(rack_sack_splits);
2935 	counter_u64_free(rack_progress_drops);
2936 	counter_u64_free(rack_input_idle_reduces);
2937 	counter_u64_free(rack_collapsed_win);
2938 	counter_u64_free(rack_tlp_does_nada);
2939 	counter_u64_free(rack_try_scwnd);
2940 	counter_u64_free(rack_per_timer_hole);
2941 	counter_u64_free(rack_large_ackcmp);
2942 	counter_u64_free(rack_small_ackcmp);
2943 #ifdef INVARIANTS
2944 	counter_u64_free(rack_adjust_map_bw);
2945 #endif
2946 	COUNTER_ARRAY_FREE(rack_out_size, TCP_MSS_ACCT_SIZE);
2947 	COUNTER_ARRAY_FREE(rack_opts_arry, RACK_OPTS_SIZE);
2948 }
2949 
2950 static struct rack_sendmap *
2951 rack_alloc(struct tcp_rack *rack)
2952 {
2953 	struct rack_sendmap *rsm;
2954 
2955 	/*
2956 	 * First get the top of the list it in
2957 	 * theory is the "hottest" rsm we have,
2958 	 * possibly just freed by ack processing.
2959 	 */
2960 	if (rack->rc_free_cnt > rack_free_cache) {
2961 		rsm = TAILQ_FIRST(&rack->r_ctl.rc_free);
2962 		TAILQ_REMOVE(&rack->r_ctl.rc_free, rsm, r_tnext);
2963 		counter_u64_add(rack_hot_alloc, 1);
2964 		rack->rc_free_cnt--;
2965 		return (rsm);
2966 	}
2967 	/*
2968 	 * Once we get under our free cache we probably
2969 	 * no longer have a "hot" one available. Lets
2970 	 * get one from UMA.
2971 	 */
2972 	rsm = uma_zalloc(rack_zone, M_NOWAIT);
2973 	if (rsm) {
2974 		rack->r_ctl.rc_num_maps_alloced++;
2975 		counter_u64_add(rack_to_alloc, 1);
2976 		return (rsm);
2977 	}
2978 	/*
2979 	 * Dig in to our aux rsm's (the last two) since
2980 	 * UMA failed to get us one.
2981 	 */
2982 	if (rack->rc_free_cnt) {
2983 		counter_u64_add(rack_to_alloc_emerg, 1);
2984 		rsm = TAILQ_FIRST(&rack->r_ctl.rc_free);
2985 		TAILQ_REMOVE(&rack->r_ctl.rc_free, rsm, r_tnext);
2986 		rack->rc_free_cnt--;
2987 		return (rsm);
2988 	}
2989 	return (NULL);
2990 }
2991 
2992 static struct rack_sendmap *
2993 rack_alloc_full_limit(struct tcp_rack *rack)
2994 {
2995 	if ((V_tcp_map_entries_limit > 0) &&
2996 	    (rack->do_detection == 0) &&
2997 	    (rack->r_ctl.rc_num_maps_alloced >= V_tcp_map_entries_limit)) {
2998 		counter_u64_add(rack_to_alloc_limited, 1);
2999 		if (!rack->alloc_limit_reported) {
3000 			rack->alloc_limit_reported = 1;
3001 			counter_u64_add(rack_alloc_limited_conns, 1);
3002 		}
3003 		return (NULL);
3004 	}
3005 	return (rack_alloc(rack));
3006 }
3007 
3008 /* wrapper to allocate a sendmap entry, subject to a specific limit */
3009 static struct rack_sendmap *
3010 rack_alloc_limit(struct tcp_rack *rack, uint8_t limit_type)
3011 {
3012 	struct rack_sendmap *rsm;
3013 
3014 	if (limit_type) {
3015 		/* currently there is only one limit type */
3016 		if (V_tcp_map_split_limit > 0 &&
3017 		    (rack->do_detection == 0) &&
3018 		    rack->r_ctl.rc_num_split_allocs >= V_tcp_map_split_limit) {
3019 			counter_u64_add(rack_split_limited, 1);
3020 			if (!rack->alloc_limit_reported) {
3021 				rack->alloc_limit_reported = 1;
3022 				counter_u64_add(rack_alloc_limited_conns, 1);
3023 			}
3024 			return (NULL);
3025 		}
3026 	}
3027 
3028 	/* allocate and mark in the limit type, if set */
3029 	rsm = rack_alloc(rack);
3030 	if (rsm != NULL && limit_type) {
3031 		rsm->r_limit_type = limit_type;
3032 		rack->r_ctl.rc_num_split_allocs++;
3033 	}
3034 	return (rsm);
3035 }
3036 
3037 static void
3038 rack_free(struct tcp_rack *rack, struct rack_sendmap *rsm)
3039 {
3040 	if (rsm->r_flags & RACK_APP_LIMITED) {
3041 		if (rack->r_ctl.rc_app_limited_cnt > 0) {
3042 			rack->r_ctl.rc_app_limited_cnt--;
3043 		}
3044 	}
3045 	if (rsm->r_limit_type) {
3046 		/* currently there is only one limit type */
3047 		rack->r_ctl.rc_num_split_allocs--;
3048 	}
3049 	if (rsm == rack->r_ctl.rc_first_appl) {
3050 		if (rack->r_ctl.rc_app_limited_cnt == 0)
3051 			rack->r_ctl.rc_first_appl = NULL;
3052 		else {
3053 			/* Follow the next one out */
3054 			struct rack_sendmap fe;
3055 
3056 			fe.r_start = rsm->r_nseq_appl;
3057 			rack->r_ctl.rc_first_appl = RB_FIND(rack_rb_tree_head, &rack->r_ctl.rc_mtree, &fe);
3058 		}
3059 	}
3060 	if (rsm == rack->r_ctl.rc_resend)
3061 		rack->r_ctl.rc_resend = NULL;
3062 	if (rsm == rack->r_ctl.rc_rsm_at_retran)
3063 		rack->r_ctl.rc_rsm_at_retran = NULL;
3064 	if (rsm == rack->r_ctl.rc_end_appl)
3065 		rack->r_ctl.rc_end_appl = NULL;
3066 	if (rack->r_ctl.rc_tlpsend == rsm)
3067 		rack->r_ctl.rc_tlpsend = NULL;
3068 	if (rack->r_ctl.rc_sacklast == rsm)
3069 		rack->r_ctl.rc_sacklast = NULL;
3070 	memset(rsm, 0, sizeof(struct rack_sendmap));
3071 	TAILQ_INSERT_HEAD(&rack->r_ctl.rc_free, rsm, r_tnext);
3072 	rack->rc_free_cnt++;
3073 }
3074 
3075 static void
3076 rack_free_trim(struct tcp_rack *rack)
3077 {
3078 	struct rack_sendmap *rsm;
3079 
3080 	/*
3081 	 * Free up all the tail entries until
3082 	 * we get our list down to the limit.
3083 	 */
3084 	while (rack->rc_free_cnt > rack_free_cache) {
3085 		rsm = TAILQ_LAST(&rack->r_ctl.rc_free, rack_head);
3086 		TAILQ_REMOVE(&rack->r_ctl.rc_free, rsm, r_tnext);
3087 		rack->rc_free_cnt--;
3088 		uma_zfree(rack_zone, rsm);
3089 	}
3090 }
3091 
3092 
3093 static uint32_t
3094 rack_get_measure_window(struct tcpcb *tp, struct tcp_rack *rack)
3095 {
3096 	uint64_t srtt, bw, len, tim;
3097 	uint32_t segsiz, def_len, minl;
3098 
3099 	segsiz = min(ctf_fixed_maxseg(tp), rack->r_ctl.rc_pace_min_segs);
3100 	def_len = rack_def_data_window * segsiz;
3101 	if (rack->rc_gp_filled == 0) {
3102 		/*
3103 		 * We have no measurement (IW is in flight?) so
3104 		 * we can only guess using our data_window sysctl
3105 		 * value (usually 20MSS).
3106 		 */
3107 		return (def_len);
3108 	}
3109 	/*
3110 	 * Now we have a number of factors to consider.
3111 	 *
3112 	 * 1) We have a desired BDP which is usually
3113 	 *    at least 2.
3114 	 * 2) We have a minimum number of rtt's usually 1 SRTT
3115 	 *    but we allow it too to be more.
3116 	 * 3) We want to make sure a measurement last N useconds (if
3117 	 *    we have set rack_min_measure_usec.
3118 	 *
3119 	 * We handle the first concern here by trying to create a data
3120 	 * window of max(rack_def_data_window, DesiredBDP). The
3121 	 * second concern we handle in not letting the measurement
3122 	 * window end normally until at least the required SRTT's
3123 	 * have gone by which is done further below in
3124 	 * rack_enough_for_measurement(). Finally the third concern
3125 	 * we also handle here by calculating how long that time
3126 	 * would take at the current BW and then return the
3127 	 * max of our first calculation and that length. Note
3128 	 * that if rack_min_measure_usec is 0, we don't deal
3129 	 * with concern 3. Also for both Concern 1 and 3 an
3130 	 * application limited period could end the measurement
3131 	 * earlier.
3132 	 *
3133 	 * So lets calculate the BDP with the "known" b/w using
3134 	 * the SRTT has our rtt and then multiply it by the
3135 	 * goal.
3136 	 */
3137 	bw = rack_get_bw(rack);
3138 	srtt = (uint64_t)tp->t_srtt;
3139 	len = bw * srtt;
3140 	len /= (uint64_t)HPTS_USEC_IN_SEC;
3141 	len *= max(1, rack_goal_bdp);
3142 	/* Now we need to round up to the nearest MSS */
3143 	len = roundup(len, segsiz);
3144 	if (rack_min_measure_usec) {
3145 		/* Now calculate our min length for this b/w */
3146 		tim = rack_min_measure_usec;
3147 		minl = (tim * bw) / (uint64_t)HPTS_USEC_IN_SEC;
3148 		if (minl == 0)
3149 			minl = 1;
3150 		minl = roundup(minl, segsiz);
3151 		if (len < minl)
3152 			len = minl;
3153 	}
3154 	/*
3155 	 * Now if we have a very small window we want
3156 	 * to attempt to get the window that is
3157 	 * as small as possible. This happens on
3158 	 * low b/w connections and we don't want to
3159 	 * span huge numbers of rtt's between measurements.
3160 	 *
3161 	 * We basically include 2 over our "MIN window" so
3162 	 * that the measurement can be shortened (possibly) by
3163 	 * an ack'ed packet.
3164 	 */
3165 	if (len < def_len)
3166 		return (max((uint32_t)len, ((MIN_GP_WIN+2) * segsiz)));
3167 	else
3168 		return (max((uint32_t)len, def_len));
3169 
3170 }
3171 
3172 static int
3173 rack_enough_for_measurement(struct tcpcb *tp, struct tcp_rack *rack, tcp_seq th_ack, uint8_t *quality)
3174 {
3175 	uint32_t tim, srtts, segsiz;
3176 
3177 	/*
3178 	 * Has enough time passed for the GP measurement to be valid?
3179 	 */
3180 	if ((tp->snd_max == tp->snd_una) ||
3181 	    (th_ack == tp->snd_max)){
3182 		/* All is acked */
3183 		*quality = RACK_QUALITY_ALLACKED;
3184 		return (1);
3185 	}
3186 	if (SEQ_LT(th_ack, tp->gput_seq)) {
3187 		/* Not enough bytes yet */
3188 		return (0);
3189 	}
3190 	segsiz = min(ctf_fixed_maxseg(tp), rack->r_ctl.rc_pace_min_segs);
3191 	if (SEQ_LT(th_ack, tp->gput_ack) &&
3192 	    ((th_ack - tp->gput_seq) < max(rc_init_window(rack), (MIN_GP_WIN * segsiz)))) {
3193 		/* Not enough bytes yet */
3194 		return (0);
3195 	}
3196 	if (rack->r_ctl.rc_first_appl &&
3197 	    (SEQ_GEQ(th_ack, rack->r_ctl.rc_first_appl->r_end))) {
3198 		/*
3199 		 * We are up to the app limited send point
3200 		 * we have to measure irrespective of the time..
3201 		 */
3202 		*quality = RACK_QUALITY_APPLIMITED;
3203 		return (1);
3204 	}
3205 	/* Now what about time? */
3206 	srtts = (rack->r_ctl.rc_gp_srtt * rack_min_srtts);
3207 	tim = tcp_tv_to_usectick(&rack->r_ctl.act_rcv_time) - tp->gput_ts;
3208 	if (tim >= srtts) {
3209 		*quality = RACK_QUALITY_HIGH;
3210 		return (1);
3211 	}
3212 	/* Nope not even a full SRTT has passed */
3213 	return (0);
3214 }
3215 
3216 static void
3217 rack_log_timely(struct tcp_rack *rack,
3218 		uint32_t logged, uint64_t cur_bw, uint64_t low_bnd,
3219 		uint64_t up_bnd, int line, uint8_t method)
3220 {
3221 	if (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
3222 		union tcp_log_stackspecific log;
3223 		struct timeval tv;
3224 
3225 		memset(&log, 0, sizeof(log));
3226 		log.u_bbr.flex1 = logged;
3227 		log.u_bbr.flex2 = rack->rc_gp_timely_inc_cnt;
3228 		log.u_bbr.flex2 <<= 4;
3229 		log.u_bbr.flex2 |= rack->rc_gp_timely_dec_cnt;
3230 		log.u_bbr.flex2 <<= 4;
3231 		log.u_bbr.flex2 |= rack->rc_gp_incr;
3232 		log.u_bbr.flex2 <<= 4;
3233 		log.u_bbr.flex2 |= rack->rc_gp_bwred;
3234 		log.u_bbr.flex3 = rack->rc_gp_incr;
3235 		log.u_bbr.flex4 = rack->r_ctl.rack_per_of_gp_ss;
3236 		log.u_bbr.flex5 = rack->r_ctl.rack_per_of_gp_ca;
3237 		log.u_bbr.flex6 = rack->r_ctl.rack_per_of_gp_rec;
3238 		log.u_bbr.flex7 = rack->rc_gp_bwred;
3239 		log.u_bbr.flex8 = method;
3240 		log.u_bbr.cur_del_rate = cur_bw;
3241 		log.u_bbr.delRate = low_bnd;
3242 		log.u_bbr.bw_inuse = up_bnd;
3243 		log.u_bbr.rttProp = rack_get_bw(rack);
3244 		log.u_bbr.pkt_epoch = line;
3245 		log.u_bbr.pkts_out = rack->r_ctl.rc_rtt_diff;
3246 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
3247 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
3248 		log.u_bbr.epoch = rack->r_ctl.rc_gp_srtt;
3249 		log.u_bbr.lt_epoch = rack->r_ctl.rc_prev_gp_srtt;
3250 		log.u_bbr.cwnd_gain = rack->rc_dragged_bottom;
3251 		log.u_bbr.cwnd_gain <<= 1;
3252 		log.u_bbr.cwnd_gain |= rack->rc_gp_saw_rec;
3253 		log.u_bbr.cwnd_gain <<= 1;
3254 		log.u_bbr.cwnd_gain |= rack->rc_gp_saw_ss;
3255 		log.u_bbr.cwnd_gain <<= 1;
3256 		log.u_bbr.cwnd_gain |= rack->rc_gp_saw_ca;
3257 		log.u_bbr.lost = rack->r_ctl.rc_loss_count;
3258 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
3259 		    &rack->rc_inp->inp_socket->so_rcv,
3260 		    &rack->rc_inp->inp_socket->so_snd,
3261 		    TCP_TIMELY_WORK, 0,
3262 		    0, &log, false, &tv);
3263 	}
3264 }
3265 
3266 static int
3267 rack_bw_can_be_raised(struct tcp_rack *rack, uint64_t cur_bw, uint64_t last_bw_est, uint16_t mult)
3268 {
3269 	/*
3270 	 * Before we increase we need to know if
3271 	 * the estimate just made was less than
3272 	 * our pacing goal (i.e. (cur_bw * mult) > last_bw_est)
3273 	 *
3274 	 * If we already are pacing at a fast enough
3275 	 * rate to push us faster there is no sense of
3276 	 * increasing.
3277 	 *
3278 	 * We first caculate our actual pacing rate (ss or ca multipler
3279 	 * times our cur_bw).
3280 	 *
3281 	 * Then we take the last measured rate and multipy by our
3282 	 * maximum pacing overage to give us a max allowable rate.
3283 	 *
3284 	 * If our act_rate is smaller than our max_allowable rate
3285 	 * then we should increase. Else we should hold steady.
3286 	 *
3287 	 */
3288 	uint64_t act_rate, max_allow_rate;
3289 
3290 	if (rack_timely_no_stopping)
3291 		return (1);
3292 
3293 	if ((cur_bw == 0) || (last_bw_est == 0)) {
3294 		/*
3295 		 * Initial startup case or
3296 		 * everything is acked case.
3297 		 */
3298 		rack_log_timely(rack,  mult, cur_bw, 0, 0,
3299 				__LINE__, 9);
3300 		return (1);
3301 	}
3302 	if (mult <= 100) {
3303 		/*
3304 		 * We can always pace at or slightly above our rate.
3305 		 */
3306 		rack_log_timely(rack,  mult, cur_bw, 0, 0,
3307 				__LINE__, 9);
3308 		return (1);
3309 	}
3310 	act_rate = cur_bw * (uint64_t)mult;
3311 	act_rate /= 100;
3312 	max_allow_rate = last_bw_est * ((uint64_t)rack_max_per_above + (uint64_t)100);
3313 	max_allow_rate /= 100;
3314 	if (act_rate < max_allow_rate) {
3315 		/*
3316 		 * Here the rate we are actually pacing at
3317 		 * is smaller than 10% above our last measurement.
3318 		 * This means we are pacing below what we would
3319 		 * like to try to achieve (plus some wiggle room).
3320 		 */
3321 		rack_log_timely(rack,  mult, cur_bw, act_rate, max_allow_rate,
3322 				__LINE__, 9);
3323 		return (1);
3324 	} else {
3325 		/*
3326 		 * Here we are already pacing at least rack_max_per_above(10%)
3327 		 * what we are getting back. This indicates most likely
3328 		 * that we are being limited (cwnd/rwnd/app) and can't
3329 		 * get any more b/w. There is no sense of trying to
3330 		 * raise up the pacing rate its not speeding us up
3331 		 * and we already are pacing faster than we are getting.
3332 		 */
3333 		rack_log_timely(rack,  mult, cur_bw, act_rate, max_allow_rate,
3334 				__LINE__, 8);
3335 		return (0);
3336 	}
3337 }
3338 
3339 static void
3340 rack_validate_multipliers_at_or_above100(struct tcp_rack *rack)
3341 {
3342 	/*
3343 	 * When we drag bottom, we want to assure
3344 	 * that no multiplier is below 1.0, if so
3345 	 * we want to restore it to at least that.
3346 	 */
3347 	if (rack->r_ctl.rack_per_of_gp_rec  < 100) {
3348 		/* This is unlikely we usually do not touch recovery */
3349 		rack->r_ctl.rack_per_of_gp_rec = 100;
3350 	}
3351 	if (rack->r_ctl.rack_per_of_gp_ca < 100) {
3352 		rack->r_ctl.rack_per_of_gp_ca = 100;
3353 	}
3354 	if (rack->r_ctl.rack_per_of_gp_ss < 100) {
3355 		rack->r_ctl.rack_per_of_gp_ss = 100;
3356 	}
3357 }
3358 
3359 static void
3360 rack_validate_multipliers_at_or_below_100(struct tcp_rack *rack)
3361 {
3362 	if (rack->r_ctl.rack_per_of_gp_ca > 100) {
3363 		rack->r_ctl.rack_per_of_gp_ca = 100;
3364 	}
3365 	if (rack->r_ctl.rack_per_of_gp_ss > 100) {
3366 		rack->r_ctl.rack_per_of_gp_ss = 100;
3367 	}
3368 }
3369 
3370 static void
3371 rack_increase_bw_mul(struct tcp_rack *rack, int timely_says, uint64_t cur_bw, uint64_t last_bw_est, int override)
3372 {
3373 	int32_t  calc, logged, plus;
3374 
3375 	logged = 0;
3376 
3377 	if (override) {
3378 		/*
3379 		 * override is passed when we are
3380 		 * loosing b/w and making one last
3381 		 * gasp at trying to not loose out
3382 		 * to a new-reno flow.
3383 		 */
3384 		goto extra_boost;
3385 	}
3386 	/* In classic timely we boost by 5x if we have 5 increases in a row, lets not */
3387 	if (rack->rc_gp_incr &&
3388 	    ((rack->rc_gp_timely_inc_cnt + 1) >= RACK_TIMELY_CNT_BOOST)) {
3389 		/*
3390 		 * Reset and get 5 strokes more before the boost. Note
3391 		 * that the count is 0 based so we have to add one.
3392 		 */
3393 extra_boost:
3394 		plus = (uint32_t)rack_gp_increase_per * RACK_TIMELY_CNT_BOOST;
3395 		rack->rc_gp_timely_inc_cnt = 0;
3396 	} else
3397 		plus = (uint32_t)rack_gp_increase_per;
3398 	/* Must be at least 1% increase for true timely increases */
3399 	if ((plus < 1) &&
3400 	    ((rack->r_ctl.rc_rtt_diff <= 0) || (timely_says <= 0)))
3401 		plus = 1;
3402 	if (rack->rc_gp_saw_rec &&
3403 	    (rack->rc_gp_no_rec_chg == 0) &&
3404 	    rack_bw_can_be_raised(rack, cur_bw, last_bw_est,
3405 				  rack->r_ctl.rack_per_of_gp_rec)) {
3406 		/* We have been in recovery ding it too */
3407 		calc = rack->r_ctl.rack_per_of_gp_rec + plus;
3408 		if (calc > 0xffff)
3409 			calc = 0xffff;
3410 		logged |= 1;
3411 		rack->r_ctl.rack_per_of_gp_rec = (uint16_t)calc;
3412 		if (rack_per_upper_bound_ss &&
3413 		    (rack->rc_dragged_bottom == 0) &&
3414 		    (rack->r_ctl.rack_per_of_gp_rec > rack_per_upper_bound_ss))
3415 			rack->r_ctl.rack_per_of_gp_rec = rack_per_upper_bound_ss;
3416 	}
3417 	if (rack->rc_gp_saw_ca &&
3418 	    (rack->rc_gp_saw_ss == 0) &&
3419 	    rack_bw_can_be_raised(rack, cur_bw, last_bw_est,
3420 				  rack->r_ctl.rack_per_of_gp_ca)) {
3421 		/* In CA */
3422 		calc = rack->r_ctl.rack_per_of_gp_ca + plus;
3423 		if (calc > 0xffff)
3424 			calc = 0xffff;
3425 		logged |= 2;
3426 		rack->r_ctl.rack_per_of_gp_ca = (uint16_t)calc;
3427 		if (rack_per_upper_bound_ca &&
3428 		    (rack->rc_dragged_bottom == 0) &&
3429 		    (rack->r_ctl.rack_per_of_gp_ca > rack_per_upper_bound_ca))
3430 			rack->r_ctl.rack_per_of_gp_ca = rack_per_upper_bound_ca;
3431 	}
3432 	if (rack->rc_gp_saw_ss &&
3433 	    rack_bw_can_be_raised(rack, cur_bw, last_bw_est,
3434 				  rack->r_ctl.rack_per_of_gp_ss)) {
3435 		/* In SS */
3436 		calc = rack->r_ctl.rack_per_of_gp_ss + plus;
3437 		if (calc > 0xffff)
3438 			calc = 0xffff;
3439 		rack->r_ctl.rack_per_of_gp_ss = (uint16_t)calc;
3440 		if (rack_per_upper_bound_ss &&
3441 		    (rack->rc_dragged_bottom == 0) &&
3442 		    (rack->r_ctl.rack_per_of_gp_ss > rack_per_upper_bound_ss))
3443 			rack->r_ctl.rack_per_of_gp_ss = rack_per_upper_bound_ss;
3444 		logged |= 4;
3445 	}
3446 	if (logged &&
3447 	    (rack->rc_gp_incr == 0)){
3448 		/* Go into increment mode */
3449 		rack->rc_gp_incr = 1;
3450 		rack->rc_gp_timely_inc_cnt = 0;
3451 	}
3452 	if (rack->rc_gp_incr &&
3453 	    logged &&
3454 	    (rack->rc_gp_timely_inc_cnt < RACK_TIMELY_CNT_BOOST)) {
3455 		rack->rc_gp_timely_inc_cnt++;
3456 	}
3457 	rack_log_timely(rack,  logged, plus, 0, 0,
3458 			__LINE__, 1);
3459 }
3460 
3461 static uint32_t
3462 rack_get_decrease(struct tcp_rack *rack, uint32_t curper, int32_t rtt_diff)
3463 {
3464 	/*
3465 	 * norm_grad = rtt_diff / minrtt;
3466 	 * new_per = curper * (1 - B * norm_grad)
3467 	 *
3468 	 * B = rack_gp_decrease_per (default 10%)
3469 	 * rtt_dif = input var current rtt-diff
3470 	 * curper = input var current percentage
3471 	 * minrtt = from rack filter
3472 	 *
3473 	 */
3474 	uint64_t perf;
3475 
3476 	perf = (((uint64_t)curper * ((uint64_t)1000000 -
3477 		    ((uint64_t)rack_gp_decrease_per * (uint64_t)10000 *
3478 		     (((uint64_t)rtt_diff * (uint64_t)1000000)/
3479 		      (uint64_t)get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt)))/
3480 		     (uint64_t)1000000)) /
3481 		(uint64_t)1000000);
3482 	if (perf > curper) {
3483 		/* TSNH */
3484 		perf = curper - 1;
3485 	}
3486 	return ((uint32_t)perf);
3487 }
3488 
3489 static uint32_t
3490 rack_decrease_highrtt(struct tcp_rack *rack, uint32_t curper, uint32_t rtt)
3491 {
3492 	/*
3493 	 *                                   highrttthresh
3494 	 * result = curper * (1 - (B * ( 1 -  ------          ))
3495 	 *                                     gp_srtt
3496 	 *
3497 	 * B = rack_gp_decrease_per (default 10%)
3498 	 * highrttthresh = filter_min * rack_gp_rtt_maxmul
3499 	 */
3500 	uint64_t perf;
3501 	uint32_t highrttthresh;
3502 
3503 	highrttthresh = get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt) * rack_gp_rtt_maxmul;
3504 
3505 	perf = (((uint64_t)curper * ((uint64_t)1000000 -
3506 				     ((uint64_t)rack_gp_decrease_per * ((uint64_t)1000000 -
3507 					((uint64_t)highrttthresh * (uint64_t)1000000) /
3508 						    (uint64_t)rtt)) / 100)) /(uint64_t)1000000);
3509 	return (perf);
3510 }
3511 
3512 static void
3513 rack_decrease_bw_mul(struct tcp_rack *rack, int timely_says, uint32_t rtt, int32_t rtt_diff)
3514 {
3515 	uint64_t logvar, logvar2, logvar3;
3516 	uint32_t logged, new_per, ss_red, ca_red, rec_red, alt, val;
3517 
3518 	if (rack->rc_gp_incr) {
3519 		/* Turn off increment counting */
3520 		rack->rc_gp_incr = 0;
3521 		rack->rc_gp_timely_inc_cnt = 0;
3522 	}
3523 	ss_red = ca_red = rec_red = 0;
3524 	logged = 0;
3525 	/* Calculate the reduction value */
3526 	if (rtt_diff < 0) {
3527 		rtt_diff *= -1;
3528 	}
3529 	/* Must be at least 1% reduction */
3530 	if (rack->rc_gp_saw_rec && (rack->rc_gp_no_rec_chg == 0)) {
3531 		/* We have been in recovery ding it too */
3532 		if (timely_says == 2) {
3533 			new_per = rack_decrease_highrtt(rack, rack->r_ctl.rack_per_of_gp_rec, rtt);
3534 			alt = rack_get_decrease(rack, rack->r_ctl.rack_per_of_gp_rec, rtt_diff);
3535 			if (alt < new_per)
3536 				val = alt;
3537 			else
3538 				val = new_per;
3539 		} else
3540 			 val = new_per = alt = rack_get_decrease(rack, rack->r_ctl.rack_per_of_gp_rec, rtt_diff);
3541 		if (rack->r_ctl.rack_per_of_gp_rec > val) {
3542 			rec_red = (rack->r_ctl.rack_per_of_gp_rec - val);
3543 			rack->r_ctl.rack_per_of_gp_rec = (uint16_t)val;
3544 		} else {
3545 			rack->r_ctl.rack_per_of_gp_rec = rack_per_lower_bound;
3546 			rec_red = 0;
3547 		}
3548 		if (rack_per_lower_bound > rack->r_ctl.rack_per_of_gp_rec)
3549 			rack->r_ctl.rack_per_of_gp_rec = rack_per_lower_bound;
3550 		logged |= 1;
3551 	}
3552 	if (rack->rc_gp_saw_ss) {
3553 		/* Sent in SS */
3554 		if (timely_says == 2) {
3555 			new_per = rack_decrease_highrtt(rack, rack->r_ctl.rack_per_of_gp_ss, rtt);
3556 			alt = rack_get_decrease(rack, rack->r_ctl.rack_per_of_gp_rec, rtt_diff);
3557 			if (alt < new_per)
3558 				val = alt;
3559 			else
3560 				val = new_per;
3561 		} else
3562 			val = new_per = alt = rack_get_decrease(rack, rack->r_ctl.rack_per_of_gp_ss, rtt_diff);
3563 		if (rack->r_ctl.rack_per_of_gp_ss > new_per) {
3564 			ss_red = rack->r_ctl.rack_per_of_gp_ss - val;
3565 			rack->r_ctl.rack_per_of_gp_ss = (uint16_t)val;
3566 		} else {
3567 			ss_red = new_per;
3568 			rack->r_ctl.rack_per_of_gp_ss = rack_per_lower_bound;
3569 			logvar = new_per;
3570 			logvar <<= 32;
3571 			logvar |= alt;
3572 			logvar2 = (uint32_t)rtt;
3573 			logvar2 <<= 32;
3574 			logvar2 |= (uint32_t)rtt_diff;
3575 			logvar3 = rack_gp_rtt_maxmul;
3576 			logvar3 <<= 32;
3577 			logvar3 |= get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt);
3578 			rack_log_timely(rack, timely_says,
3579 					logvar2, logvar3,
3580 					logvar, __LINE__, 10);
3581 		}
3582 		if (rack_per_lower_bound > rack->r_ctl.rack_per_of_gp_ss)
3583 			rack->r_ctl.rack_per_of_gp_ss = rack_per_lower_bound;
3584 		logged |= 4;
3585 	} else if (rack->rc_gp_saw_ca) {
3586 		/* Sent in CA */
3587 		if (timely_says == 2) {
3588 			new_per = rack_decrease_highrtt(rack, rack->r_ctl.rack_per_of_gp_ca, rtt);
3589 			alt = rack_get_decrease(rack, rack->r_ctl.rack_per_of_gp_rec, rtt_diff);
3590 			if (alt < new_per)
3591 				val = alt;
3592 			else
3593 				val = new_per;
3594 		} else
3595 			val = new_per = alt = rack_get_decrease(rack, rack->r_ctl.rack_per_of_gp_ca, rtt_diff);
3596 		if (rack->r_ctl.rack_per_of_gp_ca > val) {
3597 			ca_red = rack->r_ctl.rack_per_of_gp_ca - val;
3598 			rack->r_ctl.rack_per_of_gp_ca = (uint16_t)val;
3599 		} else {
3600 			rack->r_ctl.rack_per_of_gp_ca = rack_per_lower_bound;
3601 			ca_red = 0;
3602 			logvar = new_per;
3603 			logvar <<= 32;
3604 			logvar |= alt;
3605 			logvar2 = (uint32_t)rtt;
3606 			logvar2 <<= 32;
3607 			logvar2 |= (uint32_t)rtt_diff;
3608 			logvar3 = rack_gp_rtt_maxmul;
3609 			logvar3 <<= 32;
3610 			logvar3 |= get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt);
3611 			rack_log_timely(rack, timely_says,
3612 					logvar2, logvar3,
3613 					logvar, __LINE__, 10);
3614 		}
3615 		if (rack_per_lower_bound > rack->r_ctl.rack_per_of_gp_ca)
3616 			rack->r_ctl.rack_per_of_gp_ca = rack_per_lower_bound;
3617 		logged |= 2;
3618 	}
3619 	if (rack->rc_gp_timely_dec_cnt < 0x7) {
3620 		rack->rc_gp_timely_dec_cnt++;
3621 		if (rack_timely_dec_clear &&
3622 		    (rack->rc_gp_timely_dec_cnt == rack_timely_dec_clear))
3623 			rack->rc_gp_timely_dec_cnt = 0;
3624 	}
3625 	logvar = ss_red;
3626 	logvar <<= 32;
3627 	logvar |= ca_red;
3628 	rack_log_timely(rack,  logged, rec_red, rack_per_lower_bound, logvar,
3629 			__LINE__, 2);
3630 }
3631 
3632 static void
3633 rack_log_rtt_shrinks(struct tcp_rack *rack, uint32_t us_cts,
3634 		     uint32_t rtt, uint32_t line, uint8_t reas)
3635 {
3636 	if (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
3637 		union tcp_log_stackspecific log;
3638 		struct timeval tv;
3639 
3640 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
3641 		log.u_bbr.flex1 = line;
3642 		log.u_bbr.flex2 = rack->r_ctl.rc_time_probertt_starts;
3643 		log.u_bbr.flex3 = rack->r_ctl.rc_lower_rtt_us_cts;
3644 		log.u_bbr.flex4 = rack->r_ctl.rack_per_of_gp_ss;
3645 		log.u_bbr.flex5 = rtt;
3646 		log.u_bbr.flex6 = rack->rc_highly_buffered;
3647 		log.u_bbr.flex6 <<= 1;
3648 		log.u_bbr.flex6 |= rack->forced_ack;
3649 		log.u_bbr.flex6 <<= 1;
3650 		log.u_bbr.flex6 |= rack->rc_gp_dyn_mul;
3651 		log.u_bbr.flex6 <<= 1;
3652 		log.u_bbr.flex6 |= rack->in_probe_rtt;
3653 		log.u_bbr.flex6 <<= 1;
3654 		log.u_bbr.flex6 |= rack->measure_saw_probe_rtt;
3655 		log.u_bbr.flex7 = rack->r_ctl.rack_per_of_gp_probertt;
3656 		log.u_bbr.pacing_gain = rack->r_ctl.rack_per_of_gp_ca;
3657 		log.u_bbr.cwnd_gain = rack->r_ctl.rack_per_of_gp_rec;
3658 		log.u_bbr.flex8 = reas;
3659 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
3660 		log.u_bbr.delRate = rack_get_bw(rack);
3661 		log.u_bbr.cur_del_rate = rack->r_ctl.rc_highest_us_rtt;
3662 		log.u_bbr.cur_del_rate <<= 32;
3663 		log.u_bbr.cur_del_rate |= rack->r_ctl.rc_lowest_us_rtt;
3664 		log.u_bbr.applimited = rack->r_ctl.rc_time_probertt_entered;
3665 		log.u_bbr.pkts_out = rack->r_ctl.rc_rtt_diff;
3666 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
3667 		log.u_bbr.epoch = rack->r_ctl.rc_gp_srtt;
3668 		log.u_bbr.lt_epoch = rack->r_ctl.rc_prev_gp_srtt;
3669 		log.u_bbr.pkt_epoch = rack->r_ctl.rc_lower_rtt_us_cts;
3670 		log.u_bbr.delivered = rack->r_ctl.rc_target_probertt_flight;
3671 		log.u_bbr.lost = get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt);
3672 		log.u_bbr.rttProp = us_cts;
3673 		log.u_bbr.rttProp <<= 32;
3674 		log.u_bbr.rttProp |= rack->r_ctl.rc_entry_gp_rtt;
3675 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
3676 		    &rack->rc_inp->inp_socket->so_rcv,
3677 		    &rack->rc_inp->inp_socket->so_snd,
3678 		    BBR_LOG_RTT_SHRINKS, 0,
3679 		    0, &log, false, &rack->r_ctl.act_rcv_time);
3680 	}
3681 }
3682 
3683 static void
3684 rack_set_prtt_target(struct tcp_rack *rack, uint32_t segsiz, uint32_t rtt)
3685 {
3686 	uint64_t bwdp;
3687 
3688 	bwdp = rack_get_bw(rack);
3689 	bwdp *= (uint64_t)rtt;
3690 	bwdp /= (uint64_t)HPTS_USEC_IN_SEC;
3691 	rack->r_ctl.rc_target_probertt_flight = roundup((uint32_t)bwdp, segsiz);
3692 	if (rack->r_ctl.rc_target_probertt_flight < (segsiz * rack_timely_min_segs)) {
3693 		/*
3694 		 * A window protocol must be able to have 4 packets
3695 		 * outstanding as the floor in order to function
3696 		 * (especially considering delayed ack :D).
3697 		 */
3698 		rack->r_ctl.rc_target_probertt_flight = (segsiz * rack_timely_min_segs);
3699 	}
3700 }
3701 
3702 static void
3703 rack_enter_probertt(struct tcp_rack *rack, uint32_t us_cts)
3704 {
3705 	/**
3706 	 * ProbeRTT is a bit different in rack_pacing than in
3707 	 * BBR. It is like BBR in that it uses the lowering of
3708 	 * the RTT as a signal that we saw something new and
3709 	 * counts from there for how long between. But it is
3710 	 * different in that its quite simple. It does not
3711 	 * play with the cwnd and wait until we get down
3712 	 * to N segments outstanding and hold that for
3713 	 * 200ms. Instead it just sets the pacing reduction
3714 	 * rate to a set percentage (70 by default) and hold
3715 	 * that for a number of recent GP Srtt's.
3716 	 */
3717 	uint32_t segsiz;
3718 
3719 	if (rack->rc_gp_dyn_mul == 0)
3720 		return;
3721 
3722 	if (rack->rc_tp->snd_max == rack->rc_tp->snd_una) {
3723 		/* We are idle */
3724 		return;
3725 	}
3726 	if ((rack->rc_tp->t_flags & TF_GPUTINPROG) &&
3727 	    SEQ_GT(rack->rc_tp->snd_una, rack->rc_tp->gput_seq)) {
3728 		/*
3729 		 * Stop the goodput now, the idea here is
3730 		 * that future measurements with in_probe_rtt
3731 		 * won't register if they are not greater so
3732 		 * we want to get what info (if any) is available
3733 		 * now.
3734 		 */
3735 		rack_do_goodput_measurement(rack->rc_tp, rack,
3736 					    rack->rc_tp->snd_una, __LINE__,
3737 					    RACK_QUALITY_PROBERTT);
3738 	}
3739 	rack->r_ctl.rack_per_of_gp_probertt = rack_per_of_gp_probertt;
3740 	rack->r_ctl.rc_time_probertt_entered = us_cts;
3741 	segsiz = min(ctf_fixed_maxseg(rack->rc_tp),
3742 		     rack->r_ctl.rc_pace_min_segs);
3743 	rack->in_probe_rtt = 1;
3744 	rack->measure_saw_probe_rtt = 1;
3745 	rack->r_ctl.rc_lower_rtt_us_cts = us_cts;
3746 	rack->r_ctl.rc_time_probertt_starts = 0;
3747 	rack->r_ctl.rc_entry_gp_rtt = rack->r_ctl.rc_gp_srtt;
3748 	if (rack_probertt_use_min_rtt_entry)
3749 		rack_set_prtt_target(rack, segsiz, get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt));
3750 	else
3751 		rack_set_prtt_target(rack, segsiz, rack->r_ctl.rc_gp_srtt);
3752 	rack_log_rtt_shrinks(rack,  us_cts,  get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt),
3753 			     __LINE__, RACK_RTTS_ENTERPROBE);
3754 }
3755 
3756 static void
3757 rack_exit_probertt(struct tcp_rack *rack, uint32_t us_cts)
3758 {
3759 	struct rack_sendmap *rsm;
3760 	uint32_t segsiz;
3761 
3762 	segsiz = min(ctf_fixed_maxseg(rack->rc_tp),
3763 		     rack->r_ctl.rc_pace_min_segs);
3764 	rack->in_probe_rtt = 0;
3765 	if ((rack->rc_tp->t_flags & TF_GPUTINPROG) &&
3766 	    SEQ_GT(rack->rc_tp->snd_una, rack->rc_tp->gput_seq)) {
3767 		/*
3768 		 * Stop the goodput now, the idea here is
3769 		 * that future measurements with in_probe_rtt
3770 		 * won't register if they are not greater so
3771 		 * we want to get what info (if any) is available
3772 		 * now.
3773 		 */
3774 		rack_do_goodput_measurement(rack->rc_tp, rack,
3775 					    rack->rc_tp->snd_una, __LINE__,
3776 					    RACK_QUALITY_PROBERTT);
3777 	} else if (rack->rc_tp->t_flags & TF_GPUTINPROG) {
3778 		/*
3779 		 * We don't have enough data to make a measurement.
3780 		 * So lets just stop and start here after exiting
3781 		 * probe-rtt. We probably are not interested in
3782 		 * the results anyway.
3783 		 */
3784 		rack->rc_tp->t_flags &= ~TF_GPUTINPROG;
3785 	}
3786 	/*
3787 	 * Measurements through the current snd_max are going
3788 	 * to be limited by the slower pacing rate.
3789 	 *
3790 	 * We need to mark these as app-limited so we
3791 	 * don't collapse the b/w.
3792 	 */
3793 	rsm = RB_MAX(rack_rb_tree_head, &rack->r_ctl.rc_mtree);
3794 	if (rsm && ((rsm->r_flags & RACK_APP_LIMITED) == 0)) {
3795 		if (rack->r_ctl.rc_app_limited_cnt == 0)
3796 			rack->r_ctl.rc_end_appl = rack->r_ctl.rc_first_appl = rsm;
3797 		else {
3798 			/*
3799 			 * Go out to the end app limited and mark
3800 			 * this new one as next and move the end_appl up
3801 			 * to this guy.
3802 			 */
3803 			if (rack->r_ctl.rc_end_appl)
3804 				rack->r_ctl.rc_end_appl->r_nseq_appl = rsm->r_start;
3805 			rack->r_ctl.rc_end_appl = rsm;
3806 		}
3807 		rsm->r_flags |= RACK_APP_LIMITED;
3808 		rack->r_ctl.rc_app_limited_cnt++;
3809 	}
3810 	/*
3811 	 * Now, we need to examine our pacing rate multipliers.
3812 	 * If its under 100%, we need to kick it back up to
3813 	 * 100%. We also don't let it be over our "max" above
3814 	 * the actual rate i.e. 100% + rack_clamp_atexit_prtt.
3815 	 * Note setting clamp_atexit_prtt to 0 has the effect
3816 	 * of setting CA/SS to 100% always at exit (which is
3817 	 * the default behavior).
3818 	 */
3819 	if (rack_probertt_clear_is) {
3820 		rack->rc_gp_incr = 0;
3821 		rack->rc_gp_bwred = 0;
3822 		rack->rc_gp_timely_inc_cnt = 0;
3823 		rack->rc_gp_timely_dec_cnt = 0;
3824 	}
3825 	/* Do we do any clamping at exit? */
3826 	if (rack->rc_highly_buffered && rack_atexit_prtt_hbp) {
3827 		rack->r_ctl.rack_per_of_gp_ca = rack_atexit_prtt_hbp;
3828 		rack->r_ctl.rack_per_of_gp_ss = rack_atexit_prtt_hbp;
3829 	}
3830 	if ((rack->rc_highly_buffered == 0) && rack_atexit_prtt) {
3831 		rack->r_ctl.rack_per_of_gp_ca = rack_atexit_prtt;
3832 		rack->r_ctl.rack_per_of_gp_ss = rack_atexit_prtt;
3833 	}
3834 	/*
3835 	 * Lets set rtt_diff to 0, so that we will get a "boost"
3836 	 * after exiting.
3837 	 */
3838 	rack->r_ctl.rc_rtt_diff = 0;
3839 
3840 	/* Clear all flags so we start fresh */
3841 	rack->rc_tp->t_bytes_acked = 0;
3842 	rack->rc_tp->ccv->flags &= ~CCF_ABC_SENTAWND;
3843 	/*
3844 	 * If configured to, set the cwnd and ssthresh to
3845 	 * our targets.
3846 	 */
3847 	if (rack_probe_rtt_sets_cwnd) {
3848 		uint64_t ebdp;
3849 		uint32_t setto;
3850 
3851 		/* Set ssthresh so we get into CA once we hit our target */
3852 		if (rack_probertt_use_min_rtt_exit == 1) {
3853 			/* Set to min rtt */
3854 			rack_set_prtt_target(rack, segsiz,
3855 					     get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt));
3856 		} else if (rack_probertt_use_min_rtt_exit == 2) {
3857 			/* Set to current gp rtt */
3858 			rack_set_prtt_target(rack, segsiz,
3859 					     rack->r_ctl.rc_gp_srtt);
3860 		} else if (rack_probertt_use_min_rtt_exit == 3) {
3861 			/* Set to entry gp rtt */
3862 			rack_set_prtt_target(rack, segsiz,
3863 					     rack->r_ctl.rc_entry_gp_rtt);
3864 		} else {
3865 			uint64_t sum;
3866 			uint32_t setval;
3867 
3868 			sum = rack->r_ctl.rc_entry_gp_rtt;
3869 			sum *= 10;
3870 			sum /= (uint64_t)(max(1, rack->r_ctl.rc_gp_srtt));
3871 			if (sum >= 20) {
3872 				/*
3873 				 * A highly buffered path needs
3874 				 * cwnd space for timely to work.
3875 				 * Lets set things up as if
3876 				 * we are heading back here again.
3877 				 */
3878 				setval = rack->r_ctl.rc_entry_gp_rtt;
3879 			} else if (sum >= 15) {
3880 				/*
3881 				 * Lets take the smaller of the
3882 				 * two since we are just somewhat
3883 				 * buffered.
3884 				 */
3885 				setval = rack->r_ctl.rc_gp_srtt;
3886 				if (setval > rack->r_ctl.rc_entry_gp_rtt)
3887 					setval = rack->r_ctl.rc_entry_gp_rtt;
3888 			} else {
3889 				/*
3890 				 * Here we are not highly buffered
3891 				 * and should pick the min we can to
3892 				 * keep from causing loss.
3893 				 */
3894 				setval = get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt);
3895 			}
3896 			rack_set_prtt_target(rack, segsiz,
3897 					     setval);
3898 		}
3899 		if (rack_probe_rtt_sets_cwnd > 1) {
3900 			/* There is a percentage here to boost */
3901 			ebdp = rack->r_ctl.rc_target_probertt_flight;
3902 			ebdp *= rack_probe_rtt_sets_cwnd;
3903 			ebdp /= 100;
3904 			setto = rack->r_ctl.rc_target_probertt_flight + ebdp;
3905 		} else
3906 			setto = rack->r_ctl.rc_target_probertt_flight;
3907 		rack->rc_tp->snd_cwnd = roundup(setto, segsiz);
3908 		if (rack->rc_tp->snd_cwnd < (segsiz * rack_timely_min_segs)) {
3909 			/* Enforce a min */
3910 			rack->rc_tp->snd_cwnd = segsiz * rack_timely_min_segs;
3911 		}
3912 		/* If we set in the cwnd also set the ssthresh point so we are in CA */
3913 		rack->rc_tp->snd_ssthresh = (rack->rc_tp->snd_cwnd - 1);
3914 	}
3915 	rack_log_rtt_shrinks(rack,  us_cts,
3916 			     get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt),
3917 			     __LINE__, RACK_RTTS_EXITPROBE);
3918 	/* Clear times last so log has all the info */
3919 	rack->r_ctl.rc_probertt_sndmax_atexit = rack->rc_tp->snd_max;
3920 	rack->r_ctl.rc_time_probertt_entered = us_cts;
3921 	rack->r_ctl.rc_time_probertt_starts = rack->r_ctl.rc_lower_rtt_us_cts = us_cts;
3922 	rack->r_ctl.rc_time_of_last_probertt = us_cts;
3923 }
3924 
3925 static void
3926 rack_check_probe_rtt(struct tcp_rack *rack, uint32_t us_cts)
3927 {
3928 	/* Check in on probe-rtt */
3929 	if (rack->rc_gp_filled == 0) {
3930 		/* We do not do p-rtt unless we have gp measurements */
3931 		return;
3932 	}
3933 	if (rack->in_probe_rtt) {
3934 		uint64_t no_overflow;
3935 		uint32_t endtime, must_stay;
3936 
3937 		if (rack->r_ctl.rc_went_idle_time &&
3938 		    ((us_cts - rack->r_ctl.rc_went_idle_time) > rack_min_probertt_hold)) {
3939 			/*
3940 			 * We went idle during prtt, just exit now.
3941 			 */
3942 			rack_exit_probertt(rack, us_cts);
3943 		} else if (rack_probe_rtt_safety_val &&
3944 		    TSTMP_GT(us_cts, rack->r_ctl.rc_time_probertt_entered) &&
3945 		    ((us_cts - rack->r_ctl.rc_time_probertt_entered) > rack_probe_rtt_safety_val)) {
3946 			/*
3947 			 * Probe RTT safety value triggered!
3948 			 */
3949 			rack_log_rtt_shrinks(rack,  us_cts,
3950 					     get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt),
3951 					     __LINE__, RACK_RTTS_SAFETY);
3952 			rack_exit_probertt(rack, us_cts);
3953 		}
3954 		/* Calculate the max we will wait */
3955 		endtime = rack->r_ctl.rc_time_probertt_entered + (rack->r_ctl.rc_gp_srtt * rack_max_drain_wait);
3956 		if (rack->rc_highly_buffered)
3957 			endtime += (rack->r_ctl.rc_gp_srtt * rack_max_drain_hbp);
3958 		/* Calculate the min we must wait */
3959 		must_stay = rack->r_ctl.rc_time_probertt_entered + (rack->r_ctl.rc_gp_srtt * rack_must_drain);
3960 		if ((ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked) > rack->r_ctl.rc_target_probertt_flight) &&
3961 		    TSTMP_LT(us_cts, endtime)) {
3962 			uint32_t calc;
3963 			/* Do we lower more? */
3964 no_exit:
3965 			if (TSTMP_GT(us_cts, rack->r_ctl.rc_time_probertt_entered))
3966 				calc = us_cts - rack->r_ctl.rc_time_probertt_entered;
3967 			else
3968 				calc = 0;
3969 			calc /= max(rack->r_ctl.rc_gp_srtt, 1);
3970 			if (calc) {
3971 				/* Maybe */
3972 				calc *= rack_per_of_gp_probertt_reduce;
3973 				rack->r_ctl.rack_per_of_gp_probertt = rack_per_of_gp_probertt - calc;
3974 				/* Limit it too */
3975 				if (rack->r_ctl.rack_per_of_gp_probertt < rack_per_of_gp_lowthresh)
3976 					rack->r_ctl.rack_per_of_gp_probertt = rack_per_of_gp_lowthresh;
3977 			}
3978 			/* We must reach target or the time set */
3979 			return;
3980 		}
3981 		if (rack->r_ctl.rc_time_probertt_starts == 0) {
3982 			if ((TSTMP_LT(us_cts, must_stay) &&
3983 			     rack->rc_highly_buffered) ||
3984 			     (ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked) >
3985 			      rack->r_ctl.rc_target_probertt_flight)) {
3986 				/* We are not past the must_stay time */
3987 				goto no_exit;
3988 			}
3989 			rack_log_rtt_shrinks(rack,  us_cts,
3990 					     get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt),
3991 					     __LINE__, RACK_RTTS_REACHTARGET);
3992 			rack->r_ctl.rc_time_probertt_starts = us_cts;
3993 			if (rack->r_ctl.rc_time_probertt_starts == 0)
3994 				rack->r_ctl.rc_time_probertt_starts = 1;
3995 			/* Restore back to our rate we want to pace at in prtt */
3996 			rack->r_ctl.rack_per_of_gp_probertt = rack_per_of_gp_probertt;
3997 		}
3998 		/*
3999 		 * Setup our end time, some number of gp_srtts plus 200ms.
4000 		 */
4001 		no_overflow = ((uint64_t)rack->r_ctl.rc_gp_srtt *
4002 			       (uint64_t)rack_probertt_gpsrtt_cnt_mul);
4003 		if (rack_probertt_gpsrtt_cnt_div)
4004 			endtime = (uint32_t)(no_overflow / (uint64_t)rack_probertt_gpsrtt_cnt_div);
4005 		else
4006 			endtime = 0;
4007 		endtime += rack_min_probertt_hold;
4008 		endtime += rack->r_ctl.rc_time_probertt_starts;
4009 		if (TSTMP_GEQ(us_cts,  endtime)) {
4010 			/* yes, exit probertt */
4011 			rack_exit_probertt(rack, us_cts);
4012 		}
4013 
4014 	} else if ((us_cts - rack->r_ctl.rc_lower_rtt_us_cts) >= rack_time_between_probertt) {
4015 		/* Go into probertt, its been too long since we went lower */
4016 		rack_enter_probertt(rack, us_cts);
4017 	}
4018 }
4019 
4020 static void
4021 rack_update_multiplier(struct tcp_rack *rack, int32_t timely_says, uint64_t last_bw_est,
4022 		       uint32_t rtt, int32_t rtt_diff)
4023 {
4024 	uint64_t cur_bw, up_bnd, low_bnd, subfr;
4025 	uint32_t losses;
4026 
4027 	if ((rack->rc_gp_dyn_mul == 0) ||
4028 	    (rack->use_fixed_rate) ||
4029 	    (rack->in_probe_rtt) ||
4030 	    (rack->rc_always_pace == 0)) {
4031 		/* No dynamic GP multipler in play */
4032 		return;
4033 	}
4034 	losses = rack->r_ctl.rc_loss_count - rack->r_ctl.rc_loss_at_start;
4035 	cur_bw = rack_get_bw(rack);
4036 	/* Calculate our up and down range */
4037 	up_bnd = rack->r_ctl.last_gp_comp_bw * (uint64_t)rack_gp_per_bw_mul_up;
4038 	up_bnd /= 100;
4039 	up_bnd += rack->r_ctl.last_gp_comp_bw;
4040 
4041 	subfr = (uint64_t)rack->r_ctl.last_gp_comp_bw * (uint64_t)rack_gp_per_bw_mul_down;
4042 	subfr /= 100;
4043 	low_bnd = rack->r_ctl.last_gp_comp_bw - subfr;
4044 	if ((timely_says == 2) && (rack->r_ctl.rc_no_push_at_mrtt)) {
4045 		/*
4046 		 * This is the case where our RTT is above
4047 		 * the max target and we have been configured
4048 		 * to just do timely no bonus up stuff in that case.
4049 		 *
4050 		 * There are two configurations, set to 1, and we
4051 		 * just do timely if we are over our max. If its
4052 		 * set above 1 then we slam the multipliers down
4053 		 * to 100 and then decrement per timely.
4054 		 */
4055 		rack_log_timely(rack,  timely_says, cur_bw, low_bnd, up_bnd,
4056 				__LINE__, 3);
4057 		if (rack->r_ctl.rc_no_push_at_mrtt > 1)
4058 			rack_validate_multipliers_at_or_below_100(rack);
4059 		rack_decrease_bw_mul(rack, timely_says, rtt, rtt_diff);
4060 	} else if ((last_bw_est < low_bnd) && !losses) {
4061 		/*
4062 		 * We are decreasing this is a bit complicated this
4063 		 * means we are loosing ground. This could be
4064 		 * because another flow entered and we are competing
4065 		 * for b/w with it. This will push the RTT up which
4066 		 * makes timely unusable unless we want to get shoved
4067 		 * into a corner and just be backed off (the age
4068 		 * old problem with delay based CC).
4069 		 *
4070 		 * On the other hand if it was a route change we
4071 		 * would like to stay somewhat contained and not
4072 		 * blow out the buffers.
4073 		 */
4074 		rack_log_timely(rack,  timely_says, cur_bw, low_bnd, up_bnd,
4075 				__LINE__, 3);
4076 		rack->r_ctl.last_gp_comp_bw = cur_bw;
4077 		if (rack->rc_gp_bwred == 0) {
4078 			/* Go into reduction counting */
4079 			rack->rc_gp_bwred = 1;
4080 			rack->rc_gp_timely_dec_cnt = 0;
4081 		}
4082 		if ((rack->rc_gp_timely_dec_cnt < rack_timely_max_push_drop) ||
4083 		    (timely_says == 0)) {
4084 			/*
4085 			 * Push another time with a faster pacing
4086 			 * to try to gain back (we include override to
4087 			 * get a full raise factor).
4088 			 */
4089 			if ((rack->rc_gp_saw_ca && rack->r_ctl.rack_per_of_gp_ca <= rack_down_raise_thresh) ||
4090 			    (rack->rc_gp_saw_ss && rack->r_ctl.rack_per_of_gp_ss <= rack_down_raise_thresh) ||
4091 			    (timely_says == 0) ||
4092 			    (rack_down_raise_thresh == 0)) {
4093 				/*
4094 				 * Do an override up in b/w if we were
4095 				 * below the threshold or if the threshold
4096 				 * is zero we always do the raise.
4097 				 */
4098 				rack_increase_bw_mul(rack, timely_says, cur_bw, last_bw_est, 1);
4099 			} else {
4100 				/* Log it stays the same */
4101 				rack_log_timely(rack,  0, last_bw_est, low_bnd, 0,
4102 						__LINE__, 11);
4103 			}
4104 			rack->rc_gp_timely_dec_cnt++;
4105 			/* We are not incrementing really no-count */
4106 			rack->rc_gp_incr = 0;
4107 			rack->rc_gp_timely_inc_cnt = 0;
4108 		} else {
4109 			/*
4110 			 * Lets just use the RTT
4111 			 * information and give up
4112 			 * pushing.
4113 			 */
4114 			goto use_timely;
4115 		}
4116 	} else if ((timely_says != 2) &&
4117 		    !losses &&
4118 		    (last_bw_est > up_bnd)) {
4119 		/*
4120 		 * We are increasing b/w lets keep going, updating
4121 		 * our b/w and ignoring any timely input, unless
4122 		 * of course we are at our max raise (if there is one).
4123 		 */
4124 
4125 		rack_log_timely(rack,  timely_says, cur_bw, low_bnd, up_bnd,
4126 				__LINE__, 3);
4127 		rack->r_ctl.last_gp_comp_bw = cur_bw;
4128 		if (rack->rc_gp_saw_ss &&
4129 		    rack_per_upper_bound_ss &&
4130 		     (rack->r_ctl.rack_per_of_gp_ss == rack_per_upper_bound_ss)) {
4131 			    /*
4132 			     * In cases where we can't go higher
4133 			     * we should just use timely.
4134 			     */
4135 			    goto use_timely;
4136 		}
4137 		if (rack->rc_gp_saw_ca &&
4138 		    rack_per_upper_bound_ca &&
4139 		    (rack->r_ctl.rack_per_of_gp_ca == rack_per_upper_bound_ca)) {
4140 			    /*
4141 			     * In cases where we can't go higher
4142 			     * we should just use timely.
4143 			     */
4144 			    goto use_timely;
4145 		}
4146 		rack->rc_gp_bwred = 0;
4147 		rack->rc_gp_timely_dec_cnt = 0;
4148 		/* You get a set number of pushes if timely is trying to reduce */
4149 		if ((rack->rc_gp_incr < rack_timely_max_push_rise) || (timely_says == 0)) {
4150 			rack_increase_bw_mul(rack, timely_says, cur_bw, last_bw_est, 0);
4151 		} else {
4152 			/* Log it stays the same */
4153 			rack_log_timely(rack,  0, last_bw_est, up_bnd, 0,
4154 			    __LINE__, 12);
4155 		}
4156 		return;
4157 	} else {
4158 		/*
4159 		 * We are staying between the lower and upper range bounds
4160 		 * so use timely to decide.
4161 		 */
4162 		rack_log_timely(rack,  timely_says, cur_bw, low_bnd, up_bnd,
4163 				__LINE__, 3);
4164 use_timely:
4165 		if (timely_says) {
4166 			rack->rc_gp_incr = 0;
4167 			rack->rc_gp_timely_inc_cnt = 0;
4168 			if ((rack->rc_gp_timely_dec_cnt < rack_timely_max_push_drop) &&
4169 			    !losses &&
4170 			    (last_bw_est < low_bnd)) {
4171 				/* We are loosing ground */
4172 				rack_increase_bw_mul(rack, timely_says, cur_bw, last_bw_est, 0);
4173 				rack->rc_gp_timely_dec_cnt++;
4174 				/* We are not incrementing really no-count */
4175 				rack->rc_gp_incr = 0;
4176 				rack->rc_gp_timely_inc_cnt = 0;
4177 			} else
4178 				rack_decrease_bw_mul(rack, timely_says, rtt, rtt_diff);
4179 		} else {
4180 			rack->rc_gp_bwred = 0;
4181 			rack->rc_gp_timely_dec_cnt = 0;
4182 			rack_increase_bw_mul(rack, timely_says, cur_bw, last_bw_est, 0);
4183 		}
4184 	}
4185 }
4186 
4187 static int32_t
4188 rack_make_timely_judgement(struct tcp_rack *rack, uint32_t rtt, int32_t rtt_diff, uint32_t prev_rtt)
4189 {
4190 	int32_t timely_says;
4191 	uint64_t log_mult, log_rtt_a_diff;
4192 
4193 	log_rtt_a_diff = rtt;
4194 	log_rtt_a_diff <<= 32;
4195 	log_rtt_a_diff |= (uint32_t)rtt_diff;
4196 	if (rtt >= (get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt) *
4197 		    rack_gp_rtt_maxmul)) {
4198 		/* Reduce the b/w multipler */
4199 		timely_says = 2;
4200 		log_mult = get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt) * rack_gp_rtt_maxmul;
4201 		log_mult <<= 32;
4202 		log_mult |= prev_rtt;
4203 		rack_log_timely(rack,  timely_says, log_mult,
4204 				get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt),
4205 				log_rtt_a_diff, __LINE__, 4);
4206 	} else if (rtt <= (get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt) +
4207 			   ((get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt) * rack_gp_rtt_minmul) /
4208 			    max(rack_gp_rtt_mindiv , 1)))) {
4209 		/* Increase the b/w multipler */
4210 		log_mult = get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt) +
4211 			((get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt) * rack_gp_rtt_minmul) /
4212 			 max(rack_gp_rtt_mindiv , 1));
4213 		log_mult <<= 32;
4214 		log_mult |= prev_rtt;
4215 		timely_says = 0;
4216 		rack_log_timely(rack,  timely_says, log_mult ,
4217 				get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt),
4218 				log_rtt_a_diff, __LINE__, 5);
4219 	} else {
4220 		/*
4221 		 * Use a gradient to find it the timely gradient
4222 		 * is:
4223 		 * grad = rc_rtt_diff / min_rtt;
4224 		 *
4225 		 * anything below or equal to 0 will be
4226 		 * a increase indication. Anything above
4227 		 * zero is a decrease. Note we take care
4228 		 * of the actual gradient calculation
4229 		 * in the reduction (its not needed for
4230 		 * increase).
4231 		 */
4232 		log_mult = prev_rtt;
4233 		if (rtt_diff <= 0) {
4234 			/*
4235 			 * Rttdiff is less than zero, increase the
4236 			 * b/w multipler (its 0 or negative)
4237 			 */
4238 			timely_says = 0;
4239 			rack_log_timely(rack,  timely_says, log_mult,
4240 					get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt), log_rtt_a_diff, __LINE__, 6);
4241 		} else {
4242 			/* Reduce the b/w multipler */
4243 			timely_says = 1;
4244 			rack_log_timely(rack,  timely_says, log_mult,
4245 					get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt), log_rtt_a_diff, __LINE__, 7);
4246 		}
4247 	}
4248 	return (timely_says);
4249 }
4250 
4251 static void
4252 rack_do_goodput_measurement(struct tcpcb *tp, struct tcp_rack *rack,
4253 			    tcp_seq th_ack, int line, uint8_t quality)
4254 {
4255 	uint64_t tim, bytes_ps, ltim, stim, utim;
4256 	uint32_t segsiz, bytes, reqbytes, us_cts;
4257 	int32_t gput, new_rtt_diff, timely_says;
4258 	uint64_t  resid_bw, subpart = 0, addpart = 0, srtt;
4259 	int did_add = 0;
4260 
4261 	us_cts = tcp_tv_to_usectick(&rack->r_ctl.act_rcv_time);
4262 	segsiz = min(ctf_fixed_maxseg(tp), rack->r_ctl.rc_pace_min_segs);
4263 	if (TSTMP_GEQ(us_cts, tp->gput_ts))
4264 		tim = us_cts - tp->gput_ts;
4265 	else
4266 		tim = 0;
4267 	if (rack->r_ctl.rc_gp_cumack_ts > rack->r_ctl.rc_gp_output_ts)
4268 		stim = rack->r_ctl.rc_gp_cumack_ts - rack->r_ctl.rc_gp_output_ts;
4269 	else
4270 		stim = 0;
4271 	/*
4272 	 * Use the larger of the send time or ack time. This prevents us
4273 	 * from being influenced by ack artifacts to come up with too
4274 	 * high of measurement. Note that since we are spanning over many more
4275 	 * bytes in most of our measurements hopefully that is less likely to
4276 	 * occur.
4277 	 */
4278 	if (tim > stim)
4279 		utim = max(tim, 1);
4280 	else
4281 		utim = max(stim, 1);
4282 	/* Lets get a msec time ltim too for the old stuff */
4283 	ltim = max(1, (utim / HPTS_USEC_IN_MSEC));
4284 	gput = (((uint64_t) (th_ack - tp->gput_seq)) << 3) / ltim;
4285 	reqbytes = min(rc_init_window(rack), (MIN_GP_WIN * segsiz));
4286 	if ((tim == 0) && (stim == 0)) {
4287 		/*
4288 		 * Invalid measurement time, maybe
4289 		 * all on one ack/one send?
4290 		 */
4291 		bytes = 0;
4292 		bytes_ps = 0;
4293 		rack_log_pacing_delay_calc(rack, bytes_ps, reqbytes,
4294 					   0, 0, 0, 10, __LINE__, NULL, quality);
4295 		goto skip_measurement;
4296 	}
4297 	if (rack->r_ctl.rc_gp_lowrtt == 0xffffffff) {
4298 		/* We never made a us_rtt measurement? */
4299 		bytes = 0;
4300 		bytes_ps = 0;
4301 		rack_log_pacing_delay_calc(rack, bytes_ps, reqbytes,
4302 					   0, 0, 0, 10, __LINE__, NULL, quality);
4303 		goto skip_measurement;
4304 	}
4305 	/*
4306 	 * Calculate the maximum possible b/w this connection
4307 	 * could have. We base our calculation on the lowest
4308 	 * rtt we have seen during the measurement and the
4309 	 * largest rwnd the client has given us in that time. This
4310 	 * forms a BDP that is the maximum that we could ever
4311 	 * get to the client. Anything larger is not valid.
4312 	 *
4313 	 * I originally had code here that rejected measurements
4314 	 * where the time was less than 1/2 the latest us_rtt.
4315 	 * But after thinking on that I realized its wrong since
4316 	 * say you had a 150Mbps or even 1Gbps link, and you
4317 	 * were a long way away.. example I am in Europe (100ms rtt)
4318 	 * talking to my 1Gbps link in S.C. Now measuring say 150,000
4319 	 * bytes my time would be 1.2ms, and yet my rtt would say
4320 	 * the measurement was invalid the time was < 50ms. The
4321 	 * same thing is true for 150Mb (8ms of time).
4322 	 *
4323 	 * A better way I realized is to look at what the maximum
4324 	 * the connection could possibly do. This is gated on
4325 	 * the lowest RTT we have seen and the highest rwnd.
4326 	 * We should in theory never exceed that, if we are
4327 	 * then something on the path is storing up packets
4328 	 * and then feeding them all at once to our endpoint
4329 	 * messing up our measurement.
4330 	 */
4331 	rack->r_ctl.last_max_bw = rack->r_ctl.rc_gp_high_rwnd;
4332 	rack->r_ctl.last_max_bw *= HPTS_USEC_IN_SEC;
4333 	rack->r_ctl.last_max_bw /= rack->r_ctl.rc_gp_lowrtt;
4334 	if (SEQ_LT(th_ack, tp->gput_seq)) {
4335 		/* No measurement can be made */
4336 		bytes = 0;
4337 		bytes_ps = 0;
4338 		rack_log_pacing_delay_calc(rack, bytes_ps, reqbytes,
4339 					   0, 0, 0, 10, __LINE__, NULL, quality);
4340 		goto skip_measurement;
4341 	} else
4342 		bytes = (th_ack - tp->gput_seq);
4343 	bytes_ps = (uint64_t)bytes;
4344 	/*
4345 	 * Don't measure a b/w for pacing unless we have gotten at least
4346 	 * an initial windows worth of data in this measurement interval.
4347 	 *
4348 	 * Small numbers of bytes get badly influenced by delayed ack and
4349 	 * other artifacts. Note we take the initial window or our
4350 	 * defined minimum GP (defaulting to 10 which hopefully is the
4351 	 * IW).
4352 	 */
4353 	if (rack->rc_gp_filled == 0) {
4354 		/*
4355 		 * The initial estimate is special. We
4356 		 * have blasted out an IW worth of packets
4357 		 * without a real valid ack ts results. We
4358 		 * then setup the app_limited_needs_set flag,
4359 		 * this should get the first ack in (probably 2
4360 		 * MSS worth) to be recorded as the timestamp.
4361 		 * We thus allow a smaller number of bytes i.e.
4362 		 * IW - 2MSS.
4363 		 */
4364 		reqbytes -= (2 * segsiz);
4365 		/* Also lets fill previous for our first measurement to be neutral */
4366 		rack->r_ctl.rc_prev_gp_srtt = rack->r_ctl.rc_gp_srtt;
4367 	}
4368 	if ((bytes_ps < reqbytes) || rack->app_limited_needs_set) {
4369 		rack_log_pacing_delay_calc(rack, bytes_ps, reqbytes,
4370 					   rack->r_ctl.rc_app_limited_cnt,
4371 					   0, 0, 10, __LINE__, NULL, quality);
4372 		goto skip_measurement;
4373 	}
4374 	/*
4375 	 * We now need to calculate the Timely like status so
4376 	 * we can update (possibly) the b/w multipliers.
4377 	 */
4378 	new_rtt_diff = (int32_t)rack->r_ctl.rc_gp_srtt - (int32_t)rack->r_ctl.rc_prev_gp_srtt;
4379 	if (rack->rc_gp_filled == 0) {
4380 		/* No previous reading */
4381 		rack->r_ctl.rc_rtt_diff = new_rtt_diff;
4382 	} else {
4383 		if (rack->measure_saw_probe_rtt == 0) {
4384 			/*
4385 			 * We don't want a probertt to be counted
4386 			 * since it will be negative incorrectly. We
4387 			 * expect to be reducing the RTT when we
4388 			 * pace at a slower rate.
4389 			 */
4390 			rack->r_ctl.rc_rtt_diff -= (rack->r_ctl.rc_rtt_diff / 8);
4391 			rack->r_ctl.rc_rtt_diff += (new_rtt_diff / 8);
4392 		}
4393 	}
4394 	timely_says = rack_make_timely_judgement(rack,
4395 		rack->r_ctl.rc_gp_srtt,
4396 		rack->r_ctl.rc_rtt_diff,
4397 	        rack->r_ctl.rc_prev_gp_srtt
4398 		);
4399 	bytes_ps *= HPTS_USEC_IN_SEC;
4400 	bytes_ps /= utim;
4401 	if (bytes_ps > rack->r_ctl.last_max_bw) {
4402 		/*
4403 		 * Something is on path playing
4404 		 * since this b/w is not possible based
4405 		 * on our BDP (highest rwnd and lowest rtt
4406 		 * we saw in the measurement window).
4407 		 *
4408 		 * Another option here would be to
4409 		 * instead skip the measurement.
4410 		 */
4411 		rack_log_pacing_delay_calc(rack, bytes, reqbytes,
4412 					   bytes_ps, rack->r_ctl.last_max_bw, 0,
4413 					   11, __LINE__, NULL, quality);
4414 		bytes_ps = rack->r_ctl.last_max_bw;
4415 	}
4416 	/* We store gp for b/w in bytes per second */
4417 	if (rack->rc_gp_filled == 0) {
4418 		/* Initial measurment */
4419 		if (bytes_ps) {
4420 			rack->r_ctl.gp_bw = bytes_ps;
4421 			rack->rc_gp_filled = 1;
4422 			rack->r_ctl.num_measurements = 1;
4423 			rack_set_pace_segments(rack->rc_tp, rack, __LINE__, NULL);
4424 		} else {
4425 			rack_log_pacing_delay_calc(rack, bytes_ps, reqbytes,
4426 						   rack->r_ctl.rc_app_limited_cnt,
4427 						   0, 0, 10, __LINE__, NULL, quality);
4428 		}
4429 		if (rack->rc_inp->inp_in_hpts &&
4430 		    (rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT)) {
4431 			/*
4432 			 * Ok we can't trust the pacer in this case
4433 			 * where we transition from un-paced to paced.
4434 			 * Or for that matter when the burst mitigation
4435 			 * was making a wild guess and got it wrong.
4436 			 * Stop the pacer and clear up all the aggregate
4437 			 * delays etc.
4438 			 */
4439 			tcp_hpts_remove(rack->rc_inp, HPTS_REMOVE_OUTPUT);
4440 			rack->r_ctl.rc_hpts_flags = 0;
4441 			rack->r_ctl.rc_last_output_to = 0;
4442 		}
4443 		did_add = 2;
4444 	} else if (rack->r_ctl.num_measurements < RACK_REQ_AVG) {
4445 		/* Still a small number run an average */
4446 		rack->r_ctl.gp_bw += bytes_ps;
4447 		addpart = rack->r_ctl.num_measurements;
4448 		rack->r_ctl.num_measurements++;
4449 		if (rack->r_ctl.num_measurements >= RACK_REQ_AVG) {
4450 			/* We have collected enought to move forward */
4451 			rack->r_ctl.gp_bw /= (uint64_t)rack->r_ctl.num_measurements;
4452 		}
4453 		did_add = 3;
4454 	} else {
4455 		/*
4456 		 * We want to take 1/wma of the goodput and add in to 7/8th
4457 		 * of the old value weighted by the srtt. So if your measurement
4458 		 * period is say 2 SRTT's long you would get 1/4 as the
4459 		 * value, if it was like 1/2 SRTT then you would get 1/16th.
4460 		 *
4461 		 * But we must be careful not to take too much i.e. if the
4462 		 * srtt is say 20ms and the measurement is taken over
4463 		 * 400ms our weight would be 400/20 i.e. 20. On the
4464 		 * other hand if we get a measurement over 1ms with a
4465 		 * 10ms rtt we only want to take a much smaller portion.
4466 		 */
4467 		if (rack->r_ctl.num_measurements < 0xff) {
4468 			rack->r_ctl.num_measurements++;
4469 		}
4470 		srtt = (uint64_t)tp->t_srtt;
4471 		if (srtt == 0) {
4472 			/*
4473 			 * Strange why did t_srtt go back to zero?
4474 			 */
4475 			if (rack->r_ctl.rc_rack_min_rtt)
4476 				srtt = rack->r_ctl.rc_rack_min_rtt;
4477 			else
4478 				srtt = HPTS_USEC_IN_MSEC;
4479 		}
4480 		/*
4481 		 * XXXrrs: Note for reviewers, in playing with
4482 		 * dynamic pacing I discovered this GP calculation
4483 		 * as done originally leads to some undesired results.
4484 		 * Basically you can get longer measurements contributing
4485 		 * too much to the WMA. Thus I changed it if you are doing
4486 		 * dynamic adjustments to only do the aportioned adjustment
4487 		 * if we have a very small (time wise) measurement. Longer
4488 		 * measurements just get there weight (defaulting to 1/8)
4489 		 * add to the WMA. We may want to think about changing
4490 		 * this to always do that for both sides i.e. dynamic
4491 		 * and non-dynamic... but considering lots of folks
4492 		 * were playing with this I did not want to change the
4493 		 * calculation per.se. without your thoughts.. Lawerence?
4494 		 * Peter??
4495 		 */
4496 		if (rack->rc_gp_dyn_mul == 0) {
4497 			subpart = rack->r_ctl.gp_bw * utim;
4498 			subpart /= (srtt * 8);
4499 			if (subpart < (rack->r_ctl.gp_bw / 2)) {
4500 				/*
4501 				 * The b/w update takes no more
4502 				 * away then 1/2 our running total
4503 				 * so factor it in.
4504 				 */
4505 				addpart = bytes_ps * utim;
4506 				addpart /= (srtt * 8);
4507 			} else {
4508 				/*
4509 				 * Don't allow a single measurement
4510 				 * to account for more than 1/2 of the
4511 				 * WMA. This could happen on a retransmission
4512 				 * where utim becomes huge compared to
4513 				 * srtt (multiple retransmissions when using
4514 				 * the sending rate which factors in all the
4515 				 * transmissions from the first one).
4516 				 */
4517 				subpart = rack->r_ctl.gp_bw / 2;
4518 				addpart = bytes_ps / 2;
4519 			}
4520 			resid_bw = rack->r_ctl.gp_bw - subpart;
4521 			rack->r_ctl.gp_bw = resid_bw + addpart;
4522 			did_add = 1;
4523 		} else {
4524 			if ((utim / srtt) <= 1) {
4525 				/*
4526 				 * The b/w update was over a small period
4527 				 * of time. The idea here is to prevent a small
4528 				 * measurement time period from counting
4529 				 * too much. So we scale it based on the
4530 				 * time so it attributes less than 1/rack_wma_divisor
4531 				 * of its measurement.
4532 				 */
4533 				subpart = rack->r_ctl.gp_bw * utim;
4534 				subpart /= (srtt * rack_wma_divisor);
4535 				addpart = bytes_ps * utim;
4536 				addpart /= (srtt * rack_wma_divisor);
4537 			} else {
4538 				/*
4539 				 * The scaled measurement was long
4540 				 * enough so lets just add in the
4541 				 * portion of the measurment i.e. 1/rack_wma_divisor
4542 				 */
4543 				subpart = rack->r_ctl.gp_bw / rack_wma_divisor;
4544 				addpart = bytes_ps / rack_wma_divisor;
4545 			}
4546 			if ((rack->measure_saw_probe_rtt == 0) ||
4547 		            (bytes_ps > rack->r_ctl.gp_bw)) {
4548 				/*
4549 				 * For probe-rtt we only add it in
4550 				 * if its larger, all others we just
4551 				 * add in.
4552 				 */
4553 				did_add = 1;
4554 				resid_bw = rack->r_ctl.gp_bw - subpart;
4555 				rack->r_ctl.gp_bw = resid_bw + addpart;
4556 			}
4557 		}
4558 	}
4559 	if ((rack->gp_ready == 0) &&
4560 	    (rack->r_ctl.num_measurements >= rack->r_ctl.req_measurements)) {
4561 		/* We have enough measurements now */
4562 		rack->gp_ready = 1;
4563 		rack_set_cc_pacing(rack);
4564 		if (rack->defer_options)
4565 			rack_apply_deferred_options(rack);
4566 	}
4567 	rack_log_pacing_delay_calc(rack, subpart, addpart, bytes_ps, stim,
4568 				   rack_get_bw(rack), 22, did_add, NULL, quality);
4569 	/* We do not update any multipliers if we are in or have seen a probe-rtt */
4570 	if ((rack->measure_saw_probe_rtt == 0) && rack->rc_gp_rtt_set)
4571 		rack_update_multiplier(rack, timely_says, bytes_ps,
4572 				       rack->r_ctl.rc_gp_srtt,
4573 				       rack->r_ctl.rc_rtt_diff);
4574 	rack_log_pacing_delay_calc(rack, bytes, tim, bytes_ps, stim,
4575 				   rack_get_bw(rack), 3, line, NULL, quality);
4576 	/* reset the gp srtt and setup the new prev */
4577 	rack->r_ctl.rc_prev_gp_srtt = rack->r_ctl.rc_gp_srtt;
4578 	/* Record the lost count for the next measurement */
4579 	rack->r_ctl.rc_loss_at_start = rack->r_ctl.rc_loss_count;
4580 	/*
4581 	 * We restart our diffs based on the gpsrtt in the
4582 	 * measurement window.
4583 	 */
4584 	rack->rc_gp_rtt_set = 0;
4585 	rack->rc_gp_saw_rec = 0;
4586 	rack->rc_gp_saw_ca = 0;
4587 	rack->rc_gp_saw_ss = 0;
4588 	rack->rc_dragged_bottom = 0;
4589 skip_measurement:
4590 
4591 #ifdef STATS
4592 	stats_voi_update_abs_u32(tp->t_stats, VOI_TCP_GPUT,
4593 				 gput);
4594 	/*
4595 	 * XXXLAS: This is a temporary hack, and should be
4596 	 * chained off VOI_TCP_GPUT when stats(9) grows an
4597 	 * API to deal with chained VOIs.
4598 	 */
4599 	if (tp->t_stats_gput_prev > 0)
4600 		stats_voi_update_abs_s32(tp->t_stats,
4601 					 VOI_TCP_GPUT_ND,
4602 					 ((gput - tp->t_stats_gput_prev) * 100) /
4603 					 tp->t_stats_gput_prev);
4604 #endif
4605 	tp->t_flags &= ~TF_GPUTINPROG;
4606 	tp->t_stats_gput_prev = gput;
4607 	/*
4608 	 * Now are we app limited now and there is space from where we
4609 	 * were to where we want to go?
4610 	 *
4611 	 * We don't do the other case i.e. non-applimited here since
4612 	 * the next send will trigger us picking up the missing data.
4613 	 */
4614 	if (rack->r_ctl.rc_first_appl &&
4615 	    TCPS_HAVEESTABLISHED(tp->t_state) &&
4616 	    rack->r_ctl.rc_app_limited_cnt &&
4617 	    (SEQ_GT(rack->r_ctl.rc_first_appl->r_start, th_ack)) &&
4618 	    ((rack->r_ctl.rc_first_appl->r_end - th_ack) >
4619 	     max(rc_init_window(rack), (MIN_GP_WIN * segsiz)))) {
4620 		/*
4621 		 * Yep there is enough outstanding to make a measurement here.
4622 		 */
4623 		struct rack_sendmap *rsm, fe;
4624 
4625 		rack->r_ctl.rc_gp_lowrtt = 0xffffffff;
4626 		rack->r_ctl.rc_gp_high_rwnd = rack->rc_tp->snd_wnd;
4627 		tp->gput_ts = tcp_tv_to_usectick(&rack->r_ctl.act_rcv_time);
4628 		rack->app_limited_needs_set = 0;
4629 		tp->gput_seq = th_ack;
4630 		if (rack->in_probe_rtt)
4631 			rack->measure_saw_probe_rtt = 1;
4632 		else if ((rack->measure_saw_probe_rtt) &&
4633 			 (SEQ_GEQ(tp->gput_seq, rack->r_ctl.rc_probertt_sndmax_atexit)))
4634 			rack->measure_saw_probe_rtt = 0;
4635 		if ((rack->r_ctl.rc_first_appl->r_end - th_ack) >= rack_get_measure_window(tp, rack)) {
4636 			/* There is a full window to gain info from */
4637 			tp->gput_ack = tp->gput_seq + rack_get_measure_window(tp, rack);
4638 		} else {
4639 			/* We can only measure up to the applimited point */
4640 			tp->gput_ack = tp->gput_seq + (rack->r_ctl.rc_first_appl->r_end - th_ack);
4641 			if ((tp->gput_ack - tp->gput_seq) < (MIN_GP_WIN * segsiz)) {
4642 				/*
4643 				 * We don't have enough to make a measurement.
4644 				 */
4645 				tp->t_flags &= ~TF_GPUTINPROG;
4646 				rack_log_pacing_delay_calc(rack, tp->gput_ack, tp->gput_seq,
4647 							   0, 0, 0, 6, __LINE__, NULL, quality);
4648 				return;
4649 			}
4650 		}
4651 		if (tp->t_state >= TCPS_FIN_WAIT_1) {
4652 			/*
4653 			 * We will get no more data into the SB
4654 			 * this means we need to have the data available
4655 			 * before we start a measurement.
4656 			 */
4657 			if (sbavail(&tp->t_inpcb->inp_socket->so_snd) < (tp->gput_ack - tp->gput_seq)) {
4658 				/* Nope not enough data. */
4659 				return;
4660 			}
4661 		}
4662 		tp->t_flags |= TF_GPUTINPROG;
4663 		/*
4664 		 * Now we need to find the timestamp of the send at tp->gput_seq
4665 		 * for the send based measurement.
4666 		 */
4667 		fe.r_start = tp->gput_seq;
4668 		rsm = RB_FIND(rack_rb_tree_head, &rack->r_ctl.rc_mtree, &fe);
4669 		if (rsm) {
4670 			/* Ok send-based limit is set */
4671 			if (SEQ_LT(rsm->r_start, tp->gput_seq)) {
4672 				/*
4673 				 * Move back to include the earlier part
4674 				 * so our ack time lines up right (this may
4675 				 * make an overlapping measurement but thats
4676 				 * ok).
4677 				 */
4678 				tp->gput_seq = rsm->r_start;
4679 			}
4680 			if (rsm->r_flags & RACK_ACKED)
4681 				tp->gput_ts = (uint32_t)rsm->r_ack_arrival;
4682 			else
4683 				rack->app_limited_needs_set = 1;
4684 			rack->r_ctl.rc_gp_output_ts = rsm->r_tim_lastsent[(rsm->r_rtr_cnt-1)];
4685 		} else {
4686 			/*
4687 			 * If we don't find the rsm due to some
4688 			 * send-limit set the current time, which
4689 			 * basically disables the send-limit.
4690 			 */
4691 			struct timeval tv;
4692 
4693 			microuptime(&tv);
4694 			rack->r_ctl.rc_gp_output_ts = rack_to_usec_ts(&tv);
4695 		}
4696 		rack_log_pacing_delay_calc(rack,
4697 					   tp->gput_seq,
4698 					   tp->gput_ack,
4699 					   (uint64_t)rsm,
4700 					   tp->gput_ts,
4701 					   rack->r_ctl.rc_app_limited_cnt,
4702 					   9,
4703 					   __LINE__, NULL, quality);
4704 	}
4705 }
4706 
4707 /*
4708  * CC wrapper hook functions
4709  */
4710 static void
4711 rack_ack_received(struct tcpcb *tp, struct tcp_rack *rack, uint32_t th_ack, uint16_t nsegs,
4712     uint16_t type, int32_t recovery)
4713 {
4714 	uint32_t prior_cwnd, acked;
4715 	struct tcp_log_buffer *lgb = NULL;
4716 	uint8_t labc_to_use, quality;
4717 
4718 	INP_WLOCK_ASSERT(tp->t_inpcb);
4719 	tp->ccv->nsegs = nsegs;
4720 	acked = tp->ccv->bytes_this_ack = (th_ack - tp->snd_una);
4721 	if ((recovery) && (rack->r_ctl.rc_early_recovery_segs)) {
4722 		uint32_t max;
4723 
4724 		max = rack->r_ctl.rc_early_recovery_segs * ctf_fixed_maxseg(tp);
4725 		if (tp->ccv->bytes_this_ack > max) {
4726 			tp->ccv->bytes_this_ack = max;
4727 		}
4728 	}
4729 #ifdef STATS
4730 	stats_voi_update_abs_s32(tp->t_stats, VOI_TCP_CALCFRWINDIFF,
4731 	    ((int32_t)rack->r_ctl.cwnd_to_use) - tp->snd_wnd);
4732 #endif
4733 	quality = RACK_QUALITY_NONE;
4734 	if ((tp->t_flags & TF_GPUTINPROG) &&
4735 	    rack_enough_for_measurement(tp, rack, th_ack, &quality)) {
4736 		/* Measure the Goodput */
4737 		rack_do_goodput_measurement(tp, rack, th_ack, __LINE__, quality);
4738 #ifdef NETFLIX_PEAKRATE
4739 		if ((type == CC_ACK) &&
4740 		    (tp->t_maxpeakrate)) {
4741 			/*
4742 			 * We update t_peakrate_thr. This gives us roughly
4743 			 * one update per round trip time. Note
4744 			 * it will only be used if pace_always is off i.e
4745 			 * we don't do this for paced flows.
4746 			 */
4747 			rack_update_peakrate_thr(tp);
4748 		}
4749 #endif
4750 	}
4751 	/* Which way our we limited, if not cwnd limited no advance in CA */
4752 	if (tp->snd_cwnd <= tp->snd_wnd)
4753 		tp->ccv->flags |= CCF_CWND_LIMITED;
4754 	else
4755 		tp->ccv->flags &= ~CCF_CWND_LIMITED;
4756 	if (tp->snd_cwnd > tp->snd_ssthresh) {
4757 		tp->t_bytes_acked += min(tp->ccv->bytes_this_ack,
4758 			 nsegs * V_tcp_abc_l_var * ctf_fixed_maxseg(tp));
4759 		/* For the setting of a window past use the actual scwnd we are using */
4760 		if (tp->t_bytes_acked >= rack->r_ctl.cwnd_to_use) {
4761 			tp->t_bytes_acked -= rack->r_ctl.cwnd_to_use;
4762 			tp->ccv->flags |= CCF_ABC_SENTAWND;
4763 		}
4764 	} else {
4765 		tp->ccv->flags &= ~CCF_ABC_SENTAWND;
4766 		tp->t_bytes_acked = 0;
4767 	}
4768 	prior_cwnd = tp->snd_cwnd;
4769 	if ((recovery == 0) || (rack_max_abc_post_recovery == 0) || rack->r_use_labc_for_rec ||
4770 	    (rack_client_low_buf && (rack->client_bufferlvl < rack_client_low_buf)))
4771 		labc_to_use = rack->rc_labc;
4772 	else
4773 		labc_to_use = rack_max_abc_post_recovery;
4774 	if (rack_verbose_logging && (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF)) {
4775 		union tcp_log_stackspecific log;
4776 		struct timeval tv;
4777 
4778 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
4779 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
4780 		log.u_bbr.flex1 = th_ack;
4781 		log.u_bbr.flex2 = tp->ccv->flags;
4782 		log.u_bbr.flex3 = tp->ccv->bytes_this_ack;
4783 		log.u_bbr.flex4 = tp->ccv->nsegs;
4784 		log.u_bbr.flex5 = labc_to_use;
4785 		log.u_bbr.flex6 = prior_cwnd;
4786 		log.u_bbr.flex7 = V_tcp_do_newsack;
4787 		log.u_bbr.flex8 = 1;
4788 		lgb = tcp_log_event_(tp, NULL, NULL, NULL, BBR_LOG_CWND, 0,
4789 				     0, &log, false, NULL, NULL, 0, &tv);
4790 	}
4791 	if (CC_ALGO(tp)->ack_received != NULL) {
4792 		/* XXXLAS: Find a way to live without this */
4793 		tp->ccv->curack = th_ack;
4794 		tp->ccv->labc = labc_to_use;
4795 		tp->ccv->flags |= CCF_USE_LOCAL_ABC;
4796 		CC_ALGO(tp)->ack_received(tp->ccv, type);
4797 	}
4798 	if (lgb) {
4799 		lgb->tlb_stackinfo.u_bbr.flex6 = tp->snd_cwnd;
4800 	}
4801 	if (rack->r_must_retran) {
4802 		if (SEQ_GEQ(th_ack, rack->r_ctl.rc_snd_max_at_rto)) {
4803 			/*
4804 			 * We now are beyond the rxt point so lets disable
4805 			 * the flag.
4806 			 */
4807 			rack->r_ctl.rc_out_at_rto = 0;
4808 			rack->r_must_retran = 0;
4809 		} else if ((prior_cwnd + ctf_fixed_maxseg(tp)) <= tp->snd_cwnd) {
4810 			/*
4811 			 * Only decrement the rc_out_at_rto if the cwnd advances
4812 			 * at least a whole segment. Otherwise next time the peer
4813 			 * acks, we won't be able to send this generaly happens
4814 			 * when we are in Congestion Avoidance.
4815 			 */
4816 			if (acked <= rack->r_ctl.rc_out_at_rto){
4817 				rack->r_ctl.rc_out_at_rto -= acked;
4818 			} else {
4819 				rack->r_ctl.rc_out_at_rto = 0;
4820 			}
4821 		}
4822 	}
4823 #ifdef STATS
4824 	stats_voi_update_abs_ulong(tp->t_stats, VOI_TCP_LCWIN, rack->r_ctl.cwnd_to_use);
4825 #endif
4826 	if (rack->r_ctl.rc_rack_largest_cwnd < rack->r_ctl.cwnd_to_use) {
4827 		rack->r_ctl.rc_rack_largest_cwnd = rack->r_ctl.cwnd_to_use;
4828 	}
4829 #ifdef NETFLIX_PEAKRATE
4830 	/* we enforce max peak rate if it is set and we are not pacing */
4831 	if ((rack->rc_always_pace == 0) &&
4832 	    tp->t_peakrate_thr &&
4833 	    (tp->snd_cwnd > tp->t_peakrate_thr)) {
4834 		tp->snd_cwnd = tp->t_peakrate_thr;
4835 	}
4836 #endif
4837 }
4838 
4839 static void
4840 tcp_rack_partialack(struct tcpcb *tp)
4841 {
4842 	struct tcp_rack *rack;
4843 
4844 	rack = (struct tcp_rack *)tp->t_fb_ptr;
4845 	INP_WLOCK_ASSERT(tp->t_inpcb);
4846 	/*
4847 	 * If we are doing PRR and have enough
4848 	 * room to send <or> we are pacing and prr
4849 	 * is disabled we will want to see if we
4850 	 * can send data (by setting r_wanted_output to
4851 	 * true).
4852 	 */
4853 	if ((rack->r_ctl.rc_prr_sndcnt > 0) ||
4854 	    rack->rack_no_prr)
4855 		rack->r_wanted_output = 1;
4856 }
4857 
4858 static void
4859 rack_post_recovery(struct tcpcb *tp, uint32_t th_ack)
4860 {
4861 	struct tcp_rack *rack;
4862 	uint32_t orig_cwnd;
4863 
4864 	orig_cwnd = tp->snd_cwnd;
4865 	INP_WLOCK_ASSERT(tp->t_inpcb);
4866 	rack = (struct tcp_rack *)tp->t_fb_ptr;
4867 	/* only alert CC if we alerted when we entered */
4868 	if (CC_ALGO(tp)->post_recovery != NULL) {
4869 		tp->ccv->curack = th_ack;
4870 		CC_ALGO(tp)->post_recovery(tp->ccv);
4871 		if (tp->snd_cwnd < tp->snd_ssthresh) {
4872 			/*
4873 			 * Rack has burst control and pacing
4874 			 * so lets not set this any lower than
4875 			 * snd_ssthresh per RFC-6582 (option 2).
4876 			 */
4877 			tp->snd_cwnd = tp->snd_ssthresh;
4878 		}
4879 	}
4880 	if (rack_verbose_logging && (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF)) {
4881 		union tcp_log_stackspecific log;
4882 		struct timeval tv;
4883 
4884 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
4885 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
4886 		log.u_bbr.flex1 = th_ack;
4887 		log.u_bbr.flex2 = tp->ccv->flags;
4888 		log.u_bbr.flex3 = tp->ccv->bytes_this_ack;
4889 		log.u_bbr.flex4 = tp->ccv->nsegs;
4890 		log.u_bbr.flex5 = V_tcp_abc_l_var;
4891 		log.u_bbr.flex6 = orig_cwnd;
4892 		log.u_bbr.flex7 = V_tcp_do_newsack;
4893 		log.u_bbr.pkts_out = rack->r_ctl.rc_prr_sndcnt;
4894 		log.u_bbr.flex8 = 2;
4895 		tcp_log_event_(tp, NULL, NULL, NULL, BBR_LOG_CWND, 0,
4896 			       0, &log, false, NULL, NULL, 0, &tv);
4897 	}
4898 	if ((rack->rack_no_prr == 0) &&
4899 	    (rack->no_prr_addback == 0) &&
4900 	    (rack->r_ctl.rc_prr_sndcnt > 0)) {
4901 		/*
4902 		 * Suck the next prr cnt back into cwnd, but
4903 		 * only do that if we are not application limited.
4904 		 */
4905 		if (ctf_outstanding(tp) <= sbavail(&(tp->t_inpcb->inp_socket->so_snd))) {
4906 			/*
4907 			 * We are allowed to add back to the cwnd the amount we did
4908 			 * not get out if:
4909 			 * a) no_prr_addback is off.
4910 			 * b) we are not app limited
4911 			 * c) we are doing prr
4912 			 * <and>
4913 			 * d) it is bounded by rack_prr_addbackmax (if addback is 0, then none).
4914 			 */
4915 			tp->snd_cwnd += min((ctf_fixed_maxseg(tp) * rack_prr_addbackmax),
4916 					    rack->r_ctl.rc_prr_sndcnt);
4917 		}
4918 		rack->r_ctl.rc_prr_sndcnt = 0;
4919 		rack_log_to_prr(rack, 1, 0);
4920 	}
4921 	rack_log_to_prr(rack, 14, orig_cwnd);
4922 	tp->snd_recover = tp->snd_una;
4923 	if (rack->r_ctl.dsack_persist) {
4924 		rack->r_ctl.dsack_persist--;
4925 		if (rack->r_ctl.num_dsack && (rack->r_ctl.dsack_persist == 0)) {
4926 			rack->r_ctl.num_dsack = 0;
4927 		}
4928 		rack_log_dsack_event(rack, 1, __LINE__, 0, 0);
4929 	}
4930 	EXIT_RECOVERY(tp->t_flags);
4931 }
4932 
4933 static void
4934 rack_cong_signal(struct tcpcb *tp, uint32_t type, uint32_t ack)
4935 {
4936 	struct tcp_rack *rack;
4937 	uint32_t ssthresh_enter, cwnd_enter, in_rec_at_entry, orig_cwnd;
4938 
4939 	INP_WLOCK_ASSERT(tp->t_inpcb);
4940 #ifdef STATS
4941 	stats_voi_update_abs_u32(tp->t_stats, VOI_TCP_CSIG, type);
4942 #endif
4943 	if (IN_RECOVERY(tp->t_flags) == 0) {
4944 		in_rec_at_entry = 0;
4945 		ssthresh_enter = tp->snd_ssthresh;
4946 		cwnd_enter = tp->snd_cwnd;
4947 	} else
4948 		in_rec_at_entry = 1;
4949 	rack = (struct tcp_rack *)tp->t_fb_ptr;
4950 	switch (type) {
4951 	case CC_NDUPACK:
4952 		tp->t_flags &= ~TF_WASFRECOVERY;
4953 		tp->t_flags &= ~TF_WASCRECOVERY;
4954 		if (!IN_FASTRECOVERY(tp->t_flags)) {
4955 			rack->r_ctl.rc_prr_delivered = 0;
4956 			rack->r_ctl.rc_prr_out = 0;
4957 			if (rack->rack_no_prr == 0) {
4958 				rack->r_ctl.rc_prr_sndcnt = ctf_fixed_maxseg(tp);
4959 				rack_log_to_prr(rack, 2, in_rec_at_entry);
4960 			}
4961 			rack->r_ctl.rc_prr_recovery_fs = tp->snd_max - tp->snd_una;
4962 			tp->snd_recover = tp->snd_max;
4963 			if (tp->t_flags2 & TF2_ECN_PERMIT)
4964 				tp->t_flags2 |= TF2_ECN_SND_CWR;
4965 		}
4966 		break;
4967 	case CC_ECN:
4968 		if (!IN_CONGRECOVERY(tp->t_flags) ||
4969 		    /*
4970 		     * Allow ECN reaction on ACK to CWR, if
4971 		     * that data segment was also CE marked.
4972 		     */
4973 		    SEQ_GEQ(ack, tp->snd_recover)) {
4974 			EXIT_CONGRECOVERY(tp->t_flags);
4975 			KMOD_TCPSTAT_INC(tcps_ecn_rcwnd);
4976 			tp->snd_recover = tp->snd_max + 1;
4977 			if (tp->t_flags2 & TF2_ECN_PERMIT)
4978 				tp->t_flags2 |= TF2_ECN_SND_CWR;
4979 		}
4980 		break;
4981 	case CC_RTO:
4982 		tp->t_dupacks = 0;
4983 		tp->t_bytes_acked = 0;
4984 		EXIT_RECOVERY(tp->t_flags);
4985 		tp->snd_ssthresh = max(2, min(tp->snd_wnd, rack->r_ctl.cwnd_to_use) / 2 /
4986 		    ctf_fixed_maxseg(tp)) * ctf_fixed_maxseg(tp);
4987 		orig_cwnd = tp->snd_cwnd;
4988 		tp->snd_cwnd = ctf_fixed_maxseg(tp);
4989 		rack_log_to_prr(rack, 16, orig_cwnd);
4990 		if (tp->t_flags2 & TF2_ECN_PERMIT)
4991 			tp->t_flags2 |= TF2_ECN_SND_CWR;
4992 		break;
4993 	case CC_RTO_ERR:
4994 		KMOD_TCPSTAT_INC(tcps_sndrexmitbad);
4995 		/* RTO was unnecessary, so reset everything. */
4996 		tp->snd_cwnd = tp->snd_cwnd_prev;
4997 		tp->snd_ssthresh = tp->snd_ssthresh_prev;
4998 		tp->snd_recover = tp->snd_recover_prev;
4999 		if (tp->t_flags & TF_WASFRECOVERY) {
5000 			ENTER_FASTRECOVERY(tp->t_flags);
5001 			tp->t_flags &= ~TF_WASFRECOVERY;
5002 		}
5003 		if (tp->t_flags & TF_WASCRECOVERY) {
5004 			ENTER_CONGRECOVERY(tp->t_flags);
5005 			tp->t_flags &= ~TF_WASCRECOVERY;
5006 		}
5007 		tp->snd_nxt = tp->snd_max;
5008 		tp->t_badrxtwin = 0;
5009 		break;
5010 	}
5011 	if ((CC_ALGO(tp)->cong_signal != NULL)  &&
5012 	    (type != CC_RTO)){
5013 		tp->ccv->curack = ack;
5014 		CC_ALGO(tp)->cong_signal(tp->ccv, type);
5015 	}
5016 	if ((in_rec_at_entry == 0) && IN_RECOVERY(tp->t_flags)) {
5017 		rack_log_to_prr(rack, 15, cwnd_enter);
5018 		rack->r_ctl.dsack_byte_cnt = 0;
5019 		rack->r_ctl.retran_during_recovery = 0;
5020 		rack->r_ctl.rc_cwnd_at_erec = cwnd_enter;
5021 		rack->r_ctl.rc_ssthresh_at_erec = ssthresh_enter;
5022 		rack->r_ent_rec_ns = 1;
5023 	}
5024 }
5025 
5026 static inline void
5027 rack_cc_after_idle(struct tcp_rack *rack, struct tcpcb *tp)
5028 {
5029 	uint32_t i_cwnd;
5030 
5031 	INP_WLOCK_ASSERT(tp->t_inpcb);
5032 
5033 #ifdef NETFLIX_STATS
5034 	KMOD_TCPSTAT_INC(tcps_idle_restarts);
5035 	if (tp->t_state == TCPS_ESTABLISHED)
5036 		KMOD_TCPSTAT_INC(tcps_idle_estrestarts);
5037 #endif
5038 	if (CC_ALGO(tp)->after_idle != NULL)
5039 		CC_ALGO(tp)->after_idle(tp->ccv);
5040 
5041 	if (tp->snd_cwnd == 1)
5042 		i_cwnd = tp->t_maxseg;		/* SYN(-ACK) lost */
5043 	else
5044 		i_cwnd = rc_init_window(rack);
5045 
5046 	/*
5047 	 * Being idle is no differnt than the initial window. If the cc
5048 	 * clamps it down below the initial window raise it to the initial
5049 	 * window.
5050 	 */
5051 	if (tp->snd_cwnd < i_cwnd) {
5052 		tp->snd_cwnd = i_cwnd;
5053 	}
5054 }
5055 
5056 /*
5057  * Indicate whether this ack should be delayed.  We can delay the ack if
5058  * following conditions are met:
5059  *	- There is no delayed ack timer in progress.
5060  *	- Our last ack wasn't a 0-sized window. We never want to delay
5061  *	  the ack that opens up a 0-sized window.
5062  *	- LRO wasn't used for this segment. We make sure by checking that the
5063  *	  segment size is not larger than the MSS.
5064  *	- Delayed acks are enabled or this is a half-synchronized T/TCP
5065  *	  connection.
5066  */
5067 #define DELAY_ACK(tp, tlen)			 \
5068 	(((tp->t_flags & TF_RXWIN0SENT) == 0) && \
5069 	((tp->t_flags & TF_DELACK) == 0) &&	 \
5070 	(tlen <= tp->t_maxseg) &&		 \
5071 	(tp->t_delayed_ack || (tp->t_flags & TF_NEEDSYN)))
5072 
5073 static struct rack_sendmap *
5074 rack_find_lowest_rsm(struct tcp_rack *rack)
5075 {
5076 	struct rack_sendmap *rsm;
5077 
5078 	/*
5079 	 * Walk the time-order transmitted list looking for an rsm that is
5080 	 * not acked. This will be the one that was sent the longest time
5081 	 * ago that is still outstanding.
5082 	 */
5083 	TAILQ_FOREACH(rsm, &rack->r_ctl.rc_tmap, r_tnext) {
5084 		if (rsm->r_flags & RACK_ACKED) {
5085 			continue;
5086 		}
5087 		goto finish;
5088 	}
5089 finish:
5090 	return (rsm);
5091 }
5092 
5093 static struct rack_sendmap *
5094 rack_find_high_nonack(struct tcp_rack *rack, struct rack_sendmap *rsm)
5095 {
5096 	struct rack_sendmap *prsm;
5097 
5098 	/*
5099 	 * Walk the sequence order list backward until we hit and arrive at
5100 	 * the highest seq not acked. In theory when this is called it
5101 	 * should be the last segment (which it was not).
5102 	 */
5103 	counter_u64_add(rack_find_high, 1);
5104 	prsm = rsm;
5105 	RB_FOREACH_REVERSE_FROM(prsm, rack_rb_tree_head, rsm) {
5106 		if (prsm->r_flags & (RACK_ACKED | RACK_HAS_FIN)) {
5107 			continue;
5108 		}
5109 		return (prsm);
5110 	}
5111 	return (NULL);
5112 }
5113 
5114 static uint32_t
5115 rack_calc_thresh_rack(struct tcp_rack *rack, uint32_t srtt, uint32_t cts)
5116 {
5117 	int32_t lro;
5118 	uint32_t thresh;
5119 
5120 	/*
5121 	 * lro is the flag we use to determine if we have seen reordering.
5122 	 * If it gets set we have seen reordering. The reorder logic either
5123 	 * works in one of two ways:
5124 	 *
5125 	 * If reorder-fade is configured, then we track the last time we saw
5126 	 * re-ordering occur. If we reach the point where enough time as
5127 	 * passed we no longer consider reordering has occuring.
5128 	 *
5129 	 * Or if reorder-face is 0, then once we see reordering we consider
5130 	 * the connection to alway be subject to reordering and just set lro
5131 	 * to 1.
5132 	 *
5133 	 * In the end if lro is non-zero we add the extra time for
5134 	 * reordering in.
5135 	 */
5136 	if (srtt == 0)
5137 		srtt = 1;
5138 	if (rack->r_ctl.rc_reorder_ts) {
5139 		if (rack->r_ctl.rc_reorder_fade) {
5140 			if (SEQ_GEQ(cts, rack->r_ctl.rc_reorder_ts)) {
5141 				lro = cts - rack->r_ctl.rc_reorder_ts;
5142 				if (lro == 0) {
5143 					/*
5144 					 * No time as passed since the last
5145 					 * reorder, mark it as reordering.
5146 					 */
5147 					lro = 1;
5148 				}
5149 			} else {
5150 				/* Negative time? */
5151 				lro = 0;
5152 			}
5153 			if (lro > rack->r_ctl.rc_reorder_fade) {
5154 				/* Turn off reordering seen too */
5155 				rack->r_ctl.rc_reorder_ts = 0;
5156 				lro = 0;
5157 			}
5158 		} else {
5159 			/* Reodering does not fade */
5160 			lro = 1;
5161 		}
5162 	} else {
5163 		lro = 0;
5164 	}
5165 	if (rack->rc_rack_tmr_std_based == 0) {
5166 		thresh = srtt + rack->r_ctl.rc_pkt_delay;
5167 	} else {
5168 		/* Standards based pkt-delay is 1/4 srtt */
5169 		thresh = srtt +  (srtt >> 2);
5170 	}
5171 	if (lro && (rack->rc_rack_tmr_std_based == 0)) {
5172 		/* It must be set, if not you get 1/4 rtt */
5173 		if (rack->r_ctl.rc_reorder_shift)
5174 			thresh += (srtt >> rack->r_ctl.rc_reorder_shift);
5175 		else
5176 			thresh += (srtt >> 2);
5177 	}
5178 	if (rack->rc_rack_use_dsack &&
5179 	    lro &&
5180 	    (rack->r_ctl.num_dsack > 0)) {
5181 		/*
5182 		 * We only increase the reordering window if we
5183 		 * have seen reordering <and> we have a DSACK count.
5184 		 */
5185 		thresh += rack->r_ctl.num_dsack * (srtt >> 2);
5186 		rack_log_dsack_event(rack, 4, __LINE__, srtt, thresh);
5187 	}
5188 	/* SRTT * 2 is the ceiling */
5189 	if (thresh > (srtt * 2)) {
5190 		thresh = srtt * 2;
5191 	}
5192 	/* And we don't want it above the RTO max either */
5193 	if (thresh > rack_rto_max) {
5194 		thresh = rack_rto_max;
5195 	}
5196 	rack_log_dsack_event(rack, 6, __LINE__, srtt, thresh);
5197 	return (thresh);
5198 }
5199 
5200 static uint32_t
5201 rack_calc_thresh_tlp(struct tcpcb *tp, struct tcp_rack *rack,
5202 		     struct rack_sendmap *rsm, uint32_t srtt)
5203 {
5204 	struct rack_sendmap *prsm;
5205 	uint32_t thresh, len;
5206 	int segsiz;
5207 
5208 	if (srtt == 0)
5209 		srtt = 1;
5210 	if (rack->r_ctl.rc_tlp_threshold)
5211 		thresh = srtt + (srtt / rack->r_ctl.rc_tlp_threshold);
5212 	else
5213 		thresh = (srtt * 2);
5214 
5215 	/* Get the previous sent packet, if any */
5216 	segsiz = min(ctf_fixed_maxseg(tp), rack->r_ctl.rc_pace_min_segs);
5217 	counter_u64_add(rack_enter_tlp_calc, 1);
5218 	len = rsm->r_end - rsm->r_start;
5219 	if (rack->rack_tlp_threshold_use == TLP_USE_ID) {
5220 		/* Exactly like the ID */
5221 		if (((tp->snd_max - tp->snd_una) - rack->r_ctl.rc_sacked + rack->r_ctl.rc_holes_rxt) <= segsiz) {
5222 			uint32_t alt_thresh;
5223 			/*
5224 			 * Compensate for delayed-ack with the d-ack time.
5225 			 */
5226 			counter_u64_add(rack_used_tlpmethod, 1);
5227 			alt_thresh = srtt + (srtt / 2) + rack_delayed_ack_time;
5228 			if (alt_thresh > thresh)
5229 				thresh = alt_thresh;
5230 		}
5231 	} else if (rack->rack_tlp_threshold_use == TLP_USE_TWO_ONE) {
5232 		/* 2.1 behavior */
5233 		prsm = TAILQ_PREV(rsm, rack_head, r_tnext);
5234 		if (prsm && (len <= segsiz)) {
5235 			/*
5236 			 * Two packets outstanding, thresh should be (2*srtt) +
5237 			 * possible inter-packet delay (if any).
5238 			 */
5239 			uint32_t inter_gap = 0;
5240 			int idx, nidx;
5241 
5242 			counter_u64_add(rack_used_tlpmethod, 1);
5243 			idx = rsm->r_rtr_cnt - 1;
5244 			nidx = prsm->r_rtr_cnt - 1;
5245 			if (rsm->r_tim_lastsent[nidx] >= prsm->r_tim_lastsent[idx]) {
5246 				/* Yes it was sent later (or at the same time) */
5247 				inter_gap = rsm->r_tim_lastsent[idx] - prsm->r_tim_lastsent[nidx];
5248 			}
5249 			thresh += inter_gap;
5250 		} else if (len <= segsiz) {
5251 			/*
5252 			 * Possibly compensate for delayed-ack.
5253 			 */
5254 			uint32_t alt_thresh;
5255 
5256 			counter_u64_add(rack_used_tlpmethod2, 1);
5257 			alt_thresh = srtt + (srtt / 2) + rack_delayed_ack_time;
5258 			if (alt_thresh > thresh)
5259 				thresh = alt_thresh;
5260 		}
5261 	} else if (rack->rack_tlp_threshold_use == TLP_USE_TWO_TWO) {
5262 		/* 2.2 behavior */
5263 		if (len <= segsiz) {
5264 			uint32_t alt_thresh;
5265 			/*
5266 			 * Compensate for delayed-ack with the d-ack time.
5267 			 */
5268 			counter_u64_add(rack_used_tlpmethod, 1);
5269 			alt_thresh = srtt + (srtt / 2) + rack_delayed_ack_time;
5270 			if (alt_thresh > thresh)
5271 				thresh = alt_thresh;
5272 		}
5273 	}
5274 	/* Not above an RTO */
5275 	if (thresh > tp->t_rxtcur) {
5276 		thresh = tp->t_rxtcur;
5277 	}
5278 	/* Not above a RTO max */
5279 	if (thresh > rack_rto_max) {
5280 		thresh = rack_rto_max;
5281 	}
5282 	/* Apply user supplied min TLP */
5283 	if (thresh < rack_tlp_min) {
5284 		thresh = rack_tlp_min;
5285 	}
5286 	return (thresh);
5287 }
5288 
5289 static uint32_t
5290 rack_grab_rtt(struct tcpcb *tp, struct tcp_rack *rack)
5291 {
5292 	/*
5293 	 * We want the rack_rtt which is the
5294 	 * last rtt we measured. However if that
5295 	 * does not exist we fallback to the srtt (which
5296 	 * we probably will never do) and then as a last
5297 	 * resort we use RACK_INITIAL_RTO if no srtt is
5298 	 * yet set.
5299 	 */
5300 	if (rack->rc_rack_rtt)
5301 		return (rack->rc_rack_rtt);
5302 	else if (tp->t_srtt == 0)
5303 		return (RACK_INITIAL_RTO);
5304 	return (tp->t_srtt);
5305 }
5306 
5307 static struct rack_sendmap *
5308 rack_check_recovery_mode(struct tcpcb *tp, uint32_t tsused)
5309 {
5310 	/*
5311 	 * Check to see that we don't need to fall into recovery. We will
5312 	 * need to do so if our oldest transmit is past the time we should
5313 	 * have had an ack.
5314 	 */
5315 	struct tcp_rack *rack;
5316 	struct rack_sendmap *rsm;
5317 	int32_t idx;
5318 	uint32_t srtt, thresh;
5319 
5320 	rack = (struct tcp_rack *)tp->t_fb_ptr;
5321 	if (RB_EMPTY(&rack->r_ctl.rc_mtree)) {
5322 		return (NULL);
5323 	}
5324 	rsm = TAILQ_FIRST(&rack->r_ctl.rc_tmap);
5325 	if (rsm == NULL)
5326 		return (NULL);
5327 
5328 	if (rsm->r_flags & RACK_ACKED) {
5329 		rsm = rack_find_lowest_rsm(rack);
5330 		if (rsm == NULL)
5331 			return (NULL);
5332 	}
5333 	idx = rsm->r_rtr_cnt - 1;
5334 	srtt = rack_grab_rtt(tp, rack);
5335 	thresh = rack_calc_thresh_rack(rack, srtt, tsused);
5336 	if (TSTMP_LT(tsused, ((uint32_t)rsm->r_tim_lastsent[idx]))) {
5337 		return (NULL);
5338 	}
5339 	if ((tsused - ((uint32_t)rsm->r_tim_lastsent[idx])) < thresh) {
5340 		return (NULL);
5341 	}
5342 	/* Ok if we reach here we are over-due and this guy can be sent */
5343 	if (IN_RECOVERY(tp->t_flags) == 0) {
5344 		/*
5345 		 * For the one that enters us into recovery record undo
5346 		 * info.
5347 		 */
5348 		rack->r_ctl.rc_rsm_start = rsm->r_start;
5349 		rack->r_ctl.rc_cwnd_at = tp->snd_cwnd;
5350 		rack->r_ctl.rc_ssthresh_at = tp->snd_ssthresh;
5351 	}
5352 	rack_cong_signal(tp, CC_NDUPACK, tp->snd_una);
5353 	return (rsm);
5354 }
5355 
5356 static uint32_t
5357 rack_get_persists_timer_val(struct tcpcb *tp, struct tcp_rack *rack)
5358 {
5359 	int32_t t;
5360 	int32_t tt;
5361 	uint32_t ret_val;
5362 
5363 	t = (tp->t_srtt + (tp->t_rttvar << 2));
5364 	RACK_TCPT_RANGESET(tt, t * tcp_backoff[tp->t_rxtshift],
5365  	    rack_persist_min, rack_persist_max, rack->r_ctl.timer_slop);
5366 	if (tp->t_rxtshift < TCP_MAXRXTSHIFT)
5367 		tp->t_rxtshift++;
5368 	rack->r_ctl.rc_hpts_flags |= PACE_TMR_PERSIT;
5369 	ret_val = (uint32_t)tt;
5370 	return (ret_val);
5371 }
5372 
5373 static uint32_t
5374 rack_timer_start(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cts, int sup_rack)
5375 {
5376 	/*
5377 	 * Start the FR timer, we do this based on getting the first one in
5378 	 * the rc_tmap. Note that if its NULL we must stop the timer. in all
5379 	 * events we need to stop the running timer (if its running) before
5380 	 * starting the new one.
5381 	 */
5382 	uint32_t thresh, exp, to, srtt, time_since_sent, tstmp_touse;
5383 	uint32_t srtt_cur;
5384 	int32_t idx;
5385 	int32_t is_tlp_timer = 0;
5386 	struct rack_sendmap *rsm;
5387 
5388 	if (rack->t_timers_stopped) {
5389 		/* All timers have been stopped none are to run */
5390 		return (0);
5391 	}
5392 	if (rack->rc_in_persist) {
5393 		/* We can't start any timer in persists */
5394 		return (rack_get_persists_timer_val(tp, rack));
5395 	}
5396 	rack->rc_on_min_to = 0;
5397 	if ((tp->t_state < TCPS_ESTABLISHED) ||
5398 	    ((tp->t_flags & TF_SACK_PERMIT) == 0)) {
5399 		goto activate_rxt;
5400 	}
5401 	rsm = TAILQ_FIRST(&rack->r_ctl.rc_tmap);
5402 	if ((rsm == NULL) || sup_rack) {
5403 		/* Nothing on the send map or no rack */
5404 activate_rxt:
5405 		time_since_sent = 0;
5406 		rsm = TAILQ_FIRST(&rack->r_ctl.rc_tmap);
5407 		if (rsm) {
5408 			/*
5409 			 * Should we discount the RTX timer any?
5410 			 *
5411 			 * We want to discount it the smallest amount.
5412 			 * If a timer (Rack/TLP or RXT) has gone off more
5413 			 * recently thats the discount we want to use (now - timer time).
5414 			 * If the retransmit of the oldest packet was more recent then
5415 			 * we want to use that (now - oldest-packet-last_transmit_time).
5416 			 *
5417 			 */
5418 			idx = rsm->r_rtr_cnt - 1;
5419 			if (TSTMP_GEQ(rack->r_ctl.rc_tlp_rxt_last_time, ((uint32_t)rsm->r_tim_lastsent[idx])))
5420 				tstmp_touse = (uint32_t)rack->r_ctl.rc_tlp_rxt_last_time;
5421 			else
5422 				tstmp_touse = (uint32_t)rsm->r_tim_lastsent[idx];
5423 			if (TSTMP_GT(cts, tstmp_touse))
5424 			    time_since_sent = cts - tstmp_touse;
5425 		}
5426 		if (SEQ_LT(tp->snd_una, tp->snd_max) || sbavail(&(tp->t_inpcb->inp_socket->so_snd))) {
5427 			rack->r_ctl.rc_hpts_flags |= PACE_TMR_RXT;
5428 			to = tp->t_rxtcur;
5429 			if (to > time_since_sent)
5430 				to -= time_since_sent;
5431 			else
5432 				to = rack->r_ctl.rc_min_to;
5433 			if (to == 0)
5434 				to = 1;
5435 			/* Special case for KEEPINIT */
5436 			if ((TCPS_HAVEESTABLISHED(tp->t_state) == 0) &&
5437 			    (TP_KEEPINIT(tp) != 0) &&
5438 			    rsm) {
5439 				/*
5440 				 * We have to put a ceiling on the rxt timer
5441 				 * of the keep-init timeout.
5442 				 */
5443 				uint32_t max_time, red;
5444 
5445 				max_time = TICKS_2_USEC(TP_KEEPINIT(tp));
5446 				if (TSTMP_GT(cts, (uint32_t)rsm->r_tim_lastsent[0])) {
5447 					red = (cts - (uint32_t)rsm->r_tim_lastsent[0]);
5448 					if (red < max_time)
5449 						max_time -= red;
5450 					else
5451 						max_time = 1;
5452 				}
5453 				/* Reduce timeout to the keep value if needed */
5454 				if (max_time < to)
5455 					to = max_time;
5456 			}
5457 			return (to);
5458 		}
5459 		return (0);
5460 	}
5461 	if (rsm->r_flags & RACK_ACKED) {
5462 		rsm = rack_find_lowest_rsm(rack);
5463 		if (rsm == NULL) {
5464 			/* No lowest? */
5465 			goto activate_rxt;
5466 		}
5467 	}
5468 	if (rack->sack_attack_disable) {
5469 		/*
5470 		 * We don't want to do
5471 		 * any TLP's if you are an attacker.
5472 		 * Though if you are doing what
5473 		 * is expected you may still have
5474 		 * SACK-PASSED marks.
5475 		 */
5476 		goto activate_rxt;
5477 	}
5478 	/* Convert from ms to usecs */
5479 	if ((rsm->r_flags & RACK_SACK_PASSED) || (rsm->r_dupack >= DUP_ACK_THRESHOLD)) {
5480 		if ((tp->t_flags & TF_SENTFIN) &&
5481 		    ((tp->snd_max - tp->snd_una) == 1) &&
5482 		    (rsm->r_flags & RACK_HAS_FIN)) {
5483 			/*
5484 			 * We don't start a rack timer if all we have is a
5485 			 * FIN outstanding.
5486 			 */
5487 			goto activate_rxt;
5488 		}
5489 		if ((rack->use_rack_rr == 0) &&
5490 		    (IN_FASTRECOVERY(tp->t_flags)) &&
5491 		    (rack->rack_no_prr == 0) &&
5492 		     (rack->r_ctl.rc_prr_sndcnt  < ctf_fixed_maxseg(tp))) {
5493 			/*
5494 			 * We are not cheating, in recovery  and
5495 			 * not enough ack's to yet get our next
5496 			 * retransmission out.
5497 			 *
5498 			 * Note that classified attackers do not
5499 			 * get to use the rack-cheat.
5500 			 */
5501 			goto activate_tlp;
5502 		}
5503 		srtt = rack_grab_rtt(tp, rack);
5504 		thresh = rack_calc_thresh_rack(rack, srtt, cts);
5505 		idx = rsm->r_rtr_cnt - 1;
5506 		exp = ((uint32_t)rsm->r_tim_lastsent[idx]) + thresh;
5507 		if (SEQ_GEQ(exp, cts)) {
5508 			to = exp - cts;
5509 			if (to < rack->r_ctl.rc_min_to) {
5510 				to = rack->r_ctl.rc_min_to;
5511 				if (rack->r_rr_config == 3)
5512 					rack->rc_on_min_to = 1;
5513 			}
5514 		} else {
5515 			to = rack->r_ctl.rc_min_to;
5516 			if (rack->r_rr_config == 3)
5517 				rack->rc_on_min_to = 1;
5518 		}
5519 	} else {
5520 		/* Ok we need to do a TLP not RACK */
5521 activate_tlp:
5522 		if ((rack->rc_tlp_in_progress != 0) &&
5523 		    (rack->r_ctl.rc_tlp_cnt_out >= rack_tlp_limit)) {
5524 			/*
5525 			 * The previous send was a TLP and we have sent
5526 			 * N TLP's without sending new data.
5527 			 */
5528 			goto activate_rxt;
5529 		}
5530 		rsm = TAILQ_LAST_FAST(&rack->r_ctl.rc_tmap, rack_sendmap, r_tnext);
5531 		if (rsm == NULL) {
5532 			/* We found no rsm to TLP with. */
5533 			goto activate_rxt;
5534 		}
5535 		if (rsm->r_flags & RACK_HAS_FIN) {
5536 			/* If its a FIN we dont do TLP */
5537 			rsm = NULL;
5538 			goto activate_rxt;
5539 		}
5540 		idx = rsm->r_rtr_cnt - 1;
5541 		time_since_sent = 0;
5542 		if (TSTMP_GEQ(((uint32_t)rsm->r_tim_lastsent[idx]), rack->r_ctl.rc_tlp_rxt_last_time))
5543 			tstmp_touse = (uint32_t)rsm->r_tim_lastsent[idx];
5544 		else
5545 			tstmp_touse = (uint32_t)rack->r_ctl.rc_tlp_rxt_last_time;
5546 		if (TSTMP_GT(cts, tstmp_touse))
5547 		    time_since_sent = cts - tstmp_touse;
5548 		is_tlp_timer = 1;
5549 		if (tp->t_srtt) {
5550 			if ((rack->rc_srtt_measure_made == 0) &&
5551 			    (tp->t_srtt == 1)) {
5552 				/*
5553 				 * If another stack as run and set srtt to 1,
5554 				 * then the srtt was 0, so lets use the initial.
5555 				 */
5556 				srtt = RACK_INITIAL_RTO;
5557 			} else {
5558 				srtt_cur = tp->t_srtt;
5559 				srtt = srtt_cur;
5560 			}
5561 		} else
5562 			srtt = RACK_INITIAL_RTO;
5563 		/*
5564 		 * If the SRTT is not keeping up and the
5565 		 * rack RTT has spiked we want to use
5566 		 * the last RTT not the smoothed one.
5567 		 */
5568 		if (rack_tlp_use_greater &&
5569 		    tp->t_srtt &&
5570 		    (srtt < rack_grab_rtt(tp, rack))) {
5571 			srtt = rack_grab_rtt(tp, rack);
5572 		}
5573 		thresh = rack_calc_thresh_tlp(tp, rack, rsm, srtt);
5574 		if (thresh > time_since_sent) {
5575 			to = thresh - time_since_sent;
5576 		} else {
5577 			to = rack->r_ctl.rc_min_to;
5578 			rack_log_alt_to_to_cancel(rack,
5579 						  thresh,		/* flex1 */
5580 						  time_since_sent,	/* flex2 */
5581 						  tstmp_touse,		/* flex3 */
5582 						  rack->r_ctl.rc_tlp_rxt_last_time, /* flex4 */
5583 						  (uint32_t)rsm->r_tim_lastsent[idx],
5584 						  srtt,
5585 						  idx, 99);
5586 		}
5587 		if (to < rack_tlp_min) {
5588 			to = rack_tlp_min;
5589 		}
5590 		if (to > TICKS_2_USEC(TCPTV_REXMTMAX)) {
5591 			/*
5592 			 * If the TLP time works out to larger than the max
5593 			 * RTO lets not do TLP.. just RTO.
5594 			 */
5595 			goto activate_rxt;
5596 		}
5597 	}
5598 	if (is_tlp_timer == 0) {
5599 		rack->r_ctl.rc_hpts_flags |= PACE_TMR_RACK;
5600 	} else {
5601 		rack->r_ctl.rc_hpts_flags |= PACE_TMR_TLP;
5602 	}
5603 	if (to == 0)
5604 		to = 1;
5605 	return (to);
5606 }
5607 
5608 static void
5609 rack_enter_persist(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cts)
5610 {
5611 	if (rack->rc_in_persist == 0) {
5612 		if (tp->t_flags & TF_GPUTINPROG) {
5613 			/*
5614 			 * Stop the goodput now, the calling of the
5615 			 * measurement function clears the flag.
5616 			 */
5617 			rack_do_goodput_measurement(tp, rack, tp->snd_una, __LINE__,
5618 						    RACK_QUALITY_PERSIST);
5619 		}
5620 #ifdef NETFLIX_SHARED_CWND
5621 		if (rack->r_ctl.rc_scw) {
5622 			tcp_shared_cwnd_idle(rack->r_ctl.rc_scw, rack->r_ctl.rc_scw_index);
5623 			rack->rack_scwnd_is_idle = 1;
5624 		}
5625 #endif
5626 		rack->r_ctl.rc_went_idle_time = tcp_get_usecs(NULL);
5627 		if (rack->r_ctl.rc_went_idle_time == 0)
5628 			rack->r_ctl.rc_went_idle_time = 1;
5629 		rack_timer_cancel(tp, rack, cts, __LINE__);
5630 		tp->t_rxtshift = 0;
5631 		RACK_TCPT_RANGESET(tp->t_rxtcur, RACK_REXMTVAL(tp),
5632 			      rack_rto_min, rack_rto_max, rack->r_ctl.timer_slop);
5633 		rack->rc_in_persist = 1;
5634 	}
5635 }
5636 
5637 static void
5638 rack_exit_persist(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cts)
5639 {
5640 	if (rack->rc_inp->inp_in_hpts) {
5641 		tcp_hpts_remove(rack->rc_inp, HPTS_REMOVE_OUTPUT);
5642 		rack->r_ctl.rc_hpts_flags = 0;
5643 	}
5644 #ifdef NETFLIX_SHARED_CWND
5645 	if (rack->r_ctl.rc_scw) {
5646 		tcp_shared_cwnd_active(rack->r_ctl.rc_scw, rack->r_ctl.rc_scw_index);
5647 		rack->rack_scwnd_is_idle = 0;
5648 	}
5649 #endif
5650 	if (rack->rc_gp_dyn_mul &&
5651 	    (rack->use_fixed_rate == 0) &&
5652 	    (rack->rc_always_pace)) {
5653 		/*
5654 		 * Do we count this as if a probe-rtt just
5655 		 * finished?
5656 		 */
5657 		uint32_t time_idle, idle_min;
5658 
5659 		time_idle = tcp_get_usecs(NULL) - rack->r_ctl.rc_went_idle_time;
5660 		idle_min = rack_min_probertt_hold;
5661 		if (rack_probertt_gpsrtt_cnt_div) {
5662 			uint64_t extra;
5663 			extra = (uint64_t)rack->r_ctl.rc_gp_srtt *
5664 				(uint64_t)rack_probertt_gpsrtt_cnt_mul;
5665 			extra /= (uint64_t)rack_probertt_gpsrtt_cnt_div;
5666 			idle_min += (uint32_t)extra;
5667 		}
5668 		if (time_idle >= idle_min) {
5669 			/* Yes, we count it as a probe-rtt. */
5670 			uint32_t us_cts;
5671 
5672 			us_cts = tcp_get_usecs(NULL);
5673 			if (rack->in_probe_rtt == 0) {
5674 				rack->r_ctl.rc_lower_rtt_us_cts = us_cts;
5675 				rack->r_ctl.rc_time_probertt_entered = rack->r_ctl.rc_lower_rtt_us_cts;
5676 				rack->r_ctl.rc_time_probertt_starts = rack->r_ctl.rc_lower_rtt_us_cts;
5677 				rack->r_ctl.rc_time_of_last_probertt = rack->r_ctl.rc_lower_rtt_us_cts;
5678 			} else {
5679 				rack_exit_probertt(rack, us_cts);
5680 			}
5681 		}
5682 	}
5683 	rack->rc_in_persist = 0;
5684 	rack->r_ctl.rc_went_idle_time = 0;
5685 	tp->t_rxtshift = 0;
5686 	RACK_TCPT_RANGESET(tp->t_rxtcur, RACK_REXMTVAL(tp),
5687 	   rack_rto_min, rack_rto_max, rack->r_ctl.timer_slop);
5688 	rack->r_ctl.rc_agg_delayed = 0;
5689 	rack->r_early = 0;
5690 	rack->r_late = 0;
5691 	rack->r_ctl.rc_agg_early = 0;
5692 }
5693 
5694 static void
5695 rack_log_hpts_diag(struct tcp_rack *rack, uint32_t cts,
5696 		   struct hpts_diag *diag, struct timeval *tv)
5697 {
5698 	if (rack_verbose_logging && rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
5699 		union tcp_log_stackspecific log;
5700 
5701 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
5702 		log.u_bbr.flex1 = diag->p_nxt_slot;
5703 		log.u_bbr.flex2 = diag->p_cur_slot;
5704 		log.u_bbr.flex3 = diag->slot_req;
5705 		log.u_bbr.flex4 = diag->inp_hptsslot;
5706 		log.u_bbr.flex5 = diag->slot_remaining;
5707 		log.u_bbr.flex6 = diag->need_new_to;
5708 		log.u_bbr.flex7 = diag->p_hpts_active;
5709 		log.u_bbr.flex8 = diag->p_on_min_sleep;
5710 		/* Hijack other fields as needed */
5711 		log.u_bbr.epoch = diag->have_slept;
5712 		log.u_bbr.lt_epoch = diag->yet_to_sleep;
5713 		log.u_bbr.pkts_out = diag->co_ret;
5714 		log.u_bbr.applimited = diag->hpts_sleep_time;
5715 		log.u_bbr.delivered = diag->p_prev_slot;
5716 		log.u_bbr.inflight = diag->p_runningslot;
5717 		log.u_bbr.bw_inuse = diag->wheel_slot;
5718 		log.u_bbr.rttProp = diag->wheel_cts;
5719 		log.u_bbr.timeStamp = cts;
5720 		log.u_bbr.delRate = diag->maxslots;
5721 		log.u_bbr.cur_del_rate = diag->p_curtick;
5722 		log.u_bbr.cur_del_rate <<= 32;
5723 		log.u_bbr.cur_del_rate |= diag->p_lasttick;
5724 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
5725 		    &rack->rc_inp->inp_socket->so_rcv,
5726 		    &rack->rc_inp->inp_socket->so_snd,
5727 		    BBR_LOG_HPTSDIAG, 0,
5728 		    0, &log, false, tv);
5729 	}
5730 
5731 }
5732 
5733 static void
5734 rack_log_wakeup(struct tcpcb *tp, struct tcp_rack *rack, struct sockbuf *sb, uint32_t len, int type)
5735 {
5736 	if (rack_verbose_logging && rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
5737 		union tcp_log_stackspecific log;
5738 		struct timeval tv;
5739 
5740 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
5741 		log.u_bbr.flex1 = sb->sb_flags;
5742 		log.u_bbr.flex2 = len;
5743 		log.u_bbr.flex3 = sb->sb_state;
5744 		log.u_bbr.flex8 = type;
5745 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
5746 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
5747 		    &rack->rc_inp->inp_socket->so_rcv,
5748 		    &rack->rc_inp->inp_socket->so_snd,
5749 		    TCP_LOG_SB_WAKE, 0,
5750 		    len, &log, false, &tv);
5751 	}
5752 }
5753 
5754 static void
5755 rack_start_hpts_timer(struct tcp_rack *rack, struct tcpcb *tp, uint32_t cts,
5756       int32_t slot, uint32_t tot_len_this_send, int sup_rack)
5757 {
5758 	struct hpts_diag diag;
5759 	struct inpcb *inp;
5760 	struct timeval tv;
5761 	uint32_t delayed_ack = 0;
5762 	uint32_t hpts_timeout;
5763 	uint32_t entry_slot = slot;
5764 	uint8_t stopped;
5765 	uint32_t left = 0;
5766 	uint32_t us_cts;
5767 
5768 	inp = tp->t_inpcb;
5769 	if ((tp->t_state == TCPS_CLOSED) ||
5770 	    (tp->t_state == TCPS_LISTEN)) {
5771 		return;
5772 	}
5773 	if (inp->inp_in_hpts) {
5774 		/* Already on the pacer */
5775 		return;
5776 	}
5777 	stopped = rack->rc_tmr_stopped;
5778 	if (stopped && TSTMP_GT(rack->r_ctl.rc_timer_exp, cts)) {
5779 		left = rack->r_ctl.rc_timer_exp - cts;
5780 	}
5781 	rack->r_ctl.rc_timer_exp = 0;
5782 	rack->r_ctl.rc_hpts_flags = 0;
5783 	us_cts = tcp_get_usecs(&tv);
5784 	/* Now early/late accounting */
5785 	rack_log_pacing_delay_calc(rack, entry_slot, slot, 0, 0, 0, 26, __LINE__, NULL, 0);
5786 	if (rack->r_early && (rack->rc_ack_can_sendout_data == 0)) {
5787 		/*
5788 		 * We have a early carry over set,
5789 		 * we can always add more time so we
5790 		 * can always make this compensation.
5791 		 *
5792 		 * Note if ack's are allowed to wake us do not
5793 		 * penalize the next timer for being awoke
5794 		 * by an ack aka the rc_agg_early (non-paced mode).
5795 		 */
5796 		slot += rack->r_ctl.rc_agg_early;
5797 		rack->r_early = 0;
5798 		rack->r_ctl.rc_agg_early = 0;
5799 	}
5800 	if (rack->r_late) {
5801 		/*
5802 		 * This is harder, we can
5803 		 * compensate some but it
5804 		 * really depends on what
5805 		 * the current pacing time is.
5806 		 */
5807 		if (rack->r_ctl.rc_agg_delayed >= slot) {
5808 			/*
5809 			 * We can't compensate for it all.
5810 			 * And we have to have some time
5811 			 * on the clock. We always have a min
5812 			 * 10 slots (10 x 10 i.e. 100 usecs).
5813 			 */
5814 			if (slot <= HPTS_TICKS_PER_SLOT) {
5815 				/* We gain delay */
5816 				rack->r_ctl.rc_agg_delayed += (HPTS_TICKS_PER_SLOT - slot);
5817 				slot = HPTS_TICKS_PER_SLOT;
5818 			} else {
5819 				/* We take off some */
5820 				rack->r_ctl.rc_agg_delayed -= (slot - HPTS_TICKS_PER_SLOT);
5821 				slot = HPTS_TICKS_PER_SLOT;
5822 			}
5823 		} else {
5824 			slot -= rack->r_ctl.rc_agg_delayed;
5825 			rack->r_ctl.rc_agg_delayed = 0;
5826 			/* Make sure we have 100 useconds at minimum */
5827 			if (slot < HPTS_TICKS_PER_SLOT) {
5828 				rack->r_ctl.rc_agg_delayed = HPTS_TICKS_PER_SLOT - slot;
5829 				slot = HPTS_TICKS_PER_SLOT;
5830 			}
5831 			if (rack->r_ctl.rc_agg_delayed == 0)
5832 				rack->r_late = 0;
5833 		}
5834 	}
5835 	if (slot) {
5836 		/* We are pacing too */
5837 		rack->r_ctl.rc_hpts_flags |= PACE_PKT_OUTPUT;
5838 	}
5839 	hpts_timeout = rack_timer_start(tp, rack, cts, sup_rack);
5840 #ifdef NETFLIX_EXP_DETECTION
5841 	if (rack->sack_attack_disable &&
5842 	    (slot < tcp_sad_pacing_interval)) {
5843 		/*
5844 		 * We have a potential attacker on
5845 		 * the line. We have possibly some
5846 		 * (or now) pacing time set. We want to
5847 		 * slow down the processing of sacks by some
5848 		 * amount (if it is an attacker). Set the default
5849 		 * slot for attackers in place (unless the orginal
5850 		 * interval is longer). Its stored in
5851 		 * micro-seconds, so lets convert to msecs.
5852 		 */
5853 		slot = tcp_sad_pacing_interval;
5854 	}
5855 #endif
5856 	if (tp->t_flags & TF_DELACK) {
5857 		delayed_ack = TICKS_2_USEC(tcp_delacktime);
5858 		rack->r_ctl.rc_hpts_flags |= PACE_TMR_DELACK;
5859 	}
5860 	if (delayed_ack && ((hpts_timeout == 0) ||
5861 			    (delayed_ack < hpts_timeout)))
5862 		hpts_timeout = delayed_ack;
5863 	else
5864 		rack->r_ctl.rc_hpts_flags &= ~PACE_TMR_DELACK;
5865 	/*
5866 	 * If no timers are going to run and we will fall off the hptsi
5867 	 * wheel, we resort to a keep-alive timer if its configured.
5868 	 */
5869 	if ((hpts_timeout == 0) &&
5870 	    (slot == 0)) {
5871 		if ((V_tcp_always_keepalive || inp->inp_socket->so_options & SO_KEEPALIVE) &&
5872 		    (tp->t_state <= TCPS_CLOSING)) {
5873 			/*
5874 			 * Ok we have no timer (persists, rack, tlp, rxt  or
5875 			 * del-ack), we don't have segments being paced. So
5876 			 * all that is left is the keepalive timer.
5877 			 */
5878 			if (TCPS_HAVEESTABLISHED(tp->t_state)) {
5879 				/* Get the established keep-alive time */
5880 				hpts_timeout = TICKS_2_USEC(TP_KEEPIDLE(tp));
5881 			} else {
5882 				/*
5883 				 * Get the initial setup keep-alive time,
5884 				 * note that this is probably not going to
5885 				 * happen, since rack will be running a rxt timer
5886 				 * if a SYN of some sort is outstanding. It is
5887 				 * actually handled in rack_timeout_rxt().
5888 				 */
5889 				hpts_timeout = TICKS_2_USEC(TP_KEEPINIT(tp));
5890 			}
5891 			rack->r_ctl.rc_hpts_flags |= PACE_TMR_KEEP;
5892 			if (rack->in_probe_rtt) {
5893 				/*
5894 				 * We want to instead not wake up a long time from
5895 				 * now but to wake up about the time we would
5896 				 * exit probe-rtt and initiate a keep-alive ack.
5897 				 * This will get us out of probe-rtt and update
5898 				 * our min-rtt.
5899 				 */
5900 				hpts_timeout = rack_min_probertt_hold;
5901 			}
5902 		}
5903 	}
5904 	if (left && (stopped & (PACE_TMR_KEEP | PACE_TMR_DELACK)) ==
5905 	    (rack->r_ctl.rc_hpts_flags & PACE_TMR_MASK)) {
5906 		/*
5907 		 * RACK, TLP, persists and RXT timers all are restartable
5908 		 * based on actions input .. i.e we received a packet (ack
5909 		 * or sack) and that changes things (rw, or snd_una etc).
5910 		 * Thus we can restart them with a new value. For
5911 		 * keep-alive, delayed_ack we keep track of what was left
5912 		 * and restart the timer with a smaller value.
5913 		 */
5914 		if (left < hpts_timeout)
5915 			hpts_timeout = left;
5916 	}
5917 	if (hpts_timeout) {
5918 		/*
5919 		 * Hack alert for now we can't time-out over 2,147,483
5920 		 * seconds (a bit more than 596 hours), which is probably ok
5921 		 * :).
5922 		 */
5923 		if (hpts_timeout > 0x7ffffffe)
5924 			hpts_timeout = 0x7ffffffe;
5925 		rack->r_ctl.rc_timer_exp = cts + hpts_timeout;
5926 	}
5927 	rack_log_pacing_delay_calc(rack, entry_slot, slot, hpts_timeout, 0, 0, 27, __LINE__, NULL, 0);
5928 	if ((rack->gp_ready == 0) &&
5929 	    (rack->use_fixed_rate == 0) &&
5930 	    (hpts_timeout < slot) &&
5931 	    (rack->r_ctl.rc_hpts_flags & (PACE_TMR_TLP|PACE_TMR_RXT))) {
5932 		/*
5933 		 * We have no good estimate yet for the
5934 		 * old clunky burst mitigation or the
5935 		 * real pacing. And the tlp or rxt is smaller
5936 		 * than the pacing calculation. Lets not
5937 		 * pace that long since we know the calculation
5938 		 * so far is not accurate.
5939 		 */
5940 		slot = hpts_timeout;
5941 	}
5942 	rack->r_ctl.last_pacing_time = slot;
5943 	/**
5944 	 * Turn off all the flags for queuing by default. The
5945 	 * flags have important meanings to what happens when
5946 	 * LRO interacts with the transport. Most likely (by default now)
5947 	 * mbuf_queueing and ack compression are on. So the transport
5948 	 * has a couple of flags that control what happens (if those
5949 	 * are not on then these flags won't have any effect since it
5950 	 * won't go through the queuing LRO path).
5951 	 *
5952 	 * INP_MBUF_QUEUE_READY - This flags says that I am busy
5953 	 *                        pacing output, so don't disturb. But
5954 	 *                        it also means LRO can wake me if there
5955 	 *                        is a SACK arrival.
5956 	 *
5957 	 * INP_DONT_SACK_QUEUE - This flag is used in conjunction
5958 	 *                       with the above flag (QUEUE_READY) and
5959 	 *                       when present it says don't even wake me
5960 	 *                       if a SACK arrives.
5961 	 *
5962 	 * The idea behind these flags is that if we are pacing we
5963 	 * set the MBUF_QUEUE_READY and only get woken up if
5964 	 * a SACK arrives (which could change things) or if
5965 	 * our pacing timer expires. If, however, we have a rack
5966 	 * timer running, then we don't even want a sack to wake
5967 	 * us since the rack timer has to expire before we can send.
5968 	 *
5969 	 * Other cases should usually have none of the flags set
5970 	 * so LRO can call into us.
5971 	 */
5972 	inp->inp_flags2 &= ~(INP_DONT_SACK_QUEUE|INP_MBUF_QUEUE_READY);
5973 	if (slot) {
5974 		rack->r_ctl.rc_last_output_to = us_cts + slot;
5975 		/*
5976 		 * A pacing timer (slot) is being set, in
5977 		 * such a case we cannot send (we are blocked by
5978 		 * the timer). So lets tell LRO that it should not
5979 		 * wake us unless there is a SACK. Note this only
5980 		 * will be effective if mbuf queueing is on or
5981 		 * compressed acks are being processed.
5982 		 */
5983 		inp->inp_flags2 |= INP_MBUF_QUEUE_READY;
5984 		/*
5985 		 * But wait if we have a Rack timer running
5986 		 * even a SACK should not disturb us (with
5987 		 * the exception of r_rr_config 3).
5988 		 */
5989 		if ((rack->r_ctl.rc_hpts_flags & PACE_TMR_RACK) &&
5990 		    (rack->r_rr_config != 3))
5991 			inp->inp_flags2 |= INP_DONT_SACK_QUEUE;
5992 		if (rack->rc_ack_can_sendout_data) {
5993 			/*
5994 			 * Ahh but wait, this is that special case
5995 			 * where the pacing timer can be disturbed
5996 			 * backout the changes (used for non-paced
5997 			 * burst limiting).
5998 			 */
5999 			inp->inp_flags2 &= ~(INP_DONT_SACK_QUEUE|INP_MBUF_QUEUE_READY);
6000 		}
6001 		if ((rack->use_rack_rr) &&
6002 		    (rack->r_rr_config < 2) &&
6003 		    ((hpts_timeout) && (hpts_timeout < slot))) {
6004 			/*
6005 			 * Arrange for the hpts to kick back in after the
6006 			 * t-o if the t-o does not cause a send.
6007 			 */
6008 			(void)tcp_hpts_insert_diag(tp->t_inpcb, HPTS_USEC_TO_SLOTS(hpts_timeout),
6009 						   __LINE__, &diag);
6010 			rack_log_hpts_diag(rack, us_cts, &diag, &tv);
6011 			rack_log_to_start(rack, cts, hpts_timeout, slot, 0);
6012 		} else {
6013 			(void)tcp_hpts_insert_diag(tp->t_inpcb, HPTS_USEC_TO_SLOTS(slot),
6014 						   __LINE__, &diag);
6015 			rack_log_hpts_diag(rack, us_cts, &diag, &tv);
6016 			rack_log_to_start(rack, cts, hpts_timeout, slot, 1);
6017 		}
6018 	} else if (hpts_timeout) {
6019 		/*
6020 		 * With respect to inp_flags2 here, lets let any new acks wake
6021 		 * us up here. Since we are not pacing (no pacing timer), output
6022 		 * can happen so we should let it. If its a Rack timer, then any inbound
6023 		 * packet probably won't change the sending (we will be blocked)
6024 		 * but it may change the prr stats so letting it in (the set defaults
6025 		 * at the start of this block) are good enough.
6026 		 */
6027 		(void)tcp_hpts_insert_diag(tp->t_inpcb, HPTS_USEC_TO_SLOTS(hpts_timeout),
6028 					   __LINE__, &diag);
6029 		rack_log_hpts_diag(rack, us_cts, &diag, &tv);
6030 		rack_log_to_start(rack, cts, hpts_timeout, slot, 0);
6031 	} else {
6032 		/* No timer starting */
6033 #ifdef INVARIANTS
6034 		if (SEQ_GT(tp->snd_max, tp->snd_una)) {
6035 			panic("tp:%p rack:%p tlts:%d cts:%u slot:%u pto:%u -- no timer started?",
6036 			    tp, rack, tot_len_this_send, cts, slot, hpts_timeout);
6037 		}
6038 #endif
6039 	}
6040 	rack->rc_tmr_stopped = 0;
6041 	if (slot)
6042 		rack_log_type_bbrsnd(rack, tot_len_this_send, slot, us_cts, &tv);
6043 }
6044 
6045 /*
6046  * RACK Timer, here we simply do logging and house keeping.
6047  * the normal rack_output() function will call the
6048  * appropriate thing to check if we need to do a RACK retransmit.
6049  * We return 1, saying don't proceed with rack_output only
6050  * when all timers have been stopped (destroyed PCB?).
6051  */
6052 static int
6053 rack_timeout_rack(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cts)
6054 {
6055 	/*
6056 	 * This timer simply provides an internal trigger to send out data.
6057 	 * The check_recovery_mode call will see if there are needed
6058 	 * retransmissions, if so we will enter fast-recovery. The output
6059 	 * call may or may not do the same thing depending on sysctl
6060 	 * settings.
6061 	 */
6062 	struct rack_sendmap *rsm;
6063 
6064 	if (tp->t_timers->tt_flags & TT_STOPPED) {
6065 		return (1);
6066 	}
6067 	counter_u64_add(rack_to_tot, 1);
6068 	if (rack->r_state && (rack->r_state != tp->t_state))
6069 		rack_set_state(tp, rack);
6070 	rack->rc_on_min_to = 0;
6071 	rsm = rack_check_recovery_mode(tp, cts);
6072 	rack_log_to_event(rack, RACK_TO_FRM_RACK, rsm);
6073 	if (rsm) {
6074 		rack->r_ctl.rc_resend = rsm;
6075 		rack->r_timer_override = 1;
6076 		if (rack->use_rack_rr) {
6077 			/*
6078 			 * Don't accumulate extra pacing delay
6079 			 * we are allowing the rack timer to
6080 			 * over-ride pacing i.e. rrr takes precedence
6081 			 * if the pacing interval is longer than the rrr
6082 			 * time (in other words we get the min pacing
6083 			 * time versus rrr pacing time).
6084 			 */
6085 			rack->r_ctl.rc_hpts_flags &= ~PACE_PKT_OUTPUT;
6086 		}
6087 	}
6088 	rack->r_ctl.rc_hpts_flags &= ~PACE_TMR_RACK;
6089 	if (rsm == NULL) {
6090 		/* restart a timer and return 1 */
6091 		rack_start_hpts_timer(rack, tp, cts,
6092 				      0, 0, 0);
6093 		return (1);
6094 	}
6095 	return (0);
6096 }
6097 
6098 static void
6099 rack_adjust_orig_mlen(struct rack_sendmap *rsm)
6100 {
6101 	if (rsm->m->m_len > rsm->orig_m_len) {
6102 		/*
6103 		 * Mbuf grew, caused by sbcompress, our offset does
6104 		 * not change.
6105 		 */
6106 		rsm->orig_m_len = rsm->m->m_len;
6107 	} else if (rsm->m->m_len < rsm->orig_m_len) {
6108 		/*
6109 		 * Mbuf shrank, trimmed off the top by an ack, our
6110 		 * offset changes.
6111 		 */
6112 		rsm->soff -= (rsm->orig_m_len - rsm->m->m_len);
6113 		rsm->orig_m_len = rsm->m->m_len;
6114 	}
6115 }
6116 
6117 static void
6118 rack_setup_offset_for_rsm(struct rack_sendmap *src_rsm, struct rack_sendmap *rsm)
6119 {
6120 	struct mbuf *m;
6121 	uint32_t soff;
6122 
6123 	if (src_rsm->m && (src_rsm->orig_m_len != src_rsm->m->m_len)) {
6124 		/* Fix up the orig_m_len and possibly the mbuf offset */
6125 		rack_adjust_orig_mlen(src_rsm);
6126 	}
6127 	m = src_rsm->m;
6128 	soff = src_rsm->soff + (src_rsm->r_end - src_rsm->r_start);
6129 	while (soff >= m->m_len) {
6130 		/* Move out past this mbuf */
6131 		soff -= m->m_len;
6132 		m = m->m_next;
6133 		KASSERT((m != NULL),
6134 			("rsm:%p nrsm:%p hit at soff:%u null m",
6135 			 src_rsm, rsm, soff));
6136 	}
6137 	rsm->m = m;
6138 	rsm->soff = soff;
6139 	rsm->orig_m_len = m->m_len;
6140 }
6141 
6142 static __inline void
6143 rack_clone_rsm(struct tcp_rack *rack, struct rack_sendmap *nrsm,
6144 	       struct rack_sendmap *rsm, uint32_t start)
6145 {
6146 	int idx;
6147 
6148 	nrsm->r_start = start;
6149 	nrsm->r_end = rsm->r_end;
6150 	nrsm->r_rtr_cnt = rsm->r_rtr_cnt;
6151 	nrsm->r_flags = rsm->r_flags;
6152 	nrsm->r_dupack = rsm->r_dupack;
6153 	nrsm->r_no_rtt_allowed = rsm->r_no_rtt_allowed;
6154 	nrsm->r_rtr_bytes = 0;
6155 	nrsm->r_fas = rsm->r_fas;
6156 	rsm->r_end = nrsm->r_start;
6157 	nrsm->r_just_ret = rsm->r_just_ret;
6158 	for (idx = 0; idx < nrsm->r_rtr_cnt; idx++) {
6159 		nrsm->r_tim_lastsent[idx] = rsm->r_tim_lastsent[idx];
6160 	}
6161 	/* Now if we have SYN flag we keep it on the left edge */
6162 	if (nrsm->r_flags & RACK_HAS_SYN)
6163 		nrsm->r_flags &= ~RACK_HAS_SYN;
6164 	/* Now if we have a FIN flag we keep it on the right edge */
6165 	if (rsm->r_flags & RACK_HAS_FIN)
6166 		rsm->r_flags &= ~RACK_HAS_FIN;
6167 	/* Push bit must go to the right edge as well */
6168 	if (rsm->r_flags & RACK_HAD_PUSH)
6169 		rsm->r_flags &= ~RACK_HAD_PUSH;
6170 	/* Clone over the state of the hw_tls flag */
6171 	nrsm->r_hw_tls = rsm->r_hw_tls;
6172 	/*
6173 	 * Now we need to find nrsm's new location in the mbuf chain
6174 	 * we basically calculate a new offset, which is soff +
6175 	 * how much is left in original rsm. Then we walk out the mbuf
6176 	 * chain to find the righ postion, it may be the same mbuf
6177 	 * or maybe not.
6178 	 */
6179 	KASSERT(((rsm->m != NULL) ||
6180 		 (rsm->r_flags & (RACK_HAS_SYN|RACK_HAS_FIN))),
6181 		("rsm:%p nrsm:%p rack:%p -- rsm->m is NULL?", rsm, nrsm, rack));
6182 	if (rsm->m)
6183 		rack_setup_offset_for_rsm(rsm, nrsm);
6184 }
6185 
6186 static struct rack_sendmap *
6187 rack_merge_rsm(struct tcp_rack *rack,
6188 	       struct rack_sendmap *l_rsm,
6189 	       struct rack_sendmap *r_rsm)
6190 {
6191 	/*
6192 	 * We are merging two ack'd RSM's,
6193 	 * the l_rsm is on the left (lower seq
6194 	 * values) and the r_rsm is on the right
6195 	 * (higher seq value). The simplest way
6196 	 * to merge these is to move the right
6197 	 * one into the left. I don't think there
6198 	 * is any reason we need to try to find
6199 	 * the oldest (or last oldest retransmitted).
6200 	 */
6201 	struct rack_sendmap *rm;
6202 
6203 	rack_log_map_chg(rack->rc_tp, rack, NULL,
6204 			 l_rsm, r_rsm, MAP_MERGE, r_rsm->r_end, __LINE__);
6205 	l_rsm->r_end = r_rsm->r_end;
6206 	if (l_rsm->r_dupack < r_rsm->r_dupack)
6207 		l_rsm->r_dupack = r_rsm->r_dupack;
6208 	if (r_rsm->r_rtr_bytes)
6209 		l_rsm->r_rtr_bytes += r_rsm->r_rtr_bytes;
6210 	if (r_rsm->r_in_tmap) {
6211 		/* This really should not happen */
6212 		TAILQ_REMOVE(&rack->r_ctl.rc_tmap, r_rsm, r_tnext);
6213 		r_rsm->r_in_tmap = 0;
6214 	}
6215 
6216 	/* Now the flags */
6217 	if (r_rsm->r_flags & RACK_HAS_FIN)
6218 		l_rsm->r_flags |= RACK_HAS_FIN;
6219 	if (r_rsm->r_flags & RACK_TLP)
6220 		l_rsm->r_flags |= RACK_TLP;
6221 	if (r_rsm->r_flags & RACK_RWND_COLLAPSED)
6222 		l_rsm->r_flags |= RACK_RWND_COLLAPSED;
6223 	if ((r_rsm->r_flags & RACK_APP_LIMITED)  &&
6224 	    ((l_rsm->r_flags & RACK_APP_LIMITED) == 0)) {
6225 		/*
6226 		 * If both are app-limited then let the
6227 		 * free lower the count. If right is app
6228 		 * limited and left is not, transfer.
6229 		 */
6230 		l_rsm->r_flags |= RACK_APP_LIMITED;
6231 		r_rsm->r_flags &= ~RACK_APP_LIMITED;
6232 		if (r_rsm == rack->r_ctl.rc_first_appl)
6233 			rack->r_ctl.rc_first_appl = l_rsm;
6234 	}
6235 	rm = RB_REMOVE(rack_rb_tree_head, &rack->r_ctl.rc_mtree, r_rsm);
6236 #ifdef INVARIANTS
6237 	if (rm != r_rsm) {
6238 		panic("removing head in rack:%p rsm:%p rm:%p",
6239 		      rack, r_rsm, rm);
6240 	}
6241 #endif
6242 	if ((r_rsm->r_limit_type == 0) && (l_rsm->r_limit_type != 0)) {
6243 		/* Transfer the split limit to the map we free */
6244 		r_rsm->r_limit_type = l_rsm->r_limit_type;
6245 		l_rsm->r_limit_type = 0;
6246 	}
6247 	rack_free(rack, r_rsm);
6248 	return (l_rsm);
6249 }
6250 
6251 /*
6252  * TLP Timer, here we simply setup what segment we want to
6253  * have the TLP expire on, the normal rack_output() will then
6254  * send it out.
6255  *
6256  * We return 1, saying don't proceed with rack_output only
6257  * when all timers have been stopped (destroyed PCB?).
6258  */
6259 static int
6260 rack_timeout_tlp(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cts, uint8_t *doing_tlp)
6261 {
6262 	/*
6263 	 * Tail Loss Probe.
6264 	 */
6265 	struct rack_sendmap *rsm = NULL;
6266 	struct rack_sendmap *insret;
6267 	struct socket *so;
6268 	uint32_t amm;
6269 	uint32_t out, avail;
6270 	int collapsed_win = 0;
6271 
6272 	if (tp->t_timers->tt_flags & TT_STOPPED) {
6273 		return (1);
6274 	}
6275 	if (TSTMP_LT(cts, rack->r_ctl.rc_timer_exp)) {
6276 		/* Its not time yet */
6277 		return (0);
6278 	}
6279 	if (ctf_progress_timeout_check(tp, true)) {
6280 		rack_log_progress_event(rack, tp, tick, PROGRESS_DROP, __LINE__);
6281 		tcp_set_inp_to_drop(tp->t_inpcb, ETIMEDOUT);
6282 		return (1);
6283 	}
6284 	/*
6285 	 * A TLP timer has expired. We have been idle for 2 rtts. So we now
6286 	 * need to figure out how to force a full MSS segment out.
6287 	 */
6288 	rack_log_to_event(rack, RACK_TO_FRM_TLP, NULL);
6289 	rack->r_ctl.retran_during_recovery = 0;
6290 	rack->r_ctl.dsack_byte_cnt = 0;
6291 	counter_u64_add(rack_tlp_tot, 1);
6292 	if (rack->r_state && (rack->r_state != tp->t_state))
6293 		rack_set_state(tp, rack);
6294 	so = tp->t_inpcb->inp_socket;
6295 	avail = sbavail(&so->so_snd);
6296 	out = tp->snd_max - tp->snd_una;
6297 	if (out > tp->snd_wnd) {
6298 		/* special case, we need a retransmission */
6299 		collapsed_win = 1;
6300 		goto need_retran;
6301 	}
6302 	if (rack->r_ctl.dsack_persist && (rack->r_ctl.rc_tlp_cnt_out >= 1)) {
6303 		rack->r_ctl.dsack_persist--;
6304 		if (rack->r_ctl.num_dsack && (rack->r_ctl.dsack_persist == 0)) {
6305 			rack->r_ctl.num_dsack = 0;
6306 		}
6307 		rack_log_dsack_event(rack, 1, __LINE__, 0, 0);
6308 	}
6309 	if ((tp->t_flags & TF_GPUTINPROG) &&
6310 	    (rack->r_ctl.rc_tlp_cnt_out == 1)) {
6311 		/*
6312 		 * If this is the second in a row
6313 		 * TLP and we are doing a measurement
6314 		 * its time to abandon the measurement.
6315 		 * Something is likely broken on
6316 		 * the clients network and measuring a
6317 		 * broken network does us no good.
6318 		 */
6319 		tp->t_flags &= ~TF_GPUTINPROG;
6320 		rack_log_pacing_delay_calc(rack, (tp->gput_ack - tp->gput_seq) /*flex2*/,
6321 					   rack->r_ctl.rc_gp_srtt /*flex1*/,
6322 					   tp->gput_seq,
6323 					   0, 0, 18, __LINE__, NULL, 0);
6324 	}
6325 	/*
6326 	 * Check our send oldest always settings, and if
6327 	 * there is an oldest to send jump to the need_retran.
6328 	 */
6329 	if (rack_always_send_oldest && (TAILQ_EMPTY(&rack->r_ctl.rc_tmap) == 0))
6330 		goto need_retran;
6331 
6332 	if (avail > out) {
6333 		/* New data is available */
6334 		amm = avail - out;
6335 		if (amm > ctf_fixed_maxseg(tp)) {
6336 			amm = ctf_fixed_maxseg(tp);
6337 			if ((amm + out) > tp->snd_wnd) {
6338 				/* We are rwnd limited */
6339 				goto need_retran;
6340 			}
6341 		} else if (amm < ctf_fixed_maxseg(tp)) {
6342 			/* not enough to fill a MTU */
6343 			goto need_retran;
6344 		}
6345 		if (IN_FASTRECOVERY(tp->t_flags)) {
6346 			/* Unlikely */
6347 			if (rack->rack_no_prr == 0) {
6348 				if (out + amm <= tp->snd_wnd) {
6349 					rack->r_ctl.rc_prr_sndcnt = amm;
6350 					rack->r_ctl.rc_tlp_new_data = amm;
6351 					rack_log_to_prr(rack, 4, 0);
6352 				}
6353 			} else
6354 				goto need_retran;
6355 		} else {
6356 			/* Set the send-new override */
6357 			if (out + amm <= tp->snd_wnd)
6358 				rack->r_ctl.rc_tlp_new_data = amm;
6359 			else
6360 				goto need_retran;
6361 		}
6362 		rack->r_ctl.rc_tlpsend = NULL;
6363 		counter_u64_add(rack_tlp_newdata, 1);
6364 		goto send;
6365 	}
6366 need_retran:
6367 	/*
6368 	 * Ok we need to arrange the last un-acked segment to be re-sent, or
6369 	 * optionally the first un-acked segment.
6370 	 */
6371 	if (collapsed_win == 0) {
6372 		if (rack_always_send_oldest)
6373 			rsm = TAILQ_FIRST(&rack->r_ctl.rc_tmap);
6374 		else {
6375 			rsm = RB_MAX(rack_rb_tree_head, &rack->r_ctl.rc_mtree);
6376 			if (rsm && (rsm->r_flags & (RACK_ACKED | RACK_HAS_FIN))) {
6377 				rsm = rack_find_high_nonack(rack, rsm);
6378 			}
6379 		}
6380 		if (rsm == NULL) {
6381 			counter_u64_add(rack_tlp_does_nada, 1);
6382 #ifdef TCP_BLACKBOX
6383 			tcp_log_dump_tp_logbuf(tp, "nada counter trips", M_NOWAIT, true);
6384 #endif
6385 			goto out;
6386 		}
6387 	} else {
6388 		/*
6389 		 * We must find the last segment
6390 		 * that was acceptable by the client.
6391 		 */
6392 		RB_FOREACH_REVERSE(rsm, rack_rb_tree_head, &rack->r_ctl.rc_mtree) {
6393 			if ((rsm->r_flags & RACK_RWND_COLLAPSED) == 0) {
6394 				/* Found one */
6395 				break;
6396 			}
6397 		}
6398 		if (rsm == NULL) {
6399 			/* None? if so send the first */
6400 			rsm = RB_MIN(rack_rb_tree_head, &rack->r_ctl.rc_mtree);
6401 			if (rsm == NULL) {
6402 				counter_u64_add(rack_tlp_does_nada, 1);
6403 #ifdef TCP_BLACKBOX
6404 				tcp_log_dump_tp_logbuf(tp, "nada counter trips", M_NOWAIT, true);
6405 #endif
6406 				goto out;
6407 			}
6408 		}
6409 	}
6410 	if ((rsm->r_end - rsm->r_start) > ctf_fixed_maxseg(tp)) {
6411 		/*
6412 		 * We need to split this the last segment in two.
6413 		 */
6414 		struct rack_sendmap *nrsm;
6415 
6416 		nrsm = rack_alloc_full_limit(rack);
6417 		if (nrsm == NULL) {
6418 			/*
6419 			 * No memory to split, we will just exit and punt
6420 			 * off to the RXT timer.
6421 			 */
6422 			counter_u64_add(rack_tlp_does_nada, 1);
6423 			goto out;
6424 		}
6425 		rack_clone_rsm(rack, nrsm, rsm,
6426 			       (rsm->r_end - ctf_fixed_maxseg(tp)));
6427 		rack_log_map_chg(tp, rack, NULL, rsm, nrsm, MAP_SPLIT, 0, __LINE__);
6428 		insret = RB_INSERT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, nrsm);
6429 #ifdef INVARIANTS
6430 		if (insret != NULL) {
6431 			panic("Insert in rb tree of %p fails ret:%p rack:%p rsm:%p",
6432 			      nrsm, insret, rack, rsm);
6433 		}
6434 #endif
6435 		if (rsm->r_in_tmap) {
6436 			TAILQ_INSERT_AFTER(&rack->r_ctl.rc_tmap, rsm, nrsm, r_tnext);
6437 			nrsm->r_in_tmap = 1;
6438 		}
6439 		rsm = nrsm;
6440 	}
6441 	rack->r_ctl.rc_tlpsend = rsm;
6442 send:
6443 	/* Make sure output path knows we are doing a TLP */
6444 	*doing_tlp = 1;
6445 	rack->r_timer_override = 1;
6446 	rack->r_ctl.rc_hpts_flags &= ~PACE_TMR_TLP;
6447 	return (0);
6448 out:
6449 	rack->r_ctl.rc_hpts_flags &= ~PACE_TMR_TLP;
6450 	return (0);
6451 }
6452 
6453 /*
6454  * Delayed ack Timer, here we simply need to setup the
6455  * ACK_NOW flag and remove the DELACK flag. From there
6456  * the output routine will send the ack out.
6457  *
6458  * We only return 1, saying don't proceed, if all timers
6459  * are stopped (destroyed PCB?).
6460  */
6461 static int
6462 rack_timeout_delack(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cts)
6463 {
6464 	if (tp->t_timers->tt_flags & TT_STOPPED) {
6465 		return (1);
6466 	}
6467 	rack_log_to_event(rack, RACK_TO_FRM_DELACK, NULL);
6468 	tp->t_flags &= ~TF_DELACK;
6469 	tp->t_flags |= TF_ACKNOW;
6470 	KMOD_TCPSTAT_INC(tcps_delack);
6471 	rack->r_ctl.rc_hpts_flags &= ~PACE_TMR_DELACK;
6472 	return (0);
6473 }
6474 
6475 /*
6476  * Persists timer, here we simply send the
6477  * same thing as a keepalive will.
6478  * the one byte send.
6479  *
6480  * We only return 1, saying don't proceed, if all timers
6481  * are stopped (destroyed PCB?).
6482  */
6483 static int
6484 rack_timeout_persist(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cts)
6485 {
6486 	struct tcptemp *t_template;
6487 	struct inpcb *inp;
6488 	int32_t retval = 1;
6489 
6490 	inp = tp->t_inpcb;
6491 
6492 	if (tp->t_timers->tt_flags & TT_STOPPED) {
6493 		return (1);
6494 	}
6495 	if (rack->rc_in_persist == 0)
6496 		return (0);
6497 	if (ctf_progress_timeout_check(tp, false)) {
6498 		tcp_log_end_status(tp, TCP_EI_STATUS_PERSIST_MAX);
6499 		rack_log_progress_event(rack, tp, tick, PROGRESS_DROP, __LINE__);
6500 		tcp_set_inp_to_drop(inp, ETIMEDOUT);
6501 		return (1);
6502 	}
6503 	KASSERT(inp != NULL, ("%s: tp %p tp->t_inpcb == NULL", __func__, tp));
6504 	/*
6505 	 * Persistence timer into zero window. Force a byte to be output, if
6506 	 * possible.
6507 	 */
6508 	KMOD_TCPSTAT_INC(tcps_persisttimeo);
6509 	/*
6510 	 * Hack: if the peer is dead/unreachable, we do not time out if the
6511 	 * window is closed.  After a full backoff, drop the connection if
6512 	 * the idle time (no responses to probes) reaches the maximum
6513 	 * backoff that we would use if retransmitting.
6514 	 */
6515 	if (tp->t_rxtshift == TCP_MAXRXTSHIFT &&
6516 	    (ticks - tp->t_rcvtime >= tcp_maxpersistidle ||
6517 	     TICKS_2_USEC(ticks - tp->t_rcvtime) >= RACK_REXMTVAL(tp) * tcp_totbackoff)) {
6518 		KMOD_TCPSTAT_INC(tcps_persistdrop);
6519 		retval = 1;
6520 		tcp_log_end_status(tp, TCP_EI_STATUS_PERSIST_MAX);
6521 		tcp_set_inp_to_drop(rack->rc_inp, ETIMEDOUT);
6522 		goto out;
6523 	}
6524 	if ((sbavail(&rack->rc_inp->inp_socket->so_snd) == 0) &&
6525 	    tp->snd_una == tp->snd_max)
6526 		rack_exit_persist(tp, rack, cts);
6527 	rack->r_ctl.rc_hpts_flags &= ~PACE_TMR_PERSIT;
6528 	/*
6529 	 * If the user has closed the socket then drop a persisting
6530 	 * connection after a much reduced timeout.
6531 	 */
6532 	if (tp->t_state > TCPS_CLOSE_WAIT &&
6533 	    (ticks - tp->t_rcvtime) >= TCPTV_PERSMAX) {
6534 		retval = 1;
6535 		KMOD_TCPSTAT_INC(tcps_persistdrop);
6536 		tcp_log_end_status(tp, TCP_EI_STATUS_PERSIST_MAX);
6537 		tcp_set_inp_to_drop(rack->rc_inp, ETIMEDOUT);
6538 		goto out;
6539 	}
6540 	t_template = tcpip_maketemplate(rack->rc_inp);
6541 	if (t_template) {
6542 		/* only set it if we were answered */
6543 		if (rack->forced_ack == 0) {
6544 			rack->forced_ack = 1;
6545 			rack->r_ctl.forced_ack_ts = tcp_get_usecs(NULL);
6546 		}
6547 		tcp_respond(tp, t_template->tt_ipgen,
6548 			    &t_template->tt_t, (struct mbuf *)NULL,
6549 			    tp->rcv_nxt, tp->snd_una - 1, 0);
6550 		/* This sends an ack */
6551 		if (tp->t_flags & TF_DELACK)
6552 			tp->t_flags &= ~TF_DELACK;
6553 		free(t_template, M_TEMP);
6554 	}
6555 	if (tp->t_rxtshift < TCP_MAXRXTSHIFT)
6556 		tp->t_rxtshift++;
6557 out:
6558 	rack_log_to_event(rack, RACK_TO_FRM_PERSIST, NULL);
6559 	rack_start_hpts_timer(rack, tp, cts,
6560 			      0, 0, 0);
6561 	return (retval);
6562 }
6563 
6564 /*
6565  * If a keepalive goes off, we had no other timers
6566  * happening. We always return 1 here since this
6567  * routine either drops the connection or sends
6568  * out a segment with respond.
6569  */
6570 static int
6571 rack_timeout_keepalive(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cts)
6572 {
6573 	struct tcptemp *t_template;
6574 	struct inpcb *inp;
6575 
6576 	if (tp->t_timers->tt_flags & TT_STOPPED) {
6577 		return (1);
6578 	}
6579 	rack->r_ctl.rc_hpts_flags &= ~PACE_TMR_KEEP;
6580 	inp = tp->t_inpcb;
6581 	rack_log_to_event(rack, RACK_TO_FRM_KEEP, NULL);
6582 	/*
6583 	 * Keep-alive timer went off; send something or drop connection if
6584 	 * idle for too long.
6585 	 */
6586 	KMOD_TCPSTAT_INC(tcps_keeptimeo);
6587 	if (tp->t_state < TCPS_ESTABLISHED)
6588 		goto dropit;
6589 	if ((V_tcp_always_keepalive || inp->inp_socket->so_options & SO_KEEPALIVE) &&
6590 	    tp->t_state <= TCPS_CLOSING) {
6591 		if (ticks - tp->t_rcvtime >= TP_KEEPIDLE(tp) + TP_MAXIDLE(tp))
6592 			goto dropit;
6593 		/*
6594 		 * Send a packet designed to force a response if the peer is
6595 		 * up and reachable: either an ACK if the connection is
6596 		 * still alive, or an RST if the peer has closed the
6597 		 * connection due to timeout or reboot. Using sequence
6598 		 * number tp->snd_una-1 causes the transmitted zero-length
6599 		 * segment to lie outside the receive window; by the
6600 		 * protocol spec, this requires the correspondent TCP to
6601 		 * respond.
6602 		 */
6603 		KMOD_TCPSTAT_INC(tcps_keepprobe);
6604 		t_template = tcpip_maketemplate(inp);
6605 		if (t_template) {
6606 			if (rack->forced_ack == 0) {
6607 				rack->forced_ack = 1;
6608 				rack->r_ctl.forced_ack_ts = tcp_get_usecs(NULL);
6609 			}
6610 			tcp_respond(tp, t_template->tt_ipgen,
6611 			    &t_template->tt_t, (struct mbuf *)NULL,
6612 			    tp->rcv_nxt, tp->snd_una - 1, 0);
6613 			free(t_template, M_TEMP);
6614 		}
6615 	}
6616 	rack_start_hpts_timer(rack, tp, cts, 0, 0, 0);
6617 	return (1);
6618 dropit:
6619 	KMOD_TCPSTAT_INC(tcps_keepdrops);
6620 	tcp_log_end_status(tp, TCP_EI_STATUS_KEEP_MAX);
6621 	tcp_set_inp_to_drop(rack->rc_inp, ETIMEDOUT);
6622 	return (1);
6623 }
6624 
6625 /*
6626  * Retransmit helper function, clear up all the ack
6627  * flags and take care of important book keeping.
6628  */
6629 static void
6630 rack_remxt_tmr(struct tcpcb *tp)
6631 {
6632 	/*
6633 	 * The retransmit timer went off, all sack'd blocks must be
6634 	 * un-acked.
6635 	 */
6636 	struct rack_sendmap *rsm, *trsm = NULL;
6637 	struct tcp_rack *rack;
6638 
6639 	rack = (struct tcp_rack *)tp->t_fb_ptr;
6640 	rack_timer_cancel(tp, rack, tcp_get_usecs(NULL), __LINE__);
6641 	rack_log_to_event(rack, RACK_TO_FRM_TMR, NULL);
6642 	if (rack->r_state && (rack->r_state != tp->t_state))
6643 		rack_set_state(tp, rack);
6644 	/*
6645 	 * Ideally we would like to be able to
6646 	 * mark SACK-PASS on anything not acked here.
6647 	 *
6648 	 * However, if we do that we would burst out
6649 	 * all that data 1ms apart. This would be unwise,
6650 	 * so for now we will just let the normal rxt timer
6651 	 * and tlp timer take care of it.
6652 	 *
6653 	 * Also we really need to stick them back in sequence
6654 	 * order. This way we send in the proper order and any
6655 	 * sacks that come floating in will "re-ack" the data.
6656 	 * To do this we zap the tmap with an INIT and then
6657 	 * walk through and place every rsm in the RB tree
6658 	 * back in its seq ordered place.
6659 	 */
6660 	TAILQ_INIT(&rack->r_ctl.rc_tmap);
6661 	RB_FOREACH(rsm, rack_rb_tree_head, &rack->r_ctl.rc_mtree) {
6662 		rsm->r_dupack = 0;
6663 		rack_log_retran_reason(rack, rsm, __LINE__, 0, 2);
6664 		/* We must re-add it back to the tlist */
6665 		if (trsm == NULL) {
6666 			TAILQ_INSERT_HEAD(&rack->r_ctl.rc_tmap, rsm, r_tnext);
6667 		} else {
6668 			TAILQ_INSERT_AFTER(&rack->r_ctl.rc_tmap, trsm, rsm, r_tnext);
6669 		}
6670 		rsm->r_in_tmap = 1;
6671 		trsm = rsm;
6672 		if (rsm->r_flags & RACK_ACKED)
6673 			rsm->r_flags |= RACK_WAS_ACKED;
6674 		rsm->r_flags &= ~(RACK_ACKED | RACK_SACK_PASSED | RACK_WAS_SACKPASS);
6675 	}
6676 	/* Clear the count (we just un-acked them) */
6677 	rack->r_ctl.rc_last_timeout_snduna = tp->snd_una;
6678 	rack->r_ctl.rc_sacked = 0;
6679 	rack->r_ctl.rc_sacklast = NULL;
6680 	rack->r_ctl.rc_agg_delayed = 0;
6681 	rack->r_early = 0;
6682 	rack->r_ctl.rc_agg_early = 0;
6683 	rack->r_late = 0;
6684 	/* Clear the tlp rtx mark */
6685 	rack->r_ctl.rc_resend = RB_MIN(rack_rb_tree_head, &rack->r_ctl.rc_mtree);
6686 	if (rack->r_ctl.rc_resend != NULL)
6687 		rack->r_ctl.rc_resend->r_flags |= RACK_TO_REXT;
6688 	rack->r_ctl.rc_prr_sndcnt = 0;
6689 	rack_log_to_prr(rack, 6, 0);
6690 	rack->r_timer_override = 1;
6691 	if ((((tp->t_flags & TF_SACK_PERMIT) == 0)
6692 #ifdef NETFLIX_EXP_DETECTION
6693 	    || (rack->sack_attack_disable != 0)
6694 #endif
6695 		    ) && ((tp->t_flags & TF_SENTFIN) == 0)) {
6696 		/*
6697 		 * For non-sack customers new data
6698 		 * needs to go out as retransmits until
6699 		 * we retransmit up to snd_max.
6700 		 */
6701 		rack->r_must_retran = 1;
6702 		rack->r_ctl.rc_out_at_rto = ctf_flight_size(rack->rc_tp,
6703 						rack->r_ctl.rc_sacked);
6704 	}
6705 	rack->r_ctl.rc_snd_max_at_rto = tp->snd_max;
6706 }
6707 
6708 static void
6709 rack_convert_rtts(struct tcpcb *tp)
6710 {
6711 	if (tp->t_srtt > 1) {
6712 		uint32_t val, frac;
6713 
6714 		val = tp->t_srtt >> TCP_RTT_SHIFT;
6715 		frac = tp->t_srtt & 0x1f;
6716 		tp->t_srtt = TICKS_2_USEC(val);
6717 		/*
6718 		 * frac is the fractional part of the srtt (if any)
6719 		 * but its in ticks and every bit represents
6720 		 * 1/32nd of a hz.
6721 		 */
6722 		if (frac) {
6723 			if (hz == 1000) {
6724 				frac = (((uint64_t)frac * (uint64_t)HPTS_USEC_IN_MSEC) / (uint64_t)TCP_RTT_SCALE);
6725 			} else {
6726 				frac = (((uint64_t)frac * (uint64_t)HPTS_USEC_IN_SEC) / ((uint64_t)(hz) * (uint64_t)TCP_RTT_SCALE));
6727 			}
6728 			tp->t_srtt += frac;
6729 		}
6730 	}
6731 	if (tp->t_rttvar) {
6732 		uint32_t val, frac;
6733 
6734 		val = tp->t_rttvar >> TCP_RTTVAR_SHIFT;
6735 		frac = tp->t_rttvar & 0x1f;
6736 		tp->t_rttvar = TICKS_2_USEC(val);
6737 		/*
6738 		 * frac is the fractional part of the srtt (if any)
6739 		 * but its in ticks and every bit represents
6740 		 * 1/32nd of a hz.
6741 		 */
6742 		if (frac) {
6743 			if (hz == 1000) {
6744 				frac = (((uint64_t)frac * (uint64_t)HPTS_USEC_IN_MSEC) / (uint64_t)TCP_RTT_SCALE);
6745 			} else {
6746 				frac = (((uint64_t)frac * (uint64_t)HPTS_USEC_IN_SEC) / ((uint64_t)(hz) * (uint64_t)TCP_RTT_SCALE));
6747 			}
6748 			tp->t_rttvar += frac;
6749 		}
6750 	}
6751 	tp->t_rxtcur = RACK_REXMTVAL(tp);
6752 	if (TCPS_HAVEESTABLISHED(tp->t_state)) {
6753 		tp->t_rxtcur += TICKS_2_USEC(tcp_rexmit_slop);
6754 	}
6755 	if (tp->t_rxtcur > rack_rto_max) {
6756 		tp->t_rxtcur = rack_rto_max;
6757 	}
6758 }
6759 
6760 static void
6761 rack_cc_conn_init(struct tcpcb *tp)
6762 {
6763 	struct tcp_rack *rack;
6764 	uint32_t srtt;
6765 
6766 	rack = (struct tcp_rack *)tp->t_fb_ptr;
6767 	srtt = tp->t_srtt;
6768 	cc_conn_init(tp);
6769 	/*
6770 	 * Now convert to rack's internal format,
6771 	 * if required.
6772 	 */
6773 	if ((srtt == 0) && (tp->t_srtt != 0))
6774 		rack_convert_rtts(tp);
6775 	/*
6776 	 * We want a chance to stay in slowstart as
6777 	 * we create a connection. TCP spec says that
6778 	 * initially ssthresh is infinite. For our
6779 	 * purposes that is the snd_wnd.
6780 	 */
6781 	if (tp->snd_ssthresh < tp->snd_wnd) {
6782 		tp->snd_ssthresh = tp->snd_wnd;
6783 	}
6784 	/*
6785 	 * We also want to assure a IW worth of
6786 	 * data can get inflight.
6787 	 */
6788 	if (rc_init_window(rack) < tp->snd_cwnd)
6789 		tp->snd_cwnd = rc_init_window(rack);
6790 }
6791 
6792 /*
6793  * Re-transmit timeout! If we drop the PCB we will return 1, otherwise
6794  * we will setup to retransmit the lowest seq number outstanding.
6795  */
6796 static int
6797 rack_timeout_rxt(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cts)
6798 {
6799 	int32_t rexmt;
6800 	struct inpcb *inp;
6801 	int32_t retval = 0;
6802 	bool isipv6;
6803 
6804 	inp = tp->t_inpcb;
6805 	if (tp->t_timers->tt_flags & TT_STOPPED) {
6806 		return (1);
6807 	}
6808 	if ((tp->t_flags & TF_GPUTINPROG) &&
6809 	    (tp->t_rxtshift)) {
6810 		/*
6811 		 * We have had a second timeout
6812 		 * measurements on successive rxt's are not profitable.
6813 		 * It is unlikely to be of any use (the network is
6814 		 * broken or the client went away).
6815 		 */
6816 		tp->t_flags &= ~TF_GPUTINPROG;
6817 		rack_log_pacing_delay_calc(rack, (tp->gput_ack - tp->gput_seq) /*flex2*/,
6818 					   rack->r_ctl.rc_gp_srtt /*flex1*/,
6819 					   tp->gput_seq,
6820 					   0, 0, 18, __LINE__, NULL, 0);
6821 	}
6822 	if (ctf_progress_timeout_check(tp, false)) {
6823 		tcp_log_end_status(tp, TCP_EI_STATUS_RETRAN);
6824 		rack_log_progress_event(rack, tp, tick, PROGRESS_DROP, __LINE__);
6825 		tcp_set_inp_to_drop(inp, ETIMEDOUT);
6826 		return (1);
6827 	}
6828 	rack->r_ctl.rc_hpts_flags &= ~PACE_TMR_RXT;
6829 	rack->r_ctl.retran_during_recovery = 0;
6830 	rack->r_ctl.dsack_byte_cnt = 0;
6831 	if (IN_FASTRECOVERY(tp->t_flags))
6832 		tp->t_flags |= TF_WASFRECOVERY;
6833 	else
6834 		tp->t_flags &= ~TF_WASFRECOVERY;
6835 	if (IN_CONGRECOVERY(tp->t_flags))
6836 		tp->t_flags |= TF_WASCRECOVERY;
6837 	else
6838 		tp->t_flags &= ~TF_WASCRECOVERY;
6839 	if (TCPS_HAVEESTABLISHED(tp->t_state) &&
6840 	    (tp->snd_una == tp->snd_max)) {
6841 		/* Nothing outstanding .. nothing to do */
6842 		return (0);
6843 	}
6844 	if (rack->r_ctl.dsack_persist) {
6845 		rack->r_ctl.dsack_persist--;
6846 		if (rack->r_ctl.num_dsack && (rack->r_ctl.dsack_persist == 0)) {
6847 			rack->r_ctl.num_dsack = 0;
6848 		}
6849 		rack_log_dsack_event(rack, 1, __LINE__, 0, 0);
6850 	}
6851 	/*
6852 	 * Rack can only run one timer  at a time, so we cannot
6853 	 * run a KEEPINIT (gating SYN sending) and a retransmit
6854 	 * timer for the SYN. So if we are in a front state and
6855 	 * have a KEEPINIT timer we need to check the first transmit
6856 	 * against now to see if we have exceeded the KEEPINIT time
6857 	 * (if one is set).
6858 	 */
6859 	if ((TCPS_HAVEESTABLISHED(tp->t_state) == 0) &&
6860 	    (TP_KEEPINIT(tp) != 0)) {
6861 		struct rack_sendmap *rsm;
6862 
6863 		rsm = RB_MIN(rack_rb_tree_head, &rack->r_ctl.rc_mtree);
6864 		if (rsm) {
6865 			/* Ok we have something outstanding to test keepinit with */
6866 			if ((TSTMP_GT(cts, (uint32_t)rsm->r_tim_lastsent[0])) &&
6867 			    ((cts - (uint32_t)rsm->r_tim_lastsent[0]) >= TICKS_2_USEC(TP_KEEPINIT(tp)))) {
6868 				/* We have exceeded the KEEPINIT time */
6869 				tcp_log_end_status(tp, TCP_EI_STATUS_KEEP_MAX);
6870 				goto drop_it;
6871 			}
6872 		}
6873 	}
6874 	/*
6875 	 * Retransmission timer went off.  Message has not been acked within
6876 	 * retransmit interval.  Back off to a longer retransmit interval
6877 	 * and retransmit one segment.
6878 	 */
6879 	rack_remxt_tmr(tp);
6880 	if ((rack->r_ctl.rc_resend == NULL) ||
6881 	    ((rack->r_ctl.rc_resend->r_flags & RACK_RWND_COLLAPSED) == 0)) {
6882 		/*
6883 		 * If the rwnd collapsed on
6884 		 * the one we are retransmitting
6885 		 * it does not count against the
6886 		 * rxt count.
6887 		 */
6888 		tp->t_rxtshift++;
6889 	}
6890 	if (tp->t_rxtshift > TCP_MAXRXTSHIFT) {
6891 		tcp_log_end_status(tp, TCP_EI_STATUS_RETRAN);
6892 drop_it:
6893 		tp->t_rxtshift = TCP_MAXRXTSHIFT;
6894 		KMOD_TCPSTAT_INC(tcps_timeoutdrop);
6895 		retval = 1;
6896 		tcp_set_inp_to_drop(rack->rc_inp,
6897 		    (tp->t_softerror ? (uint16_t) tp->t_softerror : ETIMEDOUT));
6898 		goto out;
6899 	}
6900 	if (tp->t_state == TCPS_SYN_SENT) {
6901 		/*
6902 		 * If the SYN was retransmitted, indicate CWND to be limited
6903 		 * to 1 segment in cc_conn_init().
6904 		 */
6905 		tp->snd_cwnd = 1;
6906 	} else if (tp->t_rxtshift == 1) {
6907 		/*
6908 		 * first retransmit; record ssthresh and cwnd so they can be
6909 		 * recovered if this turns out to be a "bad" retransmit. A
6910 		 * retransmit is considered "bad" if an ACK for this segment
6911 		 * is received within RTT/2 interval; the assumption here is
6912 		 * that the ACK was already in flight.  See "On Estimating
6913 		 * End-to-End Network Path Properties" by Allman and Paxson
6914 		 * for more details.
6915 		 */
6916 		tp->snd_cwnd_prev = tp->snd_cwnd;
6917 		tp->snd_ssthresh_prev = tp->snd_ssthresh;
6918 		tp->snd_recover_prev = tp->snd_recover;
6919 		tp->t_badrxtwin = ticks + (USEC_2_TICKS(tp->t_srtt)/2);
6920 		tp->t_flags |= TF_PREVVALID;
6921 	} else if ((tp->t_flags & TF_RCVD_TSTMP) == 0)
6922 		tp->t_flags &= ~TF_PREVVALID;
6923 	KMOD_TCPSTAT_INC(tcps_rexmttimeo);
6924 	if ((tp->t_state == TCPS_SYN_SENT) ||
6925 	    (tp->t_state == TCPS_SYN_RECEIVED))
6926 		rexmt = RACK_INITIAL_RTO * tcp_backoff[tp->t_rxtshift];
6927 	else
6928 		rexmt = max(rack_rto_min, (tp->t_srtt + (tp->t_rttvar << 2))) * tcp_backoff[tp->t_rxtshift];
6929 
6930 	RACK_TCPT_RANGESET(tp->t_rxtcur, rexmt,
6931 	   max(rack_rto_min, rexmt), rack_rto_max, rack->r_ctl.timer_slop);
6932 	/*
6933 	 * We enter the path for PLMTUD if connection is established or, if
6934 	 * connection is FIN_WAIT_1 status, reason for the last is that if
6935 	 * amount of data we send is very small, we could send it in couple
6936 	 * of packets and process straight to FIN. In that case we won't
6937 	 * catch ESTABLISHED state.
6938 	 */
6939 #ifdef INET6
6940 	isipv6 = (tp->t_inpcb->inp_vflag & INP_IPV6) ? true : false;
6941 #else
6942 	isipv6 = false;
6943 #endif
6944 	if (((V_tcp_pmtud_blackhole_detect == 1) ||
6945 	    (V_tcp_pmtud_blackhole_detect == 2 && !isipv6) ||
6946 	    (V_tcp_pmtud_blackhole_detect == 3 && isipv6)) &&
6947 	    ((tp->t_state == TCPS_ESTABLISHED) ||
6948 	    (tp->t_state == TCPS_FIN_WAIT_1))) {
6949 		/*
6950 		 * Idea here is that at each stage of mtu probe (usually,
6951 		 * 1448 -> 1188 -> 524) should be given 2 chances to recover
6952 		 * before further clamping down. 'tp->t_rxtshift % 2 == 0'
6953 		 * should take care of that.
6954 		 */
6955 		if (((tp->t_flags2 & (TF2_PLPMTU_PMTUD | TF2_PLPMTU_MAXSEGSNT)) ==
6956 		    (TF2_PLPMTU_PMTUD | TF2_PLPMTU_MAXSEGSNT)) &&
6957 		    (tp->t_rxtshift >= 2 && tp->t_rxtshift < 6 &&
6958 		    tp->t_rxtshift % 2 == 0)) {
6959 			/*
6960 			 * Enter Path MTU Black-hole Detection mechanism: -
6961 			 * Disable Path MTU Discovery (IP "DF" bit). -
6962 			 * Reduce MTU to lower value than what we negotiated
6963 			 * with peer.
6964 			 */
6965 			if ((tp->t_flags2 & TF2_PLPMTU_BLACKHOLE) == 0) {
6966 				/* Record that we may have found a black hole. */
6967 				tp->t_flags2 |= TF2_PLPMTU_BLACKHOLE;
6968 				/* Keep track of previous MSS. */
6969 				tp->t_pmtud_saved_maxseg = tp->t_maxseg;
6970 			}
6971 
6972 			/*
6973 			 * Reduce the MSS to blackhole value or to the
6974 			 * default in an attempt to retransmit.
6975 			 */
6976 #ifdef INET6
6977 			if (isipv6 &&
6978 			    tp->t_maxseg > V_tcp_v6pmtud_blackhole_mss) {
6979 				/* Use the sysctl tuneable blackhole MSS. */
6980 				tp->t_maxseg = V_tcp_v6pmtud_blackhole_mss;
6981 				KMOD_TCPSTAT_INC(tcps_pmtud_blackhole_activated);
6982 			} else if (isipv6) {
6983 				/* Use the default MSS. */
6984 				tp->t_maxseg = V_tcp_v6mssdflt;
6985 				/*
6986 				 * Disable Path MTU Discovery when we switch
6987 				 * to minmss.
6988 				 */
6989 				tp->t_flags2 &= ~TF2_PLPMTU_PMTUD;
6990 				KMOD_TCPSTAT_INC(tcps_pmtud_blackhole_activated_min_mss);
6991 			}
6992 #endif
6993 #if defined(INET6) && defined(INET)
6994 			else
6995 #endif
6996 #ifdef INET
6997 			if (tp->t_maxseg > V_tcp_pmtud_blackhole_mss) {
6998 				/* Use the sysctl tuneable blackhole MSS. */
6999 				tp->t_maxseg = V_tcp_pmtud_blackhole_mss;
7000 				KMOD_TCPSTAT_INC(tcps_pmtud_blackhole_activated);
7001 			} else {
7002 				/* Use the default MSS. */
7003 				tp->t_maxseg = V_tcp_mssdflt;
7004 				/*
7005 				 * Disable Path MTU Discovery when we switch
7006 				 * to minmss.
7007 				 */
7008 				tp->t_flags2 &= ~TF2_PLPMTU_PMTUD;
7009 				KMOD_TCPSTAT_INC(tcps_pmtud_blackhole_activated_min_mss);
7010 			}
7011 #endif
7012 		} else {
7013 			/*
7014 			 * If further retransmissions are still unsuccessful
7015 			 * with a lowered MTU, maybe this isn't a blackhole
7016 			 * and we restore the previous MSS and blackhole
7017 			 * detection flags. The limit '6' is determined by
7018 			 * giving each probe stage (1448, 1188, 524) 2
7019 			 * chances to recover.
7020 			 */
7021 			if ((tp->t_flags2 & TF2_PLPMTU_BLACKHOLE) &&
7022 			    (tp->t_rxtshift >= 6)) {
7023 				tp->t_flags2 |= TF2_PLPMTU_PMTUD;
7024 				tp->t_flags2 &= ~TF2_PLPMTU_BLACKHOLE;
7025 				tp->t_maxseg = tp->t_pmtud_saved_maxseg;
7026 				KMOD_TCPSTAT_INC(tcps_pmtud_blackhole_failed);
7027 			}
7028 		}
7029 	}
7030 	/*
7031 	 * Disable RFC1323 and SACK if we haven't got any response to
7032 	 * our third SYN to work-around some broken terminal servers
7033 	 * (most of which have hopefully been retired) that have bad VJ
7034 	 * header compression code which trashes TCP segments containing
7035 	 * unknown-to-them TCP options.
7036 	 */
7037 	if (tcp_rexmit_drop_options && (tp->t_state == TCPS_SYN_SENT) &&
7038 	    (tp->t_rxtshift == 3))
7039 		tp->t_flags &= ~(TF_REQ_SCALE|TF_REQ_TSTMP|TF_SACK_PERMIT);
7040 	/*
7041 	 * If we backed off this far, our srtt estimate is probably bogus.
7042 	 * Clobber it so we'll take the next rtt measurement as our srtt;
7043 	 * move the current srtt into rttvar to keep the current retransmit
7044 	 * times until then.
7045 	 */
7046 	if (tp->t_rxtshift > TCP_MAXRXTSHIFT / 4) {
7047 #ifdef INET6
7048 		if ((tp->t_inpcb->inp_vflag & INP_IPV6) != 0)
7049 			in6_losing(tp->t_inpcb);
7050 		else
7051 #endif
7052 			in_losing(tp->t_inpcb);
7053 		tp->t_rttvar += tp->t_srtt;
7054 		tp->t_srtt = 0;
7055 	}
7056 	sack_filter_clear(&rack->r_ctl.rack_sf, tp->snd_una);
7057 	tp->snd_recover = tp->snd_max;
7058 	tp->t_flags |= TF_ACKNOW;
7059 	tp->t_rtttime = 0;
7060 	rack_cong_signal(tp, CC_RTO, tp->snd_una);
7061 out:
7062 	return (retval);
7063 }
7064 
7065 static int
7066 rack_process_timers(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cts, uint8_t hpts_calling, uint8_t *doing_tlp)
7067 {
7068 	int32_t ret = 0;
7069 	int32_t timers = (rack->r_ctl.rc_hpts_flags & PACE_TMR_MASK);
7070 
7071 	if ((tp->t_state >= TCPS_FIN_WAIT_1) &&
7072 	    (tp->t_flags & TF_GPUTINPROG)) {
7073 		/*
7074 		 * We have a goodput in progress
7075 		 * and we have entered a late state.
7076 		 * Do we have enough data in the sb
7077 		 * to handle the GPUT request?
7078 		 */
7079 		uint32_t bytes;
7080 
7081 		bytes = tp->gput_ack - tp->gput_seq;
7082 		if (SEQ_GT(tp->gput_seq, tp->snd_una))
7083 			bytes += tp->gput_seq - tp->snd_una;
7084 		if (bytes > sbavail(&tp->t_inpcb->inp_socket->so_snd)) {
7085 			/*
7086 			 * There are not enough bytes in the socket
7087 			 * buffer that have been sent to cover this
7088 			 * measurement. Cancel it.
7089 			 */
7090 			rack_log_pacing_delay_calc(rack, (tp->gput_ack - tp->gput_seq) /*flex2*/,
7091 						   rack->r_ctl.rc_gp_srtt /*flex1*/,
7092 						   tp->gput_seq,
7093 						   0, 0, 18, __LINE__, NULL, 0);
7094 			tp->t_flags &= ~TF_GPUTINPROG;
7095 		}
7096 	}
7097 	if (timers == 0) {
7098 		return (0);
7099 	}
7100 	if (tp->t_state == TCPS_LISTEN) {
7101 		/* no timers on listen sockets */
7102 		if (rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT)
7103 			return (0);
7104 		return (1);
7105 	}
7106 	if ((timers & PACE_TMR_RACK) &&
7107 	    rack->rc_on_min_to) {
7108 		/*
7109 		 * For the rack timer when we
7110 		 * are on a min-timeout (which means rrr_conf = 3)
7111 		 * we don't want to check the timer. It may
7112 		 * be going off for a pace and thats ok we
7113 		 * want to send the retransmit (if its ready).
7114 		 *
7115 		 * If its on a normal rack timer (non-min) then
7116 		 * we will check if its expired.
7117 		 */
7118 		goto skip_time_check;
7119 	}
7120 	if (TSTMP_LT(cts, rack->r_ctl.rc_timer_exp)) {
7121 		uint32_t left;
7122 
7123 		if (rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT) {
7124 			ret = -1;
7125 			rack_log_to_processing(rack, cts, ret, 0);
7126 			return (0);
7127 		}
7128 		if (hpts_calling == 0) {
7129 			/*
7130 			 * A user send or queued mbuf (sack) has called us? We
7131 			 * return 0 and let the pacing guards
7132 			 * deal with it if they should or
7133 			 * should not cause a send.
7134 			 */
7135 			ret = -2;
7136 			rack_log_to_processing(rack, cts, ret, 0);
7137 			return (0);
7138 		}
7139 		/*
7140 		 * Ok our timer went off early and we are not paced false
7141 		 * alarm, go back to sleep.
7142 		 */
7143 		ret = -3;
7144 		left = rack->r_ctl.rc_timer_exp - cts;
7145 		tcp_hpts_insert(tp->t_inpcb, HPTS_MS_TO_SLOTS(left));
7146 		rack_log_to_processing(rack, cts, ret, left);
7147 		return (1);
7148 	}
7149 skip_time_check:
7150 	rack->rc_tmr_stopped = 0;
7151 	rack->r_ctl.rc_hpts_flags &= ~PACE_TMR_MASK;
7152 	if (timers & PACE_TMR_DELACK) {
7153 		ret = rack_timeout_delack(tp, rack, cts);
7154 	} else if (timers & PACE_TMR_RACK) {
7155 		rack->r_ctl.rc_tlp_rxt_last_time = cts;
7156 		rack->r_fast_output = 0;
7157 		ret = rack_timeout_rack(tp, rack, cts);
7158 	} else if (timers & PACE_TMR_TLP) {
7159 		rack->r_ctl.rc_tlp_rxt_last_time = cts;
7160 		ret = rack_timeout_tlp(tp, rack, cts, doing_tlp);
7161 	} else if (timers & PACE_TMR_RXT) {
7162 		rack->r_ctl.rc_tlp_rxt_last_time = cts;
7163 		rack->r_fast_output = 0;
7164 		ret = rack_timeout_rxt(tp, rack, cts);
7165 	} else if (timers & PACE_TMR_PERSIT) {
7166 		ret = rack_timeout_persist(tp, rack, cts);
7167 	} else if (timers & PACE_TMR_KEEP) {
7168 		ret = rack_timeout_keepalive(tp, rack, cts);
7169 	}
7170 	rack_log_to_processing(rack, cts, ret, timers);
7171 	return (ret);
7172 }
7173 
7174 static void
7175 rack_timer_cancel(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cts, int line)
7176 {
7177 	struct timeval tv;
7178 	uint32_t us_cts, flags_on_entry;
7179 	uint8_t hpts_removed = 0;
7180 
7181 	flags_on_entry = rack->r_ctl.rc_hpts_flags;
7182 	us_cts = tcp_get_usecs(&tv);
7183 	if ((rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT) &&
7184 	    ((TSTMP_GEQ(us_cts, rack->r_ctl.rc_last_output_to)) ||
7185 	     ((tp->snd_max - tp->snd_una) == 0))) {
7186 		tcp_hpts_remove(rack->rc_inp, HPTS_REMOVE_OUTPUT);
7187 		hpts_removed = 1;
7188 		/* If we were not delayed cancel out the flag. */
7189 		if ((tp->snd_max - tp->snd_una) == 0)
7190 			rack->r_ctl.rc_hpts_flags &= ~PACE_PKT_OUTPUT;
7191 		rack_log_to_cancel(rack, hpts_removed, line, us_cts, &tv, flags_on_entry);
7192 	}
7193 	if (rack->r_ctl.rc_hpts_flags & PACE_TMR_MASK) {
7194 		rack->rc_tmr_stopped = rack->r_ctl.rc_hpts_flags & PACE_TMR_MASK;
7195 		if (rack->rc_inp->inp_in_hpts &&
7196 		    ((rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT) == 0)) {
7197 			/*
7198 			 * Canceling timer's when we have no output being
7199 			 * paced. We also must remove ourselves from the
7200 			 * hpts.
7201 			 */
7202 			tcp_hpts_remove(rack->rc_inp, HPTS_REMOVE_OUTPUT);
7203 			hpts_removed = 1;
7204 		}
7205 		rack->r_ctl.rc_hpts_flags &= ~(PACE_TMR_MASK);
7206 	}
7207 	if (hpts_removed == 0)
7208 		rack_log_to_cancel(rack, hpts_removed, line, us_cts, &tv, flags_on_entry);
7209 }
7210 
7211 static void
7212 rack_timer_stop(struct tcpcb *tp, uint32_t timer_type)
7213 {
7214 	return;
7215 }
7216 
7217 static int
7218 rack_stopall(struct tcpcb *tp)
7219 {
7220 	struct tcp_rack *rack;
7221 	rack = (struct tcp_rack *)tp->t_fb_ptr;
7222 	rack->t_timers_stopped = 1;
7223 	return (0);
7224 }
7225 
7226 static void
7227 rack_timer_activate(struct tcpcb *tp, uint32_t timer_type, uint32_t delta)
7228 {
7229 	return;
7230 }
7231 
7232 static int
7233 rack_timer_active(struct tcpcb *tp, uint32_t timer_type)
7234 {
7235 	return (0);
7236 }
7237 
7238 static void
7239 rack_stop_all_timers(struct tcpcb *tp)
7240 {
7241 	struct tcp_rack *rack;
7242 
7243 	/*
7244 	 * Assure no timers are running.
7245 	 */
7246 	if (tcp_timer_active(tp, TT_PERSIST)) {
7247 		/* We enter in persists, set the flag appropriately */
7248 		rack = (struct tcp_rack *)tp->t_fb_ptr;
7249 		rack->rc_in_persist = 1;
7250 	}
7251 	tcp_timer_suspend(tp, TT_PERSIST);
7252 	tcp_timer_suspend(tp, TT_REXMT);
7253 	tcp_timer_suspend(tp, TT_KEEP);
7254 	tcp_timer_suspend(tp, TT_DELACK);
7255 }
7256 
7257 static void
7258 rack_update_rsm(struct tcpcb *tp, struct tcp_rack *rack,
7259     struct rack_sendmap *rsm, uint64_t ts, uint16_t add_flag)
7260 {
7261 	int32_t idx;
7262 	uint16_t stripped_flags;
7263 
7264 	rsm->r_rtr_cnt++;
7265 	rack_log_retran_reason(rack, rsm, __LINE__, 0, 2);
7266 	rsm->r_dupack = 0;
7267 	if (rsm->r_rtr_cnt > RACK_NUM_OF_RETRANS) {
7268 		rsm->r_rtr_cnt = RACK_NUM_OF_RETRANS;
7269 		rsm->r_flags |= RACK_OVERMAX;
7270 	}
7271 	if ((rsm->r_rtr_cnt > 1) && ((rsm->r_flags & RACK_TLP) == 0)) {
7272 		rack->r_ctl.rc_holes_rxt += (rsm->r_end - rsm->r_start);
7273 		rsm->r_rtr_bytes += (rsm->r_end - rsm->r_start);
7274 	}
7275 	idx = rsm->r_rtr_cnt - 1;
7276 	rsm->r_tim_lastsent[idx] = ts;
7277 	/*
7278 	 * Here we don't add in the len of send, since its already
7279 	 * in snduna <->snd_max.
7280 	 */
7281 	rsm->r_fas = ctf_flight_size(rack->rc_tp,
7282 				     rack->r_ctl.rc_sacked);
7283 	stripped_flags = rsm->r_flags & ~(RACK_SENT_SP|RACK_SENT_FP);
7284 	if (rsm->r_flags & RACK_ACKED) {
7285 		/* Problably MTU discovery messing with us */
7286 		rsm->r_flags &= ~RACK_ACKED;
7287 		rack->r_ctl.rc_sacked -= (rsm->r_end - rsm->r_start);
7288 	}
7289 	if (rsm->r_in_tmap) {
7290 		TAILQ_REMOVE(&rack->r_ctl.rc_tmap, rsm, r_tnext);
7291 		rsm->r_in_tmap = 0;
7292 	}
7293 	TAILQ_INSERT_TAIL(&rack->r_ctl.rc_tmap, rsm, r_tnext);
7294 	rsm->r_in_tmap = 1;
7295 	if (rsm->r_flags & RACK_SACK_PASSED) {
7296 		/* We have retransmitted due to the SACK pass */
7297 		rsm->r_flags &= ~RACK_SACK_PASSED;
7298 		rsm->r_flags |= RACK_WAS_SACKPASS;
7299 	}
7300 }
7301 
7302 static uint32_t
7303 rack_update_entry(struct tcpcb *tp, struct tcp_rack *rack,
7304     struct rack_sendmap *rsm, uint64_t ts, int32_t *lenp, uint16_t add_flag)
7305 {
7306 	/*
7307 	 * We (re-)transmitted starting at rsm->r_start for some length
7308 	 * (possibly less than r_end.
7309 	 */
7310 	struct rack_sendmap *nrsm, *insret;
7311 	uint32_t c_end;
7312 	int32_t len;
7313 
7314 	len = *lenp;
7315 	c_end = rsm->r_start + len;
7316 	if (SEQ_GEQ(c_end, rsm->r_end)) {
7317 		/*
7318 		 * We retransmitted the whole piece or more than the whole
7319 		 * slopping into the next rsm.
7320 		 */
7321 		rack_update_rsm(tp, rack, rsm, ts, add_flag);
7322 		if (c_end == rsm->r_end) {
7323 			*lenp = 0;
7324 			return (0);
7325 		} else {
7326 			int32_t act_len;
7327 
7328 			/* Hangs over the end return whats left */
7329 			act_len = rsm->r_end - rsm->r_start;
7330 			*lenp = (len - act_len);
7331 			return (rsm->r_end);
7332 		}
7333 		/* We don't get out of this block. */
7334 	}
7335 	/*
7336 	 * Here we retransmitted less than the whole thing which means we
7337 	 * have to split this into what was transmitted and what was not.
7338 	 */
7339 	nrsm = rack_alloc_full_limit(rack);
7340 	if (nrsm == NULL) {
7341 		/*
7342 		 * We can't get memory, so lets not proceed.
7343 		 */
7344 		*lenp = 0;
7345 		return (0);
7346 	}
7347 	/*
7348 	 * So here we are going to take the original rsm and make it what we
7349 	 * retransmitted. nrsm will be the tail portion we did not
7350 	 * retransmit. For example say the chunk was 1, 11 (10 bytes). And
7351 	 * we retransmitted 5 bytes i.e. 1, 5. The original piece shrinks to
7352 	 * 1, 6 and the new piece will be 6, 11.
7353 	 */
7354 	rack_clone_rsm(rack, nrsm, rsm, c_end);
7355 	nrsm->r_dupack = 0;
7356 	rack_log_retran_reason(rack, nrsm, __LINE__, 0, 2);
7357 	insret = RB_INSERT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, nrsm);
7358 #ifdef INVARIANTS
7359 	if (insret != NULL) {
7360 		panic("Insert in rb tree of %p fails ret:%p rack:%p rsm:%p",
7361 		      nrsm, insret, rack, rsm);
7362 	}
7363 #endif
7364 	if (rsm->r_in_tmap) {
7365 		TAILQ_INSERT_AFTER(&rack->r_ctl.rc_tmap, rsm, nrsm, r_tnext);
7366 		nrsm->r_in_tmap = 1;
7367 	}
7368 	rsm->r_flags &= (~RACK_HAS_FIN);
7369 	rack_update_rsm(tp, rack, rsm, ts, add_flag);
7370 	/* Log a split of rsm into rsm and nrsm */
7371 	rack_log_map_chg(tp, rack, NULL, rsm, nrsm, MAP_SPLIT, 0, __LINE__);
7372 	*lenp = 0;
7373 	return (0);
7374 }
7375 
7376 static void
7377 rack_log_output(struct tcpcb *tp, struct tcpopt *to, int32_t len,
7378 		uint32_t seq_out, uint8_t th_flags, int32_t err, uint64_t cts,
7379 		struct rack_sendmap *hintrsm, uint16_t add_flag, struct mbuf *s_mb, uint32_t s_moff, int hw_tls)
7380 {
7381 	struct tcp_rack *rack;
7382 	struct rack_sendmap *rsm, *nrsm, *insret, fe;
7383 	register uint32_t snd_max, snd_una;
7384 
7385 	/*
7386 	 * Add to the RACK log of packets in flight or retransmitted. If
7387 	 * there is a TS option we will use the TS echoed, if not we will
7388 	 * grab a TS.
7389 	 *
7390 	 * Retransmissions will increment the count and move the ts to its
7391 	 * proper place. Note that if options do not include TS's then we
7392 	 * won't be able to effectively use the ACK for an RTT on a retran.
7393 	 *
7394 	 * Notes about r_start and r_end. Lets consider a send starting at
7395 	 * sequence 1 for 10 bytes. In such an example the r_start would be
7396 	 * 1 (starting sequence) but the r_end would be r_start+len i.e. 11.
7397 	 * This means that r_end is actually the first sequence for the next
7398 	 * slot (11).
7399 	 *
7400 	 */
7401 	/*
7402 	 * If err is set what do we do XXXrrs? should we not add the thing?
7403 	 * -- i.e. return if err != 0 or should we pretend we sent it? --
7404 	 * i.e. proceed with add ** do this for now.
7405 	 */
7406 	INP_WLOCK_ASSERT(tp->t_inpcb);
7407 	if (err)
7408 		/*
7409 		 * We don't log errors -- we could but snd_max does not
7410 		 * advance in this case either.
7411 		 */
7412 		return;
7413 
7414 	if (th_flags & TH_RST) {
7415 		/*
7416 		 * We don't log resets and we return immediately from
7417 		 * sending
7418 		 */
7419 		return;
7420 	}
7421 	rack = (struct tcp_rack *)tp->t_fb_ptr;
7422 	snd_una = tp->snd_una;
7423 	snd_max = tp->snd_max;
7424 	if (th_flags & (TH_SYN | TH_FIN)) {
7425 		/*
7426 		 * The call to rack_log_output is made before bumping
7427 		 * snd_max. This means we can record one extra byte on a SYN
7428 		 * or FIN if seq_out is adding more on and a FIN is present
7429 		 * (and we are not resending).
7430 		 */
7431 		if ((th_flags & TH_SYN) && (seq_out == tp->iss))
7432 			len++;
7433 		if (th_flags & TH_FIN)
7434 			len++;
7435 		if (SEQ_LT(snd_max, tp->snd_nxt)) {
7436 			/*
7437 			 * The add/update as not been done for the FIN/SYN
7438 			 * yet.
7439 			 */
7440 			snd_max = tp->snd_nxt;
7441 		}
7442 	}
7443 	if (SEQ_LEQ((seq_out + len), snd_una)) {
7444 		/* Are sending an old segment to induce an ack (keep-alive)? */
7445 		return;
7446 	}
7447 	if (SEQ_LT(seq_out, snd_una)) {
7448 		/* huh? should we panic? */
7449 		uint32_t end;
7450 
7451 		end = seq_out + len;
7452 		seq_out = snd_una;
7453 		if (SEQ_GEQ(end, seq_out))
7454 			len = end - seq_out;
7455 		else
7456 			len = 0;
7457 	}
7458 	if (len == 0) {
7459 		/* We don't log zero window probes */
7460 		return;
7461 	}
7462 	rack->r_ctl.rc_time_last_sent = cts;
7463 	if (IN_FASTRECOVERY(tp->t_flags)) {
7464 		rack->r_ctl.rc_prr_out += len;
7465 	}
7466 	/* First question is it a retransmission or new? */
7467 	if (seq_out == snd_max) {
7468 		/* Its new */
7469 again:
7470 		rsm = rack_alloc(rack);
7471 		if (rsm == NULL) {
7472 			/*
7473 			 * Hmm out of memory and the tcb got destroyed while
7474 			 * we tried to wait.
7475 			 */
7476 			return;
7477 		}
7478 		if (th_flags & TH_FIN) {
7479 			rsm->r_flags = RACK_HAS_FIN|add_flag;
7480 		} else {
7481 			rsm->r_flags = add_flag;
7482 		}
7483 		if (hw_tls)
7484 			rsm->r_hw_tls = 1;
7485 		rsm->r_tim_lastsent[0] = cts;
7486 		rsm->r_rtr_cnt = 1;
7487 		rsm->r_rtr_bytes = 0;
7488 		if (th_flags & TH_SYN) {
7489 			/* The data space is one beyond snd_una */
7490 			rsm->r_flags |= RACK_HAS_SYN;
7491 		}
7492 		rsm->r_start = seq_out;
7493 		rsm->r_end = rsm->r_start + len;
7494 		rsm->r_dupack = 0;
7495 		/*
7496 		 * save off the mbuf location that
7497 		 * sndmbuf_noadv returned (which is
7498 		 * where we started copying from)..
7499 		 */
7500 		rsm->m = s_mb;
7501 		rsm->soff = s_moff;
7502 		/*
7503 		 * Here we do add in the len of send, since its not yet
7504 		 * reflected in in snduna <->snd_max
7505 		 */
7506 		rsm->r_fas = (ctf_flight_size(rack->rc_tp,
7507 					      rack->r_ctl.rc_sacked) +
7508 			      (rsm->r_end - rsm->r_start));
7509 		/* rsm->m will be NULL if RACK_HAS_SYN or RACK_HAS_FIN is set */
7510 		if (rsm->m) {
7511 			if (rsm->m->m_len <= rsm->soff) {
7512 				/*
7513 				 * XXXrrs Question, will this happen?
7514 				 *
7515 				 * If sbsndptr is set at the correct place
7516 				 * then s_moff should always be somewhere
7517 				 * within rsm->m. But if the sbsndptr was
7518 				 * off then that won't be true. If it occurs
7519 				 * we need to walkout to the correct location.
7520 				 */
7521 				struct mbuf *lm;
7522 
7523 				lm = rsm->m;
7524 				while (lm->m_len <= rsm->soff) {
7525 					rsm->soff -= lm->m_len;
7526 					lm = lm->m_next;
7527 					KASSERT(lm != NULL, ("%s rack:%p lm goes null orig_off:%u origmb:%p rsm->soff:%u",
7528 							     __func__, rack, s_moff, s_mb, rsm->soff));
7529 				}
7530 				rsm->m = lm;
7531 				counter_u64_add(rack_sbsndptr_wrong, 1);
7532 			} else
7533 				counter_u64_add(rack_sbsndptr_right, 1);
7534 			rsm->orig_m_len = rsm->m->m_len;
7535 		} else
7536 			rsm->orig_m_len = 0;
7537 		rack_log_retran_reason(rack, rsm, __LINE__, 0, 2);
7538 		/* Log a new rsm */
7539 		rack_log_map_chg(tp, rack, NULL, rsm, NULL, MAP_NEW, 0, __LINE__);
7540 		insret = RB_INSERT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm);
7541 #ifdef INVARIANTS
7542 		if (insret != NULL) {
7543 			panic("Insert in rb tree of %p fails ret:%p rack:%p rsm:%p",
7544 			      nrsm, insret, rack, rsm);
7545 		}
7546 #endif
7547 		TAILQ_INSERT_TAIL(&rack->r_ctl.rc_tmap, rsm, r_tnext);
7548 		rsm->r_in_tmap = 1;
7549 		/*
7550 		 * Special case detection, is there just a single
7551 		 * packet outstanding when we are not in recovery?
7552 		 *
7553 		 * If this is true mark it so.
7554 		 */
7555 		if ((IN_FASTRECOVERY(tp->t_flags) == 0) &&
7556 		    (ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked) == ctf_fixed_maxseg(tp))) {
7557 			struct rack_sendmap *prsm;
7558 
7559 			prsm = RB_PREV(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm);
7560 			if (prsm)
7561 				prsm->r_one_out_nr = 1;
7562 		}
7563 		return;
7564 	}
7565 	/*
7566 	 * If we reach here its a retransmission and we need to find it.
7567 	 */
7568 	memset(&fe, 0, sizeof(fe));
7569 more:
7570 	if (hintrsm && (hintrsm->r_start == seq_out)) {
7571 		rsm = hintrsm;
7572 		hintrsm = NULL;
7573 	} else {
7574 		/* No hints sorry */
7575 		rsm = NULL;
7576 	}
7577 	if ((rsm) && (rsm->r_start == seq_out)) {
7578 		seq_out = rack_update_entry(tp, rack, rsm, cts, &len, add_flag);
7579 		if (len == 0) {
7580 			return;
7581 		} else {
7582 			goto more;
7583 		}
7584 	}
7585 	/* Ok it was not the last pointer go through it the hard way. */
7586 refind:
7587 	fe.r_start = seq_out;
7588 	rsm = RB_FIND(rack_rb_tree_head, &rack->r_ctl.rc_mtree, &fe);
7589 	if (rsm) {
7590 		if (rsm->r_start == seq_out) {
7591 			seq_out = rack_update_entry(tp, rack, rsm, cts, &len, add_flag);
7592 			if (len == 0) {
7593 				return;
7594 			} else {
7595 				goto refind;
7596 			}
7597 		}
7598 		if (SEQ_GEQ(seq_out, rsm->r_start) && SEQ_LT(seq_out, rsm->r_end)) {
7599 			/* Transmitted within this piece */
7600 			/*
7601 			 * Ok we must split off the front and then let the
7602 			 * update do the rest
7603 			 */
7604 			nrsm = rack_alloc_full_limit(rack);
7605 			if (nrsm == NULL) {
7606 				rack_update_rsm(tp, rack, rsm, cts, add_flag);
7607 				return;
7608 			}
7609 			/*
7610 			 * copy rsm to nrsm and then trim the front of rsm
7611 			 * to not include this part.
7612 			 */
7613 			rack_clone_rsm(rack, nrsm, rsm, seq_out);
7614 			insret = RB_INSERT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, nrsm);
7615 			rack_log_map_chg(tp, rack, NULL, rsm, nrsm, MAP_SPLIT, 0, __LINE__);
7616 #ifdef INVARIANTS
7617 			if (insret != NULL) {
7618 				panic("Insert in rb tree of %p fails ret:%p rack:%p rsm:%p",
7619 				      nrsm, insret, rack, rsm);
7620 			}
7621 #endif
7622 			if (rsm->r_in_tmap) {
7623 				TAILQ_INSERT_AFTER(&rack->r_ctl.rc_tmap, rsm, nrsm, r_tnext);
7624 				nrsm->r_in_tmap = 1;
7625 			}
7626 			rsm->r_flags &= (~RACK_HAS_FIN);
7627 			seq_out = rack_update_entry(tp, rack, nrsm, cts, &len, add_flag);
7628 			if (len == 0) {
7629 				return;
7630 			} else if (len > 0)
7631 				goto refind;
7632 		}
7633 	}
7634 	/*
7635 	 * Hmm not found in map did they retransmit both old and on into the
7636 	 * new?
7637 	 */
7638 	if (seq_out == tp->snd_max) {
7639 		goto again;
7640 	} else if (SEQ_LT(seq_out, tp->snd_max)) {
7641 #ifdef INVARIANTS
7642 		printf("seq_out:%u len:%d snd_una:%u snd_max:%u -- but rsm not found?\n",
7643 		       seq_out, len, tp->snd_una, tp->snd_max);
7644 		printf("Starting Dump of all rack entries\n");
7645 		RB_FOREACH(rsm, rack_rb_tree_head, &rack->r_ctl.rc_mtree) {
7646 			printf("rsm:%p start:%u end:%u\n",
7647 			       rsm, rsm->r_start, rsm->r_end);
7648 		}
7649 		printf("Dump complete\n");
7650 		panic("seq_out not found rack:%p tp:%p",
7651 		      rack, tp);
7652 #endif
7653 	} else {
7654 #ifdef INVARIANTS
7655 		/*
7656 		 * Hmm beyond sndmax? (only if we are using the new rtt-pack
7657 		 * flag)
7658 		 */
7659 		panic("seq_out:%u(%d) is beyond snd_max:%u tp:%p",
7660 		      seq_out, len, tp->snd_max, tp);
7661 #endif
7662 	}
7663 }
7664 
7665 /*
7666  * Record one of the RTT updates from an ack into
7667  * our sample structure.
7668  */
7669 
7670 static void
7671 tcp_rack_xmit_timer(struct tcp_rack *rack, int32_t rtt, uint32_t len, uint32_t us_rtt,
7672 		    int confidence, struct rack_sendmap *rsm, uint16_t rtrcnt)
7673 {
7674 	if ((rack->r_ctl.rack_rs.rs_flags & RACK_RTT_EMPTY) ||
7675 	    (rack->r_ctl.rack_rs.rs_rtt_lowest > rtt)) {
7676 		rack->r_ctl.rack_rs.rs_rtt_lowest = rtt;
7677 	}
7678 	if ((rack->r_ctl.rack_rs.rs_flags & RACK_RTT_EMPTY) ||
7679 	    (rack->r_ctl.rack_rs.rs_rtt_highest < rtt)) {
7680 		rack->r_ctl.rack_rs.rs_rtt_highest = rtt;
7681 	}
7682 	if (rack->rc_tp->t_flags & TF_GPUTINPROG) {
7683 	    if (us_rtt < rack->r_ctl.rc_gp_lowrtt)
7684 		rack->r_ctl.rc_gp_lowrtt = us_rtt;
7685 	    if (rack->rc_tp->snd_wnd > rack->r_ctl.rc_gp_high_rwnd)
7686 		    rack->r_ctl.rc_gp_high_rwnd = rack->rc_tp->snd_wnd;
7687 	}
7688 	if ((confidence == 1) &&
7689 	    ((rsm == NULL) ||
7690 	     (rsm->r_just_ret) ||
7691 	     (rsm->r_one_out_nr &&
7692 	      len < (ctf_fixed_maxseg(rack->rc_tp) * 2)))) {
7693 		/*
7694 		 * If the rsm had a just return
7695 		 * hit it then we can't trust the
7696 		 * rtt measurement for buffer deterimination
7697 		 * Note that a confidence of 2, indicates
7698 		 * SACK'd which overrides the r_just_ret or
7699 		 * the r_one_out_nr. If it was a CUM-ACK and
7700 		 * we had only two outstanding, but get an
7701 		 * ack for only 1. Then that also lowers our
7702 		 * confidence.
7703 		 */
7704 		confidence = 0;
7705 	}
7706 	if ((rack->r_ctl.rack_rs.rs_flags & RACK_RTT_EMPTY) ||
7707 	    (rack->r_ctl.rack_rs.rs_us_rtt > us_rtt)) {
7708 		if (rack->r_ctl.rack_rs.confidence == 0) {
7709 			/*
7710 			 * We take anything with no current confidence
7711 			 * saved.
7712 			 */
7713 			rack->r_ctl.rack_rs.rs_us_rtt = us_rtt;
7714 			rack->r_ctl.rack_rs.confidence = confidence;
7715 			rack->r_ctl.rack_rs.rs_us_rtrcnt = rtrcnt;
7716 		} else if (confidence || rack->r_ctl.rack_rs.confidence) {
7717 			/*
7718 			 * Once we have a confident number,
7719 			 * we can update it with a smaller
7720 			 * value since this confident number
7721 			 * may include the DSACK time until
7722 			 * the next segment (the second one) arrived.
7723 			 */
7724 			rack->r_ctl.rack_rs.rs_us_rtt = us_rtt;
7725 			rack->r_ctl.rack_rs.confidence = confidence;
7726 			rack->r_ctl.rack_rs.rs_us_rtrcnt = rtrcnt;
7727 		}
7728 	}
7729 	rack_log_rtt_upd(rack->rc_tp, rack, us_rtt, len, rsm, confidence);
7730 	rack->r_ctl.rack_rs.rs_flags = RACK_RTT_VALID;
7731 	rack->r_ctl.rack_rs.rs_rtt_tot += rtt;
7732 	rack->r_ctl.rack_rs.rs_rtt_cnt++;
7733 }
7734 
7735 /*
7736  * Collect new round-trip time estimate
7737  * and update averages and current timeout.
7738  */
7739 static void
7740 tcp_rack_xmit_timer_commit(struct tcp_rack *rack, struct tcpcb *tp)
7741 {
7742 	int32_t delta;
7743 	uint32_t o_srtt, o_var;
7744 	int32_t hrtt_up = 0;
7745 	int32_t rtt;
7746 
7747 	if (rack->r_ctl.rack_rs.rs_flags & RACK_RTT_EMPTY)
7748 		/* No valid sample */
7749 		return;
7750 	if (rack->r_ctl.rc_rate_sample_method == USE_RTT_LOW) {
7751 		/* We are to use the lowest RTT seen in a single ack */
7752 		rtt = rack->r_ctl.rack_rs.rs_rtt_lowest;
7753 	} else if (rack->r_ctl.rc_rate_sample_method == USE_RTT_HIGH) {
7754 		/* We are to use the highest RTT seen in a single ack */
7755 		rtt = rack->r_ctl.rack_rs.rs_rtt_highest;
7756 	} else if (rack->r_ctl.rc_rate_sample_method == USE_RTT_AVG) {
7757 		/* We are to use the average RTT seen in a single ack */
7758 		rtt = (int32_t)(rack->r_ctl.rack_rs.rs_rtt_tot /
7759 				(uint64_t)rack->r_ctl.rack_rs.rs_rtt_cnt);
7760 	} else {
7761 #ifdef INVARIANTS
7762 		panic("Unknown rtt variant %d", rack->r_ctl.rc_rate_sample_method);
7763 #endif
7764 		return;
7765 	}
7766 	if (rtt == 0)
7767 		rtt = 1;
7768 	if (rack->rc_gp_rtt_set == 0) {
7769 		/*
7770 		 * With no RTT we have to accept
7771 		 * even one we are not confident of.
7772 		 */
7773 		rack->r_ctl.rc_gp_srtt = rack->r_ctl.rack_rs.rs_us_rtt;
7774 		rack->rc_gp_rtt_set = 1;
7775 	} else if (rack->r_ctl.rack_rs.confidence) {
7776 		/* update the running gp srtt */
7777 		rack->r_ctl.rc_gp_srtt -= (rack->r_ctl.rc_gp_srtt/8);
7778 		rack->r_ctl.rc_gp_srtt += rack->r_ctl.rack_rs.rs_us_rtt / 8;
7779 	}
7780 	if (rack->r_ctl.rack_rs.confidence) {
7781 		/*
7782 		 * record the low and high for highly buffered path computation,
7783 		 * we only do this if we are confident (not a retransmission).
7784 		 */
7785 		if (rack->r_ctl.rc_highest_us_rtt < rack->r_ctl.rack_rs.rs_us_rtt) {
7786 			rack->r_ctl.rc_highest_us_rtt = rack->r_ctl.rack_rs.rs_us_rtt;
7787 			hrtt_up = 1;
7788 		}
7789 		if (rack->rc_highly_buffered == 0) {
7790 			/*
7791 			 * Currently once we declare a path has
7792 			 * highly buffered there is no going
7793 			 * back, which may be a problem...
7794 			 */
7795 			if ((rack->r_ctl.rc_highest_us_rtt / rack->r_ctl.rc_lowest_us_rtt) > rack_hbp_thresh) {
7796 				rack_log_rtt_shrinks(rack, rack->r_ctl.rack_rs.rs_us_rtt,
7797 						     rack->r_ctl.rc_highest_us_rtt,
7798 						     rack->r_ctl.rc_lowest_us_rtt,
7799 						     RACK_RTTS_SEEHBP);
7800 				rack->rc_highly_buffered = 1;
7801 			}
7802 		}
7803 	}
7804 	if ((rack->r_ctl.rack_rs.confidence) ||
7805 	    (rack->r_ctl.rack_rs.rs_us_rtrcnt == 1)) {
7806 		/*
7807 		 * If we are highly confident of it <or> it was
7808 		 * never retransmitted we accept it as the last us_rtt.
7809 		 */
7810 		rack->r_ctl.rc_last_us_rtt = rack->r_ctl.rack_rs.rs_us_rtt;
7811 		/* The lowest rtt can be set if its was not retransmited */
7812 		if (rack->r_ctl.rc_lowest_us_rtt > rack->r_ctl.rack_rs.rs_us_rtt) {
7813 			rack->r_ctl.rc_lowest_us_rtt = rack->r_ctl.rack_rs.rs_us_rtt;
7814 			if (rack->r_ctl.rc_lowest_us_rtt == 0)
7815 				rack->r_ctl.rc_lowest_us_rtt = 1;
7816 		}
7817 	}
7818 	o_srtt = tp->t_srtt;
7819 	o_var = tp->t_rttvar;
7820 	rack = (struct tcp_rack *)tp->t_fb_ptr;
7821 	if (tp->t_srtt != 0) {
7822 		/*
7823 		 * We keep a simple srtt in microseconds, like our rtt
7824 		 * measurement. We don't need to do any tricks with shifting
7825 		 * etc. Instead we just add in 1/8th of the new measurement
7826 		 * and subtract out 1/8 of the old srtt. We do the same with
7827 		 * the variance after finding the absolute value of the
7828 		 * difference between this sample and the current srtt.
7829 		 */
7830 		delta = tp->t_srtt - rtt;
7831 		/* Take off 1/8th of the current sRTT */
7832 		tp->t_srtt -= (tp->t_srtt >> 3);
7833 		/* Add in 1/8th of the new RTT just measured */
7834 		tp->t_srtt += (rtt >> 3);
7835 		if (tp->t_srtt <= 0)
7836 			tp->t_srtt = 1;
7837 		/* Now lets make the absolute value of the variance */
7838 		if (delta < 0)
7839 			delta = -delta;
7840 		/* Subtract out 1/8th */
7841 		tp->t_rttvar -= (tp->t_rttvar >> 3);
7842 		/* Add in 1/8th of the new variance we just saw */
7843 		tp->t_rttvar += (delta >> 3);
7844 		if (tp->t_rttvar <= 0)
7845 			tp->t_rttvar = 1;
7846 		if (tp->t_rttbest > tp->t_srtt + tp->t_rttvar)
7847 			tp->t_rttbest = tp->t_srtt + tp->t_rttvar;
7848 	} else {
7849 		/*
7850 		 * No rtt measurement yet - use the unsmoothed rtt. Set the
7851 		 * variance to half the rtt (so our first retransmit happens
7852 		 * at 3*rtt).
7853 		 */
7854 		tp->t_srtt = rtt;
7855 		tp->t_rttvar = rtt >> 1;
7856 		tp->t_rttbest = tp->t_srtt + tp->t_rttvar;
7857 	}
7858 	rack->rc_srtt_measure_made = 1;
7859 	KMOD_TCPSTAT_INC(tcps_rttupdated);
7860 	tp->t_rttupdated++;
7861 #ifdef STATS
7862 	if (rack_stats_gets_ms_rtt == 0) {
7863 		/* Send in the microsecond rtt used for rxt timeout purposes */
7864 		stats_voi_update_abs_u32(tp->t_stats, VOI_TCP_RTT, imax(0, rtt));
7865 	} else if (rack_stats_gets_ms_rtt == 1) {
7866 		/* Send in the millisecond rtt used for rxt timeout purposes */
7867 		int32_t ms_rtt;
7868 
7869 		/* Round up */
7870 		ms_rtt = (rtt + HPTS_USEC_IN_MSEC - 1) / HPTS_USEC_IN_MSEC;
7871 		stats_voi_update_abs_u32(tp->t_stats, VOI_TCP_RTT, imax(0, ms_rtt));
7872 	} else if (rack_stats_gets_ms_rtt == 2) {
7873 		/* Send in the millisecond rtt has close to the path RTT as we can get  */
7874 		int32_t ms_rtt;
7875 
7876 		/* Round up */
7877 		ms_rtt = (rack->r_ctl.rack_rs.rs_us_rtt + HPTS_USEC_IN_MSEC - 1) / HPTS_USEC_IN_MSEC;
7878 		stats_voi_update_abs_u32(tp->t_stats, VOI_TCP_RTT, imax(0, ms_rtt));
7879 	}  else {
7880 		/* Send in the microsecond rtt has close to the path RTT as we can get  */
7881 		stats_voi_update_abs_u32(tp->t_stats, VOI_TCP_RTT, imax(0, rack->r_ctl.rack_rs.rs_us_rtt));
7882 	}
7883 
7884 #endif
7885 	/*
7886 	 * the retransmit should happen at rtt + 4 * rttvar. Because of the
7887 	 * way we do the smoothing, srtt and rttvar will each average +1/2
7888 	 * tick of bias.  When we compute the retransmit timer, we want 1/2
7889 	 * tick of rounding and 1 extra tick because of +-1/2 tick
7890 	 * uncertainty in the firing of the timer.  The bias will give us
7891 	 * exactly the 1.5 tick we need.  But, because the bias is
7892 	 * statistical, we have to test that we don't drop below the minimum
7893 	 * feasible timer (which is 2 ticks).
7894 	 */
7895 	tp->t_rxtshift = 0;
7896 	RACK_TCPT_RANGESET(tp->t_rxtcur, RACK_REXMTVAL(tp),
7897 		      max(rack_rto_min, rtt + 2), rack_rto_max, rack->r_ctl.timer_slop);
7898 	rack_log_rtt_sample(rack, rtt);
7899 	tp->t_softerror = 0;
7900 }
7901 
7902 
7903 static void
7904 rack_apply_updated_usrtt(struct tcp_rack *rack, uint32_t us_rtt, uint32_t us_cts)
7905 {
7906 	/*
7907 	 * Apply to filter the inbound us-rtt at us_cts.
7908 	 */
7909 	uint32_t old_rtt;
7910 
7911 	old_rtt = get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt);
7912 	apply_filter_min_small(&rack->r_ctl.rc_gp_min_rtt,
7913 			       us_rtt, us_cts);
7914 	if (rack->r_ctl.last_pacing_time &&
7915 	    rack->rc_gp_dyn_mul &&
7916 	    (rack->r_ctl.last_pacing_time > us_rtt))
7917 		rack->pacing_longer_than_rtt = 1;
7918 	else
7919 		rack->pacing_longer_than_rtt = 0;
7920 	if (old_rtt > us_rtt) {
7921 		/* We just hit a new lower rtt time */
7922 		rack_log_rtt_shrinks(rack,  us_cts,  old_rtt,
7923 				     __LINE__, RACK_RTTS_NEWRTT);
7924 		/*
7925 		 * Only count it if its lower than what we saw within our
7926 		 * calculated range.
7927 		 */
7928 		if ((old_rtt - us_rtt) > rack_min_rtt_movement) {
7929 			if (rack_probertt_lower_within &&
7930 			    rack->rc_gp_dyn_mul &&
7931 			    (rack->use_fixed_rate == 0) &&
7932 			    (rack->rc_always_pace)) {
7933 				/*
7934 				 * We are seeing a new lower rtt very close
7935 				 * to the time that we would have entered probe-rtt.
7936 				 * This is probably due to the fact that a peer flow
7937 				 * has entered probe-rtt. Lets go in now too.
7938 				 */
7939 				uint32_t val;
7940 
7941 				val = rack_probertt_lower_within * rack_time_between_probertt;
7942 				val /= 100;
7943 				if ((rack->in_probe_rtt == 0)  &&
7944 				    ((us_cts - rack->r_ctl.rc_lower_rtt_us_cts) >= (rack_time_between_probertt - val)))	{
7945 					rack_enter_probertt(rack, us_cts);
7946 				}
7947 			}
7948 			rack->r_ctl.rc_lower_rtt_us_cts = us_cts;
7949 		}
7950 	}
7951 }
7952 
7953 static int
7954 rack_update_rtt(struct tcpcb *tp, struct tcp_rack *rack,
7955     struct rack_sendmap *rsm, struct tcpopt *to, uint32_t cts, int32_t ack_type, tcp_seq th_ack)
7956 {
7957 	uint32_t us_rtt;
7958 	int32_t i, all;
7959 	uint32_t t, len_acked;
7960 
7961 	if ((rsm->r_flags & RACK_ACKED) ||
7962 	    (rsm->r_flags & RACK_WAS_ACKED))
7963 		/* Already done */
7964 		return (0);
7965 	if (rsm->r_no_rtt_allowed) {
7966 		/* Not allowed */
7967 		return (0);
7968 	}
7969 	if (ack_type == CUM_ACKED) {
7970 		if (SEQ_GT(th_ack, rsm->r_end)) {
7971 			len_acked = rsm->r_end - rsm->r_start;
7972 			all = 1;
7973 		} else {
7974 			len_acked = th_ack - rsm->r_start;
7975 			all = 0;
7976 		}
7977 	} else {
7978 		len_acked = rsm->r_end - rsm->r_start;
7979 		all = 0;
7980 	}
7981 	if (rsm->r_rtr_cnt == 1) {
7982 
7983 		t = cts - (uint32_t)rsm->r_tim_lastsent[(rsm->r_rtr_cnt - 1)];
7984 		if ((int)t <= 0)
7985 			t = 1;
7986 		if (!tp->t_rttlow || tp->t_rttlow > t)
7987 			tp->t_rttlow = t;
7988 		if (!rack->r_ctl.rc_rack_min_rtt ||
7989 		    SEQ_LT(t, rack->r_ctl.rc_rack_min_rtt)) {
7990 			rack->r_ctl.rc_rack_min_rtt = t;
7991 			if (rack->r_ctl.rc_rack_min_rtt == 0) {
7992 				rack->r_ctl.rc_rack_min_rtt = 1;
7993 			}
7994 		}
7995 		if (TSTMP_GT(tcp_tv_to_usectick(&rack->r_ctl.act_rcv_time), rsm->r_tim_lastsent[(rsm->r_rtr_cnt-1)]))
7996 			us_rtt = tcp_tv_to_usectick(&rack->r_ctl.act_rcv_time) - (uint32_t)rsm->r_tim_lastsent[(rsm->r_rtr_cnt-1)];
7997 		else
7998 			us_rtt = tcp_get_usecs(NULL) - (uint32_t)rsm->r_tim_lastsent[(rsm->r_rtr_cnt-1)];
7999 		if (us_rtt == 0)
8000 			us_rtt = 1;
8001 		if (CC_ALGO(tp)->rttsample != NULL) {
8002 			/* Kick the RTT to the CC */
8003 			CC_ALGO(tp)->rttsample(tp->ccv, us_rtt, 1, rsm->r_fas);
8004 		}
8005 		rack_apply_updated_usrtt(rack, us_rtt, tcp_tv_to_usectick(&rack->r_ctl.act_rcv_time));
8006 		if (ack_type == SACKED) {
8007 			rack_log_rtt_sample_calc(rack, t, (uint32_t)rsm->r_tim_lastsent[(rsm->r_rtr_cnt - 1)], cts, 1);
8008 			tcp_rack_xmit_timer(rack, t + 1, len_acked, us_rtt, 2 , rsm, rsm->r_rtr_cnt);
8009 		} else {
8010 			/*
8011 			 * We need to setup what our confidence
8012 			 * is in this ack.
8013 			 *
8014 			 * If the rsm was app limited and it is
8015 			 * less than a mss in length (the end
8016 			 * of the send) then we have a gap. If we
8017 			 * were app limited but say we were sending
8018 			 * multiple MSS's then we are more confident
8019 			 * int it.
8020 			 *
8021 			 * When we are not app-limited then we see if
8022 			 * the rsm is being included in the current
8023 			 * measurement, we tell this by the app_limited_needs_set
8024 			 * flag.
8025 			 *
8026 			 * Note that being cwnd blocked is not applimited
8027 			 * as well as the pacing delay between packets which
8028 			 * are sending only 1 or 2 MSS's also will show up
8029 			 * in the RTT. We probably need to examine this algorithm
8030 			 * a bit more and enhance it to account for the delay
8031 			 * between rsm's. We could do that by saving off the
8032 			 * pacing delay of each rsm (in an rsm) and then
8033 			 * factoring that in somehow though for now I am
8034 			 * not sure how :)
8035 			 */
8036 			int calc_conf = 0;
8037 
8038 			if (rsm->r_flags & RACK_APP_LIMITED) {
8039 				if (all && (len_acked <= ctf_fixed_maxseg(tp)))
8040 					calc_conf = 0;
8041 				else
8042 					calc_conf = 1;
8043 			} else if (rack->app_limited_needs_set == 0) {
8044 				calc_conf = 1;
8045 			} else {
8046 				calc_conf = 0;
8047 			}
8048 			rack_log_rtt_sample_calc(rack, t, (uint32_t)rsm->r_tim_lastsent[(rsm->r_rtr_cnt - 1)], cts, 2);
8049 			tcp_rack_xmit_timer(rack, t + 1, len_acked, us_rtt,
8050 					    calc_conf, rsm, rsm->r_rtr_cnt);
8051 		}
8052 		if ((rsm->r_flags & RACK_TLP) &&
8053 		    (!IN_FASTRECOVERY(tp->t_flags))) {
8054 			/* Segment was a TLP and our retrans matched */
8055 			if (rack->r_ctl.rc_tlp_cwnd_reduce) {
8056 				rack->r_ctl.rc_rsm_start = tp->snd_max;
8057 				rack->r_ctl.rc_cwnd_at = tp->snd_cwnd;
8058 				rack->r_ctl.rc_ssthresh_at = tp->snd_ssthresh;
8059 				rack_cong_signal(tp, CC_NDUPACK, tp->snd_una);
8060 			}
8061 		}
8062 		if (SEQ_LT(rack->r_ctl.rc_rack_tmit_time, (uint32_t)rsm->r_tim_lastsent[(rsm->r_rtr_cnt - 1)])) {
8063 			/* New more recent rack_tmit_time */
8064 			rack->r_ctl.rc_rack_tmit_time = (uint32_t)rsm->r_tim_lastsent[(rsm->r_rtr_cnt - 1)];
8065 			rack->rc_rack_rtt = t;
8066 		}
8067 		return (1);
8068 	}
8069 	/*
8070 	 * We clear the soft/rxtshift since we got an ack.
8071 	 * There is no assurance we will call the commit() function
8072 	 * so we need to clear these to avoid incorrect handling.
8073 	 */
8074 	tp->t_rxtshift = 0;
8075 	RACK_TCPT_RANGESET(tp->t_rxtcur, RACK_REXMTVAL(tp),
8076 		      rack_rto_min, rack_rto_max, rack->r_ctl.timer_slop);
8077 	tp->t_softerror = 0;
8078 	if (to && (to->to_flags & TOF_TS) &&
8079 	    (ack_type == CUM_ACKED) &&
8080 	    (to->to_tsecr) &&
8081 	    ((rsm->r_flags & RACK_OVERMAX) == 0)) {
8082 		/*
8083 		 * Now which timestamp does it match? In this block the ACK
8084 		 * must be coming from a previous transmission.
8085 		 */
8086 		for (i = 0; i < rsm->r_rtr_cnt; i++) {
8087 			if (rack_ts_to_msec(rsm->r_tim_lastsent[i]) == to->to_tsecr) {
8088 				t = cts - (uint32_t)rsm->r_tim_lastsent[i];
8089 				if ((int)t <= 0)
8090 					t = 1;
8091 				if (CC_ALGO(tp)->rttsample != NULL) {
8092 					/*
8093 					 * Kick the RTT to the CC, here
8094 					 * we lie a bit in that we know the
8095 					 * retransmission is correct even though
8096 					 * we retransmitted. This is because
8097 					 * we match the timestamps.
8098 					 */
8099 					if (TSTMP_GT(tcp_tv_to_usectick(&rack->r_ctl.act_rcv_time), rsm->r_tim_lastsent[i]))
8100 						us_rtt = tcp_tv_to_usectick(&rack->r_ctl.act_rcv_time) - (uint32_t)rsm->r_tim_lastsent[i];
8101 					else
8102 						us_rtt = tcp_get_usecs(NULL) - (uint32_t)rsm->r_tim_lastsent[i];
8103 					CC_ALGO(tp)->rttsample(tp->ccv, us_rtt, 1, rsm->r_fas);
8104 				}
8105 				if ((i + 1) < rsm->r_rtr_cnt) {
8106 					/*
8107 					 * The peer ack'd from our previous
8108 					 * transmission. We have a spurious
8109 					 * retransmission and thus we dont
8110 					 * want to update our rack_rtt.
8111 					 *
8112 					 * Hmm should there be a CC revert here?
8113 					 *
8114 					 */
8115 					return (0);
8116 				}
8117 				if (!tp->t_rttlow || tp->t_rttlow > t)
8118 					tp->t_rttlow = t;
8119 				if (!rack->r_ctl.rc_rack_min_rtt || SEQ_LT(t, rack->r_ctl.rc_rack_min_rtt)) {
8120 					rack->r_ctl.rc_rack_min_rtt = t;
8121 					if (rack->r_ctl.rc_rack_min_rtt == 0) {
8122 						rack->r_ctl.rc_rack_min_rtt = 1;
8123 					}
8124 				}
8125 				if (SEQ_LT(rack->r_ctl.rc_rack_tmit_time,
8126 					   (uint32_t)rsm->r_tim_lastsent[(rsm->r_rtr_cnt - 1)])) {
8127 					/* New more recent rack_tmit_time */
8128 					rack->r_ctl.rc_rack_tmit_time = (uint32_t)rsm->r_tim_lastsent[(rsm->r_rtr_cnt - 1)];
8129 					rack->rc_rack_rtt = t;
8130 				}
8131 				rack_log_rtt_sample_calc(rack, t, (uint32_t)rsm->r_tim_lastsent[i], cts, 3);
8132 				tcp_rack_xmit_timer(rack, t + 1, len_acked, t, 0, rsm,
8133 						    rsm->r_rtr_cnt);
8134 				return (1);
8135 			}
8136 		}
8137 		goto ts_not_found;
8138 	} else {
8139 		/*
8140 		 * Ok its a SACK block that we retransmitted. or a windows
8141 		 * machine without timestamps. We can tell nothing from the
8142 		 * time-stamp since its not there or the time the peer last
8143 		 * recieved a segment that moved forward its cum-ack point.
8144 		 */
8145 ts_not_found:
8146 		i = rsm->r_rtr_cnt - 1;
8147 		t = cts - (uint32_t)rsm->r_tim_lastsent[i];
8148 		if ((int)t <= 0)
8149 			t = 1;
8150 		if (rack->r_ctl.rc_rack_min_rtt && SEQ_LT(t, rack->r_ctl.rc_rack_min_rtt)) {
8151 			/*
8152 			 * We retransmitted and the ack came back in less
8153 			 * than the smallest rtt we have observed. We most
8154 			 * likely did an improper retransmit as outlined in
8155 			 * 6.2 Step 2 point 2 in the rack-draft so we
8156 			 * don't want to update our rack_rtt. We in
8157 			 * theory (in future) might want to think about reverting our
8158 			 * cwnd state but we won't for now.
8159 			 */
8160 			return (0);
8161 		} else if (rack->r_ctl.rc_rack_min_rtt) {
8162 			/*
8163 			 * We retransmitted it and the retransmit did the
8164 			 * job.
8165 			 */
8166 			if (!rack->r_ctl.rc_rack_min_rtt ||
8167 			    SEQ_LT(t, rack->r_ctl.rc_rack_min_rtt)) {
8168 				rack->r_ctl.rc_rack_min_rtt = t;
8169 				if (rack->r_ctl.rc_rack_min_rtt == 0) {
8170 					rack->r_ctl.rc_rack_min_rtt = 1;
8171 				}
8172 			}
8173 			if (SEQ_LT(rack->r_ctl.rc_rack_tmit_time, (uint32_t)rsm->r_tim_lastsent[i])) {
8174 				/* New more recent rack_tmit_time */
8175 				rack->r_ctl.rc_rack_tmit_time = (uint32_t)rsm->r_tim_lastsent[i];
8176 				rack->rc_rack_rtt = t;
8177 			}
8178 			return (1);
8179 		}
8180 	}
8181 	return (0);
8182 }
8183 
8184 /*
8185  * Mark the SACK_PASSED flag on all entries prior to rsm send wise.
8186  */
8187 static void
8188 rack_log_sack_passed(struct tcpcb *tp,
8189     struct tcp_rack *rack, struct rack_sendmap *rsm)
8190 {
8191 	struct rack_sendmap *nrsm;
8192 
8193 	nrsm = rsm;
8194 	TAILQ_FOREACH_REVERSE_FROM(nrsm, &rack->r_ctl.rc_tmap,
8195 	    rack_head, r_tnext) {
8196 		if (nrsm == rsm) {
8197 			/* Skip orginal segment he is acked */
8198 			continue;
8199 		}
8200 		if (nrsm->r_flags & RACK_ACKED) {
8201 			/*
8202 			 * Skip ack'd segments, though we
8203 			 * should not see these, since tmap
8204 			 * should not have ack'd segments.
8205 			 */
8206 			continue;
8207 		}
8208 		if (nrsm->r_flags & RACK_SACK_PASSED) {
8209 			/*
8210 			 * We found one that is already marked
8211 			 * passed, we have been here before and
8212 			 * so all others below this are marked.
8213 			 */
8214 			break;
8215 		}
8216 		nrsm->r_flags |= RACK_SACK_PASSED;
8217 		nrsm->r_flags &= ~RACK_WAS_SACKPASS;
8218 	}
8219 }
8220 
8221 static void
8222 rack_need_set_test(struct tcpcb *tp,
8223 		   struct tcp_rack *rack,
8224 		   struct rack_sendmap *rsm,
8225 		   tcp_seq th_ack,
8226 		   int line,
8227 		   int use_which)
8228 {
8229 
8230 	if ((tp->t_flags & TF_GPUTINPROG) &&
8231 	    SEQ_GEQ(rsm->r_end, tp->gput_seq)) {
8232 		/*
8233 		 * We were app limited, and this ack
8234 		 * butts up or goes beyond the point where we want
8235 		 * to start our next measurement. We need
8236 		 * to record the new gput_ts as here and
8237 		 * possibly update the start sequence.
8238 		 */
8239 		uint32_t seq, ts;
8240 
8241 		if (rsm->r_rtr_cnt > 1) {
8242 			/*
8243 			 * This is a retransmit, can we
8244 			 * really make any assessment at this
8245 			 * point?  We are not really sure of
8246 			 * the timestamp, is it this or the
8247 			 * previous transmission?
8248 			 *
8249 			 * Lets wait for something better that
8250 			 * is not retransmitted.
8251 			 */
8252 			return;
8253 		}
8254 		seq = tp->gput_seq;
8255 		ts = tp->gput_ts;
8256 		rack->app_limited_needs_set = 0;
8257 		tp->gput_ts = tcp_tv_to_usectick(&rack->r_ctl.act_rcv_time);
8258 		/* Do we start at a new end? */
8259 		if ((use_which == RACK_USE_BEG) &&
8260 		    SEQ_GEQ(rsm->r_start, tp->gput_seq)) {
8261 			/*
8262 			 * When we get an ACK that just eats
8263 			 * up some of the rsm, we set RACK_USE_BEG
8264 			 * since whats at r_start (i.e. th_ack)
8265 			 * is left unacked and thats where the
8266 			 * measurement not starts.
8267 			 */
8268 			tp->gput_seq = rsm->r_start;
8269 			rack->r_ctl.rc_gp_output_ts = rsm->r_tim_lastsent[(rsm->r_rtr_cnt-1)];
8270 		}
8271 		if ((use_which == RACK_USE_END) &&
8272 		    SEQ_GEQ(rsm->r_end, tp->gput_seq)) {
8273 			    /*
8274 			     * We use the end when the cumack
8275 			     * is moving forward and completely
8276 			     * deleting the rsm passed so basically
8277 			     * r_end holds th_ack.
8278 			     *
8279 			     * For SACK's we also want to use the end
8280 			     * since this piece just got sacked and
8281 			     * we want to target anything after that
8282 			     * in our measurement.
8283 			     */
8284 			    tp->gput_seq = rsm->r_end;
8285 			    rack->r_ctl.rc_gp_output_ts = rsm->r_tim_lastsent[(rsm->r_rtr_cnt-1)];
8286 		}
8287 		if (use_which == RACK_USE_END_OR_THACK) {
8288 			/*
8289 			 * special case for ack moving forward,
8290 			 * not a sack, we need to move all the
8291 			 * way up to where this ack cum-ack moves
8292 			 * to.
8293 			 */
8294 			if (SEQ_GT(th_ack, rsm->r_end))
8295 				tp->gput_seq = th_ack;
8296 			else
8297 				tp->gput_seq = rsm->r_end;
8298 			rack->r_ctl.rc_gp_output_ts = rsm->r_tim_lastsent[(rsm->r_rtr_cnt-1)];
8299 		}
8300 		if (SEQ_GT(tp->gput_seq, tp->gput_ack)) {
8301 			/*
8302 			 * We moved beyond this guy's range, re-calculate
8303 			 * the new end point.
8304 			 */
8305 			if (rack->rc_gp_filled == 0) {
8306 				tp->gput_ack = tp->gput_seq + max(rc_init_window(rack), (MIN_GP_WIN * ctf_fixed_maxseg(tp)));
8307 			} else {
8308 				tp->gput_ack = tp->gput_seq + rack_get_measure_window(tp, rack);
8309 			}
8310 		}
8311 		/*
8312 		 * We are moving the goal post, we may be able to clear the
8313 		 * measure_saw_probe_rtt flag.
8314 		 */
8315 		if ((rack->in_probe_rtt == 0) &&
8316 		    (rack->measure_saw_probe_rtt) &&
8317 		    (SEQ_GEQ(tp->gput_seq, rack->r_ctl.rc_probertt_sndmax_atexit)))
8318 			rack->measure_saw_probe_rtt = 0;
8319 		rack_log_pacing_delay_calc(rack, ts, tp->gput_ts,
8320 					   seq, tp->gput_seq, 0, 5, line, NULL, 0);
8321 		if (rack->rc_gp_filled &&
8322 		    ((tp->gput_ack - tp->gput_seq) <
8323 		     max(rc_init_window(rack), (MIN_GP_WIN *
8324 						ctf_fixed_maxseg(tp))))) {
8325 			uint32_t ideal_amount;
8326 
8327 			ideal_amount = rack_get_measure_window(tp, rack);
8328 			if (ideal_amount > sbavail(&tp->t_inpcb->inp_socket->so_snd)) {
8329 				/*
8330 				 * There is no sense of continuing this measurement
8331 				 * because its too small to gain us anything we
8332 				 * trust. Skip it and that way we can start a new
8333 				 * measurement quicker.
8334 				 */
8335 				tp->t_flags &= ~TF_GPUTINPROG;
8336 				rack_log_pacing_delay_calc(rack, tp->gput_ack, tp->gput_seq,
8337 							   0, 0, 0, 6, __LINE__, NULL, 0);
8338 			} else {
8339 				/*
8340 				 * Reset the window further out.
8341 				 */
8342 				tp->gput_ack = tp->gput_seq + ideal_amount;
8343 			}
8344 		}
8345 	}
8346 }
8347 
8348 static inline int
8349 is_rsm_inside_declared_tlp_block(struct tcp_rack *rack, struct rack_sendmap *rsm)
8350 {
8351 	if (SEQ_LT(rsm->r_end, rack->r_ctl.last_tlp_acked_start)) {
8352 		/* Behind our TLP definition or right at */
8353 		return (0);
8354 	}
8355 	if (SEQ_GT(rsm->r_start, rack->r_ctl.last_tlp_acked_end)) {
8356 		/* The start is beyond or right at our end of TLP definition */
8357 		return (0);
8358 	}
8359 	/* It has to be a sub-part of the original TLP recorded */
8360 	return (1);
8361 }
8362 
8363 
8364 static uint32_t
8365 rack_proc_sack_blk(struct tcpcb *tp, struct tcp_rack *rack, struct sackblk *sack,
8366 		   struct tcpopt *to, struct rack_sendmap **prsm, uint32_t cts, int *moved_two)
8367 {
8368 	uint32_t start, end, changed = 0;
8369 	struct rack_sendmap stack_map;
8370 	struct rack_sendmap *rsm, *nrsm, fe, *insret, *prev, *next;
8371 	int32_t used_ref = 1;
8372 	int moved = 0;
8373 
8374 	start = sack->start;
8375 	end = sack->end;
8376 	rsm = *prsm;
8377 	memset(&fe, 0, sizeof(fe));
8378 do_rest_ofb:
8379 	if ((rsm == NULL) ||
8380 	    (SEQ_LT(end, rsm->r_start)) ||
8381 	    (SEQ_GEQ(start, rsm->r_end)) ||
8382 	    (SEQ_LT(start, rsm->r_start))) {
8383 		/*
8384 		 * We are not in the right spot,
8385 		 * find the correct spot in the tree.
8386 		 */
8387 		used_ref = 0;
8388 		fe.r_start = start;
8389 		rsm = RB_FIND(rack_rb_tree_head, &rack->r_ctl.rc_mtree, &fe);
8390 		moved++;
8391 	}
8392 	if (rsm == NULL) {
8393 		/* TSNH */
8394 		goto out;
8395 	}
8396 	/* Ok we have an ACK for some piece of this rsm */
8397 	if (rsm->r_start != start) {
8398 		if ((rsm->r_flags & RACK_ACKED) == 0) {
8399 			/*
8400 			 * Before any splitting or hookery is
8401 			 * done is it a TLP of interest i.e. rxt?
8402 			 */
8403 			if ((rsm->r_flags & RACK_TLP) &&
8404 			    (rsm->r_rtr_cnt > 1)) {
8405 				/*
8406 				 * We are splitting a rxt TLP, check
8407 				 * if we need to save off the start/end
8408 				 */
8409 				if (rack->rc_last_tlp_acked_set &&
8410 				    (is_rsm_inside_declared_tlp_block(rack, rsm))) {
8411 					/*
8412 					 * We already turned this on since we are inside
8413 					 * the previous one was a partially sack now we
8414 					 * are getting another one (maybe all of it).
8415 					 *
8416 					 */
8417 					rack_log_dsack_event(rack, 10, __LINE__, rsm->r_start, rsm->r_end);
8418 					/*
8419 					 * Lets make sure we have all of it though.
8420 					 */
8421 					if (SEQ_LT(rsm->r_start, rack->r_ctl.last_tlp_acked_start)) {
8422 						rack->r_ctl.last_tlp_acked_start = rsm->r_start;
8423 						rack_log_dsack_event(rack, 11, __LINE__, rack->r_ctl.last_tlp_acked_start,
8424 								     rack->r_ctl.last_tlp_acked_end);
8425 					}
8426 					if (SEQ_GT(rsm->r_end, rack->r_ctl.last_tlp_acked_end)) {
8427 						rack->r_ctl.last_tlp_acked_end = rsm->r_end;
8428 						rack_log_dsack_event(rack, 11, __LINE__, rack->r_ctl.last_tlp_acked_start,
8429 								     rack->r_ctl.last_tlp_acked_end);
8430 					}
8431 				} else {
8432 					rack->r_ctl.last_tlp_acked_start = rsm->r_start;
8433 					rack->r_ctl.last_tlp_acked_end = rsm->r_end;
8434 					rack->rc_last_tlp_past_cumack = 0;
8435 					rack->rc_last_tlp_acked_set = 1;
8436 					rack_log_dsack_event(rack, 8, __LINE__, rsm->r_start, rsm->r_end);
8437 				}
8438 			}
8439 			/**
8440 			 * Need to split this in two pieces the before and after,
8441 			 * the before remains in the map, the after must be
8442 			 * added. In other words we have:
8443 			 * rsm        |--------------|
8444 			 * sackblk        |------->
8445 			 * rsm will become
8446 			 *     rsm    |---|
8447 			 * and nrsm will be  the sacked piece
8448 			 *     nrsm       |----------|
8449 			 *
8450 			 * But before we start down that path lets
8451 			 * see if the sack spans over on top of
8452 			 * the next guy and it is already sacked.
8453 			 *
8454 			 */
8455 			next = RB_NEXT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm);
8456 			if (next && (next->r_flags & RACK_ACKED) &&
8457 			    SEQ_GEQ(end, next->r_start)) {
8458 				/**
8459 				 * So the next one is already acked, and
8460 				 * we can thus by hookery use our stack_map
8461 				 * to reflect the piece being sacked and
8462 				 * then adjust the two tree entries moving
8463 				 * the start and ends around. So we start like:
8464 				 *  rsm     |------------|             (not-acked)
8465 				 *  next                 |-----------| (acked)
8466 				 *  sackblk        |-------->
8467 				 *  We want to end like so:
8468 				 *  rsm     |------|                   (not-acked)
8469 				 *  next           |-----------------| (acked)
8470 				 *  nrsm           |-----|
8471 				 * Where nrsm is a temporary stack piece we
8472 				 * use to update all the gizmos.
8473 				 */
8474 				/* Copy up our fudge block */
8475 				nrsm = &stack_map;
8476 				memcpy(nrsm, rsm, sizeof(struct rack_sendmap));
8477 				/* Now adjust our tree blocks */
8478 				rsm->r_end = start;
8479 				next->r_start = start;
8480 				/* Now we must adjust back where next->m is */
8481 				rack_setup_offset_for_rsm(rsm, next);
8482 
8483 				/* We don't need to adjust rsm, it did not change */
8484 				/* Clear out the dup ack count of the remainder */
8485 				rsm->r_dupack = 0;
8486 				rsm->r_just_ret = 0;
8487 				rack_log_retran_reason(rack, rsm, __LINE__, 0, 2);
8488 				/* Now lets make sure our fudge block is right */
8489 				nrsm->r_start = start;
8490 				/* Now lets update all the stats and such */
8491 				rack_update_rtt(tp, rack, nrsm, to, cts, SACKED, 0);
8492 				if (rack->app_limited_needs_set)
8493 					rack_need_set_test(tp, rack, nrsm, tp->snd_una, __LINE__, RACK_USE_END);
8494 				changed += (nrsm->r_end - nrsm->r_start);
8495 				rack->r_ctl.rc_sacked += (nrsm->r_end - nrsm->r_start);
8496 				if (nrsm->r_flags & RACK_SACK_PASSED) {
8497 					counter_u64_add(rack_reorder_seen, 1);
8498 					rack->r_ctl.rc_reorder_ts = cts;
8499 				}
8500 				/*
8501 				 * Now we want to go up from rsm (the
8502 				 * one left un-acked) to the next one
8503 				 * in the tmap. We do this so when
8504 				 * we walk backwards we include marking
8505 				 * sack-passed on rsm (The one passed in
8506 				 * is skipped since it is generally called
8507 				 * on something sacked before removing it
8508 				 * from the tmap).
8509 				 */
8510 				if (rsm->r_in_tmap) {
8511 					nrsm = TAILQ_NEXT(rsm, r_tnext);
8512 					/*
8513 					 * Now that we have the next
8514 					 * one walk backwards from there.
8515 					 */
8516 					if (nrsm && nrsm->r_in_tmap)
8517 						rack_log_sack_passed(tp, rack, nrsm);
8518 				}
8519 				/* Now are we done? */
8520 				if (SEQ_LT(end, next->r_end) ||
8521 				    (end == next->r_end)) {
8522 					/* Done with block */
8523 					goto out;
8524 				}
8525 				rack_log_map_chg(tp, rack, &stack_map, rsm, next, MAP_SACK_M1, end, __LINE__);
8526 				counter_u64_add(rack_sack_used_next_merge, 1);
8527 				/* Postion for the next block */
8528 				start = next->r_end;
8529 				rsm = RB_NEXT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, next);
8530 				if (rsm == NULL)
8531 					goto out;
8532 			} else {
8533 				/**
8534 				 * We can't use any hookery here, so we
8535 				 * need to split the map. We enter like
8536 				 * so:
8537 				 *  rsm      |--------|
8538 				 *  sackblk       |----->
8539 				 * We will add the new block nrsm and
8540 				 * that will be the new portion, and then
8541 				 * fall through after reseting rsm. So we
8542 				 * split and look like this:
8543 				 *  rsm      |----|
8544 				 *  sackblk       |----->
8545 				 *  nrsm          |---|
8546 				 * We then fall through reseting
8547 				 * rsm to nrsm, so the next block
8548 				 * picks it up.
8549 				 */
8550 				nrsm = rack_alloc_limit(rack, RACK_LIMIT_TYPE_SPLIT);
8551 				if (nrsm == NULL) {
8552 					/*
8553 					 * failed XXXrrs what can we do but loose the sack
8554 					 * info?
8555 					 */
8556 					goto out;
8557 				}
8558 				counter_u64_add(rack_sack_splits, 1);
8559 				rack_clone_rsm(rack, nrsm, rsm, start);
8560 				rsm->r_just_ret = 0;
8561 				insret = RB_INSERT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, nrsm);
8562 #ifdef INVARIANTS
8563 				if (insret != NULL) {
8564 					panic("Insert in rb tree of %p fails ret:%p rack:%p rsm:%p",
8565 					      nrsm, insret, rack, rsm);
8566 				}
8567 #endif
8568 				if (rsm->r_in_tmap) {
8569 					TAILQ_INSERT_AFTER(&rack->r_ctl.rc_tmap, rsm, nrsm, r_tnext);
8570 					nrsm->r_in_tmap = 1;
8571 				}
8572 				rack_log_map_chg(tp, rack, NULL, rsm, nrsm, MAP_SACK_M2, end, __LINE__);
8573 				rsm->r_flags &= (~RACK_HAS_FIN);
8574 				/* Position us to point to the new nrsm that starts the sack blk */
8575 				rsm = nrsm;
8576 			}
8577 		} else {
8578 			/* Already sacked this piece */
8579 			counter_u64_add(rack_sack_skipped_acked, 1);
8580 			moved++;
8581 			if (end == rsm->r_end) {
8582 				/* Done with block */
8583 				rsm = RB_NEXT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm);
8584 				goto out;
8585 			} else if (SEQ_LT(end, rsm->r_end)) {
8586 				/* A partial sack to a already sacked block */
8587 				moved++;
8588 				rsm = RB_NEXT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm);
8589 				goto out;
8590 			} else {
8591 				/*
8592 				 * The end goes beyond this guy
8593 				 * repostion the start to the
8594 				 * next block.
8595 				 */
8596 				start = rsm->r_end;
8597 				rsm = RB_NEXT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm);
8598 				if (rsm == NULL)
8599 					goto out;
8600 			}
8601 		}
8602 	}
8603 	if (SEQ_GEQ(end, rsm->r_end)) {
8604 		/**
8605 		 * The end of this block is either beyond this guy or right
8606 		 * at this guy. I.e.:
8607 		 *  rsm ---                 |-----|
8608 		 *  end                     |-----|
8609 		 *  <or>
8610 		 *  end                     |---------|
8611 		 */
8612 		if ((rsm->r_flags & RACK_ACKED) == 0) {
8613 			/*
8614 			 * Is it a TLP of interest?
8615 			 */
8616 			if ((rsm->r_flags & RACK_TLP) &&
8617 			    (rsm->r_rtr_cnt > 1)) {
8618 				/*
8619 				 * We are splitting a rxt TLP, check
8620 				 * if we need to save off the start/end
8621 				 */
8622 				if (rack->rc_last_tlp_acked_set &&
8623 				    (is_rsm_inside_declared_tlp_block(rack, rsm))) {
8624 					/*
8625 					 * We already turned this on since we are inside
8626 					 * the previous one was a partially sack now we
8627 					 * are getting another one (maybe all of it).
8628 					 */
8629 					rack_log_dsack_event(rack, 10, __LINE__, rsm->r_start, rsm->r_end);
8630 					/*
8631 					 * Lets make sure we have all of it though.
8632 					 */
8633 					if (SEQ_LT(rsm->r_start, rack->r_ctl.last_tlp_acked_start)) {
8634 						rack->r_ctl.last_tlp_acked_start = rsm->r_start;
8635 						rack_log_dsack_event(rack, 11, __LINE__, rack->r_ctl.last_tlp_acked_start,
8636 								     rack->r_ctl.last_tlp_acked_end);
8637 					}
8638 					if (SEQ_GT(rsm->r_end, rack->r_ctl.last_tlp_acked_end)) {
8639 						rack->r_ctl.last_tlp_acked_end = rsm->r_end;
8640 						rack_log_dsack_event(rack, 11, __LINE__, rack->r_ctl.last_tlp_acked_start,
8641 								     rack->r_ctl.last_tlp_acked_end);
8642 					}
8643 				} else {
8644 					rack->r_ctl.last_tlp_acked_start = rsm->r_start;
8645 					rack->r_ctl.last_tlp_acked_end = rsm->r_end;
8646 					rack->rc_last_tlp_past_cumack = 0;
8647 					rack->rc_last_tlp_acked_set = 1;
8648 					rack_log_dsack_event(rack, 8, __LINE__, rsm->r_start, rsm->r_end);
8649 				}
8650 			}
8651 			rack_update_rtt(tp, rack, rsm, to, cts, SACKED, 0);
8652 			changed += (rsm->r_end - rsm->r_start);
8653 			rack->r_ctl.rc_sacked += (rsm->r_end - rsm->r_start);
8654 			if (rsm->r_in_tmap) /* should be true */
8655 				rack_log_sack_passed(tp, rack, rsm);
8656 			/* Is Reordering occuring? */
8657 			if (rsm->r_flags & RACK_SACK_PASSED) {
8658 				rsm->r_flags &= ~RACK_SACK_PASSED;
8659 				counter_u64_add(rack_reorder_seen, 1);
8660 				rack->r_ctl.rc_reorder_ts = cts;
8661 			}
8662 			if (rack->app_limited_needs_set)
8663 				rack_need_set_test(tp, rack, rsm, tp->snd_una, __LINE__, RACK_USE_END);
8664 			rsm->r_ack_arrival = rack_to_usec_ts(&rack->r_ctl.act_rcv_time);
8665 			rsm->r_flags |= RACK_ACKED;
8666 			if (rsm->r_in_tmap) {
8667 				TAILQ_REMOVE(&rack->r_ctl.rc_tmap, rsm, r_tnext);
8668 				rsm->r_in_tmap = 0;
8669 			}
8670 			rack_log_map_chg(tp, rack, NULL, rsm, NULL, MAP_SACK_M3, end, __LINE__);
8671 		} else {
8672 			counter_u64_add(rack_sack_skipped_acked, 1);
8673 			moved++;
8674 		}
8675 		if (end == rsm->r_end) {
8676 			/* This block only - done, setup for next */
8677 			goto out;
8678 		}
8679 		/*
8680 		 * There is more not coverend by this rsm move on
8681 		 * to the next block in the RB tree.
8682 		 */
8683 		nrsm = RB_NEXT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm);
8684 		start = rsm->r_end;
8685 		rsm = nrsm;
8686 		if (rsm == NULL)
8687 			goto out;
8688 		goto do_rest_ofb;
8689 	}
8690 	/**
8691 	 * The end of this sack block is smaller than
8692 	 * our rsm i.e.:
8693 	 *  rsm ---                 |-----|
8694 	 *  end                     |--|
8695 	 */
8696 	if ((rsm->r_flags & RACK_ACKED) == 0) {
8697 		/*
8698 		 * Is it a TLP of interest?
8699 		 */
8700 		if ((rsm->r_flags & RACK_TLP) &&
8701 		    (rsm->r_rtr_cnt > 1)) {
8702 			/*
8703 			 * We are splitting a rxt TLP, check
8704 			 * if we need to save off the start/end
8705 			 */
8706 			if (rack->rc_last_tlp_acked_set &&
8707 			    (is_rsm_inside_declared_tlp_block(rack, rsm))) {
8708 				/*
8709 				 * We already turned this on since we are inside
8710 				 * the previous one was a partially sack now we
8711 				 * are getting another one (maybe all of it).
8712 				 */
8713 				rack_log_dsack_event(rack, 10, __LINE__, rsm->r_start, rsm->r_end);
8714 				/*
8715 				 * Lets make sure we have all of it though.
8716 				 */
8717 				if (SEQ_LT(rsm->r_start, rack->r_ctl.last_tlp_acked_start)) {
8718 					rack->r_ctl.last_tlp_acked_start = rsm->r_start;
8719 					rack_log_dsack_event(rack, 11, __LINE__, rack->r_ctl.last_tlp_acked_start,
8720 							     rack->r_ctl.last_tlp_acked_end);
8721 				}
8722 				if (SEQ_GT(rsm->r_end, rack->r_ctl.last_tlp_acked_end)) {
8723 					rack->r_ctl.last_tlp_acked_end = rsm->r_end;
8724 					rack_log_dsack_event(rack, 11, __LINE__, rack->r_ctl.last_tlp_acked_start,
8725 							     rack->r_ctl.last_tlp_acked_end);
8726 				}
8727 			} else {
8728 				rack->r_ctl.last_tlp_acked_start = rsm->r_start;
8729 				rack->r_ctl.last_tlp_acked_end = rsm->r_end;
8730 				rack->rc_last_tlp_past_cumack = 0;
8731 				rack->rc_last_tlp_acked_set = 1;
8732 				rack_log_dsack_event(rack, 8, __LINE__, rsm->r_start, rsm->r_end);
8733 			}
8734 		}
8735 		prev = RB_PREV(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm);
8736 		if (prev &&
8737 		    (prev->r_flags & RACK_ACKED)) {
8738 			/**
8739 			 * Goal, we want the right remainder of rsm to shrink
8740 			 * in place and span from (rsm->r_start = end) to rsm->r_end.
8741 			 * We want to expand prev to go all the way
8742 			 * to prev->r_end <- end.
8743 			 * so in the tree we have before:
8744 			 *   prev     |--------|         (acked)
8745 			 *   rsm               |-------| (non-acked)
8746 			 *   sackblk           |-|
8747 			 * We churn it so we end up with
8748 			 *   prev     |----------|       (acked)
8749 			 *   rsm                 |-----| (non-acked)
8750 			 *   nrsm              |-| (temporary)
8751 			 *
8752 			 * Note if either prev/rsm is a TLP we don't
8753 			 * do this.
8754 			 */
8755 			nrsm = &stack_map;
8756 			memcpy(nrsm, rsm, sizeof(struct rack_sendmap));
8757 			prev->r_end = end;
8758 			rsm->r_start = end;
8759 			/* Now adjust nrsm (stack copy) to be
8760 			 * the one that is the small
8761 			 * piece that was "sacked".
8762 			 */
8763 			nrsm->r_end = end;
8764 			rsm->r_dupack = 0;
8765 			rack_log_retran_reason(rack, rsm, __LINE__, 0, 2);
8766 			/*
8767 			 * Now that the rsm has had its start moved forward
8768 			 * lets go ahead and get its new place in the world.
8769 			 */
8770 			rack_setup_offset_for_rsm(prev, rsm);
8771 			/*
8772 			 * Now nrsm is our new little piece
8773 			 * that is acked (which was merged
8774 			 * to prev). Update the rtt and changed
8775 			 * based on that. Also check for reordering.
8776 			 */
8777 			rack_update_rtt(tp, rack, nrsm, to, cts, SACKED, 0);
8778 			if (rack->app_limited_needs_set)
8779 				rack_need_set_test(tp, rack, nrsm, tp->snd_una, __LINE__, RACK_USE_END);
8780 			changed += (nrsm->r_end - nrsm->r_start);
8781 			rack->r_ctl.rc_sacked += (nrsm->r_end - nrsm->r_start);
8782 			if (nrsm->r_flags & RACK_SACK_PASSED) {
8783 				counter_u64_add(rack_reorder_seen, 1);
8784 				rack->r_ctl.rc_reorder_ts = cts;
8785 			}
8786 			rack_log_map_chg(tp, rack, prev, &stack_map, rsm, MAP_SACK_M4, end, __LINE__);
8787 			rsm = prev;
8788 			counter_u64_add(rack_sack_used_prev_merge, 1);
8789 		} else {
8790 			/**
8791 			 * This is the case where our previous
8792 			 * block is not acked either, so we must
8793 			 * split the block in two.
8794 			 */
8795 			nrsm = rack_alloc_limit(rack, RACK_LIMIT_TYPE_SPLIT);
8796 			if (nrsm == NULL) {
8797 				/* failed rrs what can we do but loose the sack info? */
8798 				goto out;
8799 			}
8800 			if ((rsm->r_flags & RACK_TLP) &&
8801 			    (rsm->r_rtr_cnt > 1)) {
8802 				/*
8803 				 * We are splitting a rxt TLP, check
8804 				 * if we need to save off the start/end
8805 				 */
8806 				if (rack->rc_last_tlp_acked_set &&
8807 				    (is_rsm_inside_declared_tlp_block(rack, rsm))) {
8808 					    /*
8809 					     * We already turned this on since this block is inside
8810 					     * the previous one was a partially sack now we
8811 					     * are getting another one (maybe all of it).
8812 					     */
8813 					    rack_log_dsack_event(rack, 10, __LINE__, rsm->r_start, rsm->r_end);
8814 					    /*
8815 					     * Lets make sure we have all of it though.
8816 					     */
8817 					    if (SEQ_LT(rsm->r_start, rack->r_ctl.last_tlp_acked_start)) {
8818 						    rack->r_ctl.last_tlp_acked_start = rsm->r_start;
8819 						    rack_log_dsack_event(rack, 11, __LINE__, rack->r_ctl.last_tlp_acked_start,
8820 									 rack->r_ctl.last_tlp_acked_end);
8821 					    }
8822 					    if (SEQ_GT(rsm->r_end, rack->r_ctl.last_tlp_acked_end)) {
8823 						    rack->r_ctl.last_tlp_acked_end = rsm->r_end;
8824 						    rack_log_dsack_event(rack, 11, __LINE__, rack->r_ctl.last_tlp_acked_start,
8825 									 rack->r_ctl.last_tlp_acked_end);
8826 					    }
8827 				    } else {
8828 					    rack->r_ctl.last_tlp_acked_start = rsm->r_start;
8829 					    rack->r_ctl.last_tlp_acked_end = rsm->r_end;
8830 					    rack->rc_last_tlp_acked_set = 1;
8831 					    rack->rc_last_tlp_past_cumack = 0;
8832 					    rack_log_dsack_event(rack, 8, __LINE__, rsm->r_start, rsm->r_end);
8833 				    }
8834 			}
8835 			/**
8836 			 * In this case nrsm becomes
8837 			 * nrsm->r_start = end;
8838 			 * nrsm->r_end = rsm->r_end;
8839 			 * which is un-acked.
8840 			 * <and>
8841 			 * rsm->r_end = nrsm->r_start;
8842 			 * i.e. the remaining un-acked
8843 			 * piece is left on the left
8844 			 * hand side.
8845 			 *
8846 			 * So we start like this
8847 			 * rsm      |----------| (not acked)
8848 			 * sackblk  |---|
8849 			 * build it so we have
8850 			 * rsm      |---|         (acked)
8851 			 * nrsm         |------|  (not acked)
8852 			 */
8853 			counter_u64_add(rack_sack_splits, 1);
8854 			rack_clone_rsm(rack, nrsm, rsm, end);
8855 			rsm->r_flags &= (~RACK_HAS_FIN);
8856 			rsm->r_just_ret = 0;
8857 			insret = RB_INSERT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, nrsm);
8858 #ifdef INVARIANTS
8859 			if (insret != NULL) {
8860 				panic("Insert in rb tree of %p fails ret:%p rack:%p rsm:%p",
8861 				      nrsm, insret, rack, rsm);
8862 			}
8863 #endif
8864 			if (rsm->r_in_tmap) {
8865 				TAILQ_INSERT_AFTER(&rack->r_ctl.rc_tmap, rsm, nrsm, r_tnext);
8866 				nrsm->r_in_tmap = 1;
8867 			}
8868 			nrsm->r_dupack = 0;
8869 			rack_log_retran_reason(rack, nrsm, __LINE__, 0, 2);
8870 			rack_update_rtt(tp, rack, rsm, to, cts, SACKED, 0);
8871 			changed += (rsm->r_end - rsm->r_start);
8872 			rack->r_ctl.rc_sacked += (rsm->r_end - rsm->r_start);
8873 			if (rsm->r_in_tmap) /* should be true */
8874 				rack_log_sack_passed(tp, rack, rsm);
8875 			/* Is Reordering occuring? */
8876 			if (rsm->r_flags & RACK_SACK_PASSED) {
8877 				rsm->r_flags &= ~RACK_SACK_PASSED;
8878 				counter_u64_add(rack_reorder_seen, 1);
8879 				rack->r_ctl.rc_reorder_ts = cts;
8880 			}
8881 			if (rack->app_limited_needs_set)
8882 				rack_need_set_test(tp, rack, rsm, tp->snd_una, __LINE__, RACK_USE_END);
8883 			rsm->r_ack_arrival = rack_to_usec_ts(&rack->r_ctl.act_rcv_time);
8884 			rsm->r_flags |= RACK_ACKED;
8885 			rack_log_map_chg(tp, rack, NULL, rsm, nrsm, MAP_SACK_M5, end, __LINE__);
8886 			if (rsm->r_in_tmap) {
8887 				TAILQ_REMOVE(&rack->r_ctl.rc_tmap, rsm, r_tnext);
8888 				rsm->r_in_tmap = 0;
8889 			}
8890 		}
8891 	} else if (start != end){
8892 		/*
8893 		 * The block was already acked.
8894 		 */
8895 		counter_u64_add(rack_sack_skipped_acked, 1);
8896 		moved++;
8897 	}
8898 out:
8899 	if (rsm &&
8900 	    ((rsm->r_flags & RACK_TLP) == 0) &&
8901 	    (rsm->r_flags & RACK_ACKED)) {
8902 		/*
8903 		 * Now can we merge where we worked
8904 		 * with either the previous or
8905 		 * next block?
8906 		 */
8907 		next = RB_NEXT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm);
8908 		while (next) {
8909 			if (next->r_flags & RACK_TLP)
8910 				break;
8911 			if (next->r_flags & RACK_ACKED) {
8912 			/* yep this and next can be merged */
8913 				rsm = rack_merge_rsm(rack, rsm, next);
8914 				next = RB_NEXT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm);
8915 			} else
8916 				break;
8917 		}
8918 		/* Now what about the previous? */
8919 		prev = RB_PREV(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm);
8920 		while (prev) {
8921 			if (prev->r_flags & RACK_TLP)
8922 				break;
8923 			if (prev->r_flags & RACK_ACKED) {
8924 				/* yep the previous and this can be merged */
8925 				rsm = rack_merge_rsm(rack, prev, rsm);
8926 				prev = RB_PREV(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm);
8927 			} else
8928 				break;
8929 		}
8930 	}
8931 	if (used_ref == 0) {
8932 		counter_u64_add(rack_sack_proc_all, 1);
8933 	} else {
8934 		counter_u64_add(rack_sack_proc_short, 1);
8935 	}
8936 	/* Save off the next one for quick reference. */
8937 	if (rsm)
8938 		nrsm = RB_NEXT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm);
8939 	else
8940 		nrsm = NULL;
8941 	*prsm = rack->r_ctl.rc_sacklast = nrsm;
8942 	/* Pass back the moved. */
8943 	*moved_two = moved;
8944 	return (changed);
8945 }
8946 
8947 static void inline
8948 rack_peer_reneges(struct tcp_rack *rack, struct rack_sendmap *rsm, tcp_seq th_ack)
8949 {
8950 	struct rack_sendmap *tmap;
8951 
8952 	tmap = NULL;
8953 	while (rsm && (rsm->r_flags & RACK_ACKED)) {
8954 		/* Its no longer sacked, mark it so */
8955 		rack->r_ctl.rc_sacked -= (rsm->r_end - rsm->r_start);
8956 #ifdef INVARIANTS
8957 		if (rsm->r_in_tmap) {
8958 			panic("rack:%p rsm:%p flags:0x%x in tmap?",
8959 			      rack, rsm, rsm->r_flags);
8960 		}
8961 #endif
8962 		rsm->r_flags &= ~(RACK_ACKED|RACK_SACK_PASSED|RACK_WAS_SACKPASS);
8963 		/* Rebuild it into our tmap */
8964 		if (tmap == NULL) {
8965 			TAILQ_INSERT_HEAD(&rack->r_ctl.rc_tmap, rsm, r_tnext);
8966 			tmap = rsm;
8967 		} else {
8968 			TAILQ_INSERT_AFTER(&rack->r_ctl.rc_tmap, tmap, rsm, r_tnext);
8969 			tmap = rsm;
8970 		}
8971 		tmap->r_in_tmap = 1;
8972 		rsm = RB_NEXT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm);
8973 	}
8974 	/*
8975 	 * Now lets possibly clear the sack filter so we start
8976 	 * recognizing sacks that cover this area.
8977 	 */
8978 	sack_filter_clear(&rack->r_ctl.rack_sf, th_ack);
8979 
8980 }
8981 
8982 static void
8983 rack_do_decay(struct tcp_rack *rack)
8984 {
8985 	struct timeval res;
8986 
8987 #define	timersub(tvp, uvp, vvp)						\
8988 	do {								\
8989 		(vvp)->tv_sec = (tvp)->tv_sec - (uvp)->tv_sec;		\
8990 		(vvp)->tv_usec = (tvp)->tv_usec - (uvp)->tv_usec;	\
8991 		if ((vvp)->tv_usec < 0) {				\
8992 			(vvp)->tv_sec--;				\
8993 			(vvp)->tv_usec += 1000000;			\
8994 		}							\
8995 	} while (0)
8996 
8997 	timersub(&rack->r_ctl.act_rcv_time, &rack->r_ctl.rc_last_time_decay, &res);
8998 #undef timersub
8999 
9000 	rack->r_ctl.input_pkt++;
9001 	if ((rack->rc_in_persist) ||
9002 	    (res.tv_sec >= 1) ||
9003 	    (rack->rc_tp->snd_max == rack->rc_tp->snd_una)) {
9004 		/*
9005 		 * Check for decay of non-SAD,
9006 		 * we want all SAD detection metrics to
9007 		 * decay 1/4 per second (or more) passed.
9008 		 */
9009 		uint32_t pkt_delta;
9010 
9011 		pkt_delta = rack->r_ctl.input_pkt - rack->r_ctl.saved_input_pkt;
9012 		/* Update our saved tracking values */
9013 		rack->r_ctl.saved_input_pkt = rack->r_ctl.input_pkt;
9014 		rack->r_ctl.rc_last_time_decay = rack->r_ctl.act_rcv_time;
9015 		/* Now do we escape without decay? */
9016 #ifdef NETFLIX_EXP_DETECTION
9017 		if (rack->rc_in_persist ||
9018 		    (rack->rc_tp->snd_max == rack->rc_tp->snd_una) ||
9019 		    (pkt_delta < tcp_sad_low_pps)){
9020 			/*
9021 			 * We don't decay idle connections
9022 			 * or ones that have a low input pps.
9023 			 */
9024 			return;
9025 		}
9026 		/* Decay the counters */
9027 		rack->r_ctl.ack_count = ctf_decay_count(rack->r_ctl.ack_count,
9028 							tcp_sad_decay_val);
9029 		rack->r_ctl.sack_count = ctf_decay_count(rack->r_ctl.sack_count,
9030 							 tcp_sad_decay_val);
9031 		rack->r_ctl.sack_moved_extra = ctf_decay_count(rack->r_ctl.sack_moved_extra,
9032 							       tcp_sad_decay_val);
9033 		rack->r_ctl.sack_noextra_move = ctf_decay_count(rack->r_ctl.sack_noextra_move,
9034 								tcp_sad_decay_val);
9035 #endif
9036 	}
9037 }
9038 
9039 static void
9040 rack_process_to_cumack(struct tcpcb *tp, struct tcp_rack *rack, register uint32_t th_ack, uint32_t cts, struct tcpopt *to)
9041 {
9042 	struct rack_sendmap *rsm, *rm;
9043 
9044 	/*
9045 	 * The ACK point is advancing to th_ack, we must drop off
9046 	 * the packets in the rack log and calculate any eligble
9047 	 * RTT's.
9048 	 */
9049 	rack->r_wanted_output = 1;
9050 
9051 	/* Tend any TLP that has been marked for 1/2 the seq space (its old)  */
9052 	if ((rack->rc_last_tlp_acked_set == 1)&&
9053 	    (rack->rc_last_tlp_past_cumack == 1) &&
9054 	    (SEQ_GT(rack->r_ctl.last_tlp_acked_start, th_ack))) {
9055 		/*
9056 		 * We have reached the point where our last rack
9057 		 * tlp retransmit sequence is ahead of the cum-ack.
9058 		 * This can only happen when the cum-ack moves all
9059 		 * the way around (its been a full 2^^31+1 bytes
9060 		 * or more since we sent a retransmitted TLP). Lets
9061 		 * turn off the valid flag since its not really valid.
9062 		 *
9063 		 * Note since sack's also turn on this event we have
9064 		 * a complication, we have to wait to age it out until
9065 		 * the cum-ack is by the TLP before checking which is
9066 		 * what the next else clause does.
9067 		 */
9068 		rack_log_dsack_event(rack, 9, __LINE__,
9069 				     rack->r_ctl.last_tlp_acked_start,
9070 				     rack->r_ctl.last_tlp_acked_end);
9071 		rack->rc_last_tlp_acked_set = 0;
9072 		rack->rc_last_tlp_past_cumack = 0;
9073 	} else if ((rack->rc_last_tlp_acked_set == 1) &&
9074 		   (rack->rc_last_tlp_past_cumack == 0) &&
9075 		   (SEQ_GEQ(th_ack, rack->r_ctl.last_tlp_acked_end))) {
9076 		/*
9077 		 * It is safe to start aging TLP's out.
9078 		 */
9079 		rack->rc_last_tlp_past_cumack = 1;
9080 	}
9081 	/* We do the same for the tlp send seq as well */
9082 	if ((rack->rc_last_sent_tlp_seq_valid == 1) &&
9083 	    (rack->rc_last_sent_tlp_past_cumack == 1) &&
9084 	    (SEQ_GT(rack->r_ctl.last_sent_tlp_seq,  th_ack))) {
9085 		rack_log_dsack_event(rack, 9, __LINE__,
9086 				     rack->r_ctl.last_sent_tlp_seq,
9087 				     (rack->r_ctl.last_sent_tlp_seq +
9088 				      rack->r_ctl.last_sent_tlp_len));
9089 		rack->rc_last_sent_tlp_seq_valid = 0;
9090 		rack->rc_last_sent_tlp_past_cumack = 0;
9091 	} else if ((rack->rc_last_sent_tlp_seq_valid == 1) &&
9092 		   (rack->rc_last_sent_tlp_past_cumack == 0) &&
9093 		   (SEQ_GEQ(th_ack, rack->r_ctl.last_sent_tlp_seq))) {
9094 		/*
9095 		 * It is safe to start aging TLP's send.
9096 		 */
9097 		rack->rc_last_sent_tlp_past_cumack = 1;
9098 	}
9099 more:
9100 	rsm = RB_MIN(rack_rb_tree_head, &rack->r_ctl.rc_mtree);
9101 	if (rsm == NULL) {
9102 		if ((th_ack - 1) == tp->iss) {
9103 			/*
9104 			 * For the SYN incoming case we will not
9105 			 * have called tcp_output for the sending of
9106 			 * the SYN, so there will be no map. All
9107 			 * other cases should probably be a panic.
9108 			 */
9109 			return;
9110 		}
9111 		if (tp->t_flags & TF_SENTFIN) {
9112 			/* if we sent a FIN we often will not have map */
9113 			return;
9114 		}
9115 #ifdef INVARIANTS
9116 		panic("No rack map tp:%p for state:%d ack:%u rack:%p snd_una:%u snd_max:%u snd_nxt:%u\n",
9117 		      tp,
9118 		      tp->t_state, th_ack, rack,
9119 		      tp->snd_una, tp->snd_max, tp->snd_nxt);
9120 #endif
9121 		return;
9122 	}
9123 	if (SEQ_LT(th_ack, rsm->r_start)) {
9124 		/* Huh map is missing this */
9125 #ifdef INVARIANTS
9126 		printf("Rack map starts at r_start:%u for th_ack:%u huh? ts:%d rs:%d\n",
9127 		       rsm->r_start,
9128 		       th_ack, tp->t_state, rack->r_state);
9129 #endif
9130 		return;
9131 	}
9132 	rack_update_rtt(tp, rack, rsm, to, cts, CUM_ACKED, th_ack);
9133 
9134 	/* Now was it a retransmitted TLP? */
9135 	if ((rsm->r_flags & RACK_TLP) &&
9136 	    (rsm->r_rtr_cnt > 1)) {
9137 		/*
9138 		 * Yes, this rsm was a TLP and retransmitted, remember that
9139 		 * since if a DSACK comes back on this we don't want
9140 		 * to think of it as a reordered segment. This may
9141 		 * get updated again with possibly even other TLPs
9142 		 * in flight, but thats ok. Only when we don't send
9143 		 * a retransmitted TLP for 1/2 the sequences space
9144 		 * will it get turned off (above).
9145 		 */
9146 		if (rack->rc_last_tlp_acked_set &&
9147 		    (is_rsm_inside_declared_tlp_block(rack, rsm))) {
9148 			/*
9149 			 * We already turned this on since the end matches,
9150 			 * the previous one was a partially ack now we
9151 			 * are getting another one (maybe all of it).
9152 			 */
9153 			rack_log_dsack_event(rack, 10, __LINE__, rsm->r_start, rsm->r_end);
9154 			/*
9155 			 * Lets make sure we have all of it though.
9156 			 */
9157 			if (SEQ_LT(rsm->r_start, rack->r_ctl.last_tlp_acked_start)) {
9158 				rack->r_ctl.last_tlp_acked_start = rsm->r_start;
9159 				rack_log_dsack_event(rack, 11, __LINE__, rack->r_ctl.last_tlp_acked_start,
9160 						     rack->r_ctl.last_tlp_acked_end);
9161 			}
9162 			if (SEQ_GT(rsm->r_end, rack->r_ctl.last_tlp_acked_end)) {
9163 				rack->r_ctl.last_tlp_acked_end = rsm->r_end;
9164 				rack_log_dsack_event(rack, 11, __LINE__, rack->r_ctl.last_tlp_acked_start,
9165 						     rack->r_ctl.last_tlp_acked_end);
9166 			}
9167 		} else {
9168 			rack->rc_last_tlp_past_cumack = 1;
9169 			rack->r_ctl.last_tlp_acked_start = rsm->r_start;
9170 			rack->r_ctl.last_tlp_acked_end = rsm->r_end;
9171 			rack->rc_last_tlp_acked_set = 1;
9172 			rack_log_dsack_event(rack, 8, __LINE__, rsm->r_start, rsm->r_end);
9173 		}
9174 	}
9175 	/* Now do we consume the whole thing? */
9176 	if (SEQ_GEQ(th_ack, rsm->r_end)) {
9177 		/* Its all consumed. */
9178 		uint32_t left;
9179 		uint8_t newly_acked;
9180 
9181 		rack_log_map_chg(tp, rack, NULL, rsm, NULL, MAP_FREE, rsm->r_end, __LINE__);
9182 		rack->r_ctl.rc_holes_rxt -= rsm->r_rtr_bytes;
9183 		rsm->r_rtr_bytes = 0;
9184 		/* Record the time of highest cumack sent */
9185 		rack->r_ctl.rc_gp_cumack_ts = rsm->r_tim_lastsent[(rsm->r_rtr_cnt-1)];
9186 		rm = RB_REMOVE(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm);
9187 #ifdef INVARIANTS
9188 		if (rm != rsm) {
9189 			panic("removing head in rack:%p rsm:%p rm:%p",
9190 			      rack, rsm, rm);
9191 		}
9192 #endif
9193 		if (rsm->r_in_tmap) {
9194 			TAILQ_REMOVE(&rack->r_ctl.rc_tmap, rsm, r_tnext);
9195 			rsm->r_in_tmap = 0;
9196 		}
9197 		newly_acked = 1;
9198 		if (rsm->r_flags & RACK_ACKED) {
9199 			/*
9200 			 * It was acked on the scoreboard -- remove
9201 			 * it from total
9202 			 */
9203 			rack->r_ctl.rc_sacked -= (rsm->r_end - rsm->r_start);
9204 			newly_acked = 0;
9205 		} else if (rsm->r_flags & RACK_SACK_PASSED) {
9206 			/*
9207 			 * There are segments ACKED on the
9208 			 * scoreboard further up. We are seeing
9209 			 * reordering.
9210 			 */
9211 			rsm->r_flags &= ~RACK_SACK_PASSED;
9212 			counter_u64_add(rack_reorder_seen, 1);
9213 			rsm->r_ack_arrival = rack_to_usec_ts(&rack->r_ctl.act_rcv_time);
9214 			rsm->r_flags |= RACK_ACKED;
9215 			rack->r_ctl.rc_reorder_ts = cts;
9216 			if (rack->r_ent_rec_ns) {
9217 				/*
9218 				 * We have sent no more, and we saw an sack
9219 				 * then ack arrive.
9220 				 */
9221 				rack->r_might_revert = 1;
9222 			}
9223 		}
9224 		if ((rsm->r_flags & RACK_TO_REXT) &&
9225 		    (tp->t_flags & TF_RCVD_TSTMP) &&
9226 		    (to->to_flags & TOF_TS) &&
9227 		    (to->to_tsecr != 0) &&
9228 		    (tp->t_flags & TF_PREVVALID)) {
9229 			/*
9230 			 * We can use the timestamp to see
9231 			 * if this retransmission was from the
9232 			 * first transmit. If so we made a mistake.
9233 			 */
9234 			tp->t_flags &= ~TF_PREVVALID;
9235 			if (to->to_tsecr == rack_ts_to_msec(rsm->r_tim_lastsent[0])) {
9236 				/* The first transmit is what this ack is for */
9237 				rack_cong_signal(tp, CC_RTO_ERR, th_ack);
9238 			}
9239 		}
9240 		left = th_ack - rsm->r_end;
9241 		if (rack->app_limited_needs_set && newly_acked)
9242 			rack_need_set_test(tp, rack, rsm, th_ack, __LINE__, RACK_USE_END_OR_THACK);
9243 		/* Free back to zone */
9244 		rack_free(rack, rsm);
9245 		if (left) {
9246 			goto more;
9247 		}
9248 		/* Check for reneging */
9249 		rsm = RB_MIN(rack_rb_tree_head, &rack->r_ctl.rc_mtree);
9250 		if (rsm && (rsm->r_flags & RACK_ACKED) && (th_ack == rsm->r_start)) {
9251 			/*
9252 			 * The peer has moved snd_una up to
9253 			 * the edge of this send, i.e. one
9254 			 * that it had previously acked. The only
9255 			 * way that can be true if the peer threw
9256 			 * away data (space issues) that it had
9257 			 * previously sacked (else it would have
9258 			 * given us snd_una up to (rsm->r_end).
9259 			 * We need to undo the acked markings here.
9260 			 *
9261 			 * Note we have to look to make sure th_ack is
9262 			 * our rsm->r_start in case we get an old ack
9263 			 * where th_ack is behind snd_una.
9264 			 */
9265 			rack_peer_reneges(rack, rsm, th_ack);
9266 		}
9267 		return;
9268 	}
9269 	if (rsm->r_flags & RACK_ACKED) {
9270 		/*
9271 		 * It was acked on the scoreboard -- remove it from
9272 		 * total for the part being cum-acked.
9273 		 */
9274 		rack->r_ctl.rc_sacked -= (th_ack - rsm->r_start);
9275 	}
9276 	/*
9277 	 * Clear the dup ack count for
9278 	 * the piece that remains.
9279 	 */
9280 	rsm->r_dupack = 0;
9281 	rack_log_retran_reason(rack, rsm, __LINE__, 0, 2);
9282 	if (rsm->r_rtr_bytes) {
9283 		/*
9284 		 * It was retransmitted adjust the
9285 		 * sack holes for what was acked.
9286 		 */
9287 		int ack_am;
9288 
9289 		ack_am = (th_ack - rsm->r_start);
9290 		if (ack_am >= rsm->r_rtr_bytes) {
9291 			rack->r_ctl.rc_holes_rxt -= ack_am;
9292 			rsm->r_rtr_bytes -= ack_am;
9293 		}
9294 	}
9295 	/*
9296 	 * Update where the piece starts and record
9297 	 * the time of send of highest cumack sent.
9298 	 */
9299 	rack->r_ctl.rc_gp_cumack_ts = rsm->r_tim_lastsent[(rsm->r_rtr_cnt-1)];
9300 	rack_log_map_chg(tp, rack, NULL, rsm, NULL, MAP_TRIM_HEAD, th_ack, __LINE__);
9301 	/* Now we need to move our offset forward too */
9302 	if (rsm->m && (rsm->orig_m_len != rsm->m->m_len)) {
9303 		/* Fix up the orig_m_len and possibly the mbuf offset */
9304 		rack_adjust_orig_mlen(rsm);
9305 	}
9306 	rsm->soff += (th_ack - rsm->r_start);
9307 	rsm->r_start = th_ack;
9308 	/* Now do we need to move the mbuf fwd too? */
9309 	if (rsm->m) {
9310 		while (rsm->soff >= rsm->m->m_len) {
9311 			rsm->soff -= rsm->m->m_len;
9312 			rsm->m = rsm->m->m_next;
9313 			KASSERT((rsm->m != NULL),
9314 				(" nrsm:%p hit at soff:%u null m",
9315 				 rsm, rsm->soff));
9316 		}
9317 		rsm->orig_m_len = rsm->m->m_len;
9318 	}
9319 	if (rack->app_limited_needs_set)
9320 		rack_need_set_test(tp, rack, rsm, tp->snd_una, __LINE__, RACK_USE_BEG);
9321 }
9322 
9323 static void
9324 rack_handle_might_revert(struct tcpcb *tp, struct tcp_rack *rack)
9325 {
9326 	struct rack_sendmap *rsm;
9327 	int sack_pass_fnd = 0;
9328 
9329 	if (rack->r_might_revert) {
9330 		/*
9331 		 * Ok we have reordering, have not sent anything, we
9332 		 * might want to revert the congestion state if nothing
9333 		 * further has SACK_PASSED on it. Lets check.
9334 		 *
9335 		 * We also get here when we have DSACKs come in for
9336 		 * all the data that we FR'd. Note that a rxt or tlp
9337 		 * timer clears this from happening.
9338 		 */
9339 
9340 		TAILQ_FOREACH(rsm, &rack->r_ctl.rc_tmap, r_tnext) {
9341 			if (rsm->r_flags & RACK_SACK_PASSED) {
9342 				sack_pass_fnd = 1;
9343 				break;
9344 			}
9345 		}
9346 		if (sack_pass_fnd == 0) {
9347 			/*
9348 			 * We went into recovery
9349 			 * incorrectly due to reordering!
9350 			 */
9351 			int orig_cwnd;
9352 
9353 			rack->r_ent_rec_ns = 0;
9354 			orig_cwnd = tp->snd_cwnd;
9355 			tp->snd_cwnd = rack->r_ctl.rc_cwnd_at_erec;
9356 			tp->snd_ssthresh = rack->r_ctl.rc_ssthresh_at_erec;
9357 			tp->snd_recover = tp->snd_una;
9358 			rack_log_to_prr(rack, 14, orig_cwnd);
9359 			EXIT_RECOVERY(tp->t_flags);
9360 		}
9361 		rack->r_might_revert = 0;
9362 	}
9363 }
9364 
9365 #ifdef NETFLIX_EXP_DETECTION
9366 static void
9367 rack_do_detection(struct tcpcb *tp, struct tcp_rack *rack,  uint32_t bytes_this_ack, uint32_t segsiz)
9368 {
9369 	if ((rack->do_detection || tcp_force_detection) &&
9370 	    tcp_sack_to_ack_thresh &&
9371 	    tcp_sack_to_move_thresh &&
9372 	    ((rack->r_ctl.rc_num_maps_alloced > tcp_map_minimum) || rack->sack_attack_disable)) {
9373 		/*
9374 		 * We have thresholds set to find
9375 		 * possible attackers and disable sack.
9376 		 * Check them.
9377 		 */
9378 		uint64_t ackratio, moveratio, movetotal;
9379 
9380 		/* Log detecting */
9381 		rack_log_sad(rack, 1);
9382 		ackratio = (uint64_t)(rack->r_ctl.sack_count);
9383 		ackratio *= (uint64_t)(1000);
9384 		if (rack->r_ctl.ack_count)
9385 			ackratio /= (uint64_t)(rack->r_ctl.ack_count);
9386 		else {
9387 			/* We really should not hit here */
9388 			ackratio = 1000;
9389 		}
9390 		if ((rack->sack_attack_disable == 0) &&
9391 		    (ackratio > rack_highest_sack_thresh_seen))
9392 			rack_highest_sack_thresh_seen = (uint32_t)ackratio;
9393 		movetotal = rack->r_ctl.sack_moved_extra;
9394 		movetotal += rack->r_ctl.sack_noextra_move;
9395 		moveratio = rack->r_ctl.sack_moved_extra;
9396 		moveratio *= (uint64_t)1000;
9397 		if (movetotal)
9398 			moveratio /= movetotal;
9399 		else {
9400 			/* No moves, thats pretty good */
9401 			moveratio = 0;
9402 		}
9403 		if ((rack->sack_attack_disable == 0) &&
9404 		    (moveratio > rack_highest_move_thresh_seen))
9405 			rack_highest_move_thresh_seen = (uint32_t)moveratio;
9406 		if (rack->sack_attack_disable == 0) {
9407 			if ((ackratio > tcp_sack_to_ack_thresh) &&
9408 			    (moveratio > tcp_sack_to_move_thresh)) {
9409 				/* Disable sack processing */
9410 				rack->sack_attack_disable = 1;
9411 				if (rack->r_rep_attack == 0) {
9412 					rack->r_rep_attack = 1;
9413 					counter_u64_add(rack_sack_attacks_detected, 1);
9414 				}
9415 				if (tcp_attack_on_turns_on_logging) {
9416 					/*
9417 					 * Turn on logging, used for debugging
9418 					 * false positives.
9419 					 */
9420 					rack->rc_tp->t_logstate = tcp_attack_on_turns_on_logging;
9421 				}
9422 				/* Clamp the cwnd at flight size */
9423 				rack->r_ctl.rc_saved_cwnd = rack->rc_tp->snd_cwnd;
9424 				rack->rc_tp->snd_cwnd = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
9425 				rack_log_sad(rack, 2);
9426 			}
9427 		} else {
9428 			/* We are sack-disabled check for false positives */
9429 			if ((ackratio <= tcp_restoral_thresh) ||
9430 			    (rack->r_ctl.rc_num_maps_alloced  < tcp_map_minimum)) {
9431 				rack->sack_attack_disable = 0;
9432 				rack_log_sad(rack, 3);
9433 				/* Restart counting */
9434 				rack->r_ctl.sack_count = 0;
9435 				rack->r_ctl.sack_moved_extra = 0;
9436 				rack->r_ctl.sack_noextra_move = 1;
9437 				rack->r_ctl.ack_count = max(1,
9438 				      (bytes_this_ack / segsiz));
9439 
9440 				if (rack->r_rep_reverse == 0) {
9441 					rack->r_rep_reverse = 1;
9442 					counter_u64_add(rack_sack_attacks_reversed, 1);
9443 				}
9444 				/* Restore the cwnd */
9445 				if (rack->r_ctl.rc_saved_cwnd > rack->rc_tp->snd_cwnd)
9446 					rack->rc_tp->snd_cwnd = rack->r_ctl.rc_saved_cwnd;
9447 			}
9448 		}
9449 	}
9450 }
9451 #endif
9452 
9453 static int
9454 rack_note_dsack(struct tcp_rack *rack, tcp_seq start, tcp_seq end)
9455 {
9456 
9457 	uint32_t am, l_end;
9458 	int was_tlp = 0;
9459 
9460 	if (SEQ_GT(end, start))
9461 		am = end - start;
9462 	else
9463 		am = 0;
9464 	if ((rack->rc_last_tlp_acked_set ) &&
9465 	    (SEQ_GEQ(start, rack->r_ctl.last_tlp_acked_start)) &&
9466 	    (SEQ_LEQ(end, rack->r_ctl.last_tlp_acked_end))) {
9467 		/*
9468 		 * The DSACK is because of a TLP which we don't
9469 		 * do anything with the reordering window over since
9470 		 * it was not reordering that caused the DSACK but
9471 		 * our previous retransmit TLP.
9472 		 */
9473 		rack_log_dsack_event(rack, 7, __LINE__, start, end);
9474 		was_tlp = 1;
9475 		goto skip_dsack_round;
9476 	}
9477 	if (rack->rc_last_sent_tlp_seq_valid) {
9478 		l_end = rack->r_ctl.last_sent_tlp_seq + rack->r_ctl.last_sent_tlp_len;
9479 		if (SEQ_GEQ(start, rack->r_ctl.last_sent_tlp_seq) &&
9480 		    (SEQ_LEQ(end, l_end))) {
9481 			/*
9482 			 * This dsack is from the last sent TLP, ignore it
9483 			 * for reordering purposes.
9484 			 */
9485 			rack_log_dsack_event(rack, 7, __LINE__, start, end);
9486 			was_tlp = 1;
9487 			goto skip_dsack_round;
9488 		}
9489 	}
9490 	if (rack->rc_dsack_round_seen == 0) {
9491 		rack->rc_dsack_round_seen = 1;
9492 		rack->r_ctl.dsack_round_end = rack->rc_tp->snd_max;
9493 		rack->r_ctl.num_dsack++;
9494 		rack->r_ctl.dsack_persist = 16;	/* 16 is from the standard */
9495 		rack_log_dsack_event(rack, 2, __LINE__, 0, 0);
9496 	}
9497 skip_dsack_round:
9498 	/*
9499 	 * We keep track of how many DSACK blocks we get
9500 	 * after a recovery incident.
9501 	 */
9502 	rack->r_ctl.dsack_byte_cnt += am;
9503 	if (!IN_FASTRECOVERY(rack->rc_tp->t_flags) &&
9504 	    rack->r_ctl.retran_during_recovery &&
9505 	    (rack->r_ctl.dsack_byte_cnt >= rack->r_ctl.retran_during_recovery)) {
9506 		/*
9507 		 * False recovery most likely culprit is reordering. If
9508 		 * nothing else is missing we need to revert.
9509 		 */
9510 		rack->r_might_revert = 1;
9511 		rack_handle_might_revert(rack->rc_tp, rack);
9512 		rack->r_might_revert = 0;
9513 		rack->r_ctl.retran_during_recovery = 0;
9514 		rack->r_ctl.dsack_byte_cnt = 0;
9515 	}
9516 	return (was_tlp);
9517 }
9518 
9519 static void
9520 rack_update_prr(struct tcpcb *tp, struct tcp_rack *rack, uint32_t changed, tcp_seq th_ack)
9521 {
9522 	/* Deal with changed and PRR here (in recovery only) */
9523 	uint32_t pipe, snd_una;
9524 
9525 	rack->r_ctl.rc_prr_delivered += changed;
9526 
9527 	if (sbavail(&rack->rc_inp->inp_socket->so_snd) <= (tp->snd_max - tp->snd_una)) {
9528 		/*
9529 		 * It is all outstanding, we are application limited
9530 		 * and thus we don't need more room to send anything.
9531 		 * Note we use tp->snd_una here and not th_ack because
9532 		 * the data as yet not been cut from the sb.
9533 		 */
9534 		rack->r_ctl.rc_prr_sndcnt = 0;
9535 		return;
9536 	}
9537 	/* Compute prr_sndcnt */
9538 	if (SEQ_GT(tp->snd_una, th_ack)) {
9539 		snd_una = tp->snd_una;
9540 	} else {
9541 		snd_una = th_ack;
9542 	}
9543 	pipe = ((tp->snd_max - snd_una) - rack->r_ctl.rc_sacked) + rack->r_ctl.rc_holes_rxt;
9544 	if (pipe > tp->snd_ssthresh) {
9545 		long sndcnt;
9546 
9547 		sndcnt = rack->r_ctl.rc_prr_delivered * tp->snd_ssthresh;
9548 		if (rack->r_ctl.rc_prr_recovery_fs > 0)
9549 			sndcnt /= (long)rack->r_ctl.rc_prr_recovery_fs;
9550 		else {
9551 			rack->r_ctl.rc_prr_sndcnt = 0;
9552 			rack_log_to_prr(rack, 9, 0);
9553 			sndcnt = 0;
9554 		}
9555 		sndcnt++;
9556 		if (sndcnt > (long)rack->r_ctl.rc_prr_out)
9557 			sndcnt -= rack->r_ctl.rc_prr_out;
9558 		else
9559 			sndcnt = 0;
9560 		rack->r_ctl.rc_prr_sndcnt = sndcnt;
9561 		rack_log_to_prr(rack, 10, 0);
9562 	} else {
9563 		uint32_t limit;
9564 
9565 		if (rack->r_ctl.rc_prr_delivered > rack->r_ctl.rc_prr_out)
9566 			limit = (rack->r_ctl.rc_prr_delivered - rack->r_ctl.rc_prr_out);
9567 		else
9568 			limit = 0;
9569 		if (changed > limit)
9570 			limit = changed;
9571 		limit += ctf_fixed_maxseg(tp);
9572 		if (tp->snd_ssthresh > pipe) {
9573 			rack->r_ctl.rc_prr_sndcnt = min((tp->snd_ssthresh - pipe), limit);
9574 			rack_log_to_prr(rack, 11, 0);
9575 		} else {
9576 			rack->r_ctl.rc_prr_sndcnt = min(0, limit);
9577 			rack_log_to_prr(rack, 12, 0);
9578 		}
9579 	}
9580 }
9581 
9582 static void
9583 rack_log_ack(struct tcpcb *tp, struct tcpopt *to, struct tcphdr *th, int entered_recovery, int dup_ack_struck)
9584 {
9585 	uint32_t changed;
9586 	struct tcp_rack *rack;
9587 	struct rack_sendmap *rsm;
9588 	struct sackblk sack, sack_blocks[TCP_MAX_SACK + 1];
9589 	register uint32_t th_ack;
9590 	int32_t i, j, k, num_sack_blks = 0;
9591 	uint32_t cts, acked, ack_point, sack_changed = 0;
9592 	int loop_start = 0, moved_two = 0;
9593 	uint32_t tsused;
9594 
9595 
9596 	INP_WLOCK_ASSERT(tp->t_inpcb);
9597 	if (th->th_flags & TH_RST) {
9598 		/* We don't log resets */
9599 		return;
9600 	}
9601 	rack = (struct tcp_rack *)tp->t_fb_ptr;
9602 	cts = tcp_get_usecs(NULL);
9603 	rsm = RB_MIN(rack_rb_tree_head, &rack->r_ctl.rc_mtree);
9604 	changed = 0;
9605 	th_ack = th->th_ack;
9606 	if (rack->sack_attack_disable == 0)
9607 		rack_do_decay(rack);
9608 	if (BYTES_THIS_ACK(tp, th) >= ctf_fixed_maxseg(rack->rc_tp)) {
9609 		/*
9610 		 * You only get credit for
9611 		 * MSS and greater (and you get extra
9612 		 * credit for larger cum-ack moves).
9613 		 */
9614 		int ac;
9615 
9616 		ac = BYTES_THIS_ACK(tp, th) / ctf_fixed_maxseg(rack->rc_tp);
9617 		rack->r_ctl.ack_count += ac;
9618 		counter_u64_add(rack_ack_total, ac);
9619 	}
9620 	if (rack->r_ctl.ack_count > 0xfff00000) {
9621 		/*
9622 		 * reduce the number to keep us under
9623 		 * a uint32_t.
9624 		 */
9625 		rack->r_ctl.ack_count /= 2;
9626 		rack->r_ctl.sack_count /= 2;
9627 	}
9628 	if (SEQ_GT(th_ack, tp->snd_una)) {
9629 		rack_log_progress_event(rack, tp, ticks, PROGRESS_UPDATE, __LINE__);
9630 		tp->t_acktime = ticks;
9631 	}
9632 	if (rsm && SEQ_GT(th_ack, rsm->r_start))
9633 		changed = th_ack - rsm->r_start;
9634 	if (changed) {
9635 		rack_process_to_cumack(tp, rack, th_ack, cts, to);
9636 	}
9637 	if ((to->to_flags & TOF_SACK) == 0) {
9638 		/* We are done nothing left and no sack. */
9639 		rack_handle_might_revert(tp, rack);
9640 		/*
9641 		 * For cases where we struck a dup-ack
9642 		 * with no SACK, add to the changes so
9643 		 * PRR will work right.
9644 		 */
9645 		if (dup_ack_struck && (changed == 0)) {
9646 			changed += ctf_fixed_maxseg(rack->rc_tp);
9647 		}
9648 		goto out;
9649 	}
9650 	/* Sack block processing */
9651 	if (SEQ_GT(th_ack, tp->snd_una))
9652 		ack_point = th_ack;
9653 	else
9654 		ack_point = tp->snd_una;
9655 	for (i = 0; i < to->to_nsacks; i++) {
9656 		bcopy((to->to_sacks + i * TCPOLEN_SACK),
9657 		      &sack, sizeof(sack));
9658 		sack.start = ntohl(sack.start);
9659 		sack.end = ntohl(sack.end);
9660 		if (SEQ_GT(sack.end, sack.start) &&
9661 		    SEQ_GT(sack.start, ack_point) &&
9662 		    SEQ_LT(sack.start, tp->snd_max) &&
9663 		    SEQ_GT(sack.end, ack_point) &&
9664 		    SEQ_LEQ(sack.end, tp->snd_max)) {
9665 			sack_blocks[num_sack_blks] = sack;
9666 			num_sack_blks++;
9667 		} else if (SEQ_LEQ(sack.start, th_ack) &&
9668 			   SEQ_LEQ(sack.end, th_ack)) {
9669 			int was_tlp;
9670 
9671 			was_tlp = rack_note_dsack(rack, sack.start, sack.end);
9672 			/*
9673 			 * Its a D-SACK block.
9674 			 */
9675 			tcp_record_dsack(tp, sack.start, sack.end, was_tlp);
9676 		}
9677 	}
9678 	if (rack->rc_dsack_round_seen) {
9679 		/* Is the dsack roound over? */
9680 		if (SEQ_GEQ(th_ack, rack->r_ctl.dsack_round_end)) {
9681 			/* Yes it is */
9682 			rack->rc_dsack_round_seen = 0;
9683 			rack_log_dsack_event(rack, 3, __LINE__, 0, 0);
9684 		}
9685 	}
9686 	/*
9687 	 * Sort the SACK blocks so we can update the rack scoreboard with
9688 	 * just one pass.
9689 	 */
9690 	num_sack_blks = sack_filter_blks(&rack->r_ctl.rack_sf, sack_blocks,
9691 					 num_sack_blks, th->th_ack);
9692 	ctf_log_sack_filter(rack->rc_tp, num_sack_blks, sack_blocks);
9693 	if (num_sack_blks == 0) {
9694 		/* Nothing to sack (DSACKs?) */
9695 		goto out_with_totals;
9696 	}
9697 	if (num_sack_blks < 2) {
9698 		/* Only one, we don't need to sort */
9699 		goto do_sack_work;
9700 	}
9701 	/* Sort the sacks */
9702 	for (i = 0; i < num_sack_blks; i++) {
9703 		for (j = i + 1; j < num_sack_blks; j++) {
9704 			if (SEQ_GT(sack_blocks[i].end, sack_blocks[j].end)) {
9705 				sack = sack_blocks[i];
9706 				sack_blocks[i] = sack_blocks[j];
9707 				sack_blocks[j] = sack;
9708 			}
9709 		}
9710 	}
9711 	/*
9712 	 * Now are any of the sack block ends the same (yes some
9713 	 * implementations send these)?
9714 	 */
9715 again:
9716 	if (num_sack_blks == 0)
9717 		goto out_with_totals;
9718 	if (num_sack_blks > 1) {
9719 		for (i = 0; i < num_sack_blks; i++) {
9720 			for (j = i + 1; j < num_sack_blks; j++) {
9721 				if (sack_blocks[i].end == sack_blocks[j].end) {
9722 					/*
9723 					 * Ok these two have the same end we
9724 					 * want the smallest end and then
9725 					 * throw away the larger and start
9726 					 * again.
9727 					 */
9728 					if (SEQ_LT(sack_blocks[j].start, sack_blocks[i].start)) {
9729 						/*
9730 						 * The second block covers
9731 						 * more area use that
9732 						 */
9733 						sack_blocks[i].start = sack_blocks[j].start;
9734 					}
9735 					/*
9736 					 * Now collapse out the dup-sack and
9737 					 * lower the count
9738 					 */
9739 					for (k = (j + 1); k < num_sack_blks; k++) {
9740 						sack_blocks[j].start = sack_blocks[k].start;
9741 						sack_blocks[j].end = sack_blocks[k].end;
9742 						j++;
9743 					}
9744 					num_sack_blks--;
9745 					goto again;
9746 				}
9747 			}
9748 		}
9749 	}
9750 do_sack_work:
9751 	/*
9752 	 * First lets look to see if
9753 	 * we have retransmitted and
9754 	 * can use the transmit next?
9755 	 */
9756 	rsm = TAILQ_FIRST(&rack->r_ctl.rc_tmap);
9757 	if (rsm &&
9758 	    SEQ_GT(sack_blocks[0].end, rsm->r_start) &&
9759 	    SEQ_LT(sack_blocks[0].start, rsm->r_end)) {
9760 		/*
9761 		 * We probably did the FR and the next
9762 		 * SACK in continues as we would expect.
9763 		 */
9764 		acked = rack_proc_sack_blk(tp, rack, &sack_blocks[0], to, &rsm, cts, &moved_two);
9765 		if (acked) {
9766 			rack->r_wanted_output = 1;
9767 			changed += acked;
9768 			sack_changed += acked;
9769 		}
9770 		if (num_sack_blks == 1) {
9771 			/*
9772 			 * This is what we would expect from
9773 			 * a normal implementation to happen
9774 			 * after we have retransmitted the FR,
9775 			 * i.e the sack-filter pushes down
9776 			 * to 1 block and the next to be retransmitted
9777 			 * is the sequence in the sack block (has more
9778 			 * are acked). Count this as ACK'd data to boost
9779 			 * up the chances of recovering any false positives.
9780 			 */
9781 			rack->r_ctl.ack_count += (acked / ctf_fixed_maxseg(rack->rc_tp));
9782 			counter_u64_add(rack_ack_total, (acked / ctf_fixed_maxseg(rack->rc_tp)));
9783 			counter_u64_add(rack_express_sack, 1);
9784 			if (rack->r_ctl.ack_count > 0xfff00000) {
9785 				/*
9786 				 * reduce the number to keep us under
9787 				 * a uint32_t.
9788 				 */
9789 				rack->r_ctl.ack_count /= 2;
9790 				rack->r_ctl.sack_count /= 2;
9791 			}
9792 			goto out_with_totals;
9793 		} else {
9794 			/*
9795 			 * Start the loop through the
9796 			 * rest of blocks, past the first block.
9797 			 */
9798 			moved_two = 0;
9799 			loop_start = 1;
9800 		}
9801 	}
9802 	/* Its a sack of some sort */
9803 	rack->r_ctl.sack_count++;
9804 	if (rack->r_ctl.sack_count > 0xfff00000) {
9805 		/*
9806 		 * reduce the number to keep us under
9807 		 * a uint32_t.
9808 		 */
9809 		rack->r_ctl.ack_count /= 2;
9810 		rack->r_ctl.sack_count /= 2;
9811 	}
9812 	counter_u64_add(rack_sack_total, 1);
9813 	if (rack->sack_attack_disable) {
9814 		/* An attacker disablement is in place */
9815 		if (num_sack_blks > 1) {
9816 			rack->r_ctl.sack_count += (num_sack_blks - 1);
9817 			rack->r_ctl.sack_moved_extra++;
9818 			counter_u64_add(rack_move_some, 1);
9819 			if (rack->r_ctl.sack_moved_extra > 0xfff00000) {
9820 				rack->r_ctl.sack_moved_extra /= 2;
9821 				rack->r_ctl.sack_noextra_move /= 2;
9822 			}
9823 		}
9824 		goto out;
9825 	}
9826 	rsm = rack->r_ctl.rc_sacklast;
9827 	for (i = loop_start; i < num_sack_blks; i++) {
9828 		acked = rack_proc_sack_blk(tp, rack, &sack_blocks[i], to, &rsm, cts, &moved_two);
9829 		if (acked) {
9830 			rack->r_wanted_output = 1;
9831 			changed += acked;
9832 			sack_changed += acked;
9833 		}
9834 		if (moved_two) {
9835 			/*
9836 			 * If we did not get a SACK for at least a MSS and
9837 			 * had to move at all, or if we moved more than our
9838 			 * threshold, it counts against the "extra" move.
9839 			 */
9840 			rack->r_ctl.sack_moved_extra += moved_two;
9841 			counter_u64_add(rack_move_some, 1);
9842 		} else {
9843 			/*
9844 			 * else we did not have to move
9845 			 * any more than we would expect.
9846 			 */
9847 			rack->r_ctl.sack_noextra_move++;
9848 			counter_u64_add(rack_move_none, 1);
9849 		}
9850 		if (moved_two && (acked < ctf_fixed_maxseg(rack->rc_tp))) {
9851 			/*
9852 			 * If the SACK was not a full MSS then
9853 			 * we add to sack_count the number of
9854 			 * MSS's (or possibly more than
9855 			 * a MSS if its a TSO send) we had to skip by.
9856 			 */
9857 			rack->r_ctl.sack_count += moved_two;
9858 			counter_u64_add(rack_sack_total, moved_two);
9859 		}
9860 		/*
9861 		 * Now we need to setup for the next
9862 		 * round. First we make sure we won't
9863 		 * exceed the size of our uint32_t on
9864 		 * the various counts, and then clear out
9865 		 * moved_two.
9866 		 */
9867 		if ((rack->r_ctl.sack_moved_extra > 0xfff00000) ||
9868 		    (rack->r_ctl.sack_noextra_move > 0xfff00000)) {
9869 			rack->r_ctl.sack_moved_extra /= 2;
9870 			rack->r_ctl.sack_noextra_move /= 2;
9871 		}
9872 		if (rack->r_ctl.sack_count > 0xfff00000) {
9873 			rack->r_ctl.ack_count /= 2;
9874 			rack->r_ctl.sack_count /= 2;
9875 		}
9876 		moved_two = 0;
9877 	}
9878 out_with_totals:
9879 	if (num_sack_blks > 1) {
9880 		/*
9881 		 * You get an extra stroke if
9882 		 * you have more than one sack-blk, this
9883 		 * could be where we are skipping forward
9884 		 * and the sack-filter is still working, or
9885 		 * it could be an attacker constantly
9886 		 * moving us.
9887 		 */
9888 		rack->r_ctl.sack_moved_extra++;
9889 		counter_u64_add(rack_move_some, 1);
9890 	}
9891 out:
9892 #ifdef NETFLIX_EXP_DETECTION
9893 	rack_do_detection(tp, rack, BYTES_THIS_ACK(tp, th), ctf_fixed_maxseg(rack->rc_tp));
9894 #endif
9895 	if (changed) {
9896 		/* Something changed cancel the rack timer */
9897 		rack_timer_cancel(tp, rack, rack->r_ctl.rc_rcvtime, __LINE__);
9898 	}
9899 	tsused = tcp_get_usecs(NULL);
9900 	rsm = tcp_rack_output(tp, rack, tsused);
9901 	if ((!IN_FASTRECOVERY(tp->t_flags)) &&
9902 	    rsm) {
9903 		/* Enter recovery */
9904 		rack->r_ctl.rc_rsm_start = rsm->r_start;
9905 		rack->r_ctl.rc_cwnd_at = tp->snd_cwnd;
9906 		rack->r_ctl.rc_ssthresh_at = tp->snd_ssthresh;
9907 		entered_recovery = 1;
9908 		rack_cong_signal(tp, CC_NDUPACK, tp->snd_una);
9909 		/*
9910 		 * When we enter recovery we need to assure we send
9911 		 * one packet.
9912 		 */
9913 		if (rack->rack_no_prr == 0) {
9914 			rack->r_ctl.rc_prr_sndcnt = ctf_fixed_maxseg(tp);
9915 			rack_log_to_prr(rack, 8, 0);
9916 		}
9917 		rack->r_timer_override = 1;
9918 		rack->r_early = 0;
9919 		rack->r_ctl.rc_agg_early = 0;
9920 	} else if (IN_FASTRECOVERY(tp->t_flags) &&
9921 		   rsm &&
9922 		   (rack->r_rr_config == 3)) {
9923 		/*
9924 		 * Assure we can output and we get no
9925 		 * remembered pace time except the retransmit.
9926 		 */
9927 		rack->r_timer_override = 1;
9928 		rack->r_ctl.rc_hpts_flags &= ~PACE_PKT_OUTPUT;
9929 		rack->r_ctl.rc_resend = rsm;
9930 	}
9931 	if (IN_FASTRECOVERY(tp->t_flags) &&
9932 	    (rack->rack_no_prr == 0) &&
9933 	    (entered_recovery == 0)) {
9934 		rack_update_prr(tp, rack, changed, th_ack);
9935 		if ((rsm && (rack->r_ctl.rc_prr_sndcnt >= ctf_fixed_maxseg(tp)) &&
9936 		     ((rack->rc_inp->inp_in_hpts == 0) &&
9937 		      ((rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT) == 0)))) {
9938 			/*
9939 			 * If you are pacing output you don't want
9940 			 * to override.
9941 			 */
9942 			rack->r_early = 0;
9943 			rack->r_ctl.rc_agg_early = 0;
9944 			rack->r_timer_override = 1;
9945 		}
9946 	}
9947 }
9948 
9949 static void
9950 rack_strike_dupack(struct tcp_rack *rack)
9951 {
9952 	struct rack_sendmap *rsm;
9953 
9954 	rsm = TAILQ_FIRST(&rack->r_ctl.rc_tmap);
9955 	while (rsm && (rsm->r_dupack >= DUP_ACK_THRESHOLD)) {
9956 		rsm = TAILQ_NEXT(rsm, r_tnext);
9957 	}
9958 	if (rsm && (rsm->r_dupack < 0xff)) {
9959 		rsm->r_dupack++;
9960 		if (rsm->r_dupack >= DUP_ACK_THRESHOLD) {
9961 			struct timeval tv;
9962 			uint32_t cts;
9963 			/*
9964 			 * Here we see if we need to retransmit. For
9965 			 * a SACK type connection if enough time has passed
9966 			 * we will get a return of the rsm. For a non-sack
9967 			 * connection we will get the rsm returned if the
9968 			 * dupack value is 3 or more.
9969 			 */
9970 			cts = tcp_get_usecs(&tv);
9971 			rack->r_ctl.rc_resend = tcp_rack_output(rack->rc_tp, rack, cts);
9972 			if (rack->r_ctl.rc_resend != NULL) {
9973 				if (!IN_FASTRECOVERY(rack->rc_tp->t_flags)) {
9974 					rack_cong_signal(rack->rc_tp, CC_NDUPACK,
9975 							 rack->rc_tp->snd_una);
9976 				}
9977 				rack->r_wanted_output = 1;
9978 				rack->r_timer_override = 1;
9979 				rack_log_retran_reason(rack, rsm, __LINE__, 1, 3);
9980 			}
9981 		} else {
9982 			rack_log_retran_reason(rack, rsm, __LINE__, 0, 3);
9983 		}
9984 	}
9985 }
9986 
9987 static void
9988 rack_check_bottom_drag(struct tcpcb *tp,
9989 		       struct tcp_rack *rack,
9990 		       struct socket *so, int32_t acked)
9991 {
9992 	uint32_t segsiz, minseg;
9993 
9994 	segsiz = ctf_fixed_maxseg(tp);
9995 	minseg = segsiz;
9996 
9997 	if (tp->snd_max == tp->snd_una) {
9998 		/*
9999 		 * We are doing dynamic pacing and we are way
10000 		 * under. Basically everything got acked while
10001 		 * we were still waiting on the pacer to expire.
10002 		 *
10003 		 * This means we need to boost the b/w in
10004 		 * addition to any earlier boosting of
10005 		 * the multipler.
10006 		 */
10007 		rack->rc_dragged_bottom = 1;
10008 		rack_validate_multipliers_at_or_above100(rack);
10009 		/*
10010 		 * Lets use the segment bytes acked plus
10011 		 * the lowest RTT seen as the basis to
10012 		 * form a b/w estimate. This will be off
10013 		 * due to the fact that the true estimate
10014 		 * should be around 1/2 the time of the RTT
10015 		 * but we can settle for that.
10016 		 */
10017 		if ((rack->r_ctl.rack_rs.rs_flags & RACK_RTT_VALID) &&
10018 		    acked) {
10019 			uint64_t bw, calc_bw, rtt;
10020 
10021 			rtt = rack->r_ctl.rack_rs.rs_us_rtt;
10022 			if (rtt == 0) {
10023 				/* no us sample is there a ms one? */
10024 				if (rack->r_ctl.rack_rs.rs_rtt_lowest) {
10025 					rtt = rack->r_ctl.rack_rs.rs_rtt_lowest;
10026 				} else {
10027 					goto no_measurement;
10028 				}
10029 			}
10030 			bw = acked;
10031 			calc_bw = bw * 1000000;
10032 			calc_bw /= rtt;
10033 			if (rack->r_ctl.last_max_bw &&
10034 			    (rack->r_ctl.last_max_bw < calc_bw)) {
10035 				/*
10036 				 * If we have a last calculated max bw
10037 				 * enforce it.
10038 				 */
10039 				calc_bw = rack->r_ctl.last_max_bw;
10040 			}
10041 			/* now plop it in */
10042 			if (rack->rc_gp_filled == 0) {
10043 				if (calc_bw > ONE_POINT_TWO_MEG) {
10044 					/*
10045 					 * If we have no measurement
10046 					 * don't let us set in more than
10047 					 * 1.2Mbps. If we are still too
10048 					 * low after pacing with this we
10049 					 * will hopefully have a max b/w
10050 					 * available to sanity check things.
10051 					 */
10052 					calc_bw = ONE_POINT_TWO_MEG;
10053 				}
10054 				rack->r_ctl.rc_rtt_diff = 0;
10055 				rack->r_ctl.gp_bw = calc_bw;
10056 				rack->rc_gp_filled = 1;
10057 				if (rack->r_ctl.num_measurements < RACK_REQ_AVG)
10058 					rack->r_ctl.num_measurements = RACK_REQ_AVG;
10059 				rack_set_pace_segments(rack->rc_tp, rack, __LINE__, NULL);
10060 			} else if (calc_bw > rack->r_ctl.gp_bw) {
10061 				rack->r_ctl.rc_rtt_diff = 0;
10062 				if (rack->r_ctl.num_measurements < RACK_REQ_AVG)
10063 					rack->r_ctl.num_measurements = RACK_REQ_AVG;
10064 				rack->r_ctl.gp_bw = calc_bw;
10065 				rack_set_pace_segments(rack->rc_tp, rack, __LINE__, NULL);
10066 			} else
10067 				rack_increase_bw_mul(rack, -1, 0, 0, 1);
10068 			if ((rack->gp_ready == 0) &&
10069 			    (rack->r_ctl.num_measurements >= rack->r_ctl.req_measurements)) {
10070 				/* We have enough measurements now */
10071 				rack->gp_ready = 1;
10072 				rack_set_cc_pacing(rack);
10073 				if (rack->defer_options)
10074 					rack_apply_deferred_options(rack);
10075 			}
10076 			/*
10077 			 * For acks over 1mss we do a extra boost to simulate
10078 			 * where we would get 2 acks (we want 110 for the mul).
10079 			 */
10080 			if (acked > segsiz)
10081 				rack_increase_bw_mul(rack, -1, 0, 0, 1);
10082 		} else {
10083 			/*
10084 			 * zero rtt possibly?, settle for just an old increase.
10085 			 */
10086 no_measurement:
10087 			rack_increase_bw_mul(rack, -1, 0, 0, 1);
10088 		}
10089 	} else if ((IN_FASTRECOVERY(tp->t_flags) == 0) &&
10090 		   (sbavail(&so->so_snd) > max((segsiz * (4 + rack_req_segs)),
10091 					       minseg)) &&
10092 		   (rack->r_ctl.cwnd_to_use > max((segsiz * (rack_req_segs + 2)), minseg)) &&
10093 		   (tp->snd_wnd > max((segsiz * (rack_req_segs + 2)), minseg)) &&
10094 		   (ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked) <=
10095 		    (segsiz * rack_req_segs))) {
10096 		/*
10097 		 * We are doing dynamic GP pacing and
10098 		 * we have everything except 1MSS or less
10099 		 * bytes left out. We are still pacing away.
10100 		 * And there is data that could be sent, This
10101 		 * means we are inserting delayed ack time in
10102 		 * our measurements because we are pacing too slow.
10103 		 */
10104 		rack_validate_multipliers_at_or_above100(rack);
10105 		rack->rc_dragged_bottom = 1;
10106 		rack_increase_bw_mul(rack, -1, 0, 0, 1);
10107 	}
10108 }
10109 
10110 
10111 
10112 static void
10113 rack_gain_for_fastoutput(struct tcp_rack *rack, struct tcpcb *tp, struct socket *so, uint32_t acked_amount)
10114 {
10115 	/*
10116 	 * The fast output path is enabled and we
10117 	 * have moved the cumack forward. Lets see if
10118 	 * we can expand forward the fast path length by
10119 	 * that amount. What we would ideally like to
10120 	 * do is increase the number of bytes in the
10121 	 * fast path block (left_to_send) by the
10122 	 * acked amount. However we have to gate that
10123 	 * by two factors:
10124 	 * 1) The amount outstanding and the rwnd of the peer
10125 	 *    (i.e. we don't want to exceed the rwnd of the peer).
10126 	 *    <and>
10127 	 * 2) The amount of data left in the socket buffer (i.e.
10128 	 *    we can't send beyond what is in the buffer).
10129 	 *
10130 	 * Note that this does not take into account any increase
10131 	 * in the cwnd. We will only extend the fast path by
10132 	 * what was acked.
10133 	 */
10134 	uint32_t new_total, gating_val;
10135 
10136 	new_total = acked_amount + rack->r_ctl.fsb.left_to_send;
10137 	gating_val = min((sbavail(&so->so_snd) - (tp->snd_max - tp->snd_una)),
10138 			 (tp->snd_wnd - (tp->snd_max - tp->snd_una)));
10139 	if (new_total <= gating_val) {
10140 		/* We can increase left_to_send by the acked amount */
10141 		counter_u64_add(rack_extended_rfo, 1);
10142 		rack->r_ctl.fsb.left_to_send = new_total;
10143 		KASSERT((rack->r_ctl.fsb.left_to_send <= (sbavail(&rack->rc_inp->inp_socket->so_snd) - (tp->snd_max - tp->snd_una))),
10144 			("rack:%p left_to_send:%u sbavail:%u out:%u",
10145 			 rack, rack->r_ctl.fsb.left_to_send,
10146 			 sbavail(&rack->rc_inp->inp_socket->so_snd),
10147 			 (tp->snd_max - tp->snd_una)));
10148 
10149 	}
10150 }
10151 
10152 static void
10153 rack_adjust_sendmap(struct tcp_rack *rack, struct sockbuf *sb, tcp_seq snd_una)
10154 {
10155 	/*
10156 	 * Here any sendmap entry that points to the
10157 	 * beginning mbuf must be adjusted to the correct
10158 	 * offset. This must be called with:
10159 	 * 1) The socket buffer locked
10160 	 * 2) snd_una adjusted to its new postion.
10161 	 *
10162 	 * Note that (2) implies rack_ack_received has also
10163 	 * been called.
10164 	 *
10165 	 * We grab the first mbuf in the socket buffer and
10166 	 * then go through the front of the sendmap, recalculating
10167 	 * the stored offset for any sendmap entry that has
10168 	 * that mbuf. We must use the sb functions to do this
10169 	 * since its possible an add was done has well as
10170 	 * the subtraction we may have just completed. This should
10171 	 * not be a penalty though, since we just referenced the sb
10172 	 * to go in and trim off the mbufs that we freed (of course
10173 	 * there will be a penalty for the sendmap references though).
10174 	 */
10175 	struct mbuf *m;
10176 	struct rack_sendmap *rsm;
10177 
10178 	SOCKBUF_LOCK_ASSERT(sb);
10179 	m = sb->sb_mb;
10180 	rsm = RB_MIN(rack_rb_tree_head, &rack->r_ctl.rc_mtree);
10181 	if ((rsm == NULL) || (m == NULL)) {
10182 		/* Nothing outstanding */
10183 		return;
10184 	}
10185 	while (rsm->m && (rsm->m == m)) {
10186 		/* one to adjust */
10187 #ifdef INVARIANTS
10188 		struct mbuf *tm;
10189 		uint32_t soff;
10190 
10191 		tm = sbsndmbuf(sb, (rsm->r_start - snd_una), &soff);
10192 		if (rsm->orig_m_len != m->m_len) {
10193 			rack_adjust_orig_mlen(rsm);
10194 		}
10195 		if (rsm->soff != soff) {
10196 			/*
10197 			 * This is not a fatal error, we anticipate it
10198 			 * might happen (the else code), so we count it here
10199 			 * so that under invariant we can see that it really
10200 			 * does happen.
10201 			 */
10202 			counter_u64_add(rack_adjust_map_bw, 1);
10203 		}
10204 		rsm->m = tm;
10205 		rsm->soff = soff;
10206 		if (tm)
10207 			rsm->orig_m_len = rsm->m->m_len;
10208 		else
10209 			rsm->orig_m_len = 0;
10210 #else
10211 		rsm->m = sbsndmbuf(sb, (rsm->r_start - snd_una), &rsm->soff);
10212 		if (rsm->m)
10213 			rsm->orig_m_len = rsm->m->m_len;
10214 		else
10215 			rsm->orig_m_len = 0;
10216 #endif
10217 		rsm = RB_NEXT(rack_rb_tree_head, &rack->r_ctl.rc_mtree,
10218 			      rsm);
10219 		if (rsm == NULL)
10220 			break;
10221 	}
10222 }
10223 
10224 /*
10225  * Return value of 1, we do not need to call rack_process_data().
10226  * return value of 0, rack_process_data can be called.
10227  * For ret_val if its 0 the TCP is locked, if its non-zero
10228  * its unlocked and probably unsafe to touch the TCB.
10229  */
10230 static int
10231 rack_process_ack(struct mbuf *m, struct tcphdr *th, struct socket *so,
10232     struct tcpcb *tp, struct tcpopt *to,
10233     uint32_t tiwin, int32_t tlen,
10234     int32_t * ofia, int32_t thflags, int32_t *ret_val)
10235 {
10236 	int32_t ourfinisacked = 0;
10237 	int32_t nsegs, acked_amount;
10238 	int32_t acked;
10239 	struct mbuf *mfree;
10240 	struct tcp_rack *rack;
10241 	int32_t under_pacing = 0;
10242 	int32_t recovery = 0;
10243 
10244 	rack = (struct tcp_rack *)tp->t_fb_ptr;
10245 	if (SEQ_GT(th->th_ack, tp->snd_max)) {
10246 		__ctf_do_dropafterack(m, tp, th, thflags, tlen, ret_val,
10247 				      &rack->r_ctl.challenge_ack_ts,
10248 				      &rack->r_ctl.challenge_ack_cnt);
10249 		rack->r_wanted_output = 1;
10250 		return (1);
10251 	}
10252 	if (rack->gp_ready &&
10253 	    (rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT)) {
10254 		under_pacing = 1;
10255 	}
10256 	if (SEQ_GEQ(th->th_ack, tp->snd_una) || to->to_nsacks) {
10257 		int in_rec, dup_ack_struck = 0;
10258 
10259 		in_rec = IN_FASTRECOVERY(tp->t_flags);
10260 		if (rack->rc_in_persist) {
10261 			tp->t_rxtshift = 0;
10262 			RACK_TCPT_RANGESET(tp->t_rxtcur, RACK_REXMTVAL(tp),
10263 				      rack_rto_min, rack_rto_max, rack->r_ctl.timer_slop);
10264 		}
10265 		if ((th->th_ack == tp->snd_una) &&
10266 		    (tiwin == tp->snd_wnd) &&
10267 		    ((to->to_flags & TOF_SACK) == 0)) {
10268 			rack_strike_dupack(rack);
10269 			dup_ack_struck = 1;
10270 		}
10271 		rack_log_ack(tp, to, th, ((in_rec == 0) && IN_FASTRECOVERY(tp->t_flags)), dup_ack_struck);
10272 	}
10273 	if (__predict_false(SEQ_LEQ(th->th_ack, tp->snd_una))) {
10274 		/*
10275 		 * Old ack, behind (or duplicate to) the last one rcv'd
10276 		 * Note: We mark reordering is occuring if its
10277 		 * less than and we have not closed our window.
10278 		 */
10279 		if (SEQ_LT(th->th_ack, tp->snd_una) && (sbspace(&so->so_rcv) > ctf_fixed_maxseg(tp))) {
10280 			counter_u64_add(rack_reorder_seen, 1);
10281 			rack->r_ctl.rc_reorder_ts = tcp_tv_to_usectick(&rack->r_ctl.act_rcv_time);
10282 		}
10283 		return (0);
10284 	}
10285 	/*
10286 	 * If we reach this point, ACK is not a duplicate, i.e., it ACKs
10287 	 * something we sent.
10288 	 */
10289 	if (tp->t_flags & TF_NEEDSYN) {
10290 		/*
10291 		 * T/TCP: Connection was half-synchronized, and our SYN has
10292 		 * been ACK'd (so connection is now fully synchronized).  Go
10293 		 * to non-starred state, increment snd_una for ACK of SYN,
10294 		 * and check if we can do window scaling.
10295 		 */
10296 		tp->t_flags &= ~TF_NEEDSYN;
10297 		tp->snd_una++;
10298 		/* Do window scaling? */
10299 		if ((tp->t_flags & (TF_RCVD_SCALE | TF_REQ_SCALE)) ==
10300 		    (TF_RCVD_SCALE | TF_REQ_SCALE)) {
10301 			tp->rcv_scale = tp->request_r_scale;
10302 			/* Send window already scaled. */
10303 		}
10304 	}
10305 	nsegs = max(1, m->m_pkthdr.lro_nsegs);
10306 	INP_WLOCK_ASSERT(tp->t_inpcb);
10307 
10308 	acked = BYTES_THIS_ACK(tp, th);
10309 	KMOD_TCPSTAT_ADD(tcps_rcvackpack, nsegs);
10310 	KMOD_TCPSTAT_ADD(tcps_rcvackbyte, acked);
10311 	/*
10312 	 * If we just performed our first retransmit, and the ACK arrives
10313 	 * within our recovery window, then it was a mistake to do the
10314 	 * retransmit in the first place.  Recover our original cwnd and
10315 	 * ssthresh, and proceed to transmit where we left off.
10316 	 */
10317 	if ((tp->t_flags & TF_PREVVALID) &&
10318 	    ((tp->t_flags & TF_RCVD_TSTMP) == 0)) {
10319 		tp->t_flags &= ~TF_PREVVALID;
10320 		if (tp->t_rxtshift == 1 &&
10321 		    (int)(ticks - tp->t_badrxtwin) < 0)
10322 			rack_cong_signal(tp, CC_RTO_ERR, th->th_ack);
10323 	}
10324 	if (acked) {
10325 		/* assure we are not backed off */
10326 		tp->t_rxtshift = 0;
10327 		RACK_TCPT_RANGESET(tp->t_rxtcur, RACK_REXMTVAL(tp),
10328 			      rack_rto_min, rack_rto_max, rack->r_ctl.timer_slop);
10329 		rack->rc_tlp_in_progress = 0;
10330 		rack->r_ctl.rc_tlp_cnt_out = 0;
10331 		/*
10332 		 * If it is the RXT timer we want to
10333 		 * stop it, so we can restart a TLP.
10334 		 */
10335 		if (rack->r_ctl.rc_hpts_flags & PACE_TMR_RXT)
10336 			rack_timer_cancel(tp, rack, rack->r_ctl.rc_rcvtime, __LINE__);
10337 #ifdef NETFLIX_HTTP_LOGGING
10338 		tcp_http_check_for_comp(rack->rc_tp, th->th_ack);
10339 #endif
10340 	}
10341 	/*
10342 	 * If we have a timestamp reply, update smoothed round trip time. If
10343 	 * no timestamp is present but transmit timer is running and timed
10344 	 * sequence number was acked, update smoothed round trip time. Since
10345 	 * we now have an rtt measurement, cancel the timer backoff (cf.,
10346 	 * Phil Karn's retransmit alg.). Recompute the initial retransmit
10347 	 * timer.
10348 	 *
10349 	 * Some boxes send broken timestamp replies during the SYN+ACK
10350 	 * phase, ignore timestamps of 0 or we could calculate a huge RTT
10351 	 * and blow up the retransmit timer.
10352 	 */
10353 	/*
10354 	 * If all outstanding data is acked, stop retransmit timer and
10355 	 * remember to restart (more output or persist). If there is more
10356 	 * data to be acked, restart retransmit timer, using current
10357 	 * (possibly backed-off) value.
10358 	 */
10359 	if (acked == 0) {
10360 		if (ofia)
10361 			*ofia = ourfinisacked;
10362 		return (0);
10363 	}
10364 	if (IN_RECOVERY(tp->t_flags)) {
10365 		if (SEQ_LT(th->th_ack, tp->snd_recover) &&
10366 		    (SEQ_LT(th->th_ack, tp->snd_max))) {
10367 			tcp_rack_partialack(tp);
10368 		} else {
10369 			rack_post_recovery(tp, th->th_ack);
10370 			recovery = 1;
10371 		}
10372 	}
10373 	/*
10374 	 * Let the congestion control algorithm update congestion control
10375 	 * related information. This typically means increasing the
10376 	 * congestion window.
10377 	 */
10378 	rack_ack_received(tp, rack, th->th_ack, nsegs, CC_ACK, recovery);
10379 	SOCKBUF_LOCK(&so->so_snd);
10380 	acked_amount = min(acked, (int)sbavail(&so->so_snd));
10381 	tp->snd_wnd -= acked_amount;
10382 	mfree = sbcut_locked(&so->so_snd, acked_amount);
10383 	if ((sbused(&so->so_snd) == 0) &&
10384 	    (acked > acked_amount) &&
10385 	    (tp->t_state >= TCPS_FIN_WAIT_1) &&
10386 	    (tp->t_flags & TF_SENTFIN)) {
10387 		/*
10388 		 * We must be sure our fin
10389 		 * was sent and acked (we can be
10390 		 * in FIN_WAIT_1 without having
10391 		 * sent the fin).
10392 		 */
10393 		ourfinisacked = 1;
10394 	}
10395 	tp->snd_una = th->th_ack;
10396 	if (acked_amount && sbavail(&so->so_snd))
10397 		rack_adjust_sendmap(rack, &so->so_snd, tp->snd_una);
10398 	rack_log_wakeup(tp,rack, &so->so_snd, acked, 2);
10399 	/* NB: sowwakeup_locked() does an implicit unlock. */
10400 	sowwakeup_locked(so);
10401 	m_freem(mfree);
10402 	if (SEQ_GT(tp->snd_una, tp->snd_recover))
10403 		tp->snd_recover = tp->snd_una;
10404 
10405 	if (SEQ_LT(tp->snd_nxt, tp->snd_una)) {
10406 		tp->snd_nxt = tp->snd_una;
10407 	}
10408 	if (under_pacing &&
10409 	    (rack->use_fixed_rate == 0) &&
10410 	    (rack->in_probe_rtt == 0) &&
10411 	    rack->rc_gp_dyn_mul &&
10412 	    rack->rc_always_pace) {
10413 		/* Check if we are dragging bottom */
10414 		rack_check_bottom_drag(tp, rack, so, acked);
10415 	}
10416 	if (tp->snd_una == tp->snd_max) {
10417 		/* Nothing left outstanding */
10418 		tp->t_flags &= ~TF_PREVVALID;
10419 		rack->r_ctl.rc_went_idle_time = tcp_get_usecs(NULL);
10420 		rack->r_ctl.retran_during_recovery = 0;
10421 		rack->r_ctl.dsack_byte_cnt = 0;
10422 		if (rack->r_ctl.rc_went_idle_time == 0)
10423 			rack->r_ctl.rc_went_idle_time = 1;
10424 		rack_log_progress_event(rack, tp, 0, PROGRESS_CLEAR, __LINE__);
10425 		if (sbavail(&tp->t_inpcb->inp_socket->so_snd) == 0)
10426 			tp->t_acktime = 0;
10427 		rack_timer_cancel(tp, rack, rack->r_ctl.rc_rcvtime, __LINE__);
10428 		/* Set need output so persist might get set */
10429 		rack->r_wanted_output = 1;
10430 		sack_filter_clear(&rack->r_ctl.rack_sf, tp->snd_una);
10431 		if ((tp->t_state >= TCPS_FIN_WAIT_1) &&
10432 		    (sbavail(&so->so_snd) == 0) &&
10433 		    (tp->t_flags2 & TF2_DROP_AF_DATA)) {
10434 			/*
10435 			 * The socket was gone and the
10436 			 * peer sent data (now or in the past), time to
10437 			 * reset him.
10438 			 */
10439 			*ret_val = 1;
10440 			/* tcp_close will kill the inp pre-log the Reset */
10441 			tcp_log_end_status(tp, TCP_EI_STATUS_SERVER_RST);
10442 			tp = tcp_close(tp);
10443 			ctf_do_dropwithreset(m, tp, th, BANDLIM_UNLIMITED, tlen);
10444 			return (1);
10445 		}
10446 	}
10447 	if (ofia)
10448 		*ofia = ourfinisacked;
10449 	return (0);
10450 }
10451 
10452 static void
10453 rack_collapsed_window(struct tcp_rack *rack)
10454 {
10455 	/*
10456 	 * Now we must walk the
10457 	 * send map and divide the
10458 	 * ones left stranded. These
10459 	 * guys can't cause us to abort
10460 	 * the connection and are really
10461 	 * "unsent". However if a buggy
10462 	 * client actually did keep some
10463 	 * of the data i.e. collapsed the win
10464 	 * and refused to ack and then opened
10465 	 * the win and acked that data. We would
10466 	 * get into an ack war, the simplier
10467 	 * method then of just pretending we
10468 	 * did not send those segments something
10469 	 * won't work.
10470 	 */
10471 	struct rack_sendmap *rsm, *nrsm, fe, *insret;
10472 	tcp_seq max_seq;
10473 
10474 	max_seq = rack->rc_tp->snd_una + rack->rc_tp->snd_wnd;
10475 	memset(&fe, 0, sizeof(fe));
10476 	fe.r_start = max_seq;
10477 	/* Find the first seq past or at maxseq */
10478 	rsm = RB_FIND(rack_rb_tree_head, &rack->r_ctl.rc_mtree, &fe);
10479 	if (rsm == NULL) {
10480 		/* Nothing to do strange */
10481 		rack->rc_has_collapsed = 0;
10482 		return;
10483 	}
10484 	/*
10485 	 * Now do we need to split at
10486 	 * the collapse point?
10487 	 */
10488 	if (SEQ_GT(max_seq, rsm->r_start)) {
10489 		nrsm = rack_alloc_limit(rack, RACK_LIMIT_TYPE_SPLIT);
10490 		if (nrsm == NULL) {
10491 			/* We can't get a rsm, mark all? */
10492 			nrsm = rsm;
10493 			goto no_split;
10494 		}
10495 		/* Clone it */
10496 		rack_clone_rsm(rack, nrsm, rsm, max_seq);
10497 		insret = RB_INSERT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, nrsm);
10498 #ifdef INVARIANTS
10499 		if (insret != NULL) {
10500 			panic("Insert in rb tree of %p fails ret:%p rack:%p rsm:%p",
10501 			      nrsm, insret, rack, rsm);
10502 		}
10503 #endif
10504 		rack_log_map_chg(rack->rc_tp, rack, NULL, rsm, nrsm, MAP_SPLIT, max_seq, __LINE__);
10505 		if (rsm->r_in_tmap) {
10506 			TAILQ_INSERT_AFTER(&rack->r_ctl.rc_tmap, rsm, nrsm, r_tnext);
10507 			nrsm->r_in_tmap = 1;
10508 		}
10509 		/*
10510 		 * Set in the new RSM as the
10511 		 * collapsed starting point
10512 		 */
10513 		rsm = nrsm;
10514 	}
10515 no_split:
10516 	counter_u64_add(rack_collapsed_win, 1);
10517 	RB_FOREACH_FROM(nrsm, rack_rb_tree_head, rsm) {
10518 		nrsm->r_flags |= RACK_RWND_COLLAPSED;
10519 	}
10520 	rack->rc_has_collapsed = 1;
10521 }
10522 
10523 static void
10524 rack_un_collapse_window(struct tcp_rack *rack)
10525 {
10526 	struct rack_sendmap *rsm;
10527 
10528 	RB_FOREACH_REVERSE(rsm, rack_rb_tree_head, &rack->r_ctl.rc_mtree) {
10529 		if (rsm->r_flags & RACK_RWND_COLLAPSED)
10530 			rsm->r_flags &= ~RACK_RWND_COLLAPSED;
10531 		else
10532 			break;
10533 	}
10534 	rack->rc_has_collapsed = 0;
10535 }
10536 
10537 static void
10538 rack_handle_delayed_ack(struct tcpcb *tp, struct tcp_rack *rack,
10539 			int32_t tlen, int32_t tfo_syn)
10540 {
10541 	if (DELAY_ACK(tp, tlen) || tfo_syn) {
10542 		if (rack->rc_dack_mode &&
10543 		    (tlen > 500) &&
10544 		    (rack->rc_dack_toggle == 1)) {
10545 			goto no_delayed_ack;
10546 		}
10547 		rack_timer_cancel(tp, rack,
10548 				  rack->r_ctl.rc_rcvtime, __LINE__);
10549 		tp->t_flags |= TF_DELACK;
10550 	} else {
10551 no_delayed_ack:
10552 		rack->r_wanted_output = 1;
10553 		tp->t_flags |= TF_ACKNOW;
10554 		if (rack->rc_dack_mode) {
10555 			if (tp->t_flags & TF_DELACK)
10556 				rack->rc_dack_toggle = 1;
10557 			else
10558 				rack->rc_dack_toggle = 0;
10559 		}
10560 	}
10561 }
10562 
10563 static void
10564 rack_validate_fo_sendwin_up(struct tcpcb *tp, struct tcp_rack *rack)
10565 {
10566 	/*
10567 	 * If fast output is in progress, lets validate that
10568 	 * the new window did not shrink on us and make it
10569 	 * so fast output should end.
10570 	 */
10571 	if (rack->r_fast_output) {
10572 		uint32_t out;
10573 
10574 		/*
10575 		 * Calculate what we will send if left as is
10576 		 * and compare that to our send window.
10577 		 */
10578 		out = ctf_outstanding(tp);
10579 		if ((out + rack->r_ctl.fsb.left_to_send) > tp->snd_wnd) {
10580 			/* ok we have an issue */
10581 			if (out >= tp->snd_wnd) {
10582 				/* Turn off fast output the window is met or collapsed */
10583 				rack->r_fast_output = 0;
10584 			} else {
10585 				/* we have some room left */
10586 				rack->r_ctl.fsb.left_to_send = tp->snd_wnd - out;
10587 				if (rack->r_ctl.fsb.left_to_send < ctf_fixed_maxseg(tp)) {
10588 					/* If not at least 1 full segment never mind */
10589 					rack->r_fast_output = 0;
10590 				}
10591 			}
10592 		}
10593 	}
10594 }
10595 
10596 
10597 /*
10598  * Return value of 1, the TCB is unlocked and most
10599  * likely gone, return value of 0, the TCP is still
10600  * locked.
10601  */
10602 static int
10603 rack_process_data(struct mbuf *m, struct tcphdr *th, struct socket *so,
10604     struct tcpcb *tp, int32_t drop_hdrlen, int32_t tlen,
10605     uint32_t tiwin, int32_t thflags, int32_t nxt_pkt)
10606 {
10607 	/*
10608 	 * Update window information. Don't look at window if no ACK: TAC's
10609 	 * send garbage on first SYN.
10610 	 */
10611 	int32_t nsegs;
10612 	int32_t tfo_syn;
10613 	struct tcp_rack *rack;
10614 
10615 	rack = (struct tcp_rack *)tp->t_fb_ptr;
10616 	INP_WLOCK_ASSERT(tp->t_inpcb);
10617 	nsegs = max(1, m->m_pkthdr.lro_nsegs);
10618 	if ((thflags & TH_ACK) &&
10619 	    (SEQ_LT(tp->snd_wl1, th->th_seq) ||
10620 	    (tp->snd_wl1 == th->th_seq && (SEQ_LT(tp->snd_wl2, th->th_ack) ||
10621 	    (tp->snd_wl2 == th->th_ack && tiwin > tp->snd_wnd))))) {
10622 		/* keep track of pure window updates */
10623 		if (tlen == 0 &&
10624 		    tp->snd_wl2 == th->th_ack && tiwin > tp->snd_wnd)
10625 			KMOD_TCPSTAT_INC(tcps_rcvwinupd);
10626 		tp->snd_wnd = tiwin;
10627 		rack_validate_fo_sendwin_up(tp, rack);
10628 		tp->snd_wl1 = th->th_seq;
10629 		tp->snd_wl2 = th->th_ack;
10630 		if (tp->snd_wnd > tp->max_sndwnd)
10631 			tp->max_sndwnd = tp->snd_wnd;
10632 		rack->r_wanted_output = 1;
10633 	} else if (thflags & TH_ACK) {
10634 		if ((tp->snd_wl2 == th->th_ack) && (tiwin < tp->snd_wnd)) {
10635 			tp->snd_wnd = tiwin;
10636 			rack_validate_fo_sendwin_up(tp, rack);
10637 			tp->snd_wl1 = th->th_seq;
10638 			tp->snd_wl2 = th->th_ack;
10639 		}
10640 	}
10641 	if (tp->snd_wnd < ctf_outstanding(tp))
10642 		/* The peer collapsed the window */
10643 		rack_collapsed_window(rack);
10644 	else if (rack->rc_has_collapsed)
10645 		rack_un_collapse_window(rack);
10646 	/* Was persist timer active and now we have window space? */
10647 	if ((rack->rc_in_persist != 0) &&
10648 	    (tp->snd_wnd >= min((rack->r_ctl.rc_high_rwnd/2),
10649 				rack->r_ctl.rc_pace_min_segs))) {
10650 		rack_exit_persist(tp, rack, rack->r_ctl.rc_rcvtime);
10651 		tp->snd_nxt = tp->snd_max;
10652 		/* Make sure we output to start the timer */
10653 		rack->r_wanted_output = 1;
10654 	}
10655 	/* Do we enter persists? */
10656 	if ((rack->rc_in_persist == 0) &&
10657 	    (tp->snd_wnd < min((rack->r_ctl.rc_high_rwnd/2), rack->r_ctl.rc_pace_min_segs)) &&
10658 	    TCPS_HAVEESTABLISHED(tp->t_state) &&
10659 	    (tp->snd_max == tp->snd_una) &&
10660 	    sbavail(&tp->t_inpcb->inp_socket->so_snd) &&
10661 	    (sbavail(&tp->t_inpcb->inp_socket->so_snd) > tp->snd_wnd)) {
10662 		/*
10663 		 * Here the rwnd is less than
10664 		 * the pacing size, we are established,
10665 		 * nothing is outstanding, and there is
10666 		 * data to send. Enter persists.
10667 		 */
10668 		rack_enter_persist(tp, rack, rack->r_ctl.rc_rcvtime);
10669 	}
10670 	if (tp->t_flags2 & TF2_DROP_AF_DATA) {
10671 		m_freem(m);
10672 		return (0);
10673 	}
10674 	/*
10675 	 * don't process the URG bit, ignore them drag
10676 	 * along the up.
10677 	 */
10678 	tp->rcv_up = tp->rcv_nxt;
10679 	INP_WLOCK_ASSERT(tp->t_inpcb);
10680 
10681 	/*
10682 	 * Process the segment text, merging it into the TCP sequencing
10683 	 * queue, and arranging for acknowledgment of receipt if necessary.
10684 	 * This process logically involves adjusting tp->rcv_wnd as data is
10685 	 * presented to the user (this happens in tcp_usrreq.c, case
10686 	 * PRU_RCVD).  If a FIN has already been received on this connection
10687 	 * then we just ignore the text.
10688 	 */
10689 	tfo_syn = ((tp->t_state == TCPS_SYN_RECEIVED) &&
10690 		   IS_FASTOPEN(tp->t_flags));
10691 	if ((tlen || (thflags & TH_FIN) || (tfo_syn && tlen > 0)) &&
10692 	    TCPS_HAVERCVDFIN(tp->t_state) == 0) {
10693 		tcp_seq save_start = th->th_seq;
10694 		tcp_seq save_rnxt  = tp->rcv_nxt;
10695 		int     save_tlen  = tlen;
10696 
10697 		m_adj(m, drop_hdrlen);	/* delayed header drop */
10698 		/*
10699 		 * Insert segment which includes th into TCP reassembly
10700 		 * queue with control block tp.  Set thflags to whether
10701 		 * reassembly now includes a segment with FIN.  This handles
10702 		 * the common case inline (segment is the next to be
10703 		 * received on an established connection, and the queue is
10704 		 * empty), avoiding linkage into and removal from the queue
10705 		 * and repetition of various conversions. Set DELACK for
10706 		 * segments received in order, but ack immediately when
10707 		 * segments are out of order (so fast retransmit can work).
10708 		 */
10709 		if (th->th_seq == tp->rcv_nxt &&
10710 		    SEGQ_EMPTY(tp) &&
10711 		    (TCPS_HAVEESTABLISHED(tp->t_state) ||
10712 		    tfo_syn)) {
10713 #ifdef NETFLIX_SB_LIMITS
10714 			u_int mcnt, appended;
10715 
10716 			if (so->so_rcv.sb_shlim) {
10717 				mcnt = m_memcnt(m);
10718 				appended = 0;
10719 				if (counter_fo_get(so->so_rcv.sb_shlim, mcnt,
10720 				    CFO_NOSLEEP, NULL) == false) {
10721 					counter_u64_add(tcp_sb_shlim_fails, 1);
10722 					m_freem(m);
10723 					return (0);
10724 				}
10725 			}
10726 #endif
10727 			rack_handle_delayed_ack(tp, rack, tlen, tfo_syn);
10728 			tp->rcv_nxt += tlen;
10729 			if (tlen &&
10730 			    ((tp->t_flags2 & TF2_FBYTES_COMPLETE) == 0) &&
10731 			    (tp->t_fbyte_in == 0)) {
10732 				tp->t_fbyte_in = ticks;
10733 				if (tp->t_fbyte_in == 0)
10734 					tp->t_fbyte_in = 1;
10735 				if (tp->t_fbyte_out && tp->t_fbyte_in)
10736 					tp->t_flags2 |= TF2_FBYTES_COMPLETE;
10737 			}
10738 			thflags = th->th_flags & TH_FIN;
10739 			KMOD_TCPSTAT_ADD(tcps_rcvpack, nsegs);
10740 			KMOD_TCPSTAT_ADD(tcps_rcvbyte, tlen);
10741 			SOCKBUF_LOCK(&so->so_rcv);
10742 			if (so->so_rcv.sb_state & SBS_CANTRCVMORE) {
10743 				m_freem(m);
10744 			} else
10745 #ifdef NETFLIX_SB_LIMITS
10746 				appended =
10747 #endif
10748 					sbappendstream_locked(&so->so_rcv, m, 0);
10749 
10750 			rack_log_wakeup(tp,rack, &so->so_rcv, tlen, 1);
10751 			/* NB: sorwakeup_locked() does an implicit unlock. */
10752 			sorwakeup_locked(so);
10753 #ifdef NETFLIX_SB_LIMITS
10754 			if (so->so_rcv.sb_shlim && appended != mcnt)
10755 				counter_fo_release(so->so_rcv.sb_shlim,
10756 				    mcnt - appended);
10757 #endif
10758 		} else {
10759 			/*
10760 			 * XXX: Due to the header drop above "th" is
10761 			 * theoretically invalid by now.  Fortunately
10762 			 * m_adj() doesn't actually frees any mbufs when
10763 			 * trimming from the head.
10764 			 */
10765 			tcp_seq temp = save_start;
10766 
10767 			thflags = tcp_reass(tp, th, &temp, &tlen, m);
10768 			tp->t_flags |= TF_ACKNOW;
10769 			if (tp->t_flags & TF_WAKESOR) {
10770 				tp->t_flags &= ~TF_WAKESOR;
10771 				/* NB: sorwakeup_locked() does an implicit unlock. */
10772 				sorwakeup_locked(so);
10773 			}
10774 		}
10775 		if ((tp->t_flags & TF_SACK_PERMIT) &&
10776 		    (save_tlen > 0) &&
10777 		    TCPS_HAVEESTABLISHED(tp->t_state)) {
10778 			if ((tlen == 0) && (SEQ_LT(save_start, save_rnxt))) {
10779 				/*
10780 				 * DSACK actually handled in the fastpath
10781 				 * above.
10782 				 */
10783 				RACK_OPTS_INC(tcp_sack_path_1);
10784 				tcp_update_sack_list(tp, save_start,
10785 				    save_start + save_tlen);
10786 			} else if ((tlen > 0) && SEQ_GT(tp->rcv_nxt, save_rnxt)) {
10787 				if ((tp->rcv_numsacks >= 1) &&
10788 				    (tp->sackblks[0].end == save_start)) {
10789 					/*
10790 					 * Partial overlap, recorded at todrop
10791 					 * above.
10792 					 */
10793 					RACK_OPTS_INC(tcp_sack_path_2a);
10794 					tcp_update_sack_list(tp,
10795 					    tp->sackblks[0].start,
10796 					    tp->sackblks[0].end);
10797 				} else {
10798 					RACK_OPTS_INC(tcp_sack_path_2b);
10799 					tcp_update_dsack_list(tp, save_start,
10800 					    save_start + save_tlen);
10801 				}
10802 			} else if (tlen >= save_tlen) {
10803 				/* Update of sackblks. */
10804 				RACK_OPTS_INC(tcp_sack_path_3);
10805 				tcp_update_dsack_list(tp, save_start,
10806 				    save_start + save_tlen);
10807 			} else if (tlen > 0) {
10808 				RACK_OPTS_INC(tcp_sack_path_4);
10809 				tcp_update_dsack_list(tp, save_start,
10810 				    save_start + tlen);
10811 			}
10812 		}
10813 	} else {
10814 		m_freem(m);
10815 		thflags &= ~TH_FIN;
10816 	}
10817 
10818 	/*
10819 	 * If FIN is received ACK the FIN and let the user know that the
10820 	 * connection is closing.
10821 	 */
10822 	if (thflags & TH_FIN) {
10823 		if (TCPS_HAVERCVDFIN(tp->t_state) == 0) {
10824 			/* The socket upcall is handled by socantrcvmore. */
10825 			socantrcvmore(so);
10826 			/*
10827 			 * If connection is half-synchronized (ie NEEDSYN
10828 			 * flag on) then delay ACK, so it may be piggybacked
10829 			 * when SYN is sent. Otherwise, since we received a
10830 			 * FIN then no more input can be expected, send ACK
10831 			 * now.
10832 			 */
10833 			if (tp->t_flags & TF_NEEDSYN) {
10834 				rack_timer_cancel(tp, rack,
10835 				    rack->r_ctl.rc_rcvtime, __LINE__);
10836 				tp->t_flags |= TF_DELACK;
10837 			} else {
10838 				tp->t_flags |= TF_ACKNOW;
10839 			}
10840 			tp->rcv_nxt++;
10841 		}
10842 		switch (tp->t_state) {
10843 			/*
10844 			 * In SYN_RECEIVED and ESTABLISHED STATES enter the
10845 			 * CLOSE_WAIT state.
10846 			 */
10847 		case TCPS_SYN_RECEIVED:
10848 			tp->t_starttime = ticks;
10849 			/* FALLTHROUGH */
10850 		case TCPS_ESTABLISHED:
10851 			rack_timer_cancel(tp, rack,
10852 			    rack->r_ctl.rc_rcvtime, __LINE__);
10853 			tcp_state_change(tp, TCPS_CLOSE_WAIT);
10854 			break;
10855 
10856 			/*
10857 			 * If still in FIN_WAIT_1 STATE FIN has not been
10858 			 * acked so enter the CLOSING state.
10859 			 */
10860 		case TCPS_FIN_WAIT_1:
10861 			rack_timer_cancel(tp, rack,
10862 			    rack->r_ctl.rc_rcvtime, __LINE__);
10863 			tcp_state_change(tp, TCPS_CLOSING);
10864 			break;
10865 
10866 			/*
10867 			 * In FIN_WAIT_2 state enter the TIME_WAIT state,
10868 			 * starting the time-wait timer, turning off the
10869 			 * other standard timers.
10870 			 */
10871 		case TCPS_FIN_WAIT_2:
10872 			rack_timer_cancel(tp, rack,
10873 			    rack->r_ctl.rc_rcvtime, __LINE__);
10874 			tcp_twstart(tp);
10875 			return (1);
10876 		}
10877 	}
10878 	/*
10879 	 * Return any desired output.
10880 	 */
10881 	if ((tp->t_flags & TF_ACKNOW) ||
10882 	    (sbavail(&so->so_snd) > (tp->snd_max - tp->snd_una))) {
10883 		rack->r_wanted_output = 1;
10884 	}
10885 	INP_WLOCK_ASSERT(tp->t_inpcb);
10886 	return (0);
10887 }
10888 
10889 /*
10890  * Here nothing is really faster, its just that we
10891  * have broken out the fast-data path also just like
10892  * the fast-ack.
10893  */
10894 static int
10895 rack_do_fastnewdata(struct mbuf *m, struct tcphdr *th, struct socket *so,
10896     struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen,
10897     uint32_t tiwin, int32_t nxt_pkt, uint8_t iptos)
10898 {
10899 	int32_t nsegs;
10900 	int32_t newsize = 0;	/* automatic sockbuf scaling */
10901 	struct tcp_rack *rack;
10902 #ifdef NETFLIX_SB_LIMITS
10903 	u_int mcnt, appended;
10904 #endif
10905 #ifdef TCPDEBUG
10906 	/*
10907 	 * The size of tcp_saveipgen must be the size of the max ip header,
10908 	 * now IPv6.
10909 	 */
10910 	u_char tcp_saveipgen[IP6_HDR_LEN];
10911 	struct tcphdr tcp_savetcp;
10912 	short ostate = 0;
10913 
10914 #endif
10915 	/*
10916 	 * If last ACK falls within this segment's sequence numbers, record
10917 	 * the timestamp. NOTE that the test is modified according to the
10918 	 * latest proposal of the tcplw@cray.com list (Braden 1993/04/26).
10919 	 */
10920 	if (__predict_false(th->th_seq != tp->rcv_nxt)) {
10921 		return (0);
10922 	}
10923 	if (__predict_false(tp->snd_nxt != tp->snd_max)) {
10924 		return (0);
10925 	}
10926 	if (tiwin && tiwin != tp->snd_wnd) {
10927 		return (0);
10928 	}
10929 	if (__predict_false((tp->t_flags & (TF_NEEDSYN | TF_NEEDFIN)))) {
10930 		return (0);
10931 	}
10932 	if (__predict_false((to->to_flags & TOF_TS) &&
10933 	    (TSTMP_LT(to->to_tsval, tp->ts_recent)))) {
10934 		return (0);
10935 	}
10936 	if (__predict_false((th->th_ack != tp->snd_una))) {
10937 		return (0);
10938 	}
10939 	if (__predict_false(tlen > sbspace(&so->so_rcv))) {
10940 		return (0);
10941 	}
10942 	if ((to->to_flags & TOF_TS) != 0 &&
10943 	    SEQ_LEQ(th->th_seq, tp->last_ack_sent)) {
10944 		tp->ts_recent_age = tcp_ts_getticks();
10945 		tp->ts_recent = to->to_tsval;
10946 	}
10947 	rack = (struct tcp_rack *)tp->t_fb_ptr;
10948 	/*
10949 	 * This is a pure, in-sequence data packet with nothing on the
10950 	 * reassembly queue and we have enough buffer space to take it.
10951 	 */
10952 	nsegs = max(1, m->m_pkthdr.lro_nsegs);
10953 
10954 #ifdef NETFLIX_SB_LIMITS
10955 	if (so->so_rcv.sb_shlim) {
10956 		mcnt = m_memcnt(m);
10957 		appended = 0;
10958 		if (counter_fo_get(so->so_rcv.sb_shlim, mcnt,
10959 		    CFO_NOSLEEP, NULL) == false) {
10960 			counter_u64_add(tcp_sb_shlim_fails, 1);
10961 			m_freem(m);
10962 			return (1);
10963 		}
10964 	}
10965 #endif
10966 	/* Clean receiver SACK report if present */
10967 	if (tp->rcv_numsacks)
10968 		tcp_clean_sackreport(tp);
10969 	KMOD_TCPSTAT_INC(tcps_preddat);
10970 	tp->rcv_nxt += tlen;
10971 	if (tlen &&
10972 	    ((tp->t_flags2 & TF2_FBYTES_COMPLETE) == 0) &&
10973 	    (tp->t_fbyte_in == 0)) {
10974 		tp->t_fbyte_in = ticks;
10975 		if (tp->t_fbyte_in == 0)
10976 			tp->t_fbyte_in = 1;
10977 		if (tp->t_fbyte_out && tp->t_fbyte_in)
10978 			tp->t_flags2 |= TF2_FBYTES_COMPLETE;
10979 	}
10980 	/*
10981 	 * Pull snd_wl1 up to prevent seq wrap relative to th_seq.
10982 	 */
10983 	tp->snd_wl1 = th->th_seq;
10984 	/*
10985 	 * Pull rcv_up up to prevent seq wrap relative to rcv_nxt.
10986 	 */
10987 	tp->rcv_up = tp->rcv_nxt;
10988 	KMOD_TCPSTAT_ADD(tcps_rcvpack, nsegs);
10989 	KMOD_TCPSTAT_ADD(tcps_rcvbyte, tlen);
10990 #ifdef TCPDEBUG
10991 	if (so->so_options & SO_DEBUG)
10992 		tcp_trace(TA_INPUT, ostate, tp,
10993 		    (void *)tcp_saveipgen, &tcp_savetcp, 0);
10994 #endif
10995 	newsize = tcp_autorcvbuf(m, th, so, tp, tlen);
10996 
10997 	/* Add data to socket buffer. */
10998 	SOCKBUF_LOCK(&so->so_rcv);
10999 	if (so->so_rcv.sb_state & SBS_CANTRCVMORE) {
11000 		m_freem(m);
11001 	} else {
11002 		/*
11003 		 * Set new socket buffer size. Give up when limit is
11004 		 * reached.
11005 		 */
11006 		if (newsize)
11007 			if (!sbreserve_locked(&so->so_rcv,
11008 			    newsize, so, NULL))
11009 				so->so_rcv.sb_flags &= ~SB_AUTOSIZE;
11010 		m_adj(m, drop_hdrlen);	/* delayed header drop */
11011 #ifdef NETFLIX_SB_LIMITS
11012 		appended =
11013 #endif
11014 			sbappendstream_locked(&so->so_rcv, m, 0);
11015 		ctf_calc_rwin(so, tp);
11016 	}
11017 	rack_log_wakeup(tp,rack, &so->so_rcv, tlen, 1);
11018 	/* NB: sorwakeup_locked() does an implicit unlock. */
11019 	sorwakeup_locked(so);
11020 #ifdef NETFLIX_SB_LIMITS
11021 	if (so->so_rcv.sb_shlim && mcnt != appended)
11022 		counter_fo_release(so->so_rcv.sb_shlim, mcnt - appended);
11023 #endif
11024 	rack_handle_delayed_ack(tp, rack, tlen, 0);
11025 	if (tp->snd_una == tp->snd_max)
11026 		sack_filter_clear(&rack->r_ctl.rack_sf, tp->snd_una);
11027 	return (1);
11028 }
11029 
11030 /*
11031  * This subfunction is used to try to highly optimize the
11032  * fast path. We again allow window updates that are
11033  * in sequence to remain in the fast-path. We also add
11034  * in the __predict's to attempt to help the compiler.
11035  * Note that if we return a 0, then we can *not* process
11036  * it and the caller should push the packet into the
11037  * slow-path.
11038  */
11039 static int
11040 rack_fastack(struct mbuf *m, struct tcphdr *th, struct socket *so,
11041     struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen,
11042     uint32_t tiwin, int32_t nxt_pkt, uint32_t cts)
11043 {
11044 	int32_t acked;
11045 	int32_t nsegs;
11046 #ifdef TCPDEBUG
11047 	/*
11048 	 * The size of tcp_saveipgen must be the size of the max ip header,
11049 	 * now IPv6.
11050 	 */
11051 	u_char tcp_saveipgen[IP6_HDR_LEN];
11052 	struct tcphdr tcp_savetcp;
11053 	short ostate = 0;
11054 #endif
11055 	int32_t under_pacing = 0;
11056 	struct tcp_rack *rack;
11057 
11058 	if (__predict_false(SEQ_LEQ(th->th_ack, tp->snd_una))) {
11059 		/* Old ack, behind (or duplicate to) the last one rcv'd */
11060 		return (0);
11061 	}
11062 	if (__predict_false(SEQ_GT(th->th_ack, tp->snd_max))) {
11063 		/* Above what we have sent? */
11064 		return (0);
11065 	}
11066 	if (__predict_false(tp->snd_nxt != tp->snd_max)) {
11067 		/* We are retransmitting */
11068 		return (0);
11069 	}
11070 	if (__predict_false(tiwin == 0)) {
11071 		/* zero window */
11072 		return (0);
11073 	}
11074 	if (__predict_false(tp->t_flags & (TF_NEEDSYN | TF_NEEDFIN))) {
11075 		/* We need a SYN or a FIN, unlikely.. */
11076 		return (0);
11077 	}
11078 	if ((to->to_flags & TOF_TS) && __predict_false(TSTMP_LT(to->to_tsval, tp->ts_recent))) {
11079 		/* Timestamp is behind .. old ack with seq wrap? */
11080 		return (0);
11081 	}
11082 	if (__predict_false(IN_RECOVERY(tp->t_flags))) {
11083 		/* Still recovering */
11084 		return (0);
11085 	}
11086 	rack = (struct tcp_rack *)tp->t_fb_ptr;
11087 	if (rack->r_ctl.rc_sacked) {
11088 		/* We have sack holes on our scoreboard */
11089 		return (0);
11090 	}
11091 	/* Ok if we reach here, we can process a fast-ack */
11092 	if (rack->gp_ready &&
11093 	    (rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT)) {
11094 		under_pacing = 1;
11095 	}
11096 	nsegs = max(1, m->m_pkthdr.lro_nsegs);
11097 	rack_log_ack(tp, to, th, 0, 0);
11098 	/* Did the window get updated? */
11099 	if (tiwin != tp->snd_wnd) {
11100 		tp->snd_wnd = tiwin;
11101 		rack_validate_fo_sendwin_up(tp, rack);
11102 		tp->snd_wl1 = th->th_seq;
11103 		if (tp->snd_wnd > tp->max_sndwnd)
11104 			tp->max_sndwnd = tp->snd_wnd;
11105 	}
11106 	/* Do we exit persists? */
11107 	if ((rack->rc_in_persist != 0) &&
11108 	    (tp->snd_wnd >= min((rack->r_ctl.rc_high_rwnd/2),
11109 			       rack->r_ctl.rc_pace_min_segs))) {
11110 		rack_exit_persist(tp, rack, cts);
11111 	}
11112 	/* Do we enter persists? */
11113 	if ((rack->rc_in_persist == 0) &&
11114 	    (tp->snd_wnd < min((rack->r_ctl.rc_high_rwnd/2), rack->r_ctl.rc_pace_min_segs)) &&
11115 	    TCPS_HAVEESTABLISHED(tp->t_state) &&
11116 	    (tp->snd_max == tp->snd_una) &&
11117 	    sbavail(&tp->t_inpcb->inp_socket->so_snd) &&
11118 	    (sbavail(&tp->t_inpcb->inp_socket->so_snd) > tp->snd_wnd)) {
11119 		/*
11120 		 * Here the rwnd is less than
11121 		 * the pacing size, we are established,
11122 		 * nothing is outstanding, and there is
11123 		 * data to send. Enter persists.
11124 		 */
11125 		rack_enter_persist(tp, rack, rack->r_ctl.rc_rcvtime);
11126 	}
11127 	/*
11128 	 * If last ACK falls within this segment's sequence numbers, record
11129 	 * the timestamp. NOTE that the test is modified according to the
11130 	 * latest proposal of the tcplw@cray.com list (Braden 1993/04/26).
11131 	 */
11132 	if ((to->to_flags & TOF_TS) != 0 &&
11133 	    SEQ_LEQ(th->th_seq, tp->last_ack_sent)) {
11134 		tp->ts_recent_age = tcp_ts_getticks();
11135 		tp->ts_recent = to->to_tsval;
11136 	}
11137 	/*
11138 	 * This is a pure ack for outstanding data.
11139 	 */
11140 	KMOD_TCPSTAT_INC(tcps_predack);
11141 
11142 	/*
11143 	 * "bad retransmit" recovery.
11144 	 */
11145 	if ((tp->t_flags & TF_PREVVALID) &&
11146 	    ((tp->t_flags & TF_RCVD_TSTMP) == 0)) {
11147 		tp->t_flags &= ~TF_PREVVALID;
11148 		if (tp->t_rxtshift == 1 &&
11149 		    (int)(ticks - tp->t_badrxtwin) < 0)
11150 			rack_cong_signal(tp, CC_RTO_ERR, th->th_ack);
11151 	}
11152 	/*
11153 	 * Recalculate the transmit timer / rtt.
11154 	 *
11155 	 * Some boxes send broken timestamp replies during the SYN+ACK
11156 	 * phase, ignore timestamps of 0 or we could calculate a huge RTT
11157 	 * and blow up the retransmit timer.
11158 	 */
11159 	acked = BYTES_THIS_ACK(tp, th);
11160 
11161 #ifdef TCP_HHOOK
11162 	/* Run HHOOK_TCP_ESTABLISHED_IN helper hooks. */
11163 	hhook_run_tcp_est_in(tp, th, to);
11164 #endif
11165 	KMOD_TCPSTAT_ADD(tcps_rcvackpack, nsegs);
11166 	KMOD_TCPSTAT_ADD(tcps_rcvackbyte, acked);
11167 	if (acked) {
11168 		struct mbuf *mfree;
11169 
11170 		rack_ack_received(tp, rack, th->th_ack, nsegs, CC_ACK, 0);
11171 		SOCKBUF_LOCK(&so->so_snd);
11172 		mfree = sbcut_locked(&so->so_snd, acked);
11173 		tp->snd_una = th->th_ack;
11174 		/* Note we want to hold the sb lock through the sendmap adjust */
11175 		rack_adjust_sendmap(rack, &so->so_snd, tp->snd_una);
11176 		/* Wake up the socket if we have room to write more */
11177 		rack_log_wakeup(tp,rack, &so->so_snd, acked, 2);
11178 		sowwakeup_locked(so);
11179 		m_freem(mfree);
11180 		tp->t_rxtshift = 0;
11181 		RACK_TCPT_RANGESET(tp->t_rxtcur, RACK_REXMTVAL(tp),
11182 			      rack_rto_min, rack_rto_max, rack->r_ctl.timer_slop);
11183 		rack->rc_tlp_in_progress = 0;
11184 		rack->r_ctl.rc_tlp_cnt_out = 0;
11185 		/*
11186 		 * If it is the RXT timer we want to
11187 		 * stop it, so we can restart a TLP.
11188 		 */
11189 		if (rack->r_ctl.rc_hpts_flags & PACE_TMR_RXT)
11190 			rack_timer_cancel(tp, rack, rack->r_ctl.rc_rcvtime, __LINE__);
11191 #ifdef NETFLIX_HTTP_LOGGING
11192 		tcp_http_check_for_comp(rack->rc_tp, th->th_ack);
11193 #endif
11194 	}
11195 	/*
11196 	 * Let the congestion control algorithm update congestion control
11197 	 * related information. This typically means increasing the
11198 	 * congestion window.
11199 	 */
11200 	if (tp->snd_wnd < ctf_outstanding(tp)) {
11201 		/* The peer collapsed the window */
11202 		rack_collapsed_window(rack);
11203 	} else if (rack->rc_has_collapsed)
11204 		rack_un_collapse_window(rack);
11205 
11206 	/*
11207 	 * Pull snd_wl2 up to prevent seq wrap relative to th_ack.
11208 	 */
11209 	tp->snd_wl2 = th->th_ack;
11210 	tp->t_dupacks = 0;
11211 	m_freem(m);
11212 	/* ND6_HINT(tp);	 *//* Some progress has been made. */
11213 
11214 	/*
11215 	 * If all outstanding data are acked, stop retransmit timer,
11216 	 * otherwise restart timer using current (possibly backed-off)
11217 	 * value. If process is waiting for space, wakeup/selwakeup/signal.
11218 	 * If data are ready to send, let tcp_output decide between more
11219 	 * output or persist.
11220 	 */
11221 #ifdef TCPDEBUG
11222 	if (so->so_options & SO_DEBUG)
11223 		tcp_trace(TA_INPUT, ostate, tp,
11224 		    (void *)tcp_saveipgen,
11225 		    &tcp_savetcp, 0);
11226 #endif
11227 	if (under_pacing &&
11228 	    (rack->use_fixed_rate == 0) &&
11229 	    (rack->in_probe_rtt == 0) &&
11230 	    rack->rc_gp_dyn_mul &&
11231 	    rack->rc_always_pace) {
11232 		/* Check if we are dragging bottom */
11233 		rack_check_bottom_drag(tp, rack, so, acked);
11234 	}
11235 	if (tp->snd_una == tp->snd_max) {
11236 		tp->t_flags &= ~TF_PREVVALID;
11237 		rack->r_ctl.retran_during_recovery = 0;
11238 		rack->r_ctl.dsack_byte_cnt = 0;
11239 		rack->r_ctl.rc_went_idle_time = tcp_get_usecs(NULL);
11240 		if (rack->r_ctl.rc_went_idle_time == 0)
11241 			rack->r_ctl.rc_went_idle_time = 1;
11242 		rack_log_progress_event(rack, tp, 0, PROGRESS_CLEAR, __LINE__);
11243 		if (sbavail(&tp->t_inpcb->inp_socket->so_snd) == 0)
11244 			tp->t_acktime = 0;
11245 		rack_timer_cancel(tp, rack, rack->r_ctl.rc_rcvtime, __LINE__);
11246 	}
11247 	if (acked && rack->r_fast_output)
11248 		rack_gain_for_fastoutput(rack, tp, so, (uint32_t)acked);
11249 	if (sbavail(&so->so_snd)) {
11250 		rack->r_wanted_output = 1;
11251 	}
11252 	return (1);
11253 }
11254 
11255 /*
11256  * Return value of 1, the TCB is unlocked and most
11257  * likely gone, return value of 0, the TCP is still
11258  * locked.
11259  */
11260 static int
11261 rack_do_syn_sent(struct mbuf *m, struct tcphdr *th, struct socket *so,
11262     struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen,
11263     uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos)
11264 {
11265 	int32_t ret_val = 0;
11266 	int32_t todrop;
11267 	int32_t ourfinisacked = 0;
11268 	struct tcp_rack *rack;
11269 
11270 	ctf_calc_rwin(so, tp);
11271 	/*
11272 	 * If the state is SYN_SENT: if seg contains an ACK, but not for our
11273 	 * SYN, drop the input. if seg contains a RST, then drop the
11274 	 * connection. if seg does not contain SYN, then drop it. Otherwise
11275 	 * this is an acceptable SYN segment initialize tp->rcv_nxt and
11276 	 * tp->irs if seg contains ack then advance tp->snd_una if seg
11277 	 * contains an ECE and ECN support is enabled, the stream is ECN
11278 	 * capable. if SYN has been acked change to ESTABLISHED else
11279 	 * SYN_RCVD state arrange for segment to be acked (eventually)
11280 	 * continue processing rest of data/controls.
11281 	 */
11282 	if ((thflags & TH_ACK) &&
11283 	    (SEQ_LEQ(th->th_ack, tp->iss) ||
11284 	    SEQ_GT(th->th_ack, tp->snd_max))) {
11285 		tcp_log_end_status(tp, TCP_EI_STATUS_RST_IN_FRONT);
11286 		ctf_do_dropwithreset(m, tp, th, BANDLIM_RST_OPENPORT, tlen);
11287 		return (1);
11288 	}
11289 	if ((thflags & (TH_ACK | TH_RST)) == (TH_ACK | TH_RST)) {
11290 		TCP_PROBE5(connect__refused, NULL, tp,
11291 		    mtod(m, const char *), tp, th);
11292 		tp = tcp_drop(tp, ECONNREFUSED);
11293 		ctf_do_drop(m, tp);
11294 		return (1);
11295 	}
11296 	if (thflags & TH_RST) {
11297 		ctf_do_drop(m, tp);
11298 		return (1);
11299 	}
11300 	if (!(thflags & TH_SYN)) {
11301 		ctf_do_drop(m, tp);
11302 		return (1);
11303 	}
11304 	tp->irs = th->th_seq;
11305 	tcp_rcvseqinit(tp);
11306 	rack = (struct tcp_rack *)tp->t_fb_ptr;
11307 	if (thflags & TH_ACK) {
11308 		int tfo_partial = 0;
11309 
11310 		KMOD_TCPSTAT_INC(tcps_connects);
11311 		soisconnected(so);
11312 #ifdef MAC
11313 		mac_socketpeer_set_from_mbuf(m, so);
11314 #endif
11315 		/* Do window scaling on this connection? */
11316 		if ((tp->t_flags & (TF_RCVD_SCALE | TF_REQ_SCALE)) ==
11317 		    (TF_RCVD_SCALE | TF_REQ_SCALE)) {
11318 			tp->rcv_scale = tp->request_r_scale;
11319 		}
11320 		tp->rcv_adv += min(tp->rcv_wnd,
11321 		    TCP_MAXWIN << tp->rcv_scale);
11322 		/*
11323 		 * If not all the data that was sent in the TFO SYN
11324 		 * has been acked, resend the remainder right away.
11325 		 */
11326 		if (IS_FASTOPEN(tp->t_flags) &&
11327 		    (tp->snd_una != tp->snd_max)) {
11328 			tp->snd_nxt = th->th_ack;
11329 			tfo_partial = 1;
11330 		}
11331 		/*
11332 		 * If there's data, delay ACK; if there's also a FIN ACKNOW
11333 		 * will be turned on later.
11334 		 */
11335 		if (DELAY_ACK(tp, tlen) && tlen != 0 && !tfo_partial) {
11336 			rack_timer_cancel(tp, rack,
11337 					  rack->r_ctl.rc_rcvtime, __LINE__);
11338 			tp->t_flags |= TF_DELACK;
11339 		} else {
11340 			rack->r_wanted_output = 1;
11341 			tp->t_flags |= TF_ACKNOW;
11342 			rack->rc_dack_toggle = 0;
11343 		}
11344 		if (((thflags & (TH_CWR | TH_ECE)) == TH_ECE) &&
11345 		    (V_tcp_do_ecn == 1)) {
11346 			tp->t_flags2 |= TF2_ECN_PERMIT;
11347 			KMOD_TCPSTAT_INC(tcps_ecn_shs);
11348 		}
11349 		if (SEQ_GT(th->th_ack, tp->snd_una)) {
11350 			/*
11351 			 * We advance snd_una for the
11352 			 * fast open case. If th_ack is
11353 			 * acknowledging data beyond
11354 			 * snd_una we can't just call
11355 			 * ack-processing since the
11356 			 * data stream in our send-map
11357 			 * will start at snd_una + 1 (one
11358 			 * beyond the SYN). If its just
11359 			 * equal we don't need to do that
11360 			 * and there is no send_map.
11361 			 */
11362 			tp->snd_una++;
11363 		}
11364 		/*
11365 		 * Received <SYN,ACK> in SYN_SENT[*] state. Transitions:
11366 		 * SYN_SENT  --> ESTABLISHED SYN_SENT* --> FIN_WAIT_1
11367 		 */
11368 		tp->t_starttime = ticks;
11369 		if (tp->t_flags & TF_NEEDFIN) {
11370 			tcp_state_change(tp, TCPS_FIN_WAIT_1);
11371 			tp->t_flags &= ~TF_NEEDFIN;
11372 			thflags &= ~TH_SYN;
11373 		} else {
11374 			tcp_state_change(tp, TCPS_ESTABLISHED);
11375 			TCP_PROBE5(connect__established, NULL, tp,
11376 			    mtod(m, const char *), tp, th);
11377 			rack_cc_conn_init(tp);
11378 		}
11379 	} else {
11380 		/*
11381 		 * Received initial SYN in SYN-SENT[*] state => simultaneous
11382 		 * open.  If segment contains CC option and there is a
11383 		 * cached CC, apply TAO test. If it succeeds, connection is *
11384 		 * half-synchronized. Otherwise, do 3-way handshake:
11385 		 * SYN-SENT -> SYN-RECEIVED SYN-SENT* -> SYN-RECEIVED* If
11386 		 * there was no CC option, clear cached CC value.
11387 		 */
11388 		tp->t_flags |= (TF_ACKNOW | TF_NEEDSYN);
11389 		tcp_state_change(tp, TCPS_SYN_RECEIVED);
11390 	}
11391 	INP_WLOCK_ASSERT(tp->t_inpcb);
11392 	/*
11393 	 * Advance th->th_seq to correspond to first data byte. If data,
11394 	 * trim to stay within window, dropping FIN if necessary.
11395 	 */
11396 	th->th_seq++;
11397 	if (tlen > tp->rcv_wnd) {
11398 		todrop = tlen - tp->rcv_wnd;
11399 		m_adj(m, -todrop);
11400 		tlen = tp->rcv_wnd;
11401 		thflags &= ~TH_FIN;
11402 		KMOD_TCPSTAT_INC(tcps_rcvpackafterwin);
11403 		KMOD_TCPSTAT_ADD(tcps_rcvbyteafterwin, todrop);
11404 	}
11405 	tp->snd_wl1 = th->th_seq - 1;
11406 	tp->rcv_up = th->th_seq;
11407 	/*
11408 	 * Client side of transaction: already sent SYN and data. If the
11409 	 * remote host used T/TCP to validate the SYN, our data will be
11410 	 * ACK'd; if so, enter normal data segment processing in the middle
11411 	 * of step 5, ack processing. Otherwise, goto step 6.
11412 	 */
11413 	if (thflags & TH_ACK) {
11414 		/* For syn-sent we need to possibly update the rtt */
11415 		if ((to->to_flags & TOF_TS) != 0 && to->to_tsecr) {
11416 			uint32_t t, mcts;
11417 
11418 			mcts = tcp_ts_getticks();
11419 			t = (mcts - to->to_tsecr) * HPTS_USEC_IN_MSEC;
11420 			if (!tp->t_rttlow || tp->t_rttlow > t)
11421 				tp->t_rttlow = t;
11422 			rack_log_rtt_sample_calc(rack, t, (to->to_tsecr * 1000), (mcts * 1000), 4);
11423 			tcp_rack_xmit_timer(rack, t + 1, 1, t, 0, NULL, 2);
11424 			tcp_rack_xmit_timer_commit(rack, tp);
11425 		}
11426 		if (rack_process_ack(m, th, so, tp, to, tiwin, tlen, &ourfinisacked, thflags, &ret_val))
11427 			return (ret_val);
11428 		/* We may have changed to FIN_WAIT_1 above */
11429 		if (tp->t_state == TCPS_FIN_WAIT_1) {
11430 			/*
11431 			 * In FIN_WAIT_1 STATE in addition to the processing
11432 			 * for the ESTABLISHED state if our FIN is now
11433 			 * acknowledged then enter FIN_WAIT_2.
11434 			 */
11435 			if (ourfinisacked) {
11436 				/*
11437 				 * If we can't receive any more data, then
11438 				 * closing user can proceed. Starting the
11439 				 * timer is contrary to the specification,
11440 				 * but if we don't get a FIN we'll hang
11441 				 * forever.
11442 				 *
11443 				 * XXXjl: we should release the tp also, and
11444 				 * use a compressed state.
11445 				 */
11446 				if (so->so_rcv.sb_state & SBS_CANTRCVMORE) {
11447 					soisdisconnected(so);
11448 					tcp_timer_activate(tp, TT_2MSL,
11449 					    (tcp_fast_finwait2_recycle ?
11450 					    tcp_finwait2_timeout :
11451 					    TP_MAXIDLE(tp)));
11452 				}
11453 				tcp_state_change(tp, TCPS_FIN_WAIT_2);
11454 			}
11455 		}
11456 	}
11457 	return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
11458 	   tiwin, thflags, nxt_pkt));
11459 }
11460 
11461 /*
11462  * Return value of 1, the TCB is unlocked and most
11463  * likely gone, return value of 0, the TCP is still
11464  * locked.
11465  */
11466 static int
11467 rack_do_syn_recv(struct mbuf *m, struct tcphdr *th, struct socket *so,
11468     struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen,
11469     uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos)
11470 {
11471 	struct tcp_rack *rack;
11472 	int32_t ret_val = 0;
11473 	int32_t ourfinisacked = 0;
11474 
11475 	ctf_calc_rwin(so, tp);
11476 	if ((thflags & TH_ACK) &&
11477 	    (SEQ_LEQ(th->th_ack, tp->snd_una) ||
11478 	    SEQ_GT(th->th_ack, tp->snd_max))) {
11479 		tcp_log_end_status(tp, TCP_EI_STATUS_RST_IN_FRONT);
11480 		ctf_do_dropwithreset(m, tp, th, BANDLIM_RST_OPENPORT, tlen);
11481 		return (1);
11482 	}
11483 	rack = (struct tcp_rack *)tp->t_fb_ptr;
11484 	if (IS_FASTOPEN(tp->t_flags)) {
11485 		/*
11486 		 * When a TFO connection is in SYN_RECEIVED, the
11487 		 * only valid packets are the initial SYN, a
11488 		 * retransmit/copy of the initial SYN (possibly with
11489 		 * a subset of the original data), a valid ACK, a
11490 		 * FIN, or a RST.
11491 		 */
11492 		if ((thflags & (TH_SYN | TH_ACK)) == (TH_SYN | TH_ACK)) {
11493 			tcp_log_end_status(tp, TCP_EI_STATUS_RST_IN_FRONT);
11494 			ctf_do_dropwithreset(m, tp, th, BANDLIM_RST_OPENPORT, tlen);
11495 			return (1);
11496 		} else if (thflags & TH_SYN) {
11497 			/* non-initial SYN is ignored */
11498 			if ((rack->r_ctl.rc_hpts_flags & PACE_TMR_RXT) ||
11499 			    (rack->r_ctl.rc_hpts_flags & PACE_TMR_TLP) ||
11500 			    (rack->r_ctl.rc_hpts_flags & PACE_TMR_RACK)) {
11501 				ctf_do_drop(m, NULL);
11502 				return (0);
11503 			}
11504 		} else if (!(thflags & (TH_ACK | TH_FIN | TH_RST))) {
11505 			ctf_do_drop(m, NULL);
11506 			return (0);
11507 		}
11508 	}
11509 	if ((thflags & TH_RST) ||
11510 	    (tp->t_fin_is_rst && (thflags & TH_FIN)))
11511 		return (ctf_process_rst(m, th, so, tp));
11512 	/*
11513 	 * RFC 1323 PAWS: If we have a timestamp reply on this segment and
11514 	 * it's less than ts_recent, drop it.
11515 	 */
11516 	if ((to->to_flags & TOF_TS) != 0 && tp->ts_recent &&
11517 	    TSTMP_LT(to->to_tsval, tp->ts_recent)) {
11518 		if (ctf_ts_check(m, th, tp, tlen, thflags, &ret_val))
11519 			return (ret_val);
11520 	}
11521 	/*
11522 	 * In the SYN-RECEIVED state, validate that the packet belongs to
11523 	 * this connection before trimming the data to fit the receive
11524 	 * window.  Check the sequence number versus IRS since we know the
11525 	 * sequence numbers haven't wrapped.  This is a partial fix for the
11526 	 * "LAND" DoS attack.
11527 	 */
11528 	if (SEQ_LT(th->th_seq, tp->irs)) {
11529 		tcp_log_end_status(tp, TCP_EI_STATUS_RST_IN_FRONT);
11530 		ctf_do_dropwithreset(m, tp, th, BANDLIM_RST_OPENPORT, tlen);
11531 		return (1);
11532 	}
11533 	if (_ctf_drop_checks(to, m, th, tp, &tlen, &thflags, &drop_hdrlen, &ret_val,
11534 			      &rack->r_ctl.challenge_ack_ts,
11535 			      &rack->r_ctl.challenge_ack_cnt)) {
11536 		return (ret_val);
11537 	}
11538 	/*
11539 	 * If last ACK falls within this segment's sequence numbers, record
11540 	 * its timestamp. NOTE: 1) That the test incorporates suggestions
11541 	 * from the latest proposal of the tcplw@cray.com list (Braden
11542 	 * 1993/04/26). 2) That updating only on newer timestamps interferes
11543 	 * with our earlier PAWS tests, so this check should be solely
11544 	 * predicated on the sequence space of this segment. 3) That we
11545 	 * modify the segment boundary check to be Last.ACK.Sent <= SEG.SEQ
11546 	 * + SEG.Len  instead of RFC1323's Last.ACK.Sent < SEG.SEQ +
11547 	 * SEG.Len, This modified check allows us to overcome RFC1323's
11548 	 * limitations as described in Stevens TCP/IP Illustrated Vol. 2
11549 	 * p.869. In such cases, we can still calculate the RTT correctly
11550 	 * when RCV.NXT == Last.ACK.Sent.
11551 	 */
11552 	if ((to->to_flags & TOF_TS) != 0 &&
11553 	    SEQ_LEQ(th->th_seq, tp->last_ack_sent) &&
11554 	    SEQ_LEQ(tp->last_ack_sent, th->th_seq + tlen +
11555 	    ((thflags & (TH_SYN | TH_FIN)) != 0))) {
11556 		tp->ts_recent_age = tcp_ts_getticks();
11557 		tp->ts_recent = to->to_tsval;
11558 	}
11559 	tp->snd_wnd = tiwin;
11560 	rack_validate_fo_sendwin_up(tp, rack);
11561 	/*
11562 	 * If the ACK bit is off:  if in SYN-RECEIVED state or SENDSYN flag
11563 	 * is on (half-synchronized state), then queue data for later
11564 	 * processing; else drop segment and return.
11565 	 */
11566 	if ((thflags & TH_ACK) == 0) {
11567 		if (IS_FASTOPEN(tp->t_flags)) {
11568 			rack_cc_conn_init(tp);
11569 		}
11570 		return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
11571 		    tiwin, thflags, nxt_pkt));
11572 	}
11573 	KMOD_TCPSTAT_INC(tcps_connects);
11574 	soisconnected(so);
11575 	/* Do window scaling? */
11576 	if ((tp->t_flags & (TF_RCVD_SCALE | TF_REQ_SCALE)) ==
11577 	    (TF_RCVD_SCALE | TF_REQ_SCALE)) {
11578 		tp->rcv_scale = tp->request_r_scale;
11579 	}
11580 	/*
11581 	 * Make transitions: SYN-RECEIVED  -> ESTABLISHED SYN-RECEIVED* ->
11582 	 * FIN-WAIT-1
11583 	 */
11584 	tp->t_starttime = ticks;
11585 	if (IS_FASTOPEN(tp->t_flags) && tp->t_tfo_pending) {
11586 		tcp_fastopen_decrement_counter(tp->t_tfo_pending);
11587 		tp->t_tfo_pending = NULL;
11588 	}
11589 	if (tp->t_flags & TF_NEEDFIN) {
11590 		tcp_state_change(tp, TCPS_FIN_WAIT_1);
11591 		tp->t_flags &= ~TF_NEEDFIN;
11592 	} else {
11593 		tcp_state_change(tp, TCPS_ESTABLISHED);
11594 		TCP_PROBE5(accept__established, NULL, tp,
11595 		    mtod(m, const char *), tp, th);
11596 		/*
11597 		 * TFO connections call cc_conn_init() during SYN
11598 		 * processing.  Calling it again here for such connections
11599 		 * is not harmless as it would undo the snd_cwnd reduction
11600 		 * that occurs when a TFO SYN|ACK is retransmitted.
11601 		 */
11602 		if (!IS_FASTOPEN(tp->t_flags))
11603 			rack_cc_conn_init(tp);
11604 	}
11605 	/*
11606 	 * Account for the ACK of our SYN prior to
11607 	 * regular ACK processing below, except for
11608 	 * simultaneous SYN, which is handled later.
11609 	 */
11610 	if (SEQ_GT(th->th_ack, tp->snd_una) && !(tp->t_flags & TF_NEEDSYN))
11611 		tp->snd_una++;
11612 	/*
11613 	 * If segment contains data or ACK, will call tcp_reass() later; if
11614 	 * not, do so now to pass queued data to user.
11615 	 */
11616 	if (tlen == 0 && (thflags & TH_FIN) == 0) {
11617 		(void) tcp_reass(tp, (struct tcphdr *)0, NULL, 0,
11618 		    (struct mbuf *)0);
11619 		if (tp->t_flags & TF_WAKESOR) {
11620 			tp->t_flags &= ~TF_WAKESOR;
11621 			/* NB: sorwakeup_locked() does an implicit unlock. */
11622 			sorwakeup_locked(so);
11623 		}
11624 	}
11625 	tp->snd_wl1 = th->th_seq - 1;
11626 	/* For syn-recv we need to possibly update the rtt */
11627 	if ((to->to_flags & TOF_TS) != 0 && to->to_tsecr) {
11628 		uint32_t t, mcts;
11629 
11630 		mcts = tcp_ts_getticks();
11631 		t = (mcts - to->to_tsecr) * HPTS_USEC_IN_MSEC;
11632 		if (!tp->t_rttlow || tp->t_rttlow > t)
11633 			tp->t_rttlow = t;
11634 		rack_log_rtt_sample_calc(rack, t, (to->to_tsecr * 1000), (mcts * 1000), 5);
11635 		tcp_rack_xmit_timer(rack, t + 1, 1, t, 0, NULL, 2);
11636 		tcp_rack_xmit_timer_commit(rack, tp);
11637 	}
11638 	if (rack_process_ack(m, th, so, tp, to, tiwin, tlen, &ourfinisacked, thflags, &ret_val)) {
11639 		return (ret_val);
11640 	}
11641 	if (tp->t_state == TCPS_FIN_WAIT_1) {
11642 		/* We could have went to FIN_WAIT_1 (or EST) above */
11643 		/*
11644 		 * In FIN_WAIT_1 STATE in addition to the processing for the
11645 		 * ESTABLISHED state if our FIN is now acknowledged then
11646 		 * enter FIN_WAIT_2.
11647 		 */
11648 		if (ourfinisacked) {
11649 			/*
11650 			 * If we can't receive any more data, then closing
11651 			 * user can proceed. Starting the timer is contrary
11652 			 * to the specification, but if we don't get a FIN
11653 			 * we'll hang forever.
11654 			 *
11655 			 * XXXjl: we should release the tp also, and use a
11656 			 * compressed state.
11657 			 */
11658 			if (so->so_rcv.sb_state & SBS_CANTRCVMORE) {
11659 				soisdisconnected(so);
11660 				tcp_timer_activate(tp, TT_2MSL,
11661 				    (tcp_fast_finwait2_recycle ?
11662 				    tcp_finwait2_timeout :
11663 				    TP_MAXIDLE(tp)));
11664 			}
11665 			tcp_state_change(tp, TCPS_FIN_WAIT_2);
11666 		}
11667 	}
11668 	return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
11669 	    tiwin, thflags, nxt_pkt));
11670 }
11671 
11672 /*
11673  * Return value of 1, the TCB is unlocked and most
11674  * likely gone, return value of 0, the TCP is still
11675  * locked.
11676  */
11677 static int
11678 rack_do_established(struct mbuf *m, struct tcphdr *th, struct socket *so,
11679     struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen,
11680     uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos)
11681 {
11682 	int32_t ret_val = 0;
11683 	struct tcp_rack *rack;
11684 
11685 	/*
11686 	 * Header prediction: check for the two common cases of a
11687 	 * uni-directional data xfer.  If the packet has no control flags,
11688 	 * is in-sequence, the window didn't change and we're not
11689 	 * retransmitting, it's a candidate.  If the length is zero and the
11690 	 * ack moved forward, we're the sender side of the xfer.  Just free
11691 	 * the data acked & wake any higher level process that was blocked
11692 	 * waiting for space.  If the length is non-zero and the ack didn't
11693 	 * move, we're the receiver side.  If we're getting packets in-order
11694 	 * (the reassembly queue is empty), add the data toc The socket
11695 	 * buffer and note that we need a delayed ack. Make sure that the
11696 	 * hidden state-flags are also off. Since we check for
11697 	 * TCPS_ESTABLISHED first, it can only be TH_NEEDSYN.
11698 	 */
11699 	rack = (struct tcp_rack *)tp->t_fb_ptr;
11700 	if (__predict_true(((to->to_flags & TOF_SACK) == 0)) &&
11701 	    __predict_true((thflags & (TH_SYN | TH_FIN | TH_RST | TH_ACK)) == TH_ACK) &&
11702 	    __predict_true(SEGQ_EMPTY(tp)) &&
11703 	    __predict_true(th->th_seq == tp->rcv_nxt)) {
11704 		if (tlen == 0) {
11705 			if (rack_fastack(m, th, so, tp, to, drop_hdrlen, tlen,
11706 			    tiwin, nxt_pkt, rack->r_ctl.rc_rcvtime)) {
11707 				return (0);
11708 			}
11709 		} else {
11710 			if (rack_do_fastnewdata(m, th, so, tp, to, drop_hdrlen, tlen,
11711 			    tiwin, nxt_pkt, iptos)) {
11712 				return (0);
11713 			}
11714 		}
11715 	}
11716 	ctf_calc_rwin(so, tp);
11717 
11718 	if ((thflags & TH_RST) ||
11719 	    (tp->t_fin_is_rst && (thflags & TH_FIN)))
11720 		return (ctf_process_rst(m, th, so, tp));
11721 
11722 	/*
11723 	 * RFC5961 Section 4.2 Send challenge ACK for any SYN in
11724 	 * synchronized state.
11725 	 */
11726 	if (thflags & TH_SYN) {
11727 		ctf_challenge_ack(m, th, tp, &ret_val);
11728 		return (ret_val);
11729 	}
11730 	/*
11731 	 * RFC 1323 PAWS: If we have a timestamp reply on this segment and
11732 	 * it's less than ts_recent, drop it.
11733 	 */
11734 	if ((to->to_flags & TOF_TS) != 0 && tp->ts_recent &&
11735 	    TSTMP_LT(to->to_tsval, tp->ts_recent)) {
11736 		if (ctf_ts_check(m, th, tp, tlen, thflags, &ret_val))
11737 			return (ret_val);
11738 	}
11739 	if (_ctf_drop_checks(to, m, th, tp, &tlen, &thflags, &drop_hdrlen, &ret_val,
11740 			      &rack->r_ctl.challenge_ack_ts,
11741 			      &rack->r_ctl.challenge_ack_cnt)) {
11742 		return (ret_val);
11743 	}
11744 	/*
11745 	 * If last ACK falls within this segment's sequence numbers, record
11746 	 * its timestamp. NOTE: 1) That the test incorporates suggestions
11747 	 * from the latest proposal of the tcplw@cray.com list (Braden
11748 	 * 1993/04/26). 2) That updating only on newer timestamps interferes
11749 	 * with our earlier PAWS tests, so this check should be solely
11750 	 * predicated on the sequence space of this segment. 3) That we
11751 	 * modify the segment boundary check to be Last.ACK.Sent <= SEG.SEQ
11752 	 * + SEG.Len  instead of RFC1323's Last.ACK.Sent < SEG.SEQ +
11753 	 * SEG.Len, This modified check allows us to overcome RFC1323's
11754 	 * limitations as described in Stevens TCP/IP Illustrated Vol. 2
11755 	 * p.869. In such cases, we can still calculate the RTT correctly
11756 	 * when RCV.NXT == Last.ACK.Sent.
11757 	 */
11758 	if ((to->to_flags & TOF_TS) != 0 &&
11759 	    SEQ_LEQ(th->th_seq, tp->last_ack_sent) &&
11760 	    SEQ_LEQ(tp->last_ack_sent, th->th_seq + tlen +
11761 	    ((thflags & (TH_SYN | TH_FIN)) != 0))) {
11762 		tp->ts_recent_age = tcp_ts_getticks();
11763 		tp->ts_recent = to->to_tsval;
11764 	}
11765 	/*
11766 	 * If the ACK bit is off:  if in SYN-RECEIVED state or SENDSYN flag
11767 	 * is on (half-synchronized state), then queue data for later
11768 	 * processing; else drop segment and return.
11769 	 */
11770 	if ((thflags & TH_ACK) == 0) {
11771 		if (tp->t_flags & TF_NEEDSYN) {
11772 			return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
11773 			    tiwin, thflags, nxt_pkt));
11774 
11775 		} else if (tp->t_flags & TF_ACKNOW) {
11776 			ctf_do_dropafterack(m, tp, th, thflags, tlen, &ret_val);
11777 			((struct tcp_rack *)tp->t_fb_ptr)->r_wanted_output = 1;
11778 			return (ret_val);
11779 		} else {
11780 			ctf_do_drop(m, NULL);
11781 			return (0);
11782 		}
11783 	}
11784 	/*
11785 	 * Ack processing.
11786 	 */
11787 	if (rack_process_ack(m, th, so, tp, to, tiwin, tlen, NULL, thflags, &ret_val)) {
11788 		return (ret_val);
11789 	}
11790 	if (sbavail(&so->so_snd)) {
11791 		if (ctf_progress_timeout_check(tp, true)) {
11792 			rack_log_progress_event(rack, tp, tick, PROGRESS_DROP, __LINE__);
11793 			tcp_set_inp_to_drop(tp->t_inpcb, ETIMEDOUT);
11794 			ctf_do_dropwithreset(m, tp, th, BANDLIM_RST_OPENPORT, tlen);
11795 			return (1);
11796 		}
11797 	}
11798 	/* State changes only happen in rack_process_data() */
11799 	return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
11800 	    tiwin, thflags, nxt_pkt));
11801 }
11802 
11803 /*
11804  * Return value of 1, the TCB is unlocked and most
11805  * likely gone, return value of 0, the TCP is still
11806  * locked.
11807  */
11808 static int
11809 rack_do_close_wait(struct mbuf *m, struct tcphdr *th, struct socket *so,
11810     struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen,
11811     uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos)
11812 {
11813 	int32_t ret_val = 0;
11814 	struct tcp_rack *rack;
11815 
11816 	rack = (struct tcp_rack *)tp->t_fb_ptr;
11817 	ctf_calc_rwin(so, tp);
11818 	if ((thflags & TH_RST) ||
11819 	    (tp->t_fin_is_rst && (thflags & TH_FIN)))
11820 		return (ctf_process_rst(m, th, so, tp));
11821 	/*
11822 	 * RFC5961 Section 4.2 Send challenge ACK for any SYN in
11823 	 * synchronized state.
11824 	 */
11825 	if (thflags & TH_SYN) {
11826 		ctf_challenge_ack(m, th, tp, &ret_val);
11827 		return (ret_val);
11828 	}
11829 	/*
11830 	 * RFC 1323 PAWS: If we have a timestamp reply on this segment and
11831 	 * it's less than ts_recent, drop it.
11832 	 */
11833 	if ((to->to_flags & TOF_TS) != 0 && tp->ts_recent &&
11834 	    TSTMP_LT(to->to_tsval, tp->ts_recent)) {
11835 		if (ctf_ts_check(m, th, tp, tlen, thflags, &ret_val))
11836 			return (ret_val);
11837 	}
11838 	if (_ctf_drop_checks(to, m, th, tp, &tlen, &thflags, &drop_hdrlen, &ret_val,
11839 			      &rack->r_ctl.challenge_ack_ts,
11840 			      &rack->r_ctl.challenge_ack_cnt)) {
11841 		return (ret_val);
11842 	}
11843 	/*
11844 	 * If last ACK falls within this segment's sequence numbers, record
11845 	 * its timestamp. NOTE: 1) That the test incorporates suggestions
11846 	 * from the latest proposal of the tcplw@cray.com list (Braden
11847 	 * 1993/04/26). 2) That updating only on newer timestamps interferes
11848 	 * with our earlier PAWS tests, so this check should be solely
11849 	 * predicated on the sequence space of this segment. 3) That we
11850 	 * modify the segment boundary check to be Last.ACK.Sent <= SEG.SEQ
11851 	 * + SEG.Len  instead of RFC1323's Last.ACK.Sent < SEG.SEQ +
11852 	 * SEG.Len, This modified check allows us to overcome RFC1323's
11853 	 * limitations as described in Stevens TCP/IP Illustrated Vol. 2
11854 	 * p.869. In such cases, we can still calculate the RTT correctly
11855 	 * when RCV.NXT == Last.ACK.Sent.
11856 	 */
11857 	if ((to->to_flags & TOF_TS) != 0 &&
11858 	    SEQ_LEQ(th->th_seq, tp->last_ack_sent) &&
11859 	    SEQ_LEQ(tp->last_ack_sent, th->th_seq + tlen +
11860 	    ((thflags & (TH_SYN | TH_FIN)) != 0))) {
11861 		tp->ts_recent_age = tcp_ts_getticks();
11862 		tp->ts_recent = to->to_tsval;
11863 	}
11864 	/*
11865 	 * If the ACK bit is off:  if in SYN-RECEIVED state or SENDSYN flag
11866 	 * is on (half-synchronized state), then queue data for later
11867 	 * processing; else drop segment and return.
11868 	 */
11869 	if ((thflags & TH_ACK) == 0) {
11870 		if (tp->t_flags & TF_NEEDSYN) {
11871 			return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
11872 			    tiwin, thflags, nxt_pkt));
11873 
11874 		} else if (tp->t_flags & TF_ACKNOW) {
11875 			ctf_do_dropafterack(m, tp, th, thflags, tlen, &ret_val);
11876 			((struct tcp_rack *)tp->t_fb_ptr)->r_wanted_output = 1;
11877 			return (ret_val);
11878 		} else {
11879 			ctf_do_drop(m, NULL);
11880 			return (0);
11881 		}
11882 	}
11883 	/*
11884 	 * Ack processing.
11885 	 */
11886 	if (rack_process_ack(m, th, so, tp, to, tiwin, tlen, NULL, thflags, &ret_val)) {
11887 		return (ret_val);
11888 	}
11889 	if (sbavail(&so->so_snd)) {
11890 		if (ctf_progress_timeout_check(tp, true)) {
11891 			rack_log_progress_event((struct tcp_rack *)tp->t_fb_ptr,
11892 						tp, tick, PROGRESS_DROP, __LINE__);
11893 			tcp_set_inp_to_drop(tp->t_inpcb, ETIMEDOUT);
11894 			ctf_do_dropwithreset(m, tp, th, BANDLIM_RST_OPENPORT, tlen);
11895 			return (1);
11896 		}
11897 	}
11898 	return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
11899 	    tiwin, thflags, nxt_pkt));
11900 }
11901 
11902 static int
11903 rack_check_data_after_close(struct mbuf *m,
11904     struct tcpcb *tp, int32_t *tlen, struct tcphdr *th, struct socket *so)
11905 {
11906 	struct tcp_rack *rack;
11907 
11908 	rack = (struct tcp_rack *)tp->t_fb_ptr;
11909 	if (rack->rc_allow_data_af_clo == 0) {
11910 	close_now:
11911 		tcp_log_end_status(tp, TCP_EI_STATUS_DATA_A_CLOSE);
11912 		/* tcp_close will kill the inp pre-log the Reset */
11913 		tcp_log_end_status(tp, TCP_EI_STATUS_SERVER_RST);
11914 		tp = tcp_close(tp);
11915 		KMOD_TCPSTAT_INC(tcps_rcvafterclose);
11916 		ctf_do_dropwithreset(m, tp, th, BANDLIM_UNLIMITED, (*tlen));
11917 		return (1);
11918 	}
11919 	if (sbavail(&so->so_snd) == 0)
11920 		goto close_now;
11921 	/* Ok we allow data that is ignored and a followup reset */
11922 	tcp_log_end_status(tp, TCP_EI_STATUS_DATA_A_CLOSE);
11923 	tp->rcv_nxt = th->th_seq + *tlen;
11924 	tp->t_flags2 |= TF2_DROP_AF_DATA;
11925 	rack->r_wanted_output = 1;
11926 	*tlen = 0;
11927 	return (0);
11928 }
11929 
11930 /*
11931  * Return value of 1, the TCB is unlocked and most
11932  * likely gone, return value of 0, the TCP is still
11933  * locked.
11934  */
11935 static int
11936 rack_do_fin_wait_1(struct mbuf *m, struct tcphdr *th, struct socket *so,
11937     struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen,
11938     uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos)
11939 {
11940 	int32_t ret_val = 0;
11941 	int32_t ourfinisacked = 0;
11942 	struct tcp_rack *rack;
11943 
11944 	rack = (struct tcp_rack *)tp->t_fb_ptr;
11945 	ctf_calc_rwin(so, tp);
11946 
11947 	if ((thflags & TH_RST) ||
11948 	    (tp->t_fin_is_rst && (thflags & TH_FIN)))
11949 		return (ctf_process_rst(m, th, so, tp));
11950 	/*
11951 	 * RFC5961 Section 4.2 Send challenge ACK for any SYN in
11952 	 * synchronized state.
11953 	 */
11954 	if (thflags & TH_SYN) {
11955 		ctf_challenge_ack(m, th, tp, &ret_val);
11956 		return (ret_val);
11957 	}
11958 	/*
11959 	 * RFC 1323 PAWS: If we have a timestamp reply on this segment and
11960 	 * it's less than ts_recent, drop it.
11961 	 */
11962 	if ((to->to_flags & TOF_TS) != 0 && tp->ts_recent &&
11963 	    TSTMP_LT(to->to_tsval, tp->ts_recent)) {
11964 		if (ctf_ts_check(m, th, tp, tlen, thflags, &ret_val))
11965 			return (ret_val);
11966 	}
11967 	if (_ctf_drop_checks(to, m, th, tp, &tlen, &thflags, &drop_hdrlen, &ret_val,
11968 			      &rack->r_ctl.challenge_ack_ts,
11969 			      &rack->r_ctl.challenge_ack_cnt)) {
11970 		return (ret_val);
11971 	}
11972 	/*
11973 	 * If new data are received on a connection after the user processes
11974 	 * are gone, then RST the other end.
11975 	 */
11976 	if ((so->so_state & SS_NOFDREF) && tlen) {
11977 		if (rack_check_data_after_close(m, tp, &tlen, th, so))
11978 			return (1);
11979 	}
11980 	/*
11981 	 * If last ACK falls within this segment's sequence numbers, record
11982 	 * its timestamp. NOTE: 1) That the test incorporates suggestions
11983 	 * from the latest proposal of the tcplw@cray.com list (Braden
11984 	 * 1993/04/26). 2) That updating only on newer timestamps interferes
11985 	 * with our earlier PAWS tests, so this check should be solely
11986 	 * predicated on the sequence space of this segment. 3) That we
11987 	 * modify the segment boundary check to be Last.ACK.Sent <= SEG.SEQ
11988 	 * + SEG.Len  instead of RFC1323's Last.ACK.Sent < SEG.SEQ +
11989 	 * SEG.Len, This modified check allows us to overcome RFC1323's
11990 	 * limitations as described in Stevens TCP/IP Illustrated Vol. 2
11991 	 * p.869. In such cases, we can still calculate the RTT correctly
11992 	 * when RCV.NXT == Last.ACK.Sent.
11993 	 */
11994 	if ((to->to_flags & TOF_TS) != 0 &&
11995 	    SEQ_LEQ(th->th_seq, tp->last_ack_sent) &&
11996 	    SEQ_LEQ(tp->last_ack_sent, th->th_seq + tlen +
11997 	    ((thflags & (TH_SYN | TH_FIN)) != 0))) {
11998 		tp->ts_recent_age = tcp_ts_getticks();
11999 		tp->ts_recent = to->to_tsval;
12000 	}
12001 	/*
12002 	 * If the ACK bit is off:  if in SYN-RECEIVED state or SENDSYN flag
12003 	 * is on (half-synchronized state), then queue data for later
12004 	 * processing; else drop segment and return.
12005 	 */
12006 	if ((thflags & TH_ACK) == 0) {
12007 		if (tp->t_flags & TF_NEEDSYN) {
12008 			return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
12009 			    tiwin, thflags, nxt_pkt));
12010 		} else if (tp->t_flags & TF_ACKNOW) {
12011 			ctf_do_dropafterack(m, tp, th, thflags, tlen, &ret_val);
12012 			((struct tcp_rack *)tp->t_fb_ptr)->r_wanted_output = 1;
12013 			return (ret_val);
12014 		} else {
12015 			ctf_do_drop(m, NULL);
12016 			return (0);
12017 		}
12018 	}
12019 	/*
12020 	 * Ack processing.
12021 	 */
12022 	if (rack_process_ack(m, th, so, tp, to, tiwin, tlen, &ourfinisacked, thflags, &ret_val)) {
12023 		return (ret_val);
12024 	}
12025 	if (ourfinisacked) {
12026 		/*
12027 		 * If we can't receive any more data, then closing user can
12028 		 * proceed. Starting the timer is contrary to the
12029 		 * specification, but if we don't get a FIN we'll hang
12030 		 * forever.
12031 		 *
12032 		 * XXXjl: we should release the tp also, and use a
12033 		 * compressed state.
12034 		 */
12035 		if (so->so_rcv.sb_state & SBS_CANTRCVMORE) {
12036 			soisdisconnected(so);
12037 			tcp_timer_activate(tp, TT_2MSL,
12038 			    (tcp_fast_finwait2_recycle ?
12039 			    tcp_finwait2_timeout :
12040 			    TP_MAXIDLE(tp)));
12041 		}
12042 		tcp_state_change(tp, TCPS_FIN_WAIT_2);
12043 	}
12044 	if (sbavail(&so->so_snd)) {
12045 		if (ctf_progress_timeout_check(tp, true)) {
12046 			rack_log_progress_event((struct tcp_rack *)tp->t_fb_ptr,
12047 						tp, tick, PROGRESS_DROP, __LINE__);
12048 			tcp_set_inp_to_drop(tp->t_inpcb, ETIMEDOUT);
12049 			ctf_do_dropwithreset(m, tp, th, BANDLIM_RST_OPENPORT, tlen);
12050 			return (1);
12051 		}
12052 	}
12053 	return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
12054 	    tiwin, thflags, nxt_pkt));
12055 }
12056 
12057 /*
12058  * Return value of 1, the TCB is unlocked and most
12059  * likely gone, return value of 0, the TCP is still
12060  * locked.
12061  */
12062 static int
12063 rack_do_closing(struct mbuf *m, struct tcphdr *th, struct socket *so,
12064     struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen,
12065     uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos)
12066 {
12067 	int32_t ret_val = 0;
12068 	int32_t ourfinisacked = 0;
12069 	struct tcp_rack *rack;
12070 
12071 	rack = (struct tcp_rack *)tp->t_fb_ptr;
12072 	ctf_calc_rwin(so, tp);
12073 
12074 	if ((thflags & TH_RST) ||
12075 	    (tp->t_fin_is_rst && (thflags & TH_FIN)))
12076 		return (ctf_process_rst(m, th, so, tp));
12077 	/*
12078 	 * RFC5961 Section 4.2 Send challenge ACK for any SYN in
12079 	 * synchronized state.
12080 	 */
12081 	if (thflags & TH_SYN) {
12082 		ctf_challenge_ack(m, th, tp, &ret_val);
12083 		return (ret_val);
12084 	}
12085 	/*
12086 	 * RFC 1323 PAWS: If we have a timestamp reply on this segment and
12087 	 * it's less than ts_recent, drop it.
12088 	 */
12089 	if ((to->to_flags & TOF_TS) != 0 && tp->ts_recent &&
12090 	    TSTMP_LT(to->to_tsval, tp->ts_recent)) {
12091 		if (ctf_ts_check(m, th, tp, tlen, thflags, &ret_val))
12092 			return (ret_val);
12093 	}
12094 	if (_ctf_drop_checks(to, m, th, tp, &tlen, &thflags, &drop_hdrlen, &ret_val,
12095 			      &rack->r_ctl.challenge_ack_ts,
12096 			      &rack->r_ctl.challenge_ack_cnt)) {
12097 		return (ret_val);
12098 	}
12099 	/*
12100 	 * If new data are received on a connection after the user processes
12101 	 * are gone, then RST the other end.
12102 	 */
12103 	if ((so->so_state & SS_NOFDREF) && tlen) {
12104 		if (rack_check_data_after_close(m, tp, &tlen, th, so))
12105 			return (1);
12106 	}
12107 	/*
12108 	 * If last ACK falls within this segment's sequence numbers, record
12109 	 * its timestamp. NOTE: 1) That the test incorporates suggestions
12110 	 * from the latest proposal of the tcplw@cray.com list (Braden
12111 	 * 1993/04/26). 2) That updating only on newer timestamps interferes
12112 	 * with our earlier PAWS tests, so this check should be solely
12113 	 * predicated on the sequence space of this segment. 3) That we
12114 	 * modify the segment boundary check to be Last.ACK.Sent <= SEG.SEQ
12115 	 * + SEG.Len  instead of RFC1323's Last.ACK.Sent < SEG.SEQ +
12116 	 * SEG.Len, This modified check allows us to overcome RFC1323's
12117 	 * limitations as described in Stevens TCP/IP Illustrated Vol. 2
12118 	 * p.869. In such cases, we can still calculate the RTT correctly
12119 	 * when RCV.NXT == Last.ACK.Sent.
12120 	 */
12121 	if ((to->to_flags & TOF_TS) != 0 &&
12122 	    SEQ_LEQ(th->th_seq, tp->last_ack_sent) &&
12123 	    SEQ_LEQ(tp->last_ack_sent, th->th_seq + tlen +
12124 	    ((thflags & (TH_SYN | TH_FIN)) != 0))) {
12125 		tp->ts_recent_age = tcp_ts_getticks();
12126 		tp->ts_recent = to->to_tsval;
12127 	}
12128 	/*
12129 	 * If the ACK bit is off:  if in SYN-RECEIVED state or SENDSYN flag
12130 	 * is on (half-synchronized state), then queue data for later
12131 	 * processing; else drop segment and return.
12132 	 */
12133 	if ((thflags & TH_ACK) == 0) {
12134 		if (tp->t_flags & TF_NEEDSYN) {
12135 			return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
12136 			    tiwin, thflags, nxt_pkt));
12137 		} else if (tp->t_flags & TF_ACKNOW) {
12138 			ctf_do_dropafterack(m, tp, th, thflags, tlen, &ret_val);
12139 			((struct tcp_rack *)tp->t_fb_ptr)->r_wanted_output = 1;
12140 			return (ret_val);
12141 		} else {
12142 			ctf_do_drop(m, NULL);
12143 			return (0);
12144 		}
12145 	}
12146 	/*
12147 	 * Ack processing.
12148 	 */
12149 	if (rack_process_ack(m, th, so, tp, to, tiwin, tlen, &ourfinisacked, thflags, &ret_val)) {
12150 		return (ret_val);
12151 	}
12152 	if (ourfinisacked) {
12153 		tcp_twstart(tp);
12154 		m_freem(m);
12155 		return (1);
12156 	}
12157 	if (sbavail(&so->so_snd)) {
12158 		if (ctf_progress_timeout_check(tp, true)) {
12159 			rack_log_progress_event((struct tcp_rack *)tp->t_fb_ptr,
12160 						tp, tick, PROGRESS_DROP, __LINE__);
12161 			tcp_set_inp_to_drop(tp->t_inpcb, ETIMEDOUT);
12162 			ctf_do_dropwithreset(m, tp, th, BANDLIM_RST_OPENPORT, tlen);
12163 			return (1);
12164 		}
12165 	}
12166 	return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
12167 	    tiwin, thflags, nxt_pkt));
12168 }
12169 
12170 /*
12171  * Return value of 1, the TCB is unlocked and most
12172  * likely gone, return value of 0, the TCP is still
12173  * locked.
12174  */
12175 static int
12176 rack_do_lastack(struct mbuf *m, struct tcphdr *th, struct socket *so,
12177     struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen,
12178     uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos)
12179 {
12180 	int32_t ret_val = 0;
12181 	int32_t ourfinisacked = 0;
12182 	struct tcp_rack *rack;
12183 
12184 	rack = (struct tcp_rack *)tp->t_fb_ptr;
12185 	ctf_calc_rwin(so, tp);
12186 
12187 	if ((thflags & TH_RST) ||
12188 	    (tp->t_fin_is_rst && (thflags & TH_FIN)))
12189 		return (ctf_process_rst(m, th, so, tp));
12190 	/*
12191 	 * RFC5961 Section 4.2 Send challenge ACK for any SYN in
12192 	 * synchronized state.
12193 	 */
12194 	if (thflags & TH_SYN) {
12195 		ctf_challenge_ack(m, th, tp, &ret_val);
12196 		return (ret_val);
12197 	}
12198 	/*
12199 	 * RFC 1323 PAWS: If we have a timestamp reply on this segment and
12200 	 * it's less than ts_recent, drop it.
12201 	 */
12202 	if ((to->to_flags & TOF_TS) != 0 && tp->ts_recent &&
12203 	    TSTMP_LT(to->to_tsval, tp->ts_recent)) {
12204 		if (ctf_ts_check(m, th, tp, tlen, thflags, &ret_val))
12205 			return (ret_val);
12206 	}
12207 	if (_ctf_drop_checks(to, m, th, tp, &tlen, &thflags, &drop_hdrlen, &ret_val,
12208 			      &rack->r_ctl.challenge_ack_ts,
12209 			      &rack->r_ctl.challenge_ack_cnt)) {
12210 		return (ret_val);
12211 	}
12212 	/*
12213 	 * If new data are received on a connection after the user processes
12214 	 * are gone, then RST the other end.
12215 	 */
12216 	if ((so->so_state & SS_NOFDREF) && tlen) {
12217 		if (rack_check_data_after_close(m, tp, &tlen, th, so))
12218 			return (1);
12219 	}
12220 	/*
12221 	 * If last ACK falls within this segment's sequence numbers, record
12222 	 * its timestamp. NOTE: 1) That the test incorporates suggestions
12223 	 * from the latest proposal of the tcplw@cray.com list (Braden
12224 	 * 1993/04/26). 2) That updating only on newer timestamps interferes
12225 	 * with our earlier PAWS tests, so this check should be solely
12226 	 * predicated on the sequence space of this segment. 3) That we
12227 	 * modify the segment boundary check to be Last.ACK.Sent <= SEG.SEQ
12228 	 * + SEG.Len  instead of RFC1323's Last.ACK.Sent < SEG.SEQ +
12229 	 * SEG.Len, This modified check allows us to overcome RFC1323's
12230 	 * limitations as described in Stevens TCP/IP Illustrated Vol. 2
12231 	 * p.869. In such cases, we can still calculate the RTT correctly
12232 	 * when RCV.NXT == Last.ACK.Sent.
12233 	 */
12234 	if ((to->to_flags & TOF_TS) != 0 &&
12235 	    SEQ_LEQ(th->th_seq, tp->last_ack_sent) &&
12236 	    SEQ_LEQ(tp->last_ack_sent, th->th_seq + tlen +
12237 	    ((thflags & (TH_SYN | TH_FIN)) != 0))) {
12238 		tp->ts_recent_age = tcp_ts_getticks();
12239 		tp->ts_recent = to->to_tsval;
12240 	}
12241 	/*
12242 	 * If the ACK bit is off:  if in SYN-RECEIVED state or SENDSYN flag
12243 	 * is on (half-synchronized state), then queue data for later
12244 	 * processing; else drop segment and return.
12245 	 */
12246 	if ((thflags & TH_ACK) == 0) {
12247 		if (tp->t_flags & TF_NEEDSYN) {
12248 			return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
12249 			    tiwin, thflags, nxt_pkt));
12250 		} else if (tp->t_flags & TF_ACKNOW) {
12251 			ctf_do_dropafterack(m, tp, th, thflags, tlen, &ret_val);
12252 			((struct tcp_rack *)tp->t_fb_ptr)->r_wanted_output = 1;
12253 			return (ret_val);
12254 		} else {
12255 			ctf_do_drop(m, NULL);
12256 			return (0);
12257 		}
12258 	}
12259 	/*
12260 	 * case TCPS_LAST_ACK: Ack processing.
12261 	 */
12262 	if (rack_process_ack(m, th, so, tp, to, tiwin, tlen, &ourfinisacked, thflags, &ret_val)) {
12263 		return (ret_val);
12264 	}
12265 	if (ourfinisacked) {
12266 		tp = tcp_close(tp);
12267 		ctf_do_drop(m, tp);
12268 		return (1);
12269 	}
12270 	if (sbavail(&so->so_snd)) {
12271 		if (ctf_progress_timeout_check(tp, true)) {
12272 			rack_log_progress_event((struct tcp_rack *)tp->t_fb_ptr,
12273 						tp, tick, PROGRESS_DROP, __LINE__);
12274 			tcp_set_inp_to_drop(tp->t_inpcb, ETIMEDOUT);
12275 			ctf_do_dropwithreset(m, tp, th, BANDLIM_RST_OPENPORT, tlen);
12276 			return (1);
12277 		}
12278 	}
12279 	return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
12280 	    tiwin, thflags, nxt_pkt));
12281 }
12282 
12283 /*
12284  * Return value of 1, the TCB is unlocked and most
12285  * likely gone, return value of 0, the TCP is still
12286  * locked.
12287  */
12288 static int
12289 rack_do_fin_wait_2(struct mbuf *m, struct tcphdr *th, struct socket *so,
12290     struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen,
12291     uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos)
12292 {
12293 	int32_t ret_val = 0;
12294 	int32_t ourfinisacked = 0;
12295 	struct tcp_rack *rack;
12296 
12297 	rack = (struct tcp_rack *)tp->t_fb_ptr;
12298 	ctf_calc_rwin(so, tp);
12299 
12300 	/* Reset receive buffer auto scaling when not in bulk receive mode. */
12301 	if ((thflags & TH_RST) ||
12302 	    (tp->t_fin_is_rst && (thflags & TH_FIN)))
12303 		return (ctf_process_rst(m, th, so, tp));
12304 	/*
12305 	 * RFC5961 Section 4.2 Send challenge ACK for any SYN in
12306 	 * synchronized state.
12307 	 */
12308 	if (thflags & TH_SYN) {
12309 		ctf_challenge_ack(m, th, tp, &ret_val);
12310 		return (ret_val);
12311 	}
12312 	/*
12313 	 * RFC 1323 PAWS: If we have a timestamp reply on this segment and
12314 	 * it's less than ts_recent, drop it.
12315 	 */
12316 	if ((to->to_flags & TOF_TS) != 0 && tp->ts_recent &&
12317 	    TSTMP_LT(to->to_tsval, tp->ts_recent)) {
12318 		if (ctf_ts_check(m, th, tp, tlen, thflags, &ret_val))
12319 			return (ret_val);
12320 	}
12321 	if (_ctf_drop_checks(to, m, th, tp, &tlen, &thflags, &drop_hdrlen, &ret_val,
12322 			      &rack->r_ctl.challenge_ack_ts,
12323 			      &rack->r_ctl.challenge_ack_cnt)) {
12324 		return (ret_val);
12325 	}
12326 	/*
12327 	 * If new data are received on a connection after the user processes
12328 	 * are gone, then RST the other end.
12329 	 */
12330 	if ((so->so_state & SS_NOFDREF) &&
12331 	    tlen) {
12332 		if (rack_check_data_after_close(m, tp, &tlen, th, so))
12333 			return (1);
12334 	}
12335 	/*
12336 	 * If last ACK falls within this segment's sequence numbers, record
12337 	 * its timestamp. NOTE: 1) That the test incorporates suggestions
12338 	 * from the latest proposal of the tcplw@cray.com list (Braden
12339 	 * 1993/04/26). 2) That updating only on newer timestamps interferes
12340 	 * with our earlier PAWS tests, so this check should be solely
12341 	 * predicated on the sequence space of this segment. 3) That we
12342 	 * modify the segment boundary check to be Last.ACK.Sent <= SEG.SEQ
12343 	 * + SEG.Len  instead of RFC1323's Last.ACK.Sent < SEG.SEQ +
12344 	 * SEG.Len, This modified check allows us to overcome RFC1323's
12345 	 * limitations as described in Stevens TCP/IP Illustrated Vol. 2
12346 	 * p.869. In such cases, we can still calculate the RTT correctly
12347 	 * when RCV.NXT == Last.ACK.Sent.
12348 	 */
12349 	if ((to->to_flags & TOF_TS) != 0 &&
12350 	    SEQ_LEQ(th->th_seq, tp->last_ack_sent) &&
12351 	    SEQ_LEQ(tp->last_ack_sent, th->th_seq + tlen +
12352 	    ((thflags & (TH_SYN | TH_FIN)) != 0))) {
12353 		tp->ts_recent_age = tcp_ts_getticks();
12354 		tp->ts_recent = to->to_tsval;
12355 	}
12356 	/*
12357 	 * If the ACK bit is off:  if in SYN-RECEIVED state or SENDSYN flag
12358 	 * is on (half-synchronized state), then queue data for later
12359 	 * processing; else drop segment and return.
12360 	 */
12361 	if ((thflags & TH_ACK) == 0) {
12362 		if (tp->t_flags & TF_NEEDSYN) {
12363 			return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
12364 			    tiwin, thflags, nxt_pkt));
12365 		} else if (tp->t_flags & TF_ACKNOW) {
12366 			ctf_do_dropafterack(m, tp, th, thflags, tlen, &ret_val);
12367 			((struct tcp_rack *)tp->t_fb_ptr)->r_wanted_output = 1;
12368 			return (ret_val);
12369 		} else {
12370 			ctf_do_drop(m, NULL);
12371 			return (0);
12372 		}
12373 	}
12374 	/*
12375 	 * Ack processing.
12376 	 */
12377 	if (rack_process_ack(m, th, so, tp, to, tiwin, tlen, &ourfinisacked, thflags, &ret_val)) {
12378 		return (ret_val);
12379 	}
12380 	if (sbavail(&so->so_snd)) {
12381 		if (ctf_progress_timeout_check(tp, true)) {
12382 			rack_log_progress_event((struct tcp_rack *)tp->t_fb_ptr,
12383 						tp, tick, PROGRESS_DROP, __LINE__);
12384 			tcp_set_inp_to_drop(tp->t_inpcb, ETIMEDOUT);
12385 			ctf_do_dropwithreset(m, tp, th, BANDLIM_RST_OPENPORT, tlen);
12386 			return (1);
12387 		}
12388 	}
12389 	return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
12390 	    tiwin, thflags, nxt_pkt));
12391 }
12392 
12393 static void inline
12394 rack_clear_rate_sample(struct tcp_rack *rack)
12395 {
12396 	rack->r_ctl.rack_rs.rs_flags = RACK_RTT_EMPTY;
12397 	rack->r_ctl.rack_rs.rs_rtt_cnt = 0;
12398 	rack->r_ctl.rack_rs.rs_rtt_tot = 0;
12399 }
12400 
12401 static void
12402 rack_set_pace_segments(struct tcpcb *tp, struct tcp_rack *rack, uint32_t line, uint64_t *fill_override)
12403 {
12404 	uint64_t bw_est, rate_wanted;
12405 	int chged = 0;
12406 	uint32_t user_max, orig_min, orig_max;
12407 
12408 	orig_min = rack->r_ctl.rc_pace_min_segs;
12409 	orig_max = rack->r_ctl.rc_pace_max_segs;
12410 	user_max = ctf_fixed_maxseg(tp) * rack->rc_user_set_max_segs;
12411 	if (ctf_fixed_maxseg(tp) != rack->r_ctl.rc_pace_min_segs)
12412 		chged = 1;
12413 	rack->r_ctl.rc_pace_min_segs = ctf_fixed_maxseg(tp);
12414 	if (rack->use_fixed_rate || rack->rc_force_max_seg) {
12415 		if (user_max != rack->r_ctl.rc_pace_max_segs)
12416 			chged = 1;
12417 	}
12418 	if (rack->rc_force_max_seg) {
12419 		rack->r_ctl.rc_pace_max_segs = user_max;
12420 	} else if (rack->use_fixed_rate) {
12421 		bw_est = rack_get_bw(rack);
12422 		if ((rack->r_ctl.crte == NULL) ||
12423 		    (bw_est != rack->r_ctl.crte->rate)) {
12424 			rack->r_ctl.rc_pace_max_segs = user_max;
12425 		} else {
12426 			/* We are pacing right at the hardware rate */
12427 			uint32_t segsiz;
12428 
12429 			segsiz = min(ctf_fixed_maxseg(tp),
12430 				     rack->r_ctl.rc_pace_min_segs);
12431 			rack->r_ctl.rc_pace_max_segs = tcp_get_pacing_burst_size(
12432 				                           tp, bw_est, segsiz, 0,
12433 							   rack->r_ctl.crte, NULL);
12434 		}
12435 	} else if (rack->rc_always_pace) {
12436 		if (rack->r_ctl.gp_bw ||
12437 #ifdef NETFLIX_PEAKRATE
12438 		    rack->rc_tp->t_maxpeakrate ||
12439 #endif
12440 		    rack->r_ctl.init_rate) {
12441 			/* We have a rate of some sort set */
12442 			uint32_t  orig;
12443 
12444 			bw_est = rack_get_bw(rack);
12445 			orig = rack->r_ctl.rc_pace_max_segs;
12446 			if (fill_override)
12447 				rate_wanted = *fill_override;
12448 			else
12449 				rate_wanted = rack_get_output_bw(rack, bw_est, NULL, NULL);
12450 			if (rate_wanted) {
12451 				/* We have something */
12452 				rack->r_ctl.rc_pace_max_segs = rack_get_pacing_len(rack,
12453 										   rate_wanted,
12454 										   ctf_fixed_maxseg(rack->rc_tp));
12455 			} else
12456 				rack->r_ctl.rc_pace_max_segs = rack->r_ctl.rc_pace_min_segs;
12457 			if (orig != rack->r_ctl.rc_pace_max_segs)
12458 				chged = 1;
12459 		} else if ((rack->r_ctl.gp_bw == 0) &&
12460 			   (rack->r_ctl.rc_pace_max_segs == 0)) {
12461 			/*
12462 			 * If we have nothing limit us to bursting
12463 			 * out IW sized pieces.
12464 			 */
12465 			chged = 1;
12466 			rack->r_ctl.rc_pace_max_segs = rc_init_window(rack);
12467 		}
12468 	}
12469 	if (rack->r_ctl.rc_pace_max_segs > PACE_MAX_IP_BYTES) {
12470 		chged = 1;
12471 		rack->r_ctl.rc_pace_max_segs = PACE_MAX_IP_BYTES;
12472 	}
12473 	if (chged)
12474 		rack_log_type_pacing_sizes(tp, rack, orig_min, orig_max, line, 2);
12475 }
12476 
12477 
12478 static void
12479 rack_init_fsb_block(struct tcpcb *tp, struct tcp_rack *rack)
12480 {
12481 #ifdef INET6
12482 	struct ip6_hdr *ip6 = NULL;
12483 #endif
12484 #ifdef INET
12485 	struct ip *ip = NULL;
12486 #endif
12487 	struct udphdr *udp = NULL;
12488 
12489 	/* Ok lets fill in the fast block, it can only be used with no IP options! */
12490 #ifdef INET6
12491 	if (rack->r_is_v6) {
12492 		rack->r_ctl.fsb.tcp_ip_hdr_len = sizeof(struct ip6_hdr) + sizeof(struct tcphdr);
12493 		ip6 = (struct ip6_hdr *)rack->r_ctl.fsb.tcp_ip_hdr;
12494 		if (tp->t_port) {
12495 			rack->r_ctl.fsb.tcp_ip_hdr_len += sizeof(struct udphdr);
12496 			udp = (struct udphdr *)((caddr_t)ip6 + sizeof(struct ip6_hdr));
12497 			udp->uh_sport = htons(V_tcp_udp_tunneling_port);
12498 			udp->uh_dport = tp->t_port;
12499 			rack->r_ctl.fsb.udp = udp;
12500 			rack->r_ctl.fsb.th = (struct tcphdr *)(udp + 1);
12501 		} else
12502 		{
12503 			rack->r_ctl.fsb.th = (struct tcphdr *)(ip6 + 1);
12504 			rack->r_ctl.fsb.udp = NULL;
12505 		}
12506 		tcpip_fillheaders(rack->rc_inp,
12507 				  tp->t_port,
12508 				  ip6, rack->r_ctl.fsb.th);
12509 	} else
12510 #endif				/* INET6 */
12511 	{
12512 		rack->r_ctl.fsb.tcp_ip_hdr_len = sizeof(struct tcpiphdr);
12513 		ip = (struct ip *)rack->r_ctl.fsb.tcp_ip_hdr;
12514 		if (tp->t_port) {
12515 			rack->r_ctl.fsb.tcp_ip_hdr_len += sizeof(struct udphdr);
12516 			udp = (struct udphdr *)((caddr_t)ip + sizeof(struct ip));
12517 			udp->uh_sport = htons(V_tcp_udp_tunneling_port);
12518 			udp->uh_dport = tp->t_port;
12519 			rack->r_ctl.fsb.udp = udp;
12520 			rack->r_ctl.fsb.th = (struct tcphdr *)(udp + 1);
12521 		} else
12522 		{
12523 			rack->r_ctl.fsb.udp = NULL;
12524 			rack->r_ctl.fsb.th = (struct tcphdr *)(ip + 1);
12525 		}
12526 		tcpip_fillheaders(rack->rc_inp,
12527 				  tp->t_port,
12528 				  ip, rack->r_ctl.fsb.th);
12529 	}
12530 	rack->r_fsb_inited = 1;
12531 }
12532 
12533 static int
12534 rack_init_fsb(struct tcpcb *tp, struct tcp_rack *rack)
12535 {
12536 	/*
12537 	 * Allocate the larger of spaces V6 if available else just
12538 	 * V4 and include udphdr (overbook)
12539 	 */
12540 #ifdef INET6
12541 	rack->r_ctl.fsb.tcp_ip_hdr_len = sizeof(struct ip6_hdr) + sizeof(struct tcphdr) + sizeof(struct udphdr);
12542 #else
12543 	rack->r_ctl.fsb.tcp_ip_hdr_len = sizeof(struct tcpiphdr) + sizeof(struct udphdr);
12544 #endif
12545 	rack->r_ctl.fsb.tcp_ip_hdr = malloc(rack->r_ctl.fsb.tcp_ip_hdr_len,
12546 					    M_TCPFSB, M_NOWAIT|M_ZERO);
12547 	if (rack->r_ctl.fsb.tcp_ip_hdr == NULL) {
12548 		return (ENOMEM);
12549 	}
12550 	rack->r_fsb_inited = 0;
12551 	return (0);
12552 }
12553 
12554 static int
12555 rack_init(struct tcpcb *tp)
12556 {
12557 	struct tcp_rack *rack = NULL;
12558 	struct rack_sendmap *insret;
12559 	uint32_t iwin, snt, us_cts;
12560 	int err;
12561 
12562 	tp->t_fb_ptr = uma_zalloc(rack_pcb_zone, M_NOWAIT);
12563 	if (tp->t_fb_ptr == NULL) {
12564 		/*
12565 		 * We need to allocate memory but cant. The INP and INP_INFO
12566 		 * locks and they are recusive (happens during setup. So a
12567 		 * scheme to drop the locks fails :(
12568 		 *
12569 		 */
12570 		return (ENOMEM);
12571 	}
12572 	memset(tp->t_fb_ptr, 0, sizeof(struct tcp_rack));
12573 
12574 	rack = (struct tcp_rack *)tp->t_fb_ptr;
12575 	RB_INIT(&rack->r_ctl.rc_mtree);
12576 	TAILQ_INIT(&rack->r_ctl.rc_free);
12577 	TAILQ_INIT(&rack->r_ctl.rc_tmap);
12578 	rack->rc_tp = tp;
12579 	rack->rc_inp = tp->t_inpcb;
12580 	/* Set the flag */
12581 	rack->r_is_v6 = (tp->t_inpcb->inp_vflag & INP_IPV6) != 0;
12582 	/* Probably not needed but lets be sure */
12583 	rack_clear_rate_sample(rack);
12584 	/*
12585 	 * Save off the default values, socket options will poke
12586 	 * at these if pacing is not on or we have not yet
12587 	 * reached where pacing is on (gp_ready/fixed enabled).
12588 	 * When they get set into the CC module (when gp_ready
12589 	 * is enabled or we enable fixed) then we will set these
12590 	 * values into the CC and place in here the old values
12591 	 * so we have a restoral. Then we will set the flag
12592 	 * rc_pacing_cc_set. That way whenever we turn off pacing
12593 	 * or switch off this stack, we will know to go restore
12594 	 * the saved values.
12595 	 */
12596 	rack->r_ctl.rc_saved_beta.beta = V_newreno_beta_ecn;
12597 	rack->r_ctl.rc_saved_beta.beta_ecn = V_newreno_beta_ecn;
12598 	/* We want abe like behavior as well */
12599 	rack->r_ctl.rc_saved_beta.newreno_flags |= CC_NEWRENO_BETA_ECN_ENABLED;
12600 	rack->r_ctl.rc_reorder_fade = rack_reorder_fade;
12601 	rack->rc_allow_data_af_clo = rack_ignore_data_after_close;
12602 	rack->r_ctl.rc_tlp_threshold = rack_tlp_thresh;
12603 	rack->r_ctl.roundends = tp->snd_max;
12604 	if (use_rack_rr)
12605 		rack->use_rack_rr = 1;
12606 	if (V_tcp_delack_enabled)
12607 		tp->t_delayed_ack = 1;
12608 	else
12609 		tp->t_delayed_ack = 0;
12610 #ifdef TCP_ACCOUNTING
12611 	if (rack_tcp_accounting) {
12612 		tp->t_flags2 |= TF2_TCP_ACCOUNTING;
12613 	}
12614 #endif
12615 	if (rack_enable_shared_cwnd)
12616 		rack->rack_enable_scwnd = 1;
12617 	rack->rc_user_set_max_segs = rack_hptsi_segments;
12618 	rack->rc_force_max_seg = 0;
12619 	if (rack_use_imac_dack)
12620 		rack->rc_dack_mode = 1;
12621 	TAILQ_INIT(&rack->r_ctl.opt_list);
12622 	rack->r_ctl.rc_reorder_shift = rack_reorder_thresh;
12623 	rack->r_ctl.rc_pkt_delay = rack_pkt_delay;
12624 	rack->r_ctl.rc_tlp_cwnd_reduce = rack_lower_cwnd_at_tlp;
12625 	rack->r_ctl.rc_lowest_us_rtt = 0xffffffff;
12626 	rack->r_ctl.rc_highest_us_rtt = 0;
12627 	rack->r_ctl.bw_rate_cap = rack_bw_rate_cap;
12628 	rack->r_ctl.timer_slop = TICKS_2_USEC(tcp_rexmit_slop);
12629 	if (rack_use_cmp_acks)
12630 		rack->r_use_cmp_ack = 1;
12631 	if (rack_disable_prr)
12632 		rack->rack_no_prr = 1;
12633 	if (rack_gp_no_rec_chg)
12634 		rack->rc_gp_no_rec_chg = 1;
12635 	if (rack_pace_every_seg && tcp_can_enable_pacing()) {
12636 		rack->rc_always_pace = 1;
12637 		if (rack->use_fixed_rate || rack->gp_ready)
12638 			rack_set_cc_pacing(rack);
12639 	} else
12640 		rack->rc_always_pace = 0;
12641 	if (rack_enable_mqueue_for_nonpaced || rack->r_use_cmp_ack)
12642 		rack->r_mbuf_queue = 1;
12643 	else
12644 		rack->r_mbuf_queue = 0;
12645 	if  (rack->r_mbuf_queue || rack->rc_always_pace || rack->r_use_cmp_ack)
12646 		tp->t_inpcb->inp_flags2 |= INP_SUPPORTS_MBUFQ;
12647 	else
12648 		tp->t_inpcb->inp_flags2 &= ~INP_SUPPORTS_MBUFQ;
12649 	rack_set_pace_segments(tp, rack, __LINE__, NULL);
12650 	if (rack_limits_scwnd)
12651 		rack->r_limit_scw = 1;
12652 	else
12653 		rack->r_limit_scw = 0;
12654 	rack->rc_labc = V_tcp_abc_l_var;
12655 	rack->r_ctl.rc_high_rwnd = tp->snd_wnd;
12656 	rack->r_ctl.cwnd_to_use = tp->snd_cwnd;
12657 	rack->r_ctl.rc_rate_sample_method = rack_rate_sample_method;
12658 	rack->rack_tlp_threshold_use = rack_tlp_threshold_use;
12659 	rack->r_ctl.rc_prr_sendalot = rack_send_a_lot_in_prr;
12660 	rack->r_ctl.rc_min_to = rack_min_to;
12661 	microuptime(&rack->r_ctl.act_rcv_time);
12662 	rack->r_ctl.rc_last_time_decay = rack->r_ctl.act_rcv_time;
12663 	rack->r_running_late = 0;
12664 	rack->r_running_early = 0;
12665 	rack->rc_init_win = rack_default_init_window;
12666 	rack->r_ctl.rack_per_of_gp_ss = rack_per_of_gp_ss;
12667 	if (rack_hw_up_only)
12668 		rack->r_up_only = 1;
12669 	if (rack_do_dyn_mul) {
12670 		/* When dynamic adjustment is on CA needs to start at 100% */
12671 		rack->rc_gp_dyn_mul = 1;
12672 		if (rack_do_dyn_mul >= 100)
12673 			rack->r_ctl.rack_per_of_gp_ca = rack_do_dyn_mul;
12674 	} else
12675 		rack->r_ctl.rack_per_of_gp_ca = rack_per_of_gp_ca;
12676 	rack->r_ctl.rack_per_of_gp_rec = rack_per_of_gp_rec;
12677 	rack->r_ctl.rack_per_of_gp_probertt = rack_per_of_gp_probertt;
12678 	rack->r_ctl.rc_tlp_rxt_last_time = tcp_tv_to_mssectick(&rack->r_ctl.act_rcv_time);
12679 	setup_time_filter_small(&rack->r_ctl.rc_gp_min_rtt, FILTER_TYPE_MIN,
12680 				rack_probertt_filter_life);
12681 	us_cts = tcp_tv_to_usectick(&rack->r_ctl.act_rcv_time);
12682 	rack->r_ctl.rc_lower_rtt_us_cts = us_cts;
12683 	rack->r_ctl.rc_time_of_last_probertt = us_cts;
12684 	rack->r_ctl.challenge_ack_ts = tcp_ts_getticks();
12685 	rack->r_ctl.rc_time_probertt_starts = 0;
12686 	if (rack_dsack_std_based & 0x1) {
12687 		/* Basically this means all rack timers are at least (srtt + 1/4 srtt) */
12688 		rack->rc_rack_tmr_std_based = 1;
12689 	}
12690 	if (rack_dsack_std_based & 0x2) {
12691 		/* Basically this means  rack timers are extended based on dsack by up to (2 * srtt) */
12692 		rack->rc_rack_use_dsack = 1;
12693 	}
12694 	/* We require at least one measurement, even if the sysctl is 0 */
12695 	if (rack_req_measurements)
12696 		rack->r_ctl.req_measurements = rack_req_measurements;
12697 	else
12698 		rack->r_ctl.req_measurements = 1;
12699 	if (rack_enable_hw_pacing)
12700 		rack->rack_hdw_pace_ena = 1;
12701 	if (rack_hw_rate_caps)
12702 		rack->r_rack_hw_rate_caps = 1;
12703 	/* Do we force on detection? */
12704 #ifdef NETFLIX_EXP_DETECTION
12705 	if (tcp_force_detection)
12706 		rack->do_detection = 1;
12707 	else
12708 #endif
12709 		rack->do_detection = 0;
12710 	if (rack_non_rxt_use_cr)
12711 		rack->rack_rec_nonrxt_use_cr = 1;
12712 	err = rack_init_fsb(tp, rack);
12713 	if (err) {
12714 		uma_zfree(rack_pcb_zone, tp->t_fb_ptr);
12715 		tp->t_fb_ptr = NULL;
12716 		return (err);
12717 	}
12718 	if (tp->snd_una != tp->snd_max) {
12719 		/* Create a send map for the current outstanding data */
12720 		struct rack_sendmap *rsm;
12721 
12722 		rsm = rack_alloc(rack);
12723 		if (rsm == NULL) {
12724 			uma_zfree(rack_pcb_zone, tp->t_fb_ptr);
12725 			tp->t_fb_ptr = NULL;
12726 			return (ENOMEM);
12727 		}
12728 		rsm->r_no_rtt_allowed = 1;
12729 		rsm->r_tim_lastsent[0] = rack_to_usec_ts(&rack->r_ctl.act_rcv_time);
12730 		rsm->r_rtr_cnt = 1;
12731 		rsm->r_rtr_bytes = 0;
12732 		if (tp->t_flags & TF_SENTFIN) {
12733 			rsm->r_end = tp->snd_max - 1;
12734 			rsm->r_flags |= RACK_HAS_FIN;
12735 		} else {
12736 			rsm->r_end = tp->snd_max;
12737 		}
12738 		if (tp->snd_una == tp->iss) {
12739 			/* The data space is one beyond snd_una */
12740 			rsm->r_flags |= RACK_HAS_SYN;
12741 			rsm->r_start = tp->iss;
12742 			rsm->r_end = rsm->r_start + (tp->snd_max - tp->snd_una);
12743 		} else
12744 			rsm->r_start = tp->snd_una;
12745 		rsm->r_dupack = 0;
12746 		if (rack->rc_inp->inp_socket->so_snd.sb_mb != NULL) {
12747 			rsm->m = sbsndmbuf(&rack->rc_inp->inp_socket->so_snd, 0, &rsm->soff);
12748 			if (rsm->m)
12749 				rsm->orig_m_len = rsm->m->m_len;
12750 			else
12751 				rsm->orig_m_len = 0;
12752 		} else {
12753 			/*
12754 			 * This can happen if we have a stand-alone FIN or
12755 			 *  SYN.
12756 			 */
12757 			rsm->m = NULL;
12758 			rsm->orig_m_len = 0;
12759 			rsm->soff = 0;
12760 		}
12761 		insret = RB_INSERT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm);
12762 #ifdef INVARIANTS
12763 		if (insret != NULL) {
12764 			panic("Insert in rb tree fails ret:%p rack:%p rsm:%p",
12765 			      insret, rack, rsm);
12766 		}
12767 #endif
12768 		TAILQ_INSERT_TAIL(&rack->r_ctl.rc_tmap, rsm, r_tnext);
12769 		rsm->r_in_tmap = 1;
12770 	}
12771 	/*
12772 	 * Timers in Rack are kept in microseconds so lets
12773 	 * convert any initial incoming variables
12774 	 * from ticks into usecs. Note that we
12775 	 * also change the values of t_srtt and t_rttvar, if
12776 	 * they are non-zero. They are kept with a 5
12777 	 * bit decimal so we have to carefully convert
12778 	 * these to get the full precision.
12779 	 */
12780 	rack_convert_rtts(tp);
12781 	tp->t_rttlow = TICKS_2_USEC(tp->t_rttlow);
12782 	if (rack_do_hystart) {
12783 		struct sockopt sopt;
12784 		struct cc_newreno_opts opt;
12785 
12786 		sopt.sopt_valsize = sizeof(struct cc_newreno_opts);
12787 		sopt.sopt_dir = SOPT_SET;
12788 		opt.name = CC_NEWRENO_ENABLE_HYSTART;
12789 		opt.val = rack_do_hystart;
12790 		if (CC_ALGO(tp)->ctl_output != NULL)
12791 			(void)CC_ALGO(tp)->ctl_output(tp->ccv, &sopt, &opt);
12792 	}
12793 	if (rack_def_profile)
12794 		rack_set_profile(rack, rack_def_profile);
12795 	/* Cancel the GP measurement in progress */
12796 	tp->t_flags &= ~TF_GPUTINPROG;
12797 	if (SEQ_GT(tp->snd_max, tp->iss))
12798 		snt = tp->snd_max - tp->iss;
12799 	else
12800 		snt = 0;
12801 	iwin = rc_init_window(rack);
12802 	if (snt < iwin) {
12803 		/* We are not past the initial window
12804 		 * so we need to make sure cwnd is
12805 		 * correct.
12806 		 */
12807 		if (tp->snd_cwnd < iwin)
12808 			tp->snd_cwnd = iwin;
12809 		/*
12810 		 * If we are within the initial window
12811 		 * we want ssthresh to be unlimited. Setting
12812 		 * it to the rwnd (which the default stack does
12813 		 * and older racks) is not really a good idea
12814 		 * since we want to be in SS and grow both the
12815 		 * cwnd and the rwnd (via dynamic rwnd growth). If
12816 		 * we set it to the rwnd then as the peer grows its
12817 		 * rwnd we will be stuck in CA and never hit SS.
12818 		 *
12819 		 * Its far better to raise it up high (this takes the
12820 		 * risk that there as been a loss already, probably
12821 		 * we should have an indicator in all stacks of loss
12822 		 * but we don't), but considering the normal use this
12823 		 * is a risk worth taking. The consequences of not
12824 		 * hitting SS are far worse than going one more time
12825 		 * into it early on (before we have sent even a IW).
12826 		 * It is highly unlikely that we will have had a loss
12827 		 * before getting the IW out.
12828 		 */
12829 		tp->snd_ssthresh = 0xffffffff;
12830 	}
12831 	rack_stop_all_timers(tp);
12832 	/* Lets setup the fsb block */
12833 	rack_start_hpts_timer(rack, tp, tcp_get_usecs(NULL), 0, 0, 0);
12834 	rack_log_rtt_shrinks(rack,  us_cts,  tp->t_rxtcur,
12835 			     __LINE__, RACK_RTTS_INIT);
12836 	return (0);
12837 }
12838 
12839 static int
12840 rack_handoff_ok(struct tcpcb *tp)
12841 {
12842 	if ((tp->t_state == TCPS_CLOSED) ||
12843 	    (tp->t_state == TCPS_LISTEN)) {
12844 		/* Sure no problem though it may not stick */
12845 		return (0);
12846 	}
12847 	if ((tp->t_state == TCPS_SYN_SENT) ||
12848 	    (tp->t_state == TCPS_SYN_RECEIVED)) {
12849 		/*
12850 		 * We really don't know if you support sack,
12851 		 * you have to get to ESTAB or beyond to tell.
12852 		 */
12853 		return (EAGAIN);
12854 	}
12855 	if ((tp->t_flags & TF_SENTFIN) && ((tp->snd_max - tp->snd_una) > 1)) {
12856 		/*
12857 		 * Rack will only send a FIN after all data is acknowledged.
12858 		 * So in this case we have more data outstanding. We can't
12859 		 * switch stacks until either all data and only the FIN
12860 		 * is left (in which case rack_init() now knows how
12861 		 * to deal with that) <or> all is acknowledged and we
12862 		 * are only left with incoming data, though why you
12863 		 * would want to switch to rack after all data is acknowledged
12864 		 * I have no idea (rrs)!
12865 		 */
12866 		return (EAGAIN);
12867 	}
12868 	if ((tp->t_flags & TF_SACK_PERMIT) || rack_sack_not_required){
12869 		return (0);
12870 	}
12871 	/*
12872 	 * If we reach here we don't do SACK on this connection so we can
12873 	 * never do rack.
12874 	 */
12875 	return (EINVAL);
12876 }
12877 
12878 
12879 static void
12880 rack_fini(struct tcpcb *tp, int32_t tcb_is_purged)
12881 {
12882 	int ack_cmp = 0;
12883 
12884 	if (tp->t_fb_ptr) {
12885 		struct tcp_rack *rack;
12886 		struct rack_sendmap *rsm, *nrsm, *rm;
12887 
12888 		rack = (struct tcp_rack *)tp->t_fb_ptr;
12889 		if (tp->t_in_pkt) {
12890 			/*
12891 			 * It is unsafe to process the packets since a
12892 			 * reset may be lurking in them (its rare but it
12893 			 * can occur). If we were to find a RST, then we
12894 			 * would end up dropping the connection and the
12895 			 * INP lock, so when we return the caller (tcp_usrreq)
12896 			 * will blow up when it trys to unlock the inp.
12897 			 */
12898 			struct mbuf *save, *m;
12899 
12900 			m = tp->t_in_pkt;
12901 			tp->t_in_pkt = NULL;
12902 			tp->t_tail_pkt = NULL;
12903 			while (m) {
12904 				save = m->m_nextpkt;
12905 				m->m_nextpkt = NULL;
12906 				m_freem(m);
12907 				m = save;
12908 			}
12909 			if ((tp->t_inpcb) &&
12910 			    (tp->t_inpcb->inp_flags2 & INP_MBUF_ACKCMP))
12911 				ack_cmp = 1;
12912 			if (ack_cmp) {
12913 				/* Total if we used large or small (if ack-cmp was used). */
12914 				if (rack->rc_inp->inp_flags2 & INP_MBUF_L_ACKS)
12915 					counter_u64_add(rack_large_ackcmp, 1);
12916 				else
12917 					counter_u64_add(rack_small_ackcmp, 1);
12918 			}
12919 		}
12920 		tp->t_flags &= ~TF_FORCEDATA;
12921 #ifdef NETFLIX_SHARED_CWND
12922 		if (rack->r_ctl.rc_scw) {
12923 			uint32_t limit;
12924 
12925 			if (rack->r_limit_scw)
12926 				limit = max(1, rack->r_ctl.rc_lowest_us_rtt);
12927 			else
12928 				limit = 0;
12929 			tcp_shared_cwnd_free_full(tp, rack->r_ctl.rc_scw,
12930 						  rack->r_ctl.rc_scw_index,
12931 						  limit);
12932 			rack->r_ctl.rc_scw = NULL;
12933 		}
12934 #endif
12935 		if (rack->r_ctl.fsb.tcp_ip_hdr) {
12936 			free(rack->r_ctl.fsb.tcp_ip_hdr, M_TCPFSB);
12937 			rack->r_ctl.fsb.tcp_ip_hdr = NULL;
12938 			rack->r_ctl.fsb.th = NULL;
12939 		}
12940 		/* Convert back to ticks, with  */
12941 		if (tp->t_srtt > 1) {
12942 			uint32_t val, frac;
12943 
12944 			val = USEC_2_TICKS(tp->t_srtt);
12945 			frac = tp->t_srtt % (HPTS_USEC_IN_SEC / hz);
12946 			tp->t_srtt = val << TCP_RTT_SHIFT;
12947 			/*
12948 			 * frac is the fractional part here is left
12949 			 * over from converting to hz and shifting.
12950 			 * We need to convert this to the 5 bit
12951 			 * remainder.
12952 			 */
12953 			if (frac) {
12954 				if (hz == 1000) {
12955 					frac = (((uint64_t)frac *  (uint64_t)TCP_RTT_SCALE) / (uint64_t)HPTS_USEC_IN_MSEC);
12956 				} else {
12957 					frac = (((uint64_t)frac * (uint64_t)(hz) * (uint64_t)TCP_RTT_SCALE) /(uint64_t)HPTS_USEC_IN_SEC);
12958 				}
12959 				tp->t_srtt += frac;
12960 			}
12961 		}
12962 		if (tp->t_rttvar) {
12963 			uint32_t val, frac;
12964 
12965 			val = USEC_2_TICKS(tp->t_rttvar);
12966 			frac = tp->t_srtt % (HPTS_USEC_IN_SEC / hz);
12967 			tp->t_rttvar = val <<  TCP_RTTVAR_SHIFT;
12968 			/*
12969 			 * frac is the fractional part here is left
12970 			 * over from converting to hz and shifting.
12971 			 * We need to convert this to the 5 bit
12972 			 * remainder.
12973 			 */
12974 			if (frac) {
12975 				if (hz == 1000) {
12976 					frac = (((uint64_t)frac *  (uint64_t)TCP_RTT_SCALE) / (uint64_t)HPTS_USEC_IN_MSEC);
12977 				} else {
12978 					frac = (((uint64_t)frac * (uint64_t)(hz) * (uint64_t)TCP_RTT_SCALE) /(uint64_t)HPTS_USEC_IN_SEC);
12979 				}
12980 				tp->t_rttvar += frac;
12981 			}
12982 		}
12983 		tp->t_rxtcur = USEC_2_TICKS(tp->t_rxtcur);
12984 		tp->t_rttlow = USEC_2_TICKS(tp->t_rttlow);
12985 		if (rack->rc_always_pace) {
12986 			tcp_decrement_paced_conn();
12987 			rack_undo_cc_pacing(rack);
12988 			rack->rc_always_pace = 0;
12989 		}
12990 		/* Clean up any options if they were not applied */
12991 		while (!TAILQ_EMPTY(&rack->r_ctl.opt_list)) {
12992 			struct deferred_opt_list *dol;
12993 
12994 			dol = TAILQ_FIRST(&rack->r_ctl.opt_list);
12995 			TAILQ_REMOVE(&rack->r_ctl.opt_list, dol, next);
12996 			free(dol, M_TCPDO);
12997 		}
12998 		/* rack does not use force data but other stacks may clear it */
12999 		if (rack->r_ctl.crte != NULL) {
13000 			tcp_rel_pacing_rate(rack->r_ctl.crte, tp);
13001 			rack->rack_hdrw_pacing = 0;
13002 			rack->r_ctl.crte = NULL;
13003 		}
13004 #ifdef TCP_BLACKBOX
13005 		tcp_log_flowend(tp);
13006 #endif
13007 		RB_FOREACH_SAFE(rsm, rack_rb_tree_head, &rack->r_ctl.rc_mtree, nrsm) {
13008 			rm = RB_REMOVE(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm);
13009 #ifdef INVARIANTS
13010 			if (rm != rsm) {
13011 				panic("At fini, rack:%p rsm:%p rm:%p",
13012 				      rack, rsm, rm);
13013 			}
13014 #endif
13015 			uma_zfree(rack_zone, rsm);
13016 		}
13017 		rsm = TAILQ_FIRST(&rack->r_ctl.rc_free);
13018 		while (rsm) {
13019 			TAILQ_REMOVE(&rack->r_ctl.rc_free, rsm, r_tnext);
13020 			uma_zfree(rack_zone, rsm);
13021 			rsm = TAILQ_FIRST(&rack->r_ctl.rc_free);
13022 		}
13023 		rack->rc_free_cnt = 0;
13024 		uma_zfree(rack_pcb_zone, tp->t_fb_ptr);
13025 		tp->t_fb_ptr = NULL;
13026 	}
13027 	if (tp->t_inpcb) {
13028 		tp->t_inpcb->inp_flags2 &= ~INP_SUPPORTS_MBUFQ;
13029 		tp->t_inpcb->inp_flags2 &= ~INP_MBUF_QUEUE_READY;
13030 		tp->t_inpcb->inp_flags2 &= ~INP_DONT_SACK_QUEUE;
13031 		tp->t_inpcb->inp_flags2 &= ~INP_MBUF_ACKCMP;
13032 		/* Cancel the GP measurement in progress */
13033 		tp->t_flags &= ~TF_GPUTINPROG;
13034 		tp->t_inpcb->inp_flags2 &= ~INP_MBUF_L_ACKS;
13035 	}
13036 	/* Make sure snd_nxt is correctly set */
13037 	tp->snd_nxt = tp->snd_max;
13038 }
13039 
13040 static void
13041 rack_set_state(struct tcpcb *tp, struct tcp_rack *rack)
13042 {
13043 	if ((rack->r_state == TCPS_CLOSED) && (tp->t_state != TCPS_CLOSED)) {
13044 		rack->r_is_v6 = (tp->t_inpcb->inp_vflag & INP_IPV6) != 0;
13045 	}
13046 	switch (tp->t_state) {
13047 	case TCPS_SYN_SENT:
13048 		rack->r_state = TCPS_SYN_SENT;
13049 		rack->r_substate = rack_do_syn_sent;
13050 		break;
13051 	case TCPS_SYN_RECEIVED:
13052 		rack->r_state = TCPS_SYN_RECEIVED;
13053 		rack->r_substate = rack_do_syn_recv;
13054 		break;
13055 	case TCPS_ESTABLISHED:
13056 		rack_set_pace_segments(tp, rack, __LINE__, NULL);
13057 		rack->r_state = TCPS_ESTABLISHED;
13058 		rack->r_substate = rack_do_established;
13059 		break;
13060 	case TCPS_CLOSE_WAIT:
13061 		rack_set_pace_segments(tp, rack, __LINE__, NULL);
13062 		rack->r_state = TCPS_CLOSE_WAIT;
13063 		rack->r_substate = rack_do_close_wait;
13064 		break;
13065 	case TCPS_FIN_WAIT_1:
13066 		rack_set_pace_segments(tp, rack, __LINE__, NULL);
13067 		rack->r_state = TCPS_FIN_WAIT_1;
13068 		rack->r_substate = rack_do_fin_wait_1;
13069 		break;
13070 	case TCPS_CLOSING:
13071 		rack_set_pace_segments(tp, rack, __LINE__, NULL);
13072 		rack->r_state = TCPS_CLOSING;
13073 		rack->r_substate = rack_do_closing;
13074 		break;
13075 	case TCPS_LAST_ACK:
13076 		rack_set_pace_segments(tp, rack, __LINE__, NULL);
13077 		rack->r_state = TCPS_LAST_ACK;
13078 		rack->r_substate = rack_do_lastack;
13079 		break;
13080 	case TCPS_FIN_WAIT_2:
13081 		rack_set_pace_segments(tp, rack, __LINE__, NULL);
13082 		rack->r_state = TCPS_FIN_WAIT_2;
13083 		rack->r_substate = rack_do_fin_wait_2;
13084 		break;
13085 	case TCPS_LISTEN:
13086 	case TCPS_CLOSED:
13087 	case TCPS_TIME_WAIT:
13088 	default:
13089 		break;
13090 	};
13091 	if (rack->r_use_cmp_ack && TCPS_HAVEESTABLISHED(tp->t_state))
13092 		rack->rc_inp->inp_flags2 |= INP_MBUF_ACKCMP;
13093 
13094 }
13095 
13096 static void
13097 rack_timer_audit(struct tcpcb *tp, struct tcp_rack *rack, struct sockbuf *sb)
13098 {
13099 	/*
13100 	 * We received an ack, and then did not
13101 	 * call send or were bounced out due to the
13102 	 * hpts was running. Now a timer is up as well, is
13103 	 * it the right timer?
13104 	 */
13105 	struct rack_sendmap *rsm;
13106 	int tmr_up;
13107 
13108 	tmr_up = rack->r_ctl.rc_hpts_flags & PACE_TMR_MASK;
13109 	if (rack->rc_in_persist && (tmr_up == PACE_TMR_PERSIT))
13110 		return;
13111 	rsm = TAILQ_FIRST(&rack->r_ctl.rc_tmap);
13112 	if (((rsm == NULL) || (tp->t_state < TCPS_ESTABLISHED)) &&
13113 	    (tmr_up == PACE_TMR_RXT)) {
13114 		/* Should be an RXT */
13115 		return;
13116 	}
13117 	if (rsm == NULL) {
13118 		/* Nothing outstanding? */
13119 		if (tp->t_flags & TF_DELACK) {
13120 			if (tmr_up == PACE_TMR_DELACK)
13121 				/* We are supposed to have delayed ack up and we do */
13122 				return;
13123 		} else if (sbavail(&tp->t_inpcb->inp_socket->so_snd) && (tmr_up == PACE_TMR_RXT)) {
13124 			/*
13125 			 * if we hit enobufs then we would expect the possiblity
13126 			 * of nothing outstanding and the RXT up (and the hptsi timer).
13127 			 */
13128 			return;
13129 		} else if (((V_tcp_always_keepalive ||
13130 			     rack->rc_inp->inp_socket->so_options & SO_KEEPALIVE) &&
13131 			    (tp->t_state <= TCPS_CLOSING)) &&
13132 			   (tmr_up == PACE_TMR_KEEP) &&
13133 			   (tp->snd_max == tp->snd_una)) {
13134 			/* We should have keep alive up and we do */
13135 			return;
13136 		}
13137 	}
13138 	if (SEQ_GT(tp->snd_max, tp->snd_una) &&
13139 		   ((tmr_up == PACE_TMR_TLP) ||
13140 		    (tmr_up == PACE_TMR_RACK) ||
13141 		    (tmr_up == PACE_TMR_RXT))) {
13142 		/*
13143 		 * Either a Rack, TLP or RXT is fine if  we
13144 		 * have outstanding data.
13145 		 */
13146 		return;
13147 	} else if (tmr_up == PACE_TMR_DELACK) {
13148 		/*
13149 		 * If the delayed ack was going to go off
13150 		 * before the rtx/tlp/rack timer were going to
13151 		 * expire, then that would be the timer in control.
13152 		 * Note we don't check the time here trusting the
13153 		 * code is correct.
13154 		 */
13155 		return;
13156 	}
13157 	/*
13158 	 * Ok the timer originally started is not what we want now.
13159 	 * We will force the hpts to be stopped if any, and restart
13160 	 * with the slot set to what was in the saved slot.
13161 	 */
13162 	if (rack->rc_inp->inp_in_hpts) {
13163 		if (rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT) {
13164 			uint32_t us_cts;
13165 
13166 			us_cts = tcp_get_usecs(NULL);
13167 			if (TSTMP_GT(rack->r_ctl.rc_last_output_to, us_cts)) {
13168 				rack->r_early = 1;
13169 				rack->r_ctl.rc_agg_early += (rack->r_ctl.rc_last_output_to - us_cts);
13170 			}
13171 			rack->r_ctl.rc_hpts_flags &= ~PACE_PKT_OUTPUT;
13172 		}
13173 		tcp_hpts_remove(tp->t_inpcb, HPTS_REMOVE_OUTPUT);
13174 	}
13175 	rack_timer_cancel(tp, rack, rack->r_ctl.rc_rcvtime, __LINE__);
13176 	rack_start_hpts_timer(rack, tp, tcp_get_usecs(NULL), 0, 0, 0);
13177 }
13178 
13179 
13180 static void
13181 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)
13182 {
13183 	if ((SEQ_LT(tp->snd_wl1, seq) ||
13184 	    (tp->snd_wl1 == seq && (SEQ_LT(tp->snd_wl2, ack) ||
13185 	    (tp->snd_wl2 == ack && tiwin > tp->snd_wnd))))) {
13186 		/* keep track of pure window updates */
13187 		if ((tp->snd_wl2 == ack) && (tiwin > tp->snd_wnd))
13188 			KMOD_TCPSTAT_INC(tcps_rcvwinupd);
13189 		tp->snd_wnd = tiwin;
13190 		rack_validate_fo_sendwin_up(tp, rack);
13191 		tp->snd_wl1 = seq;
13192 		tp->snd_wl2 = ack;
13193 		if (tp->snd_wnd > tp->max_sndwnd)
13194 			tp->max_sndwnd = tp->snd_wnd;
13195 	    rack->r_wanted_output = 1;
13196 	} else if ((tp->snd_wl2 == ack) && (tiwin < tp->snd_wnd)) {
13197 		tp->snd_wnd = tiwin;
13198 		rack_validate_fo_sendwin_up(tp, rack);
13199 		tp->snd_wl1 = seq;
13200 		tp->snd_wl2 = ack;
13201 	} else {
13202 		/* Not a valid win update */
13203 		return;
13204 	}
13205 	if (tp->snd_wnd > tp->max_sndwnd)
13206 		tp->max_sndwnd = tp->snd_wnd;
13207 	if (tp->snd_wnd < (tp->snd_max - high_seq)) {
13208 		/* The peer collapsed the window */
13209 		rack_collapsed_window(rack);
13210 	} else if (rack->rc_has_collapsed)
13211 		rack_un_collapse_window(rack);
13212 	/* Do we exit persists? */
13213 	if ((rack->rc_in_persist != 0) &&
13214 	    (tp->snd_wnd >= min((rack->r_ctl.rc_high_rwnd/2),
13215 				rack->r_ctl.rc_pace_min_segs))) {
13216 		rack_exit_persist(tp, rack, cts);
13217 	}
13218 	/* Do we enter persists? */
13219 	if ((rack->rc_in_persist == 0) &&
13220 	    (tp->snd_wnd < min((rack->r_ctl.rc_high_rwnd/2), rack->r_ctl.rc_pace_min_segs)) &&
13221 	    TCPS_HAVEESTABLISHED(tp->t_state) &&
13222 	    (tp->snd_max == tp->snd_una) &&
13223 	    sbavail(&tp->t_inpcb->inp_socket->so_snd) &&
13224 	    (sbavail(&tp->t_inpcb->inp_socket->so_snd) > tp->snd_wnd)) {
13225 		/*
13226 		 * Here the rwnd is less than
13227 		 * the pacing size, we are established,
13228 		 * nothing is outstanding, and there is
13229 		 * data to send. Enter persists.
13230 		 */
13231 		rack_enter_persist(tp, rack, rack->r_ctl.rc_rcvtime);
13232 	}
13233 }
13234 
13235 static void
13236 rack_log_input_packet(struct tcpcb *tp, struct tcp_rack *rack, struct tcp_ackent *ae, int ackval, uint32_t high_seq)
13237 {
13238 
13239 	if (tp->t_logstate != TCP_LOG_STATE_OFF) {
13240 		union tcp_log_stackspecific log;
13241 		struct timeval ltv;
13242 		char tcp_hdr_buf[60];
13243 		struct tcphdr *th;
13244 		struct timespec ts;
13245 		uint32_t orig_snd_una;
13246 		uint8_t xx = 0;
13247 
13248 #ifdef NETFLIX_HTTP_LOGGING
13249 		struct http_sendfile_track *http_req;
13250 
13251 		if (SEQ_GT(ae->ack, tp->snd_una)) {
13252 			http_req = tcp_http_find_req_for_seq(tp, (ae->ack-1));
13253 		} else {
13254 			http_req = tcp_http_find_req_for_seq(tp, ae->ack);
13255 		}
13256 #endif
13257 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
13258 		log.u_bbr.inhpts = rack->rc_inp->inp_in_hpts;
13259 		log.u_bbr.ininput = rack->rc_inp->inp_in_input;
13260 		if (rack->rack_no_prr == 0)
13261 			log.u_bbr.flex1 = rack->r_ctl.rc_prr_sndcnt;
13262 		else
13263 			log.u_bbr.flex1 = 0;
13264 		log.u_bbr.use_lt_bw = rack->r_ent_rec_ns;
13265 		log.u_bbr.use_lt_bw <<= 1;
13266 		log.u_bbr.use_lt_bw |= rack->r_might_revert;
13267 		log.u_bbr.flex2 = rack->r_ctl.rc_num_maps_alloced;
13268 		log.u_bbr.inflight = ctf_flight_size(tp, rack->r_ctl.rc_sacked);
13269 		log.u_bbr.pkts_out = tp->t_maxseg;
13270 		log.u_bbr.flex4 = rack->r_ctl.rc_hpts_flags;
13271 		log.u_bbr.flex7 = 1;
13272 		log.u_bbr.lost = ae->flags;
13273 		log.u_bbr.cwnd_gain = ackval;
13274 		log.u_bbr.pacing_gain = 0x2;
13275 		if (ae->flags & TSTMP_HDWR) {
13276 			/* Record the hardware timestamp if present */
13277 			log.u_bbr.flex3 = M_TSTMP;
13278 			ts.tv_sec = ae->timestamp / 1000000000;
13279 			ts.tv_nsec = ae->timestamp % 1000000000;
13280 			ltv.tv_sec = ts.tv_sec;
13281 			ltv.tv_usec = ts.tv_nsec / 1000;
13282 			log.u_bbr.lt_epoch = tcp_tv_to_usectick(&ltv);
13283 		} else if (ae->flags & TSTMP_LRO) {
13284 			/* Record the LRO the arrival timestamp */
13285 			log.u_bbr.flex3 = M_TSTMP_LRO;
13286 			ts.tv_sec = ae->timestamp / 1000000000;
13287 			ts.tv_nsec = ae->timestamp % 1000000000;
13288 			ltv.tv_sec = ts.tv_sec;
13289 			ltv.tv_usec = ts.tv_nsec / 1000;
13290 			log.u_bbr.flex5 = tcp_tv_to_usectick(&ltv);
13291 		}
13292 		log.u_bbr.timeStamp = tcp_get_usecs(&ltv);
13293 		/* Log the rcv time */
13294 		log.u_bbr.delRate = ae->timestamp;
13295 #ifdef NETFLIX_HTTP_LOGGING
13296 		log.u_bbr.applimited = tp->t_http_closed;
13297 		log.u_bbr.applimited <<= 8;
13298 		log.u_bbr.applimited |= tp->t_http_open;
13299 		log.u_bbr.applimited <<= 8;
13300 		log.u_bbr.applimited |= tp->t_http_req;
13301 		if (http_req) {
13302 			/* Copy out any client req info */
13303 			/* seconds */
13304 			log.u_bbr.pkt_epoch = (http_req->localtime / HPTS_USEC_IN_SEC);
13305 			/* useconds */
13306 			log.u_bbr.delivered = (http_req->localtime % HPTS_USEC_IN_SEC);
13307 			log.u_bbr.rttProp = http_req->timestamp;
13308 			log.u_bbr.cur_del_rate = http_req->start;
13309 			if (http_req->flags & TCP_HTTP_TRACK_FLG_OPEN) {
13310 				log.u_bbr.flex8 |= 1;
13311 			} else {
13312 				log.u_bbr.flex8 |= 2;
13313 				log.u_bbr.bw_inuse = http_req->end;
13314 			}
13315 			log.u_bbr.flex6 = http_req->start_seq;
13316 			if (http_req->flags & TCP_HTTP_TRACK_FLG_COMP) {
13317 				log.u_bbr.flex8 |= 4;
13318 				log.u_bbr.epoch = http_req->end_seq;
13319 			}
13320 		}
13321 #endif
13322 		memset(tcp_hdr_buf, 0, sizeof(tcp_hdr_buf));
13323 		th = (struct tcphdr *)tcp_hdr_buf;
13324 		th->th_seq = ae->seq;
13325 		th->th_ack = ae->ack;
13326 		th->th_win = ae->win;
13327 		/* Now fill in the ports */
13328 		th->th_sport = tp->t_inpcb->inp_fport;
13329 		th->th_dport = tp->t_inpcb->inp_lport;
13330 		th->th_flags = ae->flags & 0xff;
13331 		/* Now do we have a timestamp option? */
13332 		if (ae->flags & HAS_TSTMP) {
13333 			u_char *cp;
13334 			uint32_t val;
13335 
13336 			th->th_off = ((sizeof(struct tcphdr) + TCPOLEN_TSTAMP_APPA) >> 2);
13337 			cp = (u_char *)(th + 1);
13338 			*cp = TCPOPT_NOP;
13339 			cp++;
13340 			*cp = TCPOPT_NOP;
13341 			cp++;
13342 			*cp = TCPOPT_TIMESTAMP;
13343 			cp++;
13344 			*cp = TCPOLEN_TIMESTAMP;
13345 			cp++;
13346 			val = htonl(ae->ts_value);
13347 			bcopy((char *)&val,
13348 			      (char *)cp, sizeof(uint32_t));
13349 			val = htonl(ae->ts_echo);
13350 			bcopy((char *)&val,
13351 			      (char *)(cp + 4), sizeof(uint32_t));
13352 		} else
13353 			th->th_off = (sizeof(struct tcphdr) >> 2);
13354 
13355 		/*
13356 		 * For sane logging we need to play a little trick.
13357 		 * If the ack were fully processed we would have moved
13358 		 * snd_una to high_seq, but since compressed acks are
13359 		 * processed in two phases, at this point (logging) snd_una
13360 		 * won't be advanced. So we would see multiple acks showing
13361 		 * the advancement. We can prevent that by "pretending" that
13362 		 * snd_una was advanced and then un-advancing it so that the
13363 		 * logging code has the right value for tlb_snd_una.
13364 		 */
13365 		if (tp->snd_una != high_seq) {
13366 			orig_snd_una = tp->snd_una;
13367 			tp->snd_una = high_seq;
13368 			xx = 1;
13369 		} else
13370 			xx = 0;
13371 		TCP_LOG_EVENTP(tp, th,
13372 			       &tp->t_inpcb->inp_socket->so_rcv,
13373 			       &tp->t_inpcb->inp_socket->so_snd, TCP_LOG_IN, 0,
13374 			       0, &log, true, &ltv);
13375 		if (xx) {
13376 			tp->snd_una = orig_snd_una;
13377 		}
13378 	}
13379 
13380 }
13381 
13382 static int
13383 rack_do_compressed_ack_processing(struct tcpcb *tp, struct socket *so, struct mbuf *m, int nxt_pkt, struct timeval *tv)
13384 {
13385 	/*
13386 	 * Handle a "special" compressed ack mbuf. Each incoming
13387 	 * ack has only four possible dispositions:
13388 	 *
13389 	 * A) It moves the cum-ack forward
13390 	 * B) It is behind the cum-ack.
13391 	 * C) It is a window-update ack.
13392 	 * D) It is a dup-ack.
13393 	 *
13394 	 * Note that we can have between 1 -> TCP_COMP_ACK_ENTRIES
13395 	 * in the incoming mbuf. We also need to still pay attention
13396 	 * to nxt_pkt since there may be another packet after this
13397 	 * one.
13398 	 */
13399 #ifdef TCP_ACCOUNTING
13400 	uint64_t ts_val;
13401 	uint64_t rdstc;
13402 #endif
13403 	int segsiz;
13404 	struct timespec ts;
13405 	struct tcp_rack *rack;
13406 	struct tcp_ackent *ae;
13407 	uint32_t tiwin, ms_cts, cts, acked, acked_amount, high_seq, win_seq, the_win, win_upd_ack;
13408 	int cnt, i, did_out, ourfinisacked = 0;
13409 	struct tcpopt to_holder, *to = NULL;
13410 	int win_up_req = 0;
13411 	int nsegs = 0;
13412 	int under_pacing = 1;
13413 	int recovery = 0;
13414 	int idx;
13415 #ifdef TCP_ACCOUNTING
13416 	sched_pin();
13417 #endif
13418 	rack = (struct tcp_rack *)tp->t_fb_ptr;
13419 	if (rack->gp_ready &&
13420 	    (rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT))
13421 		under_pacing = 0;
13422 	else
13423 		under_pacing = 1;
13424 
13425 	if (rack->r_state != tp->t_state)
13426 		rack_set_state(tp, rack);
13427 	if ((tp->t_state >= TCPS_FIN_WAIT_1) &&
13428 	    (tp->t_flags & TF_GPUTINPROG)) {
13429 		/*
13430 		 * We have a goodput in progress
13431 		 * and we have entered a late state.
13432 		 * Do we have enough data in the sb
13433 		 * to handle the GPUT request?
13434 		 */
13435 		uint32_t bytes;
13436 
13437 		bytes = tp->gput_ack - tp->gput_seq;
13438 		if (SEQ_GT(tp->gput_seq, tp->snd_una))
13439 			bytes += tp->gput_seq - tp->snd_una;
13440 		if (bytes > sbavail(&tp->t_inpcb->inp_socket->so_snd)) {
13441 			/*
13442 			 * There are not enough bytes in the socket
13443 			 * buffer that have been sent to cover this
13444 			 * measurement. Cancel it.
13445 			 */
13446 			rack_log_pacing_delay_calc(rack, (tp->gput_ack - tp->gput_seq) /*flex2*/,
13447 						   rack->r_ctl.rc_gp_srtt /*flex1*/,
13448 						   tp->gput_seq,
13449 						   0, 0, 18, __LINE__, NULL, 0);
13450 			tp->t_flags &= ~TF_GPUTINPROG;
13451 		}
13452 	}
13453 	to = &to_holder;
13454 	to->to_flags = 0;
13455 	KASSERT((m->m_len >= sizeof(struct tcp_ackent)),
13456 		("tp:%p m_cmpack:%p with invalid len:%u", tp, m, m->m_len));
13457 	cnt = m->m_len / sizeof(struct tcp_ackent);
13458 	idx = cnt / 5;
13459 	if (idx >= MAX_NUM_OF_CNTS)
13460 		idx = MAX_NUM_OF_CNTS - 1;
13461 	counter_u64_add(rack_proc_comp_ack[idx], 1);
13462 	counter_u64_add(rack_multi_single_eq, cnt);
13463 	high_seq = tp->snd_una;
13464 	the_win = tp->snd_wnd;
13465 	win_seq = tp->snd_wl1;
13466 	win_upd_ack = tp->snd_wl2;
13467 	cts = tcp_tv_to_usectick(tv);
13468 	ms_cts = tcp_tv_to_mssectick(tv);
13469 	segsiz = ctf_fixed_maxseg(tp);
13470 	if ((rack->rc_gp_dyn_mul) &&
13471 	    (rack->use_fixed_rate == 0) &&
13472 	    (rack->rc_always_pace)) {
13473 		/* Check in on probertt */
13474 		rack_check_probe_rtt(rack, cts);
13475 	}
13476 	for (i = 0; i < cnt; i++) {
13477 #ifdef TCP_ACCOUNTING
13478 		ts_val = get_cyclecount();
13479 #endif
13480 		rack_clear_rate_sample(rack);
13481 		ae = ((mtod(m, struct tcp_ackent *)) + i);
13482 		/* Setup the window */
13483 		tiwin = ae->win << tp->snd_scale;
13484 		/* figure out the type of ack */
13485 		if (SEQ_LT(ae->ack, high_seq)) {
13486 			/* Case B*/
13487 			ae->ack_val_set = ACK_BEHIND;
13488 		} else if (SEQ_GT(ae->ack, high_seq)) {
13489 			/* Case A */
13490 			ae->ack_val_set = ACK_CUMACK;
13491 		} else if (tiwin == the_win) {
13492 			/* Case D */
13493 			ae->ack_val_set = ACK_DUPACK;
13494 		} else {
13495 			/* Case C */
13496 			ae->ack_val_set = ACK_RWND;
13497 		}
13498 		rack_log_input_packet(tp, rack, ae, ae->ack_val_set, high_seq);
13499 		/* Validate timestamp */
13500 		if (ae->flags & HAS_TSTMP) {
13501 			/* Setup for a timestamp */
13502 			to->to_flags = TOF_TS;
13503 			ae->ts_echo -= tp->ts_offset;
13504 			to->to_tsecr = ae->ts_echo;
13505 			to->to_tsval = ae->ts_value;
13506 			/*
13507 			 * If echoed timestamp is later than the current time, fall back to
13508 			 * non RFC1323 RTT calculation.  Normalize timestamp if syncookies
13509 			 * were used when this connection was established.
13510 			 */
13511 			if (TSTMP_GT(ae->ts_echo, ms_cts))
13512 				to->to_tsecr = 0;
13513 			if (tp->ts_recent &&
13514 			    TSTMP_LT(ae->ts_value, tp->ts_recent)) {
13515 				if (ctf_ts_check_ac(tp, (ae->flags & 0xff))) {
13516 #ifdef TCP_ACCOUNTING
13517 					rdstc = get_cyclecount();
13518 					if (rdstc > ts_val) {
13519 						counter_u64_add(tcp_proc_time[ae->ack_val_set] ,
13520 								(rdstc - ts_val));
13521 						if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
13522 							tp->tcp_proc_time[ae->ack_val_set] += (rdstc - ts_val);
13523 						}
13524 					}
13525 #endif
13526 					continue;
13527 				}
13528 			}
13529 			if (SEQ_LEQ(ae->seq, tp->last_ack_sent) &&
13530 			    SEQ_LEQ(tp->last_ack_sent, ae->seq)) {
13531 				tp->ts_recent_age = tcp_ts_getticks();
13532 				tp->ts_recent = ae->ts_value;
13533 			}
13534 		} else {
13535 			/* Setup for a no options */
13536 			to->to_flags = 0;
13537 		}
13538 		/* Update the rcv time and perform idle reduction possibly */
13539 		if  (tp->t_idle_reduce &&
13540 		     (tp->snd_max == tp->snd_una) &&
13541 		     ((ticks - tp->t_rcvtime) >= tp->t_rxtcur)) {
13542 			counter_u64_add(rack_input_idle_reduces, 1);
13543 			rack_cc_after_idle(rack, tp);
13544 		}
13545 		tp->t_rcvtime = ticks;
13546 		/* Now what about ECN? */
13547 		if (tp->t_flags2 & TF2_ECN_PERMIT) {
13548 			if (ae->flags & TH_CWR) {
13549 				tp->t_flags2 &= ~TF2_ECN_SND_ECE;
13550 				tp->t_flags |= TF_ACKNOW;
13551 			}
13552 			switch (ae->codepoint & IPTOS_ECN_MASK) {
13553 			case IPTOS_ECN_CE:
13554 				tp->t_flags2 |= TF2_ECN_SND_ECE;
13555 				KMOD_TCPSTAT_INC(tcps_ecn_ce);
13556 				break;
13557 			case IPTOS_ECN_ECT0:
13558 				KMOD_TCPSTAT_INC(tcps_ecn_ect0);
13559 				break;
13560 			case IPTOS_ECN_ECT1:
13561 				KMOD_TCPSTAT_INC(tcps_ecn_ect1);
13562 				break;
13563 			}
13564 
13565 			/* Process a packet differently from RFC3168. */
13566 			cc_ecnpkt_handler_flags(tp, ae->flags, ae->codepoint);
13567 			/* Congestion experienced. */
13568 			if (ae->flags & TH_ECE) {
13569 				rack_cong_signal(tp,  CC_ECN, ae->ack);
13570 			}
13571 		}
13572 #ifdef TCP_ACCOUNTING
13573 		/* Count for the specific type of ack in */
13574 		counter_u64_add(tcp_cnt_counters[ae->ack_val_set], 1);
13575 		if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
13576 			tp->tcp_cnt_counters[ae->ack_val_set]++;
13577 		}
13578 #endif
13579 		/*
13580 		 * Note how we could move up these in the determination
13581 		 * above, but we don't so that way the timestamp checks (and ECN)
13582 		 * is done first before we do any processing on the ACK.
13583 		 * The non-compressed path through the code has this
13584 		 * weakness (noted by @jtl) that it actually does some
13585 		 * processing before verifying the timestamp information.
13586 		 * We don't take that path here which is why we set
13587 		 * the ack_val_set first, do the timestamp and ecn
13588 		 * processing, and then look at what we have setup.
13589 		 */
13590 		if (ae->ack_val_set == ACK_BEHIND) {
13591 			/*
13592 			 * Case B flag reordering, if window is not closed
13593 			 * or it could be a keep-alive or persists
13594 			 */
13595 			if (SEQ_LT(ae->ack, tp->snd_una) && (sbspace(&so->so_rcv) > segsiz)) {
13596 				counter_u64_add(rack_reorder_seen, 1);
13597 				rack->r_ctl.rc_reorder_ts = tcp_tv_to_usectick(&rack->r_ctl.act_rcv_time);
13598 			}
13599 		} else if (ae->ack_val_set == ACK_DUPACK) {
13600 			/* Case D */
13601 			rack_strike_dupack(rack);
13602 		} else if (ae->ack_val_set == ACK_RWND) {
13603 			/* Case C */
13604 			win_up_req = 1;
13605 			win_upd_ack = ae->ack;
13606 			win_seq = ae->seq;
13607 			the_win = tiwin;
13608 			rack_do_win_updates(tp, rack, the_win, win_seq, win_upd_ack, cts, high_seq);
13609 		} else {
13610 			/* Case A */
13611 			if (SEQ_GT(ae->ack, tp->snd_max)) {
13612 				/*
13613 				 * We just send an ack since the incoming
13614 				 * ack is beyond the largest seq we sent.
13615 				 */
13616 				if ((tp->t_flags & TF_ACKNOW) == 0) {
13617 					ctf_ack_war_checks(tp, &rack->r_ctl.challenge_ack_ts, &rack->r_ctl.challenge_ack_cnt);
13618 					if (tp->t_flags && TF_ACKNOW)
13619 						rack->r_wanted_output = 1;
13620 				}
13621 			} else {
13622 				nsegs++;
13623 				/* If the window changed setup to update */
13624 				if (tiwin != tp->snd_wnd) {
13625 					win_upd_ack = ae->ack;
13626 					win_seq = ae->seq;
13627 					the_win = tiwin;
13628 					rack_do_win_updates(tp, rack, the_win, win_seq, win_upd_ack, cts, high_seq);
13629 				}
13630 #ifdef TCP_ACCOUNTING
13631 				/* Account for the acks */
13632 				if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
13633 					tp->tcp_cnt_counters[CNT_OF_ACKS_IN] += (((ae->ack - high_seq) + segsiz - 1) / segsiz);
13634 				}
13635 				counter_u64_add(tcp_cnt_counters[CNT_OF_ACKS_IN],
13636 						(((ae->ack - high_seq) + segsiz - 1) / segsiz));
13637 #endif
13638 				high_seq = ae->ack;
13639 				if (SEQ_GEQ(high_seq, rack->r_ctl.roundends)) {
13640 					rack->r_ctl.current_round++;
13641 					rack->r_ctl.roundends = tp->snd_max;
13642 					if (CC_ALGO(tp)->newround != NULL) {
13643 						CC_ALGO(tp)->newround(tp->ccv, rack->r_ctl.current_round);
13644 					}
13645 				}
13646 				/* Setup our act_rcv_time */
13647 				if ((ae->flags & TSTMP_LRO) || (ae->flags & TSTMP_HDWR)) {
13648 					ts.tv_sec = ae->timestamp / 1000000000;
13649 					ts.tv_nsec = ae->timestamp % 1000000000;
13650 					rack->r_ctl.act_rcv_time.tv_sec = ts.tv_sec;
13651 					rack->r_ctl.act_rcv_time.tv_usec = ts.tv_nsec/1000;
13652 				} else {
13653 					rack->r_ctl.act_rcv_time = *tv;
13654 				}
13655 				rack_process_to_cumack(tp, rack, ae->ack, cts, to);
13656 				if (rack->rc_dsack_round_seen) {
13657 					/* Is the dsack round over? */
13658 					if (SEQ_GEQ(ae->ack, rack->r_ctl.dsack_round_end)) {
13659 						/* Yes it is */
13660 						rack->rc_dsack_round_seen = 0;
13661 						rack_log_dsack_event(rack, 3, __LINE__, 0, 0);
13662 					}
13663 				}
13664 			}
13665 		}
13666 		/* And lets be sure to commit the rtt measurements for this ack */
13667 		tcp_rack_xmit_timer_commit(rack, tp);
13668 #ifdef TCP_ACCOUNTING
13669 		rdstc = get_cyclecount();
13670 		if (rdstc > ts_val) {
13671 			counter_u64_add(tcp_proc_time[ae->ack_val_set] , (rdstc - ts_val));
13672 			if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
13673 				tp->tcp_proc_time[ae->ack_val_set] += (rdstc - ts_val);
13674 				if (ae->ack_val_set == ACK_CUMACK)
13675 					tp->tcp_proc_time[CYC_HANDLE_MAP] += (rdstc - ts_val);
13676 			}
13677 		}
13678 #endif
13679 	}
13680 #ifdef TCP_ACCOUNTING
13681 	ts_val = get_cyclecount();
13682 #endif
13683 	acked_amount = acked = (high_seq - tp->snd_una);
13684 	if (acked) {
13685 		if (rack->sack_attack_disable == 0)
13686 			rack_do_decay(rack);
13687 		if (acked >= segsiz) {
13688 			/*
13689 			 * You only get credit for
13690 			 * MSS and greater (and you get extra
13691 			 * credit for larger cum-ack moves).
13692 			 */
13693 			int ac;
13694 
13695 			ac = acked / segsiz;
13696 			rack->r_ctl.ack_count += ac;
13697 			counter_u64_add(rack_ack_total, ac);
13698 		}
13699 		if (rack->r_ctl.ack_count > 0xfff00000) {
13700 			/*
13701 			 * reduce the number to keep us under
13702 			 * a uint32_t.
13703 			 */
13704 			rack->r_ctl.ack_count /= 2;
13705 			rack->r_ctl.sack_count /= 2;
13706 		}
13707 		if (tp->t_flags & TF_NEEDSYN) {
13708 			/*
13709 			 * T/TCP: Connection was half-synchronized, and our SYN has
13710 			 * been ACK'd (so connection is now fully synchronized).  Go
13711 			 * to non-starred state, increment snd_una for ACK of SYN,
13712 			 * and check if we can do window scaling.
13713 			 */
13714 			tp->t_flags &= ~TF_NEEDSYN;
13715 			tp->snd_una++;
13716 			acked_amount = acked = (high_seq - tp->snd_una);
13717 		}
13718 		if (acked > sbavail(&so->so_snd))
13719 			acked_amount = sbavail(&so->so_snd);
13720 #ifdef NETFLIX_EXP_DETECTION
13721 		/*
13722 		 * We only care on a cum-ack move if we are in a sack-disabled
13723 		 * state. We have already added in to the ack_count, and we never
13724 		 * would disable on a cum-ack move, so we only care to do the
13725 		 * detection if it may "undo" it, i.e. we were in disabled already.
13726 		 */
13727 		if (rack->sack_attack_disable)
13728 			rack_do_detection(tp, rack, acked_amount, segsiz);
13729 #endif
13730 		if (IN_FASTRECOVERY(tp->t_flags) &&
13731 		    (rack->rack_no_prr == 0))
13732 			rack_update_prr(tp, rack, acked_amount, high_seq);
13733 		if (IN_RECOVERY(tp->t_flags)) {
13734 			if (SEQ_LT(high_seq, tp->snd_recover) &&
13735 			    (SEQ_LT(high_seq, tp->snd_max))) {
13736 				tcp_rack_partialack(tp);
13737 			} else {
13738 				rack_post_recovery(tp, high_seq);
13739 				recovery = 1;
13740 			}
13741 		}
13742 		/* Handle the rack-log-ack part (sendmap) */
13743 		if ((sbused(&so->so_snd) == 0) &&
13744 		    (acked > acked_amount) &&
13745 		    (tp->t_state >= TCPS_FIN_WAIT_1) &&
13746 		    (tp->t_flags & TF_SENTFIN)) {
13747 			/*
13748 			 * We must be sure our fin
13749 			 * was sent and acked (we can be
13750 			 * in FIN_WAIT_1 without having
13751 			 * sent the fin).
13752 			 */
13753 			ourfinisacked = 1;
13754 			/*
13755 			 * Lets make sure snd_una is updated
13756 			 * since most likely acked_amount = 0 (it
13757 			 * should be).
13758 			 */
13759 			tp->snd_una = high_seq;
13760 		}
13761 		/* Did we make a RTO error? */
13762 		if ((tp->t_flags & TF_PREVVALID) &&
13763 		    ((tp->t_flags & TF_RCVD_TSTMP) == 0)) {
13764 			tp->t_flags &= ~TF_PREVVALID;
13765 			if (tp->t_rxtshift == 1 &&
13766 			    (int)(ticks - tp->t_badrxtwin) < 0)
13767 				rack_cong_signal(tp, CC_RTO_ERR, high_seq);
13768 		}
13769 		/* Handle the data in the socket buffer */
13770 		KMOD_TCPSTAT_ADD(tcps_rcvackpack, 1);
13771 		KMOD_TCPSTAT_ADD(tcps_rcvackbyte, acked);
13772 		if (acked_amount > 0) {
13773 			struct mbuf *mfree;
13774 
13775 			rack_ack_received(tp, rack, high_seq, nsegs, CC_ACK, recovery);
13776 			SOCKBUF_LOCK(&so->so_snd);
13777 			mfree = sbcut_locked(&so->so_snd, acked_amount);
13778 			tp->snd_una = high_seq;
13779 			/* Note we want to hold the sb lock through the sendmap adjust */
13780 			rack_adjust_sendmap(rack, &so->so_snd, tp->snd_una);
13781 			/* Wake up the socket if we have room to write more */
13782 			rack_log_wakeup(tp,rack, &so->so_snd, acked, 2);
13783 			sowwakeup_locked(so);
13784 			m_freem(mfree);
13785 		}
13786 		/* update progress */
13787 		tp->t_acktime = ticks;
13788 		rack_log_progress_event(rack, tp, tp->t_acktime,
13789 					PROGRESS_UPDATE, __LINE__);
13790 		/* Clear out shifts and such */
13791 		tp->t_rxtshift = 0;
13792 		RACK_TCPT_RANGESET(tp->t_rxtcur, RACK_REXMTVAL(tp),
13793 				   rack_rto_min, rack_rto_max, rack->r_ctl.timer_slop);
13794 		rack->rc_tlp_in_progress = 0;
13795 		rack->r_ctl.rc_tlp_cnt_out = 0;
13796 		/* Send recover and snd_nxt must be dragged along */
13797 		if (SEQ_GT(tp->snd_una, tp->snd_recover))
13798 			tp->snd_recover = tp->snd_una;
13799 		if (SEQ_LT(tp->snd_nxt, tp->snd_una))
13800 			tp->snd_nxt = tp->snd_una;
13801 		/*
13802 		 * If the RXT timer is running we want to
13803 		 * stop it, so we can restart a TLP (or new RXT).
13804 		 */
13805 		if (rack->r_ctl.rc_hpts_flags & PACE_TMR_RXT)
13806 			rack_timer_cancel(tp, rack, rack->r_ctl.rc_rcvtime, __LINE__);
13807 #ifdef NETFLIX_HTTP_LOGGING
13808 		tcp_http_check_for_comp(rack->rc_tp, high_seq);
13809 #endif
13810 		tp->snd_wl2 = high_seq;
13811 		tp->t_dupacks = 0;
13812 		if (under_pacing &&
13813 		    (rack->use_fixed_rate == 0) &&
13814 		    (rack->in_probe_rtt == 0) &&
13815 		    rack->rc_gp_dyn_mul &&
13816 		    rack->rc_always_pace) {
13817 			/* Check if we are dragging bottom */
13818 			rack_check_bottom_drag(tp, rack, so, acked);
13819 		}
13820 		if (tp->snd_una == tp->snd_max) {
13821 			tp->t_flags &= ~TF_PREVVALID;
13822 			rack->r_ctl.retran_during_recovery = 0;
13823 			rack->r_ctl.dsack_byte_cnt = 0;
13824 			rack->r_ctl.rc_went_idle_time = tcp_get_usecs(NULL);
13825 			if (rack->r_ctl.rc_went_idle_time == 0)
13826 				rack->r_ctl.rc_went_idle_time = 1;
13827 			rack_log_progress_event(rack, tp, 0, PROGRESS_CLEAR, __LINE__);
13828 			if (sbavail(&tp->t_inpcb->inp_socket->so_snd) == 0)
13829 				tp->t_acktime = 0;
13830 			/* Set so we might enter persists... */
13831 			rack->r_wanted_output = 1;
13832 			rack_timer_cancel(tp, rack, rack->r_ctl.rc_rcvtime, __LINE__);
13833 			sack_filter_clear(&rack->r_ctl.rack_sf, tp->snd_una);
13834 			if ((tp->t_state >= TCPS_FIN_WAIT_1) &&
13835 			    (sbavail(&so->so_snd) == 0) &&
13836 			    (tp->t_flags2 & TF2_DROP_AF_DATA)) {
13837 				/*
13838 				 * The socket was gone and the
13839 				 * peer sent data (not now in the past), time to
13840 				 * reset him.
13841 				 */
13842 				rack_timer_cancel(tp, rack, rack->r_ctl.rc_rcvtime, __LINE__);
13843 				/* tcp_close will kill the inp pre-log the Reset */
13844 				tcp_log_end_status(tp, TCP_EI_STATUS_SERVER_RST);
13845 #ifdef TCP_ACCOUNTING
13846 				rdstc = get_cyclecount();
13847 				if (rdstc > ts_val) {
13848 					counter_u64_add(tcp_proc_time[ACK_CUMACK] , (rdstc - ts_val));
13849 					if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
13850 						tp->tcp_proc_time[ACK_CUMACK] += (rdstc - ts_val);
13851 						tp->tcp_proc_time[CYC_HANDLE_ACK] += (rdstc - ts_val);
13852 					}
13853 				}
13854 #endif
13855 				m_freem(m);
13856 				tp = tcp_close(tp);
13857 				if (tp == NULL) {
13858 #ifdef TCP_ACCOUNTING
13859 					sched_unpin();
13860 #endif
13861 					return (1);
13862 				}
13863 				/*
13864 				 * We would normally do drop-with-reset which would
13865 				 * send back a reset. We can't since we don't have
13866 				 * all the needed bits. Instead lets arrange for
13867 				 * a call to tcp_output(). That way since we
13868 				 * are in the closed state we will generate a reset.
13869 				 *
13870 				 * Note if tcp_accounting is on we don't unpin since
13871 				 * we do that after the goto label.
13872 				 */
13873 				goto send_out_a_rst;
13874 			}
13875 			if ((sbused(&so->so_snd) == 0) &&
13876 			    (tp->t_state >= TCPS_FIN_WAIT_1) &&
13877 			    (tp->t_flags & TF_SENTFIN)) {
13878 				/*
13879 				 * If we can't receive any more data, then closing user can
13880 				 * proceed. Starting the timer is contrary to the
13881 				 * specification, but if we don't get a FIN we'll hang
13882 				 * forever.
13883 				 *
13884 				 */
13885 				if (so->so_rcv.sb_state & SBS_CANTRCVMORE) {
13886 					soisdisconnected(so);
13887 					tcp_timer_activate(tp, TT_2MSL,
13888 							   (tcp_fast_finwait2_recycle ?
13889 							    tcp_finwait2_timeout :
13890 							    TP_MAXIDLE(tp)));
13891 				}
13892 				if (ourfinisacked == 0) {
13893 					/*
13894 					 * We don't change to fin-wait-2 if we have our fin acked
13895 					 * which means we are probably in TCPS_CLOSING.
13896 					 */
13897 					tcp_state_change(tp, TCPS_FIN_WAIT_2);
13898 				}
13899 			}
13900 		}
13901 		/* Wake up the socket if we have room to write more */
13902 		if (sbavail(&so->so_snd)) {
13903 			rack->r_wanted_output = 1;
13904 			if (ctf_progress_timeout_check(tp, true)) {
13905 				rack_log_progress_event((struct tcp_rack *)tp->t_fb_ptr,
13906 							tp, tick, PROGRESS_DROP, __LINE__);
13907 				tcp_set_inp_to_drop(tp->t_inpcb, ETIMEDOUT);
13908 				/*
13909 				 * We cheat here and don't send a RST, we should send one
13910 				 * when the pacer drops the connection.
13911 				 */
13912 #ifdef TCP_ACCOUNTING
13913 				rdstc = get_cyclecount();
13914 				if (rdstc > ts_val) {
13915 					counter_u64_add(tcp_proc_time[ACK_CUMACK] , (rdstc - ts_val));
13916 					if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
13917 						tp->tcp_proc_time[ACK_CUMACK] += (rdstc - ts_val);
13918 						tp->tcp_proc_time[CYC_HANDLE_ACK] += (rdstc - ts_val);
13919 					}
13920 				}
13921 				sched_unpin();
13922 #endif
13923 				INP_WUNLOCK(rack->rc_inp);
13924 				m_freem(m);
13925 				return (1);
13926 			}
13927 		}
13928 		if (ourfinisacked) {
13929 			switch(tp->t_state) {
13930 			case TCPS_CLOSING:
13931 #ifdef TCP_ACCOUNTING
13932 				rdstc = get_cyclecount();
13933 				if (rdstc > ts_val) {
13934 					counter_u64_add(tcp_proc_time[ACK_CUMACK] ,
13935 							(rdstc - ts_val));
13936 					if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
13937 						tp->tcp_proc_time[ACK_CUMACK] += (rdstc - ts_val);
13938 						tp->tcp_proc_time[CYC_HANDLE_ACK] += (rdstc - ts_val);
13939 					}
13940 				}
13941 				sched_unpin();
13942 #endif
13943 				tcp_twstart(tp);
13944 				m_freem(m);
13945 				return (1);
13946 				break;
13947 			case TCPS_LAST_ACK:
13948 #ifdef TCP_ACCOUNTING
13949 				rdstc = get_cyclecount();
13950 				if (rdstc > ts_val) {
13951 					counter_u64_add(tcp_proc_time[ACK_CUMACK] ,
13952 							(rdstc - ts_val));
13953 					if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
13954 						tp->tcp_proc_time[ACK_CUMACK] += (rdstc - ts_val);
13955 						tp->tcp_proc_time[CYC_HANDLE_ACK] += (rdstc - ts_val);
13956 					}
13957 				}
13958 				sched_unpin();
13959 #endif
13960 				tp = tcp_close(tp);
13961 				ctf_do_drop(m, tp);
13962 				return (1);
13963 				break;
13964 			case TCPS_FIN_WAIT_1:
13965 #ifdef TCP_ACCOUNTING
13966 				rdstc = get_cyclecount();
13967 				if (rdstc > ts_val) {
13968 					counter_u64_add(tcp_proc_time[ACK_CUMACK] ,
13969 							(rdstc - ts_val));
13970 					if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
13971 						tp->tcp_proc_time[ACK_CUMACK] += (rdstc - ts_val);
13972 						tp->tcp_proc_time[CYC_HANDLE_ACK] += (rdstc - ts_val);
13973 					}
13974 				}
13975 #endif
13976 				if (so->so_rcv.sb_state & SBS_CANTRCVMORE) {
13977 					soisdisconnected(so);
13978 					tcp_timer_activate(tp, TT_2MSL,
13979 							   (tcp_fast_finwait2_recycle ?
13980 							    tcp_finwait2_timeout :
13981 							    TP_MAXIDLE(tp)));
13982 				}
13983 				tcp_state_change(tp, TCPS_FIN_WAIT_2);
13984 				break;
13985 			default:
13986 				break;
13987 			}
13988 		}
13989 		if (rack->r_fast_output) {
13990 			/*
13991 			 * We re doing fast output.. can we expand that?
13992 			 */
13993 			rack_gain_for_fastoutput(rack, tp, so, acked_amount);
13994 		}
13995 #ifdef TCP_ACCOUNTING
13996 		rdstc = get_cyclecount();
13997 		if (rdstc > ts_val) {
13998 			counter_u64_add(tcp_proc_time[ACK_CUMACK] , (rdstc - ts_val));
13999 			if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
14000 				tp->tcp_proc_time[ACK_CUMACK] += (rdstc - ts_val);
14001 				tp->tcp_proc_time[CYC_HANDLE_ACK] += (rdstc - ts_val);
14002 			}
14003 		}
14004 
14005 	} else if (win_up_req) {
14006 		rdstc = get_cyclecount();
14007 		if (rdstc > ts_val) {
14008 			counter_u64_add(tcp_proc_time[ACK_RWND] , (rdstc - ts_val));
14009 			if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
14010 				tp->tcp_proc_time[ACK_RWND] += (rdstc - ts_val);
14011 			}
14012 		}
14013 #endif
14014 	}
14015 	/* Now is there a next packet, if so we are done */
14016 	m_freem(m);
14017 	did_out = 0;
14018 	if (nxt_pkt) {
14019 #ifdef TCP_ACCOUNTING
14020 		sched_unpin();
14021 #endif
14022 		rack_log_doseg_done(rack, cts, nxt_pkt, did_out, 5, nsegs);
14023 		return (0);
14024 	}
14025 	rack_handle_might_revert(tp, rack);
14026 	ctf_calc_rwin(so, tp);
14027 	if ((rack->r_wanted_output != 0) || (rack->r_fast_output != 0)) {
14028 	send_out_a_rst:
14029 		(void)tp->t_fb->tfb_tcp_output(tp);
14030 		did_out = 1;
14031 	}
14032 	rack_free_trim(rack);
14033 #ifdef TCP_ACCOUNTING
14034 	sched_unpin();
14035 #endif
14036 	rack_timer_audit(tp, rack, &so->so_snd);
14037 	rack_log_doseg_done(rack, cts, nxt_pkt, did_out, 6, nsegs);
14038 	return (0);
14039 }
14040 
14041 
14042 static int
14043 rack_do_segment_nounlock(struct mbuf *m, struct tcphdr *th, struct socket *so,
14044     struct tcpcb *tp, int32_t drop_hdrlen, int32_t tlen, uint8_t iptos,
14045     int32_t nxt_pkt, struct timeval *tv)
14046 {
14047 #ifdef TCP_ACCOUNTING
14048 	uint64_t ts_val;
14049 #endif
14050 	int32_t thflags, retval, did_out = 0;
14051 	int32_t way_out = 0;
14052 	/*
14053 	 * cts - is the current time from tv (caller gets ts) in microseconds.
14054 	 * ms_cts - is the current time from tv in milliseconds.
14055 	 * us_cts - is the time that LRO or hardware actually got the packet in microseconds.
14056 	 */
14057 	uint32_t cts, us_cts, ms_cts;
14058 	uint32_t tiwin;
14059 	struct timespec ts;
14060 	struct tcpopt to;
14061 	struct tcp_rack *rack;
14062 	struct rack_sendmap *rsm;
14063 	int32_t prev_state = 0;
14064 #ifdef TCP_ACCOUNTING
14065 	int ack_val_set = 0xf;
14066 #endif
14067 	int nsegs;
14068 	/*
14069 	 * tv passed from common code is from either M_TSTMP_LRO or
14070 	 * tcp_get_usecs() if no LRO m_pkthdr timestamp is present.
14071 	 */
14072 	rack = (struct tcp_rack *)tp->t_fb_ptr;
14073 	if (m->m_flags & M_ACKCMP) {
14074 		return (rack_do_compressed_ack_processing(tp, so, m, nxt_pkt, tv));
14075 	}
14076 	if (m->m_flags & M_ACKCMP) {
14077 		panic("Impossible reach m has ackcmp? m:%p tp:%p", m, tp);
14078 	}
14079 	cts = tcp_tv_to_usectick(tv);
14080 	ms_cts =  tcp_tv_to_mssectick(tv);
14081 	nsegs = m->m_pkthdr.lro_nsegs;
14082 	counter_u64_add(rack_proc_non_comp_ack, 1);
14083 	thflags = th->th_flags;
14084 #ifdef TCP_ACCOUNTING
14085 	sched_pin();
14086 	if (thflags & TH_ACK)
14087 		ts_val = get_cyclecount();
14088 #endif
14089 	if ((m->m_flags & M_TSTMP) ||
14090 	    (m->m_flags & M_TSTMP_LRO)) {
14091 		mbuf_tstmp2timespec(m, &ts);
14092 		rack->r_ctl.act_rcv_time.tv_sec = ts.tv_sec;
14093 		rack->r_ctl.act_rcv_time.tv_usec = ts.tv_nsec/1000;
14094 	} else
14095 		rack->r_ctl.act_rcv_time = *tv;
14096 	kern_prefetch(rack, &prev_state);
14097 	prev_state = 0;
14098 	/*
14099 	 * Unscale the window into a 32-bit value. For the SYN_SENT state
14100 	 * the scale is zero.
14101 	 */
14102 	tiwin = th->th_win << tp->snd_scale;
14103 #ifdef TCP_ACCOUNTING
14104 	if (thflags & TH_ACK) {
14105 		/*
14106 		 * We have a tradeoff here. We can either do what we are
14107 		 * doing i.e. pinning to this CPU and then doing the accounting
14108 		 * <or> we could do a critical enter, setup the rdtsc and cpu
14109 		 * as in below, and then validate we are on the same CPU on
14110 		 * exit. I have choosen to not do the critical enter since
14111 		 * that often will gain you a context switch, and instead lock
14112 		 * us (line above this if) to the same CPU with sched_pin(). This
14113 		 * means we may be context switched out for a higher priority
14114 		 * interupt but we won't be moved to another CPU.
14115 		 *
14116 		 * If this occurs (which it won't very often since we most likely
14117 		 * are running this code in interupt context and only a higher
14118 		 * priority will bump us ... clock?) we will falsely add in
14119 		 * to the time the interupt processing time plus the ack processing
14120 		 * time. This is ok since its a rare event.
14121 		 */
14122 		ack_val_set = tcp_do_ack_accounting(tp, th, &to, tiwin,
14123 						    ctf_fixed_maxseg(tp));
14124 	}
14125 #endif
14126 	/*
14127 	 * Parse options on any incoming segment.
14128 	 */
14129 	memset(&to, 0, sizeof(to));
14130 	tcp_dooptions(&to, (u_char *)(th + 1),
14131 	    (th->th_off << 2) - sizeof(struct tcphdr),
14132 	    (thflags & TH_SYN) ? TO_SYN : 0);
14133 	NET_EPOCH_ASSERT();
14134 	INP_WLOCK_ASSERT(tp->t_inpcb);
14135 	KASSERT(tp->t_state > TCPS_LISTEN, ("%s: TCPS_LISTEN",
14136 	    __func__));
14137 	KASSERT(tp->t_state != TCPS_TIME_WAIT, ("%s: TCPS_TIME_WAIT",
14138 	    __func__));
14139 	if ((tp->t_state >= TCPS_FIN_WAIT_1) &&
14140 	    (tp->t_flags & TF_GPUTINPROG)) {
14141 		/*
14142 		 * We have a goodput in progress
14143 		 * and we have entered a late state.
14144 		 * Do we have enough data in the sb
14145 		 * to handle the GPUT request?
14146 		 */
14147 		uint32_t bytes;
14148 
14149 		bytes = tp->gput_ack - tp->gput_seq;
14150 		if (SEQ_GT(tp->gput_seq, tp->snd_una))
14151 			bytes += tp->gput_seq - tp->snd_una;
14152 		if (bytes > sbavail(&tp->t_inpcb->inp_socket->so_snd)) {
14153 			/*
14154 			 * There are not enough bytes in the socket
14155 			 * buffer that have been sent to cover this
14156 			 * measurement. Cancel it.
14157 			 */
14158 			rack_log_pacing_delay_calc(rack, (tp->gput_ack - tp->gput_seq) /*flex2*/,
14159 						   rack->r_ctl.rc_gp_srtt /*flex1*/,
14160 						   tp->gput_seq,
14161 						   0, 0, 18, __LINE__, NULL, 0);
14162 			tp->t_flags &= ~TF_GPUTINPROG;
14163 		}
14164 	}
14165 	if (tp->t_logstate != TCP_LOG_STATE_OFF) {
14166 		union tcp_log_stackspecific log;
14167 		struct timeval ltv;
14168 #ifdef NETFLIX_HTTP_LOGGING
14169 		struct http_sendfile_track *http_req;
14170 
14171 		if (SEQ_GT(th->th_ack, tp->snd_una)) {
14172 			http_req = tcp_http_find_req_for_seq(tp, (th->th_ack-1));
14173 		} else {
14174 			http_req = tcp_http_find_req_for_seq(tp, th->th_ack);
14175 		}
14176 #endif
14177 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
14178 		log.u_bbr.inhpts = rack->rc_inp->inp_in_hpts;
14179 		log.u_bbr.ininput = rack->rc_inp->inp_in_input;
14180 		if (rack->rack_no_prr == 0)
14181 			log.u_bbr.flex1 = rack->r_ctl.rc_prr_sndcnt;
14182 		else
14183 			log.u_bbr.flex1 = 0;
14184 		log.u_bbr.use_lt_bw = rack->r_ent_rec_ns;
14185 		log.u_bbr.use_lt_bw <<= 1;
14186 		log.u_bbr.use_lt_bw |= rack->r_might_revert;
14187 		log.u_bbr.flex2 = rack->r_ctl.rc_num_maps_alloced;
14188 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
14189 		log.u_bbr.pkts_out = rack->rc_tp->t_maxseg;
14190 		log.u_bbr.flex3 = m->m_flags;
14191 		log.u_bbr.flex4 = rack->r_ctl.rc_hpts_flags;
14192 		log.u_bbr.lost = thflags;
14193 		log.u_bbr.pacing_gain = 0x1;
14194 #ifdef TCP_ACCOUNTING
14195 		log.u_bbr.cwnd_gain = ack_val_set;
14196 #endif
14197 		log.u_bbr.flex7 = 2;
14198 		if (m->m_flags & M_TSTMP) {
14199 			/* Record the hardware timestamp if present */
14200 			mbuf_tstmp2timespec(m, &ts);
14201 			ltv.tv_sec = ts.tv_sec;
14202 			ltv.tv_usec = ts.tv_nsec / 1000;
14203 			log.u_bbr.lt_epoch = tcp_tv_to_usectick(&ltv);
14204 		} else if (m->m_flags & M_TSTMP_LRO) {
14205 			/* Record the LRO the arrival timestamp */
14206 			mbuf_tstmp2timespec(m, &ts);
14207 			ltv.tv_sec = ts.tv_sec;
14208 			ltv.tv_usec = ts.tv_nsec / 1000;
14209 			log.u_bbr.flex5 = tcp_tv_to_usectick(&ltv);
14210 		}
14211 		log.u_bbr.timeStamp = tcp_get_usecs(&ltv);
14212 		/* Log the rcv time */
14213 		log.u_bbr.delRate = m->m_pkthdr.rcv_tstmp;
14214 #ifdef NETFLIX_HTTP_LOGGING
14215 		log.u_bbr.applimited = tp->t_http_closed;
14216 		log.u_bbr.applimited <<= 8;
14217 		log.u_bbr.applimited |= tp->t_http_open;
14218 		log.u_bbr.applimited <<= 8;
14219 		log.u_bbr.applimited |= tp->t_http_req;
14220 		if (http_req) {
14221 			/* Copy out any client req info */
14222 			/* seconds */
14223 			log.u_bbr.pkt_epoch = (http_req->localtime / HPTS_USEC_IN_SEC);
14224 			/* useconds */
14225 			log.u_bbr.delivered = (http_req->localtime % HPTS_USEC_IN_SEC);
14226 			log.u_bbr.rttProp = http_req->timestamp;
14227 			log.u_bbr.cur_del_rate = http_req->start;
14228 			if (http_req->flags & TCP_HTTP_TRACK_FLG_OPEN) {
14229 				log.u_bbr.flex8 |= 1;
14230 			} else {
14231 				log.u_bbr.flex8 |= 2;
14232 				log.u_bbr.bw_inuse = http_req->end;
14233 			}
14234 			log.u_bbr.flex6 = http_req->start_seq;
14235 			if (http_req->flags & TCP_HTTP_TRACK_FLG_COMP) {
14236 				log.u_bbr.flex8 |= 4;
14237 				log.u_bbr.epoch = http_req->end_seq;
14238 			}
14239 		}
14240 #endif
14241 		TCP_LOG_EVENTP(tp, th, &so->so_rcv, &so->so_snd, TCP_LOG_IN, 0,
14242 		    tlen, &log, true, &ltv);
14243 	}
14244 	if ((thflags & TH_SYN) && (thflags & TH_FIN) && V_drop_synfin) {
14245 		way_out = 4;
14246 		retval = 0;
14247 		m_freem(m);
14248 		goto done_with_input;
14249 	}
14250 	/*
14251 	 * If a segment with the ACK-bit set arrives in the SYN-SENT state
14252 	 * check SEQ.ACK first as described on page 66 of RFC 793, section 3.9.
14253 	 */
14254 	if ((tp->t_state == TCPS_SYN_SENT) && (thflags & TH_ACK) &&
14255 	    (SEQ_LEQ(th->th_ack, tp->iss) || SEQ_GT(th->th_ack, tp->snd_max))) {
14256 		tcp_log_end_status(tp, TCP_EI_STATUS_RST_IN_FRONT);
14257 		ctf_do_dropwithreset(m, tp, th, BANDLIM_RST_OPENPORT, tlen);
14258 #ifdef TCP_ACCOUNTING
14259 		sched_unpin();
14260 #endif
14261 		return (1);
14262 	}
14263 	/*
14264 	 * If timestamps were negotiated during SYN/ACK and a
14265 	 * segment without a timestamp is received, silently drop
14266 	 * the segment, unless it is a RST segment or missing timestamps are
14267 	 * tolerated.
14268 	 * See section 3.2 of RFC 7323.
14269 	 */
14270 	if ((tp->t_flags & TF_RCVD_TSTMP) && !(to.to_flags & TOF_TS) &&
14271 	    ((thflags & TH_RST) == 0) && (V_tcp_tolerate_missing_ts == 0)) {
14272 		way_out = 5;
14273 		retval = 0;
14274 		m_freem(m);
14275 		goto done_with_input;
14276 	}
14277 
14278 	/*
14279 	 * Segment received on connection. Reset idle time and keep-alive
14280 	 * timer. XXX: This should be done after segment validation to
14281 	 * ignore broken/spoofed segs.
14282 	 */
14283 	if  (tp->t_idle_reduce &&
14284 	     (tp->snd_max == tp->snd_una) &&
14285 	     ((ticks - tp->t_rcvtime) >= tp->t_rxtcur)) {
14286 		counter_u64_add(rack_input_idle_reduces, 1);
14287 		rack_cc_after_idle(rack, tp);
14288 	}
14289 	tp->t_rcvtime = ticks;
14290 #ifdef STATS
14291 	stats_voi_update_abs_ulong(tp->t_stats, VOI_TCP_FRWIN, tiwin);
14292 #endif
14293 	if (tiwin > rack->r_ctl.rc_high_rwnd)
14294 		rack->r_ctl.rc_high_rwnd = tiwin;
14295 	/*
14296 	 * TCP ECN processing. XXXJTL: If we ever use ECN, we need to move
14297 	 * this to occur after we've validated the segment.
14298 	 */
14299 	if (tp->t_flags2 & TF2_ECN_PERMIT) {
14300 		if (thflags & TH_CWR) {
14301 			tp->t_flags2 &= ~TF2_ECN_SND_ECE;
14302 			tp->t_flags |= TF_ACKNOW;
14303 		}
14304 		switch (iptos & IPTOS_ECN_MASK) {
14305 		case IPTOS_ECN_CE:
14306 			tp->t_flags2 |= TF2_ECN_SND_ECE;
14307 			KMOD_TCPSTAT_INC(tcps_ecn_ce);
14308 			break;
14309 		case IPTOS_ECN_ECT0:
14310 			KMOD_TCPSTAT_INC(tcps_ecn_ect0);
14311 			break;
14312 		case IPTOS_ECN_ECT1:
14313 			KMOD_TCPSTAT_INC(tcps_ecn_ect1);
14314 			break;
14315 		}
14316 
14317 		/* Process a packet differently from RFC3168. */
14318 		cc_ecnpkt_handler(tp, th, iptos);
14319 
14320 		/* Congestion experienced. */
14321 		if (thflags & TH_ECE) {
14322 			rack_cong_signal(tp, CC_ECN, th->th_ack);
14323 		}
14324 	}
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 = tp->t_inpcb;
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 			if (!(thflags & TH_ACK) &&
14359 			    ((thflags & (TH_CWR | TH_ECE)) == (TH_CWR | TH_ECE)) &&
14360 			    ((V_tcp_do_ecn == 1) || (V_tcp_do_ecn == 2))) {
14361 				tp->t_flags2 |= TF2_ECN_PERMIT;
14362 				tp->t_flags2 |= TF2_ECN_SND_ECE;
14363 				TCPSTAT_INC(tcps_ecn_shs);
14364 			}
14365 			if ((to.to_flags & TOF_SCALE) &&
14366 			    (tp->t_flags & TF_REQ_SCALE)) {
14367 				tp->t_flags |= TF_RCVD_SCALE;
14368 				tp->snd_scale = to.to_wscale;
14369 			} else
14370 				tp->t_flags &= ~TF_REQ_SCALE;
14371 			/*
14372 			 * Initial send window.  It will be updated with the
14373 			 * next incoming segment to the scaled value.
14374 			 */
14375 			tp->snd_wnd = th->th_win;
14376 			rack_validate_fo_sendwin_up(tp, rack);
14377 			if ((to.to_flags & TOF_TS) &&
14378 			    (tp->t_flags & TF_REQ_TSTMP)) {
14379 				tp->t_flags |= TF_RCVD_TSTMP;
14380 				tp->ts_recent = to.to_tsval;
14381 				tp->ts_recent_age = cts;
14382 			} else
14383 				tp->t_flags &= ~TF_REQ_TSTMP;
14384 			if (to.to_flags & TOF_MSS) {
14385 				tcp_mss(tp, to.to_mss);
14386 			}
14387 			if ((tp->t_flags & TF_SACK_PERMIT) &&
14388 			    (to.to_flags & TOF_SACKPERM) == 0)
14389 				tp->t_flags &= ~TF_SACK_PERMIT;
14390 			if (IS_FASTOPEN(tp->t_flags)) {
14391 				if (to.to_flags & TOF_FASTOPEN) {
14392 					uint16_t mss;
14393 
14394 					if (to.to_flags & TOF_MSS)
14395 						mss = to.to_mss;
14396 					else
14397 						if ((tp->t_inpcb->inp_vflag & INP_IPV6) != 0)
14398 							mss = TCP6_MSS;
14399 						else
14400 							mss = TCP_MSS;
14401 					tcp_fastopen_update_cache(tp, mss,
14402 					    to.to_tfo_len, to.to_tfo_cookie);
14403 				} else
14404 					tcp_fastopen_disable_path(tp);
14405 			}
14406 		}
14407 		/*
14408 		 * At this point we are at the initial call. Here we decide
14409 		 * if we are doing RACK or not. We do this by seeing if
14410 		 * TF_SACK_PERMIT is set and the sack-not-required is clear.
14411 		 * The code now does do dup-ack counting so if you don't
14412 		 * switch back you won't get rack & TLP, but you will still
14413 		 * get this stack.
14414 		 */
14415 
14416 		if ((rack_sack_not_required == 0) &&
14417 		    ((tp->t_flags & TF_SACK_PERMIT) == 0)) {
14418 			tcp_switch_back_to_default(tp);
14419 			(*tp->t_fb->tfb_tcp_do_segment) (m, th, so, tp, drop_hdrlen,
14420 			    tlen, iptos);
14421 #ifdef TCP_ACCOUNTING
14422 			sched_unpin();
14423 #endif
14424 			return (1);
14425 		}
14426 		tcp_set_hpts(tp->t_inpcb);
14427 		sack_filter_clear(&rack->r_ctl.rack_sf, th->th_ack);
14428 	}
14429 	if (thflags & TH_FIN)
14430 		tcp_log_end_status(tp, TCP_EI_STATUS_CLIENT_FIN);
14431 	us_cts = tcp_tv_to_usectick(&rack->r_ctl.act_rcv_time);
14432 	if ((rack->rc_gp_dyn_mul) &&
14433 	    (rack->use_fixed_rate == 0) &&
14434 	    (rack->rc_always_pace)) {
14435 		/* Check in on probertt */
14436 		rack_check_probe_rtt(rack, us_cts);
14437 	}
14438 	rack_clear_rate_sample(rack);
14439 	if (rack->forced_ack) {
14440 		uint32_t us_rtt;
14441 
14442 		/*
14443 		 * A persist or keep-alive was forced out, update our
14444 		 * min rtt time. Note we do not worry about lost
14445 		 * retransmissions since KEEP-ALIVES and persists
14446 		 * are usually way long on times of sending (though
14447 		 * if we were really paranoid or worried we could
14448 		 * at least use timestamps if available to validate).
14449 		 */
14450 		rack->forced_ack = 0;
14451 		us_rtt = us_cts - rack->r_ctl.forced_ack_ts;
14452 		if (us_rtt == 0)
14453 			us_rtt = 1;
14454 		rack_apply_updated_usrtt(rack, us_rtt, us_cts);
14455 		tcp_rack_xmit_timer(rack, us_rtt, 0, us_rtt, 3, NULL, 1);
14456 	}
14457 	/*
14458 	 * This is the one exception case where we set the rack state
14459 	 * always. All other times (timers etc) we must have a rack-state
14460 	 * set (so we assure we have done the checks above for SACK).
14461 	 */
14462 	rack->r_ctl.rc_rcvtime = cts;
14463 	if (rack->r_state != tp->t_state)
14464 		rack_set_state(tp, rack);
14465 	if (SEQ_GT(th->th_ack, tp->snd_una) &&
14466 	    (rsm = RB_MIN(rack_rb_tree_head, &rack->r_ctl.rc_mtree)) != NULL)
14467 		kern_prefetch(rsm, &prev_state);
14468 	prev_state = rack->r_state;
14469 	retval = (*rack->r_substate) (m, th, so,
14470 	    tp, &to, drop_hdrlen,
14471 	    tlen, tiwin, thflags, nxt_pkt, iptos);
14472 #ifdef INVARIANTS
14473 	if ((retval == 0) &&
14474 	    (tp->t_inpcb == NULL)) {
14475 		panic("retval:%d tp:%p t_inpcb:NULL state:%d",
14476 		    retval, tp, prev_state);
14477 	}
14478 #endif
14479 	if (retval == 0) {
14480 		/*
14481 		 * If retval is 1 the tcb is unlocked and most likely the tp
14482 		 * is gone.
14483 		 */
14484 		INP_WLOCK_ASSERT(tp->t_inpcb);
14485 		if ((rack->rc_gp_dyn_mul) &&
14486 		    (rack->rc_always_pace) &&
14487 		    (rack->use_fixed_rate == 0) &&
14488 		    rack->in_probe_rtt &&
14489 		    (rack->r_ctl.rc_time_probertt_starts == 0)) {
14490 			/*
14491 			 * If we are going for target, lets recheck before
14492 			 * we output.
14493 			 */
14494 			rack_check_probe_rtt(rack, us_cts);
14495 		}
14496 		if (rack->set_pacing_done_a_iw == 0) {
14497 			/* How much has been acked? */
14498 			if ((tp->snd_una - tp->iss) > (ctf_fixed_maxseg(tp) * 10)) {
14499 				/* We have enough to set in the pacing segment size */
14500 				rack->set_pacing_done_a_iw = 1;
14501 				rack_set_pace_segments(tp, rack, __LINE__, NULL);
14502 			}
14503 		}
14504 		tcp_rack_xmit_timer_commit(rack, tp);
14505 #ifdef TCP_ACCOUNTING
14506 		/*
14507 		 * If we set the ack_val_se to what ack processing we are doing
14508 		 * we also want to track how many cycles we burned. Note
14509 		 * the bits after tcp_output we let be "free". This is because
14510 		 * we are also tracking the tcp_output times as well. Note the
14511 		 * use of 0xf here since we only have 11 counter (0 - 0xa) and
14512 		 * 0xf cannot be returned and is what we initialize it too to
14513 		 * indicate we are not doing the tabulations.
14514 		 */
14515 		if (ack_val_set != 0xf) {
14516 			uint64_t crtsc;
14517 
14518 			crtsc = get_cyclecount();
14519 			counter_u64_add(tcp_proc_time[ack_val_set] , (crtsc - ts_val));
14520 			if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
14521 				tp->tcp_proc_time[ack_val_set] += (crtsc - ts_val);
14522 			}
14523 		}
14524 #endif
14525 		if (nxt_pkt == 0) {
14526 			if ((rack->r_wanted_output != 0) || (rack->r_fast_output != 0)) {
14527 do_output_now:
14528 				did_out = 1;
14529 				(void)tp->t_fb->tfb_tcp_output(tp);
14530 			}
14531 			rack_start_hpts_timer(rack, tp, cts, 0, 0, 0);
14532 			rack_free_trim(rack);
14533 		}
14534 		/* Update any rounds needed */
14535 		if (SEQ_GEQ(tp->snd_una, rack->r_ctl.roundends)) {
14536 			rack->r_ctl.current_round++;
14537 			rack->r_ctl.roundends = tp->snd_max;
14538 			if (CC_ALGO(tp)->newround != NULL) {
14539 				CC_ALGO(tp)->newround(tp->ccv, rack->r_ctl.current_round);
14540 			}
14541 		}
14542 		if ((nxt_pkt == 0) &&
14543 		    ((rack->r_ctl.rc_hpts_flags & PACE_TMR_MASK) == 0) &&
14544 		    (SEQ_GT(tp->snd_max, tp->snd_una) ||
14545 		     (tp->t_flags & TF_DELACK) ||
14546 		     ((V_tcp_always_keepalive || rack->rc_inp->inp_socket->so_options & SO_KEEPALIVE) &&
14547 		      (tp->t_state <= TCPS_CLOSING)))) {
14548 			/* We could not send (probably in the hpts but stopped the timer earlier)? */
14549 			if ((tp->snd_max == tp->snd_una) &&
14550 			    ((tp->t_flags & TF_DELACK) == 0) &&
14551 			    (rack->rc_inp->inp_in_hpts) &&
14552 			    (rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT)) {
14553 				/* keep alive not needed if we are hptsi output yet */
14554 				;
14555 			} else {
14556 				int late = 0;
14557 				if (rack->rc_inp->inp_in_hpts) {
14558 					if (rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT) {
14559 						us_cts = tcp_get_usecs(NULL);
14560 						if (TSTMP_GT(rack->r_ctl.rc_last_output_to, us_cts)) {
14561 							rack->r_early = 1;
14562 							rack->r_ctl.rc_agg_early += (rack->r_ctl.rc_last_output_to - us_cts);
14563 						} else
14564 							late = 1;
14565 						rack->r_ctl.rc_hpts_flags &= ~PACE_PKT_OUTPUT;
14566 					}
14567 					tcp_hpts_remove(tp->t_inpcb, HPTS_REMOVE_OUTPUT);
14568 				}
14569 				if (late && (did_out == 0)) {
14570 					/*
14571 					 * We are late in the sending
14572 					 * and we did not call the output
14573 					 * (this probably should not happen).
14574 					 */
14575 					goto do_output_now;
14576 				}
14577 				rack_start_hpts_timer(rack, tp, tcp_get_usecs(NULL), 0, 0, 0);
14578 			}
14579 			way_out = 1;
14580 		} else if (nxt_pkt == 0) {
14581 			/* Do we have the correct timer running? */
14582 			rack_timer_audit(tp, rack, &so->so_snd);
14583 			way_out = 2;
14584 		}
14585 	done_with_input:
14586 		rack_log_doseg_done(rack, cts, nxt_pkt, did_out, way_out, max(1, nsegs));
14587 		if (did_out)
14588 			rack->r_wanted_output = 0;
14589 #ifdef INVARIANTS
14590 		if (tp->t_inpcb == NULL) {
14591 			panic("OP:%d retval:%d tp:%p t_inpcb:NULL state:%d",
14592 			      did_out,
14593 			      retval, tp, prev_state);
14594 		}
14595 #endif
14596 #ifdef TCP_ACCOUNTING
14597 	} else {
14598 		/*
14599 		 * Track the time (see above).
14600 		 */
14601 		if (ack_val_set != 0xf) {
14602 			uint64_t crtsc;
14603 
14604 			crtsc = get_cyclecount();
14605 			counter_u64_add(tcp_proc_time[ack_val_set] , (crtsc - ts_val));
14606 			/*
14607 			 * Note we *DO NOT* increment the per-tcb counters since
14608 			 * in the else the TP may be gone!!
14609 			 */
14610 		}
14611 #endif
14612 	}
14613 #ifdef TCP_ACCOUNTING
14614 	sched_unpin();
14615 #endif
14616 	return (retval);
14617 }
14618 
14619 void
14620 rack_do_segment(struct mbuf *m, struct tcphdr *th, struct socket *so,
14621     struct tcpcb *tp, int32_t drop_hdrlen, int32_t tlen, uint8_t iptos)
14622 {
14623 	struct timeval tv;
14624 
14625 	/* First lets see if we have old packets */
14626 	if (tp->t_in_pkt) {
14627 		if (ctf_do_queued_segments(so, tp, 1)) {
14628 			m_freem(m);
14629 			return;
14630 		}
14631 	}
14632 	if (m->m_flags & M_TSTMP_LRO) {
14633 		tv.tv_sec = m->m_pkthdr.rcv_tstmp /1000000000;
14634 		tv.tv_usec = (m->m_pkthdr.rcv_tstmp % 1000000000)/1000;
14635 	} else {
14636 		/* Should not be should we kassert instead? */
14637 		tcp_get_usecs(&tv);
14638 	}
14639 	if (rack_do_segment_nounlock(m, th, so, tp,
14640 				     drop_hdrlen, tlen, iptos, 0, &tv) == 0) {
14641 		INP_WUNLOCK(tp->t_inpcb);
14642 	}
14643 }
14644 
14645 struct rack_sendmap *
14646 tcp_rack_output(struct tcpcb *tp, struct tcp_rack *rack, uint32_t tsused)
14647 {
14648 	struct rack_sendmap *rsm = NULL;
14649 	int32_t idx;
14650 	uint32_t srtt = 0, thresh = 0, ts_low = 0;
14651 
14652 	/* Return the next guy to be re-transmitted */
14653 	if (RB_EMPTY(&rack->r_ctl.rc_mtree)) {
14654 		return (NULL);
14655 	}
14656 	if (tp->t_flags & TF_SENTFIN) {
14657 		/* retran the end FIN? */
14658 		return (NULL);
14659 	}
14660 	/* ok lets look at this one */
14661 	rsm = TAILQ_FIRST(&rack->r_ctl.rc_tmap);
14662 	if (rsm && ((rsm->r_flags & RACK_ACKED) == 0)) {
14663 		goto check_it;
14664 	}
14665 	rsm = rack_find_lowest_rsm(rack);
14666 	if (rsm == NULL) {
14667 		return (NULL);
14668 	}
14669 check_it:
14670 	if (((rack->rc_tp->t_flags & TF_SACK_PERMIT) == 0) &&
14671 	    (rsm->r_dupack >= DUP_ACK_THRESHOLD)) {
14672 		/*
14673 		 * No sack so we automatically do the 3 strikes and
14674 		 * retransmit (no rack timer would be started).
14675 		 */
14676 
14677 		return (rsm);
14678 	}
14679 	if (rsm->r_flags & RACK_ACKED) {
14680 		return (NULL);
14681 	}
14682 	if (((rsm->r_flags & RACK_SACK_PASSED) == 0) &&
14683 	    (rsm->r_dupack < DUP_ACK_THRESHOLD)) {
14684 		/* Its not yet ready */
14685 		return (NULL);
14686 	}
14687 	srtt = rack_grab_rtt(tp, rack);
14688 	idx = rsm->r_rtr_cnt - 1;
14689 	ts_low = (uint32_t)rsm->r_tim_lastsent[idx];
14690 	thresh = rack_calc_thresh_rack(rack, srtt, tsused);
14691 	if ((tsused == ts_low) ||
14692 	    (TSTMP_LT(tsused, ts_low))) {
14693 		/* No time since sending */
14694 		return (NULL);
14695 	}
14696 	if ((tsused - ts_low) < thresh) {
14697 		/* It has not been long enough yet */
14698 		return (NULL);
14699 	}
14700 	if ((rsm->r_dupack >= DUP_ACK_THRESHOLD) ||
14701 	    ((rsm->r_flags & RACK_SACK_PASSED) &&
14702 	     (rack->sack_attack_disable == 0))) {
14703 		/*
14704 		 * We have passed the dup-ack threshold <or>
14705 		 * a SACK has indicated this is missing.
14706 		 * Note that if you are a declared attacker
14707 		 * it is only the dup-ack threshold that
14708 		 * will cause retransmits.
14709 		 */
14710 		/* log retransmit reason */
14711 		rack_log_retran_reason(rack, rsm, (tsused - ts_low), thresh, 1);
14712 		rack->r_fast_output = 0;
14713 		return (rsm);
14714 	}
14715 	return (NULL);
14716 }
14717 
14718 static void
14719 rack_log_pacing_delay_calc(struct tcp_rack *rack, uint32_t len, uint32_t slot,
14720 			   uint64_t bw_est, uint64_t bw, uint64_t len_time, int method,
14721 			   int line, struct rack_sendmap *rsm, uint8_t quality)
14722 {
14723 	if (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
14724 		union tcp_log_stackspecific log;
14725 		struct timeval tv;
14726 
14727 		memset(&log, 0, sizeof(log));
14728 		log.u_bbr.flex1 = slot;
14729 		log.u_bbr.flex2 = len;
14730 		log.u_bbr.flex3 = rack->r_ctl.rc_pace_min_segs;
14731 		log.u_bbr.flex4 = rack->r_ctl.rc_pace_max_segs;
14732 		log.u_bbr.flex5 = rack->r_ctl.rack_per_of_gp_ss;
14733 		log.u_bbr.flex6 = rack->r_ctl.rack_per_of_gp_ca;
14734 		log.u_bbr.use_lt_bw = rack->rc_ack_can_sendout_data;
14735 		log.u_bbr.use_lt_bw <<= 1;
14736 		log.u_bbr.use_lt_bw |= rack->r_late;
14737 		log.u_bbr.use_lt_bw <<= 1;
14738 		log.u_bbr.use_lt_bw |= rack->r_early;
14739 		log.u_bbr.use_lt_bw <<= 1;
14740 		log.u_bbr.use_lt_bw |= rack->app_limited_needs_set;
14741 		log.u_bbr.use_lt_bw <<= 1;
14742 		log.u_bbr.use_lt_bw |= rack->rc_gp_filled;
14743 		log.u_bbr.use_lt_bw <<= 1;
14744 		log.u_bbr.use_lt_bw |= rack->measure_saw_probe_rtt;
14745 		log.u_bbr.use_lt_bw <<= 1;
14746 		log.u_bbr.use_lt_bw |= rack->in_probe_rtt;
14747 		log.u_bbr.use_lt_bw <<= 1;
14748 		log.u_bbr.use_lt_bw |= rack->gp_ready;
14749 		log.u_bbr.pkt_epoch = line;
14750 		log.u_bbr.epoch = rack->r_ctl.rc_agg_delayed;
14751 		log.u_bbr.lt_epoch = rack->r_ctl.rc_agg_early;
14752 		log.u_bbr.applimited = rack->r_ctl.rack_per_of_gp_rec;
14753 		log.u_bbr.bw_inuse = bw_est;
14754 		log.u_bbr.delRate = bw;
14755 		if (rack->r_ctl.gp_bw == 0)
14756 			log.u_bbr.cur_del_rate = 0;
14757 		else
14758 			log.u_bbr.cur_del_rate = rack_get_bw(rack);
14759 		log.u_bbr.rttProp = len_time;
14760 		log.u_bbr.pkts_out = rack->r_ctl.rc_rack_min_rtt;
14761 		log.u_bbr.lost = rack->r_ctl.rc_probertt_sndmax_atexit;
14762 		log.u_bbr.pacing_gain = rack_get_output_gain(rack, rsm);
14763 		if (rack->r_ctl.cwnd_to_use < rack->rc_tp->snd_ssthresh) {
14764 			/* We are in slow start */
14765 			log.u_bbr.flex7 = 1;
14766 		} else {
14767 			/* we are on congestion avoidance */
14768 			log.u_bbr.flex7 = 0;
14769 		}
14770 		log.u_bbr.flex8 = method;
14771 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
14772 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
14773 		log.u_bbr.cwnd_gain = rack->rc_gp_saw_rec;
14774 		log.u_bbr.cwnd_gain <<= 1;
14775 		log.u_bbr.cwnd_gain |= rack->rc_gp_saw_ss;
14776 		log.u_bbr.cwnd_gain <<= 1;
14777 		log.u_bbr.cwnd_gain |= rack->rc_gp_saw_ca;
14778 		log.u_bbr.bbr_substate = quality;
14779 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
14780 		    &rack->rc_inp->inp_socket->so_rcv,
14781 		    &rack->rc_inp->inp_socket->so_snd,
14782 		    BBR_LOG_HPTSI_CALC, 0,
14783 		    0, &log, false, &tv);
14784 	}
14785 }
14786 
14787 static uint32_t
14788 rack_get_pacing_len(struct tcp_rack *rack, uint64_t bw, uint32_t mss)
14789 {
14790 	uint32_t new_tso, user_max;
14791 
14792 	user_max = rack->rc_user_set_max_segs * mss;
14793 	if (rack->rc_force_max_seg) {
14794 		return (user_max);
14795 	}
14796 	if (rack->use_fixed_rate &&
14797 	    ((rack->r_ctl.crte == NULL) ||
14798 	     (bw != rack->r_ctl.crte->rate))) {
14799 		/* Use the user mss since we are not exactly matched */
14800 		return (user_max);
14801 	}
14802 	new_tso = tcp_get_pacing_burst_size(rack->rc_tp, bw, mss, rack_pace_one_seg, rack->r_ctl.crte, NULL);
14803 	if (new_tso > user_max)
14804 		new_tso = user_max;
14805 	return (new_tso);
14806 }
14807 
14808 static int32_t
14809 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)
14810 {
14811 	uint64_t lentim, fill_bw;
14812 
14813 	/* Lets first see if we are full, if so continue with normal rate */
14814 	rack->r_via_fill_cw = 0;
14815 	if (ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked) > rack->r_ctl.cwnd_to_use)
14816 		return (slot);
14817 	if ((ctf_outstanding(rack->rc_tp) + (segsiz-1)) > rack->rc_tp->snd_wnd)
14818 		return (slot);
14819 	if (rack->r_ctl.rc_last_us_rtt == 0)
14820 		return (slot);
14821 	if (rack->rc_pace_fill_if_rttin_range &&
14822 	    (rack->r_ctl.rc_last_us_rtt >=
14823 	     (get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt) * rack->rtt_limit_mul))) {
14824 		/* The rtt is huge, N * smallest, lets not fill */
14825 		return (slot);
14826 	}
14827 	/*
14828 	 * first lets calculate the b/w based on the last us-rtt
14829 	 * and the sndwnd.
14830 	 */
14831 	fill_bw = rack->r_ctl.cwnd_to_use;
14832 	/* Take the rwnd if its smaller */
14833 	if (fill_bw > rack->rc_tp->snd_wnd)
14834 		fill_bw = rack->rc_tp->snd_wnd;
14835 	if (rack->r_fill_less_agg) {
14836 		/*
14837 		 * Now take away the inflight (this will reduce our
14838 		 * aggressiveness and yeah, if we get that much out in 1RTT
14839 		 * we will have had acks come back and still be behind).
14840 		 */
14841 		fill_bw -= ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
14842 	}
14843 	/* Now lets make it into a b/w */
14844 	fill_bw *= (uint64_t)HPTS_USEC_IN_SEC;
14845 	fill_bw /= (uint64_t)rack->r_ctl.rc_last_us_rtt;
14846 	/* We are below the min b/w */
14847 	if (non_paced)
14848 		*rate_wanted = fill_bw;
14849 	if ((fill_bw < RACK_MIN_BW) || (fill_bw < *rate_wanted))
14850 		return (slot);
14851 	if (rack->r_ctl.bw_rate_cap && (fill_bw > rack->r_ctl.bw_rate_cap))
14852 		fill_bw = rack->r_ctl.bw_rate_cap;
14853 	rack->r_via_fill_cw = 1;
14854 	if (rack->r_rack_hw_rate_caps &&
14855 	    (rack->r_ctl.crte != NULL)) {
14856 		uint64_t high_rate;
14857 
14858 		high_rate = tcp_hw_highest_rate(rack->r_ctl.crte);
14859 		if (fill_bw > high_rate) {
14860 			/* We are capping bw at the highest rate table entry */
14861 			if (*rate_wanted > high_rate) {
14862 				/* The original rate was also capped */
14863 				rack->r_via_fill_cw = 0;
14864 			}
14865 			rack_log_hdwr_pacing(rack,
14866 					     fill_bw, high_rate, __LINE__,
14867 					     0, 3);
14868 			fill_bw = high_rate;
14869 			if (capped)
14870 				*capped = 1;
14871 		}
14872 	} else if ((rack->r_ctl.crte == NULL) &&
14873 		   (rack->rack_hdrw_pacing == 0) &&
14874 		   (rack->rack_hdw_pace_ena) &&
14875 		   rack->r_rack_hw_rate_caps &&
14876 		   (rack->rack_attempt_hdwr_pace == 0) &&
14877 		   (rack->rc_inp->inp_route.ro_nh != NULL) &&
14878 		   (rack->rc_inp->inp_route.ro_nh->nh_ifp != NULL)) {
14879 		/*
14880 		 * Ok we may have a first attempt that is greater than our top rate
14881 		 * lets check.
14882 		 */
14883 		uint64_t high_rate;
14884 
14885 		high_rate = tcp_hw_highest_rate_ifp(rack->rc_inp->inp_route.ro_nh->nh_ifp, rack->rc_inp);
14886 		if (high_rate) {
14887 			if (fill_bw > high_rate) {
14888 				fill_bw = high_rate;
14889 				if (capped)
14890 					*capped = 1;
14891 			}
14892 		}
14893 	}
14894 	/*
14895 	 * Ok fill_bw holds our mythical b/w to fill the cwnd
14896 	 * in a rtt, what does that time wise equate too?
14897 	 */
14898 	lentim = (uint64_t)(len) * (uint64_t)HPTS_USEC_IN_SEC;
14899 	lentim /= fill_bw;
14900 	*rate_wanted = fill_bw;
14901 	if (non_paced || (lentim < slot)) {
14902 		rack_log_pacing_delay_calc(rack, len, slot, fill_bw,
14903 					   0, lentim, 12, __LINE__, NULL, 0);
14904 		return ((int32_t)lentim);
14905 	} else
14906 		return (slot);
14907 }
14908 
14909 static int32_t
14910 rack_get_pacing_delay(struct tcp_rack *rack, struct tcpcb *tp, uint32_t len, struct rack_sendmap *rsm, uint32_t segsiz)
14911 {
14912 	uint64_t srtt;
14913 	int32_t slot = 0;
14914 	int can_start_hw_pacing = 1;
14915 	int err;
14916 
14917 	if (rack->rc_always_pace == 0) {
14918 		/*
14919 		 * We use the most optimistic possible cwnd/srtt for
14920 		 * sending calculations. This will make our
14921 		 * calculation anticipate getting more through
14922 		 * quicker then possible. But thats ok we don't want
14923 		 * the peer to have a gap in data sending.
14924 		 */
14925 		uint64_t cwnd, tr_perms = 0;
14926 		int32_t reduce = 0;
14927 
14928 	old_method:
14929 		/*
14930 		 * We keep no precise pacing with the old method
14931 		 * instead we use the pacer to mitigate bursts.
14932 		 */
14933 		if (rack->r_ctl.rc_rack_min_rtt)
14934 			srtt = rack->r_ctl.rc_rack_min_rtt;
14935 		else
14936 			srtt = max(tp->t_srtt, 1);
14937 		if (rack->r_ctl.rc_rack_largest_cwnd)
14938 			cwnd = rack->r_ctl.rc_rack_largest_cwnd;
14939 		else
14940 			cwnd = rack->r_ctl.cwnd_to_use;
14941 		/* Inflate cwnd by 1000 so srtt of usecs is in ms */
14942 		tr_perms = (cwnd * 1000) / srtt;
14943 		if (tr_perms == 0) {
14944 			tr_perms = ctf_fixed_maxseg(tp);
14945 		}
14946 		/*
14947 		 * Calculate how long this will take to drain, if
14948 		 * the calculation comes out to zero, thats ok we
14949 		 * will use send_a_lot to possibly spin around for
14950 		 * more increasing tot_len_this_send to the point
14951 		 * that its going to require a pace, or we hit the
14952 		 * cwnd. Which in that case we are just waiting for
14953 		 * a ACK.
14954 		 */
14955 		slot = len / tr_perms;
14956 		/* Now do we reduce the time so we don't run dry? */
14957 		if (slot && rack_slot_reduction) {
14958 			reduce = (slot / rack_slot_reduction);
14959 			if (reduce < slot) {
14960 				slot -= reduce;
14961 			} else
14962 				slot = 0;
14963 		}
14964 		slot *= HPTS_USEC_IN_MSEC;
14965 		if (rack->rc_pace_to_cwnd) {
14966 			uint64_t rate_wanted = 0;
14967 
14968 			slot = pace_to_fill_cwnd(rack, slot, len, segsiz, NULL, &rate_wanted, 1);
14969 			rack->rc_ack_can_sendout_data = 1;
14970 			rack_log_pacing_delay_calc(rack, len, slot, rate_wanted, 0, 0, 14, __LINE__, NULL, 0);
14971 		} else
14972 			rack_log_pacing_delay_calc(rack, len, slot, tr_perms, reduce, 0, 7, __LINE__, NULL, 0);
14973 	} else {
14974 		uint64_t bw_est, res, lentim, rate_wanted;
14975 		uint32_t orig_val, segs, oh;
14976 		int capped = 0;
14977 		int prev_fill;
14978 
14979 		if ((rack->r_rr_config == 1) && rsm) {
14980 			return (rack->r_ctl.rc_min_to);
14981 		}
14982 		if (rack->use_fixed_rate) {
14983 			rate_wanted = bw_est = rack_get_fixed_pacing_bw(rack);
14984 		} else if ((rack->r_ctl.init_rate == 0) &&
14985 #ifdef NETFLIX_PEAKRATE
14986 			   (rack->rc_tp->t_maxpeakrate == 0) &&
14987 #endif
14988 			   (rack->r_ctl.gp_bw == 0)) {
14989 			/* no way to yet do an estimate */
14990 			bw_est = rate_wanted = 0;
14991 		} else {
14992 			bw_est = rack_get_bw(rack);
14993 			rate_wanted = rack_get_output_bw(rack, bw_est, rsm, &capped);
14994 		}
14995 		if ((bw_est == 0) || (rate_wanted == 0) ||
14996 		    ((rack->gp_ready == 0) && (rack->use_fixed_rate == 0))) {
14997 			/*
14998 			 * No way yet to make a b/w estimate or
14999 			 * our raise is set incorrectly.
15000 			 */
15001 			goto old_method;
15002 		}
15003 		/* We need to account for all the overheads */
15004 		segs = (len + segsiz - 1) / segsiz;
15005 		/*
15006 		 * We need the diff between 1514 bytes (e-mtu with e-hdr)
15007 		 * and how much data we put in each packet. Yes this
15008 		 * means we may be off if we are larger than 1500 bytes
15009 		 * or smaller. But this just makes us more conservative.
15010 		 */
15011 		if (rack_hw_rate_min &&
15012 		    (bw_est < rack_hw_rate_min))
15013 			can_start_hw_pacing = 0;
15014 		if (ETHERNET_SEGMENT_SIZE > segsiz)
15015 			oh = ETHERNET_SEGMENT_SIZE - segsiz;
15016 		else
15017 			oh = 0;
15018 		segs *= oh;
15019 		lentim = (uint64_t)(len + segs) * (uint64_t)HPTS_USEC_IN_SEC;
15020 		res = lentim / rate_wanted;
15021 		slot = (uint32_t)res;
15022 		orig_val = rack->r_ctl.rc_pace_max_segs;
15023 		if (rack->r_ctl.crte == NULL) {
15024 			/*
15025 			 * Only do this if we are not hardware pacing
15026 			 * since if we are doing hw-pacing below we will
15027 			 * set make a call after setting up or changing
15028 			 * the rate.
15029 			 */
15030 			rack_set_pace_segments(rack->rc_tp, rack, __LINE__, NULL);
15031 		} else if (rack->rc_inp->inp_snd_tag == NULL) {
15032 			/*
15033 			 * We lost our rate somehow, this can happen
15034 			 * if the interface changed underneath us.
15035 			 */
15036 			tcp_rel_pacing_rate(rack->r_ctl.crte, rack->rc_tp);
15037 			rack->r_ctl.crte = NULL;
15038 			/* Lets re-allow attempting to setup pacing */
15039 			rack->rack_hdrw_pacing = 0;
15040 			rack->rack_attempt_hdwr_pace = 0;
15041 			rack_log_hdwr_pacing(rack,
15042 					     rate_wanted, bw_est, __LINE__,
15043 					     0, 6);
15044 		}
15045 		/* Did we change the TSO size, if so log it */
15046 		if (rack->r_ctl.rc_pace_max_segs != orig_val)
15047 			rack_log_pacing_delay_calc(rack, len, slot, orig_val, 0, 0, 15, __LINE__, NULL, 0);
15048 		prev_fill = rack->r_via_fill_cw;
15049 		if ((rack->rc_pace_to_cwnd) &&
15050 		    (capped == 0) &&
15051 		    (rack->use_fixed_rate == 0) &&
15052 		    (rack->in_probe_rtt == 0) &&
15053 		    (IN_FASTRECOVERY(rack->rc_tp->t_flags) == 0)) {
15054 			/*
15055 			 * We want to pace at our rate *or* faster to
15056 			 * fill the cwnd to the max if its not full.
15057 			 */
15058 			slot = pace_to_fill_cwnd(rack, slot, (len+segs), segsiz, &capped, &rate_wanted, 0);
15059 		}
15060 		if ((rack->rc_inp->inp_route.ro_nh != NULL) &&
15061 		    (rack->rc_inp->inp_route.ro_nh->nh_ifp != NULL)) {
15062 			if ((rack->rack_hdw_pace_ena) &&
15063 			    (can_start_hw_pacing > 0) &&
15064 			    (rack->rack_hdrw_pacing == 0) &&
15065 			    (rack->rack_attempt_hdwr_pace == 0)) {
15066 				/*
15067 				 * Lets attempt to turn on hardware pacing
15068 				 * if we can.
15069 				 */
15070 				rack->rack_attempt_hdwr_pace = 1;
15071 				rack->r_ctl.crte = tcp_set_pacing_rate(rack->rc_tp,
15072 								       rack->rc_inp->inp_route.ro_nh->nh_ifp,
15073 								       rate_wanted,
15074 								       RS_PACING_GEQ,
15075 								       &err, &rack->r_ctl.crte_prev_rate);
15076 				if (rack->r_ctl.crte) {
15077 					rack->rack_hdrw_pacing = 1;
15078 					rack->r_ctl.rc_pace_max_segs = tcp_get_pacing_burst_size(tp, rate_wanted, segsiz,
15079 												 0, rack->r_ctl.crte,
15080 												 NULL);
15081 					rack_log_hdwr_pacing(rack,
15082 							     rate_wanted, rack->r_ctl.crte->rate, __LINE__,
15083 							     err, 0);
15084 					rack->r_ctl.last_hw_bw_req = rate_wanted;
15085 				} else {
15086 					counter_u64_add(rack_hw_pace_init_fail, 1);
15087 				}
15088 			} else if (rack->rack_hdrw_pacing &&
15089 				   (rack->r_ctl.last_hw_bw_req != rate_wanted)) {
15090 				/* Do we need to adjust our rate? */
15091 				const struct tcp_hwrate_limit_table *nrte;
15092 
15093 				if (rack->r_up_only &&
15094 				    (rate_wanted < rack->r_ctl.crte->rate)) {
15095 					/**
15096 					 * We have four possible states here
15097 					 * having to do with the previous time
15098 					 * and this time.
15099 					 *   previous  |  this-time
15100 					 * A)     0      |     0   -- fill_cw not in the picture
15101 					 * B)     1      |     0   -- we were doing a fill-cw but now are not
15102 					 * C)     1      |     1   -- all rates from fill_cw
15103 					 * D)     0      |     1   -- we were doing non-fill and now we are filling
15104 					 *
15105 					 * For case A, C and D we don't allow a drop. But for
15106 					 * case B where we now our on our steady rate we do
15107 					 * allow a drop.
15108 					 *
15109 					 */
15110 					if (!((prev_fill == 1) && (rack->r_via_fill_cw == 0)))
15111 						goto done_w_hdwr;
15112 				}
15113 				if ((rate_wanted > rack->r_ctl.crte->rate) ||
15114 				    (rate_wanted <= rack->r_ctl.crte_prev_rate)) {
15115 					if (rack_hw_rate_to_low &&
15116 					    (bw_est < rack_hw_rate_to_low)) {
15117 						/*
15118 						 * The pacing rate is too low for hardware, but
15119 						 * do allow hardware pacing to be restarted.
15120 						 */
15121 						rack_log_hdwr_pacing(rack,
15122 							     bw_est, rack->r_ctl.crte->rate, __LINE__,
15123 							     0, 5);
15124 						tcp_rel_pacing_rate(rack->r_ctl.crte, rack->rc_tp);
15125 						rack->r_ctl.crte = NULL;
15126 						rack->rack_attempt_hdwr_pace = 0;
15127 						rack->rack_hdrw_pacing = 0;
15128 						rack_set_pace_segments(rack->rc_tp, rack, __LINE__, &rate_wanted);
15129 						goto done_w_hdwr;
15130 					}
15131 					nrte = tcp_chg_pacing_rate(rack->r_ctl.crte,
15132 								   rack->rc_tp,
15133 								   rack->rc_inp->inp_route.ro_nh->nh_ifp,
15134 								   rate_wanted,
15135 								   RS_PACING_GEQ,
15136 								   &err, &rack->r_ctl.crte_prev_rate);
15137 					if (nrte == NULL) {
15138 						/* Lost the rate */
15139 						rack->rack_hdrw_pacing = 0;
15140 						rack->r_ctl.crte = NULL;
15141 						rack_log_hdwr_pacing(rack,
15142 								     rate_wanted, 0, __LINE__,
15143 								     err, 1);
15144 						rack_set_pace_segments(rack->rc_tp, rack, __LINE__, &rate_wanted);
15145 						counter_u64_add(rack_hw_pace_lost, 1);
15146 					} else if (nrte != rack->r_ctl.crte) {
15147 						rack->r_ctl.crte = nrte;
15148 						rack->r_ctl.rc_pace_max_segs = tcp_get_pacing_burst_size(tp, rate_wanted,
15149 													 segsiz, 0,
15150 													 rack->r_ctl.crte,
15151 													 NULL);
15152 						rack_log_hdwr_pacing(rack,
15153 								     rate_wanted, rack->r_ctl.crte->rate, __LINE__,
15154 								     err, 2);
15155 						rack->r_ctl.last_hw_bw_req = rate_wanted;
15156 					}
15157 				} else {
15158 					/* We just need to adjust the segment size */
15159 					rack_set_pace_segments(rack->rc_tp, rack, __LINE__, &rate_wanted);
15160 					rack_log_hdwr_pacing(rack,
15161 							     rate_wanted, rack->r_ctl.crte->rate, __LINE__,
15162 							     0, 4);
15163 					rack->r_ctl.last_hw_bw_req = rate_wanted;
15164 				}
15165 			}
15166 		}
15167 		if ((rack->r_ctl.crte != NULL) &&
15168 		    (rack->r_ctl.crte->rate == rate_wanted)) {
15169 			/*
15170 			 * We need to add a extra if the rates
15171 			 * are exactly matched. The idea is
15172 			 * we want the software to make sure the
15173 			 * queue is empty before adding more, this
15174 			 * gives us N MSS extra pace times where
15175 			 * N is our sysctl
15176 			 */
15177 			slot += (rack->r_ctl.crte->time_between * rack_hw_pace_extra_slots);
15178 		}
15179 done_w_hdwr:
15180 		if (rack_limit_time_with_srtt &&
15181 		    (rack->use_fixed_rate == 0) &&
15182 #ifdef NETFLIX_PEAKRATE
15183 		    (rack->rc_tp->t_maxpeakrate == 0) &&
15184 #endif
15185 		    (rack->rack_hdrw_pacing == 0)) {
15186 			/*
15187 			 * Sanity check, we do not allow the pacing delay
15188 			 * to be longer than the SRTT of the path. If it is
15189 			 * a slow path, then adding a packet should increase
15190 			 * the RTT and compensate for this i.e. the srtt will
15191 			 * be greater so the allowed pacing time will be greater.
15192 			 *
15193 			 * Note this restriction is not for where a peak rate
15194 			 * is set, we are doing fixed pacing or hardware pacing.
15195 			 */
15196 			if (rack->rc_tp->t_srtt)
15197 				srtt = rack->rc_tp->t_srtt;
15198 			else
15199 				srtt = RACK_INITIAL_RTO * HPTS_USEC_IN_MSEC;	/* its in ms convert */
15200 			if (srtt < (uint64_t)slot) {
15201 				rack_log_pacing_delay_calc(rack, srtt, slot, rate_wanted, bw_est, lentim, 99, __LINE__, NULL, 0);
15202 				slot = srtt;
15203 			}
15204 		}
15205 		rack_log_pacing_delay_calc(rack, len, slot, rate_wanted, bw_est, lentim, 2, __LINE__, rsm, 0);
15206 	}
15207 	if (rack->r_ctl.crte && (rack->r_ctl.crte->rs_num_enobufs > 0)) {
15208 		/*
15209 		 * If this rate is seeing enobufs when it
15210 		 * goes to send then either the nic is out
15211 		 * of gas or we are mis-estimating the time
15212 		 * somehow and not letting the queue empty
15213 		 * completely. Lets add to the pacing time.
15214 		 */
15215 		int hw_boost_delay;
15216 
15217 		hw_boost_delay = rack->r_ctl.crte->time_between * rack_enobuf_hw_boost_mult;
15218 		if (hw_boost_delay > rack_enobuf_hw_max)
15219 			hw_boost_delay = rack_enobuf_hw_max;
15220 		else if (hw_boost_delay < rack_enobuf_hw_min)
15221 			hw_boost_delay = rack_enobuf_hw_min;
15222 		slot += hw_boost_delay;
15223 	}
15224 	if (slot)
15225 		counter_u64_add(rack_calc_nonzero, 1);
15226 	else
15227 		counter_u64_add(rack_calc_zero, 1);
15228 	return (slot);
15229 }
15230 
15231 static void
15232 rack_start_gp_measurement(struct tcpcb *tp, struct tcp_rack *rack,
15233     tcp_seq startseq, uint32_t sb_offset)
15234 {
15235 	struct rack_sendmap *my_rsm = NULL;
15236 	struct rack_sendmap fe;
15237 
15238 	if (tp->t_state < TCPS_ESTABLISHED) {
15239 		/*
15240 		 * We don't start any measurements if we are
15241 		 * not at least established.
15242 		 */
15243 		return;
15244 	}
15245 	if (tp->t_state >= TCPS_FIN_WAIT_1) {
15246 		/*
15247 		 * We will get no more data into the SB
15248 		 * this means we need to have the data available
15249 		 * before we start a measurement.
15250 		 */
15251 
15252 		if (sbavail(&tp->t_inpcb->inp_socket->so_snd) <
15253 		    max(rc_init_window(rack),
15254 			(MIN_GP_WIN * ctf_fixed_maxseg(tp)))) {
15255 			/* Nope not enough data */
15256 			return;
15257 		}
15258 	}
15259 	tp->t_flags |= TF_GPUTINPROG;
15260 	rack->r_ctl.rc_gp_lowrtt = 0xffffffff;
15261 	rack->r_ctl.rc_gp_high_rwnd = rack->rc_tp->snd_wnd;
15262 	tp->gput_seq = startseq;
15263 	rack->app_limited_needs_set = 0;
15264 	if (rack->in_probe_rtt)
15265 		rack->measure_saw_probe_rtt = 1;
15266 	else if ((rack->measure_saw_probe_rtt) &&
15267 		 (SEQ_GEQ(tp->gput_seq, rack->r_ctl.rc_probertt_sndmax_atexit)))
15268 		rack->measure_saw_probe_rtt = 0;
15269 	if (rack->rc_gp_filled)
15270 		tp->gput_ts = tcp_tv_to_usectick(&rack->r_ctl.act_rcv_time);
15271 	else {
15272 		/* Special case initial measurement */
15273 		struct timeval tv;
15274 
15275 		tp->gput_ts = tcp_get_usecs(&tv);
15276 		rack->r_ctl.rc_gp_output_ts = rack_to_usec_ts(&tv);
15277 	}
15278 	/*
15279 	 * We take a guess out into the future,
15280 	 * if we have no measurement and no
15281 	 * initial rate, we measure the first
15282 	 * initial-windows worth of data to
15283 	 * speed up getting some GP measurement and
15284 	 * thus start pacing.
15285 	 */
15286 	if ((rack->rc_gp_filled == 0) && (rack->r_ctl.init_rate == 0)) {
15287 		rack->app_limited_needs_set = 1;
15288 		tp->gput_ack = startseq + max(rc_init_window(rack),
15289 					      (MIN_GP_WIN * ctf_fixed_maxseg(tp)));
15290 		rack_log_pacing_delay_calc(rack,
15291 					   tp->gput_seq,
15292 					   tp->gput_ack,
15293 					   0,
15294 					   tp->gput_ts,
15295 					   rack->r_ctl.rc_app_limited_cnt,
15296 					   9,
15297 					   __LINE__, NULL, 0);
15298 		return;
15299 	}
15300 	if (sb_offset) {
15301 		/*
15302 		 * We are out somewhere in the sb
15303 		 * can we use the already outstanding data?
15304 		 */
15305 		if (rack->r_ctl.rc_app_limited_cnt == 0) {
15306 			/*
15307 			 * Yes first one is good and in this case
15308 			 * the tp->gput_ts is correctly set based on
15309 			 * the last ack that arrived (no need to
15310 			 * set things up when an ack comes in).
15311 			 */
15312 			my_rsm = RB_MIN(rack_rb_tree_head, &rack->r_ctl.rc_mtree);
15313 			if ((my_rsm == NULL) ||
15314 			    (my_rsm->r_rtr_cnt != 1)) {
15315 				/* retransmission? */
15316 				goto use_latest;
15317 			}
15318 		} else {
15319 			if (rack->r_ctl.rc_first_appl == NULL) {
15320 				/*
15321 				 * If rc_first_appl is NULL
15322 				 * then the cnt should be 0.
15323 				 * This is probably an error, maybe
15324 				 * a KASSERT would be approprate.
15325 				 */
15326 				goto use_latest;
15327 			}
15328 			/*
15329 			 * If we have a marker pointer to the last one that is
15330 			 * app limited we can use that, but we need to set
15331 			 * things up so that when it gets ack'ed we record
15332 			 * the ack time (if its not already acked).
15333 			 */
15334 			rack->app_limited_needs_set = 1;
15335 			/*
15336 			 * We want to get to the rsm that is either
15337 			 * next with space i.e. over 1 MSS or the one
15338 			 * after that (after the app-limited).
15339 			 */
15340 			my_rsm = RB_NEXT(rack_rb_tree_head, &rack->r_ctl.rc_mtree,
15341 					 rack->r_ctl.rc_first_appl);
15342 			if (my_rsm) {
15343 				if ((my_rsm->r_end - my_rsm->r_start) <= ctf_fixed_maxseg(tp))
15344 					/* Have to use the next one */
15345 					my_rsm = RB_NEXT(rack_rb_tree_head, &rack->r_ctl.rc_mtree,
15346 							 my_rsm);
15347 				else {
15348 					/* Use after the first MSS of it is acked */
15349 					tp->gput_seq = my_rsm->r_start + ctf_fixed_maxseg(tp);
15350 					goto start_set;
15351 				}
15352 			}
15353 			if ((my_rsm == NULL) ||
15354 			    (my_rsm->r_rtr_cnt != 1)) {
15355 				/*
15356 				 * Either its a retransmit or
15357 				 * the last is the app-limited one.
15358 				 */
15359 				goto use_latest;
15360 			}
15361 		}
15362 		tp->gput_seq = my_rsm->r_start;
15363 start_set:
15364 		if (my_rsm->r_flags & RACK_ACKED) {
15365 			/*
15366 			 * This one has been acked use the arrival ack time
15367 			 */
15368 			tp->gput_ts = (uint32_t)my_rsm->r_ack_arrival;
15369 			rack->app_limited_needs_set = 0;
15370 		}
15371 		rack->r_ctl.rc_gp_output_ts = my_rsm->r_tim_lastsent[(my_rsm->r_rtr_cnt-1)];
15372 		tp->gput_ack = tp->gput_seq + rack_get_measure_window(tp, rack);
15373 		rack_log_pacing_delay_calc(rack,
15374 					   tp->gput_seq,
15375 					   tp->gput_ack,
15376 					   (uint64_t)my_rsm,
15377 					   tp->gput_ts,
15378 					   rack->r_ctl.rc_app_limited_cnt,
15379 					   9,
15380 					   __LINE__, NULL, 0);
15381 		return;
15382 	}
15383 
15384 use_latest:
15385 	/*
15386 	 * We don't know how long we may have been
15387 	 * idle or if this is the first-send. Lets
15388 	 * setup the flag so we will trim off
15389 	 * the first ack'd data so we get a true
15390 	 * measurement.
15391 	 */
15392 	rack->app_limited_needs_set = 1;
15393 	tp->gput_ack = startseq + rack_get_measure_window(tp, rack);
15394 	/* Find this guy so we can pull the send time */
15395 	fe.r_start = startseq;
15396 	my_rsm = RB_FIND(rack_rb_tree_head, &rack->r_ctl.rc_mtree, &fe);
15397 	if (my_rsm) {
15398 		rack->r_ctl.rc_gp_output_ts = my_rsm->r_tim_lastsent[(my_rsm->r_rtr_cnt-1)];
15399 		if (my_rsm->r_flags & RACK_ACKED) {
15400 			/*
15401 			 * Unlikely since its probably what was
15402 			 * just transmitted (but I am paranoid).
15403 			 */
15404 			tp->gput_ts = (uint32_t)my_rsm->r_ack_arrival;
15405 			rack->app_limited_needs_set = 0;
15406 		}
15407 		if (SEQ_LT(my_rsm->r_start, tp->gput_seq)) {
15408 			/* This also is unlikely */
15409 			tp->gput_seq = my_rsm->r_start;
15410 		}
15411 	} else {
15412 		/*
15413 		 * TSNH unless we have some send-map limit,
15414 		 * and even at that it should not be hitting
15415 		 * that limit (we should have stopped sending).
15416 		 */
15417 		struct timeval tv;
15418 
15419 		microuptime(&tv);
15420 		rack->r_ctl.rc_gp_output_ts = rack_to_usec_ts(&tv);
15421 	}
15422 	rack_log_pacing_delay_calc(rack,
15423 				   tp->gput_seq,
15424 				   tp->gput_ack,
15425 				   (uint64_t)my_rsm,
15426 				   tp->gput_ts,
15427 				   rack->r_ctl.rc_app_limited_cnt,
15428 				   9, __LINE__, NULL, 0);
15429 }
15430 
15431 static inline uint32_t
15432 rack_what_can_we_send(struct tcpcb *tp, struct tcp_rack *rack,  uint32_t cwnd_to_use,
15433     uint32_t avail, int32_t sb_offset)
15434 {
15435 	uint32_t len;
15436 	uint32_t sendwin;
15437 
15438 	if (tp->snd_wnd > cwnd_to_use)
15439 		sendwin = cwnd_to_use;
15440 	else
15441 		sendwin = tp->snd_wnd;
15442 	if (ctf_outstanding(tp) >= tp->snd_wnd) {
15443 		/* We never want to go over our peers rcv-window */
15444 		len = 0;
15445 	} else {
15446 		uint32_t flight;
15447 
15448 		flight = ctf_flight_size(tp, rack->r_ctl.rc_sacked);
15449 		if (flight >= sendwin) {
15450 			/*
15451 			 * We have in flight what we are allowed by cwnd (if
15452 			 * it was rwnd blocking it would have hit above out
15453 			 * >= tp->snd_wnd).
15454 			 */
15455 			return (0);
15456 		}
15457 		len = sendwin - flight;
15458 		if ((len + ctf_outstanding(tp)) > tp->snd_wnd) {
15459 			/* We would send too much (beyond the rwnd) */
15460 			len = tp->snd_wnd - ctf_outstanding(tp);
15461 		}
15462 		if ((len + sb_offset) > avail) {
15463 			/*
15464 			 * We don't have that much in the SB, how much is
15465 			 * there?
15466 			 */
15467 			len = avail - sb_offset;
15468 		}
15469 	}
15470 	return (len);
15471 }
15472 
15473 static void
15474 rack_log_fsb(struct tcp_rack *rack, struct tcpcb *tp, struct socket *so, uint32_t flags,
15475 	     unsigned ipoptlen, int32_t orig_len, int32_t len, int error,
15476 	     int rsm_is_null, int optlen, int line, uint16_t mode)
15477 {
15478 	if (tp->t_logstate != TCP_LOG_STATE_OFF) {
15479 		union tcp_log_stackspecific log;
15480 		struct timeval tv;
15481 
15482 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
15483 		log.u_bbr.inhpts = rack->rc_inp->inp_in_hpts;
15484 		log.u_bbr.ininput = rack->rc_inp->inp_in_input;
15485 		log.u_bbr.flex1 = error;
15486 		log.u_bbr.flex2 = flags;
15487 		log.u_bbr.flex3 = rsm_is_null;
15488 		log.u_bbr.flex4 = ipoptlen;
15489 		log.u_bbr.flex5 = tp->rcv_numsacks;
15490 		log.u_bbr.flex6 = rack->r_ctl.rc_agg_early;
15491 		log.u_bbr.flex7 = optlen;
15492 		log.u_bbr.flex8 = rack->r_fsb_inited;
15493 		log.u_bbr.applimited = rack->r_fast_output;
15494 		log.u_bbr.bw_inuse = rack_get_bw(rack);
15495 		log.u_bbr.pacing_gain = rack_get_output_gain(rack, NULL);
15496 		log.u_bbr.cwnd_gain = mode;
15497 		log.u_bbr.pkts_out = orig_len;
15498 		log.u_bbr.lt_epoch = len;
15499 		log.u_bbr.delivered = line;
15500 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
15501 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
15502 		tcp_log_event_(tp, NULL, &so->so_rcv, &so->so_snd, TCP_LOG_FSB, 0,
15503 			       len, &log, false, NULL, NULL, 0, &tv);
15504 	}
15505 }
15506 
15507 
15508 static struct mbuf *
15509 rack_fo_base_copym(struct mbuf *the_m, uint32_t the_off, int32_t *plen,
15510 		   struct rack_fast_send_blk *fsb,
15511 		   int32_t seglimit, int32_t segsize, int hw_tls)
15512 {
15513 #ifdef KERN_TLS
15514 	struct ktls_session *tls, *ntls;
15515 	struct mbuf *start;
15516 #endif
15517 	struct mbuf *m, *n, **np, *smb;
15518 	struct mbuf *top;
15519 	int32_t off, soff;
15520 	int32_t len = *plen;
15521 	int32_t fragsize;
15522 	int32_t len_cp = 0;
15523 	uint32_t mlen, frags;
15524 
15525 	soff = off = the_off;
15526 	smb = m = the_m;
15527 	np = &top;
15528 	top = NULL;
15529 #ifdef KERN_TLS
15530 	if (hw_tls && (m->m_flags & M_EXTPG))
15531 		tls = m->m_epg_tls;
15532 	else
15533 		tls = NULL;
15534 	start = m;
15535 #endif
15536 	while (len > 0) {
15537 		if (m == NULL) {
15538 			*plen = len_cp;
15539 			break;
15540 		}
15541 #ifdef KERN_TLS
15542 		if (hw_tls) {
15543 			if (m->m_flags & M_EXTPG)
15544 				ntls = m->m_epg_tls;
15545 			else
15546 				ntls = NULL;
15547 
15548 			/*
15549 			 * Avoid mixing TLS records with handshake
15550 			 * data or TLS records from different
15551 			 * sessions.
15552 			 */
15553 			if (tls != ntls) {
15554 				MPASS(m != start);
15555 				*plen = len_cp;
15556 				break;
15557 			}
15558 		}
15559 #endif
15560 		mlen = min(len, m->m_len - off);
15561 		if (seglimit) {
15562 			/*
15563 			 * For M_EXTPG mbufs, add 3 segments
15564 			 * + 1 in case we are crossing page boundaries
15565 			 * + 2 in case the TLS hdr/trailer are used
15566 			 * It is cheaper to just add the segments
15567 			 * than it is to take the cache miss to look
15568 			 * at the mbuf ext_pgs state in detail.
15569 			 */
15570 			if (m->m_flags & M_EXTPG) {
15571 				fragsize = min(segsize, PAGE_SIZE);
15572 				frags = 3;
15573 			} else {
15574 				fragsize = segsize;
15575 				frags = 0;
15576 			}
15577 
15578 			/* Break if we really can't fit anymore. */
15579 			if ((frags + 1) >= seglimit) {
15580 				*plen =	len_cp;
15581 				break;
15582 			}
15583 
15584 			/*
15585 			 * Reduce size if you can't copy the whole
15586 			 * mbuf. If we can't copy the whole mbuf, also
15587 			 * adjust len so the loop will end after this
15588 			 * mbuf.
15589 			 */
15590 			if ((frags + howmany(mlen, fragsize)) >= seglimit) {
15591 				mlen = (seglimit - frags - 1) * fragsize;
15592 				len = mlen;
15593 				*plen = len_cp + len;
15594 			}
15595 			frags += howmany(mlen, fragsize);
15596 			if (frags == 0)
15597 				frags++;
15598 			seglimit -= frags;
15599 			KASSERT(seglimit > 0,
15600 			    ("%s: seglimit went too low", __func__));
15601 		}
15602 		n = m_get(M_NOWAIT, m->m_type);
15603 		*np = n;
15604 		if (n == NULL)
15605 			goto nospace;
15606 		n->m_len = mlen;
15607 		soff += mlen;
15608 		len_cp += n->m_len;
15609 		if (m->m_flags & (M_EXT|M_EXTPG)) {
15610 			n->m_data = m->m_data + off;
15611 			mb_dupcl(n, m);
15612 		} else {
15613 			bcopy(mtod(m, caddr_t)+off, mtod(n, caddr_t),
15614 			    (u_int)n->m_len);
15615 		}
15616 		len -= n->m_len;
15617 		off = 0;
15618 		m = m->m_next;
15619 		np = &n->m_next;
15620 		if (len || (soff == smb->m_len)) {
15621 			/*
15622 			 * We have more so we move forward  or
15623 			 * we have consumed the entire mbuf and
15624 			 * len has fell to 0.
15625 			 */
15626 			soff = 0;
15627 			smb = m;
15628 		}
15629 
15630 	}
15631 	if (fsb != NULL) {
15632 		fsb->m = smb;
15633 		fsb->off = soff;
15634 		if (smb) {
15635 			/*
15636 			 * Save off the size of the mbuf. We do
15637 			 * this so that we can recognize when it
15638 			 * has been trimmed by sbcut() as acks
15639 			 * come in.
15640 			 */
15641 			fsb->o_m_len = smb->m_len;
15642 		} else {
15643 			/*
15644 			 * This is the case where the next mbuf went to NULL. This
15645 			 * means with this copy we have sent everything in the sb.
15646 			 * In theory we could clear the fast_output flag, but lets
15647 			 * not since its possible that we could get more added
15648 			 * and acks that call the extend function which would let
15649 			 * us send more.
15650 			 */
15651 			fsb->o_m_len = 0;
15652 		}
15653 	}
15654 	return (top);
15655 nospace:
15656 	if (top)
15657 		m_freem(top);
15658 	return (NULL);
15659 
15660 }
15661 
15662 /*
15663  * This is a copy of m_copym(), taking the TSO segment size/limit
15664  * constraints into account, and advancing the sndptr as it goes.
15665  */
15666 static struct mbuf *
15667 rack_fo_m_copym(struct tcp_rack *rack, int32_t *plen,
15668 		int32_t seglimit, int32_t segsize, struct mbuf **s_mb, int *s_soff)
15669 {
15670 	struct mbuf *m, *n;
15671 	int32_t soff;
15672 
15673 	soff = rack->r_ctl.fsb.off;
15674 	m = rack->r_ctl.fsb.m;
15675 	if (rack->r_ctl.fsb.o_m_len > m->m_len) {
15676 		/*
15677 		 * The mbuf had the front of it chopped off by an ack
15678 		 * we need to adjust the soff/off by that difference.
15679 		 */
15680 		uint32_t delta;
15681 
15682 		delta = rack->r_ctl.fsb.o_m_len - m->m_len;
15683 		soff -= delta;
15684 	} else if (rack->r_ctl.fsb.o_m_len < m->m_len) {
15685 		/*
15686 		 * The mbuf was expanded probably by
15687 		 * a m_compress. Just update o_m_len.
15688 		 */
15689 		rack->r_ctl.fsb.o_m_len = m->m_len;
15690 	}
15691 	KASSERT(soff >= 0, ("%s, negative off %d", __FUNCTION__, soff));
15692 	KASSERT(*plen >= 0, ("%s, negative len %d", __FUNCTION__, *plen));
15693 	KASSERT(soff < m->m_len, ("%s rack:%p len:%u m:%p m->m_len:%u < off?",
15694 				 __FUNCTION__,
15695 				 rack, *plen, m, m->m_len));
15696 	/* Save off the right location before we copy and advance */
15697 	*s_soff = soff;
15698 	*s_mb = rack->r_ctl.fsb.m;
15699 	n = rack_fo_base_copym(m, soff, plen,
15700 			       &rack->r_ctl.fsb,
15701 			       seglimit, segsize, rack->r_ctl.fsb.hw_tls);
15702 	return (n);
15703 }
15704 
15705 static int
15706 rack_fast_rsm_output(struct tcpcb *tp, struct tcp_rack *rack, struct rack_sendmap *rsm,
15707 		     uint64_t ts_val, uint32_t cts, uint32_t ms_cts, struct timeval *tv, int len, uint8_t doing_tlp)
15708 {
15709 	/*
15710 	 * Enter the fast retransmit path. We are given that a sched_pin is
15711 	 * in place (if accounting is compliled in) and the cycle count taken
15712 	 * at the entry is in the ts_val. The concept her is that the rsm
15713 	 * now holds the mbuf offsets and such so we can directly transmit
15714 	 * without a lot of overhead, the len field is already set for
15715 	 * us to prohibit us from sending too much (usually its 1MSS).
15716 	 */
15717 	struct ip *ip = NULL;
15718 	struct udphdr *udp = NULL;
15719 	struct tcphdr *th = NULL;
15720 	struct mbuf *m = NULL;
15721 	struct inpcb *inp;
15722 	uint8_t *cpto;
15723 	struct tcp_log_buffer *lgb;
15724 #ifdef TCP_ACCOUNTING
15725 	uint64_t crtsc;
15726 	int cnt_thru = 1;
15727 #endif
15728 	struct tcpopt to;
15729 	u_char opt[TCP_MAXOLEN];
15730 	uint32_t hdrlen, optlen;
15731 	int32_t slot, segsiz, max_val, tso = 0, error, flags, ulen = 0;
15732 	uint32_t us_cts;
15733 	uint32_t if_hw_tsomaxsegcount = 0, startseq;
15734 	uint32_t if_hw_tsomaxsegsize;
15735 
15736 #ifdef INET6
15737 	struct ip6_hdr *ip6 = NULL;
15738 
15739 	if (rack->r_is_v6) {
15740 		ip6 = (struct ip6_hdr *)rack->r_ctl.fsb.tcp_ip_hdr;
15741 		hdrlen = sizeof(struct ip6_hdr) + sizeof(struct tcphdr);
15742 	} else
15743 #endif				/* INET6 */
15744 	{
15745 		ip = (struct ip *)rack->r_ctl.fsb.tcp_ip_hdr;
15746 		hdrlen = sizeof(struct tcpiphdr);
15747 	}
15748 	if (tp->t_port && (V_tcp_udp_tunneling_port == 0)) {
15749 		goto failed;
15750 	}
15751 	if (doing_tlp) {
15752 		/* Its a TLP add the flag, it may already be there but be sure */
15753 		rsm->r_flags |= RACK_TLP;
15754 	} else {
15755 		/* If it was a TLP it is not not on this retransmit */
15756 		rsm->r_flags &= ~RACK_TLP;
15757 	}
15758 	startseq = rsm->r_start;
15759 	segsiz = min(ctf_fixed_maxseg(tp), rack->r_ctl.rc_pace_min_segs);
15760 	inp = rack->rc_inp;
15761 	to.to_flags = 0;
15762 	flags = tcp_outflags[tp->t_state];
15763 	if (flags & (TH_SYN|TH_RST)) {
15764 		goto failed;
15765 	}
15766 	if (rsm->r_flags & RACK_HAS_FIN) {
15767 		/* We can't send a FIN here */
15768 		goto failed;
15769 	}
15770 	if (flags & TH_FIN) {
15771 		/* We never send a FIN */
15772 		flags &= ~TH_FIN;
15773 	}
15774 	if (tp->t_flags & TF_RCVD_TSTMP) {
15775 		to.to_tsval = ms_cts + tp->ts_offset;
15776 		to.to_tsecr = tp->ts_recent;
15777 		to.to_flags = TOF_TS;
15778 	}
15779 	optlen = tcp_addoptions(&to, opt);
15780 	hdrlen += optlen;
15781 	udp = rack->r_ctl.fsb.udp;
15782 	if (udp)
15783 		hdrlen += sizeof(struct udphdr);
15784 	if (rack->r_ctl.rc_pace_max_segs)
15785 		max_val = rack->r_ctl.rc_pace_max_segs;
15786 	else if (rack->rc_user_set_max_segs)
15787 		max_val = rack->rc_user_set_max_segs * segsiz;
15788 	else
15789 		max_val = len;
15790 	if ((tp->t_flags & TF_TSO) &&
15791 	    V_tcp_do_tso &&
15792 	    (len > segsiz) &&
15793 	    (tp->t_port == 0))
15794 		tso = 1;
15795 #ifdef INET6
15796 	if (MHLEN < hdrlen + max_linkhdr)
15797 		m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR);
15798 	else
15799 #endif
15800 		m = m_gethdr(M_NOWAIT, MT_DATA);
15801 	if (m == NULL)
15802 		goto failed;
15803 	m->m_data += max_linkhdr;
15804 	m->m_len = hdrlen;
15805 	th = rack->r_ctl.fsb.th;
15806 	/* Establish the len to send */
15807 	if (len > max_val)
15808 		len = max_val;
15809 	if ((tso) && (len + optlen > tp->t_maxseg)) {
15810 		uint32_t if_hw_tsomax;
15811 		int32_t max_len;
15812 
15813 		/* extract TSO information */
15814 		if_hw_tsomax = tp->t_tsomax;
15815 		if_hw_tsomaxsegcount = tp->t_tsomaxsegcount;
15816 		if_hw_tsomaxsegsize = tp->t_tsomaxsegsize;
15817 		/*
15818 		 * Check if we should limit by maximum payload
15819 		 * length:
15820 		 */
15821 		if (if_hw_tsomax != 0) {
15822 			/* compute maximum TSO length */
15823 			max_len = (if_hw_tsomax - hdrlen -
15824 				   max_linkhdr);
15825 			if (max_len <= 0) {
15826 				goto failed;
15827 			} else if (len > max_len) {
15828 				len = max_len;
15829 			}
15830 		}
15831 		if (len <= segsiz) {
15832 			/*
15833 			 * In case there are too many small fragments don't
15834 			 * use TSO:
15835 			 */
15836 			tso = 0;
15837 		}
15838 	} else {
15839 		tso = 0;
15840 	}
15841 	if ((tso == 0) && (len > segsiz))
15842 		len = segsiz;
15843 	us_cts = tcp_get_usecs(tv);
15844 	if ((len == 0) ||
15845 	    (len <= MHLEN - hdrlen - max_linkhdr)) {
15846 		goto failed;
15847 	}
15848 	th->th_seq = htonl(rsm->r_start);
15849 	th->th_ack = htonl(tp->rcv_nxt);
15850 	/*
15851 	 * The PUSH bit should only be applied
15852 	 * if the full retransmission is made. If
15853 	 * we are sending less than this is the
15854 	 * left hand edge and should not have
15855 	 * the PUSH bit.
15856 	 */
15857 	if ((rsm->r_flags & RACK_HAD_PUSH) &&
15858 	    (len == (rsm->r_end - rsm->r_start)))
15859 		flags |= TH_PUSH;
15860 	th->th_flags = flags;
15861 	th->th_win = htons((u_short)(rack->r_ctl.fsb.recwin >> tp->rcv_scale));
15862 	if (th->th_win == 0) {
15863 		tp->t_sndzerowin++;
15864 		tp->t_flags |= TF_RXWIN0SENT;
15865 	} else
15866 		tp->t_flags &= ~TF_RXWIN0SENT;
15867 	if (rsm->r_flags & RACK_TLP) {
15868 		/*
15869 		 * TLP should not count in retran count, but
15870 		 * in its own bin
15871 		 */
15872 		counter_u64_add(rack_tlp_retran, 1);
15873 		counter_u64_add(rack_tlp_retran_bytes, len);
15874 	} else {
15875 		tp->t_sndrexmitpack++;
15876 		KMOD_TCPSTAT_INC(tcps_sndrexmitpack);
15877 		KMOD_TCPSTAT_ADD(tcps_sndrexmitbyte, len);
15878 	}
15879 #ifdef STATS
15880 	stats_voi_update_abs_u32(tp->t_stats, VOI_TCP_RETXPB,
15881 				 len);
15882 #endif
15883 	if (rsm->m == NULL)
15884 		goto failed;
15885 	if (rsm->orig_m_len != rsm->m->m_len) {
15886 		/* Fix up the orig_m_len and possibly the mbuf offset */
15887 		rack_adjust_orig_mlen(rsm);
15888 	}
15889 	m->m_next = rack_fo_base_copym(rsm->m, rsm->soff, &len, NULL, if_hw_tsomaxsegcount, if_hw_tsomaxsegsize, rsm->r_hw_tls);
15890 	if (len <= segsiz) {
15891 		/*
15892 		 * Must have ran out of mbufs for the copy
15893 		 * shorten it to no longer need tso. Lets
15894 		 * not put on sendalot since we are low on
15895 		 * mbufs.
15896 		 */
15897 		tso = 0;
15898 	}
15899 	if ((m->m_next == NULL) || (len <= 0)){
15900 		goto failed;
15901 	}
15902 	if (udp) {
15903 		if (rack->r_is_v6)
15904 			ulen = hdrlen + len - sizeof(struct ip6_hdr);
15905 		else
15906 			ulen = hdrlen + len - sizeof(struct ip);
15907 		udp->uh_ulen = htons(ulen);
15908 	}
15909 	m->m_pkthdr.rcvif = (struct ifnet *)0;
15910 	m->m_pkthdr.len = hdrlen + len;	/* in6_cksum() need this */
15911 #ifdef INET6
15912 	if (rack->r_is_v6) {
15913 		if (tp->t_port) {
15914 			m->m_pkthdr.csum_flags = CSUM_UDP_IPV6;
15915 			m->m_pkthdr.csum_data = offsetof(struct udphdr, uh_sum);
15916 			udp->uh_sum = in6_cksum_pseudo(ip6, ulen, IPPROTO_UDP, 0);
15917 			th->th_sum = htons(0);
15918 			UDPSTAT_INC(udps_opackets);
15919 		} else {
15920 			m->m_pkthdr.csum_flags = CSUM_TCP_IPV6;
15921 			m->m_pkthdr.csum_data = offsetof(struct tcphdr, th_sum);
15922 			th->th_sum = in6_cksum_pseudo(ip6,
15923 						      sizeof(struct tcphdr) + optlen + len, IPPROTO_TCP,
15924 						      0);
15925 		}
15926 	}
15927 #endif
15928 #if defined(INET6) && defined(INET)
15929 	else
15930 #endif
15931 #ifdef INET
15932 	{
15933 		if (tp->t_port) {
15934 			m->m_pkthdr.csum_flags = CSUM_UDP;
15935 			m->m_pkthdr.csum_data = offsetof(struct udphdr, uh_sum);
15936 			udp->uh_sum = in_pseudo(ip->ip_src.s_addr,
15937 						ip->ip_dst.s_addr, htons(ulen + IPPROTO_UDP));
15938 			th->th_sum = htons(0);
15939 			UDPSTAT_INC(udps_opackets);
15940 		} else {
15941 			m->m_pkthdr.csum_flags = CSUM_TCP;
15942 			m->m_pkthdr.csum_data = offsetof(struct tcphdr, th_sum);
15943 			th->th_sum = in_pseudo(ip->ip_src.s_addr,
15944 					       ip->ip_dst.s_addr, htons(sizeof(struct tcphdr) +
15945 									IPPROTO_TCP + len + optlen));
15946 		}
15947 		/* IP version must be set here for ipv4/ipv6 checking later */
15948 		KASSERT(ip->ip_v == IPVERSION,
15949 			("%s: IP version incorrect: %d", __func__, ip->ip_v));
15950 	}
15951 #endif
15952 	if (tso) {
15953 		KASSERT(len > tp->t_maxseg - optlen,
15954 			("%s: len <= tso_segsz tp:%p", __func__, tp));
15955 		m->m_pkthdr.csum_flags |= CSUM_TSO;
15956 		m->m_pkthdr.tso_segsz = tp->t_maxseg - optlen;
15957 	}
15958 #ifdef INET6
15959 	if (rack->r_is_v6) {
15960 		ip6->ip6_hlim = rack->r_ctl.fsb.hoplimit;
15961 		ip6->ip6_plen = htons(m->m_pkthdr.len - sizeof(*ip6));
15962 		if (V_path_mtu_discovery && tp->t_maxseg > V_tcp_minmss)
15963 			tp->t_flags2 |= TF2_PLPMTU_PMTUD;
15964 		else
15965 			tp->t_flags2 &= ~TF2_PLPMTU_PMTUD;
15966 	}
15967 #endif
15968 #if defined(INET) && defined(INET6)
15969 	else
15970 #endif
15971 #ifdef INET
15972 	{
15973 		ip->ip_len = htons(m->m_pkthdr.len);
15974 		ip->ip_ttl = rack->r_ctl.fsb.hoplimit;
15975 		if (V_path_mtu_discovery && tp->t_maxseg > V_tcp_minmss) {
15976 			tp->t_flags2 |= TF2_PLPMTU_PMTUD;
15977 			if (tp->t_port == 0 || len < V_tcp_minmss) {
15978 				ip->ip_off |= htons(IP_DF);
15979 			}
15980 		} else {
15981 			tp->t_flags2 &= ~TF2_PLPMTU_PMTUD;
15982 		}
15983 	}
15984 #endif
15985 	/* Time to copy in our header */
15986 	cpto = mtod(m, uint8_t *);
15987 	memcpy(cpto, rack->r_ctl.fsb.tcp_ip_hdr, rack->r_ctl.fsb.tcp_ip_hdr_len);
15988 	th = (struct tcphdr *)(cpto + ((uint8_t *)rack->r_ctl.fsb.th - rack->r_ctl.fsb.tcp_ip_hdr));
15989 	if (optlen) {
15990 		bcopy(opt, th + 1, optlen);
15991 		th->th_off = (sizeof(struct tcphdr) + optlen) >> 2;
15992 	} else {
15993 		th->th_off = sizeof(struct tcphdr) >> 2;
15994 	}
15995 	if (tp->t_logstate != TCP_LOG_STATE_OFF) {
15996 		union tcp_log_stackspecific log;
15997 
15998 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
15999 		log.u_bbr.inhpts = rack->rc_inp->inp_in_hpts;
16000 		log.u_bbr.ininput = rack->rc_inp->inp_in_input;
16001 		if (rack->rack_no_prr)
16002 			log.u_bbr.flex1 = 0;
16003 		else
16004 			log.u_bbr.flex1 = rack->r_ctl.rc_prr_sndcnt;
16005 		log.u_bbr.flex2 = rack->r_ctl.rc_pace_min_segs;
16006 		log.u_bbr.flex3 = rack->r_ctl.rc_pace_max_segs;
16007 		log.u_bbr.flex4 = max_val;
16008 		log.u_bbr.flex5 = 0;
16009 		/* Save off the early/late values */
16010 		log.u_bbr.flex6 = rack->r_ctl.rc_agg_early;
16011 		log.u_bbr.applimited = rack->r_ctl.rc_agg_delayed;
16012 		log.u_bbr.bw_inuse = rack_get_bw(rack);
16013 		if (doing_tlp == 0)
16014 			log.u_bbr.flex8 = 1;
16015 		else
16016 			log.u_bbr.flex8 = 2;
16017 		log.u_bbr.pacing_gain = rack_get_output_gain(rack, NULL);
16018 		log.u_bbr.flex7 = 55;
16019 		log.u_bbr.pkts_out = tp->t_maxseg;
16020 		log.u_bbr.timeStamp = cts;
16021 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
16022 		log.u_bbr.lt_epoch = rack->r_ctl.cwnd_to_use;
16023 		log.u_bbr.delivered = 0;
16024 		lgb = tcp_log_event_(tp, th, NULL, NULL, TCP_LOG_OUT, ERRNO_UNK,
16025 				     len, &log, false, NULL, NULL, 0, tv);
16026 	} else
16027 		lgb = NULL;
16028 #ifdef INET6
16029 	if (rack->r_is_v6) {
16030 		error = ip6_output(m, NULL,
16031 				   &inp->inp_route6,
16032 				   0, NULL, NULL, inp);
16033 	}
16034 #endif
16035 #if defined(INET) && defined(INET6)
16036 	else
16037 #endif
16038 #ifdef INET
16039 	{
16040 		error = ip_output(m, NULL,
16041 				  &inp->inp_route,
16042 				  0, 0, inp);
16043 	}
16044 #endif
16045 	m = NULL;
16046 	if (lgb) {
16047 		lgb->tlb_errno = error;
16048 		lgb = NULL;
16049 	}
16050 	if (error) {
16051 		goto failed;
16052 	}
16053 	rack_log_output(tp, &to, len, rsm->r_start, flags, error, rack_to_usec_ts(tv),
16054 			rsm, RACK_SENT_FP, rsm->m, rsm->soff, rsm->r_hw_tls);
16055 	if (doing_tlp && (rack->fast_rsm_hack == 0)) {
16056 		rack->rc_tlp_in_progress = 1;
16057 		rack->r_ctl.rc_tlp_cnt_out++;
16058 	}
16059 	if (error == 0) {
16060 		tcp_account_for_send(tp, len, 1, doing_tlp, rsm->r_hw_tls);
16061 		if (doing_tlp) {
16062 			rack->rc_last_sent_tlp_past_cumack = 0;
16063 			rack->rc_last_sent_tlp_seq_valid = 1;
16064 			rack->r_ctl.last_sent_tlp_seq = rsm->r_start;
16065 			rack->r_ctl.last_sent_tlp_len = rsm->r_end - rsm->r_start;
16066 		}
16067 	}
16068 	tp->t_flags &= ~(TF_ACKNOW | TF_DELACK);
16069 	rack->forced_ack = 0;	/* If we send something zap the FA flag */
16070 	if (IN_FASTRECOVERY(tp->t_flags) && rsm)
16071 		rack->r_ctl.retran_during_recovery += len;
16072 	{
16073 		int idx;
16074 
16075 		idx = (len / segsiz) + 3;
16076 		if (idx >= TCP_MSS_ACCT_ATIMER)
16077 			counter_u64_add(rack_out_size[(TCP_MSS_ACCT_ATIMER-1)], 1);
16078 		else
16079 			counter_u64_add(rack_out_size[idx], 1);
16080 	}
16081 	if (tp->t_rtttime == 0) {
16082 		tp->t_rtttime = ticks;
16083 		tp->t_rtseq = startseq;
16084 		KMOD_TCPSTAT_INC(tcps_segstimed);
16085 	}
16086 	counter_u64_add(rack_fto_rsm_send, 1);
16087 	if (error && (error == ENOBUFS)) {
16088 		slot = ((1 + rack->rc_enobuf) * HPTS_USEC_IN_MSEC);
16089 		if (rack->rc_enobuf < 0x7f)
16090 			rack->rc_enobuf++;
16091 		if (slot < (10 * HPTS_USEC_IN_MSEC))
16092 			slot = 10 * HPTS_USEC_IN_MSEC;
16093 	} else
16094 		slot = rack_get_pacing_delay(rack, tp, len, NULL, segsiz);
16095 	if ((slot == 0) ||
16096 	    (rack->rc_always_pace == 0) ||
16097 	    (rack->r_rr_config == 1)) {
16098 		/*
16099 		 * We have no pacing set or we
16100 		 * are using old-style rack or
16101 		 * we are overriden to use the old 1ms pacing.
16102 		 */
16103 		slot = rack->r_ctl.rc_min_to;
16104 	}
16105 	rack_start_hpts_timer(rack, tp, cts, slot, len, 0);
16106 	if (rack->r_must_retran) {
16107 		rack->r_ctl.rc_out_at_rto -= (rsm->r_end - rsm->r_start);
16108 		if (SEQ_GEQ(rsm->r_end, rack->r_ctl.rc_snd_max_at_rto)) {
16109 			/*
16110 			 * We have retransmitted all we need.
16111 			 */
16112 			rack->r_must_retran = 0;
16113 			rack->r_ctl.rc_out_at_rto = 0;
16114 		}
16115 	}
16116 #ifdef TCP_ACCOUNTING
16117 	crtsc = get_cyclecount();
16118 	if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
16119 		tp->tcp_cnt_counters[SND_OUT_DATA] += cnt_thru;
16120 	}
16121 	counter_u64_add(tcp_cnt_counters[SND_OUT_DATA], cnt_thru);
16122 	if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
16123 		tp->tcp_proc_time[SND_OUT_DATA] += (crtsc - ts_val);
16124 	}
16125 	counter_u64_add(tcp_proc_time[SND_OUT_DATA], (crtsc - ts_val));
16126 	if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
16127 		tp->tcp_cnt_counters[CNT_OF_MSS_OUT] += ((len + segsiz - 1) / segsiz);
16128 	}
16129 	counter_u64_add(tcp_cnt_counters[CNT_OF_MSS_OUT], ((len + segsiz - 1) / segsiz));
16130 	sched_unpin();
16131 #endif
16132 	return (0);
16133 failed:
16134 	if (m)
16135 		m_free(m);
16136 	return (-1);
16137 }
16138 
16139 static void
16140 rack_sndbuf_autoscale(struct tcp_rack *rack)
16141 {
16142 	/*
16143 	 * Automatic sizing of send socket buffer.  Often the send buffer
16144 	 * size is not optimally adjusted to the actual network conditions
16145 	 * at hand (delay bandwidth product).  Setting the buffer size too
16146 	 * small limits throughput on links with high bandwidth and high
16147 	 * delay (eg. trans-continental/oceanic links).  Setting the
16148 	 * buffer size too big consumes too much real kernel memory,
16149 	 * especially with many connections on busy servers.
16150 	 *
16151 	 * The criteria to step up the send buffer one notch are:
16152 	 *  1. receive window of remote host is larger than send buffer
16153 	 *     (with a fudge factor of 5/4th);
16154 	 *  2. send buffer is filled to 7/8th with data (so we actually
16155 	 *     have data to make use of it);
16156 	 *  3. send buffer fill has not hit maximal automatic size;
16157 	 *  4. our send window (slow start and cogestion controlled) is
16158 	 *     larger than sent but unacknowledged data in send buffer.
16159 	 *
16160 	 * Note that the rack version moves things much faster since
16161 	 * we want to avoid hitting cache lines in the rack_fast_output()
16162 	 * path so this is called much less often and thus moves
16163 	 * the SB forward by a percentage.
16164 	 */
16165 	struct socket *so;
16166 	struct tcpcb *tp;
16167 	uint32_t sendwin, scaleup;
16168 
16169 	tp = rack->rc_tp;
16170 	so = rack->rc_inp->inp_socket;
16171 	sendwin = min(rack->r_ctl.cwnd_to_use, tp->snd_wnd);
16172 	if (V_tcp_do_autosndbuf && so->so_snd.sb_flags & SB_AUTOSIZE) {
16173 		if ((tp->snd_wnd / 4 * 5) >= so->so_snd.sb_hiwat &&
16174 		    sbused(&so->so_snd) >=
16175 		    (so->so_snd.sb_hiwat / 8 * 7) &&
16176 		    sbused(&so->so_snd) < V_tcp_autosndbuf_max &&
16177 		    sendwin >= (sbused(&so->so_snd) -
16178 		    (tp->snd_nxt - tp->snd_una))) {
16179 			if (rack_autosndbuf_inc)
16180 				scaleup = (rack_autosndbuf_inc * so->so_snd.sb_hiwat) / 100;
16181 			else
16182 				scaleup = V_tcp_autosndbuf_inc;
16183 			if (scaleup < V_tcp_autosndbuf_inc)
16184 				scaleup = V_tcp_autosndbuf_inc;
16185 			scaleup += so->so_snd.sb_hiwat;
16186 			if (scaleup > V_tcp_autosndbuf_max)
16187 				scaleup = V_tcp_autosndbuf_max;
16188 			if (!sbreserve_locked(&so->so_snd, scaleup, so, curthread))
16189 				so->so_snd.sb_flags &= ~SB_AUTOSIZE;
16190 		}
16191 	}
16192 }
16193 
16194 static int
16195 rack_fast_output(struct tcpcb *tp, struct tcp_rack *rack, uint64_t ts_val,
16196 		 uint32_t cts, uint32_t ms_cts, struct timeval *tv, long tot_len, int *send_err)
16197 {
16198 	/*
16199 	 * Enter to do fast output. We are given that the sched_pin is
16200 	 * in place (if accounting is compiled in) and the cycle count taken
16201 	 * at entry is in place in ts_val. The idea here is that
16202 	 * we know how many more bytes needs to be sent (presumably either
16203 	 * during pacing or to fill the cwnd and that was greater than
16204 	 * the max-burst). We have how much to send and all the info we
16205 	 * need to just send.
16206 	 */
16207 	struct ip *ip = NULL;
16208 	struct udphdr *udp = NULL;
16209 	struct tcphdr *th = NULL;
16210 	struct mbuf *m, *s_mb;
16211 	struct inpcb *inp;
16212 	uint8_t *cpto;
16213 	struct tcp_log_buffer *lgb;
16214 #ifdef TCP_ACCOUNTING
16215 	uint64_t crtsc;
16216 #endif
16217 	struct tcpopt to;
16218 	u_char opt[TCP_MAXOLEN];
16219 	uint32_t hdrlen, optlen;
16220 	int cnt_thru = 1;
16221 	int32_t slot, segsiz, len, max_val, tso = 0, sb_offset, error, flags, ulen = 0;
16222 	uint32_t us_cts, s_soff;
16223 	uint32_t if_hw_tsomaxsegcount = 0, startseq;
16224 	uint32_t if_hw_tsomaxsegsize;
16225 	uint16_t add_flag = RACK_SENT_FP;
16226 #ifdef INET6
16227 	struct ip6_hdr *ip6 = NULL;
16228 
16229 	if (rack->r_is_v6) {
16230 		ip6 = (struct ip6_hdr *)rack->r_ctl.fsb.tcp_ip_hdr;
16231 		hdrlen = sizeof(struct ip6_hdr) + sizeof(struct tcphdr);
16232 	} else
16233 #endif				/* INET6 */
16234 	{
16235 		ip = (struct ip *)rack->r_ctl.fsb.tcp_ip_hdr;
16236 		hdrlen = sizeof(struct tcpiphdr);
16237 	}
16238 	if (tp->t_port && (V_tcp_udp_tunneling_port == 0)) {
16239 		m = NULL;
16240 		goto failed;
16241 	}
16242 	startseq = tp->snd_max;
16243 	segsiz = min(ctf_fixed_maxseg(tp), rack->r_ctl.rc_pace_min_segs);
16244 	inp = rack->rc_inp;
16245 	len = rack->r_ctl.fsb.left_to_send;
16246 	to.to_flags = 0;
16247 	flags = rack->r_ctl.fsb.tcp_flags;
16248 	if (tp->t_flags & TF_RCVD_TSTMP) {
16249 		to.to_tsval = ms_cts + tp->ts_offset;
16250 		to.to_tsecr = tp->ts_recent;
16251 		to.to_flags = TOF_TS;
16252 	}
16253 	optlen = tcp_addoptions(&to, opt);
16254 	hdrlen += optlen;
16255 	udp = rack->r_ctl.fsb.udp;
16256 	if (udp)
16257 		hdrlen += sizeof(struct udphdr);
16258 	if (rack->r_ctl.rc_pace_max_segs)
16259 		max_val = rack->r_ctl.rc_pace_max_segs;
16260 	else if (rack->rc_user_set_max_segs)
16261 		max_val = rack->rc_user_set_max_segs * segsiz;
16262 	else
16263 		max_val = len;
16264 	if ((tp->t_flags & TF_TSO) &&
16265 	    V_tcp_do_tso &&
16266 	    (len > segsiz) &&
16267 	    (tp->t_port == 0))
16268 		tso = 1;
16269 again:
16270 #ifdef INET6
16271 	if (MHLEN < hdrlen + max_linkhdr)
16272 		m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR);
16273 	else
16274 #endif
16275 		m = m_gethdr(M_NOWAIT, MT_DATA);
16276 	if (m == NULL)
16277 		goto failed;
16278 	m->m_data += max_linkhdr;
16279 	m->m_len = hdrlen;
16280 	th = rack->r_ctl.fsb.th;
16281 	/* Establish the len to send */
16282 	if (len > max_val)
16283 		len = max_val;
16284 	if ((tso) && (len + optlen > tp->t_maxseg)) {
16285 		uint32_t if_hw_tsomax;
16286 		int32_t max_len;
16287 
16288 		/* extract TSO information */
16289 		if_hw_tsomax = tp->t_tsomax;
16290 		if_hw_tsomaxsegcount = tp->t_tsomaxsegcount;
16291 		if_hw_tsomaxsegsize = tp->t_tsomaxsegsize;
16292 		/*
16293 		 * Check if we should limit by maximum payload
16294 		 * length:
16295 		 */
16296 		if (if_hw_tsomax != 0) {
16297 			/* compute maximum TSO length */
16298 			max_len = (if_hw_tsomax - hdrlen -
16299 				   max_linkhdr);
16300 			if (max_len <= 0) {
16301 				goto failed;
16302 			} else if (len > max_len) {
16303 				len = max_len;
16304 			}
16305 		}
16306 		if (len <= segsiz) {
16307 			/*
16308 			 * In case there are too many small fragments don't
16309 			 * use TSO:
16310 			 */
16311 			tso = 0;
16312 		}
16313 	} else {
16314 		tso = 0;
16315 	}
16316 	if ((tso == 0) && (len > segsiz))
16317 		len = segsiz;
16318 	us_cts = tcp_get_usecs(tv);
16319 	if ((len == 0) ||
16320 	    (len <= MHLEN - hdrlen - max_linkhdr)) {
16321 		goto failed;
16322 	}
16323 	sb_offset = tp->snd_max - tp->snd_una;
16324 	th->th_seq = htonl(tp->snd_max);
16325 	th->th_ack = htonl(tp->rcv_nxt);
16326 	th->th_flags = flags;
16327 	th->th_win = htons((u_short)(rack->r_ctl.fsb.recwin >> tp->rcv_scale));
16328 	if (th->th_win == 0) {
16329 		tp->t_sndzerowin++;
16330 		tp->t_flags |= TF_RXWIN0SENT;
16331 	} else
16332 		tp->t_flags &= ~TF_RXWIN0SENT;
16333 	tp->snd_up = tp->snd_una;	/* drag it along, its deprecated */
16334 	KMOD_TCPSTAT_INC(tcps_sndpack);
16335 	KMOD_TCPSTAT_ADD(tcps_sndbyte, len);
16336 #ifdef STATS
16337 	stats_voi_update_abs_u64(tp->t_stats, VOI_TCP_TXPB,
16338 				 len);
16339 #endif
16340 	if (rack->r_ctl.fsb.m == NULL)
16341 		goto failed;
16342 
16343 	/* s_mb and s_soff are saved for rack_log_output */
16344 	m->m_next = rack_fo_m_copym(rack, &len, if_hw_tsomaxsegcount, if_hw_tsomaxsegsize,
16345 				    &s_mb, &s_soff);
16346 	if (len <= segsiz) {
16347 		/*
16348 		 * Must have ran out of mbufs for the copy
16349 		 * shorten it to no longer need tso. Lets
16350 		 * not put on sendalot since we are low on
16351 		 * mbufs.
16352 		 */
16353 		tso = 0;
16354 	}
16355 	if (rack->r_ctl.fsb.rfo_apply_push &&
16356 	    (len == rack->r_ctl.fsb.left_to_send)) {
16357 		th->th_flags |= TH_PUSH;
16358 		add_flag |= RACK_HAD_PUSH;
16359 	}
16360 	if ((m->m_next == NULL) || (len <= 0)){
16361 		goto failed;
16362 	}
16363 	if (udp) {
16364 		if (rack->r_is_v6)
16365 			ulen = hdrlen + len - sizeof(struct ip6_hdr);
16366 		else
16367 			ulen = hdrlen + len - sizeof(struct ip);
16368 		udp->uh_ulen = htons(ulen);
16369 	}
16370 	m->m_pkthdr.rcvif = (struct ifnet *)0;
16371 	if (tp->t_state == TCPS_ESTABLISHED &&
16372 	    (tp->t_flags2 & TF2_ECN_PERMIT)) {
16373 		/*
16374 		 * If the peer has ECN, mark data packets with ECN capable
16375 		 * transmission (ECT). Ignore pure ack packets,
16376 		 * retransmissions.
16377 		 */
16378 		if (len > 0 && SEQ_GEQ(tp->snd_nxt, tp->snd_max)) {
16379 #ifdef INET6
16380 			if (rack->r_is_v6)
16381 				ip6->ip6_flow |= htonl(IPTOS_ECN_ECT0 << 20);
16382 			else
16383 #endif
16384 				ip->ip_tos |= IPTOS_ECN_ECT0;
16385 			KMOD_TCPSTAT_INC(tcps_ecn_ect0);
16386 			/*
16387 			 * Reply with proper ECN notifications.
16388 			 * Only set CWR on new data segments.
16389 			 */
16390 			if (tp->t_flags2 & TF2_ECN_SND_CWR) {
16391 				flags |= TH_CWR;
16392 				tp->t_flags2 &= ~TF2_ECN_SND_CWR;
16393 			}
16394 		}
16395 		if (tp->t_flags2 & TF2_ECN_SND_ECE)
16396 			flags |= TH_ECE;
16397 	}
16398 	m->m_pkthdr.len = hdrlen + len;	/* in6_cksum() need this */
16399 #ifdef INET6
16400 	if (rack->r_is_v6) {
16401 		if (tp->t_port) {
16402 			m->m_pkthdr.csum_flags = CSUM_UDP_IPV6;
16403 			m->m_pkthdr.csum_data = offsetof(struct udphdr, uh_sum);
16404 			udp->uh_sum = in6_cksum_pseudo(ip6, ulen, IPPROTO_UDP, 0);
16405 			th->th_sum = htons(0);
16406 			UDPSTAT_INC(udps_opackets);
16407 		} else {
16408 			m->m_pkthdr.csum_flags = CSUM_TCP_IPV6;
16409 			m->m_pkthdr.csum_data = offsetof(struct tcphdr, th_sum);
16410 			th->th_sum = in6_cksum_pseudo(ip6,
16411 						      sizeof(struct tcphdr) + optlen + len, IPPROTO_TCP,
16412 						      0);
16413 		}
16414 	}
16415 #endif
16416 #if defined(INET6) && defined(INET)
16417 	else
16418 #endif
16419 #ifdef INET
16420 	{
16421 		if (tp->t_port) {
16422 			m->m_pkthdr.csum_flags = CSUM_UDP;
16423 			m->m_pkthdr.csum_data = offsetof(struct udphdr, uh_sum);
16424 			udp->uh_sum = in_pseudo(ip->ip_src.s_addr,
16425 						ip->ip_dst.s_addr, htons(ulen + IPPROTO_UDP));
16426 			th->th_sum = htons(0);
16427 			UDPSTAT_INC(udps_opackets);
16428 		} else {
16429 			m->m_pkthdr.csum_flags = CSUM_TCP;
16430 			m->m_pkthdr.csum_data = offsetof(struct tcphdr, th_sum);
16431 			th->th_sum = in_pseudo(ip->ip_src.s_addr,
16432 					       ip->ip_dst.s_addr, htons(sizeof(struct tcphdr) +
16433 									IPPROTO_TCP + len + optlen));
16434 		}
16435 		/* IP version must be set here for ipv4/ipv6 checking later */
16436 		KASSERT(ip->ip_v == IPVERSION,
16437 			("%s: IP version incorrect: %d", __func__, ip->ip_v));
16438 	}
16439 #endif
16440 	if (tso) {
16441 		KASSERT(len > tp->t_maxseg - optlen,
16442 			("%s: len <= tso_segsz tp:%p", __func__, tp));
16443 		m->m_pkthdr.csum_flags |= CSUM_TSO;
16444 		m->m_pkthdr.tso_segsz = tp->t_maxseg - optlen;
16445 	}
16446 #ifdef INET6
16447 	if (rack->r_is_v6) {
16448 		ip6->ip6_hlim = rack->r_ctl.fsb.hoplimit;
16449 		ip6->ip6_plen = htons(m->m_pkthdr.len - sizeof(*ip6));
16450 		if (V_path_mtu_discovery && tp->t_maxseg > V_tcp_minmss)
16451 			tp->t_flags2 |= TF2_PLPMTU_PMTUD;
16452 		else
16453 			tp->t_flags2 &= ~TF2_PLPMTU_PMTUD;
16454 	}
16455 #endif
16456 #if defined(INET) && defined(INET6)
16457 	else
16458 #endif
16459 #ifdef INET
16460 	{
16461 		ip->ip_len = htons(m->m_pkthdr.len);
16462 		ip->ip_ttl = rack->r_ctl.fsb.hoplimit;
16463 		if (V_path_mtu_discovery && tp->t_maxseg > V_tcp_minmss) {
16464 			tp->t_flags2 |= TF2_PLPMTU_PMTUD;
16465 			if (tp->t_port == 0 || len < V_tcp_minmss) {
16466 				ip->ip_off |= htons(IP_DF);
16467 			}
16468 		} else {
16469 			tp->t_flags2 &= ~TF2_PLPMTU_PMTUD;
16470 		}
16471 	}
16472 #endif
16473 	/* Time to copy in our header */
16474 	cpto = mtod(m, uint8_t *);
16475 	memcpy(cpto, rack->r_ctl.fsb.tcp_ip_hdr, rack->r_ctl.fsb.tcp_ip_hdr_len);
16476 	th = (struct tcphdr *)(cpto + ((uint8_t *)rack->r_ctl.fsb.th - rack->r_ctl.fsb.tcp_ip_hdr));
16477 	if (optlen) {
16478 		bcopy(opt, th + 1, optlen);
16479 		th->th_off = (sizeof(struct tcphdr) + optlen) >> 2;
16480 	} else {
16481 		th->th_off = sizeof(struct tcphdr) >> 2;
16482 	}
16483 	if (tp->t_logstate != TCP_LOG_STATE_OFF) {
16484 		union tcp_log_stackspecific log;
16485 
16486 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
16487 		log.u_bbr.inhpts = rack->rc_inp->inp_in_hpts;
16488 		log.u_bbr.ininput = rack->rc_inp->inp_in_input;
16489 		if (rack->rack_no_prr)
16490 			log.u_bbr.flex1 = 0;
16491 		else
16492 			log.u_bbr.flex1 = rack->r_ctl.rc_prr_sndcnt;
16493 		log.u_bbr.flex2 = rack->r_ctl.rc_pace_min_segs;
16494 		log.u_bbr.flex3 = rack->r_ctl.rc_pace_max_segs;
16495 		log.u_bbr.flex4 = max_val;
16496 		log.u_bbr.flex5 = 0;
16497 		/* Save off the early/late values */
16498 		log.u_bbr.flex6 = rack->r_ctl.rc_agg_early;
16499 		log.u_bbr.applimited = rack->r_ctl.rc_agg_delayed;
16500 		log.u_bbr.bw_inuse = rack_get_bw(rack);
16501 		log.u_bbr.flex8 = 0;
16502 		log.u_bbr.pacing_gain = rack_get_output_gain(rack, NULL);
16503 		log.u_bbr.flex7 = 44;
16504 		log.u_bbr.pkts_out = tp->t_maxseg;
16505 		log.u_bbr.timeStamp = cts;
16506 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
16507 		log.u_bbr.lt_epoch = rack->r_ctl.cwnd_to_use;
16508 		log.u_bbr.delivered = 0;
16509 		lgb = tcp_log_event_(tp, th, NULL, NULL, TCP_LOG_OUT, ERRNO_UNK,
16510 				     len, &log, false, NULL, NULL, 0, tv);
16511 	} else
16512 		lgb = NULL;
16513 #ifdef INET6
16514 	if (rack->r_is_v6) {
16515 		error = ip6_output(m, NULL,
16516 				   &inp->inp_route6,
16517 				   0, NULL, NULL, inp);
16518 	}
16519 #endif
16520 #if defined(INET) && defined(INET6)
16521 	else
16522 #endif
16523 #ifdef INET
16524 	{
16525 		error = ip_output(m, NULL,
16526 				  &inp->inp_route,
16527 				  0, 0, inp);
16528 	}
16529 #endif
16530 	if (lgb) {
16531 		lgb->tlb_errno = error;
16532 		lgb = NULL;
16533 	}
16534 	if (error) {
16535 		*send_err = error;
16536 		m = NULL;
16537 		goto failed;
16538 	}
16539 	rack_log_output(tp, &to, len, tp->snd_max, flags, error, rack_to_usec_ts(tv),
16540 			NULL, add_flag, s_mb, s_soff, rack->r_ctl.fsb.hw_tls);
16541 	m = NULL;
16542 	if (tp->snd_una == tp->snd_max) {
16543 		rack->r_ctl.rc_tlp_rxt_last_time = cts;
16544 		rack_log_progress_event(rack, tp, ticks, PROGRESS_START, __LINE__);
16545 		tp->t_acktime = ticks;
16546 	}
16547 	if (error == 0)
16548 		tcp_account_for_send(tp, len, 0, 0, rack->r_ctl.fsb.hw_tls);
16549 
16550 	rack->forced_ack = 0;	/* If we send something zap the FA flag */
16551 	tot_len += len;
16552 	if ((tp->t_flags & TF_GPUTINPROG) == 0)
16553 		rack_start_gp_measurement(tp, rack, tp->snd_max, sb_offset);
16554 	tp->snd_max += len;
16555 	tp->snd_nxt = tp->snd_max;
16556 	{
16557 		int idx;
16558 
16559 		idx = (len / segsiz) + 3;
16560 		if (idx >= TCP_MSS_ACCT_ATIMER)
16561 			counter_u64_add(rack_out_size[(TCP_MSS_ACCT_ATIMER-1)], 1);
16562 		else
16563 			counter_u64_add(rack_out_size[idx], 1);
16564 	}
16565 	if (len <= rack->r_ctl.fsb.left_to_send)
16566 		rack->r_ctl.fsb.left_to_send -= len;
16567 	else
16568 		rack->r_ctl.fsb.left_to_send = 0;
16569 	if (rack->r_ctl.fsb.left_to_send < segsiz) {
16570 		rack->r_fast_output = 0;
16571 		rack->r_ctl.fsb.left_to_send = 0;
16572 		/* At the end of fast_output scale up the sb */
16573 		SOCKBUF_LOCK(&rack->rc_inp->inp_socket->so_snd);
16574 		rack_sndbuf_autoscale(rack);
16575 		SOCKBUF_UNLOCK(&rack->rc_inp->inp_socket->so_snd);
16576 	}
16577 	if (tp->t_rtttime == 0) {
16578 		tp->t_rtttime = ticks;
16579 		tp->t_rtseq = startseq;
16580 		KMOD_TCPSTAT_INC(tcps_segstimed);
16581 	}
16582 	if ((rack->r_ctl.fsb.left_to_send >= segsiz) &&
16583 	    (max_val > len) &&
16584 	    (tso == 0)) {
16585 		max_val -= len;
16586 		len = segsiz;
16587 		th = rack->r_ctl.fsb.th;
16588 		cnt_thru++;
16589 		goto again;
16590 	}
16591 	tp->t_flags &= ~(TF_ACKNOW | TF_DELACK);
16592 	counter_u64_add(rack_fto_send, 1);
16593 	slot = rack_get_pacing_delay(rack, tp, tot_len, NULL, segsiz);
16594 	rack_start_hpts_timer(rack, tp, cts, slot, tot_len, 0);
16595 #ifdef TCP_ACCOUNTING
16596 	crtsc = get_cyclecount();
16597 	if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
16598 		tp->tcp_cnt_counters[SND_OUT_DATA] += cnt_thru;
16599 	}
16600 	counter_u64_add(tcp_cnt_counters[SND_OUT_DATA], cnt_thru);
16601 	if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
16602 		tp->tcp_proc_time[SND_OUT_DATA] += (crtsc - ts_val);
16603 	}
16604 	counter_u64_add(tcp_proc_time[SND_OUT_DATA], (crtsc - ts_val));
16605 	if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
16606 		tp->tcp_cnt_counters[CNT_OF_MSS_OUT] += ((tot_len + segsiz - 1) / segsiz);
16607 	}
16608 	counter_u64_add(tcp_cnt_counters[CNT_OF_MSS_OUT], ((tot_len + segsiz - 1) / segsiz));
16609 	sched_unpin();
16610 #endif
16611 	return (0);
16612 failed:
16613 	if (m)
16614 		m_free(m);
16615 	rack->r_fast_output = 0;
16616 	return (-1);
16617 }
16618 
16619 static int
16620 rack_output(struct tcpcb *tp)
16621 {
16622 	struct socket *so;
16623 	uint32_t recwin;
16624 	uint32_t sb_offset, s_moff = 0;
16625 	int32_t len, flags, error = 0;
16626 	struct mbuf *m, *s_mb = NULL;
16627 	struct mbuf *mb;
16628 	uint32_t if_hw_tsomaxsegcount = 0;
16629 	uint32_t if_hw_tsomaxsegsize;
16630 	int32_t segsiz, minseg;
16631 	long tot_len_this_send = 0;
16632 #ifdef INET
16633 	struct ip *ip = NULL;
16634 #endif
16635 #ifdef TCPDEBUG
16636 	struct ipovly *ipov = NULL;
16637 #endif
16638 	struct udphdr *udp = NULL;
16639 	struct tcp_rack *rack;
16640 	struct tcphdr *th;
16641 	uint8_t pass = 0;
16642 	uint8_t mark = 0;
16643 	uint8_t wanted_cookie = 0;
16644 	u_char opt[TCP_MAXOLEN];
16645 	unsigned ipoptlen, optlen, hdrlen, ulen=0;
16646 	uint32_t rack_seq;
16647 
16648 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
16649 	unsigned ipsec_optlen = 0;
16650 
16651 #endif
16652 	int32_t idle, sendalot;
16653 	int32_t sub_from_prr = 0;
16654 	volatile int32_t sack_rxmit;
16655 	struct rack_sendmap *rsm = NULL;
16656 	int32_t tso, mtu;
16657 	struct tcpopt to;
16658 	int32_t slot = 0;
16659 	int32_t sup_rack = 0;
16660 	uint32_t cts, ms_cts, delayed, early;
16661 	uint16_t add_flag = RACK_SENT_SP;
16662 	/* The doing_tlp flag will be set by the actual rack_timeout_tlp() */
16663 	uint8_t hpts_calling,  doing_tlp = 0;
16664 	uint32_t cwnd_to_use, pace_max_seg;
16665 	int32_t do_a_prefetch = 0;
16666 	int32_t prefetch_rsm = 0;
16667 	int32_t orig_len = 0;
16668 	struct timeval tv;
16669 	int32_t prefetch_so_done = 0;
16670 	struct tcp_log_buffer *lgb;
16671 	struct inpcb *inp;
16672 	struct sockbuf *sb;
16673 	uint64_t ts_val = 0;
16674 #ifdef TCP_ACCOUNTING
16675 	uint64_t crtsc;
16676 #endif
16677 #ifdef INET6
16678 	struct ip6_hdr *ip6 = NULL;
16679 	int32_t isipv6;
16680 #endif
16681 	uint8_t filled_all = 0;
16682 	bool hw_tls = false;
16683 
16684 	/* setup and take the cache hits here */
16685 	rack = (struct tcp_rack *)tp->t_fb_ptr;
16686 #ifdef TCP_ACCOUNTING
16687 	sched_pin();
16688 	ts_val = get_cyclecount();
16689 #endif
16690 	hpts_calling = rack->rc_inp->inp_hpts_calls;
16691 	NET_EPOCH_ASSERT();
16692 	INP_WLOCK_ASSERT(rack->rc_inp);
16693 #ifdef TCP_OFFLOAD
16694 	if (tp->t_flags & TF_TOE) {
16695 #ifdef TCP_ACCOUNTING
16696 		sched_unpin();
16697 #endif
16698 		return (tcp_offload_output(tp));
16699 	}
16700 #endif
16701 	/*
16702 	 * For TFO connections in SYN_RECEIVED, only allow the initial
16703 	 * SYN|ACK and those sent by the retransmit timer.
16704 	 */
16705 	if (IS_FASTOPEN(tp->t_flags) &&
16706 	    (tp->t_state == TCPS_SYN_RECEIVED) &&
16707 	    SEQ_GT(tp->snd_max, tp->snd_una) &&    /* initial SYN|ACK sent */
16708 	    (rack->r_ctl.rc_resend == NULL)) {         /* not a retransmit */
16709 #ifdef TCP_ACCOUNTING
16710 		sched_unpin();
16711 #endif
16712 		return (0);
16713 	}
16714 #ifdef INET6
16715 	if (rack->r_state) {
16716 		/* Use the cache line loaded if possible */
16717 		isipv6 = rack->r_is_v6;
16718 	} else {
16719 		isipv6 = (rack->rc_inp->inp_vflag & INP_IPV6) != 0;
16720 	}
16721 #endif
16722 	early = 0;
16723 	cts = tcp_get_usecs(&tv);
16724 	ms_cts = tcp_tv_to_mssectick(&tv);
16725 	if (((rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT) == 0) &&
16726 	    rack->rc_inp->inp_in_hpts) {
16727 		/*
16728 		 * We are on the hpts for some timer but not hptsi output.
16729 		 * Remove from the hpts unconditionally.
16730 		 */
16731 		rack_timer_cancel(tp, rack, cts, __LINE__);
16732 	}
16733 	/* Are we pacing and late? */
16734 	if ((rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT) &&
16735 	    TSTMP_GEQ(cts, rack->r_ctl.rc_last_output_to)) {
16736 		/* We are delayed */
16737 		delayed = cts - rack->r_ctl.rc_last_output_to;
16738 	} else {
16739 		delayed = 0;
16740 	}
16741 	/* Do the timers, which may override the pacer */
16742 	if (rack->r_ctl.rc_hpts_flags & PACE_TMR_MASK) {
16743 		if (rack_process_timers(tp, rack, cts, hpts_calling, &doing_tlp)) {
16744 			counter_u64_add(rack_out_size[TCP_MSS_ACCT_ATIMER], 1);
16745 #ifdef TCP_ACCOUNTING
16746 			sched_unpin();
16747 #endif
16748 			return (0);
16749 		}
16750 	}
16751 	if (rack->rc_in_persist) {
16752 		if (rack->rc_inp->inp_in_hpts == 0) {
16753 			/* Timer is not running */
16754 			rack_start_hpts_timer(rack, tp, cts, 0, 0, 0);
16755 		}
16756 #ifdef TCP_ACCOUNTING
16757 		sched_unpin();
16758 #endif
16759 		return (0);
16760 	}
16761 	if ((rack->r_timer_override) ||
16762 	    (rack->rc_ack_can_sendout_data) ||
16763 	    (delayed) ||
16764 	    (tp->t_state < TCPS_ESTABLISHED)) {
16765 		rack->rc_ack_can_sendout_data = 0;
16766 		if (rack->rc_inp->inp_in_hpts)
16767 			tcp_hpts_remove(rack->rc_inp, HPTS_REMOVE_OUTPUT);
16768 	} else if (rack->rc_inp->inp_in_hpts) {
16769 		/*
16770 		 * On the hpts you can't pass even if ACKNOW is on, we will
16771 		 * when the hpts fires.
16772 		 */
16773 #ifdef TCP_ACCOUNTING
16774 		crtsc = get_cyclecount();
16775 		if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
16776 			tp->tcp_proc_time[SND_BLOCKED] += (crtsc - ts_val);
16777 		}
16778 		counter_u64_add(tcp_proc_time[SND_BLOCKED], (crtsc - ts_val));
16779 		if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
16780 			tp->tcp_cnt_counters[SND_BLOCKED]++;
16781 		}
16782 		counter_u64_add(tcp_cnt_counters[SND_BLOCKED], 1);
16783 		sched_unpin();
16784 #endif
16785 		counter_u64_add(rack_out_size[TCP_MSS_ACCT_INPACE], 1);
16786 		return (0);
16787 	}
16788 	rack->rc_inp->inp_hpts_calls = 0;
16789 	/* Finish out both pacing early and late accounting */
16790 	if ((rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT) &&
16791 	    TSTMP_GT(rack->r_ctl.rc_last_output_to, cts)) {
16792 		early = rack->r_ctl.rc_last_output_to - cts;
16793 	} else
16794 		early = 0;
16795 	if (delayed) {
16796 		rack->r_ctl.rc_agg_delayed += delayed;
16797 		rack->r_late = 1;
16798 	} else if (early) {
16799 		rack->r_ctl.rc_agg_early += early;
16800 		rack->r_early = 1;
16801 	}
16802 	/* Now that early/late accounting is done turn off the flag */
16803 	rack->r_ctl.rc_hpts_flags &= ~PACE_PKT_OUTPUT;
16804 	rack->r_wanted_output = 0;
16805 	rack->r_timer_override = 0;
16806 	if ((tp->t_state != rack->r_state) &&
16807 	    TCPS_HAVEESTABLISHED(tp->t_state)) {
16808 		rack_set_state(tp, rack);
16809 	}
16810 	if ((rack->r_fast_output) &&
16811 	    (doing_tlp == 0) &&
16812 	    (tp->rcv_numsacks == 0)) {
16813 		int ret;
16814 
16815 		error = 0;
16816 		ret = rack_fast_output(tp, rack, ts_val, cts, ms_cts, &tv, tot_len_this_send, &error);
16817 		if (ret >= 0)
16818 			return(ret);
16819 		else if (error) {
16820 			inp = rack->rc_inp;
16821 			so = inp->inp_socket;
16822 			sb = &so->so_snd;
16823 			goto nomore;
16824 		}
16825 	}
16826 	inp = rack->rc_inp;
16827 	/*
16828 	 * For TFO connections in SYN_SENT or SYN_RECEIVED,
16829 	 * only allow the initial SYN or SYN|ACK and those sent
16830 	 * by the retransmit timer.
16831 	 */
16832 	if (IS_FASTOPEN(tp->t_flags) &&
16833 	    ((tp->t_state == TCPS_SYN_RECEIVED) ||
16834 	     (tp->t_state == TCPS_SYN_SENT)) &&
16835 	    SEQ_GT(tp->snd_max, tp->snd_una) && /* initial SYN or SYN|ACK sent */
16836 	    (tp->t_rxtshift == 0)) {              /* not a retransmit */
16837 		cwnd_to_use = rack->r_ctl.cwnd_to_use = tp->snd_cwnd;
16838 		so = inp->inp_socket;
16839 		sb = &so->so_snd;
16840 		goto just_return_nolock;
16841 	}
16842 	/*
16843 	 * Determine length of data that should be transmitted, and flags
16844 	 * that will be used. If there is some data or critical controls
16845 	 * (SYN, RST) to send, then transmit; otherwise, investigate
16846 	 * further.
16847 	 */
16848 	idle = (tp->t_flags & TF_LASTIDLE) || (tp->snd_max == tp->snd_una);
16849 	if (tp->t_idle_reduce) {
16850 		if (idle && ((ticks - tp->t_rcvtime) >= tp->t_rxtcur))
16851 			rack_cc_after_idle(rack, tp);
16852 	}
16853 	tp->t_flags &= ~TF_LASTIDLE;
16854 	if (idle) {
16855 		if (tp->t_flags & TF_MORETOCOME) {
16856 			tp->t_flags |= TF_LASTIDLE;
16857 			idle = 0;
16858 		}
16859 	}
16860 	if ((tp->snd_una == tp->snd_max) &&
16861 	    rack->r_ctl.rc_went_idle_time &&
16862 	    TSTMP_GT(cts, rack->r_ctl.rc_went_idle_time)) {
16863 		idle = cts - rack->r_ctl.rc_went_idle_time;
16864 		if (idle > rack_min_probertt_hold) {
16865 			/* Count as a probe rtt */
16866 			if (rack->in_probe_rtt == 0) {
16867 				rack->r_ctl.rc_lower_rtt_us_cts = cts;
16868 				rack->r_ctl.rc_time_probertt_entered = rack->r_ctl.rc_lower_rtt_us_cts;
16869 				rack->r_ctl.rc_time_probertt_starts = rack->r_ctl.rc_lower_rtt_us_cts;
16870 				rack->r_ctl.rc_time_of_last_probertt = rack->r_ctl.rc_lower_rtt_us_cts;
16871 			} else {
16872 				rack_exit_probertt(rack, cts);
16873 			}
16874 		}
16875 		idle = 0;
16876 	}
16877 	if (rack_use_fsb && (rack->r_fsb_inited == 0) && (rack->r_state != TCPS_CLOSED))
16878 		rack_init_fsb_block(tp, rack);
16879 again:
16880 	/*
16881 	 * If we've recently taken a timeout, snd_max will be greater than
16882 	 * snd_nxt.  There may be SACK information that allows us to avoid
16883 	 * resending already delivered data.  Adjust snd_nxt accordingly.
16884 	 */
16885 	sendalot = 0;
16886 	cts = tcp_get_usecs(&tv);
16887 	ms_cts = tcp_tv_to_mssectick(&tv);
16888 	tso = 0;
16889 	mtu = 0;
16890 	segsiz = min(ctf_fixed_maxseg(tp), rack->r_ctl.rc_pace_min_segs);
16891 	minseg = segsiz;
16892 	if (rack->r_ctl.rc_pace_max_segs == 0)
16893 		pace_max_seg = rack->rc_user_set_max_segs * segsiz;
16894 	else
16895 		pace_max_seg = rack->r_ctl.rc_pace_max_segs;
16896 	sb_offset = tp->snd_max - tp->snd_una;
16897 	cwnd_to_use = rack->r_ctl.cwnd_to_use = tp->snd_cwnd;
16898 	flags = tcp_outflags[tp->t_state];
16899 	while (rack->rc_free_cnt < rack_free_cache) {
16900 		rsm = rack_alloc(rack);
16901 		if (rsm == NULL) {
16902 			if (inp->inp_hpts_calls)
16903 				/* Retry in a ms */
16904 				slot = (1 * HPTS_USEC_IN_MSEC);
16905 			so = inp->inp_socket;
16906 			sb = &so->so_snd;
16907 			goto just_return_nolock;
16908 		}
16909 		TAILQ_INSERT_TAIL(&rack->r_ctl.rc_free, rsm, r_tnext);
16910 		rack->rc_free_cnt++;
16911 		rsm = NULL;
16912 	}
16913 	if (inp->inp_hpts_calls)
16914 		inp->inp_hpts_calls = 0;
16915 	sack_rxmit = 0;
16916 	len = 0;
16917 	rsm = NULL;
16918 	if (flags & TH_RST) {
16919 		SOCKBUF_LOCK(&inp->inp_socket->so_snd);
16920 		so = inp->inp_socket;
16921 		sb = &so->so_snd;
16922 		goto send;
16923 	}
16924 	if (rack->r_ctl.rc_resend) {
16925 		/* Retransmit timer */
16926 		rsm = rack->r_ctl.rc_resend;
16927 		rack->r_ctl.rc_resend = NULL;
16928 		len = rsm->r_end - rsm->r_start;
16929 		sack_rxmit = 1;
16930 		sendalot = 0;
16931 		KASSERT(SEQ_LEQ(tp->snd_una, rsm->r_start),
16932 			("%s:%d: r.start:%u < SND.UNA:%u; tp:%p, rack:%p, rsm:%p",
16933 			 __func__, __LINE__,
16934 			 rsm->r_start, tp->snd_una, tp, rack, rsm));
16935 		sb_offset = rsm->r_start - tp->snd_una;
16936 		if (len >= segsiz)
16937 			len = segsiz;
16938 	} else if ((rsm = tcp_rack_output(tp, rack, cts)) != NULL) {
16939 		/* We have a retransmit that takes precedence */
16940 		if ((!IN_FASTRECOVERY(tp->t_flags)) &&
16941 		    ((tp->t_flags & TF_WASFRECOVERY) == 0)) {
16942 			/* Enter recovery if not induced by a time-out */
16943 			rack->r_ctl.rc_rsm_start = rsm->r_start;
16944 			rack->r_ctl.rc_cwnd_at = tp->snd_cwnd;
16945 			rack->r_ctl.rc_ssthresh_at = tp->snd_ssthresh;
16946 			rack_cong_signal(tp, CC_NDUPACK, tp->snd_una);
16947 		}
16948 #ifdef INVARIANTS
16949 		if (SEQ_LT(rsm->r_start, tp->snd_una)) {
16950 			panic("Huh, tp:%p rack:%p rsm:%p start:%u < snd_una:%u\n",
16951 			      tp, rack, rsm, rsm->r_start, tp->snd_una);
16952 		}
16953 #endif
16954 		len = rsm->r_end - rsm->r_start;
16955 		KASSERT(SEQ_LEQ(tp->snd_una, rsm->r_start),
16956 			("%s:%d: r.start:%u < SND.UNA:%u; tp:%p, rack:%p, rsm:%p",
16957 			 __func__, __LINE__,
16958 			 rsm->r_start, tp->snd_una, tp, rack, rsm));
16959 		sb_offset = rsm->r_start - tp->snd_una;
16960 		sendalot = 0;
16961 		if (len >= segsiz)
16962 			len = segsiz;
16963 		if (len > 0) {
16964 			sack_rxmit = 1;
16965 			KMOD_TCPSTAT_INC(tcps_sack_rexmits);
16966 			KMOD_TCPSTAT_ADD(tcps_sack_rexmit_bytes,
16967 			    min(len, segsiz));
16968 			counter_u64_add(rack_rtm_prr_retran, 1);
16969 		}
16970 	} else if (rack->r_ctl.rc_tlpsend) {
16971 		/* Tail loss probe */
16972 		long cwin;
16973 		long tlen;
16974 
16975 		/*
16976 		 * Check if we can do a TLP with a RACK'd packet
16977 		 * this can happen if we are not doing the rack
16978 		 * cheat and we skipped to a TLP and it
16979 		 * went off.
16980 		 */
16981 		rsm = rack->r_ctl.rc_tlpsend;
16982 		/* We are doing a TLP make sure the flag is preent */
16983 		rsm->r_flags |= RACK_TLP;
16984 		rack->r_ctl.rc_tlpsend = NULL;
16985 		sack_rxmit = 1;
16986 		tlen = rsm->r_end - rsm->r_start;
16987 		if (tlen > segsiz)
16988 			tlen = segsiz;
16989 		KASSERT(SEQ_LEQ(tp->snd_una, rsm->r_start),
16990 			("%s:%d: r.start:%u < SND.UNA:%u; tp:%p, rack:%p, rsm:%p",
16991 			 __func__, __LINE__,
16992 			 rsm->r_start, tp->snd_una, tp, rack, rsm));
16993 		sb_offset = rsm->r_start - tp->snd_una;
16994 		cwin = min(tp->snd_wnd, tlen);
16995 		len = cwin;
16996 	}
16997 	if (rack->r_must_retran &&
16998 	    (rsm == NULL)) {
16999 		/*
17000 		 * Non-Sack and we had a RTO or MTU change, we
17001 		 * need to retransmit until we reach
17002 		 * the former snd_max (rack->r_ctl.rc_snd_max_at_rto).
17003 		 */
17004 		if (SEQ_GT(tp->snd_max, tp->snd_una)) {
17005 			int sendwin, flight;
17006 
17007 			sendwin = min(tp->snd_wnd, tp->snd_cwnd);
17008 			flight = ctf_flight_size(tp, rack->r_ctl.rc_out_at_rto);
17009 			if (flight >= sendwin) {
17010 				so = inp->inp_socket;
17011 				sb = &so->so_snd;
17012 				goto just_return_nolock;
17013 			}
17014 			rsm = TAILQ_FIRST(&rack->r_ctl.rc_tmap);
17015 			if (rsm == NULL) {
17016 				/* TSNH */
17017 				rack->r_must_retran = 0;
17018 				rack->r_ctl.rc_out_at_rto = 0;
17019 				rack->r_must_retran = 0;
17020 				so = inp->inp_socket;
17021 				sb = &so->so_snd;
17022 				goto just_return_nolock;
17023 			}
17024 			sack_rxmit = 1;
17025 			len = rsm->r_end - rsm->r_start;
17026 			sendalot = 0;
17027 			sb_offset = rsm->r_start - tp->snd_una;
17028 			if (len >= segsiz)
17029 				len = segsiz;
17030 		} else {
17031 			/* We must be done if there is nothing outstanding */
17032 			rack->r_must_retran = 0;
17033 			rack->r_ctl.rc_out_at_rto = 0;
17034 		}
17035 	}
17036 	/*
17037 	 * Enforce a connection sendmap count limit if set
17038 	 * as long as we are not retransmiting.
17039 	 */
17040 	if ((rsm == NULL) &&
17041 	    (rack->do_detection == 0) &&
17042 	    (V_tcp_map_entries_limit > 0) &&
17043 	    (rack->r_ctl.rc_num_maps_alloced >= V_tcp_map_entries_limit)) {
17044 		counter_u64_add(rack_to_alloc_limited, 1);
17045 		if (!rack->alloc_limit_reported) {
17046 			rack->alloc_limit_reported = 1;
17047 			counter_u64_add(rack_alloc_limited_conns, 1);
17048 		}
17049 		so = inp->inp_socket;
17050 		sb = &so->so_snd;
17051 		goto just_return_nolock;
17052 	}
17053 	if (rsm && (rsm->r_flags & RACK_HAS_FIN)) {
17054 		/* we are retransmitting the fin */
17055 		len--;
17056 		if (len) {
17057 			/*
17058 			 * When retransmitting data do *not* include the
17059 			 * FIN. This could happen from a TLP probe.
17060 			 */
17061 			flags &= ~TH_FIN;
17062 		}
17063 	}
17064 #ifdef INVARIANTS
17065 	/* For debugging */
17066 	rack->r_ctl.rc_rsm_at_retran = rsm;
17067 #endif
17068 	if (rsm && rack->r_fsb_inited && rack_use_rsm_rfo &&
17069 	    ((rsm->r_flags & RACK_HAS_FIN) == 0)) {
17070 		int ret;
17071 
17072 		ret = rack_fast_rsm_output(tp, rack, rsm, ts_val, cts, ms_cts, &tv, len, doing_tlp);
17073 		if (ret == 0)
17074 			return (0);
17075 	}
17076 	so = inp->inp_socket;
17077 	sb = &so->so_snd;
17078 	if (do_a_prefetch == 0) {
17079 		kern_prefetch(sb, &do_a_prefetch);
17080 		do_a_prefetch = 1;
17081 	}
17082 #ifdef NETFLIX_SHARED_CWND
17083 	if ((tp->t_flags2 & TF2_TCP_SCWND_ALLOWED) &&
17084 	    rack->rack_enable_scwnd) {
17085 		/* We are doing cwnd sharing */
17086 		if (rack->gp_ready &&
17087 		    (rack->rack_attempted_scwnd == 0) &&
17088 		    (rack->r_ctl.rc_scw == NULL) &&
17089 		    tp->t_lib) {
17090 			/* The pcbid is in, lets make an attempt */
17091 			counter_u64_add(rack_try_scwnd, 1);
17092 			rack->rack_attempted_scwnd = 1;
17093 			rack->r_ctl.rc_scw = tcp_shared_cwnd_alloc(tp,
17094 								   &rack->r_ctl.rc_scw_index,
17095 								   segsiz);
17096 		}
17097 		if (rack->r_ctl.rc_scw &&
17098 		    (rack->rack_scwnd_is_idle == 1) &&
17099 		    sbavail(&so->so_snd)) {
17100 			/* we are no longer out of data */
17101 			tcp_shared_cwnd_active(rack->r_ctl.rc_scw, rack->r_ctl.rc_scw_index);
17102 			rack->rack_scwnd_is_idle = 0;
17103 		}
17104 		if (rack->r_ctl.rc_scw) {
17105 			/* First lets update and get the cwnd */
17106 			rack->r_ctl.cwnd_to_use = cwnd_to_use = tcp_shared_cwnd_update(rack->r_ctl.rc_scw,
17107 								    rack->r_ctl.rc_scw_index,
17108 								    tp->snd_cwnd, tp->snd_wnd, segsiz);
17109 		}
17110 	}
17111 #endif
17112 	/*
17113 	 * Get standard flags, and add SYN or FIN if requested by 'hidden'
17114 	 * state flags.
17115 	 */
17116 	if (tp->t_flags & TF_NEEDFIN)
17117 		flags |= TH_FIN;
17118 	if (tp->t_flags & TF_NEEDSYN)
17119 		flags |= TH_SYN;
17120 	if ((sack_rxmit == 0) && (prefetch_rsm == 0)) {
17121 		void *end_rsm;
17122 		end_rsm = TAILQ_LAST_FAST(&rack->r_ctl.rc_tmap, rack_sendmap, r_tnext);
17123 		if (end_rsm)
17124 			kern_prefetch(end_rsm, &prefetch_rsm);
17125 		prefetch_rsm = 1;
17126 	}
17127 	SOCKBUF_LOCK(sb);
17128 	/*
17129 	 * If snd_nxt == snd_max and we have transmitted a FIN, the
17130 	 * sb_offset will be > 0 even if so_snd.sb_cc is 0, resulting in a
17131 	 * negative length.  This can also occur when TCP opens up its
17132 	 * congestion window while receiving additional duplicate acks after
17133 	 * fast-retransmit because TCP will reset snd_nxt to snd_max after
17134 	 * the fast-retransmit.
17135 	 *
17136 	 * In the normal retransmit-FIN-only case, however, snd_nxt will be
17137 	 * set to snd_una, the sb_offset will be 0, and the length may wind
17138 	 * up 0.
17139 	 *
17140 	 * If sack_rxmit is true we are retransmitting from the scoreboard
17141 	 * in which case len is already set.
17142 	 */
17143 	if ((sack_rxmit == 0) &&
17144 	    (TCPS_HAVEESTABLISHED(tp->t_state) || IS_FASTOPEN(tp->t_flags))) {
17145 		uint32_t avail;
17146 
17147 		avail = sbavail(sb);
17148 		if (SEQ_GT(tp->snd_nxt, tp->snd_una) && avail)
17149 			sb_offset = tp->snd_nxt - tp->snd_una;
17150 		else
17151 			sb_offset = 0;
17152 		if ((IN_FASTRECOVERY(tp->t_flags) == 0) || rack->rack_no_prr) {
17153 			if (rack->r_ctl.rc_tlp_new_data) {
17154 				/* TLP is forcing out new data */
17155 				if (rack->r_ctl.rc_tlp_new_data > (uint32_t) (avail - sb_offset)) {
17156 					rack->r_ctl.rc_tlp_new_data = (uint32_t) (avail - sb_offset);
17157 				}
17158 				if ((rack->r_ctl.rc_tlp_new_data + sb_offset) > tp->snd_wnd) {
17159 					if (tp->snd_wnd > sb_offset)
17160 						len = tp->snd_wnd - sb_offset;
17161 					else
17162 						len = 0;
17163 				} else {
17164 					len = rack->r_ctl.rc_tlp_new_data;
17165 				}
17166 			}  else {
17167 				len = rack_what_can_we_send(tp, rack, cwnd_to_use, avail, sb_offset);
17168 			}
17169 			if ((rack->r_ctl.crte == NULL) && IN_FASTRECOVERY(tp->t_flags) && (len > segsiz)) {
17170 				/*
17171 				 * For prr=off, we need to send only 1 MSS
17172 				 * at a time. We do this because another sack could
17173 				 * be arriving that causes us to send retransmits and
17174 				 * we don't want to be on a long pace due to a larger send
17175 				 * that keeps us from sending out the retransmit.
17176 				 */
17177 				len = segsiz;
17178 			}
17179 		} else {
17180 			uint32_t outstanding;
17181 			/*
17182 			 * We are inside of a Fast recovery episode, this
17183 			 * is caused by a SACK or 3 dup acks. At this point
17184 			 * we have sent all the retransmissions and we rely
17185 			 * on PRR to dictate what we will send in the form of
17186 			 * new data.
17187 			 */
17188 
17189 			outstanding = tp->snd_max - tp->snd_una;
17190 			if ((rack->r_ctl.rc_prr_sndcnt + outstanding) > tp->snd_wnd) {
17191 				if (tp->snd_wnd > outstanding) {
17192 					len = tp->snd_wnd - outstanding;
17193 					/* Check to see if we have the data */
17194 					if ((sb_offset + len) > avail) {
17195 						/* It does not all fit */
17196 						if (avail > sb_offset)
17197 							len = avail - sb_offset;
17198 						else
17199 							len = 0;
17200 					}
17201 				} else {
17202 					len = 0;
17203 				}
17204 			} else if (avail > sb_offset) {
17205 				len = avail - sb_offset;
17206 			} else {
17207 				len = 0;
17208 			}
17209 			if (len > 0) {
17210 				if (len > rack->r_ctl.rc_prr_sndcnt) {
17211 					len = rack->r_ctl.rc_prr_sndcnt;
17212 				}
17213 				if (len > 0) {
17214 					sub_from_prr = 1;
17215 					counter_u64_add(rack_rtm_prr_newdata, 1);
17216 				}
17217 			}
17218 			if (len > segsiz) {
17219 				/*
17220 				 * We should never send more than a MSS when
17221 				 * retransmitting or sending new data in prr
17222 				 * mode unless the override flag is on. Most
17223 				 * likely the PRR algorithm is not going to
17224 				 * let us send a lot as well :-)
17225 				 */
17226 				if (rack->r_ctl.rc_prr_sendalot == 0) {
17227 					len = segsiz;
17228 				}
17229 			} else if (len < segsiz) {
17230 				/*
17231 				 * Do we send any? The idea here is if the
17232 				 * send empty's the socket buffer we want to
17233 				 * do it. However if not then lets just wait
17234 				 * for our prr_sndcnt to get bigger.
17235 				 */
17236 				long leftinsb;
17237 
17238 				leftinsb = sbavail(sb) - sb_offset;
17239 				if (leftinsb > len) {
17240 					/* This send does not empty the sb */
17241 					len = 0;
17242 				}
17243 			}
17244 		}
17245 	} else if (!TCPS_HAVEESTABLISHED(tp->t_state)) {
17246 		/*
17247 		 * If you have not established
17248 		 * and are not doing FAST OPEN
17249 		 * no data please.
17250 		 */
17251 		if ((sack_rxmit == 0) &&
17252 		    (!IS_FASTOPEN(tp->t_flags))){
17253 			len = 0;
17254 			sb_offset = 0;
17255 		}
17256 	}
17257 	if (prefetch_so_done == 0) {
17258 		kern_prefetch(so, &prefetch_so_done);
17259 		prefetch_so_done = 1;
17260 	}
17261 	/*
17262 	 * Lop off SYN bit if it has already been sent.  However, if this is
17263 	 * SYN-SENT state and if segment contains data and if we don't know
17264 	 * that foreign host supports TAO, suppress sending segment.
17265 	 */
17266 	if ((flags & TH_SYN) && SEQ_GT(tp->snd_nxt, tp->snd_una) &&
17267 	    ((sack_rxmit == 0) && (tp->t_rxtshift == 0))) {
17268 		/*
17269 		 * When sending additional segments following a TFO SYN|ACK,
17270 		 * do not include the SYN bit.
17271 		 */
17272 		if (IS_FASTOPEN(tp->t_flags) &&
17273 		    (tp->t_state == TCPS_SYN_RECEIVED))
17274 			flags &= ~TH_SYN;
17275 	}
17276 	/*
17277 	 * Be careful not to send data and/or FIN on SYN segments. This
17278 	 * measure is needed to prevent interoperability problems with not
17279 	 * fully conformant TCP implementations.
17280 	 */
17281 	if ((flags & TH_SYN) && (tp->t_flags & TF_NOOPT)) {
17282 		len = 0;
17283 		flags &= ~TH_FIN;
17284 	}
17285 	/*
17286 	 * On TFO sockets, ensure no data is sent in the following cases:
17287 	 *
17288 	 *  - When retransmitting SYN|ACK on a passively-created socket
17289 	 *
17290 	 *  - When retransmitting SYN on an actively created socket
17291 	 *
17292 	 *  - When sending a zero-length cookie (cookie request) on an
17293 	 *    actively created socket
17294 	 *
17295 	 *  - When the socket is in the CLOSED state (RST is being sent)
17296 	 */
17297 	if (IS_FASTOPEN(tp->t_flags) &&
17298 	    (((flags & TH_SYN) && (tp->t_rxtshift > 0)) ||
17299 	     ((tp->t_state == TCPS_SYN_SENT) &&
17300 	      (tp->t_tfo_client_cookie_len == 0)) ||
17301 	     (flags & TH_RST))) {
17302 		sack_rxmit = 0;
17303 		len = 0;
17304 	}
17305 	/* Without fast-open there should never be data sent on a SYN */
17306 	if ((flags & TH_SYN) && (!IS_FASTOPEN(tp->t_flags))) {
17307 		tp->snd_nxt = tp->iss;
17308 		len = 0;
17309 	}
17310 	if ((len > segsiz) && (tcp_dsack_block_exists(tp))) {
17311 		/* We only send 1 MSS if we have a DSACK block */
17312 		add_flag |= RACK_SENT_W_DSACK;
17313 		len = segsiz;
17314 	}
17315 	orig_len = len;
17316 	if (len <= 0) {
17317 		/*
17318 		 * If FIN has been sent but not acked, but we haven't been
17319 		 * called to retransmit, len will be < 0.  Otherwise, window
17320 		 * shrank after we sent into it.  If window shrank to 0,
17321 		 * cancel pending retransmit, pull snd_nxt back to (closed)
17322 		 * window, and set the persist timer if it isn't already
17323 		 * going.  If the window didn't close completely, just wait
17324 		 * for an ACK.
17325 		 *
17326 		 * We also do a general check here to ensure that we will
17327 		 * set the persist timer when we have data to send, but a
17328 		 * 0-byte window. This makes sure the persist timer is set
17329 		 * even if the packet hits one of the "goto send" lines
17330 		 * below.
17331 		 */
17332 		len = 0;
17333 		if ((tp->snd_wnd == 0) &&
17334 		    (TCPS_HAVEESTABLISHED(tp->t_state)) &&
17335 		    (tp->snd_una == tp->snd_max) &&
17336 		    (sb_offset < (int)sbavail(sb))) {
17337 			rack_enter_persist(tp, rack, cts);
17338 		}
17339 	} else if ((rsm == NULL) &&
17340 		   (doing_tlp == 0) &&
17341 		   (len < pace_max_seg)) {
17342 		/*
17343 		 * We are not sending a maximum sized segment for
17344 		 * some reason. Should we not send anything (think
17345 		 * sws or persists)?
17346 		 */
17347 		if ((tp->snd_wnd < min((rack->r_ctl.rc_high_rwnd/2), minseg)) &&
17348 		    (TCPS_HAVEESTABLISHED(tp->t_state)) &&
17349 		    (len < minseg) &&
17350 		    (len < (int)(sbavail(sb) - sb_offset))) {
17351 			/*
17352 			 * Here the rwnd is less than
17353 			 * the minimum pacing size, this is not a retransmit,
17354 			 * we are established and
17355 			 * the send is not the last in the socket buffer
17356 			 * we send nothing, and we may enter persists
17357 			 * if nothing is outstanding.
17358 			 */
17359 			len = 0;
17360 			if (tp->snd_max == tp->snd_una) {
17361 				/*
17362 				 * Nothing out we can
17363 				 * go into persists.
17364 				 */
17365 				rack_enter_persist(tp, rack, cts);
17366 			}
17367 		     } else if ((cwnd_to_use >= max(minseg, (segsiz * 4))) &&
17368 			   (ctf_flight_size(tp, rack->r_ctl.rc_sacked) > (2 * segsiz)) &&
17369 			   (len < (int)(sbavail(sb) - sb_offset)) &&
17370 			   (len < minseg)) {
17371 			/*
17372 			 * Here we are not retransmitting, and
17373 			 * the cwnd is not so small that we could
17374 			 * not send at least a min size (rxt timer
17375 			 * not having gone off), We have 2 segments or
17376 			 * more already in flight, its not the tail end
17377 			 * of the socket buffer  and the cwnd is blocking
17378 			 * us from sending out a minimum pacing segment size.
17379 			 * Lets not send anything.
17380 			 */
17381 			len = 0;
17382 		} else if (((tp->snd_wnd - ctf_outstanding(tp)) <
17383 			    min((rack->r_ctl.rc_high_rwnd/2), minseg)) &&
17384 			   (ctf_flight_size(tp, rack->r_ctl.rc_sacked) > (2 * segsiz)) &&
17385 			   (len < (int)(sbavail(sb) - sb_offset)) &&
17386 			   (TCPS_HAVEESTABLISHED(tp->t_state))) {
17387 			/*
17388 			 * Here we have a send window but we have
17389 			 * filled it up and we can't send another pacing segment.
17390 			 * We also have in flight more than 2 segments
17391 			 * and we are not completing the sb i.e. we allow
17392 			 * the last bytes of the sb to go out even if
17393 			 * its not a full pacing segment.
17394 			 */
17395 			len = 0;
17396 		} else if ((rack->r_ctl.crte != NULL) &&
17397 			   (tp->snd_wnd >= (pace_max_seg * max(1, rack_hw_rwnd_factor))) &&
17398 			   (cwnd_to_use >= (pace_max_seg + (4 * segsiz))) &&
17399 			   (ctf_flight_size(tp, rack->r_ctl.rc_sacked) >= (2 * segsiz)) &&
17400 			   (len < (int)(sbavail(sb) - sb_offset))) {
17401 			/*
17402 			 * Here we are doing hardware pacing, this is not a TLP,
17403 			 * we are not sending a pace max segment size, there is rwnd
17404 			 * room to send at least N pace_max_seg, the cwnd is greater
17405 			 * than or equal to a full pacing segments plus 4 mss and we have 2 or
17406 			 * more segments in flight and its not the tail of the socket buffer.
17407 			 *
17408 			 * We don't want to send instead we need to get more ack's in to
17409 			 * allow us to send a full pacing segment. Normally, if we are pacing
17410 			 * about the right speed, we should have finished our pacing
17411 			 * send as most of the acks have come back if we are at the
17412 			 * right rate. This is a bit fuzzy since return path delay
17413 			 * can delay the acks, which is why we want to make sure we
17414 			 * have cwnd space to have a bit more than a max pace segments in flight.
17415 			 *
17416 			 * If we have not gotten our acks back we are pacing at too high a
17417 			 * rate delaying will not hurt and will bring our GP estimate down by
17418 			 * injecting the delay. If we don't do this we will send
17419 			 * 2 MSS out in response to the acks being clocked in which
17420 			 * defeats the point of hw-pacing (i.e. to help us get
17421 			 * larger TSO's out).
17422 			 */
17423 			len = 0;
17424 
17425 		}
17426 
17427 	}
17428 	/* len will be >= 0 after this point. */
17429 	KASSERT(len >= 0, ("[%s:%d]: len < 0", __func__, __LINE__));
17430 	rack_sndbuf_autoscale(rack);
17431 	/*
17432 	 * Decide if we can use TCP Segmentation Offloading (if supported by
17433 	 * hardware).
17434 	 *
17435 	 * TSO may only be used if we are in a pure bulk sending state.  The
17436 	 * presence of TCP-MD5, SACK retransmits, SACK advertizements and IP
17437 	 * options prevent using TSO.  With TSO the TCP header is the same
17438 	 * (except for the sequence number) for all generated packets.  This
17439 	 * makes it impossible to transmit any options which vary per
17440 	 * generated segment or packet.
17441 	 *
17442 	 * IPv4 handling has a clear separation of ip options and ip header
17443 	 * flags while IPv6 combines both in in6p_outputopts. ip6_optlen() does
17444 	 * the right thing below to provide length of just ip options and thus
17445 	 * checking for ipoptlen is enough to decide if ip options are present.
17446 	 */
17447 	ipoptlen = 0;
17448 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
17449 	/*
17450 	 * Pre-calculate here as we save another lookup into the darknesses
17451 	 * of IPsec that way and can actually decide if TSO is ok.
17452 	 */
17453 #ifdef INET6
17454 	if (isipv6 && IPSEC_ENABLED(ipv6))
17455 		ipsec_optlen = IPSEC_HDRSIZE(ipv6, tp->t_inpcb);
17456 #ifdef INET
17457 	else
17458 #endif
17459 #endif				/* INET6 */
17460 #ifdef INET
17461 		if (IPSEC_ENABLED(ipv4))
17462 			ipsec_optlen = IPSEC_HDRSIZE(ipv4, tp->t_inpcb);
17463 #endif				/* INET */
17464 #endif
17465 
17466 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
17467 	ipoptlen += ipsec_optlen;
17468 #endif
17469 	if ((tp->t_flags & TF_TSO) && V_tcp_do_tso && len > segsiz &&
17470 	    (tp->t_port == 0) &&
17471 	    ((tp->t_flags & TF_SIGNATURE) == 0) &&
17472 	    tp->rcv_numsacks == 0 && sack_rxmit == 0 &&
17473 	    ipoptlen == 0)
17474 		tso = 1;
17475 	{
17476 		uint32_t outstanding;
17477 
17478 		outstanding = tp->snd_max - tp->snd_una;
17479 		if (tp->t_flags & TF_SENTFIN) {
17480 			/*
17481 			 * If we sent a fin, snd_max is 1 higher than
17482 			 * snd_una
17483 			 */
17484 			outstanding--;
17485 		}
17486 		if (sack_rxmit) {
17487 			if ((rsm->r_flags & RACK_HAS_FIN) == 0)
17488 				flags &= ~TH_FIN;
17489 		} else {
17490 			if (SEQ_LT(tp->snd_nxt + len, tp->snd_una +
17491 				   sbused(sb)))
17492 				flags &= ~TH_FIN;
17493 		}
17494 	}
17495 	recwin = lmin(lmax(sbspace(&so->so_rcv), 0),
17496 	    (long)TCP_MAXWIN << tp->rcv_scale);
17497 
17498 	/*
17499 	 * Sender silly window avoidance.   We transmit under the following
17500 	 * conditions when len is non-zero:
17501 	 *
17502 	 * - We have a full segment (or more with TSO) - This is the last
17503 	 * buffer in a write()/send() and we are either idle or running
17504 	 * NODELAY - we've timed out (e.g. persist timer) - we have more
17505 	 * then 1/2 the maximum send window's worth of data (receiver may be
17506 	 * limited the window size) - we need to retransmit
17507 	 */
17508 	if (len) {
17509 		if (len >= segsiz) {
17510 			goto send;
17511 		}
17512 		/*
17513 		 * NOTE! on localhost connections an 'ack' from the remote
17514 		 * end may occur synchronously with the output and cause us
17515 		 * to flush a buffer queued with moretocome.  XXX
17516 		 *
17517 		 */
17518 		if (!(tp->t_flags & TF_MORETOCOME) &&	/* normal case */
17519 		    (idle || (tp->t_flags & TF_NODELAY)) &&
17520 		    ((uint32_t)len + (uint32_t)sb_offset >= sbavail(sb)) &&
17521 		    (tp->t_flags & TF_NOPUSH) == 0) {
17522 			pass = 2;
17523 			goto send;
17524 		}
17525 		if ((tp->snd_una == tp->snd_max) && len) {	/* Nothing outstanding */
17526 			pass = 22;
17527 			goto send;
17528 		}
17529 		if (len >= tp->max_sndwnd / 2 && tp->max_sndwnd > 0) {
17530 			pass = 4;
17531 			goto send;
17532 		}
17533 		if (SEQ_LT(tp->snd_nxt, tp->snd_max)) {	/* retransmit case */
17534 			pass = 5;
17535 			goto send;
17536 		}
17537 		if (sack_rxmit) {
17538 			pass = 6;
17539 			goto send;
17540 		}
17541 		if (((tp->snd_wnd - ctf_outstanding(tp)) < segsiz) &&
17542 		    (ctf_outstanding(tp) < (segsiz * 2))) {
17543 			/*
17544 			 * We have less than two MSS outstanding (delayed ack)
17545 			 * and our rwnd will not let us send a full sized
17546 			 * MSS. Lets go ahead and let this small segment
17547 			 * out because we want to try to have at least two
17548 			 * packets inflight to not be caught by delayed ack.
17549 			 */
17550 			pass = 12;
17551 			goto send;
17552 		}
17553 	}
17554 	/*
17555 	 * Sending of standalone window updates.
17556 	 *
17557 	 * Window updates are important when we close our window due to a
17558 	 * full socket buffer and are opening it again after the application
17559 	 * reads data from it.  Once the window has opened again and the
17560 	 * remote end starts to send again the ACK clock takes over and
17561 	 * provides the most current window information.
17562 	 *
17563 	 * We must avoid the silly window syndrome whereas every read from
17564 	 * the receive buffer, no matter how small, causes a window update
17565 	 * to be sent.  We also should avoid sending a flurry of window
17566 	 * updates when the socket buffer had queued a lot of data and the
17567 	 * application is doing small reads.
17568 	 *
17569 	 * Prevent a flurry of pointless window updates by only sending an
17570 	 * update when we can increase the advertized window by more than
17571 	 * 1/4th of the socket buffer capacity.  When the buffer is getting
17572 	 * full or is very small be more aggressive and send an update
17573 	 * whenever we can increase by two mss sized segments. In all other
17574 	 * situations the ACK's to new incoming data will carry further
17575 	 * window increases.
17576 	 *
17577 	 * Don't send an independent window update if a delayed ACK is
17578 	 * pending (it will get piggy-backed on it) or the remote side
17579 	 * already has done a half-close and won't send more data.  Skip
17580 	 * this if the connection is in T/TCP half-open state.
17581 	 */
17582 	if (recwin > 0 && !(tp->t_flags & TF_NEEDSYN) &&
17583 	    !(tp->t_flags & TF_DELACK) &&
17584 	    !TCPS_HAVERCVDFIN(tp->t_state)) {
17585 		/*
17586 		 * "adv" is the amount we could increase the window, taking
17587 		 * into account that we are limited by TCP_MAXWIN <<
17588 		 * tp->rcv_scale.
17589 		 */
17590 		int32_t adv;
17591 		int oldwin;
17592 
17593 		adv = recwin;
17594 		if (SEQ_GT(tp->rcv_adv, tp->rcv_nxt)) {
17595 			oldwin = (tp->rcv_adv - tp->rcv_nxt);
17596 			if (adv > oldwin)
17597 			    adv -= oldwin;
17598 			else {
17599 				/* We can't increase the window */
17600 				adv = 0;
17601 			}
17602 		} else
17603 			oldwin = 0;
17604 
17605 		/*
17606 		 * If the new window size ends up being the same as or less
17607 		 * than the old size when it is scaled, then don't force
17608 		 * a window update.
17609 		 */
17610 		if (oldwin >> tp->rcv_scale >= (adv + oldwin) >> tp->rcv_scale)
17611 			goto dontupdate;
17612 
17613 		if (adv >= (int32_t)(2 * segsiz) &&
17614 		    (adv >= (int32_t)(so->so_rcv.sb_hiwat / 4) ||
17615 		     recwin <= (int32_t)(so->so_rcv.sb_hiwat / 8) ||
17616 		     so->so_rcv.sb_hiwat <= 8 * segsiz)) {
17617 			pass = 7;
17618 			goto send;
17619 		}
17620 		if (2 * adv >= (int32_t) so->so_rcv.sb_hiwat) {
17621 			pass = 23;
17622 			goto send;
17623 		}
17624 	}
17625 dontupdate:
17626 
17627 	/*
17628 	 * Send if we owe the peer an ACK, RST, SYN, or urgent data.  ACKNOW
17629 	 * is also a catch-all for the retransmit timer timeout case.
17630 	 */
17631 	if (tp->t_flags & TF_ACKNOW) {
17632 		pass = 8;
17633 		goto send;
17634 	}
17635 	if (((flags & TH_SYN) && (tp->t_flags & TF_NEEDSYN) == 0)) {
17636 		pass = 9;
17637 		goto send;
17638 	}
17639 	/*
17640 	 * If our state indicates that FIN should be sent and we have not
17641 	 * yet done so, then we need to send.
17642 	 */
17643 	if ((flags & TH_FIN) &&
17644 	    (tp->snd_nxt == tp->snd_una)) {
17645 		pass = 11;
17646 		goto send;
17647 	}
17648 	/*
17649 	 * No reason to send a segment, just return.
17650 	 */
17651 just_return:
17652 	SOCKBUF_UNLOCK(sb);
17653 just_return_nolock:
17654 	{
17655 		int app_limited = CTF_JR_SENT_DATA;
17656 
17657 		if (tot_len_this_send > 0) {
17658 			/* Make sure snd_nxt is up to max */
17659 			rack->r_ctl.fsb.recwin = recwin;
17660 			slot = rack_get_pacing_delay(rack, tp, tot_len_this_send, NULL, segsiz);
17661 			if ((error == 0) &&
17662 			    rack_use_rfo &&
17663 			    ((flags & (TH_SYN|TH_FIN)) == 0) &&
17664 			    (ipoptlen == 0) &&
17665 			    (tp->snd_nxt == tp->snd_max) &&
17666 			    (tp->rcv_numsacks == 0) &&
17667 			    rack->r_fsb_inited &&
17668 			    TCPS_HAVEESTABLISHED(tp->t_state) &&
17669 			    (rack->r_must_retran == 0) &&
17670 			    ((tp->t_flags & TF_NEEDFIN) == 0) &&
17671 			    (len > 0) && (orig_len > 0) &&
17672 			    (orig_len > len) &&
17673 			    ((orig_len - len) >= segsiz) &&
17674 			    ((optlen == 0) ||
17675 			     ((optlen == TCPOLEN_TSTAMP_APPA) && (to.to_flags & TOF_TS)))) {
17676 				/* We can send at least one more MSS using our fsb */
17677 
17678 				rack->r_fast_output = 1;
17679 				rack->r_ctl.fsb.m = sbsndmbuf(sb, (tp->snd_max - tp->snd_una), &rack->r_ctl.fsb.off);
17680 				rack->r_ctl.fsb.o_m_len = rack->r_ctl.fsb.m->m_len;
17681 				rack->r_ctl.fsb.tcp_flags = flags;
17682 				rack->r_ctl.fsb.left_to_send = orig_len - len;
17683 				if (hw_tls)
17684 					rack->r_ctl.fsb.hw_tls = 1;
17685 				else
17686 					rack->r_ctl.fsb.hw_tls = 0;
17687 				KASSERT((rack->r_ctl.fsb.left_to_send <= (sbavail(sb) - (tp->snd_max - tp->snd_una))),
17688 					("rack:%p left_to_send:%u sbavail:%u out:%u",
17689 					rack, rack->r_ctl.fsb.left_to_send, sbavail(sb),
17690 					 (tp->snd_max - tp->snd_una)));
17691 				if (rack->r_ctl.fsb.left_to_send < segsiz)
17692 					rack->r_fast_output = 0;
17693 				else {
17694 					if (rack->r_ctl.fsb.left_to_send == (sbavail(sb) - (tp->snd_max - tp->snd_una)))
17695 						rack->r_ctl.fsb.rfo_apply_push = 1;
17696 					else
17697 						rack->r_ctl.fsb.rfo_apply_push = 0;
17698 				}
17699 			} else
17700 				rack->r_fast_output = 0;
17701 
17702 
17703 			rack_log_fsb(rack, tp, so, flags,
17704 				     ipoptlen, orig_len, len, 0,
17705 				     1, optlen, __LINE__, 1);
17706 			if (SEQ_GT(tp->snd_max, tp->snd_nxt))
17707 				tp->snd_nxt = tp->snd_max;
17708 		} else {
17709 			int end_window = 0;
17710 			uint32_t seq = tp->gput_ack;
17711 
17712 			rsm = RB_MAX(rack_rb_tree_head, &rack->r_ctl.rc_mtree);
17713 			if (rsm) {
17714 				/*
17715 				 * Mark the last sent that we just-returned (hinting
17716 				 * that delayed ack may play a role in any rtt measurement).
17717 				 */
17718 				rsm->r_just_ret = 1;
17719 			}
17720 			counter_u64_add(rack_out_size[TCP_MSS_ACCT_JUSTRET], 1);
17721 			rack->r_ctl.rc_agg_delayed = 0;
17722 			rack->r_early = 0;
17723 			rack->r_late = 0;
17724 			rack->r_ctl.rc_agg_early = 0;
17725 			if ((ctf_outstanding(tp) +
17726 			     min(max(segsiz, (rack->r_ctl.rc_high_rwnd/2)),
17727 				 minseg)) >= tp->snd_wnd) {
17728 				/* We are limited by the rwnd */
17729 				app_limited = CTF_JR_RWND_LIMITED;
17730 				if (IN_FASTRECOVERY(tp->t_flags))
17731 				    rack->r_ctl.rc_prr_sndcnt = 0;
17732 			} else if (ctf_outstanding(tp) >= sbavail(sb)) {
17733 				/* We are limited by whats available -- app limited */
17734 				app_limited = CTF_JR_APP_LIMITED;
17735 				if (IN_FASTRECOVERY(tp->t_flags))
17736 				    rack->r_ctl.rc_prr_sndcnt = 0;
17737 			} else if ((idle == 0) &&
17738 				   ((tp->t_flags & TF_NODELAY) == 0) &&
17739 				   ((uint32_t)len + (uint32_t)sb_offset >= sbavail(sb)) &&
17740 				   (len < segsiz)) {
17741 				/*
17742 				 * No delay is not on and the
17743 				 * user is sending less than 1MSS. This
17744 				 * brings out SWS avoidance so we
17745 				 * don't send. Another app-limited case.
17746 				 */
17747 				app_limited = CTF_JR_APP_LIMITED;
17748 			} else if (tp->t_flags & TF_NOPUSH) {
17749 				/*
17750 				 * The user has requested no push of
17751 				 * the last segment and we are
17752 				 * at the last segment. Another app
17753 				 * limited case.
17754 				 */
17755 				app_limited = CTF_JR_APP_LIMITED;
17756 			} else if ((ctf_outstanding(tp) + minseg) > cwnd_to_use) {
17757 				/* Its the cwnd */
17758 				app_limited = CTF_JR_CWND_LIMITED;
17759 			} else if (IN_FASTRECOVERY(tp->t_flags) &&
17760 				   (rack->rack_no_prr == 0) &&
17761 				   (rack->r_ctl.rc_prr_sndcnt < segsiz)) {
17762 				app_limited = CTF_JR_PRR;
17763 			} else {
17764 				/* Now why here are we not sending? */
17765 #ifdef NOW
17766 #ifdef INVARIANTS
17767 				panic("rack:%p hit JR_ASSESSING case cwnd_to_use:%u?", rack, cwnd_to_use);
17768 #endif
17769 #endif
17770 				app_limited = CTF_JR_ASSESSING;
17771 			}
17772 			/*
17773 			 * App limited in some fashion, for our pacing GP
17774 			 * measurements we don't want any gap (even cwnd).
17775 			 * Close  down the measurement window.
17776 			 */
17777 			if (rack_cwnd_block_ends_measure &&
17778 			    ((app_limited == CTF_JR_CWND_LIMITED) ||
17779 			     (app_limited == CTF_JR_PRR))) {
17780 				/*
17781 				 * The reason we are not sending is
17782 				 * the cwnd (or prr). We have been configured
17783 				 * to end the measurement window in
17784 				 * this case.
17785 				 */
17786 				end_window = 1;
17787 			} else if (rack_rwnd_block_ends_measure &&
17788 				   (app_limited == CTF_JR_RWND_LIMITED)) {
17789 				/*
17790 				 * We are rwnd limited and have been
17791 				 * configured to end the measurement
17792 				 * window in this case.
17793 				 */
17794 				end_window = 1;
17795 			} else if (app_limited == CTF_JR_APP_LIMITED) {
17796 				/*
17797 				 * A true application limited period, we have
17798 				 * ran out of data.
17799 				 */
17800 				end_window = 1;
17801 			} else if (app_limited == CTF_JR_ASSESSING) {
17802 				/*
17803 				 * In the assessing case we hit the end of
17804 				 * the if/else and had no known reason
17805 				 * This will panic us under invariants..
17806 				 *
17807 				 * If we get this out in logs we need to
17808 				 * investagate which reason we missed.
17809 				 */
17810 				end_window = 1;
17811 			}
17812 			if (end_window) {
17813 				uint8_t log = 0;
17814 
17815 				/* Adjust the Gput measurement */
17816 				if ((tp->t_flags & TF_GPUTINPROG) &&
17817 				    SEQ_GT(tp->gput_ack, tp->snd_max)) {
17818 					tp->gput_ack = tp->snd_max;
17819 					if ((tp->gput_ack - tp->gput_seq) < (MIN_GP_WIN * segsiz)) {
17820 						/*
17821 						 * There is not enough to measure.
17822 						 */
17823 						tp->t_flags &= ~TF_GPUTINPROG;
17824 						rack_log_pacing_delay_calc(rack, (tp->gput_ack - tp->gput_seq) /*flex2*/,
17825 									   rack->r_ctl.rc_gp_srtt /*flex1*/,
17826 									   tp->gput_seq,
17827 									   0, 0, 18, __LINE__, NULL, 0);
17828 					} else
17829 						log = 1;
17830 				}
17831 				/* Mark the last packet has app limited */
17832 				rsm = RB_MAX(rack_rb_tree_head, &rack->r_ctl.rc_mtree);
17833 				if (rsm && ((rsm->r_flags & RACK_APP_LIMITED) == 0)) {
17834 					if (rack->r_ctl.rc_app_limited_cnt == 0)
17835 						rack->r_ctl.rc_end_appl = rack->r_ctl.rc_first_appl = rsm;
17836 					else {
17837 						/*
17838 						 * Go out to the end app limited and mark
17839 						 * this new one as next and move the end_appl up
17840 						 * to this guy.
17841 						 */
17842 						if (rack->r_ctl.rc_end_appl)
17843 							rack->r_ctl.rc_end_appl->r_nseq_appl = rsm->r_start;
17844 						rack->r_ctl.rc_end_appl = rsm;
17845 					}
17846 					rsm->r_flags |= RACK_APP_LIMITED;
17847 					rack->r_ctl.rc_app_limited_cnt++;
17848 				}
17849 				if (log)
17850 					rack_log_pacing_delay_calc(rack,
17851 								   rack->r_ctl.rc_app_limited_cnt, seq,
17852 								   tp->gput_ack, 0, 0, 4, __LINE__, NULL, 0);
17853 			}
17854 		}
17855 		if (slot) {
17856 			/* set the rack tcb into the slot N */
17857 			counter_u64_add(rack_paced_segments, 1);
17858 		} else if (tot_len_this_send) {
17859 			counter_u64_add(rack_unpaced_segments, 1);
17860 		}
17861 		/* Check if we need to go into persists or not */
17862 		if ((tp->snd_max == tp->snd_una) &&
17863 		    TCPS_HAVEESTABLISHED(tp->t_state) &&
17864 		    sbavail(sb) &&
17865 		    (sbavail(sb) > tp->snd_wnd) &&
17866 		    (tp->snd_wnd < min((rack->r_ctl.rc_high_rwnd/2), minseg))) {
17867 			/* Yes lets make sure to move to persist before timer-start */
17868 			rack_enter_persist(tp, rack, rack->r_ctl.rc_rcvtime);
17869 		}
17870 		rack_start_hpts_timer(rack, tp, cts, slot, tot_len_this_send, sup_rack);
17871 		rack_log_type_just_return(rack, cts, tot_len_this_send, slot, hpts_calling, app_limited, cwnd_to_use);
17872 	}
17873 #ifdef NETFLIX_SHARED_CWND
17874 	if ((sbavail(sb) == 0) &&
17875 	    rack->r_ctl.rc_scw) {
17876 		tcp_shared_cwnd_idle(rack->r_ctl.rc_scw, rack->r_ctl.rc_scw_index);
17877 		rack->rack_scwnd_is_idle = 1;
17878 	}
17879 #endif
17880 #ifdef TCP_ACCOUNTING
17881 	if (tot_len_this_send > 0) {
17882 		crtsc = get_cyclecount();
17883 		if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
17884 			tp->tcp_cnt_counters[SND_OUT_DATA]++;
17885 		}
17886 		counter_u64_add(tcp_cnt_counters[SND_OUT_DATA], 1);
17887 		if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
17888 			tp->tcp_proc_time[SND_OUT_DATA] += (crtsc - ts_val);
17889 		}
17890 		counter_u64_add(tcp_proc_time[SND_OUT_DATA], (crtsc - ts_val));
17891 		if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
17892 			tp->tcp_cnt_counters[CNT_OF_MSS_OUT] += ((tot_len_this_send + segsiz - 1) / segsiz);
17893 		}
17894 		counter_u64_add(tcp_cnt_counters[CNT_OF_MSS_OUT], ((tot_len_this_send + segsiz - 1) / segsiz));
17895 	} else {
17896 		crtsc = get_cyclecount();
17897 		if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
17898 			tp->tcp_cnt_counters[SND_LIMITED]++;
17899 		}
17900 		counter_u64_add(tcp_cnt_counters[SND_LIMITED], 1);
17901 		if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
17902 			tp->tcp_proc_time[SND_LIMITED] += (crtsc - ts_val);
17903 		}
17904 		counter_u64_add(tcp_proc_time[SND_LIMITED], (crtsc - ts_val));
17905 	}
17906 	sched_unpin();
17907 #endif
17908 	return (0);
17909 
17910 send:
17911 	if (rsm || sack_rxmit)
17912 		counter_u64_add(rack_nfto_resend, 1);
17913 	else
17914 		counter_u64_add(rack_non_fto_send, 1);
17915 	if ((flags & TH_FIN) &&
17916 	    sbavail(sb)) {
17917 		/*
17918 		 * We do not transmit a FIN
17919 		 * with data outstanding. We
17920 		 * need to make it so all data
17921 		 * is acked first.
17922 		 */
17923 		flags &= ~TH_FIN;
17924 	}
17925 	/* Enforce stack imposed max seg size if we have one */
17926 	if (rack->r_ctl.rc_pace_max_segs &&
17927 	    (len > rack->r_ctl.rc_pace_max_segs)) {
17928 		mark = 1;
17929 		len = rack->r_ctl.rc_pace_max_segs;
17930 	}
17931 	SOCKBUF_LOCK_ASSERT(sb);
17932 	if (len > 0) {
17933 		if (len >= segsiz)
17934 			tp->t_flags2 |= TF2_PLPMTU_MAXSEGSNT;
17935 		else
17936 			tp->t_flags2 &= ~TF2_PLPMTU_MAXSEGSNT;
17937 	}
17938 	/*
17939 	 * Before ESTABLISHED, force sending of initial options unless TCP
17940 	 * set not to do any options. NOTE: we assume that the IP/TCP header
17941 	 * plus TCP options always fit in a single mbuf, leaving room for a
17942 	 * maximum link header, i.e. max_linkhdr + sizeof (struct tcpiphdr)
17943 	 * + optlen <= MCLBYTES
17944 	 */
17945 	optlen = 0;
17946 #ifdef INET6
17947 	if (isipv6)
17948 		hdrlen = sizeof(struct ip6_hdr) + sizeof(struct tcphdr);
17949 	else
17950 #endif
17951 		hdrlen = sizeof(struct tcpiphdr);
17952 
17953 	/*
17954 	 * Compute options for segment. We only have to care about SYN and
17955 	 * established connection segments.  Options for SYN-ACK segments
17956 	 * are handled in TCP syncache.
17957 	 */
17958 	to.to_flags = 0;
17959 	if ((tp->t_flags & TF_NOOPT) == 0) {
17960 		/* Maximum segment size. */
17961 		if (flags & TH_SYN) {
17962 			tp->snd_nxt = tp->iss;
17963 			to.to_mss = tcp_mssopt(&inp->inp_inc);
17964 			if (tp->t_port)
17965 				to.to_mss -= V_tcp_udp_tunneling_overhead;
17966 			to.to_flags |= TOF_MSS;
17967 
17968 			/*
17969 			 * On SYN or SYN|ACK transmits on TFO connections,
17970 			 * only include the TFO option if it is not a
17971 			 * retransmit, as the presence of the TFO option may
17972 			 * have caused the original SYN or SYN|ACK to have
17973 			 * been dropped by a middlebox.
17974 			 */
17975 			if (IS_FASTOPEN(tp->t_flags) &&
17976 			    (tp->t_rxtshift == 0)) {
17977 				if (tp->t_state == TCPS_SYN_RECEIVED) {
17978 					to.to_tfo_len = TCP_FASTOPEN_COOKIE_LEN;
17979 					to.to_tfo_cookie =
17980 						(u_int8_t *)&tp->t_tfo_cookie.server;
17981 					to.to_flags |= TOF_FASTOPEN;
17982 					wanted_cookie = 1;
17983 				} else if (tp->t_state == TCPS_SYN_SENT) {
17984 					to.to_tfo_len =
17985 						tp->t_tfo_client_cookie_len;
17986 					to.to_tfo_cookie =
17987 						tp->t_tfo_cookie.client;
17988 					to.to_flags |= TOF_FASTOPEN;
17989 					wanted_cookie = 1;
17990 					/*
17991 					 * If we wind up having more data to
17992 					 * send with the SYN than can fit in
17993 					 * one segment, don't send any more
17994 					 * until the SYN|ACK comes back from
17995 					 * the other end.
17996 					 */
17997 					sendalot = 0;
17998 				}
17999 			}
18000 		}
18001 		/* Window scaling. */
18002 		if ((flags & TH_SYN) && (tp->t_flags & TF_REQ_SCALE)) {
18003 			to.to_wscale = tp->request_r_scale;
18004 			to.to_flags |= TOF_SCALE;
18005 		}
18006 		/* Timestamps. */
18007 		if ((tp->t_flags & TF_RCVD_TSTMP) ||
18008 		    ((flags & TH_SYN) && (tp->t_flags & TF_REQ_TSTMP))) {
18009 			to.to_tsval = ms_cts + tp->ts_offset;
18010 			to.to_tsecr = tp->ts_recent;
18011 			to.to_flags |= TOF_TS;
18012 		}
18013 		/* Set receive buffer autosizing timestamp. */
18014 		if (tp->rfbuf_ts == 0 &&
18015 		    (so->so_rcv.sb_flags & SB_AUTOSIZE))
18016 			tp->rfbuf_ts = tcp_ts_getticks();
18017 		/* Selective ACK's. */
18018 		if (tp->t_flags & TF_SACK_PERMIT) {
18019 			if (flags & TH_SYN)
18020 				to.to_flags |= TOF_SACKPERM;
18021 			else if (TCPS_HAVEESTABLISHED(tp->t_state) &&
18022 				 tp->rcv_numsacks > 0) {
18023 				to.to_flags |= TOF_SACK;
18024 				to.to_nsacks = tp->rcv_numsacks;
18025 				to.to_sacks = (u_char *)tp->sackblks;
18026 			}
18027 		}
18028 #if defined(IPSEC_SUPPORT) || defined(TCP_SIGNATURE)
18029 		/* TCP-MD5 (RFC2385). */
18030 		if (tp->t_flags & TF_SIGNATURE)
18031 			to.to_flags |= TOF_SIGNATURE;
18032 #endif				/* TCP_SIGNATURE */
18033 
18034 		/* Processing the options. */
18035 		hdrlen += optlen = tcp_addoptions(&to, opt);
18036 		/*
18037 		 * If we wanted a TFO option to be added, but it was unable
18038 		 * to fit, ensure no data is sent.
18039 		 */
18040 		if (IS_FASTOPEN(tp->t_flags) && wanted_cookie &&
18041 		    !(to.to_flags & TOF_FASTOPEN))
18042 			len = 0;
18043 	}
18044 	if (tp->t_port) {
18045 		if (V_tcp_udp_tunneling_port == 0) {
18046 			/* The port was removed?? */
18047 			SOCKBUF_UNLOCK(&so->so_snd);
18048 #ifdef TCP_ACCOUNTING
18049 			crtsc = get_cyclecount();
18050 			if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
18051 				tp->tcp_cnt_counters[SND_OUT_FAIL]++;
18052 			}
18053 			counter_u64_add(tcp_cnt_counters[SND_OUT_FAIL], 1);
18054 			if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
18055 				tp->tcp_proc_time[SND_OUT_FAIL] += (crtsc - ts_val);
18056 			}
18057 			counter_u64_add(tcp_proc_time[SND_OUT_FAIL], (crtsc - ts_val));
18058 			sched_unpin();
18059 #endif
18060 			return (EHOSTUNREACH);
18061 		}
18062 		hdrlen += sizeof(struct udphdr);
18063 	}
18064 #ifdef INET6
18065 	if (isipv6)
18066 		ipoptlen = ip6_optlen(tp->t_inpcb);
18067 	else
18068 #endif
18069 		if (tp->t_inpcb->inp_options)
18070 			ipoptlen = tp->t_inpcb->inp_options->m_len -
18071 				offsetof(struct ipoption, ipopt_list);
18072 		else
18073 			ipoptlen = 0;
18074 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
18075 	ipoptlen += ipsec_optlen;
18076 #endif
18077 
18078 	/*
18079 	 * Adjust data length if insertion of options will bump the packet
18080 	 * length beyond the t_maxseg length. Clear the FIN bit because we
18081 	 * cut off the tail of the segment.
18082 	 */
18083 	if (len + optlen + ipoptlen > tp->t_maxseg) {
18084 		if (tso) {
18085 			uint32_t if_hw_tsomax;
18086 			uint32_t moff;
18087 			int32_t max_len;
18088 
18089 			/* extract TSO information */
18090 			if_hw_tsomax = tp->t_tsomax;
18091 			if_hw_tsomaxsegcount = tp->t_tsomaxsegcount;
18092 			if_hw_tsomaxsegsize = tp->t_tsomaxsegsize;
18093 			KASSERT(ipoptlen == 0,
18094 				("%s: TSO can't do IP options", __func__));
18095 
18096 			/*
18097 			 * Check if we should limit by maximum payload
18098 			 * length:
18099 			 */
18100 			if (if_hw_tsomax != 0) {
18101 				/* compute maximum TSO length */
18102 				max_len = (if_hw_tsomax - hdrlen -
18103 					   max_linkhdr);
18104 				if (max_len <= 0) {
18105 					len = 0;
18106 				} else if (len > max_len) {
18107 					sendalot = 1;
18108 					len = max_len;
18109 					mark = 2;
18110 				}
18111 			}
18112 			/*
18113 			 * Prevent the last segment from being fractional
18114 			 * unless the send sockbuf can be emptied:
18115 			 */
18116 			max_len = (tp->t_maxseg - optlen);
18117 			if ((sb_offset + len) < sbavail(sb)) {
18118 				moff = len % (u_int)max_len;
18119 				if (moff != 0) {
18120 					mark = 3;
18121 					len -= moff;
18122 				}
18123 			}
18124 			/*
18125 			 * In case there are too many small fragments don't
18126 			 * use TSO:
18127 			 */
18128 			if (len <= segsiz) {
18129 				mark = 4;
18130 				tso = 0;
18131 			}
18132 			/*
18133 			 * Send the FIN in a separate segment after the bulk
18134 			 * sending is done. We don't trust the TSO
18135 			 * implementations to clear the FIN flag on all but
18136 			 * the last segment.
18137 			 */
18138 			if (tp->t_flags & TF_NEEDFIN) {
18139 				sendalot = 4;
18140 			}
18141 		} else {
18142 			mark = 5;
18143 			if (optlen + ipoptlen >= tp->t_maxseg) {
18144 				/*
18145 				 * Since we don't have enough space to put
18146 				 * the IP header chain and the TCP header in
18147 				 * one packet as required by RFC 7112, don't
18148 				 * send it. Also ensure that at least one
18149 				 * byte of the payload can be put into the
18150 				 * TCP segment.
18151 				 */
18152 				SOCKBUF_UNLOCK(&so->so_snd);
18153 				error = EMSGSIZE;
18154 				sack_rxmit = 0;
18155 				goto out;
18156 			}
18157 			len = tp->t_maxseg - optlen - ipoptlen;
18158 			sendalot = 5;
18159 		}
18160 	} else {
18161 		tso = 0;
18162 		mark = 6;
18163 	}
18164 	KASSERT(len + hdrlen + ipoptlen <= IP_MAXPACKET,
18165 		("%s: len > IP_MAXPACKET", __func__));
18166 #ifdef DIAGNOSTIC
18167 #ifdef INET6
18168 	if (max_linkhdr + hdrlen > MCLBYTES)
18169 #else
18170 		if (max_linkhdr + hdrlen > MHLEN)
18171 #endif
18172 			panic("tcphdr too big");
18173 #endif
18174 
18175 	/*
18176 	 * This KASSERT is here to catch edge cases at a well defined place.
18177 	 * Before, those had triggered (random) panic conditions further
18178 	 * down.
18179 	 */
18180 	KASSERT(len >= 0, ("[%s:%d]: len < 0", __func__, __LINE__));
18181 	if ((len == 0) &&
18182 	    (flags & TH_FIN) &&
18183 	    (sbused(sb))) {
18184 		/*
18185 		 * We have outstanding data, don't send a fin by itself!.
18186 		 */
18187 		goto just_return;
18188 	}
18189 	/*
18190 	 * Grab a header mbuf, attaching a copy of data to be transmitted,
18191 	 * and initialize the header from the template for sends on this
18192 	 * connection.
18193 	 */
18194 	hw_tls = (sb->sb_flags & SB_TLS_IFNET) != 0;
18195 	if (len) {
18196 		uint32_t max_val;
18197 		uint32_t moff;
18198 
18199 		if (rack->r_ctl.rc_pace_max_segs)
18200 			max_val = rack->r_ctl.rc_pace_max_segs;
18201 		else if (rack->rc_user_set_max_segs)
18202 			max_val = rack->rc_user_set_max_segs * segsiz;
18203 		else
18204 			max_val = len;
18205 		/*
18206 		 * We allow a limit on sending with hptsi.
18207 		 */
18208 		if (len > max_val) {
18209 			mark = 7;
18210 			len = max_val;
18211 		}
18212 #ifdef INET6
18213 		if (MHLEN < hdrlen + max_linkhdr)
18214 			m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR);
18215 		else
18216 #endif
18217 			m = m_gethdr(M_NOWAIT, MT_DATA);
18218 
18219 		if (m == NULL) {
18220 			SOCKBUF_UNLOCK(sb);
18221 			error = ENOBUFS;
18222 			sack_rxmit = 0;
18223 			goto out;
18224 		}
18225 		m->m_data += max_linkhdr;
18226 		m->m_len = hdrlen;
18227 
18228 		/*
18229 		 * Start the m_copy functions from the closest mbuf to the
18230 		 * sb_offset in the socket buffer chain.
18231 		 */
18232 		mb = sbsndptr_noadv(sb, sb_offset, &moff);
18233 		s_mb = mb;
18234 		s_moff = moff;
18235 		if (len <= MHLEN - hdrlen - max_linkhdr && !hw_tls) {
18236 			m_copydata(mb, moff, (int)len,
18237 				   mtod(m, caddr_t)+hdrlen);
18238 			if (SEQ_LT(tp->snd_nxt, tp->snd_max))
18239 				sbsndptr_adv(sb, mb, len);
18240 			m->m_len += len;
18241 		} else {
18242 			struct sockbuf *msb;
18243 
18244 			if (SEQ_LT(tp->snd_nxt, tp->snd_max))
18245 				msb = NULL;
18246 			else
18247 				msb = sb;
18248 			m->m_next = tcp_m_copym(
18249 				mb, moff, &len,
18250 				if_hw_tsomaxsegcount, if_hw_tsomaxsegsize, msb,
18251 				((rsm == NULL) ? hw_tls : 0)
18252 #ifdef NETFLIX_COPY_ARGS
18253 				, &filled_all
18254 #endif
18255 				);
18256 			if (len <= (tp->t_maxseg - optlen)) {
18257 				/*
18258 				 * Must have ran out of mbufs for the copy
18259 				 * shorten it to no longer need tso. Lets
18260 				 * not put on sendalot since we are low on
18261 				 * mbufs.
18262 				 */
18263 				tso = 0;
18264 			}
18265 			if (m->m_next == NULL) {
18266 				SOCKBUF_UNLOCK(sb);
18267 				(void)m_free(m);
18268 				error = ENOBUFS;
18269 				sack_rxmit = 0;
18270 				goto out;
18271 			}
18272 		}
18273 		if (SEQ_LT(tp->snd_nxt, tp->snd_max) || sack_rxmit) {
18274 			if (rsm && (rsm->r_flags & RACK_TLP)) {
18275 				/*
18276 				 * TLP should not count in retran count, but
18277 				 * in its own bin
18278 				 */
18279 				counter_u64_add(rack_tlp_retran, 1);
18280 				counter_u64_add(rack_tlp_retran_bytes, len);
18281 			} else {
18282 				tp->t_sndrexmitpack++;
18283 				KMOD_TCPSTAT_INC(tcps_sndrexmitpack);
18284 				KMOD_TCPSTAT_ADD(tcps_sndrexmitbyte, len);
18285 			}
18286 #ifdef STATS
18287 			stats_voi_update_abs_u32(tp->t_stats, VOI_TCP_RETXPB,
18288 						 len);
18289 #endif
18290 		} else {
18291 			KMOD_TCPSTAT_INC(tcps_sndpack);
18292 			KMOD_TCPSTAT_ADD(tcps_sndbyte, len);
18293 #ifdef STATS
18294 			stats_voi_update_abs_u64(tp->t_stats, VOI_TCP_TXPB,
18295 						 len);
18296 #endif
18297 		}
18298 		/*
18299 		 * If we're sending everything we've got, set PUSH. (This
18300 		 * will keep happy those implementations which only give
18301 		 * data to the user when a buffer fills or a PUSH comes in.)
18302 		 */
18303 		if (sb_offset + len == sbused(sb) &&
18304 		    sbused(sb) &&
18305 		    !(flags & TH_SYN)) {
18306 			flags |= TH_PUSH;
18307 			add_flag |= RACK_HAD_PUSH;
18308 		}
18309 
18310 		SOCKBUF_UNLOCK(sb);
18311 	} else {
18312 		SOCKBUF_UNLOCK(sb);
18313 		if (tp->t_flags & TF_ACKNOW)
18314 			KMOD_TCPSTAT_INC(tcps_sndacks);
18315 		else if (flags & (TH_SYN | TH_FIN | TH_RST))
18316 			KMOD_TCPSTAT_INC(tcps_sndctrl);
18317 		else
18318 			KMOD_TCPSTAT_INC(tcps_sndwinup);
18319 
18320 		m = m_gethdr(M_NOWAIT, MT_DATA);
18321 		if (m == NULL) {
18322 			error = ENOBUFS;
18323 			sack_rxmit = 0;
18324 			goto out;
18325 		}
18326 #ifdef INET6
18327 		if (isipv6 && (MHLEN < hdrlen + max_linkhdr) &&
18328 		    MHLEN >= hdrlen) {
18329 			M_ALIGN(m, hdrlen);
18330 		} else
18331 #endif
18332 			m->m_data += max_linkhdr;
18333 		m->m_len = hdrlen;
18334 	}
18335 	SOCKBUF_UNLOCK_ASSERT(sb);
18336 	m->m_pkthdr.rcvif = (struct ifnet *)0;
18337 #ifdef MAC
18338 	mac_inpcb_create_mbuf(inp, m);
18339 #endif
18340 	if ((ipoptlen == 0) && (rack->r_ctl.fsb.tcp_ip_hdr) &&  rack->r_fsb_inited) {
18341 #ifdef INET6
18342 		if (isipv6)
18343 			ip6 = (struct ip6_hdr *)rack->r_ctl.fsb.tcp_ip_hdr;
18344 		else
18345 #endif				/* INET6 */
18346 			ip = (struct ip *)rack->r_ctl.fsb.tcp_ip_hdr;
18347 		th = rack->r_ctl.fsb.th;
18348 		udp = rack->r_ctl.fsb.udp;
18349 		if (udp) {
18350 #ifdef INET6
18351 			if (isipv6)
18352 				ulen = hdrlen + len - sizeof(struct ip6_hdr);
18353 			else
18354 #endif				/* INET6 */
18355 				ulen = hdrlen + len - sizeof(struct ip);
18356 			udp->uh_ulen = htons(ulen);
18357 		}
18358 	} else {
18359 #ifdef INET6
18360 		if (isipv6) {
18361 			ip6 = mtod(m, struct ip6_hdr *);
18362 			if (tp->t_port) {
18363 				udp = (struct udphdr *)((caddr_t)ip6 + sizeof(struct ip6_hdr));
18364 				udp->uh_sport = htons(V_tcp_udp_tunneling_port);
18365 				udp->uh_dport = tp->t_port;
18366 				ulen = hdrlen + len - sizeof(struct ip6_hdr);
18367 				udp->uh_ulen = htons(ulen);
18368 				th = (struct tcphdr *)(udp + 1);
18369 			} else
18370 				th = (struct tcphdr *)(ip6 + 1);
18371 			tcpip_fillheaders(inp, tp->t_port, ip6, th);
18372 		} else
18373 #endif				/* INET6 */
18374 		{
18375 			ip = mtod(m, struct ip *);
18376 #ifdef TCPDEBUG
18377 			ipov = (struct ipovly *)ip;
18378 #endif
18379 			if (tp->t_port) {
18380 				udp = (struct udphdr *)((caddr_t)ip + sizeof(struct ip));
18381 				udp->uh_sport = htons(V_tcp_udp_tunneling_port);
18382 				udp->uh_dport = tp->t_port;
18383 				ulen = hdrlen + len - sizeof(struct ip);
18384 				udp->uh_ulen = htons(ulen);
18385 				th = (struct tcphdr *)(udp + 1);
18386 			} else
18387 				th = (struct tcphdr *)(ip + 1);
18388 			tcpip_fillheaders(inp, tp->t_port, ip, th);
18389 		}
18390 	}
18391 	/*
18392 	 * Fill in fields, remembering maximum advertised window for use in
18393 	 * delaying messages about window sizes. If resending a FIN, be sure
18394 	 * not to use a new sequence number.
18395 	 */
18396 	if (flags & TH_FIN && tp->t_flags & TF_SENTFIN &&
18397 	    tp->snd_nxt == tp->snd_max)
18398 		tp->snd_nxt--;
18399 	/*
18400 	 * If we are starting a connection, send ECN setup SYN packet. If we
18401 	 * are on a retransmit, we may resend those bits a number of times
18402 	 * as per RFC 3168.
18403 	 */
18404 	if (tp->t_state == TCPS_SYN_SENT && V_tcp_do_ecn == 1) {
18405 		if (tp->t_rxtshift >= 1) {
18406 			if (tp->t_rxtshift <= V_tcp_ecn_maxretries)
18407 				flags |= TH_ECE | TH_CWR;
18408 		} else
18409 			flags |= TH_ECE | TH_CWR;
18410 	}
18411 	/* Handle parallel SYN for ECN */
18412 	if ((tp->t_state == TCPS_SYN_RECEIVED) &&
18413 	    (tp->t_flags2 & TF2_ECN_SND_ECE)) {
18414 		flags |= TH_ECE;
18415 		tp->t_flags2 &= ~TF2_ECN_SND_ECE;
18416 	}
18417 	if (TCPS_HAVEESTABLISHED(tp->t_state) &&
18418 	    (tp->t_flags2 & TF2_ECN_PERMIT)) {
18419 		/*
18420 		 * If the peer has ECN, mark data packets with ECN capable
18421 		 * transmission (ECT). Ignore pure ack packets,
18422 		 * retransmissions.
18423 		 */
18424 		if (len > 0 && SEQ_GEQ(tp->snd_nxt, tp->snd_max) &&
18425 		    (sack_rxmit == 0)) {
18426 #ifdef INET6
18427 			if (isipv6)
18428 				ip6->ip6_flow |= htonl(IPTOS_ECN_ECT0 << 20);
18429 			else
18430 #endif
18431 				ip->ip_tos |= IPTOS_ECN_ECT0;
18432 			KMOD_TCPSTAT_INC(tcps_ecn_ect0);
18433 			/*
18434 			 * Reply with proper ECN notifications.
18435 			 * Only set CWR on new data segments.
18436 			 */
18437 			if (tp->t_flags2 & TF2_ECN_SND_CWR) {
18438 				flags |= TH_CWR;
18439 				tp->t_flags2 &= ~TF2_ECN_SND_CWR;
18440 			}
18441 		}
18442 		if (tp->t_flags2 & TF2_ECN_SND_ECE)
18443 			flags |= TH_ECE;
18444 	}
18445 	/*
18446 	 * If we are doing retransmissions, then snd_nxt will not reflect
18447 	 * the first unsent octet.  For ACK only packets, we do not want the
18448 	 * sequence number of the retransmitted packet, we want the sequence
18449 	 * number of the next unsent octet.  So, if there is no data (and no
18450 	 * SYN or FIN), use snd_max instead of snd_nxt when filling in
18451 	 * ti_seq.  But if we are in persist state, snd_max might reflect
18452 	 * one byte beyond the right edge of the window, so use snd_nxt in
18453 	 * that case, since we know we aren't doing a retransmission.
18454 	 * (retransmit and persist are mutually exclusive...)
18455 	 */
18456 	if (sack_rxmit == 0) {
18457 		if (len || (flags & (TH_SYN | TH_FIN))) {
18458 			th->th_seq = htonl(tp->snd_nxt);
18459 			rack_seq = tp->snd_nxt;
18460 		} else {
18461 			th->th_seq = htonl(tp->snd_max);
18462 			rack_seq = tp->snd_max;
18463 		}
18464 	} else {
18465 		th->th_seq = htonl(rsm->r_start);
18466 		rack_seq = rsm->r_start;
18467 	}
18468 	th->th_ack = htonl(tp->rcv_nxt);
18469 	th->th_flags = flags;
18470 	/*
18471 	 * Calculate receive window.  Don't shrink window, but avoid silly
18472 	 * window syndrome.
18473 	 * If a RST segment is sent, advertise a window of zero.
18474 	 */
18475 	if (flags & TH_RST) {
18476 		recwin = 0;
18477 	} else {
18478 		if (recwin < (long)(so->so_rcv.sb_hiwat / 4) &&
18479 		    recwin < (long)segsiz) {
18480 			recwin = 0;
18481 		}
18482 		if (SEQ_GT(tp->rcv_adv, tp->rcv_nxt) &&
18483 		    recwin < (long)(tp->rcv_adv - tp->rcv_nxt))
18484 			recwin = (long)(tp->rcv_adv - tp->rcv_nxt);
18485 	}
18486 
18487 	/*
18488 	 * According to RFC1323 the window field in a SYN (i.e., a <SYN> or
18489 	 * <SYN,ACK>) segment itself is never scaled.  The <SYN,ACK> case is
18490 	 * handled in syncache.
18491 	 */
18492 	if (flags & TH_SYN)
18493 		th->th_win = htons((u_short)
18494 				   (min(sbspace(&so->so_rcv), TCP_MAXWIN)));
18495 	else {
18496 		/* Avoid shrinking window with window scaling. */
18497 		recwin = roundup2(recwin, 1 << tp->rcv_scale);
18498 		th->th_win = htons((u_short)(recwin >> tp->rcv_scale));
18499 	}
18500 	/*
18501 	 * Adjust the RXWIN0SENT flag - indicate that we have advertised a 0
18502 	 * window.  This may cause the remote transmitter to stall.  This
18503 	 * flag tells soreceive() to disable delayed acknowledgements when
18504 	 * draining the buffer.  This can occur if the receiver is
18505 	 * attempting to read more data than can be buffered prior to
18506 	 * transmitting on the connection.
18507 	 */
18508 	if (th->th_win == 0) {
18509 		tp->t_sndzerowin++;
18510 		tp->t_flags |= TF_RXWIN0SENT;
18511 	} else
18512 		tp->t_flags &= ~TF_RXWIN0SENT;
18513 	tp->snd_up = tp->snd_una;	/* drag it along, its deprecated */
18514 	/* Now are we using fsb?, if so copy the template data to the mbuf */
18515 	if ((ipoptlen == 0) && (rack->r_ctl.fsb.tcp_ip_hdr) && rack->r_fsb_inited) {
18516 		uint8_t *cpto;
18517 
18518 		cpto = mtod(m, uint8_t *);
18519 		memcpy(cpto, rack->r_ctl.fsb.tcp_ip_hdr, rack->r_ctl.fsb.tcp_ip_hdr_len);
18520 		/*
18521 		 * We have just copied in:
18522 		 * IP/IP6
18523 		 * <optional udphdr>
18524 		 * tcphdr (no options)
18525 		 *
18526 		 * We need to grab the correct pointers into the mbuf
18527 		 * for both the tcp header, and possibly the udp header (if tunneling).
18528 		 * We do this by using the offset in the copy buffer and adding it
18529 		 * to the mbuf base pointer (cpto).
18530 		 */
18531 #ifdef INET6
18532 		if (isipv6)
18533 			ip6 = mtod(m, struct ip6_hdr *);
18534 		else
18535 #endif				/* INET6 */
18536 			ip = mtod(m, struct ip *);
18537 		th = (struct tcphdr *)(cpto + ((uint8_t *)rack->r_ctl.fsb.th - rack->r_ctl.fsb.tcp_ip_hdr));
18538 		/* If we have a udp header lets set it into the mbuf as well */
18539 		if (udp)
18540 			udp = (struct udphdr *)(cpto + ((uint8_t *)rack->r_ctl.fsb.udp - rack->r_ctl.fsb.tcp_ip_hdr));
18541 	}
18542 #if defined(IPSEC_SUPPORT) || defined(TCP_SIGNATURE)
18543 	if (to.to_flags & TOF_SIGNATURE) {
18544 		/*
18545 		 * Calculate MD5 signature and put it into the place
18546 		 * determined before.
18547 		 * NOTE: since TCP options buffer doesn't point into
18548 		 * mbuf's data, calculate offset and use it.
18549 		 */
18550 		if (!TCPMD5_ENABLED() || TCPMD5_OUTPUT(m, th,
18551 						       (u_char *)(th + 1) + (to.to_signature - opt)) != 0) {
18552 			/*
18553 			 * Do not send segment if the calculation of MD5
18554 			 * digest has failed.
18555 			 */
18556 			goto out;
18557 		}
18558 	}
18559 #endif
18560 	if (optlen) {
18561 		bcopy(opt, th + 1, optlen);
18562 		th->th_off = (sizeof(struct tcphdr) + optlen) >> 2;
18563 	}
18564 	/*
18565 	 * Put TCP length in extended header, and then checksum extended
18566 	 * header and data.
18567 	 */
18568 	m->m_pkthdr.len = hdrlen + len;	/* in6_cksum() need this */
18569 #ifdef INET6
18570 	if (isipv6) {
18571 		/*
18572 		 * ip6_plen is not need to be filled now, and will be filled
18573 		 * in ip6_output.
18574 		 */
18575 		if (tp->t_port) {
18576 			m->m_pkthdr.csum_flags = CSUM_UDP_IPV6;
18577 			m->m_pkthdr.csum_data = offsetof(struct udphdr, uh_sum);
18578 			udp->uh_sum = in6_cksum_pseudo(ip6, ulen, IPPROTO_UDP, 0);
18579 			th->th_sum = htons(0);
18580 			UDPSTAT_INC(udps_opackets);
18581 		} else {
18582 			m->m_pkthdr.csum_flags = CSUM_TCP_IPV6;
18583 			m->m_pkthdr.csum_data = offsetof(struct tcphdr, th_sum);
18584 			th->th_sum = in6_cksum_pseudo(ip6,
18585 						      sizeof(struct tcphdr) + optlen + len, IPPROTO_TCP,
18586 						      0);
18587 		}
18588 	}
18589 #endif
18590 #if defined(INET6) && defined(INET)
18591 	else
18592 #endif
18593 #ifdef INET
18594 	{
18595 		if (tp->t_port) {
18596 			m->m_pkthdr.csum_flags = CSUM_UDP;
18597 			m->m_pkthdr.csum_data = offsetof(struct udphdr, uh_sum);
18598 			udp->uh_sum = in_pseudo(ip->ip_src.s_addr,
18599 						ip->ip_dst.s_addr, htons(ulen + IPPROTO_UDP));
18600 			th->th_sum = htons(0);
18601 			UDPSTAT_INC(udps_opackets);
18602 		} else {
18603 			m->m_pkthdr.csum_flags = CSUM_TCP;
18604 			m->m_pkthdr.csum_data = offsetof(struct tcphdr, th_sum);
18605 			th->th_sum = in_pseudo(ip->ip_src.s_addr,
18606 					       ip->ip_dst.s_addr, htons(sizeof(struct tcphdr) +
18607 									IPPROTO_TCP + len + optlen));
18608 		}
18609 		/* IP version must be set here for ipv4/ipv6 checking later */
18610 		KASSERT(ip->ip_v == IPVERSION,
18611 			("%s: IP version incorrect: %d", __func__, ip->ip_v));
18612 	}
18613 #endif
18614 	/*
18615 	 * Enable TSO and specify the size of the segments. The TCP pseudo
18616 	 * header checksum is always provided. XXX: Fixme: This is currently
18617 	 * not the case for IPv6.
18618 	 */
18619 	if (tso) {
18620 		KASSERT(len > tp->t_maxseg - optlen,
18621 			("%s: len <= tso_segsz", __func__));
18622 		m->m_pkthdr.csum_flags |= CSUM_TSO;
18623 		m->m_pkthdr.tso_segsz = tp->t_maxseg - optlen;
18624 	}
18625 	KASSERT(len + hdrlen == m_length(m, NULL),
18626 		("%s: mbuf chain different than expected: %d + %u != %u",
18627 		 __func__, len, hdrlen, m_length(m, NULL)));
18628 
18629 #ifdef TCP_HHOOK
18630 	/* Run HHOOK_TCP_ESTABLISHED_OUT helper hooks. */
18631 	hhook_run_tcp_est_out(tp, th, &to, len, tso);
18632 #endif
18633 	/* We're getting ready to send; log now. */
18634 	if (tp->t_logstate != TCP_LOG_STATE_OFF) {
18635 		union tcp_log_stackspecific log;
18636 
18637 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
18638 		log.u_bbr.inhpts = rack->rc_inp->inp_in_hpts;
18639 		log.u_bbr.ininput = rack->rc_inp->inp_in_input;
18640 		if (rack->rack_no_prr)
18641 			log.u_bbr.flex1 = 0;
18642 		else
18643 			log.u_bbr.flex1 = rack->r_ctl.rc_prr_sndcnt;
18644 		log.u_bbr.flex2 = rack->r_ctl.rc_pace_min_segs;
18645 		log.u_bbr.flex3 = rack->r_ctl.rc_pace_max_segs;
18646 		log.u_bbr.flex4 = orig_len;
18647 		if (filled_all)
18648 			log.u_bbr.flex5 = 0x80000000;
18649 		else
18650 			log.u_bbr.flex5 = 0;
18651 		/* Save off the early/late values */
18652 		log.u_bbr.flex6 = rack->r_ctl.rc_agg_early;
18653 		log.u_bbr.applimited = rack->r_ctl.rc_agg_delayed;
18654 		log.u_bbr.bw_inuse = rack_get_bw(rack);
18655 		if (rsm || sack_rxmit) {
18656 			if (doing_tlp)
18657 				log.u_bbr.flex8 = 2;
18658 			else
18659 				log.u_bbr.flex8 = 1;
18660 		} else {
18661 			if (doing_tlp)
18662 				log.u_bbr.flex8 = 3;
18663 			else
18664 				log.u_bbr.flex8 = 0;
18665 		}
18666 		log.u_bbr.pacing_gain = rack_get_output_gain(rack, rsm);
18667 		log.u_bbr.flex7 = mark;
18668 		log.u_bbr.flex7 <<= 8;
18669 		log.u_bbr.flex7 |= pass;
18670 		log.u_bbr.pkts_out = tp->t_maxseg;
18671 		log.u_bbr.timeStamp = cts;
18672 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
18673 		log.u_bbr.lt_epoch = cwnd_to_use;
18674 		log.u_bbr.delivered = sendalot;
18675 		lgb = tcp_log_event_(tp, th, &so->so_rcv, &so->so_snd, TCP_LOG_OUT, ERRNO_UNK,
18676 				     len, &log, false, NULL, NULL, 0, &tv);
18677 	} else
18678 		lgb = NULL;
18679 
18680 	/*
18681 	 * Fill in IP length and desired time to live and send to IP level.
18682 	 * There should be a better way to handle ttl and tos; we could keep
18683 	 * them in the template, but need a way to checksum without them.
18684 	 */
18685 	/*
18686 	 * m->m_pkthdr.len should have been set before cksum calcuration,
18687 	 * because in6_cksum() need it.
18688 	 */
18689 #ifdef INET6
18690 	if (isipv6) {
18691 		/*
18692 		 * we separately set hoplimit for every segment, since the
18693 		 * user might want to change the value via setsockopt. Also,
18694 		 * desired default hop limit might be changed via Neighbor
18695 		 * Discovery.
18696 		 */
18697 		rack->r_ctl.fsb.hoplimit = ip6->ip6_hlim = in6_selecthlim(inp, NULL);
18698 
18699 		/*
18700 		 * Set the packet size here for the benefit of DTrace
18701 		 * probes. ip6_output() will set it properly; it's supposed
18702 		 * to include the option header lengths as well.
18703 		 */
18704 		ip6->ip6_plen = htons(m->m_pkthdr.len - sizeof(*ip6));
18705 
18706 		if (V_path_mtu_discovery && tp->t_maxseg > V_tcp_minmss)
18707 			tp->t_flags2 |= TF2_PLPMTU_PMTUD;
18708 		else
18709 			tp->t_flags2 &= ~TF2_PLPMTU_PMTUD;
18710 
18711 		if (tp->t_state == TCPS_SYN_SENT)
18712 			TCP_PROBE5(connect__request, NULL, tp, ip6, tp, th);
18713 
18714 		TCP_PROBE5(send, NULL, tp, ip6, tp, th);
18715 		/* TODO: IPv6 IP6TOS_ECT bit on */
18716 		error = ip6_output(m,
18717 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
18718 				   inp->in6p_outputopts,
18719 #else
18720 				   NULL,
18721 #endif
18722 				   &inp->inp_route6,
18723 				   ((rsm || sack_rxmit) ? IP_NO_SND_TAG_RL : 0),
18724 				   NULL, NULL, inp);
18725 
18726 		if (error == EMSGSIZE && inp->inp_route6.ro_nh != NULL)
18727 			mtu = inp->inp_route6.ro_nh->nh_mtu;
18728 	}
18729 #endif				/* INET6 */
18730 #if defined(INET) && defined(INET6)
18731 	else
18732 #endif
18733 #ifdef INET
18734 	{
18735 		ip->ip_len = htons(m->m_pkthdr.len);
18736 #ifdef INET6
18737 		if (inp->inp_vflag & INP_IPV6PROTO)
18738 			ip->ip_ttl = in6_selecthlim(inp, NULL);
18739 #endif				/* INET6 */
18740 		rack->r_ctl.fsb.hoplimit = ip->ip_ttl;
18741 		/*
18742 		 * If we do path MTU discovery, then we set DF on every
18743 		 * packet. This might not be the best thing to do according
18744 		 * to RFC3390 Section 2. However the tcp hostcache migitates
18745 		 * the problem so it affects only the first tcp connection
18746 		 * with a host.
18747 		 *
18748 		 * NB: Don't set DF on small MTU/MSS to have a safe
18749 		 * fallback.
18750 		 */
18751 		if (V_path_mtu_discovery && tp->t_maxseg > V_tcp_minmss) {
18752 			tp->t_flags2 |= TF2_PLPMTU_PMTUD;
18753 			if (tp->t_port == 0 || len < V_tcp_minmss) {
18754 				ip->ip_off |= htons(IP_DF);
18755 			}
18756 		} else {
18757 			tp->t_flags2 &= ~TF2_PLPMTU_PMTUD;
18758 		}
18759 
18760 		if (tp->t_state == TCPS_SYN_SENT)
18761 			TCP_PROBE5(connect__request, NULL, tp, ip, tp, th);
18762 
18763 		TCP_PROBE5(send, NULL, tp, ip, tp, th);
18764 
18765 		error = ip_output(m,
18766 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
18767 				  inp->inp_options,
18768 #else
18769 				  NULL,
18770 #endif
18771 				  &inp->inp_route,
18772 				  ((rsm || sack_rxmit) ? IP_NO_SND_TAG_RL : 0), 0,
18773 				  inp);
18774 		if (error == EMSGSIZE && inp->inp_route.ro_nh != NULL)
18775 			mtu = inp->inp_route.ro_nh->nh_mtu;
18776 	}
18777 #endif				/* INET */
18778 
18779 out:
18780 	if (lgb) {
18781 		lgb->tlb_errno = error;
18782 		lgb = NULL;
18783 	}
18784 	/*
18785 	 * In transmit state, time the transmission and arrange for the
18786 	 * retransmit.  In persist state, just set snd_max.
18787 	 */
18788 	if (error == 0) {
18789 		tcp_account_for_send(tp, len, (rsm != NULL), doing_tlp, hw_tls);
18790 		if (rsm && doing_tlp) {
18791 			rack->rc_last_sent_tlp_past_cumack = 0;
18792 			rack->rc_last_sent_tlp_seq_valid = 1;
18793 			rack->r_ctl.last_sent_tlp_seq = rsm->r_start;
18794 			rack->r_ctl.last_sent_tlp_len = rsm->r_end - rsm->r_start;
18795 		}
18796 		rack->forced_ack = 0;	/* If we send something zap the FA flag */
18797 		if (rsm && (doing_tlp == 0)) {
18798 			/* Set we retransmitted */
18799 			rack->rc_gp_saw_rec = 1;
18800 		} else {
18801 			if (cwnd_to_use > tp->snd_ssthresh) {
18802 				/* Set we sent in CA */
18803 				rack->rc_gp_saw_ca = 1;
18804 			} else {
18805 				/* Set we sent in SS */
18806 				rack->rc_gp_saw_ss = 1;
18807 			}
18808 		}
18809 		if (doing_tlp && (rsm == NULL)) {
18810 			/* Make sure new data TLP cnt is clear */
18811 			rack->r_ctl.rc_tlp_new_data = 0;
18812 		}
18813 		if (TCPS_HAVEESTABLISHED(tp->t_state) &&
18814 		    (tp->t_flags & TF_SACK_PERMIT) &&
18815 		    tp->rcv_numsacks > 0)
18816 			tcp_clean_dsack_blocks(tp);
18817 		tot_len_this_send += len;
18818 		if (len == 0)
18819 			counter_u64_add(rack_out_size[TCP_MSS_ACCT_SNDACK], 1);
18820 		else if (len == 1) {
18821 			counter_u64_add(rack_out_size[TCP_MSS_ACCT_PERSIST], 1);
18822 		} else if (len > 1) {
18823 			int idx;
18824 
18825 			idx = (len / segsiz) + 3;
18826 			if (idx >= TCP_MSS_ACCT_ATIMER)
18827 				counter_u64_add(rack_out_size[(TCP_MSS_ACCT_ATIMER-1)], 1);
18828 			else
18829 				counter_u64_add(rack_out_size[idx], 1);
18830 		}
18831 	}
18832 	if ((rack->rack_no_prr == 0) &&
18833 	    sub_from_prr &&
18834 	    (error == 0)) {
18835 		if (rack->r_ctl.rc_prr_sndcnt >= len)
18836 			rack->r_ctl.rc_prr_sndcnt -= len;
18837 		else
18838 			rack->r_ctl.rc_prr_sndcnt = 0;
18839 	}
18840 	sub_from_prr = 0;
18841 	if (doing_tlp) {
18842 		/* Make sure the TLP is added */
18843 		add_flag |= RACK_TLP;
18844 	} else if (rsm) {
18845 		/* If its a resend without TLP then it must not have the flag */
18846 		rsm->r_flags &= ~RACK_TLP;
18847 	}
18848 	rack_log_output(tp, &to, len, rack_seq, (uint8_t) flags, error,
18849 			rack_to_usec_ts(&tv),
18850 			rsm, add_flag, s_mb, s_moff, hw_tls);
18851 
18852 
18853 	if ((error == 0) &&
18854 	    (len > 0) &&
18855 	    (tp->snd_una == tp->snd_max))
18856 		rack->r_ctl.rc_tlp_rxt_last_time = cts;
18857 	{
18858 		tcp_seq startseq = tp->snd_nxt;
18859 
18860 		/* Track our lost count */
18861 		if (rsm && (doing_tlp == 0))
18862 			rack->r_ctl.rc_loss_count += rsm->r_end - rsm->r_start;
18863 		/*
18864 		 * Advance snd_nxt over sequence space of this segment.
18865 		 */
18866 		if (error)
18867 			/* We don't log or do anything with errors */
18868 			goto nomore;
18869 		if (doing_tlp == 0) {
18870 			if (rsm == NULL) {
18871 				/*
18872 				 * Not a retransmission of some
18873 				 * sort, new data is going out so
18874 				 * clear our TLP count and flag.
18875 				 */
18876 				rack->rc_tlp_in_progress = 0;
18877 				rack->r_ctl.rc_tlp_cnt_out = 0;
18878 			}
18879 		} else {
18880 			/*
18881 			 * We have just sent a TLP, mark that it is true
18882 			 * and make sure our in progress is set so we
18883 			 * continue to check the count.
18884 			 */
18885 			rack->rc_tlp_in_progress = 1;
18886 			rack->r_ctl.rc_tlp_cnt_out++;
18887 		}
18888 		if (flags & (TH_SYN | TH_FIN)) {
18889 			if (flags & TH_SYN)
18890 				tp->snd_nxt++;
18891 			if (flags & TH_FIN) {
18892 				tp->snd_nxt++;
18893 				tp->t_flags |= TF_SENTFIN;
18894 			}
18895 		}
18896 		/* In the ENOBUFS case we do *not* update snd_max */
18897 		if (sack_rxmit)
18898 			goto nomore;
18899 
18900 		tp->snd_nxt += len;
18901 		if (SEQ_GT(tp->snd_nxt, tp->snd_max)) {
18902 			if (tp->snd_una == tp->snd_max) {
18903 				/*
18904 				 * Update the time we just added data since
18905 				 * none was outstanding.
18906 				 */
18907 				rack_log_progress_event(rack, tp, ticks, PROGRESS_START, __LINE__);
18908 				tp->t_acktime = ticks;
18909 			}
18910 			tp->snd_max = tp->snd_nxt;
18911 			/*
18912 			 * Time this transmission if not a retransmission and
18913 			 * not currently timing anything.
18914 			 * This is only relevant in case of switching back to
18915 			 * the base stack.
18916 			 */
18917 			if (tp->t_rtttime == 0) {
18918 				tp->t_rtttime = ticks;
18919 				tp->t_rtseq = startseq;
18920 				KMOD_TCPSTAT_INC(tcps_segstimed);
18921 			}
18922 			if (len &&
18923 			    ((tp->t_flags & TF_GPUTINPROG) == 0))
18924 				rack_start_gp_measurement(tp, rack, startseq, sb_offset);
18925 		}
18926 		/*
18927 		 * If we are doing FO we need to update the mbuf position and subtract
18928 		 * this happens when the peer sends us duplicate information and
18929 		 * we thus want to send a DSACK.
18930 		 *
18931 		 * XXXRRS: This brings to mind a ?, when we send a DSACK block is TSO
18932 		 * turned off? If not then we are going to echo multiple DSACK blocks
18933 		 * out (with the TSO), which we should not be doing.
18934 		 */
18935 		if (rack->r_fast_output && len) {
18936 			if (rack->r_ctl.fsb.left_to_send > len)
18937 				rack->r_ctl.fsb.left_to_send -= len;
18938 			else
18939 				rack->r_ctl.fsb.left_to_send = 0;
18940 			if (rack->r_ctl.fsb.left_to_send < segsiz)
18941 				rack->r_fast_output = 0;
18942 			if (rack->r_fast_output) {
18943 				rack->r_ctl.fsb.m = sbsndmbuf(sb, (tp->snd_max - tp->snd_una), &rack->r_ctl.fsb.off);
18944 				rack->r_ctl.fsb.o_m_len = rack->r_ctl.fsb.m->m_len;
18945 			}
18946 		}
18947 	}
18948 nomore:
18949 	if (error) {
18950 		rack->r_ctl.rc_agg_delayed = 0;
18951 		rack->r_early = 0;
18952 		rack->r_late = 0;
18953 		rack->r_ctl.rc_agg_early = 0;
18954 		SOCKBUF_UNLOCK_ASSERT(sb);	/* Check gotos. */
18955 		/*
18956 		 * Failures do not advance the seq counter above. For the
18957 		 * case of ENOBUFS we will fall out and retry in 1ms with
18958 		 * the hpts. Everything else will just have to retransmit
18959 		 * with the timer.
18960 		 *
18961 		 * In any case, we do not want to loop around for another
18962 		 * send without a good reason.
18963 		 */
18964 		sendalot = 0;
18965 		switch (error) {
18966 		case EPERM:
18967 			tp->t_softerror = error;
18968 #ifdef TCP_ACCOUNTING
18969 			crtsc = get_cyclecount();
18970 			if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
18971 				tp->tcp_cnt_counters[SND_OUT_FAIL]++;
18972 			}
18973 			counter_u64_add(tcp_cnt_counters[SND_OUT_FAIL], 1);
18974 			if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
18975 				tp->tcp_proc_time[SND_OUT_FAIL] += (crtsc - ts_val);
18976 			}
18977 			counter_u64_add(tcp_proc_time[SND_OUT_FAIL], (crtsc - ts_val));
18978 			sched_unpin();
18979 #endif
18980 			return (error);
18981 		case ENOBUFS:
18982 			/*
18983 			 * Pace us right away to retry in a some
18984 			 * time
18985 			 */
18986 			slot = ((1 + rack->rc_enobuf) * HPTS_USEC_IN_MSEC);
18987 			if (rack->rc_enobuf < 0x7f)
18988 				rack->rc_enobuf++;
18989 			if (slot < (10 * HPTS_USEC_IN_MSEC))
18990 				slot = 10 * HPTS_USEC_IN_MSEC;
18991 			if (rack->r_ctl.crte != NULL) {
18992 				counter_u64_add(rack_saw_enobuf_hw, 1);
18993 				tcp_rl_log_enobuf(rack->r_ctl.crte);
18994 			}
18995 			counter_u64_add(rack_saw_enobuf, 1);
18996 			goto enobufs;
18997 		case EMSGSIZE:
18998 			/*
18999 			 * For some reason the interface we used initially
19000 			 * to send segments changed to another or lowered
19001 			 * its MTU. If TSO was active we either got an
19002 			 * interface without TSO capabilits or TSO was
19003 			 * turned off. If we obtained mtu from ip_output()
19004 			 * then update it and try again.
19005 			 */
19006 			if (tso)
19007 				tp->t_flags &= ~TF_TSO;
19008 			if (mtu != 0) {
19009 				tcp_mss_update(tp, -1, mtu, NULL, NULL);
19010 				goto again;
19011 			}
19012 			slot = 10 * HPTS_USEC_IN_MSEC;
19013 			rack_start_hpts_timer(rack, tp, cts, slot, 0, 0);
19014 #ifdef TCP_ACCOUNTING
19015 			crtsc = get_cyclecount();
19016 			if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
19017 				tp->tcp_cnt_counters[SND_OUT_FAIL]++;
19018 			}
19019 			counter_u64_add(tcp_cnt_counters[SND_OUT_FAIL], 1);
19020 			if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
19021 				tp->tcp_proc_time[SND_OUT_FAIL] += (crtsc - ts_val);
19022 			}
19023 			counter_u64_add(tcp_proc_time[SND_OUT_FAIL], (crtsc - ts_val));
19024 			sched_unpin();
19025 #endif
19026 			return (error);
19027 		case ENETUNREACH:
19028 			counter_u64_add(rack_saw_enetunreach, 1);
19029 		case EHOSTDOWN:
19030 		case EHOSTUNREACH:
19031 		case ENETDOWN:
19032 			if (TCPS_HAVERCVDSYN(tp->t_state)) {
19033 				tp->t_softerror = error;
19034 			}
19035 			/* FALLTHROUGH */
19036 		default:
19037 			slot = 10 * HPTS_USEC_IN_MSEC;
19038 			rack_start_hpts_timer(rack, tp, cts, slot, 0, 0);
19039 #ifdef TCP_ACCOUNTING
19040 			crtsc = get_cyclecount();
19041 			if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
19042 				tp->tcp_cnt_counters[SND_OUT_FAIL]++;
19043 			}
19044 			counter_u64_add(tcp_cnt_counters[SND_OUT_FAIL], 1);
19045 			if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
19046 				tp->tcp_proc_time[SND_OUT_FAIL] += (crtsc - ts_val);
19047 			}
19048 			counter_u64_add(tcp_proc_time[SND_OUT_FAIL], (crtsc - ts_val));
19049 			sched_unpin();
19050 #endif
19051 			return (error);
19052 		}
19053 	} else {
19054 		rack->rc_enobuf = 0;
19055 		if (IN_FASTRECOVERY(tp->t_flags) && rsm)
19056 			rack->r_ctl.retran_during_recovery += len;
19057 	}
19058 	KMOD_TCPSTAT_INC(tcps_sndtotal);
19059 
19060 	/*
19061 	 * Data sent (as far as we can tell). If this advertises a larger
19062 	 * window than any other segment, then remember the size of the
19063 	 * advertised window. Any pending ACK has now been sent.
19064 	 */
19065 	if (recwin > 0 && SEQ_GT(tp->rcv_nxt + recwin, tp->rcv_adv))
19066 		tp->rcv_adv = tp->rcv_nxt + recwin;
19067 
19068 	tp->last_ack_sent = tp->rcv_nxt;
19069 	tp->t_flags &= ~(TF_ACKNOW | TF_DELACK);
19070 enobufs:
19071 	if (sendalot) {
19072 		/* Do we need to turn off sendalot? */
19073 		if (rack->r_ctl.rc_pace_max_segs &&
19074 		    (tot_len_this_send >= rack->r_ctl.rc_pace_max_segs)) {
19075 			/* We hit our max. */
19076 			sendalot = 0;
19077 		} else if ((rack->rc_user_set_max_segs) &&
19078 			   (tot_len_this_send >= (rack->rc_user_set_max_segs * segsiz))) {
19079 			/* We hit the user defined max */
19080 			sendalot = 0;
19081 		}
19082 	}
19083 	if ((error == 0) && (flags & TH_FIN))
19084 		tcp_log_end_status(tp, TCP_EI_STATUS_SERVER_FIN);
19085 	if (flags & TH_RST) {
19086 		/*
19087 		 * We don't send again after sending a RST.
19088 		 */
19089 		slot = 0;
19090 		sendalot = 0;
19091 		if (error == 0)
19092 			tcp_log_end_status(tp, TCP_EI_STATUS_SERVER_RST);
19093 	} else if ((slot == 0) && (sendalot == 0) && tot_len_this_send) {
19094 		/*
19095 		 * Get our pacing rate, if an error
19096 		 * occurred in sending (ENOBUF) we would
19097 		 * hit the else if with slot preset. Other
19098 		 * errors return.
19099 		 */
19100 		slot = rack_get_pacing_delay(rack, tp, tot_len_this_send, rsm, segsiz);
19101 	}
19102 	if (rsm &&
19103 	    (rsm->r_flags & RACK_HAS_SYN) == 0 &&
19104 	    rack->use_rack_rr) {
19105 		/* Its a retransmit and we use the rack cheat? */
19106 		if ((slot == 0) ||
19107 		    (rack->rc_always_pace == 0) ||
19108 		    (rack->r_rr_config == 1)) {
19109 			/*
19110 			 * We have no pacing set or we
19111 			 * are using old-style rack or
19112 			 * we are overriden to use the old 1ms pacing.
19113 			 */
19114 			slot = rack->r_ctl.rc_min_to;
19115 		}
19116 	}
19117 	/* We have sent clear the flag */
19118 	rack->r_ent_rec_ns = 0;
19119 	if (rack->r_must_retran) {
19120 		if (rsm) {
19121 			rack->r_ctl.rc_out_at_rto -= (rsm->r_end - rsm->r_start);
19122 			if (SEQ_GEQ(rsm->r_end, rack->r_ctl.rc_snd_max_at_rto)) {
19123 				/*
19124 				 * We have retransmitted all.
19125 				 */
19126 				rack->r_must_retran = 0;
19127 				rack->r_ctl.rc_out_at_rto = 0;
19128 			}
19129 		} else if (SEQ_GEQ(tp->snd_max, rack->r_ctl.rc_snd_max_at_rto)) {
19130 			/*
19131 			 * Sending new data will also kill
19132 			 * the loop.
19133 			 */
19134 			rack->r_must_retran = 0;
19135 			rack->r_ctl.rc_out_at_rto = 0;
19136 		}
19137 	}
19138 	rack->r_ctl.fsb.recwin = recwin;
19139 	if ((tp->t_flags & (TF_WASCRECOVERY|TF_WASFRECOVERY)) &&
19140 	    SEQ_GT(tp->snd_max, rack->r_ctl.rc_snd_max_at_rto)) {
19141 		/*
19142 		 * We hit an RTO and now have past snd_max at the RTO
19143 		 * clear all the WAS flags.
19144 		 */
19145 		tp->t_flags &= ~(TF_WASCRECOVERY|TF_WASFRECOVERY);
19146 	}
19147 	if (slot) {
19148 		/* set the rack tcb into the slot N */
19149 		counter_u64_add(rack_paced_segments, 1);
19150 		if ((error == 0) &&
19151 		    rack_use_rfo &&
19152 		    ((flags & (TH_SYN|TH_FIN)) == 0) &&
19153 		    (rsm == NULL) &&
19154 		    (tp->snd_nxt == tp->snd_max) &&
19155 		    (ipoptlen == 0) &&
19156 		    (tp->rcv_numsacks == 0) &&
19157 		    rack->r_fsb_inited &&
19158 		    TCPS_HAVEESTABLISHED(tp->t_state) &&
19159 		    (rack->r_must_retran == 0) &&
19160 		    ((tp->t_flags & TF_NEEDFIN) == 0) &&
19161 		    (len > 0) && (orig_len > 0) &&
19162 		    (orig_len > len) &&
19163 		    ((orig_len - len) >= segsiz) &&
19164 		    ((optlen == 0) ||
19165 		     ((optlen == TCPOLEN_TSTAMP_APPA) && (to.to_flags & TOF_TS)))) {
19166 			/* We can send at least one more MSS using our fsb */
19167 
19168 			rack->r_fast_output = 1;
19169 			rack->r_ctl.fsb.m = sbsndmbuf(sb, (tp->snd_max - tp->snd_una), &rack->r_ctl.fsb.off);
19170 			rack->r_ctl.fsb.o_m_len = rack->r_ctl.fsb.m->m_len;
19171 			rack->r_ctl.fsb.tcp_flags = flags;
19172 			rack->r_ctl.fsb.left_to_send = orig_len - len;
19173 			if (hw_tls)
19174 				rack->r_ctl.fsb.hw_tls = 1;
19175 			else
19176 				rack->r_ctl.fsb.hw_tls = 0;
19177 			KASSERT((rack->r_ctl.fsb.left_to_send <= (sbavail(sb) - (tp->snd_max - tp->snd_una))),
19178 				("rack:%p left_to_send:%u sbavail:%u out:%u",
19179 				 rack, rack->r_ctl.fsb.left_to_send, sbavail(sb),
19180 				 (tp->snd_max - tp->snd_una)));
19181 			if (rack->r_ctl.fsb.left_to_send < segsiz)
19182 				rack->r_fast_output = 0;
19183 			else {
19184 				if (rack->r_ctl.fsb.left_to_send == (sbavail(sb) - (tp->snd_max - tp->snd_una)))
19185 					rack->r_ctl.fsb.rfo_apply_push = 1;
19186 				else
19187 					rack->r_ctl.fsb.rfo_apply_push = 0;
19188 			}
19189 		} else
19190 			rack->r_fast_output = 0;
19191 		rack_log_fsb(rack, tp, so, flags,
19192 			     ipoptlen, orig_len, len, error,
19193 			     (rsm == NULL), optlen, __LINE__, 2);
19194 	} else if (sendalot) {
19195 		int ret;
19196 
19197 		if (len)
19198 			counter_u64_add(rack_unpaced_segments, 1);
19199 		sack_rxmit = 0;
19200 		if ((error == 0) &&
19201 		    rack_use_rfo &&
19202 		    ((flags & (TH_SYN|TH_FIN)) == 0) &&
19203 		    (rsm == NULL) &&
19204 		    (ipoptlen == 0) &&
19205 		    (tp->rcv_numsacks == 0) &&
19206 		    (tp->snd_nxt == tp->snd_max) &&
19207 		    (rack->r_must_retran == 0) &&
19208 		    rack->r_fsb_inited &&
19209 		    TCPS_HAVEESTABLISHED(tp->t_state) &&
19210 		    ((tp->t_flags & TF_NEEDFIN) == 0) &&
19211 		    (len > 0) && (orig_len > 0) &&
19212 		    (orig_len > len) &&
19213 		    ((orig_len - len) >= segsiz) &&
19214 		    ((optlen == 0) ||
19215 		     ((optlen == TCPOLEN_TSTAMP_APPA) && (to.to_flags & TOF_TS)))) {
19216 			/* we can use fast_output for more */
19217 
19218 			rack->r_fast_output = 1;
19219 			rack->r_ctl.fsb.m = sbsndmbuf(sb, (tp->snd_max - tp->snd_una), &rack->r_ctl.fsb.off);
19220 			rack->r_ctl.fsb.o_m_len = rack->r_ctl.fsb.m->m_len;
19221 			rack->r_ctl.fsb.tcp_flags = flags;
19222 			rack->r_ctl.fsb.left_to_send = orig_len - len;
19223 			if (hw_tls)
19224 				rack->r_ctl.fsb.hw_tls = 1;
19225 			else
19226 				rack->r_ctl.fsb.hw_tls = 0;
19227 			KASSERT((rack->r_ctl.fsb.left_to_send <= (sbavail(sb) - (tp->snd_max - tp->snd_una))),
19228 				("rack:%p left_to_send:%u sbavail:%u out:%u",
19229 				 rack, rack->r_ctl.fsb.left_to_send, sbavail(sb),
19230 				 (tp->snd_max - tp->snd_una)));
19231 			if (rack->r_ctl.fsb.left_to_send < segsiz) {
19232 				rack->r_fast_output = 0;
19233 			}
19234 			if (rack->r_fast_output) {
19235 				if (rack->r_ctl.fsb.left_to_send == (sbavail(sb) - (tp->snd_max - tp->snd_una)))
19236 					rack->r_ctl.fsb.rfo_apply_push = 1;
19237 				else
19238 					rack->r_ctl.fsb.rfo_apply_push = 0;
19239 				rack_log_fsb(rack, tp, so, flags,
19240 					     ipoptlen, orig_len, len, error,
19241 					     (rsm == NULL), optlen, __LINE__, 3);
19242 				error = 0;
19243 				ret = rack_fast_output(tp, rack, ts_val, cts, ms_cts, &tv, tot_len_this_send, &error);
19244 				if (ret >= 0)
19245 					return (ret);
19246 			        else if (error)
19247 					goto nomore;
19248 
19249 			}
19250 		}
19251 		goto again;
19252 	} else if (len) {
19253 		counter_u64_add(rack_unpaced_segments, 1);
19254 	}
19255 	/* Assure when we leave that snd_nxt will point to top */
19256 	if (SEQ_GT(tp->snd_max, tp->snd_nxt))
19257 		tp->snd_nxt = tp->snd_max;
19258 	rack_start_hpts_timer(rack, tp, cts, slot, tot_len_this_send, 0);
19259 #ifdef TCP_ACCOUNTING
19260 	crtsc = get_cyclecount() - ts_val;
19261 	if (tot_len_this_send) {
19262 		if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
19263 			tp->tcp_cnt_counters[SND_OUT_DATA]++;
19264 		}
19265 		counter_u64_add(tcp_cnt_counters[SND_OUT_DATA], 1);
19266 		if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
19267 			tp->tcp_proc_time[SND_OUT_DATA] += crtsc;
19268 		}
19269 		counter_u64_add(tcp_proc_time[SND_OUT_DATA], crtsc);
19270 		if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
19271 			tp->tcp_cnt_counters[CNT_OF_MSS_OUT] += ((tot_len_this_send + segsiz - 1) /segsiz);
19272 		}
19273 		counter_u64_add(tcp_cnt_counters[CNT_OF_MSS_OUT], ((tot_len_this_send + segsiz - 1) /segsiz));
19274 	} else {
19275 		if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
19276 			tp->tcp_cnt_counters[SND_OUT_ACK]++;
19277 		}
19278 		counter_u64_add(tcp_cnt_counters[SND_OUT_ACK], 1);
19279 		if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
19280 			tp->tcp_proc_time[SND_OUT_ACK] += crtsc;
19281 		}
19282 		counter_u64_add(tcp_proc_time[SND_OUT_ACK], crtsc);
19283 	}
19284 	sched_unpin();
19285 #endif
19286 	if (error == ENOBUFS)
19287 		error = 0;
19288 	return (error);
19289 }
19290 
19291 static void
19292 rack_update_seg(struct tcp_rack *rack)
19293 {
19294 	uint32_t orig_val;
19295 
19296 	orig_val = rack->r_ctl.rc_pace_max_segs;
19297 	rack_set_pace_segments(rack->rc_tp, rack, __LINE__, NULL);
19298 	if (orig_val != rack->r_ctl.rc_pace_max_segs)
19299 		rack_log_pacing_delay_calc(rack, 0, 0, orig_val, 0, 0, 15, __LINE__, NULL, 0);
19300 }
19301 
19302 static void
19303 rack_mtu_change(struct tcpcb *tp)
19304 {
19305 	/*
19306 	 * The MSS may have changed
19307 	 */
19308 	struct tcp_rack *rack;
19309 
19310 	rack = (struct tcp_rack *)tp->t_fb_ptr;
19311 	if (rack->r_ctl.rc_pace_min_segs != ctf_fixed_maxseg(tp)) {
19312 		/*
19313 		 * The MTU has changed we need to resend everything
19314 		 * since all we have sent is lost. We first fix
19315 		 * up the mtu though.
19316 		 */
19317 		rack_set_pace_segments(tp, rack, __LINE__, NULL);
19318 		/* We treat this like a full retransmit timeout without the cwnd adjustment */
19319 		rack_remxt_tmr(tp);
19320 		rack->r_fast_output = 0;
19321 		rack->r_ctl.rc_out_at_rto = ctf_flight_size(tp,
19322 						rack->r_ctl.rc_sacked);
19323 		rack->r_ctl.rc_snd_max_at_rto = tp->snd_max;
19324 		rack->r_must_retran = 1;
19325 
19326 	}
19327 	sack_filter_clear(&rack->r_ctl.rack_sf, tp->snd_una);
19328 	/* We don't use snd_nxt to retransmit */
19329 	tp->snd_nxt = tp->snd_max;
19330 }
19331 
19332 static int
19333 rack_set_profile(struct tcp_rack *rack, int prof)
19334 {
19335 	int err = EINVAL;
19336 	if (prof == 1) {
19337 		/* pace_always=1 */
19338 		if (rack->rc_always_pace == 0) {
19339 			if (tcp_can_enable_pacing() == 0)
19340 				return (EBUSY);
19341 		}
19342 		rack->rc_always_pace = 1;
19343 		if (rack->use_fixed_rate || rack->gp_ready)
19344 			rack_set_cc_pacing(rack);
19345 		rack->rc_inp->inp_flags2 |= INP_SUPPORTS_MBUFQ;
19346 		rack->rack_attempt_hdwr_pace = 0;
19347 		/* cmpack=1 */
19348 		if (rack_use_cmp_acks)
19349 			rack->r_use_cmp_ack = 1;
19350 		if (TCPS_HAVEESTABLISHED(rack->rc_tp->t_state) &&
19351 		    rack->r_use_cmp_ack)
19352 			rack->rc_inp->inp_flags2 |= INP_MBUF_ACKCMP;
19353 		/* scwnd=1 */
19354 		rack->rack_enable_scwnd = 1;
19355 		/* dynamic=100 */
19356 		rack->rc_gp_dyn_mul = 1;
19357 		/* gp_inc_ca */
19358 		rack->r_ctl.rack_per_of_gp_ca = 100;
19359 		/* rrr_conf=3 */
19360 		rack->r_rr_config = 3;
19361 		/* npush=2 */
19362 		rack->r_ctl.rc_no_push_at_mrtt = 2;
19363 		/* fillcw=1 */
19364 		rack->rc_pace_to_cwnd = 1;
19365 		rack->rc_pace_fill_if_rttin_range = 0;
19366 		rack->rtt_limit_mul = 0;
19367 		/* noprr=1 */
19368 		rack->rack_no_prr = 1;
19369 		/* lscwnd=1 */
19370 		rack->r_limit_scw = 1;
19371 		/* gp_inc_rec */
19372 		rack->r_ctl.rack_per_of_gp_rec = 90;
19373 		err = 0;
19374 
19375 	} else if (prof == 3) {
19376 		/* Same as profile one execept fill_cw becomes 2 (less aggressive set) */
19377 		/* pace_always=1 */
19378 		if (rack->rc_always_pace == 0) {
19379 			if (tcp_can_enable_pacing() == 0)
19380 				return (EBUSY);
19381 		}
19382 		rack->rc_always_pace = 1;
19383 		if (rack->use_fixed_rate || rack->gp_ready)
19384 			rack_set_cc_pacing(rack);
19385 		rack->rc_inp->inp_flags2 |= INP_SUPPORTS_MBUFQ;
19386 		rack->rack_attempt_hdwr_pace = 0;
19387 		/* cmpack=1 */
19388 		if (rack_use_cmp_acks)
19389 			rack->r_use_cmp_ack = 1;
19390 		if (TCPS_HAVEESTABLISHED(rack->rc_tp->t_state) &&
19391 		    rack->r_use_cmp_ack)
19392 			rack->rc_inp->inp_flags2 |= INP_MBUF_ACKCMP;
19393 		/* scwnd=1 */
19394 		rack->rack_enable_scwnd = 1;
19395 		/* dynamic=100 */
19396 		rack->rc_gp_dyn_mul = 1;
19397 		/* gp_inc_ca */
19398 		rack->r_ctl.rack_per_of_gp_ca = 100;
19399 		/* rrr_conf=3 */
19400 		rack->r_rr_config = 3;
19401 		/* npush=2 */
19402 		rack->r_ctl.rc_no_push_at_mrtt = 2;
19403 		/* fillcw=2 */
19404 		rack->rc_pace_to_cwnd = 1;
19405 		rack->r_fill_less_agg = 1;
19406 		rack->rc_pace_fill_if_rttin_range = 0;
19407 		rack->rtt_limit_mul = 0;
19408 		/* noprr=1 */
19409 		rack->rack_no_prr = 1;
19410 		/* lscwnd=1 */
19411 		rack->r_limit_scw = 1;
19412 		/* gp_inc_rec */
19413 		rack->r_ctl.rack_per_of_gp_rec = 90;
19414 		err = 0;
19415 
19416 
19417 	} else if (prof == 2) {
19418 		/* cmpack=1 */
19419 		if (rack->rc_always_pace == 0) {
19420 			if (tcp_can_enable_pacing() == 0)
19421 				return (EBUSY);
19422 		}
19423 		rack->rc_always_pace = 1;
19424 		if (rack->use_fixed_rate || rack->gp_ready)
19425 			rack_set_cc_pacing(rack);
19426 		rack->r_use_cmp_ack = 1;
19427 		if (TCPS_HAVEESTABLISHED(rack->rc_tp->t_state))
19428 			rack->rc_inp->inp_flags2 |= INP_MBUF_ACKCMP;
19429 		/* pace_always=1 */
19430 		rack->rc_inp->inp_flags2 |= INP_SUPPORTS_MBUFQ;
19431 		/* scwnd=1 */
19432 		rack->rack_enable_scwnd = 1;
19433 		/* dynamic=100 */
19434 		rack->rc_gp_dyn_mul = 1;
19435 		rack->r_ctl.rack_per_of_gp_ca = 100;
19436 		/* rrr_conf=3 */
19437 		rack->r_rr_config = 3;
19438 		/* npush=2 */
19439 		rack->r_ctl.rc_no_push_at_mrtt = 2;
19440 		/* fillcw=1 */
19441 		rack->rc_pace_to_cwnd = 1;
19442 		rack->rc_pace_fill_if_rttin_range = 0;
19443 		rack->rtt_limit_mul = 0;
19444 		/* noprr=1 */
19445 		rack->rack_no_prr = 1;
19446 		/* lscwnd=0 */
19447 		rack->r_limit_scw = 0;
19448 		err = 0;
19449 	} else if (prof == 0) {
19450 		/* This changes things back to the default settings */
19451 		err = 0;
19452 		if (rack->rc_always_pace) {
19453 			tcp_decrement_paced_conn();
19454 			rack_undo_cc_pacing(rack);
19455 			rack->rc_always_pace = 0;
19456 		}
19457 		if (rack_pace_every_seg && tcp_can_enable_pacing()) {
19458 			rack->rc_always_pace = 1;
19459 			if (rack->use_fixed_rate || rack->gp_ready)
19460 				rack_set_cc_pacing(rack);
19461 		} else
19462 			rack->rc_always_pace = 0;
19463 		if (rack_dsack_std_based & 0x1) {
19464 			/* Basically this means all rack timers are at least (srtt + 1/4 srtt) */
19465 			rack->rc_rack_tmr_std_based = 1;
19466 		}
19467 		if (rack_dsack_std_based & 0x2) {
19468 			/* Basically this means  rack timers are extended based on dsack by up to (2 * srtt) */
19469 			rack->rc_rack_use_dsack = 1;
19470 		}
19471 		if (rack_use_cmp_acks)
19472 			rack->r_use_cmp_ack = 1;
19473 		else
19474 			rack->r_use_cmp_ack = 0;
19475 		if (rack_disable_prr)
19476 			rack->rack_no_prr = 1;
19477 		else
19478 			rack->rack_no_prr = 0;
19479 		if (rack_gp_no_rec_chg)
19480 			rack->rc_gp_no_rec_chg = 1;
19481 		else
19482 			rack->rc_gp_no_rec_chg = 0;
19483 		if (rack_enable_mqueue_for_nonpaced || rack->r_use_cmp_ack) {
19484 			rack->r_mbuf_queue = 1;
19485 			if (TCPS_HAVEESTABLISHED(rack->rc_tp->t_state))
19486 				rack->rc_inp->inp_flags2 |= INP_MBUF_ACKCMP;
19487 			rack->rc_inp->inp_flags2 |= INP_SUPPORTS_MBUFQ;
19488 		} else {
19489 			rack->r_mbuf_queue = 0;
19490 			rack->rc_inp->inp_flags2 &= ~INP_SUPPORTS_MBUFQ;
19491 		}
19492 		if (rack_enable_shared_cwnd)
19493 			rack->rack_enable_scwnd = 1;
19494 		else
19495 			rack->rack_enable_scwnd = 0;
19496 		if (rack_do_dyn_mul) {
19497 			/* When dynamic adjustment is on CA needs to start at 100% */
19498 			rack->rc_gp_dyn_mul = 1;
19499 			if (rack_do_dyn_mul >= 100)
19500 				rack->r_ctl.rack_per_of_gp_ca = rack_do_dyn_mul;
19501 		} else {
19502 			rack->r_ctl.rack_per_of_gp_ca = rack_per_of_gp_ca;
19503 			rack->rc_gp_dyn_mul = 0;
19504 		}
19505 		rack->r_rr_config = 0;
19506 		rack->r_ctl.rc_no_push_at_mrtt = 0;
19507 		rack->rc_pace_to_cwnd = 0;
19508 		rack->rc_pace_fill_if_rttin_range = 0;
19509 		rack->rtt_limit_mul = 0;
19510 
19511 		if (rack_enable_hw_pacing)
19512 			rack->rack_hdw_pace_ena = 1;
19513 		else
19514 			rack->rack_hdw_pace_ena = 0;
19515 		if (rack_disable_prr)
19516 			rack->rack_no_prr = 1;
19517 		else
19518 			rack->rack_no_prr = 0;
19519 		if (rack_limits_scwnd)
19520 			rack->r_limit_scw  = 1;
19521 		else
19522 			rack->r_limit_scw  = 0;
19523 		err = 0;
19524 	}
19525 	return (err);
19526 }
19527 
19528 static int
19529 rack_add_deferred_option(struct tcp_rack *rack, int sopt_name, uint64_t loptval)
19530 {
19531 	struct deferred_opt_list *dol;
19532 
19533 	dol = malloc(sizeof(struct deferred_opt_list),
19534 		     M_TCPFSB, M_NOWAIT|M_ZERO);
19535 	if (dol == NULL) {
19536 		/*
19537 		 * No space yikes -- fail out..
19538 		 */
19539 		return (0);
19540 	}
19541 	dol->optname = sopt_name;
19542 	dol->optval = loptval;
19543 	TAILQ_INSERT_TAIL(&rack->r_ctl.opt_list, dol, next);
19544 	return (1);
19545 }
19546 
19547 static int
19548 rack_process_option(struct tcpcb *tp, struct tcp_rack *rack, int sopt_name,
19549 		    uint32_t optval, uint64_t loptval)
19550 {
19551 	struct epoch_tracker et;
19552 	struct sockopt sopt;
19553 	struct cc_newreno_opts opt;
19554 	uint64_t val;
19555 	int error = 0;
19556 	uint16_t ca, ss;
19557 
19558 	switch (sopt_name) {
19559 
19560 	case TCP_RACK_DSACK_OPT:
19561 		RACK_OPTS_INC(tcp_rack_dsack_opt);
19562 		if (optval & 0x1) {
19563 			rack->rc_rack_tmr_std_based = 1;
19564 		} else {
19565 			rack->rc_rack_tmr_std_based = 0;
19566 		}
19567 		if (optval & 0x2) {
19568 			rack->rc_rack_use_dsack = 1;
19569 		} else {
19570 			rack->rc_rack_use_dsack = 0;
19571 		}
19572 		rack_log_dsack_event(rack, 5, __LINE__, 0, 0);
19573 		break;
19574 	case TCP_RACK_PACING_BETA:
19575 		RACK_OPTS_INC(tcp_rack_beta);
19576 		if (strcmp(tp->cc_algo->name, CCALGONAME_NEWRENO) != 0) {
19577 			/* This only works for newreno. */
19578 			error = EINVAL;
19579 			break;
19580 		}
19581 		if (rack->rc_pacing_cc_set) {
19582 			/*
19583 			 * Set them into the real CC module
19584 			 * whats in the rack pcb is the old values
19585 			 * to be used on restoral/
19586 			 */
19587 			sopt.sopt_dir = SOPT_SET;
19588 			opt.name = CC_NEWRENO_BETA;
19589 			opt.val = optval;
19590 			if (CC_ALGO(tp)->ctl_output != NULL)
19591 				error = CC_ALGO(tp)->ctl_output(tp->ccv, &sopt, &opt);
19592 			else {
19593 				error = ENOENT;
19594 				break;
19595 			}
19596 		} else {
19597 			/*
19598 			 * Not pacing yet so set it into our local
19599 			 * rack pcb storage.
19600 			 */
19601 			rack->r_ctl.rc_saved_beta.beta = optval;
19602 		}
19603 		break;
19604 	case TCP_RACK_TIMER_SLOP:
19605 		RACK_OPTS_INC(tcp_rack_timer_slop);
19606 		rack->r_ctl.timer_slop = optval;
19607 		if (rack->rc_tp->t_srtt) {
19608 			/*
19609 			 * If we have an SRTT lets update t_rxtcur
19610 			 * to have the new slop.
19611 			 */
19612 			RACK_TCPT_RANGESET(tp->t_rxtcur, RACK_REXMTVAL(tp),
19613 					   rack_rto_min, rack_rto_max,
19614 					   rack->r_ctl.timer_slop);
19615 		}
19616 		break;
19617 	case TCP_RACK_PACING_BETA_ECN:
19618 		RACK_OPTS_INC(tcp_rack_beta_ecn);
19619 		if (strcmp(tp->cc_algo->name, CCALGONAME_NEWRENO) != 0) {
19620 			/* This only works for newreno. */
19621 			error = EINVAL;
19622 			break;
19623 		}
19624 		if (rack->rc_pacing_cc_set) {
19625 			/*
19626 			 * Set them into the real CC module
19627 			 * whats in the rack pcb is the old values
19628 			 * to be used on restoral/
19629 			 */
19630 			sopt.sopt_dir = SOPT_SET;
19631 			opt.name = CC_NEWRENO_BETA_ECN;
19632 			opt.val = optval;
19633 			if (CC_ALGO(tp)->ctl_output != NULL)
19634 				error = CC_ALGO(tp)->ctl_output(tp->ccv, &sopt, &opt);
19635 			else
19636 				error = ENOENT;
19637 		} else {
19638 			/*
19639 			 * Not pacing yet so set it into our local
19640 			 * rack pcb storage.
19641 			 */
19642 			rack->r_ctl.rc_saved_beta.beta_ecn = optval;
19643 			rack->r_ctl.rc_saved_beta.newreno_flags = CC_NEWRENO_BETA_ECN_ENABLED;
19644 		}
19645 		break;
19646 	case TCP_DEFER_OPTIONS:
19647 		RACK_OPTS_INC(tcp_defer_opt);
19648 		if (optval) {
19649 			if (rack->gp_ready) {
19650 				/* Too late */
19651 				error = EINVAL;
19652 				break;
19653 			}
19654 			rack->defer_options = 1;
19655 		} else
19656 			rack->defer_options = 0;
19657 		break;
19658 	case TCP_RACK_MEASURE_CNT:
19659 		RACK_OPTS_INC(tcp_rack_measure_cnt);
19660 		if (optval && (optval <= 0xff)) {
19661 			rack->r_ctl.req_measurements = optval;
19662 		} else
19663 			error = EINVAL;
19664 		break;
19665 	case TCP_REC_ABC_VAL:
19666 		RACK_OPTS_INC(tcp_rec_abc_val);
19667 		if (optval > 0)
19668 			rack->r_use_labc_for_rec = 1;
19669 		else
19670 			rack->r_use_labc_for_rec = 0;
19671 		break;
19672 	case TCP_RACK_ABC_VAL:
19673 		RACK_OPTS_INC(tcp_rack_abc_val);
19674 		if ((optval > 0) && (optval < 255))
19675 			rack->rc_labc = optval;
19676 		else
19677 			error = EINVAL;
19678 		break;
19679 	case TCP_HDWR_UP_ONLY:
19680 		RACK_OPTS_INC(tcp_pacing_up_only);
19681 		if (optval)
19682 			rack->r_up_only = 1;
19683 		else
19684 			rack->r_up_only = 0;
19685 		break;
19686 	case TCP_PACING_RATE_CAP:
19687 		RACK_OPTS_INC(tcp_pacing_rate_cap);
19688 		rack->r_ctl.bw_rate_cap = loptval;
19689 		break;
19690 	case TCP_RACK_PROFILE:
19691 		RACK_OPTS_INC(tcp_profile);
19692 		error = rack_set_profile(rack, optval);
19693 		break;
19694 	case TCP_USE_CMP_ACKS:
19695 		RACK_OPTS_INC(tcp_use_cmp_acks);
19696 		if ((optval == 0) && (rack->rc_inp->inp_flags2 & INP_MBUF_ACKCMP)) {
19697 			/* You can't turn it off once its on! */
19698 			error = EINVAL;
19699 		} else if ((optval == 1) && (rack->r_use_cmp_ack == 0)) {
19700 			rack->r_use_cmp_ack = 1;
19701 			rack->r_mbuf_queue = 1;
19702 			tp->t_inpcb->inp_flags2 |= INP_SUPPORTS_MBUFQ;
19703 		}
19704 		if (rack->r_use_cmp_ack && TCPS_HAVEESTABLISHED(tp->t_state))
19705 			rack->rc_inp->inp_flags2 |= INP_MBUF_ACKCMP;
19706 		break;
19707 	case TCP_SHARED_CWND_TIME_LIMIT:
19708 		RACK_OPTS_INC(tcp_lscwnd);
19709 		if (optval)
19710 			rack->r_limit_scw = 1;
19711 		else
19712 			rack->r_limit_scw = 0;
19713 		break;
19714  	case TCP_RACK_PACE_TO_FILL:
19715 		RACK_OPTS_INC(tcp_fillcw);
19716 		if (optval == 0)
19717 			rack->rc_pace_to_cwnd = 0;
19718 		else {
19719 			rack->rc_pace_to_cwnd = 1;
19720 			if (optval > 1)
19721 				rack->r_fill_less_agg = 1;
19722 		}
19723 		if ((optval >= rack_gp_rtt_maxmul) &&
19724 		    rack_gp_rtt_maxmul &&
19725 		    (optval < 0xf)) {
19726 			rack->rc_pace_fill_if_rttin_range = 1;
19727 			rack->rtt_limit_mul = optval;
19728 		} else {
19729 			rack->rc_pace_fill_if_rttin_range = 0;
19730 			rack->rtt_limit_mul = 0;
19731 		}
19732 		break;
19733 	case TCP_RACK_NO_PUSH_AT_MAX:
19734 		RACK_OPTS_INC(tcp_npush);
19735 		if (optval == 0)
19736 			rack->r_ctl.rc_no_push_at_mrtt = 0;
19737 		else if (optval < 0xff)
19738 			rack->r_ctl.rc_no_push_at_mrtt = optval;
19739 		else
19740 			error = EINVAL;
19741 		break;
19742 	case TCP_SHARED_CWND_ENABLE:
19743 		RACK_OPTS_INC(tcp_rack_scwnd);
19744 		if (optval == 0)
19745 			rack->rack_enable_scwnd = 0;
19746 		else
19747 			rack->rack_enable_scwnd = 1;
19748 		break;
19749 	case TCP_RACK_MBUF_QUEUE:
19750 		/* Now do we use the LRO mbuf-queue feature */
19751 		RACK_OPTS_INC(tcp_rack_mbufq);
19752 		if (optval || rack->r_use_cmp_ack)
19753 			rack->r_mbuf_queue = 1;
19754 		else
19755 			rack->r_mbuf_queue = 0;
19756 		if  (rack->r_mbuf_queue || rack->rc_always_pace || rack->r_use_cmp_ack)
19757 			tp->t_inpcb->inp_flags2 |= INP_SUPPORTS_MBUFQ;
19758 		else
19759 			tp->t_inpcb->inp_flags2 &= ~INP_SUPPORTS_MBUFQ;
19760 		break;
19761 	case TCP_RACK_NONRXT_CFG_RATE:
19762 		RACK_OPTS_INC(tcp_rack_cfg_rate);
19763 		if (optval == 0)
19764 			rack->rack_rec_nonrxt_use_cr = 0;
19765 		else
19766 			rack->rack_rec_nonrxt_use_cr = 1;
19767 		break;
19768 	case TCP_NO_PRR:
19769 		RACK_OPTS_INC(tcp_rack_noprr);
19770 		if (optval == 0)
19771 			rack->rack_no_prr = 0;
19772 		else if (optval == 1)
19773 			rack->rack_no_prr = 1;
19774 		else if (optval == 2)
19775 			rack->no_prr_addback = 1;
19776 		else
19777 			error = EINVAL;
19778 		break;
19779 	case TCP_TIMELY_DYN_ADJ:
19780 		RACK_OPTS_INC(tcp_timely_dyn);
19781 		if (optval == 0)
19782 			rack->rc_gp_dyn_mul = 0;
19783 		else {
19784 			rack->rc_gp_dyn_mul = 1;
19785 			if (optval >= 100) {
19786 				/*
19787 				 * If the user sets something 100 or more
19788 				 * its the gp_ca value.
19789 				 */
19790 				rack->r_ctl.rack_per_of_gp_ca  = optval;
19791 			}
19792 		}
19793 		break;
19794 	case TCP_RACK_DO_DETECTION:
19795 		RACK_OPTS_INC(tcp_rack_do_detection);
19796 		if (optval == 0)
19797 			rack->do_detection = 0;
19798 		else
19799 			rack->do_detection = 1;
19800 		break;
19801 	case TCP_RACK_TLP_USE:
19802 		if ((optval < TLP_USE_ID) || (optval > TLP_USE_TWO_TWO)) {
19803 			error = EINVAL;
19804 			break;
19805 		}
19806 		RACK_OPTS_INC(tcp_tlp_use);
19807 		rack->rack_tlp_threshold_use = optval;
19808 		break;
19809 	case TCP_RACK_TLP_REDUCE:
19810 		/* RACK TLP cwnd reduction (bool) */
19811 		RACK_OPTS_INC(tcp_rack_tlp_reduce);
19812 		rack->r_ctl.rc_tlp_cwnd_reduce = optval;
19813 		break;
19814 	/*  Pacing related ones */
19815 	case TCP_RACK_PACE_ALWAYS:
19816 		/*
19817 		 * zero is old rack method, 1 is new
19818 		 * method using a pacing rate.
19819 		 */
19820 		RACK_OPTS_INC(tcp_rack_pace_always);
19821 		if (optval > 0) {
19822 			if (rack->rc_always_pace) {
19823 				error = EALREADY;
19824 				break;
19825 			} else if (tcp_can_enable_pacing()) {
19826 				rack->rc_always_pace = 1;
19827 				if (rack->use_fixed_rate || rack->gp_ready)
19828 					rack_set_cc_pacing(rack);
19829 			}
19830 			else {
19831 				error = ENOSPC;
19832 				break;
19833 			}
19834 		} else {
19835 			if (rack->rc_always_pace) {
19836 				tcp_decrement_paced_conn();
19837 				rack->rc_always_pace = 0;
19838 				rack_undo_cc_pacing(rack);
19839 			}
19840 		}
19841 		if  (rack->r_mbuf_queue || rack->rc_always_pace || rack->r_use_cmp_ack)
19842 			tp->t_inpcb->inp_flags2 |= INP_SUPPORTS_MBUFQ;
19843 		else
19844 			tp->t_inpcb->inp_flags2 &= ~INP_SUPPORTS_MBUFQ;
19845 		/* A rate may be set irate or other, if so set seg size */
19846 		rack_update_seg(rack);
19847 		break;
19848 	case TCP_BBR_RACK_INIT_RATE:
19849 		RACK_OPTS_INC(tcp_initial_rate);
19850 		val = optval;
19851 		/* Change from kbits per second to bytes per second */
19852 		val *= 1000;
19853 		val /= 8;
19854 		rack->r_ctl.init_rate = val;
19855 		if (rack->rc_init_win != rack_default_init_window) {
19856 			uint32_t win, snt;
19857 
19858 			/*
19859 			 * Options don't always get applied
19860 			 * in the order you think. So in order
19861 			 * to assure we update a cwnd we need
19862 			 * to check and see if we are still
19863 			 * where we should raise the cwnd.
19864 			 */
19865 			win = rc_init_window(rack);
19866 			if (SEQ_GT(tp->snd_max, tp->iss))
19867 				snt = tp->snd_max - tp->iss;
19868 			else
19869 				snt = 0;
19870 			if ((snt < win) &&
19871 			    (tp->snd_cwnd < win))
19872 				tp->snd_cwnd = win;
19873 		}
19874 		if (rack->rc_always_pace)
19875 			rack_update_seg(rack);
19876 		break;
19877 	case TCP_BBR_IWINTSO:
19878 		RACK_OPTS_INC(tcp_initial_win);
19879 		if (optval && (optval <= 0xff)) {
19880 			uint32_t win, snt;
19881 
19882 			rack->rc_init_win = optval;
19883 			win = rc_init_window(rack);
19884 			if (SEQ_GT(tp->snd_max, tp->iss))
19885 				snt = tp->snd_max - tp->iss;
19886 			else
19887 				snt = 0;
19888 			if ((snt < win) &&
19889 			    (tp->t_srtt |
19890 #ifdef NETFLIX_PEAKRATE
19891 			     tp->t_maxpeakrate |
19892 #endif
19893 			     rack->r_ctl.init_rate)) {
19894 				/*
19895 				 * We are not past the initial window
19896 				 * and we have some bases for pacing,
19897 				 * so we need to possibly adjust up
19898 				 * the cwnd. Note even if we don't set
19899 				 * the cwnd, its still ok to raise the rc_init_win
19900 				 * which can be used coming out of idle when we
19901 				 * would have a rate.
19902 				 */
19903 				if (tp->snd_cwnd < win)
19904 					tp->snd_cwnd = win;
19905 			}
19906 			if (rack->rc_always_pace)
19907 				rack_update_seg(rack);
19908 		} else
19909 			error = EINVAL;
19910 		break;
19911 	case TCP_RACK_FORCE_MSEG:
19912 		RACK_OPTS_INC(tcp_rack_force_max_seg);
19913 		if (optval)
19914 			rack->rc_force_max_seg = 1;
19915 		else
19916 			rack->rc_force_max_seg = 0;
19917 		break;
19918 	case TCP_RACK_PACE_MAX_SEG:
19919 		/* Max segments size in a pace in bytes */
19920 		RACK_OPTS_INC(tcp_rack_max_seg);
19921 		rack->rc_user_set_max_segs = optval;
19922 		rack_set_pace_segments(tp, rack, __LINE__, NULL);
19923 		break;
19924 	case TCP_RACK_PACE_RATE_REC:
19925 		/* Set the fixed pacing rate in Bytes per second ca */
19926 		RACK_OPTS_INC(tcp_rack_pace_rate_rec);
19927 		rack->r_ctl.rc_fixed_pacing_rate_rec = optval;
19928 		if (rack->r_ctl.rc_fixed_pacing_rate_ca == 0)
19929 			rack->r_ctl.rc_fixed_pacing_rate_ca = optval;
19930 		if (rack->r_ctl.rc_fixed_pacing_rate_ss == 0)
19931 			rack->r_ctl.rc_fixed_pacing_rate_ss = optval;
19932 		rack->use_fixed_rate = 1;
19933 		if (rack->rc_always_pace)
19934 			rack_set_cc_pacing(rack);
19935 		rack_log_pacing_delay_calc(rack,
19936 					   rack->r_ctl.rc_fixed_pacing_rate_ss,
19937 					   rack->r_ctl.rc_fixed_pacing_rate_ca,
19938 					   rack->r_ctl.rc_fixed_pacing_rate_rec, 0, 0, 8,
19939 					   __LINE__, NULL,0);
19940 		break;
19941 
19942 	case TCP_RACK_PACE_RATE_SS:
19943 		/* Set the fixed pacing rate in Bytes per second ca */
19944 		RACK_OPTS_INC(tcp_rack_pace_rate_ss);
19945 		rack->r_ctl.rc_fixed_pacing_rate_ss = optval;
19946 		if (rack->r_ctl.rc_fixed_pacing_rate_ca == 0)
19947 			rack->r_ctl.rc_fixed_pacing_rate_ca = optval;
19948 		if (rack->r_ctl.rc_fixed_pacing_rate_rec == 0)
19949 			rack->r_ctl.rc_fixed_pacing_rate_rec = optval;
19950 		rack->use_fixed_rate = 1;
19951 		if (rack->rc_always_pace)
19952 			rack_set_cc_pacing(rack);
19953 		rack_log_pacing_delay_calc(rack,
19954 					   rack->r_ctl.rc_fixed_pacing_rate_ss,
19955 					   rack->r_ctl.rc_fixed_pacing_rate_ca,
19956 					   rack->r_ctl.rc_fixed_pacing_rate_rec, 0, 0, 8,
19957 					   __LINE__, NULL, 0);
19958 		break;
19959 
19960 	case TCP_RACK_PACE_RATE_CA:
19961 		/* Set the fixed pacing rate in Bytes per second ca */
19962 		RACK_OPTS_INC(tcp_rack_pace_rate_ca);
19963 		rack->r_ctl.rc_fixed_pacing_rate_ca = optval;
19964 		if (rack->r_ctl.rc_fixed_pacing_rate_ss == 0)
19965 			rack->r_ctl.rc_fixed_pacing_rate_ss = optval;
19966 		if (rack->r_ctl.rc_fixed_pacing_rate_rec == 0)
19967 			rack->r_ctl.rc_fixed_pacing_rate_rec = optval;
19968 		rack->use_fixed_rate = 1;
19969 		if (rack->rc_always_pace)
19970 			rack_set_cc_pacing(rack);
19971 		rack_log_pacing_delay_calc(rack,
19972 					   rack->r_ctl.rc_fixed_pacing_rate_ss,
19973 					   rack->r_ctl.rc_fixed_pacing_rate_ca,
19974 					   rack->r_ctl.rc_fixed_pacing_rate_rec, 0, 0, 8,
19975 					   __LINE__, NULL, 0);
19976 		break;
19977 	case TCP_RACK_GP_INCREASE_REC:
19978 		RACK_OPTS_INC(tcp_gp_inc_rec);
19979 		rack->r_ctl.rack_per_of_gp_rec = optval;
19980 		rack_log_pacing_delay_calc(rack,
19981 					   rack->r_ctl.rack_per_of_gp_ss,
19982 					   rack->r_ctl.rack_per_of_gp_ca,
19983 					   rack->r_ctl.rack_per_of_gp_rec, 0, 0, 1,
19984 					   __LINE__, NULL, 0);
19985 		break;
19986 	case TCP_RACK_GP_INCREASE_CA:
19987 		RACK_OPTS_INC(tcp_gp_inc_ca);
19988 		ca = optval;
19989 		if (ca < 100) {
19990 			/*
19991 			 * We don't allow any reduction
19992 			 * over the GP b/w.
19993 			 */
19994 			error = EINVAL;
19995 			break;
19996 		}
19997 		rack->r_ctl.rack_per_of_gp_ca = ca;
19998 		rack_log_pacing_delay_calc(rack,
19999 					   rack->r_ctl.rack_per_of_gp_ss,
20000 					   rack->r_ctl.rack_per_of_gp_ca,
20001 					   rack->r_ctl.rack_per_of_gp_rec, 0, 0, 1,
20002 					   __LINE__, NULL, 0);
20003 		break;
20004 	case TCP_RACK_GP_INCREASE_SS:
20005 		RACK_OPTS_INC(tcp_gp_inc_ss);
20006 		ss = optval;
20007 		if (ss < 100) {
20008 			/*
20009 			 * We don't allow any reduction
20010 			 * over the GP b/w.
20011 			 */
20012 			error = EINVAL;
20013 			break;
20014 		}
20015 		rack->r_ctl.rack_per_of_gp_ss = ss;
20016 		rack_log_pacing_delay_calc(rack,
20017 					   rack->r_ctl.rack_per_of_gp_ss,
20018 					   rack->r_ctl.rack_per_of_gp_ca,
20019 					   rack->r_ctl.rack_per_of_gp_rec, 0, 0, 1,
20020 					   __LINE__, NULL, 0);
20021 		break;
20022 	case TCP_RACK_RR_CONF:
20023 		RACK_OPTS_INC(tcp_rack_rrr_no_conf_rate);
20024 		if (optval && optval <= 3)
20025 			rack->r_rr_config = optval;
20026 		else
20027 			rack->r_rr_config = 0;
20028 		break;
20029 	case TCP_HDWR_RATE_CAP:
20030 		RACK_OPTS_INC(tcp_hdwr_rate_cap);
20031 		if (optval) {
20032 			if (rack->r_rack_hw_rate_caps == 0)
20033 				rack->r_rack_hw_rate_caps = 1;
20034 			else
20035 				error = EALREADY;
20036 		} else {
20037 			rack->r_rack_hw_rate_caps = 0;
20038 		}
20039 		break;
20040 	case TCP_BBR_HDWR_PACE:
20041 		RACK_OPTS_INC(tcp_hdwr_pacing);
20042 		if (optval){
20043 			if (rack->rack_hdrw_pacing == 0) {
20044 				rack->rack_hdw_pace_ena = 1;
20045 				rack->rack_attempt_hdwr_pace = 0;
20046 			} else
20047 				error = EALREADY;
20048 		} else {
20049 			rack->rack_hdw_pace_ena = 0;
20050 #ifdef RATELIMIT
20051 			if (rack->r_ctl.crte != NULL) {
20052 				rack->rack_hdrw_pacing = 0;
20053 				rack->rack_attempt_hdwr_pace = 0;
20054 				tcp_rel_pacing_rate(rack->r_ctl.crte, tp);
20055 				rack->r_ctl.crte = NULL;
20056 			}
20057 #endif
20058 		}
20059 		break;
20060 	/*  End Pacing related ones */
20061 	case TCP_RACK_PRR_SENDALOT:
20062 		/* Allow PRR to send more than one seg */
20063 		RACK_OPTS_INC(tcp_rack_prr_sendalot);
20064 		rack->r_ctl.rc_prr_sendalot = optval;
20065 		break;
20066 	case TCP_RACK_MIN_TO:
20067 		/* Minimum time between rack t-o's in ms */
20068 		RACK_OPTS_INC(tcp_rack_min_to);
20069 		rack->r_ctl.rc_min_to = optval;
20070 		break;
20071 	case TCP_RACK_EARLY_SEG:
20072 		/* If early recovery max segments */
20073 		RACK_OPTS_INC(tcp_rack_early_seg);
20074 		rack->r_ctl.rc_early_recovery_segs = optval;
20075 		break;
20076 	case TCP_RACK_ENABLE_HYSTART:
20077 	{
20078 		struct sockopt sopt;
20079 		struct cc_newreno_opts opt;
20080 
20081 		sopt.sopt_valsize = sizeof(struct cc_newreno_opts);
20082 		sopt.sopt_dir = SOPT_SET;
20083 		opt.name = CC_NEWRENO_ENABLE_HYSTART;
20084 		opt.val = optval;
20085 		if (CC_ALGO(tp)->ctl_output != NULL)
20086 			error = CC_ALGO(tp)->ctl_output(tp->ccv, &sopt, &opt);
20087 		else
20088 			error = EINVAL;
20089 	}
20090 	break;
20091 	case TCP_RACK_REORD_THRESH:
20092 		/* RACK reorder threshold (shift amount) */
20093 		RACK_OPTS_INC(tcp_rack_reord_thresh);
20094 		if ((optval > 0) && (optval < 31))
20095 			rack->r_ctl.rc_reorder_shift = optval;
20096 		else
20097 			error = EINVAL;
20098 		break;
20099 	case TCP_RACK_REORD_FADE:
20100 		/* Does reordering fade after ms time */
20101 		RACK_OPTS_INC(tcp_rack_reord_fade);
20102 		rack->r_ctl.rc_reorder_fade = optval;
20103 		break;
20104 	case TCP_RACK_TLP_THRESH:
20105 		/* RACK TLP theshold i.e. srtt+(srtt/N) */
20106 		RACK_OPTS_INC(tcp_rack_tlp_thresh);
20107 		if (optval)
20108 			rack->r_ctl.rc_tlp_threshold = optval;
20109 		else
20110 			error = EINVAL;
20111 		break;
20112 	case TCP_BBR_USE_RACK_RR:
20113 		RACK_OPTS_INC(tcp_rack_rr);
20114 		if (optval)
20115 			rack->use_rack_rr = 1;
20116 		else
20117 			rack->use_rack_rr = 0;
20118 		break;
20119 	case TCP_FAST_RSM_HACK:
20120 		RACK_OPTS_INC(tcp_rack_fastrsm_hack);
20121 		if (optval)
20122 			rack->fast_rsm_hack = 1;
20123 		else
20124 			rack->fast_rsm_hack = 0;
20125 		break;
20126 	case TCP_RACK_PKT_DELAY:
20127 		/* RACK added ms i.e. rack-rtt + reord + N */
20128 		RACK_OPTS_INC(tcp_rack_pkt_delay);
20129 		rack->r_ctl.rc_pkt_delay = optval;
20130 		break;
20131 	case TCP_DELACK:
20132 		RACK_OPTS_INC(tcp_rack_delayed_ack);
20133 		if (optval == 0)
20134 			tp->t_delayed_ack = 0;
20135 		else
20136 			tp->t_delayed_ack = 1;
20137 		if (tp->t_flags & TF_DELACK) {
20138 			tp->t_flags &= ~TF_DELACK;
20139 			tp->t_flags |= TF_ACKNOW;
20140 			NET_EPOCH_ENTER(et);
20141 			rack_output(tp);
20142 			NET_EPOCH_EXIT(et);
20143 		}
20144 		break;
20145 
20146 	case TCP_BBR_RACK_RTT_USE:
20147 		RACK_OPTS_INC(tcp_rack_rtt_use);
20148 		if ((optval != USE_RTT_HIGH) &&
20149 		    (optval != USE_RTT_LOW) &&
20150 		    (optval != USE_RTT_AVG))
20151 			error = EINVAL;
20152 		else
20153 			rack->r_ctl.rc_rate_sample_method = optval;
20154 		break;
20155 	case TCP_DATA_AFTER_CLOSE:
20156 		RACK_OPTS_INC(tcp_data_after_close);
20157 		if (optval)
20158 			rack->rc_allow_data_af_clo = 1;
20159 		else
20160 			rack->rc_allow_data_af_clo = 0;
20161 		break;
20162 	default:
20163 		break;
20164 	}
20165 #ifdef NETFLIX_STATS
20166 	tcp_log_socket_option(tp, sopt_name, optval, error);
20167 #endif
20168 	return (error);
20169 }
20170 
20171 
20172 static void
20173 rack_apply_deferred_options(struct tcp_rack *rack)
20174 {
20175 	struct deferred_opt_list *dol, *sdol;
20176 	uint32_t s_optval;
20177 
20178 	TAILQ_FOREACH_SAFE(dol, &rack->r_ctl.opt_list, next, sdol) {
20179 		TAILQ_REMOVE(&rack->r_ctl.opt_list, dol, next);
20180 		/* Disadvantage of deferal is you loose the error return */
20181 		s_optval = (uint32_t)dol->optval;
20182 		(void)rack_process_option(rack->rc_tp, rack, dol->optname, s_optval, dol->optval);
20183 		free(dol, M_TCPDO);
20184 	}
20185 }
20186 
20187 static void
20188 rack_hw_tls_change(struct tcpcb *tp, int chg)
20189 {
20190 	/*
20191 	 * HW tls state has changed.. fix all
20192 	 * rsm's in flight.
20193 	 */
20194 	struct tcp_rack *rack;
20195 	struct rack_sendmap *rsm;
20196 
20197 	rack = (struct tcp_rack *)tp->t_fb_ptr;
20198 	RB_FOREACH(rsm, rack_rb_tree_head, &rack->r_ctl.rc_mtree) {
20199 		if (chg)
20200 			rsm->r_hw_tls = 1;
20201 		else
20202 			rsm->r_hw_tls = 0;
20203 	}
20204 	if (chg)
20205 		rack->r_ctl.fsb.hw_tls = 1;
20206 	else
20207 		rack->r_ctl.fsb.hw_tls = 0;
20208 }
20209 
20210 static int
20211 rack_pru_options(struct tcpcb *tp, int flags)
20212 {
20213 	if (flags & PRUS_OOB)
20214 		return (EOPNOTSUPP);
20215 	return (0);
20216 }
20217 
20218 static struct tcp_function_block __tcp_rack = {
20219 	.tfb_tcp_block_name = __XSTRING(STACKNAME),
20220 	.tfb_tcp_output = rack_output,
20221 	.tfb_do_queued_segments = ctf_do_queued_segments,
20222 	.tfb_do_segment_nounlock = rack_do_segment_nounlock,
20223 	.tfb_tcp_do_segment = rack_do_segment,
20224 	.tfb_tcp_ctloutput = rack_ctloutput,
20225 	.tfb_tcp_fb_init = rack_init,
20226 	.tfb_tcp_fb_fini = rack_fini,
20227 	.tfb_tcp_timer_stop_all = rack_stopall,
20228 	.tfb_tcp_timer_activate = rack_timer_activate,
20229 	.tfb_tcp_timer_active = rack_timer_active,
20230 	.tfb_tcp_timer_stop = rack_timer_stop,
20231 	.tfb_tcp_rexmit_tmr = rack_remxt_tmr,
20232 	.tfb_tcp_handoff_ok = rack_handoff_ok,
20233 	.tfb_tcp_mtu_chg = rack_mtu_change,
20234 	.tfb_pru_options = rack_pru_options,
20235 	.tfb_hwtls_change = rack_hw_tls_change,
20236 };
20237 
20238 /*
20239  * rack_ctloutput() must drop the inpcb lock before performing copyin on
20240  * socket option arguments.  When it re-acquires the lock after the copy, it
20241  * has to revalidate that the connection is still valid for the socket
20242  * option.
20243  */
20244 static int
20245 rack_set_sockopt(struct socket *so, struct sockopt *sopt,
20246     struct inpcb *inp, struct tcpcb *tp, struct tcp_rack *rack)
20247 {
20248 	uint64_t loptval;
20249 	int32_t error = 0, optval;
20250 
20251 	switch (sopt->sopt_name) {
20252 	case TCP_RACK_TLP_REDUCE:		/*  URL:tlp_reduce */
20253 	/*  Pacing related ones */
20254 	case TCP_RACK_PACE_ALWAYS:		/*  URL:pace_always */
20255 	case TCP_BBR_RACK_INIT_RATE:		/*  URL:irate */
20256 	case TCP_BBR_IWINTSO:			/*  URL:tso_iwin */
20257 	case TCP_RACK_PACE_MAX_SEG:		/*  URL:pace_max_seg */
20258 	case TCP_RACK_FORCE_MSEG:		/*  URL:force_max_seg */
20259 	case TCP_RACK_PACE_RATE_CA:		/*  URL:pr_ca */
20260 	case TCP_RACK_PACE_RATE_SS:		/*  URL:pr_ss*/
20261 	case TCP_RACK_PACE_RATE_REC:		/*  URL:pr_rec */
20262 	case TCP_RACK_GP_INCREASE_CA:		/*  URL:gp_inc_ca */
20263 	case TCP_RACK_GP_INCREASE_SS:		/*  URL:gp_inc_ss */
20264 	case TCP_RACK_GP_INCREASE_REC:		/*  URL:gp_inc_rec */
20265 	case TCP_RACK_RR_CONF:			/*  URL:rrr_conf */
20266 	case TCP_BBR_HDWR_PACE:			/*  URL:hdwrpace */
20267 	case TCP_HDWR_RATE_CAP:			/*  URL:hdwrcap boolean */
20268 	case TCP_PACING_RATE_CAP:		/*  URL:cap  -- used by side-channel */
20269 	case TCP_HDWR_UP_ONLY:			/*  URL:uponly -- hardware pacing  boolean */
20270        /* End pacing related */
20271 	case TCP_FAST_RSM_HACK:			/*  URL:frsm_hack */
20272 	case TCP_DELACK:			/*  URL:delack (in base TCP i.e. tcp_hints along with cc etc ) */
20273 	case TCP_RACK_PRR_SENDALOT:		/*  URL:prr_sendalot */
20274 	case TCP_RACK_MIN_TO:			/*  URL:min_to */
20275 	case TCP_RACK_EARLY_SEG:		/*  URL:early_seg */
20276 	case TCP_RACK_REORD_THRESH:		/*  URL:reord_thresh */
20277 	case TCP_RACK_REORD_FADE:		/*  URL:reord_fade */
20278 	case TCP_RACK_TLP_THRESH:		/*  URL:tlp_thresh */
20279 	case TCP_RACK_PKT_DELAY:		/*  URL:pkt_delay */
20280 	case TCP_RACK_TLP_USE:			/*  URL:tlp_use */
20281 	case TCP_BBR_RACK_RTT_USE:		/*  URL:rttuse */
20282 	case TCP_BBR_USE_RACK_RR:		/*  URL:rackrr */
20283 	case TCP_RACK_DO_DETECTION:		/*  URL:detect */
20284 	case TCP_NO_PRR:			/*  URL:noprr */
20285 	case TCP_TIMELY_DYN_ADJ:      		/*  URL:dynamic */
20286 	case TCP_DATA_AFTER_CLOSE:		/*  no URL */
20287 	case TCP_RACK_NONRXT_CFG_RATE:		/*  URL:nonrxtcr */
20288 	case TCP_SHARED_CWND_ENABLE:		/*  URL:scwnd */
20289 	case TCP_RACK_MBUF_QUEUE:		/*  URL:mqueue */
20290 	case TCP_RACK_NO_PUSH_AT_MAX:		/*  URL:npush */
20291 	case TCP_RACK_PACE_TO_FILL:		/*  URL:fillcw */
20292 	case TCP_SHARED_CWND_TIME_LIMIT:	/*  URL:lscwnd */
20293 	case TCP_RACK_PROFILE:			/*  URL:profile */
20294 	case TCP_USE_CMP_ACKS:			/*  URL:cmpack */
20295 	case TCP_RACK_ABC_VAL:			/*  URL:labc */
20296 	case TCP_REC_ABC_VAL:			/*  URL:reclabc */
20297 	case TCP_RACK_MEASURE_CNT:		/*  URL:measurecnt */
20298 	case TCP_DEFER_OPTIONS:			/*  URL:defer */
20299 	case TCP_RACK_DSACK_OPT:		/*  URL:dsack */
20300 	case TCP_RACK_PACING_BETA:		/*  URL:pacing_beta */
20301 	case TCP_RACK_PACING_BETA_ECN:		/*  URL:pacing_beta_ecn */
20302 	case TCP_RACK_TIMER_SLOP:		/*  URL:timer_slop */
20303 	case TCP_RACK_ENABLE_HYSTART:		/*  URL:hystart */
20304 		break;
20305 	default:
20306 		/* Filter off all unknown options to the base stack */
20307 		return (tcp_default_ctloutput(so, sopt, inp, tp));
20308 		break;
20309 	}
20310 	INP_WUNLOCK(inp);
20311 	if (sopt->sopt_name == TCP_PACING_RATE_CAP) {
20312 		error = sooptcopyin(sopt, &loptval, sizeof(loptval), sizeof(loptval));
20313 		/*
20314 		 * We truncate it down to 32 bits for the socket-option trace this
20315 		 * means rates > 34Gbps won't show right, but thats probably ok.
20316 		 */
20317 		optval = (uint32_t)loptval;
20318 	} else {
20319 		error = sooptcopyin(sopt, &optval, sizeof(optval), sizeof(optval));
20320 		/* Save it in 64 bit form too */
20321 		loptval = optval;
20322 	}
20323 	if (error)
20324 		return (error);
20325 	INP_WLOCK(inp);
20326 	if (inp->inp_flags & (INP_TIMEWAIT | INP_DROPPED)) {
20327 		INP_WUNLOCK(inp);
20328 		return (ECONNRESET);
20329 	}
20330 	if (tp->t_fb != &__tcp_rack) {
20331 		INP_WUNLOCK(inp);
20332 		return (ENOPROTOOPT);
20333 	}
20334 	if (rack->defer_options && (rack->gp_ready == 0) &&
20335 	    (sopt->sopt_name != TCP_DEFER_OPTIONS) &&
20336 	    (sopt->sopt_name != TCP_RACK_PACING_BETA) &&
20337 	    (sopt->sopt_name != TCP_RACK_PACING_BETA_ECN) &&
20338 	    (sopt->sopt_name != TCP_RACK_MEASURE_CNT)) {
20339 		/* Options are beind deferred */
20340 		if (rack_add_deferred_option(rack, sopt->sopt_name, loptval)) {
20341 			INP_WUNLOCK(inp);
20342 			return (0);
20343 		} else {
20344 			/* No memory to defer, fail */
20345 			INP_WUNLOCK(inp);
20346 			return (ENOMEM);
20347 		}
20348 	}
20349 	error = rack_process_option(tp, rack, sopt->sopt_name, optval, loptval);
20350 	INP_WUNLOCK(inp);
20351 	return (error);
20352 }
20353 
20354 static void
20355 rack_fill_info(struct tcpcb *tp, struct tcp_info *ti)
20356 {
20357 
20358 	INP_WLOCK_ASSERT(tp->t_inpcb);
20359 	bzero(ti, sizeof(*ti));
20360 
20361 	ti->tcpi_state = tp->t_state;
20362 	if ((tp->t_flags & TF_REQ_TSTMP) && (tp->t_flags & TF_RCVD_TSTMP))
20363 		ti->tcpi_options |= TCPI_OPT_TIMESTAMPS;
20364 	if (tp->t_flags & TF_SACK_PERMIT)
20365 		ti->tcpi_options |= TCPI_OPT_SACK;
20366 	if ((tp->t_flags & TF_REQ_SCALE) && (tp->t_flags & TF_RCVD_SCALE)) {
20367 		ti->tcpi_options |= TCPI_OPT_WSCALE;
20368 		ti->tcpi_snd_wscale = tp->snd_scale;
20369 		ti->tcpi_rcv_wscale = tp->rcv_scale;
20370 	}
20371 	if (tp->t_flags2 & TF2_ECN_PERMIT)
20372 		ti->tcpi_options |= TCPI_OPT_ECN;
20373 	if (tp->t_flags & TF_FASTOPEN)
20374 		ti->tcpi_options |= TCPI_OPT_TFO;
20375 	/* still kept in ticks is t_rcvtime */
20376 	ti->tcpi_last_data_recv = ((uint32_t)ticks - tp->t_rcvtime) * tick;
20377 	/* Since we hold everything in precise useconds this is easy */
20378 	ti->tcpi_rtt = tp->t_srtt;
20379 	ti->tcpi_rttvar = tp->t_rttvar;
20380 	ti->tcpi_rto = tp->t_rxtcur;
20381 	ti->tcpi_snd_ssthresh = tp->snd_ssthresh;
20382 	ti->tcpi_snd_cwnd = tp->snd_cwnd;
20383 	/*
20384 	 * FreeBSD-specific extension fields for tcp_info.
20385 	 */
20386 	ti->tcpi_rcv_space = tp->rcv_wnd;
20387 	ti->tcpi_rcv_nxt = tp->rcv_nxt;
20388 	ti->tcpi_snd_wnd = tp->snd_wnd;
20389 	ti->tcpi_snd_bwnd = 0;		/* Unused, kept for compat. */
20390 	ti->tcpi_snd_nxt = tp->snd_nxt;
20391 	ti->tcpi_snd_mss = tp->t_maxseg;
20392 	ti->tcpi_rcv_mss = tp->t_maxseg;
20393 	ti->tcpi_snd_rexmitpack = tp->t_sndrexmitpack;
20394 	ti->tcpi_rcv_ooopack = tp->t_rcvoopack;
20395 	ti->tcpi_snd_zerowin = tp->t_sndzerowin;
20396 #ifdef NETFLIX_STATS
20397 	ti->tcpi_total_tlp = tp->t_sndtlppack;
20398 	ti->tcpi_total_tlp_bytes = tp->t_sndtlpbyte;
20399 	memcpy(&ti->tcpi_rxsyninfo, &tp->t_rxsyninfo, sizeof(struct tcpsyninfo));
20400 #endif
20401 #ifdef TCP_OFFLOAD
20402 	if (tp->t_flags & TF_TOE) {
20403 		ti->tcpi_options |= TCPI_OPT_TOE;
20404 		tcp_offload_tcp_info(tp, ti);
20405 	}
20406 #endif
20407 }
20408 
20409 static int
20410 rack_get_sockopt(struct socket *so, struct sockopt *sopt,
20411     struct inpcb *inp, struct tcpcb *tp, struct tcp_rack *rack)
20412 {
20413 	int32_t error, optval;
20414 	uint64_t val, loptval;
20415 	struct	tcp_info ti;
20416 	/*
20417 	 * Because all our options are either boolean or an int, we can just
20418 	 * pull everything into optval and then unlock and copy. If we ever
20419 	 * add a option that is not a int, then this will have quite an
20420 	 * impact to this routine.
20421 	 */
20422 	error = 0;
20423 	switch (sopt->sopt_name) {
20424 	case TCP_INFO:
20425 		/* First get the info filled */
20426 		rack_fill_info(tp, &ti);
20427 		/* Fix up the rtt related fields if needed */
20428 		INP_WUNLOCK(inp);
20429 		error = sooptcopyout(sopt, &ti, sizeof ti);
20430 		return (error);
20431 	/*
20432 	 * Beta is the congestion control value for NewReno that influences how
20433 	 * much of a backoff happens when loss is detected. It is normally set
20434 	 * to 50 for 50% i.e. the cwnd is reduced to 50% of its previous value
20435 	 * when you exit recovery.
20436 	 */
20437 	case TCP_RACK_PACING_BETA:
20438 		if (strcmp(tp->cc_algo->name, CCALGONAME_NEWRENO) != 0)
20439 			error = EINVAL;
20440 		else if (rack->rc_pacing_cc_set == 0)
20441 			optval = rack->r_ctl.rc_saved_beta.beta;
20442 		else {
20443 			/*
20444 			 * Reach out into the CC data and report back what
20445 			 * I have previously set. Yeah it looks hackish but
20446 			 * we don't want to report the saved values.
20447 			 */
20448 			if (tp->ccv->cc_data)
20449 				optval = ((struct newreno *)tp->ccv->cc_data)->beta;
20450 			else
20451 				error = EINVAL;
20452 		}
20453 		break;
20454 		/*
20455 		 * Beta_ecn is the congestion control value for NewReno that influences how
20456 		 * much of a backoff happens when a ECN mark is detected. It is normally set
20457 		 * to 80 for 80% i.e. the cwnd is reduced by 20% of its previous value when
20458 		 * you exit recovery. Note that classic ECN has a beta of 50, it is only
20459 		 * ABE Ecn that uses this "less" value, but we do too with pacing :)
20460 		 */
20461 
20462 	case TCP_RACK_PACING_BETA_ECN:
20463 		if (strcmp(tp->cc_algo->name, CCALGONAME_NEWRENO) != 0)
20464 			error = EINVAL;
20465 		else if (rack->rc_pacing_cc_set == 0)
20466 			optval = rack->r_ctl.rc_saved_beta.beta_ecn;
20467 		else {
20468 			/*
20469 			 * Reach out into the CC data and report back what
20470 			 * I have previously set. Yeah it looks hackish but
20471 			 * we don't want to report the saved values.
20472 			 */
20473 			if (tp->ccv->cc_data)
20474 				optval = ((struct newreno *)tp->ccv->cc_data)->beta_ecn;
20475 			else
20476 				error = EINVAL;
20477 		}
20478 		break;
20479 	case TCP_RACK_DSACK_OPT:
20480 		optval = 0;
20481 		if (rack->rc_rack_tmr_std_based) {
20482 			optval |= 1;
20483 		}
20484 		if (rack->rc_rack_use_dsack) {
20485 			optval |= 2;
20486 		}
20487 		break;
20488  	case TCP_RACK_ENABLE_HYSTART:
20489 	{
20490 		struct sockopt sopt;
20491 		struct cc_newreno_opts opt;
20492 
20493 		sopt.sopt_valsize = sizeof(struct cc_newreno_opts);
20494 		sopt.sopt_dir = SOPT_GET;
20495 		opt.name = CC_NEWRENO_ENABLE_HYSTART;
20496 		if (CC_ALGO(tp)->ctl_output != NULL)
20497 			error = CC_ALGO(tp)->ctl_output(tp->ccv, &sopt, &opt);
20498 		else
20499 			error = EINVAL;
20500 		optval = opt.val;
20501 	}
20502 	break;
20503 	case TCP_FAST_RSM_HACK:
20504 		optval = rack->fast_rsm_hack;
20505 		break;
20506 	case TCP_DEFER_OPTIONS:
20507 		optval = rack->defer_options;
20508 		break;
20509 	case TCP_RACK_MEASURE_CNT:
20510 		optval = rack->r_ctl.req_measurements;
20511 		break;
20512 	case TCP_REC_ABC_VAL:
20513 		optval = rack->r_use_labc_for_rec;
20514 		break;
20515 	case TCP_RACK_ABC_VAL:
20516 		optval = rack->rc_labc;
20517 		break;
20518 	case TCP_HDWR_UP_ONLY:
20519 		optval= rack->r_up_only;
20520 		break;
20521 	case TCP_PACING_RATE_CAP:
20522 		loptval = rack->r_ctl.bw_rate_cap;
20523 		break;
20524 	case TCP_RACK_PROFILE:
20525 		/* You cannot retrieve a profile, its write only */
20526 		error = EINVAL;
20527 		break;
20528 	case TCP_USE_CMP_ACKS:
20529 		optval = rack->r_use_cmp_ack;
20530 		break;
20531 	case TCP_RACK_PACE_TO_FILL:
20532 		optval = rack->rc_pace_to_cwnd;
20533 		if (optval && rack->r_fill_less_agg)
20534 			optval++;
20535 		break;
20536 	case TCP_RACK_NO_PUSH_AT_MAX:
20537 		optval = rack->r_ctl.rc_no_push_at_mrtt;
20538 		break;
20539 	case TCP_SHARED_CWND_ENABLE:
20540 		optval = rack->rack_enable_scwnd;
20541 		break;
20542 	case TCP_RACK_NONRXT_CFG_RATE:
20543 		optval = rack->rack_rec_nonrxt_use_cr;
20544 		break;
20545 	case TCP_NO_PRR:
20546 		if (rack->rack_no_prr  == 1)
20547 			optval = 1;
20548 		else if (rack->no_prr_addback == 1)
20549 			optval = 2;
20550 		else
20551 			optval = 0;
20552 		break;
20553 	case TCP_RACK_DO_DETECTION:
20554 		optval = rack->do_detection;
20555 		break;
20556 	case TCP_RACK_MBUF_QUEUE:
20557 		/* Now do we use the LRO mbuf-queue feature */
20558 		optval = rack->r_mbuf_queue;
20559 		break;
20560 	case TCP_TIMELY_DYN_ADJ:
20561 		optval = rack->rc_gp_dyn_mul;
20562 		break;
20563 	case TCP_BBR_IWINTSO:
20564 		optval = rack->rc_init_win;
20565 		break;
20566 	case TCP_RACK_TLP_REDUCE:
20567 		/* RACK TLP cwnd reduction (bool) */
20568 		optval = rack->r_ctl.rc_tlp_cwnd_reduce;
20569 		break;
20570 	case TCP_BBR_RACK_INIT_RATE:
20571 		val = rack->r_ctl.init_rate;
20572 		/* convert to kbits per sec */
20573 		val *= 8;
20574 		val /= 1000;
20575 		optval = (uint32_t)val;
20576 		break;
20577 	case TCP_RACK_FORCE_MSEG:
20578 		optval = rack->rc_force_max_seg;
20579 		break;
20580 	case TCP_RACK_PACE_MAX_SEG:
20581 		/* Max segments in a pace */
20582 		optval = rack->rc_user_set_max_segs;
20583 		break;
20584 	case TCP_RACK_PACE_ALWAYS:
20585 		/* Use the always pace method */
20586 		optval = rack->rc_always_pace;
20587 		break;
20588 	case TCP_RACK_PRR_SENDALOT:
20589 		/* Allow PRR to send more than one seg */
20590 		optval = rack->r_ctl.rc_prr_sendalot;
20591 		break;
20592 	case TCP_RACK_MIN_TO:
20593 		/* Minimum time between rack t-o's in ms */
20594 		optval = rack->r_ctl.rc_min_to;
20595 		break;
20596 	case TCP_RACK_EARLY_SEG:
20597 		/* If early recovery max segments */
20598 		optval = rack->r_ctl.rc_early_recovery_segs;
20599 		break;
20600 	case TCP_RACK_REORD_THRESH:
20601 		/* RACK reorder threshold (shift amount) */
20602 		optval = rack->r_ctl.rc_reorder_shift;
20603 		break;
20604 	case TCP_RACK_REORD_FADE:
20605 		/* Does reordering fade after ms time */
20606 		optval = rack->r_ctl.rc_reorder_fade;
20607 		break;
20608 	case TCP_BBR_USE_RACK_RR:
20609 		/* Do we use the rack cheat for rxt */
20610 		optval = rack->use_rack_rr;
20611 		break;
20612 	case TCP_RACK_RR_CONF:
20613 		optval = rack->r_rr_config;
20614 		break;
20615 	case TCP_HDWR_RATE_CAP:
20616 		optval = rack->r_rack_hw_rate_caps;
20617 		break;
20618 	case TCP_BBR_HDWR_PACE:
20619 		optval = rack->rack_hdw_pace_ena;
20620 		break;
20621 	case TCP_RACK_TLP_THRESH:
20622 		/* RACK TLP theshold i.e. srtt+(srtt/N) */
20623 		optval = rack->r_ctl.rc_tlp_threshold;
20624 		break;
20625 	case TCP_RACK_PKT_DELAY:
20626 		/* RACK added ms i.e. rack-rtt + reord + N */
20627 		optval = rack->r_ctl.rc_pkt_delay;
20628 		break;
20629 	case TCP_RACK_TLP_USE:
20630 		optval = rack->rack_tlp_threshold_use;
20631 		break;
20632 	case TCP_RACK_PACE_RATE_CA:
20633 		optval = rack->r_ctl.rc_fixed_pacing_rate_ca;
20634 		break;
20635 	case TCP_RACK_PACE_RATE_SS:
20636 		optval = rack->r_ctl.rc_fixed_pacing_rate_ss;
20637 		break;
20638 	case TCP_RACK_PACE_RATE_REC:
20639 		optval = rack->r_ctl.rc_fixed_pacing_rate_rec;
20640 		break;
20641 	case TCP_RACK_GP_INCREASE_SS:
20642 		optval = rack->r_ctl.rack_per_of_gp_ca;
20643 		break;
20644 	case TCP_RACK_GP_INCREASE_CA:
20645 		optval = rack->r_ctl.rack_per_of_gp_ss;
20646 		break;
20647 	case TCP_BBR_RACK_RTT_USE:
20648 		optval = rack->r_ctl.rc_rate_sample_method;
20649 		break;
20650 	case TCP_DELACK:
20651 		optval = tp->t_delayed_ack;
20652 		break;
20653 	case TCP_DATA_AFTER_CLOSE:
20654 		optval = rack->rc_allow_data_af_clo;
20655 		break;
20656 	case TCP_SHARED_CWND_TIME_LIMIT:
20657 		optval = rack->r_limit_scw;
20658 		break;
20659 	case TCP_RACK_TIMER_SLOP:
20660 		optval = rack->r_ctl.timer_slop;
20661 		break;
20662 	default:
20663 		return (tcp_default_ctloutput(so, sopt, inp, tp));
20664 		break;
20665 	}
20666 	INP_WUNLOCK(inp);
20667 	if (error == 0) {
20668 		if (TCP_PACING_RATE_CAP)
20669 			error = sooptcopyout(sopt, &loptval, sizeof loptval);
20670 		else
20671 			error = sooptcopyout(sopt, &optval, sizeof optval);
20672 	}
20673 	return (error);
20674 }
20675 
20676 static int
20677 rack_ctloutput(struct socket *so, struct sockopt *sopt, struct inpcb *inp, struct tcpcb *tp)
20678 {
20679 	int32_t error = EINVAL;
20680 	struct tcp_rack *rack;
20681 
20682 	rack = (struct tcp_rack *)tp->t_fb_ptr;
20683 	if (rack == NULL) {
20684 		/* Huh? */
20685 		goto out;
20686 	}
20687 	if (sopt->sopt_dir == SOPT_SET) {
20688 		return (rack_set_sockopt(so, sopt, inp, tp, rack));
20689 	} else if (sopt->sopt_dir == SOPT_GET) {
20690 		return (rack_get_sockopt(so, sopt, inp, tp, rack));
20691 	}
20692 out:
20693 	INP_WUNLOCK(inp);
20694 	return (error);
20695 }
20696 
20697 static const char *rack_stack_names[] = {
20698 	__XSTRING(STACKNAME),
20699 #ifdef STACKALIAS
20700 	__XSTRING(STACKALIAS),
20701 #endif
20702 };
20703 
20704 static int
20705 rack_ctor(void *mem, int32_t size, void *arg, int32_t how)
20706 {
20707 	memset(mem, 0, size);
20708 	return (0);
20709 }
20710 
20711 static void
20712 rack_dtor(void *mem, int32_t size, void *arg)
20713 {
20714 
20715 }
20716 
20717 static bool rack_mod_inited = false;
20718 
20719 static int
20720 tcp_addrack(module_t mod, int32_t type, void *data)
20721 {
20722 	int32_t err = 0;
20723 	int num_stacks;
20724 
20725 	switch (type) {
20726 	case MOD_LOAD:
20727 		rack_zone = uma_zcreate(__XSTRING(MODNAME) "_map",
20728 		    sizeof(struct rack_sendmap),
20729 		    rack_ctor, rack_dtor, NULL, NULL, UMA_ALIGN_PTR, 0);
20730 
20731 		rack_pcb_zone = uma_zcreate(__XSTRING(MODNAME) "_pcb",
20732 		    sizeof(struct tcp_rack),
20733 		    rack_ctor, NULL, NULL, NULL, UMA_ALIGN_CACHE, 0);
20734 
20735 		sysctl_ctx_init(&rack_sysctl_ctx);
20736 		rack_sysctl_root = SYSCTL_ADD_NODE(&rack_sysctl_ctx,
20737 		    SYSCTL_STATIC_CHILDREN(_net_inet_tcp),
20738 		    OID_AUTO,
20739 #ifdef STACKALIAS
20740 		    __XSTRING(STACKALIAS),
20741 #else
20742 		    __XSTRING(STACKNAME),
20743 #endif
20744 		    CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
20745 		    "");
20746 		if (rack_sysctl_root == NULL) {
20747 			printf("Failed to add sysctl node\n");
20748 			err = EFAULT;
20749 			goto free_uma;
20750 		}
20751 		rack_init_sysctls();
20752 		num_stacks = nitems(rack_stack_names);
20753 		err = register_tcp_functions_as_names(&__tcp_rack, M_WAITOK,
20754 		    rack_stack_names, &num_stacks);
20755 		if (err) {
20756 			printf("Failed to register %s stack name for "
20757 			    "%s module\n", rack_stack_names[num_stacks],
20758 			    __XSTRING(MODNAME));
20759 			sysctl_ctx_free(&rack_sysctl_ctx);
20760 free_uma:
20761 			uma_zdestroy(rack_zone);
20762 			uma_zdestroy(rack_pcb_zone);
20763 			rack_counter_destroy();
20764 			printf("Failed to register rack module -- err:%d\n", err);
20765 			return (err);
20766 		}
20767 		tcp_lro_reg_mbufq();
20768 		rack_mod_inited = true;
20769 		break;
20770 	case MOD_QUIESCE:
20771 		err = deregister_tcp_functions(&__tcp_rack, true, false);
20772 		break;
20773 	case MOD_UNLOAD:
20774 		err = deregister_tcp_functions(&__tcp_rack, false, true);
20775 		if (err == EBUSY)
20776 			break;
20777 		if (rack_mod_inited) {
20778 			uma_zdestroy(rack_zone);
20779 			uma_zdestroy(rack_pcb_zone);
20780 			sysctl_ctx_free(&rack_sysctl_ctx);
20781 			rack_counter_destroy();
20782 			rack_mod_inited = false;
20783 		}
20784 		tcp_lro_dereg_mbufq();
20785 		err = 0;
20786 		break;
20787 	default:
20788 		return (EOPNOTSUPP);
20789 	}
20790 	return (err);
20791 }
20792 
20793 static moduledata_t tcp_rack = {
20794 	.name = __XSTRING(MODNAME),
20795 	.evhand = tcp_addrack,
20796 	.priv = 0
20797 };
20798 
20799 MODULE_VERSION(MODNAME, 1);
20800 DECLARE_MODULE(MODNAME, tcp_rack, SI_SUB_PROTO_DOMAIN, SI_ORDER_ANY);
20801 MODULE_DEPEND(MODNAME, tcphpts, 1, 1, 1);
20802