xref: /freebsd/sys/netinet/tcp_stacks/rack.c (revision be181ee2) 
1 /*-
2  * Copyright (c) 2016-2020 Netflix, Inc.
3  *
4  * Redistribution and use in source and binary forms, with or without
5  * modification, are permitted provided that the following conditions
6  * are met:
7  * 1. Redistributions of source code must retain the above copyright
8  *    notice, this list of conditions and the following disclaimer.
9  * 2. Redistributions in binary form must reproduce the above copyright
10  *    notice, this list of conditions and the following disclaimer in the
11  *    documentation and/or other materials provided with the distribution.
12  *
13  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
14  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
15  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
16  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
17  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
18  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
19  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
20  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
21  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
22  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
23  * SUCH DAMAGE.
24  *
25  */
26 
27 #include <sys/cdefs.h>
28 __FBSDID("$FreeBSD$");
29 
30 #include "opt_inet.h"
31 #include "opt_inet6.h"
32 #include "opt_ipsec.h"
33 #include "opt_tcpdebug.h"
34 #include "opt_ratelimit.h"
35 #include "opt_kern_tls.h"
36 #include <sys/param.h>
37 #include <sys/arb.h>
38 #include <sys/module.h>
39 #include <sys/kernel.h>
40 #ifdef TCP_HHOOK
41 #include <sys/hhook.h>
42 #endif
43 #include <sys/lock.h>
44 #include <sys/malloc.h>
45 #include <sys/lock.h>
46 #include <sys/mutex.h>
47 #include <sys/mbuf.h>
48 #include <sys/proc.h>		/* for proc0 declaration */
49 #include <sys/socket.h>
50 #include <sys/socketvar.h>
51 #include <sys/sysctl.h>
52 #include <sys/systm.h>
53 #ifdef STATS
54 #include <sys/qmath.h>
55 #include <sys/tree.h>
56 #include <sys/stats.h> /* Must come after qmath.h and tree.h */
57 #else
58 #include <sys/tree.h>
59 #endif
60 #include <sys/refcount.h>
61 #include <sys/queue.h>
62 #include <sys/tim_filter.h>
63 #include <sys/smp.h>
64 #include <sys/kthread.h>
65 #include <sys/kern_prefetch.h>
66 #include <sys/protosw.h>
67 #ifdef TCP_ACCOUNTING
68 #include <sys/sched.h>
69 #include <machine/cpu.h>
70 #endif
71 #include <vm/uma.h>
72 
73 #include <net/route.h>
74 #include <net/route/nhop.h>
75 #include <net/vnet.h>
76 
77 #define TCPSTATES		/* for logging */
78 
79 #include <netinet/in.h>
80 #include <netinet/in_kdtrace.h>
81 #include <netinet/in_pcb.h>
82 #include <netinet/ip.h>
83 #include <netinet/ip_icmp.h>	/* required for icmp_var.h */
84 #include <netinet/icmp_var.h>	/* for ICMP_BANDLIM */
85 #include <netinet/ip_var.h>
86 #include <netinet/ip6.h>
87 #include <netinet6/in6_pcb.h>
88 #include <netinet6/ip6_var.h>
89 #include <netinet/tcp.h>
90 #define	TCPOUTFLAGS
91 #include <netinet/tcp_fsm.h>
92 #include <netinet/tcp_log_buf.h>
93 #include <netinet/tcp_seq.h>
94 #include <netinet/tcp_timer.h>
95 #include <netinet/tcp_var.h>
96 #include <netinet/tcp_syncache.h>
97 #include <netinet/tcp_hpts.h>
98 #include <netinet/tcp_ratelimit.h>
99 #include <netinet/tcp_accounting.h>
100 #include <netinet/tcpip.h>
101 #include <netinet/cc/cc.h>
102 #include <netinet/cc/cc_newreno.h>
103 #include <netinet/tcp_fastopen.h>
104 #include <netinet/tcp_lro.h>
105 #ifdef NETFLIX_SHARED_CWND
106 #include <netinet/tcp_shared_cwnd.h>
107 #endif
108 #ifdef TCPDEBUG
109 #include <netinet/tcp_debug.h>
110 #endif				/* TCPDEBUG */
111 #ifdef TCP_OFFLOAD
112 #include <netinet/tcp_offload.h>
113 #endif
114 #ifdef INET6
115 #include <netinet6/tcp6_var.h>
116 #endif
117 #include <netinet/tcp_ecn.h>
118 
119 #include <netipsec/ipsec_support.h>
120 
121 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
122 #include <netipsec/ipsec.h>
123 #include <netipsec/ipsec6.h>
124 #endif				/* IPSEC */
125 
126 #include <netinet/udp.h>
127 #include <netinet/udp_var.h>
128 #include <machine/in_cksum.h>
129 
130 #ifdef MAC
131 #include <security/mac/mac_framework.h>
132 #endif
133 #include "sack_filter.h"
134 #include "tcp_rack.h"
135 #include "rack_bbr_common.h"
136 
137 uma_zone_t rack_zone;
138 uma_zone_t rack_pcb_zone;
139 
140 #ifndef TICKS2SBT
141 #define	TICKS2SBT(__t)	(tick_sbt * ((sbintime_t)(__t)))
142 #endif
143 
144 VNET_DECLARE(uint32_t, newreno_beta);
145 VNET_DECLARE(uint32_t, newreno_beta_ecn);
146 #define V_newreno_beta VNET(newreno_beta)
147 #define V_newreno_beta_ecn VNET(newreno_beta_ecn)
148 
149 
150 MALLOC_DEFINE(M_TCPFSB, "tcp_fsb", "TCP fast send block");
151 MALLOC_DEFINE(M_TCPDO, "tcp_do", "TCP deferred options");
152 
153 struct sysctl_ctx_list rack_sysctl_ctx;
154 struct sysctl_oid *rack_sysctl_root;
155 
156 #define CUM_ACKED 1
157 #define SACKED 2
158 
159 /*
160  * The RACK module incorporates a number of
161  * TCP ideas that have been put out into the IETF
162  * over the last few years:
163  * - Matt Mathis's Rate Halving which slowly drops
164  *    the congestion window so that the ack clock can
165  *    be maintained during a recovery.
166  * - Yuchung Cheng's RACK TCP (for which its named) that
167  *    will stop us using the number of dup acks and instead
168  *    use time as the gage of when we retransmit.
169  * - Reorder Detection of RFC4737 and the Tail-Loss probe draft
170  *    of Dukkipati et.al.
171  * RACK depends on SACK, so if an endpoint arrives that
172  * cannot do SACK the state machine below will shuttle the
173  * connection back to using the "default" TCP stack that is
174  * in FreeBSD.
175  *
176  * To implement RACK the original TCP stack was first decomposed
177  * into a functional state machine with individual states
178  * for each of the possible TCP connection states. The do_segment
179  * functions role in life is to mandate the connection supports SACK
180  * initially and then assure that the RACK state matches the conenction
181  * state before calling the states do_segment function. Each
182  * state is simplified due to the fact that the original do_segment
183  * has been decomposed and we *know* what state we are in (no
184  * switches on the state) and all tests for SACK are gone. This
185  * greatly simplifies what each state does.
186  *
187  * TCP output is also over-written with a new version since it
188  * must maintain the new rack scoreboard.
189  *
190  */
191 static int32_t rack_tlp_thresh = 1;
192 static int32_t rack_tlp_limit = 2;	/* No more than 2 TLPs w-out new data */
193 static int32_t rack_tlp_use_greater = 1;
194 static int32_t rack_reorder_thresh = 2;
195 static int32_t rack_reorder_fade = 60000000;	/* 0 - never fade, def 60,000,000
196 						 * - 60 seconds */
197 static uint8_t rack_req_measurements = 1;
198 /* Attack threshold detections */
199 static uint32_t rack_highest_sack_thresh_seen = 0;
200 static uint32_t rack_highest_move_thresh_seen = 0;
201 static int32_t rack_enable_hw_pacing = 0; /* Due to CCSP keep it off by default */
202 static int32_t rack_hw_pace_extra_slots = 2;	/* 2 extra MSS time betweens */
203 static int32_t rack_hw_rate_caps = 1; /* 1; */
204 static int32_t rack_hw_rate_min = 0; /* 1500000;*/
205 static int32_t rack_hw_rate_to_low = 0; /* 1200000; */
206 static int32_t rack_hw_up_only = 1;
207 static int32_t rack_stats_gets_ms_rtt = 1;
208 static int32_t rack_prr_addbackmax = 2;
209 static int32_t rack_do_hystart = 0;
210 static int32_t rack_apply_rtt_with_reduced_conf = 0;
211 
212 static int32_t rack_pkt_delay = 1000;
213 static int32_t rack_send_a_lot_in_prr = 1;
214 static int32_t rack_min_to = 1000;	/* Number of microsecond  min timeout */
215 static int32_t rack_verbose_logging = 0;
216 static int32_t rack_ignore_data_after_close = 1;
217 static int32_t rack_enable_shared_cwnd = 1;
218 static int32_t rack_use_cmp_acks = 1;
219 static int32_t rack_use_fsb = 1;
220 static int32_t rack_use_rfo = 1;
221 static int32_t rack_use_rsm_rfo = 1;
222 static int32_t rack_max_abc_post_recovery = 2;
223 static int32_t rack_client_low_buf = 0;
224 static int32_t rack_dsack_std_based = 0x3;	/* bit field bit 1 sets rc_rack_tmr_std_based and bit 2 sets rc_rack_use_dsack */
225 #ifdef TCP_ACCOUNTING
226 static int32_t rack_tcp_accounting = 0;
227 #endif
228 static int32_t rack_limits_scwnd = 1;
229 static int32_t rack_enable_mqueue_for_nonpaced = 0;
230 static int32_t rack_disable_prr = 0;
231 static int32_t use_rack_rr = 1;
232 static int32_t rack_non_rxt_use_cr = 0; /* does a non-rxt in recovery use the configured rate (ss/ca)? */
233 static int32_t rack_persist_min = 250000;	/* 250usec */
234 static int32_t rack_persist_max = 2000000;	/* 2 Second in usec's */
235 static int32_t rack_sack_not_required = 1;	/* set to one to allow non-sack to use rack */
236 static int32_t rack_default_init_window = 0;	/* Use system default */
237 static int32_t rack_limit_time_with_srtt = 0;
238 static int32_t rack_autosndbuf_inc = 20;	/* In percentage form */
239 static int32_t rack_enobuf_hw_boost_mult = 2;	/* How many times the hw rate we boost slot using time_between */
240 static int32_t rack_enobuf_hw_max = 12000;	/* 12 ms in usecs */
241 static int32_t rack_enobuf_hw_min = 10000;	/* 10 ms in usecs */
242 static int32_t rack_hw_rwnd_factor = 2;		/* How many max_segs the rwnd must be before we hold off sending */
243 
244 /*
245  * Currently regular tcp has a rto_min of 30ms
246  * the backoff goes 12 times so that ends up
247  * being a total of 122.850 seconds before a
248  * connection is killed.
249  */
250 static uint32_t rack_def_data_window = 20;
251 static uint32_t rack_goal_bdp = 2;
252 static uint32_t rack_min_srtts = 1;
253 static uint32_t rack_min_measure_usec = 0;
254 static int32_t rack_tlp_min = 10000;	/* 10ms */
255 static int32_t rack_rto_min = 30000;	/* 30,000 usec same as main freebsd */
256 static int32_t rack_rto_max = 4000000;	/* 4 seconds in usec's */
257 static const int32_t rack_free_cache = 2;
258 static int32_t rack_hptsi_segments = 40;
259 static int32_t rack_rate_sample_method = USE_RTT_LOW;
260 static int32_t rack_pace_every_seg = 0;
261 static int32_t rack_delayed_ack_time = 40000;	/* 40ms in usecs */
262 static int32_t rack_slot_reduction = 4;
263 static int32_t rack_wma_divisor = 8;		/* For WMA calculation */
264 static int32_t rack_cwnd_block_ends_measure = 0;
265 static int32_t rack_rwnd_block_ends_measure = 0;
266 static int32_t rack_def_profile = 0;
267 
268 static int32_t rack_lower_cwnd_at_tlp = 0;
269 static int32_t rack_limited_retran = 0;
270 static int32_t rack_always_send_oldest = 0;
271 static int32_t rack_tlp_threshold_use = TLP_USE_TWO_ONE;
272 
273 static uint16_t rack_per_of_gp_ss = 250;	/* 250 % slow-start */
274 static uint16_t rack_per_of_gp_ca = 200;	/* 200 % congestion-avoidance */
275 static uint16_t rack_per_of_gp_rec = 200;	/* 200 % of bw */
276 
277 /* Probertt */
278 static uint16_t rack_per_of_gp_probertt = 60;	/* 60% of bw */
279 static uint16_t rack_per_of_gp_lowthresh = 40;	/* 40% is bottom */
280 static uint16_t rack_per_of_gp_probertt_reduce = 10; /* 10% reduction */
281 static uint16_t rack_atexit_prtt_hbp = 130;	/* Clamp to 130% on exit prtt if highly buffered path */
282 static uint16_t rack_atexit_prtt = 130;	/* Clamp to 100% on exit prtt if non highly buffered path */
283 
284 static uint32_t rack_max_drain_wait = 2;	/* How man gp srtt's before we give up draining */
285 static uint32_t rack_must_drain = 1;		/* How many GP srtt's we *must* wait */
286 static uint32_t rack_probertt_use_min_rtt_entry = 1;	/* Use the min to calculate the goal else gp_srtt */
287 static uint32_t rack_probertt_use_min_rtt_exit = 0;
288 static uint32_t rack_probe_rtt_sets_cwnd = 0;
289 static uint32_t rack_probe_rtt_safety_val = 2000000;	/* No more than 2 sec in probe-rtt */
290 static uint32_t rack_time_between_probertt = 9600000;	/* 9.6 sec in usecs */
291 static uint32_t rack_probertt_gpsrtt_cnt_mul = 0;	/* How many srtt periods does probe-rtt last top fraction */
292 static uint32_t rack_probertt_gpsrtt_cnt_div = 0;	/* How many srtt periods does probe-rtt last bottom fraction */
293 static uint32_t rack_min_probertt_hold = 40000;		/* Equal to delayed ack time */
294 static uint32_t rack_probertt_filter_life = 10000000;
295 static uint32_t rack_probertt_lower_within = 10;
296 static uint32_t rack_min_rtt_movement = 250000;	/* Must move at least 250ms (in microseconds)  to count as a lowering */
297 static int32_t rack_pace_one_seg = 0;		/* Shall we pace for less than 1.4Meg 1MSS at a time */
298 static int32_t rack_probertt_clear_is = 1;
299 static int32_t rack_max_drain_hbp = 1;		/* Extra drain times gpsrtt for highly buffered paths */
300 static int32_t rack_hbp_thresh = 3;		/* what is the divisor max_rtt/min_rtt to decided a hbp */
301 
302 /* Part of pacing */
303 static int32_t rack_max_per_above = 30;		/* When we go to increment stop if above 100+this% */
304 
305 /* Timely information */
306 /* Combine these two gives the range of 'no change' to bw */
307 /* ie the up/down provide the upper and lower bound */
308 static int32_t rack_gp_per_bw_mul_up = 2;	/* 2% */
309 static int32_t rack_gp_per_bw_mul_down = 4;	/* 4% */
310 static int32_t rack_gp_rtt_maxmul = 3;		/* 3 x maxmin */
311 static int32_t rack_gp_rtt_minmul = 1;		/* minrtt + (minrtt/mindiv) is lower rtt */
312 static int32_t rack_gp_rtt_mindiv = 4;		/* minrtt + (minrtt * minmul/mindiv) is lower rtt */
313 static int32_t rack_gp_decrease_per = 20;	/* 20% decrease in multiplier */
314 static int32_t rack_gp_increase_per = 2;	/* 2% increase in multiplier */
315 static int32_t rack_per_lower_bound = 50;	/* Don't allow to drop below this multiplier */
316 static int32_t rack_per_upper_bound_ss = 0;	/* Don't allow SS to grow above this */
317 static int32_t rack_per_upper_bound_ca = 0;	/* Don't allow CA to grow above this */
318 static int32_t rack_do_dyn_mul = 0;		/* Are the rack gp multipliers dynamic */
319 static int32_t rack_gp_no_rec_chg = 1;		/* Prohibit recovery from reducing it's multiplier */
320 static int32_t rack_timely_dec_clear = 6;	/* Do we clear decrement count at a value (6)? */
321 static int32_t rack_timely_max_push_rise = 3;	/* One round of pushing */
322 static int32_t rack_timely_max_push_drop = 3;	/* Three round of pushing */
323 static int32_t rack_timely_min_segs = 4;	/* 4 segment minimum */
324 static int32_t rack_use_max_for_nobackoff = 0;
325 static int32_t rack_timely_int_timely_only = 0;	/* do interim timely's only use the timely algo (no b/w changes)? */
326 static int32_t rack_timely_no_stopping = 0;
327 static int32_t rack_down_raise_thresh = 100;
328 static int32_t rack_req_segs = 1;
329 static uint64_t rack_bw_rate_cap = 0;
330 static uint32_t rack_trace_point_config = 0;
331 static uint32_t rack_trace_point_bb_mode = 4;
332 static int32_t rack_trace_point_count = 0;
333 
334 
335 /* Weird delayed ack mode */
336 static int32_t rack_use_imac_dack = 0;
337 /* Rack specific counters */
338 counter_u64_t rack_saw_enobuf;
339 counter_u64_t rack_saw_enobuf_hw;
340 counter_u64_t rack_saw_enetunreach;
341 counter_u64_t rack_persists_sends;
342 counter_u64_t rack_persists_acks;
343 counter_u64_t rack_persists_loss;
344 counter_u64_t rack_persists_lost_ends;
345 #ifdef INVARIANTS
346 counter_u64_t rack_adjust_map_bw;
347 #endif
348 /* Tail loss probe counters */
349 counter_u64_t rack_tlp_tot;
350 counter_u64_t rack_tlp_newdata;
351 counter_u64_t rack_tlp_retran;
352 counter_u64_t rack_tlp_retran_bytes;
353 counter_u64_t rack_to_tot;
354 counter_u64_t rack_hot_alloc;
355 counter_u64_t rack_to_alloc;
356 counter_u64_t rack_to_alloc_hard;
357 counter_u64_t rack_to_alloc_emerg;
358 counter_u64_t rack_to_alloc_limited;
359 counter_u64_t rack_alloc_limited_conns;
360 counter_u64_t rack_split_limited;
361 
362 counter_u64_t rack_multi_single_eq;
363 counter_u64_t rack_proc_non_comp_ack;
364 
365 counter_u64_t rack_fto_send;
366 counter_u64_t rack_fto_rsm_send;
367 counter_u64_t rack_nfto_resend;
368 counter_u64_t rack_non_fto_send;
369 counter_u64_t rack_extended_rfo;
370 
371 counter_u64_t rack_sack_proc_all;
372 counter_u64_t rack_sack_proc_short;
373 counter_u64_t rack_sack_proc_restart;
374 counter_u64_t rack_sack_attacks_detected;
375 counter_u64_t rack_sack_attacks_reversed;
376 counter_u64_t rack_sack_used_next_merge;
377 counter_u64_t rack_sack_splits;
378 counter_u64_t rack_sack_used_prev_merge;
379 counter_u64_t rack_sack_skipped_acked;
380 counter_u64_t rack_ack_total;
381 counter_u64_t rack_express_sack;
382 counter_u64_t rack_sack_total;
383 counter_u64_t rack_move_none;
384 counter_u64_t rack_move_some;
385 
386 counter_u64_t rack_input_idle_reduces;
387 counter_u64_t rack_collapsed_win;
388 counter_u64_t rack_collapsed_win_seen;
389 counter_u64_t rack_collapsed_win_rxt;
390 counter_u64_t rack_collapsed_win_rxt_bytes;
391 counter_u64_t rack_try_scwnd;
392 counter_u64_t rack_hw_pace_init_fail;
393 counter_u64_t rack_hw_pace_lost;
394 
395 counter_u64_t rack_out_size[TCP_MSS_ACCT_SIZE];
396 counter_u64_t rack_opts_arry[RACK_OPTS_SIZE];
397 
398 
399 #define	RACK_REXMTVAL(tp) max(rack_rto_min, ((tp)->t_srtt + ((tp)->t_rttvar << 2)))
400 
401 #define	RACK_TCPT_RANGESET(tv, value, tvmin, tvmax, slop) do {	\
402 	(tv) = (value) + slop;	 \
403 	if ((u_long)(tv) < (u_long)(tvmin)) \
404 		(tv) = (tvmin); \
405 	if ((u_long)(tv) > (u_long)(tvmax)) \
406 		(tv) = (tvmax); \
407 } while (0)
408 
409 static void
410 rack_log_progress_event(struct tcp_rack *rack, struct tcpcb *tp, uint32_t tick,  int event, int line);
411 
412 static int
413 rack_process_ack(struct mbuf *m, struct tcphdr *th,
414     struct socket *so, struct tcpcb *tp, struct tcpopt *to,
415     uint32_t tiwin, int32_t tlen, int32_t * ofia, int32_t thflags, int32_t * ret_val);
416 static int
417 rack_process_data(struct mbuf *m, struct tcphdr *th,
418     struct socket *so, struct tcpcb *tp, int32_t drop_hdrlen, int32_t tlen,
419     uint32_t tiwin, int32_t thflags, int32_t nxt_pkt);
420 static void
421 rack_ack_received(struct tcpcb *tp, struct tcp_rack *rack,
422    uint32_t th_ack, uint16_t nsegs, uint16_t type, int32_t recovery);
423 static struct rack_sendmap *rack_alloc(struct tcp_rack *rack);
424 static struct rack_sendmap *rack_alloc_limit(struct tcp_rack *rack,
425     uint8_t limit_type);
426 static struct rack_sendmap *
427 rack_check_recovery_mode(struct tcpcb *tp,
428     uint32_t tsused);
429 static void
430 rack_cong_signal(struct tcpcb *tp,
431 		 uint32_t type, uint32_t ack, int );
432 static void rack_counter_destroy(void);
433 static int
434 rack_ctloutput(struct inpcb *inp, struct sockopt *sopt);
435 static int32_t rack_ctor(void *mem, int32_t size, void *arg, int32_t how);
436 static void
437 rack_set_pace_segments(struct tcpcb *tp, struct tcp_rack *rack, uint32_t line, uint64_t *fill_override);
438 static void
439 rack_do_segment(struct mbuf *m, struct tcphdr *th,
440     struct socket *so, struct tcpcb *tp, int32_t drop_hdrlen, int32_t tlen,
441     uint8_t iptos);
442 static void rack_dtor(void *mem, int32_t size, void *arg);
443 static void
444 rack_log_alt_to_to_cancel(struct tcp_rack *rack,
445     uint32_t flex1, uint32_t flex2,
446     uint32_t flex3, uint32_t flex4,
447     uint32_t flex5, uint32_t flex6,
448     uint16_t flex7, uint8_t mod);
449 
450 static void
451 rack_log_pacing_delay_calc(struct tcp_rack *rack, uint32_t len, uint32_t slot,
452    uint64_t bw_est, uint64_t bw, uint64_t len_time, int method, int line,
453    struct rack_sendmap *rsm, uint8_t quality);
454 static struct rack_sendmap *
455 rack_find_high_nonack(struct tcp_rack *rack,
456     struct rack_sendmap *rsm);
457 static struct rack_sendmap *rack_find_lowest_rsm(struct tcp_rack *rack);
458 static void rack_free(struct tcp_rack *rack, struct rack_sendmap *rsm);
459 static void rack_fini(struct tcpcb *tp, int32_t tcb_is_purged);
460 static int rack_get_sockopt(struct inpcb *inp, struct sockopt *sopt);
461 static void
462 rack_do_goodput_measurement(struct tcpcb *tp, struct tcp_rack *rack,
463 			    tcp_seq th_ack, int line, uint8_t quality);
464 static uint32_t
465 rack_get_pacing_len(struct tcp_rack *rack, uint64_t bw, uint32_t mss);
466 static int32_t rack_handoff_ok(struct tcpcb *tp);
467 static int32_t rack_init(struct tcpcb *tp);
468 static void rack_init_sysctls(void);
469 static void
470 rack_log_ack(struct tcpcb *tp, struct tcpopt *to,
471     struct tcphdr *th, int entered_rec, int dup_ack_struck);
472 static void
473 rack_log_output(struct tcpcb *tp, struct tcpopt *to, int32_t len,
474     uint32_t seq_out, uint16_t th_flags, int32_t err, uint64_t ts,
475     struct rack_sendmap *hintrsm, uint16_t add_flags, struct mbuf *s_mb, uint32_t s_moff, int hw_tls);
476 
477 static void
478 rack_log_sack_passed(struct tcpcb *tp, struct tcp_rack *rack,
479     struct rack_sendmap *rsm);
480 static void rack_log_to_event(struct tcp_rack *rack, int32_t to_num, struct rack_sendmap *rsm);
481 static int32_t rack_output(struct tcpcb *tp);
482 
483 static uint32_t
484 rack_proc_sack_blk(struct tcpcb *tp, struct tcp_rack *rack,
485     struct sackblk *sack, struct tcpopt *to, struct rack_sendmap **prsm,
486     uint32_t cts, int *moved_two);
487 static void rack_post_recovery(struct tcpcb *tp, uint32_t th_seq);
488 static void rack_remxt_tmr(struct tcpcb *tp);
489 static int rack_set_sockopt(struct inpcb *inp, struct sockopt *sopt);
490 static void rack_set_state(struct tcpcb *tp, struct tcp_rack *rack);
491 static int32_t rack_stopall(struct tcpcb *tp);
492 static void
493 rack_timer_activate(struct tcpcb *tp, uint32_t timer_type,
494     uint32_t delta);
495 static int32_t rack_timer_active(struct tcpcb *tp, uint32_t timer_type);
496 static void rack_timer_cancel(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cts, int line);
497 static void rack_timer_stop(struct tcpcb *tp, uint32_t timer_type);
498 static uint32_t
499 rack_update_entry(struct tcpcb *tp, struct tcp_rack *rack,
500     struct rack_sendmap *rsm, uint64_t ts, int32_t * lenp, uint16_t add_flag);
501 static void
502 rack_update_rsm(struct tcpcb *tp, struct tcp_rack *rack,
503     struct rack_sendmap *rsm, uint64_t ts, uint16_t add_flag);
504 static int
505 rack_update_rtt(struct tcpcb *tp, struct tcp_rack *rack,
506     struct rack_sendmap *rsm, struct tcpopt *to, uint32_t cts, int32_t ack_type, tcp_seq th_ack);
507 static int32_t tcp_addrack(module_t mod, int32_t type, void *data);
508 static int
509 rack_do_close_wait(struct mbuf *m, struct tcphdr *th,
510     struct socket *so, struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen,
511     int32_t tlen, uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos);
512 static int
513 rack_do_closing(struct mbuf *m, struct tcphdr *th,
514     struct socket *so, struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen,
515     int32_t tlen, uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos);
516 static int
517 rack_do_established(struct mbuf *m, struct tcphdr *th,
518     struct socket *so, struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen,
519     int32_t tlen, uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos);
520 static int
521 rack_do_fastnewdata(struct mbuf *m, struct tcphdr *th,
522     struct socket *so, struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen,
523     int32_t tlen, uint32_t tiwin, int32_t nxt_pkt, uint8_t iptos);
524 static int
525 rack_do_fin_wait_1(struct mbuf *m, struct tcphdr *th,
526     struct socket *so, struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen,
527     int32_t tlen, uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos);
528 static int
529 rack_do_fin_wait_2(struct mbuf *m, struct tcphdr *th,
530     struct socket *so, struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen,
531     int32_t tlen, uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos);
532 static int
533 rack_do_lastack(struct mbuf *m, struct tcphdr *th,
534     struct socket *so, struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen,
535     int32_t tlen, uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos);
536 static int
537 rack_do_syn_recv(struct mbuf *m, struct tcphdr *th,
538     struct socket *so, struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen,
539     int32_t tlen, uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos);
540 static int
541 rack_do_syn_sent(struct mbuf *m, struct tcphdr *th,
542     struct socket *so, struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen,
543     int32_t tlen, uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos);
544 struct rack_sendmap *
545 tcp_rack_output(struct tcpcb *tp, struct tcp_rack *rack,
546     uint32_t tsused);
547 static void tcp_rack_xmit_timer(struct tcp_rack *rack, int32_t rtt,
548     uint32_t len, uint32_t us_tim, int confidence, struct rack_sendmap *rsm, uint16_t rtrcnt);
549 static void
550      tcp_rack_partialack(struct tcpcb *tp);
551 static int
552 rack_set_profile(struct tcp_rack *rack, int prof);
553 static void
554 rack_apply_deferred_options(struct tcp_rack *rack);
555 
556 int32_t rack_clear_counter=0;
557 
558 static inline void
559 rack_trace_point(struct tcp_rack *rack, int num)
560 {
561 	if (((rack_trace_point_config == num)  ||
562 	     (rack_trace_point_config = 0xffffffff)) &&
563 	    (rack_trace_point_bb_mode != 0) &&
564 	    (rack_trace_point_count > 0) &&
565 	    (rack->rc_tp->t_logstate == 0)) {
566 		int res;
567 		res = atomic_fetchadd_int(&rack_trace_point_count, -1);
568 		if (res > 0) {
569 			rack->rc_tp->t_logstate = rack_trace_point_bb_mode;
570 		} else {
571 			/* Loss a race assure its zero now */
572 			rack_trace_point_count = 0;
573 		}
574 	}
575 }
576 
577 static void
578 rack_set_cc_pacing(struct tcp_rack *rack)
579 {
580 	struct sockopt sopt;
581 	struct cc_newreno_opts opt;
582 	struct newreno old, *ptr;
583 	struct tcpcb *tp;
584 	int error;
585 
586 	if (rack->rc_pacing_cc_set)
587 		return;
588 
589 	tp = rack->rc_tp;
590 	if (tp->cc_algo == NULL) {
591 		/* Tcb is leaving */
592 		return;
593 	}
594 	rack->rc_pacing_cc_set = 1;
595 	if (strcmp(tp->cc_algo->name, CCALGONAME_NEWRENO) != 0) {
596 		/* Not new-reno we can't play games with beta! */
597 		goto out;
598 	}
599 	ptr = ((struct newreno *)tp->ccv->cc_data);
600 	if (CC_ALGO(tp)->ctl_output == NULL)  {
601 		/* Huh, why does new_reno no longer have a set function? */
602 		goto out;
603 	}
604 	if (ptr == NULL) {
605 		/* Just the default values */
606 		old.beta = V_newreno_beta_ecn;
607 		old.beta_ecn = V_newreno_beta_ecn;
608 		old.newreno_flags = 0;
609 	} else {
610 		old.beta = ptr->beta;
611 		old.beta_ecn = ptr->beta_ecn;
612 		old.newreno_flags = ptr->newreno_flags;
613 	}
614 	sopt.sopt_valsize = sizeof(struct cc_newreno_opts);
615 	sopt.sopt_dir = SOPT_SET;
616 	opt.name = CC_NEWRENO_BETA;
617 	opt.val = rack->r_ctl.rc_saved_beta.beta;
618 	error = CC_ALGO(tp)->ctl_output(tp->ccv, &sopt, &opt);
619 	if (error)  {
620 		goto out;
621 	}
622 	/*
623 	 * Hack alert we need to set in our newreno_flags
624 	 * so that Abe behavior is also applied.
625 	 */
626 	((struct newreno *)tp->ccv->cc_data)->newreno_flags |= CC_NEWRENO_BETA_ECN_ENABLED;
627 	opt.name = CC_NEWRENO_BETA_ECN;
628 	opt.val = rack->r_ctl.rc_saved_beta.beta_ecn;
629 	error = CC_ALGO(tp)->ctl_output(tp->ccv, &sopt, &opt);
630 	if (error) {
631 		goto out;
632 	}
633 	/* Save off the original values for restoral */
634 	memcpy(&rack->r_ctl.rc_saved_beta, &old, sizeof(struct newreno));
635 out:
636 	if (rack_verbose_logging && (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF)) {
637 		union tcp_log_stackspecific log;
638 		struct timeval tv;
639 
640 		ptr = ((struct newreno *)tp->ccv->cc_data);
641 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
642 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
643 		if (ptr) {
644 			log.u_bbr.flex1 = ptr->beta;
645 			log.u_bbr.flex2 = ptr->beta_ecn;
646 			log.u_bbr.flex3 = ptr->newreno_flags;
647 		}
648 		log.u_bbr.flex4 = rack->r_ctl.rc_saved_beta.beta;
649 		log.u_bbr.flex5 = rack->r_ctl.rc_saved_beta.beta_ecn;
650 		log.u_bbr.flex6 = rack->r_ctl.rc_saved_beta.newreno_flags;
651 		log.u_bbr.flex7 = rack->gp_ready;
652 		log.u_bbr.flex7 <<= 1;
653 		log.u_bbr.flex7 |= rack->use_fixed_rate;
654 		log.u_bbr.flex7 <<= 1;
655 		log.u_bbr.flex7 |= rack->rc_pacing_cc_set;
656 		log.u_bbr.pkts_out = rack->r_ctl.rc_prr_sndcnt;
657 		log.u_bbr.flex8 = 3;
658 		tcp_log_event_(tp, NULL, NULL, NULL, BBR_LOG_CWND, error,
659 			       0, &log, false, NULL, NULL, 0, &tv);
660 	}
661 }
662 
663 static void
664 rack_undo_cc_pacing(struct tcp_rack *rack)
665 {
666 	struct newreno old, *ptr;
667 	struct tcpcb *tp;
668 
669 	if (rack->rc_pacing_cc_set == 0)
670 		return;
671 	tp = rack->rc_tp;
672 	rack->rc_pacing_cc_set = 0;
673 	if (tp->cc_algo == NULL)
674 		/* Tcb is leaving */
675 		return;
676 	if (strcmp(tp->cc_algo->name, CCALGONAME_NEWRENO) != 0) {
677 		/* Not new-reno nothing to do! */
678 		return;
679 	}
680 	ptr = ((struct newreno *)tp->ccv->cc_data);
681 	if (ptr == NULL) {
682 		/*
683 		 * This happens at rack_fini() if the
684 		 * cc module gets freed on us. In that
685 		 * case we loose our "new" settings but
686 		 * thats ok, since the tcb is going away anyway.
687 		 */
688 		return;
689 	}
690 	/* Grab out our set values */
691 	memcpy(&old, ptr, sizeof(struct newreno));
692 	/* Copy back in the original values */
693 	memcpy(ptr, &rack->r_ctl.rc_saved_beta, sizeof(struct newreno));
694 	/* Now save back the values we had set in (for when pacing is restored) */
695 	memcpy(&rack->r_ctl.rc_saved_beta, &old, sizeof(struct newreno));
696 	if (rack_verbose_logging && (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF)) {
697 		union tcp_log_stackspecific log;
698 		struct timeval tv;
699 
700 		ptr = ((struct newreno *)tp->ccv->cc_data);
701 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
702 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
703 		log.u_bbr.flex1 = ptr->beta;
704 		log.u_bbr.flex2 = ptr->beta_ecn;
705 		log.u_bbr.flex3 = ptr->newreno_flags;
706 		log.u_bbr.flex4 = rack->r_ctl.rc_saved_beta.beta;
707 		log.u_bbr.flex5 = rack->r_ctl.rc_saved_beta.beta_ecn;
708 		log.u_bbr.flex6 = rack->r_ctl.rc_saved_beta.newreno_flags;
709 		log.u_bbr.flex7 = rack->gp_ready;
710 		log.u_bbr.flex7 <<= 1;
711 		log.u_bbr.flex7 |= rack->use_fixed_rate;
712 		log.u_bbr.flex7 <<= 1;
713 		log.u_bbr.flex7 |= rack->rc_pacing_cc_set;
714 		log.u_bbr.pkts_out = rack->r_ctl.rc_prr_sndcnt;
715 		log.u_bbr.flex8 = 4;
716 		tcp_log_event_(tp, NULL, NULL, NULL, BBR_LOG_CWND, 0,
717 			       0, &log, false, NULL, NULL, 0, &tv);
718 	}
719 }
720 
721 #ifdef NETFLIX_PEAKRATE
722 static inline void
723 rack_update_peakrate_thr(struct tcpcb *tp)
724 {
725 	/* Keep in mind that t_maxpeakrate is in B/s. */
726 	uint64_t peak;
727 	peak = uqmax((tp->t_maxseg * 2),
728 		     (((uint64_t)tp->t_maxpeakrate * (uint64_t)(tp->t_srtt)) / (uint64_t)HPTS_USEC_IN_SEC));
729 	tp->t_peakrate_thr = (uint32_t)uqmin(peak, UINT32_MAX);
730 }
731 #endif
732 
733 static int
734 sysctl_rack_clear(SYSCTL_HANDLER_ARGS)
735 {
736 	uint32_t stat;
737 	int32_t error;
738 
739 	error = SYSCTL_OUT(req, &rack_clear_counter, sizeof(uint32_t));
740 	if (error || req->newptr == NULL)
741 		return error;
742 
743 	error = SYSCTL_IN(req, &stat, sizeof(uint32_t));
744 	if (error)
745 		return (error);
746 	if (stat == 1) {
747 #ifdef INVARIANTS
748 		printf("Clearing RACK counters\n");
749 #endif
750 		counter_u64_zero(rack_tlp_tot);
751 		counter_u64_zero(rack_tlp_newdata);
752 		counter_u64_zero(rack_tlp_retran);
753 		counter_u64_zero(rack_tlp_retran_bytes);
754 		counter_u64_zero(rack_to_tot);
755 		counter_u64_zero(rack_saw_enobuf);
756 		counter_u64_zero(rack_saw_enobuf_hw);
757 		counter_u64_zero(rack_saw_enetunreach);
758 		counter_u64_zero(rack_persists_sends);
759 		counter_u64_zero(rack_persists_acks);
760 		counter_u64_zero(rack_persists_loss);
761 		counter_u64_zero(rack_persists_lost_ends);
762 #ifdef INVARIANTS
763 		counter_u64_zero(rack_adjust_map_bw);
764 #endif
765 		counter_u64_zero(rack_to_alloc_hard);
766 		counter_u64_zero(rack_to_alloc_emerg);
767 		counter_u64_zero(rack_sack_proc_all);
768 		counter_u64_zero(rack_fto_send);
769 		counter_u64_zero(rack_fto_rsm_send);
770 		counter_u64_zero(rack_extended_rfo);
771 		counter_u64_zero(rack_hw_pace_init_fail);
772 		counter_u64_zero(rack_hw_pace_lost);
773 		counter_u64_zero(rack_non_fto_send);
774 		counter_u64_zero(rack_nfto_resend);
775 		counter_u64_zero(rack_sack_proc_short);
776 		counter_u64_zero(rack_sack_proc_restart);
777 		counter_u64_zero(rack_to_alloc);
778 		counter_u64_zero(rack_to_alloc_limited);
779 		counter_u64_zero(rack_alloc_limited_conns);
780 		counter_u64_zero(rack_split_limited);
781 		counter_u64_zero(rack_multi_single_eq);
782 		counter_u64_zero(rack_proc_non_comp_ack);
783 		counter_u64_zero(rack_sack_attacks_detected);
784 		counter_u64_zero(rack_sack_attacks_reversed);
785 		counter_u64_zero(rack_sack_used_next_merge);
786 		counter_u64_zero(rack_sack_used_prev_merge);
787 		counter_u64_zero(rack_sack_splits);
788 		counter_u64_zero(rack_sack_skipped_acked);
789 		counter_u64_zero(rack_ack_total);
790 		counter_u64_zero(rack_express_sack);
791 		counter_u64_zero(rack_sack_total);
792 		counter_u64_zero(rack_move_none);
793 		counter_u64_zero(rack_move_some);
794 		counter_u64_zero(rack_try_scwnd);
795 		counter_u64_zero(rack_collapsed_win);
796 		counter_u64_zero(rack_collapsed_win_rxt);
797 		counter_u64_zero(rack_collapsed_win_seen);
798 		counter_u64_zero(rack_collapsed_win_rxt_bytes);
799 	}
800 	rack_clear_counter = 0;
801 	return (0);
802 }
803 
804 static void
805 rack_init_sysctls(void)
806 {
807 	struct sysctl_oid *rack_counters;
808 	struct sysctl_oid *rack_attack;
809 	struct sysctl_oid *rack_pacing;
810 	struct sysctl_oid *rack_timely;
811 	struct sysctl_oid *rack_timers;
812 	struct sysctl_oid *rack_tlp;
813 	struct sysctl_oid *rack_misc;
814 	struct sysctl_oid *rack_features;
815 	struct sysctl_oid *rack_measure;
816 	struct sysctl_oid *rack_probertt;
817 	struct sysctl_oid *rack_hw_pacing;
818 	struct sysctl_oid *rack_tracepoint;
819 
820 	rack_attack = SYSCTL_ADD_NODE(&rack_sysctl_ctx,
821 	    SYSCTL_CHILDREN(rack_sysctl_root),
822 	    OID_AUTO,
823 	    "sack_attack",
824 	    CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
825 	    "Rack Sack Attack Counters and Controls");
826 	rack_counters = SYSCTL_ADD_NODE(&rack_sysctl_ctx,
827 	    SYSCTL_CHILDREN(rack_sysctl_root),
828 	    OID_AUTO,
829 	    "stats",
830 	    CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
831 	    "Rack Counters");
832 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
833 	    SYSCTL_CHILDREN(rack_sysctl_root),
834 	    OID_AUTO, "rate_sample_method", CTLFLAG_RW,
835 	    &rack_rate_sample_method , USE_RTT_LOW,
836 	    "What method should we use for rate sampling 0=high, 1=low ");
837 	/* Probe rtt related controls */
838 	rack_probertt = SYSCTL_ADD_NODE(&rack_sysctl_ctx,
839 	    SYSCTL_CHILDREN(rack_sysctl_root),
840 	    OID_AUTO,
841 	    "probertt",
842 	    CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
843 	    "ProbeRTT related Controls");
844 	SYSCTL_ADD_U16(&rack_sysctl_ctx,
845 	    SYSCTL_CHILDREN(rack_probertt),
846 	    OID_AUTO, "exit_per_hpb", CTLFLAG_RW,
847 	    &rack_atexit_prtt_hbp, 130,
848 	    "What percentage above goodput do we clamp CA/SS to at exit on high-BDP path 110%");
849 	SYSCTL_ADD_U16(&rack_sysctl_ctx,
850 	    SYSCTL_CHILDREN(rack_probertt),
851 	    OID_AUTO, "exit_per_nonhpb", CTLFLAG_RW,
852 	    &rack_atexit_prtt, 130,
853 	    "What percentage above goodput do we clamp CA/SS to at exit on a non high-BDP path 100%");
854 	SYSCTL_ADD_U16(&rack_sysctl_ctx,
855 	    SYSCTL_CHILDREN(rack_probertt),
856 	    OID_AUTO, "gp_per_mul", CTLFLAG_RW,
857 	    &rack_per_of_gp_probertt, 60,
858 	    "What percentage of goodput do we pace at in probertt");
859 	SYSCTL_ADD_U16(&rack_sysctl_ctx,
860 	    SYSCTL_CHILDREN(rack_probertt),
861 	    OID_AUTO, "gp_per_reduce", CTLFLAG_RW,
862 	    &rack_per_of_gp_probertt_reduce, 10,
863 	    "What percentage of goodput do we reduce every gp_srtt");
864 	SYSCTL_ADD_U16(&rack_sysctl_ctx,
865 	    SYSCTL_CHILDREN(rack_probertt),
866 	    OID_AUTO, "gp_per_low", CTLFLAG_RW,
867 	    &rack_per_of_gp_lowthresh, 40,
868 	    "What percentage of goodput do we allow the multiplier to fall to");
869 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
870 	    SYSCTL_CHILDREN(rack_probertt),
871 	    OID_AUTO, "time_between", CTLFLAG_RW,
872 	    & rack_time_between_probertt, 96000000,
873 	    "How many useconds between the lowest rtt falling must past before we enter probertt");
874 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
875 	    SYSCTL_CHILDREN(rack_probertt),
876 	    OID_AUTO, "safety", CTLFLAG_RW,
877 	    &rack_probe_rtt_safety_val, 2000000,
878 	    "If not zero, provides a maximum usecond that you can stay in probertt (2sec = 2000000)");
879 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
880 	    SYSCTL_CHILDREN(rack_probertt),
881 	    OID_AUTO, "sets_cwnd", CTLFLAG_RW,
882 	    &rack_probe_rtt_sets_cwnd, 0,
883 	    "Do we set the cwnd too (if always_lower is on)");
884 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
885 	    SYSCTL_CHILDREN(rack_probertt),
886 	    OID_AUTO, "maxdrainsrtts", CTLFLAG_RW,
887 	    &rack_max_drain_wait, 2,
888 	    "Maximum number of gp_srtt's to hold in drain waiting for flight to reach goal");
889 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
890 	    SYSCTL_CHILDREN(rack_probertt),
891 	    OID_AUTO, "mustdrainsrtts", CTLFLAG_RW,
892 	    &rack_must_drain, 1,
893 	    "We must drain this many gp_srtt's waiting for flight to reach goal");
894 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
895 	    SYSCTL_CHILDREN(rack_probertt),
896 	    OID_AUTO, "goal_use_min_entry", CTLFLAG_RW,
897 	    &rack_probertt_use_min_rtt_entry, 1,
898 	    "Should we use the min-rtt to calculate the goal rtt (else gp_srtt) at entry");
899 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
900 	    SYSCTL_CHILDREN(rack_probertt),
901 	    OID_AUTO, "goal_use_min_exit", CTLFLAG_RW,
902 	    &rack_probertt_use_min_rtt_exit, 0,
903 	    "How to set cwnd at exit, 0 - dynamic, 1 - use min-rtt, 2 - use curgprtt, 3 - entry gp-rtt");
904 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
905 	    SYSCTL_CHILDREN(rack_probertt),
906 	    OID_AUTO, "length_div", CTLFLAG_RW,
907 	    &rack_probertt_gpsrtt_cnt_div, 0,
908 	    "How many recent goodput srtt periods plus hold tim does probertt last (bottom of fraction)");
909 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
910 	    SYSCTL_CHILDREN(rack_probertt),
911 	    OID_AUTO, "length_mul", CTLFLAG_RW,
912 	    &rack_probertt_gpsrtt_cnt_mul, 0,
913 	    "How many recent goodput srtt periods plus hold tim does probertt last (top of fraction)");
914 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
915 	    SYSCTL_CHILDREN(rack_probertt),
916 	    OID_AUTO, "holdtim_at_target", CTLFLAG_RW,
917 	    &rack_min_probertt_hold, 200000,
918 	    "What is the minimum time we hold probertt at target");
919 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
920 	    SYSCTL_CHILDREN(rack_probertt),
921 	    OID_AUTO, "filter_life", CTLFLAG_RW,
922 	    &rack_probertt_filter_life, 10000000,
923 	    "What is the time for the filters life in useconds");
924 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
925 	    SYSCTL_CHILDREN(rack_probertt),
926 	    OID_AUTO, "lower_within", CTLFLAG_RW,
927 	    &rack_probertt_lower_within, 10,
928 	    "If the rtt goes lower within this percentage of the time, go into probe-rtt");
929 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
930 	    SYSCTL_CHILDREN(rack_probertt),
931 	    OID_AUTO, "must_move", CTLFLAG_RW,
932 	    &rack_min_rtt_movement, 250,
933 	    "How much is the minimum movement in rtt to count as a drop for probertt purposes");
934 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
935 	    SYSCTL_CHILDREN(rack_probertt),
936 	    OID_AUTO, "clear_is_cnts", CTLFLAG_RW,
937 	    &rack_probertt_clear_is, 1,
938 	    "Do we clear I/S counts on exiting probe-rtt");
939 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
940 	    SYSCTL_CHILDREN(rack_probertt),
941 	    OID_AUTO, "hbp_extra_drain", CTLFLAG_RW,
942 	    &rack_max_drain_hbp, 1,
943 	    "How many extra drain gpsrtt's do we get in highly buffered paths");
944 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
945 	    SYSCTL_CHILDREN(rack_probertt),
946 	    OID_AUTO, "hbp_threshold", CTLFLAG_RW,
947 	    &rack_hbp_thresh, 3,
948 	    "We are highly buffered if min_rtt_seen / max_rtt_seen > this-threshold");
949 
950 	rack_tracepoint = SYSCTL_ADD_NODE(&rack_sysctl_ctx,
951 	    SYSCTL_CHILDREN(rack_sysctl_root),
952 	    OID_AUTO,
953 	    "tp",
954 	    CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
955 	    "Rack tracepoint facility");
956 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
957 	    SYSCTL_CHILDREN(rack_tracepoint),
958 	    OID_AUTO, "number", CTLFLAG_RW,
959 	    &rack_trace_point_config, 0,
960 	    "What is the trace point number to activate (0=none, 0xffffffff = all)?");
961 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
962 	    SYSCTL_CHILDREN(rack_tracepoint),
963 	    OID_AUTO, "bbmode", CTLFLAG_RW,
964 	    &rack_trace_point_bb_mode, 4,
965 	    "What is BB logging mode that is activated?");
966 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
967 	    SYSCTL_CHILDREN(rack_tracepoint),
968 	    OID_AUTO, "count", CTLFLAG_RW,
969 	    &rack_trace_point_count, 0,
970 	    "How many connections will have BB logging turned on that hit the tracepoint?");
971 	/* Pacing related sysctls */
972 	rack_pacing = SYSCTL_ADD_NODE(&rack_sysctl_ctx,
973 	    SYSCTL_CHILDREN(rack_sysctl_root),
974 	    OID_AUTO,
975 	    "pacing",
976 	    CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
977 	    "Pacing related Controls");
978 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
979 	    SYSCTL_CHILDREN(rack_pacing),
980 	    OID_AUTO, "max_pace_over", CTLFLAG_RW,
981 	    &rack_max_per_above, 30,
982 	    "What is the maximum allowable percentage that we can pace above (so 30 = 130% of our goal)");
983 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
984 	    SYSCTL_CHILDREN(rack_pacing),
985 	    OID_AUTO, "pace_to_one", CTLFLAG_RW,
986 	    &rack_pace_one_seg, 0,
987 	    "Do we allow low b/w pacing of 1MSS instead of two");
988 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
989 	    SYSCTL_CHILDREN(rack_pacing),
990 	    OID_AUTO, "limit_wsrtt", CTLFLAG_RW,
991 	    &rack_limit_time_with_srtt, 0,
992 	    "Do we limit pacing time based on srtt");
993 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
994 	    SYSCTL_CHILDREN(rack_pacing),
995 	    OID_AUTO, "init_win", CTLFLAG_RW,
996 	    &rack_default_init_window, 0,
997 	    "Do we have a rack initial window 0 = system default");
998 	SYSCTL_ADD_U16(&rack_sysctl_ctx,
999 	    SYSCTL_CHILDREN(rack_pacing),
1000 	    OID_AUTO, "gp_per_ss", CTLFLAG_RW,
1001 	    &rack_per_of_gp_ss, 250,
1002 	    "If non zero, what percentage of goodput to pace at in slow start");
1003 	SYSCTL_ADD_U16(&rack_sysctl_ctx,
1004 	    SYSCTL_CHILDREN(rack_pacing),
1005 	    OID_AUTO, "gp_per_ca", CTLFLAG_RW,
1006 	    &rack_per_of_gp_ca, 150,
1007 	    "If non zero, what percentage of goodput to pace at in congestion avoidance");
1008 	SYSCTL_ADD_U16(&rack_sysctl_ctx,
1009 	    SYSCTL_CHILDREN(rack_pacing),
1010 	    OID_AUTO, "gp_per_rec", CTLFLAG_RW,
1011 	    &rack_per_of_gp_rec, 200,
1012 	    "If non zero, what percentage of goodput to pace at in recovery");
1013 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1014 	    SYSCTL_CHILDREN(rack_pacing),
1015 	    OID_AUTO, "pace_max_seg", CTLFLAG_RW,
1016 	    &rack_hptsi_segments, 40,
1017 	    "What size is the max for TSO segments in pacing and burst mitigation");
1018 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1019 	    SYSCTL_CHILDREN(rack_pacing),
1020 	    OID_AUTO, "burst_reduces", CTLFLAG_RW,
1021 	    &rack_slot_reduction, 4,
1022 	    "When doing only burst mitigation what is the reduce divisor");
1023 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1024 	    SYSCTL_CHILDREN(rack_sysctl_root),
1025 	    OID_AUTO, "use_pacing", CTLFLAG_RW,
1026 	    &rack_pace_every_seg, 0,
1027 	    "If set we use pacing, if clear we use only the original burst mitigation");
1028 	SYSCTL_ADD_U64(&rack_sysctl_ctx,
1029 	    SYSCTL_CHILDREN(rack_pacing),
1030 	    OID_AUTO, "rate_cap", CTLFLAG_RW,
1031 	    &rack_bw_rate_cap, 0,
1032 	    "If set we apply this value to the absolute rate cap used by pacing");
1033 	SYSCTL_ADD_U8(&rack_sysctl_ctx,
1034 	    SYSCTL_CHILDREN(rack_sysctl_root),
1035 	    OID_AUTO, "req_measure_cnt", CTLFLAG_RW,
1036 	    &rack_req_measurements, 1,
1037 	    "If doing dynamic pacing, how many measurements must be in before we start pacing?");
1038 	/* Hardware pacing */
1039 	rack_hw_pacing = SYSCTL_ADD_NODE(&rack_sysctl_ctx,
1040 	    SYSCTL_CHILDREN(rack_sysctl_root),
1041 	    OID_AUTO,
1042 	    "hdwr_pacing",
1043 	    CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
1044 	    "Pacing related Controls");
1045 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1046 	    SYSCTL_CHILDREN(rack_hw_pacing),
1047 	    OID_AUTO, "rwnd_factor", CTLFLAG_RW,
1048 	    &rack_hw_rwnd_factor, 2,
1049 	    "How many times does snd_wnd need to be bigger than pace_max_seg so we will hold off and get more acks?");
1050 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1051 	    SYSCTL_CHILDREN(rack_hw_pacing),
1052 	    OID_AUTO, "pace_enobuf_mult", CTLFLAG_RW,
1053 	    &rack_enobuf_hw_boost_mult, 2,
1054 	    "By how many time_betweens should we boost the pacing time if we see a ENOBUFS?");
1055 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1056 	    SYSCTL_CHILDREN(rack_hw_pacing),
1057 	    OID_AUTO, "pace_enobuf_max", CTLFLAG_RW,
1058 	    &rack_enobuf_hw_max, 2,
1059 	    "What is the max boost the pacing time if we see a ENOBUFS?");
1060 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1061 	    SYSCTL_CHILDREN(rack_hw_pacing),
1062 	    OID_AUTO, "pace_enobuf_min", CTLFLAG_RW,
1063 	    &rack_enobuf_hw_min, 2,
1064 	    "What is the min boost the pacing time if we see a ENOBUFS?");
1065 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1066 	    SYSCTL_CHILDREN(rack_hw_pacing),
1067 	    OID_AUTO, "enable", CTLFLAG_RW,
1068 	    &rack_enable_hw_pacing, 0,
1069 	    "Should RACK attempt to use hw pacing?");
1070 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1071 	    SYSCTL_CHILDREN(rack_hw_pacing),
1072 	    OID_AUTO, "rate_cap", CTLFLAG_RW,
1073 	    &rack_hw_rate_caps, 1,
1074 	    "Does the highest hardware pacing rate cap the rate we will send at??");
1075 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1076 	    SYSCTL_CHILDREN(rack_hw_pacing),
1077 	    OID_AUTO, "rate_min", CTLFLAG_RW,
1078 	    &rack_hw_rate_min, 0,
1079 	    "Do we need a minimum estimate of this many bytes per second in order to engage hw pacing?");
1080 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1081 	    SYSCTL_CHILDREN(rack_hw_pacing),
1082 	    OID_AUTO, "rate_to_low", CTLFLAG_RW,
1083 	    &rack_hw_rate_to_low, 0,
1084 	    "If we fall below this rate, dis-engage hw pacing?");
1085 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1086 	    SYSCTL_CHILDREN(rack_hw_pacing),
1087 	    OID_AUTO, "up_only", CTLFLAG_RW,
1088 	    &rack_hw_up_only, 1,
1089 	    "Do we allow hw pacing to lower the rate selected?");
1090 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1091 	    SYSCTL_CHILDREN(rack_hw_pacing),
1092 	    OID_AUTO, "extra_mss_precise", CTLFLAG_RW,
1093 	    &rack_hw_pace_extra_slots, 2,
1094 	    "If the rates between software and hardware match precisely how many extra time_betweens do we get?");
1095 	rack_timely = SYSCTL_ADD_NODE(&rack_sysctl_ctx,
1096 	    SYSCTL_CHILDREN(rack_sysctl_root),
1097 	    OID_AUTO,
1098 	    "timely",
1099 	    CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
1100 	    "Rack Timely RTT Controls");
1101 	/* Timely based GP dynmics */
1102 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1103 	    SYSCTL_CHILDREN(rack_timely),
1104 	    OID_AUTO, "upper", CTLFLAG_RW,
1105 	    &rack_gp_per_bw_mul_up, 2,
1106 	    "Rack timely upper range for equal b/w (in percentage)");
1107 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1108 	    SYSCTL_CHILDREN(rack_timely),
1109 	    OID_AUTO, "lower", CTLFLAG_RW,
1110 	    &rack_gp_per_bw_mul_down, 4,
1111 	    "Rack timely lower range for equal b/w (in percentage)");
1112 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1113 	    SYSCTL_CHILDREN(rack_timely),
1114 	    OID_AUTO, "rtt_max_mul", CTLFLAG_RW,
1115 	    &rack_gp_rtt_maxmul, 3,
1116 	    "Rack timely multiplier of lowest rtt for rtt_max");
1117 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1118 	    SYSCTL_CHILDREN(rack_timely),
1119 	    OID_AUTO, "rtt_min_div", CTLFLAG_RW,
1120 	    &rack_gp_rtt_mindiv, 4,
1121 	    "Rack timely divisor used for rtt + (rtt * mul/divisor) for check for lower rtt");
1122 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1123 	    SYSCTL_CHILDREN(rack_timely),
1124 	    OID_AUTO, "rtt_min_mul", CTLFLAG_RW,
1125 	    &rack_gp_rtt_minmul, 1,
1126 	    "Rack timely multiplier used for rtt + (rtt * mul/divisor) for check for lower rtt");
1127 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1128 	    SYSCTL_CHILDREN(rack_timely),
1129 	    OID_AUTO, "decrease", CTLFLAG_RW,
1130 	    &rack_gp_decrease_per, 20,
1131 	    "Rack timely decrease percentage of our GP multiplication factor");
1132 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1133 	    SYSCTL_CHILDREN(rack_timely),
1134 	    OID_AUTO, "increase", CTLFLAG_RW,
1135 	    &rack_gp_increase_per, 2,
1136 	    "Rack timely increase perentage of our GP multiplication factor");
1137 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1138 	    SYSCTL_CHILDREN(rack_timely),
1139 	    OID_AUTO, "lowerbound", CTLFLAG_RW,
1140 	    &rack_per_lower_bound, 50,
1141 	    "Rack timely lowest percentage we allow GP multiplier to fall to");
1142 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1143 	    SYSCTL_CHILDREN(rack_timely),
1144 	    OID_AUTO, "upperboundss", CTLFLAG_RW,
1145 	    &rack_per_upper_bound_ss, 0,
1146 	    "Rack timely highest percentage we allow GP multiplier in SS to raise to (0 is no upperbound)");
1147 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1148 	    SYSCTL_CHILDREN(rack_timely),
1149 	    OID_AUTO, "upperboundca", CTLFLAG_RW,
1150 	    &rack_per_upper_bound_ca, 0,
1151 	    "Rack timely highest percentage we allow GP multiplier to CA raise to (0 is no upperbound)");
1152 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1153 	    SYSCTL_CHILDREN(rack_timely),
1154 	    OID_AUTO, "dynamicgp", CTLFLAG_RW,
1155 	    &rack_do_dyn_mul, 0,
1156 	    "Rack timely do we enable dynmaic timely goodput by default");
1157 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1158 	    SYSCTL_CHILDREN(rack_timely),
1159 	    OID_AUTO, "no_rec_red", CTLFLAG_RW,
1160 	    &rack_gp_no_rec_chg, 1,
1161 	    "Rack timely do we prohibit the recovery multiplier from being lowered");
1162 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1163 	    SYSCTL_CHILDREN(rack_timely),
1164 	    OID_AUTO, "red_clear_cnt", CTLFLAG_RW,
1165 	    &rack_timely_dec_clear, 6,
1166 	    "Rack timely what threshold do we count to before another boost during b/w decent");
1167 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1168 	    SYSCTL_CHILDREN(rack_timely),
1169 	    OID_AUTO, "max_push_rise", CTLFLAG_RW,
1170 	    &rack_timely_max_push_rise, 3,
1171 	    "Rack timely how many times do we push up with b/w increase");
1172 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1173 	    SYSCTL_CHILDREN(rack_timely),
1174 	    OID_AUTO, "max_push_drop", CTLFLAG_RW,
1175 	    &rack_timely_max_push_drop, 3,
1176 	    "Rack timely how many times do we push back on b/w decent");
1177 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1178 	    SYSCTL_CHILDREN(rack_timely),
1179 	    OID_AUTO, "min_segs", CTLFLAG_RW,
1180 	    &rack_timely_min_segs, 4,
1181 	    "Rack timely when setting the cwnd what is the min num segments");
1182 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1183 	    SYSCTL_CHILDREN(rack_timely),
1184 	    OID_AUTO, "noback_max", CTLFLAG_RW,
1185 	    &rack_use_max_for_nobackoff, 0,
1186 	    "Rack timely when deciding if to backoff on a loss, do we use under max rtt else min");
1187 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1188 	    SYSCTL_CHILDREN(rack_timely),
1189 	    OID_AUTO, "interim_timely_only", CTLFLAG_RW,
1190 	    &rack_timely_int_timely_only, 0,
1191 	    "Rack timely when doing interim timely's do we only do timely (no b/w consideration)");
1192 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1193 	    SYSCTL_CHILDREN(rack_timely),
1194 	    OID_AUTO, "nonstop", CTLFLAG_RW,
1195 	    &rack_timely_no_stopping, 0,
1196 	    "Rack timely don't stop increase");
1197 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1198 	    SYSCTL_CHILDREN(rack_timely),
1199 	    OID_AUTO, "dec_raise_thresh", CTLFLAG_RW,
1200 	    &rack_down_raise_thresh, 100,
1201 	    "If the CA or SS is below this threshold raise on the first 3 b/w lowers (0=always)");
1202 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1203 	    SYSCTL_CHILDREN(rack_timely),
1204 	    OID_AUTO, "bottom_drag_segs", CTLFLAG_RW,
1205 	    &rack_req_segs, 1,
1206 	    "Bottom dragging if not these many segments outstanding and room");
1207 
1208 	/* TLP and Rack related parameters */
1209 	rack_tlp = SYSCTL_ADD_NODE(&rack_sysctl_ctx,
1210 	    SYSCTL_CHILDREN(rack_sysctl_root),
1211 	    OID_AUTO,
1212 	    "tlp",
1213 	    CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
1214 	    "TLP and Rack related Controls");
1215 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1216 	    SYSCTL_CHILDREN(rack_tlp),
1217 	    OID_AUTO, "use_rrr", CTLFLAG_RW,
1218 	    &use_rack_rr, 1,
1219 	    "Do we use Rack Rapid Recovery");
1220 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1221 	    SYSCTL_CHILDREN(rack_tlp),
1222 	    OID_AUTO, "post_rec_labc", CTLFLAG_RW,
1223 	    &rack_max_abc_post_recovery, 2,
1224 	    "Since we do early recovery, do we override the l_abc to a value, if so what?");
1225 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1226 	    SYSCTL_CHILDREN(rack_tlp),
1227 	    OID_AUTO, "nonrxt_use_cr", CTLFLAG_RW,
1228 	    &rack_non_rxt_use_cr, 0,
1229 	    "Do we use ss/ca rate if in recovery we are transmitting a new data chunk");
1230 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1231 	    SYSCTL_CHILDREN(rack_tlp),
1232 	    OID_AUTO, "tlpmethod", CTLFLAG_RW,
1233 	    &rack_tlp_threshold_use, TLP_USE_TWO_ONE,
1234 	    "What method do we do for TLP time calc 0=no-de-ack-comp, 1=ID, 2=2.1, 3=2.2");
1235 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1236 	    SYSCTL_CHILDREN(rack_tlp),
1237 	    OID_AUTO, "limit", CTLFLAG_RW,
1238 	    &rack_tlp_limit, 2,
1239 	    "How many TLP's can be sent without sending new data");
1240 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1241 	    SYSCTL_CHILDREN(rack_tlp),
1242 	    OID_AUTO, "use_greater", CTLFLAG_RW,
1243 	    &rack_tlp_use_greater, 1,
1244 	    "Should we use the rack_rtt time if its greater than srtt");
1245 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1246 	    SYSCTL_CHILDREN(rack_tlp),
1247 	    OID_AUTO, "tlpminto", CTLFLAG_RW,
1248 	    &rack_tlp_min, 10000,
1249 	    "TLP minimum timeout per the specification (in microseconds)");
1250 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1251 	    SYSCTL_CHILDREN(rack_tlp),
1252 	    OID_AUTO, "send_oldest", CTLFLAG_RW,
1253 	    &rack_always_send_oldest, 0,
1254 	    "Should we always send the oldest TLP and RACK-TLP");
1255 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1256 	    SYSCTL_CHILDREN(rack_tlp),
1257 	    OID_AUTO, "rack_tlimit", CTLFLAG_RW,
1258 	    &rack_limited_retran, 0,
1259 	    "How many times can a rack timeout drive out sends");
1260 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1261 	    SYSCTL_CHILDREN(rack_tlp),
1262 	    OID_AUTO, "tlp_cwnd_flag", CTLFLAG_RW,
1263 	    &rack_lower_cwnd_at_tlp, 0,
1264 	    "When a TLP completes a retran should we enter recovery");
1265 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1266 	    SYSCTL_CHILDREN(rack_tlp),
1267 	    OID_AUTO, "reorder_thresh", CTLFLAG_RW,
1268 	    &rack_reorder_thresh, 2,
1269 	    "What factor for rack will be added when seeing reordering (shift right)");
1270 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1271 	    SYSCTL_CHILDREN(rack_tlp),
1272 	    OID_AUTO, "rtt_tlp_thresh", CTLFLAG_RW,
1273 	    &rack_tlp_thresh, 1,
1274 	    "What divisor for TLP rtt/retran will be added (1=rtt, 2=1/2 rtt etc)");
1275 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1276 	    SYSCTL_CHILDREN(rack_tlp),
1277 	    OID_AUTO, "reorder_fade", CTLFLAG_RW,
1278 	    &rack_reorder_fade, 60000000,
1279 	    "Does reorder detection fade, if so how many microseconds (0 means never)");
1280 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1281 	    SYSCTL_CHILDREN(rack_tlp),
1282 	    OID_AUTO, "pktdelay", CTLFLAG_RW,
1283 	    &rack_pkt_delay, 1000,
1284 	    "Extra RACK time (in microseconds) besides reordering thresh");
1285 
1286 	/* Timer related controls */
1287 	rack_timers = SYSCTL_ADD_NODE(&rack_sysctl_ctx,
1288 	    SYSCTL_CHILDREN(rack_sysctl_root),
1289 	    OID_AUTO,
1290 	    "timers",
1291 	    CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
1292 	    "Timer related controls");
1293 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
1294 	    SYSCTL_CHILDREN(rack_timers),
1295 	    OID_AUTO, "persmin", CTLFLAG_RW,
1296 	    &rack_persist_min, 250000,
1297 	    "What is the minimum time in microseconds between persists");
1298 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
1299 	    SYSCTL_CHILDREN(rack_timers),
1300 	    OID_AUTO, "persmax", CTLFLAG_RW,
1301 	    &rack_persist_max, 2000000,
1302 	    "What is the largest delay in microseconds between persists");
1303 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1304 	    SYSCTL_CHILDREN(rack_timers),
1305 	    OID_AUTO, "delayed_ack", CTLFLAG_RW,
1306 	    &rack_delayed_ack_time, 40000,
1307 	    "Delayed ack time (40ms in microseconds)");
1308 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1309 	    SYSCTL_CHILDREN(rack_timers),
1310 	    OID_AUTO, "minrto", CTLFLAG_RW,
1311 	    &rack_rto_min, 30000,
1312 	    "Minimum RTO in microseconds -- set with caution below 1000 due to TLP");
1313 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1314 	    SYSCTL_CHILDREN(rack_timers),
1315 	    OID_AUTO, "maxrto", CTLFLAG_RW,
1316 	    &rack_rto_max, 4000000,
1317 	    "Maximum RTO in microseconds -- should be at least as large as min_rto");
1318 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1319 	    SYSCTL_CHILDREN(rack_timers),
1320 	    OID_AUTO, "minto", CTLFLAG_RW,
1321 	    &rack_min_to, 1000,
1322 	    "Minimum rack timeout in microseconds");
1323 	/* Measure controls */
1324 	rack_measure = SYSCTL_ADD_NODE(&rack_sysctl_ctx,
1325 	    SYSCTL_CHILDREN(rack_sysctl_root),
1326 	    OID_AUTO,
1327 	    "measure",
1328 	    CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
1329 	    "Measure related controls");
1330 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1331 	    SYSCTL_CHILDREN(rack_measure),
1332 	    OID_AUTO, "wma_divisor", CTLFLAG_RW,
1333 	    &rack_wma_divisor, 8,
1334 	    "When doing b/w calculation what is the  divisor for the WMA");
1335 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1336 	    SYSCTL_CHILDREN(rack_measure),
1337 	    OID_AUTO, "end_cwnd", CTLFLAG_RW,
1338 	    &rack_cwnd_block_ends_measure, 0,
1339 	    "Does a cwnd just-return end the measurement window (app limited)");
1340 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1341 	    SYSCTL_CHILDREN(rack_measure),
1342 	    OID_AUTO, "end_rwnd", CTLFLAG_RW,
1343 	    &rack_rwnd_block_ends_measure, 0,
1344 	    "Does an rwnd just-return end the measurement window (app limited -- not persists)");
1345 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
1346 	    SYSCTL_CHILDREN(rack_measure),
1347 	    OID_AUTO, "min_target", CTLFLAG_RW,
1348 	    &rack_def_data_window, 20,
1349 	    "What is the minimum target window (in mss) for a GP measurements");
1350 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
1351 	    SYSCTL_CHILDREN(rack_measure),
1352 	    OID_AUTO, "goal_bdp", CTLFLAG_RW,
1353 	    &rack_goal_bdp, 2,
1354 	    "What is the goal BDP to measure");
1355 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
1356 	    SYSCTL_CHILDREN(rack_measure),
1357 	    OID_AUTO, "min_srtts", CTLFLAG_RW,
1358 	    &rack_min_srtts, 1,
1359 	    "What is the goal BDP to measure");
1360 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
1361 	    SYSCTL_CHILDREN(rack_measure),
1362 	    OID_AUTO, "min_measure_tim", CTLFLAG_RW,
1363 	    &rack_min_measure_usec, 0,
1364 	    "What is the Minimum time time for a measurement if 0, this is off");
1365 	/* Features */
1366 	rack_features = SYSCTL_ADD_NODE(&rack_sysctl_ctx,
1367 	    SYSCTL_CHILDREN(rack_sysctl_root),
1368 	    OID_AUTO,
1369 	    "features",
1370 	    CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
1371 	    "Feature controls");
1372 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1373 	    SYSCTL_CHILDREN(rack_features),
1374 	    OID_AUTO, "cmpack", CTLFLAG_RW,
1375 	    &rack_use_cmp_acks, 1,
1376 	    "Should RACK have LRO send compressed acks");
1377 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1378 	    SYSCTL_CHILDREN(rack_features),
1379 	    OID_AUTO, "fsb", CTLFLAG_RW,
1380 	    &rack_use_fsb, 1,
1381 	    "Should RACK use the fast send block?");
1382 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1383 	    SYSCTL_CHILDREN(rack_features),
1384 	    OID_AUTO, "rfo", CTLFLAG_RW,
1385 	    &rack_use_rfo, 1,
1386 	    "Should RACK use rack_fast_output()?");
1387 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1388 	    SYSCTL_CHILDREN(rack_features),
1389 	    OID_AUTO, "rsmrfo", CTLFLAG_RW,
1390 	    &rack_use_rsm_rfo, 1,
1391 	    "Should RACK use rack_fast_rsm_output()?");
1392 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1393 	    SYSCTL_CHILDREN(rack_features),
1394 	    OID_AUTO, "non_paced_lro_queue", CTLFLAG_RW,
1395 	    &rack_enable_mqueue_for_nonpaced, 0,
1396 	    "Should RACK use mbuf queuing for non-paced connections");
1397 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1398 	    SYSCTL_CHILDREN(rack_features),
1399 	    OID_AUTO, "hystartplusplus", CTLFLAG_RW,
1400 	    &rack_do_hystart, 0,
1401 	    "Should RACK enable HyStart++ on connections?");
1402 	/* Misc rack controls */
1403 	rack_misc = SYSCTL_ADD_NODE(&rack_sysctl_ctx,
1404 	    SYSCTL_CHILDREN(rack_sysctl_root),
1405 	    OID_AUTO,
1406 	    "misc",
1407 	    CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
1408 	    "Misc related controls");
1409 #ifdef TCP_ACCOUNTING
1410 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1411 	    SYSCTL_CHILDREN(rack_misc),
1412 	    OID_AUTO, "tcp_acct", CTLFLAG_RW,
1413 	    &rack_tcp_accounting, 0,
1414 	    "Should we turn on TCP accounting for all rack sessions?");
1415 #endif
1416 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1417 	    SYSCTL_CHILDREN(rack_misc),
1418 	    OID_AUTO, "apply_rtt_with_low_conf", CTLFLAG_RW,
1419 	    &rack_apply_rtt_with_reduced_conf, 0,
1420 	    "When a persist or keep-alive probe is not answered do we calculate rtt on subsequent answers?");
1421 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1422 	    SYSCTL_CHILDREN(rack_misc),
1423 	    OID_AUTO, "rack_dsack_ctl", CTLFLAG_RW,
1424 	    &rack_dsack_std_based, 3,
1425 	    "How do we process dsack with respect to rack timers, bit field, 3 is standards based?");
1426 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1427 	    SYSCTL_CHILDREN(rack_misc),
1428 	    OID_AUTO, "prr_addback_max", CTLFLAG_RW,
1429 	    &rack_prr_addbackmax, 2,
1430 	    "What is the maximum number of MSS we allow to be added back if prr can't send all its data?");
1431 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1432 	    SYSCTL_CHILDREN(rack_misc),
1433 	    OID_AUTO, "stats_gets_ms", CTLFLAG_RW,
1434 	    &rack_stats_gets_ms_rtt, 1,
1435 	    "What do we feed the stats framework (1 = ms_rtt, 0 = us_rtt, 2 = ms_rtt from hdwr, > 2 usec rtt from hdwr)?");
1436 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1437 	    SYSCTL_CHILDREN(rack_misc),
1438 	    OID_AUTO, "clientlowbuf", CTLFLAG_RW,
1439 	    &rack_client_low_buf, 0,
1440 	    "Client low buffer level (below this we are more aggressive in DGP exiting recovery (0 = off)?");
1441 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1442 	    SYSCTL_CHILDREN(rack_misc),
1443 	    OID_AUTO, "defprofile", CTLFLAG_RW,
1444 	    &rack_def_profile, 0,
1445 	    "Should RACK use a default profile (0=no, num == profile num)?");
1446 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1447 	    SYSCTL_CHILDREN(rack_misc),
1448 	    OID_AUTO, "shared_cwnd", CTLFLAG_RW,
1449 	    &rack_enable_shared_cwnd, 1,
1450 	    "Should RACK try to use the shared cwnd on connections where allowed");
1451 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1452 	    SYSCTL_CHILDREN(rack_misc),
1453 	    OID_AUTO, "limits_on_scwnd", CTLFLAG_RW,
1454 	    &rack_limits_scwnd, 1,
1455 	    "Should RACK place low end time limits on the shared cwnd feature");
1456 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1457 	    SYSCTL_CHILDREN(rack_misc),
1458 	    OID_AUTO, "iMac_dack", CTLFLAG_RW,
1459 	    &rack_use_imac_dack, 0,
1460 	    "Should RACK try to emulate iMac delayed ack");
1461 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1462 	    SYSCTL_CHILDREN(rack_misc),
1463 	    OID_AUTO, "no_prr", CTLFLAG_RW,
1464 	    &rack_disable_prr, 0,
1465 	    "Should RACK not use prr and only pace (must have pacing on)");
1466 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1467 	    SYSCTL_CHILDREN(rack_misc),
1468 	    OID_AUTO, "bb_verbose", CTLFLAG_RW,
1469 	    &rack_verbose_logging, 0,
1470 	    "Should RACK black box logging be verbose");
1471 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1472 	    SYSCTL_CHILDREN(rack_misc),
1473 	    OID_AUTO, "data_after_close", CTLFLAG_RW,
1474 	    &rack_ignore_data_after_close, 1,
1475 	    "Do we hold off sending a RST until all pending data is ack'd");
1476 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1477 	    SYSCTL_CHILDREN(rack_misc),
1478 	    OID_AUTO, "no_sack_needed", CTLFLAG_RW,
1479 	    &rack_sack_not_required, 1,
1480 	    "Do we allow rack to run on connections not supporting SACK");
1481 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1482 	    SYSCTL_CHILDREN(rack_misc),
1483 	    OID_AUTO, "prr_sendalot", CTLFLAG_RW,
1484 	    &rack_send_a_lot_in_prr, 1,
1485 	    "Send a lot in prr");
1486 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1487 	    SYSCTL_CHILDREN(rack_misc),
1488 	    OID_AUTO, "autoscale", CTLFLAG_RW,
1489 	    &rack_autosndbuf_inc, 20,
1490 	    "What percentage should rack scale up its snd buffer by?");
1491 	/* Sack Attacker detection stuff */
1492 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
1493 	    SYSCTL_CHILDREN(rack_attack),
1494 	    OID_AUTO, "detect_highsackratio", CTLFLAG_RW,
1495 	    &rack_highest_sack_thresh_seen, 0,
1496 	    "Highest sack to ack ratio seen");
1497 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
1498 	    SYSCTL_CHILDREN(rack_attack),
1499 	    OID_AUTO, "detect_highmoveratio", CTLFLAG_RW,
1500 	    &rack_highest_move_thresh_seen, 0,
1501 	    "Highest move to non-move ratio seen");
1502 	rack_ack_total = counter_u64_alloc(M_WAITOK);
1503 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1504 	    SYSCTL_CHILDREN(rack_attack),
1505 	    OID_AUTO, "acktotal", CTLFLAG_RD,
1506 	    &rack_ack_total,
1507 	    "Total number of Ack's");
1508 	rack_express_sack = counter_u64_alloc(M_WAITOK);
1509 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1510 	    SYSCTL_CHILDREN(rack_attack),
1511 	    OID_AUTO, "exp_sacktotal", CTLFLAG_RD,
1512 	    &rack_express_sack,
1513 	    "Total expresss number of Sack's");
1514 	rack_sack_total = counter_u64_alloc(M_WAITOK);
1515 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1516 	    SYSCTL_CHILDREN(rack_attack),
1517 	    OID_AUTO, "sacktotal", CTLFLAG_RD,
1518 	    &rack_sack_total,
1519 	    "Total number of SACKs");
1520 	rack_move_none = counter_u64_alloc(M_WAITOK);
1521 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1522 	    SYSCTL_CHILDREN(rack_attack),
1523 	    OID_AUTO, "move_none", CTLFLAG_RD,
1524 	    &rack_move_none,
1525 	    "Total number of SACK index reuse of positions under threshold");
1526 	rack_move_some = counter_u64_alloc(M_WAITOK);
1527 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1528 	    SYSCTL_CHILDREN(rack_attack),
1529 	    OID_AUTO, "move_some", CTLFLAG_RD,
1530 	    &rack_move_some,
1531 	    "Total number of SACK index reuse of positions over threshold");
1532 	rack_sack_attacks_detected = counter_u64_alloc(M_WAITOK);
1533 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1534 	    SYSCTL_CHILDREN(rack_attack),
1535 	    OID_AUTO, "attacks", CTLFLAG_RD,
1536 	    &rack_sack_attacks_detected,
1537 	    "Total number of SACK attackers that had sack disabled");
1538 	rack_sack_attacks_reversed = counter_u64_alloc(M_WAITOK);
1539 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1540 	    SYSCTL_CHILDREN(rack_attack),
1541 	    OID_AUTO, "reversed", CTLFLAG_RD,
1542 	    &rack_sack_attacks_reversed,
1543 	    "Total number of SACK attackers that were later determined false positive");
1544 	rack_sack_used_next_merge = counter_u64_alloc(M_WAITOK);
1545 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1546 	    SYSCTL_CHILDREN(rack_attack),
1547 	    OID_AUTO, "nextmerge", CTLFLAG_RD,
1548 	    &rack_sack_used_next_merge,
1549 	    "Total number of times we used the next merge");
1550 	rack_sack_used_prev_merge = counter_u64_alloc(M_WAITOK);
1551 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1552 	    SYSCTL_CHILDREN(rack_attack),
1553 	    OID_AUTO, "prevmerge", CTLFLAG_RD,
1554 	    &rack_sack_used_prev_merge,
1555 	    "Total number of times we used the prev merge");
1556 	/* Counters */
1557 	rack_fto_send = counter_u64_alloc(M_WAITOK);
1558 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1559 	    SYSCTL_CHILDREN(rack_counters),
1560 	    OID_AUTO, "fto_send", CTLFLAG_RD,
1561 	    &rack_fto_send, "Total number of rack_fast_output sends");
1562 	rack_fto_rsm_send = counter_u64_alloc(M_WAITOK);
1563 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1564 	    SYSCTL_CHILDREN(rack_counters),
1565 	    OID_AUTO, "fto_rsm_send", CTLFLAG_RD,
1566 	    &rack_fto_rsm_send, "Total number of rack_fast_rsm_output sends");
1567 	rack_nfto_resend = counter_u64_alloc(M_WAITOK);
1568 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1569 	    SYSCTL_CHILDREN(rack_counters),
1570 	    OID_AUTO, "nfto_resend", CTLFLAG_RD,
1571 	    &rack_nfto_resend, "Total number of rack_output retransmissions");
1572 	rack_non_fto_send = counter_u64_alloc(M_WAITOK);
1573 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1574 	    SYSCTL_CHILDREN(rack_counters),
1575 	    OID_AUTO, "nfto_send", CTLFLAG_RD,
1576 	    &rack_non_fto_send, "Total number of rack_output first sends");
1577 	rack_extended_rfo = counter_u64_alloc(M_WAITOK);
1578 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1579 	    SYSCTL_CHILDREN(rack_counters),
1580 	    OID_AUTO, "rfo_extended", CTLFLAG_RD,
1581 	    &rack_extended_rfo, "Total number of times we extended rfo");
1582 
1583 	rack_hw_pace_init_fail = counter_u64_alloc(M_WAITOK);
1584 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1585 	    SYSCTL_CHILDREN(rack_counters),
1586 	    OID_AUTO, "hwpace_init_fail", CTLFLAG_RD,
1587 	    &rack_hw_pace_init_fail, "Total number of times we failed to initialize hw pacing");
1588 	rack_hw_pace_lost = counter_u64_alloc(M_WAITOK);
1589 
1590 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1591 	    SYSCTL_CHILDREN(rack_counters),
1592 	    OID_AUTO, "hwpace_lost", CTLFLAG_RD,
1593 	    &rack_hw_pace_lost, "Total number of times we failed to initialize hw pacing");
1594 	rack_tlp_tot = counter_u64_alloc(M_WAITOK);
1595 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1596 	    SYSCTL_CHILDREN(rack_counters),
1597 	    OID_AUTO, "tlp_to_total", CTLFLAG_RD,
1598 	    &rack_tlp_tot,
1599 	    "Total number of tail loss probe expirations");
1600 	rack_tlp_newdata = counter_u64_alloc(M_WAITOK);
1601 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1602 	    SYSCTL_CHILDREN(rack_counters),
1603 	    OID_AUTO, "tlp_new", CTLFLAG_RD,
1604 	    &rack_tlp_newdata,
1605 	    "Total number of tail loss probe sending new data");
1606 	rack_tlp_retran = counter_u64_alloc(M_WAITOK);
1607 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1608 	    SYSCTL_CHILDREN(rack_counters),
1609 	    OID_AUTO, "tlp_retran", CTLFLAG_RD,
1610 	    &rack_tlp_retran,
1611 	    "Total number of tail loss probe sending retransmitted data");
1612 	rack_tlp_retran_bytes = counter_u64_alloc(M_WAITOK);
1613 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1614 	    SYSCTL_CHILDREN(rack_counters),
1615 	    OID_AUTO, "tlp_retran_bytes", CTLFLAG_RD,
1616 	    &rack_tlp_retran_bytes,
1617 	    "Total bytes of tail loss probe sending retransmitted data");
1618 	rack_to_tot = counter_u64_alloc(M_WAITOK);
1619 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1620 	    SYSCTL_CHILDREN(rack_counters),
1621 	    OID_AUTO, "rack_to_tot", CTLFLAG_RD,
1622 	    &rack_to_tot,
1623 	    "Total number of times the rack to expired");
1624 	rack_saw_enobuf = counter_u64_alloc(M_WAITOK);
1625 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1626 	    SYSCTL_CHILDREN(rack_counters),
1627 	    OID_AUTO, "saw_enobufs", CTLFLAG_RD,
1628 	    &rack_saw_enobuf,
1629 	    "Total number of times a sends returned enobuf for non-hdwr paced connections");
1630 	rack_saw_enobuf_hw = counter_u64_alloc(M_WAITOK);
1631 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1632 	    SYSCTL_CHILDREN(rack_counters),
1633 	    OID_AUTO, "saw_enobufs_hw", CTLFLAG_RD,
1634 	    &rack_saw_enobuf_hw,
1635 	    "Total number of times a send returned enobuf for hdwr paced connections");
1636 	rack_saw_enetunreach = counter_u64_alloc(M_WAITOK);
1637 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1638 	    SYSCTL_CHILDREN(rack_counters),
1639 	    OID_AUTO, "saw_enetunreach", CTLFLAG_RD,
1640 	    &rack_saw_enetunreach,
1641 	    "Total number of times a send received a enetunreachable");
1642 	rack_hot_alloc = counter_u64_alloc(M_WAITOK);
1643 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1644 	    SYSCTL_CHILDREN(rack_counters),
1645 	    OID_AUTO, "alloc_hot", CTLFLAG_RD,
1646 	    &rack_hot_alloc,
1647 	    "Total allocations from the top of our list");
1648 	rack_to_alloc = counter_u64_alloc(M_WAITOK);
1649 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1650 	    SYSCTL_CHILDREN(rack_counters),
1651 	    OID_AUTO, "allocs", CTLFLAG_RD,
1652 	    &rack_to_alloc,
1653 	    "Total allocations of tracking structures");
1654 	rack_to_alloc_hard = counter_u64_alloc(M_WAITOK);
1655 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1656 	    SYSCTL_CHILDREN(rack_counters),
1657 	    OID_AUTO, "allochard", CTLFLAG_RD,
1658 	    &rack_to_alloc_hard,
1659 	    "Total allocations done with sleeping the hard way");
1660 	rack_to_alloc_emerg = counter_u64_alloc(M_WAITOK);
1661 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1662 	    SYSCTL_CHILDREN(rack_counters),
1663 	    OID_AUTO, "allocemerg", CTLFLAG_RD,
1664 	    &rack_to_alloc_emerg,
1665 	    "Total allocations done from emergency cache");
1666 	rack_to_alloc_limited = counter_u64_alloc(M_WAITOK);
1667 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1668 	    SYSCTL_CHILDREN(rack_counters),
1669 	    OID_AUTO, "alloc_limited", CTLFLAG_RD,
1670 	    &rack_to_alloc_limited,
1671 	    "Total allocations dropped due to limit");
1672 	rack_alloc_limited_conns = counter_u64_alloc(M_WAITOK);
1673 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1674 	    SYSCTL_CHILDREN(rack_counters),
1675 	    OID_AUTO, "alloc_limited_conns", CTLFLAG_RD,
1676 	    &rack_alloc_limited_conns,
1677 	    "Connections with allocations dropped due to limit");
1678 	rack_split_limited = counter_u64_alloc(M_WAITOK);
1679 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1680 	    SYSCTL_CHILDREN(rack_counters),
1681 	    OID_AUTO, "split_limited", CTLFLAG_RD,
1682 	    &rack_split_limited,
1683 	    "Split allocations dropped due to limit");
1684 	rack_persists_sends = counter_u64_alloc(M_WAITOK);
1685 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1686 	    SYSCTL_CHILDREN(rack_counters),
1687 	    OID_AUTO, "persist_sends", CTLFLAG_RD,
1688 	    &rack_persists_sends,
1689 	    "Number of times we sent a persist probe");
1690 	rack_persists_acks = counter_u64_alloc(M_WAITOK);
1691 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1692 	    SYSCTL_CHILDREN(rack_counters),
1693 	    OID_AUTO, "persist_acks", CTLFLAG_RD,
1694 	    &rack_persists_acks,
1695 	    "Number of times a persist probe was acked");
1696 	rack_persists_loss = counter_u64_alloc(M_WAITOK);
1697 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1698 	    SYSCTL_CHILDREN(rack_counters),
1699 	    OID_AUTO, "persist_loss", CTLFLAG_RD,
1700 	    &rack_persists_loss,
1701 	    "Number of times we detected a lost persist probe (no ack)");
1702 	rack_persists_lost_ends = counter_u64_alloc(M_WAITOK);
1703 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1704 	    SYSCTL_CHILDREN(rack_counters),
1705 	    OID_AUTO, "persist_loss_ends", CTLFLAG_RD,
1706 	    &rack_persists_lost_ends,
1707 	    "Number of lost persist probe (no ack) that the run ended with a PERSIST abort");
1708 #ifdef INVARIANTS
1709 	rack_adjust_map_bw = counter_u64_alloc(M_WAITOK);
1710 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1711 	    SYSCTL_CHILDREN(rack_counters),
1712 	    OID_AUTO, "map_adjust_req", CTLFLAG_RD,
1713 	    &rack_adjust_map_bw,
1714 	    "Number of times we hit the case where the sb went up and down on a sendmap entry");
1715 #endif
1716 	rack_multi_single_eq = counter_u64_alloc(M_WAITOK);
1717 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1718 	    SYSCTL_CHILDREN(rack_counters),
1719 	    OID_AUTO, "cmp_ack_equiv", CTLFLAG_RD,
1720 	    &rack_multi_single_eq,
1721 	    "Number of compressed acks total represented");
1722 	rack_proc_non_comp_ack = counter_u64_alloc(M_WAITOK);
1723 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1724 	    SYSCTL_CHILDREN(rack_counters),
1725 	    OID_AUTO, "cmp_ack_not", CTLFLAG_RD,
1726 	    &rack_proc_non_comp_ack,
1727 	    "Number of non compresseds acks that we processed");
1728 
1729 
1730 	rack_sack_proc_all = counter_u64_alloc(M_WAITOK);
1731 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1732 	    SYSCTL_CHILDREN(rack_counters),
1733 	    OID_AUTO, "sack_long", CTLFLAG_RD,
1734 	    &rack_sack_proc_all,
1735 	    "Total times we had to walk whole list for sack processing");
1736 	rack_sack_proc_restart = counter_u64_alloc(M_WAITOK);
1737 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1738 	    SYSCTL_CHILDREN(rack_counters),
1739 	    OID_AUTO, "sack_restart", CTLFLAG_RD,
1740 	    &rack_sack_proc_restart,
1741 	    "Total times we had to walk whole list due to a restart");
1742 	rack_sack_proc_short = counter_u64_alloc(M_WAITOK);
1743 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1744 	    SYSCTL_CHILDREN(rack_counters),
1745 	    OID_AUTO, "sack_short", CTLFLAG_RD,
1746 	    &rack_sack_proc_short,
1747 	    "Total times we took shortcut for sack processing");
1748 	rack_sack_skipped_acked = counter_u64_alloc(M_WAITOK);
1749 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1750 	    SYSCTL_CHILDREN(rack_attack),
1751 	    OID_AUTO, "skipacked", CTLFLAG_RD,
1752 	    &rack_sack_skipped_acked,
1753 	    "Total number of times we skipped previously sacked");
1754 	rack_sack_splits = counter_u64_alloc(M_WAITOK);
1755 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1756 	    SYSCTL_CHILDREN(rack_attack),
1757 	    OID_AUTO, "ofsplit", CTLFLAG_RD,
1758 	    &rack_sack_splits,
1759 	    "Total number of times we did the old fashion tree split");
1760 	rack_input_idle_reduces = counter_u64_alloc(M_WAITOK);
1761 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1762 	    SYSCTL_CHILDREN(rack_counters),
1763 	    OID_AUTO, "idle_reduce_oninput", CTLFLAG_RD,
1764 	    &rack_input_idle_reduces,
1765 	    "Total number of idle reductions on input");
1766 	rack_collapsed_win_seen = counter_u64_alloc(M_WAITOK);
1767 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1768 	    SYSCTL_CHILDREN(rack_counters),
1769 	    OID_AUTO, "collapsed_win_seen", CTLFLAG_RD,
1770 	    &rack_collapsed_win_seen,
1771 	    "Total number of collapsed window events seen (where our window shrinks)");
1772 
1773 	rack_collapsed_win = counter_u64_alloc(M_WAITOK);
1774 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1775 	    SYSCTL_CHILDREN(rack_counters),
1776 	    OID_AUTO, "collapsed_win", CTLFLAG_RD,
1777 	    &rack_collapsed_win,
1778 	    "Total number of collapsed window events where we mark packets");
1779 	rack_collapsed_win_rxt = counter_u64_alloc(M_WAITOK);
1780 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1781 	    SYSCTL_CHILDREN(rack_counters),
1782 	    OID_AUTO, "collapsed_win_rxt", CTLFLAG_RD,
1783 	    &rack_collapsed_win_rxt,
1784 	    "Total number of packets that were retransmitted");
1785 	rack_collapsed_win_rxt_bytes = counter_u64_alloc(M_WAITOK);
1786 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1787 	    SYSCTL_CHILDREN(rack_counters),
1788 	    OID_AUTO, "collapsed_win_bytes", CTLFLAG_RD,
1789 	    &rack_collapsed_win_rxt_bytes,
1790 	    "Total number of bytes that were retransmitted");
1791 	rack_try_scwnd = counter_u64_alloc(M_WAITOK);
1792 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1793 	    SYSCTL_CHILDREN(rack_counters),
1794 	    OID_AUTO, "tried_scwnd", CTLFLAG_RD,
1795 	    &rack_try_scwnd,
1796 	    "Total number of scwnd attempts");
1797 	COUNTER_ARRAY_ALLOC(rack_out_size, TCP_MSS_ACCT_SIZE, M_WAITOK);
1798 	SYSCTL_ADD_COUNTER_U64_ARRAY(&rack_sysctl_ctx, SYSCTL_CHILDREN(rack_sysctl_root),
1799 	    OID_AUTO, "outsize", CTLFLAG_RD,
1800 	    rack_out_size, TCP_MSS_ACCT_SIZE, "MSS send sizes");
1801 	COUNTER_ARRAY_ALLOC(rack_opts_arry, RACK_OPTS_SIZE, M_WAITOK);
1802 	SYSCTL_ADD_COUNTER_U64_ARRAY(&rack_sysctl_ctx, SYSCTL_CHILDREN(rack_sysctl_root),
1803 	    OID_AUTO, "opts", CTLFLAG_RD,
1804 	    rack_opts_arry, RACK_OPTS_SIZE, "RACK Option Stats");
1805 	SYSCTL_ADD_PROC(&rack_sysctl_ctx,
1806 	    SYSCTL_CHILDREN(rack_sysctl_root),
1807 	    OID_AUTO, "clear", CTLTYPE_UINT | CTLFLAG_RW | CTLFLAG_MPSAFE,
1808 	    &rack_clear_counter, 0, sysctl_rack_clear, "IU", "Clear counters");
1809 }
1810 
1811 static __inline int
1812 rb_map_cmp(struct rack_sendmap *b, struct rack_sendmap *a)
1813 {
1814 	if (SEQ_GEQ(b->r_start, a->r_start) &&
1815 	    SEQ_LT(b->r_start, a->r_end)) {
1816 		/*
1817 		 * The entry b is within the
1818 		 * block a. i.e.:
1819 		 * a --   |-------------|
1820 		 * b --   |----|
1821 		 * <or>
1822 		 * b --       |------|
1823 		 * <or>
1824 		 * b --       |-----------|
1825 		 */
1826 		return (0);
1827 	} else if (SEQ_GEQ(b->r_start, a->r_end)) {
1828 		/*
1829 		 * b falls as either the next
1830 		 * sequence block after a so a
1831 		 * is said to be smaller than b.
1832 		 * i.e:
1833 		 * a --   |------|
1834 		 * b --          |--------|
1835 		 * or
1836 		 * b --              |-----|
1837 		 */
1838 		return (1);
1839 	}
1840 	/*
1841 	 * Whats left is where a is
1842 	 * larger than b. i.e:
1843 	 * a --         |-------|
1844 	 * b --  |---|
1845 	 * or even possibly
1846 	 * b --   |--------------|
1847 	 */
1848 	return (-1);
1849 }
1850 
1851 RB_PROTOTYPE(rack_rb_tree_head, rack_sendmap, r_next, rb_map_cmp);
1852 RB_GENERATE(rack_rb_tree_head, rack_sendmap, r_next, rb_map_cmp);
1853 
1854 static uint32_t
1855 rc_init_window(struct tcp_rack *rack)
1856 {
1857 	uint32_t win;
1858 
1859 	if (rack->rc_init_win == 0) {
1860 		/*
1861 		 * Nothing set by the user, use the system stack
1862 		 * default.
1863 		 */
1864 		return (tcp_compute_initwnd(tcp_maxseg(rack->rc_tp)));
1865 	}
1866 	win = ctf_fixed_maxseg(rack->rc_tp) * rack->rc_init_win;
1867 	return (win);
1868 }
1869 
1870 static uint64_t
1871 rack_get_fixed_pacing_bw(struct tcp_rack *rack)
1872 {
1873 	if (IN_FASTRECOVERY(rack->rc_tp->t_flags))
1874 		return (rack->r_ctl.rc_fixed_pacing_rate_rec);
1875 	else if (rack->r_ctl.cwnd_to_use < rack->rc_tp->snd_ssthresh)
1876 		return (rack->r_ctl.rc_fixed_pacing_rate_ss);
1877 	else
1878 		return (rack->r_ctl.rc_fixed_pacing_rate_ca);
1879 }
1880 
1881 static uint64_t
1882 rack_get_bw(struct tcp_rack *rack)
1883 {
1884 	if (rack->use_fixed_rate) {
1885 		/* Return the fixed pacing rate */
1886 		return (rack_get_fixed_pacing_bw(rack));
1887 	}
1888 	if (rack->r_ctl.gp_bw == 0) {
1889 		/*
1890 		 * We have yet no b/w measurement,
1891 		 * if we have a user set initial bw
1892 		 * return it. If we don't have that and
1893 		 * we have an srtt, use the tcp IW (10) to
1894 		 * calculate a fictional b/w over the SRTT
1895 		 * which is more or less a guess. Note
1896 		 * we don't use our IW from rack on purpose
1897 		 * so if we have like IW=30, we are not
1898 		 * calculating a "huge" b/w.
1899 		 */
1900 		uint64_t bw, srtt;
1901 		if (rack->r_ctl.init_rate)
1902 			return (rack->r_ctl.init_rate);
1903 
1904 		/* Has the user set a max peak rate? */
1905 #ifdef NETFLIX_PEAKRATE
1906 		if (rack->rc_tp->t_maxpeakrate)
1907 			return (rack->rc_tp->t_maxpeakrate);
1908 #endif
1909 		/* Ok lets come up with the IW guess, if we have a srtt */
1910 		if (rack->rc_tp->t_srtt == 0) {
1911 			/*
1912 			 * Go with old pacing method
1913 			 * i.e. burst mitigation only.
1914 			 */
1915 			return (0);
1916 		}
1917 		/* Ok lets get the initial TCP win (not racks) */
1918 		bw = tcp_compute_initwnd(tcp_maxseg(rack->rc_tp));
1919 		srtt = (uint64_t)rack->rc_tp->t_srtt;
1920 		bw *= (uint64_t)USECS_IN_SECOND;
1921 		bw /= srtt;
1922 		if (rack->r_ctl.bw_rate_cap && (bw > rack->r_ctl.bw_rate_cap))
1923 			bw = rack->r_ctl.bw_rate_cap;
1924 		return (bw);
1925 	} else {
1926 		uint64_t bw;
1927 
1928 		if (rack->r_ctl.num_measurements >= RACK_REQ_AVG) {
1929 			/* Averaging is done, we can return the value */
1930 			bw = rack->r_ctl.gp_bw;
1931 		} else {
1932 			/* Still doing initial average must calculate */
1933 			bw = rack->r_ctl.gp_bw / rack->r_ctl.num_measurements;
1934 		}
1935 #ifdef NETFLIX_PEAKRATE
1936 		if ((rack->rc_tp->t_maxpeakrate) &&
1937 		    (bw > rack->rc_tp->t_maxpeakrate)) {
1938 			/* The user has set a peak rate to pace at
1939 			 * don't allow us to pace faster than that.
1940 			 */
1941 			return (rack->rc_tp->t_maxpeakrate);
1942 		}
1943 #endif
1944 		if (rack->r_ctl.bw_rate_cap && (bw > rack->r_ctl.bw_rate_cap))
1945 			bw = rack->r_ctl.bw_rate_cap;
1946 		return (bw);
1947 	}
1948 }
1949 
1950 static uint16_t
1951 rack_get_output_gain(struct tcp_rack *rack, struct rack_sendmap *rsm)
1952 {
1953 	if (rack->use_fixed_rate) {
1954 		return (100);
1955 	} else if (rack->in_probe_rtt && (rsm == NULL))
1956 		return (rack->r_ctl.rack_per_of_gp_probertt);
1957 	else if ((IN_FASTRECOVERY(rack->rc_tp->t_flags) &&
1958 		  rack->r_ctl.rack_per_of_gp_rec)) {
1959 		if (rsm) {
1960 			/* a retransmission always use the recovery rate */
1961 			return (rack->r_ctl.rack_per_of_gp_rec);
1962 		} else if (rack->rack_rec_nonrxt_use_cr) {
1963 			/* Directed to use the configured rate */
1964 			goto configured_rate;
1965 		} else if (rack->rack_no_prr &&
1966 			   (rack->r_ctl.rack_per_of_gp_rec > 100)) {
1967 			/* No PRR, lets just use the b/w estimate only */
1968 			return (100);
1969 		} else {
1970 			/*
1971 			 * Here we may have a non-retransmit but we
1972 			 * have no overrides, so just use the recovery
1973 			 * rate (prr is in effect).
1974 			 */
1975 			return (rack->r_ctl.rack_per_of_gp_rec);
1976 		}
1977 	}
1978 configured_rate:
1979 	/* For the configured rate we look at our cwnd vs the ssthresh */
1980 	if (rack->r_ctl.cwnd_to_use < rack->rc_tp->snd_ssthresh)
1981 		return (rack->r_ctl.rack_per_of_gp_ss);
1982 	else
1983 		return (rack->r_ctl.rack_per_of_gp_ca);
1984 }
1985 
1986 static void
1987 rack_log_dsack_event(struct tcp_rack *rack, uint8_t mod, uint32_t flex4, uint32_t flex5, uint32_t flex6)
1988 {
1989 	/*
1990 	 * Types of logs (mod value)
1991 	 * 1 = dsack_persists reduced by 1 via T-O or fast recovery exit.
1992 	 * 2 = a dsack round begins, persist is reset to 16.
1993 	 * 3 = a dsack round ends
1994 	 * 4 = Dsack option increases rack rtt flex5 is the srtt input, flex6 is thresh
1995 	 * 5 = Socket option set changing the control flags rc_rack_tmr_std_based, rc_rack_use_dsack
1996 	 * 6 = Final rack rtt, flex4 is srtt and flex6 is final limited thresh.
1997 	 */
1998 	if (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
1999 		union tcp_log_stackspecific log;
2000 		struct timeval tv;
2001 
2002 		memset(&log, 0, sizeof(log));
2003 		log.u_bbr.flex1 = rack->rc_rack_tmr_std_based;
2004 		log.u_bbr.flex1 <<= 1;
2005 		log.u_bbr.flex1 |= rack->rc_rack_use_dsack;
2006 		log.u_bbr.flex1 <<= 1;
2007 		log.u_bbr.flex1 |= rack->rc_dsack_round_seen;
2008 		log.u_bbr.flex2 = rack->r_ctl.dsack_round_end;
2009 		log.u_bbr.flex3 = rack->r_ctl.num_dsack;
2010 		log.u_bbr.flex4 = flex4;
2011 		log.u_bbr.flex5 = flex5;
2012 		log.u_bbr.flex6 = flex6;
2013 		log.u_bbr.flex7 = rack->r_ctl.dsack_persist;
2014 		log.u_bbr.flex8 = mod;
2015 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
2016 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
2017 		    &rack->rc_inp->inp_socket->so_rcv,
2018 		    &rack->rc_inp->inp_socket->so_snd,
2019 		    RACK_DSACK_HANDLING, 0,
2020 		    0, &log, false, &tv);
2021 	}
2022 }
2023 
2024 static void
2025 rack_log_hdwr_pacing(struct tcp_rack *rack,
2026 		     uint64_t rate, uint64_t hw_rate, int line,
2027 		     int error, uint16_t mod)
2028 {
2029 	if (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
2030 		union tcp_log_stackspecific log;
2031 		struct timeval tv;
2032 		const struct ifnet *ifp;
2033 
2034 		memset(&log, 0, sizeof(log));
2035 		log.u_bbr.flex1 = ((hw_rate >> 32) & 0x00000000ffffffff);
2036 		log.u_bbr.flex2 = (hw_rate & 0x00000000ffffffff);
2037 		if (rack->r_ctl.crte) {
2038 			ifp = rack->r_ctl.crte->ptbl->rs_ifp;
2039 		} else if (rack->rc_inp->inp_route.ro_nh &&
2040 			   rack->rc_inp->inp_route.ro_nh->nh_ifp) {
2041 			ifp = rack->rc_inp->inp_route.ro_nh->nh_ifp;
2042 		} else
2043 			ifp = NULL;
2044 		if (ifp) {
2045 			log.u_bbr.flex3 = (((uint64_t)ifp  >> 32) & 0x00000000ffffffff);
2046 			log.u_bbr.flex4 = ((uint64_t)ifp & 0x00000000ffffffff);
2047 		}
2048 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
2049 		log.u_bbr.bw_inuse = rate;
2050 		log.u_bbr.flex5 = line;
2051 		log.u_bbr.flex6 = error;
2052 		log.u_bbr.flex7 = mod;
2053 		log.u_bbr.applimited = rack->r_ctl.rc_pace_max_segs;
2054 		log.u_bbr.flex8 = rack->use_fixed_rate;
2055 		log.u_bbr.flex8 <<= 1;
2056 		log.u_bbr.flex8 |= rack->rack_hdrw_pacing;
2057 		log.u_bbr.pkts_out = rack->rc_tp->t_maxseg;
2058 		log.u_bbr.delRate = rack->r_ctl.crte_prev_rate;
2059 		if (rack->r_ctl.crte)
2060 			log.u_bbr.cur_del_rate = rack->r_ctl.crte->rate;
2061 		else
2062 			log.u_bbr.cur_del_rate = 0;
2063 		log.u_bbr.rttProp = rack->r_ctl.last_hw_bw_req;
2064 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
2065 		    &rack->rc_inp->inp_socket->so_rcv,
2066 		    &rack->rc_inp->inp_socket->so_snd,
2067 		    BBR_LOG_HDWR_PACE, 0,
2068 		    0, &log, false, &tv);
2069 	}
2070 }
2071 
2072 static uint64_t
2073 rack_get_output_bw(struct tcp_rack *rack, uint64_t bw, struct rack_sendmap *rsm, int *capped)
2074 {
2075 	/*
2076 	 * We allow rack_per_of_gp_xx to dictate our bw rate we want.
2077 	 */
2078 	uint64_t bw_est, high_rate;
2079 	uint64_t gain;
2080 
2081 	gain = (uint64_t)rack_get_output_gain(rack, rsm);
2082 	bw_est = bw * gain;
2083 	bw_est /= (uint64_t)100;
2084 	/* Never fall below the minimum (def 64kbps) */
2085 	if (bw_est < RACK_MIN_BW)
2086 		bw_est = RACK_MIN_BW;
2087 	if (rack->r_rack_hw_rate_caps) {
2088 		/* Rate caps are in place */
2089 		if (rack->r_ctl.crte != NULL) {
2090 			/* We have a hdwr rate already */
2091 			high_rate = tcp_hw_highest_rate(rack->r_ctl.crte);
2092 			if (bw_est >= high_rate) {
2093 				/* We are capping bw at the highest rate table entry */
2094 				rack_log_hdwr_pacing(rack,
2095 						     bw_est, high_rate, __LINE__,
2096 						     0, 3);
2097 				bw_est = high_rate;
2098 				if (capped)
2099 					*capped = 1;
2100 			}
2101 		} else if ((rack->rack_hdrw_pacing == 0) &&
2102 			   (rack->rack_hdw_pace_ena) &&
2103 			   (rack->rack_attempt_hdwr_pace == 0) &&
2104 			   (rack->rc_inp->inp_route.ro_nh != NULL) &&
2105 			   (rack->rc_inp->inp_route.ro_nh->nh_ifp != NULL)) {
2106 			/*
2107 			 * Special case, we have not yet attempted hardware
2108 			 * pacing, and yet we may, when we do, find out if we are
2109 			 * above the highest rate. We need to know the maxbw for the interface
2110 			 * in question (if it supports ratelimiting). We get back
2111 			 * a 0, if the interface is not found in the RL lists.
2112 			 */
2113 			high_rate = tcp_hw_highest_rate_ifp(rack->rc_inp->inp_route.ro_nh->nh_ifp, rack->rc_inp);
2114 			if (high_rate) {
2115 				/* Yep, we have a rate is it above this rate? */
2116 				if (bw_est > high_rate) {
2117 					bw_est = high_rate;
2118 					if (capped)
2119 						*capped = 1;
2120 				}
2121 			}
2122 		}
2123 	}
2124 	return (bw_est);
2125 }
2126 
2127 static void
2128 rack_log_retran_reason(struct tcp_rack *rack, struct rack_sendmap *rsm, uint32_t tsused, uint32_t thresh, int mod)
2129 {
2130 	if (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
2131 		union tcp_log_stackspecific log;
2132 		struct timeval tv;
2133 
2134 		if ((mod != 1) && (rack_verbose_logging == 0)) {
2135 			/*
2136 			 * We get 3 values currently for mod
2137 			 * 1 - We are retransmitting and this tells the reason.
2138 			 * 2 - We are clearing a dup-ack count.
2139 			 * 3 - We are incrementing a dup-ack count.
2140 			 *
2141 			 * The clear/increment are only logged
2142 			 * if you have BBverbose on.
2143 			 */
2144 			return;
2145 		}
2146 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
2147 		log.u_bbr.flex1 = tsused;
2148 		log.u_bbr.flex2 = thresh;
2149 		log.u_bbr.flex3 = rsm->r_flags;
2150 		log.u_bbr.flex4 = rsm->r_dupack;
2151 		log.u_bbr.flex5 = rsm->r_start;
2152 		log.u_bbr.flex6 = rsm->r_end;
2153 		log.u_bbr.flex8 = mod;
2154 		log.u_bbr.inhpts = tcp_in_hpts(rack->rc_inp);
2155 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
2156 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
2157 		log.u_bbr.pkts_out = rack->r_ctl.rc_out_at_rto;
2158 		log.u_bbr.delivered = rack->r_ctl.rc_snd_max_at_rto;
2159 		log.u_bbr.pacing_gain = rack->r_must_retran;
2160 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
2161 		    &rack->rc_inp->inp_socket->so_rcv,
2162 		    &rack->rc_inp->inp_socket->so_snd,
2163 		    BBR_LOG_SETTINGS_CHG, 0,
2164 		    0, &log, false, &tv);
2165 	}
2166 }
2167 
2168 static void
2169 rack_log_to_start(struct tcp_rack *rack, uint32_t cts, uint32_t to, int32_t slot, uint8_t which)
2170 {
2171 	if (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
2172 		union tcp_log_stackspecific log;
2173 		struct timeval tv;
2174 
2175 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
2176 		log.u_bbr.flex1 = rack->rc_tp->t_srtt;
2177 		log.u_bbr.flex2 = to;
2178 		log.u_bbr.flex3 = rack->r_ctl.rc_hpts_flags;
2179 		log.u_bbr.flex4 = slot;
2180 		log.u_bbr.flex5 = rack->rc_inp->inp_hptsslot;
2181 		log.u_bbr.flex6 = rack->rc_tp->t_rxtcur;
2182 		log.u_bbr.flex7 = rack->rc_in_persist;
2183 		log.u_bbr.flex8 = which;
2184 		if (rack->rack_no_prr)
2185 			log.u_bbr.pkts_out = 0;
2186 		else
2187 			log.u_bbr.pkts_out = rack->r_ctl.rc_prr_sndcnt;
2188 		log.u_bbr.inhpts = tcp_in_hpts(rack->rc_inp);
2189 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
2190 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
2191 		log.u_bbr.pkts_out = rack->r_ctl.rc_out_at_rto;
2192 		log.u_bbr.delivered = rack->r_ctl.rc_snd_max_at_rto;
2193 		log.u_bbr.pacing_gain = rack->r_must_retran;
2194 		log.u_bbr.cwnd_gain = rack->rc_has_collapsed;
2195 		log.u_bbr.lt_epoch = rack->rc_tp->t_rxtshift;
2196 		log.u_bbr.lost = rack_rto_min;
2197 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
2198 		    &rack->rc_inp->inp_socket->so_rcv,
2199 		    &rack->rc_inp->inp_socket->so_snd,
2200 		    BBR_LOG_TIMERSTAR, 0,
2201 		    0, &log, false, &tv);
2202 	}
2203 }
2204 
2205 static void
2206 rack_log_to_event(struct tcp_rack *rack, int32_t to_num, struct rack_sendmap *rsm)
2207 {
2208 	if (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
2209 		union tcp_log_stackspecific log;
2210 		struct timeval tv;
2211 
2212 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
2213 		log.u_bbr.inhpts = tcp_in_hpts(rack->rc_inp);
2214 		log.u_bbr.flex8 = to_num;
2215 		log.u_bbr.flex1 = rack->r_ctl.rc_rack_min_rtt;
2216 		log.u_bbr.flex2 = rack->rc_rack_rtt;
2217 		if (rsm == NULL)
2218 			log.u_bbr.flex3 = 0;
2219 		else
2220 			log.u_bbr.flex3 = rsm->r_end - rsm->r_start;
2221 		if (rack->rack_no_prr)
2222 			log.u_bbr.flex5 = 0;
2223 		else
2224 			log.u_bbr.flex5 = rack->r_ctl.rc_prr_sndcnt;
2225 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
2226 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
2227 		log.u_bbr.pkts_out = rack->r_ctl.rc_out_at_rto;
2228 		log.u_bbr.delivered = rack->r_ctl.rc_snd_max_at_rto;
2229 		log.u_bbr.pacing_gain = rack->r_must_retran;
2230 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
2231 		    &rack->rc_inp->inp_socket->so_rcv,
2232 		    &rack->rc_inp->inp_socket->so_snd,
2233 		    BBR_LOG_RTO, 0,
2234 		    0, &log, false, &tv);
2235 	}
2236 }
2237 
2238 static void
2239 rack_log_map_chg(struct tcpcb *tp, struct tcp_rack *rack,
2240 		 struct rack_sendmap *prev,
2241 		 struct rack_sendmap *rsm,
2242 		 struct rack_sendmap *next,
2243 		 int flag, uint32_t th_ack, int line)
2244 {
2245 	if (rack_verbose_logging && (tp->t_logstate != TCP_LOG_STATE_OFF)) {
2246 		union tcp_log_stackspecific log;
2247 		struct timeval tv;
2248 
2249 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
2250 		log.u_bbr.flex8 = flag;
2251 		log.u_bbr.inhpts = tcp_in_hpts(rack->rc_inp);
2252 		log.u_bbr.cur_del_rate = (uint64_t)prev;
2253 		log.u_bbr.delRate = (uint64_t)rsm;
2254 		log.u_bbr.rttProp = (uint64_t)next;
2255 		log.u_bbr.flex7 = 0;
2256 		if (prev) {
2257 			log.u_bbr.flex1 = prev->r_start;
2258 			log.u_bbr.flex2 = prev->r_end;
2259 			log.u_bbr.flex7 |= 0x4;
2260 		}
2261 		if (rsm) {
2262 			log.u_bbr.flex3 = rsm->r_start;
2263 			log.u_bbr.flex4 = rsm->r_end;
2264 			log.u_bbr.flex7 |= 0x2;
2265 		}
2266 		if (next) {
2267 			log.u_bbr.flex5 = next->r_start;
2268 			log.u_bbr.flex6 = next->r_end;
2269 			log.u_bbr.flex7 |= 0x1;
2270 		}
2271 		log.u_bbr.applimited = line;
2272 		log.u_bbr.pkts_out = th_ack;
2273 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
2274 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
2275 		if (rack->rack_no_prr)
2276 			log.u_bbr.lost = 0;
2277 		else
2278 			log.u_bbr.lost = rack->r_ctl.rc_prr_sndcnt;
2279 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
2280 		    &rack->rc_inp->inp_socket->so_rcv,
2281 		    &rack->rc_inp->inp_socket->so_snd,
2282 		    TCP_LOG_MAPCHG, 0,
2283 		    0, &log, false, &tv);
2284 	}
2285 }
2286 
2287 static void
2288 rack_log_rtt_upd(struct tcpcb *tp, struct tcp_rack *rack, uint32_t t, uint32_t len,
2289 		 struct rack_sendmap *rsm, int conf)
2290 {
2291 	if (tp->t_logstate != TCP_LOG_STATE_OFF) {
2292 		union tcp_log_stackspecific log;
2293 		struct timeval tv;
2294 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
2295 		log.u_bbr.inhpts = tcp_in_hpts(rack->rc_inp);
2296 		log.u_bbr.flex1 = t;
2297 		log.u_bbr.flex2 = len;
2298 		log.u_bbr.flex3 = rack->r_ctl.rc_rack_min_rtt;
2299 		log.u_bbr.flex4 = rack->r_ctl.rack_rs.rs_rtt_lowest;
2300 		log.u_bbr.flex5 = rack->r_ctl.rack_rs.rs_rtt_highest;
2301 		log.u_bbr.flex6 = rack->r_ctl.rack_rs.rs_us_rtrcnt;
2302 		log.u_bbr.flex7 = conf;
2303 		log.u_bbr.rttProp = (uint64_t)rack->r_ctl.rack_rs.rs_rtt_tot;
2304 		log.u_bbr.flex8 = rack->r_ctl.rc_rate_sample_method;
2305 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
2306 		log.u_bbr.delivered = rack->r_ctl.rack_rs.rs_us_rtrcnt;
2307 		log.u_bbr.pkts_out = rack->r_ctl.rack_rs.rs_flags;
2308 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
2309 		if (rsm) {
2310 			log.u_bbr.pkt_epoch = rsm->r_start;
2311 			log.u_bbr.lost = rsm->r_end;
2312 			log.u_bbr.cwnd_gain = rsm->r_rtr_cnt;
2313 			/* We loose any upper of the 24 bits */
2314 			log.u_bbr.pacing_gain = (uint16_t)rsm->r_flags;
2315 		} else {
2316 			/* Its a SYN */
2317 			log.u_bbr.pkt_epoch = rack->rc_tp->iss;
2318 			log.u_bbr.lost = 0;
2319 			log.u_bbr.cwnd_gain = 0;
2320 			log.u_bbr.pacing_gain = 0;
2321 		}
2322 		/* Write out general bits of interest rrs here */
2323 		log.u_bbr.use_lt_bw = rack->rc_highly_buffered;
2324 		log.u_bbr.use_lt_bw <<= 1;
2325 		log.u_bbr.use_lt_bw |= rack->forced_ack;
2326 		log.u_bbr.use_lt_bw <<= 1;
2327 		log.u_bbr.use_lt_bw |= rack->rc_gp_dyn_mul;
2328 		log.u_bbr.use_lt_bw <<= 1;
2329 		log.u_bbr.use_lt_bw |= rack->in_probe_rtt;
2330 		log.u_bbr.use_lt_bw <<= 1;
2331 		log.u_bbr.use_lt_bw |= rack->measure_saw_probe_rtt;
2332 		log.u_bbr.use_lt_bw <<= 1;
2333 		log.u_bbr.use_lt_bw |= rack->app_limited_needs_set;
2334 		log.u_bbr.use_lt_bw <<= 1;
2335 		log.u_bbr.use_lt_bw |= rack->rc_gp_filled;
2336 		log.u_bbr.use_lt_bw <<= 1;
2337 		log.u_bbr.use_lt_bw |= rack->rc_dragged_bottom;
2338 		log.u_bbr.applimited = rack->r_ctl.rc_target_probertt_flight;
2339 		log.u_bbr.epoch = rack->r_ctl.rc_time_probertt_starts;
2340 		log.u_bbr.lt_epoch = rack->r_ctl.rc_time_probertt_entered;
2341 		log.u_bbr.cur_del_rate = rack->r_ctl.rc_lower_rtt_us_cts;
2342 		log.u_bbr.delRate = rack->r_ctl.rc_gp_srtt;
2343 		log.u_bbr.bw_inuse = tcp_tv_to_usectick(&rack->r_ctl.act_rcv_time);
2344 		log.u_bbr.bw_inuse <<= 32;
2345 		if (rsm)
2346 			log.u_bbr.bw_inuse |= ((uint32_t)rsm->r_tim_lastsent[(rsm->r_rtr_cnt-1)]);
2347 		TCP_LOG_EVENTP(tp, NULL,
2348 		    &rack->rc_inp->inp_socket->so_rcv,
2349 		    &rack->rc_inp->inp_socket->so_snd,
2350 		    BBR_LOG_BBRRTT, 0,
2351 		    0, &log, false, &tv);
2352 
2353 
2354 	}
2355 }
2356 
2357 static void
2358 rack_log_rtt_sample(struct tcp_rack *rack, uint32_t rtt)
2359 {
2360 	/*
2361 	 * Log the rtt sample we are
2362 	 * applying to the srtt algorithm in
2363 	 * useconds.
2364 	 */
2365 	if (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
2366 		union tcp_log_stackspecific log;
2367 		struct timeval tv;
2368 
2369 		/* Convert our ms to a microsecond */
2370 		memset(&log, 0, sizeof(log));
2371 		log.u_bbr.flex1 = rtt;
2372 		log.u_bbr.flex2 = rack->r_ctl.ack_count;
2373 		log.u_bbr.flex3 = rack->r_ctl.sack_count;
2374 		log.u_bbr.flex4 = rack->r_ctl.sack_noextra_move;
2375 		log.u_bbr.flex5 = rack->r_ctl.sack_moved_extra;
2376 		log.u_bbr.flex6 = rack->rc_tp->t_rxtcur;
2377 		log.u_bbr.flex7 = 1;
2378 		log.u_bbr.flex8 = rack->sack_attack_disable;
2379 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
2380 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
2381 		log.u_bbr.pkts_out = rack->r_ctl.rc_out_at_rto;
2382 		log.u_bbr.delivered = rack->r_ctl.rc_snd_max_at_rto;
2383 		log.u_bbr.pacing_gain = rack->r_must_retran;
2384 		/*
2385 		 * We capture in delRate the upper 32 bits as
2386 		 * the confidence level we had declared, and the
2387 		 * lower 32 bits as the actual RTT using the arrival
2388 		 * timestamp.
2389 		 */
2390 		log.u_bbr.delRate = rack->r_ctl.rack_rs.confidence;
2391 		log.u_bbr.delRate <<= 32;
2392 		log.u_bbr.delRate |= rack->r_ctl.rack_rs.rs_us_rtt;
2393 		/* Lets capture all the things that make up t_rtxcur */
2394 		log.u_bbr.applimited = rack_rto_min;
2395 		log.u_bbr.epoch = rack_rto_max;
2396 		log.u_bbr.lt_epoch = rack->r_ctl.timer_slop;
2397 		log.u_bbr.lost = rack_rto_min;
2398 		log.u_bbr.pkt_epoch = TICKS_2_USEC(tcp_rexmit_slop);
2399 		log.u_bbr.rttProp = RACK_REXMTVAL(rack->rc_tp);
2400 		log.u_bbr.bw_inuse = rack->r_ctl.act_rcv_time.tv_sec;
2401 		log.u_bbr.bw_inuse *= HPTS_USEC_IN_SEC;
2402 		log.u_bbr.bw_inuse += rack->r_ctl.act_rcv_time.tv_usec;
2403 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
2404 		    &rack->rc_inp->inp_socket->so_rcv,
2405 		    &rack->rc_inp->inp_socket->so_snd,
2406 		    TCP_LOG_RTT, 0,
2407 		    0, &log, false, &tv);
2408 	}
2409 }
2410 
2411 static void
2412 rack_log_rtt_sample_calc(struct tcp_rack *rack, uint32_t rtt, uint32_t send_time, uint32_t ack_time, int where)
2413 {
2414 	if (rack_verbose_logging && (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF)) {
2415 		union tcp_log_stackspecific log;
2416 		struct timeval tv;
2417 
2418 		/* Convert our ms to a microsecond */
2419 		memset(&log, 0, sizeof(log));
2420 		log.u_bbr.flex1 = rtt;
2421 		log.u_bbr.flex2 = send_time;
2422 		log.u_bbr.flex3 = ack_time;
2423 		log.u_bbr.flex4 = where;
2424 		log.u_bbr.flex7 = 2;
2425 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
2426 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
2427 		    &rack->rc_inp->inp_socket->so_rcv,
2428 		    &rack->rc_inp->inp_socket->so_snd,
2429 		    TCP_LOG_RTT, 0,
2430 		    0, &log, false, &tv);
2431 	}
2432 }
2433 
2434 
2435 
2436 static inline void
2437 rack_log_progress_event(struct tcp_rack *rack, struct tcpcb *tp, uint32_t tick,  int event, int line)
2438 {
2439 	if (rack_verbose_logging && (tp->t_logstate != TCP_LOG_STATE_OFF)) {
2440 		union tcp_log_stackspecific log;
2441 		struct timeval tv;
2442 
2443 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
2444 		log.u_bbr.inhpts = tcp_in_hpts(rack->rc_inp);
2445 		log.u_bbr.flex1 = line;
2446 		log.u_bbr.flex2 = tick;
2447 		log.u_bbr.flex3 = tp->t_maxunacktime;
2448 		log.u_bbr.flex4 = tp->t_acktime;
2449 		log.u_bbr.flex8 = event;
2450 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
2451 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
2452 		log.u_bbr.pkts_out = rack->r_ctl.rc_out_at_rto;
2453 		log.u_bbr.delivered = rack->r_ctl.rc_snd_max_at_rto;
2454 		log.u_bbr.pacing_gain = rack->r_must_retran;
2455 		TCP_LOG_EVENTP(tp, NULL,
2456 		    &rack->rc_inp->inp_socket->so_rcv,
2457 		    &rack->rc_inp->inp_socket->so_snd,
2458 		    BBR_LOG_PROGRESS, 0,
2459 		    0, &log, false, &tv);
2460 	}
2461 }
2462 
2463 static void
2464 rack_log_type_bbrsnd(struct tcp_rack *rack, uint32_t len, uint32_t slot, uint32_t cts, struct timeval *tv)
2465 {
2466 	if (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
2467 		union tcp_log_stackspecific log;
2468 
2469 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
2470 		log.u_bbr.inhpts = tcp_in_hpts(rack->rc_inp);
2471 		log.u_bbr.flex1 = slot;
2472 		if (rack->rack_no_prr)
2473 			log.u_bbr.flex2 = 0;
2474 		else
2475 			log.u_bbr.flex2 = rack->r_ctl.rc_prr_sndcnt;
2476 		log.u_bbr.flex7 = (0x0000ffff & rack->r_ctl.rc_hpts_flags);
2477 		log.u_bbr.flex8 = rack->rc_in_persist;
2478 		log.u_bbr.timeStamp = cts;
2479 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
2480 		log.u_bbr.pkts_out = rack->r_ctl.rc_out_at_rto;
2481 		log.u_bbr.delivered = rack->r_ctl.rc_snd_max_at_rto;
2482 		log.u_bbr.pacing_gain = rack->r_must_retran;
2483 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
2484 		    &rack->rc_inp->inp_socket->so_rcv,
2485 		    &rack->rc_inp->inp_socket->so_snd,
2486 		    BBR_LOG_BBRSND, 0,
2487 		    0, &log, false, tv);
2488 	}
2489 }
2490 
2491 static void
2492 rack_log_doseg_done(struct tcp_rack *rack, uint32_t cts, int32_t nxt_pkt, int32_t did_out, int way_out, int nsegs)
2493 {
2494 	if (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
2495 		union tcp_log_stackspecific log;
2496 		struct timeval tv;
2497 
2498 		memset(&log, 0, sizeof(log));
2499 		log.u_bbr.flex1 = did_out;
2500 		log.u_bbr.flex2 = nxt_pkt;
2501 		log.u_bbr.flex3 = way_out;
2502 		log.u_bbr.flex4 = rack->r_ctl.rc_hpts_flags;
2503 		if (rack->rack_no_prr)
2504 			log.u_bbr.flex5 = 0;
2505 		else
2506 			log.u_bbr.flex5 = rack->r_ctl.rc_prr_sndcnt;
2507 		log.u_bbr.flex6 = nsegs;
2508 		log.u_bbr.applimited = rack->r_ctl.rc_pace_min_segs;
2509 		log.u_bbr.flex7 = rack->rc_ack_can_sendout_data;	/* Do we have ack-can-send set */
2510 		log.u_bbr.flex7 <<= 1;
2511 		log.u_bbr.flex7 |= rack->r_fast_output;	/* is fast output primed */
2512 		log.u_bbr.flex7 <<= 1;
2513 		log.u_bbr.flex7 |= rack->r_wanted_output;	/* Do we want output */
2514 		log.u_bbr.flex8 = rack->rc_in_persist;
2515 		log.u_bbr.inhpts = tcp_in_hpts(rack->rc_inp);
2516 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
2517 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
2518 		log.u_bbr.use_lt_bw = rack->r_ent_rec_ns;
2519 		log.u_bbr.use_lt_bw <<= 1;
2520 		log.u_bbr.use_lt_bw |= rack->r_might_revert;
2521 		log.u_bbr.pkts_out = rack->r_ctl.rc_out_at_rto;
2522 		log.u_bbr.delivered = rack->r_ctl.rc_snd_max_at_rto;
2523 		log.u_bbr.pacing_gain = rack->r_must_retran;
2524 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
2525 		    &rack->rc_inp->inp_socket->so_rcv,
2526 		    &rack->rc_inp->inp_socket->so_snd,
2527 		    BBR_LOG_DOSEG_DONE, 0,
2528 		    0, &log, false, &tv);
2529 	}
2530 }
2531 
2532 static void
2533 rack_log_type_pacing_sizes(struct tcpcb *tp, struct tcp_rack *rack, uint32_t arg1, uint32_t arg2, uint32_t arg3, uint8_t frm)
2534 {
2535 	if (tp->t_logstate != TCP_LOG_STATE_OFF) {
2536 		union tcp_log_stackspecific log;
2537 		struct timeval tv;
2538 
2539 		memset(&log, 0, sizeof(log));
2540 		log.u_bbr.flex1 = rack->r_ctl.rc_pace_min_segs;
2541 		log.u_bbr.flex3 = rack->r_ctl.rc_pace_max_segs;
2542 		log.u_bbr.flex4 = arg1;
2543 		log.u_bbr.flex5 = arg2;
2544 		log.u_bbr.flex6 = arg3;
2545 		log.u_bbr.flex8 = frm;
2546 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
2547 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
2548 		log.u_bbr.pkts_out = rack->r_ctl.rc_out_at_rto;
2549 		log.u_bbr.applimited = rack->r_ctl.rc_sacked;
2550 		log.u_bbr.delivered = rack->r_ctl.rc_snd_max_at_rto;
2551 		log.u_bbr.pacing_gain = rack->r_must_retran;
2552 		TCP_LOG_EVENTP(tp, NULL,
2553 		    &tp->t_inpcb->inp_socket->so_rcv,
2554 		    &tp->t_inpcb->inp_socket->so_snd,
2555 		    TCP_HDWR_PACE_SIZE, 0,
2556 		    0, &log, false, &tv);
2557 	}
2558 }
2559 
2560 static void
2561 rack_log_type_just_return(struct tcp_rack *rack, uint32_t cts, uint32_t tlen, uint32_t slot,
2562 			  uint8_t hpts_calling, int reason, uint32_t cwnd_to_use)
2563 {
2564 	if (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
2565 		union tcp_log_stackspecific log;
2566 		struct timeval tv;
2567 
2568 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
2569 		log.u_bbr.inhpts = tcp_in_hpts(rack->rc_inp);
2570 		log.u_bbr.flex1 = slot;
2571 		log.u_bbr.flex2 = rack->r_ctl.rc_hpts_flags;
2572 		log.u_bbr.flex4 = reason;
2573 		if (rack->rack_no_prr)
2574 			log.u_bbr.flex5 = 0;
2575 		else
2576 			log.u_bbr.flex5 = rack->r_ctl.rc_prr_sndcnt;
2577 		log.u_bbr.flex7 = hpts_calling;
2578 		log.u_bbr.flex8 = rack->rc_in_persist;
2579 		log.u_bbr.lt_epoch = cwnd_to_use;
2580 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
2581 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
2582 		log.u_bbr.pkts_out = rack->r_ctl.rc_out_at_rto;
2583 		log.u_bbr.delivered = rack->r_ctl.rc_snd_max_at_rto;
2584 		log.u_bbr.pacing_gain = rack->r_must_retran;
2585 		log.u_bbr.cwnd_gain = rack->rc_has_collapsed;
2586 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
2587 		    &rack->rc_inp->inp_socket->so_rcv,
2588 		    &rack->rc_inp->inp_socket->so_snd,
2589 		    BBR_LOG_JUSTRET, 0,
2590 		    tlen, &log, false, &tv);
2591 	}
2592 }
2593 
2594 static void
2595 rack_log_to_cancel(struct tcp_rack *rack, int32_t hpts_removed, int line, uint32_t us_cts,
2596 		   struct timeval *tv, uint32_t flags_on_entry)
2597 {
2598 	if (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
2599 		union tcp_log_stackspecific log;
2600 
2601 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
2602 		log.u_bbr.inhpts = tcp_in_hpts(rack->rc_inp);
2603 		log.u_bbr.flex1 = line;
2604 		log.u_bbr.flex2 = rack->r_ctl.rc_last_output_to;
2605 		log.u_bbr.flex3 = flags_on_entry;
2606 		log.u_bbr.flex4 = us_cts;
2607 		if (rack->rack_no_prr)
2608 			log.u_bbr.flex5 = 0;
2609 		else
2610 			log.u_bbr.flex5 = rack->r_ctl.rc_prr_sndcnt;
2611 		log.u_bbr.flex6 = rack->rc_tp->t_rxtcur;
2612 		log.u_bbr.flex7 = hpts_removed;
2613 		log.u_bbr.flex8 = 1;
2614 		log.u_bbr.applimited = rack->r_ctl.rc_hpts_flags;
2615 		log.u_bbr.timeStamp = us_cts;
2616 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
2617 		log.u_bbr.pkts_out = rack->r_ctl.rc_out_at_rto;
2618 		log.u_bbr.delivered = rack->r_ctl.rc_snd_max_at_rto;
2619 		log.u_bbr.pacing_gain = rack->r_must_retran;
2620 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
2621 		    &rack->rc_inp->inp_socket->so_rcv,
2622 		    &rack->rc_inp->inp_socket->so_snd,
2623 		    BBR_LOG_TIMERCANC, 0,
2624 		    0, &log, false, tv);
2625 	}
2626 }
2627 
2628 static void
2629 rack_log_alt_to_to_cancel(struct tcp_rack *rack,
2630 			  uint32_t flex1, uint32_t flex2,
2631 			  uint32_t flex3, uint32_t flex4,
2632 			  uint32_t flex5, uint32_t flex6,
2633 			  uint16_t flex7, uint8_t mod)
2634 {
2635 	if (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
2636 		union tcp_log_stackspecific log;
2637 		struct timeval tv;
2638 
2639 		if (mod == 1) {
2640 			/* No you can't use 1, its for the real to cancel */
2641 			return;
2642 		}
2643 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
2644 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
2645 		log.u_bbr.flex1 = flex1;
2646 		log.u_bbr.flex2 = flex2;
2647 		log.u_bbr.flex3 = flex3;
2648 		log.u_bbr.flex4 = flex4;
2649 		log.u_bbr.flex5 = flex5;
2650 		log.u_bbr.flex6 = flex6;
2651 		log.u_bbr.flex7 = flex7;
2652 		log.u_bbr.flex8 = mod;
2653 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
2654 		    &rack->rc_inp->inp_socket->so_rcv,
2655 		    &rack->rc_inp->inp_socket->so_snd,
2656 		    BBR_LOG_TIMERCANC, 0,
2657 		    0, &log, false, &tv);
2658 	}
2659 }
2660 
2661 static void
2662 rack_log_to_processing(struct tcp_rack *rack, uint32_t cts, int32_t ret, int32_t timers)
2663 {
2664 	if (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
2665 		union tcp_log_stackspecific log;
2666 		struct timeval tv;
2667 
2668 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
2669 		log.u_bbr.flex1 = timers;
2670 		log.u_bbr.flex2 = ret;
2671 		log.u_bbr.flex3 = rack->r_ctl.rc_timer_exp;
2672 		log.u_bbr.flex4 = rack->r_ctl.rc_hpts_flags;
2673 		log.u_bbr.flex5 = cts;
2674 		if (rack->rack_no_prr)
2675 			log.u_bbr.flex6 = 0;
2676 		else
2677 			log.u_bbr.flex6 = rack->r_ctl.rc_prr_sndcnt;
2678 		log.u_bbr.pkts_out = rack->r_ctl.rc_out_at_rto;
2679 		log.u_bbr.delivered = rack->r_ctl.rc_snd_max_at_rto;
2680 		log.u_bbr.pacing_gain = rack->r_must_retran;
2681 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
2682 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
2683 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
2684 		    &rack->rc_inp->inp_socket->so_rcv,
2685 		    &rack->rc_inp->inp_socket->so_snd,
2686 		    BBR_LOG_TO_PROCESS, 0,
2687 		    0, &log, false, &tv);
2688 	}
2689 }
2690 
2691 static void
2692 rack_log_to_prr(struct tcp_rack *rack, int frm, int orig_cwnd, int line)
2693 {
2694 	if (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
2695 		union tcp_log_stackspecific log;
2696 		struct timeval tv;
2697 
2698 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
2699 		log.u_bbr.flex1 = rack->r_ctl.rc_prr_out;
2700 		log.u_bbr.flex2 = rack->r_ctl.rc_prr_recovery_fs;
2701 		if (rack->rack_no_prr)
2702 			log.u_bbr.flex3 = 0;
2703 		else
2704 			log.u_bbr.flex3 = rack->r_ctl.rc_prr_sndcnt;
2705 		log.u_bbr.flex4 = rack->r_ctl.rc_prr_delivered;
2706 		log.u_bbr.flex5 = rack->r_ctl.rc_sacked;
2707 		log.u_bbr.flex6 = rack->r_ctl.rc_holes_rxt;
2708 		log.u_bbr.flex7 = line;
2709 		log.u_bbr.flex8 = frm;
2710 		log.u_bbr.pkts_out = orig_cwnd;
2711 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
2712 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
2713 		log.u_bbr.use_lt_bw = rack->r_ent_rec_ns;
2714 		log.u_bbr.use_lt_bw <<= 1;
2715 		log.u_bbr.use_lt_bw |= rack->r_might_revert;
2716 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
2717 		    &rack->rc_inp->inp_socket->so_rcv,
2718 		    &rack->rc_inp->inp_socket->so_snd,
2719 		    BBR_LOG_BBRUPD, 0,
2720 		    0, &log, false, &tv);
2721 	}
2722 }
2723 
2724 #ifdef NETFLIX_EXP_DETECTION
2725 static void
2726 rack_log_sad(struct tcp_rack *rack, int event)
2727 {
2728 	if (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
2729 		union tcp_log_stackspecific log;
2730 		struct timeval tv;
2731 
2732 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
2733 		log.u_bbr.flex1 = rack->r_ctl.sack_count;
2734 		log.u_bbr.flex2 = rack->r_ctl.ack_count;
2735 		log.u_bbr.flex3 = rack->r_ctl.sack_moved_extra;
2736 		log.u_bbr.flex4 = rack->r_ctl.sack_noextra_move;
2737 		log.u_bbr.flex5 = rack->r_ctl.rc_num_maps_alloced;
2738 		log.u_bbr.flex6 = tcp_sack_to_ack_thresh;
2739 		log.u_bbr.pkts_out = tcp_sack_to_move_thresh;
2740 		log.u_bbr.lt_epoch = (tcp_force_detection << 8);
2741 		log.u_bbr.lt_epoch |= rack->do_detection;
2742 		log.u_bbr.applimited = tcp_map_minimum;
2743 		log.u_bbr.flex7 = rack->sack_attack_disable;
2744 		log.u_bbr.flex8 = event;
2745 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
2746 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
2747 		log.u_bbr.delivered = tcp_sad_decay_val;
2748 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
2749 		    &rack->rc_inp->inp_socket->so_rcv,
2750 		    &rack->rc_inp->inp_socket->so_snd,
2751 		    TCP_SAD_DETECTION, 0,
2752 		    0, &log, false, &tv);
2753 	}
2754 }
2755 #endif
2756 
2757 static void
2758 rack_counter_destroy(void)
2759 {
2760 	counter_u64_free(rack_fto_send);
2761 	counter_u64_free(rack_fto_rsm_send);
2762 	counter_u64_free(rack_nfto_resend);
2763 	counter_u64_free(rack_hw_pace_init_fail);
2764 	counter_u64_free(rack_hw_pace_lost);
2765 	counter_u64_free(rack_non_fto_send);
2766 	counter_u64_free(rack_extended_rfo);
2767 	counter_u64_free(rack_ack_total);
2768 	counter_u64_free(rack_express_sack);
2769 	counter_u64_free(rack_sack_total);
2770 	counter_u64_free(rack_move_none);
2771 	counter_u64_free(rack_move_some);
2772 	counter_u64_free(rack_sack_attacks_detected);
2773 	counter_u64_free(rack_sack_attacks_reversed);
2774 	counter_u64_free(rack_sack_used_next_merge);
2775 	counter_u64_free(rack_sack_used_prev_merge);
2776 	counter_u64_free(rack_tlp_tot);
2777 	counter_u64_free(rack_tlp_newdata);
2778 	counter_u64_free(rack_tlp_retran);
2779 	counter_u64_free(rack_tlp_retran_bytes);
2780 	counter_u64_free(rack_to_tot);
2781 	counter_u64_free(rack_saw_enobuf);
2782 	counter_u64_free(rack_saw_enobuf_hw);
2783 	counter_u64_free(rack_saw_enetunreach);
2784 	counter_u64_free(rack_hot_alloc);
2785 	counter_u64_free(rack_to_alloc);
2786 	counter_u64_free(rack_to_alloc_hard);
2787 	counter_u64_free(rack_to_alloc_emerg);
2788 	counter_u64_free(rack_to_alloc_limited);
2789 	counter_u64_free(rack_alloc_limited_conns);
2790 	counter_u64_free(rack_split_limited);
2791 	counter_u64_free(rack_multi_single_eq);
2792 	counter_u64_free(rack_proc_non_comp_ack);
2793 	counter_u64_free(rack_sack_proc_all);
2794 	counter_u64_free(rack_sack_proc_restart);
2795 	counter_u64_free(rack_sack_proc_short);
2796 	counter_u64_free(rack_sack_skipped_acked);
2797 	counter_u64_free(rack_sack_splits);
2798 	counter_u64_free(rack_input_idle_reduces);
2799 	counter_u64_free(rack_collapsed_win);
2800 	counter_u64_free(rack_collapsed_win_rxt);
2801 	counter_u64_free(rack_collapsed_win_rxt_bytes);
2802 	counter_u64_free(rack_collapsed_win_seen);
2803 	counter_u64_free(rack_try_scwnd);
2804 	counter_u64_free(rack_persists_sends);
2805 	counter_u64_free(rack_persists_acks);
2806 	counter_u64_free(rack_persists_loss);
2807 	counter_u64_free(rack_persists_lost_ends);
2808 #ifdef INVARIANTS
2809 	counter_u64_free(rack_adjust_map_bw);
2810 #endif
2811 	COUNTER_ARRAY_FREE(rack_out_size, TCP_MSS_ACCT_SIZE);
2812 	COUNTER_ARRAY_FREE(rack_opts_arry, RACK_OPTS_SIZE);
2813 }
2814 
2815 static struct rack_sendmap *
2816 rack_alloc(struct tcp_rack *rack)
2817 {
2818 	struct rack_sendmap *rsm;
2819 
2820 	/*
2821 	 * First get the top of the list it in
2822 	 * theory is the "hottest" rsm we have,
2823 	 * possibly just freed by ack processing.
2824 	 */
2825 	if (rack->rc_free_cnt > rack_free_cache) {
2826 		rsm = TAILQ_FIRST(&rack->r_ctl.rc_free);
2827 		TAILQ_REMOVE(&rack->r_ctl.rc_free, rsm, r_tnext);
2828 		counter_u64_add(rack_hot_alloc, 1);
2829 		rack->rc_free_cnt--;
2830 		return (rsm);
2831 	}
2832 	/*
2833 	 * Once we get under our free cache we probably
2834 	 * no longer have a "hot" one available. Lets
2835 	 * get one from UMA.
2836 	 */
2837 	rsm = uma_zalloc(rack_zone, M_NOWAIT);
2838 	if (rsm) {
2839 		rack->r_ctl.rc_num_maps_alloced++;
2840 		counter_u64_add(rack_to_alloc, 1);
2841 		return (rsm);
2842 	}
2843 	/*
2844 	 * Dig in to our aux rsm's (the last two) since
2845 	 * UMA failed to get us one.
2846 	 */
2847 	if (rack->rc_free_cnt) {
2848 		counter_u64_add(rack_to_alloc_emerg, 1);
2849 		rsm = TAILQ_FIRST(&rack->r_ctl.rc_free);
2850 		TAILQ_REMOVE(&rack->r_ctl.rc_free, rsm, r_tnext);
2851 		rack->rc_free_cnt--;
2852 		return (rsm);
2853 	}
2854 	return (NULL);
2855 }
2856 
2857 static struct rack_sendmap *
2858 rack_alloc_full_limit(struct tcp_rack *rack)
2859 {
2860 	if ((V_tcp_map_entries_limit > 0) &&
2861 	    (rack->do_detection == 0) &&
2862 	    (rack->r_ctl.rc_num_maps_alloced >= V_tcp_map_entries_limit)) {
2863 		counter_u64_add(rack_to_alloc_limited, 1);
2864 		if (!rack->alloc_limit_reported) {
2865 			rack->alloc_limit_reported = 1;
2866 			counter_u64_add(rack_alloc_limited_conns, 1);
2867 		}
2868 		return (NULL);
2869 	}
2870 	return (rack_alloc(rack));
2871 }
2872 
2873 /* wrapper to allocate a sendmap entry, subject to a specific limit */
2874 static struct rack_sendmap *
2875 rack_alloc_limit(struct tcp_rack *rack, uint8_t limit_type)
2876 {
2877 	struct rack_sendmap *rsm;
2878 
2879 	if (limit_type) {
2880 		/* currently there is only one limit type */
2881 		if (V_tcp_map_split_limit > 0 &&
2882 		    (rack->do_detection == 0) &&
2883 		    rack->r_ctl.rc_num_split_allocs >= V_tcp_map_split_limit) {
2884 			counter_u64_add(rack_split_limited, 1);
2885 			if (!rack->alloc_limit_reported) {
2886 				rack->alloc_limit_reported = 1;
2887 				counter_u64_add(rack_alloc_limited_conns, 1);
2888 			}
2889 			return (NULL);
2890 		}
2891 	}
2892 
2893 	/* allocate and mark in the limit type, if set */
2894 	rsm = rack_alloc(rack);
2895 	if (rsm != NULL && limit_type) {
2896 		rsm->r_limit_type = limit_type;
2897 		rack->r_ctl.rc_num_split_allocs++;
2898 	}
2899 	return (rsm);
2900 }
2901 
2902 static void
2903 rack_free(struct tcp_rack *rack, struct rack_sendmap *rsm)
2904 {
2905 	if (rsm->r_flags & RACK_APP_LIMITED) {
2906 		if (rack->r_ctl.rc_app_limited_cnt > 0) {
2907 			rack->r_ctl.rc_app_limited_cnt--;
2908 		}
2909 	}
2910 	if (rsm->r_limit_type) {
2911 		/* currently there is only one limit type */
2912 		rack->r_ctl.rc_num_split_allocs--;
2913 	}
2914 	if (rsm == rack->r_ctl.rc_first_appl) {
2915 		if (rack->r_ctl.rc_app_limited_cnt == 0)
2916 			rack->r_ctl.rc_first_appl = NULL;
2917 		else {
2918 			/* Follow the next one out */
2919 			struct rack_sendmap fe;
2920 
2921 			fe.r_start = rsm->r_nseq_appl;
2922 			rack->r_ctl.rc_first_appl = RB_FIND(rack_rb_tree_head, &rack->r_ctl.rc_mtree, &fe);
2923 		}
2924 	}
2925 	if (rsm == rack->r_ctl.rc_resend)
2926 		rack->r_ctl.rc_resend = NULL;
2927 	if (rsm == rack->r_ctl.rc_end_appl)
2928 		rack->r_ctl.rc_end_appl = NULL;
2929 	if (rack->r_ctl.rc_tlpsend == rsm)
2930 		rack->r_ctl.rc_tlpsend = NULL;
2931 	if (rack->r_ctl.rc_sacklast == rsm)
2932 		rack->r_ctl.rc_sacklast = NULL;
2933 	memset(rsm, 0, sizeof(struct rack_sendmap));
2934 	TAILQ_INSERT_HEAD(&rack->r_ctl.rc_free, rsm, r_tnext);
2935 	rack->rc_free_cnt++;
2936 }
2937 
2938 static void
2939 rack_free_trim(struct tcp_rack *rack)
2940 {
2941 	struct rack_sendmap *rsm;
2942 
2943 	/*
2944 	 * Free up all the tail entries until
2945 	 * we get our list down to the limit.
2946 	 */
2947 	while (rack->rc_free_cnt > rack_free_cache) {
2948 		rsm = TAILQ_LAST(&rack->r_ctl.rc_free, rack_head);
2949 		TAILQ_REMOVE(&rack->r_ctl.rc_free, rsm, r_tnext);
2950 		rack->rc_free_cnt--;
2951 		uma_zfree(rack_zone, rsm);
2952 	}
2953 }
2954 
2955 
2956 static uint32_t
2957 rack_get_measure_window(struct tcpcb *tp, struct tcp_rack *rack)
2958 {
2959 	uint64_t srtt, bw, len, tim;
2960 	uint32_t segsiz, def_len, minl;
2961 
2962 	segsiz = min(ctf_fixed_maxseg(tp), rack->r_ctl.rc_pace_min_segs);
2963 	def_len = rack_def_data_window * segsiz;
2964 	if (rack->rc_gp_filled == 0) {
2965 		/*
2966 		 * We have no measurement (IW is in flight?) so
2967 		 * we can only guess using our data_window sysctl
2968 		 * value (usually 20MSS).
2969 		 */
2970 		return (def_len);
2971 	}
2972 	/*
2973 	 * Now we have a number of factors to consider.
2974 	 *
2975 	 * 1) We have a desired BDP which is usually
2976 	 *    at least 2.
2977 	 * 2) We have a minimum number of rtt's usually 1 SRTT
2978 	 *    but we allow it too to be more.
2979 	 * 3) We want to make sure a measurement last N useconds (if
2980 	 *    we have set rack_min_measure_usec.
2981 	 *
2982 	 * We handle the first concern here by trying to create a data
2983 	 * window of max(rack_def_data_window, DesiredBDP). The
2984 	 * second concern we handle in not letting the measurement
2985 	 * window end normally until at least the required SRTT's
2986 	 * have gone by which is done further below in
2987 	 * rack_enough_for_measurement(). Finally the third concern
2988 	 * we also handle here by calculating how long that time
2989 	 * would take at the current BW and then return the
2990 	 * max of our first calculation and that length. Note
2991 	 * that if rack_min_measure_usec is 0, we don't deal
2992 	 * with concern 3. Also for both Concern 1 and 3 an
2993 	 * application limited period could end the measurement
2994 	 * earlier.
2995 	 *
2996 	 * So lets calculate the BDP with the "known" b/w using
2997 	 * the SRTT has our rtt and then multiply it by the
2998 	 * goal.
2999 	 */
3000 	bw = rack_get_bw(rack);
3001 	srtt = (uint64_t)tp->t_srtt;
3002 	len = bw * srtt;
3003 	len /= (uint64_t)HPTS_USEC_IN_SEC;
3004 	len *= max(1, rack_goal_bdp);
3005 	/* Now we need to round up to the nearest MSS */
3006 	len = roundup(len, segsiz);
3007 	if (rack_min_measure_usec) {
3008 		/* Now calculate our min length for this b/w */
3009 		tim = rack_min_measure_usec;
3010 		minl = (tim * bw) / (uint64_t)HPTS_USEC_IN_SEC;
3011 		if (minl == 0)
3012 			minl = 1;
3013 		minl = roundup(minl, segsiz);
3014 		if (len < minl)
3015 			len = minl;
3016 	}
3017 	/*
3018 	 * Now if we have a very small window we want
3019 	 * to attempt to get the window that is
3020 	 * as small as possible. This happens on
3021 	 * low b/w connections and we don't want to
3022 	 * span huge numbers of rtt's between measurements.
3023 	 *
3024 	 * We basically include 2 over our "MIN window" so
3025 	 * that the measurement can be shortened (possibly) by
3026 	 * an ack'ed packet.
3027 	 */
3028 	if (len < def_len)
3029 		return (max((uint32_t)len, ((MIN_GP_WIN+2) * segsiz)));
3030 	else
3031 		return (max((uint32_t)len, def_len));
3032 
3033 }
3034 
3035 static int
3036 rack_enough_for_measurement(struct tcpcb *tp, struct tcp_rack *rack, tcp_seq th_ack, uint8_t *quality)
3037 {
3038 	uint32_t tim, srtts, segsiz;
3039 
3040 	/*
3041 	 * Has enough time passed for the GP measurement to be valid?
3042 	 */
3043 	if ((tp->snd_max == tp->snd_una) ||
3044 	    (th_ack == tp->snd_max)){
3045 		/* All is acked */
3046 		*quality = RACK_QUALITY_ALLACKED;
3047 		return (1);
3048 	}
3049 	if (SEQ_LT(th_ack, tp->gput_seq)) {
3050 		/* Not enough bytes yet */
3051 		return (0);
3052 	}
3053 	segsiz = min(ctf_fixed_maxseg(tp), rack->r_ctl.rc_pace_min_segs);
3054 	if (SEQ_LT(th_ack, tp->gput_ack) &&
3055 	    ((th_ack - tp->gput_seq) < max(rc_init_window(rack), (MIN_GP_WIN * segsiz)))) {
3056 		/* Not enough bytes yet */
3057 		return (0);
3058 	}
3059 	if (rack->r_ctl.rc_first_appl &&
3060 	    (SEQ_GEQ(th_ack, rack->r_ctl.rc_first_appl->r_end))) {
3061 		/*
3062 		 * We are up to the app limited send point
3063 		 * we have to measure irrespective of the time..
3064 		 */
3065 		*quality = RACK_QUALITY_APPLIMITED;
3066 		return (1);
3067 	}
3068 	/* Now what about time? */
3069 	srtts = (rack->r_ctl.rc_gp_srtt * rack_min_srtts);
3070 	tim = tcp_tv_to_usectick(&rack->r_ctl.act_rcv_time) - tp->gput_ts;
3071 	if (tim >= srtts) {
3072 		*quality = RACK_QUALITY_HIGH;
3073 		return (1);
3074 	}
3075 	/* Nope not even a full SRTT has passed */
3076 	return (0);
3077 }
3078 
3079 static void
3080 rack_log_timely(struct tcp_rack *rack,
3081 		uint32_t logged, uint64_t cur_bw, uint64_t low_bnd,
3082 		uint64_t up_bnd, int line, uint8_t method)
3083 {
3084 	if (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
3085 		union tcp_log_stackspecific log;
3086 		struct timeval tv;
3087 
3088 		memset(&log, 0, sizeof(log));
3089 		log.u_bbr.flex1 = logged;
3090 		log.u_bbr.flex2 = rack->rc_gp_timely_inc_cnt;
3091 		log.u_bbr.flex2 <<= 4;
3092 		log.u_bbr.flex2 |= rack->rc_gp_timely_dec_cnt;
3093 		log.u_bbr.flex2 <<= 4;
3094 		log.u_bbr.flex2 |= rack->rc_gp_incr;
3095 		log.u_bbr.flex2 <<= 4;
3096 		log.u_bbr.flex2 |= rack->rc_gp_bwred;
3097 		log.u_bbr.flex3 = rack->rc_gp_incr;
3098 		log.u_bbr.flex4 = rack->r_ctl.rack_per_of_gp_ss;
3099 		log.u_bbr.flex5 = rack->r_ctl.rack_per_of_gp_ca;
3100 		log.u_bbr.flex6 = rack->r_ctl.rack_per_of_gp_rec;
3101 		log.u_bbr.flex7 = rack->rc_gp_bwred;
3102 		log.u_bbr.flex8 = method;
3103 		log.u_bbr.cur_del_rate = cur_bw;
3104 		log.u_bbr.delRate = low_bnd;
3105 		log.u_bbr.bw_inuse = up_bnd;
3106 		log.u_bbr.rttProp = rack_get_bw(rack);
3107 		log.u_bbr.pkt_epoch = line;
3108 		log.u_bbr.pkts_out = rack->r_ctl.rc_rtt_diff;
3109 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
3110 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
3111 		log.u_bbr.epoch = rack->r_ctl.rc_gp_srtt;
3112 		log.u_bbr.lt_epoch = rack->r_ctl.rc_prev_gp_srtt;
3113 		log.u_bbr.cwnd_gain = rack->rc_dragged_bottom;
3114 		log.u_bbr.cwnd_gain <<= 1;
3115 		log.u_bbr.cwnd_gain |= rack->rc_gp_saw_rec;
3116 		log.u_bbr.cwnd_gain <<= 1;
3117 		log.u_bbr.cwnd_gain |= rack->rc_gp_saw_ss;
3118 		log.u_bbr.cwnd_gain <<= 1;
3119 		log.u_bbr.cwnd_gain |= rack->rc_gp_saw_ca;
3120 		log.u_bbr.lost = rack->r_ctl.rc_loss_count;
3121 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
3122 		    &rack->rc_inp->inp_socket->so_rcv,
3123 		    &rack->rc_inp->inp_socket->so_snd,
3124 		    TCP_TIMELY_WORK, 0,
3125 		    0, &log, false, &tv);
3126 	}
3127 }
3128 
3129 static int
3130 rack_bw_can_be_raised(struct tcp_rack *rack, uint64_t cur_bw, uint64_t last_bw_est, uint16_t mult)
3131 {
3132 	/*
3133 	 * Before we increase we need to know if
3134 	 * the estimate just made was less than
3135 	 * our pacing goal (i.e. (cur_bw * mult) > last_bw_est)
3136 	 *
3137 	 * If we already are pacing at a fast enough
3138 	 * rate to push us faster there is no sense of
3139 	 * increasing.
3140 	 *
3141 	 * We first caculate our actual pacing rate (ss or ca multiplier
3142 	 * times our cur_bw).
3143 	 *
3144 	 * Then we take the last measured rate and multipy by our
3145 	 * maximum pacing overage to give us a max allowable rate.
3146 	 *
3147 	 * If our act_rate is smaller than our max_allowable rate
3148 	 * then we should increase. Else we should hold steady.
3149 	 *
3150 	 */
3151 	uint64_t act_rate, max_allow_rate;
3152 
3153 	if (rack_timely_no_stopping)
3154 		return (1);
3155 
3156 	if ((cur_bw == 0) || (last_bw_est == 0)) {
3157 		/*
3158 		 * Initial startup case or
3159 		 * everything is acked case.
3160 		 */
3161 		rack_log_timely(rack,  mult, cur_bw, 0, 0,
3162 				__LINE__, 9);
3163 		return (1);
3164 	}
3165 	if (mult <= 100) {
3166 		/*
3167 		 * We can always pace at or slightly above our rate.
3168 		 */
3169 		rack_log_timely(rack,  mult, cur_bw, 0, 0,
3170 				__LINE__, 9);
3171 		return (1);
3172 	}
3173 	act_rate = cur_bw * (uint64_t)mult;
3174 	act_rate /= 100;
3175 	max_allow_rate = last_bw_est * ((uint64_t)rack_max_per_above + (uint64_t)100);
3176 	max_allow_rate /= 100;
3177 	if (act_rate < max_allow_rate) {
3178 		/*
3179 		 * Here the rate we are actually pacing at
3180 		 * is smaller than 10% above our last measurement.
3181 		 * This means we are pacing below what we would
3182 		 * like to try to achieve (plus some wiggle room).
3183 		 */
3184 		rack_log_timely(rack,  mult, cur_bw, act_rate, max_allow_rate,
3185 				__LINE__, 9);
3186 		return (1);
3187 	} else {
3188 		/*
3189 		 * Here we are already pacing at least rack_max_per_above(10%)
3190 		 * what we are getting back. This indicates most likely
3191 		 * that we are being limited (cwnd/rwnd/app) and can't
3192 		 * get any more b/w. There is no sense of trying to
3193 		 * raise up the pacing rate its not speeding us up
3194 		 * and we already are pacing faster than we are getting.
3195 		 */
3196 		rack_log_timely(rack,  mult, cur_bw, act_rate, max_allow_rate,
3197 				__LINE__, 8);
3198 		return (0);
3199 	}
3200 }
3201 
3202 static void
3203 rack_validate_multipliers_at_or_above100(struct tcp_rack *rack)
3204 {
3205 	/*
3206 	 * When we drag bottom, we want to assure
3207 	 * that no multiplier is below 1.0, if so
3208 	 * we want to restore it to at least that.
3209 	 */
3210 	if (rack->r_ctl.rack_per_of_gp_rec  < 100) {
3211 		/* This is unlikely we usually do not touch recovery */
3212 		rack->r_ctl.rack_per_of_gp_rec = 100;
3213 	}
3214 	if (rack->r_ctl.rack_per_of_gp_ca < 100) {
3215 		rack->r_ctl.rack_per_of_gp_ca = 100;
3216 	}
3217 	if (rack->r_ctl.rack_per_of_gp_ss < 100) {
3218 		rack->r_ctl.rack_per_of_gp_ss = 100;
3219 	}
3220 }
3221 
3222 static void
3223 rack_validate_multipliers_at_or_below_100(struct tcp_rack *rack)
3224 {
3225 	if (rack->r_ctl.rack_per_of_gp_ca > 100) {
3226 		rack->r_ctl.rack_per_of_gp_ca = 100;
3227 	}
3228 	if (rack->r_ctl.rack_per_of_gp_ss > 100) {
3229 		rack->r_ctl.rack_per_of_gp_ss = 100;
3230 	}
3231 }
3232 
3233 static void
3234 rack_increase_bw_mul(struct tcp_rack *rack, int timely_says, uint64_t cur_bw, uint64_t last_bw_est, int override)
3235 {
3236 	int32_t  calc, logged, plus;
3237 
3238 	logged = 0;
3239 
3240 	if (override) {
3241 		/*
3242 		 * override is passed when we are
3243 		 * loosing b/w and making one last
3244 		 * gasp at trying to not loose out
3245 		 * to a new-reno flow.
3246 		 */
3247 		goto extra_boost;
3248 	}
3249 	/* In classic timely we boost by 5x if we have 5 increases in a row, lets not */
3250 	if (rack->rc_gp_incr &&
3251 	    ((rack->rc_gp_timely_inc_cnt + 1) >= RACK_TIMELY_CNT_BOOST)) {
3252 		/*
3253 		 * Reset and get 5 strokes more before the boost. Note
3254 		 * that the count is 0 based so we have to add one.
3255 		 */
3256 extra_boost:
3257 		plus = (uint32_t)rack_gp_increase_per * RACK_TIMELY_CNT_BOOST;
3258 		rack->rc_gp_timely_inc_cnt = 0;
3259 	} else
3260 		plus = (uint32_t)rack_gp_increase_per;
3261 	/* Must be at least 1% increase for true timely increases */
3262 	if ((plus < 1) &&
3263 	    ((rack->r_ctl.rc_rtt_diff <= 0) || (timely_says <= 0)))
3264 		plus = 1;
3265 	if (rack->rc_gp_saw_rec &&
3266 	    (rack->rc_gp_no_rec_chg == 0) &&
3267 	    rack_bw_can_be_raised(rack, cur_bw, last_bw_est,
3268 				  rack->r_ctl.rack_per_of_gp_rec)) {
3269 		/* We have been in recovery ding it too */
3270 		calc = rack->r_ctl.rack_per_of_gp_rec + plus;
3271 		if (calc > 0xffff)
3272 			calc = 0xffff;
3273 		logged |= 1;
3274 		rack->r_ctl.rack_per_of_gp_rec = (uint16_t)calc;
3275 		if (rack_per_upper_bound_ss &&
3276 		    (rack->rc_dragged_bottom == 0) &&
3277 		    (rack->r_ctl.rack_per_of_gp_rec > rack_per_upper_bound_ss))
3278 			rack->r_ctl.rack_per_of_gp_rec = rack_per_upper_bound_ss;
3279 	}
3280 	if (rack->rc_gp_saw_ca &&
3281 	    (rack->rc_gp_saw_ss == 0) &&
3282 	    rack_bw_can_be_raised(rack, cur_bw, last_bw_est,
3283 				  rack->r_ctl.rack_per_of_gp_ca)) {
3284 		/* In CA */
3285 		calc = rack->r_ctl.rack_per_of_gp_ca + plus;
3286 		if (calc > 0xffff)
3287 			calc = 0xffff;
3288 		logged |= 2;
3289 		rack->r_ctl.rack_per_of_gp_ca = (uint16_t)calc;
3290 		if (rack_per_upper_bound_ca &&
3291 		    (rack->rc_dragged_bottom == 0) &&
3292 		    (rack->r_ctl.rack_per_of_gp_ca > rack_per_upper_bound_ca))
3293 			rack->r_ctl.rack_per_of_gp_ca = rack_per_upper_bound_ca;
3294 	}
3295 	if (rack->rc_gp_saw_ss &&
3296 	    rack_bw_can_be_raised(rack, cur_bw, last_bw_est,
3297 				  rack->r_ctl.rack_per_of_gp_ss)) {
3298 		/* In SS */
3299 		calc = rack->r_ctl.rack_per_of_gp_ss + plus;
3300 		if (calc > 0xffff)
3301 			calc = 0xffff;
3302 		rack->r_ctl.rack_per_of_gp_ss = (uint16_t)calc;
3303 		if (rack_per_upper_bound_ss &&
3304 		    (rack->rc_dragged_bottom == 0) &&
3305 		    (rack->r_ctl.rack_per_of_gp_ss > rack_per_upper_bound_ss))
3306 			rack->r_ctl.rack_per_of_gp_ss = rack_per_upper_bound_ss;
3307 		logged |= 4;
3308 	}
3309 	if (logged &&
3310 	    (rack->rc_gp_incr == 0)){
3311 		/* Go into increment mode */
3312 		rack->rc_gp_incr = 1;
3313 		rack->rc_gp_timely_inc_cnt = 0;
3314 	}
3315 	if (rack->rc_gp_incr &&
3316 	    logged &&
3317 	    (rack->rc_gp_timely_inc_cnt < RACK_TIMELY_CNT_BOOST)) {
3318 		rack->rc_gp_timely_inc_cnt++;
3319 	}
3320 	rack_log_timely(rack,  logged, plus, 0, 0,
3321 			__LINE__, 1);
3322 }
3323 
3324 static uint32_t
3325 rack_get_decrease(struct tcp_rack *rack, uint32_t curper, int32_t rtt_diff)
3326 {
3327 	/*
3328 	 * norm_grad = rtt_diff / minrtt;
3329 	 * new_per = curper * (1 - B * norm_grad)
3330 	 *
3331 	 * B = rack_gp_decrease_per (default 10%)
3332 	 * rtt_dif = input var current rtt-diff
3333 	 * curper = input var current percentage
3334 	 * minrtt = from rack filter
3335 	 *
3336 	 */
3337 	uint64_t perf;
3338 
3339 	perf = (((uint64_t)curper * ((uint64_t)1000000 -
3340 		    ((uint64_t)rack_gp_decrease_per * (uint64_t)10000 *
3341 		     (((uint64_t)rtt_diff * (uint64_t)1000000)/
3342 		      (uint64_t)get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt)))/
3343 		     (uint64_t)1000000)) /
3344 		(uint64_t)1000000);
3345 	if (perf > curper) {
3346 		/* TSNH */
3347 		perf = curper - 1;
3348 	}
3349 	return ((uint32_t)perf);
3350 }
3351 
3352 static uint32_t
3353 rack_decrease_highrtt(struct tcp_rack *rack, uint32_t curper, uint32_t rtt)
3354 {
3355 	/*
3356 	 *                                   highrttthresh
3357 	 * result = curper * (1 - (B * ( 1 -  ------          ))
3358 	 *                                     gp_srtt
3359 	 *
3360 	 * B = rack_gp_decrease_per (default 10%)
3361 	 * highrttthresh = filter_min * rack_gp_rtt_maxmul
3362 	 */
3363 	uint64_t perf;
3364 	uint32_t highrttthresh;
3365 
3366 	highrttthresh = get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt) * rack_gp_rtt_maxmul;
3367 
3368 	perf = (((uint64_t)curper * ((uint64_t)1000000 -
3369 				     ((uint64_t)rack_gp_decrease_per * ((uint64_t)1000000 -
3370 					((uint64_t)highrttthresh * (uint64_t)1000000) /
3371 						    (uint64_t)rtt)) / 100)) /(uint64_t)1000000);
3372 	return (perf);
3373 }
3374 
3375 static void
3376 rack_decrease_bw_mul(struct tcp_rack *rack, int timely_says, uint32_t rtt, int32_t rtt_diff)
3377 {
3378 	uint64_t logvar, logvar2, logvar3;
3379 	uint32_t logged, new_per, ss_red, ca_red, rec_red, alt, val;
3380 
3381 	if (rack->rc_gp_incr) {
3382 		/* Turn off increment counting */
3383 		rack->rc_gp_incr = 0;
3384 		rack->rc_gp_timely_inc_cnt = 0;
3385 	}
3386 	ss_red = ca_red = rec_red = 0;
3387 	logged = 0;
3388 	/* Calculate the reduction value */
3389 	if (rtt_diff < 0) {
3390 		rtt_diff *= -1;
3391 	}
3392 	/* Must be at least 1% reduction */
3393 	if (rack->rc_gp_saw_rec && (rack->rc_gp_no_rec_chg == 0)) {
3394 		/* We have been in recovery ding it too */
3395 		if (timely_says == 2) {
3396 			new_per = rack_decrease_highrtt(rack, rack->r_ctl.rack_per_of_gp_rec, rtt);
3397 			alt = rack_get_decrease(rack, rack->r_ctl.rack_per_of_gp_rec, rtt_diff);
3398 			if (alt < new_per)
3399 				val = alt;
3400 			else
3401 				val = new_per;
3402 		} else
3403 			 val = new_per = alt = rack_get_decrease(rack, rack->r_ctl.rack_per_of_gp_rec, rtt_diff);
3404 		if (rack->r_ctl.rack_per_of_gp_rec > val) {
3405 			rec_red = (rack->r_ctl.rack_per_of_gp_rec - val);
3406 			rack->r_ctl.rack_per_of_gp_rec = (uint16_t)val;
3407 		} else {
3408 			rack->r_ctl.rack_per_of_gp_rec = rack_per_lower_bound;
3409 			rec_red = 0;
3410 		}
3411 		if (rack_per_lower_bound > rack->r_ctl.rack_per_of_gp_rec)
3412 			rack->r_ctl.rack_per_of_gp_rec = rack_per_lower_bound;
3413 		logged |= 1;
3414 	}
3415 	if (rack->rc_gp_saw_ss) {
3416 		/* Sent in SS */
3417 		if (timely_says == 2) {
3418 			new_per = rack_decrease_highrtt(rack, rack->r_ctl.rack_per_of_gp_ss, rtt);
3419 			alt = rack_get_decrease(rack, rack->r_ctl.rack_per_of_gp_rec, rtt_diff);
3420 			if (alt < new_per)
3421 				val = alt;
3422 			else
3423 				val = new_per;
3424 		} else
3425 			val = new_per = alt = rack_get_decrease(rack, rack->r_ctl.rack_per_of_gp_ss, rtt_diff);
3426 		if (rack->r_ctl.rack_per_of_gp_ss > new_per) {
3427 			ss_red = rack->r_ctl.rack_per_of_gp_ss - val;
3428 			rack->r_ctl.rack_per_of_gp_ss = (uint16_t)val;
3429 		} else {
3430 			ss_red = new_per;
3431 			rack->r_ctl.rack_per_of_gp_ss = rack_per_lower_bound;
3432 			logvar = new_per;
3433 			logvar <<= 32;
3434 			logvar |= alt;
3435 			logvar2 = (uint32_t)rtt;
3436 			logvar2 <<= 32;
3437 			logvar2 |= (uint32_t)rtt_diff;
3438 			logvar3 = rack_gp_rtt_maxmul;
3439 			logvar3 <<= 32;
3440 			logvar3 |= get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt);
3441 			rack_log_timely(rack, timely_says,
3442 					logvar2, logvar3,
3443 					logvar, __LINE__, 10);
3444 		}
3445 		if (rack_per_lower_bound > rack->r_ctl.rack_per_of_gp_ss)
3446 			rack->r_ctl.rack_per_of_gp_ss = rack_per_lower_bound;
3447 		logged |= 4;
3448 	} else if (rack->rc_gp_saw_ca) {
3449 		/* Sent in CA */
3450 		if (timely_says == 2) {
3451 			new_per = rack_decrease_highrtt(rack, rack->r_ctl.rack_per_of_gp_ca, rtt);
3452 			alt = rack_get_decrease(rack, rack->r_ctl.rack_per_of_gp_rec, rtt_diff);
3453 			if (alt < new_per)
3454 				val = alt;
3455 			else
3456 				val = new_per;
3457 		} else
3458 			val = new_per = alt = rack_get_decrease(rack, rack->r_ctl.rack_per_of_gp_ca, rtt_diff);
3459 		if (rack->r_ctl.rack_per_of_gp_ca > val) {
3460 			ca_red = rack->r_ctl.rack_per_of_gp_ca - val;
3461 			rack->r_ctl.rack_per_of_gp_ca = (uint16_t)val;
3462 		} else {
3463 			rack->r_ctl.rack_per_of_gp_ca = rack_per_lower_bound;
3464 			ca_red = 0;
3465 			logvar = new_per;
3466 			logvar <<= 32;
3467 			logvar |= alt;
3468 			logvar2 = (uint32_t)rtt;
3469 			logvar2 <<= 32;
3470 			logvar2 |= (uint32_t)rtt_diff;
3471 			logvar3 = rack_gp_rtt_maxmul;
3472 			logvar3 <<= 32;
3473 			logvar3 |= get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt);
3474 			rack_log_timely(rack, timely_says,
3475 					logvar2, logvar3,
3476 					logvar, __LINE__, 10);
3477 		}
3478 		if (rack_per_lower_bound > rack->r_ctl.rack_per_of_gp_ca)
3479 			rack->r_ctl.rack_per_of_gp_ca = rack_per_lower_bound;
3480 		logged |= 2;
3481 	}
3482 	if (rack->rc_gp_timely_dec_cnt < 0x7) {
3483 		rack->rc_gp_timely_dec_cnt++;
3484 		if (rack_timely_dec_clear &&
3485 		    (rack->rc_gp_timely_dec_cnt == rack_timely_dec_clear))
3486 			rack->rc_gp_timely_dec_cnt = 0;
3487 	}
3488 	logvar = ss_red;
3489 	logvar <<= 32;
3490 	logvar |= ca_red;
3491 	rack_log_timely(rack,  logged, rec_red, rack_per_lower_bound, logvar,
3492 			__LINE__, 2);
3493 }
3494 
3495 static void
3496 rack_log_rtt_shrinks(struct tcp_rack *rack, uint32_t us_cts,
3497 		     uint32_t rtt, uint32_t line, uint8_t reas)
3498 {
3499 	if (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
3500 		union tcp_log_stackspecific log;
3501 		struct timeval tv;
3502 
3503 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
3504 		log.u_bbr.flex1 = line;
3505 		log.u_bbr.flex2 = rack->r_ctl.rc_time_probertt_starts;
3506 		log.u_bbr.flex3 = rack->r_ctl.rc_lower_rtt_us_cts;
3507 		log.u_bbr.flex4 = rack->r_ctl.rack_per_of_gp_ss;
3508 		log.u_bbr.flex5 = rtt;
3509 		log.u_bbr.flex6 = rack->rc_highly_buffered;
3510 		log.u_bbr.flex6 <<= 1;
3511 		log.u_bbr.flex6 |= rack->forced_ack;
3512 		log.u_bbr.flex6 <<= 1;
3513 		log.u_bbr.flex6 |= rack->rc_gp_dyn_mul;
3514 		log.u_bbr.flex6 <<= 1;
3515 		log.u_bbr.flex6 |= rack->in_probe_rtt;
3516 		log.u_bbr.flex6 <<= 1;
3517 		log.u_bbr.flex6 |= rack->measure_saw_probe_rtt;
3518 		log.u_bbr.flex7 = rack->r_ctl.rack_per_of_gp_probertt;
3519 		log.u_bbr.pacing_gain = rack->r_ctl.rack_per_of_gp_ca;
3520 		log.u_bbr.cwnd_gain = rack->r_ctl.rack_per_of_gp_rec;
3521 		log.u_bbr.flex8 = reas;
3522 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
3523 		log.u_bbr.delRate = rack_get_bw(rack);
3524 		log.u_bbr.cur_del_rate = rack->r_ctl.rc_highest_us_rtt;
3525 		log.u_bbr.cur_del_rate <<= 32;
3526 		log.u_bbr.cur_del_rate |= rack->r_ctl.rc_lowest_us_rtt;
3527 		log.u_bbr.applimited = rack->r_ctl.rc_time_probertt_entered;
3528 		log.u_bbr.pkts_out = rack->r_ctl.rc_rtt_diff;
3529 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
3530 		log.u_bbr.epoch = rack->r_ctl.rc_gp_srtt;
3531 		log.u_bbr.lt_epoch = rack->r_ctl.rc_prev_gp_srtt;
3532 		log.u_bbr.pkt_epoch = rack->r_ctl.rc_lower_rtt_us_cts;
3533 		log.u_bbr.delivered = rack->r_ctl.rc_target_probertt_flight;
3534 		log.u_bbr.lost = get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt);
3535 		log.u_bbr.rttProp = us_cts;
3536 		log.u_bbr.rttProp <<= 32;
3537 		log.u_bbr.rttProp |= rack->r_ctl.rc_entry_gp_rtt;
3538 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
3539 		    &rack->rc_inp->inp_socket->so_rcv,
3540 		    &rack->rc_inp->inp_socket->so_snd,
3541 		    BBR_LOG_RTT_SHRINKS, 0,
3542 		    0, &log, false, &rack->r_ctl.act_rcv_time);
3543 	}
3544 }
3545 
3546 static void
3547 rack_set_prtt_target(struct tcp_rack *rack, uint32_t segsiz, uint32_t rtt)
3548 {
3549 	uint64_t bwdp;
3550 
3551 	bwdp = rack_get_bw(rack);
3552 	bwdp *= (uint64_t)rtt;
3553 	bwdp /= (uint64_t)HPTS_USEC_IN_SEC;
3554 	rack->r_ctl.rc_target_probertt_flight = roundup((uint32_t)bwdp, segsiz);
3555 	if (rack->r_ctl.rc_target_probertt_flight < (segsiz * rack_timely_min_segs)) {
3556 		/*
3557 		 * A window protocol must be able to have 4 packets
3558 		 * outstanding as the floor in order to function
3559 		 * (especially considering delayed ack :D).
3560 		 */
3561 		rack->r_ctl.rc_target_probertt_flight = (segsiz * rack_timely_min_segs);
3562 	}
3563 }
3564 
3565 static void
3566 rack_enter_probertt(struct tcp_rack *rack, uint32_t us_cts)
3567 {
3568 	/**
3569 	 * ProbeRTT is a bit different in rack_pacing than in
3570 	 * BBR. It is like BBR in that it uses the lowering of
3571 	 * the RTT as a signal that we saw something new and
3572 	 * counts from there for how long between. But it is
3573 	 * different in that its quite simple. It does not
3574 	 * play with the cwnd and wait until we get down
3575 	 * to N segments outstanding and hold that for
3576 	 * 200ms. Instead it just sets the pacing reduction
3577 	 * rate to a set percentage (70 by default) and hold
3578 	 * that for a number of recent GP Srtt's.
3579 	 */
3580 	uint32_t segsiz;
3581 
3582 	if (rack->rc_gp_dyn_mul == 0)
3583 		return;
3584 
3585 	if (rack->rc_tp->snd_max == rack->rc_tp->snd_una) {
3586 		/* We are idle */
3587 		return;
3588 	}
3589 	if ((rack->rc_tp->t_flags & TF_GPUTINPROG) &&
3590 	    SEQ_GT(rack->rc_tp->snd_una, rack->rc_tp->gput_seq)) {
3591 		/*
3592 		 * Stop the goodput now, the idea here is
3593 		 * that future measurements with in_probe_rtt
3594 		 * won't register if they are not greater so
3595 		 * we want to get what info (if any) is available
3596 		 * now.
3597 		 */
3598 		rack_do_goodput_measurement(rack->rc_tp, rack,
3599 					    rack->rc_tp->snd_una, __LINE__,
3600 					    RACK_QUALITY_PROBERTT);
3601 	}
3602 	rack->r_ctl.rack_per_of_gp_probertt = rack_per_of_gp_probertt;
3603 	rack->r_ctl.rc_time_probertt_entered = us_cts;
3604 	segsiz = min(ctf_fixed_maxseg(rack->rc_tp),
3605 		     rack->r_ctl.rc_pace_min_segs);
3606 	rack->in_probe_rtt = 1;
3607 	rack->measure_saw_probe_rtt = 1;
3608 	rack->r_ctl.rc_lower_rtt_us_cts = us_cts;
3609 	rack->r_ctl.rc_time_probertt_starts = 0;
3610 	rack->r_ctl.rc_entry_gp_rtt = rack->r_ctl.rc_gp_srtt;
3611 	if (rack_probertt_use_min_rtt_entry)
3612 		rack_set_prtt_target(rack, segsiz, get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt));
3613 	else
3614 		rack_set_prtt_target(rack, segsiz, rack->r_ctl.rc_gp_srtt);
3615 	rack_log_rtt_shrinks(rack,  us_cts,  get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt),
3616 			     __LINE__, RACK_RTTS_ENTERPROBE);
3617 }
3618 
3619 static void
3620 rack_exit_probertt(struct tcp_rack *rack, uint32_t us_cts)
3621 {
3622 	struct rack_sendmap *rsm;
3623 	uint32_t segsiz;
3624 
3625 	segsiz = min(ctf_fixed_maxseg(rack->rc_tp),
3626 		     rack->r_ctl.rc_pace_min_segs);
3627 	rack->in_probe_rtt = 0;
3628 	if ((rack->rc_tp->t_flags & TF_GPUTINPROG) &&
3629 	    SEQ_GT(rack->rc_tp->snd_una, rack->rc_tp->gput_seq)) {
3630 		/*
3631 		 * Stop the goodput now, the idea here is
3632 		 * that future measurements with in_probe_rtt
3633 		 * won't register if they are not greater so
3634 		 * we want to get what info (if any) is available
3635 		 * now.
3636 		 */
3637 		rack_do_goodput_measurement(rack->rc_tp, rack,
3638 					    rack->rc_tp->snd_una, __LINE__,
3639 					    RACK_QUALITY_PROBERTT);
3640 	} else if (rack->rc_tp->t_flags & TF_GPUTINPROG) {
3641 		/*
3642 		 * We don't have enough data to make a measurement.
3643 		 * So lets just stop and start here after exiting
3644 		 * probe-rtt. We probably are not interested in
3645 		 * the results anyway.
3646 		 */
3647 		rack->rc_tp->t_flags &= ~TF_GPUTINPROG;
3648 	}
3649 	/*
3650 	 * Measurements through the current snd_max are going
3651 	 * to be limited by the slower pacing rate.
3652 	 *
3653 	 * We need to mark these as app-limited so we
3654 	 * don't collapse the b/w.
3655 	 */
3656 	rsm = RB_MAX(rack_rb_tree_head, &rack->r_ctl.rc_mtree);
3657 	if (rsm && ((rsm->r_flags & RACK_APP_LIMITED) == 0)) {
3658 		if (rack->r_ctl.rc_app_limited_cnt == 0)
3659 			rack->r_ctl.rc_end_appl = rack->r_ctl.rc_first_appl = rsm;
3660 		else {
3661 			/*
3662 			 * Go out to the end app limited and mark
3663 			 * this new one as next and move the end_appl up
3664 			 * to this guy.
3665 			 */
3666 			if (rack->r_ctl.rc_end_appl)
3667 				rack->r_ctl.rc_end_appl->r_nseq_appl = rsm->r_start;
3668 			rack->r_ctl.rc_end_appl = rsm;
3669 		}
3670 		rsm->r_flags |= RACK_APP_LIMITED;
3671 		rack->r_ctl.rc_app_limited_cnt++;
3672 	}
3673 	/*
3674 	 * Now, we need to examine our pacing rate multipliers.
3675 	 * If its under 100%, we need to kick it back up to
3676 	 * 100%. We also don't let it be over our "max" above
3677 	 * the actual rate i.e. 100% + rack_clamp_atexit_prtt.
3678 	 * Note setting clamp_atexit_prtt to 0 has the effect
3679 	 * of setting CA/SS to 100% always at exit (which is
3680 	 * the default behavior).
3681 	 */
3682 	if (rack_probertt_clear_is) {
3683 		rack->rc_gp_incr = 0;
3684 		rack->rc_gp_bwred = 0;
3685 		rack->rc_gp_timely_inc_cnt = 0;
3686 		rack->rc_gp_timely_dec_cnt = 0;
3687 	}
3688 	/* Do we do any clamping at exit? */
3689 	if (rack->rc_highly_buffered && rack_atexit_prtt_hbp) {
3690 		rack->r_ctl.rack_per_of_gp_ca = rack_atexit_prtt_hbp;
3691 		rack->r_ctl.rack_per_of_gp_ss = rack_atexit_prtt_hbp;
3692 	}
3693 	if ((rack->rc_highly_buffered == 0) && rack_atexit_prtt) {
3694 		rack->r_ctl.rack_per_of_gp_ca = rack_atexit_prtt;
3695 		rack->r_ctl.rack_per_of_gp_ss = rack_atexit_prtt;
3696 	}
3697 	/*
3698 	 * Lets set rtt_diff to 0, so that we will get a "boost"
3699 	 * after exiting.
3700 	 */
3701 	rack->r_ctl.rc_rtt_diff = 0;
3702 
3703 	/* Clear all flags so we start fresh */
3704 	rack->rc_tp->t_bytes_acked = 0;
3705 	rack->rc_tp->ccv->flags &= ~CCF_ABC_SENTAWND;
3706 	/*
3707 	 * If configured to, set the cwnd and ssthresh to
3708 	 * our targets.
3709 	 */
3710 	if (rack_probe_rtt_sets_cwnd) {
3711 		uint64_t ebdp;
3712 		uint32_t setto;
3713 
3714 		/* Set ssthresh so we get into CA once we hit our target */
3715 		if (rack_probertt_use_min_rtt_exit == 1) {
3716 			/* Set to min rtt */
3717 			rack_set_prtt_target(rack, segsiz,
3718 					     get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt));
3719 		} else if (rack_probertt_use_min_rtt_exit == 2) {
3720 			/* Set to current gp rtt */
3721 			rack_set_prtt_target(rack, segsiz,
3722 					     rack->r_ctl.rc_gp_srtt);
3723 		} else if (rack_probertt_use_min_rtt_exit == 3) {
3724 			/* Set to entry gp rtt */
3725 			rack_set_prtt_target(rack, segsiz,
3726 					     rack->r_ctl.rc_entry_gp_rtt);
3727 		} else {
3728 			uint64_t sum;
3729 			uint32_t setval;
3730 
3731 			sum = rack->r_ctl.rc_entry_gp_rtt;
3732 			sum *= 10;
3733 			sum /= (uint64_t)(max(1, rack->r_ctl.rc_gp_srtt));
3734 			if (sum >= 20) {
3735 				/*
3736 				 * A highly buffered path needs
3737 				 * cwnd space for timely to work.
3738 				 * Lets set things up as if
3739 				 * we are heading back here again.
3740 				 */
3741 				setval = rack->r_ctl.rc_entry_gp_rtt;
3742 			} else if (sum >= 15) {
3743 				/*
3744 				 * Lets take the smaller of the
3745 				 * two since we are just somewhat
3746 				 * buffered.
3747 				 */
3748 				setval = rack->r_ctl.rc_gp_srtt;
3749 				if (setval > rack->r_ctl.rc_entry_gp_rtt)
3750 					setval = rack->r_ctl.rc_entry_gp_rtt;
3751 			} else {
3752 				/*
3753 				 * Here we are not highly buffered
3754 				 * and should pick the min we can to
3755 				 * keep from causing loss.
3756 				 */
3757 				setval = get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt);
3758 			}
3759 			rack_set_prtt_target(rack, segsiz,
3760 					     setval);
3761 		}
3762 		if (rack_probe_rtt_sets_cwnd > 1) {
3763 			/* There is a percentage here to boost */
3764 			ebdp = rack->r_ctl.rc_target_probertt_flight;
3765 			ebdp *= rack_probe_rtt_sets_cwnd;
3766 			ebdp /= 100;
3767 			setto = rack->r_ctl.rc_target_probertt_flight + ebdp;
3768 		} else
3769 			setto = rack->r_ctl.rc_target_probertt_flight;
3770 		rack->rc_tp->snd_cwnd = roundup(setto, segsiz);
3771 		if (rack->rc_tp->snd_cwnd < (segsiz * rack_timely_min_segs)) {
3772 			/* Enforce a min */
3773 			rack->rc_tp->snd_cwnd = segsiz * rack_timely_min_segs;
3774 		}
3775 		/* If we set in the cwnd also set the ssthresh point so we are in CA */
3776 		rack->rc_tp->snd_ssthresh = (rack->rc_tp->snd_cwnd - 1);
3777 	}
3778 	rack_log_rtt_shrinks(rack,  us_cts,
3779 			     get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt),
3780 			     __LINE__, RACK_RTTS_EXITPROBE);
3781 	/* Clear times last so log has all the info */
3782 	rack->r_ctl.rc_probertt_sndmax_atexit = rack->rc_tp->snd_max;
3783 	rack->r_ctl.rc_time_probertt_entered = us_cts;
3784 	rack->r_ctl.rc_time_probertt_starts = rack->r_ctl.rc_lower_rtt_us_cts = us_cts;
3785 	rack->r_ctl.rc_time_of_last_probertt = us_cts;
3786 }
3787 
3788 static void
3789 rack_check_probe_rtt(struct tcp_rack *rack, uint32_t us_cts)
3790 {
3791 	/* Check in on probe-rtt */
3792 	if (rack->rc_gp_filled == 0) {
3793 		/* We do not do p-rtt unless we have gp measurements */
3794 		return;
3795 	}
3796 	if (rack->in_probe_rtt) {
3797 		uint64_t no_overflow;
3798 		uint32_t endtime, must_stay;
3799 
3800 		if (rack->r_ctl.rc_went_idle_time &&
3801 		    ((us_cts - rack->r_ctl.rc_went_idle_time) > rack_min_probertt_hold)) {
3802 			/*
3803 			 * We went idle during prtt, just exit now.
3804 			 */
3805 			rack_exit_probertt(rack, us_cts);
3806 		} else if (rack_probe_rtt_safety_val &&
3807 		    TSTMP_GT(us_cts, rack->r_ctl.rc_time_probertt_entered) &&
3808 		    ((us_cts - rack->r_ctl.rc_time_probertt_entered) > rack_probe_rtt_safety_val)) {
3809 			/*
3810 			 * Probe RTT safety value triggered!
3811 			 */
3812 			rack_log_rtt_shrinks(rack,  us_cts,
3813 					     get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt),
3814 					     __LINE__, RACK_RTTS_SAFETY);
3815 			rack_exit_probertt(rack, us_cts);
3816 		}
3817 		/* Calculate the max we will wait */
3818 		endtime = rack->r_ctl.rc_time_probertt_entered + (rack->r_ctl.rc_gp_srtt * rack_max_drain_wait);
3819 		if (rack->rc_highly_buffered)
3820 			endtime += (rack->r_ctl.rc_gp_srtt * rack_max_drain_hbp);
3821 		/* Calculate the min we must wait */
3822 		must_stay = rack->r_ctl.rc_time_probertt_entered + (rack->r_ctl.rc_gp_srtt * rack_must_drain);
3823 		if ((ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked) > rack->r_ctl.rc_target_probertt_flight) &&
3824 		    TSTMP_LT(us_cts, endtime)) {
3825 			uint32_t calc;
3826 			/* Do we lower more? */
3827 no_exit:
3828 			if (TSTMP_GT(us_cts, rack->r_ctl.rc_time_probertt_entered))
3829 				calc = us_cts - rack->r_ctl.rc_time_probertt_entered;
3830 			else
3831 				calc = 0;
3832 			calc /= max(rack->r_ctl.rc_gp_srtt, 1);
3833 			if (calc) {
3834 				/* Maybe */
3835 				calc *= rack_per_of_gp_probertt_reduce;
3836 				rack->r_ctl.rack_per_of_gp_probertt = rack_per_of_gp_probertt - calc;
3837 				/* Limit it too */
3838 				if (rack->r_ctl.rack_per_of_gp_probertt < rack_per_of_gp_lowthresh)
3839 					rack->r_ctl.rack_per_of_gp_probertt = rack_per_of_gp_lowthresh;
3840 			}
3841 			/* We must reach target or the time set */
3842 			return;
3843 		}
3844 		if (rack->r_ctl.rc_time_probertt_starts == 0) {
3845 			if ((TSTMP_LT(us_cts, must_stay) &&
3846 			     rack->rc_highly_buffered) ||
3847 			     (ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked) >
3848 			      rack->r_ctl.rc_target_probertt_flight)) {
3849 				/* We are not past the must_stay time */
3850 				goto no_exit;
3851 			}
3852 			rack_log_rtt_shrinks(rack,  us_cts,
3853 					     get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt),
3854 					     __LINE__, RACK_RTTS_REACHTARGET);
3855 			rack->r_ctl.rc_time_probertt_starts = us_cts;
3856 			if (rack->r_ctl.rc_time_probertt_starts == 0)
3857 				rack->r_ctl.rc_time_probertt_starts = 1;
3858 			/* Restore back to our rate we want to pace at in prtt */
3859 			rack->r_ctl.rack_per_of_gp_probertt = rack_per_of_gp_probertt;
3860 		}
3861 		/*
3862 		 * Setup our end time, some number of gp_srtts plus 200ms.
3863 		 */
3864 		no_overflow = ((uint64_t)rack->r_ctl.rc_gp_srtt *
3865 			       (uint64_t)rack_probertt_gpsrtt_cnt_mul);
3866 		if (rack_probertt_gpsrtt_cnt_div)
3867 			endtime = (uint32_t)(no_overflow / (uint64_t)rack_probertt_gpsrtt_cnt_div);
3868 		else
3869 			endtime = 0;
3870 		endtime += rack_min_probertt_hold;
3871 		endtime += rack->r_ctl.rc_time_probertt_starts;
3872 		if (TSTMP_GEQ(us_cts,  endtime)) {
3873 			/* yes, exit probertt */
3874 			rack_exit_probertt(rack, us_cts);
3875 		}
3876 
3877 	} else if ((us_cts - rack->r_ctl.rc_lower_rtt_us_cts) >= rack_time_between_probertt) {
3878 		/* Go into probertt, its been too long since we went lower */
3879 		rack_enter_probertt(rack, us_cts);
3880 	}
3881 }
3882 
3883 static void
3884 rack_update_multiplier(struct tcp_rack *rack, int32_t timely_says, uint64_t last_bw_est,
3885 		       uint32_t rtt, int32_t rtt_diff)
3886 {
3887 	uint64_t cur_bw, up_bnd, low_bnd, subfr;
3888 	uint32_t losses;
3889 
3890 	if ((rack->rc_gp_dyn_mul == 0) ||
3891 	    (rack->use_fixed_rate) ||
3892 	    (rack->in_probe_rtt) ||
3893 	    (rack->rc_always_pace == 0)) {
3894 		/* No dynamic GP multiplier in play */
3895 		return;
3896 	}
3897 	losses = rack->r_ctl.rc_loss_count - rack->r_ctl.rc_loss_at_start;
3898 	cur_bw = rack_get_bw(rack);
3899 	/* Calculate our up and down range */
3900 	up_bnd = rack->r_ctl.last_gp_comp_bw * (uint64_t)rack_gp_per_bw_mul_up;
3901 	up_bnd /= 100;
3902 	up_bnd += rack->r_ctl.last_gp_comp_bw;
3903 
3904 	subfr = (uint64_t)rack->r_ctl.last_gp_comp_bw * (uint64_t)rack_gp_per_bw_mul_down;
3905 	subfr /= 100;
3906 	low_bnd = rack->r_ctl.last_gp_comp_bw - subfr;
3907 	if ((timely_says == 2) && (rack->r_ctl.rc_no_push_at_mrtt)) {
3908 		/*
3909 		 * This is the case where our RTT is above
3910 		 * the max target and we have been configured
3911 		 * to just do timely no bonus up stuff in that case.
3912 		 *
3913 		 * There are two configurations, set to 1, and we
3914 		 * just do timely if we are over our max. If its
3915 		 * set above 1 then we slam the multipliers down
3916 		 * to 100 and then decrement per timely.
3917 		 */
3918 		rack_log_timely(rack,  timely_says, cur_bw, low_bnd, up_bnd,
3919 				__LINE__, 3);
3920 		if (rack->r_ctl.rc_no_push_at_mrtt > 1)
3921 			rack_validate_multipliers_at_or_below_100(rack);
3922 		rack_decrease_bw_mul(rack, timely_says, rtt, rtt_diff);
3923 	} else if ((last_bw_est < low_bnd) && !losses) {
3924 		/*
3925 		 * We are decreasing this is a bit complicated this
3926 		 * means we are loosing ground. This could be
3927 		 * because another flow entered and we are competing
3928 		 * for b/w with it. This will push the RTT up which
3929 		 * makes timely unusable unless we want to get shoved
3930 		 * into a corner and just be backed off (the age
3931 		 * old problem with delay based CC).
3932 		 *
3933 		 * On the other hand if it was a route change we
3934 		 * would like to stay somewhat contained and not
3935 		 * blow out the buffers.
3936 		 */
3937 		rack_log_timely(rack,  timely_says, cur_bw, low_bnd, up_bnd,
3938 				__LINE__, 3);
3939 		rack->r_ctl.last_gp_comp_bw = cur_bw;
3940 		if (rack->rc_gp_bwred == 0) {
3941 			/* Go into reduction counting */
3942 			rack->rc_gp_bwred = 1;
3943 			rack->rc_gp_timely_dec_cnt = 0;
3944 		}
3945 		if ((rack->rc_gp_timely_dec_cnt < rack_timely_max_push_drop) ||
3946 		    (timely_says == 0)) {
3947 			/*
3948 			 * Push another time with a faster pacing
3949 			 * to try to gain back (we include override to
3950 			 * get a full raise factor).
3951 			 */
3952 			if ((rack->rc_gp_saw_ca && rack->r_ctl.rack_per_of_gp_ca <= rack_down_raise_thresh) ||
3953 			    (rack->rc_gp_saw_ss && rack->r_ctl.rack_per_of_gp_ss <= rack_down_raise_thresh) ||
3954 			    (timely_says == 0) ||
3955 			    (rack_down_raise_thresh == 0)) {
3956 				/*
3957 				 * Do an override up in b/w if we were
3958 				 * below the threshold or if the threshold
3959 				 * is zero we always do the raise.
3960 				 */
3961 				rack_increase_bw_mul(rack, timely_says, cur_bw, last_bw_est, 1);
3962 			} else {
3963 				/* Log it stays the same */
3964 				rack_log_timely(rack,  0, last_bw_est, low_bnd, 0,
3965 						__LINE__, 11);
3966 			}
3967 			rack->rc_gp_timely_dec_cnt++;
3968 			/* We are not incrementing really no-count */
3969 			rack->rc_gp_incr = 0;
3970 			rack->rc_gp_timely_inc_cnt = 0;
3971 		} else {
3972 			/*
3973 			 * Lets just use the RTT
3974 			 * information and give up
3975 			 * pushing.
3976 			 */
3977 			goto use_timely;
3978 		}
3979 	} else if ((timely_says != 2) &&
3980 		    !losses &&
3981 		    (last_bw_est > up_bnd)) {
3982 		/*
3983 		 * We are increasing b/w lets keep going, updating
3984 		 * our b/w and ignoring any timely input, unless
3985 		 * of course we are at our max raise (if there is one).
3986 		 */
3987 
3988 		rack_log_timely(rack,  timely_says, cur_bw, low_bnd, up_bnd,
3989 				__LINE__, 3);
3990 		rack->r_ctl.last_gp_comp_bw = cur_bw;
3991 		if (rack->rc_gp_saw_ss &&
3992 		    rack_per_upper_bound_ss &&
3993 		     (rack->r_ctl.rack_per_of_gp_ss == rack_per_upper_bound_ss)) {
3994 			    /*
3995 			     * In cases where we can't go higher
3996 			     * we should just use timely.
3997 			     */
3998 			    goto use_timely;
3999 		}
4000 		if (rack->rc_gp_saw_ca &&
4001 		    rack_per_upper_bound_ca &&
4002 		    (rack->r_ctl.rack_per_of_gp_ca == rack_per_upper_bound_ca)) {
4003 			    /*
4004 			     * In cases where we can't go higher
4005 			     * we should just use timely.
4006 			     */
4007 			    goto use_timely;
4008 		}
4009 		rack->rc_gp_bwred = 0;
4010 		rack->rc_gp_timely_dec_cnt = 0;
4011 		/* You get a set number of pushes if timely is trying to reduce */
4012 		if ((rack->rc_gp_incr < rack_timely_max_push_rise) || (timely_says == 0)) {
4013 			rack_increase_bw_mul(rack, timely_says, cur_bw, last_bw_est, 0);
4014 		} else {
4015 			/* Log it stays the same */
4016 			rack_log_timely(rack,  0, last_bw_est, up_bnd, 0,
4017 			    __LINE__, 12);
4018 		}
4019 		return;
4020 	} else {
4021 		/*
4022 		 * We are staying between the lower and upper range bounds
4023 		 * so use timely to decide.
4024 		 */
4025 		rack_log_timely(rack,  timely_says, cur_bw, low_bnd, up_bnd,
4026 				__LINE__, 3);
4027 use_timely:
4028 		if (timely_says) {
4029 			rack->rc_gp_incr = 0;
4030 			rack->rc_gp_timely_inc_cnt = 0;
4031 			if ((rack->rc_gp_timely_dec_cnt < rack_timely_max_push_drop) &&
4032 			    !losses &&
4033 			    (last_bw_est < low_bnd)) {
4034 				/* We are loosing ground */
4035 				rack_increase_bw_mul(rack, timely_says, cur_bw, last_bw_est, 0);
4036 				rack->rc_gp_timely_dec_cnt++;
4037 				/* We are not incrementing really no-count */
4038 				rack->rc_gp_incr = 0;
4039 				rack->rc_gp_timely_inc_cnt = 0;
4040 			} else
4041 				rack_decrease_bw_mul(rack, timely_says, rtt, rtt_diff);
4042 		} else {
4043 			rack->rc_gp_bwred = 0;
4044 			rack->rc_gp_timely_dec_cnt = 0;
4045 			rack_increase_bw_mul(rack, timely_says, cur_bw, last_bw_est, 0);
4046 		}
4047 	}
4048 }
4049 
4050 static int32_t
4051 rack_make_timely_judgement(struct tcp_rack *rack, uint32_t rtt, int32_t rtt_diff, uint32_t prev_rtt)
4052 {
4053 	int32_t timely_says;
4054 	uint64_t log_mult, log_rtt_a_diff;
4055 
4056 	log_rtt_a_diff = rtt;
4057 	log_rtt_a_diff <<= 32;
4058 	log_rtt_a_diff |= (uint32_t)rtt_diff;
4059 	if (rtt >= (get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt) *
4060 		    rack_gp_rtt_maxmul)) {
4061 		/* Reduce the b/w multiplier */
4062 		timely_says = 2;
4063 		log_mult = get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt) * rack_gp_rtt_maxmul;
4064 		log_mult <<= 32;
4065 		log_mult |= prev_rtt;
4066 		rack_log_timely(rack,  timely_says, log_mult,
4067 				get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt),
4068 				log_rtt_a_diff, __LINE__, 4);
4069 	} else if (rtt <= (get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt) +
4070 			   ((get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt) * rack_gp_rtt_minmul) /
4071 			    max(rack_gp_rtt_mindiv , 1)))) {
4072 		/* Increase the b/w multiplier */
4073 		log_mult = get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt) +
4074 			((get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt) * rack_gp_rtt_minmul) /
4075 			 max(rack_gp_rtt_mindiv , 1));
4076 		log_mult <<= 32;
4077 		log_mult |= prev_rtt;
4078 		timely_says = 0;
4079 		rack_log_timely(rack,  timely_says, log_mult ,
4080 				get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt),
4081 				log_rtt_a_diff, __LINE__, 5);
4082 	} else {
4083 		/*
4084 		 * Use a gradient to find it the timely gradient
4085 		 * is:
4086 		 * grad = rc_rtt_diff / min_rtt;
4087 		 *
4088 		 * anything below or equal to 0 will be
4089 		 * a increase indication. Anything above
4090 		 * zero is a decrease. Note we take care
4091 		 * of the actual gradient calculation
4092 		 * in the reduction (its not needed for
4093 		 * increase).
4094 		 */
4095 		log_mult = prev_rtt;
4096 		if (rtt_diff <= 0) {
4097 			/*
4098 			 * Rttdiff is less than zero, increase the
4099 			 * b/w multiplier (its 0 or negative)
4100 			 */
4101 			timely_says = 0;
4102 			rack_log_timely(rack,  timely_says, log_mult,
4103 					get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt), log_rtt_a_diff, __LINE__, 6);
4104 		} else {
4105 			/* Reduce the b/w multiplier */
4106 			timely_says = 1;
4107 			rack_log_timely(rack,  timely_says, log_mult,
4108 					get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt), log_rtt_a_diff, __LINE__, 7);
4109 		}
4110 	}
4111 	return (timely_says);
4112 }
4113 
4114 static void
4115 rack_do_goodput_measurement(struct tcpcb *tp, struct tcp_rack *rack,
4116 			    tcp_seq th_ack, int line, uint8_t quality)
4117 {
4118 	uint64_t tim, bytes_ps, ltim, stim, utim;
4119 	uint32_t segsiz, bytes, reqbytes, us_cts;
4120 	int32_t gput, new_rtt_diff, timely_says;
4121 	uint64_t  resid_bw, subpart = 0, addpart = 0, srtt;
4122 	int did_add = 0;
4123 
4124 	us_cts = tcp_tv_to_usectick(&rack->r_ctl.act_rcv_time);
4125 	segsiz = min(ctf_fixed_maxseg(tp), rack->r_ctl.rc_pace_min_segs);
4126 	if (TSTMP_GEQ(us_cts, tp->gput_ts))
4127 		tim = us_cts - tp->gput_ts;
4128 	else
4129 		tim = 0;
4130 	if (rack->r_ctl.rc_gp_cumack_ts > rack->r_ctl.rc_gp_output_ts)
4131 		stim = rack->r_ctl.rc_gp_cumack_ts - rack->r_ctl.rc_gp_output_ts;
4132 	else
4133 		stim = 0;
4134 	/*
4135 	 * Use the larger of the send time or ack time. This prevents us
4136 	 * from being influenced by ack artifacts to come up with too
4137 	 * high of measurement. Note that since we are spanning over many more
4138 	 * bytes in most of our measurements hopefully that is less likely to
4139 	 * occur.
4140 	 */
4141 	if (tim > stim)
4142 		utim = max(tim, 1);
4143 	else
4144 		utim = max(stim, 1);
4145 	/* Lets get a msec time ltim too for the old stuff */
4146 	ltim = max(1, (utim / HPTS_USEC_IN_MSEC));
4147 	gput = (((uint64_t) (th_ack - tp->gput_seq)) << 3) / ltim;
4148 	reqbytes = min(rc_init_window(rack), (MIN_GP_WIN * segsiz));
4149 	if ((tim == 0) && (stim == 0)) {
4150 		/*
4151 		 * Invalid measurement time, maybe
4152 		 * all on one ack/one send?
4153 		 */
4154 		bytes = 0;
4155 		bytes_ps = 0;
4156 		rack_log_pacing_delay_calc(rack, bytes_ps, reqbytes,
4157 					   0, 0, 0, 10, __LINE__, NULL, quality);
4158 		goto skip_measurement;
4159 	}
4160 	if (rack->r_ctl.rc_gp_lowrtt == 0xffffffff) {
4161 		/* We never made a us_rtt measurement? */
4162 		bytes = 0;
4163 		bytes_ps = 0;
4164 		rack_log_pacing_delay_calc(rack, bytes_ps, reqbytes,
4165 					   0, 0, 0, 10, __LINE__, NULL, quality);
4166 		goto skip_measurement;
4167 	}
4168 	/*
4169 	 * Calculate the maximum possible b/w this connection
4170 	 * could have. We base our calculation on the lowest
4171 	 * rtt we have seen during the measurement and the
4172 	 * largest rwnd the client has given us in that time. This
4173 	 * forms a BDP that is the maximum that we could ever
4174 	 * get to the client. Anything larger is not valid.
4175 	 *
4176 	 * I originally had code here that rejected measurements
4177 	 * where the time was less than 1/2 the latest us_rtt.
4178 	 * But after thinking on that I realized its wrong since
4179 	 * say you had a 150Mbps or even 1Gbps link, and you
4180 	 * were a long way away.. example I am in Europe (100ms rtt)
4181 	 * talking to my 1Gbps link in S.C. Now measuring say 150,000
4182 	 * bytes my time would be 1.2ms, and yet my rtt would say
4183 	 * the measurement was invalid the time was < 50ms. The
4184 	 * same thing is true for 150Mb (8ms of time).
4185 	 *
4186 	 * A better way I realized is to look at what the maximum
4187 	 * the connection could possibly do. This is gated on
4188 	 * the lowest RTT we have seen and the highest rwnd.
4189 	 * We should in theory never exceed that, if we are
4190 	 * then something on the path is storing up packets
4191 	 * and then feeding them all at once to our endpoint
4192 	 * messing up our measurement.
4193 	 */
4194 	rack->r_ctl.last_max_bw = rack->r_ctl.rc_gp_high_rwnd;
4195 	rack->r_ctl.last_max_bw *= HPTS_USEC_IN_SEC;
4196 	rack->r_ctl.last_max_bw /= rack->r_ctl.rc_gp_lowrtt;
4197 	if (SEQ_LT(th_ack, tp->gput_seq)) {
4198 		/* No measurement can be made */
4199 		bytes = 0;
4200 		bytes_ps = 0;
4201 		rack_log_pacing_delay_calc(rack, bytes_ps, reqbytes,
4202 					   0, 0, 0, 10, __LINE__, NULL, quality);
4203 		goto skip_measurement;
4204 	} else
4205 		bytes = (th_ack - tp->gput_seq);
4206 	bytes_ps = (uint64_t)bytes;
4207 	/*
4208 	 * Don't measure a b/w for pacing unless we have gotten at least
4209 	 * an initial windows worth of data in this measurement interval.
4210 	 *
4211 	 * Small numbers of bytes get badly influenced by delayed ack and
4212 	 * other artifacts. Note we take the initial window or our
4213 	 * defined minimum GP (defaulting to 10 which hopefully is the
4214 	 * IW).
4215 	 */
4216 	if (rack->rc_gp_filled == 0) {
4217 		/*
4218 		 * The initial estimate is special. We
4219 		 * have blasted out an IW worth of packets
4220 		 * without a real valid ack ts results. We
4221 		 * then setup the app_limited_needs_set flag,
4222 		 * this should get the first ack in (probably 2
4223 		 * MSS worth) to be recorded as the timestamp.
4224 		 * We thus allow a smaller number of bytes i.e.
4225 		 * IW - 2MSS.
4226 		 */
4227 		reqbytes -= (2 * segsiz);
4228 		/* Also lets fill previous for our first measurement to be neutral */
4229 		rack->r_ctl.rc_prev_gp_srtt = rack->r_ctl.rc_gp_srtt;
4230 	}
4231 	if ((bytes_ps < reqbytes) || rack->app_limited_needs_set) {
4232 		rack_log_pacing_delay_calc(rack, bytes_ps, reqbytes,
4233 					   rack->r_ctl.rc_app_limited_cnt,
4234 					   0, 0, 10, __LINE__, NULL, quality);
4235 		goto skip_measurement;
4236 	}
4237 	/*
4238 	 * We now need to calculate the Timely like status so
4239 	 * we can update (possibly) the b/w multipliers.
4240 	 */
4241 	new_rtt_diff = (int32_t)rack->r_ctl.rc_gp_srtt - (int32_t)rack->r_ctl.rc_prev_gp_srtt;
4242 	if (rack->rc_gp_filled == 0) {
4243 		/* No previous reading */
4244 		rack->r_ctl.rc_rtt_diff = new_rtt_diff;
4245 	} else {
4246 		if (rack->measure_saw_probe_rtt == 0) {
4247 			/*
4248 			 * We don't want a probertt to be counted
4249 			 * since it will be negative incorrectly. We
4250 			 * expect to be reducing the RTT when we
4251 			 * pace at a slower rate.
4252 			 */
4253 			rack->r_ctl.rc_rtt_diff -= (rack->r_ctl.rc_rtt_diff / 8);
4254 			rack->r_ctl.rc_rtt_diff += (new_rtt_diff / 8);
4255 		}
4256 	}
4257 	timely_says = rack_make_timely_judgement(rack,
4258 		rack->r_ctl.rc_gp_srtt,
4259 		rack->r_ctl.rc_rtt_diff,
4260 	        rack->r_ctl.rc_prev_gp_srtt
4261 		);
4262 	bytes_ps *= HPTS_USEC_IN_SEC;
4263 	bytes_ps /= utim;
4264 	if (bytes_ps > rack->r_ctl.last_max_bw) {
4265 		/*
4266 		 * Something is on path playing
4267 		 * since this b/w is not possible based
4268 		 * on our BDP (highest rwnd and lowest rtt
4269 		 * we saw in the measurement window).
4270 		 *
4271 		 * Another option here would be to
4272 		 * instead skip the measurement.
4273 		 */
4274 		rack_log_pacing_delay_calc(rack, bytes, reqbytes,
4275 					   bytes_ps, rack->r_ctl.last_max_bw, 0,
4276 					   11, __LINE__, NULL, quality);
4277 		bytes_ps = rack->r_ctl.last_max_bw;
4278 	}
4279 	/* We store gp for b/w in bytes per second */
4280 	if (rack->rc_gp_filled == 0) {
4281 		/* Initial measurement */
4282 		if (bytes_ps) {
4283 			rack->r_ctl.gp_bw = bytes_ps;
4284 			rack->rc_gp_filled = 1;
4285 			rack->r_ctl.num_measurements = 1;
4286 			rack_set_pace_segments(rack->rc_tp, rack, __LINE__, NULL);
4287 		} else {
4288 			rack_log_pacing_delay_calc(rack, bytes_ps, reqbytes,
4289 						   rack->r_ctl.rc_app_limited_cnt,
4290 						   0, 0, 10, __LINE__, NULL, quality);
4291 		}
4292 		if (tcp_in_hpts(rack->rc_inp) &&
4293 		    (rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT)) {
4294 			/*
4295 			 * Ok we can't trust the pacer in this case
4296 			 * where we transition from un-paced to paced.
4297 			 * Or for that matter when the burst mitigation
4298 			 * was making a wild guess and got it wrong.
4299 			 * Stop the pacer and clear up all the aggregate
4300 			 * delays etc.
4301 			 */
4302 			tcp_hpts_remove(rack->rc_inp);
4303 			rack->r_ctl.rc_hpts_flags = 0;
4304 			rack->r_ctl.rc_last_output_to = 0;
4305 		}
4306 		did_add = 2;
4307 	} else if (rack->r_ctl.num_measurements < RACK_REQ_AVG) {
4308 		/* Still a small number run an average */
4309 		rack->r_ctl.gp_bw += bytes_ps;
4310 		addpart = rack->r_ctl.num_measurements;
4311 		rack->r_ctl.num_measurements++;
4312 		if (rack->r_ctl.num_measurements >= RACK_REQ_AVG) {
4313 			/* We have collected enough to move forward */
4314 			rack->r_ctl.gp_bw /= (uint64_t)rack->r_ctl.num_measurements;
4315 		}
4316 		did_add = 3;
4317 	} else {
4318 		/*
4319 		 * We want to take 1/wma of the goodput and add in to 7/8th
4320 		 * of the old value weighted by the srtt. So if your measurement
4321 		 * period is say 2 SRTT's long you would get 1/4 as the
4322 		 * value, if it was like 1/2 SRTT then you would get 1/16th.
4323 		 *
4324 		 * But we must be careful not to take too much i.e. if the
4325 		 * srtt is say 20ms and the measurement is taken over
4326 		 * 400ms our weight would be 400/20 i.e. 20. On the
4327 		 * other hand if we get a measurement over 1ms with a
4328 		 * 10ms rtt we only want to take a much smaller portion.
4329 		 */
4330 		if (rack->r_ctl.num_measurements < 0xff) {
4331 			rack->r_ctl.num_measurements++;
4332 		}
4333 		srtt = (uint64_t)tp->t_srtt;
4334 		if (srtt == 0) {
4335 			/*
4336 			 * Strange why did t_srtt go back to zero?
4337 			 */
4338 			if (rack->r_ctl.rc_rack_min_rtt)
4339 				srtt = rack->r_ctl.rc_rack_min_rtt;
4340 			else
4341 				srtt = HPTS_USEC_IN_MSEC;
4342 		}
4343 		/*
4344 		 * XXXrrs: Note for reviewers, in playing with
4345 		 * dynamic pacing I discovered this GP calculation
4346 		 * as done originally leads to some undesired results.
4347 		 * Basically you can get longer measurements contributing
4348 		 * too much to the WMA. Thus I changed it if you are doing
4349 		 * dynamic adjustments to only do the aportioned adjustment
4350 		 * if we have a very small (time wise) measurement. Longer
4351 		 * measurements just get there weight (defaulting to 1/8)
4352 		 * add to the WMA. We may want to think about changing
4353 		 * this to always do that for both sides i.e. dynamic
4354 		 * and non-dynamic... but considering lots of folks
4355 		 * were playing with this I did not want to change the
4356 		 * calculation per.se. without your thoughts.. Lawerence?
4357 		 * Peter??
4358 		 */
4359 		if (rack->rc_gp_dyn_mul == 0) {
4360 			subpart = rack->r_ctl.gp_bw * utim;
4361 			subpart /= (srtt * 8);
4362 			if (subpart < (rack->r_ctl.gp_bw / 2)) {
4363 				/*
4364 				 * The b/w update takes no more
4365 				 * away then 1/2 our running total
4366 				 * so factor it in.
4367 				 */
4368 				addpart = bytes_ps * utim;
4369 				addpart /= (srtt * 8);
4370 			} else {
4371 				/*
4372 				 * Don't allow a single measurement
4373 				 * to account for more than 1/2 of the
4374 				 * WMA. This could happen on a retransmission
4375 				 * where utim becomes huge compared to
4376 				 * srtt (multiple retransmissions when using
4377 				 * the sending rate which factors in all the
4378 				 * transmissions from the first one).
4379 				 */
4380 				subpart = rack->r_ctl.gp_bw / 2;
4381 				addpart = bytes_ps / 2;
4382 			}
4383 			resid_bw = rack->r_ctl.gp_bw - subpart;
4384 			rack->r_ctl.gp_bw = resid_bw + addpart;
4385 			did_add = 1;
4386 		} else {
4387 			if ((utim / srtt) <= 1) {
4388 				/*
4389 				 * The b/w update was over a small period
4390 				 * of time. The idea here is to prevent a small
4391 				 * measurement time period from counting
4392 				 * too much. So we scale it based on the
4393 				 * time so it attributes less than 1/rack_wma_divisor
4394 				 * of its measurement.
4395 				 */
4396 				subpart = rack->r_ctl.gp_bw * utim;
4397 				subpart /= (srtt * rack_wma_divisor);
4398 				addpart = bytes_ps * utim;
4399 				addpart /= (srtt * rack_wma_divisor);
4400 			} else {
4401 				/*
4402 				 * The scaled measurement was long
4403 				 * enough so lets just add in the
4404 				 * portion of the measurement i.e. 1/rack_wma_divisor
4405 				 */
4406 				subpart = rack->r_ctl.gp_bw / rack_wma_divisor;
4407 				addpart = bytes_ps / rack_wma_divisor;
4408 			}
4409 			if ((rack->measure_saw_probe_rtt == 0) ||
4410 		            (bytes_ps > rack->r_ctl.gp_bw)) {
4411 				/*
4412 				 * For probe-rtt we only add it in
4413 				 * if its larger, all others we just
4414 				 * add in.
4415 				 */
4416 				did_add = 1;
4417 				resid_bw = rack->r_ctl.gp_bw - subpart;
4418 				rack->r_ctl.gp_bw = resid_bw + addpart;
4419 			}
4420 		}
4421 	}
4422 	if ((rack->gp_ready == 0) &&
4423 	    (rack->r_ctl.num_measurements >= rack->r_ctl.req_measurements)) {
4424 		/* We have enough measurements now */
4425 		rack->gp_ready = 1;
4426 		rack_set_cc_pacing(rack);
4427 		if (rack->defer_options)
4428 			rack_apply_deferred_options(rack);
4429 	}
4430 	rack_log_pacing_delay_calc(rack, subpart, addpart, bytes_ps, stim,
4431 				   rack_get_bw(rack), 22, did_add, NULL, quality);
4432 	/* We do not update any multipliers if we are in or have seen a probe-rtt */
4433 	if ((rack->measure_saw_probe_rtt == 0) && rack->rc_gp_rtt_set)
4434 		rack_update_multiplier(rack, timely_says, bytes_ps,
4435 				       rack->r_ctl.rc_gp_srtt,
4436 				       rack->r_ctl.rc_rtt_diff);
4437 	rack_log_pacing_delay_calc(rack, bytes, tim, bytes_ps, stim,
4438 				   rack_get_bw(rack), 3, line, NULL, quality);
4439 	/* reset the gp srtt and setup the new prev */
4440 	rack->r_ctl.rc_prev_gp_srtt = rack->r_ctl.rc_gp_srtt;
4441 	/* Record the lost count for the next measurement */
4442 	rack->r_ctl.rc_loss_at_start = rack->r_ctl.rc_loss_count;
4443 	/*
4444 	 * We restart our diffs based on the gpsrtt in the
4445 	 * measurement window.
4446 	 */
4447 	rack->rc_gp_rtt_set = 0;
4448 	rack->rc_gp_saw_rec = 0;
4449 	rack->rc_gp_saw_ca = 0;
4450 	rack->rc_gp_saw_ss = 0;
4451 	rack->rc_dragged_bottom = 0;
4452 skip_measurement:
4453 
4454 #ifdef STATS
4455 	stats_voi_update_abs_u32(tp->t_stats, VOI_TCP_GPUT,
4456 				 gput);
4457 	/*
4458 	 * XXXLAS: This is a temporary hack, and should be
4459 	 * chained off VOI_TCP_GPUT when stats(9) grows an
4460 	 * API to deal with chained VOIs.
4461 	 */
4462 	if (tp->t_stats_gput_prev > 0)
4463 		stats_voi_update_abs_s32(tp->t_stats,
4464 					 VOI_TCP_GPUT_ND,
4465 					 ((gput - tp->t_stats_gput_prev) * 100) /
4466 					 tp->t_stats_gput_prev);
4467 #endif
4468 	tp->t_flags &= ~TF_GPUTINPROG;
4469 	tp->t_stats_gput_prev = gput;
4470 	/*
4471 	 * Now are we app limited now and there is space from where we
4472 	 * were to where we want to go?
4473 	 *
4474 	 * We don't do the other case i.e. non-applimited here since
4475 	 * the next send will trigger us picking up the missing data.
4476 	 */
4477 	if (rack->r_ctl.rc_first_appl &&
4478 	    TCPS_HAVEESTABLISHED(tp->t_state) &&
4479 	    rack->r_ctl.rc_app_limited_cnt &&
4480 	    (SEQ_GT(rack->r_ctl.rc_first_appl->r_start, th_ack)) &&
4481 	    ((rack->r_ctl.rc_first_appl->r_end - th_ack) >
4482 	     max(rc_init_window(rack), (MIN_GP_WIN * segsiz)))) {
4483 		/*
4484 		 * Yep there is enough outstanding to make a measurement here.
4485 		 */
4486 		struct rack_sendmap *rsm, fe;
4487 
4488 		rack->r_ctl.rc_gp_lowrtt = 0xffffffff;
4489 		rack->r_ctl.rc_gp_high_rwnd = rack->rc_tp->snd_wnd;
4490 		tp->gput_ts = tcp_tv_to_usectick(&rack->r_ctl.act_rcv_time);
4491 		rack->app_limited_needs_set = 0;
4492 		tp->gput_seq = th_ack;
4493 		if (rack->in_probe_rtt)
4494 			rack->measure_saw_probe_rtt = 1;
4495 		else if ((rack->measure_saw_probe_rtt) &&
4496 			 (SEQ_GEQ(tp->gput_seq, rack->r_ctl.rc_probertt_sndmax_atexit)))
4497 			rack->measure_saw_probe_rtt = 0;
4498 		if ((rack->r_ctl.rc_first_appl->r_end - th_ack) >= rack_get_measure_window(tp, rack)) {
4499 			/* There is a full window to gain info from */
4500 			tp->gput_ack = tp->gput_seq + rack_get_measure_window(tp, rack);
4501 		} else {
4502 			/* We can only measure up to the applimited point */
4503 			tp->gput_ack = tp->gput_seq + (rack->r_ctl.rc_first_appl->r_end - th_ack);
4504 			if ((tp->gput_ack - tp->gput_seq) < (MIN_GP_WIN * segsiz)) {
4505 				/*
4506 				 * We don't have enough to make a measurement.
4507 				 */
4508 				tp->t_flags &= ~TF_GPUTINPROG;
4509 				rack_log_pacing_delay_calc(rack, tp->gput_ack, tp->gput_seq,
4510 							   0, 0, 0, 6, __LINE__, NULL, quality);
4511 				return;
4512 			}
4513 		}
4514 		if (tp->t_state >= TCPS_FIN_WAIT_1) {
4515 			/*
4516 			 * We will get no more data into the SB
4517 			 * this means we need to have the data available
4518 			 * before we start a measurement.
4519 			 */
4520 			if (sbavail(&tp->t_inpcb->inp_socket->so_snd) < (tp->gput_ack - tp->gput_seq)) {
4521 				/* Nope not enough data. */
4522 				return;
4523 			}
4524 		}
4525 		tp->t_flags |= TF_GPUTINPROG;
4526 		/*
4527 		 * Now we need to find the timestamp of the send at tp->gput_seq
4528 		 * for the send based measurement.
4529 		 */
4530 		fe.r_start = tp->gput_seq;
4531 		rsm = RB_FIND(rack_rb_tree_head, &rack->r_ctl.rc_mtree, &fe);
4532 		if (rsm) {
4533 			/* Ok send-based limit is set */
4534 			if (SEQ_LT(rsm->r_start, tp->gput_seq)) {
4535 				/*
4536 				 * Move back to include the earlier part
4537 				 * so our ack time lines up right (this may
4538 				 * make an overlapping measurement but thats
4539 				 * ok).
4540 				 */
4541 				tp->gput_seq = rsm->r_start;
4542 			}
4543 			if (rsm->r_flags & RACK_ACKED)
4544 				tp->gput_ts = (uint32_t)rsm->r_ack_arrival;
4545 			else
4546 				rack->app_limited_needs_set = 1;
4547 			rack->r_ctl.rc_gp_output_ts = rsm->r_tim_lastsent[(rsm->r_rtr_cnt-1)];
4548 		} else {
4549 			/*
4550 			 * If we don't find the rsm due to some
4551 			 * send-limit set the current time, which
4552 			 * basically disables the send-limit.
4553 			 */
4554 			struct timeval tv;
4555 
4556 			microuptime(&tv);
4557 			rack->r_ctl.rc_gp_output_ts = rack_to_usec_ts(&tv);
4558 		}
4559 		rack_log_pacing_delay_calc(rack,
4560 					   tp->gput_seq,
4561 					   tp->gput_ack,
4562 					   (uint64_t)rsm,
4563 					   tp->gput_ts,
4564 					   rack->r_ctl.rc_app_limited_cnt,
4565 					   9,
4566 					   __LINE__, NULL, quality);
4567 	}
4568 }
4569 
4570 /*
4571  * CC wrapper hook functions
4572  */
4573 static void
4574 rack_ack_received(struct tcpcb *tp, struct tcp_rack *rack, uint32_t th_ack, uint16_t nsegs,
4575     uint16_t type, int32_t recovery)
4576 {
4577 	uint32_t prior_cwnd, acked;
4578 	struct tcp_log_buffer *lgb = NULL;
4579 	uint8_t labc_to_use, quality;
4580 
4581 	INP_WLOCK_ASSERT(tp->t_inpcb);
4582 	tp->ccv->nsegs = nsegs;
4583 	acked = tp->ccv->bytes_this_ack = (th_ack - tp->snd_una);
4584 	if ((recovery) && (rack->r_ctl.rc_early_recovery_segs)) {
4585 		uint32_t max;
4586 
4587 		max = rack->r_ctl.rc_early_recovery_segs * ctf_fixed_maxseg(tp);
4588 		if (tp->ccv->bytes_this_ack > max) {
4589 			tp->ccv->bytes_this_ack = max;
4590 		}
4591 	}
4592 #ifdef STATS
4593 	stats_voi_update_abs_s32(tp->t_stats, VOI_TCP_CALCFRWINDIFF,
4594 	    ((int32_t)rack->r_ctl.cwnd_to_use) - tp->snd_wnd);
4595 #endif
4596 	quality = RACK_QUALITY_NONE;
4597 	if ((tp->t_flags & TF_GPUTINPROG) &&
4598 	    rack_enough_for_measurement(tp, rack, th_ack, &quality)) {
4599 		/* Measure the Goodput */
4600 		rack_do_goodput_measurement(tp, rack, th_ack, __LINE__, quality);
4601 #ifdef NETFLIX_PEAKRATE
4602 		if ((type == CC_ACK) &&
4603 		    (tp->t_maxpeakrate)) {
4604 			/*
4605 			 * We update t_peakrate_thr. This gives us roughly
4606 			 * one update per round trip time. Note
4607 			 * it will only be used if pace_always is off i.e
4608 			 * we don't do this for paced flows.
4609 			 */
4610 			rack_update_peakrate_thr(tp);
4611 		}
4612 #endif
4613 	}
4614 	/* Which way our we limited, if not cwnd limited no advance in CA */
4615 	if (tp->snd_cwnd <= tp->snd_wnd)
4616 		tp->ccv->flags |= CCF_CWND_LIMITED;
4617 	else
4618 		tp->ccv->flags &= ~CCF_CWND_LIMITED;
4619 	if (tp->snd_cwnd > tp->snd_ssthresh) {
4620 		tp->t_bytes_acked += min(tp->ccv->bytes_this_ack,
4621 			 nsegs * V_tcp_abc_l_var * ctf_fixed_maxseg(tp));
4622 		/* For the setting of a window past use the actual scwnd we are using */
4623 		if (tp->t_bytes_acked >= rack->r_ctl.cwnd_to_use) {
4624 			tp->t_bytes_acked -= rack->r_ctl.cwnd_to_use;
4625 			tp->ccv->flags |= CCF_ABC_SENTAWND;
4626 		}
4627 	} else {
4628 		tp->ccv->flags &= ~CCF_ABC_SENTAWND;
4629 		tp->t_bytes_acked = 0;
4630 	}
4631 	prior_cwnd = tp->snd_cwnd;
4632 	if ((recovery == 0) || (rack_max_abc_post_recovery == 0) || rack->r_use_labc_for_rec ||
4633 	    (rack_client_low_buf && (rack->client_bufferlvl < rack_client_low_buf)))
4634 		labc_to_use = rack->rc_labc;
4635 	else
4636 		labc_to_use = rack_max_abc_post_recovery;
4637 	if (rack_verbose_logging && (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF)) {
4638 		union tcp_log_stackspecific log;
4639 		struct timeval tv;
4640 
4641 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
4642 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
4643 		log.u_bbr.flex1 = th_ack;
4644 		log.u_bbr.flex2 = tp->ccv->flags;
4645 		log.u_bbr.flex3 = tp->ccv->bytes_this_ack;
4646 		log.u_bbr.flex4 = tp->ccv->nsegs;
4647 		log.u_bbr.flex5 = labc_to_use;
4648 		log.u_bbr.flex6 = prior_cwnd;
4649 		log.u_bbr.flex7 = V_tcp_do_newsack;
4650 		log.u_bbr.flex8 = 1;
4651 		lgb = tcp_log_event_(tp, NULL, NULL, NULL, BBR_LOG_CWND, 0,
4652 				     0, &log, false, NULL, NULL, 0, &tv);
4653 	}
4654 	if (CC_ALGO(tp)->ack_received != NULL) {
4655 		/* XXXLAS: Find a way to live without this */
4656 		tp->ccv->curack = th_ack;
4657 		tp->ccv->labc = labc_to_use;
4658 		tp->ccv->flags |= CCF_USE_LOCAL_ABC;
4659 		CC_ALGO(tp)->ack_received(tp->ccv, type);
4660 	}
4661 	if (lgb) {
4662 		lgb->tlb_stackinfo.u_bbr.flex6 = tp->snd_cwnd;
4663 	}
4664 	if (rack->r_must_retran) {
4665 		if (SEQ_GEQ(th_ack, rack->r_ctl.rc_snd_max_at_rto)) {
4666 			/*
4667 			 * We now are beyond the rxt point so lets disable
4668 			 * the flag.
4669 			 */
4670 			rack->r_ctl.rc_out_at_rto = 0;
4671 			rack->r_must_retran = 0;
4672 		} else if ((prior_cwnd + ctf_fixed_maxseg(tp)) <= tp->snd_cwnd) {
4673 			/*
4674 			 * Only decrement the rc_out_at_rto if the cwnd advances
4675 			 * at least a whole segment. Otherwise next time the peer
4676 			 * acks, we won't be able to send this generaly happens
4677 			 * when we are in Congestion Avoidance.
4678 			 */
4679 			if (acked <= rack->r_ctl.rc_out_at_rto){
4680 				rack->r_ctl.rc_out_at_rto -= acked;
4681 			} else {
4682 				rack->r_ctl.rc_out_at_rto = 0;
4683 			}
4684 		}
4685 	}
4686 #ifdef STATS
4687 	stats_voi_update_abs_ulong(tp->t_stats, VOI_TCP_LCWIN, rack->r_ctl.cwnd_to_use);
4688 #endif
4689 	if (rack->r_ctl.rc_rack_largest_cwnd < rack->r_ctl.cwnd_to_use) {
4690 		rack->r_ctl.rc_rack_largest_cwnd = rack->r_ctl.cwnd_to_use;
4691 	}
4692 #ifdef NETFLIX_PEAKRATE
4693 	/* we enforce max peak rate if it is set and we are not pacing */
4694 	if ((rack->rc_always_pace == 0) &&
4695 	    tp->t_peakrate_thr &&
4696 	    (tp->snd_cwnd > tp->t_peakrate_thr)) {
4697 		tp->snd_cwnd = tp->t_peakrate_thr;
4698 	}
4699 #endif
4700 }
4701 
4702 static void
4703 tcp_rack_partialack(struct tcpcb *tp)
4704 {
4705 	struct tcp_rack *rack;
4706 
4707 	rack = (struct tcp_rack *)tp->t_fb_ptr;
4708 	INP_WLOCK_ASSERT(tp->t_inpcb);
4709 	/*
4710 	 * If we are doing PRR and have enough
4711 	 * room to send <or> we are pacing and prr
4712 	 * is disabled we will want to see if we
4713 	 * can send data (by setting r_wanted_output to
4714 	 * true).
4715 	 */
4716 	if ((rack->r_ctl.rc_prr_sndcnt > 0) ||
4717 	    rack->rack_no_prr)
4718 		rack->r_wanted_output = 1;
4719 }
4720 
4721 static void
4722 rack_post_recovery(struct tcpcb *tp, uint32_t th_ack)
4723 {
4724 	struct tcp_rack *rack;
4725 	uint32_t orig_cwnd;
4726 
4727 	orig_cwnd = tp->snd_cwnd;
4728 	INP_WLOCK_ASSERT(tp->t_inpcb);
4729 	rack = (struct tcp_rack *)tp->t_fb_ptr;
4730 	/* only alert CC if we alerted when we entered */
4731 	if (CC_ALGO(tp)->post_recovery != NULL) {
4732 		tp->ccv->curack = th_ack;
4733 		CC_ALGO(tp)->post_recovery(tp->ccv);
4734 		if (tp->snd_cwnd < tp->snd_ssthresh) {
4735 			/*
4736 			 * Rack has burst control and pacing
4737 			 * so lets not set this any lower than
4738 			 * snd_ssthresh per RFC-6582 (option 2).
4739 			 */
4740 			tp->snd_cwnd = tp->snd_ssthresh;
4741 		}
4742 	}
4743 	if (rack_verbose_logging && (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF)) {
4744 		union tcp_log_stackspecific log;
4745 		struct timeval tv;
4746 
4747 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
4748 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
4749 		log.u_bbr.flex1 = th_ack;
4750 		log.u_bbr.flex2 = tp->ccv->flags;
4751 		log.u_bbr.flex3 = tp->ccv->bytes_this_ack;
4752 		log.u_bbr.flex4 = tp->ccv->nsegs;
4753 		log.u_bbr.flex5 = V_tcp_abc_l_var;
4754 		log.u_bbr.flex6 = orig_cwnd;
4755 		log.u_bbr.flex7 = V_tcp_do_newsack;
4756 		log.u_bbr.pkts_out = rack->r_ctl.rc_prr_sndcnt;
4757 		log.u_bbr.flex8 = 2;
4758 		tcp_log_event_(tp, NULL, NULL, NULL, BBR_LOG_CWND, 0,
4759 			       0, &log, false, NULL, NULL, 0, &tv);
4760 	}
4761 	if ((rack->rack_no_prr == 0) &&
4762 	    (rack->no_prr_addback == 0) &&
4763 	    (rack->r_ctl.rc_prr_sndcnt > 0)) {
4764 		/*
4765 		 * Suck the next prr cnt back into cwnd, but
4766 		 * only do that if we are not application limited.
4767 		 */
4768 		if (ctf_outstanding(tp) <= sbavail(&(tp->t_inpcb->inp_socket->so_snd))) {
4769 			/*
4770 			 * We are allowed to add back to the cwnd the amount we did
4771 			 * not get out if:
4772 			 * a) no_prr_addback is off.
4773 			 * b) we are not app limited
4774 			 * c) we are doing prr
4775 			 * <and>
4776 			 * d) it is bounded by rack_prr_addbackmax (if addback is 0, then none).
4777 			 */
4778 			tp->snd_cwnd += min((ctf_fixed_maxseg(tp) * rack_prr_addbackmax),
4779 					    rack->r_ctl.rc_prr_sndcnt);
4780 		}
4781 		rack->r_ctl.rc_prr_sndcnt = 0;
4782 		rack_log_to_prr(rack, 1, 0, __LINE__);
4783 	}
4784 	rack_log_to_prr(rack, 14, orig_cwnd, __LINE__);
4785 	tp->snd_recover = tp->snd_una;
4786 	if (rack->r_ctl.dsack_persist) {
4787 		rack->r_ctl.dsack_persist--;
4788 		if (rack->r_ctl.num_dsack && (rack->r_ctl.dsack_persist == 0)) {
4789 			rack->r_ctl.num_dsack = 0;
4790 		}
4791 		rack_log_dsack_event(rack, 1, __LINE__, 0, 0);
4792 	}
4793 	EXIT_RECOVERY(tp->t_flags);
4794 }
4795 
4796 static void
4797 rack_cong_signal(struct tcpcb *tp, uint32_t type, uint32_t ack, int line)
4798 {
4799 	struct tcp_rack *rack;
4800 	uint32_t ssthresh_enter, cwnd_enter, in_rec_at_entry, orig_cwnd;
4801 
4802 	INP_WLOCK_ASSERT(tp->t_inpcb);
4803 #ifdef STATS
4804 	stats_voi_update_abs_u32(tp->t_stats, VOI_TCP_CSIG, type);
4805 #endif
4806 	if (IN_RECOVERY(tp->t_flags) == 0) {
4807 		in_rec_at_entry = 0;
4808 		ssthresh_enter = tp->snd_ssthresh;
4809 		cwnd_enter = tp->snd_cwnd;
4810 	} else
4811 		in_rec_at_entry = 1;
4812 	rack = (struct tcp_rack *)tp->t_fb_ptr;
4813 	switch (type) {
4814 	case CC_NDUPACK:
4815 		tp->t_flags &= ~TF_WASFRECOVERY;
4816 		tp->t_flags &= ~TF_WASCRECOVERY;
4817 		if (!IN_FASTRECOVERY(tp->t_flags)) {
4818 			rack->r_ctl.rc_prr_delivered = 0;
4819 			rack->r_ctl.rc_prr_out = 0;
4820 			if (rack->rack_no_prr == 0) {
4821 				rack->r_ctl.rc_prr_sndcnt = ctf_fixed_maxseg(tp);
4822 				rack_log_to_prr(rack, 2, in_rec_at_entry, line);
4823 			}
4824 			rack->r_ctl.rc_prr_recovery_fs = tp->snd_max - tp->snd_una;
4825 			tp->snd_recover = tp->snd_max;
4826 			if (tp->t_flags2 & TF2_ECN_PERMIT)
4827 				tp->t_flags2 |= TF2_ECN_SND_CWR;
4828 		}
4829 		break;
4830 	case CC_ECN:
4831 		if (!IN_CONGRECOVERY(tp->t_flags) ||
4832 		    /*
4833 		     * Allow ECN reaction on ACK to CWR, if
4834 		     * that data segment was also CE marked.
4835 		     */
4836 		    SEQ_GEQ(ack, tp->snd_recover)) {
4837 			EXIT_CONGRECOVERY(tp->t_flags);
4838 			KMOD_TCPSTAT_INC(tcps_ecn_rcwnd);
4839 			tp->snd_recover = tp->snd_max + 1;
4840 			if (tp->t_flags2 & TF2_ECN_PERMIT)
4841 				tp->t_flags2 |= TF2_ECN_SND_CWR;
4842 		}
4843 		break;
4844 	case CC_RTO:
4845 		tp->t_dupacks = 0;
4846 		tp->t_bytes_acked = 0;
4847 		EXIT_RECOVERY(tp->t_flags);
4848 		tp->snd_ssthresh = max(2, min(tp->snd_wnd, rack->r_ctl.cwnd_to_use) / 2 /
4849 		    ctf_fixed_maxseg(tp)) * ctf_fixed_maxseg(tp);
4850 		orig_cwnd = tp->snd_cwnd;
4851 		tp->snd_cwnd = ctf_fixed_maxseg(tp);
4852 		rack_log_to_prr(rack, 16, orig_cwnd, line);
4853 		if (tp->t_flags2 & TF2_ECN_PERMIT)
4854 			tp->t_flags2 |= TF2_ECN_SND_CWR;
4855 		break;
4856 	case CC_RTO_ERR:
4857 		KMOD_TCPSTAT_INC(tcps_sndrexmitbad);
4858 		/* RTO was unnecessary, so reset everything. */
4859 		tp->snd_cwnd = tp->snd_cwnd_prev;
4860 		tp->snd_ssthresh = tp->snd_ssthresh_prev;
4861 		tp->snd_recover = tp->snd_recover_prev;
4862 		if (tp->t_flags & TF_WASFRECOVERY) {
4863 			ENTER_FASTRECOVERY(tp->t_flags);
4864 			tp->t_flags &= ~TF_WASFRECOVERY;
4865 		}
4866 		if (tp->t_flags & TF_WASCRECOVERY) {
4867 			ENTER_CONGRECOVERY(tp->t_flags);
4868 			tp->t_flags &= ~TF_WASCRECOVERY;
4869 		}
4870 		tp->snd_nxt = tp->snd_max;
4871 		tp->t_badrxtwin = 0;
4872 		break;
4873 	}
4874 	if ((CC_ALGO(tp)->cong_signal != NULL)  &&
4875 	    (type != CC_RTO)){
4876 		tp->ccv->curack = ack;
4877 		CC_ALGO(tp)->cong_signal(tp->ccv, type);
4878 	}
4879 	if ((in_rec_at_entry == 0) && IN_RECOVERY(tp->t_flags)) {
4880 		rack_log_to_prr(rack, 15, cwnd_enter, line);
4881 		rack->r_ctl.dsack_byte_cnt = 0;
4882 		rack->r_ctl.retran_during_recovery = 0;
4883 		rack->r_ctl.rc_cwnd_at_erec = cwnd_enter;
4884 		rack->r_ctl.rc_ssthresh_at_erec = ssthresh_enter;
4885 		rack->r_ent_rec_ns = 1;
4886 	}
4887 }
4888 
4889 static inline void
4890 rack_cc_after_idle(struct tcp_rack *rack, struct tcpcb *tp)
4891 {
4892 	uint32_t i_cwnd;
4893 
4894 	INP_WLOCK_ASSERT(tp->t_inpcb);
4895 
4896 #ifdef NETFLIX_STATS
4897 	KMOD_TCPSTAT_INC(tcps_idle_restarts);
4898 	if (tp->t_state == TCPS_ESTABLISHED)
4899 		KMOD_TCPSTAT_INC(tcps_idle_estrestarts);
4900 #endif
4901 	if (CC_ALGO(tp)->after_idle != NULL)
4902 		CC_ALGO(tp)->after_idle(tp->ccv);
4903 
4904 	if (tp->snd_cwnd == 1)
4905 		i_cwnd = tp->t_maxseg;		/* SYN(-ACK) lost */
4906 	else
4907 		i_cwnd = rc_init_window(rack);
4908 
4909 	/*
4910 	 * Being idle is no different than the initial window. If the cc
4911 	 * clamps it down below the initial window raise it to the initial
4912 	 * window.
4913 	 */
4914 	if (tp->snd_cwnd < i_cwnd) {
4915 		tp->snd_cwnd = i_cwnd;
4916 	}
4917 }
4918 
4919 /*
4920  * Indicate whether this ack should be delayed.  We can delay the ack if
4921  * following conditions are met:
4922  *	- There is no delayed ack timer in progress.
4923  *	- Our last ack wasn't a 0-sized window. We never want to delay
4924  *	  the ack that opens up a 0-sized window.
4925  *	- LRO wasn't used for this segment. We make sure by checking that the
4926  *	  segment size is not larger than the MSS.
4927  *	- Delayed acks are enabled or this is a half-synchronized T/TCP
4928  *	  connection.
4929  */
4930 #define DELAY_ACK(tp, tlen)			 \
4931 	(((tp->t_flags & TF_RXWIN0SENT) == 0) && \
4932 	((tp->t_flags & TF_DELACK) == 0) &&	 \
4933 	(tlen <= tp->t_maxseg) &&		 \
4934 	(tp->t_delayed_ack || (tp->t_flags & TF_NEEDSYN)))
4935 
4936 static struct rack_sendmap *
4937 rack_find_lowest_rsm(struct tcp_rack *rack)
4938 {
4939 	struct rack_sendmap *rsm;
4940 
4941 	/*
4942 	 * Walk the time-order transmitted list looking for an rsm that is
4943 	 * not acked. This will be the one that was sent the longest time
4944 	 * ago that is still outstanding.
4945 	 */
4946 	TAILQ_FOREACH(rsm, &rack->r_ctl.rc_tmap, r_tnext) {
4947 		if (rsm->r_flags & RACK_ACKED) {
4948 			continue;
4949 		}
4950 		goto finish;
4951 	}
4952 finish:
4953 	return (rsm);
4954 }
4955 
4956 static struct rack_sendmap *
4957 rack_find_high_nonack(struct tcp_rack *rack, struct rack_sendmap *rsm)
4958 {
4959 	struct rack_sendmap *prsm;
4960 
4961 	/*
4962 	 * Walk the sequence order list backward until we hit and arrive at
4963 	 * the highest seq not acked. In theory when this is called it
4964 	 * should be the last segment (which it was not).
4965 	 */
4966 	prsm = rsm;
4967 	RB_FOREACH_REVERSE_FROM(prsm, rack_rb_tree_head, rsm) {
4968 		if (prsm->r_flags & (RACK_ACKED | RACK_HAS_FIN)) {
4969 			continue;
4970 		}
4971 		return (prsm);
4972 	}
4973 	return (NULL);
4974 }
4975 
4976 static uint32_t
4977 rack_calc_thresh_rack(struct tcp_rack *rack, uint32_t srtt, uint32_t cts)
4978 {
4979 	int32_t lro;
4980 	uint32_t thresh;
4981 
4982 	/*
4983 	 * lro is the flag we use to determine if we have seen reordering.
4984 	 * If it gets set we have seen reordering. The reorder logic either
4985 	 * works in one of two ways:
4986 	 *
4987 	 * If reorder-fade is configured, then we track the last time we saw
4988 	 * re-ordering occur. If we reach the point where enough time as
4989 	 * passed we no longer consider reordering has occuring.
4990 	 *
4991 	 * Or if reorder-face is 0, then once we see reordering we consider
4992 	 * the connection to alway be subject to reordering and just set lro
4993 	 * to 1.
4994 	 *
4995 	 * In the end if lro is non-zero we add the extra time for
4996 	 * reordering in.
4997 	 */
4998 	if (srtt == 0)
4999 		srtt = 1;
5000 	if (rack->r_ctl.rc_reorder_ts) {
5001 		if (rack->r_ctl.rc_reorder_fade) {
5002 			if (SEQ_GEQ(cts, rack->r_ctl.rc_reorder_ts)) {
5003 				lro = cts - rack->r_ctl.rc_reorder_ts;
5004 				if (lro == 0) {
5005 					/*
5006 					 * No time as passed since the last
5007 					 * reorder, mark it as reordering.
5008 					 */
5009 					lro = 1;
5010 				}
5011 			} else {
5012 				/* Negative time? */
5013 				lro = 0;
5014 			}
5015 			if (lro > rack->r_ctl.rc_reorder_fade) {
5016 				/* Turn off reordering seen too */
5017 				rack->r_ctl.rc_reorder_ts = 0;
5018 				lro = 0;
5019 			}
5020 		} else {
5021 			/* Reodering does not fade */
5022 			lro = 1;
5023 		}
5024 	} else {
5025 		lro = 0;
5026 	}
5027 	if (rack->rc_rack_tmr_std_based == 0) {
5028 		thresh = srtt + rack->r_ctl.rc_pkt_delay;
5029 	} else {
5030 		/* Standards based pkt-delay is 1/4 srtt */
5031 		thresh = srtt +  (srtt >> 2);
5032 	}
5033 	if (lro && (rack->rc_rack_tmr_std_based == 0)) {
5034 		/* It must be set, if not you get 1/4 rtt */
5035 		if (rack->r_ctl.rc_reorder_shift)
5036 			thresh += (srtt >> rack->r_ctl.rc_reorder_shift);
5037 		else
5038 			thresh += (srtt >> 2);
5039 	}
5040 	if (rack->rc_rack_use_dsack &&
5041 	    lro &&
5042 	    (rack->r_ctl.num_dsack > 0)) {
5043 		/*
5044 		 * We only increase the reordering window if we
5045 		 * have seen reordering <and> we have a DSACK count.
5046 		 */
5047 		thresh += rack->r_ctl.num_dsack * (srtt >> 2);
5048 		rack_log_dsack_event(rack, 4, __LINE__, srtt, thresh);
5049 	}
5050 	/* SRTT * 2 is the ceiling */
5051 	if (thresh > (srtt * 2)) {
5052 		thresh = srtt * 2;
5053 	}
5054 	/* And we don't want it above the RTO max either */
5055 	if (thresh > rack_rto_max) {
5056 		thresh = rack_rto_max;
5057 	}
5058 	rack_log_dsack_event(rack, 6, __LINE__, srtt, thresh);
5059 	return (thresh);
5060 }
5061 
5062 static uint32_t
5063 rack_calc_thresh_tlp(struct tcpcb *tp, struct tcp_rack *rack,
5064 		     struct rack_sendmap *rsm, uint32_t srtt)
5065 {
5066 	struct rack_sendmap *prsm;
5067 	uint32_t thresh, len;
5068 	int segsiz;
5069 
5070 	if (srtt == 0)
5071 		srtt = 1;
5072 	if (rack->r_ctl.rc_tlp_threshold)
5073 		thresh = srtt + (srtt / rack->r_ctl.rc_tlp_threshold);
5074 	else
5075 		thresh = (srtt * 2);
5076 
5077 	/* Get the previous sent packet, if any */
5078 	segsiz = min(ctf_fixed_maxseg(tp), rack->r_ctl.rc_pace_min_segs);
5079 	len = rsm->r_end - rsm->r_start;
5080 	if (rack->rack_tlp_threshold_use == TLP_USE_ID) {
5081 		/* Exactly like the ID */
5082 		if (((tp->snd_max - tp->snd_una) - rack->r_ctl.rc_sacked + rack->r_ctl.rc_holes_rxt) <= segsiz) {
5083 			uint32_t alt_thresh;
5084 			/*
5085 			 * Compensate for delayed-ack with the d-ack time.
5086 			 */
5087 			alt_thresh = srtt + (srtt / 2) + rack_delayed_ack_time;
5088 			if (alt_thresh > thresh)
5089 				thresh = alt_thresh;
5090 		}
5091 	} else if (rack->rack_tlp_threshold_use == TLP_USE_TWO_ONE) {
5092 		/* 2.1 behavior */
5093 		prsm = TAILQ_PREV(rsm, rack_head, r_tnext);
5094 		if (prsm && (len <= segsiz)) {
5095 			/*
5096 			 * Two packets outstanding, thresh should be (2*srtt) +
5097 			 * possible inter-packet delay (if any).
5098 			 */
5099 			uint32_t inter_gap = 0;
5100 			int idx, nidx;
5101 
5102 			idx = rsm->r_rtr_cnt - 1;
5103 			nidx = prsm->r_rtr_cnt - 1;
5104 			if (rsm->r_tim_lastsent[nidx] >= prsm->r_tim_lastsent[idx]) {
5105 				/* Yes it was sent later (or at the same time) */
5106 				inter_gap = rsm->r_tim_lastsent[idx] - prsm->r_tim_lastsent[nidx];
5107 			}
5108 			thresh += inter_gap;
5109 		} else if (len <= segsiz) {
5110 			/*
5111 			 * Possibly compensate for delayed-ack.
5112 			 */
5113 			uint32_t alt_thresh;
5114 
5115 			alt_thresh = srtt + (srtt / 2) + rack_delayed_ack_time;
5116 			if (alt_thresh > thresh)
5117 				thresh = alt_thresh;
5118 		}
5119 	} else if (rack->rack_tlp_threshold_use == TLP_USE_TWO_TWO) {
5120 		/* 2.2 behavior */
5121 		if (len <= segsiz) {
5122 			uint32_t alt_thresh;
5123 			/*
5124 			 * Compensate for delayed-ack with the d-ack time.
5125 			 */
5126 			alt_thresh = srtt + (srtt / 2) + rack_delayed_ack_time;
5127 			if (alt_thresh > thresh)
5128 				thresh = alt_thresh;
5129 		}
5130 	}
5131 	/* Not above an RTO */
5132 	if (thresh > tp->t_rxtcur) {
5133 		thresh = tp->t_rxtcur;
5134 	}
5135 	/* Not above a RTO max */
5136 	if (thresh > rack_rto_max) {
5137 		thresh = rack_rto_max;
5138 	}
5139 	/* Apply user supplied min TLP */
5140 	if (thresh < rack_tlp_min) {
5141 		thresh = rack_tlp_min;
5142 	}
5143 	return (thresh);
5144 }
5145 
5146 static uint32_t
5147 rack_grab_rtt(struct tcpcb *tp, struct tcp_rack *rack)
5148 {
5149 	/*
5150 	 * We want the rack_rtt which is the
5151 	 * last rtt we measured. However if that
5152 	 * does not exist we fallback to the srtt (which
5153 	 * we probably will never do) and then as a last
5154 	 * resort we use RACK_INITIAL_RTO if no srtt is
5155 	 * yet set.
5156 	 */
5157 	if (rack->rc_rack_rtt)
5158 		return (rack->rc_rack_rtt);
5159 	else if (tp->t_srtt == 0)
5160 		return (RACK_INITIAL_RTO);
5161 	return (tp->t_srtt);
5162 }
5163 
5164 static struct rack_sendmap *
5165 rack_check_recovery_mode(struct tcpcb *tp, uint32_t tsused)
5166 {
5167 	/*
5168 	 * Check to see that we don't need to fall into recovery. We will
5169 	 * need to do so if our oldest transmit is past the time we should
5170 	 * have had an ack.
5171 	 */
5172 	struct tcp_rack *rack;
5173 	struct rack_sendmap *rsm;
5174 	int32_t idx;
5175 	uint32_t srtt, thresh;
5176 
5177 	rack = (struct tcp_rack *)tp->t_fb_ptr;
5178 	if (RB_EMPTY(&rack->r_ctl.rc_mtree)) {
5179 		return (NULL);
5180 	}
5181 	rsm = TAILQ_FIRST(&rack->r_ctl.rc_tmap);
5182 	if (rsm == NULL)
5183 		return (NULL);
5184 
5185 
5186 	if (rsm->r_flags & RACK_ACKED) {
5187 		rsm = rack_find_lowest_rsm(rack);
5188 		if (rsm == NULL)
5189 			return (NULL);
5190 	}
5191 	idx = rsm->r_rtr_cnt - 1;
5192 	srtt = rack_grab_rtt(tp, rack);
5193 	thresh = rack_calc_thresh_rack(rack, srtt, tsused);
5194 	if (TSTMP_LT(tsused, ((uint32_t)rsm->r_tim_lastsent[idx]))) {
5195 		return (NULL);
5196 	}
5197 	if ((tsused - ((uint32_t)rsm->r_tim_lastsent[idx])) < thresh) {
5198 		return (NULL);
5199 	}
5200 	/* Ok if we reach here we are over-due and this guy can be sent */
5201 	rack_cong_signal(tp, CC_NDUPACK, tp->snd_una, __LINE__);
5202 	return (rsm);
5203 }
5204 
5205 static uint32_t
5206 rack_get_persists_timer_val(struct tcpcb *tp, struct tcp_rack *rack)
5207 {
5208 	int32_t t;
5209 	int32_t tt;
5210 	uint32_t ret_val;
5211 
5212 	t = (tp->t_srtt + (tp->t_rttvar << 2));
5213 	RACK_TCPT_RANGESET(tt, t * tcp_backoff[tp->t_rxtshift],
5214  	    rack_persist_min, rack_persist_max, rack->r_ctl.timer_slop);
5215 	rack->r_ctl.rc_hpts_flags |= PACE_TMR_PERSIT;
5216 	ret_val = (uint32_t)tt;
5217 	return (ret_val);
5218 }
5219 
5220 static uint32_t
5221 rack_timer_start(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cts, int sup_rack)
5222 {
5223 	/*
5224 	 * Start the FR timer, we do this based on getting the first one in
5225 	 * the rc_tmap. Note that if its NULL we must stop the timer. in all
5226 	 * events we need to stop the running timer (if its running) before
5227 	 * starting the new one.
5228 	 */
5229 	uint32_t thresh, exp, to, srtt, time_since_sent, tstmp_touse;
5230 	uint32_t srtt_cur;
5231 	int32_t idx;
5232 	int32_t is_tlp_timer = 0;
5233 	struct rack_sendmap *rsm;
5234 
5235 	if (rack->t_timers_stopped) {
5236 		/* All timers have been stopped none are to run */
5237 		return (0);
5238 	}
5239 	if (rack->rc_in_persist) {
5240 		/* We can't start any timer in persists */
5241 		return (rack_get_persists_timer_val(tp, rack));
5242 	}
5243 	rack->rc_on_min_to = 0;
5244 	if ((tp->t_state < TCPS_ESTABLISHED) ||
5245 	    ((tp->t_flags & TF_SACK_PERMIT) == 0)) {
5246 		goto activate_rxt;
5247 	}
5248 	rsm = TAILQ_FIRST(&rack->r_ctl.rc_tmap);
5249 	if ((rsm == NULL) || sup_rack) {
5250 		/* Nothing on the send map or no rack */
5251 activate_rxt:
5252 		time_since_sent = 0;
5253 		rsm = TAILQ_FIRST(&rack->r_ctl.rc_tmap);
5254 		if (rsm) {
5255 			/*
5256 			 * Should we discount the RTX timer any?
5257 			 *
5258 			 * We want to discount it the smallest amount.
5259 			 * If a timer (Rack/TLP or RXT) has gone off more
5260 			 * recently thats the discount we want to use (now - timer time).
5261 			 * If the retransmit of the oldest packet was more recent then
5262 			 * we want to use that (now - oldest-packet-last_transmit_time).
5263 			 *
5264 			 */
5265 			idx = rsm->r_rtr_cnt - 1;
5266 			if (TSTMP_GEQ(rack->r_ctl.rc_tlp_rxt_last_time, ((uint32_t)rsm->r_tim_lastsent[idx])))
5267 				tstmp_touse = (uint32_t)rack->r_ctl.rc_tlp_rxt_last_time;
5268 			else
5269 				tstmp_touse = (uint32_t)rsm->r_tim_lastsent[idx];
5270 			if (TSTMP_GT(cts, tstmp_touse))
5271 			    time_since_sent = cts - tstmp_touse;
5272 		}
5273 		if (SEQ_LT(tp->snd_una, tp->snd_max) || sbavail(&(tp->t_inpcb->inp_socket->so_snd))) {
5274 			rack->r_ctl.rc_hpts_flags |= PACE_TMR_RXT;
5275 			to = tp->t_rxtcur;
5276 			if (to > time_since_sent)
5277 				to -= time_since_sent;
5278 			else
5279 				to = rack->r_ctl.rc_min_to;
5280 			if (to == 0)
5281 				to = 1;
5282 			/* Special case for KEEPINIT */
5283 			if ((TCPS_HAVEESTABLISHED(tp->t_state) == 0) &&
5284 			    (TP_KEEPINIT(tp) != 0) &&
5285 			    rsm) {
5286 				/*
5287 				 * We have to put a ceiling on the rxt timer
5288 				 * of the keep-init timeout.
5289 				 */
5290 				uint32_t max_time, red;
5291 
5292 				max_time = TICKS_2_USEC(TP_KEEPINIT(tp));
5293 				if (TSTMP_GT(cts, (uint32_t)rsm->r_tim_lastsent[0])) {
5294 					red = (cts - (uint32_t)rsm->r_tim_lastsent[0]);
5295 					if (red < max_time)
5296 						max_time -= red;
5297 					else
5298 						max_time = 1;
5299 				}
5300 				/* Reduce timeout to the keep value if needed */
5301 				if (max_time < to)
5302 					to = max_time;
5303 			}
5304 			return (to);
5305 		}
5306 		return (0);
5307 	}
5308 	if (rsm->r_flags & RACK_ACKED) {
5309 		rsm = rack_find_lowest_rsm(rack);
5310 		if (rsm == NULL) {
5311 			/* No lowest? */
5312 			goto activate_rxt;
5313 		}
5314 	}
5315 	if (rack->sack_attack_disable) {
5316 		/*
5317 		 * We don't want to do
5318 		 * any TLP's if you are an attacker.
5319 		 * Though if you are doing what
5320 		 * is expected you may still have
5321 		 * SACK-PASSED marks.
5322 		 */
5323 		goto activate_rxt;
5324 	}
5325 	/* Convert from ms to usecs */
5326 	if ((rsm->r_flags & RACK_SACK_PASSED) ||
5327 	    (rsm->r_flags & RACK_RWND_COLLAPSED) ||
5328 	    (rsm->r_dupack >= DUP_ACK_THRESHOLD)) {
5329 		if ((tp->t_flags & TF_SENTFIN) &&
5330 		    ((tp->snd_max - tp->snd_una) == 1) &&
5331 		    (rsm->r_flags & RACK_HAS_FIN)) {
5332 			/*
5333 			 * We don't start a rack timer if all we have is a
5334 			 * FIN outstanding.
5335 			 */
5336 			goto activate_rxt;
5337 		}
5338 		if ((rack->use_rack_rr == 0) &&
5339 		    (IN_FASTRECOVERY(tp->t_flags)) &&
5340 		    (rack->rack_no_prr == 0) &&
5341 		     (rack->r_ctl.rc_prr_sndcnt  < ctf_fixed_maxseg(tp))) {
5342 			/*
5343 			 * We are not cheating, in recovery  and
5344 			 * not enough ack's to yet get our next
5345 			 * retransmission out.
5346 			 *
5347 			 * Note that classified attackers do not
5348 			 * get to use the rack-cheat.
5349 			 */
5350 			goto activate_tlp;
5351 		}
5352 		srtt = rack_grab_rtt(tp, rack);
5353 		thresh = rack_calc_thresh_rack(rack, srtt, cts);
5354 		idx = rsm->r_rtr_cnt - 1;
5355 		exp = ((uint32_t)rsm->r_tim_lastsent[idx]) + thresh;
5356 		if (SEQ_GEQ(exp, cts)) {
5357 			to = exp - cts;
5358 			if (to < rack->r_ctl.rc_min_to) {
5359 				to = rack->r_ctl.rc_min_to;
5360 				if (rack->r_rr_config == 3)
5361 					rack->rc_on_min_to = 1;
5362 			}
5363 		} else {
5364 			to = rack->r_ctl.rc_min_to;
5365 			if (rack->r_rr_config == 3)
5366 				rack->rc_on_min_to = 1;
5367 		}
5368 	} else {
5369 		/* Ok we need to do a TLP not RACK */
5370 activate_tlp:
5371 		if ((rack->rc_tlp_in_progress != 0) &&
5372 		    (rack->r_ctl.rc_tlp_cnt_out >= rack_tlp_limit)) {
5373 			/*
5374 			 * The previous send was a TLP and we have sent
5375 			 * N TLP's without sending new data.
5376 			 */
5377 			goto activate_rxt;
5378 		}
5379 		rsm = TAILQ_LAST_FAST(&rack->r_ctl.rc_tmap, rack_sendmap, r_tnext);
5380 		if (rsm == NULL) {
5381 			/* We found no rsm to TLP with. */
5382 			goto activate_rxt;
5383 		}
5384 		if (rsm->r_flags & RACK_HAS_FIN) {
5385 			/* If its a FIN we dont do TLP */
5386 			rsm = NULL;
5387 			goto activate_rxt;
5388 		}
5389 		idx = rsm->r_rtr_cnt - 1;
5390 		time_since_sent = 0;
5391 		if (TSTMP_GEQ(((uint32_t)rsm->r_tim_lastsent[idx]), rack->r_ctl.rc_tlp_rxt_last_time))
5392 			tstmp_touse = (uint32_t)rsm->r_tim_lastsent[idx];
5393 		else
5394 			tstmp_touse = (uint32_t)rack->r_ctl.rc_tlp_rxt_last_time;
5395 		if (TSTMP_GT(cts, tstmp_touse))
5396 		    time_since_sent = cts - tstmp_touse;
5397 		is_tlp_timer = 1;
5398 		if (tp->t_srtt) {
5399 			if ((rack->rc_srtt_measure_made == 0) &&
5400 			    (tp->t_srtt == 1)) {
5401 				/*
5402 				 * If another stack as run and set srtt to 1,
5403 				 * then the srtt was 0, so lets use the initial.
5404 				 */
5405 				srtt = RACK_INITIAL_RTO;
5406 			} else {
5407 				srtt_cur = tp->t_srtt;
5408 				srtt = srtt_cur;
5409 			}
5410 		} else
5411 			srtt = RACK_INITIAL_RTO;
5412 		/*
5413 		 * If the SRTT is not keeping up and the
5414 		 * rack RTT has spiked we want to use
5415 		 * the last RTT not the smoothed one.
5416 		 */
5417 		if (rack_tlp_use_greater &&
5418 		    tp->t_srtt &&
5419 		    (srtt < rack_grab_rtt(tp, rack))) {
5420 			srtt = rack_grab_rtt(tp, rack);
5421 		}
5422 		thresh = rack_calc_thresh_tlp(tp, rack, rsm, srtt);
5423 		if (thresh > time_since_sent) {
5424 			to = thresh - time_since_sent;
5425 		} else {
5426 			to = rack->r_ctl.rc_min_to;
5427 			rack_log_alt_to_to_cancel(rack,
5428 						  thresh,		/* flex1 */
5429 						  time_since_sent,	/* flex2 */
5430 						  tstmp_touse,		/* flex3 */
5431 						  rack->r_ctl.rc_tlp_rxt_last_time, /* flex4 */
5432 						  (uint32_t)rsm->r_tim_lastsent[idx],
5433 						  srtt,
5434 						  idx, 99);
5435 		}
5436 		if (to < rack_tlp_min) {
5437 			to = rack_tlp_min;
5438 		}
5439 		if (to > TICKS_2_USEC(TCPTV_REXMTMAX)) {
5440 			/*
5441 			 * If the TLP time works out to larger than the max
5442 			 * RTO lets not do TLP.. just RTO.
5443 			 */
5444 			goto activate_rxt;
5445 		}
5446 	}
5447 	if (is_tlp_timer == 0) {
5448 		rack->r_ctl.rc_hpts_flags |= PACE_TMR_RACK;
5449 	} else {
5450 		rack->r_ctl.rc_hpts_flags |= PACE_TMR_TLP;
5451 	}
5452 	if (to == 0)
5453 		to = 1;
5454 	return (to);
5455 }
5456 
5457 static void
5458 rack_enter_persist(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cts)
5459 {
5460 	if (rack->rc_in_persist == 0) {
5461 		if (tp->t_flags & TF_GPUTINPROG) {
5462 			/*
5463 			 * Stop the goodput now, the calling of the
5464 			 * measurement function clears the flag.
5465 			 */
5466 			rack_do_goodput_measurement(tp, rack, tp->snd_una, __LINE__,
5467 						    RACK_QUALITY_PERSIST);
5468 		}
5469 #ifdef NETFLIX_SHARED_CWND
5470 		if (rack->r_ctl.rc_scw) {
5471 			tcp_shared_cwnd_idle(rack->r_ctl.rc_scw, rack->r_ctl.rc_scw_index);
5472 			rack->rack_scwnd_is_idle = 1;
5473 		}
5474 #endif
5475 		rack->r_ctl.rc_went_idle_time = tcp_get_usecs(NULL);
5476 		if (rack->r_ctl.rc_went_idle_time == 0)
5477 			rack->r_ctl.rc_went_idle_time = 1;
5478 		rack_timer_cancel(tp, rack, cts, __LINE__);
5479 		rack->r_ctl.persist_lost_ends = 0;
5480 		rack->probe_not_answered = 0;
5481 		rack->forced_ack = 0;
5482 		tp->t_rxtshift = 0;
5483 		RACK_TCPT_RANGESET(tp->t_rxtcur, RACK_REXMTVAL(tp),
5484 			      rack_rto_min, rack_rto_max, rack->r_ctl.timer_slop);
5485 		rack->rc_in_persist = 1;
5486 	}
5487 }
5488 
5489 static void
5490 rack_exit_persist(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cts)
5491 {
5492 	if (tcp_in_hpts(rack->rc_inp)) {
5493 		tcp_hpts_remove(rack->rc_inp);
5494 		rack->r_ctl.rc_hpts_flags = 0;
5495 	}
5496 #ifdef NETFLIX_SHARED_CWND
5497 	if (rack->r_ctl.rc_scw) {
5498 		tcp_shared_cwnd_active(rack->r_ctl.rc_scw, rack->r_ctl.rc_scw_index);
5499 		rack->rack_scwnd_is_idle = 0;
5500 	}
5501 #endif
5502 	if (rack->rc_gp_dyn_mul &&
5503 	    (rack->use_fixed_rate == 0) &&
5504 	    (rack->rc_always_pace)) {
5505 		/*
5506 		 * Do we count this as if a probe-rtt just
5507 		 * finished?
5508 		 */
5509 		uint32_t time_idle, idle_min;
5510 
5511 		time_idle = tcp_get_usecs(NULL) - rack->r_ctl.rc_went_idle_time;
5512 		idle_min = rack_min_probertt_hold;
5513 		if (rack_probertt_gpsrtt_cnt_div) {
5514 			uint64_t extra;
5515 			extra = (uint64_t)rack->r_ctl.rc_gp_srtt *
5516 				(uint64_t)rack_probertt_gpsrtt_cnt_mul;
5517 			extra /= (uint64_t)rack_probertt_gpsrtt_cnt_div;
5518 			idle_min += (uint32_t)extra;
5519 		}
5520 		if (time_idle >= idle_min) {
5521 			/* Yes, we count it as a probe-rtt. */
5522 			uint32_t us_cts;
5523 
5524 			us_cts = tcp_get_usecs(NULL);
5525 			if (rack->in_probe_rtt == 0) {
5526 				rack->r_ctl.rc_lower_rtt_us_cts = us_cts;
5527 				rack->r_ctl.rc_time_probertt_entered = rack->r_ctl.rc_lower_rtt_us_cts;
5528 				rack->r_ctl.rc_time_probertt_starts = rack->r_ctl.rc_lower_rtt_us_cts;
5529 				rack->r_ctl.rc_time_of_last_probertt = rack->r_ctl.rc_lower_rtt_us_cts;
5530 			} else {
5531 				rack_exit_probertt(rack, us_cts);
5532 			}
5533 		}
5534 	}
5535 	rack->rc_in_persist = 0;
5536 	rack->r_ctl.rc_went_idle_time = 0;
5537 	tp->t_rxtshift = 0;
5538 	RACK_TCPT_RANGESET(tp->t_rxtcur, RACK_REXMTVAL(tp),
5539 	   rack_rto_min, rack_rto_max, rack->r_ctl.timer_slop);
5540 	rack->r_ctl.rc_agg_delayed = 0;
5541 	rack->r_early = 0;
5542 	rack->r_late = 0;
5543 	rack->r_ctl.rc_agg_early = 0;
5544 }
5545 
5546 static void
5547 rack_log_hpts_diag(struct tcp_rack *rack, uint32_t cts,
5548 		   struct hpts_diag *diag, struct timeval *tv)
5549 {
5550 	if (rack_verbose_logging && rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
5551 		union tcp_log_stackspecific log;
5552 
5553 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
5554 		log.u_bbr.flex1 = diag->p_nxt_slot;
5555 		log.u_bbr.flex2 = diag->p_cur_slot;
5556 		log.u_bbr.flex3 = diag->slot_req;
5557 		log.u_bbr.flex4 = diag->inp_hptsslot;
5558 		log.u_bbr.flex5 = diag->slot_remaining;
5559 		log.u_bbr.flex6 = diag->need_new_to;
5560 		log.u_bbr.flex7 = diag->p_hpts_active;
5561 		log.u_bbr.flex8 = diag->p_on_min_sleep;
5562 		/* Hijack other fields as needed */
5563 		log.u_bbr.epoch = diag->have_slept;
5564 		log.u_bbr.lt_epoch = diag->yet_to_sleep;
5565 		log.u_bbr.pkts_out = diag->co_ret;
5566 		log.u_bbr.applimited = diag->hpts_sleep_time;
5567 		log.u_bbr.delivered = diag->p_prev_slot;
5568 		log.u_bbr.inflight = diag->p_runningslot;
5569 		log.u_bbr.bw_inuse = diag->wheel_slot;
5570 		log.u_bbr.rttProp = diag->wheel_cts;
5571 		log.u_bbr.timeStamp = cts;
5572 		log.u_bbr.delRate = diag->maxslots;
5573 		log.u_bbr.cur_del_rate = diag->p_curtick;
5574 		log.u_bbr.cur_del_rate <<= 32;
5575 		log.u_bbr.cur_del_rate |= diag->p_lasttick;
5576 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
5577 		    &rack->rc_inp->inp_socket->so_rcv,
5578 		    &rack->rc_inp->inp_socket->so_snd,
5579 		    BBR_LOG_HPTSDIAG, 0,
5580 		    0, &log, false, tv);
5581 	}
5582 
5583 }
5584 
5585 static void
5586 rack_log_wakeup(struct tcpcb *tp, struct tcp_rack *rack, struct sockbuf *sb, uint32_t len, int type)
5587 {
5588 	if (rack_verbose_logging && rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
5589 		union tcp_log_stackspecific log;
5590 		struct timeval tv;
5591 
5592 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
5593 		log.u_bbr.flex1 = sb->sb_flags;
5594 		log.u_bbr.flex2 = len;
5595 		log.u_bbr.flex3 = sb->sb_state;
5596 		log.u_bbr.flex8 = type;
5597 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
5598 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
5599 		    &rack->rc_inp->inp_socket->so_rcv,
5600 		    &rack->rc_inp->inp_socket->so_snd,
5601 		    TCP_LOG_SB_WAKE, 0,
5602 		    len, &log, false, &tv);
5603 	}
5604 }
5605 
5606 static void
5607 rack_start_hpts_timer(struct tcp_rack *rack, struct tcpcb *tp, uint32_t cts,
5608       int32_t slot, uint32_t tot_len_this_send, int sup_rack)
5609 {
5610 	struct hpts_diag diag;
5611 	struct inpcb *inp;
5612 	struct timeval tv;
5613 	uint32_t delayed_ack = 0;
5614 	uint32_t hpts_timeout;
5615 	uint32_t entry_slot = slot;
5616 	uint8_t stopped;
5617 	uint32_t left = 0;
5618 	uint32_t us_cts;
5619 
5620 	inp = tp->t_inpcb;
5621 	if ((tp->t_state == TCPS_CLOSED) ||
5622 	    (tp->t_state == TCPS_LISTEN)) {
5623 		return;
5624 	}
5625 	if (tcp_in_hpts(inp)) {
5626 		/* Already on the pacer */
5627 		return;
5628 	}
5629 	stopped = rack->rc_tmr_stopped;
5630 	if (stopped && TSTMP_GT(rack->r_ctl.rc_timer_exp, cts)) {
5631 		left = rack->r_ctl.rc_timer_exp - cts;
5632 	}
5633 	rack->r_ctl.rc_timer_exp = 0;
5634 	rack->r_ctl.rc_hpts_flags = 0;
5635 	us_cts = tcp_get_usecs(&tv);
5636 	/* Now early/late accounting */
5637 	rack_log_pacing_delay_calc(rack, entry_slot, slot, 0, 0, 0, 26, __LINE__, NULL, 0);
5638 	if (rack->r_early && (rack->rc_ack_can_sendout_data == 0)) {
5639 		/*
5640 		 * We have a early carry over set,
5641 		 * we can always add more time so we
5642 		 * can always make this compensation.
5643 		 *
5644 		 * Note if ack's are allowed to wake us do not
5645 		 * penalize the next timer for being awoke
5646 		 * by an ack aka the rc_agg_early (non-paced mode).
5647 		 */
5648 		slot += rack->r_ctl.rc_agg_early;
5649 		rack->r_early = 0;
5650 		rack->r_ctl.rc_agg_early = 0;
5651 	}
5652 	if (rack->r_late) {
5653 		/*
5654 		 * This is harder, we can
5655 		 * compensate some but it
5656 		 * really depends on what
5657 		 * the current pacing time is.
5658 		 */
5659 		if (rack->r_ctl.rc_agg_delayed >= slot) {
5660 			/*
5661 			 * We can't compensate for it all.
5662 			 * And we have to have some time
5663 			 * on the clock. We always have a min
5664 			 * 10 slots (10 x 10 i.e. 100 usecs).
5665 			 */
5666 			if (slot <= HPTS_TICKS_PER_SLOT) {
5667 				/* We gain delay */
5668 				rack->r_ctl.rc_agg_delayed += (HPTS_TICKS_PER_SLOT - slot);
5669 				slot = HPTS_TICKS_PER_SLOT;
5670 			} else {
5671 				/* We take off some */
5672 				rack->r_ctl.rc_agg_delayed -= (slot - HPTS_TICKS_PER_SLOT);
5673 				slot = HPTS_TICKS_PER_SLOT;
5674 			}
5675 		} else {
5676 			slot -= rack->r_ctl.rc_agg_delayed;
5677 			rack->r_ctl.rc_agg_delayed = 0;
5678 			/* Make sure we have 100 useconds at minimum */
5679 			if (slot < HPTS_TICKS_PER_SLOT) {
5680 				rack->r_ctl.rc_agg_delayed = HPTS_TICKS_PER_SLOT - slot;
5681 				slot = HPTS_TICKS_PER_SLOT;
5682 			}
5683 			if (rack->r_ctl.rc_agg_delayed == 0)
5684 				rack->r_late = 0;
5685 		}
5686 	}
5687 	if (slot) {
5688 		/* We are pacing too */
5689 		rack->r_ctl.rc_hpts_flags |= PACE_PKT_OUTPUT;
5690 	}
5691 	hpts_timeout = rack_timer_start(tp, rack, cts, sup_rack);
5692 #ifdef NETFLIX_EXP_DETECTION
5693 	if (rack->sack_attack_disable &&
5694 	    (slot < tcp_sad_pacing_interval)) {
5695 		/*
5696 		 * We have a potential attacker on
5697 		 * the line. We have possibly some
5698 		 * (or now) pacing time set. We want to
5699 		 * slow down the processing of sacks by some
5700 		 * amount (if it is an attacker). Set the default
5701 		 * slot for attackers in place (unless the orginal
5702 		 * interval is longer). Its stored in
5703 		 * micro-seconds, so lets convert to msecs.
5704 		 */
5705 		slot = tcp_sad_pacing_interval;
5706 	}
5707 #endif
5708 	if (tp->t_flags & TF_DELACK) {
5709 		delayed_ack = TICKS_2_USEC(tcp_delacktime);
5710 		rack->r_ctl.rc_hpts_flags |= PACE_TMR_DELACK;
5711 	}
5712 	if (delayed_ack && ((hpts_timeout == 0) ||
5713 			    (delayed_ack < hpts_timeout)))
5714 		hpts_timeout = delayed_ack;
5715 	else
5716 		rack->r_ctl.rc_hpts_flags &= ~PACE_TMR_DELACK;
5717 	/*
5718 	 * If no timers are going to run and we will fall off the hptsi
5719 	 * wheel, we resort to a keep-alive timer if its configured.
5720 	 */
5721 	if ((hpts_timeout == 0) &&
5722 	    (slot == 0)) {
5723 		if ((V_tcp_always_keepalive || inp->inp_socket->so_options & SO_KEEPALIVE) &&
5724 		    (tp->t_state <= TCPS_CLOSING)) {
5725 			/*
5726 			 * Ok we have no timer (persists, rack, tlp, rxt  or
5727 			 * del-ack), we don't have segments being paced. So
5728 			 * all that is left is the keepalive timer.
5729 			 */
5730 			if (TCPS_HAVEESTABLISHED(tp->t_state)) {
5731 				/* Get the established keep-alive time */
5732 				hpts_timeout = TICKS_2_USEC(TP_KEEPIDLE(tp));
5733 			} else {
5734 				/*
5735 				 * Get the initial setup keep-alive time,
5736 				 * note that this is probably not going to
5737 				 * happen, since rack will be running a rxt timer
5738 				 * if a SYN of some sort is outstanding. It is
5739 				 * actually handled in rack_timeout_rxt().
5740 				 */
5741 				hpts_timeout = TICKS_2_USEC(TP_KEEPINIT(tp));
5742 			}
5743 			rack->r_ctl.rc_hpts_flags |= PACE_TMR_KEEP;
5744 			if (rack->in_probe_rtt) {
5745 				/*
5746 				 * We want to instead not wake up a long time from
5747 				 * now but to wake up about the time we would
5748 				 * exit probe-rtt and initiate a keep-alive ack.
5749 				 * This will get us out of probe-rtt and update
5750 				 * our min-rtt.
5751 				 */
5752 				hpts_timeout = rack_min_probertt_hold;
5753 			}
5754 		}
5755 	}
5756 	if (left && (stopped & (PACE_TMR_KEEP | PACE_TMR_DELACK)) ==
5757 	    (rack->r_ctl.rc_hpts_flags & PACE_TMR_MASK)) {
5758 		/*
5759 		 * RACK, TLP, persists and RXT timers all are restartable
5760 		 * based on actions input .. i.e we received a packet (ack
5761 		 * or sack) and that changes things (rw, or snd_una etc).
5762 		 * Thus we can restart them with a new value. For
5763 		 * keep-alive, delayed_ack we keep track of what was left
5764 		 * and restart the timer with a smaller value.
5765 		 */
5766 		if (left < hpts_timeout)
5767 			hpts_timeout = left;
5768 	}
5769 	if (hpts_timeout) {
5770 		/*
5771 		 * Hack alert for now we can't time-out over 2,147,483
5772 		 * seconds (a bit more than 596 hours), which is probably ok
5773 		 * :).
5774 		 */
5775 		if (hpts_timeout > 0x7ffffffe)
5776 			hpts_timeout = 0x7ffffffe;
5777 		rack->r_ctl.rc_timer_exp = cts + hpts_timeout;
5778 	}
5779 	rack_log_pacing_delay_calc(rack, entry_slot, slot, hpts_timeout, 0, 0, 27, __LINE__, NULL, 0);
5780 	if ((rack->gp_ready == 0) &&
5781 	    (rack->use_fixed_rate == 0) &&
5782 	    (hpts_timeout < slot) &&
5783 	    (rack->r_ctl.rc_hpts_flags & (PACE_TMR_TLP|PACE_TMR_RXT))) {
5784 		/*
5785 		 * We have no good estimate yet for the
5786 		 * old clunky burst mitigation or the
5787 		 * real pacing. And the tlp or rxt is smaller
5788 		 * than the pacing calculation. Lets not
5789 		 * pace that long since we know the calculation
5790 		 * so far is not accurate.
5791 		 */
5792 		slot = hpts_timeout;
5793 	}
5794 	/**
5795 	 * Turn off all the flags for queuing by default. The
5796 	 * flags have important meanings to what happens when
5797 	 * LRO interacts with the transport. Most likely (by default now)
5798 	 * mbuf_queueing and ack compression are on. So the transport
5799 	 * has a couple of flags that control what happens (if those
5800 	 * are not on then these flags won't have any effect since it
5801 	 * won't go through the queuing LRO path).
5802 	 *
5803 	 * INP_MBUF_QUEUE_READY - This flags says that I am busy
5804 	 *                        pacing output, so don't disturb. But
5805 	 *                        it also means LRO can wake me if there
5806 	 *                        is a SACK arrival.
5807 	 *
5808 	 * INP_DONT_SACK_QUEUE - This flag is used in conjunction
5809 	 *                       with the above flag (QUEUE_READY) and
5810 	 *                       when present it says don't even wake me
5811 	 *                       if a SACK arrives.
5812 	 *
5813 	 * The idea behind these flags is that if we are pacing we
5814 	 * set the MBUF_QUEUE_READY and only get woken up if
5815 	 * a SACK arrives (which could change things) or if
5816 	 * our pacing timer expires. If, however, we have a rack
5817 	 * timer running, then we don't even want a sack to wake
5818 	 * us since the rack timer has to expire before we can send.
5819 	 *
5820 	 * Other cases should usually have none of the flags set
5821 	 * so LRO can call into us.
5822 	 */
5823 	inp->inp_flags2 &= ~(INP_DONT_SACK_QUEUE|INP_MBUF_QUEUE_READY);
5824 	if (slot) {
5825 		rack->r_ctl.rc_last_output_to = us_cts + slot;
5826 		/*
5827 		 * A pacing timer (slot) is being set, in
5828 		 * such a case we cannot send (we are blocked by
5829 		 * the timer). So lets tell LRO that it should not
5830 		 * wake us unless there is a SACK. Note this only
5831 		 * will be effective if mbuf queueing is on or
5832 		 * compressed acks are being processed.
5833 		 */
5834 		inp->inp_flags2 |= INP_MBUF_QUEUE_READY;
5835 		/*
5836 		 * But wait if we have a Rack timer running
5837 		 * even a SACK should not disturb us (with
5838 		 * the exception of r_rr_config 3).
5839 		 */
5840 		if ((rack->r_ctl.rc_hpts_flags & PACE_TMR_RACK) &&
5841 		    (rack->r_rr_config != 3))
5842 			inp->inp_flags2 |= INP_DONT_SACK_QUEUE;
5843 		if (rack->rc_ack_can_sendout_data) {
5844 			/*
5845 			 * Ahh but wait, this is that special case
5846 			 * where the pacing timer can be disturbed
5847 			 * backout the changes (used for non-paced
5848 			 * burst limiting).
5849 			 */
5850 			inp->inp_flags2 &= ~(INP_DONT_SACK_QUEUE|INP_MBUF_QUEUE_READY);
5851 		}
5852 		if ((rack->use_rack_rr) &&
5853 		    (rack->r_rr_config < 2) &&
5854 		    ((hpts_timeout) && (hpts_timeout < slot))) {
5855 			/*
5856 			 * Arrange for the hpts to kick back in after the
5857 			 * t-o if the t-o does not cause a send.
5858 			 */
5859 			(void)tcp_hpts_insert_diag(tp->t_inpcb, HPTS_USEC_TO_SLOTS(hpts_timeout),
5860 						   __LINE__, &diag);
5861 			rack_log_hpts_diag(rack, us_cts, &diag, &tv);
5862 			rack_log_to_start(rack, cts, hpts_timeout, slot, 0);
5863 		} else {
5864 			(void)tcp_hpts_insert_diag(tp->t_inpcb, HPTS_USEC_TO_SLOTS(slot),
5865 						   __LINE__, &diag);
5866 			rack_log_hpts_diag(rack, us_cts, &diag, &tv);
5867 			rack_log_to_start(rack, cts, hpts_timeout, slot, 1);
5868 		}
5869 	} else if (hpts_timeout) {
5870 		/*
5871 		 * With respect to inp_flags2 here, lets let any new acks wake
5872 		 * us up here. Since we are not pacing (no pacing timer), output
5873 		 * can happen so we should let it. If its a Rack timer, then any inbound
5874 		 * packet probably won't change the sending (we will be blocked)
5875 		 * but it may change the prr stats so letting it in (the set defaults
5876 		 * at the start of this block) are good enough.
5877 		 */
5878 		(void)tcp_hpts_insert_diag(tp->t_inpcb, HPTS_USEC_TO_SLOTS(hpts_timeout),
5879 					   __LINE__, &diag);
5880 		rack_log_hpts_diag(rack, us_cts, &diag, &tv);
5881 		rack_log_to_start(rack, cts, hpts_timeout, slot, 0);
5882 	} else {
5883 		/* No timer starting */
5884 #ifdef INVARIANTS
5885 		if (SEQ_GT(tp->snd_max, tp->snd_una)) {
5886 			panic("tp:%p rack:%p tlts:%d cts:%u slot:%u pto:%u -- no timer started?",
5887 			    tp, rack, tot_len_this_send, cts, slot, hpts_timeout);
5888 		}
5889 #endif
5890 	}
5891 	rack->rc_tmr_stopped = 0;
5892 	if (slot)
5893 		rack_log_type_bbrsnd(rack, tot_len_this_send, slot, us_cts, &tv);
5894 }
5895 
5896 /*
5897  * RACK Timer, here we simply do logging and house keeping.
5898  * the normal rack_output() function will call the
5899  * appropriate thing to check if we need to do a RACK retransmit.
5900  * We return 1, saying don't proceed with rack_output only
5901  * when all timers have been stopped (destroyed PCB?).
5902  */
5903 static int
5904 rack_timeout_rack(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cts)
5905 {
5906 	/*
5907 	 * This timer simply provides an internal trigger to send out data.
5908 	 * The check_recovery_mode call will see if there are needed
5909 	 * retransmissions, if so we will enter fast-recovery. The output
5910 	 * call may or may not do the same thing depending on sysctl
5911 	 * settings.
5912 	 */
5913 	struct rack_sendmap *rsm;
5914 
5915 	if (tp->t_timers->tt_flags & TT_STOPPED) {
5916 		return (1);
5917 	}
5918 	counter_u64_add(rack_to_tot, 1);
5919 	if (rack->r_state && (rack->r_state != tp->t_state))
5920 		rack_set_state(tp, rack);
5921 	rack->rc_on_min_to = 0;
5922 	rsm = rack_check_recovery_mode(tp, cts);
5923 	rack_log_to_event(rack, RACK_TO_FRM_RACK, rsm);
5924 	if (rsm) {
5925 		rack->r_ctl.rc_resend = rsm;
5926 		rack->r_timer_override = 1;
5927 		if (rack->use_rack_rr) {
5928 			/*
5929 			 * Don't accumulate extra pacing delay
5930 			 * we are allowing the rack timer to
5931 			 * over-ride pacing i.e. rrr takes precedence
5932 			 * if the pacing interval is longer than the rrr
5933 			 * time (in other words we get the min pacing
5934 			 * time versus rrr pacing time).
5935 			 */
5936 			rack->r_ctl.rc_hpts_flags &= ~PACE_PKT_OUTPUT;
5937 		}
5938 	}
5939 	rack->r_ctl.rc_hpts_flags &= ~PACE_TMR_RACK;
5940 	if (rsm == NULL) {
5941 		/* restart a timer and return 1 */
5942 		rack_start_hpts_timer(rack, tp, cts,
5943 				      0, 0, 0);
5944 		return (1);
5945 	}
5946 	return (0);
5947 }
5948 
5949 static void
5950 rack_adjust_orig_mlen(struct rack_sendmap *rsm)
5951 {
5952 	if (rsm->m->m_len > rsm->orig_m_len) {
5953 		/*
5954 		 * Mbuf grew, caused by sbcompress, our offset does
5955 		 * not change.
5956 		 */
5957 		rsm->orig_m_len = rsm->m->m_len;
5958 	} else if (rsm->m->m_len < rsm->orig_m_len) {
5959 		/*
5960 		 * Mbuf shrank, trimmed off the top by an ack, our
5961 		 * offset changes.
5962 		 */
5963 		rsm->soff -= (rsm->orig_m_len - rsm->m->m_len);
5964 		rsm->orig_m_len = rsm->m->m_len;
5965 	}
5966 }
5967 
5968 static void
5969 rack_setup_offset_for_rsm(struct rack_sendmap *src_rsm, struct rack_sendmap *rsm)
5970 {
5971 	struct mbuf *m;
5972 	uint32_t soff;
5973 
5974 	if (src_rsm->m && (src_rsm->orig_m_len != src_rsm->m->m_len)) {
5975 		/* Fix up the orig_m_len and possibly the mbuf offset */
5976 		rack_adjust_orig_mlen(src_rsm);
5977 	}
5978 	m = src_rsm->m;
5979 	soff = src_rsm->soff + (src_rsm->r_end - src_rsm->r_start);
5980 	while (soff >= m->m_len) {
5981 		/* Move out past this mbuf */
5982 		soff -= m->m_len;
5983 		m = m->m_next;
5984 		KASSERT((m != NULL),
5985 			("rsm:%p nrsm:%p hit at soff:%u null m",
5986 			 src_rsm, rsm, soff));
5987 	}
5988 	rsm->m = m;
5989 	rsm->soff = soff;
5990 	rsm->orig_m_len = m->m_len;
5991 }
5992 
5993 static __inline void
5994 rack_clone_rsm(struct tcp_rack *rack, struct rack_sendmap *nrsm,
5995 	       struct rack_sendmap *rsm, uint32_t start)
5996 {
5997 	int idx;
5998 
5999 	nrsm->r_start = start;
6000 	nrsm->r_end = rsm->r_end;
6001 	nrsm->r_rtr_cnt = rsm->r_rtr_cnt;
6002 	nrsm->r_flags = rsm->r_flags;
6003 	nrsm->r_dupack = rsm->r_dupack;
6004 	nrsm->r_no_rtt_allowed = rsm->r_no_rtt_allowed;
6005 	nrsm->r_rtr_bytes = 0;
6006 	nrsm->r_fas = rsm->r_fas;
6007 	rsm->r_end = nrsm->r_start;
6008 	nrsm->r_just_ret = rsm->r_just_ret;
6009 	for (idx = 0; idx < nrsm->r_rtr_cnt; idx++) {
6010 		nrsm->r_tim_lastsent[idx] = rsm->r_tim_lastsent[idx];
6011 	}
6012 	/* Now if we have SYN flag we keep it on the left edge */
6013 	if (nrsm->r_flags & RACK_HAS_SYN)
6014 		nrsm->r_flags &= ~RACK_HAS_SYN;
6015 	/* Now if we have a FIN flag we keep it on the right edge */
6016 	if (rsm->r_flags & RACK_HAS_FIN)
6017 		rsm->r_flags &= ~RACK_HAS_FIN;
6018 	/* Push bit must go to the right edge as well */
6019 	if (rsm->r_flags & RACK_HAD_PUSH)
6020 		rsm->r_flags &= ~RACK_HAD_PUSH;
6021 	/* Clone over the state of the hw_tls flag */
6022 	nrsm->r_hw_tls = rsm->r_hw_tls;
6023 	/*
6024 	 * Now we need to find nrsm's new location in the mbuf chain
6025 	 * we basically calculate a new offset, which is soff +
6026 	 * how much is left in original rsm. Then we walk out the mbuf
6027 	 * chain to find the righ position, it may be the same mbuf
6028 	 * or maybe not.
6029 	 */
6030 	KASSERT(((rsm->m != NULL) ||
6031 		 (rsm->r_flags & (RACK_HAS_SYN|RACK_HAS_FIN))),
6032 		("rsm:%p nrsm:%p rack:%p -- rsm->m is NULL?", rsm, nrsm, rack));
6033 	if (rsm->m)
6034 		rack_setup_offset_for_rsm(rsm, nrsm);
6035 }
6036 
6037 static struct rack_sendmap *
6038 rack_merge_rsm(struct tcp_rack *rack,
6039 	       struct rack_sendmap *l_rsm,
6040 	       struct rack_sendmap *r_rsm)
6041 {
6042 	/*
6043 	 * We are merging two ack'd RSM's,
6044 	 * the l_rsm is on the left (lower seq
6045 	 * values) and the r_rsm is on the right
6046 	 * (higher seq value). The simplest way
6047 	 * to merge these is to move the right
6048 	 * one into the left. I don't think there
6049 	 * is any reason we need to try to find
6050 	 * the oldest (or last oldest retransmitted).
6051 	 */
6052 #ifdef INVARIANTS
6053 	struct rack_sendmap *rm;
6054 #endif
6055 	rack_log_map_chg(rack->rc_tp, rack, NULL,
6056 			 l_rsm, r_rsm, MAP_MERGE, r_rsm->r_end, __LINE__);
6057 	l_rsm->r_end = r_rsm->r_end;
6058 	if (l_rsm->r_dupack < r_rsm->r_dupack)
6059 		l_rsm->r_dupack = r_rsm->r_dupack;
6060 	if (r_rsm->r_rtr_bytes)
6061 		l_rsm->r_rtr_bytes += r_rsm->r_rtr_bytes;
6062 	if (r_rsm->r_in_tmap) {
6063 		/* This really should not happen */
6064 		TAILQ_REMOVE(&rack->r_ctl.rc_tmap, r_rsm, r_tnext);
6065 		r_rsm->r_in_tmap = 0;
6066 	}
6067 
6068 	/* Now the flags */
6069 	if (r_rsm->r_flags & RACK_HAS_FIN)
6070 		l_rsm->r_flags |= RACK_HAS_FIN;
6071 	if (r_rsm->r_flags & RACK_TLP)
6072 		l_rsm->r_flags |= RACK_TLP;
6073 	if (r_rsm->r_flags & RACK_RWND_COLLAPSED)
6074 		l_rsm->r_flags |= RACK_RWND_COLLAPSED;
6075 	if ((r_rsm->r_flags & RACK_APP_LIMITED)  &&
6076 	    ((l_rsm->r_flags & RACK_APP_LIMITED) == 0)) {
6077 		/*
6078 		 * If both are app-limited then let the
6079 		 * free lower the count. If right is app
6080 		 * limited and left is not, transfer.
6081 		 */
6082 		l_rsm->r_flags |= RACK_APP_LIMITED;
6083 		r_rsm->r_flags &= ~RACK_APP_LIMITED;
6084 		if (r_rsm == rack->r_ctl.rc_first_appl)
6085 			rack->r_ctl.rc_first_appl = l_rsm;
6086 	}
6087 #ifndef INVARIANTS
6088 	(void)RB_REMOVE(rack_rb_tree_head, &rack->r_ctl.rc_mtree, r_rsm);
6089 #else
6090 	rm = RB_REMOVE(rack_rb_tree_head, &rack->r_ctl.rc_mtree, r_rsm);
6091 	if (rm != r_rsm) {
6092 		panic("removing head in rack:%p rsm:%p rm:%p",
6093 		      rack, r_rsm, rm);
6094 	}
6095 #endif
6096 	if ((r_rsm->r_limit_type == 0) && (l_rsm->r_limit_type != 0)) {
6097 		/* Transfer the split limit to the map we free */
6098 		r_rsm->r_limit_type = l_rsm->r_limit_type;
6099 		l_rsm->r_limit_type = 0;
6100 	}
6101 	rack_free(rack, r_rsm);
6102 	return (l_rsm);
6103 }
6104 
6105 /*
6106  * TLP Timer, here we simply setup what segment we want to
6107  * have the TLP expire on, the normal rack_output() will then
6108  * send it out.
6109  *
6110  * We return 1, saying don't proceed with rack_output only
6111  * when all timers have been stopped (destroyed PCB?).
6112  */
6113 static int
6114 rack_timeout_tlp(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cts, uint8_t *doing_tlp)
6115 {
6116 	/*
6117 	 * Tail Loss Probe.
6118 	 */
6119 	struct rack_sendmap *rsm = NULL;
6120 #ifdef INVARIANTS
6121 	struct rack_sendmap *insret;
6122 #endif
6123 	struct socket *so;
6124 	uint32_t amm;
6125 	uint32_t out, avail;
6126 	int collapsed_win = 0;
6127 
6128 	if (tp->t_timers->tt_flags & TT_STOPPED) {
6129 		return (1);
6130 	}
6131 	if (TSTMP_LT(cts, rack->r_ctl.rc_timer_exp)) {
6132 		/* Its not time yet */
6133 		return (0);
6134 	}
6135 	if (ctf_progress_timeout_check(tp, true)) {
6136 		rack_log_progress_event(rack, tp, tick, PROGRESS_DROP, __LINE__);
6137 		return (-ETIMEDOUT);	/* tcp_drop() */
6138 	}
6139 	/*
6140 	 * A TLP timer has expired. We have been idle for 2 rtts. So we now
6141 	 * need to figure out how to force a full MSS segment out.
6142 	 */
6143 	rack_log_to_event(rack, RACK_TO_FRM_TLP, NULL);
6144 	rack->r_ctl.retran_during_recovery = 0;
6145 	rack->r_ctl.dsack_byte_cnt = 0;
6146 	counter_u64_add(rack_tlp_tot, 1);
6147 	if (rack->r_state && (rack->r_state != tp->t_state))
6148 		rack_set_state(tp, rack);
6149 	so = tp->t_inpcb->inp_socket;
6150 	avail = sbavail(&so->so_snd);
6151 	out = tp->snd_max - tp->snd_una;
6152 	if ((out > tp->snd_wnd) || rack->rc_has_collapsed) {
6153 		/* special case, we need a retransmission */
6154 		collapsed_win = 1;
6155 		goto need_retran;
6156 	}
6157 	if (rack->r_ctl.dsack_persist && (rack->r_ctl.rc_tlp_cnt_out >= 1)) {
6158 		rack->r_ctl.dsack_persist--;
6159 		if (rack->r_ctl.num_dsack && (rack->r_ctl.dsack_persist == 0)) {
6160 			rack->r_ctl.num_dsack = 0;
6161 		}
6162 		rack_log_dsack_event(rack, 1, __LINE__, 0, 0);
6163 	}
6164 	if ((tp->t_flags & TF_GPUTINPROG) &&
6165 	    (rack->r_ctl.rc_tlp_cnt_out == 1)) {
6166 		/*
6167 		 * If this is the second in a row
6168 		 * TLP and we are doing a measurement
6169 		 * its time to abandon the measurement.
6170 		 * Something is likely broken on
6171 		 * the clients network and measuring a
6172 		 * broken network does us no good.
6173 		 */
6174 		tp->t_flags &= ~TF_GPUTINPROG;
6175 		rack_log_pacing_delay_calc(rack, (tp->gput_ack - tp->gput_seq) /*flex2*/,
6176 					   rack->r_ctl.rc_gp_srtt /*flex1*/,
6177 					   tp->gput_seq,
6178 					   0, 0, 18, __LINE__, NULL, 0);
6179 	}
6180 	/*
6181 	 * Check our send oldest always settings, and if
6182 	 * there is an oldest to send jump to the need_retran.
6183 	 */
6184 	if (rack_always_send_oldest && (TAILQ_EMPTY(&rack->r_ctl.rc_tmap) == 0))
6185 		goto need_retran;
6186 
6187 	if (avail > out) {
6188 		/* New data is available */
6189 		amm = avail - out;
6190 		if (amm > ctf_fixed_maxseg(tp)) {
6191 			amm = ctf_fixed_maxseg(tp);
6192 			if ((amm + out) > tp->snd_wnd) {
6193 				/* We are rwnd limited */
6194 				goto need_retran;
6195 			}
6196 		} else if (amm < ctf_fixed_maxseg(tp)) {
6197 			/* not enough to fill a MTU */
6198 			goto need_retran;
6199 		}
6200 		if (IN_FASTRECOVERY(tp->t_flags)) {
6201 			/* Unlikely */
6202 			if (rack->rack_no_prr == 0) {
6203 				if (out + amm <= tp->snd_wnd) {
6204 					rack->r_ctl.rc_prr_sndcnt = amm;
6205 					rack->r_ctl.rc_tlp_new_data = amm;
6206 					rack_log_to_prr(rack, 4, 0, __LINE__);
6207 				}
6208 			} else
6209 				goto need_retran;
6210 		} else {
6211 			/* Set the send-new override */
6212 			if (out + amm <= tp->snd_wnd)
6213 				rack->r_ctl.rc_tlp_new_data = amm;
6214 			else
6215 				goto need_retran;
6216 		}
6217 		rack->r_ctl.rc_tlpsend = NULL;
6218 		counter_u64_add(rack_tlp_newdata, 1);
6219 		goto send;
6220 	}
6221 need_retran:
6222 	/*
6223 	 * Ok we need to arrange the last un-acked segment to be re-sent, or
6224 	 * optionally the first un-acked segment.
6225 	 */
6226 	if (collapsed_win == 0) {
6227 		if (rack_always_send_oldest)
6228 			rsm = TAILQ_FIRST(&rack->r_ctl.rc_tmap);
6229 		else {
6230 			rsm = RB_MAX(rack_rb_tree_head, &rack->r_ctl.rc_mtree);
6231 			if (rsm && (rsm->r_flags & (RACK_ACKED | RACK_HAS_FIN))) {
6232 				rsm = rack_find_high_nonack(rack, rsm);
6233 			}
6234 		}
6235 		if (rsm == NULL) {
6236 #ifdef TCP_BLACKBOX
6237 			tcp_log_dump_tp_logbuf(tp, "nada counter trips", M_NOWAIT, true);
6238 #endif
6239 			goto out;
6240 		}
6241 	} else {
6242 		/*
6243 		 * We must find the last segment
6244 		 * that was acceptable by the client.
6245 		 */
6246 		RB_FOREACH_REVERSE(rsm, rack_rb_tree_head, &rack->r_ctl.rc_mtree) {
6247 			if ((rsm->r_flags & RACK_RWND_COLLAPSED) == 0) {
6248 				/* Found one */
6249 				break;
6250 			}
6251 		}
6252 		if (rsm == NULL) {
6253 			/* None? if so send the first */
6254 			rsm = RB_MIN(rack_rb_tree_head, &rack->r_ctl.rc_mtree);
6255 			if (rsm == NULL) {
6256 #ifdef TCP_BLACKBOX
6257 				tcp_log_dump_tp_logbuf(tp, "nada counter trips", M_NOWAIT, true);
6258 #endif
6259 				goto out;
6260 			}
6261 		}
6262 	}
6263 	if ((rsm->r_end - rsm->r_start) > ctf_fixed_maxseg(tp)) {
6264 		/*
6265 		 * We need to split this the last segment in two.
6266 		 */
6267 		struct rack_sendmap *nrsm;
6268 
6269 		nrsm = rack_alloc_full_limit(rack);
6270 		if (nrsm == NULL) {
6271 			/*
6272 			 * No memory to split, we will just exit and punt
6273 			 * off to the RXT timer.
6274 			 */
6275 			goto out;
6276 		}
6277 		rack_clone_rsm(rack, nrsm, rsm,
6278 			       (rsm->r_end - ctf_fixed_maxseg(tp)));
6279 		rack_log_map_chg(tp, rack, NULL, rsm, nrsm, MAP_SPLIT, 0, __LINE__);
6280 #ifndef INVARIANTS
6281 		(void)RB_INSERT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, nrsm);
6282 #else
6283 		insret = RB_INSERT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, nrsm);
6284 		if (insret != NULL) {
6285 			panic("Insert in rb tree of %p fails ret:%p rack:%p rsm:%p",
6286 			      nrsm, insret, rack, rsm);
6287 		}
6288 #endif
6289 		if (rsm->r_in_tmap) {
6290 			TAILQ_INSERT_AFTER(&rack->r_ctl.rc_tmap, rsm, nrsm, r_tnext);
6291 			nrsm->r_in_tmap = 1;
6292 		}
6293 		rsm = nrsm;
6294 	}
6295 	rack->r_ctl.rc_tlpsend = rsm;
6296 send:
6297 	/* Make sure output path knows we are doing a TLP */
6298 	*doing_tlp = 1;
6299 	rack->r_timer_override = 1;
6300 	rack->r_ctl.rc_hpts_flags &= ~PACE_TMR_TLP;
6301 	return (0);
6302 out:
6303 	rack->r_ctl.rc_hpts_flags &= ~PACE_TMR_TLP;
6304 	return (0);
6305 }
6306 
6307 /*
6308  * Delayed ack Timer, here we simply need to setup the
6309  * ACK_NOW flag and remove the DELACK flag. From there
6310  * the output routine will send the ack out.
6311  *
6312  * We only return 1, saying don't proceed, if all timers
6313  * are stopped (destroyed PCB?).
6314  */
6315 static int
6316 rack_timeout_delack(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cts)
6317 {
6318 	if (tp->t_timers->tt_flags & TT_STOPPED) {
6319 		return (1);
6320 	}
6321 	rack_log_to_event(rack, RACK_TO_FRM_DELACK, NULL);
6322 	tp->t_flags &= ~TF_DELACK;
6323 	tp->t_flags |= TF_ACKNOW;
6324 	KMOD_TCPSTAT_INC(tcps_delack);
6325 	rack->r_ctl.rc_hpts_flags &= ~PACE_TMR_DELACK;
6326 	return (0);
6327 }
6328 
6329 /*
6330  * Persists timer, here we simply send the
6331  * same thing as a keepalive will.
6332  * the one byte send.
6333  *
6334  * We only return 1, saying don't proceed, if all timers
6335  * are stopped (destroyed PCB?).
6336  */
6337 static int
6338 rack_timeout_persist(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cts)
6339 {
6340 	struct tcptemp *t_template;
6341 #ifdef INVARIANTS
6342 	struct inpcb *inp = tp->t_inpcb;
6343 #endif
6344 	int32_t retval = 1;
6345 
6346 	if (tp->t_timers->tt_flags & TT_STOPPED) {
6347 		return (1);
6348 	}
6349 	if (rack->rc_in_persist == 0)
6350 		return (0);
6351 	if (ctf_progress_timeout_check(tp, false)) {
6352 		tcp_log_end_status(tp, TCP_EI_STATUS_PERSIST_MAX);
6353 		rack_log_progress_event(rack, tp, tick, PROGRESS_DROP, __LINE__);
6354 		counter_u64_add(rack_persists_lost_ends, rack->r_ctl.persist_lost_ends);
6355 		return (-ETIMEDOUT);	/* tcp_drop() */
6356 	}
6357 	KASSERT(inp != NULL, ("%s: tp %p tp->t_inpcb == NULL", __func__, tp));
6358 	/*
6359 	 * Persistence timer into zero window. Force a byte to be output, if
6360 	 * possible.
6361 	 */
6362 	KMOD_TCPSTAT_INC(tcps_persisttimeo);
6363 	/*
6364 	 * Hack: if the peer is dead/unreachable, we do not time out if the
6365 	 * window is closed.  After a full backoff, drop the connection if
6366 	 * the idle time (no responses to probes) reaches the maximum
6367 	 * backoff that we would use if retransmitting.
6368 	 */
6369 	if (tp->t_rxtshift == TCP_MAXRXTSHIFT &&
6370 	    (ticks - tp->t_rcvtime >= tcp_maxpersistidle ||
6371 	     TICKS_2_USEC(ticks - tp->t_rcvtime) >= RACK_REXMTVAL(tp) * tcp_totbackoff)) {
6372 		KMOD_TCPSTAT_INC(tcps_persistdrop);
6373 		tcp_log_end_status(tp, TCP_EI_STATUS_PERSIST_MAX);
6374 		counter_u64_add(rack_persists_lost_ends, rack->r_ctl.persist_lost_ends);
6375 		retval = -ETIMEDOUT;	/* tcp_drop() */
6376 		goto out;
6377 	}
6378 	if ((sbavail(&rack->rc_inp->inp_socket->so_snd) == 0) &&
6379 	    tp->snd_una == tp->snd_max)
6380 		rack_exit_persist(tp, rack, cts);
6381 	rack->r_ctl.rc_hpts_flags &= ~PACE_TMR_PERSIT;
6382 	/*
6383 	 * If the user has closed the socket then drop a persisting
6384 	 * connection after a much reduced timeout.
6385 	 */
6386 	if (tp->t_state > TCPS_CLOSE_WAIT &&
6387 	    (ticks - tp->t_rcvtime) >= TCPTV_PERSMAX) {
6388 		KMOD_TCPSTAT_INC(tcps_persistdrop);
6389 		tcp_log_end_status(tp, TCP_EI_STATUS_PERSIST_MAX);
6390 		counter_u64_add(rack_persists_lost_ends, rack->r_ctl.persist_lost_ends);
6391 		retval = -ETIMEDOUT;	/* tcp_drop() */
6392 		goto out;
6393 	}
6394 	t_template = tcpip_maketemplate(rack->rc_inp);
6395 	if (t_template) {
6396 		/* only set it if we were answered */
6397 		if (rack->forced_ack == 0) {
6398 			rack->forced_ack = 1;
6399 			rack->r_ctl.forced_ack_ts = tcp_get_usecs(NULL);
6400 		} else {
6401 			rack->probe_not_answered = 1;
6402 			counter_u64_add(rack_persists_loss, 1);
6403 			rack->r_ctl.persist_lost_ends++;
6404 		}
6405 		counter_u64_add(rack_persists_sends, 1);
6406 		tcp_respond(tp, t_template->tt_ipgen,
6407 			    &t_template->tt_t, (struct mbuf *)NULL,
6408 			    tp->rcv_nxt, tp->snd_una - 1, 0);
6409 		/* This sends an ack */
6410 		if (tp->t_flags & TF_DELACK)
6411 			tp->t_flags &= ~TF_DELACK;
6412 		free(t_template, M_TEMP);
6413 	}
6414 	if (tp->t_rxtshift < TCP_MAXRXTSHIFT)
6415 		tp->t_rxtshift++;
6416 out:
6417 	rack_log_to_event(rack, RACK_TO_FRM_PERSIST, NULL);
6418 	rack_start_hpts_timer(rack, tp, cts,
6419 			      0, 0, 0);
6420 	return (retval);
6421 }
6422 
6423 /*
6424  * If a keepalive goes off, we had no other timers
6425  * happening. We always return 1 here since this
6426  * routine either drops the connection or sends
6427  * out a segment with respond.
6428  */
6429 static int
6430 rack_timeout_keepalive(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cts)
6431 {
6432 	struct tcptemp *t_template;
6433 	struct inpcb *inp;
6434 
6435 	if (tp->t_timers->tt_flags & TT_STOPPED) {
6436 		return (1);
6437 	}
6438 	rack->r_ctl.rc_hpts_flags &= ~PACE_TMR_KEEP;
6439 	inp = tp->t_inpcb;
6440 	rack_log_to_event(rack, RACK_TO_FRM_KEEP, NULL);
6441 	/*
6442 	 * Keep-alive timer went off; send something or drop connection if
6443 	 * idle for too long.
6444 	 */
6445 	KMOD_TCPSTAT_INC(tcps_keeptimeo);
6446 	if (tp->t_state < TCPS_ESTABLISHED)
6447 		goto dropit;
6448 	if ((V_tcp_always_keepalive || inp->inp_socket->so_options & SO_KEEPALIVE) &&
6449 	    tp->t_state <= TCPS_CLOSING) {
6450 		if (ticks - tp->t_rcvtime >= TP_KEEPIDLE(tp) + TP_MAXIDLE(tp))
6451 			goto dropit;
6452 		/*
6453 		 * Send a packet designed to force a response if the peer is
6454 		 * up and reachable: either an ACK if the connection is
6455 		 * still alive, or an RST if the peer has closed the
6456 		 * connection due to timeout or reboot. Using sequence
6457 		 * number tp->snd_una-1 causes the transmitted zero-length
6458 		 * segment to lie outside the receive window; by the
6459 		 * protocol spec, this requires the correspondent TCP to
6460 		 * respond.
6461 		 */
6462 		KMOD_TCPSTAT_INC(tcps_keepprobe);
6463 		t_template = tcpip_maketemplate(inp);
6464 		if (t_template) {
6465 			if (rack->forced_ack == 0) {
6466 				rack->forced_ack = 1;
6467 				rack->r_ctl.forced_ack_ts = tcp_get_usecs(NULL);
6468 			} else {
6469 				rack->probe_not_answered = 1;
6470 			}
6471 			tcp_respond(tp, t_template->tt_ipgen,
6472 			    &t_template->tt_t, (struct mbuf *)NULL,
6473 			    tp->rcv_nxt, tp->snd_una - 1, 0);
6474 			free(t_template, M_TEMP);
6475 		}
6476 	}
6477 	rack_start_hpts_timer(rack, tp, cts, 0, 0, 0);
6478 	return (1);
6479 dropit:
6480 	KMOD_TCPSTAT_INC(tcps_keepdrops);
6481 	tcp_log_end_status(tp, TCP_EI_STATUS_KEEP_MAX);
6482 	return (-ETIMEDOUT);	/* tcp_drop() */
6483 }
6484 
6485 /*
6486  * Retransmit helper function, clear up all the ack
6487  * flags and take care of important book keeping.
6488  */
6489 static void
6490 rack_remxt_tmr(struct tcpcb *tp)
6491 {
6492 	/*
6493 	 * The retransmit timer went off, all sack'd blocks must be
6494 	 * un-acked.
6495 	 */
6496 	struct rack_sendmap *rsm, *trsm = NULL;
6497 	struct tcp_rack *rack;
6498 
6499 	rack = (struct tcp_rack *)tp->t_fb_ptr;
6500 	rack_timer_cancel(tp, rack, tcp_get_usecs(NULL), __LINE__);
6501 	rack_log_to_event(rack, RACK_TO_FRM_TMR, NULL);
6502 	if (rack->r_state && (rack->r_state != tp->t_state))
6503 		rack_set_state(tp, rack);
6504 	/*
6505 	 * Ideally we would like to be able to
6506 	 * mark SACK-PASS on anything not acked here.
6507 	 *
6508 	 * However, if we do that we would burst out
6509 	 * all that data 1ms apart. This would be unwise,
6510 	 * so for now we will just let the normal rxt timer
6511 	 * and tlp timer take care of it.
6512 	 *
6513 	 * Also we really need to stick them back in sequence
6514 	 * order. This way we send in the proper order and any
6515 	 * sacks that come floating in will "re-ack" the data.
6516 	 * To do this we zap the tmap with an INIT and then
6517 	 * walk through and place every rsm in the RB tree
6518 	 * back in its seq ordered place.
6519 	 */
6520 	TAILQ_INIT(&rack->r_ctl.rc_tmap);
6521 	RB_FOREACH(rsm, rack_rb_tree_head, &rack->r_ctl.rc_mtree) {
6522 		rsm->r_dupack = 0;
6523 		rack_log_retran_reason(rack, rsm, __LINE__, 0, 2);
6524 		/* We must re-add it back to the tlist */
6525 		if (trsm == NULL) {
6526 			TAILQ_INSERT_HEAD(&rack->r_ctl.rc_tmap, rsm, r_tnext);
6527 		} else {
6528 			TAILQ_INSERT_AFTER(&rack->r_ctl.rc_tmap, trsm, rsm, r_tnext);
6529 		}
6530 		rsm->r_in_tmap = 1;
6531 		trsm = rsm;
6532 		if (rsm->r_flags & RACK_ACKED)
6533 			rsm->r_flags |= RACK_WAS_ACKED;
6534 		rsm->r_flags &= ~(RACK_ACKED | RACK_SACK_PASSED | RACK_WAS_SACKPASS | RACK_RWND_COLLAPSED);
6535 		rsm->r_flags |= RACK_MUST_RXT;
6536 	}
6537 	/* Clear the count (we just un-acked them) */
6538 	rack->r_ctl.rc_last_timeout_snduna = tp->snd_una;
6539 	rack->r_ctl.rc_sacked = 0;
6540 	rack->r_ctl.rc_sacklast = NULL;
6541 	rack->r_ctl.rc_agg_delayed = 0;
6542 	rack->r_early = 0;
6543 	rack->r_ctl.rc_agg_early = 0;
6544 	rack->r_late = 0;
6545 	/* Clear the tlp rtx mark */
6546 	rack->r_ctl.rc_resend = RB_MIN(rack_rb_tree_head, &rack->r_ctl.rc_mtree);
6547 	if (rack->r_ctl.rc_resend != NULL)
6548 		rack->r_ctl.rc_resend->r_flags |= RACK_TO_REXT;
6549 	rack->r_ctl.rc_prr_sndcnt = 0;
6550 	rack_log_to_prr(rack, 6, 0, __LINE__);
6551 	rack->r_timer_override = 1;
6552 	if ((((tp->t_flags & TF_SACK_PERMIT) == 0)
6553 #ifdef NETFLIX_EXP_DETECTION
6554 	    || (rack->sack_attack_disable != 0)
6555 #endif
6556 		    ) && ((tp->t_flags & TF_SENTFIN) == 0)) {
6557 		/*
6558 		 * For non-sack customers new data
6559 		 * needs to go out as retransmits until
6560 		 * we retransmit up to snd_max.
6561 		 */
6562 		rack->r_must_retran = 1;
6563 		rack->r_ctl.rc_out_at_rto = ctf_flight_size(rack->rc_tp,
6564 						rack->r_ctl.rc_sacked);
6565 	}
6566 	rack->r_ctl.rc_snd_max_at_rto = tp->snd_max;
6567 }
6568 
6569 static void
6570 rack_convert_rtts(struct tcpcb *tp)
6571 {
6572 	if (tp->t_srtt > 1) {
6573 		uint32_t val, frac;
6574 
6575 		val = tp->t_srtt >> TCP_RTT_SHIFT;
6576 		frac = tp->t_srtt & 0x1f;
6577 		tp->t_srtt = TICKS_2_USEC(val);
6578 		/*
6579 		 * frac is the fractional part of the srtt (if any)
6580 		 * but its in ticks and every bit represents
6581 		 * 1/32nd of a hz.
6582 		 */
6583 		if (frac) {
6584 			if (hz == 1000) {
6585 				frac = (((uint64_t)frac * (uint64_t)HPTS_USEC_IN_MSEC) / (uint64_t)TCP_RTT_SCALE);
6586 			} else {
6587 				frac = (((uint64_t)frac * (uint64_t)HPTS_USEC_IN_SEC) / ((uint64_t)(hz) * (uint64_t)TCP_RTT_SCALE));
6588 			}
6589 			tp->t_srtt += frac;
6590 		}
6591 	}
6592 	if (tp->t_rttvar) {
6593 		uint32_t val, frac;
6594 
6595 		val = tp->t_rttvar >> TCP_RTTVAR_SHIFT;
6596 		frac = tp->t_rttvar & 0x1f;
6597 		tp->t_rttvar = TICKS_2_USEC(val);
6598 		/*
6599 		 * frac is the fractional part of the srtt (if any)
6600 		 * but its in ticks and every bit represents
6601 		 * 1/32nd of a hz.
6602 		 */
6603 		if (frac) {
6604 			if (hz == 1000) {
6605 				frac = (((uint64_t)frac * (uint64_t)HPTS_USEC_IN_MSEC) / (uint64_t)TCP_RTT_SCALE);
6606 			} else {
6607 				frac = (((uint64_t)frac * (uint64_t)HPTS_USEC_IN_SEC) / ((uint64_t)(hz) * (uint64_t)TCP_RTT_SCALE));
6608 			}
6609 			tp->t_rttvar += frac;
6610 		}
6611 	}
6612 	tp->t_rxtcur = RACK_REXMTVAL(tp);
6613 	if (TCPS_HAVEESTABLISHED(tp->t_state)) {
6614 		tp->t_rxtcur += TICKS_2_USEC(tcp_rexmit_slop);
6615 	}
6616 	if (tp->t_rxtcur > rack_rto_max) {
6617 		tp->t_rxtcur = rack_rto_max;
6618 	}
6619 }
6620 
6621 static void
6622 rack_cc_conn_init(struct tcpcb *tp)
6623 {
6624 	struct tcp_rack *rack;
6625 	uint32_t srtt;
6626 
6627 	rack = (struct tcp_rack *)tp->t_fb_ptr;
6628 	srtt = tp->t_srtt;
6629 	cc_conn_init(tp);
6630 	/*
6631 	 * Now convert to rack's internal format,
6632 	 * if required.
6633 	 */
6634 	if ((srtt == 0) && (tp->t_srtt != 0))
6635 		rack_convert_rtts(tp);
6636 	/*
6637 	 * We want a chance to stay in slowstart as
6638 	 * we create a connection. TCP spec says that
6639 	 * initially ssthresh is infinite. For our
6640 	 * purposes that is the snd_wnd.
6641 	 */
6642 	if (tp->snd_ssthresh < tp->snd_wnd) {
6643 		tp->snd_ssthresh = tp->snd_wnd;
6644 	}
6645 	/*
6646 	 * We also want to assure a IW worth of
6647 	 * data can get inflight.
6648 	 */
6649 	if (rc_init_window(rack) < tp->snd_cwnd)
6650 		tp->snd_cwnd = rc_init_window(rack);
6651 }
6652 
6653 /*
6654  * Re-transmit timeout! If we drop the PCB we will return 1, otherwise
6655  * we will setup to retransmit the lowest seq number outstanding.
6656  */
6657 static int
6658 rack_timeout_rxt(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cts)
6659 {
6660 	int32_t rexmt;
6661 	int32_t retval = 0;
6662 	bool isipv6;
6663 
6664 	if (tp->t_timers->tt_flags & TT_STOPPED) {
6665 		return (1);
6666 	}
6667 	if ((tp->t_flags & TF_GPUTINPROG) &&
6668 	    (tp->t_rxtshift)) {
6669 		/*
6670 		 * We have had a second timeout
6671 		 * measurements on successive rxt's are not profitable.
6672 		 * It is unlikely to be of any use (the network is
6673 		 * broken or the client went away).
6674 		 */
6675 		tp->t_flags &= ~TF_GPUTINPROG;
6676 		rack_log_pacing_delay_calc(rack, (tp->gput_ack - tp->gput_seq) /*flex2*/,
6677 					   rack->r_ctl.rc_gp_srtt /*flex1*/,
6678 					   tp->gput_seq,
6679 					   0, 0, 18, __LINE__, NULL, 0);
6680 	}
6681 	if (ctf_progress_timeout_check(tp, false)) {
6682 		tcp_log_end_status(tp, TCP_EI_STATUS_RETRAN);
6683 		rack_log_progress_event(rack, tp, tick, PROGRESS_DROP, __LINE__);
6684 		return (-ETIMEDOUT);	/* tcp_drop() */
6685 	}
6686 	rack->r_ctl.rc_hpts_flags &= ~PACE_TMR_RXT;
6687 	rack->r_ctl.retran_during_recovery = 0;
6688 	rack->rc_ack_required = 1;
6689 	rack->r_ctl.dsack_byte_cnt = 0;
6690 	if (IN_FASTRECOVERY(tp->t_flags))
6691 		tp->t_flags |= TF_WASFRECOVERY;
6692 	else
6693 		tp->t_flags &= ~TF_WASFRECOVERY;
6694 	if (IN_CONGRECOVERY(tp->t_flags))
6695 		tp->t_flags |= TF_WASCRECOVERY;
6696 	else
6697 		tp->t_flags &= ~TF_WASCRECOVERY;
6698 	if (TCPS_HAVEESTABLISHED(tp->t_state) &&
6699 	    (tp->snd_una == tp->snd_max)) {
6700 		/* Nothing outstanding .. nothing to do */
6701 		return (0);
6702 	}
6703 	if (rack->r_ctl.dsack_persist) {
6704 		rack->r_ctl.dsack_persist--;
6705 		if (rack->r_ctl.num_dsack && (rack->r_ctl.dsack_persist == 0)) {
6706 			rack->r_ctl.num_dsack = 0;
6707 		}
6708 		rack_log_dsack_event(rack, 1, __LINE__, 0, 0);
6709 	}
6710 	/*
6711 	 * Rack can only run one timer  at a time, so we cannot
6712 	 * run a KEEPINIT (gating SYN sending) and a retransmit
6713 	 * timer for the SYN. So if we are in a front state and
6714 	 * have a KEEPINIT timer we need to check the first transmit
6715 	 * against now to see if we have exceeded the KEEPINIT time
6716 	 * (if one is set).
6717 	 */
6718 	if ((TCPS_HAVEESTABLISHED(tp->t_state) == 0) &&
6719 	    (TP_KEEPINIT(tp) != 0)) {
6720 		struct rack_sendmap *rsm;
6721 
6722 		rsm = RB_MIN(rack_rb_tree_head, &rack->r_ctl.rc_mtree);
6723 		if (rsm) {
6724 			/* Ok we have something outstanding to test keepinit with */
6725 			if ((TSTMP_GT(cts, (uint32_t)rsm->r_tim_lastsent[0])) &&
6726 			    ((cts - (uint32_t)rsm->r_tim_lastsent[0]) >= TICKS_2_USEC(TP_KEEPINIT(tp)))) {
6727 				/* We have exceeded the KEEPINIT time */
6728 				tcp_log_end_status(tp, TCP_EI_STATUS_KEEP_MAX);
6729 				goto drop_it;
6730 			}
6731 		}
6732 	}
6733 	/*
6734 	 * Retransmission timer went off.  Message has not been acked within
6735 	 * retransmit interval.  Back off to a longer retransmit interval
6736 	 * and retransmit one segment.
6737 	 */
6738 	rack_remxt_tmr(tp);
6739 	if ((rack->r_ctl.rc_resend == NULL) ||
6740 	    ((rack->r_ctl.rc_resend->r_flags & RACK_RWND_COLLAPSED) == 0)) {
6741 		/*
6742 		 * If the rwnd collapsed on
6743 		 * the one we are retransmitting
6744 		 * it does not count against the
6745 		 * rxt count.
6746 		 */
6747 		tp->t_rxtshift++;
6748 	}
6749 	if (tp->t_rxtshift > TCP_MAXRXTSHIFT) {
6750 		tcp_log_end_status(tp, TCP_EI_STATUS_RETRAN);
6751 drop_it:
6752 		tp->t_rxtshift = TCP_MAXRXTSHIFT;
6753 		KMOD_TCPSTAT_INC(tcps_timeoutdrop);
6754 		/* XXXGL: previously t_softerror was casted to uint16_t */
6755 		MPASS(tp->t_softerror >= 0);
6756 		retval = tp->t_softerror ? -tp->t_softerror : -ETIMEDOUT;
6757 		goto out;	/* tcp_drop() */
6758 	}
6759 	if (tp->t_state == TCPS_SYN_SENT) {
6760 		/*
6761 		 * If the SYN was retransmitted, indicate CWND to be limited
6762 		 * to 1 segment in cc_conn_init().
6763 		 */
6764 		tp->snd_cwnd = 1;
6765 	} else if (tp->t_rxtshift == 1) {
6766 		/*
6767 		 * first retransmit; record ssthresh and cwnd so they can be
6768 		 * recovered if this turns out to be a "bad" retransmit. A
6769 		 * retransmit is considered "bad" if an ACK for this segment
6770 		 * is received within RTT/2 interval; the assumption here is
6771 		 * that the ACK was already in flight.  See "On Estimating
6772 		 * End-to-End Network Path Properties" by Allman and Paxson
6773 		 * for more details.
6774 		 */
6775 		tp->snd_cwnd_prev = tp->snd_cwnd;
6776 		tp->snd_ssthresh_prev = tp->snd_ssthresh;
6777 		tp->snd_recover_prev = tp->snd_recover;
6778 		tp->t_badrxtwin = ticks + (USEC_2_TICKS(tp->t_srtt)/2);
6779 		tp->t_flags |= TF_PREVVALID;
6780 	} else if ((tp->t_flags & TF_RCVD_TSTMP) == 0)
6781 		tp->t_flags &= ~TF_PREVVALID;
6782 	KMOD_TCPSTAT_INC(tcps_rexmttimeo);
6783 	if ((tp->t_state == TCPS_SYN_SENT) ||
6784 	    (tp->t_state == TCPS_SYN_RECEIVED))
6785 		rexmt = RACK_INITIAL_RTO * tcp_backoff[tp->t_rxtshift];
6786 	else
6787 		rexmt = max(rack_rto_min, (tp->t_srtt + (tp->t_rttvar << 2))) * tcp_backoff[tp->t_rxtshift];
6788 
6789 	RACK_TCPT_RANGESET(tp->t_rxtcur, rexmt,
6790 	   max(rack_rto_min, rexmt), rack_rto_max, rack->r_ctl.timer_slop);
6791 	/*
6792 	 * We enter the path for PLMTUD if connection is established or, if
6793 	 * connection is FIN_WAIT_1 status, reason for the last is that if
6794 	 * amount of data we send is very small, we could send it in couple
6795 	 * of packets and process straight to FIN. In that case we won't
6796 	 * catch ESTABLISHED state.
6797 	 */
6798 #ifdef INET6
6799 	isipv6 = (tp->t_inpcb->inp_vflag & INP_IPV6) ? true : false;
6800 #else
6801 	isipv6 = false;
6802 #endif
6803 	if (((V_tcp_pmtud_blackhole_detect == 1) ||
6804 	    (V_tcp_pmtud_blackhole_detect == 2 && !isipv6) ||
6805 	    (V_tcp_pmtud_blackhole_detect == 3 && isipv6)) &&
6806 	    ((tp->t_state == TCPS_ESTABLISHED) ||
6807 	    (tp->t_state == TCPS_FIN_WAIT_1))) {
6808 		/*
6809 		 * Idea here is that at each stage of mtu probe (usually,
6810 		 * 1448 -> 1188 -> 524) should be given 2 chances to recover
6811 		 * before further clamping down. 'tp->t_rxtshift % 2 == 0'
6812 		 * should take care of that.
6813 		 */
6814 		if (((tp->t_flags2 & (TF2_PLPMTU_PMTUD | TF2_PLPMTU_MAXSEGSNT)) ==
6815 		    (TF2_PLPMTU_PMTUD | TF2_PLPMTU_MAXSEGSNT)) &&
6816 		    (tp->t_rxtshift >= 2 && tp->t_rxtshift < 6 &&
6817 		    tp->t_rxtshift % 2 == 0)) {
6818 			/*
6819 			 * Enter Path MTU Black-hole Detection mechanism: -
6820 			 * Disable Path MTU Discovery (IP "DF" bit). -
6821 			 * Reduce MTU to lower value than what we negotiated
6822 			 * with peer.
6823 			 */
6824 			if ((tp->t_flags2 & TF2_PLPMTU_BLACKHOLE) == 0) {
6825 				/* Record that we may have found a black hole. */
6826 				tp->t_flags2 |= TF2_PLPMTU_BLACKHOLE;
6827 				/* Keep track of previous MSS. */
6828 				tp->t_pmtud_saved_maxseg = tp->t_maxseg;
6829 			}
6830 
6831 			/*
6832 			 * Reduce the MSS to blackhole value or to the
6833 			 * default in an attempt to retransmit.
6834 			 */
6835 #ifdef INET6
6836 			if (isipv6 &&
6837 			    tp->t_maxseg > V_tcp_v6pmtud_blackhole_mss) {
6838 				/* Use the sysctl tuneable blackhole MSS. */
6839 				tp->t_maxseg = V_tcp_v6pmtud_blackhole_mss;
6840 				KMOD_TCPSTAT_INC(tcps_pmtud_blackhole_activated);
6841 			} else if (isipv6) {
6842 				/* Use the default MSS. */
6843 				tp->t_maxseg = V_tcp_v6mssdflt;
6844 				/*
6845 				 * Disable Path MTU Discovery when we switch
6846 				 * to minmss.
6847 				 */
6848 				tp->t_flags2 &= ~TF2_PLPMTU_PMTUD;
6849 				KMOD_TCPSTAT_INC(tcps_pmtud_blackhole_activated_min_mss);
6850 			}
6851 #endif
6852 #if defined(INET6) && defined(INET)
6853 			else
6854 #endif
6855 #ifdef INET
6856 			if (tp->t_maxseg > V_tcp_pmtud_blackhole_mss) {
6857 				/* Use the sysctl tuneable blackhole MSS. */
6858 				tp->t_maxseg = V_tcp_pmtud_blackhole_mss;
6859 				KMOD_TCPSTAT_INC(tcps_pmtud_blackhole_activated);
6860 			} else {
6861 				/* Use the default MSS. */
6862 				tp->t_maxseg = V_tcp_mssdflt;
6863 				/*
6864 				 * Disable Path MTU Discovery when we switch
6865 				 * to minmss.
6866 				 */
6867 				tp->t_flags2 &= ~TF2_PLPMTU_PMTUD;
6868 				KMOD_TCPSTAT_INC(tcps_pmtud_blackhole_activated_min_mss);
6869 			}
6870 #endif
6871 		} else {
6872 			/*
6873 			 * If further retransmissions are still unsuccessful
6874 			 * with a lowered MTU, maybe this isn't a blackhole
6875 			 * and we restore the previous MSS and blackhole
6876 			 * detection flags. The limit '6' is determined by
6877 			 * giving each probe stage (1448, 1188, 524) 2
6878 			 * chances to recover.
6879 			 */
6880 			if ((tp->t_flags2 & TF2_PLPMTU_BLACKHOLE) &&
6881 			    (tp->t_rxtshift >= 6)) {
6882 				tp->t_flags2 |= TF2_PLPMTU_PMTUD;
6883 				tp->t_flags2 &= ~TF2_PLPMTU_BLACKHOLE;
6884 				tp->t_maxseg = tp->t_pmtud_saved_maxseg;
6885 				KMOD_TCPSTAT_INC(tcps_pmtud_blackhole_failed);
6886 			}
6887 		}
6888 	}
6889 	/*
6890 	 * Disable RFC1323 and SACK if we haven't got any response to
6891 	 * our third SYN to work-around some broken terminal servers
6892 	 * (most of which have hopefully been retired) that have bad VJ
6893 	 * header compression code which trashes TCP segments containing
6894 	 * unknown-to-them TCP options.
6895 	 */
6896 	if (tcp_rexmit_drop_options && (tp->t_state == TCPS_SYN_SENT) &&
6897 	    (tp->t_rxtshift == 3))
6898 		tp->t_flags &= ~(TF_REQ_SCALE|TF_REQ_TSTMP|TF_SACK_PERMIT);
6899 	/*
6900 	 * If we backed off this far, our srtt estimate is probably bogus.
6901 	 * Clobber it so we'll take the next rtt measurement as our srtt;
6902 	 * move the current srtt into rttvar to keep the current retransmit
6903 	 * times until then.
6904 	 */
6905 	if (tp->t_rxtshift > TCP_MAXRXTSHIFT / 4) {
6906 #ifdef INET6
6907 		if ((tp->t_inpcb->inp_vflag & INP_IPV6) != 0)
6908 			in6_losing(tp->t_inpcb);
6909 		else
6910 #endif
6911 			in_losing(tp->t_inpcb);
6912 		tp->t_rttvar += tp->t_srtt;
6913 		tp->t_srtt = 0;
6914 	}
6915 	sack_filter_clear(&rack->r_ctl.rack_sf, tp->snd_una);
6916 	tp->snd_recover = tp->snd_max;
6917 	tp->t_flags |= TF_ACKNOW;
6918 	tp->t_rtttime = 0;
6919 	rack_cong_signal(tp, CC_RTO, tp->snd_una, __LINE__);
6920 out:
6921 	return (retval);
6922 }
6923 
6924 static int
6925 rack_process_timers(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cts, uint8_t hpts_calling, uint8_t *doing_tlp)
6926 {
6927 	int32_t ret = 0;
6928 	int32_t timers = (rack->r_ctl.rc_hpts_flags & PACE_TMR_MASK);
6929 
6930 	if ((tp->t_state >= TCPS_FIN_WAIT_1) &&
6931 	    (tp->t_flags & TF_GPUTINPROG)) {
6932 		/*
6933 		 * We have a goodput in progress
6934 		 * and we have entered a late state.
6935 		 * Do we have enough data in the sb
6936 		 * to handle the GPUT request?
6937 		 */
6938 		uint32_t bytes;
6939 
6940 		bytes = tp->gput_ack - tp->gput_seq;
6941 		if (SEQ_GT(tp->gput_seq, tp->snd_una))
6942 			bytes += tp->gput_seq - tp->snd_una;
6943 		if (bytes > sbavail(&tp->t_inpcb->inp_socket->so_snd)) {
6944 			/*
6945 			 * There are not enough bytes in the socket
6946 			 * buffer that have been sent to cover this
6947 			 * measurement. Cancel it.
6948 			 */
6949 			rack_log_pacing_delay_calc(rack, (tp->gput_ack - tp->gput_seq) /*flex2*/,
6950 						   rack->r_ctl.rc_gp_srtt /*flex1*/,
6951 						   tp->gput_seq,
6952 						   0, 0, 18, __LINE__, NULL, 0);
6953 			tp->t_flags &= ~TF_GPUTINPROG;
6954 		}
6955 	}
6956 	if (timers == 0) {
6957 		return (0);
6958 	}
6959 	if (tp->t_state == TCPS_LISTEN) {
6960 		/* no timers on listen sockets */
6961 		if (rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT)
6962 			return (0);
6963 		return (1);
6964 	}
6965 	if ((timers & PACE_TMR_RACK) &&
6966 	    rack->rc_on_min_to) {
6967 		/*
6968 		 * For the rack timer when we
6969 		 * are on a min-timeout (which means rrr_conf = 3)
6970 		 * we don't want to check the timer. It may
6971 		 * be going off for a pace and thats ok we
6972 		 * want to send the retransmit (if its ready).
6973 		 *
6974 		 * If its on a normal rack timer (non-min) then
6975 		 * we will check if its expired.
6976 		 */
6977 		goto skip_time_check;
6978 	}
6979 	if (TSTMP_LT(cts, rack->r_ctl.rc_timer_exp)) {
6980 		uint32_t left;
6981 
6982 		if (rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT) {
6983 			ret = -1;
6984 			rack_log_to_processing(rack, cts, ret, 0);
6985 			return (0);
6986 		}
6987 		if (hpts_calling == 0) {
6988 			/*
6989 			 * A user send or queued mbuf (sack) has called us? We
6990 			 * return 0 and let the pacing guards
6991 			 * deal with it if they should or
6992 			 * should not cause a send.
6993 			 */
6994 			ret = -2;
6995 			rack_log_to_processing(rack, cts, ret, 0);
6996 			return (0);
6997 		}
6998 		/*
6999 		 * Ok our timer went off early and we are not paced false
7000 		 * alarm, go back to sleep.
7001 		 */
7002 		ret = -3;
7003 		left = rack->r_ctl.rc_timer_exp - cts;
7004 		tcp_hpts_insert(tp->t_inpcb, HPTS_MS_TO_SLOTS(left));
7005 		rack_log_to_processing(rack, cts, ret, left);
7006 		return (1);
7007 	}
7008 skip_time_check:
7009 	rack->rc_tmr_stopped = 0;
7010 	rack->r_ctl.rc_hpts_flags &= ~PACE_TMR_MASK;
7011 	if (timers & PACE_TMR_DELACK) {
7012 		ret = rack_timeout_delack(tp, rack, cts);
7013 	} else if (timers & PACE_TMR_RACK) {
7014 		rack->r_ctl.rc_tlp_rxt_last_time = cts;
7015 		rack->r_fast_output = 0;
7016 		ret = rack_timeout_rack(tp, rack, cts);
7017 	} else if (timers & PACE_TMR_TLP) {
7018 		rack->r_ctl.rc_tlp_rxt_last_time = cts;
7019 		ret = rack_timeout_tlp(tp, rack, cts, doing_tlp);
7020 	} else if (timers & PACE_TMR_RXT) {
7021 		rack->r_ctl.rc_tlp_rxt_last_time = cts;
7022 		rack->r_fast_output = 0;
7023 		ret = rack_timeout_rxt(tp, rack, cts);
7024 	} else if (timers & PACE_TMR_PERSIT) {
7025 		ret = rack_timeout_persist(tp, rack, cts);
7026 	} else if (timers & PACE_TMR_KEEP) {
7027 		ret = rack_timeout_keepalive(tp, rack, cts);
7028 	}
7029 	rack_log_to_processing(rack, cts, ret, timers);
7030 	return (ret);
7031 }
7032 
7033 static void
7034 rack_timer_cancel(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cts, int line)
7035 {
7036 	struct timeval tv;
7037 	uint32_t us_cts, flags_on_entry;
7038 	uint8_t hpts_removed = 0;
7039 
7040 	flags_on_entry = rack->r_ctl.rc_hpts_flags;
7041 	us_cts = tcp_get_usecs(&tv);
7042 	if ((rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT) &&
7043 	    ((TSTMP_GEQ(us_cts, rack->r_ctl.rc_last_output_to)) ||
7044 	     ((tp->snd_max - tp->snd_una) == 0))) {
7045 		tcp_hpts_remove(rack->rc_inp);
7046 		hpts_removed = 1;
7047 		/* If we were not delayed cancel out the flag. */
7048 		if ((tp->snd_max - tp->snd_una) == 0)
7049 			rack->r_ctl.rc_hpts_flags &= ~PACE_PKT_OUTPUT;
7050 		rack_log_to_cancel(rack, hpts_removed, line, us_cts, &tv, flags_on_entry);
7051 	}
7052 	if (rack->r_ctl.rc_hpts_flags & PACE_TMR_MASK) {
7053 		rack->rc_tmr_stopped = rack->r_ctl.rc_hpts_flags & PACE_TMR_MASK;
7054 		if (tcp_in_hpts(rack->rc_inp) &&
7055 		    ((rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT) == 0)) {
7056 			/*
7057 			 * Canceling timer's when we have no output being
7058 			 * paced. We also must remove ourselves from the
7059 			 * hpts.
7060 			 */
7061 			tcp_hpts_remove(rack->rc_inp);
7062 			hpts_removed = 1;
7063 		}
7064 		rack->r_ctl.rc_hpts_flags &= ~(PACE_TMR_MASK);
7065 	}
7066 	if (hpts_removed == 0)
7067 		rack_log_to_cancel(rack, hpts_removed, line, us_cts, &tv, flags_on_entry);
7068 }
7069 
7070 static void
7071 rack_timer_stop(struct tcpcb *tp, uint32_t timer_type)
7072 {
7073 	return;
7074 }
7075 
7076 static int
7077 rack_stopall(struct tcpcb *tp)
7078 {
7079 	struct tcp_rack *rack;
7080 	rack = (struct tcp_rack *)tp->t_fb_ptr;
7081 	rack->t_timers_stopped = 1;
7082 	return (0);
7083 }
7084 
7085 static void
7086 rack_timer_activate(struct tcpcb *tp, uint32_t timer_type, uint32_t delta)
7087 {
7088 	return;
7089 }
7090 
7091 static int
7092 rack_timer_active(struct tcpcb *tp, uint32_t timer_type)
7093 {
7094 	return (0);
7095 }
7096 
7097 static void
7098 rack_stop_all_timers(struct tcpcb *tp)
7099 {
7100 	struct tcp_rack *rack;
7101 
7102 	/*
7103 	 * Assure no timers are running.
7104 	 */
7105 	if (tcp_timer_active(tp, TT_PERSIST)) {
7106 		/* We enter in persists, set the flag appropriately */
7107 		rack = (struct tcp_rack *)tp->t_fb_ptr;
7108 		rack->rc_in_persist = 1;
7109 	}
7110 	tcp_timer_suspend(tp, TT_PERSIST);
7111 	tcp_timer_suspend(tp, TT_REXMT);
7112 	tcp_timer_suspend(tp, TT_KEEP);
7113 	tcp_timer_suspend(tp, TT_DELACK);
7114 }
7115 
7116 static void
7117 rack_update_rsm(struct tcpcb *tp, struct tcp_rack *rack,
7118     struct rack_sendmap *rsm, uint64_t ts, uint16_t add_flag)
7119 {
7120 	int32_t idx;
7121 
7122 	rsm->r_rtr_cnt++;
7123 	rack_log_retran_reason(rack, rsm, __LINE__, 0, 2);
7124 	rsm->r_dupack = 0;
7125 	if (rsm->r_rtr_cnt > RACK_NUM_OF_RETRANS) {
7126 		rsm->r_rtr_cnt = RACK_NUM_OF_RETRANS;
7127 		rsm->r_flags |= RACK_OVERMAX;
7128 	}
7129 	if ((rsm->r_rtr_cnt > 1) && ((rsm->r_flags & RACK_TLP) == 0)) {
7130 		rack->r_ctl.rc_holes_rxt += (rsm->r_end - rsm->r_start);
7131 		rsm->r_rtr_bytes += (rsm->r_end - rsm->r_start);
7132 	}
7133 	idx = rsm->r_rtr_cnt - 1;
7134 	rsm->r_tim_lastsent[idx] = ts;
7135 	/*
7136 	 * Here we don't add in the len of send, since its already
7137 	 * in snduna <->snd_max.
7138 	 */
7139 	rsm->r_fas = ctf_flight_size(rack->rc_tp,
7140 				     rack->r_ctl.rc_sacked);
7141 	if (rsm->r_flags & RACK_ACKED) {
7142 		/* Problably MTU discovery messing with us */
7143 		rsm->r_flags &= ~RACK_ACKED;
7144 		rack->r_ctl.rc_sacked -= (rsm->r_end - rsm->r_start);
7145 	}
7146 	if (rsm->r_in_tmap) {
7147 		TAILQ_REMOVE(&rack->r_ctl.rc_tmap, rsm, r_tnext);
7148 		rsm->r_in_tmap = 0;
7149 	}
7150 	TAILQ_INSERT_TAIL(&rack->r_ctl.rc_tmap, rsm, r_tnext);
7151 	rsm->r_in_tmap = 1;
7152 	/* Take off the must retransmit flag, if its on */
7153 	if (rsm->r_flags & RACK_MUST_RXT) {
7154 		if (rack->r_must_retran)
7155 			rack->r_ctl.rc_out_at_rto -= (rsm->r_end - rsm->r_start);
7156 		if (SEQ_GEQ(rsm->r_end, rack->r_ctl.rc_snd_max_at_rto)) {
7157 			/*
7158 			 * We have retransmitted all we need. Clear
7159 			 * any must retransmit flags.
7160 			 */
7161 			rack->r_must_retran = 0;
7162 			rack->r_ctl.rc_out_at_rto = 0;
7163 		}
7164 		rsm->r_flags &= ~RACK_MUST_RXT;
7165 	}
7166 	if (rsm->r_flags & RACK_SACK_PASSED) {
7167 		/* We have retransmitted due to the SACK pass */
7168 		rsm->r_flags &= ~RACK_SACK_PASSED;
7169 		rsm->r_flags |= RACK_WAS_SACKPASS;
7170 	}
7171 }
7172 
7173 static uint32_t
7174 rack_update_entry(struct tcpcb *tp, struct tcp_rack *rack,
7175     struct rack_sendmap *rsm, uint64_t ts, int32_t *lenp, uint16_t add_flag)
7176 {
7177 	/*
7178 	 * We (re-)transmitted starting at rsm->r_start for some length
7179 	 * (possibly less than r_end.
7180 	 */
7181 	struct rack_sendmap *nrsm;
7182 #ifdef INVARIANTS
7183 	struct rack_sendmap *insret;
7184 #endif
7185 	uint32_t c_end;
7186 	int32_t len;
7187 
7188 	len = *lenp;
7189 	c_end = rsm->r_start + len;
7190 	if (SEQ_GEQ(c_end, rsm->r_end)) {
7191 		/*
7192 		 * We retransmitted the whole piece or more than the whole
7193 		 * slopping into the next rsm.
7194 		 */
7195 		rack_update_rsm(tp, rack, rsm, ts, add_flag);
7196 		if (c_end == rsm->r_end) {
7197 			*lenp = 0;
7198 			return (0);
7199 		} else {
7200 			int32_t act_len;
7201 
7202 			/* Hangs over the end return whats left */
7203 			act_len = rsm->r_end - rsm->r_start;
7204 			*lenp = (len - act_len);
7205 			return (rsm->r_end);
7206 		}
7207 		/* We don't get out of this block. */
7208 	}
7209 	/*
7210 	 * Here we retransmitted less than the whole thing which means we
7211 	 * have to split this into what was transmitted and what was not.
7212 	 */
7213 	nrsm = rack_alloc_full_limit(rack);
7214 	if (nrsm == NULL) {
7215 		/*
7216 		 * We can't get memory, so lets not proceed.
7217 		 */
7218 		*lenp = 0;
7219 		return (0);
7220 	}
7221 	/*
7222 	 * So here we are going to take the original rsm and make it what we
7223 	 * retransmitted. nrsm will be the tail portion we did not
7224 	 * retransmit. For example say the chunk was 1, 11 (10 bytes). And
7225 	 * we retransmitted 5 bytes i.e. 1, 5. The original piece shrinks to
7226 	 * 1, 6 and the new piece will be 6, 11.
7227 	 */
7228 	rack_clone_rsm(rack, nrsm, rsm, c_end);
7229 	nrsm->r_dupack = 0;
7230 	rack_log_retran_reason(rack, nrsm, __LINE__, 0, 2);
7231 #ifndef INVARIANTS
7232 	(void)RB_INSERT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, nrsm);
7233 #else
7234 	insret = RB_INSERT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, nrsm);
7235 	if (insret != NULL) {
7236 		panic("Insert in rb tree of %p fails ret:%p rack:%p rsm:%p",
7237 		      nrsm, insret, rack, rsm);
7238 	}
7239 #endif
7240 	if (rsm->r_in_tmap) {
7241 		TAILQ_INSERT_AFTER(&rack->r_ctl.rc_tmap, rsm, nrsm, r_tnext);
7242 		nrsm->r_in_tmap = 1;
7243 	}
7244 	rsm->r_flags &= (~RACK_HAS_FIN);
7245 	rack_update_rsm(tp, rack, rsm, ts, add_flag);
7246 	/* Log a split of rsm into rsm and nrsm */
7247 	rack_log_map_chg(tp, rack, NULL, rsm, nrsm, MAP_SPLIT, 0, __LINE__);
7248 	*lenp = 0;
7249 	return (0);
7250 }
7251 
7252 static void
7253 rack_log_output(struct tcpcb *tp, struct tcpopt *to, int32_t len,
7254 		uint32_t seq_out, uint16_t th_flags, int32_t err, uint64_t cts,
7255 		struct rack_sendmap *hintrsm, uint16_t add_flag, struct mbuf *s_mb, uint32_t s_moff, int hw_tls)
7256 {
7257 	struct tcp_rack *rack;
7258 	struct rack_sendmap *rsm, *nrsm, fe;
7259 #ifdef INVARIANTS
7260 	struct rack_sendmap *insret;
7261 #endif
7262 	register uint32_t snd_max, snd_una;
7263 
7264 	/*
7265 	 * Add to the RACK log of packets in flight or retransmitted. If
7266 	 * there is a TS option we will use the TS echoed, if not we will
7267 	 * grab a TS.
7268 	 *
7269 	 * Retransmissions will increment the count and move the ts to its
7270 	 * proper place. Note that if options do not include TS's then we
7271 	 * won't be able to effectively use the ACK for an RTT on a retran.
7272 	 *
7273 	 * Notes about r_start and r_end. Lets consider a send starting at
7274 	 * sequence 1 for 10 bytes. In such an example the r_start would be
7275 	 * 1 (starting sequence) but the r_end would be r_start+len i.e. 11.
7276 	 * This means that r_end is actually the first sequence for the next
7277 	 * slot (11).
7278 	 *
7279 	 */
7280 	/*
7281 	 * If err is set what do we do XXXrrs? should we not add the thing?
7282 	 * -- i.e. return if err != 0 or should we pretend we sent it? --
7283 	 * i.e. proceed with add ** do this for now.
7284 	 */
7285 	INP_WLOCK_ASSERT(tp->t_inpcb);
7286 	if (err)
7287 		/*
7288 		 * We don't log errors -- we could but snd_max does not
7289 		 * advance in this case either.
7290 		 */
7291 		return;
7292 
7293 	if (th_flags & TH_RST) {
7294 		/*
7295 		 * We don't log resets and we return immediately from
7296 		 * sending
7297 		 */
7298 		return;
7299 	}
7300 	rack = (struct tcp_rack *)tp->t_fb_ptr;
7301 	snd_una = tp->snd_una;
7302 	snd_max = tp->snd_max;
7303 	if (th_flags & (TH_SYN | TH_FIN)) {
7304 		/*
7305 		 * The call to rack_log_output is made before bumping
7306 		 * snd_max. This means we can record one extra byte on a SYN
7307 		 * or FIN if seq_out is adding more on and a FIN is present
7308 		 * (and we are not resending).
7309 		 */
7310 		if ((th_flags & TH_SYN) && (seq_out == tp->iss))
7311 			len++;
7312 		if (th_flags & TH_FIN)
7313 			len++;
7314 		if (SEQ_LT(snd_max, tp->snd_nxt)) {
7315 			/*
7316 			 * The add/update as not been done for the FIN/SYN
7317 			 * yet.
7318 			 */
7319 			snd_max = tp->snd_nxt;
7320 		}
7321 	}
7322 	if (SEQ_LEQ((seq_out + len), snd_una)) {
7323 		/* Are sending an old segment to induce an ack (keep-alive)? */
7324 		return;
7325 	}
7326 	if (SEQ_LT(seq_out, snd_una)) {
7327 		/* huh? should we panic? */
7328 		uint32_t end;
7329 
7330 		end = seq_out + len;
7331 		seq_out = snd_una;
7332 		if (SEQ_GEQ(end, seq_out))
7333 			len = end - seq_out;
7334 		else
7335 			len = 0;
7336 	}
7337 	if (len == 0) {
7338 		/* We don't log zero window probes */
7339 		return;
7340 	}
7341 	if (IN_FASTRECOVERY(tp->t_flags)) {
7342 		rack->r_ctl.rc_prr_out += len;
7343 	}
7344 	/* First question is it a retransmission or new? */
7345 	if (seq_out == snd_max) {
7346 		/* Its new */
7347 again:
7348 		rsm = rack_alloc(rack);
7349 		if (rsm == NULL) {
7350 			/*
7351 			 * Hmm out of memory and the tcb got destroyed while
7352 			 * we tried to wait.
7353 			 */
7354 			return;
7355 		}
7356 		if (th_flags & TH_FIN) {
7357 			rsm->r_flags = RACK_HAS_FIN|add_flag;
7358 		} else {
7359 			rsm->r_flags = add_flag;
7360 		}
7361 		if (hw_tls)
7362 			rsm->r_hw_tls = 1;
7363 		rsm->r_tim_lastsent[0] = cts;
7364 		rsm->r_rtr_cnt = 1;
7365 		rsm->r_rtr_bytes = 0;
7366 		if (th_flags & TH_SYN) {
7367 			/* The data space is one beyond snd_una */
7368 			rsm->r_flags |= RACK_HAS_SYN;
7369 		}
7370 		rsm->r_start = seq_out;
7371 		rsm->r_end = rsm->r_start + len;
7372 		rsm->r_dupack = 0;
7373 		/*
7374 		 * save off the mbuf location that
7375 		 * sndmbuf_noadv returned (which is
7376 		 * where we started copying from)..
7377 		 */
7378 		rsm->m = s_mb;
7379 		rsm->soff = s_moff;
7380 		/*
7381 		 * Here we do add in the len of send, since its not yet
7382 		 * reflected in in snduna <->snd_max
7383 		 */
7384 		rsm->r_fas = (ctf_flight_size(rack->rc_tp,
7385 					      rack->r_ctl.rc_sacked) +
7386 			      (rsm->r_end - rsm->r_start));
7387 		/* rsm->m will be NULL if RACK_HAS_SYN or RACK_HAS_FIN is set */
7388 		if (rsm->m) {
7389 			if (rsm->m->m_len <= rsm->soff) {
7390 				/*
7391 				 * XXXrrs Question, will this happen?
7392 				 *
7393 				 * If sbsndptr is set at the correct place
7394 				 * then s_moff should always be somewhere
7395 				 * within rsm->m. But if the sbsndptr was
7396 				 * off then that won't be true. If it occurs
7397 				 * we need to walkout to the correct location.
7398 				 */
7399 				struct mbuf *lm;
7400 
7401 				lm = rsm->m;
7402 				while (lm->m_len <= rsm->soff) {
7403 					rsm->soff -= lm->m_len;
7404 					lm = lm->m_next;
7405 					KASSERT(lm != NULL, ("%s rack:%p lm goes null orig_off:%u origmb:%p rsm->soff:%u",
7406 							     __func__, rack, s_moff, s_mb, rsm->soff));
7407 				}
7408 				rsm->m = lm;
7409 			}
7410 			rsm->orig_m_len = rsm->m->m_len;
7411 		} else
7412 			rsm->orig_m_len = 0;
7413 		rack_log_retran_reason(rack, rsm, __LINE__, 0, 2);
7414 		/* Log a new rsm */
7415 		rack_log_map_chg(tp, rack, NULL, rsm, NULL, MAP_NEW, 0, __LINE__);
7416 #ifndef INVARIANTS
7417 		(void)RB_INSERT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm);
7418 #else
7419 		insret = RB_INSERT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm);
7420 		if (insret != NULL) {
7421 			panic("Insert in rb tree of %p fails ret:%p rack:%p rsm:%p",
7422 			      nrsm, insret, rack, rsm);
7423 		}
7424 #endif
7425 		TAILQ_INSERT_TAIL(&rack->r_ctl.rc_tmap, rsm, r_tnext);
7426 		rsm->r_in_tmap = 1;
7427 		/*
7428 		 * Special case detection, is there just a single
7429 		 * packet outstanding when we are not in recovery?
7430 		 *
7431 		 * If this is true mark it so.
7432 		 */
7433 		if ((IN_FASTRECOVERY(tp->t_flags) == 0) &&
7434 		    (ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked) == ctf_fixed_maxseg(tp))) {
7435 			struct rack_sendmap *prsm;
7436 
7437 			prsm = RB_PREV(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm);
7438 			if (prsm)
7439 				prsm->r_one_out_nr = 1;
7440 		}
7441 		return;
7442 	}
7443 	/*
7444 	 * If we reach here its a retransmission and we need to find it.
7445 	 */
7446 	memset(&fe, 0, sizeof(fe));
7447 more:
7448 	if (hintrsm && (hintrsm->r_start == seq_out)) {
7449 		rsm = hintrsm;
7450 		hintrsm = NULL;
7451 	} else {
7452 		/* No hints sorry */
7453 		rsm = NULL;
7454 	}
7455 	if ((rsm) && (rsm->r_start == seq_out)) {
7456 		seq_out = rack_update_entry(tp, rack, rsm, cts, &len, add_flag);
7457 		if (len == 0) {
7458 			return;
7459 		} else {
7460 			goto more;
7461 		}
7462 	}
7463 	/* Ok it was not the last pointer go through it the hard way. */
7464 refind:
7465 	fe.r_start = seq_out;
7466 	rsm = RB_FIND(rack_rb_tree_head, &rack->r_ctl.rc_mtree, &fe);
7467 	if (rsm) {
7468 		if (rsm->r_start == seq_out) {
7469 			seq_out = rack_update_entry(tp, rack, rsm, cts, &len, add_flag);
7470 			if (len == 0) {
7471 				return;
7472 			} else {
7473 				goto refind;
7474 			}
7475 		}
7476 		if (SEQ_GEQ(seq_out, rsm->r_start) && SEQ_LT(seq_out, rsm->r_end)) {
7477 			/* Transmitted within this piece */
7478 			/*
7479 			 * Ok we must split off the front and then let the
7480 			 * update do the rest
7481 			 */
7482 			nrsm = rack_alloc_full_limit(rack);
7483 			if (nrsm == NULL) {
7484 				rack_update_rsm(tp, rack, rsm, cts, add_flag);
7485 				return;
7486 			}
7487 			/*
7488 			 * copy rsm to nrsm and then trim the front of rsm
7489 			 * to not include this part.
7490 			 */
7491 			rack_clone_rsm(rack, nrsm, rsm, seq_out);
7492 			rack_log_map_chg(tp, rack, NULL, rsm, nrsm, MAP_SPLIT, 0, __LINE__);
7493 #ifndef INVARIANTS
7494 			(void)RB_INSERT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, nrsm);
7495 #else
7496 			insret = RB_INSERT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, nrsm);
7497 			if (insret != NULL) {
7498 				panic("Insert in rb tree of %p fails ret:%p rack:%p rsm:%p",
7499 				      nrsm, insret, rack, rsm);
7500 			}
7501 #endif
7502 			if (rsm->r_in_tmap) {
7503 				TAILQ_INSERT_AFTER(&rack->r_ctl.rc_tmap, rsm, nrsm, r_tnext);
7504 				nrsm->r_in_tmap = 1;
7505 			}
7506 			rsm->r_flags &= (~RACK_HAS_FIN);
7507 			seq_out = rack_update_entry(tp, rack, nrsm, cts, &len, add_flag);
7508 			if (len == 0) {
7509 				return;
7510 			} else if (len > 0)
7511 				goto refind;
7512 		}
7513 	}
7514 	/*
7515 	 * Hmm not found in map did they retransmit both old and on into the
7516 	 * new?
7517 	 */
7518 	if (seq_out == tp->snd_max) {
7519 		goto again;
7520 	} else if (SEQ_LT(seq_out, tp->snd_max)) {
7521 #ifdef INVARIANTS
7522 		printf("seq_out:%u len:%d snd_una:%u snd_max:%u -- but rsm not found?\n",
7523 		       seq_out, len, tp->snd_una, tp->snd_max);
7524 		printf("Starting Dump of all rack entries\n");
7525 		RB_FOREACH(rsm, rack_rb_tree_head, &rack->r_ctl.rc_mtree) {
7526 			printf("rsm:%p start:%u end:%u\n",
7527 			       rsm, rsm->r_start, rsm->r_end);
7528 		}
7529 		printf("Dump complete\n");
7530 		panic("seq_out not found rack:%p tp:%p",
7531 		      rack, tp);
7532 #endif
7533 	} else {
7534 #ifdef INVARIANTS
7535 		/*
7536 		 * Hmm beyond sndmax? (only if we are using the new rtt-pack
7537 		 * flag)
7538 		 */
7539 		panic("seq_out:%u(%d) is beyond snd_max:%u tp:%p",
7540 		      seq_out, len, tp->snd_max, tp);
7541 #endif
7542 	}
7543 }
7544 
7545 /*
7546  * Record one of the RTT updates from an ack into
7547  * our sample structure.
7548  */
7549 
7550 static void
7551 tcp_rack_xmit_timer(struct tcp_rack *rack, int32_t rtt, uint32_t len, uint32_t us_rtt,
7552 		    int confidence, struct rack_sendmap *rsm, uint16_t rtrcnt)
7553 {
7554 	if ((rack->r_ctl.rack_rs.rs_flags & RACK_RTT_EMPTY) ||
7555 	    (rack->r_ctl.rack_rs.rs_rtt_lowest > rtt)) {
7556 		rack->r_ctl.rack_rs.rs_rtt_lowest = rtt;
7557 	}
7558 	if ((rack->r_ctl.rack_rs.rs_flags & RACK_RTT_EMPTY) ||
7559 	    (rack->r_ctl.rack_rs.rs_rtt_highest < rtt)) {
7560 		rack->r_ctl.rack_rs.rs_rtt_highest = rtt;
7561 	}
7562 	if (rack->rc_tp->t_flags & TF_GPUTINPROG) {
7563 	    if (us_rtt < rack->r_ctl.rc_gp_lowrtt)
7564 		rack->r_ctl.rc_gp_lowrtt = us_rtt;
7565 	    if (rack->rc_tp->snd_wnd > rack->r_ctl.rc_gp_high_rwnd)
7566 		    rack->r_ctl.rc_gp_high_rwnd = rack->rc_tp->snd_wnd;
7567 	}
7568 	if ((confidence == 1) &&
7569 	    ((rsm == NULL) ||
7570 	     (rsm->r_just_ret) ||
7571 	     (rsm->r_one_out_nr &&
7572 	      len < (ctf_fixed_maxseg(rack->rc_tp) * 2)))) {
7573 		/*
7574 		 * If the rsm had a just return
7575 		 * hit it then we can't trust the
7576 		 * rtt measurement for buffer deterimination
7577 		 * Note that a confidence of 2, indicates
7578 		 * SACK'd which overrides the r_just_ret or
7579 		 * the r_one_out_nr. If it was a CUM-ACK and
7580 		 * we had only two outstanding, but get an
7581 		 * ack for only 1. Then that also lowers our
7582 		 * confidence.
7583 		 */
7584 		confidence = 0;
7585 	}
7586 	if ((rack->r_ctl.rack_rs.rs_flags & RACK_RTT_EMPTY) ||
7587 	    (rack->r_ctl.rack_rs.rs_us_rtt > us_rtt)) {
7588 		if (rack->r_ctl.rack_rs.confidence == 0) {
7589 			/*
7590 			 * We take anything with no current confidence
7591 			 * saved.
7592 			 */
7593 			rack->r_ctl.rack_rs.rs_us_rtt = us_rtt;
7594 			rack->r_ctl.rack_rs.confidence = confidence;
7595 			rack->r_ctl.rack_rs.rs_us_rtrcnt = rtrcnt;
7596 		} else if (confidence || rack->r_ctl.rack_rs.confidence) {
7597 			/*
7598 			 * Once we have a confident number,
7599 			 * we can update it with a smaller
7600 			 * value since this confident number
7601 			 * may include the DSACK time until
7602 			 * the next segment (the second one) arrived.
7603 			 */
7604 			rack->r_ctl.rack_rs.rs_us_rtt = us_rtt;
7605 			rack->r_ctl.rack_rs.confidence = confidence;
7606 			rack->r_ctl.rack_rs.rs_us_rtrcnt = rtrcnt;
7607 		}
7608 	}
7609 	rack_log_rtt_upd(rack->rc_tp, rack, us_rtt, len, rsm, confidence);
7610 	rack->r_ctl.rack_rs.rs_flags = RACK_RTT_VALID;
7611 	rack->r_ctl.rack_rs.rs_rtt_tot += rtt;
7612 	rack->r_ctl.rack_rs.rs_rtt_cnt++;
7613 }
7614 
7615 /*
7616  * Collect new round-trip time estimate
7617  * and update averages and current timeout.
7618  */
7619 static void
7620 tcp_rack_xmit_timer_commit(struct tcp_rack *rack, struct tcpcb *tp)
7621 {
7622 	int32_t delta;
7623 	int32_t rtt;
7624 
7625 	if (rack->r_ctl.rack_rs.rs_flags & RACK_RTT_EMPTY)
7626 		/* No valid sample */
7627 		return;
7628 	if (rack->r_ctl.rc_rate_sample_method == USE_RTT_LOW) {
7629 		/* We are to use the lowest RTT seen in a single ack */
7630 		rtt = rack->r_ctl.rack_rs.rs_rtt_lowest;
7631 	} else if (rack->r_ctl.rc_rate_sample_method == USE_RTT_HIGH) {
7632 		/* We are to use the highest RTT seen in a single ack */
7633 		rtt = rack->r_ctl.rack_rs.rs_rtt_highest;
7634 	} else if (rack->r_ctl.rc_rate_sample_method == USE_RTT_AVG) {
7635 		/* We are to use the average RTT seen in a single ack */
7636 		rtt = (int32_t)(rack->r_ctl.rack_rs.rs_rtt_tot /
7637 				(uint64_t)rack->r_ctl.rack_rs.rs_rtt_cnt);
7638 	} else {
7639 #ifdef INVARIANTS
7640 		panic("Unknown rtt variant %d", rack->r_ctl.rc_rate_sample_method);
7641 #endif
7642 		return;
7643 	}
7644 	if (rtt == 0)
7645 		rtt = 1;
7646 	if (rack->rc_gp_rtt_set == 0) {
7647 		/*
7648 		 * With no RTT we have to accept
7649 		 * even one we are not confident of.
7650 		 */
7651 		rack->r_ctl.rc_gp_srtt = rack->r_ctl.rack_rs.rs_us_rtt;
7652 		rack->rc_gp_rtt_set = 1;
7653 	} else if (rack->r_ctl.rack_rs.confidence) {
7654 		/* update the running gp srtt */
7655 		rack->r_ctl.rc_gp_srtt -= (rack->r_ctl.rc_gp_srtt/8);
7656 		rack->r_ctl.rc_gp_srtt += rack->r_ctl.rack_rs.rs_us_rtt / 8;
7657 	}
7658 	if (rack->r_ctl.rack_rs.confidence) {
7659 		/*
7660 		 * record the low and high for highly buffered path computation,
7661 		 * we only do this if we are confident (not a retransmission).
7662 		 */
7663 		if (rack->r_ctl.rc_highest_us_rtt < rack->r_ctl.rack_rs.rs_us_rtt) {
7664 			rack->r_ctl.rc_highest_us_rtt = rack->r_ctl.rack_rs.rs_us_rtt;
7665 		}
7666 		if (rack->rc_highly_buffered == 0) {
7667 			/*
7668 			 * Currently once we declare a path has
7669 			 * highly buffered there is no going
7670 			 * back, which may be a problem...
7671 			 */
7672 			if ((rack->r_ctl.rc_highest_us_rtt / rack->r_ctl.rc_lowest_us_rtt) > rack_hbp_thresh) {
7673 				rack_log_rtt_shrinks(rack, rack->r_ctl.rack_rs.rs_us_rtt,
7674 						     rack->r_ctl.rc_highest_us_rtt,
7675 						     rack->r_ctl.rc_lowest_us_rtt,
7676 						     RACK_RTTS_SEEHBP);
7677 				rack->rc_highly_buffered = 1;
7678 			}
7679 		}
7680 	}
7681 	if ((rack->r_ctl.rack_rs.confidence) ||
7682 	    (rack->r_ctl.rack_rs.rs_us_rtrcnt == 1)) {
7683 		/*
7684 		 * If we are highly confident of it <or> it was
7685 		 * never retransmitted we accept it as the last us_rtt.
7686 		 */
7687 		rack->r_ctl.rc_last_us_rtt = rack->r_ctl.rack_rs.rs_us_rtt;
7688 		/* The lowest rtt can be set if its was not retransmited */
7689 		if (rack->r_ctl.rc_lowest_us_rtt > rack->r_ctl.rack_rs.rs_us_rtt) {
7690 			rack->r_ctl.rc_lowest_us_rtt = rack->r_ctl.rack_rs.rs_us_rtt;
7691 			if (rack->r_ctl.rc_lowest_us_rtt == 0)
7692 				rack->r_ctl.rc_lowest_us_rtt = 1;
7693 		}
7694 	}
7695 	rack = (struct tcp_rack *)tp->t_fb_ptr;
7696 	if (tp->t_srtt != 0) {
7697 		/*
7698 		 * We keep a simple srtt in microseconds, like our rtt
7699 		 * measurement. We don't need to do any tricks with shifting
7700 		 * etc. Instead we just add in 1/8th of the new measurement
7701 		 * and subtract out 1/8 of the old srtt. We do the same with
7702 		 * the variance after finding the absolute value of the
7703 		 * difference between this sample and the current srtt.
7704 		 */
7705 		delta = tp->t_srtt - rtt;
7706 		/* Take off 1/8th of the current sRTT */
7707 		tp->t_srtt -= (tp->t_srtt >> 3);
7708 		/* Add in 1/8th of the new RTT just measured */
7709 		tp->t_srtt += (rtt >> 3);
7710 		if (tp->t_srtt <= 0)
7711 			tp->t_srtt = 1;
7712 		/* Now lets make the absolute value of the variance */
7713 		if (delta < 0)
7714 			delta = -delta;
7715 		/* Subtract out 1/8th */
7716 		tp->t_rttvar -= (tp->t_rttvar >> 3);
7717 		/* Add in 1/8th of the new variance we just saw */
7718 		tp->t_rttvar += (delta >> 3);
7719 		if (tp->t_rttvar <= 0)
7720 			tp->t_rttvar = 1;
7721 		if (tp->t_rttbest > tp->t_srtt + tp->t_rttvar)
7722 			tp->t_rttbest = tp->t_srtt + tp->t_rttvar;
7723 	} else {
7724 		/*
7725 		 * No rtt measurement yet - use the unsmoothed rtt. Set the
7726 		 * variance to half the rtt (so our first retransmit happens
7727 		 * at 3*rtt).
7728 		 */
7729 		tp->t_srtt = rtt;
7730 		tp->t_rttvar = rtt >> 1;
7731 		tp->t_rttbest = tp->t_srtt + tp->t_rttvar;
7732 	}
7733 	rack->rc_srtt_measure_made = 1;
7734 	KMOD_TCPSTAT_INC(tcps_rttupdated);
7735 	tp->t_rttupdated++;
7736 #ifdef STATS
7737 	if (rack_stats_gets_ms_rtt == 0) {
7738 		/* Send in the microsecond rtt used for rxt timeout purposes */
7739 		stats_voi_update_abs_u32(tp->t_stats, VOI_TCP_RTT, imax(0, rtt));
7740 	} else if (rack_stats_gets_ms_rtt == 1) {
7741 		/* Send in the millisecond rtt used for rxt timeout purposes */
7742 		int32_t ms_rtt;
7743 
7744 		/* Round up */
7745 		ms_rtt = (rtt + HPTS_USEC_IN_MSEC - 1) / HPTS_USEC_IN_MSEC;
7746 		stats_voi_update_abs_u32(tp->t_stats, VOI_TCP_RTT, imax(0, ms_rtt));
7747 	} else if (rack_stats_gets_ms_rtt == 2) {
7748 		/* Send in the millisecond rtt has close to the path RTT as we can get  */
7749 		int32_t ms_rtt;
7750 
7751 		/* Round up */
7752 		ms_rtt = (rack->r_ctl.rack_rs.rs_us_rtt + HPTS_USEC_IN_MSEC - 1) / HPTS_USEC_IN_MSEC;
7753 		stats_voi_update_abs_u32(tp->t_stats, VOI_TCP_RTT, imax(0, ms_rtt));
7754 	}  else {
7755 		/* Send in the microsecond rtt has close to the path RTT as we can get  */
7756 		stats_voi_update_abs_u32(tp->t_stats, VOI_TCP_RTT, imax(0, rack->r_ctl.rack_rs.rs_us_rtt));
7757 	}
7758 
7759 #endif
7760 	/*
7761 	 * the retransmit should happen at rtt + 4 * rttvar. Because of the
7762 	 * way we do the smoothing, srtt and rttvar will each average +1/2
7763 	 * tick of bias.  When we compute the retransmit timer, we want 1/2
7764 	 * tick of rounding and 1 extra tick because of +-1/2 tick
7765 	 * uncertainty in the firing of the timer.  The bias will give us
7766 	 * exactly the 1.5 tick we need.  But, because the bias is
7767 	 * statistical, we have to test that we don't drop below the minimum
7768 	 * feasible timer (which is 2 ticks).
7769 	 */
7770 	tp->t_rxtshift = 0;
7771 	RACK_TCPT_RANGESET(tp->t_rxtcur, RACK_REXMTVAL(tp),
7772 		      max(rack_rto_min, rtt + 2), rack_rto_max, rack->r_ctl.timer_slop);
7773 	rack_log_rtt_sample(rack, rtt);
7774 	tp->t_softerror = 0;
7775 }
7776 
7777 
7778 static void
7779 rack_apply_updated_usrtt(struct tcp_rack *rack, uint32_t us_rtt, uint32_t us_cts)
7780 {
7781 	/*
7782 	 * Apply to filter the inbound us-rtt at us_cts.
7783 	 */
7784 	uint32_t old_rtt;
7785 
7786 	old_rtt = get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt);
7787 	apply_filter_min_small(&rack->r_ctl.rc_gp_min_rtt,
7788 			       us_rtt, us_cts);
7789 	if (old_rtt > us_rtt) {
7790 		/* We just hit a new lower rtt time */
7791 		rack_log_rtt_shrinks(rack,  us_cts,  old_rtt,
7792 				     __LINE__, RACK_RTTS_NEWRTT);
7793 		/*
7794 		 * Only count it if its lower than what we saw within our
7795 		 * calculated range.
7796 		 */
7797 		if ((old_rtt - us_rtt) > rack_min_rtt_movement) {
7798 			if (rack_probertt_lower_within &&
7799 			    rack->rc_gp_dyn_mul &&
7800 			    (rack->use_fixed_rate == 0) &&
7801 			    (rack->rc_always_pace)) {
7802 				/*
7803 				 * We are seeing a new lower rtt very close
7804 				 * to the time that we would have entered probe-rtt.
7805 				 * This is probably due to the fact that a peer flow
7806 				 * has entered probe-rtt. Lets go in now too.
7807 				 */
7808 				uint32_t val;
7809 
7810 				val = rack_probertt_lower_within * rack_time_between_probertt;
7811 				val /= 100;
7812 				if ((rack->in_probe_rtt == 0)  &&
7813 				    ((us_cts - rack->r_ctl.rc_lower_rtt_us_cts) >= (rack_time_between_probertt - val)))	{
7814 					rack_enter_probertt(rack, us_cts);
7815 				}
7816 			}
7817 			rack->r_ctl.rc_lower_rtt_us_cts = us_cts;
7818 		}
7819 	}
7820 }
7821 
7822 static int
7823 rack_update_rtt(struct tcpcb *tp, struct tcp_rack *rack,
7824     struct rack_sendmap *rsm, struct tcpopt *to, uint32_t cts, int32_t ack_type, tcp_seq th_ack)
7825 {
7826 	uint32_t us_rtt;
7827 	int32_t i, all;
7828 	uint32_t t, len_acked;
7829 
7830 	if ((rsm->r_flags & RACK_ACKED) ||
7831 	    (rsm->r_flags & RACK_WAS_ACKED))
7832 		/* Already done */
7833 		return (0);
7834 	if (rsm->r_no_rtt_allowed) {
7835 		/* Not allowed */
7836 		return (0);
7837 	}
7838 	if (ack_type == CUM_ACKED) {
7839 		if (SEQ_GT(th_ack, rsm->r_end)) {
7840 			len_acked = rsm->r_end - rsm->r_start;
7841 			all = 1;
7842 		} else {
7843 			len_acked = th_ack - rsm->r_start;
7844 			all = 0;
7845 		}
7846 	} else {
7847 		len_acked = rsm->r_end - rsm->r_start;
7848 		all = 0;
7849 	}
7850 	if (rsm->r_rtr_cnt == 1) {
7851 
7852 		t = cts - (uint32_t)rsm->r_tim_lastsent[(rsm->r_rtr_cnt - 1)];
7853 		if ((int)t <= 0)
7854 			t = 1;
7855 		if (!tp->t_rttlow || tp->t_rttlow > t)
7856 			tp->t_rttlow = t;
7857 		if (!rack->r_ctl.rc_rack_min_rtt ||
7858 		    SEQ_LT(t, rack->r_ctl.rc_rack_min_rtt)) {
7859 			rack->r_ctl.rc_rack_min_rtt = t;
7860 			if (rack->r_ctl.rc_rack_min_rtt == 0) {
7861 				rack->r_ctl.rc_rack_min_rtt = 1;
7862 			}
7863 		}
7864 		if (TSTMP_GT(tcp_tv_to_usectick(&rack->r_ctl.act_rcv_time), rsm->r_tim_lastsent[(rsm->r_rtr_cnt-1)]))
7865 			us_rtt = tcp_tv_to_usectick(&rack->r_ctl.act_rcv_time) - (uint32_t)rsm->r_tim_lastsent[(rsm->r_rtr_cnt-1)];
7866 		else
7867 			us_rtt = tcp_get_usecs(NULL) - (uint32_t)rsm->r_tim_lastsent[(rsm->r_rtr_cnt-1)];
7868 		if (us_rtt == 0)
7869 			us_rtt = 1;
7870 		if (CC_ALGO(tp)->rttsample != NULL) {
7871 			/* Kick the RTT to the CC */
7872 			CC_ALGO(tp)->rttsample(tp->ccv, us_rtt, 1, rsm->r_fas);
7873 		}
7874 		rack_apply_updated_usrtt(rack, us_rtt, tcp_tv_to_usectick(&rack->r_ctl.act_rcv_time));
7875 		if (ack_type == SACKED) {
7876 			rack_log_rtt_sample_calc(rack, t, (uint32_t)rsm->r_tim_lastsent[(rsm->r_rtr_cnt - 1)], cts, 1);
7877 			tcp_rack_xmit_timer(rack, t + 1, len_acked, us_rtt, 2 , rsm, rsm->r_rtr_cnt);
7878 		} else {
7879 			/*
7880 			 * We need to setup what our confidence
7881 			 * is in this ack.
7882 			 *
7883 			 * If the rsm was app limited and it is
7884 			 * less than a mss in length (the end
7885 			 * of the send) then we have a gap. If we
7886 			 * were app limited but say we were sending
7887 			 * multiple MSS's then we are more confident
7888 			 * int it.
7889 			 *
7890 			 * When we are not app-limited then we see if
7891 			 * the rsm is being included in the current
7892 			 * measurement, we tell this by the app_limited_needs_set
7893 			 * flag.
7894 			 *
7895 			 * Note that being cwnd blocked is not applimited
7896 			 * as well as the pacing delay between packets which
7897 			 * are sending only 1 or 2 MSS's also will show up
7898 			 * in the RTT. We probably need to examine this algorithm
7899 			 * a bit more and enhance it to account for the delay
7900 			 * between rsm's. We could do that by saving off the
7901 			 * pacing delay of each rsm (in an rsm) and then
7902 			 * factoring that in somehow though for now I am
7903 			 * not sure how :)
7904 			 */
7905 			int calc_conf = 0;
7906 
7907 			if (rsm->r_flags & RACK_APP_LIMITED) {
7908 				if (all && (len_acked <= ctf_fixed_maxseg(tp)))
7909 					calc_conf = 0;
7910 				else
7911 					calc_conf = 1;
7912 			} else if (rack->app_limited_needs_set == 0) {
7913 				calc_conf = 1;
7914 			} else {
7915 				calc_conf = 0;
7916 			}
7917 			rack_log_rtt_sample_calc(rack, t, (uint32_t)rsm->r_tim_lastsent[(rsm->r_rtr_cnt - 1)], cts, 2);
7918 			tcp_rack_xmit_timer(rack, t + 1, len_acked, us_rtt,
7919 					    calc_conf, rsm, rsm->r_rtr_cnt);
7920 		}
7921 		if ((rsm->r_flags & RACK_TLP) &&
7922 		    (!IN_FASTRECOVERY(tp->t_flags))) {
7923 			/* Segment was a TLP and our retrans matched */
7924 			if (rack->r_ctl.rc_tlp_cwnd_reduce) {
7925 				rack_cong_signal(tp, CC_NDUPACK, tp->snd_una, __LINE__);
7926 			}
7927 		}
7928 		if (SEQ_LT(rack->r_ctl.rc_rack_tmit_time, (uint32_t)rsm->r_tim_lastsent[(rsm->r_rtr_cnt - 1)])) {
7929 			/* New more recent rack_tmit_time */
7930 			rack->r_ctl.rc_rack_tmit_time = (uint32_t)rsm->r_tim_lastsent[(rsm->r_rtr_cnt - 1)];
7931 			rack->rc_rack_rtt = t;
7932 		}
7933 		return (1);
7934 	}
7935 	/*
7936 	 * We clear the soft/rxtshift since we got an ack.
7937 	 * There is no assurance we will call the commit() function
7938 	 * so we need to clear these to avoid incorrect handling.
7939 	 */
7940 	tp->t_rxtshift = 0;
7941 	RACK_TCPT_RANGESET(tp->t_rxtcur, RACK_REXMTVAL(tp),
7942 		      rack_rto_min, rack_rto_max, rack->r_ctl.timer_slop);
7943 	tp->t_softerror = 0;
7944 	if (to && (to->to_flags & TOF_TS) &&
7945 	    (ack_type == CUM_ACKED) &&
7946 	    (to->to_tsecr) &&
7947 	    ((rsm->r_flags & RACK_OVERMAX) == 0)) {
7948 		/*
7949 		 * Now which timestamp does it match? In this block the ACK
7950 		 * must be coming from a previous transmission.
7951 		 */
7952 		for (i = 0; i < rsm->r_rtr_cnt; i++) {
7953 			if (rack_ts_to_msec(rsm->r_tim_lastsent[i]) == to->to_tsecr) {
7954 				t = cts - (uint32_t)rsm->r_tim_lastsent[i];
7955 				if ((int)t <= 0)
7956 					t = 1;
7957 				if (CC_ALGO(tp)->rttsample != NULL) {
7958 					/*
7959 					 * Kick the RTT to the CC, here
7960 					 * we lie a bit in that we know the
7961 					 * retransmission is correct even though
7962 					 * we retransmitted. This is because
7963 					 * we match the timestamps.
7964 					 */
7965 					if (TSTMP_GT(tcp_tv_to_usectick(&rack->r_ctl.act_rcv_time), rsm->r_tim_lastsent[i]))
7966 						us_rtt = tcp_tv_to_usectick(&rack->r_ctl.act_rcv_time) - (uint32_t)rsm->r_tim_lastsent[i];
7967 					else
7968 						us_rtt = tcp_get_usecs(NULL) - (uint32_t)rsm->r_tim_lastsent[i];
7969 					CC_ALGO(tp)->rttsample(tp->ccv, us_rtt, 1, rsm->r_fas);
7970 				}
7971 				if ((i + 1) < rsm->r_rtr_cnt) {
7972 					/*
7973 					 * The peer ack'd from our previous
7974 					 * transmission. We have a spurious
7975 					 * retransmission and thus we dont
7976 					 * want to update our rack_rtt.
7977 					 *
7978 					 * Hmm should there be a CC revert here?
7979 					 *
7980 					 */
7981 					return (0);
7982 				}
7983 				if (!tp->t_rttlow || tp->t_rttlow > t)
7984 					tp->t_rttlow = t;
7985 				if (!rack->r_ctl.rc_rack_min_rtt || SEQ_LT(t, rack->r_ctl.rc_rack_min_rtt)) {
7986 					rack->r_ctl.rc_rack_min_rtt = t;
7987 					if (rack->r_ctl.rc_rack_min_rtt == 0) {
7988 						rack->r_ctl.rc_rack_min_rtt = 1;
7989 					}
7990 				}
7991 				if (SEQ_LT(rack->r_ctl.rc_rack_tmit_time,
7992 					   (uint32_t)rsm->r_tim_lastsent[(rsm->r_rtr_cnt - 1)])) {
7993 					/* New more recent rack_tmit_time */
7994 					rack->r_ctl.rc_rack_tmit_time = (uint32_t)rsm->r_tim_lastsent[(rsm->r_rtr_cnt - 1)];
7995 					rack->rc_rack_rtt = t;
7996 				}
7997 				rack_log_rtt_sample_calc(rack, t, (uint32_t)rsm->r_tim_lastsent[i], cts, 3);
7998 				tcp_rack_xmit_timer(rack, t + 1, len_acked, t, 0, rsm,
7999 						    rsm->r_rtr_cnt);
8000 				return (1);
8001 			}
8002 		}
8003 		goto ts_not_found;
8004 	} else {
8005 		/*
8006 		 * Ok its a SACK block that we retransmitted. or a windows
8007 		 * machine without timestamps. We can tell nothing from the
8008 		 * time-stamp since its not there or the time the peer last
8009 		 * recieved a segment that moved forward its cum-ack point.
8010 		 */
8011 ts_not_found:
8012 		i = rsm->r_rtr_cnt - 1;
8013 		t = cts - (uint32_t)rsm->r_tim_lastsent[i];
8014 		if ((int)t <= 0)
8015 			t = 1;
8016 		if (rack->r_ctl.rc_rack_min_rtt && SEQ_LT(t, rack->r_ctl.rc_rack_min_rtt)) {
8017 			/*
8018 			 * We retransmitted and the ack came back in less
8019 			 * than the smallest rtt we have observed. We most
8020 			 * likely did an improper retransmit as outlined in
8021 			 * 6.2 Step 2 point 2 in the rack-draft so we
8022 			 * don't want to update our rack_rtt. We in
8023 			 * theory (in future) might want to think about reverting our
8024 			 * cwnd state but we won't for now.
8025 			 */
8026 			return (0);
8027 		} else if (rack->r_ctl.rc_rack_min_rtt) {
8028 			/*
8029 			 * We retransmitted it and the retransmit did the
8030 			 * job.
8031 			 */
8032 			if (!rack->r_ctl.rc_rack_min_rtt ||
8033 			    SEQ_LT(t, rack->r_ctl.rc_rack_min_rtt)) {
8034 				rack->r_ctl.rc_rack_min_rtt = t;
8035 				if (rack->r_ctl.rc_rack_min_rtt == 0) {
8036 					rack->r_ctl.rc_rack_min_rtt = 1;
8037 				}
8038 			}
8039 			if (SEQ_LT(rack->r_ctl.rc_rack_tmit_time, (uint32_t)rsm->r_tim_lastsent[i])) {
8040 				/* New more recent rack_tmit_time */
8041 				rack->r_ctl.rc_rack_tmit_time = (uint32_t)rsm->r_tim_lastsent[i];
8042 				rack->rc_rack_rtt = t;
8043 			}
8044 			return (1);
8045 		}
8046 	}
8047 	return (0);
8048 }
8049 
8050 /*
8051  * Mark the SACK_PASSED flag on all entries prior to rsm send wise.
8052  */
8053 static void
8054 rack_log_sack_passed(struct tcpcb *tp,
8055     struct tcp_rack *rack, struct rack_sendmap *rsm)
8056 {
8057 	struct rack_sendmap *nrsm;
8058 
8059 	nrsm = rsm;
8060 	TAILQ_FOREACH_REVERSE_FROM(nrsm, &rack->r_ctl.rc_tmap,
8061 	    rack_head, r_tnext) {
8062 		if (nrsm == rsm) {
8063 			/* Skip orginal segment he is acked */
8064 			continue;
8065 		}
8066 		if (nrsm->r_flags & RACK_ACKED) {
8067 			/*
8068 			 * Skip ack'd segments, though we
8069 			 * should not see these, since tmap
8070 			 * should not have ack'd segments.
8071 			 */
8072 			continue;
8073 		}
8074 		if (nrsm->r_flags & RACK_RWND_COLLAPSED) {
8075 			/*
8076 			 * If the peer dropped the rwnd on
8077 			 * these then we don't worry about them.
8078 			 */
8079 			continue;
8080 		}
8081 		if (nrsm->r_flags & RACK_SACK_PASSED) {
8082 			/*
8083 			 * We found one that is already marked
8084 			 * passed, we have been here before and
8085 			 * so all others below this are marked.
8086 			 */
8087 			break;
8088 		}
8089 		nrsm->r_flags |= RACK_SACK_PASSED;
8090 		nrsm->r_flags &= ~RACK_WAS_SACKPASS;
8091 	}
8092 }
8093 
8094 static void
8095 rack_need_set_test(struct tcpcb *tp,
8096 		   struct tcp_rack *rack,
8097 		   struct rack_sendmap *rsm,
8098 		   tcp_seq th_ack,
8099 		   int line,
8100 		   int use_which)
8101 {
8102 
8103 	if ((tp->t_flags & TF_GPUTINPROG) &&
8104 	    SEQ_GEQ(rsm->r_end, tp->gput_seq)) {
8105 		/*
8106 		 * We were app limited, and this ack
8107 		 * butts up or goes beyond the point where we want
8108 		 * to start our next measurement. We need
8109 		 * to record the new gput_ts as here and
8110 		 * possibly update the start sequence.
8111 		 */
8112 		uint32_t seq, ts;
8113 
8114 		if (rsm->r_rtr_cnt > 1) {
8115 			/*
8116 			 * This is a retransmit, can we
8117 			 * really make any assessment at this
8118 			 * point?  We are not really sure of
8119 			 * the timestamp, is it this or the
8120 			 * previous transmission?
8121 			 *
8122 			 * Lets wait for something better that
8123 			 * is not retransmitted.
8124 			 */
8125 			return;
8126 		}
8127 		seq = tp->gput_seq;
8128 		ts = tp->gput_ts;
8129 		rack->app_limited_needs_set = 0;
8130 		tp->gput_ts = tcp_tv_to_usectick(&rack->r_ctl.act_rcv_time);
8131 		/* Do we start at a new end? */
8132 		if ((use_which == RACK_USE_BEG) &&
8133 		    SEQ_GEQ(rsm->r_start, tp->gput_seq)) {
8134 			/*
8135 			 * When we get an ACK that just eats
8136 			 * up some of the rsm, we set RACK_USE_BEG
8137 			 * since whats at r_start (i.e. th_ack)
8138 			 * is left unacked and thats where the
8139 			 * measurement not starts.
8140 			 */
8141 			tp->gput_seq = rsm->r_start;
8142 			rack->r_ctl.rc_gp_output_ts = rsm->r_tim_lastsent[(rsm->r_rtr_cnt-1)];
8143 		}
8144 		if ((use_which == RACK_USE_END) &&
8145 		    SEQ_GEQ(rsm->r_end, tp->gput_seq)) {
8146 			    /*
8147 			     * We use the end when the cumack
8148 			     * is moving forward and completely
8149 			     * deleting the rsm passed so basically
8150 			     * r_end holds th_ack.
8151 			     *
8152 			     * For SACK's we also want to use the end
8153 			     * since this piece just got sacked and
8154 			     * we want to target anything after that
8155 			     * in our measurement.
8156 			     */
8157 			    tp->gput_seq = rsm->r_end;
8158 			    rack->r_ctl.rc_gp_output_ts = rsm->r_tim_lastsent[(rsm->r_rtr_cnt-1)];
8159 		}
8160 		if (use_which == RACK_USE_END_OR_THACK) {
8161 			/*
8162 			 * special case for ack moving forward,
8163 			 * not a sack, we need to move all the
8164 			 * way up to where this ack cum-ack moves
8165 			 * to.
8166 			 */
8167 			if (SEQ_GT(th_ack, rsm->r_end))
8168 				tp->gput_seq = th_ack;
8169 			else
8170 				tp->gput_seq = rsm->r_end;
8171 			rack->r_ctl.rc_gp_output_ts = rsm->r_tim_lastsent[(rsm->r_rtr_cnt-1)];
8172 		}
8173 		if (SEQ_GT(tp->gput_seq, tp->gput_ack)) {
8174 			/*
8175 			 * We moved beyond this guy's range, re-calculate
8176 			 * the new end point.
8177 			 */
8178 			if (rack->rc_gp_filled == 0) {
8179 				tp->gput_ack = tp->gput_seq + max(rc_init_window(rack), (MIN_GP_WIN * ctf_fixed_maxseg(tp)));
8180 			} else {
8181 				tp->gput_ack = tp->gput_seq + rack_get_measure_window(tp, rack);
8182 			}
8183 		}
8184 		/*
8185 		 * We are moving the goal post, we may be able to clear the
8186 		 * measure_saw_probe_rtt flag.
8187 		 */
8188 		if ((rack->in_probe_rtt == 0) &&
8189 		    (rack->measure_saw_probe_rtt) &&
8190 		    (SEQ_GEQ(tp->gput_seq, rack->r_ctl.rc_probertt_sndmax_atexit)))
8191 			rack->measure_saw_probe_rtt = 0;
8192 		rack_log_pacing_delay_calc(rack, ts, tp->gput_ts,
8193 					   seq, tp->gput_seq, 0, 5, line, NULL, 0);
8194 		if (rack->rc_gp_filled &&
8195 		    ((tp->gput_ack - tp->gput_seq) <
8196 		     max(rc_init_window(rack), (MIN_GP_WIN *
8197 						ctf_fixed_maxseg(tp))))) {
8198 			uint32_t ideal_amount;
8199 
8200 			ideal_amount = rack_get_measure_window(tp, rack);
8201 			if (ideal_amount > sbavail(&tp->t_inpcb->inp_socket->so_snd)) {
8202 				/*
8203 				 * There is no sense of continuing this measurement
8204 				 * because its too small to gain us anything we
8205 				 * trust. Skip it and that way we can start a new
8206 				 * measurement quicker.
8207 				 */
8208 				tp->t_flags &= ~TF_GPUTINPROG;
8209 				rack_log_pacing_delay_calc(rack, tp->gput_ack, tp->gput_seq,
8210 							   0, 0, 0, 6, __LINE__, NULL, 0);
8211 			} else {
8212 				/*
8213 				 * Reset the window further out.
8214 				 */
8215 				tp->gput_ack = tp->gput_seq + ideal_amount;
8216 			}
8217 		}
8218 	}
8219 }
8220 
8221 static inline int
8222 is_rsm_inside_declared_tlp_block(struct tcp_rack *rack, struct rack_sendmap *rsm)
8223 {
8224 	if (SEQ_LT(rsm->r_end, rack->r_ctl.last_tlp_acked_start)) {
8225 		/* Behind our TLP definition or right at */
8226 		return (0);
8227 	}
8228 	if (SEQ_GT(rsm->r_start, rack->r_ctl.last_tlp_acked_end)) {
8229 		/* The start is beyond or right at our end of TLP definition */
8230 		return (0);
8231 	}
8232 	/* It has to be a sub-part of the original TLP recorded */
8233 	return (1);
8234 }
8235 
8236 
8237 static uint32_t
8238 rack_proc_sack_blk(struct tcpcb *tp, struct tcp_rack *rack, struct sackblk *sack,
8239 		   struct tcpopt *to, struct rack_sendmap **prsm, uint32_t cts, int *moved_two)
8240 {
8241 	uint32_t start, end, changed = 0;
8242 	struct rack_sendmap stack_map;
8243 	struct rack_sendmap *rsm, *nrsm, fe, *prev, *next;
8244 #ifdef INVARIANTS
8245 	struct rack_sendmap *insret;
8246 #endif
8247 	int32_t used_ref = 1;
8248 	int moved = 0;
8249 
8250 	start = sack->start;
8251 	end = sack->end;
8252 	rsm = *prsm;
8253 	memset(&fe, 0, sizeof(fe));
8254 do_rest_ofb:
8255 	if ((rsm == NULL) ||
8256 	    (SEQ_LT(end, rsm->r_start)) ||
8257 	    (SEQ_GEQ(start, rsm->r_end)) ||
8258 	    (SEQ_LT(start, rsm->r_start))) {
8259 		/*
8260 		 * We are not in the right spot,
8261 		 * find the correct spot in the tree.
8262 		 */
8263 		used_ref = 0;
8264 		fe.r_start = start;
8265 		rsm = RB_FIND(rack_rb_tree_head, &rack->r_ctl.rc_mtree, &fe);
8266 		moved++;
8267 	}
8268 	if (rsm == NULL) {
8269 		/* TSNH */
8270 		goto out;
8271 	}
8272 	/* Ok we have an ACK for some piece of this rsm */
8273 	if (rsm->r_start != start) {
8274 		if ((rsm->r_flags & RACK_ACKED) == 0) {
8275 			/*
8276 			 * Before any splitting or hookery is
8277 			 * done is it a TLP of interest i.e. rxt?
8278 			 */
8279 			if ((rsm->r_flags & RACK_TLP) &&
8280 			    (rsm->r_rtr_cnt > 1)) {
8281 				/*
8282 				 * We are splitting a rxt TLP, check
8283 				 * if we need to save off the start/end
8284 				 */
8285 				if (rack->rc_last_tlp_acked_set &&
8286 				    (is_rsm_inside_declared_tlp_block(rack, rsm))) {
8287 					/*
8288 					 * We already turned this on since we are inside
8289 					 * the previous one was a partially sack now we
8290 					 * are getting another one (maybe all of it).
8291 					 *
8292 					 */
8293 					rack_log_dsack_event(rack, 10, __LINE__, rsm->r_start, rsm->r_end);
8294 					/*
8295 					 * Lets make sure we have all of it though.
8296 					 */
8297 					if (SEQ_LT(rsm->r_start, rack->r_ctl.last_tlp_acked_start)) {
8298 						rack->r_ctl.last_tlp_acked_start = rsm->r_start;
8299 						rack_log_dsack_event(rack, 11, __LINE__, rack->r_ctl.last_tlp_acked_start,
8300 								     rack->r_ctl.last_tlp_acked_end);
8301 					}
8302 					if (SEQ_GT(rsm->r_end, rack->r_ctl.last_tlp_acked_end)) {
8303 						rack->r_ctl.last_tlp_acked_end = rsm->r_end;
8304 						rack_log_dsack_event(rack, 11, __LINE__, rack->r_ctl.last_tlp_acked_start,
8305 								     rack->r_ctl.last_tlp_acked_end);
8306 					}
8307 				} else {
8308 					rack->r_ctl.last_tlp_acked_start = rsm->r_start;
8309 					rack->r_ctl.last_tlp_acked_end = rsm->r_end;
8310 					rack->rc_last_tlp_past_cumack = 0;
8311 					rack->rc_last_tlp_acked_set = 1;
8312 					rack_log_dsack_event(rack, 8, __LINE__, rsm->r_start, rsm->r_end);
8313 				}
8314 			}
8315 			/**
8316 			 * Need to split this in two pieces the before and after,
8317 			 * the before remains in the map, the after must be
8318 			 * added. In other words we have:
8319 			 * rsm        |--------------|
8320 			 * sackblk        |------->
8321 			 * rsm will become
8322 			 *     rsm    |---|
8323 			 * and nrsm will be  the sacked piece
8324 			 *     nrsm       |----------|
8325 			 *
8326 			 * But before we start down that path lets
8327 			 * see if the sack spans over on top of
8328 			 * the next guy and it is already sacked.
8329 			 *
8330 			 */
8331 			next = RB_NEXT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm);
8332 			if (next && (next->r_flags & RACK_ACKED) &&
8333 			    SEQ_GEQ(end, next->r_start)) {
8334 				/**
8335 				 * So the next one is already acked, and
8336 				 * we can thus by hookery use our stack_map
8337 				 * to reflect the piece being sacked and
8338 				 * then adjust the two tree entries moving
8339 				 * the start and ends around. So we start like:
8340 				 *  rsm     |------------|             (not-acked)
8341 				 *  next                 |-----------| (acked)
8342 				 *  sackblk        |-------->
8343 				 *  We want to end like so:
8344 				 *  rsm     |------|                   (not-acked)
8345 				 *  next           |-----------------| (acked)
8346 				 *  nrsm           |-----|
8347 				 * Where nrsm is a temporary stack piece we
8348 				 * use to update all the gizmos.
8349 				 */
8350 				/* Copy up our fudge block */
8351 				nrsm = &stack_map;
8352 				memcpy(nrsm, rsm, sizeof(struct rack_sendmap));
8353 				/* Now adjust our tree blocks */
8354 				rsm->r_end = start;
8355 				next->r_start = start;
8356 				/* Now we must adjust back where next->m is */
8357 				rack_setup_offset_for_rsm(rsm, next);
8358 
8359 				/* We don't need to adjust rsm, it did not change */
8360 				/* Clear out the dup ack count of the remainder */
8361 				rsm->r_dupack = 0;
8362 				rsm->r_just_ret = 0;
8363 				rack_log_retran_reason(rack, rsm, __LINE__, 0, 2);
8364 				/* Now lets make sure our fudge block is right */
8365 				nrsm->r_start = start;
8366 				/* Now lets update all the stats and such */
8367 				rack_update_rtt(tp, rack, nrsm, to, cts, SACKED, 0);
8368 				if (rack->app_limited_needs_set)
8369 					rack_need_set_test(tp, rack, nrsm, tp->snd_una, __LINE__, RACK_USE_END);
8370 				changed += (nrsm->r_end - nrsm->r_start);
8371 				rack->r_ctl.rc_sacked += (nrsm->r_end - nrsm->r_start);
8372 				if (nrsm->r_flags & RACK_SACK_PASSED) {
8373 					rack->r_ctl.rc_reorder_ts = cts;
8374 				}
8375 				/*
8376 				 * Now we want to go up from rsm (the
8377 				 * one left un-acked) to the next one
8378 				 * in the tmap. We do this so when
8379 				 * we walk backwards we include marking
8380 				 * sack-passed on rsm (The one passed in
8381 				 * is skipped since it is generally called
8382 				 * on something sacked before removing it
8383 				 * from the tmap).
8384 				 */
8385 				if (rsm->r_in_tmap) {
8386 					nrsm = TAILQ_NEXT(rsm, r_tnext);
8387 					/*
8388 					 * Now that we have the next
8389 					 * one walk backwards from there.
8390 					 */
8391 					if (nrsm && nrsm->r_in_tmap)
8392 						rack_log_sack_passed(tp, rack, nrsm);
8393 				}
8394 				/* Now are we done? */
8395 				if (SEQ_LT(end, next->r_end) ||
8396 				    (end == next->r_end)) {
8397 					/* Done with block */
8398 					goto out;
8399 				}
8400 				rack_log_map_chg(tp, rack, &stack_map, rsm, next, MAP_SACK_M1, end, __LINE__);
8401 				counter_u64_add(rack_sack_used_next_merge, 1);
8402 				/* Postion for the next block */
8403 				start = next->r_end;
8404 				rsm = RB_NEXT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, next);
8405 				if (rsm == NULL)
8406 					goto out;
8407 			} else {
8408 				/**
8409 				 * We can't use any hookery here, so we
8410 				 * need to split the map. We enter like
8411 				 * so:
8412 				 *  rsm      |--------|
8413 				 *  sackblk       |----->
8414 				 * We will add the new block nrsm and
8415 				 * that will be the new portion, and then
8416 				 * fall through after reseting rsm. So we
8417 				 * split and look like this:
8418 				 *  rsm      |----|
8419 				 *  sackblk       |----->
8420 				 *  nrsm          |---|
8421 				 * We then fall through reseting
8422 				 * rsm to nrsm, so the next block
8423 				 * picks it up.
8424 				 */
8425 				nrsm = rack_alloc_limit(rack, RACK_LIMIT_TYPE_SPLIT);
8426 				if (nrsm == NULL) {
8427 					/*
8428 					 * failed XXXrrs what can we do but loose the sack
8429 					 * info?
8430 					 */
8431 					goto out;
8432 				}
8433 				counter_u64_add(rack_sack_splits, 1);
8434 				rack_clone_rsm(rack, nrsm, rsm, start);
8435 				rsm->r_just_ret = 0;
8436 #ifndef INVARIANTS
8437 				(void)RB_INSERT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, nrsm);
8438 #else
8439 				insret = RB_INSERT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, nrsm);
8440 				if (insret != NULL) {
8441 					panic("Insert in rb tree of %p fails ret:%p rack:%p rsm:%p",
8442 					      nrsm, insret, rack, rsm);
8443 				}
8444 #endif
8445 				if (rsm->r_in_tmap) {
8446 					TAILQ_INSERT_AFTER(&rack->r_ctl.rc_tmap, rsm, nrsm, r_tnext);
8447 					nrsm->r_in_tmap = 1;
8448 				}
8449 				rack_log_map_chg(tp, rack, NULL, rsm, nrsm, MAP_SACK_M2, end, __LINE__);
8450 				rsm->r_flags &= (~RACK_HAS_FIN);
8451 				/* Position us to point to the new nrsm that starts the sack blk */
8452 				rsm = nrsm;
8453 			}
8454 		} else {
8455 			/* Already sacked this piece */
8456 			counter_u64_add(rack_sack_skipped_acked, 1);
8457 			moved++;
8458 			if (end == rsm->r_end) {
8459 				/* Done with block */
8460 				rsm = RB_NEXT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm);
8461 				goto out;
8462 			} else if (SEQ_LT(end, rsm->r_end)) {
8463 				/* A partial sack to a already sacked block */
8464 				moved++;
8465 				rsm = RB_NEXT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm);
8466 				goto out;
8467 			} else {
8468 				/*
8469 				 * The end goes beyond this guy
8470 				 * reposition the start to the
8471 				 * next block.
8472 				 */
8473 				start = rsm->r_end;
8474 				rsm = RB_NEXT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm);
8475 				if (rsm == NULL)
8476 					goto out;
8477 			}
8478 		}
8479 	}
8480 	if (SEQ_GEQ(end, rsm->r_end)) {
8481 		/**
8482 		 * The end of this block is either beyond this guy or right
8483 		 * at this guy. I.e.:
8484 		 *  rsm ---                 |-----|
8485 		 *  end                     |-----|
8486 		 *  <or>
8487 		 *  end                     |---------|
8488 		 */
8489 		if ((rsm->r_flags & RACK_ACKED) == 0) {
8490 			/*
8491 			 * Is it a TLP of interest?
8492 			 */
8493 			if ((rsm->r_flags & RACK_TLP) &&
8494 			    (rsm->r_rtr_cnt > 1)) {
8495 				/*
8496 				 * We are splitting a rxt TLP, check
8497 				 * if we need to save off the start/end
8498 				 */
8499 				if (rack->rc_last_tlp_acked_set &&
8500 				    (is_rsm_inside_declared_tlp_block(rack, rsm))) {
8501 					/*
8502 					 * We already turned this on since we are inside
8503 					 * the previous one was a partially sack now we
8504 					 * are getting another one (maybe all of it).
8505 					 */
8506 					rack_log_dsack_event(rack, 10, __LINE__, rsm->r_start, rsm->r_end);
8507 					/*
8508 					 * Lets make sure we have all of it though.
8509 					 */
8510 					if (SEQ_LT(rsm->r_start, rack->r_ctl.last_tlp_acked_start)) {
8511 						rack->r_ctl.last_tlp_acked_start = rsm->r_start;
8512 						rack_log_dsack_event(rack, 11, __LINE__, rack->r_ctl.last_tlp_acked_start,
8513 								     rack->r_ctl.last_tlp_acked_end);
8514 					}
8515 					if (SEQ_GT(rsm->r_end, rack->r_ctl.last_tlp_acked_end)) {
8516 						rack->r_ctl.last_tlp_acked_end = rsm->r_end;
8517 						rack_log_dsack_event(rack, 11, __LINE__, rack->r_ctl.last_tlp_acked_start,
8518 								     rack->r_ctl.last_tlp_acked_end);
8519 					}
8520 				} else {
8521 					rack->r_ctl.last_tlp_acked_start = rsm->r_start;
8522 					rack->r_ctl.last_tlp_acked_end = rsm->r_end;
8523 					rack->rc_last_tlp_past_cumack = 0;
8524 					rack->rc_last_tlp_acked_set = 1;
8525 					rack_log_dsack_event(rack, 8, __LINE__, rsm->r_start, rsm->r_end);
8526 				}
8527 			}
8528 			rack_update_rtt(tp, rack, rsm, to, cts, SACKED, 0);
8529 			changed += (rsm->r_end - rsm->r_start);
8530 			rack->r_ctl.rc_sacked += (rsm->r_end - rsm->r_start);
8531 			if (rsm->r_in_tmap) /* should be true */
8532 				rack_log_sack_passed(tp, rack, rsm);
8533 			/* Is Reordering occuring? */
8534 			if (rsm->r_flags & RACK_SACK_PASSED) {
8535 				rsm->r_flags &= ~RACK_SACK_PASSED;
8536 				rack->r_ctl.rc_reorder_ts = cts;
8537 			}
8538 			if (rack->app_limited_needs_set)
8539 				rack_need_set_test(tp, rack, rsm, tp->snd_una, __LINE__, RACK_USE_END);
8540 			rsm->r_ack_arrival = rack_to_usec_ts(&rack->r_ctl.act_rcv_time);
8541 			rsm->r_flags |= RACK_ACKED;
8542 			if (rsm->r_in_tmap) {
8543 				TAILQ_REMOVE(&rack->r_ctl.rc_tmap, rsm, r_tnext);
8544 				rsm->r_in_tmap = 0;
8545 			}
8546 			rack_log_map_chg(tp, rack, NULL, rsm, NULL, MAP_SACK_M3, end, __LINE__);
8547 		} else {
8548 			counter_u64_add(rack_sack_skipped_acked, 1);
8549 			moved++;
8550 		}
8551 		if (end == rsm->r_end) {
8552 			/* This block only - done, setup for next */
8553 			goto out;
8554 		}
8555 		/*
8556 		 * There is more not coverend by this rsm move on
8557 		 * to the next block in the RB tree.
8558 		 */
8559 		nrsm = RB_NEXT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm);
8560 		start = rsm->r_end;
8561 		rsm = nrsm;
8562 		if (rsm == NULL)
8563 			goto out;
8564 		goto do_rest_ofb;
8565 	}
8566 	/**
8567 	 * The end of this sack block is smaller than
8568 	 * our rsm i.e.:
8569 	 *  rsm ---                 |-----|
8570 	 *  end                     |--|
8571 	 */
8572 	if ((rsm->r_flags & RACK_ACKED) == 0) {
8573 		/*
8574 		 * Is it a TLP of interest?
8575 		 */
8576 		if ((rsm->r_flags & RACK_TLP) &&
8577 		    (rsm->r_rtr_cnt > 1)) {
8578 			/*
8579 			 * We are splitting a rxt TLP, check
8580 			 * if we need to save off the start/end
8581 			 */
8582 			if (rack->rc_last_tlp_acked_set &&
8583 			    (is_rsm_inside_declared_tlp_block(rack, rsm))) {
8584 				/*
8585 				 * We already turned this on since we are inside
8586 				 * the previous one was a partially sack now we
8587 				 * are getting another one (maybe all of it).
8588 				 */
8589 				rack_log_dsack_event(rack, 10, __LINE__, rsm->r_start, rsm->r_end);
8590 				/*
8591 				 * Lets make sure we have all of it though.
8592 				 */
8593 				if (SEQ_LT(rsm->r_start, rack->r_ctl.last_tlp_acked_start)) {
8594 					rack->r_ctl.last_tlp_acked_start = rsm->r_start;
8595 					rack_log_dsack_event(rack, 11, __LINE__, rack->r_ctl.last_tlp_acked_start,
8596 							     rack->r_ctl.last_tlp_acked_end);
8597 				}
8598 				if (SEQ_GT(rsm->r_end, rack->r_ctl.last_tlp_acked_end)) {
8599 					rack->r_ctl.last_tlp_acked_end = rsm->r_end;
8600 					rack_log_dsack_event(rack, 11, __LINE__, rack->r_ctl.last_tlp_acked_start,
8601 							     rack->r_ctl.last_tlp_acked_end);
8602 				}
8603 			} else {
8604 				rack->r_ctl.last_tlp_acked_start = rsm->r_start;
8605 				rack->r_ctl.last_tlp_acked_end = rsm->r_end;
8606 				rack->rc_last_tlp_past_cumack = 0;
8607 				rack->rc_last_tlp_acked_set = 1;
8608 				rack_log_dsack_event(rack, 8, __LINE__, rsm->r_start, rsm->r_end);
8609 			}
8610 		}
8611 		prev = RB_PREV(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm);
8612 		if (prev &&
8613 		    (prev->r_flags & RACK_ACKED)) {
8614 			/**
8615 			 * Goal, we want the right remainder of rsm to shrink
8616 			 * in place and span from (rsm->r_start = end) to rsm->r_end.
8617 			 * We want to expand prev to go all the way
8618 			 * to prev->r_end <- end.
8619 			 * so in the tree we have before:
8620 			 *   prev     |--------|         (acked)
8621 			 *   rsm               |-------| (non-acked)
8622 			 *   sackblk           |-|
8623 			 * We churn it so we end up with
8624 			 *   prev     |----------|       (acked)
8625 			 *   rsm                 |-----| (non-acked)
8626 			 *   nrsm              |-| (temporary)
8627 			 *
8628 			 * Note if either prev/rsm is a TLP we don't
8629 			 * do this.
8630 			 */
8631 			nrsm = &stack_map;
8632 			memcpy(nrsm, rsm, sizeof(struct rack_sendmap));
8633 			prev->r_end = end;
8634 			rsm->r_start = end;
8635 			/* Now adjust nrsm (stack copy) to be
8636 			 * the one that is the small
8637 			 * piece that was "sacked".
8638 			 */
8639 			nrsm->r_end = end;
8640 			rsm->r_dupack = 0;
8641 			rack_log_retran_reason(rack, rsm, __LINE__, 0, 2);
8642 			/*
8643 			 * Now that the rsm has had its start moved forward
8644 			 * lets go ahead and get its new place in the world.
8645 			 */
8646 			rack_setup_offset_for_rsm(prev, rsm);
8647 			/*
8648 			 * Now nrsm is our new little piece
8649 			 * that is acked (which was merged
8650 			 * to prev). Update the rtt and changed
8651 			 * based on that. Also check for reordering.
8652 			 */
8653 			rack_update_rtt(tp, rack, nrsm, to, cts, SACKED, 0);
8654 			if (rack->app_limited_needs_set)
8655 				rack_need_set_test(tp, rack, nrsm, tp->snd_una, __LINE__, RACK_USE_END);
8656 			changed += (nrsm->r_end - nrsm->r_start);
8657 			rack->r_ctl.rc_sacked += (nrsm->r_end - nrsm->r_start);
8658 			if (nrsm->r_flags & RACK_SACK_PASSED) {
8659 				rack->r_ctl.rc_reorder_ts = cts;
8660 			}
8661 			rack_log_map_chg(tp, rack, prev, &stack_map, rsm, MAP_SACK_M4, end, __LINE__);
8662 			rsm = prev;
8663 			counter_u64_add(rack_sack_used_prev_merge, 1);
8664 		} else {
8665 			/**
8666 			 * This is the case where our previous
8667 			 * block is not acked either, so we must
8668 			 * split the block in two.
8669 			 */
8670 			nrsm = rack_alloc_limit(rack, RACK_LIMIT_TYPE_SPLIT);
8671 			if (nrsm == NULL) {
8672 				/* failed rrs what can we do but loose the sack info? */
8673 				goto out;
8674 			}
8675 			if ((rsm->r_flags & RACK_TLP) &&
8676 			    (rsm->r_rtr_cnt > 1)) {
8677 				/*
8678 				 * We are splitting a rxt TLP, check
8679 				 * if we need to save off the start/end
8680 				 */
8681 				if (rack->rc_last_tlp_acked_set &&
8682 				    (is_rsm_inside_declared_tlp_block(rack, rsm))) {
8683 					    /*
8684 					     * We already turned this on since this block is inside
8685 					     * the previous one was a partially sack now we
8686 					     * are getting another one (maybe all of it).
8687 					     */
8688 					    rack_log_dsack_event(rack, 10, __LINE__, rsm->r_start, rsm->r_end);
8689 					    /*
8690 					     * Lets make sure we have all of it though.
8691 					     */
8692 					    if (SEQ_LT(rsm->r_start, rack->r_ctl.last_tlp_acked_start)) {
8693 						    rack->r_ctl.last_tlp_acked_start = rsm->r_start;
8694 						    rack_log_dsack_event(rack, 11, __LINE__, rack->r_ctl.last_tlp_acked_start,
8695 									 rack->r_ctl.last_tlp_acked_end);
8696 					    }
8697 					    if (SEQ_GT(rsm->r_end, rack->r_ctl.last_tlp_acked_end)) {
8698 						    rack->r_ctl.last_tlp_acked_end = rsm->r_end;
8699 						    rack_log_dsack_event(rack, 11, __LINE__, rack->r_ctl.last_tlp_acked_start,
8700 									 rack->r_ctl.last_tlp_acked_end);
8701 					    }
8702 				    } else {
8703 					    rack->r_ctl.last_tlp_acked_start = rsm->r_start;
8704 					    rack->r_ctl.last_tlp_acked_end = rsm->r_end;
8705 					    rack->rc_last_tlp_acked_set = 1;
8706 					    rack->rc_last_tlp_past_cumack = 0;
8707 					    rack_log_dsack_event(rack, 8, __LINE__, rsm->r_start, rsm->r_end);
8708 				    }
8709 			}
8710 			/**
8711 			 * In this case nrsm becomes
8712 			 * nrsm->r_start = end;
8713 			 * nrsm->r_end = rsm->r_end;
8714 			 * which is un-acked.
8715 			 * <and>
8716 			 * rsm->r_end = nrsm->r_start;
8717 			 * i.e. the remaining un-acked
8718 			 * piece is left on the left
8719 			 * hand side.
8720 			 *
8721 			 * So we start like this
8722 			 * rsm      |----------| (not acked)
8723 			 * sackblk  |---|
8724 			 * build it so we have
8725 			 * rsm      |---|         (acked)
8726 			 * nrsm         |------|  (not acked)
8727 			 */
8728 			counter_u64_add(rack_sack_splits, 1);
8729 			rack_clone_rsm(rack, nrsm, rsm, end);
8730 			rsm->r_flags &= (~RACK_HAS_FIN);
8731 			rsm->r_just_ret = 0;
8732 #ifndef INVARIANTS
8733 			(void)RB_INSERT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, nrsm);
8734 #else
8735 			insret = RB_INSERT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, nrsm);
8736 			if (insret != NULL) {
8737 				panic("Insert in rb tree of %p fails ret:%p rack:%p rsm:%p",
8738 				      nrsm, insret, rack, rsm);
8739 			}
8740 #endif
8741 			if (rsm->r_in_tmap) {
8742 				TAILQ_INSERT_AFTER(&rack->r_ctl.rc_tmap, rsm, nrsm, r_tnext);
8743 				nrsm->r_in_tmap = 1;
8744 			}
8745 			nrsm->r_dupack = 0;
8746 			rack_log_retran_reason(rack, nrsm, __LINE__, 0, 2);
8747 			rack_update_rtt(tp, rack, rsm, to, cts, SACKED, 0);
8748 			changed += (rsm->r_end - rsm->r_start);
8749 			rack->r_ctl.rc_sacked += (rsm->r_end - rsm->r_start);
8750 			if (rsm->r_in_tmap) /* should be true */
8751 				rack_log_sack_passed(tp, rack, rsm);
8752 			/* Is Reordering occuring? */
8753 			if (rsm->r_flags & RACK_SACK_PASSED) {
8754 				rsm->r_flags &= ~RACK_SACK_PASSED;
8755 				rack->r_ctl.rc_reorder_ts = cts;
8756 			}
8757 			if (rack->app_limited_needs_set)
8758 				rack_need_set_test(tp, rack, rsm, tp->snd_una, __LINE__, RACK_USE_END);
8759 			rsm->r_ack_arrival = rack_to_usec_ts(&rack->r_ctl.act_rcv_time);
8760 			rsm->r_flags |= RACK_ACKED;
8761 			rack_log_map_chg(tp, rack, NULL, rsm, nrsm, MAP_SACK_M5, end, __LINE__);
8762 			if (rsm->r_in_tmap) {
8763 				TAILQ_REMOVE(&rack->r_ctl.rc_tmap, rsm, r_tnext);
8764 				rsm->r_in_tmap = 0;
8765 			}
8766 		}
8767 	} else if (start != end){
8768 		/*
8769 		 * The block was already acked.
8770 		 */
8771 		counter_u64_add(rack_sack_skipped_acked, 1);
8772 		moved++;
8773 	}
8774 out:
8775 	if (rsm &&
8776 	    ((rsm->r_flags & RACK_TLP) == 0) &&
8777 	    (rsm->r_flags & RACK_ACKED)) {
8778 		/*
8779 		 * Now can we merge where we worked
8780 		 * with either the previous or
8781 		 * next block?
8782 		 */
8783 		next = RB_NEXT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm);
8784 		while (next) {
8785 			if (next->r_flags & RACK_TLP)
8786 				break;
8787 			if (next->r_flags & RACK_ACKED) {
8788 			/* yep this and next can be merged */
8789 				rsm = rack_merge_rsm(rack, rsm, next);
8790 				next = RB_NEXT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm);
8791 			} else
8792 				break;
8793 		}
8794 		/* Now what about the previous? */
8795 		prev = RB_PREV(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm);
8796 		while (prev) {
8797 			if (prev->r_flags & RACK_TLP)
8798 				break;
8799 			if (prev->r_flags & RACK_ACKED) {
8800 				/* yep the previous and this can be merged */
8801 				rsm = rack_merge_rsm(rack, prev, rsm);
8802 				prev = RB_PREV(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm);
8803 			} else
8804 				break;
8805 		}
8806 	}
8807 	if (used_ref == 0) {
8808 		counter_u64_add(rack_sack_proc_all, 1);
8809 	} else {
8810 		counter_u64_add(rack_sack_proc_short, 1);
8811 	}
8812 	/* Save off the next one for quick reference. */
8813 	if (rsm)
8814 		nrsm = RB_NEXT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm);
8815 	else
8816 		nrsm = NULL;
8817 	*prsm = rack->r_ctl.rc_sacklast = nrsm;
8818 	/* Pass back the moved. */
8819 	*moved_two = moved;
8820 	return (changed);
8821 }
8822 
8823 static void inline
8824 rack_peer_reneges(struct tcp_rack *rack, struct rack_sendmap *rsm, tcp_seq th_ack)
8825 {
8826 	struct rack_sendmap *tmap;
8827 
8828 	tmap = NULL;
8829 	while (rsm && (rsm->r_flags & RACK_ACKED)) {
8830 		/* Its no longer sacked, mark it so */
8831 		rack->r_ctl.rc_sacked -= (rsm->r_end - rsm->r_start);
8832 #ifdef INVARIANTS
8833 		if (rsm->r_in_tmap) {
8834 			panic("rack:%p rsm:%p flags:0x%x in tmap?",
8835 			      rack, rsm, rsm->r_flags);
8836 		}
8837 #endif
8838 		rsm->r_flags &= ~(RACK_ACKED|RACK_SACK_PASSED|RACK_WAS_SACKPASS);
8839 		/* Rebuild it into our tmap */
8840 		if (tmap == NULL) {
8841 			TAILQ_INSERT_HEAD(&rack->r_ctl.rc_tmap, rsm, r_tnext);
8842 			tmap = rsm;
8843 		} else {
8844 			TAILQ_INSERT_AFTER(&rack->r_ctl.rc_tmap, tmap, rsm, r_tnext);
8845 			tmap = rsm;
8846 		}
8847 		tmap->r_in_tmap = 1;
8848 		rsm = RB_NEXT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm);
8849 	}
8850 	/*
8851 	 * Now lets possibly clear the sack filter so we start
8852 	 * recognizing sacks that cover this area.
8853 	 */
8854 	sack_filter_clear(&rack->r_ctl.rack_sf, th_ack);
8855 
8856 }
8857 
8858 static void
8859 rack_do_decay(struct tcp_rack *rack)
8860 {
8861 	struct timeval res;
8862 
8863 #define	timersub(tvp, uvp, vvp)						\
8864 	do {								\
8865 		(vvp)->tv_sec = (tvp)->tv_sec - (uvp)->tv_sec;		\
8866 		(vvp)->tv_usec = (tvp)->tv_usec - (uvp)->tv_usec;	\
8867 		if ((vvp)->tv_usec < 0) {				\
8868 			(vvp)->tv_sec--;				\
8869 			(vvp)->tv_usec += 1000000;			\
8870 		}							\
8871 	} while (0)
8872 
8873 	timersub(&rack->r_ctl.act_rcv_time, &rack->r_ctl.rc_last_time_decay, &res);
8874 #undef timersub
8875 
8876 	rack->r_ctl.input_pkt++;
8877 	if ((rack->rc_in_persist) ||
8878 	    (res.tv_sec >= 1) ||
8879 	    (rack->rc_tp->snd_max == rack->rc_tp->snd_una)) {
8880 		/*
8881 		 * Check for decay of non-SAD,
8882 		 * we want all SAD detection metrics to
8883 		 * decay 1/4 per second (or more) passed.
8884 		 */
8885 #ifdef NETFLIX_EXP_DETECTION
8886 		uint32_t pkt_delta;
8887 
8888 		pkt_delta = rack->r_ctl.input_pkt - rack->r_ctl.saved_input_pkt;
8889 #endif
8890 		/* Update our saved tracking values */
8891 		rack->r_ctl.saved_input_pkt = rack->r_ctl.input_pkt;
8892 		rack->r_ctl.rc_last_time_decay = rack->r_ctl.act_rcv_time;
8893 		/* Now do we escape without decay? */
8894 #ifdef NETFLIX_EXP_DETECTION
8895 		if (rack->rc_in_persist ||
8896 		    (rack->rc_tp->snd_max == rack->rc_tp->snd_una) ||
8897 		    (pkt_delta < tcp_sad_low_pps)){
8898 			/*
8899 			 * We don't decay idle connections
8900 			 * or ones that have a low input pps.
8901 			 */
8902 			return;
8903 		}
8904 		/* Decay the counters */
8905 		rack->r_ctl.ack_count = ctf_decay_count(rack->r_ctl.ack_count,
8906 							tcp_sad_decay_val);
8907 		rack->r_ctl.sack_count = ctf_decay_count(rack->r_ctl.sack_count,
8908 							 tcp_sad_decay_val);
8909 		rack->r_ctl.sack_moved_extra = ctf_decay_count(rack->r_ctl.sack_moved_extra,
8910 							       tcp_sad_decay_val);
8911 		rack->r_ctl.sack_noextra_move = ctf_decay_count(rack->r_ctl.sack_noextra_move,
8912 								tcp_sad_decay_val);
8913 #endif
8914 	}
8915 }
8916 
8917 static void
8918 rack_process_to_cumack(struct tcpcb *tp, struct tcp_rack *rack, register uint32_t th_ack, uint32_t cts, struct tcpopt *to)
8919 {
8920 	struct rack_sendmap *rsm;
8921 #ifdef INVARIANTS
8922 	struct rack_sendmap *rm;
8923 #endif
8924 
8925 	/*
8926 	 * The ACK point is advancing to th_ack, we must drop off
8927 	 * the packets in the rack log and calculate any eligble
8928 	 * RTT's.
8929 	 */
8930 	rack->r_wanted_output = 1;
8931 
8932 	/* Tend any TLP that has been marked for 1/2 the seq space (its old)  */
8933 	if ((rack->rc_last_tlp_acked_set == 1)&&
8934 	    (rack->rc_last_tlp_past_cumack == 1) &&
8935 	    (SEQ_GT(rack->r_ctl.last_tlp_acked_start, th_ack))) {
8936 		/*
8937 		 * We have reached the point where our last rack
8938 		 * tlp retransmit sequence is ahead of the cum-ack.
8939 		 * This can only happen when the cum-ack moves all
8940 		 * the way around (its been a full 2^^31+1 bytes
8941 		 * or more since we sent a retransmitted TLP). Lets
8942 		 * turn off the valid flag since its not really valid.
8943 		 *
8944 		 * Note since sack's also turn on this event we have
8945 		 * a complication, we have to wait to age it out until
8946 		 * the cum-ack is by the TLP before checking which is
8947 		 * what the next else clause does.
8948 		 */
8949 		rack_log_dsack_event(rack, 9, __LINE__,
8950 				     rack->r_ctl.last_tlp_acked_start,
8951 				     rack->r_ctl.last_tlp_acked_end);
8952 		rack->rc_last_tlp_acked_set = 0;
8953 		rack->rc_last_tlp_past_cumack = 0;
8954 	} else if ((rack->rc_last_tlp_acked_set == 1) &&
8955 		   (rack->rc_last_tlp_past_cumack == 0) &&
8956 		   (SEQ_GEQ(th_ack, rack->r_ctl.last_tlp_acked_end))) {
8957 		/*
8958 		 * It is safe to start aging TLP's out.
8959 		 */
8960 		rack->rc_last_tlp_past_cumack = 1;
8961 	}
8962 	/* We do the same for the tlp send seq as well */
8963 	if ((rack->rc_last_sent_tlp_seq_valid == 1) &&
8964 	    (rack->rc_last_sent_tlp_past_cumack == 1) &&
8965 	    (SEQ_GT(rack->r_ctl.last_sent_tlp_seq,  th_ack))) {
8966 		rack_log_dsack_event(rack, 9, __LINE__,
8967 				     rack->r_ctl.last_sent_tlp_seq,
8968 				     (rack->r_ctl.last_sent_tlp_seq +
8969 				      rack->r_ctl.last_sent_tlp_len));
8970 		rack->rc_last_sent_tlp_seq_valid = 0;
8971 		rack->rc_last_sent_tlp_past_cumack = 0;
8972 	} else if ((rack->rc_last_sent_tlp_seq_valid == 1) &&
8973 		   (rack->rc_last_sent_tlp_past_cumack == 0) &&
8974 		   (SEQ_GEQ(th_ack, rack->r_ctl.last_sent_tlp_seq))) {
8975 		/*
8976 		 * It is safe to start aging TLP's send.
8977 		 */
8978 		rack->rc_last_sent_tlp_past_cumack = 1;
8979 	}
8980 more:
8981 	rsm = RB_MIN(rack_rb_tree_head, &rack->r_ctl.rc_mtree);
8982 	if (rsm == NULL) {
8983 		if ((th_ack - 1) == tp->iss) {
8984 			/*
8985 			 * For the SYN incoming case we will not
8986 			 * have called tcp_output for the sending of
8987 			 * the SYN, so there will be no map. All
8988 			 * other cases should probably be a panic.
8989 			 */
8990 			return;
8991 		}
8992 		if (tp->t_flags & TF_SENTFIN) {
8993 			/* if we sent a FIN we often will not have map */
8994 			return;
8995 		}
8996 #ifdef INVARIANTS
8997 		panic("No rack map tp:%p for state:%d ack:%u rack:%p snd_una:%u snd_max:%u snd_nxt:%u\n",
8998 		      tp,
8999 		      tp->t_state, th_ack, rack,
9000 		      tp->snd_una, tp->snd_max, tp->snd_nxt);
9001 #endif
9002 		return;
9003 	}
9004 	if (SEQ_LT(th_ack, rsm->r_start)) {
9005 		/* Huh map is missing this */
9006 #ifdef INVARIANTS
9007 		printf("Rack map starts at r_start:%u for th_ack:%u huh? ts:%d rs:%d\n",
9008 		       rsm->r_start,
9009 		       th_ack, tp->t_state, rack->r_state);
9010 #endif
9011 		return;
9012 	}
9013 	rack_update_rtt(tp, rack, rsm, to, cts, CUM_ACKED, th_ack);
9014 
9015 	/* Now was it a retransmitted TLP? */
9016 	if ((rsm->r_flags & RACK_TLP) &&
9017 	    (rsm->r_rtr_cnt > 1)) {
9018 		/*
9019 		 * Yes, this rsm was a TLP and retransmitted, remember that
9020 		 * since if a DSACK comes back on this we don't want
9021 		 * to think of it as a reordered segment. This may
9022 		 * get updated again with possibly even other TLPs
9023 		 * in flight, but thats ok. Only when we don't send
9024 		 * a retransmitted TLP for 1/2 the sequences space
9025 		 * will it get turned off (above).
9026 		 */
9027 		if (rack->rc_last_tlp_acked_set &&
9028 		    (is_rsm_inside_declared_tlp_block(rack, rsm))) {
9029 			/*
9030 			 * We already turned this on since the end matches,
9031 			 * the previous one was a partially ack now we
9032 			 * are getting another one (maybe all of it).
9033 			 */
9034 			rack_log_dsack_event(rack, 10, __LINE__, rsm->r_start, rsm->r_end);
9035 			/*
9036 			 * Lets make sure we have all of it though.
9037 			 */
9038 			if (SEQ_LT(rsm->r_start, rack->r_ctl.last_tlp_acked_start)) {
9039 				rack->r_ctl.last_tlp_acked_start = rsm->r_start;
9040 				rack_log_dsack_event(rack, 11, __LINE__, rack->r_ctl.last_tlp_acked_start,
9041 						     rack->r_ctl.last_tlp_acked_end);
9042 			}
9043 			if (SEQ_GT(rsm->r_end, rack->r_ctl.last_tlp_acked_end)) {
9044 				rack->r_ctl.last_tlp_acked_end = rsm->r_end;
9045 				rack_log_dsack_event(rack, 11, __LINE__, rack->r_ctl.last_tlp_acked_start,
9046 						     rack->r_ctl.last_tlp_acked_end);
9047 			}
9048 		} else {
9049 			rack->rc_last_tlp_past_cumack = 1;
9050 			rack->r_ctl.last_tlp_acked_start = rsm->r_start;
9051 			rack->r_ctl.last_tlp_acked_end = rsm->r_end;
9052 			rack->rc_last_tlp_acked_set = 1;
9053 			rack_log_dsack_event(rack, 8, __LINE__, rsm->r_start, rsm->r_end);
9054 		}
9055 	}
9056 	/* Now do we consume the whole thing? */
9057 	if (SEQ_GEQ(th_ack, rsm->r_end)) {
9058 		/* Its all consumed. */
9059 		uint32_t left;
9060 		uint8_t newly_acked;
9061 
9062 		rack_log_map_chg(tp, rack, NULL, rsm, NULL, MAP_FREE, rsm->r_end, __LINE__);
9063 		rack->r_ctl.rc_holes_rxt -= rsm->r_rtr_bytes;
9064 		rsm->r_rtr_bytes = 0;
9065 		/* Record the time of highest cumack sent */
9066 		rack->r_ctl.rc_gp_cumack_ts = rsm->r_tim_lastsent[(rsm->r_rtr_cnt-1)];
9067 #ifndef INVARIANTS
9068 		(void)RB_REMOVE(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm);
9069 #else
9070 		rm = RB_REMOVE(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm);
9071 		if (rm != rsm) {
9072 			panic("removing head in rack:%p rsm:%p rm:%p",
9073 			      rack, rsm, rm);
9074 		}
9075 #endif
9076 		if (rsm->r_in_tmap) {
9077 			TAILQ_REMOVE(&rack->r_ctl.rc_tmap, rsm, r_tnext);
9078 			rsm->r_in_tmap = 0;
9079 		}
9080 		newly_acked = 1;
9081 		if (rsm->r_flags & RACK_ACKED) {
9082 			/*
9083 			 * It was acked on the scoreboard -- remove
9084 			 * it from total
9085 			 */
9086 			rack->r_ctl.rc_sacked -= (rsm->r_end - rsm->r_start);
9087 			newly_acked = 0;
9088 		} else if (rsm->r_flags & RACK_SACK_PASSED) {
9089 			/*
9090 			 * There are segments ACKED on the
9091 			 * scoreboard further up. We are seeing
9092 			 * reordering.
9093 			 */
9094 			rsm->r_flags &= ~RACK_SACK_PASSED;
9095 			rsm->r_ack_arrival = rack_to_usec_ts(&rack->r_ctl.act_rcv_time);
9096 			rsm->r_flags |= RACK_ACKED;
9097 			rack->r_ctl.rc_reorder_ts = cts;
9098 			if (rack->r_ent_rec_ns) {
9099 				/*
9100 				 * We have sent no more, and we saw an sack
9101 				 * then ack arrive.
9102 				 */
9103 				rack->r_might_revert = 1;
9104 			}
9105 		}
9106 		if ((rsm->r_flags & RACK_TO_REXT) &&
9107 		    (tp->t_flags & TF_RCVD_TSTMP) &&
9108 		    (to->to_flags & TOF_TS) &&
9109 		    (to->to_tsecr != 0) &&
9110 		    (tp->t_flags & TF_PREVVALID)) {
9111 			/*
9112 			 * We can use the timestamp to see
9113 			 * if this retransmission was from the
9114 			 * first transmit. If so we made a mistake.
9115 			 */
9116 			tp->t_flags &= ~TF_PREVVALID;
9117 			if (to->to_tsecr == rack_ts_to_msec(rsm->r_tim_lastsent[0])) {
9118 				/* The first transmit is what this ack is for */
9119 				rack_cong_signal(tp, CC_RTO_ERR, th_ack, __LINE__);
9120 			}
9121 		}
9122 		left = th_ack - rsm->r_end;
9123 		if (rack->app_limited_needs_set && newly_acked)
9124 			rack_need_set_test(tp, rack, rsm, th_ack, __LINE__, RACK_USE_END_OR_THACK);
9125 		/* Free back to zone */
9126 		rack_free(rack, rsm);
9127 		if (left) {
9128 			goto more;
9129 		}
9130 		/* Check for reneging */
9131 		rsm = RB_MIN(rack_rb_tree_head, &rack->r_ctl.rc_mtree);
9132 		if (rsm && (rsm->r_flags & RACK_ACKED) && (th_ack == rsm->r_start)) {
9133 			/*
9134 			 * The peer has moved snd_una up to
9135 			 * the edge of this send, i.e. one
9136 			 * that it had previously acked. The only
9137 			 * way that can be true if the peer threw
9138 			 * away data (space issues) that it had
9139 			 * previously sacked (else it would have
9140 			 * given us snd_una up to (rsm->r_end).
9141 			 * We need to undo the acked markings here.
9142 			 *
9143 			 * Note we have to look to make sure th_ack is
9144 			 * our rsm->r_start in case we get an old ack
9145 			 * where th_ack is behind snd_una.
9146 			 */
9147 			rack_peer_reneges(rack, rsm, th_ack);
9148 		}
9149 		return;
9150 	}
9151 	if (rsm->r_flags & RACK_ACKED) {
9152 		/*
9153 		 * It was acked on the scoreboard -- remove it from
9154 		 * total for the part being cum-acked.
9155 		 */
9156 		rack->r_ctl.rc_sacked -= (th_ack - rsm->r_start);
9157 	}
9158 	/*
9159 	 * Clear the dup ack count for
9160 	 * the piece that remains.
9161 	 */
9162 	rsm->r_dupack = 0;
9163 	rack_log_retran_reason(rack, rsm, __LINE__, 0, 2);
9164 	if (rsm->r_rtr_bytes) {
9165 		/*
9166 		 * It was retransmitted adjust the
9167 		 * sack holes for what was acked.
9168 		 */
9169 		int ack_am;
9170 
9171 		ack_am = (th_ack - rsm->r_start);
9172 		if (ack_am >= rsm->r_rtr_bytes) {
9173 			rack->r_ctl.rc_holes_rxt -= ack_am;
9174 			rsm->r_rtr_bytes -= ack_am;
9175 		}
9176 	}
9177 	/*
9178 	 * Update where the piece starts and record
9179 	 * the time of send of highest cumack sent.
9180 	 */
9181 	rack->r_ctl.rc_gp_cumack_ts = rsm->r_tim_lastsent[(rsm->r_rtr_cnt-1)];
9182 	rack_log_map_chg(tp, rack, NULL, rsm, NULL, MAP_TRIM_HEAD, th_ack, __LINE__);
9183 	/* Now we need to move our offset forward too */
9184 	if (rsm->m && (rsm->orig_m_len != rsm->m->m_len)) {
9185 		/* Fix up the orig_m_len and possibly the mbuf offset */
9186 		rack_adjust_orig_mlen(rsm);
9187 	}
9188 	rsm->soff += (th_ack - rsm->r_start);
9189 	rsm->r_start = th_ack;
9190 	/* Now do we need to move the mbuf fwd too? */
9191 	if (rsm->m) {
9192 		while (rsm->soff >= rsm->m->m_len) {
9193 			rsm->soff -= rsm->m->m_len;
9194 			rsm->m = rsm->m->m_next;
9195 			KASSERT((rsm->m != NULL),
9196 				(" nrsm:%p hit at soff:%u null m",
9197 				 rsm, rsm->soff));
9198 		}
9199 		rsm->orig_m_len = rsm->m->m_len;
9200 	}
9201 	if (rack->app_limited_needs_set)
9202 		rack_need_set_test(tp, rack, rsm, tp->snd_una, __LINE__, RACK_USE_BEG);
9203 }
9204 
9205 static void
9206 rack_handle_might_revert(struct tcpcb *tp, struct tcp_rack *rack)
9207 {
9208 	struct rack_sendmap *rsm;
9209 	int sack_pass_fnd = 0;
9210 
9211 	if (rack->r_might_revert) {
9212 		/*
9213 		 * Ok we have reordering, have not sent anything, we
9214 		 * might want to revert the congestion state if nothing
9215 		 * further has SACK_PASSED on it. Lets check.
9216 		 *
9217 		 * We also get here when we have DSACKs come in for
9218 		 * all the data that we FR'd. Note that a rxt or tlp
9219 		 * timer clears this from happening.
9220 		 */
9221 
9222 		TAILQ_FOREACH(rsm, &rack->r_ctl.rc_tmap, r_tnext) {
9223 			if (rsm->r_flags & RACK_SACK_PASSED) {
9224 				sack_pass_fnd = 1;
9225 				break;
9226 			}
9227 		}
9228 		if (sack_pass_fnd == 0) {
9229 			/*
9230 			 * We went into recovery
9231 			 * incorrectly due to reordering!
9232 			 */
9233 			int orig_cwnd;
9234 
9235 			rack->r_ent_rec_ns = 0;
9236 			orig_cwnd = tp->snd_cwnd;
9237 			tp->snd_ssthresh = rack->r_ctl.rc_ssthresh_at_erec;
9238 			tp->snd_recover = tp->snd_una;
9239 			rack_log_to_prr(rack, 14, orig_cwnd, __LINE__);
9240 			EXIT_RECOVERY(tp->t_flags);
9241 		}
9242 		rack->r_might_revert = 0;
9243 	}
9244 }
9245 
9246 #ifdef NETFLIX_EXP_DETECTION
9247 static void
9248 rack_do_detection(struct tcpcb *tp, struct tcp_rack *rack,  uint32_t bytes_this_ack, uint32_t segsiz)
9249 {
9250 	if ((rack->do_detection || tcp_force_detection) &&
9251 	    tcp_sack_to_ack_thresh &&
9252 	    tcp_sack_to_move_thresh &&
9253 	    ((rack->r_ctl.rc_num_maps_alloced > tcp_map_minimum) || rack->sack_attack_disable)) {
9254 		/*
9255 		 * We have thresholds set to find
9256 		 * possible attackers and disable sack.
9257 		 * Check them.
9258 		 */
9259 		uint64_t ackratio, moveratio, movetotal;
9260 
9261 		/* Log detecting */
9262 		rack_log_sad(rack, 1);
9263 		ackratio = (uint64_t)(rack->r_ctl.sack_count);
9264 		ackratio *= (uint64_t)(1000);
9265 		if (rack->r_ctl.ack_count)
9266 			ackratio /= (uint64_t)(rack->r_ctl.ack_count);
9267 		else {
9268 			/* We really should not hit here */
9269 			ackratio = 1000;
9270 		}
9271 		if ((rack->sack_attack_disable == 0) &&
9272 		    (ackratio > rack_highest_sack_thresh_seen))
9273 			rack_highest_sack_thresh_seen = (uint32_t)ackratio;
9274 		movetotal = rack->r_ctl.sack_moved_extra;
9275 		movetotal += rack->r_ctl.sack_noextra_move;
9276 		moveratio = rack->r_ctl.sack_moved_extra;
9277 		moveratio *= (uint64_t)1000;
9278 		if (movetotal)
9279 			moveratio /= movetotal;
9280 		else {
9281 			/* No moves, thats pretty good */
9282 			moveratio = 0;
9283 		}
9284 		if ((rack->sack_attack_disable == 0) &&
9285 		    (moveratio > rack_highest_move_thresh_seen))
9286 			rack_highest_move_thresh_seen = (uint32_t)moveratio;
9287 		if (rack->sack_attack_disable == 0) {
9288 			if ((ackratio > tcp_sack_to_ack_thresh) &&
9289 			    (moveratio > tcp_sack_to_move_thresh)) {
9290 				/* Disable sack processing */
9291 				rack->sack_attack_disable = 1;
9292 				if (rack->r_rep_attack == 0) {
9293 					rack->r_rep_attack = 1;
9294 					counter_u64_add(rack_sack_attacks_detected, 1);
9295 				}
9296 				if (tcp_attack_on_turns_on_logging) {
9297 					/*
9298 					 * Turn on logging, used for debugging
9299 					 * false positives.
9300 					 */
9301 					rack->rc_tp->t_logstate = tcp_attack_on_turns_on_logging;
9302 				}
9303 				/* Clamp the cwnd at flight size */
9304 				rack->r_ctl.rc_saved_cwnd = rack->rc_tp->snd_cwnd;
9305 				rack->rc_tp->snd_cwnd = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
9306 				rack_log_sad(rack, 2);
9307 			}
9308 		} else {
9309 			/* We are sack-disabled check for false positives */
9310 			if ((ackratio <= tcp_restoral_thresh) ||
9311 			    (rack->r_ctl.rc_num_maps_alloced  < tcp_map_minimum)) {
9312 				rack->sack_attack_disable = 0;
9313 				rack_log_sad(rack, 3);
9314 				/* Restart counting */
9315 				rack->r_ctl.sack_count = 0;
9316 				rack->r_ctl.sack_moved_extra = 0;
9317 				rack->r_ctl.sack_noextra_move = 1;
9318 				rack->r_ctl.ack_count = max(1,
9319 				      (bytes_this_ack / segsiz));
9320 
9321 				if (rack->r_rep_reverse == 0) {
9322 					rack->r_rep_reverse = 1;
9323 					counter_u64_add(rack_sack_attacks_reversed, 1);
9324 				}
9325 				/* Restore the cwnd */
9326 				if (rack->r_ctl.rc_saved_cwnd > rack->rc_tp->snd_cwnd)
9327 					rack->rc_tp->snd_cwnd = rack->r_ctl.rc_saved_cwnd;
9328 			}
9329 		}
9330 	}
9331 }
9332 #endif
9333 
9334 static int
9335 rack_note_dsack(struct tcp_rack *rack, tcp_seq start, tcp_seq end)
9336 {
9337 
9338 	uint32_t am, l_end;
9339 	int was_tlp = 0;
9340 
9341 	if (SEQ_GT(end, start))
9342 		am = end - start;
9343 	else
9344 		am = 0;
9345 	if ((rack->rc_last_tlp_acked_set ) &&
9346 	    (SEQ_GEQ(start, rack->r_ctl.last_tlp_acked_start)) &&
9347 	    (SEQ_LEQ(end, rack->r_ctl.last_tlp_acked_end))) {
9348 		/*
9349 		 * The DSACK is because of a TLP which we don't
9350 		 * do anything with the reordering window over since
9351 		 * it was not reordering that caused the DSACK but
9352 		 * our previous retransmit TLP.
9353 		 */
9354 		rack_log_dsack_event(rack, 7, __LINE__, start, end);
9355 		was_tlp = 1;
9356 		goto skip_dsack_round;
9357 	}
9358 	if (rack->rc_last_sent_tlp_seq_valid) {
9359 		l_end = rack->r_ctl.last_sent_tlp_seq + rack->r_ctl.last_sent_tlp_len;
9360 		if (SEQ_GEQ(start, rack->r_ctl.last_sent_tlp_seq) &&
9361 		    (SEQ_LEQ(end, l_end))) {
9362 			/*
9363 			 * This dsack is from the last sent TLP, ignore it
9364 			 * for reordering purposes.
9365 			 */
9366 			rack_log_dsack_event(rack, 7, __LINE__, start, end);
9367 			was_tlp = 1;
9368 			goto skip_dsack_round;
9369 		}
9370 	}
9371 	if (rack->rc_dsack_round_seen == 0) {
9372 		rack->rc_dsack_round_seen = 1;
9373 		rack->r_ctl.dsack_round_end = rack->rc_tp->snd_max;
9374 		rack->r_ctl.num_dsack++;
9375 		rack->r_ctl.dsack_persist = 16;	/* 16 is from the standard */
9376 		rack_log_dsack_event(rack, 2, __LINE__, 0, 0);
9377 	}
9378 skip_dsack_round:
9379 	/*
9380 	 * We keep track of how many DSACK blocks we get
9381 	 * after a recovery incident.
9382 	 */
9383 	rack->r_ctl.dsack_byte_cnt += am;
9384 	if (!IN_FASTRECOVERY(rack->rc_tp->t_flags) &&
9385 	    rack->r_ctl.retran_during_recovery &&
9386 	    (rack->r_ctl.dsack_byte_cnt >= rack->r_ctl.retran_during_recovery)) {
9387 		/*
9388 		 * False recovery most likely culprit is reordering. If
9389 		 * nothing else is missing we need to revert.
9390 		 */
9391 		rack->r_might_revert = 1;
9392 		rack_handle_might_revert(rack->rc_tp, rack);
9393 		rack->r_might_revert = 0;
9394 		rack->r_ctl.retran_during_recovery = 0;
9395 		rack->r_ctl.dsack_byte_cnt = 0;
9396 	}
9397 	return (was_tlp);
9398 }
9399 
9400 static uint32_t
9401 do_rack_compute_pipe(struct tcpcb *tp, struct tcp_rack *rack, uint32_t snd_una)
9402 {
9403 	return (((tp->snd_max - snd_una) - rack->r_ctl.rc_sacked) + rack->r_ctl.rc_holes_rxt);
9404 }
9405 
9406 static int32_t
9407 rack_compute_pipe(struct tcpcb *tp)
9408 {
9409 	return ((int32_t)do_rack_compute_pipe(tp,
9410 					      (struct tcp_rack *)tp->t_fb_ptr,
9411 					      tp->snd_una));
9412 }
9413 
9414 static void
9415 rack_update_prr(struct tcpcb *tp, struct tcp_rack *rack, uint32_t changed, tcp_seq th_ack)
9416 {
9417 	/* Deal with changed and PRR here (in recovery only) */
9418 	uint32_t pipe, snd_una;
9419 
9420 	rack->r_ctl.rc_prr_delivered += changed;
9421 
9422 	if (sbavail(&rack->rc_inp->inp_socket->so_snd) <= (tp->snd_max - tp->snd_una)) {
9423 		/*
9424 		 * It is all outstanding, we are application limited
9425 		 * and thus we don't need more room to send anything.
9426 		 * Note we use tp->snd_una here and not th_ack because
9427 		 * the data as yet not been cut from the sb.
9428 		 */
9429 		rack->r_ctl.rc_prr_sndcnt = 0;
9430 		return;
9431 	}
9432 	/* Compute prr_sndcnt */
9433 	if (SEQ_GT(tp->snd_una, th_ack)) {
9434 		snd_una = tp->snd_una;
9435 	} else {
9436 		snd_una = th_ack;
9437 	}
9438 	pipe = do_rack_compute_pipe(tp, rack, snd_una);
9439 	if (pipe > tp->snd_ssthresh) {
9440 		long sndcnt;
9441 
9442 		sndcnt = rack->r_ctl.rc_prr_delivered * tp->snd_ssthresh;
9443 		if (rack->r_ctl.rc_prr_recovery_fs > 0)
9444 			sndcnt /= (long)rack->r_ctl.rc_prr_recovery_fs;
9445 		else {
9446 			rack->r_ctl.rc_prr_sndcnt = 0;
9447 			rack_log_to_prr(rack, 9, 0, __LINE__);
9448 			sndcnt = 0;
9449 		}
9450 		sndcnt++;
9451 		if (sndcnt > (long)rack->r_ctl.rc_prr_out)
9452 			sndcnt -= rack->r_ctl.rc_prr_out;
9453 		else
9454 			sndcnt = 0;
9455 		rack->r_ctl.rc_prr_sndcnt = sndcnt;
9456 		rack_log_to_prr(rack, 10, 0, __LINE__);
9457 	} else {
9458 		uint32_t limit;
9459 
9460 		if (rack->r_ctl.rc_prr_delivered > rack->r_ctl.rc_prr_out)
9461 			limit = (rack->r_ctl.rc_prr_delivered - rack->r_ctl.rc_prr_out);
9462 		else
9463 			limit = 0;
9464 		if (changed > limit)
9465 			limit = changed;
9466 		limit += ctf_fixed_maxseg(tp);
9467 		if (tp->snd_ssthresh > pipe) {
9468 			rack->r_ctl.rc_prr_sndcnt = min((tp->snd_ssthresh - pipe), limit);
9469 			rack_log_to_prr(rack, 11, 0, __LINE__);
9470 		} else {
9471 			rack->r_ctl.rc_prr_sndcnt = min(0, limit);
9472 			rack_log_to_prr(rack, 12, 0, __LINE__);
9473 		}
9474 	}
9475 }
9476 
9477 static void
9478 rack_log_ack(struct tcpcb *tp, struct tcpopt *to, struct tcphdr *th, int entered_recovery, int dup_ack_struck)
9479 {
9480 	uint32_t changed;
9481 	struct tcp_rack *rack;
9482 	struct rack_sendmap *rsm;
9483 	struct sackblk sack, sack_blocks[TCP_MAX_SACK + 1];
9484 	register uint32_t th_ack;
9485 	int32_t i, j, k, num_sack_blks = 0;
9486 	uint32_t cts, acked, ack_point;
9487 	int loop_start = 0, moved_two = 0;
9488 	uint32_t tsused;
9489 
9490 
9491 	INP_WLOCK_ASSERT(tp->t_inpcb);
9492 	if (tcp_get_flags(th) & TH_RST) {
9493 		/* We don't log resets */
9494 		return;
9495 	}
9496 	rack = (struct tcp_rack *)tp->t_fb_ptr;
9497 	cts = tcp_get_usecs(NULL);
9498 	rsm = RB_MIN(rack_rb_tree_head, &rack->r_ctl.rc_mtree);
9499 	changed = 0;
9500 	th_ack = th->th_ack;
9501 	if (rack->sack_attack_disable == 0)
9502 		rack_do_decay(rack);
9503 	if (BYTES_THIS_ACK(tp, th) >= ctf_fixed_maxseg(rack->rc_tp)) {
9504 		/*
9505 		 * You only get credit for
9506 		 * MSS and greater (and you get extra
9507 		 * credit for larger cum-ack moves).
9508 		 */
9509 		int ac;
9510 
9511 		ac = BYTES_THIS_ACK(tp, th) / ctf_fixed_maxseg(rack->rc_tp);
9512 		rack->r_ctl.ack_count += ac;
9513 		counter_u64_add(rack_ack_total, ac);
9514 	}
9515 	if (rack->r_ctl.ack_count > 0xfff00000) {
9516 		/*
9517 		 * reduce the number to keep us under
9518 		 * a uint32_t.
9519 		 */
9520 		rack->r_ctl.ack_count /= 2;
9521 		rack->r_ctl.sack_count /= 2;
9522 	}
9523 	if (SEQ_GT(th_ack, tp->snd_una)) {
9524 		rack_log_progress_event(rack, tp, ticks, PROGRESS_UPDATE, __LINE__);
9525 		tp->t_acktime = ticks;
9526 	}
9527 	if (rsm && SEQ_GT(th_ack, rsm->r_start))
9528 		changed = th_ack - rsm->r_start;
9529 	if (changed) {
9530 		rack_process_to_cumack(tp, rack, th_ack, cts, to);
9531 	}
9532 	if ((to->to_flags & TOF_SACK) == 0) {
9533 		/* We are done nothing left and no sack. */
9534 		rack_handle_might_revert(tp, rack);
9535 		/*
9536 		 * For cases where we struck a dup-ack
9537 		 * with no SACK, add to the changes so
9538 		 * PRR will work right.
9539 		 */
9540 		if (dup_ack_struck && (changed == 0)) {
9541 			changed += ctf_fixed_maxseg(rack->rc_tp);
9542 		}
9543 		goto out;
9544 	}
9545 	/* Sack block processing */
9546 	if (SEQ_GT(th_ack, tp->snd_una))
9547 		ack_point = th_ack;
9548 	else
9549 		ack_point = tp->snd_una;
9550 	for (i = 0; i < to->to_nsacks; i++) {
9551 		bcopy((to->to_sacks + i * TCPOLEN_SACK),
9552 		      &sack, sizeof(sack));
9553 		sack.start = ntohl(sack.start);
9554 		sack.end = ntohl(sack.end);
9555 		if (SEQ_GT(sack.end, sack.start) &&
9556 		    SEQ_GT(sack.start, ack_point) &&
9557 		    SEQ_LT(sack.start, tp->snd_max) &&
9558 		    SEQ_GT(sack.end, ack_point) &&
9559 		    SEQ_LEQ(sack.end, tp->snd_max)) {
9560 			sack_blocks[num_sack_blks] = sack;
9561 			num_sack_blks++;
9562 		} else if (SEQ_LEQ(sack.start, th_ack) &&
9563 			   SEQ_LEQ(sack.end, th_ack)) {
9564 			int was_tlp;
9565 
9566 			was_tlp = rack_note_dsack(rack, sack.start, sack.end);
9567 			/*
9568 			 * Its a D-SACK block.
9569 			 */
9570 			tcp_record_dsack(tp, sack.start, sack.end, was_tlp);
9571 		}
9572 	}
9573 	if (rack->rc_dsack_round_seen) {
9574 		/* Is the dsack roound over? */
9575 		if (SEQ_GEQ(th_ack, rack->r_ctl.dsack_round_end)) {
9576 			/* Yes it is */
9577 			rack->rc_dsack_round_seen = 0;
9578 			rack_log_dsack_event(rack, 3, __LINE__, 0, 0);
9579 		}
9580 	}
9581 	/*
9582 	 * Sort the SACK blocks so we can update the rack scoreboard with
9583 	 * just one pass.
9584 	 */
9585 	num_sack_blks = sack_filter_blks(&rack->r_ctl.rack_sf, sack_blocks,
9586 					 num_sack_blks, th->th_ack);
9587 	ctf_log_sack_filter(rack->rc_tp, num_sack_blks, sack_blocks);
9588 	if (num_sack_blks == 0) {
9589 		/* Nothing to sack (DSACKs?) */
9590 		goto out_with_totals;
9591 	}
9592 	if (num_sack_blks < 2) {
9593 		/* Only one, we don't need to sort */
9594 		goto do_sack_work;
9595 	}
9596 	/* Sort the sacks */
9597 	for (i = 0; i < num_sack_blks; i++) {
9598 		for (j = i + 1; j < num_sack_blks; j++) {
9599 			if (SEQ_GT(sack_blocks[i].end, sack_blocks[j].end)) {
9600 				sack = sack_blocks[i];
9601 				sack_blocks[i] = sack_blocks[j];
9602 				sack_blocks[j] = sack;
9603 			}
9604 		}
9605 	}
9606 	/*
9607 	 * Now are any of the sack block ends the same (yes some
9608 	 * implementations send these)?
9609 	 */
9610 again:
9611 	if (num_sack_blks == 0)
9612 		goto out_with_totals;
9613 	if (num_sack_blks > 1) {
9614 		for (i = 0; i < num_sack_blks; i++) {
9615 			for (j = i + 1; j < num_sack_blks; j++) {
9616 				if (sack_blocks[i].end == sack_blocks[j].end) {
9617 					/*
9618 					 * Ok these two have the same end we
9619 					 * want the smallest end and then
9620 					 * throw away the larger and start
9621 					 * again.
9622 					 */
9623 					if (SEQ_LT(sack_blocks[j].start, sack_blocks[i].start)) {
9624 						/*
9625 						 * The second block covers
9626 						 * more area use that
9627 						 */
9628 						sack_blocks[i].start = sack_blocks[j].start;
9629 					}
9630 					/*
9631 					 * Now collapse out the dup-sack and
9632 					 * lower the count
9633 					 */
9634 					for (k = (j + 1); k < num_sack_blks; k++) {
9635 						sack_blocks[j].start = sack_blocks[k].start;
9636 						sack_blocks[j].end = sack_blocks[k].end;
9637 						j++;
9638 					}
9639 					num_sack_blks--;
9640 					goto again;
9641 				}
9642 			}
9643 		}
9644 	}
9645 do_sack_work:
9646 	/*
9647 	 * First lets look to see if
9648 	 * we have retransmitted and
9649 	 * can use the transmit next?
9650 	 */
9651 	rsm = TAILQ_FIRST(&rack->r_ctl.rc_tmap);
9652 	if (rsm &&
9653 	    SEQ_GT(sack_blocks[0].end, rsm->r_start) &&
9654 	    SEQ_LT(sack_blocks[0].start, rsm->r_end)) {
9655 		/*
9656 		 * We probably did the FR and the next
9657 		 * SACK in continues as we would expect.
9658 		 */
9659 		acked = rack_proc_sack_blk(tp, rack, &sack_blocks[0], to, &rsm, cts, &moved_two);
9660 		if (acked) {
9661 			rack->r_wanted_output = 1;
9662 			changed += acked;
9663 		}
9664 		if (num_sack_blks == 1) {
9665 			/*
9666 			 * This is what we would expect from
9667 			 * a normal implementation to happen
9668 			 * after we have retransmitted the FR,
9669 			 * i.e the sack-filter pushes down
9670 			 * to 1 block and the next to be retransmitted
9671 			 * is the sequence in the sack block (has more
9672 			 * are acked). Count this as ACK'd data to boost
9673 			 * up the chances of recovering any false positives.
9674 			 */
9675 			rack->r_ctl.ack_count += (acked / ctf_fixed_maxseg(rack->rc_tp));
9676 			counter_u64_add(rack_ack_total, (acked / ctf_fixed_maxseg(rack->rc_tp)));
9677 			counter_u64_add(rack_express_sack, 1);
9678 			if (rack->r_ctl.ack_count > 0xfff00000) {
9679 				/*
9680 				 * reduce the number to keep us under
9681 				 * a uint32_t.
9682 				 */
9683 				rack->r_ctl.ack_count /= 2;
9684 				rack->r_ctl.sack_count /= 2;
9685 			}
9686 			goto out_with_totals;
9687 		} else {
9688 			/*
9689 			 * Start the loop through the
9690 			 * rest of blocks, past the first block.
9691 			 */
9692 			moved_two = 0;
9693 			loop_start = 1;
9694 		}
9695 	}
9696 	/* Its a sack of some sort */
9697 	rack->r_ctl.sack_count++;
9698 	if (rack->r_ctl.sack_count > 0xfff00000) {
9699 		/*
9700 		 * reduce the number to keep us under
9701 		 * a uint32_t.
9702 		 */
9703 		rack->r_ctl.ack_count /= 2;
9704 		rack->r_ctl.sack_count /= 2;
9705 	}
9706 	counter_u64_add(rack_sack_total, 1);
9707 	if (rack->sack_attack_disable) {
9708 		/* An attacker disablement is in place */
9709 		if (num_sack_blks > 1) {
9710 			rack->r_ctl.sack_count += (num_sack_blks - 1);
9711 			rack->r_ctl.sack_moved_extra++;
9712 			counter_u64_add(rack_move_some, 1);
9713 			if (rack->r_ctl.sack_moved_extra > 0xfff00000) {
9714 				rack->r_ctl.sack_moved_extra /= 2;
9715 				rack->r_ctl.sack_noextra_move /= 2;
9716 			}
9717 		}
9718 		goto out;
9719 	}
9720 	rsm = rack->r_ctl.rc_sacklast;
9721 	for (i = loop_start; i < num_sack_blks; i++) {
9722 		acked = rack_proc_sack_blk(tp, rack, &sack_blocks[i], to, &rsm, cts, &moved_two);
9723 		if (acked) {
9724 			rack->r_wanted_output = 1;
9725 			changed += acked;
9726 		}
9727 		if (moved_two) {
9728 			/*
9729 			 * If we did not get a SACK for at least a MSS and
9730 			 * had to move at all, or if we moved more than our
9731 			 * threshold, it counts against the "extra" move.
9732 			 */
9733 			rack->r_ctl.sack_moved_extra += moved_two;
9734 			counter_u64_add(rack_move_some, 1);
9735 		} else {
9736 			/*
9737 			 * else we did not have to move
9738 			 * any more than we would expect.
9739 			 */
9740 			rack->r_ctl.sack_noextra_move++;
9741 			counter_u64_add(rack_move_none, 1);
9742 		}
9743 		if (moved_two && (acked < ctf_fixed_maxseg(rack->rc_tp))) {
9744 			/*
9745 			 * If the SACK was not a full MSS then
9746 			 * we add to sack_count the number of
9747 			 * MSS's (or possibly more than
9748 			 * a MSS if its a TSO send) we had to skip by.
9749 			 */
9750 			rack->r_ctl.sack_count += moved_two;
9751 			counter_u64_add(rack_sack_total, moved_two);
9752 		}
9753 		/*
9754 		 * Now we need to setup for the next
9755 		 * round. First we make sure we won't
9756 		 * exceed the size of our uint32_t on
9757 		 * the various counts, and then clear out
9758 		 * moved_two.
9759 		 */
9760 		if ((rack->r_ctl.sack_moved_extra > 0xfff00000) ||
9761 		    (rack->r_ctl.sack_noextra_move > 0xfff00000)) {
9762 			rack->r_ctl.sack_moved_extra /= 2;
9763 			rack->r_ctl.sack_noextra_move /= 2;
9764 		}
9765 		if (rack->r_ctl.sack_count > 0xfff00000) {
9766 			rack->r_ctl.ack_count /= 2;
9767 			rack->r_ctl.sack_count /= 2;
9768 		}
9769 		moved_two = 0;
9770 	}
9771 out_with_totals:
9772 	if (num_sack_blks > 1) {
9773 		/*
9774 		 * You get an extra stroke if
9775 		 * you have more than one sack-blk, this
9776 		 * could be where we are skipping forward
9777 		 * and the sack-filter is still working, or
9778 		 * it could be an attacker constantly
9779 		 * moving us.
9780 		 */
9781 		rack->r_ctl.sack_moved_extra++;
9782 		counter_u64_add(rack_move_some, 1);
9783 	}
9784 out:
9785 #ifdef NETFLIX_EXP_DETECTION
9786 	rack_do_detection(tp, rack, BYTES_THIS_ACK(tp, th), ctf_fixed_maxseg(rack->rc_tp));
9787 #endif
9788 	if (changed) {
9789 		/* Something changed cancel the rack timer */
9790 		rack_timer_cancel(tp, rack, rack->r_ctl.rc_rcvtime, __LINE__);
9791 	}
9792 	tsused = tcp_get_usecs(NULL);
9793 	rsm = tcp_rack_output(tp, rack, tsused);
9794 	if ((!IN_FASTRECOVERY(tp->t_flags)) &&
9795 	    rsm &&
9796 	    ((rsm->r_flags & RACK_MUST_RXT) == 0)) {
9797 		/* Enter recovery */
9798 		entered_recovery = 1;
9799 		rack_cong_signal(tp, CC_NDUPACK, tp->snd_una, __LINE__);
9800 		/*
9801 		 * When we enter recovery we need to assure we send
9802 		 * one packet.
9803 		 */
9804 		if (rack->rack_no_prr == 0) {
9805 			rack->r_ctl.rc_prr_sndcnt = ctf_fixed_maxseg(tp);
9806 			rack_log_to_prr(rack, 8, 0, __LINE__);
9807 		}
9808 		rack->r_timer_override = 1;
9809 		rack->r_early = 0;
9810 		rack->r_ctl.rc_agg_early = 0;
9811 	} else if (IN_FASTRECOVERY(tp->t_flags) &&
9812 		   rsm &&
9813 		   (rack->r_rr_config == 3)) {
9814 		/*
9815 		 * Assure we can output and we get no
9816 		 * remembered pace time except the retransmit.
9817 		 */
9818 		rack->r_timer_override = 1;
9819 		rack->r_ctl.rc_hpts_flags &= ~PACE_PKT_OUTPUT;
9820 		rack->r_ctl.rc_resend = rsm;
9821 	}
9822 	if (IN_FASTRECOVERY(tp->t_flags) &&
9823 	    (rack->rack_no_prr == 0) &&
9824 	    (entered_recovery == 0)) {
9825 		rack_update_prr(tp, rack, changed, th_ack);
9826 		if ((rsm && (rack->r_ctl.rc_prr_sndcnt >= ctf_fixed_maxseg(tp)) &&
9827 		     ((tcp_in_hpts(rack->rc_inp) == 0) &&
9828 		      ((rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT) == 0)))) {
9829 			/*
9830 			 * If you are pacing output you don't want
9831 			 * to override.
9832 			 */
9833 			rack->r_early = 0;
9834 			rack->r_ctl.rc_agg_early = 0;
9835 			rack->r_timer_override = 1;
9836 		}
9837 	}
9838 }
9839 
9840 static void
9841 rack_strike_dupack(struct tcp_rack *rack)
9842 {
9843 	struct rack_sendmap *rsm;
9844 
9845 	rsm = TAILQ_FIRST(&rack->r_ctl.rc_tmap);
9846 	while (rsm && (rsm->r_dupack >= DUP_ACK_THRESHOLD)) {
9847 		rsm = TAILQ_NEXT(rsm, r_tnext);
9848 		if (rsm->r_flags & RACK_MUST_RXT) {
9849 			/* Sendmap entries that are marked to
9850 			 * be retransmitted do not need dupack's
9851 			 * struck. We get these marks for a number
9852 			 * of reasons (rxt timeout with no sack,
9853 			 * mtu change, or rwnd collapses). When
9854 			 * these events occur, we know we must retransmit
9855 			 * them and mark the sendmap entries. Dupack counting
9856 			 * is not needed since we are already set to retransmit
9857 			 * it as soon as we can.
9858 			 */
9859 			continue;
9860 		}
9861 	}
9862 	if (rsm && (rsm->r_dupack < 0xff)) {
9863 		rsm->r_dupack++;
9864 		if (rsm->r_dupack >= DUP_ACK_THRESHOLD) {
9865 			struct timeval tv;
9866 			uint32_t cts;
9867 			/*
9868 			 * Here we see if we need to retransmit. For
9869 			 * a SACK type connection if enough time has passed
9870 			 * we will get a return of the rsm. For a non-sack
9871 			 * connection we will get the rsm returned if the
9872 			 * dupack value is 3 or more.
9873 			 */
9874 			cts = tcp_get_usecs(&tv);
9875 			rack->r_ctl.rc_resend = tcp_rack_output(rack->rc_tp, rack, cts);
9876 			if (rack->r_ctl.rc_resend != NULL) {
9877 				if (!IN_FASTRECOVERY(rack->rc_tp->t_flags)) {
9878 					rack_cong_signal(rack->rc_tp, CC_NDUPACK,
9879 							 rack->rc_tp->snd_una, __LINE__);
9880 				}
9881 				rack->r_wanted_output = 1;
9882 				rack->r_timer_override = 1;
9883 				rack_log_retran_reason(rack, rsm, __LINE__, 1, 3);
9884 			}
9885 		} else {
9886 			rack_log_retran_reason(rack, rsm, __LINE__, 0, 3);
9887 		}
9888 	}
9889 }
9890 
9891 static void
9892 rack_check_bottom_drag(struct tcpcb *tp,
9893 		       struct tcp_rack *rack,
9894 		       struct socket *so, int32_t acked)
9895 {
9896 	uint32_t segsiz, minseg;
9897 
9898 	segsiz = ctf_fixed_maxseg(tp);
9899 	minseg = segsiz;
9900 
9901 	if (tp->snd_max == tp->snd_una) {
9902 		/*
9903 		 * We are doing dynamic pacing and we are way
9904 		 * under. Basically everything got acked while
9905 		 * we were still waiting on the pacer to expire.
9906 		 *
9907 		 * This means we need to boost the b/w in
9908 		 * addition to any earlier boosting of
9909 		 * the multiplier.
9910 		 */
9911 		rack->rc_dragged_bottom = 1;
9912 		rack_validate_multipliers_at_or_above100(rack);
9913 		/*
9914 		 * Lets use the segment bytes acked plus
9915 		 * the lowest RTT seen as the basis to
9916 		 * form a b/w estimate. This will be off
9917 		 * due to the fact that the true estimate
9918 		 * should be around 1/2 the time of the RTT
9919 		 * but we can settle for that.
9920 		 */
9921 		if ((rack->r_ctl.rack_rs.rs_flags & RACK_RTT_VALID) &&
9922 		    acked) {
9923 			uint64_t bw, calc_bw, rtt;
9924 
9925 			rtt = rack->r_ctl.rack_rs.rs_us_rtt;
9926 			if (rtt == 0) {
9927 				/* no us sample is there a ms one? */
9928 				if (rack->r_ctl.rack_rs.rs_rtt_lowest) {
9929 					rtt = rack->r_ctl.rack_rs.rs_rtt_lowest;
9930 				} else {
9931 					goto no_measurement;
9932 				}
9933 			}
9934 			bw = acked;
9935 			calc_bw = bw * 1000000;
9936 			calc_bw /= rtt;
9937 			if (rack->r_ctl.last_max_bw &&
9938 			    (rack->r_ctl.last_max_bw < calc_bw)) {
9939 				/*
9940 				 * If we have a last calculated max bw
9941 				 * enforce it.
9942 				 */
9943 				calc_bw = rack->r_ctl.last_max_bw;
9944 			}
9945 			/* now plop it in */
9946 			if (rack->rc_gp_filled == 0) {
9947 				if (calc_bw > ONE_POINT_TWO_MEG) {
9948 					/*
9949 					 * If we have no measurement
9950 					 * don't let us set in more than
9951 					 * 1.2Mbps. If we are still too
9952 					 * low after pacing with this we
9953 					 * will hopefully have a max b/w
9954 					 * available to sanity check things.
9955 					 */
9956 					calc_bw = ONE_POINT_TWO_MEG;
9957 				}
9958 				rack->r_ctl.rc_rtt_diff = 0;
9959 				rack->r_ctl.gp_bw = calc_bw;
9960 				rack->rc_gp_filled = 1;
9961 				if (rack->r_ctl.num_measurements < RACK_REQ_AVG)
9962 					rack->r_ctl.num_measurements = RACK_REQ_AVG;
9963 				rack_set_pace_segments(rack->rc_tp, rack, __LINE__, NULL);
9964 			} else if (calc_bw > rack->r_ctl.gp_bw) {
9965 				rack->r_ctl.rc_rtt_diff = 0;
9966 				if (rack->r_ctl.num_measurements < RACK_REQ_AVG)
9967 					rack->r_ctl.num_measurements = RACK_REQ_AVG;
9968 				rack->r_ctl.gp_bw = calc_bw;
9969 				rack_set_pace_segments(rack->rc_tp, rack, __LINE__, NULL);
9970 			} else
9971 				rack_increase_bw_mul(rack, -1, 0, 0, 1);
9972 			if ((rack->gp_ready == 0) &&
9973 			    (rack->r_ctl.num_measurements >= rack->r_ctl.req_measurements)) {
9974 				/* We have enough measurements now */
9975 				rack->gp_ready = 1;
9976 				rack_set_cc_pacing(rack);
9977 				if (rack->defer_options)
9978 					rack_apply_deferred_options(rack);
9979 			}
9980 			/*
9981 			 * For acks over 1mss we do a extra boost to simulate
9982 			 * where we would get 2 acks (we want 110 for the mul).
9983 			 */
9984 			if (acked > segsiz)
9985 				rack_increase_bw_mul(rack, -1, 0, 0, 1);
9986 		} else {
9987 			/*
9988 			 * zero rtt possibly?, settle for just an old increase.
9989 			 */
9990 no_measurement:
9991 			rack_increase_bw_mul(rack, -1, 0, 0, 1);
9992 		}
9993 	} else if ((IN_FASTRECOVERY(tp->t_flags) == 0) &&
9994 		   (sbavail(&so->so_snd) > max((segsiz * (4 + rack_req_segs)),
9995 					       minseg)) &&
9996 		   (rack->r_ctl.cwnd_to_use > max((segsiz * (rack_req_segs + 2)), minseg)) &&
9997 		   (tp->snd_wnd > max((segsiz * (rack_req_segs + 2)), minseg)) &&
9998 		   (ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked) <=
9999 		    (segsiz * rack_req_segs))) {
10000 		/*
10001 		 * We are doing dynamic GP pacing and
10002 		 * we have everything except 1MSS or less
10003 		 * bytes left out. We are still pacing away.
10004 		 * And there is data that could be sent, This
10005 		 * means we are inserting delayed ack time in
10006 		 * our measurements because we are pacing too slow.
10007 		 */
10008 		rack_validate_multipliers_at_or_above100(rack);
10009 		rack->rc_dragged_bottom = 1;
10010 		rack_increase_bw_mul(rack, -1, 0, 0, 1);
10011 	}
10012 }
10013 
10014 
10015 
10016 static void
10017 rack_gain_for_fastoutput(struct tcp_rack *rack, struct tcpcb *tp, struct socket *so, uint32_t acked_amount)
10018 {
10019 	/*
10020 	 * The fast output path is enabled and we
10021 	 * have moved the cumack forward. Lets see if
10022 	 * we can expand forward the fast path length by
10023 	 * that amount. What we would ideally like to
10024 	 * do is increase the number of bytes in the
10025 	 * fast path block (left_to_send) by the
10026 	 * acked amount. However we have to gate that
10027 	 * by two factors:
10028 	 * 1) The amount outstanding and the rwnd of the peer
10029 	 *    (i.e. we don't want to exceed the rwnd of the peer).
10030 	 *    <and>
10031 	 * 2) The amount of data left in the socket buffer (i.e.
10032 	 *    we can't send beyond what is in the buffer).
10033 	 *
10034 	 * Note that this does not take into account any increase
10035 	 * in the cwnd. We will only extend the fast path by
10036 	 * what was acked.
10037 	 */
10038 	uint32_t new_total, gating_val;
10039 
10040 	new_total = acked_amount + rack->r_ctl.fsb.left_to_send;
10041 	gating_val = min((sbavail(&so->so_snd) - (tp->snd_max - tp->snd_una)),
10042 			 (tp->snd_wnd - (tp->snd_max - tp->snd_una)));
10043 	if (new_total <= gating_val) {
10044 		/* We can increase left_to_send by the acked amount */
10045 		counter_u64_add(rack_extended_rfo, 1);
10046 		rack->r_ctl.fsb.left_to_send = new_total;
10047 		KASSERT((rack->r_ctl.fsb.left_to_send <= (sbavail(&rack->rc_inp->inp_socket->so_snd) - (tp->snd_max - tp->snd_una))),
10048 			("rack:%p left_to_send:%u sbavail:%u out:%u",
10049 			 rack, rack->r_ctl.fsb.left_to_send,
10050 			 sbavail(&rack->rc_inp->inp_socket->so_snd),
10051 			 (tp->snd_max - tp->snd_una)));
10052 
10053 	}
10054 }
10055 
10056 static void
10057 rack_adjust_sendmap(struct tcp_rack *rack, struct sockbuf *sb, tcp_seq snd_una)
10058 {
10059 	/*
10060 	 * Here any sendmap entry that points to the
10061 	 * beginning mbuf must be adjusted to the correct
10062 	 * offset. This must be called with:
10063 	 * 1) The socket buffer locked
10064 	 * 2) snd_una adjusted to its new postion.
10065 	 *
10066 	 * Note that (2) implies rack_ack_received has also
10067 	 * been called.
10068 	 *
10069 	 * We grab the first mbuf in the socket buffer and
10070 	 * then go through the front of the sendmap, recalculating
10071 	 * the stored offset for any sendmap entry that has
10072 	 * that mbuf. We must use the sb functions to do this
10073 	 * since its possible an add was done has well as
10074 	 * the subtraction we may have just completed. This should
10075 	 * not be a penalty though, since we just referenced the sb
10076 	 * to go in and trim off the mbufs that we freed (of course
10077 	 * there will be a penalty for the sendmap references though).
10078 	 */
10079 	struct mbuf *m;
10080 	struct rack_sendmap *rsm;
10081 
10082 	SOCKBUF_LOCK_ASSERT(sb);
10083 	m = sb->sb_mb;
10084 	rsm = RB_MIN(rack_rb_tree_head, &rack->r_ctl.rc_mtree);
10085 	if ((rsm == NULL) || (m == NULL)) {
10086 		/* Nothing outstanding */
10087 		return;
10088 	}
10089 	while (rsm->m && (rsm->m == m)) {
10090 		/* one to adjust */
10091 #ifdef INVARIANTS
10092 		struct mbuf *tm;
10093 		uint32_t soff;
10094 
10095 		tm = sbsndmbuf(sb, (rsm->r_start - snd_una), &soff);
10096 		if (rsm->orig_m_len != m->m_len) {
10097 			rack_adjust_orig_mlen(rsm);
10098 		}
10099 		if (rsm->soff != soff) {
10100 			/*
10101 			 * This is not a fatal error, we anticipate it
10102 			 * might happen (the else code), so we count it here
10103 			 * so that under invariant we can see that it really
10104 			 * does happen.
10105 			 */
10106 			counter_u64_add(rack_adjust_map_bw, 1);
10107 		}
10108 		rsm->m = tm;
10109 		rsm->soff = soff;
10110 		if (tm)
10111 			rsm->orig_m_len = rsm->m->m_len;
10112 		else
10113 			rsm->orig_m_len = 0;
10114 #else
10115 		rsm->m = sbsndmbuf(sb, (rsm->r_start - snd_una), &rsm->soff);
10116 		if (rsm->m)
10117 			rsm->orig_m_len = rsm->m->m_len;
10118 		else
10119 			rsm->orig_m_len = 0;
10120 #endif
10121 		rsm = RB_NEXT(rack_rb_tree_head, &rack->r_ctl.rc_mtree,
10122 			      rsm);
10123 		if (rsm == NULL)
10124 			break;
10125 	}
10126 }
10127 
10128 /*
10129  * Return value of 1, we do not need to call rack_process_data().
10130  * return value of 0, rack_process_data can be called.
10131  * For ret_val if its 0 the TCP is locked, if its non-zero
10132  * its unlocked and probably unsafe to touch the TCB.
10133  */
10134 static int
10135 rack_process_ack(struct mbuf *m, struct tcphdr *th, struct socket *so,
10136     struct tcpcb *tp, struct tcpopt *to,
10137     uint32_t tiwin, int32_t tlen,
10138     int32_t * ofia, int32_t thflags, int32_t *ret_val)
10139 {
10140 	int32_t ourfinisacked = 0;
10141 	int32_t nsegs, acked_amount;
10142 	int32_t acked;
10143 	struct mbuf *mfree;
10144 	struct tcp_rack *rack;
10145 	int32_t under_pacing = 0;
10146 	int32_t recovery = 0;
10147 
10148 	rack = (struct tcp_rack *)tp->t_fb_ptr;
10149 	if (SEQ_GT(th->th_ack, tp->snd_max)) {
10150 		__ctf_do_dropafterack(m, tp, th, thflags, tlen, ret_val,
10151 				      &rack->r_ctl.challenge_ack_ts,
10152 				      &rack->r_ctl.challenge_ack_cnt);
10153 		rack->r_wanted_output = 1;
10154 		return (1);
10155 	}
10156 	if (rack->gp_ready &&
10157 	    (rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT)) {
10158 		under_pacing = 1;
10159 	}
10160 	if (SEQ_GEQ(th->th_ack, tp->snd_una) || to->to_nsacks) {
10161 		int in_rec, dup_ack_struck = 0;
10162 
10163 		in_rec = IN_FASTRECOVERY(tp->t_flags);
10164 		if (rack->rc_in_persist) {
10165 			tp->t_rxtshift = 0;
10166 			RACK_TCPT_RANGESET(tp->t_rxtcur, RACK_REXMTVAL(tp),
10167 				      rack_rto_min, rack_rto_max, rack->r_ctl.timer_slop);
10168 		}
10169 		if ((th->th_ack == tp->snd_una) &&
10170 		    (tiwin == tp->snd_wnd) &&
10171 		    ((to->to_flags & TOF_SACK) == 0)) {
10172 			rack_strike_dupack(rack);
10173 			dup_ack_struck = 1;
10174 		}
10175 		rack_log_ack(tp, to, th, ((in_rec == 0) && IN_FASTRECOVERY(tp->t_flags)), dup_ack_struck);
10176 	}
10177 	if (__predict_false(SEQ_LEQ(th->th_ack, tp->snd_una))) {
10178 		/*
10179 		 * Old ack, behind (or duplicate to) the last one rcv'd
10180 		 * Note: We mark reordering is occuring if its
10181 		 * less than and we have not closed our window.
10182 		 */
10183 		if (SEQ_LT(th->th_ack, tp->snd_una) && (sbspace(&so->so_rcv) > ctf_fixed_maxseg(tp))) {
10184 			rack->r_ctl.rc_reorder_ts = tcp_tv_to_usectick(&rack->r_ctl.act_rcv_time);
10185 		}
10186 		return (0);
10187 	}
10188 	/*
10189 	 * If we reach this point, ACK is not a duplicate, i.e., it ACKs
10190 	 * something we sent.
10191 	 */
10192 	if (tp->t_flags & TF_NEEDSYN) {
10193 		/*
10194 		 * T/TCP: Connection was half-synchronized, and our SYN has
10195 		 * been ACK'd (so connection is now fully synchronized).  Go
10196 		 * to non-starred state, increment snd_una for ACK of SYN,
10197 		 * and check if we can do window scaling.
10198 		 */
10199 		tp->t_flags &= ~TF_NEEDSYN;
10200 		tp->snd_una++;
10201 		/* Do window scaling? */
10202 		if ((tp->t_flags & (TF_RCVD_SCALE | TF_REQ_SCALE)) ==
10203 		    (TF_RCVD_SCALE | TF_REQ_SCALE)) {
10204 			tp->rcv_scale = tp->request_r_scale;
10205 			/* Send window already scaled. */
10206 		}
10207 	}
10208 	nsegs = max(1, m->m_pkthdr.lro_nsegs);
10209 	INP_WLOCK_ASSERT(tp->t_inpcb);
10210 
10211 	acked = BYTES_THIS_ACK(tp, th);
10212 	if (acked) {
10213 		/*
10214 		 * Any time we move the cum-ack forward clear
10215 		 * keep-alive tied probe-not-answered. The
10216 		 * persists clears its own on entry.
10217 		 */
10218 		rack->probe_not_answered = 0;
10219 	}
10220 	KMOD_TCPSTAT_ADD(tcps_rcvackpack, nsegs);
10221 	KMOD_TCPSTAT_ADD(tcps_rcvackbyte, acked);
10222 	/*
10223 	 * If we just performed our first retransmit, and the ACK arrives
10224 	 * within our recovery window, then it was a mistake to do the
10225 	 * retransmit in the first place.  Recover our original cwnd and
10226 	 * ssthresh, and proceed to transmit where we left off.
10227 	 */
10228 	if ((tp->t_flags & TF_PREVVALID) &&
10229 	    ((tp->t_flags & TF_RCVD_TSTMP) == 0)) {
10230 		tp->t_flags &= ~TF_PREVVALID;
10231 		if (tp->t_rxtshift == 1 &&
10232 		    (int)(ticks - tp->t_badrxtwin) < 0)
10233 			rack_cong_signal(tp, CC_RTO_ERR, th->th_ack, __LINE__);
10234 	}
10235 	if (acked) {
10236 		/* assure we are not backed off */
10237 		tp->t_rxtshift = 0;
10238 		RACK_TCPT_RANGESET(tp->t_rxtcur, RACK_REXMTVAL(tp),
10239 			      rack_rto_min, rack_rto_max, rack->r_ctl.timer_slop);
10240 		rack->rc_tlp_in_progress = 0;
10241 		rack->r_ctl.rc_tlp_cnt_out = 0;
10242 		/*
10243 		 * If it is the RXT timer we want to
10244 		 * stop it, so we can restart a TLP.
10245 		 */
10246 		if (rack->r_ctl.rc_hpts_flags & PACE_TMR_RXT)
10247 			rack_timer_cancel(tp, rack, rack->r_ctl.rc_rcvtime, __LINE__);
10248 #ifdef NETFLIX_HTTP_LOGGING
10249 		tcp_http_check_for_comp(rack->rc_tp, th->th_ack);
10250 #endif
10251 	}
10252 	/*
10253 	 * If we have a timestamp reply, update smoothed round trip time. If
10254 	 * no timestamp is present but transmit timer is running and timed
10255 	 * sequence number was acked, update smoothed round trip time. Since
10256 	 * we now have an rtt measurement, cancel the timer backoff (cf.,
10257 	 * Phil Karn's retransmit alg.). Recompute the initial retransmit
10258 	 * timer.
10259 	 *
10260 	 * Some boxes send broken timestamp replies during the SYN+ACK
10261 	 * phase, ignore timestamps of 0 or we could calculate a huge RTT
10262 	 * and blow up the retransmit timer.
10263 	 */
10264 	/*
10265 	 * If all outstanding data is acked, stop retransmit timer and
10266 	 * remember to restart (more output or persist). If there is more
10267 	 * data to be acked, restart retransmit timer, using current
10268 	 * (possibly backed-off) value.
10269 	 */
10270 	if (acked == 0) {
10271 		if (ofia)
10272 			*ofia = ourfinisacked;
10273 		return (0);
10274 	}
10275 	if (IN_RECOVERY(tp->t_flags)) {
10276 		if (SEQ_LT(th->th_ack, tp->snd_recover) &&
10277 		    (SEQ_LT(th->th_ack, tp->snd_max))) {
10278 			tcp_rack_partialack(tp);
10279 		} else {
10280 			rack_post_recovery(tp, th->th_ack);
10281 			recovery = 1;
10282 		}
10283 	}
10284 	/*
10285 	 * Let the congestion control algorithm update congestion control
10286 	 * related information. This typically means increasing the
10287 	 * congestion window.
10288 	 */
10289 	rack_ack_received(tp, rack, th->th_ack, nsegs, CC_ACK, recovery);
10290 	SOCKBUF_LOCK(&so->so_snd);
10291 	acked_amount = min(acked, (int)sbavail(&so->so_snd));
10292 	tp->snd_wnd -= acked_amount;
10293 	mfree = sbcut_locked(&so->so_snd, acked_amount);
10294 	if ((sbused(&so->so_snd) == 0) &&
10295 	    (acked > acked_amount) &&
10296 	    (tp->t_state >= TCPS_FIN_WAIT_1) &&
10297 	    (tp->t_flags & TF_SENTFIN)) {
10298 		/*
10299 		 * We must be sure our fin
10300 		 * was sent and acked (we can be
10301 		 * in FIN_WAIT_1 without having
10302 		 * sent the fin).
10303 		 */
10304 		ourfinisacked = 1;
10305 	}
10306 	tp->snd_una = th->th_ack;
10307 	if (acked_amount && sbavail(&so->so_snd))
10308 		rack_adjust_sendmap(rack, &so->so_snd, tp->snd_una);
10309 	rack_log_wakeup(tp,rack, &so->so_snd, acked, 2);
10310 	/* NB: sowwakeup_locked() does an implicit unlock. */
10311 	sowwakeup_locked(so);
10312 	m_freem(mfree);
10313 	if (SEQ_GT(tp->snd_una, tp->snd_recover))
10314 		tp->snd_recover = tp->snd_una;
10315 
10316 	if (SEQ_LT(tp->snd_nxt, tp->snd_una)) {
10317 		tp->snd_nxt = tp->snd_una;
10318 	}
10319 	if (under_pacing &&
10320 	    (rack->use_fixed_rate == 0) &&
10321 	    (rack->in_probe_rtt == 0) &&
10322 	    rack->rc_gp_dyn_mul &&
10323 	    rack->rc_always_pace) {
10324 		/* Check if we are dragging bottom */
10325 		rack_check_bottom_drag(tp, rack, so, acked);
10326 	}
10327 	if (tp->snd_una == tp->snd_max) {
10328 		/* Nothing left outstanding */
10329 		tp->t_flags &= ~TF_PREVVALID;
10330 		rack->r_ctl.rc_went_idle_time = tcp_get_usecs(NULL);
10331 		rack->r_ctl.retran_during_recovery = 0;
10332 		rack->r_ctl.dsack_byte_cnt = 0;
10333 		if (rack->r_ctl.rc_went_idle_time == 0)
10334 			rack->r_ctl.rc_went_idle_time = 1;
10335 		rack_log_progress_event(rack, tp, 0, PROGRESS_CLEAR, __LINE__);
10336 		if (sbavail(&tp->t_inpcb->inp_socket->so_snd) == 0)
10337 			tp->t_acktime = 0;
10338 		rack_timer_cancel(tp, rack, rack->r_ctl.rc_rcvtime, __LINE__);
10339 		/* Set need output so persist might get set */
10340 		rack->r_wanted_output = 1;
10341 		sack_filter_clear(&rack->r_ctl.rack_sf, tp->snd_una);
10342 		if ((tp->t_state >= TCPS_FIN_WAIT_1) &&
10343 		    (sbavail(&so->so_snd) == 0) &&
10344 		    (tp->t_flags2 & TF2_DROP_AF_DATA)) {
10345 			/*
10346 			 * The socket was gone and the
10347 			 * peer sent data (now or in the past), time to
10348 			 * reset him.
10349 			 */
10350 			*ret_val = 1;
10351 			/* tcp_close will kill the inp pre-log the Reset */
10352 			tcp_log_end_status(tp, TCP_EI_STATUS_SERVER_RST);
10353 			tp = tcp_close(tp);
10354 			ctf_do_dropwithreset(m, tp, th, BANDLIM_UNLIMITED, tlen);
10355 			return (1);
10356 		}
10357 	}
10358 	if (ofia)
10359 		*ofia = ourfinisacked;
10360 	return (0);
10361 }
10362 
10363 
10364 static void
10365 rack_log_collapse(struct tcp_rack *rack, uint32_t cnt, uint32_t split, uint32_t out, int line,
10366 		  int dir, uint32_t flags, struct rack_sendmap *rsm)
10367 {
10368 	if (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
10369 		union tcp_log_stackspecific log;
10370 		struct timeval tv;
10371 
10372 		memset(&log, 0, sizeof(log));
10373 		log.u_bbr.flex1 = cnt;
10374 		log.u_bbr.flex2 = split;
10375 		log.u_bbr.flex3 = out;
10376 		log.u_bbr.flex4 = line;
10377 		log.u_bbr.flex5 = rack->r_must_retran;
10378 		log.u_bbr.flex6 = flags;
10379 		log.u_bbr.flex7 = rack->rc_has_collapsed;
10380 		log.u_bbr.flex8 = dir;	/*
10381 					 * 1 is collapsed, 0 is uncollapsed,
10382 					 * 2 is log of a rsm being marked, 3 is a split.
10383 					 */
10384 		if (rsm == NULL)
10385 			log.u_bbr.rttProp = 0;
10386 		else
10387 			log.u_bbr.rttProp = (uint64_t)rsm;
10388 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
10389 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
10390 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
10391 		    &rack->rc_inp->inp_socket->so_rcv,
10392 		    &rack->rc_inp->inp_socket->so_snd,
10393 		    TCP_RACK_LOG_COLLAPSE, 0,
10394 		    0, &log, false, &tv);
10395 	}
10396 }
10397 
10398 static void
10399 rack_collapsed_window(struct tcp_rack *rack, uint32_t out, int line)
10400 {
10401 	/*
10402 	 * Here all we do is mark the collapsed point and set the flag.
10403 	 * This may happen again and again, but there is no
10404 	 * sense splitting our map until we know where the
10405 	 * peer finally lands in the collapse.
10406 	 */
10407 	rack_trace_point(rack, RACK_TP_COLLAPSED_WND);
10408 	if ((rack->rc_has_collapsed == 0) ||
10409 	    (rack->r_ctl.last_collapse_point != (rack->rc_tp->snd_una + rack->rc_tp->snd_wnd)))
10410 		counter_u64_add(rack_collapsed_win_seen, 1);
10411 	rack->r_ctl.last_collapse_point = rack->rc_tp->snd_una + rack->rc_tp->snd_wnd;
10412 	rack->r_ctl.high_collapse_point = rack->rc_tp->snd_max;
10413 	rack->rc_has_collapsed = 1;
10414 	rack->r_collapse_point_valid = 1;
10415 	rack_log_collapse(rack, 0, 0, rack->r_ctl.last_collapse_point, line, 1, 0, NULL);
10416 }
10417 
10418 static void
10419 rack_un_collapse_window(struct tcp_rack *rack, int line)
10420 {
10421 	struct rack_sendmap *nrsm, *rsm, fe;
10422 	int cnt = 0, split = 0;
10423 #ifdef INVARIANTS
10424 	struct rack_sendmap *insret;
10425 #endif
10426 
10427 	memset(&fe, 0, sizeof(fe));
10428 	rack->rc_has_collapsed = 0;
10429 	fe.r_start = rack->r_ctl.last_collapse_point;
10430 	rsm = RB_FIND(rack_rb_tree_head, &rack->r_ctl.rc_mtree, &fe);
10431 	if (rsm == NULL) {
10432 		/* Nothing to do maybe the peer ack'ed it all */
10433 		rack_log_collapse(rack, 0, 0, ctf_outstanding(rack->rc_tp), line, 0, 0, NULL);
10434 		return;
10435 	}
10436 	/* Now do we need to split this one? */
10437 	if (SEQ_GT(rack->r_ctl.last_collapse_point, rsm->r_start)) {
10438 		rack_log_collapse(rack, rsm->r_start, rsm->r_end,
10439 				  rack->r_ctl.last_collapse_point, line, 3, rsm->r_flags, rsm);
10440 		nrsm = rack_alloc_limit(rack, RACK_LIMIT_TYPE_SPLIT);
10441 		if (nrsm == NULL) {
10442 			/* We can't get a rsm, mark all? */
10443 			nrsm = rsm;
10444 			goto no_split;
10445 		}
10446 		/* Clone it */
10447 		split = 1;
10448 		rack_clone_rsm(rack, nrsm, rsm, rack->r_ctl.last_collapse_point);
10449 #ifndef INVARIANTS
10450 		(void)RB_INSERT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, nrsm);
10451 #else
10452 		insret = RB_INSERT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, nrsm);
10453 		if (insret != NULL) {
10454 			panic("Insert in rb tree of %p fails ret:%p rack:%p rsm:%p",
10455 			      nrsm, insret, rack, rsm);
10456 		}
10457 #endif
10458 		rack_log_map_chg(rack->rc_tp, rack, NULL, rsm, nrsm, MAP_SPLIT,
10459 				 rack->r_ctl.last_collapse_point, __LINE__);
10460 		if (rsm->r_in_tmap) {
10461 			TAILQ_INSERT_AFTER(&rack->r_ctl.rc_tmap, rsm, nrsm, r_tnext);
10462 			nrsm->r_in_tmap = 1;
10463 		}
10464 		/*
10465 		 * Set in the new RSM as the
10466 		 * collapsed starting point
10467 		 */
10468 		rsm = nrsm;
10469 	}
10470 no_split:
10471 	RB_FOREACH_FROM(nrsm, rack_rb_tree_head, rsm) {
10472 		nrsm->r_flags |= RACK_RWND_COLLAPSED;
10473 		rack_log_collapse(rack, nrsm->r_start, nrsm->r_end, 0, line, 4, nrsm->r_flags, nrsm);
10474 		cnt++;
10475 	}
10476 	if (cnt) {
10477 		counter_u64_add(rack_collapsed_win, 1);
10478 	}
10479 	rack_log_collapse(rack, cnt, split, ctf_outstanding(rack->rc_tp), line, 0, 0, NULL);
10480 }
10481 
10482 static void
10483 rack_handle_delayed_ack(struct tcpcb *tp, struct tcp_rack *rack,
10484 			int32_t tlen, int32_t tfo_syn)
10485 {
10486 	if (DELAY_ACK(tp, tlen) || tfo_syn) {
10487 		if (rack->rc_dack_mode &&
10488 		    (tlen > 500) &&
10489 		    (rack->rc_dack_toggle == 1)) {
10490 			goto no_delayed_ack;
10491 		}
10492 		rack_timer_cancel(tp, rack,
10493 				  rack->r_ctl.rc_rcvtime, __LINE__);
10494 		tp->t_flags |= TF_DELACK;
10495 	} else {
10496 no_delayed_ack:
10497 		rack->r_wanted_output = 1;
10498 		tp->t_flags |= TF_ACKNOW;
10499 		if (rack->rc_dack_mode) {
10500 			if (tp->t_flags & TF_DELACK)
10501 				rack->rc_dack_toggle = 1;
10502 			else
10503 				rack->rc_dack_toggle = 0;
10504 		}
10505 	}
10506 }
10507 
10508 static void
10509 rack_validate_fo_sendwin_up(struct tcpcb *tp, struct tcp_rack *rack)
10510 {
10511 	/*
10512 	 * If fast output is in progress, lets validate that
10513 	 * the new window did not shrink on us and make it
10514 	 * so fast output should end.
10515 	 */
10516 	if (rack->r_fast_output) {
10517 		uint32_t out;
10518 
10519 		/*
10520 		 * Calculate what we will send if left as is
10521 		 * and compare that to our send window.
10522 		 */
10523 		out = ctf_outstanding(tp);
10524 		if ((out + rack->r_ctl.fsb.left_to_send) > tp->snd_wnd) {
10525 			/* ok we have an issue */
10526 			if (out >= tp->snd_wnd) {
10527 				/* Turn off fast output the window is met or collapsed */
10528 				rack->r_fast_output = 0;
10529 			} else {
10530 				/* we have some room left */
10531 				rack->r_ctl.fsb.left_to_send = tp->snd_wnd - out;
10532 				if (rack->r_ctl.fsb.left_to_send < ctf_fixed_maxseg(tp)) {
10533 					/* If not at least 1 full segment never mind */
10534 					rack->r_fast_output = 0;
10535 				}
10536 			}
10537 		}
10538 	}
10539 }
10540 
10541 
10542 /*
10543  * Return value of 1, the TCB is unlocked and most
10544  * likely gone, return value of 0, the TCP is still
10545  * locked.
10546  */
10547 static int
10548 rack_process_data(struct mbuf *m, struct tcphdr *th, struct socket *so,
10549     struct tcpcb *tp, int32_t drop_hdrlen, int32_t tlen,
10550     uint32_t tiwin, int32_t thflags, int32_t nxt_pkt)
10551 {
10552 	/*
10553 	 * Update window information. Don't look at window if no ACK: TAC's
10554 	 * send garbage on first SYN.
10555 	 */
10556 	int32_t nsegs;
10557 	int32_t tfo_syn;
10558 	struct tcp_rack *rack;
10559 
10560 	rack = (struct tcp_rack *)tp->t_fb_ptr;
10561 	INP_WLOCK_ASSERT(tp->t_inpcb);
10562 	nsegs = max(1, m->m_pkthdr.lro_nsegs);
10563 	if ((thflags & TH_ACK) &&
10564 	    (SEQ_LT(tp->snd_wl1, th->th_seq) ||
10565 	    (tp->snd_wl1 == th->th_seq && (SEQ_LT(tp->snd_wl2, th->th_ack) ||
10566 	    (tp->snd_wl2 == th->th_ack && tiwin > tp->snd_wnd))))) {
10567 		/* keep track of pure window updates */
10568 		if (tlen == 0 &&
10569 		    tp->snd_wl2 == th->th_ack && tiwin > tp->snd_wnd)
10570 			KMOD_TCPSTAT_INC(tcps_rcvwinupd);
10571 		tp->snd_wnd = tiwin;
10572 		rack_validate_fo_sendwin_up(tp, rack);
10573 		tp->snd_wl1 = th->th_seq;
10574 		tp->snd_wl2 = th->th_ack;
10575 		if (tp->snd_wnd > tp->max_sndwnd)
10576 			tp->max_sndwnd = tp->snd_wnd;
10577 		rack->r_wanted_output = 1;
10578 	} else if (thflags & TH_ACK) {
10579 		if ((tp->snd_wl2 == th->th_ack) && (tiwin < tp->snd_wnd)) {
10580 			tp->snd_wnd = tiwin;
10581 			rack_validate_fo_sendwin_up(tp, rack);
10582 			tp->snd_wl1 = th->th_seq;
10583 			tp->snd_wl2 = th->th_ack;
10584 		}
10585 	}
10586 	if (tp->snd_wnd < ctf_outstanding(tp))
10587 		/* The peer collapsed the window */
10588 		rack_collapsed_window(rack, ctf_outstanding(tp), __LINE__);
10589 	else if (rack->rc_has_collapsed)
10590 		rack_un_collapse_window(rack, __LINE__);
10591 	if ((rack->r_collapse_point_valid) &&
10592 	    (SEQ_GT(th->th_ack, rack->r_ctl.high_collapse_point)))
10593 		rack->r_collapse_point_valid = 0;
10594 	/* Was persist timer active and now we have window space? */
10595 	if ((rack->rc_in_persist != 0) &&
10596 	    (tp->snd_wnd >= min((rack->r_ctl.rc_high_rwnd/2),
10597 				rack->r_ctl.rc_pace_min_segs))) {
10598 		rack_exit_persist(tp, rack, rack->r_ctl.rc_rcvtime);
10599 		tp->snd_nxt = tp->snd_max;
10600 		/* Make sure we output to start the timer */
10601 		rack->r_wanted_output = 1;
10602 	}
10603 	/* Do we enter persists? */
10604 	if ((rack->rc_in_persist == 0) &&
10605 	    (tp->snd_wnd < min((rack->r_ctl.rc_high_rwnd/2), rack->r_ctl.rc_pace_min_segs)) &&
10606 	    TCPS_HAVEESTABLISHED(tp->t_state) &&
10607 	    ((tp->snd_max == tp->snd_una) || rack->rc_has_collapsed) &&
10608 	    sbavail(&tp->t_inpcb->inp_socket->so_snd) &&
10609 	    (sbavail(&tp->t_inpcb->inp_socket->so_snd) > tp->snd_wnd)) {
10610 		/*
10611 		 * Here the rwnd is less than
10612 		 * the pacing size, we are established,
10613 		 * nothing is outstanding, and there is
10614 		 * data to send. Enter persists.
10615 		 */
10616 		rack_enter_persist(tp, rack, rack->r_ctl.rc_rcvtime);
10617 	}
10618 	if (tp->t_flags2 & TF2_DROP_AF_DATA) {
10619 		m_freem(m);
10620 		return (0);
10621 	}
10622 	/*
10623 	 * don't process the URG bit, ignore them drag
10624 	 * along the up.
10625 	 */
10626 	tp->rcv_up = tp->rcv_nxt;
10627 	INP_WLOCK_ASSERT(tp->t_inpcb);
10628 
10629 	/*
10630 	 * Process the segment text, merging it into the TCP sequencing
10631 	 * queue, and arranging for acknowledgment of receipt if necessary.
10632 	 * This process logically involves adjusting tp->rcv_wnd as data is
10633 	 * presented to the user (this happens in tcp_usrreq.c, case
10634 	 * PRU_RCVD).  If a FIN has already been received on this connection
10635 	 * then we just ignore the text.
10636 	 */
10637 	tfo_syn = ((tp->t_state == TCPS_SYN_RECEIVED) &&
10638 		   IS_FASTOPEN(tp->t_flags));
10639 	if ((tlen || (thflags & TH_FIN) || (tfo_syn && tlen > 0)) &&
10640 	    TCPS_HAVERCVDFIN(tp->t_state) == 0) {
10641 		tcp_seq save_start = th->th_seq;
10642 		tcp_seq save_rnxt  = tp->rcv_nxt;
10643 		int     save_tlen  = tlen;
10644 
10645 		m_adj(m, drop_hdrlen);	/* delayed header drop */
10646 		/*
10647 		 * Insert segment which includes th into TCP reassembly
10648 		 * queue with control block tp.  Set thflags to whether
10649 		 * reassembly now includes a segment with FIN.  This handles
10650 		 * the common case inline (segment is the next to be
10651 		 * received on an established connection, and the queue is
10652 		 * empty), avoiding linkage into and removal from the queue
10653 		 * and repetition of various conversions. Set DELACK for
10654 		 * segments received in order, but ack immediately when
10655 		 * segments are out of order (so fast retransmit can work).
10656 		 */
10657 		if (th->th_seq == tp->rcv_nxt &&
10658 		    SEGQ_EMPTY(tp) &&
10659 		    (TCPS_HAVEESTABLISHED(tp->t_state) ||
10660 		    tfo_syn)) {
10661 #ifdef NETFLIX_SB_LIMITS
10662 			u_int mcnt, appended;
10663 
10664 			if (so->so_rcv.sb_shlim) {
10665 				mcnt = m_memcnt(m);
10666 				appended = 0;
10667 				if (counter_fo_get(so->so_rcv.sb_shlim, mcnt,
10668 				    CFO_NOSLEEP, NULL) == false) {
10669 					counter_u64_add(tcp_sb_shlim_fails, 1);
10670 					m_freem(m);
10671 					return (0);
10672 				}
10673 			}
10674 #endif
10675 			rack_handle_delayed_ack(tp, rack, tlen, tfo_syn);
10676 			tp->rcv_nxt += tlen;
10677 			if (tlen &&
10678 			    ((tp->t_flags2 & TF2_FBYTES_COMPLETE) == 0) &&
10679 			    (tp->t_fbyte_in == 0)) {
10680 				tp->t_fbyte_in = ticks;
10681 				if (tp->t_fbyte_in == 0)
10682 					tp->t_fbyte_in = 1;
10683 				if (tp->t_fbyte_out && tp->t_fbyte_in)
10684 					tp->t_flags2 |= TF2_FBYTES_COMPLETE;
10685 			}
10686 			thflags = tcp_get_flags(th) & TH_FIN;
10687 			KMOD_TCPSTAT_ADD(tcps_rcvpack, nsegs);
10688 			KMOD_TCPSTAT_ADD(tcps_rcvbyte, tlen);
10689 			SOCKBUF_LOCK(&so->so_rcv);
10690 			if (so->so_rcv.sb_state & SBS_CANTRCVMORE) {
10691 				m_freem(m);
10692 			} else
10693 #ifdef NETFLIX_SB_LIMITS
10694 				appended =
10695 #endif
10696 					sbappendstream_locked(&so->so_rcv, m, 0);
10697 
10698 			rack_log_wakeup(tp,rack, &so->so_rcv, tlen, 1);
10699 			/* NB: sorwakeup_locked() does an implicit unlock. */
10700 			sorwakeup_locked(so);
10701 #ifdef NETFLIX_SB_LIMITS
10702 			if (so->so_rcv.sb_shlim && appended != mcnt)
10703 				counter_fo_release(so->so_rcv.sb_shlim,
10704 				    mcnt - appended);
10705 #endif
10706 		} else {
10707 			/*
10708 			 * XXX: Due to the header drop above "th" is
10709 			 * theoretically invalid by now.  Fortunately
10710 			 * m_adj() doesn't actually frees any mbufs when
10711 			 * trimming from the head.
10712 			 */
10713 			tcp_seq temp = save_start;
10714 
10715 			thflags = tcp_reass(tp, th, &temp, &tlen, m);
10716 			tp->t_flags |= TF_ACKNOW;
10717 			if (tp->t_flags & TF_WAKESOR) {
10718 				tp->t_flags &= ~TF_WAKESOR;
10719 				/* NB: sorwakeup_locked() does an implicit unlock. */
10720 				sorwakeup_locked(so);
10721 			}
10722 		}
10723 		if ((tp->t_flags & TF_SACK_PERMIT) &&
10724 		    (save_tlen > 0) &&
10725 		    TCPS_HAVEESTABLISHED(tp->t_state)) {
10726 			if ((tlen == 0) && (SEQ_LT(save_start, save_rnxt))) {
10727 				/*
10728 				 * DSACK actually handled in the fastpath
10729 				 * above.
10730 				 */
10731 				RACK_OPTS_INC(tcp_sack_path_1);
10732 				tcp_update_sack_list(tp, save_start,
10733 				    save_start + save_tlen);
10734 			} else if ((tlen > 0) && SEQ_GT(tp->rcv_nxt, save_rnxt)) {
10735 				if ((tp->rcv_numsacks >= 1) &&
10736 				    (tp->sackblks[0].end == save_start)) {
10737 					/*
10738 					 * Partial overlap, recorded at todrop
10739 					 * above.
10740 					 */
10741 					RACK_OPTS_INC(tcp_sack_path_2a);
10742 					tcp_update_sack_list(tp,
10743 					    tp->sackblks[0].start,
10744 					    tp->sackblks[0].end);
10745 				} else {
10746 					RACK_OPTS_INC(tcp_sack_path_2b);
10747 					tcp_update_dsack_list(tp, save_start,
10748 					    save_start + save_tlen);
10749 				}
10750 			} else if (tlen >= save_tlen) {
10751 				/* Update of sackblks. */
10752 				RACK_OPTS_INC(tcp_sack_path_3);
10753 				tcp_update_dsack_list(tp, save_start,
10754 				    save_start + save_tlen);
10755 			} else if (tlen > 0) {
10756 				RACK_OPTS_INC(tcp_sack_path_4);
10757 				tcp_update_dsack_list(tp, save_start,
10758 				    save_start + tlen);
10759 			}
10760 		}
10761 	} else {
10762 		m_freem(m);
10763 		thflags &= ~TH_FIN;
10764 	}
10765 
10766 	/*
10767 	 * If FIN is received ACK the FIN and let the user know that the
10768 	 * connection is closing.
10769 	 */
10770 	if (thflags & TH_FIN) {
10771 		if (TCPS_HAVERCVDFIN(tp->t_state) == 0) {
10772 			/* The socket upcall is handled by socantrcvmore. */
10773 			socantrcvmore(so);
10774 			/*
10775 			 * If connection is half-synchronized (ie NEEDSYN
10776 			 * flag on) then delay ACK, so it may be piggybacked
10777 			 * when SYN is sent. Otherwise, since we received a
10778 			 * FIN then no more input can be expected, send ACK
10779 			 * now.
10780 			 */
10781 			if (tp->t_flags & TF_NEEDSYN) {
10782 				rack_timer_cancel(tp, rack,
10783 				    rack->r_ctl.rc_rcvtime, __LINE__);
10784 				tp->t_flags |= TF_DELACK;
10785 			} else {
10786 				tp->t_flags |= TF_ACKNOW;
10787 			}
10788 			tp->rcv_nxt++;
10789 		}
10790 		switch (tp->t_state) {
10791 			/*
10792 			 * In SYN_RECEIVED and ESTABLISHED STATES enter the
10793 			 * CLOSE_WAIT state.
10794 			 */
10795 		case TCPS_SYN_RECEIVED:
10796 			tp->t_starttime = ticks;
10797 			/* FALLTHROUGH */
10798 		case TCPS_ESTABLISHED:
10799 			rack_timer_cancel(tp, rack,
10800 			    rack->r_ctl.rc_rcvtime, __LINE__);
10801 			tcp_state_change(tp, TCPS_CLOSE_WAIT);
10802 			break;
10803 
10804 			/*
10805 			 * If still in FIN_WAIT_1 STATE FIN has not been
10806 			 * acked so enter the CLOSING state.
10807 			 */
10808 		case TCPS_FIN_WAIT_1:
10809 			rack_timer_cancel(tp, rack,
10810 			    rack->r_ctl.rc_rcvtime, __LINE__);
10811 			tcp_state_change(tp, TCPS_CLOSING);
10812 			break;
10813 
10814 			/*
10815 			 * In FIN_WAIT_2 state enter the TIME_WAIT state,
10816 			 * starting the time-wait timer, turning off the
10817 			 * other standard timers.
10818 			 */
10819 		case TCPS_FIN_WAIT_2:
10820 			rack_timer_cancel(tp, rack,
10821 			    rack->r_ctl.rc_rcvtime, __LINE__);
10822 			tcp_twstart(tp);
10823 			return (1);
10824 		}
10825 	}
10826 	/*
10827 	 * Return any desired output.
10828 	 */
10829 	if ((tp->t_flags & TF_ACKNOW) ||
10830 	    (sbavail(&so->so_snd) > (tp->snd_max - tp->snd_una))) {
10831 		rack->r_wanted_output = 1;
10832 	}
10833 	INP_WLOCK_ASSERT(tp->t_inpcb);
10834 	return (0);
10835 }
10836 
10837 /*
10838  * Here nothing is really faster, its just that we
10839  * have broken out the fast-data path also just like
10840  * the fast-ack.
10841  */
10842 static int
10843 rack_do_fastnewdata(struct mbuf *m, struct tcphdr *th, struct socket *so,
10844     struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen,
10845     uint32_t tiwin, int32_t nxt_pkt, uint8_t iptos)
10846 {
10847 	int32_t nsegs;
10848 	int32_t newsize = 0;	/* automatic sockbuf scaling */
10849 	struct tcp_rack *rack;
10850 #ifdef NETFLIX_SB_LIMITS
10851 	u_int mcnt, appended;
10852 #endif
10853 #ifdef TCPDEBUG
10854 	/*
10855 	 * The size of tcp_saveipgen must be the size of the max ip header,
10856 	 * now IPv6.
10857 	 */
10858 	u_char tcp_saveipgen[IP6_HDR_LEN];
10859 	struct tcphdr tcp_savetcp;
10860 	short ostate = 0;
10861 
10862 #endif
10863 	/*
10864 	 * If last ACK falls within this segment's sequence numbers, record
10865 	 * the timestamp. NOTE that the test is modified according to the
10866 	 * latest proposal of the tcplw@cray.com list (Braden 1993/04/26).
10867 	 */
10868 	if (__predict_false(th->th_seq != tp->rcv_nxt)) {
10869 		return (0);
10870 	}
10871 	if (__predict_false(tp->snd_nxt != tp->snd_max)) {
10872 		return (0);
10873 	}
10874 	if (tiwin && tiwin != tp->snd_wnd) {
10875 		return (0);
10876 	}
10877 	if (__predict_false((tp->t_flags & (TF_NEEDSYN | TF_NEEDFIN)))) {
10878 		return (0);
10879 	}
10880 	if (__predict_false((to->to_flags & TOF_TS) &&
10881 	    (TSTMP_LT(to->to_tsval, tp->ts_recent)))) {
10882 		return (0);
10883 	}
10884 	if (__predict_false((th->th_ack != tp->snd_una))) {
10885 		return (0);
10886 	}
10887 	if (__predict_false(tlen > sbspace(&so->so_rcv))) {
10888 		return (0);
10889 	}
10890 	if ((to->to_flags & TOF_TS) != 0 &&
10891 	    SEQ_LEQ(th->th_seq, tp->last_ack_sent)) {
10892 		tp->ts_recent_age = tcp_ts_getticks();
10893 		tp->ts_recent = to->to_tsval;
10894 	}
10895 	rack = (struct tcp_rack *)tp->t_fb_ptr;
10896 	/*
10897 	 * This is a pure, in-sequence data packet with nothing on the
10898 	 * reassembly queue and we have enough buffer space to take it.
10899 	 */
10900 	nsegs = max(1, m->m_pkthdr.lro_nsegs);
10901 
10902 #ifdef NETFLIX_SB_LIMITS
10903 	if (so->so_rcv.sb_shlim) {
10904 		mcnt = m_memcnt(m);
10905 		appended = 0;
10906 		if (counter_fo_get(so->so_rcv.sb_shlim, mcnt,
10907 		    CFO_NOSLEEP, NULL) == false) {
10908 			counter_u64_add(tcp_sb_shlim_fails, 1);
10909 			m_freem(m);
10910 			return (1);
10911 		}
10912 	}
10913 #endif
10914 	/* Clean receiver SACK report if present */
10915 	if (tp->rcv_numsacks)
10916 		tcp_clean_sackreport(tp);
10917 	KMOD_TCPSTAT_INC(tcps_preddat);
10918 	tp->rcv_nxt += tlen;
10919 	if (tlen &&
10920 	    ((tp->t_flags2 & TF2_FBYTES_COMPLETE) == 0) &&
10921 	    (tp->t_fbyte_in == 0)) {
10922 		tp->t_fbyte_in = ticks;
10923 		if (tp->t_fbyte_in == 0)
10924 			tp->t_fbyte_in = 1;
10925 		if (tp->t_fbyte_out && tp->t_fbyte_in)
10926 			tp->t_flags2 |= TF2_FBYTES_COMPLETE;
10927 	}
10928 	/*
10929 	 * Pull snd_wl1 up to prevent seq wrap relative to th_seq.
10930 	 */
10931 	tp->snd_wl1 = th->th_seq;
10932 	/*
10933 	 * Pull rcv_up up to prevent seq wrap relative to rcv_nxt.
10934 	 */
10935 	tp->rcv_up = tp->rcv_nxt;
10936 	KMOD_TCPSTAT_ADD(tcps_rcvpack, nsegs);
10937 	KMOD_TCPSTAT_ADD(tcps_rcvbyte, tlen);
10938 #ifdef TCPDEBUG
10939 	if (so->so_options & SO_DEBUG)
10940 		tcp_trace(TA_INPUT, ostate, tp,
10941 		    (void *)tcp_saveipgen, &tcp_savetcp, 0);
10942 #endif
10943 	newsize = tcp_autorcvbuf(m, th, so, tp, tlen);
10944 
10945 	/* Add data to socket buffer. */
10946 	SOCKBUF_LOCK(&so->so_rcv);
10947 	if (so->so_rcv.sb_state & SBS_CANTRCVMORE) {
10948 		m_freem(m);
10949 	} else {
10950 		/*
10951 		 * Set new socket buffer size. Give up when limit is
10952 		 * reached.
10953 		 */
10954 		if (newsize)
10955 			if (!sbreserve_locked(so, SO_RCV, newsize, NULL))
10956 				so->so_rcv.sb_flags &= ~SB_AUTOSIZE;
10957 		m_adj(m, drop_hdrlen);	/* delayed header drop */
10958 #ifdef NETFLIX_SB_LIMITS
10959 		appended =
10960 #endif
10961 			sbappendstream_locked(&so->so_rcv, m, 0);
10962 		ctf_calc_rwin(so, tp);
10963 	}
10964 	rack_log_wakeup(tp,rack, &so->so_rcv, tlen, 1);
10965 	/* NB: sorwakeup_locked() does an implicit unlock. */
10966 	sorwakeup_locked(so);
10967 #ifdef NETFLIX_SB_LIMITS
10968 	if (so->so_rcv.sb_shlim && mcnt != appended)
10969 		counter_fo_release(so->so_rcv.sb_shlim, mcnt - appended);
10970 #endif
10971 	rack_handle_delayed_ack(tp, rack, tlen, 0);
10972 	if (tp->snd_una == tp->snd_max)
10973 		sack_filter_clear(&rack->r_ctl.rack_sf, tp->snd_una);
10974 	return (1);
10975 }
10976 
10977 /*
10978  * This subfunction is used to try to highly optimize the
10979  * fast path. We again allow window updates that are
10980  * in sequence to remain in the fast-path. We also add
10981  * in the __predict's to attempt to help the compiler.
10982  * Note that if we return a 0, then we can *not* process
10983  * it and the caller should push the packet into the
10984  * slow-path.
10985  */
10986 static int
10987 rack_fastack(struct mbuf *m, struct tcphdr *th, struct socket *so,
10988     struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen,
10989     uint32_t tiwin, int32_t nxt_pkt, uint32_t cts)
10990 {
10991 	int32_t acked;
10992 	int32_t nsegs;
10993 #ifdef TCPDEBUG
10994 	/*
10995 	 * The size of tcp_saveipgen must be the size of the max ip header,
10996 	 * now IPv6.
10997 	 */
10998 	u_char tcp_saveipgen[IP6_HDR_LEN];
10999 	struct tcphdr tcp_savetcp;
11000 	short ostate = 0;
11001 #endif
11002 	int32_t under_pacing = 0;
11003 	struct tcp_rack *rack;
11004 
11005 	if (__predict_false(SEQ_LEQ(th->th_ack, tp->snd_una))) {
11006 		/* Old ack, behind (or duplicate to) the last one rcv'd */
11007 		return (0);
11008 	}
11009 	if (__predict_false(SEQ_GT(th->th_ack, tp->snd_max))) {
11010 		/* Above what we have sent? */
11011 		return (0);
11012 	}
11013 	if (__predict_false(tp->snd_nxt != tp->snd_max)) {
11014 		/* We are retransmitting */
11015 		return (0);
11016 	}
11017 	if (__predict_false(tiwin == 0)) {
11018 		/* zero window */
11019 		return (0);
11020 	}
11021 	if (__predict_false(tp->t_flags & (TF_NEEDSYN | TF_NEEDFIN))) {
11022 		/* We need a SYN or a FIN, unlikely.. */
11023 		return (0);
11024 	}
11025 	if ((to->to_flags & TOF_TS) && __predict_false(TSTMP_LT(to->to_tsval, tp->ts_recent))) {
11026 		/* Timestamp is behind .. old ack with seq wrap? */
11027 		return (0);
11028 	}
11029 	if (__predict_false(IN_RECOVERY(tp->t_flags))) {
11030 		/* Still recovering */
11031 		return (0);
11032 	}
11033 	rack = (struct tcp_rack *)tp->t_fb_ptr;
11034 	if (rack->r_ctl.rc_sacked) {
11035 		/* We have sack holes on our scoreboard */
11036 		return (0);
11037 	}
11038 	/* Ok if we reach here, we can process a fast-ack */
11039 	if (rack->gp_ready &&
11040 	    (rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT)) {
11041 		under_pacing = 1;
11042 	}
11043 	nsegs = max(1, m->m_pkthdr.lro_nsegs);
11044 	rack_log_ack(tp, to, th, 0, 0);
11045 	/* Did the window get updated? */
11046 	if (tiwin != tp->snd_wnd) {
11047 		tp->snd_wnd = tiwin;
11048 		rack_validate_fo_sendwin_up(tp, rack);
11049 		tp->snd_wl1 = th->th_seq;
11050 		if (tp->snd_wnd > tp->max_sndwnd)
11051 			tp->max_sndwnd = tp->snd_wnd;
11052 	}
11053 	/* Do we exit persists? */
11054 	if ((rack->rc_in_persist != 0) &&
11055 	    (tp->snd_wnd >= min((rack->r_ctl.rc_high_rwnd/2),
11056 			       rack->r_ctl.rc_pace_min_segs))) {
11057 		rack_exit_persist(tp, rack, cts);
11058 	}
11059 	/* Do we enter persists? */
11060 	if ((rack->rc_in_persist == 0) &&
11061 	    (tp->snd_wnd < min((rack->r_ctl.rc_high_rwnd/2), rack->r_ctl.rc_pace_min_segs)) &&
11062 	    TCPS_HAVEESTABLISHED(tp->t_state) &&
11063 	    ((tp->snd_max == tp->snd_una) || rack->rc_has_collapsed) &&
11064 	    sbavail(&tp->t_inpcb->inp_socket->so_snd) &&
11065 	    (sbavail(&tp->t_inpcb->inp_socket->so_snd) > tp->snd_wnd)) {
11066 		/*
11067 		 * Here the rwnd is less than
11068 		 * the pacing size, we are established,
11069 		 * nothing is outstanding, and there is
11070 		 * data to send. Enter persists.
11071 		 */
11072 		rack_enter_persist(tp, rack, rack->r_ctl.rc_rcvtime);
11073 	}
11074 	/*
11075 	 * If last ACK falls within this segment's sequence numbers, record
11076 	 * the timestamp. NOTE that the test is modified according to the
11077 	 * latest proposal of the tcplw@cray.com list (Braden 1993/04/26).
11078 	 */
11079 	if ((to->to_flags & TOF_TS) != 0 &&
11080 	    SEQ_LEQ(th->th_seq, tp->last_ack_sent)) {
11081 		tp->ts_recent_age = tcp_ts_getticks();
11082 		tp->ts_recent = to->to_tsval;
11083 	}
11084 	/*
11085 	 * This is a pure ack for outstanding data.
11086 	 */
11087 	KMOD_TCPSTAT_INC(tcps_predack);
11088 
11089 	/*
11090 	 * "bad retransmit" recovery.
11091 	 */
11092 	if ((tp->t_flags & TF_PREVVALID) &&
11093 	    ((tp->t_flags & TF_RCVD_TSTMP) == 0)) {
11094 		tp->t_flags &= ~TF_PREVVALID;
11095 		if (tp->t_rxtshift == 1 &&
11096 		    (int)(ticks - tp->t_badrxtwin) < 0)
11097 			rack_cong_signal(tp, CC_RTO_ERR, th->th_ack, __LINE__);
11098 	}
11099 	/*
11100 	 * Recalculate the transmit timer / rtt.
11101 	 *
11102 	 * Some boxes send broken timestamp replies during the SYN+ACK
11103 	 * phase, ignore timestamps of 0 or we could calculate a huge RTT
11104 	 * and blow up the retransmit timer.
11105 	 */
11106 	acked = BYTES_THIS_ACK(tp, th);
11107 
11108 #ifdef TCP_HHOOK
11109 	/* Run HHOOK_TCP_ESTABLISHED_IN helper hooks. */
11110 	hhook_run_tcp_est_in(tp, th, to);
11111 #endif
11112 	KMOD_TCPSTAT_ADD(tcps_rcvackpack, nsegs);
11113 	KMOD_TCPSTAT_ADD(tcps_rcvackbyte, acked);
11114 	if (acked) {
11115 		struct mbuf *mfree;
11116 
11117 		rack_ack_received(tp, rack, th->th_ack, nsegs, CC_ACK, 0);
11118 		SOCKBUF_LOCK(&so->so_snd);
11119 		mfree = sbcut_locked(&so->so_snd, acked);
11120 		tp->snd_una = th->th_ack;
11121 		/* Note we want to hold the sb lock through the sendmap adjust */
11122 		rack_adjust_sendmap(rack, &so->so_snd, tp->snd_una);
11123 		/* Wake up the socket if we have room to write more */
11124 		rack_log_wakeup(tp,rack, &so->so_snd, acked, 2);
11125 		sowwakeup_locked(so);
11126 		m_freem(mfree);
11127 		tp->t_rxtshift = 0;
11128 		RACK_TCPT_RANGESET(tp->t_rxtcur, RACK_REXMTVAL(tp),
11129 			      rack_rto_min, rack_rto_max, rack->r_ctl.timer_slop);
11130 		rack->rc_tlp_in_progress = 0;
11131 		rack->r_ctl.rc_tlp_cnt_out = 0;
11132 		/*
11133 		 * If it is the RXT timer we want to
11134 		 * stop it, so we can restart a TLP.
11135 		 */
11136 		if (rack->r_ctl.rc_hpts_flags & PACE_TMR_RXT)
11137 			rack_timer_cancel(tp, rack, rack->r_ctl.rc_rcvtime, __LINE__);
11138 #ifdef NETFLIX_HTTP_LOGGING
11139 		tcp_http_check_for_comp(rack->rc_tp, th->th_ack);
11140 #endif
11141 	}
11142 	/*
11143 	 * Let the congestion control algorithm update congestion control
11144 	 * related information. This typically means increasing the
11145 	 * congestion window.
11146 	 */
11147 	if (tp->snd_wnd < ctf_outstanding(tp)) {
11148 		/* The peer collapsed the window */
11149 		rack_collapsed_window(rack, ctf_outstanding(tp), __LINE__);
11150 	} else if (rack->rc_has_collapsed)
11151 		rack_un_collapse_window(rack, __LINE__);
11152 	if ((rack->r_collapse_point_valid) &&
11153 	    (SEQ_GT(tp->snd_una, rack->r_ctl.high_collapse_point)))
11154 		rack->r_collapse_point_valid = 0;
11155 	/*
11156 	 * Pull snd_wl2 up to prevent seq wrap relative to th_ack.
11157 	 */
11158 	tp->snd_wl2 = th->th_ack;
11159 	tp->t_dupacks = 0;
11160 	m_freem(m);
11161 	/* ND6_HINT(tp);	 *//* Some progress has been made. */
11162 
11163 	/*
11164 	 * If all outstanding data are acked, stop retransmit timer,
11165 	 * otherwise restart timer using current (possibly backed-off)
11166 	 * value. If process is waiting for space, wakeup/selwakeup/signal.
11167 	 * If data are ready to send, let tcp_output decide between more
11168 	 * output or persist.
11169 	 */
11170 #ifdef TCPDEBUG
11171 	if (so->so_options & SO_DEBUG)
11172 		tcp_trace(TA_INPUT, ostate, tp,
11173 		    (void *)tcp_saveipgen,
11174 		    &tcp_savetcp, 0);
11175 #endif
11176 	if (under_pacing &&
11177 	    (rack->use_fixed_rate == 0) &&
11178 	    (rack->in_probe_rtt == 0) &&
11179 	    rack->rc_gp_dyn_mul &&
11180 	    rack->rc_always_pace) {
11181 		/* Check if we are dragging bottom */
11182 		rack_check_bottom_drag(tp, rack, so, acked);
11183 	}
11184 	if (tp->snd_una == tp->snd_max) {
11185 		tp->t_flags &= ~TF_PREVVALID;
11186 		rack->r_ctl.retran_during_recovery = 0;
11187 		rack->r_ctl.dsack_byte_cnt = 0;
11188 		rack->r_ctl.rc_went_idle_time = tcp_get_usecs(NULL);
11189 		if (rack->r_ctl.rc_went_idle_time == 0)
11190 			rack->r_ctl.rc_went_idle_time = 1;
11191 		rack_log_progress_event(rack, tp, 0, PROGRESS_CLEAR, __LINE__);
11192 		if (sbavail(&tp->t_inpcb->inp_socket->so_snd) == 0)
11193 			tp->t_acktime = 0;
11194 		rack_timer_cancel(tp, rack, rack->r_ctl.rc_rcvtime, __LINE__);
11195 	}
11196 	if (acked && rack->r_fast_output)
11197 		rack_gain_for_fastoutput(rack, tp, so, (uint32_t)acked);
11198 	if (sbavail(&so->so_snd)) {
11199 		rack->r_wanted_output = 1;
11200 	}
11201 	return (1);
11202 }
11203 
11204 /*
11205  * Return value of 1, the TCB is unlocked and most
11206  * likely gone, return value of 0, the TCP is still
11207  * locked.
11208  */
11209 static int
11210 rack_do_syn_sent(struct mbuf *m, struct tcphdr *th, struct socket *so,
11211     struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen,
11212     uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos)
11213 {
11214 	int32_t ret_val = 0;
11215 	int32_t todrop;
11216 	int32_t ourfinisacked = 0;
11217 	struct tcp_rack *rack;
11218 
11219 	ctf_calc_rwin(so, tp);
11220 	/*
11221 	 * If the state is SYN_SENT: if seg contains an ACK, but not for our
11222 	 * SYN, drop the input. if seg contains a RST, then drop the
11223 	 * connection. if seg does not contain SYN, then drop it. Otherwise
11224 	 * this is an acceptable SYN segment initialize tp->rcv_nxt and
11225 	 * tp->irs if seg contains ack then advance tp->snd_una if seg
11226 	 * contains an ECE and ECN support is enabled, the stream is ECN
11227 	 * capable. if SYN has been acked change to ESTABLISHED else
11228 	 * SYN_RCVD state arrange for segment to be acked (eventually)
11229 	 * continue processing rest of data/controls.
11230 	 */
11231 	if ((thflags & TH_ACK) &&
11232 	    (SEQ_LEQ(th->th_ack, tp->iss) ||
11233 	    SEQ_GT(th->th_ack, tp->snd_max))) {
11234 		tcp_log_end_status(tp, TCP_EI_STATUS_RST_IN_FRONT);
11235 		ctf_do_dropwithreset(m, tp, th, BANDLIM_RST_OPENPORT, tlen);
11236 		return (1);
11237 	}
11238 	if ((thflags & (TH_ACK | TH_RST)) == (TH_ACK | TH_RST)) {
11239 		TCP_PROBE5(connect__refused, NULL, tp,
11240 		    mtod(m, const char *), tp, th);
11241 		tp = tcp_drop(tp, ECONNREFUSED);
11242 		ctf_do_drop(m, tp);
11243 		return (1);
11244 	}
11245 	if (thflags & TH_RST) {
11246 		ctf_do_drop(m, tp);
11247 		return (1);
11248 	}
11249 	if (!(thflags & TH_SYN)) {
11250 		ctf_do_drop(m, tp);
11251 		return (1);
11252 	}
11253 	tp->irs = th->th_seq;
11254 	tcp_rcvseqinit(tp);
11255 	rack = (struct tcp_rack *)tp->t_fb_ptr;
11256 	if (thflags & TH_ACK) {
11257 		int tfo_partial = 0;
11258 
11259 		KMOD_TCPSTAT_INC(tcps_connects);
11260 		soisconnected(so);
11261 #ifdef MAC
11262 		mac_socketpeer_set_from_mbuf(m, so);
11263 #endif
11264 		/* Do window scaling on this connection? */
11265 		if ((tp->t_flags & (TF_RCVD_SCALE | TF_REQ_SCALE)) ==
11266 		    (TF_RCVD_SCALE | TF_REQ_SCALE)) {
11267 			tp->rcv_scale = tp->request_r_scale;
11268 		}
11269 		tp->rcv_adv += min(tp->rcv_wnd,
11270 		    TCP_MAXWIN << tp->rcv_scale);
11271 		/*
11272 		 * If not all the data that was sent in the TFO SYN
11273 		 * has been acked, resend the remainder right away.
11274 		 */
11275 		if (IS_FASTOPEN(tp->t_flags) &&
11276 		    (tp->snd_una != tp->snd_max)) {
11277 			tp->snd_nxt = th->th_ack;
11278 			tfo_partial = 1;
11279 		}
11280 		/*
11281 		 * If there's data, delay ACK; if there's also a FIN ACKNOW
11282 		 * will be turned on later.
11283 		 */
11284 		if (DELAY_ACK(tp, tlen) && tlen != 0 && !tfo_partial) {
11285 			rack_timer_cancel(tp, rack,
11286 					  rack->r_ctl.rc_rcvtime, __LINE__);
11287 			tp->t_flags |= TF_DELACK;
11288 		} else {
11289 			rack->r_wanted_output = 1;
11290 			tp->t_flags |= TF_ACKNOW;
11291 			rack->rc_dack_toggle = 0;
11292 		}
11293 
11294 		tcp_ecn_input_syn_sent(tp, thflags, iptos);
11295 
11296 		if (SEQ_GT(th->th_ack, tp->snd_una)) {
11297 			/*
11298 			 * We advance snd_una for the
11299 			 * fast open case. If th_ack is
11300 			 * acknowledging data beyond
11301 			 * snd_una we can't just call
11302 			 * ack-processing since the
11303 			 * data stream in our send-map
11304 			 * will start at snd_una + 1 (one
11305 			 * beyond the SYN). If its just
11306 			 * equal we don't need to do that
11307 			 * and there is no send_map.
11308 			 */
11309 			tp->snd_una++;
11310 		}
11311 		/*
11312 		 * Received <SYN,ACK> in SYN_SENT[*] state. Transitions:
11313 		 * SYN_SENT  --> ESTABLISHED SYN_SENT* --> FIN_WAIT_1
11314 		 */
11315 		tp->t_starttime = ticks;
11316 		if (tp->t_flags & TF_NEEDFIN) {
11317 			tcp_state_change(tp, TCPS_FIN_WAIT_1);
11318 			tp->t_flags &= ~TF_NEEDFIN;
11319 			thflags &= ~TH_SYN;
11320 		} else {
11321 			tcp_state_change(tp, TCPS_ESTABLISHED);
11322 			TCP_PROBE5(connect__established, NULL, tp,
11323 			    mtod(m, const char *), tp, th);
11324 			rack_cc_conn_init(tp);
11325 		}
11326 	} else {
11327 		/*
11328 		 * Received initial SYN in SYN-SENT[*] state => simultaneous
11329 		 * open.  If segment contains CC option and there is a
11330 		 * cached CC, apply TAO test. If it succeeds, connection is *
11331 		 * half-synchronized. Otherwise, do 3-way handshake:
11332 		 * SYN-SENT -> SYN-RECEIVED SYN-SENT* -> SYN-RECEIVED* If
11333 		 * there was no CC option, clear cached CC value.
11334 		 */
11335 		tp->t_flags |= (TF_ACKNOW | TF_NEEDSYN | TF_SONOTCONN);
11336 		tcp_state_change(tp, TCPS_SYN_RECEIVED);
11337 	}
11338 	INP_WLOCK_ASSERT(tp->t_inpcb);
11339 	/*
11340 	 * Advance th->th_seq to correspond to first data byte. If data,
11341 	 * trim to stay within window, dropping FIN if necessary.
11342 	 */
11343 	th->th_seq++;
11344 	if (tlen > tp->rcv_wnd) {
11345 		todrop = tlen - tp->rcv_wnd;
11346 		m_adj(m, -todrop);
11347 		tlen = tp->rcv_wnd;
11348 		thflags &= ~TH_FIN;
11349 		KMOD_TCPSTAT_INC(tcps_rcvpackafterwin);
11350 		KMOD_TCPSTAT_ADD(tcps_rcvbyteafterwin, todrop);
11351 	}
11352 	tp->snd_wl1 = th->th_seq - 1;
11353 	tp->rcv_up = th->th_seq;
11354 	/*
11355 	 * Client side of transaction: already sent SYN and data. If the
11356 	 * remote host used T/TCP to validate the SYN, our data will be
11357 	 * ACK'd; if so, enter normal data segment processing in the middle
11358 	 * of step 5, ack processing. Otherwise, goto step 6.
11359 	 */
11360 	if (thflags & TH_ACK) {
11361 		/* For syn-sent we need to possibly update the rtt */
11362 		if ((to->to_flags & TOF_TS) != 0 && to->to_tsecr) {
11363 			uint32_t t, mcts;
11364 
11365 			mcts = tcp_ts_getticks();
11366 			t = (mcts - to->to_tsecr) * HPTS_USEC_IN_MSEC;
11367 			if (!tp->t_rttlow || tp->t_rttlow > t)
11368 				tp->t_rttlow = t;
11369 			rack_log_rtt_sample_calc(rack, t, (to->to_tsecr * 1000), (mcts * 1000), 4);
11370 			tcp_rack_xmit_timer(rack, t + 1, 1, t, 0, NULL, 2);
11371 			tcp_rack_xmit_timer_commit(rack, tp);
11372 		}
11373 		if (rack_process_ack(m, th, so, tp, to, tiwin, tlen, &ourfinisacked, thflags, &ret_val))
11374 			return (ret_val);
11375 		/* We may have changed to FIN_WAIT_1 above */
11376 		if (tp->t_state == TCPS_FIN_WAIT_1) {
11377 			/*
11378 			 * In FIN_WAIT_1 STATE in addition to the processing
11379 			 * for the ESTABLISHED state if our FIN is now
11380 			 * acknowledged then enter FIN_WAIT_2.
11381 			 */
11382 			if (ourfinisacked) {
11383 				/*
11384 				 * If we can't receive any more data, then
11385 				 * closing user can proceed. Starting the
11386 				 * timer is contrary to the specification,
11387 				 * but if we don't get a FIN we'll hang
11388 				 * forever.
11389 				 *
11390 				 * XXXjl: we should release the tp also, and
11391 				 * use a compressed state.
11392 				 */
11393 				if (so->so_rcv.sb_state & SBS_CANTRCVMORE) {
11394 					soisdisconnected(so);
11395 					tcp_timer_activate(tp, TT_2MSL,
11396 					    (tcp_fast_finwait2_recycle ?
11397 					    tcp_finwait2_timeout :
11398 					    TP_MAXIDLE(tp)));
11399 				}
11400 				tcp_state_change(tp, TCPS_FIN_WAIT_2);
11401 			}
11402 		}
11403 	}
11404 	return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
11405 	   tiwin, thflags, nxt_pkt));
11406 }
11407 
11408 /*
11409  * Return value of 1, the TCB is unlocked and most
11410  * likely gone, return value of 0, the TCP is still
11411  * locked.
11412  */
11413 static int
11414 rack_do_syn_recv(struct mbuf *m, struct tcphdr *th, struct socket *so,
11415     struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen,
11416     uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos)
11417 {
11418 	struct tcp_rack *rack;
11419 	int32_t ret_val = 0;
11420 	int32_t ourfinisacked = 0;
11421 
11422 	ctf_calc_rwin(so, tp);
11423 	if ((thflags & TH_ACK) &&
11424 	    (SEQ_LEQ(th->th_ack, tp->snd_una) ||
11425 	    SEQ_GT(th->th_ack, tp->snd_max))) {
11426 		tcp_log_end_status(tp, TCP_EI_STATUS_RST_IN_FRONT);
11427 		ctf_do_dropwithreset(m, tp, th, BANDLIM_RST_OPENPORT, tlen);
11428 		return (1);
11429 	}
11430 	rack = (struct tcp_rack *)tp->t_fb_ptr;
11431 	if (IS_FASTOPEN(tp->t_flags)) {
11432 		/*
11433 		 * When a TFO connection is in SYN_RECEIVED, the
11434 		 * only valid packets are the initial SYN, a
11435 		 * retransmit/copy of the initial SYN (possibly with
11436 		 * a subset of the original data), a valid ACK, a
11437 		 * FIN, or a RST.
11438 		 */
11439 		if ((thflags & (TH_SYN | TH_ACK)) == (TH_SYN | TH_ACK)) {
11440 			tcp_log_end_status(tp, TCP_EI_STATUS_RST_IN_FRONT);
11441 			ctf_do_dropwithreset(m, tp, th, BANDLIM_RST_OPENPORT, tlen);
11442 			return (1);
11443 		} else if (thflags & TH_SYN) {
11444 			/* non-initial SYN is ignored */
11445 			if ((rack->r_ctl.rc_hpts_flags & PACE_TMR_RXT) ||
11446 			    (rack->r_ctl.rc_hpts_flags & PACE_TMR_TLP) ||
11447 			    (rack->r_ctl.rc_hpts_flags & PACE_TMR_RACK)) {
11448 				ctf_do_drop(m, NULL);
11449 				return (0);
11450 			}
11451 		} else if (!(thflags & (TH_ACK | TH_FIN | TH_RST))) {
11452 			ctf_do_drop(m, NULL);
11453 			return (0);
11454 		}
11455 	}
11456 
11457 	if ((thflags & TH_RST) ||
11458 	    (tp->t_fin_is_rst && (thflags & TH_FIN)))
11459 		return (__ctf_process_rst(m, th, so, tp,
11460 					  &rack->r_ctl.challenge_ack_ts,
11461 					  &rack->r_ctl.challenge_ack_cnt));
11462 	/*
11463 	 * RFC 1323 PAWS: If we have a timestamp reply on this segment and
11464 	 * it's less than ts_recent, drop it.
11465 	 */
11466 	if ((to->to_flags & TOF_TS) != 0 && tp->ts_recent &&
11467 	    TSTMP_LT(to->to_tsval, tp->ts_recent)) {
11468 		if (ctf_ts_check(m, th, tp, tlen, thflags, &ret_val))
11469 			return (ret_val);
11470 	}
11471 	/*
11472 	 * In the SYN-RECEIVED state, validate that the packet belongs to
11473 	 * this connection before trimming the data to fit the receive
11474 	 * window.  Check the sequence number versus IRS since we know the
11475 	 * sequence numbers haven't wrapped.  This is a partial fix for the
11476 	 * "LAND" DoS attack.
11477 	 */
11478 	if (SEQ_LT(th->th_seq, tp->irs)) {
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 	if (_ctf_drop_checks(to, m, th, tp, &tlen, &thflags, &drop_hdrlen, &ret_val,
11484 			      &rack->r_ctl.challenge_ack_ts,
11485 			      &rack->r_ctl.challenge_ack_cnt)) {
11486 		return (ret_val);
11487 	}
11488 	/*
11489 	 * If last ACK falls within this segment's sequence numbers, record
11490 	 * its timestamp. NOTE: 1) That the test incorporates suggestions
11491 	 * from the latest proposal of the tcplw@cray.com list (Braden
11492 	 * 1993/04/26). 2) That updating only on newer timestamps interferes
11493 	 * with our earlier PAWS tests, so this check should be solely
11494 	 * predicated on the sequence space of this segment. 3) That we
11495 	 * modify the segment boundary check to be Last.ACK.Sent <= SEG.SEQ
11496 	 * + SEG.Len  instead of RFC1323's Last.ACK.Sent < SEG.SEQ +
11497 	 * SEG.Len, This modified check allows us to overcome RFC1323's
11498 	 * limitations as described in Stevens TCP/IP Illustrated Vol. 2
11499 	 * p.869. In such cases, we can still calculate the RTT correctly
11500 	 * when RCV.NXT == Last.ACK.Sent.
11501 	 */
11502 	if ((to->to_flags & TOF_TS) != 0 &&
11503 	    SEQ_LEQ(th->th_seq, tp->last_ack_sent) &&
11504 	    SEQ_LEQ(tp->last_ack_sent, th->th_seq + tlen +
11505 	    ((thflags & (TH_SYN | TH_FIN)) != 0))) {
11506 		tp->ts_recent_age = tcp_ts_getticks();
11507 		tp->ts_recent = to->to_tsval;
11508 	}
11509 	tp->snd_wnd = tiwin;
11510 	rack_validate_fo_sendwin_up(tp, rack);
11511 	/*
11512 	 * If the ACK bit is off:  if in SYN-RECEIVED state or SENDSYN flag
11513 	 * is on (half-synchronized state), then queue data for later
11514 	 * processing; else drop segment and return.
11515 	 */
11516 	if ((thflags & TH_ACK) == 0) {
11517 		if (IS_FASTOPEN(tp->t_flags)) {
11518 			rack_cc_conn_init(tp);
11519 		}
11520 		return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
11521 		    tiwin, thflags, nxt_pkt));
11522 	}
11523 	KMOD_TCPSTAT_INC(tcps_connects);
11524 	if (tp->t_flags & TF_SONOTCONN) {
11525 		tp->t_flags &= ~TF_SONOTCONN;
11526 		soisconnected(so);
11527 	}
11528 	/* Do window scaling? */
11529 	if ((tp->t_flags & (TF_RCVD_SCALE | TF_REQ_SCALE)) ==
11530 	    (TF_RCVD_SCALE | TF_REQ_SCALE)) {
11531 		tp->rcv_scale = tp->request_r_scale;
11532 	}
11533 	/*
11534 	 * Make transitions: SYN-RECEIVED  -> ESTABLISHED SYN-RECEIVED* ->
11535 	 * FIN-WAIT-1
11536 	 */
11537 	tp->t_starttime = ticks;
11538 	if (IS_FASTOPEN(tp->t_flags) && tp->t_tfo_pending) {
11539 		tcp_fastopen_decrement_counter(tp->t_tfo_pending);
11540 		tp->t_tfo_pending = NULL;
11541 	}
11542 	if (tp->t_flags & TF_NEEDFIN) {
11543 		tcp_state_change(tp, TCPS_FIN_WAIT_1);
11544 		tp->t_flags &= ~TF_NEEDFIN;
11545 	} else {
11546 		tcp_state_change(tp, TCPS_ESTABLISHED);
11547 		TCP_PROBE5(accept__established, NULL, tp,
11548 		    mtod(m, const char *), tp, th);
11549 		/*
11550 		 * TFO connections call cc_conn_init() during SYN
11551 		 * processing.  Calling it again here for such connections
11552 		 * is not harmless as it would undo the snd_cwnd reduction
11553 		 * that occurs when a TFO SYN|ACK is retransmitted.
11554 		 */
11555 		if (!IS_FASTOPEN(tp->t_flags))
11556 			rack_cc_conn_init(tp);
11557 	}
11558 	/*
11559 	 * Account for the ACK of our SYN prior to
11560 	 * regular ACK processing below, except for
11561 	 * simultaneous SYN, which is handled later.
11562 	 */
11563 	if (SEQ_GT(th->th_ack, tp->snd_una) && !(tp->t_flags & TF_NEEDSYN))
11564 		tp->snd_una++;
11565 	/*
11566 	 * If segment contains data or ACK, will call tcp_reass() later; if
11567 	 * not, do so now to pass queued data to user.
11568 	 */
11569 	if (tlen == 0 && (thflags & TH_FIN) == 0) {
11570 		(void) tcp_reass(tp, (struct tcphdr *)0, NULL, 0,
11571 		    (struct mbuf *)0);
11572 		if (tp->t_flags & TF_WAKESOR) {
11573 			tp->t_flags &= ~TF_WAKESOR;
11574 			/* NB: sorwakeup_locked() does an implicit unlock. */
11575 			sorwakeup_locked(so);
11576 		}
11577 	}
11578 	tp->snd_wl1 = th->th_seq - 1;
11579 	/* For syn-recv we need to possibly update the rtt */
11580 	if ((to->to_flags & TOF_TS) != 0 && to->to_tsecr) {
11581 		uint32_t t, mcts;
11582 
11583 		mcts = tcp_ts_getticks();
11584 		t = (mcts - to->to_tsecr) * HPTS_USEC_IN_MSEC;
11585 		if (!tp->t_rttlow || tp->t_rttlow > t)
11586 			tp->t_rttlow = t;
11587 		rack_log_rtt_sample_calc(rack, t, (to->to_tsecr * 1000), (mcts * 1000), 5);
11588 		tcp_rack_xmit_timer(rack, t + 1, 1, t, 0, NULL, 2);
11589 		tcp_rack_xmit_timer_commit(rack, tp);
11590 	}
11591 	if (rack_process_ack(m, th, so, tp, to, tiwin, tlen, &ourfinisacked, thflags, &ret_val)) {
11592 		return (ret_val);
11593 	}
11594 	if (tp->t_state == TCPS_FIN_WAIT_1) {
11595 		/* We could have went to FIN_WAIT_1 (or EST) above */
11596 		/*
11597 		 * In FIN_WAIT_1 STATE in addition to the processing for the
11598 		 * ESTABLISHED state if our FIN is now acknowledged then
11599 		 * enter FIN_WAIT_2.
11600 		 */
11601 		if (ourfinisacked) {
11602 			/*
11603 			 * If we can't receive any more data, then closing
11604 			 * user can proceed. Starting the timer is contrary
11605 			 * to the specification, but if we don't get a FIN
11606 			 * we'll hang forever.
11607 			 *
11608 			 * XXXjl: we should release the tp also, and use a
11609 			 * compressed state.
11610 			 */
11611 			if (so->so_rcv.sb_state & SBS_CANTRCVMORE) {
11612 				soisdisconnected(so);
11613 				tcp_timer_activate(tp, TT_2MSL,
11614 				    (tcp_fast_finwait2_recycle ?
11615 				    tcp_finwait2_timeout :
11616 				    TP_MAXIDLE(tp)));
11617 			}
11618 			tcp_state_change(tp, TCPS_FIN_WAIT_2);
11619 		}
11620 	}
11621 	return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
11622 	    tiwin, thflags, nxt_pkt));
11623 }
11624 
11625 /*
11626  * Return value of 1, the TCB is unlocked and most
11627  * likely gone, return value of 0, the TCP is still
11628  * locked.
11629  */
11630 static int
11631 rack_do_established(struct mbuf *m, struct tcphdr *th, struct socket *so,
11632     struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen,
11633     uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos)
11634 {
11635 	int32_t ret_val = 0;
11636 	struct tcp_rack *rack;
11637 
11638 	/*
11639 	 * Header prediction: check for the two common cases of a
11640 	 * uni-directional data xfer.  If the packet has no control flags,
11641 	 * is in-sequence, the window didn't change and we're not
11642 	 * retransmitting, it's a candidate.  If the length is zero and the
11643 	 * ack moved forward, we're the sender side of the xfer.  Just free
11644 	 * the data acked & wake any higher level process that was blocked
11645 	 * waiting for space.  If the length is non-zero and the ack didn't
11646 	 * move, we're the receiver side.  If we're getting packets in-order
11647 	 * (the reassembly queue is empty), add the data toc The socket
11648 	 * buffer and note that we need a delayed ack. Make sure that the
11649 	 * hidden state-flags are also off. Since we check for
11650 	 * TCPS_ESTABLISHED first, it can only be TH_NEEDSYN.
11651 	 */
11652 	rack = (struct tcp_rack *)tp->t_fb_ptr;
11653 	if (__predict_true(((to->to_flags & TOF_SACK) == 0)) &&
11654 	    __predict_true((thflags & (TH_SYN | TH_FIN | TH_RST | TH_ACK)) == TH_ACK) &&
11655 	    __predict_true(SEGQ_EMPTY(tp)) &&
11656 	    __predict_true(th->th_seq == tp->rcv_nxt)) {
11657 		if (tlen == 0) {
11658 			if (rack_fastack(m, th, so, tp, to, drop_hdrlen, tlen,
11659 			    tiwin, nxt_pkt, rack->r_ctl.rc_rcvtime)) {
11660 				return (0);
11661 			}
11662 		} else {
11663 			if (rack_do_fastnewdata(m, th, so, tp, to, drop_hdrlen, tlen,
11664 			    tiwin, nxt_pkt, iptos)) {
11665 				return (0);
11666 			}
11667 		}
11668 	}
11669 	ctf_calc_rwin(so, tp);
11670 
11671 	if ((thflags & TH_RST) ||
11672 	    (tp->t_fin_is_rst && (thflags & TH_FIN)))
11673 		return (__ctf_process_rst(m, th, so, tp,
11674 					  &rack->r_ctl.challenge_ack_ts,
11675 					  &rack->r_ctl.challenge_ack_cnt));
11676 
11677 	/*
11678 	 * RFC5961 Section 4.2 Send challenge ACK for any SYN in
11679 	 * synchronized state.
11680 	 */
11681 	if (thflags & TH_SYN) {
11682 		ctf_challenge_ack(m, th, tp, &ret_val);
11683 		return (ret_val);
11684 	}
11685 	/*
11686 	 * RFC 1323 PAWS: If we have a timestamp reply on this segment and
11687 	 * it's less than ts_recent, drop it.
11688 	 */
11689 	if ((to->to_flags & TOF_TS) != 0 && tp->ts_recent &&
11690 	    TSTMP_LT(to->to_tsval, tp->ts_recent)) {
11691 		if (ctf_ts_check(m, th, tp, tlen, thflags, &ret_val))
11692 			return (ret_val);
11693 	}
11694 	if (_ctf_drop_checks(to, m, th, tp, &tlen, &thflags, &drop_hdrlen, &ret_val,
11695 			      &rack->r_ctl.challenge_ack_ts,
11696 			      &rack->r_ctl.challenge_ack_cnt)) {
11697 		return (ret_val);
11698 	}
11699 	/*
11700 	 * If last ACK falls within this segment's sequence numbers, record
11701 	 * its timestamp. NOTE: 1) That the test incorporates suggestions
11702 	 * from the latest proposal of the tcplw@cray.com list (Braden
11703 	 * 1993/04/26). 2) That updating only on newer timestamps interferes
11704 	 * with our earlier PAWS tests, so this check should be solely
11705 	 * predicated on the sequence space of this segment. 3) That we
11706 	 * modify the segment boundary check to be Last.ACK.Sent <= SEG.SEQ
11707 	 * + SEG.Len  instead of RFC1323's Last.ACK.Sent < SEG.SEQ +
11708 	 * SEG.Len, This modified check allows us to overcome RFC1323's
11709 	 * limitations as described in Stevens TCP/IP Illustrated Vol. 2
11710 	 * p.869. In such cases, we can still calculate the RTT correctly
11711 	 * when RCV.NXT == Last.ACK.Sent.
11712 	 */
11713 	if ((to->to_flags & TOF_TS) != 0 &&
11714 	    SEQ_LEQ(th->th_seq, tp->last_ack_sent) &&
11715 	    SEQ_LEQ(tp->last_ack_sent, th->th_seq + tlen +
11716 	    ((thflags & (TH_SYN | TH_FIN)) != 0))) {
11717 		tp->ts_recent_age = tcp_ts_getticks();
11718 		tp->ts_recent = to->to_tsval;
11719 	}
11720 	/*
11721 	 * If the ACK bit is off:  if in SYN-RECEIVED state or SENDSYN flag
11722 	 * is on (half-synchronized state), then queue data for later
11723 	 * processing; else drop segment and return.
11724 	 */
11725 	if ((thflags & TH_ACK) == 0) {
11726 		if (tp->t_flags & TF_NEEDSYN) {
11727 			return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
11728 			    tiwin, thflags, nxt_pkt));
11729 
11730 		} else if (tp->t_flags & TF_ACKNOW) {
11731 			ctf_do_dropafterack(m, tp, th, thflags, tlen, &ret_val);
11732 			((struct tcp_rack *)tp->t_fb_ptr)->r_wanted_output = 1;
11733 			return (ret_val);
11734 		} else {
11735 			ctf_do_drop(m, NULL);
11736 			return (0);
11737 		}
11738 	}
11739 	/*
11740 	 * Ack processing.
11741 	 */
11742 	if (rack_process_ack(m, th, so, tp, to, tiwin, tlen, NULL, thflags, &ret_val)) {
11743 		return (ret_val);
11744 	}
11745 	if (sbavail(&so->so_snd)) {
11746 		if (ctf_progress_timeout_check(tp, true)) {
11747 			rack_log_progress_event(rack, tp, tick, PROGRESS_DROP, __LINE__);
11748 			ctf_do_dropwithreset_conn(m, tp, th, BANDLIM_RST_OPENPORT, tlen);
11749 			return (1);
11750 		}
11751 	}
11752 	/* State changes only happen in rack_process_data() */
11753 	return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
11754 	    tiwin, thflags, nxt_pkt));
11755 }
11756 
11757 /*
11758  * Return value of 1, the TCB is unlocked and most
11759  * likely gone, return value of 0, the TCP is still
11760  * locked.
11761  */
11762 static int
11763 rack_do_close_wait(struct mbuf *m, struct tcphdr *th, struct socket *so,
11764     struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen,
11765     uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos)
11766 {
11767 	int32_t ret_val = 0;
11768 	struct tcp_rack *rack;
11769 
11770 	rack = (struct tcp_rack *)tp->t_fb_ptr;
11771 	ctf_calc_rwin(so, tp);
11772 	if ((thflags & TH_RST) ||
11773 	    (tp->t_fin_is_rst && (thflags & TH_FIN)))
11774 		return (__ctf_process_rst(m, th, so, tp,
11775 					  &rack->r_ctl.challenge_ack_ts,
11776 					  &rack->r_ctl.challenge_ack_cnt));
11777 	/*
11778 	 * RFC5961 Section 4.2 Send challenge ACK for any SYN in
11779 	 * synchronized state.
11780 	 */
11781 	if (thflags & TH_SYN) {
11782 		ctf_challenge_ack(m, th, tp, &ret_val);
11783 		return (ret_val);
11784 	}
11785 	/*
11786 	 * RFC 1323 PAWS: If we have a timestamp reply on this segment and
11787 	 * it's less than ts_recent, drop it.
11788 	 */
11789 	if ((to->to_flags & TOF_TS) != 0 && tp->ts_recent &&
11790 	    TSTMP_LT(to->to_tsval, tp->ts_recent)) {
11791 		if (ctf_ts_check(m, th, tp, tlen, thflags, &ret_val))
11792 			return (ret_val);
11793 	}
11794 	if (_ctf_drop_checks(to, m, th, tp, &tlen, &thflags, &drop_hdrlen, &ret_val,
11795 			      &rack->r_ctl.challenge_ack_ts,
11796 			      &rack->r_ctl.challenge_ack_cnt)) {
11797 		return (ret_val);
11798 	}
11799 	/*
11800 	 * If last ACK falls within this segment's sequence numbers, record
11801 	 * its timestamp. NOTE: 1) That the test incorporates suggestions
11802 	 * from the latest proposal of the tcplw@cray.com list (Braden
11803 	 * 1993/04/26). 2) That updating only on newer timestamps interferes
11804 	 * with our earlier PAWS tests, so this check should be solely
11805 	 * predicated on the sequence space of this segment. 3) That we
11806 	 * modify the segment boundary check to be Last.ACK.Sent <= SEG.SEQ
11807 	 * + SEG.Len  instead of RFC1323's Last.ACK.Sent < SEG.SEQ +
11808 	 * SEG.Len, This modified check allows us to overcome RFC1323's
11809 	 * limitations as described in Stevens TCP/IP Illustrated Vol. 2
11810 	 * p.869. In such cases, we can still calculate the RTT correctly
11811 	 * when RCV.NXT == Last.ACK.Sent.
11812 	 */
11813 	if ((to->to_flags & TOF_TS) != 0 &&
11814 	    SEQ_LEQ(th->th_seq, tp->last_ack_sent) &&
11815 	    SEQ_LEQ(tp->last_ack_sent, th->th_seq + tlen +
11816 	    ((thflags & (TH_SYN | TH_FIN)) != 0))) {
11817 		tp->ts_recent_age = tcp_ts_getticks();
11818 		tp->ts_recent = to->to_tsval;
11819 	}
11820 	/*
11821 	 * If the ACK bit is off:  if in SYN-RECEIVED state or SENDSYN flag
11822 	 * is on (half-synchronized state), then queue data for later
11823 	 * processing; else drop segment and return.
11824 	 */
11825 	if ((thflags & TH_ACK) == 0) {
11826 		if (tp->t_flags & TF_NEEDSYN) {
11827 			return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
11828 			    tiwin, thflags, nxt_pkt));
11829 
11830 		} else if (tp->t_flags & TF_ACKNOW) {
11831 			ctf_do_dropafterack(m, tp, th, thflags, tlen, &ret_val);
11832 			((struct tcp_rack *)tp->t_fb_ptr)->r_wanted_output = 1;
11833 			return (ret_val);
11834 		} else {
11835 			ctf_do_drop(m, NULL);
11836 			return (0);
11837 		}
11838 	}
11839 	/*
11840 	 * Ack processing.
11841 	 */
11842 	if (rack_process_ack(m, th, so, tp, to, tiwin, tlen, NULL, thflags, &ret_val)) {
11843 		return (ret_val);
11844 	}
11845 	if (sbavail(&so->so_snd)) {
11846 		if (ctf_progress_timeout_check(tp, true)) {
11847 			rack_log_progress_event((struct tcp_rack *)tp->t_fb_ptr,
11848 						tp, tick, PROGRESS_DROP, __LINE__);
11849 			ctf_do_dropwithreset_conn(m, tp, th, BANDLIM_RST_OPENPORT, tlen);
11850 			return (1);
11851 		}
11852 	}
11853 	return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
11854 	    tiwin, thflags, nxt_pkt));
11855 }
11856 
11857 static int
11858 rack_check_data_after_close(struct mbuf *m,
11859     struct tcpcb *tp, int32_t *tlen, struct tcphdr *th, struct socket *so)
11860 {
11861 	struct tcp_rack *rack;
11862 
11863 	rack = (struct tcp_rack *)tp->t_fb_ptr;
11864 	if (rack->rc_allow_data_af_clo == 0) {
11865 	close_now:
11866 		tcp_log_end_status(tp, TCP_EI_STATUS_DATA_A_CLOSE);
11867 		/* tcp_close will kill the inp pre-log the Reset */
11868 		tcp_log_end_status(tp, TCP_EI_STATUS_SERVER_RST);
11869 		tp = tcp_close(tp);
11870 		KMOD_TCPSTAT_INC(tcps_rcvafterclose);
11871 		ctf_do_dropwithreset(m, tp, th, BANDLIM_UNLIMITED, (*tlen));
11872 		return (1);
11873 	}
11874 	if (sbavail(&so->so_snd) == 0)
11875 		goto close_now;
11876 	/* Ok we allow data that is ignored and a followup reset */
11877 	tcp_log_end_status(tp, TCP_EI_STATUS_DATA_A_CLOSE);
11878 	tp->rcv_nxt = th->th_seq + *tlen;
11879 	tp->t_flags2 |= TF2_DROP_AF_DATA;
11880 	rack->r_wanted_output = 1;
11881 	*tlen = 0;
11882 	return (0);
11883 }
11884 
11885 /*
11886  * Return value of 1, the TCB is unlocked and most
11887  * likely gone, return value of 0, the TCP is still
11888  * locked.
11889  */
11890 static int
11891 rack_do_fin_wait_1(struct mbuf *m, struct tcphdr *th, struct socket *so,
11892     struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen,
11893     uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos)
11894 {
11895 	int32_t ret_val = 0;
11896 	int32_t ourfinisacked = 0;
11897 	struct tcp_rack *rack;
11898 
11899 	rack = (struct tcp_rack *)tp->t_fb_ptr;
11900 	ctf_calc_rwin(so, tp);
11901 
11902 	if ((thflags & TH_RST) ||
11903 	    (tp->t_fin_is_rst && (thflags & TH_FIN)))
11904 		return (__ctf_process_rst(m, th, so, tp,
11905 					  &rack->r_ctl.challenge_ack_ts,
11906 					  &rack->r_ctl.challenge_ack_cnt));
11907 	/*
11908 	 * RFC5961 Section 4.2 Send challenge ACK for any SYN in
11909 	 * synchronized state.
11910 	 */
11911 	if (thflags & TH_SYN) {
11912 		ctf_challenge_ack(m, th, tp, &ret_val);
11913 		return (ret_val);
11914 	}
11915 	/*
11916 	 * RFC 1323 PAWS: If we have a timestamp reply on this segment and
11917 	 * it's less than ts_recent, drop it.
11918 	 */
11919 	if ((to->to_flags & TOF_TS) != 0 && tp->ts_recent &&
11920 	    TSTMP_LT(to->to_tsval, tp->ts_recent)) {
11921 		if (ctf_ts_check(m, th, tp, tlen, thflags, &ret_val))
11922 			return (ret_val);
11923 	}
11924 	if (_ctf_drop_checks(to, m, th, tp, &tlen, &thflags, &drop_hdrlen, &ret_val,
11925 			      &rack->r_ctl.challenge_ack_ts,
11926 			      &rack->r_ctl.challenge_ack_cnt)) {
11927 		return (ret_val);
11928 	}
11929 	/*
11930 	 * If new data are received on a connection after the user processes
11931 	 * are gone, then RST the other end.
11932 	 */
11933 	if ((tp->t_flags & TF_CLOSED) && tlen &&
11934 	    rack_check_data_after_close(m, tp, &tlen, th, so))
11935 		return (1);
11936 	/*
11937 	 * If last ACK falls within this segment's sequence numbers, record
11938 	 * its timestamp. NOTE: 1) That the test incorporates suggestions
11939 	 * from the latest proposal of the tcplw@cray.com list (Braden
11940 	 * 1993/04/26). 2) That updating only on newer timestamps interferes
11941 	 * with our earlier PAWS tests, so this check should be solely
11942 	 * predicated on the sequence space of this segment. 3) That we
11943 	 * modify the segment boundary check to be Last.ACK.Sent <= SEG.SEQ
11944 	 * + SEG.Len  instead of RFC1323's Last.ACK.Sent < SEG.SEQ +
11945 	 * SEG.Len, This modified check allows us to overcome RFC1323's
11946 	 * limitations as described in Stevens TCP/IP Illustrated Vol. 2
11947 	 * p.869. In such cases, we can still calculate the RTT correctly
11948 	 * when RCV.NXT == Last.ACK.Sent.
11949 	 */
11950 	if ((to->to_flags & TOF_TS) != 0 &&
11951 	    SEQ_LEQ(th->th_seq, tp->last_ack_sent) &&
11952 	    SEQ_LEQ(tp->last_ack_sent, th->th_seq + tlen +
11953 	    ((thflags & (TH_SYN | TH_FIN)) != 0))) {
11954 		tp->ts_recent_age = tcp_ts_getticks();
11955 		tp->ts_recent = to->to_tsval;
11956 	}
11957 	/*
11958 	 * If the ACK bit is off:  if in SYN-RECEIVED state or SENDSYN flag
11959 	 * is on (half-synchronized state), then queue data for later
11960 	 * processing; else drop segment and return.
11961 	 */
11962 	if ((thflags & TH_ACK) == 0) {
11963 		if (tp->t_flags & TF_NEEDSYN) {
11964 			return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
11965 			    tiwin, thflags, nxt_pkt));
11966 		} else if (tp->t_flags & TF_ACKNOW) {
11967 			ctf_do_dropafterack(m, tp, th, thflags, tlen, &ret_val);
11968 			((struct tcp_rack *)tp->t_fb_ptr)->r_wanted_output = 1;
11969 			return (ret_val);
11970 		} else {
11971 			ctf_do_drop(m, NULL);
11972 			return (0);
11973 		}
11974 	}
11975 	/*
11976 	 * Ack processing.
11977 	 */
11978 	if (rack_process_ack(m, th, so, tp, to, tiwin, tlen, &ourfinisacked, thflags, &ret_val)) {
11979 		return (ret_val);
11980 	}
11981 	if (ourfinisacked) {
11982 		/*
11983 		 * If we can't receive any more data, then closing user can
11984 		 * proceed. Starting the timer is contrary to the
11985 		 * specification, but if we don't get a FIN we'll hang
11986 		 * forever.
11987 		 *
11988 		 * XXXjl: we should release the tp also, and use a
11989 		 * compressed state.
11990 		 */
11991 		if (so->so_rcv.sb_state & SBS_CANTRCVMORE) {
11992 			soisdisconnected(so);
11993 			tcp_timer_activate(tp, TT_2MSL,
11994 			    (tcp_fast_finwait2_recycle ?
11995 			    tcp_finwait2_timeout :
11996 			    TP_MAXIDLE(tp)));
11997 		}
11998 		tcp_state_change(tp, TCPS_FIN_WAIT_2);
11999 	}
12000 	if (sbavail(&so->so_snd)) {
12001 		if (ctf_progress_timeout_check(tp, true)) {
12002 			rack_log_progress_event((struct tcp_rack *)tp->t_fb_ptr,
12003 						tp, tick, PROGRESS_DROP, __LINE__);
12004 			ctf_do_dropwithreset_conn(m, tp, th, BANDLIM_RST_OPENPORT, tlen);
12005 			return (1);
12006 		}
12007 	}
12008 	return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
12009 	    tiwin, thflags, nxt_pkt));
12010 }
12011 
12012 /*
12013  * Return value of 1, the TCB is unlocked and most
12014  * likely gone, return value of 0, the TCP is still
12015  * locked.
12016  */
12017 static int
12018 rack_do_closing(struct mbuf *m, struct tcphdr *th, struct socket *so,
12019     struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen,
12020     uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos)
12021 {
12022 	int32_t ret_val = 0;
12023 	int32_t ourfinisacked = 0;
12024 	struct tcp_rack *rack;
12025 
12026 	rack = (struct tcp_rack *)tp->t_fb_ptr;
12027 	ctf_calc_rwin(so, tp);
12028 
12029 	if ((thflags & TH_RST) ||
12030 	    (tp->t_fin_is_rst && (thflags & TH_FIN)))
12031 		return (__ctf_process_rst(m, th, so, tp,
12032 					  &rack->r_ctl.challenge_ack_ts,
12033 					  &rack->r_ctl.challenge_ack_cnt));
12034 	/*
12035 	 * RFC5961 Section 4.2 Send challenge ACK for any SYN in
12036 	 * synchronized state.
12037 	 */
12038 	if (thflags & TH_SYN) {
12039 		ctf_challenge_ack(m, th, tp, &ret_val);
12040 		return (ret_val);
12041 	}
12042 	/*
12043 	 * RFC 1323 PAWS: If we have a timestamp reply on this segment and
12044 	 * it's less than ts_recent, drop it.
12045 	 */
12046 	if ((to->to_flags & TOF_TS) != 0 && tp->ts_recent &&
12047 	    TSTMP_LT(to->to_tsval, tp->ts_recent)) {
12048 		if (ctf_ts_check(m, th, tp, tlen, thflags, &ret_val))
12049 			return (ret_val);
12050 	}
12051 	if (_ctf_drop_checks(to, m, th, tp, &tlen, &thflags, &drop_hdrlen, &ret_val,
12052 			      &rack->r_ctl.challenge_ack_ts,
12053 			      &rack->r_ctl.challenge_ack_cnt)) {
12054 		return (ret_val);
12055 	}
12056 	/*
12057 	 * If new data are received on a connection after the user processes
12058 	 * are gone, then RST the other end.
12059 	 */
12060 	if ((tp->t_flags & TF_CLOSED) && tlen &&
12061 	    rack_check_data_after_close(m, tp, &tlen, th, so))
12062 		return (1);
12063 	/*
12064 	 * If last ACK falls within this segment's sequence numbers, record
12065 	 * its timestamp. NOTE: 1) That the test incorporates suggestions
12066 	 * from the latest proposal of the tcplw@cray.com list (Braden
12067 	 * 1993/04/26). 2) That updating only on newer timestamps interferes
12068 	 * with our earlier PAWS tests, so this check should be solely
12069 	 * predicated on the sequence space of this segment. 3) That we
12070 	 * modify the segment boundary check to be Last.ACK.Sent <= SEG.SEQ
12071 	 * + SEG.Len  instead of RFC1323's Last.ACK.Sent < SEG.SEQ +
12072 	 * SEG.Len, This modified check allows us to overcome RFC1323's
12073 	 * limitations as described in Stevens TCP/IP Illustrated Vol. 2
12074 	 * p.869. In such cases, we can still calculate the RTT correctly
12075 	 * when RCV.NXT == Last.ACK.Sent.
12076 	 */
12077 	if ((to->to_flags & TOF_TS) != 0 &&
12078 	    SEQ_LEQ(th->th_seq, tp->last_ack_sent) &&
12079 	    SEQ_LEQ(tp->last_ack_sent, th->th_seq + tlen +
12080 	    ((thflags & (TH_SYN | TH_FIN)) != 0))) {
12081 		tp->ts_recent_age = tcp_ts_getticks();
12082 		tp->ts_recent = to->to_tsval;
12083 	}
12084 	/*
12085 	 * If the ACK bit is off:  if in SYN-RECEIVED state or SENDSYN flag
12086 	 * is on (half-synchronized state), then queue data for later
12087 	 * processing; else drop segment and return.
12088 	 */
12089 	if ((thflags & TH_ACK) == 0) {
12090 		if (tp->t_flags & TF_NEEDSYN) {
12091 			return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
12092 			    tiwin, thflags, nxt_pkt));
12093 		} else if (tp->t_flags & TF_ACKNOW) {
12094 			ctf_do_dropafterack(m, tp, th, thflags, tlen, &ret_val);
12095 			((struct tcp_rack *)tp->t_fb_ptr)->r_wanted_output = 1;
12096 			return (ret_val);
12097 		} else {
12098 			ctf_do_drop(m, NULL);
12099 			return (0);
12100 		}
12101 	}
12102 	/*
12103 	 * Ack processing.
12104 	 */
12105 	if (rack_process_ack(m, th, so, tp, to, tiwin, tlen, &ourfinisacked, thflags, &ret_val)) {
12106 		return (ret_val);
12107 	}
12108 	if (ourfinisacked) {
12109 		tcp_twstart(tp);
12110 		m_freem(m);
12111 		return (1);
12112 	}
12113 	if (sbavail(&so->so_snd)) {
12114 		if (ctf_progress_timeout_check(tp, true)) {
12115 			rack_log_progress_event((struct tcp_rack *)tp->t_fb_ptr,
12116 						tp, tick, PROGRESS_DROP, __LINE__);
12117 			ctf_do_dropwithreset_conn(m, tp, th, BANDLIM_RST_OPENPORT, tlen);
12118 			return (1);
12119 		}
12120 	}
12121 	return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
12122 	    tiwin, thflags, nxt_pkt));
12123 }
12124 
12125 /*
12126  * Return value of 1, the TCB is unlocked and most
12127  * likely gone, return value of 0, the TCP is still
12128  * locked.
12129  */
12130 static int
12131 rack_do_lastack(struct mbuf *m, struct tcphdr *th, struct socket *so,
12132     struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen,
12133     uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos)
12134 {
12135 	int32_t ret_val = 0;
12136 	int32_t ourfinisacked = 0;
12137 	struct tcp_rack *rack;
12138 
12139 	rack = (struct tcp_rack *)tp->t_fb_ptr;
12140 	ctf_calc_rwin(so, tp);
12141 
12142 	if ((thflags & TH_RST) ||
12143 	    (tp->t_fin_is_rst && (thflags & TH_FIN)))
12144 		return (__ctf_process_rst(m, th, so, tp,
12145 					  &rack->r_ctl.challenge_ack_ts,
12146 					  &rack->r_ctl.challenge_ack_cnt));
12147 	/*
12148 	 * RFC5961 Section 4.2 Send challenge ACK for any SYN in
12149 	 * synchronized state.
12150 	 */
12151 	if (thflags & TH_SYN) {
12152 		ctf_challenge_ack(m, th, tp, &ret_val);
12153 		return (ret_val);
12154 	}
12155 	/*
12156 	 * RFC 1323 PAWS: If we have a timestamp reply on this segment and
12157 	 * it's less than ts_recent, drop it.
12158 	 */
12159 	if ((to->to_flags & TOF_TS) != 0 && tp->ts_recent &&
12160 	    TSTMP_LT(to->to_tsval, tp->ts_recent)) {
12161 		if (ctf_ts_check(m, th, tp, tlen, thflags, &ret_val))
12162 			return (ret_val);
12163 	}
12164 	if (_ctf_drop_checks(to, m, th, tp, &tlen, &thflags, &drop_hdrlen, &ret_val,
12165 			      &rack->r_ctl.challenge_ack_ts,
12166 			      &rack->r_ctl.challenge_ack_cnt)) {
12167 		return (ret_val);
12168 	}
12169 	/*
12170 	 * If new data are received on a connection after the user processes
12171 	 * are gone, then RST the other end.
12172 	 */
12173 	if ((tp->t_flags & TF_CLOSED) && tlen &&
12174 	    rack_check_data_after_close(m, tp, &tlen, th, so))
12175 		return (1);
12176 	/*
12177 	 * If last ACK falls within this segment's sequence numbers, record
12178 	 * its timestamp. NOTE: 1) That the test incorporates suggestions
12179 	 * from the latest proposal of the tcplw@cray.com list (Braden
12180 	 * 1993/04/26). 2) That updating only on newer timestamps interferes
12181 	 * with our earlier PAWS tests, so this check should be solely
12182 	 * predicated on the sequence space of this segment. 3) That we
12183 	 * modify the segment boundary check to be Last.ACK.Sent <= SEG.SEQ
12184 	 * + SEG.Len  instead of RFC1323's Last.ACK.Sent < SEG.SEQ +
12185 	 * SEG.Len, This modified check allows us to overcome RFC1323's
12186 	 * limitations as described in Stevens TCP/IP Illustrated Vol. 2
12187 	 * p.869. In such cases, we can still calculate the RTT correctly
12188 	 * when RCV.NXT == Last.ACK.Sent.
12189 	 */
12190 	if ((to->to_flags & TOF_TS) != 0 &&
12191 	    SEQ_LEQ(th->th_seq, tp->last_ack_sent) &&
12192 	    SEQ_LEQ(tp->last_ack_sent, th->th_seq + tlen +
12193 	    ((thflags & (TH_SYN | TH_FIN)) != 0))) {
12194 		tp->ts_recent_age = tcp_ts_getticks();
12195 		tp->ts_recent = to->to_tsval;
12196 	}
12197 	/*
12198 	 * If the ACK bit is off:  if in SYN-RECEIVED state or SENDSYN flag
12199 	 * is on (half-synchronized state), then queue data for later
12200 	 * processing; else drop segment and return.
12201 	 */
12202 	if ((thflags & TH_ACK) == 0) {
12203 		if (tp->t_flags & TF_NEEDSYN) {
12204 			return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
12205 			    tiwin, thflags, nxt_pkt));
12206 		} else if (tp->t_flags & TF_ACKNOW) {
12207 			ctf_do_dropafterack(m, tp, th, thflags, tlen, &ret_val);
12208 			((struct tcp_rack *)tp->t_fb_ptr)->r_wanted_output = 1;
12209 			return (ret_val);
12210 		} else {
12211 			ctf_do_drop(m, NULL);
12212 			return (0);
12213 		}
12214 	}
12215 	/*
12216 	 * case TCPS_LAST_ACK: Ack processing.
12217 	 */
12218 	if (rack_process_ack(m, th, so, tp, to, tiwin, tlen, &ourfinisacked, thflags, &ret_val)) {
12219 		return (ret_val);
12220 	}
12221 	if (ourfinisacked) {
12222 		tp = tcp_close(tp);
12223 		ctf_do_drop(m, tp);
12224 		return (1);
12225 	}
12226 	if (sbavail(&so->so_snd)) {
12227 		if (ctf_progress_timeout_check(tp, true)) {
12228 			rack_log_progress_event((struct tcp_rack *)tp->t_fb_ptr,
12229 						tp, tick, PROGRESS_DROP, __LINE__);
12230 			ctf_do_dropwithreset_conn(m, tp, th, BANDLIM_RST_OPENPORT, tlen);
12231 			return (1);
12232 		}
12233 	}
12234 	return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
12235 	    tiwin, thflags, nxt_pkt));
12236 }
12237 
12238 /*
12239  * Return value of 1, the TCB is unlocked and most
12240  * likely gone, return value of 0, the TCP is still
12241  * locked.
12242  */
12243 static int
12244 rack_do_fin_wait_2(struct mbuf *m, struct tcphdr *th, struct socket *so,
12245     struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen,
12246     uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos)
12247 {
12248 	int32_t ret_val = 0;
12249 	int32_t ourfinisacked = 0;
12250 	struct tcp_rack *rack;
12251 
12252 	rack = (struct tcp_rack *)tp->t_fb_ptr;
12253 	ctf_calc_rwin(so, tp);
12254 
12255 	/* Reset receive buffer auto scaling when not in bulk receive mode. */
12256 	if ((thflags & TH_RST) ||
12257 	    (tp->t_fin_is_rst && (thflags & TH_FIN)))
12258 		return (__ctf_process_rst(m, th, so, tp,
12259 					  &rack->r_ctl.challenge_ack_ts,
12260 					  &rack->r_ctl.challenge_ack_cnt));
12261 	/*
12262 	 * RFC5961 Section 4.2 Send challenge ACK for any SYN in
12263 	 * synchronized state.
12264 	 */
12265 	if (thflags & TH_SYN) {
12266 		ctf_challenge_ack(m, th, tp, &ret_val);
12267 		return (ret_val);
12268 	}
12269 	/*
12270 	 * RFC 1323 PAWS: If we have a timestamp reply on this segment and
12271 	 * it's less than ts_recent, drop it.
12272 	 */
12273 	if ((to->to_flags & TOF_TS) != 0 && tp->ts_recent &&
12274 	    TSTMP_LT(to->to_tsval, tp->ts_recent)) {
12275 		if (ctf_ts_check(m, th, tp, tlen, thflags, &ret_val))
12276 			return (ret_val);
12277 	}
12278 	if (_ctf_drop_checks(to, m, th, tp, &tlen, &thflags, &drop_hdrlen, &ret_val,
12279 			      &rack->r_ctl.challenge_ack_ts,
12280 			      &rack->r_ctl.challenge_ack_cnt)) {
12281 		return (ret_val);
12282 	}
12283 	/*
12284 	 * If new data are received on a connection after the user processes
12285 	 * are gone, then RST the other end.
12286 	 */
12287 	if ((tp->t_flags & TF_CLOSED) && tlen &&
12288 	    rack_check_data_after_close(m, tp, &tlen, th, so))
12289 		return (1);
12290 	/*
12291 	 * If last ACK falls within this segment's sequence numbers, record
12292 	 * its timestamp. NOTE: 1) That the test incorporates suggestions
12293 	 * from the latest proposal of the tcplw@cray.com list (Braden
12294 	 * 1993/04/26). 2) That updating only on newer timestamps interferes
12295 	 * with our earlier PAWS tests, so this check should be solely
12296 	 * predicated on the sequence space of this segment. 3) That we
12297 	 * modify the segment boundary check to be Last.ACK.Sent <= SEG.SEQ
12298 	 * + SEG.Len  instead of RFC1323's Last.ACK.Sent < SEG.SEQ +
12299 	 * SEG.Len, This modified check allows us to overcome RFC1323's
12300 	 * limitations as described in Stevens TCP/IP Illustrated Vol. 2
12301 	 * p.869. In such cases, we can still calculate the RTT correctly
12302 	 * when RCV.NXT == Last.ACK.Sent.
12303 	 */
12304 	if ((to->to_flags & TOF_TS) != 0 &&
12305 	    SEQ_LEQ(th->th_seq, tp->last_ack_sent) &&
12306 	    SEQ_LEQ(tp->last_ack_sent, th->th_seq + tlen +
12307 	    ((thflags & (TH_SYN | TH_FIN)) != 0))) {
12308 		tp->ts_recent_age = tcp_ts_getticks();
12309 		tp->ts_recent = to->to_tsval;
12310 	}
12311 	/*
12312 	 * If the ACK bit is off:  if in SYN-RECEIVED state or SENDSYN flag
12313 	 * is on (half-synchronized state), then queue data for later
12314 	 * processing; else drop segment and return.
12315 	 */
12316 	if ((thflags & TH_ACK) == 0) {
12317 		if (tp->t_flags & TF_NEEDSYN) {
12318 			return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
12319 			    tiwin, thflags, nxt_pkt));
12320 		} else if (tp->t_flags & TF_ACKNOW) {
12321 			ctf_do_dropafterack(m, tp, th, thflags, tlen, &ret_val);
12322 			((struct tcp_rack *)tp->t_fb_ptr)->r_wanted_output = 1;
12323 			return (ret_val);
12324 		} else {
12325 			ctf_do_drop(m, NULL);
12326 			return (0);
12327 		}
12328 	}
12329 	/*
12330 	 * Ack processing.
12331 	 */
12332 	if (rack_process_ack(m, th, so, tp, to, tiwin, tlen, &ourfinisacked, thflags, &ret_val)) {
12333 		return (ret_val);
12334 	}
12335 	if (sbavail(&so->so_snd)) {
12336 		if (ctf_progress_timeout_check(tp, true)) {
12337 			rack_log_progress_event((struct tcp_rack *)tp->t_fb_ptr,
12338 						tp, tick, PROGRESS_DROP, __LINE__);
12339 			ctf_do_dropwithreset_conn(m, tp, th, BANDLIM_RST_OPENPORT, tlen);
12340 			return (1);
12341 		}
12342 	}
12343 	return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
12344 	    tiwin, thflags, nxt_pkt));
12345 }
12346 
12347 static void inline
12348 rack_clear_rate_sample(struct tcp_rack *rack)
12349 {
12350 	rack->r_ctl.rack_rs.rs_flags = RACK_RTT_EMPTY;
12351 	rack->r_ctl.rack_rs.rs_rtt_cnt = 0;
12352 	rack->r_ctl.rack_rs.rs_rtt_tot = 0;
12353 }
12354 
12355 static void
12356 rack_set_pace_segments(struct tcpcb *tp, struct tcp_rack *rack, uint32_t line, uint64_t *fill_override)
12357 {
12358 	uint64_t bw_est, rate_wanted;
12359 	int chged = 0;
12360 	uint32_t user_max, orig_min, orig_max;
12361 
12362 	orig_min = rack->r_ctl.rc_pace_min_segs;
12363 	orig_max = rack->r_ctl.rc_pace_max_segs;
12364 	user_max = ctf_fixed_maxseg(tp) * rack->rc_user_set_max_segs;
12365 	if (ctf_fixed_maxseg(tp) != rack->r_ctl.rc_pace_min_segs)
12366 		chged = 1;
12367 	rack->r_ctl.rc_pace_min_segs = ctf_fixed_maxseg(tp);
12368 	if (rack->use_fixed_rate || rack->rc_force_max_seg) {
12369 		if (user_max != rack->r_ctl.rc_pace_max_segs)
12370 			chged = 1;
12371 	}
12372 	if (rack->rc_force_max_seg) {
12373 		rack->r_ctl.rc_pace_max_segs = user_max;
12374 	} else if (rack->use_fixed_rate) {
12375 		bw_est = rack_get_bw(rack);
12376 		if ((rack->r_ctl.crte == NULL) ||
12377 		    (bw_est != rack->r_ctl.crte->rate)) {
12378 			rack->r_ctl.rc_pace_max_segs = user_max;
12379 		} else {
12380 			/* We are pacing right at the hardware rate */
12381 			uint32_t segsiz;
12382 
12383 			segsiz = min(ctf_fixed_maxseg(tp),
12384 				     rack->r_ctl.rc_pace_min_segs);
12385 			rack->r_ctl.rc_pace_max_segs = tcp_get_pacing_burst_size(
12386 				                           tp, bw_est, segsiz, 0,
12387 							   rack->r_ctl.crte, NULL);
12388 		}
12389 	} else if (rack->rc_always_pace) {
12390 		if (rack->r_ctl.gp_bw ||
12391 #ifdef NETFLIX_PEAKRATE
12392 		    rack->rc_tp->t_maxpeakrate ||
12393 #endif
12394 		    rack->r_ctl.init_rate) {
12395 			/* We have a rate of some sort set */
12396 			uint32_t  orig;
12397 
12398 			bw_est = rack_get_bw(rack);
12399 			orig = rack->r_ctl.rc_pace_max_segs;
12400 			if (fill_override)
12401 				rate_wanted = *fill_override;
12402 			else
12403 				rate_wanted = rack_get_output_bw(rack, bw_est, NULL, NULL);
12404 			if (rate_wanted) {
12405 				/* We have something */
12406 				rack->r_ctl.rc_pace_max_segs = rack_get_pacing_len(rack,
12407 										   rate_wanted,
12408 										   ctf_fixed_maxseg(rack->rc_tp));
12409 			} else
12410 				rack->r_ctl.rc_pace_max_segs = rack->r_ctl.rc_pace_min_segs;
12411 			if (orig != rack->r_ctl.rc_pace_max_segs)
12412 				chged = 1;
12413 		} else if ((rack->r_ctl.gp_bw == 0) &&
12414 			   (rack->r_ctl.rc_pace_max_segs == 0)) {
12415 			/*
12416 			 * If we have nothing limit us to bursting
12417 			 * out IW sized pieces.
12418 			 */
12419 			chged = 1;
12420 			rack->r_ctl.rc_pace_max_segs = rc_init_window(rack);
12421 		}
12422 	}
12423 	if (rack->r_ctl.rc_pace_max_segs > PACE_MAX_IP_BYTES) {
12424 		chged = 1;
12425 		rack->r_ctl.rc_pace_max_segs = PACE_MAX_IP_BYTES;
12426 	}
12427 	if (chged)
12428 		rack_log_type_pacing_sizes(tp, rack, orig_min, orig_max, line, 2);
12429 }
12430 
12431 
12432 static void
12433 rack_init_fsb_block(struct tcpcb *tp, struct tcp_rack *rack)
12434 {
12435 #ifdef INET6
12436 	struct ip6_hdr *ip6 = NULL;
12437 #endif
12438 #ifdef INET
12439 	struct ip *ip = NULL;
12440 #endif
12441 	struct udphdr *udp = NULL;
12442 
12443 	/* Ok lets fill in the fast block, it can only be used with no IP options! */
12444 #ifdef INET6
12445 	if (rack->r_is_v6) {
12446 		rack->r_ctl.fsb.tcp_ip_hdr_len = sizeof(struct ip6_hdr) + sizeof(struct tcphdr);
12447 		ip6 = (struct ip6_hdr *)rack->r_ctl.fsb.tcp_ip_hdr;
12448 		if (tp->t_port) {
12449 			rack->r_ctl.fsb.tcp_ip_hdr_len += sizeof(struct udphdr);
12450 			udp = (struct udphdr *)((caddr_t)ip6 + sizeof(struct ip6_hdr));
12451 			udp->uh_sport = htons(V_tcp_udp_tunneling_port);
12452 			udp->uh_dport = tp->t_port;
12453 			rack->r_ctl.fsb.udp = udp;
12454 			rack->r_ctl.fsb.th = (struct tcphdr *)(udp + 1);
12455 		} else
12456 		{
12457 			rack->r_ctl.fsb.th = (struct tcphdr *)(ip6 + 1);
12458 			rack->r_ctl.fsb.udp = NULL;
12459 		}
12460 		tcpip_fillheaders(rack->rc_inp,
12461 				  tp->t_port,
12462 				  ip6, rack->r_ctl.fsb.th);
12463 	} else
12464 #endif				/* INET6 */
12465 	{
12466 		rack->r_ctl.fsb.tcp_ip_hdr_len = sizeof(struct tcpiphdr);
12467 		ip = (struct ip *)rack->r_ctl.fsb.tcp_ip_hdr;
12468 		if (tp->t_port) {
12469 			rack->r_ctl.fsb.tcp_ip_hdr_len += sizeof(struct udphdr);
12470 			udp = (struct udphdr *)((caddr_t)ip + sizeof(struct ip));
12471 			udp->uh_sport = htons(V_tcp_udp_tunneling_port);
12472 			udp->uh_dport = tp->t_port;
12473 			rack->r_ctl.fsb.udp = udp;
12474 			rack->r_ctl.fsb.th = (struct tcphdr *)(udp + 1);
12475 		} else
12476 		{
12477 			rack->r_ctl.fsb.udp = NULL;
12478 			rack->r_ctl.fsb.th = (struct tcphdr *)(ip + 1);
12479 		}
12480 		tcpip_fillheaders(rack->rc_inp,
12481 				  tp->t_port,
12482 				  ip, rack->r_ctl.fsb.th);
12483 	}
12484 	rack->r_fsb_inited = 1;
12485 }
12486 
12487 static int
12488 rack_init_fsb(struct tcpcb *tp, struct tcp_rack *rack)
12489 {
12490 	/*
12491 	 * Allocate the larger of spaces V6 if available else just
12492 	 * V4 and include udphdr (overbook)
12493 	 */
12494 #ifdef INET6
12495 	rack->r_ctl.fsb.tcp_ip_hdr_len = sizeof(struct ip6_hdr) + sizeof(struct tcphdr) + sizeof(struct udphdr);
12496 #else
12497 	rack->r_ctl.fsb.tcp_ip_hdr_len = sizeof(struct tcpiphdr) + sizeof(struct udphdr);
12498 #endif
12499 	rack->r_ctl.fsb.tcp_ip_hdr = malloc(rack->r_ctl.fsb.tcp_ip_hdr_len,
12500 					    M_TCPFSB, M_NOWAIT|M_ZERO);
12501 	if (rack->r_ctl.fsb.tcp_ip_hdr == NULL) {
12502 		return (ENOMEM);
12503 	}
12504 	rack->r_fsb_inited = 0;
12505 	return (0);
12506 }
12507 
12508 static int
12509 rack_init(struct tcpcb *tp)
12510 {
12511 	struct tcp_rack *rack = NULL;
12512 #ifdef INVARIANTS
12513 	struct rack_sendmap *insret;
12514 #endif
12515 	uint32_t iwin, snt, us_cts;
12516 	int err;
12517 
12518 	tp->t_fb_ptr = uma_zalloc(rack_pcb_zone, M_NOWAIT);
12519 	if (tp->t_fb_ptr == NULL) {
12520 		/*
12521 		 * We need to allocate memory but cant. The INP and INP_INFO
12522 		 * locks and they are recursive (happens during setup. So a
12523 		 * scheme to drop the locks fails :(
12524 		 *
12525 		 */
12526 		return (ENOMEM);
12527 	}
12528 	memset(tp->t_fb_ptr, 0, sizeof(struct tcp_rack));
12529 
12530 	rack = (struct tcp_rack *)tp->t_fb_ptr;
12531 	RB_INIT(&rack->r_ctl.rc_mtree);
12532 	TAILQ_INIT(&rack->r_ctl.rc_free);
12533 	TAILQ_INIT(&rack->r_ctl.rc_tmap);
12534 	rack->rc_tp = tp;
12535 	rack->rc_inp = tp->t_inpcb;
12536 	/* Set the flag */
12537 	rack->r_is_v6 = (tp->t_inpcb->inp_vflag & INP_IPV6) != 0;
12538 	/* Probably not needed but lets be sure */
12539 	rack_clear_rate_sample(rack);
12540 	/*
12541 	 * Save off the default values, socket options will poke
12542 	 * at these if pacing is not on or we have not yet
12543 	 * reached where pacing is on (gp_ready/fixed enabled).
12544 	 * When they get set into the CC module (when gp_ready
12545 	 * is enabled or we enable fixed) then we will set these
12546 	 * values into the CC and place in here the old values
12547 	 * so we have a restoral. Then we will set the flag
12548 	 * rc_pacing_cc_set. That way whenever we turn off pacing
12549 	 * or switch off this stack, we will know to go restore
12550 	 * the saved values.
12551 	 */
12552 	rack->r_ctl.rc_saved_beta.beta = V_newreno_beta_ecn;
12553 	rack->r_ctl.rc_saved_beta.beta_ecn = V_newreno_beta_ecn;
12554 	/* We want abe like behavior as well */
12555 	rack->r_ctl.rc_saved_beta.newreno_flags |= CC_NEWRENO_BETA_ECN_ENABLED;
12556 	rack->r_ctl.rc_reorder_fade = rack_reorder_fade;
12557 	rack->rc_allow_data_af_clo = rack_ignore_data_after_close;
12558 	rack->r_ctl.rc_tlp_threshold = rack_tlp_thresh;
12559 	rack->r_ctl.roundends = tp->snd_max;
12560 	if (use_rack_rr)
12561 		rack->use_rack_rr = 1;
12562 	if (V_tcp_delack_enabled)
12563 		tp->t_delayed_ack = 1;
12564 	else
12565 		tp->t_delayed_ack = 0;
12566 #ifdef TCP_ACCOUNTING
12567 	if (rack_tcp_accounting) {
12568 		tp->t_flags2 |= TF2_TCP_ACCOUNTING;
12569 	}
12570 #endif
12571 	if (rack_enable_shared_cwnd)
12572 		rack->rack_enable_scwnd = 1;
12573 	rack->rc_user_set_max_segs = rack_hptsi_segments;
12574 	rack->rc_force_max_seg = 0;
12575 	if (rack_use_imac_dack)
12576 		rack->rc_dack_mode = 1;
12577 	TAILQ_INIT(&rack->r_ctl.opt_list);
12578 	rack->r_ctl.rc_reorder_shift = rack_reorder_thresh;
12579 	rack->r_ctl.rc_pkt_delay = rack_pkt_delay;
12580 	rack->r_ctl.rc_tlp_cwnd_reduce = rack_lower_cwnd_at_tlp;
12581 	rack->r_ctl.rc_lowest_us_rtt = 0xffffffff;
12582 	rack->r_ctl.rc_highest_us_rtt = 0;
12583 	rack->r_ctl.bw_rate_cap = rack_bw_rate_cap;
12584 	rack->r_ctl.timer_slop = TICKS_2_USEC(tcp_rexmit_slop);
12585 	if (rack_use_cmp_acks)
12586 		rack->r_use_cmp_ack = 1;
12587 	if (rack_disable_prr)
12588 		rack->rack_no_prr = 1;
12589 	if (rack_gp_no_rec_chg)
12590 		rack->rc_gp_no_rec_chg = 1;
12591 	if (rack_pace_every_seg && tcp_can_enable_pacing()) {
12592 		rack->rc_always_pace = 1;
12593 		if (rack->use_fixed_rate || rack->gp_ready)
12594 			rack_set_cc_pacing(rack);
12595 	} else
12596 		rack->rc_always_pace = 0;
12597 	if (rack_enable_mqueue_for_nonpaced || rack->r_use_cmp_ack)
12598 		rack->r_mbuf_queue = 1;
12599 	else
12600 		rack->r_mbuf_queue = 0;
12601 	if  (rack->r_mbuf_queue || rack->rc_always_pace || rack->r_use_cmp_ack)
12602 		tp->t_inpcb->inp_flags2 |= INP_SUPPORTS_MBUFQ;
12603 	else
12604 		tp->t_inpcb->inp_flags2 &= ~INP_SUPPORTS_MBUFQ;
12605 	rack_set_pace_segments(tp, rack, __LINE__, NULL);
12606 	if (rack_limits_scwnd)
12607 		rack->r_limit_scw = 1;
12608 	else
12609 		rack->r_limit_scw = 0;
12610 	rack->rc_labc = V_tcp_abc_l_var;
12611 	rack->r_ctl.rc_high_rwnd = tp->snd_wnd;
12612 	rack->r_ctl.cwnd_to_use = tp->snd_cwnd;
12613 	rack->r_ctl.rc_rate_sample_method = rack_rate_sample_method;
12614 	rack->rack_tlp_threshold_use = rack_tlp_threshold_use;
12615 	rack->r_ctl.rc_prr_sendalot = rack_send_a_lot_in_prr;
12616 	rack->r_ctl.rc_min_to = rack_min_to;
12617 	microuptime(&rack->r_ctl.act_rcv_time);
12618 	rack->r_ctl.rc_last_time_decay = rack->r_ctl.act_rcv_time;
12619 	rack->rc_init_win = rack_default_init_window;
12620 	rack->r_ctl.rack_per_of_gp_ss = rack_per_of_gp_ss;
12621 	if (rack_hw_up_only)
12622 		rack->r_up_only = 1;
12623 	if (rack_do_dyn_mul) {
12624 		/* When dynamic adjustment is on CA needs to start at 100% */
12625 		rack->rc_gp_dyn_mul = 1;
12626 		if (rack_do_dyn_mul >= 100)
12627 			rack->r_ctl.rack_per_of_gp_ca = rack_do_dyn_mul;
12628 	} else
12629 		rack->r_ctl.rack_per_of_gp_ca = rack_per_of_gp_ca;
12630 	rack->r_ctl.rack_per_of_gp_rec = rack_per_of_gp_rec;
12631 	rack->r_ctl.rack_per_of_gp_probertt = rack_per_of_gp_probertt;
12632 	rack->r_ctl.rc_tlp_rxt_last_time = tcp_tv_to_mssectick(&rack->r_ctl.act_rcv_time);
12633 	setup_time_filter_small(&rack->r_ctl.rc_gp_min_rtt, FILTER_TYPE_MIN,
12634 				rack_probertt_filter_life);
12635 	us_cts = tcp_tv_to_usectick(&rack->r_ctl.act_rcv_time);
12636 	rack->r_ctl.rc_lower_rtt_us_cts = us_cts;
12637 	rack->r_ctl.rc_time_of_last_probertt = us_cts;
12638 	rack->r_ctl.challenge_ack_ts = tcp_ts_getticks();
12639 	rack->r_ctl.rc_time_probertt_starts = 0;
12640 	if (rack_dsack_std_based & 0x1) {
12641 		/* Basically this means all rack timers are at least (srtt + 1/4 srtt) */
12642 		rack->rc_rack_tmr_std_based = 1;
12643 	}
12644 	if (rack_dsack_std_based & 0x2) {
12645 		/* Basically this means  rack timers are extended based on dsack by up to (2 * srtt) */
12646 		rack->rc_rack_use_dsack = 1;
12647 	}
12648 	/* We require at least one measurement, even if the sysctl is 0 */
12649 	if (rack_req_measurements)
12650 		rack->r_ctl.req_measurements = rack_req_measurements;
12651 	else
12652 		rack->r_ctl.req_measurements = 1;
12653 	if (rack_enable_hw_pacing)
12654 		rack->rack_hdw_pace_ena = 1;
12655 	if (rack_hw_rate_caps)
12656 		rack->r_rack_hw_rate_caps = 1;
12657 	/* Do we force on detection? */
12658 #ifdef NETFLIX_EXP_DETECTION
12659 	if (tcp_force_detection)
12660 		rack->do_detection = 1;
12661 	else
12662 #endif
12663 		rack->do_detection = 0;
12664 	if (rack_non_rxt_use_cr)
12665 		rack->rack_rec_nonrxt_use_cr = 1;
12666 	err = rack_init_fsb(tp, rack);
12667 	if (err) {
12668 		uma_zfree(rack_pcb_zone, tp->t_fb_ptr);
12669 		tp->t_fb_ptr = NULL;
12670 		return (err);
12671 	}
12672 	if (tp->snd_una != tp->snd_max) {
12673 		/* Create a send map for the current outstanding data */
12674 		struct rack_sendmap *rsm;
12675 
12676 		rsm = rack_alloc(rack);
12677 		if (rsm == NULL) {
12678 			uma_zfree(rack_pcb_zone, tp->t_fb_ptr);
12679 			tp->t_fb_ptr = NULL;
12680 			return (ENOMEM);
12681 		}
12682 		rsm->r_no_rtt_allowed = 1;
12683 		rsm->r_tim_lastsent[0] = rack_to_usec_ts(&rack->r_ctl.act_rcv_time);
12684 		rsm->r_rtr_cnt = 1;
12685 		rsm->r_rtr_bytes = 0;
12686 		if (tp->t_flags & TF_SENTFIN)
12687 			rsm->r_flags |= RACK_HAS_FIN;
12688 		if ((tp->snd_una == tp->iss) &&
12689 		    !TCPS_HAVEESTABLISHED(tp->t_state))
12690 			rsm->r_flags |= RACK_HAS_SYN;
12691 		rsm->r_start = tp->snd_una;
12692 		rsm->r_end = tp->snd_max;
12693 		rsm->r_dupack = 0;
12694 		if (rack->rc_inp->inp_socket->so_snd.sb_mb != NULL) {
12695 			rsm->m = sbsndmbuf(&rack->rc_inp->inp_socket->so_snd, 0, &rsm->soff);
12696 			if (rsm->m)
12697 				rsm->orig_m_len = rsm->m->m_len;
12698 			else
12699 				rsm->orig_m_len = 0;
12700 		} else {
12701 			/*
12702 			 * This can happen if we have a stand-alone FIN or
12703 			 *  SYN.
12704 			 */
12705 			rsm->m = NULL;
12706 			rsm->orig_m_len = 0;
12707 			rsm->soff = 0;
12708 		}
12709 #ifndef INVARIANTS
12710 		(void)RB_INSERT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm);
12711 #else
12712 		insret = RB_INSERT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm);
12713 		if (insret != NULL) {
12714 			panic("Insert in rb tree fails ret:%p rack:%p rsm:%p",
12715 			      insret, rack, rsm);
12716 		}
12717 #endif
12718 		TAILQ_INSERT_TAIL(&rack->r_ctl.rc_tmap, rsm, r_tnext);
12719 		rsm->r_in_tmap = 1;
12720 	}
12721 	/*
12722 	 * Timers in Rack are kept in microseconds so lets
12723 	 * convert any initial incoming variables
12724 	 * from ticks into usecs. Note that we
12725 	 * also change the values of t_srtt and t_rttvar, if
12726 	 * they are non-zero. They are kept with a 5
12727 	 * bit decimal so we have to carefully convert
12728 	 * these to get the full precision.
12729 	 */
12730 	rack_convert_rtts(tp);
12731 	tp->t_rttlow = TICKS_2_USEC(tp->t_rttlow);
12732 	if (rack_do_hystart) {
12733 		tp->ccv->flags |= CCF_HYSTART_ALLOWED;
12734 		if (rack_do_hystart > 1)
12735 			tp->ccv->flags |= CCF_HYSTART_CAN_SH_CWND;
12736 		if (rack_do_hystart > 2)
12737 			tp->ccv->flags |= CCF_HYSTART_CONS_SSTH;
12738 	}
12739 	if (rack_def_profile)
12740 		rack_set_profile(rack, rack_def_profile);
12741 	/* Cancel the GP measurement in progress */
12742 	tp->t_flags &= ~TF_GPUTINPROG;
12743 	if (SEQ_GT(tp->snd_max, tp->iss))
12744 		snt = tp->snd_max - tp->iss;
12745 	else
12746 		snt = 0;
12747 	iwin = rc_init_window(rack);
12748 	if (snt < iwin) {
12749 		/* We are not past the initial window
12750 		 * so we need to make sure cwnd is
12751 		 * correct.
12752 		 */
12753 		if (tp->snd_cwnd < iwin)
12754 			tp->snd_cwnd = iwin;
12755 		/*
12756 		 * If we are within the initial window
12757 		 * we want ssthresh to be unlimited. Setting
12758 		 * it to the rwnd (which the default stack does
12759 		 * and older racks) is not really a good idea
12760 		 * since we want to be in SS and grow both the
12761 		 * cwnd and the rwnd (via dynamic rwnd growth). If
12762 		 * we set it to the rwnd then as the peer grows its
12763 		 * rwnd we will be stuck in CA and never hit SS.
12764 		 *
12765 		 * Its far better to raise it up high (this takes the
12766 		 * risk that there as been a loss already, probably
12767 		 * we should have an indicator in all stacks of loss
12768 		 * but we don't), but considering the normal use this
12769 		 * is a risk worth taking. The consequences of not
12770 		 * hitting SS are far worse than going one more time
12771 		 * into it early on (before we have sent even a IW).
12772 		 * It is highly unlikely that we will have had a loss
12773 		 * before getting the IW out.
12774 		 */
12775 		tp->snd_ssthresh = 0xffffffff;
12776 	}
12777 	rack_stop_all_timers(tp);
12778 	/* Lets setup the fsb block */
12779 	rack_start_hpts_timer(rack, tp, tcp_get_usecs(NULL), 0, 0, 0);
12780 	rack_log_rtt_shrinks(rack,  us_cts,  tp->t_rxtcur,
12781 			     __LINE__, RACK_RTTS_INIT);
12782 	return (0);
12783 }
12784 
12785 static int
12786 rack_handoff_ok(struct tcpcb *tp)
12787 {
12788 	if ((tp->t_state == TCPS_CLOSED) ||
12789 	    (tp->t_state == TCPS_LISTEN)) {
12790 		/* Sure no problem though it may not stick */
12791 		return (0);
12792 	}
12793 	if ((tp->t_state == TCPS_SYN_SENT) ||
12794 	    (tp->t_state == TCPS_SYN_RECEIVED)) {
12795 		/*
12796 		 * We really don't know if you support sack,
12797 		 * you have to get to ESTAB or beyond to tell.
12798 		 */
12799 		return (EAGAIN);
12800 	}
12801 	if ((tp->t_flags & TF_SENTFIN) && ((tp->snd_max - tp->snd_una) > 1)) {
12802 		/*
12803 		 * Rack will only send a FIN after all data is acknowledged.
12804 		 * So in this case we have more data outstanding. We can't
12805 		 * switch stacks until either all data and only the FIN
12806 		 * is left (in which case rack_init() now knows how
12807 		 * to deal with that) <or> all is acknowledged and we
12808 		 * are only left with incoming data, though why you
12809 		 * would want to switch to rack after all data is acknowledged
12810 		 * I have no idea (rrs)!
12811 		 */
12812 		return (EAGAIN);
12813 	}
12814 	if ((tp->t_flags & TF_SACK_PERMIT) || rack_sack_not_required){
12815 		return (0);
12816 	}
12817 	/*
12818 	 * If we reach here we don't do SACK on this connection so we can
12819 	 * never do rack.
12820 	 */
12821 	return (EINVAL);
12822 }
12823 
12824 
12825 static void
12826 rack_fini(struct tcpcb *tp, int32_t tcb_is_purged)
12827 {
12828 	if (tp->t_fb_ptr) {
12829 		struct tcp_rack *rack;
12830 		struct rack_sendmap *rsm, *nrsm;
12831 #ifdef INVARIANTS
12832 		struct rack_sendmap *rm;
12833 #endif
12834 
12835 		rack = (struct tcp_rack *)tp->t_fb_ptr;
12836 		if (tp->t_in_pkt) {
12837 			/*
12838 			 * It is unsafe to process the packets since a
12839 			 * reset may be lurking in them (its rare but it
12840 			 * can occur). If we were to find a RST, then we
12841 			 * would end up dropping the connection and the
12842 			 * INP lock, so when we return the caller (tcp_usrreq)
12843 			 * will blow up when it trys to unlock the inp.
12844 			 */
12845 			struct mbuf *save, *m;
12846 
12847 			m = tp->t_in_pkt;
12848 			tp->t_in_pkt = NULL;
12849 			tp->t_tail_pkt = NULL;
12850 			while (m) {
12851 				save = m->m_nextpkt;
12852 				m->m_nextpkt = NULL;
12853 				m_freem(m);
12854 				m = save;
12855 			}
12856 		}
12857 		tp->t_flags &= ~TF_FORCEDATA;
12858 #ifdef NETFLIX_SHARED_CWND
12859 		if (rack->r_ctl.rc_scw) {
12860 			uint32_t limit;
12861 
12862 			if (rack->r_limit_scw)
12863 				limit = max(1, rack->r_ctl.rc_lowest_us_rtt);
12864 			else
12865 				limit = 0;
12866 			tcp_shared_cwnd_free_full(tp, rack->r_ctl.rc_scw,
12867 						  rack->r_ctl.rc_scw_index,
12868 						  limit);
12869 			rack->r_ctl.rc_scw = NULL;
12870 		}
12871 #endif
12872 		if (rack->r_ctl.fsb.tcp_ip_hdr) {
12873 			free(rack->r_ctl.fsb.tcp_ip_hdr, M_TCPFSB);
12874 			rack->r_ctl.fsb.tcp_ip_hdr = NULL;
12875 			rack->r_ctl.fsb.th = NULL;
12876 		}
12877 		/* Convert back to ticks, with  */
12878 		if (tp->t_srtt > 1) {
12879 			uint32_t val, frac;
12880 
12881 			val = USEC_2_TICKS(tp->t_srtt);
12882 			frac = tp->t_srtt % (HPTS_USEC_IN_SEC / hz);
12883 			tp->t_srtt = val << TCP_RTT_SHIFT;
12884 			/*
12885 			 * frac is the fractional part here is left
12886 			 * over from converting to hz and shifting.
12887 			 * We need to convert this to the 5 bit
12888 			 * remainder.
12889 			 */
12890 			if (frac) {
12891 				if (hz == 1000) {
12892 					frac = (((uint64_t)frac *  (uint64_t)TCP_RTT_SCALE) / (uint64_t)HPTS_USEC_IN_MSEC);
12893 				} else {
12894 					frac = (((uint64_t)frac * (uint64_t)(hz) * (uint64_t)TCP_RTT_SCALE) /(uint64_t)HPTS_USEC_IN_SEC);
12895 				}
12896 				tp->t_srtt += frac;
12897 			}
12898 		}
12899 		if (tp->t_rttvar) {
12900 			uint32_t val, frac;
12901 
12902 			val = USEC_2_TICKS(tp->t_rttvar);
12903 			frac = tp->t_srtt % (HPTS_USEC_IN_SEC / hz);
12904 			tp->t_rttvar = val <<  TCP_RTTVAR_SHIFT;
12905 			/*
12906 			 * frac is the fractional part here is left
12907 			 * over from converting to hz and shifting.
12908 			 * We need to convert this to the 5 bit
12909 			 * remainder.
12910 			 */
12911 			if (frac) {
12912 				if (hz == 1000) {
12913 					frac = (((uint64_t)frac *  (uint64_t)TCP_RTT_SCALE) / (uint64_t)HPTS_USEC_IN_MSEC);
12914 				} else {
12915 					frac = (((uint64_t)frac * (uint64_t)(hz) * (uint64_t)TCP_RTT_SCALE) /(uint64_t)HPTS_USEC_IN_SEC);
12916 				}
12917 				tp->t_rttvar += frac;
12918 			}
12919 		}
12920 		tp->t_rxtcur = USEC_2_TICKS(tp->t_rxtcur);
12921 		tp->t_rttlow = USEC_2_TICKS(tp->t_rttlow);
12922 		if (rack->rc_always_pace) {
12923 			tcp_decrement_paced_conn();
12924 			rack_undo_cc_pacing(rack);
12925 			rack->rc_always_pace = 0;
12926 		}
12927 		/* Clean up any options if they were not applied */
12928 		while (!TAILQ_EMPTY(&rack->r_ctl.opt_list)) {
12929 			struct deferred_opt_list *dol;
12930 
12931 			dol = TAILQ_FIRST(&rack->r_ctl.opt_list);
12932 			TAILQ_REMOVE(&rack->r_ctl.opt_list, dol, next);
12933 			free(dol, M_TCPDO);
12934 		}
12935 		/* rack does not use force data but other stacks may clear it */
12936 		if (rack->r_ctl.crte != NULL) {
12937 			tcp_rel_pacing_rate(rack->r_ctl.crte, tp);
12938 			rack->rack_hdrw_pacing = 0;
12939 			rack->r_ctl.crte = NULL;
12940 		}
12941 #ifdef TCP_BLACKBOX
12942 		tcp_log_flowend(tp);
12943 #endif
12944 		RB_FOREACH_SAFE(rsm, rack_rb_tree_head, &rack->r_ctl.rc_mtree, nrsm) {
12945 #ifndef INVARIANTS
12946 			(void)RB_REMOVE(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm);
12947 #else
12948 			rm = RB_REMOVE(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm);
12949 			if (rm != rsm) {
12950 				panic("At fini, rack:%p rsm:%p rm:%p",
12951 				      rack, rsm, rm);
12952 			}
12953 #endif
12954 			uma_zfree(rack_zone, rsm);
12955 		}
12956 		rsm = TAILQ_FIRST(&rack->r_ctl.rc_free);
12957 		while (rsm) {
12958 			TAILQ_REMOVE(&rack->r_ctl.rc_free, rsm, r_tnext);
12959 			uma_zfree(rack_zone, rsm);
12960 			rsm = TAILQ_FIRST(&rack->r_ctl.rc_free);
12961 		}
12962 		rack->rc_free_cnt = 0;
12963 		uma_zfree(rack_pcb_zone, tp->t_fb_ptr);
12964 		tp->t_fb_ptr = NULL;
12965 	}
12966 	if (tp->t_inpcb) {
12967 		tp->t_inpcb->inp_flags2 &= ~INP_SUPPORTS_MBUFQ;
12968 		tp->t_inpcb->inp_flags2 &= ~INP_MBUF_QUEUE_READY;
12969 		tp->t_inpcb->inp_flags2 &= ~INP_DONT_SACK_QUEUE;
12970 		tp->t_inpcb->inp_flags2 &= ~INP_MBUF_ACKCMP;
12971 		/* Cancel the GP measurement in progress */
12972 		tp->t_flags &= ~TF_GPUTINPROG;
12973 		tp->t_inpcb->inp_flags2 &= ~INP_MBUF_L_ACKS;
12974 	}
12975 	/* Make sure snd_nxt is correctly set */
12976 	tp->snd_nxt = tp->snd_max;
12977 }
12978 
12979 static void
12980 rack_set_state(struct tcpcb *tp, struct tcp_rack *rack)
12981 {
12982 	if ((rack->r_state == TCPS_CLOSED) && (tp->t_state != TCPS_CLOSED)) {
12983 		rack->r_is_v6 = (tp->t_inpcb->inp_vflag & INP_IPV6) != 0;
12984 	}
12985 	switch (tp->t_state) {
12986 	case TCPS_SYN_SENT:
12987 		rack->r_state = TCPS_SYN_SENT;
12988 		rack->r_substate = rack_do_syn_sent;
12989 		break;
12990 	case TCPS_SYN_RECEIVED:
12991 		rack->r_state = TCPS_SYN_RECEIVED;
12992 		rack->r_substate = rack_do_syn_recv;
12993 		break;
12994 	case TCPS_ESTABLISHED:
12995 		rack_set_pace_segments(tp, rack, __LINE__, NULL);
12996 		rack->r_state = TCPS_ESTABLISHED;
12997 		rack->r_substate = rack_do_established;
12998 		break;
12999 	case TCPS_CLOSE_WAIT:
13000 		rack_set_pace_segments(tp, rack, __LINE__, NULL);
13001 		rack->r_state = TCPS_CLOSE_WAIT;
13002 		rack->r_substate = rack_do_close_wait;
13003 		break;
13004 	case TCPS_FIN_WAIT_1:
13005 		rack_set_pace_segments(tp, rack, __LINE__, NULL);
13006 		rack->r_state = TCPS_FIN_WAIT_1;
13007 		rack->r_substate = rack_do_fin_wait_1;
13008 		break;
13009 	case TCPS_CLOSING:
13010 		rack_set_pace_segments(tp, rack, __LINE__, NULL);
13011 		rack->r_state = TCPS_CLOSING;
13012 		rack->r_substate = rack_do_closing;
13013 		break;
13014 	case TCPS_LAST_ACK:
13015 		rack_set_pace_segments(tp, rack, __LINE__, NULL);
13016 		rack->r_state = TCPS_LAST_ACK;
13017 		rack->r_substate = rack_do_lastack;
13018 		break;
13019 	case TCPS_FIN_WAIT_2:
13020 		rack_set_pace_segments(tp, rack, __LINE__, NULL);
13021 		rack->r_state = TCPS_FIN_WAIT_2;
13022 		rack->r_substate = rack_do_fin_wait_2;
13023 		break;
13024 	case TCPS_LISTEN:
13025 	case TCPS_CLOSED:
13026 	case TCPS_TIME_WAIT:
13027 	default:
13028 		break;
13029 	};
13030 	if (rack->r_use_cmp_ack && TCPS_HAVEESTABLISHED(tp->t_state))
13031 		rack->rc_inp->inp_flags2 |= INP_MBUF_ACKCMP;
13032 
13033 }
13034 
13035 static void
13036 rack_timer_audit(struct tcpcb *tp, struct tcp_rack *rack, struct sockbuf *sb)
13037 {
13038 	/*
13039 	 * We received an ack, and then did not
13040 	 * call send or were bounced out due to the
13041 	 * hpts was running. Now a timer is up as well, is
13042 	 * it the right timer?
13043 	 */
13044 	struct rack_sendmap *rsm;
13045 	int tmr_up;
13046 
13047 	tmr_up = rack->r_ctl.rc_hpts_flags & PACE_TMR_MASK;
13048 	if (rack->rc_in_persist && (tmr_up == PACE_TMR_PERSIT))
13049 		return;
13050 	rsm = TAILQ_FIRST(&rack->r_ctl.rc_tmap);
13051 	if (((rsm == NULL) || (tp->t_state < TCPS_ESTABLISHED)) &&
13052 	    (tmr_up == PACE_TMR_RXT)) {
13053 		/* Should be an RXT */
13054 		return;
13055 	}
13056 	if (rsm == NULL) {
13057 		/* Nothing outstanding? */
13058 		if (tp->t_flags & TF_DELACK) {
13059 			if (tmr_up == PACE_TMR_DELACK)
13060 				/* We are supposed to have delayed ack up and we do */
13061 				return;
13062 		} else if (sbavail(&tp->t_inpcb->inp_socket->so_snd) && (tmr_up == PACE_TMR_RXT)) {
13063 			/*
13064 			 * if we hit enobufs then we would expect the possibility
13065 			 * of nothing outstanding and the RXT up (and the hptsi timer).
13066 			 */
13067 			return;
13068 		} else if (((V_tcp_always_keepalive ||
13069 			     rack->rc_inp->inp_socket->so_options & SO_KEEPALIVE) &&
13070 			    (tp->t_state <= TCPS_CLOSING)) &&
13071 			   (tmr_up == PACE_TMR_KEEP) &&
13072 			   (tp->snd_max == tp->snd_una)) {
13073 			/* We should have keep alive up and we do */
13074 			return;
13075 		}
13076 	}
13077 	if (SEQ_GT(tp->snd_max, tp->snd_una) &&
13078 		   ((tmr_up == PACE_TMR_TLP) ||
13079 		    (tmr_up == PACE_TMR_RACK) ||
13080 		    (tmr_up == PACE_TMR_RXT))) {
13081 		/*
13082 		 * Either a Rack, TLP or RXT is fine if  we
13083 		 * have outstanding data.
13084 		 */
13085 		return;
13086 	} else if (tmr_up == PACE_TMR_DELACK) {
13087 		/*
13088 		 * If the delayed ack was going to go off
13089 		 * before the rtx/tlp/rack timer were going to
13090 		 * expire, then that would be the timer in control.
13091 		 * Note we don't check the time here trusting the
13092 		 * code is correct.
13093 		 */
13094 		return;
13095 	}
13096 	/*
13097 	 * Ok the timer originally started is not what we want now.
13098 	 * We will force the hpts to be stopped if any, and restart
13099 	 * with the slot set to what was in the saved slot.
13100 	 */
13101 	if (tcp_in_hpts(rack->rc_inp)) {
13102 		if (rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT) {
13103 			uint32_t us_cts;
13104 
13105 			us_cts = tcp_get_usecs(NULL);
13106 			if (TSTMP_GT(rack->r_ctl.rc_last_output_to, us_cts)) {
13107 				rack->r_early = 1;
13108 				rack->r_ctl.rc_agg_early += (rack->r_ctl.rc_last_output_to - us_cts);
13109 			}
13110 			rack->r_ctl.rc_hpts_flags &= ~PACE_PKT_OUTPUT;
13111 		}
13112 		tcp_hpts_remove(tp->t_inpcb);
13113 	}
13114 	rack_timer_cancel(tp, rack, rack->r_ctl.rc_rcvtime, __LINE__);
13115 	rack_start_hpts_timer(rack, tp, tcp_get_usecs(NULL), 0, 0, 0);
13116 }
13117 
13118 
13119 static void
13120 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)
13121 {
13122 	if ((SEQ_LT(tp->snd_wl1, seq) ||
13123 	    (tp->snd_wl1 == seq && (SEQ_LT(tp->snd_wl2, ack) ||
13124 	    (tp->snd_wl2 == ack && tiwin > tp->snd_wnd))))) {
13125 		/* keep track of pure window updates */
13126 		if ((tp->snd_wl2 == ack) && (tiwin > tp->snd_wnd))
13127 			KMOD_TCPSTAT_INC(tcps_rcvwinupd);
13128 		tp->snd_wnd = tiwin;
13129 		rack_validate_fo_sendwin_up(tp, rack);
13130 		tp->snd_wl1 = seq;
13131 		tp->snd_wl2 = ack;
13132 		if (tp->snd_wnd > tp->max_sndwnd)
13133 			tp->max_sndwnd = tp->snd_wnd;
13134 	    rack->r_wanted_output = 1;
13135 	} else if ((tp->snd_wl2 == ack) && (tiwin < tp->snd_wnd)) {
13136 		tp->snd_wnd = tiwin;
13137 		rack_validate_fo_sendwin_up(tp, rack);
13138 		tp->snd_wl1 = seq;
13139 		tp->snd_wl2 = ack;
13140 	} else {
13141 		/* Not a valid win update */
13142 		return;
13143 	}
13144 	/* Do we exit persists? */
13145 	if ((rack->rc_in_persist != 0) &&
13146 	    (tp->snd_wnd >= min((rack->r_ctl.rc_high_rwnd/2),
13147 				rack->r_ctl.rc_pace_min_segs))) {
13148 		rack_exit_persist(tp, rack, cts);
13149 	}
13150 	/* Do we enter persists? */
13151 	if ((rack->rc_in_persist == 0) &&
13152 	    (tp->snd_wnd < min((rack->r_ctl.rc_high_rwnd/2), rack->r_ctl.rc_pace_min_segs)) &&
13153 	    TCPS_HAVEESTABLISHED(tp->t_state) &&
13154 	    ((tp->snd_max == tp->snd_una) || rack->rc_has_collapsed) &&
13155 	    sbavail(&tp->t_inpcb->inp_socket->so_snd) &&
13156 	    (sbavail(&tp->t_inpcb->inp_socket->so_snd) > tp->snd_wnd)) {
13157 		/*
13158 		 * Here the rwnd is less than
13159 		 * the pacing size, we are established,
13160 		 * nothing is outstanding, and there is
13161 		 * data to send. Enter persists.
13162 		 */
13163 		rack_enter_persist(tp, rack, rack->r_ctl.rc_rcvtime);
13164 	}
13165 }
13166 
13167 static void
13168 rack_log_input_packet(struct tcpcb *tp, struct tcp_rack *rack, struct tcp_ackent *ae, int ackval, uint32_t high_seq)
13169 {
13170 
13171 	if (tp->t_logstate != TCP_LOG_STATE_OFF) {
13172 		union tcp_log_stackspecific log;
13173 		struct timeval ltv;
13174 		char tcp_hdr_buf[60];
13175 		struct tcphdr *th;
13176 		struct timespec ts;
13177 		uint32_t orig_snd_una;
13178 		uint8_t xx = 0;
13179 
13180 #ifdef NETFLIX_HTTP_LOGGING
13181 		struct http_sendfile_track *http_req;
13182 
13183 		if (SEQ_GT(ae->ack, tp->snd_una)) {
13184 			http_req = tcp_http_find_req_for_seq(tp, (ae->ack-1));
13185 		} else {
13186 			http_req = tcp_http_find_req_for_seq(tp, ae->ack);
13187 		}
13188 #endif
13189 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
13190 		log.u_bbr.inhpts = tcp_in_hpts(rack->rc_inp);
13191 		if (rack->rack_no_prr == 0)
13192 			log.u_bbr.flex1 = rack->r_ctl.rc_prr_sndcnt;
13193 		else
13194 			log.u_bbr.flex1 = 0;
13195 		log.u_bbr.use_lt_bw = rack->r_ent_rec_ns;
13196 		log.u_bbr.use_lt_bw <<= 1;
13197 		log.u_bbr.use_lt_bw |= rack->r_might_revert;
13198 		log.u_bbr.flex2 = rack->r_ctl.rc_num_maps_alloced;
13199 		log.u_bbr.inflight = ctf_flight_size(tp, rack->r_ctl.rc_sacked);
13200 		log.u_bbr.pkts_out = tp->t_maxseg;
13201 		log.u_bbr.flex4 = rack->r_ctl.rc_hpts_flags;
13202 		log.u_bbr.flex7 = 1;
13203 		log.u_bbr.lost = ae->flags;
13204 		log.u_bbr.cwnd_gain = ackval;
13205 		log.u_bbr.pacing_gain = 0x2;
13206 		if (ae->flags & TSTMP_HDWR) {
13207 			/* Record the hardware timestamp if present */
13208 			log.u_bbr.flex3 = M_TSTMP;
13209 			ts.tv_sec = ae->timestamp / 1000000000;
13210 			ts.tv_nsec = ae->timestamp % 1000000000;
13211 			ltv.tv_sec = ts.tv_sec;
13212 			ltv.tv_usec = ts.tv_nsec / 1000;
13213 			log.u_bbr.lt_epoch = tcp_tv_to_usectick(&ltv);
13214 		} else if (ae->flags & TSTMP_LRO) {
13215 			/* Record the LRO the arrival timestamp */
13216 			log.u_bbr.flex3 = M_TSTMP_LRO;
13217 			ts.tv_sec = ae->timestamp / 1000000000;
13218 			ts.tv_nsec = ae->timestamp % 1000000000;
13219 			ltv.tv_sec = ts.tv_sec;
13220 			ltv.tv_usec = ts.tv_nsec / 1000;
13221 			log.u_bbr.flex5 = tcp_tv_to_usectick(&ltv);
13222 		}
13223 		log.u_bbr.timeStamp = tcp_get_usecs(&ltv);
13224 		/* Log the rcv time */
13225 		log.u_bbr.delRate = ae->timestamp;
13226 #ifdef NETFLIX_HTTP_LOGGING
13227 		log.u_bbr.applimited = tp->t_http_closed;
13228 		log.u_bbr.applimited <<= 8;
13229 		log.u_bbr.applimited |= tp->t_http_open;
13230 		log.u_bbr.applimited <<= 8;
13231 		log.u_bbr.applimited |= tp->t_http_req;
13232 		if (http_req) {
13233 			/* Copy out any client req info */
13234 			/* seconds */
13235 			log.u_bbr.pkt_epoch = (http_req->localtime / HPTS_USEC_IN_SEC);
13236 			/* useconds */
13237 			log.u_bbr.delivered = (http_req->localtime % HPTS_USEC_IN_SEC);
13238 			log.u_bbr.rttProp = http_req->timestamp;
13239 			log.u_bbr.cur_del_rate = http_req->start;
13240 			if (http_req->flags & TCP_HTTP_TRACK_FLG_OPEN) {
13241 				log.u_bbr.flex8 |= 1;
13242 			} else {
13243 				log.u_bbr.flex8 |= 2;
13244 				log.u_bbr.bw_inuse = http_req->end;
13245 			}
13246 			log.u_bbr.flex6 = http_req->start_seq;
13247 			if (http_req->flags & TCP_HTTP_TRACK_FLG_COMP) {
13248 				log.u_bbr.flex8 |= 4;
13249 				log.u_bbr.epoch = http_req->end_seq;
13250 			}
13251 		}
13252 #endif
13253 		memset(tcp_hdr_buf, 0, sizeof(tcp_hdr_buf));
13254 		th = (struct tcphdr *)tcp_hdr_buf;
13255 		th->th_seq = ae->seq;
13256 		th->th_ack = ae->ack;
13257 		th->th_win = ae->win;
13258 		/* Now fill in the ports */
13259 		th->th_sport = tp->t_inpcb->inp_fport;
13260 		th->th_dport = tp->t_inpcb->inp_lport;
13261 		tcp_set_flags(th, ae->flags);
13262 		/* Now do we have a timestamp option? */
13263 		if (ae->flags & HAS_TSTMP) {
13264 			u_char *cp;
13265 			uint32_t val;
13266 
13267 			th->th_off = ((sizeof(struct tcphdr) + TCPOLEN_TSTAMP_APPA) >> 2);
13268 			cp = (u_char *)(th + 1);
13269 			*cp = TCPOPT_NOP;
13270 			cp++;
13271 			*cp = TCPOPT_NOP;
13272 			cp++;
13273 			*cp = TCPOPT_TIMESTAMP;
13274 			cp++;
13275 			*cp = TCPOLEN_TIMESTAMP;
13276 			cp++;
13277 			val = htonl(ae->ts_value);
13278 			bcopy((char *)&val,
13279 			      (char *)cp, sizeof(uint32_t));
13280 			val = htonl(ae->ts_echo);
13281 			bcopy((char *)&val,
13282 			      (char *)(cp + 4), sizeof(uint32_t));
13283 		} else
13284 			th->th_off = (sizeof(struct tcphdr) >> 2);
13285 
13286 		/*
13287 		 * For sane logging we need to play a little trick.
13288 		 * If the ack were fully processed we would have moved
13289 		 * snd_una to high_seq, but since compressed acks are
13290 		 * processed in two phases, at this point (logging) snd_una
13291 		 * won't be advanced. So we would see multiple acks showing
13292 		 * the advancement. We can prevent that by "pretending" that
13293 		 * snd_una was advanced and then un-advancing it so that the
13294 		 * logging code has the right value for tlb_snd_una.
13295 		 */
13296 		if (tp->snd_una != high_seq) {
13297 			orig_snd_una = tp->snd_una;
13298 			tp->snd_una = high_seq;
13299 			xx = 1;
13300 		} else
13301 			xx = 0;
13302 		TCP_LOG_EVENTP(tp, th,
13303 			       &tp->t_inpcb->inp_socket->so_rcv,
13304 			       &tp->t_inpcb->inp_socket->so_snd, TCP_LOG_IN, 0,
13305 			       0, &log, true, &ltv);
13306 		if (xx) {
13307 			tp->snd_una = orig_snd_una;
13308 		}
13309 	}
13310 
13311 }
13312 
13313 static void
13314 rack_handle_probe_response(struct tcp_rack *rack, uint32_t tiwin, uint32_t us_cts)
13315 {
13316 	uint32_t us_rtt;
13317 	/*
13318 	 * A persist or keep-alive was forced out, update our
13319 	 * min rtt time. Note now worry about lost responses.
13320 	 * When a subsequent keep-alive or persist times out
13321 	 * and forced_ack is still on, then the last probe
13322 	 * was not responded to. In such cases we have a
13323 	 * sysctl that controls the behavior. Either we apply
13324 	 * the rtt but with reduced confidence (0). Or we just
13325 	 * plain don't apply the rtt estimate. Having data flow
13326 	 * will clear the probe_not_answered flag i.e. cum-ack
13327 	 * move forward <or> exiting and reentering persists.
13328 	 */
13329 
13330 	rack->forced_ack = 0;
13331 	rack->rc_tp->t_rxtshift = 0;
13332 	if ((rack->rc_in_persist &&
13333 	     (tiwin == rack->rc_tp->snd_wnd)) ||
13334 	    (rack->rc_in_persist == 0)) {
13335 		/*
13336 		 * In persists only apply the RTT update if this is
13337 		 * a response to our window probe. And that
13338 		 * means the rwnd sent must match the current
13339 		 * snd_wnd. If it does not, then we got a
13340 		 * window update ack instead. For keepalive
13341 		 * we allow the answer no matter what the window.
13342 		 *
13343 		 * Note that if the probe_not_answered is set then
13344 		 * the forced_ack_ts is the oldest one i.e. the first
13345 		 * probe sent that might have been lost. This assures
13346 		 * us that if we do calculate an RTT it is longer not
13347 		 * some short thing.
13348 		 */
13349 		if (rack->rc_in_persist)
13350 			counter_u64_add(rack_persists_acks, 1);
13351 		us_rtt = us_cts - rack->r_ctl.forced_ack_ts;
13352 		if (us_rtt == 0)
13353 			us_rtt = 1;
13354 		if (rack->probe_not_answered == 0) {
13355 			rack_apply_updated_usrtt(rack, us_rtt, us_cts);
13356 			tcp_rack_xmit_timer(rack, us_rtt, 0, us_rtt, 3, NULL, 1);
13357 		} else {
13358 			/* We have a retransmitted probe here too */
13359 			if (rack_apply_rtt_with_reduced_conf) {
13360 				rack_apply_updated_usrtt(rack, us_rtt, us_cts);
13361 				tcp_rack_xmit_timer(rack, us_rtt, 0, us_rtt, 0, NULL, 1);
13362 			}
13363 		}
13364 	}
13365 }
13366 
13367 static int
13368 rack_do_compressed_ack_processing(struct tcpcb *tp, struct socket *so, struct mbuf *m, int nxt_pkt, struct timeval *tv)
13369 {
13370 	/*
13371 	 * Handle a "special" compressed ack mbuf. Each incoming
13372 	 * ack has only four possible dispositions:
13373 	 *
13374 	 * A) It moves the cum-ack forward
13375 	 * B) It is behind the cum-ack.
13376 	 * C) It is a window-update ack.
13377 	 * D) It is a dup-ack.
13378 	 *
13379 	 * Note that we can have between 1 -> TCP_COMP_ACK_ENTRIES
13380 	 * in the incoming mbuf. We also need to still pay attention
13381 	 * to nxt_pkt since there may be another packet after this
13382 	 * one.
13383 	 */
13384 #ifdef TCP_ACCOUNTING
13385 	uint64_t ts_val;
13386 	uint64_t rdstc;
13387 #endif
13388 	int segsiz;
13389 	struct timespec ts;
13390 	struct tcp_rack *rack;
13391 	struct tcp_ackent *ae;
13392 	uint32_t tiwin, ms_cts, cts, acked, acked_amount, high_seq, win_seq, the_win, win_upd_ack;
13393 	int cnt, i, did_out, ourfinisacked = 0;
13394 	struct tcpopt to_holder, *to = NULL;
13395 #ifdef TCP_ACCOUNTING
13396 	int win_up_req = 0;
13397 #endif
13398 	int nsegs = 0;
13399 	int under_pacing = 1;
13400 	int recovery = 0;
13401 #ifdef TCP_ACCOUNTING
13402 	sched_pin();
13403 #endif
13404 	rack = (struct tcp_rack *)tp->t_fb_ptr;
13405 	if (rack->gp_ready &&
13406 	    (rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT))
13407 		under_pacing = 0;
13408 	else
13409 		under_pacing = 1;
13410 
13411 	if (rack->r_state != tp->t_state)
13412 		rack_set_state(tp, rack);
13413 	if ((tp->t_state >= TCPS_FIN_WAIT_1) &&
13414 	    (tp->t_flags & TF_GPUTINPROG)) {
13415 		/*
13416 		 * We have a goodput in progress
13417 		 * and we have entered a late state.
13418 		 * Do we have enough data in the sb
13419 		 * to handle the GPUT request?
13420 		 */
13421 		uint32_t bytes;
13422 
13423 		bytes = tp->gput_ack - tp->gput_seq;
13424 		if (SEQ_GT(tp->gput_seq, tp->snd_una))
13425 			bytes += tp->gput_seq - tp->snd_una;
13426 		if (bytes > sbavail(&tp->t_inpcb->inp_socket->so_snd)) {
13427 			/*
13428 			 * There are not enough bytes in the socket
13429 			 * buffer that have been sent to cover this
13430 			 * measurement. Cancel it.
13431 			 */
13432 			rack_log_pacing_delay_calc(rack, (tp->gput_ack - tp->gput_seq) /*flex2*/,
13433 						   rack->r_ctl.rc_gp_srtt /*flex1*/,
13434 						   tp->gput_seq,
13435 						   0, 0, 18, __LINE__, NULL, 0);
13436 			tp->t_flags &= ~TF_GPUTINPROG;
13437 		}
13438 	}
13439 	to = &to_holder;
13440 	to->to_flags = 0;
13441 	KASSERT((m->m_len >= sizeof(struct tcp_ackent)),
13442 		("tp:%p m_cmpack:%p with invalid len:%u", tp, m, m->m_len));
13443 	cnt = m->m_len / sizeof(struct tcp_ackent);
13444 	counter_u64_add(rack_multi_single_eq, cnt);
13445 	high_seq = tp->snd_una;
13446 	the_win = tp->snd_wnd;
13447 	win_seq = tp->snd_wl1;
13448 	win_upd_ack = tp->snd_wl2;
13449 	cts = tcp_tv_to_usectick(tv);
13450 	ms_cts = tcp_tv_to_mssectick(tv);
13451 	rack->r_ctl.rc_rcvtime = cts;
13452 	segsiz = ctf_fixed_maxseg(tp);
13453 	if ((rack->rc_gp_dyn_mul) &&
13454 	    (rack->use_fixed_rate == 0) &&
13455 	    (rack->rc_always_pace)) {
13456 		/* Check in on probertt */
13457 		rack_check_probe_rtt(rack, cts);
13458 	}
13459 	for (i = 0; i < cnt; i++) {
13460 #ifdef TCP_ACCOUNTING
13461 		ts_val = get_cyclecount();
13462 #endif
13463 		rack_clear_rate_sample(rack);
13464 		ae = ((mtod(m, struct tcp_ackent *)) + i);
13465 		/* Setup the window */
13466 		tiwin = ae->win << tp->snd_scale;
13467 		if (tiwin > rack->r_ctl.rc_high_rwnd)
13468 			rack->r_ctl.rc_high_rwnd = tiwin;
13469 		/* figure out the type of ack */
13470 		if (SEQ_LT(ae->ack, high_seq)) {
13471 			/* Case B*/
13472 			ae->ack_val_set = ACK_BEHIND;
13473 		} else if (SEQ_GT(ae->ack, high_seq)) {
13474 			/* Case A */
13475 			ae->ack_val_set = ACK_CUMACK;
13476 		} else if ((tiwin == the_win) && (rack->rc_in_persist == 0)){
13477 			/* Case D */
13478 			ae->ack_val_set = ACK_DUPACK;
13479 		} else {
13480 			/* Case C */
13481 			ae->ack_val_set = ACK_RWND;
13482 		}
13483 		rack_log_input_packet(tp, rack, ae, ae->ack_val_set, high_seq);
13484 		/* Validate timestamp */
13485 		if (ae->flags & HAS_TSTMP) {
13486 			/* Setup for a timestamp */
13487 			to->to_flags = TOF_TS;
13488 			ae->ts_echo -= tp->ts_offset;
13489 			to->to_tsecr = ae->ts_echo;
13490 			to->to_tsval = ae->ts_value;
13491 			/*
13492 			 * If echoed timestamp is later than the current time, fall back to
13493 			 * non RFC1323 RTT calculation.  Normalize timestamp if syncookies
13494 			 * were used when this connection was established.
13495 			 */
13496 			if (TSTMP_GT(ae->ts_echo, ms_cts))
13497 				to->to_tsecr = 0;
13498 			if (tp->ts_recent &&
13499 			    TSTMP_LT(ae->ts_value, tp->ts_recent)) {
13500 				if (ctf_ts_check_ac(tp, (ae->flags & 0xff))) {
13501 #ifdef TCP_ACCOUNTING
13502 					rdstc = get_cyclecount();
13503 					if (rdstc > ts_val) {
13504 						counter_u64_add(tcp_proc_time[ae->ack_val_set] ,
13505 								(rdstc - ts_val));
13506 						if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
13507 							tp->tcp_proc_time[ae->ack_val_set] += (rdstc - ts_val);
13508 						}
13509 					}
13510 #endif
13511 					continue;
13512 				}
13513 			}
13514 			if (SEQ_LEQ(ae->seq, tp->last_ack_sent) &&
13515 			    SEQ_LEQ(tp->last_ack_sent, ae->seq)) {
13516 				tp->ts_recent_age = tcp_ts_getticks();
13517 				tp->ts_recent = ae->ts_value;
13518 			}
13519 		} else {
13520 			/* Setup for a no options */
13521 			to->to_flags = 0;
13522 		}
13523 		/* Update the rcv time and perform idle reduction possibly */
13524 		if  (tp->t_idle_reduce &&
13525 		     (tp->snd_max == tp->snd_una) &&
13526 		     (TICKS_2_USEC(ticks - tp->t_rcvtime) >= tp->t_rxtcur)) {
13527 			counter_u64_add(rack_input_idle_reduces, 1);
13528 			rack_cc_after_idle(rack, tp);
13529 		}
13530 		tp->t_rcvtime = ticks;
13531 		/* Now what about ECN? */
13532 		if (tcp_ecn_input_segment(tp, ae->flags, ae->codepoint))
13533 			rack_cong_signal(tp, CC_ECN, ae->ack, __LINE__);
13534 #ifdef TCP_ACCOUNTING
13535 		/* Count for the specific type of ack in */
13536 		counter_u64_add(tcp_cnt_counters[ae->ack_val_set], 1);
13537 		if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
13538 			tp->tcp_cnt_counters[ae->ack_val_set]++;
13539 		}
13540 #endif
13541 		/*
13542 		 * Note how we could move up these in the determination
13543 		 * above, but we don't so that way the timestamp checks (and ECN)
13544 		 * is done first before we do any processing on the ACK.
13545 		 * The non-compressed path through the code has this
13546 		 * weakness (noted by @jtl) that it actually does some
13547 		 * processing before verifying the timestamp information.
13548 		 * We don't take that path here which is why we set
13549 		 * the ack_val_set first, do the timestamp and ecn
13550 		 * processing, and then look at what we have setup.
13551 		 */
13552 		if (ae->ack_val_set == ACK_BEHIND) {
13553 			/*
13554 			 * Case B flag reordering, if window is not closed
13555 			 * or it could be a keep-alive or persists
13556 			 */
13557 			if (SEQ_LT(ae->ack, tp->snd_una) && (sbspace(&so->so_rcv) > segsiz)) {
13558 				rack->r_ctl.rc_reorder_ts = tcp_tv_to_usectick(&rack->r_ctl.act_rcv_time);
13559 			}
13560 		} else if (ae->ack_val_set == ACK_DUPACK) {
13561 			/* Case D */
13562 			rack_strike_dupack(rack);
13563 		} else if (ae->ack_val_set == ACK_RWND) {
13564 			/* Case C */
13565 			if ((ae->flags & TSTMP_LRO) || (ae->flags & TSTMP_HDWR)) {
13566 				ts.tv_sec = ae->timestamp / 1000000000;
13567 				ts.tv_nsec = ae->timestamp % 1000000000;
13568 				rack->r_ctl.act_rcv_time.tv_sec = ts.tv_sec;
13569 				rack->r_ctl.act_rcv_time.tv_usec = ts.tv_nsec/1000;
13570 			} else {
13571 				rack->r_ctl.act_rcv_time = *tv;
13572 			}
13573 			if (rack->forced_ack) {
13574 				rack_handle_probe_response(rack, tiwin,
13575 							   tcp_tv_to_usectick(&rack->r_ctl.act_rcv_time));
13576 			}
13577 #ifdef TCP_ACCOUNTING
13578 			win_up_req = 1;
13579 #endif
13580 			win_upd_ack = ae->ack;
13581 			win_seq = ae->seq;
13582 			the_win = tiwin;
13583 			rack_do_win_updates(tp, rack, the_win, win_seq, win_upd_ack, cts, high_seq);
13584 		} else {
13585 			/* Case A */
13586 			if (SEQ_GT(ae->ack, tp->snd_max)) {
13587 				/*
13588 				 * We just send an ack since the incoming
13589 				 * ack is beyond the largest seq we sent.
13590 				 */
13591 				if ((tp->t_flags & TF_ACKNOW) == 0) {
13592 					ctf_ack_war_checks(tp, &rack->r_ctl.challenge_ack_ts, &rack->r_ctl.challenge_ack_cnt);
13593 					if (tp->t_flags && TF_ACKNOW)
13594 						rack->r_wanted_output = 1;
13595 				}
13596 			} else {
13597 				nsegs++;
13598 				/* If the window changed setup to update */
13599 				if (tiwin != tp->snd_wnd) {
13600 					win_upd_ack = ae->ack;
13601 					win_seq = ae->seq;
13602 					the_win = tiwin;
13603 					rack_do_win_updates(tp, rack, the_win, win_seq, win_upd_ack, cts, high_seq);
13604 				}
13605 #ifdef TCP_ACCOUNTING
13606 				/* Account for the acks */
13607 				if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
13608 					tp->tcp_cnt_counters[CNT_OF_ACKS_IN] += (((ae->ack - high_seq) + segsiz - 1) / segsiz);
13609 				}
13610 				counter_u64_add(tcp_cnt_counters[CNT_OF_ACKS_IN],
13611 						(((ae->ack - high_seq) + segsiz - 1) / segsiz));
13612 #endif
13613 				high_seq = ae->ack;
13614 				if (rack_verbose_logging && (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF)) {
13615 					union tcp_log_stackspecific log;
13616 					struct timeval tv;
13617 
13618 					memset(&log.u_bbr, 0, sizeof(log.u_bbr));
13619 					log.u_bbr.timeStamp = tcp_get_usecs(&tv);
13620 					log.u_bbr.flex1 = high_seq;
13621 					log.u_bbr.flex2 = rack->r_ctl.roundends;
13622 					log.u_bbr.flex3 = rack->r_ctl.current_round;
13623 					log.u_bbr.rttProp = (uint64_t)CC_ALGO(tp)->newround;
13624 					log.u_bbr.flex8 = 8;
13625 					tcp_log_event_(tp, NULL, NULL, NULL, BBR_LOG_CWND, 0,
13626 						       0, &log, false, NULL, NULL, 0, &tv);
13627 				}
13628 				/*
13629 				 * The draft (v3) calls for us to use SEQ_GEQ, but that
13630 				 * causes issues when we are just going app limited. Lets
13631 				 * instead use SEQ_GT <or> where its equal but more data
13632 				 * is outstanding.
13633 				 */
13634 				if ((SEQ_GT(high_seq, rack->r_ctl.roundends)) ||
13635 				    ((high_seq == rack->r_ctl.roundends) &&
13636 				     SEQ_GT(tp->snd_max, tp->snd_una))) {
13637 					rack->r_ctl.current_round++;
13638 					rack->r_ctl.roundends = tp->snd_max;
13639 					if (CC_ALGO(tp)->newround != NULL) {
13640 						CC_ALGO(tp)->newround(tp->ccv, rack->r_ctl.current_round);
13641 					}
13642 				}
13643 				/* Setup our act_rcv_time */
13644 				if ((ae->flags & TSTMP_LRO) || (ae->flags & TSTMP_HDWR)) {
13645 					ts.tv_sec = ae->timestamp / 1000000000;
13646 					ts.tv_nsec = ae->timestamp % 1000000000;
13647 					rack->r_ctl.act_rcv_time.tv_sec = ts.tv_sec;
13648 					rack->r_ctl.act_rcv_time.tv_usec = ts.tv_nsec/1000;
13649 				} else {
13650 					rack->r_ctl.act_rcv_time = *tv;
13651 				}
13652 				rack_process_to_cumack(tp, rack, ae->ack, cts, to);
13653 				if (rack->rc_dsack_round_seen) {
13654 					/* Is the dsack round over? */
13655 					if (SEQ_GEQ(ae->ack, rack->r_ctl.dsack_round_end)) {
13656 						/* Yes it is */
13657 						rack->rc_dsack_round_seen = 0;
13658 						rack_log_dsack_event(rack, 3, __LINE__, 0, 0);
13659 					}
13660 				}
13661 			}
13662 		}
13663 		/* And lets be sure to commit the rtt measurements for this ack */
13664 		tcp_rack_xmit_timer_commit(rack, tp);
13665 #ifdef TCP_ACCOUNTING
13666 		rdstc = get_cyclecount();
13667 		if (rdstc > ts_val) {
13668 			counter_u64_add(tcp_proc_time[ae->ack_val_set] , (rdstc - ts_val));
13669 			if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
13670 				tp->tcp_proc_time[ae->ack_val_set] += (rdstc - ts_val);
13671 				if (ae->ack_val_set == ACK_CUMACK)
13672 					tp->tcp_proc_time[CYC_HANDLE_MAP] += (rdstc - ts_val);
13673 			}
13674 		}
13675 #endif
13676 	}
13677 #ifdef TCP_ACCOUNTING
13678 	ts_val = get_cyclecount();
13679 #endif
13680 	/* Tend to any collapsed window */
13681 	if (SEQ_GT(tp->snd_max, high_seq) && (tp->snd_wnd < (tp->snd_max - high_seq))) {
13682 		/* The peer collapsed the window */
13683 		rack_collapsed_window(rack, (tp->snd_max - high_seq), __LINE__);
13684 	} else if (rack->rc_has_collapsed)
13685 		rack_un_collapse_window(rack, __LINE__);
13686 	if ((rack->r_collapse_point_valid) &&
13687 	    (SEQ_GT(high_seq, rack->r_ctl.high_collapse_point)))
13688 		rack->r_collapse_point_valid = 0;
13689 	acked_amount = acked = (high_seq - tp->snd_una);
13690 	if (acked) {
13691 		/*
13692 		 * Clear the probe not answered flag
13693 		 * since cum-ack moved forward.
13694 		 */
13695 		rack->probe_not_answered = 0;
13696 		if (rack->sack_attack_disable == 0)
13697 			rack_do_decay(rack);
13698 		if (acked >= segsiz) {
13699 			/*
13700 			 * You only get credit for
13701 			 * MSS and greater (and you get extra
13702 			 * credit for larger cum-ack moves).
13703 			 */
13704 			int ac;
13705 
13706 			ac = acked / segsiz;
13707 			rack->r_ctl.ack_count += ac;
13708 			counter_u64_add(rack_ack_total, ac);
13709 		}
13710 		if (rack->r_ctl.ack_count > 0xfff00000) {
13711 			/*
13712 			 * reduce the number to keep us under
13713 			 * a uint32_t.
13714 			 */
13715 			rack->r_ctl.ack_count /= 2;
13716 			rack->r_ctl.sack_count /= 2;
13717 		}
13718 		if (tp->t_flags & TF_NEEDSYN) {
13719 			/*
13720 			 * T/TCP: Connection was half-synchronized, and our SYN has
13721 			 * been ACK'd (so connection is now fully synchronized).  Go
13722 			 * to non-starred state, increment snd_una for ACK of SYN,
13723 			 * and check if we can do window scaling.
13724 			 */
13725 			tp->t_flags &= ~TF_NEEDSYN;
13726 			tp->snd_una++;
13727 			acked_amount = acked = (high_seq - tp->snd_una);
13728 		}
13729 		if (acked > sbavail(&so->so_snd))
13730 			acked_amount = sbavail(&so->so_snd);
13731 #ifdef NETFLIX_EXP_DETECTION
13732 		/*
13733 		 * We only care on a cum-ack move if we are in a sack-disabled
13734 		 * state. We have already added in to the ack_count, and we never
13735 		 * would disable on a cum-ack move, so we only care to do the
13736 		 * detection if it may "undo" it, i.e. we were in disabled already.
13737 		 */
13738 		if (rack->sack_attack_disable)
13739 			rack_do_detection(tp, rack, acked_amount, segsiz);
13740 #endif
13741 		if (IN_FASTRECOVERY(tp->t_flags) &&
13742 		    (rack->rack_no_prr == 0))
13743 			rack_update_prr(tp, rack, acked_amount, high_seq);
13744 		if (IN_RECOVERY(tp->t_flags)) {
13745 			if (SEQ_LT(high_seq, tp->snd_recover) &&
13746 			    (SEQ_LT(high_seq, tp->snd_max))) {
13747 				tcp_rack_partialack(tp);
13748 			} else {
13749 				rack_post_recovery(tp, high_seq);
13750 				recovery = 1;
13751 			}
13752 		}
13753 		/* Handle the rack-log-ack part (sendmap) */
13754 		if ((sbused(&so->so_snd) == 0) &&
13755 		    (acked > acked_amount) &&
13756 		    (tp->t_state >= TCPS_FIN_WAIT_1) &&
13757 		    (tp->t_flags & TF_SENTFIN)) {
13758 			/*
13759 			 * We must be sure our fin
13760 			 * was sent and acked (we can be
13761 			 * in FIN_WAIT_1 without having
13762 			 * sent the fin).
13763 			 */
13764 			ourfinisacked = 1;
13765 			/*
13766 			 * Lets make sure snd_una is updated
13767 			 * since most likely acked_amount = 0 (it
13768 			 * should be).
13769 			 */
13770 			tp->snd_una = high_seq;
13771 		}
13772 		/* Did we make a RTO error? */
13773 		if ((tp->t_flags & TF_PREVVALID) &&
13774 		    ((tp->t_flags & TF_RCVD_TSTMP) == 0)) {
13775 			tp->t_flags &= ~TF_PREVVALID;
13776 			if (tp->t_rxtshift == 1 &&
13777 			    (int)(ticks - tp->t_badrxtwin) < 0)
13778 				rack_cong_signal(tp, CC_RTO_ERR, high_seq, __LINE__);
13779 		}
13780 		/* Handle the data in the socket buffer */
13781 		KMOD_TCPSTAT_ADD(tcps_rcvackpack, 1);
13782 		KMOD_TCPSTAT_ADD(tcps_rcvackbyte, acked);
13783 		if (acked_amount > 0) {
13784 			struct mbuf *mfree;
13785 
13786 			rack_ack_received(tp, rack, high_seq, nsegs, CC_ACK, recovery);
13787 			SOCKBUF_LOCK(&so->so_snd);
13788 			mfree = sbcut_locked(&so->so_snd, acked_amount);
13789 			tp->snd_una = high_seq;
13790 			/* Note we want to hold the sb lock through the sendmap adjust */
13791 			rack_adjust_sendmap(rack, &so->so_snd, tp->snd_una);
13792 			/* Wake up the socket if we have room to write more */
13793 			rack_log_wakeup(tp,rack, &so->so_snd, acked, 2);
13794 			sowwakeup_locked(so);
13795 			m_freem(mfree);
13796 		}
13797 		/* update progress */
13798 		tp->t_acktime = ticks;
13799 		rack_log_progress_event(rack, tp, tp->t_acktime,
13800 					PROGRESS_UPDATE, __LINE__);
13801 		/* Clear out shifts and such */
13802 		tp->t_rxtshift = 0;
13803 		RACK_TCPT_RANGESET(tp->t_rxtcur, RACK_REXMTVAL(tp),
13804 				   rack_rto_min, rack_rto_max, rack->r_ctl.timer_slop);
13805 		rack->rc_tlp_in_progress = 0;
13806 		rack->r_ctl.rc_tlp_cnt_out = 0;
13807 		/* Send recover and snd_nxt must be dragged along */
13808 		if (SEQ_GT(tp->snd_una, tp->snd_recover))
13809 			tp->snd_recover = tp->snd_una;
13810 		if (SEQ_LT(tp->snd_nxt, tp->snd_una))
13811 			tp->snd_nxt = tp->snd_una;
13812 		/*
13813 		 * If the RXT timer is running we want to
13814 		 * stop it, so we can restart a TLP (or new RXT).
13815 		 */
13816 		if (rack->r_ctl.rc_hpts_flags & PACE_TMR_RXT)
13817 			rack_timer_cancel(tp, rack, rack->r_ctl.rc_rcvtime, __LINE__);
13818 #ifdef NETFLIX_HTTP_LOGGING
13819 		tcp_http_check_for_comp(rack->rc_tp, high_seq);
13820 #endif
13821 		tp->snd_wl2 = high_seq;
13822 		tp->t_dupacks = 0;
13823 		if (under_pacing &&
13824 		    (rack->use_fixed_rate == 0) &&
13825 		    (rack->in_probe_rtt == 0) &&
13826 		    rack->rc_gp_dyn_mul &&
13827 		    rack->rc_always_pace) {
13828 			/* Check if we are dragging bottom */
13829 			rack_check_bottom_drag(tp, rack, so, acked);
13830 		}
13831 		if (tp->snd_una == tp->snd_max) {
13832 			tp->t_flags &= ~TF_PREVVALID;
13833 			rack->r_ctl.retran_during_recovery = 0;
13834 			rack->r_ctl.dsack_byte_cnt = 0;
13835 			rack->r_ctl.rc_went_idle_time = tcp_get_usecs(NULL);
13836 			if (rack->r_ctl.rc_went_idle_time == 0)
13837 				rack->r_ctl.rc_went_idle_time = 1;
13838 			rack_log_progress_event(rack, tp, 0, PROGRESS_CLEAR, __LINE__);
13839 			if (sbavail(&tp->t_inpcb->inp_socket->so_snd) == 0)
13840 				tp->t_acktime = 0;
13841 			/* Set so we might enter persists... */
13842 			rack->r_wanted_output = 1;
13843 			rack_timer_cancel(tp, rack, rack->r_ctl.rc_rcvtime, __LINE__);
13844 			sack_filter_clear(&rack->r_ctl.rack_sf, tp->snd_una);
13845 			if ((tp->t_state >= TCPS_FIN_WAIT_1) &&
13846 			    (sbavail(&so->so_snd) == 0) &&
13847 			    (tp->t_flags2 & TF2_DROP_AF_DATA)) {
13848 				/*
13849 				 * The socket was gone and the
13850 				 * peer sent data (not now in the past), time to
13851 				 * reset him.
13852 				 */
13853 				rack_timer_cancel(tp, rack, rack->r_ctl.rc_rcvtime, __LINE__);
13854 				/* tcp_close will kill the inp pre-log the Reset */
13855 				tcp_log_end_status(tp, TCP_EI_STATUS_SERVER_RST);
13856 #ifdef TCP_ACCOUNTING
13857 				rdstc = get_cyclecount();
13858 				if (rdstc > ts_val) {
13859 					counter_u64_add(tcp_proc_time[ACK_CUMACK] , (rdstc - ts_val));
13860 					if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
13861 						tp->tcp_proc_time[ACK_CUMACK] += (rdstc - ts_val);
13862 						tp->tcp_proc_time[CYC_HANDLE_ACK] += (rdstc - ts_val);
13863 					}
13864 				}
13865 #endif
13866 				m_freem(m);
13867 				tp = tcp_close(tp);
13868 				if (tp == NULL) {
13869 #ifdef TCP_ACCOUNTING
13870 					sched_unpin();
13871 #endif
13872 					return (1);
13873 				}
13874 				/*
13875 				 * We would normally do drop-with-reset which would
13876 				 * send back a reset. We can't since we don't have
13877 				 * all the needed bits. Instead lets arrange for
13878 				 * a call to tcp_output(). That way since we
13879 				 * are in the closed state we will generate a reset.
13880 				 *
13881 				 * Note if tcp_accounting is on we don't unpin since
13882 				 * we do that after the goto label.
13883 				 */
13884 				goto send_out_a_rst;
13885 			}
13886 			if ((sbused(&so->so_snd) == 0) &&
13887 			    (tp->t_state >= TCPS_FIN_WAIT_1) &&
13888 			    (tp->t_flags & TF_SENTFIN)) {
13889 				/*
13890 				 * If we can't receive any more data, then closing user can
13891 				 * proceed. Starting the timer is contrary to the
13892 				 * specification, but if we don't get a FIN we'll hang
13893 				 * forever.
13894 				 *
13895 				 */
13896 				if (so->so_rcv.sb_state & SBS_CANTRCVMORE) {
13897 					soisdisconnected(so);
13898 					tcp_timer_activate(tp, TT_2MSL,
13899 							   (tcp_fast_finwait2_recycle ?
13900 							    tcp_finwait2_timeout :
13901 							    TP_MAXIDLE(tp)));
13902 				}
13903 				if (ourfinisacked == 0) {
13904 					/*
13905 					 * We don't change to fin-wait-2 if we have our fin acked
13906 					 * which means we are probably in TCPS_CLOSING.
13907 					 */
13908 					tcp_state_change(tp, TCPS_FIN_WAIT_2);
13909 				}
13910 			}
13911 		}
13912 		/* Wake up the socket if we have room to write more */
13913 		if (sbavail(&so->so_snd)) {
13914 			rack->r_wanted_output = 1;
13915 			if (ctf_progress_timeout_check(tp, true)) {
13916 				rack_log_progress_event((struct tcp_rack *)tp->t_fb_ptr,
13917 							tp, tick, PROGRESS_DROP, __LINE__);
13918 				/*
13919 				 * We cheat here and don't send a RST, we should send one
13920 				 * when the pacer drops the connection.
13921 				 */
13922 #ifdef TCP_ACCOUNTING
13923 				rdstc = get_cyclecount();
13924 				if (rdstc > ts_val) {
13925 					counter_u64_add(tcp_proc_time[ACK_CUMACK] , (rdstc - ts_val));
13926 					if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
13927 						tp->tcp_proc_time[ACK_CUMACK] += (rdstc - ts_val);
13928 						tp->tcp_proc_time[CYC_HANDLE_ACK] += (rdstc - ts_val);
13929 					}
13930 				}
13931 				sched_unpin();
13932 #endif
13933 				(void)tcp_drop(tp, ETIMEDOUT);
13934 				m_freem(m);
13935 				return (1);
13936 			}
13937 		}
13938 		if (ourfinisacked) {
13939 			switch(tp->t_state) {
13940 			case TCPS_CLOSING:
13941 #ifdef TCP_ACCOUNTING
13942 				rdstc = get_cyclecount();
13943 				if (rdstc > ts_val) {
13944 					counter_u64_add(tcp_proc_time[ACK_CUMACK] ,
13945 							(rdstc - ts_val));
13946 					if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
13947 						tp->tcp_proc_time[ACK_CUMACK] += (rdstc - ts_val);
13948 						tp->tcp_proc_time[CYC_HANDLE_ACK] += (rdstc - ts_val);
13949 					}
13950 				}
13951 				sched_unpin();
13952 #endif
13953 				tcp_twstart(tp);
13954 				m_freem(m);
13955 				return (1);
13956 				break;
13957 			case TCPS_LAST_ACK:
13958 #ifdef TCP_ACCOUNTING
13959 				rdstc = get_cyclecount();
13960 				if (rdstc > ts_val) {
13961 					counter_u64_add(tcp_proc_time[ACK_CUMACK] ,
13962 							(rdstc - ts_val));
13963 					if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
13964 						tp->tcp_proc_time[ACK_CUMACK] += (rdstc - ts_val);
13965 						tp->tcp_proc_time[CYC_HANDLE_ACK] += (rdstc - ts_val);
13966 					}
13967 				}
13968 				sched_unpin();
13969 #endif
13970 				tp = tcp_close(tp);
13971 				ctf_do_drop(m, tp);
13972 				return (1);
13973 				break;
13974 			case TCPS_FIN_WAIT_1:
13975 #ifdef TCP_ACCOUNTING
13976 				rdstc = get_cyclecount();
13977 				if (rdstc > ts_val) {
13978 					counter_u64_add(tcp_proc_time[ACK_CUMACK] ,
13979 							(rdstc - ts_val));
13980 					if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
13981 						tp->tcp_proc_time[ACK_CUMACK] += (rdstc - ts_val);
13982 						tp->tcp_proc_time[CYC_HANDLE_ACK] += (rdstc - ts_val);
13983 					}
13984 				}
13985 #endif
13986 				if (so->so_rcv.sb_state & SBS_CANTRCVMORE) {
13987 					soisdisconnected(so);
13988 					tcp_timer_activate(tp, TT_2MSL,
13989 							   (tcp_fast_finwait2_recycle ?
13990 							    tcp_finwait2_timeout :
13991 							    TP_MAXIDLE(tp)));
13992 				}
13993 				tcp_state_change(tp, TCPS_FIN_WAIT_2);
13994 				break;
13995 			default:
13996 				break;
13997 			}
13998 		}
13999 		if (rack->r_fast_output) {
14000 			/*
14001 			 * We re doing fast output.. can we expand that?
14002 			 */
14003 			rack_gain_for_fastoutput(rack, tp, so, acked_amount);
14004 		}
14005 #ifdef TCP_ACCOUNTING
14006 		rdstc = get_cyclecount();
14007 		if (rdstc > ts_val) {
14008 			counter_u64_add(tcp_proc_time[ACK_CUMACK] , (rdstc - ts_val));
14009 			if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
14010 				tp->tcp_proc_time[ACK_CUMACK] += (rdstc - ts_val);
14011 				tp->tcp_proc_time[CYC_HANDLE_ACK] += (rdstc - ts_val);
14012 			}
14013 		}
14014 
14015 	} else if (win_up_req) {
14016 		rdstc = get_cyclecount();
14017 		if (rdstc > ts_val) {
14018 			counter_u64_add(tcp_proc_time[ACK_RWND] , (rdstc - ts_val));
14019 			if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
14020 				tp->tcp_proc_time[ACK_RWND] += (rdstc - ts_val);
14021 			}
14022 		}
14023 #endif
14024 	}
14025 	/* Now is there a next packet, if so we are done */
14026 	m_freem(m);
14027 	did_out = 0;
14028 	if (nxt_pkt) {
14029 #ifdef TCP_ACCOUNTING
14030 		sched_unpin();
14031 #endif
14032 		rack_log_doseg_done(rack, cts, nxt_pkt, did_out, 5, nsegs);
14033 		return (0);
14034 	}
14035 	rack_handle_might_revert(tp, rack);
14036 	ctf_calc_rwin(so, tp);
14037 	if ((rack->r_wanted_output != 0) || (rack->r_fast_output != 0)) {
14038 	send_out_a_rst:
14039 		if (tcp_output(tp) < 0) {
14040 #ifdef TCP_ACCOUNTING
14041 			sched_unpin();
14042 #endif
14043 			return (1);
14044 		}
14045 		did_out = 1;
14046 	}
14047 	rack_free_trim(rack);
14048 #ifdef TCP_ACCOUNTING
14049 	sched_unpin();
14050 #endif
14051 	rack_timer_audit(tp, rack, &so->so_snd);
14052 	rack_log_doseg_done(rack, cts, nxt_pkt, did_out, 6, nsegs);
14053 	return (0);
14054 }
14055 
14056 
14057 static int
14058 rack_do_segment_nounlock(struct mbuf *m, struct tcphdr *th, struct socket *so,
14059     struct tcpcb *tp, int32_t drop_hdrlen, int32_t tlen, uint8_t iptos,
14060     int32_t nxt_pkt, struct timeval *tv)
14061 {
14062 #ifdef TCP_ACCOUNTING
14063 	uint64_t ts_val;
14064 #endif
14065 	int32_t thflags, retval, did_out = 0;
14066 	int32_t way_out = 0;
14067 	/*
14068 	 * cts - is the current time from tv (caller gets ts) in microseconds.
14069 	 * ms_cts - is the current time from tv in milliseconds.
14070 	 * us_cts - is the time that LRO or hardware actually got the packet in microseconds.
14071 	 */
14072 	uint32_t cts, us_cts, ms_cts;
14073 	uint32_t tiwin, high_seq;
14074 	struct timespec ts;
14075 	struct tcpopt to;
14076 	struct tcp_rack *rack;
14077 	struct rack_sendmap *rsm;
14078 	int32_t prev_state = 0;
14079 #ifdef TCP_ACCOUNTING
14080 	int ack_val_set = 0xf;
14081 #endif
14082 	int nsegs;
14083 	/*
14084 	 * tv passed from common code is from either M_TSTMP_LRO or
14085 	 * tcp_get_usecs() if no LRO m_pkthdr timestamp is present.
14086 	 */
14087 	rack = (struct tcp_rack *)tp->t_fb_ptr;
14088 	if (m->m_flags & M_ACKCMP) {
14089 		/*
14090 		 * All compressed ack's are ack's by definition so
14091 		 * remove any ack required flag and then do the processing.
14092 		 */
14093 		rack->rc_ack_required = 0;
14094 		return (rack_do_compressed_ack_processing(tp, so, m, nxt_pkt, tv));
14095 	}
14096 	if (m->m_flags & M_ACKCMP) {
14097 		panic("Impossible reach m has ackcmp? m:%p tp:%p", m, tp);
14098 	}
14099 	cts = tcp_tv_to_usectick(tv);
14100 	ms_cts =  tcp_tv_to_mssectick(tv);
14101 	nsegs = m->m_pkthdr.lro_nsegs;
14102 	counter_u64_add(rack_proc_non_comp_ack, 1);
14103 	thflags = tcp_get_flags(th);
14104 #ifdef TCP_ACCOUNTING
14105 	sched_pin();
14106 	if (thflags & TH_ACK)
14107 		ts_val = get_cyclecount();
14108 #endif
14109 	if ((m->m_flags & M_TSTMP) ||
14110 	    (m->m_flags & M_TSTMP_LRO)) {
14111 		mbuf_tstmp2timespec(m, &ts);
14112 		rack->r_ctl.act_rcv_time.tv_sec = ts.tv_sec;
14113 		rack->r_ctl.act_rcv_time.tv_usec = ts.tv_nsec/1000;
14114 	} else
14115 		rack->r_ctl.act_rcv_time = *tv;
14116 	kern_prefetch(rack, &prev_state);
14117 	prev_state = 0;
14118 	/*
14119 	 * Unscale the window into a 32-bit value. For the SYN_SENT state
14120 	 * the scale is zero.
14121 	 */
14122 	tiwin = th->th_win << tp->snd_scale;
14123 #ifdef TCP_ACCOUNTING
14124 	if (thflags & TH_ACK) {
14125 		/*
14126 		 * We have a tradeoff here. We can either do what we are
14127 		 * doing i.e. pinning to this CPU and then doing the accounting
14128 		 * <or> we could do a critical enter, setup the rdtsc and cpu
14129 		 * as in below, and then validate we are on the same CPU on
14130 		 * exit. I have choosen to not do the critical enter since
14131 		 * that often will gain you a context switch, and instead lock
14132 		 * us (line above this if) to the same CPU with sched_pin(). This
14133 		 * means we may be context switched out for a higher priority
14134 		 * interupt but we won't be moved to another CPU.
14135 		 *
14136 		 * If this occurs (which it won't very often since we most likely
14137 		 * are running this code in interupt context and only a higher
14138 		 * priority will bump us ... clock?) we will falsely add in
14139 		 * to the time the interupt processing time plus the ack processing
14140 		 * time. This is ok since its a rare event.
14141 		 */
14142 		ack_val_set = tcp_do_ack_accounting(tp, th, &to, tiwin,
14143 						    ctf_fixed_maxseg(tp));
14144 	}
14145 #endif
14146 	/*
14147 	 * Parse options on any incoming segment.
14148 	 */
14149 	memset(&to, 0, sizeof(to));
14150 	tcp_dooptions(&to, (u_char *)(th + 1),
14151 	    (th->th_off << 2) - sizeof(struct tcphdr),
14152 	    (thflags & TH_SYN) ? TO_SYN : 0);
14153 	NET_EPOCH_ASSERT();
14154 	INP_WLOCK_ASSERT(tp->t_inpcb);
14155 	KASSERT(tp->t_state > TCPS_LISTEN, ("%s: TCPS_LISTEN",
14156 	    __func__));
14157 	KASSERT(tp->t_state != TCPS_TIME_WAIT, ("%s: TCPS_TIME_WAIT",
14158 	    __func__));
14159 	if ((tp->t_state >= TCPS_FIN_WAIT_1) &&
14160 	    (tp->t_flags & TF_GPUTINPROG)) {
14161 		/*
14162 		 * We have a goodput in progress
14163 		 * and we have entered a late state.
14164 		 * Do we have enough data in the sb
14165 		 * to handle the GPUT request?
14166 		 */
14167 		uint32_t bytes;
14168 
14169 		bytes = tp->gput_ack - tp->gput_seq;
14170 		if (SEQ_GT(tp->gput_seq, tp->snd_una))
14171 			bytes += tp->gput_seq - tp->snd_una;
14172 		if (bytes > sbavail(&tp->t_inpcb->inp_socket->so_snd)) {
14173 			/*
14174 			 * There are not enough bytes in the socket
14175 			 * buffer that have been sent to cover this
14176 			 * measurement. Cancel it.
14177 			 */
14178 			rack_log_pacing_delay_calc(rack, (tp->gput_ack - tp->gput_seq) /*flex2*/,
14179 						   rack->r_ctl.rc_gp_srtt /*flex1*/,
14180 						   tp->gput_seq,
14181 						   0, 0, 18, __LINE__, NULL, 0);
14182 			tp->t_flags &= ~TF_GPUTINPROG;
14183 		}
14184 	}
14185 	high_seq = th->th_ack;
14186 	if (tp->t_logstate != TCP_LOG_STATE_OFF) {
14187 		union tcp_log_stackspecific log;
14188 		struct timeval ltv;
14189 #ifdef NETFLIX_HTTP_LOGGING
14190 		struct http_sendfile_track *http_req;
14191 
14192 		if (SEQ_GT(th->th_ack, tp->snd_una)) {
14193 			http_req = tcp_http_find_req_for_seq(tp, (th->th_ack-1));
14194 		} else {
14195 			http_req = tcp_http_find_req_for_seq(tp, th->th_ack);
14196 		}
14197 #endif
14198 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
14199 		log.u_bbr.inhpts = tcp_in_hpts(rack->rc_inp);
14200 		if (rack->rack_no_prr == 0)
14201 			log.u_bbr.flex1 = rack->r_ctl.rc_prr_sndcnt;
14202 		else
14203 			log.u_bbr.flex1 = 0;
14204 		log.u_bbr.use_lt_bw = rack->r_ent_rec_ns;
14205 		log.u_bbr.use_lt_bw <<= 1;
14206 		log.u_bbr.use_lt_bw |= rack->r_might_revert;
14207 		log.u_bbr.flex2 = rack->r_ctl.rc_num_maps_alloced;
14208 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
14209 		log.u_bbr.pkts_out = rack->rc_tp->t_maxseg;
14210 		log.u_bbr.flex3 = m->m_flags;
14211 		log.u_bbr.flex4 = rack->r_ctl.rc_hpts_flags;
14212 		log.u_bbr.lost = thflags;
14213 		log.u_bbr.pacing_gain = 0x1;
14214 #ifdef TCP_ACCOUNTING
14215 		log.u_bbr.cwnd_gain = ack_val_set;
14216 #endif
14217 		log.u_bbr.flex7 = 2;
14218 		if (m->m_flags & M_TSTMP) {
14219 			/* Record the hardware timestamp if present */
14220 			mbuf_tstmp2timespec(m, &ts);
14221 			ltv.tv_sec = ts.tv_sec;
14222 			ltv.tv_usec = ts.tv_nsec / 1000;
14223 			log.u_bbr.lt_epoch = tcp_tv_to_usectick(&ltv);
14224 		} else if (m->m_flags & M_TSTMP_LRO) {
14225 			/* Record the LRO the arrival timestamp */
14226 			mbuf_tstmp2timespec(m, &ts);
14227 			ltv.tv_sec = ts.tv_sec;
14228 			ltv.tv_usec = ts.tv_nsec / 1000;
14229 			log.u_bbr.flex5 = tcp_tv_to_usectick(&ltv);
14230 		}
14231 		log.u_bbr.timeStamp = tcp_get_usecs(&ltv);
14232 		/* Log the rcv time */
14233 		log.u_bbr.delRate = m->m_pkthdr.rcv_tstmp;
14234 #ifdef NETFLIX_HTTP_LOGGING
14235 		log.u_bbr.applimited = tp->t_http_closed;
14236 		log.u_bbr.applimited <<= 8;
14237 		log.u_bbr.applimited |= tp->t_http_open;
14238 		log.u_bbr.applimited <<= 8;
14239 		log.u_bbr.applimited |= tp->t_http_req;
14240 		if (http_req) {
14241 			/* Copy out any client req info */
14242 			/* seconds */
14243 			log.u_bbr.pkt_epoch = (http_req->localtime / HPTS_USEC_IN_SEC);
14244 			/* useconds */
14245 			log.u_bbr.delivered = (http_req->localtime % HPTS_USEC_IN_SEC);
14246 			log.u_bbr.rttProp = http_req->timestamp;
14247 			log.u_bbr.cur_del_rate = http_req->start;
14248 			if (http_req->flags & TCP_HTTP_TRACK_FLG_OPEN) {
14249 				log.u_bbr.flex8 |= 1;
14250 			} else {
14251 				log.u_bbr.flex8 |= 2;
14252 				log.u_bbr.bw_inuse = http_req->end;
14253 			}
14254 			log.u_bbr.flex6 = http_req->start_seq;
14255 			if (http_req->flags & TCP_HTTP_TRACK_FLG_COMP) {
14256 				log.u_bbr.flex8 |= 4;
14257 				log.u_bbr.epoch = http_req->end_seq;
14258 			}
14259 		}
14260 #endif
14261 		TCP_LOG_EVENTP(tp, th, &so->so_rcv, &so->so_snd, TCP_LOG_IN, 0,
14262 		    tlen, &log, true, &ltv);
14263 	}
14264 	/* Remove ack required flag if set, we have one  */
14265 	if (thflags & TH_ACK)
14266 		rack->rc_ack_required = 0;
14267 	if ((thflags & TH_SYN) && (thflags & TH_FIN) && V_drop_synfin) {
14268 		way_out = 4;
14269 		retval = 0;
14270 		m_freem(m);
14271 		goto done_with_input;
14272 	}
14273 	/*
14274 	 * If a segment with the ACK-bit set arrives in the SYN-SENT state
14275 	 * check SEQ.ACK first as described on page 66 of RFC 793, section 3.9.
14276 	 */
14277 	if ((tp->t_state == TCPS_SYN_SENT) && (thflags & TH_ACK) &&
14278 	    (SEQ_LEQ(th->th_ack, tp->iss) || SEQ_GT(th->th_ack, tp->snd_max))) {
14279 		tcp_log_end_status(tp, TCP_EI_STATUS_RST_IN_FRONT);
14280 		ctf_do_dropwithreset(m, tp, th, BANDLIM_RST_OPENPORT, tlen);
14281 #ifdef TCP_ACCOUNTING
14282 		sched_unpin();
14283 #endif
14284 		return (1);
14285 	}
14286 	/*
14287 	 * If timestamps were negotiated during SYN/ACK and a
14288 	 * segment without a timestamp is received, silently drop
14289 	 * the segment, unless it is a RST segment or missing timestamps are
14290 	 * tolerated.
14291 	 * See section 3.2 of RFC 7323.
14292 	 */
14293 	if ((tp->t_flags & TF_RCVD_TSTMP) && !(to.to_flags & TOF_TS) &&
14294 	    ((thflags & TH_RST) == 0) && (V_tcp_tolerate_missing_ts == 0)) {
14295 		way_out = 5;
14296 		retval = 0;
14297 		m_freem(m);
14298 		goto done_with_input;
14299 	}
14300 
14301 	/*
14302 	 * Segment received on connection. Reset idle time and keep-alive
14303 	 * timer. XXX: This should be done after segment validation to
14304 	 * ignore broken/spoofed segs.
14305 	 */
14306 	if  (tp->t_idle_reduce &&
14307 	     (tp->snd_max == tp->snd_una) &&
14308 	     (TICKS_2_USEC(ticks - tp->t_rcvtime) >= tp->t_rxtcur)) {
14309 		counter_u64_add(rack_input_idle_reduces, 1);
14310 		rack_cc_after_idle(rack, tp);
14311 	}
14312 	tp->t_rcvtime = ticks;
14313 #ifdef STATS
14314 	stats_voi_update_abs_ulong(tp->t_stats, VOI_TCP_FRWIN, tiwin);
14315 #endif
14316 	if (tiwin > rack->r_ctl.rc_high_rwnd)
14317 		rack->r_ctl.rc_high_rwnd = tiwin;
14318 	/*
14319 	 * TCP ECN processing. XXXJTL: If we ever use ECN, we need to move
14320 	 * this to occur after we've validated the segment.
14321 	 */
14322 	if (tcp_ecn_input_segment(tp, thflags, iptos))
14323 		rack_cong_signal(tp, CC_ECN, th->th_ack, __LINE__);
14324 
14325 	/*
14326 	 * If echoed timestamp is later than the current time, fall back to
14327 	 * non RFC1323 RTT calculation.  Normalize timestamp if syncookies
14328 	 * were used when this connection was established.
14329 	 */
14330 	if ((to.to_flags & TOF_TS) && (to.to_tsecr != 0)) {
14331 		to.to_tsecr -= tp->ts_offset;
14332 		if (TSTMP_GT(to.to_tsecr, ms_cts))
14333 			to.to_tsecr = 0;
14334 	}
14335 
14336 	/*
14337 	 * If its the first time in we need to take care of options and
14338 	 * verify we can do SACK for rack!
14339 	 */
14340 	if (rack->r_state == 0) {
14341 		/* Should be init'd by rack_init() */
14342 		KASSERT(rack->rc_inp != NULL,
14343 		    ("%s: rack->rc_inp unexpectedly NULL", __func__));
14344 		if (rack->rc_inp == NULL) {
14345 			rack->rc_inp = tp->t_inpcb;
14346 		}
14347 
14348 		/*
14349 		 * Process options only when we get SYN/ACK back. The SYN
14350 		 * case for incoming connections is handled in tcp_syncache.
14351 		 * According to RFC1323 the window field in a SYN (i.e., a
14352 		 * <SYN> or <SYN,ACK>) segment itself is never scaled. XXX
14353 		 * this is traditional behavior, may need to be cleaned up.
14354 		 */
14355 		if (tp->t_state == TCPS_SYN_SENT && (thflags & TH_SYN)) {
14356 			/* Handle parallel SYN for ECN */
14357 			tcp_ecn_input_parallel_syn(tp, thflags, iptos);
14358 			if ((to.to_flags & TOF_SCALE) &&
14359 			    (tp->t_flags & TF_REQ_SCALE)) {
14360 				tp->t_flags |= TF_RCVD_SCALE;
14361 				tp->snd_scale = to.to_wscale;
14362 			} else
14363 				tp->t_flags &= ~TF_REQ_SCALE;
14364 			/*
14365 			 * Initial send window.  It will be updated with the
14366 			 * next incoming segment to the scaled value.
14367 			 */
14368 			tp->snd_wnd = th->th_win;
14369 			rack_validate_fo_sendwin_up(tp, rack);
14370 			if ((to.to_flags & TOF_TS) &&
14371 			    (tp->t_flags & TF_REQ_TSTMP)) {
14372 				tp->t_flags |= TF_RCVD_TSTMP;
14373 				tp->ts_recent = to.to_tsval;
14374 				tp->ts_recent_age = cts;
14375 			} else
14376 				tp->t_flags &= ~TF_REQ_TSTMP;
14377 			if (to.to_flags & TOF_MSS) {
14378 				tcp_mss(tp, to.to_mss);
14379 			}
14380 			if ((tp->t_flags & TF_SACK_PERMIT) &&
14381 			    (to.to_flags & TOF_SACKPERM) == 0)
14382 				tp->t_flags &= ~TF_SACK_PERMIT;
14383 			if (IS_FASTOPEN(tp->t_flags)) {
14384 				if (to.to_flags & TOF_FASTOPEN) {
14385 					uint16_t mss;
14386 
14387 					if (to.to_flags & TOF_MSS)
14388 						mss = to.to_mss;
14389 					else
14390 						if ((tp->t_inpcb->inp_vflag & INP_IPV6) != 0)
14391 							mss = TCP6_MSS;
14392 						else
14393 							mss = TCP_MSS;
14394 					tcp_fastopen_update_cache(tp, mss,
14395 					    to.to_tfo_len, to.to_tfo_cookie);
14396 				} else
14397 					tcp_fastopen_disable_path(tp);
14398 			}
14399 		}
14400 		/*
14401 		 * At this point we are at the initial call. Here we decide
14402 		 * if we are doing RACK or not. We do this by seeing if
14403 		 * TF_SACK_PERMIT is set and the sack-not-required is clear.
14404 		 * The code now does do dup-ack counting so if you don't
14405 		 * switch back you won't get rack & TLP, but you will still
14406 		 * get this stack.
14407 		 */
14408 
14409 		if ((rack_sack_not_required == 0) &&
14410 		    ((tp->t_flags & TF_SACK_PERMIT) == 0)) {
14411 			tcp_switch_back_to_default(tp);
14412 			(*tp->t_fb->tfb_tcp_do_segment) (m, th, so, tp, drop_hdrlen,
14413 			    tlen, iptos);
14414 #ifdef TCP_ACCOUNTING
14415 			sched_unpin();
14416 #endif
14417 			return (1);
14418 		}
14419 		tcp_set_hpts(tp->t_inpcb);
14420 		sack_filter_clear(&rack->r_ctl.rack_sf, th->th_ack);
14421 	}
14422 	if (thflags & TH_FIN)
14423 		tcp_log_end_status(tp, TCP_EI_STATUS_CLIENT_FIN);
14424 	us_cts = tcp_tv_to_usectick(&rack->r_ctl.act_rcv_time);
14425 	if ((rack->rc_gp_dyn_mul) &&
14426 	    (rack->use_fixed_rate == 0) &&
14427 	    (rack->rc_always_pace)) {
14428 		/* Check in on probertt */
14429 		rack_check_probe_rtt(rack, us_cts);
14430 	}
14431 	rack_clear_rate_sample(rack);
14432 	if ((rack->forced_ack) &&
14433 	    ((tcp_get_flags(th) & TH_RST) == 0)) {
14434 		rack_handle_probe_response(rack, tiwin, us_cts);
14435 	}
14436 	/*
14437 	 * This is the one exception case where we set the rack state
14438 	 * always. All other times (timers etc) we must have a rack-state
14439 	 * set (so we assure we have done the checks above for SACK).
14440 	 */
14441 	rack->r_ctl.rc_rcvtime = cts;
14442 	if (rack->r_state != tp->t_state)
14443 		rack_set_state(tp, rack);
14444 	if (SEQ_GT(th->th_ack, tp->snd_una) &&
14445 	    (rsm = RB_MIN(rack_rb_tree_head, &rack->r_ctl.rc_mtree)) != NULL)
14446 		kern_prefetch(rsm, &prev_state);
14447 	prev_state = rack->r_state;
14448 	retval = (*rack->r_substate) (m, th, so,
14449 	    tp, &to, drop_hdrlen,
14450 	    tlen, tiwin, thflags, nxt_pkt, iptos);
14451 #ifdef INVARIANTS
14452 	if ((retval == 0) &&
14453 	    (tp->t_inpcb == NULL)) {
14454 		panic("retval:%d tp:%p t_inpcb:NULL state:%d",
14455 		    retval, tp, prev_state);
14456 	}
14457 #endif
14458 	if (retval == 0) {
14459 		/*
14460 		 * If retval is 1 the tcb is unlocked and most likely the tp
14461 		 * is gone.
14462 		 */
14463 		INP_WLOCK_ASSERT(tp->t_inpcb);
14464 		if ((rack->rc_gp_dyn_mul) &&
14465 		    (rack->rc_always_pace) &&
14466 		    (rack->use_fixed_rate == 0) &&
14467 		    rack->in_probe_rtt &&
14468 		    (rack->r_ctl.rc_time_probertt_starts == 0)) {
14469 			/*
14470 			 * If we are going for target, lets recheck before
14471 			 * we output.
14472 			 */
14473 			rack_check_probe_rtt(rack, us_cts);
14474 		}
14475 		if (rack->set_pacing_done_a_iw == 0) {
14476 			/* How much has been acked? */
14477 			if ((tp->snd_una - tp->iss) > (ctf_fixed_maxseg(tp) * 10)) {
14478 				/* We have enough to set in the pacing segment size */
14479 				rack->set_pacing_done_a_iw = 1;
14480 				rack_set_pace_segments(tp, rack, __LINE__, NULL);
14481 			}
14482 		}
14483 		tcp_rack_xmit_timer_commit(rack, tp);
14484 #ifdef TCP_ACCOUNTING
14485 		/*
14486 		 * If we set the ack_val_se to what ack processing we are doing
14487 		 * we also want to track how many cycles we burned. Note
14488 		 * the bits after tcp_output we let be "free". This is because
14489 		 * we are also tracking the tcp_output times as well. Note the
14490 		 * use of 0xf here since we only have 11 counter (0 - 0xa) and
14491 		 * 0xf cannot be returned and is what we initialize it too to
14492 		 * indicate we are not doing the tabulations.
14493 		 */
14494 		if (ack_val_set != 0xf) {
14495 			uint64_t crtsc;
14496 
14497 			crtsc = get_cyclecount();
14498 			counter_u64_add(tcp_proc_time[ack_val_set] , (crtsc - ts_val));
14499 			if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
14500 				tp->tcp_proc_time[ack_val_set] += (crtsc - ts_val);
14501 			}
14502 		}
14503 #endif
14504 		if (nxt_pkt == 0) {
14505 			if ((rack->r_wanted_output != 0) || (rack->r_fast_output != 0)) {
14506 do_output_now:
14507 				if (tcp_output(tp) < 0)
14508 					return (1);
14509 				did_out = 1;
14510 			}
14511 			rack_start_hpts_timer(rack, tp, cts, 0, 0, 0);
14512 			rack_free_trim(rack);
14513 		}
14514 		/* Update any rounds needed */
14515 		if (rack_verbose_logging &&  (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF)) {
14516 			union tcp_log_stackspecific log;
14517 			struct timeval tv;
14518 
14519 			memset(&log.u_bbr, 0, sizeof(log.u_bbr));
14520 			log.u_bbr.timeStamp = tcp_get_usecs(&tv);
14521 			log.u_bbr.flex1 = high_seq;
14522 			log.u_bbr.flex2 = rack->r_ctl.roundends;
14523 			log.u_bbr.flex3 = rack->r_ctl.current_round;
14524 			log.u_bbr.rttProp = (uint64_t)CC_ALGO(tp)->newround;
14525 			log.u_bbr.flex8 = 9;
14526 			tcp_log_event_(tp, NULL, NULL, NULL, BBR_LOG_CWND, 0,
14527 				       0, &log, false, NULL, NULL, 0, &tv);
14528 		}
14529 		/*
14530 		 * The draft (v3) calls for us to use SEQ_GEQ, but that
14531 		 * causes issues when we are just going app limited. Lets
14532 		 * instead use SEQ_GT <or> where its equal but more data
14533 		 * is outstanding.
14534 		 */
14535 		if ((SEQ_GT(tp->snd_una, rack->r_ctl.roundends)) ||
14536 		    ((tp->snd_una == rack->r_ctl.roundends) && SEQ_GT(tp->snd_max, tp->snd_una))) {
14537 			rack->r_ctl.current_round++;
14538 			rack->r_ctl.roundends = tp->snd_max;
14539 			if (CC_ALGO(tp)->newround != NULL) {
14540 				CC_ALGO(tp)->newround(tp->ccv, rack->r_ctl.current_round);
14541 			}
14542 		}
14543 		if ((nxt_pkt == 0) &&
14544 		    ((rack->r_ctl.rc_hpts_flags & PACE_TMR_MASK) == 0) &&
14545 		    (SEQ_GT(tp->snd_max, tp->snd_una) ||
14546 		     (tp->t_flags & TF_DELACK) ||
14547 		     ((V_tcp_always_keepalive || rack->rc_inp->inp_socket->so_options & SO_KEEPALIVE) &&
14548 		      (tp->t_state <= TCPS_CLOSING)))) {
14549 			/* We could not send (probably in the hpts but stopped the timer earlier)? */
14550 			if ((tp->snd_max == tp->snd_una) &&
14551 			    ((tp->t_flags & TF_DELACK) == 0) &&
14552 			    (tcp_in_hpts(rack->rc_inp)) &&
14553 			    (rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT)) {
14554 				/* keep alive not needed if we are hptsi output yet */
14555 				;
14556 			} else {
14557 				int late = 0;
14558 				if (tcp_in_hpts(rack->rc_inp)) {
14559 					if (rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT) {
14560 						us_cts = tcp_get_usecs(NULL);
14561 						if (TSTMP_GT(rack->r_ctl.rc_last_output_to, us_cts)) {
14562 							rack->r_early = 1;
14563 							rack->r_ctl.rc_agg_early += (rack->r_ctl.rc_last_output_to - us_cts);
14564 						} else
14565 							late = 1;
14566 						rack->r_ctl.rc_hpts_flags &= ~PACE_PKT_OUTPUT;
14567 					}
14568 					tcp_hpts_remove(tp->t_inpcb);
14569 				}
14570 				if (late && (did_out == 0)) {
14571 					/*
14572 					 * We are late in the sending
14573 					 * and we did not call the output
14574 					 * (this probably should not happen).
14575 					 */
14576 					goto do_output_now;
14577 				}
14578 				rack_start_hpts_timer(rack, tp, tcp_get_usecs(NULL), 0, 0, 0);
14579 			}
14580 			way_out = 1;
14581 		} else if (nxt_pkt == 0) {
14582 			/* Do we have the correct timer running? */
14583 			rack_timer_audit(tp, rack, &so->so_snd);
14584 			way_out = 2;
14585 		}
14586 	done_with_input:
14587 		rack_log_doseg_done(rack, cts, nxt_pkt, did_out, way_out, max(1, nsegs));
14588 		if (did_out)
14589 			rack->r_wanted_output = 0;
14590 #ifdef INVARIANTS
14591 		if (tp->t_inpcb == NULL) {
14592 			panic("OP:%d retval:%d tp:%p t_inpcb:NULL state:%d",
14593 			      did_out,
14594 			      retval, tp, prev_state);
14595 		}
14596 #endif
14597 #ifdef TCP_ACCOUNTING
14598 	} else {
14599 		/*
14600 		 * Track the time (see above).
14601 		 */
14602 		if (ack_val_set != 0xf) {
14603 			uint64_t crtsc;
14604 
14605 			crtsc = get_cyclecount();
14606 			counter_u64_add(tcp_proc_time[ack_val_set] , (crtsc - ts_val));
14607 			/*
14608 			 * Note we *DO NOT* increment the per-tcb counters since
14609 			 * in the else the TP may be gone!!
14610 			 */
14611 		}
14612 #endif
14613 	}
14614 #ifdef TCP_ACCOUNTING
14615 	sched_unpin();
14616 #endif
14617 	return (retval);
14618 }
14619 
14620 void
14621 rack_do_segment(struct mbuf *m, struct tcphdr *th, struct socket *so,
14622     struct tcpcb *tp, int32_t drop_hdrlen, int32_t tlen, uint8_t iptos)
14623 {
14624 	struct timeval tv;
14625 
14626 	/* First lets see if we have old packets */
14627 	if (tp->t_in_pkt) {
14628 		if (ctf_do_queued_segments(so, tp, 1)) {
14629 			m_freem(m);
14630 			return;
14631 		}
14632 	}
14633 	if (m->m_flags & M_TSTMP_LRO) {
14634 		tv.tv_sec = m->m_pkthdr.rcv_tstmp /1000000000;
14635 		tv.tv_usec = (m->m_pkthdr.rcv_tstmp % 1000000000)/1000;
14636 	} else {
14637 		/* Should not be should we kassert instead? */
14638 		tcp_get_usecs(&tv);
14639 	}
14640 	if (rack_do_segment_nounlock(m, th, so, tp,
14641 				     drop_hdrlen, tlen, iptos, 0, &tv) == 0) {
14642 		INP_WUNLOCK(tp->t_inpcb);
14643 	}
14644 }
14645 
14646 struct rack_sendmap *
14647 tcp_rack_output(struct tcpcb *tp, struct tcp_rack *rack, uint32_t tsused)
14648 {
14649 	struct rack_sendmap *rsm = NULL;
14650 	int32_t idx;
14651 	uint32_t srtt = 0, thresh = 0, ts_low = 0;
14652 
14653 	/* Return the next guy to be re-transmitted */
14654 	if (RB_EMPTY(&rack->r_ctl.rc_mtree)) {
14655 		return (NULL);
14656 	}
14657 	if (tp->t_flags & TF_SENTFIN) {
14658 		/* retran the end FIN? */
14659 		return (NULL);
14660 	}
14661 	/* ok lets look at this one */
14662 	rsm = TAILQ_FIRST(&rack->r_ctl.rc_tmap);
14663 	if (rack->r_must_retran && rsm && (rsm->r_flags & RACK_MUST_RXT)) {
14664 		return (rsm);
14665 	}
14666 	if (rsm && ((rsm->r_flags & RACK_ACKED) == 0)) {
14667 		goto check_it;
14668 	}
14669 	rsm = rack_find_lowest_rsm(rack);
14670 	if (rsm == NULL) {
14671 		return (NULL);
14672 	}
14673 check_it:
14674 	if (((rack->rc_tp->t_flags & TF_SACK_PERMIT) == 0) &&
14675 	    (rsm->r_dupack >= DUP_ACK_THRESHOLD)) {
14676 		/*
14677 		 * No sack so we automatically do the 3 strikes and
14678 		 * retransmit (no rack timer would be started).
14679 		 */
14680 
14681 		return (rsm);
14682 	}
14683 	if (rsm->r_flags & RACK_ACKED) {
14684 		return (NULL);
14685 	}
14686 	if (((rsm->r_flags & RACK_SACK_PASSED) == 0) &&
14687 	    (rsm->r_dupack < DUP_ACK_THRESHOLD)) {
14688 		/* Its not yet ready */
14689 		return (NULL);
14690 	}
14691 	srtt = rack_grab_rtt(tp, rack);
14692 	idx = rsm->r_rtr_cnt - 1;
14693 	ts_low = (uint32_t)rsm->r_tim_lastsent[idx];
14694 	thresh = rack_calc_thresh_rack(rack, srtt, tsused);
14695 	if ((tsused == ts_low) ||
14696 	    (TSTMP_LT(tsused, ts_low))) {
14697 		/* No time since sending */
14698 		return (NULL);
14699 	}
14700 	if ((tsused - ts_low) < thresh) {
14701 		/* It has not been long enough yet */
14702 		return (NULL);
14703 	}
14704 	if ((rsm->r_dupack >= DUP_ACK_THRESHOLD) ||
14705 	    ((rsm->r_flags & RACK_SACK_PASSED) &&
14706 	     (rack->sack_attack_disable == 0))) {
14707 		/*
14708 		 * We have passed the dup-ack threshold <or>
14709 		 * a SACK has indicated this is missing.
14710 		 * Note that if you are a declared attacker
14711 		 * it is only the dup-ack threshold that
14712 		 * will cause retransmits.
14713 		 */
14714 		/* log retransmit reason */
14715 		rack_log_retran_reason(rack, rsm, (tsused - ts_low), thresh, 1);
14716 		rack->r_fast_output = 0;
14717 		return (rsm);
14718 	}
14719 	return (NULL);
14720 }
14721 
14722 static void
14723 rack_log_pacing_delay_calc(struct tcp_rack *rack, uint32_t len, uint32_t slot,
14724 			   uint64_t bw_est, uint64_t bw, uint64_t len_time, int method,
14725 			   int line, struct rack_sendmap *rsm, uint8_t quality)
14726 {
14727 	if (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
14728 		union tcp_log_stackspecific log;
14729 		struct timeval tv;
14730 
14731 		memset(&log, 0, sizeof(log));
14732 		log.u_bbr.flex1 = slot;
14733 		log.u_bbr.flex2 = len;
14734 		log.u_bbr.flex3 = rack->r_ctl.rc_pace_min_segs;
14735 		log.u_bbr.flex4 = rack->r_ctl.rc_pace_max_segs;
14736 		log.u_bbr.flex5 = rack->r_ctl.rack_per_of_gp_ss;
14737 		log.u_bbr.flex6 = rack->r_ctl.rack_per_of_gp_ca;
14738 		log.u_bbr.use_lt_bw = rack->rc_ack_can_sendout_data;
14739 		log.u_bbr.use_lt_bw <<= 1;
14740 		log.u_bbr.use_lt_bw |= rack->r_late;
14741 		log.u_bbr.use_lt_bw <<= 1;
14742 		log.u_bbr.use_lt_bw |= rack->r_early;
14743 		log.u_bbr.use_lt_bw <<= 1;
14744 		log.u_bbr.use_lt_bw |= rack->app_limited_needs_set;
14745 		log.u_bbr.use_lt_bw <<= 1;
14746 		log.u_bbr.use_lt_bw |= rack->rc_gp_filled;
14747 		log.u_bbr.use_lt_bw <<= 1;
14748 		log.u_bbr.use_lt_bw |= rack->measure_saw_probe_rtt;
14749 		log.u_bbr.use_lt_bw <<= 1;
14750 		log.u_bbr.use_lt_bw |= rack->in_probe_rtt;
14751 		log.u_bbr.use_lt_bw <<= 1;
14752 		log.u_bbr.use_lt_bw |= rack->gp_ready;
14753 		log.u_bbr.pkt_epoch = line;
14754 		log.u_bbr.epoch = rack->r_ctl.rc_agg_delayed;
14755 		log.u_bbr.lt_epoch = rack->r_ctl.rc_agg_early;
14756 		log.u_bbr.applimited = rack->r_ctl.rack_per_of_gp_rec;
14757 		log.u_bbr.bw_inuse = bw_est;
14758 		log.u_bbr.delRate = bw;
14759 		if (rack->r_ctl.gp_bw == 0)
14760 			log.u_bbr.cur_del_rate = 0;
14761 		else
14762 			log.u_bbr.cur_del_rate = rack_get_bw(rack);
14763 		log.u_bbr.rttProp = len_time;
14764 		log.u_bbr.pkts_out = rack->r_ctl.rc_rack_min_rtt;
14765 		log.u_bbr.lost = rack->r_ctl.rc_probertt_sndmax_atexit;
14766 		log.u_bbr.pacing_gain = rack_get_output_gain(rack, rsm);
14767 		if (rack->r_ctl.cwnd_to_use < rack->rc_tp->snd_ssthresh) {
14768 			/* We are in slow start */
14769 			log.u_bbr.flex7 = 1;
14770 		} else {
14771 			/* we are on congestion avoidance */
14772 			log.u_bbr.flex7 = 0;
14773 		}
14774 		log.u_bbr.flex8 = method;
14775 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
14776 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
14777 		log.u_bbr.cwnd_gain = rack->rc_gp_saw_rec;
14778 		log.u_bbr.cwnd_gain <<= 1;
14779 		log.u_bbr.cwnd_gain |= rack->rc_gp_saw_ss;
14780 		log.u_bbr.cwnd_gain <<= 1;
14781 		log.u_bbr.cwnd_gain |= rack->rc_gp_saw_ca;
14782 		log.u_bbr.bbr_substate = quality;
14783 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
14784 		    &rack->rc_inp->inp_socket->so_rcv,
14785 		    &rack->rc_inp->inp_socket->so_snd,
14786 		    BBR_LOG_HPTSI_CALC, 0,
14787 		    0, &log, false, &tv);
14788 	}
14789 }
14790 
14791 static uint32_t
14792 rack_get_pacing_len(struct tcp_rack *rack, uint64_t bw, uint32_t mss)
14793 {
14794 	uint32_t new_tso, user_max;
14795 
14796 	user_max = rack->rc_user_set_max_segs * mss;
14797 	if (rack->rc_force_max_seg) {
14798 		return (user_max);
14799 	}
14800 	if (rack->use_fixed_rate &&
14801 	    ((rack->r_ctl.crte == NULL) ||
14802 	     (bw != rack->r_ctl.crte->rate))) {
14803 		/* Use the user mss since we are not exactly matched */
14804 		return (user_max);
14805 	}
14806 	new_tso = tcp_get_pacing_burst_size(rack->rc_tp, bw, mss, rack_pace_one_seg, rack->r_ctl.crte, NULL);
14807 	if (new_tso > user_max)
14808 		new_tso = user_max;
14809 	return (new_tso);
14810 }
14811 
14812 static int32_t
14813 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)
14814 {
14815 	uint64_t lentim, fill_bw;
14816 
14817 	/* Lets first see if we are full, if so continue with normal rate */
14818 	rack->r_via_fill_cw = 0;
14819 	if (ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked) > rack->r_ctl.cwnd_to_use)
14820 		return (slot);
14821 	if ((ctf_outstanding(rack->rc_tp) + (segsiz-1)) > rack->rc_tp->snd_wnd)
14822 		return (slot);
14823 	if (rack->r_ctl.rc_last_us_rtt == 0)
14824 		return (slot);
14825 	if (rack->rc_pace_fill_if_rttin_range &&
14826 	    (rack->r_ctl.rc_last_us_rtt >=
14827 	     (get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt) * rack->rtt_limit_mul))) {
14828 		/* The rtt is huge, N * smallest, lets not fill */
14829 		return (slot);
14830 	}
14831 	/*
14832 	 * first lets calculate the b/w based on the last us-rtt
14833 	 * and the sndwnd.
14834 	 */
14835 	fill_bw = rack->r_ctl.cwnd_to_use;
14836 	/* Take the rwnd if its smaller */
14837 	if (fill_bw > rack->rc_tp->snd_wnd)
14838 		fill_bw = rack->rc_tp->snd_wnd;
14839 	if (rack->r_fill_less_agg) {
14840 		/*
14841 		 * Now take away the inflight (this will reduce our
14842 		 * aggressiveness and yeah, if we get that much out in 1RTT
14843 		 * we will have had acks come back and still be behind).
14844 		 */
14845 		fill_bw -= ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
14846 	}
14847 	/* Now lets make it into a b/w */
14848 	fill_bw *= (uint64_t)HPTS_USEC_IN_SEC;
14849 	fill_bw /= (uint64_t)rack->r_ctl.rc_last_us_rtt;
14850 	/* We are below the min b/w */
14851 	if (non_paced)
14852 		*rate_wanted = fill_bw;
14853 	if ((fill_bw < RACK_MIN_BW) || (fill_bw < *rate_wanted))
14854 		return (slot);
14855 	if (rack->r_ctl.bw_rate_cap && (fill_bw > rack->r_ctl.bw_rate_cap))
14856 		fill_bw = rack->r_ctl.bw_rate_cap;
14857 	rack->r_via_fill_cw = 1;
14858 	if (rack->r_rack_hw_rate_caps &&
14859 	    (rack->r_ctl.crte != NULL)) {
14860 		uint64_t high_rate;
14861 
14862 		high_rate = tcp_hw_highest_rate(rack->r_ctl.crte);
14863 		if (fill_bw > high_rate) {
14864 			/* We are capping bw at the highest rate table entry */
14865 			if (*rate_wanted > high_rate) {
14866 				/* The original rate was also capped */
14867 				rack->r_via_fill_cw = 0;
14868 			}
14869 			rack_log_hdwr_pacing(rack,
14870 					     fill_bw, high_rate, __LINE__,
14871 					     0, 3);
14872 			fill_bw = high_rate;
14873 			if (capped)
14874 				*capped = 1;
14875 		}
14876 	} else if ((rack->r_ctl.crte == NULL) &&
14877 		   (rack->rack_hdrw_pacing == 0) &&
14878 		   (rack->rack_hdw_pace_ena) &&
14879 		   rack->r_rack_hw_rate_caps &&
14880 		   (rack->rack_attempt_hdwr_pace == 0) &&
14881 		   (rack->rc_inp->inp_route.ro_nh != NULL) &&
14882 		   (rack->rc_inp->inp_route.ro_nh->nh_ifp != NULL)) {
14883 		/*
14884 		 * Ok we may have a first attempt that is greater than our top rate
14885 		 * lets check.
14886 		 */
14887 		uint64_t high_rate;
14888 
14889 		high_rate = tcp_hw_highest_rate_ifp(rack->rc_inp->inp_route.ro_nh->nh_ifp, rack->rc_inp);
14890 		if (high_rate) {
14891 			if (fill_bw > high_rate) {
14892 				fill_bw = high_rate;
14893 				if (capped)
14894 					*capped = 1;
14895 			}
14896 		}
14897 	}
14898 	/*
14899 	 * Ok fill_bw holds our mythical b/w to fill the cwnd
14900 	 * in a rtt, what does that time wise equate too?
14901 	 */
14902 	lentim = (uint64_t)(len) * (uint64_t)HPTS_USEC_IN_SEC;
14903 	lentim /= fill_bw;
14904 	*rate_wanted = fill_bw;
14905 	if (non_paced || (lentim < slot)) {
14906 		rack_log_pacing_delay_calc(rack, len, slot, fill_bw,
14907 					   0, lentim, 12, __LINE__, NULL, 0);
14908 		return ((int32_t)lentim);
14909 	} else
14910 		return (slot);
14911 }
14912 
14913 static int32_t
14914 rack_get_pacing_delay(struct tcp_rack *rack, struct tcpcb *tp, uint32_t len, struct rack_sendmap *rsm, uint32_t segsiz)
14915 {
14916 	uint64_t srtt;
14917 	int32_t slot = 0;
14918 	int can_start_hw_pacing = 1;
14919 	int err;
14920 
14921 	if (rack->rc_always_pace == 0) {
14922 		/*
14923 		 * We use the most optimistic possible cwnd/srtt for
14924 		 * sending calculations. This will make our
14925 		 * calculation anticipate getting more through
14926 		 * quicker then possible. But thats ok we don't want
14927 		 * the peer to have a gap in data sending.
14928 		 */
14929 		uint64_t cwnd, tr_perms = 0;
14930 		int32_t reduce = 0;
14931 
14932 	old_method:
14933 		/*
14934 		 * We keep no precise pacing with the old method
14935 		 * instead we use the pacer to mitigate bursts.
14936 		 */
14937 		if (rack->r_ctl.rc_rack_min_rtt)
14938 			srtt = rack->r_ctl.rc_rack_min_rtt;
14939 		else
14940 			srtt = max(tp->t_srtt, 1);
14941 		if (rack->r_ctl.rc_rack_largest_cwnd)
14942 			cwnd = rack->r_ctl.rc_rack_largest_cwnd;
14943 		else
14944 			cwnd = rack->r_ctl.cwnd_to_use;
14945 		/* Inflate cwnd by 1000 so srtt of usecs is in ms */
14946 		tr_perms = (cwnd * 1000) / srtt;
14947 		if (tr_perms == 0) {
14948 			tr_perms = ctf_fixed_maxseg(tp);
14949 		}
14950 		/*
14951 		 * Calculate how long this will take to drain, if
14952 		 * the calculation comes out to zero, thats ok we
14953 		 * will use send_a_lot to possibly spin around for
14954 		 * more increasing tot_len_this_send to the point
14955 		 * that its going to require a pace, or we hit the
14956 		 * cwnd. Which in that case we are just waiting for
14957 		 * a ACK.
14958 		 */
14959 		slot = len / tr_perms;
14960 		/* Now do we reduce the time so we don't run dry? */
14961 		if (slot && rack_slot_reduction) {
14962 			reduce = (slot / rack_slot_reduction);
14963 			if (reduce < slot) {
14964 				slot -= reduce;
14965 			} else
14966 				slot = 0;
14967 		}
14968 		slot *= HPTS_USEC_IN_MSEC;
14969 		if (rack->rc_pace_to_cwnd) {
14970 			uint64_t rate_wanted = 0;
14971 
14972 			slot = pace_to_fill_cwnd(rack, slot, len, segsiz, NULL, &rate_wanted, 1);
14973 			rack->rc_ack_can_sendout_data = 1;
14974 			rack_log_pacing_delay_calc(rack, len, slot, rate_wanted, 0, 0, 14, __LINE__, NULL, 0);
14975 		} else
14976 			rack_log_pacing_delay_calc(rack, len, slot, tr_perms, reduce, 0, 7, __LINE__, NULL, 0);
14977 	} else {
14978 		uint64_t bw_est, res, lentim, rate_wanted;
14979 		uint32_t orig_val, segs, oh;
14980 		int capped = 0;
14981 		int prev_fill;
14982 
14983 		if ((rack->r_rr_config == 1) && rsm) {
14984 			return (rack->r_ctl.rc_min_to);
14985 		}
14986 		if (rack->use_fixed_rate) {
14987 			rate_wanted = bw_est = rack_get_fixed_pacing_bw(rack);
14988 		} else if ((rack->r_ctl.init_rate == 0) &&
14989 #ifdef NETFLIX_PEAKRATE
14990 			   (rack->rc_tp->t_maxpeakrate == 0) &&
14991 #endif
14992 			   (rack->r_ctl.gp_bw == 0)) {
14993 			/* no way to yet do an estimate */
14994 			bw_est = rate_wanted = 0;
14995 		} else {
14996 			bw_est = rack_get_bw(rack);
14997 			rate_wanted = rack_get_output_bw(rack, bw_est, rsm, &capped);
14998 		}
14999 		if ((bw_est == 0) || (rate_wanted == 0) ||
15000 		    ((rack->gp_ready == 0) && (rack->use_fixed_rate == 0))) {
15001 			/*
15002 			 * No way yet to make a b/w estimate or
15003 			 * our raise is set incorrectly.
15004 			 */
15005 			goto old_method;
15006 		}
15007 		/* We need to account for all the overheads */
15008 		segs = (len + segsiz - 1) / segsiz;
15009 		/*
15010 		 * We need the diff between 1514 bytes (e-mtu with e-hdr)
15011 		 * and how much data we put in each packet. Yes this
15012 		 * means we may be off if we are larger than 1500 bytes
15013 		 * or smaller. But this just makes us more conservative.
15014 		 */
15015 		if (rack_hw_rate_min &&
15016 		    (bw_est < rack_hw_rate_min))
15017 			can_start_hw_pacing = 0;
15018 		if (ETHERNET_SEGMENT_SIZE > segsiz)
15019 			oh = ETHERNET_SEGMENT_SIZE - segsiz;
15020 		else
15021 			oh = 0;
15022 		segs *= oh;
15023 		lentim = (uint64_t)(len + segs) * (uint64_t)HPTS_USEC_IN_SEC;
15024 		res = lentim / rate_wanted;
15025 		slot = (uint32_t)res;
15026 		orig_val = rack->r_ctl.rc_pace_max_segs;
15027 		if (rack->r_ctl.crte == NULL) {
15028 			/*
15029 			 * Only do this if we are not hardware pacing
15030 			 * since if we are doing hw-pacing below we will
15031 			 * set make a call after setting up or changing
15032 			 * the rate.
15033 			 */
15034 			rack_set_pace_segments(rack->rc_tp, rack, __LINE__, NULL);
15035 		} else if (rack->rc_inp->inp_snd_tag == NULL) {
15036 			/*
15037 			 * We lost our rate somehow, this can happen
15038 			 * if the interface changed underneath us.
15039 			 */
15040 			tcp_rel_pacing_rate(rack->r_ctl.crte, rack->rc_tp);
15041 			rack->r_ctl.crte = NULL;
15042 			/* Lets re-allow attempting to setup pacing */
15043 			rack->rack_hdrw_pacing = 0;
15044 			rack->rack_attempt_hdwr_pace = 0;
15045 			rack_log_hdwr_pacing(rack,
15046 					     rate_wanted, bw_est, __LINE__,
15047 					     0, 6);
15048 		}
15049 		/* Did we change the TSO size, if so log it */
15050 		if (rack->r_ctl.rc_pace_max_segs != orig_val)
15051 			rack_log_pacing_delay_calc(rack, len, slot, orig_val, 0, 0, 15, __LINE__, NULL, 0);
15052 		prev_fill = rack->r_via_fill_cw;
15053 		if ((rack->rc_pace_to_cwnd) &&
15054 		    (capped == 0) &&
15055 		    (rack->use_fixed_rate == 0) &&
15056 		    (rack->in_probe_rtt == 0) &&
15057 		    (IN_FASTRECOVERY(rack->rc_tp->t_flags) == 0)) {
15058 			/*
15059 			 * We want to pace at our rate *or* faster to
15060 			 * fill the cwnd to the max if its not full.
15061 			 */
15062 			slot = pace_to_fill_cwnd(rack, slot, (len+segs), segsiz, &capped, &rate_wanted, 0);
15063 		}
15064 		if ((rack->rc_inp->inp_route.ro_nh != NULL) &&
15065 		    (rack->rc_inp->inp_route.ro_nh->nh_ifp != NULL)) {
15066 			if ((rack->rack_hdw_pace_ena) &&
15067 			    (can_start_hw_pacing > 0) &&
15068 			    (rack->rack_hdrw_pacing == 0) &&
15069 			    (rack->rack_attempt_hdwr_pace == 0)) {
15070 				/*
15071 				 * Lets attempt to turn on hardware pacing
15072 				 * if we can.
15073 				 */
15074 				rack->rack_attempt_hdwr_pace = 1;
15075 				rack->r_ctl.crte = tcp_set_pacing_rate(rack->rc_tp,
15076 								       rack->rc_inp->inp_route.ro_nh->nh_ifp,
15077 								       rate_wanted,
15078 								       RS_PACING_GEQ,
15079 								       &err, &rack->r_ctl.crte_prev_rate);
15080 				if (rack->r_ctl.crte) {
15081 					rack->rack_hdrw_pacing = 1;
15082 					rack->r_ctl.rc_pace_max_segs = tcp_get_pacing_burst_size(tp, rate_wanted, segsiz,
15083 												 0, rack->r_ctl.crte,
15084 												 NULL);
15085 					rack_log_hdwr_pacing(rack,
15086 							     rate_wanted, rack->r_ctl.crte->rate, __LINE__,
15087 							     err, 0);
15088 					rack->r_ctl.last_hw_bw_req = rate_wanted;
15089 				} else {
15090 					counter_u64_add(rack_hw_pace_init_fail, 1);
15091 				}
15092 			} else if (rack->rack_hdrw_pacing &&
15093 				   (rack->r_ctl.last_hw_bw_req != rate_wanted)) {
15094 				/* Do we need to adjust our rate? */
15095 				const struct tcp_hwrate_limit_table *nrte;
15096 
15097 				if (rack->r_up_only &&
15098 				    (rate_wanted < rack->r_ctl.crte->rate)) {
15099 					/**
15100 					 * We have four possible states here
15101 					 * having to do with the previous time
15102 					 * and this time.
15103 					 *   previous  |  this-time
15104 					 * A)     0      |     0   -- fill_cw not in the picture
15105 					 * B)     1      |     0   -- we were doing a fill-cw but now are not
15106 					 * C)     1      |     1   -- all rates from fill_cw
15107 					 * D)     0      |     1   -- we were doing non-fill and now we are filling
15108 					 *
15109 					 * For case A, C and D we don't allow a drop. But for
15110 					 * case B where we now our on our steady rate we do
15111 					 * allow a drop.
15112 					 *
15113 					 */
15114 					if (!((prev_fill == 1) && (rack->r_via_fill_cw == 0)))
15115 						goto done_w_hdwr;
15116 				}
15117 				if ((rate_wanted > rack->r_ctl.crte->rate) ||
15118 				    (rate_wanted <= rack->r_ctl.crte_prev_rate)) {
15119 					if (rack_hw_rate_to_low &&
15120 					    (bw_est < rack_hw_rate_to_low)) {
15121 						/*
15122 						 * The pacing rate is too low for hardware, but
15123 						 * do allow hardware pacing to be restarted.
15124 						 */
15125 						rack_log_hdwr_pacing(rack,
15126 							     bw_est, rack->r_ctl.crte->rate, __LINE__,
15127 							     0, 5);
15128 						tcp_rel_pacing_rate(rack->r_ctl.crte, rack->rc_tp);
15129 						rack->r_ctl.crte = NULL;
15130 						rack->rack_attempt_hdwr_pace = 0;
15131 						rack->rack_hdrw_pacing = 0;
15132 						rack_set_pace_segments(rack->rc_tp, rack, __LINE__, &rate_wanted);
15133 						goto done_w_hdwr;
15134 					}
15135 					nrte = tcp_chg_pacing_rate(rack->r_ctl.crte,
15136 								   rack->rc_tp,
15137 								   rack->rc_inp->inp_route.ro_nh->nh_ifp,
15138 								   rate_wanted,
15139 								   RS_PACING_GEQ,
15140 								   &err, &rack->r_ctl.crte_prev_rate);
15141 					if (nrte == NULL) {
15142 						/* Lost the rate */
15143 						rack->rack_hdrw_pacing = 0;
15144 						rack->r_ctl.crte = NULL;
15145 						rack_log_hdwr_pacing(rack,
15146 								     rate_wanted, 0, __LINE__,
15147 								     err, 1);
15148 						rack_set_pace_segments(rack->rc_tp, rack, __LINE__, &rate_wanted);
15149 						counter_u64_add(rack_hw_pace_lost, 1);
15150 					} else if (nrte != rack->r_ctl.crte) {
15151 						rack->r_ctl.crte = nrte;
15152 						rack->r_ctl.rc_pace_max_segs = tcp_get_pacing_burst_size(tp, rate_wanted,
15153 													 segsiz, 0,
15154 													 rack->r_ctl.crte,
15155 													 NULL);
15156 						rack_log_hdwr_pacing(rack,
15157 								     rate_wanted, rack->r_ctl.crte->rate, __LINE__,
15158 								     err, 2);
15159 						rack->r_ctl.last_hw_bw_req = rate_wanted;
15160 					}
15161 				} else {
15162 					/* We just need to adjust the segment size */
15163 					rack_set_pace_segments(rack->rc_tp, rack, __LINE__, &rate_wanted);
15164 					rack_log_hdwr_pacing(rack,
15165 							     rate_wanted, rack->r_ctl.crte->rate, __LINE__,
15166 							     0, 4);
15167 					rack->r_ctl.last_hw_bw_req = rate_wanted;
15168 				}
15169 			}
15170 		}
15171 		if ((rack->r_ctl.crte != NULL) &&
15172 		    (rack->r_ctl.crte->rate == rate_wanted)) {
15173 			/*
15174 			 * We need to add a extra if the rates
15175 			 * are exactly matched. The idea is
15176 			 * we want the software to make sure the
15177 			 * queue is empty before adding more, this
15178 			 * gives us N MSS extra pace times where
15179 			 * N is our sysctl
15180 			 */
15181 			slot += (rack->r_ctl.crte->time_between * rack_hw_pace_extra_slots);
15182 		}
15183 done_w_hdwr:
15184 		if (rack_limit_time_with_srtt &&
15185 		    (rack->use_fixed_rate == 0) &&
15186 #ifdef NETFLIX_PEAKRATE
15187 		    (rack->rc_tp->t_maxpeakrate == 0) &&
15188 #endif
15189 		    (rack->rack_hdrw_pacing == 0)) {
15190 			/*
15191 			 * Sanity check, we do not allow the pacing delay
15192 			 * to be longer than the SRTT of the path. If it is
15193 			 * a slow path, then adding a packet should increase
15194 			 * the RTT and compensate for this i.e. the srtt will
15195 			 * be greater so the allowed pacing time will be greater.
15196 			 *
15197 			 * Note this restriction is not for where a peak rate
15198 			 * is set, we are doing fixed pacing or hardware pacing.
15199 			 */
15200 			if (rack->rc_tp->t_srtt)
15201 				srtt = rack->rc_tp->t_srtt;
15202 			else
15203 				srtt = RACK_INITIAL_RTO * HPTS_USEC_IN_MSEC;	/* its in ms convert */
15204 			if (srtt < (uint64_t)slot) {
15205 				rack_log_pacing_delay_calc(rack, srtt, slot, rate_wanted, bw_est, lentim, 99, __LINE__, NULL, 0);
15206 				slot = srtt;
15207 			}
15208 		}
15209 		rack_log_pacing_delay_calc(rack, len, slot, rate_wanted, bw_est, lentim, 2, __LINE__, rsm, 0);
15210 	}
15211 	if (rack->r_ctl.crte && (rack->r_ctl.crte->rs_num_enobufs > 0)) {
15212 		/*
15213 		 * If this rate is seeing enobufs when it
15214 		 * goes to send then either the nic is out
15215 		 * of gas or we are mis-estimating the time
15216 		 * somehow and not letting the queue empty
15217 		 * completely. Lets add to the pacing time.
15218 		 */
15219 		int hw_boost_delay;
15220 
15221 		hw_boost_delay = rack->r_ctl.crte->time_between * rack_enobuf_hw_boost_mult;
15222 		if (hw_boost_delay > rack_enobuf_hw_max)
15223 			hw_boost_delay = rack_enobuf_hw_max;
15224 		else if (hw_boost_delay < rack_enobuf_hw_min)
15225 			hw_boost_delay = rack_enobuf_hw_min;
15226 		slot += hw_boost_delay;
15227 	}
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 = tcp_in_hpts(rack->rc_inp);
15484 		log.u_bbr.flex1 = error;
15485 		log.u_bbr.flex2 = flags;
15486 		log.u_bbr.flex3 = rsm_is_null;
15487 		log.u_bbr.flex4 = ipoptlen;
15488 		log.u_bbr.flex5 = tp->rcv_numsacks;
15489 		log.u_bbr.flex6 = rack->r_ctl.rc_agg_early;
15490 		log.u_bbr.flex7 = optlen;
15491 		log.u_bbr.flex8 = rack->r_fsb_inited;
15492 		log.u_bbr.applimited = rack->r_fast_output;
15493 		log.u_bbr.bw_inuse = rack_get_bw(rack);
15494 		log.u_bbr.pacing_gain = rack_get_output_gain(rack, NULL);
15495 		log.u_bbr.cwnd_gain = mode;
15496 		log.u_bbr.pkts_out = orig_len;
15497 		log.u_bbr.lt_epoch = len;
15498 		log.u_bbr.delivered = line;
15499 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
15500 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
15501 		tcp_log_event_(tp, NULL, &so->so_rcv, &so->so_snd, TCP_LOG_FSB, 0,
15502 			       len, &log, false, NULL, NULL, 0, &tv);
15503 	}
15504 }
15505 
15506 
15507 static struct mbuf *
15508 rack_fo_base_copym(struct mbuf *the_m, uint32_t the_off, int32_t *plen,
15509 		   struct rack_fast_send_blk *fsb,
15510 		   int32_t seglimit, int32_t segsize, int hw_tls)
15511 {
15512 #ifdef KERN_TLS
15513 	struct ktls_session *tls, *ntls;
15514 #ifdef INVARIANTS
15515 	struct mbuf *start;
15516 #endif
15517 #endif
15518 	struct mbuf *m, *n, **np, *smb;
15519 	struct mbuf *top;
15520 	int32_t off, soff;
15521 	int32_t len = *plen;
15522 	int32_t fragsize;
15523 	int32_t len_cp = 0;
15524 	uint32_t mlen, frags;
15525 
15526 	soff = off = the_off;
15527 	smb = m = the_m;
15528 	np = &top;
15529 	top = NULL;
15530 #ifdef KERN_TLS
15531 	if (hw_tls && (m->m_flags & M_EXTPG))
15532 		tls = m->m_epg_tls;
15533 	else
15534 		tls = NULL;
15535 #ifdef INVARIANTS
15536 	start = m;
15537 #endif
15538 #endif
15539 	while (len > 0) {
15540 		if (m == NULL) {
15541 			*plen = len_cp;
15542 			break;
15543 		}
15544 #ifdef KERN_TLS
15545 		if (hw_tls) {
15546 			if (m->m_flags & M_EXTPG)
15547 				ntls = m->m_epg_tls;
15548 			else
15549 				ntls = NULL;
15550 
15551 			/*
15552 			 * Avoid mixing TLS records with handshake
15553 			 * data or TLS records from different
15554 			 * sessions.
15555 			 */
15556 			if (tls != ntls) {
15557 				MPASS(m != start);
15558 				*plen = len_cp;
15559 				break;
15560 			}
15561 		}
15562 #endif
15563 		mlen = min(len, m->m_len - off);
15564 		if (seglimit) {
15565 			/*
15566 			 * For M_EXTPG mbufs, add 3 segments
15567 			 * + 1 in case we are crossing page boundaries
15568 			 * + 2 in case the TLS hdr/trailer are used
15569 			 * It is cheaper to just add the segments
15570 			 * than it is to take the cache miss to look
15571 			 * at the mbuf ext_pgs state in detail.
15572 			 */
15573 			if (m->m_flags & M_EXTPG) {
15574 				fragsize = min(segsize, PAGE_SIZE);
15575 				frags = 3;
15576 			} else {
15577 				fragsize = segsize;
15578 				frags = 0;
15579 			}
15580 
15581 			/* Break if we really can't fit anymore. */
15582 			if ((frags + 1) >= seglimit) {
15583 				*plen =	len_cp;
15584 				break;
15585 			}
15586 
15587 			/*
15588 			 * Reduce size if you can't copy the whole
15589 			 * mbuf. If we can't copy the whole mbuf, also
15590 			 * adjust len so the loop will end after this
15591 			 * mbuf.
15592 			 */
15593 			if ((frags + howmany(mlen, fragsize)) >= seglimit) {
15594 				mlen = (seglimit - frags - 1) * fragsize;
15595 				len = mlen;
15596 				*plen = len_cp + len;
15597 			}
15598 			frags += howmany(mlen, fragsize);
15599 			if (frags == 0)
15600 				frags++;
15601 			seglimit -= frags;
15602 			KASSERT(seglimit > 0,
15603 			    ("%s: seglimit went too low", __func__));
15604 		}
15605 		n = m_get(M_NOWAIT, m->m_type);
15606 		*np = n;
15607 		if (n == NULL)
15608 			goto nospace;
15609 		n->m_len = mlen;
15610 		soff += mlen;
15611 		len_cp += n->m_len;
15612 		if (m->m_flags & (M_EXT|M_EXTPG)) {
15613 			n->m_data = m->m_data + off;
15614 			mb_dupcl(n, m);
15615 		} else {
15616 			bcopy(mtod(m, caddr_t)+off, mtod(n, caddr_t),
15617 			    (u_int)n->m_len);
15618 		}
15619 		len -= n->m_len;
15620 		off = 0;
15621 		m = m->m_next;
15622 		np = &n->m_next;
15623 		if (len || (soff == smb->m_len)) {
15624 			/*
15625 			 * We have more so we move forward  or
15626 			 * we have consumed the entire mbuf and
15627 			 * len has fell to 0.
15628 			 */
15629 			soff = 0;
15630 			smb = m;
15631 		}
15632 
15633 	}
15634 	if (fsb != NULL) {
15635 		fsb->m = smb;
15636 		fsb->off = soff;
15637 		if (smb) {
15638 			/*
15639 			 * Save off the size of the mbuf. We do
15640 			 * this so that we can recognize when it
15641 			 * has been trimmed by sbcut() as acks
15642 			 * come in.
15643 			 */
15644 			fsb->o_m_len = smb->m_len;
15645 		} else {
15646 			/*
15647 			 * This is the case where the next mbuf went to NULL. This
15648 			 * means with this copy we have sent everything in the sb.
15649 			 * In theory we could clear the fast_output flag, but lets
15650 			 * not since its possible that we could get more added
15651 			 * and acks that call the extend function which would let
15652 			 * us send more.
15653 			 */
15654 			fsb->o_m_len = 0;
15655 		}
15656 	}
15657 	return (top);
15658 nospace:
15659 	if (top)
15660 		m_freem(top);
15661 	return (NULL);
15662 
15663 }
15664 
15665 /*
15666  * This is a copy of m_copym(), taking the TSO segment size/limit
15667  * constraints into account, and advancing the sndptr as it goes.
15668  */
15669 static struct mbuf *
15670 rack_fo_m_copym(struct tcp_rack *rack, int32_t *plen,
15671 		int32_t seglimit, int32_t segsize, struct mbuf **s_mb, int *s_soff)
15672 {
15673 	struct mbuf *m, *n;
15674 	int32_t soff;
15675 
15676 	soff = rack->r_ctl.fsb.off;
15677 	m = rack->r_ctl.fsb.m;
15678 	if (rack->r_ctl.fsb.o_m_len > m->m_len) {
15679 		/*
15680 		 * The mbuf had the front of it chopped off by an ack
15681 		 * we need to adjust the soff/off by that difference.
15682 		 */
15683 		uint32_t delta;
15684 
15685 		delta = rack->r_ctl.fsb.o_m_len - m->m_len;
15686 		soff -= delta;
15687 	} else if (rack->r_ctl.fsb.o_m_len < m->m_len) {
15688 		/*
15689 		 * The mbuf was expanded probably by
15690 		 * a m_compress. Just update o_m_len.
15691 		 */
15692 		rack->r_ctl.fsb.o_m_len = m->m_len;
15693 	}
15694 	KASSERT(soff >= 0, ("%s, negative off %d", __FUNCTION__, soff));
15695 	KASSERT(*plen >= 0, ("%s, negative len %d", __FUNCTION__, *plen));
15696 	KASSERT(soff < m->m_len, ("%s rack:%p len:%u m:%p m->m_len:%u < off?",
15697 				 __FUNCTION__,
15698 				 rack, *plen, m, m->m_len));
15699 	/* Save off the right location before we copy and advance */
15700 	*s_soff = soff;
15701 	*s_mb = rack->r_ctl.fsb.m;
15702 	n = rack_fo_base_copym(m, soff, plen,
15703 			       &rack->r_ctl.fsb,
15704 			       seglimit, segsize, rack->r_ctl.fsb.hw_tls);
15705 	return (n);
15706 }
15707 
15708 static int
15709 rack_fast_rsm_output(struct tcpcb *tp, struct tcp_rack *rack, struct rack_sendmap *rsm,
15710 		     uint64_t ts_val, uint32_t cts, uint32_t ms_cts, struct timeval *tv, int len, uint8_t doing_tlp)
15711 {
15712 	/*
15713 	 * Enter the fast retransmit path. We are given that a sched_pin is
15714 	 * in place (if accounting is compliled in) and the cycle count taken
15715 	 * at the entry is in the ts_val. The concept her is that the rsm
15716 	 * now holds the mbuf offsets and such so we can directly transmit
15717 	 * without a lot of overhead, the len field is already set for
15718 	 * us to prohibit us from sending too much (usually its 1MSS).
15719 	 */
15720 	struct ip *ip = NULL;
15721 	struct udphdr *udp = NULL;
15722 	struct tcphdr *th = NULL;
15723 	struct mbuf *m = NULL;
15724 	struct inpcb *inp;
15725 	uint8_t *cpto;
15726 	struct tcp_log_buffer *lgb;
15727 #ifdef TCP_ACCOUNTING
15728 	uint64_t crtsc;
15729 	int cnt_thru = 1;
15730 #endif
15731 	struct tcpopt to;
15732 	u_char opt[TCP_MAXOLEN];
15733 	uint32_t hdrlen, optlen;
15734 	int32_t slot, segsiz, max_val, tso = 0, error, ulen = 0;
15735 	uint16_t flags;
15736 	uint32_t if_hw_tsomaxsegcount = 0, startseq;
15737 	uint32_t if_hw_tsomaxsegsize;
15738 
15739 #ifdef INET6
15740 	struct ip6_hdr *ip6 = NULL;
15741 
15742 	if (rack->r_is_v6) {
15743 		ip6 = (struct ip6_hdr *)rack->r_ctl.fsb.tcp_ip_hdr;
15744 		hdrlen = sizeof(struct ip6_hdr) + sizeof(struct tcphdr);
15745 	} else
15746 #endif				/* INET6 */
15747 	{
15748 		ip = (struct ip *)rack->r_ctl.fsb.tcp_ip_hdr;
15749 		hdrlen = sizeof(struct tcpiphdr);
15750 	}
15751 	if (tp->t_port && (V_tcp_udp_tunneling_port == 0)) {
15752 		goto failed;
15753 	}
15754 	if (doing_tlp) {
15755 		/* Its a TLP add the flag, it may already be there but be sure */
15756 		rsm->r_flags |= RACK_TLP;
15757 	} else {
15758 		/* If it was a TLP it is not not on this retransmit */
15759 		rsm->r_flags &= ~RACK_TLP;
15760 	}
15761 	startseq = rsm->r_start;
15762 	segsiz = min(ctf_fixed_maxseg(tp), rack->r_ctl.rc_pace_min_segs);
15763 	inp = rack->rc_inp;
15764 	to.to_flags = 0;
15765 	flags = tcp_outflags[tp->t_state];
15766 	if (flags & (TH_SYN|TH_RST)) {
15767 		goto failed;
15768 	}
15769 	if (rsm->r_flags & RACK_HAS_FIN) {
15770 		/* We can't send a FIN here */
15771 		goto failed;
15772 	}
15773 	if (flags & TH_FIN) {
15774 		/* We never send a FIN */
15775 		flags &= ~TH_FIN;
15776 	}
15777 	if (tp->t_flags & TF_RCVD_TSTMP) {
15778 		to.to_tsval = ms_cts + tp->ts_offset;
15779 		to.to_tsecr = tp->ts_recent;
15780 		to.to_flags = TOF_TS;
15781 	}
15782 	optlen = tcp_addoptions(&to, opt);
15783 	hdrlen += optlen;
15784 	udp = rack->r_ctl.fsb.udp;
15785 	if (udp)
15786 		hdrlen += sizeof(struct udphdr);
15787 	if (rack->r_ctl.rc_pace_max_segs)
15788 		max_val = rack->r_ctl.rc_pace_max_segs;
15789 	else if (rack->rc_user_set_max_segs)
15790 		max_val = rack->rc_user_set_max_segs * segsiz;
15791 	else
15792 		max_val = len;
15793 	if ((tp->t_flags & TF_TSO) &&
15794 	    V_tcp_do_tso &&
15795 	    (len > segsiz) &&
15796 	    (tp->t_port == 0))
15797 		tso = 1;
15798 #ifdef INET6
15799 	if (MHLEN < hdrlen + max_linkhdr)
15800 		m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR);
15801 	else
15802 #endif
15803 		m = m_gethdr(M_NOWAIT, MT_DATA);
15804 	if (m == NULL)
15805 		goto failed;
15806 	m->m_data += max_linkhdr;
15807 	m->m_len = hdrlen;
15808 	th = rack->r_ctl.fsb.th;
15809 	/* Establish the len to send */
15810 	if (len > max_val)
15811 		len = max_val;
15812 	if ((tso) && (len + optlen > tp->t_maxseg)) {
15813 		uint32_t if_hw_tsomax;
15814 		int32_t max_len;
15815 
15816 		/* extract TSO information */
15817 		if_hw_tsomax = tp->t_tsomax;
15818 		if_hw_tsomaxsegcount = tp->t_tsomaxsegcount;
15819 		if_hw_tsomaxsegsize = tp->t_tsomaxsegsize;
15820 		/*
15821 		 * Check if we should limit by maximum payload
15822 		 * length:
15823 		 */
15824 		if (if_hw_tsomax != 0) {
15825 			/* compute maximum TSO length */
15826 			max_len = (if_hw_tsomax - hdrlen -
15827 				   max_linkhdr);
15828 			if (max_len <= 0) {
15829 				goto failed;
15830 			} else if (len > max_len) {
15831 				len = max_len;
15832 			}
15833 		}
15834 		if (len <= segsiz) {
15835 			/*
15836 			 * In case there are too many small fragments don't
15837 			 * use TSO:
15838 			 */
15839 			tso = 0;
15840 		}
15841 	} else {
15842 		tso = 0;
15843 	}
15844 	if ((tso == 0) && (len > segsiz))
15845 		len = segsiz;
15846 	if ((len == 0) ||
15847 	    (len <= MHLEN - hdrlen - max_linkhdr)) {
15848 		goto failed;
15849 	}
15850 	th->th_seq = htonl(rsm->r_start);
15851 	th->th_ack = htonl(tp->rcv_nxt);
15852 	/*
15853 	 * The PUSH bit should only be applied
15854 	 * if the full retransmission is made. If
15855 	 * we are sending less than this is the
15856 	 * left hand edge and should not have
15857 	 * the PUSH bit.
15858 	 */
15859 	if ((rsm->r_flags & RACK_HAD_PUSH) &&
15860 	    (len == (rsm->r_end - rsm->r_start)))
15861 		flags |= TH_PUSH;
15862 	th->th_win = htons((u_short)(rack->r_ctl.fsb.recwin >> tp->rcv_scale));
15863 	if (th->th_win == 0) {
15864 		tp->t_sndzerowin++;
15865 		tp->t_flags |= TF_RXWIN0SENT;
15866 	} else
15867 		tp->t_flags &= ~TF_RXWIN0SENT;
15868 	if (rsm->r_flags & RACK_TLP) {
15869 		/*
15870 		 * TLP should not count in retran count, but
15871 		 * in its own bin
15872 		 */
15873 		counter_u64_add(rack_tlp_retran, 1);
15874 		counter_u64_add(rack_tlp_retran_bytes, len);
15875 	} else {
15876 		tp->t_sndrexmitpack++;
15877 		KMOD_TCPSTAT_INC(tcps_sndrexmitpack);
15878 		KMOD_TCPSTAT_ADD(tcps_sndrexmitbyte, len);
15879 	}
15880 #ifdef STATS
15881 	stats_voi_update_abs_u32(tp->t_stats, VOI_TCP_RETXPB,
15882 				 len);
15883 #endif
15884 	if (rsm->m == NULL)
15885 		goto failed;
15886 	if (rsm->orig_m_len != rsm->m->m_len) {
15887 		/* Fix up the orig_m_len and possibly the mbuf offset */
15888 		rack_adjust_orig_mlen(rsm);
15889 	}
15890 	m->m_next = rack_fo_base_copym(rsm->m, rsm->soff, &len, NULL, if_hw_tsomaxsegcount, if_hw_tsomaxsegsize, rsm->r_hw_tls);
15891 	if (len <= segsiz) {
15892 		/*
15893 		 * Must have ran out of mbufs for the copy
15894 		 * shorten it to no longer need tso. Lets
15895 		 * not put on sendalot since we are low on
15896 		 * mbufs.
15897 		 */
15898 		tso = 0;
15899 	}
15900 	if ((m->m_next == NULL) || (len <= 0)){
15901 		goto failed;
15902 	}
15903 	if (udp) {
15904 		if (rack->r_is_v6)
15905 			ulen = hdrlen + len - sizeof(struct ip6_hdr);
15906 		else
15907 			ulen = hdrlen + len - sizeof(struct ip);
15908 		udp->uh_ulen = htons(ulen);
15909 	}
15910 	m->m_pkthdr.rcvif = (struct ifnet *)0;
15911 	if (TCPS_HAVERCVDSYN(tp->t_state) &&
15912 	    (tp->t_flags2 & (TF2_ECN_PERMIT | TF2_ACE_PERMIT))) {
15913 		int ect = tcp_ecn_output_established(tp, &flags, len, true);
15914 		if ((tp->t_state == TCPS_SYN_RECEIVED) &&
15915 		    (tp->t_flags2 & TF2_ECN_SND_ECE))
15916 		    tp->t_flags2 &= ~TF2_ECN_SND_ECE;
15917 #ifdef INET6
15918 		if (rack->r_is_v6) {
15919 		    ip6->ip6_flow &= ~htonl(IPTOS_ECN_MASK << 20);
15920 		    ip6->ip6_flow |= htonl(ect << 20);
15921 		}
15922 		else
15923 #endif
15924 		{
15925 		    ip->ip_tos &= ~IPTOS_ECN_MASK;
15926 		    ip->ip_tos |= ect;
15927 		}
15928 	}
15929 	tcp_set_flags(th, flags);
15930 	m->m_pkthdr.len = hdrlen + len;	/* in6_cksum() need this */
15931 #ifdef INET6
15932 	if (rack->r_is_v6) {
15933 		if (tp->t_port) {
15934 			m->m_pkthdr.csum_flags = CSUM_UDP_IPV6;
15935 			m->m_pkthdr.csum_data = offsetof(struct udphdr, uh_sum);
15936 			udp->uh_sum = in6_cksum_pseudo(ip6, ulen, IPPROTO_UDP, 0);
15937 			th->th_sum = htons(0);
15938 			UDPSTAT_INC(udps_opackets);
15939 		} else {
15940 			m->m_pkthdr.csum_flags = CSUM_TCP_IPV6;
15941 			m->m_pkthdr.csum_data = offsetof(struct tcphdr, th_sum);
15942 			th->th_sum = in6_cksum_pseudo(ip6,
15943 						      sizeof(struct tcphdr) + optlen + len, IPPROTO_TCP,
15944 						      0);
15945 		}
15946 	}
15947 #endif
15948 #if defined(INET6) && defined(INET)
15949 	else
15950 #endif
15951 #ifdef INET
15952 	{
15953 		if (tp->t_port) {
15954 			m->m_pkthdr.csum_flags = CSUM_UDP;
15955 			m->m_pkthdr.csum_data = offsetof(struct udphdr, uh_sum);
15956 			udp->uh_sum = in_pseudo(ip->ip_src.s_addr,
15957 						ip->ip_dst.s_addr, htons(ulen + IPPROTO_UDP));
15958 			th->th_sum = htons(0);
15959 			UDPSTAT_INC(udps_opackets);
15960 		} else {
15961 			m->m_pkthdr.csum_flags = CSUM_TCP;
15962 			m->m_pkthdr.csum_data = offsetof(struct tcphdr, th_sum);
15963 			th->th_sum = in_pseudo(ip->ip_src.s_addr,
15964 					       ip->ip_dst.s_addr, htons(sizeof(struct tcphdr) +
15965 									IPPROTO_TCP + len + optlen));
15966 		}
15967 		/* IP version must be set here for ipv4/ipv6 checking later */
15968 		KASSERT(ip->ip_v == IPVERSION,
15969 			("%s: IP version incorrect: %d", __func__, ip->ip_v));
15970 	}
15971 #endif
15972 	if (tso) {
15973 		KASSERT(len > tp->t_maxseg - optlen,
15974 			("%s: len <= tso_segsz tp:%p", __func__, tp));
15975 		m->m_pkthdr.csum_flags |= CSUM_TSO;
15976 		m->m_pkthdr.tso_segsz = tp->t_maxseg - optlen;
15977 	}
15978 #ifdef INET6
15979 	if (rack->r_is_v6) {
15980 		ip6->ip6_hlim = rack->r_ctl.fsb.hoplimit;
15981 		ip6->ip6_plen = htons(m->m_pkthdr.len - sizeof(*ip6));
15982 		if (V_path_mtu_discovery && tp->t_maxseg > V_tcp_minmss)
15983 			tp->t_flags2 |= TF2_PLPMTU_PMTUD;
15984 		else
15985 			tp->t_flags2 &= ~TF2_PLPMTU_PMTUD;
15986 	}
15987 #endif
15988 #if defined(INET) && defined(INET6)
15989 	else
15990 #endif
15991 #ifdef INET
15992 	{
15993 		ip->ip_len = htons(m->m_pkthdr.len);
15994 		ip->ip_ttl = rack->r_ctl.fsb.hoplimit;
15995 		if (V_path_mtu_discovery && tp->t_maxseg > V_tcp_minmss) {
15996 			tp->t_flags2 |= TF2_PLPMTU_PMTUD;
15997 			if (tp->t_port == 0 || len < V_tcp_minmss) {
15998 				ip->ip_off |= htons(IP_DF);
15999 			}
16000 		} else {
16001 			tp->t_flags2 &= ~TF2_PLPMTU_PMTUD;
16002 		}
16003 	}
16004 #endif
16005 	/* Time to copy in our header */
16006 	cpto = mtod(m, uint8_t *);
16007 	memcpy(cpto, rack->r_ctl.fsb.tcp_ip_hdr, rack->r_ctl.fsb.tcp_ip_hdr_len);
16008 	th = (struct tcphdr *)(cpto + ((uint8_t *)rack->r_ctl.fsb.th - rack->r_ctl.fsb.tcp_ip_hdr));
16009 	if (optlen) {
16010 		bcopy(opt, th + 1, optlen);
16011 		th->th_off = (sizeof(struct tcphdr) + optlen) >> 2;
16012 	} else {
16013 		th->th_off = sizeof(struct tcphdr) >> 2;
16014 	}
16015 	if (tp->t_logstate != TCP_LOG_STATE_OFF) {
16016 		union tcp_log_stackspecific log;
16017 
16018 		if (rsm->r_flags & RACK_RWND_COLLAPSED) {
16019 			rack_log_collapse(rack, rsm->r_start, rsm->r_end, 0, __LINE__, 5, rsm->r_flags, rsm);
16020 			counter_u64_add(rack_collapsed_win_rxt, 1);
16021 			counter_u64_add(rack_collapsed_win_rxt_bytes, (rsm->r_end - rsm->r_start));
16022 		}
16023 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
16024 		log.u_bbr.inhpts = tcp_in_hpts(rack->rc_inp);
16025 		if (rack->rack_no_prr)
16026 			log.u_bbr.flex1 = 0;
16027 		else
16028 			log.u_bbr.flex1 = rack->r_ctl.rc_prr_sndcnt;
16029 		log.u_bbr.flex2 = rack->r_ctl.rc_pace_min_segs;
16030 		log.u_bbr.flex3 = rack->r_ctl.rc_pace_max_segs;
16031 		log.u_bbr.flex4 = max_val;
16032 		log.u_bbr.flex5 = 0;
16033 		/* Save off the early/late values */
16034 		log.u_bbr.flex6 = rack->r_ctl.rc_agg_early;
16035 		log.u_bbr.applimited = rack->r_ctl.rc_agg_delayed;
16036 		log.u_bbr.bw_inuse = rack_get_bw(rack);
16037 		if (doing_tlp == 0)
16038 			log.u_bbr.flex8 = 1;
16039 		else
16040 			log.u_bbr.flex8 = 2;
16041 		log.u_bbr.pacing_gain = rack_get_output_gain(rack, NULL);
16042 		log.u_bbr.flex7 = 55;
16043 		log.u_bbr.pkts_out = tp->t_maxseg;
16044 		log.u_bbr.timeStamp = cts;
16045 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
16046 		log.u_bbr.lt_epoch = rack->r_ctl.cwnd_to_use;
16047 		log.u_bbr.delivered = 0;
16048 		lgb = tcp_log_event_(tp, th, NULL, NULL, TCP_LOG_OUT, ERRNO_UNK,
16049 				     len, &log, false, NULL, NULL, 0, tv);
16050 	} else
16051 		lgb = NULL;
16052 #ifdef INET6
16053 	if (rack->r_is_v6) {
16054 		error = ip6_output(m, NULL,
16055 				   &inp->inp_route6,
16056 				   0, NULL, NULL, inp);
16057 	}
16058 #endif
16059 #if defined(INET) && defined(INET6)
16060 	else
16061 #endif
16062 #ifdef INET
16063 	{
16064 		error = ip_output(m, NULL,
16065 				  &inp->inp_route,
16066 				  0, 0, inp);
16067 	}
16068 #endif
16069 	m = NULL;
16070 	if (lgb) {
16071 		lgb->tlb_errno = error;
16072 		lgb = NULL;
16073 	}
16074 	if (error) {
16075 		goto failed;
16076 	}
16077 	rack_log_output(tp, &to, len, rsm->r_start, flags, error, rack_to_usec_ts(tv),
16078 			rsm, RACK_SENT_FP, rsm->m, rsm->soff, rsm->r_hw_tls);
16079 	if (doing_tlp && (rack->fast_rsm_hack == 0)) {
16080 		rack->rc_tlp_in_progress = 1;
16081 		rack->r_ctl.rc_tlp_cnt_out++;
16082 	}
16083 	if (error == 0) {
16084 		tcp_account_for_send(tp, len, 1, doing_tlp, rsm->r_hw_tls);
16085 		if (doing_tlp) {
16086 			rack->rc_last_sent_tlp_past_cumack = 0;
16087 			rack->rc_last_sent_tlp_seq_valid = 1;
16088 			rack->r_ctl.last_sent_tlp_seq = rsm->r_start;
16089 			rack->r_ctl.last_sent_tlp_len = rsm->r_end - rsm->r_start;
16090 		}
16091 	}
16092 	tp->t_flags &= ~(TF_ACKNOW | TF_DELACK);
16093 	rack->forced_ack = 0;	/* If we send something zap the FA flag */
16094 	if (IN_FASTRECOVERY(tp->t_flags) && rsm)
16095 		rack->r_ctl.retran_during_recovery += len;
16096 	{
16097 		int idx;
16098 
16099 		idx = (len / segsiz) + 3;
16100 		if (idx >= TCP_MSS_ACCT_ATIMER)
16101 			counter_u64_add(rack_out_size[(TCP_MSS_ACCT_ATIMER-1)], 1);
16102 		else
16103 			counter_u64_add(rack_out_size[idx], 1);
16104 	}
16105 	if (tp->t_rtttime == 0) {
16106 		tp->t_rtttime = ticks;
16107 		tp->t_rtseq = startseq;
16108 		KMOD_TCPSTAT_INC(tcps_segstimed);
16109 	}
16110 	counter_u64_add(rack_fto_rsm_send, 1);
16111 	if (error && (error == ENOBUFS)) {
16112 		if (rack->r_ctl.crte != NULL) {
16113 			rack_trace_point(rack, RACK_TP_HWENOBUF);
16114 		} else
16115 			rack_trace_point(rack, RACK_TP_ENOBUF);
16116 		slot = ((1 + rack->rc_enobuf) * HPTS_USEC_IN_MSEC);
16117 		if (rack->rc_enobuf < 0x7f)
16118 			rack->rc_enobuf++;
16119 		if (slot < (10 * HPTS_USEC_IN_MSEC))
16120 			slot = 10 * HPTS_USEC_IN_MSEC;
16121 	} else
16122 		slot = rack_get_pacing_delay(rack, tp, len, NULL, segsiz);
16123 	if ((slot == 0) ||
16124 	    (rack->rc_always_pace == 0) ||
16125 	    (rack->r_rr_config == 1)) {
16126 		/*
16127 		 * We have no pacing set or we
16128 		 * are using old-style rack or
16129 		 * we are overridden to use the old 1ms pacing.
16130 		 */
16131 		slot = rack->r_ctl.rc_min_to;
16132 	}
16133 	rack_start_hpts_timer(rack, tp, cts, slot, len, 0);
16134 #ifdef TCP_ACCOUNTING
16135 	crtsc = get_cyclecount();
16136 	if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
16137 		tp->tcp_cnt_counters[SND_OUT_DATA] += cnt_thru;
16138 	}
16139 	counter_u64_add(tcp_cnt_counters[SND_OUT_DATA], cnt_thru);
16140 	if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
16141 		tp->tcp_proc_time[SND_OUT_DATA] += (crtsc - ts_val);
16142 	}
16143 	counter_u64_add(tcp_proc_time[SND_OUT_DATA], (crtsc - ts_val));
16144 	if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
16145 		tp->tcp_cnt_counters[CNT_OF_MSS_OUT] += ((len + segsiz - 1) / segsiz);
16146 	}
16147 	counter_u64_add(tcp_cnt_counters[CNT_OF_MSS_OUT], ((len + segsiz - 1) / segsiz));
16148 	sched_unpin();
16149 #endif
16150 	return (0);
16151 failed:
16152 	if (m)
16153 		m_free(m);
16154 	return (-1);
16155 }
16156 
16157 static void
16158 rack_sndbuf_autoscale(struct tcp_rack *rack)
16159 {
16160 	/*
16161 	 * Automatic sizing of send socket buffer.  Often the send buffer
16162 	 * size is not optimally adjusted to the actual network conditions
16163 	 * at hand (delay bandwidth product).  Setting the buffer size too
16164 	 * small limits throughput on links with high bandwidth and high
16165 	 * delay (eg. trans-continental/oceanic links).  Setting the
16166 	 * buffer size too big consumes too much real kernel memory,
16167 	 * especially with many connections on busy servers.
16168 	 *
16169 	 * The criteria to step up the send buffer one notch are:
16170 	 *  1. receive window of remote host is larger than send buffer
16171 	 *     (with a fudge factor of 5/4th);
16172 	 *  2. send buffer is filled to 7/8th with data (so we actually
16173 	 *     have data to make use of it);
16174 	 *  3. send buffer fill has not hit maximal automatic size;
16175 	 *  4. our send window (slow start and cogestion controlled) is
16176 	 *     larger than sent but unacknowledged data in send buffer.
16177 	 *
16178 	 * Note that the rack version moves things much faster since
16179 	 * we want to avoid hitting cache lines in the rack_fast_output()
16180 	 * path so this is called much less often and thus moves
16181 	 * the SB forward by a percentage.
16182 	 */
16183 	struct socket *so;
16184 	struct tcpcb *tp;
16185 	uint32_t sendwin, scaleup;
16186 
16187 	tp = rack->rc_tp;
16188 	so = rack->rc_inp->inp_socket;
16189 	sendwin = min(rack->r_ctl.cwnd_to_use, tp->snd_wnd);
16190 	if (V_tcp_do_autosndbuf && so->so_snd.sb_flags & SB_AUTOSIZE) {
16191 		if ((tp->snd_wnd / 4 * 5) >= so->so_snd.sb_hiwat &&
16192 		    sbused(&so->so_snd) >=
16193 		    (so->so_snd.sb_hiwat / 8 * 7) &&
16194 		    sbused(&so->so_snd) < V_tcp_autosndbuf_max &&
16195 		    sendwin >= (sbused(&so->so_snd) -
16196 		    (tp->snd_nxt - tp->snd_una))) {
16197 			if (rack_autosndbuf_inc)
16198 				scaleup = (rack_autosndbuf_inc * so->so_snd.sb_hiwat) / 100;
16199 			else
16200 				scaleup = V_tcp_autosndbuf_inc;
16201 			if (scaleup < V_tcp_autosndbuf_inc)
16202 				scaleup = V_tcp_autosndbuf_inc;
16203 			scaleup += so->so_snd.sb_hiwat;
16204 			if (scaleup > V_tcp_autosndbuf_max)
16205 				scaleup = V_tcp_autosndbuf_max;
16206 			if (!sbreserve_locked(so, SO_SND, scaleup, curthread))
16207 				so->so_snd.sb_flags &= ~SB_AUTOSIZE;
16208 		}
16209 	}
16210 }
16211 
16212 static int
16213 rack_fast_output(struct tcpcb *tp, struct tcp_rack *rack, uint64_t ts_val,
16214 		 uint32_t cts, uint32_t ms_cts, struct timeval *tv, long tot_len, int *send_err)
16215 {
16216 	/*
16217 	 * Enter to do fast output. We are given that the sched_pin is
16218 	 * in place (if accounting is compiled in) and the cycle count taken
16219 	 * at entry is in place in ts_val. The idea here is that
16220 	 * we know how many more bytes needs to be sent (presumably either
16221 	 * during pacing or to fill the cwnd and that was greater than
16222 	 * the max-burst). We have how much to send and all the info we
16223 	 * need to just send.
16224 	 */
16225 	struct ip *ip = NULL;
16226 	struct udphdr *udp = NULL;
16227 	struct tcphdr *th = NULL;
16228 	struct mbuf *m, *s_mb;
16229 	struct inpcb *inp;
16230 	uint8_t *cpto;
16231 	struct tcp_log_buffer *lgb;
16232 #ifdef TCP_ACCOUNTING
16233 	uint64_t crtsc;
16234 #endif
16235 	struct tcpopt to;
16236 	u_char opt[TCP_MAXOLEN];
16237 	uint32_t hdrlen, optlen;
16238 #ifdef TCP_ACCOUNTING
16239 	int cnt_thru = 1;
16240 #endif
16241 	int32_t slot, segsiz, len, max_val, tso = 0, sb_offset, error, ulen = 0;
16242 	uint16_t flags;
16243 	uint32_t s_soff;
16244 	uint32_t if_hw_tsomaxsegcount = 0, startseq;
16245 	uint32_t if_hw_tsomaxsegsize;
16246 	uint16_t add_flag = RACK_SENT_FP;
16247 #ifdef INET6
16248 	struct ip6_hdr *ip6 = NULL;
16249 
16250 	if (rack->r_is_v6) {
16251 		ip6 = (struct ip6_hdr *)rack->r_ctl.fsb.tcp_ip_hdr;
16252 		hdrlen = sizeof(struct ip6_hdr) + sizeof(struct tcphdr);
16253 	} else
16254 #endif				/* INET6 */
16255 	{
16256 		ip = (struct ip *)rack->r_ctl.fsb.tcp_ip_hdr;
16257 		hdrlen = sizeof(struct tcpiphdr);
16258 	}
16259 	if (tp->t_port && (V_tcp_udp_tunneling_port == 0)) {
16260 		m = NULL;
16261 		goto failed;
16262 	}
16263 	startseq = tp->snd_max;
16264 	segsiz = min(ctf_fixed_maxseg(tp), rack->r_ctl.rc_pace_min_segs);
16265 	inp = rack->rc_inp;
16266 	len = rack->r_ctl.fsb.left_to_send;
16267 	to.to_flags = 0;
16268 	flags = rack->r_ctl.fsb.tcp_flags;
16269 	if (tp->t_flags & TF_RCVD_TSTMP) {
16270 		to.to_tsval = ms_cts + tp->ts_offset;
16271 		to.to_tsecr = tp->ts_recent;
16272 		to.to_flags = TOF_TS;
16273 	}
16274 	optlen = tcp_addoptions(&to, opt);
16275 	hdrlen += optlen;
16276 	udp = rack->r_ctl.fsb.udp;
16277 	if (udp)
16278 		hdrlen += sizeof(struct udphdr);
16279 	if (rack->r_ctl.rc_pace_max_segs)
16280 		max_val = rack->r_ctl.rc_pace_max_segs;
16281 	else if (rack->rc_user_set_max_segs)
16282 		max_val = rack->rc_user_set_max_segs * segsiz;
16283 	else
16284 		max_val = len;
16285 	if ((tp->t_flags & TF_TSO) &&
16286 	    V_tcp_do_tso &&
16287 	    (len > segsiz) &&
16288 	    (tp->t_port == 0))
16289 		tso = 1;
16290 again:
16291 #ifdef INET6
16292 	if (MHLEN < hdrlen + max_linkhdr)
16293 		m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR);
16294 	else
16295 #endif
16296 		m = m_gethdr(M_NOWAIT, MT_DATA);
16297 	if (m == NULL)
16298 		goto failed;
16299 	m->m_data += max_linkhdr;
16300 	m->m_len = hdrlen;
16301 	th = rack->r_ctl.fsb.th;
16302 	/* Establish the len to send */
16303 	if (len > max_val)
16304 		len = max_val;
16305 	if ((tso) && (len + optlen > tp->t_maxseg)) {
16306 		uint32_t if_hw_tsomax;
16307 		int32_t max_len;
16308 
16309 		/* extract TSO information */
16310 		if_hw_tsomax = tp->t_tsomax;
16311 		if_hw_tsomaxsegcount = tp->t_tsomaxsegcount;
16312 		if_hw_tsomaxsegsize = tp->t_tsomaxsegsize;
16313 		/*
16314 		 * Check if we should limit by maximum payload
16315 		 * length:
16316 		 */
16317 		if (if_hw_tsomax != 0) {
16318 			/* compute maximum TSO length */
16319 			max_len = (if_hw_tsomax - hdrlen -
16320 				   max_linkhdr);
16321 			if (max_len <= 0) {
16322 				goto failed;
16323 			} else if (len > max_len) {
16324 				len = max_len;
16325 			}
16326 		}
16327 		if (len <= segsiz) {
16328 			/*
16329 			 * In case there are too many small fragments don't
16330 			 * use TSO:
16331 			 */
16332 			tso = 0;
16333 		}
16334 	} else {
16335 		tso = 0;
16336 	}
16337 	if ((tso == 0) && (len > segsiz))
16338 		len = segsiz;
16339 	if ((len == 0) ||
16340 	    (len <= MHLEN - hdrlen - max_linkhdr)) {
16341 		goto failed;
16342 	}
16343 	sb_offset = tp->snd_max - tp->snd_una;
16344 	th->th_seq = htonl(tp->snd_max);
16345 	th->th_ack = htonl(tp->rcv_nxt);
16346 	th->th_win = htons((u_short)(rack->r_ctl.fsb.recwin >> tp->rcv_scale));
16347 	if (th->th_win == 0) {
16348 		tp->t_sndzerowin++;
16349 		tp->t_flags |= TF_RXWIN0SENT;
16350 	} else
16351 		tp->t_flags &= ~TF_RXWIN0SENT;
16352 	tp->snd_up = tp->snd_una;	/* drag it along, its deprecated */
16353 	KMOD_TCPSTAT_INC(tcps_sndpack);
16354 	KMOD_TCPSTAT_ADD(tcps_sndbyte, len);
16355 #ifdef STATS
16356 	stats_voi_update_abs_u64(tp->t_stats, VOI_TCP_TXPB,
16357 				 len);
16358 #endif
16359 	if (rack->r_ctl.fsb.m == NULL)
16360 		goto failed;
16361 
16362 	/* s_mb and s_soff are saved for rack_log_output */
16363 	m->m_next = rack_fo_m_copym(rack, &len, if_hw_tsomaxsegcount, if_hw_tsomaxsegsize,
16364 				    &s_mb, &s_soff);
16365 	if (len <= segsiz) {
16366 		/*
16367 		 * Must have ran out of mbufs for the copy
16368 		 * shorten it to no longer need tso. Lets
16369 		 * not put on sendalot since we are low on
16370 		 * mbufs.
16371 		 */
16372 		tso = 0;
16373 	}
16374 	if (rack->r_ctl.fsb.rfo_apply_push &&
16375 	    (len == rack->r_ctl.fsb.left_to_send)) {
16376 		flags |= TH_PUSH;
16377 		add_flag |= RACK_HAD_PUSH;
16378 	}
16379 	if ((m->m_next == NULL) || (len <= 0)){
16380 		goto failed;
16381 	}
16382 	if (udp) {
16383 		if (rack->r_is_v6)
16384 			ulen = hdrlen + len - sizeof(struct ip6_hdr);
16385 		else
16386 			ulen = hdrlen + len - sizeof(struct ip);
16387 		udp->uh_ulen = htons(ulen);
16388 	}
16389 	m->m_pkthdr.rcvif = (struct ifnet *)0;
16390 	if (TCPS_HAVERCVDSYN(tp->t_state) &&
16391 	    (tp->t_flags2 & (TF2_ECN_PERMIT | TF2_ACE_PERMIT))) {
16392 		int ect = tcp_ecn_output_established(tp, &flags, len, false);
16393 		if ((tp->t_state == TCPS_SYN_RECEIVED) &&
16394 		    (tp->t_flags2 & TF2_ECN_SND_ECE))
16395 			tp->t_flags2 &= ~TF2_ECN_SND_ECE;
16396 #ifdef INET6
16397 		if (rack->r_is_v6) {
16398 			ip6->ip6_flow &= ~htonl(IPTOS_ECN_MASK << 20);
16399 			ip6->ip6_flow |= htonl(ect << 20);
16400 		}
16401 		else
16402 #endif
16403 		{
16404 			ip->ip_tos &= ~IPTOS_ECN_MASK;
16405 			ip->ip_tos |= ect;
16406 		}
16407 	}
16408 	tcp_set_flags(th, flags);
16409 	m->m_pkthdr.len = hdrlen + len;	/* in6_cksum() need this */
16410 #ifdef INET6
16411 	if (rack->r_is_v6) {
16412 		if (tp->t_port) {
16413 			m->m_pkthdr.csum_flags = CSUM_UDP_IPV6;
16414 			m->m_pkthdr.csum_data = offsetof(struct udphdr, uh_sum);
16415 			udp->uh_sum = in6_cksum_pseudo(ip6, ulen, IPPROTO_UDP, 0);
16416 			th->th_sum = htons(0);
16417 			UDPSTAT_INC(udps_opackets);
16418 		} else {
16419 			m->m_pkthdr.csum_flags = CSUM_TCP_IPV6;
16420 			m->m_pkthdr.csum_data = offsetof(struct tcphdr, th_sum);
16421 			th->th_sum = in6_cksum_pseudo(ip6,
16422 						      sizeof(struct tcphdr) + optlen + len, IPPROTO_TCP,
16423 						      0);
16424 		}
16425 	}
16426 #endif
16427 #if defined(INET6) && defined(INET)
16428 	else
16429 #endif
16430 #ifdef INET
16431 	{
16432 		if (tp->t_port) {
16433 			m->m_pkthdr.csum_flags = CSUM_UDP;
16434 			m->m_pkthdr.csum_data = offsetof(struct udphdr, uh_sum);
16435 			udp->uh_sum = in_pseudo(ip->ip_src.s_addr,
16436 						ip->ip_dst.s_addr, htons(ulen + IPPROTO_UDP));
16437 			th->th_sum = htons(0);
16438 			UDPSTAT_INC(udps_opackets);
16439 		} else {
16440 			m->m_pkthdr.csum_flags = CSUM_TCP;
16441 			m->m_pkthdr.csum_data = offsetof(struct tcphdr, th_sum);
16442 			th->th_sum = in_pseudo(ip->ip_src.s_addr,
16443 					       ip->ip_dst.s_addr, htons(sizeof(struct tcphdr) +
16444 									IPPROTO_TCP + len + optlen));
16445 		}
16446 		/* IP version must be set here for ipv4/ipv6 checking later */
16447 		KASSERT(ip->ip_v == IPVERSION,
16448 			("%s: IP version incorrect: %d", __func__, ip->ip_v));
16449 	}
16450 #endif
16451 	if (tso) {
16452 		KASSERT(len > tp->t_maxseg - optlen,
16453 			("%s: len <= tso_segsz tp:%p", __func__, tp));
16454 		m->m_pkthdr.csum_flags |= CSUM_TSO;
16455 		m->m_pkthdr.tso_segsz = tp->t_maxseg - optlen;
16456 	}
16457 #ifdef INET6
16458 	if (rack->r_is_v6) {
16459 		ip6->ip6_hlim = rack->r_ctl.fsb.hoplimit;
16460 		ip6->ip6_plen = htons(m->m_pkthdr.len - sizeof(*ip6));
16461 		if (V_path_mtu_discovery && tp->t_maxseg > V_tcp_minmss)
16462 			tp->t_flags2 |= TF2_PLPMTU_PMTUD;
16463 		else
16464 			tp->t_flags2 &= ~TF2_PLPMTU_PMTUD;
16465 	}
16466 #endif
16467 #if defined(INET) && defined(INET6)
16468 	else
16469 #endif
16470 #ifdef INET
16471 	{
16472 		ip->ip_len = htons(m->m_pkthdr.len);
16473 		ip->ip_ttl = rack->r_ctl.fsb.hoplimit;
16474 		if (V_path_mtu_discovery && tp->t_maxseg > V_tcp_minmss) {
16475 			tp->t_flags2 |= TF2_PLPMTU_PMTUD;
16476 			if (tp->t_port == 0 || len < V_tcp_minmss) {
16477 				ip->ip_off |= htons(IP_DF);
16478 			}
16479 		} else {
16480 			tp->t_flags2 &= ~TF2_PLPMTU_PMTUD;
16481 		}
16482 	}
16483 #endif
16484 	/* Time to copy in our header */
16485 	cpto = mtod(m, uint8_t *);
16486 	memcpy(cpto, rack->r_ctl.fsb.tcp_ip_hdr, rack->r_ctl.fsb.tcp_ip_hdr_len);
16487 	th = (struct tcphdr *)(cpto + ((uint8_t *)rack->r_ctl.fsb.th - rack->r_ctl.fsb.tcp_ip_hdr));
16488 	if (optlen) {
16489 		bcopy(opt, th + 1, optlen);
16490 		th->th_off = (sizeof(struct tcphdr) + optlen) >> 2;
16491 	} else {
16492 		th->th_off = sizeof(struct tcphdr) >> 2;
16493 	}
16494 	if (tp->t_logstate != TCP_LOG_STATE_OFF) {
16495 		union tcp_log_stackspecific log;
16496 
16497 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
16498 		log.u_bbr.inhpts = tcp_in_hpts(rack->rc_inp);
16499 		if (rack->rack_no_prr)
16500 			log.u_bbr.flex1 = 0;
16501 		else
16502 			log.u_bbr.flex1 = rack->r_ctl.rc_prr_sndcnt;
16503 		log.u_bbr.flex2 = rack->r_ctl.rc_pace_min_segs;
16504 		log.u_bbr.flex3 = rack->r_ctl.rc_pace_max_segs;
16505 		log.u_bbr.flex4 = max_val;
16506 		log.u_bbr.flex5 = 0;
16507 		/* Save off the early/late values */
16508 		log.u_bbr.flex6 = rack->r_ctl.rc_agg_early;
16509 		log.u_bbr.applimited = rack->r_ctl.rc_agg_delayed;
16510 		log.u_bbr.bw_inuse = rack_get_bw(rack);
16511 		log.u_bbr.flex8 = 0;
16512 		log.u_bbr.pacing_gain = rack_get_output_gain(rack, NULL);
16513 		log.u_bbr.flex7 = 44;
16514 		log.u_bbr.pkts_out = tp->t_maxseg;
16515 		log.u_bbr.timeStamp = cts;
16516 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
16517 		log.u_bbr.lt_epoch = rack->r_ctl.cwnd_to_use;
16518 		log.u_bbr.delivered = 0;
16519 		lgb = tcp_log_event_(tp, th, NULL, NULL, TCP_LOG_OUT, ERRNO_UNK,
16520 				     len, &log, false, NULL, NULL, 0, tv);
16521 	} else
16522 		lgb = NULL;
16523 #ifdef INET6
16524 	if (rack->r_is_v6) {
16525 		error = ip6_output(m, NULL,
16526 				   &inp->inp_route6,
16527 				   0, NULL, NULL, inp);
16528 	}
16529 #endif
16530 #if defined(INET) && defined(INET6)
16531 	else
16532 #endif
16533 #ifdef INET
16534 	{
16535 		error = ip_output(m, NULL,
16536 				  &inp->inp_route,
16537 				  0, 0, inp);
16538 	}
16539 #endif
16540 	if (lgb) {
16541 		lgb->tlb_errno = error;
16542 		lgb = NULL;
16543 	}
16544 	if (error) {
16545 		*send_err = error;
16546 		m = NULL;
16547 		goto failed;
16548 	}
16549 	rack_log_output(tp, &to, len, tp->snd_max, flags, error, rack_to_usec_ts(tv),
16550 			NULL, add_flag, s_mb, s_soff, rack->r_ctl.fsb.hw_tls);
16551 	m = NULL;
16552 	if (tp->snd_una == tp->snd_max) {
16553 		rack->r_ctl.rc_tlp_rxt_last_time = cts;
16554 		rack_log_progress_event(rack, tp, ticks, PROGRESS_START, __LINE__);
16555 		tp->t_acktime = ticks;
16556 	}
16557 	if (error == 0)
16558 		tcp_account_for_send(tp, len, 0, 0, rack->r_ctl.fsb.hw_tls);
16559 
16560 	rack->forced_ack = 0;	/* If we send something zap the FA flag */
16561 	tot_len += len;
16562 	if ((tp->t_flags & TF_GPUTINPROG) == 0)
16563 		rack_start_gp_measurement(tp, rack, tp->snd_max, sb_offset);
16564 	tp->snd_max += len;
16565 	tp->snd_nxt = tp->snd_max;
16566 	{
16567 		int idx;
16568 
16569 		idx = (len / segsiz) + 3;
16570 		if (idx >= TCP_MSS_ACCT_ATIMER)
16571 			counter_u64_add(rack_out_size[(TCP_MSS_ACCT_ATIMER-1)], 1);
16572 		else
16573 			counter_u64_add(rack_out_size[idx], 1);
16574 	}
16575 	if (len <= rack->r_ctl.fsb.left_to_send)
16576 		rack->r_ctl.fsb.left_to_send -= len;
16577 	else
16578 		rack->r_ctl.fsb.left_to_send = 0;
16579 	if (rack->r_ctl.fsb.left_to_send < segsiz) {
16580 		rack->r_fast_output = 0;
16581 		rack->r_ctl.fsb.left_to_send = 0;
16582 		/* At the end of fast_output scale up the sb */
16583 		SOCKBUF_LOCK(&rack->rc_inp->inp_socket->so_snd);
16584 		rack_sndbuf_autoscale(rack);
16585 		SOCKBUF_UNLOCK(&rack->rc_inp->inp_socket->so_snd);
16586 	}
16587 	if (tp->t_rtttime == 0) {
16588 		tp->t_rtttime = ticks;
16589 		tp->t_rtseq = startseq;
16590 		KMOD_TCPSTAT_INC(tcps_segstimed);
16591 	}
16592 	if ((rack->r_ctl.fsb.left_to_send >= segsiz) &&
16593 	    (max_val > len) &&
16594 	    (tso == 0)) {
16595 		max_val -= len;
16596 		len = segsiz;
16597 		th = rack->r_ctl.fsb.th;
16598 #ifdef TCP_ACCOUNTING
16599 		cnt_thru++;
16600 #endif
16601 		goto again;
16602 	}
16603 	tp->t_flags &= ~(TF_ACKNOW | TF_DELACK);
16604 	counter_u64_add(rack_fto_send, 1);
16605 	slot = rack_get_pacing_delay(rack, tp, tot_len, NULL, segsiz);
16606 	rack_start_hpts_timer(rack, tp, cts, slot, tot_len, 0);
16607 #ifdef TCP_ACCOUNTING
16608 	crtsc = get_cyclecount();
16609 	if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
16610 		tp->tcp_cnt_counters[SND_OUT_DATA] += cnt_thru;
16611 	}
16612 	counter_u64_add(tcp_cnt_counters[SND_OUT_DATA], cnt_thru);
16613 	if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
16614 		tp->tcp_proc_time[SND_OUT_DATA] += (crtsc - ts_val);
16615 	}
16616 	counter_u64_add(tcp_proc_time[SND_OUT_DATA], (crtsc - ts_val));
16617 	if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
16618 		tp->tcp_cnt_counters[CNT_OF_MSS_OUT] += ((tot_len + segsiz - 1) / segsiz);
16619 	}
16620 	counter_u64_add(tcp_cnt_counters[CNT_OF_MSS_OUT], ((tot_len + segsiz - 1) / segsiz));
16621 	sched_unpin();
16622 #endif
16623 	return (0);
16624 failed:
16625 	if (m)
16626 		m_free(m);
16627 	rack->r_fast_output = 0;
16628 	return (-1);
16629 }
16630 
16631 static struct rack_sendmap *
16632 rack_check_collapsed(struct tcp_rack *rack, uint32_t cts)
16633 {
16634 	struct rack_sendmap *rsm = NULL;
16635 	struct rack_sendmap fe;
16636 	int thresh;
16637 
16638 restart:
16639 	fe.r_start = rack->r_ctl.last_collapse_point;
16640 	rsm = RB_FIND(rack_rb_tree_head, &rack->r_ctl.rc_mtree, &fe);
16641 	if ((rsm == NULL) || ((rsm->r_flags & RACK_RWND_COLLAPSED) == 0)) {
16642 		/* Nothing, strange turn off validity  */
16643 		rack->r_collapse_point_valid = 0;
16644 		return (NULL);
16645 	}
16646 	/* Can we send it yet? */
16647 	if (rsm->r_end > (rack->rc_tp->snd_una + rack->rc_tp->snd_wnd)) {
16648 		/*
16649 		 * Receiver window has not grown enough for
16650 		 * the segment to be put on the wire.
16651 		 */
16652 		return (NULL);
16653 	}
16654 	if (rsm->r_flags & RACK_ACKED) {
16655 		/*
16656 		 * It has been sacked, lets move to the
16657 		 * next one if possible.
16658 		 */
16659 		rack->r_ctl.last_collapse_point = rsm->r_end;
16660 		/* Are we done? */
16661 		if (SEQ_GEQ(rack->r_ctl.last_collapse_point,
16662 			    rack->r_ctl.high_collapse_point)) {
16663 			rack->r_collapse_point_valid = 0;
16664 			return (NULL);
16665 		}
16666 		goto restart;
16667 	}
16668 	/* Now has it been long enough ? */
16669 	thresh = rack_calc_thresh_rack(rack, rack_grab_rtt(rack->rc_tp, rack), cts);
16670 	if ((cts - ((uint32_t)rsm->r_tim_lastsent[(rsm->r_rtr_cnt-1)])) > thresh) {
16671 		rack_log_collapse(rack, rsm->r_start,
16672 				  (cts - ((uint32_t)rsm->r_tim_lastsent[(rsm->r_rtr_cnt-1)])),
16673 				  thresh, __LINE__, 6, rsm->r_flags, rsm);
16674 		return (rsm);
16675 	}
16676 	/* Not enough time */
16677 	rack_log_collapse(rack, rsm->r_start,
16678 			  (cts - ((uint32_t)rsm->r_tim_lastsent[(rsm->r_rtr_cnt-1)])),
16679 			  thresh, __LINE__, 7, rsm->r_flags, rsm);
16680 	return (NULL);
16681 }
16682 
16683 static int
16684 rack_output(struct tcpcb *tp)
16685 {
16686 	struct socket *so;
16687 	uint32_t recwin;
16688 	uint32_t sb_offset, s_moff = 0;
16689 	int32_t len, error = 0;
16690 	uint16_t flags;
16691 	struct mbuf *m, *s_mb = NULL;
16692 	struct mbuf *mb;
16693 	uint32_t if_hw_tsomaxsegcount = 0;
16694 	uint32_t if_hw_tsomaxsegsize;
16695 	int32_t segsiz, minseg;
16696 	long tot_len_this_send = 0;
16697 #ifdef INET
16698 	struct ip *ip = NULL;
16699 #endif
16700 	struct udphdr *udp = NULL;
16701 	struct tcp_rack *rack;
16702 	struct tcphdr *th;
16703 	uint8_t pass = 0;
16704 	uint8_t mark = 0;
16705 	uint8_t wanted_cookie = 0;
16706 	u_char opt[TCP_MAXOLEN];
16707 	unsigned ipoptlen, optlen, hdrlen, ulen=0;
16708 	uint32_t rack_seq;
16709 
16710 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
16711 	unsigned ipsec_optlen = 0;
16712 
16713 #endif
16714 	int32_t idle, sendalot;
16715 	int32_t sub_from_prr = 0;
16716 	volatile int32_t sack_rxmit;
16717 	struct rack_sendmap *rsm = NULL;
16718 	int32_t tso, mtu;
16719 	struct tcpopt to;
16720 	int32_t slot = 0;
16721 	int32_t sup_rack = 0;
16722 	uint32_t cts, ms_cts, delayed, early;
16723 	uint16_t add_flag = RACK_SENT_SP;
16724 	/* The doing_tlp flag will be set by the actual rack_timeout_tlp() */
16725 	uint8_t hpts_calling,  doing_tlp = 0;
16726 	uint32_t cwnd_to_use, pace_max_seg;
16727 	int32_t do_a_prefetch = 0;
16728 	int32_t prefetch_rsm = 0;
16729 	int32_t orig_len = 0;
16730 	struct timeval tv;
16731 	int32_t prefetch_so_done = 0;
16732 	struct tcp_log_buffer *lgb;
16733 	struct inpcb *inp;
16734 	struct sockbuf *sb;
16735 	uint64_t ts_val = 0;
16736 #ifdef TCP_ACCOUNTING
16737 	uint64_t crtsc;
16738 #endif
16739 #ifdef INET6
16740 	struct ip6_hdr *ip6 = NULL;
16741 	int32_t isipv6;
16742 #endif
16743 	bool hw_tls = false;
16744 
16745 	/* setup and take the cache hits here */
16746 	rack = (struct tcp_rack *)tp->t_fb_ptr;
16747 #ifdef TCP_ACCOUNTING
16748 	sched_pin();
16749 	ts_val = get_cyclecount();
16750 #endif
16751 	hpts_calling = rack->rc_inp->inp_hpts_calls;
16752 	NET_EPOCH_ASSERT();
16753 	INP_WLOCK_ASSERT(rack->rc_inp);
16754 #ifdef TCP_OFFLOAD
16755 	if (tp->t_flags & TF_TOE) {
16756 #ifdef TCP_ACCOUNTING
16757 		sched_unpin();
16758 #endif
16759 		return (tcp_offload_output(tp));
16760 	}
16761 #endif
16762 	/*
16763 	 * For TFO connections in SYN_RECEIVED, only allow the initial
16764 	 * SYN|ACK and those sent by the retransmit timer.
16765 	 */
16766 	if (IS_FASTOPEN(tp->t_flags) &&
16767 	    (tp->t_state == TCPS_SYN_RECEIVED) &&
16768 	    SEQ_GT(tp->snd_max, tp->snd_una) &&    /* initial SYN|ACK sent */
16769 	    (rack->r_ctl.rc_resend == NULL)) {         /* not a retransmit */
16770 #ifdef TCP_ACCOUNTING
16771 		sched_unpin();
16772 #endif
16773 		return (0);
16774 	}
16775 #ifdef INET6
16776 	if (rack->r_state) {
16777 		/* Use the cache line loaded if possible */
16778 		isipv6 = rack->r_is_v6;
16779 	} else {
16780 		isipv6 = (rack->rc_inp->inp_vflag & INP_IPV6) != 0;
16781 	}
16782 #endif
16783 	early = 0;
16784 	cts = tcp_get_usecs(&tv);
16785 	ms_cts = tcp_tv_to_mssectick(&tv);
16786 	if (((rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT) == 0) &&
16787 	    tcp_in_hpts(rack->rc_inp)) {
16788 		/*
16789 		 * We are on the hpts for some timer but not hptsi output.
16790 		 * Remove from the hpts unconditionally.
16791 		 */
16792 		rack_timer_cancel(tp, rack, cts, __LINE__);
16793 	}
16794 	/* Are we pacing and late? */
16795 	if ((rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT) &&
16796 	    TSTMP_GEQ(cts, rack->r_ctl.rc_last_output_to)) {
16797 		/* We are delayed */
16798 		delayed = cts - rack->r_ctl.rc_last_output_to;
16799 	} else {
16800 		delayed = 0;
16801 	}
16802 	/* Do the timers, which may override the pacer */
16803 	if (rack->r_ctl.rc_hpts_flags & PACE_TMR_MASK) {
16804 		int retval;
16805 
16806 		retval = rack_process_timers(tp, rack, cts, hpts_calling,
16807 		    &doing_tlp);
16808 		if (retval != 0) {
16809 			counter_u64_add(rack_out_size[TCP_MSS_ACCT_ATIMER], 1);
16810 #ifdef TCP_ACCOUNTING
16811 			sched_unpin();
16812 #endif
16813 			/*
16814 			 * If timers want tcp_drop(), then pass error out,
16815 			 * otherwise suppress it.
16816 			 */
16817 			return (retval < 0 ? retval : 0);
16818 		}
16819 	}
16820 	if (rack->rc_in_persist) {
16821 		if (tcp_in_hpts(rack->rc_inp) == 0) {
16822 			/* Timer is not running */
16823 			rack_start_hpts_timer(rack, tp, cts, 0, 0, 0);
16824 		}
16825 #ifdef TCP_ACCOUNTING
16826 		sched_unpin();
16827 #endif
16828 		return (0);
16829 	}
16830 	if ((rack->rc_ack_required == 1) &&
16831 	    (rack->r_timer_override == 0)){
16832 		/* A timeout occurred and no ack has arrived */
16833 		if (tcp_in_hpts(rack->rc_inp) == 0) {
16834 			/* Timer is not running */
16835 			rack_start_hpts_timer(rack, tp, cts, 0, 0, 0);
16836 		}
16837 #ifdef TCP_ACCOUNTING
16838 		sched_unpin();
16839 #endif
16840 		return (0);
16841 	}
16842 	if ((rack->r_timer_override) ||
16843 	    (rack->rc_ack_can_sendout_data) ||
16844 	    (delayed) ||
16845 	    (tp->t_state < TCPS_ESTABLISHED)) {
16846 		rack->rc_ack_can_sendout_data = 0;
16847 		if (tcp_in_hpts(rack->rc_inp))
16848 			tcp_hpts_remove(rack->rc_inp);
16849 	} else if (tcp_in_hpts(rack->rc_inp)) {
16850 		/*
16851 		 * On the hpts you can't pass even if ACKNOW is on, we will
16852 		 * when the hpts fires.
16853 		 */
16854 #ifdef TCP_ACCOUNTING
16855 		crtsc = get_cyclecount();
16856 		if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
16857 			tp->tcp_proc_time[SND_BLOCKED] += (crtsc - ts_val);
16858 		}
16859 		counter_u64_add(tcp_proc_time[SND_BLOCKED], (crtsc - ts_val));
16860 		if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
16861 			tp->tcp_cnt_counters[SND_BLOCKED]++;
16862 		}
16863 		counter_u64_add(tcp_cnt_counters[SND_BLOCKED], 1);
16864 		sched_unpin();
16865 #endif
16866 		counter_u64_add(rack_out_size[TCP_MSS_ACCT_INPACE], 1);
16867 		return (0);
16868 	}
16869 	rack->rc_inp->inp_hpts_calls = 0;
16870 	/* Finish out both pacing early and late accounting */
16871 	if ((rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT) &&
16872 	    TSTMP_GT(rack->r_ctl.rc_last_output_to, cts)) {
16873 		early = rack->r_ctl.rc_last_output_to - cts;
16874 	} else
16875 		early = 0;
16876 	if (delayed) {
16877 		rack->r_ctl.rc_agg_delayed += delayed;
16878 		rack->r_late = 1;
16879 	} else if (early) {
16880 		rack->r_ctl.rc_agg_early += early;
16881 		rack->r_early = 1;
16882 	}
16883 	/* Now that early/late accounting is done turn off the flag */
16884 	rack->r_ctl.rc_hpts_flags &= ~PACE_PKT_OUTPUT;
16885 	rack->r_wanted_output = 0;
16886 	rack->r_timer_override = 0;
16887 	if ((tp->t_state != rack->r_state) &&
16888 	    TCPS_HAVEESTABLISHED(tp->t_state)) {
16889 		rack_set_state(tp, rack);
16890 	}
16891 	if ((rack->r_fast_output) &&
16892 	    (doing_tlp == 0) &&
16893 	    (tp->rcv_numsacks == 0)) {
16894 		int ret;
16895 
16896 		error = 0;
16897 		ret = rack_fast_output(tp, rack, ts_val, cts, ms_cts, &tv, tot_len_this_send, &error);
16898 		if (ret >= 0)
16899 			return(ret);
16900 		else if (error) {
16901 			inp = rack->rc_inp;
16902 			so = inp->inp_socket;
16903 			sb = &so->so_snd;
16904 			goto nomore;
16905 		}
16906 	}
16907 	inp = rack->rc_inp;
16908 	/*
16909 	 * For TFO connections in SYN_SENT or SYN_RECEIVED,
16910 	 * only allow the initial SYN or SYN|ACK and those sent
16911 	 * by the retransmit timer.
16912 	 */
16913 	if (IS_FASTOPEN(tp->t_flags) &&
16914 	    ((tp->t_state == TCPS_SYN_RECEIVED) ||
16915 	     (tp->t_state == TCPS_SYN_SENT)) &&
16916 	    SEQ_GT(tp->snd_max, tp->snd_una) && /* initial SYN or SYN|ACK sent */
16917 	    (tp->t_rxtshift == 0)) {              /* not a retransmit */
16918 		cwnd_to_use = rack->r_ctl.cwnd_to_use = tp->snd_cwnd;
16919 		so = inp->inp_socket;
16920 		sb = &so->so_snd;
16921 		goto just_return_nolock;
16922 	}
16923 	/*
16924 	 * Determine length of data that should be transmitted, and flags
16925 	 * that will be used. If there is some data or critical controls
16926 	 * (SYN, RST) to send, then transmit; otherwise, investigate
16927 	 * further.
16928 	 */
16929 	idle = (tp->t_flags & TF_LASTIDLE) || (tp->snd_max == tp->snd_una);
16930 	if (tp->t_idle_reduce) {
16931 		if (idle && (TICKS_2_USEC(ticks - tp->t_rcvtime) >= tp->t_rxtcur))
16932 			rack_cc_after_idle(rack, tp);
16933 	}
16934 	tp->t_flags &= ~TF_LASTIDLE;
16935 	if (idle) {
16936 		if (tp->t_flags & TF_MORETOCOME) {
16937 			tp->t_flags |= TF_LASTIDLE;
16938 			idle = 0;
16939 		}
16940 	}
16941 	if ((tp->snd_una == tp->snd_max) &&
16942 	    rack->r_ctl.rc_went_idle_time &&
16943 	    TSTMP_GT(cts, rack->r_ctl.rc_went_idle_time)) {
16944 		idle = cts - rack->r_ctl.rc_went_idle_time;
16945 		if (idle > rack_min_probertt_hold) {
16946 			/* Count as a probe rtt */
16947 			if (rack->in_probe_rtt == 0) {
16948 				rack->r_ctl.rc_lower_rtt_us_cts = cts;
16949 				rack->r_ctl.rc_time_probertt_entered = rack->r_ctl.rc_lower_rtt_us_cts;
16950 				rack->r_ctl.rc_time_probertt_starts = rack->r_ctl.rc_lower_rtt_us_cts;
16951 				rack->r_ctl.rc_time_of_last_probertt = rack->r_ctl.rc_lower_rtt_us_cts;
16952 			} else {
16953 				rack_exit_probertt(rack, cts);
16954 			}
16955 		}
16956 		idle = 0;
16957 	}
16958 	if (rack_use_fsb && (rack->r_fsb_inited == 0) && (rack->r_state != TCPS_CLOSED))
16959 		rack_init_fsb_block(tp, rack);
16960 again:
16961 	/*
16962 	 * If we've recently taken a timeout, snd_max will be greater than
16963 	 * snd_nxt.  There may be SACK information that allows us to avoid
16964 	 * resending already delivered data.  Adjust snd_nxt accordingly.
16965 	 */
16966 	sendalot = 0;
16967 	cts = tcp_get_usecs(&tv);
16968 	ms_cts = tcp_tv_to_mssectick(&tv);
16969 	tso = 0;
16970 	mtu = 0;
16971 	segsiz = min(ctf_fixed_maxseg(tp), rack->r_ctl.rc_pace_min_segs);
16972 	minseg = segsiz;
16973 	if (rack->r_ctl.rc_pace_max_segs == 0)
16974 		pace_max_seg = rack->rc_user_set_max_segs * segsiz;
16975 	else
16976 		pace_max_seg = rack->r_ctl.rc_pace_max_segs;
16977 	sb_offset = tp->snd_max - tp->snd_una;
16978 	cwnd_to_use = rack->r_ctl.cwnd_to_use = tp->snd_cwnd;
16979 	flags = tcp_outflags[tp->t_state];
16980 	while (rack->rc_free_cnt < rack_free_cache) {
16981 		rsm = rack_alloc(rack);
16982 		if (rsm == NULL) {
16983 			if (inp->inp_hpts_calls)
16984 				/* Retry in a ms */
16985 				slot = (1 * HPTS_USEC_IN_MSEC);
16986 			so = inp->inp_socket;
16987 			sb = &so->so_snd;
16988 			goto just_return_nolock;
16989 		}
16990 		TAILQ_INSERT_TAIL(&rack->r_ctl.rc_free, rsm, r_tnext);
16991 		rack->rc_free_cnt++;
16992 		rsm = NULL;
16993 	}
16994 	if (inp->inp_hpts_calls)
16995 		inp->inp_hpts_calls = 0;
16996 	sack_rxmit = 0;
16997 	len = 0;
16998 	rsm = NULL;
16999 	if (flags & TH_RST) {
17000 		SOCKBUF_LOCK(&inp->inp_socket->so_snd);
17001 		so = inp->inp_socket;
17002 		sb = &so->so_snd;
17003 		goto send;
17004 	}
17005 	if (rack->r_ctl.rc_resend) {
17006 		/* Retransmit timer */
17007 		rsm = rack->r_ctl.rc_resend;
17008 		rack->r_ctl.rc_resend = NULL;
17009 		len = rsm->r_end - rsm->r_start;
17010 		sack_rxmit = 1;
17011 		sendalot = 0;
17012 		KASSERT(SEQ_LEQ(tp->snd_una, rsm->r_start),
17013 			("%s:%d: r.start:%u < SND.UNA:%u; tp:%p, rack:%p, rsm:%p",
17014 			 __func__, __LINE__,
17015 			 rsm->r_start, tp->snd_una, tp, rack, rsm));
17016 		sb_offset = rsm->r_start - tp->snd_una;
17017 		if (len >= segsiz)
17018 			len = segsiz;
17019 	} else if (rack->r_collapse_point_valid &&
17020 		   ((rsm = rack_check_collapsed(rack, cts)) != NULL)) {
17021 		/*
17022 		 * If an RSM is returned then enough time has passed
17023 		 * for us to retransmit it. Move up the collapse point,
17024 		 * since this rsm has its chance to retransmit now.
17025 		 */
17026 		rack_trace_point(rack, RACK_TP_COLLAPSED_RXT);
17027 		rack->r_ctl.last_collapse_point = rsm->r_end;
17028 		/* Are we done? */
17029 		if (SEQ_GEQ(rack->r_ctl.last_collapse_point,
17030 			    rack->r_ctl.high_collapse_point))
17031 			rack->r_collapse_point_valid = 0;
17032 		sack_rxmit = 1;
17033 		/* We are not doing a TLP */
17034 		doing_tlp = 0;
17035 		len = rsm->r_end - rsm->r_start;
17036 		sb_offset = rsm->r_start - tp->snd_una;
17037 		sendalot = 0;
17038 		if ((rack->full_size_rxt == 0) &&
17039 		    (rack->shape_rxt_to_pacing_min == 0) &&
17040 		    (len >= segsiz))
17041 			len = segsiz;
17042 	} else if ((rsm = tcp_rack_output(tp, rack, cts)) != NULL) {
17043 		/* We have a retransmit that takes precedence */
17044 		if ((!IN_FASTRECOVERY(tp->t_flags)) &&
17045 		    ((rsm->r_flags & RACK_MUST_RXT) == 0) &&
17046 		    ((tp->t_flags & TF_WASFRECOVERY) == 0)) {
17047 			/* Enter recovery if not induced by a time-out */
17048 			rack_cong_signal(tp, CC_NDUPACK, tp->snd_una, __LINE__);
17049 		}
17050 #ifdef INVARIANTS
17051 		if (SEQ_LT(rsm->r_start, tp->snd_una)) {
17052 			panic("Huh, tp:%p rack:%p rsm:%p start:%u < snd_una:%u\n",
17053 			      tp, rack, rsm, rsm->r_start, tp->snd_una);
17054 		}
17055 #endif
17056 		len = rsm->r_end - rsm->r_start;
17057 		KASSERT(SEQ_LEQ(tp->snd_una, rsm->r_start),
17058 			("%s:%d: r.start:%u < SND.UNA:%u; tp:%p, rack:%p, rsm:%p",
17059 			 __func__, __LINE__,
17060 			 rsm->r_start, tp->snd_una, tp, rack, rsm));
17061 		sb_offset = rsm->r_start - tp->snd_una;
17062 		sendalot = 0;
17063 		if (len >= segsiz)
17064 			len = segsiz;
17065 		if (len > 0) {
17066 			sack_rxmit = 1;
17067 			KMOD_TCPSTAT_INC(tcps_sack_rexmits);
17068 			KMOD_TCPSTAT_ADD(tcps_sack_rexmit_bytes,
17069 			    min(len, segsiz));
17070 		}
17071 	} else if (rack->r_ctl.rc_tlpsend) {
17072 		/* Tail loss probe */
17073 		long cwin;
17074 		long tlen;
17075 
17076 		/*
17077 		 * Check if we can do a TLP with a RACK'd packet
17078 		 * this can happen if we are not doing the rack
17079 		 * cheat and we skipped to a TLP and it
17080 		 * went off.
17081 		 */
17082 		rsm = rack->r_ctl.rc_tlpsend;
17083 		/* We are doing a TLP make sure the flag is preent */
17084 		rsm->r_flags |= RACK_TLP;
17085 		rack->r_ctl.rc_tlpsend = NULL;
17086 		sack_rxmit = 1;
17087 		tlen = rsm->r_end - rsm->r_start;
17088 		if (tlen > segsiz)
17089 			tlen = segsiz;
17090 		KASSERT(SEQ_LEQ(tp->snd_una, rsm->r_start),
17091 			("%s:%d: r.start:%u < SND.UNA:%u; tp:%p, rack:%p, rsm:%p",
17092 			 __func__, __LINE__,
17093 			 rsm->r_start, tp->snd_una, tp, rack, rsm));
17094 		sb_offset = rsm->r_start - tp->snd_una;
17095 		cwin = min(tp->snd_wnd, tlen);
17096 		len = cwin;
17097 	}
17098 	if (rack->r_must_retran &&
17099 	    (doing_tlp == 0) &&
17100 	    (SEQ_GT(tp->snd_max, tp->snd_una)) &&
17101 	    (rsm == NULL)) {
17102 		/*
17103 		 * There are two different ways that we
17104 		 * can get into this block:
17105 		 * a) This is a non-sack connection, we had a time-out
17106 		 *    and thus r_must_retran was set and everything
17107 		 *    left outstanding as been marked for retransmit.
17108 		 * b) The MTU of the path shrank, so that everything
17109 		 *    was marked to be retransmitted with the smaller
17110 		 *    mtu and r_must_retran was set.
17111 		 *
17112 		 * This means that we expect the sendmap (outstanding)
17113 		 * to all be marked must. We can use the tmap to
17114 		 * look at them.
17115 		 *
17116 		 */
17117 		int sendwin, flight;
17118 
17119 		sendwin = min(tp->snd_wnd, tp->snd_cwnd);
17120 		flight = ctf_flight_size(tp, rack->r_ctl.rc_out_at_rto);
17121 		if (flight >= sendwin) {
17122 			/*
17123 			 * We can't send yet.
17124 			 */
17125 			so = inp->inp_socket;
17126 			sb = &so->so_snd;
17127 			goto just_return_nolock;
17128 		}
17129 		/*
17130 		 * This is the case a/b mentioned above. All
17131 		 * outstanding/not-acked should be marked.
17132 		 * We can use the tmap to find them.
17133 		 */
17134 		rsm = TAILQ_FIRST(&rack->r_ctl.rc_tmap);
17135 		if (rsm == NULL) {
17136 			/* TSNH */
17137 			rack->r_must_retran = 0;
17138 			rack->r_ctl.rc_out_at_rto = 0;
17139 			so = inp->inp_socket;
17140 			sb = &so->so_snd;
17141 			goto just_return_nolock;
17142 		}
17143 		if ((rsm->r_flags & RACK_MUST_RXT) == 0) {
17144 			/*
17145 			 * The first one does not have the flag, did we collapse
17146 			 * further up in our list?
17147 			 */
17148 			rack->r_must_retran = 0;
17149 			rack->r_ctl.rc_out_at_rto = 0;
17150 			rsm = NULL;
17151 			sack_rxmit = 0;
17152 		} else {
17153 			sack_rxmit = 1;
17154 			len = rsm->r_end - rsm->r_start;
17155 			sb_offset = rsm->r_start - tp->snd_una;
17156 			sendalot = 0;
17157 			if ((rack->full_size_rxt == 0) &&
17158 			    (rack->shape_rxt_to_pacing_min == 0) &&
17159 			    (len >= segsiz))
17160 				len = segsiz;
17161 			/*
17162 			 * Delay removing the flag RACK_MUST_RXT so
17163 			 * that the fastpath for retransmit will
17164 			 * work with this rsm.
17165 			 */
17166 		}
17167 	}
17168 	/*
17169 	 * Enforce a connection sendmap count limit if set
17170 	 * as long as we are not retransmiting.
17171 	 */
17172 	if ((rsm == NULL) &&
17173 	    (rack->do_detection == 0) &&
17174 	    (V_tcp_map_entries_limit > 0) &&
17175 	    (rack->r_ctl.rc_num_maps_alloced >= V_tcp_map_entries_limit)) {
17176 		counter_u64_add(rack_to_alloc_limited, 1);
17177 		if (!rack->alloc_limit_reported) {
17178 			rack->alloc_limit_reported = 1;
17179 			counter_u64_add(rack_alloc_limited_conns, 1);
17180 		}
17181 		so = inp->inp_socket;
17182 		sb = &so->so_snd;
17183 		goto just_return_nolock;
17184 	}
17185 	if (rsm && (rsm->r_flags & RACK_HAS_FIN)) {
17186 		/* we are retransmitting the fin */
17187 		len--;
17188 		if (len) {
17189 			/*
17190 			 * When retransmitting data do *not* include the
17191 			 * FIN. This could happen from a TLP probe.
17192 			 */
17193 			flags &= ~TH_FIN;
17194 		}
17195 	}
17196 	if (rsm && rack->r_fsb_inited && rack_use_rsm_rfo &&
17197 	    ((rsm->r_flags & RACK_HAS_FIN) == 0)) {
17198 		int ret;
17199 
17200 		ret = rack_fast_rsm_output(tp, rack, rsm, ts_val, cts, ms_cts, &tv, len, doing_tlp);
17201 		if (ret == 0)
17202 			return (0);
17203 	}
17204 	so = inp->inp_socket;
17205 	sb = &so->so_snd;
17206 	if (do_a_prefetch == 0) {
17207 		kern_prefetch(sb, &do_a_prefetch);
17208 		do_a_prefetch = 1;
17209 	}
17210 #ifdef NETFLIX_SHARED_CWND
17211 	if ((tp->t_flags2 & TF2_TCP_SCWND_ALLOWED) &&
17212 	    rack->rack_enable_scwnd) {
17213 		/* We are doing cwnd sharing */
17214 		if (rack->gp_ready &&
17215 		    (rack->rack_attempted_scwnd == 0) &&
17216 		    (rack->r_ctl.rc_scw == NULL) &&
17217 		    tp->t_lib) {
17218 			/* The pcbid is in, lets make an attempt */
17219 			counter_u64_add(rack_try_scwnd, 1);
17220 			rack->rack_attempted_scwnd = 1;
17221 			rack->r_ctl.rc_scw = tcp_shared_cwnd_alloc(tp,
17222 								   &rack->r_ctl.rc_scw_index,
17223 								   segsiz);
17224 		}
17225 		if (rack->r_ctl.rc_scw &&
17226 		    (rack->rack_scwnd_is_idle == 1) &&
17227 		    sbavail(&so->so_snd)) {
17228 			/* we are no longer out of data */
17229 			tcp_shared_cwnd_active(rack->r_ctl.rc_scw, rack->r_ctl.rc_scw_index);
17230 			rack->rack_scwnd_is_idle = 0;
17231 		}
17232 		if (rack->r_ctl.rc_scw) {
17233 			/* First lets update and get the cwnd */
17234 			rack->r_ctl.cwnd_to_use = cwnd_to_use = tcp_shared_cwnd_update(rack->r_ctl.rc_scw,
17235 								    rack->r_ctl.rc_scw_index,
17236 								    tp->snd_cwnd, tp->snd_wnd, segsiz);
17237 		}
17238 	}
17239 #endif
17240 	/*
17241 	 * Get standard flags, and add SYN or FIN if requested by 'hidden'
17242 	 * state flags.
17243 	 */
17244 	if (tp->t_flags & TF_NEEDFIN)
17245 		flags |= TH_FIN;
17246 	if (tp->t_flags & TF_NEEDSYN)
17247 		flags |= TH_SYN;
17248 	if ((sack_rxmit == 0) && (prefetch_rsm == 0)) {
17249 		void *end_rsm;
17250 		end_rsm = TAILQ_LAST_FAST(&rack->r_ctl.rc_tmap, rack_sendmap, r_tnext);
17251 		if (end_rsm)
17252 			kern_prefetch(end_rsm, &prefetch_rsm);
17253 		prefetch_rsm = 1;
17254 	}
17255 	SOCKBUF_LOCK(sb);
17256 	/*
17257 	 * If snd_nxt == snd_max and we have transmitted a FIN, the
17258 	 * sb_offset will be > 0 even if so_snd.sb_cc is 0, resulting in a
17259 	 * negative length.  This can also occur when TCP opens up its
17260 	 * congestion window while receiving additional duplicate acks after
17261 	 * fast-retransmit because TCP will reset snd_nxt to snd_max after
17262 	 * the fast-retransmit.
17263 	 *
17264 	 * In the normal retransmit-FIN-only case, however, snd_nxt will be
17265 	 * set to snd_una, the sb_offset will be 0, and the length may wind
17266 	 * up 0.
17267 	 *
17268 	 * If sack_rxmit is true we are retransmitting from the scoreboard
17269 	 * in which case len is already set.
17270 	 */
17271 	if ((sack_rxmit == 0) &&
17272 	    (TCPS_HAVEESTABLISHED(tp->t_state) || IS_FASTOPEN(tp->t_flags))) {
17273 		uint32_t avail;
17274 
17275 		avail = sbavail(sb);
17276 		if (SEQ_GT(tp->snd_nxt, tp->snd_una) && avail)
17277 			sb_offset = tp->snd_nxt - tp->snd_una;
17278 		else
17279 			sb_offset = 0;
17280 		if ((IN_FASTRECOVERY(tp->t_flags) == 0) || rack->rack_no_prr) {
17281 			if (rack->r_ctl.rc_tlp_new_data) {
17282 				/* TLP is forcing out new data */
17283 				if (rack->r_ctl.rc_tlp_new_data > (uint32_t) (avail - sb_offset)) {
17284 					rack->r_ctl.rc_tlp_new_data = (uint32_t) (avail - sb_offset);
17285 				}
17286 				if ((rack->r_ctl.rc_tlp_new_data + sb_offset) > tp->snd_wnd) {
17287 					if (tp->snd_wnd > sb_offset)
17288 						len = tp->snd_wnd - sb_offset;
17289 					else
17290 						len = 0;
17291 				} else {
17292 					len = rack->r_ctl.rc_tlp_new_data;
17293 				}
17294 				rack->r_ctl.rc_tlp_new_data = 0;
17295 			}  else {
17296 				len = rack_what_can_we_send(tp, rack, cwnd_to_use, avail, sb_offset);
17297 			}
17298 			if ((rack->r_ctl.crte == NULL) && IN_FASTRECOVERY(tp->t_flags) && (len > segsiz)) {
17299 				/*
17300 				 * For prr=off, we need to send only 1 MSS
17301 				 * at a time. We do this because another sack could
17302 				 * be arriving that causes us to send retransmits and
17303 				 * we don't want to be on a long pace due to a larger send
17304 				 * that keeps us from sending out the retransmit.
17305 				 */
17306 				len = segsiz;
17307 			}
17308 		} else {
17309 			uint32_t outstanding;
17310 			/*
17311 			 * We are inside of a Fast recovery episode, this
17312 			 * is caused by a SACK or 3 dup acks. At this point
17313 			 * we have sent all the retransmissions and we rely
17314 			 * on PRR to dictate what we will send in the form of
17315 			 * new data.
17316 			 */
17317 
17318 			outstanding = tp->snd_max - tp->snd_una;
17319 			if ((rack->r_ctl.rc_prr_sndcnt + outstanding) > tp->snd_wnd) {
17320 				if (tp->snd_wnd > outstanding) {
17321 					len = tp->snd_wnd - outstanding;
17322 					/* Check to see if we have the data */
17323 					if ((sb_offset + len) > avail) {
17324 						/* It does not all fit */
17325 						if (avail > sb_offset)
17326 							len = avail - sb_offset;
17327 						else
17328 							len = 0;
17329 					}
17330 				} else {
17331 					len = 0;
17332 				}
17333 			} else if (avail > sb_offset) {
17334 				len = avail - sb_offset;
17335 			} else {
17336 				len = 0;
17337 			}
17338 			if (len > 0) {
17339 				if (len > rack->r_ctl.rc_prr_sndcnt) {
17340 					len = rack->r_ctl.rc_prr_sndcnt;
17341 				}
17342 				if (len > 0) {
17343 					sub_from_prr = 1;
17344 				}
17345 			}
17346 			if (len > segsiz) {
17347 				/*
17348 				 * We should never send more than a MSS when
17349 				 * retransmitting or sending new data in prr
17350 				 * mode unless the override flag is on. Most
17351 				 * likely the PRR algorithm is not going to
17352 				 * let us send a lot as well :-)
17353 				 */
17354 				if (rack->r_ctl.rc_prr_sendalot == 0) {
17355 					len = segsiz;
17356 				}
17357 			} else if (len < segsiz) {
17358 				/*
17359 				 * Do we send any? The idea here is if the
17360 				 * send empty's the socket buffer we want to
17361 				 * do it. However if not then lets just wait
17362 				 * for our prr_sndcnt to get bigger.
17363 				 */
17364 				long leftinsb;
17365 
17366 				leftinsb = sbavail(sb) - sb_offset;
17367 				if (leftinsb > len) {
17368 					/* This send does not empty the sb */
17369 					len = 0;
17370 				}
17371 			}
17372 		}
17373 	} else if (!TCPS_HAVEESTABLISHED(tp->t_state)) {
17374 		/*
17375 		 * If you have not established
17376 		 * and are not doing FAST OPEN
17377 		 * no data please.
17378 		 */
17379 		if ((sack_rxmit == 0) &&
17380 		    (!IS_FASTOPEN(tp->t_flags))){
17381 			len = 0;
17382 			sb_offset = 0;
17383 		}
17384 	}
17385 	if (prefetch_so_done == 0) {
17386 		kern_prefetch(so, &prefetch_so_done);
17387 		prefetch_so_done = 1;
17388 	}
17389 	/*
17390 	 * Lop off SYN bit if it has already been sent.  However, if this is
17391 	 * SYN-SENT state and if segment contains data and if we don't know
17392 	 * that foreign host supports TAO, suppress sending segment.
17393 	 */
17394 	if ((flags & TH_SYN) && SEQ_GT(tp->snd_nxt, tp->snd_una) &&
17395 	    ((sack_rxmit == 0) && (tp->t_rxtshift == 0))) {
17396 		/*
17397 		 * When sending additional segments following a TFO SYN|ACK,
17398 		 * do not include the SYN bit.
17399 		 */
17400 		if (IS_FASTOPEN(tp->t_flags) &&
17401 		    (tp->t_state == TCPS_SYN_RECEIVED))
17402 			flags &= ~TH_SYN;
17403 	}
17404 	/*
17405 	 * Be careful not to send data and/or FIN on SYN segments. This
17406 	 * measure is needed to prevent interoperability problems with not
17407 	 * fully conformant TCP implementations.
17408 	 */
17409 	if ((flags & TH_SYN) && (tp->t_flags & TF_NOOPT)) {
17410 		len = 0;
17411 		flags &= ~TH_FIN;
17412 	}
17413 	/*
17414 	 * On TFO sockets, ensure no data is sent in the following cases:
17415 	 *
17416 	 *  - When retransmitting SYN|ACK on a passively-created socket
17417 	 *
17418 	 *  - When retransmitting SYN on an actively created socket
17419 	 *
17420 	 *  - When sending a zero-length cookie (cookie request) on an
17421 	 *    actively created socket
17422 	 *
17423 	 *  - When the socket is in the CLOSED state (RST is being sent)
17424 	 */
17425 	if (IS_FASTOPEN(tp->t_flags) &&
17426 	    (((flags & TH_SYN) && (tp->t_rxtshift > 0)) ||
17427 	     ((tp->t_state == TCPS_SYN_SENT) &&
17428 	      (tp->t_tfo_client_cookie_len == 0)) ||
17429 	     (flags & TH_RST))) {
17430 		sack_rxmit = 0;
17431 		len = 0;
17432 	}
17433 	/* Without fast-open there should never be data sent on a SYN */
17434 	if ((flags & TH_SYN) && (!IS_FASTOPEN(tp->t_flags))) {
17435 		tp->snd_nxt = tp->iss;
17436 		len = 0;
17437 	}
17438 	if ((len > segsiz) && (tcp_dsack_block_exists(tp))) {
17439 		/* We only send 1 MSS if we have a DSACK block */
17440 		add_flag |= RACK_SENT_W_DSACK;
17441 		len = segsiz;
17442 	}
17443 	orig_len = len;
17444 	if (len <= 0) {
17445 		/*
17446 		 * If FIN has been sent but not acked, but we haven't been
17447 		 * called to retransmit, len will be < 0.  Otherwise, window
17448 		 * shrank after we sent into it.  If window shrank to 0,
17449 		 * cancel pending retransmit, pull snd_nxt back to (closed)
17450 		 * window, and set the persist timer if it isn't already
17451 		 * going.  If the window didn't close completely, just wait
17452 		 * for an ACK.
17453 		 *
17454 		 * We also do a general check here to ensure that we will
17455 		 * set the persist timer when we have data to send, but a
17456 		 * 0-byte window. This makes sure the persist timer is set
17457 		 * even if the packet hits one of the "goto send" lines
17458 		 * below.
17459 		 */
17460 		len = 0;
17461 		if ((tp->snd_wnd == 0) &&
17462 		    (TCPS_HAVEESTABLISHED(tp->t_state)) &&
17463 		    (tp->snd_una == tp->snd_max) &&
17464 		    (sb_offset < (int)sbavail(sb))) {
17465 			rack_enter_persist(tp, rack, cts);
17466 		}
17467 	} else if ((rsm == NULL) &&
17468 		   (doing_tlp == 0) &&
17469 		   (len < pace_max_seg)) {
17470 		/*
17471 		 * We are not sending a maximum sized segment for
17472 		 * some reason. Should we not send anything (think
17473 		 * sws or persists)?
17474 		 */
17475 		if ((tp->snd_wnd < min((rack->r_ctl.rc_high_rwnd/2), minseg)) &&
17476 		    (TCPS_HAVEESTABLISHED(tp->t_state)) &&
17477 		    (len < minseg) &&
17478 		    (len < (int)(sbavail(sb) - sb_offset))) {
17479 			/*
17480 			 * Here the rwnd is less than
17481 			 * the minimum pacing size, this is not a retransmit,
17482 			 * we are established and
17483 			 * the send is not the last in the socket buffer
17484 			 * we send nothing, and we may enter persists
17485 			 * if nothing is outstanding.
17486 			 */
17487 			len = 0;
17488 			if (tp->snd_max == tp->snd_una) {
17489 				/*
17490 				 * Nothing out we can
17491 				 * go into persists.
17492 				 */
17493 				rack_enter_persist(tp, rack, cts);
17494 			}
17495 		     } else if ((cwnd_to_use >= max(minseg, (segsiz * 4))) &&
17496 			   (ctf_flight_size(tp, rack->r_ctl.rc_sacked) > (2 * segsiz)) &&
17497 			   (len < (int)(sbavail(sb) - sb_offset)) &&
17498 			   (len < minseg)) {
17499 			/*
17500 			 * Here we are not retransmitting, and
17501 			 * the cwnd is not so small that we could
17502 			 * not send at least a min size (rxt timer
17503 			 * not having gone off), We have 2 segments or
17504 			 * more already in flight, its not the tail end
17505 			 * of the socket buffer  and the cwnd is blocking
17506 			 * us from sending out a minimum pacing segment size.
17507 			 * Lets not send anything.
17508 			 */
17509 			len = 0;
17510 		} else if (((tp->snd_wnd - ctf_outstanding(tp)) <
17511 			    min((rack->r_ctl.rc_high_rwnd/2), minseg)) &&
17512 			   (ctf_flight_size(tp, rack->r_ctl.rc_sacked) > (2 * segsiz)) &&
17513 			   (len < (int)(sbavail(sb) - sb_offset)) &&
17514 			   (TCPS_HAVEESTABLISHED(tp->t_state))) {
17515 			/*
17516 			 * Here we have a send window but we have
17517 			 * filled it up and we can't send another pacing segment.
17518 			 * We also have in flight more than 2 segments
17519 			 * and we are not completing the sb i.e. we allow
17520 			 * the last bytes of the sb to go out even if
17521 			 * its not a full pacing segment.
17522 			 */
17523 			len = 0;
17524 		} else if ((rack->r_ctl.crte != NULL) &&
17525 			   (tp->snd_wnd >= (pace_max_seg * max(1, rack_hw_rwnd_factor))) &&
17526 			   (cwnd_to_use >= (pace_max_seg + (4 * segsiz))) &&
17527 			   (ctf_flight_size(tp, rack->r_ctl.rc_sacked) >= (2 * segsiz)) &&
17528 			   (len < (int)(sbavail(sb) - sb_offset))) {
17529 			/*
17530 			 * Here we are doing hardware pacing, this is not a TLP,
17531 			 * we are not sending a pace max segment size, there is rwnd
17532 			 * room to send at least N pace_max_seg, the cwnd is greater
17533 			 * than or equal to a full pacing segments plus 4 mss and we have 2 or
17534 			 * more segments in flight and its not the tail of the socket buffer.
17535 			 *
17536 			 * We don't want to send instead we need to get more ack's in to
17537 			 * allow us to send a full pacing segment. Normally, if we are pacing
17538 			 * about the right speed, we should have finished our pacing
17539 			 * send as most of the acks have come back if we are at the
17540 			 * right rate. This is a bit fuzzy since return path delay
17541 			 * can delay the acks, which is why we want to make sure we
17542 			 * have cwnd space to have a bit more than a max pace segments in flight.
17543 			 *
17544 			 * If we have not gotten our acks back we are pacing at too high a
17545 			 * rate delaying will not hurt and will bring our GP estimate down by
17546 			 * injecting the delay. If we don't do this we will send
17547 			 * 2 MSS out in response to the acks being clocked in which
17548 			 * defeats the point of hw-pacing (i.e. to help us get
17549 			 * larger TSO's out).
17550 			 */
17551 			len = 0;
17552 
17553 		}
17554 
17555 	}
17556 	/* len will be >= 0 after this point. */
17557 	KASSERT(len >= 0, ("[%s:%d]: len < 0", __func__, __LINE__));
17558 	rack_sndbuf_autoscale(rack);
17559 	/*
17560 	 * Decide if we can use TCP Segmentation Offloading (if supported by
17561 	 * hardware).
17562 	 *
17563 	 * TSO may only be used if we are in a pure bulk sending state.  The
17564 	 * presence of TCP-MD5, SACK retransmits, SACK advertizements and IP
17565 	 * options prevent using TSO.  With TSO the TCP header is the same
17566 	 * (except for the sequence number) for all generated packets.  This
17567 	 * makes it impossible to transmit any options which vary per
17568 	 * generated segment or packet.
17569 	 *
17570 	 * IPv4 handling has a clear separation of ip options and ip header
17571 	 * flags while IPv6 combines both in in6p_outputopts. ip6_optlen() does
17572 	 * the right thing below to provide length of just ip options and thus
17573 	 * checking for ipoptlen is enough to decide if ip options are present.
17574 	 */
17575 	ipoptlen = 0;
17576 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
17577 	/*
17578 	 * Pre-calculate here as we save another lookup into the darknesses
17579 	 * of IPsec that way and can actually decide if TSO is ok.
17580 	 */
17581 #ifdef INET6
17582 	if (isipv6 && IPSEC_ENABLED(ipv6))
17583 		ipsec_optlen = IPSEC_HDRSIZE(ipv6, tp->t_inpcb);
17584 #ifdef INET
17585 	else
17586 #endif
17587 #endif				/* INET6 */
17588 #ifdef INET
17589 		if (IPSEC_ENABLED(ipv4))
17590 			ipsec_optlen = IPSEC_HDRSIZE(ipv4, tp->t_inpcb);
17591 #endif				/* INET */
17592 #endif
17593 
17594 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
17595 	ipoptlen += ipsec_optlen;
17596 #endif
17597 	if ((tp->t_flags & TF_TSO) && V_tcp_do_tso && len > segsiz &&
17598 	    (tp->t_port == 0) &&
17599 	    ((tp->t_flags & TF_SIGNATURE) == 0) &&
17600 	    tp->rcv_numsacks == 0 && sack_rxmit == 0 &&
17601 	    ipoptlen == 0)
17602 		tso = 1;
17603 	{
17604 		uint32_t outstanding __unused;
17605 
17606 		outstanding = tp->snd_max - tp->snd_una;
17607 		if (tp->t_flags & TF_SENTFIN) {
17608 			/*
17609 			 * If we sent a fin, snd_max is 1 higher than
17610 			 * snd_una
17611 			 */
17612 			outstanding--;
17613 		}
17614 		if (sack_rxmit) {
17615 			if ((rsm->r_flags & RACK_HAS_FIN) == 0)
17616 				flags &= ~TH_FIN;
17617 		} else {
17618 			if (SEQ_LT(tp->snd_nxt + len, tp->snd_una +
17619 				   sbused(sb)))
17620 				flags &= ~TH_FIN;
17621 		}
17622 	}
17623 	recwin = lmin(lmax(sbspace(&so->so_rcv), 0),
17624 	    (long)TCP_MAXWIN << tp->rcv_scale);
17625 
17626 	/*
17627 	 * Sender silly window avoidance.   We transmit under the following
17628 	 * conditions when len is non-zero:
17629 	 *
17630 	 * - We have a full segment (or more with TSO) - This is the last
17631 	 * buffer in a write()/send() and we are either idle or running
17632 	 * NODELAY - we've timed out (e.g. persist timer) - we have more
17633 	 * then 1/2 the maximum send window's worth of data (receiver may be
17634 	 * limited the window size) - we need to retransmit
17635 	 */
17636 	if (len) {
17637 		if (len >= segsiz) {
17638 			goto send;
17639 		}
17640 		/*
17641 		 * NOTE! on localhost connections an 'ack' from the remote
17642 		 * end may occur synchronously with the output and cause us
17643 		 * to flush a buffer queued with moretocome.  XXX
17644 		 *
17645 		 */
17646 		if (!(tp->t_flags & TF_MORETOCOME) &&	/* normal case */
17647 		    (idle || (tp->t_flags & TF_NODELAY)) &&
17648 		    ((uint32_t)len + (uint32_t)sb_offset >= sbavail(sb)) &&
17649 		    (tp->t_flags & TF_NOPUSH) == 0) {
17650 			pass = 2;
17651 			goto send;
17652 		}
17653 		if ((tp->snd_una == tp->snd_max) && len) {	/* Nothing outstanding */
17654 			pass = 22;
17655 			goto send;
17656 		}
17657 		if (len >= tp->max_sndwnd / 2 && tp->max_sndwnd > 0) {
17658 			pass = 4;
17659 			goto send;
17660 		}
17661 		if (SEQ_LT(tp->snd_nxt, tp->snd_max)) {	/* retransmit case */
17662 			pass = 5;
17663 			goto send;
17664 		}
17665 		if (sack_rxmit) {
17666 			pass = 6;
17667 			goto send;
17668 		}
17669 		if (((tp->snd_wnd - ctf_outstanding(tp)) < segsiz) &&
17670 		    (ctf_outstanding(tp) < (segsiz * 2))) {
17671 			/*
17672 			 * We have less than two MSS outstanding (delayed ack)
17673 			 * and our rwnd will not let us send a full sized
17674 			 * MSS. Lets go ahead and let this small segment
17675 			 * out because we want to try to have at least two
17676 			 * packets inflight to not be caught by delayed ack.
17677 			 */
17678 			pass = 12;
17679 			goto send;
17680 		}
17681 	}
17682 	/*
17683 	 * Sending of standalone window updates.
17684 	 *
17685 	 * Window updates are important when we close our window due to a
17686 	 * full socket buffer and are opening it again after the application
17687 	 * reads data from it.  Once the window has opened again and the
17688 	 * remote end starts to send again the ACK clock takes over and
17689 	 * provides the most current window information.
17690 	 *
17691 	 * We must avoid the silly window syndrome whereas every read from
17692 	 * the receive buffer, no matter how small, causes a window update
17693 	 * to be sent.  We also should avoid sending a flurry of window
17694 	 * updates when the socket buffer had queued a lot of data and the
17695 	 * application is doing small reads.
17696 	 *
17697 	 * Prevent a flurry of pointless window updates by only sending an
17698 	 * update when we can increase the advertized window by more than
17699 	 * 1/4th of the socket buffer capacity.  When the buffer is getting
17700 	 * full or is very small be more aggressive and send an update
17701 	 * whenever we can increase by two mss sized segments. In all other
17702 	 * situations the ACK's to new incoming data will carry further
17703 	 * window increases.
17704 	 *
17705 	 * Don't send an independent window update if a delayed ACK is
17706 	 * pending (it will get piggy-backed on it) or the remote side
17707 	 * already has done a half-close and won't send more data.  Skip
17708 	 * this if the connection is in T/TCP half-open state.
17709 	 */
17710 	if (recwin > 0 && !(tp->t_flags & TF_NEEDSYN) &&
17711 	    !(tp->t_flags & TF_DELACK) &&
17712 	    !TCPS_HAVERCVDFIN(tp->t_state)) {
17713 		/*
17714 		 * "adv" is the amount we could increase the window, taking
17715 		 * into account that we are limited by TCP_MAXWIN <<
17716 		 * tp->rcv_scale.
17717 		 */
17718 		int32_t adv;
17719 		int oldwin;
17720 
17721 		adv = recwin;
17722 		if (SEQ_GT(tp->rcv_adv, tp->rcv_nxt)) {
17723 			oldwin = (tp->rcv_adv - tp->rcv_nxt);
17724 			if (adv > oldwin)
17725 			    adv -= oldwin;
17726 			else {
17727 				/* We can't increase the window */
17728 				adv = 0;
17729 			}
17730 		} else
17731 			oldwin = 0;
17732 
17733 		/*
17734 		 * If the new window size ends up being the same as or less
17735 		 * than the old size when it is scaled, then don't force
17736 		 * a window update.
17737 		 */
17738 		if (oldwin >> tp->rcv_scale >= (adv + oldwin) >> tp->rcv_scale)
17739 			goto dontupdate;
17740 
17741 		if (adv >= (int32_t)(2 * segsiz) &&
17742 		    (adv >= (int32_t)(so->so_rcv.sb_hiwat / 4) ||
17743 		     recwin <= (int32_t)(so->so_rcv.sb_hiwat / 8) ||
17744 		     so->so_rcv.sb_hiwat <= 8 * segsiz)) {
17745 			pass = 7;
17746 			goto send;
17747 		}
17748 		if (2 * adv >= (int32_t) so->so_rcv.sb_hiwat) {
17749 			pass = 23;
17750 			goto send;
17751 		}
17752 	}
17753 dontupdate:
17754 
17755 	/*
17756 	 * Send if we owe the peer an ACK, RST, SYN, or urgent data.  ACKNOW
17757 	 * is also a catch-all for the retransmit timer timeout case.
17758 	 */
17759 	if (tp->t_flags & TF_ACKNOW) {
17760 		pass = 8;
17761 		goto send;
17762 	}
17763 	if (((flags & TH_SYN) && (tp->t_flags & TF_NEEDSYN) == 0)) {
17764 		pass = 9;
17765 		goto send;
17766 	}
17767 	/*
17768 	 * If our state indicates that FIN should be sent and we have not
17769 	 * yet done so, then we need to send.
17770 	 */
17771 	if ((flags & TH_FIN) &&
17772 	    (tp->snd_nxt == tp->snd_una)) {
17773 		pass = 11;
17774 		goto send;
17775 	}
17776 	/*
17777 	 * No reason to send a segment, just return.
17778 	 */
17779 just_return:
17780 	SOCKBUF_UNLOCK(sb);
17781 just_return_nolock:
17782 	{
17783 		int app_limited = CTF_JR_SENT_DATA;
17784 
17785 		if (tot_len_this_send > 0) {
17786 			/* Make sure snd_nxt is up to max */
17787 			rack->r_ctl.fsb.recwin = recwin;
17788 			slot = rack_get_pacing_delay(rack, tp, tot_len_this_send, NULL, segsiz);
17789 			if ((error == 0) &&
17790 			    rack_use_rfo &&
17791 			    ((flags & (TH_SYN|TH_FIN)) == 0) &&
17792 			    (ipoptlen == 0) &&
17793 			    (tp->snd_nxt == tp->snd_max) &&
17794 			    (tp->rcv_numsacks == 0) &&
17795 			    rack->r_fsb_inited &&
17796 			    TCPS_HAVEESTABLISHED(tp->t_state) &&
17797 			    (rack->r_must_retran == 0) &&
17798 			    ((tp->t_flags & TF_NEEDFIN) == 0) &&
17799 			    (len > 0) && (orig_len > 0) &&
17800 			    (orig_len > len) &&
17801 			    ((orig_len - len) >= segsiz) &&
17802 			    ((optlen == 0) ||
17803 			     ((optlen == TCPOLEN_TSTAMP_APPA) && (to.to_flags & TOF_TS)))) {
17804 				/* We can send at least one more MSS using our fsb */
17805 
17806 				rack->r_fast_output = 1;
17807 				rack->r_ctl.fsb.m = sbsndmbuf(sb, (tp->snd_max - tp->snd_una), &rack->r_ctl.fsb.off);
17808 				rack->r_ctl.fsb.o_m_len = rack->r_ctl.fsb.m->m_len;
17809 				rack->r_ctl.fsb.tcp_flags = flags;
17810 				rack->r_ctl.fsb.left_to_send = orig_len - len;
17811 				if (hw_tls)
17812 					rack->r_ctl.fsb.hw_tls = 1;
17813 				else
17814 					rack->r_ctl.fsb.hw_tls = 0;
17815 				KASSERT((rack->r_ctl.fsb.left_to_send <= (sbavail(sb) - (tp->snd_max - tp->snd_una))),
17816 					("rack:%p left_to_send:%u sbavail:%u out:%u",
17817 					rack, rack->r_ctl.fsb.left_to_send, sbavail(sb),
17818 					 (tp->snd_max - tp->snd_una)));
17819 				if (rack->r_ctl.fsb.left_to_send < segsiz)
17820 					rack->r_fast_output = 0;
17821 				else {
17822 					if (rack->r_ctl.fsb.left_to_send == (sbavail(sb) - (tp->snd_max - tp->snd_una)))
17823 						rack->r_ctl.fsb.rfo_apply_push = 1;
17824 					else
17825 						rack->r_ctl.fsb.rfo_apply_push = 0;
17826 				}
17827 			} else
17828 				rack->r_fast_output = 0;
17829 
17830 
17831 			rack_log_fsb(rack, tp, so, flags,
17832 				     ipoptlen, orig_len, len, 0,
17833 				     1, optlen, __LINE__, 1);
17834 			if (SEQ_GT(tp->snd_max, tp->snd_nxt))
17835 				tp->snd_nxt = tp->snd_max;
17836 		} else {
17837 			int end_window = 0;
17838 			uint32_t seq = tp->gput_ack;
17839 
17840 			rsm = RB_MAX(rack_rb_tree_head, &rack->r_ctl.rc_mtree);
17841 			if (rsm) {
17842 				/*
17843 				 * Mark the last sent that we just-returned (hinting
17844 				 * that delayed ack may play a role in any rtt measurement).
17845 				 */
17846 				rsm->r_just_ret = 1;
17847 			}
17848 			counter_u64_add(rack_out_size[TCP_MSS_ACCT_JUSTRET], 1);
17849 			rack->r_ctl.rc_agg_delayed = 0;
17850 			rack->r_early = 0;
17851 			rack->r_late = 0;
17852 			rack->r_ctl.rc_agg_early = 0;
17853 			if ((ctf_outstanding(tp) +
17854 			     min(max(segsiz, (rack->r_ctl.rc_high_rwnd/2)),
17855 				 minseg)) >= tp->snd_wnd) {
17856 				/* We are limited by the rwnd */
17857 				app_limited = CTF_JR_RWND_LIMITED;
17858 				if (IN_FASTRECOVERY(tp->t_flags))
17859 				    rack->r_ctl.rc_prr_sndcnt = 0;
17860 			} else if (ctf_outstanding(tp) >= sbavail(sb)) {
17861 				/* We are limited by whats available -- app limited */
17862 				app_limited = CTF_JR_APP_LIMITED;
17863 				if (IN_FASTRECOVERY(tp->t_flags))
17864 				    rack->r_ctl.rc_prr_sndcnt = 0;
17865 			} else if ((idle == 0) &&
17866 				   ((tp->t_flags & TF_NODELAY) == 0) &&
17867 				   ((uint32_t)len + (uint32_t)sb_offset >= sbavail(sb)) &&
17868 				   (len < segsiz)) {
17869 				/*
17870 				 * No delay is not on and the
17871 				 * user is sending less than 1MSS. This
17872 				 * brings out SWS avoidance so we
17873 				 * don't send. Another app-limited case.
17874 				 */
17875 				app_limited = CTF_JR_APP_LIMITED;
17876 			} else if (tp->t_flags & TF_NOPUSH) {
17877 				/*
17878 				 * The user has requested no push of
17879 				 * the last segment and we are
17880 				 * at the last segment. Another app
17881 				 * limited case.
17882 				 */
17883 				app_limited = CTF_JR_APP_LIMITED;
17884 			} else if ((ctf_outstanding(tp) + minseg) > cwnd_to_use) {
17885 				/* Its the cwnd */
17886 				app_limited = CTF_JR_CWND_LIMITED;
17887 			} else if (IN_FASTRECOVERY(tp->t_flags) &&
17888 				   (rack->rack_no_prr == 0) &&
17889 				   (rack->r_ctl.rc_prr_sndcnt < segsiz)) {
17890 				app_limited = CTF_JR_PRR;
17891 			} else {
17892 				/* Now why here are we not sending? */
17893 #ifdef NOW
17894 #ifdef INVARIANTS
17895 				panic("rack:%p hit JR_ASSESSING case cwnd_to_use:%u?", rack, cwnd_to_use);
17896 #endif
17897 #endif
17898 				app_limited = CTF_JR_ASSESSING;
17899 			}
17900 			/*
17901 			 * App limited in some fashion, for our pacing GP
17902 			 * measurements we don't want any gap (even cwnd).
17903 			 * Close  down the measurement window.
17904 			 */
17905 			if (rack_cwnd_block_ends_measure &&
17906 			    ((app_limited == CTF_JR_CWND_LIMITED) ||
17907 			     (app_limited == CTF_JR_PRR))) {
17908 				/*
17909 				 * The reason we are not sending is
17910 				 * the cwnd (or prr). We have been configured
17911 				 * to end the measurement window in
17912 				 * this case.
17913 				 */
17914 				end_window = 1;
17915 			} else if (rack_rwnd_block_ends_measure &&
17916 				   (app_limited == CTF_JR_RWND_LIMITED)) {
17917 				/*
17918 				 * We are rwnd limited and have been
17919 				 * configured to end the measurement
17920 				 * window in this case.
17921 				 */
17922 				end_window = 1;
17923 			} else if (app_limited == CTF_JR_APP_LIMITED) {
17924 				/*
17925 				 * A true application limited period, we have
17926 				 * ran out of data.
17927 				 */
17928 				end_window = 1;
17929 			} else if (app_limited == CTF_JR_ASSESSING) {
17930 				/*
17931 				 * In the assessing case we hit the end of
17932 				 * the if/else and had no known reason
17933 				 * This will panic us under invariants..
17934 				 *
17935 				 * If we get this out in logs we need to
17936 				 * investagate which reason we missed.
17937 				 */
17938 				end_window = 1;
17939 			}
17940 			if (end_window) {
17941 				uint8_t log = 0;
17942 
17943 				/* Adjust the Gput measurement */
17944 				if ((tp->t_flags & TF_GPUTINPROG) &&
17945 				    SEQ_GT(tp->gput_ack, tp->snd_max)) {
17946 					tp->gput_ack = tp->snd_max;
17947 					if ((tp->gput_ack - tp->gput_seq) < (MIN_GP_WIN * segsiz)) {
17948 						/*
17949 						 * There is not enough to measure.
17950 						 */
17951 						tp->t_flags &= ~TF_GPUTINPROG;
17952 						rack_log_pacing_delay_calc(rack, (tp->gput_ack - tp->gput_seq) /*flex2*/,
17953 									   rack->r_ctl.rc_gp_srtt /*flex1*/,
17954 									   tp->gput_seq,
17955 									   0, 0, 18, __LINE__, NULL, 0);
17956 					} else
17957 						log = 1;
17958 				}
17959 				/* Mark the last packet has app limited */
17960 				rsm = RB_MAX(rack_rb_tree_head, &rack->r_ctl.rc_mtree);
17961 				if (rsm && ((rsm->r_flags & RACK_APP_LIMITED) == 0)) {
17962 					if (rack->r_ctl.rc_app_limited_cnt == 0)
17963 						rack->r_ctl.rc_end_appl = rack->r_ctl.rc_first_appl = rsm;
17964 					else {
17965 						/*
17966 						 * Go out to the end app limited and mark
17967 						 * this new one as next and move the end_appl up
17968 						 * to this guy.
17969 						 */
17970 						if (rack->r_ctl.rc_end_appl)
17971 							rack->r_ctl.rc_end_appl->r_nseq_appl = rsm->r_start;
17972 						rack->r_ctl.rc_end_appl = rsm;
17973 					}
17974 					rsm->r_flags |= RACK_APP_LIMITED;
17975 					rack->r_ctl.rc_app_limited_cnt++;
17976 				}
17977 				if (log)
17978 					rack_log_pacing_delay_calc(rack,
17979 								   rack->r_ctl.rc_app_limited_cnt, seq,
17980 								   tp->gput_ack, 0, 0, 4, __LINE__, NULL, 0);
17981 			}
17982 		}
17983 		/* Check if we need to go into persists or not */
17984 		if ((tp->snd_max == tp->snd_una) &&
17985 		    TCPS_HAVEESTABLISHED(tp->t_state) &&
17986 		    sbavail(sb) &&
17987 		    (sbavail(sb) > tp->snd_wnd) &&
17988 		    (tp->snd_wnd < min((rack->r_ctl.rc_high_rwnd/2), minseg))) {
17989 			/* Yes lets make sure to move to persist before timer-start */
17990 			rack_enter_persist(tp, rack, rack->r_ctl.rc_rcvtime);
17991 		}
17992 		rack_start_hpts_timer(rack, tp, cts, slot, tot_len_this_send, sup_rack);
17993 		rack_log_type_just_return(rack, cts, tot_len_this_send, slot, hpts_calling, app_limited, cwnd_to_use);
17994 	}
17995 #ifdef NETFLIX_SHARED_CWND
17996 	if ((sbavail(sb) == 0) &&
17997 	    rack->r_ctl.rc_scw) {
17998 		tcp_shared_cwnd_idle(rack->r_ctl.rc_scw, rack->r_ctl.rc_scw_index);
17999 		rack->rack_scwnd_is_idle = 1;
18000 	}
18001 #endif
18002 #ifdef TCP_ACCOUNTING
18003 	if (tot_len_this_send > 0) {
18004 		crtsc = get_cyclecount();
18005 		if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
18006 			tp->tcp_cnt_counters[SND_OUT_DATA]++;
18007 		}
18008 		counter_u64_add(tcp_cnt_counters[SND_OUT_DATA], 1);
18009 		if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
18010 			tp->tcp_proc_time[SND_OUT_DATA] += (crtsc - ts_val);
18011 		}
18012 		counter_u64_add(tcp_proc_time[SND_OUT_DATA], (crtsc - ts_val));
18013 		if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
18014 			tp->tcp_cnt_counters[CNT_OF_MSS_OUT] += ((tot_len_this_send + segsiz - 1) / segsiz);
18015 		}
18016 		counter_u64_add(tcp_cnt_counters[CNT_OF_MSS_OUT], ((tot_len_this_send + segsiz - 1) / segsiz));
18017 	} else {
18018 		crtsc = get_cyclecount();
18019 		if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
18020 			tp->tcp_cnt_counters[SND_LIMITED]++;
18021 		}
18022 		counter_u64_add(tcp_cnt_counters[SND_LIMITED], 1);
18023 		if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
18024 			tp->tcp_proc_time[SND_LIMITED] += (crtsc - ts_val);
18025 		}
18026 		counter_u64_add(tcp_proc_time[SND_LIMITED], (crtsc - ts_val));
18027 	}
18028 	sched_unpin();
18029 #endif
18030 	return (0);
18031 
18032 send:
18033 	if (rsm || sack_rxmit)
18034 		counter_u64_add(rack_nfto_resend, 1);
18035 	else
18036 		counter_u64_add(rack_non_fto_send, 1);
18037 	if ((flags & TH_FIN) &&
18038 	    sbavail(sb)) {
18039 		/*
18040 		 * We do not transmit a FIN
18041 		 * with data outstanding. We
18042 		 * need to make it so all data
18043 		 * is acked first.
18044 		 */
18045 		flags &= ~TH_FIN;
18046 	}
18047 	/* Enforce stack imposed max seg size if we have one */
18048 	if (rack->r_ctl.rc_pace_max_segs &&
18049 	    (len > rack->r_ctl.rc_pace_max_segs)) {
18050 		mark = 1;
18051 		len = rack->r_ctl.rc_pace_max_segs;
18052 	}
18053 	SOCKBUF_LOCK_ASSERT(sb);
18054 	if (len > 0) {
18055 		if (len >= segsiz)
18056 			tp->t_flags2 |= TF2_PLPMTU_MAXSEGSNT;
18057 		else
18058 			tp->t_flags2 &= ~TF2_PLPMTU_MAXSEGSNT;
18059 	}
18060 	/*
18061 	 * Before ESTABLISHED, force sending of initial options unless TCP
18062 	 * set not to do any options. NOTE: we assume that the IP/TCP header
18063 	 * plus TCP options always fit in a single mbuf, leaving room for a
18064 	 * maximum link header, i.e. max_linkhdr + sizeof (struct tcpiphdr)
18065 	 * + optlen <= MCLBYTES
18066 	 */
18067 	optlen = 0;
18068 #ifdef INET6
18069 	if (isipv6)
18070 		hdrlen = sizeof(struct ip6_hdr) + sizeof(struct tcphdr);
18071 	else
18072 #endif
18073 		hdrlen = sizeof(struct tcpiphdr);
18074 
18075 	/*
18076 	 * Compute options for segment. We only have to care about SYN and
18077 	 * established connection segments.  Options for SYN-ACK segments
18078 	 * are handled in TCP syncache.
18079 	 */
18080 	to.to_flags = 0;
18081 	if ((tp->t_flags & TF_NOOPT) == 0) {
18082 		/* Maximum segment size. */
18083 		if (flags & TH_SYN) {
18084 			tp->snd_nxt = tp->iss;
18085 			to.to_mss = tcp_mssopt(&inp->inp_inc);
18086 			if (tp->t_port)
18087 				to.to_mss -= V_tcp_udp_tunneling_overhead;
18088 			to.to_flags |= TOF_MSS;
18089 
18090 			/*
18091 			 * On SYN or SYN|ACK transmits on TFO connections,
18092 			 * only include the TFO option if it is not a
18093 			 * retransmit, as the presence of the TFO option may
18094 			 * have caused the original SYN or SYN|ACK to have
18095 			 * been dropped by a middlebox.
18096 			 */
18097 			if (IS_FASTOPEN(tp->t_flags) &&
18098 			    (tp->t_rxtshift == 0)) {
18099 				if (tp->t_state == TCPS_SYN_RECEIVED) {
18100 					to.to_tfo_len = TCP_FASTOPEN_COOKIE_LEN;
18101 					to.to_tfo_cookie =
18102 						(u_int8_t *)&tp->t_tfo_cookie.server;
18103 					to.to_flags |= TOF_FASTOPEN;
18104 					wanted_cookie = 1;
18105 				} else if (tp->t_state == TCPS_SYN_SENT) {
18106 					to.to_tfo_len =
18107 						tp->t_tfo_client_cookie_len;
18108 					to.to_tfo_cookie =
18109 						tp->t_tfo_cookie.client;
18110 					to.to_flags |= TOF_FASTOPEN;
18111 					wanted_cookie = 1;
18112 					/*
18113 					 * If we wind up having more data to
18114 					 * send with the SYN than can fit in
18115 					 * one segment, don't send any more
18116 					 * until the SYN|ACK comes back from
18117 					 * the other end.
18118 					 */
18119 					sendalot = 0;
18120 				}
18121 			}
18122 		}
18123 		/* Window scaling. */
18124 		if ((flags & TH_SYN) && (tp->t_flags & TF_REQ_SCALE)) {
18125 			to.to_wscale = tp->request_r_scale;
18126 			to.to_flags |= TOF_SCALE;
18127 		}
18128 		/* Timestamps. */
18129 		if ((tp->t_flags & TF_RCVD_TSTMP) ||
18130 		    ((flags & TH_SYN) && (tp->t_flags & TF_REQ_TSTMP))) {
18131 			to.to_tsval = ms_cts + tp->ts_offset;
18132 			to.to_tsecr = tp->ts_recent;
18133 			to.to_flags |= TOF_TS;
18134 		}
18135 		/* Set receive buffer autosizing timestamp. */
18136 		if (tp->rfbuf_ts == 0 &&
18137 		    (so->so_rcv.sb_flags & SB_AUTOSIZE))
18138 			tp->rfbuf_ts = tcp_ts_getticks();
18139 		/* Selective ACK's. */
18140 		if (tp->t_flags & TF_SACK_PERMIT) {
18141 			if (flags & TH_SYN)
18142 				to.to_flags |= TOF_SACKPERM;
18143 			else if (TCPS_HAVEESTABLISHED(tp->t_state) &&
18144 				 tp->rcv_numsacks > 0) {
18145 				to.to_flags |= TOF_SACK;
18146 				to.to_nsacks = tp->rcv_numsacks;
18147 				to.to_sacks = (u_char *)tp->sackblks;
18148 			}
18149 		}
18150 #if defined(IPSEC_SUPPORT) || defined(TCP_SIGNATURE)
18151 		/* TCP-MD5 (RFC2385). */
18152 		if (tp->t_flags & TF_SIGNATURE)
18153 			to.to_flags |= TOF_SIGNATURE;
18154 #endif				/* TCP_SIGNATURE */
18155 
18156 		/* Processing the options. */
18157 		hdrlen += optlen = tcp_addoptions(&to, opt);
18158 		/*
18159 		 * If we wanted a TFO option to be added, but it was unable
18160 		 * to fit, ensure no data is sent.
18161 		 */
18162 		if (IS_FASTOPEN(tp->t_flags) && wanted_cookie &&
18163 		    !(to.to_flags & TOF_FASTOPEN))
18164 			len = 0;
18165 	}
18166 	if (tp->t_port) {
18167 		if (V_tcp_udp_tunneling_port == 0) {
18168 			/* The port was removed?? */
18169 			SOCKBUF_UNLOCK(&so->so_snd);
18170 #ifdef TCP_ACCOUNTING
18171 			crtsc = get_cyclecount();
18172 			if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
18173 				tp->tcp_cnt_counters[SND_OUT_FAIL]++;
18174 			}
18175 			counter_u64_add(tcp_cnt_counters[SND_OUT_FAIL], 1);
18176 			if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
18177 				tp->tcp_proc_time[SND_OUT_FAIL] += (crtsc - ts_val);
18178 			}
18179 			counter_u64_add(tcp_proc_time[SND_OUT_FAIL], (crtsc - ts_val));
18180 			sched_unpin();
18181 #endif
18182 			return (EHOSTUNREACH);
18183 		}
18184 		hdrlen += sizeof(struct udphdr);
18185 	}
18186 #ifdef INET6
18187 	if (isipv6)
18188 		ipoptlen = ip6_optlen(tp->t_inpcb);
18189 	else
18190 #endif
18191 		if (tp->t_inpcb->inp_options)
18192 			ipoptlen = tp->t_inpcb->inp_options->m_len -
18193 				offsetof(struct ipoption, ipopt_list);
18194 		else
18195 			ipoptlen = 0;
18196 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
18197 	ipoptlen += ipsec_optlen;
18198 #endif
18199 
18200 	/*
18201 	 * Adjust data length if insertion of options will bump the packet
18202 	 * length beyond the t_maxseg length. Clear the FIN bit because we
18203 	 * cut off the tail of the segment.
18204 	 */
18205 	if (len + optlen + ipoptlen > tp->t_maxseg) {
18206 		if (tso) {
18207 			uint32_t if_hw_tsomax;
18208 			uint32_t moff;
18209 			int32_t max_len;
18210 
18211 			/* extract TSO information */
18212 			if_hw_tsomax = tp->t_tsomax;
18213 			if_hw_tsomaxsegcount = tp->t_tsomaxsegcount;
18214 			if_hw_tsomaxsegsize = tp->t_tsomaxsegsize;
18215 			KASSERT(ipoptlen == 0,
18216 				("%s: TSO can't do IP options", __func__));
18217 
18218 			/*
18219 			 * Check if we should limit by maximum payload
18220 			 * length:
18221 			 */
18222 			if (if_hw_tsomax != 0) {
18223 				/* compute maximum TSO length */
18224 				max_len = (if_hw_tsomax - hdrlen -
18225 					   max_linkhdr);
18226 				if (max_len <= 0) {
18227 					len = 0;
18228 				} else if (len > max_len) {
18229 					sendalot = 1;
18230 					len = max_len;
18231 					mark = 2;
18232 				}
18233 			}
18234 			/*
18235 			 * Prevent the last segment from being fractional
18236 			 * unless the send sockbuf can be emptied:
18237 			 */
18238 			max_len = (tp->t_maxseg - optlen);
18239 			if ((sb_offset + len) < sbavail(sb)) {
18240 				moff = len % (u_int)max_len;
18241 				if (moff != 0) {
18242 					mark = 3;
18243 					len -= moff;
18244 				}
18245 			}
18246 			/*
18247 			 * In case there are too many small fragments don't
18248 			 * use TSO:
18249 			 */
18250 			if (len <= segsiz) {
18251 				mark = 4;
18252 				tso = 0;
18253 			}
18254 			/*
18255 			 * Send the FIN in a separate segment after the bulk
18256 			 * sending is done. We don't trust the TSO
18257 			 * implementations to clear the FIN flag on all but
18258 			 * the last segment.
18259 			 */
18260 			if (tp->t_flags & TF_NEEDFIN) {
18261 				sendalot = 4;
18262 			}
18263 		} else {
18264 			mark = 5;
18265 			if (optlen + ipoptlen >= tp->t_maxseg) {
18266 				/*
18267 				 * Since we don't have enough space to put
18268 				 * the IP header chain and the TCP header in
18269 				 * one packet as required by RFC 7112, don't
18270 				 * send it. Also ensure that at least one
18271 				 * byte of the payload can be put into the
18272 				 * TCP segment.
18273 				 */
18274 				SOCKBUF_UNLOCK(&so->so_snd);
18275 				error = EMSGSIZE;
18276 				sack_rxmit = 0;
18277 				goto out;
18278 			}
18279 			len = tp->t_maxseg - optlen - ipoptlen;
18280 			sendalot = 5;
18281 		}
18282 	} else {
18283 		tso = 0;
18284 		mark = 6;
18285 	}
18286 	KASSERT(len + hdrlen + ipoptlen <= IP_MAXPACKET,
18287 		("%s: len > IP_MAXPACKET", __func__));
18288 #ifdef DIAGNOSTIC
18289 #ifdef INET6
18290 	if (max_linkhdr + hdrlen > MCLBYTES)
18291 #else
18292 		if (max_linkhdr + hdrlen > MHLEN)
18293 #endif
18294 			panic("tcphdr too big");
18295 #endif
18296 
18297 	/*
18298 	 * This KASSERT is here to catch edge cases at a well defined place.
18299 	 * Before, those had triggered (random) panic conditions further
18300 	 * down.
18301 	 */
18302 	KASSERT(len >= 0, ("[%s:%d]: len < 0", __func__, __LINE__));
18303 	if ((len == 0) &&
18304 	    (flags & TH_FIN) &&
18305 	    (sbused(sb))) {
18306 		/*
18307 		 * We have outstanding data, don't send a fin by itself!.
18308 		 */
18309 		goto just_return;
18310 	}
18311 	/*
18312 	 * Grab a header mbuf, attaching a copy of data to be transmitted,
18313 	 * and initialize the header from the template for sends on this
18314 	 * connection.
18315 	 */
18316 	hw_tls = (sb->sb_flags & SB_TLS_IFNET) != 0;
18317 	if (len) {
18318 		uint32_t max_val;
18319 		uint32_t moff;
18320 
18321 		if (rack->r_ctl.rc_pace_max_segs)
18322 			max_val = rack->r_ctl.rc_pace_max_segs;
18323 		else if (rack->rc_user_set_max_segs)
18324 			max_val = rack->rc_user_set_max_segs * segsiz;
18325 		else
18326 			max_val = len;
18327 		/*
18328 		 * We allow a limit on sending with hptsi.
18329 		 */
18330 		if (len > max_val) {
18331 			mark = 7;
18332 			len = max_val;
18333 		}
18334 #ifdef INET6
18335 		if (MHLEN < hdrlen + max_linkhdr)
18336 			m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR);
18337 		else
18338 #endif
18339 			m = m_gethdr(M_NOWAIT, MT_DATA);
18340 
18341 		if (m == NULL) {
18342 			SOCKBUF_UNLOCK(sb);
18343 			error = ENOBUFS;
18344 			sack_rxmit = 0;
18345 			goto out;
18346 		}
18347 		m->m_data += max_linkhdr;
18348 		m->m_len = hdrlen;
18349 
18350 		/*
18351 		 * Start the m_copy functions from the closest mbuf to the
18352 		 * sb_offset in the socket buffer chain.
18353 		 */
18354 		mb = sbsndptr_noadv(sb, sb_offset, &moff);
18355 		s_mb = mb;
18356 		s_moff = moff;
18357 		if (len <= MHLEN - hdrlen - max_linkhdr && !hw_tls) {
18358 			m_copydata(mb, moff, (int)len,
18359 				   mtod(m, caddr_t)+hdrlen);
18360 			if (SEQ_LT(tp->snd_nxt, tp->snd_max))
18361 				sbsndptr_adv(sb, mb, len);
18362 			m->m_len += len;
18363 		} else {
18364 			struct sockbuf *msb;
18365 
18366 			if (SEQ_LT(tp->snd_nxt, tp->snd_max))
18367 				msb = NULL;
18368 			else
18369 				msb = sb;
18370 			m->m_next = tcp_m_copym(
18371 				mb, moff, &len,
18372 				if_hw_tsomaxsegcount, if_hw_tsomaxsegsize, msb,
18373 				((rsm == NULL) ? hw_tls : 0)
18374 #ifdef NETFLIX_COPY_ARGS
18375 				, &s_mb, &s_moff
18376 #endif
18377 				);
18378 			if (len <= (tp->t_maxseg - optlen)) {
18379 				/*
18380 				 * Must have ran out of mbufs for the copy
18381 				 * shorten it to no longer need tso. Lets
18382 				 * not put on sendalot since we are low on
18383 				 * mbufs.
18384 				 */
18385 				tso = 0;
18386 			}
18387 			if (m->m_next == NULL) {
18388 				SOCKBUF_UNLOCK(sb);
18389 				(void)m_free(m);
18390 				error = ENOBUFS;
18391 				sack_rxmit = 0;
18392 				goto out;
18393 			}
18394 		}
18395 		if (SEQ_LT(tp->snd_nxt, tp->snd_max) || sack_rxmit) {
18396 			if (rsm && (rsm->r_flags & RACK_TLP)) {
18397 				/*
18398 				 * TLP should not count in retran count, but
18399 				 * in its own bin
18400 				 */
18401 				counter_u64_add(rack_tlp_retran, 1);
18402 				counter_u64_add(rack_tlp_retran_bytes, len);
18403 			} else {
18404 				tp->t_sndrexmitpack++;
18405 				KMOD_TCPSTAT_INC(tcps_sndrexmitpack);
18406 				KMOD_TCPSTAT_ADD(tcps_sndrexmitbyte, len);
18407 			}
18408 #ifdef STATS
18409 			stats_voi_update_abs_u32(tp->t_stats, VOI_TCP_RETXPB,
18410 						 len);
18411 #endif
18412 		} else {
18413 			KMOD_TCPSTAT_INC(tcps_sndpack);
18414 			KMOD_TCPSTAT_ADD(tcps_sndbyte, len);
18415 #ifdef STATS
18416 			stats_voi_update_abs_u64(tp->t_stats, VOI_TCP_TXPB,
18417 						 len);
18418 #endif
18419 		}
18420 		/*
18421 		 * If we're sending everything we've got, set PUSH. (This
18422 		 * will keep happy those implementations which only give
18423 		 * data to the user when a buffer fills or a PUSH comes in.)
18424 		 */
18425 		if (sb_offset + len == sbused(sb) &&
18426 		    sbused(sb) &&
18427 		    !(flags & TH_SYN)) {
18428 			flags |= TH_PUSH;
18429 			add_flag |= RACK_HAD_PUSH;
18430 		}
18431 
18432 		SOCKBUF_UNLOCK(sb);
18433 	} else {
18434 		SOCKBUF_UNLOCK(sb);
18435 		if (tp->t_flags & TF_ACKNOW)
18436 			KMOD_TCPSTAT_INC(tcps_sndacks);
18437 		else if (flags & (TH_SYN | TH_FIN | TH_RST))
18438 			KMOD_TCPSTAT_INC(tcps_sndctrl);
18439 		else
18440 			KMOD_TCPSTAT_INC(tcps_sndwinup);
18441 
18442 		m = m_gethdr(M_NOWAIT, MT_DATA);
18443 		if (m == NULL) {
18444 			error = ENOBUFS;
18445 			sack_rxmit = 0;
18446 			goto out;
18447 		}
18448 #ifdef INET6
18449 		if (isipv6 && (MHLEN < hdrlen + max_linkhdr) &&
18450 		    MHLEN >= hdrlen) {
18451 			M_ALIGN(m, hdrlen);
18452 		} else
18453 #endif
18454 			m->m_data += max_linkhdr;
18455 		m->m_len = hdrlen;
18456 	}
18457 	SOCKBUF_UNLOCK_ASSERT(sb);
18458 	m->m_pkthdr.rcvif = (struct ifnet *)0;
18459 #ifdef MAC
18460 	mac_inpcb_create_mbuf(inp, m);
18461 #endif
18462 	if ((ipoptlen == 0) && (rack->r_ctl.fsb.tcp_ip_hdr) &&  rack->r_fsb_inited) {
18463 #ifdef INET6
18464 		if (isipv6)
18465 			ip6 = (struct ip6_hdr *)rack->r_ctl.fsb.tcp_ip_hdr;
18466 		else
18467 #endif				/* INET6 */
18468 			ip = (struct ip *)rack->r_ctl.fsb.tcp_ip_hdr;
18469 		th = rack->r_ctl.fsb.th;
18470 		udp = rack->r_ctl.fsb.udp;
18471 		if (udp) {
18472 #ifdef INET6
18473 			if (isipv6)
18474 				ulen = hdrlen + len - sizeof(struct ip6_hdr);
18475 			else
18476 #endif				/* INET6 */
18477 				ulen = hdrlen + len - sizeof(struct ip);
18478 			udp->uh_ulen = htons(ulen);
18479 		}
18480 	} else {
18481 #ifdef INET6
18482 		if (isipv6) {
18483 			ip6 = mtod(m, struct ip6_hdr *);
18484 			if (tp->t_port) {
18485 				udp = (struct udphdr *)((caddr_t)ip6 + sizeof(struct ip6_hdr));
18486 				udp->uh_sport = htons(V_tcp_udp_tunneling_port);
18487 				udp->uh_dport = tp->t_port;
18488 				ulen = hdrlen + len - sizeof(struct ip6_hdr);
18489 				udp->uh_ulen = htons(ulen);
18490 				th = (struct tcphdr *)(udp + 1);
18491 			} else
18492 				th = (struct tcphdr *)(ip6 + 1);
18493 			tcpip_fillheaders(inp, tp->t_port, ip6, th);
18494 		} else
18495 #endif				/* INET6 */
18496 		{
18497 			ip = mtod(m, struct ip *);
18498 			if (tp->t_port) {
18499 				udp = (struct udphdr *)((caddr_t)ip + sizeof(struct ip));
18500 				udp->uh_sport = htons(V_tcp_udp_tunneling_port);
18501 				udp->uh_dport = tp->t_port;
18502 				ulen = hdrlen + len - sizeof(struct ip);
18503 				udp->uh_ulen = htons(ulen);
18504 				th = (struct tcphdr *)(udp + 1);
18505 			} else
18506 				th = (struct tcphdr *)(ip + 1);
18507 			tcpip_fillheaders(inp, tp->t_port, ip, th);
18508 		}
18509 	}
18510 	/*
18511 	 * Fill in fields, remembering maximum advertised window for use in
18512 	 * delaying messages about window sizes. If resending a FIN, be sure
18513 	 * not to use a new sequence number.
18514 	 */
18515 	if (flags & TH_FIN && tp->t_flags & TF_SENTFIN &&
18516 	    tp->snd_nxt == tp->snd_max)
18517 		tp->snd_nxt--;
18518 	/*
18519 	 * If we are starting a connection, send ECN setup SYN packet. If we
18520 	 * are on a retransmit, we may resend those bits a number of times
18521 	 * as per RFC 3168.
18522 	 */
18523 	if (tp->t_state == TCPS_SYN_SENT && V_tcp_do_ecn) {
18524 		flags |= tcp_ecn_output_syn_sent(tp);
18525 	}
18526 	/* Also handle parallel SYN for ECN */
18527 	if (TCPS_HAVERCVDSYN(tp->t_state) &&
18528 	    (tp->t_flags2 & (TF2_ECN_PERMIT | TF2_ACE_PERMIT))) {
18529 		int ect = tcp_ecn_output_established(tp, &flags, len, sack_rxmit);
18530 		if ((tp->t_state == TCPS_SYN_RECEIVED) &&
18531 		    (tp->t_flags2 & TF2_ECN_SND_ECE))
18532 			tp->t_flags2 &= ~TF2_ECN_SND_ECE;
18533 #ifdef INET6
18534 		if (isipv6) {
18535 			ip6->ip6_flow &= ~htonl(IPTOS_ECN_MASK << 20);
18536 			ip6->ip6_flow |= htonl(ect << 20);
18537 		}
18538 		else
18539 #endif
18540 		{
18541 			ip->ip_tos &= ~IPTOS_ECN_MASK;
18542 			ip->ip_tos |= ect;
18543 		}
18544 	}
18545 	/*
18546 	 * If we are doing retransmissions, then snd_nxt will not reflect
18547 	 * the first unsent octet.  For ACK only packets, we do not want the
18548 	 * sequence number of the retransmitted packet, we want the sequence
18549 	 * number of the next unsent octet.  So, if there is no data (and no
18550 	 * SYN or FIN), use snd_max instead of snd_nxt when filling in
18551 	 * ti_seq.  But if we are in persist state, snd_max might reflect
18552 	 * one byte beyond the right edge of the window, so use snd_nxt in
18553 	 * that case, since we know we aren't doing a retransmission.
18554 	 * (retransmit and persist are mutually exclusive...)
18555 	 */
18556 	if (sack_rxmit == 0) {
18557 		if (len || (flags & (TH_SYN | TH_FIN))) {
18558 			th->th_seq = htonl(tp->snd_nxt);
18559 			rack_seq = tp->snd_nxt;
18560 		} else {
18561 			th->th_seq = htonl(tp->snd_max);
18562 			rack_seq = tp->snd_max;
18563 		}
18564 	} else {
18565 		th->th_seq = htonl(rsm->r_start);
18566 		rack_seq = rsm->r_start;
18567 	}
18568 	th->th_ack = htonl(tp->rcv_nxt);
18569 	tcp_set_flags(th, flags);
18570 	/*
18571 	 * Calculate receive window.  Don't shrink window, but avoid silly
18572 	 * window syndrome.
18573 	 * If a RST segment is sent, advertise a window of zero.
18574 	 */
18575 	if (flags & TH_RST) {
18576 		recwin = 0;
18577 	} else {
18578 		if (recwin < (long)(so->so_rcv.sb_hiwat / 4) &&
18579 		    recwin < (long)segsiz) {
18580 			recwin = 0;
18581 		}
18582 		if (SEQ_GT(tp->rcv_adv, tp->rcv_nxt) &&
18583 		    recwin < (long)(tp->rcv_adv - tp->rcv_nxt))
18584 			recwin = (long)(tp->rcv_adv - tp->rcv_nxt);
18585 	}
18586 
18587 	/*
18588 	 * According to RFC1323 the window field in a SYN (i.e., a <SYN> or
18589 	 * <SYN,ACK>) segment itself is never scaled.  The <SYN,ACK> case is
18590 	 * handled in syncache.
18591 	 */
18592 	if (flags & TH_SYN)
18593 		th->th_win = htons((u_short)
18594 				   (min(sbspace(&so->so_rcv), TCP_MAXWIN)));
18595 	else {
18596 		/* Avoid shrinking window with window scaling. */
18597 		recwin = roundup2(recwin, 1 << tp->rcv_scale);
18598 		th->th_win = htons((u_short)(recwin >> tp->rcv_scale));
18599 	}
18600 	/*
18601 	 * Adjust the RXWIN0SENT flag - indicate that we have advertised a 0
18602 	 * window.  This may cause the remote transmitter to stall.  This
18603 	 * flag tells soreceive() to disable delayed acknowledgements when
18604 	 * draining the buffer.  This can occur if the receiver is
18605 	 * attempting to read more data than can be buffered prior to
18606 	 * transmitting on the connection.
18607 	 */
18608 	if (th->th_win == 0) {
18609 		tp->t_sndzerowin++;
18610 		tp->t_flags |= TF_RXWIN0SENT;
18611 	} else
18612 		tp->t_flags &= ~TF_RXWIN0SENT;
18613 	tp->snd_up = tp->snd_una;	/* drag it along, its deprecated */
18614 	/* Now are we using fsb?, if so copy the template data to the mbuf */
18615 	if ((ipoptlen == 0) && (rack->r_ctl.fsb.tcp_ip_hdr) && rack->r_fsb_inited) {
18616 		uint8_t *cpto;
18617 
18618 		cpto = mtod(m, uint8_t *);
18619 		memcpy(cpto, rack->r_ctl.fsb.tcp_ip_hdr, rack->r_ctl.fsb.tcp_ip_hdr_len);
18620 		/*
18621 		 * We have just copied in:
18622 		 * IP/IP6
18623 		 * <optional udphdr>
18624 		 * tcphdr (no options)
18625 		 *
18626 		 * We need to grab the correct pointers into the mbuf
18627 		 * for both the tcp header, and possibly the udp header (if tunneling).
18628 		 * We do this by using the offset in the copy buffer and adding it
18629 		 * to the mbuf base pointer (cpto).
18630 		 */
18631 #ifdef INET6
18632 		if (isipv6)
18633 			ip6 = mtod(m, struct ip6_hdr *);
18634 		else
18635 #endif				/* INET6 */
18636 			ip = mtod(m, struct ip *);
18637 		th = (struct tcphdr *)(cpto + ((uint8_t *)rack->r_ctl.fsb.th - rack->r_ctl.fsb.tcp_ip_hdr));
18638 		/* If we have a udp header lets set it into the mbuf as well */
18639 		if (udp)
18640 			udp = (struct udphdr *)(cpto + ((uint8_t *)rack->r_ctl.fsb.udp - rack->r_ctl.fsb.tcp_ip_hdr));
18641 	}
18642 #if defined(IPSEC_SUPPORT) || defined(TCP_SIGNATURE)
18643 	if (to.to_flags & TOF_SIGNATURE) {
18644 		/*
18645 		 * Calculate MD5 signature and put it into the place
18646 		 * determined before.
18647 		 * NOTE: since TCP options buffer doesn't point into
18648 		 * mbuf's data, calculate offset and use it.
18649 		 */
18650 		if (!TCPMD5_ENABLED() || TCPMD5_OUTPUT(m, th,
18651 						       (u_char *)(th + 1) + (to.to_signature - opt)) != 0) {
18652 			/*
18653 			 * Do not send segment if the calculation of MD5
18654 			 * digest has failed.
18655 			 */
18656 			goto out;
18657 		}
18658 	}
18659 #endif
18660 	if (optlen) {
18661 		bcopy(opt, th + 1, optlen);
18662 		th->th_off = (sizeof(struct tcphdr) + optlen) >> 2;
18663 	}
18664 	/*
18665 	 * Put TCP length in extended header, and then checksum extended
18666 	 * header and data.
18667 	 */
18668 	m->m_pkthdr.len = hdrlen + len;	/* in6_cksum() need this */
18669 #ifdef INET6
18670 	if (isipv6) {
18671 		/*
18672 		 * ip6_plen is not need to be filled now, and will be filled
18673 		 * in ip6_output.
18674 		 */
18675 		if (tp->t_port) {
18676 			m->m_pkthdr.csum_flags = CSUM_UDP_IPV6;
18677 			m->m_pkthdr.csum_data = offsetof(struct udphdr, uh_sum);
18678 			udp->uh_sum = in6_cksum_pseudo(ip6, ulen, IPPROTO_UDP, 0);
18679 			th->th_sum = htons(0);
18680 			UDPSTAT_INC(udps_opackets);
18681 		} else {
18682 			m->m_pkthdr.csum_flags = CSUM_TCP_IPV6;
18683 			m->m_pkthdr.csum_data = offsetof(struct tcphdr, th_sum);
18684 			th->th_sum = in6_cksum_pseudo(ip6,
18685 						      sizeof(struct tcphdr) + optlen + len, IPPROTO_TCP,
18686 						      0);
18687 		}
18688 	}
18689 #endif
18690 #if defined(INET6) && defined(INET)
18691 	else
18692 #endif
18693 #ifdef INET
18694 	{
18695 		if (tp->t_port) {
18696 			m->m_pkthdr.csum_flags = CSUM_UDP;
18697 			m->m_pkthdr.csum_data = offsetof(struct udphdr, uh_sum);
18698 			udp->uh_sum = in_pseudo(ip->ip_src.s_addr,
18699 						ip->ip_dst.s_addr, htons(ulen + IPPROTO_UDP));
18700 			th->th_sum = htons(0);
18701 			UDPSTAT_INC(udps_opackets);
18702 		} else {
18703 			m->m_pkthdr.csum_flags = CSUM_TCP;
18704 			m->m_pkthdr.csum_data = offsetof(struct tcphdr, th_sum);
18705 			th->th_sum = in_pseudo(ip->ip_src.s_addr,
18706 					       ip->ip_dst.s_addr, htons(sizeof(struct tcphdr) +
18707 									IPPROTO_TCP + len + optlen));
18708 		}
18709 		/* IP version must be set here for ipv4/ipv6 checking later */
18710 		KASSERT(ip->ip_v == IPVERSION,
18711 			("%s: IP version incorrect: %d", __func__, ip->ip_v));
18712 	}
18713 #endif
18714 	/*
18715 	 * Enable TSO and specify the size of the segments. The TCP pseudo
18716 	 * header checksum is always provided. XXX: Fixme: This is currently
18717 	 * not the case for IPv6.
18718 	 */
18719 	if (tso) {
18720 		KASSERT(len > tp->t_maxseg - optlen,
18721 			("%s: len <= tso_segsz", __func__));
18722 		m->m_pkthdr.csum_flags |= CSUM_TSO;
18723 		m->m_pkthdr.tso_segsz = tp->t_maxseg - optlen;
18724 	}
18725 	KASSERT(len + hdrlen == m_length(m, NULL),
18726 		("%s: mbuf chain different than expected: %d + %u != %u",
18727 		 __func__, len, hdrlen, m_length(m, NULL)));
18728 
18729 #ifdef TCP_HHOOK
18730 	/* Run HHOOK_TCP_ESTABLISHED_OUT helper hooks. */
18731 	hhook_run_tcp_est_out(tp, th, &to, len, tso);
18732 #endif
18733 	/* We're getting ready to send; log now. */
18734 	if (tp->t_logstate != TCP_LOG_STATE_OFF) {
18735 		union tcp_log_stackspecific log;
18736 
18737 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
18738 		log.u_bbr.inhpts = tcp_in_hpts(rack->rc_inp);
18739 		if (rack->rack_no_prr)
18740 			log.u_bbr.flex1 = 0;
18741 		else
18742 			log.u_bbr.flex1 = rack->r_ctl.rc_prr_sndcnt;
18743 		log.u_bbr.flex2 = rack->r_ctl.rc_pace_min_segs;
18744 		log.u_bbr.flex3 = rack->r_ctl.rc_pace_max_segs;
18745 		log.u_bbr.flex4 = orig_len;
18746 		/* Save off the early/late values */
18747 		log.u_bbr.flex6 = rack->r_ctl.rc_agg_early;
18748 		log.u_bbr.applimited = rack->r_ctl.rc_agg_delayed;
18749 		log.u_bbr.bw_inuse = rack_get_bw(rack);
18750 		log.u_bbr.flex8 = 0;
18751 		if (rsm) {
18752 			if (rsm->r_flags & RACK_RWND_COLLAPSED) {
18753 				rack_log_collapse(rack, rsm->r_start, rsm->r_end, 0, __LINE__, 5, rsm->r_flags, rsm);
18754 				counter_u64_add(rack_collapsed_win_rxt, 1);
18755 				counter_u64_add(rack_collapsed_win_rxt_bytes, (rsm->r_end - rsm->r_start));
18756 			}
18757 			if (doing_tlp)
18758 				log.u_bbr.flex8 = 2;
18759 			else
18760 				log.u_bbr.flex8 = 1;
18761 		} else {
18762 			if (doing_tlp)
18763 				log.u_bbr.flex8 = 3;
18764 			else
18765 				log.u_bbr.flex8 = 0;
18766 		}
18767 		log.u_bbr.pacing_gain = rack_get_output_gain(rack, rsm);
18768 		log.u_bbr.flex7 = mark;
18769 		log.u_bbr.flex7 <<= 8;
18770 		log.u_bbr.flex7 |= pass;
18771 		log.u_bbr.pkts_out = tp->t_maxseg;
18772 		log.u_bbr.timeStamp = cts;
18773 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
18774 		log.u_bbr.lt_epoch = cwnd_to_use;
18775 		log.u_bbr.delivered = sendalot;
18776 		lgb = tcp_log_event_(tp, th, &so->so_rcv, &so->so_snd, TCP_LOG_OUT, ERRNO_UNK,
18777 				     len, &log, false, NULL, NULL, 0, &tv);
18778 	} else
18779 		lgb = NULL;
18780 
18781 	/*
18782 	 * Fill in IP length and desired time to live and send to IP level.
18783 	 * There should be a better way to handle ttl and tos; we could keep
18784 	 * them in the template, but need a way to checksum without them.
18785 	 */
18786 	/*
18787 	 * m->m_pkthdr.len should have been set before cksum calcuration,
18788 	 * because in6_cksum() need it.
18789 	 */
18790 #ifdef INET6
18791 	if (isipv6) {
18792 		/*
18793 		 * we separately set hoplimit for every segment, since the
18794 		 * user might want to change the value via setsockopt. Also,
18795 		 * desired default hop limit might be changed via Neighbor
18796 		 * Discovery.
18797 		 */
18798 		rack->r_ctl.fsb.hoplimit = ip6->ip6_hlim = in6_selecthlim(inp, NULL);
18799 
18800 		/*
18801 		 * Set the packet size here for the benefit of DTrace
18802 		 * probes. ip6_output() will set it properly; it's supposed
18803 		 * to include the option header lengths as well.
18804 		 */
18805 		ip6->ip6_plen = htons(m->m_pkthdr.len - sizeof(*ip6));
18806 
18807 		if (V_path_mtu_discovery && tp->t_maxseg > V_tcp_minmss)
18808 			tp->t_flags2 |= TF2_PLPMTU_PMTUD;
18809 		else
18810 			tp->t_flags2 &= ~TF2_PLPMTU_PMTUD;
18811 
18812 		if (tp->t_state == TCPS_SYN_SENT)
18813 			TCP_PROBE5(connect__request, NULL, tp, ip6, tp, th);
18814 
18815 		TCP_PROBE5(send, NULL, tp, ip6, tp, th);
18816 		/* TODO: IPv6 IP6TOS_ECT bit on */
18817 		error = ip6_output(m,
18818 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
18819 				   inp->in6p_outputopts,
18820 #else
18821 				   NULL,
18822 #endif
18823 				   &inp->inp_route6,
18824 				   ((rsm || sack_rxmit) ? IP_NO_SND_TAG_RL : 0),
18825 				   NULL, NULL, inp);
18826 
18827 		if (error == EMSGSIZE && inp->inp_route6.ro_nh != NULL)
18828 			mtu = inp->inp_route6.ro_nh->nh_mtu;
18829 	}
18830 #endif				/* INET6 */
18831 #if defined(INET) && defined(INET6)
18832 	else
18833 #endif
18834 #ifdef INET
18835 	{
18836 		ip->ip_len = htons(m->m_pkthdr.len);
18837 #ifdef INET6
18838 		if (inp->inp_vflag & INP_IPV6PROTO)
18839 			ip->ip_ttl = in6_selecthlim(inp, NULL);
18840 #endif				/* INET6 */
18841 		rack->r_ctl.fsb.hoplimit = ip->ip_ttl;
18842 		/*
18843 		 * If we do path MTU discovery, then we set DF on every
18844 		 * packet. This might not be the best thing to do according
18845 		 * to RFC3390 Section 2. However the tcp hostcache migitates
18846 		 * the problem so it affects only the first tcp connection
18847 		 * with a host.
18848 		 *
18849 		 * NB: Don't set DF on small MTU/MSS to have a safe
18850 		 * fallback.
18851 		 */
18852 		if (V_path_mtu_discovery && tp->t_maxseg > V_tcp_minmss) {
18853 			tp->t_flags2 |= TF2_PLPMTU_PMTUD;
18854 			if (tp->t_port == 0 || len < V_tcp_minmss) {
18855 				ip->ip_off |= htons(IP_DF);
18856 			}
18857 		} else {
18858 			tp->t_flags2 &= ~TF2_PLPMTU_PMTUD;
18859 		}
18860 
18861 		if (tp->t_state == TCPS_SYN_SENT)
18862 			TCP_PROBE5(connect__request, NULL, tp, ip, tp, th);
18863 
18864 		TCP_PROBE5(send, NULL, tp, ip, tp, th);
18865 
18866 		error = ip_output(m,
18867 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
18868 				  inp->inp_options,
18869 #else
18870 				  NULL,
18871 #endif
18872 				  &inp->inp_route,
18873 				  ((rsm || sack_rxmit) ? IP_NO_SND_TAG_RL : 0), 0,
18874 				  inp);
18875 		if (error == EMSGSIZE && inp->inp_route.ro_nh != NULL)
18876 			mtu = inp->inp_route.ro_nh->nh_mtu;
18877 	}
18878 #endif				/* INET */
18879 
18880 out:
18881 	if (lgb) {
18882 		lgb->tlb_errno = error;
18883 		lgb = NULL;
18884 	}
18885 	/*
18886 	 * In transmit state, time the transmission and arrange for the
18887 	 * retransmit.  In persist state, just set snd_max.
18888 	 */
18889 	if (error == 0) {
18890 		tcp_account_for_send(tp, len, (rsm != NULL), doing_tlp, hw_tls);
18891 		if (rsm && doing_tlp) {
18892 			rack->rc_last_sent_tlp_past_cumack = 0;
18893 			rack->rc_last_sent_tlp_seq_valid = 1;
18894 			rack->r_ctl.last_sent_tlp_seq = rsm->r_start;
18895 			rack->r_ctl.last_sent_tlp_len = rsm->r_end - rsm->r_start;
18896 		}
18897 		rack->forced_ack = 0;	/* If we send something zap the FA flag */
18898 		if (rsm && (doing_tlp == 0)) {
18899 			/* Set we retransmitted */
18900 			rack->rc_gp_saw_rec = 1;
18901 		} else {
18902 			if (cwnd_to_use > tp->snd_ssthresh) {
18903 				/* Set we sent in CA */
18904 				rack->rc_gp_saw_ca = 1;
18905 			} else {
18906 				/* Set we sent in SS */
18907 				rack->rc_gp_saw_ss = 1;
18908 			}
18909 		}
18910 		if (TCPS_HAVEESTABLISHED(tp->t_state) &&
18911 		    (tp->t_flags & TF_SACK_PERMIT) &&
18912 		    tp->rcv_numsacks > 0)
18913 			tcp_clean_dsack_blocks(tp);
18914 		tot_len_this_send += len;
18915 		if (len == 0)
18916 			counter_u64_add(rack_out_size[TCP_MSS_ACCT_SNDACK], 1);
18917 		else if (len == 1) {
18918 			counter_u64_add(rack_out_size[TCP_MSS_ACCT_PERSIST], 1);
18919 		} else if (len > 1) {
18920 			int idx;
18921 
18922 			idx = (len / segsiz) + 3;
18923 			if (idx >= TCP_MSS_ACCT_ATIMER)
18924 				counter_u64_add(rack_out_size[(TCP_MSS_ACCT_ATIMER-1)], 1);
18925 			else
18926 				counter_u64_add(rack_out_size[idx], 1);
18927 		}
18928 	}
18929 	if ((rack->rack_no_prr == 0) &&
18930 	    sub_from_prr &&
18931 	    (error == 0)) {
18932 		if (rack->r_ctl.rc_prr_sndcnt >= len)
18933 			rack->r_ctl.rc_prr_sndcnt -= len;
18934 		else
18935 			rack->r_ctl.rc_prr_sndcnt = 0;
18936 	}
18937 	sub_from_prr = 0;
18938 	if (doing_tlp) {
18939 		/* Make sure the TLP is added */
18940 		add_flag |= RACK_TLP;
18941 	} else if (rsm) {
18942 		/* If its a resend without TLP then it must not have the flag */
18943 		rsm->r_flags &= ~RACK_TLP;
18944 	}
18945 	rack_log_output(tp, &to, len, rack_seq, (uint8_t) flags, error,
18946 			rack_to_usec_ts(&tv),
18947 			rsm, add_flag, s_mb, s_moff, hw_tls);
18948 
18949 
18950 	if ((error == 0) &&
18951 	    (len > 0) &&
18952 	    (tp->snd_una == tp->snd_max))
18953 		rack->r_ctl.rc_tlp_rxt_last_time = cts;
18954 	{
18955 		tcp_seq startseq = tp->snd_nxt;
18956 
18957 		/* Track our lost count */
18958 		if (rsm && (doing_tlp == 0))
18959 			rack->r_ctl.rc_loss_count += rsm->r_end - rsm->r_start;
18960 		/*
18961 		 * Advance snd_nxt over sequence space of this segment.
18962 		 */
18963 		if (error)
18964 			/* We don't log or do anything with errors */
18965 			goto nomore;
18966 		if (doing_tlp == 0) {
18967 			if (rsm == NULL) {
18968 				/*
18969 				 * Not a retransmission of some
18970 				 * sort, new data is going out so
18971 				 * clear our TLP count and flag.
18972 				 */
18973 				rack->rc_tlp_in_progress = 0;
18974 				rack->r_ctl.rc_tlp_cnt_out = 0;
18975 			}
18976 		} else {
18977 			/*
18978 			 * We have just sent a TLP, mark that it is true
18979 			 * and make sure our in progress is set so we
18980 			 * continue to check the count.
18981 			 */
18982 			rack->rc_tlp_in_progress = 1;
18983 			rack->r_ctl.rc_tlp_cnt_out++;
18984 		}
18985 		if (flags & (TH_SYN | TH_FIN)) {
18986 			if (flags & TH_SYN)
18987 				tp->snd_nxt++;
18988 			if (flags & TH_FIN) {
18989 				tp->snd_nxt++;
18990 				tp->t_flags |= TF_SENTFIN;
18991 			}
18992 		}
18993 		/* In the ENOBUFS case we do *not* update snd_max */
18994 		if (sack_rxmit)
18995 			goto nomore;
18996 
18997 		tp->snd_nxt += len;
18998 		if (SEQ_GT(tp->snd_nxt, tp->snd_max)) {
18999 			if (tp->snd_una == tp->snd_max) {
19000 				/*
19001 				 * Update the time we just added data since
19002 				 * none was outstanding.
19003 				 */
19004 				rack_log_progress_event(rack, tp, ticks, PROGRESS_START, __LINE__);
19005 				tp->t_acktime = ticks;
19006 			}
19007 			tp->snd_max = tp->snd_nxt;
19008 			/*
19009 			 * Time this transmission if not a retransmission and
19010 			 * not currently timing anything.
19011 			 * This is only relevant in case of switching back to
19012 			 * the base stack.
19013 			 */
19014 			if (tp->t_rtttime == 0) {
19015 				tp->t_rtttime = ticks;
19016 				tp->t_rtseq = startseq;
19017 				KMOD_TCPSTAT_INC(tcps_segstimed);
19018 			}
19019 			if (len &&
19020 			    ((tp->t_flags & TF_GPUTINPROG) == 0))
19021 				rack_start_gp_measurement(tp, rack, startseq, sb_offset);
19022 		}
19023 		/*
19024 		 * If we are doing FO we need to update the mbuf position and subtract
19025 		 * this happens when the peer sends us duplicate information and
19026 		 * we thus want to send a DSACK.
19027 		 *
19028 		 * XXXRRS: This brings to mind a ?, when we send a DSACK block is TSO
19029 		 * turned off? If not then we are going to echo multiple DSACK blocks
19030 		 * out (with the TSO), which we should not be doing.
19031 		 */
19032 		if (rack->r_fast_output && len) {
19033 			if (rack->r_ctl.fsb.left_to_send > len)
19034 				rack->r_ctl.fsb.left_to_send -= len;
19035 			else
19036 				rack->r_ctl.fsb.left_to_send = 0;
19037 			if (rack->r_ctl.fsb.left_to_send < segsiz)
19038 				rack->r_fast_output = 0;
19039 			if (rack->r_fast_output) {
19040 				rack->r_ctl.fsb.m = sbsndmbuf(sb, (tp->snd_max - tp->snd_una), &rack->r_ctl.fsb.off);
19041 				rack->r_ctl.fsb.o_m_len = rack->r_ctl.fsb.m->m_len;
19042 			}
19043 		}
19044 	}
19045 nomore:
19046 	if (error) {
19047 		rack->r_ctl.rc_agg_delayed = 0;
19048 		rack->r_early = 0;
19049 		rack->r_late = 0;
19050 		rack->r_ctl.rc_agg_early = 0;
19051 		SOCKBUF_UNLOCK_ASSERT(sb);	/* Check gotos. */
19052 		/*
19053 		 * Failures do not advance the seq counter above. For the
19054 		 * case of ENOBUFS we will fall out and retry in 1ms with
19055 		 * the hpts. Everything else will just have to retransmit
19056 		 * with the timer.
19057 		 *
19058 		 * In any case, we do not want to loop around for another
19059 		 * send without a good reason.
19060 		 */
19061 		sendalot = 0;
19062 		switch (error) {
19063 		case EPERM:
19064 			tp->t_softerror = error;
19065 #ifdef TCP_ACCOUNTING
19066 			crtsc = get_cyclecount();
19067 			if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
19068 				tp->tcp_cnt_counters[SND_OUT_FAIL]++;
19069 			}
19070 			counter_u64_add(tcp_cnt_counters[SND_OUT_FAIL], 1);
19071 			if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
19072 				tp->tcp_proc_time[SND_OUT_FAIL] += (crtsc - ts_val);
19073 			}
19074 			counter_u64_add(tcp_proc_time[SND_OUT_FAIL], (crtsc - ts_val));
19075 			sched_unpin();
19076 #endif
19077 			return (error);
19078 		case ENOBUFS:
19079 			/*
19080 			 * Pace us right away to retry in a some
19081 			 * time
19082 			 */
19083 			if (rack->r_ctl.crte != NULL) {
19084 				rack_trace_point(rack, RACK_TP_HWENOBUF);
19085 			} else
19086 				rack_trace_point(rack, RACK_TP_ENOBUF);
19087 			slot = ((1 + rack->rc_enobuf) * HPTS_USEC_IN_MSEC);
19088 			if (rack->rc_enobuf < 0x7f)
19089 				rack->rc_enobuf++;
19090 			if (slot < (10 * HPTS_USEC_IN_MSEC))
19091 				slot = 10 * HPTS_USEC_IN_MSEC;
19092 			if (rack->r_ctl.crte != NULL) {
19093 				counter_u64_add(rack_saw_enobuf_hw, 1);
19094 				tcp_rl_log_enobuf(rack->r_ctl.crte);
19095 			}
19096 			counter_u64_add(rack_saw_enobuf, 1);
19097 			goto enobufs;
19098 		case EMSGSIZE:
19099 			/*
19100 			 * For some reason the interface we used initially
19101 			 * to send segments changed to another or lowered
19102 			 * its MTU. If TSO was active we either got an
19103 			 * interface without TSO capabilits or TSO was
19104 			 * turned off. If we obtained mtu from ip_output()
19105 			 * then update it and try again.
19106 			 */
19107 			if (tso)
19108 				tp->t_flags &= ~TF_TSO;
19109 			if (mtu != 0) {
19110 				tcp_mss_update(tp, -1, mtu, NULL, NULL);
19111 				goto again;
19112 			}
19113 			slot = 10 * HPTS_USEC_IN_MSEC;
19114 			rack_start_hpts_timer(rack, tp, cts, slot, 0, 0);
19115 #ifdef TCP_ACCOUNTING
19116 			crtsc = get_cyclecount();
19117 			if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
19118 				tp->tcp_cnt_counters[SND_OUT_FAIL]++;
19119 			}
19120 			counter_u64_add(tcp_cnt_counters[SND_OUT_FAIL], 1);
19121 			if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
19122 				tp->tcp_proc_time[SND_OUT_FAIL] += (crtsc - ts_val);
19123 			}
19124 			counter_u64_add(tcp_proc_time[SND_OUT_FAIL], (crtsc - ts_val));
19125 			sched_unpin();
19126 #endif
19127 			return (error);
19128 		case ENETUNREACH:
19129 			counter_u64_add(rack_saw_enetunreach, 1);
19130 		case EHOSTDOWN:
19131 		case EHOSTUNREACH:
19132 		case ENETDOWN:
19133 			if (TCPS_HAVERCVDSYN(tp->t_state)) {
19134 				tp->t_softerror = error;
19135 			}
19136 			/* FALLTHROUGH */
19137 		default:
19138 			slot = 10 * HPTS_USEC_IN_MSEC;
19139 			rack_start_hpts_timer(rack, tp, cts, slot, 0, 0);
19140 #ifdef TCP_ACCOUNTING
19141 			crtsc = get_cyclecount();
19142 			if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
19143 				tp->tcp_cnt_counters[SND_OUT_FAIL]++;
19144 			}
19145 			counter_u64_add(tcp_cnt_counters[SND_OUT_FAIL], 1);
19146 			if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
19147 				tp->tcp_proc_time[SND_OUT_FAIL] += (crtsc - ts_val);
19148 			}
19149 			counter_u64_add(tcp_proc_time[SND_OUT_FAIL], (crtsc - ts_val));
19150 			sched_unpin();
19151 #endif
19152 			return (error);
19153 		}
19154 	} else {
19155 		rack->rc_enobuf = 0;
19156 		if (IN_FASTRECOVERY(tp->t_flags) && rsm)
19157 			rack->r_ctl.retran_during_recovery += len;
19158 	}
19159 	KMOD_TCPSTAT_INC(tcps_sndtotal);
19160 
19161 	/*
19162 	 * Data sent (as far as we can tell). If this advertises a larger
19163 	 * window than any other segment, then remember the size of the
19164 	 * advertised window. Any pending ACK has now been sent.
19165 	 */
19166 	if (recwin > 0 && SEQ_GT(tp->rcv_nxt + recwin, tp->rcv_adv))
19167 		tp->rcv_adv = tp->rcv_nxt + recwin;
19168 
19169 	tp->last_ack_sent = tp->rcv_nxt;
19170 	tp->t_flags &= ~(TF_ACKNOW | TF_DELACK);
19171 enobufs:
19172 	if (sendalot) {
19173 		/* Do we need to turn off sendalot? */
19174 		if (rack->r_ctl.rc_pace_max_segs &&
19175 		    (tot_len_this_send >= rack->r_ctl.rc_pace_max_segs)) {
19176 			/* We hit our max. */
19177 			sendalot = 0;
19178 		} else if ((rack->rc_user_set_max_segs) &&
19179 			   (tot_len_this_send >= (rack->rc_user_set_max_segs * segsiz))) {
19180 			/* We hit the user defined max */
19181 			sendalot = 0;
19182 		}
19183 	}
19184 	if ((error == 0) && (flags & TH_FIN))
19185 		tcp_log_end_status(tp, TCP_EI_STATUS_SERVER_FIN);
19186 	if (flags & TH_RST) {
19187 		/*
19188 		 * We don't send again after sending a RST.
19189 		 */
19190 		slot = 0;
19191 		sendalot = 0;
19192 		if (error == 0)
19193 			tcp_log_end_status(tp, TCP_EI_STATUS_SERVER_RST);
19194 	} else if ((slot == 0) && (sendalot == 0) && tot_len_this_send) {
19195 		/*
19196 		 * Get our pacing rate, if an error
19197 		 * occurred in sending (ENOBUF) we would
19198 		 * hit the else if with slot preset. Other
19199 		 * errors return.
19200 		 */
19201 		slot = rack_get_pacing_delay(rack, tp, tot_len_this_send, rsm, segsiz);
19202 	}
19203 	if (rsm &&
19204 	    (rsm->r_flags & RACK_HAS_SYN) == 0 &&
19205 	    rack->use_rack_rr) {
19206 		/* Its a retransmit and we use the rack cheat? */
19207 		if ((slot == 0) ||
19208 		    (rack->rc_always_pace == 0) ||
19209 		    (rack->r_rr_config == 1)) {
19210 			/*
19211 			 * We have no pacing set or we
19212 			 * are using old-style rack or
19213 			 * we are overridden to use the old 1ms pacing.
19214 			 */
19215 			slot = rack->r_ctl.rc_min_to;
19216 		}
19217 	}
19218 	/* We have sent clear the flag */
19219 	rack->r_ent_rec_ns = 0;
19220 	if (rack->r_must_retran) {
19221 		if (rsm) {
19222 			rack->r_ctl.rc_out_at_rto -= (rsm->r_end - rsm->r_start);
19223 			if (SEQ_GEQ(rsm->r_end, rack->r_ctl.rc_snd_max_at_rto)) {
19224 				/*
19225 				 * We have retransmitted all.
19226 				 */
19227 				rack->r_must_retran = 0;
19228 				rack->r_ctl.rc_out_at_rto = 0;
19229 			}
19230 		} else if (SEQ_GEQ(tp->snd_max, rack->r_ctl.rc_snd_max_at_rto)) {
19231 			/*
19232 			 * Sending new data will also kill
19233 			 * the loop.
19234 			 */
19235 			rack->r_must_retran = 0;
19236 			rack->r_ctl.rc_out_at_rto = 0;
19237 		}
19238 	}
19239 	rack->r_ctl.fsb.recwin = recwin;
19240 	if ((tp->t_flags & (TF_WASCRECOVERY|TF_WASFRECOVERY)) &&
19241 	    SEQ_GT(tp->snd_max, rack->r_ctl.rc_snd_max_at_rto)) {
19242 		/*
19243 		 * We hit an RTO and now have past snd_max at the RTO
19244 		 * clear all the WAS flags.
19245 		 */
19246 		tp->t_flags &= ~(TF_WASCRECOVERY|TF_WASFRECOVERY);
19247 	}
19248 	if (slot) {
19249 		/* set the rack tcb into the slot N */
19250 		if ((error == 0) &&
19251 		    rack_use_rfo &&
19252 		    ((flags & (TH_SYN|TH_FIN)) == 0) &&
19253 		    (rsm == NULL) &&
19254 		    (tp->snd_nxt == tp->snd_max) &&
19255 		    (ipoptlen == 0) &&
19256 		    (tp->rcv_numsacks == 0) &&
19257 		    rack->r_fsb_inited &&
19258 		    TCPS_HAVEESTABLISHED(tp->t_state) &&
19259 		    (rack->r_must_retran == 0) &&
19260 		    ((tp->t_flags & TF_NEEDFIN) == 0) &&
19261 		    (len > 0) && (orig_len > 0) &&
19262 		    (orig_len > len) &&
19263 		    ((orig_len - len) >= segsiz) &&
19264 		    ((optlen == 0) ||
19265 		     ((optlen == TCPOLEN_TSTAMP_APPA) && (to.to_flags & TOF_TS)))) {
19266 			/* We can send at least one more MSS using our fsb */
19267 
19268 			rack->r_fast_output = 1;
19269 			rack->r_ctl.fsb.m = sbsndmbuf(sb, (tp->snd_max - tp->snd_una), &rack->r_ctl.fsb.off);
19270 			rack->r_ctl.fsb.o_m_len = rack->r_ctl.fsb.m->m_len;
19271 			rack->r_ctl.fsb.tcp_flags = flags;
19272 			rack->r_ctl.fsb.left_to_send = orig_len - len;
19273 			if (hw_tls)
19274 				rack->r_ctl.fsb.hw_tls = 1;
19275 			else
19276 				rack->r_ctl.fsb.hw_tls = 0;
19277 			KASSERT((rack->r_ctl.fsb.left_to_send <= (sbavail(sb) - (tp->snd_max - tp->snd_una))),
19278 				("rack:%p left_to_send:%u sbavail:%u out:%u",
19279 				 rack, rack->r_ctl.fsb.left_to_send, sbavail(sb),
19280 				 (tp->snd_max - tp->snd_una)));
19281 			if (rack->r_ctl.fsb.left_to_send < segsiz)
19282 				rack->r_fast_output = 0;
19283 			else {
19284 				if (rack->r_ctl.fsb.left_to_send == (sbavail(sb) - (tp->snd_max - tp->snd_una)))
19285 					rack->r_ctl.fsb.rfo_apply_push = 1;
19286 				else
19287 					rack->r_ctl.fsb.rfo_apply_push = 0;
19288 			}
19289 		} else
19290 			rack->r_fast_output = 0;
19291 		rack_log_fsb(rack, tp, so, flags,
19292 			     ipoptlen, orig_len, len, error,
19293 			     (rsm == NULL), optlen, __LINE__, 2);
19294 	} else if (sendalot) {
19295 		int ret;
19296 
19297 		sack_rxmit = 0;
19298 		if ((error == 0) &&
19299 		    rack_use_rfo &&
19300 		    ((flags & (TH_SYN|TH_FIN)) == 0) &&
19301 		    (rsm == NULL) &&
19302 		    (ipoptlen == 0) &&
19303 		    (tp->rcv_numsacks == 0) &&
19304 		    (tp->snd_nxt == tp->snd_max) &&
19305 		    (rack->r_must_retran == 0) &&
19306 		    rack->r_fsb_inited &&
19307 		    TCPS_HAVEESTABLISHED(tp->t_state) &&
19308 		    ((tp->t_flags & TF_NEEDFIN) == 0) &&
19309 		    (len > 0) && (orig_len > 0) &&
19310 		    (orig_len > len) &&
19311 		    ((orig_len - len) >= segsiz) &&
19312 		    ((optlen == 0) ||
19313 		     ((optlen == TCPOLEN_TSTAMP_APPA) && (to.to_flags & TOF_TS)))) {
19314 			/* we can use fast_output for more */
19315 
19316 			rack->r_fast_output = 1;
19317 			rack->r_ctl.fsb.m = sbsndmbuf(sb, (tp->snd_max - tp->snd_una), &rack->r_ctl.fsb.off);
19318 			rack->r_ctl.fsb.o_m_len = rack->r_ctl.fsb.m->m_len;
19319 			rack->r_ctl.fsb.tcp_flags = flags;
19320 			rack->r_ctl.fsb.left_to_send = orig_len - len;
19321 			if (hw_tls)
19322 				rack->r_ctl.fsb.hw_tls = 1;
19323 			else
19324 				rack->r_ctl.fsb.hw_tls = 0;
19325 			KASSERT((rack->r_ctl.fsb.left_to_send <= (sbavail(sb) - (tp->snd_max - tp->snd_una))),
19326 				("rack:%p left_to_send:%u sbavail:%u out:%u",
19327 				 rack, rack->r_ctl.fsb.left_to_send, sbavail(sb),
19328 				 (tp->snd_max - tp->snd_una)));
19329 			if (rack->r_ctl.fsb.left_to_send < segsiz) {
19330 				rack->r_fast_output = 0;
19331 			}
19332 			if (rack->r_fast_output) {
19333 				if (rack->r_ctl.fsb.left_to_send == (sbavail(sb) - (tp->snd_max - tp->snd_una)))
19334 					rack->r_ctl.fsb.rfo_apply_push = 1;
19335 				else
19336 					rack->r_ctl.fsb.rfo_apply_push = 0;
19337 				rack_log_fsb(rack, tp, so, flags,
19338 					     ipoptlen, orig_len, len, error,
19339 					     (rsm == NULL), optlen, __LINE__, 3);
19340 				error = 0;
19341 				ret = rack_fast_output(tp, rack, ts_val, cts, ms_cts, &tv, tot_len_this_send, &error);
19342 				if (ret >= 0)
19343 					return (ret);
19344 			        else if (error)
19345 					goto nomore;
19346 
19347 			}
19348 		}
19349 		goto again;
19350 	}
19351 	/* Assure when we leave that snd_nxt will point to top */
19352 	if (SEQ_GT(tp->snd_max, tp->snd_nxt))
19353 		tp->snd_nxt = tp->snd_max;
19354 	rack_start_hpts_timer(rack, tp, cts, slot, tot_len_this_send, 0);
19355 #ifdef TCP_ACCOUNTING
19356 	crtsc = get_cyclecount() - ts_val;
19357 	if (tot_len_this_send) {
19358 		if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
19359 			tp->tcp_cnt_counters[SND_OUT_DATA]++;
19360 		}
19361 		counter_u64_add(tcp_cnt_counters[SND_OUT_DATA], 1);
19362 		if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
19363 			tp->tcp_proc_time[SND_OUT_DATA] += crtsc;
19364 		}
19365 		counter_u64_add(tcp_proc_time[SND_OUT_DATA], crtsc);
19366 		if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
19367 			tp->tcp_cnt_counters[CNT_OF_MSS_OUT] += ((tot_len_this_send + segsiz - 1) /segsiz);
19368 		}
19369 		counter_u64_add(tcp_cnt_counters[CNT_OF_MSS_OUT], ((tot_len_this_send + segsiz - 1) /segsiz));
19370 	} else {
19371 		if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
19372 			tp->tcp_cnt_counters[SND_OUT_ACK]++;
19373 		}
19374 		counter_u64_add(tcp_cnt_counters[SND_OUT_ACK], 1);
19375 		if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
19376 			tp->tcp_proc_time[SND_OUT_ACK] += crtsc;
19377 		}
19378 		counter_u64_add(tcp_proc_time[SND_OUT_ACK], crtsc);
19379 	}
19380 	sched_unpin();
19381 #endif
19382 	if (error == ENOBUFS)
19383 		error = 0;
19384 	return (error);
19385 }
19386 
19387 static void
19388 rack_update_seg(struct tcp_rack *rack)
19389 {
19390 	uint32_t orig_val;
19391 
19392 	orig_val = rack->r_ctl.rc_pace_max_segs;
19393 	rack_set_pace_segments(rack->rc_tp, rack, __LINE__, NULL);
19394 	if (orig_val != rack->r_ctl.rc_pace_max_segs)
19395 		rack_log_pacing_delay_calc(rack, 0, 0, orig_val, 0, 0, 15, __LINE__, NULL, 0);
19396 }
19397 
19398 static void
19399 rack_mtu_change(struct tcpcb *tp)
19400 {
19401 	/*
19402 	 * The MSS may have changed
19403 	 */
19404 	struct tcp_rack *rack;
19405 	struct rack_sendmap *rsm;
19406 
19407 	rack = (struct tcp_rack *)tp->t_fb_ptr;
19408 	if (rack->r_ctl.rc_pace_min_segs != ctf_fixed_maxseg(tp)) {
19409 		/*
19410 		 * The MTU has changed we need to resend everything
19411 		 * since all we have sent is lost. We first fix
19412 		 * up the mtu though.
19413 		 */
19414 		rack_set_pace_segments(tp, rack, __LINE__, NULL);
19415 		/* We treat this like a full retransmit timeout without the cwnd adjustment */
19416 		rack_remxt_tmr(tp);
19417 		rack->r_fast_output = 0;
19418 		rack->r_ctl.rc_out_at_rto = ctf_flight_size(tp,
19419 						rack->r_ctl.rc_sacked);
19420 		rack->r_ctl.rc_snd_max_at_rto = tp->snd_max;
19421 		rack->r_must_retran = 1;
19422 		/* Mark all inflight to needing to be rxt'd */
19423 		TAILQ_FOREACH(rsm, &rack->r_ctl.rc_tmap, r_tnext) {
19424 			rsm->r_flags |= RACK_MUST_RXT;
19425 		}
19426 	}
19427 	sack_filter_clear(&rack->r_ctl.rack_sf, tp->snd_una);
19428 	/* We don't use snd_nxt to retransmit */
19429 	tp->snd_nxt = tp->snd_max;
19430 }
19431 
19432 static int
19433 rack_set_profile(struct tcp_rack *rack, int prof)
19434 {
19435 	int err = EINVAL;
19436 	if (prof == 1) {
19437 		/* pace_always=1 */
19438 		if (rack->rc_always_pace == 0) {
19439 			if (tcp_can_enable_pacing() == 0)
19440 				return (EBUSY);
19441 		}
19442 		rack->rc_always_pace = 1;
19443 		if (rack->use_fixed_rate || rack->gp_ready)
19444 			rack_set_cc_pacing(rack);
19445 		rack->rc_inp->inp_flags2 |= INP_SUPPORTS_MBUFQ;
19446 		rack->rack_attempt_hdwr_pace = 0;
19447 		/* cmpack=1 */
19448 		if (rack_use_cmp_acks)
19449 			rack->r_use_cmp_ack = 1;
19450 		if (TCPS_HAVEESTABLISHED(rack->rc_tp->t_state) &&
19451 		    rack->r_use_cmp_ack)
19452 			rack->rc_inp->inp_flags2 |= INP_MBUF_ACKCMP;
19453 		/* scwnd=1 */
19454 		rack->rack_enable_scwnd = 1;
19455 		/* dynamic=100 */
19456 		rack->rc_gp_dyn_mul = 1;
19457 		/* gp_inc_ca */
19458 		rack->r_ctl.rack_per_of_gp_ca = 100;
19459 		/* rrr_conf=3 */
19460 		rack->r_rr_config = 3;
19461 		/* npush=2 */
19462 		rack->r_ctl.rc_no_push_at_mrtt = 2;
19463 		/* fillcw=1 */
19464 		rack->rc_pace_to_cwnd = 1;
19465 		rack->rc_pace_fill_if_rttin_range = 0;
19466 		rack->rtt_limit_mul = 0;
19467 		/* noprr=1 */
19468 		rack->rack_no_prr = 1;
19469 		/* lscwnd=1 */
19470 		rack->r_limit_scw = 1;
19471 		/* gp_inc_rec */
19472 		rack->r_ctl.rack_per_of_gp_rec = 90;
19473 		err = 0;
19474 
19475 	} else if (prof == 3) {
19476 		/* Same as profile one execept fill_cw becomes 2 (less aggressive set) */
19477 		/* pace_always=1 */
19478 		if (rack->rc_always_pace == 0) {
19479 			if (tcp_can_enable_pacing() == 0)
19480 				return (EBUSY);
19481 		}
19482 		rack->rc_always_pace = 1;
19483 		if (rack->use_fixed_rate || rack->gp_ready)
19484 			rack_set_cc_pacing(rack);
19485 		rack->rc_inp->inp_flags2 |= INP_SUPPORTS_MBUFQ;
19486 		rack->rack_attempt_hdwr_pace = 0;
19487 		/* cmpack=1 */
19488 		if (rack_use_cmp_acks)
19489 			rack->r_use_cmp_ack = 1;
19490 		if (TCPS_HAVEESTABLISHED(rack->rc_tp->t_state) &&
19491 		    rack->r_use_cmp_ack)
19492 			rack->rc_inp->inp_flags2 |= INP_MBUF_ACKCMP;
19493 		/* scwnd=1 */
19494 		rack->rack_enable_scwnd = 1;
19495 		/* dynamic=100 */
19496 		rack->rc_gp_dyn_mul = 1;
19497 		/* gp_inc_ca */
19498 		rack->r_ctl.rack_per_of_gp_ca = 100;
19499 		/* rrr_conf=3 */
19500 		rack->r_rr_config = 3;
19501 		/* npush=2 */
19502 		rack->r_ctl.rc_no_push_at_mrtt = 2;
19503 		/* fillcw=2 */
19504 		rack->rc_pace_to_cwnd = 1;
19505 		rack->r_fill_less_agg = 1;
19506 		rack->rc_pace_fill_if_rttin_range = 0;
19507 		rack->rtt_limit_mul = 0;
19508 		/* noprr=1 */
19509 		rack->rack_no_prr = 1;
19510 		/* lscwnd=1 */
19511 		rack->r_limit_scw = 1;
19512 		/* gp_inc_rec */
19513 		rack->r_ctl.rack_per_of_gp_rec = 90;
19514 		err = 0;
19515 
19516 
19517 	} else if (prof == 2) {
19518 		/* cmpack=1 */
19519 		if (rack->rc_always_pace == 0) {
19520 			if (tcp_can_enable_pacing() == 0)
19521 				return (EBUSY);
19522 		}
19523 		rack->rc_always_pace = 1;
19524 		if (rack->use_fixed_rate || rack->gp_ready)
19525 			rack_set_cc_pacing(rack);
19526 		rack->r_use_cmp_ack = 1;
19527 		if (TCPS_HAVEESTABLISHED(rack->rc_tp->t_state))
19528 			rack->rc_inp->inp_flags2 |= INP_MBUF_ACKCMP;
19529 		/* pace_always=1 */
19530 		rack->rc_inp->inp_flags2 |= INP_SUPPORTS_MBUFQ;
19531 		/* scwnd=1 */
19532 		rack->rack_enable_scwnd = 1;
19533 		/* dynamic=100 */
19534 		rack->rc_gp_dyn_mul = 1;
19535 		rack->r_ctl.rack_per_of_gp_ca = 100;
19536 		/* rrr_conf=3 */
19537 		rack->r_rr_config = 3;
19538 		/* npush=2 */
19539 		rack->r_ctl.rc_no_push_at_mrtt = 2;
19540 		/* fillcw=1 */
19541 		rack->rc_pace_to_cwnd = 1;
19542 		rack->rc_pace_fill_if_rttin_range = 0;
19543 		rack->rtt_limit_mul = 0;
19544 		/* noprr=1 */
19545 		rack->rack_no_prr = 1;
19546 		/* lscwnd=0 */
19547 		rack->r_limit_scw = 0;
19548 		err = 0;
19549 	} else if (prof == 0) {
19550 		/* This changes things back to the default settings */
19551 		err = 0;
19552 		if (rack->rc_always_pace) {
19553 			tcp_decrement_paced_conn();
19554 			rack_undo_cc_pacing(rack);
19555 			rack->rc_always_pace = 0;
19556 		}
19557 		if (rack_pace_every_seg && tcp_can_enable_pacing()) {
19558 			rack->rc_always_pace = 1;
19559 			if (rack->use_fixed_rate || rack->gp_ready)
19560 				rack_set_cc_pacing(rack);
19561 		} else
19562 			rack->rc_always_pace = 0;
19563 		if (rack_dsack_std_based & 0x1) {
19564 			/* Basically this means all rack timers are at least (srtt + 1/4 srtt) */
19565 			rack->rc_rack_tmr_std_based = 1;
19566 		}
19567 		if (rack_dsack_std_based & 0x2) {
19568 			/* Basically this means  rack timers are extended based on dsack by up to (2 * srtt) */
19569 			rack->rc_rack_use_dsack = 1;
19570 		}
19571 		if (rack_use_cmp_acks)
19572 			rack->r_use_cmp_ack = 1;
19573 		else
19574 			rack->r_use_cmp_ack = 0;
19575 		if (rack_disable_prr)
19576 			rack->rack_no_prr = 1;
19577 		else
19578 			rack->rack_no_prr = 0;
19579 		if (rack_gp_no_rec_chg)
19580 			rack->rc_gp_no_rec_chg = 1;
19581 		else
19582 			rack->rc_gp_no_rec_chg = 0;
19583 		if (rack_enable_mqueue_for_nonpaced || rack->r_use_cmp_ack) {
19584 			rack->r_mbuf_queue = 1;
19585 			if (TCPS_HAVEESTABLISHED(rack->rc_tp->t_state))
19586 				rack->rc_inp->inp_flags2 |= INP_MBUF_ACKCMP;
19587 			rack->rc_inp->inp_flags2 |= INP_SUPPORTS_MBUFQ;
19588 		} else {
19589 			rack->r_mbuf_queue = 0;
19590 			rack->rc_inp->inp_flags2 &= ~INP_SUPPORTS_MBUFQ;
19591 		}
19592 		if (rack_enable_shared_cwnd)
19593 			rack->rack_enable_scwnd = 1;
19594 		else
19595 			rack->rack_enable_scwnd = 0;
19596 		if (rack_do_dyn_mul) {
19597 			/* When dynamic adjustment is on CA needs to start at 100% */
19598 			rack->rc_gp_dyn_mul = 1;
19599 			if (rack_do_dyn_mul >= 100)
19600 				rack->r_ctl.rack_per_of_gp_ca = rack_do_dyn_mul;
19601 		} else {
19602 			rack->r_ctl.rack_per_of_gp_ca = rack_per_of_gp_ca;
19603 			rack->rc_gp_dyn_mul = 0;
19604 		}
19605 		rack->r_rr_config = 0;
19606 		rack->r_ctl.rc_no_push_at_mrtt = 0;
19607 		rack->rc_pace_to_cwnd = 0;
19608 		rack->rc_pace_fill_if_rttin_range = 0;
19609 		rack->rtt_limit_mul = 0;
19610 
19611 		if (rack_enable_hw_pacing)
19612 			rack->rack_hdw_pace_ena = 1;
19613 		else
19614 			rack->rack_hdw_pace_ena = 0;
19615 		if (rack_disable_prr)
19616 			rack->rack_no_prr = 1;
19617 		else
19618 			rack->rack_no_prr = 0;
19619 		if (rack_limits_scwnd)
19620 			rack->r_limit_scw  = 1;
19621 		else
19622 			rack->r_limit_scw  = 0;
19623 		err = 0;
19624 	}
19625 	return (err);
19626 }
19627 
19628 static int
19629 rack_add_deferred_option(struct tcp_rack *rack, int sopt_name, uint64_t loptval)
19630 {
19631 	struct deferred_opt_list *dol;
19632 
19633 	dol = malloc(sizeof(struct deferred_opt_list),
19634 		     M_TCPFSB, M_NOWAIT|M_ZERO);
19635 	if (dol == NULL) {
19636 		/*
19637 		 * No space yikes -- fail out..
19638 		 */
19639 		return (0);
19640 	}
19641 	dol->optname = sopt_name;
19642 	dol->optval = loptval;
19643 	TAILQ_INSERT_TAIL(&rack->r_ctl.opt_list, dol, next);
19644 	return (1);
19645 }
19646 
19647 static int
19648 rack_process_option(struct tcpcb *tp, struct tcp_rack *rack, int sopt_name,
19649 		    uint32_t optval, uint64_t loptval)
19650 {
19651 	struct epoch_tracker et;
19652 	struct sockopt sopt;
19653 	struct cc_newreno_opts opt;
19654 	uint64_t val;
19655 	int error = 0;
19656 	uint16_t ca, ss;
19657 
19658 	switch (sopt_name) {
19659 
19660 	case TCP_RACK_DSACK_OPT:
19661 		RACK_OPTS_INC(tcp_rack_dsack_opt);
19662 		if (optval & 0x1) {
19663 			rack->rc_rack_tmr_std_based = 1;
19664 		} else {
19665 			rack->rc_rack_tmr_std_based = 0;
19666 		}
19667 		if (optval & 0x2) {
19668 			rack->rc_rack_use_dsack = 1;
19669 		} else {
19670 			rack->rc_rack_use_dsack = 0;
19671 		}
19672 		rack_log_dsack_event(rack, 5, __LINE__, 0, 0);
19673 		break;
19674 	case TCP_RACK_PACING_BETA:
19675 		RACK_OPTS_INC(tcp_rack_beta);
19676 		if (strcmp(tp->cc_algo->name, CCALGONAME_NEWRENO) != 0) {
19677 			/* This only works for newreno. */
19678 			error = EINVAL;
19679 			break;
19680 		}
19681 		if (rack->rc_pacing_cc_set) {
19682 			/*
19683 			 * Set them into the real CC module
19684 			 * whats in the rack pcb is the old values
19685 			 * to be used on restoral/
19686 			 */
19687 			sopt.sopt_dir = SOPT_SET;
19688 			opt.name = CC_NEWRENO_BETA;
19689 			opt.val = optval;
19690 			if (CC_ALGO(tp)->ctl_output != NULL)
19691 				error = CC_ALGO(tp)->ctl_output(tp->ccv, &sopt, &opt);
19692 			else {
19693 				error = ENOENT;
19694 				break;
19695 			}
19696 		} else {
19697 			/*
19698 			 * Not pacing yet so set it into our local
19699 			 * rack pcb storage.
19700 			 */
19701 			rack->r_ctl.rc_saved_beta.beta = optval;
19702 		}
19703 		break;
19704 	case TCP_RACK_TIMER_SLOP:
19705 		RACK_OPTS_INC(tcp_rack_timer_slop);
19706 		rack->r_ctl.timer_slop = optval;
19707 		if (rack->rc_tp->t_srtt) {
19708 			/*
19709 			 * If we have an SRTT lets update t_rxtcur
19710 			 * to have the new slop.
19711 			 */
19712 			RACK_TCPT_RANGESET(tp->t_rxtcur, RACK_REXMTVAL(tp),
19713 					   rack_rto_min, rack_rto_max,
19714 					   rack->r_ctl.timer_slop);
19715 		}
19716 		break;
19717 	case TCP_RACK_PACING_BETA_ECN:
19718 		RACK_OPTS_INC(tcp_rack_beta_ecn);
19719 		if (strcmp(tp->cc_algo->name, CCALGONAME_NEWRENO) != 0) {
19720 			/* This only works for newreno. */
19721 			error = EINVAL;
19722 			break;
19723 		}
19724 		if (rack->rc_pacing_cc_set) {
19725 			/*
19726 			 * Set them into the real CC module
19727 			 * whats in the rack pcb is the old values
19728 			 * to be used on restoral/
19729 			 */
19730 			sopt.sopt_dir = SOPT_SET;
19731 			opt.name = CC_NEWRENO_BETA_ECN;
19732 			opt.val = optval;
19733 			if (CC_ALGO(tp)->ctl_output != NULL)
19734 				error = CC_ALGO(tp)->ctl_output(tp->ccv, &sopt, &opt);
19735 			else
19736 				error = ENOENT;
19737 		} else {
19738 			/*
19739 			 * Not pacing yet so set it into our local
19740 			 * rack pcb storage.
19741 			 */
19742 			rack->r_ctl.rc_saved_beta.beta_ecn = optval;
19743 			rack->r_ctl.rc_saved_beta.newreno_flags = CC_NEWRENO_BETA_ECN_ENABLED;
19744 		}
19745 		break;
19746 	case TCP_DEFER_OPTIONS:
19747 		RACK_OPTS_INC(tcp_defer_opt);
19748 		if (optval) {
19749 			if (rack->gp_ready) {
19750 				/* Too late */
19751 				error = EINVAL;
19752 				break;
19753 			}
19754 			rack->defer_options = 1;
19755 		} else
19756 			rack->defer_options = 0;
19757 		break;
19758 	case TCP_RACK_MEASURE_CNT:
19759 		RACK_OPTS_INC(tcp_rack_measure_cnt);
19760 		if (optval && (optval <= 0xff)) {
19761 			rack->r_ctl.req_measurements = optval;
19762 		} else
19763 			error = EINVAL;
19764 		break;
19765 	case TCP_REC_ABC_VAL:
19766 		RACK_OPTS_INC(tcp_rec_abc_val);
19767 		if (optval > 0)
19768 			rack->r_use_labc_for_rec = 1;
19769 		else
19770 			rack->r_use_labc_for_rec = 0;
19771 		break;
19772 	case TCP_RACK_ABC_VAL:
19773 		RACK_OPTS_INC(tcp_rack_abc_val);
19774 		if ((optval > 0) && (optval < 255))
19775 			rack->rc_labc = optval;
19776 		else
19777 			error = EINVAL;
19778 		break;
19779 	case TCP_HDWR_UP_ONLY:
19780 		RACK_OPTS_INC(tcp_pacing_up_only);
19781 		if (optval)
19782 			rack->r_up_only = 1;
19783 		else
19784 			rack->r_up_only = 0;
19785 		break;
19786 	case TCP_PACING_RATE_CAP:
19787 		RACK_OPTS_INC(tcp_pacing_rate_cap);
19788 		rack->r_ctl.bw_rate_cap = loptval;
19789 		break;
19790 	case TCP_RACK_PROFILE:
19791 		RACK_OPTS_INC(tcp_profile);
19792 		error = rack_set_profile(rack, optval);
19793 		break;
19794 	case TCP_USE_CMP_ACKS:
19795 		RACK_OPTS_INC(tcp_use_cmp_acks);
19796 		if ((optval == 0) && (rack->rc_inp->inp_flags2 & INP_MBUF_ACKCMP)) {
19797 			/* You can't turn it off once its on! */
19798 			error = EINVAL;
19799 		} else if ((optval == 1) && (rack->r_use_cmp_ack == 0)) {
19800 			rack->r_use_cmp_ack = 1;
19801 			rack->r_mbuf_queue = 1;
19802 			tp->t_inpcb->inp_flags2 |= INP_SUPPORTS_MBUFQ;
19803 		}
19804 		if (rack->r_use_cmp_ack && TCPS_HAVEESTABLISHED(tp->t_state))
19805 			rack->rc_inp->inp_flags2 |= INP_MBUF_ACKCMP;
19806 		break;
19807 	case TCP_SHARED_CWND_TIME_LIMIT:
19808 		RACK_OPTS_INC(tcp_lscwnd);
19809 		if (optval)
19810 			rack->r_limit_scw = 1;
19811 		else
19812 			rack->r_limit_scw = 0;
19813 		break;
19814  	case TCP_RACK_PACE_TO_FILL:
19815 		RACK_OPTS_INC(tcp_fillcw);
19816 		if (optval == 0)
19817 			rack->rc_pace_to_cwnd = 0;
19818 		else {
19819 			rack->rc_pace_to_cwnd = 1;
19820 			if (optval > 1)
19821 				rack->r_fill_less_agg = 1;
19822 		}
19823 		if ((optval >= rack_gp_rtt_maxmul) &&
19824 		    rack_gp_rtt_maxmul &&
19825 		    (optval < 0xf)) {
19826 			rack->rc_pace_fill_if_rttin_range = 1;
19827 			rack->rtt_limit_mul = optval;
19828 		} else {
19829 			rack->rc_pace_fill_if_rttin_range = 0;
19830 			rack->rtt_limit_mul = 0;
19831 		}
19832 		break;
19833 	case TCP_RACK_NO_PUSH_AT_MAX:
19834 		RACK_OPTS_INC(tcp_npush);
19835 		if (optval == 0)
19836 			rack->r_ctl.rc_no_push_at_mrtt = 0;
19837 		else if (optval < 0xff)
19838 			rack->r_ctl.rc_no_push_at_mrtt = optval;
19839 		else
19840 			error = EINVAL;
19841 		break;
19842 	case TCP_SHARED_CWND_ENABLE:
19843 		RACK_OPTS_INC(tcp_rack_scwnd);
19844 		if (optval == 0)
19845 			rack->rack_enable_scwnd = 0;
19846 		else
19847 			rack->rack_enable_scwnd = 1;
19848 		break;
19849 	case TCP_RACK_MBUF_QUEUE:
19850 		/* Now do we use the LRO mbuf-queue feature */
19851 		RACK_OPTS_INC(tcp_rack_mbufq);
19852 		if (optval || rack->r_use_cmp_ack)
19853 			rack->r_mbuf_queue = 1;
19854 		else
19855 			rack->r_mbuf_queue = 0;
19856 		if  (rack->r_mbuf_queue || rack->rc_always_pace || rack->r_use_cmp_ack)
19857 			tp->t_inpcb->inp_flags2 |= INP_SUPPORTS_MBUFQ;
19858 		else
19859 			tp->t_inpcb->inp_flags2 &= ~INP_SUPPORTS_MBUFQ;
19860 		break;
19861 	case TCP_RACK_NONRXT_CFG_RATE:
19862 		RACK_OPTS_INC(tcp_rack_cfg_rate);
19863 		if (optval == 0)
19864 			rack->rack_rec_nonrxt_use_cr = 0;
19865 		else
19866 			rack->rack_rec_nonrxt_use_cr = 1;
19867 		break;
19868 	case TCP_NO_PRR:
19869 		RACK_OPTS_INC(tcp_rack_noprr);
19870 		if (optval == 0)
19871 			rack->rack_no_prr = 0;
19872 		else if (optval == 1)
19873 			rack->rack_no_prr = 1;
19874 		else if (optval == 2)
19875 			rack->no_prr_addback = 1;
19876 		else
19877 			error = EINVAL;
19878 		break;
19879 	case TCP_TIMELY_DYN_ADJ:
19880 		RACK_OPTS_INC(tcp_timely_dyn);
19881 		if (optval == 0)
19882 			rack->rc_gp_dyn_mul = 0;
19883 		else {
19884 			rack->rc_gp_dyn_mul = 1;
19885 			if (optval >= 100) {
19886 				/*
19887 				 * If the user sets something 100 or more
19888 				 * its the gp_ca value.
19889 				 */
19890 				rack->r_ctl.rack_per_of_gp_ca  = optval;
19891 			}
19892 		}
19893 		break;
19894 	case TCP_RACK_DO_DETECTION:
19895 		RACK_OPTS_INC(tcp_rack_do_detection);
19896 		if (optval == 0)
19897 			rack->do_detection = 0;
19898 		else
19899 			rack->do_detection = 1;
19900 		break;
19901 	case TCP_RACK_TLP_USE:
19902 		if ((optval < TLP_USE_ID) || (optval > TLP_USE_TWO_TWO)) {
19903 			error = EINVAL;
19904 			break;
19905 		}
19906 		RACK_OPTS_INC(tcp_tlp_use);
19907 		rack->rack_tlp_threshold_use = optval;
19908 		break;
19909 	case TCP_RACK_TLP_REDUCE:
19910 		/* RACK TLP cwnd reduction (bool) */
19911 		RACK_OPTS_INC(tcp_rack_tlp_reduce);
19912 		rack->r_ctl.rc_tlp_cwnd_reduce = optval;
19913 		break;
19914 	/*  Pacing related ones */
19915 	case TCP_RACK_PACE_ALWAYS:
19916 		/*
19917 		 * zero is old rack method, 1 is new
19918 		 * method using a pacing rate.
19919 		 */
19920 		RACK_OPTS_INC(tcp_rack_pace_always);
19921 		if (optval > 0) {
19922 			if (rack->rc_always_pace) {
19923 				error = EALREADY;
19924 				break;
19925 			} else if (tcp_can_enable_pacing()) {
19926 				rack->rc_always_pace = 1;
19927 				if (rack->use_fixed_rate || rack->gp_ready)
19928 					rack_set_cc_pacing(rack);
19929 			}
19930 			else {
19931 				error = ENOSPC;
19932 				break;
19933 			}
19934 		} else {
19935 			if (rack->rc_always_pace) {
19936 				tcp_decrement_paced_conn();
19937 				rack->rc_always_pace = 0;
19938 				rack_undo_cc_pacing(rack);
19939 			}
19940 		}
19941 		if  (rack->r_mbuf_queue || rack->rc_always_pace || rack->r_use_cmp_ack)
19942 			tp->t_inpcb->inp_flags2 |= INP_SUPPORTS_MBUFQ;
19943 		else
19944 			tp->t_inpcb->inp_flags2 &= ~INP_SUPPORTS_MBUFQ;
19945 		/* A rate may be set irate or other, if so set seg size */
19946 		rack_update_seg(rack);
19947 		break;
19948 	case TCP_BBR_RACK_INIT_RATE:
19949 		RACK_OPTS_INC(tcp_initial_rate);
19950 		val = optval;
19951 		/* Change from kbits per second to bytes per second */
19952 		val *= 1000;
19953 		val /= 8;
19954 		rack->r_ctl.init_rate = val;
19955 		if (rack->rc_init_win != rack_default_init_window) {
19956 			uint32_t win, snt;
19957 
19958 			/*
19959 			 * Options don't always get applied
19960 			 * in the order you think. So in order
19961 			 * to assure we update a cwnd we need
19962 			 * to check and see if we are still
19963 			 * where we should raise the cwnd.
19964 			 */
19965 			win = rc_init_window(rack);
19966 			if (SEQ_GT(tp->snd_max, tp->iss))
19967 				snt = tp->snd_max - tp->iss;
19968 			else
19969 				snt = 0;
19970 			if ((snt < win) &&
19971 			    (tp->snd_cwnd < win))
19972 				tp->snd_cwnd = win;
19973 		}
19974 		if (rack->rc_always_pace)
19975 			rack_update_seg(rack);
19976 		break;
19977 	case TCP_BBR_IWINTSO:
19978 		RACK_OPTS_INC(tcp_initial_win);
19979 		if (optval && (optval <= 0xff)) {
19980 			uint32_t win, snt;
19981 
19982 			rack->rc_init_win = optval;
19983 			win = rc_init_window(rack);
19984 			if (SEQ_GT(tp->snd_max, tp->iss))
19985 				snt = tp->snd_max - tp->iss;
19986 			else
19987 				snt = 0;
19988 			if ((snt < win) &&
19989 			    (tp->t_srtt |
19990 #ifdef NETFLIX_PEAKRATE
19991 			     tp->t_maxpeakrate |
19992 #endif
19993 			     rack->r_ctl.init_rate)) {
19994 				/*
19995 				 * We are not past the initial window
19996 				 * and we have some bases for pacing,
19997 				 * so we need to possibly adjust up
19998 				 * the cwnd. Note even if we don't set
19999 				 * the cwnd, its still ok to raise the rc_init_win
20000 				 * which can be used coming out of idle when we
20001 				 * would have a rate.
20002 				 */
20003 				if (tp->snd_cwnd < win)
20004 					tp->snd_cwnd = win;
20005 			}
20006 			if (rack->rc_always_pace)
20007 				rack_update_seg(rack);
20008 		} else
20009 			error = EINVAL;
20010 		break;
20011 	case TCP_RACK_FORCE_MSEG:
20012 		RACK_OPTS_INC(tcp_rack_force_max_seg);
20013 		if (optval)
20014 			rack->rc_force_max_seg = 1;
20015 		else
20016 			rack->rc_force_max_seg = 0;
20017 		break;
20018 	case TCP_RACK_PACE_MAX_SEG:
20019 		/* Max segments size in a pace in bytes */
20020 		RACK_OPTS_INC(tcp_rack_max_seg);
20021 		rack->rc_user_set_max_segs = optval;
20022 		rack_set_pace_segments(tp, rack, __LINE__, NULL);
20023 		break;
20024 	case TCP_RACK_PACE_RATE_REC:
20025 		/* Set the fixed pacing rate in Bytes per second ca */
20026 		RACK_OPTS_INC(tcp_rack_pace_rate_rec);
20027 		rack->r_ctl.rc_fixed_pacing_rate_rec = optval;
20028 		if (rack->r_ctl.rc_fixed_pacing_rate_ca == 0)
20029 			rack->r_ctl.rc_fixed_pacing_rate_ca = optval;
20030 		if (rack->r_ctl.rc_fixed_pacing_rate_ss == 0)
20031 			rack->r_ctl.rc_fixed_pacing_rate_ss = optval;
20032 		rack->use_fixed_rate = 1;
20033 		if (rack->rc_always_pace)
20034 			rack_set_cc_pacing(rack);
20035 		rack_log_pacing_delay_calc(rack,
20036 					   rack->r_ctl.rc_fixed_pacing_rate_ss,
20037 					   rack->r_ctl.rc_fixed_pacing_rate_ca,
20038 					   rack->r_ctl.rc_fixed_pacing_rate_rec, 0, 0, 8,
20039 					   __LINE__, NULL,0);
20040 		break;
20041 
20042 	case TCP_RACK_PACE_RATE_SS:
20043 		/* Set the fixed pacing rate in Bytes per second ca */
20044 		RACK_OPTS_INC(tcp_rack_pace_rate_ss);
20045 		rack->r_ctl.rc_fixed_pacing_rate_ss = optval;
20046 		if (rack->r_ctl.rc_fixed_pacing_rate_ca == 0)
20047 			rack->r_ctl.rc_fixed_pacing_rate_ca = optval;
20048 		if (rack->r_ctl.rc_fixed_pacing_rate_rec == 0)
20049 			rack->r_ctl.rc_fixed_pacing_rate_rec = optval;
20050 		rack->use_fixed_rate = 1;
20051 		if (rack->rc_always_pace)
20052 			rack_set_cc_pacing(rack);
20053 		rack_log_pacing_delay_calc(rack,
20054 					   rack->r_ctl.rc_fixed_pacing_rate_ss,
20055 					   rack->r_ctl.rc_fixed_pacing_rate_ca,
20056 					   rack->r_ctl.rc_fixed_pacing_rate_rec, 0, 0, 8,
20057 					   __LINE__, NULL, 0);
20058 		break;
20059 
20060 	case TCP_RACK_PACE_RATE_CA:
20061 		/* Set the fixed pacing rate in Bytes per second ca */
20062 		RACK_OPTS_INC(tcp_rack_pace_rate_ca);
20063 		rack->r_ctl.rc_fixed_pacing_rate_ca = optval;
20064 		if (rack->r_ctl.rc_fixed_pacing_rate_ss == 0)
20065 			rack->r_ctl.rc_fixed_pacing_rate_ss = optval;
20066 		if (rack->r_ctl.rc_fixed_pacing_rate_rec == 0)
20067 			rack->r_ctl.rc_fixed_pacing_rate_rec = optval;
20068 		rack->use_fixed_rate = 1;
20069 		if (rack->rc_always_pace)
20070 			rack_set_cc_pacing(rack);
20071 		rack_log_pacing_delay_calc(rack,
20072 					   rack->r_ctl.rc_fixed_pacing_rate_ss,
20073 					   rack->r_ctl.rc_fixed_pacing_rate_ca,
20074 					   rack->r_ctl.rc_fixed_pacing_rate_rec, 0, 0, 8,
20075 					   __LINE__, NULL, 0);
20076 		break;
20077 	case TCP_RACK_GP_INCREASE_REC:
20078 		RACK_OPTS_INC(tcp_gp_inc_rec);
20079 		rack->r_ctl.rack_per_of_gp_rec = optval;
20080 		rack_log_pacing_delay_calc(rack,
20081 					   rack->r_ctl.rack_per_of_gp_ss,
20082 					   rack->r_ctl.rack_per_of_gp_ca,
20083 					   rack->r_ctl.rack_per_of_gp_rec, 0, 0, 1,
20084 					   __LINE__, NULL, 0);
20085 		break;
20086 	case TCP_RACK_GP_INCREASE_CA:
20087 		RACK_OPTS_INC(tcp_gp_inc_ca);
20088 		ca = optval;
20089 		if (ca < 100) {
20090 			/*
20091 			 * We don't allow any reduction
20092 			 * over the GP b/w.
20093 			 */
20094 			error = EINVAL;
20095 			break;
20096 		}
20097 		rack->r_ctl.rack_per_of_gp_ca = ca;
20098 		rack_log_pacing_delay_calc(rack,
20099 					   rack->r_ctl.rack_per_of_gp_ss,
20100 					   rack->r_ctl.rack_per_of_gp_ca,
20101 					   rack->r_ctl.rack_per_of_gp_rec, 0, 0, 1,
20102 					   __LINE__, NULL, 0);
20103 		break;
20104 	case TCP_RACK_GP_INCREASE_SS:
20105 		RACK_OPTS_INC(tcp_gp_inc_ss);
20106 		ss = optval;
20107 		if (ss < 100) {
20108 			/*
20109 			 * We don't allow any reduction
20110 			 * over the GP b/w.
20111 			 */
20112 			error = EINVAL;
20113 			break;
20114 		}
20115 		rack->r_ctl.rack_per_of_gp_ss = ss;
20116 		rack_log_pacing_delay_calc(rack,
20117 					   rack->r_ctl.rack_per_of_gp_ss,
20118 					   rack->r_ctl.rack_per_of_gp_ca,
20119 					   rack->r_ctl.rack_per_of_gp_rec, 0, 0, 1,
20120 					   __LINE__, NULL, 0);
20121 		break;
20122 	case TCP_RACK_RR_CONF:
20123 		RACK_OPTS_INC(tcp_rack_rrr_no_conf_rate);
20124 		if (optval && optval <= 3)
20125 			rack->r_rr_config = optval;
20126 		else
20127 			rack->r_rr_config = 0;
20128 		break;
20129 	case TCP_HDWR_RATE_CAP:
20130 		RACK_OPTS_INC(tcp_hdwr_rate_cap);
20131 		if (optval) {
20132 			if (rack->r_rack_hw_rate_caps == 0)
20133 				rack->r_rack_hw_rate_caps = 1;
20134 			else
20135 				error = EALREADY;
20136 		} else {
20137 			rack->r_rack_hw_rate_caps = 0;
20138 		}
20139 		break;
20140 	case TCP_BBR_HDWR_PACE:
20141 		RACK_OPTS_INC(tcp_hdwr_pacing);
20142 		if (optval){
20143 			if (rack->rack_hdrw_pacing == 0) {
20144 				rack->rack_hdw_pace_ena = 1;
20145 				rack->rack_attempt_hdwr_pace = 0;
20146 			} else
20147 				error = EALREADY;
20148 		} else {
20149 			rack->rack_hdw_pace_ena = 0;
20150 #ifdef RATELIMIT
20151 			if (rack->r_ctl.crte != NULL) {
20152 				rack->rack_hdrw_pacing = 0;
20153 				rack->rack_attempt_hdwr_pace = 0;
20154 				tcp_rel_pacing_rate(rack->r_ctl.crte, tp);
20155 				rack->r_ctl.crte = NULL;
20156 			}
20157 #endif
20158 		}
20159 		break;
20160 	/*  End Pacing related ones */
20161 	case TCP_RACK_PRR_SENDALOT:
20162 		/* Allow PRR to send more than one seg */
20163 		RACK_OPTS_INC(tcp_rack_prr_sendalot);
20164 		rack->r_ctl.rc_prr_sendalot = optval;
20165 		break;
20166 	case TCP_RACK_MIN_TO:
20167 		/* Minimum time between rack t-o's in ms */
20168 		RACK_OPTS_INC(tcp_rack_min_to);
20169 		rack->r_ctl.rc_min_to = optval;
20170 		break;
20171 	case TCP_RACK_EARLY_SEG:
20172 		/* If early recovery max segments */
20173 		RACK_OPTS_INC(tcp_rack_early_seg);
20174 		rack->r_ctl.rc_early_recovery_segs = optval;
20175 		break;
20176 	case TCP_RACK_ENABLE_HYSTART:
20177 	{
20178 		if (optval) {
20179 			tp->ccv->flags |= CCF_HYSTART_ALLOWED;
20180 			if (rack_do_hystart > RACK_HYSTART_ON)
20181 				tp->ccv->flags |= CCF_HYSTART_CAN_SH_CWND;
20182 			if (rack_do_hystart > RACK_HYSTART_ON_W_SC)
20183 				tp->ccv->flags |= CCF_HYSTART_CONS_SSTH;
20184 		} else {
20185 			tp->ccv->flags &= ~(CCF_HYSTART_ALLOWED|CCF_HYSTART_CAN_SH_CWND|CCF_HYSTART_CONS_SSTH);
20186 		}
20187 	}
20188 	break;
20189 	case TCP_RACK_REORD_THRESH:
20190 		/* RACK reorder threshold (shift amount) */
20191 		RACK_OPTS_INC(tcp_rack_reord_thresh);
20192 		if ((optval > 0) && (optval < 31))
20193 			rack->r_ctl.rc_reorder_shift = optval;
20194 		else
20195 			error = EINVAL;
20196 		break;
20197 	case TCP_RACK_REORD_FADE:
20198 		/* Does reordering fade after ms time */
20199 		RACK_OPTS_INC(tcp_rack_reord_fade);
20200 		rack->r_ctl.rc_reorder_fade = optval;
20201 		break;
20202 	case TCP_RACK_TLP_THRESH:
20203 		/* RACK TLP theshold i.e. srtt+(srtt/N) */
20204 		RACK_OPTS_INC(tcp_rack_tlp_thresh);
20205 		if (optval)
20206 			rack->r_ctl.rc_tlp_threshold = optval;
20207 		else
20208 			error = EINVAL;
20209 		break;
20210 	case TCP_BBR_USE_RACK_RR:
20211 		RACK_OPTS_INC(tcp_rack_rr);
20212 		if (optval)
20213 			rack->use_rack_rr = 1;
20214 		else
20215 			rack->use_rack_rr = 0;
20216 		break;
20217 	case TCP_FAST_RSM_HACK:
20218 		RACK_OPTS_INC(tcp_rack_fastrsm_hack);
20219 		if (optval)
20220 			rack->fast_rsm_hack = 1;
20221 		else
20222 			rack->fast_rsm_hack = 0;
20223 		break;
20224 	case TCP_RACK_PKT_DELAY:
20225 		/* RACK added ms i.e. rack-rtt + reord + N */
20226 		RACK_OPTS_INC(tcp_rack_pkt_delay);
20227 		rack->r_ctl.rc_pkt_delay = optval;
20228 		break;
20229 	case TCP_DELACK:
20230 		RACK_OPTS_INC(tcp_rack_delayed_ack);
20231 		if (optval == 0)
20232 			tp->t_delayed_ack = 0;
20233 		else
20234 			tp->t_delayed_ack = 1;
20235 		if (tp->t_flags & TF_DELACK) {
20236 			tp->t_flags &= ~TF_DELACK;
20237 			tp->t_flags |= TF_ACKNOW;
20238 			NET_EPOCH_ENTER(et);
20239 			rack_output(tp);
20240 			NET_EPOCH_EXIT(et);
20241 		}
20242 		break;
20243 
20244 	case TCP_BBR_RACK_RTT_USE:
20245 		RACK_OPTS_INC(tcp_rack_rtt_use);
20246 		if ((optval != USE_RTT_HIGH) &&
20247 		    (optval != USE_RTT_LOW) &&
20248 		    (optval != USE_RTT_AVG))
20249 			error = EINVAL;
20250 		else
20251 			rack->r_ctl.rc_rate_sample_method = optval;
20252 		break;
20253 	case TCP_DATA_AFTER_CLOSE:
20254 		RACK_OPTS_INC(tcp_data_after_close);
20255 		if (optval)
20256 			rack->rc_allow_data_af_clo = 1;
20257 		else
20258 			rack->rc_allow_data_af_clo = 0;
20259 		break;
20260 	default:
20261 		break;
20262 	}
20263 #ifdef NETFLIX_STATS
20264 	tcp_log_socket_option(tp, sopt_name, optval, error);
20265 #endif
20266 	return (error);
20267 }
20268 
20269 
20270 static void
20271 rack_apply_deferred_options(struct tcp_rack *rack)
20272 {
20273 	struct deferred_opt_list *dol, *sdol;
20274 	uint32_t s_optval;
20275 
20276 	TAILQ_FOREACH_SAFE(dol, &rack->r_ctl.opt_list, next, sdol) {
20277 		TAILQ_REMOVE(&rack->r_ctl.opt_list, dol, next);
20278 		/* Disadvantage of deferal is you loose the error return */
20279 		s_optval = (uint32_t)dol->optval;
20280 		(void)rack_process_option(rack->rc_tp, rack, dol->optname, s_optval, dol->optval);
20281 		free(dol, M_TCPDO);
20282 	}
20283 }
20284 
20285 static void
20286 rack_hw_tls_change(struct tcpcb *tp, int chg)
20287 {
20288 	/*
20289 	 * HW tls state has changed.. fix all
20290 	 * rsm's in flight.
20291 	 */
20292 	struct tcp_rack *rack;
20293 	struct rack_sendmap *rsm;
20294 
20295 	rack = (struct tcp_rack *)tp->t_fb_ptr;
20296 	RB_FOREACH(rsm, rack_rb_tree_head, &rack->r_ctl.rc_mtree) {
20297 		if (chg)
20298 			rsm->r_hw_tls = 1;
20299 		else
20300 			rsm->r_hw_tls = 0;
20301 	}
20302 	if (chg)
20303 		rack->r_ctl.fsb.hw_tls = 1;
20304 	else
20305 		rack->r_ctl.fsb.hw_tls = 0;
20306 }
20307 
20308 static int
20309 rack_pru_options(struct tcpcb *tp, int flags)
20310 {
20311 	if (flags & PRUS_OOB)
20312 		return (EOPNOTSUPP);
20313 	return (0);
20314 }
20315 
20316 static struct tcp_function_block __tcp_rack = {
20317 	.tfb_tcp_block_name = __XSTRING(STACKNAME),
20318 	.tfb_tcp_output = rack_output,
20319 	.tfb_do_queued_segments = ctf_do_queued_segments,
20320 	.tfb_do_segment_nounlock = rack_do_segment_nounlock,
20321 	.tfb_tcp_do_segment = rack_do_segment,
20322 	.tfb_tcp_ctloutput = rack_ctloutput,
20323 	.tfb_tcp_fb_init = rack_init,
20324 	.tfb_tcp_fb_fini = rack_fini,
20325 	.tfb_tcp_timer_stop_all = rack_stopall,
20326 	.tfb_tcp_timer_activate = rack_timer_activate,
20327 	.tfb_tcp_timer_active = rack_timer_active,
20328 	.tfb_tcp_timer_stop = rack_timer_stop,
20329 	.tfb_tcp_rexmit_tmr = rack_remxt_tmr,
20330 	.tfb_tcp_handoff_ok = rack_handoff_ok,
20331 	.tfb_tcp_mtu_chg = rack_mtu_change,
20332 	.tfb_pru_options = rack_pru_options,
20333 	.tfb_hwtls_change = rack_hw_tls_change,
20334 	.tfb_compute_pipe = rack_compute_pipe,
20335 	.tfb_flags = TCP_FUNC_OUTPUT_CANDROP,
20336 };
20337 
20338 /*
20339  * rack_ctloutput() must drop the inpcb lock before performing copyin on
20340  * socket option arguments.  When it re-acquires the lock after the copy, it
20341  * has to revalidate that the connection is still valid for the socket
20342  * option.
20343  */
20344 static int
20345 rack_set_sockopt(struct inpcb *inp, struct sockopt *sopt)
20346 {
20347 #ifdef INET6
20348 	struct ip6_hdr *ip6;
20349 #endif
20350 #ifdef INET
20351 	struct ip *ip;
20352 #endif
20353 	struct tcpcb *tp;
20354 	struct tcp_rack *rack;
20355 	uint64_t loptval;
20356 	int32_t error = 0, optval;
20357 
20358 	tp = intotcpcb(inp);
20359 	rack = (struct tcp_rack *)tp->t_fb_ptr;
20360 	if (rack == NULL) {
20361 		INP_WUNLOCK(inp);
20362 		return (EINVAL);
20363 	}
20364 #ifdef INET6
20365 	ip6 = (struct ip6_hdr *)rack->r_ctl.fsb.tcp_ip_hdr;
20366 #endif
20367 #ifdef INET
20368 	ip = (struct ip *)rack->r_ctl.fsb.tcp_ip_hdr;
20369 #endif
20370 
20371 	switch (sopt->sopt_level) {
20372 #ifdef INET6
20373 	case IPPROTO_IPV6:
20374 		MPASS(inp->inp_vflag & INP_IPV6PROTO);
20375 		switch (sopt->sopt_name) {
20376 		case IPV6_USE_MIN_MTU:
20377 			tcp6_use_min_mtu(tp);
20378 			break;
20379 		case IPV6_TCLASS:
20380 			/*
20381 			 * The DSCP codepoint has changed, update the fsb.
20382 			 */
20383 			ip6->ip6_flow = (ip6->ip6_flow & ~IPV6_FLOWINFO_MASK) |
20384 			    (rack->rc_inp->inp_flow & IPV6_FLOWINFO_MASK);
20385 			break;
20386 		}
20387 		INP_WUNLOCK(inp);
20388 		return (0);
20389 #endif
20390 #ifdef INET
20391 	case IPPROTO_IP:
20392 		switch (sopt->sopt_name) {
20393 		case IP_TOS:
20394 			/*
20395 			 * The DSCP codepoint has changed, update the fsb.
20396 			 */
20397 			ip->ip_tos = rack->rc_inp->inp_ip_tos;
20398 			break;
20399 		case IP_TTL:
20400 			/*
20401 			 * The TTL has changed, update the fsb.
20402 			 */
20403 			ip->ip_ttl = rack->rc_inp->inp_ip_ttl;
20404 			break;
20405 		}
20406 		INP_WUNLOCK(inp);
20407 		return (0);
20408 #endif
20409 	}
20410 
20411 	switch (sopt->sopt_name) {
20412 	case TCP_RACK_TLP_REDUCE:		/*  URL:tlp_reduce */
20413 	/*  Pacing related ones */
20414 	case TCP_RACK_PACE_ALWAYS:		/*  URL:pace_always */
20415 	case TCP_BBR_RACK_INIT_RATE:		/*  URL:irate */
20416 	case TCP_BBR_IWINTSO:			/*  URL:tso_iwin */
20417 	case TCP_RACK_PACE_MAX_SEG:		/*  URL:pace_max_seg */
20418 	case TCP_RACK_FORCE_MSEG:		/*  URL:force_max_seg */
20419 	case TCP_RACK_PACE_RATE_CA:		/*  URL:pr_ca */
20420 	case TCP_RACK_PACE_RATE_SS:		/*  URL:pr_ss*/
20421 	case TCP_RACK_PACE_RATE_REC:		/*  URL:pr_rec */
20422 	case TCP_RACK_GP_INCREASE_CA:		/*  URL:gp_inc_ca */
20423 	case TCP_RACK_GP_INCREASE_SS:		/*  URL:gp_inc_ss */
20424 	case TCP_RACK_GP_INCREASE_REC:		/*  URL:gp_inc_rec */
20425 	case TCP_RACK_RR_CONF:			/*  URL:rrr_conf */
20426 	case TCP_BBR_HDWR_PACE:			/*  URL:hdwrpace */
20427 	case TCP_HDWR_RATE_CAP:			/*  URL:hdwrcap boolean */
20428 	case TCP_PACING_RATE_CAP:		/*  URL:cap  -- used by side-channel */
20429 	case TCP_HDWR_UP_ONLY:			/*  URL:uponly -- hardware pacing  boolean */
20430        /* End pacing related */
20431 	case TCP_FAST_RSM_HACK:			/*  URL:frsm_hack */
20432 	case TCP_DELACK:			/*  URL:delack (in base TCP i.e. tcp_hints along with cc etc ) */
20433 	case TCP_RACK_PRR_SENDALOT:		/*  URL:prr_sendalot */
20434 	case TCP_RACK_MIN_TO:			/*  URL:min_to */
20435 	case TCP_RACK_EARLY_SEG:		/*  URL:early_seg */
20436 	case TCP_RACK_REORD_THRESH:		/*  URL:reord_thresh */
20437 	case TCP_RACK_REORD_FADE:		/*  URL:reord_fade */
20438 	case TCP_RACK_TLP_THRESH:		/*  URL:tlp_thresh */
20439 	case TCP_RACK_PKT_DELAY:		/*  URL:pkt_delay */
20440 	case TCP_RACK_TLP_USE:			/*  URL:tlp_use */
20441 	case TCP_BBR_RACK_RTT_USE:		/*  URL:rttuse */
20442 	case TCP_BBR_USE_RACK_RR:		/*  URL:rackrr */
20443 	case TCP_RACK_DO_DETECTION:		/*  URL:detect */
20444 	case TCP_NO_PRR:			/*  URL:noprr */
20445 	case TCP_TIMELY_DYN_ADJ:      		/*  URL:dynamic */
20446 	case TCP_DATA_AFTER_CLOSE:		/*  no URL */
20447 	case TCP_RACK_NONRXT_CFG_RATE:		/*  URL:nonrxtcr */
20448 	case TCP_SHARED_CWND_ENABLE:		/*  URL:scwnd */
20449 	case TCP_RACK_MBUF_QUEUE:		/*  URL:mqueue */
20450 	case TCP_RACK_NO_PUSH_AT_MAX:		/*  URL:npush */
20451 	case TCP_RACK_PACE_TO_FILL:		/*  URL:fillcw */
20452 	case TCP_SHARED_CWND_TIME_LIMIT:	/*  URL:lscwnd */
20453 	case TCP_RACK_PROFILE:			/*  URL:profile */
20454 	case TCP_USE_CMP_ACKS:			/*  URL:cmpack */
20455 	case TCP_RACK_ABC_VAL:			/*  URL:labc */
20456 	case TCP_REC_ABC_VAL:			/*  URL:reclabc */
20457 	case TCP_RACK_MEASURE_CNT:		/*  URL:measurecnt */
20458 	case TCP_DEFER_OPTIONS:			/*  URL:defer */
20459 	case TCP_RACK_DSACK_OPT:		/*  URL:dsack */
20460 	case TCP_RACK_PACING_BETA:		/*  URL:pacing_beta */
20461 	case TCP_RACK_PACING_BETA_ECN:		/*  URL:pacing_beta_ecn */
20462 	case TCP_RACK_TIMER_SLOP:		/*  URL:timer_slop */
20463 	case TCP_RACK_ENABLE_HYSTART:		/*  URL:hystart */
20464 		break;
20465 	default:
20466 		/* Filter off all unknown options to the base stack */
20467 		return (tcp_default_ctloutput(inp, sopt));
20468 		break;
20469 	}
20470 	INP_WUNLOCK(inp);
20471 	if (sopt->sopt_name == TCP_PACING_RATE_CAP) {
20472 		error = sooptcopyin(sopt, &loptval, sizeof(loptval), sizeof(loptval));
20473 		/*
20474 		 * We truncate it down to 32 bits for the socket-option trace this
20475 		 * means rates > 34Gbps won't show right, but thats probably ok.
20476 		 */
20477 		optval = (uint32_t)loptval;
20478 	} else {
20479 		error = sooptcopyin(sopt, &optval, sizeof(optval), sizeof(optval));
20480 		/* Save it in 64 bit form too */
20481 		loptval = optval;
20482 	}
20483 	if (error)
20484 		return (error);
20485 	INP_WLOCK(inp);
20486 	if (inp->inp_flags & (INP_TIMEWAIT | INP_DROPPED)) {
20487 		INP_WUNLOCK(inp);
20488 		return (ECONNRESET);
20489 	}
20490 	if (tp->t_fb != &__tcp_rack) {
20491 		INP_WUNLOCK(inp);
20492 		return (ENOPROTOOPT);
20493 	}
20494 	if (rack->defer_options && (rack->gp_ready == 0) &&
20495 	    (sopt->sopt_name != TCP_DEFER_OPTIONS) &&
20496 	    (sopt->sopt_name != TCP_RACK_PACING_BETA) &&
20497 	    (sopt->sopt_name != TCP_RACK_PACING_BETA_ECN) &&
20498 	    (sopt->sopt_name != TCP_RACK_MEASURE_CNT)) {
20499 		/* Options are beind deferred */
20500 		if (rack_add_deferred_option(rack, sopt->sopt_name, loptval)) {
20501 			INP_WUNLOCK(inp);
20502 			return (0);
20503 		} else {
20504 			/* No memory to defer, fail */
20505 			INP_WUNLOCK(inp);
20506 			return (ENOMEM);
20507 		}
20508 	}
20509 	error = rack_process_option(tp, rack, sopt->sopt_name, optval, loptval);
20510 	INP_WUNLOCK(inp);
20511 	return (error);
20512 }
20513 
20514 static void
20515 rack_fill_info(struct tcpcb *tp, struct tcp_info *ti)
20516 {
20517 
20518 	INP_WLOCK_ASSERT(tp->t_inpcb);
20519 	bzero(ti, sizeof(*ti));
20520 
20521 	ti->tcpi_state = tp->t_state;
20522 	if ((tp->t_flags & TF_REQ_TSTMP) && (tp->t_flags & TF_RCVD_TSTMP))
20523 		ti->tcpi_options |= TCPI_OPT_TIMESTAMPS;
20524 	if (tp->t_flags & TF_SACK_PERMIT)
20525 		ti->tcpi_options |= TCPI_OPT_SACK;
20526 	if ((tp->t_flags & TF_REQ_SCALE) && (tp->t_flags & TF_RCVD_SCALE)) {
20527 		ti->tcpi_options |= TCPI_OPT_WSCALE;
20528 		ti->tcpi_snd_wscale = tp->snd_scale;
20529 		ti->tcpi_rcv_wscale = tp->rcv_scale;
20530 	}
20531 	if (tp->t_flags2 & (TF2_ECN_PERMIT | TF2_ACE_PERMIT))
20532 		ti->tcpi_options |= TCPI_OPT_ECN;
20533 	if (tp->t_flags & TF_FASTOPEN)
20534 		ti->tcpi_options |= TCPI_OPT_TFO;
20535 	/* still kept in ticks is t_rcvtime */
20536 	ti->tcpi_last_data_recv = ((uint32_t)ticks - tp->t_rcvtime) * tick;
20537 	/* Since we hold everything in precise useconds this is easy */
20538 	ti->tcpi_rtt = tp->t_srtt;
20539 	ti->tcpi_rttvar = tp->t_rttvar;
20540 	ti->tcpi_rto = tp->t_rxtcur;
20541 	ti->tcpi_snd_ssthresh = tp->snd_ssthresh;
20542 	ti->tcpi_snd_cwnd = tp->snd_cwnd;
20543 	/*
20544 	 * FreeBSD-specific extension fields for tcp_info.
20545 	 */
20546 	ti->tcpi_rcv_space = tp->rcv_wnd;
20547 	ti->tcpi_rcv_nxt = tp->rcv_nxt;
20548 	ti->tcpi_snd_wnd = tp->snd_wnd;
20549 	ti->tcpi_snd_bwnd = 0;		/* Unused, kept for compat. */
20550 	ti->tcpi_snd_nxt = tp->snd_nxt;
20551 	ti->tcpi_snd_mss = tp->t_maxseg;
20552 	ti->tcpi_rcv_mss = tp->t_maxseg;
20553 	ti->tcpi_snd_rexmitpack = tp->t_sndrexmitpack;
20554 	ti->tcpi_rcv_ooopack = tp->t_rcvoopack;
20555 	ti->tcpi_snd_zerowin = tp->t_sndzerowin;
20556 #ifdef NETFLIX_STATS
20557 	ti->tcpi_total_tlp = tp->t_sndtlppack;
20558 	ti->tcpi_total_tlp_bytes = tp->t_sndtlpbyte;
20559 	memcpy(&ti->tcpi_rxsyninfo, &tp->t_rxsyninfo, sizeof(struct tcpsyninfo));
20560 #endif
20561 #ifdef TCP_OFFLOAD
20562 	if (tp->t_flags & TF_TOE) {
20563 		ti->tcpi_options |= TCPI_OPT_TOE;
20564 		tcp_offload_tcp_info(tp, ti);
20565 	}
20566 #endif
20567 }
20568 
20569 static int
20570 rack_get_sockopt(struct inpcb *inp, struct sockopt *sopt)
20571 {
20572 	struct tcpcb *tp;
20573 	struct tcp_rack *rack;
20574 	int32_t error, optval;
20575 	uint64_t val, loptval;
20576 	struct	tcp_info ti;
20577 	/*
20578 	 * Because all our options are either boolean or an int, we can just
20579 	 * pull everything into optval and then unlock and copy. If we ever
20580 	 * add a option that is not a int, then this will have quite an
20581 	 * impact to this routine.
20582 	 */
20583 	error = 0;
20584 	tp = intotcpcb(inp);
20585 	rack = (struct tcp_rack *)tp->t_fb_ptr;
20586 	if (rack == NULL) {
20587 		INP_WUNLOCK(inp);
20588 		return (EINVAL);
20589 	}
20590 	switch (sopt->sopt_name) {
20591 	case TCP_INFO:
20592 		/* First get the info filled */
20593 		rack_fill_info(tp, &ti);
20594 		/* Fix up the rtt related fields if needed */
20595 		INP_WUNLOCK(inp);
20596 		error = sooptcopyout(sopt, &ti, sizeof ti);
20597 		return (error);
20598 	/*
20599 	 * Beta is the congestion control value for NewReno that influences how
20600 	 * much of a backoff happens when loss is detected. It is normally set
20601 	 * to 50 for 50% i.e. the cwnd is reduced to 50% of its previous value
20602 	 * when you exit recovery.
20603 	 */
20604 	case TCP_RACK_PACING_BETA:
20605 		if (strcmp(tp->cc_algo->name, CCALGONAME_NEWRENO) != 0)
20606 			error = EINVAL;
20607 		else if (rack->rc_pacing_cc_set == 0)
20608 			optval = rack->r_ctl.rc_saved_beta.beta;
20609 		else {
20610 			/*
20611 			 * Reach out into the CC data and report back what
20612 			 * I have previously set. Yeah it looks hackish but
20613 			 * we don't want to report the saved values.
20614 			 */
20615 			if (tp->ccv->cc_data)
20616 				optval = ((struct newreno *)tp->ccv->cc_data)->beta;
20617 			else
20618 				error = EINVAL;
20619 		}
20620 		break;
20621 		/*
20622 		 * Beta_ecn is the congestion control value for NewReno that influences how
20623 		 * much of a backoff happens when a ECN mark is detected. It is normally set
20624 		 * to 80 for 80% i.e. the cwnd is reduced by 20% of its previous value when
20625 		 * you exit recovery. Note that classic ECN has a beta of 50, it is only
20626 		 * ABE Ecn that uses this "less" value, but we do too with pacing :)
20627 		 */
20628 
20629 	case TCP_RACK_PACING_BETA_ECN:
20630 		if (strcmp(tp->cc_algo->name, CCALGONAME_NEWRENO) != 0)
20631 			error = EINVAL;
20632 		else if (rack->rc_pacing_cc_set == 0)
20633 			optval = rack->r_ctl.rc_saved_beta.beta_ecn;
20634 		else {
20635 			/*
20636 			 * Reach out into the CC data and report back what
20637 			 * I have previously set. Yeah it looks hackish but
20638 			 * we don't want to report the saved values.
20639 			 */
20640 			if (tp->ccv->cc_data)
20641 				optval = ((struct newreno *)tp->ccv->cc_data)->beta_ecn;
20642 			else
20643 				error = EINVAL;
20644 		}
20645 		break;
20646 	case TCP_RACK_DSACK_OPT:
20647 		optval = 0;
20648 		if (rack->rc_rack_tmr_std_based) {
20649 			optval |= 1;
20650 		}
20651 		if (rack->rc_rack_use_dsack) {
20652 			optval |= 2;
20653 		}
20654 		break;
20655  	case TCP_RACK_ENABLE_HYSTART:
20656 	{
20657 		if (tp->ccv->flags & CCF_HYSTART_ALLOWED) {
20658 			optval = RACK_HYSTART_ON;
20659 			if (tp->ccv->flags & CCF_HYSTART_CAN_SH_CWND)
20660 				optval = RACK_HYSTART_ON_W_SC;
20661 			if (tp->ccv->flags & CCF_HYSTART_CONS_SSTH)
20662 				optval = RACK_HYSTART_ON_W_SC_C;
20663 		} else {
20664 			optval = RACK_HYSTART_OFF;
20665 		}
20666 	}
20667 	break;
20668 	case TCP_FAST_RSM_HACK:
20669 		optval = rack->fast_rsm_hack;
20670 		break;
20671 	case TCP_DEFER_OPTIONS:
20672 		optval = rack->defer_options;
20673 		break;
20674 	case TCP_RACK_MEASURE_CNT:
20675 		optval = rack->r_ctl.req_measurements;
20676 		break;
20677 	case TCP_REC_ABC_VAL:
20678 		optval = rack->r_use_labc_for_rec;
20679 		break;
20680 	case TCP_RACK_ABC_VAL:
20681 		optval = rack->rc_labc;
20682 		break;
20683 	case TCP_HDWR_UP_ONLY:
20684 		optval= rack->r_up_only;
20685 		break;
20686 	case TCP_PACING_RATE_CAP:
20687 		loptval = rack->r_ctl.bw_rate_cap;
20688 		break;
20689 	case TCP_RACK_PROFILE:
20690 		/* You cannot retrieve a profile, its write only */
20691 		error = EINVAL;
20692 		break;
20693 	case TCP_USE_CMP_ACKS:
20694 		optval = rack->r_use_cmp_ack;
20695 		break;
20696 	case TCP_RACK_PACE_TO_FILL:
20697 		optval = rack->rc_pace_to_cwnd;
20698 		if (optval && rack->r_fill_less_agg)
20699 			optval++;
20700 		break;
20701 	case TCP_RACK_NO_PUSH_AT_MAX:
20702 		optval = rack->r_ctl.rc_no_push_at_mrtt;
20703 		break;
20704 	case TCP_SHARED_CWND_ENABLE:
20705 		optval = rack->rack_enable_scwnd;
20706 		break;
20707 	case TCP_RACK_NONRXT_CFG_RATE:
20708 		optval = rack->rack_rec_nonrxt_use_cr;
20709 		break;
20710 	case TCP_NO_PRR:
20711 		if (rack->rack_no_prr  == 1)
20712 			optval = 1;
20713 		else if (rack->no_prr_addback == 1)
20714 			optval = 2;
20715 		else
20716 			optval = 0;
20717 		break;
20718 	case TCP_RACK_DO_DETECTION:
20719 		optval = rack->do_detection;
20720 		break;
20721 	case TCP_RACK_MBUF_QUEUE:
20722 		/* Now do we use the LRO mbuf-queue feature */
20723 		optval = rack->r_mbuf_queue;
20724 		break;
20725 	case TCP_TIMELY_DYN_ADJ:
20726 		optval = rack->rc_gp_dyn_mul;
20727 		break;
20728 	case TCP_BBR_IWINTSO:
20729 		optval = rack->rc_init_win;
20730 		break;
20731 	case TCP_RACK_TLP_REDUCE:
20732 		/* RACK TLP cwnd reduction (bool) */
20733 		optval = rack->r_ctl.rc_tlp_cwnd_reduce;
20734 		break;
20735 	case TCP_BBR_RACK_INIT_RATE:
20736 		val = rack->r_ctl.init_rate;
20737 		/* convert to kbits per sec */
20738 		val *= 8;
20739 		val /= 1000;
20740 		optval = (uint32_t)val;
20741 		break;
20742 	case TCP_RACK_FORCE_MSEG:
20743 		optval = rack->rc_force_max_seg;
20744 		break;
20745 	case TCP_RACK_PACE_MAX_SEG:
20746 		/* Max segments in a pace */
20747 		optval = rack->rc_user_set_max_segs;
20748 		break;
20749 	case TCP_RACK_PACE_ALWAYS:
20750 		/* Use the always pace method */
20751 		optval = rack->rc_always_pace;
20752 		break;
20753 	case TCP_RACK_PRR_SENDALOT:
20754 		/* Allow PRR to send more than one seg */
20755 		optval = rack->r_ctl.rc_prr_sendalot;
20756 		break;
20757 	case TCP_RACK_MIN_TO:
20758 		/* Minimum time between rack t-o's in ms */
20759 		optval = rack->r_ctl.rc_min_to;
20760 		break;
20761 	case TCP_RACK_EARLY_SEG:
20762 		/* If early recovery max segments */
20763 		optval = rack->r_ctl.rc_early_recovery_segs;
20764 		break;
20765 	case TCP_RACK_REORD_THRESH:
20766 		/* RACK reorder threshold (shift amount) */
20767 		optval = rack->r_ctl.rc_reorder_shift;
20768 		break;
20769 	case TCP_RACK_REORD_FADE:
20770 		/* Does reordering fade after ms time */
20771 		optval = rack->r_ctl.rc_reorder_fade;
20772 		break;
20773 	case TCP_BBR_USE_RACK_RR:
20774 		/* Do we use the rack cheat for rxt */
20775 		optval = rack->use_rack_rr;
20776 		break;
20777 	case TCP_RACK_RR_CONF:
20778 		optval = rack->r_rr_config;
20779 		break;
20780 	case TCP_HDWR_RATE_CAP:
20781 		optval = rack->r_rack_hw_rate_caps;
20782 		break;
20783 	case TCP_BBR_HDWR_PACE:
20784 		optval = rack->rack_hdw_pace_ena;
20785 		break;
20786 	case TCP_RACK_TLP_THRESH:
20787 		/* RACK TLP theshold i.e. srtt+(srtt/N) */
20788 		optval = rack->r_ctl.rc_tlp_threshold;
20789 		break;
20790 	case TCP_RACK_PKT_DELAY:
20791 		/* RACK added ms i.e. rack-rtt + reord + N */
20792 		optval = rack->r_ctl.rc_pkt_delay;
20793 		break;
20794 	case TCP_RACK_TLP_USE:
20795 		optval = rack->rack_tlp_threshold_use;
20796 		break;
20797 	case TCP_RACK_PACE_RATE_CA:
20798 		optval = rack->r_ctl.rc_fixed_pacing_rate_ca;
20799 		break;
20800 	case TCP_RACK_PACE_RATE_SS:
20801 		optval = rack->r_ctl.rc_fixed_pacing_rate_ss;
20802 		break;
20803 	case TCP_RACK_PACE_RATE_REC:
20804 		optval = rack->r_ctl.rc_fixed_pacing_rate_rec;
20805 		break;
20806 	case TCP_RACK_GP_INCREASE_SS:
20807 		optval = rack->r_ctl.rack_per_of_gp_ca;
20808 		break;
20809 	case TCP_RACK_GP_INCREASE_CA:
20810 		optval = rack->r_ctl.rack_per_of_gp_ss;
20811 		break;
20812 	case TCP_BBR_RACK_RTT_USE:
20813 		optval = rack->r_ctl.rc_rate_sample_method;
20814 		break;
20815 	case TCP_DELACK:
20816 		optval = tp->t_delayed_ack;
20817 		break;
20818 	case TCP_DATA_AFTER_CLOSE:
20819 		optval = rack->rc_allow_data_af_clo;
20820 		break;
20821 	case TCP_SHARED_CWND_TIME_LIMIT:
20822 		optval = rack->r_limit_scw;
20823 		break;
20824 	case TCP_RACK_TIMER_SLOP:
20825 		optval = rack->r_ctl.timer_slop;
20826 		break;
20827 	default:
20828 		return (tcp_default_ctloutput(inp, sopt));
20829 		break;
20830 	}
20831 	INP_WUNLOCK(inp);
20832 	if (error == 0) {
20833 		if (TCP_PACING_RATE_CAP)
20834 			error = sooptcopyout(sopt, &loptval, sizeof loptval);
20835 		else
20836 			error = sooptcopyout(sopt, &optval, sizeof optval);
20837 	}
20838 	return (error);
20839 }
20840 
20841 static int
20842 rack_ctloutput(struct inpcb *inp, struct sockopt *sopt)
20843 {
20844 	if (sopt->sopt_dir == SOPT_SET) {
20845 		return (rack_set_sockopt(inp, sopt));
20846 	} else if (sopt->sopt_dir == SOPT_GET) {
20847 		return (rack_get_sockopt(inp, sopt));
20848 	} else {
20849 		panic("%s: sopt_dir $%d", __func__, sopt->sopt_dir);
20850 	}
20851 }
20852 
20853 static const char *rack_stack_names[] = {
20854 	__XSTRING(STACKNAME),
20855 #ifdef STACKALIAS
20856 	__XSTRING(STACKALIAS),
20857 #endif
20858 };
20859 
20860 static int
20861 rack_ctor(void *mem, int32_t size, void *arg, int32_t how)
20862 {
20863 	memset(mem, 0, size);
20864 	return (0);
20865 }
20866 
20867 static void
20868 rack_dtor(void *mem, int32_t size, void *arg)
20869 {
20870 
20871 }
20872 
20873 static bool rack_mod_inited = false;
20874 
20875 static int
20876 tcp_addrack(module_t mod, int32_t type, void *data)
20877 {
20878 	int32_t err = 0;
20879 	int num_stacks;
20880 
20881 	switch (type) {
20882 	case MOD_LOAD:
20883 		rack_zone = uma_zcreate(__XSTRING(MODNAME) "_map",
20884 		    sizeof(struct rack_sendmap),
20885 		    rack_ctor, rack_dtor, NULL, NULL, UMA_ALIGN_PTR, 0);
20886 
20887 		rack_pcb_zone = uma_zcreate(__XSTRING(MODNAME) "_pcb",
20888 		    sizeof(struct tcp_rack),
20889 		    rack_ctor, NULL, NULL, NULL, UMA_ALIGN_CACHE, 0);
20890 
20891 		sysctl_ctx_init(&rack_sysctl_ctx);
20892 		rack_sysctl_root = SYSCTL_ADD_NODE(&rack_sysctl_ctx,
20893 		    SYSCTL_STATIC_CHILDREN(_net_inet_tcp),
20894 		    OID_AUTO,
20895 #ifdef STACKALIAS
20896 		    __XSTRING(STACKALIAS),
20897 #else
20898 		    __XSTRING(STACKNAME),
20899 #endif
20900 		    CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
20901 		    "");
20902 		if (rack_sysctl_root == NULL) {
20903 			printf("Failed to add sysctl node\n");
20904 			err = EFAULT;
20905 			goto free_uma;
20906 		}
20907 		rack_init_sysctls();
20908 		num_stacks = nitems(rack_stack_names);
20909 		err = register_tcp_functions_as_names(&__tcp_rack, M_WAITOK,
20910 		    rack_stack_names, &num_stacks);
20911 		if (err) {
20912 			printf("Failed to register %s stack name for "
20913 			    "%s module\n", rack_stack_names[num_stacks],
20914 			    __XSTRING(MODNAME));
20915 			sysctl_ctx_free(&rack_sysctl_ctx);
20916 free_uma:
20917 			uma_zdestroy(rack_zone);
20918 			uma_zdestroy(rack_pcb_zone);
20919 			rack_counter_destroy();
20920 			printf("Failed to register rack module -- err:%d\n", err);
20921 			return (err);
20922 		}
20923 		tcp_lro_reg_mbufq();
20924 		rack_mod_inited = true;
20925 		break;
20926 	case MOD_QUIESCE:
20927 		err = deregister_tcp_functions(&__tcp_rack, true, false);
20928 		break;
20929 	case MOD_UNLOAD:
20930 		err = deregister_tcp_functions(&__tcp_rack, false, true);
20931 		if (err == EBUSY)
20932 			break;
20933 		if (rack_mod_inited) {
20934 			uma_zdestroy(rack_zone);
20935 			uma_zdestroy(rack_pcb_zone);
20936 			sysctl_ctx_free(&rack_sysctl_ctx);
20937 			rack_counter_destroy();
20938 			rack_mod_inited = false;
20939 		}
20940 		tcp_lro_dereg_mbufq();
20941 		err = 0;
20942 		break;
20943 	default:
20944 		return (EOPNOTSUPP);
20945 	}
20946 	return (err);
20947 }
20948 
20949 static moduledata_t tcp_rack = {
20950 	.name = __XSTRING(MODNAME),
20951 	.evhand = tcp_addrack,
20952 	.priv = 0
20953 };
20954 
20955 MODULE_VERSION(MODNAME, 1);
20956 DECLARE_MODULE(MODNAME, tcp_rack, SI_SUB_PROTO_DOMAIN, SI_ORDER_ANY);
20957 MODULE_DEPEND(MODNAME, tcphpts, 1, 1, 1);
20958