xref: /freebsd/sys/netinet/tcp_stacks/rack.c (revision e9a994639b2af232f994ba2ad23ca45a17718d2b) 
1 /*-
2  * Copyright (c) 2016-2020 Netflix, Inc.
3  *
4  * Redistribution and use in source and binary forms, with or without
5  * modification, are permitted provided that the following conditions
6  * are met:
7  * 1. Redistributions of source code must retain the above copyright
8  *    notice, this list of conditions and the following disclaimer.
9  * 2. Redistributions in binary form must reproduce the above copyright
10  *    notice, this list of conditions and the following disclaimer in the
11  *    documentation and/or other materials provided with the distribution.
12  *
13  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
14  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
15  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
16  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
17  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
18  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
19  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
20  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
21  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
22  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
23  * SUCH DAMAGE.
24  *
25  */
26 
27 #include <sys/cdefs.h>
28 __FBSDID("$FreeBSD$");
29 
30 #include "opt_inet.h"
31 #include "opt_inet6.h"
32 #include "opt_ipsec.h"
33 #include "opt_tcpdebug.h"
34 #include "opt_ratelimit.h"
35 #include "opt_kern_tls.h"
36 #include <sys/param.h>
37 #include <sys/arb.h>
38 #include <sys/module.h>
39 #include <sys/kernel.h>
40 #ifdef TCP_HHOOK
41 #include <sys/hhook.h>
42 #endif
43 #include <sys/lock.h>
44 #include <sys/malloc.h>
45 #include <sys/lock.h>
46 #include <sys/mutex.h>
47 #include <sys/mbuf.h>
48 #include <sys/proc.h>		/* for proc0 declaration */
49 #include <sys/socket.h>
50 #include <sys/socketvar.h>
51 #include <sys/sysctl.h>
52 #include <sys/systm.h>
53 #ifdef STATS
54 #include <sys/qmath.h>
55 #include <sys/tree.h>
56 #include <sys/stats.h> /* Must come after qmath.h and tree.h */
57 #else
58 #include <sys/tree.h>
59 #endif
60 #include <sys/refcount.h>
61 #include <sys/queue.h>
62 #include <sys/tim_filter.h>
63 #include <sys/smp.h>
64 #include <sys/kthread.h>
65 #include <sys/kern_prefetch.h>
66 #include <sys/protosw.h>
67 #ifdef TCP_ACCOUNTING
68 #include <sys/sched.h>
69 #include <machine/cpu.h>
70 #endif
71 #include <vm/uma.h>
72 
73 #include <net/route.h>
74 #include <net/route/nhop.h>
75 #include <net/vnet.h>
76 
77 #define TCPSTATES		/* for logging */
78 
79 #include <netinet/in.h>
80 #include <netinet/in_kdtrace.h>
81 #include <netinet/in_pcb.h>
82 #include <netinet/ip.h>
83 #include <netinet/ip_icmp.h>	/* required for icmp_var.h */
84 #include <netinet/icmp_var.h>	/* for ICMP_BANDLIM */
85 #include <netinet/ip_var.h>
86 #include <netinet/ip6.h>
87 #include <netinet6/in6_pcb.h>
88 #include <netinet6/ip6_var.h>
89 #include <netinet/tcp.h>
90 #define	TCPOUTFLAGS
91 #include <netinet/tcp_fsm.h>
92 #include <netinet/tcp_log_buf.h>
93 #include <netinet/tcp_seq.h>
94 #include <netinet/tcp_timer.h>
95 #include <netinet/tcp_var.h>
96 #include <netinet/tcp_hpts.h>
97 #include <netinet/tcp_ratelimit.h>
98 #include <netinet/tcp_accounting.h>
99 #include <netinet/tcpip.h>
100 #include <netinet/cc/cc.h>
101 #include <netinet/cc/cc_newreno.h>
102 #include <netinet/tcp_fastopen.h>
103 #include <netinet/tcp_lro.h>
104 #ifdef NETFLIX_SHARED_CWND
105 #include <netinet/tcp_shared_cwnd.h>
106 #endif
107 #ifdef TCPDEBUG
108 #include <netinet/tcp_debug.h>
109 #endif				/* TCPDEBUG */
110 #ifdef TCP_OFFLOAD
111 #include <netinet/tcp_offload.h>
112 #endif
113 #ifdef INET6
114 #include <netinet6/tcp6_var.h>
115 #endif
116 
117 #include <netipsec/ipsec_support.h>
118 
119 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
120 #include <netipsec/ipsec.h>
121 #include <netipsec/ipsec6.h>
122 #endif				/* IPSEC */
123 
124 #include <netinet/udp.h>
125 #include <netinet/udp_var.h>
126 #include <machine/in_cksum.h>
127 
128 #ifdef MAC
129 #include <security/mac/mac_framework.h>
130 #endif
131 #include "sack_filter.h"
132 #include "tcp_rack.h"
133 #include "rack_bbr_common.h"
134 
135 uma_zone_t rack_zone;
136 uma_zone_t rack_pcb_zone;
137 
138 #ifndef TICKS2SBT
139 #define	TICKS2SBT(__t)	(tick_sbt * ((sbintime_t)(__t)))
140 #endif
141 
142 VNET_DECLARE(uint32_t, newreno_beta);
143 VNET_DECLARE(uint32_t, newreno_beta_ecn);
144 #define V_newreno_beta VNET(newreno_beta)
145 #define V_newreno_beta_ecn VNET(newreno_beta_ecn)
146 
147 
148 MALLOC_DEFINE(M_TCPFSB, "tcp_fsb", "TCP fast send block");
149 MALLOC_DEFINE(M_TCPDO, "tcp_do", "TCP deferred options");
150 
151 struct sysctl_ctx_list rack_sysctl_ctx;
152 struct sysctl_oid *rack_sysctl_root;
153 
154 #define CUM_ACKED 1
155 #define SACKED 2
156 
157 /*
158  * The RACK module incorporates a number of
159  * TCP ideas that have been put out into the IETF
160  * over the last few years:
161  * - Matt Mathis's Rate Halving which slowly drops
162  *    the congestion window so that the ack clock can
163  *    be maintained during a recovery.
164  * - Yuchung Cheng's RACK TCP (for which its named) that
165  *    will stop us using the number of dup acks and instead
166  *    use time as the gage of when we retransmit.
167  * - Reorder Detection of RFC4737 and the Tail-Loss probe draft
168  *    of Dukkipati et.al.
169  * RACK depends on SACK, so if an endpoint arrives that
170  * cannot do SACK the state machine below will shuttle the
171  * connection back to using the "default" TCP stack that is
172  * in FreeBSD.
173  *
174  * To implement RACK the original TCP stack was first decomposed
175  * into a functional state machine with individual states
176  * for each of the possible TCP connection states. The do_segement
177  * functions role in life is to mandate the connection supports SACK
178  * initially and then assure that the RACK state matches the conenction
179  * state before calling the states do_segment function. Each
180  * state is simplified due to the fact that the original do_segment
181  * has been decomposed and we *know* what state we are in (no
182  * switches on the state) and all tests for SACK are gone. This
183  * greatly simplifies what each state does.
184  *
185  * TCP output is also over-written with a new version since it
186  * must maintain the new rack scoreboard.
187  *
188  */
189 static int32_t rack_tlp_thresh = 1;
190 static int32_t rack_tlp_limit = 2;	/* No more than 2 TLPs w-out new data */
191 static int32_t rack_tlp_use_greater = 1;
192 static int32_t rack_reorder_thresh = 2;
193 static int32_t rack_reorder_fade = 60000000;	/* 0 - never fade, def 60,000,000
194 						 * - 60 seconds */
195 static uint8_t rack_req_measurements = 1;
196 /* Attack threshold detections */
197 static uint32_t rack_highest_sack_thresh_seen = 0;
198 static uint32_t rack_highest_move_thresh_seen = 0;
199 static int32_t rack_enable_hw_pacing = 0; /* Due to CCSP keep it off by default */
200 static int32_t rack_hw_pace_extra_slots = 2;	/* 2 extra MSS time betweens */
201 static int32_t rack_hw_rate_caps = 1; /* 1; */
202 static int32_t rack_hw_rate_min = 0; /* 1500000;*/
203 static int32_t rack_hw_rate_to_low = 0; /* 1200000; */
204 static int32_t rack_hw_up_only = 1;
205 static int32_t rack_stats_gets_ms_rtt = 1;
206 static int32_t rack_prr_addbackmax = 2;
207 static int32_t rack_do_hystart = 0;
208 
209 static int32_t rack_pkt_delay = 1000;
210 static int32_t rack_send_a_lot_in_prr = 1;
211 static int32_t rack_min_to = 1000;	/* Number of microsecond  min timeout */
212 static int32_t rack_verbose_logging = 0;
213 static int32_t rack_ignore_data_after_close = 1;
214 static int32_t rack_enable_shared_cwnd = 1;
215 static int32_t rack_use_cmp_acks = 1;
216 static int32_t rack_use_fsb = 1;
217 static int32_t rack_use_rfo = 1;
218 static int32_t rack_use_rsm_rfo = 1;
219 static int32_t rack_max_abc_post_recovery = 2;
220 static int32_t rack_client_low_buf = 0;
221 static int32_t rack_dsack_std_based = 0x3;	/* bit field bit 1 sets rc_rack_tmr_std_based and bit 2 sets rc_rack_use_dsack */
222 #ifdef TCP_ACCOUNTING
223 static int32_t rack_tcp_accounting = 0;
224 #endif
225 static int32_t rack_limits_scwnd = 1;
226 static int32_t rack_enable_mqueue_for_nonpaced = 0;
227 static int32_t rack_disable_prr = 0;
228 static int32_t use_rack_rr = 1;
229 static int32_t rack_non_rxt_use_cr = 0; /* does a non-rxt in recovery use the configured rate (ss/ca)? */
230 static int32_t rack_persist_min = 250000;	/* 250usec */
231 static int32_t rack_persist_max = 2000000;	/* 2 Second in usec's */
232 static int32_t rack_sack_not_required = 1;	/* set to one to allow non-sack to use rack */
233 static int32_t rack_default_init_window = 0;	/* Use system default */
234 static int32_t rack_limit_time_with_srtt = 0;
235 static int32_t rack_autosndbuf_inc = 20;	/* In percentage form */
236 static int32_t rack_enobuf_hw_boost_mult = 2;	/* How many times the hw rate we boost slot using time_between */
237 static int32_t rack_enobuf_hw_max = 12000;	/* 12 ms in usecs */
238 static int32_t rack_enobuf_hw_min = 10000;	/* 10 ms in usecs */
239 static int32_t rack_hw_rwnd_factor = 2;		/* How many max_segs the rwnd must be before we hold off sending */
240 /*
241  * Currently regular tcp has a rto_min of 30ms
242  * the backoff goes 12 times so that ends up
243  * being a total of 122.850 seconds before a
244  * connection is killed.
245  */
246 static uint32_t rack_def_data_window = 20;
247 static uint32_t rack_goal_bdp = 2;
248 static uint32_t rack_min_srtts = 1;
249 static uint32_t rack_min_measure_usec = 0;
250 static int32_t rack_tlp_min = 10000;	/* 10ms */
251 static int32_t rack_rto_min = 30000;	/* 30,000 usec same as main freebsd */
252 static int32_t rack_rto_max = 4000000;	/* 4 seconds in usec's */
253 static const int32_t rack_free_cache = 2;
254 static int32_t rack_hptsi_segments = 40;
255 static int32_t rack_rate_sample_method = USE_RTT_LOW;
256 static int32_t rack_pace_every_seg = 0;
257 static int32_t rack_delayed_ack_time = 40000;	/* 40ms in usecs */
258 static int32_t rack_slot_reduction = 4;
259 static int32_t rack_wma_divisor = 8;		/* For WMA calculation */
260 static int32_t rack_cwnd_block_ends_measure = 0;
261 static int32_t rack_rwnd_block_ends_measure = 0;
262 static int32_t rack_def_profile = 0;
263 
264 static int32_t rack_lower_cwnd_at_tlp = 0;
265 static int32_t rack_limited_retran = 0;
266 static int32_t rack_always_send_oldest = 0;
267 static int32_t rack_tlp_threshold_use = TLP_USE_TWO_ONE;
268 
269 static uint16_t rack_per_of_gp_ss = 250;	/* 250 % slow-start */
270 static uint16_t rack_per_of_gp_ca = 200;	/* 200 % congestion-avoidance */
271 static uint16_t rack_per_of_gp_rec = 200;	/* 200 % of bw */
272 
273 /* Probertt */
274 static uint16_t rack_per_of_gp_probertt = 60;	/* 60% of bw */
275 static uint16_t rack_per_of_gp_lowthresh = 40;	/* 40% is bottom */
276 static uint16_t rack_per_of_gp_probertt_reduce = 10; /* 10% reduction */
277 static uint16_t rack_atexit_prtt_hbp = 130;	/* Clamp to 130% on exit prtt if highly buffered path */
278 static uint16_t rack_atexit_prtt = 130;	/* Clamp to 100% on exit prtt if non highly buffered path */
279 
280 static uint32_t rack_max_drain_wait = 2;	/* How man gp srtt's before we give up draining */
281 static uint32_t rack_must_drain = 1;		/* How many GP srtt's we *must* wait */
282 static uint32_t rack_probertt_use_min_rtt_entry = 1;	/* Use the min to calculate the goal else gp_srtt */
283 static uint32_t rack_probertt_use_min_rtt_exit = 0;
284 static uint32_t rack_probe_rtt_sets_cwnd = 0;
285 static uint32_t rack_probe_rtt_safety_val = 2000000;	/* No more than 2 sec in probe-rtt */
286 static uint32_t rack_time_between_probertt = 9600000;	/* 9.6 sec in usecs */
287 static uint32_t rack_probertt_gpsrtt_cnt_mul = 0;	/* How many srtt periods does probe-rtt last top fraction */
288 static uint32_t rack_probertt_gpsrtt_cnt_div = 0;	/* How many srtt periods does probe-rtt last bottom fraction */
289 static uint32_t rack_min_probertt_hold = 40000;		/* Equal to delayed ack time */
290 static uint32_t rack_probertt_filter_life = 10000000;
291 static uint32_t rack_probertt_lower_within = 10;
292 static uint32_t rack_min_rtt_movement = 250000;	/* Must move at least 250ms (in microseconds)  to count as a lowering */
293 static int32_t rack_pace_one_seg = 0;		/* Shall we pace for less than 1.4Meg 1MSS at a time */
294 static int32_t rack_probertt_clear_is = 1;
295 static int32_t rack_max_drain_hbp = 1;		/* Extra drain times gpsrtt for highly buffered paths */
296 static int32_t rack_hbp_thresh = 3;		/* what is the divisor max_rtt/min_rtt to decided a hbp */
297 
298 /* Part of pacing */
299 static int32_t rack_max_per_above = 30;		/* When we go to increment stop if above 100+this% */
300 
301 /* Timely information */
302 /* Combine these two gives the range of 'no change' to bw */
303 /* ie the up/down provide the upper and lower bound */
304 static int32_t rack_gp_per_bw_mul_up = 2;	/* 2% */
305 static int32_t rack_gp_per_bw_mul_down = 4;	/* 4% */
306 static int32_t rack_gp_rtt_maxmul = 3;		/* 3 x maxmin */
307 static int32_t rack_gp_rtt_minmul = 1;		/* minrtt + (minrtt/mindiv) is lower rtt */
308 static int32_t rack_gp_rtt_mindiv = 4;		/* minrtt + (minrtt * minmul/mindiv) is lower rtt */
309 static int32_t rack_gp_decrease_per = 20;	/* 20% decrease in multipler */
310 static int32_t rack_gp_increase_per = 2;	/* 2% increase in multipler */
311 static int32_t rack_per_lower_bound = 50;	/* Don't allow to drop below this multiplier */
312 static int32_t rack_per_upper_bound_ss = 0;	/* Don't allow SS to grow above this */
313 static int32_t rack_per_upper_bound_ca = 0;	/* Don't allow CA to grow above this */
314 static int32_t rack_do_dyn_mul = 0;		/* Are the rack gp multipliers dynamic */
315 static int32_t rack_gp_no_rec_chg = 1;		/* Prohibit recovery from reducing it's multiplier */
316 static int32_t rack_timely_dec_clear = 6;	/* Do we clear decrement count at a value (6)? */
317 static int32_t rack_timely_max_push_rise = 3;	/* One round of pushing */
318 static int32_t rack_timely_max_push_drop = 3;	/* Three round of pushing */
319 static int32_t rack_timely_min_segs = 4;	/* 4 segment minimum */
320 static int32_t rack_use_max_for_nobackoff = 0;
321 static int32_t rack_timely_int_timely_only = 0;	/* do interim timely's only use the timely algo (no b/w changes)? */
322 static int32_t rack_timely_no_stopping = 0;
323 static int32_t rack_down_raise_thresh = 100;
324 static int32_t rack_req_segs = 1;
325 static uint64_t rack_bw_rate_cap = 0;
326 
327 /* Weird delayed ack mode */
328 static int32_t rack_use_imac_dack = 0;
329 /* Rack specific counters */
330 counter_u64_t rack_badfr;
331 counter_u64_t rack_badfr_bytes;
332 counter_u64_t rack_rtm_prr_retran;
333 counter_u64_t rack_rtm_prr_newdata;
334 counter_u64_t rack_timestamp_mismatch;
335 counter_u64_t rack_reorder_seen;
336 counter_u64_t rack_paced_segments;
337 counter_u64_t rack_unpaced_segments;
338 counter_u64_t rack_calc_zero;
339 counter_u64_t rack_calc_nonzero;
340 counter_u64_t rack_saw_enobuf;
341 counter_u64_t rack_saw_enobuf_hw;
342 counter_u64_t rack_saw_enetunreach;
343 counter_u64_t rack_per_timer_hole;
344 counter_u64_t rack_large_ackcmp;
345 counter_u64_t rack_small_ackcmp;
346 #ifdef INVARIANTS
347 counter_u64_t rack_adjust_map_bw;
348 #endif
349 /* Tail loss probe counters */
350 counter_u64_t rack_tlp_tot;
351 counter_u64_t rack_tlp_newdata;
352 counter_u64_t rack_tlp_retran;
353 counter_u64_t rack_tlp_retran_bytes;
354 counter_u64_t rack_tlp_retran_fail;
355 counter_u64_t rack_to_tot;
356 counter_u64_t rack_to_arm_rack;
357 counter_u64_t rack_to_arm_tlp;
358 counter_u64_t rack_hot_alloc;
359 counter_u64_t rack_to_alloc;
360 counter_u64_t rack_to_alloc_hard;
361 counter_u64_t rack_to_alloc_emerg;
362 counter_u64_t rack_to_alloc_limited;
363 counter_u64_t rack_alloc_limited_conns;
364 counter_u64_t rack_split_limited;
365 
366 #define MAX_NUM_OF_CNTS 13
367 counter_u64_t rack_proc_comp_ack[MAX_NUM_OF_CNTS];
368 counter_u64_t rack_multi_single_eq;
369 counter_u64_t rack_proc_non_comp_ack;
370 
371 counter_u64_t rack_fto_send;
372 counter_u64_t rack_fto_rsm_send;
373 counter_u64_t rack_nfto_resend;
374 counter_u64_t rack_non_fto_send;
375 counter_u64_t rack_extended_rfo;
376 
377 counter_u64_t rack_sack_proc_all;
378 counter_u64_t rack_sack_proc_short;
379 counter_u64_t rack_sack_proc_restart;
380 counter_u64_t rack_sack_attacks_detected;
381 counter_u64_t rack_sack_attacks_reversed;
382 counter_u64_t rack_sack_used_next_merge;
383 counter_u64_t rack_sack_splits;
384 counter_u64_t rack_sack_used_prev_merge;
385 counter_u64_t rack_sack_skipped_acked;
386 counter_u64_t rack_ack_total;
387 counter_u64_t rack_express_sack;
388 counter_u64_t rack_sack_total;
389 counter_u64_t rack_move_none;
390 counter_u64_t rack_move_some;
391 
392 counter_u64_t rack_used_tlpmethod;
393 counter_u64_t rack_used_tlpmethod2;
394 counter_u64_t rack_enter_tlp_calc;
395 counter_u64_t rack_input_idle_reduces;
396 counter_u64_t rack_collapsed_win;
397 counter_u64_t rack_tlp_does_nada;
398 counter_u64_t rack_try_scwnd;
399 counter_u64_t rack_hw_pace_init_fail;
400 counter_u64_t rack_hw_pace_lost;
401 counter_u64_t rack_sbsndptr_right;
402 counter_u64_t rack_sbsndptr_wrong;
403 
404 /* Temp CPU counters */
405 counter_u64_t rack_find_high;
406 
407 counter_u64_t rack_progress_drops;
408 counter_u64_t rack_out_size[TCP_MSS_ACCT_SIZE];
409 counter_u64_t rack_opts_arry[RACK_OPTS_SIZE];
410 
411 
412 #define	RACK_REXMTVAL(tp) max(rack_rto_min, ((tp)->t_srtt + ((tp)->t_rttvar << 2)))
413 
414 #define	RACK_TCPT_RANGESET(tv, value, tvmin, tvmax, slop) do {	\
415 	(tv) = (value) + slop;	 \
416 	if ((u_long)(tv) < (u_long)(tvmin)) \
417 		(tv) = (tvmin); \
418 	if ((u_long)(tv) > (u_long)(tvmax)) \
419 		(tv) = (tvmax); \
420 } while (0)
421 
422 static void
423 rack_log_progress_event(struct tcp_rack *rack, struct tcpcb *tp, uint32_t tick,  int event, int line);
424 
425 static int
426 rack_process_ack(struct mbuf *m, struct tcphdr *th,
427     struct socket *so, struct tcpcb *tp, struct tcpopt *to,
428     uint32_t tiwin, int32_t tlen, int32_t * ofia, int32_t thflags, int32_t * ret_val);
429 static int
430 rack_process_data(struct mbuf *m, struct tcphdr *th,
431     struct socket *so, struct tcpcb *tp, int32_t drop_hdrlen, int32_t tlen,
432     uint32_t tiwin, int32_t thflags, int32_t nxt_pkt);
433 static void
434 rack_ack_received(struct tcpcb *tp, struct tcp_rack *rack,
435    uint32_t th_ack, uint16_t nsegs, uint16_t type, int32_t recovery);
436 static struct rack_sendmap *rack_alloc(struct tcp_rack *rack);
437 static struct rack_sendmap *rack_alloc_limit(struct tcp_rack *rack,
438     uint8_t limit_type);
439 static struct rack_sendmap *
440 rack_check_recovery_mode(struct tcpcb *tp,
441     uint32_t tsused);
442 static void
443 rack_cong_signal(struct tcpcb *tp,
444 		 uint32_t type, uint32_t ack);
445 static void rack_counter_destroy(void);
446 static int
447 rack_ctloutput(struct socket *so, struct sockopt *sopt,
448     struct inpcb *inp, struct tcpcb *tp);
449 static int32_t rack_ctor(void *mem, int32_t size, void *arg, int32_t how);
450 static void
451 rack_set_pace_segments(struct tcpcb *tp, struct tcp_rack *rack, uint32_t line, uint64_t *fill_override);
452 static void
453 rack_do_segment(struct mbuf *m, struct tcphdr *th,
454     struct socket *so, struct tcpcb *tp, int32_t drop_hdrlen, int32_t tlen,
455     uint8_t iptos);
456 static void rack_dtor(void *mem, int32_t size, void *arg);
457 static void
458 rack_log_alt_to_to_cancel(struct tcp_rack *rack,
459     uint32_t flex1, uint32_t flex2,
460     uint32_t flex3, uint32_t flex4,
461     uint32_t flex5, uint32_t flex6,
462     uint16_t flex7, uint8_t mod);
463 
464 static void
465 rack_log_pacing_delay_calc(struct tcp_rack *rack, uint32_t len, uint32_t slot,
466    uint64_t bw_est, uint64_t bw, uint64_t len_time, int method, int line,
467    struct rack_sendmap *rsm, uint8_t quality);
468 static struct rack_sendmap *
469 rack_find_high_nonack(struct tcp_rack *rack,
470     struct rack_sendmap *rsm);
471 static struct rack_sendmap *rack_find_lowest_rsm(struct tcp_rack *rack);
472 static void rack_free(struct tcp_rack *rack, struct rack_sendmap *rsm);
473 static void rack_fini(struct tcpcb *tp, int32_t tcb_is_purged);
474 static int
475 rack_get_sockopt(struct socket *so, struct sockopt *sopt,
476     struct inpcb *inp, struct tcpcb *tp, struct tcp_rack *rack);
477 static void
478 rack_do_goodput_measurement(struct tcpcb *tp, struct tcp_rack *rack,
479 			    tcp_seq th_ack, int line, uint8_t quality);
480 static uint32_t
481 rack_get_pacing_len(struct tcp_rack *rack, uint64_t bw, uint32_t mss);
482 static int32_t rack_handoff_ok(struct tcpcb *tp);
483 static int32_t rack_init(struct tcpcb *tp);
484 static void rack_init_sysctls(void);
485 static void
486 rack_log_ack(struct tcpcb *tp, struct tcpopt *to,
487     struct tcphdr *th, int entered_rec, int dup_ack_struck);
488 static void
489 rack_log_output(struct tcpcb *tp, struct tcpopt *to, int32_t len,
490     uint32_t seq_out, uint8_t th_flags, int32_t err, uint64_t ts,
491     struct rack_sendmap *hintrsm, uint16_t add_flags, struct mbuf *s_mb, uint32_t s_moff, int hw_tls);
492 
493 static void
494 rack_log_sack_passed(struct tcpcb *tp, struct tcp_rack *rack,
495     struct rack_sendmap *rsm);
496 static void rack_log_to_event(struct tcp_rack *rack, int32_t to_num, struct rack_sendmap *rsm);
497 static int32_t rack_output(struct tcpcb *tp);
498 
499 static uint32_t
500 rack_proc_sack_blk(struct tcpcb *tp, struct tcp_rack *rack,
501     struct sackblk *sack, struct tcpopt *to, struct rack_sendmap **prsm,
502     uint32_t cts, int *moved_two);
503 static void rack_post_recovery(struct tcpcb *tp, uint32_t th_seq);
504 static void rack_remxt_tmr(struct tcpcb *tp);
505 static int
506 rack_set_sockopt(struct socket *so, struct sockopt *sopt,
507     struct inpcb *inp, struct tcpcb *tp, struct tcp_rack *rack);
508 static void rack_set_state(struct tcpcb *tp, struct tcp_rack *rack);
509 static int32_t rack_stopall(struct tcpcb *tp);
510 static void
511 rack_timer_activate(struct tcpcb *tp, uint32_t timer_type,
512     uint32_t delta);
513 static int32_t rack_timer_active(struct tcpcb *tp, uint32_t timer_type);
514 static void rack_timer_cancel(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cts, int line);
515 static void rack_timer_stop(struct tcpcb *tp, uint32_t timer_type);
516 static uint32_t
517 rack_update_entry(struct tcpcb *tp, struct tcp_rack *rack,
518     struct rack_sendmap *rsm, uint64_t ts, int32_t * lenp, uint16_t add_flag);
519 static void
520 rack_update_rsm(struct tcpcb *tp, struct tcp_rack *rack,
521     struct rack_sendmap *rsm, uint64_t ts, uint16_t add_flag);
522 static int
523 rack_update_rtt(struct tcpcb *tp, struct tcp_rack *rack,
524     struct rack_sendmap *rsm, struct tcpopt *to, uint32_t cts, int32_t ack_type, tcp_seq th_ack);
525 static int32_t tcp_addrack(module_t mod, int32_t type, void *data);
526 static int
527 rack_do_close_wait(struct mbuf *m, struct tcphdr *th,
528     struct socket *so, struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen,
529     int32_t tlen, uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos);
530 static int
531 rack_do_closing(struct mbuf *m, struct tcphdr *th,
532     struct socket *so, struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen,
533     int32_t tlen, uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos);
534 static int
535 rack_do_established(struct mbuf *m, struct tcphdr *th,
536     struct socket *so, struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen,
537     int32_t tlen, uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos);
538 static int
539 rack_do_fastnewdata(struct mbuf *m, struct tcphdr *th,
540     struct socket *so, struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen,
541     int32_t tlen, uint32_t tiwin, int32_t nxt_pkt, uint8_t iptos);
542 static int
543 rack_do_fin_wait_1(struct mbuf *m, struct tcphdr *th,
544     struct socket *so, struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen,
545     int32_t tlen, uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos);
546 static int
547 rack_do_fin_wait_2(struct mbuf *m, struct tcphdr *th,
548     struct socket *so, struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen,
549     int32_t tlen, uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos);
550 static int
551 rack_do_lastack(struct mbuf *m, struct tcphdr *th,
552     struct socket *so, struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen,
553     int32_t tlen, uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos);
554 static int
555 rack_do_syn_recv(struct mbuf *m, struct tcphdr *th,
556     struct socket *so, struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen,
557     int32_t tlen, uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos);
558 static int
559 rack_do_syn_sent(struct mbuf *m, struct tcphdr *th,
560     struct socket *so, struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen,
561     int32_t tlen, uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos);
562 struct rack_sendmap *
563 tcp_rack_output(struct tcpcb *tp, struct tcp_rack *rack,
564     uint32_t tsused);
565 static void tcp_rack_xmit_timer(struct tcp_rack *rack, int32_t rtt,
566     uint32_t len, uint32_t us_tim, int confidence, struct rack_sendmap *rsm, uint16_t rtrcnt);
567 static void
568      tcp_rack_partialack(struct tcpcb *tp);
569 static int
570 rack_set_profile(struct tcp_rack *rack, int prof);
571 static void
572 rack_apply_deferred_options(struct tcp_rack *rack);
573 
574 int32_t rack_clear_counter=0;
575 
576 static void
577 rack_set_cc_pacing(struct tcp_rack *rack)
578 {
579 	struct sockopt sopt;
580 	struct cc_newreno_opts opt;
581 	struct newreno old, *ptr;
582 	struct tcpcb *tp;
583 	int error;
584 
585 	if (rack->rc_pacing_cc_set)
586 		return;
587 
588 	tp = rack->rc_tp;
589 	if (tp->cc_algo == NULL) {
590 		/* Tcb is leaving */
591 		printf("No cc algorithm?\n");
592 		return;
593 	}
594 	rack->rc_pacing_cc_set = 1;
595 	if (strcmp(tp->cc_algo->name, CCALGONAME_NEWRENO) != 0) {
596 		/* Not new-reno we can't play games with beta! */
597 		goto out;
598 	}
599 	ptr = ((struct newreno *)tp->ccv->cc_data);
600 	if (CC_ALGO(tp)->ctl_output == NULL)  {
601 		/* Huh, why does new_reno no longer have a set function? */
602 		printf("no ctl_output for algo:%s\n", tp->cc_algo->name);
603 		goto out;
604 	}
605 	if (ptr == NULL) {
606 		/* Just the default values */
607 		old.beta = V_newreno_beta_ecn;
608 		old.beta_ecn = V_newreno_beta_ecn;
609 		old.newreno_flags = 0;
610 	} else {
611 		old.beta = ptr->beta;
612 		old.beta_ecn = ptr->beta_ecn;
613 		old.newreno_flags = ptr->newreno_flags;
614 	}
615 	sopt.sopt_valsize = sizeof(struct cc_newreno_opts);
616 	sopt.sopt_dir = SOPT_SET;
617 	opt.name = CC_NEWRENO_BETA;
618 	opt.val = rack->r_ctl.rc_saved_beta.beta;
619 	error = CC_ALGO(tp)->ctl_output(tp->ccv, &sopt, &opt);
620 	if (error)  {
621 		printf("Error returned by ctl_output %d\n", error);
622 		goto out;
623 	}
624 	/*
625 	 * Hack alert we need to set in our newreno_flags
626 	 * so that Abe behavior is also applied.
627 	 */
628 	((struct newreno *)tp->ccv->cc_data)->newreno_flags |= CC_NEWRENO_BETA_ECN_ENABLED;
629 	opt.name = CC_NEWRENO_BETA_ECN;
630 	opt.val = rack->r_ctl.rc_saved_beta.beta_ecn;
631 	error = CC_ALGO(tp)->ctl_output(tp->ccv, &sopt, &opt);
632 	if (error) {
633 		printf("Error returned by ctl_output %d\n", error);
634 		goto out;
635 	}
636 	/* Save off the original values for restoral */
637 	memcpy(&rack->r_ctl.rc_saved_beta, &old, sizeof(struct newreno));
638 out:
639 	if (rack_verbose_logging && (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF)) {
640 		union tcp_log_stackspecific log;
641 		struct timeval tv;
642 
643 		ptr = ((struct newreno *)tp->ccv->cc_data);
644 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
645 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
646 		if (ptr) {
647 			log.u_bbr.flex1 = ptr->beta;
648 			log.u_bbr.flex2 = ptr->beta_ecn;
649 			log.u_bbr.flex3 = ptr->newreno_flags;
650 		}
651 		log.u_bbr.flex4 = rack->r_ctl.rc_saved_beta.beta;
652 		log.u_bbr.flex5 = rack->r_ctl.rc_saved_beta.beta_ecn;
653 		log.u_bbr.flex6 = rack->r_ctl.rc_saved_beta.newreno_flags;
654 		log.u_bbr.flex7 = rack->gp_ready;
655 		log.u_bbr.flex7 <<= 1;
656 		log.u_bbr.flex7 |= rack->use_fixed_rate;
657 		log.u_bbr.flex7 <<= 1;
658 		log.u_bbr.flex7 |= rack->rc_pacing_cc_set;
659 		log.u_bbr.pkts_out = rack->r_ctl.rc_prr_sndcnt;
660 		log.u_bbr.flex8 = 3;
661 		tcp_log_event_(tp, NULL, NULL, NULL, BBR_LOG_CWND, error,
662 			       0, &log, false, NULL, NULL, 0, &tv);
663 	}
664 }
665 
666 static void
667 rack_undo_cc_pacing(struct tcp_rack *rack)
668 {
669 	struct newreno old, *ptr;
670 	struct tcpcb *tp;
671 
672 	if (rack->rc_pacing_cc_set == 0)
673 		return;
674 	tp = rack->rc_tp;
675 	rack->rc_pacing_cc_set = 0;
676 	if (tp->cc_algo == NULL)
677 		/* Tcb is leaving */
678 		return;
679 	if (strcmp(tp->cc_algo->name, CCALGONAME_NEWRENO) != 0) {
680 		/* Not new-reno nothing to do! */
681 		return;
682 	}
683 	ptr = ((struct newreno *)tp->ccv->cc_data);
684 	if (ptr == NULL) {
685 		/*
686 		 * This happens at rack_fini() if the
687 		 * cc module gets freed on us. In that
688 		 * case we loose our "new" settings but
689 		 * thats ok, since the tcb is going away anyway.
690 		 */
691 		return;
692 	}
693 	/* Grab out our set values */
694 	memcpy(&old, ptr, sizeof(struct newreno));
695 	/* Copy back in the original values */
696 	memcpy(ptr, &rack->r_ctl.rc_saved_beta, sizeof(struct newreno));
697 	/* Now save back the values we had set in (for when pacing is restored) */
698 	memcpy(&rack->r_ctl.rc_saved_beta, &old, sizeof(struct newreno));
699 	if (rack_verbose_logging && (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF)) {
700 		union tcp_log_stackspecific log;
701 		struct timeval tv;
702 
703 		ptr = ((struct newreno *)tp->ccv->cc_data);
704 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
705 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
706 		log.u_bbr.flex1 = ptr->beta;
707 		log.u_bbr.flex2 = ptr->beta_ecn;
708 		log.u_bbr.flex3 = ptr->newreno_flags;
709 		log.u_bbr.flex4 = rack->r_ctl.rc_saved_beta.beta;
710 		log.u_bbr.flex5 = rack->r_ctl.rc_saved_beta.beta_ecn;
711 		log.u_bbr.flex6 = rack->r_ctl.rc_saved_beta.newreno_flags;
712 		log.u_bbr.flex7 = rack->gp_ready;
713 		log.u_bbr.flex7 <<= 1;
714 		log.u_bbr.flex7 |= rack->use_fixed_rate;
715 		log.u_bbr.flex7 <<= 1;
716 		log.u_bbr.flex7 |= rack->rc_pacing_cc_set;
717 		log.u_bbr.pkts_out = rack->r_ctl.rc_prr_sndcnt;
718 		log.u_bbr.flex8 = 4;
719 		tcp_log_event_(tp, NULL, NULL, NULL, BBR_LOG_CWND, 0,
720 			       0, &log, false, NULL, NULL, 0, &tv);
721 	}
722 }
723 
724 #ifdef NETFLIX_PEAKRATE
725 static inline void
726 rack_update_peakrate_thr(struct tcpcb *tp)
727 {
728 	/* Keep in mind that t_maxpeakrate is in B/s. */
729 	uint64_t peak;
730 	peak = uqmax((tp->t_maxseg * 2),
731 		     (((uint64_t)tp->t_maxpeakrate * (uint64_t)(tp->t_srtt)) / (uint64_t)HPTS_USEC_IN_SEC));
732 	tp->t_peakrate_thr = (uint32_t)uqmin(peak, UINT32_MAX);
733 }
734 #endif
735 
736 static int
737 sysctl_rack_clear(SYSCTL_HANDLER_ARGS)
738 {
739 	uint32_t stat;
740 	int32_t error;
741 	int i;
742 
743 	error = SYSCTL_OUT(req, &rack_clear_counter, sizeof(uint32_t));
744 	if (error || req->newptr == NULL)
745 		return error;
746 
747 	error = SYSCTL_IN(req, &stat, sizeof(uint32_t));
748 	if (error)
749 		return (error);
750 	if (stat == 1) {
751 #ifdef INVARIANTS
752 		printf("Clearing RACK counters\n");
753 #endif
754 		counter_u64_zero(rack_badfr);
755 		counter_u64_zero(rack_badfr_bytes);
756 		counter_u64_zero(rack_rtm_prr_retran);
757 		counter_u64_zero(rack_rtm_prr_newdata);
758 		counter_u64_zero(rack_timestamp_mismatch);
759 		counter_u64_zero(rack_reorder_seen);
760 		counter_u64_zero(rack_tlp_tot);
761 		counter_u64_zero(rack_tlp_newdata);
762 		counter_u64_zero(rack_tlp_retran);
763 		counter_u64_zero(rack_tlp_retran_bytes);
764 		counter_u64_zero(rack_tlp_retran_fail);
765 		counter_u64_zero(rack_to_tot);
766 		counter_u64_zero(rack_to_arm_rack);
767 		counter_u64_zero(rack_to_arm_tlp);
768 		counter_u64_zero(rack_paced_segments);
769 		counter_u64_zero(rack_calc_zero);
770 		counter_u64_zero(rack_calc_nonzero);
771 		counter_u64_zero(rack_unpaced_segments);
772 		counter_u64_zero(rack_saw_enobuf);
773 		counter_u64_zero(rack_saw_enobuf_hw);
774 		counter_u64_zero(rack_saw_enetunreach);
775 		counter_u64_zero(rack_per_timer_hole);
776 		counter_u64_zero(rack_large_ackcmp);
777 		counter_u64_zero(rack_small_ackcmp);
778 #ifdef INVARIANTS
779 		counter_u64_zero(rack_adjust_map_bw);
780 #endif
781 		counter_u64_zero(rack_to_alloc_hard);
782 		counter_u64_zero(rack_to_alloc_emerg);
783 		counter_u64_zero(rack_sack_proc_all);
784 		counter_u64_zero(rack_fto_send);
785 		counter_u64_zero(rack_fto_rsm_send);
786 		counter_u64_zero(rack_extended_rfo);
787 		counter_u64_zero(rack_hw_pace_init_fail);
788 		counter_u64_zero(rack_hw_pace_lost);
789 		counter_u64_zero(rack_sbsndptr_wrong);
790 		counter_u64_zero(rack_sbsndptr_right);
791 		counter_u64_zero(rack_non_fto_send);
792 		counter_u64_zero(rack_nfto_resend);
793 		counter_u64_zero(rack_sack_proc_short);
794 		counter_u64_zero(rack_sack_proc_restart);
795 		counter_u64_zero(rack_to_alloc);
796 		counter_u64_zero(rack_to_alloc_limited);
797 		counter_u64_zero(rack_alloc_limited_conns);
798 		counter_u64_zero(rack_split_limited);
799 		for (i = 0; i < MAX_NUM_OF_CNTS; i++) {
800 			counter_u64_zero(rack_proc_comp_ack[i]);
801 		}
802 		counter_u64_zero(rack_multi_single_eq);
803 		counter_u64_zero(rack_proc_non_comp_ack);
804 		counter_u64_zero(rack_find_high);
805 		counter_u64_zero(rack_sack_attacks_detected);
806 		counter_u64_zero(rack_sack_attacks_reversed);
807 		counter_u64_zero(rack_sack_used_next_merge);
808 		counter_u64_zero(rack_sack_used_prev_merge);
809 		counter_u64_zero(rack_sack_splits);
810 		counter_u64_zero(rack_sack_skipped_acked);
811 		counter_u64_zero(rack_ack_total);
812 		counter_u64_zero(rack_express_sack);
813 		counter_u64_zero(rack_sack_total);
814 		counter_u64_zero(rack_move_none);
815 		counter_u64_zero(rack_move_some);
816 		counter_u64_zero(rack_used_tlpmethod);
817 		counter_u64_zero(rack_used_tlpmethod2);
818 		counter_u64_zero(rack_enter_tlp_calc);
819 		counter_u64_zero(rack_progress_drops);
820 		counter_u64_zero(rack_tlp_does_nada);
821 		counter_u64_zero(rack_try_scwnd);
822 		counter_u64_zero(rack_collapsed_win);
823 	}
824 	rack_clear_counter = 0;
825 	return (0);
826 }
827 
828 static void
829 rack_init_sysctls(void)
830 {
831 	int i;
832 	struct sysctl_oid *rack_counters;
833 	struct sysctl_oid *rack_attack;
834 	struct sysctl_oid *rack_pacing;
835 	struct sysctl_oid *rack_timely;
836 	struct sysctl_oid *rack_timers;
837 	struct sysctl_oid *rack_tlp;
838 	struct sysctl_oid *rack_misc;
839 	struct sysctl_oid *rack_features;
840 	struct sysctl_oid *rack_measure;
841 	struct sysctl_oid *rack_probertt;
842 	struct sysctl_oid *rack_hw_pacing;
843 
844 	rack_attack = SYSCTL_ADD_NODE(&rack_sysctl_ctx,
845 	    SYSCTL_CHILDREN(rack_sysctl_root),
846 	    OID_AUTO,
847 	    "sack_attack",
848 	    CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
849 	    "Rack Sack Attack Counters and Controls");
850 	rack_counters = SYSCTL_ADD_NODE(&rack_sysctl_ctx,
851 	    SYSCTL_CHILDREN(rack_sysctl_root),
852 	    OID_AUTO,
853 	    "stats",
854 	    CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
855 	    "Rack Counters");
856 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
857 	    SYSCTL_CHILDREN(rack_sysctl_root),
858 	    OID_AUTO, "rate_sample_method", CTLFLAG_RW,
859 	    &rack_rate_sample_method , USE_RTT_LOW,
860 	    "What method should we use for rate sampling 0=high, 1=low ");
861 	/* Probe rtt related controls */
862 	rack_probertt = SYSCTL_ADD_NODE(&rack_sysctl_ctx,
863 	    SYSCTL_CHILDREN(rack_sysctl_root),
864 	    OID_AUTO,
865 	    "probertt",
866 	    CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
867 	    "ProbeRTT related Controls");
868 	SYSCTL_ADD_U16(&rack_sysctl_ctx,
869 	    SYSCTL_CHILDREN(rack_probertt),
870 	    OID_AUTO, "exit_per_hpb", CTLFLAG_RW,
871 	    &rack_atexit_prtt_hbp, 130,
872 	    "What percentage above goodput do we clamp CA/SS to at exit on high-BDP path 110%");
873 	SYSCTL_ADD_U16(&rack_sysctl_ctx,
874 	    SYSCTL_CHILDREN(rack_probertt),
875 	    OID_AUTO, "exit_per_nonhpb", CTLFLAG_RW,
876 	    &rack_atexit_prtt, 130,
877 	    "What percentage above goodput do we clamp CA/SS to at exit on a non high-BDP path 100%");
878 	SYSCTL_ADD_U16(&rack_sysctl_ctx,
879 	    SYSCTL_CHILDREN(rack_probertt),
880 	    OID_AUTO, "gp_per_mul", CTLFLAG_RW,
881 	    &rack_per_of_gp_probertt, 60,
882 	    "What percentage of goodput do we pace at in probertt");
883 	SYSCTL_ADD_U16(&rack_sysctl_ctx,
884 	    SYSCTL_CHILDREN(rack_probertt),
885 	    OID_AUTO, "gp_per_reduce", CTLFLAG_RW,
886 	    &rack_per_of_gp_probertt_reduce, 10,
887 	    "What percentage of goodput do we reduce every gp_srtt");
888 	SYSCTL_ADD_U16(&rack_sysctl_ctx,
889 	    SYSCTL_CHILDREN(rack_probertt),
890 	    OID_AUTO, "gp_per_low", CTLFLAG_RW,
891 	    &rack_per_of_gp_lowthresh, 40,
892 	    "What percentage of goodput do we allow the multiplier to fall to");
893 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
894 	    SYSCTL_CHILDREN(rack_probertt),
895 	    OID_AUTO, "time_between", CTLFLAG_RW,
896 	    & rack_time_between_probertt, 96000000,
897 	    "How many useconds between the lowest rtt falling must past before we enter probertt");
898 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
899 	    SYSCTL_CHILDREN(rack_probertt),
900 	    OID_AUTO, "safety", CTLFLAG_RW,
901 	    &rack_probe_rtt_safety_val, 2000000,
902 	    "If not zero, provides a maximum usecond that you can stay in probertt (2sec = 2000000)");
903 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
904 	    SYSCTL_CHILDREN(rack_probertt),
905 	    OID_AUTO, "sets_cwnd", CTLFLAG_RW,
906 	    &rack_probe_rtt_sets_cwnd, 0,
907 	    "Do we set the cwnd too (if always_lower is on)");
908 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
909 	    SYSCTL_CHILDREN(rack_probertt),
910 	    OID_AUTO, "maxdrainsrtts", CTLFLAG_RW,
911 	    &rack_max_drain_wait, 2,
912 	    "Maximum number of gp_srtt's to hold in drain waiting for flight to reach goal");
913 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
914 	    SYSCTL_CHILDREN(rack_probertt),
915 	    OID_AUTO, "mustdrainsrtts", CTLFLAG_RW,
916 	    &rack_must_drain, 1,
917 	    "We must drain this many gp_srtt's waiting for flight to reach goal");
918 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
919 	    SYSCTL_CHILDREN(rack_probertt),
920 	    OID_AUTO, "goal_use_min_entry", CTLFLAG_RW,
921 	    &rack_probertt_use_min_rtt_entry, 1,
922 	    "Should we use the min-rtt to calculate the goal rtt (else gp_srtt) at entry");
923 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
924 	    SYSCTL_CHILDREN(rack_probertt),
925 	    OID_AUTO, "goal_use_min_exit", CTLFLAG_RW,
926 	    &rack_probertt_use_min_rtt_exit, 0,
927 	    "How to set cwnd at exit, 0 - dynamic, 1 - use min-rtt, 2 - use curgprtt, 3 - entry gp-rtt");
928 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
929 	    SYSCTL_CHILDREN(rack_probertt),
930 	    OID_AUTO, "length_div", CTLFLAG_RW,
931 	    &rack_probertt_gpsrtt_cnt_div, 0,
932 	    "How many recent goodput srtt periods plus hold tim does probertt last (bottom of fraction)");
933 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
934 	    SYSCTL_CHILDREN(rack_probertt),
935 	    OID_AUTO, "length_mul", CTLFLAG_RW,
936 	    &rack_probertt_gpsrtt_cnt_mul, 0,
937 	    "How many recent goodput srtt periods plus hold tim does probertt last (top of fraction)");
938 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
939 	    SYSCTL_CHILDREN(rack_probertt),
940 	    OID_AUTO, "holdtim_at_target", CTLFLAG_RW,
941 	    &rack_min_probertt_hold, 200000,
942 	    "What is the minimum time we hold probertt at target");
943 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
944 	    SYSCTL_CHILDREN(rack_probertt),
945 	    OID_AUTO, "filter_life", CTLFLAG_RW,
946 	    &rack_probertt_filter_life, 10000000,
947 	    "What is the time for the filters life in useconds");
948 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
949 	    SYSCTL_CHILDREN(rack_probertt),
950 	    OID_AUTO, "lower_within", CTLFLAG_RW,
951 	    &rack_probertt_lower_within, 10,
952 	    "If the rtt goes lower within this percentage of the time, go into probe-rtt");
953 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
954 	    SYSCTL_CHILDREN(rack_probertt),
955 	    OID_AUTO, "must_move", CTLFLAG_RW,
956 	    &rack_min_rtt_movement, 250,
957 	    "How much is the minimum movement in rtt to count as a drop for probertt purposes");
958 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
959 	    SYSCTL_CHILDREN(rack_probertt),
960 	    OID_AUTO, "clear_is_cnts", CTLFLAG_RW,
961 	    &rack_probertt_clear_is, 1,
962 	    "Do we clear I/S counts on exiting probe-rtt");
963 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
964 	    SYSCTL_CHILDREN(rack_probertt),
965 	    OID_AUTO, "hbp_extra_drain", CTLFLAG_RW,
966 	    &rack_max_drain_hbp, 1,
967 	    "How many extra drain gpsrtt's do we get in highly buffered paths");
968 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
969 	    SYSCTL_CHILDREN(rack_probertt),
970 	    OID_AUTO, "hbp_threshold", CTLFLAG_RW,
971 	    &rack_hbp_thresh, 3,
972 	    "We are highly buffered if min_rtt_seen / max_rtt_seen > this-threshold");
973 	/* Pacing related sysctls */
974 	rack_pacing = SYSCTL_ADD_NODE(&rack_sysctl_ctx,
975 	    SYSCTL_CHILDREN(rack_sysctl_root),
976 	    OID_AUTO,
977 	    "pacing",
978 	    CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
979 	    "Pacing related Controls");
980 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
981 	    SYSCTL_CHILDREN(rack_pacing),
982 	    OID_AUTO, "max_pace_over", CTLFLAG_RW,
983 	    &rack_max_per_above, 30,
984 	    "What is the maximum allowable percentage that we can pace above (so 30 = 130% of our goal)");
985 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
986 	    SYSCTL_CHILDREN(rack_pacing),
987 	    OID_AUTO, "pace_to_one", CTLFLAG_RW,
988 	    &rack_pace_one_seg, 0,
989 	    "Do we allow low b/w pacing of 1MSS instead of two");
990 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
991 	    SYSCTL_CHILDREN(rack_pacing),
992 	    OID_AUTO, "limit_wsrtt", CTLFLAG_RW,
993 	    &rack_limit_time_with_srtt, 0,
994 	    "Do we limit pacing time based on srtt");
995 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
996 	    SYSCTL_CHILDREN(rack_pacing),
997 	    OID_AUTO, "init_win", CTLFLAG_RW,
998 	    &rack_default_init_window, 0,
999 	    "Do we have a rack initial window 0 = system default");
1000 	SYSCTL_ADD_U16(&rack_sysctl_ctx,
1001 	    SYSCTL_CHILDREN(rack_pacing),
1002 	    OID_AUTO, "gp_per_ss", CTLFLAG_RW,
1003 	    &rack_per_of_gp_ss, 250,
1004 	    "If non zero, what percentage of goodput to pace at in slow start");
1005 	SYSCTL_ADD_U16(&rack_sysctl_ctx,
1006 	    SYSCTL_CHILDREN(rack_pacing),
1007 	    OID_AUTO, "gp_per_ca", CTLFLAG_RW,
1008 	    &rack_per_of_gp_ca, 150,
1009 	    "If non zero, what percentage of goodput to pace at in congestion avoidance");
1010 	SYSCTL_ADD_U16(&rack_sysctl_ctx,
1011 	    SYSCTL_CHILDREN(rack_pacing),
1012 	    OID_AUTO, "gp_per_rec", CTLFLAG_RW,
1013 	    &rack_per_of_gp_rec, 200,
1014 	    "If non zero, what percentage of goodput to pace at in recovery");
1015 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1016 	    SYSCTL_CHILDREN(rack_pacing),
1017 	    OID_AUTO, "pace_max_seg", CTLFLAG_RW,
1018 	    &rack_hptsi_segments, 40,
1019 	    "What size is the max for TSO segments in pacing and burst mitigation");
1020 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1021 	    SYSCTL_CHILDREN(rack_pacing),
1022 	    OID_AUTO, "burst_reduces", CTLFLAG_RW,
1023 	    &rack_slot_reduction, 4,
1024 	    "When doing only burst mitigation what is the reduce divisor");
1025 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1026 	    SYSCTL_CHILDREN(rack_sysctl_root),
1027 	    OID_AUTO, "use_pacing", CTLFLAG_RW,
1028 	    &rack_pace_every_seg, 0,
1029 	    "If set we use pacing, if clear we use only the original burst mitigation");
1030 	SYSCTL_ADD_U64(&rack_sysctl_ctx,
1031 	    SYSCTL_CHILDREN(rack_pacing),
1032 	    OID_AUTO, "rate_cap", CTLFLAG_RW,
1033 	    &rack_bw_rate_cap, 0,
1034 	    "If set we apply this value to the absolute rate cap used by pacing");
1035 	SYSCTL_ADD_U8(&rack_sysctl_ctx,
1036 	    SYSCTL_CHILDREN(rack_sysctl_root),
1037 	    OID_AUTO, "req_measure_cnt", CTLFLAG_RW,
1038 	    &rack_req_measurements, 1,
1039 	    "If doing dynamic pacing, how many measurements must be in before we start pacing?");
1040 	/* Hardware pacing */
1041 	rack_hw_pacing = SYSCTL_ADD_NODE(&rack_sysctl_ctx,
1042 	    SYSCTL_CHILDREN(rack_sysctl_root),
1043 	    OID_AUTO,
1044 	    "hdwr_pacing",
1045 	    CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
1046 	    "Pacing related Controls");
1047 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1048 	    SYSCTL_CHILDREN(rack_hw_pacing),
1049 	    OID_AUTO, "rwnd_factor", CTLFLAG_RW,
1050 	    &rack_hw_rwnd_factor, 2,
1051 	    "How many times does snd_wnd need to be bigger than pace_max_seg so we will hold off and get more acks?");
1052 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1053 	    SYSCTL_CHILDREN(rack_hw_pacing),
1054 	    OID_AUTO, "pace_enobuf_mult", CTLFLAG_RW,
1055 	    &rack_enobuf_hw_boost_mult, 2,
1056 	    "By how many time_betweens should we boost the pacing time if we see a ENOBUFS?");
1057 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1058 	    SYSCTL_CHILDREN(rack_hw_pacing),
1059 	    OID_AUTO, "pace_enobuf_max", CTLFLAG_RW,
1060 	    &rack_enobuf_hw_max, 2,
1061 	    "What is the max boost the pacing time if we see a ENOBUFS?");
1062 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1063 	    SYSCTL_CHILDREN(rack_hw_pacing),
1064 	    OID_AUTO, "pace_enobuf_min", CTLFLAG_RW,
1065 	    &rack_enobuf_hw_min, 2,
1066 	    "What is the min boost the pacing time if we see a ENOBUFS?");
1067 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1068 	    SYSCTL_CHILDREN(rack_hw_pacing),
1069 	    OID_AUTO, "enable", CTLFLAG_RW,
1070 	    &rack_enable_hw_pacing, 0,
1071 	    "Should RACK attempt to use hw pacing?");
1072 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1073 	    SYSCTL_CHILDREN(rack_hw_pacing),
1074 	    OID_AUTO, "rate_cap", CTLFLAG_RW,
1075 	    &rack_hw_rate_caps, 1,
1076 	    "Does the highest hardware pacing rate cap the rate we will send at??");
1077 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1078 	    SYSCTL_CHILDREN(rack_hw_pacing),
1079 	    OID_AUTO, "rate_min", CTLFLAG_RW,
1080 	    &rack_hw_rate_min, 0,
1081 	    "Do we need a minimum estimate of this many bytes per second in order to engage hw pacing?");
1082 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1083 	    SYSCTL_CHILDREN(rack_hw_pacing),
1084 	    OID_AUTO, "rate_to_low", CTLFLAG_RW,
1085 	    &rack_hw_rate_to_low, 0,
1086 	    "If we fall below this rate, dis-engage hw pacing?");
1087 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1088 	    SYSCTL_CHILDREN(rack_hw_pacing),
1089 	    OID_AUTO, "up_only", CTLFLAG_RW,
1090 	    &rack_hw_up_only, 1,
1091 	    "Do we allow hw pacing to lower the rate selected?");
1092 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1093 	    SYSCTL_CHILDREN(rack_hw_pacing),
1094 	    OID_AUTO, "extra_mss_precise", CTLFLAG_RW,
1095 	    &rack_hw_pace_extra_slots, 2,
1096 	    "If the rates between software and hardware match precisely how many extra time_betweens do we get?");
1097 	rack_timely = SYSCTL_ADD_NODE(&rack_sysctl_ctx,
1098 	    SYSCTL_CHILDREN(rack_sysctl_root),
1099 	    OID_AUTO,
1100 	    "timely",
1101 	    CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
1102 	    "Rack Timely RTT Controls");
1103 	/* Timely based GP dynmics */
1104 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1105 	    SYSCTL_CHILDREN(rack_timely),
1106 	    OID_AUTO, "upper", CTLFLAG_RW,
1107 	    &rack_gp_per_bw_mul_up, 2,
1108 	    "Rack timely upper range for equal b/w (in percentage)");
1109 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1110 	    SYSCTL_CHILDREN(rack_timely),
1111 	    OID_AUTO, "lower", CTLFLAG_RW,
1112 	    &rack_gp_per_bw_mul_down, 4,
1113 	    "Rack timely lower range for equal b/w (in percentage)");
1114 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1115 	    SYSCTL_CHILDREN(rack_timely),
1116 	    OID_AUTO, "rtt_max_mul", CTLFLAG_RW,
1117 	    &rack_gp_rtt_maxmul, 3,
1118 	    "Rack timely multipler of lowest rtt for rtt_max");
1119 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1120 	    SYSCTL_CHILDREN(rack_timely),
1121 	    OID_AUTO, "rtt_min_div", CTLFLAG_RW,
1122 	    &rack_gp_rtt_mindiv, 4,
1123 	    "Rack timely divisor used for rtt + (rtt * mul/divisor) for check for lower rtt");
1124 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1125 	    SYSCTL_CHILDREN(rack_timely),
1126 	    OID_AUTO, "rtt_min_mul", CTLFLAG_RW,
1127 	    &rack_gp_rtt_minmul, 1,
1128 	    "Rack timely multiplier used for rtt + (rtt * mul/divisor) for check for lower rtt");
1129 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1130 	    SYSCTL_CHILDREN(rack_timely),
1131 	    OID_AUTO, "decrease", CTLFLAG_RW,
1132 	    &rack_gp_decrease_per, 20,
1133 	    "Rack timely decrease percentage of our GP multiplication factor");
1134 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1135 	    SYSCTL_CHILDREN(rack_timely),
1136 	    OID_AUTO, "increase", CTLFLAG_RW,
1137 	    &rack_gp_increase_per, 2,
1138 	    "Rack timely increase perentage of our GP multiplication factor");
1139 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1140 	    SYSCTL_CHILDREN(rack_timely),
1141 	    OID_AUTO, "lowerbound", CTLFLAG_RW,
1142 	    &rack_per_lower_bound, 50,
1143 	    "Rack timely lowest percentage we allow GP multiplier to fall to");
1144 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1145 	    SYSCTL_CHILDREN(rack_timely),
1146 	    OID_AUTO, "upperboundss", CTLFLAG_RW,
1147 	    &rack_per_upper_bound_ss, 0,
1148 	    "Rack timely higest percentage we allow GP multiplier in SS to raise to (0 is no upperbound)");
1149 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1150 	    SYSCTL_CHILDREN(rack_timely),
1151 	    OID_AUTO, "upperboundca", CTLFLAG_RW,
1152 	    &rack_per_upper_bound_ca, 0,
1153 	    "Rack timely higest percentage we allow GP multiplier to CA raise to (0 is no upperbound)");
1154 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1155 	    SYSCTL_CHILDREN(rack_timely),
1156 	    OID_AUTO, "dynamicgp", CTLFLAG_RW,
1157 	    &rack_do_dyn_mul, 0,
1158 	    "Rack timely do we enable dynmaic timely goodput by default");
1159 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1160 	    SYSCTL_CHILDREN(rack_timely),
1161 	    OID_AUTO, "no_rec_red", CTLFLAG_RW,
1162 	    &rack_gp_no_rec_chg, 1,
1163 	    "Rack timely do we prohibit the recovery multiplier from being lowered");
1164 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1165 	    SYSCTL_CHILDREN(rack_timely),
1166 	    OID_AUTO, "red_clear_cnt", CTLFLAG_RW,
1167 	    &rack_timely_dec_clear, 6,
1168 	    "Rack timely what threshold do we count to before another boost during b/w decent");
1169 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1170 	    SYSCTL_CHILDREN(rack_timely),
1171 	    OID_AUTO, "max_push_rise", CTLFLAG_RW,
1172 	    &rack_timely_max_push_rise, 3,
1173 	    "Rack timely how many times do we push up with b/w increase");
1174 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1175 	    SYSCTL_CHILDREN(rack_timely),
1176 	    OID_AUTO, "max_push_drop", CTLFLAG_RW,
1177 	    &rack_timely_max_push_drop, 3,
1178 	    "Rack timely how many times do we push back on b/w decent");
1179 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1180 	    SYSCTL_CHILDREN(rack_timely),
1181 	    OID_AUTO, "min_segs", CTLFLAG_RW,
1182 	    &rack_timely_min_segs, 4,
1183 	    "Rack timely when setting the cwnd what is the min num segments");
1184 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1185 	    SYSCTL_CHILDREN(rack_timely),
1186 	    OID_AUTO, "noback_max", CTLFLAG_RW,
1187 	    &rack_use_max_for_nobackoff, 0,
1188 	    "Rack timely when deciding if to backoff on a loss, do we use under max rtt else min");
1189 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1190 	    SYSCTL_CHILDREN(rack_timely),
1191 	    OID_AUTO, "interim_timely_only", CTLFLAG_RW,
1192 	    &rack_timely_int_timely_only, 0,
1193 	    "Rack timely when doing interim timely's do we only do timely (no b/w consideration)");
1194 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1195 	    SYSCTL_CHILDREN(rack_timely),
1196 	    OID_AUTO, "nonstop", CTLFLAG_RW,
1197 	    &rack_timely_no_stopping, 0,
1198 	    "Rack timely don't stop increase");
1199 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1200 	    SYSCTL_CHILDREN(rack_timely),
1201 	    OID_AUTO, "dec_raise_thresh", CTLFLAG_RW,
1202 	    &rack_down_raise_thresh, 100,
1203 	    "If the CA or SS is below this threshold raise on the first 3 b/w lowers (0=always)");
1204 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1205 	    SYSCTL_CHILDREN(rack_timely),
1206 	    OID_AUTO, "bottom_drag_segs", CTLFLAG_RW,
1207 	    &rack_req_segs, 1,
1208 	    "Bottom dragging if not these many segments outstanding and room");
1209 
1210 	/* TLP and Rack related parameters */
1211 	rack_tlp = SYSCTL_ADD_NODE(&rack_sysctl_ctx,
1212 	    SYSCTL_CHILDREN(rack_sysctl_root),
1213 	    OID_AUTO,
1214 	    "tlp",
1215 	    CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
1216 	    "TLP and Rack related Controls");
1217 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1218 	    SYSCTL_CHILDREN(rack_tlp),
1219 	    OID_AUTO, "use_rrr", CTLFLAG_RW,
1220 	    &use_rack_rr, 1,
1221 	    "Do we use Rack Rapid Recovery");
1222 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1223 	    SYSCTL_CHILDREN(rack_tlp),
1224 	    OID_AUTO, "post_rec_labc", CTLFLAG_RW,
1225 	    &rack_max_abc_post_recovery, 2,
1226 	    "Since we do early recovery, do we override the l_abc to a value, if so what?");
1227 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1228 	    SYSCTL_CHILDREN(rack_tlp),
1229 	    OID_AUTO, "nonrxt_use_cr", CTLFLAG_RW,
1230 	    &rack_non_rxt_use_cr, 0,
1231 	    "Do we use ss/ca rate if in recovery we are transmitting a new data chunk");
1232 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1233 	    SYSCTL_CHILDREN(rack_tlp),
1234 	    OID_AUTO, "tlpmethod", CTLFLAG_RW,
1235 	    &rack_tlp_threshold_use, TLP_USE_TWO_ONE,
1236 	    "What method do we do for TLP time calc 0=no-de-ack-comp, 1=ID, 2=2.1, 3=2.2");
1237 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1238 	    SYSCTL_CHILDREN(rack_tlp),
1239 	    OID_AUTO, "limit", CTLFLAG_RW,
1240 	    &rack_tlp_limit, 2,
1241 	    "How many TLP's can be sent without sending new data");
1242 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1243 	    SYSCTL_CHILDREN(rack_tlp),
1244 	    OID_AUTO, "use_greater", CTLFLAG_RW,
1245 	    &rack_tlp_use_greater, 1,
1246 	    "Should we use the rack_rtt time if its greater than srtt");
1247 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1248 	    SYSCTL_CHILDREN(rack_tlp),
1249 	    OID_AUTO, "tlpminto", CTLFLAG_RW,
1250 	    &rack_tlp_min, 10000,
1251 	    "TLP minimum timeout per the specification (in microseconds)");
1252 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1253 	    SYSCTL_CHILDREN(rack_tlp),
1254 	    OID_AUTO, "send_oldest", CTLFLAG_RW,
1255 	    &rack_always_send_oldest, 0,
1256 	    "Should we always send the oldest TLP and RACK-TLP");
1257 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1258 	    SYSCTL_CHILDREN(rack_tlp),
1259 	    OID_AUTO, "rack_tlimit", CTLFLAG_RW,
1260 	    &rack_limited_retran, 0,
1261 	    "How many times can a rack timeout drive out sends");
1262 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1263 	    SYSCTL_CHILDREN(rack_tlp),
1264 	    OID_AUTO, "tlp_cwnd_flag", CTLFLAG_RW,
1265 	    &rack_lower_cwnd_at_tlp, 0,
1266 	    "When a TLP completes a retran should we enter recovery");
1267 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1268 	    SYSCTL_CHILDREN(rack_tlp),
1269 	    OID_AUTO, "reorder_thresh", CTLFLAG_RW,
1270 	    &rack_reorder_thresh, 2,
1271 	    "What factor for rack will be added when seeing reordering (shift right)");
1272 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1273 	    SYSCTL_CHILDREN(rack_tlp),
1274 	    OID_AUTO, "rtt_tlp_thresh", CTLFLAG_RW,
1275 	    &rack_tlp_thresh, 1,
1276 	    "What divisor for TLP rtt/retran will be added (1=rtt, 2=1/2 rtt etc)");
1277 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1278 	    SYSCTL_CHILDREN(rack_tlp),
1279 	    OID_AUTO, "reorder_fade", CTLFLAG_RW,
1280 	    &rack_reorder_fade, 60000000,
1281 	    "Does reorder detection fade, if so how many microseconds (0 means never)");
1282 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1283 	    SYSCTL_CHILDREN(rack_tlp),
1284 	    OID_AUTO, "pktdelay", CTLFLAG_RW,
1285 	    &rack_pkt_delay, 1000,
1286 	    "Extra RACK time (in microseconds) besides reordering thresh");
1287 
1288 	/* Timer related controls */
1289 	rack_timers = SYSCTL_ADD_NODE(&rack_sysctl_ctx,
1290 	    SYSCTL_CHILDREN(rack_sysctl_root),
1291 	    OID_AUTO,
1292 	    "timers",
1293 	    CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
1294 	    "Timer related controls");
1295 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
1296 	    SYSCTL_CHILDREN(rack_timers),
1297 	    OID_AUTO, "persmin", CTLFLAG_RW,
1298 	    &rack_persist_min, 250000,
1299 	    "What is the minimum time in microseconds between persists");
1300 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
1301 	    SYSCTL_CHILDREN(rack_timers),
1302 	    OID_AUTO, "persmax", CTLFLAG_RW,
1303 	    &rack_persist_max, 2000000,
1304 	    "What is the largest delay in microseconds between persists");
1305 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1306 	    SYSCTL_CHILDREN(rack_timers),
1307 	    OID_AUTO, "delayed_ack", CTLFLAG_RW,
1308 	    &rack_delayed_ack_time, 40000,
1309 	    "Delayed ack time (40ms in microseconds)");
1310 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1311 	    SYSCTL_CHILDREN(rack_timers),
1312 	    OID_AUTO, "minrto", CTLFLAG_RW,
1313 	    &rack_rto_min, 30000,
1314 	    "Minimum RTO in microseconds -- set with caution below 1000 due to TLP");
1315 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1316 	    SYSCTL_CHILDREN(rack_timers),
1317 	    OID_AUTO, "maxrto", CTLFLAG_RW,
1318 	    &rack_rto_max, 4000000,
1319 	    "Maximum RTO in microseconds -- should be at least as large as min_rto");
1320 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1321 	    SYSCTL_CHILDREN(rack_timers),
1322 	    OID_AUTO, "minto", CTLFLAG_RW,
1323 	    &rack_min_to, 1000,
1324 	    "Minimum rack timeout in microseconds");
1325 	/* Measure controls */
1326 	rack_measure = SYSCTL_ADD_NODE(&rack_sysctl_ctx,
1327 	    SYSCTL_CHILDREN(rack_sysctl_root),
1328 	    OID_AUTO,
1329 	    "measure",
1330 	    CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
1331 	    "Measure related controls");
1332 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1333 	    SYSCTL_CHILDREN(rack_measure),
1334 	    OID_AUTO, "wma_divisor", CTLFLAG_RW,
1335 	    &rack_wma_divisor, 8,
1336 	    "When doing b/w calculation what is the  divisor for the WMA");
1337 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1338 	    SYSCTL_CHILDREN(rack_measure),
1339 	    OID_AUTO, "end_cwnd", CTLFLAG_RW,
1340 	    &rack_cwnd_block_ends_measure, 0,
1341 	    "Does a cwnd just-return end the measurement window (app limited)");
1342 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1343 	    SYSCTL_CHILDREN(rack_measure),
1344 	    OID_AUTO, "end_rwnd", CTLFLAG_RW,
1345 	    &rack_rwnd_block_ends_measure, 0,
1346 	    "Does an rwnd just-return end the measurement window (app limited -- not persists)");
1347 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
1348 	    SYSCTL_CHILDREN(rack_measure),
1349 	    OID_AUTO, "min_target", CTLFLAG_RW,
1350 	    &rack_def_data_window, 20,
1351 	    "What is the minimum target window (in mss) for a GP measurements");
1352 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
1353 	    SYSCTL_CHILDREN(rack_measure),
1354 	    OID_AUTO, "goal_bdp", CTLFLAG_RW,
1355 	    &rack_goal_bdp, 2,
1356 	    "What is the goal BDP to measure");
1357 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
1358 	    SYSCTL_CHILDREN(rack_measure),
1359 	    OID_AUTO, "min_srtts", CTLFLAG_RW,
1360 	    &rack_min_srtts, 1,
1361 	    "What is the goal BDP to measure");
1362 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
1363 	    SYSCTL_CHILDREN(rack_measure),
1364 	    OID_AUTO, "min_measure_tim", CTLFLAG_RW,
1365 	    &rack_min_measure_usec, 0,
1366 	    "What is the Minimum time time for a measurement if 0, this is off");
1367 	/* Features */
1368 	rack_features = SYSCTL_ADD_NODE(&rack_sysctl_ctx,
1369 	    SYSCTL_CHILDREN(rack_sysctl_root),
1370 	    OID_AUTO,
1371 	    "features",
1372 	    CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
1373 	    "Feature controls");
1374 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1375 	    SYSCTL_CHILDREN(rack_features),
1376 	    OID_AUTO, "cmpack", CTLFLAG_RW,
1377 	    &rack_use_cmp_acks, 1,
1378 	    "Should RACK have LRO send compressed acks");
1379 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1380 	    SYSCTL_CHILDREN(rack_features),
1381 	    OID_AUTO, "fsb", CTLFLAG_RW,
1382 	    &rack_use_fsb, 1,
1383 	    "Should RACK use the fast send block?");
1384 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1385 	    SYSCTL_CHILDREN(rack_features),
1386 	    OID_AUTO, "rfo", CTLFLAG_RW,
1387 	    &rack_use_rfo, 1,
1388 	    "Should RACK use rack_fast_output()?");
1389 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1390 	    SYSCTL_CHILDREN(rack_features),
1391 	    OID_AUTO, "rsmrfo", CTLFLAG_RW,
1392 	    &rack_use_rsm_rfo, 1,
1393 	    "Should RACK use rack_fast_rsm_output()?");
1394 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1395 	    SYSCTL_CHILDREN(rack_features),
1396 	    OID_AUTO, "non_paced_lro_queue", CTLFLAG_RW,
1397 	    &rack_enable_mqueue_for_nonpaced, 0,
1398 	    "Should RACK use mbuf queuing for non-paced connections");
1399 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1400 	    SYSCTL_CHILDREN(rack_features),
1401 	    OID_AUTO, "hystartplusplus", CTLFLAG_RW,
1402 	    &rack_do_hystart, 0,
1403 	    "Should RACK enable HyStart++ on connections?");
1404 	/* Misc rack controls */
1405 	rack_misc = SYSCTL_ADD_NODE(&rack_sysctl_ctx,
1406 	    SYSCTL_CHILDREN(rack_sysctl_root),
1407 	    OID_AUTO,
1408 	    "misc",
1409 	    CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
1410 	    "Misc related controls");
1411 #ifdef TCP_ACCOUNTING
1412 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1413 	    SYSCTL_CHILDREN(rack_misc),
1414 	    OID_AUTO, "tcp_acct", CTLFLAG_RW,
1415 	    &rack_tcp_accounting, 0,
1416 	    "Should we turn on TCP accounting for all rack sessions?");
1417 #endif
1418 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1419 	    SYSCTL_CHILDREN(rack_misc),
1420 	    OID_AUTO, "rack_dsack_ctl", CTLFLAG_RW,
1421 	    &rack_dsack_std_based, 3,
1422 	    "How do we process dsack with respect to rack timers, bit field, 3 is standards based?");
1423 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1424 	    SYSCTL_CHILDREN(rack_misc),
1425 	    OID_AUTO, "prr_addback_max", CTLFLAG_RW,
1426 	    &rack_prr_addbackmax, 2,
1427 	    "What is the maximum number of MSS we allow to be added back if prr can't send all its data?");
1428 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1429 	    SYSCTL_CHILDREN(rack_misc),
1430 	    OID_AUTO, "stats_gets_ms", CTLFLAG_RW,
1431 	    &rack_stats_gets_ms_rtt, 1,
1432 	    "What do we feed the stats framework (1 = ms_rtt, 0 = us_rtt, 2 = ms_rtt from hdwr, > 2 usec rtt from hdwr)?");
1433 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1434 	    SYSCTL_CHILDREN(rack_misc),
1435 	    OID_AUTO, "clientlowbuf", CTLFLAG_RW,
1436 	    &rack_client_low_buf, 0,
1437 	    "Client low buffer level (below this we are more aggressive in DGP exiting recovery (0 = off)?");
1438 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1439 	    SYSCTL_CHILDREN(rack_misc),
1440 	    OID_AUTO, "defprofile", CTLFLAG_RW,
1441 	    &rack_def_profile, 0,
1442 	    "Should RACK use a default profile (0=no, num == profile num)?");
1443 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1444 	    SYSCTL_CHILDREN(rack_misc),
1445 	    OID_AUTO, "shared_cwnd", CTLFLAG_RW,
1446 	    &rack_enable_shared_cwnd, 1,
1447 	    "Should RACK try to use the shared cwnd on connections where allowed");
1448 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1449 	    SYSCTL_CHILDREN(rack_misc),
1450 	    OID_AUTO, "limits_on_scwnd", CTLFLAG_RW,
1451 	    &rack_limits_scwnd, 1,
1452 	    "Should RACK place low end time limits on the shared cwnd feature");
1453 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1454 	    SYSCTL_CHILDREN(rack_misc),
1455 	    OID_AUTO, "iMac_dack", CTLFLAG_RW,
1456 	    &rack_use_imac_dack, 0,
1457 	    "Should RACK try to emulate iMac delayed ack");
1458 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1459 	    SYSCTL_CHILDREN(rack_misc),
1460 	    OID_AUTO, "no_prr", CTLFLAG_RW,
1461 	    &rack_disable_prr, 0,
1462 	    "Should RACK not use prr and only pace (must have pacing on)");
1463 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1464 	    SYSCTL_CHILDREN(rack_misc),
1465 	    OID_AUTO, "bb_verbose", CTLFLAG_RW,
1466 	    &rack_verbose_logging, 0,
1467 	    "Should RACK black box logging be verbose");
1468 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1469 	    SYSCTL_CHILDREN(rack_misc),
1470 	    OID_AUTO, "data_after_close", CTLFLAG_RW,
1471 	    &rack_ignore_data_after_close, 1,
1472 	    "Do we hold off sending a RST until all pending data is ack'd");
1473 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1474 	    SYSCTL_CHILDREN(rack_misc),
1475 	    OID_AUTO, "no_sack_needed", CTLFLAG_RW,
1476 	    &rack_sack_not_required, 1,
1477 	    "Do we allow rack to run on connections not supporting SACK");
1478 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1479 	    SYSCTL_CHILDREN(rack_misc),
1480 	    OID_AUTO, "prr_sendalot", CTLFLAG_RW,
1481 	    &rack_send_a_lot_in_prr, 1,
1482 	    "Send a lot in prr");
1483 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1484 	    SYSCTL_CHILDREN(rack_misc),
1485 	    OID_AUTO, "autoscale", CTLFLAG_RW,
1486 	    &rack_autosndbuf_inc, 20,
1487 	    "What percentage should rack scale up its snd buffer by?");
1488 	/* Sack Attacker detection stuff */
1489 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
1490 	    SYSCTL_CHILDREN(rack_attack),
1491 	    OID_AUTO, "detect_highsackratio", CTLFLAG_RW,
1492 	    &rack_highest_sack_thresh_seen, 0,
1493 	    "Highest sack to ack ratio seen");
1494 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
1495 	    SYSCTL_CHILDREN(rack_attack),
1496 	    OID_AUTO, "detect_highmoveratio", CTLFLAG_RW,
1497 	    &rack_highest_move_thresh_seen, 0,
1498 	    "Highest move to non-move ratio seen");
1499 	rack_ack_total = counter_u64_alloc(M_WAITOK);
1500 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1501 	    SYSCTL_CHILDREN(rack_attack),
1502 	    OID_AUTO, "acktotal", CTLFLAG_RD,
1503 	    &rack_ack_total,
1504 	    "Total number of Ack's");
1505 	rack_express_sack = counter_u64_alloc(M_WAITOK);
1506 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1507 	    SYSCTL_CHILDREN(rack_attack),
1508 	    OID_AUTO, "exp_sacktotal", CTLFLAG_RD,
1509 	    &rack_express_sack,
1510 	    "Total expresss number of Sack's");
1511 	rack_sack_total = counter_u64_alloc(M_WAITOK);
1512 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1513 	    SYSCTL_CHILDREN(rack_attack),
1514 	    OID_AUTO, "sacktotal", CTLFLAG_RD,
1515 	    &rack_sack_total,
1516 	    "Total number of SACKs");
1517 	rack_move_none = counter_u64_alloc(M_WAITOK);
1518 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1519 	    SYSCTL_CHILDREN(rack_attack),
1520 	    OID_AUTO, "move_none", CTLFLAG_RD,
1521 	    &rack_move_none,
1522 	    "Total number of SACK index reuse of postions under threshold");
1523 	rack_move_some = counter_u64_alloc(M_WAITOK);
1524 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1525 	    SYSCTL_CHILDREN(rack_attack),
1526 	    OID_AUTO, "move_some", CTLFLAG_RD,
1527 	    &rack_move_some,
1528 	    "Total number of SACK index reuse of postions over threshold");
1529 	rack_sack_attacks_detected = counter_u64_alloc(M_WAITOK);
1530 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1531 	    SYSCTL_CHILDREN(rack_attack),
1532 	    OID_AUTO, "attacks", CTLFLAG_RD,
1533 	    &rack_sack_attacks_detected,
1534 	    "Total number of SACK attackers that had sack disabled");
1535 	rack_sack_attacks_reversed = counter_u64_alloc(M_WAITOK);
1536 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1537 	    SYSCTL_CHILDREN(rack_attack),
1538 	    OID_AUTO, "reversed", CTLFLAG_RD,
1539 	    &rack_sack_attacks_reversed,
1540 	    "Total number of SACK attackers that were later determined false positive");
1541 	rack_sack_used_next_merge = counter_u64_alloc(M_WAITOK);
1542 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1543 	    SYSCTL_CHILDREN(rack_attack),
1544 	    OID_AUTO, "nextmerge", CTLFLAG_RD,
1545 	    &rack_sack_used_next_merge,
1546 	    "Total number of times we used the next merge");
1547 	rack_sack_used_prev_merge = counter_u64_alloc(M_WAITOK);
1548 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1549 	    SYSCTL_CHILDREN(rack_attack),
1550 	    OID_AUTO, "prevmerge", CTLFLAG_RD,
1551 	    &rack_sack_used_prev_merge,
1552 	    "Total number of times we used the prev merge");
1553 	/* Counters */
1554 	rack_fto_send = counter_u64_alloc(M_WAITOK);
1555 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1556 	    SYSCTL_CHILDREN(rack_counters),
1557 	    OID_AUTO, "fto_send", CTLFLAG_RD,
1558 	    &rack_fto_send, "Total number of rack_fast_output sends");
1559 	rack_fto_rsm_send = counter_u64_alloc(M_WAITOK);
1560 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1561 	    SYSCTL_CHILDREN(rack_counters),
1562 	    OID_AUTO, "fto_rsm_send", CTLFLAG_RD,
1563 	    &rack_fto_rsm_send, "Total number of rack_fast_rsm_output sends");
1564 	rack_nfto_resend = counter_u64_alloc(M_WAITOK);
1565 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1566 	    SYSCTL_CHILDREN(rack_counters),
1567 	    OID_AUTO, "nfto_resend", CTLFLAG_RD,
1568 	    &rack_nfto_resend, "Total number of rack_output retransmissions");
1569 	rack_non_fto_send = counter_u64_alloc(M_WAITOK);
1570 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1571 	    SYSCTL_CHILDREN(rack_counters),
1572 	    OID_AUTO, "nfto_send", CTLFLAG_RD,
1573 	    &rack_non_fto_send, "Total number of rack_output first sends");
1574 	rack_extended_rfo = counter_u64_alloc(M_WAITOK);
1575 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1576 	    SYSCTL_CHILDREN(rack_counters),
1577 	    OID_AUTO, "rfo_extended", CTLFLAG_RD,
1578 	    &rack_extended_rfo, "Total number of times we extended rfo");
1579 
1580 	rack_hw_pace_init_fail = counter_u64_alloc(M_WAITOK);
1581 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1582 	    SYSCTL_CHILDREN(rack_counters),
1583 	    OID_AUTO, "hwpace_init_fail", CTLFLAG_RD,
1584 	    &rack_hw_pace_init_fail, "Total number of times we failed to initialize hw pacing");
1585 	rack_hw_pace_lost = counter_u64_alloc(M_WAITOK);
1586 
1587 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1588 	    SYSCTL_CHILDREN(rack_counters),
1589 	    OID_AUTO, "hwpace_lost", CTLFLAG_RD,
1590 	    &rack_hw_pace_lost, "Total number of times we failed to initialize hw pacing");
1591 	rack_badfr = counter_u64_alloc(M_WAITOK);
1592 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1593 	    SYSCTL_CHILDREN(rack_counters),
1594 	    OID_AUTO, "badfr", CTLFLAG_RD,
1595 	    &rack_badfr, "Total number of bad FRs");
1596 	rack_badfr_bytes = counter_u64_alloc(M_WAITOK);
1597 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1598 	    SYSCTL_CHILDREN(rack_counters),
1599 	    OID_AUTO, "badfr_bytes", CTLFLAG_RD,
1600 	    &rack_badfr_bytes, "Total number of bad FRs");
1601 	rack_rtm_prr_retran = counter_u64_alloc(M_WAITOK);
1602 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1603 	    SYSCTL_CHILDREN(rack_counters),
1604 	    OID_AUTO, "prrsndret", CTLFLAG_RD,
1605 	    &rack_rtm_prr_retran,
1606 	    "Total number of prr based retransmits");
1607 	rack_rtm_prr_newdata = counter_u64_alloc(M_WAITOK);
1608 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1609 	    SYSCTL_CHILDREN(rack_counters),
1610 	    OID_AUTO, "prrsndnew", CTLFLAG_RD,
1611 	    &rack_rtm_prr_newdata,
1612 	    "Total number of prr based new transmits");
1613 	rack_timestamp_mismatch = counter_u64_alloc(M_WAITOK);
1614 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1615 	    SYSCTL_CHILDREN(rack_counters),
1616 	    OID_AUTO, "tsnf", CTLFLAG_RD,
1617 	    &rack_timestamp_mismatch,
1618 	    "Total number of timestamps that we could not find the reported ts");
1619 	rack_find_high = counter_u64_alloc(M_WAITOK);
1620 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1621 	    SYSCTL_CHILDREN(rack_counters),
1622 	    OID_AUTO, "findhigh", CTLFLAG_RD,
1623 	    &rack_find_high,
1624 	    "Total number of FIN causing find-high");
1625 	rack_reorder_seen = counter_u64_alloc(M_WAITOK);
1626 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1627 	    SYSCTL_CHILDREN(rack_counters),
1628 	    OID_AUTO, "reordering", CTLFLAG_RD,
1629 	    &rack_reorder_seen,
1630 	    "Total number of times we added delay due to reordering");
1631 	rack_tlp_tot = counter_u64_alloc(M_WAITOK);
1632 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1633 	    SYSCTL_CHILDREN(rack_counters),
1634 	    OID_AUTO, "tlp_to_total", CTLFLAG_RD,
1635 	    &rack_tlp_tot,
1636 	    "Total number of tail loss probe expirations");
1637 	rack_tlp_newdata = counter_u64_alloc(M_WAITOK);
1638 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1639 	    SYSCTL_CHILDREN(rack_counters),
1640 	    OID_AUTO, "tlp_new", CTLFLAG_RD,
1641 	    &rack_tlp_newdata,
1642 	    "Total number of tail loss probe sending new data");
1643 	rack_tlp_retran = counter_u64_alloc(M_WAITOK);
1644 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1645 	    SYSCTL_CHILDREN(rack_counters),
1646 	    OID_AUTO, "tlp_retran", CTLFLAG_RD,
1647 	    &rack_tlp_retran,
1648 	    "Total number of tail loss probe sending retransmitted data");
1649 	rack_tlp_retran_bytes = counter_u64_alloc(M_WAITOK);
1650 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1651 	    SYSCTL_CHILDREN(rack_counters),
1652 	    OID_AUTO, "tlp_retran_bytes", CTLFLAG_RD,
1653 	    &rack_tlp_retran_bytes,
1654 	    "Total bytes of tail loss probe sending retransmitted data");
1655 	rack_tlp_retran_fail = counter_u64_alloc(M_WAITOK);
1656 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1657 	    SYSCTL_CHILDREN(rack_counters),
1658 	    OID_AUTO, "tlp_retran_fail", CTLFLAG_RD,
1659 	    &rack_tlp_retran_fail,
1660 	    "Total number of tail loss probe sending retransmitted data that failed (wait for t3)");
1661 	rack_to_tot = counter_u64_alloc(M_WAITOK);
1662 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1663 	    SYSCTL_CHILDREN(rack_counters),
1664 	    OID_AUTO, "rack_to_tot", CTLFLAG_RD,
1665 	    &rack_to_tot,
1666 	    "Total number of times the rack to expired");
1667 	rack_to_arm_rack = counter_u64_alloc(M_WAITOK);
1668 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1669 	    SYSCTL_CHILDREN(rack_counters),
1670 	    OID_AUTO, "arm_rack", CTLFLAG_RD,
1671 	    &rack_to_arm_rack,
1672 	    "Total number of times the rack timer armed");
1673 	rack_to_arm_tlp = counter_u64_alloc(M_WAITOK);
1674 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1675 	    SYSCTL_CHILDREN(rack_counters),
1676 	    OID_AUTO, "arm_tlp", CTLFLAG_RD,
1677 	    &rack_to_arm_tlp,
1678 	    "Total number of times the tlp timer armed");
1679 	rack_calc_zero = counter_u64_alloc(M_WAITOK);
1680 	rack_calc_nonzero = counter_u64_alloc(M_WAITOK);
1681 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1682 	    SYSCTL_CHILDREN(rack_counters),
1683 	    OID_AUTO, "calc_zero", CTLFLAG_RD,
1684 	    &rack_calc_zero,
1685 	    "Total number of times pacing time worked out to zero");
1686 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1687 	    SYSCTL_CHILDREN(rack_counters),
1688 	    OID_AUTO, "calc_nonzero", CTLFLAG_RD,
1689 	    &rack_calc_nonzero,
1690 	    "Total number of times pacing time worked out to non-zero");
1691 	rack_paced_segments = counter_u64_alloc(M_WAITOK);
1692 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1693 	    SYSCTL_CHILDREN(rack_counters),
1694 	    OID_AUTO, "paced", CTLFLAG_RD,
1695 	    &rack_paced_segments,
1696 	    "Total number of times a segment send caused hptsi");
1697 	rack_unpaced_segments = counter_u64_alloc(M_WAITOK);
1698 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1699 	    SYSCTL_CHILDREN(rack_counters),
1700 	    OID_AUTO, "unpaced", CTLFLAG_RD,
1701 	    &rack_unpaced_segments,
1702 	    "Total number of times a segment did not cause hptsi");
1703 	rack_saw_enobuf = counter_u64_alloc(M_WAITOK);
1704 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1705 	    SYSCTL_CHILDREN(rack_counters),
1706 	    OID_AUTO, "saw_enobufs", CTLFLAG_RD,
1707 	    &rack_saw_enobuf,
1708 	    "Total number of times a sends returned enobuf for non-hdwr paced connections");
1709 	rack_saw_enobuf_hw = counter_u64_alloc(M_WAITOK);
1710 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1711 	    SYSCTL_CHILDREN(rack_counters),
1712 	    OID_AUTO, "saw_enobufs_hw", CTLFLAG_RD,
1713 	    &rack_saw_enobuf_hw,
1714 	    "Total number of times a send returned enobuf for hdwr paced connections");
1715 	rack_saw_enetunreach = counter_u64_alloc(M_WAITOK);
1716 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1717 	    SYSCTL_CHILDREN(rack_counters),
1718 	    OID_AUTO, "saw_enetunreach", CTLFLAG_RD,
1719 	    &rack_saw_enetunreach,
1720 	    "Total number of times a send received a enetunreachable");
1721 	rack_hot_alloc = counter_u64_alloc(M_WAITOK);
1722 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1723 	    SYSCTL_CHILDREN(rack_counters),
1724 	    OID_AUTO, "alloc_hot", CTLFLAG_RD,
1725 	    &rack_hot_alloc,
1726 	    "Total allocations from the top of our list");
1727 	rack_to_alloc = counter_u64_alloc(M_WAITOK);
1728 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1729 	    SYSCTL_CHILDREN(rack_counters),
1730 	    OID_AUTO, "allocs", CTLFLAG_RD,
1731 	    &rack_to_alloc,
1732 	    "Total allocations of tracking structures");
1733 	rack_to_alloc_hard = counter_u64_alloc(M_WAITOK);
1734 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1735 	    SYSCTL_CHILDREN(rack_counters),
1736 	    OID_AUTO, "allochard", CTLFLAG_RD,
1737 	    &rack_to_alloc_hard,
1738 	    "Total allocations done with sleeping the hard way");
1739 	rack_to_alloc_emerg = counter_u64_alloc(M_WAITOK);
1740 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1741 	    SYSCTL_CHILDREN(rack_counters),
1742 	    OID_AUTO, "allocemerg", CTLFLAG_RD,
1743 	    &rack_to_alloc_emerg,
1744 	    "Total allocations done from emergency cache");
1745 	rack_to_alloc_limited = counter_u64_alloc(M_WAITOK);
1746 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1747 	    SYSCTL_CHILDREN(rack_counters),
1748 	    OID_AUTO, "alloc_limited", CTLFLAG_RD,
1749 	    &rack_to_alloc_limited,
1750 	    "Total allocations dropped due to limit");
1751 	rack_alloc_limited_conns = counter_u64_alloc(M_WAITOK);
1752 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1753 	    SYSCTL_CHILDREN(rack_counters),
1754 	    OID_AUTO, "alloc_limited_conns", CTLFLAG_RD,
1755 	    &rack_alloc_limited_conns,
1756 	    "Connections with allocations dropped due to limit");
1757 	rack_split_limited = counter_u64_alloc(M_WAITOK);
1758 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1759 	    SYSCTL_CHILDREN(rack_counters),
1760 	    OID_AUTO, "split_limited", CTLFLAG_RD,
1761 	    &rack_split_limited,
1762 	    "Split allocations dropped due to limit");
1763 
1764 	for (i = 0; i < MAX_NUM_OF_CNTS; i++) {
1765 		char name[32];
1766 		sprintf(name, "cmp_ack_cnt_%d", i);
1767 		rack_proc_comp_ack[i] = counter_u64_alloc(M_WAITOK);
1768 		SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1769 				       SYSCTL_CHILDREN(rack_counters),
1770 				       OID_AUTO, name, CTLFLAG_RD,
1771 				       &rack_proc_comp_ack[i],
1772 				       "Number of compressed acks we processed");
1773 	}
1774 	rack_large_ackcmp = counter_u64_alloc(M_WAITOK);
1775 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1776 	    SYSCTL_CHILDREN(rack_counters),
1777 	    OID_AUTO, "cmp_large_mbufs", CTLFLAG_RD,
1778 	    &rack_large_ackcmp,
1779 	    "Number of TCP connections with large mbuf's for compressed acks");
1780 	rack_small_ackcmp = counter_u64_alloc(M_WAITOK);
1781 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1782 	    SYSCTL_CHILDREN(rack_counters),
1783 	    OID_AUTO, "cmp_small_mbufs", CTLFLAG_RD,
1784 	    &rack_small_ackcmp,
1785 	    "Number of TCP connections with small mbuf's for compressed acks");
1786 #ifdef INVARIANTS
1787 	rack_adjust_map_bw = counter_u64_alloc(M_WAITOK);
1788 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1789 	    SYSCTL_CHILDREN(rack_counters),
1790 	    OID_AUTO, "map_adjust_req", CTLFLAG_RD,
1791 	    &rack_adjust_map_bw,
1792 	    "Number of times we hit the case where the sb went up and down on a sendmap entry");
1793 #endif
1794 	rack_multi_single_eq = counter_u64_alloc(M_WAITOK);
1795 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1796 	    SYSCTL_CHILDREN(rack_counters),
1797 	    OID_AUTO, "cmp_ack_equiv", CTLFLAG_RD,
1798 	    &rack_multi_single_eq,
1799 	    "Number of compressed acks total represented");
1800 	rack_proc_non_comp_ack = counter_u64_alloc(M_WAITOK);
1801 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1802 	    SYSCTL_CHILDREN(rack_counters),
1803 	    OID_AUTO, "cmp_ack_not", CTLFLAG_RD,
1804 	    &rack_proc_non_comp_ack,
1805 	    "Number of non compresseds acks that we processed");
1806 
1807 
1808 	rack_sack_proc_all = counter_u64_alloc(M_WAITOK);
1809 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1810 	    SYSCTL_CHILDREN(rack_counters),
1811 	    OID_AUTO, "sack_long", CTLFLAG_RD,
1812 	    &rack_sack_proc_all,
1813 	    "Total times we had to walk whole list for sack processing");
1814 	rack_sack_proc_restart = counter_u64_alloc(M_WAITOK);
1815 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1816 	    SYSCTL_CHILDREN(rack_counters),
1817 	    OID_AUTO, "sack_restart", CTLFLAG_RD,
1818 	    &rack_sack_proc_restart,
1819 	    "Total times we had to walk whole list due to a restart");
1820 	rack_sack_proc_short = counter_u64_alloc(M_WAITOK);
1821 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1822 	    SYSCTL_CHILDREN(rack_counters),
1823 	    OID_AUTO, "sack_short", CTLFLAG_RD,
1824 	    &rack_sack_proc_short,
1825 	    "Total times we took shortcut for sack processing");
1826 	rack_enter_tlp_calc = counter_u64_alloc(M_WAITOK);
1827 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1828 	    SYSCTL_CHILDREN(rack_counters),
1829 	    OID_AUTO, "tlp_calc_entered", CTLFLAG_RD,
1830 	    &rack_enter_tlp_calc,
1831 	    "Total times we called calc-tlp");
1832 	rack_used_tlpmethod = counter_u64_alloc(M_WAITOK);
1833 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1834 	    SYSCTL_CHILDREN(rack_counters),
1835 	    OID_AUTO, "hit_tlp_method", CTLFLAG_RD,
1836 	    &rack_used_tlpmethod,
1837 	    "Total number of runt sacks");
1838 	rack_used_tlpmethod2 = counter_u64_alloc(M_WAITOK);
1839 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1840 	    SYSCTL_CHILDREN(rack_counters),
1841 	    OID_AUTO, "hit_tlp_method2", CTLFLAG_RD,
1842 	    &rack_used_tlpmethod2,
1843 	    "Total number of times we hit TLP method 2");
1844 	rack_sack_skipped_acked = counter_u64_alloc(M_WAITOK);
1845 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1846 	    SYSCTL_CHILDREN(rack_attack),
1847 	    OID_AUTO, "skipacked", CTLFLAG_RD,
1848 	    &rack_sack_skipped_acked,
1849 	    "Total number of times we skipped previously sacked");
1850 	rack_sack_splits = counter_u64_alloc(M_WAITOK);
1851 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1852 	    SYSCTL_CHILDREN(rack_attack),
1853 	    OID_AUTO, "ofsplit", CTLFLAG_RD,
1854 	    &rack_sack_splits,
1855 	    "Total number of times we did the old fashion tree split");
1856 	rack_progress_drops = counter_u64_alloc(M_WAITOK);
1857 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1858 	    SYSCTL_CHILDREN(rack_counters),
1859 	    OID_AUTO, "prog_drops", CTLFLAG_RD,
1860 	    &rack_progress_drops,
1861 	    "Total number of progress drops");
1862 	rack_input_idle_reduces = counter_u64_alloc(M_WAITOK);
1863 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1864 	    SYSCTL_CHILDREN(rack_counters),
1865 	    OID_AUTO, "idle_reduce_oninput", CTLFLAG_RD,
1866 	    &rack_input_idle_reduces,
1867 	    "Total number of idle reductions on input");
1868 	rack_collapsed_win = counter_u64_alloc(M_WAITOK);
1869 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1870 	    SYSCTL_CHILDREN(rack_counters),
1871 	    OID_AUTO, "collapsed_win", CTLFLAG_RD,
1872 	    &rack_collapsed_win,
1873 	    "Total number of collapsed windows");
1874 	rack_tlp_does_nada = counter_u64_alloc(M_WAITOK);
1875 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1876 	    SYSCTL_CHILDREN(rack_counters),
1877 	    OID_AUTO, "tlp_nada", CTLFLAG_RD,
1878 	    &rack_tlp_does_nada,
1879 	    "Total number of nada tlp calls");
1880 	rack_try_scwnd = counter_u64_alloc(M_WAITOK);
1881 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1882 	    SYSCTL_CHILDREN(rack_counters),
1883 	    OID_AUTO, "tried_scwnd", CTLFLAG_RD,
1884 	    &rack_try_scwnd,
1885 	    "Total number of scwnd attempts");
1886 
1887 	rack_per_timer_hole = counter_u64_alloc(M_WAITOK);
1888 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1889 	    SYSCTL_CHILDREN(rack_counters),
1890 	    OID_AUTO, "timer_hole", CTLFLAG_RD,
1891 	    &rack_per_timer_hole,
1892 	    "Total persists start in timer hole");
1893 
1894 	rack_sbsndptr_wrong = counter_u64_alloc(M_WAITOK);
1895 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1896 	    SYSCTL_CHILDREN(rack_counters),
1897 	    OID_AUTO, "sndptr_wrong", CTLFLAG_RD,
1898 	    &rack_sbsndptr_wrong, "Total number of times the saved sbsndptr was incorret");
1899 	rack_sbsndptr_right = counter_u64_alloc(M_WAITOK);
1900 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1901 	    SYSCTL_CHILDREN(rack_counters),
1902 	    OID_AUTO, "sndptr_right", CTLFLAG_RD,
1903 	    &rack_sbsndptr_right, "Total number of times the saved sbsndptr was corret");
1904 
1905 	COUNTER_ARRAY_ALLOC(rack_out_size, TCP_MSS_ACCT_SIZE, M_WAITOK);
1906 	SYSCTL_ADD_COUNTER_U64_ARRAY(&rack_sysctl_ctx, SYSCTL_CHILDREN(rack_sysctl_root),
1907 	    OID_AUTO, "outsize", CTLFLAG_RD,
1908 	    rack_out_size, TCP_MSS_ACCT_SIZE, "MSS send sizes");
1909 	COUNTER_ARRAY_ALLOC(rack_opts_arry, RACK_OPTS_SIZE, M_WAITOK);
1910 	SYSCTL_ADD_COUNTER_U64_ARRAY(&rack_sysctl_ctx, SYSCTL_CHILDREN(rack_sysctl_root),
1911 	    OID_AUTO, "opts", CTLFLAG_RD,
1912 	    rack_opts_arry, RACK_OPTS_SIZE, "RACK Option Stats");
1913 	SYSCTL_ADD_PROC(&rack_sysctl_ctx,
1914 	    SYSCTL_CHILDREN(rack_sysctl_root),
1915 	    OID_AUTO, "clear", CTLTYPE_UINT | CTLFLAG_RW | CTLFLAG_MPSAFE,
1916 	    &rack_clear_counter, 0, sysctl_rack_clear, "IU", "Clear counters");
1917 }
1918 
1919 static __inline int
1920 rb_map_cmp(struct rack_sendmap *b, struct rack_sendmap *a)
1921 {
1922 	if (SEQ_GEQ(b->r_start, a->r_start) &&
1923 	    SEQ_LT(b->r_start, a->r_end)) {
1924 		/*
1925 		 * The entry b is within the
1926 		 * block a. i.e.:
1927 		 * a --   |-------------|
1928 		 * b --   |----|
1929 		 * <or>
1930 		 * b --       |------|
1931 		 * <or>
1932 		 * b --       |-----------|
1933 		 */
1934 		return (0);
1935 	} else if (SEQ_GEQ(b->r_start, a->r_end)) {
1936 		/*
1937 		 * b falls as either the next
1938 		 * sequence block after a so a
1939 		 * is said to be smaller than b.
1940 		 * i.e:
1941 		 * a --   |------|
1942 		 * b --          |--------|
1943 		 * or
1944 		 * b --              |-----|
1945 		 */
1946 		return (1);
1947 	}
1948 	/*
1949 	 * Whats left is where a is
1950 	 * larger than b. i.e:
1951 	 * a --         |-------|
1952 	 * b --  |---|
1953 	 * or even possibly
1954 	 * b --   |--------------|
1955 	 */
1956 	return (-1);
1957 }
1958 
1959 RB_PROTOTYPE(rack_rb_tree_head, rack_sendmap, r_next, rb_map_cmp);
1960 RB_GENERATE(rack_rb_tree_head, rack_sendmap, r_next, rb_map_cmp);
1961 
1962 static uint32_t
1963 rc_init_window(struct tcp_rack *rack)
1964 {
1965 	uint32_t win;
1966 
1967 	if (rack->rc_init_win == 0) {
1968 		/*
1969 		 * Nothing set by the user, use the system stack
1970 		 * default.
1971 		 */
1972 		return (tcp_compute_initwnd(tcp_maxseg(rack->rc_tp)));
1973 	}
1974 	win = ctf_fixed_maxseg(rack->rc_tp) * rack->rc_init_win;
1975 	return (win);
1976 }
1977 
1978 static uint64_t
1979 rack_get_fixed_pacing_bw(struct tcp_rack *rack)
1980 {
1981 	if (IN_FASTRECOVERY(rack->rc_tp->t_flags))
1982 		return (rack->r_ctl.rc_fixed_pacing_rate_rec);
1983 	else if (rack->r_ctl.cwnd_to_use < rack->rc_tp->snd_ssthresh)
1984 		return (rack->r_ctl.rc_fixed_pacing_rate_ss);
1985 	else
1986 		return (rack->r_ctl.rc_fixed_pacing_rate_ca);
1987 }
1988 
1989 static uint64_t
1990 rack_get_bw(struct tcp_rack *rack)
1991 {
1992 	if (rack->use_fixed_rate) {
1993 		/* Return the fixed pacing rate */
1994 		return (rack_get_fixed_pacing_bw(rack));
1995 	}
1996 	if (rack->r_ctl.gp_bw == 0) {
1997 		/*
1998 		 * We have yet no b/w measurement,
1999 		 * if we have a user set initial bw
2000 		 * return it. If we don't have that and
2001 		 * we have an srtt, use the tcp IW (10) to
2002 		 * calculate a fictional b/w over the SRTT
2003 		 * which is more or less a guess. Note
2004 		 * we don't use our IW from rack on purpose
2005 		 * so if we have like IW=30, we are not
2006 		 * calculating a "huge" b/w.
2007 		 */
2008 		uint64_t bw, srtt;
2009 		if (rack->r_ctl.init_rate)
2010 			return (rack->r_ctl.init_rate);
2011 
2012 		/* Has the user set a max peak rate? */
2013 #ifdef NETFLIX_PEAKRATE
2014 		if (rack->rc_tp->t_maxpeakrate)
2015 			return (rack->rc_tp->t_maxpeakrate);
2016 #endif
2017 		/* Ok lets come up with the IW guess, if we have a srtt */
2018 		if (rack->rc_tp->t_srtt == 0) {
2019 			/*
2020 			 * Go with old pacing method
2021 			 * i.e. burst mitigation only.
2022 			 */
2023 			return (0);
2024 		}
2025 		/* Ok lets get the initial TCP win (not racks) */
2026 		bw = tcp_compute_initwnd(tcp_maxseg(rack->rc_tp));
2027 		srtt = (uint64_t)rack->rc_tp->t_srtt;
2028 		bw *= (uint64_t)USECS_IN_SECOND;
2029 		bw /= srtt;
2030 		if (rack->r_ctl.bw_rate_cap && (bw > rack->r_ctl.bw_rate_cap))
2031 			bw = rack->r_ctl.bw_rate_cap;
2032 		return (bw);
2033 	} else {
2034 		uint64_t bw;
2035 
2036 		if (rack->r_ctl.num_measurements >= RACK_REQ_AVG) {
2037 			/* Averaging is done, we can return the value */
2038 			bw = rack->r_ctl.gp_bw;
2039 		} else {
2040 			/* Still doing initial average must calculate */
2041 			bw = rack->r_ctl.gp_bw / rack->r_ctl.num_measurements;
2042 		}
2043 #ifdef NETFLIX_PEAKRATE
2044 		if ((rack->rc_tp->t_maxpeakrate) &&
2045 		    (bw > rack->rc_tp->t_maxpeakrate)) {
2046 			/* The user has set a peak rate to pace at
2047 			 * don't allow us to pace faster than that.
2048 			 */
2049 			return (rack->rc_tp->t_maxpeakrate);
2050 		}
2051 #endif
2052 		if (rack->r_ctl.bw_rate_cap && (bw > rack->r_ctl.bw_rate_cap))
2053 			bw = rack->r_ctl.bw_rate_cap;
2054 		return (bw);
2055 	}
2056 }
2057 
2058 static uint16_t
2059 rack_get_output_gain(struct tcp_rack *rack, struct rack_sendmap *rsm)
2060 {
2061 	if (rack->use_fixed_rate) {
2062 		return (100);
2063 	} else if (rack->in_probe_rtt && (rsm == NULL))
2064 		return (rack->r_ctl.rack_per_of_gp_probertt);
2065 	else if ((IN_FASTRECOVERY(rack->rc_tp->t_flags) &&
2066 		  rack->r_ctl.rack_per_of_gp_rec)) {
2067 		if (rsm) {
2068 			/* a retransmission always use the recovery rate */
2069 			return (rack->r_ctl.rack_per_of_gp_rec);
2070 		} else if (rack->rack_rec_nonrxt_use_cr) {
2071 			/* Directed to use the configured rate */
2072 			goto configured_rate;
2073 		} else if (rack->rack_no_prr &&
2074 			   (rack->r_ctl.rack_per_of_gp_rec > 100)) {
2075 			/* No PRR, lets just use the b/w estimate only */
2076 			return (100);
2077 		} else {
2078 			/*
2079 			 * Here we may have a non-retransmit but we
2080 			 * have no overrides, so just use the recovery
2081 			 * rate (prr is in effect).
2082 			 */
2083 			return (rack->r_ctl.rack_per_of_gp_rec);
2084 		}
2085 	}
2086 configured_rate:
2087 	/* For the configured rate we look at our cwnd vs the ssthresh */
2088 	if (rack->r_ctl.cwnd_to_use < rack->rc_tp->snd_ssthresh)
2089 		return (rack->r_ctl.rack_per_of_gp_ss);
2090 	else
2091 		return (rack->r_ctl.rack_per_of_gp_ca);
2092 }
2093 
2094 static void
2095 rack_log_dsack_event(struct tcp_rack *rack, uint8_t mod, uint32_t flex4, uint32_t flex5, uint32_t flex6)
2096 {
2097 	/*
2098 	 * Types of logs (mod value)
2099 	 * 1 = dsack_persists reduced by 1 via T-O or fast recovery exit.
2100 	 * 2 = a dsack round begins, persist is reset to 16.
2101 	 * 3 = a dsack round ends
2102 	 * 4 = Dsack option increases rack rtt flex5 is the srtt input, flex6 is thresh
2103 	 * 5 = Socket option set changing the control flags rc_rack_tmr_std_based, rc_rack_use_dsack
2104 	 * 6 = Final rack rtt, flex4 is srtt and flex6 is final limited thresh.
2105 	 */
2106 	if (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
2107 		union tcp_log_stackspecific log;
2108 		struct timeval tv;
2109 
2110 		memset(&log, 0, sizeof(log));
2111 		log.u_bbr.flex1 = rack->rc_rack_tmr_std_based;
2112 		log.u_bbr.flex1 <<= 1;
2113 		log.u_bbr.flex1 |= rack->rc_rack_use_dsack;
2114 		log.u_bbr.flex1 <<= 1;
2115 		log.u_bbr.flex1 |= rack->rc_dsack_round_seen;
2116 		log.u_bbr.flex2 = rack->r_ctl.dsack_round_end;
2117 		log.u_bbr.flex3 = rack->r_ctl.num_dsack;
2118 		log.u_bbr.flex4 = flex4;
2119 		log.u_bbr.flex5 = flex5;
2120 		log.u_bbr.flex6 = flex6;
2121 		log.u_bbr.flex7 = rack->r_ctl.dsack_persist;
2122 		log.u_bbr.flex8 = mod;
2123 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
2124 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
2125 		    &rack->rc_inp->inp_socket->so_rcv,
2126 		    &rack->rc_inp->inp_socket->so_snd,
2127 		    RACK_DSACK_HANDLING, 0,
2128 		    0, &log, false, &tv);
2129 	}
2130 }
2131 
2132 static void
2133 rack_log_hdwr_pacing(struct tcp_rack *rack,
2134 		     uint64_t rate, uint64_t hw_rate, int line,
2135 		     int error, uint16_t mod)
2136 {
2137 	if (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
2138 		union tcp_log_stackspecific log;
2139 		struct timeval tv;
2140 		const struct ifnet *ifp;
2141 
2142 		memset(&log, 0, sizeof(log));
2143 		log.u_bbr.flex1 = ((hw_rate >> 32) & 0x00000000ffffffff);
2144 		log.u_bbr.flex2 = (hw_rate & 0x00000000ffffffff);
2145 		if (rack->r_ctl.crte) {
2146 			ifp = rack->r_ctl.crte->ptbl->rs_ifp;
2147 		} else if (rack->rc_inp->inp_route.ro_nh &&
2148 			   rack->rc_inp->inp_route.ro_nh->nh_ifp) {
2149 			ifp = rack->rc_inp->inp_route.ro_nh->nh_ifp;
2150 		} else
2151 			ifp = NULL;
2152 		if (ifp) {
2153 			log.u_bbr.flex3 = (((uint64_t)ifp  >> 32) & 0x00000000ffffffff);
2154 			log.u_bbr.flex4 = ((uint64_t)ifp & 0x00000000ffffffff);
2155 		}
2156 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
2157 		log.u_bbr.bw_inuse = rate;
2158 		log.u_bbr.flex5 = line;
2159 		log.u_bbr.flex6 = error;
2160 		log.u_bbr.flex7 = mod;
2161 		log.u_bbr.applimited = rack->r_ctl.rc_pace_max_segs;
2162 		log.u_bbr.flex8 = rack->use_fixed_rate;
2163 		log.u_bbr.flex8 <<= 1;
2164 		log.u_bbr.flex8 |= rack->rack_hdrw_pacing;
2165 		log.u_bbr.pkts_out = rack->rc_tp->t_maxseg;
2166 		log.u_bbr.delRate = rack->r_ctl.crte_prev_rate;
2167 		if (rack->r_ctl.crte)
2168 			log.u_bbr.cur_del_rate = rack->r_ctl.crte->rate;
2169 		else
2170 			log.u_bbr.cur_del_rate = 0;
2171 		log.u_bbr.rttProp = rack->r_ctl.last_hw_bw_req;
2172 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
2173 		    &rack->rc_inp->inp_socket->so_rcv,
2174 		    &rack->rc_inp->inp_socket->so_snd,
2175 		    BBR_LOG_HDWR_PACE, 0,
2176 		    0, &log, false, &tv);
2177 	}
2178 }
2179 
2180 static uint64_t
2181 rack_get_output_bw(struct tcp_rack *rack, uint64_t bw, struct rack_sendmap *rsm, int *capped)
2182 {
2183 	/*
2184 	 * We allow rack_per_of_gp_xx to dictate our bw rate we want.
2185 	 */
2186 	uint64_t bw_est, high_rate;
2187 	uint64_t gain;
2188 
2189 	gain = (uint64_t)rack_get_output_gain(rack, rsm);
2190 	bw_est = bw * gain;
2191 	bw_est /= (uint64_t)100;
2192 	/* Never fall below the minimum (def 64kbps) */
2193 	if (bw_est < RACK_MIN_BW)
2194 		bw_est = RACK_MIN_BW;
2195 	if (rack->r_rack_hw_rate_caps) {
2196 		/* Rate caps are in place */
2197 		if (rack->r_ctl.crte != NULL) {
2198 			/* We have a hdwr rate already */
2199 			high_rate = tcp_hw_highest_rate(rack->r_ctl.crte);
2200 			if (bw_est >= high_rate) {
2201 				/* We are capping bw at the highest rate table entry */
2202 				rack_log_hdwr_pacing(rack,
2203 						     bw_est, high_rate, __LINE__,
2204 						     0, 3);
2205 				bw_est = high_rate;
2206 				if (capped)
2207 					*capped = 1;
2208 			}
2209 		} else if ((rack->rack_hdrw_pacing == 0) &&
2210 			   (rack->rack_hdw_pace_ena) &&
2211 			   (rack->rack_attempt_hdwr_pace == 0) &&
2212 			   (rack->rc_inp->inp_route.ro_nh != NULL) &&
2213 			   (rack->rc_inp->inp_route.ro_nh->nh_ifp != NULL)) {
2214 			/*
2215 			 * Special case, we have not yet attempted hardware
2216 			 * pacing, and yet we may, when we do, find out if we are
2217 			 * above the highest rate. We need to know the maxbw for the interface
2218 			 * in question (if it supports ratelimiting). We get back
2219 			 * a 0, if the interface is not found in the RL lists.
2220 			 */
2221 			high_rate = tcp_hw_highest_rate_ifp(rack->rc_inp->inp_route.ro_nh->nh_ifp, rack->rc_inp);
2222 			if (high_rate) {
2223 				/* Yep, we have a rate is it above this rate? */
2224 				if (bw_est > high_rate) {
2225 					bw_est = high_rate;
2226 					if (capped)
2227 						*capped = 1;
2228 				}
2229 			}
2230 		}
2231 	}
2232 	return (bw_est);
2233 }
2234 
2235 static void
2236 rack_log_retran_reason(struct tcp_rack *rack, struct rack_sendmap *rsm, uint32_t tsused, uint32_t thresh, int mod)
2237 {
2238 	if (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
2239 		union tcp_log_stackspecific log;
2240 		struct timeval tv;
2241 
2242 		if ((mod != 1) && (rack_verbose_logging == 0)) {
2243 			/*
2244 			 * We get 3 values currently for mod
2245 			 * 1 - We are retransmitting and this tells the reason.
2246 			 * 2 - We are clearing a dup-ack count.
2247 			 * 3 - We are incrementing a dup-ack count.
2248 			 *
2249 			 * The clear/increment are only logged
2250 			 * if you have BBverbose on.
2251 			 */
2252 			return;
2253 		}
2254 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
2255 		log.u_bbr.flex1 = tsused;
2256 		log.u_bbr.flex2 = thresh;
2257 		log.u_bbr.flex3 = rsm->r_flags;
2258 		log.u_bbr.flex4 = rsm->r_dupack;
2259 		log.u_bbr.flex5 = rsm->r_start;
2260 		log.u_bbr.flex6 = rsm->r_end;
2261 		log.u_bbr.flex8 = mod;
2262 		log.u_bbr.inhpts = rack->rc_inp->inp_in_hpts;
2263 		log.u_bbr.ininput = rack->rc_inp->inp_in_input;
2264 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
2265 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
2266 		log.u_bbr.pkts_out = rack->r_ctl.rc_out_at_rto;
2267 		log.u_bbr.delivered = rack->r_ctl.rc_snd_max_at_rto;
2268 		log.u_bbr.pacing_gain = rack->r_must_retran;
2269 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
2270 		    &rack->rc_inp->inp_socket->so_rcv,
2271 		    &rack->rc_inp->inp_socket->so_snd,
2272 		    BBR_LOG_SETTINGS_CHG, 0,
2273 		    0, &log, false, &tv);
2274 	}
2275 }
2276 
2277 static void
2278 rack_log_to_start(struct tcp_rack *rack, uint32_t cts, uint32_t to, int32_t slot, uint8_t which)
2279 {
2280 	if (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
2281 		union tcp_log_stackspecific log;
2282 		struct timeval tv;
2283 
2284 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
2285 		log.u_bbr.flex1 = rack->rc_tp->t_srtt;
2286 		log.u_bbr.flex2 = to;
2287 		log.u_bbr.flex3 = rack->r_ctl.rc_hpts_flags;
2288 		log.u_bbr.flex4 = slot;
2289 		log.u_bbr.flex5 = rack->rc_inp->inp_hptsslot;
2290 		log.u_bbr.flex6 = rack->rc_tp->t_rxtcur;
2291 		log.u_bbr.flex7 = rack->rc_in_persist;
2292 		log.u_bbr.flex8 = which;
2293 		if (rack->rack_no_prr)
2294 			log.u_bbr.pkts_out = 0;
2295 		else
2296 			log.u_bbr.pkts_out = rack->r_ctl.rc_prr_sndcnt;
2297 		log.u_bbr.inhpts = rack->rc_inp->inp_in_hpts;
2298 		log.u_bbr.ininput = rack->rc_inp->inp_in_input;
2299 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
2300 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
2301 		log.u_bbr.pkts_out = rack->r_ctl.rc_out_at_rto;
2302 		log.u_bbr.delivered = rack->r_ctl.rc_snd_max_at_rto;
2303 		log.u_bbr.pacing_gain = rack->r_must_retran;
2304 		log.u_bbr.lt_epoch = rack->rc_tp->t_rxtshift;
2305 		log.u_bbr.lost = rack_rto_min;
2306 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
2307 		    &rack->rc_inp->inp_socket->so_rcv,
2308 		    &rack->rc_inp->inp_socket->so_snd,
2309 		    BBR_LOG_TIMERSTAR, 0,
2310 		    0, &log, false, &tv);
2311 	}
2312 }
2313 
2314 static void
2315 rack_log_to_event(struct tcp_rack *rack, int32_t to_num, struct rack_sendmap *rsm)
2316 {
2317 	if (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
2318 		union tcp_log_stackspecific log;
2319 		struct timeval tv;
2320 
2321 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
2322 		log.u_bbr.inhpts = rack->rc_inp->inp_in_hpts;
2323 		log.u_bbr.ininput = rack->rc_inp->inp_in_input;
2324 		log.u_bbr.flex8 = to_num;
2325 		log.u_bbr.flex1 = rack->r_ctl.rc_rack_min_rtt;
2326 		log.u_bbr.flex2 = rack->rc_rack_rtt;
2327 		if (rsm == NULL)
2328 			log.u_bbr.flex3 = 0;
2329 		else
2330 			log.u_bbr.flex3 = rsm->r_end - rsm->r_start;
2331 		if (rack->rack_no_prr)
2332 			log.u_bbr.flex5 = 0;
2333 		else
2334 			log.u_bbr.flex5 = rack->r_ctl.rc_prr_sndcnt;
2335 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
2336 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
2337 		log.u_bbr.pkts_out = rack->r_ctl.rc_out_at_rto;
2338 		log.u_bbr.delivered = rack->r_ctl.rc_snd_max_at_rto;
2339 		log.u_bbr.pacing_gain = rack->r_must_retran;
2340 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
2341 		    &rack->rc_inp->inp_socket->so_rcv,
2342 		    &rack->rc_inp->inp_socket->so_snd,
2343 		    BBR_LOG_RTO, 0,
2344 		    0, &log, false, &tv);
2345 	}
2346 }
2347 
2348 static void
2349 rack_log_map_chg(struct tcpcb *tp, struct tcp_rack *rack,
2350 		 struct rack_sendmap *prev,
2351 		 struct rack_sendmap *rsm,
2352 		 struct rack_sendmap *next,
2353 		 int flag, uint32_t th_ack, int line)
2354 {
2355 	if (rack_verbose_logging && (tp->t_logstate != TCP_LOG_STATE_OFF)) {
2356 		union tcp_log_stackspecific log;
2357 		struct timeval tv;
2358 
2359 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
2360 		log.u_bbr.flex8 = flag;
2361 		log.u_bbr.inhpts = rack->rc_inp->inp_in_hpts;
2362 		log.u_bbr.ininput = rack->rc_inp->inp_in_input;
2363 		log.u_bbr.cur_del_rate = (uint64_t)prev;
2364 		log.u_bbr.delRate = (uint64_t)rsm;
2365 		log.u_bbr.rttProp = (uint64_t)next;
2366 		log.u_bbr.flex7 = 0;
2367 		if (prev) {
2368 			log.u_bbr.flex1 = prev->r_start;
2369 			log.u_bbr.flex2 = prev->r_end;
2370 			log.u_bbr.flex7 |= 0x4;
2371 		}
2372 		if (rsm) {
2373 			log.u_bbr.flex3 = rsm->r_start;
2374 			log.u_bbr.flex4 = rsm->r_end;
2375 			log.u_bbr.flex7 |= 0x2;
2376 		}
2377 		if (next) {
2378 			log.u_bbr.flex5 = next->r_start;
2379 			log.u_bbr.flex6 = next->r_end;
2380 			log.u_bbr.flex7 |= 0x1;
2381 		}
2382 		log.u_bbr.applimited = line;
2383 		log.u_bbr.pkts_out = th_ack;
2384 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
2385 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
2386 		if (rack->rack_no_prr)
2387 			log.u_bbr.lost = 0;
2388 		else
2389 			log.u_bbr.lost = rack->r_ctl.rc_prr_sndcnt;
2390 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
2391 		    &rack->rc_inp->inp_socket->so_rcv,
2392 		    &rack->rc_inp->inp_socket->so_snd,
2393 		    TCP_LOG_MAPCHG, 0,
2394 		    0, &log, false, &tv);
2395 	}
2396 }
2397 
2398 static void
2399 rack_log_rtt_upd(struct tcpcb *tp, struct tcp_rack *rack, uint32_t t, uint32_t len,
2400 		 struct rack_sendmap *rsm, int conf)
2401 {
2402 	if (tp->t_logstate != TCP_LOG_STATE_OFF) {
2403 		union tcp_log_stackspecific log;
2404 		struct timeval tv;
2405 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
2406 		log.u_bbr.inhpts = rack->rc_inp->inp_in_hpts;
2407 		log.u_bbr.ininput = rack->rc_inp->inp_in_input;
2408 		log.u_bbr.flex1 = t;
2409 		log.u_bbr.flex2 = len;
2410 		log.u_bbr.flex3 = rack->r_ctl.rc_rack_min_rtt;
2411 		log.u_bbr.flex4 = rack->r_ctl.rack_rs.rs_rtt_lowest;
2412 		log.u_bbr.flex5 = rack->r_ctl.rack_rs.rs_rtt_highest;
2413 		log.u_bbr.flex6 = rack->r_ctl.rack_rs.rs_us_rtrcnt;
2414 		log.u_bbr.flex7 = conf;
2415 		log.u_bbr.rttProp = (uint64_t)rack->r_ctl.rack_rs.rs_rtt_tot;
2416 		log.u_bbr.flex8 = rack->r_ctl.rc_rate_sample_method;
2417 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
2418 		log.u_bbr.delivered = rack->r_ctl.rack_rs.rs_us_rtrcnt;
2419 		log.u_bbr.pkts_out = rack->r_ctl.rack_rs.rs_flags;
2420 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
2421 		if (rsm) {
2422 			log.u_bbr.pkt_epoch = rsm->r_start;
2423 			log.u_bbr.lost = rsm->r_end;
2424 			log.u_bbr.cwnd_gain = rsm->r_rtr_cnt;
2425 			/* We loose any upper of the 24 bits */
2426 			log.u_bbr.pacing_gain = (uint16_t)rsm->r_flags;
2427 		} else {
2428 			/* Its a SYN */
2429 			log.u_bbr.pkt_epoch = rack->rc_tp->iss;
2430 			log.u_bbr.lost = 0;
2431 			log.u_bbr.cwnd_gain = 0;
2432 			log.u_bbr.pacing_gain = 0;
2433 		}
2434 		/* Write out general bits of interest rrs here */
2435 		log.u_bbr.use_lt_bw = rack->rc_highly_buffered;
2436 		log.u_bbr.use_lt_bw <<= 1;
2437 		log.u_bbr.use_lt_bw |= rack->forced_ack;
2438 		log.u_bbr.use_lt_bw <<= 1;
2439 		log.u_bbr.use_lt_bw |= rack->rc_gp_dyn_mul;
2440 		log.u_bbr.use_lt_bw <<= 1;
2441 		log.u_bbr.use_lt_bw |= rack->in_probe_rtt;
2442 		log.u_bbr.use_lt_bw <<= 1;
2443 		log.u_bbr.use_lt_bw |= rack->measure_saw_probe_rtt;
2444 		log.u_bbr.use_lt_bw <<= 1;
2445 		log.u_bbr.use_lt_bw |= rack->app_limited_needs_set;
2446 		log.u_bbr.use_lt_bw <<= 1;
2447 		log.u_bbr.use_lt_bw |= rack->rc_gp_filled;
2448 		log.u_bbr.use_lt_bw <<= 1;
2449 		log.u_bbr.use_lt_bw |= rack->rc_dragged_bottom;
2450 		log.u_bbr.applimited = rack->r_ctl.rc_target_probertt_flight;
2451 		log.u_bbr.epoch = rack->r_ctl.rc_time_probertt_starts;
2452 		log.u_bbr.lt_epoch = rack->r_ctl.rc_time_probertt_entered;
2453 		log.u_bbr.cur_del_rate = rack->r_ctl.rc_lower_rtt_us_cts;
2454 		log.u_bbr.delRate = rack->r_ctl.rc_gp_srtt;
2455 		log.u_bbr.bw_inuse = tcp_tv_to_usectick(&rack->r_ctl.act_rcv_time);
2456 		log.u_bbr.bw_inuse <<= 32;
2457 		if (rsm)
2458 			log.u_bbr.bw_inuse |= ((uint32_t)rsm->r_tim_lastsent[(rsm->r_rtr_cnt-1)]);
2459 		TCP_LOG_EVENTP(tp, NULL,
2460 		    &rack->rc_inp->inp_socket->so_rcv,
2461 		    &rack->rc_inp->inp_socket->so_snd,
2462 		    BBR_LOG_BBRRTT, 0,
2463 		    0, &log, false, &tv);
2464 
2465 
2466 	}
2467 }
2468 
2469 static void
2470 rack_log_rtt_sample(struct tcp_rack *rack, uint32_t rtt)
2471 {
2472 	/*
2473 	 * Log the rtt sample we are
2474 	 * applying to the srtt algorithm in
2475 	 * useconds.
2476 	 */
2477 	if (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
2478 		union tcp_log_stackspecific log;
2479 		struct timeval tv;
2480 
2481 		/* Convert our ms to a microsecond */
2482 		memset(&log, 0, sizeof(log));
2483 		log.u_bbr.flex1 = rtt;
2484 		log.u_bbr.flex2 = rack->r_ctl.ack_count;
2485 		log.u_bbr.flex3 = rack->r_ctl.sack_count;
2486 		log.u_bbr.flex4 = rack->r_ctl.sack_noextra_move;
2487 		log.u_bbr.flex5 = rack->r_ctl.sack_moved_extra;
2488 		log.u_bbr.flex6 = rack->rc_tp->t_rxtcur;
2489 		log.u_bbr.flex7 = 1;
2490 		log.u_bbr.flex8 = rack->sack_attack_disable;
2491 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
2492 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
2493 		log.u_bbr.pkts_out = rack->r_ctl.rc_out_at_rto;
2494 		log.u_bbr.delivered = rack->r_ctl.rc_snd_max_at_rto;
2495 		log.u_bbr.pacing_gain = rack->r_must_retran;
2496 		/*
2497 		 * We capture in delRate the upper 32 bits as
2498 		 * the confidence level we had declared, and the
2499 		 * lower 32 bits as the actual RTT using the arrival
2500 		 * timestamp.
2501 		 */
2502 		log.u_bbr.delRate = rack->r_ctl.rack_rs.confidence;
2503 		log.u_bbr.delRate <<= 32;
2504 		log.u_bbr.delRate |= rack->r_ctl.rack_rs.rs_us_rtt;
2505 		/* Lets capture all the things that make up t_rtxcur */
2506 		log.u_bbr.applimited = rack_rto_min;
2507 		log.u_bbr.epoch = rack_rto_max;
2508 		log.u_bbr.lt_epoch = rack->r_ctl.timer_slop;
2509 		log.u_bbr.lost = rack_rto_min;
2510 		log.u_bbr.pkt_epoch = TICKS_2_USEC(tcp_rexmit_slop);
2511 		log.u_bbr.rttProp = RACK_REXMTVAL(rack->rc_tp);
2512 		log.u_bbr.bw_inuse = rack->r_ctl.act_rcv_time.tv_sec;
2513 		log.u_bbr.bw_inuse *= HPTS_USEC_IN_SEC;
2514 		log.u_bbr.bw_inuse += rack->r_ctl.act_rcv_time.tv_usec;
2515 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
2516 		    &rack->rc_inp->inp_socket->so_rcv,
2517 		    &rack->rc_inp->inp_socket->so_snd,
2518 		    TCP_LOG_RTT, 0,
2519 		    0, &log, false, &tv);
2520 	}
2521 }
2522 
2523 static void
2524 rack_log_rtt_sample_calc(struct tcp_rack *rack, uint32_t rtt, uint32_t send_time, uint32_t ack_time, int where)
2525 {
2526 	if (rack_verbose_logging && (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF)) {
2527 		union tcp_log_stackspecific log;
2528 		struct timeval tv;
2529 
2530 		/* Convert our ms to a microsecond */
2531 		memset(&log, 0, sizeof(log));
2532 		log.u_bbr.flex1 = rtt;
2533 		log.u_bbr.flex2 = send_time;
2534 		log.u_bbr.flex3 = ack_time;
2535 		log.u_bbr.flex4 = where;
2536 		log.u_bbr.flex7 = 2;
2537 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
2538 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
2539 		    &rack->rc_inp->inp_socket->so_rcv,
2540 		    &rack->rc_inp->inp_socket->so_snd,
2541 		    TCP_LOG_RTT, 0,
2542 		    0, &log, false, &tv);
2543 	}
2544 }
2545 
2546 
2547 
2548 static inline void
2549 rack_log_progress_event(struct tcp_rack *rack, struct tcpcb *tp, uint32_t tick,  int event, int line)
2550 {
2551 	if (rack_verbose_logging && (tp->t_logstate != TCP_LOG_STATE_OFF)) {
2552 		union tcp_log_stackspecific log;
2553 		struct timeval tv;
2554 
2555 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
2556 		log.u_bbr.inhpts = rack->rc_inp->inp_in_hpts;
2557 		log.u_bbr.ininput = rack->rc_inp->inp_in_input;
2558 		log.u_bbr.flex1 = line;
2559 		log.u_bbr.flex2 = tick;
2560 		log.u_bbr.flex3 = tp->t_maxunacktime;
2561 		log.u_bbr.flex4 = tp->t_acktime;
2562 		log.u_bbr.flex8 = event;
2563 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
2564 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
2565 		log.u_bbr.pkts_out = rack->r_ctl.rc_out_at_rto;
2566 		log.u_bbr.delivered = rack->r_ctl.rc_snd_max_at_rto;
2567 		log.u_bbr.pacing_gain = rack->r_must_retran;
2568 		TCP_LOG_EVENTP(tp, NULL,
2569 		    &rack->rc_inp->inp_socket->so_rcv,
2570 		    &rack->rc_inp->inp_socket->so_snd,
2571 		    BBR_LOG_PROGRESS, 0,
2572 		    0, &log, false, &tv);
2573 	}
2574 }
2575 
2576 static void
2577 rack_log_type_bbrsnd(struct tcp_rack *rack, uint32_t len, uint32_t slot, uint32_t cts, struct timeval *tv)
2578 {
2579 	if (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
2580 		union tcp_log_stackspecific log;
2581 
2582 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
2583 		log.u_bbr.inhpts = rack->rc_inp->inp_in_hpts;
2584 		log.u_bbr.ininput = rack->rc_inp->inp_in_input;
2585 		log.u_bbr.flex1 = slot;
2586 		if (rack->rack_no_prr)
2587 			log.u_bbr.flex2 = 0;
2588 		else
2589 			log.u_bbr.flex2 = rack->r_ctl.rc_prr_sndcnt;
2590 		log.u_bbr.flex7 = (0x0000ffff & rack->r_ctl.rc_hpts_flags);
2591 		log.u_bbr.flex8 = rack->rc_in_persist;
2592 		log.u_bbr.timeStamp = cts;
2593 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
2594 		log.u_bbr.pkts_out = rack->r_ctl.rc_out_at_rto;
2595 		log.u_bbr.delivered = rack->r_ctl.rc_snd_max_at_rto;
2596 		log.u_bbr.pacing_gain = rack->r_must_retran;
2597 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
2598 		    &rack->rc_inp->inp_socket->so_rcv,
2599 		    &rack->rc_inp->inp_socket->so_snd,
2600 		    BBR_LOG_BBRSND, 0,
2601 		    0, &log, false, tv);
2602 	}
2603 }
2604 
2605 static void
2606 rack_log_doseg_done(struct tcp_rack *rack, uint32_t cts, int32_t nxt_pkt, int32_t did_out, int way_out, int nsegs)
2607 {
2608 	if (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
2609 		union tcp_log_stackspecific log;
2610 		struct timeval tv;
2611 
2612 		memset(&log, 0, sizeof(log));
2613 		log.u_bbr.flex1 = did_out;
2614 		log.u_bbr.flex2 = nxt_pkt;
2615 		log.u_bbr.flex3 = way_out;
2616 		log.u_bbr.flex4 = rack->r_ctl.rc_hpts_flags;
2617 		if (rack->rack_no_prr)
2618 			log.u_bbr.flex5 = 0;
2619 		else
2620 			log.u_bbr.flex5 = rack->r_ctl.rc_prr_sndcnt;
2621 		log.u_bbr.flex6 = nsegs;
2622 		log.u_bbr.applimited = rack->r_ctl.rc_pace_min_segs;
2623 		log.u_bbr.flex7 = rack->rc_ack_can_sendout_data;	/* Do we have ack-can-send set */
2624 		log.u_bbr.flex7 <<= 1;
2625 		log.u_bbr.flex7 |= rack->r_fast_output;	/* is fast output primed */
2626 		log.u_bbr.flex7 <<= 1;
2627 		log.u_bbr.flex7 |= rack->r_wanted_output;	/* Do we want output */
2628 		log.u_bbr.flex8 = rack->rc_in_persist;
2629 		log.u_bbr.inhpts = rack->rc_inp->inp_in_hpts;
2630 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
2631 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
2632 		log.u_bbr.use_lt_bw = rack->r_ent_rec_ns;
2633 		log.u_bbr.use_lt_bw <<= 1;
2634 		log.u_bbr.use_lt_bw |= rack->r_might_revert;
2635 		log.u_bbr.pkts_out = rack->r_ctl.rc_out_at_rto;
2636 		log.u_bbr.delivered = rack->r_ctl.rc_snd_max_at_rto;
2637 		log.u_bbr.pacing_gain = rack->r_must_retran;
2638 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
2639 		    &rack->rc_inp->inp_socket->so_rcv,
2640 		    &rack->rc_inp->inp_socket->so_snd,
2641 		    BBR_LOG_DOSEG_DONE, 0,
2642 		    0, &log, false, &tv);
2643 	}
2644 }
2645 
2646 static void
2647 rack_log_type_pacing_sizes(struct tcpcb *tp, struct tcp_rack *rack, uint32_t arg1, uint32_t arg2, uint32_t arg3, uint8_t frm)
2648 {
2649 	if (tp->t_logstate != TCP_LOG_STATE_OFF) {
2650 		union tcp_log_stackspecific log;
2651 		struct timeval tv;
2652 		uint32_t cts;
2653 
2654 		memset(&log, 0, sizeof(log));
2655 		cts = tcp_get_usecs(&tv);
2656 		log.u_bbr.flex1 = rack->r_ctl.rc_pace_min_segs;
2657 		log.u_bbr.flex3 = rack->r_ctl.rc_pace_max_segs;
2658 		log.u_bbr.flex4 = arg1;
2659 		log.u_bbr.flex5 = arg2;
2660 		log.u_bbr.flex6 = arg3;
2661 		log.u_bbr.flex8 = frm;
2662 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
2663 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
2664 		log.u_bbr.pkts_out = rack->r_ctl.rc_out_at_rto;
2665 		log.u_bbr.applimited = rack->r_ctl.rc_sacked;
2666 		log.u_bbr.delivered = rack->r_ctl.rc_snd_max_at_rto;
2667 		log.u_bbr.pacing_gain = rack->r_must_retran;
2668 		TCP_LOG_EVENTP(tp, NULL,
2669 		    &tp->t_inpcb->inp_socket->so_rcv,
2670 		    &tp->t_inpcb->inp_socket->so_snd,
2671 		    TCP_HDWR_PACE_SIZE, 0,
2672 		    0, &log, false, &tv);
2673 	}
2674 }
2675 
2676 static void
2677 rack_log_type_just_return(struct tcp_rack *rack, uint32_t cts, uint32_t tlen, uint32_t slot,
2678 			  uint8_t hpts_calling, int reason, uint32_t cwnd_to_use)
2679 {
2680 	if (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
2681 		union tcp_log_stackspecific log;
2682 		struct timeval tv;
2683 
2684 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
2685 		log.u_bbr.inhpts = rack->rc_inp->inp_in_hpts;
2686 		log.u_bbr.ininput = rack->rc_inp->inp_in_input;
2687 		log.u_bbr.flex1 = slot;
2688 		log.u_bbr.flex2 = rack->r_ctl.rc_hpts_flags;
2689 		log.u_bbr.flex4 = reason;
2690 		if (rack->rack_no_prr)
2691 			log.u_bbr.flex5 = 0;
2692 		else
2693 			log.u_bbr.flex5 = rack->r_ctl.rc_prr_sndcnt;
2694 		log.u_bbr.flex7 = hpts_calling;
2695 		log.u_bbr.flex8 = rack->rc_in_persist;
2696 		log.u_bbr.lt_epoch = cwnd_to_use;
2697 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
2698 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
2699 		log.u_bbr.pkts_out = rack->r_ctl.rc_out_at_rto;
2700 		log.u_bbr.delivered = rack->r_ctl.rc_snd_max_at_rto;
2701 		log.u_bbr.pacing_gain = rack->r_must_retran;
2702 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
2703 		    &rack->rc_inp->inp_socket->so_rcv,
2704 		    &rack->rc_inp->inp_socket->so_snd,
2705 		    BBR_LOG_JUSTRET, 0,
2706 		    tlen, &log, false, &tv);
2707 	}
2708 }
2709 
2710 static void
2711 rack_log_to_cancel(struct tcp_rack *rack, int32_t hpts_removed, int line, uint32_t us_cts,
2712 		   struct timeval *tv, uint32_t flags_on_entry)
2713 {
2714 	if (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
2715 		union tcp_log_stackspecific log;
2716 
2717 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
2718 		log.u_bbr.inhpts = rack->rc_inp->inp_in_hpts;
2719 		log.u_bbr.ininput = rack->rc_inp->inp_in_input;
2720 		log.u_bbr.flex1 = line;
2721 		log.u_bbr.flex2 = rack->r_ctl.rc_last_output_to;
2722 		log.u_bbr.flex3 = flags_on_entry;
2723 		log.u_bbr.flex4 = us_cts;
2724 		if (rack->rack_no_prr)
2725 			log.u_bbr.flex5 = 0;
2726 		else
2727 			log.u_bbr.flex5 = rack->r_ctl.rc_prr_sndcnt;
2728 		log.u_bbr.flex6 = rack->rc_tp->t_rxtcur;
2729 		log.u_bbr.flex7 = hpts_removed;
2730 		log.u_bbr.flex8 = 1;
2731 		log.u_bbr.applimited = rack->r_ctl.rc_hpts_flags;
2732 		log.u_bbr.timeStamp = us_cts;
2733 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
2734 		log.u_bbr.pkts_out = rack->r_ctl.rc_out_at_rto;
2735 		log.u_bbr.delivered = rack->r_ctl.rc_snd_max_at_rto;
2736 		log.u_bbr.pacing_gain = rack->r_must_retran;
2737 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
2738 		    &rack->rc_inp->inp_socket->so_rcv,
2739 		    &rack->rc_inp->inp_socket->so_snd,
2740 		    BBR_LOG_TIMERCANC, 0,
2741 		    0, &log, false, tv);
2742 	}
2743 }
2744 
2745 static void
2746 rack_log_alt_to_to_cancel(struct tcp_rack *rack,
2747 			  uint32_t flex1, uint32_t flex2,
2748 			  uint32_t flex3, uint32_t flex4,
2749 			  uint32_t flex5, uint32_t flex6,
2750 			  uint16_t flex7, uint8_t mod)
2751 {
2752 	if (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
2753 		union tcp_log_stackspecific log;
2754 		struct timeval tv;
2755 
2756 		if (mod == 1) {
2757 			/* No you can't use 1, its for the real to cancel */
2758 			return;
2759 		}
2760 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
2761 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
2762 		log.u_bbr.flex1 = flex1;
2763 		log.u_bbr.flex2 = flex2;
2764 		log.u_bbr.flex3 = flex3;
2765 		log.u_bbr.flex4 = flex4;
2766 		log.u_bbr.flex5 = flex5;
2767 		log.u_bbr.flex6 = flex6;
2768 		log.u_bbr.flex7 = flex7;
2769 		log.u_bbr.flex8 = mod;
2770 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
2771 		    &rack->rc_inp->inp_socket->so_rcv,
2772 		    &rack->rc_inp->inp_socket->so_snd,
2773 		    BBR_LOG_TIMERCANC, 0,
2774 		    0, &log, false, &tv);
2775 	}
2776 }
2777 
2778 static void
2779 rack_log_to_processing(struct tcp_rack *rack, uint32_t cts, int32_t ret, int32_t timers)
2780 {
2781 	if (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
2782 		union tcp_log_stackspecific log;
2783 		struct timeval tv;
2784 
2785 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
2786 		log.u_bbr.flex1 = timers;
2787 		log.u_bbr.flex2 = ret;
2788 		log.u_bbr.flex3 = rack->r_ctl.rc_timer_exp;
2789 		log.u_bbr.flex4 = rack->r_ctl.rc_hpts_flags;
2790 		log.u_bbr.flex5 = cts;
2791 		if (rack->rack_no_prr)
2792 			log.u_bbr.flex6 = 0;
2793 		else
2794 			log.u_bbr.flex6 = rack->r_ctl.rc_prr_sndcnt;
2795 		log.u_bbr.pkts_out = rack->r_ctl.rc_out_at_rto;
2796 		log.u_bbr.delivered = rack->r_ctl.rc_snd_max_at_rto;
2797 		log.u_bbr.pacing_gain = rack->r_must_retran;
2798 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
2799 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
2800 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
2801 		    &rack->rc_inp->inp_socket->so_rcv,
2802 		    &rack->rc_inp->inp_socket->so_snd,
2803 		    BBR_LOG_TO_PROCESS, 0,
2804 		    0, &log, false, &tv);
2805 	}
2806 }
2807 
2808 static void
2809 rack_log_to_prr(struct tcp_rack *rack, int frm, int orig_cwnd)
2810 {
2811 	if (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
2812 		union tcp_log_stackspecific log;
2813 		struct timeval tv;
2814 
2815 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
2816 		log.u_bbr.flex1 = rack->r_ctl.rc_prr_out;
2817 		log.u_bbr.flex2 = rack->r_ctl.rc_prr_recovery_fs;
2818 		if (rack->rack_no_prr)
2819 			log.u_bbr.flex3 = 0;
2820 		else
2821 			log.u_bbr.flex3 = rack->r_ctl.rc_prr_sndcnt;
2822 		log.u_bbr.flex4 = rack->r_ctl.rc_prr_delivered;
2823 		log.u_bbr.flex5 = rack->r_ctl.rc_sacked;
2824 		log.u_bbr.flex6 = rack->r_ctl.rc_holes_rxt;
2825 		log.u_bbr.flex8 = frm;
2826 		log.u_bbr.pkts_out = orig_cwnd;
2827 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
2828 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
2829 		log.u_bbr.use_lt_bw = rack->r_ent_rec_ns;
2830 		log.u_bbr.use_lt_bw <<= 1;
2831 		log.u_bbr.use_lt_bw |= rack->r_might_revert;
2832 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
2833 		    &rack->rc_inp->inp_socket->so_rcv,
2834 		    &rack->rc_inp->inp_socket->so_snd,
2835 		    BBR_LOG_BBRUPD, 0,
2836 		    0, &log, false, &tv);
2837 	}
2838 }
2839 
2840 #ifdef NETFLIX_EXP_DETECTION
2841 static void
2842 rack_log_sad(struct tcp_rack *rack, int event)
2843 {
2844 	if (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
2845 		union tcp_log_stackspecific log;
2846 		struct timeval tv;
2847 
2848 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
2849 		log.u_bbr.flex1 = rack->r_ctl.sack_count;
2850 		log.u_bbr.flex2 = rack->r_ctl.ack_count;
2851 		log.u_bbr.flex3 = rack->r_ctl.sack_moved_extra;
2852 		log.u_bbr.flex4 = rack->r_ctl.sack_noextra_move;
2853 		log.u_bbr.flex5 = rack->r_ctl.rc_num_maps_alloced;
2854 		log.u_bbr.flex6 = tcp_sack_to_ack_thresh;
2855 		log.u_bbr.pkts_out = tcp_sack_to_move_thresh;
2856 		log.u_bbr.lt_epoch = (tcp_force_detection << 8);
2857 		log.u_bbr.lt_epoch |= rack->do_detection;
2858 		log.u_bbr.applimited = tcp_map_minimum;
2859 		log.u_bbr.flex7 = rack->sack_attack_disable;
2860 		log.u_bbr.flex8 = event;
2861 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
2862 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
2863 		log.u_bbr.delivered = tcp_sad_decay_val;
2864 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
2865 		    &rack->rc_inp->inp_socket->so_rcv,
2866 		    &rack->rc_inp->inp_socket->so_snd,
2867 		    TCP_SAD_DETECTION, 0,
2868 		    0, &log, false, &tv);
2869 	}
2870 }
2871 #endif
2872 
2873 static void
2874 rack_counter_destroy(void)
2875 {
2876 	int i;
2877 
2878 	counter_u64_free(rack_fto_send);
2879 	counter_u64_free(rack_fto_rsm_send);
2880 	counter_u64_free(rack_nfto_resend);
2881 	counter_u64_free(rack_hw_pace_init_fail);
2882 	counter_u64_free(rack_hw_pace_lost);
2883 	counter_u64_free(rack_non_fto_send);
2884 	counter_u64_free(rack_extended_rfo);
2885 	counter_u64_free(rack_ack_total);
2886 	counter_u64_free(rack_express_sack);
2887 	counter_u64_free(rack_sack_total);
2888 	counter_u64_free(rack_move_none);
2889 	counter_u64_free(rack_move_some);
2890 	counter_u64_free(rack_sack_attacks_detected);
2891 	counter_u64_free(rack_sack_attacks_reversed);
2892 	counter_u64_free(rack_sack_used_next_merge);
2893 	counter_u64_free(rack_sack_used_prev_merge);
2894 	counter_u64_free(rack_badfr);
2895 	counter_u64_free(rack_badfr_bytes);
2896 	counter_u64_free(rack_rtm_prr_retran);
2897 	counter_u64_free(rack_rtm_prr_newdata);
2898 	counter_u64_free(rack_timestamp_mismatch);
2899 	counter_u64_free(rack_find_high);
2900 	counter_u64_free(rack_reorder_seen);
2901 	counter_u64_free(rack_tlp_tot);
2902 	counter_u64_free(rack_tlp_newdata);
2903 	counter_u64_free(rack_tlp_retran);
2904 	counter_u64_free(rack_tlp_retran_bytes);
2905 	counter_u64_free(rack_tlp_retran_fail);
2906 	counter_u64_free(rack_to_tot);
2907 	counter_u64_free(rack_to_arm_rack);
2908 	counter_u64_free(rack_to_arm_tlp);
2909 	counter_u64_free(rack_calc_zero);
2910 	counter_u64_free(rack_calc_nonzero);
2911 	counter_u64_free(rack_paced_segments);
2912 	counter_u64_free(rack_unpaced_segments);
2913 	counter_u64_free(rack_saw_enobuf);
2914 	counter_u64_free(rack_saw_enobuf_hw);
2915 	counter_u64_free(rack_saw_enetunreach);
2916 	counter_u64_free(rack_hot_alloc);
2917 	counter_u64_free(rack_to_alloc);
2918 	counter_u64_free(rack_to_alloc_hard);
2919 	counter_u64_free(rack_to_alloc_emerg);
2920 	counter_u64_free(rack_to_alloc_limited);
2921 	counter_u64_free(rack_alloc_limited_conns);
2922 	counter_u64_free(rack_split_limited);
2923 	for (i = 0; i < MAX_NUM_OF_CNTS; i++) {
2924 		counter_u64_free(rack_proc_comp_ack[i]);
2925 	}
2926 	counter_u64_free(rack_multi_single_eq);
2927 	counter_u64_free(rack_proc_non_comp_ack);
2928 	counter_u64_free(rack_sack_proc_all);
2929 	counter_u64_free(rack_sack_proc_restart);
2930 	counter_u64_free(rack_sack_proc_short);
2931 	counter_u64_free(rack_enter_tlp_calc);
2932 	counter_u64_free(rack_used_tlpmethod);
2933 	counter_u64_free(rack_used_tlpmethod2);
2934 	counter_u64_free(rack_sack_skipped_acked);
2935 	counter_u64_free(rack_sack_splits);
2936 	counter_u64_free(rack_progress_drops);
2937 	counter_u64_free(rack_input_idle_reduces);
2938 	counter_u64_free(rack_collapsed_win);
2939 	counter_u64_free(rack_tlp_does_nada);
2940 	counter_u64_free(rack_try_scwnd);
2941 	counter_u64_free(rack_per_timer_hole);
2942 	counter_u64_free(rack_large_ackcmp);
2943 	counter_u64_free(rack_small_ackcmp);
2944 #ifdef INVARIANTS
2945 	counter_u64_free(rack_adjust_map_bw);
2946 #endif
2947 	COUNTER_ARRAY_FREE(rack_out_size, TCP_MSS_ACCT_SIZE);
2948 	COUNTER_ARRAY_FREE(rack_opts_arry, RACK_OPTS_SIZE);
2949 }
2950 
2951 static struct rack_sendmap *
2952 rack_alloc(struct tcp_rack *rack)
2953 {
2954 	struct rack_sendmap *rsm;
2955 
2956 	/*
2957 	 * First get the top of the list it in
2958 	 * theory is the "hottest" rsm we have,
2959 	 * possibly just freed by ack processing.
2960 	 */
2961 	if (rack->rc_free_cnt > rack_free_cache) {
2962 		rsm = TAILQ_FIRST(&rack->r_ctl.rc_free);
2963 		TAILQ_REMOVE(&rack->r_ctl.rc_free, rsm, r_tnext);
2964 		counter_u64_add(rack_hot_alloc, 1);
2965 		rack->rc_free_cnt--;
2966 		return (rsm);
2967 	}
2968 	/*
2969 	 * Once we get under our free cache we probably
2970 	 * no longer have a "hot" one available. Lets
2971 	 * get one from UMA.
2972 	 */
2973 	rsm = uma_zalloc(rack_zone, M_NOWAIT);
2974 	if (rsm) {
2975 		rack->r_ctl.rc_num_maps_alloced++;
2976 		counter_u64_add(rack_to_alloc, 1);
2977 		return (rsm);
2978 	}
2979 	/*
2980 	 * Dig in to our aux rsm's (the last two) since
2981 	 * UMA failed to get us one.
2982 	 */
2983 	if (rack->rc_free_cnt) {
2984 		counter_u64_add(rack_to_alloc_emerg, 1);
2985 		rsm = TAILQ_FIRST(&rack->r_ctl.rc_free);
2986 		TAILQ_REMOVE(&rack->r_ctl.rc_free, rsm, r_tnext);
2987 		rack->rc_free_cnt--;
2988 		return (rsm);
2989 	}
2990 	return (NULL);
2991 }
2992 
2993 static struct rack_sendmap *
2994 rack_alloc_full_limit(struct tcp_rack *rack)
2995 {
2996 	if ((V_tcp_map_entries_limit > 0) &&
2997 	    (rack->do_detection == 0) &&
2998 	    (rack->r_ctl.rc_num_maps_alloced >= V_tcp_map_entries_limit)) {
2999 		counter_u64_add(rack_to_alloc_limited, 1);
3000 		if (!rack->alloc_limit_reported) {
3001 			rack->alloc_limit_reported = 1;
3002 			counter_u64_add(rack_alloc_limited_conns, 1);
3003 		}
3004 		return (NULL);
3005 	}
3006 	return (rack_alloc(rack));
3007 }
3008 
3009 /* wrapper to allocate a sendmap entry, subject to a specific limit */
3010 static struct rack_sendmap *
3011 rack_alloc_limit(struct tcp_rack *rack, uint8_t limit_type)
3012 {
3013 	struct rack_sendmap *rsm;
3014 
3015 	if (limit_type) {
3016 		/* currently there is only one limit type */
3017 		if (V_tcp_map_split_limit > 0 &&
3018 		    (rack->do_detection == 0) &&
3019 		    rack->r_ctl.rc_num_split_allocs >= V_tcp_map_split_limit) {
3020 			counter_u64_add(rack_split_limited, 1);
3021 			if (!rack->alloc_limit_reported) {
3022 				rack->alloc_limit_reported = 1;
3023 				counter_u64_add(rack_alloc_limited_conns, 1);
3024 			}
3025 			return (NULL);
3026 		}
3027 	}
3028 
3029 	/* allocate and mark in the limit type, if set */
3030 	rsm = rack_alloc(rack);
3031 	if (rsm != NULL && limit_type) {
3032 		rsm->r_limit_type = limit_type;
3033 		rack->r_ctl.rc_num_split_allocs++;
3034 	}
3035 	return (rsm);
3036 }
3037 
3038 static void
3039 rack_free(struct tcp_rack *rack, struct rack_sendmap *rsm)
3040 {
3041 	if (rsm->r_flags & RACK_APP_LIMITED) {
3042 		if (rack->r_ctl.rc_app_limited_cnt > 0) {
3043 			rack->r_ctl.rc_app_limited_cnt--;
3044 		}
3045 	}
3046 	if (rsm->r_limit_type) {
3047 		/* currently there is only one limit type */
3048 		rack->r_ctl.rc_num_split_allocs--;
3049 	}
3050 	if (rsm == rack->r_ctl.rc_first_appl) {
3051 		if (rack->r_ctl.rc_app_limited_cnt == 0)
3052 			rack->r_ctl.rc_first_appl = NULL;
3053 		else {
3054 			/* Follow the next one out */
3055 			struct rack_sendmap fe;
3056 
3057 			fe.r_start = rsm->r_nseq_appl;
3058 			rack->r_ctl.rc_first_appl = RB_FIND(rack_rb_tree_head, &rack->r_ctl.rc_mtree, &fe);
3059 		}
3060 	}
3061 	if (rsm == rack->r_ctl.rc_resend)
3062 		rack->r_ctl.rc_resend = NULL;
3063 	if (rsm == rack->r_ctl.rc_rsm_at_retran)
3064 		rack->r_ctl.rc_rsm_at_retran = NULL;
3065 	if (rsm == rack->r_ctl.rc_end_appl)
3066 		rack->r_ctl.rc_end_appl = NULL;
3067 	if (rack->r_ctl.rc_tlpsend == rsm)
3068 		rack->r_ctl.rc_tlpsend = NULL;
3069 	if (rack->r_ctl.rc_sacklast == rsm)
3070 		rack->r_ctl.rc_sacklast = NULL;
3071 	memset(rsm, 0, sizeof(struct rack_sendmap));
3072 	TAILQ_INSERT_HEAD(&rack->r_ctl.rc_free, rsm, r_tnext);
3073 	rack->rc_free_cnt++;
3074 }
3075 
3076 static void
3077 rack_free_trim(struct tcp_rack *rack)
3078 {
3079 	struct rack_sendmap *rsm;
3080 
3081 	/*
3082 	 * Free up all the tail entries until
3083 	 * we get our list down to the limit.
3084 	 */
3085 	while (rack->rc_free_cnt > rack_free_cache) {
3086 		rsm = TAILQ_LAST(&rack->r_ctl.rc_free, rack_head);
3087 		TAILQ_REMOVE(&rack->r_ctl.rc_free, rsm, r_tnext);
3088 		rack->rc_free_cnt--;
3089 		uma_zfree(rack_zone, rsm);
3090 	}
3091 }
3092 
3093 
3094 static uint32_t
3095 rack_get_measure_window(struct tcpcb *tp, struct tcp_rack *rack)
3096 {
3097 	uint64_t srtt, bw, len, tim;
3098 	uint32_t segsiz, def_len, minl;
3099 
3100 	segsiz = min(ctf_fixed_maxseg(tp), rack->r_ctl.rc_pace_min_segs);
3101 	def_len = rack_def_data_window * segsiz;
3102 	if (rack->rc_gp_filled == 0) {
3103 		/*
3104 		 * We have no measurement (IW is in flight?) so
3105 		 * we can only guess using our data_window sysctl
3106 		 * value (usually 20MSS).
3107 		 */
3108 		return (def_len);
3109 	}
3110 	/*
3111 	 * Now we have a number of factors to consider.
3112 	 *
3113 	 * 1) We have a desired BDP which is usually
3114 	 *    at least 2.
3115 	 * 2) We have a minimum number of rtt's usually 1 SRTT
3116 	 *    but we allow it too to be more.
3117 	 * 3) We want to make sure a measurement last N useconds (if
3118 	 *    we have set rack_min_measure_usec.
3119 	 *
3120 	 * We handle the first concern here by trying to create a data
3121 	 * window of max(rack_def_data_window, DesiredBDP). The
3122 	 * second concern we handle in not letting the measurement
3123 	 * window end normally until at least the required SRTT's
3124 	 * have gone by which is done further below in
3125 	 * rack_enough_for_measurement(). Finally the third concern
3126 	 * we also handle here by calculating how long that time
3127 	 * would take at the current BW and then return the
3128 	 * max of our first calculation and that length. Note
3129 	 * that if rack_min_measure_usec is 0, we don't deal
3130 	 * with concern 3. Also for both Concern 1 and 3 an
3131 	 * application limited period could end the measurement
3132 	 * earlier.
3133 	 *
3134 	 * So lets calculate the BDP with the "known" b/w using
3135 	 * the SRTT has our rtt and then multiply it by the
3136 	 * goal.
3137 	 */
3138 	bw = rack_get_bw(rack);
3139 	srtt = (uint64_t)tp->t_srtt;
3140 	len = bw * srtt;
3141 	len /= (uint64_t)HPTS_USEC_IN_SEC;
3142 	len *= max(1, rack_goal_bdp);
3143 	/* Now we need to round up to the nearest MSS */
3144 	len = roundup(len, segsiz);
3145 	if (rack_min_measure_usec) {
3146 		/* Now calculate our min length for this b/w */
3147 		tim = rack_min_measure_usec;
3148 		minl = (tim * bw) / (uint64_t)HPTS_USEC_IN_SEC;
3149 		if (minl == 0)
3150 			minl = 1;
3151 		minl = roundup(minl, segsiz);
3152 		if (len < minl)
3153 			len = minl;
3154 	}
3155 	/*
3156 	 * Now if we have a very small window we want
3157 	 * to attempt to get the window that is
3158 	 * as small as possible. This happens on
3159 	 * low b/w connections and we don't want to
3160 	 * span huge numbers of rtt's between measurements.
3161 	 *
3162 	 * We basically include 2 over our "MIN window" so
3163 	 * that the measurement can be shortened (possibly) by
3164 	 * an ack'ed packet.
3165 	 */
3166 	if (len < def_len)
3167 		return (max((uint32_t)len, ((MIN_GP_WIN+2) * segsiz)));
3168 	else
3169 		return (max((uint32_t)len, def_len));
3170 
3171 }
3172 
3173 static int
3174 rack_enough_for_measurement(struct tcpcb *tp, struct tcp_rack *rack, tcp_seq th_ack, uint8_t *quality)
3175 {
3176 	uint32_t tim, srtts, segsiz;
3177 
3178 	/*
3179 	 * Has enough time passed for the GP measurement to be valid?
3180 	 */
3181 	if ((tp->snd_max == tp->snd_una) ||
3182 	    (th_ack == tp->snd_max)){
3183 		/* All is acked */
3184 		*quality = RACK_QUALITY_ALLACKED;
3185 		return (1);
3186 	}
3187 	if (SEQ_LT(th_ack, tp->gput_seq)) {
3188 		/* Not enough bytes yet */
3189 		return (0);
3190 	}
3191 	segsiz = min(ctf_fixed_maxseg(tp), rack->r_ctl.rc_pace_min_segs);
3192 	if (SEQ_LT(th_ack, tp->gput_ack) &&
3193 	    ((th_ack - tp->gput_seq) < max(rc_init_window(rack), (MIN_GP_WIN * segsiz)))) {
3194 		/* Not enough bytes yet */
3195 		return (0);
3196 	}
3197 	if (rack->r_ctl.rc_first_appl &&
3198 	    (SEQ_GEQ(th_ack, rack->r_ctl.rc_first_appl->r_end))) {
3199 		/*
3200 		 * We are up to the app limited send point
3201 		 * we have to measure irrespective of the time..
3202 		 */
3203 		*quality = RACK_QUALITY_APPLIMITED;
3204 		return (1);
3205 	}
3206 	/* Now what about time? */
3207 	srtts = (rack->r_ctl.rc_gp_srtt * rack_min_srtts);
3208 	tim = tcp_tv_to_usectick(&rack->r_ctl.act_rcv_time) - tp->gput_ts;
3209 	if (tim >= srtts) {
3210 		*quality = RACK_QUALITY_HIGH;
3211 		return (1);
3212 	}
3213 	/* Nope not even a full SRTT has passed */
3214 	return (0);
3215 }
3216 
3217 static void
3218 rack_log_timely(struct tcp_rack *rack,
3219 		uint32_t logged, uint64_t cur_bw, uint64_t low_bnd,
3220 		uint64_t up_bnd, int line, uint8_t method)
3221 {
3222 	if (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
3223 		union tcp_log_stackspecific log;
3224 		struct timeval tv;
3225 
3226 		memset(&log, 0, sizeof(log));
3227 		log.u_bbr.flex1 = logged;
3228 		log.u_bbr.flex2 = rack->rc_gp_timely_inc_cnt;
3229 		log.u_bbr.flex2 <<= 4;
3230 		log.u_bbr.flex2 |= rack->rc_gp_timely_dec_cnt;
3231 		log.u_bbr.flex2 <<= 4;
3232 		log.u_bbr.flex2 |= rack->rc_gp_incr;
3233 		log.u_bbr.flex2 <<= 4;
3234 		log.u_bbr.flex2 |= rack->rc_gp_bwred;
3235 		log.u_bbr.flex3 = rack->rc_gp_incr;
3236 		log.u_bbr.flex4 = rack->r_ctl.rack_per_of_gp_ss;
3237 		log.u_bbr.flex5 = rack->r_ctl.rack_per_of_gp_ca;
3238 		log.u_bbr.flex6 = rack->r_ctl.rack_per_of_gp_rec;
3239 		log.u_bbr.flex7 = rack->rc_gp_bwred;
3240 		log.u_bbr.flex8 = method;
3241 		log.u_bbr.cur_del_rate = cur_bw;
3242 		log.u_bbr.delRate = low_bnd;
3243 		log.u_bbr.bw_inuse = up_bnd;
3244 		log.u_bbr.rttProp = rack_get_bw(rack);
3245 		log.u_bbr.pkt_epoch = line;
3246 		log.u_bbr.pkts_out = rack->r_ctl.rc_rtt_diff;
3247 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
3248 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
3249 		log.u_bbr.epoch = rack->r_ctl.rc_gp_srtt;
3250 		log.u_bbr.lt_epoch = rack->r_ctl.rc_prev_gp_srtt;
3251 		log.u_bbr.cwnd_gain = rack->rc_dragged_bottom;
3252 		log.u_bbr.cwnd_gain <<= 1;
3253 		log.u_bbr.cwnd_gain |= rack->rc_gp_saw_rec;
3254 		log.u_bbr.cwnd_gain <<= 1;
3255 		log.u_bbr.cwnd_gain |= rack->rc_gp_saw_ss;
3256 		log.u_bbr.cwnd_gain <<= 1;
3257 		log.u_bbr.cwnd_gain |= rack->rc_gp_saw_ca;
3258 		log.u_bbr.lost = rack->r_ctl.rc_loss_count;
3259 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
3260 		    &rack->rc_inp->inp_socket->so_rcv,
3261 		    &rack->rc_inp->inp_socket->so_snd,
3262 		    TCP_TIMELY_WORK, 0,
3263 		    0, &log, false, &tv);
3264 	}
3265 }
3266 
3267 static int
3268 rack_bw_can_be_raised(struct tcp_rack *rack, uint64_t cur_bw, uint64_t last_bw_est, uint16_t mult)
3269 {
3270 	/*
3271 	 * Before we increase we need to know if
3272 	 * the estimate just made was less than
3273 	 * our pacing goal (i.e. (cur_bw * mult) > last_bw_est)
3274 	 *
3275 	 * If we already are pacing at a fast enough
3276 	 * rate to push us faster there is no sense of
3277 	 * increasing.
3278 	 *
3279 	 * We first caculate our actual pacing rate (ss or ca multipler
3280 	 * times our cur_bw).
3281 	 *
3282 	 * Then we take the last measured rate and multipy by our
3283 	 * maximum pacing overage to give us a max allowable rate.
3284 	 *
3285 	 * If our act_rate is smaller than our max_allowable rate
3286 	 * then we should increase. Else we should hold steady.
3287 	 *
3288 	 */
3289 	uint64_t act_rate, max_allow_rate;
3290 
3291 	if (rack_timely_no_stopping)
3292 		return (1);
3293 
3294 	if ((cur_bw == 0) || (last_bw_est == 0)) {
3295 		/*
3296 		 * Initial startup case or
3297 		 * everything is acked case.
3298 		 */
3299 		rack_log_timely(rack,  mult, cur_bw, 0, 0,
3300 				__LINE__, 9);
3301 		return (1);
3302 	}
3303 	if (mult <= 100) {
3304 		/*
3305 		 * We can always pace at or slightly above our rate.
3306 		 */
3307 		rack_log_timely(rack,  mult, cur_bw, 0, 0,
3308 				__LINE__, 9);
3309 		return (1);
3310 	}
3311 	act_rate = cur_bw * (uint64_t)mult;
3312 	act_rate /= 100;
3313 	max_allow_rate = last_bw_est * ((uint64_t)rack_max_per_above + (uint64_t)100);
3314 	max_allow_rate /= 100;
3315 	if (act_rate < max_allow_rate) {
3316 		/*
3317 		 * Here the rate we are actually pacing at
3318 		 * is smaller than 10% above our last measurement.
3319 		 * This means we are pacing below what we would
3320 		 * like to try to achieve (plus some wiggle room).
3321 		 */
3322 		rack_log_timely(rack,  mult, cur_bw, act_rate, max_allow_rate,
3323 				__LINE__, 9);
3324 		return (1);
3325 	} else {
3326 		/*
3327 		 * Here we are already pacing at least rack_max_per_above(10%)
3328 		 * what we are getting back. This indicates most likely
3329 		 * that we are being limited (cwnd/rwnd/app) and can't
3330 		 * get any more b/w. There is no sense of trying to
3331 		 * raise up the pacing rate its not speeding us up
3332 		 * and we already are pacing faster than we are getting.
3333 		 */
3334 		rack_log_timely(rack,  mult, cur_bw, act_rate, max_allow_rate,
3335 				__LINE__, 8);
3336 		return (0);
3337 	}
3338 }
3339 
3340 static void
3341 rack_validate_multipliers_at_or_above100(struct tcp_rack *rack)
3342 {
3343 	/*
3344 	 * When we drag bottom, we want to assure
3345 	 * that no multiplier is below 1.0, if so
3346 	 * we want to restore it to at least that.
3347 	 */
3348 	if (rack->r_ctl.rack_per_of_gp_rec  < 100) {
3349 		/* This is unlikely we usually do not touch recovery */
3350 		rack->r_ctl.rack_per_of_gp_rec = 100;
3351 	}
3352 	if (rack->r_ctl.rack_per_of_gp_ca < 100) {
3353 		rack->r_ctl.rack_per_of_gp_ca = 100;
3354 	}
3355 	if (rack->r_ctl.rack_per_of_gp_ss < 100) {
3356 		rack->r_ctl.rack_per_of_gp_ss = 100;
3357 	}
3358 }
3359 
3360 static void
3361 rack_validate_multipliers_at_or_below_100(struct tcp_rack *rack)
3362 {
3363 	if (rack->r_ctl.rack_per_of_gp_ca > 100) {
3364 		rack->r_ctl.rack_per_of_gp_ca = 100;
3365 	}
3366 	if (rack->r_ctl.rack_per_of_gp_ss > 100) {
3367 		rack->r_ctl.rack_per_of_gp_ss = 100;
3368 	}
3369 }
3370 
3371 static void
3372 rack_increase_bw_mul(struct tcp_rack *rack, int timely_says, uint64_t cur_bw, uint64_t last_bw_est, int override)
3373 {
3374 	int32_t  calc, logged, plus;
3375 
3376 	logged = 0;
3377 
3378 	if (override) {
3379 		/*
3380 		 * override is passed when we are
3381 		 * loosing b/w and making one last
3382 		 * gasp at trying to not loose out
3383 		 * to a new-reno flow.
3384 		 */
3385 		goto extra_boost;
3386 	}
3387 	/* In classic timely we boost by 5x if we have 5 increases in a row, lets not */
3388 	if (rack->rc_gp_incr &&
3389 	    ((rack->rc_gp_timely_inc_cnt + 1) >= RACK_TIMELY_CNT_BOOST)) {
3390 		/*
3391 		 * Reset and get 5 strokes more before the boost. Note
3392 		 * that the count is 0 based so we have to add one.
3393 		 */
3394 extra_boost:
3395 		plus = (uint32_t)rack_gp_increase_per * RACK_TIMELY_CNT_BOOST;
3396 		rack->rc_gp_timely_inc_cnt = 0;
3397 	} else
3398 		plus = (uint32_t)rack_gp_increase_per;
3399 	/* Must be at least 1% increase for true timely increases */
3400 	if ((plus < 1) &&
3401 	    ((rack->r_ctl.rc_rtt_diff <= 0) || (timely_says <= 0)))
3402 		plus = 1;
3403 	if (rack->rc_gp_saw_rec &&
3404 	    (rack->rc_gp_no_rec_chg == 0) &&
3405 	    rack_bw_can_be_raised(rack, cur_bw, last_bw_est,
3406 				  rack->r_ctl.rack_per_of_gp_rec)) {
3407 		/* We have been in recovery ding it too */
3408 		calc = rack->r_ctl.rack_per_of_gp_rec + plus;
3409 		if (calc > 0xffff)
3410 			calc = 0xffff;
3411 		logged |= 1;
3412 		rack->r_ctl.rack_per_of_gp_rec = (uint16_t)calc;
3413 		if (rack_per_upper_bound_ss &&
3414 		    (rack->rc_dragged_bottom == 0) &&
3415 		    (rack->r_ctl.rack_per_of_gp_rec > rack_per_upper_bound_ss))
3416 			rack->r_ctl.rack_per_of_gp_rec = rack_per_upper_bound_ss;
3417 	}
3418 	if (rack->rc_gp_saw_ca &&
3419 	    (rack->rc_gp_saw_ss == 0) &&
3420 	    rack_bw_can_be_raised(rack, cur_bw, last_bw_est,
3421 				  rack->r_ctl.rack_per_of_gp_ca)) {
3422 		/* In CA */
3423 		calc = rack->r_ctl.rack_per_of_gp_ca + plus;
3424 		if (calc > 0xffff)
3425 			calc = 0xffff;
3426 		logged |= 2;
3427 		rack->r_ctl.rack_per_of_gp_ca = (uint16_t)calc;
3428 		if (rack_per_upper_bound_ca &&
3429 		    (rack->rc_dragged_bottom == 0) &&
3430 		    (rack->r_ctl.rack_per_of_gp_ca > rack_per_upper_bound_ca))
3431 			rack->r_ctl.rack_per_of_gp_ca = rack_per_upper_bound_ca;
3432 	}
3433 	if (rack->rc_gp_saw_ss &&
3434 	    rack_bw_can_be_raised(rack, cur_bw, last_bw_est,
3435 				  rack->r_ctl.rack_per_of_gp_ss)) {
3436 		/* In SS */
3437 		calc = rack->r_ctl.rack_per_of_gp_ss + plus;
3438 		if (calc > 0xffff)
3439 			calc = 0xffff;
3440 		rack->r_ctl.rack_per_of_gp_ss = (uint16_t)calc;
3441 		if (rack_per_upper_bound_ss &&
3442 		    (rack->rc_dragged_bottom == 0) &&
3443 		    (rack->r_ctl.rack_per_of_gp_ss > rack_per_upper_bound_ss))
3444 			rack->r_ctl.rack_per_of_gp_ss = rack_per_upper_bound_ss;
3445 		logged |= 4;
3446 	}
3447 	if (logged &&
3448 	    (rack->rc_gp_incr == 0)){
3449 		/* Go into increment mode */
3450 		rack->rc_gp_incr = 1;
3451 		rack->rc_gp_timely_inc_cnt = 0;
3452 	}
3453 	if (rack->rc_gp_incr &&
3454 	    logged &&
3455 	    (rack->rc_gp_timely_inc_cnt < RACK_TIMELY_CNT_BOOST)) {
3456 		rack->rc_gp_timely_inc_cnt++;
3457 	}
3458 	rack_log_timely(rack,  logged, plus, 0, 0,
3459 			__LINE__, 1);
3460 }
3461 
3462 static uint32_t
3463 rack_get_decrease(struct tcp_rack *rack, uint32_t curper, int32_t rtt_diff)
3464 {
3465 	/*
3466 	 * norm_grad = rtt_diff / minrtt;
3467 	 * new_per = curper * (1 - B * norm_grad)
3468 	 *
3469 	 * B = rack_gp_decrease_per (default 10%)
3470 	 * rtt_dif = input var current rtt-diff
3471 	 * curper = input var current percentage
3472 	 * minrtt = from rack filter
3473 	 *
3474 	 */
3475 	uint64_t perf;
3476 
3477 	perf = (((uint64_t)curper * ((uint64_t)1000000 -
3478 		    ((uint64_t)rack_gp_decrease_per * (uint64_t)10000 *
3479 		     (((uint64_t)rtt_diff * (uint64_t)1000000)/
3480 		      (uint64_t)get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt)))/
3481 		     (uint64_t)1000000)) /
3482 		(uint64_t)1000000);
3483 	if (perf > curper) {
3484 		/* TSNH */
3485 		perf = curper - 1;
3486 	}
3487 	return ((uint32_t)perf);
3488 }
3489 
3490 static uint32_t
3491 rack_decrease_highrtt(struct tcp_rack *rack, uint32_t curper, uint32_t rtt)
3492 {
3493 	/*
3494 	 *                                   highrttthresh
3495 	 * result = curper * (1 - (B * ( 1 -  ------          ))
3496 	 *                                     gp_srtt
3497 	 *
3498 	 * B = rack_gp_decrease_per (default 10%)
3499 	 * highrttthresh = filter_min * rack_gp_rtt_maxmul
3500 	 */
3501 	uint64_t perf;
3502 	uint32_t highrttthresh;
3503 
3504 	highrttthresh = get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt) * rack_gp_rtt_maxmul;
3505 
3506 	perf = (((uint64_t)curper * ((uint64_t)1000000 -
3507 				     ((uint64_t)rack_gp_decrease_per * ((uint64_t)1000000 -
3508 					((uint64_t)highrttthresh * (uint64_t)1000000) /
3509 						    (uint64_t)rtt)) / 100)) /(uint64_t)1000000);
3510 	return (perf);
3511 }
3512 
3513 static void
3514 rack_decrease_bw_mul(struct tcp_rack *rack, int timely_says, uint32_t rtt, int32_t rtt_diff)
3515 {
3516 	uint64_t logvar, logvar2, logvar3;
3517 	uint32_t logged, new_per, ss_red, ca_red, rec_red, alt, val;
3518 
3519 	if (rack->rc_gp_incr) {
3520 		/* Turn off increment counting */
3521 		rack->rc_gp_incr = 0;
3522 		rack->rc_gp_timely_inc_cnt = 0;
3523 	}
3524 	ss_red = ca_red = rec_red = 0;
3525 	logged = 0;
3526 	/* Calculate the reduction value */
3527 	if (rtt_diff < 0) {
3528 		rtt_diff *= -1;
3529 	}
3530 	/* Must be at least 1% reduction */
3531 	if (rack->rc_gp_saw_rec && (rack->rc_gp_no_rec_chg == 0)) {
3532 		/* We have been in recovery ding it too */
3533 		if (timely_says == 2) {
3534 			new_per = rack_decrease_highrtt(rack, rack->r_ctl.rack_per_of_gp_rec, rtt);
3535 			alt = rack_get_decrease(rack, rack->r_ctl.rack_per_of_gp_rec, rtt_diff);
3536 			if (alt < new_per)
3537 				val = alt;
3538 			else
3539 				val = new_per;
3540 		} else
3541 			 val = new_per = alt = rack_get_decrease(rack, rack->r_ctl.rack_per_of_gp_rec, rtt_diff);
3542 		if (rack->r_ctl.rack_per_of_gp_rec > val) {
3543 			rec_red = (rack->r_ctl.rack_per_of_gp_rec - val);
3544 			rack->r_ctl.rack_per_of_gp_rec = (uint16_t)val;
3545 		} else {
3546 			rack->r_ctl.rack_per_of_gp_rec = rack_per_lower_bound;
3547 			rec_red = 0;
3548 		}
3549 		if (rack_per_lower_bound > rack->r_ctl.rack_per_of_gp_rec)
3550 			rack->r_ctl.rack_per_of_gp_rec = rack_per_lower_bound;
3551 		logged |= 1;
3552 	}
3553 	if (rack->rc_gp_saw_ss) {
3554 		/* Sent in SS */
3555 		if (timely_says == 2) {
3556 			new_per = rack_decrease_highrtt(rack, rack->r_ctl.rack_per_of_gp_ss, rtt);
3557 			alt = rack_get_decrease(rack, rack->r_ctl.rack_per_of_gp_rec, rtt_diff);
3558 			if (alt < new_per)
3559 				val = alt;
3560 			else
3561 				val = new_per;
3562 		} else
3563 			val = new_per = alt = rack_get_decrease(rack, rack->r_ctl.rack_per_of_gp_ss, rtt_diff);
3564 		if (rack->r_ctl.rack_per_of_gp_ss > new_per) {
3565 			ss_red = rack->r_ctl.rack_per_of_gp_ss - val;
3566 			rack->r_ctl.rack_per_of_gp_ss = (uint16_t)val;
3567 		} else {
3568 			ss_red = new_per;
3569 			rack->r_ctl.rack_per_of_gp_ss = rack_per_lower_bound;
3570 			logvar = new_per;
3571 			logvar <<= 32;
3572 			logvar |= alt;
3573 			logvar2 = (uint32_t)rtt;
3574 			logvar2 <<= 32;
3575 			logvar2 |= (uint32_t)rtt_diff;
3576 			logvar3 = rack_gp_rtt_maxmul;
3577 			logvar3 <<= 32;
3578 			logvar3 |= get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt);
3579 			rack_log_timely(rack, timely_says,
3580 					logvar2, logvar3,
3581 					logvar, __LINE__, 10);
3582 		}
3583 		if (rack_per_lower_bound > rack->r_ctl.rack_per_of_gp_ss)
3584 			rack->r_ctl.rack_per_of_gp_ss = rack_per_lower_bound;
3585 		logged |= 4;
3586 	} else if (rack->rc_gp_saw_ca) {
3587 		/* Sent in CA */
3588 		if (timely_says == 2) {
3589 			new_per = rack_decrease_highrtt(rack, rack->r_ctl.rack_per_of_gp_ca, rtt);
3590 			alt = rack_get_decrease(rack, rack->r_ctl.rack_per_of_gp_rec, rtt_diff);
3591 			if (alt < new_per)
3592 				val = alt;
3593 			else
3594 				val = new_per;
3595 		} else
3596 			val = new_per = alt = rack_get_decrease(rack, rack->r_ctl.rack_per_of_gp_ca, rtt_diff);
3597 		if (rack->r_ctl.rack_per_of_gp_ca > val) {
3598 			ca_red = rack->r_ctl.rack_per_of_gp_ca - val;
3599 			rack->r_ctl.rack_per_of_gp_ca = (uint16_t)val;
3600 		} else {
3601 			rack->r_ctl.rack_per_of_gp_ca = rack_per_lower_bound;
3602 			ca_red = 0;
3603 			logvar = new_per;
3604 			logvar <<= 32;
3605 			logvar |= alt;
3606 			logvar2 = (uint32_t)rtt;
3607 			logvar2 <<= 32;
3608 			logvar2 |= (uint32_t)rtt_diff;
3609 			logvar3 = rack_gp_rtt_maxmul;
3610 			logvar3 <<= 32;
3611 			logvar3 |= get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt);
3612 			rack_log_timely(rack, timely_says,
3613 					logvar2, logvar3,
3614 					logvar, __LINE__, 10);
3615 		}
3616 		if (rack_per_lower_bound > rack->r_ctl.rack_per_of_gp_ca)
3617 			rack->r_ctl.rack_per_of_gp_ca = rack_per_lower_bound;
3618 		logged |= 2;
3619 	}
3620 	if (rack->rc_gp_timely_dec_cnt < 0x7) {
3621 		rack->rc_gp_timely_dec_cnt++;
3622 		if (rack_timely_dec_clear &&
3623 		    (rack->rc_gp_timely_dec_cnt == rack_timely_dec_clear))
3624 			rack->rc_gp_timely_dec_cnt = 0;
3625 	}
3626 	logvar = ss_red;
3627 	logvar <<= 32;
3628 	logvar |= ca_red;
3629 	rack_log_timely(rack,  logged, rec_red, rack_per_lower_bound, logvar,
3630 			__LINE__, 2);
3631 }
3632 
3633 static void
3634 rack_log_rtt_shrinks(struct tcp_rack *rack, uint32_t us_cts,
3635 		     uint32_t rtt, uint32_t line, uint8_t reas)
3636 {
3637 	if (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
3638 		union tcp_log_stackspecific log;
3639 		struct timeval tv;
3640 
3641 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
3642 		log.u_bbr.flex1 = line;
3643 		log.u_bbr.flex2 = rack->r_ctl.rc_time_probertt_starts;
3644 		log.u_bbr.flex3 = rack->r_ctl.rc_lower_rtt_us_cts;
3645 		log.u_bbr.flex4 = rack->r_ctl.rack_per_of_gp_ss;
3646 		log.u_bbr.flex5 = rtt;
3647 		log.u_bbr.flex6 = rack->rc_highly_buffered;
3648 		log.u_bbr.flex6 <<= 1;
3649 		log.u_bbr.flex6 |= rack->forced_ack;
3650 		log.u_bbr.flex6 <<= 1;
3651 		log.u_bbr.flex6 |= rack->rc_gp_dyn_mul;
3652 		log.u_bbr.flex6 <<= 1;
3653 		log.u_bbr.flex6 |= rack->in_probe_rtt;
3654 		log.u_bbr.flex6 <<= 1;
3655 		log.u_bbr.flex6 |= rack->measure_saw_probe_rtt;
3656 		log.u_bbr.flex7 = rack->r_ctl.rack_per_of_gp_probertt;
3657 		log.u_bbr.pacing_gain = rack->r_ctl.rack_per_of_gp_ca;
3658 		log.u_bbr.cwnd_gain = rack->r_ctl.rack_per_of_gp_rec;
3659 		log.u_bbr.flex8 = reas;
3660 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
3661 		log.u_bbr.delRate = rack_get_bw(rack);
3662 		log.u_bbr.cur_del_rate = rack->r_ctl.rc_highest_us_rtt;
3663 		log.u_bbr.cur_del_rate <<= 32;
3664 		log.u_bbr.cur_del_rate |= rack->r_ctl.rc_lowest_us_rtt;
3665 		log.u_bbr.applimited = rack->r_ctl.rc_time_probertt_entered;
3666 		log.u_bbr.pkts_out = rack->r_ctl.rc_rtt_diff;
3667 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
3668 		log.u_bbr.epoch = rack->r_ctl.rc_gp_srtt;
3669 		log.u_bbr.lt_epoch = rack->r_ctl.rc_prev_gp_srtt;
3670 		log.u_bbr.pkt_epoch = rack->r_ctl.rc_lower_rtt_us_cts;
3671 		log.u_bbr.delivered = rack->r_ctl.rc_target_probertt_flight;
3672 		log.u_bbr.lost = get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt);
3673 		log.u_bbr.rttProp = us_cts;
3674 		log.u_bbr.rttProp <<= 32;
3675 		log.u_bbr.rttProp |= rack->r_ctl.rc_entry_gp_rtt;
3676 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
3677 		    &rack->rc_inp->inp_socket->so_rcv,
3678 		    &rack->rc_inp->inp_socket->so_snd,
3679 		    BBR_LOG_RTT_SHRINKS, 0,
3680 		    0, &log, false, &rack->r_ctl.act_rcv_time);
3681 	}
3682 }
3683 
3684 static void
3685 rack_set_prtt_target(struct tcp_rack *rack, uint32_t segsiz, uint32_t rtt)
3686 {
3687 	uint64_t bwdp;
3688 
3689 	bwdp = rack_get_bw(rack);
3690 	bwdp *= (uint64_t)rtt;
3691 	bwdp /= (uint64_t)HPTS_USEC_IN_SEC;
3692 	rack->r_ctl.rc_target_probertt_flight = roundup((uint32_t)bwdp, segsiz);
3693 	if (rack->r_ctl.rc_target_probertt_flight < (segsiz * rack_timely_min_segs)) {
3694 		/*
3695 		 * A window protocol must be able to have 4 packets
3696 		 * outstanding as the floor in order to function
3697 		 * (especially considering delayed ack :D).
3698 		 */
3699 		rack->r_ctl.rc_target_probertt_flight = (segsiz * rack_timely_min_segs);
3700 	}
3701 }
3702 
3703 static void
3704 rack_enter_probertt(struct tcp_rack *rack, uint32_t us_cts)
3705 {
3706 	/**
3707 	 * ProbeRTT is a bit different in rack_pacing than in
3708 	 * BBR. It is like BBR in that it uses the lowering of
3709 	 * the RTT as a signal that we saw something new and
3710 	 * counts from there for how long between. But it is
3711 	 * different in that its quite simple. It does not
3712 	 * play with the cwnd and wait until we get down
3713 	 * to N segments outstanding and hold that for
3714 	 * 200ms. Instead it just sets the pacing reduction
3715 	 * rate to a set percentage (70 by default) and hold
3716 	 * that for a number of recent GP Srtt's.
3717 	 */
3718 	uint32_t segsiz;
3719 
3720 	if (rack->rc_gp_dyn_mul == 0)
3721 		return;
3722 
3723 	if (rack->rc_tp->snd_max == rack->rc_tp->snd_una) {
3724 		/* We are idle */
3725 		return;
3726 	}
3727 	if ((rack->rc_tp->t_flags & TF_GPUTINPROG) &&
3728 	    SEQ_GT(rack->rc_tp->snd_una, rack->rc_tp->gput_seq)) {
3729 		/*
3730 		 * Stop the goodput now, the idea here is
3731 		 * that future measurements with in_probe_rtt
3732 		 * won't register if they are not greater so
3733 		 * we want to get what info (if any) is available
3734 		 * now.
3735 		 */
3736 		rack_do_goodput_measurement(rack->rc_tp, rack,
3737 					    rack->rc_tp->snd_una, __LINE__,
3738 					    RACK_QUALITY_PROBERTT);
3739 	}
3740 	rack->r_ctl.rack_per_of_gp_probertt = rack_per_of_gp_probertt;
3741 	rack->r_ctl.rc_time_probertt_entered = us_cts;
3742 	segsiz = min(ctf_fixed_maxseg(rack->rc_tp),
3743 		     rack->r_ctl.rc_pace_min_segs);
3744 	rack->in_probe_rtt = 1;
3745 	rack->measure_saw_probe_rtt = 1;
3746 	rack->r_ctl.rc_lower_rtt_us_cts = us_cts;
3747 	rack->r_ctl.rc_time_probertt_starts = 0;
3748 	rack->r_ctl.rc_entry_gp_rtt = rack->r_ctl.rc_gp_srtt;
3749 	if (rack_probertt_use_min_rtt_entry)
3750 		rack_set_prtt_target(rack, segsiz, get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt));
3751 	else
3752 		rack_set_prtt_target(rack, segsiz, rack->r_ctl.rc_gp_srtt);
3753 	rack_log_rtt_shrinks(rack,  us_cts,  get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt),
3754 			     __LINE__, RACK_RTTS_ENTERPROBE);
3755 }
3756 
3757 static void
3758 rack_exit_probertt(struct tcp_rack *rack, uint32_t us_cts)
3759 {
3760 	struct rack_sendmap *rsm;
3761 	uint32_t segsiz;
3762 
3763 	segsiz = min(ctf_fixed_maxseg(rack->rc_tp),
3764 		     rack->r_ctl.rc_pace_min_segs);
3765 	rack->in_probe_rtt = 0;
3766 	if ((rack->rc_tp->t_flags & TF_GPUTINPROG) &&
3767 	    SEQ_GT(rack->rc_tp->snd_una, rack->rc_tp->gput_seq)) {
3768 		/*
3769 		 * Stop the goodput now, the idea here is
3770 		 * that future measurements with in_probe_rtt
3771 		 * won't register if they are not greater so
3772 		 * we want to get what info (if any) is available
3773 		 * now.
3774 		 */
3775 		rack_do_goodput_measurement(rack->rc_tp, rack,
3776 					    rack->rc_tp->snd_una, __LINE__,
3777 					    RACK_QUALITY_PROBERTT);
3778 	} else if (rack->rc_tp->t_flags & TF_GPUTINPROG) {
3779 		/*
3780 		 * We don't have enough data to make a measurement.
3781 		 * So lets just stop and start here after exiting
3782 		 * probe-rtt. We probably are not interested in
3783 		 * the results anyway.
3784 		 */
3785 		rack->rc_tp->t_flags &= ~TF_GPUTINPROG;
3786 	}
3787 	/*
3788 	 * Measurements through the current snd_max are going
3789 	 * to be limited by the slower pacing rate.
3790 	 *
3791 	 * We need to mark these as app-limited so we
3792 	 * don't collapse the b/w.
3793 	 */
3794 	rsm = RB_MAX(rack_rb_tree_head, &rack->r_ctl.rc_mtree);
3795 	if (rsm && ((rsm->r_flags & RACK_APP_LIMITED) == 0)) {
3796 		if (rack->r_ctl.rc_app_limited_cnt == 0)
3797 			rack->r_ctl.rc_end_appl = rack->r_ctl.rc_first_appl = rsm;
3798 		else {
3799 			/*
3800 			 * Go out to the end app limited and mark
3801 			 * this new one as next and move the end_appl up
3802 			 * to this guy.
3803 			 */
3804 			if (rack->r_ctl.rc_end_appl)
3805 				rack->r_ctl.rc_end_appl->r_nseq_appl = rsm->r_start;
3806 			rack->r_ctl.rc_end_appl = rsm;
3807 		}
3808 		rsm->r_flags |= RACK_APP_LIMITED;
3809 		rack->r_ctl.rc_app_limited_cnt++;
3810 	}
3811 	/*
3812 	 * Now, we need to examine our pacing rate multipliers.
3813 	 * If its under 100%, we need to kick it back up to
3814 	 * 100%. We also don't let it be over our "max" above
3815 	 * the actual rate i.e. 100% + rack_clamp_atexit_prtt.
3816 	 * Note setting clamp_atexit_prtt to 0 has the effect
3817 	 * of setting CA/SS to 100% always at exit (which is
3818 	 * the default behavior).
3819 	 */
3820 	if (rack_probertt_clear_is) {
3821 		rack->rc_gp_incr = 0;
3822 		rack->rc_gp_bwred = 0;
3823 		rack->rc_gp_timely_inc_cnt = 0;
3824 		rack->rc_gp_timely_dec_cnt = 0;
3825 	}
3826 	/* Do we do any clamping at exit? */
3827 	if (rack->rc_highly_buffered && rack_atexit_prtt_hbp) {
3828 		rack->r_ctl.rack_per_of_gp_ca = rack_atexit_prtt_hbp;
3829 		rack->r_ctl.rack_per_of_gp_ss = rack_atexit_prtt_hbp;
3830 	}
3831 	if ((rack->rc_highly_buffered == 0) && rack_atexit_prtt) {
3832 		rack->r_ctl.rack_per_of_gp_ca = rack_atexit_prtt;
3833 		rack->r_ctl.rack_per_of_gp_ss = rack_atexit_prtt;
3834 	}
3835 	/*
3836 	 * Lets set rtt_diff to 0, so that we will get a "boost"
3837 	 * after exiting.
3838 	 */
3839 	rack->r_ctl.rc_rtt_diff = 0;
3840 
3841 	/* Clear all flags so we start fresh */
3842 	rack->rc_tp->t_bytes_acked = 0;
3843 	rack->rc_tp->ccv->flags &= ~CCF_ABC_SENTAWND;
3844 	/*
3845 	 * If configured to, set the cwnd and ssthresh to
3846 	 * our targets.
3847 	 */
3848 	if (rack_probe_rtt_sets_cwnd) {
3849 		uint64_t ebdp;
3850 		uint32_t setto;
3851 
3852 		/* Set ssthresh so we get into CA once we hit our target */
3853 		if (rack_probertt_use_min_rtt_exit == 1) {
3854 			/* Set to min rtt */
3855 			rack_set_prtt_target(rack, segsiz,
3856 					     get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt));
3857 		} else if (rack_probertt_use_min_rtt_exit == 2) {
3858 			/* Set to current gp rtt */
3859 			rack_set_prtt_target(rack, segsiz,
3860 					     rack->r_ctl.rc_gp_srtt);
3861 		} else if (rack_probertt_use_min_rtt_exit == 3) {
3862 			/* Set to entry gp rtt */
3863 			rack_set_prtt_target(rack, segsiz,
3864 					     rack->r_ctl.rc_entry_gp_rtt);
3865 		} else {
3866 			uint64_t sum;
3867 			uint32_t setval;
3868 
3869 			sum = rack->r_ctl.rc_entry_gp_rtt;
3870 			sum *= 10;
3871 			sum /= (uint64_t)(max(1, rack->r_ctl.rc_gp_srtt));
3872 			if (sum >= 20) {
3873 				/*
3874 				 * A highly buffered path needs
3875 				 * cwnd space for timely to work.
3876 				 * Lets set things up as if
3877 				 * we are heading back here again.
3878 				 */
3879 				setval = rack->r_ctl.rc_entry_gp_rtt;
3880 			} else if (sum >= 15) {
3881 				/*
3882 				 * Lets take the smaller of the
3883 				 * two since we are just somewhat
3884 				 * buffered.
3885 				 */
3886 				setval = rack->r_ctl.rc_gp_srtt;
3887 				if (setval > rack->r_ctl.rc_entry_gp_rtt)
3888 					setval = rack->r_ctl.rc_entry_gp_rtt;
3889 			} else {
3890 				/*
3891 				 * Here we are not highly buffered
3892 				 * and should pick the min we can to
3893 				 * keep from causing loss.
3894 				 */
3895 				setval = get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt);
3896 			}
3897 			rack_set_prtt_target(rack, segsiz,
3898 					     setval);
3899 		}
3900 		if (rack_probe_rtt_sets_cwnd > 1) {
3901 			/* There is a percentage here to boost */
3902 			ebdp = rack->r_ctl.rc_target_probertt_flight;
3903 			ebdp *= rack_probe_rtt_sets_cwnd;
3904 			ebdp /= 100;
3905 			setto = rack->r_ctl.rc_target_probertt_flight + ebdp;
3906 		} else
3907 			setto = rack->r_ctl.rc_target_probertt_flight;
3908 		rack->rc_tp->snd_cwnd = roundup(setto, segsiz);
3909 		if (rack->rc_tp->snd_cwnd < (segsiz * rack_timely_min_segs)) {
3910 			/* Enforce a min */
3911 			rack->rc_tp->snd_cwnd = segsiz * rack_timely_min_segs;
3912 		}
3913 		/* If we set in the cwnd also set the ssthresh point so we are in CA */
3914 		rack->rc_tp->snd_ssthresh = (rack->rc_tp->snd_cwnd - 1);
3915 	}
3916 	rack_log_rtt_shrinks(rack,  us_cts,
3917 			     get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt),
3918 			     __LINE__, RACK_RTTS_EXITPROBE);
3919 	/* Clear times last so log has all the info */
3920 	rack->r_ctl.rc_probertt_sndmax_atexit = rack->rc_tp->snd_max;
3921 	rack->r_ctl.rc_time_probertt_entered = us_cts;
3922 	rack->r_ctl.rc_time_probertt_starts = rack->r_ctl.rc_lower_rtt_us_cts = us_cts;
3923 	rack->r_ctl.rc_time_of_last_probertt = us_cts;
3924 }
3925 
3926 static void
3927 rack_check_probe_rtt(struct tcp_rack *rack, uint32_t us_cts)
3928 {
3929 	/* Check in on probe-rtt */
3930 	if (rack->rc_gp_filled == 0) {
3931 		/* We do not do p-rtt unless we have gp measurements */
3932 		return;
3933 	}
3934 	if (rack->in_probe_rtt) {
3935 		uint64_t no_overflow;
3936 		uint32_t endtime, must_stay;
3937 
3938 		if (rack->r_ctl.rc_went_idle_time &&
3939 		    ((us_cts - rack->r_ctl.rc_went_idle_time) > rack_min_probertt_hold)) {
3940 			/*
3941 			 * We went idle during prtt, just exit now.
3942 			 */
3943 			rack_exit_probertt(rack, us_cts);
3944 		} else if (rack_probe_rtt_safety_val &&
3945 		    TSTMP_GT(us_cts, rack->r_ctl.rc_time_probertt_entered) &&
3946 		    ((us_cts - rack->r_ctl.rc_time_probertt_entered) > rack_probe_rtt_safety_val)) {
3947 			/*
3948 			 * Probe RTT safety value triggered!
3949 			 */
3950 			rack_log_rtt_shrinks(rack,  us_cts,
3951 					     get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt),
3952 					     __LINE__, RACK_RTTS_SAFETY);
3953 			rack_exit_probertt(rack, us_cts);
3954 		}
3955 		/* Calculate the max we will wait */
3956 		endtime = rack->r_ctl.rc_time_probertt_entered + (rack->r_ctl.rc_gp_srtt * rack_max_drain_wait);
3957 		if (rack->rc_highly_buffered)
3958 			endtime += (rack->r_ctl.rc_gp_srtt * rack_max_drain_hbp);
3959 		/* Calculate the min we must wait */
3960 		must_stay = rack->r_ctl.rc_time_probertt_entered + (rack->r_ctl.rc_gp_srtt * rack_must_drain);
3961 		if ((ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked) > rack->r_ctl.rc_target_probertt_flight) &&
3962 		    TSTMP_LT(us_cts, endtime)) {
3963 			uint32_t calc;
3964 			/* Do we lower more? */
3965 no_exit:
3966 			if (TSTMP_GT(us_cts, rack->r_ctl.rc_time_probertt_entered))
3967 				calc = us_cts - rack->r_ctl.rc_time_probertt_entered;
3968 			else
3969 				calc = 0;
3970 			calc /= max(rack->r_ctl.rc_gp_srtt, 1);
3971 			if (calc) {
3972 				/* Maybe */
3973 				calc *= rack_per_of_gp_probertt_reduce;
3974 				rack->r_ctl.rack_per_of_gp_probertt = rack_per_of_gp_probertt - calc;
3975 				/* Limit it too */
3976 				if (rack->r_ctl.rack_per_of_gp_probertt < rack_per_of_gp_lowthresh)
3977 					rack->r_ctl.rack_per_of_gp_probertt = rack_per_of_gp_lowthresh;
3978 			}
3979 			/* We must reach target or the time set */
3980 			return;
3981 		}
3982 		if (rack->r_ctl.rc_time_probertt_starts == 0) {
3983 			if ((TSTMP_LT(us_cts, must_stay) &&
3984 			     rack->rc_highly_buffered) ||
3985 			     (ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked) >
3986 			      rack->r_ctl.rc_target_probertt_flight)) {
3987 				/* We are not past the must_stay time */
3988 				goto no_exit;
3989 			}
3990 			rack_log_rtt_shrinks(rack,  us_cts,
3991 					     get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt),
3992 					     __LINE__, RACK_RTTS_REACHTARGET);
3993 			rack->r_ctl.rc_time_probertt_starts = us_cts;
3994 			if (rack->r_ctl.rc_time_probertt_starts == 0)
3995 				rack->r_ctl.rc_time_probertt_starts = 1;
3996 			/* Restore back to our rate we want to pace at in prtt */
3997 			rack->r_ctl.rack_per_of_gp_probertt = rack_per_of_gp_probertt;
3998 		}
3999 		/*
4000 		 * Setup our end time, some number of gp_srtts plus 200ms.
4001 		 */
4002 		no_overflow = ((uint64_t)rack->r_ctl.rc_gp_srtt *
4003 			       (uint64_t)rack_probertt_gpsrtt_cnt_mul);
4004 		if (rack_probertt_gpsrtt_cnt_div)
4005 			endtime = (uint32_t)(no_overflow / (uint64_t)rack_probertt_gpsrtt_cnt_div);
4006 		else
4007 			endtime = 0;
4008 		endtime += rack_min_probertt_hold;
4009 		endtime += rack->r_ctl.rc_time_probertt_starts;
4010 		if (TSTMP_GEQ(us_cts,  endtime)) {
4011 			/* yes, exit probertt */
4012 			rack_exit_probertt(rack, us_cts);
4013 		}
4014 
4015 	} else if ((us_cts - rack->r_ctl.rc_lower_rtt_us_cts) >= rack_time_between_probertt) {
4016 		/* Go into probertt, its been too long since we went lower */
4017 		rack_enter_probertt(rack, us_cts);
4018 	}
4019 }
4020 
4021 static void
4022 rack_update_multiplier(struct tcp_rack *rack, int32_t timely_says, uint64_t last_bw_est,
4023 		       uint32_t rtt, int32_t rtt_diff)
4024 {
4025 	uint64_t cur_bw, up_bnd, low_bnd, subfr;
4026 	uint32_t losses;
4027 
4028 	if ((rack->rc_gp_dyn_mul == 0) ||
4029 	    (rack->use_fixed_rate) ||
4030 	    (rack->in_probe_rtt) ||
4031 	    (rack->rc_always_pace == 0)) {
4032 		/* No dynamic GP multipler in play */
4033 		return;
4034 	}
4035 	losses = rack->r_ctl.rc_loss_count - rack->r_ctl.rc_loss_at_start;
4036 	cur_bw = rack_get_bw(rack);
4037 	/* Calculate our up and down range */
4038 	up_bnd = rack->r_ctl.last_gp_comp_bw * (uint64_t)rack_gp_per_bw_mul_up;
4039 	up_bnd /= 100;
4040 	up_bnd += rack->r_ctl.last_gp_comp_bw;
4041 
4042 	subfr = (uint64_t)rack->r_ctl.last_gp_comp_bw * (uint64_t)rack_gp_per_bw_mul_down;
4043 	subfr /= 100;
4044 	low_bnd = rack->r_ctl.last_gp_comp_bw - subfr;
4045 	if ((timely_says == 2) && (rack->r_ctl.rc_no_push_at_mrtt)) {
4046 		/*
4047 		 * This is the case where our RTT is above
4048 		 * the max target and we have been configured
4049 		 * to just do timely no bonus up stuff in that case.
4050 		 *
4051 		 * There are two configurations, set to 1, and we
4052 		 * just do timely if we are over our max. If its
4053 		 * set above 1 then we slam the multipliers down
4054 		 * to 100 and then decrement per timely.
4055 		 */
4056 		rack_log_timely(rack,  timely_says, cur_bw, low_bnd, up_bnd,
4057 				__LINE__, 3);
4058 		if (rack->r_ctl.rc_no_push_at_mrtt > 1)
4059 			rack_validate_multipliers_at_or_below_100(rack);
4060 		rack_decrease_bw_mul(rack, timely_says, rtt, rtt_diff);
4061 	} else if ((last_bw_est < low_bnd) && !losses) {
4062 		/*
4063 		 * We are decreasing this is a bit complicated this
4064 		 * means we are loosing ground. This could be
4065 		 * because another flow entered and we are competing
4066 		 * for b/w with it. This will push the RTT up which
4067 		 * makes timely unusable unless we want to get shoved
4068 		 * into a corner and just be backed off (the age
4069 		 * old problem with delay based CC).
4070 		 *
4071 		 * On the other hand if it was a route change we
4072 		 * would like to stay somewhat contained and not
4073 		 * blow out the buffers.
4074 		 */
4075 		rack_log_timely(rack,  timely_says, cur_bw, low_bnd, up_bnd,
4076 				__LINE__, 3);
4077 		rack->r_ctl.last_gp_comp_bw = cur_bw;
4078 		if (rack->rc_gp_bwred == 0) {
4079 			/* Go into reduction counting */
4080 			rack->rc_gp_bwred = 1;
4081 			rack->rc_gp_timely_dec_cnt = 0;
4082 		}
4083 		if ((rack->rc_gp_timely_dec_cnt < rack_timely_max_push_drop) ||
4084 		    (timely_says == 0)) {
4085 			/*
4086 			 * Push another time with a faster pacing
4087 			 * to try to gain back (we include override to
4088 			 * get a full raise factor).
4089 			 */
4090 			if ((rack->rc_gp_saw_ca && rack->r_ctl.rack_per_of_gp_ca <= rack_down_raise_thresh) ||
4091 			    (rack->rc_gp_saw_ss && rack->r_ctl.rack_per_of_gp_ss <= rack_down_raise_thresh) ||
4092 			    (timely_says == 0) ||
4093 			    (rack_down_raise_thresh == 0)) {
4094 				/*
4095 				 * Do an override up in b/w if we were
4096 				 * below the threshold or if the threshold
4097 				 * is zero we always do the raise.
4098 				 */
4099 				rack_increase_bw_mul(rack, timely_says, cur_bw, last_bw_est, 1);
4100 			} else {
4101 				/* Log it stays the same */
4102 				rack_log_timely(rack,  0, last_bw_est, low_bnd, 0,
4103 						__LINE__, 11);
4104 			}
4105 			rack->rc_gp_timely_dec_cnt++;
4106 			/* We are not incrementing really no-count */
4107 			rack->rc_gp_incr = 0;
4108 			rack->rc_gp_timely_inc_cnt = 0;
4109 		} else {
4110 			/*
4111 			 * Lets just use the RTT
4112 			 * information and give up
4113 			 * pushing.
4114 			 */
4115 			goto use_timely;
4116 		}
4117 	} else if ((timely_says != 2) &&
4118 		    !losses &&
4119 		    (last_bw_est > up_bnd)) {
4120 		/*
4121 		 * We are increasing b/w lets keep going, updating
4122 		 * our b/w and ignoring any timely input, unless
4123 		 * of course we are at our max raise (if there is one).
4124 		 */
4125 
4126 		rack_log_timely(rack,  timely_says, cur_bw, low_bnd, up_bnd,
4127 				__LINE__, 3);
4128 		rack->r_ctl.last_gp_comp_bw = cur_bw;
4129 		if (rack->rc_gp_saw_ss &&
4130 		    rack_per_upper_bound_ss &&
4131 		     (rack->r_ctl.rack_per_of_gp_ss == rack_per_upper_bound_ss)) {
4132 			    /*
4133 			     * In cases where we can't go higher
4134 			     * we should just use timely.
4135 			     */
4136 			    goto use_timely;
4137 		}
4138 		if (rack->rc_gp_saw_ca &&
4139 		    rack_per_upper_bound_ca &&
4140 		    (rack->r_ctl.rack_per_of_gp_ca == rack_per_upper_bound_ca)) {
4141 			    /*
4142 			     * In cases where we can't go higher
4143 			     * we should just use timely.
4144 			     */
4145 			    goto use_timely;
4146 		}
4147 		rack->rc_gp_bwred = 0;
4148 		rack->rc_gp_timely_dec_cnt = 0;
4149 		/* You get a set number of pushes if timely is trying to reduce */
4150 		if ((rack->rc_gp_incr < rack_timely_max_push_rise) || (timely_says == 0)) {
4151 			rack_increase_bw_mul(rack, timely_says, cur_bw, last_bw_est, 0);
4152 		} else {
4153 			/* Log it stays the same */
4154 			rack_log_timely(rack,  0, last_bw_est, up_bnd, 0,
4155 			    __LINE__, 12);
4156 		}
4157 		return;
4158 	} else {
4159 		/*
4160 		 * We are staying between the lower and upper range bounds
4161 		 * so use timely to decide.
4162 		 */
4163 		rack_log_timely(rack,  timely_says, cur_bw, low_bnd, up_bnd,
4164 				__LINE__, 3);
4165 use_timely:
4166 		if (timely_says) {
4167 			rack->rc_gp_incr = 0;
4168 			rack->rc_gp_timely_inc_cnt = 0;
4169 			if ((rack->rc_gp_timely_dec_cnt < rack_timely_max_push_drop) &&
4170 			    !losses &&
4171 			    (last_bw_est < low_bnd)) {
4172 				/* We are loosing ground */
4173 				rack_increase_bw_mul(rack, timely_says, cur_bw, last_bw_est, 0);
4174 				rack->rc_gp_timely_dec_cnt++;
4175 				/* We are not incrementing really no-count */
4176 				rack->rc_gp_incr = 0;
4177 				rack->rc_gp_timely_inc_cnt = 0;
4178 			} else
4179 				rack_decrease_bw_mul(rack, timely_says, rtt, rtt_diff);
4180 		} else {
4181 			rack->rc_gp_bwred = 0;
4182 			rack->rc_gp_timely_dec_cnt = 0;
4183 			rack_increase_bw_mul(rack, timely_says, cur_bw, last_bw_est, 0);
4184 		}
4185 	}
4186 }
4187 
4188 static int32_t
4189 rack_make_timely_judgement(struct tcp_rack *rack, uint32_t rtt, int32_t rtt_diff, uint32_t prev_rtt)
4190 {
4191 	int32_t timely_says;
4192 	uint64_t log_mult, log_rtt_a_diff;
4193 
4194 	log_rtt_a_diff = rtt;
4195 	log_rtt_a_diff <<= 32;
4196 	log_rtt_a_diff |= (uint32_t)rtt_diff;
4197 	if (rtt >= (get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt) *
4198 		    rack_gp_rtt_maxmul)) {
4199 		/* Reduce the b/w multipler */
4200 		timely_says = 2;
4201 		log_mult = get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt) * rack_gp_rtt_maxmul;
4202 		log_mult <<= 32;
4203 		log_mult |= prev_rtt;
4204 		rack_log_timely(rack,  timely_says, log_mult,
4205 				get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt),
4206 				log_rtt_a_diff, __LINE__, 4);
4207 	} else if (rtt <= (get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt) +
4208 			   ((get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt) * rack_gp_rtt_minmul) /
4209 			    max(rack_gp_rtt_mindiv , 1)))) {
4210 		/* Increase the b/w multipler */
4211 		log_mult = get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt) +
4212 			((get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt) * rack_gp_rtt_minmul) /
4213 			 max(rack_gp_rtt_mindiv , 1));
4214 		log_mult <<= 32;
4215 		log_mult |= prev_rtt;
4216 		timely_says = 0;
4217 		rack_log_timely(rack,  timely_says, log_mult ,
4218 				get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt),
4219 				log_rtt_a_diff, __LINE__, 5);
4220 	} else {
4221 		/*
4222 		 * Use a gradient to find it the timely gradient
4223 		 * is:
4224 		 * grad = rc_rtt_diff / min_rtt;
4225 		 *
4226 		 * anything below or equal to 0 will be
4227 		 * a increase indication. Anything above
4228 		 * zero is a decrease. Note we take care
4229 		 * of the actual gradient calculation
4230 		 * in the reduction (its not needed for
4231 		 * increase).
4232 		 */
4233 		log_mult = prev_rtt;
4234 		if (rtt_diff <= 0) {
4235 			/*
4236 			 * Rttdiff is less than zero, increase the
4237 			 * b/w multipler (its 0 or negative)
4238 			 */
4239 			timely_says = 0;
4240 			rack_log_timely(rack,  timely_says, log_mult,
4241 					get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt), log_rtt_a_diff, __LINE__, 6);
4242 		} else {
4243 			/* Reduce the b/w multipler */
4244 			timely_says = 1;
4245 			rack_log_timely(rack,  timely_says, log_mult,
4246 					get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt), log_rtt_a_diff, __LINE__, 7);
4247 		}
4248 	}
4249 	return (timely_says);
4250 }
4251 
4252 static void
4253 rack_do_goodput_measurement(struct tcpcb *tp, struct tcp_rack *rack,
4254 			    tcp_seq th_ack, int line, uint8_t quality)
4255 {
4256 	uint64_t tim, bytes_ps, ltim, stim, utim;
4257 	uint32_t segsiz, bytes, reqbytes, us_cts;
4258 	int32_t gput, new_rtt_diff, timely_says;
4259 	uint64_t  resid_bw, subpart = 0, addpart = 0, srtt;
4260 	int did_add = 0;
4261 
4262 	us_cts = tcp_tv_to_usectick(&rack->r_ctl.act_rcv_time);
4263 	segsiz = min(ctf_fixed_maxseg(tp), rack->r_ctl.rc_pace_min_segs);
4264 	if (TSTMP_GEQ(us_cts, tp->gput_ts))
4265 		tim = us_cts - tp->gput_ts;
4266 	else
4267 		tim = 0;
4268 	if (rack->r_ctl.rc_gp_cumack_ts > rack->r_ctl.rc_gp_output_ts)
4269 		stim = rack->r_ctl.rc_gp_cumack_ts - rack->r_ctl.rc_gp_output_ts;
4270 	else
4271 		stim = 0;
4272 	/*
4273 	 * Use the larger of the send time or ack time. This prevents us
4274 	 * from being influenced by ack artifacts to come up with too
4275 	 * high of measurement. Note that since we are spanning over many more
4276 	 * bytes in most of our measurements hopefully that is less likely to
4277 	 * occur.
4278 	 */
4279 	if (tim > stim)
4280 		utim = max(tim, 1);
4281 	else
4282 		utim = max(stim, 1);
4283 	/* Lets get a msec time ltim too for the old stuff */
4284 	ltim = max(1, (utim / HPTS_USEC_IN_MSEC));
4285 	gput = (((uint64_t) (th_ack - tp->gput_seq)) << 3) / ltim;
4286 	reqbytes = min(rc_init_window(rack), (MIN_GP_WIN * segsiz));
4287 	if ((tim == 0) && (stim == 0)) {
4288 		/*
4289 		 * Invalid measurement time, maybe
4290 		 * all on one ack/one send?
4291 		 */
4292 		bytes = 0;
4293 		bytes_ps = 0;
4294 		rack_log_pacing_delay_calc(rack, bytes_ps, reqbytes,
4295 					   0, 0, 0, 10, __LINE__, NULL, quality);
4296 		goto skip_measurement;
4297 	}
4298 	if (rack->r_ctl.rc_gp_lowrtt == 0xffffffff) {
4299 		/* We never made a us_rtt measurement? */
4300 		bytes = 0;
4301 		bytes_ps = 0;
4302 		rack_log_pacing_delay_calc(rack, bytes_ps, reqbytes,
4303 					   0, 0, 0, 10, __LINE__, NULL, quality);
4304 		goto skip_measurement;
4305 	}
4306 	/*
4307 	 * Calculate the maximum possible b/w this connection
4308 	 * could have. We base our calculation on the lowest
4309 	 * rtt we have seen during the measurement and the
4310 	 * largest rwnd the client has given us in that time. This
4311 	 * forms a BDP that is the maximum that we could ever
4312 	 * get to the client. Anything larger is not valid.
4313 	 *
4314 	 * I originally had code here that rejected measurements
4315 	 * where the time was less than 1/2 the latest us_rtt.
4316 	 * But after thinking on that I realized its wrong since
4317 	 * say you had a 150Mbps or even 1Gbps link, and you
4318 	 * were a long way away.. example I am in Europe (100ms rtt)
4319 	 * talking to my 1Gbps link in S.C. Now measuring say 150,000
4320 	 * bytes my time would be 1.2ms, and yet my rtt would say
4321 	 * the measurement was invalid the time was < 50ms. The
4322 	 * same thing is true for 150Mb (8ms of time).
4323 	 *
4324 	 * A better way I realized is to look at what the maximum
4325 	 * the connection could possibly do. This is gated on
4326 	 * the lowest RTT we have seen and the highest rwnd.
4327 	 * We should in theory never exceed that, if we are
4328 	 * then something on the path is storing up packets
4329 	 * and then feeding them all at once to our endpoint
4330 	 * messing up our measurement.
4331 	 */
4332 	rack->r_ctl.last_max_bw = rack->r_ctl.rc_gp_high_rwnd;
4333 	rack->r_ctl.last_max_bw *= HPTS_USEC_IN_SEC;
4334 	rack->r_ctl.last_max_bw /= rack->r_ctl.rc_gp_lowrtt;
4335 	if (SEQ_LT(th_ack, tp->gput_seq)) {
4336 		/* No measurement can be made */
4337 		bytes = 0;
4338 		bytes_ps = 0;
4339 		rack_log_pacing_delay_calc(rack, bytes_ps, reqbytes,
4340 					   0, 0, 0, 10, __LINE__, NULL, quality);
4341 		goto skip_measurement;
4342 	} else
4343 		bytes = (th_ack - tp->gput_seq);
4344 	bytes_ps = (uint64_t)bytes;
4345 	/*
4346 	 * Don't measure a b/w for pacing unless we have gotten at least
4347 	 * an initial windows worth of data in this measurement interval.
4348 	 *
4349 	 * Small numbers of bytes get badly influenced by delayed ack and
4350 	 * other artifacts. Note we take the initial window or our
4351 	 * defined minimum GP (defaulting to 10 which hopefully is the
4352 	 * IW).
4353 	 */
4354 	if (rack->rc_gp_filled == 0) {
4355 		/*
4356 		 * The initial estimate is special. We
4357 		 * have blasted out an IW worth of packets
4358 		 * without a real valid ack ts results. We
4359 		 * then setup the app_limited_needs_set flag,
4360 		 * this should get the first ack in (probably 2
4361 		 * MSS worth) to be recorded as the timestamp.
4362 		 * We thus allow a smaller number of bytes i.e.
4363 		 * IW - 2MSS.
4364 		 */
4365 		reqbytes -= (2 * segsiz);
4366 		/* Also lets fill previous for our first measurement to be neutral */
4367 		rack->r_ctl.rc_prev_gp_srtt = rack->r_ctl.rc_gp_srtt;
4368 	}
4369 	if ((bytes_ps < reqbytes) || rack->app_limited_needs_set) {
4370 		rack_log_pacing_delay_calc(rack, bytes_ps, reqbytes,
4371 					   rack->r_ctl.rc_app_limited_cnt,
4372 					   0, 0, 10, __LINE__, NULL, quality);
4373 		goto skip_measurement;
4374 	}
4375 	/*
4376 	 * We now need to calculate the Timely like status so
4377 	 * we can update (possibly) the b/w multipliers.
4378 	 */
4379 	new_rtt_diff = (int32_t)rack->r_ctl.rc_gp_srtt - (int32_t)rack->r_ctl.rc_prev_gp_srtt;
4380 	if (rack->rc_gp_filled == 0) {
4381 		/* No previous reading */
4382 		rack->r_ctl.rc_rtt_diff = new_rtt_diff;
4383 	} else {
4384 		if (rack->measure_saw_probe_rtt == 0) {
4385 			/*
4386 			 * We don't want a probertt to be counted
4387 			 * since it will be negative incorrectly. We
4388 			 * expect to be reducing the RTT when we
4389 			 * pace at a slower rate.
4390 			 */
4391 			rack->r_ctl.rc_rtt_diff -= (rack->r_ctl.rc_rtt_diff / 8);
4392 			rack->r_ctl.rc_rtt_diff += (new_rtt_diff / 8);
4393 		}
4394 	}
4395 	timely_says = rack_make_timely_judgement(rack,
4396 		rack->r_ctl.rc_gp_srtt,
4397 		rack->r_ctl.rc_rtt_diff,
4398 	        rack->r_ctl.rc_prev_gp_srtt
4399 		);
4400 	bytes_ps *= HPTS_USEC_IN_SEC;
4401 	bytes_ps /= utim;
4402 	if (bytes_ps > rack->r_ctl.last_max_bw) {
4403 		/*
4404 		 * Something is on path playing
4405 		 * since this b/w is not possible based
4406 		 * on our BDP (highest rwnd and lowest rtt
4407 		 * we saw in the measurement window).
4408 		 *
4409 		 * Another option here would be to
4410 		 * instead skip the measurement.
4411 		 */
4412 		rack_log_pacing_delay_calc(rack, bytes, reqbytes,
4413 					   bytes_ps, rack->r_ctl.last_max_bw, 0,
4414 					   11, __LINE__, NULL, quality);
4415 		bytes_ps = rack->r_ctl.last_max_bw;
4416 	}
4417 	/* We store gp for b/w in bytes per second */
4418 	if (rack->rc_gp_filled == 0) {
4419 		/* Initial measurment */
4420 		if (bytes_ps) {
4421 			rack->r_ctl.gp_bw = bytes_ps;
4422 			rack->rc_gp_filled = 1;
4423 			rack->r_ctl.num_measurements = 1;
4424 			rack_set_pace_segments(rack->rc_tp, rack, __LINE__, NULL);
4425 		} else {
4426 			rack_log_pacing_delay_calc(rack, bytes_ps, reqbytes,
4427 						   rack->r_ctl.rc_app_limited_cnt,
4428 						   0, 0, 10, __LINE__, NULL, quality);
4429 		}
4430 		if (rack->rc_inp->inp_in_hpts &&
4431 		    (rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT)) {
4432 			/*
4433 			 * Ok we can't trust the pacer in this case
4434 			 * where we transition from un-paced to paced.
4435 			 * Or for that matter when the burst mitigation
4436 			 * was making a wild guess and got it wrong.
4437 			 * Stop the pacer and clear up all the aggregate
4438 			 * delays etc.
4439 			 */
4440 			tcp_hpts_remove(rack->rc_inp, HPTS_REMOVE_OUTPUT);
4441 			rack->r_ctl.rc_hpts_flags = 0;
4442 			rack->r_ctl.rc_last_output_to = 0;
4443 		}
4444 		did_add = 2;
4445 	} else if (rack->r_ctl.num_measurements < RACK_REQ_AVG) {
4446 		/* Still a small number run an average */
4447 		rack->r_ctl.gp_bw += bytes_ps;
4448 		addpart = rack->r_ctl.num_measurements;
4449 		rack->r_ctl.num_measurements++;
4450 		if (rack->r_ctl.num_measurements >= RACK_REQ_AVG) {
4451 			/* We have collected enought to move forward */
4452 			rack->r_ctl.gp_bw /= (uint64_t)rack->r_ctl.num_measurements;
4453 		}
4454 		did_add = 3;
4455 	} else {
4456 		/*
4457 		 * We want to take 1/wma of the goodput and add in to 7/8th
4458 		 * of the old value weighted by the srtt. So if your measurement
4459 		 * period is say 2 SRTT's long you would get 1/4 as the
4460 		 * value, if it was like 1/2 SRTT then you would get 1/16th.
4461 		 *
4462 		 * But we must be careful not to take too much i.e. if the
4463 		 * srtt is say 20ms and the measurement is taken over
4464 		 * 400ms our weight would be 400/20 i.e. 20. On the
4465 		 * other hand if we get a measurement over 1ms with a
4466 		 * 10ms rtt we only want to take a much smaller portion.
4467 		 */
4468 		if (rack->r_ctl.num_measurements < 0xff) {
4469 			rack->r_ctl.num_measurements++;
4470 		}
4471 		srtt = (uint64_t)tp->t_srtt;
4472 		if (srtt == 0) {
4473 			/*
4474 			 * Strange why did t_srtt go back to zero?
4475 			 */
4476 			if (rack->r_ctl.rc_rack_min_rtt)
4477 				srtt = rack->r_ctl.rc_rack_min_rtt;
4478 			else
4479 				srtt = HPTS_USEC_IN_MSEC;
4480 		}
4481 		/*
4482 		 * XXXrrs: Note for reviewers, in playing with
4483 		 * dynamic pacing I discovered this GP calculation
4484 		 * as done originally leads to some undesired results.
4485 		 * Basically you can get longer measurements contributing
4486 		 * too much to the WMA. Thus I changed it if you are doing
4487 		 * dynamic adjustments to only do the aportioned adjustment
4488 		 * if we have a very small (time wise) measurement. Longer
4489 		 * measurements just get there weight (defaulting to 1/8)
4490 		 * add to the WMA. We may want to think about changing
4491 		 * this to always do that for both sides i.e. dynamic
4492 		 * and non-dynamic... but considering lots of folks
4493 		 * were playing with this I did not want to change the
4494 		 * calculation per.se. without your thoughts.. Lawerence?
4495 		 * Peter??
4496 		 */
4497 		if (rack->rc_gp_dyn_mul == 0) {
4498 			subpart = rack->r_ctl.gp_bw * utim;
4499 			subpart /= (srtt * 8);
4500 			if (subpart < (rack->r_ctl.gp_bw / 2)) {
4501 				/*
4502 				 * The b/w update takes no more
4503 				 * away then 1/2 our running total
4504 				 * so factor it in.
4505 				 */
4506 				addpart = bytes_ps * utim;
4507 				addpart /= (srtt * 8);
4508 			} else {
4509 				/*
4510 				 * Don't allow a single measurement
4511 				 * to account for more than 1/2 of the
4512 				 * WMA. This could happen on a retransmission
4513 				 * where utim becomes huge compared to
4514 				 * srtt (multiple retransmissions when using
4515 				 * the sending rate which factors in all the
4516 				 * transmissions from the first one).
4517 				 */
4518 				subpart = rack->r_ctl.gp_bw / 2;
4519 				addpart = bytes_ps / 2;
4520 			}
4521 			resid_bw = rack->r_ctl.gp_bw - subpart;
4522 			rack->r_ctl.gp_bw = resid_bw + addpart;
4523 			did_add = 1;
4524 		} else {
4525 			if ((utim / srtt) <= 1) {
4526 				/*
4527 				 * The b/w update was over a small period
4528 				 * of time. The idea here is to prevent a small
4529 				 * measurement time period from counting
4530 				 * too much. So we scale it based on the
4531 				 * time so it attributes less than 1/rack_wma_divisor
4532 				 * of its measurement.
4533 				 */
4534 				subpart = rack->r_ctl.gp_bw * utim;
4535 				subpart /= (srtt * rack_wma_divisor);
4536 				addpart = bytes_ps * utim;
4537 				addpart /= (srtt * rack_wma_divisor);
4538 			} else {
4539 				/*
4540 				 * The scaled measurement was long
4541 				 * enough so lets just add in the
4542 				 * portion of the measurment i.e. 1/rack_wma_divisor
4543 				 */
4544 				subpart = rack->r_ctl.gp_bw / rack_wma_divisor;
4545 				addpart = bytes_ps / rack_wma_divisor;
4546 			}
4547 			if ((rack->measure_saw_probe_rtt == 0) ||
4548 		            (bytes_ps > rack->r_ctl.gp_bw)) {
4549 				/*
4550 				 * For probe-rtt we only add it in
4551 				 * if its larger, all others we just
4552 				 * add in.
4553 				 */
4554 				did_add = 1;
4555 				resid_bw = rack->r_ctl.gp_bw - subpart;
4556 				rack->r_ctl.gp_bw = resid_bw + addpart;
4557 			}
4558 		}
4559 	}
4560 	if ((rack->gp_ready == 0) &&
4561 	    (rack->r_ctl.num_measurements >= rack->r_ctl.req_measurements)) {
4562 		/* We have enough measurements now */
4563 		rack->gp_ready = 1;
4564 		rack_set_cc_pacing(rack);
4565 		if (rack->defer_options)
4566 			rack_apply_deferred_options(rack);
4567 	}
4568 	rack_log_pacing_delay_calc(rack, subpart, addpart, bytes_ps, stim,
4569 				   rack_get_bw(rack), 22, did_add, NULL, quality);
4570 	/* We do not update any multipliers if we are in or have seen a probe-rtt */
4571 	if ((rack->measure_saw_probe_rtt == 0) && rack->rc_gp_rtt_set)
4572 		rack_update_multiplier(rack, timely_says, bytes_ps,
4573 				       rack->r_ctl.rc_gp_srtt,
4574 				       rack->r_ctl.rc_rtt_diff);
4575 	rack_log_pacing_delay_calc(rack, bytes, tim, bytes_ps, stim,
4576 				   rack_get_bw(rack), 3, line, NULL, quality);
4577 	/* reset the gp srtt and setup the new prev */
4578 	rack->r_ctl.rc_prev_gp_srtt = rack->r_ctl.rc_gp_srtt;
4579 	/* Record the lost count for the next measurement */
4580 	rack->r_ctl.rc_loss_at_start = rack->r_ctl.rc_loss_count;
4581 	/*
4582 	 * We restart our diffs based on the gpsrtt in the
4583 	 * measurement window.
4584 	 */
4585 	rack->rc_gp_rtt_set = 0;
4586 	rack->rc_gp_saw_rec = 0;
4587 	rack->rc_gp_saw_ca = 0;
4588 	rack->rc_gp_saw_ss = 0;
4589 	rack->rc_dragged_bottom = 0;
4590 skip_measurement:
4591 
4592 #ifdef STATS
4593 	stats_voi_update_abs_u32(tp->t_stats, VOI_TCP_GPUT,
4594 				 gput);
4595 	/*
4596 	 * XXXLAS: This is a temporary hack, and should be
4597 	 * chained off VOI_TCP_GPUT when stats(9) grows an
4598 	 * API to deal with chained VOIs.
4599 	 */
4600 	if (tp->t_stats_gput_prev > 0)
4601 		stats_voi_update_abs_s32(tp->t_stats,
4602 					 VOI_TCP_GPUT_ND,
4603 					 ((gput - tp->t_stats_gput_prev) * 100) /
4604 					 tp->t_stats_gput_prev);
4605 #endif
4606 	tp->t_flags &= ~TF_GPUTINPROG;
4607 	tp->t_stats_gput_prev = gput;
4608 	/*
4609 	 * Now are we app limited now and there is space from where we
4610 	 * were to where we want to go?
4611 	 *
4612 	 * We don't do the other case i.e. non-applimited here since
4613 	 * the next send will trigger us picking up the missing data.
4614 	 */
4615 	if (rack->r_ctl.rc_first_appl &&
4616 	    TCPS_HAVEESTABLISHED(tp->t_state) &&
4617 	    rack->r_ctl.rc_app_limited_cnt &&
4618 	    (SEQ_GT(rack->r_ctl.rc_first_appl->r_start, th_ack)) &&
4619 	    ((rack->r_ctl.rc_first_appl->r_end - th_ack) >
4620 	     max(rc_init_window(rack), (MIN_GP_WIN * segsiz)))) {
4621 		/*
4622 		 * Yep there is enough outstanding to make a measurement here.
4623 		 */
4624 		struct rack_sendmap *rsm, fe;
4625 
4626 		rack->r_ctl.rc_gp_lowrtt = 0xffffffff;
4627 		rack->r_ctl.rc_gp_high_rwnd = rack->rc_tp->snd_wnd;
4628 		tp->gput_ts = tcp_tv_to_usectick(&rack->r_ctl.act_rcv_time);
4629 		rack->app_limited_needs_set = 0;
4630 		tp->gput_seq = th_ack;
4631 		if (rack->in_probe_rtt)
4632 			rack->measure_saw_probe_rtt = 1;
4633 		else if ((rack->measure_saw_probe_rtt) &&
4634 			 (SEQ_GEQ(tp->gput_seq, rack->r_ctl.rc_probertt_sndmax_atexit)))
4635 			rack->measure_saw_probe_rtt = 0;
4636 		if ((rack->r_ctl.rc_first_appl->r_end - th_ack) >= rack_get_measure_window(tp, rack)) {
4637 			/* There is a full window to gain info from */
4638 			tp->gput_ack = tp->gput_seq + rack_get_measure_window(tp, rack);
4639 		} else {
4640 			/* We can only measure up to the applimited point */
4641 			tp->gput_ack = tp->gput_seq + (rack->r_ctl.rc_first_appl->r_end - th_ack);
4642 			if ((tp->gput_ack - tp->gput_seq) < (MIN_GP_WIN * segsiz)) {
4643 				/*
4644 				 * We don't have enough to make a measurement.
4645 				 */
4646 				tp->t_flags &= ~TF_GPUTINPROG;
4647 				rack_log_pacing_delay_calc(rack, tp->gput_ack, tp->gput_seq,
4648 							   0, 0, 0, 6, __LINE__, NULL, quality);
4649 				return;
4650 			}
4651 		}
4652 		if (tp->t_state >= TCPS_FIN_WAIT_1) {
4653 			/*
4654 			 * We will get no more data into the SB
4655 			 * this means we need to have the data available
4656 			 * before we start a measurement.
4657 			 */
4658 			if (sbavail(&tp->t_inpcb->inp_socket->so_snd) < (tp->gput_ack - tp->gput_seq)) {
4659 				/* Nope not enough data. */
4660 				return;
4661 			}
4662 		}
4663 		tp->t_flags |= TF_GPUTINPROG;
4664 		/*
4665 		 * Now we need to find the timestamp of the send at tp->gput_seq
4666 		 * for the send based measurement.
4667 		 */
4668 		fe.r_start = tp->gput_seq;
4669 		rsm = RB_FIND(rack_rb_tree_head, &rack->r_ctl.rc_mtree, &fe);
4670 		if (rsm) {
4671 			/* Ok send-based limit is set */
4672 			if (SEQ_LT(rsm->r_start, tp->gput_seq)) {
4673 				/*
4674 				 * Move back to include the earlier part
4675 				 * so our ack time lines up right (this may
4676 				 * make an overlapping measurement but thats
4677 				 * ok).
4678 				 */
4679 				tp->gput_seq = rsm->r_start;
4680 			}
4681 			if (rsm->r_flags & RACK_ACKED)
4682 				tp->gput_ts = (uint32_t)rsm->r_ack_arrival;
4683 			else
4684 				rack->app_limited_needs_set = 1;
4685 			rack->r_ctl.rc_gp_output_ts = rsm->r_tim_lastsent[(rsm->r_rtr_cnt-1)];
4686 		} else {
4687 			/*
4688 			 * If we don't find the rsm due to some
4689 			 * send-limit set the current time, which
4690 			 * basically disables the send-limit.
4691 			 */
4692 			struct timeval tv;
4693 
4694 			microuptime(&tv);
4695 			rack->r_ctl.rc_gp_output_ts = rack_to_usec_ts(&tv);
4696 		}
4697 		rack_log_pacing_delay_calc(rack,
4698 					   tp->gput_seq,
4699 					   tp->gput_ack,
4700 					   (uint64_t)rsm,
4701 					   tp->gput_ts,
4702 					   rack->r_ctl.rc_app_limited_cnt,
4703 					   9,
4704 					   __LINE__, NULL, quality);
4705 	}
4706 }
4707 
4708 /*
4709  * CC wrapper hook functions
4710  */
4711 static void
4712 rack_ack_received(struct tcpcb *tp, struct tcp_rack *rack, uint32_t th_ack, uint16_t nsegs,
4713     uint16_t type, int32_t recovery)
4714 {
4715 	uint32_t prior_cwnd, acked;
4716 	struct tcp_log_buffer *lgb = NULL;
4717 	uint8_t labc_to_use, quality;
4718 
4719 	INP_WLOCK_ASSERT(tp->t_inpcb);
4720 	tp->ccv->nsegs = nsegs;
4721 	acked = tp->ccv->bytes_this_ack = (th_ack - tp->snd_una);
4722 	if ((recovery) && (rack->r_ctl.rc_early_recovery_segs)) {
4723 		uint32_t max;
4724 
4725 		max = rack->r_ctl.rc_early_recovery_segs * ctf_fixed_maxseg(tp);
4726 		if (tp->ccv->bytes_this_ack > max) {
4727 			tp->ccv->bytes_this_ack = max;
4728 		}
4729 	}
4730 #ifdef STATS
4731 	stats_voi_update_abs_s32(tp->t_stats, VOI_TCP_CALCFRWINDIFF,
4732 	    ((int32_t)rack->r_ctl.cwnd_to_use) - tp->snd_wnd);
4733 #endif
4734 	quality = RACK_QUALITY_NONE;
4735 	if ((tp->t_flags & TF_GPUTINPROG) &&
4736 	    rack_enough_for_measurement(tp, rack, th_ack, &quality)) {
4737 		/* Measure the Goodput */
4738 		rack_do_goodput_measurement(tp, rack, th_ack, __LINE__, quality);
4739 #ifdef NETFLIX_PEAKRATE
4740 		if ((type == CC_ACK) &&
4741 		    (tp->t_maxpeakrate)) {
4742 			/*
4743 			 * We update t_peakrate_thr. This gives us roughly
4744 			 * one update per round trip time. Note
4745 			 * it will only be used if pace_always is off i.e
4746 			 * we don't do this for paced flows.
4747 			 */
4748 			rack_update_peakrate_thr(tp);
4749 		}
4750 #endif
4751 	}
4752 	/* Which way our we limited, if not cwnd limited no advance in CA */
4753 	if (tp->snd_cwnd <= tp->snd_wnd)
4754 		tp->ccv->flags |= CCF_CWND_LIMITED;
4755 	else
4756 		tp->ccv->flags &= ~CCF_CWND_LIMITED;
4757 	if (tp->snd_cwnd > tp->snd_ssthresh) {
4758 		tp->t_bytes_acked += min(tp->ccv->bytes_this_ack,
4759 			 nsegs * V_tcp_abc_l_var * ctf_fixed_maxseg(tp));
4760 		/* For the setting of a window past use the actual scwnd we are using */
4761 		if (tp->t_bytes_acked >= rack->r_ctl.cwnd_to_use) {
4762 			tp->t_bytes_acked -= rack->r_ctl.cwnd_to_use;
4763 			tp->ccv->flags |= CCF_ABC_SENTAWND;
4764 		}
4765 	} else {
4766 		tp->ccv->flags &= ~CCF_ABC_SENTAWND;
4767 		tp->t_bytes_acked = 0;
4768 	}
4769 	prior_cwnd = tp->snd_cwnd;
4770 	if ((recovery == 0) || (rack_max_abc_post_recovery == 0) || rack->r_use_labc_for_rec ||
4771 	    (rack_client_low_buf && (rack->client_bufferlvl < rack_client_low_buf)))
4772 		labc_to_use = rack->rc_labc;
4773 	else
4774 		labc_to_use = rack_max_abc_post_recovery;
4775 	if (rack_verbose_logging && (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF)) {
4776 		union tcp_log_stackspecific log;
4777 		struct timeval tv;
4778 
4779 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
4780 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
4781 		log.u_bbr.flex1 = th_ack;
4782 		log.u_bbr.flex2 = tp->ccv->flags;
4783 		log.u_bbr.flex3 = tp->ccv->bytes_this_ack;
4784 		log.u_bbr.flex4 = tp->ccv->nsegs;
4785 		log.u_bbr.flex5 = labc_to_use;
4786 		log.u_bbr.flex6 = prior_cwnd;
4787 		log.u_bbr.flex7 = V_tcp_do_newsack;
4788 		log.u_bbr.flex8 = 1;
4789 		lgb = tcp_log_event_(tp, NULL, NULL, NULL, BBR_LOG_CWND, 0,
4790 				     0, &log, false, NULL, NULL, 0, &tv);
4791 	}
4792 	if (CC_ALGO(tp)->ack_received != NULL) {
4793 		/* XXXLAS: Find a way to live without this */
4794 		tp->ccv->curack = th_ack;
4795 		tp->ccv->labc = labc_to_use;
4796 		tp->ccv->flags |= CCF_USE_LOCAL_ABC;
4797 		CC_ALGO(tp)->ack_received(tp->ccv, type);
4798 	}
4799 	if (lgb) {
4800 		lgb->tlb_stackinfo.u_bbr.flex6 = tp->snd_cwnd;
4801 	}
4802 	if (rack->r_must_retran) {
4803 		if (SEQ_GEQ(th_ack, rack->r_ctl.rc_snd_max_at_rto)) {
4804 			/*
4805 			 * We now are beyond the rxt point so lets disable
4806 			 * the flag.
4807 			 */
4808 			rack->r_ctl.rc_out_at_rto = 0;
4809 			rack->r_must_retran = 0;
4810 		} else if ((prior_cwnd + ctf_fixed_maxseg(tp)) <= tp->snd_cwnd) {
4811 			/*
4812 			 * Only decrement the rc_out_at_rto if the cwnd advances
4813 			 * at least a whole segment. Otherwise next time the peer
4814 			 * acks, we won't be able to send this generaly happens
4815 			 * when we are in Congestion Avoidance.
4816 			 */
4817 			if (acked <= rack->r_ctl.rc_out_at_rto){
4818 				rack->r_ctl.rc_out_at_rto -= acked;
4819 			} else {
4820 				rack->r_ctl.rc_out_at_rto = 0;
4821 			}
4822 		}
4823 	}
4824 #ifdef STATS
4825 	stats_voi_update_abs_ulong(tp->t_stats, VOI_TCP_LCWIN, rack->r_ctl.cwnd_to_use);
4826 #endif
4827 	if (rack->r_ctl.rc_rack_largest_cwnd < rack->r_ctl.cwnd_to_use) {
4828 		rack->r_ctl.rc_rack_largest_cwnd = rack->r_ctl.cwnd_to_use;
4829 	}
4830 #ifdef NETFLIX_PEAKRATE
4831 	/* we enforce max peak rate if it is set and we are not pacing */
4832 	if ((rack->rc_always_pace == 0) &&
4833 	    tp->t_peakrate_thr &&
4834 	    (tp->snd_cwnd > tp->t_peakrate_thr)) {
4835 		tp->snd_cwnd = tp->t_peakrate_thr;
4836 	}
4837 #endif
4838 }
4839 
4840 static void
4841 tcp_rack_partialack(struct tcpcb *tp)
4842 {
4843 	struct tcp_rack *rack;
4844 
4845 	rack = (struct tcp_rack *)tp->t_fb_ptr;
4846 	INP_WLOCK_ASSERT(tp->t_inpcb);
4847 	/*
4848 	 * If we are doing PRR and have enough
4849 	 * room to send <or> we are pacing and prr
4850 	 * is disabled we will want to see if we
4851 	 * can send data (by setting r_wanted_output to
4852 	 * true).
4853 	 */
4854 	if ((rack->r_ctl.rc_prr_sndcnt > 0) ||
4855 	    rack->rack_no_prr)
4856 		rack->r_wanted_output = 1;
4857 }
4858 
4859 static void
4860 rack_post_recovery(struct tcpcb *tp, uint32_t th_ack)
4861 {
4862 	struct tcp_rack *rack;
4863 	uint32_t orig_cwnd;
4864 
4865 	orig_cwnd = tp->snd_cwnd;
4866 	INP_WLOCK_ASSERT(tp->t_inpcb);
4867 	rack = (struct tcp_rack *)tp->t_fb_ptr;
4868 	/* only alert CC if we alerted when we entered */
4869 	if (CC_ALGO(tp)->post_recovery != NULL) {
4870 		tp->ccv->curack = th_ack;
4871 		CC_ALGO(tp)->post_recovery(tp->ccv);
4872 		if (tp->snd_cwnd < tp->snd_ssthresh) {
4873 			/*
4874 			 * Rack has burst control and pacing
4875 			 * so lets not set this any lower than
4876 			 * snd_ssthresh per RFC-6582 (option 2).
4877 			 */
4878 			tp->snd_cwnd = tp->snd_ssthresh;
4879 		}
4880 	}
4881 	if (rack_verbose_logging && (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF)) {
4882 		union tcp_log_stackspecific log;
4883 		struct timeval tv;
4884 
4885 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
4886 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
4887 		log.u_bbr.flex1 = th_ack;
4888 		log.u_bbr.flex2 = tp->ccv->flags;
4889 		log.u_bbr.flex3 = tp->ccv->bytes_this_ack;
4890 		log.u_bbr.flex4 = tp->ccv->nsegs;
4891 		log.u_bbr.flex5 = V_tcp_abc_l_var;
4892 		log.u_bbr.flex6 = orig_cwnd;
4893 		log.u_bbr.flex7 = V_tcp_do_newsack;
4894 		log.u_bbr.pkts_out = rack->r_ctl.rc_prr_sndcnt;
4895 		log.u_bbr.flex8 = 2;
4896 		tcp_log_event_(tp, NULL, NULL, NULL, BBR_LOG_CWND, 0,
4897 			       0, &log, false, NULL, NULL, 0, &tv);
4898 	}
4899 	if ((rack->rack_no_prr == 0) &&
4900 	    (rack->no_prr_addback == 0) &&
4901 	    (rack->r_ctl.rc_prr_sndcnt > 0)) {
4902 		/*
4903 		 * Suck the next prr cnt back into cwnd, but
4904 		 * only do that if we are not application limited.
4905 		 */
4906 		if (ctf_outstanding(tp) <= sbavail(&(tp->t_inpcb->inp_socket->so_snd))) {
4907 			/*
4908 			 * We are allowed to add back to the cwnd the amount we did
4909 			 * not get out if:
4910 			 * a) no_prr_addback is off.
4911 			 * b) we are not app limited
4912 			 * c) we are doing prr
4913 			 * <and>
4914 			 * d) it is bounded by rack_prr_addbackmax (if addback is 0, then none).
4915 			 */
4916 			tp->snd_cwnd += min((ctf_fixed_maxseg(tp) * rack_prr_addbackmax),
4917 					    rack->r_ctl.rc_prr_sndcnt);
4918 		}
4919 		rack->r_ctl.rc_prr_sndcnt = 0;
4920 		rack_log_to_prr(rack, 1, 0);
4921 	}
4922 	rack_log_to_prr(rack, 14, orig_cwnd);
4923 	tp->snd_recover = tp->snd_una;
4924 	if (rack->r_ctl.dsack_persist) {
4925 		rack->r_ctl.dsack_persist--;
4926 		if (rack->r_ctl.num_dsack && (rack->r_ctl.dsack_persist == 0)) {
4927 			rack->r_ctl.num_dsack = 0;
4928 		}
4929 		rack_log_dsack_event(rack, 1, __LINE__, 0, 0);
4930 	}
4931 	EXIT_RECOVERY(tp->t_flags);
4932 }
4933 
4934 static void
4935 rack_cong_signal(struct tcpcb *tp, uint32_t type, uint32_t ack)
4936 {
4937 	struct tcp_rack *rack;
4938 	uint32_t ssthresh_enter, cwnd_enter, in_rec_at_entry, orig_cwnd;
4939 
4940 	INP_WLOCK_ASSERT(tp->t_inpcb);
4941 #ifdef STATS
4942 	stats_voi_update_abs_u32(tp->t_stats, VOI_TCP_CSIG, type);
4943 #endif
4944 	if (IN_RECOVERY(tp->t_flags) == 0) {
4945 		in_rec_at_entry = 0;
4946 		ssthresh_enter = tp->snd_ssthresh;
4947 		cwnd_enter = tp->snd_cwnd;
4948 	} else
4949 		in_rec_at_entry = 1;
4950 	rack = (struct tcp_rack *)tp->t_fb_ptr;
4951 	switch (type) {
4952 	case CC_NDUPACK:
4953 		tp->t_flags &= ~TF_WASFRECOVERY;
4954 		tp->t_flags &= ~TF_WASCRECOVERY;
4955 		if (!IN_FASTRECOVERY(tp->t_flags)) {
4956 			rack->r_ctl.rc_prr_delivered = 0;
4957 			rack->r_ctl.rc_prr_out = 0;
4958 			if (rack->rack_no_prr == 0) {
4959 				rack->r_ctl.rc_prr_sndcnt = ctf_fixed_maxseg(tp);
4960 				rack_log_to_prr(rack, 2, in_rec_at_entry);
4961 			}
4962 			rack->r_ctl.rc_prr_recovery_fs = tp->snd_max - tp->snd_una;
4963 			tp->snd_recover = tp->snd_max;
4964 			if (tp->t_flags2 & TF2_ECN_PERMIT)
4965 				tp->t_flags2 |= TF2_ECN_SND_CWR;
4966 		}
4967 		break;
4968 	case CC_ECN:
4969 		if (!IN_CONGRECOVERY(tp->t_flags) ||
4970 		    /*
4971 		     * Allow ECN reaction on ACK to CWR, if
4972 		     * that data segment was also CE marked.
4973 		     */
4974 		    SEQ_GEQ(ack, tp->snd_recover)) {
4975 			EXIT_CONGRECOVERY(tp->t_flags);
4976 			KMOD_TCPSTAT_INC(tcps_ecn_rcwnd);
4977 			tp->snd_recover = tp->snd_max + 1;
4978 			if (tp->t_flags2 & TF2_ECN_PERMIT)
4979 				tp->t_flags2 |= TF2_ECN_SND_CWR;
4980 		}
4981 		break;
4982 	case CC_RTO:
4983 		tp->t_dupacks = 0;
4984 		tp->t_bytes_acked = 0;
4985 		EXIT_RECOVERY(tp->t_flags);
4986 		tp->snd_ssthresh = max(2, min(tp->snd_wnd, rack->r_ctl.cwnd_to_use) / 2 /
4987 		    ctf_fixed_maxseg(tp)) * ctf_fixed_maxseg(tp);
4988 		orig_cwnd = tp->snd_cwnd;
4989 		tp->snd_cwnd = ctf_fixed_maxseg(tp);
4990 		rack_log_to_prr(rack, 16, orig_cwnd);
4991 		if (tp->t_flags2 & TF2_ECN_PERMIT)
4992 			tp->t_flags2 |= TF2_ECN_SND_CWR;
4993 		break;
4994 	case CC_RTO_ERR:
4995 		KMOD_TCPSTAT_INC(tcps_sndrexmitbad);
4996 		/* RTO was unnecessary, so reset everything. */
4997 		tp->snd_cwnd = tp->snd_cwnd_prev;
4998 		tp->snd_ssthresh = tp->snd_ssthresh_prev;
4999 		tp->snd_recover = tp->snd_recover_prev;
5000 		if (tp->t_flags & TF_WASFRECOVERY) {
5001 			ENTER_FASTRECOVERY(tp->t_flags);
5002 			tp->t_flags &= ~TF_WASFRECOVERY;
5003 		}
5004 		if (tp->t_flags & TF_WASCRECOVERY) {
5005 			ENTER_CONGRECOVERY(tp->t_flags);
5006 			tp->t_flags &= ~TF_WASCRECOVERY;
5007 		}
5008 		tp->snd_nxt = tp->snd_max;
5009 		tp->t_badrxtwin = 0;
5010 		break;
5011 	}
5012 	if ((CC_ALGO(tp)->cong_signal != NULL)  &&
5013 	    (type != CC_RTO)){
5014 		tp->ccv->curack = ack;
5015 		CC_ALGO(tp)->cong_signal(tp->ccv, type);
5016 	}
5017 	if ((in_rec_at_entry == 0) && IN_RECOVERY(tp->t_flags)) {
5018 		rack_log_to_prr(rack, 15, cwnd_enter);
5019 		rack->r_ctl.dsack_byte_cnt = 0;
5020 		rack->r_ctl.retran_during_recovery = 0;
5021 		rack->r_ctl.rc_cwnd_at_erec = cwnd_enter;
5022 		rack->r_ctl.rc_ssthresh_at_erec = ssthresh_enter;
5023 		rack->r_ent_rec_ns = 1;
5024 	}
5025 }
5026 
5027 static inline void
5028 rack_cc_after_idle(struct tcp_rack *rack, struct tcpcb *tp)
5029 {
5030 	uint32_t i_cwnd;
5031 
5032 	INP_WLOCK_ASSERT(tp->t_inpcb);
5033 
5034 #ifdef NETFLIX_STATS
5035 	KMOD_TCPSTAT_INC(tcps_idle_restarts);
5036 	if (tp->t_state == TCPS_ESTABLISHED)
5037 		KMOD_TCPSTAT_INC(tcps_idle_estrestarts);
5038 #endif
5039 	if (CC_ALGO(tp)->after_idle != NULL)
5040 		CC_ALGO(tp)->after_idle(tp->ccv);
5041 
5042 	if (tp->snd_cwnd == 1)
5043 		i_cwnd = tp->t_maxseg;		/* SYN(-ACK) lost */
5044 	else
5045 		i_cwnd = rc_init_window(rack);
5046 
5047 	/*
5048 	 * Being idle is no differnt than the initial window. If the cc
5049 	 * clamps it down below the initial window raise it to the initial
5050 	 * window.
5051 	 */
5052 	if (tp->snd_cwnd < i_cwnd) {
5053 		tp->snd_cwnd = i_cwnd;
5054 	}
5055 }
5056 
5057 /*
5058  * Indicate whether this ack should be delayed.  We can delay the ack if
5059  * following conditions are met:
5060  *	- There is no delayed ack timer in progress.
5061  *	- Our last ack wasn't a 0-sized window. We never want to delay
5062  *	  the ack that opens up a 0-sized window.
5063  *	- LRO wasn't used for this segment. We make sure by checking that the
5064  *	  segment size is not larger than the MSS.
5065  *	- Delayed acks are enabled or this is a half-synchronized T/TCP
5066  *	  connection.
5067  */
5068 #define DELAY_ACK(tp, tlen)			 \
5069 	(((tp->t_flags & TF_RXWIN0SENT) == 0) && \
5070 	((tp->t_flags & TF_DELACK) == 0) &&	 \
5071 	(tlen <= tp->t_maxseg) &&		 \
5072 	(tp->t_delayed_ack || (tp->t_flags & TF_NEEDSYN)))
5073 
5074 static struct rack_sendmap *
5075 rack_find_lowest_rsm(struct tcp_rack *rack)
5076 {
5077 	struct rack_sendmap *rsm;
5078 
5079 	/*
5080 	 * Walk the time-order transmitted list looking for an rsm that is
5081 	 * not acked. This will be the one that was sent the longest time
5082 	 * ago that is still outstanding.
5083 	 */
5084 	TAILQ_FOREACH(rsm, &rack->r_ctl.rc_tmap, r_tnext) {
5085 		if (rsm->r_flags & RACK_ACKED) {
5086 			continue;
5087 		}
5088 		goto finish;
5089 	}
5090 finish:
5091 	return (rsm);
5092 }
5093 
5094 static struct rack_sendmap *
5095 rack_find_high_nonack(struct tcp_rack *rack, struct rack_sendmap *rsm)
5096 {
5097 	struct rack_sendmap *prsm;
5098 
5099 	/*
5100 	 * Walk the sequence order list backward until we hit and arrive at
5101 	 * the highest seq not acked. In theory when this is called it
5102 	 * should be the last segment (which it was not).
5103 	 */
5104 	counter_u64_add(rack_find_high, 1);
5105 	prsm = rsm;
5106 	RB_FOREACH_REVERSE_FROM(prsm, rack_rb_tree_head, rsm) {
5107 		if (prsm->r_flags & (RACK_ACKED | RACK_HAS_FIN)) {
5108 			continue;
5109 		}
5110 		return (prsm);
5111 	}
5112 	return (NULL);
5113 }
5114 
5115 static uint32_t
5116 rack_calc_thresh_rack(struct tcp_rack *rack, uint32_t srtt, uint32_t cts)
5117 {
5118 	int32_t lro;
5119 	uint32_t thresh;
5120 
5121 	/*
5122 	 * lro is the flag we use to determine if we have seen reordering.
5123 	 * If it gets set we have seen reordering. The reorder logic either
5124 	 * works in one of two ways:
5125 	 *
5126 	 * If reorder-fade is configured, then we track the last time we saw
5127 	 * re-ordering occur. If we reach the point where enough time as
5128 	 * passed we no longer consider reordering has occuring.
5129 	 *
5130 	 * Or if reorder-face is 0, then once we see reordering we consider
5131 	 * the connection to alway be subject to reordering and just set lro
5132 	 * to 1.
5133 	 *
5134 	 * In the end if lro is non-zero we add the extra time for
5135 	 * reordering in.
5136 	 */
5137 	if (srtt == 0)
5138 		srtt = 1;
5139 	if (rack->r_ctl.rc_reorder_ts) {
5140 		if (rack->r_ctl.rc_reorder_fade) {
5141 			if (SEQ_GEQ(cts, rack->r_ctl.rc_reorder_ts)) {
5142 				lro = cts - rack->r_ctl.rc_reorder_ts;
5143 				if (lro == 0) {
5144 					/*
5145 					 * No time as passed since the last
5146 					 * reorder, mark it as reordering.
5147 					 */
5148 					lro = 1;
5149 				}
5150 			} else {
5151 				/* Negative time? */
5152 				lro = 0;
5153 			}
5154 			if (lro > rack->r_ctl.rc_reorder_fade) {
5155 				/* Turn off reordering seen too */
5156 				rack->r_ctl.rc_reorder_ts = 0;
5157 				lro = 0;
5158 			}
5159 		} else {
5160 			/* Reodering does not fade */
5161 			lro = 1;
5162 		}
5163 	} else {
5164 		lro = 0;
5165 	}
5166 	if (rack->rc_rack_tmr_std_based == 0) {
5167 		thresh = srtt + rack->r_ctl.rc_pkt_delay;
5168 	} else {
5169 		/* Standards based pkt-delay is 1/4 srtt */
5170 		thresh = srtt +  (srtt >> 2);
5171 	}
5172 	if (lro && (rack->rc_rack_tmr_std_based == 0)) {
5173 		/* It must be set, if not you get 1/4 rtt */
5174 		if (rack->r_ctl.rc_reorder_shift)
5175 			thresh += (srtt >> rack->r_ctl.rc_reorder_shift);
5176 		else
5177 			thresh += (srtt >> 2);
5178 	}
5179 	if (rack->rc_rack_use_dsack &&
5180 	    lro &&
5181 	    (rack->r_ctl.num_dsack > 0)) {
5182 		/*
5183 		 * We only increase the reordering window if we
5184 		 * have seen reordering <and> we have a DSACK count.
5185 		 */
5186 		thresh += rack->r_ctl.num_dsack * (srtt >> 2);
5187 		rack_log_dsack_event(rack, 4, __LINE__, srtt, thresh);
5188 	}
5189 	/* SRTT * 2 is the ceiling */
5190 	if (thresh > (srtt * 2)) {
5191 		thresh = srtt * 2;
5192 	}
5193 	/* And we don't want it above the RTO max either */
5194 	if (thresh > rack_rto_max) {
5195 		thresh = rack_rto_max;
5196 	}
5197 	rack_log_dsack_event(rack, 6, __LINE__, srtt, thresh);
5198 	return (thresh);
5199 }
5200 
5201 static uint32_t
5202 rack_calc_thresh_tlp(struct tcpcb *tp, struct tcp_rack *rack,
5203 		     struct rack_sendmap *rsm, uint32_t srtt)
5204 {
5205 	struct rack_sendmap *prsm;
5206 	uint32_t thresh, len;
5207 	int segsiz;
5208 
5209 	if (srtt == 0)
5210 		srtt = 1;
5211 	if (rack->r_ctl.rc_tlp_threshold)
5212 		thresh = srtt + (srtt / rack->r_ctl.rc_tlp_threshold);
5213 	else
5214 		thresh = (srtt * 2);
5215 
5216 	/* Get the previous sent packet, if any */
5217 	segsiz = min(ctf_fixed_maxseg(tp), rack->r_ctl.rc_pace_min_segs);
5218 	counter_u64_add(rack_enter_tlp_calc, 1);
5219 	len = rsm->r_end - rsm->r_start;
5220 	if (rack->rack_tlp_threshold_use == TLP_USE_ID) {
5221 		/* Exactly like the ID */
5222 		if (((tp->snd_max - tp->snd_una) - rack->r_ctl.rc_sacked + rack->r_ctl.rc_holes_rxt) <= segsiz) {
5223 			uint32_t alt_thresh;
5224 			/*
5225 			 * Compensate for delayed-ack with the d-ack time.
5226 			 */
5227 			counter_u64_add(rack_used_tlpmethod, 1);
5228 			alt_thresh = srtt + (srtt / 2) + rack_delayed_ack_time;
5229 			if (alt_thresh > thresh)
5230 				thresh = alt_thresh;
5231 		}
5232 	} else if (rack->rack_tlp_threshold_use == TLP_USE_TWO_ONE) {
5233 		/* 2.1 behavior */
5234 		prsm = TAILQ_PREV(rsm, rack_head, r_tnext);
5235 		if (prsm && (len <= segsiz)) {
5236 			/*
5237 			 * Two packets outstanding, thresh should be (2*srtt) +
5238 			 * possible inter-packet delay (if any).
5239 			 */
5240 			uint32_t inter_gap = 0;
5241 			int idx, nidx;
5242 
5243 			counter_u64_add(rack_used_tlpmethod, 1);
5244 			idx = rsm->r_rtr_cnt - 1;
5245 			nidx = prsm->r_rtr_cnt - 1;
5246 			if (rsm->r_tim_lastsent[nidx] >= prsm->r_tim_lastsent[idx]) {
5247 				/* Yes it was sent later (or at the same time) */
5248 				inter_gap = rsm->r_tim_lastsent[idx] - prsm->r_tim_lastsent[nidx];
5249 			}
5250 			thresh += inter_gap;
5251 		} else if (len <= segsiz) {
5252 			/*
5253 			 * Possibly compensate for delayed-ack.
5254 			 */
5255 			uint32_t alt_thresh;
5256 
5257 			counter_u64_add(rack_used_tlpmethod2, 1);
5258 			alt_thresh = srtt + (srtt / 2) + rack_delayed_ack_time;
5259 			if (alt_thresh > thresh)
5260 				thresh = alt_thresh;
5261 		}
5262 	} else if (rack->rack_tlp_threshold_use == TLP_USE_TWO_TWO) {
5263 		/* 2.2 behavior */
5264 		if (len <= segsiz) {
5265 			uint32_t alt_thresh;
5266 			/*
5267 			 * Compensate for delayed-ack with the d-ack time.
5268 			 */
5269 			counter_u64_add(rack_used_tlpmethod, 1);
5270 			alt_thresh = srtt + (srtt / 2) + rack_delayed_ack_time;
5271 			if (alt_thresh > thresh)
5272 				thresh = alt_thresh;
5273 		}
5274 	}
5275 	/* Not above an RTO */
5276 	if (thresh > tp->t_rxtcur) {
5277 		thresh = tp->t_rxtcur;
5278 	}
5279 	/* Not above a RTO max */
5280 	if (thresh > rack_rto_max) {
5281 		thresh = rack_rto_max;
5282 	}
5283 	/* Apply user supplied min TLP */
5284 	if (thresh < rack_tlp_min) {
5285 		thresh = rack_tlp_min;
5286 	}
5287 	return (thresh);
5288 }
5289 
5290 static uint32_t
5291 rack_grab_rtt(struct tcpcb *tp, struct tcp_rack *rack)
5292 {
5293 	/*
5294 	 * We want the rack_rtt which is the
5295 	 * last rtt we measured. However if that
5296 	 * does not exist we fallback to the srtt (which
5297 	 * we probably will never do) and then as a last
5298 	 * resort we use RACK_INITIAL_RTO if no srtt is
5299 	 * yet set.
5300 	 */
5301 	if (rack->rc_rack_rtt)
5302 		return (rack->rc_rack_rtt);
5303 	else if (tp->t_srtt == 0)
5304 		return (RACK_INITIAL_RTO);
5305 	return (tp->t_srtt);
5306 }
5307 
5308 static struct rack_sendmap *
5309 rack_check_recovery_mode(struct tcpcb *tp, uint32_t tsused)
5310 {
5311 	/*
5312 	 * Check to see that we don't need to fall into recovery. We will
5313 	 * need to do so if our oldest transmit is past the time we should
5314 	 * have had an ack.
5315 	 */
5316 	struct tcp_rack *rack;
5317 	struct rack_sendmap *rsm;
5318 	int32_t idx;
5319 	uint32_t srtt, thresh;
5320 
5321 	rack = (struct tcp_rack *)tp->t_fb_ptr;
5322 	if (RB_EMPTY(&rack->r_ctl.rc_mtree)) {
5323 		return (NULL);
5324 	}
5325 	rsm = TAILQ_FIRST(&rack->r_ctl.rc_tmap);
5326 	if (rsm == NULL)
5327 		return (NULL);
5328 
5329 	if (rsm->r_flags & RACK_ACKED) {
5330 		rsm = rack_find_lowest_rsm(rack);
5331 		if (rsm == NULL)
5332 			return (NULL);
5333 	}
5334 	idx = rsm->r_rtr_cnt - 1;
5335 	srtt = rack_grab_rtt(tp, rack);
5336 	thresh = rack_calc_thresh_rack(rack, srtt, tsused);
5337 	if (TSTMP_LT(tsused, ((uint32_t)rsm->r_tim_lastsent[idx]))) {
5338 		return (NULL);
5339 	}
5340 	if ((tsused - ((uint32_t)rsm->r_tim_lastsent[idx])) < thresh) {
5341 		return (NULL);
5342 	}
5343 	/* Ok if we reach here we are over-due and this guy can be sent */
5344 	if (IN_RECOVERY(tp->t_flags) == 0) {
5345 		/*
5346 		 * For the one that enters us into recovery record undo
5347 		 * info.
5348 		 */
5349 		rack->r_ctl.rc_rsm_start = rsm->r_start;
5350 		rack->r_ctl.rc_cwnd_at = tp->snd_cwnd;
5351 		rack->r_ctl.rc_ssthresh_at = tp->snd_ssthresh;
5352 	}
5353 	rack_cong_signal(tp, CC_NDUPACK, tp->snd_una);
5354 	return (rsm);
5355 }
5356 
5357 static uint32_t
5358 rack_get_persists_timer_val(struct tcpcb *tp, struct tcp_rack *rack)
5359 {
5360 	int32_t t;
5361 	int32_t tt;
5362 	uint32_t ret_val;
5363 
5364 	t = (tp->t_srtt + (tp->t_rttvar << 2));
5365 	RACK_TCPT_RANGESET(tt, t * tcp_backoff[tp->t_rxtshift],
5366  	    rack_persist_min, rack_persist_max, rack->r_ctl.timer_slop);
5367 	rack->r_ctl.rc_hpts_flags |= PACE_TMR_PERSIT;
5368 	ret_val = (uint32_t)tt;
5369 	return (ret_val);
5370 }
5371 
5372 static uint32_t
5373 rack_timer_start(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cts, int sup_rack)
5374 {
5375 	/*
5376 	 * Start the FR timer, we do this based on getting the first one in
5377 	 * the rc_tmap. Note that if its NULL we must stop the timer. in all
5378 	 * events we need to stop the running timer (if its running) before
5379 	 * starting the new one.
5380 	 */
5381 	uint32_t thresh, exp, to, srtt, time_since_sent, tstmp_touse;
5382 	uint32_t srtt_cur;
5383 	int32_t idx;
5384 	int32_t is_tlp_timer = 0;
5385 	struct rack_sendmap *rsm;
5386 
5387 	if (rack->t_timers_stopped) {
5388 		/* All timers have been stopped none are to run */
5389 		return (0);
5390 	}
5391 	if (rack->rc_in_persist) {
5392 		/* We can't start any timer in persists */
5393 		return (rack_get_persists_timer_val(tp, rack));
5394 	}
5395 	rack->rc_on_min_to = 0;
5396 	if ((tp->t_state < TCPS_ESTABLISHED) ||
5397 	    ((tp->t_flags & TF_SACK_PERMIT) == 0)) {
5398 		goto activate_rxt;
5399 	}
5400 	rsm = TAILQ_FIRST(&rack->r_ctl.rc_tmap);
5401 	if ((rsm == NULL) || sup_rack) {
5402 		/* Nothing on the send map or no rack */
5403 activate_rxt:
5404 		time_since_sent = 0;
5405 		rsm = TAILQ_FIRST(&rack->r_ctl.rc_tmap);
5406 		if (rsm) {
5407 			/*
5408 			 * Should we discount the RTX timer any?
5409 			 *
5410 			 * We want to discount it the smallest amount.
5411 			 * If a timer (Rack/TLP or RXT) has gone off more
5412 			 * recently thats the discount we want to use (now - timer time).
5413 			 * If the retransmit of the oldest packet was more recent then
5414 			 * we want to use that (now - oldest-packet-last_transmit_time).
5415 			 *
5416 			 */
5417 			idx = rsm->r_rtr_cnt - 1;
5418 			if (TSTMP_GEQ(rack->r_ctl.rc_tlp_rxt_last_time, ((uint32_t)rsm->r_tim_lastsent[idx])))
5419 				tstmp_touse = (uint32_t)rack->r_ctl.rc_tlp_rxt_last_time;
5420 			else
5421 				tstmp_touse = (uint32_t)rsm->r_tim_lastsent[idx];
5422 			if (TSTMP_GT(cts, tstmp_touse))
5423 			    time_since_sent = cts - tstmp_touse;
5424 		}
5425 		if (SEQ_LT(tp->snd_una, tp->snd_max) || sbavail(&(tp->t_inpcb->inp_socket->so_snd))) {
5426 			rack->r_ctl.rc_hpts_flags |= PACE_TMR_RXT;
5427 			to = tp->t_rxtcur;
5428 			if (to > time_since_sent)
5429 				to -= time_since_sent;
5430 			else
5431 				to = rack->r_ctl.rc_min_to;
5432 			if (to == 0)
5433 				to = 1;
5434 			/* Special case for KEEPINIT */
5435 			if ((TCPS_HAVEESTABLISHED(tp->t_state) == 0) &&
5436 			    (TP_KEEPINIT(tp) != 0) &&
5437 			    rsm) {
5438 				/*
5439 				 * We have to put a ceiling on the rxt timer
5440 				 * of the keep-init timeout.
5441 				 */
5442 				uint32_t max_time, red;
5443 
5444 				max_time = TICKS_2_USEC(TP_KEEPINIT(tp));
5445 				if (TSTMP_GT(cts, (uint32_t)rsm->r_tim_lastsent[0])) {
5446 					red = (cts - (uint32_t)rsm->r_tim_lastsent[0]);
5447 					if (red < max_time)
5448 						max_time -= red;
5449 					else
5450 						max_time = 1;
5451 				}
5452 				/* Reduce timeout to the keep value if needed */
5453 				if (max_time < to)
5454 					to = max_time;
5455 			}
5456 			return (to);
5457 		}
5458 		return (0);
5459 	}
5460 	if (rsm->r_flags & RACK_ACKED) {
5461 		rsm = rack_find_lowest_rsm(rack);
5462 		if (rsm == NULL) {
5463 			/* No lowest? */
5464 			goto activate_rxt;
5465 		}
5466 	}
5467 	if (rack->sack_attack_disable) {
5468 		/*
5469 		 * We don't want to do
5470 		 * any TLP's if you are an attacker.
5471 		 * Though if you are doing what
5472 		 * is expected you may still have
5473 		 * SACK-PASSED marks.
5474 		 */
5475 		goto activate_rxt;
5476 	}
5477 	/* Convert from ms to usecs */
5478 	if ((rsm->r_flags & RACK_SACK_PASSED) || (rsm->r_dupack >= DUP_ACK_THRESHOLD)) {
5479 		if ((tp->t_flags & TF_SENTFIN) &&
5480 		    ((tp->snd_max - tp->snd_una) == 1) &&
5481 		    (rsm->r_flags & RACK_HAS_FIN)) {
5482 			/*
5483 			 * We don't start a rack timer if all we have is a
5484 			 * FIN outstanding.
5485 			 */
5486 			goto activate_rxt;
5487 		}
5488 		if ((rack->use_rack_rr == 0) &&
5489 		    (IN_FASTRECOVERY(tp->t_flags)) &&
5490 		    (rack->rack_no_prr == 0) &&
5491 		     (rack->r_ctl.rc_prr_sndcnt  < ctf_fixed_maxseg(tp))) {
5492 			/*
5493 			 * We are not cheating, in recovery  and
5494 			 * not enough ack's to yet get our next
5495 			 * retransmission out.
5496 			 *
5497 			 * Note that classified attackers do not
5498 			 * get to use the rack-cheat.
5499 			 */
5500 			goto activate_tlp;
5501 		}
5502 		srtt = rack_grab_rtt(tp, rack);
5503 		thresh = rack_calc_thresh_rack(rack, srtt, cts);
5504 		idx = rsm->r_rtr_cnt - 1;
5505 		exp = ((uint32_t)rsm->r_tim_lastsent[idx]) + thresh;
5506 		if (SEQ_GEQ(exp, cts)) {
5507 			to = exp - cts;
5508 			if (to < rack->r_ctl.rc_min_to) {
5509 				to = rack->r_ctl.rc_min_to;
5510 				if (rack->r_rr_config == 3)
5511 					rack->rc_on_min_to = 1;
5512 			}
5513 		} else {
5514 			to = rack->r_ctl.rc_min_to;
5515 			if (rack->r_rr_config == 3)
5516 				rack->rc_on_min_to = 1;
5517 		}
5518 	} else {
5519 		/* Ok we need to do a TLP not RACK */
5520 activate_tlp:
5521 		if ((rack->rc_tlp_in_progress != 0) &&
5522 		    (rack->r_ctl.rc_tlp_cnt_out >= rack_tlp_limit)) {
5523 			/*
5524 			 * The previous send was a TLP and we have sent
5525 			 * N TLP's without sending new data.
5526 			 */
5527 			goto activate_rxt;
5528 		}
5529 		rsm = TAILQ_LAST_FAST(&rack->r_ctl.rc_tmap, rack_sendmap, r_tnext);
5530 		if (rsm == NULL) {
5531 			/* We found no rsm to TLP with. */
5532 			goto activate_rxt;
5533 		}
5534 		if (rsm->r_flags & RACK_HAS_FIN) {
5535 			/* If its a FIN we dont do TLP */
5536 			rsm = NULL;
5537 			goto activate_rxt;
5538 		}
5539 		idx = rsm->r_rtr_cnt - 1;
5540 		time_since_sent = 0;
5541 		if (TSTMP_GEQ(((uint32_t)rsm->r_tim_lastsent[idx]), rack->r_ctl.rc_tlp_rxt_last_time))
5542 			tstmp_touse = (uint32_t)rsm->r_tim_lastsent[idx];
5543 		else
5544 			tstmp_touse = (uint32_t)rack->r_ctl.rc_tlp_rxt_last_time;
5545 		if (TSTMP_GT(cts, tstmp_touse))
5546 		    time_since_sent = cts - tstmp_touse;
5547 		is_tlp_timer = 1;
5548 		if (tp->t_srtt) {
5549 			if ((rack->rc_srtt_measure_made == 0) &&
5550 			    (tp->t_srtt == 1)) {
5551 				/*
5552 				 * If another stack as run and set srtt to 1,
5553 				 * then the srtt was 0, so lets use the initial.
5554 				 */
5555 				srtt = RACK_INITIAL_RTO;
5556 			} else {
5557 				srtt_cur = tp->t_srtt;
5558 				srtt = srtt_cur;
5559 			}
5560 		} else
5561 			srtt = RACK_INITIAL_RTO;
5562 		/*
5563 		 * If the SRTT is not keeping up and the
5564 		 * rack RTT has spiked we want to use
5565 		 * the last RTT not the smoothed one.
5566 		 */
5567 		if (rack_tlp_use_greater &&
5568 		    tp->t_srtt &&
5569 		    (srtt < rack_grab_rtt(tp, rack))) {
5570 			srtt = rack_grab_rtt(tp, rack);
5571 		}
5572 		thresh = rack_calc_thresh_tlp(tp, rack, rsm, srtt);
5573 		if (thresh > time_since_sent) {
5574 			to = thresh - time_since_sent;
5575 		} else {
5576 			to = rack->r_ctl.rc_min_to;
5577 			rack_log_alt_to_to_cancel(rack,
5578 						  thresh,		/* flex1 */
5579 						  time_since_sent,	/* flex2 */
5580 						  tstmp_touse,		/* flex3 */
5581 						  rack->r_ctl.rc_tlp_rxt_last_time, /* flex4 */
5582 						  (uint32_t)rsm->r_tim_lastsent[idx],
5583 						  srtt,
5584 						  idx, 99);
5585 		}
5586 		if (to < rack_tlp_min) {
5587 			to = rack_tlp_min;
5588 		}
5589 		if (to > TICKS_2_USEC(TCPTV_REXMTMAX)) {
5590 			/*
5591 			 * If the TLP time works out to larger than the max
5592 			 * RTO lets not do TLP.. just RTO.
5593 			 */
5594 			goto activate_rxt;
5595 		}
5596 	}
5597 	if (is_tlp_timer == 0) {
5598 		rack->r_ctl.rc_hpts_flags |= PACE_TMR_RACK;
5599 	} else {
5600 		rack->r_ctl.rc_hpts_flags |= PACE_TMR_TLP;
5601 	}
5602 	if (to == 0)
5603 		to = 1;
5604 	return (to);
5605 }
5606 
5607 static void
5608 rack_enter_persist(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cts)
5609 {
5610 	if (rack->rc_in_persist == 0) {
5611 		if (tp->t_flags & TF_GPUTINPROG) {
5612 			/*
5613 			 * Stop the goodput now, the calling of the
5614 			 * measurement function clears the flag.
5615 			 */
5616 			rack_do_goodput_measurement(tp, rack, tp->snd_una, __LINE__,
5617 						    RACK_QUALITY_PERSIST);
5618 		}
5619 #ifdef NETFLIX_SHARED_CWND
5620 		if (rack->r_ctl.rc_scw) {
5621 			tcp_shared_cwnd_idle(rack->r_ctl.rc_scw, rack->r_ctl.rc_scw_index);
5622 			rack->rack_scwnd_is_idle = 1;
5623 		}
5624 #endif
5625 		rack->r_ctl.rc_went_idle_time = tcp_get_usecs(NULL);
5626 		if (rack->r_ctl.rc_went_idle_time == 0)
5627 			rack->r_ctl.rc_went_idle_time = 1;
5628 		rack_timer_cancel(tp, rack, cts, __LINE__);
5629 		tp->t_rxtshift = 0;
5630 		RACK_TCPT_RANGESET(tp->t_rxtcur, RACK_REXMTVAL(tp),
5631 			      rack_rto_min, rack_rto_max, rack->r_ctl.timer_slop);
5632 		rack->rc_in_persist = 1;
5633 	}
5634 }
5635 
5636 static void
5637 rack_exit_persist(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cts)
5638 {
5639 	if (rack->rc_inp->inp_in_hpts) {
5640 		tcp_hpts_remove(rack->rc_inp, HPTS_REMOVE_OUTPUT);
5641 		rack->r_ctl.rc_hpts_flags = 0;
5642 	}
5643 #ifdef NETFLIX_SHARED_CWND
5644 	if (rack->r_ctl.rc_scw) {
5645 		tcp_shared_cwnd_active(rack->r_ctl.rc_scw, rack->r_ctl.rc_scw_index);
5646 		rack->rack_scwnd_is_idle = 0;
5647 	}
5648 #endif
5649 	if (rack->rc_gp_dyn_mul &&
5650 	    (rack->use_fixed_rate == 0) &&
5651 	    (rack->rc_always_pace)) {
5652 		/*
5653 		 * Do we count this as if a probe-rtt just
5654 		 * finished?
5655 		 */
5656 		uint32_t time_idle, idle_min;
5657 
5658 		time_idle = tcp_get_usecs(NULL) - rack->r_ctl.rc_went_idle_time;
5659 		idle_min = rack_min_probertt_hold;
5660 		if (rack_probertt_gpsrtt_cnt_div) {
5661 			uint64_t extra;
5662 			extra = (uint64_t)rack->r_ctl.rc_gp_srtt *
5663 				(uint64_t)rack_probertt_gpsrtt_cnt_mul;
5664 			extra /= (uint64_t)rack_probertt_gpsrtt_cnt_div;
5665 			idle_min += (uint32_t)extra;
5666 		}
5667 		if (time_idle >= idle_min) {
5668 			/* Yes, we count it as a probe-rtt. */
5669 			uint32_t us_cts;
5670 
5671 			us_cts = tcp_get_usecs(NULL);
5672 			if (rack->in_probe_rtt == 0) {
5673 				rack->r_ctl.rc_lower_rtt_us_cts = us_cts;
5674 				rack->r_ctl.rc_time_probertt_entered = rack->r_ctl.rc_lower_rtt_us_cts;
5675 				rack->r_ctl.rc_time_probertt_starts = rack->r_ctl.rc_lower_rtt_us_cts;
5676 				rack->r_ctl.rc_time_of_last_probertt = rack->r_ctl.rc_lower_rtt_us_cts;
5677 			} else {
5678 				rack_exit_probertt(rack, us_cts);
5679 			}
5680 		}
5681 	}
5682 	rack->rc_in_persist = 0;
5683 	rack->r_ctl.rc_went_idle_time = 0;
5684 	tp->t_rxtshift = 0;
5685 	RACK_TCPT_RANGESET(tp->t_rxtcur, RACK_REXMTVAL(tp),
5686 	   rack_rto_min, rack_rto_max, rack->r_ctl.timer_slop);
5687 	rack->r_ctl.rc_agg_delayed = 0;
5688 	rack->r_early = 0;
5689 	rack->r_late = 0;
5690 	rack->r_ctl.rc_agg_early = 0;
5691 }
5692 
5693 static void
5694 rack_log_hpts_diag(struct tcp_rack *rack, uint32_t cts,
5695 		   struct hpts_diag *diag, struct timeval *tv)
5696 {
5697 	if (rack_verbose_logging && rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
5698 		union tcp_log_stackspecific log;
5699 
5700 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
5701 		log.u_bbr.flex1 = diag->p_nxt_slot;
5702 		log.u_bbr.flex2 = diag->p_cur_slot;
5703 		log.u_bbr.flex3 = diag->slot_req;
5704 		log.u_bbr.flex4 = diag->inp_hptsslot;
5705 		log.u_bbr.flex5 = diag->slot_remaining;
5706 		log.u_bbr.flex6 = diag->need_new_to;
5707 		log.u_bbr.flex7 = diag->p_hpts_active;
5708 		log.u_bbr.flex8 = diag->p_on_min_sleep;
5709 		/* Hijack other fields as needed */
5710 		log.u_bbr.epoch = diag->have_slept;
5711 		log.u_bbr.lt_epoch = diag->yet_to_sleep;
5712 		log.u_bbr.pkts_out = diag->co_ret;
5713 		log.u_bbr.applimited = diag->hpts_sleep_time;
5714 		log.u_bbr.delivered = diag->p_prev_slot;
5715 		log.u_bbr.inflight = diag->p_runningslot;
5716 		log.u_bbr.bw_inuse = diag->wheel_slot;
5717 		log.u_bbr.rttProp = diag->wheel_cts;
5718 		log.u_bbr.timeStamp = cts;
5719 		log.u_bbr.delRate = diag->maxslots;
5720 		log.u_bbr.cur_del_rate = diag->p_curtick;
5721 		log.u_bbr.cur_del_rate <<= 32;
5722 		log.u_bbr.cur_del_rate |= diag->p_lasttick;
5723 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
5724 		    &rack->rc_inp->inp_socket->so_rcv,
5725 		    &rack->rc_inp->inp_socket->so_snd,
5726 		    BBR_LOG_HPTSDIAG, 0,
5727 		    0, &log, false, tv);
5728 	}
5729 
5730 }
5731 
5732 static void
5733 rack_log_wakeup(struct tcpcb *tp, struct tcp_rack *rack, struct sockbuf *sb, uint32_t len, int type)
5734 {
5735 	if (rack_verbose_logging && rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
5736 		union tcp_log_stackspecific log;
5737 		struct timeval tv;
5738 
5739 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
5740 		log.u_bbr.flex1 = sb->sb_flags;
5741 		log.u_bbr.flex2 = len;
5742 		log.u_bbr.flex3 = sb->sb_state;
5743 		log.u_bbr.flex8 = type;
5744 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
5745 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
5746 		    &rack->rc_inp->inp_socket->so_rcv,
5747 		    &rack->rc_inp->inp_socket->so_snd,
5748 		    TCP_LOG_SB_WAKE, 0,
5749 		    len, &log, false, &tv);
5750 	}
5751 }
5752 
5753 static void
5754 rack_start_hpts_timer(struct tcp_rack *rack, struct tcpcb *tp, uint32_t cts,
5755       int32_t slot, uint32_t tot_len_this_send, int sup_rack)
5756 {
5757 	struct hpts_diag diag;
5758 	struct inpcb *inp;
5759 	struct timeval tv;
5760 	uint32_t delayed_ack = 0;
5761 	uint32_t hpts_timeout;
5762 	uint32_t entry_slot = slot;
5763 	uint8_t stopped;
5764 	uint32_t left = 0;
5765 	uint32_t us_cts;
5766 
5767 	inp = tp->t_inpcb;
5768 	if ((tp->t_state == TCPS_CLOSED) ||
5769 	    (tp->t_state == TCPS_LISTEN)) {
5770 		return;
5771 	}
5772 	if (inp->inp_in_hpts) {
5773 		/* Already on the pacer */
5774 		return;
5775 	}
5776 	stopped = rack->rc_tmr_stopped;
5777 	if (stopped && TSTMP_GT(rack->r_ctl.rc_timer_exp, cts)) {
5778 		left = rack->r_ctl.rc_timer_exp - cts;
5779 	}
5780 	rack->r_ctl.rc_timer_exp = 0;
5781 	rack->r_ctl.rc_hpts_flags = 0;
5782 	us_cts = tcp_get_usecs(&tv);
5783 	/* Now early/late accounting */
5784 	rack_log_pacing_delay_calc(rack, entry_slot, slot, 0, 0, 0, 26, __LINE__, NULL, 0);
5785 	if (rack->r_early && (rack->rc_ack_can_sendout_data == 0)) {
5786 		/*
5787 		 * We have a early carry over set,
5788 		 * we can always add more time so we
5789 		 * can always make this compensation.
5790 		 *
5791 		 * Note if ack's are allowed to wake us do not
5792 		 * penalize the next timer for being awoke
5793 		 * by an ack aka the rc_agg_early (non-paced mode).
5794 		 */
5795 		slot += rack->r_ctl.rc_agg_early;
5796 		rack->r_early = 0;
5797 		rack->r_ctl.rc_agg_early = 0;
5798 	}
5799 	if (rack->r_late) {
5800 		/*
5801 		 * This is harder, we can
5802 		 * compensate some but it
5803 		 * really depends on what
5804 		 * the current pacing time is.
5805 		 */
5806 		if (rack->r_ctl.rc_agg_delayed >= slot) {
5807 			/*
5808 			 * We can't compensate for it all.
5809 			 * And we have to have some time
5810 			 * on the clock. We always have a min
5811 			 * 10 slots (10 x 10 i.e. 100 usecs).
5812 			 */
5813 			if (slot <= HPTS_TICKS_PER_SLOT) {
5814 				/* We gain delay */
5815 				rack->r_ctl.rc_agg_delayed += (HPTS_TICKS_PER_SLOT - slot);
5816 				slot = HPTS_TICKS_PER_SLOT;
5817 			} else {
5818 				/* We take off some */
5819 				rack->r_ctl.rc_agg_delayed -= (slot - HPTS_TICKS_PER_SLOT);
5820 				slot = HPTS_TICKS_PER_SLOT;
5821 			}
5822 		} else {
5823 			slot -= rack->r_ctl.rc_agg_delayed;
5824 			rack->r_ctl.rc_agg_delayed = 0;
5825 			/* Make sure we have 100 useconds at minimum */
5826 			if (slot < HPTS_TICKS_PER_SLOT) {
5827 				rack->r_ctl.rc_agg_delayed = HPTS_TICKS_PER_SLOT - slot;
5828 				slot = HPTS_TICKS_PER_SLOT;
5829 			}
5830 			if (rack->r_ctl.rc_agg_delayed == 0)
5831 				rack->r_late = 0;
5832 		}
5833 	}
5834 	if (slot) {
5835 		/* We are pacing too */
5836 		rack->r_ctl.rc_hpts_flags |= PACE_PKT_OUTPUT;
5837 	}
5838 	hpts_timeout = rack_timer_start(tp, rack, cts, sup_rack);
5839 #ifdef NETFLIX_EXP_DETECTION
5840 	if (rack->sack_attack_disable &&
5841 	    (slot < tcp_sad_pacing_interval)) {
5842 		/*
5843 		 * We have a potential attacker on
5844 		 * the line. We have possibly some
5845 		 * (or now) pacing time set. We want to
5846 		 * slow down the processing of sacks by some
5847 		 * amount (if it is an attacker). Set the default
5848 		 * slot for attackers in place (unless the orginal
5849 		 * interval is longer). Its stored in
5850 		 * micro-seconds, so lets convert to msecs.
5851 		 */
5852 		slot = tcp_sad_pacing_interval;
5853 	}
5854 #endif
5855 	if (tp->t_flags & TF_DELACK) {
5856 		delayed_ack = TICKS_2_USEC(tcp_delacktime);
5857 		rack->r_ctl.rc_hpts_flags |= PACE_TMR_DELACK;
5858 	}
5859 	if (delayed_ack && ((hpts_timeout == 0) ||
5860 			    (delayed_ack < hpts_timeout)))
5861 		hpts_timeout = delayed_ack;
5862 	else
5863 		rack->r_ctl.rc_hpts_flags &= ~PACE_TMR_DELACK;
5864 	/*
5865 	 * If no timers are going to run and we will fall off the hptsi
5866 	 * wheel, we resort to a keep-alive timer if its configured.
5867 	 */
5868 	if ((hpts_timeout == 0) &&
5869 	    (slot == 0)) {
5870 		if ((V_tcp_always_keepalive || inp->inp_socket->so_options & SO_KEEPALIVE) &&
5871 		    (tp->t_state <= TCPS_CLOSING)) {
5872 			/*
5873 			 * Ok we have no timer (persists, rack, tlp, rxt  or
5874 			 * del-ack), we don't have segments being paced. So
5875 			 * all that is left is the keepalive timer.
5876 			 */
5877 			if (TCPS_HAVEESTABLISHED(tp->t_state)) {
5878 				/* Get the established keep-alive time */
5879 				hpts_timeout = TICKS_2_USEC(TP_KEEPIDLE(tp));
5880 			} else {
5881 				/*
5882 				 * Get the initial setup keep-alive time,
5883 				 * note that this is probably not going to
5884 				 * happen, since rack will be running a rxt timer
5885 				 * if a SYN of some sort is outstanding. It is
5886 				 * actually handled in rack_timeout_rxt().
5887 				 */
5888 				hpts_timeout = TICKS_2_USEC(TP_KEEPINIT(tp));
5889 			}
5890 			rack->r_ctl.rc_hpts_flags |= PACE_TMR_KEEP;
5891 			if (rack->in_probe_rtt) {
5892 				/*
5893 				 * We want to instead not wake up a long time from
5894 				 * now but to wake up about the time we would
5895 				 * exit probe-rtt and initiate a keep-alive ack.
5896 				 * This will get us out of probe-rtt and update
5897 				 * our min-rtt.
5898 				 */
5899 				hpts_timeout = rack_min_probertt_hold;
5900 			}
5901 		}
5902 	}
5903 	if (left && (stopped & (PACE_TMR_KEEP | PACE_TMR_DELACK)) ==
5904 	    (rack->r_ctl.rc_hpts_flags & PACE_TMR_MASK)) {
5905 		/*
5906 		 * RACK, TLP, persists and RXT timers all are restartable
5907 		 * based on actions input .. i.e we received a packet (ack
5908 		 * or sack) and that changes things (rw, or snd_una etc).
5909 		 * Thus we can restart them with a new value. For
5910 		 * keep-alive, delayed_ack we keep track of what was left
5911 		 * and restart the timer with a smaller value.
5912 		 */
5913 		if (left < hpts_timeout)
5914 			hpts_timeout = left;
5915 	}
5916 	if (hpts_timeout) {
5917 		/*
5918 		 * Hack alert for now we can't time-out over 2,147,483
5919 		 * seconds (a bit more than 596 hours), which is probably ok
5920 		 * :).
5921 		 */
5922 		if (hpts_timeout > 0x7ffffffe)
5923 			hpts_timeout = 0x7ffffffe;
5924 		rack->r_ctl.rc_timer_exp = cts + hpts_timeout;
5925 	}
5926 	rack_log_pacing_delay_calc(rack, entry_slot, slot, hpts_timeout, 0, 0, 27, __LINE__, NULL, 0);
5927 	if ((rack->gp_ready == 0) &&
5928 	    (rack->use_fixed_rate == 0) &&
5929 	    (hpts_timeout < slot) &&
5930 	    (rack->r_ctl.rc_hpts_flags & (PACE_TMR_TLP|PACE_TMR_RXT))) {
5931 		/*
5932 		 * We have no good estimate yet for the
5933 		 * old clunky burst mitigation or the
5934 		 * real pacing. And the tlp or rxt is smaller
5935 		 * than the pacing calculation. Lets not
5936 		 * pace that long since we know the calculation
5937 		 * so far is not accurate.
5938 		 */
5939 		slot = hpts_timeout;
5940 	}
5941 	rack->r_ctl.last_pacing_time = slot;
5942 	/**
5943 	 * Turn off all the flags for queuing by default. The
5944 	 * flags have important meanings to what happens when
5945 	 * LRO interacts with the transport. Most likely (by default now)
5946 	 * mbuf_queueing and ack compression are on. So the transport
5947 	 * has a couple of flags that control what happens (if those
5948 	 * are not on then these flags won't have any effect since it
5949 	 * won't go through the queuing LRO path).
5950 	 *
5951 	 * INP_MBUF_QUEUE_READY - This flags says that I am busy
5952 	 *                        pacing output, so don't disturb. But
5953 	 *                        it also means LRO can wake me if there
5954 	 *                        is a SACK arrival.
5955 	 *
5956 	 * INP_DONT_SACK_QUEUE - This flag is used in conjunction
5957 	 *                       with the above flag (QUEUE_READY) and
5958 	 *                       when present it says don't even wake me
5959 	 *                       if a SACK arrives.
5960 	 *
5961 	 * The idea behind these flags is that if we are pacing we
5962 	 * set the MBUF_QUEUE_READY and only get woken up if
5963 	 * a SACK arrives (which could change things) or if
5964 	 * our pacing timer expires. If, however, we have a rack
5965 	 * timer running, then we don't even want a sack to wake
5966 	 * us since the rack timer has to expire before we can send.
5967 	 *
5968 	 * Other cases should usually have none of the flags set
5969 	 * so LRO can call into us.
5970 	 */
5971 	inp->inp_flags2 &= ~(INP_DONT_SACK_QUEUE|INP_MBUF_QUEUE_READY);
5972 	if (slot) {
5973 		rack->r_ctl.rc_last_output_to = us_cts + slot;
5974 		/*
5975 		 * A pacing timer (slot) is being set, in
5976 		 * such a case we cannot send (we are blocked by
5977 		 * the timer). So lets tell LRO that it should not
5978 		 * wake us unless there is a SACK. Note this only
5979 		 * will be effective if mbuf queueing is on or
5980 		 * compressed acks are being processed.
5981 		 */
5982 		inp->inp_flags2 |= INP_MBUF_QUEUE_READY;
5983 		/*
5984 		 * But wait if we have a Rack timer running
5985 		 * even a SACK should not disturb us (with
5986 		 * the exception of r_rr_config 3).
5987 		 */
5988 		if ((rack->r_ctl.rc_hpts_flags & PACE_TMR_RACK) &&
5989 		    (rack->r_rr_config != 3))
5990 			inp->inp_flags2 |= INP_DONT_SACK_QUEUE;
5991 		if (rack->rc_ack_can_sendout_data) {
5992 			/*
5993 			 * Ahh but wait, this is that special case
5994 			 * where the pacing timer can be disturbed
5995 			 * backout the changes (used for non-paced
5996 			 * burst limiting).
5997 			 */
5998 			inp->inp_flags2 &= ~(INP_DONT_SACK_QUEUE|INP_MBUF_QUEUE_READY);
5999 		}
6000 		if ((rack->use_rack_rr) &&
6001 		    (rack->r_rr_config < 2) &&
6002 		    ((hpts_timeout) && (hpts_timeout < slot))) {
6003 			/*
6004 			 * Arrange for the hpts to kick back in after the
6005 			 * t-o if the t-o does not cause a send.
6006 			 */
6007 			(void)tcp_hpts_insert_diag(tp->t_inpcb, HPTS_USEC_TO_SLOTS(hpts_timeout),
6008 						   __LINE__, &diag);
6009 			rack_log_hpts_diag(rack, us_cts, &diag, &tv);
6010 			rack_log_to_start(rack, cts, hpts_timeout, slot, 0);
6011 		} else {
6012 			(void)tcp_hpts_insert_diag(tp->t_inpcb, HPTS_USEC_TO_SLOTS(slot),
6013 						   __LINE__, &diag);
6014 			rack_log_hpts_diag(rack, us_cts, &diag, &tv);
6015 			rack_log_to_start(rack, cts, hpts_timeout, slot, 1);
6016 		}
6017 	} else if (hpts_timeout) {
6018 		/*
6019 		 * With respect to inp_flags2 here, lets let any new acks wake
6020 		 * us up here. Since we are not pacing (no pacing timer), output
6021 		 * can happen so we should let it. If its a Rack timer, then any inbound
6022 		 * packet probably won't change the sending (we will be blocked)
6023 		 * but it may change the prr stats so letting it in (the set defaults
6024 		 * at the start of this block) are good enough.
6025 		 */
6026 		(void)tcp_hpts_insert_diag(tp->t_inpcb, HPTS_USEC_TO_SLOTS(hpts_timeout),
6027 					   __LINE__, &diag);
6028 		rack_log_hpts_diag(rack, us_cts, &diag, &tv);
6029 		rack_log_to_start(rack, cts, hpts_timeout, slot, 0);
6030 	} else {
6031 		/* No timer starting */
6032 #ifdef INVARIANTS
6033 		if (SEQ_GT(tp->snd_max, tp->snd_una)) {
6034 			panic("tp:%p rack:%p tlts:%d cts:%u slot:%u pto:%u -- no timer started?",
6035 			    tp, rack, tot_len_this_send, cts, slot, hpts_timeout);
6036 		}
6037 #endif
6038 	}
6039 	rack->rc_tmr_stopped = 0;
6040 	if (slot)
6041 		rack_log_type_bbrsnd(rack, tot_len_this_send, slot, us_cts, &tv);
6042 }
6043 
6044 /*
6045  * RACK Timer, here we simply do logging and house keeping.
6046  * the normal rack_output() function will call the
6047  * appropriate thing to check if we need to do a RACK retransmit.
6048  * We return 1, saying don't proceed with rack_output only
6049  * when all timers have been stopped (destroyed PCB?).
6050  */
6051 static int
6052 rack_timeout_rack(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cts)
6053 {
6054 	/*
6055 	 * This timer simply provides an internal trigger to send out data.
6056 	 * The check_recovery_mode call will see if there are needed
6057 	 * retransmissions, if so we will enter fast-recovery. The output
6058 	 * call may or may not do the same thing depending on sysctl
6059 	 * settings.
6060 	 */
6061 	struct rack_sendmap *rsm;
6062 
6063 	if (tp->t_timers->tt_flags & TT_STOPPED) {
6064 		return (1);
6065 	}
6066 	counter_u64_add(rack_to_tot, 1);
6067 	if (rack->r_state && (rack->r_state != tp->t_state))
6068 		rack_set_state(tp, rack);
6069 	rack->rc_on_min_to = 0;
6070 	rsm = rack_check_recovery_mode(tp, cts);
6071 	rack_log_to_event(rack, RACK_TO_FRM_RACK, rsm);
6072 	if (rsm) {
6073 		rack->r_ctl.rc_resend = rsm;
6074 		rack->r_timer_override = 1;
6075 		if (rack->use_rack_rr) {
6076 			/*
6077 			 * Don't accumulate extra pacing delay
6078 			 * we are allowing the rack timer to
6079 			 * over-ride pacing i.e. rrr takes precedence
6080 			 * if the pacing interval is longer than the rrr
6081 			 * time (in other words we get the min pacing
6082 			 * time versus rrr pacing time).
6083 			 */
6084 			rack->r_ctl.rc_hpts_flags &= ~PACE_PKT_OUTPUT;
6085 		}
6086 	}
6087 	rack->r_ctl.rc_hpts_flags &= ~PACE_TMR_RACK;
6088 	if (rsm == NULL) {
6089 		/* restart a timer and return 1 */
6090 		rack_start_hpts_timer(rack, tp, cts,
6091 				      0, 0, 0);
6092 		return (1);
6093 	}
6094 	return (0);
6095 }
6096 
6097 static void
6098 rack_adjust_orig_mlen(struct rack_sendmap *rsm)
6099 {
6100 	if (rsm->m->m_len > rsm->orig_m_len) {
6101 		/*
6102 		 * Mbuf grew, caused by sbcompress, our offset does
6103 		 * not change.
6104 		 */
6105 		rsm->orig_m_len = rsm->m->m_len;
6106 	} else if (rsm->m->m_len < rsm->orig_m_len) {
6107 		/*
6108 		 * Mbuf shrank, trimmed off the top by an ack, our
6109 		 * offset changes.
6110 		 */
6111 		rsm->soff -= (rsm->orig_m_len - rsm->m->m_len);
6112 		rsm->orig_m_len = rsm->m->m_len;
6113 	}
6114 }
6115 
6116 static void
6117 rack_setup_offset_for_rsm(struct rack_sendmap *src_rsm, struct rack_sendmap *rsm)
6118 {
6119 	struct mbuf *m;
6120 	uint32_t soff;
6121 
6122 	if (src_rsm->m && (src_rsm->orig_m_len != src_rsm->m->m_len)) {
6123 		/* Fix up the orig_m_len and possibly the mbuf offset */
6124 		rack_adjust_orig_mlen(src_rsm);
6125 	}
6126 	m = src_rsm->m;
6127 	soff = src_rsm->soff + (src_rsm->r_end - src_rsm->r_start);
6128 	while (soff >= m->m_len) {
6129 		/* Move out past this mbuf */
6130 		soff -= m->m_len;
6131 		m = m->m_next;
6132 		KASSERT((m != NULL),
6133 			("rsm:%p nrsm:%p hit at soff:%u null m",
6134 			 src_rsm, rsm, soff));
6135 	}
6136 	rsm->m = m;
6137 	rsm->soff = soff;
6138 	rsm->orig_m_len = m->m_len;
6139 }
6140 
6141 static __inline void
6142 rack_clone_rsm(struct tcp_rack *rack, struct rack_sendmap *nrsm,
6143 	       struct rack_sendmap *rsm, uint32_t start)
6144 {
6145 	int idx;
6146 
6147 	nrsm->r_start = start;
6148 	nrsm->r_end = rsm->r_end;
6149 	nrsm->r_rtr_cnt = rsm->r_rtr_cnt;
6150 	nrsm->r_flags = rsm->r_flags;
6151 	nrsm->r_dupack = rsm->r_dupack;
6152 	nrsm->r_no_rtt_allowed = rsm->r_no_rtt_allowed;
6153 	nrsm->r_rtr_bytes = 0;
6154 	nrsm->r_fas = rsm->r_fas;
6155 	rsm->r_end = nrsm->r_start;
6156 	nrsm->r_just_ret = rsm->r_just_ret;
6157 	for (idx = 0; idx < nrsm->r_rtr_cnt; idx++) {
6158 		nrsm->r_tim_lastsent[idx] = rsm->r_tim_lastsent[idx];
6159 	}
6160 	/* Now if we have SYN flag we keep it on the left edge */
6161 	if (nrsm->r_flags & RACK_HAS_SYN)
6162 		nrsm->r_flags &= ~RACK_HAS_SYN;
6163 	/* Now if we have a FIN flag we keep it on the right edge */
6164 	if (rsm->r_flags & RACK_HAS_FIN)
6165 		rsm->r_flags &= ~RACK_HAS_FIN;
6166 	/* Push bit must go to the right edge as well */
6167 	if (rsm->r_flags & RACK_HAD_PUSH)
6168 		rsm->r_flags &= ~RACK_HAD_PUSH;
6169 	/* Clone over the state of the hw_tls flag */
6170 	nrsm->r_hw_tls = rsm->r_hw_tls;
6171 	/*
6172 	 * Now we need to find nrsm's new location in the mbuf chain
6173 	 * we basically calculate a new offset, which is soff +
6174 	 * how much is left in original rsm. Then we walk out the mbuf
6175 	 * chain to find the righ postion, it may be the same mbuf
6176 	 * or maybe not.
6177 	 */
6178 	KASSERT(((rsm->m != NULL) ||
6179 		 (rsm->r_flags & (RACK_HAS_SYN|RACK_HAS_FIN))),
6180 		("rsm:%p nrsm:%p rack:%p -- rsm->m is NULL?", rsm, nrsm, rack));
6181 	if (rsm->m)
6182 		rack_setup_offset_for_rsm(rsm, nrsm);
6183 }
6184 
6185 static struct rack_sendmap *
6186 rack_merge_rsm(struct tcp_rack *rack,
6187 	       struct rack_sendmap *l_rsm,
6188 	       struct rack_sendmap *r_rsm)
6189 {
6190 	/*
6191 	 * We are merging two ack'd RSM's,
6192 	 * the l_rsm is on the left (lower seq
6193 	 * values) and the r_rsm is on the right
6194 	 * (higher seq value). The simplest way
6195 	 * to merge these is to move the right
6196 	 * one into the left. I don't think there
6197 	 * is any reason we need to try to find
6198 	 * the oldest (or last oldest retransmitted).
6199 	 */
6200 	struct rack_sendmap *rm;
6201 
6202 	rack_log_map_chg(rack->rc_tp, rack, NULL,
6203 			 l_rsm, r_rsm, MAP_MERGE, r_rsm->r_end, __LINE__);
6204 	l_rsm->r_end = r_rsm->r_end;
6205 	if (l_rsm->r_dupack < r_rsm->r_dupack)
6206 		l_rsm->r_dupack = r_rsm->r_dupack;
6207 	if (r_rsm->r_rtr_bytes)
6208 		l_rsm->r_rtr_bytes += r_rsm->r_rtr_bytes;
6209 	if (r_rsm->r_in_tmap) {
6210 		/* This really should not happen */
6211 		TAILQ_REMOVE(&rack->r_ctl.rc_tmap, r_rsm, r_tnext);
6212 		r_rsm->r_in_tmap = 0;
6213 	}
6214 
6215 	/* Now the flags */
6216 	if (r_rsm->r_flags & RACK_HAS_FIN)
6217 		l_rsm->r_flags |= RACK_HAS_FIN;
6218 	if (r_rsm->r_flags & RACK_TLP)
6219 		l_rsm->r_flags |= RACK_TLP;
6220 	if (r_rsm->r_flags & RACK_RWND_COLLAPSED)
6221 		l_rsm->r_flags |= RACK_RWND_COLLAPSED;
6222 	if ((r_rsm->r_flags & RACK_APP_LIMITED)  &&
6223 	    ((l_rsm->r_flags & RACK_APP_LIMITED) == 0)) {
6224 		/*
6225 		 * If both are app-limited then let the
6226 		 * free lower the count. If right is app
6227 		 * limited and left is not, transfer.
6228 		 */
6229 		l_rsm->r_flags |= RACK_APP_LIMITED;
6230 		r_rsm->r_flags &= ~RACK_APP_LIMITED;
6231 		if (r_rsm == rack->r_ctl.rc_first_appl)
6232 			rack->r_ctl.rc_first_appl = l_rsm;
6233 	}
6234 	rm = RB_REMOVE(rack_rb_tree_head, &rack->r_ctl.rc_mtree, r_rsm);
6235 #ifdef INVARIANTS
6236 	if (rm != r_rsm) {
6237 		panic("removing head in rack:%p rsm:%p rm:%p",
6238 		      rack, r_rsm, rm);
6239 	}
6240 #endif
6241 	if ((r_rsm->r_limit_type == 0) && (l_rsm->r_limit_type != 0)) {
6242 		/* Transfer the split limit to the map we free */
6243 		r_rsm->r_limit_type = l_rsm->r_limit_type;
6244 		l_rsm->r_limit_type = 0;
6245 	}
6246 	rack_free(rack, r_rsm);
6247 	return (l_rsm);
6248 }
6249 
6250 /*
6251  * TLP Timer, here we simply setup what segment we want to
6252  * have the TLP expire on, the normal rack_output() will then
6253  * send it out.
6254  *
6255  * We return 1, saying don't proceed with rack_output only
6256  * when all timers have been stopped (destroyed PCB?).
6257  */
6258 static int
6259 rack_timeout_tlp(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cts, uint8_t *doing_tlp)
6260 {
6261 	/*
6262 	 * Tail Loss Probe.
6263 	 */
6264 	struct rack_sendmap *rsm = NULL;
6265 	struct rack_sendmap *insret;
6266 	struct socket *so;
6267 	uint32_t amm;
6268 	uint32_t out, avail;
6269 	int collapsed_win = 0;
6270 
6271 	if (tp->t_timers->tt_flags & TT_STOPPED) {
6272 		return (1);
6273 	}
6274 	if (TSTMP_LT(cts, rack->r_ctl.rc_timer_exp)) {
6275 		/* Its not time yet */
6276 		return (0);
6277 	}
6278 	if (ctf_progress_timeout_check(tp, true)) {
6279 		rack_log_progress_event(rack, tp, tick, PROGRESS_DROP, __LINE__);
6280 		tcp_set_inp_to_drop(tp->t_inpcb, ETIMEDOUT);
6281 		return (1);
6282 	}
6283 	/*
6284 	 * A TLP timer has expired. We have been idle for 2 rtts. So we now
6285 	 * need to figure out how to force a full MSS segment out.
6286 	 */
6287 	rack_log_to_event(rack, RACK_TO_FRM_TLP, NULL);
6288 	rack->r_ctl.retran_during_recovery = 0;
6289 	rack->r_ctl.dsack_byte_cnt = 0;
6290 	counter_u64_add(rack_tlp_tot, 1);
6291 	if (rack->r_state && (rack->r_state != tp->t_state))
6292 		rack_set_state(tp, rack);
6293 	so = tp->t_inpcb->inp_socket;
6294 	avail = sbavail(&so->so_snd);
6295 	out = tp->snd_max - tp->snd_una;
6296 	if (out > tp->snd_wnd) {
6297 		/* special case, we need a retransmission */
6298 		collapsed_win = 1;
6299 		goto need_retran;
6300 	}
6301 	if (rack->r_ctl.dsack_persist && (rack->r_ctl.rc_tlp_cnt_out >= 1)) {
6302 		rack->r_ctl.dsack_persist--;
6303 		if (rack->r_ctl.num_dsack && (rack->r_ctl.dsack_persist == 0)) {
6304 			rack->r_ctl.num_dsack = 0;
6305 		}
6306 		rack_log_dsack_event(rack, 1, __LINE__, 0, 0);
6307 	}
6308 	if ((tp->t_flags & TF_GPUTINPROG) &&
6309 	    (rack->r_ctl.rc_tlp_cnt_out == 1)) {
6310 		/*
6311 		 * If this is the second in a row
6312 		 * TLP and we are doing a measurement
6313 		 * its time to abandon the measurement.
6314 		 * Something is likely broken on
6315 		 * the clients network and measuring a
6316 		 * broken network does us no good.
6317 		 */
6318 		tp->t_flags &= ~TF_GPUTINPROG;
6319 		rack_log_pacing_delay_calc(rack, (tp->gput_ack - tp->gput_seq) /*flex2*/,
6320 					   rack->r_ctl.rc_gp_srtt /*flex1*/,
6321 					   tp->gput_seq,
6322 					   0, 0, 18, __LINE__, NULL, 0);
6323 	}
6324 	/*
6325 	 * Check our send oldest always settings, and if
6326 	 * there is an oldest to send jump to the need_retran.
6327 	 */
6328 	if (rack_always_send_oldest && (TAILQ_EMPTY(&rack->r_ctl.rc_tmap) == 0))
6329 		goto need_retran;
6330 
6331 	if (avail > out) {
6332 		/* New data is available */
6333 		amm = avail - out;
6334 		if (amm > ctf_fixed_maxseg(tp)) {
6335 			amm = ctf_fixed_maxseg(tp);
6336 			if ((amm + out) > tp->snd_wnd) {
6337 				/* We are rwnd limited */
6338 				goto need_retran;
6339 			}
6340 		} else if (amm < ctf_fixed_maxseg(tp)) {
6341 			/* not enough to fill a MTU */
6342 			goto need_retran;
6343 		}
6344 		if (IN_FASTRECOVERY(tp->t_flags)) {
6345 			/* Unlikely */
6346 			if (rack->rack_no_prr == 0) {
6347 				if (out + amm <= tp->snd_wnd) {
6348 					rack->r_ctl.rc_prr_sndcnt = amm;
6349 					rack->r_ctl.rc_tlp_new_data = amm;
6350 					rack_log_to_prr(rack, 4, 0);
6351 				}
6352 			} else
6353 				goto need_retran;
6354 		} else {
6355 			/* Set the send-new override */
6356 			if (out + amm <= tp->snd_wnd)
6357 				rack->r_ctl.rc_tlp_new_data = amm;
6358 			else
6359 				goto need_retran;
6360 		}
6361 		rack->r_ctl.rc_tlpsend = NULL;
6362 		counter_u64_add(rack_tlp_newdata, 1);
6363 		goto send;
6364 	}
6365 need_retran:
6366 	/*
6367 	 * Ok we need to arrange the last un-acked segment to be re-sent, or
6368 	 * optionally the first un-acked segment.
6369 	 */
6370 	if (collapsed_win == 0) {
6371 		if (rack_always_send_oldest)
6372 			rsm = TAILQ_FIRST(&rack->r_ctl.rc_tmap);
6373 		else {
6374 			rsm = RB_MAX(rack_rb_tree_head, &rack->r_ctl.rc_mtree);
6375 			if (rsm && (rsm->r_flags & (RACK_ACKED | RACK_HAS_FIN))) {
6376 				rsm = rack_find_high_nonack(rack, rsm);
6377 			}
6378 		}
6379 		if (rsm == NULL) {
6380 			counter_u64_add(rack_tlp_does_nada, 1);
6381 #ifdef TCP_BLACKBOX
6382 			tcp_log_dump_tp_logbuf(tp, "nada counter trips", M_NOWAIT, true);
6383 #endif
6384 			goto out;
6385 		}
6386 	} else {
6387 		/*
6388 		 * We must find the last segment
6389 		 * that was acceptable by the client.
6390 		 */
6391 		RB_FOREACH_REVERSE(rsm, rack_rb_tree_head, &rack->r_ctl.rc_mtree) {
6392 			if ((rsm->r_flags & RACK_RWND_COLLAPSED) == 0) {
6393 				/* Found one */
6394 				break;
6395 			}
6396 		}
6397 		if (rsm == NULL) {
6398 			/* None? if so send the first */
6399 			rsm = RB_MIN(rack_rb_tree_head, &rack->r_ctl.rc_mtree);
6400 			if (rsm == NULL) {
6401 				counter_u64_add(rack_tlp_does_nada, 1);
6402 #ifdef TCP_BLACKBOX
6403 				tcp_log_dump_tp_logbuf(tp, "nada counter trips", M_NOWAIT, true);
6404 #endif
6405 				goto out;
6406 			}
6407 		}
6408 	}
6409 	if ((rsm->r_end - rsm->r_start) > ctf_fixed_maxseg(tp)) {
6410 		/*
6411 		 * We need to split this the last segment in two.
6412 		 */
6413 		struct rack_sendmap *nrsm;
6414 
6415 		nrsm = rack_alloc_full_limit(rack);
6416 		if (nrsm == NULL) {
6417 			/*
6418 			 * No memory to split, we will just exit and punt
6419 			 * off to the RXT timer.
6420 			 */
6421 			counter_u64_add(rack_tlp_does_nada, 1);
6422 			goto out;
6423 		}
6424 		rack_clone_rsm(rack, nrsm, rsm,
6425 			       (rsm->r_end - ctf_fixed_maxseg(tp)));
6426 		rack_log_map_chg(tp, rack, NULL, rsm, nrsm, MAP_SPLIT, 0, __LINE__);
6427 		insret = RB_INSERT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, nrsm);
6428 #ifdef INVARIANTS
6429 		if (insret != NULL) {
6430 			panic("Insert in rb tree of %p fails ret:%p rack:%p rsm:%p",
6431 			      nrsm, insret, rack, rsm);
6432 		}
6433 #endif
6434 		if (rsm->r_in_tmap) {
6435 			TAILQ_INSERT_AFTER(&rack->r_ctl.rc_tmap, rsm, nrsm, r_tnext);
6436 			nrsm->r_in_tmap = 1;
6437 		}
6438 		rsm = nrsm;
6439 	}
6440 	rack->r_ctl.rc_tlpsend = rsm;
6441 send:
6442 	/* Make sure output path knows we are doing a TLP */
6443 	*doing_tlp = 1;
6444 	rack->r_timer_override = 1;
6445 	rack->r_ctl.rc_hpts_flags &= ~PACE_TMR_TLP;
6446 	return (0);
6447 out:
6448 	rack->r_ctl.rc_hpts_flags &= ~PACE_TMR_TLP;
6449 	return (0);
6450 }
6451 
6452 /*
6453  * Delayed ack Timer, here we simply need to setup the
6454  * ACK_NOW flag and remove the DELACK flag. From there
6455  * the output routine will send the ack out.
6456  *
6457  * We only return 1, saying don't proceed, if all timers
6458  * are stopped (destroyed PCB?).
6459  */
6460 static int
6461 rack_timeout_delack(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cts)
6462 {
6463 	if (tp->t_timers->tt_flags & TT_STOPPED) {
6464 		return (1);
6465 	}
6466 	rack_log_to_event(rack, RACK_TO_FRM_DELACK, NULL);
6467 	tp->t_flags &= ~TF_DELACK;
6468 	tp->t_flags |= TF_ACKNOW;
6469 	KMOD_TCPSTAT_INC(tcps_delack);
6470 	rack->r_ctl.rc_hpts_flags &= ~PACE_TMR_DELACK;
6471 	return (0);
6472 }
6473 
6474 /*
6475  * Persists timer, here we simply send the
6476  * same thing as a keepalive will.
6477  * the one byte send.
6478  *
6479  * We only return 1, saying don't proceed, if all timers
6480  * are stopped (destroyed PCB?).
6481  */
6482 static int
6483 rack_timeout_persist(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cts)
6484 {
6485 	struct tcptemp *t_template;
6486 	struct inpcb *inp;
6487 	int32_t retval = 1;
6488 
6489 	inp = tp->t_inpcb;
6490 
6491 	if (tp->t_timers->tt_flags & TT_STOPPED) {
6492 		return (1);
6493 	}
6494 	if (rack->rc_in_persist == 0)
6495 		return (0);
6496 	if (ctf_progress_timeout_check(tp, false)) {
6497 		tcp_log_end_status(tp, TCP_EI_STATUS_PERSIST_MAX);
6498 		rack_log_progress_event(rack, tp, tick, PROGRESS_DROP, __LINE__);
6499 		tcp_set_inp_to_drop(inp, ETIMEDOUT);
6500 		return (1);
6501 	}
6502 	KASSERT(inp != NULL, ("%s: tp %p tp->t_inpcb == NULL", __func__, tp));
6503 	/*
6504 	 * Persistence timer into zero window. Force a byte to be output, if
6505 	 * possible.
6506 	 */
6507 	KMOD_TCPSTAT_INC(tcps_persisttimeo);
6508 	/*
6509 	 * Hack: if the peer is dead/unreachable, we do not time out if the
6510 	 * window is closed.  After a full backoff, drop the connection if
6511 	 * the idle time (no responses to probes) reaches the maximum
6512 	 * backoff that we would use if retransmitting.
6513 	 */
6514 	if (tp->t_rxtshift == TCP_MAXRXTSHIFT &&
6515 	    (ticks - tp->t_rcvtime >= tcp_maxpersistidle ||
6516 	     TICKS_2_USEC(ticks - tp->t_rcvtime) >= RACK_REXMTVAL(tp) * tcp_totbackoff)) {
6517 		KMOD_TCPSTAT_INC(tcps_persistdrop);
6518 		retval = 1;
6519 		tcp_log_end_status(tp, TCP_EI_STATUS_PERSIST_MAX);
6520 		tcp_set_inp_to_drop(rack->rc_inp, ETIMEDOUT);
6521 		goto out;
6522 	}
6523 	if ((sbavail(&rack->rc_inp->inp_socket->so_snd) == 0) &&
6524 	    tp->snd_una == tp->snd_max)
6525 		rack_exit_persist(tp, rack, cts);
6526 	rack->r_ctl.rc_hpts_flags &= ~PACE_TMR_PERSIT;
6527 	/*
6528 	 * If the user has closed the socket then drop a persisting
6529 	 * connection after a much reduced timeout.
6530 	 */
6531 	if (tp->t_state > TCPS_CLOSE_WAIT &&
6532 	    (ticks - tp->t_rcvtime) >= TCPTV_PERSMAX) {
6533 		retval = 1;
6534 		KMOD_TCPSTAT_INC(tcps_persistdrop);
6535 		tcp_log_end_status(tp, TCP_EI_STATUS_PERSIST_MAX);
6536 		tcp_set_inp_to_drop(rack->rc_inp, ETIMEDOUT);
6537 		goto out;
6538 	}
6539 	t_template = tcpip_maketemplate(rack->rc_inp);
6540 	if (t_template) {
6541 		/* only set it if we were answered */
6542 		if (rack->forced_ack == 0) {
6543 			rack->forced_ack = 1;
6544 			rack->r_ctl.forced_ack_ts = tcp_get_usecs(NULL);
6545 		}
6546 		tcp_respond(tp, t_template->tt_ipgen,
6547 			    &t_template->tt_t, (struct mbuf *)NULL,
6548 			    tp->rcv_nxt, tp->snd_una - 1, 0);
6549 		/* This sends an ack */
6550 		if (tp->t_flags & TF_DELACK)
6551 			tp->t_flags &= ~TF_DELACK;
6552 		free(t_template, M_TEMP);
6553 	}
6554 	if (tp->t_rxtshift < TCP_MAXRXTSHIFT)
6555 		tp->t_rxtshift++;
6556 out:
6557 	rack_log_to_event(rack, RACK_TO_FRM_PERSIST, NULL);
6558 	rack_start_hpts_timer(rack, tp, cts,
6559 			      0, 0, 0);
6560 	return (retval);
6561 }
6562 
6563 /*
6564  * If a keepalive goes off, we had no other timers
6565  * happening. We always return 1 here since this
6566  * routine either drops the connection or sends
6567  * out a segment with respond.
6568  */
6569 static int
6570 rack_timeout_keepalive(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cts)
6571 {
6572 	struct tcptemp *t_template;
6573 	struct inpcb *inp;
6574 
6575 	if (tp->t_timers->tt_flags & TT_STOPPED) {
6576 		return (1);
6577 	}
6578 	rack->r_ctl.rc_hpts_flags &= ~PACE_TMR_KEEP;
6579 	inp = tp->t_inpcb;
6580 	rack_log_to_event(rack, RACK_TO_FRM_KEEP, NULL);
6581 	/*
6582 	 * Keep-alive timer went off; send something or drop connection if
6583 	 * idle for too long.
6584 	 */
6585 	KMOD_TCPSTAT_INC(tcps_keeptimeo);
6586 	if (tp->t_state < TCPS_ESTABLISHED)
6587 		goto dropit;
6588 	if ((V_tcp_always_keepalive || inp->inp_socket->so_options & SO_KEEPALIVE) &&
6589 	    tp->t_state <= TCPS_CLOSING) {
6590 		if (ticks - tp->t_rcvtime >= TP_KEEPIDLE(tp) + TP_MAXIDLE(tp))
6591 			goto dropit;
6592 		/*
6593 		 * Send a packet designed to force a response if the peer is
6594 		 * up and reachable: either an ACK if the connection is
6595 		 * still alive, or an RST if the peer has closed the
6596 		 * connection due to timeout or reboot. Using sequence
6597 		 * number tp->snd_una-1 causes the transmitted zero-length
6598 		 * segment to lie outside the receive window; by the
6599 		 * protocol spec, this requires the correspondent TCP to
6600 		 * respond.
6601 		 */
6602 		KMOD_TCPSTAT_INC(tcps_keepprobe);
6603 		t_template = tcpip_maketemplate(inp);
6604 		if (t_template) {
6605 			if (rack->forced_ack == 0) {
6606 				rack->forced_ack = 1;
6607 				rack->r_ctl.forced_ack_ts = tcp_get_usecs(NULL);
6608 			}
6609 			tcp_respond(tp, t_template->tt_ipgen,
6610 			    &t_template->tt_t, (struct mbuf *)NULL,
6611 			    tp->rcv_nxt, tp->snd_una - 1, 0);
6612 			free(t_template, M_TEMP);
6613 		}
6614 	}
6615 	rack_start_hpts_timer(rack, tp, cts, 0, 0, 0);
6616 	return (1);
6617 dropit:
6618 	KMOD_TCPSTAT_INC(tcps_keepdrops);
6619 	tcp_log_end_status(tp, TCP_EI_STATUS_KEEP_MAX);
6620 	tcp_set_inp_to_drop(rack->rc_inp, ETIMEDOUT);
6621 	return (1);
6622 }
6623 
6624 /*
6625  * Retransmit helper function, clear up all the ack
6626  * flags and take care of important book keeping.
6627  */
6628 static void
6629 rack_remxt_tmr(struct tcpcb *tp)
6630 {
6631 	/*
6632 	 * The retransmit timer went off, all sack'd blocks must be
6633 	 * un-acked.
6634 	 */
6635 	struct rack_sendmap *rsm, *trsm = NULL;
6636 	struct tcp_rack *rack;
6637 
6638 	rack = (struct tcp_rack *)tp->t_fb_ptr;
6639 	rack_timer_cancel(tp, rack, tcp_get_usecs(NULL), __LINE__);
6640 	rack_log_to_event(rack, RACK_TO_FRM_TMR, NULL);
6641 	if (rack->r_state && (rack->r_state != tp->t_state))
6642 		rack_set_state(tp, rack);
6643 	/*
6644 	 * Ideally we would like to be able to
6645 	 * mark SACK-PASS on anything not acked here.
6646 	 *
6647 	 * However, if we do that we would burst out
6648 	 * all that data 1ms apart. This would be unwise,
6649 	 * so for now we will just let the normal rxt timer
6650 	 * and tlp timer take care of it.
6651 	 *
6652 	 * Also we really need to stick them back in sequence
6653 	 * order. This way we send in the proper order and any
6654 	 * sacks that come floating in will "re-ack" the data.
6655 	 * To do this we zap the tmap with an INIT and then
6656 	 * walk through and place every rsm in the RB tree
6657 	 * back in its seq ordered place.
6658 	 */
6659 	TAILQ_INIT(&rack->r_ctl.rc_tmap);
6660 	RB_FOREACH(rsm, rack_rb_tree_head, &rack->r_ctl.rc_mtree) {
6661 		rsm->r_dupack = 0;
6662 		rack_log_retran_reason(rack, rsm, __LINE__, 0, 2);
6663 		/* We must re-add it back to the tlist */
6664 		if (trsm == NULL) {
6665 			TAILQ_INSERT_HEAD(&rack->r_ctl.rc_tmap, rsm, r_tnext);
6666 		} else {
6667 			TAILQ_INSERT_AFTER(&rack->r_ctl.rc_tmap, trsm, rsm, r_tnext);
6668 		}
6669 		rsm->r_in_tmap = 1;
6670 		trsm = rsm;
6671 		if (rsm->r_flags & RACK_ACKED)
6672 			rsm->r_flags |= RACK_WAS_ACKED;
6673 		rsm->r_flags &= ~(RACK_ACKED | RACK_SACK_PASSED | RACK_WAS_SACKPASS);
6674 		rsm->r_flags |= RACK_MUST_RXT;
6675 	}
6676 	/* Clear the count (we just un-acked them) */
6677 	rack->r_ctl.rc_last_timeout_snduna = tp->snd_una;
6678 	rack->r_ctl.rc_sacked = 0;
6679 	rack->r_ctl.rc_sacklast = NULL;
6680 	rack->r_ctl.rc_agg_delayed = 0;
6681 	rack->r_early = 0;
6682 	rack->r_ctl.rc_agg_early = 0;
6683 	rack->r_late = 0;
6684 	/* Clear the tlp rtx mark */
6685 	rack->r_ctl.rc_resend = RB_MIN(rack_rb_tree_head, &rack->r_ctl.rc_mtree);
6686 	if (rack->r_ctl.rc_resend != NULL)
6687 		rack->r_ctl.rc_resend->r_flags |= RACK_TO_REXT;
6688 	rack->r_ctl.rc_prr_sndcnt = 0;
6689 	rack_log_to_prr(rack, 6, 0);
6690 	rack->r_timer_override = 1;
6691 	if ((((tp->t_flags & TF_SACK_PERMIT) == 0)
6692 #ifdef NETFLIX_EXP_DETECTION
6693 	    || (rack->sack_attack_disable != 0)
6694 #endif
6695 		    ) && ((tp->t_flags & TF_SENTFIN) == 0)) {
6696 		/*
6697 		 * For non-sack customers new data
6698 		 * needs to go out as retransmits until
6699 		 * we retransmit up to snd_max.
6700 		 */
6701 		rack->r_must_retran = 1;
6702 		rack->r_ctl.rc_out_at_rto = ctf_flight_size(rack->rc_tp,
6703 						rack->r_ctl.rc_sacked);
6704 	}
6705 	rack->r_ctl.rc_snd_max_at_rto = tp->snd_max;
6706 }
6707 
6708 static void
6709 rack_convert_rtts(struct tcpcb *tp)
6710 {
6711 	if (tp->t_srtt > 1) {
6712 		uint32_t val, frac;
6713 
6714 		val = tp->t_srtt >> TCP_RTT_SHIFT;
6715 		frac = tp->t_srtt & 0x1f;
6716 		tp->t_srtt = TICKS_2_USEC(val);
6717 		/*
6718 		 * frac is the fractional part of the srtt (if any)
6719 		 * but its in ticks and every bit represents
6720 		 * 1/32nd of a hz.
6721 		 */
6722 		if (frac) {
6723 			if (hz == 1000) {
6724 				frac = (((uint64_t)frac * (uint64_t)HPTS_USEC_IN_MSEC) / (uint64_t)TCP_RTT_SCALE);
6725 			} else {
6726 				frac = (((uint64_t)frac * (uint64_t)HPTS_USEC_IN_SEC) / ((uint64_t)(hz) * (uint64_t)TCP_RTT_SCALE));
6727 			}
6728 			tp->t_srtt += frac;
6729 		}
6730 	}
6731 	if (tp->t_rttvar) {
6732 		uint32_t val, frac;
6733 
6734 		val = tp->t_rttvar >> TCP_RTTVAR_SHIFT;
6735 		frac = tp->t_rttvar & 0x1f;
6736 		tp->t_rttvar = TICKS_2_USEC(val);
6737 		/*
6738 		 * frac is the fractional part of the srtt (if any)
6739 		 * but its in ticks and every bit represents
6740 		 * 1/32nd of a hz.
6741 		 */
6742 		if (frac) {
6743 			if (hz == 1000) {
6744 				frac = (((uint64_t)frac * (uint64_t)HPTS_USEC_IN_MSEC) / (uint64_t)TCP_RTT_SCALE);
6745 			} else {
6746 				frac = (((uint64_t)frac * (uint64_t)HPTS_USEC_IN_SEC) / ((uint64_t)(hz) * (uint64_t)TCP_RTT_SCALE));
6747 			}
6748 			tp->t_rttvar += frac;
6749 		}
6750 	}
6751 	tp->t_rxtcur = RACK_REXMTVAL(tp);
6752 	if (TCPS_HAVEESTABLISHED(tp->t_state)) {
6753 		tp->t_rxtcur += TICKS_2_USEC(tcp_rexmit_slop);
6754 	}
6755 	if (tp->t_rxtcur > rack_rto_max) {
6756 		tp->t_rxtcur = rack_rto_max;
6757 	}
6758 }
6759 
6760 static void
6761 rack_cc_conn_init(struct tcpcb *tp)
6762 {
6763 	struct tcp_rack *rack;
6764 	uint32_t srtt;
6765 
6766 	rack = (struct tcp_rack *)tp->t_fb_ptr;
6767 	srtt = tp->t_srtt;
6768 	cc_conn_init(tp);
6769 	/*
6770 	 * Now convert to rack's internal format,
6771 	 * if required.
6772 	 */
6773 	if ((srtt == 0) && (tp->t_srtt != 0))
6774 		rack_convert_rtts(tp);
6775 	/*
6776 	 * We want a chance to stay in slowstart as
6777 	 * we create a connection. TCP spec says that
6778 	 * initially ssthresh is infinite. For our
6779 	 * purposes that is the snd_wnd.
6780 	 */
6781 	if (tp->snd_ssthresh < tp->snd_wnd) {
6782 		tp->snd_ssthresh = tp->snd_wnd;
6783 	}
6784 	/*
6785 	 * We also want to assure a IW worth of
6786 	 * data can get inflight.
6787 	 */
6788 	if (rc_init_window(rack) < tp->snd_cwnd)
6789 		tp->snd_cwnd = rc_init_window(rack);
6790 }
6791 
6792 /*
6793  * Re-transmit timeout! If we drop the PCB we will return 1, otherwise
6794  * we will setup to retransmit the lowest seq number outstanding.
6795  */
6796 static int
6797 rack_timeout_rxt(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cts)
6798 {
6799 	int32_t rexmt;
6800 	struct inpcb *inp;
6801 	int32_t retval = 0;
6802 	bool isipv6;
6803 
6804 	inp = tp->t_inpcb;
6805 	if (tp->t_timers->tt_flags & TT_STOPPED) {
6806 		return (1);
6807 	}
6808 	if ((tp->t_flags & TF_GPUTINPROG) &&
6809 	    (tp->t_rxtshift)) {
6810 		/*
6811 		 * We have had a second timeout
6812 		 * measurements on successive rxt's are not profitable.
6813 		 * It is unlikely to be of any use (the network is
6814 		 * broken or the client went away).
6815 		 */
6816 		tp->t_flags &= ~TF_GPUTINPROG;
6817 		rack_log_pacing_delay_calc(rack, (tp->gput_ack - tp->gput_seq) /*flex2*/,
6818 					   rack->r_ctl.rc_gp_srtt /*flex1*/,
6819 					   tp->gput_seq,
6820 					   0, 0, 18, __LINE__, NULL, 0);
6821 	}
6822 	if (ctf_progress_timeout_check(tp, false)) {
6823 		tcp_log_end_status(tp, TCP_EI_STATUS_RETRAN);
6824 		rack_log_progress_event(rack, tp, tick, PROGRESS_DROP, __LINE__);
6825 		tcp_set_inp_to_drop(inp, ETIMEDOUT);
6826 		return (1);
6827 	}
6828 	rack->r_ctl.rc_hpts_flags &= ~PACE_TMR_RXT;
6829 	rack->r_ctl.retran_during_recovery = 0;
6830 	rack->r_ctl.dsack_byte_cnt = 0;
6831 	if (IN_FASTRECOVERY(tp->t_flags))
6832 		tp->t_flags |= TF_WASFRECOVERY;
6833 	else
6834 		tp->t_flags &= ~TF_WASFRECOVERY;
6835 	if (IN_CONGRECOVERY(tp->t_flags))
6836 		tp->t_flags |= TF_WASCRECOVERY;
6837 	else
6838 		tp->t_flags &= ~TF_WASCRECOVERY;
6839 	if (TCPS_HAVEESTABLISHED(tp->t_state) &&
6840 	    (tp->snd_una == tp->snd_max)) {
6841 		/* Nothing outstanding .. nothing to do */
6842 		return (0);
6843 	}
6844 	if (rack->r_ctl.dsack_persist) {
6845 		rack->r_ctl.dsack_persist--;
6846 		if (rack->r_ctl.num_dsack && (rack->r_ctl.dsack_persist == 0)) {
6847 			rack->r_ctl.num_dsack = 0;
6848 		}
6849 		rack_log_dsack_event(rack, 1, __LINE__, 0, 0);
6850 	}
6851 	/*
6852 	 * Rack can only run one timer  at a time, so we cannot
6853 	 * run a KEEPINIT (gating SYN sending) and a retransmit
6854 	 * timer for the SYN. So if we are in a front state and
6855 	 * have a KEEPINIT timer we need to check the first transmit
6856 	 * against now to see if we have exceeded the KEEPINIT time
6857 	 * (if one is set).
6858 	 */
6859 	if ((TCPS_HAVEESTABLISHED(tp->t_state) == 0) &&
6860 	    (TP_KEEPINIT(tp) != 0)) {
6861 		struct rack_sendmap *rsm;
6862 
6863 		rsm = RB_MIN(rack_rb_tree_head, &rack->r_ctl.rc_mtree);
6864 		if (rsm) {
6865 			/* Ok we have something outstanding to test keepinit with */
6866 			if ((TSTMP_GT(cts, (uint32_t)rsm->r_tim_lastsent[0])) &&
6867 			    ((cts - (uint32_t)rsm->r_tim_lastsent[0]) >= TICKS_2_USEC(TP_KEEPINIT(tp)))) {
6868 				/* We have exceeded the KEEPINIT time */
6869 				tcp_log_end_status(tp, TCP_EI_STATUS_KEEP_MAX);
6870 				goto drop_it;
6871 			}
6872 		}
6873 	}
6874 	/*
6875 	 * Retransmission timer went off.  Message has not been acked within
6876 	 * retransmit interval.  Back off to a longer retransmit interval
6877 	 * and retransmit one segment.
6878 	 */
6879 	rack_remxt_tmr(tp);
6880 	if ((rack->r_ctl.rc_resend == NULL) ||
6881 	    ((rack->r_ctl.rc_resend->r_flags & RACK_RWND_COLLAPSED) == 0)) {
6882 		/*
6883 		 * If the rwnd collapsed on
6884 		 * the one we are retransmitting
6885 		 * it does not count against the
6886 		 * rxt count.
6887 		 */
6888 		tp->t_rxtshift++;
6889 	}
6890 	if (tp->t_rxtshift > TCP_MAXRXTSHIFT) {
6891 		tcp_log_end_status(tp, TCP_EI_STATUS_RETRAN);
6892 drop_it:
6893 		tp->t_rxtshift = TCP_MAXRXTSHIFT;
6894 		KMOD_TCPSTAT_INC(tcps_timeoutdrop);
6895 		retval = 1;
6896 		tcp_set_inp_to_drop(rack->rc_inp,
6897 		    (tp->t_softerror ? (uint16_t) tp->t_softerror : ETIMEDOUT));
6898 		goto out;
6899 	}
6900 	if (tp->t_state == TCPS_SYN_SENT) {
6901 		/*
6902 		 * If the SYN was retransmitted, indicate CWND to be limited
6903 		 * to 1 segment in cc_conn_init().
6904 		 */
6905 		tp->snd_cwnd = 1;
6906 	} else if (tp->t_rxtshift == 1) {
6907 		/*
6908 		 * first retransmit; record ssthresh and cwnd so they can be
6909 		 * recovered if this turns out to be a "bad" retransmit. A
6910 		 * retransmit is considered "bad" if an ACK for this segment
6911 		 * is received within RTT/2 interval; the assumption here is
6912 		 * that the ACK was already in flight.  See "On Estimating
6913 		 * End-to-End Network Path Properties" by Allman and Paxson
6914 		 * for more details.
6915 		 */
6916 		tp->snd_cwnd_prev = tp->snd_cwnd;
6917 		tp->snd_ssthresh_prev = tp->snd_ssthresh;
6918 		tp->snd_recover_prev = tp->snd_recover;
6919 		tp->t_badrxtwin = ticks + (USEC_2_TICKS(tp->t_srtt)/2);
6920 		tp->t_flags |= TF_PREVVALID;
6921 	} else if ((tp->t_flags & TF_RCVD_TSTMP) == 0)
6922 		tp->t_flags &= ~TF_PREVVALID;
6923 	KMOD_TCPSTAT_INC(tcps_rexmttimeo);
6924 	if ((tp->t_state == TCPS_SYN_SENT) ||
6925 	    (tp->t_state == TCPS_SYN_RECEIVED))
6926 		rexmt = RACK_INITIAL_RTO * tcp_backoff[tp->t_rxtshift];
6927 	else
6928 		rexmt = max(rack_rto_min, (tp->t_srtt + (tp->t_rttvar << 2))) * tcp_backoff[tp->t_rxtshift];
6929 
6930 	RACK_TCPT_RANGESET(tp->t_rxtcur, rexmt,
6931 	   max(rack_rto_min, rexmt), rack_rto_max, rack->r_ctl.timer_slop);
6932 	/*
6933 	 * We enter the path for PLMTUD if connection is established or, if
6934 	 * connection is FIN_WAIT_1 status, reason for the last is that if
6935 	 * amount of data we send is very small, we could send it in couple
6936 	 * of packets and process straight to FIN. In that case we won't
6937 	 * catch ESTABLISHED state.
6938 	 */
6939 #ifdef INET6
6940 	isipv6 = (tp->t_inpcb->inp_vflag & INP_IPV6) ? true : false;
6941 #else
6942 	isipv6 = false;
6943 #endif
6944 	if (((V_tcp_pmtud_blackhole_detect == 1) ||
6945 	    (V_tcp_pmtud_blackhole_detect == 2 && !isipv6) ||
6946 	    (V_tcp_pmtud_blackhole_detect == 3 && isipv6)) &&
6947 	    ((tp->t_state == TCPS_ESTABLISHED) ||
6948 	    (tp->t_state == TCPS_FIN_WAIT_1))) {
6949 		/*
6950 		 * Idea here is that at each stage of mtu probe (usually,
6951 		 * 1448 -> 1188 -> 524) should be given 2 chances to recover
6952 		 * before further clamping down. 'tp->t_rxtshift % 2 == 0'
6953 		 * should take care of that.
6954 		 */
6955 		if (((tp->t_flags2 & (TF2_PLPMTU_PMTUD | TF2_PLPMTU_MAXSEGSNT)) ==
6956 		    (TF2_PLPMTU_PMTUD | TF2_PLPMTU_MAXSEGSNT)) &&
6957 		    (tp->t_rxtshift >= 2 && tp->t_rxtshift < 6 &&
6958 		    tp->t_rxtshift % 2 == 0)) {
6959 			/*
6960 			 * Enter Path MTU Black-hole Detection mechanism: -
6961 			 * Disable Path MTU Discovery (IP "DF" bit). -
6962 			 * Reduce MTU to lower value than what we negotiated
6963 			 * with peer.
6964 			 */
6965 			if ((tp->t_flags2 & TF2_PLPMTU_BLACKHOLE) == 0) {
6966 				/* Record that we may have found a black hole. */
6967 				tp->t_flags2 |= TF2_PLPMTU_BLACKHOLE;
6968 				/* Keep track of previous MSS. */
6969 				tp->t_pmtud_saved_maxseg = tp->t_maxseg;
6970 			}
6971 
6972 			/*
6973 			 * Reduce the MSS to blackhole value or to the
6974 			 * default in an attempt to retransmit.
6975 			 */
6976 #ifdef INET6
6977 			if (isipv6 &&
6978 			    tp->t_maxseg > V_tcp_v6pmtud_blackhole_mss) {
6979 				/* Use the sysctl tuneable blackhole MSS. */
6980 				tp->t_maxseg = V_tcp_v6pmtud_blackhole_mss;
6981 				KMOD_TCPSTAT_INC(tcps_pmtud_blackhole_activated);
6982 			} else if (isipv6) {
6983 				/* Use the default MSS. */
6984 				tp->t_maxseg = V_tcp_v6mssdflt;
6985 				/*
6986 				 * Disable Path MTU Discovery when we switch
6987 				 * to minmss.
6988 				 */
6989 				tp->t_flags2 &= ~TF2_PLPMTU_PMTUD;
6990 				KMOD_TCPSTAT_INC(tcps_pmtud_blackhole_activated_min_mss);
6991 			}
6992 #endif
6993 #if defined(INET6) && defined(INET)
6994 			else
6995 #endif
6996 #ifdef INET
6997 			if (tp->t_maxseg > V_tcp_pmtud_blackhole_mss) {
6998 				/* Use the sysctl tuneable blackhole MSS. */
6999 				tp->t_maxseg = V_tcp_pmtud_blackhole_mss;
7000 				KMOD_TCPSTAT_INC(tcps_pmtud_blackhole_activated);
7001 			} else {
7002 				/* Use the default MSS. */
7003 				tp->t_maxseg = V_tcp_mssdflt;
7004 				/*
7005 				 * Disable Path MTU Discovery when we switch
7006 				 * to minmss.
7007 				 */
7008 				tp->t_flags2 &= ~TF2_PLPMTU_PMTUD;
7009 				KMOD_TCPSTAT_INC(tcps_pmtud_blackhole_activated_min_mss);
7010 			}
7011 #endif
7012 		} else {
7013 			/*
7014 			 * If further retransmissions are still unsuccessful
7015 			 * with a lowered MTU, maybe this isn't a blackhole
7016 			 * and we restore the previous MSS and blackhole
7017 			 * detection flags. The limit '6' is determined by
7018 			 * giving each probe stage (1448, 1188, 524) 2
7019 			 * chances to recover.
7020 			 */
7021 			if ((tp->t_flags2 & TF2_PLPMTU_BLACKHOLE) &&
7022 			    (tp->t_rxtshift >= 6)) {
7023 				tp->t_flags2 |= TF2_PLPMTU_PMTUD;
7024 				tp->t_flags2 &= ~TF2_PLPMTU_BLACKHOLE;
7025 				tp->t_maxseg = tp->t_pmtud_saved_maxseg;
7026 				KMOD_TCPSTAT_INC(tcps_pmtud_blackhole_failed);
7027 			}
7028 		}
7029 	}
7030 	/*
7031 	 * Disable RFC1323 and SACK if we haven't got any response to
7032 	 * our third SYN to work-around some broken terminal servers
7033 	 * (most of which have hopefully been retired) that have bad VJ
7034 	 * header compression code which trashes TCP segments containing
7035 	 * unknown-to-them TCP options.
7036 	 */
7037 	if (tcp_rexmit_drop_options && (tp->t_state == TCPS_SYN_SENT) &&
7038 	    (tp->t_rxtshift == 3))
7039 		tp->t_flags &= ~(TF_REQ_SCALE|TF_REQ_TSTMP|TF_SACK_PERMIT);
7040 	/*
7041 	 * If we backed off this far, our srtt estimate is probably bogus.
7042 	 * Clobber it so we'll take the next rtt measurement as our srtt;
7043 	 * move the current srtt into rttvar to keep the current retransmit
7044 	 * times until then.
7045 	 */
7046 	if (tp->t_rxtshift > TCP_MAXRXTSHIFT / 4) {
7047 #ifdef INET6
7048 		if ((tp->t_inpcb->inp_vflag & INP_IPV6) != 0)
7049 			in6_losing(tp->t_inpcb);
7050 		else
7051 #endif
7052 			in_losing(tp->t_inpcb);
7053 		tp->t_rttvar += tp->t_srtt;
7054 		tp->t_srtt = 0;
7055 	}
7056 	sack_filter_clear(&rack->r_ctl.rack_sf, tp->snd_una);
7057 	tp->snd_recover = tp->snd_max;
7058 	tp->t_flags |= TF_ACKNOW;
7059 	tp->t_rtttime = 0;
7060 	rack_cong_signal(tp, CC_RTO, tp->snd_una);
7061 out:
7062 	return (retval);
7063 }
7064 
7065 static int
7066 rack_process_timers(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cts, uint8_t hpts_calling, uint8_t *doing_tlp)
7067 {
7068 	int32_t ret = 0;
7069 	int32_t timers = (rack->r_ctl.rc_hpts_flags & PACE_TMR_MASK);
7070 
7071 	if ((tp->t_state >= TCPS_FIN_WAIT_1) &&
7072 	    (tp->t_flags & TF_GPUTINPROG)) {
7073 		/*
7074 		 * We have a goodput in progress
7075 		 * and we have entered a late state.
7076 		 * Do we have enough data in the sb
7077 		 * to handle the GPUT request?
7078 		 */
7079 		uint32_t bytes;
7080 
7081 		bytes = tp->gput_ack - tp->gput_seq;
7082 		if (SEQ_GT(tp->gput_seq, tp->snd_una))
7083 			bytes += tp->gput_seq - tp->snd_una;
7084 		if (bytes > sbavail(&tp->t_inpcb->inp_socket->so_snd)) {
7085 			/*
7086 			 * There are not enough bytes in the socket
7087 			 * buffer that have been sent to cover this
7088 			 * measurement. Cancel it.
7089 			 */
7090 			rack_log_pacing_delay_calc(rack, (tp->gput_ack - tp->gput_seq) /*flex2*/,
7091 						   rack->r_ctl.rc_gp_srtt /*flex1*/,
7092 						   tp->gput_seq,
7093 						   0, 0, 18, __LINE__, NULL, 0);
7094 			tp->t_flags &= ~TF_GPUTINPROG;
7095 		}
7096 	}
7097 	if (timers == 0) {
7098 		return (0);
7099 	}
7100 	if (tp->t_state == TCPS_LISTEN) {
7101 		/* no timers on listen sockets */
7102 		if (rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT)
7103 			return (0);
7104 		return (1);
7105 	}
7106 	if ((timers & PACE_TMR_RACK) &&
7107 	    rack->rc_on_min_to) {
7108 		/*
7109 		 * For the rack timer when we
7110 		 * are on a min-timeout (which means rrr_conf = 3)
7111 		 * we don't want to check the timer. It may
7112 		 * be going off for a pace and thats ok we
7113 		 * want to send the retransmit (if its ready).
7114 		 *
7115 		 * If its on a normal rack timer (non-min) then
7116 		 * we will check if its expired.
7117 		 */
7118 		goto skip_time_check;
7119 	}
7120 	if (TSTMP_LT(cts, rack->r_ctl.rc_timer_exp)) {
7121 		uint32_t left;
7122 
7123 		if (rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT) {
7124 			ret = -1;
7125 			rack_log_to_processing(rack, cts, ret, 0);
7126 			return (0);
7127 		}
7128 		if (hpts_calling == 0) {
7129 			/*
7130 			 * A user send or queued mbuf (sack) has called us? We
7131 			 * return 0 and let the pacing guards
7132 			 * deal with it if they should or
7133 			 * should not cause a send.
7134 			 */
7135 			ret = -2;
7136 			rack_log_to_processing(rack, cts, ret, 0);
7137 			return (0);
7138 		}
7139 		/*
7140 		 * Ok our timer went off early and we are not paced false
7141 		 * alarm, go back to sleep.
7142 		 */
7143 		ret = -3;
7144 		left = rack->r_ctl.rc_timer_exp - cts;
7145 		tcp_hpts_insert(tp->t_inpcb, HPTS_MS_TO_SLOTS(left));
7146 		rack_log_to_processing(rack, cts, ret, left);
7147 		return (1);
7148 	}
7149 skip_time_check:
7150 	rack->rc_tmr_stopped = 0;
7151 	rack->r_ctl.rc_hpts_flags &= ~PACE_TMR_MASK;
7152 	if (timers & PACE_TMR_DELACK) {
7153 		ret = rack_timeout_delack(tp, rack, cts);
7154 	} else if (timers & PACE_TMR_RACK) {
7155 		rack->r_ctl.rc_tlp_rxt_last_time = cts;
7156 		rack->r_fast_output = 0;
7157 		ret = rack_timeout_rack(tp, rack, cts);
7158 	} else if (timers & PACE_TMR_TLP) {
7159 		rack->r_ctl.rc_tlp_rxt_last_time = cts;
7160 		ret = rack_timeout_tlp(tp, rack, cts, doing_tlp);
7161 	} else if (timers & PACE_TMR_RXT) {
7162 		rack->r_ctl.rc_tlp_rxt_last_time = cts;
7163 		rack->r_fast_output = 0;
7164 		ret = rack_timeout_rxt(tp, rack, cts);
7165 	} else if (timers & PACE_TMR_PERSIT) {
7166 		ret = rack_timeout_persist(tp, rack, cts);
7167 	} else if (timers & PACE_TMR_KEEP) {
7168 		ret = rack_timeout_keepalive(tp, rack, cts);
7169 	}
7170 	rack_log_to_processing(rack, cts, ret, timers);
7171 	return (ret);
7172 }
7173 
7174 static void
7175 rack_timer_cancel(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cts, int line)
7176 {
7177 	struct timeval tv;
7178 	uint32_t us_cts, flags_on_entry;
7179 	uint8_t hpts_removed = 0;
7180 
7181 	flags_on_entry = rack->r_ctl.rc_hpts_flags;
7182 	us_cts = tcp_get_usecs(&tv);
7183 	if ((rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT) &&
7184 	    ((TSTMP_GEQ(us_cts, rack->r_ctl.rc_last_output_to)) ||
7185 	     ((tp->snd_max - tp->snd_una) == 0))) {
7186 		tcp_hpts_remove(rack->rc_inp, HPTS_REMOVE_OUTPUT);
7187 		hpts_removed = 1;
7188 		/* If we were not delayed cancel out the flag. */
7189 		if ((tp->snd_max - tp->snd_una) == 0)
7190 			rack->r_ctl.rc_hpts_flags &= ~PACE_PKT_OUTPUT;
7191 		rack_log_to_cancel(rack, hpts_removed, line, us_cts, &tv, flags_on_entry);
7192 	}
7193 	if (rack->r_ctl.rc_hpts_flags & PACE_TMR_MASK) {
7194 		rack->rc_tmr_stopped = rack->r_ctl.rc_hpts_flags & PACE_TMR_MASK;
7195 		if (rack->rc_inp->inp_in_hpts &&
7196 		    ((rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT) == 0)) {
7197 			/*
7198 			 * Canceling timer's when we have no output being
7199 			 * paced. We also must remove ourselves from the
7200 			 * hpts.
7201 			 */
7202 			tcp_hpts_remove(rack->rc_inp, HPTS_REMOVE_OUTPUT);
7203 			hpts_removed = 1;
7204 		}
7205 		rack->r_ctl.rc_hpts_flags &= ~(PACE_TMR_MASK);
7206 	}
7207 	if (hpts_removed == 0)
7208 		rack_log_to_cancel(rack, hpts_removed, line, us_cts, &tv, flags_on_entry);
7209 }
7210 
7211 static void
7212 rack_timer_stop(struct tcpcb *tp, uint32_t timer_type)
7213 {
7214 	return;
7215 }
7216 
7217 static int
7218 rack_stopall(struct tcpcb *tp)
7219 {
7220 	struct tcp_rack *rack;
7221 	rack = (struct tcp_rack *)tp->t_fb_ptr;
7222 	rack->t_timers_stopped = 1;
7223 	return (0);
7224 }
7225 
7226 static void
7227 rack_timer_activate(struct tcpcb *tp, uint32_t timer_type, uint32_t delta)
7228 {
7229 	return;
7230 }
7231 
7232 static int
7233 rack_timer_active(struct tcpcb *tp, uint32_t timer_type)
7234 {
7235 	return (0);
7236 }
7237 
7238 static void
7239 rack_stop_all_timers(struct tcpcb *tp)
7240 {
7241 	struct tcp_rack *rack;
7242 
7243 	/*
7244 	 * Assure no timers are running.
7245 	 */
7246 	if (tcp_timer_active(tp, TT_PERSIST)) {
7247 		/* We enter in persists, set the flag appropriately */
7248 		rack = (struct tcp_rack *)tp->t_fb_ptr;
7249 		rack->rc_in_persist = 1;
7250 	}
7251 	tcp_timer_suspend(tp, TT_PERSIST);
7252 	tcp_timer_suspend(tp, TT_REXMT);
7253 	tcp_timer_suspend(tp, TT_KEEP);
7254 	tcp_timer_suspend(tp, TT_DELACK);
7255 }
7256 
7257 static void
7258 rack_update_rsm(struct tcpcb *tp, struct tcp_rack *rack,
7259     struct rack_sendmap *rsm, uint64_t ts, uint16_t add_flag)
7260 {
7261 	int32_t idx;
7262 
7263 	rsm->r_rtr_cnt++;
7264 	rack_log_retran_reason(rack, rsm, __LINE__, 0, 2);
7265 	rsm->r_dupack = 0;
7266 	if (rsm->r_rtr_cnt > RACK_NUM_OF_RETRANS) {
7267 		rsm->r_rtr_cnt = RACK_NUM_OF_RETRANS;
7268 		rsm->r_flags |= RACK_OVERMAX;
7269 	}
7270 	if ((rsm->r_rtr_cnt > 1) && ((rsm->r_flags & RACK_TLP) == 0)) {
7271 		rack->r_ctl.rc_holes_rxt += (rsm->r_end - rsm->r_start);
7272 		rsm->r_rtr_bytes += (rsm->r_end - rsm->r_start);
7273 	}
7274 	idx = rsm->r_rtr_cnt - 1;
7275 	rsm->r_tim_lastsent[idx] = ts;
7276 	/*
7277 	 * Here we don't add in the len of send, since its already
7278 	 * in snduna <->snd_max.
7279 	 */
7280 	rsm->r_fas = ctf_flight_size(rack->rc_tp,
7281 				     rack->r_ctl.rc_sacked);
7282 	if (rsm->r_flags & RACK_ACKED) {
7283 		/* Problably MTU discovery messing with us */
7284 		rsm->r_flags &= ~RACK_ACKED;
7285 		rack->r_ctl.rc_sacked -= (rsm->r_end - rsm->r_start);
7286 	}
7287 	if (rsm->r_in_tmap) {
7288 		TAILQ_REMOVE(&rack->r_ctl.rc_tmap, rsm, r_tnext);
7289 		rsm->r_in_tmap = 0;
7290 	}
7291 	TAILQ_INSERT_TAIL(&rack->r_ctl.rc_tmap, rsm, r_tnext);
7292 	rsm->r_in_tmap = 1;
7293 	if (rsm->r_flags & RACK_SACK_PASSED) {
7294 		/* We have retransmitted due to the SACK pass */
7295 		rsm->r_flags &= ~RACK_SACK_PASSED;
7296 		rsm->r_flags |= RACK_WAS_SACKPASS;
7297 	}
7298 }
7299 
7300 static uint32_t
7301 rack_update_entry(struct tcpcb *tp, struct tcp_rack *rack,
7302     struct rack_sendmap *rsm, uint64_t ts, int32_t *lenp, uint16_t add_flag)
7303 {
7304 	/*
7305 	 * We (re-)transmitted starting at rsm->r_start for some length
7306 	 * (possibly less than r_end.
7307 	 */
7308 	struct rack_sendmap *nrsm, *insret;
7309 	uint32_t c_end;
7310 	int32_t len;
7311 
7312 	len = *lenp;
7313 	c_end = rsm->r_start + len;
7314 	if (SEQ_GEQ(c_end, rsm->r_end)) {
7315 		/*
7316 		 * We retransmitted the whole piece or more than the whole
7317 		 * slopping into the next rsm.
7318 		 */
7319 		rack_update_rsm(tp, rack, rsm, ts, add_flag);
7320 		if (c_end == rsm->r_end) {
7321 			*lenp = 0;
7322 			return (0);
7323 		} else {
7324 			int32_t act_len;
7325 
7326 			/* Hangs over the end return whats left */
7327 			act_len = rsm->r_end - rsm->r_start;
7328 			*lenp = (len - act_len);
7329 			return (rsm->r_end);
7330 		}
7331 		/* We don't get out of this block. */
7332 	}
7333 	/*
7334 	 * Here we retransmitted less than the whole thing which means we
7335 	 * have to split this into what was transmitted and what was not.
7336 	 */
7337 	nrsm = rack_alloc_full_limit(rack);
7338 	if (nrsm == NULL) {
7339 		/*
7340 		 * We can't get memory, so lets not proceed.
7341 		 */
7342 		*lenp = 0;
7343 		return (0);
7344 	}
7345 	/*
7346 	 * So here we are going to take the original rsm and make it what we
7347 	 * retransmitted. nrsm will be the tail portion we did not
7348 	 * retransmit. For example say the chunk was 1, 11 (10 bytes). And
7349 	 * we retransmitted 5 bytes i.e. 1, 5. The original piece shrinks to
7350 	 * 1, 6 and the new piece will be 6, 11.
7351 	 */
7352 	rack_clone_rsm(rack, nrsm, rsm, c_end);
7353 	nrsm->r_dupack = 0;
7354 	rack_log_retran_reason(rack, nrsm, __LINE__, 0, 2);
7355 	insret = RB_INSERT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, nrsm);
7356 #ifdef INVARIANTS
7357 	if (insret != NULL) {
7358 		panic("Insert in rb tree of %p fails ret:%p rack:%p rsm:%p",
7359 		      nrsm, insret, rack, rsm);
7360 	}
7361 #endif
7362 	if (rsm->r_in_tmap) {
7363 		TAILQ_INSERT_AFTER(&rack->r_ctl.rc_tmap, rsm, nrsm, r_tnext);
7364 		nrsm->r_in_tmap = 1;
7365 	}
7366 	rsm->r_flags &= (~RACK_HAS_FIN);
7367 	rack_update_rsm(tp, rack, rsm, ts, add_flag);
7368 	/* Log a split of rsm into rsm and nrsm */
7369 	rack_log_map_chg(tp, rack, NULL, rsm, nrsm, MAP_SPLIT, 0, __LINE__);
7370 	*lenp = 0;
7371 	return (0);
7372 }
7373 
7374 static void
7375 rack_log_output(struct tcpcb *tp, struct tcpopt *to, int32_t len,
7376 		uint32_t seq_out, uint8_t th_flags, int32_t err, uint64_t cts,
7377 		struct rack_sendmap *hintrsm, uint16_t add_flag, struct mbuf *s_mb, uint32_t s_moff, int hw_tls)
7378 {
7379 	struct tcp_rack *rack;
7380 	struct rack_sendmap *rsm, *nrsm, *insret, fe;
7381 	register uint32_t snd_max, snd_una;
7382 
7383 	/*
7384 	 * Add to the RACK log of packets in flight or retransmitted. If
7385 	 * there is a TS option we will use the TS echoed, if not we will
7386 	 * grab a TS.
7387 	 *
7388 	 * Retransmissions will increment the count and move the ts to its
7389 	 * proper place. Note that if options do not include TS's then we
7390 	 * won't be able to effectively use the ACK for an RTT on a retran.
7391 	 *
7392 	 * Notes about r_start and r_end. Lets consider a send starting at
7393 	 * sequence 1 for 10 bytes. In such an example the r_start would be
7394 	 * 1 (starting sequence) but the r_end would be r_start+len i.e. 11.
7395 	 * This means that r_end is actually the first sequence for the next
7396 	 * slot (11).
7397 	 *
7398 	 */
7399 	/*
7400 	 * If err is set what do we do XXXrrs? should we not add the thing?
7401 	 * -- i.e. return if err != 0 or should we pretend we sent it? --
7402 	 * i.e. proceed with add ** do this for now.
7403 	 */
7404 	INP_WLOCK_ASSERT(tp->t_inpcb);
7405 	if (err)
7406 		/*
7407 		 * We don't log errors -- we could but snd_max does not
7408 		 * advance in this case either.
7409 		 */
7410 		return;
7411 
7412 	if (th_flags & TH_RST) {
7413 		/*
7414 		 * We don't log resets and we return immediately from
7415 		 * sending
7416 		 */
7417 		return;
7418 	}
7419 	rack = (struct tcp_rack *)tp->t_fb_ptr;
7420 	snd_una = tp->snd_una;
7421 	snd_max = tp->snd_max;
7422 	if (th_flags & (TH_SYN | TH_FIN)) {
7423 		/*
7424 		 * The call to rack_log_output is made before bumping
7425 		 * snd_max. This means we can record one extra byte on a SYN
7426 		 * or FIN if seq_out is adding more on and a FIN is present
7427 		 * (and we are not resending).
7428 		 */
7429 		if ((th_flags & TH_SYN) && (seq_out == tp->iss))
7430 			len++;
7431 		if (th_flags & TH_FIN)
7432 			len++;
7433 		if (SEQ_LT(snd_max, tp->snd_nxt)) {
7434 			/*
7435 			 * The add/update as not been done for the FIN/SYN
7436 			 * yet.
7437 			 */
7438 			snd_max = tp->snd_nxt;
7439 		}
7440 	}
7441 	if (SEQ_LEQ((seq_out + len), snd_una)) {
7442 		/* Are sending an old segment to induce an ack (keep-alive)? */
7443 		return;
7444 	}
7445 	if (SEQ_LT(seq_out, snd_una)) {
7446 		/* huh? should we panic? */
7447 		uint32_t end;
7448 
7449 		end = seq_out + len;
7450 		seq_out = snd_una;
7451 		if (SEQ_GEQ(end, seq_out))
7452 			len = end - seq_out;
7453 		else
7454 			len = 0;
7455 	}
7456 	if (len == 0) {
7457 		/* We don't log zero window probes */
7458 		return;
7459 	}
7460 	rack->r_ctl.rc_time_last_sent = cts;
7461 	if (IN_FASTRECOVERY(tp->t_flags)) {
7462 		rack->r_ctl.rc_prr_out += len;
7463 	}
7464 	/* First question is it a retransmission or new? */
7465 	if (seq_out == snd_max) {
7466 		/* Its new */
7467 again:
7468 		rsm = rack_alloc(rack);
7469 		if (rsm == NULL) {
7470 			/*
7471 			 * Hmm out of memory and the tcb got destroyed while
7472 			 * we tried to wait.
7473 			 */
7474 			return;
7475 		}
7476 		if (th_flags & TH_FIN) {
7477 			rsm->r_flags = RACK_HAS_FIN|add_flag;
7478 		} else {
7479 			rsm->r_flags = add_flag;
7480 		}
7481 		if (hw_tls)
7482 			rsm->r_hw_tls = 1;
7483 		rsm->r_tim_lastsent[0] = cts;
7484 		rsm->r_rtr_cnt = 1;
7485 		rsm->r_rtr_bytes = 0;
7486 		if (th_flags & TH_SYN) {
7487 			/* The data space is one beyond snd_una */
7488 			rsm->r_flags |= RACK_HAS_SYN;
7489 		}
7490 		rsm->r_start = seq_out;
7491 		rsm->r_end = rsm->r_start + len;
7492 		rsm->r_dupack = 0;
7493 		/*
7494 		 * save off the mbuf location that
7495 		 * sndmbuf_noadv returned (which is
7496 		 * where we started copying from)..
7497 		 */
7498 		rsm->m = s_mb;
7499 		rsm->soff = s_moff;
7500 		/*
7501 		 * Here we do add in the len of send, since its not yet
7502 		 * reflected in in snduna <->snd_max
7503 		 */
7504 		rsm->r_fas = (ctf_flight_size(rack->rc_tp,
7505 					      rack->r_ctl.rc_sacked) +
7506 			      (rsm->r_end - rsm->r_start));
7507 		/* rsm->m will be NULL if RACK_HAS_SYN or RACK_HAS_FIN is set */
7508 		if (rsm->m) {
7509 			if (rsm->m->m_len <= rsm->soff) {
7510 				/*
7511 				 * XXXrrs Question, will this happen?
7512 				 *
7513 				 * If sbsndptr is set at the correct place
7514 				 * then s_moff should always be somewhere
7515 				 * within rsm->m. But if the sbsndptr was
7516 				 * off then that won't be true. If it occurs
7517 				 * we need to walkout to the correct location.
7518 				 */
7519 				struct mbuf *lm;
7520 
7521 				lm = rsm->m;
7522 				while (lm->m_len <= rsm->soff) {
7523 					rsm->soff -= lm->m_len;
7524 					lm = lm->m_next;
7525 					KASSERT(lm != NULL, ("%s rack:%p lm goes null orig_off:%u origmb:%p rsm->soff:%u",
7526 							     __func__, rack, s_moff, s_mb, rsm->soff));
7527 				}
7528 				rsm->m = lm;
7529 				counter_u64_add(rack_sbsndptr_wrong, 1);
7530 			} else
7531 				counter_u64_add(rack_sbsndptr_right, 1);
7532 			rsm->orig_m_len = rsm->m->m_len;
7533 		} else
7534 			rsm->orig_m_len = 0;
7535 		rack_log_retran_reason(rack, rsm, __LINE__, 0, 2);
7536 		/* Log a new rsm */
7537 		rack_log_map_chg(tp, rack, NULL, rsm, NULL, MAP_NEW, 0, __LINE__);
7538 		insret = RB_INSERT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm);
7539 #ifdef INVARIANTS
7540 		if (insret != NULL) {
7541 			panic("Insert in rb tree of %p fails ret:%p rack:%p rsm:%p",
7542 			      nrsm, insret, rack, rsm);
7543 		}
7544 #endif
7545 		TAILQ_INSERT_TAIL(&rack->r_ctl.rc_tmap, rsm, r_tnext);
7546 		rsm->r_in_tmap = 1;
7547 		/*
7548 		 * Special case detection, is there just a single
7549 		 * packet outstanding when we are not in recovery?
7550 		 *
7551 		 * If this is true mark it so.
7552 		 */
7553 		if ((IN_FASTRECOVERY(tp->t_flags) == 0) &&
7554 		    (ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked) == ctf_fixed_maxseg(tp))) {
7555 			struct rack_sendmap *prsm;
7556 
7557 			prsm = RB_PREV(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm);
7558 			if (prsm)
7559 				prsm->r_one_out_nr = 1;
7560 		}
7561 		return;
7562 	}
7563 	/*
7564 	 * If we reach here its a retransmission and we need to find it.
7565 	 */
7566 	memset(&fe, 0, sizeof(fe));
7567 more:
7568 	if (hintrsm && (hintrsm->r_start == seq_out)) {
7569 		rsm = hintrsm;
7570 		hintrsm = NULL;
7571 	} else {
7572 		/* No hints sorry */
7573 		rsm = NULL;
7574 	}
7575 	if ((rsm) && (rsm->r_start == seq_out)) {
7576 		seq_out = rack_update_entry(tp, rack, rsm, cts, &len, add_flag);
7577 		if (len == 0) {
7578 			return;
7579 		} else {
7580 			goto more;
7581 		}
7582 	}
7583 	/* Ok it was not the last pointer go through it the hard way. */
7584 refind:
7585 	fe.r_start = seq_out;
7586 	rsm = RB_FIND(rack_rb_tree_head, &rack->r_ctl.rc_mtree, &fe);
7587 	if (rsm) {
7588 		if (rsm->r_start == seq_out) {
7589 			seq_out = rack_update_entry(tp, rack, rsm, cts, &len, add_flag);
7590 			if (len == 0) {
7591 				return;
7592 			} else {
7593 				goto refind;
7594 			}
7595 		}
7596 		if (SEQ_GEQ(seq_out, rsm->r_start) && SEQ_LT(seq_out, rsm->r_end)) {
7597 			/* Transmitted within this piece */
7598 			/*
7599 			 * Ok we must split off the front and then let the
7600 			 * update do the rest
7601 			 */
7602 			nrsm = rack_alloc_full_limit(rack);
7603 			if (nrsm == NULL) {
7604 				rack_update_rsm(tp, rack, rsm, cts, add_flag);
7605 				return;
7606 			}
7607 			/*
7608 			 * copy rsm to nrsm and then trim the front of rsm
7609 			 * to not include this part.
7610 			 */
7611 			rack_clone_rsm(rack, nrsm, rsm, seq_out);
7612 			insret = RB_INSERT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, nrsm);
7613 			rack_log_map_chg(tp, rack, NULL, rsm, nrsm, MAP_SPLIT, 0, __LINE__);
7614 #ifdef INVARIANTS
7615 			if (insret != NULL) {
7616 				panic("Insert in rb tree of %p fails ret:%p rack:%p rsm:%p",
7617 				      nrsm, insret, rack, rsm);
7618 			}
7619 #endif
7620 			if (rsm->r_in_tmap) {
7621 				TAILQ_INSERT_AFTER(&rack->r_ctl.rc_tmap, rsm, nrsm, r_tnext);
7622 				nrsm->r_in_tmap = 1;
7623 			}
7624 			rsm->r_flags &= (~RACK_HAS_FIN);
7625 			seq_out = rack_update_entry(tp, rack, nrsm, cts, &len, add_flag);
7626 			if (len == 0) {
7627 				return;
7628 			} else if (len > 0)
7629 				goto refind;
7630 		}
7631 	}
7632 	/*
7633 	 * Hmm not found in map did they retransmit both old and on into the
7634 	 * new?
7635 	 */
7636 	if (seq_out == tp->snd_max) {
7637 		goto again;
7638 	} else if (SEQ_LT(seq_out, tp->snd_max)) {
7639 #ifdef INVARIANTS
7640 		printf("seq_out:%u len:%d snd_una:%u snd_max:%u -- but rsm not found?\n",
7641 		       seq_out, len, tp->snd_una, tp->snd_max);
7642 		printf("Starting Dump of all rack entries\n");
7643 		RB_FOREACH(rsm, rack_rb_tree_head, &rack->r_ctl.rc_mtree) {
7644 			printf("rsm:%p start:%u end:%u\n",
7645 			       rsm, rsm->r_start, rsm->r_end);
7646 		}
7647 		printf("Dump complete\n");
7648 		panic("seq_out not found rack:%p tp:%p",
7649 		      rack, tp);
7650 #endif
7651 	} else {
7652 #ifdef INVARIANTS
7653 		/*
7654 		 * Hmm beyond sndmax? (only if we are using the new rtt-pack
7655 		 * flag)
7656 		 */
7657 		panic("seq_out:%u(%d) is beyond snd_max:%u tp:%p",
7658 		      seq_out, len, tp->snd_max, tp);
7659 #endif
7660 	}
7661 }
7662 
7663 /*
7664  * Record one of the RTT updates from an ack into
7665  * our sample structure.
7666  */
7667 
7668 static void
7669 tcp_rack_xmit_timer(struct tcp_rack *rack, int32_t rtt, uint32_t len, uint32_t us_rtt,
7670 		    int confidence, struct rack_sendmap *rsm, uint16_t rtrcnt)
7671 {
7672 	if ((rack->r_ctl.rack_rs.rs_flags & RACK_RTT_EMPTY) ||
7673 	    (rack->r_ctl.rack_rs.rs_rtt_lowest > rtt)) {
7674 		rack->r_ctl.rack_rs.rs_rtt_lowest = rtt;
7675 	}
7676 	if ((rack->r_ctl.rack_rs.rs_flags & RACK_RTT_EMPTY) ||
7677 	    (rack->r_ctl.rack_rs.rs_rtt_highest < rtt)) {
7678 		rack->r_ctl.rack_rs.rs_rtt_highest = rtt;
7679 	}
7680 	if (rack->rc_tp->t_flags & TF_GPUTINPROG) {
7681 	    if (us_rtt < rack->r_ctl.rc_gp_lowrtt)
7682 		rack->r_ctl.rc_gp_lowrtt = us_rtt;
7683 	    if (rack->rc_tp->snd_wnd > rack->r_ctl.rc_gp_high_rwnd)
7684 		    rack->r_ctl.rc_gp_high_rwnd = rack->rc_tp->snd_wnd;
7685 	}
7686 	if ((confidence == 1) &&
7687 	    ((rsm == NULL) ||
7688 	     (rsm->r_just_ret) ||
7689 	     (rsm->r_one_out_nr &&
7690 	      len < (ctf_fixed_maxseg(rack->rc_tp) * 2)))) {
7691 		/*
7692 		 * If the rsm had a just return
7693 		 * hit it then we can't trust the
7694 		 * rtt measurement for buffer deterimination
7695 		 * Note that a confidence of 2, indicates
7696 		 * SACK'd which overrides the r_just_ret or
7697 		 * the r_one_out_nr. If it was a CUM-ACK and
7698 		 * we had only two outstanding, but get an
7699 		 * ack for only 1. Then that also lowers our
7700 		 * confidence.
7701 		 */
7702 		confidence = 0;
7703 	}
7704 	if ((rack->r_ctl.rack_rs.rs_flags & RACK_RTT_EMPTY) ||
7705 	    (rack->r_ctl.rack_rs.rs_us_rtt > us_rtt)) {
7706 		if (rack->r_ctl.rack_rs.confidence == 0) {
7707 			/*
7708 			 * We take anything with no current confidence
7709 			 * saved.
7710 			 */
7711 			rack->r_ctl.rack_rs.rs_us_rtt = us_rtt;
7712 			rack->r_ctl.rack_rs.confidence = confidence;
7713 			rack->r_ctl.rack_rs.rs_us_rtrcnt = rtrcnt;
7714 		} else if (confidence || rack->r_ctl.rack_rs.confidence) {
7715 			/*
7716 			 * Once we have a confident number,
7717 			 * we can update it with a smaller
7718 			 * value since this confident number
7719 			 * may include the DSACK time until
7720 			 * the next segment (the second one) arrived.
7721 			 */
7722 			rack->r_ctl.rack_rs.rs_us_rtt = us_rtt;
7723 			rack->r_ctl.rack_rs.confidence = confidence;
7724 			rack->r_ctl.rack_rs.rs_us_rtrcnt = rtrcnt;
7725 		}
7726 	}
7727 	rack_log_rtt_upd(rack->rc_tp, rack, us_rtt, len, rsm, confidence);
7728 	rack->r_ctl.rack_rs.rs_flags = RACK_RTT_VALID;
7729 	rack->r_ctl.rack_rs.rs_rtt_tot += rtt;
7730 	rack->r_ctl.rack_rs.rs_rtt_cnt++;
7731 }
7732 
7733 /*
7734  * Collect new round-trip time estimate
7735  * and update averages and current timeout.
7736  */
7737 static void
7738 tcp_rack_xmit_timer_commit(struct tcp_rack *rack, struct tcpcb *tp)
7739 {
7740 	int32_t delta;
7741 	uint32_t o_srtt, o_var;
7742 	int32_t hrtt_up = 0;
7743 	int32_t rtt;
7744 
7745 	if (rack->r_ctl.rack_rs.rs_flags & RACK_RTT_EMPTY)
7746 		/* No valid sample */
7747 		return;
7748 	if (rack->r_ctl.rc_rate_sample_method == USE_RTT_LOW) {
7749 		/* We are to use the lowest RTT seen in a single ack */
7750 		rtt = rack->r_ctl.rack_rs.rs_rtt_lowest;
7751 	} else if (rack->r_ctl.rc_rate_sample_method == USE_RTT_HIGH) {
7752 		/* We are to use the highest RTT seen in a single ack */
7753 		rtt = rack->r_ctl.rack_rs.rs_rtt_highest;
7754 	} else if (rack->r_ctl.rc_rate_sample_method == USE_RTT_AVG) {
7755 		/* We are to use the average RTT seen in a single ack */
7756 		rtt = (int32_t)(rack->r_ctl.rack_rs.rs_rtt_tot /
7757 				(uint64_t)rack->r_ctl.rack_rs.rs_rtt_cnt);
7758 	} else {
7759 #ifdef INVARIANTS
7760 		panic("Unknown rtt variant %d", rack->r_ctl.rc_rate_sample_method);
7761 #endif
7762 		return;
7763 	}
7764 	if (rtt == 0)
7765 		rtt = 1;
7766 	if (rack->rc_gp_rtt_set == 0) {
7767 		/*
7768 		 * With no RTT we have to accept
7769 		 * even one we are not confident of.
7770 		 */
7771 		rack->r_ctl.rc_gp_srtt = rack->r_ctl.rack_rs.rs_us_rtt;
7772 		rack->rc_gp_rtt_set = 1;
7773 	} else if (rack->r_ctl.rack_rs.confidence) {
7774 		/* update the running gp srtt */
7775 		rack->r_ctl.rc_gp_srtt -= (rack->r_ctl.rc_gp_srtt/8);
7776 		rack->r_ctl.rc_gp_srtt += rack->r_ctl.rack_rs.rs_us_rtt / 8;
7777 	}
7778 	if (rack->r_ctl.rack_rs.confidence) {
7779 		/*
7780 		 * record the low and high for highly buffered path computation,
7781 		 * we only do this if we are confident (not a retransmission).
7782 		 */
7783 		if (rack->r_ctl.rc_highest_us_rtt < rack->r_ctl.rack_rs.rs_us_rtt) {
7784 			rack->r_ctl.rc_highest_us_rtt = rack->r_ctl.rack_rs.rs_us_rtt;
7785 			hrtt_up = 1;
7786 		}
7787 		if (rack->rc_highly_buffered == 0) {
7788 			/*
7789 			 * Currently once we declare a path has
7790 			 * highly buffered there is no going
7791 			 * back, which may be a problem...
7792 			 */
7793 			if ((rack->r_ctl.rc_highest_us_rtt / rack->r_ctl.rc_lowest_us_rtt) > rack_hbp_thresh) {
7794 				rack_log_rtt_shrinks(rack, rack->r_ctl.rack_rs.rs_us_rtt,
7795 						     rack->r_ctl.rc_highest_us_rtt,
7796 						     rack->r_ctl.rc_lowest_us_rtt,
7797 						     RACK_RTTS_SEEHBP);
7798 				rack->rc_highly_buffered = 1;
7799 			}
7800 		}
7801 	}
7802 	if ((rack->r_ctl.rack_rs.confidence) ||
7803 	    (rack->r_ctl.rack_rs.rs_us_rtrcnt == 1)) {
7804 		/*
7805 		 * If we are highly confident of it <or> it was
7806 		 * never retransmitted we accept it as the last us_rtt.
7807 		 */
7808 		rack->r_ctl.rc_last_us_rtt = rack->r_ctl.rack_rs.rs_us_rtt;
7809 		/* The lowest rtt can be set if its was not retransmited */
7810 		if (rack->r_ctl.rc_lowest_us_rtt > rack->r_ctl.rack_rs.rs_us_rtt) {
7811 			rack->r_ctl.rc_lowest_us_rtt = rack->r_ctl.rack_rs.rs_us_rtt;
7812 			if (rack->r_ctl.rc_lowest_us_rtt == 0)
7813 				rack->r_ctl.rc_lowest_us_rtt = 1;
7814 		}
7815 	}
7816 	o_srtt = tp->t_srtt;
7817 	o_var = tp->t_rttvar;
7818 	rack = (struct tcp_rack *)tp->t_fb_ptr;
7819 	if (tp->t_srtt != 0) {
7820 		/*
7821 		 * We keep a simple srtt in microseconds, like our rtt
7822 		 * measurement. We don't need to do any tricks with shifting
7823 		 * etc. Instead we just add in 1/8th of the new measurement
7824 		 * and subtract out 1/8 of the old srtt. We do the same with
7825 		 * the variance after finding the absolute value of the
7826 		 * difference between this sample and the current srtt.
7827 		 */
7828 		delta = tp->t_srtt - rtt;
7829 		/* Take off 1/8th of the current sRTT */
7830 		tp->t_srtt -= (tp->t_srtt >> 3);
7831 		/* Add in 1/8th of the new RTT just measured */
7832 		tp->t_srtt += (rtt >> 3);
7833 		if (tp->t_srtt <= 0)
7834 			tp->t_srtt = 1;
7835 		/* Now lets make the absolute value of the variance */
7836 		if (delta < 0)
7837 			delta = -delta;
7838 		/* Subtract out 1/8th */
7839 		tp->t_rttvar -= (tp->t_rttvar >> 3);
7840 		/* Add in 1/8th of the new variance we just saw */
7841 		tp->t_rttvar += (delta >> 3);
7842 		if (tp->t_rttvar <= 0)
7843 			tp->t_rttvar = 1;
7844 		if (tp->t_rttbest > tp->t_srtt + tp->t_rttvar)
7845 			tp->t_rttbest = tp->t_srtt + tp->t_rttvar;
7846 	} else {
7847 		/*
7848 		 * No rtt measurement yet - use the unsmoothed rtt. Set the
7849 		 * variance to half the rtt (so our first retransmit happens
7850 		 * at 3*rtt).
7851 		 */
7852 		tp->t_srtt = rtt;
7853 		tp->t_rttvar = rtt >> 1;
7854 		tp->t_rttbest = tp->t_srtt + tp->t_rttvar;
7855 	}
7856 	rack->rc_srtt_measure_made = 1;
7857 	KMOD_TCPSTAT_INC(tcps_rttupdated);
7858 	tp->t_rttupdated++;
7859 #ifdef STATS
7860 	if (rack_stats_gets_ms_rtt == 0) {
7861 		/* Send in the microsecond rtt used for rxt timeout purposes */
7862 		stats_voi_update_abs_u32(tp->t_stats, VOI_TCP_RTT, imax(0, rtt));
7863 	} else if (rack_stats_gets_ms_rtt == 1) {
7864 		/* Send in the millisecond rtt used for rxt timeout purposes */
7865 		int32_t ms_rtt;
7866 
7867 		/* Round up */
7868 		ms_rtt = (rtt + HPTS_USEC_IN_MSEC - 1) / HPTS_USEC_IN_MSEC;
7869 		stats_voi_update_abs_u32(tp->t_stats, VOI_TCP_RTT, imax(0, ms_rtt));
7870 	} else if (rack_stats_gets_ms_rtt == 2) {
7871 		/* Send in the millisecond rtt has close to the path RTT as we can get  */
7872 		int32_t ms_rtt;
7873 
7874 		/* Round up */
7875 		ms_rtt = (rack->r_ctl.rack_rs.rs_us_rtt + HPTS_USEC_IN_MSEC - 1) / HPTS_USEC_IN_MSEC;
7876 		stats_voi_update_abs_u32(tp->t_stats, VOI_TCP_RTT, imax(0, ms_rtt));
7877 	}  else {
7878 		/* Send in the microsecond rtt has close to the path RTT as we can get  */
7879 		stats_voi_update_abs_u32(tp->t_stats, VOI_TCP_RTT, imax(0, rack->r_ctl.rack_rs.rs_us_rtt));
7880 	}
7881 
7882 #endif
7883 	/*
7884 	 * the retransmit should happen at rtt + 4 * rttvar. Because of the
7885 	 * way we do the smoothing, srtt and rttvar will each average +1/2
7886 	 * tick of bias.  When we compute the retransmit timer, we want 1/2
7887 	 * tick of rounding and 1 extra tick because of +-1/2 tick
7888 	 * uncertainty in the firing of the timer.  The bias will give us
7889 	 * exactly the 1.5 tick we need.  But, because the bias is
7890 	 * statistical, we have to test that we don't drop below the minimum
7891 	 * feasible timer (which is 2 ticks).
7892 	 */
7893 	tp->t_rxtshift = 0;
7894 	RACK_TCPT_RANGESET(tp->t_rxtcur, RACK_REXMTVAL(tp),
7895 		      max(rack_rto_min, rtt + 2), rack_rto_max, rack->r_ctl.timer_slop);
7896 	rack_log_rtt_sample(rack, rtt);
7897 	tp->t_softerror = 0;
7898 }
7899 
7900 
7901 static void
7902 rack_apply_updated_usrtt(struct tcp_rack *rack, uint32_t us_rtt, uint32_t us_cts)
7903 {
7904 	/*
7905 	 * Apply to filter the inbound us-rtt at us_cts.
7906 	 */
7907 	uint32_t old_rtt;
7908 
7909 	old_rtt = get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt);
7910 	apply_filter_min_small(&rack->r_ctl.rc_gp_min_rtt,
7911 			       us_rtt, us_cts);
7912 	if (rack->r_ctl.last_pacing_time &&
7913 	    rack->rc_gp_dyn_mul &&
7914 	    (rack->r_ctl.last_pacing_time > us_rtt))
7915 		rack->pacing_longer_than_rtt = 1;
7916 	else
7917 		rack->pacing_longer_than_rtt = 0;
7918 	if (old_rtt > us_rtt) {
7919 		/* We just hit a new lower rtt time */
7920 		rack_log_rtt_shrinks(rack,  us_cts,  old_rtt,
7921 				     __LINE__, RACK_RTTS_NEWRTT);
7922 		/*
7923 		 * Only count it if its lower than what we saw within our
7924 		 * calculated range.
7925 		 */
7926 		if ((old_rtt - us_rtt) > rack_min_rtt_movement) {
7927 			if (rack_probertt_lower_within &&
7928 			    rack->rc_gp_dyn_mul &&
7929 			    (rack->use_fixed_rate == 0) &&
7930 			    (rack->rc_always_pace)) {
7931 				/*
7932 				 * We are seeing a new lower rtt very close
7933 				 * to the time that we would have entered probe-rtt.
7934 				 * This is probably due to the fact that a peer flow
7935 				 * has entered probe-rtt. Lets go in now too.
7936 				 */
7937 				uint32_t val;
7938 
7939 				val = rack_probertt_lower_within * rack_time_between_probertt;
7940 				val /= 100;
7941 				if ((rack->in_probe_rtt == 0)  &&
7942 				    ((us_cts - rack->r_ctl.rc_lower_rtt_us_cts) >= (rack_time_between_probertt - val)))	{
7943 					rack_enter_probertt(rack, us_cts);
7944 				}
7945 			}
7946 			rack->r_ctl.rc_lower_rtt_us_cts = us_cts;
7947 		}
7948 	}
7949 }
7950 
7951 static int
7952 rack_update_rtt(struct tcpcb *tp, struct tcp_rack *rack,
7953     struct rack_sendmap *rsm, struct tcpopt *to, uint32_t cts, int32_t ack_type, tcp_seq th_ack)
7954 {
7955 	uint32_t us_rtt;
7956 	int32_t i, all;
7957 	uint32_t t, len_acked;
7958 
7959 	if ((rsm->r_flags & RACK_ACKED) ||
7960 	    (rsm->r_flags & RACK_WAS_ACKED))
7961 		/* Already done */
7962 		return (0);
7963 	if (rsm->r_no_rtt_allowed) {
7964 		/* Not allowed */
7965 		return (0);
7966 	}
7967 	if (ack_type == CUM_ACKED) {
7968 		if (SEQ_GT(th_ack, rsm->r_end)) {
7969 			len_acked = rsm->r_end - rsm->r_start;
7970 			all = 1;
7971 		} else {
7972 			len_acked = th_ack - rsm->r_start;
7973 			all = 0;
7974 		}
7975 	} else {
7976 		len_acked = rsm->r_end - rsm->r_start;
7977 		all = 0;
7978 	}
7979 	if (rsm->r_rtr_cnt == 1) {
7980 
7981 		t = cts - (uint32_t)rsm->r_tim_lastsent[(rsm->r_rtr_cnt - 1)];
7982 		if ((int)t <= 0)
7983 			t = 1;
7984 		if (!tp->t_rttlow || tp->t_rttlow > t)
7985 			tp->t_rttlow = t;
7986 		if (!rack->r_ctl.rc_rack_min_rtt ||
7987 		    SEQ_LT(t, rack->r_ctl.rc_rack_min_rtt)) {
7988 			rack->r_ctl.rc_rack_min_rtt = t;
7989 			if (rack->r_ctl.rc_rack_min_rtt == 0) {
7990 				rack->r_ctl.rc_rack_min_rtt = 1;
7991 			}
7992 		}
7993 		if (TSTMP_GT(tcp_tv_to_usectick(&rack->r_ctl.act_rcv_time), rsm->r_tim_lastsent[(rsm->r_rtr_cnt-1)]))
7994 			us_rtt = tcp_tv_to_usectick(&rack->r_ctl.act_rcv_time) - (uint32_t)rsm->r_tim_lastsent[(rsm->r_rtr_cnt-1)];
7995 		else
7996 			us_rtt = tcp_get_usecs(NULL) - (uint32_t)rsm->r_tim_lastsent[(rsm->r_rtr_cnt-1)];
7997 		if (us_rtt == 0)
7998 			us_rtt = 1;
7999 		if (CC_ALGO(tp)->rttsample != NULL) {
8000 			/* Kick the RTT to the CC */
8001 			CC_ALGO(tp)->rttsample(tp->ccv, us_rtt, 1, rsm->r_fas);
8002 		}
8003 		rack_apply_updated_usrtt(rack, us_rtt, tcp_tv_to_usectick(&rack->r_ctl.act_rcv_time));
8004 		if (ack_type == SACKED) {
8005 			rack_log_rtt_sample_calc(rack, t, (uint32_t)rsm->r_tim_lastsent[(rsm->r_rtr_cnt - 1)], cts, 1);
8006 			tcp_rack_xmit_timer(rack, t + 1, len_acked, us_rtt, 2 , rsm, rsm->r_rtr_cnt);
8007 		} else {
8008 			/*
8009 			 * We need to setup what our confidence
8010 			 * is in this ack.
8011 			 *
8012 			 * If the rsm was app limited and it is
8013 			 * less than a mss in length (the end
8014 			 * of the send) then we have a gap. If we
8015 			 * were app limited but say we were sending
8016 			 * multiple MSS's then we are more confident
8017 			 * int it.
8018 			 *
8019 			 * When we are not app-limited then we see if
8020 			 * the rsm is being included in the current
8021 			 * measurement, we tell this by the app_limited_needs_set
8022 			 * flag.
8023 			 *
8024 			 * Note that being cwnd blocked is not applimited
8025 			 * as well as the pacing delay between packets which
8026 			 * are sending only 1 or 2 MSS's also will show up
8027 			 * in the RTT. We probably need to examine this algorithm
8028 			 * a bit more and enhance it to account for the delay
8029 			 * between rsm's. We could do that by saving off the
8030 			 * pacing delay of each rsm (in an rsm) and then
8031 			 * factoring that in somehow though for now I am
8032 			 * not sure how :)
8033 			 */
8034 			int calc_conf = 0;
8035 
8036 			if (rsm->r_flags & RACK_APP_LIMITED) {
8037 				if (all && (len_acked <= ctf_fixed_maxseg(tp)))
8038 					calc_conf = 0;
8039 				else
8040 					calc_conf = 1;
8041 			} else if (rack->app_limited_needs_set == 0) {
8042 				calc_conf = 1;
8043 			} else {
8044 				calc_conf = 0;
8045 			}
8046 			rack_log_rtt_sample_calc(rack, t, (uint32_t)rsm->r_tim_lastsent[(rsm->r_rtr_cnt - 1)], cts, 2);
8047 			tcp_rack_xmit_timer(rack, t + 1, len_acked, us_rtt,
8048 					    calc_conf, rsm, rsm->r_rtr_cnt);
8049 		}
8050 		if ((rsm->r_flags & RACK_TLP) &&
8051 		    (!IN_FASTRECOVERY(tp->t_flags))) {
8052 			/* Segment was a TLP and our retrans matched */
8053 			if (rack->r_ctl.rc_tlp_cwnd_reduce) {
8054 				rack->r_ctl.rc_rsm_start = tp->snd_max;
8055 				rack->r_ctl.rc_cwnd_at = tp->snd_cwnd;
8056 				rack->r_ctl.rc_ssthresh_at = tp->snd_ssthresh;
8057 				rack_cong_signal(tp, CC_NDUPACK, tp->snd_una);
8058 			}
8059 		}
8060 		if (SEQ_LT(rack->r_ctl.rc_rack_tmit_time, (uint32_t)rsm->r_tim_lastsent[(rsm->r_rtr_cnt - 1)])) {
8061 			/* New more recent rack_tmit_time */
8062 			rack->r_ctl.rc_rack_tmit_time = (uint32_t)rsm->r_tim_lastsent[(rsm->r_rtr_cnt - 1)];
8063 			rack->rc_rack_rtt = t;
8064 		}
8065 		return (1);
8066 	}
8067 	/*
8068 	 * We clear the soft/rxtshift since we got an ack.
8069 	 * There is no assurance we will call the commit() function
8070 	 * so we need to clear these to avoid incorrect handling.
8071 	 */
8072 	tp->t_rxtshift = 0;
8073 	RACK_TCPT_RANGESET(tp->t_rxtcur, RACK_REXMTVAL(tp),
8074 		      rack_rto_min, rack_rto_max, rack->r_ctl.timer_slop);
8075 	tp->t_softerror = 0;
8076 	if (to && (to->to_flags & TOF_TS) &&
8077 	    (ack_type == CUM_ACKED) &&
8078 	    (to->to_tsecr) &&
8079 	    ((rsm->r_flags & RACK_OVERMAX) == 0)) {
8080 		/*
8081 		 * Now which timestamp does it match? In this block the ACK
8082 		 * must be coming from a previous transmission.
8083 		 */
8084 		for (i = 0; i < rsm->r_rtr_cnt; i++) {
8085 			if (rack_ts_to_msec(rsm->r_tim_lastsent[i]) == to->to_tsecr) {
8086 				t = cts - (uint32_t)rsm->r_tim_lastsent[i];
8087 				if ((int)t <= 0)
8088 					t = 1;
8089 				if (CC_ALGO(tp)->rttsample != NULL) {
8090 					/*
8091 					 * Kick the RTT to the CC, here
8092 					 * we lie a bit in that we know the
8093 					 * retransmission is correct even though
8094 					 * we retransmitted. This is because
8095 					 * we match the timestamps.
8096 					 */
8097 					if (TSTMP_GT(tcp_tv_to_usectick(&rack->r_ctl.act_rcv_time), rsm->r_tim_lastsent[i]))
8098 						us_rtt = tcp_tv_to_usectick(&rack->r_ctl.act_rcv_time) - (uint32_t)rsm->r_tim_lastsent[i];
8099 					else
8100 						us_rtt = tcp_get_usecs(NULL) - (uint32_t)rsm->r_tim_lastsent[i];
8101 					CC_ALGO(tp)->rttsample(tp->ccv, us_rtt, 1, rsm->r_fas);
8102 				}
8103 				if ((i + 1) < rsm->r_rtr_cnt) {
8104 					/*
8105 					 * The peer ack'd from our previous
8106 					 * transmission. We have a spurious
8107 					 * retransmission and thus we dont
8108 					 * want to update our rack_rtt.
8109 					 *
8110 					 * Hmm should there be a CC revert here?
8111 					 *
8112 					 */
8113 					return (0);
8114 				}
8115 				if (!tp->t_rttlow || tp->t_rttlow > t)
8116 					tp->t_rttlow = t;
8117 				if (!rack->r_ctl.rc_rack_min_rtt || SEQ_LT(t, rack->r_ctl.rc_rack_min_rtt)) {
8118 					rack->r_ctl.rc_rack_min_rtt = t;
8119 					if (rack->r_ctl.rc_rack_min_rtt == 0) {
8120 						rack->r_ctl.rc_rack_min_rtt = 1;
8121 					}
8122 				}
8123 				if (SEQ_LT(rack->r_ctl.rc_rack_tmit_time,
8124 					   (uint32_t)rsm->r_tim_lastsent[(rsm->r_rtr_cnt - 1)])) {
8125 					/* New more recent rack_tmit_time */
8126 					rack->r_ctl.rc_rack_tmit_time = (uint32_t)rsm->r_tim_lastsent[(rsm->r_rtr_cnt - 1)];
8127 					rack->rc_rack_rtt = t;
8128 				}
8129 				rack_log_rtt_sample_calc(rack, t, (uint32_t)rsm->r_tim_lastsent[i], cts, 3);
8130 				tcp_rack_xmit_timer(rack, t + 1, len_acked, t, 0, rsm,
8131 						    rsm->r_rtr_cnt);
8132 				return (1);
8133 			}
8134 		}
8135 		goto ts_not_found;
8136 	} else {
8137 		/*
8138 		 * Ok its a SACK block that we retransmitted. or a windows
8139 		 * machine without timestamps. We can tell nothing from the
8140 		 * time-stamp since its not there or the time the peer last
8141 		 * recieved a segment that moved forward its cum-ack point.
8142 		 */
8143 ts_not_found:
8144 		i = rsm->r_rtr_cnt - 1;
8145 		t = cts - (uint32_t)rsm->r_tim_lastsent[i];
8146 		if ((int)t <= 0)
8147 			t = 1;
8148 		if (rack->r_ctl.rc_rack_min_rtt && SEQ_LT(t, rack->r_ctl.rc_rack_min_rtt)) {
8149 			/*
8150 			 * We retransmitted and the ack came back in less
8151 			 * than the smallest rtt we have observed. We most
8152 			 * likely did an improper retransmit as outlined in
8153 			 * 6.2 Step 2 point 2 in the rack-draft so we
8154 			 * don't want to update our rack_rtt. We in
8155 			 * theory (in future) might want to think about reverting our
8156 			 * cwnd state but we won't for now.
8157 			 */
8158 			return (0);
8159 		} else if (rack->r_ctl.rc_rack_min_rtt) {
8160 			/*
8161 			 * We retransmitted it and the retransmit did the
8162 			 * job.
8163 			 */
8164 			if (!rack->r_ctl.rc_rack_min_rtt ||
8165 			    SEQ_LT(t, rack->r_ctl.rc_rack_min_rtt)) {
8166 				rack->r_ctl.rc_rack_min_rtt = t;
8167 				if (rack->r_ctl.rc_rack_min_rtt == 0) {
8168 					rack->r_ctl.rc_rack_min_rtt = 1;
8169 				}
8170 			}
8171 			if (SEQ_LT(rack->r_ctl.rc_rack_tmit_time, (uint32_t)rsm->r_tim_lastsent[i])) {
8172 				/* New more recent rack_tmit_time */
8173 				rack->r_ctl.rc_rack_tmit_time = (uint32_t)rsm->r_tim_lastsent[i];
8174 				rack->rc_rack_rtt = t;
8175 			}
8176 			return (1);
8177 		}
8178 	}
8179 	return (0);
8180 }
8181 
8182 /*
8183  * Mark the SACK_PASSED flag on all entries prior to rsm send wise.
8184  */
8185 static void
8186 rack_log_sack_passed(struct tcpcb *tp,
8187     struct tcp_rack *rack, struct rack_sendmap *rsm)
8188 {
8189 	struct rack_sendmap *nrsm;
8190 
8191 	nrsm = rsm;
8192 	TAILQ_FOREACH_REVERSE_FROM(nrsm, &rack->r_ctl.rc_tmap,
8193 	    rack_head, r_tnext) {
8194 		if (nrsm == rsm) {
8195 			/* Skip orginal segment he is acked */
8196 			continue;
8197 		}
8198 		if (nrsm->r_flags & RACK_ACKED) {
8199 			/*
8200 			 * Skip ack'd segments, though we
8201 			 * should not see these, since tmap
8202 			 * should not have ack'd segments.
8203 			 */
8204 			continue;
8205 		}
8206 		if (nrsm->r_flags & RACK_SACK_PASSED) {
8207 			/*
8208 			 * We found one that is already marked
8209 			 * passed, we have been here before and
8210 			 * so all others below this are marked.
8211 			 */
8212 			break;
8213 		}
8214 		nrsm->r_flags |= RACK_SACK_PASSED;
8215 		nrsm->r_flags &= ~RACK_WAS_SACKPASS;
8216 	}
8217 }
8218 
8219 static void
8220 rack_need_set_test(struct tcpcb *tp,
8221 		   struct tcp_rack *rack,
8222 		   struct rack_sendmap *rsm,
8223 		   tcp_seq th_ack,
8224 		   int line,
8225 		   int use_which)
8226 {
8227 
8228 	if ((tp->t_flags & TF_GPUTINPROG) &&
8229 	    SEQ_GEQ(rsm->r_end, tp->gput_seq)) {
8230 		/*
8231 		 * We were app limited, and this ack
8232 		 * butts up or goes beyond the point where we want
8233 		 * to start our next measurement. We need
8234 		 * to record the new gput_ts as here and
8235 		 * possibly update the start sequence.
8236 		 */
8237 		uint32_t seq, ts;
8238 
8239 		if (rsm->r_rtr_cnt > 1) {
8240 			/*
8241 			 * This is a retransmit, can we
8242 			 * really make any assessment at this
8243 			 * point?  We are not really sure of
8244 			 * the timestamp, is it this or the
8245 			 * previous transmission?
8246 			 *
8247 			 * Lets wait for something better that
8248 			 * is not retransmitted.
8249 			 */
8250 			return;
8251 		}
8252 		seq = tp->gput_seq;
8253 		ts = tp->gput_ts;
8254 		rack->app_limited_needs_set = 0;
8255 		tp->gput_ts = tcp_tv_to_usectick(&rack->r_ctl.act_rcv_time);
8256 		/* Do we start at a new end? */
8257 		if ((use_which == RACK_USE_BEG) &&
8258 		    SEQ_GEQ(rsm->r_start, tp->gput_seq)) {
8259 			/*
8260 			 * When we get an ACK that just eats
8261 			 * up some of the rsm, we set RACK_USE_BEG
8262 			 * since whats at r_start (i.e. th_ack)
8263 			 * is left unacked and thats where the
8264 			 * measurement not starts.
8265 			 */
8266 			tp->gput_seq = rsm->r_start;
8267 			rack->r_ctl.rc_gp_output_ts = rsm->r_tim_lastsent[(rsm->r_rtr_cnt-1)];
8268 		}
8269 		if ((use_which == RACK_USE_END) &&
8270 		    SEQ_GEQ(rsm->r_end, tp->gput_seq)) {
8271 			    /*
8272 			     * We use the end when the cumack
8273 			     * is moving forward and completely
8274 			     * deleting the rsm passed so basically
8275 			     * r_end holds th_ack.
8276 			     *
8277 			     * For SACK's we also want to use the end
8278 			     * since this piece just got sacked and
8279 			     * we want to target anything after that
8280 			     * in our measurement.
8281 			     */
8282 			    tp->gput_seq = rsm->r_end;
8283 			    rack->r_ctl.rc_gp_output_ts = rsm->r_tim_lastsent[(rsm->r_rtr_cnt-1)];
8284 		}
8285 		if (use_which == RACK_USE_END_OR_THACK) {
8286 			/*
8287 			 * special case for ack moving forward,
8288 			 * not a sack, we need to move all the
8289 			 * way up to where this ack cum-ack moves
8290 			 * to.
8291 			 */
8292 			if (SEQ_GT(th_ack, rsm->r_end))
8293 				tp->gput_seq = th_ack;
8294 			else
8295 				tp->gput_seq = rsm->r_end;
8296 			rack->r_ctl.rc_gp_output_ts = rsm->r_tim_lastsent[(rsm->r_rtr_cnt-1)];
8297 		}
8298 		if (SEQ_GT(tp->gput_seq, tp->gput_ack)) {
8299 			/*
8300 			 * We moved beyond this guy's range, re-calculate
8301 			 * the new end point.
8302 			 */
8303 			if (rack->rc_gp_filled == 0) {
8304 				tp->gput_ack = tp->gput_seq + max(rc_init_window(rack), (MIN_GP_WIN * ctf_fixed_maxseg(tp)));
8305 			} else {
8306 				tp->gput_ack = tp->gput_seq + rack_get_measure_window(tp, rack);
8307 			}
8308 		}
8309 		/*
8310 		 * We are moving the goal post, we may be able to clear the
8311 		 * measure_saw_probe_rtt flag.
8312 		 */
8313 		if ((rack->in_probe_rtt == 0) &&
8314 		    (rack->measure_saw_probe_rtt) &&
8315 		    (SEQ_GEQ(tp->gput_seq, rack->r_ctl.rc_probertt_sndmax_atexit)))
8316 			rack->measure_saw_probe_rtt = 0;
8317 		rack_log_pacing_delay_calc(rack, ts, tp->gput_ts,
8318 					   seq, tp->gput_seq, 0, 5, line, NULL, 0);
8319 		if (rack->rc_gp_filled &&
8320 		    ((tp->gput_ack - tp->gput_seq) <
8321 		     max(rc_init_window(rack), (MIN_GP_WIN *
8322 						ctf_fixed_maxseg(tp))))) {
8323 			uint32_t ideal_amount;
8324 
8325 			ideal_amount = rack_get_measure_window(tp, rack);
8326 			if (ideal_amount > sbavail(&tp->t_inpcb->inp_socket->so_snd)) {
8327 				/*
8328 				 * There is no sense of continuing this measurement
8329 				 * because its too small to gain us anything we
8330 				 * trust. Skip it and that way we can start a new
8331 				 * measurement quicker.
8332 				 */
8333 				tp->t_flags &= ~TF_GPUTINPROG;
8334 				rack_log_pacing_delay_calc(rack, tp->gput_ack, tp->gput_seq,
8335 							   0, 0, 0, 6, __LINE__, NULL, 0);
8336 			} else {
8337 				/*
8338 				 * Reset the window further out.
8339 				 */
8340 				tp->gput_ack = tp->gput_seq + ideal_amount;
8341 			}
8342 		}
8343 	}
8344 }
8345 
8346 static inline int
8347 is_rsm_inside_declared_tlp_block(struct tcp_rack *rack, struct rack_sendmap *rsm)
8348 {
8349 	if (SEQ_LT(rsm->r_end, rack->r_ctl.last_tlp_acked_start)) {
8350 		/* Behind our TLP definition or right at */
8351 		return (0);
8352 	}
8353 	if (SEQ_GT(rsm->r_start, rack->r_ctl.last_tlp_acked_end)) {
8354 		/* The start is beyond or right at our end of TLP definition */
8355 		return (0);
8356 	}
8357 	/* It has to be a sub-part of the original TLP recorded */
8358 	return (1);
8359 }
8360 
8361 
8362 static uint32_t
8363 rack_proc_sack_blk(struct tcpcb *tp, struct tcp_rack *rack, struct sackblk *sack,
8364 		   struct tcpopt *to, struct rack_sendmap **prsm, uint32_t cts, int *moved_two)
8365 {
8366 	uint32_t start, end, changed = 0;
8367 	struct rack_sendmap stack_map;
8368 	struct rack_sendmap *rsm, *nrsm, fe, *insret, *prev, *next;
8369 	int32_t used_ref = 1;
8370 	int moved = 0;
8371 
8372 	start = sack->start;
8373 	end = sack->end;
8374 	rsm = *prsm;
8375 	memset(&fe, 0, sizeof(fe));
8376 do_rest_ofb:
8377 	if ((rsm == NULL) ||
8378 	    (SEQ_LT(end, rsm->r_start)) ||
8379 	    (SEQ_GEQ(start, rsm->r_end)) ||
8380 	    (SEQ_LT(start, rsm->r_start))) {
8381 		/*
8382 		 * We are not in the right spot,
8383 		 * find the correct spot in the tree.
8384 		 */
8385 		used_ref = 0;
8386 		fe.r_start = start;
8387 		rsm = RB_FIND(rack_rb_tree_head, &rack->r_ctl.rc_mtree, &fe);
8388 		moved++;
8389 	}
8390 	if (rsm == NULL) {
8391 		/* TSNH */
8392 		goto out;
8393 	}
8394 	/* Ok we have an ACK for some piece of this rsm */
8395 	if (rsm->r_start != start) {
8396 		if ((rsm->r_flags & RACK_ACKED) == 0) {
8397 			/*
8398 			 * Before any splitting or hookery is
8399 			 * done is it a TLP of interest i.e. rxt?
8400 			 */
8401 			if ((rsm->r_flags & RACK_TLP) &&
8402 			    (rsm->r_rtr_cnt > 1)) {
8403 				/*
8404 				 * We are splitting a rxt TLP, check
8405 				 * if we need to save off the start/end
8406 				 */
8407 				if (rack->rc_last_tlp_acked_set &&
8408 				    (is_rsm_inside_declared_tlp_block(rack, rsm))) {
8409 					/*
8410 					 * We already turned this on since we are inside
8411 					 * the previous one was a partially sack now we
8412 					 * are getting another one (maybe all of it).
8413 					 *
8414 					 */
8415 					rack_log_dsack_event(rack, 10, __LINE__, rsm->r_start, rsm->r_end);
8416 					/*
8417 					 * Lets make sure we have all of it though.
8418 					 */
8419 					if (SEQ_LT(rsm->r_start, rack->r_ctl.last_tlp_acked_start)) {
8420 						rack->r_ctl.last_tlp_acked_start = rsm->r_start;
8421 						rack_log_dsack_event(rack, 11, __LINE__, rack->r_ctl.last_tlp_acked_start,
8422 								     rack->r_ctl.last_tlp_acked_end);
8423 					}
8424 					if (SEQ_GT(rsm->r_end, rack->r_ctl.last_tlp_acked_end)) {
8425 						rack->r_ctl.last_tlp_acked_end = rsm->r_end;
8426 						rack_log_dsack_event(rack, 11, __LINE__, rack->r_ctl.last_tlp_acked_start,
8427 								     rack->r_ctl.last_tlp_acked_end);
8428 					}
8429 				} else {
8430 					rack->r_ctl.last_tlp_acked_start = rsm->r_start;
8431 					rack->r_ctl.last_tlp_acked_end = rsm->r_end;
8432 					rack->rc_last_tlp_past_cumack = 0;
8433 					rack->rc_last_tlp_acked_set = 1;
8434 					rack_log_dsack_event(rack, 8, __LINE__, rsm->r_start, rsm->r_end);
8435 				}
8436 			}
8437 			/**
8438 			 * Need to split this in two pieces the before and after,
8439 			 * the before remains in the map, the after must be
8440 			 * added. In other words we have:
8441 			 * rsm        |--------------|
8442 			 * sackblk        |------->
8443 			 * rsm will become
8444 			 *     rsm    |---|
8445 			 * and nrsm will be  the sacked piece
8446 			 *     nrsm       |----------|
8447 			 *
8448 			 * But before we start down that path lets
8449 			 * see if the sack spans over on top of
8450 			 * the next guy and it is already sacked.
8451 			 *
8452 			 */
8453 			next = RB_NEXT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm);
8454 			if (next && (next->r_flags & RACK_ACKED) &&
8455 			    SEQ_GEQ(end, next->r_start)) {
8456 				/**
8457 				 * So the next one is already acked, and
8458 				 * we can thus by hookery use our stack_map
8459 				 * to reflect the piece being sacked and
8460 				 * then adjust the two tree entries moving
8461 				 * the start and ends around. So we start like:
8462 				 *  rsm     |------------|             (not-acked)
8463 				 *  next                 |-----------| (acked)
8464 				 *  sackblk        |-------->
8465 				 *  We want to end like so:
8466 				 *  rsm     |------|                   (not-acked)
8467 				 *  next           |-----------------| (acked)
8468 				 *  nrsm           |-----|
8469 				 * Where nrsm is a temporary stack piece we
8470 				 * use to update all the gizmos.
8471 				 */
8472 				/* Copy up our fudge block */
8473 				nrsm = &stack_map;
8474 				memcpy(nrsm, rsm, sizeof(struct rack_sendmap));
8475 				/* Now adjust our tree blocks */
8476 				rsm->r_end = start;
8477 				next->r_start = start;
8478 				/* Now we must adjust back where next->m is */
8479 				rack_setup_offset_for_rsm(rsm, next);
8480 
8481 				/* We don't need to adjust rsm, it did not change */
8482 				/* Clear out the dup ack count of the remainder */
8483 				rsm->r_dupack = 0;
8484 				rsm->r_just_ret = 0;
8485 				rack_log_retran_reason(rack, rsm, __LINE__, 0, 2);
8486 				/* Now lets make sure our fudge block is right */
8487 				nrsm->r_start = start;
8488 				/* Now lets update all the stats and such */
8489 				rack_update_rtt(tp, rack, nrsm, to, cts, SACKED, 0);
8490 				if (rack->app_limited_needs_set)
8491 					rack_need_set_test(tp, rack, nrsm, tp->snd_una, __LINE__, RACK_USE_END);
8492 				changed += (nrsm->r_end - nrsm->r_start);
8493 				rack->r_ctl.rc_sacked += (nrsm->r_end - nrsm->r_start);
8494 				if (nrsm->r_flags & RACK_SACK_PASSED) {
8495 					counter_u64_add(rack_reorder_seen, 1);
8496 					rack->r_ctl.rc_reorder_ts = cts;
8497 				}
8498 				/*
8499 				 * Now we want to go up from rsm (the
8500 				 * one left un-acked) to the next one
8501 				 * in the tmap. We do this so when
8502 				 * we walk backwards we include marking
8503 				 * sack-passed on rsm (The one passed in
8504 				 * is skipped since it is generally called
8505 				 * on something sacked before removing it
8506 				 * from the tmap).
8507 				 */
8508 				if (rsm->r_in_tmap) {
8509 					nrsm = TAILQ_NEXT(rsm, r_tnext);
8510 					/*
8511 					 * Now that we have the next
8512 					 * one walk backwards from there.
8513 					 */
8514 					if (nrsm && nrsm->r_in_tmap)
8515 						rack_log_sack_passed(tp, rack, nrsm);
8516 				}
8517 				/* Now are we done? */
8518 				if (SEQ_LT(end, next->r_end) ||
8519 				    (end == next->r_end)) {
8520 					/* Done with block */
8521 					goto out;
8522 				}
8523 				rack_log_map_chg(tp, rack, &stack_map, rsm, next, MAP_SACK_M1, end, __LINE__);
8524 				counter_u64_add(rack_sack_used_next_merge, 1);
8525 				/* Postion for the next block */
8526 				start = next->r_end;
8527 				rsm = RB_NEXT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, next);
8528 				if (rsm == NULL)
8529 					goto out;
8530 			} else {
8531 				/**
8532 				 * We can't use any hookery here, so we
8533 				 * need to split the map. We enter like
8534 				 * so:
8535 				 *  rsm      |--------|
8536 				 *  sackblk       |----->
8537 				 * We will add the new block nrsm and
8538 				 * that will be the new portion, and then
8539 				 * fall through after reseting rsm. So we
8540 				 * split and look like this:
8541 				 *  rsm      |----|
8542 				 *  sackblk       |----->
8543 				 *  nrsm          |---|
8544 				 * We then fall through reseting
8545 				 * rsm to nrsm, so the next block
8546 				 * picks it up.
8547 				 */
8548 				nrsm = rack_alloc_limit(rack, RACK_LIMIT_TYPE_SPLIT);
8549 				if (nrsm == NULL) {
8550 					/*
8551 					 * failed XXXrrs what can we do but loose the sack
8552 					 * info?
8553 					 */
8554 					goto out;
8555 				}
8556 				counter_u64_add(rack_sack_splits, 1);
8557 				rack_clone_rsm(rack, nrsm, rsm, start);
8558 				rsm->r_just_ret = 0;
8559 				insret = RB_INSERT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, nrsm);
8560 #ifdef INVARIANTS
8561 				if (insret != NULL) {
8562 					panic("Insert in rb tree of %p fails ret:%p rack:%p rsm:%p",
8563 					      nrsm, insret, rack, rsm);
8564 				}
8565 #endif
8566 				if (rsm->r_in_tmap) {
8567 					TAILQ_INSERT_AFTER(&rack->r_ctl.rc_tmap, rsm, nrsm, r_tnext);
8568 					nrsm->r_in_tmap = 1;
8569 				}
8570 				rack_log_map_chg(tp, rack, NULL, rsm, nrsm, MAP_SACK_M2, end, __LINE__);
8571 				rsm->r_flags &= (~RACK_HAS_FIN);
8572 				/* Position us to point to the new nrsm that starts the sack blk */
8573 				rsm = nrsm;
8574 			}
8575 		} else {
8576 			/* Already sacked this piece */
8577 			counter_u64_add(rack_sack_skipped_acked, 1);
8578 			moved++;
8579 			if (end == rsm->r_end) {
8580 				/* Done with block */
8581 				rsm = RB_NEXT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm);
8582 				goto out;
8583 			} else if (SEQ_LT(end, rsm->r_end)) {
8584 				/* A partial sack to a already sacked block */
8585 				moved++;
8586 				rsm = RB_NEXT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm);
8587 				goto out;
8588 			} else {
8589 				/*
8590 				 * The end goes beyond this guy
8591 				 * repostion the start to the
8592 				 * next block.
8593 				 */
8594 				start = rsm->r_end;
8595 				rsm = RB_NEXT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm);
8596 				if (rsm == NULL)
8597 					goto out;
8598 			}
8599 		}
8600 	}
8601 	if (SEQ_GEQ(end, rsm->r_end)) {
8602 		/**
8603 		 * The end of this block is either beyond this guy or right
8604 		 * at this guy. I.e.:
8605 		 *  rsm ---                 |-----|
8606 		 *  end                     |-----|
8607 		 *  <or>
8608 		 *  end                     |---------|
8609 		 */
8610 		if ((rsm->r_flags & RACK_ACKED) == 0) {
8611 			/*
8612 			 * Is it a TLP of interest?
8613 			 */
8614 			if ((rsm->r_flags & RACK_TLP) &&
8615 			    (rsm->r_rtr_cnt > 1)) {
8616 				/*
8617 				 * We are splitting a rxt TLP, check
8618 				 * if we need to save off the start/end
8619 				 */
8620 				if (rack->rc_last_tlp_acked_set &&
8621 				    (is_rsm_inside_declared_tlp_block(rack, rsm))) {
8622 					/*
8623 					 * We already turned this on since we are inside
8624 					 * the previous one was a partially sack now we
8625 					 * are getting another one (maybe all of it).
8626 					 */
8627 					rack_log_dsack_event(rack, 10, __LINE__, rsm->r_start, rsm->r_end);
8628 					/*
8629 					 * Lets make sure we have all of it though.
8630 					 */
8631 					if (SEQ_LT(rsm->r_start, rack->r_ctl.last_tlp_acked_start)) {
8632 						rack->r_ctl.last_tlp_acked_start = rsm->r_start;
8633 						rack_log_dsack_event(rack, 11, __LINE__, rack->r_ctl.last_tlp_acked_start,
8634 								     rack->r_ctl.last_tlp_acked_end);
8635 					}
8636 					if (SEQ_GT(rsm->r_end, rack->r_ctl.last_tlp_acked_end)) {
8637 						rack->r_ctl.last_tlp_acked_end = rsm->r_end;
8638 						rack_log_dsack_event(rack, 11, __LINE__, rack->r_ctl.last_tlp_acked_start,
8639 								     rack->r_ctl.last_tlp_acked_end);
8640 					}
8641 				} else {
8642 					rack->r_ctl.last_tlp_acked_start = rsm->r_start;
8643 					rack->r_ctl.last_tlp_acked_end = rsm->r_end;
8644 					rack->rc_last_tlp_past_cumack = 0;
8645 					rack->rc_last_tlp_acked_set = 1;
8646 					rack_log_dsack_event(rack, 8, __LINE__, rsm->r_start, rsm->r_end);
8647 				}
8648 			}
8649 			rack_update_rtt(tp, rack, rsm, to, cts, SACKED, 0);
8650 			changed += (rsm->r_end - rsm->r_start);
8651 			rack->r_ctl.rc_sacked += (rsm->r_end - rsm->r_start);
8652 			if (rsm->r_in_tmap) /* should be true */
8653 				rack_log_sack_passed(tp, rack, rsm);
8654 			/* Is Reordering occuring? */
8655 			if (rsm->r_flags & RACK_SACK_PASSED) {
8656 				rsm->r_flags &= ~RACK_SACK_PASSED;
8657 				counter_u64_add(rack_reorder_seen, 1);
8658 				rack->r_ctl.rc_reorder_ts = cts;
8659 			}
8660 			if (rack->app_limited_needs_set)
8661 				rack_need_set_test(tp, rack, rsm, tp->snd_una, __LINE__, RACK_USE_END);
8662 			rsm->r_ack_arrival = rack_to_usec_ts(&rack->r_ctl.act_rcv_time);
8663 			rsm->r_flags |= RACK_ACKED;
8664 			if (rsm->r_in_tmap) {
8665 				TAILQ_REMOVE(&rack->r_ctl.rc_tmap, rsm, r_tnext);
8666 				rsm->r_in_tmap = 0;
8667 			}
8668 			rack_log_map_chg(tp, rack, NULL, rsm, NULL, MAP_SACK_M3, end, __LINE__);
8669 		} else {
8670 			counter_u64_add(rack_sack_skipped_acked, 1);
8671 			moved++;
8672 		}
8673 		if (end == rsm->r_end) {
8674 			/* This block only - done, setup for next */
8675 			goto out;
8676 		}
8677 		/*
8678 		 * There is more not coverend by this rsm move on
8679 		 * to the next block in the RB tree.
8680 		 */
8681 		nrsm = RB_NEXT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm);
8682 		start = rsm->r_end;
8683 		rsm = nrsm;
8684 		if (rsm == NULL)
8685 			goto out;
8686 		goto do_rest_ofb;
8687 	}
8688 	/**
8689 	 * The end of this sack block is smaller than
8690 	 * our rsm i.e.:
8691 	 *  rsm ---                 |-----|
8692 	 *  end                     |--|
8693 	 */
8694 	if ((rsm->r_flags & RACK_ACKED) == 0) {
8695 		/*
8696 		 * Is it a TLP of interest?
8697 		 */
8698 		if ((rsm->r_flags & RACK_TLP) &&
8699 		    (rsm->r_rtr_cnt > 1)) {
8700 			/*
8701 			 * We are splitting a rxt TLP, check
8702 			 * if we need to save off the start/end
8703 			 */
8704 			if (rack->rc_last_tlp_acked_set &&
8705 			    (is_rsm_inside_declared_tlp_block(rack, rsm))) {
8706 				/*
8707 				 * We already turned this on since we are inside
8708 				 * the previous one was a partially sack now we
8709 				 * are getting another one (maybe all of it).
8710 				 */
8711 				rack_log_dsack_event(rack, 10, __LINE__, rsm->r_start, rsm->r_end);
8712 				/*
8713 				 * Lets make sure we have all of it though.
8714 				 */
8715 				if (SEQ_LT(rsm->r_start, rack->r_ctl.last_tlp_acked_start)) {
8716 					rack->r_ctl.last_tlp_acked_start = rsm->r_start;
8717 					rack_log_dsack_event(rack, 11, __LINE__, rack->r_ctl.last_tlp_acked_start,
8718 							     rack->r_ctl.last_tlp_acked_end);
8719 				}
8720 				if (SEQ_GT(rsm->r_end, rack->r_ctl.last_tlp_acked_end)) {
8721 					rack->r_ctl.last_tlp_acked_end = rsm->r_end;
8722 					rack_log_dsack_event(rack, 11, __LINE__, rack->r_ctl.last_tlp_acked_start,
8723 							     rack->r_ctl.last_tlp_acked_end);
8724 				}
8725 			} else {
8726 				rack->r_ctl.last_tlp_acked_start = rsm->r_start;
8727 				rack->r_ctl.last_tlp_acked_end = rsm->r_end;
8728 				rack->rc_last_tlp_past_cumack = 0;
8729 				rack->rc_last_tlp_acked_set = 1;
8730 				rack_log_dsack_event(rack, 8, __LINE__, rsm->r_start, rsm->r_end);
8731 			}
8732 		}
8733 		prev = RB_PREV(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm);
8734 		if (prev &&
8735 		    (prev->r_flags & RACK_ACKED)) {
8736 			/**
8737 			 * Goal, we want the right remainder of rsm to shrink
8738 			 * in place and span from (rsm->r_start = end) to rsm->r_end.
8739 			 * We want to expand prev to go all the way
8740 			 * to prev->r_end <- end.
8741 			 * so in the tree we have before:
8742 			 *   prev     |--------|         (acked)
8743 			 *   rsm               |-------| (non-acked)
8744 			 *   sackblk           |-|
8745 			 * We churn it so we end up with
8746 			 *   prev     |----------|       (acked)
8747 			 *   rsm                 |-----| (non-acked)
8748 			 *   nrsm              |-| (temporary)
8749 			 *
8750 			 * Note if either prev/rsm is a TLP we don't
8751 			 * do this.
8752 			 */
8753 			nrsm = &stack_map;
8754 			memcpy(nrsm, rsm, sizeof(struct rack_sendmap));
8755 			prev->r_end = end;
8756 			rsm->r_start = end;
8757 			/* Now adjust nrsm (stack copy) to be
8758 			 * the one that is the small
8759 			 * piece that was "sacked".
8760 			 */
8761 			nrsm->r_end = end;
8762 			rsm->r_dupack = 0;
8763 			rack_log_retran_reason(rack, rsm, __LINE__, 0, 2);
8764 			/*
8765 			 * Now that the rsm has had its start moved forward
8766 			 * lets go ahead and get its new place in the world.
8767 			 */
8768 			rack_setup_offset_for_rsm(prev, rsm);
8769 			/*
8770 			 * Now nrsm is our new little piece
8771 			 * that is acked (which was merged
8772 			 * to prev). Update the rtt and changed
8773 			 * based on that. Also check for reordering.
8774 			 */
8775 			rack_update_rtt(tp, rack, nrsm, to, cts, SACKED, 0);
8776 			if (rack->app_limited_needs_set)
8777 				rack_need_set_test(tp, rack, nrsm, tp->snd_una, __LINE__, RACK_USE_END);
8778 			changed += (nrsm->r_end - nrsm->r_start);
8779 			rack->r_ctl.rc_sacked += (nrsm->r_end - nrsm->r_start);
8780 			if (nrsm->r_flags & RACK_SACK_PASSED) {
8781 				counter_u64_add(rack_reorder_seen, 1);
8782 				rack->r_ctl.rc_reorder_ts = cts;
8783 			}
8784 			rack_log_map_chg(tp, rack, prev, &stack_map, rsm, MAP_SACK_M4, end, __LINE__);
8785 			rsm = prev;
8786 			counter_u64_add(rack_sack_used_prev_merge, 1);
8787 		} else {
8788 			/**
8789 			 * This is the case where our previous
8790 			 * block is not acked either, so we must
8791 			 * split the block in two.
8792 			 */
8793 			nrsm = rack_alloc_limit(rack, RACK_LIMIT_TYPE_SPLIT);
8794 			if (nrsm == NULL) {
8795 				/* failed rrs what can we do but loose the sack info? */
8796 				goto out;
8797 			}
8798 			if ((rsm->r_flags & RACK_TLP) &&
8799 			    (rsm->r_rtr_cnt > 1)) {
8800 				/*
8801 				 * We are splitting a rxt TLP, check
8802 				 * if we need to save off the start/end
8803 				 */
8804 				if (rack->rc_last_tlp_acked_set &&
8805 				    (is_rsm_inside_declared_tlp_block(rack, rsm))) {
8806 					    /*
8807 					     * We already turned this on since this block is inside
8808 					     * the previous one was a partially sack now we
8809 					     * are getting another one (maybe all of it).
8810 					     */
8811 					    rack_log_dsack_event(rack, 10, __LINE__, rsm->r_start, rsm->r_end);
8812 					    /*
8813 					     * Lets make sure we have all of it though.
8814 					     */
8815 					    if (SEQ_LT(rsm->r_start, rack->r_ctl.last_tlp_acked_start)) {
8816 						    rack->r_ctl.last_tlp_acked_start = rsm->r_start;
8817 						    rack_log_dsack_event(rack, 11, __LINE__, rack->r_ctl.last_tlp_acked_start,
8818 									 rack->r_ctl.last_tlp_acked_end);
8819 					    }
8820 					    if (SEQ_GT(rsm->r_end, rack->r_ctl.last_tlp_acked_end)) {
8821 						    rack->r_ctl.last_tlp_acked_end = rsm->r_end;
8822 						    rack_log_dsack_event(rack, 11, __LINE__, rack->r_ctl.last_tlp_acked_start,
8823 									 rack->r_ctl.last_tlp_acked_end);
8824 					    }
8825 				    } else {
8826 					    rack->r_ctl.last_tlp_acked_start = rsm->r_start;
8827 					    rack->r_ctl.last_tlp_acked_end = rsm->r_end;
8828 					    rack->rc_last_tlp_acked_set = 1;
8829 					    rack->rc_last_tlp_past_cumack = 0;
8830 					    rack_log_dsack_event(rack, 8, __LINE__, rsm->r_start, rsm->r_end);
8831 				    }
8832 			}
8833 			/**
8834 			 * In this case nrsm becomes
8835 			 * nrsm->r_start = end;
8836 			 * nrsm->r_end = rsm->r_end;
8837 			 * which is un-acked.
8838 			 * <and>
8839 			 * rsm->r_end = nrsm->r_start;
8840 			 * i.e. the remaining un-acked
8841 			 * piece is left on the left
8842 			 * hand side.
8843 			 *
8844 			 * So we start like this
8845 			 * rsm      |----------| (not acked)
8846 			 * sackblk  |---|
8847 			 * build it so we have
8848 			 * rsm      |---|         (acked)
8849 			 * nrsm         |------|  (not acked)
8850 			 */
8851 			counter_u64_add(rack_sack_splits, 1);
8852 			rack_clone_rsm(rack, nrsm, rsm, end);
8853 			rsm->r_flags &= (~RACK_HAS_FIN);
8854 			rsm->r_just_ret = 0;
8855 			insret = RB_INSERT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, nrsm);
8856 #ifdef INVARIANTS
8857 			if (insret != NULL) {
8858 				panic("Insert in rb tree of %p fails ret:%p rack:%p rsm:%p",
8859 				      nrsm, insret, rack, rsm);
8860 			}
8861 #endif
8862 			if (rsm->r_in_tmap) {
8863 				TAILQ_INSERT_AFTER(&rack->r_ctl.rc_tmap, rsm, nrsm, r_tnext);
8864 				nrsm->r_in_tmap = 1;
8865 			}
8866 			nrsm->r_dupack = 0;
8867 			rack_log_retran_reason(rack, nrsm, __LINE__, 0, 2);
8868 			rack_update_rtt(tp, rack, rsm, to, cts, SACKED, 0);
8869 			changed += (rsm->r_end - rsm->r_start);
8870 			rack->r_ctl.rc_sacked += (rsm->r_end - rsm->r_start);
8871 			if (rsm->r_in_tmap) /* should be true */
8872 				rack_log_sack_passed(tp, rack, rsm);
8873 			/* Is Reordering occuring? */
8874 			if (rsm->r_flags & RACK_SACK_PASSED) {
8875 				rsm->r_flags &= ~RACK_SACK_PASSED;
8876 				counter_u64_add(rack_reorder_seen, 1);
8877 				rack->r_ctl.rc_reorder_ts = cts;
8878 			}
8879 			if (rack->app_limited_needs_set)
8880 				rack_need_set_test(tp, rack, rsm, tp->snd_una, __LINE__, RACK_USE_END);
8881 			rsm->r_ack_arrival = rack_to_usec_ts(&rack->r_ctl.act_rcv_time);
8882 			rsm->r_flags |= RACK_ACKED;
8883 			rack_log_map_chg(tp, rack, NULL, rsm, nrsm, MAP_SACK_M5, end, __LINE__);
8884 			if (rsm->r_in_tmap) {
8885 				TAILQ_REMOVE(&rack->r_ctl.rc_tmap, rsm, r_tnext);
8886 				rsm->r_in_tmap = 0;
8887 			}
8888 		}
8889 	} else if (start != end){
8890 		/*
8891 		 * The block was already acked.
8892 		 */
8893 		counter_u64_add(rack_sack_skipped_acked, 1);
8894 		moved++;
8895 	}
8896 out:
8897 	if (rsm &&
8898 	    ((rsm->r_flags & RACK_TLP) == 0) &&
8899 	    (rsm->r_flags & RACK_ACKED)) {
8900 		/*
8901 		 * Now can we merge where we worked
8902 		 * with either the previous or
8903 		 * next block?
8904 		 */
8905 		next = RB_NEXT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm);
8906 		while (next) {
8907 			if (next->r_flags & RACK_TLP)
8908 				break;
8909 			if (next->r_flags & RACK_ACKED) {
8910 			/* yep this and next can be merged */
8911 				rsm = rack_merge_rsm(rack, rsm, next);
8912 				next = RB_NEXT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm);
8913 			} else
8914 				break;
8915 		}
8916 		/* Now what about the previous? */
8917 		prev = RB_PREV(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm);
8918 		while (prev) {
8919 			if (prev->r_flags & RACK_TLP)
8920 				break;
8921 			if (prev->r_flags & RACK_ACKED) {
8922 				/* yep the previous and this can be merged */
8923 				rsm = rack_merge_rsm(rack, prev, rsm);
8924 				prev = RB_PREV(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm);
8925 			} else
8926 				break;
8927 		}
8928 	}
8929 	if (used_ref == 0) {
8930 		counter_u64_add(rack_sack_proc_all, 1);
8931 	} else {
8932 		counter_u64_add(rack_sack_proc_short, 1);
8933 	}
8934 	/* Save off the next one for quick reference. */
8935 	if (rsm)
8936 		nrsm = RB_NEXT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm);
8937 	else
8938 		nrsm = NULL;
8939 	*prsm = rack->r_ctl.rc_sacklast = nrsm;
8940 	/* Pass back the moved. */
8941 	*moved_two = moved;
8942 	return (changed);
8943 }
8944 
8945 static void inline
8946 rack_peer_reneges(struct tcp_rack *rack, struct rack_sendmap *rsm, tcp_seq th_ack)
8947 {
8948 	struct rack_sendmap *tmap;
8949 
8950 	tmap = NULL;
8951 	while (rsm && (rsm->r_flags & RACK_ACKED)) {
8952 		/* Its no longer sacked, mark it so */
8953 		rack->r_ctl.rc_sacked -= (rsm->r_end - rsm->r_start);
8954 #ifdef INVARIANTS
8955 		if (rsm->r_in_tmap) {
8956 			panic("rack:%p rsm:%p flags:0x%x in tmap?",
8957 			      rack, rsm, rsm->r_flags);
8958 		}
8959 #endif
8960 		rsm->r_flags &= ~(RACK_ACKED|RACK_SACK_PASSED|RACK_WAS_SACKPASS);
8961 		/* Rebuild it into our tmap */
8962 		if (tmap == NULL) {
8963 			TAILQ_INSERT_HEAD(&rack->r_ctl.rc_tmap, rsm, r_tnext);
8964 			tmap = rsm;
8965 		} else {
8966 			TAILQ_INSERT_AFTER(&rack->r_ctl.rc_tmap, tmap, rsm, r_tnext);
8967 			tmap = rsm;
8968 		}
8969 		tmap->r_in_tmap = 1;
8970 		rsm = RB_NEXT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm);
8971 	}
8972 	/*
8973 	 * Now lets possibly clear the sack filter so we start
8974 	 * recognizing sacks that cover this area.
8975 	 */
8976 	sack_filter_clear(&rack->r_ctl.rack_sf, th_ack);
8977 
8978 }
8979 
8980 static void
8981 rack_do_decay(struct tcp_rack *rack)
8982 {
8983 	struct timeval res;
8984 
8985 #define	timersub(tvp, uvp, vvp)						\
8986 	do {								\
8987 		(vvp)->tv_sec = (tvp)->tv_sec - (uvp)->tv_sec;		\
8988 		(vvp)->tv_usec = (tvp)->tv_usec - (uvp)->tv_usec;	\
8989 		if ((vvp)->tv_usec < 0) {				\
8990 			(vvp)->tv_sec--;				\
8991 			(vvp)->tv_usec += 1000000;			\
8992 		}							\
8993 	} while (0)
8994 
8995 	timersub(&rack->r_ctl.act_rcv_time, &rack->r_ctl.rc_last_time_decay, &res);
8996 #undef timersub
8997 
8998 	rack->r_ctl.input_pkt++;
8999 	if ((rack->rc_in_persist) ||
9000 	    (res.tv_sec >= 1) ||
9001 	    (rack->rc_tp->snd_max == rack->rc_tp->snd_una)) {
9002 		/*
9003 		 * Check for decay of non-SAD,
9004 		 * we want all SAD detection metrics to
9005 		 * decay 1/4 per second (or more) passed.
9006 		 */
9007 		uint32_t pkt_delta;
9008 
9009 		pkt_delta = rack->r_ctl.input_pkt - rack->r_ctl.saved_input_pkt;
9010 		/* Update our saved tracking values */
9011 		rack->r_ctl.saved_input_pkt = rack->r_ctl.input_pkt;
9012 		rack->r_ctl.rc_last_time_decay = rack->r_ctl.act_rcv_time;
9013 		/* Now do we escape without decay? */
9014 #ifdef NETFLIX_EXP_DETECTION
9015 		if (rack->rc_in_persist ||
9016 		    (rack->rc_tp->snd_max == rack->rc_tp->snd_una) ||
9017 		    (pkt_delta < tcp_sad_low_pps)){
9018 			/*
9019 			 * We don't decay idle connections
9020 			 * or ones that have a low input pps.
9021 			 */
9022 			return;
9023 		}
9024 		/* Decay the counters */
9025 		rack->r_ctl.ack_count = ctf_decay_count(rack->r_ctl.ack_count,
9026 							tcp_sad_decay_val);
9027 		rack->r_ctl.sack_count = ctf_decay_count(rack->r_ctl.sack_count,
9028 							 tcp_sad_decay_val);
9029 		rack->r_ctl.sack_moved_extra = ctf_decay_count(rack->r_ctl.sack_moved_extra,
9030 							       tcp_sad_decay_val);
9031 		rack->r_ctl.sack_noextra_move = ctf_decay_count(rack->r_ctl.sack_noextra_move,
9032 								tcp_sad_decay_val);
9033 #endif
9034 	}
9035 }
9036 
9037 static void
9038 rack_process_to_cumack(struct tcpcb *tp, struct tcp_rack *rack, register uint32_t th_ack, uint32_t cts, struct tcpopt *to)
9039 {
9040 	struct rack_sendmap *rsm, *rm;
9041 
9042 	/*
9043 	 * The ACK point is advancing to th_ack, we must drop off
9044 	 * the packets in the rack log and calculate any eligble
9045 	 * RTT's.
9046 	 */
9047 	rack->r_wanted_output = 1;
9048 
9049 	/* Tend any TLP that has been marked for 1/2 the seq space (its old)  */
9050 	if ((rack->rc_last_tlp_acked_set == 1)&&
9051 	    (rack->rc_last_tlp_past_cumack == 1) &&
9052 	    (SEQ_GT(rack->r_ctl.last_tlp_acked_start, th_ack))) {
9053 		/*
9054 		 * We have reached the point where our last rack
9055 		 * tlp retransmit sequence is ahead of the cum-ack.
9056 		 * This can only happen when the cum-ack moves all
9057 		 * the way around (its been a full 2^^31+1 bytes
9058 		 * or more since we sent a retransmitted TLP). Lets
9059 		 * turn off the valid flag since its not really valid.
9060 		 *
9061 		 * Note since sack's also turn on this event we have
9062 		 * a complication, we have to wait to age it out until
9063 		 * the cum-ack is by the TLP before checking which is
9064 		 * what the next else clause does.
9065 		 */
9066 		rack_log_dsack_event(rack, 9, __LINE__,
9067 				     rack->r_ctl.last_tlp_acked_start,
9068 				     rack->r_ctl.last_tlp_acked_end);
9069 		rack->rc_last_tlp_acked_set = 0;
9070 		rack->rc_last_tlp_past_cumack = 0;
9071 	} else if ((rack->rc_last_tlp_acked_set == 1) &&
9072 		   (rack->rc_last_tlp_past_cumack == 0) &&
9073 		   (SEQ_GEQ(th_ack, rack->r_ctl.last_tlp_acked_end))) {
9074 		/*
9075 		 * It is safe to start aging TLP's out.
9076 		 */
9077 		rack->rc_last_tlp_past_cumack = 1;
9078 	}
9079 	/* We do the same for the tlp send seq as well */
9080 	if ((rack->rc_last_sent_tlp_seq_valid == 1) &&
9081 	    (rack->rc_last_sent_tlp_past_cumack == 1) &&
9082 	    (SEQ_GT(rack->r_ctl.last_sent_tlp_seq,  th_ack))) {
9083 		rack_log_dsack_event(rack, 9, __LINE__,
9084 				     rack->r_ctl.last_sent_tlp_seq,
9085 				     (rack->r_ctl.last_sent_tlp_seq +
9086 				      rack->r_ctl.last_sent_tlp_len));
9087 		rack->rc_last_sent_tlp_seq_valid = 0;
9088 		rack->rc_last_sent_tlp_past_cumack = 0;
9089 	} else if ((rack->rc_last_sent_tlp_seq_valid == 1) &&
9090 		   (rack->rc_last_sent_tlp_past_cumack == 0) &&
9091 		   (SEQ_GEQ(th_ack, rack->r_ctl.last_sent_tlp_seq))) {
9092 		/*
9093 		 * It is safe to start aging TLP's send.
9094 		 */
9095 		rack->rc_last_sent_tlp_past_cumack = 1;
9096 	}
9097 more:
9098 	rsm = RB_MIN(rack_rb_tree_head, &rack->r_ctl.rc_mtree);
9099 	if (rsm == NULL) {
9100 		if ((th_ack - 1) == tp->iss) {
9101 			/*
9102 			 * For the SYN incoming case we will not
9103 			 * have called tcp_output for the sending of
9104 			 * the SYN, so there will be no map. All
9105 			 * other cases should probably be a panic.
9106 			 */
9107 			return;
9108 		}
9109 		if (tp->t_flags & TF_SENTFIN) {
9110 			/* if we sent a FIN we often will not have map */
9111 			return;
9112 		}
9113 #ifdef INVARIANTS
9114 		panic("No rack map tp:%p for state:%d ack:%u rack:%p snd_una:%u snd_max:%u snd_nxt:%u\n",
9115 		      tp,
9116 		      tp->t_state, th_ack, rack,
9117 		      tp->snd_una, tp->snd_max, tp->snd_nxt);
9118 #endif
9119 		return;
9120 	}
9121 	if (SEQ_LT(th_ack, rsm->r_start)) {
9122 		/* Huh map is missing this */
9123 #ifdef INVARIANTS
9124 		printf("Rack map starts at r_start:%u for th_ack:%u huh? ts:%d rs:%d\n",
9125 		       rsm->r_start,
9126 		       th_ack, tp->t_state, rack->r_state);
9127 #endif
9128 		return;
9129 	}
9130 	rack_update_rtt(tp, rack, rsm, to, cts, CUM_ACKED, th_ack);
9131 
9132 	/* Now was it a retransmitted TLP? */
9133 	if ((rsm->r_flags & RACK_TLP) &&
9134 	    (rsm->r_rtr_cnt > 1)) {
9135 		/*
9136 		 * Yes, this rsm was a TLP and retransmitted, remember that
9137 		 * since if a DSACK comes back on this we don't want
9138 		 * to think of it as a reordered segment. This may
9139 		 * get updated again with possibly even other TLPs
9140 		 * in flight, but thats ok. Only when we don't send
9141 		 * a retransmitted TLP for 1/2 the sequences space
9142 		 * will it get turned off (above).
9143 		 */
9144 		if (rack->rc_last_tlp_acked_set &&
9145 		    (is_rsm_inside_declared_tlp_block(rack, rsm))) {
9146 			/*
9147 			 * We already turned this on since the end matches,
9148 			 * the previous one was a partially ack now we
9149 			 * are getting another one (maybe all of it).
9150 			 */
9151 			rack_log_dsack_event(rack, 10, __LINE__, rsm->r_start, rsm->r_end);
9152 			/*
9153 			 * Lets make sure we have all of it though.
9154 			 */
9155 			if (SEQ_LT(rsm->r_start, rack->r_ctl.last_tlp_acked_start)) {
9156 				rack->r_ctl.last_tlp_acked_start = rsm->r_start;
9157 				rack_log_dsack_event(rack, 11, __LINE__, rack->r_ctl.last_tlp_acked_start,
9158 						     rack->r_ctl.last_tlp_acked_end);
9159 			}
9160 			if (SEQ_GT(rsm->r_end, rack->r_ctl.last_tlp_acked_end)) {
9161 				rack->r_ctl.last_tlp_acked_end = rsm->r_end;
9162 				rack_log_dsack_event(rack, 11, __LINE__, rack->r_ctl.last_tlp_acked_start,
9163 						     rack->r_ctl.last_tlp_acked_end);
9164 			}
9165 		} else {
9166 			rack->rc_last_tlp_past_cumack = 1;
9167 			rack->r_ctl.last_tlp_acked_start = rsm->r_start;
9168 			rack->r_ctl.last_tlp_acked_end = rsm->r_end;
9169 			rack->rc_last_tlp_acked_set = 1;
9170 			rack_log_dsack_event(rack, 8, __LINE__, rsm->r_start, rsm->r_end);
9171 		}
9172 	}
9173 	/* Now do we consume the whole thing? */
9174 	if (SEQ_GEQ(th_ack, rsm->r_end)) {
9175 		/* Its all consumed. */
9176 		uint32_t left;
9177 		uint8_t newly_acked;
9178 
9179 		rack_log_map_chg(tp, rack, NULL, rsm, NULL, MAP_FREE, rsm->r_end, __LINE__);
9180 		rack->r_ctl.rc_holes_rxt -= rsm->r_rtr_bytes;
9181 		rsm->r_rtr_bytes = 0;
9182 		/* Record the time of highest cumack sent */
9183 		rack->r_ctl.rc_gp_cumack_ts = rsm->r_tim_lastsent[(rsm->r_rtr_cnt-1)];
9184 		rm = RB_REMOVE(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm);
9185 #ifdef INVARIANTS
9186 		if (rm != rsm) {
9187 			panic("removing head in rack:%p rsm:%p rm:%p",
9188 			      rack, rsm, rm);
9189 		}
9190 #endif
9191 		if (rsm->r_in_tmap) {
9192 			TAILQ_REMOVE(&rack->r_ctl.rc_tmap, rsm, r_tnext);
9193 			rsm->r_in_tmap = 0;
9194 		}
9195 		newly_acked = 1;
9196 		if (rsm->r_flags & RACK_ACKED) {
9197 			/*
9198 			 * It was acked on the scoreboard -- remove
9199 			 * it from total
9200 			 */
9201 			rack->r_ctl.rc_sacked -= (rsm->r_end - rsm->r_start);
9202 			newly_acked = 0;
9203 		} else if (rsm->r_flags & RACK_SACK_PASSED) {
9204 			/*
9205 			 * There are segments ACKED on the
9206 			 * scoreboard further up. We are seeing
9207 			 * reordering.
9208 			 */
9209 			rsm->r_flags &= ~RACK_SACK_PASSED;
9210 			counter_u64_add(rack_reorder_seen, 1);
9211 			rsm->r_ack_arrival = rack_to_usec_ts(&rack->r_ctl.act_rcv_time);
9212 			rsm->r_flags |= RACK_ACKED;
9213 			rack->r_ctl.rc_reorder_ts = cts;
9214 			if (rack->r_ent_rec_ns) {
9215 				/*
9216 				 * We have sent no more, and we saw an sack
9217 				 * then ack arrive.
9218 				 */
9219 				rack->r_might_revert = 1;
9220 			}
9221 		}
9222 		if ((rsm->r_flags & RACK_TO_REXT) &&
9223 		    (tp->t_flags & TF_RCVD_TSTMP) &&
9224 		    (to->to_flags & TOF_TS) &&
9225 		    (to->to_tsecr != 0) &&
9226 		    (tp->t_flags & TF_PREVVALID)) {
9227 			/*
9228 			 * We can use the timestamp to see
9229 			 * if this retransmission was from the
9230 			 * first transmit. If so we made a mistake.
9231 			 */
9232 			tp->t_flags &= ~TF_PREVVALID;
9233 			if (to->to_tsecr == rack_ts_to_msec(rsm->r_tim_lastsent[0])) {
9234 				/* The first transmit is what this ack is for */
9235 				rack_cong_signal(tp, CC_RTO_ERR, th_ack);
9236 			}
9237 		}
9238 		left = th_ack - rsm->r_end;
9239 		if (rack->app_limited_needs_set && newly_acked)
9240 			rack_need_set_test(tp, rack, rsm, th_ack, __LINE__, RACK_USE_END_OR_THACK);
9241 		/* Free back to zone */
9242 		rack_free(rack, rsm);
9243 		if (left) {
9244 			goto more;
9245 		}
9246 		/* Check for reneging */
9247 		rsm = RB_MIN(rack_rb_tree_head, &rack->r_ctl.rc_mtree);
9248 		if (rsm && (rsm->r_flags & RACK_ACKED) && (th_ack == rsm->r_start)) {
9249 			/*
9250 			 * The peer has moved snd_una up to
9251 			 * the edge of this send, i.e. one
9252 			 * that it had previously acked. The only
9253 			 * way that can be true if the peer threw
9254 			 * away data (space issues) that it had
9255 			 * previously sacked (else it would have
9256 			 * given us snd_una up to (rsm->r_end).
9257 			 * We need to undo the acked markings here.
9258 			 *
9259 			 * Note we have to look to make sure th_ack is
9260 			 * our rsm->r_start in case we get an old ack
9261 			 * where th_ack is behind snd_una.
9262 			 */
9263 			rack_peer_reneges(rack, rsm, th_ack);
9264 		}
9265 		return;
9266 	}
9267 	if (rsm->r_flags & RACK_ACKED) {
9268 		/*
9269 		 * It was acked on the scoreboard -- remove it from
9270 		 * total for the part being cum-acked.
9271 		 */
9272 		rack->r_ctl.rc_sacked -= (th_ack - rsm->r_start);
9273 	}
9274 	/*
9275 	 * Clear the dup ack count for
9276 	 * the piece that remains.
9277 	 */
9278 	rsm->r_dupack = 0;
9279 	rack_log_retran_reason(rack, rsm, __LINE__, 0, 2);
9280 	if (rsm->r_rtr_bytes) {
9281 		/*
9282 		 * It was retransmitted adjust the
9283 		 * sack holes for what was acked.
9284 		 */
9285 		int ack_am;
9286 
9287 		ack_am = (th_ack - rsm->r_start);
9288 		if (ack_am >= rsm->r_rtr_bytes) {
9289 			rack->r_ctl.rc_holes_rxt -= ack_am;
9290 			rsm->r_rtr_bytes -= ack_am;
9291 		}
9292 	}
9293 	/*
9294 	 * Update where the piece starts and record
9295 	 * the time of send of highest cumack sent.
9296 	 */
9297 	rack->r_ctl.rc_gp_cumack_ts = rsm->r_tim_lastsent[(rsm->r_rtr_cnt-1)];
9298 	rack_log_map_chg(tp, rack, NULL, rsm, NULL, MAP_TRIM_HEAD, th_ack, __LINE__);
9299 	/* Now we need to move our offset forward too */
9300 	if (rsm->m && (rsm->orig_m_len != rsm->m->m_len)) {
9301 		/* Fix up the orig_m_len and possibly the mbuf offset */
9302 		rack_adjust_orig_mlen(rsm);
9303 	}
9304 	rsm->soff += (th_ack - rsm->r_start);
9305 	rsm->r_start = th_ack;
9306 	/* Now do we need to move the mbuf fwd too? */
9307 	if (rsm->m) {
9308 		while (rsm->soff >= rsm->m->m_len) {
9309 			rsm->soff -= rsm->m->m_len;
9310 			rsm->m = rsm->m->m_next;
9311 			KASSERT((rsm->m != NULL),
9312 				(" nrsm:%p hit at soff:%u null m",
9313 				 rsm, rsm->soff));
9314 		}
9315 		rsm->orig_m_len = rsm->m->m_len;
9316 	}
9317 	if (rack->app_limited_needs_set)
9318 		rack_need_set_test(tp, rack, rsm, tp->snd_una, __LINE__, RACK_USE_BEG);
9319 }
9320 
9321 static void
9322 rack_handle_might_revert(struct tcpcb *tp, struct tcp_rack *rack)
9323 {
9324 	struct rack_sendmap *rsm;
9325 	int sack_pass_fnd = 0;
9326 
9327 	if (rack->r_might_revert) {
9328 		/*
9329 		 * Ok we have reordering, have not sent anything, we
9330 		 * might want to revert the congestion state if nothing
9331 		 * further has SACK_PASSED on it. Lets check.
9332 		 *
9333 		 * We also get here when we have DSACKs come in for
9334 		 * all the data that we FR'd. Note that a rxt or tlp
9335 		 * timer clears this from happening.
9336 		 */
9337 
9338 		TAILQ_FOREACH(rsm, &rack->r_ctl.rc_tmap, r_tnext) {
9339 			if (rsm->r_flags & RACK_SACK_PASSED) {
9340 				sack_pass_fnd = 1;
9341 				break;
9342 			}
9343 		}
9344 		if (sack_pass_fnd == 0) {
9345 			/*
9346 			 * We went into recovery
9347 			 * incorrectly due to reordering!
9348 			 */
9349 			int orig_cwnd;
9350 
9351 			rack->r_ent_rec_ns = 0;
9352 			orig_cwnd = tp->snd_cwnd;
9353 			tp->snd_cwnd = rack->r_ctl.rc_cwnd_at_erec;
9354 			tp->snd_ssthresh = rack->r_ctl.rc_ssthresh_at_erec;
9355 			tp->snd_recover = tp->snd_una;
9356 			rack_log_to_prr(rack, 14, orig_cwnd);
9357 			EXIT_RECOVERY(tp->t_flags);
9358 		}
9359 		rack->r_might_revert = 0;
9360 	}
9361 }
9362 
9363 #ifdef NETFLIX_EXP_DETECTION
9364 static void
9365 rack_do_detection(struct tcpcb *tp, struct tcp_rack *rack,  uint32_t bytes_this_ack, uint32_t segsiz)
9366 {
9367 	if ((rack->do_detection || tcp_force_detection) &&
9368 	    tcp_sack_to_ack_thresh &&
9369 	    tcp_sack_to_move_thresh &&
9370 	    ((rack->r_ctl.rc_num_maps_alloced > tcp_map_minimum) || rack->sack_attack_disable)) {
9371 		/*
9372 		 * We have thresholds set to find
9373 		 * possible attackers and disable sack.
9374 		 * Check them.
9375 		 */
9376 		uint64_t ackratio, moveratio, movetotal;
9377 
9378 		/* Log detecting */
9379 		rack_log_sad(rack, 1);
9380 		ackratio = (uint64_t)(rack->r_ctl.sack_count);
9381 		ackratio *= (uint64_t)(1000);
9382 		if (rack->r_ctl.ack_count)
9383 			ackratio /= (uint64_t)(rack->r_ctl.ack_count);
9384 		else {
9385 			/* We really should not hit here */
9386 			ackratio = 1000;
9387 		}
9388 		if ((rack->sack_attack_disable == 0) &&
9389 		    (ackratio > rack_highest_sack_thresh_seen))
9390 			rack_highest_sack_thresh_seen = (uint32_t)ackratio;
9391 		movetotal = rack->r_ctl.sack_moved_extra;
9392 		movetotal += rack->r_ctl.sack_noextra_move;
9393 		moveratio = rack->r_ctl.sack_moved_extra;
9394 		moveratio *= (uint64_t)1000;
9395 		if (movetotal)
9396 			moveratio /= movetotal;
9397 		else {
9398 			/* No moves, thats pretty good */
9399 			moveratio = 0;
9400 		}
9401 		if ((rack->sack_attack_disable == 0) &&
9402 		    (moveratio > rack_highest_move_thresh_seen))
9403 			rack_highest_move_thresh_seen = (uint32_t)moveratio;
9404 		if (rack->sack_attack_disable == 0) {
9405 			if ((ackratio > tcp_sack_to_ack_thresh) &&
9406 			    (moveratio > tcp_sack_to_move_thresh)) {
9407 				/* Disable sack processing */
9408 				rack->sack_attack_disable = 1;
9409 				if (rack->r_rep_attack == 0) {
9410 					rack->r_rep_attack = 1;
9411 					counter_u64_add(rack_sack_attacks_detected, 1);
9412 				}
9413 				if (tcp_attack_on_turns_on_logging) {
9414 					/*
9415 					 * Turn on logging, used for debugging
9416 					 * false positives.
9417 					 */
9418 					rack->rc_tp->t_logstate = tcp_attack_on_turns_on_logging;
9419 				}
9420 				/* Clamp the cwnd at flight size */
9421 				rack->r_ctl.rc_saved_cwnd = rack->rc_tp->snd_cwnd;
9422 				rack->rc_tp->snd_cwnd = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
9423 				rack_log_sad(rack, 2);
9424 			}
9425 		} else {
9426 			/* We are sack-disabled check for false positives */
9427 			if ((ackratio <= tcp_restoral_thresh) ||
9428 			    (rack->r_ctl.rc_num_maps_alloced  < tcp_map_minimum)) {
9429 				rack->sack_attack_disable = 0;
9430 				rack_log_sad(rack, 3);
9431 				/* Restart counting */
9432 				rack->r_ctl.sack_count = 0;
9433 				rack->r_ctl.sack_moved_extra = 0;
9434 				rack->r_ctl.sack_noextra_move = 1;
9435 				rack->r_ctl.ack_count = max(1,
9436 				      (bytes_this_ack / segsiz));
9437 
9438 				if (rack->r_rep_reverse == 0) {
9439 					rack->r_rep_reverse = 1;
9440 					counter_u64_add(rack_sack_attacks_reversed, 1);
9441 				}
9442 				/* Restore the cwnd */
9443 				if (rack->r_ctl.rc_saved_cwnd > rack->rc_tp->snd_cwnd)
9444 					rack->rc_tp->snd_cwnd = rack->r_ctl.rc_saved_cwnd;
9445 			}
9446 		}
9447 	}
9448 }
9449 #endif
9450 
9451 static int
9452 rack_note_dsack(struct tcp_rack *rack, tcp_seq start, tcp_seq end)
9453 {
9454 
9455 	uint32_t am, l_end;
9456 	int was_tlp = 0;
9457 
9458 	if (SEQ_GT(end, start))
9459 		am = end - start;
9460 	else
9461 		am = 0;
9462 	if ((rack->rc_last_tlp_acked_set ) &&
9463 	    (SEQ_GEQ(start, rack->r_ctl.last_tlp_acked_start)) &&
9464 	    (SEQ_LEQ(end, rack->r_ctl.last_tlp_acked_end))) {
9465 		/*
9466 		 * The DSACK is because of a TLP which we don't
9467 		 * do anything with the reordering window over since
9468 		 * it was not reordering that caused the DSACK but
9469 		 * our previous retransmit TLP.
9470 		 */
9471 		rack_log_dsack_event(rack, 7, __LINE__, start, end);
9472 		was_tlp = 1;
9473 		goto skip_dsack_round;
9474 	}
9475 	if (rack->rc_last_sent_tlp_seq_valid) {
9476 		l_end = rack->r_ctl.last_sent_tlp_seq + rack->r_ctl.last_sent_tlp_len;
9477 		if (SEQ_GEQ(start, rack->r_ctl.last_sent_tlp_seq) &&
9478 		    (SEQ_LEQ(end, l_end))) {
9479 			/*
9480 			 * This dsack is from the last sent TLP, ignore it
9481 			 * for reordering purposes.
9482 			 */
9483 			rack_log_dsack_event(rack, 7, __LINE__, start, end);
9484 			was_tlp = 1;
9485 			goto skip_dsack_round;
9486 		}
9487 	}
9488 	if (rack->rc_dsack_round_seen == 0) {
9489 		rack->rc_dsack_round_seen = 1;
9490 		rack->r_ctl.dsack_round_end = rack->rc_tp->snd_max;
9491 		rack->r_ctl.num_dsack++;
9492 		rack->r_ctl.dsack_persist = 16;	/* 16 is from the standard */
9493 		rack_log_dsack_event(rack, 2, __LINE__, 0, 0);
9494 	}
9495 skip_dsack_round:
9496 	/*
9497 	 * We keep track of how many DSACK blocks we get
9498 	 * after a recovery incident.
9499 	 */
9500 	rack->r_ctl.dsack_byte_cnt += am;
9501 	if (!IN_FASTRECOVERY(rack->rc_tp->t_flags) &&
9502 	    rack->r_ctl.retran_during_recovery &&
9503 	    (rack->r_ctl.dsack_byte_cnt >= rack->r_ctl.retran_during_recovery)) {
9504 		/*
9505 		 * False recovery most likely culprit is reordering. If
9506 		 * nothing else is missing we need to revert.
9507 		 */
9508 		rack->r_might_revert = 1;
9509 		rack_handle_might_revert(rack->rc_tp, rack);
9510 		rack->r_might_revert = 0;
9511 		rack->r_ctl.retran_during_recovery = 0;
9512 		rack->r_ctl.dsack_byte_cnt = 0;
9513 	}
9514 	return (was_tlp);
9515 }
9516 
9517 static void
9518 rack_update_prr(struct tcpcb *tp, struct tcp_rack *rack, uint32_t changed, tcp_seq th_ack)
9519 {
9520 	/* Deal with changed and PRR here (in recovery only) */
9521 	uint32_t pipe, snd_una;
9522 
9523 	rack->r_ctl.rc_prr_delivered += changed;
9524 
9525 	if (sbavail(&rack->rc_inp->inp_socket->so_snd) <= (tp->snd_max - tp->snd_una)) {
9526 		/*
9527 		 * It is all outstanding, we are application limited
9528 		 * and thus we don't need more room to send anything.
9529 		 * Note we use tp->snd_una here and not th_ack because
9530 		 * the data as yet not been cut from the sb.
9531 		 */
9532 		rack->r_ctl.rc_prr_sndcnt = 0;
9533 		return;
9534 	}
9535 	/* Compute prr_sndcnt */
9536 	if (SEQ_GT(tp->snd_una, th_ack)) {
9537 		snd_una = tp->snd_una;
9538 	} else {
9539 		snd_una = th_ack;
9540 	}
9541 	pipe = ((tp->snd_max - snd_una) - rack->r_ctl.rc_sacked) + rack->r_ctl.rc_holes_rxt;
9542 	if (pipe > tp->snd_ssthresh) {
9543 		long sndcnt;
9544 
9545 		sndcnt = rack->r_ctl.rc_prr_delivered * tp->snd_ssthresh;
9546 		if (rack->r_ctl.rc_prr_recovery_fs > 0)
9547 			sndcnt /= (long)rack->r_ctl.rc_prr_recovery_fs;
9548 		else {
9549 			rack->r_ctl.rc_prr_sndcnt = 0;
9550 			rack_log_to_prr(rack, 9, 0);
9551 			sndcnt = 0;
9552 		}
9553 		sndcnt++;
9554 		if (sndcnt > (long)rack->r_ctl.rc_prr_out)
9555 			sndcnt -= rack->r_ctl.rc_prr_out;
9556 		else
9557 			sndcnt = 0;
9558 		rack->r_ctl.rc_prr_sndcnt = sndcnt;
9559 		rack_log_to_prr(rack, 10, 0);
9560 	} else {
9561 		uint32_t limit;
9562 
9563 		if (rack->r_ctl.rc_prr_delivered > rack->r_ctl.rc_prr_out)
9564 			limit = (rack->r_ctl.rc_prr_delivered - rack->r_ctl.rc_prr_out);
9565 		else
9566 			limit = 0;
9567 		if (changed > limit)
9568 			limit = changed;
9569 		limit += ctf_fixed_maxseg(tp);
9570 		if (tp->snd_ssthresh > pipe) {
9571 			rack->r_ctl.rc_prr_sndcnt = min((tp->snd_ssthresh - pipe), limit);
9572 			rack_log_to_prr(rack, 11, 0);
9573 		} else {
9574 			rack->r_ctl.rc_prr_sndcnt = min(0, limit);
9575 			rack_log_to_prr(rack, 12, 0);
9576 		}
9577 	}
9578 }
9579 
9580 static void
9581 rack_log_ack(struct tcpcb *tp, struct tcpopt *to, struct tcphdr *th, int entered_recovery, int dup_ack_struck)
9582 {
9583 	uint32_t changed;
9584 	struct tcp_rack *rack;
9585 	struct rack_sendmap *rsm;
9586 	struct sackblk sack, sack_blocks[TCP_MAX_SACK + 1];
9587 	register uint32_t th_ack;
9588 	int32_t i, j, k, num_sack_blks = 0;
9589 	uint32_t cts, acked, ack_point, sack_changed = 0;
9590 	int loop_start = 0, moved_two = 0;
9591 	uint32_t tsused;
9592 
9593 
9594 	INP_WLOCK_ASSERT(tp->t_inpcb);
9595 	if (th->th_flags & TH_RST) {
9596 		/* We don't log resets */
9597 		return;
9598 	}
9599 	rack = (struct tcp_rack *)tp->t_fb_ptr;
9600 	cts = tcp_get_usecs(NULL);
9601 	rsm = RB_MIN(rack_rb_tree_head, &rack->r_ctl.rc_mtree);
9602 	changed = 0;
9603 	th_ack = th->th_ack;
9604 	if (rack->sack_attack_disable == 0)
9605 		rack_do_decay(rack);
9606 	if (BYTES_THIS_ACK(tp, th) >= ctf_fixed_maxseg(rack->rc_tp)) {
9607 		/*
9608 		 * You only get credit for
9609 		 * MSS and greater (and you get extra
9610 		 * credit for larger cum-ack moves).
9611 		 */
9612 		int ac;
9613 
9614 		ac = BYTES_THIS_ACK(tp, th) / ctf_fixed_maxseg(rack->rc_tp);
9615 		rack->r_ctl.ack_count += ac;
9616 		counter_u64_add(rack_ack_total, ac);
9617 	}
9618 	if (rack->r_ctl.ack_count > 0xfff00000) {
9619 		/*
9620 		 * reduce the number to keep us under
9621 		 * a uint32_t.
9622 		 */
9623 		rack->r_ctl.ack_count /= 2;
9624 		rack->r_ctl.sack_count /= 2;
9625 	}
9626 	if (SEQ_GT(th_ack, tp->snd_una)) {
9627 		rack_log_progress_event(rack, tp, ticks, PROGRESS_UPDATE, __LINE__);
9628 		tp->t_acktime = ticks;
9629 	}
9630 	if (rsm && SEQ_GT(th_ack, rsm->r_start))
9631 		changed = th_ack - rsm->r_start;
9632 	if (changed) {
9633 		rack_process_to_cumack(tp, rack, th_ack, cts, to);
9634 	}
9635 	if ((to->to_flags & TOF_SACK) == 0) {
9636 		/* We are done nothing left and no sack. */
9637 		rack_handle_might_revert(tp, rack);
9638 		/*
9639 		 * For cases where we struck a dup-ack
9640 		 * with no SACK, add to the changes so
9641 		 * PRR will work right.
9642 		 */
9643 		if (dup_ack_struck && (changed == 0)) {
9644 			changed += ctf_fixed_maxseg(rack->rc_tp);
9645 		}
9646 		goto out;
9647 	}
9648 	/* Sack block processing */
9649 	if (SEQ_GT(th_ack, tp->snd_una))
9650 		ack_point = th_ack;
9651 	else
9652 		ack_point = tp->snd_una;
9653 	for (i = 0; i < to->to_nsacks; i++) {
9654 		bcopy((to->to_sacks + i * TCPOLEN_SACK),
9655 		      &sack, sizeof(sack));
9656 		sack.start = ntohl(sack.start);
9657 		sack.end = ntohl(sack.end);
9658 		if (SEQ_GT(sack.end, sack.start) &&
9659 		    SEQ_GT(sack.start, ack_point) &&
9660 		    SEQ_LT(sack.start, tp->snd_max) &&
9661 		    SEQ_GT(sack.end, ack_point) &&
9662 		    SEQ_LEQ(sack.end, tp->snd_max)) {
9663 			sack_blocks[num_sack_blks] = sack;
9664 			num_sack_blks++;
9665 		} else if (SEQ_LEQ(sack.start, th_ack) &&
9666 			   SEQ_LEQ(sack.end, th_ack)) {
9667 			int was_tlp;
9668 
9669 			was_tlp = rack_note_dsack(rack, sack.start, sack.end);
9670 			/*
9671 			 * Its a D-SACK block.
9672 			 */
9673 			tcp_record_dsack(tp, sack.start, sack.end, was_tlp);
9674 		}
9675 	}
9676 	if (rack->rc_dsack_round_seen) {
9677 		/* Is the dsack roound over? */
9678 		if (SEQ_GEQ(th_ack, rack->r_ctl.dsack_round_end)) {
9679 			/* Yes it is */
9680 			rack->rc_dsack_round_seen = 0;
9681 			rack_log_dsack_event(rack, 3, __LINE__, 0, 0);
9682 		}
9683 	}
9684 	/*
9685 	 * Sort the SACK blocks so we can update the rack scoreboard with
9686 	 * just one pass.
9687 	 */
9688 	num_sack_blks = sack_filter_blks(&rack->r_ctl.rack_sf, sack_blocks,
9689 					 num_sack_blks, th->th_ack);
9690 	ctf_log_sack_filter(rack->rc_tp, num_sack_blks, sack_blocks);
9691 	if (num_sack_blks == 0) {
9692 		/* Nothing to sack (DSACKs?) */
9693 		goto out_with_totals;
9694 	}
9695 	if (num_sack_blks < 2) {
9696 		/* Only one, we don't need to sort */
9697 		goto do_sack_work;
9698 	}
9699 	/* Sort the sacks */
9700 	for (i = 0; i < num_sack_blks; i++) {
9701 		for (j = i + 1; j < num_sack_blks; j++) {
9702 			if (SEQ_GT(sack_blocks[i].end, sack_blocks[j].end)) {
9703 				sack = sack_blocks[i];
9704 				sack_blocks[i] = sack_blocks[j];
9705 				sack_blocks[j] = sack;
9706 			}
9707 		}
9708 	}
9709 	/*
9710 	 * Now are any of the sack block ends the same (yes some
9711 	 * implementations send these)?
9712 	 */
9713 again:
9714 	if (num_sack_blks == 0)
9715 		goto out_with_totals;
9716 	if (num_sack_blks > 1) {
9717 		for (i = 0; i < num_sack_blks; i++) {
9718 			for (j = i + 1; j < num_sack_blks; j++) {
9719 				if (sack_blocks[i].end == sack_blocks[j].end) {
9720 					/*
9721 					 * Ok these two have the same end we
9722 					 * want the smallest end and then
9723 					 * throw away the larger and start
9724 					 * again.
9725 					 */
9726 					if (SEQ_LT(sack_blocks[j].start, sack_blocks[i].start)) {
9727 						/*
9728 						 * The second block covers
9729 						 * more area use that
9730 						 */
9731 						sack_blocks[i].start = sack_blocks[j].start;
9732 					}
9733 					/*
9734 					 * Now collapse out the dup-sack and
9735 					 * lower the count
9736 					 */
9737 					for (k = (j + 1); k < num_sack_blks; k++) {
9738 						sack_blocks[j].start = sack_blocks[k].start;
9739 						sack_blocks[j].end = sack_blocks[k].end;
9740 						j++;
9741 					}
9742 					num_sack_blks--;
9743 					goto again;
9744 				}
9745 			}
9746 		}
9747 	}
9748 do_sack_work:
9749 	/*
9750 	 * First lets look to see if
9751 	 * we have retransmitted and
9752 	 * can use the transmit next?
9753 	 */
9754 	rsm = TAILQ_FIRST(&rack->r_ctl.rc_tmap);
9755 	if (rsm &&
9756 	    SEQ_GT(sack_blocks[0].end, rsm->r_start) &&
9757 	    SEQ_LT(sack_blocks[0].start, rsm->r_end)) {
9758 		/*
9759 		 * We probably did the FR and the next
9760 		 * SACK in continues as we would expect.
9761 		 */
9762 		acked = rack_proc_sack_blk(tp, rack, &sack_blocks[0], to, &rsm, cts, &moved_two);
9763 		if (acked) {
9764 			rack->r_wanted_output = 1;
9765 			changed += acked;
9766 			sack_changed += acked;
9767 		}
9768 		if (num_sack_blks == 1) {
9769 			/*
9770 			 * This is what we would expect from
9771 			 * a normal implementation to happen
9772 			 * after we have retransmitted the FR,
9773 			 * i.e the sack-filter pushes down
9774 			 * to 1 block and the next to be retransmitted
9775 			 * is the sequence in the sack block (has more
9776 			 * are acked). Count this as ACK'd data to boost
9777 			 * up the chances of recovering any false positives.
9778 			 */
9779 			rack->r_ctl.ack_count += (acked / ctf_fixed_maxseg(rack->rc_tp));
9780 			counter_u64_add(rack_ack_total, (acked / ctf_fixed_maxseg(rack->rc_tp)));
9781 			counter_u64_add(rack_express_sack, 1);
9782 			if (rack->r_ctl.ack_count > 0xfff00000) {
9783 				/*
9784 				 * reduce the number to keep us under
9785 				 * a uint32_t.
9786 				 */
9787 				rack->r_ctl.ack_count /= 2;
9788 				rack->r_ctl.sack_count /= 2;
9789 			}
9790 			goto out_with_totals;
9791 		} else {
9792 			/*
9793 			 * Start the loop through the
9794 			 * rest of blocks, past the first block.
9795 			 */
9796 			moved_two = 0;
9797 			loop_start = 1;
9798 		}
9799 	}
9800 	/* Its a sack of some sort */
9801 	rack->r_ctl.sack_count++;
9802 	if (rack->r_ctl.sack_count > 0xfff00000) {
9803 		/*
9804 		 * reduce the number to keep us under
9805 		 * a uint32_t.
9806 		 */
9807 		rack->r_ctl.ack_count /= 2;
9808 		rack->r_ctl.sack_count /= 2;
9809 	}
9810 	counter_u64_add(rack_sack_total, 1);
9811 	if (rack->sack_attack_disable) {
9812 		/* An attacker disablement is in place */
9813 		if (num_sack_blks > 1) {
9814 			rack->r_ctl.sack_count += (num_sack_blks - 1);
9815 			rack->r_ctl.sack_moved_extra++;
9816 			counter_u64_add(rack_move_some, 1);
9817 			if (rack->r_ctl.sack_moved_extra > 0xfff00000) {
9818 				rack->r_ctl.sack_moved_extra /= 2;
9819 				rack->r_ctl.sack_noextra_move /= 2;
9820 			}
9821 		}
9822 		goto out;
9823 	}
9824 	rsm = rack->r_ctl.rc_sacklast;
9825 	for (i = loop_start; i < num_sack_blks; i++) {
9826 		acked = rack_proc_sack_blk(tp, rack, &sack_blocks[i], to, &rsm, cts, &moved_two);
9827 		if (acked) {
9828 			rack->r_wanted_output = 1;
9829 			changed += acked;
9830 			sack_changed += acked;
9831 		}
9832 		if (moved_two) {
9833 			/*
9834 			 * If we did not get a SACK for at least a MSS and
9835 			 * had to move at all, or if we moved more than our
9836 			 * threshold, it counts against the "extra" move.
9837 			 */
9838 			rack->r_ctl.sack_moved_extra += moved_two;
9839 			counter_u64_add(rack_move_some, 1);
9840 		} else {
9841 			/*
9842 			 * else we did not have to move
9843 			 * any more than we would expect.
9844 			 */
9845 			rack->r_ctl.sack_noextra_move++;
9846 			counter_u64_add(rack_move_none, 1);
9847 		}
9848 		if (moved_two && (acked < ctf_fixed_maxseg(rack->rc_tp))) {
9849 			/*
9850 			 * If the SACK was not a full MSS then
9851 			 * we add to sack_count the number of
9852 			 * MSS's (or possibly more than
9853 			 * a MSS if its a TSO send) we had to skip by.
9854 			 */
9855 			rack->r_ctl.sack_count += moved_two;
9856 			counter_u64_add(rack_sack_total, moved_two);
9857 		}
9858 		/*
9859 		 * Now we need to setup for the next
9860 		 * round. First we make sure we won't
9861 		 * exceed the size of our uint32_t on
9862 		 * the various counts, and then clear out
9863 		 * moved_two.
9864 		 */
9865 		if ((rack->r_ctl.sack_moved_extra > 0xfff00000) ||
9866 		    (rack->r_ctl.sack_noextra_move > 0xfff00000)) {
9867 			rack->r_ctl.sack_moved_extra /= 2;
9868 			rack->r_ctl.sack_noextra_move /= 2;
9869 		}
9870 		if (rack->r_ctl.sack_count > 0xfff00000) {
9871 			rack->r_ctl.ack_count /= 2;
9872 			rack->r_ctl.sack_count /= 2;
9873 		}
9874 		moved_two = 0;
9875 	}
9876 out_with_totals:
9877 	if (num_sack_blks > 1) {
9878 		/*
9879 		 * You get an extra stroke if
9880 		 * you have more than one sack-blk, this
9881 		 * could be where we are skipping forward
9882 		 * and the sack-filter is still working, or
9883 		 * it could be an attacker constantly
9884 		 * moving us.
9885 		 */
9886 		rack->r_ctl.sack_moved_extra++;
9887 		counter_u64_add(rack_move_some, 1);
9888 	}
9889 out:
9890 #ifdef NETFLIX_EXP_DETECTION
9891 	rack_do_detection(tp, rack, BYTES_THIS_ACK(tp, th), ctf_fixed_maxseg(rack->rc_tp));
9892 #endif
9893 	if (changed) {
9894 		/* Something changed cancel the rack timer */
9895 		rack_timer_cancel(tp, rack, rack->r_ctl.rc_rcvtime, __LINE__);
9896 	}
9897 	tsused = tcp_get_usecs(NULL);
9898 	rsm = tcp_rack_output(tp, rack, tsused);
9899 	if ((!IN_FASTRECOVERY(tp->t_flags)) &&
9900 	    rsm) {
9901 		/* Enter recovery */
9902 		rack->r_ctl.rc_rsm_start = rsm->r_start;
9903 		rack->r_ctl.rc_cwnd_at = tp->snd_cwnd;
9904 		rack->r_ctl.rc_ssthresh_at = tp->snd_ssthresh;
9905 		entered_recovery = 1;
9906 		rack_cong_signal(tp, CC_NDUPACK, tp->snd_una);
9907 		/*
9908 		 * When we enter recovery we need to assure we send
9909 		 * one packet.
9910 		 */
9911 		if (rack->rack_no_prr == 0) {
9912 			rack->r_ctl.rc_prr_sndcnt = ctf_fixed_maxseg(tp);
9913 			rack_log_to_prr(rack, 8, 0);
9914 		}
9915 		rack->r_timer_override = 1;
9916 		rack->r_early = 0;
9917 		rack->r_ctl.rc_agg_early = 0;
9918 	} else if (IN_FASTRECOVERY(tp->t_flags) &&
9919 		   rsm &&
9920 		   (rack->r_rr_config == 3)) {
9921 		/*
9922 		 * Assure we can output and we get no
9923 		 * remembered pace time except the retransmit.
9924 		 */
9925 		rack->r_timer_override = 1;
9926 		rack->r_ctl.rc_hpts_flags &= ~PACE_PKT_OUTPUT;
9927 		rack->r_ctl.rc_resend = rsm;
9928 	}
9929 	if (IN_FASTRECOVERY(tp->t_flags) &&
9930 	    (rack->rack_no_prr == 0) &&
9931 	    (entered_recovery == 0)) {
9932 		rack_update_prr(tp, rack, changed, th_ack);
9933 		if ((rsm && (rack->r_ctl.rc_prr_sndcnt >= ctf_fixed_maxseg(tp)) &&
9934 		     ((rack->rc_inp->inp_in_hpts == 0) &&
9935 		      ((rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT) == 0)))) {
9936 			/*
9937 			 * If you are pacing output you don't want
9938 			 * to override.
9939 			 */
9940 			rack->r_early = 0;
9941 			rack->r_ctl.rc_agg_early = 0;
9942 			rack->r_timer_override = 1;
9943 		}
9944 	}
9945 }
9946 
9947 static void
9948 rack_strike_dupack(struct tcp_rack *rack)
9949 {
9950 	struct rack_sendmap *rsm;
9951 
9952 	rsm = TAILQ_FIRST(&rack->r_ctl.rc_tmap);
9953 	while (rsm && (rsm->r_dupack >= DUP_ACK_THRESHOLD)) {
9954 		rsm = TAILQ_NEXT(rsm, r_tnext);
9955 	}
9956 	if (rsm && (rsm->r_dupack < 0xff)) {
9957 		rsm->r_dupack++;
9958 		if (rsm->r_dupack >= DUP_ACK_THRESHOLD) {
9959 			struct timeval tv;
9960 			uint32_t cts;
9961 			/*
9962 			 * Here we see if we need to retransmit. For
9963 			 * a SACK type connection if enough time has passed
9964 			 * we will get a return of the rsm. For a non-sack
9965 			 * connection we will get the rsm returned if the
9966 			 * dupack value is 3 or more.
9967 			 */
9968 			cts = tcp_get_usecs(&tv);
9969 			rack->r_ctl.rc_resend = tcp_rack_output(rack->rc_tp, rack, cts);
9970 			if (rack->r_ctl.rc_resend != NULL) {
9971 				if (!IN_FASTRECOVERY(rack->rc_tp->t_flags)) {
9972 					rack_cong_signal(rack->rc_tp, CC_NDUPACK,
9973 							 rack->rc_tp->snd_una);
9974 				}
9975 				rack->r_wanted_output = 1;
9976 				rack->r_timer_override = 1;
9977 				rack_log_retran_reason(rack, rsm, __LINE__, 1, 3);
9978 			}
9979 		} else {
9980 			rack_log_retran_reason(rack, rsm, __LINE__, 0, 3);
9981 		}
9982 	}
9983 }
9984 
9985 static void
9986 rack_check_bottom_drag(struct tcpcb *tp,
9987 		       struct tcp_rack *rack,
9988 		       struct socket *so, int32_t acked)
9989 {
9990 	uint32_t segsiz, minseg;
9991 
9992 	segsiz = ctf_fixed_maxseg(tp);
9993 	minseg = segsiz;
9994 
9995 	if (tp->snd_max == tp->snd_una) {
9996 		/*
9997 		 * We are doing dynamic pacing and we are way
9998 		 * under. Basically everything got acked while
9999 		 * we were still waiting on the pacer to expire.
10000 		 *
10001 		 * This means we need to boost the b/w in
10002 		 * addition to any earlier boosting of
10003 		 * the multipler.
10004 		 */
10005 		rack->rc_dragged_bottom = 1;
10006 		rack_validate_multipliers_at_or_above100(rack);
10007 		/*
10008 		 * Lets use the segment bytes acked plus
10009 		 * the lowest RTT seen as the basis to
10010 		 * form a b/w estimate. This will be off
10011 		 * due to the fact that the true estimate
10012 		 * should be around 1/2 the time of the RTT
10013 		 * but we can settle for that.
10014 		 */
10015 		if ((rack->r_ctl.rack_rs.rs_flags & RACK_RTT_VALID) &&
10016 		    acked) {
10017 			uint64_t bw, calc_bw, rtt;
10018 
10019 			rtt = rack->r_ctl.rack_rs.rs_us_rtt;
10020 			if (rtt == 0) {
10021 				/* no us sample is there a ms one? */
10022 				if (rack->r_ctl.rack_rs.rs_rtt_lowest) {
10023 					rtt = rack->r_ctl.rack_rs.rs_rtt_lowest;
10024 				} else {
10025 					goto no_measurement;
10026 				}
10027 			}
10028 			bw = acked;
10029 			calc_bw = bw * 1000000;
10030 			calc_bw /= rtt;
10031 			if (rack->r_ctl.last_max_bw &&
10032 			    (rack->r_ctl.last_max_bw < calc_bw)) {
10033 				/*
10034 				 * If we have a last calculated max bw
10035 				 * enforce it.
10036 				 */
10037 				calc_bw = rack->r_ctl.last_max_bw;
10038 			}
10039 			/* now plop it in */
10040 			if (rack->rc_gp_filled == 0) {
10041 				if (calc_bw > ONE_POINT_TWO_MEG) {
10042 					/*
10043 					 * If we have no measurement
10044 					 * don't let us set in more than
10045 					 * 1.2Mbps. If we are still too
10046 					 * low after pacing with this we
10047 					 * will hopefully have a max b/w
10048 					 * available to sanity check things.
10049 					 */
10050 					calc_bw = ONE_POINT_TWO_MEG;
10051 				}
10052 				rack->r_ctl.rc_rtt_diff = 0;
10053 				rack->r_ctl.gp_bw = calc_bw;
10054 				rack->rc_gp_filled = 1;
10055 				if (rack->r_ctl.num_measurements < RACK_REQ_AVG)
10056 					rack->r_ctl.num_measurements = RACK_REQ_AVG;
10057 				rack_set_pace_segments(rack->rc_tp, rack, __LINE__, NULL);
10058 			} else if (calc_bw > rack->r_ctl.gp_bw) {
10059 				rack->r_ctl.rc_rtt_diff = 0;
10060 				if (rack->r_ctl.num_measurements < RACK_REQ_AVG)
10061 					rack->r_ctl.num_measurements = RACK_REQ_AVG;
10062 				rack->r_ctl.gp_bw = calc_bw;
10063 				rack_set_pace_segments(rack->rc_tp, rack, __LINE__, NULL);
10064 			} else
10065 				rack_increase_bw_mul(rack, -1, 0, 0, 1);
10066 			if ((rack->gp_ready == 0) &&
10067 			    (rack->r_ctl.num_measurements >= rack->r_ctl.req_measurements)) {
10068 				/* We have enough measurements now */
10069 				rack->gp_ready = 1;
10070 				rack_set_cc_pacing(rack);
10071 				if (rack->defer_options)
10072 					rack_apply_deferred_options(rack);
10073 			}
10074 			/*
10075 			 * For acks over 1mss we do a extra boost to simulate
10076 			 * where we would get 2 acks (we want 110 for the mul).
10077 			 */
10078 			if (acked > segsiz)
10079 				rack_increase_bw_mul(rack, -1, 0, 0, 1);
10080 		} else {
10081 			/*
10082 			 * zero rtt possibly?, settle for just an old increase.
10083 			 */
10084 no_measurement:
10085 			rack_increase_bw_mul(rack, -1, 0, 0, 1);
10086 		}
10087 	} else if ((IN_FASTRECOVERY(tp->t_flags) == 0) &&
10088 		   (sbavail(&so->so_snd) > max((segsiz * (4 + rack_req_segs)),
10089 					       minseg)) &&
10090 		   (rack->r_ctl.cwnd_to_use > max((segsiz * (rack_req_segs + 2)), minseg)) &&
10091 		   (tp->snd_wnd > max((segsiz * (rack_req_segs + 2)), minseg)) &&
10092 		   (ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked) <=
10093 		    (segsiz * rack_req_segs))) {
10094 		/*
10095 		 * We are doing dynamic GP pacing and
10096 		 * we have everything except 1MSS or less
10097 		 * bytes left out. We are still pacing away.
10098 		 * And there is data that could be sent, This
10099 		 * means we are inserting delayed ack time in
10100 		 * our measurements because we are pacing too slow.
10101 		 */
10102 		rack_validate_multipliers_at_or_above100(rack);
10103 		rack->rc_dragged_bottom = 1;
10104 		rack_increase_bw_mul(rack, -1, 0, 0, 1);
10105 	}
10106 }
10107 
10108 
10109 
10110 static void
10111 rack_gain_for_fastoutput(struct tcp_rack *rack, struct tcpcb *tp, struct socket *so, uint32_t acked_amount)
10112 {
10113 	/*
10114 	 * The fast output path is enabled and we
10115 	 * have moved the cumack forward. Lets see if
10116 	 * we can expand forward the fast path length by
10117 	 * that amount. What we would ideally like to
10118 	 * do is increase the number of bytes in the
10119 	 * fast path block (left_to_send) by the
10120 	 * acked amount. However we have to gate that
10121 	 * by two factors:
10122 	 * 1) The amount outstanding and the rwnd of the peer
10123 	 *    (i.e. we don't want to exceed the rwnd of the peer).
10124 	 *    <and>
10125 	 * 2) The amount of data left in the socket buffer (i.e.
10126 	 *    we can't send beyond what is in the buffer).
10127 	 *
10128 	 * Note that this does not take into account any increase
10129 	 * in the cwnd. We will only extend the fast path by
10130 	 * what was acked.
10131 	 */
10132 	uint32_t new_total, gating_val;
10133 
10134 	new_total = acked_amount + rack->r_ctl.fsb.left_to_send;
10135 	gating_val = min((sbavail(&so->so_snd) - (tp->snd_max - tp->snd_una)),
10136 			 (tp->snd_wnd - (tp->snd_max - tp->snd_una)));
10137 	if (new_total <= gating_val) {
10138 		/* We can increase left_to_send by the acked amount */
10139 		counter_u64_add(rack_extended_rfo, 1);
10140 		rack->r_ctl.fsb.left_to_send = new_total;
10141 		KASSERT((rack->r_ctl.fsb.left_to_send <= (sbavail(&rack->rc_inp->inp_socket->so_snd) - (tp->snd_max - tp->snd_una))),
10142 			("rack:%p left_to_send:%u sbavail:%u out:%u",
10143 			 rack, rack->r_ctl.fsb.left_to_send,
10144 			 sbavail(&rack->rc_inp->inp_socket->so_snd),
10145 			 (tp->snd_max - tp->snd_una)));
10146 
10147 	}
10148 }
10149 
10150 static void
10151 rack_adjust_sendmap(struct tcp_rack *rack, struct sockbuf *sb, tcp_seq snd_una)
10152 {
10153 	/*
10154 	 * Here any sendmap entry that points to the
10155 	 * beginning mbuf must be adjusted to the correct
10156 	 * offset. This must be called with:
10157 	 * 1) The socket buffer locked
10158 	 * 2) snd_una adjusted to its new postion.
10159 	 *
10160 	 * Note that (2) implies rack_ack_received has also
10161 	 * been called.
10162 	 *
10163 	 * We grab the first mbuf in the socket buffer and
10164 	 * then go through the front of the sendmap, recalculating
10165 	 * the stored offset for any sendmap entry that has
10166 	 * that mbuf. We must use the sb functions to do this
10167 	 * since its possible an add was done has well as
10168 	 * the subtraction we may have just completed. This should
10169 	 * not be a penalty though, since we just referenced the sb
10170 	 * to go in and trim off the mbufs that we freed (of course
10171 	 * there will be a penalty for the sendmap references though).
10172 	 */
10173 	struct mbuf *m;
10174 	struct rack_sendmap *rsm;
10175 
10176 	SOCKBUF_LOCK_ASSERT(sb);
10177 	m = sb->sb_mb;
10178 	rsm = RB_MIN(rack_rb_tree_head, &rack->r_ctl.rc_mtree);
10179 	if ((rsm == NULL) || (m == NULL)) {
10180 		/* Nothing outstanding */
10181 		return;
10182 	}
10183 	while (rsm->m && (rsm->m == m)) {
10184 		/* one to adjust */
10185 #ifdef INVARIANTS
10186 		struct mbuf *tm;
10187 		uint32_t soff;
10188 
10189 		tm = sbsndmbuf(sb, (rsm->r_start - snd_una), &soff);
10190 		if (rsm->orig_m_len != m->m_len) {
10191 			rack_adjust_orig_mlen(rsm);
10192 		}
10193 		if (rsm->soff != soff) {
10194 			/*
10195 			 * This is not a fatal error, we anticipate it
10196 			 * might happen (the else code), so we count it here
10197 			 * so that under invariant we can see that it really
10198 			 * does happen.
10199 			 */
10200 			counter_u64_add(rack_adjust_map_bw, 1);
10201 		}
10202 		rsm->m = tm;
10203 		rsm->soff = soff;
10204 		if (tm)
10205 			rsm->orig_m_len = rsm->m->m_len;
10206 		else
10207 			rsm->orig_m_len = 0;
10208 #else
10209 		rsm->m = sbsndmbuf(sb, (rsm->r_start - snd_una), &rsm->soff);
10210 		if (rsm->m)
10211 			rsm->orig_m_len = rsm->m->m_len;
10212 		else
10213 			rsm->orig_m_len = 0;
10214 #endif
10215 		rsm = RB_NEXT(rack_rb_tree_head, &rack->r_ctl.rc_mtree,
10216 			      rsm);
10217 		if (rsm == NULL)
10218 			break;
10219 	}
10220 }
10221 
10222 /*
10223  * Return value of 1, we do not need to call rack_process_data().
10224  * return value of 0, rack_process_data can be called.
10225  * For ret_val if its 0 the TCP is locked, if its non-zero
10226  * its unlocked and probably unsafe to touch the TCB.
10227  */
10228 static int
10229 rack_process_ack(struct mbuf *m, struct tcphdr *th, struct socket *so,
10230     struct tcpcb *tp, struct tcpopt *to,
10231     uint32_t tiwin, int32_t tlen,
10232     int32_t * ofia, int32_t thflags, int32_t *ret_val)
10233 {
10234 	int32_t ourfinisacked = 0;
10235 	int32_t nsegs, acked_amount;
10236 	int32_t acked;
10237 	struct mbuf *mfree;
10238 	struct tcp_rack *rack;
10239 	int32_t under_pacing = 0;
10240 	int32_t recovery = 0;
10241 
10242 	rack = (struct tcp_rack *)tp->t_fb_ptr;
10243 	if (SEQ_GT(th->th_ack, tp->snd_max)) {
10244 		__ctf_do_dropafterack(m, tp, th, thflags, tlen, ret_val,
10245 				      &rack->r_ctl.challenge_ack_ts,
10246 				      &rack->r_ctl.challenge_ack_cnt);
10247 		rack->r_wanted_output = 1;
10248 		return (1);
10249 	}
10250 	if (rack->gp_ready &&
10251 	    (rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT)) {
10252 		under_pacing = 1;
10253 	}
10254 	if (SEQ_GEQ(th->th_ack, tp->snd_una) || to->to_nsacks) {
10255 		int in_rec, dup_ack_struck = 0;
10256 
10257 		in_rec = IN_FASTRECOVERY(tp->t_flags);
10258 		if (rack->rc_in_persist) {
10259 			tp->t_rxtshift = 0;
10260 			RACK_TCPT_RANGESET(tp->t_rxtcur, RACK_REXMTVAL(tp),
10261 				      rack_rto_min, rack_rto_max, rack->r_ctl.timer_slop);
10262 		}
10263 		if ((th->th_ack == tp->snd_una) &&
10264 		    (tiwin == tp->snd_wnd) &&
10265 		    ((to->to_flags & TOF_SACK) == 0)) {
10266 			rack_strike_dupack(rack);
10267 			dup_ack_struck = 1;
10268 		}
10269 		rack_log_ack(tp, to, th, ((in_rec == 0) && IN_FASTRECOVERY(tp->t_flags)), dup_ack_struck);
10270 	}
10271 	if (__predict_false(SEQ_LEQ(th->th_ack, tp->snd_una))) {
10272 		/*
10273 		 * Old ack, behind (or duplicate to) the last one rcv'd
10274 		 * Note: We mark reordering is occuring if its
10275 		 * less than and we have not closed our window.
10276 		 */
10277 		if (SEQ_LT(th->th_ack, tp->snd_una) && (sbspace(&so->so_rcv) > ctf_fixed_maxseg(tp))) {
10278 			counter_u64_add(rack_reorder_seen, 1);
10279 			rack->r_ctl.rc_reorder_ts = tcp_tv_to_usectick(&rack->r_ctl.act_rcv_time);
10280 		}
10281 		return (0);
10282 	}
10283 	/*
10284 	 * If we reach this point, ACK is not a duplicate, i.e., it ACKs
10285 	 * something we sent.
10286 	 */
10287 	if (tp->t_flags & TF_NEEDSYN) {
10288 		/*
10289 		 * T/TCP: Connection was half-synchronized, and our SYN has
10290 		 * been ACK'd (so connection is now fully synchronized).  Go
10291 		 * to non-starred state, increment snd_una for ACK of SYN,
10292 		 * and check if we can do window scaling.
10293 		 */
10294 		tp->t_flags &= ~TF_NEEDSYN;
10295 		tp->snd_una++;
10296 		/* Do window scaling? */
10297 		if ((tp->t_flags & (TF_RCVD_SCALE | TF_REQ_SCALE)) ==
10298 		    (TF_RCVD_SCALE | TF_REQ_SCALE)) {
10299 			tp->rcv_scale = tp->request_r_scale;
10300 			/* Send window already scaled. */
10301 		}
10302 	}
10303 	nsegs = max(1, m->m_pkthdr.lro_nsegs);
10304 	INP_WLOCK_ASSERT(tp->t_inpcb);
10305 
10306 	acked = BYTES_THIS_ACK(tp, th);
10307 	KMOD_TCPSTAT_ADD(tcps_rcvackpack, nsegs);
10308 	KMOD_TCPSTAT_ADD(tcps_rcvackbyte, acked);
10309 	/*
10310 	 * If we just performed our first retransmit, and the ACK arrives
10311 	 * within our recovery window, then it was a mistake to do the
10312 	 * retransmit in the first place.  Recover our original cwnd and
10313 	 * ssthresh, and proceed to transmit where we left off.
10314 	 */
10315 	if ((tp->t_flags & TF_PREVVALID) &&
10316 	    ((tp->t_flags & TF_RCVD_TSTMP) == 0)) {
10317 		tp->t_flags &= ~TF_PREVVALID;
10318 		if (tp->t_rxtshift == 1 &&
10319 		    (int)(ticks - tp->t_badrxtwin) < 0)
10320 			rack_cong_signal(tp, CC_RTO_ERR, th->th_ack);
10321 	}
10322 	if (acked) {
10323 		/* assure we are not backed off */
10324 		tp->t_rxtshift = 0;
10325 		RACK_TCPT_RANGESET(tp->t_rxtcur, RACK_REXMTVAL(tp),
10326 			      rack_rto_min, rack_rto_max, rack->r_ctl.timer_slop);
10327 		rack->rc_tlp_in_progress = 0;
10328 		rack->r_ctl.rc_tlp_cnt_out = 0;
10329 		/*
10330 		 * If it is the RXT timer we want to
10331 		 * stop it, so we can restart a TLP.
10332 		 */
10333 		if (rack->r_ctl.rc_hpts_flags & PACE_TMR_RXT)
10334 			rack_timer_cancel(tp, rack, rack->r_ctl.rc_rcvtime, __LINE__);
10335 #ifdef NETFLIX_HTTP_LOGGING
10336 		tcp_http_check_for_comp(rack->rc_tp, th->th_ack);
10337 #endif
10338 	}
10339 	/*
10340 	 * If we have a timestamp reply, update smoothed round trip time. If
10341 	 * no timestamp is present but transmit timer is running and timed
10342 	 * sequence number was acked, update smoothed round trip time. Since
10343 	 * we now have an rtt measurement, cancel the timer backoff (cf.,
10344 	 * Phil Karn's retransmit alg.). Recompute the initial retransmit
10345 	 * timer.
10346 	 *
10347 	 * Some boxes send broken timestamp replies during the SYN+ACK
10348 	 * phase, ignore timestamps of 0 or we could calculate a huge RTT
10349 	 * and blow up the retransmit timer.
10350 	 */
10351 	/*
10352 	 * If all outstanding data is acked, stop retransmit timer and
10353 	 * remember to restart (more output or persist). If there is more
10354 	 * data to be acked, restart retransmit timer, using current
10355 	 * (possibly backed-off) value.
10356 	 */
10357 	if (acked == 0) {
10358 		if (ofia)
10359 			*ofia = ourfinisacked;
10360 		return (0);
10361 	}
10362 	if (IN_RECOVERY(tp->t_flags)) {
10363 		if (SEQ_LT(th->th_ack, tp->snd_recover) &&
10364 		    (SEQ_LT(th->th_ack, tp->snd_max))) {
10365 			tcp_rack_partialack(tp);
10366 		} else {
10367 			rack_post_recovery(tp, th->th_ack);
10368 			recovery = 1;
10369 		}
10370 	}
10371 	/*
10372 	 * Let the congestion control algorithm update congestion control
10373 	 * related information. This typically means increasing the
10374 	 * congestion window.
10375 	 */
10376 	rack_ack_received(tp, rack, th->th_ack, nsegs, CC_ACK, recovery);
10377 	SOCKBUF_LOCK(&so->so_snd);
10378 	acked_amount = min(acked, (int)sbavail(&so->so_snd));
10379 	tp->snd_wnd -= acked_amount;
10380 	mfree = sbcut_locked(&so->so_snd, acked_amount);
10381 	if ((sbused(&so->so_snd) == 0) &&
10382 	    (acked > acked_amount) &&
10383 	    (tp->t_state >= TCPS_FIN_WAIT_1) &&
10384 	    (tp->t_flags & TF_SENTFIN)) {
10385 		/*
10386 		 * We must be sure our fin
10387 		 * was sent and acked (we can be
10388 		 * in FIN_WAIT_1 without having
10389 		 * sent the fin).
10390 		 */
10391 		ourfinisacked = 1;
10392 	}
10393 	tp->snd_una = th->th_ack;
10394 	if (acked_amount && sbavail(&so->so_snd))
10395 		rack_adjust_sendmap(rack, &so->so_snd, tp->snd_una);
10396 	rack_log_wakeup(tp,rack, &so->so_snd, acked, 2);
10397 	/* NB: sowwakeup_locked() does an implicit unlock. */
10398 	sowwakeup_locked(so);
10399 	m_freem(mfree);
10400 	if (SEQ_GT(tp->snd_una, tp->snd_recover))
10401 		tp->snd_recover = tp->snd_una;
10402 
10403 	if (SEQ_LT(tp->snd_nxt, tp->snd_una)) {
10404 		tp->snd_nxt = tp->snd_una;
10405 	}
10406 	if (under_pacing &&
10407 	    (rack->use_fixed_rate == 0) &&
10408 	    (rack->in_probe_rtt == 0) &&
10409 	    rack->rc_gp_dyn_mul &&
10410 	    rack->rc_always_pace) {
10411 		/* Check if we are dragging bottom */
10412 		rack_check_bottom_drag(tp, rack, so, acked);
10413 	}
10414 	if (tp->snd_una == tp->snd_max) {
10415 		/* Nothing left outstanding */
10416 		tp->t_flags &= ~TF_PREVVALID;
10417 		rack->r_ctl.rc_went_idle_time = tcp_get_usecs(NULL);
10418 		rack->r_ctl.retran_during_recovery = 0;
10419 		rack->r_ctl.dsack_byte_cnt = 0;
10420 		if (rack->r_ctl.rc_went_idle_time == 0)
10421 			rack->r_ctl.rc_went_idle_time = 1;
10422 		rack_log_progress_event(rack, tp, 0, PROGRESS_CLEAR, __LINE__);
10423 		if (sbavail(&tp->t_inpcb->inp_socket->so_snd) == 0)
10424 			tp->t_acktime = 0;
10425 		rack_timer_cancel(tp, rack, rack->r_ctl.rc_rcvtime, __LINE__);
10426 		/* Set need output so persist might get set */
10427 		rack->r_wanted_output = 1;
10428 		sack_filter_clear(&rack->r_ctl.rack_sf, tp->snd_una);
10429 		if ((tp->t_state >= TCPS_FIN_WAIT_1) &&
10430 		    (sbavail(&so->so_snd) == 0) &&
10431 		    (tp->t_flags2 & TF2_DROP_AF_DATA)) {
10432 			/*
10433 			 * The socket was gone and the
10434 			 * peer sent data (now or in the past), time to
10435 			 * reset him.
10436 			 */
10437 			*ret_val = 1;
10438 			/* tcp_close will kill the inp pre-log the Reset */
10439 			tcp_log_end_status(tp, TCP_EI_STATUS_SERVER_RST);
10440 			tp = tcp_close(tp);
10441 			ctf_do_dropwithreset(m, tp, th, BANDLIM_UNLIMITED, tlen);
10442 			return (1);
10443 		}
10444 	}
10445 	if (ofia)
10446 		*ofia = ourfinisacked;
10447 	return (0);
10448 }
10449 
10450 static void
10451 rack_collapsed_window(struct tcp_rack *rack)
10452 {
10453 	/*
10454 	 * Now we must walk the
10455 	 * send map and divide the
10456 	 * ones left stranded. These
10457 	 * guys can't cause us to abort
10458 	 * the connection and are really
10459 	 * "unsent". However if a buggy
10460 	 * client actually did keep some
10461 	 * of the data i.e. collapsed the win
10462 	 * and refused to ack and then opened
10463 	 * the win and acked that data. We would
10464 	 * get into an ack war, the simplier
10465 	 * method then of just pretending we
10466 	 * did not send those segments something
10467 	 * won't work.
10468 	 */
10469 	struct rack_sendmap *rsm, *nrsm, fe, *insret;
10470 	tcp_seq max_seq;
10471 
10472 	max_seq = rack->rc_tp->snd_una + rack->rc_tp->snd_wnd;
10473 	memset(&fe, 0, sizeof(fe));
10474 	fe.r_start = max_seq;
10475 	/* Find the first seq past or at maxseq */
10476 	rsm = RB_FIND(rack_rb_tree_head, &rack->r_ctl.rc_mtree, &fe);
10477 	if (rsm == NULL) {
10478 		/* Nothing to do strange */
10479 		rack->rc_has_collapsed = 0;
10480 		return;
10481 	}
10482 	/*
10483 	 * Now do we need to split at
10484 	 * the collapse point?
10485 	 */
10486 	if (SEQ_GT(max_seq, rsm->r_start)) {
10487 		nrsm = rack_alloc_limit(rack, RACK_LIMIT_TYPE_SPLIT);
10488 		if (nrsm == NULL) {
10489 			/* We can't get a rsm, mark all? */
10490 			nrsm = rsm;
10491 			goto no_split;
10492 		}
10493 		/* Clone it */
10494 		rack_clone_rsm(rack, nrsm, rsm, max_seq);
10495 		insret = RB_INSERT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, nrsm);
10496 #ifdef INVARIANTS
10497 		if (insret != NULL) {
10498 			panic("Insert in rb tree of %p fails ret:%p rack:%p rsm:%p",
10499 			      nrsm, insret, rack, rsm);
10500 		}
10501 #endif
10502 		rack_log_map_chg(rack->rc_tp, rack, NULL, rsm, nrsm, MAP_SPLIT, max_seq, __LINE__);
10503 		if (rsm->r_in_tmap) {
10504 			TAILQ_INSERT_AFTER(&rack->r_ctl.rc_tmap, rsm, nrsm, r_tnext);
10505 			nrsm->r_in_tmap = 1;
10506 		}
10507 		/*
10508 		 * Set in the new RSM as the
10509 		 * collapsed starting point
10510 		 */
10511 		rsm = nrsm;
10512 	}
10513 no_split:
10514 	counter_u64_add(rack_collapsed_win, 1);
10515 	RB_FOREACH_FROM(nrsm, rack_rb_tree_head, rsm) {
10516 		nrsm->r_flags |= RACK_RWND_COLLAPSED;
10517 	}
10518 	rack->rc_has_collapsed = 1;
10519 }
10520 
10521 static void
10522 rack_un_collapse_window(struct tcp_rack *rack)
10523 {
10524 	struct rack_sendmap *rsm;
10525 
10526 	RB_FOREACH_REVERSE(rsm, rack_rb_tree_head, &rack->r_ctl.rc_mtree) {
10527 		if (rsm->r_flags & RACK_RWND_COLLAPSED)
10528 			rsm->r_flags &= ~RACK_RWND_COLLAPSED;
10529 		else
10530 			break;
10531 	}
10532 	rack->rc_has_collapsed = 0;
10533 }
10534 
10535 static void
10536 rack_handle_delayed_ack(struct tcpcb *tp, struct tcp_rack *rack,
10537 			int32_t tlen, int32_t tfo_syn)
10538 {
10539 	if (DELAY_ACK(tp, tlen) || tfo_syn) {
10540 		if (rack->rc_dack_mode &&
10541 		    (tlen > 500) &&
10542 		    (rack->rc_dack_toggle == 1)) {
10543 			goto no_delayed_ack;
10544 		}
10545 		rack_timer_cancel(tp, rack,
10546 				  rack->r_ctl.rc_rcvtime, __LINE__);
10547 		tp->t_flags |= TF_DELACK;
10548 	} else {
10549 no_delayed_ack:
10550 		rack->r_wanted_output = 1;
10551 		tp->t_flags |= TF_ACKNOW;
10552 		if (rack->rc_dack_mode) {
10553 			if (tp->t_flags & TF_DELACK)
10554 				rack->rc_dack_toggle = 1;
10555 			else
10556 				rack->rc_dack_toggle = 0;
10557 		}
10558 	}
10559 }
10560 
10561 static void
10562 rack_validate_fo_sendwin_up(struct tcpcb *tp, struct tcp_rack *rack)
10563 {
10564 	/*
10565 	 * If fast output is in progress, lets validate that
10566 	 * the new window did not shrink on us and make it
10567 	 * so fast output should end.
10568 	 */
10569 	if (rack->r_fast_output) {
10570 		uint32_t out;
10571 
10572 		/*
10573 		 * Calculate what we will send if left as is
10574 		 * and compare that to our send window.
10575 		 */
10576 		out = ctf_outstanding(tp);
10577 		if ((out + rack->r_ctl.fsb.left_to_send) > tp->snd_wnd) {
10578 			/* ok we have an issue */
10579 			if (out >= tp->snd_wnd) {
10580 				/* Turn off fast output the window is met or collapsed */
10581 				rack->r_fast_output = 0;
10582 			} else {
10583 				/* we have some room left */
10584 				rack->r_ctl.fsb.left_to_send = tp->snd_wnd - out;
10585 				if (rack->r_ctl.fsb.left_to_send < ctf_fixed_maxseg(tp)) {
10586 					/* If not at least 1 full segment never mind */
10587 					rack->r_fast_output = 0;
10588 				}
10589 			}
10590 		}
10591 	}
10592 }
10593 
10594 
10595 /*
10596  * Return value of 1, the TCB is unlocked and most
10597  * likely gone, return value of 0, the TCP is still
10598  * locked.
10599  */
10600 static int
10601 rack_process_data(struct mbuf *m, struct tcphdr *th, struct socket *so,
10602     struct tcpcb *tp, int32_t drop_hdrlen, int32_t tlen,
10603     uint32_t tiwin, int32_t thflags, int32_t nxt_pkt)
10604 {
10605 	/*
10606 	 * Update window information. Don't look at window if no ACK: TAC's
10607 	 * send garbage on first SYN.
10608 	 */
10609 	int32_t nsegs;
10610 	int32_t tfo_syn;
10611 	struct tcp_rack *rack;
10612 
10613 	rack = (struct tcp_rack *)tp->t_fb_ptr;
10614 	INP_WLOCK_ASSERT(tp->t_inpcb);
10615 	nsegs = max(1, m->m_pkthdr.lro_nsegs);
10616 	if ((thflags & TH_ACK) &&
10617 	    (SEQ_LT(tp->snd_wl1, th->th_seq) ||
10618 	    (tp->snd_wl1 == th->th_seq && (SEQ_LT(tp->snd_wl2, th->th_ack) ||
10619 	    (tp->snd_wl2 == th->th_ack && tiwin > tp->snd_wnd))))) {
10620 		/* keep track of pure window updates */
10621 		if (tlen == 0 &&
10622 		    tp->snd_wl2 == th->th_ack && tiwin > tp->snd_wnd)
10623 			KMOD_TCPSTAT_INC(tcps_rcvwinupd);
10624 		tp->snd_wnd = tiwin;
10625 		rack_validate_fo_sendwin_up(tp, rack);
10626 		tp->snd_wl1 = th->th_seq;
10627 		tp->snd_wl2 = th->th_ack;
10628 		if (tp->snd_wnd > tp->max_sndwnd)
10629 			tp->max_sndwnd = tp->snd_wnd;
10630 		rack->r_wanted_output = 1;
10631 	} else if (thflags & TH_ACK) {
10632 		if ((tp->snd_wl2 == th->th_ack) && (tiwin < tp->snd_wnd)) {
10633 			tp->snd_wnd = tiwin;
10634 			rack_validate_fo_sendwin_up(tp, rack);
10635 			tp->snd_wl1 = th->th_seq;
10636 			tp->snd_wl2 = th->th_ack;
10637 		}
10638 	}
10639 	if (tp->snd_wnd < ctf_outstanding(tp))
10640 		/* The peer collapsed the window */
10641 		rack_collapsed_window(rack);
10642 	else if (rack->rc_has_collapsed)
10643 		rack_un_collapse_window(rack);
10644 	/* Was persist timer active and now we have window space? */
10645 	if ((rack->rc_in_persist != 0) &&
10646 	    (tp->snd_wnd >= min((rack->r_ctl.rc_high_rwnd/2),
10647 				rack->r_ctl.rc_pace_min_segs))) {
10648 		rack_exit_persist(tp, rack, rack->r_ctl.rc_rcvtime);
10649 		tp->snd_nxt = tp->snd_max;
10650 		/* Make sure we output to start the timer */
10651 		rack->r_wanted_output = 1;
10652 	}
10653 	/* Do we enter persists? */
10654 	if ((rack->rc_in_persist == 0) &&
10655 	    (tp->snd_wnd < min((rack->r_ctl.rc_high_rwnd/2), rack->r_ctl.rc_pace_min_segs)) &&
10656 	    TCPS_HAVEESTABLISHED(tp->t_state) &&
10657 	    (tp->snd_max == tp->snd_una) &&
10658 	    sbavail(&tp->t_inpcb->inp_socket->so_snd) &&
10659 	    (sbavail(&tp->t_inpcb->inp_socket->so_snd) > tp->snd_wnd)) {
10660 		/*
10661 		 * Here the rwnd is less than
10662 		 * the pacing size, we are established,
10663 		 * nothing is outstanding, and there is
10664 		 * data to send. Enter persists.
10665 		 */
10666 		rack_enter_persist(tp, rack, rack->r_ctl.rc_rcvtime);
10667 	}
10668 	if (tp->t_flags2 & TF2_DROP_AF_DATA) {
10669 		m_freem(m);
10670 		return (0);
10671 	}
10672 	/*
10673 	 * don't process the URG bit, ignore them drag
10674 	 * along the up.
10675 	 */
10676 	tp->rcv_up = tp->rcv_nxt;
10677 	INP_WLOCK_ASSERT(tp->t_inpcb);
10678 
10679 	/*
10680 	 * Process the segment text, merging it into the TCP sequencing
10681 	 * queue, and arranging for acknowledgment of receipt if necessary.
10682 	 * This process logically involves adjusting tp->rcv_wnd as data is
10683 	 * presented to the user (this happens in tcp_usrreq.c, case
10684 	 * PRU_RCVD).  If a FIN has already been received on this connection
10685 	 * then we just ignore the text.
10686 	 */
10687 	tfo_syn = ((tp->t_state == TCPS_SYN_RECEIVED) &&
10688 		   IS_FASTOPEN(tp->t_flags));
10689 	if ((tlen || (thflags & TH_FIN) || (tfo_syn && tlen > 0)) &&
10690 	    TCPS_HAVERCVDFIN(tp->t_state) == 0) {
10691 		tcp_seq save_start = th->th_seq;
10692 		tcp_seq save_rnxt  = tp->rcv_nxt;
10693 		int     save_tlen  = tlen;
10694 
10695 		m_adj(m, drop_hdrlen);	/* delayed header drop */
10696 		/*
10697 		 * Insert segment which includes th into TCP reassembly
10698 		 * queue with control block tp.  Set thflags to whether
10699 		 * reassembly now includes a segment with FIN.  This handles
10700 		 * the common case inline (segment is the next to be
10701 		 * received on an established connection, and the queue is
10702 		 * empty), avoiding linkage into and removal from the queue
10703 		 * and repetition of various conversions. Set DELACK for
10704 		 * segments received in order, but ack immediately when
10705 		 * segments are out of order (so fast retransmit can work).
10706 		 */
10707 		if (th->th_seq == tp->rcv_nxt &&
10708 		    SEGQ_EMPTY(tp) &&
10709 		    (TCPS_HAVEESTABLISHED(tp->t_state) ||
10710 		    tfo_syn)) {
10711 #ifdef NETFLIX_SB_LIMITS
10712 			u_int mcnt, appended;
10713 
10714 			if (so->so_rcv.sb_shlim) {
10715 				mcnt = m_memcnt(m);
10716 				appended = 0;
10717 				if (counter_fo_get(so->so_rcv.sb_shlim, mcnt,
10718 				    CFO_NOSLEEP, NULL) == false) {
10719 					counter_u64_add(tcp_sb_shlim_fails, 1);
10720 					m_freem(m);
10721 					return (0);
10722 				}
10723 			}
10724 #endif
10725 			rack_handle_delayed_ack(tp, rack, tlen, tfo_syn);
10726 			tp->rcv_nxt += tlen;
10727 			if (tlen &&
10728 			    ((tp->t_flags2 & TF2_FBYTES_COMPLETE) == 0) &&
10729 			    (tp->t_fbyte_in == 0)) {
10730 				tp->t_fbyte_in = ticks;
10731 				if (tp->t_fbyte_in == 0)
10732 					tp->t_fbyte_in = 1;
10733 				if (tp->t_fbyte_out && tp->t_fbyte_in)
10734 					tp->t_flags2 |= TF2_FBYTES_COMPLETE;
10735 			}
10736 			thflags = th->th_flags & TH_FIN;
10737 			KMOD_TCPSTAT_ADD(tcps_rcvpack, nsegs);
10738 			KMOD_TCPSTAT_ADD(tcps_rcvbyte, tlen);
10739 			SOCKBUF_LOCK(&so->so_rcv);
10740 			if (so->so_rcv.sb_state & SBS_CANTRCVMORE) {
10741 				m_freem(m);
10742 			} else
10743 #ifdef NETFLIX_SB_LIMITS
10744 				appended =
10745 #endif
10746 					sbappendstream_locked(&so->so_rcv, m, 0);
10747 
10748 			rack_log_wakeup(tp,rack, &so->so_rcv, tlen, 1);
10749 			/* NB: sorwakeup_locked() does an implicit unlock. */
10750 			sorwakeup_locked(so);
10751 #ifdef NETFLIX_SB_LIMITS
10752 			if (so->so_rcv.sb_shlim && appended != mcnt)
10753 				counter_fo_release(so->so_rcv.sb_shlim,
10754 				    mcnt - appended);
10755 #endif
10756 		} else {
10757 			/*
10758 			 * XXX: Due to the header drop above "th" is
10759 			 * theoretically invalid by now.  Fortunately
10760 			 * m_adj() doesn't actually frees any mbufs when
10761 			 * trimming from the head.
10762 			 */
10763 			tcp_seq temp = save_start;
10764 
10765 			thflags = tcp_reass(tp, th, &temp, &tlen, m);
10766 			tp->t_flags |= TF_ACKNOW;
10767 			if (tp->t_flags & TF_WAKESOR) {
10768 				tp->t_flags &= ~TF_WAKESOR;
10769 				/* NB: sorwakeup_locked() does an implicit unlock. */
10770 				sorwakeup_locked(so);
10771 			}
10772 		}
10773 		if ((tp->t_flags & TF_SACK_PERMIT) &&
10774 		    (save_tlen > 0) &&
10775 		    TCPS_HAVEESTABLISHED(tp->t_state)) {
10776 			if ((tlen == 0) && (SEQ_LT(save_start, save_rnxt))) {
10777 				/*
10778 				 * DSACK actually handled in the fastpath
10779 				 * above.
10780 				 */
10781 				RACK_OPTS_INC(tcp_sack_path_1);
10782 				tcp_update_sack_list(tp, save_start,
10783 				    save_start + save_tlen);
10784 			} else if ((tlen > 0) && SEQ_GT(tp->rcv_nxt, save_rnxt)) {
10785 				if ((tp->rcv_numsacks >= 1) &&
10786 				    (tp->sackblks[0].end == save_start)) {
10787 					/*
10788 					 * Partial overlap, recorded at todrop
10789 					 * above.
10790 					 */
10791 					RACK_OPTS_INC(tcp_sack_path_2a);
10792 					tcp_update_sack_list(tp,
10793 					    tp->sackblks[0].start,
10794 					    tp->sackblks[0].end);
10795 				} else {
10796 					RACK_OPTS_INC(tcp_sack_path_2b);
10797 					tcp_update_dsack_list(tp, save_start,
10798 					    save_start + save_tlen);
10799 				}
10800 			} else if (tlen >= save_tlen) {
10801 				/* Update of sackblks. */
10802 				RACK_OPTS_INC(tcp_sack_path_3);
10803 				tcp_update_dsack_list(tp, save_start,
10804 				    save_start + save_tlen);
10805 			} else if (tlen > 0) {
10806 				RACK_OPTS_INC(tcp_sack_path_4);
10807 				tcp_update_dsack_list(tp, save_start,
10808 				    save_start + tlen);
10809 			}
10810 		}
10811 	} else {
10812 		m_freem(m);
10813 		thflags &= ~TH_FIN;
10814 	}
10815 
10816 	/*
10817 	 * If FIN is received ACK the FIN and let the user know that the
10818 	 * connection is closing.
10819 	 */
10820 	if (thflags & TH_FIN) {
10821 		if (TCPS_HAVERCVDFIN(tp->t_state) == 0) {
10822 			/* The socket upcall is handled by socantrcvmore. */
10823 			socantrcvmore(so);
10824 			/*
10825 			 * If connection is half-synchronized (ie NEEDSYN
10826 			 * flag on) then delay ACK, so it may be piggybacked
10827 			 * when SYN is sent. Otherwise, since we received a
10828 			 * FIN then no more input can be expected, send ACK
10829 			 * now.
10830 			 */
10831 			if (tp->t_flags & TF_NEEDSYN) {
10832 				rack_timer_cancel(tp, rack,
10833 				    rack->r_ctl.rc_rcvtime, __LINE__);
10834 				tp->t_flags |= TF_DELACK;
10835 			} else {
10836 				tp->t_flags |= TF_ACKNOW;
10837 			}
10838 			tp->rcv_nxt++;
10839 		}
10840 		switch (tp->t_state) {
10841 			/*
10842 			 * In SYN_RECEIVED and ESTABLISHED STATES enter the
10843 			 * CLOSE_WAIT state.
10844 			 */
10845 		case TCPS_SYN_RECEIVED:
10846 			tp->t_starttime = ticks;
10847 			/* FALLTHROUGH */
10848 		case TCPS_ESTABLISHED:
10849 			rack_timer_cancel(tp, rack,
10850 			    rack->r_ctl.rc_rcvtime, __LINE__);
10851 			tcp_state_change(tp, TCPS_CLOSE_WAIT);
10852 			break;
10853 
10854 			/*
10855 			 * If still in FIN_WAIT_1 STATE FIN has not been
10856 			 * acked so enter the CLOSING state.
10857 			 */
10858 		case TCPS_FIN_WAIT_1:
10859 			rack_timer_cancel(tp, rack,
10860 			    rack->r_ctl.rc_rcvtime, __LINE__);
10861 			tcp_state_change(tp, TCPS_CLOSING);
10862 			break;
10863 
10864 			/*
10865 			 * In FIN_WAIT_2 state enter the TIME_WAIT state,
10866 			 * starting the time-wait timer, turning off the
10867 			 * other standard timers.
10868 			 */
10869 		case TCPS_FIN_WAIT_2:
10870 			rack_timer_cancel(tp, rack,
10871 			    rack->r_ctl.rc_rcvtime, __LINE__);
10872 			tcp_twstart(tp);
10873 			return (1);
10874 		}
10875 	}
10876 	/*
10877 	 * Return any desired output.
10878 	 */
10879 	if ((tp->t_flags & TF_ACKNOW) ||
10880 	    (sbavail(&so->so_snd) > (tp->snd_max - tp->snd_una))) {
10881 		rack->r_wanted_output = 1;
10882 	}
10883 	INP_WLOCK_ASSERT(tp->t_inpcb);
10884 	return (0);
10885 }
10886 
10887 /*
10888  * Here nothing is really faster, its just that we
10889  * have broken out the fast-data path also just like
10890  * the fast-ack.
10891  */
10892 static int
10893 rack_do_fastnewdata(struct mbuf *m, struct tcphdr *th, struct socket *so,
10894     struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen,
10895     uint32_t tiwin, int32_t nxt_pkt, uint8_t iptos)
10896 {
10897 	int32_t nsegs;
10898 	int32_t newsize = 0;	/* automatic sockbuf scaling */
10899 	struct tcp_rack *rack;
10900 #ifdef NETFLIX_SB_LIMITS
10901 	u_int mcnt, appended;
10902 #endif
10903 #ifdef TCPDEBUG
10904 	/*
10905 	 * The size of tcp_saveipgen must be the size of the max ip header,
10906 	 * now IPv6.
10907 	 */
10908 	u_char tcp_saveipgen[IP6_HDR_LEN];
10909 	struct tcphdr tcp_savetcp;
10910 	short ostate = 0;
10911 
10912 #endif
10913 	/*
10914 	 * If last ACK falls within this segment's sequence numbers, record
10915 	 * the timestamp. NOTE that the test is modified according to the
10916 	 * latest proposal of the tcplw@cray.com list (Braden 1993/04/26).
10917 	 */
10918 	if (__predict_false(th->th_seq != tp->rcv_nxt)) {
10919 		return (0);
10920 	}
10921 	if (__predict_false(tp->snd_nxt != tp->snd_max)) {
10922 		return (0);
10923 	}
10924 	if (tiwin && tiwin != tp->snd_wnd) {
10925 		return (0);
10926 	}
10927 	if (__predict_false((tp->t_flags & (TF_NEEDSYN | TF_NEEDFIN)))) {
10928 		return (0);
10929 	}
10930 	if (__predict_false((to->to_flags & TOF_TS) &&
10931 	    (TSTMP_LT(to->to_tsval, tp->ts_recent)))) {
10932 		return (0);
10933 	}
10934 	if (__predict_false((th->th_ack != tp->snd_una))) {
10935 		return (0);
10936 	}
10937 	if (__predict_false(tlen > sbspace(&so->so_rcv))) {
10938 		return (0);
10939 	}
10940 	if ((to->to_flags & TOF_TS) != 0 &&
10941 	    SEQ_LEQ(th->th_seq, tp->last_ack_sent)) {
10942 		tp->ts_recent_age = tcp_ts_getticks();
10943 		tp->ts_recent = to->to_tsval;
10944 	}
10945 	rack = (struct tcp_rack *)tp->t_fb_ptr;
10946 	/*
10947 	 * This is a pure, in-sequence data packet with nothing on the
10948 	 * reassembly queue and we have enough buffer space to take it.
10949 	 */
10950 	nsegs = max(1, m->m_pkthdr.lro_nsegs);
10951 
10952 #ifdef NETFLIX_SB_LIMITS
10953 	if (so->so_rcv.sb_shlim) {
10954 		mcnt = m_memcnt(m);
10955 		appended = 0;
10956 		if (counter_fo_get(so->so_rcv.sb_shlim, mcnt,
10957 		    CFO_NOSLEEP, NULL) == false) {
10958 			counter_u64_add(tcp_sb_shlim_fails, 1);
10959 			m_freem(m);
10960 			return (1);
10961 		}
10962 	}
10963 #endif
10964 	/* Clean receiver SACK report if present */
10965 	if (tp->rcv_numsacks)
10966 		tcp_clean_sackreport(tp);
10967 	KMOD_TCPSTAT_INC(tcps_preddat);
10968 	tp->rcv_nxt += tlen;
10969 	if (tlen &&
10970 	    ((tp->t_flags2 & TF2_FBYTES_COMPLETE) == 0) &&
10971 	    (tp->t_fbyte_in == 0)) {
10972 		tp->t_fbyte_in = ticks;
10973 		if (tp->t_fbyte_in == 0)
10974 			tp->t_fbyte_in = 1;
10975 		if (tp->t_fbyte_out && tp->t_fbyte_in)
10976 			tp->t_flags2 |= TF2_FBYTES_COMPLETE;
10977 	}
10978 	/*
10979 	 * Pull snd_wl1 up to prevent seq wrap relative to th_seq.
10980 	 */
10981 	tp->snd_wl1 = th->th_seq;
10982 	/*
10983 	 * Pull rcv_up up to prevent seq wrap relative to rcv_nxt.
10984 	 */
10985 	tp->rcv_up = tp->rcv_nxt;
10986 	KMOD_TCPSTAT_ADD(tcps_rcvpack, nsegs);
10987 	KMOD_TCPSTAT_ADD(tcps_rcvbyte, tlen);
10988 #ifdef TCPDEBUG
10989 	if (so->so_options & SO_DEBUG)
10990 		tcp_trace(TA_INPUT, ostate, tp,
10991 		    (void *)tcp_saveipgen, &tcp_savetcp, 0);
10992 #endif
10993 	newsize = tcp_autorcvbuf(m, th, so, tp, tlen);
10994 
10995 	/* Add data to socket buffer. */
10996 	SOCKBUF_LOCK(&so->so_rcv);
10997 	if (so->so_rcv.sb_state & SBS_CANTRCVMORE) {
10998 		m_freem(m);
10999 	} else {
11000 		/*
11001 		 * Set new socket buffer size. Give up when limit is
11002 		 * reached.
11003 		 */
11004 		if (newsize)
11005 			if (!sbreserve_locked(&so->so_rcv,
11006 			    newsize, so, NULL))
11007 				so->so_rcv.sb_flags &= ~SB_AUTOSIZE;
11008 		m_adj(m, drop_hdrlen);	/* delayed header drop */
11009 #ifdef NETFLIX_SB_LIMITS
11010 		appended =
11011 #endif
11012 			sbappendstream_locked(&so->so_rcv, m, 0);
11013 		ctf_calc_rwin(so, tp);
11014 	}
11015 	rack_log_wakeup(tp,rack, &so->so_rcv, tlen, 1);
11016 	/* NB: sorwakeup_locked() does an implicit unlock. */
11017 	sorwakeup_locked(so);
11018 #ifdef NETFLIX_SB_LIMITS
11019 	if (so->so_rcv.sb_shlim && mcnt != appended)
11020 		counter_fo_release(so->so_rcv.sb_shlim, mcnt - appended);
11021 #endif
11022 	rack_handle_delayed_ack(tp, rack, tlen, 0);
11023 	if (tp->snd_una == tp->snd_max)
11024 		sack_filter_clear(&rack->r_ctl.rack_sf, tp->snd_una);
11025 	return (1);
11026 }
11027 
11028 /*
11029  * This subfunction is used to try to highly optimize the
11030  * fast path. We again allow window updates that are
11031  * in sequence to remain in the fast-path. We also add
11032  * in the __predict's to attempt to help the compiler.
11033  * Note that if we return a 0, then we can *not* process
11034  * it and the caller should push the packet into the
11035  * slow-path.
11036  */
11037 static int
11038 rack_fastack(struct mbuf *m, struct tcphdr *th, struct socket *so,
11039     struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen,
11040     uint32_t tiwin, int32_t nxt_pkt, uint32_t cts)
11041 {
11042 	int32_t acked;
11043 	int32_t nsegs;
11044 #ifdef TCPDEBUG
11045 	/*
11046 	 * The size of tcp_saveipgen must be the size of the max ip header,
11047 	 * now IPv6.
11048 	 */
11049 	u_char tcp_saveipgen[IP6_HDR_LEN];
11050 	struct tcphdr tcp_savetcp;
11051 	short ostate = 0;
11052 #endif
11053 	int32_t under_pacing = 0;
11054 	struct tcp_rack *rack;
11055 
11056 	if (__predict_false(SEQ_LEQ(th->th_ack, tp->snd_una))) {
11057 		/* Old ack, behind (or duplicate to) the last one rcv'd */
11058 		return (0);
11059 	}
11060 	if (__predict_false(SEQ_GT(th->th_ack, tp->snd_max))) {
11061 		/* Above what we have sent? */
11062 		return (0);
11063 	}
11064 	if (__predict_false(tp->snd_nxt != tp->snd_max)) {
11065 		/* We are retransmitting */
11066 		return (0);
11067 	}
11068 	if (__predict_false(tiwin == 0)) {
11069 		/* zero window */
11070 		return (0);
11071 	}
11072 	if (__predict_false(tp->t_flags & (TF_NEEDSYN | TF_NEEDFIN))) {
11073 		/* We need a SYN or a FIN, unlikely.. */
11074 		return (0);
11075 	}
11076 	if ((to->to_flags & TOF_TS) && __predict_false(TSTMP_LT(to->to_tsval, tp->ts_recent))) {
11077 		/* Timestamp is behind .. old ack with seq wrap? */
11078 		return (0);
11079 	}
11080 	if (__predict_false(IN_RECOVERY(tp->t_flags))) {
11081 		/* Still recovering */
11082 		return (0);
11083 	}
11084 	rack = (struct tcp_rack *)tp->t_fb_ptr;
11085 	if (rack->r_ctl.rc_sacked) {
11086 		/* We have sack holes on our scoreboard */
11087 		return (0);
11088 	}
11089 	/* Ok if we reach here, we can process a fast-ack */
11090 	if (rack->gp_ready &&
11091 	    (rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT)) {
11092 		under_pacing = 1;
11093 	}
11094 	nsegs = max(1, m->m_pkthdr.lro_nsegs);
11095 	rack_log_ack(tp, to, th, 0, 0);
11096 	/* Did the window get updated? */
11097 	if (tiwin != tp->snd_wnd) {
11098 		tp->snd_wnd = tiwin;
11099 		rack_validate_fo_sendwin_up(tp, rack);
11100 		tp->snd_wl1 = th->th_seq;
11101 		if (tp->snd_wnd > tp->max_sndwnd)
11102 			tp->max_sndwnd = tp->snd_wnd;
11103 	}
11104 	/* Do we exit persists? */
11105 	if ((rack->rc_in_persist != 0) &&
11106 	    (tp->snd_wnd >= min((rack->r_ctl.rc_high_rwnd/2),
11107 			       rack->r_ctl.rc_pace_min_segs))) {
11108 		rack_exit_persist(tp, rack, cts);
11109 	}
11110 	/* Do we enter persists? */
11111 	if ((rack->rc_in_persist == 0) &&
11112 	    (tp->snd_wnd < min((rack->r_ctl.rc_high_rwnd/2), rack->r_ctl.rc_pace_min_segs)) &&
11113 	    TCPS_HAVEESTABLISHED(tp->t_state) &&
11114 	    (tp->snd_max == tp->snd_una) &&
11115 	    sbavail(&tp->t_inpcb->inp_socket->so_snd) &&
11116 	    (sbavail(&tp->t_inpcb->inp_socket->so_snd) > tp->snd_wnd)) {
11117 		/*
11118 		 * Here the rwnd is less than
11119 		 * the pacing size, we are established,
11120 		 * nothing is outstanding, and there is
11121 		 * data to send. Enter persists.
11122 		 */
11123 		rack_enter_persist(tp, rack, rack->r_ctl.rc_rcvtime);
11124 	}
11125 	/*
11126 	 * If last ACK falls within this segment's sequence numbers, record
11127 	 * the timestamp. NOTE that the test is modified according to the
11128 	 * latest proposal of the tcplw@cray.com list (Braden 1993/04/26).
11129 	 */
11130 	if ((to->to_flags & TOF_TS) != 0 &&
11131 	    SEQ_LEQ(th->th_seq, tp->last_ack_sent)) {
11132 		tp->ts_recent_age = tcp_ts_getticks();
11133 		tp->ts_recent = to->to_tsval;
11134 	}
11135 	/*
11136 	 * This is a pure ack for outstanding data.
11137 	 */
11138 	KMOD_TCPSTAT_INC(tcps_predack);
11139 
11140 	/*
11141 	 * "bad retransmit" recovery.
11142 	 */
11143 	if ((tp->t_flags & TF_PREVVALID) &&
11144 	    ((tp->t_flags & TF_RCVD_TSTMP) == 0)) {
11145 		tp->t_flags &= ~TF_PREVVALID;
11146 		if (tp->t_rxtshift == 1 &&
11147 		    (int)(ticks - tp->t_badrxtwin) < 0)
11148 			rack_cong_signal(tp, CC_RTO_ERR, th->th_ack);
11149 	}
11150 	/*
11151 	 * Recalculate the transmit timer / rtt.
11152 	 *
11153 	 * Some boxes send broken timestamp replies during the SYN+ACK
11154 	 * phase, ignore timestamps of 0 or we could calculate a huge RTT
11155 	 * and blow up the retransmit timer.
11156 	 */
11157 	acked = BYTES_THIS_ACK(tp, th);
11158 
11159 #ifdef TCP_HHOOK
11160 	/* Run HHOOK_TCP_ESTABLISHED_IN helper hooks. */
11161 	hhook_run_tcp_est_in(tp, th, to);
11162 #endif
11163 	KMOD_TCPSTAT_ADD(tcps_rcvackpack, nsegs);
11164 	KMOD_TCPSTAT_ADD(tcps_rcvackbyte, acked);
11165 	if (acked) {
11166 		struct mbuf *mfree;
11167 
11168 		rack_ack_received(tp, rack, th->th_ack, nsegs, CC_ACK, 0);
11169 		SOCKBUF_LOCK(&so->so_snd);
11170 		mfree = sbcut_locked(&so->so_snd, acked);
11171 		tp->snd_una = th->th_ack;
11172 		/* Note we want to hold the sb lock through the sendmap adjust */
11173 		rack_adjust_sendmap(rack, &so->so_snd, tp->snd_una);
11174 		/* Wake up the socket if we have room to write more */
11175 		rack_log_wakeup(tp,rack, &so->so_snd, acked, 2);
11176 		sowwakeup_locked(so);
11177 		m_freem(mfree);
11178 		tp->t_rxtshift = 0;
11179 		RACK_TCPT_RANGESET(tp->t_rxtcur, RACK_REXMTVAL(tp),
11180 			      rack_rto_min, rack_rto_max, rack->r_ctl.timer_slop);
11181 		rack->rc_tlp_in_progress = 0;
11182 		rack->r_ctl.rc_tlp_cnt_out = 0;
11183 		/*
11184 		 * If it is the RXT timer we want to
11185 		 * stop it, so we can restart a TLP.
11186 		 */
11187 		if (rack->r_ctl.rc_hpts_flags & PACE_TMR_RXT)
11188 			rack_timer_cancel(tp, rack, rack->r_ctl.rc_rcvtime, __LINE__);
11189 #ifdef NETFLIX_HTTP_LOGGING
11190 		tcp_http_check_for_comp(rack->rc_tp, th->th_ack);
11191 #endif
11192 	}
11193 	/*
11194 	 * Let the congestion control algorithm update congestion control
11195 	 * related information. This typically means increasing the
11196 	 * congestion window.
11197 	 */
11198 	if (tp->snd_wnd < ctf_outstanding(tp)) {
11199 		/* The peer collapsed the window */
11200 		rack_collapsed_window(rack);
11201 	} else if (rack->rc_has_collapsed)
11202 		rack_un_collapse_window(rack);
11203 
11204 	/*
11205 	 * Pull snd_wl2 up to prevent seq wrap relative to th_ack.
11206 	 */
11207 	tp->snd_wl2 = th->th_ack;
11208 	tp->t_dupacks = 0;
11209 	m_freem(m);
11210 	/* ND6_HINT(tp);	 *//* Some progress has been made. */
11211 
11212 	/*
11213 	 * If all outstanding data are acked, stop retransmit timer,
11214 	 * otherwise restart timer using current (possibly backed-off)
11215 	 * value. If process is waiting for space, wakeup/selwakeup/signal.
11216 	 * If data are ready to send, let tcp_output decide between more
11217 	 * output or persist.
11218 	 */
11219 #ifdef TCPDEBUG
11220 	if (so->so_options & SO_DEBUG)
11221 		tcp_trace(TA_INPUT, ostate, tp,
11222 		    (void *)tcp_saveipgen,
11223 		    &tcp_savetcp, 0);
11224 #endif
11225 	if (under_pacing &&
11226 	    (rack->use_fixed_rate == 0) &&
11227 	    (rack->in_probe_rtt == 0) &&
11228 	    rack->rc_gp_dyn_mul &&
11229 	    rack->rc_always_pace) {
11230 		/* Check if we are dragging bottom */
11231 		rack_check_bottom_drag(tp, rack, so, acked);
11232 	}
11233 	if (tp->snd_una == tp->snd_max) {
11234 		tp->t_flags &= ~TF_PREVVALID;
11235 		rack->r_ctl.retran_during_recovery = 0;
11236 		rack->r_ctl.dsack_byte_cnt = 0;
11237 		rack->r_ctl.rc_went_idle_time = tcp_get_usecs(NULL);
11238 		if (rack->r_ctl.rc_went_idle_time == 0)
11239 			rack->r_ctl.rc_went_idle_time = 1;
11240 		rack_log_progress_event(rack, tp, 0, PROGRESS_CLEAR, __LINE__);
11241 		if (sbavail(&tp->t_inpcb->inp_socket->so_snd) == 0)
11242 			tp->t_acktime = 0;
11243 		rack_timer_cancel(tp, rack, rack->r_ctl.rc_rcvtime, __LINE__);
11244 	}
11245 	if (acked && rack->r_fast_output)
11246 		rack_gain_for_fastoutput(rack, tp, so, (uint32_t)acked);
11247 	if (sbavail(&so->so_snd)) {
11248 		rack->r_wanted_output = 1;
11249 	}
11250 	return (1);
11251 }
11252 
11253 /*
11254  * Return value of 1, the TCB is unlocked and most
11255  * likely gone, return value of 0, the TCP is still
11256  * locked.
11257  */
11258 static int
11259 rack_do_syn_sent(struct mbuf *m, struct tcphdr *th, struct socket *so,
11260     struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen,
11261     uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos)
11262 {
11263 	int32_t ret_val = 0;
11264 	int32_t todrop;
11265 	int32_t ourfinisacked = 0;
11266 	struct tcp_rack *rack;
11267 
11268 	ctf_calc_rwin(so, tp);
11269 	/*
11270 	 * If the state is SYN_SENT: if seg contains an ACK, but not for our
11271 	 * SYN, drop the input. if seg contains a RST, then drop the
11272 	 * connection. if seg does not contain SYN, then drop it. Otherwise
11273 	 * this is an acceptable SYN segment initialize tp->rcv_nxt and
11274 	 * tp->irs if seg contains ack then advance tp->snd_una if seg
11275 	 * contains an ECE and ECN support is enabled, the stream is ECN
11276 	 * capable. if SYN has been acked change to ESTABLISHED else
11277 	 * SYN_RCVD state arrange for segment to be acked (eventually)
11278 	 * continue processing rest of data/controls.
11279 	 */
11280 	if ((thflags & TH_ACK) &&
11281 	    (SEQ_LEQ(th->th_ack, tp->iss) ||
11282 	    SEQ_GT(th->th_ack, tp->snd_max))) {
11283 		tcp_log_end_status(tp, TCP_EI_STATUS_RST_IN_FRONT);
11284 		ctf_do_dropwithreset(m, tp, th, BANDLIM_RST_OPENPORT, tlen);
11285 		return (1);
11286 	}
11287 	if ((thflags & (TH_ACK | TH_RST)) == (TH_ACK | TH_RST)) {
11288 		TCP_PROBE5(connect__refused, NULL, tp,
11289 		    mtod(m, const char *), tp, th);
11290 		tp = tcp_drop(tp, ECONNREFUSED);
11291 		ctf_do_drop(m, tp);
11292 		return (1);
11293 	}
11294 	if (thflags & TH_RST) {
11295 		ctf_do_drop(m, tp);
11296 		return (1);
11297 	}
11298 	if (!(thflags & TH_SYN)) {
11299 		ctf_do_drop(m, tp);
11300 		return (1);
11301 	}
11302 	tp->irs = th->th_seq;
11303 	tcp_rcvseqinit(tp);
11304 	rack = (struct tcp_rack *)tp->t_fb_ptr;
11305 	if (thflags & TH_ACK) {
11306 		int tfo_partial = 0;
11307 
11308 		KMOD_TCPSTAT_INC(tcps_connects);
11309 		soisconnected(so);
11310 #ifdef MAC
11311 		mac_socketpeer_set_from_mbuf(m, so);
11312 #endif
11313 		/* Do window scaling on this connection? */
11314 		if ((tp->t_flags & (TF_RCVD_SCALE | TF_REQ_SCALE)) ==
11315 		    (TF_RCVD_SCALE | TF_REQ_SCALE)) {
11316 			tp->rcv_scale = tp->request_r_scale;
11317 		}
11318 		tp->rcv_adv += min(tp->rcv_wnd,
11319 		    TCP_MAXWIN << tp->rcv_scale);
11320 		/*
11321 		 * If not all the data that was sent in the TFO SYN
11322 		 * has been acked, resend the remainder right away.
11323 		 */
11324 		if (IS_FASTOPEN(tp->t_flags) &&
11325 		    (tp->snd_una != tp->snd_max)) {
11326 			tp->snd_nxt = th->th_ack;
11327 			tfo_partial = 1;
11328 		}
11329 		/*
11330 		 * If there's data, delay ACK; if there's also a FIN ACKNOW
11331 		 * will be turned on later.
11332 		 */
11333 		if (DELAY_ACK(tp, tlen) && tlen != 0 && !tfo_partial) {
11334 			rack_timer_cancel(tp, rack,
11335 					  rack->r_ctl.rc_rcvtime, __LINE__);
11336 			tp->t_flags |= TF_DELACK;
11337 		} else {
11338 			rack->r_wanted_output = 1;
11339 			tp->t_flags |= TF_ACKNOW;
11340 			rack->rc_dack_toggle = 0;
11341 		}
11342 		if (((thflags & (TH_CWR | TH_ECE)) == TH_ECE) &&
11343 		    (V_tcp_do_ecn == 1)) {
11344 			tp->t_flags2 |= TF2_ECN_PERMIT;
11345 			KMOD_TCPSTAT_INC(tcps_ecn_shs);
11346 		}
11347 		if (SEQ_GT(th->th_ack, tp->snd_una)) {
11348 			/*
11349 			 * We advance snd_una for the
11350 			 * fast open case. If th_ack is
11351 			 * acknowledging data beyond
11352 			 * snd_una we can't just call
11353 			 * ack-processing since the
11354 			 * data stream in our send-map
11355 			 * will start at snd_una + 1 (one
11356 			 * beyond the SYN). If its just
11357 			 * equal we don't need to do that
11358 			 * and there is no send_map.
11359 			 */
11360 			tp->snd_una++;
11361 		}
11362 		/*
11363 		 * Received <SYN,ACK> in SYN_SENT[*] state. Transitions:
11364 		 * SYN_SENT  --> ESTABLISHED SYN_SENT* --> FIN_WAIT_1
11365 		 */
11366 		tp->t_starttime = ticks;
11367 		if (tp->t_flags & TF_NEEDFIN) {
11368 			tcp_state_change(tp, TCPS_FIN_WAIT_1);
11369 			tp->t_flags &= ~TF_NEEDFIN;
11370 			thflags &= ~TH_SYN;
11371 		} else {
11372 			tcp_state_change(tp, TCPS_ESTABLISHED);
11373 			TCP_PROBE5(connect__established, NULL, tp,
11374 			    mtod(m, const char *), tp, th);
11375 			rack_cc_conn_init(tp);
11376 		}
11377 	} else {
11378 		/*
11379 		 * Received initial SYN in SYN-SENT[*] state => simultaneous
11380 		 * open.  If segment contains CC option and there is a
11381 		 * cached CC, apply TAO test. If it succeeds, connection is *
11382 		 * half-synchronized. Otherwise, do 3-way handshake:
11383 		 * SYN-SENT -> SYN-RECEIVED SYN-SENT* -> SYN-RECEIVED* If
11384 		 * there was no CC option, clear cached CC value.
11385 		 */
11386 		tp->t_flags |= (TF_ACKNOW | TF_NEEDSYN);
11387 		tcp_state_change(tp, TCPS_SYN_RECEIVED);
11388 	}
11389 	INP_WLOCK_ASSERT(tp->t_inpcb);
11390 	/*
11391 	 * Advance th->th_seq to correspond to first data byte. If data,
11392 	 * trim to stay within window, dropping FIN if necessary.
11393 	 */
11394 	th->th_seq++;
11395 	if (tlen > tp->rcv_wnd) {
11396 		todrop = tlen - tp->rcv_wnd;
11397 		m_adj(m, -todrop);
11398 		tlen = tp->rcv_wnd;
11399 		thflags &= ~TH_FIN;
11400 		KMOD_TCPSTAT_INC(tcps_rcvpackafterwin);
11401 		KMOD_TCPSTAT_ADD(tcps_rcvbyteafterwin, todrop);
11402 	}
11403 	tp->snd_wl1 = th->th_seq - 1;
11404 	tp->rcv_up = th->th_seq;
11405 	/*
11406 	 * Client side of transaction: already sent SYN and data. If the
11407 	 * remote host used T/TCP to validate the SYN, our data will be
11408 	 * ACK'd; if so, enter normal data segment processing in the middle
11409 	 * of step 5, ack processing. Otherwise, goto step 6.
11410 	 */
11411 	if (thflags & TH_ACK) {
11412 		/* For syn-sent we need to possibly update the rtt */
11413 		if ((to->to_flags & TOF_TS) != 0 && to->to_tsecr) {
11414 			uint32_t t, mcts;
11415 
11416 			mcts = tcp_ts_getticks();
11417 			t = (mcts - to->to_tsecr) * HPTS_USEC_IN_MSEC;
11418 			if (!tp->t_rttlow || tp->t_rttlow > t)
11419 				tp->t_rttlow = t;
11420 			rack_log_rtt_sample_calc(rack, t, (to->to_tsecr * 1000), (mcts * 1000), 4);
11421 			tcp_rack_xmit_timer(rack, t + 1, 1, t, 0, NULL, 2);
11422 			tcp_rack_xmit_timer_commit(rack, tp);
11423 		}
11424 		if (rack_process_ack(m, th, so, tp, to, tiwin, tlen, &ourfinisacked, thflags, &ret_val))
11425 			return (ret_val);
11426 		/* We may have changed to FIN_WAIT_1 above */
11427 		if (tp->t_state == TCPS_FIN_WAIT_1) {
11428 			/*
11429 			 * In FIN_WAIT_1 STATE in addition to the processing
11430 			 * for the ESTABLISHED state if our FIN is now
11431 			 * acknowledged then enter FIN_WAIT_2.
11432 			 */
11433 			if (ourfinisacked) {
11434 				/*
11435 				 * If we can't receive any more data, then
11436 				 * closing user can proceed. Starting the
11437 				 * timer is contrary to the specification,
11438 				 * but if we don't get a FIN we'll hang
11439 				 * forever.
11440 				 *
11441 				 * XXXjl: we should release the tp also, and
11442 				 * use a compressed state.
11443 				 */
11444 				if (so->so_rcv.sb_state & SBS_CANTRCVMORE) {
11445 					soisdisconnected(so);
11446 					tcp_timer_activate(tp, TT_2MSL,
11447 					    (tcp_fast_finwait2_recycle ?
11448 					    tcp_finwait2_timeout :
11449 					    TP_MAXIDLE(tp)));
11450 				}
11451 				tcp_state_change(tp, TCPS_FIN_WAIT_2);
11452 			}
11453 		}
11454 	}
11455 	return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
11456 	   tiwin, thflags, nxt_pkt));
11457 }
11458 
11459 /*
11460  * Return value of 1, the TCB is unlocked and most
11461  * likely gone, return value of 0, the TCP is still
11462  * locked.
11463  */
11464 static int
11465 rack_do_syn_recv(struct mbuf *m, struct tcphdr *th, struct socket *so,
11466     struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen,
11467     uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos)
11468 {
11469 	struct tcp_rack *rack;
11470 	int32_t ret_val = 0;
11471 	int32_t ourfinisacked = 0;
11472 
11473 	ctf_calc_rwin(so, tp);
11474 	if ((thflags & TH_ACK) &&
11475 	    (SEQ_LEQ(th->th_ack, tp->snd_una) ||
11476 	    SEQ_GT(th->th_ack, tp->snd_max))) {
11477 		tcp_log_end_status(tp, TCP_EI_STATUS_RST_IN_FRONT);
11478 		ctf_do_dropwithreset(m, tp, th, BANDLIM_RST_OPENPORT, tlen);
11479 		return (1);
11480 	}
11481 	rack = (struct tcp_rack *)tp->t_fb_ptr;
11482 	if (IS_FASTOPEN(tp->t_flags)) {
11483 		/*
11484 		 * When a TFO connection is in SYN_RECEIVED, the
11485 		 * only valid packets are the initial SYN, a
11486 		 * retransmit/copy of the initial SYN (possibly with
11487 		 * a subset of the original data), a valid ACK, a
11488 		 * FIN, or a RST.
11489 		 */
11490 		if ((thflags & (TH_SYN | TH_ACK)) == (TH_SYN | TH_ACK)) {
11491 			tcp_log_end_status(tp, TCP_EI_STATUS_RST_IN_FRONT);
11492 			ctf_do_dropwithreset(m, tp, th, BANDLIM_RST_OPENPORT, tlen);
11493 			return (1);
11494 		} else if (thflags & TH_SYN) {
11495 			/* non-initial SYN is ignored */
11496 			if ((rack->r_ctl.rc_hpts_flags & PACE_TMR_RXT) ||
11497 			    (rack->r_ctl.rc_hpts_flags & PACE_TMR_TLP) ||
11498 			    (rack->r_ctl.rc_hpts_flags & PACE_TMR_RACK)) {
11499 				ctf_do_drop(m, NULL);
11500 				return (0);
11501 			}
11502 		} else if (!(thflags & (TH_ACK | TH_FIN | TH_RST))) {
11503 			ctf_do_drop(m, NULL);
11504 			return (0);
11505 		}
11506 	}
11507 	if ((thflags & TH_RST) ||
11508 	    (tp->t_fin_is_rst && (thflags & TH_FIN)))
11509 		return (ctf_process_rst(m, th, so, tp));
11510 	/*
11511 	 * RFC 1323 PAWS: If we have a timestamp reply on this segment and
11512 	 * it's less than ts_recent, drop it.
11513 	 */
11514 	if ((to->to_flags & TOF_TS) != 0 && tp->ts_recent &&
11515 	    TSTMP_LT(to->to_tsval, tp->ts_recent)) {
11516 		if (ctf_ts_check(m, th, tp, tlen, thflags, &ret_val))
11517 			return (ret_val);
11518 	}
11519 	/*
11520 	 * In the SYN-RECEIVED state, validate that the packet belongs to
11521 	 * this connection before trimming the data to fit the receive
11522 	 * window.  Check the sequence number versus IRS since we know the
11523 	 * sequence numbers haven't wrapped.  This is a partial fix for the
11524 	 * "LAND" DoS attack.
11525 	 */
11526 	if (SEQ_LT(th->th_seq, tp->irs)) {
11527 		tcp_log_end_status(tp, TCP_EI_STATUS_RST_IN_FRONT);
11528 		ctf_do_dropwithreset(m, tp, th, BANDLIM_RST_OPENPORT, tlen);
11529 		return (1);
11530 	}
11531 	if (_ctf_drop_checks(to, m, th, tp, &tlen, &thflags, &drop_hdrlen, &ret_val,
11532 			      &rack->r_ctl.challenge_ack_ts,
11533 			      &rack->r_ctl.challenge_ack_cnt)) {
11534 		return (ret_val);
11535 	}
11536 	/*
11537 	 * If last ACK falls within this segment's sequence numbers, record
11538 	 * its timestamp. NOTE: 1) That the test incorporates suggestions
11539 	 * from the latest proposal of the tcplw@cray.com list (Braden
11540 	 * 1993/04/26). 2) That updating only on newer timestamps interferes
11541 	 * with our earlier PAWS tests, so this check should be solely
11542 	 * predicated on the sequence space of this segment. 3) That we
11543 	 * modify the segment boundary check to be Last.ACK.Sent <= SEG.SEQ
11544 	 * + SEG.Len  instead of RFC1323's Last.ACK.Sent < SEG.SEQ +
11545 	 * SEG.Len, This modified check allows us to overcome RFC1323's
11546 	 * limitations as described in Stevens TCP/IP Illustrated Vol. 2
11547 	 * p.869. In such cases, we can still calculate the RTT correctly
11548 	 * when RCV.NXT == Last.ACK.Sent.
11549 	 */
11550 	if ((to->to_flags & TOF_TS) != 0 &&
11551 	    SEQ_LEQ(th->th_seq, tp->last_ack_sent) &&
11552 	    SEQ_LEQ(tp->last_ack_sent, th->th_seq + tlen +
11553 	    ((thflags & (TH_SYN | TH_FIN)) != 0))) {
11554 		tp->ts_recent_age = tcp_ts_getticks();
11555 		tp->ts_recent = to->to_tsval;
11556 	}
11557 	tp->snd_wnd = tiwin;
11558 	rack_validate_fo_sendwin_up(tp, rack);
11559 	/*
11560 	 * If the ACK bit is off:  if in SYN-RECEIVED state or SENDSYN flag
11561 	 * is on (half-synchronized state), then queue data for later
11562 	 * processing; else drop segment and return.
11563 	 */
11564 	if ((thflags & TH_ACK) == 0) {
11565 		if (IS_FASTOPEN(tp->t_flags)) {
11566 			rack_cc_conn_init(tp);
11567 		}
11568 		return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
11569 		    tiwin, thflags, nxt_pkt));
11570 	}
11571 	KMOD_TCPSTAT_INC(tcps_connects);
11572 	soisconnected(so);
11573 	/* Do window scaling? */
11574 	if ((tp->t_flags & (TF_RCVD_SCALE | TF_REQ_SCALE)) ==
11575 	    (TF_RCVD_SCALE | TF_REQ_SCALE)) {
11576 		tp->rcv_scale = tp->request_r_scale;
11577 	}
11578 	/*
11579 	 * Make transitions: SYN-RECEIVED  -> ESTABLISHED SYN-RECEIVED* ->
11580 	 * FIN-WAIT-1
11581 	 */
11582 	tp->t_starttime = ticks;
11583 	if (IS_FASTOPEN(tp->t_flags) && tp->t_tfo_pending) {
11584 		tcp_fastopen_decrement_counter(tp->t_tfo_pending);
11585 		tp->t_tfo_pending = NULL;
11586 	}
11587 	if (tp->t_flags & TF_NEEDFIN) {
11588 		tcp_state_change(tp, TCPS_FIN_WAIT_1);
11589 		tp->t_flags &= ~TF_NEEDFIN;
11590 	} else {
11591 		tcp_state_change(tp, TCPS_ESTABLISHED);
11592 		TCP_PROBE5(accept__established, NULL, tp,
11593 		    mtod(m, const char *), tp, th);
11594 		/*
11595 		 * TFO connections call cc_conn_init() during SYN
11596 		 * processing.  Calling it again here for such connections
11597 		 * is not harmless as it would undo the snd_cwnd reduction
11598 		 * that occurs when a TFO SYN|ACK is retransmitted.
11599 		 */
11600 		if (!IS_FASTOPEN(tp->t_flags))
11601 			rack_cc_conn_init(tp);
11602 	}
11603 	/*
11604 	 * Account for the ACK of our SYN prior to
11605 	 * regular ACK processing below, except for
11606 	 * simultaneous SYN, which is handled later.
11607 	 */
11608 	if (SEQ_GT(th->th_ack, tp->snd_una) && !(tp->t_flags & TF_NEEDSYN))
11609 		tp->snd_una++;
11610 	/*
11611 	 * If segment contains data or ACK, will call tcp_reass() later; if
11612 	 * not, do so now to pass queued data to user.
11613 	 */
11614 	if (tlen == 0 && (thflags & TH_FIN) == 0) {
11615 		(void) tcp_reass(tp, (struct tcphdr *)0, NULL, 0,
11616 		    (struct mbuf *)0);
11617 		if (tp->t_flags & TF_WAKESOR) {
11618 			tp->t_flags &= ~TF_WAKESOR;
11619 			/* NB: sorwakeup_locked() does an implicit unlock. */
11620 			sorwakeup_locked(so);
11621 		}
11622 	}
11623 	tp->snd_wl1 = th->th_seq - 1;
11624 	/* For syn-recv we need to possibly update the rtt */
11625 	if ((to->to_flags & TOF_TS) != 0 && to->to_tsecr) {
11626 		uint32_t t, mcts;
11627 
11628 		mcts = tcp_ts_getticks();
11629 		t = (mcts - to->to_tsecr) * HPTS_USEC_IN_MSEC;
11630 		if (!tp->t_rttlow || tp->t_rttlow > t)
11631 			tp->t_rttlow = t;
11632 		rack_log_rtt_sample_calc(rack, t, (to->to_tsecr * 1000), (mcts * 1000), 5);
11633 		tcp_rack_xmit_timer(rack, t + 1, 1, t, 0, NULL, 2);
11634 		tcp_rack_xmit_timer_commit(rack, tp);
11635 	}
11636 	if (rack_process_ack(m, th, so, tp, to, tiwin, tlen, &ourfinisacked, thflags, &ret_val)) {
11637 		return (ret_val);
11638 	}
11639 	if (tp->t_state == TCPS_FIN_WAIT_1) {
11640 		/* We could have went to FIN_WAIT_1 (or EST) above */
11641 		/*
11642 		 * In FIN_WAIT_1 STATE in addition to the processing for the
11643 		 * ESTABLISHED state if our FIN is now acknowledged then
11644 		 * enter FIN_WAIT_2.
11645 		 */
11646 		if (ourfinisacked) {
11647 			/*
11648 			 * If we can't receive any more data, then closing
11649 			 * user can proceed. Starting the timer is contrary
11650 			 * to the specification, but if we don't get a FIN
11651 			 * we'll hang forever.
11652 			 *
11653 			 * XXXjl: we should release the tp also, and use a
11654 			 * compressed state.
11655 			 */
11656 			if (so->so_rcv.sb_state & SBS_CANTRCVMORE) {
11657 				soisdisconnected(so);
11658 				tcp_timer_activate(tp, TT_2MSL,
11659 				    (tcp_fast_finwait2_recycle ?
11660 				    tcp_finwait2_timeout :
11661 				    TP_MAXIDLE(tp)));
11662 			}
11663 			tcp_state_change(tp, TCPS_FIN_WAIT_2);
11664 		}
11665 	}
11666 	return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
11667 	    tiwin, thflags, nxt_pkt));
11668 }
11669 
11670 /*
11671  * Return value of 1, the TCB is unlocked and most
11672  * likely gone, return value of 0, the TCP is still
11673  * locked.
11674  */
11675 static int
11676 rack_do_established(struct mbuf *m, struct tcphdr *th, struct socket *so,
11677     struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen,
11678     uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos)
11679 {
11680 	int32_t ret_val = 0;
11681 	struct tcp_rack *rack;
11682 
11683 	/*
11684 	 * Header prediction: check for the two common cases of a
11685 	 * uni-directional data xfer.  If the packet has no control flags,
11686 	 * is in-sequence, the window didn't change and we're not
11687 	 * retransmitting, it's a candidate.  If the length is zero and the
11688 	 * ack moved forward, we're the sender side of the xfer.  Just free
11689 	 * the data acked & wake any higher level process that was blocked
11690 	 * waiting for space.  If the length is non-zero and the ack didn't
11691 	 * move, we're the receiver side.  If we're getting packets in-order
11692 	 * (the reassembly queue is empty), add the data toc The socket
11693 	 * buffer and note that we need a delayed ack. Make sure that the
11694 	 * hidden state-flags are also off. Since we check for
11695 	 * TCPS_ESTABLISHED first, it can only be TH_NEEDSYN.
11696 	 */
11697 	rack = (struct tcp_rack *)tp->t_fb_ptr;
11698 	if (__predict_true(((to->to_flags & TOF_SACK) == 0)) &&
11699 	    __predict_true((thflags & (TH_SYN | TH_FIN | TH_RST | TH_ACK)) == TH_ACK) &&
11700 	    __predict_true(SEGQ_EMPTY(tp)) &&
11701 	    __predict_true(th->th_seq == tp->rcv_nxt)) {
11702 		if (tlen == 0) {
11703 			if (rack_fastack(m, th, so, tp, to, drop_hdrlen, tlen,
11704 			    tiwin, nxt_pkt, rack->r_ctl.rc_rcvtime)) {
11705 				return (0);
11706 			}
11707 		} else {
11708 			if (rack_do_fastnewdata(m, th, so, tp, to, drop_hdrlen, tlen,
11709 			    tiwin, nxt_pkt, iptos)) {
11710 				return (0);
11711 			}
11712 		}
11713 	}
11714 	ctf_calc_rwin(so, tp);
11715 
11716 	if ((thflags & TH_RST) ||
11717 	    (tp->t_fin_is_rst && (thflags & TH_FIN)))
11718 		return (ctf_process_rst(m, th, so, tp));
11719 
11720 	/*
11721 	 * RFC5961 Section 4.2 Send challenge ACK for any SYN in
11722 	 * synchronized state.
11723 	 */
11724 	if (thflags & TH_SYN) {
11725 		ctf_challenge_ack(m, th, tp, &ret_val);
11726 		return (ret_val);
11727 	}
11728 	/*
11729 	 * RFC 1323 PAWS: If we have a timestamp reply on this segment and
11730 	 * it's less than ts_recent, drop it.
11731 	 */
11732 	if ((to->to_flags & TOF_TS) != 0 && tp->ts_recent &&
11733 	    TSTMP_LT(to->to_tsval, tp->ts_recent)) {
11734 		if (ctf_ts_check(m, th, tp, tlen, thflags, &ret_val))
11735 			return (ret_val);
11736 	}
11737 	if (_ctf_drop_checks(to, m, th, tp, &tlen, &thflags, &drop_hdrlen, &ret_val,
11738 			      &rack->r_ctl.challenge_ack_ts,
11739 			      &rack->r_ctl.challenge_ack_cnt)) {
11740 		return (ret_val);
11741 	}
11742 	/*
11743 	 * If last ACK falls within this segment's sequence numbers, record
11744 	 * its timestamp. NOTE: 1) That the test incorporates suggestions
11745 	 * from the latest proposal of the tcplw@cray.com list (Braden
11746 	 * 1993/04/26). 2) That updating only on newer timestamps interferes
11747 	 * with our earlier PAWS tests, so this check should be solely
11748 	 * predicated on the sequence space of this segment. 3) That we
11749 	 * modify the segment boundary check to be Last.ACK.Sent <= SEG.SEQ
11750 	 * + SEG.Len  instead of RFC1323's Last.ACK.Sent < SEG.SEQ +
11751 	 * SEG.Len, This modified check allows us to overcome RFC1323's
11752 	 * limitations as described in Stevens TCP/IP Illustrated Vol. 2
11753 	 * p.869. In such cases, we can still calculate the RTT correctly
11754 	 * when RCV.NXT == Last.ACK.Sent.
11755 	 */
11756 	if ((to->to_flags & TOF_TS) != 0 &&
11757 	    SEQ_LEQ(th->th_seq, tp->last_ack_sent) &&
11758 	    SEQ_LEQ(tp->last_ack_sent, th->th_seq + tlen +
11759 	    ((thflags & (TH_SYN | TH_FIN)) != 0))) {
11760 		tp->ts_recent_age = tcp_ts_getticks();
11761 		tp->ts_recent = to->to_tsval;
11762 	}
11763 	/*
11764 	 * If the ACK bit is off:  if in SYN-RECEIVED state or SENDSYN flag
11765 	 * is on (half-synchronized state), then queue data for later
11766 	 * processing; else drop segment and return.
11767 	 */
11768 	if ((thflags & TH_ACK) == 0) {
11769 		if (tp->t_flags & TF_NEEDSYN) {
11770 			return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
11771 			    tiwin, thflags, nxt_pkt));
11772 
11773 		} else if (tp->t_flags & TF_ACKNOW) {
11774 			ctf_do_dropafterack(m, tp, th, thflags, tlen, &ret_val);
11775 			((struct tcp_rack *)tp->t_fb_ptr)->r_wanted_output = 1;
11776 			return (ret_val);
11777 		} else {
11778 			ctf_do_drop(m, NULL);
11779 			return (0);
11780 		}
11781 	}
11782 	/*
11783 	 * Ack processing.
11784 	 */
11785 	if (rack_process_ack(m, th, so, tp, to, tiwin, tlen, NULL, thflags, &ret_val)) {
11786 		return (ret_val);
11787 	}
11788 	if (sbavail(&so->so_snd)) {
11789 		if (ctf_progress_timeout_check(tp, true)) {
11790 			rack_log_progress_event(rack, tp, tick, PROGRESS_DROP, __LINE__);
11791 			tcp_set_inp_to_drop(tp->t_inpcb, ETIMEDOUT);
11792 			ctf_do_dropwithreset(m, tp, th, BANDLIM_RST_OPENPORT, tlen);
11793 			return (1);
11794 		}
11795 	}
11796 	/* State changes only happen in rack_process_data() */
11797 	return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
11798 	    tiwin, thflags, nxt_pkt));
11799 }
11800 
11801 /*
11802  * Return value of 1, the TCB is unlocked and most
11803  * likely gone, return value of 0, the TCP is still
11804  * locked.
11805  */
11806 static int
11807 rack_do_close_wait(struct mbuf *m, struct tcphdr *th, struct socket *so,
11808     struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen,
11809     uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos)
11810 {
11811 	int32_t ret_val = 0;
11812 	struct tcp_rack *rack;
11813 
11814 	rack = (struct tcp_rack *)tp->t_fb_ptr;
11815 	ctf_calc_rwin(so, tp);
11816 	if ((thflags & TH_RST) ||
11817 	    (tp->t_fin_is_rst && (thflags & TH_FIN)))
11818 		return (ctf_process_rst(m, th, so, tp));
11819 	/*
11820 	 * RFC5961 Section 4.2 Send challenge ACK for any SYN in
11821 	 * synchronized state.
11822 	 */
11823 	if (thflags & TH_SYN) {
11824 		ctf_challenge_ack(m, th, tp, &ret_val);
11825 		return (ret_val);
11826 	}
11827 	/*
11828 	 * RFC 1323 PAWS: If we have a timestamp reply on this segment and
11829 	 * it's less than ts_recent, drop it.
11830 	 */
11831 	if ((to->to_flags & TOF_TS) != 0 && tp->ts_recent &&
11832 	    TSTMP_LT(to->to_tsval, tp->ts_recent)) {
11833 		if (ctf_ts_check(m, th, tp, tlen, thflags, &ret_val))
11834 			return (ret_val);
11835 	}
11836 	if (_ctf_drop_checks(to, m, th, tp, &tlen, &thflags, &drop_hdrlen, &ret_val,
11837 			      &rack->r_ctl.challenge_ack_ts,
11838 			      &rack->r_ctl.challenge_ack_cnt)) {
11839 		return (ret_val);
11840 	}
11841 	/*
11842 	 * If last ACK falls within this segment's sequence numbers, record
11843 	 * its timestamp. NOTE: 1) That the test incorporates suggestions
11844 	 * from the latest proposal of the tcplw@cray.com list (Braden
11845 	 * 1993/04/26). 2) That updating only on newer timestamps interferes
11846 	 * with our earlier PAWS tests, so this check should be solely
11847 	 * predicated on the sequence space of this segment. 3) That we
11848 	 * modify the segment boundary check to be Last.ACK.Sent <= SEG.SEQ
11849 	 * + SEG.Len  instead of RFC1323's Last.ACK.Sent < SEG.SEQ +
11850 	 * SEG.Len, This modified check allows us to overcome RFC1323's
11851 	 * limitations as described in Stevens TCP/IP Illustrated Vol. 2
11852 	 * p.869. In such cases, we can still calculate the RTT correctly
11853 	 * when RCV.NXT == Last.ACK.Sent.
11854 	 */
11855 	if ((to->to_flags & TOF_TS) != 0 &&
11856 	    SEQ_LEQ(th->th_seq, tp->last_ack_sent) &&
11857 	    SEQ_LEQ(tp->last_ack_sent, th->th_seq + tlen +
11858 	    ((thflags & (TH_SYN | TH_FIN)) != 0))) {
11859 		tp->ts_recent_age = tcp_ts_getticks();
11860 		tp->ts_recent = to->to_tsval;
11861 	}
11862 	/*
11863 	 * If the ACK bit is off:  if in SYN-RECEIVED state or SENDSYN flag
11864 	 * is on (half-synchronized state), then queue data for later
11865 	 * processing; else drop segment and return.
11866 	 */
11867 	if ((thflags & TH_ACK) == 0) {
11868 		if (tp->t_flags & TF_NEEDSYN) {
11869 			return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
11870 			    tiwin, thflags, nxt_pkt));
11871 
11872 		} else if (tp->t_flags & TF_ACKNOW) {
11873 			ctf_do_dropafterack(m, tp, th, thflags, tlen, &ret_val);
11874 			((struct tcp_rack *)tp->t_fb_ptr)->r_wanted_output = 1;
11875 			return (ret_val);
11876 		} else {
11877 			ctf_do_drop(m, NULL);
11878 			return (0);
11879 		}
11880 	}
11881 	/*
11882 	 * Ack processing.
11883 	 */
11884 	if (rack_process_ack(m, th, so, tp, to, tiwin, tlen, NULL, thflags, &ret_val)) {
11885 		return (ret_val);
11886 	}
11887 	if (sbavail(&so->so_snd)) {
11888 		if (ctf_progress_timeout_check(tp, true)) {
11889 			rack_log_progress_event((struct tcp_rack *)tp->t_fb_ptr,
11890 						tp, tick, PROGRESS_DROP, __LINE__);
11891 			tcp_set_inp_to_drop(tp->t_inpcb, ETIMEDOUT);
11892 			ctf_do_dropwithreset(m, tp, th, BANDLIM_RST_OPENPORT, tlen);
11893 			return (1);
11894 		}
11895 	}
11896 	return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
11897 	    tiwin, thflags, nxt_pkt));
11898 }
11899 
11900 static int
11901 rack_check_data_after_close(struct mbuf *m,
11902     struct tcpcb *tp, int32_t *tlen, struct tcphdr *th, struct socket *so)
11903 {
11904 	struct tcp_rack *rack;
11905 
11906 	rack = (struct tcp_rack *)tp->t_fb_ptr;
11907 	if (rack->rc_allow_data_af_clo == 0) {
11908 	close_now:
11909 		tcp_log_end_status(tp, TCP_EI_STATUS_DATA_A_CLOSE);
11910 		/* tcp_close will kill the inp pre-log the Reset */
11911 		tcp_log_end_status(tp, TCP_EI_STATUS_SERVER_RST);
11912 		tp = tcp_close(tp);
11913 		KMOD_TCPSTAT_INC(tcps_rcvafterclose);
11914 		ctf_do_dropwithreset(m, tp, th, BANDLIM_UNLIMITED, (*tlen));
11915 		return (1);
11916 	}
11917 	if (sbavail(&so->so_snd) == 0)
11918 		goto close_now;
11919 	/* Ok we allow data that is ignored and a followup reset */
11920 	tcp_log_end_status(tp, TCP_EI_STATUS_DATA_A_CLOSE);
11921 	tp->rcv_nxt = th->th_seq + *tlen;
11922 	tp->t_flags2 |= TF2_DROP_AF_DATA;
11923 	rack->r_wanted_output = 1;
11924 	*tlen = 0;
11925 	return (0);
11926 }
11927 
11928 /*
11929  * Return value of 1, the TCB is unlocked and most
11930  * likely gone, return value of 0, the TCP is still
11931  * locked.
11932  */
11933 static int
11934 rack_do_fin_wait_1(struct mbuf *m, struct tcphdr *th, struct socket *so,
11935     struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen,
11936     uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos)
11937 {
11938 	int32_t ret_val = 0;
11939 	int32_t ourfinisacked = 0;
11940 	struct tcp_rack *rack;
11941 
11942 	rack = (struct tcp_rack *)tp->t_fb_ptr;
11943 	ctf_calc_rwin(so, tp);
11944 
11945 	if ((thflags & TH_RST) ||
11946 	    (tp->t_fin_is_rst && (thflags & TH_FIN)))
11947 		return (ctf_process_rst(m, th, so, tp));
11948 	/*
11949 	 * RFC5961 Section 4.2 Send challenge ACK for any SYN in
11950 	 * synchronized state.
11951 	 */
11952 	if (thflags & TH_SYN) {
11953 		ctf_challenge_ack(m, th, tp, &ret_val);
11954 		return (ret_val);
11955 	}
11956 	/*
11957 	 * RFC 1323 PAWS: If we have a timestamp reply on this segment and
11958 	 * it's less than ts_recent, drop it.
11959 	 */
11960 	if ((to->to_flags & TOF_TS) != 0 && tp->ts_recent &&
11961 	    TSTMP_LT(to->to_tsval, tp->ts_recent)) {
11962 		if (ctf_ts_check(m, th, tp, tlen, thflags, &ret_val))
11963 			return (ret_val);
11964 	}
11965 	if (_ctf_drop_checks(to, m, th, tp, &tlen, &thflags, &drop_hdrlen, &ret_val,
11966 			      &rack->r_ctl.challenge_ack_ts,
11967 			      &rack->r_ctl.challenge_ack_cnt)) {
11968 		return (ret_val);
11969 	}
11970 	/*
11971 	 * If new data are received on a connection after the user processes
11972 	 * are gone, then RST the other end.
11973 	 */
11974 	if ((so->so_state & SS_NOFDREF) && tlen) {
11975 		if (rack_check_data_after_close(m, tp, &tlen, th, so))
11976 			return (1);
11977 	}
11978 	/*
11979 	 * If last ACK falls within this segment's sequence numbers, record
11980 	 * its timestamp. NOTE: 1) That the test incorporates suggestions
11981 	 * from the latest proposal of the tcplw@cray.com list (Braden
11982 	 * 1993/04/26). 2) That updating only on newer timestamps interferes
11983 	 * with our earlier PAWS tests, so this check should be solely
11984 	 * predicated on the sequence space of this segment. 3) That we
11985 	 * modify the segment boundary check to be Last.ACK.Sent <= SEG.SEQ
11986 	 * + SEG.Len  instead of RFC1323's Last.ACK.Sent < SEG.SEQ +
11987 	 * SEG.Len, This modified check allows us to overcome RFC1323's
11988 	 * limitations as described in Stevens TCP/IP Illustrated Vol. 2
11989 	 * p.869. In such cases, we can still calculate the RTT correctly
11990 	 * when RCV.NXT == Last.ACK.Sent.
11991 	 */
11992 	if ((to->to_flags & TOF_TS) != 0 &&
11993 	    SEQ_LEQ(th->th_seq, tp->last_ack_sent) &&
11994 	    SEQ_LEQ(tp->last_ack_sent, th->th_seq + tlen +
11995 	    ((thflags & (TH_SYN | TH_FIN)) != 0))) {
11996 		tp->ts_recent_age = tcp_ts_getticks();
11997 		tp->ts_recent = to->to_tsval;
11998 	}
11999 	/*
12000 	 * If the ACK bit is off:  if in SYN-RECEIVED state or SENDSYN flag
12001 	 * is on (half-synchronized state), then queue data for later
12002 	 * processing; else drop segment and return.
12003 	 */
12004 	if ((thflags & TH_ACK) == 0) {
12005 		if (tp->t_flags & TF_NEEDSYN) {
12006 			return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
12007 			    tiwin, thflags, nxt_pkt));
12008 		} else if (tp->t_flags & TF_ACKNOW) {
12009 			ctf_do_dropafterack(m, tp, th, thflags, tlen, &ret_val);
12010 			((struct tcp_rack *)tp->t_fb_ptr)->r_wanted_output = 1;
12011 			return (ret_val);
12012 		} else {
12013 			ctf_do_drop(m, NULL);
12014 			return (0);
12015 		}
12016 	}
12017 	/*
12018 	 * Ack processing.
12019 	 */
12020 	if (rack_process_ack(m, th, so, tp, to, tiwin, tlen, &ourfinisacked, thflags, &ret_val)) {
12021 		return (ret_val);
12022 	}
12023 	if (ourfinisacked) {
12024 		/*
12025 		 * If we can't receive any more data, then closing user can
12026 		 * proceed. Starting the timer is contrary to the
12027 		 * specification, but if we don't get a FIN we'll hang
12028 		 * forever.
12029 		 *
12030 		 * XXXjl: we should release the tp also, and use a
12031 		 * compressed state.
12032 		 */
12033 		if (so->so_rcv.sb_state & SBS_CANTRCVMORE) {
12034 			soisdisconnected(so);
12035 			tcp_timer_activate(tp, TT_2MSL,
12036 			    (tcp_fast_finwait2_recycle ?
12037 			    tcp_finwait2_timeout :
12038 			    TP_MAXIDLE(tp)));
12039 		}
12040 		tcp_state_change(tp, TCPS_FIN_WAIT_2);
12041 	}
12042 	if (sbavail(&so->so_snd)) {
12043 		if (ctf_progress_timeout_check(tp, true)) {
12044 			rack_log_progress_event((struct tcp_rack *)tp->t_fb_ptr,
12045 						tp, tick, PROGRESS_DROP, __LINE__);
12046 			tcp_set_inp_to_drop(tp->t_inpcb, ETIMEDOUT);
12047 			ctf_do_dropwithreset(m, tp, th, BANDLIM_RST_OPENPORT, tlen);
12048 			return (1);
12049 		}
12050 	}
12051 	return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
12052 	    tiwin, thflags, nxt_pkt));
12053 }
12054 
12055 /*
12056  * Return value of 1, the TCB is unlocked and most
12057  * likely gone, return value of 0, the TCP is still
12058  * locked.
12059  */
12060 static int
12061 rack_do_closing(struct mbuf *m, struct tcphdr *th, struct socket *so,
12062     struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen,
12063     uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos)
12064 {
12065 	int32_t ret_val = 0;
12066 	int32_t ourfinisacked = 0;
12067 	struct tcp_rack *rack;
12068 
12069 	rack = (struct tcp_rack *)tp->t_fb_ptr;
12070 	ctf_calc_rwin(so, tp);
12071 
12072 	if ((thflags & TH_RST) ||
12073 	    (tp->t_fin_is_rst && (thflags & TH_FIN)))
12074 		return (ctf_process_rst(m, th, so, tp));
12075 	/*
12076 	 * RFC5961 Section 4.2 Send challenge ACK for any SYN in
12077 	 * synchronized state.
12078 	 */
12079 	if (thflags & TH_SYN) {
12080 		ctf_challenge_ack(m, th, tp, &ret_val);
12081 		return (ret_val);
12082 	}
12083 	/*
12084 	 * RFC 1323 PAWS: If we have a timestamp reply on this segment and
12085 	 * it's less than ts_recent, drop it.
12086 	 */
12087 	if ((to->to_flags & TOF_TS) != 0 && tp->ts_recent &&
12088 	    TSTMP_LT(to->to_tsval, tp->ts_recent)) {
12089 		if (ctf_ts_check(m, th, tp, tlen, thflags, &ret_val))
12090 			return (ret_val);
12091 	}
12092 	if (_ctf_drop_checks(to, m, th, tp, &tlen, &thflags, &drop_hdrlen, &ret_val,
12093 			      &rack->r_ctl.challenge_ack_ts,
12094 			      &rack->r_ctl.challenge_ack_cnt)) {
12095 		return (ret_val);
12096 	}
12097 	/*
12098 	 * If new data are received on a connection after the user processes
12099 	 * are gone, then RST the other end.
12100 	 */
12101 	if ((so->so_state & SS_NOFDREF) && tlen) {
12102 		if (rack_check_data_after_close(m, tp, &tlen, th, so))
12103 			return (1);
12104 	}
12105 	/*
12106 	 * If last ACK falls within this segment's sequence numbers, record
12107 	 * its timestamp. NOTE: 1) That the test incorporates suggestions
12108 	 * from the latest proposal of the tcplw@cray.com list (Braden
12109 	 * 1993/04/26). 2) That updating only on newer timestamps interferes
12110 	 * with our earlier PAWS tests, so this check should be solely
12111 	 * predicated on the sequence space of this segment. 3) That we
12112 	 * modify the segment boundary check to be Last.ACK.Sent <= SEG.SEQ
12113 	 * + SEG.Len  instead of RFC1323's Last.ACK.Sent < SEG.SEQ +
12114 	 * SEG.Len, This modified check allows us to overcome RFC1323's
12115 	 * limitations as described in Stevens TCP/IP Illustrated Vol. 2
12116 	 * p.869. In such cases, we can still calculate the RTT correctly
12117 	 * when RCV.NXT == Last.ACK.Sent.
12118 	 */
12119 	if ((to->to_flags & TOF_TS) != 0 &&
12120 	    SEQ_LEQ(th->th_seq, tp->last_ack_sent) &&
12121 	    SEQ_LEQ(tp->last_ack_sent, th->th_seq + tlen +
12122 	    ((thflags & (TH_SYN | TH_FIN)) != 0))) {
12123 		tp->ts_recent_age = tcp_ts_getticks();
12124 		tp->ts_recent = to->to_tsval;
12125 	}
12126 	/*
12127 	 * If the ACK bit is off:  if in SYN-RECEIVED state or SENDSYN flag
12128 	 * is on (half-synchronized state), then queue data for later
12129 	 * processing; else drop segment and return.
12130 	 */
12131 	if ((thflags & TH_ACK) == 0) {
12132 		if (tp->t_flags & TF_NEEDSYN) {
12133 			return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
12134 			    tiwin, thflags, nxt_pkt));
12135 		} else if (tp->t_flags & TF_ACKNOW) {
12136 			ctf_do_dropafterack(m, tp, th, thflags, tlen, &ret_val);
12137 			((struct tcp_rack *)tp->t_fb_ptr)->r_wanted_output = 1;
12138 			return (ret_val);
12139 		} else {
12140 			ctf_do_drop(m, NULL);
12141 			return (0);
12142 		}
12143 	}
12144 	/*
12145 	 * Ack processing.
12146 	 */
12147 	if (rack_process_ack(m, th, so, tp, to, tiwin, tlen, &ourfinisacked, thflags, &ret_val)) {
12148 		return (ret_val);
12149 	}
12150 	if (ourfinisacked) {
12151 		tcp_twstart(tp);
12152 		m_freem(m);
12153 		return (1);
12154 	}
12155 	if (sbavail(&so->so_snd)) {
12156 		if (ctf_progress_timeout_check(tp, true)) {
12157 			rack_log_progress_event((struct tcp_rack *)tp->t_fb_ptr,
12158 						tp, tick, PROGRESS_DROP, __LINE__);
12159 			tcp_set_inp_to_drop(tp->t_inpcb, ETIMEDOUT);
12160 			ctf_do_dropwithreset(m, tp, th, BANDLIM_RST_OPENPORT, tlen);
12161 			return (1);
12162 		}
12163 	}
12164 	return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
12165 	    tiwin, thflags, nxt_pkt));
12166 }
12167 
12168 /*
12169  * Return value of 1, the TCB is unlocked and most
12170  * likely gone, return value of 0, the TCP is still
12171  * locked.
12172  */
12173 static int
12174 rack_do_lastack(struct mbuf *m, struct tcphdr *th, struct socket *so,
12175     struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen,
12176     uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos)
12177 {
12178 	int32_t ret_val = 0;
12179 	int32_t ourfinisacked = 0;
12180 	struct tcp_rack *rack;
12181 
12182 	rack = (struct tcp_rack *)tp->t_fb_ptr;
12183 	ctf_calc_rwin(so, tp);
12184 
12185 	if ((thflags & TH_RST) ||
12186 	    (tp->t_fin_is_rst && (thflags & TH_FIN)))
12187 		return (ctf_process_rst(m, th, so, tp));
12188 	/*
12189 	 * RFC5961 Section 4.2 Send challenge ACK for any SYN in
12190 	 * synchronized state.
12191 	 */
12192 	if (thflags & TH_SYN) {
12193 		ctf_challenge_ack(m, th, tp, &ret_val);
12194 		return (ret_val);
12195 	}
12196 	/*
12197 	 * RFC 1323 PAWS: If we have a timestamp reply on this segment and
12198 	 * it's less than ts_recent, drop it.
12199 	 */
12200 	if ((to->to_flags & TOF_TS) != 0 && tp->ts_recent &&
12201 	    TSTMP_LT(to->to_tsval, tp->ts_recent)) {
12202 		if (ctf_ts_check(m, th, tp, tlen, thflags, &ret_val))
12203 			return (ret_val);
12204 	}
12205 	if (_ctf_drop_checks(to, m, th, tp, &tlen, &thflags, &drop_hdrlen, &ret_val,
12206 			      &rack->r_ctl.challenge_ack_ts,
12207 			      &rack->r_ctl.challenge_ack_cnt)) {
12208 		return (ret_val);
12209 	}
12210 	/*
12211 	 * If new data are received on a connection after the user processes
12212 	 * are gone, then RST the other end.
12213 	 */
12214 	if ((so->so_state & SS_NOFDREF) && tlen) {
12215 		if (rack_check_data_after_close(m, tp, &tlen, th, so))
12216 			return (1);
12217 	}
12218 	/*
12219 	 * If last ACK falls within this segment's sequence numbers, record
12220 	 * its timestamp. NOTE: 1) That the test incorporates suggestions
12221 	 * from the latest proposal of the tcplw@cray.com list (Braden
12222 	 * 1993/04/26). 2) That updating only on newer timestamps interferes
12223 	 * with our earlier PAWS tests, so this check should be solely
12224 	 * predicated on the sequence space of this segment. 3) That we
12225 	 * modify the segment boundary check to be Last.ACK.Sent <= SEG.SEQ
12226 	 * + SEG.Len  instead of RFC1323's Last.ACK.Sent < SEG.SEQ +
12227 	 * SEG.Len, This modified check allows us to overcome RFC1323's
12228 	 * limitations as described in Stevens TCP/IP Illustrated Vol. 2
12229 	 * p.869. In such cases, we can still calculate the RTT correctly
12230 	 * when RCV.NXT == Last.ACK.Sent.
12231 	 */
12232 	if ((to->to_flags & TOF_TS) != 0 &&
12233 	    SEQ_LEQ(th->th_seq, tp->last_ack_sent) &&
12234 	    SEQ_LEQ(tp->last_ack_sent, th->th_seq + tlen +
12235 	    ((thflags & (TH_SYN | TH_FIN)) != 0))) {
12236 		tp->ts_recent_age = tcp_ts_getticks();
12237 		tp->ts_recent = to->to_tsval;
12238 	}
12239 	/*
12240 	 * If the ACK bit is off:  if in SYN-RECEIVED state or SENDSYN flag
12241 	 * is on (half-synchronized state), then queue data for later
12242 	 * processing; else drop segment and return.
12243 	 */
12244 	if ((thflags & TH_ACK) == 0) {
12245 		if (tp->t_flags & TF_NEEDSYN) {
12246 			return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
12247 			    tiwin, thflags, nxt_pkt));
12248 		} else if (tp->t_flags & TF_ACKNOW) {
12249 			ctf_do_dropafterack(m, tp, th, thflags, tlen, &ret_val);
12250 			((struct tcp_rack *)tp->t_fb_ptr)->r_wanted_output = 1;
12251 			return (ret_val);
12252 		} else {
12253 			ctf_do_drop(m, NULL);
12254 			return (0);
12255 		}
12256 	}
12257 	/*
12258 	 * case TCPS_LAST_ACK: Ack processing.
12259 	 */
12260 	if (rack_process_ack(m, th, so, tp, to, tiwin, tlen, &ourfinisacked, thflags, &ret_val)) {
12261 		return (ret_val);
12262 	}
12263 	if (ourfinisacked) {
12264 		tp = tcp_close(tp);
12265 		ctf_do_drop(m, tp);
12266 		return (1);
12267 	}
12268 	if (sbavail(&so->so_snd)) {
12269 		if (ctf_progress_timeout_check(tp, true)) {
12270 			rack_log_progress_event((struct tcp_rack *)tp->t_fb_ptr,
12271 						tp, tick, PROGRESS_DROP, __LINE__);
12272 			tcp_set_inp_to_drop(tp->t_inpcb, ETIMEDOUT);
12273 			ctf_do_dropwithreset(m, tp, th, BANDLIM_RST_OPENPORT, tlen);
12274 			return (1);
12275 		}
12276 	}
12277 	return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
12278 	    tiwin, thflags, nxt_pkt));
12279 }
12280 
12281 /*
12282  * Return value of 1, the TCB is unlocked and most
12283  * likely gone, return value of 0, the TCP is still
12284  * locked.
12285  */
12286 static int
12287 rack_do_fin_wait_2(struct mbuf *m, struct tcphdr *th, struct socket *so,
12288     struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen,
12289     uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos)
12290 {
12291 	int32_t ret_val = 0;
12292 	int32_t ourfinisacked = 0;
12293 	struct tcp_rack *rack;
12294 
12295 	rack = (struct tcp_rack *)tp->t_fb_ptr;
12296 	ctf_calc_rwin(so, tp);
12297 
12298 	/* Reset receive buffer auto scaling when not in bulk receive mode. */
12299 	if ((thflags & TH_RST) ||
12300 	    (tp->t_fin_is_rst && (thflags & TH_FIN)))
12301 		return (ctf_process_rst(m, th, so, tp));
12302 	/*
12303 	 * RFC5961 Section 4.2 Send challenge ACK for any SYN in
12304 	 * synchronized state.
12305 	 */
12306 	if (thflags & TH_SYN) {
12307 		ctf_challenge_ack(m, th, tp, &ret_val);
12308 		return (ret_val);
12309 	}
12310 	/*
12311 	 * RFC 1323 PAWS: If we have a timestamp reply on this segment and
12312 	 * it's less than ts_recent, drop it.
12313 	 */
12314 	if ((to->to_flags & TOF_TS) != 0 && tp->ts_recent &&
12315 	    TSTMP_LT(to->to_tsval, tp->ts_recent)) {
12316 		if (ctf_ts_check(m, th, tp, tlen, thflags, &ret_val))
12317 			return (ret_val);
12318 	}
12319 	if (_ctf_drop_checks(to, m, th, tp, &tlen, &thflags, &drop_hdrlen, &ret_val,
12320 			      &rack->r_ctl.challenge_ack_ts,
12321 			      &rack->r_ctl.challenge_ack_cnt)) {
12322 		return (ret_val);
12323 	}
12324 	/*
12325 	 * If new data are received on a connection after the user processes
12326 	 * are gone, then RST the other end.
12327 	 */
12328 	if ((so->so_state & SS_NOFDREF) &&
12329 	    tlen) {
12330 		if (rack_check_data_after_close(m, tp, &tlen, th, so))
12331 			return (1);
12332 	}
12333 	/*
12334 	 * If last ACK falls within this segment's sequence numbers, record
12335 	 * its timestamp. NOTE: 1) That the test incorporates suggestions
12336 	 * from the latest proposal of the tcplw@cray.com list (Braden
12337 	 * 1993/04/26). 2) That updating only on newer timestamps interferes
12338 	 * with our earlier PAWS tests, so this check should be solely
12339 	 * predicated on the sequence space of this segment. 3) That we
12340 	 * modify the segment boundary check to be Last.ACK.Sent <= SEG.SEQ
12341 	 * + SEG.Len  instead of RFC1323's Last.ACK.Sent < SEG.SEQ +
12342 	 * SEG.Len, This modified check allows us to overcome RFC1323's
12343 	 * limitations as described in Stevens TCP/IP Illustrated Vol. 2
12344 	 * p.869. In such cases, we can still calculate the RTT correctly
12345 	 * when RCV.NXT == Last.ACK.Sent.
12346 	 */
12347 	if ((to->to_flags & TOF_TS) != 0 &&
12348 	    SEQ_LEQ(th->th_seq, tp->last_ack_sent) &&
12349 	    SEQ_LEQ(tp->last_ack_sent, th->th_seq + tlen +
12350 	    ((thflags & (TH_SYN | TH_FIN)) != 0))) {
12351 		tp->ts_recent_age = tcp_ts_getticks();
12352 		tp->ts_recent = to->to_tsval;
12353 	}
12354 	/*
12355 	 * If the ACK bit is off:  if in SYN-RECEIVED state or SENDSYN flag
12356 	 * is on (half-synchronized state), then queue data for later
12357 	 * processing; else drop segment and return.
12358 	 */
12359 	if ((thflags & TH_ACK) == 0) {
12360 		if (tp->t_flags & TF_NEEDSYN) {
12361 			return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
12362 			    tiwin, thflags, nxt_pkt));
12363 		} else if (tp->t_flags & TF_ACKNOW) {
12364 			ctf_do_dropafterack(m, tp, th, thflags, tlen, &ret_val);
12365 			((struct tcp_rack *)tp->t_fb_ptr)->r_wanted_output = 1;
12366 			return (ret_val);
12367 		} else {
12368 			ctf_do_drop(m, NULL);
12369 			return (0);
12370 		}
12371 	}
12372 	/*
12373 	 * Ack processing.
12374 	 */
12375 	if (rack_process_ack(m, th, so, tp, to, tiwin, tlen, &ourfinisacked, thflags, &ret_val)) {
12376 		return (ret_val);
12377 	}
12378 	if (sbavail(&so->so_snd)) {
12379 		if (ctf_progress_timeout_check(tp, true)) {
12380 			rack_log_progress_event((struct tcp_rack *)tp->t_fb_ptr,
12381 						tp, tick, PROGRESS_DROP, __LINE__);
12382 			tcp_set_inp_to_drop(tp->t_inpcb, ETIMEDOUT);
12383 			ctf_do_dropwithreset(m, tp, th, BANDLIM_RST_OPENPORT, tlen);
12384 			return (1);
12385 		}
12386 	}
12387 	return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
12388 	    tiwin, thflags, nxt_pkt));
12389 }
12390 
12391 static void inline
12392 rack_clear_rate_sample(struct tcp_rack *rack)
12393 {
12394 	rack->r_ctl.rack_rs.rs_flags = RACK_RTT_EMPTY;
12395 	rack->r_ctl.rack_rs.rs_rtt_cnt = 0;
12396 	rack->r_ctl.rack_rs.rs_rtt_tot = 0;
12397 }
12398 
12399 static void
12400 rack_set_pace_segments(struct tcpcb *tp, struct tcp_rack *rack, uint32_t line, uint64_t *fill_override)
12401 {
12402 	uint64_t bw_est, rate_wanted;
12403 	int chged = 0;
12404 	uint32_t user_max, orig_min, orig_max;
12405 
12406 	orig_min = rack->r_ctl.rc_pace_min_segs;
12407 	orig_max = rack->r_ctl.rc_pace_max_segs;
12408 	user_max = ctf_fixed_maxseg(tp) * rack->rc_user_set_max_segs;
12409 	if (ctf_fixed_maxseg(tp) != rack->r_ctl.rc_pace_min_segs)
12410 		chged = 1;
12411 	rack->r_ctl.rc_pace_min_segs = ctf_fixed_maxseg(tp);
12412 	if (rack->use_fixed_rate || rack->rc_force_max_seg) {
12413 		if (user_max != rack->r_ctl.rc_pace_max_segs)
12414 			chged = 1;
12415 	}
12416 	if (rack->rc_force_max_seg) {
12417 		rack->r_ctl.rc_pace_max_segs = user_max;
12418 	} else if (rack->use_fixed_rate) {
12419 		bw_est = rack_get_bw(rack);
12420 		if ((rack->r_ctl.crte == NULL) ||
12421 		    (bw_est != rack->r_ctl.crte->rate)) {
12422 			rack->r_ctl.rc_pace_max_segs = user_max;
12423 		} else {
12424 			/* We are pacing right at the hardware rate */
12425 			uint32_t segsiz;
12426 
12427 			segsiz = min(ctf_fixed_maxseg(tp),
12428 				     rack->r_ctl.rc_pace_min_segs);
12429 			rack->r_ctl.rc_pace_max_segs = tcp_get_pacing_burst_size(
12430 				                           tp, bw_est, segsiz, 0,
12431 							   rack->r_ctl.crte, NULL);
12432 		}
12433 	} else if (rack->rc_always_pace) {
12434 		if (rack->r_ctl.gp_bw ||
12435 #ifdef NETFLIX_PEAKRATE
12436 		    rack->rc_tp->t_maxpeakrate ||
12437 #endif
12438 		    rack->r_ctl.init_rate) {
12439 			/* We have a rate of some sort set */
12440 			uint32_t  orig;
12441 
12442 			bw_est = rack_get_bw(rack);
12443 			orig = rack->r_ctl.rc_pace_max_segs;
12444 			if (fill_override)
12445 				rate_wanted = *fill_override;
12446 			else
12447 				rate_wanted = rack_get_output_bw(rack, bw_est, NULL, NULL);
12448 			if (rate_wanted) {
12449 				/* We have something */
12450 				rack->r_ctl.rc_pace_max_segs = rack_get_pacing_len(rack,
12451 										   rate_wanted,
12452 										   ctf_fixed_maxseg(rack->rc_tp));
12453 			} else
12454 				rack->r_ctl.rc_pace_max_segs = rack->r_ctl.rc_pace_min_segs;
12455 			if (orig != rack->r_ctl.rc_pace_max_segs)
12456 				chged = 1;
12457 		} else if ((rack->r_ctl.gp_bw == 0) &&
12458 			   (rack->r_ctl.rc_pace_max_segs == 0)) {
12459 			/*
12460 			 * If we have nothing limit us to bursting
12461 			 * out IW sized pieces.
12462 			 */
12463 			chged = 1;
12464 			rack->r_ctl.rc_pace_max_segs = rc_init_window(rack);
12465 		}
12466 	}
12467 	if (rack->r_ctl.rc_pace_max_segs > PACE_MAX_IP_BYTES) {
12468 		chged = 1;
12469 		rack->r_ctl.rc_pace_max_segs = PACE_MAX_IP_BYTES;
12470 	}
12471 	if (chged)
12472 		rack_log_type_pacing_sizes(tp, rack, orig_min, orig_max, line, 2);
12473 }
12474 
12475 
12476 static void
12477 rack_init_fsb_block(struct tcpcb *tp, struct tcp_rack *rack)
12478 {
12479 #ifdef INET6
12480 	struct ip6_hdr *ip6 = NULL;
12481 #endif
12482 #ifdef INET
12483 	struct ip *ip = NULL;
12484 #endif
12485 	struct udphdr *udp = NULL;
12486 
12487 	/* Ok lets fill in the fast block, it can only be used with no IP options! */
12488 #ifdef INET6
12489 	if (rack->r_is_v6) {
12490 		rack->r_ctl.fsb.tcp_ip_hdr_len = sizeof(struct ip6_hdr) + sizeof(struct tcphdr);
12491 		ip6 = (struct ip6_hdr *)rack->r_ctl.fsb.tcp_ip_hdr;
12492 		if (tp->t_port) {
12493 			rack->r_ctl.fsb.tcp_ip_hdr_len += sizeof(struct udphdr);
12494 			udp = (struct udphdr *)((caddr_t)ip6 + sizeof(struct ip6_hdr));
12495 			udp->uh_sport = htons(V_tcp_udp_tunneling_port);
12496 			udp->uh_dport = tp->t_port;
12497 			rack->r_ctl.fsb.udp = udp;
12498 			rack->r_ctl.fsb.th = (struct tcphdr *)(udp + 1);
12499 		} else
12500 		{
12501 			rack->r_ctl.fsb.th = (struct tcphdr *)(ip6 + 1);
12502 			rack->r_ctl.fsb.udp = NULL;
12503 		}
12504 		tcpip_fillheaders(rack->rc_inp,
12505 				  tp->t_port,
12506 				  ip6, rack->r_ctl.fsb.th);
12507 	} else
12508 #endif				/* INET6 */
12509 	{
12510 		rack->r_ctl.fsb.tcp_ip_hdr_len = sizeof(struct tcpiphdr);
12511 		ip = (struct ip *)rack->r_ctl.fsb.tcp_ip_hdr;
12512 		if (tp->t_port) {
12513 			rack->r_ctl.fsb.tcp_ip_hdr_len += sizeof(struct udphdr);
12514 			udp = (struct udphdr *)((caddr_t)ip + sizeof(struct ip));
12515 			udp->uh_sport = htons(V_tcp_udp_tunneling_port);
12516 			udp->uh_dport = tp->t_port;
12517 			rack->r_ctl.fsb.udp = udp;
12518 			rack->r_ctl.fsb.th = (struct tcphdr *)(udp + 1);
12519 		} else
12520 		{
12521 			rack->r_ctl.fsb.udp = NULL;
12522 			rack->r_ctl.fsb.th = (struct tcphdr *)(ip + 1);
12523 		}
12524 		tcpip_fillheaders(rack->rc_inp,
12525 				  tp->t_port,
12526 				  ip, rack->r_ctl.fsb.th);
12527 	}
12528 	rack->r_fsb_inited = 1;
12529 }
12530 
12531 static int
12532 rack_init_fsb(struct tcpcb *tp, struct tcp_rack *rack)
12533 {
12534 	/*
12535 	 * Allocate the larger of spaces V6 if available else just
12536 	 * V4 and include udphdr (overbook)
12537 	 */
12538 #ifdef INET6
12539 	rack->r_ctl.fsb.tcp_ip_hdr_len = sizeof(struct ip6_hdr) + sizeof(struct tcphdr) + sizeof(struct udphdr);
12540 #else
12541 	rack->r_ctl.fsb.tcp_ip_hdr_len = sizeof(struct tcpiphdr) + sizeof(struct udphdr);
12542 #endif
12543 	rack->r_ctl.fsb.tcp_ip_hdr = malloc(rack->r_ctl.fsb.tcp_ip_hdr_len,
12544 					    M_TCPFSB, M_NOWAIT|M_ZERO);
12545 	if (rack->r_ctl.fsb.tcp_ip_hdr == NULL) {
12546 		return (ENOMEM);
12547 	}
12548 	rack->r_fsb_inited = 0;
12549 	return (0);
12550 }
12551 
12552 static int
12553 rack_init(struct tcpcb *tp)
12554 {
12555 	struct tcp_rack *rack = NULL;
12556 	struct rack_sendmap *insret;
12557 	uint32_t iwin, snt, us_cts;
12558 	int err;
12559 
12560 	tp->t_fb_ptr = uma_zalloc(rack_pcb_zone, M_NOWAIT);
12561 	if (tp->t_fb_ptr == NULL) {
12562 		/*
12563 		 * We need to allocate memory but cant. The INP and INP_INFO
12564 		 * locks and they are recusive (happens during setup. So a
12565 		 * scheme to drop the locks fails :(
12566 		 *
12567 		 */
12568 		return (ENOMEM);
12569 	}
12570 	memset(tp->t_fb_ptr, 0, sizeof(struct tcp_rack));
12571 
12572 	rack = (struct tcp_rack *)tp->t_fb_ptr;
12573 	RB_INIT(&rack->r_ctl.rc_mtree);
12574 	TAILQ_INIT(&rack->r_ctl.rc_free);
12575 	TAILQ_INIT(&rack->r_ctl.rc_tmap);
12576 	rack->rc_tp = tp;
12577 	rack->rc_inp = tp->t_inpcb;
12578 	/* Set the flag */
12579 	rack->r_is_v6 = (tp->t_inpcb->inp_vflag & INP_IPV6) != 0;
12580 	/* Probably not needed but lets be sure */
12581 	rack_clear_rate_sample(rack);
12582 	/*
12583 	 * Save off the default values, socket options will poke
12584 	 * at these if pacing is not on or we have not yet
12585 	 * reached where pacing is on (gp_ready/fixed enabled).
12586 	 * When they get set into the CC module (when gp_ready
12587 	 * is enabled or we enable fixed) then we will set these
12588 	 * values into the CC and place in here the old values
12589 	 * so we have a restoral. Then we will set the flag
12590 	 * rc_pacing_cc_set. That way whenever we turn off pacing
12591 	 * or switch off this stack, we will know to go restore
12592 	 * the saved values.
12593 	 */
12594 	rack->r_ctl.rc_saved_beta.beta = V_newreno_beta_ecn;
12595 	rack->r_ctl.rc_saved_beta.beta_ecn = V_newreno_beta_ecn;
12596 	/* We want abe like behavior as well */
12597 	rack->r_ctl.rc_saved_beta.newreno_flags |= CC_NEWRENO_BETA_ECN_ENABLED;
12598 	rack->r_ctl.rc_reorder_fade = rack_reorder_fade;
12599 	rack->rc_allow_data_af_clo = rack_ignore_data_after_close;
12600 	rack->r_ctl.rc_tlp_threshold = rack_tlp_thresh;
12601 	rack->r_ctl.roundends = tp->snd_max;
12602 	if (use_rack_rr)
12603 		rack->use_rack_rr = 1;
12604 	if (V_tcp_delack_enabled)
12605 		tp->t_delayed_ack = 1;
12606 	else
12607 		tp->t_delayed_ack = 0;
12608 #ifdef TCP_ACCOUNTING
12609 	if (rack_tcp_accounting) {
12610 		tp->t_flags2 |= TF2_TCP_ACCOUNTING;
12611 	}
12612 #endif
12613 	if (rack_enable_shared_cwnd)
12614 		rack->rack_enable_scwnd = 1;
12615 	rack->rc_user_set_max_segs = rack_hptsi_segments;
12616 	rack->rc_force_max_seg = 0;
12617 	if (rack_use_imac_dack)
12618 		rack->rc_dack_mode = 1;
12619 	TAILQ_INIT(&rack->r_ctl.opt_list);
12620 	rack->r_ctl.rc_reorder_shift = rack_reorder_thresh;
12621 	rack->r_ctl.rc_pkt_delay = rack_pkt_delay;
12622 	rack->r_ctl.rc_tlp_cwnd_reduce = rack_lower_cwnd_at_tlp;
12623 	rack->r_ctl.rc_lowest_us_rtt = 0xffffffff;
12624 	rack->r_ctl.rc_highest_us_rtt = 0;
12625 	rack->r_ctl.bw_rate_cap = rack_bw_rate_cap;
12626 	rack->r_ctl.timer_slop = TICKS_2_USEC(tcp_rexmit_slop);
12627 	if (rack_use_cmp_acks)
12628 		rack->r_use_cmp_ack = 1;
12629 	if (rack_disable_prr)
12630 		rack->rack_no_prr = 1;
12631 	if (rack_gp_no_rec_chg)
12632 		rack->rc_gp_no_rec_chg = 1;
12633 	if (rack_pace_every_seg && tcp_can_enable_pacing()) {
12634 		rack->rc_always_pace = 1;
12635 		if (rack->use_fixed_rate || rack->gp_ready)
12636 			rack_set_cc_pacing(rack);
12637 	} else
12638 		rack->rc_always_pace = 0;
12639 	if (rack_enable_mqueue_for_nonpaced || rack->r_use_cmp_ack)
12640 		rack->r_mbuf_queue = 1;
12641 	else
12642 		rack->r_mbuf_queue = 0;
12643 	if  (rack->r_mbuf_queue || rack->rc_always_pace || rack->r_use_cmp_ack)
12644 		tp->t_inpcb->inp_flags2 |= INP_SUPPORTS_MBUFQ;
12645 	else
12646 		tp->t_inpcb->inp_flags2 &= ~INP_SUPPORTS_MBUFQ;
12647 	rack_set_pace_segments(tp, rack, __LINE__, NULL);
12648 	if (rack_limits_scwnd)
12649 		rack->r_limit_scw = 1;
12650 	else
12651 		rack->r_limit_scw = 0;
12652 	rack->rc_labc = V_tcp_abc_l_var;
12653 	rack->r_ctl.rc_high_rwnd = tp->snd_wnd;
12654 	rack->r_ctl.cwnd_to_use = tp->snd_cwnd;
12655 	rack->r_ctl.rc_rate_sample_method = rack_rate_sample_method;
12656 	rack->rack_tlp_threshold_use = rack_tlp_threshold_use;
12657 	rack->r_ctl.rc_prr_sendalot = rack_send_a_lot_in_prr;
12658 	rack->r_ctl.rc_min_to = rack_min_to;
12659 	microuptime(&rack->r_ctl.act_rcv_time);
12660 	rack->r_ctl.rc_last_time_decay = rack->r_ctl.act_rcv_time;
12661 	rack->r_running_late = 0;
12662 	rack->r_running_early = 0;
12663 	rack->rc_init_win = rack_default_init_window;
12664 	rack->r_ctl.rack_per_of_gp_ss = rack_per_of_gp_ss;
12665 	if (rack_hw_up_only)
12666 		rack->r_up_only = 1;
12667 	if (rack_do_dyn_mul) {
12668 		/* When dynamic adjustment is on CA needs to start at 100% */
12669 		rack->rc_gp_dyn_mul = 1;
12670 		if (rack_do_dyn_mul >= 100)
12671 			rack->r_ctl.rack_per_of_gp_ca = rack_do_dyn_mul;
12672 	} else
12673 		rack->r_ctl.rack_per_of_gp_ca = rack_per_of_gp_ca;
12674 	rack->r_ctl.rack_per_of_gp_rec = rack_per_of_gp_rec;
12675 	rack->r_ctl.rack_per_of_gp_probertt = rack_per_of_gp_probertt;
12676 	rack->r_ctl.rc_tlp_rxt_last_time = tcp_tv_to_mssectick(&rack->r_ctl.act_rcv_time);
12677 	setup_time_filter_small(&rack->r_ctl.rc_gp_min_rtt, FILTER_TYPE_MIN,
12678 				rack_probertt_filter_life);
12679 	us_cts = tcp_tv_to_usectick(&rack->r_ctl.act_rcv_time);
12680 	rack->r_ctl.rc_lower_rtt_us_cts = us_cts;
12681 	rack->r_ctl.rc_time_of_last_probertt = us_cts;
12682 	rack->r_ctl.challenge_ack_ts = tcp_ts_getticks();
12683 	rack->r_ctl.rc_time_probertt_starts = 0;
12684 	if (rack_dsack_std_based & 0x1) {
12685 		/* Basically this means all rack timers are at least (srtt + 1/4 srtt) */
12686 		rack->rc_rack_tmr_std_based = 1;
12687 	}
12688 	if (rack_dsack_std_based & 0x2) {
12689 		/* Basically this means  rack timers are extended based on dsack by up to (2 * srtt) */
12690 		rack->rc_rack_use_dsack = 1;
12691 	}
12692 	/* We require at least one measurement, even if the sysctl is 0 */
12693 	if (rack_req_measurements)
12694 		rack->r_ctl.req_measurements = rack_req_measurements;
12695 	else
12696 		rack->r_ctl.req_measurements = 1;
12697 	if (rack_enable_hw_pacing)
12698 		rack->rack_hdw_pace_ena = 1;
12699 	if (rack_hw_rate_caps)
12700 		rack->r_rack_hw_rate_caps = 1;
12701 	/* Do we force on detection? */
12702 #ifdef NETFLIX_EXP_DETECTION
12703 	if (tcp_force_detection)
12704 		rack->do_detection = 1;
12705 	else
12706 #endif
12707 		rack->do_detection = 0;
12708 	if (rack_non_rxt_use_cr)
12709 		rack->rack_rec_nonrxt_use_cr = 1;
12710 	err = rack_init_fsb(tp, rack);
12711 	if (err) {
12712 		uma_zfree(rack_pcb_zone, tp->t_fb_ptr);
12713 		tp->t_fb_ptr = NULL;
12714 		return (err);
12715 	}
12716 	if (tp->snd_una != tp->snd_max) {
12717 		/* Create a send map for the current outstanding data */
12718 		struct rack_sendmap *rsm;
12719 
12720 		rsm = rack_alloc(rack);
12721 		if (rsm == NULL) {
12722 			uma_zfree(rack_pcb_zone, tp->t_fb_ptr);
12723 			tp->t_fb_ptr = NULL;
12724 			return (ENOMEM);
12725 		}
12726 		rsm->r_no_rtt_allowed = 1;
12727 		rsm->r_tim_lastsent[0] = rack_to_usec_ts(&rack->r_ctl.act_rcv_time);
12728 		rsm->r_rtr_cnt = 1;
12729 		rsm->r_rtr_bytes = 0;
12730 		if (tp->t_flags & TF_SENTFIN) {
12731 			rsm->r_end = tp->snd_max - 1;
12732 			rsm->r_flags |= RACK_HAS_FIN;
12733 		} else {
12734 			rsm->r_end = tp->snd_max;
12735 		}
12736 		if (tp->snd_una == tp->iss) {
12737 			/* The data space is one beyond snd_una */
12738 			rsm->r_flags |= RACK_HAS_SYN;
12739 			rsm->r_start = tp->iss;
12740 			rsm->r_end = rsm->r_start + (tp->snd_max - tp->snd_una);
12741 		} else
12742 			rsm->r_start = tp->snd_una;
12743 		rsm->r_dupack = 0;
12744 		if (rack->rc_inp->inp_socket->so_snd.sb_mb != NULL) {
12745 			rsm->m = sbsndmbuf(&rack->rc_inp->inp_socket->so_snd, 0, &rsm->soff);
12746 			if (rsm->m)
12747 				rsm->orig_m_len = rsm->m->m_len;
12748 			else
12749 				rsm->orig_m_len = 0;
12750 		} else {
12751 			/*
12752 			 * This can happen if we have a stand-alone FIN or
12753 			 *  SYN.
12754 			 */
12755 			rsm->m = NULL;
12756 			rsm->orig_m_len = 0;
12757 			rsm->soff = 0;
12758 		}
12759 		insret = RB_INSERT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm);
12760 #ifdef INVARIANTS
12761 		if (insret != NULL) {
12762 			panic("Insert in rb tree fails ret:%p rack:%p rsm:%p",
12763 			      insret, rack, rsm);
12764 		}
12765 #endif
12766 		TAILQ_INSERT_TAIL(&rack->r_ctl.rc_tmap, rsm, r_tnext);
12767 		rsm->r_in_tmap = 1;
12768 	}
12769 	/*
12770 	 * Timers in Rack are kept in microseconds so lets
12771 	 * convert any initial incoming variables
12772 	 * from ticks into usecs. Note that we
12773 	 * also change the values of t_srtt and t_rttvar, if
12774 	 * they are non-zero. They are kept with a 5
12775 	 * bit decimal so we have to carefully convert
12776 	 * these to get the full precision.
12777 	 */
12778 	rack_convert_rtts(tp);
12779 	tp->t_rttlow = TICKS_2_USEC(tp->t_rttlow);
12780 	if (rack_do_hystart) {
12781 		struct sockopt sopt;
12782 		struct cc_newreno_opts opt;
12783 
12784 		sopt.sopt_valsize = sizeof(struct cc_newreno_opts);
12785 		sopt.sopt_dir = SOPT_SET;
12786 		opt.name = CC_NEWRENO_ENABLE_HYSTART;
12787 		opt.val = rack_do_hystart;
12788 		if (CC_ALGO(tp)->ctl_output != NULL)
12789 			(void)CC_ALGO(tp)->ctl_output(tp->ccv, &sopt, &opt);
12790 	}
12791 	if (rack_def_profile)
12792 		rack_set_profile(rack, rack_def_profile);
12793 	/* Cancel the GP measurement in progress */
12794 	tp->t_flags &= ~TF_GPUTINPROG;
12795 	if (SEQ_GT(tp->snd_max, tp->iss))
12796 		snt = tp->snd_max - tp->iss;
12797 	else
12798 		snt = 0;
12799 	iwin = rc_init_window(rack);
12800 	if (snt < iwin) {
12801 		/* We are not past the initial window
12802 		 * so we need to make sure cwnd is
12803 		 * correct.
12804 		 */
12805 		if (tp->snd_cwnd < iwin)
12806 			tp->snd_cwnd = iwin;
12807 		/*
12808 		 * If we are within the initial window
12809 		 * we want ssthresh to be unlimited. Setting
12810 		 * it to the rwnd (which the default stack does
12811 		 * and older racks) is not really a good idea
12812 		 * since we want to be in SS and grow both the
12813 		 * cwnd and the rwnd (via dynamic rwnd growth). If
12814 		 * we set it to the rwnd then as the peer grows its
12815 		 * rwnd we will be stuck in CA and never hit SS.
12816 		 *
12817 		 * Its far better to raise it up high (this takes the
12818 		 * risk that there as been a loss already, probably
12819 		 * we should have an indicator in all stacks of loss
12820 		 * but we don't), but considering the normal use this
12821 		 * is a risk worth taking. The consequences of not
12822 		 * hitting SS are far worse than going one more time
12823 		 * into it early on (before we have sent even a IW).
12824 		 * It is highly unlikely that we will have had a loss
12825 		 * before getting the IW out.
12826 		 */
12827 		tp->snd_ssthresh = 0xffffffff;
12828 	}
12829 	rack_stop_all_timers(tp);
12830 	/* Lets setup the fsb block */
12831 	rack_start_hpts_timer(rack, tp, tcp_get_usecs(NULL), 0, 0, 0);
12832 	rack_log_rtt_shrinks(rack,  us_cts,  tp->t_rxtcur,
12833 			     __LINE__, RACK_RTTS_INIT);
12834 	return (0);
12835 }
12836 
12837 static int
12838 rack_handoff_ok(struct tcpcb *tp)
12839 {
12840 	if ((tp->t_state == TCPS_CLOSED) ||
12841 	    (tp->t_state == TCPS_LISTEN)) {
12842 		/* Sure no problem though it may not stick */
12843 		return (0);
12844 	}
12845 	if ((tp->t_state == TCPS_SYN_SENT) ||
12846 	    (tp->t_state == TCPS_SYN_RECEIVED)) {
12847 		/*
12848 		 * We really don't know if you support sack,
12849 		 * you have to get to ESTAB or beyond to tell.
12850 		 */
12851 		return (EAGAIN);
12852 	}
12853 	if ((tp->t_flags & TF_SENTFIN) && ((tp->snd_max - tp->snd_una) > 1)) {
12854 		/*
12855 		 * Rack will only send a FIN after all data is acknowledged.
12856 		 * So in this case we have more data outstanding. We can't
12857 		 * switch stacks until either all data and only the FIN
12858 		 * is left (in which case rack_init() now knows how
12859 		 * to deal with that) <or> all is acknowledged and we
12860 		 * are only left with incoming data, though why you
12861 		 * would want to switch to rack after all data is acknowledged
12862 		 * I have no idea (rrs)!
12863 		 */
12864 		return (EAGAIN);
12865 	}
12866 	if ((tp->t_flags & TF_SACK_PERMIT) || rack_sack_not_required){
12867 		return (0);
12868 	}
12869 	/*
12870 	 * If we reach here we don't do SACK on this connection so we can
12871 	 * never do rack.
12872 	 */
12873 	return (EINVAL);
12874 }
12875 
12876 
12877 static void
12878 rack_fini(struct tcpcb *tp, int32_t tcb_is_purged)
12879 {
12880 	int ack_cmp = 0;
12881 
12882 	if (tp->t_fb_ptr) {
12883 		struct tcp_rack *rack;
12884 		struct rack_sendmap *rsm, *nrsm, *rm;
12885 
12886 		rack = (struct tcp_rack *)tp->t_fb_ptr;
12887 		if (tp->t_in_pkt) {
12888 			/*
12889 			 * It is unsafe to process the packets since a
12890 			 * reset may be lurking in them (its rare but it
12891 			 * can occur). If we were to find a RST, then we
12892 			 * would end up dropping the connection and the
12893 			 * INP lock, so when we return the caller (tcp_usrreq)
12894 			 * will blow up when it trys to unlock the inp.
12895 			 */
12896 			struct mbuf *save, *m;
12897 
12898 			m = tp->t_in_pkt;
12899 			tp->t_in_pkt = NULL;
12900 			tp->t_tail_pkt = NULL;
12901 			while (m) {
12902 				save = m->m_nextpkt;
12903 				m->m_nextpkt = NULL;
12904 				m_freem(m);
12905 				m = save;
12906 			}
12907 			if ((tp->t_inpcb) &&
12908 			    (tp->t_inpcb->inp_flags2 & INP_MBUF_ACKCMP))
12909 				ack_cmp = 1;
12910 			if (ack_cmp) {
12911 				/* Total if we used large or small (if ack-cmp was used). */
12912 				if (rack->rc_inp->inp_flags2 & INP_MBUF_L_ACKS)
12913 					counter_u64_add(rack_large_ackcmp, 1);
12914 				else
12915 					counter_u64_add(rack_small_ackcmp, 1);
12916 			}
12917 		}
12918 		tp->t_flags &= ~TF_FORCEDATA;
12919 #ifdef NETFLIX_SHARED_CWND
12920 		if (rack->r_ctl.rc_scw) {
12921 			uint32_t limit;
12922 
12923 			if (rack->r_limit_scw)
12924 				limit = max(1, rack->r_ctl.rc_lowest_us_rtt);
12925 			else
12926 				limit = 0;
12927 			tcp_shared_cwnd_free_full(tp, rack->r_ctl.rc_scw,
12928 						  rack->r_ctl.rc_scw_index,
12929 						  limit);
12930 			rack->r_ctl.rc_scw = NULL;
12931 		}
12932 #endif
12933 		if (rack->r_ctl.fsb.tcp_ip_hdr) {
12934 			free(rack->r_ctl.fsb.tcp_ip_hdr, M_TCPFSB);
12935 			rack->r_ctl.fsb.tcp_ip_hdr = NULL;
12936 			rack->r_ctl.fsb.th = NULL;
12937 		}
12938 		/* Convert back to ticks, with  */
12939 		if (tp->t_srtt > 1) {
12940 			uint32_t val, frac;
12941 
12942 			val = USEC_2_TICKS(tp->t_srtt);
12943 			frac = tp->t_srtt % (HPTS_USEC_IN_SEC / hz);
12944 			tp->t_srtt = val << TCP_RTT_SHIFT;
12945 			/*
12946 			 * frac is the fractional part here is left
12947 			 * over from converting to hz and shifting.
12948 			 * We need to convert this to the 5 bit
12949 			 * remainder.
12950 			 */
12951 			if (frac) {
12952 				if (hz == 1000) {
12953 					frac = (((uint64_t)frac *  (uint64_t)TCP_RTT_SCALE) / (uint64_t)HPTS_USEC_IN_MSEC);
12954 				} else {
12955 					frac = (((uint64_t)frac * (uint64_t)(hz) * (uint64_t)TCP_RTT_SCALE) /(uint64_t)HPTS_USEC_IN_SEC);
12956 				}
12957 				tp->t_srtt += frac;
12958 			}
12959 		}
12960 		if (tp->t_rttvar) {
12961 			uint32_t val, frac;
12962 
12963 			val = USEC_2_TICKS(tp->t_rttvar);
12964 			frac = tp->t_srtt % (HPTS_USEC_IN_SEC / hz);
12965 			tp->t_rttvar = val <<  TCP_RTTVAR_SHIFT;
12966 			/*
12967 			 * frac is the fractional part here is left
12968 			 * over from converting to hz and shifting.
12969 			 * We need to convert this to the 5 bit
12970 			 * remainder.
12971 			 */
12972 			if (frac) {
12973 				if (hz == 1000) {
12974 					frac = (((uint64_t)frac *  (uint64_t)TCP_RTT_SCALE) / (uint64_t)HPTS_USEC_IN_MSEC);
12975 				} else {
12976 					frac = (((uint64_t)frac * (uint64_t)(hz) * (uint64_t)TCP_RTT_SCALE) /(uint64_t)HPTS_USEC_IN_SEC);
12977 				}
12978 				tp->t_rttvar += frac;
12979 			}
12980 		}
12981 		tp->t_rxtcur = USEC_2_TICKS(tp->t_rxtcur);
12982 		tp->t_rttlow = USEC_2_TICKS(tp->t_rttlow);
12983 		if (rack->rc_always_pace) {
12984 			tcp_decrement_paced_conn();
12985 			rack_undo_cc_pacing(rack);
12986 			rack->rc_always_pace = 0;
12987 		}
12988 		/* Clean up any options if they were not applied */
12989 		while (!TAILQ_EMPTY(&rack->r_ctl.opt_list)) {
12990 			struct deferred_opt_list *dol;
12991 
12992 			dol = TAILQ_FIRST(&rack->r_ctl.opt_list);
12993 			TAILQ_REMOVE(&rack->r_ctl.opt_list, dol, next);
12994 			free(dol, M_TCPDO);
12995 		}
12996 		/* rack does not use force data but other stacks may clear it */
12997 		if (rack->r_ctl.crte != NULL) {
12998 			tcp_rel_pacing_rate(rack->r_ctl.crte, tp);
12999 			rack->rack_hdrw_pacing = 0;
13000 			rack->r_ctl.crte = NULL;
13001 		}
13002 #ifdef TCP_BLACKBOX
13003 		tcp_log_flowend(tp);
13004 #endif
13005 		RB_FOREACH_SAFE(rsm, rack_rb_tree_head, &rack->r_ctl.rc_mtree, nrsm) {
13006 			rm = RB_REMOVE(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm);
13007 #ifdef INVARIANTS
13008 			if (rm != rsm) {
13009 				panic("At fini, rack:%p rsm:%p rm:%p",
13010 				      rack, rsm, rm);
13011 			}
13012 #endif
13013 			uma_zfree(rack_zone, rsm);
13014 		}
13015 		rsm = TAILQ_FIRST(&rack->r_ctl.rc_free);
13016 		while (rsm) {
13017 			TAILQ_REMOVE(&rack->r_ctl.rc_free, rsm, r_tnext);
13018 			uma_zfree(rack_zone, rsm);
13019 			rsm = TAILQ_FIRST(&rack->r_ctl.rc_free);
13020 		}
13021 		rack->rc_free_cnt = 0;
13022 		uma_zfree(rack_pcb_zone, tp->t_fb_ptr);
13023 		tp->t_fb_ptr = NULL;
13024 	}
13025 	if (tp->t_inpcb) {
13026 		tp->t_inpcb->inp_flags2 &= ~INP_SUPPORTS_MBUFQ;
13027 		tp->t_inpcb->inp_flags2 &= ~INP_MBUF_QUEUE_READY;
13028 		tp->t_inpcb->inp_flags2 &= ~INP_DONT_SACK_QUEUE;
13029 		tp->t_inpcb->inp_flags2 &= ~INP_MBUF_ACKCMP;
13030 		/* Cancel the GP measurement in progress */
13031 		tp->t_flags &= ~TF_GPUTINPROG;
13032 		tp->t_inpcb->inp_flags2 &= ~INP_MBUF_L_ACKS;
13033 	}
13034 	/* Make sure snd_nxt is correctly set */
13035 	tp->snd_nxt = tp->snd_max;
13036 }
13037 
13038 static void
13039 rack_set_state(struct tcpcb *tp, struct tcp_rack *rack)
13040 {
13041 	if ((rack->r_state == TCPS_CLOSED) && (tp->t_state != TCPS_CLOSED)) {
13042 		rack->r_is_v6 = (tp->t_inpcb->inp_vflag & INP_IPV6) != 0;
13043 	}
13044 	switch (tp->t_state) {
13045 	case TCPS_SYN_SENT:
13046 		rack->r_state = TCPS_SYN_SENT;
13047 		rack->r_substate = rack_do_syn_sent;
13048 		break;
13049 	case TCPS_SYN_RECEIVED:
13050 		rack->r_state = TCPS_SYN_RECEIVED;
13051 		rack->r_substate = rack_do_syn_recv;
13052 		break;
13053 	case TCPS_ESTABLISHED:
13054 		rack_set_pace_segments(tp, rack, __LINE__, NULL);
13055 		rack->r_state = TCPS_ESTABLISHED;
13056 		rack->r_substate = rack_do_established;
13057 		break;
13058 	case TCPS_CLOSE_WAIT:
13059 		rack_set_pace_segments(tp, rack, __LINE__, NULL);
13060 		rack->r_state = TCPS_CLOSE_WAIT;
13061 		rack->r_substate = rack_do_close_wait;
13062 		break;
13063 	case TCPS_FIN_WAIT_1:
13064 		rack_set_pace_segments(tp, rack, __LINE__, NULL);
13065 		rack->r_state = TCPS_FIN_WAIT_1;
13066 		rack->r_substate = rack_do_fin_wait_1;
13067 		break;
13068 	case TCPS_CLOSING:
13069 		rack_set_pace_segments(tp, rack, __LINE__, NULL);
13070 		rack->r_state = TCPS_CLOSING;
13071 		rack->r_substate = rack_do_closing;
13072 		break;
13073 	case TCPS_LAST_ACK:
13074 		rack_set_pace_segments(tp, rack, __LINE__, NULL);
13075 		rack->r_state = TCPS_LAST_ACK;
13076 		rack->r_substate = rack_do_lastack;
13077 		break;
13078 	case TCPS_FIN_WAIT_2:
13079 		rack_set_pace_segments(tp, rack, __LINE__, NULL);
13080 		rack->r_state = TCPS_FIN_WAIT_2;
13081 		rack->r_substate = rack_do_fin_wait_2;
13082 		break;
13083 	case TCPS_LISTEN:
13084 	case TCPS_CLOSED:
13085 	case TCPS_TIME_WAIT:
13086 	default:
13087 		break;
13088 	};
13089 	if (rack->r_use_cmp_ack && TCPS_HAVEESTABLISHED(tp->t_state))
13090 		rack->rc_inp->inp_flags2 |= INP_MBUF_ACKCMP;
13091 
13092 }
13093 
13094 static void
13095 rack_timer_audit(struct tcpcb *tp, struct tcp_rack *rack, struct sockbuf *sb)
13096 {
13097 	/*
13098 	 * We received an ack, and then did not
13099 	 * call send or were bounced out due to the
13100 	 * hpts was running. Now a timer is up as well, is
13101 	 * it the right timer?
13102 	 */
13103 	struct rack_sendmap *rsm;
13104 	int tmr_up;
13105 
13106 	tmr_up = rack->r_ctl.rc_hpts_flags & PACE_TMR_MASK;
13107 	if (rack->rc_in_persist && (tmr_up == PACE_TMR_PERSIT))
13108 		return;
13109 	rsm = TAILQ_FIRST(&rack->r_ctl.rc_tmap);
13110 	if (((rsm == NULL) || (tp->t_state < TCPS_ESTABLISHED)) &&
13111 	    (tmr_up == PACE_TMR_RXT)) {
13112 		/* Should be an RXT */
13113 		return;
13114 	}
13115 	if (rsm == NULL) {
13116 		/* Nothing outstanding? */
13117 		if (tp->t_flags & TF_DELACK) {
13118 			if (tmr_up == PACE_TMR_DELACK)
13119 				/* We are supposed to have delayed ack up and we do */
13120 				return;
13121 		} else if (sbavail(&tp->t_inpcb->inp_socket->so_snd) && (tmr_up == PACE_TMR_RXT)) {
13122 			/*
13123 			 * if we hit enobufs then we would expect the possiblity
13124 			 * of nothing outstanding and the RXT up (and the hptsi timer).
13125 			 */
13126 			return;
13127 		} else if (((V_tcp_always_keepalive ||
13128 			     rack->rc_inp->inp_socket->so_options & SO_KEEPALIVE) &&
13129 			    (tp->t_state <= TCPS_CLOSING)) &&
13130 			   (tmr_up == PACE_TMR_KEEP) &&
13131 			   (tp->snd_max == tp->snd_una)) {
13132 			/* We should have keep alive up and we do */
13133 			return;
13134 		}
13135 	}
13136 	if (SEQ_GT(tp->snd_max, tp->snd_una) &&
13137 		   ((tmr_up == PACE_TMR_TLP) ||
13138 		    (tmr_up == PACE_TMR_RACK) ||
13139 		    (tmr_up == PACE_TMR_RXT))) {
13140 		/*
13141 		 * Either a Rack, TLP or RXT is fine if  we
13142 		 * have outstanding data.
13143 		 */
13144 		return;
13145 	} else if (tmr_up == PACE_TMR_DELACK) {
13146 		/*
13147 		 * If the delayed ack was going to go off
13148 		 * before the rtx/tlp/rack timer were going to
13149 		 * expire, then that would be the timer in control.
13150 		 * Note we don't check the time here trusting the
13151 		 * code is correct.
13152 		 */
13153 		return;
13154 	}
13155 	/*
13156 	 * Ok the timer originally started is not what we want now.
13157 	 * We will force the hpts to be stopped if any, and restart
13158 	 * with the slot set to what was in the saved slot.
13159 	 */
13160 	if (rack->rc_inp->inp_in_hpts) {
13161 		if (rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT) {
13162 			uint32_t us_cts;
13163 
13164 			us_cts = tcp_get_usecs(NULL);
13165 			if (TSTMP_GT(rack->r_ctl.rc_last_output_to, us_cts)) {
13166 				rack->r_early = 1;
13167 				rack->r_ctl.rc_agg_early += (rack->r_ctl.rc_last_output_to - us_cts);
13168 			}
13169 			rack->r_ctl.rc_hpts_flags &= ~PACE_PKT_OUTPUT;
13170 		}
13171 		tcp_hpts_remove(tp->t_inpcb, HPTS_REMOVE_OUTPUT);
13172 	}
13173 	rack_timer_cancel(tp, rack, rack->r_ctl.rc_rcvtime, __LINE__);
13174 	rack_start_hpts_timer(rack, tp, tcp_get_usecs(NULL), 0, 0, 0);
13175 }
13176 
13177 
13178 static void
13179 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)
13180 {
13181 	if ((SEQ_LT(tp->snd_wl1, seq) ||
13182 	    (tp->snd_wl1 == seq && (SEQ_LT(tp->snd_wl2, ack) ||
13183 	    (tp->snd_wl2 == ack && tiwin > tp->snd_wnd))))) {
13184 		/* keep track of pure window updates */
13185 		if ((tp->snd_wl2 == ack) && (tiwin > tp->snd_wnd))
13186 			KMOD_TCPSTAT_INC(tcps_rcvwinupd);
13187 		tp->snd_wnd = tiwin;
13188 		rack_validate_fo_sendwin_up(tp, rack);
13189 		tp->snd_wl1 = seq;
13190 		tp->snd_wl2 = ack;
13191 		if (tp->snd_wnd > tp->max_sndwnd)
13192 			tp->max_sndwnd = tp->snd_wnd;
13193 	    rack->r_wanted_output = 1;
13194 	} else if ((tp->snd_wl2 == ack) && (tiwin < tp->snd_wnd)) {
13195 		tp->snd_wnd = tiwin;
13196 		rack_validate_fo_sendwin_up(tp, rack);
13197 		tp->snd_wl1 = seq;
13198 		tp->snd_wl2 = ack;
13199 	} else {
13200 		/* Not a valid win update */
13201 		return;
13202 	}
13203 	if (tp->snd_wnd > tp->max_sndwnd)
13204 		tp->max_sndwnd = tp->snd_wnd;
13205 	if (tp->snd_wnd < (tp->snd_max - high_seq)) {
13206 		/* The peer collapsed the window */
13207 		rack_collapsed_window(rack);
13208 	} else if (rack->rc_has_collapsed)
13209 		rack_un_collapse_window(rack);
13210 	/* Do we exit persists? */
13211 	if ((rack->rc_in_persist != 0) &&
13212 	    (tp->snd_wnd >= min((rack->r_ctl.rc_high_rwnd/2),
13213 				rack->r_ctl.rc_pace_min_segs))) {
13214 		rack_exit_persist(tp, rack, cts);
13215 	}
13216 	/* Do we enter persists? */
13217 	if ((rack->rc_in_persist == 0) &&
13218 	    (tp->snd_wnd < min((rack->r_ctl.rc_high_rwnd/2), rack->r_ctl.rc_pace_min_segs)) &&
13219 	    TCPS_HAVEESTABLISHED(tp->t_state) &&
13220 	    (tp->snd_max == tp->snd_una) &&
13221 	    sbavail(&tp->t_inpcb->inp_socket->so_snd) &&
13222 	    (sbavail(&tp->t_inpcb->inp_socket->so_snd) > tp->snd_wnd)) {
13223 		/*
13224 		 * Here the rwnd is less than
13225 		 * the pacing size, we are established,
13226 		 * nothing is outstanding, and there is
13227 		 * data to send. Enter persists.
13228 		 */
13229 		rack_enter_persist(tp, rack, rack->r_ctl.rc_rcvtime);
13230 	}
13231 }
13232 
13233 static void
13234 rack_log_input_packet(struct tcpcb *tp, struct tcp_rack *rack, struct tcp_ackent *ae, int ackval, uint32_t high_seq)
13235 {
13236 
13237 	if (tp->t_logstate != TCP_LOG_STATE_OFF) {
13238 		union tcp_log_stackspecific log;
13239 		struct timeval ltv;
13240 		char tcp_hdr_buf[60];
13241 		struct tcphdr *th;
13242 		struct timespec ts;
13243 		uint32_t orig_snd_una;
13244 		uint8_t xx = 0;
13245 
13246 #ifdef NETFLIX_HTTP_LOGGING
13247 		struct http_sendfile_track *http_req;
13248 
13249 		if (SEQ_GT(ae->ack, tp->snd_una)) {
13250 			http_req = tcp_http_find_req_for_seq(tp, (ae->ack-1));
13251 		} else {
13252 			http_req = tcp_http_find_req_for_seq(tp, ae->ack);
13253 		}
13254 #endif
13255 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
13256 		log.u_bbr.inhpts = rack->rc_inp->inp_in_hpts;
13257 		log.u_bbr.ininput = rack->rc_inp->inp_in_input;
13258 		if (rack->rack_no_prr == 0)
13259 			log.u_bbr.flex1 = rack->r_ctl.rc_prr_sndcnt;
13260 		else
13261 			log.u_bbr.flex1 = 0;
13262 		log.u_bbr.use_lt_bw = rack->r_ent_rec_ns;
13263 		log.u_bbr.use_lt_bw <<= 1;
13264 		log.u_bbr.use_lt_bw |= rack->r_might_revert;
13265 		log.u_bbr.flex2 = rack->r_ctl.rc_num_maps_alloced;
13266 		log.u_bbr.inflight = ctf_flight_size(tp, rack->r_ctl.rc_sacked);
13267 		log.u_bbr.pkts_out = tp->t_maxseg;
13268 		log.u_bbr.flex4 = rack->r_ctl.rc_hpts_flags;
13269 		log.u_bbr.flex7 = 1;
13270 		log.u_bbr.lost = ae->flags;
13271 		log.u_bbr.cwnd_gain = ackval;
13272 		log.u_bbr.pacing_gain = 0x2;
13273 		if (ae->flags & TSTMP_HDWR) {
13274 			/* Record the hardware timestamp if present */
13275 			log.u_bbr.flex3 = M_TSTMP;
13276 			ts.tv_sec = ae->timestamp / 1000000000;
13277 			ts.tv_nsec = ae->timestamp % 1000000000;
13278 			ltv.tv_sec = ts.tv_sec;
13279 			ltv.tv_usec = ts.tv_nsec / 1000;
13280 			log.u_bbr.lt_epoch = tcp_tv_to_usectick(&ltv);
13281 		} else if (ae->flags & TSTMP_LRO) {
13282 			/* Record the LRO the arrival timestamp */
13283 			log.u_bbr.flex3 = M_TSTMP_LRO;
13284 			ts.tv_sec = ae->timestamp / 1000000000;
13285 			ts.tv_nsec = ae->timestamp % 1000000000;
13286 			ltv.tv_sec = ts.tv_sec;
13287 			ltv.tv_usec = ts.tv_nsec / 1000;
13288 			log.u_bbr.flex5 = tcp_tv_to_usectick(&ltv);
13289 		}
13290 		log.u_bbr.timeStamp = tcp_get_usecs(&ltv);
13291 		/* Log the rcv time */
13292 		log.u_bbr.delRate = ae->timestamp;
13293 #ifdef NETFLIX_HTTP_LOGGING
13294 		log.u_bbr.applimited = tp->t_http_closed;
13295 		log.u_bbr.applimited <<= 8;
13296 		log.u_bbr.applimited |= tp->t_http_open;
13297 		log.u_bbr.applimited <<= 8;
13298 		log.u_bbr.applimited |= tp->t_http_req;
13299 		if (http_req) {
13300 			/* Copy out any client req info */
13301 			/* seconds */
13302 			log.u_bbr.pkt_epoch = (http_req->localtime / HPTS_USEC_IN_SEC);
13303 			/* useconds */
13304 			log.u_bbr.delivered = (http_req->localtime % HPTS_USEC_IN_SEC);
13305 			log.u_bbr.rttProp = http_req->timestamp;
13306 			log.u_bbr.cur_del_rate = http_req->start;
13307 			if (http_req->flags & TCP_HTTP_TRACK_FLG_OPEN) {
13308 				log.u_bbr.flex8 |= 1;
13309 			} else {
13310 				log.u_bbr.flex8 |= 2;
13311 				log.u_bbr.bw_inuse = http_req->end;
13312 			}
13313 			log.u_bbr.flex6 = http_req->start_seq;
13314 			if (http_req->flags & TCP_HTTP_TRACK_FLG_COMP) {
13315 				log.u_bbr.flex8 |= 4;
13316 				log.u_bbr.epoch = http_req->end_seq;
13317 			}
13318 		}
13319 #endif
13320 		memset(tcp_hdr_buf, 0, sizeof(tcp_hdr_buf));
13321 		th = (struct tcphdr *)tcp_hdr_buf;
13322 		th->th_seq = ae->seq;
13323 		th->th_ack = ae->ack;
13324 		th->th_win = ae->win;
13325 		/* Now fill in the ports */
13326 		th->th_sport = tp->t_inpcb->inp_fport;
13327 		th->th_dport = tp->t_inpcb->inp_lport;
13328 		th->th_flags = ae->flags & 0xff;
13329 		/* Now do we have a timestamp option? */
13330 		if (ae->flags & HAS_TSTMP) {
13331 			u_char *cp;
13332 			uint32_t val;
13333 
13334 			th->th_off = ((sizeof(struct tcphdr) + TCPOLEN_TSTAMP_APPA) >> 2);
13335 			cp = (u_char *)(th + 1);
13336 			*cp = TCPOPT_NOP;
13337 			cp++;
13338 			*cp = TCPOPT_NOP;
13339 			cp++;
13340 			*cp = TCPOPT_TIMESTAMP;
13341 			cp++;
13342 			*cp = TCPOLEN_TIMESTAMP;
13343 			cp++;
13344 			val = htonl(ae->ts_value);
13345 			bcopy((char *)&val,
13346 			      (char *)cp, sizeof(uint32_t));
13347 			val = htonl(ae->ts_echo);
13348 			bcopy((char *)&val,
13349 			      (char *)(cp + 4), sizeof(uint32_t));
13350 		} else
13351 			th->th_off = (sizeof(struct tcphdr) >> 2);
13352 
13353 		/*
13354 		 * For sane logging we need to play a little trick.
13355 		 * If the ack were fully processed we would have moved
13356 		 * snd_una to high_seq, but since compressed acks are
13357 		 * processed in two phases, at this point (logging) snd_una
13358 		 * won't be advanced. So we would see multiple acks showing
13359 		 * the advancement. We can prevent that by "pretending" that
13360 		 * snd_una was advanced and then un-advancing it so that the
13361 		 * logging code has the right value for tlb_snd_una.
13362 		 */
13363 		if (tp->snd_una != high_seq) {
13364 			orig_snd_una = tp->snd_una;
13365 			tp->snd_una = high_seq;
13366 			xx = 1;
13367 		} else
13368 			xx = 0;
13369 		TCP_LOG_EVENTP(tp, th,
13370 			       &tp->t_inpcb->inp_socket->so_rcv,
13371 			       &tp->t_inpcb->inp_socket->so_snd, TCP_LOG_IN, 0,
13372 			       0, &log, true, &ltv);
13373 		if (xx) {
13374 			tp->snd_una = orig_snd_una;
13375 		}
13376 	}
13377 
13378 }
13379 
13380 static int
13381 rack_do_compressed_ack_processing(struct tcpcb *tp, struct socket *so, struct mbuf *m, int nxt_pkt, struct timeval *tv)
13382 {
13383 	/*
13384 	 * Handle a "special" compressed ack mbuf. Each incoming
13385 	 * ack has only four possible dispositions:
13386 	 *
13387 	 * A) It moves the cum-ack forward
13388 	 * B) It is behind the cum-ack.
13389 	 * C) It is a window-update ack.
13390 	 * D) It is a dup-ack.
13391 	 *
13392 	 * Note that we can have between 1 -> TCP_COMP_ACK_ENTRIES
13393 	 * in the incoming mbuf. We also need to still pay attention
13394 	 * to nxt_pkt since there may be another packet after this
13395 	 * one.
13396 	 */
13397 #ifdef TCP_ACCOUNTING
13398 	uint64_t ts_val;
13399 	uint64_t rdstc;
13400 #endif
13401 	int segsiz;
13402 	struct timespec ts;
13403 	struct tcp_rack *rack;
13404 	struct tcp_ackent *ae;
13405 	uint32_t tiwin, ms_cts, cts, acked, acked_amount, high_seq, win_seq, the_win, win_upd_ack;
13406 	int cnt, i, did_out, ourfinisacked = 0;
13407 	struct tcpopt to_holder, *to = NULL;
13408 	int win_up_req = 0;
13409 	int nsegs = 0;
13410 	int under_pacing = 1;
13411 	int recovery = 0;
13412 	int idx;
13413 #ifdef TCP_ACCOUNTING
13414 	sched_pin();
13415 #endif
13416 	rack = (struct tcp_rack *)tp->t_fb_ptr;
13417 	if (rack->gp_ready &&
13418 	    (rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT))
13419 		under_pacing = 0;
13420 	else
13421 		under_pacing = 1;
13422 
13423 	if (rack->r_state != tp->t_state)
13424 		rack_set_state(tp, rack);
13425 	if ((tp->t_state >= TCPS_FIN_WAIT_1) &&
13426 	    (tp->t_flags & TF_GPUTINPROG)) {
13427 		/*
13428 		 * We have a goodput in progress
13429 		 * and we have entered a late state.
13430 		 * Do we have enough data in the sb
13431 		 * to handle the GPUT request?
13432 		 */
13433 		uint32_t bytes;
13434 
13435 		bytes = tp->gput_ack - tp->gput_seq;
13436 		if (SEQ_GT(tp->gput_seq, tp->snd_una))
13437 			bytes += tp->gput_seq - tp->snd_una;
13438 		if (bytes > sbavail(&tp->t_inpcb->inp_socket->so_snd)) {
13439 			/*
13440 			 * There are not enough bytes in the socket
13441 			 * buffer that have been sent to cover this
13442 			 * measurement. Cancel it.
13443 			 */
13444 			rack_log_pacing_delay_calc(rack, (tp->gput_ack - tp->gput_seq) /*flex2*/,
13445 						   rack->r_ctl.rc_gp_srtt /*flex1*/,
13446 						   tp->gput_seq,
13447 						   0, 0, 18, __LINE__, NULL, 0);
13448 			tp->t_flags &= ~TF_GPUTINPROG;
13449 		}
13450 	}
13451 	to = &to_holder;
13452 	to->to_flags = 0;
13453 	KASSERT((m->m_len >= sizeof(struct tcp_ackent)),
13454 		("tp:%p m_cmpack:%p with invalid len:%u", tp, m, m->m_len));
13455 	cnt = m->m_len / sizeof(struct tcp_ackent);
13456 	idx = cnt / 5;
13457 	if (idx >= MAX_NUM_OF_CNTS)
13458 		idx = MAX_NUM_OF_CNTS - 1;
13459 	counter_u64_add(rack_proc_comp_ack[idx], 1);
13460 	counter_u64_add(rack_multi_single_eq, cnt);
13461 	high_seq = tp->snd_una;
13462 	the_win = tp->snd_wnd;
13463 	win_seq = tp->snd_wl1;
13464 	win_upd_ack = tp->snd_wl2;
13465 	cts = tcp_tv_to_usectick(tv);
13466 	ms_cts = tcp_tv_to_mssectick(tv);
13467 	segsiz = ctf_fixed_maxseg(tp);
13468 	if ((rack->rc_gp_dyn_mul) &&
13469 	    (rack->use_fixed_rate == 0) &&
13470 	    (rack->rc_always_pace)) {
13471 		/* Check in on probertt */
13472 		rack_check_probe_rtt(rack, cts);
13473 	}
13474 	for (i = 0; i < cnt; i++) {
13475 #ifdef TCP_ACCOUNTING
13476 		ts_val = get_cyclecount();
13477 #endif
13478 		rack_clear_rate_sample(rack);
13479 		ae = ((mtod(m, struct tcp_ackent *)) + i);
13480 		/* Setup the window */
13481 		tiwin = ae->win << tp->snd_scale;
13482 		/* figure out the type of ack */
13483 		if (SEQ_LT(ae->ack, high_seq)) {
13484 			/* Case B*/
13485 			ae->ack_val_set = ACK_BEHIND;
13486 		} else if (SEQ_GT(ae->ack, high_seq)) {
13487 			/* Case A */
13488 			ae->ack_val_set = ACK_CUMACK;
13489 		} else if (tiwin == the_win) {
13490 			/* Case D */
13491 			ae->ack_val_set = ACK_DUPACK;
13492 		} else {
13493 			/* Case C */
13494 			ae->ack_val_set = ACK_RWND;
13495 		}
13496 		rack_log_input_packet(tp, rack, ae, ae->ack_val_set, high_seq);
13497 		/* Validate timestamp */
13498 		if (ae->flags & HAS_TSTMP) {
13499 			/* Setup for a timestamp */
13500 			to->to_flags = TOF_TS;
13501 			ae->ts_echo -= tp->ts_offset;
13502 			to->to_tsecr = ae->ts_echo;
13503 			to->to_tsval = ae->ts_value;
13504 			/*
13505 			 * If echoed timestamp is later than the current time, fall back to
13506 			 * non RFC1323 RTT calculation.  Normalize timestamp if syncookies
13507 			 * were used when this connection was established.
13508 			 */
13509 			if (TSTMP_GT(ae->ts_echo, ms_cts))
13510 				to->to_tsecr = 0;
13511 			if (tp->ts_recent &&
13512 			    TSTMP_LT(ae->ts_value, tp->ts_recent)) {
13513 				if (ctf_ts_check_ac(tp, (ae->flags & 0xff))) {
13514 #ifdef TCP_ACCOUNTING
13515 					rdstc = get_cyclecount();
13516 					if (rdstc > ts_val) {
13517 						counter_u64_add(tcp_proc_time[ae->ack_val_set] ,
13518 								(rdstc - ts_val));
13519 						if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
13520 							tp->tcp_proc_time[ae->ack_val_set] += (rdstc - ts_val);
13521 						}
13522 					}
13523 #endif
13524 					continue;
13525 				}
13526 			}
13527 			if (SEQ_LEQ(ae->seq, tp->last_ack_sent) &&
13528 			    SEQ_LEQ(tp->last_ack_sent, ae->seq)) {
13529 				tp->ts_recent_age = tcp_ts_getticks();
13530 				tp->ts_recent = ae->ts_value;
13531 			}
13532 		} else {
13533 			/* Setup for a no options */
13534 			to->to_flags = 0;
13535 		}
13536 		/* Update the rcv time and perform idle reduction possibly */
13537 		if  (tp->t_idle_reduce &&
13538 		     (tp->snd_max == tp->snd_una) &&
13539 		     ((ticks - tp->t_rcvtime) >= tp->t_rxtcur)) {
13540 			counter_u64_add(rack_input_idle_reduces, 1);
13541 			rack_cc_after_idle(rack, tp);
13542 		}
13543 		tp->t_rcvtime = ticks;
13544 		/* Now what about ECN? */
13545 		if (tp->t_flags2 & TF2_ECN_PERMIT) {
13546 			if (ae->flags & TH_CWR) {
13547 				tp->t_flags2 &= ~TF2_ECN_SND_ECE;
13548 				tp->t_flags |= TF_ACKNOW;
13549 			}
13550 			switch (ae->codepoint & IPTOS_ECN_MASK) {
13551 			case IPTOS_ECN_CE:
13552 				tp->t_flags2 |= TF2_ECN_SND_ECE;
13553 				KMOD_TCPSTAT_INC(tcps_ecn_ce);
13554 				break;
13555 			case IPTOS_ECN_ECT0:
13556 				KMOD_TCPSTAT_INC(tcps_ecn_ect0);
13557 				break;
13558 			case IPTOS_ECN_ECT1:
13559 				KMOD_TCPSTAT_INC(tcps_ecn_ect1);
13560 				break;
13561 			}
13562 
13563 			/* Process a packet differently from RFC3168. */
13564 			cc_ecnpkt_handler_flags(tp, ae->flags, ae->codepoint);
13565 			/* Congestion experienced. */
13566 			if (ae->flags & TH_ECE) {
13567 				rack_cong_signal(tp,  CC_ECN, ae->ack);
13568 			}
13569 		}
13570 #ifdef TCP_ACCOUNTING
13571 		/* Count for the specific type of ack in */
13572 		counter_u64_add(tcp_cnt_counters[ae->ack_val_set], 1);
13573 		if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
13574 			tp->tcp_cnt_counters[ae->ack_val_set]++;
13575 		}
13576 #endif
13577 		/*
13578 		 * Note how we could move up these in the determination
13579 		 * above, but we don't so that way the timestamp checks (and ECN)
13580 		 * is done first before we do any processing on the ACK.
13581 		 * The non-compressed path through the code has this
13582 		 * weakness (noted by @jtl) that it actually does some
13583 		 * processing before verifying the timestamp information.
13584 		 * We don't take that path here which is why we set
13585 		 * the ack_val_set first, do the timestamp and ecn
13586 		 * processing, and then look at what we have setup.
13587 		 */
13588 		if (ae->ack_val_set == ACK_BEHIND) {
13589 			/*
13590 			 * Case B flag reordering, if window is not closed
13591 			 * or it could be a keep-alive or persists
13592 			 */
13593 			if (SEQ_LT(ae->ack, tp->snd_una) && (sbspace(&so->so_rcv) > segsiz)) {
13594 				counter_u64_add(rack_reorder_seen, 1);
13595 				rack->r_ctl.rc_reorder_ts = tcp_tv_to_usectick(&rack->r_ctl.act_rcv_time);
13596 			}
13597 		} else if (ae->ack_val_set == ACK_DUPACK) {
13598 			/* Case D */
13599 			rack_strike_dupack(rack);
13600 		} else if (ae->ack_val_set == ACK_RWND) {
13601 			/* Case C */
13602 			win_up_req = 1;
13603 			win_upd_ack = ae->ack;
13604 			win_seq = ae->seq;
13605 			the_win = tiwin;
13606 			rack_do_win_updates(tp, rack, the_win, win_seq, win_upd_ack, cts, high_seq);
13607 		} else {
13608 			/* Case A */
13609 			if (SEQ_GT(ae->ack, tp->snd_max)) {
13610 				/*
13611 				 * We just send an ack since the incoming
13612 				 * ack is beyond the largest seq we sent.
13613 				 */
13614 				if ((tp->t_flags & TF_ACKNOW) == 0) {
13615 					ctf_ack_war_checks(tp, &rack->r_ctl.challenge_ack_ts, &rack->r_ctl.challenge_ack_cnt);
13616 					if (tp->t_flags && TF_ACKNOW)
13617 						rack->r_wanted_output = 1;
13618 				}
13619 			} else {
13620 				nsegs++;
13621 				/* If the window changed setup to update */
13622 				if (tiwin != tp->snd_wnd) {
13623 					win_upd_ack = ae->ack;
13624 					win_seq = ae->seq;
13625 					the_win = tiwin;
13626 					rack_do_win_updates(tp, rack, the_win, win_seq, win_upd_ack, cts, high_seq);
13627 				}
13628 #ifdef TCP_ACCOUNTING
13629 				/* Account for the acks */
13630 				if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
13631 					tp->tcp_cnt_counters[CNT_OF_ACKS_IN] += (((ae->ack - high_seq) + segsiz - 1) / segsiz);
13632 				}
13633 				counter_u64_add(tcp_cnt_counters[CNT_OF_ACKS_IN],
13634 						(((ae->ack - high_seq) + segsiz - 1) / segsiz));
13635 #endif
13636 				high_seq = ae->ack;
13637 				if (SEQ_GEQ(high_seq, rack->r_ctl.roundends)) {
13638 					rack->r_ctl.current_round++;
13639 					rack->r_ctl.roundends = tp->snd_max;
13640 					if (CC_ALGO(tp)->newround != NULL) {
13641 						CC_ALGO(tp)->newround(tp->ccv, rack->r_ctl.current_round);
13642 					}
13643 				}
13644 				/* Setup our act_rcv_time */
13645 				if ((ae->flags & TSTMP_LRO) || (ae->flags & TSTMP_HDWR)) {
13646 					ts.tv_sec = ae->timestamp / 1000000000;
13647 					ts.tv_nsec = ae->timestamp % 1000000000;
13648 					rack->r_ctl.act_rcv_time.tv_sec = ts.tv_sec;
13649 					rack->r_ctl.act_rcv_time.tv_usec = ts.tv_nsec/1000;
13650 				} else {
13651 					rack->r_ctl.act_rcv_time = *tv;
13652 				}
13653 				rack_process_to_cumack(tp, rack, ae->ack, cts, to);
13654 				if (rack->rc_dsack_round_seen) {
13655 					/* Is the dsack round over? */
13656 					if (SEQ_GEQ(ae->ack, rack->r_ctl.dsack_round_end)) {
13657 						/* Yes it is */
13658 						rack->rc_dsack_round_seen = 0;
13659 						rack_log_dsack_event(rack, 3, __LINE__, 0, 0);
13660 					}
13661 				}
13662 			}
13663 		}
13664 		/* And lets be sure to commit the rtt measurements for this ack */
13665 		tcp_rack_xmit_timer_commit(rack, tp);
13666 #ifdef TCP_ACCOUNTING
13667 		rdstc = get_cyclecount();
13668 		if (rdstc > ts_val) {
13669 			counter_u64_add(tcp_proc_time[ae->ack_val_set] , (rdstc - ts_val));
13670 			if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
13671 				tp->tcp_proc_time[ae->ack_val_set] += (rdstc - ts_val);
13672 				if (ae->ack_val_set == ACK_CUMACK)
13673 					tp->tcp_proc_time[CYC_HANDLE_MAP] += (rdstc - ts_val);
13674 			}
13675 		}
13676 #endif
13677 	}
13678 #ifdef TCP_ACCOUNTING
13679 	ts_val = get_cyclecount();
13680 #endif
13681 	acked_amount = acked = (high_seq - tp->snd_una);
13682 	if (acked) {
13683 		if (rack->sack_attack_disable == 0)
13684 			rack_do_decay(rack);
13685 		if (acked >= segsiz) {
13686 			/*
13687 			 * You only get credit for
13688 			 * MSS and greater (and you get extra
13689 			 * credit for larger cum-ack moves).
13690 			 */
13691 			int ac;
13692 
13693 			ac = acked / segsiz;
13694 			rack->r_ctl.ack_count += ac;
13695 			counter_u64_add(rack_ack_total, ac);
13696 		}
13697 		if (rack->r_ctl.ack_count > 0xfff00000) {
13698 			/*
13699 			 * reduce the number to keep us under
13700 			 * a uint32_t.
13701 			 */
13702 			rack->r_ctl.ack_count /= 2;
13703 			rack->r_ctl.sack_count /= 2;
13704 		}
13705 		if (tp->t_flags & TF_NEEDSYN) {
13706 			/*
13707 			 * T/TCP: Connection was half-synchronized, and our SYN has
13708 			 * been ACK'd (so connection is now fully synchronized).  Go
13709 			 * to non-starred state, increment snd_una for ACK of SYN,
13710 			 * and check if we can do window scaling.
13711 			 */
13712 			tp->t_flags &= ~TF_NEEDSYN;
13713 			tp->snd_una++;
13714 			acked_amount = acked = (high_seq - tp->snd_una);
13715 		}
13716 		if (acked > sbavail(&so->so_snd))
13717 			acked_amount = sbavail(&so->so_snd);
13718 #ifdef NETFLIX_EXP_DETECTION
13719 		/*
13720 		 * We only care on a cum-ack move if we are in a sack-disabled
13721 		 * state. We have already added in to the ack_count, and we never
13722 		 * would disable on a cum-ack move, so we only care to do the
13723 		 * detection if it may "undo" it, i.e. we were in disabled already.
13724 		 */
13725 		if (rack->sack_attack_disable)
13726 			rack_do_detection(tp, rack, acked_amount, segsiz);
13727 #endif
13728 		if (IN_FASTRECOVERY(tp->t_flags) &&
13729 		    (rack->rack_no_prr == 0))
13730 			rack_update_prr(tp, rack, acked_amount, high_seq);
13731 		if (IN_RECOVERY(tp->t_flags)) {
13732 			if (SEQ_LT(high_seq, tp->snd_recover) &&
13733 			    (SEQ_LT(high_seq, tp->snd_max))) {
13734 				tcp_rack_partialack(tp);
13735 			} else {
13736 				rack_post_recovery(tp, high_seq);
13737 				recovery = 1;
13738 			}
13739 		}
13740 		/* Handle the rack-log-ack part (sendmap) */
13741 		if ((sbused(&so->so_snd) == 0) &&
13742 		    (acked > acked_amount) &&
13743 		    (tp->t_state >= TCPS_FIN_WAIT_1) &&
13744 		    (tp->t_flags & TF_SENTFIN)) {
13745 			/*
13746 			 * We must be sure our fin
13747 			 * was sent and acked (we can be
13748 			 * in FIN_WAIT_1 without having
13749 			 * sent the fin).
13750 			 */
13751 			ourfinisacked = 1;
13752 			/*
13753 			 * Lets make sure snd_una is updated
13754 			 * since most likely acked_amount = 0 (it
13755 			 * should be).
13756 			 */
13757 			tp->snd_una = high_seq;
13758 		}
13759 		/* Did we make a RTO error? */
13760 		if ((tp->t_flags & TF_PREVVALID) &&
13761 		    ((tp->t_flags & TF_RCVD_TSTMP) == 0)) {
13762 			tp->t_flags &= ~TF_PREVVALID;
13763 			if (tp->t_rxtshift == 1 &&
13764 			    (int)(ticks - tp->t_badrxtwin) < 0)
13765 				rack_cong_signal(tp, CC_RTO_ERR, high_seq);
13766 		}
13767 		/* Handle the data in the socket buffer */
13768 		KMOD_TCPSTAT_ADD(tcps_rcvackpack, 1);
13769 		KMOD_TCPSTAT_ADD(tcps_rcvackbyte, acked);
13770 		if (acked_amount > 0) {
13771 			struct mbuf *mfree;
13772 
13773 			rack_ack_received(tp, rack, high_seq, nsegs, CC_ACK, recovery);
13774 			SOCKBUF_LOCK(&so->so_snd);
13775 			mfree = sbcut_locked(&so->so_snd, acked_amount);
13776 			tp->snd_una = high_seq;
13777 			/* Note we want to hold the sb lock through the sendmap adjust */
13778 			rack_adjust_sendmap(rack, &so->so_snd, tp->snd_una);
13779 			/* Wake up the socket if we have room to write more */
13780 			rack_log_wakeup(tp,rack, &so->so_snd, acked, 2);
13781 			sowwakeup_locked(so);
13782 			m_freem(mfree);
13783 		}
13784 		/* update progress */
13785 		tp->t_acktime = ticks;
13786 		rack_log_progress_event(rack, tp, tp->t_acktime,
13787 					PROGRESS_UPDATE, __LINE__);
13788 		/* Clear out shifts and such */
13789 		tp->t_rxtshift = 0;
13790 		RACK_TCPT_RANGESET(tp->t_rxtcur, RACK_REXMTVAL(tp),
13791 				   rack_rto_min, rack_rto_max, rack->r_ctl.timer_slop);
13792 		rack->rc_tlp_in_progress = 0;
13793 		rack->r_ctl.rc_tlp_cnt_out = 0;
13794 		/* Send recover and snd_nxt must be dragged along */
13795 		if (SEQ_GT(tp->snd_una, tp->snd_recover))
13796 			tp->snd_recover = tp->snd_una;
13797 		if (SEQ_LT(tp->snd_nxt, tp->snd_una))
13798 			tp->snd_nxt = tp->snd_una;
13799 		/*
13800 		 * If the RXT timer is running we want to
13801 		 * stop it, so we can restart a TLP (or new RXT).
13802 		 */
13803 		if (rack->r_ctl.rc_hpts_flags & PACE_TMR_RXT)
13804 			rack_timer_cancel(tp, rack, rack->r_ctl.rc_rcvtime, __LINE__);
13805 #ifdef NETFLIX_HTTP_LOGGING
13806 		tcp_http_check_for_comp(rack->rc_tp, high_seq);
13807 #endif
13808 		tp->snd_wl2 = high_seq;
13809 		tp->t_dupacks = 0;
13810 		if (under_pacing &&
13811 		    (rack->use_fixed_rate == 0) &&
13812 		    (rack->in_probe_rtt == 0) &&
13813 		    rack->rc_gp_dyn_mul &&
13814 		    rack->rc_always_pace) {
13815 			/* Check if we are dragging bottom */
13816 			rack_check_bottom_drag(tp, rack, so, acked);
13817 		}
13818 		if (tp->snd_una == tp->snd_max) {
13819 			tp->t_flags &= ~TF_PREVVALID;
13820 			rack->r_ctl.retran_during_recovery = 0;
13821 			rack->r_ctl.dsack_byte_cnt = 0;
13822 			rack->r_ctl.rc_went_idle_time = tcp_get_usecs(NULL);
13823 			if (rack->r_ctl.rc_went_idle_time == 0)
13824 				rack->r_ctl.rc_went_idle_time = 1;
13825 			rack_log_progress_event(rack, tp, 0, PROGRESS_CLEAR, __LINE__);
13826 			if (sbavail(&tp->t_inpcb->inp_socket->so_snd) == 0)
13827 				tp->t_acktime = 0;
13828 			/* Set so we might enter persists... */
13829 			rack->r_wanted_output = 1;
13830 			rack_timer_cancel(tp, rack, rack->r_ctl.rc_rcvtime, __LINE__);
13831 			sack_filter_clear(&rack->r_ctl.rack_sf, tp->snd_una);
13832 			if ((tp->t_state >= TCPS_FIN_WAIT_1) &&
13833 			    (sbavail(&so->so_snd) == 0) &&
13834 			    (tp->t_flags2 & TF2_DROP_AF_DATA)) {
13835 				/*
13836 				 * The socket was gone and the
13837 				 * peer sent data (not now in the past), time to
13838 				 * reset him.
13839 				 */
13840 				rack_timer_cancel(tp, rack, rack->r_ctl.rc_rcvtime, __LINE__);
13841 				/* tcp_close will kill the inp pre-log the Reset */
13842 				tcp_log_end_status(tp, TCP_EI_STATUS_SERVER_RST);
13843 #ifdef TCP_ACCOUNTING
13844 				rdstc = get_cyclecount();
13845 				if (rdstc > ts_val) {
13846 					counter_u64_add(tcp_proc_time[ACK_CUMACK] , (rdstc - ts_val));
13847 					if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
13848 						tp->tcp_proc_time[ACK_CUMACK] += (rdstc - ts_val);
13849 						tp->tcp_proc_time[CYC_HANDLE_ACK] += (rdstc - ts_val);
13850 					}
13851 				}
13852 #endif
13853 				m_freem(m);
13854 				tp = tcp_close(tp);
13855 				if (tp == NULL) {
13856 #ifdef TCP_ACCOUNTING
13857 					sched_unpin();
13858 #endif
13859 					return (1);
13860 				}
13861 				/*
13862 				 * We would normally do drop-with-reset which would
13863 				 * send back a reset. We can't since we don't have
13864 				 * all the needed bits. Instead lets arrange for
13865 				 * a call to tcp_output(). That way since we
13866 				 * are in the closed state we will generate a reset.
13867 				 *
13868 				 * Note if tcp_accounting is on we don't unpin since
13869 				 * we do that after the goto label.
13870 				 */
13871 				goto send_out_a_rst;
13872 			}
13873 			if ((sbused(&so->so_snd) == 0) &&
13874 			    (tp->t_state >= TCPS_FIN_WAIT_1) &&
13875 			    (tp->t_flags & TF_SENTFIN)) {
13876 				/*
13877 				 * If we can't receive any more data, then closing user can
13878 				 * proceed. Starting the timer is contrary to the
13879 				 * specification, but if we don't get a FIN we'll hang
13880 				 * forever.
13881 				 *
13882 				 */
13883 				if (so->so_rcv.sb_state & SBS_CANTRCVMORE) {
13884 					soisdisconnected(so);
13885 					tcp_timer_activate(tp, TT_2MSL,
13886 							   (tcp_fast_finwait2_recycle ?
13887 							    tcp_finwait2_timeout :
13888 							    TP_MAXIDLE(tp)));
13889 				}
13890 				if (ourfinisacked == 0) {
13891 					/*
13892 					 * We don't change to fin-wait-2 if we have our fin acked
13893 					 * which means we are probably in TCPS_CLOSING.
13894 					 */
13895 					tcp_state_change(tp, TCPS_FIN_WAIT_2);
13896 				}
13897 			}
13898 		}
13899 		/* Wake up the socket if we have room to write more */
13900 		if (sbavail(&so->so_snd)) {
13901 			rack->r_wanted_output = 1;
13902 			if (ctf_progress_timeout_check(tp, true)) {
13903 				rack_log_progress_event((struct tcp_rack *)tp->t_fb_ptr,
13904 							tp, tick, PROGRESS_DROP, __LINE__);
13905 				tcp_set_inp_to_drop(tp->t_inpcb, ETIMEDOUT);
13906 				/*
13907 				 * We cheat here and don't send a RST, we should send one
13908 				 * when the pacer drops the connection.
13909 				 */
13910 #ifdef TCP_ACCOUNTING
13911 				rdstc = get_cyclecount();
13912 				if (rdstc > ts_val) {
13913 					counter_u64_add(tcp_proc_time[ACK_CUMACK] , (rdstc - ts_val));
13914 					if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
13915 						tp->tcp_proc_time[ACK_CUMACK] += (rdstc - ts_val);
13916 						tp->tcp_proc_time[CYC_HANDLE_ACK] += (rdstc - ts_val);
13917 					}
13918 				}
13919 				sched_unpin();
13920 #endif
13921 				INP_WUNLOCK(rack->rc_inp);
13922 				m_freem(m);
13923 				return (1);
13924 			}
13925 		}
13926 		if (ourfinisacked) {
13927 			switch(tp->t_state) {
13928 			case TCPS_CLOSING:
13929 #ifdef TCP_ACCOUNTING
13930 				rdstc = get_cyclecount();
13931 				if (rdstc > ts_val) {
13932 					counter_u64_add(tcp_proc_time[ACK_CUMACK] ,
13933 							(rdstc - ts_val));
13934 					if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
13935 						tp->tcp_proc_time[ACK_CUMACK] += (rdstc - ts_val);
13936 						tp->tcp_proc_time[CYC_HANDLE_ACK] += (rdstc - ts_val);
13937 					}
13938 				}
13939 				sched_unpin();
13940 #endif
13941 				tcp_twstart(tp);
13942 				m_freem(m);
13943 				return (1);
13944 				break;
13945 			case TCPS_LAST_ACK:
13946 #ifdef TCP_ACCOUNTING
13947 				rdstc = get_cyclecount();
13948 				if (rdstc > ts_val) {
13949 					counter_u64_add(tcp_proc_time[ACK_CUMACK] ,
13950 							(rdstc - ts_val));
13951 					if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
13952 						tp->tcp_proc_time[ACK_CUMACK] += (rdstc - ts_val);
13953 						tp->tcp_proc_time[CYC_HANDLE_ACK] += (rdstc - ts_val);
13954 					}
13955 				}
13956 				sched_unpin();
13957 #endif
13958 				tp = tcp_close(tp);
13959 				ctf_do_drop(m, tp);
13960 				return (1);
13961 				break;
13962 			case TCPS_FIN_WAIT_1:
13963 #ifdef TCP_ACCOUNTING
13964 				rdstc = get_cyclecount();
13965 				if (rdstc > ts_val) {
13966 					counter_u64_add(tcp_proc_time[ACK_CUMACK] ,
13967 							(rdstc - ts_val));
13968 					if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
13969 						tp->tcp_proc_time[ACK_CUMACK] += (rdstc - ts_val);
13970 						tp->tcp_proc_time[CYC_HANDLE_ACK] += (rdstc - ts_val);
13971 					}
13972 				}
13973 #endif
13974 				if (so->so_rcv.sb_state & SBS_CANTRCVMORE) {
13975 					soisdisconnected(so);
13976 					tcp_timer_activate(tp, TT_2MSL,
13977 							   (tcp_fast_finwait2_recycle ?
13978 							    tcp_finwait2_timeout :
13979 							    TP_MAXIDLE(tp)));
13980 				}
13981 				tcp_state_change(tp, TCPS_FIN_WAIT_2);
13982 				break;
13983 			default:
13984 				break;
13985 			}
13986 		}
13987 		if (rack->r_fast_output) {
13988 			/*
13989 			 * We re doing fast output.. can we expand that?
13990 			 */
13991 			rack_gain_for_fastoutput(rack, tp, so, acked_amount);
13992 		}
13993 #ifdef TCP_ACCOUNTING
13994 		rdstc = get_cyclecount();
13995 		if (rdstc > ts_val) {
13996 			counter_u64_add(tcp_proc_time[ACK_CUMACK] , (rdstc - ts_val));
13997 			if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
13998 				tp->tcp_proc_time[ACK_CUMACK] += (rdstc - ts_val);
13999 				tp->tcp_proc_time[CYC_HANDLE_ACK] += (rdstc - ts_val);
14000 			}
14001 		}
14002 
14003 	} else if (win_up_req) {
14004 		rdstc = get_cyclecount();
14005 		if (rdstc > ts_val) {
14006 			counter_u64_add(tcp_proc_time[ACK_RWND] , (rdstc - ts_val));
14007 			if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
14008 				tp->tcp_proc_time[ACK_RWND] += (rdstc - ts_val);
14009 			}
14010 		}
14011 #endif
14012 	}
14013 	/* Now is there a next packet, if so we are done */
14014 	m_freem(m);
14015 	did_out = 0;
14016 	if (nxt_pkt) {
14017 #ifdef TCP_ACCOUNTING
14018 		sched_unpin();
14019 #endif
14020 		rack_log_doseg_done(rack, cts, nxt_pkt, did_out, 5, nsegs);
14021 		return (0);
14022 	}
14023 	rack_handle_might_revert(tp, rack);
14024 	ctf_calc_rwin(so, tp);
14025 	if ((rack->r_wanted_output != 0) || (rack->r_fast_output != 0)) {
14026 	send_out_a_rst:
14027 		(void)tp->t_fb->tfb_tcp_output(tp);
14028 		did_out = 1;
14029 	}
14030 	rack_free_trim(rack);
14031 #ifdef TCP_ACCOUNTING
14032 	sched_unpin();
14033 #endif
14034 	rack_timer_audit(tp, rack, &so->so_snd);
14035 	rack_log_doseg_done(rack, cts, nxt_pkt, did_out, 6, nsegs);
14036 	return (0);
14037 }
14038 
14039 
14040 static int
14041 rack_do_segment_nounlock(struct mbuf *m, struct tcphdr *th, struct socket *so,
14042     struct tcpcb *tp, int32_t drop_hdrlen, int32_t tlen, uint8_t iptos,
14043     int32_t nxt_pkt, struct timeval *tv)
14044 {
14045 #ifdef TCP_ACCOUNTING
14046 	uint64_t ts_val;
14047 #endif
14048 	int32_t thflags, retval, did_out = 0;
14049 	int32_t way_out = 0;
14050 	/*
14051 	 * cts - is the current time from tv (caller gets ts) in microseconds.
14052 	 * ms_cts - is the current time from tv in milliseconds.
14053 	 * us_cts - is the time that LRO or hardware actually got the packet in microseconds.
14054 	 */
14055 	uint32_t cts, us_cts, ms_cts;
14056 	uint32_t tiwin;
14057 	struct timespec ts;
14058 	struct tcpopt to;
14059 	struct tcp_rack *rack;
14060 	struct rack_sendmap *rsm;
14061 	int32_t prev_state = 0;
14062 #ifdef TCP_ACCOUNTING
14063 	int ack_val_set = 0xf;
14064 #endif
14065 	int nsegs;
14066 	/*
14067 	 * tv passed from common code is from either M_TSTMP_LRO or
14068 	 * tcp_get_usecs() if no LRO m_pkthdr timestamp is present.
14069 	 */
14070 	rack = (struct tcp_rack *)tp->t_fb_ptr;
14071 	if (m->m_flags & M_ACKCMP) {
14072 		return (rack_do_compressed_ack_processing(tp, so, m, nxt_pkt, tv));
14073 	}
14074 	if (m->m_flags & M_ACKCMP) {
14075 		panic("Impossible reach m has ackcmp? m:%p tp:%p", m, tp);
14076 	}
14077 	cts = tcp_tv_to_usectick(tv);
14078 	ms_cts =  tcp_tv_to_mssectick(tv);
14079 	nsegs = m->m_pkthdr.lro_nsegs;
14080 	counter_u64_add(rack_proc_non_comp_ack, 1);
14081 	thflags = th->th_flags;
14082 #ifdef TCP_ACCOUNTING
14083 	sched_pin();
14084 	if (thflags & TH_ACK)
14085 		ts_val = get_cyclecount();
14086 #endif
14087 	if ((m->m_flags & M_TSTMP) ||
14088 	    (m->m_flags & M_TSTMP_LRO)) {
14089 		mbuf_tstmp2timespec(m, &ts);
14090 		rack->r_ctl.act_rcv_time.tv_sec = ts.tv_sec;
14091 		rack->r_ctl.act_rcv_time.tv_usec = ts.tv_nsec/1000;
14092 	} else
14093 		rack->r_ctl.act_rcv_time = *tv;
14094 	kern_prefetch(rack, &prev_state);
14095 	prev_state = 0;
14096 	/*
14097 	 * Unscale the window into a 32-bit value. For the SYN_SENT state
14098 	 * the scale is zero.
14099 	 */
14100 	tiwin = th->th_win << tp->snd_scale;
14101 #ifdef TCP_ACCOUNTING
14102 	if (thflags & TH_ACK) {
14103 		/*
14104 		 * We have a tradeoff here. We can either do what we are
14105 		 * doing i.e. pinning to this CPU and then doing the accounting
14106 		 * <or> we could do a critical enter, setup the rdtsc and cpu
14107 		 * as in below, and then validate we are on the same CPU on
14108 		 * exit. I have choosen to not do the critical enter since
14109 		 * that often will gain you a context switch, and instead lock
14110 		 * us (line above this if) to the same CPU with sched_pin(). This
14111 		 * means we may be context switched out for a higher priority
14112 		 * interupt but we won't be moved to another CPU.
14113 		 *
14114 		 * If this occurs (which it won't very often since we most likely
14115 		 * are running this code in interupt context and only a higher
14116 		 * priority will bump us ... clock?) we will falsely add in
14117 		 * to the time the interupt processing time plus the ack processing
14118 		 * time. This is ok since its a rare event.
14119 		 */
14120 		ack_val_set = tcp_do_ack_accounting(tp, th, &to, tiwin,
14121 						    ctf_fixed_maxseg(tp));
14122 	}
14123 #endif
14124 	/*
14125 	 * Parse options on any incoming segment.
14126 	 */
14127 	memset(&to, 0, sizeof(to));
14128 	tcp_dooptions(&to, (u_char *)(th + 1),
14129 	    (th->th_off << 2) - sizeof(struct tcphdr),
14130 	    (thflags & TH_SYN) ? TO_SYN : 0);
14131 	NET_EPOCH_ASSERT();
14132 	INP_WLOCK_ASSERT(tp->t_inpcb);
14133 	KASSERT(tp->t_state > TCPS_LISTEN, ("%s: TCPS_LISTEN",
14134 	    __func__));
14135 	KASSERT(tp->t_state != TCPS_TIME_WAIT, ("%s: TCPS_TIME_WAIT",
14136 	    __func__));
14137 	if ((tp->t_state >= TCPS_FIN_WAIT_1) &&
14138 	    (tp->t_flags & TF_GPUTINPROG)) {
14139 		/*
14140 		 * We have a goodput in progress
14141 		 * and we have entered a late state.
14142 		 * Do we have enough data in the sb
14143 		 * to handle the GPUT request?
14144 		 */
14145 		uint32_t bytes;
14146 
14147 		bytes = tp->gput_ack - tp->gput_seq;
14148 		if (SEQ_GT(tp->gput_seq, tp->snd_una))
14149 			bytes += tp->gput_seq - tp->snd_una;
14150 		if (bytes > sbavail(&tp->t_inpcb->inp_socket->so_snd)) {
14151 			/*
14152 			 * There are not enough bytes in the socket
14153 			 * buffer that have been sent to cover this
14154 			 * measurement. Cancel it.
14155 			 */
14156 			rack_log_pacing_delay_calc(rack, (tp->gput_ack - tp->gput_seq) /*flex2*/,
14157 						   rack->r_ctl.rc_gp_srtt /*flex1*/,
14158 						   tp->gput_seq,
14159 						   0, 0, 18, __LINE__, NULL, 0);
14160 			tp->t_flags &= ~TF_GPUTINPROG;
14161 		}
14162 	}
14163 	if (tp->t_logstate != TCP_LOG_STATE_OFF) {
14164 		union tcp_log_stackspecific log;
14165 		struct timeval ltv;
14166 #ifdef NETFLIX_HTTP_LOGGING
14167 		struct http_sendfile_track *http_req;
14168 
14169 		if (SEQ_GT(th->th_ack, tp->snd_una)) {
14170 			http_req = tcp_http_find_req_for_seq(tp, (th->th_ack-1));
14171 		} else {
14172 			http_req = tcp_http_find_req_for_seq(tp, th->th_ack);
14173 		}
14174 #endif
14175 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
14176 		log.u_bbr.inhpts = rack->rc_inp->inp_in_hpts;
14177 		log.u_bbr.ininput = rack->rc_inp->inp_in_input;
14178 		if (rack->rack_no_prr == 0)
14179 			log.u_bbr.flex1 = rack->r_ctl.rc_prr_sndcnt;
14180 		else
14181 			log.u_bbr.flex1 = 0;
14182 		log.u_bbr.use_lt_bw = rack->r_ent_rec_ns;
14183 		log.u_bbr.use_lt_bw <<= 1;
14184 		log.u_bbr.use_lt_bw |= rack->r_might_revert;
14185 		log.u_bbr.flex2 = rack->r_ctl.rc_num_maps_alloced;
14186 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
14187 		log.u_bbr.pkts_out = rack->rc_tp->t_maxseg;
14188 		log.u_bbr.flex3 = m->m_flags;
14189 		log.u_bbr.flex4 = rack->r_ctl.rc_hpts_flags;
14190 		log.u_bbr.lost = thflags;
14191 		log.u_bbr.pacing_gain = 0x1;
14192 #ifdef TCP_ACCOUNTING
14193 		log.u_bbr.cwnd_gain = ack_val_set;
14194 #endif
14195 		log.u_bbr.flex7 = 2;
14196 		if (m->m_flags & M_TSTMP) {
14197 			/* Record the hardware timestamp if present */
14198 			mbuf_tstmp2timespec(m, &ts);
14199 			ltv.tv_sec = ts.tv_sec;
14200 			ltv.tv_usec = ts.tv_nsec / 1000;
14201 			log.u_bbr.lt_epoch = tcp_tv_to_usectick(&ltv);
14202 		} else if (m->m_flags & M_TSTMP_LRO) {
14203 			/* Record the LRO the arrival timestamp */
14204 			mbuf_tstmp2timespec(m, &ts);
14205 			ltv.tv_sec = ts.tv_sec;
14206 			ltv.tv_usec = ts.tv_nsec / 1000;
14207 			log.u_bbr.flex5 = tcp_tv_to_usectick(&ltv);
14208 		}
14209 		log.u_bbr.timeStamp = tcp_get_usecs(&ltv);
14210 		/* Log the rcv time */
14211 		log.u_bbr.delRate = m->m_pkthdr.rcv_tstmp;
14212 #ifdef NETFLIX_HTTP_LOGGING
14213 		log.u_bbr.applimited = tp->t_http_closed;
14214 		log.u_bbr.applimited <<= 8;
14215 		log.u_bbr.applimited |= tp->t_http_open;
14216 		log.u_bbr.applimited <<= 8;
14217 		log.u_bbr.applimited |= tp->t_http_req;
14218 		if (http_req) {
14219 			/* Copy out any client req info */
14220 			/* seconds */
14221 			log.u_bbr.pkt_epoch = (http_req->localtime / HPTS_USEC_IN_SEC);
14222 			/* useconds */
14223 			log.u_bbr.delivered = (http_req->localtime % HPTS_USEC_IN_SEC);
14224 			log.u_bbr.rttProp = http_req->timestamp;
14225 			log.u_bbr.cur_del_rate = http_req->start;
14226 			if (http_req->flags & TCP_HTTP_TRACK_FLG_OPEN) {
14227 				log.u_bbr.flex8 |= 1;
14228 			} else {
14229 				log.u_bbr.flex8 |= 2;
14230 				log.u_bbr.bw_inuse = http_req->end;
14231 			}
14232 			log.u_bbr.flex6 = http_req->start_seq;
14233 			if (http_req->flags & TCP_HTTP_TRACK_FLG_COMP) {
14234 				log.u_bbr.flex8 |= 4;
14235 				log.u_bbr.epoch = http_req->end_seq;
14236 			}
14237 		}
14238 #endif
14239 		TCP_LOG_EVENTP(tp, th, &so->so_rcv, &so->so_snd, TCP_LOG_IN, 0,
14240 		    tlen, &log, true, &ltv);
14241 	}
14242 	if ((thflags & TH_SYN) && (thflags & TH_FIN) && V_drop_synfin) {
14243 		way_out = 4;
14244 		retval = 0;
14245 		m_freem(m);
14246 		goto done_with_input;
14247 	}
14248 	/*
14249 	 * If a segment with the ACK-bit set arrives in the SYN-SENT state
14250 	 * check SEQ.ACK first as described on page 66 of RFC 793, section 3.9.
14251 	 */
14252 	if ((tp->t_state == TCPS_SYN_SENT) && (thflags & TH_ACK) &&
14253 	    (SEQ_LEQ(th->th_ack, tp->iss) || SEQ_GT(th->th_ack, tp->snd_max))) {
14254 		tcp_log_end_status(tp, TCP_EI_STATUS_RST_IN_FRONT);
14255 		ctf_do_dropwithreset(m, tp, th, BANDLIM_RST_OPENPORT, tlen);
14256 #ifdef TCP_ACCOUNTING
14257 		sched_unpin();
14258 #endif
14259 		return (1);
14260 	}
14261 	/*
14262 	 * If timestamps were negotiated during SYN/ACK and a
14263 	 * segment without a timestamp is received, silently drop
14264 	 * the segment, unless it is a RST segment or missing timestamps are
14265 	 * tolerated.
14266 	 * See section 3.2 of RFC 7323.
14267 	 */
14268 	if ((tp->t_flags & TF_RCVD_TSTMP) && !(to.to_flags & TOF_TS) &&
14269 	    ((thflags & TH_RST) == 0) && (V_tcp_tolerate_missing_ts == 0)) {
14270 		way_out = 5;
14271 		retval = 0;
14272 		m_freem(m);
14273 		goto done_with_input;
14274 	}
14275 
14276 	/*
14277 	 * Segment received on connection. Reset idle time and keep-alive
14278 	 * timer. XXX: This should be done after segment validation to
14279 	 * ignore broken/spoofed segs.
14280 	 */
14281 	if  (tp->t_idle_reduce &&
14282 	     (tp->snd_max == tp->snd_una) &&
14283 	     ((ticks - tp->t_rcvtime) >= tp->t_rxtcur)) {
14284 		counter_u64_add(rack_input_idle_reduces, 1);
14285 		rack_cc_after_idle(rack, tp);
14286 	}
14287 	tp->t_rcvtime = ticks;
14288 #ifdef STATS
14289 	stats_voi_update_abs_ulong(tp->t_stats, VOI_TCP_FRWIN, tiwin);
14290 #endif
14291 	if (tiwin > rack->r_ctl.rc_high_rwnd)
14292 		rack->r_ctl.rc_high_rwnd = tiwin;
14293 	/*
14294 	 * TCP ECN processing. XXXJTL: If we ever use ECN, we need to move
14295 	 * this to occur after we've validated the segment.
14296 	 */
14297 	if (tp->t_flags2 & TF2_ECN_PERMIT) {
14298 		if (thflags & TH_CWR) {
14299 			tp->t_flags2 &= ~TF2_ECN_SND_ECE;
14300 			tp->t_flags |= TF_ACKNOW;
14301 		}
14302 		switch (iptos & IPTOS_ECN_MASK) {
14303 		case IPTOS_ECN_CE:
14304 			tp->t_flags2 |= TF2_ECN_SND_ECE;
14305 			KMOD_TCPSTAT_INC(tcps_ecn_ce);
14306 			break;
14307 		case IPTOS_ECN_ECT0:
14308 			KMOD_TCPSTAT_INC(tcps_ecn_ect0);
14309 			break;
14310 		case IPTOS_ECN_ECT1:
14311 			KMOD_TCPSTAT_INC(tcps_ecn_ect1);
14312 			break;
14313 		}
14314 
14315 		/* Process a packet differently from RFC3168. */
14316 		cc_ecnpkt_handler(tp, th, iptos);
14317 
14318 		/* Congestion experienced. */
14319 		if (thflags & TH_ECE) {
14320 			rack_cong_signal(tp, CC_ECN, th->th_ack);
14321 		}
14322 	}
14323 
14324 	/*
14325 	 * If echoed timestamp is later than the current time, fall back to
14326 	 * non RFC1323 RTT calculation.  Normalize timestamp if syncookies
14327 	 * were used when this connection was established.
14328 	 */
14329 	if ((to.to_flags & TOF_TS) && (to.to_tsecr != 0)) {
14330 		to.to_tsecr -= tp->ts_offset;
14331 		if (TSTMP_GT(to.to_tsecr, ms_cts))
14332 			to.to_tsecr = 0;
14333 	}
14334 
14335 	/*
14336 	 * If its the first time in we need to take care of options and
14337 	 * verify we can do SACK for rack!
14338 	 */
14339 	if (rack->r_state == 0) {
14340 		/* Should be init'd by rack_init() */
14341 		KASSERT(rack->rc_inp != NULL,
14342 		    ("%s: rack->rc_inp unexpectedly NULL", __func__));
14343 		if (rack->rc_inp == NULL) {
14344 			rack->rc_inp = tp->t_inpcb;
14345 		}
14346 
14347 		/*
14348 		 * Process options only when we get SYN/ACK back. The SYN
14349 		 * case for incoming connections is handled in tcp_syncache.
14350 		 * According to RFC1323 the window field in a SYN (i.e., a
14351 		 * <SYN> or <SYN,ACK>) segment itself is never scaled. XXX
14352 		 * this is traditional behavior, may need to be cleaned up.
14353 		 */
14354 		if (tp->t_state == TCPS_SYN_SENT && (thflags & TH_SYN)) {
14355 			/* Handle parallel SYN for ECN */
14356 			if (!(thflags & TH_ACK) &&
14357 			    ((thflags & (TH_CWR | TH_ECE)) == (TH_CWR | TH_ECE)) &&
14358 			    ((V_tcp_do_ecn == 1) || (V_tcp_do_ecn == 2))) {
14359 				tp->t_flags2 |= TF2_ECN_PERMIT;
14360 				tp->t_flags2 |= TF2_ECN_SND_ECE;
14361 				TCPSTAT_INC(tcps_ecn_shs);
14362 			}
14363 			if ((to.to_flags & TOF_SCALE) &&
14364 			    (tp->t_flags & TF_REQ_SCALE)) {
14365 				tp->t_flags |= TF_RCVD_SCALE;
14366 				tp->snd_scale = to.to_wscale;
14367 			} else
14368 				tp->t_flags &= ~TF_REQ_SCALE;
14369 			/*
14370 			 * Initial send window.  It will be updated with the
14371 			 * next incoming segment to the scaled value.
14372 			 */
14373 			tp->snd_wnd = th->th_win;
14374 			rack_validate_fo_sendwin_up(tp, rack);
14375 			if ((to.to_flags & TOF_TS) &&
14376 			    (tp->t_flags & TF_REQ_TSTMP)) {
14377 				tp->t_flags |= TF_RCVD_TSTMP;
14378 				tp->ts_recent = to.to_tsval;
14379 				tp->ts_recent_age = cts;
14380 			} else
14381 				tp->t_flags &= ~TF_REQ_TSTMP;
14382 			if (to.to_flags & TOF_MSS) {
14383 				tcp_mss(tp, to.to_mss);
14384 			}
14385 			if ((tp->t_flags & TF_SACK_PERMIT) &&
14386 			    (to.to_flags & TOF_SACKPERM) == 0)
14387 				tp->t_flags &= ~TF_SACK_PERMIT;
14388 			if (IS_FASTOPEN(tp->t_flags)) {
14389 				if (to.to_flags & TOF_FASTOPEN) {
14390 					uint16_t mss;
14391 
14392 					if (to.to_flags & TOF_MSS)
14393 						mss = to.to_mss;
14394 					else
14395 						if ((tp->t_inpcb->inp_vflag & INP_IPV6) != 0)
14396 							mss = TCP6_MSS;
14397 						else
14398 							mss = TCP_MSS;
14399 					tcp_fastopen_update_cache(tp, mss,
14400 					    to.to_tfo_len, to.to_tfo_cookie);
14401 				} else
14402 					tcp_fastopen_disable_path(tp);
14403 			}
14404 		}
14405 		/*
14406 		 * At this point we are at the initial call. Here we decide
14407 		 * if we are doing RACK or not. We do this by seeing if
14408 		 * TF_SACK_PERMIT is set and the sack-not-required is clear.
14409 		 * The code now does do dup-ack counting so if you don't
14410 		 * switch back you won't get rack & TLP, but you will still
14411 		 * get this stack.
14412 		 */
14413 
14414 		if ((rack_sack_not_required == 0) &&
14415 		    ((tp->t_flags & TF_SACK_PERMIT) == 0)) {
14416 			tcp_switch_back_to_default(tp);
14417 			(*tp->t_fb->tfb_tcp_do_segment) (m, th, so, tp, drop_hdrlen,
14418 			    tlen, iptos);
14419 #ifdef TCP_ACCOUNTING
14420 			sched_unpin();
14421 #endif
14422 			return (1);
14423 		}
14424 		tcp_set_hpts(tp->t_inpcb);
14425 		sack_filter_clear(&rack->r_ctl.rack_sf, th->th_ack);
14426 	}
14427 	if (thflags & TH_FIN)
14428 		tcp_log_end_status(tp, TCP_EI_STATUS_CLIENT_FIN);
14429 	us_cts = tcp_tv_to_usectick(&rack->r_ctl.act_rcv_time);
14430 	if ((rack->rc_gp_dyn_mul) &&
14431 	    (rack->use_fixed_rate == 0) &&
14432 	    (rack->rc_always_pace)) {
14433 		/* Check in on probertt */
14434 		rack_check_probe_rtt(rack, us_cts);
14435 	}
14436 	rack_clear_rate_sample(rack);
14437 	if (rack->forced_ack) {
14438 		uint32_t us_rtt;
14439 
14440 		/*
14441 		 * A persist or keep-alive was forced out, update our
14442 		 * min rtt time. Note we do not worry about lost
14443 		 * retransmissions since KEEP-ALIVES and persists
14444 		 * are usually way long on times of sending (though
14445 		 * if we were really paranoid or worried we could
14446 		 * at least use timestamps if available to validate).
14447 		 */
14448 		rack->forced_ack = 0;
14449 		if (tiwin == tp->snd_wnd) {
14450 			/*
14451 			 * Only apply the RTT update if this is
14452 			 * a response to our window probe. And that
14453 			 * means the rwnd sent must match the current
14454 			 * snd_wnd. If it does not, then we got a
14455 			 * window update ack instead.
14456 			 */
14457 			us_rtt = us_cts - rack->r_ctl.forced_ack_ts;
14458 			if (us_rtt == 0)
14459 				us_rtt = 1;
14460 			rack_apply_updated_usrtt(rack, us_rtt, us_cts);
14461 			tcp_rack_xmit_timer(rack, us_rtt, 0, us_rtt, 3, NULL, 1);
14462 		}
14463 	}
14464 	/*
14465 	 * This is the one exception case where we set the rack state
14466 	 * always. All other times (timers etc) we must have a rack-state
14467 	 * set (so we assure we have done the checks above for SACK).
14468 	 */
14469 	rack->r_ctl.rc_rcvtime = cts;
14470 	if (rack->r_state != tp->t_state)
14471 		rack_set_state(tp, rack);
14472 	if (SEQ_GT(th->th_ack, tp->snd_una) &&
14473 	    (rsm = RB_MIN(rack_rb_tree_head, &rack->r_ctl.rc_mtree)) != NULL)
14474 		kern_prefetch(rsm, &prev_state);
14475 	prev_state = rack->r_state;
14476 	retval = (*rack->r_substate) (m, th, so,
14477 	    tp, &to, drop_hdrlen,
14478 	    tlen, tiwin, thflags, nxt_pkt, iptos);
14479 #ifdef INVARIANTS
14480 	if ((retval == 0) &&
14481 	    (tp->t_inpcb == NULL)) {
14482 		panic("retval:%d tp:%p t_inpcb:NULL state:%d",
14483 		    retval, tp, prev_state);
14484 	}
14485 #endif
14486 	if (retval == 0) {
14487 		/*
14488 		 * If retval is 1 the tcb is unlocked and most likely the tp
14489 		 * is gone.
14490 		 */
14491 		INP_WLOCK_ASSERT(tp->t_inpcb);
14492 		if ((rack->rc_gp_dyn_mul) &&
14493 		    (rack->rc_always_pace) &&
14494 		    (rack->use_fixed_rate == 0) &&
14495 		    rack->in_probe_rtt &&
14496 		    (rack->r_ctl.rc_time_probertt_starts == 0)) {
14497 			/*
14498 			 * If we are going for target, lets recheck before
14499 			 * we output.
14500 			 */
14501 			rack_check_probe_rtt(rack, us_cts);
14502 		}
14503 		if (rack->set_pacing_done_a_iw == 0) {
14504 			/* How much has been acked? */
14505 			if ((tp->snd_una - tp->iss) > (ctf_fixed_maxseg(tp) * 10)) {
14506 				/* We have enough to set in the pacing segment size */
14507 				rack->set_pacing_done_a_iw = 1;
14508 				rack_set_pace_segments(tp, rack, __LINE__, NULL);
14509 			}
14510 		}
14511 		tcp_rack_xmit_timer_commit(rack, tp);
14512 #ifdef TCP_ACCOUNTING
14513 		/*
14514 		 * If we set the ack_val_se to what ack processing we are doing
14515 		 * we also want to track how many cycles we burned. Note
14516 		 * the bits after tcp_output we let be "free". This is because
14517 		 * we are also tracking the tcp_output times as well. Note the
14518 		 * use of 0xf here since we only have 11 counter (0 - 0xa) and
14519 		 * 0xf cannot be returned and is what we initialize it too to
14520 		 * indicate we are not doing the tabulations.
14521 		 */
14522 		if (ack_val_set != 0xf) {
14523 			uint64_t crtsc;
14524 
14525 			crtsc = get_cyclecount();
14526 			counter_u64_add(tcp_proc_time[ack_val_set] , (crtsc - ts_val));
14527 			if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
14528 				tp->tcp_proc_time[ack_val_set] += (crtsc - ts_val);
14529 			}
14530 		}
14531 #endif
14532 		if (nxt_pkt == 0) {
14533 			if ((rack->r_wanted_output != 0) || (rack->r_fast_output != 0)) {
14534 do_output_now:
14535 				did_out = 1;
14536 				(void)tp->t_fb->tfb_tcp_output(tp);
14537 			}
14538 			rack_start_hpts_timer(rack, tp, cts, 0, 0, 0);
14539 			rack_free_trim(rack);
14540 		}
14541 		/* Update any rounds needed */
14542 		if (SEQ_GEQ(tp->snd_una, rack->r_ctl.roundends)) {
14543 			rack->r_ctl.current_round++;
14544 			rack->r_ctl.roundends = tp->snd_max;
14545 			if (CC_ALGO(tp)->newround != NULL) {
14546 				CC_ALGO(tp)->newround(tp->ccv, rack->r_ctl.current_round);
14547 			}
14548 		}
14549 		if ((nxt_pkt == 0) &&
14550 		    ((rack->r_ctl.rc_hpts_flags & PACE_TMR_MASK) == 0) &&
14551 		    (SEQ_GT(tp->snd_max, tp->snd_una) ||
14552 		     (tp->t_flags & TF_DELACK) ||
14553 		     ((V_tcp_always_keepalive || rack->rc_inp->inp_socket->so_options & SO_KEEPALIVE) &&
14554 		      (tp->t_state <= TCPS_CLOSING)))) {
14555 			/* We could not send (probably in the hpts but stopped the timer earlier)? */
14556 			if ((tp->snd_max == tp->snd_una) &&
14557 			    ((tp->t_flags & TF_DELACK) == 0) &&
14558 			    (rack->rc_inp->inp_in_hpts) &&
14559 			    (rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT)) {
14560 				/* keep alive not needed if we are hptsi output yet */
14561 				;
14562 			} else {
14563 				int late = 0;
14564 				if (rack->rc_inp->inp_in_hpts) {
14565 					if (rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT) {
14566 						us_cts = tcp_get_usecs(NULL);
14567 						if (TSTMP_GT(rack->r_ctl.rc_last_output_to, us_cts)) {
14568 							rack->r_early = 1;
14569 							rack->r_ctl.rc_agg_early += (rack->r_ctl.rc_last_output_to - us_cts);
14570 						} else
14571 							late = 1;
14572 						rack->r_ctl.rc_hpts_flags &= ~PACE_PKT_OUTPUT;
14573 					}
14574 					tcp_hpts_remove(tp->t_inpcb, HPTS_REMOVE_OUTPUT);
14575 				}
14576 				if (late && (did_out == 0)) {
14577 					/*
14578 					 * We are late in the sending
14579 					 * and we did not call the output
14580 					 * (this probably should not happen).
14581 					 */
14582 					goto do_output_now;
14583 				}
14584 				rack_start_hpts_timer(rack, tp, tcp_get_usecs(NULL), 0, 0, 0);
14585 			}
14586 			way_out = 1;
14587 		} else if (nxt_pkt == 0) {
14588 			/* Do we have the correct timer running? */
14589 			rack_timer_audit(tp, rack, &so->so_snd);
14590 			way_out = 2;
14591 		}
14592 	done_with_input:
14593 		rack_log_doseg_done(rack, cts, nxt_pkt, did_out, way_out, max(1, nsegs));
14594 		if (did_out)
14595 			rack->r_wanted_output = 0;
14596 #ifdef INVARIANTS
14597 		if (tp->t_inpcb == NULL) {
14598 			panic("OP:%d retval:%d tp:%p t_inpcb:NULL state:%d",
14599 			      did_out,
14600 			      retval, tp, prev_state);
14601 		}
14602 #endif
14603 #ifdef TCP_ACCOUNTING
14604 	} else {
14605 		/*
14606 		 * Track the time (see above).
14607 		 */
14608 		if (ack_val_set != 0xf) {
14609 			uint64_t crtsc;
14610 
14611 			crtsc = get_cyclecount();
14612 			counter_u64_add(tcp_proc_time[ack_val_set] , (crtsc - ts_val));
14613 			/*
14614 			 * Note we *DO NOT* increment the per-tcb counters since
14615 			 * in the else the TP may be gone!!
14616 			 */
14617 		}
14618 #endif
14619 	}
14620 #ifdef TCP_ACCOUNTING
14621 	sched_unpin();
14622 #endif
14623 	return (retval);
14624 }
14625 
14626 void
14627 rack_do_segment(struct mbuf *m, struct tcphdr *th, struct socket *so,
14628     struct tcpcb *tp, int32_t drop_hdrlen, int32_t tlen, uint8_t iptos)
14629 {
14630 	struct timeval tv;
14631 
14632 	/* First lets see if we have old packets */
14633 	if (tp->t_in_pkt) {
14634 		if (ctf_do_queued_segments(so, tp, 1)) {
14635 			m_freem(m);
14636 			return;
14637 		}
14638 	}
14639 	if (m->m_flags & M_TSTMP_LRO) {
14640 		tv.tv_sec = m->m_pkthdr.rcv_tstmp /1000000000;
14641 		tv.tv_usec = (m->m_pkthdr.rcv_tstmp % 1000000000)/1000;
14642 	} else {
14643 		/* Should not be should we kassert instead? */
14644 		tcp_get_usecs(&tv);
14645 	}
14646 	if (rack_do_segment_nounlock(m, th, so, tp,
14647 				     drop_hdrlen, tlen, iptos, 0, &tv) == 0) {
14648 		INP_WUNLOCK(tp->t_inpcb);
14649 	}
14650 }
14651 
14652 struct rack_sendmap *
14653 tcp_rack_output(struct tcpcb *tp, struct tcp_rack *rack, uint32_t tsused)
14654 {
14655 	struct rack_sendmap *rsm = NULL;
14656 	int32_t idx;
14657 	uint32_t srtt = 0, thresh = 0, ts_low = 0;
14658 
14659 	/* Return the next guy to be re-transmitted */
14660 	if (RB_EMPTY(&rack->r_ctl.rc_mtree)) {
14661 		return (NULL);
14662 	}
14663 	if (tp->t_flags & TF_SENTFIN) {
14664 		/* retran the end FIN? */
14665 		return (NULL);
14666 	}
14667 	/* ok lets look at this one */
14668 	rsm = TAILQ_FIRST(&rack->r_ctl.rc_tmap);
14669 	if (rsm && ((rsm->r_flags & RACK_ACKED) == 0)) {
14670 		goto check_it;
14671 	}
14672 	rsm = rack_find_lowest_rsm(rack);
14673 	if (rsm == NULL) {
14674 		return (NULL);
14675 	}
14676 check_it:
14677 	if (((rack->rc_tp->t_flags & TF_SACK_PERMIT) == 0) &&
14678 	    (rsm->r_dupack >= DUP_ACK_THRESHOLD)) {
14679 		/*
14680 		 * No sack so we automatically do the 3 strikes and
14681 		 * retransmit (no rack timer would be started).
14682 		 */
14683 
14684 		return (rsm);
14685 	}
14686 	if (rsm->r_flags & RACK_ACKED) {
14687 		return (NULL);
14688 	}
14689 	if (((rsm->r_flags & RACK_SACK_PASSED) == 0) &&
14690 	    (rsm->r_dupack < DUP_ACK_THRESHOLD)) {
14691 		/* Its not yet ready */
14692 		return (NULL);
14693 	}
14694 	srtt = rack_grab_rtt(tp, rack);
14695 	idx = rsm->r_rtr_cnt - 1;
14696 	ts_low = (uint32_t)rsm->r_tim_lastsent[idx];
14697 	thresh = rack_calc_thresh_rack(rack, srtt, tsused);
14698 	if ((tsused == ts_low) ||
14699 	    (TSTMP_LT(tsused, ts_low))) {
14700 		/* No time since sending */
14701 		return (NULL);
14702 	}
14703 	if ((tsused - ts_low) < thresh) {
14704 		/* It has not been long enough yet */
14705 		return (NULL);
14706 	}
14707 	if ((rsm->r_dupack >= DUP_ACK_THRESHOLD) ||
14708 	    ((rsm->r_flags & RACK_SACK_PASSED) &&
14709 	     (rack->sack_attack_disable == 0))) {
14710 		/*
14711 		 * We have passed the dup-ack threshold <or>
14712 		 * a SACK has indicated this is missing.
14713 		 * Note that if you are a declared attacker
14714 		 * it is only the dup-ack threshold that
14715 		 * will cause retransmits.
14716 		 */
14717 		/* log retransmit reason */
14718 		rack_log_retran_reason(rack, rsm, (tsused - ts_low), thresh, 1);
14719 		rack->r_fast_output = 0;
14720 		return (rsm);
14721 	}
14722 	return (NULL);
14723 }
14724 
14725 static void
14726 rack_log_pacing_delay_calc(struct tcp_rack *rack, uint32_t len, uint32_t slot,
14727 			   uint64_t bw_est, uint64_t bw, uint64_t len_time, int method,
14728 			   int line, struct rack_sendmap *rsm, uint8_t quality)
14729 {
14730 	if (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
14731 		union tcp_log_stackspecific log;
14732 		struct timeval tv;
14733 
14734 		memset(&log, 0, sizeof(log));
14735 		log.u_bbr.flex1 = slot;
14736 		log.u_bbr.flex2 = len;
14737 		log.u_bbr.flex3 = rack->r_ctl.rc_pace_min_segs;
14738 		log.u_bbr.flex4 = rack->r_ctl.rc_pace_max_segs;
14739 		log.u_bbr.flex5 = rack->r_ctl.rack_per_of_gp_ss;
14740 		log.u_bbr.flex6 = rack->r_ctl.rack_per_of_gp_ca;
14741 		log.u_bbr.use_lt_bw = rack->rc_ack_can_sendout_data;
14742 		log.u_bbr.use_lt_bw <<= 1;
14743 		log.u_bbr.use_lt_bw |= rack->r_late;
14744 		log.u_bbr.use_lt_bw <<= 1;
14745 		log.u_bbr.use_lt_bw |= rack->r_early;
14746 		log.u_bbr.use_lt_bw <<= 1;
14747 		log.u_bbr.use_lt_bw |= rack->app_limited_needs_set;
14748 		log.u_bbr.use_lt_bw <<= 1;
14749 		log.u_bbr.use_lt_bw |= rack->rc_gp_filled;
14750 		log.u_bbr.use_lt_bw <<= 1;
14751 		log.u_bbr.use_lt_bw |= rack->measure_saw_probe_rtt;
14752 		log.u_bbr.use_lt_bw <<= 1;
14753 		log.u_bbr.use_lt_bw |= rack->in_probe_rtt;
14754 		log.u_bbr.use_lt_bw <<= 1;
14755 		log.u_bbr.use_lt_bw |= rack->gp_ready;
14756 		log.u_bbr.pkt_epoch = line;
14757 		log.u_bbr.epoch = rack->r_ctl.rc_agg_delayed;
14758 		log.u_bbr.lt_epoch = rack->r_ctl.rc_agg_early;
14759 		log.u_bbr.applimited = rack->r_ctl.rack_per_of_gp_rec;
14760 		log.u_bbr.bw_inuse = bw_est;
14761 		log.u_bbr.delRate = bw;
14762 		if (rack->r_ctl.gp_bw == 0)
14763 			log.u_bbr.cur_del_rate = 0;
14764 		else
14765 			log.u_bbr.cur_del_rate = rack_get_bw(rack);
14766 		log.u_bbr.rttProp = len_time;
14767 		log.u_bbr.pkts_out = rack->r_ctl.rc_rack_min_rtt;
14768 		log.u_bbr.lost = rack->r_ctl.rc_probertt_sndmax_atexit;
14769 		log.u_bbr.pacing_gain = rack_get_output_gain(rack, rsm);
14770 		if (rack->r_ctl.cwnd_to_use < rack->rc_tp->snd_ssthresh) {
14771 			/* We are in slow start */
14772 			log.u_bbr.flex7 = 1;
14773 		} else {
14774 			/* we are on congestion avoidance */
14775 			log.u_bbr.flex7 = 0;
14776 		}
14777 		log.u_bbr.flex8 = method;
14778 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
14779 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
14780 		log.u_bbr.cwnd_gain = rack->rc_gp_saw_rec;
14781 		log.u_bbr.cwnd_gain <<= 1;
14782 		log.u_bbr.cwnd_gain |= rack->rc_gp_saw_ss;
14783 		log.u_bbr.cwnd_gain <<= 1;
14784 		log.u_bbr.cwnd_gain |= rack->rc_gp_saw_ca;
14785 		log.u_bbr.bbr_substate = quality;
14786 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
14787 		    &rack->rc_inp->inp_socket->so_rcv,
14788 		    &rack->rc_inp->inp_socket->so_snd,
14789 		    BBR_LOG_HPTSI_CALC, 0,
14790 		    0, &log, false, &tv);
14791 	}
14792 }
14793 
14794 static uint32_t
14795 rack_get_pacing_len(struct tcp_rack *rack, uint64_t bw, uint32_t mss)
14796 {
14797 	uint32_t new_tso, user_max;
14798 
14799 	user_max = rack->rc_user_set_max_segs * mss;
14800 	if (rack->rc_force_max_seg) {
14801 		return (user_max);
14802 	}
14803 	if (rack->use_fixed_rate &&
14804 	    ((rack->r_ctl.crte == NULL) ||
14805 	     (bw != rack->r_ctl.crte->rate))) {
14806 		/* Use the user mss since we are not exactly matched */
14807 		return (user_max);
14808 	}
14809 	new_tso = tcp_get_pacing_burst_size(rack->rc_tp, bw, mss, rack_pace_one_seg, rack->r_ctl.crte, NULL);
14810 	if (new_tso > user_max)
14811 		new_tso = user_max;
14812 	return (new_tso);
14813 }
14814 
14815 static int32_t
14816 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)
14817 {
14818 	uint64_t lentim, fill_bw;
14819 
14820 	/* Lets first see if we are full, if so continue with normal rate */
14821 	rack->r_via_fill_cw = 0;
14822 	if (ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked) > rack->r_ctl.cwnd_to_use)
14823 		return (slot);
14824 	if ((ctf_outstanding(rack->rc_tp) + (segsiz-1)) > rack->rc_tp->snd_wnd)
14825 		return (slot);
14826 	if (rack->r_ctl.rc_last_us_rtt == 0)
14827 		return (slot);
14828 	if (rack->rc_pace_fill_if_rttin_range &&
14829 	    (rack->r_ctl.rc_last_us_rtt >=
14830 	     (get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt) * rack->rtt_limit_mul))) {
14831 		/* The rtt is huge, N * smallest, lets not fill */
14832 		return (slot);
14833 	}
14834 	/*
14835 	 * first lets calculate the b/w based on the last us-rtt
14836 	 * and the sndwnd.
14837 	 */
14838 	fill_bw = rack->r_ctl.cwnd_to_use;
14839 	/* Take the rwnd if its smaller */
14840 	if (fill_bw > rack->rc_tp->snd_wnd)
14841 		fill_bw = rack->rc_tp->snd_wnd;
14842 	if (rack->r_fill_less_agg) {
14843 		/*
14844 		 * Now take away the inflight (this will reduce our
14845 		 * aggressiveness and yeah, if we get that much out in 1RTT
14846 		 * we will have had acks come back and still be behind).
14847 		 */
14848 		fill_bw -= ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
14849 	}
14850 	/* Now lets make it into a b/w */
14851 	fill_bw *= (uint64_t)HPTS_USEC_IN_SEC;
14852 	fill_bw /= (uint64_t)rack->r_ctl.rc_last_us_rtt;
14853 	/* We are below the min b/w */
14854 	if (non_paced)
14855 		*rate_wanted = fill_bw;
14856 	if ((fill_bw < RACK_MIN_BW) || (fill_bw < *rate_wanted))
14857 		return (slot);
14858 	if (rack->r_ctl.bw_rate_cap && (fill_bw > rack->r_ctl.bw_rate_cap))
14859 		fill_bw = rack->r_ctl.bw_rate_cap;
14860 	rack->r_via_fill_cw = 1;
14861 	if (rack->r_rack_hw_rate_caps &&
14862 	    (rack->r_ctl.crte != NULL)) {
14863 		uint64_t high_rate;
14864 
14865 		high_rate = tcp_hw_highest_rate(rack->r_ctl.crte);
14866 		if (fill_bw > high_rate) {
14867 			/* We are capping bw at the highest rate table entry */
14868 			if (*rate_wanted > high_rate) {
14869 				/* The original rate was also capped */
14870 				rack->r_via_fill_cw = 0;
14871 			}
14872 			rack_log_hdwr_pacing(rack,
14873 					     fill_bw, high_rate, __LINE__,
14874 					     0, 3);
14875 			fill_bw = high_rate;
14876 			if (capped)
14877 				*capped = 1;
14878 		}
14879 	} else if ((rack->r_ctl.crte == NULL) &&
14880 		   (rack->rack_hdrw_pacing == 0) &&
14881 		   (rack->rack_hdw_pace_ena) &&
14882 		   rack->r_rack_hw_rate_caps &&
14883 		   (rack->rack_attempt_hdwr_pace == 0) &&
14884 		   (rack->rc_inp->inp_route.ro_nh != NULL) &&
14885 		   (rack->rc_inp->inp_route.ro_nh->nh_ifp != NULL)) {
14886 		/*
14887 		 * Ok we may have a first attempt that is greater than our top rate
14888 		 * lets check.
14889 		 */
14890 		uint64_t high_rate;
14891 
14892 		high_rate = tcp_hw_highest_rate_ifp(rack->rc_inp->inp_route.ro_nh->nh_ifp, rack->rc_inp);
14893 		if (high_rate) {
14894 			if (fill_bw > high_rate) {
14895 				fill_bw = high_rate;
14896 				if (capped)
14897 					*capped = 1;
14898 			}
14899 		}
14900 	}
14901 	/*
14902 	 * Ok fill_bw holds our mythical b/w to fill the cwnd
14903 	 * in a rtt, what does that time wise equate too?
14904 	 */
14905 	lentim = (uint64_t)(len) * (uint64_t)HPTS_USEC_IN_SEC;
14906 	lentim /= fill_bw;
14907 	*rate_wanted = fill_bw;
14908 	if (non_paced || (lentim < slot)) {
14909 		rack_log_pacing_delay_calc(rack, len, slot, fill_bw,
14910 					   0, lentim, 12, __LINE__, NULL, 0);
14911 		return ((int32_t)lentim);
14912 	} else
14913 		return (slot);
14914 }
14915 
14916 static int32_t
14917 rack_get_pacing_delay(struct tcp_rack *rack, struct tcpcb *tp, uint32_t len, struct rack_sendmap *rsm, uint32_t segsiz)
14918 {
14919 	uint64_t srtt;
14920 	int32_t slot = 0;
14921 	int can_start_hw_pacing = 1;
14922 	int err;
14923 
14924 	if (rack->rc_always_pace == 0) {
14925 		/*
14926 		 * We use the most optimistic possible cwnd/srtt for
14927 		 * sending calculations. This will make our
14928 		 * calculation anticipate getting more through
14929 		 * quicker then possible. But thats ok we don't want
14930 		 * the peer to have a gap in data sending.
14931 		 */
14932 		uint64_t cwnd, tr_perms = 0;
14933 		int32_t reduce = 0;
14934 
14935 	old_method:
14936 		/*
14937 		 * We keep no precise pacing with the old method
14938 		 * instead we use the pacer to mitigate bursts.
14939 		 */
14940 		if (rack->r_ctl.rc_rack_min_rtt)
14941 			srtt = rack->r_ctl.rc_rack_min_rtt;
14942 		else
14943 			srtt = max(tp->t_srtt, 1);
14944 		if (rack->r_ctl.rc_rack_largest_cwnd)
14945 			cwnd = rack->r_ctl.rc_rack_largest_cwnd;
14946 		else
14947 			cwnd = rack->r_ctl.cwnd_to_use;
14948 		/* Inflate cwnd by 1000 so srtt of usecs is in ms */
14949 		tr_perms = (cwnd * 1000) / srtt;
14950 		if (tr_perms == 0) {
14951 			tr_perms = ctf_fixed_maxseg(tp);
14952 		}
14953 		/*
14954 		 * Calculate how long this will take to drain, if
14955 		 * the calculation comes out to zero, thats ok we
14956 		 * will use send_a_lot to possibly spin around for
14957 		 * more increasing tot_len_this_send to the point
14958 		 * that its going to require a pace, or we hit the
14959 		 * cwnd. Which in that case we are just waiting for
14960 		 * a ACK.
14961 		 */
14962 		slot = len / tr_perms;
14963 		/* Now do we reduce the time so we don't run dry? */
14964 		if (slot && rack_slot_reduction) {
14965 			reduce = (slot / rack_slot_reduction);
14966 			if (reduce < slot) {
14967 				slot -= reduce;
14968 			} else
14969 				slot = 0;
14970 		}
14971 		slot *= HPTS_USEC_IN_MSEC;
14972 		if (rack->rc_pace_to_cwnd) {
14973 			uint64_t rate_wanted = 0;
14974 
14975 			slot = pace_to_fill_cwnd(rack, slot, len, segsiz, NULL, &rate_wanted, 1);
14976 			rack->rc_ack_can_sendout_data = 1;
14977 			rack_log_pacing_delay_calc(rack, len, slot, rate_wanted, 0, 0, 14, __LINE__, NULL, 0);
14978 		} else
14979 			rack_log_pacing_delay_calc(rack, len, slot, tr_perms, reduce, 0, 7, __LINE__, NULL, 0);
14980 	} else {
14981 		uint64_t bw_est, res, lentim, rate_wanted;
14982 		uint32_t orig_val, segs, oh;
14983 		int capped = 0;
14984 		int prev_fill;
14985 
14986 		if ((rack->r_rr_config == 1) && rsm) {
14987 			return (rack->r_ctl.rc_min_to);
14988 		}
14989 		if (rack->use_fixed_rate) {
14990 			rate_wanted = bw_est = rack_get_fixed_pacing_bw(rack);
14991 		} else if ((rack->r_ctl.init_rate == 0) &&
14992 #ifdef NETFLIX_PEAKRATE
14993 			   (rack->rc_tp->t_maxpeakrate == 0) &&
14994 #endif
14995 			   (rack->r_ctl.gp_bw == 0)) {
14996 			/* no way to yet do an estimate */
14997 			bw_est = rate_wanted = 0;
14998 		} else {
14999 			bw_est = rack_get_bw(rack);
15000 			rate_wanted = rack_get_output_bw(rack, bw_est, rsm, &capped);
15001 		}
15002 		if ((bw_est == 0) || (rate_wanted == 0) ||
15003 		    ((rack->gp_ready == 0) && (rack->use_fixed_rate == 0))) {
15004 			/*
15005 			 * No way yet to make a b/w estimate or
15006 			 * our raise is set incorrectly.
15007 			 */
15008 			goto old_method;
15009 		}
15010 		/* We need to account for all the overheads */
15011 		segs = (len + segsiz - 1) / segsiz;
15012 		/*
15013 		 * We need the diff between 1514 bytes (e-mtu with e-hdr)
15014 		 * and how much data we put in each packet. Yes this
15015 		 * means we may be off if we are larger than 1500 bytes
15016 		 * or smaller. But this just makes us more conservative.
15017 		 */
15018 		if (rack_hw_rate_min &&
15019 		    (bw_est < rack_hw_rate_min))
15020 			can_start_hw_pacing = 0;
15021 		if (ETHERNET_SEGMENT_SIZE > segsiz)
15022 			oh = ETHERNET_SEGMENT_SIZE - segsiz;
15023 		else
15024 			oh = 0;
15025 		segs *= oh;
15026 		lentim = (uint64_t)(len + segs) * (uint64_t)HPTS_USEC_IN_SEC;
15027 		res = lentim / rate_wanted;
15028 		slot = (uint32_t)res;
15029 		orig_val = rack->r_ctl.rc_pace_max_segs;
15030 		if (rack->r_ctl.crte == NULL) {
15031 			/*
15032 			 * Only do this if we are not hardware pacing
15033 			 * since if we are doing hw-pacing below we will
15034 			 * set make a call after setting up or changing
15035 			 * the rate.
15036 			 */
15037 			rack_set_pace_segments(rack->rc_tp, rack, __LINE__, NULL);
15038 		} else if (rack->rc_inp->inp_snd_tag == NULL) {
15039 			/*
15040 			 * We lost our rate somehow, this can happen
15041 			 * if the interface changed underneath us.
15042 			 */
15043 			tcp_rel_pacing_rate(rack->r_ctl.crte, rack->rc_tp);
15044 			rack->r_ctl.crte = NULL;
15045 			/* Lets re-allow attempting to setup pacing */
15046 			rack->rack_hdrw_pacing = 0;
15047 			rack->rack_attempt_hdwr_pace = 0;
15048 			rack_log_hdwr_pacing(rack,
15049 					     rate_wanted, bw_est, __LINE__,
15050 					     0, 6);
15051 		}
15052 		/* Did we change the TSO size, if so log it */
15053 		if (rack->r_ctl.rc_pace_max_segs != orig_val)
15054 			rack_log_pacing_delay_calc(rack, len, slot, orig_val, 0, 0, 15, __LINE__, NULL, 0);
15055 		prev_fill = rack->r_via_fill_cw;
15056 		if ((rack->rc_pace_to_cwnd) &&
15057 		    (capped == 0) &&
15058 		    (rack->use_fixed_rate == 0) &&
15059 		    (rack->in_probe_rtt == 0) &&
15060 		    (IN_FASTRECOVERY(rack->rc_tp->t_flags) == 0)) {
15061 			/*
15062 			 * We want to pace at our rate *or* faster to
15063 			 * fill the cwnd to the max if its not full.
15064 			 */
15065 			slot = pace_to_fill_cwnd(rack, slot, (len+segs), segsiz, &capped, &rate_wanted, 0);
15066 		}
15067 		if ((rack->rc_inp->inp_route.ro_nh != NULL) &&
15068 		    (rack->rc_inp->inp_route.ro_nh->nh_ifp != NULL)) {
15069 			if ((rack->rack_hdw_pace_ena) &&
15070 			    (can_start_hw_pacing > 0) &&
15071 			    (rack->rack_hdrw_pacing == 0) &&
15072 			    (rack->rack_attempt_hdwr_pace == 0)) {
15073 				/*
15074 				 * Lets attempt to turn on hardware pacing
15075 				 * if we can.
15076 				 */
15077 				rack->rack_attempt_hdwr_pace = 1;
15078 				rack->r_ctl.crte = tcp_set_pacing_rate(rack->rc_tp,
15079 								       rack->rc_inp->inp_route.ro_nh->nh_ifp,
15080 								       rate_wanted,
15081 								       RS_PACING_GEQ,
15082 								       &err, &rack->r_ctl.crte_prev_rate);
15083 				if (rack->r_ctl.crte) {
15084 					rack->rack_hdrw_pacing = 1;
15085 					rack->r_ctl.rc_pace_max_segs = tcp_get_pacing_burst_size(tp, rate_wanted, segsiz,
15086 												 0, rack->r_ctl.crte,
15087 												 NULL);
15088 					rack_log_hdwr_pacing(rack,
15089 							     rate_wanted, rack->r_ctl.crte->rate, __LINE__,
15090 							     err, 0);
15091 					rack->r_ctl.last_hw_bw_req = rate_wanted;
15092 				} else {
15093 					counter_u64_add(rack_hw_pace_init_fail, 1);
15094 				}
15095 			} else if (rack->rack_hdrw_pacing &&
15096 				   (rack->r_ctl.last_hw_bw_req != rate_wanted)) {
15097 				/* Do we need to adjust our rate? */
15098 				const struct tcp_hwrate_limit_table *nrte;
15099 
15100 				if (rack->r_up_only &&
15101 				    (rate_wanted < rack->r_ctl.crte->rate)) {
15102 					/**
15103 					 * We have four possible states here
15104 					 * having to do with the previous time
15105 					 * and this time.
15106 					 *   previous  |  this-time
15107 					 * A)     0      |     0   -- fill_cw not in the picture
15108 					 * B)     1      |     0   -- we were doing a fill-cw but now are not
15109 					 * C)     1      |     1   -- all rates from fill_cw
15110 					 * D)     0      |     1   -- we were doing non-fill and now we are filling
15111 					 *
15112 					 * For case A, C and D we don't allow a drop. But for
15113 					 * case B where we now our on our steady rate we do
15114 					 * allow a drop.
15115 					 *
15116 					 */
15117 					if (!((prev_fill == 1) && (rack->r_via_fill_cw == 0)))
15118 						goto done_w_hdwr;
15119 				}
15120 				if ((rate_wanted > rack->r_ctl.crte->rate) ||
15121 				    (rate_wanted <= rack->r_ctl.crte_prev_rate)) {
15122 					if (rack_hw_rate_to_low &&
15123 					    (bw_est < rack_hw_rate_to_low)) {
15124 						/*
15125 						 * The pacing rate is too low for hardware, but
15126 						 * do allow hardware pacing to be restarted.
15127 						 */
15128 						rack_log_hdwr_pacing(rack,
15129 							     bw_est, rack->r_ctl.crte->rate, __LINE__,
15130 							     0, 5);
15131 						tcp_rel_pacing_rate(rack->r_ctl.crte, rack->rc_tp);
15132 						rack->r_ctl.crte = NULL;
15133 						rack->rack_attempt_hdwr_pace = 0;
15134 						rack->rack_hdrw_pacing = 0;
15135 						rack_set_pace_segments(rack->rc_tp, rack, __LINE__, &rate_wanted);
15136 						goto done_w_hdwr;
15137 					}
15138 					nrte = tcp_chg_pacing_rate(rack->r_ctl.crte,
15139 								   rack->rc_tp,
15140 								   rack->rc_inp->inp_route.ro_nh->nh_ifp,
15141 								   rate_wanted,
15142 								   RS_PACING_GEQ,
15143 								   &err, &rack->r_ctl.crte_prev_rate);
15144 					if (nrte == NULL) {
15145 						/* Lost the rate */
15146 						rack->rack_hdrw_pacing = 0;
15147 						rack->r_ctl.crte = NULL;
15148 						rack_log_hdwr_pacing(rack,
15149 								     rate_wanted, 0, __LINE__,
15150 								     err, 1);
15151 						rack_set_pace_segments(rack->rc_tp, rack, __LINE__, &rate_wanted);
15152 						counter_u64_add(rack_hw_pace_lost, 1);
15153 					} else if (nrte != rack->r_ctl.crte) {
15154 						rack->r_ctl.crte = nrte;
15155 						rack->r_ctl.rc_pace_max_segs = tcp_get_pacing_burst_size(tp, rate_wanted,
15156 													 segsiz, 0,
15157 													 rack->r_ctl.crte,
15158 													 NULL);
15159 						rack_log_hdwr_pacing(rack,
15160 								     rate_wanted, rack->r_ctl.crte->rate, __LINE__,
15161 								     err, 2);
15162 						rack->r_ctl.last_hw_bw_req = rate_wanted;
15163 					}
15164 				} else {
15165 					/* We just need to adjust the segment size */
15166 					rack_set_pace_segments(rack->rc_tp, rack, __LINE__, &rate_wanted);
15167 					rack_log_hdwr_pacing(rack,
15168 							     rate_wanted, rack->r_ctl.crte->rate, __LINE__,
15169 							     0, 4);
15170 					rack->r_ctl.last_hw_bw_req = rate_wanted;
15171 				}
15172 			}
15173 		}
15174 		if ((rack->r_ctl.crte != NULL) &&
15175 		    (rack->r_ctl.crte->rate == rate_wanted)) {
15176 			/*
15177 			 * We need to add a extra if the rates
15178 			 * are exactly matched. The idea is
15179 			 * we want the software to make sure the
15180 			 * queue is empty before adding more, this
15181 			 * gives us N MSS extra pace times where
15182 			 * N is our sysctl
15183 			 */
15184 			slot += (rack->r_ctl.crte->time_between * rack_hw_pace_extra_slots);
15185 		}
15186 done_w_hdwr:
15187 		if (rack_limit_time_with_srtt &&
15188 		    (rack->use_fixed_rate == 0) &&
15189 #ifdef NETFLIX_PEAKRATE
15190 		    (rack->rc_tp->t_maxpeakrate == 0) &&
15191 #endif
15192 		    (rack->rack_hdrw_pacing == 0)) {
15193 			/*
15194 			 * Sanity check, we do not allow the pacing delay
15195 			 * to be longer than the SRTT of the path. If it is
15196 			 * a slow path, then adding a packet should increase
15197 			 * the RTT and compensate for this i.e. the srtt will
15198 			 * be greater so the allowed pacing time will be greater.
15199 			 *
15200 			 * Note this restriction is not for where a peak rate
15201 			 * is set, we are doing fixed pacing or hardware pacing.
15202 			 */
15203 			if (rack->rc_tp->t_srtt)
15204 				srtt = rack->rc_tp->t_srtt;
15205 			else
15206 				srtt = RACK_INITIAL_RTO * HPTS_USEC_IN_MSEC;	/* its in ms convert */
15207 			if (srtt < (uint64_t)slot) {
15208 				rack_log_pacing_delay_calc(rack, srtt, slot, rate_wanted, bw_est, lentim, 99, __LINE__, NULL, 0);
15209 				slot = srtt;
15210 			}
15211 		}
15212 		rack_log_pacing_delay_calc(rack, len, slot, rate_wanted, bw_est, lentim, 2, __LINE__, rsm, 0);
15213 	}
15214 	if (rack->r_ctl.crte && (rack->r_ctl.crte->rs_num_enobufs > 0)) {
15215 		/*
15216 		 * If this rate is seeing enobufs when it
15217 		 * goes to send then either the nic is out
15218 		 * of gas or we are mis-estimating the time
15219 		 * somehow and not letting the queue empty
15220 		 * completely. Lets add to the pacing time.
15221 		 */
15222 		int hw_boost_delay;
15223 
15224 		hw_boost_delay = rack->r_ctl.crte->time_between * rack_enobuf_hw_boost_mult;
15225 		if (hw_boost_delay > rack_enobuf_hw_max)
15226 			hw_boost_delay = rack_enobuf_hw_max;
15227 		else if (hw_boost_delay < rack_enobuf_hw_min)
15228 			hw_boost_delay = rack_enobuf_hw_min;
15229 		slot += hw_boost_delay;
15230 	}
15231 	if (slot)
15232 		counter_u64_add(rack_calc_nonzero, 1);
15233 	else
15234 		counter_u64_add(rack_calc_zero, 1);
15235 	return (slot);
15236 }
15237 
15238 static void
15239 rack_start_gp_measurement(struct tcpcb *tp, struct tcp_rack *rack,
15240     tcp_seq startseq, uint32_t sb_offset)
15241 {
15242 	struct rack_sendmap *my_rsm = NULL;
15243 	struct rack_sendmap fe;
15244 
15245 	if (tp->t_state < TCPS_ESTABLISHED) {
15246 		/*
15247 		 * We don't start any measurements if we are
15248 		 * not at least established.
15249 		 */
15250 		return;
15251 	}
15252 	if (tp->t_state >= TCPS_FIN_WAIT_1) {
15253 		/*
15254 		 * We will get no more data into the SB
15255 		 * this means we need to have the data available
15256 		 * before we start a measurement.
15257 		 */
15258 
15259 		if (sbavail(&tp->t_inpcb->inp_socket->so_snd) <
15260 		    max(rc_init_window(rack),
15261 			(MIN_GP_WIN * ctf_fixed_maxseg(tp)))) {
15262 			/* Nope not enough data */
15263 			return;
15264 		}
15265 	}
15266 	tp->t_flags |= TF_GPUTINPROG;
15267 	rack->r_ctl.rc_gp_lowrtt = 0xffffffff;
15268 	rack->r_ctl.rc_gp_high_rwnd = rack->rc_tp->snd_wnd;
15269 	tp->gput_seq = startseq;
15270 	rack->app_limited_needs_set = 0;
15271 	if (rack->in_probe_rtt)
15272 		rack->measure_saw_probe_rtt = 1;
15273 	else if ((rack->measure_saw_probe_rtt) &&
15274 		 (SEQ_GEQ(tp->gput_seq, rack->r_ctl.rc_probertt_sndmax_atexit)))
15275 		rack->measure_saw_probe_rtt = 0;
15276 	if (rack->rc_gp_filled)
15277 		tp->gput_ts = tcp_tv_to_usectick(&rack->r_ctl.act_rcv_time);
15278 	else {
15279 		/* Special case initial measurement */
15280 		struct timeval tv;
15281 
15282 		tp->gput_ts = tcp_get_usecs(&tv);
15283 		rack->r_ctl.rc_gp_output_ts = rack_to_usec_ts(&tv);
15284 	}
15285 	/*
15286 	 * We take a guess out into the future,
15287 	 * if we have no measurement and no
15288 	 * initial rate, we measure the first
15289 	 * initial-windows worth of data to
15290 	 * speed up getting some GP measurement and
15291 	 * thus start pacing.
15292 	 */
15293 	if ((rack->rc_gp_filled == 0) && (rack->r_ctl.init_rate == 0)) {
15294 		rack->app_limited_needs_set = 1;
15295 		tp->gput_ack = startseq + max(rc_init_window(rack),
15296 					      (MIN_GP_WIN * ctf_fixed_maxseg(tp)));
15297 		rack_log_pacing_delay_calc(rack,
15298 					   tp->gput_seq,
15299 					   tp->gput_ack,
15300 					   0,
15301 					   tp->gput_ts,
15302 					   rack->r_ctl.rc_app_limited_cnt,
15303 					   9,
15304 					   __LINE__, NULL, 0);
15305 		return;
15306 	}
15307 	if (sb_offset) {
15308 		/*
15309 		 * We are out somewhere in the sb
15310 		 * can we use the already outstanding data?
15311 		 */
15312 		if (rack->r_ctl.rc_app_limited_cnt == 0) {
15313 			/*
15314 			 * Yes first one is good and in this case
15315 			 * the tp->gput_ts is correctly set based on
15316 			 * the last ack that arrived (no need to
15317 			 * set things up when an ack comes in).
15318 			 */
15319 			my_rsm = RB_MIN(rack_rb_tree_head, &rack->r_ctl.rc_mtree);
15320 			if ((my_rsm == NULL) ||
15321 			    (my_rsm->r_rtr_cnt != 1)) {
15322 				/* retransmission? */
15323 				goto use_latest;
15324 			}
15325 		} else {
15326 			if (rack->r_ctl.rc_first_appl == NULL) {
15327 				/*
15328 				 * If rc_first_appl is NULL
15329 				 * then the cnt should be 0.
15330 				 * This is probably an error, maybe
15331 				 * a KASSERT would be approprate.
15332 				 */
15333 				goto use_latest;
15334 			}
15335 			/*
15336 			 * If we have a marker pointer to the last one that is
15337 			 * app limited we can use that, but we need to set
15338 			 * things up so that when it gets ack'ed we record
15339 			 * the ack time (if its not already acked).
15340 			 */
15341 			rack->app_limited_needs_set = 1;
15342 			/*
15343 			 * We want to get to the rsm that is either
15344 			 * next with space i.e. over 1 MSS or the one
15345 			 * after that (after the app-limited).
15346 			 */
15347 			my_rsm = RB_NEXT(rack_rb_tree_head, &rack->r_ctl.rc_mtree,
15348 					 rack->r_ctl.rc_first_appl);
15349 			if (my_rsm) {
15350 				if ((my_rsm->r_end - my_rsm->r_start) <= ctf_fixed_maxseg(tp))
15351 					/* Have to use the next one */
15352 					my_rsm = RB_NEXT(rack_rb_tree_head, &rack->r_ctl.rc_mtree,
15353 							 my_rsm);
15354 				else {
15355 					/* Use after the first MSS of it is acked */
15356 					tp->gput_seq = my_rsm->r_start + ctf_fixed_maxseg(tp);
15357 					goto start_set;
15358 				}
15359 			}
15360 			if ((my_rsm == NULL) ||
15361 			    (my_rsm->r_rtr_cnt != 1)) {
15362 				/*
15363 				 * Either its a retransmit or
15364 				 * the last is the app-limited one.
15365 				 */
15366 				goto use_latest;
15367 			}
15368 		}
15369 		tp->gput_seq = my_rsm->r_start;
15370 start_set:
15371 		if (my_rsm->r_flags & RACK_ACKED) {
15372 			/*
15373 			 * This one has been acked use the arrival ack time
15374 			 */
15375 			tp->gput_ts = (uint32_t)my_rsm->r_ack_arrival;
15376 			rack->app_limited_needs_set = 0;
15377 		}
15378 		rack->r_ctl.rc_gp_output_ts = my_rsm->r_tim_lastsent[(my_rsm->r_rtr_cnt-1)];
15379 		tp->gput_ack = tp->gput_seq + rack_get_measure_window(tp, rack);
15380 		rack_log_pacing_delay_calc(rack,
15381 					   tp->gput_seq,
15382 					   tp->gput_ack,
15383 					   (uint64_t)my_rsm,
15384 					   tp->gput_ts,
15385 					   rack->r_ctl.rc_app_limited_cnt,
15386 					   9,
15387 					   __LINE__, NULL, 0);
15388 		return;
15389 	}
15390 
15391 use_latest:
15392 	/*
15393 	 * We don't know how long we may have been
15394 	 * idle or if this is the first-send. Lets
15395 	 * setup the flag so we will trim off
15396 	 * the first ack'd data so we get a true
15397 	 * measurement.
15398 	 */
15399 	rack->app_limited_needs_set = 1;
15400 	tp->gput_ack = startseq + rack_get_measure_window(tp, rack);
15401 	/* Find this guy so we can pull the send time */
15402 	fe.r_start = startseq;
15403 	my_rsm = RB_FIND(rack_rb_tree_head, &rack->r_ctl.rc_mtree, &fe);
15404 	if (my_rsm) {
15405 		rack->r_ctl.rc_gp_output_ts = my_rsm->r_tim_lastsent[(my_rsm->r_rtr_cnt-1)];
15406 		if (my_rsm->r_flags & RACK_ACKED) {
15407 			/*
15408 			 * Unlikely since its probably what was
15409 			 * just transmitted (but I am paranoid).
15410 			 */
15411 			tp->gput_ts = (uint32_t)my_rsm->r_ack_arrival;
15412 			rack->app_limited_needs_set = 0;
15413 		}
15414 		if (SEQ_LT(my_rsm->r_start, tp->gput_seq)) {
15415 			/* This also is unlikely */
15416 			tp->gput_seq = my_rsm->r_start;
15417 		}
15418 	} else {
15419 		/*
15420 		 * TSNH unless we have some send-map limit,
15421 		 * and even at that it should not be hitting
15422 		 * that limit (we should have stopped sending).
15423 		 */
15424 		struct timeval tv;
15425 
15426 		microuptime(&tv);
15427 		rack->r_ctl.rc_gp_output_ts = rack_to_usec_ts(&tv);
15428 	}
15429 	rack_log_pacing_delay_calc(rack,
15430 				   tp->gput_seq,
15431 				   tp->gput_ack,
15432 				   (uint64_t)my_rsm,
15433 				   tp->gput_ts,
15434 				   rack->r_ctl.rc_app_limited_cnt,
15435 				   9, __LINE__, NULL, 0);
15436 }
15437 
15438 static inline uint32_t
15439 rack_what_can_we_send(struct tcpcb *tp, struct tcp_rack *rack,  uint32_t cwnd_to_use,
15440     uint32_t avail, int32_t sb_offset)
15441 {
15442 	uint32_t len;
15443 	uint32_t sendwin;
15444 
15445 	if (tp->snd_wnd > cwnd_to_use)
15446 		sendwin = cwnd_to_use;
15447 	else
15448 		sendwin = tp->snd_wnd;
15449 	if (ctf_outstanding(tp) >= tp->snd_wnd) {
15450 		/* We never want to go over our peers rcv-window */
15451 		len = 0;
15452 	} else {
15453 		uint32_t flight;
15454 
15455 		flight = ctf_flight_size(tp, rack->r_ctl.rc_sacked);
15456 		if (flight >= sendwin) {
15457 			/*
15458 			 * We have in flight what we are allowed by cwnd (if
15459 			 * it was rwnd blocking it would have hit above out
15460 			 * >= tp->snd_wnd).
15461 			 */
15462 			return (0);
15463 		}
15464 		len = sendwin - flight;
15465 		if ((len + ctf_outstanding(tp)) > tp->snd_wnd) {
15466 			/* We would send too much (beyond the rwnd) */
15467 			len = tp->snd_wnd - ctf_outstanding(tp);
15468 		}
15469 		if ((len + sb_offset) > avail) {
15470 			/*
15471 			 * We don't have that much in the SB, how much is
15472 			 * there?
15473 			 */
15474 			len = avail - sb_offset;
15475 		}
15476 	}
15477 	return (len);
15478 }
15479 
15480 static void
15481 rack_log_fsb(struct tcp_rack *rack, struct tcpcb *tp, struct socket *so, uint32_t flags,
15482 	     unsigned ipoptlen, int32_t orig_len, int32_t len, int error,
15483 	     int rsm_is_null, int optlen, int line, uint16_t mode)
15484 {
15485 	if (tp->t_logstate != TCP_LOG_STATE_OFF) {
15486 		union tcp_log_stackspecific log;
15487 		struct timeval tv;
15488 
15489 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
15490 		log.u_bbr.inhpts = rack->rc_inp->inp_in_hpts;
15491 		log.u_bbr.ininput = rack->rc_inp->inp_in_input;
15492 		log.u_bbr.flex1 = error;
15493 		log.u_bbr.flex2 = flags;
15494 		log.u_bbr.flex3 = rsm_is_null;
15495 		log.u_bbr.flex4 = ipoptlen;
15496 		log.u_bbr.flex5 = tp->rcv_numsacks;
15497 		log.u_bbr.flex6 = rack->r_ctl.rc_agg_early;
15498 		log.u_bbr.flex7 = optlen;
15499 		log.u_bbr.flex8 = rack->r_fsb_inited;
15500 		log.u_bbr.applimited = rack->r_fast_output;
15501 		log.u_bbr.bw_inuse = rack_get_bw(rack);
15502 		log.u_bbr.pacing_gain = rack_get_output_gain(rack, NULL);
15503 		log.u_bbr.cwnd_gain = mode;
15504 		log.u_bbr.pkts_out = orig_len;
15505 		log.u_bbr.lt_epoch = len;
15506 		log.u_bbr.delivered = line;
15507 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
15508 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
15509 		tcp_log_event_(tp, NULL, &so->so_rcv, &so->so_snd, TCP_LOG_FSB, 0,
15510 			       len, &log, false, NULL, NULL, 0, &tv);
15511 	}
15512 }
15513 
15514 
15515 static struct mbuf *
15516 rack_fo_base_copym(struct mbuf *the_m, uint32_t the_off, int32_t *plen,
15517 		   struct rack_fast_send_blk *fsb,
15518 		   int32_t seglimit, int32_t segsize, int hw_tls)
15519 {
15520 #ifdef KERN_TLS
15521 	struct ktls_session *tls, *ntls;
15522 	struct mbuf *start;
15523 #endif
15524 	struct mbuf *m, *n, **np, *smb;
15525 	struct mbuf *top;
15526 	int32_t off, soff;
15527 	int32_t len = *plen;
15528 	int32_t fragsize;
15529 	int32_t len_cp = 0;
15530 	uint32_t mlen, frags;
15531 
15532 	soff = off = the_off;
15533 	smb = m = the_m;
15534 	np = &top;
15535 	top = NULL;
15536 #ifdef KERN_TLS
15537 	if (hw_tls && (m->m_flags & M_EXTPG))
15538 		tls = m->m_epg_tls;
15539 	else
15540 		tls = NULL;
15541 	start = m;
15542 #endif
15543 	while (len > 0) {
15544 		if (m == NULL) {
15545 			*plen = len_cp;
15546 			break;
15547 		}
15548 #ifdef KERN_TLS
15549 		if (hw_tls) {
15550 			if (m->m_flags & M_EXTPG)
15551 				ntls = m->m_epg_tls;
15552 			else
15553 				ntls = NULL;
15554 
15555 			/*
15556 			 * Avoid mixing TLS records with handshake
15557 			 * data or TLS records from different
15558 			 * sessions.
15559 			 */
15560 			if (tls != ntls) {
15561 				MPASS(m != start);
15562 				*plen = len_cp;
15563 				break;
15564 			}
15565 		}
15566 #endif
15567 		mlen = min(len, m->m_len - off);
15568 		if (seglimit) {
15569 			/*
15570 			 * For M_EXTPG mbufs, add 3 segments
15571 			 * + 1 in case we are crossing page boundaries
15572 			 * + 2 in case the TLS hdr/trailer are used
15573 			 * It is cheaper to just add the segments
15574 			 * than it is to take the cache miss to look
15575 			 * at the mbuf ext_pgs state in detail.
15576 			 */
15577 			if (m->m_flags & M_EXTPG) {
15578 				fragsize = min(segsize, PAGE_SIZE);
15579 				frags = 3;
15580 			} else {
15581 				fragsize = segsize;
15582 				frags = 0;
15583 			}
15584 
15585 			/* Break if we really can't fit anymore. */
15586 			if ((frags + 1) >= seglimit) {
15587 				*plen =	len_cp;
15588 				break;
15589 			}
15590 
15591 			/*
15592 			 * Reduce size if you can't copy the whole
15593 			 * mbuf. If we can't copy the whole mbuf, also
15594 			 * adjust len so the loop will end after this
15595 			 * mbuf.
15596 			 */
15597 			if ((frags + howmany(mlen, fragsize)) >= seglimit) {
15598 				mlen = (seglimit - frags - 1) * fragsize;
15599 				len = mlen;
15600 				*plen = len_cp + len;
15601 			}
15602 			frags += howmany(mlen, fragsize);
15603 			if (frags == 0)
15604 				frags++;
15605 			seglimit -= frags;
15606 			KASSERT(seglimit > 0,
15607 			    ("%s: seglimit went too low", __func__));
15608 		}
15609 		n = m_get(M_NOWAIT, m->m_type);
15610 		*np = n;
15611 		if (n == NULL)
15612 			goto nospace;
15613 		n->m_len = mlen;
15614 		soff += mlen;
15615 		len_cp += n->m_len;
15616 		if (m->m_flags & (M_EXT|M_EXTPG)) {
15617 			n->m_data = m->m_data + off;
15618 			mb_dupcl(n, m);
15619 		} else {
15620 			bcopy(mtod(m, caddr_t)+off, mtod(n, caddr_t),
15621 			    (u_int)n->m_len);
15622 		}
15623 		len -= n->m_len;
15624 		off = 0;
15625 		m = m->m_next;
15626 		np = &n->m_next;
15627 		if (len || (soff == smb->m_len)) {
15628 			/*
15629 			 * We have more so we move forward  or
15630 			 * we have consumed the entire mbuf and
15631 			 * len has fell to 0.
15632 			 */
15633 			soff = 0;
15634 			smb = m;
15635 		}
15636 
15637 	}
15638 	if (fsb != NULL) {
15639 		fsb->m = smb;
15640 		fsb->off = soff;
15641 		if (smb) {
15642 			/*
15643 			 * Save off the size of the mbuf. We do
15644 			 * this so that we can recognize when it
15645 			 * has been trimmed by sbcut() as acks
15646 			 * come in.
15647 			 */
15648 			fsb->o_m_len = smb->m_len;
15649 		} else {
15650 			/*
15651 			 * This is the case where the next mbuf went to NULL. This
15652 			 * means with this copy we have sent everything in the sb.
15653 			 * In theory we could clear the fast_output flag, but lets
15654 			 * not since its possible that we could get more added
15655 			 * and acks that call the extend function which would let
15656 			 * us send more.
15657 			 */
15658 			fsb->o_m_len = 0;
15659 		}
15660 	}
15661 	return (top);
15662 nospace:
15663 	if (top)
15664 		m_freem(top);
15665 	return (NULL);
15666 
15667 }
15668 
15669 /*
15670  * This is a copy of m_copym(), taking the TSO segment size/limit
15671  * constraints into account, and advancing the sndptr as it goes.
15672  */
15673 static struct mbuf *
15674 rack_fo_m_copym(struct tcp_rack *rack, int32_t *plen,
15675 		int32_t seglimit, int32_t segsize, struct mbuf **s_mb, int *s_soff)
15676 {
15677 	struct mbuf *m, *n;
15678 	int32_t soff;
15679 
15680 	soff = rack->r_ctl.fsb.off;
15681 	m = rack->r_ctl.fsb.m;
15682 	if (rack->r_ctl.fsb.o_m_len > m->m_len) {
15683 		/*
15684 		 * The mbuf had the front of it chopped off by an ack
15685 		 * we need to adjust the soff/off by that difference.
15686 		 */
15687 		uint32_t delta;
15688 
15689 		delta = rack->r_ctl.fsb.o_m_len - m->m_len;
15690 		soff -= delta;
15691 	} else if (rack->r_ctl.fsb.o_m_len < m->m_len) {
15692 		/*
15693 		 * The mbuf was expanded probably by
15694 		 * a m_compress. Just update o_m_len.
15695 		 */
15696 		rack->r_ctl.fsb.o_m_len = m->m_len;
15697 	}
15698 	KASSERT(soff >= 0, ("%s, negative off %d", __FUNCTION__, soff));
15699 	KASSERT(*plen >= 0, ("%s, negative len %d", __FUNCTION__, *plen));
15700 	KASSERT(soff < m->m_len, ("%s rack:%p len:%u m:%p m->m_len:%u < off?",
15701 				 __FUNCTION__,
15702 				 rack, *plen, m, m->m_len));
15703 	/* Save off the right location before we copy and advance */
15704 	*s_soff = soff;
15705 	*s_mb = rack->r_ctl.fsb.m;
15706 	n = rack_fo_base_copym(m, soff, plen,
15707 			       &rack->r_ctl.fsb,
15708 			       seglimit, segsize, rack->r_ctl.fsb.hw_tls);
15709 	return (n);
15710 }
15711 
15712 static int
15713 rack_fast_rsm_output(struct tcpcb *tp, struct tcp_rack *rack, struct rack_sendmap *rsm,
15714 		     uint64_t ts_val, uint32_t cts, uint32_t ms_cts, struct timeval *tv, int len, uint8_t doing_tlp)
15715 {
15716 	/*
15717 	 * Enter the fast retransmit path. We are given that a sched_pin is
15718 	 * in place (if accounting is compliled in) and the cycle count taken
15719 	 * at the entry is in the ts_val. The concept her is that the rsm
15720 	 * now holds the mbuf offsets and such so we can directly transmit
15721 	 * without a lot of overhead, the len field is already set for
15722 	 * us to prohibit us from sending too much (usually its 1MSS).
15723 	 */
15724 	struct ip *ip = NULL;
15725 	struct udphdr *udp = NULL;
15726 	struct tcphdr *th = NULL;
15727 	struct mbuf *m = NULL;
15728 	struct inpcb *inp;
15729 	uint8_t *cpto;
15730 	struct tcp_log_buffer *lgb;
15731 #ifdef TCP_ACCOUNTING
15732 	uint64_t crtsc;
15733 	int cnt_thru = 1;
15734 #endif
15735 	struct tcpopt to;
15736 	u_char opt[TCP_MAXOLEN];
15737 	uint32_t hdrlen, optlen;
15738 	int32_t slot, segsiz, max_val, tso = 0, error, flags, ulen = 0;
15739 	uint32_t us_cts;
15740 	uint32_t if_hw_tsomaxsegcount = 0, startseq;
15741 	uint32_t if_hw_tsomaxsegsize;
15742 
15743 #ifdef INET6
15744 	struct ip6_hdr *ip6 = NULL;
15745 
15746 	if (rack->r_is_v6) {
15747 		ip6 = (struct ip6_hdr *)rack->r_ctl.fsb.tcp_ip_hdr;
15748 		hdrlen = sizeof(struct ip6_hdr) + sizeof(struct tcphdr);
15749 	} else
15750 #endif				/* INET6 */
15751 	{
15752 		ip = (struct ip *)rack->r_ctl.fsb.tcp_ip_hdr;
15753 		hdrlen = sizeof(struct tcpiphdr);
15754 	}
15755 	if (tp->t_port && (V_tcp_udp_tunneling_port == 0)) {
15756 		goto failed;
15757 	}
15758 	if (doing_tlp) {
15759 		/* Its a TLP add the flag, it may already be there but be sure */
15760 		rsm->r_flags |= RACK_TLP;
15761 	} else {
15762 		/* If it was a TLP it is not not on this retransmit */
15763 		rsm->r_flags &= ~RACK_TLP;
15764 	}
15765 	startseq = rsm->r_start;
15766 	segsiz = min(ctf_fixed_maxseg(tp), rack->r_ctl.rc_pace_min_segs);
15767 	inp = rack->rc_inp;
15768 	to.to_flags = 0;
15769 	flags = tcp_outflags[tp->t_state];
15770 	if (flags & (TH_SYN|TH_RST)) {
15771 		goto failed;
15772 	}
15773 	if (rsm->r_flags & RACK_HAS_FIN) {
15774 		/* We can't send a FIN here */
15775 		goto failed;
15776 	}
15777 	if (flags & TH_FIN) {
15778 		/* We never send a FIN */
15779 		flags &= ~TH_FIN;
15780 	}
15781 	if (tp->t_flags & TF_RCVD_TSTMP) {
15782 		to.to_tsval = ms_cts + tp->ts_offset;
15783 		to.to_tsecr = tp->ts_recent;
15784 		to.to_flags = TOF_TS;
15785 	}
15786 	optlen = tcp_addoptions(&to, opt);
15787 	hdrlen += optlen;
15788 	udp = rack->r_ctl.fsb.udp;
15789 	if (udp)
15790 		hdrlen += sizeof(struct udphdr);
15791 	if (rack->r_ctl.rc_pace_max_segs)
15792 		max_val = rack->r_ctl.rc_pace_max_segs;
15793 	else if (rack->rc_user_set_max_segs)
15794 		max_val = rack->rc_user_set_max_segs * segsiz;
15795 	else
15796 		max_val = len;
15797 	if ((tp->t_flags & TF_TSO) &&
15798 	    V_tcp_do_tso &&
15799 	    (len > segsiz) &&
15800 	    (tp->t_port == 0))
15801 		tso = 1;
15802 #ifdef INET6
15803 	if (MHLEN < hdrlen + max_linkhdr)
15804 		m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR);
15805 	else
15806 #endif
15807 		m = m_gethdr(M_NOWAIT, MT_DATA);
15808 	if (m == NULL)
15809 		goto failed;
15810 	m->m_data += max_linkhdr;
15811 	m->m_len = hdrlen;
15812 	th = rack->r_ctl.fsb.th;
15813 	/* Establish the len to send */
15814 	if (len > max_val)
15815 		len = max_val;
15816 	if ((tso) && (len + optlen > tp->t_maxseg)) {
15817 		uint32_t if_hw_tsomax;
15818 		int32_t max_len;
15819 
15820 		/* extract TSO information */
15821 		if_hw_tsomax = tp->t_tsomax;
15822 		if_hw_tsomaxsegcount = tp->t_tsomaxsegcount;
15823 		if_hw_tsomaxsegsize = tp->t_tsomaxsegsize;
15824 		/*
15825 		 * Check if we should limit by maximum payload
15826 		 * length:
15827 		 */
15828 		if (if_hw_tsomax != 0) {
15829 			/* compute maximum TSO length */
15830 			max_len = (if_hw_tsomax - hdrlen -
15831 				   max_linkhdr);
15832 			if (max_len <= 0) {
15833 				goto failed;
15834 			} else if (len > max_len) {
15835 				len = max_len;
15836 			}
15837 		}
15838 		if (len <= segsiz) {
15839 			/*
15840 			 * In case there are too many small fragments don't
15841 			 * use TSO:
15842 			 */
15843 			tso = 0;
15844 		}
15845 	} else {
15846 		tso = 0;
15847 	}
15848 	if ((tso == 0) && (len > segsiz))
15849 		len = segsiz;
15850 	us_cts = tcp_get_usecs(tv);
15851 	if ((len == 0) ||
15852 	    (len <= MHLEN - hdrlen - max_linkhdr)) {
15853 		goto failed;
15854 	}
15855 	th->th_seq = htonl(rsm->r_start);
15856 	th->th_ack = htonl(tp->rcv_nxt);
15857 	/*
15858 	 * The PUSH bit should only be applied
15859 	 * if the full retransmission is made. If
15860 	 * we are sending less than this is the
15861 	 * left hand edge and should not have
15862 	 * the PUSH bit.
15863 	 */
15864 	if ((rsm->r_flags & RACK_HAD_PUSH) &&
15865 	    (len == (rsm->r_end - rsm->r_start)))
15866 		flags |= TH_PUSH;
15867 	th->th_flags = flags;
15868 	th->th_win = htons((u_short)(rack->r_ctl.fsb.recwin >> tp->rcv_scale));
15869 	if (th->th_win == 0) {
15870 		tp->t_sndzerowin++;
15871 		tp->t_flags |= TF_RXWIN0SENT;
15872 	} else
15873 		tp->t_flags &= ~TF_RXWIN0SENT;
15874 	if (rsm->r_flags & RACK_TLP) {
15875 		/*
15876 		 * TLP should not count in retran count, but
15877 		 * in its own bin
15878 		 */
15879 		counter_u64_add(rack_tlp_retran, 1);
15880 		counter_u64_add(rack_tlp_retran_bytes, len);
15881 	} else {
15882 		tp->t_sndrexmitpack++;
15883 		KMOD_TCPSTAT_INC(tcps_sndrexmitpack);
15884 		KMOD_TCPSTAT_ADD(tcps_sndrexmitbyte, len);
15885 	}
15886 #ifdef STATS
15887 	stats_voi_update_abs_u32(tp->t_stats, VOI_TCP_RETXPB,
15888 				 len);
15889 #endif
15890 	if (rsm->m == NULL)
15891 		goto failed;
15892 	if (rsm->orig_m_len != rsm->m->m_len) {
15893 		/* Fix up the orig_m_len and possibly the mbuf offset */
15894 		rack_adjust_orig_mlen(rsm);
15895 	}
15896 	m->m_next = rack_fo_base_copym(rsm->m, rsm->soff, &len, NULL, if_hw_tsomaxsegcount, if_hw_tsomaxsegsize, rsm->r_hw_tls);
15897 	if (len <= segsiz) {
15898 		/*
15899 		 * Must have ran out of mbufs for the copy
15900 		 * shorten it to no longer need tso. Lets
15901 		 * not put on sendalot since we are low on
15902 		 * mbufs.
15903 		 */
15904 		tso = 0;
15905 	}
15906 	if ((m->m_next == NULL) || (len <= 0)){
15907 		goto failed;
15908 	}
15909 	if (udp) {
15910 		if (rack->r_is_v6)
15911 			ulen = hdrlen + len - sizeof(struct ip6_hdr);
15912 		else
15913 			ulen = hdrlen + len - sizeof(struct ip);
15914 		udp->uh_ulen = htons(ulen);
15915 	}
15916 	m->m_pkthdr.rcvif = (struct ifnet *)0;
15917 	m->m_pkthdr.len = hdrlen + len;	/* in6_cksum() need this */
15918 #ifdef INET6
15919 	if (rack->r_is_v6) {
15920 		if (tp->t_port) {
15921 			m->m_pkthdr.csum_flags = CSUM_UDP_IPV6;
15922 			m->m_pkthdr.csum_data = offsetof(struct udphdr, uh_sum);
15923 			udp->uh_sum = in6_cksum_pseudo(ip6, ulen, IPPROTO_UDP, 0);
15924 			th->th_sum = htons(0);
15925 			UDPSTAT_INC(udps_opackets);
15926 		} else {
15927 			m->m_pkthdr.csum_flags = CSUM_TCP_IPV6;
15928 			m->m_pkthdr.csum_data = offsetof(struct tcphdr, th_sum);
15929 			th->th_sum = in6_cksum_pseudo(ip6,
15930 						      sizeof(struct tcphdr) + optlen + len, IPPROTO_TCP,
15931 						      0);
15932 		}
15933 	}
15934 #endif
15935 #if defined(INET6) && defined(INET)
15936 	else
15937 #endif
15938 #ifdef INET
15939 	{
15940 		if (tp->t_port) {
15941 			m->m_pkthdr.csum_flags = CSUM_UDP;
15942 			m->m_pkthdr.csum_data = offsetof(struct udphdr, uh_sum);
15943 			udp->uh_sum = in_pseudo(ip->ip_src.s_addr,
15944 						ip->ip_dst.s_addr, htons(ulen + IPPROTO_UDP));
15945 			th->th_sum = htons(0);
15946 			UDPSTAT_INC(udps_opackets);
15947 		} else {
15948 			m->m_pkthdr.csum_flags = CSUM_TCP;
15949 			m->m_pkthdr.csum_data = offsetof(struct tcphdr, th_sum);
15950 			th->th_sum = in_pseudo(ip->ip_src.s_addr,
15951 					       ip->ip_dst.s_addr, htons(sizeof(struct tcphdr) +
15952 									IPPROTO_TCP + len + optlen));
15953 		}
15954 		/* IP version must be set here for ipv4/ipv6 checking later */
15955 		KASSERT(ip->ip_v == IPVERSION,
15956 			("%s: IP version incorrect: %d", __func__, ip->ip_v));
15957 	}
15958 #endif
15959 	if (tso) {
15960 		KASSERT(len > tp->t_maxseg - optlen,
15961 			("%s: len <= tso_segsz tp:%p", __func__, tp));
15962 		m->m_pkthdr.csum_flags |= CSUM_TSO;
15963 		m->m_pkthdr.tso_segsz = tp->t_maxseg - optlen;
15964 	}
15965 #ifdef INET6
15966 	if (rack->r_is_v6) {
15967 		ip6->ip6_hlim = rack->r_ctl.fsb.hoplimit;
15968 		ip6->ip6_plen = htons(m->m_pkthdr.len - sizeof(*ip6));
15969 		if (V_path_mtu_discovery && tp->t_maxseg > V_tcp_minmss)
15970 			tp->t_flags2 |= TF2_PLPMTU_PMTUD;
15971 		else
15972 			tp->t_flags2 &= ~TF2_PLPMTU_PMTUD;
15973 	}
15974 #endif
15975 #if defined(INET) && defined(INET6)
15976 	else
15977 #endif
15978 #ifdef INET
15979 	{
15980 		ip->ip_len = htons(m->m_pkthdr.len);
15981 		ip->ip_ttl = rack->r_ctl.fsb.hoplimit;
15982 		if (V_path_mtu_discovery && tp->t_maxseg > V_tcp_minmss) {
15983 			tp->t_flags2 |= TF2_PLPMTU_PMTUD;
15984 			if (tp->t_port == 0 || len < V_tcp_minmss) {
15985 				ip->ip_off |= htons(IP_DF);
15986 			}
15987 		} else {
15988 			tp->t_flags2 &= ~TF2_PLPMTU_PMTUD;
15989 		}
15990 	}
15991 #endif
15992 	/* Time to copy in our header */
15993 	cpto = mtod(m, uint8_t *);
15994 	memcpy(cpto, rack->r_ctl.fsb.tcp_ip_hdr, rack->r_ctl.fsb.tcp_ip_hdr_len);
15995 	th = (struct tcphdr *)(cpto + ((uint8_t *)rack->r_ctl.fsb.th - rack->r_ctl.fsb.tcp_ip_hdr));
15996 	if (optlen) {
15997 		bcopy(opt, th + 1, optlen);
15998 		th->th_off = (sizeof(struct tcphdr) + optlen) >> 2;
15999 	} else {
16000 		th->th_off = sizeof(struct tcphdr) >> 2;
16001 	}
16002 	if (tp->t_logstate != TCP_LOG_STATE_OFF) {
16003 		union tcp_log_stackspecific log;
16004 
16005 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
16006 		log.u_bbr.inhpts = rack->rc_inp->inp_in_hpts;
16007 		log.u_bbr.ininput = rack->rc_inp->inp_in_input;
16008 		if (rack->rack_no_prr)
16009 			log.u_bbr.flex1 = 0;
16010 		else
16011 			log.u_bbr.flex1 = rack->r_ctl.rc_prr_sndcnt;
16012 		log.u_bbr.flex2 = rack->r_ctl.rc_pace_min_segs;
16013 		log.u_bbr.flex3 = rack->r_ctl.rc_pace_max_segs;
16014 		log.u_bbr.flex4 = max_val;
16015 		log.u_bbr.flex5 = 0;
16016 		/* Save off the early/late values */
16017 		log.u_bbr.flex6 = rack->r_ctl.rc_agg_early;
16018 		log.u_bbr.applimited = rack->r_ctl.rc_agg_delayed;
16019 		log.u_bbr.bw_inuse = rack_get_bw(rack);
16020 		if (doing_tlp == 0)
16021 			log.u_bbr.flex8 = 1;
16022 		else
16023 			log.u_bbr.flex8 = 2;
16024 		log.u_bbr.pacing_gain = rack_get_output_gain(rack, NULL);
16025 		log.u_bbr.flex7 = 55;
16026 		log.u_bbr.pkts_out = tp->t_maxseg;
16027 		log.u_bbr.timeStamp = cts;
16028 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
16029 		log.u_bbr.lt_epoch = rack->r_ctl.cwnd_to_use;
16030 		log.u_bbr.delivered = 0;
16031 		lgb = tcp_log_event_(tp, th, NULL, NULL, TCP_LOG_OUT, ERRNO_UNK,
16032 				     len, &log, false, NULL, NULL, 0, tv);
16033 	} else
16034 		lgb = NULL;
16035 #ifdef INET6
16036 	if (rack->r_is_v6) {
16037 		error = ip6_output(m, NULL,
16038 				   &inp->inp_route6,
16039 				   0, NULL, NULL, inp);
16040 	}
16041 #endif
16042 #if defined(INET) && defined(INET6)
16043 	else
16044 #endif
16045 #ifdef INET
16046 	{
16047 		error = ip_output(m, NULL,
16048 				  &inp->inp_route,
16049 				  0, 0, inp);
16050 	}
16051 #endif
16052 	m = NULL;
16053 	if (lgb) {
16054 		lgb->tlb_errno = error;
16055 		lgb = NULL;
16056 	}
16057 	if (error) {
16058 		goto failed;
16059 	}
16060 	rack_log_output(tp, &to, len, rsm->r_start, flags, error, rack_to_usec_ts(tv),
16061 			rsm, RACK_SENT_FP, rsm->m, rsm->soff, rsm->r_hw_tls);
16062 	if (doing_tlp && (rack->fast_rsm_hack == 0)) {
16063 		rack->rc_tlp_in_progress = 1;
16064 		rack->r_ctl.rc_tlp_cnt_out++;
16065 	}
16066 	if (error == 0) {
16067 		tcp_account_for_send(tp, len, 1, doing_tlp, rsm->r_hw_tls);
16068 		if (doing_tlp) {
16069 			rack->rc_last_sent_tlp_past_cumack = 0;
16070 			rack->rc_last_sent_tlp_seq_valid = 1;
16071 			rack->r_ctl.last_sent_tlp_seq = rsm->r_start;
16072 			rack->r_ctl.last_sent_tlp_len = rsm->r_end - rsm->r_start;
16073 		}
16074 	}
16075 	tp->t_flags &= ~(TF_ACKNOW | TF_DELACK);
16076 	rack->forced_ack = 0;	/* If we send something zap the FA flag */
16077 	if (IN_FASTRECOVERY(tp->t_flags) && rsm)
16078 		rack->r_ctl.retran_during_recovery += len;
16079 	{
16080 		int idx;
16081 
16082 		idx = (len / segsiz) + 3;
16083 		if (idx >= TCP_MSS_ACCT_ATIMER)
16084 			counter_u64_add(rack_out_size[(TCP_MSS_ACCT_ATIMER-1)], 1);
16085 		else
16086 			counter_u64_add(rack_out_size[idx], 1);
16087 	}
16088 	if (tp->t_rtttime == 0) {
16089 		tp->t_rtttime = ticks;
16090 		tp->t_rtseq = startseq;
16091 		KMOD_TCPSTAT_INC(tcps_segstimed);
16092 	}
16093 	counter_u64_add(rack_fto_rsm_send, 1);
16094 	if (error && (error == ENOBUFS)) {
16095 		slot = ((1 + rack->rc_enobuf) * HPTS_USEC_IN_MSEC);
16096 		if (rack->rc_enobuf < 0x7f)
16097 			rack->rc_enobuf++;
16098 		if (slot < (10 * HPTS_USEC_IN_MSEC))
16099 			slot = 10 * HPTS_USEC_IN_MSEC;
16100 	} else
16101 		slot = rack_get_pacing_delay(rack, tp, len, NULL, segsiz);
16102 	if ((slot == 0) ||
16103 	    (rack->rc_always_pace == 0) ||
16104 	    (rack->r_rr_config == 1)) {
16105 		/*
16106 		 * We have no pacing set or we
16107 		 * are using old-style rack or
16108 		 * we are overriden to use the old 1ms pacing.
16109 		 */
16110 		slot = rack->r_ctl.rc_min_to;
16111 	}
16112 	rack_start_hpts_timer(rack, tp, cts, slot, len, 0);
16113 	if (rack->r_must_retran) {
16114 		rack->r_ctl.rc_out_at_rto -= (rsm->r_end - rsm->r_start);
16115 		if ((SEQ_GEQ(rsm->r_end, rack->r_ctl.rc_snd_max_at_rto)) ||
16116 		    ((rsm->r_flags & RACK_MUST_RXT) == 0)) {
16117 			/*
16118 			 * We have retransmitted all we need. If
16119 			 * RACK_MUST_RXT is not set then we need to
16120 			 * not retransmit this guy.
16121 			 */
16122 			rack->r_must_retran = 0;
16123 			rack->r_ctl.rc_out_at_rto = 0;
16124 			if ((rsm->r_flags & RACK_MUST_RXT) == 0) {
16125 				/* Not one we should rxt */
16126 				goto failed;
16127 			} else {
16128 				/* Clear the flag */
16129 				rsm->r_flags &= ~RACK_MUST_RXT;
16130 			}
16131 		} else {
16132 			/* Remove  the flag */
16133 			rsm->r_flags &= ~RACK_MUST_RXT;
16134 		}
16135 	}
16136 #ifdef TCP_ACCOUNTING
16137 	crtsc = get_cyclecount();
16138 	if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
16139 		tp->tcp_cnt_counters[SND_OUT_DATA] += cnt_thru;
16140 	}
16141 	counter_u64_add(tcp_cnt_counters[SND_OUT_DATA], cnt_thru);
16142 	if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
16143 		tp->tcp_proc_time[SND_OUT_DATA] += (crtsc - ts_val);
16144 	}
16145 	counter_u64_add(tcp_proc_time[SND_OUT_DATA], (crtsc - ts_val));
16146 	if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
16147 		tp->tcp_cnt_counters[CNT_OF_MSS_OUT] += ((len + segsiz - 1) / segsiz);
16148 	}
16149 	counter_u64_add(tcp_cnt_counters[CNT_OF_MSS_OUT], ((len + segsiz - 1) / segsiz));
16150 	sched_unpin();
16151 #endif
16152 	return (0);
16153 failed:
16154 	if (m)
16155 		m_free(m);
16156 	return (-1);
16157 }
16158 
16159 static void
16160 rack_sndbuf_autoscale(struct tcp_rack *rack)
16161 {
16162 	/*
16163 	 * Automatic sizing of send socket buffer.  Often the send buffer
16164 	 * size is not optimally adjusted to the actual network conditions
16165 	 * at hand (delay bandwidth product).  Setting the buffer size too
16166 	 * small limits throughput on links with high bandwidth and high
16167 	 * delay (eg. trans-continental/oceanic links).  Setting the
16168 	 * buffer size too big consumes too much real kernel memory,
16169 	 * especially with many connections on busy servers.
16170 	 *
16171 	 * The criteria to step up the send buffer one notch are:
16172 	 *  1. receive window of remote host is larger than send buffer
16173 	 *     (with a fudge factor of 5/4th);
16174 	 *  2. send buffer is filled to 7/8th with data (so we actually
16175 	 *     have data to make use of it);
16176 	 *  3. send buffer fill has not hit maximal automatic size;
16177 	 *  4. our send window (slow start and cogestion controlled) is
16178 	 *     larger than sent but unacknowledged data in send buffer.
16179 	 *
16180 	 * Note that the rack version moves things much faster since
16181 	 * we want to avoid hitting cache lines in the rack_fast_output()
16182 	 * path so this is called much less often and thus moves
16183 	 * the SB forward by a percentage.
16184 	 */
16185 	struct socket *so;
16186 	struct tcpcb *tp;
16187 	uint32_t sendwin, scaleup;
16188 
16189 	tp = rack->rc_tp;
16190 	so = rack->rc_inp->inp_socket;
16191 	sendwin = min(rack->r_ctl.cwnd_to_use, tp->snd_wnd);
16192 	if (V_tcp_do_autosndbuf && so->so_snd.sb_flags & SB_AUTOSIZE) {
16193 		if ((tp->snd_wnd / 4 * 5) >= so->so_snd.sb_hiwat &&
16194 		    sbused(&so->so_snd) >=
16195 		    (so->so_snd.sb_hiwat / 8 * 7) &&
16196 		    sbused(&so->so_snd) < V_tcp_autosndbuf_max &&
16197 		    sendwin >= (sbused(&so->so_snd) -
16198 		    (tp->snd_nxt - tp->snd_una))) {
16199 			if (rack_autosndbuf_inc)
16200 				scaleup = (rack_autosndbuf_inc * so->so_snd.sb_hiwat) / 100;
16201 			else
16202 				scaleup = V_tcp_autosndbuf_inc;
16203 			if (scaleup < V_tcp_autosndbuf_inc)
16204 				scaleup = V_tcp_autosndbuf_inc;
16205 			scaleup += so->so_snd.sb_hiwat;
16206 			if (scaleup > V_tcp_autosndbuf_max)
16207 				scaleup = V_tcp_autosndbuf_max;
16208 			if (!sbreserve_locked(&so->so_snd, scaleup, so, curthread))
16209 				so->so_snd.sb_flags &= ~SB_AUTOSIZE;
16210 		}
16211 	}
16212 }
16213 
16214 static int
16215 rack_fast_output(struct tcpcb *tp, struct tcp_rack *rack, uint64_t ts_val,
16216 		 uint32_t cts, uint32_t ms_cts, struct timeval *tv, long tot_len, int *send_err)
16217 {
16218 	/*
16219 	 * Enter to do fast output. We are given that the sched_pin is
16220 	 * in place (if accounting is compiled in) and the cycle count taken
16221 	 * at entry is in place in ts_val. The idea here is that
16222 	 * we know how many more bytes needs to be sent (presumably either
16223 	 * during pacing or to fill the cwnd and that was greater than
16224 	 * the max-burst). We have how much to send and all the info we
16225 	 * need to just send.
16226 	 */
16227 	struct ip *ip = NULL;
16228 	struct udphdr *udp = NULL;
16229 	struct tcphdr *th = NULL;
16230 	struct mbuf *m, *s_mb;
16231 	struct inpcb *inp;
16232 	uint8_t *cpto;
16233 	struct tcp_log_buffer *lgb;
16234 #ifdef TCP_ACCOUNTING
16235 	uint64_t crtsc;
16236 #endif
16237 	struct tcpopt to;
16238 	u_char opt[TCP_MAXOLEN];
16239 	uint32_t hdrlen, optlen;
16240 	int cnt_thru = 1;
16241 	int32_t slot, segsiz, len, max_val, tso = 0, sb_offset, error, flags, ulen = 0;
16242 	uint32_t us_cts, s_soff;
16243 	uint32_t if_hw_tsomaxsegcount = 0, startseq;
16244 	uint32_t if_hw_tsomaxsegsize;
16245 	uint16_t add_flag = RACK_SENT_FP;
16246 #ifdef INET6
16247 	struct ip6_hdr *ip6 = NULL;
16248 
16249 	if (rack->r_is_v6) {
16250 		ip6 = (struct ip6_hdr *)rack->r_ctl.fsb.tcp_ip_hdr;
16251 		hdrlen = sizeof(struct ip6_hdr) + sizeof(struct tcphdr);
16252 	} else
16253 #endif				/* INET6 */
16254 	{
16255 		ip = (struct ip *)rack->r_ctl.fsb.tcp_ip_hdr;
16256 		hdrlen = sizeof(struct tcpiphdr);
16257 	}
16258 	if (tp->t_port && (V_tcp_udp_tunneling_port == 0)) {
16259 		m = NULL;
16260 		goto failed;
16261 	}
16262 	startseq = tp->snd_max;
16263 	segsiz = min(ctf_fixed_maxseg(tp), rack->r_ctl.rc_pace_min_segs);
16264 	inp = rack->rc_inp;
16265 	len = rack->r_ctl.fsb.left_to_send;
16266 	to.to_flags = 0;
16267 	flags = rack->r_ctl.fsb.tcp_flags;
16268 	if (tp->t_flags & TF_RCVD_TSTMP) {
16269 		to.to_tsval = ms_cts + tp->ts_offset;
16270 		to.to_tsecr = tp->ts_recent;
16271 		to.to_flags = TOF_TS;
16272 	}
16273 	optlen = tcp_addoptions(&to, opt);
16274 	hdrlen += optlen;
16275 	udp = rack->r_ctl.fsb.udp;
16276 	if (udp)
16277 		hdrlen += sizeof(struct udphdr);
16278 	if (rack->r_ctl.rc_pace_max_segs)
16279 		max_val = rack->r_ctl.rc_pace_max_segs;
16280 	else if (rack->rc_user_set_max_segs)
16281 		max_val = rack->rc_user_set_max_segs * segsiz;
16282 	else
16283 		max_val = len;
16284 	if ((tp->t_flags & TF_TSO) &&
16285 	    V_tcp_do_tso &&
16286 	    (len > segsiz) &&
16287 	    (tp->t_port == 0))
16288 		tso = 1;
16289 again:
16290 #ifdef INET6
16291 	if (MHLEN < hdrlen + max_linkhdr)
16292 		m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR);
16293 	else
16294 #endif
16295 		m = m_gethdr(M_NOWAIT, MT_DATA);
16296 	if (m == NULL)
16297 		goto failed;
16298 	m->m_data += max_linkhdr;
16299 	m->m_len = hdrlen;
16300 	th = rack->r_ctl.fsb.th;
16301 	/* Establish the len to send */
16302 	if (len > max_val)
16303 		len = max_val;
16304 	if ((tso) && (len + optlen > tp->t_maxseg)) {
16305 		uint32_t if_hw_tsomax;
16306 		int32_t max_len;
16307 
16308 		/* extract TSO information */
16309 		if_hw_tsomax = tp->t_tsomax;
16310 		if_hw_tsomaxsegcount = tp->t_tsomaxsegcount;
16311 		if_hw_tsomaxsegsize = tp->t_tsomaxsegsize;
16312 		/*
16313 		 * Check if we should limit by maximum payload
16314 		 * length:
16315 		 */
16316 		if (if_hw_tsomax != 0) {
16317 			/* compute maximum TSO length */
16318 			max_len = (if_hw_tsomax - hdrlen -
16319 				   max_linkhdr);
16320 			if (max_len <= 0) {
16321 				goto failed;
16322 			} else if (len > max_len) {
16323 				len = max_len;
16324 			}
16325 		}
16326 		if (len <= segsiz) {
16327 			/*
16328 			 * In case there are too many small fragments don't
16329 			 * use TSO:
16330 			 */
16331 			tso = 0;
16332 		}
16333 	} else {
16334 		tso = 0;
16335 	}
16336 	if ((tso == 0) && (len > segsiz))
16337 		len = segsiz;
16338 	us_cts = tcp_get_usecs(tv);
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_flags = flags;
16347 	th->th_win = htons((u_short)(rack->r_ctl.fsb.recwin >> tp->rcv_scale));
16348 	if (th->th_win == 0) {
16349 		tp->t_sndzerowin++;
16350 		tp->t_flags |= TF_RXWIN0SENT;
16351 	} else
16352 		tp->t_flags &= ~TF_RXWIN0SENT;
16353 	tp->snd_up = tp->snd_una;	/* drag it along, its deprecated */
16354 	KMOD_TCPSTAT_INC(tcps_sndpack);
16355 	KMOD_TCPSTAT_ADD(tcps_sndbyte, len);
16356 #ifdef STATS
16357 	stats_voi_update_abs_u64(tp->t_stats, VOI_TCP_TXPB,
16358 				 len);
16359 #endif
16360 	if (rack->r_ctl.fsb.m == NULL)
16361 		goto failed;
16362 
16363 	/* s_mb and s_soff are saved for rack_log_output */
16364 	m->m_next = rack_fo_m_copym(rack, &len, if_hw_tsomaxsegcount, if_hw_tsomaxsegsize,
16365 				    &s_mb, &s_soff);
16366 	if (len <= segsiz) {
16367 		/*
16368 		 * Must have ran out of mbufs for the copy
16369 		 * shorten it to no longer need tso. Lets
16370 		 * not put on sendalot since we are low on
16371 		 * mbufs.
16372 		 */
16373 		tso = 0;
16374 	}
16375 	if (rack->r_ctl.fsb.rfo_apply_push &&
16376 	    (len == rack->r_ctl.fsb.left_to_send)) {
16377 		th->th_flags |= TH_PUSH;
16378 		add_flag |= RACK_HAD_PUSH;
16379 	}
16380 	if ((m->m_next == NULL) || (len <= 0)){
16381 		goto failed;
16382 	}
16383 	if (udp) {
16384 		if (rack->r_is_v6)
16385 			ulen = hdrlen + len - sizeof(struct ip6_hdr);
16386 		else
16387 			ulen = hdrlen + len - sizeof(struct ip);
16388 		udp->uh_ulen = htons(ulen);
16389 	}
16390 	m->m_pkthdr.rcvif = (struct ifnet *)0;
16391 	if (tp->t_state == TCPS_ESTABLISHED &&
16392 	    (tp->t_flags2 & TF2_ECN_PERMIT)) {
16393 		/*
16394 		 * If the peer has ECN, mark data packets with ECN capable
16395 		 * transmission (ECT). Ignore pure ack packets,
16396 		 * retransmissions.
16397 		 */
16398 		if (len > 0 && SEQ_GEQ(tp->snd_nxt, tp->snd_max)) {
16399 #ifdef INET6
16400 			if (rack->r_is_v6)
16401 				ip6->ip6_flow |= htonl(IPTOS_ECN_ECT0 << 20);
16402 			else
16403 #endif
16404 				ip->ip_tos |= IPTOS_ECN_ECT0;
16405 			KMOD_TCPSTAT_INC(tcps_ecn_ect0);
16406 			/*
16407 			 * Reply with proper ECN notifications.
16408 			 * Only set CWR on new data segments.
16409 			 */
16410 			if (tp->t_flags2 & TF2_ECN_SND_CWR) {
16411 				flags |= TH_CWR;
16412 				tp->t_flags2 &= ~TF2_ECN_SND_CWR;
16413 			}
16414 		}
16415 		if (tp->t_flags2 & TF2_ECN_SND_ECE)
16416 			flags |= TH_ECE;
16417 	}
16418 	m->m_pkthdr.len = hdrlen + len;	/* in6_cksum() need this */
16419 #ifdef INET6
16420 	if (rack->r_is_v6) {
16421 		if (tp->t_port) {
16422 			m->m_pkthdr.csum_flags = CSUM_UDP_IPV6;
16423 			m->m_pkthdr.csum_data = offsetof(struct udphdr, uh_sum);
16424 			udp->uh_sum = in6_cksum_pseudo(ip6, ulen, IPPROTO_UDP, 0);
16425 			th->th_sum = htons(0);
16426 			UDPSTAT_INC(udps_opackets);
16427 		} else {
16428 			m->m_pkthdr.csum_flags = CSUM_TCP_IPV6;
16429 			m->m_pkthdr.csum_data = offsetof(struct tcphdr, th_sum);
16430 			th->th_sum = in6_cksum_pseudo(ip6,
16431 						      sizeof(struct tcphdr) + optlen + len, IPPROTO_TCP,
16432 						      0);
16433 		}
16434 	}
16435 #endif
16436 #if defined(INET6) && defined(INET)
16437 	else
16438 #endif
16439 #ifdef INET
16440 	{
16441 		if (tp->t_port) {
16442 			m->m_pkthdr.csum_flags = CSUM_UDP;
16443 			m->m_pkthdr.csum_data = offsetof(struct udphdr, uh_sum);
16444 			udp->uh_sum = in_pseudo(ip->ip_src.s_addr,
16445 						ip->ip_dst.s_addr, htons(ulen + IPPROTO_UDP));
16446 			th->th_sum = htons(0);
16447 			UDPSTAT_INC(udps_opackets);
16448 		} else {
16449 			m->m_pkthdr.csum_flags = CSUM_TCP;
16450 			m->m_pkthdr.csum_data = offsetof(struct tcphdr, th_sum);
16451 			th->th_sum = in_pseudo(ip->ip_src.s_addr,
16452 					       ip->ip_dst.s_addr, htons(sizeof(struct tcphdr) +
16453 									IPPROTO_TCP + len + optlen));
16454 		}
16455 		/* IP version must be set here for ipv4/ipv6 checking later */
16456 		KASSERT(ip->ip_v == IPVERSION,
16457 			("%s: IP version incorrect: %d", __func__, ip->ip_v));
16458 	}
16459 #endif
16460 	if (tso) {
16461 		KASSERT(len > tp->t_maxseg - optlen,
16462 			("%s: len <= tso_segsz tp:%p", __func__, tp));
16463 		m->m_pkthdr.csum_flags |= CSUM_TSO;
16464 		m->m_pkthdr.tso_segsz = tp->t_maxseg - optlen;
16465 	}
16466 #ifdef INET6
16467 	if (rack->r_is_v6) {
16468 		ip6->ip6_hlim = rack->r_ctl.fsb.hoplimit;
16469 		ip6->ip6_plen = htons(m->m_pkthdr.len - sizeof(*ip6));
16470 		if (V_path_mtu_discovery && tp->t_maxseg > V_tcp_minmss)
16471 			tp->t_flags2 |= TF2_PLPMTU_PMTUD;
16472 		else
16473 			tp->t_flags2 &= ~TF2_PLPMTU_PMTUD;
16474 	}
16475 #endif
16476 #if defined(INET) && defined(INET6)
16477 	else
16478 #endif
16479 #ifdef INET
16480 	{
16481 		ip->ip_len = htons(m->m_pkthdr.len);
16482 		ip->ip_ttl = rack->r_ctl.fsb.hoplimit;
16483 		if (V_path_mtu_discovery && tp->t_maxseg > V_tcp_minmss) {
16484 			tp->t_flags2 |= TF2_PLPMTU_PMTUD;
16485 			if (tp->t_port == 0 || len < V_tcp_minmss) {
16486 				ip->ip_off |= htons(IP_DF);
16487 			}
16488 		} else {
16489 			tp->t_flags2 &= ~TF2_PLPMTU_PMTUD;
16490 		}
16491 	}
16492 #endif
16493 	/* Time to copy in our header */
16494 	cpto = mtod(m, uint8_t *);
16495 	memcpy(cpto, rack->r_ctl.fsb.tcp_ip_hdr, rack->r_ctl.fsb.tcp_ip_hdr_len);
16496 	th = (struct tcphdr *)(cpto + ((uint8_t *)rack->r_ctl.fsb.th - rack->r_ctl.fsb.tcp_ip_hdr));
16497 	if (optlen) {
16498 		bcopy(opt, th + 1, optlen);
16499 		th->th_off = (sizeof(struct tcphdr) + optlen) >> 2;
16500 	} else {
16501 		th->th_off = sizeof(struct tcphdr) >> 2;
16502 	}
16503 	if (tp->t_logstate != TCP_LOG_STATE_OFF) {
16504 		union tcp_log_stackspecific log;
16505 
16506 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
16507 		log.u_bbr.inhpts = rack->rc_inp->inp_in_hpts;
16508 		log.u_bbr.ininput = rack->rc_inp->inp_in_input;
16509 		if (rack->rack_no_prr)
16510 			log.u_bbr.flex1 = 0;
16511 		else
16512 			log.u_bbr.flex1 = rack->r_ctl.rc_prr_sndcnt;
16513 		log.u_bbr.flex2 = rack->r_ctl.rc_pace_min_segs;
16514 		log.u_bbr.flex3 = rack->r_ctl.rc_pace_max_segs;
16515 		log.u_bbr.flex4 = max_val;
16516 		log.u_bbr.flex5 = 0;
16517 		/* Save off the early/late values */
16518 		log.u_bbr.flex6 = rack->r_ctl.rc_agg_early;
16519 		log.u_bbr.applimited = rack->r_ctl.rc_agg_delayed;
16520 		log.u_bbr.bw_inuse = rack_get_bw(rack);
16521 		log.u_bbr.flex8 = 0;
16522 		log.u_bbr.pacing_gain = rack_get_output_gain(rack, NULL);
16523 		log.u_bbr.flex7 = 44;
16524 		log.u_bbr.pkts_out = tp->t_maxseg;
16525 		log.u_bbr.timeStamp = cts;
16526 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
16527 		log.u_bbr.lt_epoch = rack->r_ctl.cwnd_to_use;
16528 		log.u_bbr.delivered = 0;
16529 		lgb = tcp_log_event_(tp, th, NULL, NULL, TCP_LOG_OUT, ERRNO_UNK,
16530 				     len, &log, false, NULL, NULL, 0, tv);
16531 	} else
16532 		lgb = NULL;
16533 #ifdef INET6
16534 	if (rack->r_is_v6) {
16535 		error = ip6_output(m, NULL,
16536 				   &inp->inp_route6,
16537 				   0, NULL, NULL, inp);
16538 	}
16539 #endif
16540 #if defined(INET) && defined(INET6)
16541 	else
16542 #endif
16543 #ifdef INET
16544 	{
16545 		error = ip_output(m, NULL,
16546 				  &inp->inp_route,
16547 				  0, 0, inp);
16548 	}
16549 #endif
16550 	if (lgb) {
16551 		lgb->tlb_errno = error;
16552 		lgb = NULL;
16553 	}
16554 	if (error) {
16555 		*send_err = error;
16556 		m = NULL;
16557 		goto failed;
16558 	}
16559 	rack_log_output(tp, &to, len, tp->snd_max, flags, error, rack_to_usec_ts(tv),
16560 			NULL, add_flag, s_mb, s_soff, rack->r_ctl.fsb.hw_tls);
16561 	m = NULL;
16562 	if (tp->snd_una == tp->snd_max) {
16563 		rack->r_ctl.rc_tlp_rxt_last_time = cts;
16564 		rack_log_progress_event(rack, tp, ticks, PROGRESS_START, __LINE__);
16565 		tp->t_acktime = ticks;
16566 	}
16567 	if (error == 0)
16568 		tcp_account_for_send(tp, len, 0, 0, rack->r_ctl.fsb.hw_tls);
16569 
16570 	rack->forced_ack = 0;	/* If we send something zap the FA flag */
16571 	tot_len += len;
16572 	if ((tp->t_flags & TF_GPUTINPROG) == 0)
16573 		rack_start_gp_measurement(tp, rack, tp->snd_max, sb_offset);
16574 	tp->snd_max += len;
16575 	tp->snd_nxt = tp->snd_max;
16576 	{
16577 		int idx;
16578 
16579 		idx = (len / segsiz) + 3;
16580 		if (idx >= TCP_MSS_ACCT_ATIMER)
16581 			counter_u64_add(rack_out_size[(TCP_MSS_ACCT_ATIMER-1)], 1);
16582 		else
16583 			counter_u64_add(rack_out_size[idx], 1);
16584 	}
16585 	if (len <= rack->r_ctl.fsb.left_to_send)
16586 		rack->r_ctl.fsb.left_to_send -= len;
16587 	else
16588 		rack->r_ctl.fsb.left_to_send = 0;
16589 	if (rack->r_ctl.fsb.left_to_send < segsiz) {
16590 		rack->r_fast_output = 0;
16591 		rack->r_ctl.fsb.left_to_send = 0;
16592 		/* At the end of fast_output scale up the sb */
16593 		SOCKBUF_LOCK(&rack->rc_inp->inp_socket->so_snd);
16594 		rack_sndbuf_autoscale(rack);
16595 		SOCKBUF_UNLOCK(&rack->rc_inp->inp_socket->so_snd);
16596 	}
16597 	if (tp->t_rtttime == 0) {
16598 		tp->t_rtttime = ticks;
16599 		tp->t_rtseq = startseq;
16600 		KMOD_TCPSTAT_INC(tcps_segstimed);
16601 	}
16602 	if ((rack->r_ctl.fsb.left_to_send >= segsiz) &&
16603 	    (max_val > len) &&
16604 	    (tso == 0)) {
16605 		max_val -= len;
16606 		len = segsiz;
16607 		th = rack->r_ctl.fsb.th;
16608 		cnt_thru++;
16609 		goto again;
16610 	}
16611 	tp->t_flags &= ~(TF_ACKNOW | TF_DELACK);
16612 	counter_u64_add(rack_fto_send, 1);
16613 	slot = rack_get_pacing_delay(rack, tp, tot_len, NULL, segsiz);
16614 	rack_start_hpts_timer(rack, tp, cts, slot, tot_len, 0);
16615 #ifdef TCP_ACCOUNTING
16616 	crtsc = get_cyclecount();
16617 	if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
16618 		tp->tcp_cnt_counters[SND_OUT_DATA] += cnt_thru;
16619 	}
16620 	counter_u64_add(tcp_cnt_counters[SND_OUT_DATA], cnt_thru);
16621 	if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
16622 		tp->tcp_proc_time[SND_OUT_DATA] += (crtsc - ts_val);
16623 	}
16624 	counter_u64_add(tcp_proc_time[SND_OUT_DATA], (crtsc - ts_val));
16625 	if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
16626 		tp->tcp_cnt_counters[CNT_OF_MSS_OUT] += ((tot_len + segsiz - 1) / segsiz);
16627 	}
16628 	counter_u64_add(tcp_cnt_counters[CNT_OF_MSS_OUT], ((tot_len + segsiz - 1) / segsiz));
16629 	sched_unpin();
16630 #endif
16631 	return (0);
16632 failed:
16633 	if (m)
16634 		m_free(m);
16635 	rack->r_fast_output = 0;
16636 	return (-1);
16637 }
16638 
16639 static int
16640 rack_output(struct tcpcb *tp)
16641 {
16642 	struct socket *so;
16643 	uint32_t recwin;
16644 	uint32_t sb_offset, s_moff = 0;
16645 	int32_t len, flags, error = 0;
16646 	struct mbuf *m, *s_mb = NULL;
16647 	struct mbuf *mb;
16648 	uint32_t if_hw_tsomaxsegcount = 0;
16649 	uint32_t if_hw_tsomaxsegsize;
16650 	int32_t segsiz, minseg;
16651 	long tot_len_this_send = 0;
16652 #ifdef INET
16653 	struct ip *ip = NULL;
16654 #endif
16655 #ifdef TCPDEBUG
16656 	struct ipovly *ipov = NULL;
16657 #endif
16658 	struct udphdr *udp = NULL;
16659 	struct tcp_rack *rack;
16660 	struct tcphdr *th;
16661 	uint8_t pass = 0;
16662 	uint8_t mark = 0;
16663 	uint8_t wanted_cookie = 0;
16664 	u_char opt[TCP_MAXOLEN];
16665 	unsigned ipoptlen, optlen, hdrlen, ulen=0;
16666 	uint32_t rack_seq;
16667 
16668 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
16669 	unsigned ipsec_optlen = 0;
16670 
16671 #endif
16672 	int32_t idle, sendalot;
16673 	int32_t sub_from_prr = 0;
16674 	volatile int32_t sack_rxmit;
16675 	struct rack_sendmap *rsm = NULL;
16676 	int32_t tso, mtu;
16677 	struct tcpopt to;
16678 	int32_t slot = 0;
16679 	int32_t sup_rack = 0;
16680 	uint32_t cts, ms_cts, delayed, early;
16681 	uint16_t add_flag = RACK_SENT_SP;
16682 	/* The doing_tlp flag will be set by the actual rack_timeout_tlp() */
16683 	uint8_t hpts_calling,  doing_tlp = 0;
16684 	uint32_t cwnd_to_use, pace_max_seg;
16685 	int32_t do_a_prefetch = 0;
16686 	int32_t prefetch_rsm = 0;
16687 	int32_t orig_len = 0;
16688 	struct timeval tv;
16689 	int32_t prefetch_so_done = 0;
16690 	struct tcp_log_buffer *lgb;
16691 	struct inpcb *inp;
16692 	struct sockbuf *sb;
16693 	uint64_t ts_val = 0;
16694 #ifdef TCP_ACCOUNTING
16695 	uint64_t crtsc;
16696 #endif
16697 #ifdef INET6
16698 	struct ip6_hdr *ip6 = NULL;
16699 	int32_t isipv6;
16700 #endif
16701 	uint8_t filled_all = 0;
16702 	bool hw_tls = false;
16703 
16704 	/* setup and take the cache hits here */
16705 	rack = (struct tcp_rack *)tp->t_fb_ptr;
16706 #ifdef TCP_ACCOUNTING
16707 	sched_pin();
16708 	ts_val = get_cyclecount();
16709 #endif
16710 	hpts_calling = rack->rc_inp->inp_hpts_calls;
16711 	NET_EPOCH_ASSERT();
16712 	INP_WLOCK_ASSERT(rack->rc_inp);
16713 #ifdef TCP_OFFLOAD
16714 	if (tp->t_flags & TF_TOE) {
16715 #ifdef TCP_ACCOUNTING
16716 		sched_unpin();
16717 #endif
16718 		return (tcp_offload_output(tp));
16719 	}
16720 #endif
16721 	/*
16722 	 * For TFO connections in SYN_RECEIVED, only allow the initial
16723 	 * SYN|ACK and those sent by the retransmit timer.
16724 	 */
16725 	if (IS_FASTOPEN(tp->t_flags) &&
16726 	    (tp->t_state == TCPS_SYN_RECEIVED) &&
16727 	    SEQ_GT(tp->snd_max, tp->snd_una) &&    /* initial SYN|ACK sent */
16728 	    (rack->r_ctl.rc_resend == NULL)) {         /* not a retransmit */
16729 #ifdef TCP_ACCOUNTING
16730 		sched_unpin();
16731 #endif
16732 		return (0);
16733 	}
16734 #ifdef INET6
16735 	if (rack->r_state) {
16736 		/* Use the cache line loaded if possible */
16737 		isipv6 = rack->r_is_v6;
16738 	} else {
16739 		isipv6 = (rack->rc_inp->inp_vflag & INP_IPV6) != 0;
16740 	}
16741 #endif
16742 	early = 0;
16743 	cts = tcp_get_usecs(&tv);
16744 	ms_cts = tcp_tv_to_mssectick(&tv);
16745 	if (((rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT) == 0) &&
16746 	    rack->rc_inp->inp_in_hpts) {
16747 		/*
16748 		 * We are on the hpts for some timer but not hptsi output.
16749 		 * Remove from the hpts unconditionally.
16750 		 */
16751 		rack_timer_cancel(tp, rack, cts, __LINE__);
16752 	}
16753 	/* Are we pacing and late? */
16754 	if ((rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT) &&
16755 	    TSTMP_GEQ(cts, rack->r_ctl.rc_last_output_to)) {
16756 		/* We are delayed */
16757 		delayed = cts - rack->r_ctl.rc_last_output_to;
16758 	} else {
16759 		delayed = 0;
16760 	}
16761 	/* Do the timers, which may override the pacer */
16762 	if (rack->r_ctl.rc_hpts_flags & PACE_TMR_MASK) {
16763 		if (rack_process_timers(tp, rack, cts, hpts_calling, &doing_tlp)) {
16764 			counter_u64_add(rack_out_size[TCP_MSS_ACCT_ATIMER], 1);
16765 #ifdef TCP_ACCOUNTING
16766 			sched_unpin();
16767 #endif
16768 			return (0);
16769 		}
16770 	}
16771 	if (rack->rc_in_persist) {
16772 		if (rack->rc_inp->inp_in_hpts == 0) {
16773 			/* Timer is not running */
16774 			rack_start_hpts_timer(rack, tp, cts, 0, 0, 0);
16775 		}
16776 #ifdef TCP_ACCOUNTING
16777 		sched_unpin();
16778 #endif
16779 		return (0);
16780 	}
16781 	if ((rack->r_timer_override) ||
16782 	    (rack->rc_ack_can_sendout_data) ||
16783 	    (delayed) ||
16784 	    (tp->t_state < TCPS_ESTABLISHED)) {
16785 		rack->rc_ack_can_sendout_data = 0;
16786 		if (rack->rc_inp->inp_in_hpts)
16787 			tcp_hpts_remove(rack->rc_inp, HPTS_REMOVE_OUTPUT);
16788 	} else if (rack->rc_inp->inp_in_hpts) {
16789 		/*
16790 		 * On the hpts you can't pass even if ACKNOW is on, we will
16791 		 * when the hpts fires.
16792 		 */
16793 #ifdef TCP_ACCOUNTING
16794 		crtsc = get_cyclecount();
16795 		if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
16796 			tp->tcp_proc_time[SND_BLOCKED] += (crtsc - ts_val);
16797 		}
16798 		counter_u64_add(tcp_proc_time[SND_BLOCKED], (crtsc - ts_val));
16799 		if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
16800 			tp->tcp_cnt_counters[SND_BLOCKED]++;
16801 		}
16802 		counter_u64_add(tcp_cnt_counters[SND_BLOCKED], 1);
16803 		sched_unpin();
16804 #endif
16805 		counter_u64_add(rack_out_size[TCP_MSS_ACCT_INPACE], 1);
16806 		return (0);
16807 	}
16808 	rack->rc_inp->inp_hpts_calls = 0;
16809 	/* Finish out both pacing early and late accounting */
16810 	if ((rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT) &&
16811 	    TSTMP_GT(rack->r_ctl.rc_last_output_to, cts)) {
16812 		early = rack->r_ctl.rc_last_output_to - cts;
16813 	} else
16814 		early = 0;
16815 	if (delayed) {
16816 		rack->r_ctl.rc_agg_delayed += delayed;
16817 		rack->r_late = 1;
16818 	} else if (early) {
16819 		rack->r_ctl.rc_agg_early += early;
16820 		rack->r_early = 1;
16821 	}
16822 	/* Now that early/late accounting is done turn off the flag */
16823 	rack->r_ctl.rc_hpts_flags &= ~PACE_PKT_OUTPUT;
16824 	rack->r_wanted_output = 0;
16825 	rack->r_timer_override = 0;
16826 	if ((tp->t_state != rack->r_state) &&
16827 	    TCPS_HAVEESTABLISHED(tp->t_state)) {
16828 		rack_set_state(tp, rack);
16829 	}
16830 	if ((rack->r_fast_output) &&
16831 	    (doing_tlp == 0) &&
16832 	    (tp->rcv_numsacks == 0)) {
16833 		int ret;
16834 
16835 		error = 0;
16836 		ret = rack_fast_output(tp, rack, ts_val, cts, ms_cts, &tv, tot_len_this_send, &error);
16837 		if (ret >= 0)
16838 			return(ret);
16839 		else if (error) {
16840 			inp = rack->rc_inp;
16841 			so = inp->inp_socket;
16842 			sb = &so->so_snd;
16843 			goto nomore;
16844 		}
16845 	}
16846 	inp = rack->rc_inp;
16847 	/*
16848 	 * For TFO connections in SYN_SENT or SYN_RECEIVED,
16849 	 * only allow the initial SYN or SYN|ACK and those sent
16850 	 * by the retransmit timer.
16851 	 */
16852 	if (IS_FASTOPEN(tp->t_flags) &&
16853 	    ((tp->t_state == TCPS_SYN_RECEIVED) ||
16854 	     (tp->t_state == TCPS_SYN_SENT)) &&
16855 	    SEQ_GT(tp->snd_max, tp->snd_una) && /* initial SYN or SYN|ACK sent */
16856 	    (tp->t_rxtshift == 0)) {              /* not a retransmit */
16857 		cwnd_to_use = rack->r_ctl.cwnd_to_use = tp->snd_cwnd;
16858 		so = inp->inp_socket;
16859 		sb = &so->so_snd;
16860 		goto just_return_nolock;
16861 	}
16862 	/*
16863 	 * Determine length of data that should be transmitted, and flags
16864 	 * that will be used. If there is some data or critical controls
16865 	 * (SYN, RST) to send, then transmit; otherwise, investigate
16866 	 * further.
16867 	 */
16868 	idle = (tp->t_flags & TF_LASTIDLE) || (tp->snd_max == tp->snd_una);
16869 	if (tp->t_idle_reduce) {
16870 		if (idle && ((ticks - tp->t_rcvtime) >= tp->t_rxtcur))
16871 			rack_cc_after_idle(rack, tp);
16872 	}
16873 	tp->t_flags &= ~TF_LASTIDLE;
16874 	if (idle) {
16875 		if (tp->t_flags & TF_MORETOCOME) {
16876 			tp->t_flags |= TF_LASTIDLE;
16877 			idle = 0;
16878 		}
16879 	}
16880 	if ((tp->snd_una == tp->snd_max) &&
16881 	    rack->r_ctl.rc_went_idle_time &&
16882 	    TSTMP_GT(cts, rack->r_ctl.rc_went_idle_time)) {
16883 		idle = cts - rack->r_ctl.rc_went_idle_time;
16884 		if (idle > rack_min_probertt_hold) {
16885 			/* Count as a probe rtt */
16886 			if (rack->in_probe_rtt == 0) {
16887 				rack->r_ctl.rc_lower_rtt_us_cts = cts;
16888 				rack->r_ctl.rc_time_probertt_entered = rack->r_ctl.rc_lower_rtt_us_cts;
16889 				rack->r_ctl.rc_time_probertt_starts = rack->r_ctl.rc_lower_rtt_us_cts;
16890 				rack->r_ctl.rc_time_of_last_probertt = rack->r_ctl.rc_lower_rtt_us_cts;
16891 			} else {
16892 				rack_exit_probertt(rack, cts);
16893 			}
16894 		}
16895 		idle = 0;
16896 	}
16897 	if (rack_use_fsb && (rack->r_fsb_inited == 0) && (rack->r_state != TCPS_CLOSED))
16898 		rack_init_fsb_block(tp, rack);
16899 again:
16900 	/*
16901 	 * If we've recently taken a timeout, snd_max will be greater than
16902 	 * snd_nxt.  There may be SACK information that allows us to avoid
16903 	 * resending already delivered data.  Adjust snd_nxt accordingly.
16904 	 */
16905 	sendalot = 0;
16906 	cts = tcp_get_usecs(&tv);
16907 	ms_cts = tcp_tv_to_mssectick(&tv);
16908 	tso = 0;
16909 	mtu = 0;
16910 	segsiz = min(ctf_fixed_maxseg(tp), rack->r_ctl.rc_pace_min_segs);
16911 	minseg = segsiz;
16912 	if (rack->r_ctl.rc_pace_max_segs == 0)
16913 		pace_max_seg = rack->rc_user_set_max_segs * segsiz;
16914 	else
16915 		pace_max_seg = rack->r_ctl.rc_pace_max_segs;
16916 	sb_offset = tp->snd_max - tp->snd_una;
16917 	cwnd_to_use = rack->r_ctl.cwnd_to_use = tp->snd_cwnd;
16918 	flags = tcp_outflags[tp->t_state];
16919 	while (rack->rc_free_cnt < rack_free_cache) {
16920 		rsm = rack_alloc(rack);
16921 		if (rsm == NULL) {
16922 			if (inp->inp_hpts_calls)
16923 				/* Retry in a ms */
16924 				slot = (1 * HPTS_USEC_IN_MSEC);
16925 			so = inp->inp_socket;
16926 			sb = &so->so_snd;
16927 			goto just_return_nolock;
16928 		}
16929 		TAILQ_INSERT_TAIL(&rack->r_ctl.rc_free, rsm, r_tnext);
16930 		rack->rc_free_cnt++;
16931 		rsm = NULL;
16932 	}
16933 	if (inp->inp_hpts_calls)
16934 		inp->inp_hpts_calls = 0;
16935 	sack_rxmit = 0;
16936 	len = 0;
16937 	rsm = NULL;
16938 	if (flags & TH_RST) {
16939 		SOCKBUF_LOCK(&inp->inp_socket->so_snd);
16940 		so = inp->inp_socket;
16941 		sb = &so->so_snd;
16942 		goto send;
16943 	}
16944 	if (rack->r_ctl.rc_resend) {
16945 		/* Retransmit timer */
16946 		rsm = rack->r_ctl.rc_resend;
16947 		rack->r_ctl.rc_resend = NULL;
16948 		len = rsm->r_end - rsm->r_start;
16949 		sack_rxmit = 1;
16950 		sendalot = 0;
16951 		KASSERT(SEQ_LEQ(tp->snd_una, rsm->r_start),
16952 			("%s:%d: r.start:%u < SND.UNA:%u; tp:%p, rack:%p, rsm:%p",
16953 			 __func__, __LINE__,
16954 			 rsm->r_start, tp->snd_una, tp, rack, rsm));
16955 		sb_offset = rsm->r_start - tp->snd_una;
16956 		if (len >= segsiz)
16957 			len = segsiz;
16958 	} else if ((rsm = tcp_rack_output(tp, rack, cts)) != NULL) {
16959 		/* We have a retransmit that takes precedence */
16960 		if ((!IN_FASTRECOVERY(tp->t_flags)) &&
16961 		    ((tp->t_flags & TF_WASFRECOVERY) == 0)) {
16962 			/* Enter recovery if not induced by a time-out */
16963 			rack->r_ctl.rc_rsm_start = rsm->r_start;
16964 			rack->r_ctl.rc_cwnd_at = tp->snd_cwnd;
16965 			rack->r_ctl.rc_ssthresh_at = tp->snd_ssthresh;
16966 			rack_cong_signal(tp, CC_NDUPACK, tp->snd_una);
16967 		}
16968 #ifdef INVARIANTS
16969 		if (SEQ_LT(rsm->r_start, tp->snd_una)) {
16970 			panic("Huh, tp:%p rack:%p rsm:%p start:%u < snd_una:%u\n",
16971 			      tp, rack, rsm, rsm->r_start, tp->snd_una);
16972 		}
16973 #endif
16974 		len = rsm->r_end - rsm->r_start;
16975 		KASSERT(SEQ_LEQ(tp->snd_una, rsm->r_start),
16976 			("%s:%d: r.start:%u < SND.UNA:%u; tp:%p, rack:%p, rsm:%p",
16977 			 __func__, __LINE__,
16978 			 rsm->r_start, tp->snd_una, tp, rack, rsm));
16979 		sb_offset = rsm->r_start - tp->snd_una;
16980 		sendalot = 0;
16981 		if (len >= segsiz)
16982 			len = segsiz;
16983 		if (len > 0) {
16984 			sack_rxmit = 1;
16985 			KMOD_TCPSTAT_INC(tcps_sack_rexmits);
16986 			KMOD_TCPSTAT_ADD(tcps_sack_rexmit_bytes,
16987 			    min(len, segsiz));
16988 			counter_u64_add(rack_rtm_prr_retran, 1);
16989 		}
16990 	} else if (rack->r_ctl.rc_tlpsend) {
16991 		/* Tail loss probe */
16992 		long cwin;
16993 		long tlen;
16994 
16995 		/*
16996 		 * Check if we can do a TLP with a RACK'd packet
16997 		 * this can happen if we are not doing the rack
16998 		 * cheat and we skipped to a TLP and it
16999 		 * went off.
17000 		 */
17001 		rsm = rack->r_ctl.rc_tlpsend;
17002 		/* We are doing a TLP make sure the flag is preent */
17003 		rsm->r_flags |= RACK_TLP;
17004 		rack->r_ctl.rc_tlpsend = NULL;
17005 		sack_rxmit = 1;
17006 		tlen = rsm->r_end - rsm->r_start;
17007 		if (tlen > segsiz)
17008 			tlen = segsiz;
17009 		KASSERT(SEQ_LEQ(tp->snd_una, rsm->r_start),
17010 			("%s:%d: r.start:%u < SND.UNA:%u; tp:%p, rack:%p, rsm:%p",
17011 			 __func__, __LINE__,
17012 			 rsm->r_start, tp->snd_una, tp, rack, rsm));
17013 		sb_offset = rsm->r_start - tp->snd_una;
17014 		cwin = min(tp->snd_wnd, tlen);
17015 		len = cwin;
17016 	}
17017 	if (rack->r_must_retran &&
17018 	    (rsm == NULL)) {
17019 		/*
17020 		 * Non-Sack and we had a RTO or Sack/non-Sack and a
17021 		 * MTU change, we need to retransmit until we reach
17022 		 * the former snd_max (rack->r_ctl.rc_snd_max_at_rto).
17023 		 */
17024 		if (SEQ_GT(tp->snd_max, tp->snd_una)) {
17025 			int sendwin, flight;
17026 
17027 			sendwin = min(tp->snd_wnd, tp->snd_cwnd);
17028 			flight = ctf_flight_size(tp, rack->r_ctl.rc_out_at_rto);
17029 			if (flight >= sendwin) {
17030 				so = inp->inp_socket;
17031 				sb = &so->so_snd;
17032 				goto just_return_nolock;
17033 			}
17034 			rsm = TAILQ_FIRST(&rack->r_ctl.rc_tmap);
17035 			if (rsm == NULL) {
17036 				/* TSNH */
17037 				rack->r_must_retran = 0;
17038 				rack->r_ctl.rc_out_at_rto = 0;
17039 				rack->r_must_retran = 0;
17040 				so = inp->inp_socket;
17041 				sb = &so->so_snd;
17042 				goto just_return_nolock;
17043 			}
17044 			if ((rsm->r_flags & RACK_MUST_RXT) == 0) {
17045 				/* It does not have the flag, we are done */
17046 				rack->r_must_retran = 0;
17047 				rack->r_ctl.rc_out_at_rto = 0;
17048 			} else {
17049 				sack_rxmit = 1;
17050 				len = rsm->r_end - rsm->r_start;
17051 				sendalot = 0;
17052 				sb_offset = rsm->r_start - tp->snd_una;
17053 				if (len >= segsiz)
17054 					len = segsiz;
17055 				/*
17056 				 * Delay removing the flag RACK_MUST_RXT so
17057 				 * that the fastpath for retransmit will
17058 				 * work with this rsm.
17059 				 */
17060 
17061 			}
17062 		} else {
17063 			/* We must be done if there is nothing outstanding */
17064 			rack->r_must_retran = 0;
17065 			rack->r_ctl.rc_out_at_rto = 0;
17066 		}
17067 	}
17068 	/*
17069 	 * Enforce a connection sendmap count limit if set
17070 	 * as long as we are not retransmiting.
17071 	 */
17072 	if ((rsm == NULL) &&
17073 	    (rack->do_detection == 0) &&
17074 	    (V_tcp_map_entries_limit > 0) &&
17075 	    (rack->r_ctl.rc_num_maps_alloced >= V_tcp_map_entries_limit)) {
17076 		counter_u64_add(rack_to_alloc_limited, 1);
17077 		if (!rack->alloc_limit_reported) {
17078 			rack->alloc_limit_reported = 1;
17079 			counter_u64_add(rack_alloc_limited_conns, 1);
17080 		}
17081 		so = inp->inp_socket;
17082 		sb = &so->so_snd;
17083 		goto just_return_nolock;
17084 	}
17085 	if (rsm && (rsm->r_flags & RACK_HAS_FIN)) {
17086 		/* we are retransmitting the fin */
17087 		len--;
17088 		if (len) {
17089 			/*
17090 			 * When retransmitting data do *not* include the
17091 			 * FIN. This could happen from a TLP probe.
17092 			 */
17093 			flags &= ~TH_FIN;
17094 		}
17095 	}
17096 #ifdef INVARIANTS
17097 	/* For debugging */
17098 	rack->r_ctl.rc_rsm_at_retran = rsm;
17099 #endif
17100 	if (rsm && rack->r_fsb_inited && rack_use_rsm_rfo &&
17101 	    ((rsm->r_flags & RACK_HAS_FIN) == 0)) {
17102 		int ret;
17103 
17104 		ret = rack_fast_rsm_output(tp, rack, rsm, ts_val, cts, ms_cts, &tv, len, doing_tlp);
17105 		if (ret == 0)
17106 			return (0);
17107 	}
17108 	if (rsm && (rsm->r_flags & RACK_MUST_RXT)) {
17109 		/*
17110 		 * Clear the flag in prep for the send
17111 		 * note that if we can't get an mbuf
17112 		 * and fail, we won't retransmit this
17113 		 * rsm but that should be ok (its rare).
17114 		 */
17115 		rsm->r_flags &= ~RACK_MUST_RXT;
17116 	}
17117 	so = inp->inp_socket;
17118 	sb = &so->so_snd;
17119 	if (do_a_prefetch == 0) {
17120 		kern_prefetch(sb, &do_a_prefetch);
17121 		do_a_prefetch = 1;
17122 	}
17123 #ifdef NETFLIX_SHARED_CWND
17124 	if ((tp->t_flags2 & TF2_TCP_SCWND_ALLOWED) &&
17125 	    rack->rack_enable_scwnd) {
17126 		/* We are doing cwnd sharing */
17127 		if (rack->gp_ready &&
17128 		    (rack->rack_attempted_scwnd == 0) &&
17129 		    (rack->r_ctl.rc_scw == NULL) &&
17130 		    tp->t_lib) {
17131 			/* The pcbid is in, lets make an attempt */
17132 			counter_u64_add(rack_try_scwnd, 1);
17133 			rack->rack_attempted_scwnd = 1;
17134 			rack->r_ctl.rc_scw = tcp_shared_cwnd_alloc(tp,
17135 								   &rack->r_ctl.rc_scw_index,
17136 								   segsiz);
17137 		}
17138 		if (rack->r_ctl.rc_scw &&
17139 		    (rack->rack_scwnd_is_idle == 1) &&
17140 		    sbavail(&so->so_snd)) {
17141 			/* we are no longer out of data */
17142 			tcp_shared_cwnd_active(rack->r_ctl.rc_scw, rack->r_ctl.rc_scw_index);
17143 			rack->rack_scwnd_is_idle = 0;
17144 		}
17145 		if (rack->r_ctl.rc_scw) {
17146 			/* First lets update and get the cwnd */
17147 			rack->r_ctl.cwnd_to_use = cwnd_to_use = tcp_shared_cwnd_update(rack->r_ctl.rc_scw,
17148 								    rack->r_ctl.rc_scw_index,
17149 								    tp->snd_cwnd, tp->snd_wnd, segsiz);
17150 		}
17151 	}
17152 #endif
17153 	/*
17154 	 * Get standard flags, and add SYN or FIN if requested by 'hidden'
17155 	 * state flags.
17156 	 */
17157 	if (tp->t_flags & TF_NEEDFIN)
17158 		flags |= TH_FIN;
17159 	if (tp->t_flags & TF_NEEDSYN)
17160 		flags |= TH_SYN;
17161 	if ((sack_rxmit == 0) && (prefetch_rsm == 0)) {
17162 		void *end_rsm;
17163 		end_rsm = TAILQ_LAST_FAST(&rack->r_ctl.rc_tmap, rack_sendmap, r_tnext);
17164 		if (end_rsm)
17165 			kern_prefetch(end_rsm, &prefetch_rsm);
17166 		prefetch_rsm = 1;
17167 	}
17168 	SOCKBUF_LOCK(sb);
17169 	/*
17170 	 * If snd_nxt == snd_max and we have transmitted a FIN, the
17171 	 * sb_offset will be > 0 even if so_snd.sb_cc is 0, resulting in a
17172 	 * negative length.  This can also occur when TCP opens up its
17173 	 * congestion window while receiving additional duplicate acks after
17174 	 * fast-retransmit because TCP will reset snd_nxt to snd_max after
17175 	 * the fast-retransmit.
17176 	 *
17177 	 * In the normal retransmit-FIN-only case, however, snd_nxt will be
17178 	 * set to snd_una, the sb_offset will be 0, and the length may wind
17179 	 * up 0.
17180 	 *
17181 	 * If sack_rxmit is true we are retransmitting from the scoreboard
17182 	 * in which case len is already set.
17183 	 */
17184 	if ((sack_rxmit == 0) &&
17185 	    (TCPS_HAVEESTABLISHED(tp->t_state) || IS_FASTOPEN(tp->t_flags))) {
17186 		uint32_t avail;
17187 
17188 		avail = sbavail(sb);
17189 		if (SEQ_GT(tp->snd_nxt, tp->snd_una) && avail)
17190 			sb_offset = tp->snd_nxt - tp->snd_una;
17191 		else
17192 			sb_offset = 0;
17193 		if ((IN_FASTRECOVERY(tp->t_flags) == 0) || rack->rack_no_prr) {
17194 			if (rack->r_ctl.rc_tlp_new_data) {
17195 				/* TLP is forcing out new data */
17196 				if (rack->r_ctl.rc_tlp_new_data > (uint32_t) (avail - sb_offset)) {
17197 					rack->r_ctl.rc_tlp_new_data = (uint32_t) (avail - sb_offset);
17198 				}
17199 				if ((rack->r_ctl.rc_tlp_new_data + sb_offset) > tp->snd_wnd) {
17200 					if (tp->snd_wnd > sb_offset)
17201 						len = tp->snd_wnd - sb_offset;
17202 					else
17203 						len = 0;
17204 				} else {
17205 					len = rack->r_ctl.rc_tlp_new_data;
17206 				}
17207 			}  else {
17208 				len = rack_what_can_we_send(tp, rack, cwnd_to_use, avail, sb_offset);
17209 			}
17210 			if ((rack->r_ctl.crte == NULL) && IN_FASTRECOVERY(tp->t_flags) && (len > segsiz)) {
17211 				/*
17212 				 * For prr=off, we need to send only 1 MSS
17213 				 * at a time. We do this because another sack could
17214 				 * be arriving that causes us to send retransmits and
17215 				 * we don't want to be on a long pace due to a larger send
17216 				 * that keeps us from sending out the retransmit.
17217 				 */
17218 				len = segsiz;
17219 			}
17220 		} else {
17221 			uint32_t outstanding;
17222 			/*
17223 			 * We are inside of a Fast recovery episode, this
17224 			 * is caused by a SACK or 3 dup acks. At this point
17225 			 * we have sent all the retransmissions and we rely
17226 			 * on PRR to dictate what we will send in the form of
17227 			 * new data.
17228 			 */
17229 
17230 			outstanding = tp->snd_max - tp->snd_una;
17231 			if ((rack->r_ctl.rc_prr_sndcnt + outstanding) > tp->snd_wnd) {
17232 				if (tp->snd_wnd > outstanding) {
17233 					len = tp->snd_wnd - outstanding;
17234 					/* Check to see if we have the data */
17235 					if ((sb_offset + len) > avail) {
17236 						/* It does not all fit */
17237 						if (avail > sb_offset)
17238 							len = avail - sb_offset;
17239 						else
17240 							len = 0;
17241 					}
17242 				} else {
17243 					len = 0;
17244 				}
17245 			} else if (avail > sb_offset) {
17246 				len = avail - sb_offset;
17247 			} else {
17248 				len = 0;
17249 			}
17250 			if (len > 0) {
17251 				if (len > rack->r_ctl.rc_prr_sndcnt) {
17252 					len = rack->r_ctl.rc_prr_sndcnt;
17253 				}
17254 				if (len > 0) {
17255 					sub_from_prr = 1;
17256 					counter_u64_add(rack_rtm_prr_newdata, 1);
17257 				}
17258 			}
17259 			if (len > segsiz) {
17260 				/*
17261 				 * We should never send more than a MSS when
17262 				 * retransmitting or sending new data in prr
17263 				 * mode unless the override flag is on. Most
17264 				 * likely the PRR algorithm is not going to
17265 				 * let us send a lot as well :-)
17266 				 */
17267 				if (rack->r_ctl.rc_prr_sendalot == 0) {
17268 					len = segsiz;
17269 				}
17270 			} else if (len < segsiz) {
17271 				/*
17272 				 * Do we send any? The idea here is if the
17273 				 * send empty's the socket buffer we want to
17274 				 * do it. However if not then lets just wait
17275 				 * for our prr_sndcnt to get bigger.
17276 				 */
17277 				long leftinsb;
17278 
17279 				leftinsb = sbavail(sb) - sb_offset;
17280 				if (leftinsb > len) {
17281 					/* This send does not empty the sb */
17282 					len = 0;
17283 				}
17284 			}
17285 		}
17286 	} else if (!TCPS_HAVEESTABLISHED(tp->t_state)) {
17287 		/*
17288 		 * If you have not established
17289 		 * and are not doing FAST OPEN
17290 		 * no data please.
17291 		 */
17292 		if ((sack_rxmit == 0) &&
17293 		    (!IS_FASTOPEN(tp->t_flags))){
17294 			len = 0;
17295 			sb_offset = 0;
17296 		}
17297 	}
17298 	if (prefetch_so_done == 0) {
17299 		kern_prefetch(so, &prefetch_so_done);
17300 		prefetch_so_done = 1;
17301 	}
17302 	/*
17303 	 * Lop off SYN bit if it has already been sent.  However, if this is
17304 	 * SYN-SENT state and if segment contains data and if we don't know
17305 	 * that foreign host supports TAO, suppress sending segment.
17306 	 */
17307 	if ((flags & TH_SYN) && SEQ_GT(tp->snd_nxt, tp->snd_una) &&
17308 	    ((sack_rxmit == 0) && (tp->t_rxtshift == 0))) {
17309 		/*
17310 		 * When sending additional segments following a TFO SYN|ACK,
17311 		 * do not include the SYN bit.
17312 		 */
17313 		if (IS_FASTOPEN(tp->t_flags) &&
17314 		    (tp->t_state == TCPS_SYN_RECEIVED))
17315 			flags &= ~TH_SYN;
17316 	}
17317 	/*
17318 	 * Be careful not to send data and/or FIN on SYN segments. This
17319 	 * measure is needed to prevent interoperability problems with not
17320 	 * fully conformant TCP implementations.
17321 	 */
17322 	if ((flags & TH_SYN) && (tp->t_flags & TF_NOOPT)) {
17323 		len = 0;
17324 		flags &= ~TH_FIN;
17325 	}
17326 	/*
17327 	 * On TFO sockets, ensure no data is sent in the following cases:
17328 	 *
17329 	 *  - When retransmitting SYN|ACK on a passively-created socket
17330 	 *
17331 	 *  - When retransmitting SYN on an actively created socket
17332 	 *
17333 	 *  - When sending a zero-length cookie (cookie request) on an
17334 	 *    actively created socket
17335 	 *
17336 	 *  - When the socket is in the CLOSED state (RST is being sent)
17337 	 */
17338 	if (IS_FASTOPEN(tp->t_flags) &&
17339 	    (((flags & TH_SYN) && (tp->t_rxtshift > 0)) ||
17340 	     ((tp->t_state == TCPS_SYN_SENT) &&
17341 	      (tp->t_tfo_client_cookie_len == 0)) ||
17342 	     (flags & TH_RST))) {
17343 		sack_rxmit = 0;
17344 		len = 0;
17345 	}
17346 	/* Without fast-open there should never be data sent on a SYN */
17347 	if ((flags & TH_SYN) && (!IS_FASTOPEN(tp->t_flags))) {
17348 		tp->snd_nxt = tp->iss;
17349 		len = 0;
17350 	}
17351 	if ((len > segsiz) && (tcp_dsack_block_exists(tp))) {
17352 		/* We only send 1 MSS if we have a DSACK block */
17353 		add_flag |= RACK_SENT_W_DSACK;
17354 		len = segsiz;
17355 	}
17356 	orig_len = len;
17357 	if (len <= 0) {
17358 		/*
17359 		 * If FIN has been sent but not acked, but we haven't been
17360 		 * called to retransmit, len will be < 0.  Otherwise, window
17361 		 * shrank after we sent into it.  If window shrank to 0,
17362 		 * cancel pending retransmit, pull snd_nxt back to (closed)
17363 		 * window, and set the persist timer if it isn't already
17364 		 * going.  If the window didn't close completely, just wait
17365 		 * for an ACK.
17366 		 *
17367 		 * We also do a general check here to ensure that we will
17368 		 * set the persist timer when we have data to send, but a
17369 		 * 0-byte window. This makes sure the persist timer is set
17370 		 * even if the packet hits one of the "goto send" lines
17371 		 * below.
17372 		 */
17373 		len = 0;
17374 		if ((tp->snd_wnd == 0) &&
17375 		    (TCPS_HAVEESTABLISHED(tp->t_state)) &&
17376 		    (tp->snd_una == tp->snd_max) &&
17377 		    (sb_offset < (int)sbavail(sb))) {
17378 			rack_enter_persist(tp, rack, cts);
17379 		}
17380 	} else if ((rsm == NULL) &&
17381 		   (doing_tlp == 0) &&
17382 		   (len < pace_max_seg)) {
17383 		/*
17384 		 * We are not sending a maximum sized segment for
17385 		 * some reason. Should we not send anything (think
17386 		 * sws or persists)?
17387 		 */
17388 		if ((tp->snd_wnd < min((rack->r_ctl.rc_high_rwnd/2), minseg)) &&
17389 		    (TCPS_HAVEESTABLISHED(tp->t_state)) &&
17390 		    (len < minseg) &&
17391 		    (len < (int)(sbavail(sb) - sb_offset))) {
17392 			/*
17393 			 * Here the rwnd is less than
17394 			 * the minimum pacing size, this is not a retransmit,
17395 			 * we are established and
17396 			 * the send is not the last in the socket buffer
17397 			 * we send nothing, and we may enter persists
17398 			 * if nothing is outstanding.
17399 			 */
17400 			len = 0;
17401 			if (tp->snd_max == tp->snd_una) {
17402 				/*
17403 				 * Nothing out we can
17404 				 * go into persists.
17405 				 */
17406 				rack_enter_persist(tp, rack, cts);
17407 			}
17408 		     } else if ((cwnd_to_use >= max(minseg, (segsiz * 4))) &&
17409 			   (ctf_flight_size(tp, rack->r_ctl.rc_sacked) > (2 * segsiz)) &&
17410 			   (len < (int)(sbavail(sb) - sb_offset)) &&
17411 			   (len < minseg)) {
17412 			/*
17413 			 * Here we are not retransmitting, and
17414 			 * the cwnd is not so small that we could
17415 			 * not send at least a min size (rxt timer
17416 			 * not having gone off), We have 2 segments or
17417 			 * more already in flight, its not the tail end
17418 			 * of the socket buffer  and the cwnd is blocking
17419 			 * us from sending out a minimum pacing segment size.
17420 			 * Lets not send anything.
17421 			 */
17422 			len = 0;
17423 		} else if (((tp->snd_wnd - ctf_outstanding(tp)) <
17424 			    min((rack->r_ctl.rc_high_rwnd/2), minseg)) &&
17425 			   (ctf_flight_size(tp, rack->r_ctl.rc_sacked) > (2 * segsiz)) &&
17426 			   (len < (int)(sbavail(sb) - sb_offset)) &&
17427 			   (TCPS_HAVEESTABLISHED(tp->t_state))) {
17428 			/*
17429 			 * Here we have a send window but we have
17430 			 * filled it up and we can't send another pacing segment.
17431 			 * We also have in flight more than 2 segments
17432 			 * and we are not completing the sb i.e. we allow
17433 			 * the last bytes of the sb to go out even if
17434 			 * its not a full pacing segment.
17435 			 */
17436 			len = 0;
17437 		} else if ((rack->r_ctl.crte != NULL) &&
17438 			   (tp->snd_wnd >= (pace_max_seg * max(1, rack_hw_rwnd_factor))) &&
17439 			   (cwnd_to_use >= (pace_max_seg + (4 * segsiz))) &&
17440 			   (ctf_flight_size(tp, rack->r_ctl.rc_sacked) >= (2 * segsiz)) &&
17441 			   (len < (int)(sbavail(sb) - sb_offset))) {
17442 			/*
17443 			 * Here we are doing hardware pacing, this is not a TLP,
17444 			 * we are not sending a pace max segment size, there is rwnd
17445 			 * room to send at least N pace_max_seg, the cwnd is greater
17446 			 * than or equal to a full pacing segments plus 4 mss and we have 2 or
17447 			 * more segments in flight and its not the tail of the socket buffer.
17448 			 *
17449 			 * We don't want to send instead we need to get more ack's in to
17450 			 * allow us to send a full pacing segment. Normally, if we are pacing
17451 			 * about the right speed, we should have finished our pacing
17452 			 * send as most of the acks have come back if we are at the
17453 			 * right rate. This is a bit fuzzy since return path delay
17454 			 * can delay the acks, which is why we want to make sure we
17455 			 * have cwnd space to have a bit more than a max pace segments in flight.
17456 			 *
17457 			 * If we have not gotten our acks back we are pacing at too high a
17458 			 * rate delaying will not hurt and will bring our GP estimate down by
17459 			 * injecting the delay. If we don't do this we will send
17460 			 * 2 MSS out in response to the acks being clocked in which
17461 			 * defeats the point of hw-pacing (i.e. to help us get
17462 			 * larger TSO's out).
17463 			 */
17464 			len = 0;
17465 
17466 		}
17467 
17468 	}
17469 	/* len will be >= 0 after this point. */
17470 	KASSERT(len >= 0, ("[%s:%d]: len < 0", __func__, __LINE__));
17471 	rack_sndbuf_autoscale(rack);
17472 	/*
17473 	 * Decide if we can use TCP Segmentation Offloading (if supported by
17474 	 * hardware).
17475 	 *
17476 	 * TSO may only be used if we are in a pure bulk sending state.  The
17477 	 * presence of TCP-MD5, SACK retransmits, SACK advertizements and IP
17478 	 * options prevent using TSO.  With TSO the TCP header is the same
17479 	 * (except for the sequence number) for all generated packets.  This
17480 	 * makes it impossible to transmit any options which vary per
17481 	 * generated segment or packet.
17482 	 *
17483 	 * IPv4 handling has a clear separation of ip options and ip header
17484 	 * flags while IPv6 combines both in in6p_outputopts. ip6_optlen() does
17485 	 * the right thing below to provide length of just ip options and thus
17486 	 * checking for ipoptlen is enough to decide if ip options are present.
17487 	 */
17488 	ipoptlen = 0;
17489 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
17490 	/*
17491 	 * Pre-calculate here as we save another lookup into the darknesses
17492 	 * of IPsec that way and can actually decide if TSO is ok.
17493 	 */
17494 #ifdef INET6
17495 	if (isipv6 && IPSEC_ENABLED(ipv6))
17496 		ipsec_optlen = IPSEC_HDRSIZE(ipv6, tp->t_inpcb);
17497 #ifdef INET
17498 	else
17499 #endif
17500 #endif				/* INET6 */
17501 #ifdef INET
17502 		if (IPSEC_ENABLED(ipv4))
17503 			ipsec_optlen = IPSEC_HDRSIZE(ipv4, tp->t_inpcb);
17504 #endif				/* INET */
17505 #endif
17506 
17507 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
17508 	ipoptlen += ipsec_optlen;
17509 #endif
17510 	if ((tp->t_flags & TF_TSO) && V_tcp_do_tso && len > segsiz &&
17511 	    (tp->t_port == 0) &&
17512 	    ((tp->t_flags & TF_SIGNATURE) == 0) &&
17513 	    tp->rcv_numsacks == 0 && sack_rxmit == 0 &&
17514 	    ipoptlen == 0)
17515 		tso = 1;
17516 	{
17517 		uint32_t outstanding;
17518 
17519 		outstanding = tp->snd_max - tp->snd_una;
17520 		if (tp->t_flags & TF_SENTFIN) {
17521 			/*
17522 			 * If we sent a fin, snd_max is 1 higher than
17523 			 * snd_una
17524 			 */
17525 			outstanding--;
17526 		}
17527 		if (sack_rxmit) {
17528 			if ((rsm->r_flags & RACK_HAS_FIN) == 0)
17529 				flags &= ~TH_FIN;
17530 		} else {
17531 			if (SEQ_LT(tp->snd_nxt + len, tp->snd_una +
17532 				   sbused(sb)))
17533 				flags &= ~TH_FIN;
17534 		}
17535 	}
17536 	recwin = lmin(lmax(sbspace(&so->so_rcv), 0),
17537 	    (long)TCP_MAXWIN << tp->rcv_scale);
17538 
17539 	/*
17540 	 * Sender silly window avoidance.   We transmit under the following
17541 	 * conditions when len is non-zero:
17542 	 *
17543 	 * - We have a full segment (or more with TSO) - This is the last
17544 	 * buffer in a write()/send() and we are either idle or running
17545 	 * NODELAY - we've timed out (e.g. persist timer) - we have more
17546 	 * then 1/2 the maximum send window's worth of data (receiver may be
17547 	 * limited the window size) - we need to retransmit
17548 	 */
17549 	if (len) {
17550 		if (len >= segsiz) {
17551 			goto send;
17552 		}
17553 		/*
17554 		 * NOTE! on localhost connections an 'ack' from the remote
17555 		 * end may occur synchronously with the output and cause us
17556 		 * to flush a buffer queued with moretocome.  XXX
17557 		 *
17558 		 */
17559 		if (!(tp->t_flags & TF_MORETOCOME) &&	/* normal case */
17560 		    (idle || (tp->t_flags & TF_NODELAY)) &&
17561 		    ((uint32_t)len + (uint32_t)sb_offset >= sbavail(sb)) &&
17562 		    (tp->t_flags & TF_NOPUSH) == 0) {
17563 			pass = 2;
17564 			goto send;
17565 		}
17566 		if ((tp->snd_una == tp->snd_max) && len) {	/* Nothing outstanding */
17567 			pass = 22;
17568 			goto send;
17569 		}
17570 		if (len >= tp->max_sndwnd / 2 && tp->max_sndwnd > 0) {
17571 			pass = 4;
17572 			goto send;
17573 		}
17574 		if (SEQ_LT(tp->snd_nxt, tp->snd_max)) {	/* retransmit case */
17575 			pass = 5;
17576 			goto send;
17577 		}
17578 		if (sack_rxmit) {
17579 			pass = 6;
17580 			goto send;
17581 		}
17582 		if (((tp->snd_wnd - ctf_outstanding(tp)) < segsiz) &&
17583 		    (ctf_outstanding(tp) < (segsiz * 2))) {
17584 			/*
17585 			 * We have less than two MSS outstanding (delayed ack)
17586 			 * and our rwnd will not let us send a full sized
17587 			 * MSS. Lets go ahead and let this small segment
17588 			 * out because we want to try to have at least two
17589 			 * packets inflight to not be caught by delayed ack.
17590 			 */
17591 			pass = 12;
17592 			goto send;
17593 		}
17594 	}
17595 	/*
17596 	 * Sending of standalone window updates.
17597 	 *
17598 	 * Window updates are important when we close our window due to a
17599 	 * full socket buffer and are opening it again after the application
17600 	 * reads data from it.  Once the window has opened again and the
17601 	 * remote end starts to send again the ACK clock takes over and
17602 	 * provides the most current window information.
17603 	 *
17604 	 * We must avoid the silly window syndrome whereas every read from
17605 	 * the receive buffer, no matter how small, causes a window update
17606 	 * to be sent.  We also should avoid sending a flurry of window
17607 	 * updates when the socket buffer had queued a lot of data and the
17608 	 * application is doing small reads.
17609 	 *
17610 	 * Prevent a flurry of pointless window updates by only sending an
17611 	 * update when we can increase the advertized window by more than
17612 	 * 1/4th of the socket buffer capacity.  When the buffer is getting
17613 	 * full or is very small be more aggressive and send an update
17614 	 * whenever we can increase by two mss sized segments. In all other
17615 	 * situations the ACK's to new incoming data will carry further
17616 	 * window increases.
17617 	 *
17618 	 * Don't send an independent window update if a delayed ACK is
17619 	 * pending (it will get piggy-backed on it) or the remote side
17620 	 * already has done a half-close and won't send more data.  Skip
17621 	 * this if the connection is in T/TCP half-open state.
17622 	 */
17623 	if (recwin > 0 && !(tp->t_flags & TF_NEEDSYN) &&
17624 	    !(tp->t_flags & TF_DELACK) &&
17625 	    !TCPS_HAVERCVDFIN(tp->t_state)) {
17626 		/*
17627 		 * "adv" is the amount we could increase the window, taking
17628 		 * into account that we are limited by TCP_MAXWIN <<
17629 		 * tp->rcv_scale.
17630 		 */
17631 		int32_t adv;
17632 		int oldwin;
17633 
17634 		adv = recwin;
17635 		if (SEQ_GT(tp->rcv_adv, tp->rcv_nxt)) {
17636 			oldwin = (tp->rcv_adv - tp->rcv_nxt);
17637 			if (adv > oldwin)
17638 			    adv -= oldwin;
17639 			else {
17640 				/* We can't increase the window */
17641 				adv = 0;
17642 			}
17643 		} else
17644 			oldwin = 0;
17645 
17646 		/*
17647 		 * If the new window size ends up being the same as or less
17648 		 * than the old size when it is scaled, then don't force
17649 		 * a window update.
17650 		 */
17651 		if (oldwin >> tp->rcv_scale >= (adv + oldwin) >> tp->rcv_scale)
17652 			goto dontupdate;
17653 
17654 		if (adv >= (int32_t)(2 * segsiz) &&
17655 		    (adv >= (int32_t)(so->so_rcv.sb_hiwat / 4) ||
17656 		     recwin <= (int32_t)(so->so_rcv.sb_hiwat / 8) ||
17657 		     so->so_rcv.sb_hiwat <= 8 * segsiz)) {
17658 			pass = 7;
17659 			goto send;
17660 		}
17661 		if (2 * adv >= (int32_t) so->so_rcv.sb_hiwat) {
17662 			pass = 23;
17663 			goto send;
17664 		}
17665 	}
17666 dontupdate:
17667 
17668 	/*
17669 	 * Send if we owe the peer an ACK, RST, SYN, or urgent data.  ACKNOW
17670 	 * is also a catch-all for the retransmit timer timeout case.
17671 	 */
17672 	if (tp->t_flags & TF_ACKNOW) {
17673 		pass = 8;
17674 		goto send;
17675 	}
17676 	if (((flags & TH_SYN) && (tp->t_flags & TF_NEEDSYN) == 0)) {
17677 		pass = 9;
17678 		goto send;
17679 	}
17680 	/*
17681 	 * If our state indicates that FIN should be sent and we have not
17682 	 * yet done so, then we need to send.
17683 	 */
17684 	if ((flags & TH_FIN) &&
17685 	    (tp->snd_nxt == tp->snd_una)) {
17686 		pass = 11;
17687 		goto send;
17688 	}
17689 	/*
17690 	 * No reason to send a segment, just return.
17691 	 */
17692 just_return:
17693 	SOCKBUF_UNLOCK(sb);
17694 just_return_nolock:
17695 	{
17696 		int app_limited = CTF_JR_SENT_DATA;
17697 
17698 		if (tot_len_this_send > 0) {
17699 			/* Make sure snd_nxt is up to max */
17700 			rack->r_ctl.fsb.recwin = recwin;
17701 			slot = rack_get_pacing_delay(rack, tp, tot_len_this_send, NULL, segsiz);
17702 			if ((error == 0) &&
17703 			    rack_use_rfo &&
17704 			    ((flags & (TH_SYN|TH_FIN)) == 0) &&
17705 			    (ipoptlen == 0) &&
17706 			    (tp->snd_nxt == tp->snd_max) &&
17707 			    (tp->rcv_numsacks == 0) &&
17708 			    rack->r_fsb_inited &&
17709 			    TCPS_HAVEESTABLISHED(tp->t_state) &&
17710 			    (rack->r_must_retran == 0) &&
17711 			    ((tp->t_flags & TF_NEEDFIN) == 0) &&
17712 			    (len > 0) && (orig_len > 0) &&
17713 			    (orig_len > len) &&
17714 			    ((orig_len - len) >= segsiz) &&
17715 			    ((optlen == 0) ||
17716 			     ((optlen == TCPOLEN_TSTAMP_APPA) && (to.to_flags & TOF_TS)))) {
17717 				/* We can send at least one more MSS using our fsb */
17718 
17719 				rack->r_fast_output = 1;
17720 				rack->r_ctl.fsb.m = sbsndmbuf(sb, (tp->snd_max - tp->snd_una), &rack->r_ctl.fsb.off);
17721 				rack->r_ctl.fsb.o_m_len = rack->r_ctl.fsb.m->m_len;
17722 				rack->r_ctl.fsb.tcp_flags = flags;
17723 				rack->r_ctl.fsb.left_to_send = orig_len - len;
17724 				if (hw_tls)
17725 					rack->r_ctl.fsb.hw_tls = 1;
17726 				else
17727 					rack->r_ctl.fsb.hw_tls = 0;
17728 				KASSERT((rack->r_ctl.fsb.left_to_send <= (sbavail(sb) - (tp->snd_max - tp->snd_una))),
17729 					("rack:%p left_to_send:%u sbavail:%u out:%u",
17730 					rack, rack->r_ctl.fsb.left_to_send, sbavail(sb),
17731 					 (tp->snd_max - tp->snd_una)));
17732 				if (rack->r_ctl.fsb.left_to_send < segsiz)
17733 					rack->r_fast_output = 0;
17734 				else {
17735 					if (rack->r_ctl.fsb.left_to_send == (sbavail(sb) - (tp->snd_max - tp->snd_una)))
17736 						rack->r_ctl.fsb.rfo_apply_push = 1;
17737 					else
17738 						rack->r_ctl.fsb.rfo_apply_push = 0;
17739 				}
17740 			} else
17741 				rack->r_fast_output = 0;
17742 
17743 
17744 			rack_log_fsb(rack, tp, so, flags,
17745 				     ipoptlen, orig_len, len, 0,
17746 				     1, optlen, __LINE__, 1);
17747 			if (SEQ_GT(tp->snd_max, tp->snd_nxt))
17748 				tp->snd_nxt = tp->snd_max;
17749 		} else {
17750 			int end_window = 0;
17751 			uint32_t seq = tp->gput_ack;
17752 
17753 			rsm = RB_MAX(rack_rb_tree_head, &rack->r_ctl.rc_mtree);
17754 			if (rsm) {
17755 				/*
17756 				 * Mark the last sent that we just-returned (hinting
17757 				 * that delayed ack may play a role in any rtt measurement).
17758 				 */
17759 				rsm->r_just_ret = 1;
17760 			}
17761 			counter_u64_add(rack_out_size[TCP_MSS_ACCT_JUSTRET], 1);
17762 			rack->r_ctl.rc_agg_delayed = 0;
17763 			rack->r_early = 0;
17764 			rack->r_late = 0;
17765 			rack->r_ctl.rc_agg_early = 0;
17766 			if ((ctf_outstanding(tp) +
17767 			     min(max(segsiz, (rack->r_ctl.rc_high_rwnd/2)),
17768 				 minseg)) >= tp->snd_wnd) {
17769 				/* We are limited by the rwnd */
17770 				app_limited = CTF_JR_RWND_LIMITED;
17771 				if (IN_FASTRECOVERY(tp->t_flags))
17772 				    rack->r_ctl.rc_prr_sndcnt = 0;
17773 			} else if (ctf_outstanding(tp) >= sbavail(sb)) {
17774 				/* We are limited by whats available -- app limited */
17775 				app_limited = CTF_JR_APP_LIMITED;
17776 				if (IN_FASTRECOVERY(tp->t_flags))
17777 				    rack->r_ctl.rc_prr_sndcnt = 0;
17778 			} else if ((idle == 0) &&
17779 				   ((tp->t_flags & TF_NODELAY) == 0) &&
17780 				   ((uint32_t)len + (uint32_t)sb_offset >= sbavail(sb)) &&
17781 				   (len < segsiz)) {
17782 				/*
17783 				 * No delay is not on and the
17784 				 * user is sending less than 1MSS. This
17785 				 * brings out SWS avoidance so we
17786 				 * don't send. Another app-limited case.
17787 				 */
17788 				app_limited = CTF_JR_APP_LIMITED;
17789 			} else if (tp->t_flags & TF_NOPUSH) {
17790 				/*
17791 				 * The user has requested no push of
17792 				 * the last segment and we are
17793 				 * at the last segment. Another app
17794 				 * limited case.
17795 				 */
17796 				app_limited = CTF_JR_APP_LIMITED;
17797 			} else if ((ctf_outstanding(tp) + minseg) > cwnd_to_use) {
17798 				/* Its the cwnd */
17799 				app_limited = CTF_JR_CWND_LIMITED;
17800 			} else if (IN_FASTRECOVERY(tp->t_flags) &&
17801 				   (rack->rack_no_prr == 0) &&
17802 				   (rack->r_ctl.rc_prr_sndcnt < segsiz)) {
17803 				app_limited = CTF_JR_PRR;
17804 			} else {
17805 				/* Now why here are we not sending? */
17806 #ifdef NOW
17807 #ifdef INVARIANTS
17808 				panic("rack:%p hit JR_ASSESSING case cwnd_to_use:%u?", rack, cwnd_to_use);
17809 #endif
17810 #endif
17811 				app_limited = CTF_JR_ASSESSING;
17812 			}
17813 			/*
17814 			 * App limited in some fashion, for our pacing GP
17815 			 * measurements we don't want any gap (even cwnd).
17816 			 * Close  down the measurement window.
17817 			 */
17818 			if (rack_cwnd_block_ends_measure &&
17819 			    ((app_limited == CTF_JR_CWND_LIMITED) ||
17820 			     (app_limited == CTF_JR_PRR))) {
17821 				/*
17822 				 * The reason we are not sending is
17823 				 * the cwnd (or prr). We have been configured
17824 				 * to end the measurement window in
17825 				 * this case.
17826 				 */
17827 				end_window = 1;
17828 			} else if (rack_rwnd_block_ends_measure &&
17829 				   (app_limited == CTF_JR_RWND_LIMITED)) {
17830 				/*
17831 				 * We are rwnd limited and have been
17832 				 * configured to end the measurement
17833 				 * window in this case.
17834 				 */
17835 				end_window = 1;
17836 			} else if (app_limited == CTF_JR_APP_LIMITED) {
17837 				/*
17838 				 * A true application limited period, we have
17839 				 * ran out of data.
17840 				 */
17841 				end_window = 1;
17842 			} else if (app_limited == CTF_JR_ASSESSING) {
17843 				/*
17844 				 * In the assessing case we hit the end of
17845 				 * the if/else and had no known reason
17846 				 * This will panic us under invariants..
17847 				 *
17848 				 * If we get this out in logs we need to
17849 				 * investagate which reason we missed.
17850 				 */
17851 				end_window = 1;
17852 			}
17853 			if (end_window) {
17854 				uint8_t log = 0;
17855 
17856 				/* Adjust the Gput measurement */
17857 				if ((tp->t_flags & TF_GPUTINPROG) &&
17858 				    SEQ_GT(tp->gput_ack, tp->snd_max)) {
17859 					tp->gput_ack = tp->snd_max;
17860 					if ((tp->gput_ack - tp->gput_seq) < (MIN_GP_WIN * segsiz)) {
17861 						/*
17862 						 * There is not enough to measure.
17863 						 */
17864 						tp->t_flags &= ~TF_GPUTINPROG;
17865 						rack_log_pacing_delay_calc(rack, (tp->gput_ack - tp->gput_seq) /*flex2*/,
17866 									   rack->r_ctl.rc_gp_srtt /*flex1*/,
17867 									   tp->gput_seq,
17868 									   0, 0, 18, __LINE__, NULL, 0);
17869 					} else
17870 						log = 1;
17871 				}
17872 				/* Mark the last packet has app limited */
17873 				rsm = RB_MAX(rack_rb_tree_head, &rack->r_ctl.rc_mtree);
17874 				if (rsm && ((rsm->r_flags & RACK_APP_LIMITED) == 0)) {
17875 					if (rack->r_ctl.rc_app_limited_cnt == 0)
17876 						rack->r_ctl.rc_end_appl = rack->r_ctl.rc_first_appl = rsm;
17877 					else {
17878 						/*
17879 						 * Go out to the end app limited and mark
17880 						 * this new one as next and move the end_appl up
17881 						 * to this guy.
17882 						 */
17883 						if (rack->r_ctl.rc_end_appl)
17884 							rack->r_ctl.rc_end_appl->r_nseq_appl = rsm->r_start;
17885 						rack->r_ctl.rc_end_appl = rsm;
17886 					}
17887 					rsm->r_flags |= RACK_APP_LIMITED;
17888 					rack->r_ctl.rc_app_limited_cnt++;
17889 				}
17890 				if (log)
17891 					rack_log_pacing_delay_calc(rack,
17892 								   rack->r_ctl.rc_app_limited_cnt, seq,
17893 								   tp->gput_ack, 0, 0, 4, __LINE__, NULL, 0);
17894 			}
17895 		}
17896 		if (slot) {
17897 			/* set the rack tcb into the slot N */
17898 			counter_u64_add(rack_paced_segments, 1);
17899 		} else if (tot_len_this_send) {
17900 			counter_u64_add(rack_unpaced_segments, 1);
17901 		}
17902 		/* Check if we need to go into persists or not */
17903 		if ((tp->snd_max == tp->snd_una) &&
17904 		    TCPS_HAVEESTABLISHED(tp->t_state) &&
17905 		    sbavail(sb) &&
17906 		    (sbavail(sb) > tp->snd_wnd) &&
17907 		    (tp->snd_wnd < min((rack->r_ctl.rc_high_rwnd/2), minseg))) {
17908 			/* Yes lets make sure to move to persist before timer-start */
17909 			rack_enter_persist(tp, rack, rack->r_ctl.rc_rcvtime);
17910 		}
17911 		rack_start_hpts_timer(rack, tp, cts, slot, tot_len_this_send, sup_rack);
17912 		rack_log_type_just_return(rack, cts, tot_len_this_send, slot, hpts_calling, app_limited, cwnd_to_use);
17913 	}
17914 #ifdef NETFLIX_SHARED_CWND
17915 	if ((sbavail(sb) == 0) &&
17916 	    rack->r_ctl.rc_scw) {
17917 		tcp_shared_cwnd_idle(rack->r_ctl.rc_scw, rack->r_ctl.rc_scw_index);
17918 		rack->rack_scwnd_is_idle = 1;
17919 	}
17920 #endif
17921 #ifdef TCP_ACCOUNTING
17922 	if (tot_len_this_send > 0) {
17923 		crtsc = get_cyclecount();
17924 		if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
17925 			tp->tcp_cnt_counters[SND_OUT_DATA]++;
17926 		}
17927 		counter_u64_add(tcp_cnt_counters[SND_OUT_DATA], 1);
17928 		if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
17929 			tp->tcp_proc_time[SND_OUT_DATA] += (crtsc - ts_val);
17930 		}
17931 		counter_u64_add(tcp_proc_time[SND_OUT_DATA], (crtsc - ts_val));
17932 		if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
17933 			tp->tcp_cnt_counters[CNT_OF_MSS_OUT] += ((tot_len_this_send + segsiz - 1) / segsiz);
17934 		}
17935 		counter_u64_add(tcp_cnt_counters[CNT_OF_MSS_OUT], ((tot_len_this_send + segsiz - 1) / segsiz));
17936 	} else {
17937 		crtsc = get_cyclecount();
17938 		if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
17939 			tp->tcp_cnt_counters[SND_LIMITED]++;
17940 		}
17941 		counter_u64_add(tcp_cnt_counters[SND_LIMITED], 1);
17942 		if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
17943 			tp->tcp_proc_time[SND_LIMITED] += (crtsc - ts_val);
17944 		}
17945 		counter_u64_add(tcp_proc_time[SND_LIMITED], (crtsc - ts_val));
17946 	}
17947 	sched_unpin();
17948 #endif
17949 	return (0);
17950 
17951 send:
17952 	if (rsm || sack_rxmit)
17953 		counter_u64_add(rack_nfto_resend, 1);
17954 	else
17955 		counter_u64_add(rack_non_fto_send, 1);
17956 	if ((flags & TH_FIN) &&
17957 	    sbavail(sb)) {
17958 		/*
17959 		 * We do not transmit a FIN
17960 		 * with data outstanding. We
17961 		 * need to make it so all data
17962 		 * is acked first.
17963 		 */
17964 		flags &= ~TH_FIN;
17965 	}
17966 	/* Enforce stack imposed max seg size if we have one */
17967 	if (rack->r_ctl.rc_pace_max_segs &&
17968 	    (len > rack->r_ctl.rc_pace_max_segs)) {
17969 		mark = 1;
17970 		len = rack->r_ctl.rc_pace_max_segs;
17971 	}
17972 	SOCKBUF_LOCK_ASSERT(sb);
17973 	if (len > 0) {
17974 		if (len >= segsiz)
17975 			tp->t_flags2 |= TF2_PLPMTU_MAXSEGSNT;
17976 		else
17977 			tp->t_flags2 &= ~TF2_PLPMTU_MAXSEGSNT;
17978 	}
17979 	/*
17980 	 * Before ESTABLISHED, force sending of initial options unless TCP
17981 	 * set not to do any options. NOTE: we assume that the IP/TCP header
17982 	 * plus TCP options always fit in a single mbuf, leaving room for a
17983 	 * maximum link header, i.e. max_linkhdr + sizeof (struct tcpiphdr)
17984 	 * + optlen <= MCLBYTES
17985 	 */
17986 	optlen = 0;
17987 #ifdef INET6
17988 	if (isipv6)
17989 		hdrlen = sizeof(struct ip6_hdr) + sizeof(struct tcphdr);
17990 	else
17991 #endif
17992 		hdrlen = sizeof(struct tcpiphdr);
17993 
17994 	/*
17995 	 * Compute options for segment. We only have to care about SYN and
17996 	 * established connection segments.  Options for SYN-ACK segments
17997 	 * are handled in TCP syncache.
17998 	 */
17999 	to.to_flags = 0;
18000 	if ((tp->t_flags & TF_NOOPT) == 0) {
18001 		/* Maximum segment size. */
18002 		if (flags & TH_SYN) {
18003 			tp->snd_nxt = tp->iss;
18004 			to.to_mss = tcp_mssopt(&inp->inp_inc);
18005 			if (tp->t_port)
18006 				to.to_mss -= V_tcp_udp_tunneling_overhead;
18007 			to.to_flags |= TOF_MSS;
18008 
18009 			/*
18010 			 * On SYN or SYN|ACK transmits on TFO connections,
18011 			 * only include the TFO option if it is not a
18012 			 * retransmit, as the presence of the TFO option may
18013 			 * have caused the original SYN or SYN|ACK to have
18014 			 * been dropped by a middlebox.
18015 			 */
18016 			if (IS_FASTOPEN(tp->t_flags) &&
18017 			    (tp->t_rxtshift == 0)) {
18018 				if (tp->t_state == TCPS_SYN_RECEIVED) {
18019 					to.to_tfo_len = TCP_FASTOPEN_COOKIE_LEN;
18020 					to.to_tfo_cookie =
18021 						(u_int8_t *)&tp->t_tfo_cookie.server;
18022 					to.to_flags |= TOF_FASTOPEN;
18023 					wanted_cookie = 1;
18024 				} else if (tp->t_state == TCPS_SYN_SENT) {
18025 					to.to_tfo_len =
18026 						tp->t_tfo_client_cookie_len;
18027 					to.to_tfo_cookie =
18028 						tp->t_tfo_cookie.client;
18029 					to.to_flags |= TOF_FASTOPEN;
18030 					wanted_cookie = 1;
18031 					/*
18032 					 * If we wind up having more data to
18033 					 * send with the SYN than can fit in
18034 					 * one segment, don't send any more
18035 					 * until the SYN|ACK comes back from
18036 					 * the other end.
18037 					 */
18038 					sendalot = 0;
18039 				}
18040 			}
18041 		}
18042 		/* Window scaling. */
18043 		if ((flags & TH_SYN) && (tp->t_flags & TF_REQ_SCALE)) {
18044 			to.to_wscale = tp->request_r_scale;
18045 			to.to_flags |= TOF_SCALE;
18046 		}
18047 		/* Timestamps. */
18048 		if ((tp->t_flags & TF_RCVD_TSTMP) ||
18049 		    ((flags & TH_SYN) && (tp->t_flags & TF_REQ_TSTMP))) {
18050 			to.to_tsval = ms_cts + tp->ts_offset;
18051 			to.to_tsecr = tp->ts_recent;
18052 			to.to_flags |= TOF_TS;
18053 		}
18054 		/* Set receive buffer autosizing timestamp. */
18055 		if (tp->rfbuf_ts == 0 &&
18056 		    (so->so_rcv.sb_flags & SB_AUTOSIZE))
18057 			tp->rfbuf_ts = tcp_ts_getticks();
18058 		/* Selective ACK's. */
18059 		if (tp->t_flags & TF_SACK_PERMIT) {
18060 			if (flags & TH_SYN)
18061 				to.to_flags |= TOF_SACKPERM;
18062 			else if (TCPS_HAVEESTABLISHED(tp->t_state) &&
18063 				 tp->rcv_numsacks > 0) {
18064 				to.to_flags |= TOF_SACK;
18065 				to.to_nsacks = tp->rcv_numsacks;
18066 				to.to_sacks = (u_char *)tp->sackblks;
18067 			}
18068 		}
18069 #if defined(IPSEC_SUPPORT) || defined(TCP_SIGNATURE)
18070 		/* TCP-MD5 (RFC2385). */
18071 		if (tp->t_flags & TF_SIGNATURE)
18072 			to.to_flags |= TOF_SIGNATURE;
18073 #endif				/* TCP_SIGNATURE */
18074 
18075 		/* Processing the options. */
18076 		hdrlen += optlen = tcp_addoptions(&to, opt);
18077 		/*
18078 		 * If we wanted a TFO option to be added, but it was unable
18079 		 * to fit, ensure no data is sent.
18080 		 */
18081 		if (IS_FASTOPEN(tp->t_flags) && wanted_cookie &&
18082 		    !(to.to_flags & TOF_FASTOPEN))
18083 			len = 0;
18084 	}
18085 	if (tp->t_port) {
18086 		if (V_tcp_udp_tunneling_port == 0) {
18087 			/* The port was removed?? */
18088 			SOCKBUF_UNLOCK(&so->so_snd);
18089 #ifdef TCP_ACCOUNTING
18090 			crtsc = get_cyclecount();
18091 			if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
18092 				tp->tcp_cnt_counters[SND_OUT_FAIL]++;
18093 			}
18094 			counter_u64_add(tcp_cnt_counters[SND_OUT_FAIL], 1);
18095 			if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
18096 				tp->tcp_proc_time[SND_OUT_FAIL] += (crtsc - ts_val);
18097 			}
18098 			counter_u64_add(tcp_proc_time[SND_OUT_FAIL], (crtsc - ts_val));
18099 			sched_unpin();
18100 #endif
18101 			return (EHOSTUNREACH);
18102 		}
18103 		hdrlen += sizeof(struct udphdr);
18104 	}
18105 #ifdef INET6
18106 	if (isipv6)
18107 		ipoptlen = ip6_optlen(tp->t_inpcb);
18108 	else
18109 #endif
18110 		if (tp->t_inpcb->inp_options)
18111 			ipoptlen = tp->t_inpcb->inp_options->m_len -
18112 				offsetof(struct ipoption, ipopt_list);
18113 		else
18114 			ipoptlen = 0;
18115 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
18116 	ipoptlen += ipsec_optlen;
18117 #endif
18118 
18119 	/*
18120 	 * Adjust data length if insertion of options will bump the packet
18121 	 * length beyond the t_maxseg length. Clear the FIN bit because we
18122 	 * cut off the tail of the segment.
18123 	 */
18124 	if (len + optlen + ipoptlen > tp->t_maxseg) {
18125 		if (tso) {
18126 			uint32_t if_hw_tsomax;
18127 			uint32_t moff;
18128 			int32_t max_len;
18129 
18130 			/* extract TSO information */
18131 			if_hw_tsomax = tp->t_tsomax;
18132 			if_hw_tsomaxsegcount = tp->t_tsomaxsegcount;
18133 			if_hw_tsomaxsegsize = tp->t_tsomaxsegsize;
18134 			KASSERT(ipoptlen == 0,
18135 				("%s: TSO can't do IP options", __func__));
18136 
18137 			/*
18138 			 * Check if we should limit by maximum payload
18139 			 * length:
18140 			 */
18141 			if (if_hw_tsomax != 0) {
18142 				/* compute maximum TSO length */
18143 				max_len = (if_hw_tsomax - hdrlen -
18144 					   max_linkhdr);
18145 				if (max_len <= 0) {
18146 					len = 0;
18147 				} else if (len > max_len) {
18148 					sendalot = 1;
18149 					len = max_len;
18150 					mark = 2;
18151 				}
18152 			}
18153 			/*
18154 			 * Prevent the last segment from being fractional
18155 			 * unless the send sockbuf can be emptied:
18156 			 */
18157 			max_len = (tp->t_maxseg - optlen);
18158 			if ((sb_offset + len) < sbavail(sb)) {
18159 				moff = len % (u_int)max_len;
18160 				if (moff != 0) {
18161 					mark = 3;
18162 					len -= moff;
18163 				}
18164 			}
18165 			/*
18166 			 * In case there are too many small fragments don't
18167 			 * use TSO:
18168 			 */
18169 			if (len <= segsiz) {
18170 				mark = 4;
18171 				tso = 0;
18172 			}
18173 			/*
18174 			 * Send the FIN in a separate segment after the bulk
18175 			 * sending is done. We don't trust the TSO
18176 			 * implementations to clear the FIN flag on all but
18177 			 * the last segment.
18178 			 */
18179 			if (tp->t_flags & TF_NEEDFIN) {
18180 				sendalot = 4;
18181 			}
18182 		} else {
18183 			mark = 5;
18184 			if (optlen + ipoptlen >= tp->t_maxseg) {
18185 				/*
18186 				 * Since we don't have enough space to put
18187 				 * the IP header chain and the TCP header in
18188 				 * one packet as required by RFC 7112, don't
18189 				 * send it. Also ensure that at least one
18190 				 * byte of the payload can be put into the
18191 				 * TCP segment.
18192 				 */
18193 				SOCKBUF_UNLOCK(&so->so_snd);
18194 				error = EMSGSIZE;
18195 				sack_rxmit = 0;
18196 				goto out;
18197 			}
18198 			len = tp->t_maxseg - optlen - ipoptlen;
18199 			sendalot = 5;
18200 		}
18201 	} else {
18202 		tso = 0;
18203 		mark = 6;
18204 	}
18205 	KASSERT(len + hdrlen + ipoptlen <= IP_MAXPACKET,
18206 		("%s: len > IP_MAXPACKET", __func__));
18207 #ifdef DIAGNOSTIC
18208 #ifdef INET6
18209 	if (max_linkhdr + hdrlen > MCLBYTES)
18210 #else
18211 		if (max_linkhdr + hdrlen > MHLEN)
18212 #endif
18213 			panic("tcphdr too big");
18214 #endif
18215 
18216 	/*
18217 	 * This KASSERT is here to catch edge cases at a well defined place.
18218 	 * Before, those had triggered (random) panic conditions further
18219 	 * down.
18220 	 */
18221 	KASSERT(len >= 0, ("[%s:%d]: len < 0", __func__, __LINE__));
18222 	if ((len == 0) &&
18223 	    (flags & TH_FIN) &&
18224 	    (sbused(sb))) {
18225 		/*
18226 		 * We have outstanding data, don't send a fin by itself!.
18227 		 */
18228 		goto just_return;
18229 	}
18230 	/*
18231 	 * Grab a header mbuf, attaching a copy of data to be transmitted,
18232 	 * and initialize the header from the template for sends on this
18233 	 * connection.
18234 	 */
18235 	hw_tls = (sb->sb_flags & SB_TLS_IFNET) != 0;
18236 	if (len) {
18237 		uint32_t max_val;
18238 		uint32_t moff;
18239 
18240 		if (rack->r_ctl.rc_pace_max_segs)
18241 			max_val = rack->r_ctl.rc_pace_max_segs;
18242 		else if (rack->rc_user_set_max_segs)
18243 			max_val = rack->rc_user_set_max_segs * segsiz;
18244 		else
18245 			max_val = len;
18246 		/*
18247 		 * We allow a limit on sending with hptsi.
18248 		 */
18249 		if (len > max_val) {
18250 			mark = 7;
18251 			len = max_val;
18252 		}
18253 #ifdef INET6
18254 		if (MHLEN < hdrlen + max_linkhdr)
18255 			m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR);
18256 		else
18257 #endif
18258 			m = m_gethdr(M_NOWAIT, MT_DATA);
18259 
18260 		if (m == NULL) {
18261 			SOCKBUF_UNLOCK(sb);
18262 			error = ENOBUFS;
18263 			sack_rxmit = 0;
18264 			goto out;
18265 		}
18266 		m->m_data += max_linkhdr;
18267 		m->m_len = hdrlen;
18268 
18269 		/*
18270 		 * Start the m_copy functions from the closest mbuf to the
18271 		 * sb_offset in the socket buffer chain.
18272 		 */
18273 		mb = sbsndptr_noadv(sb, sb_offset, &moff);
18274 		s_mb = mb;
18275 		s_moff = moff;
18276 		if (len <= MHLEN - hdrlen - max_linkhdr && !hw_tls) {
18277 			m_copydata(mb, moff, (int)len,
18278 				   mtod(m, caddr_t)+hdrlen);
18279 			if (SEQ_LT(tp->snd_nxt, tp->snd_max))
18280 				sbsndptr_adv(sb, mb, len);
18281 			m->m_len += len;
18282 		} else {
18283 			struct sockbuf *msb;
18284 
18285 			if (SEQ_LT(tp->snd_nxt, tp->snd_max))
18286 				msb = NULL;
18287 			else
18288 				msb = sb;
18289 			m->m_next = tcp_m_copym(
18290 				mb, moff, &len,
18291 				if_hw_tsomaxsegcount, if_hw_tsomaxsegsize, msb,
18292 				((rsm == NULL) ? hw_tls : 0)
18293 #ifdef NETFLIX_COPY_ARGS
18294 				, &filled_all
18295 #endif
18296 				);
18297 			if (len <= (tp->t_maxseg - optlen)) {
18298 				/*
18299 				 * Must have ran out of mbufs for the copy
18300 				 * shorten it to no longer need tso. Lets
18301 				 * not put on sendalot since we are low on
18302 				 * mbufs.
18303 				 */
18304 				tso = 0;
18305 			}
18306 			if (m->m_next == NULL) {
18307 				SOCKBUF_UNLOCK(sb);
18308 				(void)m_free(m);
18309 				error = ENOBUFS;
18310 				sack_rxmit = 0;
18311 				goto out;
18312 			}
18313 		}
18314 		if (SEQ_LT(tp->snd_nxt, tp->snd_max) || sack_rxmit) {
18315 			if (rsm && (rsm->r_flags & RACK_TLP)) {
18316 				/*
18317 				 * TLP should not count in retran count, but
18318 				 * in its own bin
18319 				 */
18320 				counter_u64_add(rack_tlp_retran, 1);
18321 				counter_u64_add(rack_tlp_retran_bytes, len);
18322 			} else {
18323 				tp->t_sndrexmitpack++;
18324 				KMOD_TCPSTAT_INC(tcps_sndrexmitpack);
18325 				KMOD_TCPSTAT_ADD(tcps_sndrexmitbyte, len);
18326 			}
18327 #ifdef STATS
18328 			stats_voi_update_abs_u32(tp->t_stats, VOI_TCP_RETXPB,
18329 						 len);
18330 #endif
18331 		} else {
18332 			KMOD_TCPSTAT_INC(tcps_sndpack);
18333 			KMOD_TCPSTAT_ADD(tcps_sndbyte, len);
18334 #ifdef STATS
18335 			stats_voi_update_abs_u64(tp->t_stats, VOI_TCP_TXPB,
18336 						 len);
18337 #endif
18338 		}
18339 		/*
18340 		 * If we're sending everything we've got, set PUSH. (This
18341 		 * will keep happy those implementations which only give
18342 		 * data to the user when a buffer fills or a PUSH comes in.)
18343 		 */
18344 		if (sb_offset + len == sbused(sb) &&
18345 		    sbused(sb) &&
18346 		    !(flags & TH_SYN)) {
18347 			flags |= TH_PUSH;
18348 			add_flag |= RACK_HAD_PUSH;
18349 		}
18350 
18351 		SOCKBUF_UNLOCK(sb);
18352 	} else {
18353 		SOCKBUF_UNLOCK(sb);
18354 		if (tp->t_flags & TF_ACKNOW)
18355 			KMOD_TCPSTAT_INC(tcps_sndacks);
18356 		else if (flags & (TH_SYN | TH_FIN | TH_RST))
18357 			KMOD_TCPSTAT_INC(tcps_sndctrl);
18358 		else
18359 			KMOD_TCPSTAT_INC(tcps_sndwinup);
18360 
18361 		m = m_gethdr(M_NOWAIT, MT_DATA);
18362 		if (m == NULL) {
18363 			error = ENOBUFS;
18364 			sack_rxmit = 0;
18365 			goto out;
18366 		}
18367 #ifdef INET6
18368 		if (isipv6 && (MHLEN < hdrlen + max_linkhdr) &&
18369 		    MHLEN >= hdrlen) {
18370 			M_ALIGN(m, hdrlen);
18371 		} else
18372 #endif
18373 			m->m_data += max_linkhdr;
18374 		m->m_len = hdrlen;
18375 	}
18376 	SOCKBUF_UNLOCK_ASSERT(sb);
18377 	m->m_pkthdr.rcvif = (struct ifnet *)0;
18378 #ifdef MAC
18379 	mac_inpcb_create_mbuf(inp, m);
18380 #endif
18381 	if ((ipoptlen == 0) && (rack->r_ctl.fsb.tcp_ip_hdr) &&  rack->r_fsb_inited) {
18382 #ifdef INET6
18383 		if (isipv6)
18384 			ip6 = (struct ip6_hdr *)rack->r_ctl.fsb.tcp_ip_hdr;
18385 		else
18386 #endif				/* INET6 */
18387 			ip = (struct ip *)rack->r_ctl.fsb.tcp_ip_hdr;
18388 		th = rack->r_ctl.fsb.th;
18389 		udp = rack->r_ctl.fsb.udp;
18390 		if (udp) {
18391 #ifdef INET6
18392 			if (isipv6)
18393 				ulen = hdrlen + len - sizeof(struct ip6_hdr);
18394 			else
18395 #endif				/* INET6 */
18396 				ulen = hdrlen + len - sizeof(struct ip);
18397 			udp->uh_ulen = htons(ulen);
18398 		}
18399 	} else {
18400 #ifdef INET6
18401 		if (isipv6) {
18402 			ip6 = mtod(m, struct ip6_hdr *);
18403 			if (tp->t_port) {
18404 				udp = (struct udphdr *)((caddr_t)ip6 + sizeof(struct ip6_hdr));
18405 				udp->uh_sport = htons(V_tcp_udp_tunneling_port);
18406 				udp->uh_dport = tp->t_port;
18407 				ulen = hdrlen + len - sizeof(struct ip6_hdr);
18408 				udp->uh_ulen = htons(ulen);
18409 				th = (struct tcphdr *)(udp + 1);
18410 			} else
18411 				th = (struct tcphdr *)(ip6 + 1);
18412 			tcpip_fillheaders(inp, tp->t_port, ip6, th);
18413 		} else
18414 #endif				/* INET6 */
18415 		{
18416 			ip = mtod(m, struct ip *);
18417 #ifdef TCPDEBUG
18418 			ipov = (struct ipovly *)ip;
18419 #endif
18420 			if (tp->t_port) {
18421 				udp = (struct udphdr *)((caddr_t)ip + sizeof(struct ip));
18422 				udp->uh_sport = htons(V_tcp_udp_tunneling_port);
18423 				udp->uh_dport = tp->t_port;
18424 				ulen = hdrlen + len - sizeof(struct ip);
18425 				udp->uh_ulen = htons(ulen);
18426 				th = (struct tcphdr *)(udp + 1);
18427 			} else
18428 				th = (struct tcphdr *)(ip + 1);
18429 			tcpip_fillheaders(inp, tp->t_port, ip, th);
18430 		}
18431 	}
18432 	/*
18433 	 * Fill in fields, remembering maximum advertised window for use in
18434 	 * delaying messages about window sizes. If resending a FIN, be sure
18435 	 * not to use a new sequence number.
18436 	 */
18437 	if (flags & TH_FIN && tp->t_flags & TF_SENTFIN &&
18438 	    tp->snd_nxt == tp->snd_max)
18439 		tp->snd_nxt--;
18440 	/*
18441 	 * If we are starting a connection, send ECN setup SYN packet. If we
18442 	 * are on a retransmit, we may resend those bits a number of times
18443 	 * as per RFC 3168.
18444 	 */
18445 	if (tp->t_state == TCPS_SYN_SENT && V_tcp_do_ecn == 1) {
18446 		if (tp->t_rxtshift >= 1) {
18447 			if (tp->t_rxtshift <= V_tcp_ecn_maxretries)
18448 				flags |= TH_ECE | TH_CWR;
18449 		} else
18450 			flags |= TH_ECE | TH_CWR;
18451 	}
18452 	/* Handle parallel SYN for ECN */
18453 	if ((tp->t_state == TCPS_SYN_RECEIVED) &&
18454 	    (tp->t_flags2 & TF2_ECN_SND_ECE)) {
18455 		flags |= TH_ECE;
18456 		tp->t_flags2 &= ~TF2_ECN_SND_ECE;
18457 	}
18458 	if (TCPS_HAVEESTABLISHED(tp->t_state) &&
18459 	    (tp->t_flags2 & TF2_ECN_PERMIT)) {
18460 		/*
18461 		 * If the peer has ECN, mark data packets with ECN capable
18462 		 * transmission (ECT). Ignore pure ack packets,
18463 		 * retransmissions.
18464 		 */
18465 		if (len > 0 && SEQ_GEQ(tp->snd_nxt, tp->snd_max) &&
18466 		    (sack_rxmit == 0)) {
18467 #ifdef INET6
18468 			if (isipv6)
18469 				ip6->ip6_flow |= htonl(IPTOS_ECN_ECT0 << 20);
18470 			else
18471 #endif
18472 				ip->ip_tos |= IPTOS_ECN_ECT0;
18473 			KMOD_TCPSTAT_INC(tcps_ecn_ect0);
18474 			/*
18475 			 * Reply with proper ECN notifications.
18476 			 * Only set CWR on new data segments.
18477 			 */
18478 			if (tp->t_flags2 & TF2_ECN_SND_CWR) {
18479 				flags |= TH_CWR;
18480 				tp->t_flags2 &= ~TF2_ECN_SND_CWR;
18481 			}
18482 		}
18483 		if (tp->t_flags2 & TF2_ECN_SND_ECE)
18484 			flags |= TH_ECE;
18485 	}
18486 	/*
18487 	 * If we are doing retransmissions, then snd_nxt will not reflect
18488 	 * the first unsent octet.  For ACK only packets, we do not want the
18489 	 * sequence number of the retransmitted packet, we want the sequence
18490 	 * number of the next unsent octet.  So, if there is no data (and no
18491 	 * SYN or FIN), use snd_max instead of snd_nxt when filling in
18492 	 * ti_seq.  But if we are in persist state, snd_max might reflect
18493 	 * one byte beyond the right edge of the window, so use snd_nxt in
18494 	 * that case, since we know we aren't doing a retransmission.
18495 	 * (retransmit and persist are mutually exclusive...)
18496 	 */
18497 	if (sack_rxmit == 0) {
18498 		if (len || (flags & (TH_SYN | TH_FIN))) {
18499 			th->th_seq = htonl(tp->snd_nxt);
18500 			rack_seq = tp->snd_nxt;
18501 		} else {
18502 			th->th_seq = htonl(tp->snd_max);
18503 			rack_seq = tp->snd_max;
18504 		}
18505 	} else {
18506 		th->th_seq = htonl(rsm->r_start);
18507 		rack_seq = rsm->r_start;
18508 	}
18509 	th->th_ack = htonl(tp->rcv_nxt);
18510 	th->th_flags = flags;
18511 	/*
18512 	 * Calculate receive window.  Don't shrink window, but avoid silly
18513 	 * window syndrome.
18514 	 * If a RST segment is sent, advertise a window of zero.
18515 	 */
18516 	if (flags & TH_RST) {
18517 		recwin = 0;
18518 	} else {
18519 		if (recwin < (long)(so->so_rcv.sb_hiwat / 4) &&
18520 		    recwin < (long)segsiz) {
18521 			recwin = 0;
18522 		}
18523 		if (SEQ_GT(tp->rcv_adv, tp->rcv_nxt) &&
18524 		    recwin < (long)(tp->rcv_adv - tp->rcv_nxt))
18525 			recwin = (long)(tp->rcv_adv - tp->rcv_nxt);
18526 	}
18527 
18528 	/*
18529 	 * According to RFC1323 the window field in a SYN (i.e., a <SYN> or
18530 	 * <SYN,ACK>) segment itself is never scaled.  The <SYN,ACK> case is
18531 	 * handled in syncache.
18532 	 */
18533 	if (flags & TH_SYN)
18534 		th->th_win = htons((u_short)
18535 				   (min(sbspace(&so->so_rcv), TCP_MAXWIN)));
18536 	else {
18537 		/* Avoid shrinking window with window scaling. */
18538 		recwin = roundup2(recwin, 1 << tp->rcv_scale);
18539 		th->th_win = htons((u_short)(recwin >> tp->rcv_scale));
18540 	}
18541 	/*
18542 	 * Adjust the RXWIN0SENT flag - indicate that we have advertised a 0
18543 	 * window.  This may cause the remote transmitter to stall.  This
18544 	 * flag tells soreceive() to disable delayed acknowledgements when
18545 	 * draining the buffer.  This can occur if the receiver is
18546 	 * attempting to read more data than can be buffered prior to
18547 	 * transmitting on the connection.
18548 	 */
18549 	if (th->th_win == 0) {
18550 		tp->t_sndzerowin++;
18551 		tp->t_flags |= TF_RXWIN0SENT;
18552 	} else
18553 		tp->t_flags &= ~TF_RXWIN0SENT;
18554 	tp->snd_up = tp->snd_una;	/* drag it along, its deprecated */
18555 	/* Now are we using fsb?, if so copy the template data to the mbuf */
18556 	if ((ipoptlen == 0) && (rack->r_ctl.fsb.tcp_ip_hdr) && rack->r_fsb_inited) {
18557 		uint8_t *cpto;
18558 
18559 		cpto = mtod(m, uint8_t *);
18560 		memcpy(cpto, rack->r_ctl.fsb.tcp_ip_hdr, rack->r_ctl.fsb.tcp_ip_hdr_len);
18561 		/*
18562 		 * We have just copied in:
18563 		 * IP/IP6
18564 		 * <optional udphdr>
18565 		 * tcphdr (no options)
18566 		 *
18567 		 * We need to grab the correct pointers into the mbuf
18568 		 * for both the tcp header, and possibly the udp header (if tunneling).
18569 		 * We do this by using the offset in the copy buffer and adding it
18570 		 * to the mbuf base pointer (cpto).
18571 		 */
18572 #ifdef INET6
18573 		if (isipv6)
18574 			ip6 = mtod(m, struct ip6_hdr *);
18575 		else
18576 #endif				/* INET6 */
18577 			ip = mtod(m, struct ip *);
18578 		th = (struct tcphdr *)(cpto + ((uint8_t *)rack->r_ctl.fsb.th - rack->r_ctl.fsb.tcp_ip_hdr));
18579 		/* If we have a udp header lets set it into the mbuf as well */
18580 		if (udp)
18581 			udp = (struct udphdr *)(cpto + ((uint8_t *)rack->r_ctl.fsb.udp - rack->r_ctl.fsb.tcp_ip_hdr));
18582 	}
18583 #if defined(IPSEC_SUPPORT) || defined(TCP_SIGNATURE)
18584 	if (to.to_flags & TOF_SIGNATURE) {
18585 		/*
18586 		 * Calculate MD5 signature and put it into the place
18587 		 * determined before.
18588 		 * NOTE: since TCP options buffer doesn't point into
18589 		 * mbuf's data, calculate offset and use it.
18590 		 */
18591 		if (!TCPMD5_ENABLED() || TCPMD5_OUTPUT(m, th,
18592 						       (u_char *)(th + 1) + (to.to_signature - opt)) != 0) {
18593 			/*
18594 			 * Do not send segment if the calculation of MD5
18595 			 * digest has failed.
18596 			 */
18597 			goto out;
18598 		}
18599 	}
18600 #endif
18601 	if (optlen) {
18602 		bcopy(opt, th + 1, optlen);
18603 		th->th_off = (sizeof(struct tcphdr) + optlen) >> 2;
18604 	}
18605 	/*
18606 	 * Put TCP length in extended header, and then checksum extended
18607 	 * header and data.
18608 	 */
18609 	m->m_pkthdr.len = hdrlen + len;	/* in6_cksum() need this */
18610 #ifdef INET6
18611 	if (isipv6) {
18612 		/*
18613 		 * ip6_plen is not need to be filled now, and will be filled
18614 		 * in ip6_output.
18615 		 */
18616 		if (tp->t_port) {
18617 			m->m_pkthdr.csum_flags = CSUM_UDP_IPV6;
18618 			m->m_pkthdr.csum_data = offsetof(struct udphdr, uh_sum);
18619 			udp->uh_sum = in6_cksum_pseudo(ip6, ulen, IPPROTO_UDP, 0);
18620 			th->th_sum = htons(0);
18621 			UDPSTAT_INC(udps_opackets);
18622 		} else {
18623 			m->m_pkthdr.csum_flags = CSUM_TCP_IPV6;
18624 			m->m_pkthdr.csum_data = offsetof(struct tcphdr, th_sum);
18625 			th->th_sum = in6_cksum_pseudo(ip6,
18626 						      sizeof(struct tcphdr) + optlen + len, IPPROTO_TCP,
18627 						      0);
18628 		}
18629 	}
18630 #endif
18631 #if defined(INET6) && defined(INET)
18632 	else
18633 #endif
18634 #ifdef INET
18635 	{
18636 		if (tp->t_port) {
18637 			m->m_pkthdr.csum_flags = CSUM_UDP;
18638 			m->m_pkthdr.csum_data = offsetof(struct udphdr, uh_sum);
18639 			udp->uh_sum = in_pseudo(ip->ip_src.s_addr,
18640 						ip->ip_dst.s_addr, htons(ulen + IPPROTO_UDP));
18641 			th->th_sum = htons(0);
18642 			UDPSTAT_INC(udps_opackets);
18643 		} else {
18644 			m->m_pkthdr.csum_flags = CSUM_TCP;
18645 			m->m_pkthdr.csum_data = offsetof(struct tcphdr, th_sum);
18646 			th->th_sum = in_pseudo(ip->ip_src.s_addr,
18647 					       ip->ip_dst.s_addr, htons(sizeof(struct tcphdr) +
18648 									IPPROTO_TCP + len + optlen));
18649 		}
18650 		/* IP version must be set here for ipv4/ipv6 checking later */
18651 		KASSERT(ip->ip_v == IPVERSION,
18652 			("%s: IP version incorrect: %d", __func__, ip->ip_v));
18653 	}
18654 #endif
18655 	/*
18656 	 * Enable TSO and specify the size of the segments. The TCP pseudo
18657 	 * header checksum is always provided. XXX: Fixme: This is currently
18658 	 * not the case for IPv6.
18659 	 */
18660 	if (tso) {
18661 		KASSERT(len > tp->t_maxseg - optlen,
18662 			("%s: len <= tso_segsz", __func__));
18663 		m->m_pkthdr.csum_flags |= CSUM_TSO;
18664 		m->m_pkthdr.tso_segsz = tp->t_maxseg - optlen;
18665 	}
18666 	KASSERT(len + hdrlen == m_length(m, NULL),
18667 		("%s: mbuf chain different than expected: %d + %u != %u",
18668 		 __func__, len, hdrlen, m_length(m, NULL)));
18669 
18670 #ifdef TCP_HHOOK
18671 	/* Run HHOOK_TCP_ESTABLISHED_OUT helper hooks. */
18672 	hhook_run_tcp_est_out(tp, th, &to, len, tso);
18673 #endif
18674 	/* We're getting ready to send; log now. */
18675 	if (tp->t_logstate != TCP_LOG_STATE_OFF) {
18676 		union tcp_log_stackspecific log;
18677 
18678 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
18679 		log.u_bbr.inhpts = rack->rc_inp->inp_in_hpts;
18680 		log.u_bbr.ininput = rack->rc_inp->inp_in_input;
18681 		if (rack->rack_no_prr)
18682 			log.u_bbr.flex1 = 0;
18683 		else
18684 			log.u_bbr.flex1 = rack->r_ctl.rc_prr_sndcnt;
18685 		log.u_bbr.flex2 = rack->r_ctl.rc_pace_min_segs;
18686 		log.u_bbr.flex3 = rack->r_ctl.rc_pace_max_segs;
18687 		log.u_bbr.flex4 = orig_len;
18688 		if (filled_all)
18689 			log.u_bbr.flex5 = 0x80000000;
18690 		else
18691 			log.u_bbr.flex5 = 0;
18692 		/* Save off the early/late values */
18693 		log.u_bbr.flex6 = rack->r_ctl.rc_agg_early;
18694 		log.u_bbr.applimited = rack->r_ctl.rc_agg_delayed;
18695 		log.u_bbr.bw_inuse = rack_get_bw(rack);
18696 		if (rsm || sack_rxmit) {
18697 			if (doing_tlp)
18698 				log.u_bbr.flex8 = 2;
18699 			else
18700 				log.u_bbr.flex8 = 1;
18701 		} else {
18702 			if (doing_tlp)
18703 				log.u_bbr.flex8 = 3;
18704 			else
18705 				log.u_bbr.flex8 = 0;
18706 		}
18707 		log.u_bbr.pacing_gain = rack_get_output_gain(rack, rsm);
18708 		log.u_bbr.flex7 = mark;
18709 		log.u_bbr.flex7 <<= 8;
18710 		log.u_bbr.flex7 |= pass;
18711 		log.u_bbr.pkts_out = tp->t_maxseg;
18712 		log.u_bbr.timeStamp = cts;
18713 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
18714 		log.u_bbr.lt_epoch = cwnd_to_use;
18715 		log.u_bbr.delivered = sendalot;
18716 		lgb = tcp_log_event_(tp, th, &so->so_rcv, &so->so_snd, TCP_LOG_OUT, ERRNO_UNK,
18717 				     len, &log, false, NULL, NULL, 0, &tv);
18718 	} else
18719 		lgb = NULL;
18720 
18721 	/*
18722 	 * Fill in IP length and desired time to live and send to IP level.
18723 	 * There should be a better way to handle ttl and tos; we could keep
18724 	 * them in the template, but need a way to checksum without them.
18725 	 */
18726 	/*
18727 	 * m->m_pkthdr.len should have been set before cksum calcuration,
18728 	 * because in6_cksum() need it.
18729 	 */
18730 #ifdef INET6
18731 	if (isipv6) {
18732 		/*
18733 		 * we separately set hoplimit for every segment, since the
18734 		 * user might want to change the value via setsockopt. Also,
18735 		 * desired default hop limit might be changed via Neighbor
18736 		 * Discovery.
18737 		 */
18738 		rack->r_ctl.fsb.hoplimit = ip6->ip6_hlim = in6_selecthlim(inp, NULL);
18739 
18740 		/*
18741 		 * Set the packet size here for the benefit of DTrace
18742 		 * probes. ip6_output() will set it properly; it's supposed
18743 		 * to include the option header lengths as well.
18744 		 */
18745 		ip6->ip6_plen = htons(m->m_pkthdr.len - sizeof(*ip6));
18746 
18747 		if (V_path_mtu_discovery && tp->t_maxseg > V_tcp_minmss)
18748 			tp->t_flags2 |= TF2_PLPMTU_PMTUD;
18749 		else
18750 			tp->t_flags2 &= ~TF2_PLPMTU_PMTUD;
18751 
18752 		if (tp->t_state == TCPS_SYN_SENT)
18753 			TCP_PROBE5(connect__request, NULL, tp, ip6, tp, th);
18754 
18755 		TCP_PROBE5(send, NULL, tp, ip6, tp, th);
18756 		/* TODO: IPv6 IP6TOS_ECT bit on */
18757 		error = ip6_output(m,
18758 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
18759 				   inp->in6p_outputopts,
18760 #else
18761 				   NULL,
18762 #endif
18763 				   &inp->inp_route6,
18764 				   ((rsm || sack_rxmit) ? IP_NO_SND_TAG_RL : 0),
18765 				   NULL, NULL, inp);
18766 
18767 		if (error == EMSGSIZE && inp->inp_route6.ro_nh != NULL)
18768 			mtu = inp->inp_route6.ro_nh->nh_mtu;
18769 	}
18770 #endif				/* INET6 */
18771 #if defined(INET) && defined(INET6)
18772 	else
18773 #endif
18774 #ifdef INET
18775 	{
18776 		ip->ip_len = htons(m->m_pkthdr.len);
18777 #ifdef INET6
18778 		if (inp->inp_vflag & INP_IPV6PROTO)
18779 			ip->ip_ttl = in6_selecthlim(inp, NULL);
18780 #endif				/* INET6 */
18781 		rack->r_ctl.fsb.hoplimit = ip->ip_ttl;
18782 		/*
18783 		 * If we do path MTU discovery, then we set DF on every
18784 		 * packet. This might not be the best thing to do according
18785 		 * to RFC3390 Section 2. However the tcp hostcache migitates
18786 		 * the problem so it affects only the first tcp connection
18787 		 * with a host.
18788 		 *
18789 		 * NB: Don't set DF on small MTU/MSS to have a safe
18790 		 * fallback.
18791 		 */
18792 		if (V_path_mtu_discovery && tp->t_maxseg > V_tcp_minmss) {
18793 			tp->t_flags2 |= TF2_PLPMTU_PMTUD;
18794 			if (tp->t_port == 0 || len < V_tcp_minmss) {
18795 				ip->ip_off |= htons(IP_DF);
18796 			}
18797 		} else {
18798 			tp->t_flags2 &= ~TF2_PLPMTU_PMTUD;
18799 		}
18800 
18801 		if (tp->t_state == TCPS_SYN_SENT)
18802 			TCP_PROBE5(connect__request, NULL, tp, ip, tp, th);
18803 
18804 		TCP_PROBE5(send, NULL, tp, ip, tp, th);
18805 
18806 		error = ip_output(m,
18807 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
18808 				  inp->inp_options,
18809 #else
18810 				  NULL,
18811 #endif
18812 				  &inp->inp_route,
18813 				  ((rsm || sack_rxmit) ? IP_NO_SND_TAG_RL : 0), 0,
18814 				  inp);
18815 		if (error == EMSGSIZE && inp->inp_route.ro_nh != NULL)
18816 			mtu = inp->inp_route.ro_nh->nh_mtu;
18817 	}
18818 #endif				/* INET */
18819 
18820 out:
18821 	if (lgb) {
18822 		lgb->tlb_errno = error;
18823 		lgb = NULL;
18824 	}
18825 	/*
18826 	 * In transmit state, time the transmission and arrange for the
18827 	 * retransmit.  In persist state, just set snd_max.
18828 	 */
18829 	if (error == 0) {
18830 		tcp_account_for_send(tp, len, (rsm != NULL), doing_tlp, hw_tls);
18831 		if (rsm && doing_tlp) {
18832 			rack->rc_last_sent_tlp_past_cumack = 0;
18833 			rack->rc_last_sent_tlp_seq_valid = 1;
18834 			rack->r_ctl.last_sent_tlp_seq = rsm->r_start;
18835 			rack->r_ctl.last_sent_tlp_len = rsm->r_end - rsm->r_start;
18836 		}
18837 		rack->forced_ack = 0;	/* If we send something zap the FA flag */
18838 		if (rsm && (doing_tlp == 0)) {
18839 			/* Set we retransmitted */
18840 			rack->rc_gp_saw_rec = 1;
18841 		} else {
18842 			if (cwnd_to_use > tp->snd_ssthresh) {
18843 				/* Set we sent in CA */
18844 				rack->rc_gp_saw_ca = 1;
18845 			} else {
18846 				/* Set we sent in SS */
18847 				rack->rc_gp_saw_ss = 1;
18848 			}
18849 		}
18850 		if (doing_tlp && (rsm == NULL)) {
18851 			/* Make sure new data TLP cnt is clear */
18852 			rack->r_ctl.rc_tlp_new_data = 0;
18853 		}
18854 		if (TCPS_HAVEESTABLISHED(tp->t_state) &&
18855 		    (tp->t_flags & TF_SACK_PERMIT) &&
18856 		    tp->rcv_numsacks > 0)
18857 			tcp_clean_dsack_blocks(tp);
18858 		tot_len_this_send += len;
18859 		if (len == 0)
18860 			counter_u64_add(rack_out_size[TCP_MSS_ACCT_SNDACK], 1);
18861 		else if (len == 1) {
18862 			counter_u64_add(rack_out_size[TCP_MSS_ACCT_PERSIST], 1);
18863 		} else if (len > 1) {
18864 			int idx;
18865 
18866 			idx = (len / segsiz) + 3;
18867 			if (idx >= TCP_MSS_ACCT_ATIMER)
18868 				counter_u64_add(rack_out_size[(TCP_MSS_ACCT_ATIMER-1)], 1);
18869 			else
18870 				counter_u64_add(rack_out_size[idx], 1);
18871 		}
18872 	}
18873 	if ((rack->rack_no_prr == 0) &&
18874 	    sub_from_prr &&
18875 	    (error == 0)) {
18876 		if (rack->r_ctl.rc_prr_sndcnt >= len)
18877 			rack->r_ctl.rc_prr_sndcnt -= len;
18878 		else
18879 			rack->r_ctl.rc_prr_sndcnt = 0;
18880 	}
18881 	sub_from_prr = 0;
18882 	if (doing_tlp) {
18883 		/* Make sure the TLP is added */
18884 		add_flag |= RACK_TLP;
18885 	} else if (rsm) {
18886 		/* If its a resend without TLP then it must not have the flag */
18887 		rsm->r_flags &= ~RACK_TLP;
18888 	}
18889 	rack_log_output(tp, &to, len, rack_seq, (uint8_t) flags, error,
18890 			rack_to_usec_ts(&tv),
18891 			rsm, add_flag, s_mb, s_moff, hw_tls);
18892 
18893 
18894 	if ((error == 0) &&
18895 	    (len > 0) &&
18896 	    (tp->snd_una == tp->snd_max))
18897 		rack->r_ctl.rc_tlp_rxt_last_time = cts;
18898 	{
18899 		tcp_seq startseq = tp->snd_nxt;
18900 
18901 		/* Track our lost count */
18902 		if (rsm && (doing_tlp == 0))
18903 			rack->r_ctl.rc_loss_count += rsm->r_end - rsm->r_start;
18904 		/*
18905 		 * Advance snd_nxt over sequence space of this segment.
18906 		 */
18907 		if (error)
18908 			/* We don't log or do anything with errors */
18909 			goto nomore;
18910 		if (doing_tlp == 0) {
18911 			if (rsm == NULL) {
18912 				/*
18913 				 * Not a retransmission of some
18914 				 * sort, new data is going out so
18915 				 * clear our TLP count and flag.
18916 				 */
18917 				rack->rc_tlp_in_progress = 0;
18918 				rack->r_ctl.rc_tlp_cnt_out = 0;
18919 			}
18920 		} else {
18921 			/*
18922 			 * We have just sent a TLP, mark that it is true
18923 			 * and make sure our in progress is set so we
18924 			 * continue to check the count.
18925 			 */
18926 			rack->rc_tlp_in_progress = 1;
18927 			rack->r_ctl.rc_tlp_cnt_out++;
18928 		}
18929 		if (flags & (TH_SYN | TH_FIN)) {
18930 			if (flags & TH_SYN)
18931 				tp->snd_nxt++;
18932 			if (flags & TH_FIN) {
18933 				tp->snd_nxt++;
18934 				tp->t_flags |= TF_SENTFIN;
18935 			}
18936 		}
18937 		/* In the ENOBUFS case we do *not* update snd_max */
18938 		if (sack_rxmit)
18939 			goto nomore;
18940 
18941 		tp->snd_nxt += len;
18942 		if (SEQ_GT(tp->snd_nxt, tp->snd_max)) {
18943 			if (tp->snd_una == tp->snd_max) {
18944 				/*
18945 				 * Update the time we just added data since
18946 				 * none was outstanding.
18947 				 */
18948 				rack_log_progress_event(rack, tp, ticks, PROGRESS_START, __LINE__);
18949 				tp->t_acktime = ticks;
18950 			}
18951 			tp->snd_max = tp->snd_nxt;
18952 			/*
18953 			 * Time this transmission if not a retransmission and
18954 			 * not currently timing anything.
18955 			 * This is only relevant in case of switching back to
18956 			 * the base stack.
18957 			 */
18958 			if (tp->t_rtttime == 0) {
18959 				tp->t_rtttime = ticks;
18960 				tp->t_rtseq = startseq;
18961 				KMOD_TCPSTAT_INC(tcps_segstimed);
18962 			}
18963 			if (len &&
18964 			    ((tp->t_flags & TF_GPUTINPROG) == 0))
18965 				rack_start_gp_measurement(tp, rack, startseq, sb_offset);
18966 		}
18967 		/*
18968 		 * If we are doing FO we need to update the mbuf position and subtract
18969 		 * this happens when the peer sends us duplicate information and
18970 		 * we thus want to send a DSACK.
18971 		 *
18972 		 * XXXRRS: This brings to mind a ?, when we send a DSACK block is TSO
18973 		 * turned off? If not then we are going to echo multiple DSACK blocks
18974 		 * out (with the TSO), which we should not be doing.
18975 		 */
18976 		if (rack->r_fast_output && len) {
18977 			if (rack->r_ctl.fsb.left_to_send > len)
18978 				rack->r_ctl.fsb.left_to_send -= len;
18979 			else
18980 				rack->r_ctl.fsb.left_to_send = 0;
18981 			if (rack->r_ctl.fsb.left_to_send < segsiz)
18982 				rack->r_fast_output = 0;
18983 			if (rack->r_fast_output) {
18984 				rack->r_ctl.fsb.m = sbsndmbuf(sb, (tp->snd_max - tp->snd_una), &rack->r_ctl.fsb.off);
18985 				rack->r_ctl.fsb.o_m_len = rack->r_ctl.fsb.m->m_len;
18986 			}
18987 		}
18988 	}
18989 nomore:
18990 	if (error) {
18991 		rack->r_ctl.rc_agg_delayed = 0;
18992 		rack->r_early = 0;
18993 		rack->r_late = 0;
18994 		rack->r_ctl.rc_agg_early = 0;
18995 		SOCKBUF_UNLOCK_ASSERT(sb);	/* Check gotos. */
18996 		/*
18997 		 * Failures do not advance the seq counter above. For the
18998 		 * case of ENOBUFS we will fall out and retry in 1ms with
18999 		 * the hpts. Everything else will just have to retransmit
19000 		 * with the timer.
19001 		 *
19002 		 * In any case, we do not want to loop around for another
19003 		 * send without a good reason.
19004 		 */
19005 		sendalot = 0;
19006 		switch (error) {
19007 		case EPERM:
19008 			tp->t_softerror = error;
19009 #ifdef TCP_ACCOUNTING
19010 			crtsc = get_cyclecount();
19011 			if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
19012 				tp->tcp_cnt_counters[SND_OUT_FAIL]++;
19013 			}
19014 			counter_u64_add(tcp_cnt_counters[SND_OUT_FAIL], 1);
19015 			if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
19016 				tp->tcp_proc_time[SND_OUT_FAIL] += (crtsc - ts_val);
19017 			}
19018 			counter_u64_add(tcp_proc_time[SND_OUT_FAIL], (crtsc - ts_val));
19019 			sched_unpin();
19020 #endif
19021 			return (error);
19022 		case ENOBUFS:
19023 			/*
19024 			 * Pace us right away to retry in a some
19025 			 * time
19026 			 */
19027 			slot = ((1 + rack->rc_enobuf) * HPTS_USEC_IN_MSEC);
19028 			if (rack->rc_enobuf < 0x7f)
19029 				rack->rc_enobuf++;
19030 			if (slot < (10 * HPTS_USEC_IN_MSEC))
19031 				slot = 10 * HPTS_USEC_IN_MSEC;
19032 			if (rack->r_ctl.crte != NULL) {
19033 				counter_u64_add(rack_saw_enobuf_hw, 1);
19034 				tcp_rl_log_enobuf(rack->r_ctl.crte);
19035 			}
19036 			counter_u64_add(rack_saw_enobuf, 1);
19037 			goto enobufs;
19038 		case EMSGSIZE:
19039 			/*
19040 			 * For some reason the interface we used initially
19041 			 * to send segments changed to another or lowered
19042 			 * its MTU. If TSO was active we either got an
19043 			 * interface without TSO capabilits or TSO was
19044 			 * turned off. If we obtained mtu from ip_output()
19045 			 * then update it and try again.
19046 			 */
19047 			if (tso)
19048 				tp->t_flags &= ~TF_TSO;
19049 			if (mtu != 0) {
19050 				tcp_mss_update(tp, -1, mtu, NULL, NULL);
19051 				goto again;
19052 			}
19053 			slot = 10 * HPTS_USEC_IN_MSEC;
19054 			rack_start_hpts_timer(rack, tp, cts, slot, 0, 0);
19055 #ifdef TCP_ACCOUNTING
19056 			crtsc = get_cyclecount();
19057 			if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
19058 				tp->tcp_cnt_counters[SND_OUT_FAIL]++;
19059 			}
19060 			counter_u64_add(tcp_cnt_counters[SND_OUT_FAIL], 1);
19061 			if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
19062 				tp->tcp_proc_time[SND_OUT_FAIL] += (crtsc - ts_val);
19063 			}
19064 			counter_u64_add(tcp_proc_time[SND_OUT_FAIL], (crtsc - ts_val));
19065 			sched_unpin();
19066 #endif
19067 			return (error);
19068 		case ENETUNREACH:
19069 			counter_u64_add(rack_saw_enetunreach, 1);
19070 		case EHOSTDOWN:
19071 		case EHOSTUNREACH:
19072 		case ENETDOWN:
19073 			if (TCPS_HAVERCVDSYN(tp->t_state)) {
19074 				tp->t_softerror = error;
19075 			}
19076 			/* FALLTHROUGH */
19077 		default:
19078 			slot = 10 * HPTS_USEC_IN_MSEC;
19079 			rack_start_hpts_timer(rack, tp, cts, slot, 0, 0);
19080 #ifdef TCP_ACCOUNTING
19081 			crtsc = get_cyclecount();
19082 			if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
19083 				tp->tcp_cnt_counters[SND_OUT_FAIL]++;
19084 			}
19085 			counter_u64_add(tcp_cnt_counters[SND_OUT_FAIL], 1);
19086 			if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
19087 				tp->tcp_proc_time[SND_OUT_FAIL] += (crtsc - ts_val);
19088 			}
19089 			counter_u64_add(tcp_proc_time[SND_OUT_FAIL], (crtsc - ts_val));
19090 			sched_unpin();
19091 #endif
19092 			return (error);
19093 		}
19094 	} else {
19095 		rack->rc_enobuf = 0;
19096 		if (IN_FASTRECOVERY(tp->t_flags) && rsm)
19097 			rack->r_ctl.retran_during_recovery += len;
19098 	}
19099 	KMOD_TCPSTAT_INC(tcps_sndtotal);
19100 
19101 	/*
19102 	 * Data sent (as far as we can tell). If this advertises a larger
19103 	 * window than any other segment, then remember the size of the
19104 	 * advertised window. Any pending ACK has now been sent.
19105 	 */
19106 	if (recwin > 0 && SEQ_GT(tp->rcv_nxt + recwin, tp->rcv_adv))
19107 		tp->rcv_adv = tp->rcv_nxt + recwin;
19108 
19109 	tp->last_ack_sent = tp->rcv_nxt;
19110 	tp->t_flags &= ~(TF_ACKNOW | TF_DELACK);
19111 enobufs:
19112 	if (sendalot) {
19113 		/* Do we need to turn off sendalot? */
19114 		if (rack->r_ctl.rc_pace_max_segs &&
19115 		    (tot_len_this_send >= rack->r_ctl.rc_pace_max_segs)) {
19116 			/* We hit our max. */
19117 			sendalot = 0;
19118 		} else if ((rack->rc_user_set_max_segs) &&
19119 			   (tot_len_this_send >= (rack->rc_user_set_max_segs * segsiz))) {
19120 			/* We hit the user defined max */
19121 			sendalot = 0;
19122 		}
19123 	}
19124 	if ((error == 0) && (flags & TH_FIN))
19125 		tcp_log_end_status(tp, TCP_EI_STATUS_SERVER_FIN);
19126 	if (flags & TH_RST) {
19127 		/*
19128 		 * We don't send again after sending a RST.
19129 		 */
19130 		slot = 0;
19131 		sendalot = 0;
19132 		if (error == 0)
19133 			tcp_log_end_status(tp, TCP_EI_STATUS_SERVER_RST);
19134 	} else if ((slot == 0) && (sendalot == 0) && tot_len_this_send) {
19135 		/*
19136 		 * Get our pacing rate, if an error
19137 		 * occurred in sending (ENOBUF) we would
19138 		 * hit the else if with slot preset. Other
19139 		 * errors return.
19140 		 */
19141 		slot = rack_get_pacing_delay(rack, tp, tot_len_this_send, rsm, segsiz);
19142 	}
19143 	if (rsm &&
19144 	    (rsm->r_flags & RACK_HAS_SYN) == 0 &&
19145 	    rack->use_rack_rr) {
19146 		/* Its a retransmit and we use the rack cheat? */
19147 		if ((slot == 0) ||
19148 		    (rack->rc_always_pace == 0) ||
19149 		    (rack->r_rr_config == 1)) {
19150 			/*
19151 			 * We have no pacing set or we
19152 			 * are using old-style rack or
19153 			 * we are overriden to use the old 1ms pacing.
19154 			 */
19155 			slot = rack->r_ctl.rc_min_to;
19156 		}
19157 	}
19158 	/* We have sent clear the flag */
19159 	rack->r_ent_rec_ns = 0;
19160 	if (rack->r_must_retran) {
19161 		if (rsm) {
19162 			rack->r_ctl.rc_out_at_rto -= (rsm->r_end - rsm->r_start);
19163 			if (SEQ_GEQ(rsm->r_end, rack->r_ctl.rc_snd_max_at_rto)) {
19164 				/*
19165 				 * We have retransmitted all.
19166 				 */
19167 				rack->r_must_retran = 0;
19168 				rack->r_ctl.rc_out_at_rto = 0;
19169 			}
19170 		} else if (SEQ_GEQ(tp->snd_max, rack->r_ctl.rc_snd_max_at_rto)) {
19171 			/*
19172 			 * Sending new data will also kill
19173 			 * the loop.
19174 			 */
19175 			rack->r_must_retran = 0;
19176 			rack->r_ctl.rc_out_at_rto = 0;
19177 		}
19178 	}
19179 	rack->r_ctl.fsb.recwin = recwin;
19180 	if ((tp->t_flags & (TF_WASCRECOVERY|TF_WASFRECOVERY)) &&
19181 	    SEQ_GT(tp->snd_max, rack->r_ctl.rc_snd_max_at_rto)) {
19182 		/*
19183 		 * We hit an RTO and now have past snd_max at the RTO
19184 		 * clear all the WAS flags.
19185 		 */
19186 		tp->t_flags &= ~(TF_WASCRECOVERY|TF_WASFRECOVERY);
19187 	}
19188 	if (slot) {
19189 		/* set the rack tcb into the slot N */
19190 		counter_u64_add(rack_paced_segments, 1);
19191 		if ((error == 0) &&
19192 		    rack_use_rfo &&
19193 		    ((flags & (TH_SYN|TH_FIN)) == 0) &&
19194 		    (rsm == NULL) &&
19195 		    (tp->snd_nxt == tp->snd_max) &&
19196 		    (ipoptlen == 0) &&
19197 		    (tp->rcv_numsacks == 0) &&
19198 		    rack->r_fsb_inited &&
19199 		    TCPS_HAVEESTABLISHED(tp->t_state) &&
19200 		    (rack->r_must_retran == 0) &&
19201 		    ((tp->t_flags & TF_NEEDFIN) == 0) &&
19202 		    (len > 0) && (orig_len > 0) &&
19203 		    (orig_len > len) &&
19204 		    ((orig_len - len) >= segsiz) &&
19205 		    ((optlen == 0) ||
19206 		     ((optlen == TCPOLEN_TSTAMP_APPA) && (to.to_flags & TOF_TS)))) {
19207 			/* We can send at least one more MSS using our fsb */
19208 
19209 			rack->r_fast_output = 1;
19210 			rack->r_ctl.fsb.m = sbsndmbuf(sb, (tp->snd_max - tp->snd_una), &rack->r_ctl.fsb.off);
19211 			rack->r_ctl.fsb.o_m_len = rack->r_ctl.fsb.m->m_len;
19212 			rack->r_ctl.fsb.tcp_flags = flags;
19213 			rack->r_ctl.fsb.left_to_send = orig_len - len;
19214 			if (hw_tls)
19215 				rack->r_ctl.fsb.hw_tls = 1;
19216 			else
19217 				rack->r_ctl.fsb.hw_tls = 0;
19218 			KASSERT((rack->r_ctl.fsb.left_to_send <= (sbavail(sb) - (tp->snd_max - tp->snd_una))),
19219 				("rack:%p left_to_send:%u sbavail:%u out:%u",
19220 				 rack, rack->r_ctl.fsb.left_to_send, sbavail(sb),
19221 				 (tp->snd_max - tp->snd_una)));
19222 			if (rack->r_ctl.fsb.left_to_send < segsiz)
19223 				rack->r_fast_output = 0;
19224 			else {
19225 				if (rack->r_ctl.fsb.left_to_send == (sbavail(sb) - (tp->snd_max - tp->snd_una)))
19226 					rack->r_ctl.fsb.rfo_apply_push = 1;
19227 				else
19228 					rack->r_ctl.fsb.rfo_apply_push = 0;
19229 			}
19230 		} else
19231 			rack->r_fast_output = 0;
19232 		rack_log_fsb(rack, tp, so, flags,
19233 			     ipoptlen, orig_len, len, error,
19234 			     (rsm == NULL), optlen, __LINE__, 2);
19235 	} else if (sendalot) {
19236 		int ret;
19237 
19238 		if (len)
19239 			counter_u64_add(rack_unpaced_segments, 1);
19240 		sack_rxmit = 0;
19241 		if ((error == 0) &&
19242 		    rack_use_rfo &&
19243 		    ((flags & (TH_SYN|TH_FIN)) == 0) &&
19244 		    (rsm == NULL) &&
19245 		    (ipoptlen == 0) &&
19246 		    (tp->rcv_numsacks == 0) &&
19247 		    (tp->snd_nxt == tp->snd_max) &&
19248 		    (rack->r_must_retran == 0) &&
19249 		    rack->r_fsb_inited &&
19250 		    TCPS_HAVEESTABLISHED(tp->t_state) &&
19251 		    ((tp->t_flags & TF_NEEDFIN) == 0) &&
19252 		    (len > 0) && (orig_len > 0) &&
19253 		    (orig_len > len) &&
19254 		    ((orig_len - len) >= segsiz) &&
19255 		    ((optlen == 0) ||
19256 		     ((optlen == TCPOLEN_TSTAMP_APPA) && (to.to_flags & TOF_TS)))) {
19257 			/* we can use fast_output for more */
19258 
19259 			rack->r_fast_output = 1;
19260 			rack->r_ctl.fsb.m = sbsndmbuf(sb, (tp->snd_max - tp->snd_una), &rack->r_ctl.fsb.off);
19261 			rack->r_ctl.fsb.o_m_len = rack->r_ctl.fsb.m->m_len;
19262 			rack->r_ctl.fsb.tcp_flags = flags;
19263 			rack->r_ctl.fsb.left_to_send = orig_len - len;
19264 			if (hw_tls)
19265 				rack->r_ctl.fsb.hw_tls = 1;
19266 			else
19267 				rack->r_ctl.fsb.hw_tls = 0;
19268 			KASSERT((rack->r_ctl.fsb.left_to_send <= (sbavail(sb) - (tp->snd_max - tp->snd_una))),
19269 				("rack:%p left_to_send:%u sbavail:%u out:%u",
19270 				 rack, rack->r_ctl.fsb.left_to_send, sbavail(sb),
19271 				 (tp->snd_max - tp->snd_una)));
19272 			if (rack->r_ctl.fsb.left_to_send < segsiz) {
19273 				rack->r_fast_output = 0;
19274 			}
19275 			if (rack->r_fast_output) {
19276 				if (rack->r_ctl.fsb.left_to_send == (sbavail(sb) - (tp->snd_max - tp->snd_una)))
19277 					rack->r_ctl.fsb.rfo_apply_push = 1;
19278 				else
19279 					rack->r_ctl.fsb.rfo_apply_push = 0;
19280 				rack_log_fsb(rack, tp, so, flags,
19281 					     ipoptlen, orig_len, len, error,
19282 					     (rsm == NULL), optlen, __LINE__, 3);
19283 				error = 0;
19284 				ret = rack_fast_output(tp, rack, ts_val, cts, ms_cts, &tv, tot_len_this_send, &error);
19285 				if (ret >= 0)
19286 					return (ret);
19287 			        else if (error)
19288 					goto nomore;
19289 
19290 			}
19291 		}
19292 		goto again;
19293 	} else if (len) {
19294 		counter_u64_add(rack_unpaced_segments, 1);
19295 	}
19296 	/* Assure when we leave that snd_nxt will point to top */
19297 	if (SEQ_GT(tp->snd_max, tp->snd_nxt))
19298 		tp->snd_nxt = tp->snd_max;
19299 	rack_start_hpts_timer(rack, tp, cts, slot, tot_len_this_send, 0);
19300 #ifdef TCP_ACCOUNTING
19301 	crtsc = get_cyclecount() - ts_val;
19302 	if (tot_len_this_send) {
19303 		if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
19304 			tp->tcp_cnt_counters[SND_OUT_DATA]++;
19305 		}
19306 		counter_u64_add(tcp_cnt_counters[SND_OUT_DATA], 1);
19307 		if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
19308 			tp->tcp_proc_time[SND_OUT_DATA] += crtsc;
19309 		}
19310 		counter_u64_add(tcp_proc_time[SND_OUT_DATA], crtsc);
19311 		if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
19312 			tp->tcp_cnt_counters[CNT_OF_MSS_OUT] += ((tot_len_this_send + segsiz - 1) /segsiz);
19313 		}
19314 		counter_u64_add(tcp_cnt_counters[CNT_OF_MSS_OUT], ((tot_len_this_send + segsiz - 1) /segsiz));
19315 	} else {
19316 		if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
19317 			tp->tcp_cnt_counters[SND_OUT_ACK]++;
19318 		}
19319 		counter_u64_add(tcp_cnt_counters[SND_OUT_ACK], 1);
19320 		if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
19321 			tp->tcp_proc_time[SND_OUT_ACK] += crtsc;
19322 		}
19323 		counter_u64_add(tcp_proc_time[SND_OUT_ACK], crtsc);
19324 	}
19325 	sched_unpin();
19326 #endif
19327 	if (error == ENOBUFS)
19328 		error = 0;
19329 	return (error);
19330 }
19331 
19332 static void
19333 rack_update_seg(struct tcp_rack *rack)
19334 {
19335 	uint32_t orig_val;
19336 
19337 	orig_val = rack->r_ctl.rc_pace_max_segs;
19338 	rack_set_pace_segments(rack->rc_tp, rack, __LINE__, NULL);
19339 	if (orig_val != rack->r_ctl.rc_pace_max_segs)
19340 		rack_log_pacing_delay_calc(rack, 0, 0, orig_val, 0, 0, 15, __LINE__, NULL, 0);
19341 }
19342 
19343 static void
19344 rack_mtu_change(struct tcpcb *tp)
19345 {
19346 	/*
19347 	 * The MSS may have changed
19348 	 */
19349 	struct tcp_rack *rack;
19350 	struct rack_sendmap *rsm;
19351 
19352 	rack = (struct tcp_rack *)tp->t_fb_ptr;
19353 	if (rack->r_ctl.rc_pace_min_segs != ctf_fixed_maxseg(tp)) {
19354 		/*
19355 		 * The MTU has changed we need to resend everything
19356 		 * since all we have sent is lost. We first fix
19357 		 * up the mtu though.
19358 		 */
19359 		rack_set_pace_segments(tp, rack, __LINE__, NULL);
19360 		/* We treat this like a full retransmit timeout without the cwnd adjustment */
19361 		rack_remxt_tmr(tp);
19362 		rack->r_fast_output = 0;
19363 		rack->r_ctl.rc_out_at_rto = ctf_flight_size(tp,
19364 						rack->r_ctl.rc_sacked);
19365 		rack->r_ctl.rc_snd_max_at_rto = tp->snd_max;
19366 		rack->r_must_retran = 1;
19367 		/* Mark all inflight to needing to be rxt'd */
19368 		TAILQ_FOREACH(rsm, &rack->r_ctl.rc_tmap, r_tnext) {
19369 			rsm->r_flags |= RACK_MUST_RXT;
19370 		}
19371 	}
19372 	sack_filter_clear(&rack->r_ctl.rack_sf, tp->snd_una);
19373 	/* We don't use snd_nxt to retransmit */
19374 	tp->snd_nxt = tp->snd_max;
19375 }
19376 
19377 static int
19378 rack_set_profile(struct tcp_rack *rack, int prof)
19379 {
19380 	int err = EINVAL;
19381 	if (prof == 1) {
19382 		/* pace_always=1 */
19383 		if (rack->rc_always_pace == 0) {
19384 			if (tcp_can_enable_pacing() == 0)
19385 				return (EBUSY);
19386 		}
19387 		rack->rc_always_pace = 1;
19388 		if (rack->use_fixed_rate || rack->gp_ready)
19389 			rack_set_cc_pacing(rack);
19390 		rack->rc_inp->inp_flags2 |= INP_SUPPORTS_MBUFQ;
19391 		rack->rack_attempt_hdwr_pace = 0;
19392 		/* cmpack=1 */
19393 		if (rack_use_cmp_acks)
19394 			rack->r_use_cmp_ack = 1;
19395 		if (TCPS_HAVEESTABLISHED(rack->rc_tp->t_state) &&
19396 		    rack->r_use_cmp_ack)
19397 			rack->rc_inp->inp_flags2 |= INP_MBUF_ACKCMP;
19398 		/* scwnd=1 */
19399 		rack->rack_enable_scwnd = 1;
19400 		/* dynamic=100 */
19401 		rack->rc_gp_dyn_mul = 1;
19402 		/* gp_inc_ca */
19403 		rack->r_ctl.rack_per_of_gp_ca = 100;
19404 		/* rrr_conf=3 */
19405 		rack->r_rr_config = 3;
19406 		/* npush=2 */
19407 		rack->r_ctl.rc_no_push_at_mrtt = 2;
19408 		/* fillcw=1 */
19409 		rack->rc_pace_to_cwnd = 1;
19410 		rack->rc_pace_fill_if_rttin_range = 0;
19411 		rack->rtt_limit_mul = 0;
19412 		/* noprr=1 */
19413 		rack->rack_no_prr = 1;
19414 		/* lscwnd=1 */
19415 		rack->r_limit_scw = 1;
19416 		/* gp_inc_rec */
19417 		rack->r_ctl.rack_per_of_gp_rec = 90;
19418 		err = 0;
19419 
19420 	} else if (prof == 3) {
19421 		/* Same as profile one execept fill_cw becomes 2 (less aggressive set) */
19422 		/* pace_always=1 */
19423 		if (rack->rc_always_pace == 0) {
19424 			if (tcp_can_enable_pacing() == 0)
19425 				return (EBUSY);
19426 		}
19427 		rack->rc_always_pace = 1;
19428 		if (rack->use_fixed_rate || rack->gp_ready)
19429 			rack_set_cc_pacing(rack);
19430 		rack->rc_inp->inp_flags2 |= INP_SUPPORTS_MBUFQ;
19431 		rack->rack_attempt_hdwr_pace = 0;
19432 		/* cmpack=1 */
19433 		if (rack_use_cmp_acks)
19434 			rack->r_use_cmp_ack = 1;
19435 		if (TCPS_HAVEESTABLISHED(rack->rc_tp->t_state) &&
19436 		    rack->r_use_cmp_ack)
19437 			rack->rc_inp->inp_flags2 |= INP_MBUF_ACKCMP;
19438 		/* scwnd=1 */
19439 		rack->rack_enable_scwnd = 1;
19440 		/* dynamic=100 */
19441 		rack->rc_gp_dyn_mul = 1;
19442 		/* gp_inc_ca */
19443 		rack->r_ctl.rack_per_of_gp_ca = 100;
19444 		/* rrr_conf=3 */
19445 		rack->r_rr_config = 3;
19446 		/* npush=2 */
19447 		rack->r_ctl.rc_no_push_at_mrtt = 2;
19448 		/* fillcw=2 */
19449 		rack->rc_pace_to_cwnd = 1;
19450 		rack->r_fill_less_agg = 1;
19451 		rack->rc_pace_fill_if_rttin_range = 0;
19452 		rack->rtt_limit_mul = 0;
19453 		/* noprr=1 */
19454 		rack->rack_no_prr = 1;
19455 		/* lscwnd=1 */
19456 		rack->r_limit_scw = 1;
19457 		/* gp_inc_rec */
19458 		rack->r_ctl.rack_per_of_gp_rec = 90;
19459 		err = 0;
19460 
19461 
19462 	} else if (prof == 2) {
19463 		/* cmpack=1 */
19464 		if (rack->rc_always_pace == 0) {
19465 			if (tcp_can_enable_pacing() == 0)
19466 				return (EBUSY);
19467 		}
19468 		rack->rc_always_pace = 1;
19469 		if (rack->use_fixed_rate || rack->gp_ready)
19470 			rack_set_cc_pacing(rack);
19471 		rack->r_use_cmp_ack = 1;
19472 		if (TCPS_HAVEESTABLISHED(rack->rc_tp->t_state))
19473 			rack->rc_inp->inp_flags2 |= INP_MBUF_ACKCMP;
19474 		/* pace_always=1 */
19475 		rack->rc_inp->inp_flags2 |= INP_SUPPORTS_MBUFQ;
19476 		/* scwnd=1 */
19477 		rack->rack_enable_scwnd = 1;
19478 		/* dynamic=100 */
19479 		rack->rc_gp_dyn_mul = 1;
19480 		rack->r_ctl.rack_per_of_gp_ca = 100;
19481 		/* rrr_conf=3 */
19482 		rack->r_rr_config = 3;
19483 		/* npush=2 */
19484 		rack->r_ctl.rc_no_push_at_mrtt = 2;
19485 		/* fillcw=1 */
19486 		rack->rc_pace_to_cwnd = 1;
19487 		rack->rc_pace_fill_if_rttin_range = 0;
19488 		rack->rtt_limit_mul = 0;
19489 		/* noprr=1 */
19490 		rack->rack_no_prr = 1;
19491 		/* lscwnd=0 */
19492 		rack->r_limit_scw = 0;
19493 		err = 0;
19494 	} else if (prof == 0) {
19495 		/* This changes things back to the default settings */
19496 		err = 0;
19497 		if (rack->rc_always_pace) {
19498 			tcp_decrement_paced_conn();
19499 			rack_undo_cc_pacing(rack);
19500 			rack->rc_always_pace = 0;
19501 		}
19502 		if (rack_pace_every_seg && tcp_can_enable_pacing()) {
19503 			rack->rc_always_pace = 1;
19504 			if (rack->use_fixed_rate || rack->gp_ready)
19505 				rack_set_cc_pacing(rack);
19506 		} else
19507 			rack->rc_always_pace = 0;
19508 		if (rack_dsack_std_based & 0x1) {
19509 			/* Basically this means all rack timers are at least (srtt + 1/4 srtt) */
19510 			rack->rc_rack_tmr_std_based = 1;
19511 		}
19512 		if (rack_dsack_std_based & 0x2) {
19513 			/* Basically this means  rack timers are extended based on dsack by up to (2 * srtt) */
19514 			rack->rc_rack_use_dsack = 1;
19515 		}
19516 		if (rack_use_cmp_acks)
19517 			rack->r_use_cmp_ack = 1;
19518 		else
19519 			rack->r_use_cmp_ack = 0;
19520 		if (rack_disable_prr)
19521 			rack->rack_no_prr = 1;
19522 		else
19523 			rack->rack_no_prr = 0;
19524 		if (rack_gp_no_rec_chg)
19525 			rack->rc_gp_no_rec_chg = 1;
19526 		else
19527 			rack->rc_gp_no_rec_chg = 0;
19528 		if (rack_enable_mqueue_for_nonpaced || rack->r_use_cmp_ack) {
19529 			rack->r_mbuf_queue = 1;
19530 			if (TCPS_HAVEESTABLISHED(rack->rc_tp->t_state))
19531 				rack->rc_inp->inp_flags2 |= INP_MBUF_ACKCMP;
19532 			rack->rc_inp->inp_flags2 |= INP_SUPPORTS_MBUFQ;
19533 		} else {
19534 			rack->r_mbuf_queue = 0;
19535 			rack->rc_inp->inp_flags2 &= ~INP_SUPPORTS_MBUFQ;
19536 		}
19537 		if (rack_enable_shared_cwnd)
19538 			rack->rack_enable_scwnd = 1;
19539 		else
19540 			rack->rack_enable_scwnd = 0;
19541 		if (rack_do_dyn_mul) {
19542 			/* When dynamic adjustment is on CA needs to start at 100% */
19543 			rack->rc_gp_dyn_mul = 1;
19544 			if (rack_do_dyn_mul >= 100)
19545 				rack->r_ctl.rack_per_of_gp_ca = rack_do_dyn_mul;
19546 		} else {
19547 			rack->r_ctl.rack_per_of_gp_ca = rack_per_of_gp_ca;
19548 			rack->rc_gp_dyn_mul = 0;
19549 		}
19550 		rack->r_rr_config = 0;
19551 		rack->r_ctl.rc_no_push_at_mrtt = 0;
19552 		rack->rc_pace_to_cwnd = 0;
19553 		rack->rc_pace_fill_if_rttin_range = 0;
19554 		rack->rtt_limit_mul = 0;
19555 
19556 		if (rack_enable_hw_pacing)
19557 			rack->rack_hdw_pace_ena = 1;
19558 		else
19559 			rack->rack_hdw_pace_ena = 0;
19560 		if (rack_disable_prr)
19561 			rack->rack_no_prr = 1;
19562 		else
19563 			rack->rack_no_prr = 0;
19564 		if (rack_limits_scwnd)
19565 			rack->r_limit_scw  = 1;
19566 		else
19567 			rack->r_limit_scw  = 0;
19568 		err = 0;
19569 	}
19570 	return (err);
19571 }
19572 
19573 static int
19574 rack_add_deferred_option(struct tcp_rack *rack, int sopt_name, uint64_t loptval)
19575 {
19576 	struct deferred_opt_list *dol;
19577 
19578 	dol = malloc(sizeof(struct deferred_opt_list),
19579 		     M_TCPFSB, M_NOWAIT|M_ZERO);
19580 	if (dol == NULL) {
19581 		/*
19582 		 * No space yikes -- fail out..
19583 		 */
19584 		return (0);
19585 	}
19586 	dol->optname = sopt_name;
19587 	dol->optval = loptval;
19588 	TAILQ_INSERT_TAIL(&rack->r_ctl.opt_list, dol, next);
19589 	return (1);
19590 }
19591 
19592 static int
19593 rack_process_option(struct tcpcb *tp, struct tcp_rack *rack, int sopt_name,
19594 		    uint32_t optval, uint64_t loptval)
19595 {
19596 	struct epoch_tracker et;
19597 	struct sockopt sopt;
19598 	struct cc_newreno_opts opt;
19599 	uint64_t val;
19600 	int error = 0;
19601 	uint16_t ca, ss;
19602 
19603 	switch (sopt_name) {
19604 
19605 	case TCP_RACK_DSACK_OPT:
19606 		RACK_OPTS_INC(tcp_rack_dsack_opt);
19607 		if (optval & 0x1) {
19608 			rack->rc_rack_tmr_std_based = 1;
19609 		} else {
19610 			rack->rc_rack_tmr_std_based = 0;
19611 		}
19612 		if (optval & 0x2) {
19613 			rack->rc_rack_use_dsack = 1;
19614 		} else {
19615 			rack->rc_rack_use_dsack = 0;
19616 		}
19617 		rack_log_dsack_event(rack, 5, __LINE__, 0, 0);
19618 		break;
19619 	case TCP_RACK_PACING_BETA:
19620 		RACK_OPTS_INC(tcp_rack_beta);
19621 		if (strcmp(tp->cc_algo->name, CCALGONAME_NEWRENO) != 0) {
19622 			/* This only works for newreno. */
19623 			error = EINVAL;
19624 			break;
19625 		}
19626 		if (rack->rc_pacing_cc_set) {
19627 			/*
19628 			 * Set them into the real CC module
19629 			 * whats in the rack pcb is the old values
19630 			 * to be used on restoral/
19631 			 */
19632 			sopt.sopt_dir = SOPT_SET;
19633 			opt.name = CC_NEWRENO_BETA;
19634 			opt.val = optval;
19635 			if (CC_ALGO(tp)->ctl_output != NULL)
19636 				error = CC_ALGO(tp)->ctl_output(tp->ccv, &sopt, &opt);
19637 			else {
19638 				error = ENOENT;
19639 				break;
19640 			}
19641 		} else {
19642 			/*
19643 			 * Not pacing yet so set it into our local
19644 			 * rack pcb storage.
19645 			 */
19646 			rack->r_ctl.rc_saved_beta.beta = optval;
19647 		}
19648 		break;
19649 	case TCP_RACK_TIMER_SLOP:
19650 		RACK_OPTS_INC(tcp_rack_timer_slop);
19651 		rack->r_ctl.timer_slop = optval;
19652 		if (rack->rc_tp->t_srtt) {
19653 			/*
19654 			 * If we have an SRTT lets update t_rxtcur
19655 			 * to have the new slop.
19656 			 */
19657 			RACK_TCPT_RANGESET(tp->t_rxtcur, RACK_REXMTVAL(tp),
19658 					   rack_rto_min, rack_rto_max,
19659 					   rack->r_ctl.timer_slop);
19660 		}
19661 		break;
19662 	case TCP_RACK_PACING_BETA_ECN:
19663 		RACK_OPTS_INC(tcp_rack_beta_ecn);
19664 		if (strcmp(tp->cc_algo->name, CCALGONAME_NEWRENO) != 0) {
19665 			/* This only works for newreno. */
19666 			error = EINVAL;
19667 			break;
19668 		}
19669 		if (rack->rc_pacing_cc_set) {
19670 			/*
19671 			 * Set them into the real CC module
19672 			 * whats in the rack pcb is the old values
19673 			 * to be used on restoral/
19674 			 */
19675 			sopt.sopt_dir = SOPT_SET;
19676 			opt.name = CC_NEWRENO_BETA_ECN;
19677 			opt.val = optval;
19678 			if (CC_ALGO(tp)->ctl_output != NULL)
19679 				error = CC_ALGO(tp)->ctl_output(tp->ccv, &sopt, &opt);
19680 			else
19681 				error = ENOENT;
19682 		} else {
19683 			/*
19684 			 * Not pacing yet so set it into our local
19685 			 * rack pcb storage.
19686 			 */
19687 			rack->r_ctl.rc_saved_beta.beta_ecn = optval;
19688 			rack->r_ctl.rc_saved_beta.newreno_flags = CC_NEWRENO_BETA_ECN_ENABLED;
19689 		}
19690 		break;
19691 	case TCP_DEFER_OPTIONS:
19692 		RACK_OPTS_INC(tcp_defer_opt);
19693 		if (optval) {
19694 			if (rack->gp_ready) {
19695 				/* Too late */
19696 				error = EINVAL;
19697 				break;
19698 			}
19699 			rack->defer_options = 1;
19700 		} else
19701 			rack->defer_options = 0;
19702 		break;
19703 	case TCP_RACK_MEASURE_CNT:
19704 		RACK_OPTS_INC(tcp_rack_measure_cnt);
19705 		if (optval && (optval <= 0xff)) {
19706 			rack->r_ctl.req_measurements = optval;
19707 		} else
19708 			error = EINVAL;
19709 		break;
19710 	case TCP_REC_ABC_VAL:
19711 		RACK_OPTS_INC(tcp_rec_abc_val);
19712 		if (optval > 0)
19713 			rack->r_use_labc_for_rec = 1;
19714 		else
19715 			rack->r_use_labc_for_rec = 0;
19716 		break;
19717 	case TCP_RACK_ABC_VAL:
19718 		RACK_OPTS_INC(tcp_rack_abc_val);
19719 		if ((optval > 0) && (optval < 255))
19720 			rack->rc_labc = optval;
19721 		else
19722 			error = EINVAL;
19723 		break;
19724 	case TCP_HDWR_UP_ONLY:
19725 		RACK_OPTS_INC(tcp_pacing_up_only);
19726 		if (optval)
19727 			rack->r_up_only = 1;
19728 		else
19729 			rack->r_up_only = 0;
19730 		break;
19731 	case TCP_PACING_RATE_CAP:
19732 		RACK_OPTS_INC(tcp_pacing_rate_cap);
19733 		rack->r_ctl.bw_rate_cap = loptval;
19734 		break;
19735 	case TCP_RACK_PROFILE:
19736 		RACK_OPTS_INC(tcp_profile);
19737 		error = rack_set_profile(rack, optval);
19738 		break;
19739 	case TCP_USE_CMP_ACKS:
19740 		RACK_OPTS_INC(tcp_use_cmp_acks);
19741 		if ((optval == 0) && (rack->rc_inp->inp_flags2 & INP_MBUF_ACKCMP)) {
19742 			/* You can't turn it off once its on! */
19743 			error = EINVAL;
19744 		} else if ((optval == 1) && (rack->r_use_cmp_ack == 0)) {
19745 			rack->r_use_cmp_ack = 1;
19746 			rack->r_mbuf_queue = 1;
19747 			tp->t_inpcb->inp_flags2 |= INP_SUPPORTS_MBUFQ;
19748 		}
19749 		if (rack->r_use_cmp_ack && TCPS_HAVEESTABLISHED(tp->t_state))
19750 			rack->rc_inp->inp_flags2 |= INP_MBUF_ACKCMP;
19751 		break;
19752 	case TCP_SHARED_CWND_TIME_LIMIT:
19753 		RACK_OPTS_INC(tcp_lscwnd);
19754 		if (optval)
19755 			rack->r_limit_scw = 1;
19756 		else
19757 			rack->r_limit_scw = 0;
19758 		break;
19759  	case TCP_RACK_PACE_TO_FILL:
19760 		RACK_OPTS_INC(tcp_fillcw);
19761 		if (optval == 0)
19762 			rack->rc_pace_to_cwnd = 0;
19763 		else {
19764 			rack->rc_pace_to_cwnd = 1;
19765 			if (optval > 1)
19766 				rack->r_fill_less_agg = 1;
19767 		}
19768 		if ((optval >= rack_gp_rtt_maxmul) &&
19769 		    rack_gp_rtt_maxmul &&
19770 		    (optval < 0xf)) {
19771 			rack->rc_pace_fill_if_rttin_range = 1;
19772 			rack->rtt_limit_mul = optval;
19773 		} else {
19774 			rack->rc_pace_fill_if_rttin_range = 0;
19775 			rack->rtt_limit_mul = 0;
19776 		}
19777 		break;
19778 	case TCP_RACK_NO_PUSH_AT_MAX:
19779 		RACK_OPTS_INC(tcp_npush);
19780 		if (optval == 0)
19781 			rack->r_ctl.rc_no_push_at_mrtt = 0;
19782 		else if (optval < 0xff)
19783 			rack->r_ctl.rc_no_push_at_mrtt = optval;
19784 		else
19785 			error = EINVAL;
19786 		break;
19787 	case TCP_SHARED_CWND_ENABLE:
19788 		RACK_OPTS_INC(tcp_rack_scwnd);
19789 		if (optval == 0)
19790 			rack->rack_enable_scwnd = 0;
19791 		else
19792 			rack->rack_enable_scwnd = 1;
19793 		break;
19794 	case TCP_RACK_MBUF_QUEUE:
19795 		/* Now do we use the LRO mbuf-queue feature */
19796 		RACK_OPTS_INC(tcp_rack_mbufq);
19797 		if (optval || rack->r_use_cmp_ack)
19798 			rack->r_mbuf_queue = 1;
19799 		else
19800 			rack->r_mbuf_queue = 0;
19801 		if  (rack->r_mbuf_queue || rack->rc_always_pace || rack->r_use_cmp_ack)
19802 			tp->t_inpcb->inp_flags2 |= INP_SUPPORTS_MBUFQ;
19803 		else
19804 			tp->t_inpcb->inp_flags2 &= ~INP_SUPPORTS_MBUFQ;
19805 		break;
19806 	case TCP_RACK_NONRXT_CFG_RATE:
19807 		RACK_OPTS_INC(tcp_rack_cfg_rate);
19808 		if (optval == 0)
19809 			rack->rack_rec_nonrxt_use_cr = 0;
19810 		else
19811 			rack->rack_rec_nonrxt_use_cr = 1;
19812 		break;
19813 	case TCP_NO_PRR:
19814 		RACK_OPTS_INC(tcp_rack_noprr);
19815 		if (optval == 0)
19816 			rack->rack_no_prr = 0;
19817 		else if (optval == 1)
19818 			rack->rack_no_prr = 1;
19819 		else if (optval == 2)
19820 			rack->no_prr_addback = 1;
19821 		else
19822 			error = EINVAL;
19823 		break;
19824 	case TCP_TIMELY_DYN_ADJ:
19825 		RACK_OPTS_INC(tcp_timely_dyn);
19826 		if (optval == 0)
19827 			rack->rc_gp_dyn_mul = 0;
19828 		else {
19829 			rack->rc_gp_dyn_mul = 1;
19830 			if (optval >= 100) {
19831 				/*
19832 				 * If the user sets something 100 or more
19833 				 * its the gp_ca value.
19834 				 */
19835 				rack->r_ctl.rack_per_of_gp_ca  = optval;
19836 			}
19837 		}
19838 		break;
19839 	case TCP_RACK_DO_DETECTION:
19840 		RACK_OPTS_INC(tcp_rack_do_detection);
19841 		if (optval == 0)
19842 			rack->do_detection = 0;
19843 		else
19844 			rack->do_detection = 1;
19845 		break;
19846 	case TCP_RACK_TLP_USE:
19847 		if ((optval < TLP_USE_ID) || (optval > TLP_USE_TWO_TWO)) {
19848 			error = EINVAL;
19849 			break;
19850 		}
19851 		RACK_OPTS_INC(tcp_tlp_use);
19852 		rack->rack_tlp_threshold_use = optval;
19853 		break;
19854 	case TCP_RACK_TLP_REDUCE:
19855 		/* RACK TLP cwnd reduction (bool) */
19856 		RACK_OPTS_INC(tcp_rack_tlp_reduce);
19857 		rack->r_ctl.rc_tlp_cwnd_reduce = optval;
19858 		break;
19859 	/*  Pacing related ones */
19860 	case TCP_RACK_PACE_ALWAYS:
19861 		/*
19862 		 * zero is old rack method, 1 is new
19863 		 * method using a pacing rate.
19864 		 */
19865 		RACK_OPTS_INC(tcp_rack_pace_always);
19866 		if (optval > 0) {
19867 			if (rack->rc_always_pace) {
19868 				error = EALREADY;
19869 				break;
19870 			} else if (tcp_can_enable_pacing()) {
19871 				rack->rc_always_pace = 1;
19872 				if (rack->use_fixed_rate || rack->gp_ready)
19873 					rack_set_cc_pacing(rack);
19874 			}
19875 			else {
19876 				error = ENOSPC;
19877 				break;
19878 			}
19879 		} else {
19880 			if (rack->rc_always_pace) {
19881 				tcp_decrement_paced_conn();
19882 				rack->rc_always_pace = 0;
19883 				rack_undo_cc_pacing(rack);
19884 			}
19885 		}
19886 		if  (rack->r_mbuf_queue || rack->rc_always_pace || rack->r_use_cmp_ack)
19887 			tp->t_inpcb->inp_flags2 |= INP_SUPPORTS_MBUFQ;
19888 		else
19889 			tp->t_inpcb->inp_flags2 &= ~INP_SUPPORTS_MBUFQ;
19890 		/* A rate may be set irate or other, if so set seg size */
19891 		rack_update_seg(rack);
19892 		break;
19893 	case TCP_BBR_RACK_INIT_RATE:
19894 		RACK_OPTS_INC(tcp_initial_rate);
19895 		val = optval;
19896 		/* Change from kbits per second to bytes per second */
19897 		val *= 1000;
19898 		val /= 8;
19899 		rack->r_ctl.init_rate = val;
19900 		if (rack->rc_init_win != rack_default_init_window) {
19901 			uint32_t win, snt;
19902 
19903 			/*
19904 			 * Options don't always get applied
19905 			 * in the order you think. So in order
19906 			 * to assure we update a cwnd we need
19907 			 * to check and see if we are still
19908 			 * where we should raise the cwnd.
19909 			 */
19910 			win = rc_init_window(rack);
19911 			if (SEQ_GT(tp->snd_max, tp->iss))
19912 				snt = tp->snd_max - tp->iss;
19913 			else
19914 				snt = 0;
19915 			if ((snt < win) &&
19916 			    (tp->snd_cwnd < win))
19917 				tp->snd_cwnd = win;
19918 		}
19919 		if (rack->rc_always_pace)
19920 			rack_update_seg(rack);
19921 		break;
19922 	case TCP_BBR_IWINTSO:
19923 		RACK_OPTS_INC(tcp_initial_win);
19924 		if (optval && (optval <= 0xff)) {
19925 			uint32_t win, snt;
19926 
19927 			rack->rc_init_win = optval;
19928 			win = rc_init_window(rack);
19929 			if (SEQ_GT(tp->snd_max, tp->iss))
19930 				snt = tp->snd_max - tp->iss;
19931 			else
19932 				snt = 0;
19933 			if ((snt < win) &&
19934 			    (tp->t_srtt |
19935 #ifdef NETFLIX_PEAKRATE
19936 			     tp->t_maxpeakrate |
19937 #endif
19938 			     rack->r_ctl.init_rate)) {
19939 				/*
19940 				 * We are not past the initial window
19941 				 * and we have some bases for pacing,
19942 				 * so we need to possibly adjust up
19943 				 * the cwnd. Note even if we don't set
19944 				 * the cwnd, its still ok to raise the rc_init_win
19945 				 * which can be used coming out of idle when we
19946 				 * would have a rate.
19947 				 */
19948 				if (tp->snd_cwnd < win)
19949 					tp->snd_cwnd = win;
19950 			}
19951 			if (rack->rc_always_pace)
19952 				rack_update_seg(rack);
19953 		} else
19954 			error = EINVAL;
19955 		break;
19956 	case TCP_RACK_FORCE_MSEG:
19957 		RACK_OPTS_INC(tcp_rack_force_max_seg);
19958 		if (optval)
19959 			rack->rc_force_max_seg = 1;
19960 		else
19961 			rack->rc_force_max_seg = 0;
19962 		break;
19963 	case TCP_RACK_PACE_MAX_SEG:
19964 		/* Max segments size in a pace in bytes */
19965 		RACK_OPTS_INC(tcp_rack_max_seg);
19966 		rack->rc_user_set_max_segs = optval;
19967 		rack_set_pace_segments(tp, rack, __LINE__, NULL);
19968 		break;
19969 	case TCP_RACK_PACE_RATE_REC:
19970 		/* Set the fixed pacing rate in Bytes per second ca */
19971 		RACK_OPTS_INC(tcp_rack_pace_rate_rec);
19972 		rack->r_ctl.rc_fixed_pacing_rate_rec = optval;
19973 		if (rack->r_ctl.rc_fixed_pacing_rate_ca == 0)
19974 			rack->r_ctl.rc_fixed_pacing_rate_ca = optval;
19975 		if (rack->r_ctl.rc_fixed_pacing_rate_ss == 0)
19976 			rack->r_ctl.rc_fixed_pacing_rate_ss = optval;
19977 		rack->use_fixed_rate = 1;
19978 		if (rack->rc_always_pace)
19979 			rack_set_cc_pacing(rack);
19980 		rack_log_pacing_delay_calc(rack,
19981 					   rack->r_ctl.rc_fixed_pacing_rate_ss,
19982 					   rack->r_ctl.rc_fixed_pacing_rate_ca,
19983 					   rack->r_ctl.rc_fixed_pacing_rate_rec, 0, 0, 8,
19984 					   __LINE__, NULL,0);
19985 		break;
19986 
19987 	case TCP_RACK_PACE_RATE_SS:
19988 		/* Set the fixed pacing rate in Bytes per second ca */
19989 		RACK_OPTS_INC(tcp_rack_pace_rate_ss);
19990 		rack->r_ctl.rc_fixed_pacing_rate_ss = optval;
19991 		if (rack->r_ctl.rc_fixed_pacing_rate_ca == 0)
19992 			rack->r_ctl.rc_fixed_pacing_rate_ca = optval;
19993 		if (rack->r_ctl.rc_fixed_pacing_rate_rec == 0)
19994 			rack->r_ctl.rc_fixed_pacing_rate_rec = optval;
19995 		rack->use_fixed_rate = 1;
19996 		if (rack->rc_always_pace)
19997 			rack_set_cc_pacing(rack);
19998 		rack_log_pacing_delay_calc(rack,
19999 					   rack->r_ctl.rc_fixed_pacing_rate_ss,
20000 					   rack->r_ctl.rc_fixed_pacing_rate_ca,
20001 					   rack->r_ctl.rc_fixed_pacing_rate_rec, 0, 0, 8,
20002 					   __LINE__, NULL, 0);
20003 		break;
20004 
20005 	case TCP_RACK_PACE_RATE_CA:
20006 		/* Set the fixed pacing rate in Bytes per second ca */
20007 		RACK_OPTS_INC(tcp_rack_pace_rate_ca);
20008 		rack->r_ctl.rc_fixed_pacing_rate_ca = optval;
20009 		if (rack->r_ctl.rc_fixed_pacing_rate_ss == 0)
20010 			rack->r_ctl.rc_fixed_pacing_rate_ss = optval;
20011 		if (rack->r_ctl.rc_fixed_pacing_rate_rec == 0)
20012 			rack->r_ctl.rc_fixed_pacing_rate_rec = optval;
20013 		rack->use_fixed_rate = 1;
20014 		if (rack->rc_always_pace)
20015 			rack_set_cc_pacing(rack);
20016 		rack_log_pacing_delay_calc(rack,
20017 					   rack->r_ctl.rc_fixed_pacing_rate_ss,
20018 					   rack->r_ctl.rc_fixed_pacing_rate_ca,
20019 					   rack->r_ctl.rc_fixed_pacing_rate_rec, 0, 0, 8,
20020 					   __LINE__, NULL, 0);
20021 		break;
20022 	case TCP_RACK_GP_INCREASE_REC:
20023 		RACK_OPTS_INC(tcp_gp_inc_rec);
20024 		rack->r_ctl.rack_per_of_gp_rec = optval;
20025 		rack_log_pacing_delay_calc(rack,
20026 					   rack->r_ctl.rack_per_of_gp_ss,
20027 					   rack->r_ctl.rack_per_of_gp_ca,
20028 					   rack->r_ctl.rack_per_of_gp_rec, 0, 0, 1,
20029 					   __LINE__, NULL, 0);
20030 		break;
20031 	case TCP_RACK_GP_INCREASE_CA:
20032 		RACK_OPTS_INC(tcp_gp_inc_ca);
20033 		ca = optval;
20034 		if (ca < 100) {
20035 			/*
20036 			 * We don't allow any reduction
20037 			 * over the GP b/w.
20038 			 */
20039 			error = EINVAL;
20040 			break;
20041 		}
20042 		rack->r_ctl.rack_per_of_gp_ca = ca;
20043 		rack_log_pacing_delay_calc(rack,
20044 					   rack->r_ctl.rack_per_of_gp_ss,
20045 					   rack->r_ctl.rack_per_of_gp_ca,
20046 					   rack->r_ctl.rack_per_of_gp_rec, 0, 0, 1,
20047 					   __LINE__, NULL, 0);
20048 		break;
20049 	case TCP_RACK_GP_INCREASE_SS:
20050 		RACK_OPTS_INC(tcp_gp_inc_ss);
20051 		ss = optval;
20052 		if (ss < 100) {
20053 			/*
20054 			 * We don't allow any reduction
20055 			 * over the GP b/w.
20056 			 */
20057 			error = EINVAL;
20058 			break;
20059 		}
20060 		rack->r_ctl.rack_per_of_gp_ss = ss;
20061 		rack_log_pacing_delay_calc(rack,
20062 					   rack->r_ctl.rack_per_of_gp_ss,
20063 					   rack->r_ctl.rack_per_of_gp_ca,
20064 					   rack->r_ctl.rack_per_of_gp_rec, 0, 0, 1,
20065 					   __LINE__, NULL, 0);
20066 		break;
20067 	case TCP_RACK_RR_CONF:
20068 		RACK_OPTS_INC(tcp_rack_rrr_no_conf_rate);
20069 		if (optval && optval <= 3)
20070 			rack->r_rr_config = optval;
20071 		else
20072 			rack->r_rr_config = 0;
20073 		break;
20074 	case TCP_HDWR_RATE_CAP:
20075 		RACK_OPTS_INC(tcp_hdwr_rate_cap);
20076 		if (optval) {
20077 			if (rack->r_rack_hw_rate_caps == 0)
20078 				rack->r_rack_hw_rate_caps = 1;
20079 			else
20080 				error = EALREADY;
20081 		} else {
20082 			rack->r_rack_hw_rate_caps = 0;
20083 		}
20084 		break;
20085 	case TCP_BBR_HDWR_PACE:
20086 		RACK_OPTS_INC(tcp_hdwr_pacing);
20087 		if (optval){
20088 			if (rack->rack_hdrw_pacing == 0) {
20089 				rack->rack_hdw_pace_ena = 1;
20090 				rack->rack_attempt_hdwr_pace = 0;
20091 			} else
20092 				error = EALREADY;
20093 		} else {
20094 			rack->rack_hdw_pace_ena = 0;
20095 #ifdef RATELIMIT
20096 			if (rack->r_ctl.crte != NULL) {
20097 				rack->rack_hdrw_pacing = 0;
20098 				rack->rack_attempt_hdwr_pace = 0;
20099 				tcp_rel_pacing_rate(rack->r_ctl.crte, tp);
20100 				rack->r_ctl.crte = NULL;
20101 			}
20102 #endif
20103 		}
20104 		break;
20105 	/*  End Pacing related ones */
20106 	case TCP_RACK_PRR_SENDALOT:
20107 		/* Allow PRR to send more than one seg */
20108 		RACK_OPTS_INC(tcp_rack_prr_sendalot);
20109 		rack->r_ctl.rc_prr_sendalot = optval;
20110 		break;
20111 	case TCP_RACK_MIN_TO:
20112 		/* Minimum time between rack t-o's in ms */
20113 		RACK_OPTS_INC(tcp_rack_min_to);
20114 		rack->r_ctl.rc_min_to = optval;
20115 		break;
20116 	case TCP_RACK_EARLY_SEG:
20117 		/* If early recovery max segments */
20118 		RACK_OPTS_INC(tcp_rack_early_seg);
20119 		rack->r_ctl.rc_early_recovery_segs = optval;
20120 		break;
20121 	case TCP_RACK_ENABLE_HYSTART:
20122 	{
20123 		struct sockopt sopt;
20124 		struct cc_newreno_opts opt;
20125 
20126 		sopt.sopt_valsize = sizeof(struct cc_newreno_opts);
20127 		sopt.sopt_dir = SOPT_SET;
20128 		opt.name = CC_NEWRENO_ENABLE_HYSTART;
20129 		opt.val = optval;
20130 		if (CC_ALGO(tp)->ctl_output != NULL)
20131 			error = CC_ALGO(tp)->ctl_output(tp->ccv, &sopt, &opt);
20132 		else
20133 			error = EINVAL;
20134 	}
20135 	break;
20136 	case TCP_RACK_REORD_THRESH:
20137 		/* RACK reorder threshold (shift amount) */
20138 		RACK_OPTS_INC(tcp_rack_reord_thresh);
20139 		if ((optval > 0) && (optval < 31))
20140 			rack->r_ctl.rc_reorder_shift = optval;
20141 		else
20142 			error = EINVAL;
20143 		break;
20144 	case TCP_RACK_REORD_FADE:
20145 		/* Does reordering fade after ms time */
20146 		RACK_OPTS_INC(tcp_rack_reord_fade);
20147 		rack->r_ctl.rc_reorder_fade = optval;
20148 		break;
20149 	case TCP_RACK_TLP_THRESH:
20150 		/* RACK TLP theshold i.e. srtt+(srtt/N) */
20151 		RACK_OPTS_INC(tcp_rack_tlp_thresh);
20152 		if (optval)
20153 			rack->r_ctl.rc_tlp_threshold = optval;
20154 		else
20155 			error = EINVAL;
20156 		break;
20157 	case TCP_BBR_USE_RACK_RR:
20158 		RACK_OPTS_INC(tcp_rack_rr);
20159 		if (optval)
20160 			rack->use_rack_rr = 1;
20161 		else
20162 			rack->use_rack_rr = 0;
20163 		break;
20164 	case TCP_FAST_RSM_HACK:
20165 		RACK_OPTS_INC(tcp_rack_fastrsm_hack);
20166 		if (optval)
20167 			rack->fast_rsm_hack = 1;
20168 		else
20169 			rack->fast_rsm_hack = 0;
20170 		break;
20171 	case TCP_RACK_PKT_DELAY:
20172 		/* RACK added ms i.e. rack-rtt + reord + N */
20173 		RACK_OPTS_INC(tcp_rack_pkt_delay);
20174 		rack->r_ctl.rc_pkt_delay = optval;
20175 		break;
20176 	case TCP_DELACK:
20177 		RACK_OPTS_INC(tcp_rack_delayed_ack);
20178 		if (optval == 0)
20179 			tp->t_delayed_ack = 0;
20180 		else
20181 			tp->t_delayed_ack = 1;
20182 		if (tp->t_flags & TF_DELACK) {
20183 			tp->t_flags &= ~TF_DELACK;
20184 			tp->t_flags |= TF_ACKNOW;
20185 			NET_EPOCH_ENTER(et);
20186 			rack_output(tp);
20187 			NET_EPOCH_EXIT(et);
20188 		}
20189 		break;
20190 
20191 	case TCP_BBR_RACK_RTT_USE:
20192 		RACK_OPTS_INC(tcp_rack_rtt_use);
20193 		if ((optval != USE_RTT_HIGH) &&
20194 		    (optval != USE_RTT_LOW) &&
20195 		    (optval != USE_RTT_AVG))
20196 			error = EINVAL;
20197 		else
20198 			rack->r_ctl.rc_rate_sample_method = optval;
20199 		break;
20200 	case TCP_DATA_AFTER_CLOSE:
20201 		RACK_OPTS_INC(tcp_data_after_close);
20202 		if (optval)
20203 			rack->rc_allow_data_af_clo = 1;
20204 		else
20205 			rack->rc_allow_data_af_clo = 0;
20206 		break;
20207 	default:
20208 		break;
20209 	}
20210 #ifdef NETFLIX_STATS
20211 	tcp_log_socket_option(tp, sopt_name, optval, error);
20212 #endif
20213 	return (error);
20214 }
20215 
20216 
20217 static void
20218 rack_apply_deferred_options(struct tcp_rack *rack)
20219 {
20220 	struct deferred_opt_list *dol, *sdol;
20221 	uint32_t s_optval;
20222 
20223 	TAILQ_FOREACH_SAFE(dol, &rack->r_ctl.opt_list, next, sdol) {
20224 		TAILQ_REMOVE(&rack->r_ctl.opt_list, dol, next);
20225 		/* Disadvantage of deferal is you loose the error return */
20226 		s_optval = (uint32_t)dol->optval;
20227 		(void)rack_process_option(rack->rc_tp, rack, dol->optname, s_optval, dol->optval);
20228 		free(dol, M_TCPDO);
20229 	}
20230 }
20231 
20232 static void
20233 rack_hw_tls_change(struct tcpcb *tp, int chg)
20234 {
20235 	/*
20236 	 * HW tls state has changed.. fix all
20237 	 * rsm's in flight.
20238 	 */
20239 	struct tcp_rack *rack;
20240 	struct rack_sendmap *rsm;
20241 
20242 	rack = (struct tcp_rack *)tp->t_fb_ptr;
20243 	RB_FOREACH(rsm, rack_rb_tree_head, &rack->r_ctl.rc_mtree) {
20244 		if (chg)
20245 			rsm->r_hw_tls = 1;
20246 		else
20247 			rsm->r_hw_tls = 0;
20248 	}
20249 	if (chg)
20250 		rack->r_ctl.fsb.hw_tls = 1;
20251 	else
20252 		rack->r_ctl.fsb.hw_tls = 0;
20253 }
20254 
20255 static int
20256 rack_pru_options(struct tcpcb *tp, int flags)
20257 {
20258 	if (flags & PRUS_OOB)
20259 		return (EOPNOTSUPP);
20260 	return (0);
20261 }
20262 
20263 static struct tcp_function_block __tcp_rack = {
20264 	.tfb_tcp_block_name = __XSTRING(STACKNAME),
20265 	.tfb_tcp_output = rack_output,
20266 	.tfb_do_queued_segments = ctf_do_queued_segments,
20267 	.tfb_do_segment_nounlock = rack_do_segment_nounlock,
20268 	.tfb_tcp_do_segment = rack_do_segment,
20269 	.tfb_tcp_ctloutput = rack_ctloutput,
20270 	.tfb_tcp_fb_init = rack_init,
20271 	.tfb_tcp_fb_fini = rack_fini,
20272 	.tfb_tcp_timer_stop_all = rack_stopall,
20273 	.tfb_tcp_timer_activate = rack_timer_activate,
20274 	.tfb_tcp_timer_active = rack_timer_active,
20275 	.tfb_tcp_timer_stop = rack_timer_stop,
20276 	.tfb_tcp_rexmit_tmr = rack_remxt_tmr,
20277 	.tfb_tcp_handoff_ok = rack_handoff_ok,
20278 	.tfb_tcp_mtu_chg = rack_mtu_change,
20279 	.tfb_pru_options = rack_pru_options,
20280 	.tfb_hwtls_change = rack_hw_tls_change,
20281 };
20282 
20283 /*
20284  * rack_ctloutput() must drop the inpcb lock before performing copyin on
20285  * socket option arguments.  When it re-acquires the lock after the copy, it
20286  * has to revalidate that the connection is still valid for the socket
20287  * option.
20288  */
20289 static int
20290 rack_set_sockopt(struct socket *so, struct sockopt *sopt,
20291     struct inpcb *inp, struct tcpcb *tp, struct tcp_rack *rack)
20292 {
20293 #ifdef INET6
20294 	struct ip6_hdr *ip6 = (struct ip6_hdr *)rack->r_ctl.fsb.tcp_ip_hdr;
20295 #endif
20296 #ifdef INET
20297 	struct ip *ip = (struct ip *)rack->r_ctl.fsb.tcp_ip_hdr;
20298 #endif
20299 	uint64_t loptval;
20300 	int32_t error = 0, optval;
20301 
20302 	switch (sopt->sopt_level) {
20303 #ifdef INET6
20304 	case IPPROTO_IPV6:
20305 		MPASS(inp->inp_vflag & INP_IPV6PROTO);
20306 		switch (sopt->sopt_name) {
20307 		case IPV6_USE_MIN_MTU:
20308 			tcp6_use_min_mtu(tp);
20309 			break;
20310 		case IPV6_TCLASS:
20311 			/*
20312 			 * The DSCP codepoint has changed, update the fsb.
20313 			 */
20314 			ip6->ip6_flow = (ip6->ip6_flow & ~IPV6_FLOWINFO_MASK) |
20315 			    (rack->rc_inp->inp_flow & IPV6_FLOWINFO_MASK);
20316 			break;
20317 		}
20318 		INP_WUNLOCK(inp);
20319 		return (0);
20320 #endif
20321 #ifdef INET
20322 	case IPPROTO_IP:
20323 		switch (sopt->sopt_name) {
20324 		case IP_TOS:
20325 			/*
20326 			 * The DSCP codepoint has changed, update the fsb.
20327 			 */
20328 			ip->ip_tos = rack->rc_inp->inp_ip_tos;
20329 			break;
20330 		case IP_TTL:
20331 			/*
20332 			 * The TTL has changed, update the fsb.
20333 			 */
20334 			ip->ip_ttl = rack->rc_inp->inp_ip_ttl;
20335 			break;
20336 		}
20337 		INP_WUNLOCK(inp);
20338 		return (0);
20339 #endif
20340 	}
20341 
20342 	switch (sopt->sopt_name) {
20343 	case TCP_RACK_TLP_REDUCE:		/*  URL:tlp_reduce */
20344 	/*  Pacing related ones */
20345 	case TCP_RACK_PACE_ALWAYS:		/*  URL:pace_always */
20346 	case TCP_BBR_RACK_INIT_RATE:		/*  URL:irate */
20347 	case TCP_BBR_IWINTSO:			/*  URL:tso_iwin */
20348 	case TCP_RACK_PACE_MAX_SEG:		/*  URL:pace_max_seg */
20349 	case TCP_RACK_FORCE_MSEG:		/*  URL:force_max_seg */
20350 	case TCP_RACK_PACE_RATE_CA:		/*  URL:pr_ca */
20351 	case TCP_RACK_PACE_RATE_SS:		/*  URL:pr_ss*/
20352 	case TCP_RACK_PACE_RATE_REC:		/*  URL:pr_rec */
20353 	case TCP_RACK_GP_INCREASE_CA:		/*  URL:gp_inc_ca */
20354 	case TCP_RACK_GP_INCREASE_SS:		/*  URL:gp_inc_ss */
20355 	case TCP_RACK_GP_INCREASE_REC:		/*  URL:gp_inc_rec */
20356 	case TCP_RACK_RR_CONF:			/*  URL:rrr_conf */
20357 	case TCP_BBR_HDWR_PACE:			/*  URL:hdwrpace */
20358 	case TCP_HDWR_RATE_CAP:			/*  URL:hdwrcap boolean */
20359 	case TCP_PACING_RATE_CAP:		/*  URL:cap  -- used by side-channel */
20360 	case TCP_HDWR_UP_ONLY:			/*  URL:uponly -- hardware pacing  boolean */
20361        /* End pacing related */
20362 	case TCP_FAST_RSM_HACK:			/*  URL:frsm_hack */
20363 	case TCP_DELACK:			/*  URL:delack (in base TCP i.e. tcp_hints along with cc etc ) */
20364 	case TCP_RACK_PRR_SENDALOT:		/*  URL:prr_sendalot */
20365 	case TCP_RACK_MIN_TO:			/*  URL:min_to */
20366 	case TCP_RACK_EARLY_SEG:		/*  URL:early_seg */
20367 	case TCP_RACK_REORD_THRESH:		/*  URL:reord_thresh */
20368 	case TCP_RACK_REORD_FADE:		/*  URL:reord_fade */
20369 	case TCP_RACK_TLP_THRESH:		/*  URL:tlp_thresh */
20370 	case TCP_RACK_PKT_DELAY:		/*  URL:pkt_delay */
20371 	case TCP_RACK_TLP_USE:			/*  URL:tlp_use */
20372 	case TCP_BBR_RACK_RTT_USE:		/*  URL:rttuse */
20373 	case TCP_BBR_USE_RACK_RR:		/*  URL:rackrr */
20374 	case TCP_RACK_DO_DETECTION:		/*  URL:detect */
20375 	case TCP_NO_PRR:			/*  URL:noprr */
20376 	case TCP_TIMELY_DYN_ADJ:      		/*  URL:dynamic */
20377 	case TCP_DATA_AFTER_CLOSE:		/*  no URL */
20378 	case TCP_RACK_NONRXT_CFG_RATE:		/*  URL:nonrxtcr */
20379 	case TCP_SHARED_CWND_ENABLE:		/*  URL:scwnd */
20380 	case TCP_RACK_MBUF_QUEUE:		/*  URL:mqueue */
20381 	case TCP_RACK_NO_PUSH_AT_MAX:		/*  URL:npush */
20382 	case TCP_RACK_PACE_TO_FILL:		/*  URL:fillcw */
20383 	case TCP_SHARED_CWND_TIME_LIMIT:	/*  URL:lscwnd */
20384 	case TCP_RACK_PROFILE:			/*  URL:profile */
20385 	case TCP_USE_CMP_ACKS:			/*  URL:cmpack */
20386 	case TCP_RACK_ABC_VAL:			/*  URL:labc */
20387 	case TCP_REC_ABC_VAL:			/*  URL:reclabc */
20388 	case TCP_RACK_MEASURE_CNT:		/*  URL:measurecnt */
20389 	case TCP_DEFER_OPTIONS:			/*  URL:defer */
20390 	case TCP_RACK_DSACK_OPT:		/*  URL:dsack */
20391 	case TCP_RACK_PACING_BETA:		/*  URL:pacing_beta */
20392 	case TCP_RACK_PACING_BETA_ECN:		/*  URL:pacing_beta_ecn */
20393 	case TCP_RACK_TIMER_SLOP:		/*  URL:timer_slop */
20394 	case TCP_RACK_ENABLE_HYSTART:		/*  URL:hystart */
20395 		break;
20396 	default:
20397 		/* Filter off all unknown options to the base stack */
20398 		return (tcp_default_ctloutput(so, sopt, inp, tp));
20399 		break;
20400 	}
20401 	INP_WUNLOCK(inp);
20402 	if (sopt->sopt_name == TCP_PACING_RATE_CAP) {
20403 		error = sooptcopyin(sopt, &loptval, sizeof(loptval), sizeof(loptval));
20404 		/*
20405 		 * We truncate it down to 32 bits for the socket-option trace this
20406 		 * means rates > 34Gbps won't show right, but thats probably ok.
20407 		 */
20408 		optval = (uint32_t)loptval;
20409 	} else {
20410 		error = sooptcopyin(sopt, &optval, sizeof(optval), sizeof(optval));
20411 		/* Save it in 64 bit form too */
20412 		loptval = optval;
20413 	}
20414 	if (error)
20415 		return (error);
20416 	INP_WLOCK(inp);
20417 	if (inp->inp_flags & (INP_TIMEWAIT | INP_DROPPED)) {
20418 		INP_WUNLOCK(inp);
20419 		return (ECONNRESET);
20420 	}
20421 	if (tp->t_fb != &__tcp_rack) {
20422 		INP_WUNLOCK(inp);
20423 		return (ENOPROTOOPT);
20424 	}
20425 	if (rack->defer_options && (rack->gp_ready == 0) &&
20426 	    (sopt->sopt_name != TCP_DEFER_OPTIONS) &&
20427 	    (sopt->sopt_name != TCP_RACK_PACING_BETA) &&
20428 	    (sopt->sopt_name != TCP_RACK_PACING_BETA_ECN) &&
20429 	    (sopt->sopt_name != TCP_RACK_MEASURE_CNT)) {
20430 		/* Options are beind deferred */
20431 		if (rack_add_deferred_option(rack, sopt->sopt_name, loptval)) {
20432 			INP_WUNLOCK(inp);
20433 			return (0);
20434 		} else {
20435 			/* No memory to defer, fail */
20436 			INP_WUNLOCK(inp);
20437 			return (ENOMEM);
20438 		}
20439 	}
20440 	error = rack_process_option(tp, rack, sopt->sopt_name, optval, loptval);
20441 	INP_WUNLOCK(inp);
20442 	return (error);
20443 }
20444 
20445 static void
20446 rack_fill_info(struct tcpcb *tp, struct tcp_info *ti)
20447 {
20448 
20449 	INP_WLOCK_ASSERT(tp->t_inpcb);
20450 	bzero(ti, sizeof(*ti));
20451 
20452 	ti->tcpi_state = tp->t_state;
20453 	if ((tp->t_flags & TF_REQ_TSTMP) && (tp->t_flags & TF_RCVD_TSTMP))
20454 		ti->tcpi_options |= TCPI_OPT_TIMESTAMPS;
20455 	if (tp->t_flags & TF_SACK_PERMIT)
20456 		ti->tcpi_options |= TCPI_OPT_SACK;
20457 	if ((tp->t_flags & TF_REQ_SCALE) && (tp->t_flags & TF_RCVD_SCALE)) {
20458 		ti->tcpi_options |= TCPI_OPT_WSCALE;
20459 		ti->tcpi_snd_wscale = tp->snd_scale;
20460 		ti->tcpi_rcv_wscale = tp->rcv_scale;
20461 	}
20462 	if (tp->t_flags2 & TF2_ECN_PERMIT)
20463 		ti->tcpi_options |= TCPI_OPT_ECN;
20464 	if (tp->t_flags & TF_FASTOPEN)
20465 		ti->tcpi_options |= TCPI_OPT_TFO;
20466 	/* still kept in ticks is t_rcvtime */
20467 	ti->tcpi_last_data_recv = ((uint32_t)ticks - tp->t_rcvtime) * tick;
20468 	/* Since we hold everything in precise useconds this is easy */
20469 	ti->tcpi_rtt = tp->t_srtt;
20470 	ti->tcpi_rttvar = tp->t_rttvar;
20471 	ti->tcpi_rto = tp->t_rxtcur;
20472 	ti->tcpi_snd_ssthresh = tp->snd_ssthresh;
20473 	ti->tcpi_snd_cwnd = tp->snd_cwnd;
20474 	/*
20475 	 * FreeBSD-specific extension fields for tcp_info.
20476 	 */
20477 	ti->tcpi_rcv_space = tp->rcv_wnd;
20478 	ti->tcpi_rcv_nxt = tp->rcv_nxt;
20479 	ti->tcpi_snd_wnd = tp->snd_wnd;
20480 	ti->tcpi_snd_bwnd = 0;		/* Unused, kept for compat. */
20481 	ti->tcpi_snd_nxt = tp->snd_nxt;
20482 	ti->tcpi_snd_mss = tp->t_maxseg;
20483 	ti->tcpi_rcv_mss = tp->t_maxseg;
20484 	ti->tcpi_snd_rexmitpack = tp->t_sndrexmitpack;
20485 	ti->tcpi_rcv_ooopack = tp->t_rcvoopack;
20486 	ti->tcpi_snd_zerowin = tp->t_sndzerowin;
20487 #ifdef NETFLIX_STATS
20488 	ti->tcpi_total_tlp = tp->t_sndtlppack;
20489 	ti->tcpi_total_tlp_bytes = tp->t_sndtlpbyte;
20490 	memcpy(&ti->tcpi_rxsyninfo, &tp->t_rxsyninfo, sizeof(struct tcpsyninfo));
20491 #endif
20492 #ifdef TCP_OFFLOAD
20493 	if (tp->t_flags & TF_TOE) {
20494 		ti->tcpi_options |= TCPI_OPT_TOE;
20495 		tcp_offload_tcp_info(tp, ti);
20496 	}
20497 #endif
20498 }
20499 
20500 static int
20501 rack_get_sockopt(struct socket *so, struct sockopt *sopt,
20502     struct inpcb *inp, struct tcpcb *tp, struct tcp_rack *rack)
20503 {
20504 	int32_t error, optval;
20505 	uint64_t val, loptval;
20506 	struct	tcp_info ti;
20507 	/*
20508 	 * Because all our options are either boolean or an int, we can just
20509 	 * pull everything into optval and then unlock and copy. If we ever
20510 	 * add a option that is not a int, then this will have quite an
20511 	 * impact to this routine.
20512 	 */
20513 	error = 0;
20514 	switch (sopt->sopt_name) {
20515 	case TCP_INFO:
20516 		/* First get the info filled */
20517 		rack_fill_info(tp, &ti);
20518 		/* Fix up the rtt related fields if needed */
20519 		INP_WUNLOCK(inp);
20520 		error = sooptcopyout(sopt, &ti, sizeof ti);
20521 		return (error);
20522 	/*
20523 	 * Beta is the congestion control value for NewReno that influences how
20524 	 * much of a backoff happens when loss is detected. It is normally set
20525 	 * to 50 for 50% i.e. the cwnd is reduced to 50% of its previous value
20526 	 * when you exit recovery.
20527 	 */
20528 	case TCP_RACK_PACING_BETA:
20529 		if (strcmp(tp->cc_algo->name, CCALGONAME_NEWRENO) != 0)
20530 			error = EINVAL;
20531 		else if (rack->rc_pacing_cc_set == 0)
20532 			optval = rack->r_ctl.rc_saved_beta.beta;
20533 		else {
20534 			/*
20535 			 * Reach out into the CC data and report back what
20536 			 * I have previously set. Yeah it looks hackish but
20537 			 * we don't want to report the saved values.
20538 			 */
20539 			if (tp->ccv->cc_data)
20540 				optval = ((struct newreno *)tp->ccv->cc_data)->beta;
20541 			else
20542 				error = EINVAL;
20543 		}
20544 		break;
20545 		/*
20546 		 * Beta_ecn is the congestion control value for NewReno that influences how
20547 		 * much of a backoff happens when a ECN mark is detected. It is normally set
20548 		 * to 80 for 80% i.e. the cwnd is reduced by 20% of its previous value when
20549 		 * you exit recovery. Note that classic ECN has a beta of 50, it is only
20550 		 * ABE Ecn that uses this "less" value, but we do too with pacing :)
20551 		 */
20552 
20553 	case TCP_RACK_PACING_BETA_ECN:
20554 		if (strcmp(tp->cc_algo->name, CCALGONAME_NEWRENO) != 0)
20555 			error = EINVAL;
20556 		else if (rack->rc_pacing_cc_set == 0)
20557 			optval = rack->r_ctl.rc_saved_beta.beta_ecn;
20558 		else {
20559 			/*
20560 			 * Reach out into the CC data and report back what
20561 			 * I have previously set. Yeah it looks hackish but
20562 			 * we don't want to report the saved values.
20563 			 */
20564 			if (tp->ccv->cc_data)
20565 				optval = ((struct newreno *)tp->ccv->cc_data)->beta_ecn;
20566 			else
20567 				error = EINVAL;
20568 		}
20569 		break;
20570 	case TCP_RACK_DSACK_OPT:
20571 		optval = 0;
20572 		if (rack->rc_rack_tmr_std_based) {
20573 			optval |= 1;
20574 		}
20575 		if (rack->rc_rack_use_dsack) {
20576 			optval |= 2;
20577 		}
20578 		break;
20579  	case TCP_RACK_ENABLE_HYSTART:
20580 	{
20581 		struct sockopt sopt;
20582 		struct cc_newreno_opts opt;
20583 
20584 		sopt.sopt_valsize = sizeof(struct cc_newreno_opts);
20585 		sopt.sopt_dir = SOPT_GET;
20586 		opt.name = CC_NEWRENO_ENABLE_HYSTART;
20587 		if (CC_ALGO(tp)->ctl_output != NULL)
20588 			error = CC_ALGO(tp)->ctl_output(tp->ccv, &sopt, &opt);
20589 		else
20590 			error = EINVAL;
20591 		optval = opt.val;
20592 	}
20593 	break;
20594 	case TCP_FAST_RSM_HACK:
20595 		optval = rack->fast_rsm_hack;
20596 		break;
20597 	case TCP_DEFER_OPTIONS:
20598 		optval = rack->defer_options;
20599 		break;
20600 	case TCP_RACK_MEASURE_CNT:
20601 		optval = rack->r_ctl.req_measurements;
20602 		break;
20603 	case TCP_REC_ABC_VAL:
20604 		optval = rack->r_use_labc_for_rec;
20605 		break;
20606 	case TCP_RACK_ABC_VAL:
20607 		optval = rack->rc_labc;
20608 		break;
20609 	case TCP_HDWR_UP_ONLY:
20610 		optval= rack->r_up_only;
20611 		break;
20612 	case TCP_PACING_RATE_CAP:
20613 		loptval = rack->r_ctl.bw_rate_cap;
20614 		break;
20615 	case TCP_RACK_PROFILE:
20616 		/* You cannot retrieve a profile, its write only */
20617 		error = EINVAL;
20618 		break;
20619 	case TCP_USE_CMP_ACKS:
20620 		optval = rack->r_use_cmp_ack;
20621 		break;
20622 	case TCP_RACK_PACE_TO_FILL:
20623 		optval = rack->rc_pace_to_cwnd;
20624 		if (optval && rack->r_fill_less_agg)
20625 			optval++;
20626 		break;
20627 	case TCP_RACK_NO_PUSH_AT_MAX:
20628 		optval = rack->r_ctl.rc_no_push_at_mrtt;
20629 		break;
20630 	case TCP_SHARED_CWND_ENABLE:
20631 		optval = rack->rack_enable_scwnd;
20632 		break;
20633 	case TCP_RACK_NONRXT_CFG_RATE:
20634 		optval = rack->rack_rec_nonrxt_use_cr;
20635 		break;
20636 	case TCP_NO_PRR:
20637 		if (rack->rack_no_prr  == 1)
20638 			optval = 1;
20639 		else if (rack->no_prr_addback == 1)
20640 			optval = 2;
20641 		else
20642 			optval = 0;
20643 		break;
20644 	case TCP_RACK_DO_DETECTION:
20645 		optval = rack->do_detection;
20646 		break;
20647 	case TCP_RACK_MBUF_QUEUE:
20648 		/* Now do we use the LRO mbuf-queue feature */
20649 		optval = rack->r_mbuf_queue;
20650 		break;
20651 	case TCP_TIMELY_DYN_ADJ:
20652 		optval = rack->rc_gp_dyn_mul;
20653 		break;
20654 	case TCP_BBR_IWINTSO:
20655 		optval = rack->rc_init_win;
20656 		break;
20657 	case TCP_RACK_TLP_REDUCE:
20658 		/* RACK TLP cwnd reduction (bool) */
20659 		optval = rack->r_ctl.rc_tlp_cwnd_reduce;
20660 		break;
20661 	case TCP_BBR_RACK_INIT_RATE:
20662 		val = rack->r_ctl.init_rate;
20663 		/* convert to kbits per sec */
20664 		val *= 8;
20665 		val /= 1000;
20666 		optval = (uint32_t)val;
20667 		break;
20668 	case TCP_RACK_FORCE_MSEG:
20669 		optval = rack->rc_force_max_seg;
20670 		break;
20671 	case TCP_RACK_PACE_MAX_SEG:
20672 		/* Max segments in a pace */
20673 		optval = rack->rc_user_set_max_segs;
20674 		break;
20675 	case TCP_RACK_PACE_ALWAYS:
20676 		/* Use the always pace method */
20677 		optval = rack->rc_always_pace;
20678 		break;
20679 	case TCP_RACK_PRR_SENDALOT:
20680 		/* Allow PRR to send more than one seg */
20681 		optval = rack->r_ctl.rc_prr_sendalot;
20682 		break;
20683 	case TCP_RACK_MIN_TO:
20684 		/* Minimum time between rack t-o's in ms */
20685 		optval = rack->r_ctl.rc_min_to;
20686 		break;
20687 	case TCP_RACK_EARLY_SEG:
20688 		/* If early recovery max segments */
20689 		optval = rack->r_ctl.rc_early_recovery_segs;
20690 		break;
20691 	case TCP_RACK_REORD_THRESH:
20692 		/* RACK reorder threshold (shift amount) */
20693 		optval = rack->r_ctl.rc_reorder_shift;
20694 		break;
20695 	case TCP_RACK_REORD_FADE:
20696 		/* Does reordering fade after ms time */
20697 		optval = rack->r_ctl.rc_reorder_fade;
20698 		break;
20699 	case TCP_BBR_USE_RACK_RR:
20700 		/* Do we use the rack cheat for rxt */
20701 		optval = rack->use_rack_rr;
20702 		break;
20703 	case TCP_RACK_RR_CONF:
20704 		optval = rack->r_rr_config;
20705 		break;
20706 	case TCP_HDWR_RATE_CAP:
20707 		optval = rack->r_rack_hw_rate_caps;
20708 		break;
20709 	case TCP_BBR_HDWR_PACE:
20710 		optval = rack->rack_hdw_pace_ena;
20711 		break;
20712 	case TCP_RACK_TLP_THRESH:
20713 		/* RACK TLP theshold i.e. srtt+(srtt/N) */
20714 		optval = rack->r_ctl.rc_tlp_threshold;
20715 		break;
20716 	case TCP_RACK_PKT_DELAY:
20717 		/* RACK added ms i.e. rack-rtt + reord + N */
20718 		optval = rack->r_ctl.rc_pkt_delay;
20719 		break;
20720 	case TCP_RACK_TLP_USE:
20721 		optval = rack->rack_tlp_threshold_use;
20722 		break;
20723 	case TCP_RACK_PACE_RATE_CA:
20724 		optval = rack->r_ctl.rc_fixed_pacing_rate_ca;
20725 		break;
20726 	case TCP_RACK_PACE_RATE_SS:
20727 		optval = rack->r_ctl.rc_fixed_pacing_rate_ss;
20728 		break;
20729 	case TCP_RACK_PACE_RATE_REC:
20730 		optval = rack->r_ctl.rc_fixed_pacing_rate_rec;
20731 		break;
20732 	case TCP_RACK_GP_INCREASE_SS:
20733 		optval = rack->r_ctl.rack_per_of_gp_ca;
20734 		break;
20735 	case TCP_RACK_GP_INCREASE_CA:
20736 		optval = rack->r_ctl.rack_per_of_gp_ss;
20737 		break;
20738 	case TCP_BBR_RACK_RTT_USE:
20739 		optval = rack->r_ctl.rc_rate_sample_method;
20740 		break;
20741 	case TCP_DELACK:
20742 		optval = tp->t_delayed_ack;
20743 		break;
20744 	case TCP_DATA_AFTER_CLOSE:
20745 		optval = rack->rc_allow_data_af_clo;
20746 		break;
20747 	case TCP_SHARED_CWND_TIME_LIMIT:
20748 		optval = rack->r_limit_scw;
20749 		break;
20750 	case TCP_RACK_TIMER_SLOP:
20751 		optval = rack->r_ctl.timer_slop;
20752 		break;
20753 	default:
20754 		return (tcp_default_ctloutput(so, sopt, inp, tp));
20755 		break;
20756 	}
20757 	INP_WUNLOCK(inp);
20758 	if (error == 0) {
20759 		if (TCP_PACING_RATE_CAP)
20760 			error = sooptcopyout(sopt, &loptval, sizeof loptval);
20761 		else
20762 			error = sooptcopyout(sopt, &optval, sizeof optval);
20763 	}
20764 	return (error);
20765 }
20766 
20767 static int
20768 rack_ctloutput(struct socket *so, struct sockopt *sopt, struct inpcb *inp, struct tcpcb *tp)
20769 {
20770 	int32_t error = EINVAL;
20771 	struct tcp_rack *rack;
20772 
20773 	rack = (struct tcp_rack *)tp->t_fb_ptr;
20774 	if (rack == NULL) {
20775 		/* Huh? */
20776 		goto out;
20777 	}
20778 	if (sopt->sopt_dir == SOPT_SET) {
20779 		return (rack_set_sockopt(so, sopt, inp, tp, rack));
20780 	} else if (sopt->sopt_dir == SOPT_GET) {
20781 		return (rack_get_sockopt(so, sopt, inp, tp, rack));
20782 	}
20783 out:
20784 	INP_WUNLOCK(inp);
20785 	return (error);
20786 }
20787 
20788 static const char *rack_stack_names[] = {
20789 	__XSTRING(STACKNAME),
20790 #ifdef STACKALIAS
20791 	__XSTRING(STACKALIAS),
20792 #endif
20793 };
20794 
20795 static int
20796 rack_ctor(void *mem, int32_t size, void *arg, int32_t how)
20797 {
20798 	memset(mem, 0, size);
20799 	return (0);
20800 }
20801 
20802 static void
20803 rack_dtor(void *mem, int32_t size, void *arg)
20804 {
20805 
20806 }
20807 
20808 static bool rack_mod_inited = false;
20809 
20810 static int
20811 tcp_addrack(module_t mod, int32_t type, void *data)
20812 {
20813 	int32_t err = 0;
20814 	int num_stacks;
20815 
20816 	switch (type) {
20817 	case MOD_LOAD:
20818 		rack_zone = uma_zcreate(__XSTRING(MODNAME) "_map",
20819 		    sizeof(struct rack_sendmap),
20820 		    rack_ctor, rack_dtor, NULL, NULL, UMA_ALIGN_PTR, 0);
20821 
20822 		rack_pcb_zone = uma_zcreate(__XSTRING(MODNAME) "_pcb",
20823 		    sizeof(struct tcp_rack),
20824 		    rack_ctor, NULL, NULL, NULL, UMA_ALIGN_CACHE, 0);
20825 
20826 		sysctl_ctx_init(&rack_sysctl_ctx);
20827 		rack_sysctl_root = SYSCTL_ADD_NODE(&rack_sysctl_ctx,
20828 		    SYSCTL_STATIC_CHILDREN(_net_inet_tcp),
20829 		    OID_AUTO,
20830 #ifdef STACKALIAS
20831 		    __XSTRING(STACKALIAS),
20832 #else
20833 		    __XSTRING(STACKNAME),
20834 #endif
20835 		    CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
20836 		    "");
20837 		if (rack_sysctl_root == NULL) {
20838 			printf("Failed to add sysctl node\n");
20839 			err = EFAULT;
20840 			goto free_uma;
20841 		}
20842 		rack_init_sysctls();
20843 		num_stacks = nitems(rack_stack_names);
20844 		err = register_tcp_functions_as_names(&__tcp_rack, M_WAITOK,
20845 		    rack_stack_names, &num_stacks);
20846 		if (err) {
20847 			printf("Failed to register %s stack name for "
20848 			    "%s module\n", rack_stack_names[num_stacks],
20849 			    __XSTRING(MODNAME));
20850 			sysctl_ctx_free(&rack_sysctl_ctx);
20851 free_uma:
20852 			uma_zdestroy(rack_zone);
20853 			uma_zdestroy(rack_pcb_zone);
20854 			rack_counter_destroy();
20855 			printf("Failed to register rack module -- err:%d\n", err);
20856 			return (err);
20857 		}
20858 		tcp_lro_reg_mbufq();
20859 		rack_mod_inited = true;
20860 		break;
20861 	case MOD_QUIESCE:
20862 		err = deregister_tcp_functions(&__tcp_rack, true, false);
20863 		break;
20864 	case MOD_UNLOAD:
20865 		err = deregister_tcp_functions(&__tcp_rack, false, true);
20866 		if (err == EBUSY)
20867 			break;
20868 		if (rack_mod_inited) {
20869 			uma_zdestroy(rack_zone);
20870 			uma_zdestroy(rack_pcb_zone);
20871 			sysctl_ctx_free(&rack_sysctl_ctx);
20872 			rack_counter_destroy();
20873 			rack_mod_inited = false;
20874 		}
20875 		tcp_lro_dereg_mbufq();
20876 		err = 0;
20877 		break;
20878 	default:
20879 		return (EOPNOTSUPP);
20880 	}
20881 	return (err);
20882 }
20883 
20884 static moduledata_t tcp_rack = {
20885 	.name = __XSTRING(MODNAME),
20886 	.evhand = tcp_addrack,
20887 	.priv = 0
20888 };
20889 
20890 MODULE_VERSION(MODNAME, 1);
20891 DECLARE_MODULE(MODNAME, tcp_rack, SI_SUB_PROTO_DOMAIN, SI_ORDER_ANY);
20892 MODULE_DEPEND(MODNAME, tcphpts, 1, 1, 1);
20893