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 * Author: Randall Stewart <rrs@netflix.com>
28 * This work is based on the ACM Queue paper
29 * BBR - Congestion Based Congestion Control
30 * and also numerous discussions with Neal, Yuchung and Van.
31 */
32
33 #include <sys/cdefs.h>
34 #include "opt_inet.h"
35 #include "opt_inet6.h"
36 #include "opt_ipsec.h"
37 #include "opt_ratelimit.h"
38 #include <sys/param.h>
39 #include <sys/arb.h>
40 #include <sys/module.h>
41 #include <sys/kernel.h>
42 #include <sys/libkern.h>
43 #ifdef TCP_HHOOK
44 #include <sys/hhook.h>
45 #endif
46 #include <sys/malloc.h>
47 #include <sys/mbuf.h>
48 #include <sys/proc.h>
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 #endif
58 #include <sys/refcount.h>
59 #include <sys/queue.h>
60 #include <sys/eventhandler.h>
61 #include <sys/smp.h>
62 #include <sys/kthread.h>
63 #include <sys/lock.h>
64 #include <sys/mutex.h>
65 #include <sys/tim_filter.h>
66 #include <sys/time.h>
67 #include <sys/protosw.h>
68 #include <vm/uma.h>
69 #include <sys/kern_prefetch.h>
70
71 #include <net/route.h>
72 #include <net/route/nhop.h>
73 #include <net/vnet.h>
74
75 #define TCPSTATES /* for logging */
76
77 #include <netinet/in.h>
78 #include <netinet/in_kdtrace.h>
79 #include <netinet/in_pcb.h>
80 #include <netinet/ip.h>
81 #include <netinet/ip_var.h>
82 #include <netinet/ip6.h>
83 #include <netinet6/in6_pcb.h>
84 #include <netinet6/ip6_var.h>
85 #define TCPOUTFLAGS
86 #include <netinet/tcp.h>
87 #include <netinet/tcp_fsm.h>
88 #include <netinet/tcp_seq.h>
89 #include <netinet/tcp_timer.h>
90 #include <netinet/tcp_var.h>
91 #include <netinet/tcpip.h>
92 #include <netinet/tcp_hpts.h>
93 #include <netinet/cc/cc.h>
94 #include <netinet/tcp_log_buf.h>
95 #include <netinet/tcp_ratelimit.h>
96 #include <netinet/tcp_lro.h>
97 #ifdef TCP_OFFLOAD
98 #include <netinet/tcp_offload.h>
99 #endif
100 #ifdef INET6
101 #include <netinet6/tcp6_var.h>
102 #endif
103 #include <netinet/tcp_fastopen.h>
104
105 #include <netipsec/ipsec_support.h>
106 #include <net/if.h>
107 #include <net/if_var.h>
108 #include <net/ethernet.h>
109
110 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
111 #include <netipsec/ipsec.h>
112 #include <netipsec/ipsec6.h>
113 #endif /* IPSEC */
114
115 #include <netinet/udp.h>
116 #include <netinet/udp_var.h>
117 #include <machine/in_cksum.h>
118
119 #ifdef MAC
120 #include <security/mac/mac_framework.h>
121 #endif
122
123 #include "sack_filter.h"
124 #include "tcp_bbr.h"
125 #include "rack_bbr_common.h"
126 uma_zone_t bbr_zone;
127 uma_zone_t bbr_pcb_zone;
128
129 struct sysctl_ctx_list bbr_sysctl_ctx;
130 struct sysctl_oid *bbr_sysctl_root;
131
132 #define TCPT_RANGESET_NOSLOP(tv, value, tvmin, tvmax) do { \
133 (tv) = (value); \
134 if ((u_long)(tv) < (u_long)(tvmin)) \
135 (tv) = (tvmin); \
136 if ((u_long)(tv) > (u_long)(tvmax)) \
137 (tv) = (tvmax); \
138 } while(0)
139
140 /*#define BBR_INVARIANT 1*/
141
142 /*
143 * initial window
144 */
145 static uint32_t bbr_def_init_win = 10;
146 static int32_t bbr_persist_min = 250000; /* 250ms */
147 static int32_t bbr_persist_max = 1000000; /* 1 Second */
148 static int32_t bbr_cwnd_may_shrink = 0;
149 static int32_t bbr_cwndtarget_rtt_touse = BBR_RTT_PROP;
150 static int32_t bbr_num_pktepo_for_del_limit = BBR_NUM_RTTS_FOR_DEL_LIMIT;
151 static int32_t bbr_hardware_pacing_limit = 8000;
152 static int32_t bbr_quanta = 3; /* How much extra quanta do we get? */
153 static int32_t bbr_no_retran = 0;
154
155 static int32_t bbr_error_base_paceout = 10000; /* usec to pace */
156 static int32_t bbr_max_net_error_cnt = 10;
157 /* Should the following be dynamic too -- loss wise */
158 static int32_t bbr_rtt_gain_thresh = 0;
159 /* Measurement controls */
160 static int32_t bbr_use_google_algo = 1;
161 static int32_t bbr_ts_limiting = 1;
162 static int32_t bbr_ts_can_raise = 0;
163 static int32_t bbr_do_red = 600;
164 static int32_t bbr_red_scale = 20000;
165 static int32_t bbr_red_mul = 1;
166 static int32_t bbr_red_div = 2;
167 static int32_t bbr_red_growth_restrict = 1;
168 static int32_t bbr_target_is_bbunit = 0;
169 static int32_t bbr_drop_limit = 0;
170 /*
171 * How much gain do we need to see to
172 * stay in startup?
173 */
174 static int32_t bbr_marks_rxt_sack_passed = 0;
175 static int32_t bbr_start_exit = 25;
176 static int32_t bbr_low_start_exit = 25; /* When we are in reduced gain */
177 static int32_t bbr_startup_loss_thresh = 2000; /* 20.00% loss */
178 static int32_t bbr_hptsi_max_mul = 1; /* These two mul/div assure a min pacing */
179 static int32_t bbr_hptsi_max_div = 2; /* time, 0 means turned off. We need this
180 * if we go back ever to where the pacer
181 * has priority over timers.
182 */
183 static int32_t bbr_policer_call_from_rack_to = 0;
184 static int32_t bbr_policer_detection_enabled = 1;
185 static int32_t bbr_min_measurements_req = 1; /* We need at least 2
186 * measurements before we are
187 * "good" note that 2 == 1.
188 * This is because we use a >
189 * comparison. This means if
190 * min_measure was 0, it takes
191 * num-measures > min(0) and
192 * you get 1 measurement and
193 * you are good. Set to 1, you
194 * have to have two
195 * measurements (this is done
196 * to prevent it from being ok
197 * to have no measurements). */
198 static int32_t bbr_no_pacing_until = 4;
199
200 static int32_t bbr_min_usec_delta = 20000; /* 20,000 usecs */
201 static int32_t bbr_min_peer_delta = 20; /* 20 units */
202 static int32_t bbr_delta_percent = 150; /* 15.0 % */
203
204 static int32_t bbr_target_cwnd_mult_limit = 8;
205 /*
206 * bbr_cwnd_min_val is the number of
207 * segments we hold to in the RTT probe
208 * state typically 4.
209 */
210 static int32_t bbr_cwnd_min_val = BBR_PROBERTT_NUM_MSS;
211
212 static int32_t bbr_cwnd_min_val_hs = BBR_HIGHSPEED_NUM_MSS;
213
214 static int32_t bbr_gain_to_target = 1;
215 static int32_t bbr_gain_gets_extra_too = 1;
216 /*
217 * bbr_high_gain is the 2/ln(2) value we need
218 * to double the sending rate in startup. This
219 * is used for both cwnd and hptsi gain's.
220 */
221 static int32_t bbr_high_gain = BBR_UNIT * 2885 / 1000 + 1;
222 static int32_t bbr_startup_lower = BBR_UNIT * 1500 / 1000 + 1;
223 static int32_t bbr_use_lower_gain_in_startup = 1;
224
225 /* thresholds for reduction on drain in sub-states/drain */
226 static int32_t bbr_drain_rtt = BBR_SRTT;
227 static int32_t bbr_drain_floor = 88;
228 static int32_t google_allow_early_out = 1;
229 static int32_t google_consider_lost = 1;
230 static int32_t bbr_drain_drop_mul = 4;
231 static int32_t bbr_drain_drop_div = 5;
232 static int32_t bbr_rand_ot = 50;
233 static int32_t bbr_can_force_probertt = 0;
234 static int32_t bbr_can_adjust_probertt = 1;
235 static int32_t bbr_probertt_sets_rtt = 0;
236 static int32_t bbr_can_use_ts_for_rtt = 1;
237 static int32_t bbr_is_ratio = 0;
238 static int32_t bbr_sub_drain_app_limit = 1;
239 static int32_t bbr_prtt_slam_cwnd = 1;
240 static int32_t bbr_sub_drain_slam_cwnd = 1;
241 static int32_t bbr_slam_cwnd_in_main_drain = 1;
242 static int32_t bbr_filter_len_sec = 6; /* How long does the rttProp filter
243 * hold */
244 static uint32_t bbr_rtt_probe_limit = (USECS_IN_SECOND * 4);
245 /*
246 * bbr_drain_gain is the reverse of the high_gain
247 * designed to drain back out the standing queue
248 * that is formed in startup by causing a larger
249 * hptsi gain and thus drainging the packets
250 * in flight.
251 */
252 static int32_t bbr_drain_gain = BBR_UNIT * 1000 / 2885;
253 static int32_t bbr_rttprobe_gain = 192;
254
255 /*
256 * The cwnd_gain is the default cwnd gain applied when
257 * calculating a target cwnd. Note that the cwnd is
258 * a secondary factor in the way BBR works (see the
259 * paper and think about it, it will take some time).
260 * Basically the hptsi_gain spreads the packets out
261 * so you never get more than BDP to the peer even
262 * if the cwnd is high. In our implemenation that
263 * means in non-recovery/retransmission scenarios
264 * cwnd will never be reached by the flight-size.
265 */
266 static int32_t bbr_cwnd_gain = BBR_UNIT * 2;
267 static int32_t bbr_tlp_type_to_use = BBR_SRTT;
268 static int32_t bbr_delack_time = 100000; /* 100ms in useconds */
269 static int32_t bbr_sack_not_required = 0; /* set to one to allow non-sack to use bbr */
270 static int32_t bbr_initial_bw_bps = 62500; /* 500kbps in bytes ps */
271 static int32_t bbr_ignore_data_after_close = 1;
272 static int16_t bbr_hptsi_gain[] = {
273 (BBR_UNIT *5 / 4),
274 (BBR_UNIT * 3 / 4),
275 BBR_UNIT,
276 BBR_UNIT,
277 BBR_UNIT,
278 BBR_UNIT,
279 BBR_UNIT,
280 BBR_UNIT
281 };
282 int32_t bbr_use_rack_resend_cheat = 1;
283 int32_t bbr_sends_full_iwnd = 1;
284
285 #define BBR_HPTSI_GAIN_MAX 8
286 /*
287 * The BBR module incorporates a number of
288 * TCP ideas that have been put out into the IETF
289 * over the last few years:
290 * - Yuchung Cheng's RACK TCP (for which its named) that
291 * will stop us using the number of dup acks and instead
292 * use time as the gage of when we retransmit.
293 * - Reorder Detection of RFC4737 and the Tail-Loss probe draft
294 * of Dukkipati et.al.
295 * - Van Jacobson's et.al BBR.
296 *
297 * RACK depends on SACK, so if an endpoint arrives that
298 * cannot do SACK the state machine below will shuttle the
299 * connection back to using the "default" TCP stack that is
300 * in FreeBSD.
301 *
302 * To implement BBR and RACK the original TCP stack was first decomposed
303 * into a functional state machine with individual states
304 * for each of the possible TCP connection states. The do_segment
305 * functions role in life is to mandate the connection supports SACK
306 * initially and then assure that the RACK state matches the conenction
307 * state before calling the states do_segment function. Data processing
308 * of inbound segments also now happens in the hpts_do_segment in general
309 * with only one exception. This is so we can keep the connection on
310 * a single CPU.
311 *
312 * Each state is simplified due to the fact that the original do_segment
313 * has been decomposed and we *know* what state we are in (no
314 * switches on the state) and all tests for SACK are gone. This
315 * greatly simplifies what each state does.
316 *
317 * TCP output is also over-written with a new version since it
318 * must maintain the new rack scoreboard and has had hptsi
319 * integrated as a requirment. Still todo is to eliminate the
320 * use of the callout_() system and use the hpts for all
321 * timers as well.
322 */
323 static uint32_t bbr_rtt_probe_time = 200000; /* 200ms in micro seconds */
324 static uint32_t bbr_rtt_probe_cwndtarg = 4; /* How many mss's outstanding */
325 static const int32_t bbr_min_req_free = 2; /* The min we must have on the
326 * free list */
327 static int32_t bbr_tlp_thresh = 1;
328 static int32_t bbr_reorder_thresh = 2;
329 static int32_t bbr_reorder_fade = 60000000; /* 0 - never fade, def
330 * 60,000,000 - 60 seconds */
331 static int32_t bbr_pkt_delay = 1000;
332 static int32_t bbr_min_to = 1000; /* Number of usec's minimum timeout */
333 static int32_t bbr_incr_timers = 1;
334
335 static int32_t bbr_tlp_min = 10000; /* 10ms in usecs */
336 static int32_t bbr_delayed_ack_time = 200000; /* 200ms in usecs */
337 static int32_t bbr_exit_startup_at_loss = 1;
338
339 /*
340 * bbr_lt_bw_ratio is 1/8th
341 * bbr_lt_bw_diff is < 4 Kbit/sec
342 */
343 static uint64_t bbr_lt_bw_diff = 4000 / 8; /* In bytes per second */
344 static uint64_t bbr_lt_bw_ratio = 8; /* For 1/8th */
345 static uint32_t bbr_lt_bw_max_rtts = 48; /* How many rtt's do we use
346 * the lt_bw for */
347 static uint32_t bbr_lt_intvl_min_rtts = 4; /* Min num of RTT's to measure
348 * lt_bw */
349 static int32_t bbr_lt_intvl_fp = 0; /* False positive epoch diff */
350 static int32_t bbr_lt_loss_thresh = 196; /* Lost vs delivered % */
351 static int32_t bbr_lt_fd_thresh = 100; /* false detection % */
352
353 static int32_t bbr_verbose_logging = 0;
354 /*
355 * Currently regular tcp has a rto_min of 30ms
356 * the backoff goes 12 times so that ends up
357 * being a total of 122.850 seconds before a
358 * connection is killed.
359 */
360 static int32_t bbr_rto_min_ms = 30; /* 30ms same as main freebsd */
361 static int32_t bbr_rto_max_sec = 4; /* 4 seconds */
362
363 /****************************************************/
364 /* DEFAULT TSO SIZING (cpu performance impacting) */
365 /****************************************************/
366 /* What amount is our formula using to get TSO size */
367 static int32_t bbr_hptsi_per_second = 1000;
368
369 /*
370 * For hptsi under bbr_cross_over connections what is delay
371 * target 7ms (in usec) combined with a seg_max of 2
372 * gets us close to identical google behavior in
373 * TSO size selection (possibly more 1MSS sends).
374 */
375 static int32_t bbr_hptsi_segments_delay_tar = 7000;
376
377 /* Does pacing delay include overhead's in its time calculations? */
378 static int32_t bbr_include_enet_oh = 0;
379 static int32_t bbr_include_ip_oh = 1;
380 static int32_t bbr_include_tcp_oh = 1;
381 static int32_t bbr_google_discount = 10;
382
383 /* Do we use (nf mode) pkt-epoch to drive us or rttProp? */
384 static int32_t bbr_state_is_pkt_epoch = 0;
385 static int32_t bbr_state_drain_2_tar = 1;
386 /* What is the max the 0 - bbr_cross_over MBPS TSO target
387 * can reach using our delay target. Note that this
388 * value becomes the floor for the cross over
389 * algorithm.
390 */
391 static int32_t bbr_hptsi_segments_max = 2;
392 static int32_t bbr_hptsi_segments_floor = 1;
393 static int32_t bbr_hptsi_utter_max = 0;
394
395 /* What is the min the 0 - bbr_cross-over MBPS TSO target can be */
396 static int32_t bbr_hptsi_bytes_min = 1460;
397 static int32_t bbr_all_get_min = 0;
398
399 /* Cross over point from algo-a to algo-b */
400 static uint32_t bbr_cross_over = TWENTY_THREE_MBPS;
401
402 /* Do we deal with our restart state? */
403 static int32_t bbr_uses_idle_restart = 0;
404 static int32_t bbr_idle_restart_threshold = 100000; /* 100ms in useconds */
405
406 /* Do we allow hardware pacing? */
407 static int32_t bbr_allow_hdwr_pacing = 0;
408 static int32_t bbr_hdwr_pace_adjust = 2; /* multipler when we calc the tso size */
409 static int32_t bbr_hdwr_pace_floor = 1;
410 static int32_t bbr_hdwr_pacing_delay_cnt = 10;
411
412 /****************************************************/
413 static int32_t bbr_resends_use_tso = 0;
414 static int32_t bbr_tlp_max_resend = 2;
415 static int32_t bbr_sack_block_limit = 128;
416
417 #define BBR_MAX_STAT 19
418 counter_u64_t bbr_state_time[BBR_MAX_STAT];
419 counter_u64_t bbr_state_lost[BBR_MAX_STAT];
420 counter_u64_t bbr_state_resend[BBR_MAX_STAT];
421 counter_u64_t bbr_stat_arry[BBR_STAT_SIZE];
422 counter_u64_t bbr_opts_arry[BBR_OPTS_SIZE];
423 counter_u64_t bbr_out_size[TCP_MSS_ACCT_SIZE];
424 counter_u64_t bbr_flows_whdwr_pacing;
425 counter_u64_t bbr_flows_nohdwr_pacing;
426
427 counter_u64_t bbr_nohdwr_pacing_enobuf;
428 counter_u64_t bbr_hdwr_pacing_enobuf;
429
430 static inline uint64_t bbr_get_bw(struct tcp_bbr *bbr);
431
432 /*
433 * Static defintions we need for forward declarations.
434 */
435 static uint32_t
436 bbr_get_pacing_length(struct tcp_bbr *bbr, uint16_t gain,
437 uint32_t useconds_time, uint64_t bw);
438 static uint32_t
439 bbr_get_a_state_target(struct tcp_bbr *bbr, uint32_t gain);
440 static void
441 bbr_set_state(struct tcpcb *tp, struct tcp_bbr *bbr, uint32_t win);
442 static void
443 bbr_set_probebw_gains(struct tcp_bbr *bbr, uint32_t cts, uint32_t losses);
444 static void
445 bbr_substate_change(struct tcp_bbr *bbr, uint32_t cts, int line,
446 int dolog);
447 static uint32_t
448 bbr_get_target_cwnd(struct tcp_bbr *bbr, uint64_t bw, uint32_t gain);
449 static void
450 bbr_state_change(struct tcp_bbr *bbr, uint32_t cts, int32_t epoch,
451 int32_t pkt_epoch, uint32_t losses);
452 static uint32_t
453 bbr_calc_thresh_rack(struct tcp_bbr *bbr, uint32_t srtt, uint32_t cts,
454 struct bbr_sendmap *rsm);
455 static uint32_t
456 bbr_initial_cwnd(struct tcp_bbr *bbr, struct tcpcb *tp);
457 static uint32_t
458 bbr_calc_thresh_tlp(struct tcpcb *tp, struct tcp_bbr *bbr,
459 struct bbr_sendmap *rsm, uint32_t srtt, uint32_t cts);
460 static void
461 bbr_exit_persist(struct tcpcb *tp, struct tcp_bbr *bbr, uint32_t cts,
462 int32_t line);
463 static void
464 bbr_set_state_target(struct tcp_bbr *bbr, int line);
465 static void
466 bbr_enter_probe_rtt(struct tcp_bbr *bbr, uint32_t cts, int32_t line);
467 static void
468 bbr_log_progress_event(struct tcp_bbr *bbr, struct tcpcb *tp, uint32_t tick,
469 int event, int line);
470 static void
471 tcp_bbr_tso_size_check(struct tcp_bbr *bbr, uint32_t cts);
472 static void
473 bbr_setup_red_bw(struct tcp_bbr *bbr, uint32_t cts);
474 static void
475 bbr_log_rtt_shrinks(struct tcp_bbr *bbr, uint32_t cts, uint32_t applied,
476 uint32_t rtt, uint32_t line, uint8_t is_start,
477 uint16_t set);
478 static struct bbr_sendmap *
479 bbr_find_lowest_rsm(struct tcp_bbr *bbr);
480 static __inline uint32_t
481 bbr_get_rtt(struct tcp_bbr *bbr, int32_t rtt_type);
482 static void
483 bbr_log_to_start(struct tcp_bbr *bbr, uint32_t cts, uint32_t to, int32_t slot,
484 uint8_t which);
485 static void
486 bbr_log_timer_var(struct tcp_bbr *bbr, int mode, uint32_t cts,
487 uint32_t time_since_sent, uint32_t srtt,
488 uint32_t thresh, uint32_t to);
489 static void
490 bbr_log_hpts_diag(struct tcp_bbr *bbr, uint32_t cts, struct hpts_diag *diag);
491 static void
492 bbr_log_type_bbrsnd(struct tcp_bbr *bbr, uint32_t len, uint32_t slot,
493 uint32_t del_by, uint32_t cts, uint32_t sloton,
494 uint32_t prev_delay);
495 static void
496 bbr_enter_persist(struct tcpcb *tp, struct tcp_bbr *bbr, uint32_t cts,
497 int32_t line);
498 static void
499 bbr_stop_all_timers(struct tcpcb *tp, struct tcp_bbr *bbr);
500 static void
501 bbr_exit_probe_rtt(struct tcpcb *tp, struct tcp_bbr *bbr, uint32_t cts);
502 static void
503 bbr_check_probe_rtt_limits(struct tcp_bbr *bbr, uint32_t cts);
504 static void
505 bbr_timer_cancel(struct tcp_bbr *bbr, int32_t line, uint32_t cts);
506 static void
507 bbr_log_pacing_delay_calc(struct tcp_bbr *bbr, uint16_t gain, uint32_t len,
508 uint32_t cts, uint32_t usecs, uint64_t bw,
509 uint32_t override, int mod);
510 static int bbr_ctloutput(struct tcpcb *tp, struct sockopt *sopt);
511
512 static inline uint8_t
bbr_state_val(struct tcp_bbr * bbr)513 bbr_state_val(struct tcp_bbr *bbr)
514 {
515 return(bbr->rc_bbr_substate);
516 }
517
518 static inline uint32_t
get_min_cwnd(struct tcp_bbr * bbr)519 get_min_cwnd(struct tcp_bbr *bbr)
520 {
521 int mss;
522
523 mss = min((bbr->rc_tp->t_maxseg - bbr->rc_last_options),
524 bbr->r_ctl.rc_pace_max_segs);
525 if (bbr_get_rtt(bbr, BBR_RTT_PROP) < BBR_HIGH_SPEED)
526 return (bbr_cwnd_min_val_hs * mss);
527 else
528 return (bbr_cwnd_min_val * mss);
529 }
530
531 static uint32_t
bbr_get_persists_timer_val(struct tcpcb * tp,struct tcp_bbr * bbr)532 bbr_get_persists_timer_val(struct tcpcb *tp, struct tcp_bbr *bbr)
533 {
534 uint64_t srtt, var;
535 uint64_t ret_val;
536
537 bbr->r_ctl.rc_hpts_flags |= PACE_TMR_PERSIT;
538 if (tp->t_srtt == 0) {
539 srtt = (uint64_t)BBR_INITIAL_RTO;
540 var = 0;
541 } else {
542 srtt = ((uint64_t)TICKS_2_USEC(tp->t_srtt) >> TCP_RTT_SHIFT);
543 var = ((uint64_t)TICKS_2_USEC(tp->t_rttvar) >> TCP_RTT_SHIFT);
544 }
545 TCPT_RANGESET_NOSLOP(ret_val, ((srtt + var) * tcp_backoff[tp->t_rxtshift]),
546 bbr_persist_min, bbr_persist_max);
547 return ((uint32_t)ret_val);
548 }
549
550 static uint32_t
bbr_timer_start(struct tcpcb * tp,struct tcp_bbr * bbr,uint32_t cts)551 bbr_timer_start(struct tcpcb *tp, struct tcp_bbr *bbr, uint32_t cts)
552 {
553 /*
554 * Start the FR timer, we do this based on getting the first one in
555 * the rc_tmap. Note that if its NULL we must stop the timer. in all
556 * events we need to stop the running timer (if its running) before
557 * starting the new one.
558 */
559 uint32_t thresh, exp, to, srtt, time_since_sent, tstmp_touse;
560 int32_t idx;
561 int32_t is_tlp_timer = 0;
562 struct bbr_sendmap *rsm;
563
564 if (bbr->rc_all_timers_stopped) {
565 /* All timers have been stopped none are to run */
566 return (0);
567 }
568 if (bbr->rc_in_persist) {
569 /* We can't start any timer in persists */
570 return (bbr_get_persists_timer_val(tp, bbr));
571 }
572 rsm = TAILQ_FIRST(&bbr->r_ctl.rc_tmap);
573 if ((rsm == NULL) ||
574 ((tp->t_flags & TF_SACK_PERMIT) == 0) ||
575 (tp->t_state < TCPS_ESTABLISHED)) {
576 /* Nothing on the send map */
577 activate_rxt:
578 if (SEQ_LT(tp->snd_una, tp->snd_max) ||
579 sbavail(&tptosocket(tp)->so_snd)) {
580 uint64_t tov;
581
582 time_since_sent = 0;
583 rsm = TAILQ_FIRST(&bbr->r_ctl.rc_tmap);
584 if (rsm) {
585 idx = rsm->r_rtr_cnt - 1;
586 if (TSTMP_GEQ(rsm->r_tim_lastsent[idx], bbr->r_ctl.rc_tlp_rxt_last_time))
587 tstmp_touse = rsm->r_tim_lastsent[idx];
588 else
589 tstmp_touse = bbr->r_ctl.rc_tlp_rxt_last_time;
590 if (TSTMP_GT(tstmp_touse, cts))
591 time_since_sent = cts - tstmp_touse;
592 }
593 bbr->r_ctl.rc_hpts_flags |= PACE_TMR_RXT;
594 if (tp->t_srtt == 0)
595 tov = BBR_INITIAL_RTO;
596 else
597 tov = ((uint64_t)(TICKS_2_USEC(tp->t_srtt) +
598 ((uint64_t)TICKS_2_USEC(tp->t_rttvar) * (uint64_t)4)) >> TCP_RTT_SHIFT);
599 if (tp->t_rxtshift)
600 tov *= tcp_backoff[tp->t_rxtshift];
601 if (tov > time_since_sent)
602 tov -= time_since_sent;
603 else
604 tov = bbr->r_ctl.rc_min_to;
605 TCPT_RANGESET_NOSLOP(to, tov,
606 (bbr->r_ctl.rc_min_rto_ms * MS_IN_USEC),
607 (bbr->rc_max_rto_sec * USECS_IN_SECOND));
608 bbr_log_timer_var(bbr, 2, cts, 0, bbr_get_rtt(bbr, BBR_SRTT), 0, to);
609 return (to);
610 }
611 return (0);
612 }
613 if (rsm->r_flags & BBR_ACKED) {
614 rsm = bbr_find_lowest_rsm(bbr);
615 if (rsm == NULL) {
616 /* No lowest? */
617 goto activate_rxt;
618 }
619 }
620 /* Convert from ms to usecs */
621 if (rsm->r_flags & BBR_SACK_PASSED) {
622 if ((tp->t_flags & TF_SENTFIN) &&
623 ((tp->snd_max - tp->snd_una) == 1) &&
624 (rsm->r_flags & BBR_HAS_FIN)) {
625 /*
626 * We don't start a bbr rack timer if all we have is
627 * a FIN outstanding.
628 */
629 goto activate_rxt;
630 }
631 srtt = bbr_get_rtt(bbr, BBR_RTT_RACK);
632 thresh = bbr_calc_thresh_rack(bbr, srtt, cts, rsm);
633 idx = rsm->r_rtr_cnt - 1;
634 exp = rsm->r_tim_lastsent[idx] + thresh;
635 if (SEQ_GEQ(exp, cts)) {
636 to = exp - cts;
637 if (to < bbr->r_ctl.rc_min_to) {
638 to = bbr->r_ctl.rc_min_to;
639 }
640 } else {
641 to = bbr->r_ctl.rc_min_to;
642 }
643 } else {
644 /* Ok we need to do a TLP not RACK */
645 if (bbr->rc_tlp_in_progress != 0) {
646 /*
647 * The previous send was a TLP.
648 */
649 goto activate_rxt;
650 }
651 rsm = TAILQ_LAST_FAST(&bbr->r_ctl.rc_tmap, bbr_sendmap, r_tnext);
652 if (rsm == NULL) {
653 /* We found no rsm to TLP with. */
654 goto activate_rxt;
655 }
656 if (rsm->r_flags & BBR_HAS_FIN) {
657 /* If its a FIN we don't do TLP */
658 rsm = NULL;
659 goto activate_rxt;
660 }
661 time_since_sent = 0;
662 idx = rsm->r_rtr_cnt - 1;
663 if (TSTMP_GEQ(rsm->r_tim_lastsent[idx], bbr->r_ctl.rc_tlp_rxt_last_time))
664 tstmp_touse = rsm->r_tim_lastsent[idx];
665 else
666 tstmp_touse = bbr->r_ctl.rc_tlp_rxt_last_time;
667 if (TSTMP_GT(tstmp_touse, cts))
668 time_since_sent = cts - tstmp_touse;
669 is_tlp_timer = 1;
670 srtt = bbr_get_rtt(bbr, bbr_tlp_type_to_use);
671 thresh = bbr_calc_thresh_tlp(tp, bbr, rsm, srtt, cts);
672 if (thresh > time_since_sent)
673 to = thresh - time_since_sent;
674 else
675 to = bbr->r_ctl.rc_min_to;
676 if (to > (((uint32_t)bbr->rc_max_rto_sec) * USECS_IN_SECOND)) {
677 /*
678 * If the TLP time works out to larger than the max
679 * RTO lets not do TLP.. just RTO.
680 */
681 goto activate_rxt;
682 }
683 if ((bbr->rc_tlp_rtx_out == 1) &&
684 (rsm->r_start == bbr->r_ctl.rc_last_tlp_seq)) {
685 /*
686 * Second retransmit of the same TLP
687 * lets not.
688 */
689 bbr->rc_tlp_rtx_out = 0;
690 goto activate_rxt;
691 }
692 if (rsm->r_start != bbr->r_ctl.rc_last_tlp_seq) {
693 /*
694 * The tail is no longer the last one I did a probe
695 * on
696 */
697 bbr->r_ctl.rc_tlp_seg_send_cnt = 0;
698 bbr->r_ctl.rc_last_tlp_seq = rsm->r_start;
699 }
700 }
701 if (is_tlp_timer == 0) {
702 BBR_STAT_INC(bbr_to_arm_rack);
703 bbr->r_ctl.rc_hpts_flags |= PACE_TMR_RACK;
704 } else {
705 bbr_log_timer_var(bbr, 1, cts, time_since_sent, srtt, thresh, to);
706 if (bbr->r_ctl.rc_tlp_seg_send_cnt > bbr_tlp_max_resend) {
707 /*
708 * We have exceeded how many times we can retran the
709 * current TLP timer, switch to the RTO timer.
710 */
711 goto activate_rxt;
712 } else {
713 BBR_STAT_INC(bbr_to_arm_tlp);
714 bbr->r_ctl.rc_hpts_flags |= PACE_TMR_TLP;
715 }
716 }
717 return (to);
718 }
719
720 static inline int32_t
bbr_minseg(struct tcp_bbr * bbr)721 bbr_minseg(struct tcp_bbr *bbr)
722 {
723 return (bbr->r_ctl.rc_pace_min_segs - bbr->rc_last_options);
724 }
725
726 static void
bbr_start_hpts_timer(struct tcp_bbr * bbr,struct tcpcb * tp,uint32_t cts,int32_t frm,int32_t slot,uint32_t tot_len)727 bbr_start_hpts_timer(struct tcp_bbr *bbr, struct tcpcb *tp, uint32_t cts, int32_t frm, int32_t slot, uint32_t tot_len)
728 {
729 struct inpcb *inp = tptoinpcb(tp);
730 struct hpts_diag diag;
731 uint32_t delayed_ack = 0;
732 uint32_t left = 0;
733 uint32_t hpts_timeout;
734 uint8_t stopped;
735 int32_t delay_calc = 0;
736 uint32_t prev_delay = 0;
737
738 if (tcp_in_hpts(tp)) {
739 /* A previous call is already set up */
740 return;
741 }
742 if ((tp->t_state == TCPS_CLOSED) ||
743 (tp->t_state == TCPS_LISTEN)) {
744 return;
745 }
746 stopped = bbr->rc_tmr_stopped;
747 if (stopped && TSTMP_GT(bbr->r_ctl.rc_timer_exp, cts)) {
748 left = bbr->r_ctl.rc_timer_exp - cts;
749 }
750 bbr->r_ctl.rc_hpts_flags = 0;
751 bbr->r_ctl.rc_timer_exp = 0;
752 prev_delay = bbr->r_ctl.rc_last_delay_val;
753 if (bbr->r_ctl.rc_last_delay_val &&
754 (slot == 0)) {
755 /*
756 * If a previous pacer delay was in place we
757 * are not coming from the output side (where
758 * we calculate a delay, more likely a timer).
759 */
760 slot = bbr->r_ctl.rc_last_delay_val;
761 if (TSTMP_GT(cts, bbr->rc_pacer_started)) {
762 /* Compensate for time passed */
763 delay_calc = cts - bbr->rc_pacer_started;
764 if (delay_calc <= slot)
765 slot -= delay_calc;
766 }
767 }
768 /* Do we have early to make up for by pushing out the pacing time? */
769 if (bbr->r_agg_early_set) {
770 bbr_log_pacing_delay_calc(bbr, 0, bbr->r_ctl.rc_agg_early, cts, slot, 0, bbr->r_agg_early_set, 2);
771 slot += bbr->r_ctl.rc_agg_early;
772 bbr->r_ctl.rc_agg_early = 0;
773 bbr->r_agg_early_set = 0;
774 }
775 /* Are we running a total debt that needs to be compensated for? */
776 if (bbr->r_ctl.rc_hptsi_agg_delay) {
777 if (slot > bbr->r_ctl.rc_hptsi_agg_delay) {
778 /* We nuke the delay */
779 slot -= bbr->r_ctl.rc_hptsi_agg_delay;
780 bbr->r_ctl.rc_hptsi_agg_delay = 0;
781 } else {
782 /* We nuke some of the delay, put in a minimal 100usecs */
783 bbr->r_ctl.rc_hptsi_agg_delay -= slot;
784 bbr->r_ctl.rc_last_delay_val = slot = 100;
785 }
786 }
787 bbr->r_ctl.rc_last_delay_val = slot;
788 hpts_timeout = bbr_timer_start(tp, bbr, cts);
789 if (tp->t_flags & TF_DELACK) {
790 if (bbr->rc_in_persist == 0) {
791 delayed_ack = bbr_delack_time;
792 } else {
793 /*
794 * We are in persists and have
795 * gotten a new data element.
796 */
797 if (hpts_timeout > bbr_delack_time) {
798 /*
799 * Lets make the persists timer (which acks)
800 * be the smaller of hpts_timeout and bbr_delack_time.
801 */
802 hpts_timeout = bbr_delack_time;
803 }
804 }
805 }
806 if (delayed_ack &&
807 ((hpts_timeout == 0) ||
808 (delayed_ack < hpts_timeout))) {
809 /* We need a Delayed ack timer */
810 bbr->r_ctl.rc_hpts_flags = PACE_TMR_DELACK;
811 hpts_timeout = delayed_ack;
812 }
813 if (slot) {
814 /* Mark that we have a pacing timer up */
815 BBR_STAT_INC(bbr_paced_segments);
816 bbr->r_ctl.rc_hpts_flags |= PACE_PKT_OUTPUT;
817 }
818 /*
819 * If no timers are going to run and we will fall off thfe hptsi
820 * wheel, we resort to a keep-alive timer if its configured.
821 */
822 if ((hpts_timeout == 0) &&
823 (slot == 0)) {
824 if ((V_tcp_always_keepalive || inp->inp_socket->so_options & SO_KEEPALIVE) &&
825 (tp->t_state <= TCPS_CLOSING)) {
826 /*
827 * Ok we have no timer (persists, rack, tlp, rxt or
828 * del-ack), we don't have segments being paced. So
829 * all that is left is the keepalive timer.
830 */
831 if (TCPS_HAVEESTABLISHED(tp->t_state)) {
832 hpts_timeout = TICKS_2_USEC(TP_KEEPIDLE(tp));
833 } else {
834 hpts_timeout = TICKS_2_USEC(TP_KEEPINIT(tp));
835 }
836 bbr->r_ctl.rc_hpts_flags |= PACE_TMR_KEEP;
837 }
838 }
839 if (left && (stopped & (PACE_TMR_KEEP | PACE_TMR_DELACK)) ==
840 (bbr->r_ctl.rc_hpts_flags & PACE_TMR_MASK)) {
841 /*
842 * RACK, TLP, persists and RXT timers all are restartable
843 * based on actions input .. i.e we received a packet (ack
844 * or sack) and that changes things (rw, or snd_una etc).
845 * Thus we can restart them with a new value. For
846 * keep-alive, delayed_ack we keep track of what was left
847 * and restart the timer with a smaller value.
848 */
849 if (left < hpts_timeout)
850 hpts_timeout = left;
851 }
852 if (bbr->r_ctl.rc_incr_tmrs && slot &&
853 (bbr->r_ctl.rc_hpts_flags & (PACE_TMR_TLP|PACE_TMR_RXT))) {
854 /*
855 * If configured to do so, and the timer is either
856 * the TLP or RXT timer, we need to increase the timeout
857 * by the pacing time. Consider the bottleneck at my
858 * machine as an example, we are sending something
859 * to start a TLP on. The last packet won't be emitted
860 * fully until the pacing time (the bottleneck will hold
861 * the data in place). Once the packet is emitted that
862 * is when we want to start waiting for the TLP. This
863 * is most evident with hardware pacing (where the nic
864 * is holding the packet(s) before emitting). But it
865 * can also show up in the network so we do it for all
866 * cases. Technically we would take off one packet from
867 * this extra delay but this is easier and being more
868 * conservative is probably better.
869 */
870 hpts_timeout += slot;
871 }
872 if (hpts_timeout) {
873 /*
874 * Hack alert for now we can't time-out over 2147 seconds (a
875 * bit more than 35min)
876 */
877 if (hpts_timeout > 0x7ffffffe)
878 hpts_timeout = 0x7ffffffe;
879 bbr->r_ctl.rc_timer_exp = cts + hpts_timeout;
880 } else
881 bbr->r_ctl.rc_timer_exp = 0;
882 if ((slot) &&
883 (bbr->rc_use_google ||
884 bbr->output_error_seen ||
885 (slot <= hpts_timeout)) ) {
886 /*
887 * Tell LRO that it can queue packets while
888 * we pace.
889 */
890 bbr->rc_tp->t_flags2 |= TF2_MBUF_QUEUE_READY;
891 if ((bbr->r_ctl.rc_hpts_flags & PACE_TMR_RACK) &&
892 (bbr->rc_cwnd_limited == 0)) {
893 /*
894 * If we are not cwnd limited and we
895 * are running a rack timer we put on
896 * the do not disturbe even for sack.
897 */
898 tp->t_flags2 |= TF2_DONT_SACK_QUEUE;
899 } else
900 tp->t_flags2 &= ~TF2_DONT_SACK_QUEUE;
901 bbr->rc_pacer_started = cts;
902
903 (void)tcp_hpts_insert_diag(tp, HPTS_USEC_TO_SLOTS(slot),
904 __LINE__, &diag);
905 bbr->rc_timer_first = 0;
906 bbr->bbr_timer_src = frm;
907 bbr_log_to_start(bbr, cts, hpts_timeout, slot, 1);
908 bbr_log_hpts_diag(bbr, cts, &diag);
909 } else if (hpts_timeout) {
910 (void)tcp_hpts_insert_diag(tp, HPTS_USEC_TO_SLOTS(hpts_timeout),
911 __LINE__, &diag);
912 /*
913 * We add the flag here as well if the slot is set,
914 * since hpts will call in to clear the queue first before
915 * calling the output routine (which does our timers).
916 * We don't want to set the flag if its just a timer
917 * else the arrival of data might (that causes us
918 * to send more) might get delayed. Imagine being
919 * on a keep-alive timer and a request comes in for
920 * more data.
921 */
922 if (slot)
923 bbr->rc_pacer_started = cts;
924 if ((bbr->r_ctl.rc_hpts_flags & PACE_TMR_RACK) &&
925 (bbr->rc_cwnd_limited == 0)) {
926 /*
927 * For a rack timer, don't wake us even
928 * if a sack arrives as long as we are
929 * not cwnd limited.
930 */
931 tp->t_flags2 |= (TF2_MBUF_QUEUE_READY |
932 TF2_DONT_SACK_QUEUE);
933 } else {
934 /* All other timers wake us up */
935 tp->t_flags2 &= ~(TF2_MBUF_QUEUE_READY |
936 TF2_DONT_SACK_QUEUE);
937 }
938 bbr->bbr_timer_src = frm;
939 bbr_log_to_start(bbr, cts, hpts_timeout, slot, 0);
940 bbr_log_hpts_diag(bbr, cts, &diag);
941 bbr->rc_timer_first = 1;
942 }
943 bbr->rc_tmr_stopped = 0;
944 bbr_log_type_bbrsnd(bbr, tot_len, slot, delay_calc, cts, frm, prev_delay);
945 }
946
947 static void
bbr_timer_audit(struct tcpcb * tp,struct tcp_bbr * bbr,uint32_t cts,struct sockbuf * sb)948 bbr_timer_audit(struct tcpcb *tp, struct tcp_bbr *bbr, uint32_t cts, struct sockbuf *sb)
949 {
950 /*
951 * We received an ack, and then did not call send or were bounced
952 * out due to the hpts was running. Now a timer is up as well, is it
953 * the right timer?
954 */
955 struct inpcb *inp;
956 struct bbr_sendmap *rsm;
957 uint32_t hpts_timeout;
958 int tmr_up;
959
960 tmr_up = bbr->r_ctl.rc_hpts_flags & PACE_TMR_MASK;
961 if (bbr->rc_in_persist && (tmr_up == PACE_TMR_PERSIT))
962 return;
963 rsm = TAILQ_FIRST(&bbr->r_ctl.rc_tmap);
964 if (((rsm == NULL) || (tp->t_state < TCPS_ESTABLISHED)) &&
965 (tmr_up == PACE_TMR_RXT)) {
966 /* Should be an RXT */
967 return;
968 }
969 inp = bbr->rc_inp;
970 if (rsm == NULL) {
971 /* Nothing outstanding? */
972 if (tp->t_flags & TF_DELACK) {
973 if (tmr_up == PACE_TMR_DELACK)
974 /*
975 * We are supposed to have delayed ack up
976 * and we do
977 */
978 return;
979 } else if (((V_tcp_always_keepalive ||
980 inp->inp_socket->so_options & SO_KEEPALIVE) &&
981 (tp->t_state <= TCPS_CLOSING)) &&
982 (tmr_up == PACE_TMR_KEEP) &&
983 (tp->snd_max == tp->snd_una)) {
984 /* We should have keep alive up and we do */
985 return;
986 }
987 }
988 if (rsm && (rsm->r_flags & BBR_SACK_PASSED)) {
989 if ((tp->t_flags & TF_SENTFIN) &&
990 ((tp->snd_max - tp->snd_una) == 1) &&
991 (rsm->r_flags & BBR_HAS_FIN)) {
992 /* needs to be a RXT */
993 if (tmr_up == PACE_TMR_RXT)
994 return;
995 else
996 goto wrong_timer;
997 } else if (tmr_up == PACE_TMR_RACK)
998 return;
999 else
1000 goto wrong_timer;
1001 } else if (rsm && (tmr_up == PACE_TMR_RACK)) {
1002 /* Rack timer has priority if we have data out */
1003 return;
1004 } else if (SEQ_GT(tp->snd_max, tp->snd_una) &&
1005 ((tmr_up == PACE_TMR_TLP) ||
1006 (tmr_up == PACE_TMR_RXT))) {
1007 /*
1008 * Either a TLP or RXT is fine if no sack-passed is in place
1009 * and data is outstanding.
1010 */
1011 return;
1012 } else if (tmr_up == PACE_TMR_DELACK) {
1013 /*
1014 * If the delayed ack was going to go off before the
1015 * rtx/tlp/rack timer were going to expire, then that would
1016 * be the timer in control. Note we don't check the time
1017 * here trusting the code is correct.
1018 */
1019 return;
1020 }
1021 if (SEQ_GT(tp->snd_max, tp->snd_una) &&
1022 ((tmr_up == PACE_TMR_RXT) ||
1023 (tmr_up == PACE_TMR_TLP) ||
1024 (tmr_up == PACE_TMR_RACK))) {
1025 /*
1026 * We have outstanding data and
1027 * we *do* have a RACK, TLP or RXT
1028 * timer running. We won't restart
1029 * anything here since thats probably ok we
1030 * will get called with some timer here shortly.
1031 */
1032 return;
1033 }
1034 /*
1035 * Ok the timer originally started is not what we want now. We will
1036 * force the hpts to be stopped if any, and restart with the slot
1037 * set to what was in the saved slot.
1038 */
1039 wrong_timer:
1040 if ((bbr->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT) == 0) {
1041 if (tcp_in_hpts(tp))
1042 tcp_hpts_remove(tp);
1043 bbr_timer_cancel(bbr, __LINE__, cts);
1044 bbr_start_hpts_timer(bbr, tp, cts, 1, bbr->r_ctl.rc_last_delay_val,
1045 0);
1046 } else {
1047 /*
1048 * Output is hptsi so we just need to switch the type of
1049 * timer. We don't bother with keep-alive, since when we
1050 * jump through the output, it will start the keep-alive if
1051 * nothing is sent.
1052 *
1053 * We only need a delayed-ack added and or the hpts_timeout.
1054 */
1055 hpts_timeout = bbr_timer_start(tp, bbr, cts);
1056 if (tp->t_flags & TF_DELACK) {
1057 if (hpts_timeout == 0) {
1058 hpts_timeout = bbr_delack_time;
1059 bbr->r_ctl.rc_hpts_flags = PACE_TMR_DELACK;
1060 }
1061 else if (hpts_timeout > bbr_delack_time) {
1062 hpts_timeout = bbr_delack_time;
1063 bbr->r_ctl.rc_hpts_flags = PACE_TMR_DELACK;
1064 }
1065 }
1066 if (hpts_timeout) {
1067 if (hpts_timeout > 0x7ffffffe)
1068 hpts_timeout = 0x7ffffffe;
1069 bbr->r_ctl.rc_timer_exp = cts + hpts_timeout;
1070 }
1071 }
1072 }
1073
1074 int32_t bbr_clear_lost = 0;
1075
1076 /*
1077 * Considers the two time values now (cts) and earlier.
1078 * If cts is smaller than earlier, we could have
1079 * had a sequence wrap (our counter wraps every
1080 * 70 min or so) or it could be just clock skew
1081 * getting us two different time values. Clock skew
1082 * will show up within 10ms or so. So in such
1083 * a case (where cts is behind earlier time by
1084 * less than 10ms) we return 0. Otherwise we
1085 * return the true difference between them.
1086 */
1087 static inline uint32_t
bbr_calc_time(uint32_t cts,uint32_t earlier_time)1088 bbr_calc_time(uint32_t cts, uint32_t earlier_time) {
1089 /*
1090 * Given two timestamps, the current time stamp cts, and some other
1091 * time-stamp taken in theory earlier return the difference. The
1092 * trick is here sometimes locking will get the other timestamp
1093 * after the cts. If this occurs we need to return 0.
1094 */
1095 if (TSTMP_GEQ(cts, earlier_time))
1096 return (cts - earlier_time);
1097 /*
1098 * cts is behind earlier_time if its less than 10ms consider it 0.
1099 * If its more than 10ms difference then we had a time wrap. Else
1100 * its just the normal locking foo. I wonder if we should not go to
1101 * 64bit TS and get rid of this issue.
1102 */
1103 if (TSTMP_GEQ((cts + 10000), earlier_time))
1104 return (0);
1105 /*
1106 * Ok the time must have wrapped. So we need to answer a large
1107 * amount of time, which the normal subtraction should do.
1108 */
1109 return (cts - earlier_time);
1110 }
1111
1112 static int
sysctl_bbr_clear_lost(SYSCTL_HANDLER_ARGS)1113 sysctl_bbr_clear_lost(SYSCTL_HANDLER_ARGS)
1114 {
1115 uint32_t stat;
1116 int32_t error;
1117
1118 error = SYSCTL_OUT(req, &bbr_clear_lost, sizeof(uint32_t));
1119 if (error || req->newptr == NULL)
1120 return error;
1121
1122 error = SYSCTL_IN(req, &stat, sizeof(uint32_t));
1123 if (error)
1124 return (error);
1125 if (stat == 1) {
1126 #ifdef BBR_INVARIANTS
1127 printf("Clearing BBR lost counters\n");
1128 #endif
1129 COUNTER_ARRAY_ZERO(bbr_state_lost, BBR_MAX_STAT);
1130 COUNTER_ARRAY_ZERO(bbr_state_time, BBR_MAX_STAT);
1131 COUNTER_ARRAY_ZERO(bbr_state_resend, BBR_MAX_STAT);
1132 } else if (stat == 2) {
1133 #ifdef BBR_INVARIANTS
1134 printf("Clearing BBR option counters\n");
1135 #endif
1136 COUNTER_ARRAY_ZERO(bbr_opts_arry, BBR_OPTS_SIZE);
1137 } else if (stat == 3) {
1138 #ifdef BBR_INVARIANTS
1139 printf("Clearing BBR stats counters\n");
1140 #endif
1141 COUNTER_ARRAY_ZERO(bbr_stat_arry, BBR_STAT_SIZE);
1142 } else if (stat == 4) {
1143 #ifdef BBR_INVARIANTS
1144 printf("Clearing BBR out-size counters\n");
1145 #endif
1146 COUNTER_ARRAY_ZERO(bbr_out_size, TCP_MSS_ACCT_SIZE);
1147 }
1148 bbr_clear_lost = 0;
1149 return (0);
1150 }
1151
1152 static void
bbr_init_sysctls(void)1153 bbr_init_sysctls(void)
1154 {
1155 struct sysctl_oid *bbr_probertt;
1156 struct sysctl_oid *bbr_hptsi;
1157 struct sysctl_oid *bbr_measure;
1158 struct sysctl_oid *bbr_cwnd;
1159 struct sysctl_oid *bbr_timeout;
1160 struct sysctl_oid *bbr_states;
1161 struct sysctl_oid *bbr_startup;
1162 struct sysctl_oid *bbr_policer;
1163
1164 /* Probe rtt controls */
1165 bbr_probertt = SYSCTL_ADD_NODE(&bbr_sysctl_ctx,
1166 SYSCTL_CHILDREN(bbr_sysctl_root),
1167 OID_AUTO,
1168 "probertt",
1169 CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
1170 "");
1171 SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1172 SYSCTL_CHILDREN(bbr_probertt),
1173 OID_AUTO, "gain", CTLFLAG_RW,
1174 &bbr_rttprobe_gain, 192,
1175 "What is the filter gain drop in probe_rtt (0=disable)?");
1176 SYSCTL_ADD_U32(&bbr_sysctl_ctx,
1177 SYSCTL_CHILDREN(bbr_probertt),
1178 OID_AUTO, "cwnd", CTLFLAG_RW,
1179 &bbr_rtt_probe_cwndtarg, 4,
1180 "How many mss's are outstanding during probe-rtt");
1181 SYSCTL_ADD_U32(&bbr_sysctl_ctx,
1182 SYSCTL_CHILDREN(bbr_probertt),
1183 OID_AUTO, "int", CTLFLAG_RW,
1184 &bbr_rtt_probe_limit, 4000000,
1185 "If RTT has not shrank in this many micro-seconds enter probe-rtt");
1186 SYSCTL_ADD_U32(&bbr_sysctl_ctx,
1187 SYSCTL_CHILDREN(bbr_probertt),
1188 OID_AUTO, "mintime", CTLFLAG_RW,
1189 &bbr_rtt_probe_time, 200000,
1190 "How many microseconds in probe-rtt");
1191 SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1192 SYSCTL_CHILDREN(bbr_probertt),
1193 OID_AUTO, "filter_len_sec", CTLFLAG_RW,
1194 &bbr_filter_len_sec, 6,
1195 "How long in seconds does the rttProp filter run?");
1196 SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1197 SYSCTL_CHILDREN(bbr_probertt),
1198 OID_AUTO, "drain_rtt", CTLFLAG_RW,
1199 &bbr_drain_rtt, BBR_SRTT,
1200 "What is the drain rtt to use in probeRTT (rtt_prop=0, rtt_rack=1, rtt_pkt=2, rtt_srtt=3?");
1201 SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1202 SYSCTL_CHILDREN(bbr_probertt),
1203 OID_AUTO, "can_force", CTLFLAG_RW,
1204 &bbr_can_force_probertt, 0,
1205 "If we keep setting new low rtt's but delay going in probe-rtt can we force in??");
1206 SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1207 SYSCTL_CHILDREN(bbr_probertt),
1208 OID_AUTO, "enter_sets_force", CTLFLAG_RW,
1209 &bbr_probertt_sets_rtt, 0,
1210 "In NF mode, do we imitate google_mode and set the rttProp on entry to probe-rtt?");
1211 SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1212 SYSCTL_CHILDREN(bbr_probertt),
1213 OID_AUTO, "can_adjust", CTLFLAG_RW,
1214 &bbr_can_adjust_probertt, 1,
1215 "Can we dynamically adjust the probe-rtt limits and times?");
1216 SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1217 SYSCTL_CHILDREN(bbr_probertt),
1218 OID_AUTO, "is_ratio", CTLFLAG_RW,
1219 &bbr_is_ratio, 0,
1220 "is the limit to filter a ratio?");
1221 SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1222 SYSCTL_CHILDREN(bbr_probertt),
1223 OID_AUTO, "use_cwnd", CTLFLAG_RW,
1224 &bbr_prtt_slam_cwnd, 0,
1225 "Should we set/recover cwnd?");
1226 SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1227 SYSCTL_CHILDREN(bbr_probertt),
1228 OID_AUTO, "can_use_ts", CTLFLAG_RW,
1229 &bbr_can_use_ts_for_rtt, 1,
1230 "Can we use the ms timestamp if available for retransmistted rtt calculations?");
1231
1232 /* Pacing controls */
1233 bbr_hptsi = SYSCTL_ADD_NODE(&bbr_sysctl_ctx,
1234 SYSCTL_CHILDREN(bbr_sysctl_root),
1235 OID_AUTO,
1236 "pacing",
1237 CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
1238 "");
1239 SYSCTL_ADD_U32(&bbr_sysctl_ctx,
1240 SYSCTL_CHILDREN(bbr_hptsi),
1241 OID_AUTO, "hw_pacing", CTLFLAG_RW,
1242 &bbr_allow_hdwr_pacing, 1,
1243 "Do we allow hardware pacing?");
1244 SYSCTL_ADD_U32(&bbr_sysctl_ctx,
1245 SYSCTL_CHILDREN(bbr_hptsi),
1246 OID_AUTO, "hw_pacing_limit", CTLFLAG_RW,
1247 &bbr_hardware_pacing_limit, 4000,
1248 "Do we have a limited number of connections for pacing chelsio (0=no limit)?");
1249 SYSCTL_ADD_U32(&bbr_sysctl_ctx,
1250 SYSCTL_CHILDREN(bbr_hptsi),
1251 OID_AUTO, "hw_pacing_adj", CTLFLAG_RW,
1252 &bbr_hdwr_pace_adjust, 2,
1253 "Multiplier to calculated tso size?");
1254 SYSCTL_ADD_U32(&bbr_sysctl_ctx,
1255 SYSCTL_CHILDREN(bbr_hptsi),
1256 OID_AUTO, "hw_pacing_floor", CTLFLAG_RW,
1257 &bbr_hdwr_pace_floor, 1,
1258 "Do we invoke the hardware pacing floor?");
1259 SYSCTL_ADD_U32(&bbr_sysctl_ctx,
1260 SYSCTL_CHILDREN(bbr_hptsi),
1261 OID_AUTO, "hw_pacing_delay_cnt", CTLFLAG_RW,
1262 &bbr_hdwr_pacing_delay_cnt, 10,
1263 "How many packets must be sent after hdwr pacing is enabled");
1264 SYSCTL_ADD_U32(&bbr_sysctl_ctx,
1265 SYSCTL_CHILDREN(bbr_hptsi),
1266 OID_AUTO, "bw_cross", CTLFLAG_RW,
1267 &bbr_cross_over, 3000000,
1268 "What is the point where we cross over to linux like TSO size set");
1269 SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1270 SYSCTL_CHILDREN(bbr_hptsi),
1271 OID_AUTO, "seg_deltarg", CTLFLAG_RW,
1272 &bbr_hptsi_segments_delay_tar, 7000,
1273 "What is the worse case delay target for hptsi < 48Mbp connections");
1274 SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1275 SYSCTL_CHILDREN(bbr_hptsi),
1276 OID_AUTO, "enet_oh", CTLFLAG_RW,
1277 &bbr_include_enet_oh, 0,
1278 "Do we include the ethernet overhead in calculating pacing delay?");
1279 SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1280 SYSCTL_CHILDREN(bbr_hptsi),
1281 OID_AUTO, "ip_oh", CTLFLAG_RW,
1282 &bbr_include_ip_oh, 1,
1283 "Do we include the IP overhead in calculating pacing delay?");
1284 SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1285 SYSCTL_CHILDREN(bbr_hptsi),
1286 OID_AUTO, "tcp_oh", CTLFLAG_RW,
1287 &bbr_include_tcp_oh, 0,
1288 "Do we include the TCP overhead in calculating pacing delay?");
1289 SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1290 SYSCTL_CHILDREN(bbr_hptsi),
1291 OID_AUTO, "google_discount", CTLFLAG_RW,
1292 &bbr_google_discount, 10,
1293 "What is the default google discount percentage wise for pacing (11 = 1.1%%)?");
1294 SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1295 SYSCTL_CHILDREN(bbr_hptsi),
1296 OID_AUTO, "all_get_min", CTLFLAG_RW,
1297 &bbr_all_get_min, 0,
1298 "If you are less than a MSS do you just get the min?");
1299 SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1300 SYSCTL_CHILDREN(bbr_hptsi),
1301 OID_AUTO, "tso_min", CTLFLAG_RW,
1302 &bbr_hptsi_bytes_min, 1460,
1303 "For 0 -> 24Mbps what is floor number of segments for TSO");
1304 SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1305 SYSCTL_CHILDREN(bbr_hptsi),
1306 OID_AUTO, "seg_tso_max", CTLFLAG_RW,
1307 &bbr_hptsi_segments_max, 6,
1308 "For 0 -> 24Mbps what is top number of segments for TSO");
1309 SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1310 SYSCTL_CHILDREN(bbr_hptsi),
1311 OID_AUTO, "seg_floor", CTLFLAG_RW,
1312 &bbr_hptsi_segments_floor, 1,
1313 "Minimum TSO size we will fall too in segments");
1314 SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1315 SYSCTL_CHILDREN(bbr_hptsi),
1316 OID_AUTO, "utter_max", CTLFLAG_RW,
1317 &bbr_hptsi_utter_max, 0,
1318 "The absolute maximum that any pacing (outside of hardware) can be");
1319 SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1320 SYSCTL_CHILDREN(bbr_hptsi),
1321 OID_AUTO, "seg_divisor", CTLFLAG_RW,
1322 &bbr_hptsi_per_second, 100,
1323 "What is the divisor in our hptsi TSO calculation 512Mbps < X > 24Mbps ");
1324 SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1325 SYSCTL_CHILDREN(bbr_hptsi),
1326 OID_AUTO, "srtt_mul", CTLFLAG_RW,
1327 &bbr_hptsi_max_mul, 1,
1328 "The multiplier for pace len max");
1329 SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1330 SYSCTL_CHILDREN(bbr_hptsi),
1331 OID_AUTO, "srtt_div", CTLFLAG_RW,
1332 &bbr_hptsi_max_div, 2,
1333 "The divisor for pace len max");
1334 /* Measurement controls */
1335 bbr_measure = SYSCTL_ADD_NODE(&bbr_sysctl_ctx,
1336 SYSCTL_CHILDREN(bbr_sysctl_root),
1337 OID_AUTO,
1338 "measure",
1339 CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
1340 "Measurement controls");
1341 SYSCTL_ADD_U32(&bbr_sysctl_ctx,
1342 SYSCTL_CHILDREN(bbr_measure),
1343 OID_AUTO, "min_i_bw", CTLFLAG_RW,
1344 &bbr_initial_bw_bps, 62500,
1345 "Minimum initial b/w in bytes per second");
1346 SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1347 SYSCTL_CHILDREN(bbr_measure),
1348 OID_AUTO, "no_sack_needed", CTLFLAG_RW,
1349 &bbr_sack_not_required, 0,
1350 "Do we allow bbr to run on connections not supporting SACK?");
1351 SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1352 SYSCTL_CHILDREN(bbr_measure),
1353 OID_AUTO, "use_google", CTLFLAG_RW,
1354 &bbr_use_google_algo, 0,
1355 "Use has close to google V1.0 has possible?");
1356 SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1357 SYSCTL_CHILDREN(bbr_measure),
1358 OID_AUTO, "ts_limiting", CTLFLAG_RW,
1359 &bbr_ts_limiting, 1,
1360 "Do we attempt to use the peers timestamp to limit b/w caculations?");
1361 SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1362 SYSCTL_CHILDREN(bbr_measure),
1363 OID_AUTO, "ts_can_raise", CTLFLAG_RW,
1364 &bbr_ts_can_raise, 0,
1365 "Can we raise the b/w via timestamp b/w calculation?");
1366 SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1367 SYSCTL_CHILDREN(bbr_measure),
1368 OID_AUTO, "ts_delta", CTLFLAG_RW,
1369 &bbr_min_usec_delta, 20000,
1370 "How long in usec between ts of our sends in ts validation code?");
1371 SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1372 SYSCTL_CHILDREN(bbr_measure),
1373 OID_AUTO, "ts_peer_delta", CTLFLAG_RW,
1374 &bbr_min_peer_delta, 20,
1375 "What min numerical value should be between the peer deltas?");
1376 SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1377 SYSCTL_CHILDREN(bbr_measure),
1378 OID_AUTO, "ts_delta_percent", CTLFLAG_RW,
1379 &bbr_delta_percent, 150,
1380 "What percentage (150 = 15.0) do we allow variance for?");
1381 SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1382 SYSCTL_CHILDREN(bbr_measure),
1383 OID_AUTO, "min_measure_good_bw", CTLFLAG_RW,
1384 &bbr_min_measurements_req, 1,
1385 "What is the minimum measurement count we need before we switch to our b/w estimate");
1386 SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1387 SYSCTL_CHILDREN(bbr_measure),
1388 OID_AUTO, "min_measure_before_pace", CTLFLAG_RW,
1389 &bbr_no_pacing_until, 4,
1390 "How many pkt-epoch's (0 is off) do we need before pacing is on?");
1391 SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1392 SYSCTL_CHILDREN(bbr_measure),
1393 OID_AUTO, "quanta", CTLFLAG_RW,
1394 &bbr_quanta, 2,
1395 "Extra quanta to add when calculating the target (ID section 4.2.3.2).");
1396 SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1397 SYSCTL_CHILDREN(bbr_measure),
1398 OID_AUTO, "noretran", CTLFLAG_RW,
1399 &bbr_no_retran, 0,
1400 "Should google mode not use retransmission measurements for the b/w estimation?");
1401 /* State controls */
1402 bbr_states = SYSCTL_ADD_NODE(&bbr_sysctl_ctx,
1403 SYSCTL_CHILDREN(bbr_sysctl_root),
1404 OID_AUTO,
1405 "states",
1406 CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
1407 "State controls");
1408 SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1409 SYSCTL_CHILDREN(bbr_states),
1410 OID_AUTO, "idle_restart", CTLFLAG_RW,
1411 &bbr_uses_idle_restart, 0,
1412 "Do we use a new special idle_restart state to ramp back up quickly?");
1413 SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1414 SYSCTL_CHILDREN(bbr_states),
1415 OID_AUTO, "idle_restart_threshold", CTLFLAG_RW,
1416 &bbr_idle_restart_threshold, 100000,
1417 "How long must we be idle before we restart??");
1418 SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1419 SYSCTL_CHILDREN(bbr_states),
1420 OID_AUTO, "use_pkt_epoch", CTLFLAG_RW,
1421 &bbr_state_is_pkt_epoch, 0,
1422 "Do we use a pkt-epoch for substate if 0 rttProp?");
1423 SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1424 SYSCTL_CHILDREN(bbr_states),
1425 OID_AUTO, "startup_rtt_gain", CTLFLAG_RW,
1426 &bbr_rtt_gain_thresh, 0,
1427 "What increase in RTT triggers us to stop ignoring no-loss and possibly exit startup?");
1428 SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1429 SYSCTL_CHILDREN(bbr_states),
1430 OID_AUTO, "drain_floor", CTLFLAG_RW,
1431 &bbr_drain_floor, 88,
1432 "What is the lowest we can drain (pg) too?");
1433 SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1434 SYSCTL_CHILDREN(bbr_states),
1435 OID_AUTO, "drain_2_target", CTLFLAG_RW,
1436 &bbr_state_drain_2_tar, 1,
1437 "Do we drain to target in drain substate?");
1438 SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1439 SYSCTL_CHILDREN(bbr_states),
1440 OID_AUTO, "gain_2_target", CTLFLAG_RW,
1441 &bbr_gain_to_target, 1,
1442 "Does probe bw gain to target??");
1443 SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1444 SYSCTL_CHILDREN(bbr_states),
1445 OID_AUTO, "gain_extra_time", CTLFLAG_RW,
1446 &bbr_gain_gets_extra_too, 1,
1447 "Does probe bw gain get the extra time too?");
1448 SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1449 SYSCTL_CHILDREN(bbr_states),
1450 OID_AUTO, "ld_div", CTLFLAG_RW,
1451 &bbr_drain_drop_div, 5,
1452 "Long drain drop divider?");
1453 SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1454 SYSCTL_CHILDREN(bbr_states),
1455 OID_AUTO, "ld_mul", CTLFLAG_RW,
1456 &bbr_drain_drop_mul, 4,
1457 "Long drain drop multiplier?");
1458 SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1459 SYSCTL_CHILDREN(bbr_states),
1460 OID_AUTO, "rand_ot_disc", CTLFLAG_RW,
1461 &bbr_rand_ot, 50,
1462 "Random discount of the ot?");
1463 SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1464 SYSCTL_CHILDREN(bbr_states),
1465 OID_AUTO, "dr_filter_life", CTLFLAG_RW,
1466 &bbr_num_pktepo_for_del_limit, BBR_NUM_RTTS_FOR_DEL_LIMIT,
1467 "How many packet-epochs does the b/w delivery rate last?");
1468 SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1469 SYSCTL_CHILDREN(bbr_states),
1470 OID_AUTO, "subdrain_applimited", CTLFLAG_RW,
1471 &bbr_sub_drain_app_limit, 0,
1472 "Does our sub-state drain invoke app limited if its long?");
1473 SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1474 SYSCTL_CHILDREN(bbr_states),
1475 OID_AUTO, "use_cwnd_subdrain", CTLFLAG_RW,
1476 &bbr_sub_drain_slam_cwnd, 0,
1477 "Should we set/recover cwnd for sub-state drain?");
1478 SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1479 SYSCTL_CHILDREN(bbr_states),
1480 OID_AUTO, "use_cwnd_maindrain", CTLFLAG_RW,
1481 &bbr_slam_cwnd_in_main_drain, 0,
1482 "Should we set/recover cwnd for main-state drain?");
1483 SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1484 SYSCTL_CHILDREN(bbr_states),
1485 OID_AUTO, "google_gets_earlyout", CTLFLAG_RW,
1486 &google_allow_early_out, 1,
1487 "Should we allow google probe-bw/drain to exit early at flight target?");
1488 SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1489 SYSCTL_CHILDREN(bbr_states),
1490 OID_AUTO, "google_exit_loss", CTLFLAG_RW,
1491 &google_consider_lost, 1,
1492 "Should we have losses exit gain of probebw in google mode??");
1493 /* Startup controls */
1494 bbr_startup = SYSCTL_ADD_NODE(&bbr_sysctl_ctx,
1495 SYSCTL_CHILDREN(bbr_sysctl_root),
1496 OID_AUTO,
1497 "startup",
1498 CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
1499 "Startup controls");
1500 SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1501 SYSCTL_CHILDREN(bbr_startup),
1502 OID_AUTO, "cheat_iwnd", CTLFLAG_RW,
1503 &bbr_sends_full_iwnd, 1,
1504 "Do we not pace but burst out initial windows has our TSO size?");
1505 SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1506 SYSCTL_CHILDREN(bbr_startup),
1507 OID_AUTO, "loss_threshold", CTLFLAG_RW,
1508 &bbr_startup_loss_thresh, 2000,
1509 "In startup what is the loss threshold in a pe that will exit us from startup?");
1510 SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1511 SYSCTL_CHILDREN(bbr_startup),
1512 OID_AUTO, "use_lowerpg", CTLFLAG_RW,
1513 &bbr_use_lower_gain_in_startup, 1,
1514 "Should we use a lower hptsi gain if we see loss in startup?");
1515 SYSCTL_ADD_U32(&bbr_sysctl_ctx,
1516 SYSCTL_CHILDREN(bbr_startup),
1517 OID_AUTO, "gain", CTLFLAG_RW,
1518 &bbr_start_exit, 25,
1519 "What gain percent do we need to see to stay in startup??");
1520 SYSCTL_ADD_U32(&bbr_sysctl_ctx,
1521 SYSCTL_CHILDREN(bbr_startup),
1522 OID_AUTO, "low_gain", CTLFLAG_RW,
1523 &bbr_low_start_exit, 15,
1524 "What gain percent do we need to see to stay in the lower gain startup??");
1525 SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1526 SYSCTL_CHILDREN(bbr_startup),
1527 OID_AUTO, "loss_exit", CTLFLAG_RW,
1528 &bbr_exit_startup_at_loss, 1,
1529 "Should we exit startup at loss in an epoch if we are not gaining?");
1530 /* CWND controls */
1531 bbr_cwnd = SYSCTL_ADD_NODE(&bbr_sysctl_ctx,
1532 SYSCTL_CHILDREN(bbr_sysctl_root),
1533 OID_AUTO,
1534 "cwnd",
1535 CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
1536 "Cwnd controls");
1537 SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1538 SYSCTL_CHILDREN(bbr_cwnd),
1539 OID_AUTO, "tar_rtt", CTLFLAG_RW,
1540 &bbr_cwndtarget_rtt_touse, 0,
1541 "Target cwnd rtt measurement to use (0=rtt_prop, 1=rtt_rack, 2=pkt_rtt, 3=srtt)?");
1542 SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1543 SYSCTL_CHILDREN(bbr_cwnd),
1544 OID_AUTO, "may_shrink", CTLFLAG_RW,
1545 &bbr_cwnd_may_shrink, 0,
1546 "Can the cwnd shrink if it would grow to more than the target?");
1547 SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1548 SYSCTL_CHILDREN(bbr_cwnd),
1549 OID_AUTO, "max_target_limit", CTLFLAG_RW,
1550 &bbr_target_cwnd_mult_limit, 8,
1551 "Do we limit the cwnd to some multiple of the cwnd target if cwnd can't shrink 0=no?");
1552 SYSCTL_ADD_U32(&bbr_sysctl_ctx,
1553 SYSCTL_CHILDREN(bbr_cwnd),
1554 OID_AUTO, "highspeed_min", CTLFLAG_RW,
1555 &bbr_cwnd_min_val_hs, BBR_HIGHSPEED_NUM_MSS,
1556 "What is the high-speed min cwnd (rttProp under 1ms)");
1557 SYSCTL_ADD_U32(&bbr_sysctl_ctx,
1558 SYSCTL_CHILDREN(bbr_cwnd),
1559 OID_AUTO, "lowspeed_min", CTLFLAG_RW,
1560 &bbr_cwnd_min_val, BBR_PROBERTT_NUM_MSS,
1561 "What is the min cwnd (rttProp > 1ms)");
1562 SYSCTL_ADD_U32(&bbr_sysctl_ctx,
1563 SYSCTL_CHILDREN(bbr_cwnd),
1564 OID_AUTO, "initwin", CTLFLAG_RW,
1565 &bbr_def_init_win, 10,
1566 "What is the BBR initial window, if 0 use tcp version");
1567 SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1568 SYSCTL_CHILDREN(bbr_cwnd),
1569 OID_AUTO, "do_loss_red", CTLFLAG_RW,
1570 &bbr_do_red, 600,
1571 "Do we reduce the b/w at exit from recovery based on ratio of prop/srtt (800=80.0, 0=off)?");
1572 SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1573 SYSCTL_CHILDREN(bbr_cwnd),
1574 OID_AUTO, "red_scale", CTLFLAG_RW,
1575 &bbr_red_scale, 20000,
1576 "What RTT do we scale with?");
1577 SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1578 SYSCTL_CHILDREN(bbr_cwnd),
1579 OID_AUTO, "red_growslow", CTLFLAG_RW,
1580 &bbr_red_growth_restrict, 1,
1581 "Do we restrict cwnd growth for whats in flight?");
1582 SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1583 SYSCTL_CHILDREN(bbr_cwnd),
1584 OID_AUTO, "red_div", CTLFLAG_RW,
1585 &bbr_red_div, 2,
1586 "If we reduce whats the divisor?");
1587 SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1588 SYSCTL_CHILDREN(bbr_cwnd),
1589 OID_AUTO, "red_mul", CTLFLAG_RW,
1590 &bbr_red_mul, 1,
1591 "If we reduce whats the mulitiplier?");
1592 SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1593 SYSCTL_CHILDREN(bbr_cwnd),
1594 OID_AUTO, "target_is_unit", CTLFLAG_RW,
1595 &bbr_target_is_bbunit, 0,
1596 "Is the state target the pacing_gain or BBR_UNIT?");
1597 SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1598 SYSCTL_CHILDREN(bbr_cwnd),
1599 OID_AUTO, "drop_limit", CTLFLAG_RW,
1600 &bbr_drop_limit, 0,
1601 "Number of segments limit for drop (0=use min_cwnd w/flight)?");
1602
1603 /* Timeout controls */
1604 bbr_timeout = SYSCTL_ADD_NODE(&bbr_sysctl_ctx,
1605 SYSCTL_CHILDREN(bbr_sysctl_root),
1606 OID_AUTO,
1607 "timeout",
1608 CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
1609 "Time out controls");
1610 SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1611 SYSCTL_CHILDREN(bbr_timeout),
1612 OID_AUTO, "delack", CTLFLAG_RW,
1613 &bbr_delack_time, 100000,
1614 "BBR's delayed ack time");
1615 SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1616 SYSCTL_CHILDREN(bbr_timeout),
1617 OID_AUTO, "tlp_uses", CTLFLAG_RW,
1618 &bbr_tlp_type_to_use, 3,
1619 "RTT that TLP uses in its calculations, 0=rttProp, 1=Rack_rtt, 2=pkt_rtt and 3=srtt");
1620 SYSCTL_ADD_U32(&bbr_sysctl_ctx,
1621 SYSCTL_CHILDREN(bbr_timeout),
1622 OID_AUTO, "persmin", CTLFLAG_RW,
1623 &bbr_persist_min, 250000,
1624 "What is the minimum time in microseconds between persists");
1625 SYSCTL_ADD_U32(&bbr_sysctl_ctx,
1626 SYSCTL_CHILDREN(bbr_timeout),
1627 OID_AUTO, "persmax", CTLFLAG_RW,
1628 &bbr_persist_max, 1000000,
1629 "What is the largest delay in microseconds between persists");
1630 SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1631 SYSCTL_CHILDREN(bbr_timeout),
1632 OID_AUTO, "tlp_minto", CTLFLAG_RW,
1633 &bbr_tlp_min, 10000,
1634 "TLP Min timeout in usecs");
1635 SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1636 SYSCTL_CHILDREN(bbr_timeout),
1637 OID_AUTO, "tlp_dack_time", CTLFLAG_RW,
1638 &bbr_delayed_ack_time, 200000,
1639 "TLP delayed ack compensation value");
1640 SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1641 SYSCTL_CHILDREN(bbr_sysctl_root),
1642 OID_AUTO, "minrto", CTLFLAG_RW,
1643 &bbr_rto_min_ms, 30,
1644 "Minimum RTO in ms");
1645 SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1646 SYSCTL_CHILDREN(bbr_timeout),
1647 OID_AUTO, "maxrto", CTLFLAG_RW,
1648 &bbr_rto_max_sec, 4,
1649 "Maximum RTO in seconds -- should be at least as large as min_rto");
1650 SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1651 SYSCTL_CHILDREN(bbr_timeout),
1652 OID_AUTO, "tlp_retry", CTLFLAG_RW,
1653 &bbr_tlp_max_resend, 2,
1654 "How many times does TLP retry a single segment or multiple with no ACK");
1655 SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1656 SYSCTL_CHILDREN(bbr_timeout),
1657 OID_AUTO, "minto", CTLFLAG_RW,
1658 &bbr_min_to, 1000,
1659 "Minimum rack timeout in useconds");
1660 SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1661 SYSCTL_CHILDREN(bbr_timeout),
1662 OID_AUTO, "pktdelay", CTLFLAG_RW,
1663 &bbr_pkt_delay, 1000,
1664 "Extra RACK time (in useconds) besides reordering thresh");
1665 SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1666 SYSCTL_CHILDREN(bbr_timeout),
1667 OID_AUTO, "incr_tmrs", CTLFLAG_RW,
1668 &bbr_incr_timers, 1,
1669 "Increase the RXT/TLP timer by the pacing time used?");
1670 SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1671 SYSCTL_CHILDREN(bbr_timeout),
1672 OID_AUTO, "rxtmark_sackpassed", CTLFLAG_RW,
1673 &bbr_marks_rxt_sack_passed, 0,
1674 "Mark sack passed on all those not ack'd when a RXT hits?");
1675 /* Policer controls */
1676 bbr_policer = SYSCTL_ADD_NODE(&bbr_sysctl_ctx,
1677 SYSCTL_CHILDREN(bbr_sysctl_root),
1678 OID_AUTO,
1679 "policer",
1680 CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
1681 "Policer controls");
1682 SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1683 SYSCTL_CHILDREN(bbr_policer),
1684 OID_AUTO, "detect_enable", CTLFLAG_RW,
1685 &bbr_policer_detection_enabled, 1,
1686 "Is policer detection enabled??");
1687 SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1688 SYSCTL_CHILDREN(bbr_policer),
1689 OID_AUTO, "min_pes", CTLFLAG_RW,
1690 &bbr_lt_intvl_min_rtts, 4,
1691 "Minimum number of PE's?");
1692 SYSCTL_ADD_U64(&bbr_sysctl_ctx,
1693 SYSCTL_CHILDREN(bbr_policer),
1694 OID_AUTO, "bwdiff", CTLFLAG_RW,
1695 &bbr_lt_bw_diff, (4000/8),
1696 "Minimal bw diff?");
1697 SYSCTL_ADD_U64(&bbr_sysctl_ctx,
1698 SYSCTL_CHILDREN(bbr_policer),
1699 OID_AUTO, "bwratio", CTLFLAG_RW,
1700 &bbr_lt_bw_ratio, 8,
1701 "Minimal bw diff?");
1702 SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1703 SYSCTL_CHILDREN(bbr_policer),
1704 OID_AUTO, "from_rack_rxt", CTLFLAG_RW,
1705 &bbr_policer_call_from_rack_to, 0,
1706 "Do we call the policer detection code from a rack-timeout?");
1707 SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1708 SYSCTL_CHILDREN(bbr_policer),
1709 OID_AUTO, "false_postive", CTLFLAG_RW,
1710 &bbr_lt_intvl_fp, 0,
1711 "What packet epoch do we do false-positive detection at (0=no)?");
1712 SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1713 SYSCTL_CHILDREN(bbr_policer),
1714 OID_AUTO, "loss_thresh", CTLFLAG_RW,
1715 &bbr_lt_loss_thresh, 196,
1716 "Loss threshold 196 = 19.6%?");
1717 SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1718 SYSCTL_CHILDREN(bbr_policer),
1719 OID_AUTO, "false_postive_thresh", CTLFLAG_RW,
1720 &bbr_lt_fd_thresh, 100,
1721 "What percentage is the false detection threshold (150=15.0)?");
1722 /* All the rest */
1723 SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1724 SYSCTL_CHILDREN(bbr_sysctl_root),
1725 OID_AUTO, "cheat_rxt", CTLFLAG_RW,
1726 &bbr_use_rack_resend_cheat, 0,
1727 "Do we burst 1ms between sends on retransmissions (like rack)?");
1728 SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1729 SYSCTL_CHILDREN(bbr_sysctl_root),
1730 OID_AUTO, "error_paceout", CTLFLAG_RW,
1731 &bbr_error_base_paceout, 10000,
1732 "When we hit an error what is the min to pace out in usec's?");
1733 SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1734 SYSCTL_CHILDREN(bbr_sysctl_root),
1735 OID_AUTO, "kill_paceout", CTLFLAG_RW,
1736 &bbr_max_net_error_cnt, 10,
1737 "When we hit this many errors in a row, kill the session?");
1738 SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1739 SYSCTL_CHILDREN(bbr_sysctl_root),
1740 OID_AUTO, "data_after_close", CTLFLAG_RW,
1741 &bbr_ignore_data_after_close, 1,
1742 "Do we hold off sending a RST until all pending data is ack'd");
1743 SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1744 SYSCTL_CHILDREN(bbr_sysctl_root),
1745 OID_AUTO, "resend_use_tso", CTLFLAG_RW,
1746 &bbr_resends_use_tso, 0,
1747 "Can resends use TSO?");
1748 SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1749 SYSCTL_CHILDREN(bbr_sysctl_root),
1750 OID_AUTO, "sblklimit", CTLFLAG_RW,
1751 &bbr_sack_block_limit, 128,
1752 "When do we start ignoring small sack blocks");
1753 SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1754 SYSCTL_CHILDREN(bbr_sysctl_root),
1755 OID_AUTO, "bb_verbose", CTLFLAG_RW,
1756 &bbr_verbose_logging, 0,
1757 "Should BBR black box logging be verbose");
1758 SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1759 SYSCTL_CHILDREN(bbr_sysctl_root),
1760 OID_AUTO, "reorder_thresh", CTLFLAG_RW,
1761 &bbr_reorder_thresh, 2,
1762 "What factor for rack will be added when seeing reordering (shift right)");
1763 SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1764 SYSCTL_CHILDREN(bbr_sysctl_root),
1765 OID_AUTO, "reorder_fade", CTLFLAG_RW,
1766 &bbr_reorder_fade, 0,
1767 "Does reorder detection fade, if so how many ms (0 means never)");
1768 SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1769 SYSCTL_CHILDREN(bbr_sysctl_root),
1770 OID_AUTO, "rtt_tlp_thresh", CTLFLAG_RW,
1771 &bbr_tlp_thresh, 1,
1772 "what divisor for TLP rtt/retran will be added (1=rtt, 2=1/2 rtt etc)");
1773 /* Stats and counters */
1774 /* The pacing counters for hdwr/software can't be in the array */
1775 bbr_nohdwr_pacing_enobuf = counter_u64_alloc(M_WAITOK);
1776 bbr_hdwr_pacing_enobuf = counter_u64_alloc(M_WAITOK);
1777 SYSCTL_ADD_COUNTER_U64(&bbr_sysctl_ctx,
1778 SYSCTL_CHILDREN(bbr_sysctl_root),
1779 OID_AUTO, "enob_hdwr_pacing", CTLFLAG_RD,
1780 &bbr_hdwr_pacing_enobuf,
1781 "Total number of enobufs for hardware paced flows");
1782 SYSCTL_ADD_COUNTER_U64(&bbr_sysctl_ctx,
1783 SYSCTL_CHILDREN(bbr_sysctl_root),
1784 OID_AUTO, "enob_no_hdwr_pacing", CTLFLAG_RD,
1785 &bbr_nohdwr_pacing_enobuf,
1786 "Total number of enobufs for non-hardware paced flows");
1787
1788 bbr_flows_whdwr_pacing = counter_u64_alloc(M_WAITOK);
1789 SYSCTL_ADD_COUNTER_U64(&bbr_sysctl_ctx,
1790 SYSCTL_CHILDREN(bbr_sysctl_root),
1791 OID_AUTO, "hdwr_pacing", CTLFLAG_RD,
1792 &bbr_flows_whdwr_pacing,
1793 "Total number of hardware paced flows");
1794 bbr_flows_nohdwr_pacing = counter_u64_alloc(M_WAITOK);
1795 SYSCTL_ADD_COUNTER_U64(&bbr_sysctl_ctx,
1796 SYSCTL_CHILDREN(bbr_sysctl_root),
1797 OID_AUTO, "software_pacing", CTLFLAG_RD,
1798 &bbr_flows_nohdwr_pacing,
1799 "Total number of software paced flows");
1800 COUNTER_ARRAY_ALLOC(bbr_stat_arry, BBR_STAT_SIZE, M_WAITOK);
1801 SYSCTL_ADD_COUNTER_U64_ARRAY(&bbr_sysctl_ctx, SYSCTL_CHILDREN(bbr_sysctl_root),
1802 OID_AUTO, "stats", CTLFLAG_RD,
1803 bbr_stat_arry, BBR_STAT_SIZE, "BBR Stats");
1804 COUNTER_ARRAY_ALLOC(bbr_opts_arry, BBR_OPTS_SIZE, M_WAITOK);
1805 SYSCTL_ADD_COUNTER_U64_ARRAY(&bbr_sysctl_ctx, SYSCTL_CHILDREN(bbr_sysctl_root),
1806 OID_AUTO, "opts", CTLFLAG_RD,
1807 bbr_opts_arry, BBR_OPTS_SIZE, "BBR Option Stats");
1808 COUNTER_ARRAY_ALLOC(bbr_state_lost, BBR_MAX_STAT, M_WAITOK);
1809 SYSCTL_ADD_COUNTER_U64_ARRAY(&bbr_sysctl_ctx, SYSCTL_CHILDREN(bbr_sysctl_root),
1810 OID_AUTO, "lost", CTLFLAG_RD,
1811 bbr_state_lost, BBR_MAX_STAT, "Stats of when losses occur");
1812 COUNTER_ARRAY_ALLOC(bbr_state_resend, BBR_MAX_STAT, M_WAITOK);
1813 SYSCTL_ADD_COUNTER_U64_ARRAY(&bbr_sysctl_ctx, SYSCTL_CHILDREN(bbr_sysctl_root),
1814 OID_AUTO, "stateresend", CTLFLAG_RD,
1815 bbr_state_resend, BBR_MAX_STAT, "Stats of what states resend");
1816 COUNTER_ARRAY_ALLOC(bbr_state_time, BBR_MAX_STAT, M_WAITOK);
1817 SYSCTL_ADD_COUNTER_U64_ARRAY(&bbr_sysctl_ctx, SYSCTL_CHILDREN(bbr_sysctl_root),
1818 OID_AUTO, "statetime", CTLFLAG_RD,
1819 bbr_state_time, BBR_MAX_STAT, "Stats of time spent in the states");
1820 COUNTER_ARRAY_ALLOC(bbr_out_size, TCP_MSS_ACCT_SIZE, M_WAITOK);
1821 SYSCTL_ADD_COUNTER_U64_ARRAY(&bbr_sysctl_ctx, SYSCTL_CHILDREN(bbr_sysctl_root),
1822 OID_AUTO, "outsize", CTLFLAG_RD,
1823 bbr_out_size, TCP_MSS_ACCT_SIZE, "Size of output calls");
1824 SYSCTL_ADD_PROC(&bbr_sysctl_ctx,
1825 SYSCTL_CHILDREN(bbr_sysctl_root),
1826 OID_AUTO, "clrlost", CTLTYPE_UINT | CTLFLAG_RW | CTLFLAG_MPSAFE,
1827 &bbr_clear_lost, 0, sysctl_bbr_clear_lost, "IU", "Clear lost counters");
1828 }
1829
1830 static void
bbr_counter_destroy(void)1831 bbr_counter_destroy(void)
1832 {
1833 COUNTER_ARRAY_FREE(bbr_stat_arry, BBR_STAT_SIZE);
1834 COUNTER_ARRAY_FREE(bbr_opts_arry, BBR_OPTS_SIZE);
1835 COUNTER_ARRAY_FREE(bbr_out_size, TCP_MSS_ACCT_SIZE);
1836 COUNTER_ARRAY_FREE(bbr_state_lost, BBR_MAX_STAT);
1837 COUNTER_ARRAY_FREE(bbr_state_time, BBR_MAX_STAT);
1838 COUNTER_ARRAY_FREE(bbr_state_resend, BBR_MAX_STAT);
1839 counter_u64_free(bbr_nohdwr_pacing_enobuf);
1840 counter_u64_free(bbr_hdwr_pacing_enobuf);
1841 counter_u64_free(bbr_flows_whdwr_pacing);
1842 counter_u64_free(bbr_flows_nohdwr_pacing);
1843
1844 }
1845
1846 static __inline void
bbr_fill_in_logging_data(struct tcp_bbr * bbr,struct tcp_log_bbr * l,uint32_t cts)1847 bbr_fill_in_logging_data(struct tcp_bbr *bbr, struct tcp_log_bbr *l, uint32_t cts)
1848 {
1849 memset(l, 0, sizeof(union tcp_log_stackspecific));
1850 l->cur_del_rate = bbr->r_ctl.rc_bbr_cur_del_rate;
1851 l->delRate = get_filter_value(&bbr->r_ctl.rc_delrate);
1852 l->rttProp = get_filter_value_small(&bbr->r_ctl.rc_rttprop);
1853 l->bw_inuse = bbr_get_bw(bbr);
1854 l->inflight = ctf_flight_size(bbr->rc_tp,
1855 (bbr->r_ctl.rc_sacked + bbr->r_ctl.rc_lost_bytes));
1856 l->applimited = bbr->r_ctl.r_app_limited_until;
1857 l->delivered = bbr->r_ctl.rc_delivered;
1858 l->timeStamp = cts;
1859 l->lost = bbr->r_ctl.rc_lost;
1860 l->bbr_state = bbr->rc_bbr_state;
1861 l->bbr_substate = bbr_state_val(bbr);
1862 l->epoch = bbr->r_ctl.rc_rtt_epoch;
1863 l->lt_epoch = bbr->r_ctl.rc_lt_epoch;
1864 l->pacing_gain = bbr->r_ctl.rc_bbr_hptsi_gain;
1865 l->cwnd_gain = bbr->r_ctl.rc_bbr_cwnd_gain;
1866 l->inhpts = tcp_in_hpts(bbr->rc_tp);
1867 l->use_lt_bw = bbr->rc_lt_use_bw;
1868 l->pkts_out = bbr->r_ctl.rc_flight_at_input;
1869 l->pkt_epoch = bbr->r_ctl.rc_pkt_epoch;
1870 }
1871
1872 static void
bbr_log_type_bw_reduce(struct tcp_bbr * bbr,int reason)1873 bbr_log_type_bw_reduce(struct tcp_bbr *bbr, int reason)
1874 {
1875 if (tcp_bblogging_on(bbr->rc_tp)) {
1876 union tcp_log_stackspecific log;
1877
1878 bbr_fill_in_logging_data(bbr, &log.u_bbr, bbr->r_ctl.rc_rcvtime);
1879 log.u_bbr.flex1 = 0;
1880 log.u_bbr.flex2 = 0;
1881 log.u_bbr.flex5 = 0;
1882 log.u_bbr.flex3 = 0;
1883 log.u_bbr.flex4 = bbr->r_ctl.rc_pkt_epoch_loss_rate;
1884 log.u_bbr.flex7 = reason;
1885 log.u_bbr.flex6 = bbr->r_ctl.rc_bbr_enters_probertt;
1886 log.u_bbr.flex8 = 0;
1887 TCP_LOG_EVENTP(bbr->rc_tp, NULL,
1888 &bbr->rc_inp->inp_socket->so_rcv,
1889 &bbr->rc_inp->inp_socket->so_snd,
1890 BBR_LOG_BW_RED_EV, 0,
1891 0, &log, false, &bbr->rc_tv);
1892 }
1893 }
1894
1895 static void
bbr_log_type_rwnd_collapse(struct tcp_bbr * bbr,int seq,int mode,uint32_t count)1896 bbr_log_type_rwnd_collapse(struct tcp_bbr *bbr, int seq, int mode, uint32_t count)
1897 {
1898 if (tcp_bblogging_on(bbr->rc_tp)) {
1899 union tcp_log_stackspecific log;
1900
1901 bbr_fill_in_logging_data(bbr, &log.u_bbr, bbr->r_ctl.rc_rcvtime);
1902 log.u_bbr.flex1 = seq;
1903 log.u_bbr.flex2 = count;
1904 log.u_bbr.flex8 = mode;
1905 TCP_LOG_EVENTP(bbr->rc_tp, NULL,
1906 &bbr->rc_inp->inp_socket->so_rcv,
1907 &bbr->rc_inp->inp_socket->so_snd,
1908 BBR_LOG_LOWGAIN, 0,
1909 0, &log, false, &bbr->rc_tv);
1910 }
1911 }
1912
1913 static void
bbr_log_type_just_return(struct tcp_bbr * bbr,uint32_t cts,uint32_t tlen,uint8_t hpts_calling,uint8_t reason,uint32_t p_maxseg,int len)1914 bbr_log_type_just_return(struct tcp_bbr *bbr, uint32_t cts, uint32_t tlen, uint8_t hpts_calling,
1915 uint8_t reason, uint32_t p_maxseg, int len)
1916 {
1917 if (tcp_bblogging_on(bbr->rc_tp)) {
1918 union tcp_log_stackspecific log;
1919
1920 bbr_fill_in_logging_data(bbr, &log.u_bbr, cts);
1921 log.u_bbr.flex1 = p_maxseg;
1922 log.u_bbr.flex2 = bbr->r_ctl.rc_hpts_flags;
1923 log.u_bbr.flex3 = bbr->r_ctl.rc_timer_exp;
1924 log.u_bbr.flex4 = reason;
1925 log.u_bbr.flex5 = bbr->rc_in_persist;
1926 log.u_bbr.flex6 = bbr->r_ctl.rc_last_delay_val;
1927 log.u_bbr.flex7 = p_maxseg;
1928 log.u_bbr.flex8 = bbr->rc_in_persist;
1929 log.u_bbr.pkts_out = 0;
1930 log.u_bbr.applimited = len;
1931 TCP_LOG_EVENTP(bbr->rc_tp, NULL,
1932 &bbr->rc_inp->inp_socket->so_rcv,
1933 &bbr->rc_inp->inp_socket->so_snd,
1934 BBR_LOG_JUSTRET, 0,
1935 tlen, &log, false, &bbr->rc_tv);
1936 }
1937 }
1938
1939 static void
bbr_log_type_enter_rec(struct tcp_bbr * bbr,uint32_t seq)1940 bbr_log_type_enter_rec(struct tcp_bbr *bbr, uint32_t seq)
1941 {
1942 if (tcp_bblogging_on(bbr->rc_tp)) {
1943 union tcp_log_stackspecific log;
1944
1945 bbr_fill_in_logging_data(bbr, &log.u_bbr, bbr->r_ctl.rc_rcvtime);
1946 log.u_bbr.flex1 = seq;
1947 log.u_bbr.flex2 = bbr->r_ctl.rc_cwnd_on_ent;
1948 log.u_bbr.flex3 = bbr->r_ctl.rc_recovery_start;
1949 TCP_LOG_EVENTP(bbr->rc_tp, NULL,
1950 &bbr->rc_inp->inp_socket->so_rcv,
1951 &bbr->rc_inp->inp_socket->so_snd,
1952 BBR_LOG_ENTREC, 0,
1953 0, &log, false, &bbr->rc_tv);
1954 }
1955 }
1956
1957 static void
bbr_log_msgsize_fail(struct tcp_bbr * bbr,struct tcpcb * tp,uint32_t len,uint32_t maxseg,uint32_t mtu,int32_t csum_flags,int32_t tso,uint32_t cts)1958 bbr_log_msgsize_fail(struct tcp_bbr *bbr, struct tcpcb *tp, uint32_t len, uint32_t maxseg, uint32_t mtu, int32_t csum_flags, int32_t tso, uint32_t cts)
1959 {
1960 if (tcp_bblogging_on(tp)) {
1961 union tcp_log_stackspecific log;
1962
1963 bbr_fill_in_logging_data(bbr, &log.u_bbr, cts);
1964 log.u_bbr.flex1 = tso;
1965 log.u_bbr.flex2 = maxseg;
1966 log.u_bbr.flex3 = mtu;
1967 log.u_bbr.flex4 = csum_flags;
1968 TCP_LOG_EVENTP(tp, NULL,
1969 &bbr->rc_inp->inp_socket->so_rcv,
1970 &bbr->rc_inp->inp_socket->so_snd,
1971 BBR_LOG_MSGSIZE, 0,
1972 0, &log, false, &bbr->rc_tv);
1973 }
1974 }
1975
1976 static void
bbr_log_flowend(struct tcp_bbr * bbr)1977 bbr_log_flowend(struct tcp_bbr *bbr)
1978 {
1979 if (tcp_bblogging_on(bbr->rc_tp)) {
1980 union tcp_log_stackspecific log;
1981 struct sockbuf *r, *s;
1982 struct timeval tv;
1983
1984 if (bbr->rc_inp->inp_socket) {
1985 r = &bbr->rc_inp->inp_socket->so_rcv;
1986 s = &bbr->rc_inp->inp_socket->so_snd;
1987 } else {
1988 r = s = NULL;
1989 }
1990 bbr_fill_in_logging_data(bbr, &log.u_bbr, tcp_get_usecs(&tv));
1991 TCP_LOG_EVENTP(bbr->rc_tp, NULL,
1992 r, s,
1993 TCP_LOG_FLOWEND, 0,
1994 0, &log, false, &tv);
1995 }
1996 }
1997
1998 static void
bbr_log_pkt_epoch(struct tcp_bbr * bbr,uint32_t cts,uint32_t line,uint32_t lost,uint32_t del)1999 bbr_log_pkt_epoch(struct tcp_bbr *bbr, uint32_t cts, uint32_t line,
2000 uint32_t lost, uint32_t del)
2001 {
2002 if (tcp_bblogging_on(bbr->rc_tp)) {
2003 union tcp_log_stackspecific log;
2004
2005 bbr_fill_in_logging_data(bbr, &log.u_bbr, cts);
2006 log.u_bbr.flex1 = lost;
2007 log.u_bbr.flex2 = del;
2008 log.u_bbr.flex3 = bbr->r_ctl.rc_bbr_lastbtlbw;
2009 log.u_bbr.flex4 = bbr->r_ctl.rc_pkt_epoch_rtt;
2010 log.u_bbr.flex5 = bbr->r_ctl.rc_bbr_last_startup_epoch;
2011 log.u_bbr.flex6 = bbr->r_ctl.rc_lost_at_startup;
2012 log.u_bbr.flex7 = line;
2013 log.u_bbr.flex8 = 0;
2014 log.u_bbr.inflight = bbr->r_ctl.r_measurement_count;
2015 TCP_LOG_EVENTP(bbr->rc_tp, NULL,
2016 &bbr->rc_inp->inp_socket->so_rcv,
2017 &bbr->rc_inp->inp_socket->so_snd,
2018 BBR_LOG_PKT_EPOCH, 0,
2019 0, &log, false, &bbr->rc_tv);
2020 }
2021 }
2022
2023 static void
bbr_log_time_epoch(struct tcp_bbr * bbr,uint32_t cts,uint32_t line,uint32_t epoch_time)2024 bbr_log_time_epoch(struct tcp_bbr *bbr, uint32_t cts, uint32_t line, uint32_t epoch_time)
2025 {
2026 if (bbr_verbose_logging && tcp_bblogging_on(bbr->rc_tp)) {
2027 union tcp_log_stackspecific log;
2028
2029 bbr_fill_in_logging_data(bbr, &log.u_bbr, cts);
2030 log.u_bbr.flex1 = bbr->r_ctl.rc_lost;
2031 log.u_bbr.flex2 = bbr->rc_inp->inp_socket->so_snd.sb_lowat;
2032 log.u_bbr.flex3 = bbr->rc_inp->inp_socket->so_snd.sb_hiwat;
2033 log.u_bbr.flex7 = line;
2034 TCP_LOG_EVENTP(bbr->rc_tp, NULL,
2035 &bbr->rc_inp->inp_socket->so_rcv,
2036 &bbr->rc_inp->inp_socket->so_snd,
2037 BBR_LOG_TIME_EPOCH, 0,
2038 0, &log, false, &bbr->rc_tv);
2039 }
2040 }
2041
2042 static void
bbr_log_set_of_state_target(struct tcp_bbr * bbr,uint32_t new_tar,int line,int meth)2043 bbr_log_set_of_state_target(struct tcp_bbr *bbr, uint32_t new_tar, int line, int meth)
2044 {
2045 if (tcp_bblogging_on(bbr->rc_tp)) {
2046 union tcp_log_stackspecific log;
2047
2048 bbr_fill_in_logging_data(bbr, &log.u_bbr, bbr->r_ctl.rc_rcvtime);
2049 log.u_bbr.flex1 = bbr->r_ctl.rc_target_at_state;
2050 log.u_bbr.flex2 = new_tar;
2051 log.u_bbr.flex3 = line;
2052 log.u_bbr.flex4 = bbr->r_ctl.rc_pace_max_segs;
2053 log.u_bbr.flex5 = bbr_quanta;
2054 log.u_bbr.flex6 = bbr->r_ctl.rc_pace_min_segs;
2055 log.u_bbr.flex7 = bbr->rc_last_options;
2056 log.u_bbr.flex8 = meth;
2057 TCP_LOG_EVENTP(bbr->rc_tp, NULL,
2058 &bbr->rc_inp->inp_socket->so_rcv,
2059 &bbr->rc_inp->inp_socket->so_snd,
2060 BBR_LOG_STATE_TARGET, 0,
2061 0, &log, false, &bbr->rc_tv);
2062 }
2063
2064 }
2065
2066 static void
bbr_log_type_statechange(struct tcp_bbr * bbr,uint32_t cts,int32_t line)2067 bbr_log_type_statechange(struct tcp_bbr *bbr, uint32_t cts, int32_t line)
2068 {
2069 if (tcp_bblogging_on(bbr->rc_tp)) {
2070 union tcp_log_stackspecific log;
2071
2072 bbr_fill_in_logging_data(bbr, &log.u_bbr, cts);
2073 log.u_bbr.flex1 = line;
2074 log.u_bbr.flex2 = bbr->r_ctl.rc_rtt_shrinks;
2075 log.u_bbr.flex3 = bbr->r_ctl.rc_probertt_int;
2076 if (bbr_state_is_pkt_epoch)
2077 log.u_bbr.flex4 = bbr_get_rtt(bbr, BBR_RTT_PKTRTT);
2078 else
2079 log.u_bbr.flex4 = bbr_get_rtt(bbr, BBR_RTT_PROP);
2080 log.u_bbr.flex5 = bbr->r_ctl.rc_bbr_last_startup_epoch;
2081 log.u_bbr.flex6 = bbr->r_ctl.rc_lost_at_startup;
2082 log.u_bbr.flex7 = (bbr->r_ctl.rc_target_at_state/1000);
2083 log.u_bbr.lt_epoch = bbr->r_ctl.rc_level_state_extra;
2084 log.u_bbr.pkts_out = bbr->r_ctl.rc_target_at_state;
2085 TCP_LOG_EVENTP(bbr->rc_tp, NULL,
2086 &bbr->rc_inp->inp_socket->so_rcv,
2087 &bbr->rc_inp->inp_socket->so_snd,
2088 BBR_LOG_STATE, 0,
2089 0, &log, false, &bbr->rc_tv);
2090 }
2091 }
2092
2093 static void
bbr_log_rtt_shrinks(struct tcp_bbr * bbr,uint32_t cts,uint32_t applied,uint32_t rtt,uint32_t line,uint8_t reas,uint16_t cond)2094 bbr_log_rtt_shrinks(struct tcp_bbr *bbr, uint32_t cts, uint32_t applied,
2095 uint32_t rtt, uint32_t line, uint8_t reas, uint16_t cond)
2096 {
2097 if (tcp_bblogging_on(bbr->rc_tp)) {
2098 union tcp_log_stackspecific log;
2099
2100 bbr_fill_in_logging_data(bbr, &log.u_bbr, cts);
2101 log.u_bbr.flex1 = line;
2102 log.u_bbr.flex2 = bbr->r_ctl.rc_rtt_shrinks;
2103 log.u_bbr.flex3 = bbr->r_ctl.last_in_probertt;
2104 log.u_bbr.flex4 = applied;
2105 log.u_bbr.flex5 = rtt;
2106 log.u_bbr.flex6 = bbr->r_ctl.rc_target_at_state;
2107 log.u_bbr.flex7 = cond;
2108 log.u_bbr.flex8 = reas;
2109 TCP_LOG_EVENTP(bbr->rc_tp, NULL,
2110 &bbr->rc_inp->inp_socket->so_rcv,
2111 &bbr->rc_inp->inp_socket->so_snd,
2112 BBR_LOG_RTT_SHRINKS, 0,
2113 0, &log, false, &bbr->rc_tv);
2114 }
2115 }
2116
2117 static void
bbr_log_type_exit_rec(struct tcp_bbr * bbr)2118 bbr_log_type_exit_rec(struct tcp_bbr *bbr)
2119 {
2120 if (tcp_bblogging_on(bbr->rc_tp)) {
2121 union tcp_log_stackspecific log;
2122
2123 bbr_fill_in_logging_data(bbr, &log.u_bbr, bbr->r_ctl.rc_rcvtime);
2124 log.u_bbr.flex1 = bbr->r_ctl.rc_recovery_start;
2125 log.u_bbr.flex2 = bbr->r_ctl.rc_cwnd_on_ent;
2126 log.u_bbr.flex5 = bbr->r_ctl.rc_target_at_state;
2127 TCP_LOG_EVENTP(bbr->rc_tp, NULL,
2128 &bbr->rc_inp->inp_socket->so_rcv,
2129 &bbr->rc_inp->inp_socket->so_snd,
2130 BBR_LOG_EXITREC, 0,
2131 0, &log, false, &bbr->rc_tv);
2132 }
2133 }
2134
2135 static void
bbr_log_type_cwndupd(struct tcp_bbr * bbr,uint32_t bytes_this_ack,uint32_t chg,uint32_t prev_acked,int32_t meth,uint32_t target,uint32_t th_ack,int32_t line)2136 bbr_log_type_cwndupd(struct tcp_bbr *bbr, uint32_t bytes_this_ack, uint32_t chg,
2137 uint32_t prev_acked, int32_t meth, uint32_t target, uint32_t th_ack, int32_t line)
2138 {
2139 if (bbr_verbose_logging && tcp_bblogging_on(bbr->rc_tp)) {
2140 union tcp_log_stackspecific log;
2141
2142 bbr_fill_in_logging_data(bbr, &log.u_bbr, bbr->r_ctl.rc_rcvtime);
2143 log.u_bbr.flex1 = line;
2144 log.u_bbr.flex2 = prev_acked;
2145 log.u_bbr.flex3 = bytes_this_ack;
2146 log.u_bbr.flex4 = chg;
2147 log.u_bbr.flex5 = th_ack;
2148 log.u_bbr.flex6 = target;
2149 log.u_bbr.flex8 = meth;
2150 TCP_LOG_EVENTP(bbr->rc_tp, NULL,
2151 &bbr->rc_inp->inp_socket->so_rcv,
2152 &bbr->rc_inp->inp_socket->so_snd,
2153 BBR_LOG_CWND, 0,
2154 0, &log, false, &bbr->rc_tv);
2155 }
2156 }
2157
2158 static void
bbr_log_rtt_sample(struct tcp_bbr * bbr,uint32_t rtt,uint32_t tsin)2159 bbr_log_rtt_sample(struct tcp_bbr *bbr, uint32_t rtt, uint32_t tsin)
2160 {
2161 /*
2162 * Log the rtt sample we are applying to the srtt algorithm in
2163 * useconds.
2164 */
2165 if (tcp_bblogging_on(bbr->rc_tp)) {
2166 union tcp_log_stackspecific log;
2167
2168 bbr_fill_in_logging_data(bbr, &log.u_bbr, bbr->r_ctl.rc_rcvtime);
2169 log.u_bbr.flex1 = rtt;
2170 log.u_bbr.flex2 = bbr->r_ctl.rc_bbr_state_time;
2171 log.u_bbr.flex3 = bbr->r_ctl.rc_ack_hdwr_delay;
2172 log.u_bbr.flex4 = bbr->rc_tp->ts_offset;
2173 log.u_bbr.flex5 = bbr->r_ctl.rc_target_at_state;
2174 log.u_bbr.pkts_out = tcp_tv_to_msec(&bbr->rc_tv);
2175 log.u_bbr.flex6 = tsin;
2176 log.u_bbr.flex7 = 0;
2177 log.u_bbr.flex8 = bbr->rc_ack_was_delayed;
2178 TCP_LOG_EVENTP(bbr->rc_tp, NULL,
2179 &bbr->rc_inp->inp_socket->so_rcv,
2180 &bbr->rc_inp->inp_socket->so_snd,
2181 TCP_LOG_RTT, 0,
2182 0, &log, false, &bbr->rc_tv);
2183 }
2184 }
2185
2186 static void
bbr_log_type_pesist(struct tcp_bbr * bbr,uint32_t cts,uint32_t time_in,int32_t line,uint8_t enter_exit)2187 bbr_log_type_pesist(struct tcp_bbr *bbr, uint32_t cts, uint32_t time_in, int32_t line, uint8_t enter_exit)
2188 {
2189 if (bbr_verbose_logging && tcp_bblogging_on(bbr->rc_tp)) {
2190 union tcp_log_stackspecific log;
2191
2192 bbr_fill_in_logging_data(bbr, &log.u_bbr, cts);
2193 log.u_bbr.flex1 = time_in;
2194 log.u_bbr.flex2 = line;
2195 log.u_bbr.flex8 = enter_exit;
2196 TCP_LOG_EVENTP(bbr->rc_tp, NULL,
2197 &bbr->rc_inp->inp_socket->so_rcv,
2198 &bbr->rc_inp->inp_socket->so_snd,
2199 BBR_LOG_PERSIST, 0,
2200 0, &log, false, &bbr->rc_tv);
2201 }
2202 }
2203 static void
bbr_log_ack_clear(struct tcp_bbr * bbr,uint32_t cts)2204 bbr_log_ack_clear(struct tcp_bbr *bbr, uint32_t cts)
2205 {
2206 if (bbr_verbose_logging && tcp_bblogging_on(bbr->rc_tp)) {
2207 union tcp_log_stackspecific log;
2208
2209 bbr_fill_in_logging_data(bbr, &log.u_bbr, cts);
2210 log.u_bbr.flex1 = bbr->rc_tp->ts_recent_age;
2211 log.u_bbr.flex2 = bbr->r_ctl.rc_rtt_shrinks;
2212 log.u_bbr.flex3 = bbr->r_ctl.rc_probertt_int;
2213 log.u_bbr.flex4 = bbr->r_ctl.rc_went_idle_time;
2214 log.u_bbr.flex5 = bbr->r_ctl.rc_target_at_state;
2215 TCP_LOG_EVENTP(bbr->rc_tp, NULL,
2216 &bbr->rc_inp->inp_socket->so_rcv,
2217 &bbr->rc_inp->inp_socket->so_snd,
2218 BBR_LOG_ACKCLEAR, 0,
2219 0, &log, false, &bbr->rc_tv);
2220 }
2221 }
2222
2223 static void
bbr_log_ack_event(struct tcp_bbr * bbr,struct tcphdr * th,struct tcpopt * to,uint32_t tlen,uint16_t nsegs,uint32_t cts,int32_t nxt_pkt,struct mbuf * m)2224 bbr_log_ack_event(struct tcp_bbr *bbr, struct tcphdr *th, struct tcpopt *to, uint32_t tlen,
2225 uint16_t nsegs, uint32_t cts, int32_t nxt_pkt, struct mbuf *m)
2226 {
2227 if (tcp_bblogging_on(bbr->rc_tp)) {
2228 union tcp_log_stackspecific log;
2229 struct timeval tv;
2230
2231 bbr_fill_in_logging_data(bbr, &log.u_bbr, cts);
2232 log.u_bbr.flex1 = nsegs;
2233 log.u_bbr.flex2 = bbr->r_ctl.rc_lost_bytes;
2234 if (m) {
2235 struct timespec ts;
2236
2237 log.u_bbr.flex3 = m->m_flags;
2238 if (m->m_flags & M_TSTMP) {
2239 mbuf_tstmp2timespec(m, &ts);
2240 tv.tv_sec = ts.tv_sec;
2241 tv.tv_usec = ts.tv_nsec / 1000;
2242 log.u_bbr.lt_epoch = tcp_tv_to_usec(&tv);
2243 } else {
2244 log.u_bbr.lt_epoch = 0;
2245 }
2246 if (m->m_flags & M_TSTMP_LRO) {
2247 mbuf_tstmp2timeval(m, &tv);
2248 log.u_bbr.flex5 = tcp_tv_to_usec(&tv);
2249 } else {
2250 /* No arrival timestamp */
2251 log.u_bbr.flex5 = 0;
2252 }
2253
2254 log.u_bbr.pkts_out = tcp_get_usecs(&tv);
2255 } else {
2256 log.u_bbr.flex3 = 0;
2257 log.u_bbr.flex5 = 0;
2258 log.u_bbr.flex6 = 0;
2259 log.u_bbr.pkts_out = 0;
2260 }
2261 log.u_bbr.flex4 = bbr->r_ctl.rc_target_at_state;
2262 log.u_bbr.flex7 = bbr->r_wanted_output;
2263 log.u_bbr.flex8 = bbr->rc_in_persist;
2264 TCP_LOG_EVENTP(bbr->rc_tp, th,
2265 &bbr->rc_inp->inp_socket->so_rcv,
2266 &bbr->rc_inp->inp_socket->so_snd,
2267 TCP_LOG_IN, 0,
2268 tlen, &log, true, &bbr->rc_tv);
2269 }
2270 }
2271
2272 static void
bbr_log_doseg_done(struct tcp_bbr * bbr,uint32_t cts,int32_t nxt_pkt,int32_t did_out)2273 bbr_log_doseg_done(struct tcp_bbr *bbr, uint32_t cts, int32_t nxt_pkt, int32_t did_out)
2274 {
2275 if (tcp_bblogging_on(bbr->rc_tp)) {
2276 union tcp_log_stackspecific log;
2277
2278 bbr_fill_in_logging_data(bbr, &log.u_bbr, cts);
2279 log.u_bbr.flex1 = did_out;
2280 log.u_bbr.flex2 = nxt_pkt;
2281 log.u_bbr.flex3 = bbr->r_ctl.rc_last_delay_val;
2282 log.u_bbr.flex4 = bbr->r_ctl.rc_hpts_flags;
2283 log.u_bbr.flex5 = bbr->r_ctl.rc_timer_exp;
2284 log.u_bbr.flex6 = bbr->r_ctl.rc_lost_bytes;
2285 log.u_bbr.flex7 = bbr->r_wanted_output;
2286 log.u_bbr.flex8 = bbr->rc_in_persist;
2287 log.u_bbr.pkts_out = bbr->r_ctl.highest_hdwr_delay;
2288 TCP_LOG_EVENTP(bbr->rc_tp, NULL,
2289 &bbr->rc_inp->inp_socket->so_rcv,
2290 &bbr->rc_inp->inp_socket->so_snd,
2291 BBR_LOG_DOSEG_DONE, 0,
2292 0, &log, true, &bbr->rc_tv);
2293 }
2294 }
2295
2296 static void
bbr_log_enobuf_jmp(struct tcp_bbr * bbr,uint32_t len,uint32_t cts,int32_t line,uint32_t o_len,uint32_t segcnt,uint32_t segsiz)2297 bbr_log_enobuf_jmp(struct tcp_bbr *bbr, uint32_t len, uint32_t cts,
2298 int32_t line, uint32_t o_len, uint32_t segcnt, uint32_t segsiz)
2299 {
2300 if (tcp_bblogging_on(bbr->rc_tp)) {
2301 union tcp_log_stackspecific log;
2302
2303 bbr_fill_in_logging_data(bbr, &log.u_bbr, cts);
2304 log.u_bbr.flex1 = line;
2305 log.u_bbr.flex2 = o_len;
2306 log.u_bbr.flex3 = segcnt;
2307 log.u_bbr.flex4 = segsiz;
2308 TCP_LOG_EVENTP(bbr->rc_tp, NULL,
2309 &bbr->rc_inp->inp_socket->so_rcv,
2310 &bbr->rc_inp->inp_socket->so_snd,
2311 BBR_LOG_ENOBUF_JMP, ENOBUFS,
2312 len, &log, true, &bbr->rc_tv);
2313 }
2314 }
2315
2316 static void
bbr_log_to_processing(struct tcp_bbr * bbr,uint32_t cts,int32_t ret,int32_t timers,uint8_t hpts_calling)2317 bbr_log_to_processing(struct tcp_bbr *bbr, uint32_t cts, int32_t ret, int32_t timers, uint8_t hpts_calling)
2318 {
2319 if (tcp_bblogging_on(bbr->rc_tp)) {
2320 union tcp_log_stackspecific log;
2321
2322 bbr_fill_in_logging_data(bbr, &log.u_bbr, cts);
2323 log.u_bbr.flex1 = timers;
2324 log.u_bbr.flex2 = ret;
2325 log.u_bbr.flex3 = bbr->r_ctl.rc_timer_exp;
2326 log.u_bbr.flex4 = bbr->r_ctl.rc_hpts_flags;
2327 log.u_bbr.flex5 = cts;
2328 log.u_bbr.flex6 = bbr->r_ctl.rc_target_at_state;
2329 log.u_bbr.flex8 = hpts_calling;
2330 TCP_LOG_EVENTP(bbr->rc_tp, NULL,
2331 &bbr->rc_inp->inp_socket->so_rcv,
2332 &bbr->rc_inp->inp_socket->so_snd,
2333 BBR_LOG_TO_PROCESS, 0,
2334 0, &log, false, &bbr->rc_tv);
2335 }
2336 }
2337
2338 static void
bbr_log_to_event(struct tcp_bbr * bbr,uint32_t cts,int32_t to_num)2339 bbr_log_to_event(struct tcp_bbr *bbr, uint32_t cts, int32_t to_num)
2340 {
2341 if (tcp_bblogging_on(bbr->rc_tp)) {
2342 union tcp_log_stackspecific log;
2343 uint64_t ar;
2344
2345 bbr_fill_in_logging_data(bbr, &log.u_bbr, cts);
2346 log.u_bbr.flex1 = bbr->bbr_timer_src;
2347 log.u_bbr.flex2 = 0;
2348 log.u_bbr.flex3 = bbr->r_ctl.rc_hpts_flags;
2349 ar = (uintptr_t)(bbr->r_ctl.rc_resend);
2350 ar >>= 32;
2351 ar &= 0x00000000ffffffff;
2352 log.u_bbr.flex4 = (uint32_t)ar;
2353 ar = (uintptr_t)bbr->r_ctl.rc_resend;
2354 ar &= 0x00000000ffffffff;
2355 log.u_bbr.flex5 = (uint32_t)ar;
2356 log.u_bbr.flex6 = TICKS_2_USEC(bbr->rc_tp->t_rxtcur);
2357 log.u_bbr.flex8 = to_num;
2358 TCP_LOG_EVENTP(bbr->rc_tp, NULL,
2359 &bbr->rc_inp->inp_socket->so_rcv,
2360 &bbr->rc_inp->inp_socket->so_snd,
2361 BBR_LOG_RTO, 0,
2362 0, &log, false, &bbr->rc_tv);
2363 }
2364 }
2365
2366 static void
bbr_log_startup_event(struct tcp_bbr * bbr,uint32_t cts,uint32_t flex1,uint32_t flex2,uint32_t flex3,uint8_t reason)2367 bbr_log_startup_event(struct tcp_bbr *bbr, uint32_t cts, uint32_t flex1, uint32_t flex2, uint32_t flex3, uint8_t reason)
2368 {
2369 if (tcp_bblogging_on(bbr->rc_tp)) {
2370 union tcp_log_stackspecific log;
2371
2372 bbr_fill_in_logging_data(bbr, &log.u_bbr, cts);
2373 log.u_bbr.flex1 = flex1;
2374 log.u_bbr.flex2 = flex2;
2375 log.u_bbr.flex3 = flex3;
2376 log.u_bbr.flex4 = 0;
2377 log.u_bbr.flex5 = bbr->r_ctl.rc_target_at_state;
2378 log.u_bbr.flex6 = bbr->r_ctl.rc_lost_at_startup;
2379 log.u_bbr.flex8 = reason;
2380 log.u_bbr.cur_del_rate = bbr->r_ctl.rc_bbr_lastbtlbw;
2381 TCP_LOG_EVENTP(bbr->rc_tp, NULL,
2382 &bbr->rc_inp->inp_socket->so_rcv,
2383 &bbr->rc_inp->inp_socket->so_snd,
2384 BBR_LOG_REDUCE, 0,
2385 0, &log, false, &bbr->rc_tv);
2386 }
2387 }
2388
2389 static void
bbr_log_hpts_diag(struct tcp_bbr * bbr,uint32_t cts,struct hpts_diag * diag)2390 bbr_log_hpts_diag(struct tcp_bbr *bbr, uint32_t cts, struct hpts_diag *diag)
2391 {
2392 if (bbr_verbose_logging && tcp_bblogging_on(bbr->rc_tp)) {
2393 union tcp_log_stackspecific log;
2394
2395 bbr_fill_in_logging_data(bbr, &log.u_bbr, cts);
2396 log.u_bbr.flex1 = diag->p_nxt_slot;
2397 log.u_bbr.flex2 = diag->p_cur_slot;
2398 log.u_bbr.flex3 = diag->slot_req;
2399 log.u_bbr.flex4 = diag->inp_hptsslot;
2400 log.u_bbr.flex5 = diag->slot_remaining;
2401 log.u_bbr.flex6 = diag->need_new_to;
2402 log.u_bbr.flex7 = diag->p_hpts_active;
2403 log.u_bbr.flex8 = diag->p_on_min_sleep;
2404 /* Hijack other fields as needed */
2405 log.u_bbr.epoch = diag->have_slept;
2406 log.u_bbr.lt_epoch = diag->yet_to_sleep;
2407 log.u_bbr.pkts_out = diag->co_ret;
2408 log.u_bbr.applimited = diag->hpts_sleep_time;
2409 log.u_bbr.delivered = diag->p_prev_slot;
2410 log.u_bbr.inflight = diag->p_runningslot;
2411 log.u_bbr.bw_inuse = diag->wheel_slot;
2412 log.u_bbr.rttProp = diag->wheel_cts;
2413 log.u_bbr.delRate = diag->maxslots;
2414 log.u_bbr.cur_del_rate = diag->p_curtick;
2415 log.u_bbr.cur_del_rate <<= 32;
2416 log.u_bbr.cur_del_rate |= diag->p_lasttick;
2417 TCP_LOG_EVENTP(bbr->rc_tp, NULL,
2418 &bbr->rc_inp->inp_socket->so_rcv,
2419 &bbr->rc_inp->inp_socket->so_snd,
2420 BBR_LOG_HPTSDIAG, 0,
2421 0, &log, false, &bbr->rc_tv);
2422 }
2423 }
2424
2425 static void
bbr_log_timer_var(struct tcp_bbr * bbr,int mode,uint32_t cts,uint32_t time_since_sent,uint32_t srtt,uint32_t thresh,uint32_t to)2426 bbr_log_timer_var(struct tcp_bbr *bbr, int mode, uint32_t cts, uint32_t time_since_sent, uint32_t srtt,
2427 uint32_t thresh, uint32_t to)
2428 {
2429 if (bbr_verbose_logging && tcp_bblogging_on(bbr->rc_tp)) {
2430 union tcp_log_stackspecific log;
2431
2432 bbr_fill_in_logging_data(bbr, &log.u_bbr, cts);
2433 log.u_bbr.flex1 = bbr->rc_tp->t_rttvar;
2434 log.u_bbr.flex2 = time_since_sent;
2435 log.u_bbr.flex3 = srtt;
2436 log.u_bbr.flex4 = thresh;
2437 log.u_bbr.flex5 = to;
2438 log.u_bbr.flex6 = bbr->rc_tp->t_srtt;
2439 log.u_bbr.flex8 = mode;
2440 TCP_LOG_EVENTP(bbr->rc_tp, NULL,
2441 &bbr->rc_inp->inp_socket->so_rcv,
2442 &bbr->rc_inp->inp_socket->so_snd,
2443 BBR_LOG_TIMERPREP, 0,
2444 0, &log, false, &bbr->rc_tv);
2445 }
2446 }
2447
2448 static void
bbr_log_pacing_delay_calc(struct tcp_bbr * bbr,uint16_t gain,uint32_t len,uint32_t cts,uint32_t usecs,uint64_t bw,uint32_t override,int mod)2449 bbr_log_pacing_delay_calc(struct tcp_bbr *bbr, uint16_t gain, uint32_t len,
2450 uint32_t cts, uint32_t usecs, uint64_t bw, uint32_t override, int mod)
2451 {
2452 if (tcp_bblogging_on(bbr->rc_tp)) {
2453 union tcp_log_stackspecific log;
2454
2455 bbr_fill_in_logging_data(bbr, &log.u_bbr, cts);
2456 log.u_bbr.flex1 = usecs;
2457 log.u_bbr.flex2 = len;
2458 log.u_bbr.flex3 = (uint32_t)((bw >> 32) & 0x00000000ffffffff);
2459 log.u_bbr.flex4 = (uint32_t)(bw & 0x00000000ffffffff);
2460 if (override)
2461 log.u_bbr.flex5 = (1 << 2);
2462 else
2463 log.u_bbr.flex5 = 0;
2464 log.u_bbr.flex6 = override;
2465 log.u_bbr.flex7 = gain;
2466 log.u_bbr.flex8 = mod;
2467 TCP_LOG_EVENTP(bbr->rc_tp, NULL,
2468 &bbr->rc_inp->inp_socket->so_rcv,
2469 &bbr->rc_inp->inp_socket->so_snd,
2470 BBR_LOG_HPTSI_CALC, 0,
2471 len, &log, false, &bbr->rc_tv);
2472 }
2473 }
2474
2475 static void
bbr_log_to_start(struct tcp_bbr * bbr,uint32_t cts,uint32_t to,int32_t slot,uint8_t which)2476 bbr_log_to_start(struct tcp_bbr *bbr, uint32_t cts, uint32_t to, int32_t slot, uint8_t which)
2477 {
2478 if (tcp_bblogging_on(bbr->rc_tp)) {
2479 union tcp_log_stackspecific log;
2480
2481 bbr_fill_in_logging_data(bbr, &log.u_bbr, cts);
2482
2483 log.u_bbr.flex1 = bbr->bbr_timer_src;
2484 log.u_bbr.flex2 = to;
2485 log.u_bbr.flex3 = bbr->r_ctl.rc_hpts_flags;
2486 log.u_bbr.flex4 = slot;
2487 log.u_bbr.flex5 = bbr->rc_tp->t_hpts_slot;
2488 log.u_bbr.flex6 = TICKS_2_USEC(bbr->rc_tp->t_rxtcur);
2489 log.u_bbr.pkts_out = bbr->rc_tp->t_flags2;
2490 log.u_bbr.flex8 = which;
2491 TCP_LOG_EVENTP(bbr->rc_tp, NULL,
2492 &bbr->rc_inp->inp_socket->so_rcv,
2493 &bbr->rc_inp->inp_socket->so_snd,
2494 BBR_LOG_TIMERSTAR, 0,
2495 0, &log, false, &bbr->rc_tv);
2496 }
2497 }
2498
2499 static void
bbr_log_thresh_choice(struct tcp_bbr * bbr,uint32_t cts,uint32_t thresh,uint32_t lro,uint32_t srtt,struct bbr_sendmap * rsm,uint8_t frm)2500 bbr_log_thresh_choice(struct tcp_bbr *bbr, uint32_t cts, uint32_t thresh, uint32_t lro, uint32_t srtt, struct bbr_sendmap *rsm, uint8_t frm)
2501 {
2502 if (bbr_verbose_logging && tcp_bblogging_on(bbr->rc_tp)) {
2503 union tcp_log_stackspecific log;
2504
2505 bbr_fill_in_logging_data(bbr, &log.u_bbr, cts);
2506 log.u_bbr.flex1 = thresh;
2507 log.u_bbr.flex2 = lro;
2508 log.u_bbr.flex3 = bbr->r_ctl.rc_reorder_ts;
2509 log.u_bbr.flex4 = rsm->r_tim_lastsent[(rsm->r_rtr_cnt - 1)];
2510 log.u_bbr.flex5 = TICKS_2_USEC(bbr->rc_tp->t_rxtcur);
2511 log.u_bbr.flex6 = srtt;
2512 log.u_bbr.flex7 = bbr->r_ctl.rc_reorder_shift;
2513 log.u_bbr.flex8 = frm;
2514 TCP_LOG_EVENTP(bbr->rc_tp, NULL,
2515 &bbr->rc_inp->inp_socket->so_rcv,
2516 &bbr->rc_inp->inp_socket->so_snd,
2517 BBR_LOG_THRESH_CALC, 0,
2518 0, &log, false, &bbr->rc_tv);
2519 }
2520 }
2521
2522 static void
bbr_log_to_cancel(struct tcp_bbr * bbr,int32_t line,uint32_t cts,uint8_t hpts_removed)2523 bbr_log_to_cancel(struct tcp_bbr *bbr, int32_t line, uint32_t cts, uint8_t hpts_removed)
2524 {
2525 if (tcp_bblogging_on(bbr->rc_tp)) {
2526 union tcp_log_stackspecific log;
2527
2528 bbr_fill_in_logging_data(bbr, &log.u_bbr, cts);
2529 log.u_bbr.flex1 = line;
2530 log.u_bbr.flex2 = bbr->bbr_timer_src;
2531 log.u_bbr.flex3 = bbr->r_ctl.rc_hpts_flags;
2532 log.u_bbr.flex4 = bbr->rc_in_persist;
2533 log.u_bbr.flex5 = bbr->r_ctl.rc_target_at_state;
2534 log.u_bbr.flex6 = TICKS_2_USEC(bbr->rc_tp->t_rxtcur);
2535 log.u_bbr.flex8 = hpts_removed;
2536 log.u_bbr.pkts_out = bbr->rc_pacer_started;
2537 TCP_LOG_EVENTP(bbr->rc_tp, NULL,
2538 &bbr->rc_inp->inp_socket->so_rcv,
2539 &bbr->rc_inp->inp_socket->so_snd,
2540 BBR_LOG_TIMERCANC, 0,
2541 0, &log, false, &bbr->rc_tv);
2542 }
2543 }
2544
2545 static void
bbr_log_tstmp_validation(struct tcp_bbr * bbr,uint64_t peer_delta,uint64_t delta)2546 bbr_log_tstmp_validation(struct tcp_bbr *bbr, uint64_t peer_delta, uint64_t delta)
2547 {
2548 if (tcp_bblogging_on(bbr->rc_tp)) {
2549 union tcp_log_stackspecific log;
2550
2551 bbr_fill_in_logging_data(bbr, &log.u_bbr, bbr->r_ctl.rc_rcvtime);
2552 log.u_bbr.flex1 = bbr->r_ctl.bbr_peer_tsratio;
2553 log.u_bbr.flex2 = (peer_delta >> 32);
2554 log.u_bbr.flex3 = (peer_delta & 0x00000000ffffffff);
2555 log.u_bbr.flex4 = (delta >> 32);
2556 log.u_bbr.flex5 = (delta & 0x00000000ffffffff);
2557 log.u_bbr.flex7 = bbr->rc_ts_clock_set;
2558 log.u_bbr.flex8 = bbr->rc_ts_cant_be_used;
2559 TCP_LOG_EVENTP(bbr->rc_tp, NULL,
2560 &bbr->rc_inp->inp_socket->so_rcv,
2561 &bbr->rc_inp->inp_socket->so_snd,
2562 BBR_LOG_TSTMP_VAL, 0,
2563 0, &log, false, &bbr->rc_tv);
2564 }
2565 }
2566
2567 static void
bbr_log_type_tsosize(struct tcp_bbr * bbr,uint32_t cts,uint32_t tsosz,uint32_t tls,uint32_t old_val,uint32_t maxseg,int hdwr)2568 bbr_log_type_tsosize(struct tcp_bbr *bbr, uint32_t cts, uint32_t tsosz, uint32_t tls, uint32_t old_val, uint32_t maxseg, int hdwr)
2569 {
2570 if (tcp_bblogging_on(bbr->rc_tp)) {
2571 union tcp_log_stackspecific log;
2572
2573 bbr_fill_in_logging_data(bbr, &log.u_bbr, cts);
2574 log.u_bbr.flex1 = tsosz;
2575 log.u_bbr.flex2 = tls;
2576 log.u_bbr.flex3 = tcp_min_hptsi_time;
2577 log.u_bbr.flex4 = bbr->r_ctl.bbr_hptsi_bytes_min;
2578 log.u_bbr.flex5 = old_val;
2579 log.u_bbr.flex6 = maxseg;
2580 log.u_bbr.flex7 = bbr->rc_no_pacing;
2581 log.u_bbr.flex7 <<= 1;
2582 log.u_bbr.flex7 |= bbr->rc_past_init_win;
2583 if (hdwr)
2584 log.u_bbr.flex8 = 0x80 | bbr->rc_use_google;
2585 else
2586 log.u_bbr.flex8 = bbr->rc_use_google;
2587 TCP_LOG_EVENTP(bbr->rc_tp, NULL,
2588 &bbr->rc_inp->inp_socket->so_rcv,
2589 &bbr->rc_inp->inp_socket->so_snd,
2590 BBR_LOG_BBRTSO, 0,
2591 0, &log, false, &bbr->rc_tv);
2592 }
2593 }
2594
2595 static void
bbr_log_type_rsmclear(struct tcp_bbr * bbr,uint32_t cts,struct bbr_sendmap * rsm,uint32_t flags,uint32_t line)2596 bbr_log_type_rsmclear(struct tcp_bbr *bbr, uint32_t cts, struct bbr_sendmap *rsm,
2597 uint32_t flags, uint32_t line)
2598 {
2599 if (tcp_bblogging_on(bbr->rc_tp)) {
2600 union tcp_log_stackspecific log;
2601
2602 bbr_fill_in_logging_data(bbr, &log.u_bbr, cts);
2603 log.u_bbr.flex1 = line;
2604 log.u_bbr.flex2 = rsm->r_start;
2605 log.u_bbr.flex3 = rsm->r_end;
2606 log.u_bbr.flex4 = rsm->r_delivered;
2607 log.u_bbr.flex5 = rsm->r_rtr_cnt;
2608 log.u_bbr.flex6 = rsm->r_dupack;
2609 log.u_bbr.flex7 = rsm->r_tim_lastsent[0];
2610 log.u_bbr.flex8 = rsm->r_flags;
2611 /* Hijack the pkts_out fids */
2612 log.u_bbr.applimited = flags;
2613 TCP_LOG_EVENTP(bbr->rc_tp, NULL,
2614 &bbr->rc_inp->inp_socket->so_rcv,
2615 &bbr->rc_inp->inp_socket->so_snd,
2616 BBR_RSM_CLEARED, 0,
2617 0, &log, false, &bbr->rc_tv);
2618 }
2619 }
2620
2621 static void
bbr_log_type_bbrupd(struct tcp_bbr * bbr,uint8_t flex8,uint32_t cts,uint32_t flex3,uint32_t flex2,uint32_t flex5,uint32_t flex6,uint32_t pkts_out,int flex7,uint32_t flex4,uint32_t flex1)2622 bbr_log_type_bbrupd(struct tcp_bbr *bbr, uint8_t flex8, uint32_t cts,
2623 uint32_t flex3, uint32_t flex2, uint32_t flex5,
2624 uint32_t flex6, uint32_t pkts_out, int flex7,
2625 uint32_t flex4, uint32_t flex1)
2626 {
2627
2628 if (tcp_bblogging_on(bbr->rc_tp)) {
2629 union tcp_log_stackspecific log;
2630
2631 bbr_fill_in_logging_data(bbr, &log.u_bbr, cts);
2632 log.u_bbr.flex1 = flex1;
2633 log.u_bbr.flex2 = flex2;
2634 log.u_bbr.flex3 = flex3;
2635 log.u_bbr.flex4 = flex4;
2636 log.u_bbr.flex5 = flex5;
2637 log.u_bbr.flex6 = flex6;
2638 log.u_bbr.flex7 = flex7;
2639 /* Hijack the pkts_out fids */
2640 log.u_bbr.pkts_out = pkts_out;
2641 log.u_bbr.flex8 = flex8;
2642 if (bbr->rc_ack_was_delayed)
2643 log.u_bbr.epoch = bbr->r_ctl.rc_ack_hdwr_delay;
2644 else
2645 log.u_bbr.epoch = 0;
2646 TCP_LOG_EVENTP(bbr->rc_tp, NULL,
2647 &bbr->rc_inp->inp_socket->so_rcv,
2648 &bbr->rc_inp->inp_socket->so_snd,
2649 BBR_LOG_BBRUPD, 0,
2650 flex2, &log, false, &bbr->rc_tv);
2651 }
2652 }
2653
2654 static void
bbr_log_type_ltbw(struct tcp_bbr * bbr,uint32_t cts,int32_t reason,uint32_t newbw,uint32_t obw,uint32_t diff,uint32_t tim)2655 bbr_log_type_ltbw(struct tcp_bbr *bbr, uint32_t cts, int32_t reason,
2656 uint32_t newbw, uint32_t obw, uint32_t diff,
2657 uint32_t tim)
2658 {
2659 if (/*bbr_verbose_logging && */tcp_bblogging_on(bbr->rc_tp)) {
2660 union tcp_log_stackspecific log;
2661
2662 bbr_fill_in_logging_data(bbr, &log.u_bbr, cts);
2663 log.u_bbr.flex1 = reason;
2664 log.u_bbr.flex2 = newbw;
2665 log.u_bbr.flex3 = obw;
2666 log.u_bbr.flex4 = diff;
2667 log.u_bbr.flex5 = bbr->r_ctl.rc_lt_lost;
2668 log.u_bbr.flex6 = bbr->r_ctl.rc_lt_del;
2669 log.u_bbr.flex7 = bbr->rc_lt_is_sampling;
2670 log.u_bbr.pkts_out = tim;
2671 log.u_bbr.bw_inuse = bbr->r_ctl.rc_lt_bw;
2672 if (bbr->rc_lt_use_bw == 0)
2673 log.u_bbr.epoch = bbr->r_ctl.rc_pkt_epoch - bbr->r_ctl.rc_lt_epoch;
2674 else
2675 log.u_bbr.epoch = bbr->r_ctl.rc_pkt_epoch - bbr->r_ctl.rc_lt_epoch_use;
2676 TCP_LOG_EVENTP(bbr->rc_tp, NULL,
2677 &bbr->rc_inp->inp_socket->so_rcv,
2678 &bbr->rc_inp->inp_socket->so_snd,
2679 BBR_LOG_BWSAMP, 0,
2680 0, &log, false, &bbr->rc_tv);
2681 }
2682 }
2683
2684 static inline void
bbr_log_progress_event(struct tcp_bbr * bbr,struct tcpcb * tp,uint32_t tick,int event,int line)2685 bbr_log_progress_event(struct tcp_bbr *bbr, struct tcpcb *tp, uint32_t tick, int event, int line)
2686 {
2687 if (bbr_verbose_logging && tcp_bblogging_on(bbr->rc_tp)) {
2688 union tcp_log_stackspecific log;
2689
2690 bbr_fill_in_logging_data(bbr, &log.u_bbr, bbr->r_ctl.rc_rcvtime);
2691 log.u_bbr.flex1 = line;
2692 log.u_bbr.flex2 = tick;
2693 log.u_bbr.flex3 = tp->t_maxunacktime;
2694 log.u_bbr.flex4 = tp->t_acktime;
2695 log.u_bbr.flex8 = event;
2696 TCP_LOG_EVENTP(bbr->rc_tp, NULL,
2697 &bbr->rc_inp->inp_socket->so_rcv,
2698 &bbr->rc_inp->inp_socket->so_snd,
2699 BBR_LOG_PROGRESS, 0,
2700 0, &log, false, &bbr->rc_tv);
2701 }
2702 }
2703
2704 static void
bbr_type_log_hdwr_pacing(struct tcp_bbr * bbr,const struct ifnet * ifp,uint64_t rate,uint64_t hw_rate,int line,uint32_t cts,int error)2705 bbr_type_log_hdwr_pacing(struct tcp_bbr *bbr, const struct ifnet *ifp,
2706 uint64_t rate, uint64_t hw_rate, int line, uint32_t cts,
2707 int error)
2708 {
2709 if (tcp_bblogging_on(bbr->rc_tp)) {
2710 union tcp_log_stackspecific log;
2711 uint64_t ifp64 = (uintptr_t)ifp;
2712
2713 bbr_fill_in_logging_data(bbr, &log.u_bbr, cts);
2714 log.u_bbr.flex1 = ((hw_rate >> 32) & 0x00000000ffffffff);
2715 log.u_bbr.flex2 = (hw_rate & 0x00000000ffffffff);
2716 log.u_bbr.flex3 = ((ifp64 >> 32) & 0x00000000ffffffff);
2717 log.u_bbr.flex4 = (ifp64 & 0x00000000ffffffff);
2718 log.u_bbr.bw_inuse = rate;
2719 log.u_bbr.flex5 = line;
2720 log.u_bbr.flex6 = error;
2721 log.u_bbr.flex8 = bbr->skip_gain;
2722 log.u_bbr.flex8 <<= 1;
2723 log.u_bbr.flex8 |= bbr->gain_is_limited;
2724 log.u_bbr.flex8 <<= 1;
2725 log.u_bbr.flex8 |= bbr->bbr_hdrw_pacing;
2726 log.u_bbr.pkts_out = bbr->rc_tp->t_maxseg;
2727 TCP_LOG_EVENTP(bbr->rc_tp, NULL,
2728 &bbr->rc_inp->inp_socket->so_rcv,
2729 &bbr->rc_inp->inp_socket->so_snd,
2730 BBR_LOG_HDWR_PACE, 0,
2731 0, &log, false, &bbr->rc_tv);
2732 }
2733 }
2734
2735 static void
bbr_log_type_bbrsnd(struct tcp_bbr * bbr,uint32_t len,uint32_t slot,uint32_t del_by,uint32_t cts,uint32_t line,uint32_t prev_delay)2736 bbr_log_type_bbrsnd(struct tcp_bbr *bbr, uint32_t len, uint32_t slot, uint32_t del_by, uint32_t cts, uint32_t line, uint32_t prev_delay)
2737 {
2738 if (tcp_bblogging_on(bbr->rc_tp)) {
2739 union tcp_log_stackspecific log;
2740
2741 bbr_fill_in_logging_data(bbr, &log.u_bbr, cts);
2742 log.u_bbr.flex1 = slot;
2743 log.u_bbr.flex2 = del_by;
2744 log.u_bbr.flex3 = prev_delay;
2745 log.u_bbr.flex4 = line;
2746 log.u_bbr.flex5 = bbr->r_ctl.rc_last_delay_val;
2747 log.u_bbr.flex6 = bbr->r_ctl.rc_hptsi_agg_delay;
2748 log.u_bbr.flex7 = (0x0000ffff & bbr->r_ctl.rc_hpts_flags);
2749 log.u_bbr.flex8 = bbr->rc_in_persist;
2750 TCP_LOG_EVENTP(bbr->rc_tp, NULL,
2751 &bbr->rc_inp->inp_socket->so_rcv,
2752 &bbr->rc_inp->inp_socket->so_snd,
2753 BBR_LOG_BBRSND, 0,
2754 len, &log, false, &bbr->rc_tv);
2755 }
2756 }
2757
2758 static void
bbr_log_type_bbrrttprop(struct tcp_bbr * bbr,uint32_t t,uint32_t end,uint32_t tsconv,uint32_t cts,int32_t match,uint32_t seq,uint8_t flags)2759 bbr_log_type_bbrrttprop(struct tcp_bbr *bbr, uint32_t t, uint32_t end, uint32_t tsconv, uint32_t cts, int32_t match, uint32_t seq, uint8_t flags)
2760 {
2761 if (tcp_bblogging_on(bbr->rc_tp)) {
2762 union tcp_log_stackspecific log;
2763
2764 bbr_fill_in_logging_data(bbr, &log.u_bbr, cts);
2765 log.u_bbr.flex1 = bbr->r_ctl.rc_delivered;
2766 log.u_bbr.flex2 = 0;
2767 log.u_bbr.flex3 = bbr->r_ctl.rc_lowest_rtt;
2768 log.u_bbr.flex4 = end;
2769 log.u_bbr.flex5 = seq;
2770 log.u_bbr.flex6 = t;
2771 log.u_bbr.flex7 = match;
2772 log.u_bbr.flex8 = flags;
2773 TCP_LOG_EVENTP(bbr->rc_tp, NULL,
2774 &bbr->rc_inp->inp_socket->so_rcv,
2775 &bbr->rc_inp->inp_socket->so_snd,
2776 BBR_LOG_BBRRTT, 0,
2777 0, &log, false, &bbr->rc_tv);
2778 }
2779 }
2780
2781 static void
bbr_log_exit_gain(struct tcp_bbr * bbr,uint32_t cts,int32_t entry_method)2782 bbr_log_exit_gain(struct tcp_bbr *bbr, uint32_t cts, int32_t entry_method)
2783 {
2784 if (tcp_bblogging_on(bbr->rc_tp)) {
2785 union tcp_log_stackspecific log;
2786
2787 bbr_fill_in_logging_data(bbr, &log.u_bbr, cts);
2788 log.u_bbr.flex1 = bbr->r_ctl.rc_target_at_state;
2789 log.u_bbr.flex2 = (bbr->rc_tp->t_maxseg - bbr->rc_last_options);
2790 log.u_bbr.flex3 = bbr->r_ctl.gain_epoch;
2791 log.u_bbr.flex4 = bbr->r_ctl.rc_pace_max_segs;
2792 log.u_bbr.flex5 = bbr->r_ctl.rc_pace_min_segs;
2793 log.u_bbr.flex6 = bbr->r_ctl.rc_bbr_state_atflight;
2794 log.u_bbr.flex7 = 0;
2795 log.u_bbr.flex8 = entry_method;
2796 TCP_LOG_EVENTP(bbr->rc_tp, NULL,
2797 &bbr->rc_inp->inp_socket->so_rcv,
2798 &bbr->rc_inp->inp_socket->so_snd,
2799 BBR_LOG_EXIT_GAIN, 0,
2800 0, &log, false, &bbr->rc_tv);
2801 }
2802 }
2803
2804 static void
bbr_log_settings_change(struct tcp_bbr * bbr,int settings_desired)2805 bbr_log_settings_change(struct tcp_bbr *bbr, int settings_desired)
2806 {
2807 if (bbr_verbose_logging && tcp_bblogging_on(bbr->rc_tp)) {
2808 union tcp_log_stackspecific log;
2809
2810 bbr_fill_in_logging_data(bbr, &log.u_bbr, bbr->r_ctl.rc_rcvtime);
2811 /* R-HU */
2812 log.u_bbr.flex1 = 0;
2813 log.u_bbr.flex2 = 0;
2814 log.u_bbr.flex3 = 0;
2815 log.u_bbr.flex4 = 0;
2816 log.u_bbr.flex7 = 0;
2817 log.u_bbr.flex8 = settings_desired;
2818
2819 TCP_LOG_EVENTP(bbr->rc_tp, NULL,
2820 &bbr->rc_inp->inp_socket->so_rcv,
2821 &bbr->rc_inp->inp_socket->so_snd,
2822 BBR_LOG_SETTINGS_CHG, 0,
2823 0, &log, false, &bbr->rc_tv);
2824 }
2825 }
2826
2827 /*
2828 * Returns the bw from the our filter.
2829 */
2830 static inline uint64_t
bbr_get_full_bw(struct tcp_bbr * bbr)2831 bbr_get_full_bw(struct tcp_bbr *bbr)
2832 {
2833 uint64_t bw;
2834
2835 bw = get_filter_value(&bbr->r_ctl.rc_delrate);
2836
2837 return (bw);
2838 }
2839
2840 static inline void
bbr_set_pktepoch(struct tcp_bbr * bbr,uint32_t cts,int32_t line)2841 bbr_set_pktepoch(struct tcp_bbr *bbr, uint32_t cts, int32_t line)
2842 {
2843 uint64_t calclr;
2844 uint32_t lost, del;
2845
2846 if (bbr->r_ctl.rc_lost > bbr->r_ctl.rc_lost_at_pktepoch)
2847 lost = bbr->r_ctl.rc_lost - bbr->r_ctl.rc_lost_at_pktepoch;
2848 else
2849 lost = 0;
2850 del = bbr->r_ctl.rc_delivered - bbr->r_ctl.rc_pkt_epoch_del;
2851 if (lost == 0) {
2852 calclr = 0;
2853 } else if (del) {
2854 calclr = lost;
2855 calclr *= (uint64_t)1000;
2856 calclr /= (uint64_t)del;
2857 } else {
2858 /* Nothing delivered? 100.0% loss */
2859 calclr = 1000;
2860 }
2861 bbr->r_ctl.rc_pkt_epoch_loss_rate = (uint32_t)calclr;
2862 if (IN_RECOVERY(bbr->rc_tp->t_flags))
2863 bbr->r_ctl.recovery_lr += (uint32_t)calclr;
2864 bbr->r_ctl.rc_pkt_epoch++;
2865 if (bbr->rc_no_pacing &&
2866 (bbr->r_ctl.rc_pkt_epoch >= bbr->no_pacing_until)) {
2867 bbr->rc_no_pacing = 0;
2868 tcp_bbr_tso_size_check(bbr, cts);
2869 }
2870 bbr->r_ctl.rc_pkt_epoch_rtt = bbr_calc_time(cts, bbr->r_ctl.rc_pkt_epoch_time);
2871 bbr->r_ctl.rc_pkt_epoch_time = cts;
2872 /* What was our loss rate */
2873 bbr_log_pkt_epoch(bbr, cts, line, lost, del);
2874 bbr->r_ctl.rc_pkt_epoch_del = bbr->r_ctl.rc_delivered;
2875 bbr->r_ctl.rc_lost_at_pktepoch = bbr->r_ctl.rc_lost;
2876 }
2877
2878 static inline void
bbr_set_epoch(struct tcp_bbr * bbr,uint32_t cts,int32_t line)2879 bbr_set_epoch(struct tcp_bbr *bbr, uint32_t cts, int32_t line)
2880 {
2881 uint32_t epoch_time;
2882
2883 /* Tick the RTT clock */
2884 bbr->r_ctl.rc_rtt_epoch++;
2885 epoch_time = cts - bbr->r_ctl.rc_rcv_epoch_start;
2886 bbr_log_time_epoch(bbr, cts, line, epoch_time);
2887 bbr->r_ctl.rc_rcv_epoch_start = cts;
2888 }
2889
2890 static inline void
bbr_isit_a_pkt_epoch(struct tcp_bbr * bbr,uint32_t cts,struct bbr_sendmap * rsm,int32_t line,int32_t cum_acked)2891 bbr_isit_a_pkt_epoch(struct tcp_bbr *bbr, uint32_t cts, struct bbr_sendmap *rsm, int32_t line, int32_t cum_acked)
2892 {
2893 if (SEQ_GEQ(rsm->r_delivered, bbr->r_ctl.rc_pkt_epoch_del)) {
2894 bbr->rc_is_pkt_epoch_now = 1;
2895 }
2896 }
2897
2898 /*
2899 * Returns the bw from either the b/w filter
2900 * or from the lt_bw (if the connection is being
2901 * policed).
2902 */
2903 static inline uint64_t
__bbr_get_bw(struct tcp_bbr * bbr)2904 __bbr_get_bw(struct tcp_bbr *bbr)
2905 {
2906 uint64_t bw, min_bw;
2907 uint64_t rtt;
2908 int gm_measure_cnt = 1;
2909
2910 /*
2911 * For startup we make, like google, a
2912 * minimum b/w. This is generated from the
2913 * IW and the rttProp. We do fall back to srtt
2914 * if for some reason (initial handshake) we don't
2915 * have a rttProp. We, in the worst case, fall back
2916 * to the configured min_bw (rc_initial_hptsi_bw).
2917 */
2918 if (bbr->rc_bbr_state == BBR_STATE_STARTUP) {
2919 /* Attempt first to use rttProp */
2920 rtt = (uint64_t)get_filter_value_small(&bbr->r_ctl.rc_rttprop);
2921 if (rtt && (rtt < 0xffffffff)) {
2922 measure:
2923 min_bw = (uint64_t)(bbr_initial_cwnd(bbr, bbr->rc_tp)) *
2924 ((uint64_t)1000000);
2925 min_bw /= rtt;
2926 if (min_bw < bbr->r_ctl.rc_initial_hptsi_bw) {
2927 min_bw = bbr->r_ctl.rc_initial_hptsi_bw;
2928 }
2929
2930 } else if (bbr->rc_tp->t_srtt != 0) {
2931 /* No rttProp, use srtt? */
2932 rtt = bbr_get_rtt(bbr, BBR_SRTT);
2933 goto measure;
2934 } else {
2935 min_bw = bbr->r_ctl.rc_initial_hptsi_bw;
2936 }
2937 } else
2938 min_bw = 0;
2939
2940 if ((bbr->rc_past_init_win == 0) &&
2941 (bbr->r_ctl.rc_delivered > bbr_initial_cwnd(bbr, bbr->rc_tp)))
2942 bbr->rc_past_init_win = 1;
2943 if ((bbr->rc_use_google) && (bbr->r_ctl.r_measurement_count >= 1))
2944 gm_measure_cnt = 0;
2945 if (gm_measure_cnt &&
2946 ((bbr->r_ctl.r_measurement_count < bbr_min_measurements_req) ||
2947 (bbr->rc_past_init_win == 0))) {
2948 /* For google we use our guess rate until we get 1 measurement */
2949
2950 use_initial_window:
2951 rtt = (uint64_t)get_filter_value_small(&bbr->r_ctl.rc_rttprop);
2952 if (rtt && (rtt < 0xffffffff)) {
2953 /*
2954 * We have an RTT measurement. Use that in
2955 * combination with our initial window to calculate
2956 * a b/w.
2957 */
2958 bw = (uint64_t)(bbr_initial_cwnd(bbr, bbr->rc_tp)) *
2959 ((uint64_t)1000000);
2960 bw /= rtt;
2961 if (bw < bbr->r_ctl.rc_initial_hptsi_bw) {
2962 bw = bbr->r_ctl.rc_initial_hptsi_bw;
2963 }
2964 } else {
2965 /* Drop back to the 40 and punt to a default */
2966 bw = bbr->r_ctl.rc_initial_hptsi_bw;
2967 }
2968 if (bw < 1)
2969 /* Probably should panic */
2970 bw = 1;
2971 if (bw > min_bw)
2972 return (bw);
2973 else
2974 return (min_bw);
2975 }
2976 if (bbr->rc_lt_use_bw)
2977 bw = bbr->r_ctl.rc_lt_bw;
2978 else if (bbr->r_recovery_bw && (bbr->rc_use_google == 0))
2979 bw = bbr->r_ctl.red_bw;
2980 else
2981 bw = get_filter_value(&bbr->r_ctl.rc_delrate);
2982 if (bw == 0) {
2983 /* We should not be at 0, go to the initial window then */
2984 goto use_initial_window;
2985 }
2986 if (bw < min_bw)
2987 bw = min_bw;
2988 return (bw);
2989 }
2990
2991 static inline uint64_t
bbr_get_bw(struct tcp_bbr * bbr)2992 bbr_get_bw(struct tcp_bbr *bbr)
2993 {
2994 uint64_t bw;
2995
2996 bw = __bbr_get_bw(bbr);
2997 return (bw);
2998 }
2999
3000 static inline void
bbr_reset_lt_bw_interval(struct tcp_bbr * bbr,uint32_t cts)3001 bbr_reset_lt_bw_interval(struct tcp_bbr *bbr, uint32_t cts)
3002 {
3003 bbr->r_ctl.rc_lt_epoch = bbr->r_ctl.rc_pkt_epoch;
3004 bbr->r_ctl.rc_lt_time = bbr->r_ctl.rc_del_time;
3005 bbr->r_ctl.rc_lt_del = bbr->r_ctl.rc_delivered;
3006 bbr->r_ctl.rc_lt_lost = bbr->r_ctl.rc_lost;
3007 }
3008
3009 static inline void
bbr_reset_lt_bw_sampling(struct tcp_bbr * bbr,uint32_t cts)3010 bbr_reset_lt_bw_sampling(struct tcp_bbr *bbr, uint32_t cts)
3011 {
3012 bbr->rc_lt_is_sampling = 0;
3013 bbr->rc_lt_use_bw = 0;
3014 bbr->r_ctl.rc_lt_bw = 0;
3015 bbr_reset_lt_bw_interval(bbr, cts);
3016 }
3017
3018 static inline void
bbr_lt_bw_samp_done(struct tcp_bbr * bbr,uint64_t bw,uint32_t cts,uint32_t timin)3019 bbr_lt_bw_samp_done(struct tcp_bbr *bbr, uint64_t bw, uint32_t cts, uint32_t timin)
3020 {
3021 uint64_t diff;
3022
3023 /* Do we have a previous sample? */
3024 if (bbr->r_ctl.rc_lt_bw) {
3025 /* Get the diff in bytes per second */
3026 if (bbr->r_ctl.rc_lt_bw > bw)
3027 diff = bbr->r_ctl.rc_lt_bw - bw;
3028 else
3029 diff = bw - bbr->r_ctl.rc_lt_bw;
3030 if ((diff <= bbr_lt_bw_diff) ||
3031 (diff <= (bbr->r_ctl.rc_lt_bw / bbr_lt_bw_ratio))) {
3032 /* Consider us policed */
3033 uint32_t saved_bw;
3034
3035 saved_bw = (uint32_t)bbr->r_ctl.rc_lt_bw;
3036 bbr->r_ctl.rc_lt_bw = (bw + bbr->r_ctl.rc_lt_bw) / 2; /* average of two */
3037 bbr->rc_lt_use_bw = 1;
3038 bbr->r_ctl.rc_bbr_hptsi_gain = BBR_UNIT;
3039 /*
3040 * Use pkt based epoch for measuring length of
3041 * policer up
3042 */
3043 bbr->r_ctl.rc_lt_epoch_use = bbr->r_ctl.rc_pkt_epoch;
3044 /*
3045 * reason 4 is we need to start consider being
3046 * policed
3047 */
3048 bbr_log_type_ltbw(bbr, cts, 4, (uint32_t)bw, saved_bw, (uint32_t)diff, timin);
3049 return;
3050 }
3051 }
3052 bbr->r_ctl.rc_lt_bw = bw;
3053 bbr_reset_lt_bw_interval(bbr, cts);
3054 bbr_log_type_ltbw(bbr, cts, 5, 0, (uint32_t)bw, 0, timin);
3055 }
3056
3057 static void
bbr_randomize_extra_state_time(struct tcp_bbr * bbr)3058 bbr_randomize_extra_state_time(struct tcp_bbr *bbr)
3059 {
3060 uint32_t ran, deduct;
3061
3062 ran = arc4random_uniform(bbr_rand_ot);
3063 if (ran) {
3064 deduct = bbr->r_ctl.rc_level_state_extra / ran;
3065 bbr->r_ctl.rc_level_state_extra -= deduct;
3066 }
3067 }
3068 /*
3069 * Return randomly the starting state
3070 * to use in probebw.
3071 */
3072 static uint8_t
bbr_pick_probebw_substate(struct tcp_bbr * bbr,uint32_t cts)3073 bbr_pick_probebw_substate(struct tcp_bbr *bbr, uint32_t cts)
3074 {
3075 uint32_t ran;
3076 uint8_t ret_val;
3077
3078 /* Initialize the offset to 0 */
3079 bbr->r_ctl.rc_exta_time_gd = 0;
3080 bbr->rc_hit_state_1 = 0;
3081 bbr->r_ctl.rc_level_state_extra = 0;
3082 ran = arc4random_uniform((BBR_SUBSTATE_COUNT-1));
3083 /*
3084 * The math works funny here :) the return value is used to set the
3085 * substate and then the state change is called which increments by
3086 * one. So if we return 1 (DRAIN) we will increment to 2 (LEVEL1) when
3087 * we fully enter the state. Note that the (8 - 1 - ran) assures that
3088 * we return 1 - 7, so we dont return 0 and end up starting in
3089 * state 1 (DRAIN).
3090 */
3091 ret_val = BBR_SUBSTATE_COUNT - 1 - ran;
3092 /* Set an epoch */
3093 if ((cts - bbr->r_ctl.rc_rcv_epoch_start) >= bbr_get_rtt(bbr, BBR_RTT_PROP))
3094 bbr_set_epoch(bbr, cts, __LINE__);
3095
3096 bbr->r_ctl.bbr_lost_at_state = bbr->r_ctl.rc_lost;
3097 return (ret_val);
3098 }
3099
3100 static void
bbr_lt_bw_sampling(struct tcp_bbr * bbr,uint32_t cts,int32_t loss_detected)3101 bbr_lt_bw_sampling(struct tcp_bbr *bbr, uint32_t cts, int32_t loss_detected)
3102 {
3103 uint32_t diff, d_time;
3104 uint64_t del_time, bw, lost, delivered;
3105
3106 if (bbr->r_use_policer == 0)
3107 return;
3108 if (bbr->rc_lt_use_bw) {
3109 /* We are using lt bw do we stop yet? */
3110 diff = bbr->r_ctl.rc_pkt_epoch - bbr->r_ctl.rc_lt_epoch_use;
3111 if (diff > bbr_lt_bw_max_rtts) {
3112 /* Reset it all */
3113 reset_all:
3114 bbr_reset_lt_bw_sampling(bbr, cts);
3115 if (bbr->rc_filled_pipe) {
3116 bbr_set_epoch(bbr, cts, __LINE__);
3117 bbr->rc_bbr_substate = bbr_pick_probebw_substate(bbr, cts);
3118 bbr_substate_change(bbr, cts, __LINE__, 0);
3119 bbr->rc_bbr_state = BBR_STATE_PROBE_BW;
3120 bbr_log_type_statechange(bbr, cts, __LINE__);
3121 } else {
3122 /*
3123 * This should not happen really
3124 * unless we remove the startup/drain
3125 * restrictions above.
3126 */
3127 bbr->rc_bbr_state = BBR_STATE_STARTUP;
3128 bbr_set_epoch(bbr, cts, __LINE__);
3129 bbr->r_ctl.rc_bbr_state_time = cts;
3130 bbr->r_ctl.rc_lost_at_startup = bbr->r_ctl.rc_lost;
3131 bbr->r_ctl.rc_bbr_hptsi_gain = bbr->r_ctl.rc_startup_pg;
3132 bbr->r_ctl.rc_bbr_cwnd_gain = bbr->r_ctl.rc_startup_pg;
3133 bbr_set_state_target(bbr, __LINE__);
3134 bbr_log_type_statechange(bbr, cts, __LINE__);
3135 }
3136 /* reason 0 is to stop using lt-bw */
3137 bbr_log_type_ltbw(bbr, cts, 0, 0, 0, 0, 0);
3138 return;
3139 }
3140 if (bbr_lt_intvl_fp == 0) {
3141 /* Not doing false-positive detection */
3142 return;
3143 }
3144 /* False positive detection */
3145 if (diff == bbr_lt_intvl_fp) {
3146 /* At bbr_lt_intvl_fp we record the lost */
3147 bbr->r_ctl.rc_lt_del = bbr->r_ctl.rc_delivered;
3148 bbr->r_ctl.rc_lt_lost = bbr->r_ctl.rc_lost;
3149 } else if (diff > (bbr_lt_intvl_min_rtts + bbr_lt_intvl_fp)) {
3150 /* Now is our loss rate still high? */
3151 lost = bbr->r_ctl.rc_lost - bbr->r_ctl.rc_lt_lost;
3152 delivered = bbr->r_ctl.rc_delivered - bbr->r_ctl.rc_lt_del;
3153 if ((delivered == 0) ||
3154 (((lost * 1000)/delivered) < bbr_lt_fd_thresh)) {
3155 /* No still below our threshold */
3156 bbr_log_type_ltbw(bbr, cts, 7, lost, delivered, 0, 0);
3157 } else {
3158 /* Yikes its still high, it must be a false positive */
3159 bbr_log_type_ltbw(bbr, cts, 8, lost, delivered, 0, 0);
3160 goto reset_all;
3161 }
3162 }
3163 return;
3164 }
3165 /*
3166 * Wait for the first loss before sampling, to let the policer
3167 * exhaust its tokens and estimate the steady-state rate allowed by
3168 * the policer. Starting samples earlier includes bursts that
3169 * over-estimate the bw.
3170 */
3171 if (bbr->rc_lt_is_sampling == 0) {
3172 /* reason 1 is to begin doing the sampling */
3173 if (loss_detected == 0)
3174 return;
3175 bbr_reset_lt_bw_interval(bbr, cts);
3176 bbr->rc_lt_is_sampling = 1;
3177 bbr_log_type_ltbw(bbr, cts, 1, 0, 0, 0, 0);
3178 return;
3179 }
3180 /* Now how long were we delivering long term last> */
3181 if (TSTMP_GEQ(bbr->r_ctl.rc_del_time, bbr->r_ctl.rc_lt_time))
3182 d_time = bbr->r_ctl.rc_del_time - bbr->r_ctl.rc_lt_time;
3183 else
3184 d_time = 0;
3185
3186 /* To avoid underestimates, reset sampling if we run out of data. */
3187 if (bbr->r_ctl.r_app_limited_until) {
3188 /* Can not measure in app-limited state */
3189 bbr_reset_lt_bw_sampling(bbr, cts);
3190 /* reason 2 is to reset sampling due to app limits */
3191 bbr_log_type_ltbw(bbr, cts, 2, 0, 0, 0, d_time);
3192 return;
3193 }
3194 diff = bbr->r_ctl.rc_pkt_epoch - bbr->r_ctl.rc_lt_epoch;
3195 if (diff < bbr_lt_intvl_min_rtts) {
3196 /*
3197 * need more samples (we don't
3198 * start on a round like linux so
3199 * we need 1 more).
3200 */
3201 /* 6 is not_enough time or no-loss */
3202 bbr_log_type_ltbw(bbr, cts, 6, 0, 0, 0, d_time);
3203 return;
3204 }
3205 if (diff > (4 * bbr_lt_intvl_min_rtts)) {
3206 /*
3207 * For now if we wait too long, reset all sampling. We need
3208 * to do some research here, its possible that we should
3209 * base this on how much loss as occurred.. something like
3210 * if its under 10% (or some thresh) reset all otherwise
3211 * don't. Thats for phase II I guess.
3212 */
3213 bbr_reset_lt_bw_sampling(bbr, cts);
3214 /* reason 3 is to reset sampling due too long of sampling */
3215 bbr_log_type_ltbw(bbr, cts, 3, 0, 0, 0, d_time);
3216 return;
3217 }
3218 /*
3219 * End sampling interval when a packet is lost, so we estimate the
3220 * policer tokens were exhausted. Stopping the sampling before the
3221 * tokens are exhausted under-estimates the policed rate.
3222 */
3223 if (loss_detected == 0) {
3224 /* 6 is not_enough time or no-loss */
3225 bbr_log_type_ltbw(bbr, cts, 6, 0, 0, 0, d_time);
3226 return;
3227 }
3228 /* Calculate packets lost and delivered in sampling interval. */
3229 lost = bbr->r_ctl.rc_lost - bbr->r_ctl.rc_lt_lost;
3230 delivered = bbr->r_ctl.rc_delivered - bbr->r_ctl.rc_lt_del;
3231 if ((delivered == 0) ||
3232 (((lost * 1000)/delivered) < bbr_lt_loss_thresh)) {
3233 bbr_log_type_ltbw(bbr, cts, 6, lost, delivered, 0, d_time);
3234 return;
3235 }
3236 if (d_time < 1000) {
3237 /* Not enough time. wait */
3238 /* 6 is not_enough time or no-loss */
3239 bbr_log_type_ltbw(bbr, cts, 6, 0, 0, 0, d_time);
3240 return;
3241 }
3242 if (d_time >= (0xffffffff / USECS_IN_MSEC)) {
3243 /* Too long */
3244 bbr_reset_lt_bw_sampling(bbr, cts);
3245 /* reason 3 is to reset sampling due too long of sampling */
3246 bbr_log_type_ltbw(bbr, cts, 3, 0, 0, 0, d_time);
3247 return;
3248 }
3249 del_time = d_time;
3250 bw = delivered;
3251 bw *= (uint64_t)USECS_IN_SECOND;
3252 bw /= del_time;
3253 bbr_lt_bw_samp_done(bbr, bw, cts, d_time);
3254 }
3255
3256 /*
3257 * Allocate a sendmap from our zone.
3258 */
3259 static struct bbr_sendmap *
bbr_alloc(struct tcp_bbr * bbr)3260 bbr_alloc(struct tcp_bbr *bbr)
3261 {
3262 struct bbr_sendmap *rsm;
3263
3264 BBR_STAT_INC(bbr_to_alloc);
3265 rsm = uma_zalloc(bbr_zone, (M_NOWAIT | M_ZERO));
3266 if (rsm) {
3267 bbr->r_ctl.rc_num_maps_alloced++;
3268 return (rsm);
3269 }
3270 if (bbr->r_ctl.rc_free_cnt) {
3271 BBR_STAT_INC(bbr_to_alloc_emerg);
3272 rsm = TAILQ_FIRST(&bbr->r_ctl.rc_free);
3273 TAILQ_REMOVE(&bbr->r_ctl.rc_free, rsm, r_next);
3274 bbr->r_ctl.rc_free_cnt--;
3275 return (rsm);
3276 }
3277 BBR_STAT_INC(bbr_to_alloc_failed);
3278 return (NULL);
3279 }
3280
3281 static struct bbr_sendmap *
bbr_alloc_full_limit(struct tcp_bbr * bbr)3282 bbr_alloc_full_limit(struct tcp_bbr *bbr)
3283 {
3284 if ((V_tcp_map_entries_limit > 0) &&
3285 (bbr->r_ctl.rc_num_maps_alloced >= V_tcp_map_entries_limit)) {
3286 BBR_STAT_INC(bbr_alloc_limited);
3287 if (!bbr->alloc_limit_reported) {
3288 bbr->alloc_limit_reported = 1;
3289 BBR_STAT_INC(bbr_alloc_limited_conns);
3290 }
3291 return (NULL);
3292 }
3293 return (bbr_alloc(bbr));
3294 }
3295
3296 /* wrapper to allocate a sendmap entry, subject to a specific limit */
3297 static struct bbr_sendmap *
bbr_alloc_limit(struct tcp_bbr * bbr,uint8_t limit_type)3298 bbr_alloc_limit(struct tcp_bbr *bbr, uint8_t limit_type)
3299 {
3300 struct bbr_sendmap *rsm;
3301
3302 if (limit_type) {
3303 /* currently there is only one limit type */
3304 if (V_tcp_map_split_limit > 0 &&
3305 bbr->r_ctl.rc_num_split_allocs >= V_tcp_map_split_limit) {
3306 BBR_STAT_INC(bbr_split_limited);
3307 if (!bbr->alloc_limit_reported) {
3308 bbr->alloc_limit_reported = 1;
3309 BBR_STAT_INC(bbr_alloc_limited_conns);
3310 }
3311 return (NULL);
3312 }
3313 }
3314
3315 /* allocate and mark in the limit type, if set */
3316 rsm = bbr_alloc(bbr);
3317 if (rsm != NULL && limit_type) {
3318 rsm->r_limit_type = limit_type;
3319 bbr->r_ctl.rc_num_split_allocs++;
3320 }
3321 return (rsm);
3322 }
3323
3324 static void
bbr_free(struct tcp_bbr * bbr,struct bbr_sendmap * rsm)3325 bbr_free(struct tcp_bbr *bbr, struct bbr_sendmap *rsm)
3326 {
3327 if (rsm->r_limit_type) {
3328 /* currently there is only one limit type */
3329 bbr->r_ctl.rc_num_split_allocs--;
3330 }
3331 if (rsm->r_is_smallmap)
3332 bbr->r_ctl.rc_num_small_maps_alloced--;
3333 if (bbr->r_ctl.rc_tlp_send == rsm)
3334 bbr->r_ctl.rc_tlp_send = NULL;
3335 if (bbr->r_ctl.rc_resend == rsm) {
3336 bbr->r_ctl.rc_resend = NULL;
3337 }
3338 if (bbr->r_ctl.rc_next == rsm)
3339 bbr->r_ctl.rc_next = NULL;
3340 if (bbr->r_ctl.rc_sacklast == rsm)
3341 bbr->r_ctl.rc_sacklast = NULL;
3342 if (bbr->r_ctl.rc_free_cnt < bbr_min_req_free) {
3343 memset(rsm, 0, sizeof(struct bbr_sendmap));
3344 TAILQ_INSERT_TAIL(&bbr->r_ctl.rc_free, rsm, r_next);
3345 rsm->r_limit_type = 0;
3346 bbr->r_ctl.rc_free_cnt++;
3347 return;
3348 }
3349 bbr->r_ctl.rc_num_maps_alloced--;
3350 uma_zfree(bbr_zone, rsm);
3351 }
3352
3353 /*
3354 * Returns the BDP.
3355 */
3356 static uint64_t
bbr_get_bw_delay_prod(uint64_t rtt,uint64_t bw)3357 bbr_get_bw_delay_prod(uint64_t rtt, uint64_t bw) {
3358 /*
3359 * Calculate the bytes in flight needed given the bw (in bytes per
3360 * second) and the specifyed rtt in useconds. We need to put out the
3361 * returned value per RTT to match that rate. Gain will normally
3362 * raise it up from there.
3363 *
3364 * This should not overflow as long as the bandwidth is below 1
3365 * TByte per second (bw < 10**12 = 2**40) and the rtt is smaller
3366 * than 1000 seconds (rtt < 10**3 * 10**6 = 10**9 = 2**30).
3367 */
3368 uint64_t usec_per_sec;
3369
3370 usec_per_sec = USECS_IN_SECOND;
3371 return ((rtt * bw) / usec_per_sec);
3372 }
3373
3374 /*
3375 * Return the initial cwnd.
3376 */
3377 static uint32_t
bbr_initial_cwnd(struct tcp_bbr * bbr,struct tcpcb * tp)3378 bbr_initial_cwnd(struct tcp_bbr *bbr, struct tcpcb *tp)
3379 {
3380 uint32_t i_cwnd;
3381
3382 if (bbr->rc_init_win) {
3383 i_cwnd = bbr->rc_init_win * tp->t_maxseg;
3384 } else if (V_tcp_initcwnd_segments)
3385 i_cwnd = min((V_tcp_initcwnd_segments * tp->t_maxseg),
3386 max(2 * tp->t_maxseg, 14600));
3387 else if (V_tcp_do_rfc3390)
3388 i_cwnd = min(4 * tp->t_maxseg,
3389 max(2 * tp->t_maxseg, 4380));
3390 else {
3391 /* Per RFC5681 Section 3.1 */
3392 if (tp->t_maxseg > 2190)
3393 i_cwnd = 2 * tp->t_maxseg;
3394 else if (tp->t_maxseg > 1095)
3395 i_cwnd = 3 * tp->t_maxseg;
3396 else
3397 i_cwnd = 4 * tp->t_maxseg;
3398 }
3399 return (i_cwnd);
3400 }
3401
3402 /*
3403 * Given a specified gain, return the target
3404 * cwnd based on that gain.
3405 */
3406 static uint32_t
bbr_get_raw_target_cwnd(struct tcp_bbr * bbr,uint32_t gain,uint64_t bw)3407 bbr_get_raw_target_cwnd(struct tcp_bbr *bbr, uint32_t gain, uint64_t bw)
3408 {
3409 uint64_t bdp, rtt;
3410 uint32_t cwnd;
3411
3412 if ((get_filter_value_small(&bbr->r_ctl.rc_rttprop) == 0xffffffff) ||
3413 (bbr_get_full_bw(bbr) == 0)) {
3414 /* No measurements yet */
3415 return (bbr_initial_cwnd(bbr, bbr->rc_tp));
3416 }
3417 /*
3418 * Get bytes per RTT needed (rttProp is normally in
3419 * bbr_cwndtarget_rtt_touse)
3420 */
3421 rtt = bbr_get_rtt(bbr, bbr_cwndtarget_rtt_touse);
3422 /* Get the bdp from the two values */
3423 bdp = bbr_get_bw_delay_prod(rtt, bw);
3424 /* Now apply the gain */
3425 cwnd = (uint32_t)(((bdp * ((uint64_t)gain)) + (uint64_t)(BBR_UNIT - 1)) / ((uint64_t)BBR_UNIT));
3426
3427 return (cwnd);
3428 }
3429
3430 static uint32_t
bbr_get_target_cwnd(struct tcp_bbr * bbr,uint64_t bw,uint32_t gain)3431 bbr_get_target_cwnd(struct tcp_bbr *bbr, uint64_t bw, uint32_t gain)
3432 {
3433 uint32_t cwnd, mss;
3434
3435 mss = min((bbr->rc_tp->t_maxseg - bbr->rc_last_options), bbr->r_ctl.rc_pace_max_segs);
3436 /* Get the base cwnd with gain rounded to a mss */
3437 cwnd = roundup(bbr_get_raw_target_cwnd(bbr, bw, gain), mss);
3438 /*
3439 * Add in N (2 default since we do not have a
3440 * fq layer to trap packets in) quanta's per the I-D
3441 * section 4.2.3.2 quanta adjust.
3442 */
3443 cwnd += (bbr_quanta * bbr->r_ctl.rc_pace_max_segs);
3444 if (bbr->rc_use_google) {
3445 if((bbr->rc_bbr_state == BBR_STATE_PROBE_BW) &&
3446 (bbr_state_val(bbr) == BBR_SUB_GAIN)) {
3447 /*
3448 * The linux implementation adds
3449 * an extra 2 x mss in gain cycle which
3450 * is documented no-where except in the code.
3451 * so we add more for Neal undocumented feature
3452 */
3453 cwnd += 2 * mss;
3454 }
3455 if ((cwnd / mss) & 0x1) {
3456 /* Round up for odd num mss */
3457 cwnd += mss;
3458 }
3459 }
3460 /* Are we below the min cwnd? */
3461 if (cwnd < get_min_cwnd(bbr))
3462 return (get_min_cwnd(bbr));
3463 return (cwnd);
3464 }
3465
3466 static uint16_t
bbr_gain_adjust(struct tcp_bbr * bbr,uint16_t gain)3467 bbr_gain_adjust(struct tcp_bbr *bbr, uint16_t gain)
3468 {
3469 if (gain < 1)
3470 gain = 1;
3471 return (gain);
3472 }
3473
3474 static uint32_t
bbr_get_header_oh(struct tcp_bbr * bbr)3475 bbr_get_header_oh(struct tcp_bbr *bbr)
3476 {
3477 int seg_oh;
3478
3479 seg_oh = 0;
3480 if (bbr->r_ctl.rc_inc_tcp_oh) {
3481 /* Do we include TCP overhead? */
3482 seg_oh = (bbr->rc_last_options + sizeof(struct tcphdr));
3483 }
3484 if (bbr->r_ctl.rc_inc_ip_oh) {
3485 /* Do we include IP overhead? */
3486 #ifdef INET6
3487 if (bbr->r_is_v6) {
3488 seg_oh += sizeof(struct ip6_hdr);
3489 } else
3490 #endif
3491 {
3492
3493 #ifdef INET
3494 seg_oh += sizeof(struct ip);
3495 #endif
3496 }
3497 }
3498 if (bbr->r_ctl.rc_inc_enet_oh) {
3499 /* Do we include the ethernet overhead? */
3500 seg_oh += sizeof(struct ether_header);
3501 }
3502 return(seg_oh);
3503 }
3504
3505 static uint32_t
bbr_get_pacing_length(struct tcp_bbr * bbr,uint16_t gain,uint32_t useconds_time,uint64_t bw)3506 bbr_get_pacing_length(struct tcp_bbr *bbr, uint16_t gain, uint32_t useconds_time, uint64_t bw)
3507 {
3508 uint64_t divor, res, tim;
3509
3510 if (useconds_time == 0)
3511 return (0);
3512 gain = bbr_gain_adjust(bbr, gain);
3513 divor = (uint64_t)USECS_IN_SECOND * (uint64_t)BBR_UNIT;
3514 tim = useconds_time;
3515 res = (tim * bw * gain) / divor;
3516 if (res == 0)
3517 res = 1;
3518 return ((uint32_t)res);
3519 }
3520
3521 /*
3522 * Given a gain and a length return the delay in useconds that
3523 * should be used to evenly space out packets
3524 * on the connection (based on the gain factor).
3525 */
3526 static uint32_t
bbr_get_pacing_delay(struct tcp_bbr * bbr,uint16_t gain,int32_t len,uint32_t cts,int nolog)3527 bbr_get_pacing_delay(struct tcp_bbr *bbr, uint16_t gain, int32_t len, uint32_t cts, int nolog)
3528 {
3529 uint64_t bw, lentim, res;
3530 uint32_t usecs, srtt, over = 0;
3531 uint32_t seg_oh, num_segs, maxseg;
3532
3533 if (len == 0)
3534 return (0);
3535
3536 maxseg = bbr->rc_tp->t_maxseg - bbr->rc_last_options;
3537 num_segs = (len + maxseg - 1) / maxseg;
3538 if (bbr->rc_use_google == 0) {
3539 seg_oh = bbr_get_header_oh(bbr);
3540 len += (num_segs * seg_oh);
3541 }
3542 gain = bbr_gain_adjust(bbr, gain);
3543 bw = bbr_get_bw(bbr);
3544 if (bbr->rc_use_google) {
3545 uint64_t cbw;
3546
3547 /*
3548 * Reduce the b/w by the google discount
3549 * factor 10 = 1%.
3550 */
3551 cbw = bw * (uint64_t)(1000 - bbr->r_ctl.bbr_google_discount);
3552 cbw /= (uint64_t)1000;
3553 /* We don't apply a discount if it results in 0 */
3554 if (cbw > 0)
3555 bw = cbw;
3556 }
3557 lentim = ((uint64_t)len *
3558 (uint64_t)USECS_IN_SECOND *
3559 (uint64_t)BBR_UNIT);
3560 res = lentim / ((uint64_t)gain * bw);
3561 if (res == 0)
3562 res = 1;
3563 usecs = (uint32_t)res;
3564 srtt = bbr_get_rtt(bbr, BBR_SRTT);
3565 if (bbr_hptsi_max_mul && bbr_hptsi_max_div &&
3566 (bbr->rc_use_google == 0) &&
3567 (usecs > ((srtt * bbr_hptsi_max_mul) / bbr_hptsi_max_div))) {
3568 /*
3569 * We cannot let the delay be more than 1/2 the srtt time.
3570 * Otherwise we cannot pace out or send properly.
3571 */
3572 over = usecs = (srtt * bbr_hptsi_max_mul) / bbr_hptsi_max_div;
3573 BBR_STAT_INC(bbr_hpts_min_time);
3574 }
3575 if (!nolog)
3576 bbr_log_pacing_delay_calc(bbr, gain, len, cts, usecs, bw, over, 1);
3577 return (usecs);
3578 }
3579
3580 static void
bbr_ack_received(struct tcpcb * tp,struct tcp_bbr * bbr,struct tcphdr * th,uint32_t bytes_this_ack,uint32_t sack_changed,uint32_t prev_acked,int32_t line,uint32_t losses)3581 bbr_ack_received(struct tcpcb *tp, struct tcp_bbr *bbr, struct tcphdr *th, uint32_t bytes_this_ack,
3582 uint32_t sack_changed, uint32_t prev_acked, int32_t line, uint32_t losses)
3583 {
3584 uint64_t bw;
3585 uint32_t cwnd, target_cwnd, saved_bytes, maxseg;
3586 int32_t meth;
3587
3588 INP_WLOCK_ASSERT(tptoinpcb(tp));
3589
3590 #ifdef STATS
3591 if ((tp->t_flags & TF_GPUTINPROG) &&
3592 SEQ_GEQ(th->th_ack, tp->gput_ack)) {
3593 /*
3594 * Strech acks and compressed acks will cause this to
3595 * oscillate but we are doing it the same way as the main
3596 * stack so it will be compariable (though possibly not
3597 * ideal).
3598 */
3599 int32_t cgput;
3600 int64_t gput, time_stamp;
3601
3602 gput = (int64_t) (th->th_ack - tp->gput_seq) * 8;
3603 time_stamp = max(1, ((bbr->r_ctl.rc_rcvtime - tp->gput_ts) / 1000));
3604 cgput = gput / time_stamp;
3605 stats_voi_update_abs_u32(tp->t_stats, VOI_TCP_GPUT,
3606 cgput);
3607 if (tp->t_stats_gput_prev > 0)
3608 stats_voi_update_abs_s32(tp->t_stats,
3609 VOI_TCP_GPUT_ND,
3610 ((gput - tp->t_stats_gput_prev) * 100) /
3611 tp->t_stats_gput_prev);
3612 tp->t_flags &= ~TF_GPUTINPROG;
3613 tp->t_stats_gput_prev = cgput;
3614 }
3615 #endif
3616 if ((bbr->rc_bbr_state == BBR_STATE_PROBE_RTT) &&
3617 ((bbr->r_ctl.bbr_rttprobe_gain_val == 0) || bbr->rc_use_google)) {
3618 /* We don't change anything in probe-rtt */
3619 return;
3620 }
3621 maxseg = tp->t_maxseg - bbr->rc_last_options;
3622 saved_bytes = bytes_this_ack;
3623 bytes_this_ack += sack_changed;
3624 if (bytes_this_ack > prev_acked) {
3625 bytes_this_ack -= prev_acked;
3626 /*
3627 * A byte ack'd gives us a full mss
3628 * to be like linux i.e. they count packets.
3629 */
3630 if ((bytes_this_ack < maxseg) && bbr->rc_use_google)
3631 bytes_this_ack = maxseg;
3632 } else {
3633 /* Unlikely */
3634 bytes_this_ack = 0;
3635 }
3636 cwnd = tp->snd_cwnd;
3637 bw = get_filter_value(&bbr->r_ctl.rc_delrate);
3638 if (bw)
3639 target_cwnd = bbr_get_target_cwnd(bbr,
3640 bw,
3641 (uint32_t)bbr->r_ctl.rc_bbr_cwnd_gain);
3642 else
3643 target_cwnd = bbr_initial_cwnd(bbr, bbr->rc_tp);
3644 if (IN_RECOVERY(tp->t_flags) &&
3645 (bbr->bbr_prev_in_rec == 0)) {
3646 /*
3647 * We are entering recovery and
3648 * thus packet conservation.
3649 */
3650 bbr->pkt_conservation = 1;
3651 bbr->r_ctl.rc_recovery_start = bbr->r_ctl.rc_rcvtime;
3652 cwnd = ctf_flight_size(tp,
3653 (bbr->r_ctl.rc_sacked + bbr->r_ctl.rc_lost_bytes)) +
3654 bytes_this_ack;
3655 }
3656 if (IN_RECOVERY(tp->t_flags)) {
3657 uint32_t flight;
3658
3659 bbr->bbr_prev_in_rec = 1;
3660 if (cwnd > losses) {
3661 cwnd -= losses;
3662 if (cwnd < maxseg)
3663 cwnd = maxseg;
3664 } else
3665 cwnd = maxseg;
3666 flight = ctf_flight_size(tp,
3667 (bbr->r_ctl.rc_sacked + bbr->r_ctl.rc_lost_bytes));
3668 bbr_log_type_cwndupd(bbr, flight, 0,
3669 losses, 10, 0, 0, line);
3670 if (bbr->pkt_conservation) {
3671 uint32_t time_in;
3672
3673 if (TSTMP_GEQ(bbr->r_ctl.rc_rcvtime, bbr->r_ctl.rc_recovery_start))
3674 time_in = bbr->r_ctl.rc_rcvtime - bbr->r_ctl.rc_recovery_start;
3675 else
3676 time_in = 0;
3677
3678 if (time_in >= bbr_get_rtt(bbr, BBR_RTT_PROP)) {
3679 /* Clear packet conservation after an rttProp */
3680 bbr->pkt_conservation = 0;
3681 } else {
3682 if ((flight + bytes_this_ack) > cwnd)
3683 cwnd = flight + bytes_this_ack;
3684 if (cwnd < get_min_cwnd(bbr))
3685 cwnd = get_min_cwnd(bbr);
3686 tp->snd_cwnd = cwnd;
3687 bbr_log_type_cwndupd(bbr, saved_bytes, sack_changed,
3688 prev_acked, 1, target_cwnd, th->th_ack, line);
3689 return;
3690 }
3691 }
3692 } else
3693 bbr->bbr_prev_in_rec = 0;
3694 if ((bbr->rc_use_google == 0) && bbr->r_ctl.restrict_growth) {
3695 bbr->r_ctl.restrict_growth--;
3696 if (bytes_this_ack > maxseg)
3697 bytes_this_ack = maxseg;
3698 }
3699 if (bbr->rc_filled_pipe) {
3700 /*
3701 * Here we have exited startup and filled the pipe. We will
3702 * thus allow the cwnd to shrink to the target. We hit here
3703 * mostly.
3704 */
3705 uint32_t s_cwnd;
3706
3707 meth = 2;
3708 s_cwnd = min((cwnd + bytes_this_ack), target_cwnd);
3709 if (s_cwnd > cwnd)
3710 cwnd = s_cwnd;
3711 else if (bbr_cwnd_may_shrink || bbr->rc_use_google || bbr->rc_no_pacing)
3712 cwnd = s_cwnd;
3713 } else {
3714 /*
3715 * Here we are still in startup, we increase cwnd by what
3716 * has been acked.
3717 */
3718 if ((cwnd < target_cwnd) ||
3719 (bbr->rc_past_init_win == 0)) {
3720 meth = 3;
3721 cwnd += bytes_this_ack;
3722 } else {
3723 /*
3724 * Method 4 means we are at target so no gain in
3725 * startup and past the initial window.
3726 */
3727 meth = 4;
3728 }
3729 }
3730 tp->snd_cwnd = max(cwnd, get_min_cwnd(bbr));
3731 bbr_log_type_cwndupd(bbr, saved_bytes, sack_changed, prev_acked, meth, target_cwnd, th->th_ack, line);
3732 }
3733
3734 static void
tcp_bbr_partialack(struct tcpcb * tp)3735 tcp_bbr_partialack(struct tcpcb *tp)
3736 {
3737 struct tcp_bbr *bbr;
3738
3739 bbr = (struct tcp_bbr *)tp->t_fb_ptr;
3740 INP_WLOCK_ASSERT(tptoinpcb(tp));
3741 if (ctf_flight_size(tp,
3742 (bbr->r_ctl.rc_sacked + bbr->r_ctl.rc_lost_bytes)) <=
3743 tp->snd_cwnd) {
3744 bbr->r_wanted_output = 1;
3745 }
3746 }
3747
3748 static void
bbr_post_recovery(struct tcpcb * tp)3749 bbr_post_recovery(struct tcpcb *tp)
3750 {
3751 struct tcp_bbr *bbr;
3752 uint32_t flight;
3753
3754 INP_WLOCK_ASSERT(tptoinpcb(tp));
3755 bbr = (struct tcp_bbr *)tp->t_fb_ptr;
3756 /*
3757 * Here we just exit recovery.
3758 */
3759 EXIT_RECOVERY(tp->t_flags);
3760 /* Lock in our b/w reduction for the specified number of pkt-epochs */
3761 bbr->r_recovery_bw = 0;
3762 tp->snd_recover = tp->snd_una;
3763 tcp_bbr_tso_size_check(bbr, bbr->r_ctl.rc_rcvtime);
3764 bbr->pkt_conservation = 0;
3765 if (bbr->rc_use_google == 0) {
3766 /*
3767 * For non-google mode lets
3768 * go ahead and make sure we clear
3769 * the recovery state so if we
3770 * bounce back in to recovery we
3771 * will do PC.
3772 */
3773 bbr->bbr_prev_in_rec = 0;
3774 }
3775 bbr_log_type_exit_rec(bbr);
3776 if (bbr->rc_bbr_state != BBR_STATE_PROBE_RTT) {
3777 tp->snd_cwnd = max(tp->snd_cwnd, bbr->r_ctl.rc_cwnd_on_ent);
3778 bbr_log_type_cwndupd(bbr, 0, 0, 0, 15, 0, 0, __LINE__);
3779 } else {
3780 /* For probe-rtt case lets fix up its saved_cwnd */
3781 if (bbr->r_ctl.rc_saved_cwnd < bbr->r_ctl.rc_cwnd_on_ent) {
3782 bbr->r_ctl.rc_saved_cwnd = bbr->r_ctl.rc_cwnd_on_ent;
3783 bbr_log_type_cwndupd(bbr, 0, 0, 0, 16, 0, 0, __LINE__);
3784 }
3785 }
3786 flight = ctf_flight_size(tp,
3787 (bbr->r_ctl.rc_sacked + bbr->r_ctl.rc_lost_bytes));
3788 if ((bbr->rc_use_google == 0) &&
3789 bbr_do_red) {
3790 uint64_t val, lr2use;
3791 uint32_t maxseg, newcwnd, acks_inflight, ratio, cwnd;
3792 uint32_t *cwnd_p;
3793
3794 if (bbr_get_rtt(bbr, BBR_SRTT)) {
3795 val = ((uint64_t)bbr_get_rtt(bbr, BBR_RTT_PROP) * (uint64_t)1000);
3796 val /= bbr_get_rtt(bbr, BBR_SRTT);
3797 ratio = (uint32_t)val;
3798 } else
3799 ratio = 1000;
3800
3801 bbr_log_type_cwndupd(bbr, bbr_red_mul, bbr_red_div,
3802 bbr->r_ctl.recovery_lr, 21,
3803 ratio,
3804 bbr->r_ctl.rc_red_cwnd_pe,
3805 __LINE__);
3806 if ((ratio < bbr_do_red) || (bbr_do_red == 0))
3807 goto done;
3808 if (((bbr->rc_bbr_state == BBR_STATE_PROBE_RTT) &&
3809 bbr_prtt_slam_cwnd) ||
3810 (bbr_sub_drain_slam_cwnd &&
3811 (bbr->rc_bbr_state == BBR_STATE_PROBE_BW) &&
3812 bbr->rc_hit_state_1 &&
3813 (bbr_state_val(bbr) == BBR_SUB_DRAIN)) ||
3814 ((bbr->rc_bbr_state == BBR_STATE_DRAIN) &&
3815 bbr_slam_cwnd_in_main_drain)) {
3816 /*
3817 * Here we must poke at the saved cwnd
3818 * as well as the cwnd.
3819 */
3820 cwnd = bbr->r_ctl.rc_saved_cwnd;
3821 cwnd_p = &bbr->r_ctl.rc_saved_cwnd;
3822 } else {
3823 cwnd = tp->snd_cwnd;
3824 cwnd_p = &tp->snd_cwnd;
3825 }
3826 maxseg = tp->t_maxseg - bbr->rc_last_options;
3827 /* Add the overall lr with the recovery lr */
3828 if (bbr->r_ctl.rc_lost == 0)
3829 lr2use = 0;
3830 else if (bbr->r_ctl.rc_delivered == 0)
3831 lr2use = 1000;
3832 else {
3833 lr2use = (uint64_t)bbr->r_ctl.rc_lost * (uint64_t)1000;
3834 lr2use /= bbr->r_ctl.rc_delivered;
3835 }
3836 lr2use += bbr->r_ctl.recovery_lr;
3837 acks_inflight = (flight / (maxseg * 2));
3838 if (bbr_red_scale) {
3839 lr2use *= bbr_get_rtt(bbr, BBR_SRTT);
3840 lr2use /= bbr_red_scale;
3841 if ((bbr_red_growth_restrict) &&
3842 ((bbr_get_rtt(bbr, BBR_SRTT)/bbr_red_scale) > 1))
3843 bbr->r_ctl.restrict_growth += acks_inflight;
3844 }
3845 if (lr2use) {
3846 val = (uint64_t)cwnd * lr2use;
3847 val /= 1000;
3848 if (cwnd > val)
3849 newcwnd = roundup((cwnd - val), maxseg);
3850 else
3851 newcwnd = maxseg;
3852 } else {
3853 val = (uint64_t)cwnd * (uint64_t)bbr_red_mul;
3854 val /= (uint64_t)bbr_red_div;
3855 newcwnd = roundup((uint32_t)val, maxseg);
3856 }
3857 /* with standard delayed acks how many acks can I expect? */
3858 if (bbr_drop_limit == 0) {
3859 /*
3860 * Anticpate how much we will
3861 * raise the cwnd based on the acks.
3862 */
3863 if ((newcwnd + (acks_inflight * maxseg)) < get_min_cwnd(bbr)) {
3864 /* We do enforce the min (with the acks) */
3865 newcwnd = (get_min_cwnd(bbr) - acks_inflight);
3866 }
3867 } else {
3868 /*
3869 * A strict drop limit of N is inplace
3870 */
3871 if (newcwnd < (bbr_drop_limit * maxseg)) {
3872 newcwnd = bbr_drop_limit * maxseg;
3873 }
3874 }
3875 /* For the next N acks do we restrict the growth */
3876 *cwnd_p = newcwnd;
3877 if (tp->snd_cwnd > newcwnd)
3878 tp->snd_cwnd = newcwnd;
3879 bbr_log_type_cwndupd(bbr, bbr_red_mul, bbr_red_div, val, 22,
3880 (uint32_t)lr2use,
3881 bbr_get_rtt(bbr, BBR_SRTT), __LINE__);
3882 bbr->r_ctl.rc_red_cwnd_pe = bbr->r_ctl.rc_pkt_epoch;
3883 }
3884 done:
3885 bbr->r_ctl.recovery_lr = 0;
3886 if (flight <= tp->snd_cwnd) {
3887 bbr->r_wanted_output = 1;
3888 }
3889 tcp_bbr_tso_size_check(bbr, bbr->r_ctl.rc_rcvtime);
3890 }
3891
3892 static void
bbr_setup_red_bw(struct tcp_bbr * bbr,uint32_t cts)3893 bbr_setup_red_bw(struct tcp_bbr *bbr, uint32_t cts)
3894 {
3895 bbr->r_ctl.red_bw = get_filter_value(&bbr->r_ctl.rc_delrate);
3896 /* Limit the drop in b/w to 1/2 our current filter. */
3897 if (bbr->r_ctl.red_bw > bbr->r_ctl.rc_bbr_cur_del_rate)
3898 bbr->r_ctl.red_bw = bbr->r_ctl.rc_bbr_cur_del_rate;
3899 if (bbr->r_ctl.red_bw < (get_filter_value(&bbr->r_ctl.rc_delrate) / 2))
3900 bbr->r_ctl.red_bw = get_filter_value(&bbr->r_ctl.rc_delrate) / 2;
3901 tcp_bbr_tso_size_check(bbr, cts);
3902 }
3903
3904 static void
bbr_cong_signal(struct tcpcb * tp,struct tcphdr * th,uint32_t type,struct bbr_sendmap * rsm)3905 bbr_cong_signal(struct tcpcb *tp, struct tcphdr *th, uint32_t type, struct bbr_sendmap *rsm)
3906 {
3907 struct tcp_bbr *bbr;
3908
3909 INP_WLOCK_ASSERT(tptoinpcb(tp));
3910 #ifdef STATS
3911 stats_voi_update_abs_u32(tp->t_stats, VOI_TCP_CSIG, type);
3912 #endif
3913 bbr = (struct tcp_bbr *)tp->t_fb_ptr;
3914 switch (type) {
3915 case CC_NDUPACK:
3916 if (!IN_RECOVERY(tp->t_flags)) {
3917 tp->snd_recover = tp->snd_max;
3918 /* Start a new epoch */
3919 bbr_set_pktepoch(bbr, bbr->r_ctl.rc_rcvtime, __LINE__);
3920 if (bbr->rc_lt_is_sampling || bbr->rc_lt_use_bw) {
3921 /*
3922 * Move forward the lt epoch
3923 * so it won't count the truncated
3924 * epoch.
3925 */
3926 bbr->r_ctl.rc_lt_epoch++;
3927 }
3928 if (bbr->rc_bbr_state == BBR_STATE_STARTUP) {
3929 /*
3930 * Just like the policer detection code
3931 * if we are in startup we must push
3932 * forward the last startup epoch
3933 * to hide the truncated PE.
3934 */
3935 bbr->r_ctl.rc_bbr_last_startup_epoch++;
3936 }
3937 bbr->r_ctl.rc_cwnd_on_ent = tp->snd_cwnd;
3938 ENTER_RECOVERY(tp->t_flags);
3939 bbr->rc_tlp_rtx_out = 0;
3940 bbr->r_ctl.recovery_lr = bbr->r_ctl.rc_pkt_epoch_loss_rate;
3941 tcp_bbr_tso_size_check(bbr, bbr->r_ctl.rc_rcvtime);
3942 if (tcp_in_hpts(bbr->rc_tp) &&
3943 ((bbr->r_ctl.rc_hpts_flags & PACE_TMR_RACK) == 0)) {
3944 /*
3945 * When we enter recovery, we need to restart
3946 * any timers. This may mean we gain an agg
3947 * early, which will be made up for at the last
3948 * rxt out.
3949 */
3950 bbr->rc_timer_first = 1;
3951 bbr_timer_cancel(bbr, __LINE__, bbr->r_ctl.rc_rcvtime);
3952 }
3953 /*
3954 * Calculate a new cwnd based on to the current
3955 * delivery rate with no gain. We get the bdp
3956 * without gaining it up like we normally would and
3957 * we use the last cur_del_rate.
3958 */
3959 if ((bbr->rc_use_google == 0) &&
3960 (bbr->r_ctl.bbr_rttprobe_gain_val ||
3961 (bbr->rc_bbr_state != BBR_STATE_PROBE_RTT))) {
3962 tp->snd_cwnd = ctf_flight_size(tp,
3963 (bbr->r_ctl.rc_sacked + bbr->r_ctl.rc_lost_bytes)) +
3964 (tp->t_maxseg - bbr->rc_last_options);
3965 if (tp->snd_cwnd < get_min_cwnd(bbr)) {
3966 /* We always gate to min cwnd */
3967 tp->snd_cwnd = get_min_cwnd(bbr);
3968 }
3969 bbr_log_type_cwndupd(bbr, 0, 0, 0, 14, 0, 0, __LINE__);
3970 }
3971 bbr_log_type_enter_rec(bbr, rsm->r_start);
3972 }
3973 break;
3974 case CC_RTO_ERR:
3975 KMOD_TCPSTAT_INC(tcps_sndrexmitbad);
3976 /* RTO was unnecessary, so reset everything. */
3977 bbr_reset_lt_bw_sampling(bbr, bbr->r_ctl.rc_rcvtime);
3978 if (bbr->rc_bbr_state != BBR_STATE_PROBE_RTT) {
3979 tp->snd_cwnd = tp->snd_cwnd_prev;
3980 tp->snd_ssthresh = tp->snd_ssthresh_prev;
3981 tp->snd_recover = tp->snd_recover_prev;
3982 tp->snd_cwnd = max(tp->snd_cwnd, bbr->r_ctl.rc_cwnd_on_ent);
3983 bbr_log_type_cwndupd(bbr, 0, 0, 0, 13, 0, 0, __LINE__);
3984 }
3985 tp->t_badrxtwin = 0;
3986 break;
3987 }
3988 }
3989
3990 /*
3991 * Indicate whether this ack should be delayed. We can delay the ack if
3992 * following conditions are met:
3993 * - There is no delayed ack timer in progress.
3994 * - Our last ack wasn't a 0-sized window. We never want to delay
3995 * the ack that opens up a 0-sized window.
3996 * - LRO wasn't used for this segment. We make sure by checking that the
3997 * segment size is not larger than the MSS.
3998 * - Delayed acks are enabled or this is a half-synchronized T/TCP
3999 * connection.
4000 * - The data being acked is less than a full segment (a stretch ack
4001 * of more than a segment we should ack.
4002 * - nsegs is 1 (if its more than that we received more than 1 ack).
4003 */
4004 #define DELAY_ACK(tp, bbr, nsegs) \
4005 (((tp->t_flags & TF_RXWIN0SENT) == 0) && \
4006 ((tp->t_flags & TF_DELACK) == 0) && \
4007 ((bbr->bbr_segs_rcvd + nsegs) < tp->t_delayed_ack) && \
4008 (tp->t_delayed_ack || (tp->t_flags & TF_NEEDSYN)))
4009
4010 /*
4011 * Return the lowest RSM in the map of
4012 * packets still in flight that is not acked.
4013 * This should normally find on the first one
4014 * since we remove packets from the send
4015 * map after they are marked ACKED.
4016 */
4017 static struct bbr_sendmap *
bbr_find_lowest_rsm(struct tcp_bbr * bbr)4018 bbr_find_lowest_rsm(struct tcp_bbr *bbr)
4019 {
4020 struct bbr_sendmap *rsm;
4021
4022 /*
4023 * Walk the time-order transmitted list looking for an rsm that is
4024 * not acked. This will be the one that was sent the longest time
4025 * ago that is still outstanding.
4026 */
4027 TAILQ_FOREACH(rsm, &bbr->r_ctl.rc_tmap, r_tnext) {
4028 if (rsm->r_flags & BBR_ACKED) {
4029 continue;
4030 }
4031 goto finish;
4032 }
4033 finish:
4034 return (rsm);
4035 }
4036
4037 static struct bbr_sendmap *
bbr_find_high_nonack(struct tcp_bbr * bbr,struct bbr_sendmap * rsm)4038 bbr_find_high_nonack(struct tcp_bbr *bbr, struct bbr_sendmap *rsm)
4039 {
4040 struct bbr_sendmap *prsm;
4041
4042 /*
4043 * Walk the sequence order list backward until we hit and arrive at
4044 * the highest seq not acked. In theory when this is called it
4045 * should be the last segment (which it was not).
4046 */
4047 prsm = rsm;
4048 TAILQ_FOREACH_REVERSE_FROM(prsm, &bbr->r_ctl.rc_map, bbr_head, r_next) {
4049 if (prsm->r_flags & (BBR_ACKED | BBR_HAS_FIN)) {
4050 continue;
4051 }
4052 return (prsm);
4053 }
4054 return (NULL);
4055 }
4056
4057 /*
4058 * Returns to the caller the number of microseconds that
4059 * the packet can be outstanding before we think we
4060 * should have had an ack returned.
4061 */
4062 static uint32_t
bbr_calc_thresh_rack(struct tcp_bbr * bbr,uint32_t srtt,uint32_t cts,struct bbr_sendmap * rsm)4063 bbr_calc_thresh_rack(struct tcp_bbr *bbr, uint32_t srtt, uint32_t cts, struct bbr_sendmap *rsm)
4064 {
4065 /*
4066 * lro is the flag we use to determine if we have seen reordering.
4067 * If it gets set we have seen reordering. The reorder logic either
4068 * works in one of two ways:
4069 *
4070 * If reorder-fade is configured, then we track the last time we saw
4071 * re-ordering occur. If we reach the point where enough time as
4072 * passed we no longer consider reordering has occuring.
4073 *
4074 * Or if reorder-face is 0, then once we see reordering we consider
4075 * the connection to alway be subject to reordering and just set lro
4076 * to 1.
4077 *
4078 * In the end if lro is non-zero we add the extra time for
4079 * reordering in.
4080 */
4081 int32_t lro;
4082 uint32_t thresh, t_rxtcur;
4083
4084 if (srtt == 0)
4085 srtt = 1;
4086 if (bbr->r_ctl.rc_reorder_ts) {
4087 if (bbr->r_ctl.rc_reorder_fade) {
4088 if (SEQ_GEQ(cts, bbr->r_ctl.rc_reorder_ts)) {
4089 lro = cts - bbr->r_ctl.rc_reorder_ts;
4090 if (lro == 0) {
4091 /*
4092 * No time as passed since the last
4093 * reorder, mark it as reordering.
4094 */
4095 lro = 1;
4096 }
4097 } else {
4098 /* Negative time? */
4099 lro = 0;
4100 }
4101 if (lro > bbr->r_ctl.rc_reorder_fade) {
4102 /* Turn off reordering seen too */
4103 bbr->r_ctl.rc_reorder_ts = 0;
4104 lro = 0;
4105 }
4106 } else {
4107 /* Reodering does not fade */
4108 lro = 1;
4109 }
4110 } else {
4111 lro = 0;
4112 }
4113 thresh = srtt + bbr->r_ctl.rc_pkt_delay;
4114 if (lro) {
4115 /* It must be set, if not you get 1/4 rtt */
4116 if (bbr->r_ctl.rc_reorder_shift)
4117 thresh += (srtt >> bbr->r_ctl.rc_reorder_shift);
4118 else
4119 thresh += (srtt >> 2);
4120 } else {
4121 thresh += 1000;
4122 }
4123 /* We don't let the rack timeout be above a RTO */
4124 if ((bbr->rc_tp)->t_srtt == 0)
4125 t_rxtcur = BBR_INITIAL_RTO;
4126 else
4127 t_rxtcur = TICKS_2_USEC(bbr->rc_tp->t_rxtcur);
4128 if (thresh > t_rxtcur) {
4129 thresh = t_rxtcur;
4130 }
4131 /* And we don't want it above the RTO max either */
4132 if (thresh > (((uint32_t)bbr->rc_max_rto_sec) * USECS_IN_SECOND)) {
4133 thresh = (((uint32_t)bbr->rc_max_rto_sec) * USECS_IN_SECOND);
4134 }
4135 bbr_log_thresh_choice(bbr, cts, thresh, lro, srtt, rsm, BBR_TO_FRM_RACK);
4136 return (thresh);
4137 }
4138
4139 /*
4140 * Return to the caller the amount of time in mico-seconds
4141 * that should be used for the TLP timer from the last
4142 * send time of this packet.
4143 */
4144 static uint32_t
bbr_calc_thresh_tlp(struct tcpcb * tp,struct tcp_bbr * bbr,struct bbr_sendmap * rsm,uint32_t srtt,uint32_t cts)4145 bbr_calc_thresh_tlp(struct tcpcb *tp, struct tcp_bbr *bbr,
4146 struct bbr_sendmap *rsm, uint32_t srtt,
4147 uint32_t cts)
4148 {
4149 uint32_t thresh, len, maxseg, t_rxtcur;
4150 struct bbr_sendmap *prsm;
4151
4152 if (srtt == 0)
4153 srtt = 1;
4154 if (bbr->rc_tlp_threshold)
4155 thresh = srtt + (srtt / bbr->rc_tlp_threshold);
4156 else
4157 thresh = (srtt * 2);
4158 maxseg = tp->t_maxseg - bbr->rc_last_options;
4159 /* Get the previous sent packet, if any */
4160 len = rsm->r_end - rsm->r_start;
4161
4162 /* 2.1 behavior */
4163 prsm = TAILQ_PREV(rsm, bbr_head, r_tnext);
4164 if (prsm && (len <= maxseg)) {
4165 /*
4166 * Two packets outstanding, thresh should be (2*srtt) +
4167 * possible inter-packet delay (if any).
4168 */
4169 uint32_t inter_gap = 0;
4170 int idx, nidx;
4171
4172 idx = rsm->r_rtr_cnt - 1;
4173 nidx = prsm->r_rtr_cnt - 1;
4174 if (TSTMP_GEQ(rsm->r_tim_lastsent[nidx], prsm->r_tim_lastsent[idx])) {
4175 /* Yes it was sent later (or at the same time) */
4176 inter_gap = rsm->r_tim_lastsent[idx] - prsm->r_tim_lastsent[nidx];
4177 }
4178 thresh += inter_gap;
4179 } else if (len <= maxseg) {
4180 /*
4181 * Possibly compensate for delayed-ack.
4182 */
4183 uint32_t alt_thresh;
4184
4185 alt_thresh = srtt + (srtt / 2) + bbr_delayed_ack_time;
4186 if (alt_thresh > thresh)
4187 thresh = alt_thresh;
4188 }
4189 /* Not above the current RTO */
4190 if (tp->t_srtt == 0)
4191 t_rxtcur = BBR_INITIAL_RTO;
4192 else
4193 t_rxtcur = TICKS_2_USEC(tp->t_rxtcur);
4194
4195 bbr_log_thresh_choice(bbr, cts, thresh, t_rxtcur, srtt, rsm, BBR_TO_FRM_TLP);
4196 /* Not above an RTO */
4197 if (thresh > t_rxtcur) {
4198 thresh = t_rxtcur;
4199 }
4200 /* Not above a RTO max */
4201 if (thresh > (((uint32_t)bbr->rc_max_rto_sec) * USECS_IN_SECOND)) {
4202 thresh = (((uint32_t)bbr->rc_max_rto_sec) * USECS_IN_SECOND);
4203 }
4204 /* And now apply the user TLP min */
4205 if (thresh < bbr_tlp_min) {
4206 thresh = bbr_tlp_min;
4207 }
4208 return (thresh);
4209 }
4210
4211 /*
4212 * Return one of three RTTs to use (in microseconds).
4213 */
4214 static __inline uint32_t
bbr_get_rtt(struct tcp_bbr * bbr,int32_t rtt_type)4215 bbr_get_rtt(struct tcp_bbr *bbr, int32_t rtt_type)
4216 {
4217 uint32_t f_rtt;
4218 uint32_t srtt;
4219
4220 f_rtt = get_filter_value_small(&bbr->r_ctl.rc_rttprop);
4221 if (get_filter_value_small(&bbr->r_ctl.rc_rttprop) == 0xffffffff) {
4222 /* We have no rtt at all */
4223 if (bbr->rc_tp->t_srtt == 0)
4224 f_rtt = BBR_INITIAL_RTO;
4225 else
4226 f_rtt = (TICKS_2_USEC(bbr->rc_tp->t_srtt) >> TCP_RTT_SHIFT);
4227 /*
4228 * Since we don't know how good the rtt is apply a
4229 * delayed-ack min
4230 */
4231 if (f_rtt < bbr_delayed_ack_time) {
4232 f_rtt = bbr_delayed_ack_time;
4233 }
4234 }
4235 /* Take the filter version or last measured pkt-rtt */
4236 if (rtt_type == BBR_RTT_PROP) {
4237 srtt = f_rtt;
4238 } else if (rtt_type == BBR_RTT_PKTRTT) {
4239 if (bbr->r_ctl.rc_pkt_epoch_rtt) {
4240 srtt = bbr->r_ctl.rc_pkt_epoch_rtt;
4241 } else {
4242 /* No pkt rtt yet */
4243 srtt = f_rtt;
4244 }
4245 } else if (rtt_type == BBR_RTT_RACK) {
4246 srtt = bbr->r_ctl.rc_last_rtt;
4247 /* We need to add in any internal delay for our timer */
4248 if (bbr->rc_ack_was_delayed)
4249 srtt += bbr->r_ctl.rc_ack_hdwr_delay;
4250 } else if (rtt_type == BBR_SRTT) {
4251 srtt = (TICKS_2_USEC(bbr->rc_tp->t_srtt) >> TCP_RTT_SHIFT);
4252 } else {
4253 /* TSNH */
4254 srtt = f_rtt;
4255 #ifdef BBR_INVARIANTS
4256 panic("Unknown rtt request type %d", rtt_type);
4257 #endif
4258 }
4259 return (srtt);
4260 }
4261
4262 static int
bbr_is_lost(struct tcp_bbr * bbr,struct bbr_sendmap * rsm,uint32_t cts)4263 bbr_is_lost(struct tcp_bbr *bbr, struct bbr_sendmap *rsm, uint32_t cts)
4264 {
4265 uint32_t thresh;
4266
4267 thresh = bbr_calc_thresh_rack(bbr, bbr_get_rtt(bbr, BBR_RTT_RACK),
4268 cts, rsm);
4269 if ((cts - rsm->r_tim_lastsent[(rsm->r_rtr_cnt - 1)]) >= thresh) {
4270 /* It is lost (past time) */
4271 return (1);
4272 }
4273 return (0);
4274 }
4275
4276 /*
4277 * Return a sendmap if we need to retransmit something.
4278 */
4279 static struct bbr_sendmap *
bbr_check_recovery_mode(struct tcpcb * tp,struct tcp_bbr * bbr,uint32_t cts)4280 bbr_check_recovery_mode(struct tcpcb *tp, struct tcp_bbr *bbr, uint32_t cts)
4281 {
4282 /*
4283 * Check to see that we don't need to fall into recovery. We will
4284 * need to do so if our oldest transmit is past the time we should
4285 * have had an ack.
4286 */
4287
4288 struct bbr_sendmap *rsm;
4289 int32_t idx;
4290
4291 if (TAILQ_EMPTY(&bbr->r_ctl.rc_map)) {
4292 /* Nothing outstanding that we know of */
4293 return (NULL);
4294 }
4295 rsm = TAILQ_FIRST(&bbr->r_ctl.rc_tmap);
4296 if (rsm == NULL) {
4297 /* Nothing in the transmit map */
4298 return (NULL);
4299 }
4300 if (tp->t_flags & TF_SENTFIN) {
4301 /* Fin restricted, don't find anything once a fin is sent */
4302 return (NULL);
4303 }
4304 if (rsm->r_flags & BBR_ACKED) {
4305 /*
4306 * Ok the first one is acked (this really should not happen
4307 * since we remove the from the tmap once they are acked)
4308 */
4309 rsm = bbr_find_lowest_rsm(bbr);
4310 if (rsm == NULL)
4311 return (NULL);
4312 }
4313 idx = rsm->r_rtr_cnt - 1;
4314 if (SEQ_LEQ(cts, rsm->r_tim_lastsent[idx])) {
4315 /* Send timestamp is the same or less? can't be ready */
4316 return (NULL);
4317 }
4318 /* Get our RTT time */
4319 if (bbr_is_lost(bbr, rsm, cts) &&
4320 ((rsm->r_dupack >= DUP_ACK_THRESHOLD) ||
4321 (rsm->r_flags & BBR_SACK_PASSED))) {
4322 if ((rsm->r_flags & BBR_MARKED_LOST) == 0) {
4323 rsm->r_flags |= BBR_MARKED_LOST;
4324 bbr->r_ctl.rc_lost += rsm->r_end - rsm->r_start;
4325 bbr->r_ctl.rc_lost_bytes += rsm->r_end - rsm->r_start;
4326 }
4327 bbr_cong_signal(tp, NULL, CC_NDUPACK, rsm);
4328 #ifdef BBR_INVARIANTS
4329 if ((rsm->r_end - rsm->r_start) == 0)
4330 panic("tp:%p bbr:%p rsm:%p length is 0?", tp, bbr, rsm);
4331 #endif
4332 return (rsm);
4333 }
4334 return (NULL);
4335 }
4336
4337 /*
4338 * RACK Timer, here we simply do logging and house keeping.
4339 * the normal bbr_output_wtime() function will call the
4340 * appropriate thing to check if we need to do a RACK retransmit.
4341 * We return 1, saying don't proceed with bbr_output_wtime only
4342 * when all timers have been stopped (destroyed PCB?).
4343 */
4344 static int
bbr_timeout_rack(struct tcpcb * tp,struct tcp_bbr * bbr,uint32_t cts)4345 bbr_timeout_rack(struct tcpcb *tp, struct tcp_bbr *bbr, uint32_t cts)
4346 {
4347 /*
4348 * This timer simply provides an internal trigger to send out data.
4349 * The check_recovery_mode call will see if there are needed
4350 * retransmissions, if so we will enter fast-recovery. The output
4351 * call may or may not do the same thing depending on sysctl
4352 * settings.
4353 */
4354 uint32_t lost;
4355
4356 if (bbr->rc_all_timers_stopped) {
4357 return (1);
4358 }
4359 if (TSTMP_LT(cts, bbr->r_ctl.rc_timer_exp)) {
4360 /* Its not time yet */
4361 return (0);
4362 }
4363 BBR_STAT_INC(bbr_to_tot);
4364 lost = bbr->r_ctl.rc_lost;
4365 if (bbr->r_state && (bbr->r_state != tp->t_state))
4366 bbr_set_state(tp, bbr, 0);
4367 bbr_log_to_event(bbr, cts, BBR_TO_FRM_RACK);
4368 if (bbr->r_ctl.rc_resend == NULL) {
4369 /* Lets do the check here */
4370 bbr->r_ctl.rc_resend = bbr_check_recovery_mode(tp, bbr, cts);
4371 }
4372 if (bbr_policer_call_from_rack_to)
4373 bbr_lt_bw_sampling(bbr, cts, (bbr->r_ctl.rc_lost > lost));
4374 bbr->r_ctl.rc_hpts_flags &= ~PACE_TMR_RACK;
4375 return (0);
4376 }
4377
4378 static __inline void
bbr_clone_rsm(struct tcp_bbr * bbr,struct bbr_sendmap * nrsm,struct bbr_sendmap * rsm,uint32_t start)4379 bbr_clone_rsm(struct tcp_bbr *bbr, struct bbr_sendmap *nrsm, struct bbr_sendmap *rsm, uint32_t start)
4380 {
4381 int idx;
4382
4383 nrsm->r_start = start;
4384 nrsm->r_end = rsm->r_end;
4385 nrsm->r_rtr_cnt = rsm->r_rtr_cnt;
4386 nrsm-> r_rtt_not_allowed = rsm->r_rtt_not_allowed;
4387 nrsm->r_flags = rsm->r_flags;
4388 /* We don't transfer forward the SYN flag */
4389 nrsm->r_flags &= ~BBR_HAS_SYN;
4390 /* We move forward the FIN flag, not that this should happen */
4391 rsm->r_flags &= ~BBR_HAS_FIN;
4392 nrsm->r_dupack = rsm->r_dupack;
4393 nrsm->r_rtr_bytes = 0;
4394 nrsm->r_is_gain = rsm->r_is_gain;
4395 nrsm->r_is_drain = rsm->r_is_drain;
4396 nrsm->r_delivered = rsm->r_delivered;
4397 nrsm->r_ts_valid = rsm->r_ts_valid;
4398 nrsm->r_del_ack_ts = rsm->r_del_ack_ts;
4399 nrsm->r_del_time = rsm->r_del_time;
4400 nrsm->r_app_limited = rsm->r_app_limited;
4401 nrsm->r_first_sent_time = rsm->r_first_sent_time;
4402 nrsm->r_flight_at_send = rsm->r_flight_at_send;
4403 /* We split a piece the lower section looses any just_ret flag. */
4404 nrsm->r_bbr_state = rsm->r_bbr_state;
4405 for (idx = 0; idx < nrsm->r_rtr_cnt; idx++) {
4406 nrsm->r_tim_lastsent[idx] = rsm->r_tim_lastsent[idx];
4407 }
4408 rsm->r_end = nrsm->r_start;
4409 idx = min((bbr->rc_tp->t_maxseg - bbr->rc_last_options), bbr->r_ctl.rc_pace_max_segs);
4410 idx /= 8;
4411 /* Check if we got too small */
4412 if ((rsm->r_is_smallmap == 0) &&
4413 ((rsm->r_end - rsm->r_start) <= idx)) {
4414 bbr->r_ctl.rc_num_small_maps_alloced++;
4415 rsm->r_is_smallmap = 1;
4416 }
4417 /* Check the new one as well */
4418 if ((nrsm->r_end - nrsm->r_start) <= idx) {
4419 bbr->r_ctl.rc_num_small_maps_alloced++;
4420 nrsm->r_is_smallmap = 1;
4421 }
4422 }
4423
4424 static int
bbr_sack_mergable(struct bbr_sendmap * at,uint32_t start,uint32_t end)4425 bbr_sack_mergable(struct bbr_sendmap *at,
4426 uint32_t start, uint32_t end)
4427 {
4428 /*
4429 * Given a sack block defined by
4430 * start and end, and a current position
4431 * at. Return 1 if either side of at
4432 * would show that the block is mergable
4433 * to that side. A block to be mergable
4434 * must have overlap with the start/end
4435 * and be in the SACK'd state.
4436 */
4437 struct bbr_sendmap *l_rsm;
4438 struct bbr_sendmap *r_rsm;
4439
4440 /* first get the either side blocks */
4441 l_rsm = TAILQ_PREV(at, bbr_head, r_next);
4442 r_rsm = TAILQ_NEXT(at, r_next);
4443 if (l_rsm && (l_rsm->r_flags & BBR_ACKED)) {
4444 /* Potentially mergeable */
4445 if ((l_rsm->r_end == start) ||
4446 (SEQ_LT(start, l_rsm->r_end) &&
4447 SEQ_GT(end, l_rsm->r_end))) {
4448 /*
4449 * map blk |------|
4450 * sack blk |------|
4451 * <or>
4452 * map blk |------|
4453 * sack blk |------|
4454 */
4455 return (1);
4456 }
4457 }
4458 if (r_rsm && (r_rsm->r_flags & BBR_ACKED)) {
4459 /* Potentially mergeable */
4460 if ((r_rsm->r_start == end) ||
4461 (SEQ_LT(start, r_rsm->r_start) &&
4462 SEQ_GT(end, r_rsm->r_start))) {
4463 /*
4464 * map blk |---------|
4465 * sack blk |----|
4466 * <or>
4467 * map blk |---------|
4468 * sack blk |-------|
4469 */
4470 return (1);
4471 }
4472 }
4473 return (0);
4474 }
4475
4476 static struct bbr_sendmap *
bbr_merge_rsm(struct tcp_bbr * bbr,struct bbr_sendmap * l_rsm,struct bbr_sendmap * r_rsm)4477 bbr_merge_rsm(struct tcp_bbr *bbr,
4478 struct bbr_sendmap *l_rsm,
4479 struct bbr_sendmap *r_rsm)
4480 {
4481 /*
4482 * We are merging two ack'd RSM's,
4483 * the l_rsm is on the left (lower seq
4484 * values) and the r_rsm is on the right
4485 * (higher seq value). The simplest way
4486 * to merge these is to move the right
4487 * one into the left. I don't think there
4488 * is any reason we need to try to find
4489 * the oldest (or last oldest retransmitted).
4490 */
4491 l_rsm->r_end = r_rsm->r_end;
4492 if (l_rsm->r_dupack < r_rsm->r_dupack)
4493 l_rsm->r_dupack = r_rsm->r_dupack;
4494 if (r_rsm->r_rtr_bytes)
4495 l_rsm->r_rtr_bytes += r_rsm->r_rtr_bytes;
4496 if (r_rsm->r_in_tmap) {
4497 /* This really should not happen */
4498 TAILQ_REMOVE(&bbr->r_ctl.rc_tmap, r_rsm, r_tnext);
4499 }
4500 if (r_rsm->r_app_limited)
4501 l_rsm->r_app_limited = r_rsm->r_app_limited;
4502 /* Now the flags */
4503 if (r_rsm->r_flags & BBR_HAS_FIN)
4504 l_rsm->r_flags |= BBR_HAS_FIN;
4505 if (r_rsm->r_flags & BBR_TLP)
4506 l_rsm->r_flags |= BBR_TLP;
4507 if (r_rsm->r_flags & BBR_RWND_COLLAPSED)
4508 l_rsm->r_flags |= BBR_RWND_COLLAPSED;
4509 if (r_rsm->r_flags & BBR_MARKED_LOST) {
4510 /* This really should not happen */
4511 bbr->r_ctl.rc_lost_bytes -= r_rsm->r_end - r_rsm->r_start;
4512 }
4513 TAILQ_REMOVE(&bbr->r_ctl.rc_map, r_rsm, r_next);
4514 if ((r_rsm->r_limit_type == 0) && (l_rsm->r_limit_type != 0)) {
4515 /* Transfer the split limit to the map we free */
4516 r_rsm->r_limit_type = l_rsm->r_limit_type;
4517 l_rsm->r_limit_type = 0;
4518 }
4519 bbr_free(bbr, r_rsm);
4520 return(l_rsm);
4521 }
4522
4523 /*
4524 * TLP Timer, here we simply setup what segment we want to
4525 * have the TLP expire on, the normal bbr_output_wtime() will then
4526 * send it out.
4527 *
4528 * We return 1, saying don't proceed with bbr_output_wtime only
4529 * when all timers have been stopped (destroyed PCB?).
4530 */
4531 static int
bbr_timeout_tlp(struct tcpcb * tp,struct tcp_bbr * bbr,uint32_t cts)4532 bbr_timeout_tlp(struct tcpcb *tp, struct tcp_bbr *bbr, uint32_t cts)
4533 {
4534 /*
4535 * Tail Loss Probe.
4536 */
4537 struct bbr_sendmap *rsm = NULL;
4538 struct socket *so;
4539 uint32_t amm;
4540 uint32_t out, avail;
4541 uint32_t maxseg;
4542 int collapsed_win = 0;
4543
4544 if (bbr->rc_all_timers_stopped) {
4545 return (1);
4546 }
4547 if (TSTMP_LT(cts, bbr->r_ctl.rc_timer_exp)) {
4548 /* Its not time yet */
4549 return (0);
4550 }
4551 if (ctf_progress_timeout_check(tp, true)) {
4552 bbr_log_progress_event(bbr, tp, tick, PROGRESS_DROP, __LINE__);
4553 return (-ETIMEDOUT); /* tcp_drop() */
4554 }
4555 /* Did we somehow get into persists? */
4556 if (bbr->rc_in_persist) {
4557 return (0);
4558 }
4559 if (bbr->r_state && (bbr->r_state != tp->t_state))
4560 bbr_set_state(tp, bbr, 0);
4561 BBR_STAT_INC(bbr_tlp_tot);
4562 maxseg = tp->t_maxseg - bbr->rc_last_options;
4563 /*
4564 * A TLP timer has expired. We have been idle for 2 rtts. So we now
4565 * need to figure out how to force a full MSS segment out.
4566 */
4567 so = tptosocket(tp);
4568 avail = sbavail(&so->so_snd);
4569 out = ctf_outstanding(tp);
4570 if (out > tp->snd_wnd) {
4571 /* special case, we need a retransmission */
4572 collapsed_win = 1;
4573 goto need_retran;
4574 }
4575 if (avail > out) {
4576 /* New data is available */
4577 amm = avail - out;
4578 if (amm > maxseg) {
4579 amm = maxseg;
4580 } else if ((amm < maxseg) && ((tp->t_flags & TF_NODELAY) == 0)) {
4581 /* not enough to fill a MTU and no-delay is off */
4582 goto need_retran;
4583 }
4584 /* Set the send-new override */
4585 if ((out + amm) <= tp->snd_wnd) {
4586 bbr->rc_tlp_new_data = 1;
4587 } else {
4588 goto need_retran;
4589 }
4590 bbr->r_ctl.rc_tlp_seg_send_cnt = 0;
4591 bbr->r_ctl.rc_last_tlp_seq = tp->snd_max;
4592 bbr->r_ctl.rc_tlp_send = NULL;
4593 /* cap any slots */
4594 BBR_STAT_INC(bbr_tlp_newdata);
4595 goto send;
4596 }
4597 need_retran:
4598 /*
4599 * Ok we need to arrange the last un-acked segment to be re-sent, or
4600 * optionally the first un-acked segment.
4601 */
4602 if (collapsed_win == 0) {
4603 rsm = TAILQ_LAST_FAST(&bbr->r_ctl.rc_map, bbr_sendmap, r_next);
4604 if (rsm && (rsm->r_flags & (BBR_ACKED | BBR_HAS_FIN))) {
4605 rsm = bbr_find_high_nonack(bbr, rsm);
4606 }
4607 if (rsm == NULL) {
4608 goto restore;
4609 }
4610 } else {
4611 /*
4612 * We must find the last segment
4613 * that was acceptable by the client.
4614 */
4615 TAILQ_FOREACH_REVERSE(rsm, &bbr->r_ctl.rc_map, bbr_head, r_next) {
4616 if ((rsm->r_flags & BBR_RWND_COLLAPSED) == 0) {
4617 /* Found one */
4618 break;
4619 }
4620 }
4621 if (rsm == NULL) {
4622 /* None? if so send the first */
4623 rsm = TAILQ_FIRST(&bbr->r_ctl.rc_map);
4624 if (rsm == NULL)
4625 goto restore;
4626 }
4627 }
4628 if ((rsm->r_end - rsm->r_start) > maxseg) {
4629 /*
4630 * We need to split this the last segment in two.
4631 */
4632 struct bbr_sendmap *nrsm;
4633
4634 nrsm = bbr_alloc_full_limit(bbr);
4635 if (nrsm == NULL) {
4636 /*
4637 * We can't get memory to split, we can either just
4638 * not split it. Or retransmit the whole piece, lets
4639 * do the large send (BTLP :-) ).
4640 */
4641 goto go_for_it;
4642 }
4643 bbr_clone_rsm(bbr, nrsm, rsm, (rsm->r_end - maxseg));
4644 TAILQ_INSERT_AFTER(&bbr->r_ctl.rc_map, rsm, nrsm, r_next);
4645 if (rsm->r_in_tmap) {
4646 TAILQ_INSERT_AFTER(&bbr->r_ctl.rc_tmap, rsm, nrsm, r_tnext);
4647 nrsm->r_in_tmap = 1;
4648 }
4649 rsm->r_flags &= (~BBR_HAS_FIN);
4650 rsm = nrsm;
4651 }
4652 go_for_it:
4653 bbr->r_ctl.rc_tlp_send = rsm;
4654 bbr->rc_tlp_rtx_out = 1;
4655 if (rsm->r_start == bbr->r_ctl.rc_last_tlp_seq) {
4656 bbr->r_ctl.rc_tlp_seg_send_cnt++;
4657 tp->t_rxtshift++;
4658 } else {
4659 bbr->r_ctl.rc_last_tlp_seq = rsm->r_start;
4660 bbr->r_ctl.rc_tlp_seg_send_cnt = 1;
4661 }
4662 send:
4663 if (bbr->r_ctl.rc_tlp_seg_send_cnt > bbr_tlp_max_resend) {
4664 /*
4665 * Can't [re]/transmit a segment we have retransmitted the
4666 * max times. We need the retransmit timer to take over.
4667 */
4668 restore:
4669 bbr->rc_tlp_new_data = 0;
4670 bbr->r_ctl.rc_tlp_send = NULL;
4671 if (rsm)
4672 rsm->r_flags &= ~BBR_TLP;
4673 BBR_STAT_INC(bbr_tlp_retran_fail);
4674 return (0);
4675 } else if (rsm) {
4676 rsm->r_flags |= BBR_TLP;
4677 }
4678 if (rsm && (rsm->r_start == bbr->r_ctl.rc_last_tlp_seq) &&
4679 (bbr->r_ctl.rc_tlp_seg_send_cnt > bbr_tlp_max_resend)) {
4680 /*
4681 * We have retransmitted to many times for TLP. Switch to
4682 * the regular RTO timer
4683 */
4684 goto restore;
4685 }
4686 bbr_log_to_event(bbr, cts, BBR_TO_FRM_TLP);
4687 bbr->r_ctl.rc_hpts_flags &= ~PACE_TMR_TLP;
4688 return (0);
4689 }
4690
4691 /*
4692 * Delayed ack Timer, here we simply need to setup the
4693 * ACK_NOW flag and remove the DELACK flag. From there
4694 * the output routine will send the ack out.
4695 *
4696 * We only return 1, saying don't proceed, if all timers
4697 * are stopped (destroyed PCB?).
4698 */
4699 static int
bbr_timeout_delack(struct tcpcb * tp,struct tcp_bbr * bbr,uint32_t cts)4700 bbr_timeout_delack(struct tcpcb *tp, struct tcp_bbr *bbr, uint32_t cts)
4701 {
4702 if (bbr->rc_all_timers_stopped) {
4703 return (1);
4704 }
4705 bbr_log_to_event(bbr, cts, BBR_TO_FRM_DELACK);
4706 tp->t_flags &= ~TF_DELACK;
4707 tp->t_flags |= TF_ACKNOW;
4708 KMOD_TCPSTAT_INC(tcps_delack);
4709 bbr->r_ctl.rc_hpts_flags &= ~PACE_TMR_DELACK;
4710 return (0);
4711 }
4712
4713 /*
4714 * Here we send a KEEP-ALIVE like probe to the
4715 * peer, we do not send data.
4716 *
4717 * We only return 1, saying don't proceed, if all timers
4718 * are stopped (destroyed PCB?).
4719 */
4720 static int
bbr_timeout_persist(struct tcpcb * tp,struct tcp_bbr * bbr,uint32_t cts)4721 bbr_timeout_persist(struct tcpcb *tp, struct tcp_bbr *bbr, uint32_t cts)
4722 {
4723 struct tcptemp *t_template;
4724 int32_t retval = 1;
4725
4726 if (bbr->rc_all_timers_stopped) {
4727 return (1);
4728 }
4729 if (bbr->rc_in_persist == 0)
4730 return (0);
4731
4732 /*
4733 * Persistence timer into zero window. Force a byte to be output, if
4734 * possible.
4735 */
4736 bbr_log_to_event(bbr, cts, BBR_TO_FRM_PERSIST);
4737 bbr->r_ctl.rc_hpts_flags &= ~PACE_TMR_PERSIT;
4738 KMOD_TCPSTAT_INC(tcps_persisttimeo);
4739 /*
4740 * Have we exceeded the user specified progress time?
4741 */
4742 if (ctf_progress_timeout_check(tp, true)) {
4743 bbr_log_progress_event(bbr, tp, tick, PROGRESS_DROP, __LINE__);
4744 return (-ETIMEDOUT); /* tcp_drop() */
4745 }
4746 /*
4747 * Hack: if the peer is dead/unreachable, we do not time out if the
4748 * window is closed. After a full backoff, drop the connection if
4749 * the idle time (no responses to probes) reaches the maximum
4750 * backoff that we would use if retransmitting.
4751 */
4752 if (tp->t_rxtshift >= V_tcp_retries &&
4753 (ticks - tp->t_rcvtime >= tcp_maxpersistidle ||
4754 ticks - tp->t_rcvtime >= TCP_REXMTVAL(tp) * tcp_totbackoff)) {
4755 KMOD_TCPSTAT_INC(tcps_persistdrop);
4756 tcp_log_end_status(tp, TCP_EI_STATUS_PERSIST_MAX);
4757 return (-ETIMEDOUT); /* tcp_drop() */
4758 }
4759 if ((sbavail(&bbr->rc_inp->inp_socket->so_snd) == 0) &&
4760 tp->snd_una == tp->snd_max) {
4761 bbr_exit_persist(tp, bbr, cts, __LINE__);
4762 retval = 0;
4763 goto out;
4764 }
4765 /*
4766 * If the user has closed the socket then drop a persisting
4767 * connection after a much reduced timeout.
4768 */
4769 if (tp->t_state > TCPS_CLOSE_WAIT &&
4770 (ticks - tp->t_rcvtime) >= TCPTV_PERSMAX) {
4771 KMOD_TCPSTAT_INC(tcps_persistdrop);
4772 tcp_log_end_status(tp, TCP_EI_STATUS_PERSIST_MAX);
4773 return (-ETIMEDOUT); /* tcp_drop() */
4774 }
4775 t_template = tcpip_maketemplate(bbr->rc_inp);
4776 if (t_template) {
4777 tcp_respond(tp, t_template->tt_ipgen,
4778 &t_template->tt_t, (struct mbuf *)NULL,
4779 tp->rcv_nxt, tp->snd_una - 1, 0);
4780 /* This sends an ack */
4781 if (tp->t_flags & TF_DELACK)
4782 tp->t_flags &= ~TF_DELACK;
4783 free(t_template, M_TEMP);
4784 }
4785 if (tp->t_rxtshift < V_tcp_retries)
4786 tp->t_rxtshift++;
4787 bbr_start_hpts_timer(bbr, tp, cts, 3, 0, 0);
4788 out:
4789 return (retval);
4790 }
4791
4792 /*
4793 * If a keepalive goes off, we had no other timers
4794 * happening. We always return 1 here since this
4795 * routine either drops the connection or sends
4796 * out a segment with respond.
4797 */
4798 static int
bbr_timeout_keepalive(struct tcpcb * tp,struct tcp_bbr * bbr,uint32_t cts)4799 bbr_timeout_keepalive(struct tcpcb *tp, struct tcp_bbr *bbr, uint32_t cts)
4800 {
4801 struct tcptemp *t_template;
4802 struct inpcb *inp = tptoinpcb(tp);
4803
4804 if (bbr->rc_all_timers_stopped) {
4805 return (1);
4806 }
4807 bbr->r_ctl.rc_hpts_flags &= ~PACE_TMR_KEEP;
4808 bbr_log_to_event(bbr, cts, BBR_TO_FRM_KEEP);
4809 /*
4810 * Keep-alive timer went off; send something or drop connection if
4811 * idle for too long.
4812 */
4813 KMOD_TCPSTAT_INC(tcps_keeptimeo);
4814 if (tp->t_state < TCPS_ESTABLISHED)
4815 goto dropit;
4816 if ((V_tcp_always_keepalive || inp->inp_socket->so_options & SO_KEEPALIVE) &&
4817 tp->t_state <= TCPS_CLOSING) {
4818 if (ticks - tp->t_rcvtime >= TP_KEEPIDLE(tp) + TP_MAXIDLE(tp))
4819 goto dropit;
4820 /*
4821 * Send a packet designed to force a response if the peer is
4822 * up and reachable: either an ACK if the connection is
4823 * still alive, or an RST if the peer has closed the
4824 * connection due to timeout or reboot. Using sequence
4825 * number tp->snd_una-1 causes the transmitted zero-length
4826 * segment to lie outside the receive window; by the
4827 * protocol spec, this requires the correspondent TCP to
4828 * respond.
4829 */
4830 KMOD_TCPSTAT_INC(tcps_keepprobe);
4831 t_template = tcpip_maketemplate(inp);
4832 if (t_template) {
4833 tcp_respond(tp, t_template->tt_ipgen,
4834 &t_template->tt_t, (struct mbuf *)NULL,
4835 tp->rcv_nxt, tp->snd_una - 1, 0);
4836 free(t_template, M_TEMP);
4837 }
4838 }
4839 bbr_start_hpts_timer(bbr, tp, cts, 4, 0, 0);
4840 return (1);
4841 dropit:
4842 KMOD_TCPSTAT_INC(tcps_keepdrops);
4843 tcp_log_end_status(tp, TCP_EI_STATUS_KEEP_MAX);
4844 return (-ETIMEDOUT); /* tcp_drop() */
4845 }
4846
4847 /*
4848 * Retransmit helper function, clear up all the ack
4849 * flags and take care of important book keeping.
4850 */
4851 static void
bbr_remxt_tmr(struct tcpcb * tp)4852 bbr_remxt_tmr(struct tcpcb *tp)
4853 {
4854 /*
4855 * The retransmit timer went off, all sack'd blocks must be
4856 * un-acked.
4857 */
4858 struct bbr_sendmap *rsm, *trsm = NULL;
4859 struct tcp_bbr *bbr;
4860 uint32_t cts, lost;
4861
4862 bbr = (struct tcp_bbr *)tp->t_fb_ptr;
4863 cts = tcp_get_usecs(&bbr->rc_tv);
4864 lost = bbr->r_ctl.rc_lost;
4865 if (bbr->r_state && (bbr->r_state != tp->t_state))
4866 bbr_set_state(tp, bbr, 0);
4867
4868 TAILQ_FOREACH(rsm, &bbr->r_ctl.rc_map, r_next) {
4869 if (rsm->r_flags & BBR_ACKED) {
4870 uint32_t old_flags;
4871
4872 rsm->r_dupack = 0;
4873 if (rsm->r_in_tmap == 0) {
4874 /* We must re-add it back to the tlist */
4875 if (trsm == NULL) {
4876 TAILQ_INSERT_HEAD(&bbr->r_ctl.rc_tmap, rsm, r_tnext);
4877 } else {
4878 TAILQ_INSERT_AFTER(&bbr->r_ctl.rc_tmap, trsm, rsm, r_tnext);
4879 }
4880 rsm->r_in_tmap = 1;
4881 }
4882 old_flags = rsm->r_flags;
4883 rsm->r_flags |= BBR_RXT_CLEARED;
4884 rsm->r_flags &= ~(BBR_ACKED | BBR_SACK_PASSED | BBR_WAS_SACKPASS);
4885 bbr_log_type_rsmclear(bbr, cts, rsm, old_flags, __LINE__);
4886 } else {
4887 if ((tp->t_state < TCPS_ESTABLISHED) &&
4888 (rsm->r_start == tp->snd_una)) {
4889 /*
4890 * Special case for TCP FO. Where
4891 * we sent more data beyond the snd_max.
4892 * We don't mark that as lost and stop here.
4893 */
4894 break;
4895 }
4896 if ((rsm->r_flags & BBR_MARKED_LOST) == 0) {
4897 bbr->r_ctl.rc_lost += rsm->r_end - rsm->r_start;
4898 bbr->r_ctl.rc_lost_bytes += rsm->r_end - rsm->r_start;
4899 }
4900 if (bbr_marks_rxt_sack_passed) {
4901 /*
4902 * With this option, we will rack out
4903 * in 1ms increments the rest of the packets.
4904 */
4905 rsm->r_flags |= BBR_SACK_PASSED | BBR_MARKED_LOST;
4906 rsm->r_flags &= ~BBR_WAS_SACKPASS;
4907 } else {
4908 /*
4909 * With this option we only mark them lost
4910 * and remove all sack'd markings. We will run
4911 * another RXT or a TLP. This will cause
4912 * us to eventually send more based on what
4913 * ack's come in.
4914 */
4915 rsm->r_flags |= BBR_MARKED_LOST;
4916 rsm->r_flags &= ~BBR_WAS_SACKPASS;
4917 rsm->r_flags &= ~BBR_SACK_PASSED;
4918 }
4919 }
4920 trsm = rsm;
4921 }
4922 bbr->r_ctl.rc_resend = TAILQ_FIRST(&bbr->r_ctl.rc_map);
4923 /* Clear the count (we just un-acked them) */
4924 bbr_log_to_event(bbr, cts, BBR_TO_FRM_TMR);
4925 bbr->rc_tlp_new_data = 0;
4926 bbr->r_ctl.rc_tlp_seg_send_cnt = 0;
4927 /* zap the behindness on a rxt */
4928 bbr->r_ctl.rc_hptsi_agg_delay = 0;
4929 bbr->r_agg_early_set = 0;
4930 bbr->r_ctl.rc_agg_early = 0;
4931 bbr->rc_tlp_rtx_out = 0;
4932 bbr->r_ctl.rc_sacked = 0;
4933 bbr->r_ctl.rc_sacklast = NULL;
4934 bbr->r_timer_override = 1;
4935 bbr_lt_bw_sampling(bbr, cts, (bbr->r_ctl.rc_lost > lost));
4936 }
4937
4938 /*
4939 * Re-transmit timeout! If we drop the PCB we will return 1, otherwise
4940 * we will setup to retransmit the lowest seq number outstanding.
4941 */
4942 static int
bbr_timeout_rxt(struct tcpcb * tp,struct tcp_bbr * bbr,uint32_t cts)4943 bbr_timeout_rxt(struct tcpcb *tp, struct tcp_bbr *bbr, uint32_t cts)
4944 {
4945 struct inpcb *inp = tptoinpcb(tp);
4946 int32_t rexmt;
4947 int32_t retval = 0;
4948 bool isipv6;
4949
4950 bbr->r_ctl.rc_hpts_flags &= ~PACE_TMR_RXT;
4951 if (bbr->rc_all_timers_stopped) {
4952 return (1);
4953 }
4954 if (TCPS_HAVEESTABLISHED(tp->t_state) &&
4955 (tp->snd_una == tp->snd_max)) {
4956 /* Nothing outstanding .. nothing to do */
4957 return (0);
4958 }
4959 /*
4960 * Retransmission timer went off. Message has not been acked within
4961 * retransmit interval. Back off to a longer retransmit interval
4962 * and retransmit one segment.
4963 */
4964 if (ctf_progress_timeout_check(tp, true)) {
4965 bbr_log_progress_event(bbr, tp, tick, PROGRESS_DROP, __LINE__);
4966 return (-ETIMEDOUT); /* tcp_drop() */
4967 }
4968 bbr_remxt_tmr(tp);
4969 if ((bbr->r_ctl.rc_resend == NULL) ||
4970 ((bbr->r_ctl.rc_resend->r_flags & BBR_RWND_COLLAPSED) == 0)) {
4971 /*
4972 * If the rwnd collapsed on
4973 * the one we are retransmitting
4974 * it does not count against the
4975 * rxt count.
4976 */
4977 tp->t_rxtshift++;
4978 }
4979 if (tp->t_rxtshift > V_tcp_retries) {
4980 tp->t_rxtshift = V_tcp_retries;
4981 KMOD_TCPSTAT_INC(tcps_timeoutdrop);
4982 tcp_log_end_status(tp, TCP_EI_STATUS_RETRAN);
4983 /* XXXGL: previously t_softerror was casted to uint16_t */
4984 MPASS(tp->t_softerror >= 0);
4985 retval = tp->t_softerror ? -tp->t_softerror : -ETIMEDOUT;
4986 return (retval); /* tcp_drop() */
4987 }
4988 if (tp->t_state == TCPS_SYN_SENT) {
4989 /*
4990 * If the SYN was retransmitted, indicate CWND to be limited
4991 * to 1 segment in cc_conn_init().
4992 */
4993 tp->snd_cwnd = 1;
4994 } else if (tp->t_rxtshift == 1) {
4995 /*
4996 * first retransmit; record ssthresh and cwnd so they can be
4997 * recovered if this turns out to be a "bad" retransmit. A
4998 * retransmit is considered "bad" if an ACK for this segment
4999 * is received within RTT/2 interval; the assumption here is
5000 * that the ACK was already in flight. See "On Estimating
5001 * End-to-End Network Path Properties" by Allman and Paxson
5002 * for more details.
5003 */
5004 tp->snd_cwnd = tp->t_maxseg - bbr->rc_last_options;
5005 if (!IN_RECOVERY(tp->t_flags)) {
5006 tp->snd_cwnd_prev = tp->snd_cwnd;
5007 tp->snd_ssthresh_prev = tp->snd_ssthresh;
5008 tp->snd_recover_prev = tp->snd_recover;
5009 tp->t_badrxtwin = ticks + (tp->t_srtt >> (TCP_RTT_SHIFT + 1));
5010 tp->t_flags |= TF_PREVVALID;
5011 } else {
5012 tp->t_flags &= ~TF_PREVVALID;
5013 }
5014 tp->snd_cwnd = tp->t_maxseg - bbr->rc_last_options;
5015 } else {
5016 tp->snd_cwnd = tp->t_maxseg - bbr->rc_last_options;
5017 tp->t_flags &= ~TF_PREVVALID;
5018 }
5019 KMOD_TCPSTAT_INC(tcps_rexmttimeo);
5020 if ((tp->t_state == TCPS_SYN_SENT) ||
5021 (tp->t_state == TCPS_SYN_RECEIVED))
5022 rexmt = USEC_2_TICKS(BBR_INITIAL_RTO) * tcp_backoff[tp->t_rxtshift];
5023 else
5024 rexmt = TCP_REXMTVAL(tp) * tcp_backoff[tp->t_rxtshift];
5025 TCPT_RANGESET(tp->t_rxtcur, rexmt,
5026 MSEC_2_TICKS(bbr->r_ctl.rc_min_rto_ms),
5027 MSEC_2_TICKS(((uint32_t)bbr->rc_max_rto_sec) * 1000));
5028 /*
5029 * We enter the path for PLMTUD if connection is established or, if
5030 * connection is FIN_WAIT_1 status, reason for the last is that if
5031 * amount of data we send is very small, we could send it in couple
5032 * of packets and process straight to FIN. In that case we won't
5033 * catch ESTABLISHED state.
5034 */
5035 #ifdef INET6
5036 isipv6 = (inp->inp_vflag & INP_IPV6) ? true : false;
5037 #else
5038 isipv6 = false;
5039 #endif
5040 if (((V_tcp_pmtud_blackhole_detect == 1) ||
5041 (V_tcp_pmtud_blackhole_detect == 2 && !isipv6) ||
5042 (V_tcp_pmtud_blackhole_detect == 3 && isipv6)) &&
5043 ((tp->t_state == TCPS_ESTABLISHED) ||
5044 (tp->t_state == TCPS_FIN_WAIT_1))) {
5045 /*
5046 * Idea here is that at each stage of mtu probe (usually,
5047 * 1448 -> 1188 -> 524) should be given 2 chances to recover
5048 * before further clamping down. 'tp->t_rxtshift % 2 == 0'
5049 * should take care of that.
5050 */
5051 if (((tp->t_flags2 & (TF2_PLPMTU_PMTUD | TF2_PLPMTU_MAXSEGSNT)) ==
5052 (TF2_PLPMTU_PMTUD | TF2_PLPMTU_MAXSEGSNT)) &&
5053 (tp->t_rxtshift >= 2 && tp->t_rxtshift < 6 &&
5054 tp->t_rxtshift % 2 == 0)) {
5055 /*
5056 * Enter Path MTU Black-hole Detection mechanism: -
5057 * Disable Path MTU Discovery (IP "DF" bit). -
5058 * Reduce MTU to lower value than what we negotiated
5059 * with peer.
5060 */
5061 if ((tp->t_flags2 & TF2_PLPMTU_BLACKHOLE) == 0) {
5062 /*
5063 * Record that we may have found a black
5064 * hole.
5065 */
5066 tp->t_flags2 |= TF2_PLPMTU_BLACKHOLE;
5067 /* Keep track of previous MSS. */
5068 tp->t_pmtud_saved_maxseg = tp->t_maxseg;
5069 }
5070 /*
5071 * Reduce the MSS to blackhole value or to the
5072 * default in an attempt to retransmit.
5073 */
5074 #ifdef INET6
5075 isipv6 = bbr->r_is_v6;
5076 if (isipv6 &&
5077 tp->t_maxseg > V_tcp_v6pmtud_blackhole_mss) {
5078 /* Use the sysctl tuneable blackhole MSS. */
5079 tp->t_maxseg = V_tcp_v6pmtud_blackhole_mss;
5080 KMOD_TCPSTAT_INC(tcps_pmtud_blackhole_activated);
5081 } else if (isipv6) {
5082 /* Use the default MSS. */
5083 tp->t_maxseg = V_tcp_v6mssdflt;
5084 /*
5085 * Disable Path MTU Discovery when we switch
5086 * to minmss.
5087 */
5088 tp->t_flags2 &= ~TF2_PLPMTU_PMTUD;
5089 KMOD_TCPSTAT_INC(tcps_pmtud_blackhole_activated_min_mss);
5090 }
5091 #endif
5092 #if defined(INET6) && defined(INET)
5093 else
5094 #endif
5095 #ifdef INET
5096 if (tp->t_maxseg > V_tcp_pmtud_blackhole_mss) {
5097 /* Use the sysctl tuneable blackhole MSS. */
5098 tp->t_maxseg = V_tcp_pmtud_blackhole_mss;
5099 KMOD_TCPSTAT_INC(tcps_pmtud_blackhole_activated);
5100 } else {
5101 /* Use the default MSS. */
5102 tp->t_maxseg = V_tcp_mssdflt;
5103 /*
5104 * Disable Path MTU Discovery when we switch
5105 * to minmss.
5106 */
5107 tp->t_flags2 &= ~TF2_PLPMTU_PMTUD;
5108 KMOD_TCPSTAT_INC(tcps_pmtud_blackhole_activated_min_mss);
5109 }
5110 #endif
5111 } else {
5112 /*
5113 * If further retransmissions are still unsuccessful
5114 * with a lowered MTU, maybe this isn't a blackhole
5115 * and we restore the previous MSS and blackhole
5116 * detection flags. The limit '6' is determined by
5117 * giving each probe stage (1448, 1188, 524) 2
5118 * chances to recover.
5119 */
5120 if ((tp->t_flags2 & TF2_PLPMTU_BLACKHOLE) &&
5121 (tp->t_rxtshift >= 6)) {
5122 tp->t_flags2 |= TF2_PLPMTU_PMTUD;
5123 tp->t_flags2 &= ~TF2_PLPMTU_BLACKHOLE;
5124 tp->t_maxseg = tp->t_pmtud_saved_maxseg;
5125 if (tp->t_maxseg < V_tcp_mssdflt) {
5126 /*
5127 * The MSS is so small we should not
5128 * process incoming SACK's since we are
5129 * subject to attack in such a case.
5130 */
5131 tp->t_flags2 |= TF2_PROC_SACK_PROHIBIT;
5132 } else {
5133 tp->t_flags2 &= ~TF2_PROC_SACK_PROHIBIT;
5134 }
5135 KMOD_TCPSTAT_INC(tcps_pmtud_blackhole_failed);
5136 }
5137 }
5138 }
5139 /*
5140 * Disable RFC1323 and SACK if we haven't got any response to our
5141 * third SYN to work-around some broken terminal servers (most of
5142 * which have hopefully been retired) that have bad VJ header
5143 * compression code which trashes TCP segments containing
5144 * unknown-to-them TCP options.
5145 */
5146 if (tcp_rexmit_drop_options && (tp->t_state == TCPS_SYN_SENT) &&
5147 (tp->t_rxtshift == 3))
5148 tp->t_flags &= ~(TF_REQ_SCALE | TF_REQ_TSTMP | TF_SACK_PERMIT);
5149 /*
5150 * If we backed off this far, our srtt estimate is probably bogus.
5151 * Clobber it so we'll take the next rtt measurement as our srtt;
5152 * move the current srtt into rttvar to keep the current retransmit
5153 * times until then.
5154 */
5155 if (tp->t_rxtshift > TCP_MAXRXTSHIFT / 4) {
5156 #ifdef INET6
5157 if (bbr->r_is_v6)
5158 in6_losing(inp);
5159 else
5160 #endif
5161 in_losing(inp);
5162 tp->t_rttvar += (tp->t_srtt >> TCP_RTT_SHIFT);
5163 tp->t_srtt = 0;
5164 }
5165 sack_filter_clear(&bbr->r_ctl.bbr_sf, tp->snd_una);
5166 tp->snd_recover = tp->snd_max;
5167 tp->t_flags |= TF_ACKNOW;
5168 tp->t_rtttime = 0;
5169
5170 return (retval);
5171 }
5172
5173 static int
bbr_process_timers(struct tcpcb * tp,struct tcp_bbr * bbr,uint32_t cts,uint8_t hpts_calling)5174 bbr_process_timers(struct tcpcb *tp, struct tcp_bbr *bbr, uint32_t cts, uint8_t hpts_calling)
5175 {
5176 int32_t ret = 0;
5177 int32_t timers = (bbr->r_ctl.rc_hpts_flags & PACE_TMR_MASK);
5178
5179 if (timers == 0) {
5180 return (0);
5181 }
5182 if (tp->t_state == TCPS_LISTEN) {
5183 /* no timers on listen sockets */
5184 if (bbr->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT)
5185 return (0);
5186 return (1);
5187 }
5188 if (TSTMP_LT(cts, bbr->r_ctl.rc_timer_exp)) {
5189 uint32_t left;
5190
5191 if (bbr->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT) {
5192 ret = -1;
5193 bbr_log_to_processing(bbr, cts, ret, 0, hpts_calling);
5194 return (0);
5195 }
5196 if (hpts_calling == 0) {
5197 ret = -2;
5198 bbr_log_to_processing(bbr, cts, ret, 0, hpts_calling);
5199 return (0);
5200 }
5201 /*
5202 * Ok our timer went off early and we are not paced false
5203 * alarm, go back to sleep.
5204 */
5205 left = bbr->r_ctl.rc_timer_exp - cts;
5206 ret = -3;
5207 bbr_log_to_processing(bbr, cts, ret, left, hpts_calling);
5208 tcp_hpts_insert(tp, HPTS_USEC_TO_SLOTS(left));
5209 return (1);
5210 }
5211 bbr->rc_tmr_stopped = 0;
5212 bbr->r_ctl.rc_hpts_flags &= ~PACE_TMR_MASK;
5213 if (timers & PACE_TMR_DELACK) {
5214 ret = bbr_timeout_delack(tp, bbr, cts);
5215 } else if (timers & PACE_TMR_PERSIT) {
5216 ret = bbr_timeout_persist(tp, bbr, cts);
5217 } else if (timers & PACE_TMR_RACK) {
5218 bbr->r_ctl.rc_tlp_rxt_last_time = cts;
5219 ret = bbr_timeout_rack(tp, bbr, cts);
5220 } else if (timers & PACE_TMR_TLP) {
5221 bbr->r_ctl.rc_tlp_rxt_last_time = cts;
5222 ret = bbr_timeout_tlp(tp, bbr, cts);
5223 } else if (timers & PACE_TMR_RXT) {
5224 bbr->r_ctl.rc_tlp_rxt_last_time = cts;
5225 ret = bbr_timeout_rxt(tp, bbr, cts);
5226 } else if (timers & PACE_TMR_KEEP) {
5227 ret = bbr_timeout_keepalive(tp, bbr, cts);
5228 }
5229 bbr_log_to_processing(bbr, cts, ret, timers, hpts_calling);
5230 return (ret);
5231 }
5232
5233 static void
bbr_timer_cancel(struct tcp_bbr * bbr,int32_t line,uint32_t cts)5234 bbr_timer_cancel(struct tcp_bbr *bbr, int32_t line, uint32_t cts)
5235 {
5236 if (bbr->r_ctl.rc_hpts_flags & PACE_TMR_MASK) {
5237 uint8_t hpts_removed = 0;
5238
5239 if (tcp_in_hpts(bbr->rc_tp) &&
5240 (bbr->rc_timer_first == 1)) {
5241 /*
5242 * If we are canceling timer's when we have the
5243 * timer ahead of the output being paced. We also
5244 * must remove ourselves from the hpts.
5245 */
5246 hpts_removed = 1;
5247 tcp_hpts_remove(bbr->rc_tp);
5248 if (bbr->r_ctl.rc_last_delay_val) {
5249 /* Update the last hptsi delay too */
5250 uint32_t time_since_send;
5251
5252 if (TSTMP_GT(cts, bbr->rc_pacer_started))
5253 time_since_send = cts - bbr->rc_pacer_started;
5254 else
5255 time_since_send = 0;
5256 if (bbr->r_ctl.rc_last_delay_val > time_since_send) {
5257 /* Cut down our slot time */
5258 bbr->r_ctl.rc_last_delay_val -= time_since_send;
5259 } else {
5260 bbr->r_ctl.rc_last_delay_val = 0;
5261 }
5262 bbr->rc_pacer_started = cts;
5263 }
5264 }
5265 bbr->rc_timer_first = 0;
5266 bbr_log_to_cancel(bbr, line, cts, hpts_removed);
5267 bbr->rc_tmr_stopped = bbr->r_ctl.rc_hpts_flags & PACE_TMR_MASK;
5268 bbr->r_ctl.rc_hpts_flags &= ~(PACE_TMR_MASK);
5269 }
5270 }
5271
5272 static int
bbr_stopall(struct tcpcb * tp)5273 bbr_stopall(struct tcpcb *tp)
5274 {
5275 struct tcp_bbr *bbr;
5276
5277 bbr = (struct tcp_bbr *)tp->t_fb_ptr;
5278 bbr->rc_all_timers_stopped = 1;
5279
5280 tcp_hpts_remove(tp);
5281
5282 return (0);
5283 }
5284
5285 static uint32_t
bbr_get_earliest_send_outstanding(struct tcp_bbr * bbr,struct bbr_sendmap * u_rsm,uint32_t cts)5286 bbr_get_earliest_send_outstanding(struct tcp_bbr *bbr, struct bbr_sendmap *u_rsm, uint32_t cts)
5287 {
5288 struct bbr_sendmap *rsm;
5289
5290 rsm = TAILQ_FIRST(&bbr->r_ctl.rc_tmap);
5291 if ((rsm == NULL) || (u_rsm == rsm))
5292 return (cts);
5293 return(rsm->r_tim_lastsent[(rsm->r_rtr_cnt-1)]);
5294 }
5295
5296 static void
bbr_update_rsm(struct tcpcb * tp,struct tcp_bbr * bbr,struct bbr_sendmap * rsm,uint32_t cts,uint32_t pacing_time)5297 bbr_update_rsm(struct tcpcb *tp, struct tcp_bbr *bbr,
5298 struct bbr_sendmap *rsm, uint32_t cts, uint32_t pacing_time)
5299 {
5300 int32_t idx;
5301
5302 rsm->r_rtr_cnt++;
5303 rsm->r_dupack = 0;
5304 if (rsm->r_rtr_cnt > BBR_NUM_OF_RETRANS) {
5305 rsm->r_rtr_cnt = BBR_NUM_OF_RETRANS;
5306 rsm->r_flags |= BBR_OVERMAX;
5307 }
5308 if (rsm->r_flags & BBR_RWND_COLLAPSED) {
5309 /* Take off the collapsed flag at rxt */
5310 rsm->r_flags &= ~BBR_RWND_COLLAPSED;
5311 }
5312 if (rsm->r_flags & BBR_MARKED_LOST) {
5313 /* We have retransmitted, its no longer lost */
5314 rsm->r_flags &= ~BBR_MARKED_LOST;
5315 bbr->r_ctl.rc_lost_bytes -= rsm->r_end - rsm->r_start;
5316 }
5317 if (rsm->r_flags & BBR_RXT_CLEARED) {
5318 /*
5319 * We hit a RXT timer on it and
5320 * we cleared the "acked" flag.
5321 * We now have it going back into
5322 * flight, we can remove the cleared
5323 * flag and possibly do accounting on
5324 * this piece.
5325 */
5326 rsm->r_flags &= ~BBR_RXT_CLEARED;
5327 }
5328 if ((rsm->r_rtr_cnt > 1) && ((rsm->r_flags & BBR_TLP) == 0)) {
5329 bbr->r_ctl.rc_holes_rxt += (rsm->r_end - rsm->r_start);
5330 rsm->r_rtr_bytes += (rsm->r_end - rsm->r_start);
5331 }
5332 idx = rsm->r_rtr_cnt - 1;
5333 rsm->r_tim_lastsent[idx] = cts;
5334 rsm->r_pacing_delay = pacing_time;
5335 rsm->r_delivered = bbr->r_ctl.rc_delivered;
5336 rsm->r_ts_valid = bbr->rc_ts_valid;
5337 if (bbr->rc_ts_valid)
5338 rsm->r_del_ack_ts = bbr->r_ctl.last_inbound_ts;
5339 if (bbr->r_ctl.r_app_limited_until)
5340 rsm->r_app_limited = 1;
5341 else
5342 rsm->r_app_limited = 0;
5343 if (bbr->rc_bbr_state == BBR_STATE_PROBE_BW)
5344 rsm->r_bbr_state = bbr_state_val(bbr);
5345 else
5346 rsm->r_bbr_state = 8;
5347 if (rsm->r_flags & BBR_ACKED) {
5348 /* Problably MTU discovery messing with us */
5349 uint32_t old_flags;
5350
5351 old_flags = rsm->r_flags;
5352 rsm->r_flags &= ~BBR_ACKED;
5353 bbr_log_type_rsmclear(bbr, cts, rsm, old_flags, __LINE__);
5354 bbr->r_ctl.rc_sacked -= (rsm->r_end - rsm->r_start);
5355 if (bbr->r_ctl.rc_sacked == 0)
5356 bbr->r_ctl.rc_sacklast = NULL;
5357 }
5358 if (rsm->r_in_tmap) {
5359 TAILQ_REMOVE(&bbr->r_ctl.rc_tmap, rsm, r_tnext);
5360 }
5361 TAILQ_INSERT_TAIL(&bbr->r_ctl.rc_tmap, rsm, r_tnext);
5362 rsm->r_in_tmap = 1;
5363 if (rsm->r_flags & BBR_SACK_PASSED) {
5364 /* We have retransmitted due to the SACK pass */
5365 rsm->r_flags &= ~BBR_SACK_PASSED;
5366 rsm->r_flags |= BBR_WAS_SACKPASS;
5367 }
5368 rsm->r_first_sent_time = bbr_get_earliest_send_outstanding(bbr, rsm, cts);
5369 rsm->r_flight_at_send = ctf_flight_size(bbr->rc_tp,
5370 (bbr->r_ctl.rc_sacked + bbr->r_ctl.rc_lost_bytes));
5371 bbr->r_ctl.rc_next = TAILQ_NEXT(rsm, r_next);
5372 if (bbr->r_ctl.rc_bbr_hptsi_gain > BBR_UNIT) {
5373 rsm->r_is_gain = 1;
5374 rsm->r_is_drain = 0;
5375 } else if (bbr->r_ctl.rc_bbr_hptsi_gain < BBR_UNIT) {
5376 rsm->r_is_drain = 1;
5377 rsm->r_is_gain = 0;
5378 } else {
5379 rsm->r_is_drain = 0;
5380 rsm->r_is_gain = 0;
5381 }
5382 rsm->r_del_time = bbr->r_ctl.rc_del_time; /* TEMP GOOGLE CODE */
5383 }
5384
5385 /*
5386 * Returns 0, or the sequence where we stopped
5387 * updating. We also update the lenp to be the amount
5388 * of data left.
5389 */
5390
5391 static uint32_t
bbr_update_entry(struct tcpcb * tp,struct tcp_bbr * bbr,struct bbr_sendmap * rsm,uint32_t cts,int32_t * lenp,uint32_t pacing_time)5392 bbr_update_entry(struct tcpcb *tp, struct tcp_bbr *bbr,
5393 struct bbr_sendmap *rsm, uint32_t cts, int32_t *lenp, uint32_t pacing_time)
5394 {
5395 /*
5396 * We (re-)transmitted starting at rsm->r_start for some length
5397 * (possibly less than r_end.
5398 */
5399 struct bbr_sendmap *nrsm;
5400 uint32_t c_end;
5401 int32_t len;
5402
5403 len = *lenp;
5404 c_end = rsm->r_start + len;
5405 if (SEQ_GEQ(c_end, rsm->r_end)) {
5406 /*
5407 * We retransmitted the whole piece or more than the whole
5408 * slopping into the next rsm.
5409 */
5410 bbr_update_rsm(tp, bbr, rsm, cts, pacing_time);
5411 if (c_end == rsm->r_end) {
5412 *lenp = 0;
5413 return (0);
5414 } else {
5415 int32_t act_len;
5416
5417 /* Hangs over the end return whats left */
5418 act_len = rsm->r_end - rsm->r_start;
5419 *lenp = (len - act_len);
5420 return (rsm->r_end);
5421 }
5422 /* We don't get out of this block. */
5423 }
5424 /*
5425 * Here we retransmitted less than the whole thing which means we
5426 * have to split this into what was transmitted and what was not.
5427 */
5428 nrsm = bbr_alloc_full_limit(bbr);
5429 if (nrsm == NULL) {
5430 *lenp = 0;
5431 return (0);
5432 }
5433 /*
5434 * So here we are going to take the original rsm and make it what we
5435 * retransmitted. nrsm will be the tail portion we did not
5436 * retransmit. For example say the chunk was 1, 11 (10 bytes). And
5437 * we retransmitted 5 bytes i.e. 1, 5. The original piece shrinks to
5438 * 1, 6 and the new piece will be 6, 11.
5439 */
5440 bbr_clone_rsm(bbr, nrsm, rsm, c_end);
5441 TAILQ_INSERT_AFTER(&bbr->r_ctl.rc_map, rsm, nrsm, r_next);
5442 nrsm->r_dupack = 0;
5443 if (rsm->r_in_tmap) {
5444 TAILQ_INSERT_AFTER(&bbr->r_ctl.rc_tmap, rsm, nrsm, r_tnext);
5445 nrsm->r_in_tmap = 1;
5446 }
5447 rsm->r_flags &= (~BBR_HAS_FIN);
5448 bbr_update_rsm(tp, bbr, rsm, cts, pacing_time);
5449 *lenp = 0;
5450 return (0);
5451 }
5452
5453 static uint64_t
bbr_get_hardware_rate(struct tcp_bbr * bbr)5454 bbr_get_hardware_rate(struct tcp_bbr *bbr)
5455 {
5456 uint64_t bw;
5457
5458 bw = bbr_get_bw(bbr);
5459 bw *= (uint64_t)bbr_hptsi_gain[BBR_SUB_GAIN];
5460 bw /= (uint64_t)BBR_UNIT;
5461 return(bw);
5462 }
5463
5464 static void
bbr_setup_less_of_rate(struct tcp_bbr * bbr,uint32_t cts,uint64_t act_rate,uint64_t rate_wanted)5465 bbr_setup_less_of_rate(struct tcp_bbr *bbr, uint32_t cts,
5466 uint64_t act_rate, uint64_t rate_wanted)
5467 {
5468 /*
5469 * We could not get a full gains worth
5470 * of rate.
5471 */
5472 if (get_filter_value(&bbr->r_ctl.rc_delrate) >= act_rate) {
5473 /* we can't even get the real rate */
5474 uint64_t red;
5475
5476 bbr->skip_gain = 1;
5477 bbr->gain_is_limited = 0;
5478 red = get_filter_value(&bbr->r_ctl.rc_delrate) - act_rate;
5479 if (red)
5480 filter_reduce_by(&bbr->r_ctl.rc_delrate, red, cts);
5481 } else {
5482 /* We can use a lower gain */
5483 bbr->skip_gain = 0;
5484 bbr->gain_is_limited = 1;
5485 }
5486 }
5487
5488 static void
bbr_update_hardware_pacing_rate(struct tcp_bbr * bbr,uint32_t cts)5489 bbr_update_hardware_pacing_rate(struct tcp_bbr *bbr, uint32_t cts)
5490 {
5491 const struct tcp_hwrate_limit_table *nrte;
5492 int error, rate = -1;
5493
5494 if (bbr->r_ctl.crte == NULL)
5495 return;
5496 if ((bbr->rc_inp->inp_route.ro_nh == NULL) ||
5497 (bbr->rc_inp->inp_route.ro_nh->nh_ifp == NULL)) {
5498 /* Lost our routes? */
5499 /* Clear the way for a re-attempt */
5500 bbr->bbr_attempt_hdwr_pace = 0;
5501 lost_rate:
5502 bbr->gain_is_limited = 0;
5503 bbr->skip_gain = 0;
5504 bbr->bbr_hdrw_pacing = 0;
5505 counter_u64_add(bbr_flows_whdwr_pacing, -1);
5506 counter_u64_add(bbr_flows_nohdwr_pacing, 1);
5507 tcp_bbr_tso_size_check(bbr, cts);
5508 return;
5509 }
5510 rate = bbr_get_hardware_rate(bbr);
5511 nrte = tcp_chg_pacing_rate(bbr->r_ctl.crte,
5512 bbr->rc_tp,
5513 bbr->rc_inp->inp_route.ro_nh->nh_ifp,
5514 rate,
5515 (RS_PACING_GEQ|RS_PACING_SUB_OK),
5516 &error, NULL);
5517 if (nrte == NULL) {
5518 goto lost_rate;
5519 }
5520 if (nrte != bbr->r_ctl.crte) {
5521 bbr->r_ctl.crte = nrte;
5522 if (error == 0) {
5523 BBR_STAT_INC(bbr_hdwr_rl_mod_ok);
5524 if (bbr->r_ctl.crte->rate < rate) {
5525 /* We have a problem */
5526 bbr_setup_less_of_rate(bbr, cts,
5527 bbr->r_ctl.crte->rate, rate);
5528 } else {
5529 /* We are good */
5530 bbr->gain_is_limited = 0;
5531 bbr->skip_gain = 0;
5532 }
5533 } else {
5534 /* A failure should release the tag */
5535 BBR_STAT_INC(bbr_hdwr_rl_mod_fail);
5536 bbr->gain_is_limited = 0;
5537 bbr->skip_gain = 0;
5538 bbr->bbr_hdrw_pacing = 0;
5539 }
5540 bbr_type_log_hdwr_pacing(bbr,
5541 bbr->r_ctl.crte->ptbl->rs_ifp,
5542 rate,
5543 bbr->r_ctl.crte->rate,
5544 __LINE__,
5545 cts,
5546 error);
5547 }
5548 }
5549
5550 static void
bbr_adjust_for_hw_pacing(struct tcp_bbr * bbr,uint32_t cts)5551 bbr_adjust_for_hw_pacing(struct tcp_bbr *bbr, uint32_t cts)
5552 {
5553 /*
5554 * If we have hardware pacing support
5555 * we need to factor that in for our
5556 * TSO size.
5557 */
5558 const struct tcp_hwrate_limit_table *rlp;
5559 uint32_t cur_delay, seg_sz, maxseg, new_tso, delta, hdwr_delay;
5560
5561 if ((bbr->bbr_hdrw_pacing == 0) ||
5562 (IN_RECOVERY(bbr->rc_tp->t_flags)) ||
5563 (bbr->r_ctl.crte == NULL))
5564 return;
5565 if (bbr->hw_pacing_set == 0) {
5566 /* Not yet by the hdwr pacing count delay */
5567 return;
5568 }
5569 if (bbr_hdwr_pace_adjust == 0) {
5570 /* No adjustment */
5571 return;
5572 }
5573 rlp = bbr->r_ctl.crte;
5574 if (bbr->rc_tp->t_maxseg > bbr->rc_last_options)
5575 maxseg = bbr->rc_tp->t_maxseg - bbr->rc_last_options;
5576 else
5577 maxseg = BBR_MIN_SEG - bbr->rc_last_options;
5578 /*
5579 * So lets first get the
5580 * time we will take between
5581 * TSO sized sends currently without
5582 * hardware help.
5583 */
5584 cur_delay = bbr_get_pacing_delay(bbr, BBR_UNIT,
5585 bbr->r_ctl.rc_pace_max_segs, cts, 1);
5586 hdwr_delay = bbr->r_ctl.rc_pace_max_segs / maxseg;
5587 hdwr_delay *= rlp->time_between;
5588 if (cur_delay > hdwr_delay)
5589 delta = cur_delay - hdwr_delay;
5590 else
5591 delta = 0;
5592 bbr_log_type_tsosize(bbr, cts, delta, cur_delay, hdwr_delay,
5593 (bbr->r_ctl.rc_pace_max_segs / maxseg),
5594 1);
5595 if (delta &&
5596 (delta < (max(rlp->time_between,
5597 bbr->r_ctl.bbr_hptsi_segments_delay_tar)))) {
5598 /*
5599 * Now lets divide by the pacing
5600 * time between each segment the
5601 * hardware sends rounding up and
5602 * derive a bytes from that. We multiply
5603 * that by bbr_hdwr_pace_adjust to get
5604 * more bang for our buck.
5605 *
5606 * The goal is to have the software pacer
5607 * waiting no more than an additional
5608 * pacing delay if we can (without the
5609 * compensation i.e. x bbr_hdwr_pace_adjust).
5610 */
5611 seg_sz = max(((cur_delay + rlp->time_between)/rlp->time_between),
5612 (bbr->r_ctl.rc_pace_max_segs/maxseg));
5613 seg_sz *= bbr_hdwr_pace_adjust;
5614 if (bbr_hdwr_pace_floor &&
5615 (seg_sz < bbr->r_ctl.crte->ptbl->rs_min_seg)) {
5616 /* Currently hardware paces
5617 * out rs_min_seg segments at a time.
5618 * We need to make sure we always send at least
5619 * a full burst of bbr_hdwr_pace_floor down.
5620 */
5621 seg_sz = bbr->r_ctl.crte->ptbl->rs_min_seg;
5622 }
5623 seg_sz *= maxseg;
5624 } else if (delta == 0) {
5625 /*
5626 * The highest pacing rate is
5627 * above our b/w gained. This means
5628 * we probably are going quite fast at
5629 * the hardware highest rate. Lets just multiply
5630 * the calculated TSO size by the
5631 * multiplier factor (its probably
5632 * 4 segments in the default config for
5633 * mlx).
5634 */
5635 seg_sz = bbr->r_ctl.rc_pace_max_segs * bbr_hdwr_pace_adjust;
5636 if (bbr_hdwr_pace_floor &&
5637 (seg_sz < bbr->r_ctl.crte->ptbl->rs_min_seg)) {
5638 /* Currently hardware paces
5639 * out rs_min_seg segments at a time.
5640 * We need to make sure we always send at least
5641 * a full burst of bbr_hdwr_pace_floor down.
5642 */
5643 seg_sz = bbr->r_ctl.crte->ptbl->rs_min_seg;
5644 }
5645 } else {
5646 /*
5647 * The pacing time difference is so
5648 * big that the hardware will
5649 * pace out more rapidly then we
5650 * really want and then we
5651 * will have a long delay. Lets just keep
5652 * the same TSO size so its as if
5653 * we were not using hdwr pacing (we
5654 * just gain a bit of spacing from the
5655 * hardware if seg_sz > 1).
5656 */
5657 seg_sz = bbr->r_ctl.rc_pace_max_segs;
5658 }
5659 if (seg_sz > bbr->r_ctl.rc_pace_max_segs)
5660 new_tso = seg_sz;
5661 else
5662 new_tso = bbr->r_ctl.rc_pace_max_segs;
5663 if (new_tso >= (PACE_MAX_IP_BYTES-maxseg))
5664 new_tso = PACE_MAX_IP_BYTES - maxseg;
5665
5666 if (new_tso != bbr->r_ctl.rc_pace_max_segs) {
5667 bbr_log_type_tsosize(bbr, cts, new_tso, 0, bbr->r_ctl.rc_pace_max_segs, maxseg, 0);
5668 bbr->r_ctl.rc_pace_max_segs = new_tso;
5669 }
5670 }
5671
5672 static void
tcp_bbr_tso_size_check(struct tcp_bbr * bbr,uint32_t cts)5673 tcp_bbr_tso_size_check(struct tcp_bbr *bbr, uint32_t cts)
5674 {
5675 uint64_t bw;
5676 uint32_t old_tso = 0, new_tso;
5677 uint32_t maxseg, bytes;
5678 uint32_t tls_seg=0;
5679 /*
5680 * Google/linux uses the following algorithm to determine
5681 * the TSO size based on the b/w of the link (from Neal Cardwell email 9/27/18):
5682 *
5683 * bytes = bw_in_bytes_per_second / 1000
5684 * bytes = min(bytes, 64k)
5685 * tso_segs = bytes / MSS
5686 * if (bw < 1.2Mbs)
5687 * min_tso_segs = 1
5688 * else
5689 * min_tso_segs = 2
5690 * tso_segs = max(tso_segs, min_tso_segs)
5691 *
5692 * * Note apply a device specific limit (we apply this in the
5693 * tcp_m_copym).
5694 * Note that before the initial measurement is made google bursts out
5695 * a full iwnd just like new-reno/cubic.
5696 *
5697 * We do not use this algorithm. Instead we
5698 * use a two phased approach:
5699 *
5700 * if ( bw <= per-tcb-cross-over)
5701 * goal_tso = calculate how much with this bw we
5702 * can send in goal-time seconds.
5703 * if (goal_tso > mss)
5704 * seg = goal_tso / mss
5705 * tso = seg * mss
5706 * else
5707 * tso = mss
5708 * if (tso > per-tcb-max)
5709 * tso = per-tcb-max
5710 * else if ( bw > 512Mbps)
5711 * tso = max-tso (64k/mss)
5712 * else
5713 * goal_tso = bw / per-tcb-divsor
5714 * seg = (goal_tso + mss-1)/mss
5715 * tso = seg * mss
5716 *
5717 * if (tso < per-tcb-floor)
5718 * tso = per-tcb-floor
5719 * if (tso > per-tcb-utter_max)
5720 * tso = per-tcb-utter_max
5721 *
5722 * Note the default per-tcb-divisor is 1000 (same as google).
5723 * the goal cross over is 30Mbps however. To recreate googles
5724 * algorithm you need to set:
5725 *
5726 * cross-over = 23,168,000 bps
5727 * goal-time = 18000
5728 * per-tcb-max = 2
5729 * per-tcb-divisor = 1000
5730 * per-tcb-floor = 1
5731 *
5732 * This will get you "google bbr" behavior with respect to tso size.
5733 *
5734 * Note we do set anything TSO size until we are past the initial
5735 * window. Before that we gnerally use either a single MSS
5736 * or we use the full IW size (so we burst a IW at a time)
5737 */
5738
5739 if (bbr->rc_tp->t_maxseg > bbr->rc_last_options) {
5740 maxseg = bbr->rc_tp->t_maxseg - bbr->rc_last_options;
5741 } else {
5742 maxseg = BBR_MIN_SEG - bbr->rc_last_options;
5743 }
5744 old_tso = bbr->r_ctl.rc_pace_max_segs;
5745 if (bbr->rc_past_init_win == 0) {
5746 /*
5747 * Not enough data has been acknowledged to make a
5748 * judgement. Set up the initial TSO based on if we
5749 * are sending a full IW at once or not.
5750 */
5751 if (bbr->rc_use_google)
5752 bbr->r_ctl.rc_pace_max_segs = ((bbr->rc_tp->t_maxseg - bbr->rc_last_options) * 2);
5753 else if (bbr->bbr_init_win_cheat)
5754 bbr->r_ctl.rc_pace_max_segs = bbr_initial_cwnd(bbr, bbr->rc_tp);
5755 else
5756 bbr->r_ctl.rc_pace_max_segs = bbr->rc_tp->t_maxseg - bbr->rc_last_options;
5757 if (bbr->r_ctl.rc_pace_min_segs != bbr->rc_tp->t_maxseg)
5758 bbr->r_ctl.rc_pace_min_segs = bbr->rc_tp->t_maxseg;
5759 if (bbr->r_ctl.rc_pace_max_segs == 0) {
5760 bbr->r_ctl.rc_pace_max_segs = maxseg;
5761 }
5762 bbr_log_type_tsosize(bbr, cts, bbr->r_ctl.rc_pace_max_segs, tls_seg, old_tso, maxseg, 0);
5763 bbr_adjust_for_hw_pacing(bbr, cts);
5764 return;
5765 }
5766 /**
5767 * Now lets set the TSO goal based on our delivery rate in
5768 * bytes per second. Note we only do this if
5769 * we have acked at least the initial cwnd worth of data.
5770 */
5771 bw = bbr_get_bw(bbr);
5772 if (IN_RECOVERY(bbr->rc_tp->t_flags) &&
5773 (bbr->rc_use_google == 0)) {
5774 /* We clamp to one MSS in recovery */
5775 new_tso = maxseg;
5776 } else if (bbr->rc_use_google) {
5777 int min_tso_segs;
5778
5779 /* Google considers the gain too */
5780 if (bbr->r_ctl.rc_bbr_hptsi_gain != BBR_UNIT) {
5781 bw *= bbr->r_ctl.rc_bbr_hptsi_gain;
5782 bw /= BBR_UNIT;
5783 }
5784 bytes = bw / 1024;
5785 if (bytes > (64 * 1024))
5786 bytes = 64 * 1024;
5787 new_tso = bytes / maxseg;
5788 if (bw < ONE_POINT_TWO_MEG)
5789 min_tso_segs = 1;
5790 else
5791 min_tso_segs = 2;
5792 if (new_tso < min_tso_segs)
5793 new_tso = min_tso_segs;
5794 new_tso *= maxseg;
5795 } else if (bbr->rc_no_pacing) {
5796 new_tso = (PACE_MAX_IP_BYTES / maxseg) * maxseg;
5797 } else if (bw <= bbr->r_ctl.bbr_cross_over) {
5798 /*
5799 * Calculate the worse case b/w TSO if we are inserting no
5800 * more than a delay_target number of TSO's.
5801 */
5802 uint32_t tso_len, min_tso;
5803
5804 tso_len = bbr_get_pacing_length(bbr, BBR_UNIT, bbr->r_ctl.bbr_hptsi_segments_delay_tar, bw);
5805 if (tso_len > maxseg) {
5806 new_tso = tso_len / maxseg;
5807 if (new_tso > bbr->r_ctl.bbr_hptsi_segments_max)
5808 new_tso = bbr->r_ctl.bbr_hptsi_segments_max;
5809 new_tso *= maxseg;
5810 } else {
5811 /*
5812 * less than a full sized frame yikes.. long rtt or
5813 * low bw?
5814 */
5815 min_tso = bbr_minseg(bbr);
5816 if ((tso_len > min_tso) && (bbr_all_get_min == 0))
5817 new_tso = rounddown(tso_len, min_tso);
5818 else
5819 new_tso = min_tso;
5820 }
5821 } else if (bw > FIVETWELVE_MBPS) {
5822 /*
5823 * This guy is so fast b/w wise that we can TSO as large as
5824 * possible of segments that the NIC will allow.
5825 */
5826 new_tso = rounddown(PACE_MAX_IP_BYTES, maxseg);
5827 } else {
5828 /*
5829 * This formula is based on attempting to send a segment or
5830 * more every bbr_hptsi_per_second. The default is 1000
5831 * which means you are targeting what you can send every 1ms
5832 * based on the peers bw.
5833 *
5834 * If the number drops to say 500, then you are looking more
5835 * at 2ms and you will raise how much we send in a single
5836 * TSO thus saving CPU (less bbr_output_wtime() calls). The
5837 * trade off of course is you will send more at once and
5838 * thus tend to clump up the sends into larger "bursts"
5839 * building a queue.
5840 */
5841 bw /= bbr->r_ctl.bbr_hptsi_per_second;
5842 new_tso = roundup(bw, (uint64_t)maxseg);
5843 /*
5844 * Gate the floor to match what our lower than 48Mbps
5845 * algorithm does. The ceiling (bbr_hptsi_segments_max) thus
5846 * becomes the floor for this calculation.
5847 */
5848 if (new_tso < (bbr->r_ctl.bbr_hptsi_segments_max * maxseg))
5849 new_tso = (bbr->r_ctl.bbr_hptsi_segments_max * maxseg);
5850 }
5851 if (bbr->r_ctl.bbr_hptsi_segments_floor && (new_tso < (maxseg * bbr->r_ctl.bbr_hptsi_segments_floor)))
5852 new_tso = maxseg * bbr->r_ctl.bbr_hptsi_segments_floor;
5853 if (new_tso > PACE_MAX_IP_BYTES)
5854 new_tso = rounddown(PACE_MAX_IP_BYTES, maxseg);
5855 /* Enforce an utter maximum. */
5856 if (bbr->r_ctl.bbr_utter_max && (new_tso > (bbr->r_ctl.bbr_utter_max * maxseg))) {
5857 new_tso = bbr->r_ctl.bbr_utter_max * maxseg;
5858 }
5859 if (old_tso != new_tso) {
5860 /* Only log changes */
5861 bbr_log_type_tsosize(bbr, cts, new_tso, tls_seg, old_tso, maxseg, 0);
5862 bbr->r_ctl.rc_pace_max_segs = new_tso;
5863 }
5864 /* We have hardware pacing! */
5865 bbr_adjust_for_hw_pacing(bbr, cts);
5866 }
5867
5868 static void
bbr_log_output(struct tcp_bbr * bbr,struct tcpcb * tp,struct tcpopt * to,int32_t len,uint32_t seq_out,uint16_t th_flags,int32_t err,uint32_t cts,struct mbuf * mb,int32_t * abandon,struct bbr_sendmap * hintrsm,uint32_t delay_calc,struct sockbuf * sb)5869 bbr_log_output(struct tcp_bbr *bbr, struct tcpcb *tp, struct tcpopt *to, int32_t len,
5870 uint32_t seq_out, uint16_t th_flags, int32_t err, uint32_t cts,
5871 struct mbuf *mb, int32_t * abandon, struct bbr_sendmap *hintrsm, uint32_t delay_calc,
5872 struct sockbuf *sb)
5873 {
5874
5875 struct bbr_sendmap *rsm, *nrsm;
5876 register uint32_t snd_max, snd_una;
5877 uint32_t pacing_time;
5878 /*
5879 * Add to the RACK log of packets in flight or retransmitted. If
5880 * there is a TS option we will use the TS echoed, if not we will
5881 * grab a TS.
5882 *
5883 * Retransmissions will increment the count and move the ts to its
5884 * proper place. Note that if options do not include TS's then we
5885 * won't be able to effectively use the ACK for an RTT on a retran.
5886 *
5887 * Notes about r_start and r_end. Lets consider a send starting at
5888 * sequence 1 for 10 bytes. In such an example the r_start would be
5889 * 1 (starting sequence) but the r_end would be r_start+len i.e. 11.
5890 * This means that r_end is actually the first sequence for the next
5891 * slot (11).
5892 *
5893 */
5894 INP_WLOCK_ASSERT(tptoinpcb(tp));
5895 if (err) {
5896 /*
5897 * We don't log errors -- we could but snd_max does not
5898 * advance in this case either.
5899 */
5900 return;
5901 }
5902 if (th_flags & TH_RST) {
5903 /*
5904 * We don't log resets and we return immediately from
5905 * sending
5906 */
5907 *abandon = 1;
5908 return;
5909 }
5910 snd_una = tp->snd_una;
5911 if (th_flags & (TH_SYN | TH_FIN) && (hintrsm == NULL)) {
5912 /*
5913 * The call to bbr_log_output is made before bumping
5914 * snd_max. This means we can record one extra byte on a SYN
5915 * or FIN if seq_out is adding more on and a FIN is present
5916 * (and we are not resending).
5917 */
5918 if ((th_flags & TH_SYN) && (tp->iss == seq_out))
5919 len++;
5920 if (th_flags & TH_FIN)
5921 len++;
5922 }
5923 if (SEQ_LEQ((seq_out + len), snd_una)) {
5924 /* Are sending an old segment to induce an ack (keep-alive)? */
5925 return;
5926 }
5927 if (SEQ_LT(seq_out, snd_una)) {
5928 /* huh? should we panic? */
5929 uint32_t end;
5930
5931 end = seq_out + len;
5932 seq_out = snd_una;
5933 len = end - seq_out;
5934 }
5935 snd_max = tp->snd_max;
5936 if (len == 0) {
5937 /* We don't log zero window probes */
5938 return;
5939 }
5940 pacing_time = bbr_get_pacing_delay(bbr, bbr->r_ctl.rc_bbr_hptsi_gain, len, cts, 1);
5941 /* First question is it a retransmission? */
5942 if (seq_out == snd_max) {
5943 again:
5944 rsm = bbr_alloc(bbr);
5945 if (rsm == NULL) {
5946 return;
5947 }
5948 rsm->r_flags = 0;
5949 if (th_flags & TH_SYN)
5950 rsm->r_flags |= BBR_HAS_SYN;
5951 if (th_flags & TH_FIN)
5952 rsm->r_flags |= BBR_HAS_FIN;
5953 rsm->r_tim_lastsent[0] = cts;
5954 rsm->r_rtr_cnt = 1;
5955 rsm->r_rtr_bytes = 0;
5956 rsm->r_start = seq_out;
5957 rsm->r_end = rsm->r_start + len;
5958 rsm->r_dupack = 0;
5959 rsm->r_delivered = bbr->r_ctl.rc_delivered;
5960 rsm->r_pacing_delay = pacing_time;
5961 rsm->r_ts_valid = bbr->rc_ts_valid;
5962 if (bbr->rc_ts_valid)
5963 rsm->r_del_ack_ts = bbr->r_ctl.last_inbound_ts;
5964 rsm->r_del_time = bbr->r_ctl.rc_del_time;
5965 if (bbr->r_ctl.r_app_limited_until)
5966 rsm->r_app_limited = 1;
5967 else
5968 rsm->r_app_limited = 0;
5969 rsm->r_first_sent_time = bbr_get_earliest_send_outstanding(bbr, rsm, cts);
5970 rsm->r_flight_at_send = ctf_flight_size(bbr->rc_tp,
5971 (bbr->r_ctl.rc_sacked + bbr->r_ctl.rc_lost_bytes));
5972 /*
5973 * Here we must also add in this rsm since snd_max
5974 * is updated after we return from a new send.
5975 */
5976 rsm->r_flight_at_send += len;
5977 TAILQ_INSERT_TAIL(&bbr->r_ctl.rc_map, rsm, r_next);
5978 TAILQ_INSERT_TAIL(&bbr->r_ctl.rc_tmap, rsm, r_tnext);
5979 rsm->r_in_tmap = 1;
5980 if (bbr->rc_bbr_state == BBR_STATE_PROBE_BW)
5981 rsm->r_bbr_state = bbr_state_val(bbr);
5982 else
5983 rsm->r_bbr_state = 8;
5984 if (bbr->r_ctl.rc_bbr_hptsi_gain > BBR_UNIT) {
5985 rsm->r_is_gain = 1;
5986 rsm->r_is_drain = 0;
5987 } else if (bbr->r_ctl.rc_bbr_hptsi_gain < BBR_UNIT) {
5988 rsm->r_is_drain = 1;
5989 rsm->r_is_gain = 0;
5990 } else {
5991 rsm->r_is_drain = 0;
5992 rsm->r_is_gain = 0;
5993 }
5994 return;
5995 }
5996 /*
5997 * If we reach here its a retransmission and we need to find it.
5998 */
5999 more:
6000 if (hintrsm && (hintrsm->r_start == seq_out)) {
6001 rsm = hintrsm;
6002 hintrsm = NULL;
6003 } else if (bbr->r_ctl.rc_next) {
6004 /* We have a hint from a previous run */
6005 rsm = bbr->r_ctl.rc_next;
6006 } else {
6007 /* No hints sorry */
6008 rsm = NULL;
6009 }
6010 if ((rsm) && (rsm->r_start == seq_out)) {
6011 /*
6012 * We used rc_next or hintrsm to retransmit, hopefully the
6013 * likely case.
6014 */
6015 seq_out = bbr_update_entry(tp, bbr, rsm, cts, &len, pacing_time);
6016 if (len == 0) {
6017 return;
6018 } else {
6019 goto more;
6020 }
6021 }
6022 /* Ok it was not the last pointer go through it the hard way. */
6023 TAILQ_FOREACH(rsm, &bbr->r_ctl.rc_map, r_next) {
6024 if (rsm->r_start == seq_out) {
6025 seq_out = bbr_update_entry(tp, bbr, rsm, cts, &len, pacing_time);
6026 bbr->r_ctl.rc_next = TAILQ_NEXT(rsm, r_next);
6027 if (len == 0) {
6028 return;
6029 } else {
6030 continue;
6031 }
6032 }
6033 if (SEQ_GEQ(seq_out, rsm->r_start) && SEQ_LT(seq_out, rsm->r_end)) {
6034 /* Transmitted within this piece */
6035 /*
6036 * Ok we must split off the front and then let the
6037 * update do the rest
6038 */
6039 nrsm = bbr_alloc_full_limit(bbr);
6040 if (nrsm == NULL) {
6041 bbr_update_rsm(tp, bbr, rsm, cts, pacing_time);
6042 return;
6043 }
6044 /*
6045 * copy rsm to nrsm and then trim the front of rsm
6046 * to not include this part.
6047 */
6048 bbr_clone_rsm(bbr, nrsm, rsm, seq_out);
6049 TAILQ_INSERT_AFTER(&bbr->r_ctl.rc_map, rsm, nrsm, r_next);
6050 if (rsm->r_in_tmap) {
6051 TAILQ_INSERT_AFTER(&bbr->r_ctl.rc_tmap, rsm, nrsm, r_tnext);
6052 nrsm->r_in_tmap = 1;
6053 }
6054 rsm->r_flags &= (~BBR_HAS_FIN);
6055 seq_out = bbr_update_entry(tp, bbr, nrsm, cts, &len, pacing_time);
6056 if (len == 0) {
6057 return;
6058 }
6059 }
6060 }
6061 /*
6062 * Hmm not found in map did they retransmit both old and on into the
6063 * new?
6064 */
6065 if (seq_out == tp->snd_max) {
6066 goto again;
6067 } else if (SEQ_LT(seq_out, tp->snd_max)) {
6068 #ifdef BBR_INVARIANTS
6069 printf("seq_out:%u len:%d snd_una:%u snd_max:%u -- but rsm not found?\n",
6070 seq_out, len, tp->snd_una, tp->snd_max);
6071 printf("Starting Dump of all rack entries\n");
6072 TAILQ_FOREACH(rsm, &bbr->r_ctl.rc_map, r_next) {
6073 printf("rsm:%p start:%u end:%u\n",
6074 rsm, rsm->r_start, rsm->r_end);
6075 }
6076 printf("Dump complete\n");
6077 panic("seq_out not found rack:%p tp:%p",
6078 bbr, tp);
6079 #endif
6080 } else {
6081 #ifdef BBR_INVARIANTS
6082 /*
6083 * Hmm beyond sndmax? (only if we are using the new rtt-pack
6084 * flag)
6085 */
6086 panic("seq_out:%u(%d) is beyond snd_max:%u tp:%p",
6087 seq_out, len, tp->snd_max, tp);
6088 #endif
6089 }
6090 }
6091
6092 static void
bbr_collapse_rtt(struct tcpcb * tp,struct tcp_bbr * bbr,int32_t rtt)6093 bbr_collapse_rtt(struct tcpcb *tp, struct tcp_bbr *bbr, int32_t rtt)
6094 {
6095 /*
6096 * Collapse timeout back the cum-ack moved.
6097 */
6098 tp->t_rxtshift = 0;
6099 tp->t_softerror = 0;
6100 }
6101
6102 static void
tcp_bbr_xmit_timer(struct tcp_bbr * bbr,uint32_t rtt_usecs,uint32_t rsm_send_time,uint32_t r_start,uint32_t tsin)6103 tcp_bbr_xmit_timer(struct tcp_bbr *bbr, uint32_t rtt_usecs, uint32_t rsm_send_time, uint32_t r_start, uint32_t tsin)
6104 {
6105 bbr->rtt_valid = 1;
6106 bbr->r_ctl.cur_rtt = rtt_usecs;
6107 bbr->r_ctl.ts_in = tsin;
6108 if (rsm_send_time)
6109 bbr->r_ctl.cur_rtt_send_time = rsm_send_time;
6110 }
6111
6112 static void
bbr_make_timestamp_determination(struct tcp_bbr * bbr)6113 bbr_make_timestamp_determination(struct tcp_bbr *bbr)
6114 {
6115 /**
6116 * We have in our bbr control:
6117 * 1) The timestamp we started observing cum-acks (bbr->r_ctl.bbr_ts_check_tstmp).
6118 * 2) Our timestamp indicating when we sent that packet (bbr->r_ctl.rsm->bbr_ts_check_our_cts).
6119 * 3) The current timestamp that just came in (bbr->r_ctl.last_inbound_ts)
6120 * 4) The time that the packet that generated that ack was sent (bbr->r_ctl.cur_rtt_send_time)
6121 *
6122 * Now we can calculate the time between the sends by doing:
6123 *
6124 * delta = bbr->r_ctl.cur_rtt_send_time - bbr->r_ctl.bbr_ts_check_our_cts
6125 *
6126 * And the peer's time between receiving them by doing:
6127 *
6128 * peer_delta = bbr->r_ctl.last_inbound_ts - bbr->r_ctl.bbr_ts_check_tstmp
6129 *
6130 * We want to figure out if the timestamp values are in msec, 10msec or usec.
6131 * We also may find that we can't use the timestamps if say we see
6132 * that the peer_delta indicates that though we may have taken 10ms to
6133 * pace out the data, it only saw 1ms between the two packets. This would
6134 * indicate that somewhere on the path is a batching entity that is giving
6135 * out time-slices of the actual b/w. This would mean we could not use
6136 * reliably the peers timestamps.
6137 *
6138 * We expect delta > peer_delta initially. Until we figure out the
6139 * timestamp difference which we will store in bbr->r_ctl.bbr_peer_tsratio.
6140 * If we place 1000 there then its a ms vs our usec. If we place 10000 there
6141 * then its 10ms vs our usec. If the peer is running a usec clock we would
6142 * put a 1 there. If the value is faster then ours, we will disable the
6143 * use of timestamps (though we could revist this later if we find it to be not
6144 * just an isolated one or two flows)).
6145 *
6146 * To detect the batching middle boxes we will come up with our compensation and
6147 * if with it in place, we find the peer is drastically off (by some margin) in
6148 * the smaller direction, then we will assume the worst case and disable use of timestamps.
6149 *
6150 */
6151 uint64_t delta, peer_delta, delta_up;
6152
6153 delta = bbr->r_ctl.cur_rtt_send_time - bbr->r_ctl.bbr_ts_check_our_cts;
6154 if (delta < bbr_min_usec_delta) {
6155 /*
6156 * Have not seen a min amount of time
6157 * between our send times so we can
6158 * make a determination of the timestamp
6159 * yet.
6160 */
6161 return;
6162 }
6163 peer_delta = bbr->r_ctl.last_inbound_ts - bbr->r_ctl.bbr_ts_check_tstmp;
6164 if (peer_delta < bbr_min_peer_delta) {
6165 /*
6166 * We may have enough in the form of
6167 * our delta but the peers number
6168 * has not changed that much. It could
6169 * be its clock ratio is such that
6170 * we need more data (10ms tick) or
6171 * there may be other compression scenarios
6172 * going on. In any event we need the
6173 * spread to be larger.
6174 */
6175 return;
6176 }
6177 /* Ok lets first see which way our delta is going */
6178 if (peer_delta > delta) {
6179 /* Very unlikely, the peer without
6180 * compensation shows that it saw
6181 * the two sends arrive further apart
6182 * then we saw then in micro-seconds.
6183 */
6184 if (peer_delta < (delta + ((delta * (uint64_t)1000)/ (uint64_t)bbr_delta_percent))) {
6185 /* well it looks like the peer is a micro-second clock. */
6186 bbr->rc_ts_clock_set = 1;
6187 bbr->r_ctl.bbr_peer_tsratio = 1;
6188 } else {
6189 bbr->rc_ts_cant_be_used = 1;
6190 bbr->rc_ts_clock_set = 1;
6191 }
6192 return;
6193 }
6194 /* Ok we know that the peer_delta is smaller than our send distance */
6195 bbr->rc_ts_clock_set = 1;
6196 /* First question is it within the percentage that they are using usec time? */
6197 delta_up = (peer_delta * 1000) / (uint64_t)bbr_delta_percent;
6198 if ((peer_delta + delta_up) >= delta) {
6199 /* Its a usec clock */
6200 bbr->r_ctl.bbr_peer_tsratio = 1;
6201 bbr_log_tstmp_validation(bbr, peer_delta, delta);
6202 return;
6203 }
6204 /* Ok if not usec, what about 10usec (though unlikely)? */
6205 delta_up = (peer_delta * 1000 * 10) / (uint64_t)bbr_delta_percent;
6206 if (((peer_delta * 10) + delta_up) >= delta) {
6207 bbr->r_ctl.bbr_peer_tsratio = 10;
6208 bbr_log_tstmp_validation(bbr, peer_delta, delta);
6209 return;
6210 }
6211 /* And what about 100usec (though again unlikely)? */
6212 delta_up = (peer_delta * 1000 * 100) / (uint64_t)bbr_delta_percent;
6213 if (((peer_delta * 100) + delta_up) >= delta) {
6214 bbr->r_ctl.bbr_peer_tsratio = 100;
6215 bbr_log_tstmp_validation(bbr, peer_delta, delta);
6216 return;
6217 }
6218 /* And how about 1 msec (the most likely one)? */
6219 delta_up = (peer_delta * 1000 * 1000) / (uint64_t)bbr_delta_percent;
6220 if (((peer_delta * 1000) + delta_up) >= delta) {
6221 bbr->r_ctl.bbr_peer_tsratio = 1000;
6222 bbr_log_tstmp_validation(bbr, peer_delta, delta);
6223 return;
6224 }
6225 /* Ok if not msec could it be 10 msec? */
6226 delta_up = (peer_delta * 1000 * 10000) / (uint64_t)bbr_delta_percent;
6227 if (((peer_delta * 10000) + delta_up) >= delta) {
6228 bbr->r_ctl.bbr_peer_tsratio = 10000;
6229 return;
6230 }
6231 /* If we fall down here the clock tick so slowly we can't use it */
6232 bbr->rc_ts_cant_be_used = 1;
6233 bbr->r_ctl.bbr_peer_tsratio = 0;
6234 bbr_log_tstmp_validation(bbr, peer_delta, delta);
6235 }
6236
6237 /*
6238 * Collect new round-trip time estimate
6239 * and update averages and current timeout.
6240 */
6241 static void
tcp_bbr_xmit_timer_commit(struct tcp_bbr * bbr,struct tcpcb * tp,uint32_t cts)6242 tcp_bbr_xmit_timer_commit(struct tcp_bbr *bbr, struct tcpcb *tp, uint32_t cts)
6243 {
6244 int32_t delta;
6245 uint32_t rtt, tsin;
6246 int32_t rtt_ticks;
6247
6248 if (bbr->rtt_valid == 0)
6249 /* No valid sample */
6250 return;
6251
6252 rtt = bbr->r_ctl.cur_rtt;
6253 tsin = bbr->r_ctl.ts_in;
6254 if (bbr->rc_prtt_set_ts) {
6255 /*
6256 * We are to force feed the rttProp filter due
6257 * to an entry into PROBE_RTT. This assures
6258 * that the times are sync'd between when we
6259 * go into PROBE_RTT and the filter expiration.
6260 *
6261 * Google does not use a true filter, so they do
6262 * this implicitly since they only keep one value
6263 * and when they enter probe-rtt they update the
6264 * value to the newest rtt.
6265 */
6266 uint32_t rtt_prop;
6267
6268 bbr->rc_prtt_set_ts = 0;
6269 rtt_prop = get_filter_value_small(&bbr->r_ctl.rc_rttprop);
6270 if (rtt > rtt_prop)
6271 filter_increase_by_small(&bbr->r_ctl.rc_rttprop, (rtt - rtt_prop), cts);
6272 else
6273 apply_filter_min_small(&bbr->r_ctl.rc_rttprop, rtt, cts);
6274 }
6275 #ifdef STATS
6276 stats_voi_update_abs_u32(tp->t_stats, VOI_TCP_PATHRTT, imax(0, rtt));
6277 #endif
6278 if (bbr->rc_ack_was_delayed)
6279 rtt += bbr->r_ctl.rc_ack_hdwr_delay;
6280
6281 if (rtt < bbr->r_ctl.rc_lowest_rtt)
6282 bbr->r_ctl.rc_lowest_rtt = rtt;
6283 bbr_log_rtt_sample(bbr, rtt, tsin);
6284 if (bbr->r_init_rtt) {
6285 /*
6286 * The initial rtt is not-trusted, nuke it and lets get
6287 * our first valid measurement in.
6288 */
6289 bbr->r_init_rtt = 0;
6290 tp->t_srtt = 0;
6291 }
6292 if ((bbr->rc_ts_clock_set == 0) && bbr->rc_ts_valid) {
6293 /*
6294 * So we have not yet figured out
6295 * what the peers TSTMP value is
6296 * in (most likely ms). We need a
6297 * series of cum-ack's to determine
6298 * this reliably.
6299 */
6300 if (bbr->rc_ack_is_cumack) {
6301 if (bbr->rc_ts_data_set) {
6302 /* Lets attempt to determine the timestamp granularity. */
6303 bbr_make_timestamp_determination(bbr);
6304 } else {
6305 bbr->rc_ts_data_set = 1;
6306 bbr->r_ctl.bbr_ts_check_tstmp = bbr->r_ctl.last_inbound_ts;
6307 bbr->r_ctl.bbr_ts_check_our_cts = bbr->r_ctl.cur_rtt_send_time;
6308 }
6309 } else {
6310 /*
6311 * We have to have consecutive acks
6312 * reset any "filled" state to none.
6313 */
6314 bbr->rc_ts_data_set = 0;
6315 }
6316 }
6317 /* Round it up */
6318 rtt_ticks = USEC_2_TICKS((rtt + (USECS_IN_MSEC - 1)));
6319 if (tp->t_srtt != 0) {
6320 /*
6321 * srtt is stored as fixed point with 5 bits after the
6322 * binary point (i.e., scaled by 8). The following magic is
6323 * equivalent to the smoothing algorithm in rfc793 with an
6324 * alpha of .875 (srtt = rtt/8 + srtt*7/8 in fixed point).
6325 * Adjust rtt to origin 0.
6326 */
6327
6328 delta = ((rtt_ticks - 1) << TCP_DELTA_SHIFT)
6329 - (tp->t_srtt >> (TCP_RTT_SHIFT - TCP_DELTA_SHIFT));
6330
6331 tp->t_srtt += delta;
6332 if (tp->t_srtt <= 0)
6333 tp->t_srtt = 1;
6334
6335 /*
6336 * We accumulate a smoothed rtt variance (actually, a
6337 * smoothed mean difference), then set the retransmit timer
6338 * to smoothed rtt + 4 times the smoothed variance. rttvar
6339 * is stored as fixed point with 4 bits after the binary
6340 * point (scaled by 16). The following is equivalent to
6341 * rfc793 smoothing with an alpha of .75 (rttvar =
6342 * rttvar*3/4 + |delta| / 4). This replaces rfc793's
6343 * wired-in beta.
6344 */
6345 if (delta < 0)
6346 delta = -delta;
6347 delta -= tp->t_rttvar >> (TCP_RTTVAR_SHIFT - TCP_DELTA_SHIFT);
6348 tp->t_rttvar += delta;
6349 if (tp->t_rttvar <= 0)
6350 tp->t_rttvar = 1;
6351 } else {
6352 /*
6353 * No rtt measurement yet - use the unsmoothed rtt. Set the
6354 * variance to half the rtt (so our first retransmit happens
6355 * at 3*rtt).
6356 */
6357 tp->t_srtt = rtt_ticks << TCP_RTT_SHIFT;
6358 tp->t_rttvar = rtt_ticks << (TCP_RTTVAR_SHIFT - 1);
6359 }
6360 KMOD_TCPSTAT_INC(tcps_rttupdated);
6361 if (tp->t_rttupdated < UCHAR_MAX)
6362 tp->t_rttupdated++;
6363 #ifdef STATS
6364 stats_voi_update_abs_u32(tp->t_stats, VOI_TCP_RTT, imax(0, rtt_ticks));
6365 #endif
6366 /*
6367 * the retransmit should happen at rtt + 4 * rttvar. Because of the
6368 * way we do the smoothing, srtt and rttvar will each average +1/2
6369 * tick of bias. When we compute the retransmit timer, we want 1/2
6370 * tick of rounding and 1 extra tick because of +-1/2 tick
6371 * uncertainty in the firing of the timer. The bias will give us
6372 * exactly the 1.5 tick we need. But, because the bias is
6373 * statistical, we have to test that we don't drop below the minimum
6374 * feasible timer (which is 2 ticks).
6375 */
6376 TCPT_RANGESET(tp->t_rxtcur, TCP_REXMTVAL(tp),
6377 max(MSEC_2_TICKS(bbr->r_ctl.rc_min_rto_ms), rtt_ticks + 2),
6378 MSEC_2_TICKS(((uint32_t)bbr->rc_max_rto_sec) * 1000));
6379
6380 /*
6381 * We received an ack for a packet that wasn't retransmitted; it is
6382 * probably safe to discard any error indications we've received
6383 * recently. This isn't quite right, but close enough for now (a
6384 * route might have failed after we sent a segment, and the return
6385 * path might not be symmetrical).
6386 */
6387 tp->t_softerror = 0;
6388 rtt = (TICKS_2_USEC(bbr->rc_tp->t_srtt) >> TCP_RTT_SHIFT);
6389 if (bbr->r_ctl.bbr_smallest_srtt_this_state > rtt)
6390 bbr->r_ctl.bbr_smallest_srtt_this_state = rtt;
6391 }
6392
6393 static void
bbr_set_reduced_rtt(struct tcp_bbr * bbr,uint32_t cts,uint32_t line)6394 bbr_set_reduced_rtt(struct tcp_bbr *bbr, uint32_t cts, uint32_t line)
6395 {
6396 bbr->r_ctl.rc_rtt_shrinks = cts;
6397 if (bbr_can_force_probertt &&
6398 (TSTMP_GT(cts, bbr->r_ctl.last_in_probertt)) &&
6399 ((cts - bbr->r_ctl.last_in_probertt) > bbr->r_ctl.rc_probertt_int)) {
6400 /*
6401 * We should enter probe-rtt its been too long
6402 * since we have been there.
6403 */
6404 bbr_enter_probe_rtt(bbr, cts, __LINE__);
6405 } else
6406 bbr_check_probe_rtt_limits(bbr, cts);
6407 }
6408
6409 static void
tcp_bbr_commit_bw(struct tcp_bbr * bbr,uint32_t cts)6410 tcp_bbr_commit_bw(struct tcp_bbr *bbr, uint32_t cts)
6411 {
6412 uint64_t orig_bw;
6413
6414 if (bbr->r_ctl.rc_bbr_cur_del_rate == 0) {
6415 /* We never apply a zero measurement */
6416 bbr_log_type_bbrupd(bbr, 20, cts, 0, 0,
6417 0, 0, 0, 0, 0, 0);
6418 return;
6419 }
6420 if (bbr->r_ctl.r_measurement_count < 0xffffffff)
6421 bbr->r_ctl.r_measurement_count++;
6422 orig_bw = get_filter_value(&bbr->r_ctl.rc_delrate);
6423 apply_filter_max(&bbr->r_ctl.rc_delrate, bbr->r_ctl.rc_bbr_cur_del_rate, bbr->r_ctl.rc_pkt_epoch);
6424 bbr_log_type_bbrupd(bbr, 21, cts, (uint32_t)orig_bw,
6425 (uint32_t)get_filter_value(&bbr->r_ctl.rc_delrate),
6426 0, 0, 0, 0, 0, 0);
6427 if (orig_bw &&
6428 (orig_bw != get_filter_value(&bbr->r_ctl.rc_delrate))) {
6429 if (bbr->bbr_hdrw_pacing) {
6430 /*
6431 * Apply a new rate to the hardware
6432 * possibly.
6433 */
6434 bbr_update_hardware_pacing_rate(bbr, cts);
6435 }
6436 bbr_set_state_target(bbr, __LINE__);
6437 tcp_bbr_tso_size_check(bbr, cts);
6438 if (bbr->r_recovery_bw) {
6439 bbr_setup_red_bw(bbr, cts);
6440 bbr_log_type_bw_reduce(bbr, BBR_RED_BW_USELRBW);
6441 }
6442 } else if ((orig_bw == 0) && get_filter_value(&bbr->r_ctl.rc_delrate))
6443 tcp_bbr_tso_size_check(bbr, cts);
6444 }
6445
6446 static void
bbr_nf_measurement(struct tcp_bbr * bbr,struct bbr_sendmap * rsm,uint32_t rtt,uint32_t cts)6447 bbr_nf_measurement(struct tcp_bbr *bbr, struct bbr_sendmap *rsm, uint32_t rtt, uint32_t cts)
6448 {
6449 if (bbr->rc_in_persist == 0) {
6450 /* We log only when not in persist */
6451 /* Translate to a Bytes Per Second */
6452 uint64_t tim, bw, ts_diff, ts_bw;
6453 uint32_t delivered;
6454
6455 if (TSTMP_GT(bbr->r_ctl.rc_del_time, rsm->r_del_time))
6456 tim = (uint64_t)(bbr->r_ctl.rc_del_time - rsm->r_del_time);
6457 else
6458 tim = 1;
6459 /*
6460 * Now that we have processed the tim (skipping the sample
6461 * or possibly updating the time, go ahead and
6462 * calculate the cdr.
6463 */
6464 delivered = (bbr->r_ctl.rc_delivered - rsm->r_delivered);
6465 bw = (uint64_t)delivered;
6466 bw *= (uint64_t)USECS_IN_SECOND;
6467 bw /= tim;
6468 if (bw == 0) {
6469 /* We must have a calculatable amount */
6470 return;
6471 }
6472 /*
6473 * If we are using this b/w shove it in now so we
6474 * can see in the trace viewer if it gets over-ridden.
6475 */
6476 if (rsm->r_ts_valid &&
6477 bbr->rc_ts_valid &&
6478 bbr->rc_ts_clock_set &&
6479 (bbr->rc_ts_cant_be_used == 0) &&
6480 bbr->rc_use_ts_limit) {
6481 ts_diff = max((bbr->r_ctl.last_inbound_ts - rsm->r_del_ack_ts), 1);
6482 ts_diff *= bbr->r_ctl.bbr_peer_tsratio;
6483 if ((delivered == 0) ||
6484 (rtt < 1000)) {
6485 /* Can't use the ts */
6486 bbr_log_type_bbrupd(bbr, 61, cts,
6487 ts_diff,
6488 bbr->r_ctl.last_inbound_ts,
6489 rsm->r_del_ack_ts, 0,
6490 0, 0, 0, delivered);
6491 } else {
6492 ts_bw = (uint64_t)delivered;
6493 ts_bw *= (uint64_t)USECS_IN_SECOND;
6494 ts_bw /= ts_diff;
6495 bbr_log_type_bbrupd(bbr, 62, cts,
6496 (ts_bw >> 32),
6497 (ts_bw & 0xffffffff), 0, 0,
6498 0, 0, ts_diff, delivered);
6499 if ((bbr->ts_can_raise) &&
6500 (ts_bw > bw)) {
6501 bbr_log_type_bbrupd(bbr, 8, cts,
6502 delivered,
6503 ts_diff,
6504 (bw >> 32),
6505 (bw & 0x00000000ffffffff),
6506 0, 0, 0, 0);
6507 bw = ts_bw;
6508 } else if (ts_bw && (ts_bw < bw)) {
6509 bbr_log_type_bbrupd(bbr, 7, cts,
6510 delivered,
6511 ts_diff,
6512 (bw >> 32),
6513 (bw & 0x00000000ffffffff),
6514 0, 0, 0, 0);
6515 bw = ts_bw;
6516 }
6517 }
6518 }
6519 if (rsm->r_first_sent_time &&
6520 TSTMP_GT(rsm->r_tim_lastsent[(rsm->r_rtr_cnt -1)],rsm->r_first_sent_time)) {
6521 uint64_t sbw, sti;
6522 /*
6523 * We use what was in flight at the time of our
6524 * send and the size of this send to figure
6525 * out what we have been sending at (amount).
6526 * For the time we take from the time of
6527 * the send of the first send outstanding
6528 * until this send plus this sends pacing
6529 * time. This gives us a good calculation
6530 * as to the rate we have been sending at.
6531 */
6532
6533 sbw = (uint64_t)(rsm->r_flight_at_send);
6534 sbw *= (uint64_t)USECS_IN_SECOND;
6535 sti = rsm->r_tim_lastsent[(rsm->r_rtr_cnt -1)] - rsm->r_first_sent_time;
6536 sti += rsm->r_pacing_delay;
6537 sbw /= sti;
6538 if (sbw < bw) {
6539 bbr_log_type_bbrupd(bbr, 6, cts,
6540 delivered,
6541 (uint32_t)sti,
6542 (bw >> 32),
6543 (uint32_t)bw,
6544 rsm->r_first_sent_time, 0, (sbw >> 32),
6545 (uint32_t)sbw);
6546 bw = sbw;
6547 }
6548 }
6549 /* Use the google algorithm for b/w measurements */
6550 bbr->r_ctl.rc_bbr_cur_del_rate = bw;
6551 if ((rsm->r_app_limited == 0) ||
6552 (bw > get_filter_value(&bbr->r_ctl.rc_delrate))) {
6553 tcp_bbr_commit_bw(bbr, cts);
6554 bbr_log_type_bbrupd(bbr, 10, cts, (uint32_t)tim, delivered,
6555 0, 0, 0, 0, bbr->r_ctl.rc_del_time, rsm->r_del_time);
6556 }
6557 }
6558 }
6559
6560 static void
bbr_google_measurement(struct tcp_bbr * bbr,struct bbr_sendmap * rsm,uint32_t rtt,uint32_t cts)6561 bbr_google_measurement(struct tcp_bbr *bbr, struct bbr_sendmap *rsm, uint32_t rtt, uint32_t cts)
6562 {
6563 if (bbr->rc_in_persist == 0) {
6564 /* We log only when not in persist */
6565 /* Translate to a Bytes Per Second */
6566 uint64_t tim, bw;
6567 uint32_t delivered;
6568 int no_apply = 0;
6569
6570 if (TSTMP_GT(bbr->r_ctl.rc_del_time, rsm->r_del_time))
6571 tim = (uint64_t)(bbr->r_ctl.rc_del_time - rsm->r_del_time);
6572 else
6573 tim = 1;
6574 /*
6575 * Now that we have processed the tim (skipping the sample
6576 * or possibly updating the time, go ahead and
6577 * calculate the cdr.
6578 */
6579 delivered = (bbr->r_ctl.rc_delivered - rsm->r_delivered);
6580 bw = (uint64_t)delivered;
6581 bw *= (uint64_t)USECS_IN_SECOND;
6582 bw /= tim;
6583 if (tim < bbr->r_ctl.rc_lowest_rtt) {
6584 bbr_log_type_bbrupd(bbr, 99, cts, (uint32_t)tim, delivered,
6585 tim, bbr->r_ctl.rc_lowest_rtt, 0, 0, 0, 0);
6586
6587 no_apply = 1;
6588 }
6589 /*
6590 * If we are using this b/w shove it in now so we
6591 * can see in the trace viewer if it gets over-ridden.
6592 */
6593 bbr->r_ctl.rc_bbr_cur_del_rate = bw;
6594 /* Gate by the sending rate */
6595 if (rsm->r_first_sent_time &&
6596 TSTMP_GT(rsm->r_tim_lastsent[(rsm->r_rtr_cnt -1)],rsm->r_first_sent_time)) {
6597 uint64_t sbw, sti;
6598 /*
6599 * We use what was in flight at the time of our
6600 * send and the size of this send to figure
6601 * out what we have been sending at (amount).
6602 * For the time we take from the time of
6603 * the send of the first send outstanding
6604 * until this send plus this sends pacing
6605 * time. This gives us a good calculation
6606 * as to the rate we have been sending at.
6607 */
6608
6609 sbw = (uint64_t)(rsm->r_flight_at_send);
6610 sbw *= (uint64_t)USECS_IN_SECOND;
6611 sti = rsm->r_tim_lastsent[(rsm->r_rtr_cnt -1)] - rsm->r_first_sent_time;
6612 sti += rsm->r_pacing_delay;
6613 sbw /= sti;
6614 if (sbw < bw) {
6615 bbr_log_type_bbrupd(bbr, 6, cts,
6616 delivered,
6617 (uint32_t)sti,
6618 (bw >> 32),
6619 (uint32_t)bw,
6620 rsm->r_first_sent_time, 0, (sbw >> 32),
6621 (uint32_t)sbw);
6622 bw = sbw;
6623 }
6624 if ((sti > tim) &&
6625 (sti < bbr->r_ctl.rc_lowest_rtt)) {
6626 bbr_log_type_bbrupd(bbr, 99, cts, (uint32_t)tim, delivered,
6627 (uint32_t)sti, bbr->r_ctl.rc_lowest_rtt, 0, 0, 0, 0);
6628 no_apply = 1;
6629 } else
6630 no_apply = 0;
6631 }
6632 bbr->r_ctl.rc_bbr_cur_del_rate = bw;
6633 if ((no_apply == 0) &&
6634 ((rsm->r_app_limited == 0) ||
6635 (bw > get_filter_value(&bbr->r_ctl.rc_delrate)))) {
6636 tcp_bbr_commit_bw(bbr, cts);
6637 bbr_log_type_bbrupd(bbr, 10, cts, (uint32_t)tim, delivered,
6638 0, 0, 0, 0, bbr->r_ctl.rc_del_time, rsm->r_del_time);
6639 }
6640 }
6641 }
6642
6643 static void
bbr_update_bbr_info(struct tcp_bbr * bbr,struct bbr_sendmap * rsm,uint32_t rtt,uint32_t cts,uint32_t tsin,uint32_t uts,int32_t match,uint32_t rsm_send_time,int32_t ack_type,struct tcpopt * to)6644 bbr_update_bbr_info(struct tcp_bbr *bbr, struct bbr_sendmap *rsm, uint32_t rtt, uint32_t cts, uint32_t tsin,
6645 uint32_t uts, int32_t match, uint32_t rsm_send_time, int32_t ack_type, struct tcpopt *to)
6646 {
6647 uint64_t old_rttprop;
6648
6649 /* Update our delivery time and amount */
6650 bbr->r_ctl.rc_delivered += (rsm->r_end - rsm->r_start);
6651 bbr->r_ctl.rc_del_time = cts;
6652 if (rtt == 0) {
6653 /*
6654 * 0 means its a retransmit, for now we don't use these for
6655 * the rest of BBR.
6656 */
6657 return;
6658 }
6659 if ((bbr->rc_use_google == 0) &&
6660 (match != BBR_RTT_BY_EXACTMATCH) &&
6661 (match != BBR_RTT_BY_TIMESTAMP)){
6662 /*
6663 * We get a lot of rtt updates, lets not pay attention to
6664 * any that are not an exact match. That way we don't have
6665 * to worry about timestamps and the whole nonsense of
6666 * unsure if its a retransmission etc (if we ever had the
6667 * timestamp fixed to always have the last thing sent this
6668 * would not be a issue).
6669 */
6670 return;
6671 }
6672 if ((bbr_no_retran && bbr->rc_use_google) &&
6673 (match != BBR_RTT_BY_EXACTMATCH) &&
6674 (match != BBR_RTT_BY_TIMESTAMP)){
6675 /*
6676 * We only do measurements in google mode
6677 * with bbr_no_retran on for sure things.
6678 */
6679 return;
6680 }
6681 /* Only update srtt if we know by exact match */
6682 tcp_bbr_xmit_timer(bbr, rtt, rsm_send_time, rsm->r_start, tsin);
6683 if (ack_type == BBR_CUM_ACKED)
6684 bbr->rc_ack_is_cumack = 1;
6685 else
6686 bbr->rc_ack_is_cumack = 0;
6687 old_rttprop = bbr_get_rtt(bbr, BBR_RTT_PROP);
6688 /*
6689 * Note the following code differs to the original
6690 * BBR spec. It calls for <= not <. However after a
6691 * long discussion in email with Neal, he acknowledged
6692 * that it should be < than so that we will have flows
6693 * going into probe-rtt (we were seeing cases where that
6694 * did not happen and caused ugly things to occur). We
6695 * have added this agreed upon fix to our code base.
6696 */
6697 if (rtt < old_rttprop) {
6698 /* Update when we last saw a rtt drop */
6699 bbr_log_rtt_shrinks(bbr, cts, 0, rtt, __LINE__, BBR_RTTS_NEWRTT, 0);
6700 bbr_set_reduced_rtt(bbr, cts, __LINE__);
6701 }
6702 bbr_log_type_bbrrttprop(bbr, rtt, rsm->r_end, uts, cts,
6703 match, rsm->r_start, rsm->r_flags);
6704 apply_filter_min_small(&bbr->r_ctl.rc_rttprop, rtt, cts);
6705 if (old_rttprop != bbr_get_rtt(bbr, BBR_RTT_PROP)) {
6706 /*
6707 * The RTT-prop moved, reset the target (may be a
6708 * nop for some states).
6709 */
6710 bbr_set_state_target(bbr, __LINE__);
6711 if (bbr->rc_bbr_state == BBR_STATE_PROBE_RTT)
6712 bbr_log_rtt_shrinks(bbr, cts, 0, 0,
6713 __LINE__, BBR_RTTS_NEW_TARGET, 0);
6714 else if (old_rttprop < bbr_get_rtt(bbr, BBR_RTT_PROP))
6715 /* It went up */
6716 bbr_check_probe_rtt_limits(bbr, cts);
6717 }
6718 if ((bbr->rc_use_google == 0) &&
6719 (match == BBR_RTT_BY_TIMESTAMP)) {
6720 /*
6721 * We don't do b/w update with
6722 * these since they are not really
6723 * reliable.
6724 */
6725 return;
6726 }
6727 if (bbr->r_ctl.r_app_limited_until &&
6728 (bbr->r_ctl.rc_delivered >= bbr->r_ctl.r_app_limited_until)) {
6729 /* We are no longer app-limited */
6730 bbr->r_ctl.r_app_limited_until = 0;
6731 }
6732 if (bbr->rc_use_google) {
6733 bbr_google_measurement(bbr, rsm, rtt, cts);
6734 } else {
6735 bbr_nf_measurement(bbr, rsm, rtt, cts);
6736 }
6737 }
6738
6739 /*
6740 * Convert a timestamp that the main stack
6741 * uses (milliseconds) into one that bbr uses
6742 * (microseconds). Return that converted timestamp.
6743 */
6744 static uint32_t
bbr_ts_convert(uint32_t cts)6745 bbr_ts_convert(uint32_t cts) {
6746 uint32_t sec, msec;
6747
6748 sec = cts / MS_IN_USEC;
6749 msec = cts - (MS_IN_USEC * sec);
6750 return ((sec * USECS_IN_SECOND) + (msec * MS_IN_USEC));
6751 }
6752
6753 /*
6754 * Return 0 if we did not update the RTT time, return
6755 * 1 if we did.
6756 */
6757 static int
bbr_update_rtt(struct tcpcb * tp,struct tcp_bbr * bbr,struct bbr_sendmap * rsm,struct tcpopt * to,uint32_t cts,int32_t ack_type,uint32_t th_ack)6758 bbr_update_rtt(struct tcpcb *tp, struct tcp_bbr *bbr,
6759 struct bbr_sendmap *rsm, struct tcpopt *to, uint32_t cts, int32_t ack_type, uint32_t th_ack)
6760 {
6761 int32_t i;
6762 uint32_t t, uts = 0;
6763
6764 if ((rsm->r_flags & BBR_ACKED) ||
6765 (rsm->r_flags & BBR_WAS_RENEGED) ||
6766 (rsm->r_flags & BBR_RXT_CLEARED)) {
6767 /* Already done */
6768 return (0);
6769 }
6770 if (rsm->r_rtt_not_allowed) {
6771 /* Not allowed */
6772 return (0);
6773 }
6774 if (rsm->r_rtr_cnt == 1) {
6775 /*
6776 * Only one transmit. Hopefully the normal case.
6777 */
6778 if (TSTMP_GT(cts, rsm->r_tim_lastsent[0]))
6779 t = cts - rsm->r_tim_lastsent[0];
6780 else
6781 t = 1;
6782 bbr->r_ctl.rc_last_rtt = t;
6783 bbr_update_bbr_info(bbr, rsm, t, cts, to->to_tsecr, 0,
6784 BBR_RTT_BY_EXACTMATCH, rsm->r_tim_lastsent[0], ack_type, to);
6785 return (1);
6786 }
6787 /* Convert to usecs */
6788 if ((bbr_can_use_ts_for_rtt == 1) &&
6789 (bbr->rc_use_google == 1) &&
6790 (ack_type == BBR_CUM_ACKED) &&
6791 (to->to_flags & TOF_TS) &&
6792 (to->to_tsecr != 0)) {
6793 t = tcp_tv_to_msec(&bbr->rc_tv) - to->to_tsecr;
6794 if (t < 1)
6795 t = 1;
6796 t *= MS_IN_USEC;
6797 bbr_update_bbr_info(bbr, rsm, t, cts, to->to_tsecr, 0,
6798 BBR_RTT_BY_TIMESTAMP,
6799 rsm->r_tim_lastsent[(rsm->r_rtr_cnt-1)],
6800 ack_type, to);
6801 return (1);
6802 }
6803 uts = bbr_ts_convert(to->to_tsecr);
6804 if ((to->to_flags & TOF_TS) &&
6805 (to->to_tsecr != 0) &&
6806 (ack_type == BBR_CUM_ACKED) &&
6807 ((rsm->r_flags & BBR_OVERMAX) == 0)) {
6808 /*
6809 * Now which timestamp does it match? In this block the ACK
6810 * may be coming from a previous transmission.
6811 */
6812 uint32_t fudge;
6813
6814 fudge = BBR_TIMER_FUDGE;
6815 for (i = 0; i < rsm->r_rtr_cnt; i++) {
6816 if ((SEQ_GEQ(uts, (rsm->r_tim_lastsent[i] - fudge))) &&
6817 (SEQ_LEQ(uts, (rsm->r_tim_lastsent[i] + fudge)))) {
6818 if (TSTMP_GT(cts, rsm->r_tim_lastsent[i]))
6819 t = cts - rsm->r_tim_lastsent[i];
6820 else
6821 t = 1;
6822 bbr->r_ctl.rc_last_rtt = t;
6823 bbr_update_bbr_info(bbr, rsm, t, cts, to->to_tsecr, uts, BBR_RTT_BY_TSMATCHING,
6824 rsm->r_tim_lastsent[i], ack_type, to);
6825 if ((i + 1) < rsm->r_rtr_cnt) {
6826 /* Likely */
6827 return (0);
6828 } else if (rsm->r_flags & BBR_TLP) {
6829 bbr->rc_tlp_rtx_out = 0;
6830 }
6831 return (1);
6832 }
6833 }
6834 /* Fall through if we can't find a matching timestamp */
6835 }
6836 /*
6837 * Ok its a SACK block that we retransmitted. or a windows
6838 * machine without timestamps. We can tell nothing from the
6839 * time-stamp since its not there or the time the peer last
6840 * received a segment that moved forward its cum-ack point.
6841 *
6842 * Lets look at the last retransmit and see what we can tell
6843 * (with BBR for space we only keep 2 note we have to keep
6844 * at least 2 so the map can not be condensed more).
6845 */
6846 i = rsm->r_rtr_cnt - 1;
6847 if (TSTMP_GT(cts, rsm->r_tim_lastsent[i]))
6848 t = cts - rsm->r_tim_lastsent[i];
6849 else
6850 goto not_sure;
6851 if (t < bbr->r_ctl.rc_lowest_rtt) {
6852 /*
6853 * We retransmitted and the ack came back in less
6854 * than the smallest rtt we have observed in the
6855 * windowed rtt. We most likey did an improper
6856 * retransmit as outlined in 4.2 Step 3 point 2 in
6857 * the rack-draft.
6858 *
6859 * Use the prior transmission to update all the
6860 * information as long as there is only one prior
6861 * transmission.
6862 */
6863 if ((rsm->r_flags & BBR_OVERMAX) == 0) {
6864 #ifdef BBR_INVARIANTS
6865 if (rsm->r_rtr_cnt == 1)
6866 panic("rsm:%p bbr:%p rsm has overmax and only 1 retranmit flags:%x?", rsm, bbr, rsm->r_flags);
6867 #endif
6868 i = rsm->r_rtr_cnt - 2;
6869 if (TSTMP_GT(cts, rsm->r_tim_lastsent[i]))
6870 t = cts - rsm->r_tim_lastsent[i];
6871 else
6872 t = 1;
6873 bbr_update_bbr_info(bbr, rsm, t, cts, to->to_tsecr, uts, BBR_RTT_BY_EARLIER_RET,
6874 rsm->r_tim_lastsent[i], ack_type, to);
6875 return (0);
6876 } else {
6877 /*
6878 * Too many prior transmissions, just
6879 * updated BBR delivered
6880 */
6881 not_sure:
6882 bbr_update_bbr_info(bbr, rsm, 0, cts, to->to_tsecr, uts,
6883 BBR_RTT_BY_SOME_RETRAN, 0, ack_type, to);
6884 }
6885 } else {
6886 /*
6887 * We retransmitted it and the retransmit did the
6888 * job.
6889 */
6890 if (rsm->r_flags & BBR_TLP)
6891 bbr->rc_tlp_rtx_out = 0;
6892 if ((rsm->r_flags & BBR_OVERMAX) == 0)
6893 bbr_update_bbr_info(bbr, rsm, t, cts, to->to_tsecr, uts,
6894 BBR_RTT_BY_THIS_RETRAN, 0, ack_type, to);
6895 else
6896 bbr_update_bbr_info(bbr, rsm, 0, cts, to->to_tsecr, uts,
6897 BBR_RTT_BY_SOME_RETRAN, 0, ack_type, to);
6898 return (1);
6899 }
6900 return (0);
6901 }
6902
6903 /*
6904 * Mark the SACK_PASSED flag on all entries prior to rsm send wise.
6905 */
6906 static void
bbr_log_sack_passed(struct tcpcb * tp,struct tcp_bbr * bbr,struct bbr_sendmap * rsm)6907 bbr_log_sack_passed(struct tcpcb *tp,
6908 struct tcp_bbr *bbr, struct bbr_sendmap *rsm)
6909 {
6910 struct bbr_sendmap *nrsm;
6911
6912 nrsm = rsm;
6913 TAILQ_FOREACH_REVERSE_FROM(nrsm, &bbr->r_ctl.rc_tmap,
6914 bbr_head, r_tnext) {
6915 if (nrsm == rsm) {
6916 /* Skip original segment he is acked */
6917 continue;
6918 }
6919 if (nrsm->r_flags & BBR_ACKED) {
6920 /* Skip ack'd segments */
6921 continue;
6922 }
6923 if (nrsm->r_flags & BBR_SACK_PASSED) {
6924 /*
6925 * We found one that is already marked
6926 * passed, we have been here before and
6927 * so all others below this are marked.
6928 */
6929 break;
6930 }
6931 BBR_STAT_INC(bbr_sack_passed);
6932 nrsm->r_flags |= BBR_SACK_PASSED;
6933 if (((nrsm->r_flags & BBR_MARKED_LOST) == 0) &&
6934 bbr_is_lost(bbr, nrsm, bbr->r_ctl.rc_rcvtime)) {
6935 bbr->r_ctl.rc_lost += nrsm->r_end - nrsm->r_start;
6936 bbr->r_ctl.rc_lost_bytes += nrsm->r_end - nrsm->r_start;
6937 nrsm->r_flags |= BBR_MARKED_LOST;
6938 }
6939 nrsm->r_flags &= ~BBR_WAS_SACKPASS;
6940 }
6941 }
6942
6943 /*
6944 * Returns the number of bytes that were
6945 * newly ack'd by sack blocks.
6946 */
6947 static uint32_t
bbr_proc_sack_blk(struct tcpcb * tp,struct tcp_bbr * bbr,struct sackblk * sack,struct tcpopt * to,struct bbr_sendmap ** prsm,uint32_t cts)6948 bbr_proc_sack_blk(struct tcpcb *tp, struct tcp_bbr *bbr, struct sackblk *sack,
6949 struct tcpopt *to, struct bbr_sendmap **prsm, uint32_t cts)
6950 {
6951 int32_t times = 0;
6952 uint32_t start, end, changed = 0;
6953 struct bbr_sendmap *rsm, *nrsm;
6954 int32_t used_ref = 1;
6955 uint8_t went_back = 0, went_fwd = 0;
6956
6957 start = sack->start;
6958 end = sack->end;
6959 rsm = *prsm;
6960 if (rsm == NULL)
6961 used_ref = 0;
6962
6963 /* Do we locate the block behind where we last were? */
6964 if (rsm && SEQ_LT(start, rsm->r_start)) {
6965 went_back = 1;
6966 TAILQ_FOREACH_REVERSE_FROM(rsm, &bbr->r_ctl.rc_map, bbr_head, r_next) {
6967 if (SEQ_GEQ(start, rsm->r_start) &&
6968 SEQ_LT(start, rsm->r_end)) {
6969 goto do_rest_ofb;
6970 }
6971 }
6972 }
6973 start_at_beginning:
6974 went_fwd = 1;
6975 /*
6976 * Ok lets locate the block where this guy is fwd from rsm (if its
6977 * set)
6978 */
6979 TAILQ_FOREACH_FROM(rsm, &bbr->r_ctl.rc_map, r_next) {
6980 if (SEQ_GEQ(start, rsm->r_start) &&
6981 SEQ_LT(start, rsm->r_end)) {
6982 break;
6983 }
6984 }
6985 do_rest_ofb:
6986 if (rsm == NULL) {
6987 /*
6988 * This happens when we get duplicate sack blocks with the
6989 * same end. For example SACK 4: 100 SACK 3: 100 The sort
6990 * will not change there location so we would just start at
6991 * the end of the first one and get lost.
6992 */
6993 if (tp->t_flags & TF_SENTFIN) {
6994 /*
6995 * Check to see if we have not logged the FIN that
6996 * went out.
6997 */
6998 nrsm = TAILQ_LAST_FAST(&bbr->r_ctl.rc_map, bbr_sendmap, r_next);
6999 if (nrsm && (nrsm->r_end + 1) == tp->snd_max) {
7000 /*
7001 * Ok we did not get the FIN logged.
7002 */
7003 nrsm->r_end++;
7004 rsm = nrsm;
7005 goto do_rest_ofb;
7006 }
7007 }
7008 if (times == 1) {
7009 #ifdef BBR_INVARIANTS
7010 panic("tp:%p bbr:%p sack:%p to:%p prsm:%p",
7011 tp, bbr, sack, to, prsm);
7012 #else
7013 goto out;
7014 #endif
7015 }
7016 times++;
7017 BBR_STAT_INC(bbr_sack_proc_restart);
7018 rsm = NULL;
7019 goto start_at_beginning;
7020 }
7021 /* Ok we have an ACK for some piece of rsm */
7022 if (rsm->r_start != start) {
7023 /*
7024 * Need to split this in two pieces the before and after.
7025 */
7026 if (bbr_sack_mergable(rsm, start, end))
7027 nrsm = bbr_alloc_full_limit(bbr);
7028 else
7029 nrsm = bbr_alloc_limit(bbr, BBR_LIMIT_TYPE_SPLIT);
7030 if (nrsm == NULL) {
7031 /* We could not allocate ignore the sack */
7032 struct sackblk blk;
7033
7034 blk.start = start;
7035 blk.end = end;
7036 sack_filter_reject(&bbr->r_ctl.bbr_sf, &blk);
7037 goto out;
7038 }
7039 bbr_clone_rsm(bbr, nrsm, rsm, start);
7040 TAILQ_INSERT_AFTER(&bbr->r_ctl.rc_map, rsm, nrsm, r_next);
7041 if (rsm->r_in_tmap) {
7042 TAILQ_INSERT_AFTER(&bbr->r_ctl.rc_tmap, rsm, nrsm, r_tnext);
7043 nrsm->r_in_tmap = 1;
7044 }
7045 rsm->r_flags &= (~BBR_HAS_FIN);
7046 rsm = nrsm;
7047 }
7048 if (SEQ_GEQ(end, rsm->r_end)) {
7049 /*
7050 * The end of this block is either beyond this guy or right
7051 * at this guy.
7052 */
7053 if ((rsm->r_flags & BBR_ACKED) == 0) {
7054 bbr_update_rtt(tp, bbr, rsm, to, cts, BBR_SACKED, 0);
7055 changed += (rsm->r_end - rsm->r_start);
7056 bbr->r_ctl.rc_sacked += (rsm->r_end - rsm->r_start);
7057 bbr_log_sack_passed(tp, bbr, rsm);
7058 if (rsm->r_flags & BBR_MARKED_LOST) {
7059 bbr->r_ctl.rc_lost_bytes -= rsm->r_end - rsm->r_start;
7060 }
7061 /* Is Reordering occuring? */
7062 if (rsm->r_flags & BBR_SACK_PASSED) {
7063 BBR_STAT_INC(bbr_reorder_seen);
7064 bbr->r_ctl.rc_reorder_ts = cts;
7065 if (rsm->r_flags & BBR_MARKED_LOST) {
7066 bbr->r_ctl.rc_lost -= rsm->r_end - rsm->r_start;
7067 if (SEQ_GT(bbr->r_ctl.rc_lt_lost, bbr->r_ctl.rc_lost))
7068 /* LT sampling also needs adjustment */
7069 bbr->r_ctl.rc_lt_lost = bbr->r_ctl.rc_lost;
7070 }
7071 }
7072 rsm->r_flags |= BBR_ACKED;
7073 rsm->r_flags &= ~(BBR_TLP|BBR_WAS_RENEGED|BBR_RXT_CLEARED|BBR_MARKED_LOST);
7074 if (rsm->r_in_tmap) {
7075 TAILQ_REMOVE(&bbr->r_ctl.rc_tmap, rsm, r_tnext);
7076 rsm->r_in_tmap = 0;
7077 }
7078 }
7079 bbr_isit_a_pkt_epoch(bbr, cts, rsm, __LINE__, BBR_SACKED);
7080 if (end == rsm->r_end) {
7081 /* This block only - done */
7082 goto out;
7083 }
7084 /* There is more not coverend by this rsm move on */
7085 start = rsm->r_end;
7086 nrsm = TAILQ_NEXT(rsm, r_next);
7087 rsm = nrsm;
7088 times = 0;
7089 goto do_rest_ofb;
7090 }
7091 if (rsm->r_flags & BBR_ACKED) {
7092 /* Been here done that */
7093 goto out;
7094 }
7095 /* Ok we need to split off this one at the tail */
7096 if (bbr_sack_mergable(rsm, start, end))
7097 nrsm = bbr_alloc_full_limit(bbr);
7098 else
7099 nrsm = bbr_alloc_limit(bbr, BBR_LIMIT_TYPE_SPLIT);
7100 if (nrsm == NULL) {
7101 /* failed XXXrrs what can we do but loose the sack info? */
7102 struct sackblk blk;
7103
7104 blk.start = start;
7105 blk.end = end;
7106 sack_filter_reject(&bbr->r_ctl.bbr_sf, &blk);
7107 goto out;
7108 }
7109 /* Clone it */
7110 bbr_clone_rsm(bbr, nrsm, rsm, end);
7111 /* The sack block does not cover this guy fully */
7112 rsm->r_flags &= (~BBR_HAS_FIN);
7113 TAILQ_INSERT_AFTER(&bbr->r_ctl.rc_map, rsm, nrsm, r_next);
7114 if (rsm->r_in_tmap) {
7115 TAILQ_INSERT_AFTER(&bbr->r_ctl.rc_tmap, rsm, nrsm, r_tnext);
7116 nrsm->r_in_tmap = 1;
7117 }
7118 nrsm->r_dupack = 0;
7119 bbr_update_rtt(tp, bbr, rsm, to, cts, BBR_SACKED, 0);
7120 bbr_isit_a_pkt_epoch(bbr, cts, rsm, __LINE__, BBR_SACKED);
7121 changed += (rsm->r_end - rsm->r_start);
7122 bbr->r_ctl.rc_sacked += (rsm->r_end - rsm->r_start);
7123 bbr_log_sack_passed(tp, bbr, rsm);
7124 /* Is Reordering occuring? */
7125 if (rsm->r_flags & BBR_MARKED_LOST) {
7126 bbr->r_ctl.rc_lost_bytes -= rsm->r_end - rsm->r_start;
7127 }
7128 if (rsm->r_flags & BBR_SACK_PASSED) {
7129 BBR_STAT_INC(bbr_reorder_seen);
7130 bbr->r_ctl.rc_reorder_ts = cts;
7131 if (rsm->r_flags & BBR_MARKED_LOST) {
7132 bbr->r_ctl.rc_lost -= rsm->r_end - rsm->r_start;
7133 if (SEQ_GT(bbr->r_ctl.rc_lt_lost, bbr->r_ctl.rc_lost))
7134 /* LT sampling also needs adjustment */
7135 bbr->r_ctl.rc_lt_lost = bbr->r_ctl.rc_lost;
7136 }
7137 }
7138 rsm->r_flags &= ~(BBR_TLP|BBR_WAS_RENEGED|BBR_RXT_CLEARED|BBR_MARKED_LOST);
7139 rsm->r_flags |= BBR_ACKED;
7140 if (rsm->r_in_tmap) {
7141 TAILQ_REMOVE(&bbr->r_ctl.rc_tmap, rsm, r_tnext);
7142 rsm->r_in_tmap = 0;
7143 }
7144 out:
7145 if (rsm && (rsm->r_flags & BBR_ACKED)) {
7146 /*
7147 * Now can we merge this newly acked
7148 * block with either the previous or
7149 * next block?
7150 */
7151 nrsm = TAILQ_NEXT(rsm, r_next);
7152 if (nrsm &&
7153 (nrsm->r_flags & BBR_ACKED)) {
7154 /* yep this and next can be merged */
7155 rsm = bbr_merge_rsm(bbr, rsm, nrsm);
7156 }
7157 /* Now what about the previous? */
7158 nrsm = TAILQ_PREV(rsm, bbr_head, r_next);
7159 if (nrsm &&
7160 (nrsm->r_flags & BBR_ACKED)) {
7161 /* yep the previous and this can be merged */
7162 rsm = bbr_merge_rsm(bbr, nrsm, rsm);
7163 }
7164 }
7165 if (used_ref == 0) {
7166 BBR_STAT_INC(bbr_sack_proc_all);
7167 } else {
7168 BBR_STAT_INC(bbr_sack_proc_short);
7169 }
7170 if (went_fwd && went_back) {
7171 BBR_STAT_INC(bbr_sack_search_both);
7172 } else if (went_fwd) {
7173 BBR_STAT_INC(bbr_sack_search_fwd);
7174 } else if (went_back) {
7175 BBR_STAT_INC(bbr_sack_search_back);
7176 }
7177 /* Save off where the next seq is */
7178 if (rsm)
7179 bbr->r_ctl.rc_sacklast = TAILQ_NEXT(rsm, r_next);
7180 else
7181 bbr->r_ctl.rc_sacklast = NULL;
7182 *prsm = rsm;
7183 return (changed);
7184 }
7185
7186 static void inline
bbr_peer_reneges(struct tcp_bbr * bbr,struct bbr_sendmap * rsm,tcp_seq th_ack)7187 bbr_peer_reneges(struct tcp_bbr *bbr, struct bbr_sendmap *rsm, tcp_seq th_ack)
7188 {
7189 struct bbr_sendmap *tmap;
7190
7191 BBR_STAT_INC(bbr_reneges_seen);
7192 tmap = NULL;
7193 while (rsm && (rsm->r_flags & BBR_ACKED)) {
7194 /* Its no longer sacked, mark it so */
7195 uint32_t oflags;
7196 bbr->r_ctl.rc_sacked -= (rsm->r_end - rsm->r_start);
7197 #ifdef BBR_INVARIANTS
7198 if (rsm->r_in_tmap) {
7199 panic("bbr:%p rsm:%p flags:0x%x in tmap?",
7200 bbr, rsm, rsm->r_flags);
7201 }
7202 #endif
7203 oflags = rsm->r_flags;
7204 if (rsm->r_flags & BBR_MARKED_LOST) {
7205 bbr->r_ctl.rc_lost -= rsm->r_end - rsm->r_start;
7206 bbr->r_ctl.rc_lost_bytes -= rsm->r_end - rsm->r_start;
7207 if (SEQ_GT(bbr->r_ctl.rc_lt_lost, bbr->r_ctl.rc_lost))
7208 /* LT sampling also needs adjustment */
7209 bbr->r_ctl.rc_lt_lost = bbr->r_ctl.rc_lost;
7210 }
7211 rsm->r_flags &= ~(BBR_ACKED | BBR_SACK_PASSED | BBR_WAS_SACKPASS | BBR_MARKED_LOST);
7212 rsm->r_flags |= BBR_WAS_RENEGED;
7213 rsm->r_flags |= BBR_RXT_CLEARED;
7214 bbr_log_type_rsmclear(bbr, bbr->r_ctl.rc_rcvtime, rsm, oflags, __LINE__);
7215 /* Rebuild it into our tmap */
7216 if (tmap == NULL) {
7217 TAILQ_INSERT_HEAD(&bbr->r_ctl.rc_tmap, rsm, r_tnext);
7218 tmap = rsm;
7219 } else {
7220 TAILQ_INSERT_AFTER(&bbr->r_ctl.rc_tmap, tmap, rsm, r_tnext);
7221 tmap = rsm;
7222 }
7223 tmap->r_in_tmap = 1;
7224 /*
7225 * XXXrrs Delivered? Should we do anything here?
7226 *
7227 * Of course we don't on a rxt timeout so maybe its ok that
7228 * we don't?
7229 *
7230 * For now lets not.
7231 */
7232 rsm = TAILQ_NEXT(rsm, r_next);
7233 }
7234 /*
7235 * Now lets possibly clear the sack filter so we start recognizing
7236 * sacks that cover this area.
7237 */
7238 sack_filter_clear(&bbr->r_ctl.bbr_sf, th_ack);
7239 }
7240
7241 static void
bbr_log_syn(struct tcpcb * tp,struct tcpopt * to)7242 bbr_log_syn(struct tcpcb *tp, struct tcpopt *to)
7243 {
7244 struct tcp_bbr *bbr;
7245 struct bbr_sendmap *rsm;
7246 uint32_t cts;
7247
7248 bbr = (struct tcp_bbr *)tp->t_fb_ptr;
7249 cts = bbr->r_ctl.rc_rcvtime;
7250 rsm = TAILQ_FIRST(&bbr->r_ctl.rc_map);
7251 if (rsm && (rsm->r_flags & BBR_HAS_SYN)) {
7252 if ((rsm->r_end - rsm->r_start) <= 1) {
7253 /* Log out the SYN completely */
7254 bbr->r_ctl.rc_holes_rxt -= rsm->r_rtr_bytes;
7255 rsm->r_rtr_bytes = 0;
7256 TAILQ_REMOVE(&bbr->r_ctl.rc_map, rsm, r_next);
7257 if (rsm->r_in_tmap) {
7258 TAILQ_REMOVE(&bbr->r_ctl.rc_tmap, rsm, r_tnext);
7259 rsm->r_in_tmap = 0;
7260 }
7261 if (bbr->r_ctl.rc_next == rsm) {
7262 /* scoot along the marker */
7263 bbr->r_ctl.rc_next = TAILQ_FIRST(&bbr->r_ctl.rc_map);
7264 }
7265 if (to != NULL)
7266 bbr_update_rtt(tp, bbr, rsm, to, cts, BBR_CUM_ACKED, 0);
7267 bbr_free(bbr, rsm);
7268 } else {
7269 /* There is more (Fast open)? strip out SYN. */
7270 rsm->r_flags &= ~BBR_HAS_SYN;
7271 rsm->r_start++;
7272 }
7273 }
7274 }
7275
7276 /*
7277 * Returns the number of bytes that were
7278 * acknowledged by SACK blocks.
7279 */
7280
7281 static uint32_t
bbr_log_ack(struct tcpcb * tp,struct tcpopt * to,struct tcphdr * th,uint32_t * prev_acked)7282 bbr_log_ack(struct tcpcb *tp, struct tcpopt *to, struct tcphdr *th,
7283 uint32_t *prev_acked)
7284 {
7285 uint32_t changed, last_seq, entered_recovery = 0;
7286 struct tcp_bbr *bbr;
7287 struct bbr_sendmap *rsm;
7288 struct sackblk sack, sack_blocks[TCP_MAX_SACK + 1];
7289 register uint32_t th_ack;
7290 int32_t i, j, k, new_sb, num_sack_blks = 0;
7291 uint32_t cts, acked, ack_point, sack_changed = 0;
7292 uint32_t p_maxseg, maxseg, p_acked = 0;
7293
7294 INP_WLOCK_ASSERT(tptoinpcb(tp));
7295 if (tcp_get_flags(th) & TH_RST) {
7296 /* We don't log resets */
7297 return (0);
7298 }
7299 bbr = (struct tcp_bbr *)tp->t_fb_ptr;
7300 cts = bbr->r_ctl.rc_rcvtime;
7301
7302 rsm = TAILQ_FIRST(&bbr->r_ctl.rc_map);
7303 changed = 0;
7304 maxseg = tp->t_maxseg - bbr->rc_last_options;
7305 p_maxseg = min(bbr->r_ctl.rc_pace_max_segs, maxseg);
7306 th_ack = th->th_ack;
7307 if (SEQ_GT(th_ack, tp->snd_una)) {
7308 bbr_log_progress_event(bbr, tp, ticks, PROGRESS_UPDATE, __LINE__);
7309 bbr->rc_tp->t_acktime = ticks;
7310 }
7311 if (SEQ_LEQ(th_ack, tp->snd_una)) {
7312 /* Only sent here for sack processing */
7313 goto proc_sack;
7314 }
7315 if (rsm && SEQ_GT(th_ack, rsm->r_start)) {
7316 changed = th_ack - rsm->r_start;
7317 } else if ((rsm == NULL) && ((th_ack - 1) == tp->iss)) {
7318 /*
7319 * For the SYN incoming case we will not have called
7320 * tcp_output for the sending of the SYN, so there will be
7321 * no map. All other cases should probably be a panic.
7322 */
7323 if ((to->to_flags & TOF_TS) && (to->to_tsecr != 0)) {
7324 /*
7325 * We have a timestamp that can be used to generate
7326 * an initial RTT.
7327 */
7328 uint32_t ts, now, rtt;
7329
7330 ts = bbr_ts_convert(to->to_tsecr);
7331 now = bbr_ts_convert(tcp_tv_to_msec(&bbr->rc_tv));
7332 rtt = now - ts;
7333 if (rtt < 1)
7334 rtt = 1;
7335 bbr_log_type_bbrrttprop(bbr, rtt,
7336 tp->iss, 0, cts,
7337 BBR_RTT_BY_TIMESTAMP, tp->iss, 0);
7338 apply_filter_min_small(&bbr->r_ctl.rc_rttprop, rtt, cts);
7339 changed = 1;
7340 bbr->r_wanted_output = 1;
7341 goto out;
7342 }
7343 goto proc_sack;
7344 } else if (rsm == NULL) {
7345 goto out;
7346 }
7347 if (changed) {
7348 /*
7349 * The ACK point is advancing to th_ack, we must drop off
7350 * the packets in the rack log and calculate any eligble
7351 * RTT's.
7352 */
7353 bbr->r_wanted_output = 1;
7354 more:
7355 if (rsm == NULL) {
7356 if (tp->t_flags & TF_SENTFIN) {
7357 /* if we send a FIN we will not hav a map */
7358 goto proc_sack;
7359 }
7360 #ifdef BBR_INVARIANTS
7361 panic("No rack map tp:%p for th:%p state:%d bbr:%p snd_una:%u snd_max:%u chg:%d\n",
7362 tp,
7363 th, tp->t_state, bbr,
7364 tp->snd_una, tp->snd_max, changed);
7365 #endif
7366 goto proc_sack;
7367 }
7368 }
7369 if (SEQ_LT(th_ack, rsm->r_start)) {
7370 /* Huh map is missing this */
7371 #ifdef BBR_INVARIANTS
7372 printf("Rack map starts at r_start:%u for th_ack:%u huh? ts:%d rs:%d bbr:%p\n",
7373 rsm->r_start,
7374 th_ack, tp->t_state,
7375 bbr->r_state, bbr);
7376 panic("th-ack is bad bbr:%p tp:%p", bbr, tp);
7377 #endif
7378 goto proc_sack;
7379 } else if (th_ack == rsm->r_start) {
7380 /* None here to ack */
7381 goto proc_sack;
7382 }
7383 /*
7384 * Clear the dup ack counter, it will
7385 * either be freed or if there is some
7386 * remaining we need to start it at zero.
7387 */
7388 rsm->r_dupack = 0;
7389 /* Now do we consume the whole thing? */
7390 if (SEQ_GEQ(th_ack, rsm->r_end)) {
7391 /* Its all consumed. */
7392 uint32_t left;
7393
7394 if (rsm->r_flags & BBR_ACKED) {
7395 /*
7396 * It was acked on the scoreboard -- remove it from
7397 * total
7398 */
7399 p_acked += (rsm->r_end - rsm->r_start);
7400 bbr->r_ctl.rc_sacked -= (rsm->r_end - rsm->r_start);
7401 if (bbr->r_ctl.rc_sacked == 0)
7402 bbr->r_ctl.rc_sacklast = NULL;
7403 } else {
7404 bbr_update_rtt(tp, bbr, rsm, to, cts, BBR_CUM_ACKED, th_ack);
7405 if (rsm->r_flags & BBR_MARKED_LOST) {
7406 bbr->r_ctl.rc_lost_bytes -= rsm->r_end - rsm->r_start;
7407 }
7408 if (rsm->r_flags & BBR_SACK_PASSED) {
7409 /*
7410 * There are acked segments ACKED on the
7411 * scoreboard further up. We are seeing
7412 * reordering.
7413 */
7414 BBR_STAT_INC(bbr_reorder_seen);
7415 bbr->r_ctl.rc_reorder_ts = cts;
7416 if (rsm->r_flags & BBR_MARKED_LOST) {
7417 bbr->r_ctl.rc_lost -= rsm->r_end - rsm->r_start;
7418 if (SEQ_GT(bbr->r_ctl.rc_lt_lost, bbr->r_ctl.rc_lost))
7419 /* LT sampling also needs adjustment */
7420 bbr->r_ctl.rc_lt_lost = bbr->r_ctl.rc_lost;
7421 }
7422 }
7423 rsm->r_flags &= ~BBR_MARKED_LOST;
7424 }
7425 bbr->r_ctl.rc_holes_rxt -= rsm->r_rtr_bytes;
7426 rsm->r_rtr_bytes = 0;
7427 TAILQ_REMOVE(&bbr->r_ctl.rc_map, rsm, r_next);
7428 if (rsm->r_in_tmap) {
7429 TAILQ_REMOVE(&bbr->r_ctl.rc_tmap, rsm, r_tnext);
7430 rsm->r_in_tmap = 0;
7431 }
7432 if (bbr->r_ctl.rc_next == rsm) {
7433 /* scoot along the marker */
7434 bbr->r_ctl.rc_next = TAILQ_FIRST(&bbr->r_ctl.rc_map);
7435 }
7436 bbr_isit_a_pkt_epoch(bbr, cts, rsm, __LINE__, BBR_CUM_ACKED);
7437 /* Adjust the packet counts */
7438 left = th_ack - rsm->r_end;
7439 /* Free back to zone */
7440 bbr_free(bbr, rsm);
7441 if (left) {
7442 rsm = TAILQ_FIRST(&bbr->r_ctl.rc_map);
7443 goto more;
7444 }
7445 goto proc_sack;
7446 }
7447 if (rsm->r_flags & BBR_ACKED) {
7448 /*
7449 * It was acked on the scoreboard -- remove it from total
7450 * for the part being cum-acked.
7451 */
7452 p_acked += (rsm->r_end - rsm->r_start);
7453 bbr->r_ctl.rc_sacked -= (th_ack - rsm->r_start);
7454 if (bbr->r_ctl.rc_sacked == 0)
7455 bbr->r_ctl.rc_sacklast = NULL;
7456 } else {
7457 /*
7458 * It was acked up to th_ack point for the first time
7459 */
7460 struct bbr_sendmap lrsm;
7461
7462 memcpy(&lrsm, rsm, sizeof(struct bbr_sendmap));
7463 lrsm.r_end = th_ack;
7464 bbr_update_rtt(tp, bbr, &lrsm, to, cts, BBR_CUM_ACKED, th_ack);
7465 }
7466 if ((rsm->r_flags & BBR_MARKED_LOST) &&
7467 ((rsm->r_flags & BBR_ACKED) == 0)) {
7468 /*
7469 * It was marked lost and partly ack'd now
7470 * for the first time. We lower the rc_lost_bytes
7471 * and still leave it MARKED.
7472 */
7473 bbr->r_ctl.rc_lost_bytes -= th_ack - rsm->r_start;
7474 }
7475 bbr_isit_a_pkt_epoch(bbr, cts, rsm, __LINE__, BBR_CUM_ACKED);
7476 bbr->r_ctl.rc_holes_rxt -= rsm->r_rtr_bytes;
7477 rsm->r_rtr_bytes = 0;
7478 /* adjust packet count */
7479 rsm->r_start = th_ack;
7480 proc_sack:
7481 /* Check for reneging */
7482 rsm = TAILQ_FIRST(&bbr->r_ctl.rc_map);
7483 if (rsm && (rsm->r_flags & BBR_ACKED) && (th_ack == rsm->r_start)) {
7484 /*
7485 * The peer has moved snd_una up to the edge of this send,
7486 * i.e. one that it had previously acked. The only way that
7487 * can be true if the peer threw away data (space issues)
7488 * that it had previously sacked (else it would have given
7489 * us snd_una up to (rsm->r_end). We need to undo the acked
7490 * markings here.
7491 *
7492 * Note we have to look to make sure th_ack is our
7493 * rsm->r_start in case we get an old ack where th_ack is
7494 * behind snd_una.
7495 */
7496 bbr_peer_reneges(bbr, rsm, th->th_ack);
7497 }
7498 if ((to->to_flags & TOF_SACK) == 0) {
7499 /* We are done nothing left to log */
7500 goto out;
7501 }
7502 rsm = TAILQ_LAST_FAST(&bbr->r_ctl.rc_map, bbr_sendmap, r_next);
7503 if (rsm) {
7504 last_seq = rsm->r_end;
7505 } else {
7506 last_seq = tp->snd_max;
7507 }
7508 /* Sack block processing */
7509 if (SEQ_GT(th_ack, tp->snd_una))
7510 ack_point = th_ack;
7511 else
7512 ack_point = tp->snd_una;
7513 for (i = 0; i < to->to_nsacks; i++) {
7514 bcopy((to->to_sacks + i * TCPOLEN_SACK),
7515 &sack, sizeof(sack));
7516 sack.start = ntohl(sack.start);
7517 sack.end = ntohl(sack.end);
7518 if (SEQ_GT(sack.end, sack.start) &&
7519 SEQ_GT(sack.start, ack_point) &&
7520 SEQ_LT(sack.start, tp->snd_max) &&
7521 SEQ_GT(sack.end, ack_point) &&
7522 SEQ_LEQ(sack.end, tp->snd_max)) {
7523 if ((bbr->r_ctl.rc_num_small_maps_alloced > bbr_sack_block_limit) &&
7524 (SEQ_LT(sack.end, last_seq)) &&
7525 ((sack.end - sack.start) < (p_maxseg / 8))) {
7526 /*
7527 * Not the last piece and its smaller than
7528 * 1/8th of a p_maxseg. We ignore this.
7529 */
7530 BBR_STAT_INC(bbr_runt_sacks);
7531 continue;
7532 }
7533 sack_blocks[num_sack_blks] = sack;
7534 num_sack_blks++;
7535 } else if (SEQ_LEQ(sack.start, th_ack) &&
7536 SEQ_LEQ(sack.end, th_ack)) {
7537 /*
7538 * Its a D-SACK block.
7539 */
7540 tcp_record_dsack(tp, sack.start, sack.end, 0);
7541 }
7542 }
7543 if (num_sack_blks == 0)
7544 goto out;
7545 /*
7546 * Sort the SACK blocks so we can update the rack scoreboard with
7547 * just one pass.
7548 */
7549 new_sb = sack_filter_blks(tp, &bbr->r_ctl.bbr_sf, sack_blocks,
7550 num_sack_blks, th->th_ack);
7551 ctf_log_sack_filter(bbr->rc_tp, new_sb, sack_blocks);
7552 BBR_STAT_ADD(bbr_sack_blocks, num_sack_blks);
7553 BBR_STAT_ADD(bbr_sack_blocks_skip, (num_sack_blks - new_sb));
7554 num_sack_blks = new_sb;
7555 if (num_sack_blks < 2) {
7556 goto do_sack_work;
7557 }
7558 /* Sort the sacks */
7559 for (i = 0; i < num_sack_blks; i++) {
7560 for (j = i + 1; j < num_sack_blks; j++) {
7561 if (SEQ_GT(sack_blocks[i].end, sack_blocks[j].end)) {
7562 sack = sack_blocks[i];
7563 sack_blocks[i] = sack_blocks[j];
7564 sack_blocks[j] = sack;
7565 }
7566 }
7567 }
7568 /*
7569 * Now are any of the sack block ends the same (yes some
7570 * implememtations send these)?
7571 */
7572 again:
7573 if (num_sack_blks > 1) {
7574 for (i = 0; i < num_sack_blks; i++) {
7575 for (j = i + 1; j < num_sack_blks; j++) {
7576 if (sack_blocks[i].end == sack_blocks[j].end) {
7577 /*
7578 * Ok these two have the same end we
7579 * want the smallest end and then
7580 * throw away the larger and start
7581 * again.
7582 */
7583 if (SEQ_LT(sack_blocks[j].start, sack_blocks[i].start)) {
7584 /*
7585 * The second block covers
7586 * more area use that
7587 */
7588 sack_blocks[i].start = sack_blocks[j].start;
7589 }
7590 /*
7591 * Now collapse out the dup-sack and
7592 * lower the count
7593 */
7594 for (k = (j + 1); k < num_sack_blks; k++) {
7595 sack_blocks[j].start = sack_blocks[k].start;
7596 sack_blocks[j].end = sack_blocks[k].end;
7597 j++;
7598 }
7599 num_sack_blks--;
7600 goto again;
7601 }
7602 }
7603 }
7604 }
7605 do_sack_work:
7606 rsm = bbr->r_ctl.rc_sacklast;
7607 for (i = 0; i < num_sack_blks; i++) {
7608 acked = bbr_proc_sack_blk(tp, bbr, &sack_blocks[i], to, &rsm, cts);
7609 if (acked) {
7610 bbr->r_wanted_output = 1;
7611 changed += acked;
7612 sack_changed += acked;
7613 }
7614 }
7615 out:
7616 *prev_acked = p_acked;
7617 if ((sack_changed) && (!IN_RECOVERY(tp->t_flags))) {
7618 /*
7619 * Ok we have a high probability that we need to go in to
7620 * recovery since we have data sack'd
7621 */
7622 struct bbr_sendmap *rsm;
7623
7624 rsm = bbr_check_recovery_mode(tp, bbr, cts);
7625 if (rsm) {
7626 /* Enter recovery */
7627 entered_recovery = 1;
7628 bbr->r_wanted_output = 1;
7629 /*
7630 * When we enter recovery we need to assure we send
7631 * one packet.
7632 */
7633 if (bbr->r_ctl.rc_resend == NULL) {
7634 bbr->r_ctl.rc_resend = rsm;
7635 }
7636 }
7637 }
7638 if (IN_RECOVERY(tp->t_flags) && (entered_recovery == 0)) {
7639 /*
7640 * See if we need to rack-retransmit anything if so set it
7641 * up as the thing to resend assuming something else is not
7642 * already in that position.
7643 */
7644 if (bbr->r_ctl.rc_resend == NULL) {
7645 bbr->r_ctl.rc_resend = bbr_check_recovery_mode(tp, bbr, cts);
7646 }
7647 }
7648 /*
7649 * We return the amount that changed via sack, this is used by the
7650 * ack-received code to augment what was changed between th_ack <->
7651 * snd_una.
7652 */
7653 return (sack_changed);
7654 }
7655
7656 static void
bbr_strike_dupack(struct tcp_bbr * bbr)7657 bbr_strike_dupack(struct tcp_bbr *bbr)
7658 {
7659 struct bbr_sendmap *rsm;
7660
7661 rsm = TAILQ_FIRST(&bbr->r_ctl.rc_tmap);
7662 if (rsm && (rsm->r_dupack < 0xff)) {
7663 rsm->r_dupack++;
7664 if (rsm->r_dupack >= DUP_ACK_THRESHOLD)
7665 bbr->r_wanted_output = 1;
7666 }
7667 }
7668
7669 /*
7670 * Return value of 1, we do not need to call bbr_process_data().
7671 * return value of 0, bbr_process_data can be called.
7672 * For ret_val if its 0 the TCB is locked and valid, if its non-zero
7673 * its unlocked and probably unsafe to touch the TCB.
7674 */
7675 static int
bbr_process_ack(struct mbuf * m,struct tcphdr * th,struct socket * so,struct tcpcb * tp,struct tcpopt * to,uint32_t tiwin,int32_t tlen,int32_t * ofia,int32_t thflags,int32_t * ret_val)7676 bbr_process_ack(struct mbuf *m, struct tcphdr *th, struct socket *so,
7677 struct tcpcb *tp, struct tcpopt *to,
7678 uint32_t tiwin, int32_t tlen,
7679 int32_t * ofia, int32_t thflags, int32_t * ret_val)
7680 {
7681 int32_t ourfinisacked = 0;
7682 int32_t acked_amount;
7683 uint16_t nsegs;
7684 int32_t acked;
7685 uint32_t lost, sack_changed = 0;
7686 struct mbuf *mfree;
7687 struct tcp_bbr *bbr;
7688 uint32_t prev_acked = 0;
7689
7690 bbr = (struct tcp_bbr *)tp->t_fb_ptr;
7691 lost = bbr->r_ctl.rc_lost;
7692 nsegs = max(1, m->m_pkthdr.lro_nsegs);
7693 if (SEQ_GEQ(tp->snd_una, tp->iss + (65535 << tp->snd_scale))) {
7694 /* Checking SEG.ACK against ISS is definitely redundant. */
7695 tp->t_flags2 |= TF2_NO_ISS_CHECK;
7696 }
7697 if (!V_tcp_insecure_ack) {
7698 tcp_seq seq_min;
7699 bool ghost_ack_check;
7700
7701 if (tp->t_flags2 & TF2_NO_ISS_CHECK) {
7702 /* Check for too old ACKs (RFC 5961, Section 5.2). */
7703 seq_min = tp->snd_una - tp->max_sndwnd;
7704 ghost_ack_check = false;
7705 } else {
7706 if (SEQ_GT(tp->iss + 1, tp->snd_una - tp->max_sndwnd)) {
7707 /* Checking for ghost ACKs is stricter. */
7708 seq_min = tp->iss + 1;
7709 ghost_ack_check = true;
7710 } else {
7711 /*
7712 * Checking for too old ACKs (RFC 5961,
7713 * Section 5.2) is stricter.
7714 */
7715 seq_min = tp->snd_una - tp->max_sndwnd;
7716 ghost_ack_check = false;
7717 }
7718 }
7719 if (SEQ_LT(th->th_ack, seq_min)) {
7720 if (ghost_ack_check)
7721 TCPSTAT_INC(tcps_rcvghostack);
7722 else
7723 TCPSTAT_INC(tcps_rcvacktooold);
7724 /* Send challenge ACK. */
7725 ctf_do_dropafterack(m, tp, th, thflags, tlen, ret_val);
7726 bbr->r_wanted_output = 1;
7727 return (1);
7728 }
7729 }
7730 if (SEQ_GT(th->th_ack, tp->snd_max)) {
7731 ctf_do_dropafterack(m, tp, th, thflags, tlen, ret_val);
7732 bbr->r_wanted_output = 1;
7733 return (1);
7734 }
7735 if (SEQ_GEQ(th->th_ack, tp->snd_una) || to->to_nsacks) {
7736 /* Process the ack */
7737 if (bbr->rc_in_persist)
7738 tp->t_rxtshift = 0;
7739 if ((th->th_ack == tp->snd_una) && (tiwin == tp->snd_wnd))
7740 bbr_strike_dupack(bbr);
7741 sack_changed = bbr_log_ack(tp, to, th, &prev_acked);
7742 }
7743 bbr_lt_bw_sampling(bbr, bbr->r_ctl.rc_rcvtime, (bbr->r_ctl.rc_lost > lost));
7744 if (__predict_false(SEQ_LEQ(th->th_ack, tp->snd_una))) {
7745 /*
7746 * Old ack, behind the last one rcv'd or a duplicate ack
7747 * with SACK info.
7748 */
7749 if (th->th_ack == tp->snd_una) {
7750 bbr_ack_received(tp, bbr, th, 0, sack_changed, prev_acked, __LINE__, 0);
7751 if (bbr->r_state == TCPS_SYN_SENT) {
7752 /*
7753 * Special case on where we sent SYN. When
7754 * the SYN-ACK is processed in syn_sent
7755 * state it bumps the snd_una. This causes
7756 * us to hit here even though we did ack 1
7757 * byte.
7758 *
7759 * Go through the nothing left case so we
7760 * send data.
7761 */
7762 goto nothing_left;
7763 }
7764 }
7765 return (0);
7766 }
7767 /*
7768 * If we reach this point, ACK is not a duplicate, i.e., it ACKs
7769 * something we sent.
7770 */
7771 if (tp->t_flags & TF_NEEDSYN) {
7772 /*
7773 * T/TCP: Connection was half-synchronized, and our SYN has
7774 * been ACK'd (so connection is now fully synchronized). Go
7775 * to non-starred state, increment snd_una for ACK of SYN,
7776 * and check if we can do window scaling.
7777 */
7778 tp->t_flags &= ~TF_NEEDSYN;
7779 tp->snd_una++;
7780 /* Do window scaling? */
7781 if ((tp->t_flags & (TF_RCVD_SCALE | TF_REQ_SCALE)) ==
7782 (TF_RCVD_SCALE | TF_REQ_SCALE)) {
7783 tp->rcv_scale = tp->request_r_scale;
7784 /* Send window already scaled. */
7785 }
7786 }
7787 INP_WLOCK_ASSERT(tptoinpcb(tp));
7788
7789 acked = BYTES_THIS_ACK(tp, th);
7790 KMOD_TCPSTAT_ADD(tcps_rcvackpack, (int)nsegs);
7791 KMOD_TCPSTAT_ADD(tcps_rcvackbyte, acked);
7792
7793 /*
7794 * If we just performed our first retransmit, and the ACK arrives
7795 * within our recovery window, then it was a mistake to do the
7796 * retransmit in the first place. Recover our original cwnd and
7797 * ssthresh, and proceed to transmit where we left off.
7798 */
7799 if (tp->t_flags & TF_PREVVALID) {
7800 tp->t_flags &= ~TF_PREVVALID;
7801 if (tp->t_rxtshift == 1 &&
7802 (int)(ticks - tp->t_badrxtwin) < 0)
7803 bbr_cong_signal(tp, th, CC_RTO_ERR, NULL);
7804 }
7805 SOCK_SENDBUF_LOCK(so);
7806 acked_amount = min(acked, (int)sbavail(&so->so_snd));
7807 tp->snd_wnd -= acked_amount;
7808 mfree = sbcut_locked(&so->so_snd, acked_amount);
7809 /* NB: sowwakeup_locked() does an implicit unlock. */
7810 sowwakeup_locked(so);
7811 m_freem(mfree);
7812 if (SEQ_GT(th->th_ack, tp->snd_una)) {
7813 bbr_collapse_rtt(tp, bbr, TCP_REXMTVAL(tp));
7814 }
7815 tp->snd_una = th->th_ack;
7816 bbr_ack_received(tp, bbr, th, acked, sack_changed, prev_acked, __LINE__, (bbr->r_ctl.rc_lost - lost));
7817 if (IN_RECOVERY(tp->t_flags)) {
7818 if (SEQ_LT(th->th_ack, tp->snd_recover) &&
7819 (SEQ_LT(th->th_ack, tp->snd_max))) {
7820 tcp_bbr_partialack(tp);
7821 } else {
7822 bbr_post_recovery(tp);
7823 }
7824 }
7825 if (SEQ_GT(tp->snd_una, tp->snd_recover)) {
7826 tp->snd_recover = tp->snd_una;
7827 }
7828 if (SEQ_LT(tp->snd_nxt, tp->snd_max)) {
7829 tp->snd_nxt = tp->snd_max;
7830 }
7831 if (tp->snd_una == tp->snd_max) {
7832 /* Nothing left outstanding */
7833 nothing_left:
7834 bbr_log_progress_event(bbr, tp, ticks, PROGRESS_CLEAR, __LINE__);
7835 if (sbavail(&so->so_snd) == 0)
7836 bbr->rc_tp->t_acktime = 0;
7837 if ((sbused(&so->so_snd) == 0) &&
7838 (tp->t_flags & TF_SENTFIN)) {
7839 ourfinisacked = 1;
7840 }
7841 bbr_timer_cancel(bbr, __LINE__, bbr->r_ctl.rc_rcvtime);
7842 if (bbr->rc_in_persist == 0) {
7843 bbr->r_ctl.rc_went_idle_time = bbr->r_ctl.rc_rcvtime;
7844 }
7845 sack_filter_clear(&bbr->r_ctl.bbr_sf, tp->snd_una);
7846 bbr_log_ack_clear(bbr, bbr->r_ctl.rc_rcvtime);
7847 /*
7848 * We invalidate the last ack here since we
7849 * don't want to transfer forward the time
7850 * for our sum's calculations.
7851 */
7852 if ((tp->t_state >= TCPS_FIN_WAIT_1) &&
7853 (sbavail(&so->so_snd) == 0) &&
7854 (tp->t_flags2 & TF2_DROP_AF_DATA)) {
7855 /*
7856 * The socket was gone and the peer sent data, time
7857 * to reset him.
7858 */
7859 *ret_val = 1;
7860 tcp_log_end_status(tp, TCP_EI_STATUS_DATA_A_CLOSE);
7861 /* tcp_close will kill the inp pre-log the Reset */
7862 tcp_log_end_status(tp, TCP_EI_STATUS_SERVER_RST);
7863 tp = tcp_close(tp);
7864 ctf_do_dropwithreset(m, tp, th, tlen);
7865 BBR_STAT_INC(bbr_dropped_af_data);
7866 return (1);
7867 }
7868 /* Set need output so persist might get set */
7869 bbr->r_wanted_output = 1;
7870 }
7871 if (ofia)
7872 *ofia = ourfinisacked;
7873 return (0);
7874 }
7875
7876 static void
bbr_enter_persist(struct tcpcb * tp,struct tcp_bbr * bbr,uint32_t cts,int32_t line)7877 bbr_enter_persist(struct tcpcb *tp, struct tcp_bbr *bbr, uint32_t cts, int32_t line)
7878 {
7879 if (bbr->rc_in_persist == 0) {
7880 bbr_timer_cancel(bbr, __LINE__, cts);
7881 bbr->r_ctl.rc_last_delay_val = 0;
7882 tp->t_rxtshift = 0;
7883 bbr->rc_in_persist = 1;
7884 bbr->r_ctl.rc_went_idle_time = cts;
7885 /* We should be capped when rw went to 0 but just in case */
7886 bbr_log_type_pesist(bbr, cts, 0, line, 1);
7887 /* Time freezes for the state, so do the accounting now */
7888 if (SEQ_GT(cts, bbr->r_ctl.rc_bbr_state_time)) {
7889 uint32_t time_in;
7890
7891 time_in = cts - bbr->r_ctl.rc_bbr_state_time;
7892 if (bbr->rc_bbr_state == BBR_STATE_PROBE_BW) {
7893 int32_t idx;
7894
7895 idx = bbr_state_val(bbr);
7896 counter_u64_add(bbr_state_time[(idx + 5)], time_in);
7897 } else {
7898 counter_u64_add(bbr_state_time[bbr->rc_bbr_state], time_in);
7899 }
7900 }
7901 bbr->r_ctl.rc_bbr_state_time = cts;
7902 }
7903 }
7904
7905 static void
bbr_restart_after_idle(struct tcp_bbr * bbr,uint32_t cts,uint32_t idle_time)7906 bbr_restart_after_idle(struct tcp_bbr *bbr, uint32_t cts, uint32_t idle_time)
7907 {
7908 /*
7909 * Note that if idle time does not exceed our
7910 * threshold, we do nothing continuing the state
7911 * transitions we were last walking through.
7912 */
7913 if (idle_time >= bbr_idle_restart_threshold) {
7914 if (bbr->rc_use_idle_restart) {
7915 bbr->rc_bbr_state = BBR_STATE_IDLE_EXIT;
7916 /*
7917 * Set our target using BBR_UNIT, so
7918 * we increase at a dramatic rate but
7919 * we stop when we get the pipe
7920 * full again for our current b/w estimate.
7921 */
7922 bbr->r_ctl.rc_bbr_hptsi_gain = BBR_UNIT;
7923 bbr->r_ctl.rc_bbr_cwnd_gain = BBR_UNIT;
7924 bbr_set_state_target(bbr, __LINE__);
7925 /* Now setup our gains to ramp up */
7926 bbr->r_ctl.rc_bbr_hptsi_gain = bbr->r_ctl.rc_startup_pg;
7927 bbr->r_ctl.rc_bbr_cwnd_gain = bbr->r_ctl.rc_startup_pg;
7928 bbr_log_type_statechange(bbr, cts, __LINE__);
7929 } else if (bbr->rc_bbr_state == BBR_STATE_PROBE_BW) {
7930 bbr_substate_change(bbr, cts, __LINE__, 1);
7931 }
7932 }
7933 }
7934
7935 static void
bbr_exit_persist(struct tcpcb * tp,struct tcp_bbr * bbr,uint32_t cts,int32_t line)7936 bbr_exit_persist(struct tcpcb *tp, struct tcp_bbr *bbr, uint32_t cts, int32_t line)
7937 {
7938 uint32_t idle_time;
7939
7940 if (bbr->rc_in_persist == 0)
7941 return;
7942 idle_time = bbr_calc_time(cts, bbr->r_ctl.rc_went_idle_time);
7943 bbr->rc_in_persist = 0;
7944 bbr->rc_hit_state_1 = 0;
7945 bbr->r_ctl.rc_del_time = cts;
7946 /*
7947 * We invalidate the last ack here since we
7948 * don't want to transfer forward the time
7949 * for our sum's calculations.
7950 */
7951 if (tcp_in_hpts(bbr->rc_tp)) {
7952 tcp_hpts_remove(bbr->rc_tp);
7953 bbr->rc_timer_first = 0;
7954 bbr->r_ctl.rc_hpts_flags = 0;
7955 bbr->r_ctl.rc_last_delay_val = 0;
7956 bbr->r_ctl.rc_hptsi_agg_delay = 0;
7957 bbr->r_agg_early_set = 0;
7958 bbr->r_ctl.rc_agg_early = 0;
7959 }
7960 bbr_log_type_pesist(bbr, cts, idle_time, line, 0);
7961 if (idle_time >= bbr_rtt_probe_time) {
7962 /*
7963 * This qualifies as a RTT_PROBE session since we drop the
7964 * data outstanding to nothing and waited more than
7965 * bbr_rtt_probe_time.
7966 */
7967 bbr_log_rtt_shrinks(bbr, cts, 0, 0, __LINE__, BBR_RTTS_PERSIST, 0);
7968 bbr->r_ctl.last_in_probertt = bbr->r_ctl.rc_rtt_shrinks = cts;
7969 }
7970 tp->t_rxtshift = 0;
7971 /*
7972 * If in probeBW and we have persisted more than an RTT lets do
7973 * special handling.
7974 */
7975 /* Force a time based epoch */
7976 bbr_set_epoch(bbr, cts, __LINE__);
7977 /*
7978 * Setup the lost so we don't count anything against the guy
7979 * we have been stuck with during persists.
7980 */
7981 bbr->r_ctl.bbr_lost_at_state = bbr->r_ctl.rc_lost;
7982 /* Time un-freezes for the state */
7983 bbr->r_ctl.rc_bbr_state_time = cts;
7984 if ((bbr->rc_bbr_state == BBR_STATE_PROBE_BW) ||
7985 (bbr->rc_bbr_state == BBR_STATE_PROBE_RTT)) {
7986 /*
7987 * If we are going back to probe-bw
7988 * or probe_rtt, we may need to possibly
7989 * do a fast restart.
7990 */
7991 bbr_restart_after_idle(bbr, cts, idle_time);
7992 }
7993 }
7994
7995 static void
bbr_collapsed_window(struct tcp_bbr * bbr)7996 bbr_collapsed_window(struct tcp_bbr *bbr)
7997 {
7998 /*
7999 * Now we must walk the
8000 * send map and divide the
8001 * ones left stranded. These
8002 * guys can't cause us to abort
8003 * the connection and are really
8004 * "unsent". However if a buggy
8005 * client actually did keep some
8006 * of the data i.e. collapsed the win
8007 * and refused to ack and then opened
8008 * the win and acked that data. We would
8009 * get into an ack war, the simplier
8010 * method then of just pretending we
8011 * did not send those segments something
8012 * won't work.
8013 */
8014 struct bbr_sendmap *rsm, *nrsm;
8015 tcp_seq max_seq;
8016 uint32_t maxseg;
8017 int can_split = 0;
8018 int fnd = 0;
8019
8020 maxseg = bbr->rc_tp->t_maxseg - bbr->rc_last_options;
8021 max_seq = bbr->rc_tp->snd_una + bbr->rc_tp->snd_wnd;
8022 bbr_log_type_rwnd_collapse(bbr, max_seq, 1, 0);
8023 TAILQ_FOREACH(rsm, &bbr->r_ctl.rc_map, r_next) {
8024 /* Find the first seq past or at maxseq */
8025 if (rsm->r_flags & BBR_RWND_COLLAPSED)
8026 rsm->r_flags &= ~BBR_RWND_COLLAPSED;
8027 if (SEQ_GEQ(max_seq, rsm->r_start) &&
8028 SEQ_GEQ(rsm->r_end, max_seq)) {
8029 fnd = 1;
8030 break;
8031 }
8032 }
8033 bbr->rc_has_collapsed = 0;
8034 if (!fnd) {
8035 /* Nothing to do strange */
8036 return;
8037 }
8038 /*
8039 * Now can we split?
8040 *
8041 * We don't want to split if splitting
8042 * would generate too many small segments
8043 * less we let an attacker fragment our
8044 * send_map and leave us out of memory.
8045 */
8046 if ((max_seq != rsm->r_start) &&
8047 (max_seq != rsm->r_end)){
8048 /* can we split? */
8049 int res1, res2;
8050
8051 res1 = max_seq - rsm->r_start;
8052 res2 = rsm->r_end - max_seq;
8053 if ((res1 >= (maxseg/8)) &&
8054 (res2 >= (maxseg/8))) {
8055 /* No small pieces here */
8056 can_split = 1;
8057 } else if (bbr->r_ctl.rc_num_small_maps_alloced < bbr_sack_block_limit) {
8058 /* We are under the limit */
8059 can_split = 1;
8060 }
8061 }
8062 /* Ok do we need to split this rsm? */
8063 if (max_seq == rsm->r_start) {
8064 /* It's this guy no split required */
8065 nrsm = rsm;
8066 } else if (max_seq == rsm->r_end) {
8067 /* It's the next one no split required. */
8068 nrsm = TAILQ_NEXT(rsm, r_next);
8069 if (nrsm == NULL) {
8070 /* Huh? */
8071 return;
8072 }
8073 } else if (can_split && SEQ_LT(max_seq, rsm->r_end)) {
8074 /* yep we need to split it */
8075 nrsm = bbr_alloc_limit(bbr, BBR_LIMIT_TYPE_SPLIT);
8076 if (nrsm == NULL) {
8077 /* failed XXXrrs what can we do mark the whole? */
8078 nrsm = rsm;
8079 goto no_split;
8080 }
8081 /* Clone it */
8082 bbr_log_type_rwnd_collapse(bbr, max_seq, 3, 0);
8083 bbr_clone_rsm(bbr, nrsm, rsm, max_seq);
8084 TAILQ_INSERT_AFTER(&bbr->r_ctl.rc_map, rsm, nrsm, r_next);
8085 if (rsm->r_in_tmap) {
8086 TAILQ_INSERT_AFTER(&bbr->r_ctl.rc_tmap, rsm, nrsm, r_tnext);
8087 nrsm->r_in_tmap = 1;
8088 }
8089 } else {
8090 /*
8091 * Split not allowed just start here just
8092 * use this guy.
8093 */
8094 nrsm = rsm;
8095 }
8096 no_split:
8097 BBR_STAT_INC(bbr_collapsed_win);
8098 /* reuse fnd as a count */
8099 fnd = 0;
8100 TAILQ_FOREACH_FROM(nrsm, &bbr->r_ctl.rc_map, r_next) {
8101 nrsm->r_flags |= BBR_RWND_COLLAPSED;
8102 fnd++;
8103 bbr->rc_has_collapsed = 1;
8104 }
8105 bbr_log_type_rwnd_collapse(bbr, max_seq, 4, fnd);
8106 }
8107
8108 static void
bbr_un_collapse_window(struct tcp_bbr * bbr)8109 bbr_un_collapse_window(struct tcp_bbr *bbr)
8110 {
8111 struct bbr_sendmap *rsm;
8112 int cleared = 0;
8113
8114 TAILQ_FOREACH_REVERSE(rsm, &bbr->r_ctl.rc_map, bbr_head, r_next) {
8115 if (rsm->r_flags & BBR_RWND_COLLAPSED) {
8116 /* Clear the flag */
8117 rsm->r_flags &= ~BBR_RWND_COLLAPSED;
8118 cleared++;
8119 } else
8120 break;
8121 }
8122 bbr_log_type_rwnd_collapse(bbr,
8123 (bbr->rc_tp->snd_una + bbr->rc_tp->snd_wnd), 0, cleared);
8124 bbr->rc_has_collapsed = 0;
8125 }
8126
8127 /*
8128 * Return value of 1, the TCB is unlocked and most
8129 * likely gone, return value of 0, the TCB is still
8130 * locked.
8131 */
8132 static int
bbr_process_data(struct mbuf * m,struct tcphdr * th,struct socket * so,struct tcpcb * tp,int32_t drop_hdrlen,int32_t tlen,uint32_t tiwin,int32_t thflags,int32_t nxt_pkt)8133 bbr_process_data(struct mbuf *m, struct tcphdr *th, struct socket *so,
8134 struct tcpcb *tp, int32_t drop_hdrlen, int32_t tlen,
8135 uint32_t tiwin, int32_t thflags, int32_t nxt_pkt)
8136 {
8137 /*
8138 * Update window information. Don't look at window if no ACK: TAC's
8139 * send garbage on first SYN.
8140 */
8141 uint16_t nsegs;
8142 int32_t tfo_syn;
8143 struct tcp_bbr *bbr;
8144
8145 bbr = (struct tcp_bbr *)tp->t_fb_ptr;
8146 INP_WLOCK_ASSERT(tptoinpcb(tp));
8147 nsegs = max(1, m->m_pkthdr.lro_nsegs);
8148 if ((thflags & TH_ACK) &&
8149 (SEQ_LT(tp->snd_wl1, th->th_seq) ||
8150 (tp->snd_wl1 == th->th_seq && (SEQ_LT(tp->snd_wl2, th->th_ack) ||
8151 (tp->snd_wl2 == th->th_ack && tiwin > tp->snd_wnd))))) {
8152 /* keep track of pure window updates */
8153 if (tlen == 0 &&
8154 tp->snd_wl2 == th->th_ack && tiwin > tp->snd_wnd)
8155 KMOD_TCPSTAT_INC(tcps_rcvwinupd);
8156 tp->snd_wnd = tiwin;
8157 tp->snd_wl1 = th->th_seq;
8158 tp->snd_wl2 = th->th_ack;
8159 if (tp->snd_wnd > tp->max_sndwnd)
8160 tp->max_sndwnd = tp->snd_wnd;
8161 bbr->r_wanted_output = 1;
8162 } else if (thflags & TH_ACK) {
8163 if ((tp->snd_wl2 == th->th_ack) && (tiwin < tp->snd_wnd)) {
8164 tp->snd_wnd = tiwin;
8165 tp->snd_wl1 = th->th_seq;
8166 tp->snd_wl2 = th->th_ack;
8167 }
8168 }
8169 if (tp->snd_wnd < ctf_outstanding(tp))
8170 /* The peer collapsed its window on us */
8171 bbr_collapsed_window(bbr);
8172 else if (bbr->rc_has_collapsed)
8173 bbr_un_collapse_window(bbr);
8174 /* Was persist timer active and now we have window space? */
8175 if ((bbr->rc_in_persist != 0) &&
8176 (tp->snd_wnd >= min((bbr->r_ctl.rc_high_rwnd/2),
8177 bbr_minseg(bbr)))) {
8178 /*
8179 * Make the rate persist at end of persist mode if idle long
8180 * enough
8181 */
8182 bbr_exit_persist(tp, bbr, bbr->r_ctl.rc_rcvtime, __LINE__);
8183
8184 /* Make sure we output to start the timer */
8185 bbr->r_wanted_output = 1;
8186 }
8187 /* Do we need to enter persist? */
8188 if ((bbr->rc_in_persist == 0) &&
8189 (tp->snd_wnd < min((bbr->r_ctl.rc_high_rwnd/2), bbr_minseg(bbr))) &&
8190 TCPS_HAVEESTABLISHED(tp->t_state) &&
8191 (tp->snd_max == tp->snd_una) &&
8192 sbavail(&so->so_snd) &&
8193 (sbavail(&so->so_snd) > tp->snd_wnd)) {
8194 /* No send window.. we must enter persist */
8195 bbr_enter_persist(tp, bbr, bbr->r_ctl.rc_rcvtime, __LINE__);
8196 }
8197 if (tp->t_flags2 & TF2_DROP_AF_DATA) {
8198 m_freem(m);
8199 return (0);
8200 }
8201 /*
8202 * We don't support urgent data but
8203 * drag along the up just to make sure
8204 * if there is a stack switch no one
8205 * is surprised.
8206 */
8207 tp->rcv_up = tp->rcv_nxt;
8208
8209 /*
8210 * Process the segment text, merging it into the TCP sequencing
8211 * queue, and arranging for acknowledgment of receipt if necessary.
8212 * This process logically involves adjusting tp->rcv_wnd as data is
8213 * presented to the user (this happens in tcp_usrreq.c, case
8214 * PRU_RCVD). If a FIN has already been received on this connection
8215 * then we just ignore the text.
8216 */
8217 tfo_syn = ((tp->t_state == TCPS_SYN_RECEIVED) &&
8218 (tp->t_flags & TF_FASTOPEN));
8219 if ((tlen || (thflags & TH_FIN) || (tfo_syn && tlen > 0)) &&
8220 TCPS_HAVERCVDFIN(tp->t_state) == 0) {
8221 tcp_seq save_start = th->th_seq;
8222 tcp_seq save_rnxt = tp->rcv_nxt;
8223 int save_tlen = tlen;
8224
8225 m_adj(m, drop_hdrlen); /* delayed header drop */
8226 /*
8227 * Insert segment which includes th into TCP reassembly
8228 * queue with control block tp. Set thflags to whether
8229 * reassembly now includes a segment with FIN. This handles
8230 * the common case inline (segment is the next to be
8231 * received on an established connection, and the queue is
8232 * empty), avoiding linkage into and removal from the queue
8233 * and repetition of various conversions. Set DELACK for
8234 * segments received in order, but ack immediately when
8235 * segments are out of order (so fast retransmit can work).
8236 */
8237 if (th->th_seq == tp->rcv_nxt &&
8238 SEGQ_EMPTY(tp) &&
8239 (TCPS_HAVEESTABLISHED(tp->t_state) ||
8240 tfo_syn)) {
8241 #ifdef NETFLIX_SB_LIMITS
8242 u_int mcnt, appended;
8243
8244 if (so->so_rcv.sb_shlim) {
8245 mcnt = m_memcnt(m);
8246 appended = 0;
8247 if (counter_fo_get(so->so_rcv.sb_shlim, mcnt,
8248 CFO_NOSLEEP, NULL) == false) {
8249 counter_u64_add(tcp_sb_shlim_fails, 1);
8250 m_freem(m);
8251 return (0);
8252 }
8253 }
8254
8255 #endif
8256 if (DELAY_ACK(tp, bbr, nsegs) || tfo_syn) {
8257 bbr->bbr_segs_rcvd += max(1, nsegs);
8258 tp->t_flags |= TF_DELACK;
8259 bbr_timer_cancel(bbr, __LINE__, bbr->r_ctl.rc_rcvtime);
8260 } else {
8261 bbr->r_wanted_output = 1;
8262 tp->t_flags |= TF_ACKNOW;
8263 }
8264 tp->rcv_nxt += tlen;
8265 if (tlen &&
8266 ((tp->t_flags2 & TF2_FBYTES_COMPLETE) == 0) &&
8267 (tp->t_fbyte_in == 0)) {
8268 tp->t_fbyte_in = ticks;
8269 if (tp->t_fbyte_in == 0)
8270 tp->t_fbyte_in = 1;
8271 if (tp->t_fbyte_out && tp->t_fbyte_in)
8272 tp->t_flags2 |= TF2_FBYTES_COMPLETE;
8273 }
8274 thflags = tcp_get_flags(th) & TH_FIN;
8275 KMOD_TCPSTAT_ADD(tcps_rcvpack, (int)nsegs);
8276 KMOD_TCPSTAT_ADD(tcps_rcvbyte, tlen);
8277 SOCK_RECVBUF_LOCK(so);
8278 if (so->so_rcv.sb_state & SBS_CANTRCVMORE)
8279 m_freem(m);
8280 else
8281 #ifdef NETFLIX_SB_LIMITS
8282 appended =
8283 #endif
8284 sbappendstream_locked(&so->so_rcv, m, 0);
8285 /* NB: sorwakeup_locked() does an implicit unlock. */
8286 sorwakeup_locked(so);
8287 #ifdef NETFLIX_SB_LIMITS
8288 if (so->so_rcv.sb_shlim && appended != mcnt)
8289 counter_fo_release(so->so_rcv.sb_shlim,
8290 mcnt - appended);
8291 #endif
8292
8293 } else {
8294 /*
8295 * XXX: Due to the header drop above "th" is
8296 * theoretically invalid by now. Fortunately
8297 * m_adj() doesn't actually frees any mbufs when
8298 * trimming from the head.
8299 */
8300 tcp_seq temp = save_start;
8301
8302 thflags = tcp_reass(tp, th, &temp, &tlen, m);
8303 tp->t_flags |= TF_ACKNOW;
8304 if (tp->t_flags & TF_WAKESOR) {
8305 tp->t_flags &= ~TF_WAKESOR;
8306 /* NB: sorwakeup_locked() does an implicit unlock. */
8307 sorwakeup_locked(so);
8308 }
8309 }
8310 if ((tp->t_flags & TF_SACK_PERMIT) &&
8311 (save_tlen > 0) &&
8312 TCPS_HAVEESTABLISHED(tp->t_state)) {
8313 if ((tlen == 0) && (SEQ_LT(save_start, save_rnxt))) {
8314 /*
8315 * DSACK actually handled in the fastpath
8316 * above.
8317 */
8318 tcp_update_sack_list(tp, save_start,
8319 save_start + save_tlen);
8320 } else if ((tlen > 0) && SEQ_GT(tp->rcv_nxt, save_rnxt)) {
8321 if ((tp->rcv_numsacks >= 1) &&
8322 (tp->sackblks[0].end == save_start)) {
8323 /*
8324 * Partial overlap, recorded at todrop
8325 * above.
8326 */
8327 tcp_update_sack_list(tp,
8328 tp->sackblks[0].start,
8329 tp->sackblks[0].end);
8330 } else {
8331 tcp_update_dsack_list(tp, save_start,
8332 save_start + save_tlen);
8333 }
8334 } else if (tlen >= save_tlen) {
8335 /* Update of sackblks. */
8336 tcp_update_dsack_list(tp, save_start,
8337 save_start + save_tlen);
8338 } else if (tlen > 0) {
8339 tcp_update_dsack_list(tp, save_start,
8340 save_start + tlen);
8341 }
8342 }
8343 } else {
8344 m_freem(m);
8345 thflags &= ~TH_FIN;
8346 }
8347
8348 /*
8349 * If FIN is received ACK the FIN and let the user know that the
8350 * connection is closing.
8351 */
8352 if (thflags & TH_FIN) {
8353 if (TCPS_HAVERCVDFIN(tp->t_state) == 0) {
8354 /* The socket upcall is handled by socantrcvmore. */
8355 socantrcvmore(so);
8356 /*
8357 * If connection is half-synchronized (ie NEEDSYN
8358 * flag on) then delay ACK, so it may be piggybacked
8359 * when SYN is sent. Otherwise, since we received a
8360 * FIN then no more input can be expected, send ACK
8361 * now.
8362 */
8363 if (tp->t_flags & TF_NEEDSYN) {
8364 tp->t_flags |= TF_DELACK;
8365 bbr_timer_cancel(bbr,
8366 __LINE__, bbr->r_ctl.rc_rcvtime);
8367 } else {
8368 tp->t_flags |= TF_ACKNOW;
8369 }
8370 tp->rcv_nxt++;
8371 }
8372 switch (tp->t_state) {
8373 /*
8374 * In SYN_RECEIVED and ESTABLISHED STATES enter the
8375 * CLOSE_WAIT state.
8376 */
8377 case TCPS_SYN_RECEIVED:
8378 tp->t_starttime = ticks;
8379 /* FALLTHROUGH */
8380 case TCPS_ESTABLISHED:
8381 tcp_state_change(tp, TCPS_CLOSE_WAIT);
8382 break;
8383
8384 /*
8385 * If still in FIN_WAIT_1 STATE FIN has not been
8386 * acked so enter the CLOSING state.
8387 */
8388 case TCPS_FIN_WAIT_1:
8389 tcp_state_change(tp, TCPS_CLOSING);
8390 break;
8391
8392 /*
8393 * In FIN_WAIT_2 state enter the TIME_WAIT state,
8394 * starting the time-wait timer, turning off the
8395 * other standard timers.
8396 */
8397 case TCPS_FIN_WAIT_2:
8398 bbr->rc_timer_first = 1;
8399 bbr_timer_cancel(bbr,
8400 __LINE__, bbr->r_ctl.rc_rcvtime);
8401 tcp_twstart(tp);
8402 return (1);
8403 }
8404 }
8405 /*
8406 * Return any desired output.
8407 */
8408 if ((tp->t_flags & TF_ACKNOW) ||
8409 (sbavail(&so->so_snd) > ctf_outstanding(tp))) {
8410 bbr->r_wanted_output = 1;
8411 }
8412 return (0);
8413 }
8414
8415 /*
8416 * Here nothing is really faster, its just that we
8417 * have broken out the fast-data path also just like
8418 * the fast-ack. Return 1 if we processed the packet
8419 * return 0 if you need to take the "slow-path".
8420 */
8421 static int
bbr_do_fastnewdata(struct mbuf * m,struct tcphdr * th,struct socket * so,struct tcpcb * tp,struct tcpopt * to,int32_t drop_hdrlen,int32_t tlen,uint32_t tiwin,int32_t nxt_pkt)8422 bbr_do_fastnewdata(struct mbuf *m, struct tcphdr *th, struct socket *so,
8423 struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen,
8424 uint32_t tiwin, int32_t nxt_pkt)
8425 {
8426 uint16_t nsegs;
8427 int32_t newsize = 0; /* automatic sockbuf scaling */
8428 struct tcp_bbr *bbr;
8429 #ifdef NETFLIX_SB_LIMITS
8430 u_int mcnt, appended;
8431 #endif
8432
8433 /* On the hpts and we would have called output */
8434 bbr = (struct tcp_bbr *)tp->t_fb_ptr;
8435
8436 /*
8437 * If last ACK falls within this segment's sequence numbers, record
8438 * the timestamp. NOTE that the test is modified according to the
8439 * latest proposal of the tcplw@cray.com list (Braden 1993/04/26).
8440 */
8441 if (bbr->r_ctl.rc_resend != NULL) {
8442 return (0);
8443 }
8444 if (tiwin && tiwin != tp->snd_wnd) {
8445 return (0);
8446 }
8447 if (__predict_false((tp->t_flags & (TF_NEEDSYN | TF_NEEDFIN)))) {
8448 return (0);
8449 }
8450 if (__predict_false((to->to_flags & TOF_TS) &&
8451 (TSTMP_LT(to->to_tsval, tp->ts_recent)))) {
8452 return (0);
8453 }
8454 if (__predict_false((th->th_ack != tp->snd_una))) {
8455 return (0);
8456 }
8457 if (__predict_false(tlen > sbspace(&so->so_rcv))) {
8458 return (0);
8459 }
8460 if ((to->to_flags & TOF_TS) != 0 &&
8461 SEQ_LEQ(th->th_seq, tp->last_ack_sent)) {
8462 tp->ts_recent_age = tcp_tv_to_msec(&bbr->rc_tv);
8463 tp->ts_recent = to->to_tsval;
8464 }
8465 /*
8466 * This is a pure, in-sequence data packet with nothing on the
8467 * reassembly queue and we have enough buffer space to take it.
8468 */
8469 nsegs = max(1, m->m_pkthdr.lro_nsegs);
8470
8471 #ifdef NETFLIX_SB_LIMITS
8472 if (so->so_rcv.sb_shlim) {
8473 mcnt = m_memcnt(m);
8474 appended = 0;
8475 if (counter_fo_get(so->so_rcv.sb_shlim, mcnt,
8476 CFO_NOSLEEP, NULL) == false) {
8477 counter_u64_add(tcp_sb_shlim_fails, 1);
8478 m_freem(m);
8479 return (1);
8480 }
8481 }
8482 #endif
8483 /* Clean receiver SACK report if present */
8484 if (tp->rcv_numsacks)
8485 tcp_clean_sackreport(tp);
8486 KMOD_TCPSTAT_INC(tcps_preddat);
8487 tp->rcv_nxt += tlen;
8488 if (tlen &&
8489 ((tp->t_flags2 & TF2_FBYTES_COMPLETE) == 0) &&
8490 (tp->t_fbyte_in == 0)) {
8491 tp->t_fbyte_in = ticks;
8492 if (tp->t_fbyte_in == 0)
8493 tp->t_fbyte_in = 1;
8494 if (tp->t_fbyte_out && tp->t_fbyte_in)
8495 tp->t_flags2 |= TF2_FBYTES_COMPLETE;
8496 }
8497 /*
8498 * Pull snd_wl1 up to prevent seq wrap relative to th_seq.
8499 */
8500 tp->snd_wl1 = th->th_seq;
8501 /*
8502 * Pull rcv_up up to prevent seq wrap relative to rcv_nxt.
8503 */
8504 tp->rcv_up = tp->rcv_nxt;
8505 KMOD_TCPSTAT_ADD(tcps_rcvpack, (int)nsegs);
8506 KMOD_TCPSTAT_ADD(tcps_rcvbyte, tlen);
8507 newsize = tcp_autorcvbuf(m, th, so, tp, tlen);
8508
8509 /* Add data to socket buffer. */
8510 SOCK_RECVBUF_LOCK(so);
8511 if (so->so_rcv.sb_state & SBS_CANTRCVMORE) {
8512 m_freem(m);
8513 } else {
8514 /*
8515 * Set new socket buffer size. Give up when limit is
8516 * reached.
8517 */
8518 if (newsize)
8519 if (!sbreserve_locked(so, SO_RCV, newsize, NULL))
8520 so->so_rcv.sb_flags &= ~SB_AUTOSIZE;
8521 m_adj(m, drop_hdrlen); /* delayed header drop */
8522
8523 #ifdef NETFLIX_SB_LIMITS
8524 appended =
8525 #endif
8526 sbappendstream_locked(&so->so_rcv, m, 0);
8527 ctf_calc_rwin(so, tp);
8528 }
8529 /* NB: sorwakeup_locked() does an implicit unlock. */
8530 sorwakeup_locked(so);
8531 #ifdef NETFLIX_SB_LIMITS
8532 if (so->so_rcv.sb_shlim && mcnt != appended)
8533 counter_fo_release(so->so_rcv.sb_shlim, mcnt - appended);
8534 #endif
8535 if (DELAY_ACK(tp, bbr, nsegs)) {
8536 bbr->bbr_segs_rcvd += max(1, nsegs);
8537 tp->t_flags |= TF_DELACK;
8538 bbr_timer_cancel(bbr, __LINE__, bbr->r_ctl.rc_rcvtime);
8539 } else {
8540 bbr->r_wanted_output = 1;
8541 tp->t_flags |= TF_ACKNOW;
8542 }
8543 return (1);
8544 }
8545
8546 /*
8547 * This subfunction is used to try to highly optimize the
8548 * fast path. We again allow window updates that are
8549 * in sequence to remain in the fast-path. We also add
8550 * in the __predict's to attempt to help the compiler.
8551 * Note that if we return a 0, then we can *not* process
8552 * it and the caller should push the packet into the
8553 * slow-path. If we return 1, then all is well and
8554 * the packet is fully processed.
8555 */
8556 static int
bbr_fastack(struct mbuf * m,struct tcphdr * th,struct socket * so,struct tcpcb * tp,struct tcpopt * to,int32_t drop_hdrlen,int32_t tlen,uint32_t tiwin,int32_t nxt_pkt,uint8_t iptos)8557 bbr_fastack(struct mbuf *m, struct tcphdr *th, struct socket *so,
8558 struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen,
8559 uint32_t tiwin, int32_t nxt_pkt, uint8_t iptos)
8560 {
8561 int32_t acked;
8562 uint16_t nsegs;
8563 uint32_t sack_changed;
8564 uint32_t prev_acked = 0;
8565 struct tcp_bbr *bbr;
8566
8567 if (__predict_false(SEQ_LEQ(th->th_ack, tp->snd_una))) {
8568 /* Old ack, behind (or duplicate to) the last one rcv'd */
8569 return (0);
8570 }
8571 if (__predict_false(SEQ_GT(th->th_ack, tp->snd_max))) {
8572 /* Above what we have sent? */
8573 return (0);
8574 }
8575 if (__predict_false(tiwin == 0)) {
8576 /* zero window */
8577 return (0);
8578 }
8579 if (__predict_false(tp->t_flags & (TF_NEEDSYN | TF_NEEDFIN))) {
8580 /* We need a SYN or a FIN, unlikely.. */
8581 return (0);
8582 }
8583 if ((to->to_flags & TOF_TS) && __predict_false(TSTMP_LT(to->to_tsval, tp->ts_recent))) {
8584 /* Timestamp is behind .. old ack with seq wrap? */
8585 return (0);
8586 }
8587 if (__predict_false(IN_RECOVERY(tp->t_flags))) {
8588 /* Still recovering */
8589 return (0);
8590 }
8591 bbr = (struct tcp_bbr *)tp->t_fb_ptr;
8592 if (__predict_false(bbr->r_ctl.rc_resend != NULL)) {
8593 /* We are retransmitting */
8594 return (0);
8595 }
8596 if (__predict_false(bbr->rc_in_persist != 0)) {
8597 /* In persist mode */
8598 return (0);
8599 }
8600 if (bbr->r_ctl.rc_sacked) {
8601 /* We have sack holes on our scoreboard */
8602 return (0);
8603 }
8604 /* Ok if we reach here, we can process a fast-ack */
8605 nsegs = max(1, m->m_pkthdr.lro_nsegs);
8606 sack_changed = bbr_log_ack(tp, to, th, &prev_acked);
8607 /*
8608 * We never detect loss in fast ack [we can't
8609 * have a sack and can't be in recovery so
8610 * we always pass 0 (nothing detected)].
8611 */
8612 bbr_lt_bw_sampling(bbr, bbr->r_ctl.rc_rcvtime, 0);
8613 /* Did the window get updated? */
8614 if (tiwin != tp->snd_wnd) {
8615 tp->snd_wnd = tiwin;
8616 tp->snd_wl1 = th->th_seq;
8617 if (tp->snd_wnd > tp->max_sndwnd)
8618 tp->max_sndwnd = tp->snd_wnd;
8619 }
8620 /* Do we need to exit persists? */
8621 if ((bbr->rc_in_persist != 0) &&
8622 (tp->snd_wnd >= min((bbr->r_ctl.rc_high_rwnd/2),
8623 bbr_minseg(bbr)))) {
8624 bbr_exit_persist(tp, bbr, bbr->r_ctl.rc_rcvtime, __LINE__);
8625 bbr->r_wanted_output = 1;
8626 }
8627 /* Do we need to enter persists? */
8628 if ((bbr->rc_in_persist == 0) &&
8629 (tp->snd_wnd < min((bbr->r_ctl.rc_high_rwnd/2), bbr_minseg(bbr))) &&
8630 TCPS_HAVEESTABLISHED(tp->t_state) &&
8631 (tp->snd_max == tp->snd_una) &&
8632 sbavail(&so->so_snd) &&
8633 (sbavail(&so->so_snd) > tp->snd_wnd)) {
8634 /* No send window.. we must enter persist */
8635 bbr_enter_persist(tp, bbr, bbr->r_ctl.rc_rcvtime, __LINE__);
8636 }
8637 /*
8638 * If last ACK falls within this segment's sequence numbers, record
8639 * the timestamp. NOTE that the test is modified according to the
8640 * latest proposal of the tcplw@cray.com list (Braden 1993/04/26).
8641 */
8642 if ((to->to_flags & TOF_TS) != 0 &&
8643 SEQ_LEQ(th->th_seq, tp->last_ack_sent)) {
8644 tp->ts_recent_age = bbr->r_ctl.rc_rcvtime;
8645 tp->ts_recent = to->to_tsval;
8646 }
8647 /*
8648 * This is a pure ack for outstanding data.
8649 */
8650 KMOD_TCPSTAT_INC(tcps_predack);
8651
8652 /*
8653 * "bad retransmit" recovery.
8654 */
8655 if (tp->t_flags & TF_PREVVALID) {
8656 tp->t_flags &= ~TF_PREVVALID;
8657 if (tp->t_rxtshift == 1 &&
8658 (int)(ticks - tp->t_badrxtwin) < 0)
8659 bbr_cong_signal(tp, th, CC_RTO_ERR, NULL);
8660 }
8661 /*
8662 * Recalculate the transmit timer / rtt.
8663 *
8664 * Some boxes send broken timestamp replies during the SYN+ACK
8665 * phase, ignore timestamps of 0 or we could calculate a huge RTT
8666 * and blow up the retransmit timer.
8667 */
8668 acked = BYTES_THIS_ACK(tp, th);
8669
8670 #ifdef TCP_HHOOK
8671 /* Run HHOOK_TCP_ESTABLISHED_IN helper hooks. */
8672 hhook_run_tcp_est_in(tp, th, to);
8673 #endif
8674
8675 KMOD_TCPSTAT_ADD(tcps_rcvackpack, (int)nsegs);
8676 KMOD_TCPSTAT_ADD(tcps_rcvackbyte, acked);
8677 sbdrop(&so->so_snd, acked);
8678
8679 if (SEQ_GT(th->th_ack, tp->snd_una))
8680 bbr_collapse_rtt(tp, bbr, TCP_REXMTVAL(tp));
8681 tp->snd_una = th->th_ack;
8682 if (tp->snd_wnd < ctf_outstanding(tp))
8683 /* The peer collapsed its window on us */
8684 bbr_collapsed_window(bbr);
8685 else if (bbr->rc_has_collapsed)
8686 bbr_un_collapse_window(bbr);
8687
8688 if (SEQ_GT(tp->snd_una, tp->snd_recover)) {
8689 tp->snd_recover = tp->snd_una;
8690 }
8691 bbr_ack_received(tp, bbr, th, acked, sack_changed, prev_acked, __LINE__, 0);
8692 /*
8693 * Pull snd_wl2 up to prevent seq wrap relative to th_ack.
8694 */
8695 tp->snd_wl2 = th->th_ack;
8696 m_freem(m);
8697 /*
8698 * If all outstanding data are acked, stop retransmit timer,
8699 * otherwise restart timer using current (possibly backed-off)
8700 * value. If process is waiting for space, wakeup/selwakeup/signal.
8701 * If data are ready to send, let tcp_output decide between more
8702 * output or persist.
8703 * Wake up the socket if we have room to write more.
8704 */
8705 sowwakeup(so);
8706 if (tp->snd_una == tp->snd_max) {
8707 /* Nothing left outstanding */
8708 bbr_log_progress_event(bbr, tp, ticks, PROGRESS_CLEAR, __LINE__);
8709 if (sbavail(&so->so_snd) == 0)
8710 bbr->rc_tp->t_acktime = 0;
8711 bbr_timer_cancel(bbr, __LINE__, bbr->r_ctl.rc_rcvtime);
8712 if (bbr->rc_in_persist == 0) {
8713 bbr->r_ctl.rc_went_idle_time = bbr->r_ctl.rc_rcvtime;
8714 }
8715 sack_filter_clear(&bbr->r_ctl.bbr_sf, tp->snd_una);
8716 bbr_log_ack_clear(bbr, bbr->r_ctl.rc_rcvtime);
8717 /*
8718 * We invalidate the last ack here since we
8719 * don't want to transfer forward the time
8720 * for our sum's calculations.
8721 */
8722 bbr->r_wanted_output = 1;
8723 }
8724 if (sbavail(&so->so_snd)) {
8725 bbr->r_wanted_output = 1;
8726 }
8727 return (1);
8728 }
8729
8730 /*
8731 * Return value of 1, the TCB is unlocked and most
8732 * likely gone, return value of 0, the TCB is still
8733 * locked.
8734 */
8735 static int
bbr_do_syn_sent(struct mbuf * m,struct tcphdr * th,struct socket * so,struct tcpcb * tp,struct tcpopt * to,int32_t drop_hdrlen,int32_t tlen,uint32_t tiwin,int32_t thflags,int32_t nxt_pkt,uint8_t iptos)8736 bbr_do_syn_sent(struct mbuf *m, struct tcphdr *th, struct socket *so,
8737 struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen,
8738 uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos)
8739 {
8740 int32_t todrop;
8741 int32_t ourfinisacked = 0;
8742 struct tcp_bbr *bbr;
8743 int32_t ret_val = 0;
8744
8745 INP_WLOCK_ASSERT(tptoinpcb(tp));
8746
8747 bbr = (struct tcp_bbr *)tp->t_fb_ptr;
8748 ctf_calc_rwin(so, tp);
8749 /*
8750 * If the state is SYN_SENT: if seg contains an ACK, but not for our
8751 * SYN, drop the input. if seg contains a RST, then drop the
8752 * connection. if seg does not contain SYN, then drop it. Otherwise
8753 * this is an acceptable SYN segment initialize tp->rcv_nxt and
8754 * tp->irs if seg contains ack then advance tp->snd_una. BRR does
8755 * not support ECN so we will not say we are capable. if SYN has
8756 * been acked change to ESTABLISHED else SYN_RCVD state arrange for
8757 * segment to be acked (eventually) continue processing rest of
8758 * data/controls, beginning with URG
8759 */
8760 if ((thflags & TH_ACK) &&
8761 (SEQ_LEQ(th->th_ack, tp->iss) ||
8762 SEQ_GT(th->th_ack, tp->snd_max))) {
8763 tcp_log_end_status(tp, TCP_EI_STATUS_RST_IN_FRONT);
8764 ctf_do_dropwithreset(m, tp, th, tlen);
8765 return (1);
8766 }
8767 if ((thflags & (TH_ACK | TH_RST)) == (TH_ACK | TH_RST)) {
8768 TCP_PROBE5(connect__refused, NULL, tp,
8769 mtod(m, const char *), tp, th);
8770 tp = tcp_drop(tp, ECONNREFUSED);
8771 ctf_do_drop(m, tp);
8772 return (1);
8773 }
8774 if (thflags & TH_RST) {
8775 ctf_do_drop(m, tp);
8776 return (1);
8777 }
8778 if (!(thflags & TH_SYN)) {
8779 ctf_do_drop(m, tp);
8780 return (1);
8781 }
8782 tp->irs = th->th_seq;
8783 tcp_rcvseqinit(tp);
8784 if (thflags & TH_ACK) {
8785 int tfo_partial = 0;
8786
8787 KMOD_TCPSTAT_INC(tcps_connects);
8788 soisconnected(so);
8789 #ifdef MAC
8790 mac_socketpeer_set_from_mbuf(m, so);
8791 #endif
8792 /* Do window scaling on this connection? */
8793 if ((tp->t_flags & (TF_RCVD_SCALE | TF_REQ_SCALE)) ==
8794 (TF_RCVD_SCALE | TF_REQ_SCALE)) {
8795 tp->rcv_scale = tp->request_r_scale;
8796 }
8797 tp->rcv_adv += min(tp->rcv_wnd,
8798 TCP_MAXWIN << tp->rcv_scale);
8799 /*
8800 * If not all the data that was sent in the TFO SYN
8801 * has been acked, resend the remainder right away.
8802 */
8803 if ((tp->t_flags & TF_FASTOPEN) &&
8804 (tp->snd_una != tp->snd_max)) {
8805 tp->snd_nxt = th->th_ack;
8806 tfo_partial = 1;
8807 }
8808 /*
8809 * If there's data, delay ACK; if there's also a FIN ACKNOW
8810 * will be turned on later.
8811 */
8812 if (DELAY_ACK(tp, bbr, 1) && tlen != 0 && !tfo_partial) {
8813 bbr->bbr_segs_rcvd += 1;
8814 tp->t_flags |= TF_DELACK;
8815 bbr_timer_cancel(bbr, __LINE__, bbr->r_ctl.rc_rcvtime);
8816 } else {
8817 bbr->r_wanted_output = 1;
8818 tp->t_flags |= TF_ACKNOW;
8819 }
8820 if (SEQ_GT(th->th_ack, tp->iss)) {
8821 /*
8822 * The SYN is acked
8823 * handle it specially.
8824 */
8825 bbr_log_syn(tp, to);
8826 }
8827 if (SEQ_GT(th->th_ack, tp->snd_una)) {
8828 /*
8829 * We advance snd_una for the
8830 * fast open case. If th_ack is
8831 * acknowledging data beyond
8832 * snd_una we can't just call
8833 * ack-processing since the
8834 * data stream in our send-map
8835 * will start at snd_una + 1 (one
8836 * beyond the SYN). If its just
8837 * equal we don't need to do that
8838 * and there is no send_map.
8839 */
8840 tp->snd_una++;
8841 }
8842 /*
8843 * Received <SYN,ACK> in SYN_SENT[*] state. Transitions:
8844 * SYN_SENT --> ESTABLISHED SYN_SENT* --> FIN_WAIT_1
8845 */
8846 tp->t_starttime = ticks;
8847 if (tp->t_flags & TF_NEEDFIN) {
8848 tcp_state_change(tp, TCPS_FIN_WAIT_1);
8849 tp->t_flags &= ~TF_NEEDFIN;
8850 thflags &= ~TH_SYN;
8851 } else {
8852 tcp_state_change(tp, TCPS_ESTABLISHED);
8853 TCP_PROBE5(connect__established, NULL, tp,
8854 mtod(m, const char *), tp, th);
8855 cc_conn_init(tp);
8856 }
8857 } else {
8858 /*
8859 * Received initial SYN in SYN-SENT[*] state => simultaneous
8860 * open. If segment contains CC option and there is a
8861 * cached CC, apply TAO test. If it succeeds, connection is *
8862 * half-synchronized. Otherwise, do 3-way handshake:
8863 * SYN-SENT -> SYN-RECEIVED SYN-SENT* -> SYN-RECEIVED* If
8864 * there was no CC option, clear cached CC value.
8865 */
8866 tp->t_flags |= (TF_ACKNOW | TF_NEEDSYN | TF_SONOTCONN);
8867 tcp_state_change(tp, TCPS_SYN_RECEIVED);
8868 }
8869 /*
8870 * Advance th->th_seq to correspond to first data byte. If data,
8871 * trim to stay within window, dropping FIN if necessary.
8872 */
8873 th->th_seq++;
8874 if (tlen > tp->rcv_wnd) {
8875 todrop = tlen - tp->rcv_wnd;
8876 m_adj(m, -todrop);
8877 tlen = tp->rcv_wnd;
8878 thflags &= ~TH_FIN;
8879 KMOD_TCPSTAT_INC(tcps_rcvpackafterwin);
8880 KMOD_TCPSTAT_ADD(tcps_rcvbyteafterwin, todrop);
8881 }
8882 tp->snd_wl1 = th->th_seq - 1;
8883 tp->rcv_up = th->th_seq;
8884 /*
8885 * Client side of transaction: already sent SYN and data. If the
8886 * remote host used T/TCP to validate the SYN, our data will be
8887 * ACK'd; if so, enter normal data segment processing in the middle
8888 * of step 5, ack processing. Otherwise, goto step 6.
8889 */
8890 if (thflags & TH_ACK) {
8891 if ((to->to_flags & TOF_TS) != 0) {
8892 uint32_t t, rtt;
8893
8894 t = tcp_tv_to_msec(&bbr->rc_tv);
8895 if (TSTMP_GEQ(t, to->to_tsecr)) {
8896 rtt = t - to->to_tsecr;
8897 if (rtt == 0) {
8898 rtt = 1;
8899 }
8900 rtt *= MS_IN_USEC;
8901 tcp_bbr_xmit_timer(bbr, rtt, 0, 0, 0);
8902 apply_filter_min_small(&bbr->r_ctl.rc_rttprop,
8903 rtt, bbr->r_ctl.rc_rcvtime);
8904 }
8905 }
8906 if (bbr_process_ack(m, th, so, tp, to, tiwin, tlen, &ourfinisacked, thflags, &ret_val))
8907 return (ret_val);
8908 /* We may have changed to FIN_WAIT_1 above */
8909 if (tp->t_state == TCPS_FIN_WAIT_1) {
8910 /*
8911 * In FIN_WAIT_1 STATE in addition to the processing
8912 * for the ESTABLISHED state if our FIN is now
8913 * acknowledged then enter FIN_WAIT_2.
8914 */
8915 if (ourfinisacked) {
8916 /*
8917 * If we can't receive any more data, then
8918 * closing user can proceed. Starting the
8919 * timer is contrary to the specification,
8920 * but if we don't get a FIN we'll hang
8921 * forever.
8922 *
8923 * XXXjl: we should release the tp also, and
8924 * use a compressed state.
8925 */
8926 if (so->so_rcv.sb_state & SBS_CANTRCVMORE) {
8927 soisdisconnected(so);
8928 tcp_timer_activate(tp, TT_2MSL,
8929 (tcp_fast_finwait2_recycle ?
8930 tcp_finwait2_timeout :
8931 TP_MAXIDLE(tp)));
8932 }
8933 tcp_state_change(tp, TCPS_FIN_WAIT_2);
8934 }
8935 }
8936 }
8937 return (bbr_process_data(m, th, so, tp, drop_hdrlen, tlen,
8938 tiwin, thflags, nxt_pkt));
8939 }
8940
8941 /*
8942 * Return value of 1, the TCB is unlocked and most
8943 * likely gone, return value of 0, the TCB is still
8944 * locked.
8945 */
8946 static int
bbr_do_syn_recv(struct mbuf * m,struct tcphdr * th,struct socket * so,struct tcpcb * tp,struct tcpopt * to,int32_t drop_hdrlen,int32_t tlen,uint32_t tiwin,int32_t thflags,int32_t nxt_pkt,uint8_t iptos)8947 bbr_do_syn_recv(struct mbuf *m, struct tcphdr *th, struct socket *so,
8948 struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen,
8949 uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos)
8950 {
8951 int32_t ourfinisacked = 0;
8952 int32_t ret_val;
8953 struct tcp_bbr *bbr;
8954
8955 INP_WLOCK_ASSERT(tptoinpcb(tp));
8956
8957 bbr = (struct tcp_bbr *)tp->t_fb_ptr;
8958 ctf_calc_rwin(so, tp);
8959 if ((thflags & TH_RST) ||
8960 (tp->t_fin_is_rst && (thflags & TH_FIN)))
8961 return (ctf_process_rst(m, th, so, tp));
8962 if ((thflags & TH_ACK) &&
8963 (SEQ_LEQ(th->th_ack, tp->snd_una) ||
8964 SEQ_GT(th->th_ack, tp->snd_max))) {
8965 tcp_log_end_status(tp, TCP_EI_STATUS_RST_IN_FRONT);
8966 ctf_do_dropwithreset(m, tp, th, tlen);
8967 return (1);
8968 }
8969 if (tp->t_flags & TF_FASTOPEN) {
8970 /*
8971 * When a TFO connection is in SYN_RECEIVED, the only valid
8972 * packets are the initial SYN, a retransmit/copy of the
8973 * initial SYN (possibly with a subset of the original
8974 * data), a valid ACK, a FIN, or a RST.
8975 */
8976 if ((thflags & (TH_SYN | TH_ACK)) == (TH_SYN | TH_ACK)) {
8977 tcp_log_end_status(tp, TCP_EI_STATUS_RST_IN_FRONT);
8978 ctf_do_dropwithreset(m, tp, th, tlen);
8979 return (1);
8980 } else if (thflags & TH_SYN) {
8981 /* non-initial SYN is ignored */
8982 if ((bbr->r_ctl.rc_hpts_flags & PACE_TMR_RXT) ||
8983 (bbr->r_ctl.rc_hpts_flags & PACE_TMR_TLP) ||
8984 (bbr->r_ctl.rc_hpts_flags & PACE_TMR_RACK)) {
8985 ctf_do_drop(m, NULL);
8986 return (0);
8987 }
8988 } else if (!(thflags & (TH_ACK | TH_FIN | TH_RST))) {
8989 ctf_do_drop(m, NULL);
8990 return (0);
8991 }
8992 }
8993 /*
8994 * RFC 1323 PAWS: If we have a timestamp reply on this segment and
8995 * it's less than ts_recent, drop it.
8996 */
8997 if ((to->to_flags & TOF_TS) != 0 && tp->ts_recent &&
8998 TSTMP_LT(to->to_tsval, tp->ts_recent)) {
8999 if (ctf_ts_check(m, th, tp, tlen, thflags, &ret_val))
9000 return (ret_val);
9001 }
9002 /*
9003 * In the SYN-RECEIVED state, validate that the packet belongs to
9004 * this connection before trimming the data to fit the receive
9005 * window. Check the sequence number versus IRS since we know the
9006 * sequence numbers haven't wrapped. This is a partial fix for the
9007 * "LAND" DoS attack.
9008 */
9009 if (SEQ_LT(th->th_seq, tp->irs)) {
9010 tcp_log_end_status(tp, TCP_EI_STATUS_RST_IN_FRONT);
9011 ctf_do_dropwithreset(m, tp, th, tlen);
9012 return (1);
9013 }
9014 if (ctf_drop_checks(to, m, th, tp, &tlen, &thflags, &drop_hdrlen, &ret_val)) {
9015 return (ret_val);
9016 }
9017 /*
9018 * If last ACK falls within this segment's sequence numbers, record
9019 * its timestamp. NOTE: 1) That the test incorporates suggestions
9020 * from the latest proposal of the tcplw@cray.com list (Braden
9021 * 1993/04/26). 2) That updating only on newer timestamps interferes
9022 * with our earlier PAWS tests, so this check should be solely
9023 * predicated on the sequence space of this segment. 3) That we
9024 * modify the segment boundary check to be Last.ACK.Sent <= SEG.SEQ
9025 * + SEG.Len instead of RFC1323's Last.ACK.Sent < SEG.SEQ +
9026 * SEG.Len, This modified check allows us to overcome RFC1323's
9027 * limitations as described in Stevens TCP/IP Illustrated Vol. 2
9028 * p.869. In such cases, we can still calculate the RTT correctly
9029 * when RCV.NXT == Last.ACK.Sent.
9030 */
9031 if ((to->to_flags & TOF_TS) != 0 &&
9032 SEQ_LEQ(th->th_seq, tp->last_ack_sent) &&
9033 SEQ_LEQ(tp->last_ack_sent, th->th_seq + tlen +
9034 ((thflags & (TH_SYN | TH_FIN)) != 0))) {
9035 tp->ts_recent_age = tcp_tv_to_msec(&bbr->rc_tv);
9036 tp->ts_recent = to->to_tsval;
9037 }
9038 tp->snd_wnd = tiwin;
9039 /*
9040 * If the ACK bit is off: if in SYN-RECEIVED state or SENDSYN flag
9041 * is on (half-synchronized state), then queue data for later
9042 * processing; else drop segment and return.
9043 */
9044 if ((thflags & TH_ACK) == 0) {
9045 if (tp->t_flags & TF_FASTOPEN) {
9046 cc_conn_init(tp);
9047 }
9048 return (bbr_process_data(m, th, so, tp, drop_hdrlen, tlen,
9049 tiwin, thflags, nxt_pkt));
9050 }
9051 KMOD_TCPSTAT_INC(tcps_connects);
9052 if (tp->t_flags & TF_SONOTCONN) {
9053 tp->t_flags &= ~TF_SONOTCONN;
9054 soisconnected(so);
9055 }
9056 /* Do window scaling? */
9057 if ((tp->t_flags & (TF_RCVD_SCALE | TF_REQ_SCALE)) ==
9058 (TF_RCVD_SCALE | TF_REQ_SCALE)) {
9059 tp->rcv_scale = tp->request_r_scale;
9060 }
9061 /*
9062 * ok for the first time in lets see if we can use the ts to figure
9063 * out what the initial RTT was.
9064 */
9065 if ((to->to_flags & TOF_TS) != 0) {
9066 uint32_t t, rtt;
9067
9068 t = tcp_tv_to_msec(&bbr->rc_tv);
9069 if (TSTMP_GEQ(t, to->to_tsecr)) {
9070 rtt = t - to->to_tsecr;
9071 if (rtt == 0) {
9072 rtt = 1;
9073 }
9074 rtt *= MS_IN_USEC;
9075 tcp_bbr_xmit_timer(bbr, rtt, 0, 0, 0);
9076 apply_filter_min_small(&bbr->r_ctl.rc_rttprop, rtt, bbr->r_ctl.rc_rcvtime);
9077 }
9078 }
9079 /* Drop off any SYN in the send map (probably not there) */
9080 if (thflags & TH_ACK)
9081 bbr_log_syn(tp, to);
9082 if ((tp->t_flags & TF_FASTOPEN) && tp->t_tfo_pending) {
9083 tcp_fastopen_decrement_counter(tp->t_tfo_pending);
9084 tp->t_tfo_pending = NULL;
9085 }
9086 /*
9087 * Make transitions: SYN-RECEIVED -> ESTABLISHED SYN-RECEIVED* ->
9088 * FIN-WAIT-1
9089 */
9090 tp->t_starttime = ticks;
9091 if (tp->t_flags & TF_NEEDFIN) {
9092 tcp_state_change(tp, TCPS_FIN_WAIT_1);
9093 tp->t_flags &= ~TF_NEEDFIN;
9094 } else {
9095 tcp_state_change(tp, TCPS_ESTABLISHED);
9096 TCP_PROBE5(accept__established, NULL, tp,
9097 mtod(m, const char *), tp, th);
9098 /*
9099 * TFO connections call cc_conn_init() during SYN
9100 * processing. Calling it again here for such connections
9101 * is not harmless as it would undo the snd_cwnd reduction
9102 * that occurs when a TFO SYN|ACK is retransmitted.
9103 */
9104 if (!(tp->t_flags & TF_FASTOPEN))
9105 cc_conn_init(tp);
9106 }
9107 /*
9108 * Account for the ACK of our SYN prior to
9109 * regular ACK processing below, except for
9110 * simultaneous SYN, which is handled later.
9111 */
9112 if (SEQ_GT(th->th_ack, tp->snd_una) && !(tp->t_flags & TF_NEEDSYN))
9113 tp->snd_una++;
9114 /*
9115 * If segment contains data or ACK, will call tcp_reass() later; if
9116 * not, do so now to pass queued data to user.
9117 */
9118 if (tlen == 0 && (thflags & TH_FIN) == 0) {
9119 (void)tcp_reass(tp, (struct tcphdr *)0, NULL, 0,
9120 (struct mbuf *)0);
9121 if (tp->t_flags & TF_WAKESOR) {
9122 tp->t_flags &= ~TF_WAKESOR;
9123 /* NB: sorwakeup_locked() does an implicit unlock. */
9124 sorwakeup_locked(so);
9125 }
9126 }
9127 tp->snd_wl1 = th->th_seq - 1;
9128 if (bbr_process_ack(m, th, so, tp, to, tiwin, tlen, &ourfinisacked, thflags, &ret_val)) {
9129 return (ret_val);
9130 }
9131 if (tp->t_state == TCPS_FIN_WAIT_1) {
9132 /* We could have went to FIN_WAIT_1 (or EST) above */
9133 /*
9134 * In FIN_WAIT_1 STATE in addition to the processing for the
9135 * ESTABLISHED state if our FIN is now acknowledged then
9136 * enter FIN_WAIT_2.
9137 */
9138 if (ourfinisacked) {
9139 /*
9140 * If we can't receive any more data, then closing
9141 * user can proceed. Starting the timer is contrary
9142 * to the specification, but if we don't get a FIN
9143 * we'll hang forever.
9144 *
9145 * XXXjl: we should release the tp also, and use a
9146 * compressed state.
9147 */
9148 if (so->so_rcv.sb_state & SBS_CANTRCVMORE) {
9149 soisdisconnected(so);
9150 tcp_timer_activate(tp, TT_2MSL,
9151 (tcp_fast_finwait2_recycle ?
9152 tcp_finwait2_timeout :
9153 TP_MAXIDLE(tp)));
9154 }
9155 tcp_state_change(tp, TCPS_FIN_WAIT_2);
9156 }
9157 }
9158 return (bbr_process_data(m, th, so, tp, drop_hdrlen, tlen,
9159 tiwin, thflags, nxt_pkt));
9160 }
9161
9162 /*
9163 * Return value of 1, the TCB is unlocked and most
9164 * likely gone, return value of 0, the TCB is still
9165 * locked.
9166 */
9167 static int
bbr_do_established(struct mbuf * m,struct tcphdr * th,struct socket * so,struct tcpcb * tp,struct tcpopt * to,int32_t drop_hdrlen,int32_t tlen,uint32_t tiwin,int32_t thflags,int32_t nxt_pkt,uint8_t iptos)9168 bbr_do_established(struct mbuf *m, struct tcphdr *th, struct socket *so,
9169 struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen,
9170 uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos)
9171 {
9172 struct tcp_bbr *bbr;
9173 int32_t ret_val;
9174
9175 INP_WLOCK_ASSERT(tptoinpcb(tp));
9176
9177 /*
9178 * Header prediction: check for the two common cases of a
9179 * uni-directional data xfer. If the packet has no control flags,
9180 * is in-sequence, the window didn't change and we're not
9181 * retransmitting, it's a candidate. If the length is zero and the
9182 * ack moved forward, we're the sender side of the xfer. Just free
9183 * the data acked & wake any higher level process that was blocked
9184 * waiting for space. If the length is non-zero and the ack didn't
9185 * move, we're the receiver side. If we're getting packets in-order
9186 * (the reassembly queue is empty), add the data toc The socket
9187 * buffer and note that we need a delayed ack. Make sure that the
9188 * hidden state-flags are also off. Since we check for
9189 * TCPS_ESTABLISHED first, it can only be TH_NEEDSYN.
9190 */
9191 bbr = (struct tcp_bbr *)tp->t_fb_ptr;
9192 if (bbr->r_ctl.rc_delivered < (4 * tp->t_maxseg)) {
9193 /*
9194 * If we have delived under 4 segments increase the initial
9195 * window if raised by the peer. We use this to determine
9196 * dynamic and static rwnd's at the end of a connection.
9197 */
9198 bbr->r_ctl.rc_init_rwnd = max(tiwin, tp->snd_wnd);
9199 }
9200 if (__predict_true(((to->to_flags & TOF_SACK) == 0)) &&
9201 __predict_true((thflags & (TH_SYN | TH_FIN | TH_RST | TH_URG | TH_ACK)) == TH_ACK) &&
9202 __predict_true(SEGQ_EMPTY(tp)) &&
9203 __predict_true(th->th_seq == tp->rcv_nxt)) {
9204 if (tlen == 0) {
9205 if (bbr_fastack(m, th, so, tp, to, drop_hdrlen, tlen,
9206 tiwin, nxt_pkt, iptos)) {
9207 return (0);
9208 }
9209 } else {
9210 if (bbr_do_fastnewdata(m, th, so, tp, to, drop_hdrlen, tlen,
9211 tiwin, nxt_pkt)) {
9212 return (0);
9213 }
9214 }
9215 }
9216 ctf_calc_rwin(so, tp);
9217
9218 if ((thflags & TH_RST) ||
9219 (tp->t_fin_is_rst && (thflags & TH_FIN)))
9220 return (ctf_process_rst(m, th, so, tp));
9221 /*
9222 * RFC5961 Section 4.2 Send challenge ACK for any SYN in
9223 * synchronized state.
9224 */
9225 if (thflags & TH_SYN) {
9226 ctf_challenge_ack(m, th, tp, iptos, &ret_val);
9227 return (ret_val);
9228 }
9229 /*
9230 * RFC 1323 PAWS: If we have a timestamp reply on this segment and
9231 * it's less than ts_recent, drop it.
9232 */
9233 if ((to->to_flags & TOF_TS) != 0 && tp->ts_recent &&
9234 TSTMP_LT(to->to_tsval, tp->ts_recent)) {
9235 if (ctf_ts_check(m, th, tp, tlen, thflags, &ret_val))
9236 return (ret_val);
9237 }
9238 if (ctf_drop_checks(to, m, th, tp, &tlen, &thflags, &drop_hdrlen, &ret_val)) {
9239 return (ret_val);
9240 }
9241 /*
9242 * If last ACK falls within this segment's sequence numbers, record
9243 * its timestamp. NOTE: 1) That the test incorporates suggestions
9244 * from the latest proposal of the tcplw@cray.com list (Braden
9245 * 1993/04/26). 2) That updating only on newer timestamps interferes
9246 * with our earlier PAWS tests, so this check should be solely
9247 * predicated on the sequence space of this segment. 3) That we
9248 * modify the segment boundary check to be Last.ACK.Sent <= SEG.SEQ
9249 * + SEG.Len instead of RFC1323's Last.ACK.Sent < SEG.SEQ +
9250 * SEG.Len, This modified check allows us to overcome RFC1323's
9251 * limitations as described in Stevens TCP/IP Illustrated Vol. 2
9252 * p.869. In such cases, we can still calculate the RTT correctly
9253 * when RCV.NXT == Last.ACK.Sent.
9254 */
9255 if ((to->to_flags & TOF_TS) != 0 &&
9256 SEQ_LEQ(th->th_seq, tp->last_ack_sent) &&
9257 SEQ_LEQ(tp->last_ack_sent, th->th_seq + tlen +
9258 ((thflags & (TH_SYN | TH_FIN)) != 0))) {
9259 tp->ts_recent_age = tcp_tv_to_msec(&bbr->rc_tv);
9260 tp->ts_recent = to->to_tsval;
9261 }
9262 /*
9263 * If the ACK bit is off: if in SYN-RECEIVED state or SENDSYN flag
9264 * is on (half-synchronized state), then queue data for later
9265 * processing; else drop segment and return.
9266 */
9267 if ((thflags & TH_ACK) == 0) {
9268 if (tp->t_flags & TF_NEEDSYN) {
9269 return (bbr_process_data(m, th, so, tp, drop_hdrlen, tlen,
9270 tiwin, thflags, nxt_pkt));
9271 } else if (tp->t_flags & TF_ACKNOW) {
9272 ctf_do_dropafterack(m, tp, th, thflags, tlen, &ret_val);
9273 bbr->r_wanted_output = 1;
9274 return (ret_val);
9275 } else {
9276 ctf_do_drop(m, NULL);
9277 return (0);
9278 }
9279 }
9280 /*
9281 * Ack processing.
9282 */
9283 if (bbr_process_ack(m, th, so, tp, to, tiwin, tlen, NULL, thflags, &ret_val)) {
9284 return (ret_val);
9285 }
9286 if (sbavail(&so->so_snd)) {
9287 if (ctf_progress_timeout_check(tp, true)) {
9288 bbr_log_progress_event(bbr, tp, tick, PROGRESS_DROP, __LINE__);
9289 ctf_do_dropwithreset_conn(m, tp, th, tlen);
9290 return (1);
9291 }
9292 }
9293 /* State changes only happen in bbr_process_data() */
9294 return (bbr_process_data(m, th, so, tp, drop_hdrlen, tlen,
9295 tiwin, thflags, nxt_pkt));
9296 }
9297
9298 /*
9299 * Return value of 1, the TCB is unlocked and most
9300 * likely gone, return value of 0, the TCB is still
9301 * locked.
9302 */
9303 static int
bbr_do_close_wait(struct mbuf * m,struct tcphdr * th,struct socket * so,struct tcpcb * tp,struct tcpopt * to,int32_t drop_hdrlen,int32_t tlen,uint32_t tiwin,int32_t thflags,int32_t nxt_pkt,uint8_t iptos)9304 bbr_do_close_wait(struct mbuf *m, struct tcphdr *th, struct socket *so,
9305 struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen,
9306 uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos)
9307 {
9308 struct tcp_bbr *bbr;
9309 int32_t ret_val;
9310
9311 INP_WLOCK_ASSERT(tptoinpcb(tp));
9312
9313 bbr = (struct tcp_bbr *)tp->t_fb_ptr;
9314 ctf_calc_rwin(so, tp);
9315 if ((thflags & TH_RST) ||
9316 (tp->t_fin_is_rst && (thflags & TH_FIN)))
9317 return (ctf_process_rst(m, th, so, tp));
9318 /*
9319 * RFC5961 Section 4.2 Send challenge ACK for any SYN in
9320 * synchronized state.
9321 */
9322 if (thflags & TH_SYN) {
9323 ctf_challenge_ack(m, th, tp, iptos, &ret_val);
9324 return (ret_val);
9325 }
9326 /*
9327 * RFC 1323 PAWS: If we have a timestamp reply on this segment and
9328 * it's less than ts_recent, drop it.
9329 */
9330 if ((to->to_flags & TOF_TS) != 0 && tp->ts_recent &&
9331 TSTMP_LT(to->to_tsval, tp->ts_recent)) {
9332 if (ctf_ts_check(m, th, tp, tlen, thflags, &ret_val))
9333 return (ret_val);
9334 }
9335 if (ctf_drop_checks(to, m, th, tp, &tlen, &thflags, &drop_hdrlen, &ret_val)) {
9336 return (ret_val);
9337 }
9338 /*
9339 * If last ACK falls within this segment's sequence numbers, record
9340 * its timestamp. NOTE: 1) That the test incorporates suggestions
9341 * from the latest proposal of the tcplw@cray.com list (Braden
9342 * 1993/04/26). 2) That updating only on newer timestamps interferes
9343 * with our earlier PAWS tests, so this check should be solely
9344 * predicated on the sequence space of this segment. 3) That we
9345 * modify the segment boundary check to be Last.ACK.Sent <= SEG.SEQ
9346 * + SEG.Len instead of RFC1323's Last.ACK.Sent < SEG.SEQ +
9347 * SEG.Len, This modified check allows us to overcome RFC1323's
9348 * limitations as described in Stevens TCP/IP Illustrated Vol. 2
9349 * p.869. In such cases, we can still calculate the RTT correctly
9350 * when RCV.NXT == Last.ACK.Sent.
9351 */
9352 if ((to->to_flags & TOF_TS) != 0 &&
9353 SEQ_LEQ(th->th_seq, tp->last_ack_sent) &&
9354 SEQ_LEQ(tp->last_ack_sent, th->th_seq + tlen +
9355 ((thflags & (TH_SYN | TH_FIN)) != 0))) {
9356 tp->ts_recent_age = tcp_tv_to_msec(&bbr->rc_tv);
9357 tp->ts_recent = to->to_tsval;
9358 }
9359 /*
9360 * If the ACK bit is off: if in SYN-RECEIVED state or SENDSYN flag
9361 * is on (half-synchronized state), then queue data for later
9362 * processing; else drop segment and return.
9363 */
9364 if ((thflags & TH_ACK) == 0) {
9365 if (tp->t_flags & TF_NEEDSYN) {
9366 return (bbr_process_data(m, th, so, tp, drop_hdrlen, tlen,
9367 tiwin, thflags, nxt_pkt));
9368 } else if (tp->t_flags & TF_ACKNOW) {
9369 ctf_do_dropafterack(m, tp, th, thflags, tlen, &ret_val);
9370 bbr->r_wanted_output = 1;
9371 return (ret_val);
9372 } else {
9373 ctf_do_drop(m, NULL);
9374 return (0);
9375 }
9376 }
9377 /*
9378 * Ack processing.
9379 */
9380 if (bbr_process_ack(m, th, so, tp, to, tiwin, tlen, NULL, thflags, &ret_val)) {
9381 return (ret_val);
9382 }
9383 if (sbavail(&so->so_snd)) {
9384 if (ctf_progress_timeout_check(tp, true)) {
9385 bbr_log_progress_event(bbr, tp, tick, PROGRESS_DROP, __LINE__);
9386 ctf_do_dropwithreset_conn(m, tp, th, tlen);
9387 return (1);
9388 }
9389 }
9390 return (bbr_process_data(m, th, so, tp, drop_hdrlen, tlen,
9391 tiwin, thflags, nxt_pkt));
9392 }
9393
9394 static int
bbr_check_data_after_close(struct mbuf * m,struct tcp_bbr * bbr,struct tcpcb * tp,int32_t * tlen,struct tcphdr * th,struct socket * so)9395 bbr_check_data_after_close(struct mbuf *m, struct tcp_bbr *bbr,
9396 struct tcpcb *tp, int32_t * tlen, struct tcphdr *th, struct socket *so)
9397 {
9398
9399 if (bbr->rc_allow_data_af_clo == 0) {
9400 close_now:
9401 tcp_log_end_status(tp, TCP_EI_STATUS_DATA_A_CLOSE);
9402 /* tcp_close will kill the inp pre-log the Reset */
9403 tcp_log_end_status(tp, TCP_EI_STATUS_SERVER_RST);
9404 tp = tcp_close(tp);
9405 KMOD_TCPSTAT_INC(tcps_rcvafterclose);
9406 ctf_do_dropwithreset(m, tp, th, *tlen);
9407 return (1);
9408 }
9409 if (sbavail(&so->so_snd) == 0)
9410 goto close_now;
9411 /* Ok we allow data that is ignored and a followup reset */
9412 tp->rcv_nxt = th->th_seq + *tlen;
9413 tp->t_flags2 |= TF2_DROP_AF_DATA;
9414 bbr->r_wanted_output = 1;
9415 *tlen = 0;
9416 return (0);
9417 }
9418
9419 /*
9420 * Return value of 1, the TCB is unlocked and most
9421 * likely gone, return value of 0, the TCB is still
9422 * locked.
9423 */
9424 static int
bbr_do_fin_wait_1(struct mbuf * m,struct tcphdr * th,struct socket * so,struct tcpcb * tp,struct tcpopt * to,int32_t drop_hdrlen,int32_t tlen,uint32_t tiwin,int32_t thflags,int32_t nxt_pkt,uint8_t iptos)9425 bbr_do_fin_wait_1(struct mbuf *m, struct tcphdr *th, struct socket *so,
9426 struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen,
9427 uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos)
9428 {
9429 int32_t ourfinisacked = 0;
9430 int32_t ret_val;
9431 struct tcp_bbr *bbr;
9432
9433 INP_WLOCK_ASSERT(tptoinpcb(tp));
9434
9435 bbr = (struct tcp_bbr *)tp->t_fb_ptr;
9436 ctf_calc_rwin(so, tp);
9437 if ((thflags & TH_RST) ||
9438 (tp->t_fin_is_rst && (thflags & TH_FIN)))
9439 return (ctf_process_rst(m, th, so, tp));
9440 /*
9441 * RFC5961 Section 4.2 Send challenge ACK for any SYN in
9442 * synchronized state.
9443 */
9444 if (thflags & TH_SYN) {
9445 ctf_challenge_ack(m, th, tp, iptos, &ret_val);
9446 return (ret_val);
9447 }
9448 /*
9449 * RFC 1323 PAWS: If we have a timestamp reply on this segment and
9450 * it's less than ts_recent, drop it.
9451 */
9452 if ((to->to_flags & TOF_TS) != 0 && tp->ts_recent &&
9453 TSTMP_LT(to->to_tsval, tp->ts_recent)) {
9454 if (ctf_ts_check(m, th, tp, tlen, thflags, &ret_val))
9455 return (ret_val);
9456 }
9457 if (ctf_drop_checks(to, m, th, tp, &tlen, &thflags, &drop_hdrlen, &ret_val)) {
9458 return (ret_val);
9459 }
9460 /*
9461 * If new data are received on a connection after the user processes
9462 * are gone, then RST the other end.
9463 * We call a new function now so we might continue and setup
9464 * to reset at all data being ack'd.
9465 */
9466 if ((tp->t_flags & TF_CLOSED) && tlen &&
9467 bbr_check_data_after_close(m, bbr, tp, &tlen, th, so))
9468 return (1);
9469 /*
9470 * If last ACK falls within this segment's sequence numbers, record
9471 * its timestamp. NOTE: 1) That the test incorporates suggestions
9472 * from the latest proposal of the tcplw@cray.com list (Braden
9473 * 1993/04/26). 2) That updating only on newer timestamps interferes
9474 * with our earlier PAWS tests, so this check should be solely
9475 * predicated on the sequence space of this segment. 3) That we
9476 * modify the segment boundary check to be Last.ACK.Sent <= SEG.SEQ
9477 * + SEG.Len instead of RFC1323's Last.ACK.Sent < SEG.SEQ +
9478 * SEG.Len, This modified check allows us to overcome RFC1323's
9479 * limitations as described in Stevens TCP/IP Illustrated Vol. 2
9480 * p.869. In such cases, we can still calculate the RTT correctly
9481 * when RCV.NXT == Last.ACK.Sent.
9482 */
9483 if ((to->to_flags & TOF_TS) != 0 &&
9484 SEQ_LEQ(th->th_seq, tp->last_ack_sent) &&
9485 SEQ_LEQ(tp->last_ack_sent, th->th_seq + tlen +
9486 ((thflags & (TH_SYN | TH_FIN)) != 0))) {
9487 tp->ts_recent_age = tcp_tv_to_msec(&bbr->rc_tv);
9488 tp->ts_recent = to->to_tsval;
9489 }
9490 /*
9491 * If the ACK bit is off: if in SYN-RECEIVED state or SENDSYN flag
9492 * is on (half-synchronized state), then queue data for later
9493 * processing; else drop segment and return.
9494 */
9495 if ((thflags & TH_ACK) == 0) {
9496 if (tp->t_flags & TF_NEEDSYN) {
9497 return (bbr_process_data(m, th, so, tp, drop_hdrlen, tlen,
9498 tiwin, thflags, nxt_pkt));
9499 } else if (tp->t_flags & TF_ACKNOW) {
9500 ctf_do_dropafterack(m, tp, th, thflags, tlen, &ret_val);
9501 bbr->r_wanted_output = 1;
9502 return (ret_val);
9503 } else {
9504 ctf_do_drop(m, NULL);
9505 return (0);
9506 }
9507 }
9508 /*
9509 * Ack processing.
9510 */
9511 if (bbr_process_ack(m, th, so, tp, to, tiwin, tlen, &ourfinisacked, thflags, &ret_val)) {
9512 return (ret_val);
9513 }
9514 if (ourfinisacked) {
9515 /*
9516 * If we can't receive any more data, then closing user can
9517 * proceed. Starting the timer is contrary to the
9518 * specification, but if we don't get a FIN we'll hang
9519 * forever.
9520 *
9521 * XXXjl: we should release the tp also, and use a
9522 * compressed state.
9523 */
9524 if (so->so_rcv.sb_state & SBS_CANTRCVMORE) {
9525 soisdisconnected(so);
9526 tcp_timer_activate(tp, TT_2MSL,
9527 (tcp_fast_finwait2_recycle ?
9528 tcp_finwait2_timeout :
9529 TP_MAXIDLE(tp)));
9530 }
9531 tcp_state_change(tp, TCPS_FIN_WAIT_2);
9532 }
9533 if (sbavail(&so->so_snd)) {
9534 if (ctf_progress_timeout_check(tp, true)) {
9535 bbr_log_progress_event(bbr, tp, tick, PROGRESS_DROP, __LINE__);
9536 ctf_do_dropwithreset_conn(m, tp, th, tlen);
9537 return (1);
9538 }
9539 }
9540 return (bbr_process_data(m, th, so, tp, drop_hdrlen, tlen,
9541 tiwin, thflags, nxt_pkt));
9542 }
9543
9544 /*
9545 * Return value of 1, the TCB is unlocked and most
9546 * likely gone, return value of 0, the TCB is still
9547 * locked.
9548 */
9549 static int
bbr_do_closing(struct mbuf * m,struct tcphdr * th,struct socket * so,struct tcpcb * tp,struct tcpopt * to,int32_t drop_hdrlen,int32_t tlen,uint32_t tiwin,int32_t thflags,int32_t nxt_pkt,uint8_t iptos)9550 bbr_do_closing(struct mbuf *m, struct tcphdr *th, struct socket *so,
9551 struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen,
9552 uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos)
9553 {
9554 int32_t ourfinisacked = 0;
9555 int32_t ret_val;
9556 struct tcp_bbr *bbr;
9557
9558 INP_WLOCK_ASSERT(tptoinpcb(tp));
9559
9560 bbr = (struct tcp_bbr *)tp->t_fb_ptr;
9561 ctf_calc_rwin(so, tp);
9562 if ((thflags & TH_RST) ||
9563 (tp->t_fin_is_rst && (thflags & TH_FIN)))
9564 return (ctf_process_rst(m, th, so, tp));
9565 /*
9566 * RFC5961 Section 4.2 Send challenge ACK for any SYN in
9567 * synchronized state.
9568 */
9569 if (thflags & TH_SYN) {
9570 ctf_challenge_ack(m, th, tp, iptos, &ret_val);
9571 return (ret_val);
9572 }
9573 /*
9574 * RFC 1323 PAWS: If we have a timestamp reply on this segment and
9575 * it's less than ts_recent, drop it.
9576 */
9577 if ((to->to_flags & TOF_TS) != 0 && tp->ts_recent &&
9578 TSTMP_LT(to->to_tsval, tp->ts_recent)) {
9579 if (ctf_ts_check(m, th, tp, tlen, thflags, &ret_val))
9580 return (ret_val);
9581 }
9582 if (ctf_drop_checks(to, m, th, tp, &tlen, &thflags, &drop_hdrlen, &ret_val)) {
9583 return (ret_val);
9584 }
9585 /*
9586 * If last ACK falls within this segment's sequence numbers, record
9587 * its timestamp. NOTE: 1) That the test incorporates suggestions
9588 * from the latest proposal of the tcplw@cray.com list (Braden
9589 * 1993/04/26). 2) That updating only on newer timestamps interferes
9590 * with our earlier PAWS tests, so this check should be solely
9591 * predicated on the sequence space of this segment. 3) That we
9592 * modify the segment boundary check to be Last.ACK.Sent <= SEG.SEQ
9593 * + SEG.Len instead of RFC1323's Last.ACK.Sent < SEG.SEQ +
9594 * SEG.Len, This modified check allows us to overcome RFC1323's
9595 * limitations as described in Stevens TCP/IP Illustrated Vol. 2
9596 * p.869. In such cases, we can still calculate the RTT correctly
9597 * when RCV.NXT == Last.ACK.Sent.
9598 */
9599 if ((to->to_flags & TOF_TS) != 0 &&
9600 SEQ_LEQ(th->th_seq, tp->last_ack_sent) &&
9601 SEQ_LEQ(tp->last_ack_sent, th->th_seq + tlen +
9602 ((thflags & (TH_SYN | TH_FIN)) != 0))) {
9603 tp->ts_recent_age = tcp_tv_to_msec(&bbr->rc_tv);
9604 tp->ts_recent = to->to_tsval;
9605 }
9606 /*
9607 * If the ACK bit is off: if in SYN-RECEIVED state or SENDSYN flag
9608 * is on (half-synchronized state), then queue data for later
9609 * processing; else drop segment and return.
9610 */
9611 if ((thflags & TH_ACK) == 0) {
9612 if (tp->t_flags & TF_NEEDSYN) {
9613 return (bbr_process_data(m, th, so, tp, drop_hdrlen, tlen,
9614 tiwin, thflags, nxt_pkt));
9615 } else if (tp->t_flags & TF_ACKNOW) {
9616 ctf_do_dropafterack(m, tp, th, thflags, tlen, &ret_val);
9617 bbr->r_wanted_output = 1;
9618 return (ret_val);
9619 } else {
9620 ctf_do_drop(m, NULL);
9621 return (0);
9622 }
9623 }
9624 /*
9625 * Ack processing.
9626 */
9627 if (bbr_process_ack(m, th, so, tp, to, tiwin, tlen, &ourfinisacked, thflags, &ret_val)) {
9628 return (ret_val);
9629 }
9630 if (ourfinisacked) {
9631 tcp_twstart(tp);
9632 m_freem(m);
9633 return (1);
9634 }
9635 if (sbavail(&so->so_snd)) {
9636 if (ctf_progress_timeout_check(tp, true)) {
9637 bbr_log_progress_event(bbr, tp, tick, PROGRESS_DROP, __LINE__);
9638 ctf_do_dropwithreset_conn(m, tp, th, tlen);
9639 return (1);
9640 }
9641 }
9642 return (bbr_process_data(m, th, so, tp, drop_hdrlen, tlen,
9643 tiwin, thflags, nxt_pkt));
9644 }
9645
9646 /*
9647 * Return value of 1, the TCB is unlocked and most
9648 * likely gone, return value of 0, the TCB is still
9649 * locked.
9650 */
9651 static int
bbr_do_lastack(struct mbuf * m,struct tcphdr * th,struct socket * so,struct tcpcb * tp,struct tcpopt * to,int32_t drop_hdrlen,int32_t tlen,uint32_t tiwin,int32_t thflags,int32_t nxt_pkt,uint8_t iptos)9652 bbr_do_lastack(struct mbuf *m, struct tcphdr *th, struct socket *so,
9653 struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen,
9654 uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos)
9655 {
9656 int32_t ourfinisacked = 0;
9657 int32_t ret_val;
9658 struct tcp_bbr *bbr;
9659
9660 INP_WLOCK_ASSERT(tptoinpcb(tp));
9661
9662 bbr = (struct tcp_bbr *)tp->t_fb_ptr;
9663 ctf_calc_rwin(so, tp);
9664 if ((thflags & TH_RST) ||
9665 (tp->t_fin_is_rst && (thflags & TH_FIN)))
9666 return (ctf_process_rst(m, th, so, tp));
9667 /*
9668 * RFC5961 Section 4.2 Send challenge ACK for any SYN in
9669 * synchronized state.
9670 */
9671 if (thflags & TH_SYN) {
9672 ctf_challenge_ack(m, th, tp, iptos, &ret_val);
9673 return (ret_val);
9674 }
9675 /*
9676 * RFC 1323 PAWS: If we have a timestamp reply on this segment and
9677 * it's less than ts_recent, drop it.
9678 */
9679 if ((to->to_flags & TOF_TS) != 0 && tp->ts_recent &&
9680 TSTMP_LT(to->to_tsval, tp->ts_recent)) {
9681 if (ctf_ts_check(m, th, tp, tlen, thflags, &ret_val))
9682 return (ret_val);
9683 }
9684 if (ctf_drop_checks(to, m, th, tp, &tlen, &thflags, &drop_hdrlen, &ret_val)) {
9685 return (ret_val);
9686 }
9687 /*
9688 * If last ACK falls within this segment's sequence numbers, record
9689 * its timestamp. NOTE: 1) That the test incorporates suggestions
9690 * from the latest proposal of the tcplw@cray.com list (Braden
9691 * 1993/04/26). 2) That updating only on newer timestamps interferes
9692 * with our earlier PAWS tests, so this check should be solely
9693 * predicated on the sequence space of this segment. 3) That we
9694 * modify the segment boundary check to be Last.ACK.Sent <= SEG.SEQ
9695 * + SEG.Len instead of RFC1323's Last.ACK.Sent < SEG.SEQ +
9696 * SEG.Len, This modified check allows us to overcome RFC1323's
9697 * limitations as described in Stevens TCP/IP Illustrated Vol. 2
9698 * p.869. In such cases, we can still calculate the RTT correctly
9699 * when RCV.NXT == Last.ACK.Sent.
9700 */
9701 if ((to->to_flags & TOF_TS) != 0 &&
9702 SEQ_LEQ(th->th_seq, tp->last_ack_sent) &&
9703 SEQ_LEQ(tp->last_ack_sent, th->th_seq + tlen +
9704 ((thflags & (TH_SYN | TH_FIN)) != 0))) {
9705 tp->ts_recent_age = tcp_tv_to_msec(&bbr->rc_tv);
9706 tp->ts_recent = to->to_tsval;
9707 }
9708 /*
9709 * If the ACK bit is off: if in SYN-RECEIVED state or SENDSYN flag
9710 * is on (half-synchronized state), then queue data for later
9711 * processing; else drop segment and return.
9712 */
9713 if ((thflags & TH_ACK) == 0) {
9714 if (tp->t_flags & TF_NEEDSYN) {
9715 return (bbr_process_data(m, th, so, tp, drop_hdrlen, tlen,
9716 tiwin, thflags, nxt_pkt));
9717 } else if (tp->t_flags & TF_ACKNOW) {
9718 ctf_do_dropafterack(m, tp, th, thflags, tlen, &ret_val);
9719 bbr->r_wanted_output = 1;
9720 return (ret_val);
9721 } else {
9722 ctf_do_drop(m, NULL);
9723 return (0);
9724 }
9725 }
9726 /*
9727 * case TCPS_LAST_ACK: Ack processing.
9728 */
9729 if (bbr_process_ack(m, th, so, tp, to, tiwin, tlen, &ourfinisacked, thflags, &ret_val)) {
9730 return (ret_val);
9731 }
9732 if (ourfinisacked) {
9733 tp = tcp_close(tp);
9734 ctf_do_drop(m, tp);
9735 return (1);
9736 }
9737 if (sbavail(&so->so_snd)) {
9738 if (ctf_progress_timeout_check(tp, true)) {
9739 bbr_log_progress_event(bbr, tp, tick, PROGRESS_DROP, __LINE__);
9740 ctf_do_dropwithreset_conn(m, tp, th, tlen);
9741 return (1);
9742 }
9743 }
9744 return (bbr_process_data(m, th, so, tp, drop_hdrlen, tlen,
9745 tiwin, thflags, nxt_pkt));
9746 }
9747
9748 /*
9749 * Return value of 1, the TCB is unlocked and most
9750 * likely gone, return value of 0, the TCB is still
9751 * locked.
9752 */
9753 static int
bbr_do_fin_wait_2(struct mbuf * m,struct tcphdr * th,struct socket * so,struct tcpcb * tp,struct tcpopt * to,int32_t drop_hdrlen,int32_t tlen,uint32_t tiwin,int32_t thflags,int32_t nxt_pkt,uint8_t iptos)9754 bbr_do_fin_wait_2(struct mbuf *m, struct tcphdr *th, struct socket *so,
9755 struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen,
9756 uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos)
9757 {
9758 int32_t ourfinisacked = 0;
9759 int32_t ret_val;
9760 struct tcp_bbr *bbr;
9761
9762 INP_WLOCK_ASSERT(tptoinpcb(tp));
9763
9764 bbr = (struct tcp_bbr *)tp->t_fb_ptr;
9765 ctf_calc_rwin(so, tp);
9766 /* Reset receive buffer auto scaling when not in bulk receive mode. */
9767 if ((thflags & TH_RST) ||
9768 (tp->t_fin_is_rst && (thflags & TH_FIN)))
9769 return (ctf_process_rst(m, th, so, tp));
9770
9771 /*
9772 * RFC5961 Section 4.2 Send challenge ACK for any SYN in
9773 * synchronized state.
9774 */
9775 if (thflags & TH_SYN) {
9776 ctf_challenge_ack(m, th, tp, iptos, &ret_val);
9777 return (ret_val);
9778 }
9779 /*
9780 * RFC 1323 PAWS: If we have a timestamp reply on this segment and
9781 * it's less than ts_recent, drop it.
9782 */
9783 if ((to->to_flags & TOF_TS) != 0 && tp->ts_recent &&
9784 TSTMP_LT(to->to_tsval, tp->ts_recent)) {
9785 if (ctf_ts_check(m, th, tp, tlen, thflags, &ret_val))
9786 return (ret_val);
9787 }
9788 if (ctf_drop_checks(to, m, th, tp, &tlen, &thflags, &drop_hdrlen, &ret_val)) {
9789 return (ret_val);
9790 }
9791 /*
9792 * If new data are received on a connection after the user processes
9793 * are gone, then we may RST the other end depending on the outcome
9794 * of bbr_check_data_after_close.
9795 * We call a new function now so we might continue and setup
9796 * to reset at all data being ack'd.
9797 */
9798 if ((tp->t_flags & TF_CLOSED) && tlen &&
9799 bbr_check_data_after_close(m, bbr, tp, &tlen, th, so))
9800 return (1);
9801 /*
9802 * If last ACK falls within this segment's sequence numbers, record
9803 * its timestamp. NOTE: 1) That the test incorporates suggestions
9804 * from the latest proposal of the tcplw@cray.com list (Braden
9805 * 1993/04/26). 2) That updating only on newer timestamps interferes
9806 * with our earlier PAWS tests, so this check should be solely
9807 * predicated on the sequence space of this segment. 3) That we
9808 * modify the segment boundary check to be Last.ACK.Sent <= SEG.SEQ
9809 * + SEG.Len instead of RFC1323's Last.ACK.Sent < SEG.SEQ +
9810 * SEG.Len, This modified check allows us to overcome RFC1323's
9811 * limitations as described in Stevens TCP/IP Illustrated Vol. 2
9812 * p.869. In such cases, we can still calculate the RTT correctly
9813 * when RCV.NXT == Last.ACK.Sent.
9814 */
9815 if ((to->to_flags & TOF_TS) != 0 &&
9816 SEQ_LEQ(th->th_seq, tp->last_ack_sent) &&
9817 SEQ_LEQ(tp->last_ack_sent, th->th_seq + tlen +
9818 ((thflags & (TH_SYN | TH_FIN)) != 0))) {
9819 tp->ts_recent_age = tcp_tv_to_msec(&bbr->rc_tv);
9820 tp->ts_recent = to->to_tsval;
9821 }
9822 /*
9823 * If the ACK bit is off: if in SYN-RECEIVED state or SENDSYN flag
9824 * is on (half-synchronized state), then queue data for later
9825 * processing; else drop segment and return.
9826 */
9827 if ((thflags & TH_ACK) == 0) {
9828 if (tp->t_flags & TF_NEEDSYN) {
9829 return (bbr_process_data(m, th, so, tp, drop_hdrlen, tlen,
9830 tiwin, thflags, nxt_pkt));
9831 } else if (tp->t_flags & TF_ACKNOW) {
9832 ctf_do_dropafterack(m, tp, th, thflags, tlen, &ret_val);
9833 bbr->r_wanted_output = 1;
9834 return (ret_val);
9835 } else {
9836 ctf_do_drop(m, NULL);
9837 return (0);
9838 }
9839 }
9840 /*
9841 * Ack processing.
9842 */
9843 if (bbr_process_ack(m, th, so, tp, to, tiwin, tlen, &ourfinisacked, thflags, &ret_val)) {
9844 return (ret_val);
9845 }
9846 if (sbavail(&so->so_snd)) {
9847 if (ctf_progress_timeout_check(tp, true)) {
9848 bbr_log_progress_event(bbr, tp, tick, PROGRESS_DROP, __LINE__);
9849 ctf_do_dropwithreset_conn(m, tp, th, tlen);
9850 return (1);
9851 }
9852 }
9853 return (bbr_process_data(m, th, so, tp, drop_hdrlen, tlen,
9854 tiwin, thflags, nxt_pkt));
9855 }
9856
9857 static void
bbr_stop_all_timers(struct tcpcb * tp,struct tcp_bbr * bbr)9858 bbr_stop_all_timers(struct tcpcb *tp, struct tcp_bbr *bbr)
9859 {
9860 /*
9861 * Assure no timers are running.
9862 */
9863 if (tcp_timer_active(tp, TT_PERSIST)) {
9864 /* We enter in persists, set the flag appropriately */
9865 bbr->rc_in_persist = 1;
9866 }
9867 if (tcp_in_hpts(bbr->rc_tp)) {
9868 tcp_hpts_remove(bbr->rc_tp);
9869 }
9870 }
9871
9872 static void
bbr_google_mode_on(struct tcp_bbr * bbr)9873 bbr_google_mode_on(struct tcp_bbr *bbr)
9874 {
9875 bbr->rc_use_google = 1;
9876 bbr->rc_no_pacing = 0;
9877 bbr->r_ctl.bbr_google_discount = bbr_google_discount;
9878 bbr->r_use_policer = bbr_policer_detection_enabled;
9879 bbr->r_ctl.rc_probertt_int = (USECS_IN_SECOND * 10);
9880 bbr->bbr_use_rack_cheat = 0;
9881 bbr->r_ctl.rc_incr_tmrs = 0;
9882 bbr->r_ctl.rc_inc_tcp_oh = 0;
9883 bbr->r_ctl.rc_inc_ip_oh = 0;
9884 bbr->r_ctl.rc_inc_enet_oh = 0;
9885 reset_time(&bbr->r_ctl.rc_delrate,
9886 BBR_NUM_RTTS_FOR_GOOG_DEL_LIMIT);
9887 reset_time_small(&bbr->r_ctl.rc_rttprop,
9888 (11 * USECS_IN_SECOND));
9889 tcp_bbr_tso_size_check(bbr, tcp_get_usecs(&bbr->rc_tv));
9890 }
9891
9892 static void
bbr_google_mode_off(struct tcp_bbr * bbr)9893 bbr_google_mode_off(struct tcp_bbr *bbr)
9894 {
9895 bbr->rc_use_google = 0;
9896 bbr->r_ctl.bbr_google_discount = 0;
9897 bbr->no_pacing_until = bbr_no_pacing_until;
9898 bbr->r_use_policer = 0;
9899 if (bbr->no_pacing_until)
9900 bbr->rc_no_pacing = 1;
9901 else
9902 bbr->rc_no_pacing = 0;
9903 if (bbr_use_rack_resend_cheat)
9904 bbr->bbr_use_rack_cheat = 1;
9905 else
9906 bbr->bbr_use_rack_cheat = 0;
9907 if (bbr_incr_timers)
9908 bbr->r_ctl.rc_incr_tmrs = 1;
9909 else
9910 bbr->r_ctl.rc_incr_tmrs = 0;
9911 if (bbr_include_tcp_oh)
9912 bbr->r_ctl.rc_inc_tcp_oh = 1;
9913 else
9914 bbr->r_ctl.rc_inc_tcp_oh = 0;
9915 if (bbr_include_ip_oh)
9916 bbr->r_ctl.rc_inc_ip_oh = 1;
9917 else
9918 bbr->r_ctl.rc_inc_ip_oh = 0;
9919 if (bbr_include_enet_oh)
9920 bbr->r_ctl.rc_inc_enet_oh = 1;
9921 else
9922 bbr->r_ctl.rc_inc_enet_oh = 0;
9923 bbr->r_ctl.rc_probertt_int = bbr_rtt_probe_limit;
9924 reset_time(&bbr->r_ctl.rc_delrate,
9925 bbr_num_pktepo_for_del_limit);
9926 reset_time_small(&bbr->r_ctl.rc_rttprop,
9927 (bbr_filter_len_sec * USECS_IN_SECOND));
9928 tcp_bbr_tso_size_check(bbr, tcp_get_usecs(&bbr->rc_tv));
9929 }
9930 /*
9931 * Return 0 on success, non-zero on failure
9932 * which indicates the error (usually no memory).
9933 */
9934 static int
bbr_init(struct tcpcb * tp,void ** ptr)9935 bbr_init(struct tcpcb *tp, void **ptr)
9936 {
9937 struct inpcb *inp = tptoinpcb(tp);
9938 struct tcp_bbr *bbr = NULL;
9939 uint32_t cts;
9940
9941 tcp_hpts_init(tp);
9942
9943 *ptr = uma_zalloc(bbr_pcb_zone, (M_NOWAIT | M_ZERO));
9944 if (*ptr == NULL) {
9945 /*
9946 * We need to allocate memory but cant. The INP and INP_INFO
9947 * locks and they are recursive (happens during setup. So a
9948 * scheme to drop the locks fails :(
9949 *
9950 */
9951 return (ENOMEM);
9952 }
9953 bbr = (struct tcp_bbr *)*ptr;
9954 bbr->rtt_valid = 0;
9955 tp->t_flags2 |= TF2_CANNOT_DO_ECN;
9956 tp->t_flags2 |= TF2_SUPPORTS_MBUFQ;
9957 /* Take off any undesired flags */
9958 tp->t_flags2 &= ~TF2_MBUF_QUEUE_READY;
9959 tp->t_flags2 &= ~TF2_DONT_SACK_QUEUE;
9960 tp->t_flags2 &= ~TF2_MBUF_ACKCMP;
9961 tp->t_flags2 &= ~TF2_MBUF_L_ACKS;
9962
9963 TAILQ_INIT(&bbr->r_ctl.rc_map);
9964 TAILQ_INIT(&bbr->r_ctl.rc_free);
9965 TAILQ_INIT(&bbr->r_ctl.rc_tmap);
9966 bbr->rc_tp = tp;
9967 bbr->rc_inp = inp;
9968 cts = tcp_get_usecs(&bbr->rc_tv);
9969 tp->t_acktime = 0;
9970 bbr->rc_allow_data_af_clo = bbr_ignore_data_after_close;
9971 bbr->r_ctl.rc_reorder_fade = bbr_reorder_fade;
9972 bbr->rc_tlp_threshold = bbr_tlp_thresh;
9973 bbr->r_ctl.rc_reorder_shift = bbr_reorder_thresh;
9974 bbr->r_ctl.rc_pkt_delay = bbr_pkt_delay;
9975 bbr->r_ctl.rc_min_to = bbr_min_to;
9976 bbr->rc_bbr_state = BBR_STATE_STARTUP;
9977 bbr->r_ctl.bbr_lost_at_state = 0;
9978 bbr->r_ctl.rc_lost_at_startup = 0;
9979 bbr->rc_all_timers_stopped = 0;
9980 bbr->r_ctl.rc_bbr_lastbtlbw = 0;
9981 bbr->r_ctl.rc_pkt_epoch_del = 0;
9982 bbr->r_ctl.rc_pkt_epoch = 0;
9983 bbr->r_ctl.rc_lowest_rtt = 0xffffffff;
9984 bbr->r_ctl.rc_bbr_hptsi_gain = bbr_high_gain;
9985 bbr->r_ctl.rc_bbr_cwnd_gain = bbr_high_gain;
9986 bbr->r_ctl.rc_went_idle_time = cts;
9987 bbr->rc_pacer_started = cts;
9988 bbr->r_ctl.rc_pkt_epoch_time = cts;
9989 bbr->r_ctl.rc_rcvtime = cts;
9990 bbr->r_ctl.rc_bbr_state_time = cts;
9991 bbr->r_ctl.rc_del_time = cts;
9992 bbr->r_ctl.rc_tlp_rxt_last_time = cts;
9993 bbr->r_ctl.last_in_probertt = cts;
9994 bbr->skip_gain = 0;
9995 bbr->gain_is_limited = 0;
9996 bbr->no_pacing_until = bbr_no_pacing_until;
9997 if (bbr->no_pacing_until)
9998 bbr->rc_no_pacing = 1;
9999 if (bbr_use_google_algo) {
10000 bbr->rc_no_pacing = 0;
10001 bbr->rc_use_google = 1;
10002 bbr->r_ctl.bbr_google_discount = bbr_google_discount;
10003 bbr->r_use_policer = bbr_policer_detection_enabled;
10004 } else {
10005 bbr->rc_use_google = 0;
10006 bbr->r_ctl.bbr_google_discount = 0;
10007 bbr->r_use_policer = 0;
10008 }
10009 if (bbr_ts_limiting)
10010 bbr->rc_use_ts_limit = 1;
10011 else
10012 bbr->rc_use_ts_limit = 0;
10013 if (bbr_ts_can_raise)
10014 bbr->ts_can_raise = 1;
10015 else
10016 bbr->ts_can_raise = 0;
10017 if (V_tcp_delack_enabled == 1)
10018 tp->t_delayed_ack = 2;
10019 else if (V_tcp_delack_enabled == 0)
10020 tp->t_delayed_ack = 0;
10021 else if (V_tcp_delack_enabled < 100)
10022 tp->t_delayed_ack = V_tcp_delack_enabled;
10023 else
10024 tp->t_delayed_ack = 2;
10025 if (bbr->rc_use_google == 0)
10026 bbr->r_ctl.rc_probertt_int = bbr_rtt_probe_limit;
10027 else
10028 bbr->r_ctl.rc_probertt_int = (USECS_IN_SECOND * 10);
10029 bbr->r_ctl.rc_min_rto_ms = bbr_rto_min_ms;
10030 bbr->rc_max_rto_sec = bbr_rto_max_sec;
10031 bbr->rc_init_win = bbr_def_init_win;
10032 if (tp->t_flags & TF_REQ_TSTMP)
10033 bbr->rc_last_options = TCP_TS_OVERHEAD;
10034 bbr->r_ctl.rc_pace_max_segs = tp->t_maxseg - bbr->rc_last_options;
10035 bbr->r_ctl.rc_high_rwnd = tp->snd_wnd;
10036 bbr->r_init_rtt = 1;
10037
10038 counter_u64_add(bbr_flows_nohdwr_pacing, 1);
10039 if (bbr_allow_hdwr_pacing)
10040 bbr->bbr_hdw_pace_ena = 1;
10041 else
10042 bbr->bbr_hdw_pace_ena = 0;
10043 if (bbr_sends_full_iwnd)
10044 bbr->bbr_init_win_cheat = 1;
10045 else
10046 bbr->bbr_init_win_cheat = 0;
10047 bbr->r_ctl.bbr_utter_max = bbr_hptsi_utter_max;
10048 bbr->r_ctl.rc_drain_pg = bbr_drain_gain;
10049 bbr->r_ctl.rc_startup_pg = bbr_high_gain;
10050 bbr->rc_loss_exit = bbr_exit_startup_at_loss;
10051 bbr->r_ctl.bbr_rttprobe_gain_val = bbr_rttprobe_gain;
10052 bbr->r_ctl.bbr_hptsi_per_second = bbr_hptsi_per_second;
10053 bbr->r_ctl.bbr_hptsi_segments_delay_tar = bbr_hptsi_segments_delay_tar;
10054 bbr->r_ctl.bbr_hptsi_segments_max = bbr_hptsi_segments_max;
10055 bbr->r_ctl.bbr_hptsi_segments_floor = bbr_hptsi_segments_floor;
10056 bbr->r_ctl.bbr_hptsi_bytes_min = bbr_hptsi_bytes_min;
10057 bbr->r_ctl.bbr_cross_over = bbr_cross_over;
10058 bbr->r_ctl.rc_rtt_shrinks = cts;
10059 if (bbr->rc_use_google) {
10060 setup_time_filter(&bbr->r_ctl.rc_delrate,
10061 FILTER_TYPE_MAX,
10062 BBR_NUM_RTTS_FOR_GOOG_DEL_LIMIT);
10063 setup_time_filter_small(&bbr->r_ctl.rc_rttprop,
10064 FILTER_TYPE_MIN, (11 * USECS_IN_SECOND));
10065 } else {
10066 setup_time_filter(&bbr->r_ctl.rc_delrate,
10067 FILTER_TYPE_MAX,
10068 bbr_num_pktepo_for_del_limit);
10069 setup_time_filter_small(&bbr->r_ctl.rc_rttprop,
10070 FILTER_TYPE_MIN, (bbr_filter_len_sec * USECS_IN_SECOND));
10071 }
10072 bbr_log_rtt_shrinks(bbr, cts, 0, 0, __LINE__, BBR_RTTS_INIT, 0);
10073 if (bbr_uses_idle_restart)
10074 bbr->rc_use_idle_restart = 1;
10075 else
10076 bbr->rc_use_idle_restart = 0;
10077 bbr->r_ctl.rc_bbr_cur_del_rate = 0;
10078 bbr->r_ctl.rc_initial_hptsi_bw = bbr_initial_bw_bps;
10079 if (bbr_resends_use_tso)
10080 bbr->rc_resends_use_tso = 1;
10081 if (tp->snd_una != tp->snd_max) {
10082 /* Create a send map for the current outstanding data */
10083 struct bbr_sendmap *rsm;
10084
10085 rsm = bbr_alloc(bbr);
10086 if (rsm == NULL) {
10087 uma_zfree(bbr_pcb_zone, *ptr);
10088 *ptr = NULL;
10089 return (ENOMEM);
10090 }
10091 rsm->r_rtt_not_allowed = 1;
10092 rsm->r_tim_lastsent[0] = cts;
10093 rsm->r_rtr_cnt = 1;
10094 rsm->r_rtr_bytes = 0;
10095 rsm->r_start = tp->snd_una;
10096 rsm->r_end = tp->snd_max;
10097 rsm->r_dupack = 0;
10098 rsm->r_delivered = bbr->r_ctl.rc_delivered;
10099 rsm->r_ts_valid = 0;
10100 rsm->r_del_ack_ts = tp->ts_recent;
10101 rsm->r_del_time = cts;
10102 if (bbr->r_ctl.r_app_limited_until)
10103 rsm->r_app_limited = 1;
10104 else
10105 rsm->r_app_limited = 0;
10106 TAILQ_INSERT_TAIL(&bbr->r_ctl.rc_map, rsm, r_next);
10107 TAILQ_INSERT_TAIL(&bbr->r_ctl.rc_tmap, rsm, r_tnext);
10108 rsm->r_in_tmap = 1;
10109 if (bbr->rc_bbr_state == BBR_STATE_PROBE_BW)
10110 rsm->r_bbr_state = bbr_state_val(bbr);
10111 else
10112 rsm->r_bbr_state = 8;
10113 }
10114 if (bbr_use_rack_resend_cheat && (bbr->rc_use_google == 0))
10115 bbr->bbr_use_rack_cheat = 1;
10116 if (bbr_incr_timers && (bbr->rc_use_google == 0))
10117 bbr->r_ctl.rc_incr_tmrs = 1;
10118 if (bbr_include_tcp_oh && (bbr->rc_use_google == 0))
10119 bbr->r_ctl.rc_inc_tcp_oh = 1;
10120 if (bbr_include_ip_oh && (bbr->rc_use_google == 0))
10121 bbr->r_ctl.rc_inc_ip_oh = 1;
10122 if (bbr_include_enet_oh && (bbr->rc_use_google == 0))
10123 bbr->r_ctl.rc_inc_enet_oh = 1;
10124
10125 bbr_log_type_statechange(bbr, cts, __LINE__);
10126 if (TCPS_HAVEESTABLISHED(tp->t_state) &&
10127 (tp->t_srtt)) {
10128 uint32_t rtt;
10129
10130 rtt = (TICKS_2_USEC(tp->t_srtt) >> TCP_RTT_SHIFT);
10131 apply_filter_min_small(&bbr->r_ctl.rc_rttprop, rtt, cts);
10132 }
10133 /* announce the settings and state */
10134 bbr_log_settings_change(bbr, BBR_RECOVERY_LOWRTT);
10135 tcp_bbr_tso_size_check(bbr, cts);
10136 /*
10137 * Now call the generic function to start a timer. This will place
10138 * the TCB on the hptsi wheel if a timer is needed with appropriate
10139 * flags.
10140 */
10141 bbr_stop_all_timers(tp, bbr);
10142 /*
10143 * Validate the timers are not in usec, if they are convert.
10144 * BBR should in theory move to USEC and get rid of a
10145 * lot of the TICKS_2 calls.. but for now we stay
10146 * with tick timers.
10147 */
10148 tcp_change_time_units(tp, TCP_TMR_GRANULARITY_TICKS);
10149 TCPT_RANGESET(tp->t_rxtcur,
10150 ((tp->t_srtt >> 2) + tp->t_rttvar) >> 1,
10151 tp->t_rttmin, tcp_rexmit_max);
10152 bbr_start_hpts_timer(bbr, tp, cts, 5, 0, 0);
10153 return (0);
10154 }
10155
10156 /*
10157 * Return 0 if we can accept the connection. Return
10158 * non-zero if we can't handle the connection. A EAGAIN
10159 * means you need to wait until the connection is up.
10160 * a EADDRNOTAVAIL means we can never handle the connection
10161 * (no SACK).
10162 */
10163 static int
bbr_handoff_ok(struct tcpcb * tp)10164 bbr_handoff_ok(struct tcpcb *tp)
10165 {
10166 if ((tp->t_state == TCPS_CLOSED) ||
10167 (tp->t_state == TCPS_LISTEN)) {
10168 /* Sure no problem though it may not stick */
10169 return (0);
10170 }
10171 if ((tp->t_state == TCPS_SYN_SENT) ||
10172 (tp->t_state == TCPS_SYN_RECEIVED)) {
10173 /*
10174 * We really don't know you have to get to ESTAB or beyond
10175 * to tell.
10176 */
10177 return (EAGAIN);
10178 }
10179 if (tp->t_flags & TF_SENTFIN)
10180 return (EINVAL);
10181 if ((tp->t_flags & TF_SACK_PERMIT) || bbr_sack_not_required) {
10182 return (0);
10183 }
10184 /*
10185 * If we reach here we don't do SACK on this connection so we can
10186 * never do rack.
10187 */
10188 return (EINVAL);
10189 }
10190
10191 static void
bbr_fini(struct tcpcb * tp,int32_t tcb_is_purged)10192 bbr_fini(struct tcpcb *tp, int32_t tcb_is_purged)
10193 {
10194 if (tp->t_fb_ptr) {
10195 uint32_t calc;
10196 struct tcp_bbr *bbr;
10197 struct bbr_sendmap *rsm;
10198
10199 bbr = (struct tcp_bbr *)tp->t_fb_ptr;
10200 if (bbr->r_ctl.crte)
10201 tcp_rel_pacing_rate(bbr->r_ctl.crte, bbr->rc_tp);
10202 bbr_log_flowend(bbr);
10203 bbr->rc_tp = NULL;
10204 if (bbr->bbr_hdrw_pacing)
10205 counter_u64_add(bbr_flows_whdwr_pacing, -1);
10206 else
10207 counter_u64_add(bbr_flows_nohdwr_pacing, -1);
10208 if (bbr->r_ctl.crte != NULL) {
10209 tcp_rel_pacing_rate(bbr->r_ctl.crte, tp);
10210 bbr->r_ctl.crte = NULL;
10211 }
10212 rsm = TAILQ_FIRST(&bbr->r_ctl.rc_map);
10213 while (rsm) {
10214 TAILQ_REMOVE(&bbr->r_ctl.rc_map, rsm, r_next);
10215 uma_zfree(bbr_zone, rsm);
10216 rsm = TAILQ_FIRST(&bbr->r_ctl.rc_map);
10217 }
10218 rsm = TAILQ_FIRST(&bbr->r_ctl.rc_free);
10219 while (rsm) {
10220 TAILQ_REMOVE(&bbr->r_ctl.rc_free, rsm, r_next);
10221 uma_zfree(bbr_zone, rsm);
10222 rsm = TAILQ_FIRST(&bbr->r_ctl.rc_free);
10223 }
10224 calc = bbr->r_ctl.rc_high_rwnd - bbr->r_ctl.rc_init_rwnd;
10225 if (calc > (bbr->r_ctl.rc_init_rwnd / 10))
10226 BBR_STAT_INC(bbr_dynamic_rwnd);
10227 else
10228 BBR_STAT_INC(bbr_static_rwnd);
10229 bbr->r_ctl.rc_free_cnt = 0;
10230 uma_zfree(bbr_pcb_zone, tp->t_fb_ptr);
10231 tp->t_fb_ptr = NULL;
10232 }
10233 /* Make sure snd_nxt is correctly set */
10234 tp->snd_nxt = tp->snd_max;
10235 }
10236
10237 static void
bbr_set_state(struct tcpcb * tp,struct tcp_bbr * bbr,uint32_t win)10238 bbr_set_state(struct tcpcb *tp, struct tcp_bbr *bbr, uint32_t win)
10239 {
10240 switch (tp->t_state) {
10241 case TCPS_SYN_SENT:
10242 bbr->r_state = TCPS_SYN_SENT;
10243 bbr->r_substate = bbr_do_syn_sent;
10244 break;
10245 case TCPS_SYN_RECEIVED:
10246 bbr->r_state = TCPS_SYN_RECEIVED;
10247 bbr->r_substate = bbr_do_syn_recv;
10248 break;
10249 case TCPS_ESTABLISHED:
10250 bbr->r_ctl.rc_init_rwnd = max(win, bbr->rc_tp->snd_wnd);
10251 bbr->r_state = TCPS_ESTABLISHED;
10252 bbr->r_substate = bbr_do_established;
10253 break;
10254 case TCPS_CLOSE_WAIT:
10255 bbr->r_state = TCPS_CLOSE_WAIT;
10256 bbr->r_substate = bbr_do_close_wait;
10257 break;
10258 case TCPS_FIN_WAIT_1:
10259 bbr->r_state = TCPS_FIN_WAIT_1;
10260 bbr->r_substate = bbr_do_fin_wait_1;
10261 break;
10262 case TCPS_CLOSING:
10263 bbr->r_state = TCPS_CLOSING;
10264 bbr->r_substate = bbr_do_closing;
10265 break;
10266 case TCPS_LAST_ACK:
10267 bbr->r_state = TCPS_LAST_ACK;
10268 bbr->r_substate = bbr_do_lastack;
10269 break;
10270 case TCPS_FIN_WAIT_2:
10271 bbr->r_state = TCPS_FIN_WAIT_2;
10272 bbr->r_substate = bbr_do_fin_wait_2;
10273 break;
10274 case TCPS_LISTEN:
10275 case TCPS_CLOSED:
10276 case TCPS_TIME_WAIT:
10277 default:
10278 break;
10279 };
10280 }
10281
10282 static void
bbr_substate_change(struct tcp_bbr * bbr,uint32_t cts,int32_t line,int dolog)10283 bbr_substate_change(struct tcp_bbr *bbr, uint32_t cts, int32_t line, int dolog)
10284 {
10285 /*
10286 * Now what state are we going into now? Is there adjustments
10287 * needed?
10288 */
10289 int32_t old_state;
10290
10291 old_state = bbr_state_val(bbr);
10292 if (bbr_state_val(bbr) == BBR_SUB_LEVEL1) {
10293 /* Save the lowest srtt we saw in our end of the sub-state */
10294 bbr->rc_hit_state_1 = 0;
10295 if (bbr->r_ctl.bbr_smallest_srtt_this_state != 0xffffffff)
10296 bbr->r_ctl.bbr_smallest_srtt_state2 = bbr->r_ctl.bbr_smallest_srtt_this_state;
10297 }
10298 bbr->rc_bbr_substate++;
10299 if (bbr_state_val(bbr) == BBR_SUB_GAIN) {
10300 /*
10301 * We enter the gain(5/4) cycle (possibly less if
10302 * shallow buffer detection is enabled)
10303 */
10304 if (bbr->skip_gain) {
10305 /*
10306 * Hardware pacing has set our rate to
10307 * the max and limited our b/w just
10308 * do level i.e. no gain.
10309 */
10310 bbr->r_ctl.rc_bbr_hptsi_gain = bbr_hptsi_gain[BBR_SUB_LEVEL1];
10311 } else if (bbr->gain_is_limited &&
10312 bbr->bbr_hdrw_pacing &&
10313 bbr->r_ctl.crte) {
10314 /*
10315 * We can't gain above the hardware pacing
10316 * rate which is less than our rate + the gain
10317 * calculate the gain needed to reach the hardware
10318 * pacing rate..
10319 */
10320 uint64_t bw, rate, gain_calc;
10321
10322 bw = bbr_get_bw(bbr);
10323 rate = bbr->r_ctl.crte->rate;
10324 if ((rate > bw) &&
10325 (((bw * (uint64_t)bbr_hptsi_gain[BBR_SUB_GAIN]) / (uint64_t)BBR_UNIT) > rate)) {
10326 gain_calc = (rate * BBR_UNIT) / bw;
10327 if (gain_calc < BBR_UNIT)
10328 gain_calc = BBR_UNIT;
10329 bbr->r_ctl.rc_bbr_hptsi_gain = (uint16_t)gain_calc;
10330 } else {
10331 bbr->r_ctl.rc_bbr_hptsi_gain = bbr_hptsi_gain[BBR_SUB_GAIN];
10332 }
10333 } else
10334 bbr->r_ctl.rc_bbr_hptsi_gain = bbr_hptsi_gain[BBR_SUB_GAIN];
10335 if ((bbr->rc_use_google == 0) && (bbr_gain_to_target == 0)) {
10336 bbr->r_ctl.rc_bbr_state_atflight = cts;
10337 } else
10338 bbr->r_ctl.rc_bbr_state_atflight = 0;
10339 } else if (bbr_state_val(bbr) == BBR_SUB_DRAIN) {
10340 bbr->rc_hit_state_1 = 1;
10341 bbr->r_ctl.rc_exta_time_gd = 0;
10342 bbr->r_ctl.flightsize_at_drain = ctf_flight_size(bbr->rc_tp,
10343 (bbr->r_ctl.rc_sacked + bbr->r_ctl.rc_lost_bytes));
10344 if (bbr_state_drain_2_tar) {
10345 bbr->r_ctl.rc_bbr_state_atflight = 0;
10346 } else
10347 bbr->r_ctl.rc_bbr_state_atflight = cts;
10348 bbr->r_ctl.rc_bbr_hptsi_gain = bbr_hptsi_gain[BBR_SUB_DRAIN];
10349 } else {
10350 /* All other cycles hit here 2-7 */
10351 if ((old_state == BBR_SUB_DRAIN) && bbr->rc_hit_state_1) {
10352 if (bbr_sub_drain_slam_cwnd &&
10353 (bbr->rc_use_google == 0) &&
10354 (bbr->rc_tp->snd_cwnd < bbr->r_ctl.rc_saved_cwnd)) {
10355 bbr->rc_tp->snd_cwnd = bbr->r_ctl.rc_saved_cwnd;
10356 bbr_log_type_cwndupd(bbr, 0, 0, 0, 12, 0, 0, __LINE__);
10357 }
10358 if ((cts - bbr->r_ctl.rc_bbr_state_time) > bbr_get_rtt(bbr, BBR_RTT_PROP))
10359 bbr->r_ctl.rc_exta_time_gd += ((cts - bbr->r_ctl.rc_bbr_state_time) -
10360 bbr_get_rtt(bbr, BBR_RTT_PROP));
10361 else
10362 bbr->r_ctl.rc_exta_time_gd = 0;
10363 if (bbr->r_ctl.rc_exta_time_gd) {
10364 bbr->r_ctl.rc_level_state_extra = bbr->r_ctl.rc_exta_time_gd;
10365 /* Now chop up the time for each state (div by 7) */
10366 bbr->r_ctl.rc_level_state_extra /= 7;
10367 if (bbr_rand_ot && bbr->r_ctl.rc_level_state_extra) {
10368 /* Add a randomization */
10369 bbr_randomize_extra_state_time(bbr);
10370 }
10371 }
10372 }
10373 bbr->r_ctl.rc_bbr_state_atflight = max(1, cts);
10374 bbr->r_ctl.rc_bbr_hptsi_gain = bbr_hptsi_gain[bbr_state_val(bbr)];
10375 }
10376 if (bbr->rc_use_google) {
10377 bbr->r_ctl.rc_bbr_state_atflight = max(1, cts);
10378 }
10379 bbr->r_ctl.bbr_lost_at_state = bbr->r_ctl.rc_lost;
10380 bbr->r_ctl.rc_bbr_cwnd_gain = bbr_cwnd_gain;
10381 if (dolog)
10382 bbr_log_type_statechange(bbr, cts, line);
10383
10384 if (SEQ_GT(cts, bbr->r_ctl.rc_bbr_state_time)) {
10385 uint32_t time_in;
10386
10387 time_in = cts - bbr->r_ctl.rc_bbr_state_time;
10388 if (bbr->rc_bbr_state == BBR_STATE_PROBE_BW) {
10389 counter_u64_add(bbr_state_time[(old_state + 5)], time_in);
10390 } else {
10391 counter_u64_add(bbr_state_time[bbr->rc_bbr_state], time_in);
10392 }
10393 }
10394 bbr->r_ctl.bbr_smallest_srtt_this_state = 0xffffffff;
10395 bbr_set_state_target(bbr, __LINE__);
10396 if (bbr_sub_drain_slam_cwnd &&
10397 (bbr->rc_use_google == 0) &&
10398 (bbr_state_val(bbr) == BBR_SUB_DRAIN)) {
10399 /* Slam down the cwnd */
10400 bbr->r_ctl.rc_saved_cwnd = bbr->rc_tp->snd_cwnd;
10401 bbr->rc_tp->snd_cwnd = bbr->r_ctl.rc_target_at_state;
10402 if (bbr_sub_drain_app_limit) {
10403 /* Go app limited if we are on a long drain */
10404 bbr->r_ctl.r_app_limited_until = (bbr->r_ctl.rc_delivered +
10405 ctf_flight_size(bbr->rc_tp,
10406 (bbr->r_ctl.rc_sacked +
10407 bbr->r_ctl.rc_lost_bytes)));
10408 }
10409 bbr_log_type_cwndupd(bbr, 0, 0, 0, 12, 0, 0, __LINE__);
10410 }
10411 if (bbr->rc_lt_use_bw) {
10412 /* In policed mode we clamp pacing_gain to BBR_UNIT */
10413 bbr->r_ctl.rc_bbr_hptsi_gain = BBR_UNIT;
10414 }
10415 /* Google changes TSO size every cycle */
10416 if (bbr->rc_use_google)
10417 tcp_bbr_tso_size_check(bbr, cts);
10418 bbr->r_ctl.gain_epoch = cts;
10419 bbr->r_ctl.rc_bbr_state_time = cts;
10420 bbr->r_ctl.substate_pe = bbr->r_ctl.rc_pkt_epoch;
10421 }
10422
10423 static void
bbr_set_probebw_google_gains(struct tcp_bbr * bbr,uint32_t cts,uint32_t losses)10424 bbr_set_probebw_google_gains(struct tcp_bbr *bbr, uint32_t cts, uint32_t losses)
10425 {
10426 if ((bbr_state_val(bbr) == BBR_SUB_DRAIN) &&
10427 (google_allow_early_out == 1) &&
10428 (bbr->r_ctl.rc_flight_at_input <= bbr->r_ctl.rc_target_at_state)) {
10429 /* We have reached out target flight size possibly early */
10430 goto change_state;
10431 }
10432 if (TSTMP_LT(cts, bbr->r_ctl.rc_bbr_state_time)) {
10433 return;
10434 }
10435 if ((cts - bbr->r_ctl.rc_bbr_state_time) < bbr_get_rtt(bbr, BBR_RTT_PROP)) {
10436 /*
10437 * Must be a rttProp movement forward before
10438 * we can change states.
10439 */
10440 return;
10441 }
10442 if (bbr_state_val(bbr) == BBR_SUB_GAIN) {
10443 /*
10444 * The needed time has passed but for
10445 * the gain cycle extra rules apply:
10446 * 1) If we have seen loss, we exit
10447 * 2) If we have not reached the target
10448 * we stay in GAIN (gain-to-target).
10449 */
10450 if (google_consider_lost && losses)
10451 goto change_state;
10452 if (bbr->r_ctl.rc_target_at_state > bbr->r_ctl.rc_flight_at_input) {
10453 return;
10454 }
10455 }
10456 change_state:
10457 /* For gain we must reach our target, all others last 1 rttProp */
10458 bbr_substate_change(bbr, cts, __LINE__, 1);
10459 }
10460
10461 static void
bbr_set_probebw_gains(struct tcp_bbr * bbr,uint32_t cts,uint32_t losses)10462 bbr_set_probebw_gains(struct tcp_bbr *bbr, uint32_t cts, uint32_t losses)
10463 {
10464 uint32_t flight, bbr_cur_cycle_time;
10465
10466 if (bbr->rc_use_google) {
10467 bbr_set_probebw_google_gains(bbr, cts, losses);
10468 return;
10469 }
10470 if (cts == 0) {
10471 /*
10472 * Never alow cts to be 0 we
10473 * do this so we can judge if
10474 * we have set a timestamp.
10475 */
10476 cts = 1;
10477 }
10478 if (bbr_state_is_pkt_epoch)
10479 bbr_cur_cycle_time = bbr_get_rtt(bbr, BBR_RTT_PKTRTT);
10480 else
10481 bbr_cur_cycle_time = bbr_get_rtt(bbr, BBR_RTT_PROP);
10482
10483 if (bbr->r_ctl.rc_bbr_state_atflight == 0) {
10484 if (bbr_state_val(bbr) == BBR_SUB_DRAIN) {
10485 flight = ctf_flight_size(bbr->rc_tp,
10486 (bbr->r_ctl.rc_sacked + bbr->r_ctl.rc_lost_bytes));
10487 if (bbr_sub_drain_slam_cwnd && bbr->rc_hit_state_1) {
10488 /* Keep it slam down */
10489 if (bbr->rc_tp->snd_cwnd > bbr->r_ctl.rc_target_at_state) {
10490 bbr->rc_tp->snd_cwnd = bbr->r_ctl.rc_target_at_state;
10491 bbr_log_type_cwndupd(bbr, 0, 0, 0, 12, 0, 0, __LINE__);
10492 }
10493 if (bbr_sub_drain_app_limit) {
10494 /* Go app limited if we are on a long drain */
10495 bbr->r_ctl.r_app_limited_until = (bbr->r_ctl.rc_delivered + flight);
10496 }
10497 }
10498 if (TSTMP_GT(cts, bbr->r_ctl.gain_epoch) &&
10499 (((cts - bbr->r_ctl.gain_epoch) > bbr_get_rtt(bbr, BBR_RTT_PROP)) ||
10500 (flight >= bbr->r_ctl.flightsize_at_drain))) {
10501 /*
10502 * Still here after the same time as
10503 * the gain. We need to drain harder
10504 * for the next srtt. Reduce by a set amount
10505 * the gain drop is capped at DRAIN states
10506 * value (88).
10507 */
10508 bbr->r_ctl.flightsize_at_drain = flight;
10509 if (bbr_drain_drop_mul &&
10510 bbr_drain_drop_div &&
10511 (bbr_drain_drop_mul < bbr_drain_drop_div)) {
10512 /* Use your specific drop value (def 4/5 = 20%) */
10513 bbr->r_ctl.rc_bbr_hptsi_gain *= bbr_drain_drop_mul;
10514 bbr->r_ctl.rc_bbr_hptsi_gain /= bbr_drain_drop_div;
10515 } else {
10516 /* You get drop of 20% */
10517 bbr->r_ctl.rc_bbr_hptsi_gain *= 4;
10518 bbr->r_ctl.rc_bbr_hptsi_gain /= 5;
10519 }
10520 if (bbr->r_ctl.rc_bbr_hptsi_gain <= bbr_drain_floor) {
10521 /* Reduce our gain again to the bottom */
10522 bbr->r_ctl.rc_bbr_hptsi_gain = max(bbr_drain_floor, 1);
10523 }
10524 bbr_log_exit_gain(bbr, cts, 4);
10525 /*
10526 * Extend out so we wait another
10527 * epoch before dropping again.
10528 */
10529 bbr->r_ctl.gain_epoch = cts;
10530 }
10531 if (flight <= bbr->r_ctl.rc_target_at_state) {
10532 if (bbr_sub_drain_slam_cwnd &&
10533 (bbr->rc_use_google == 0) &&
10534 (bbr->rc_tp->snd_cwnd < bbr->r_ctl.rc_saved_cwnd)) {
10535 bbr->rc_tp->snd_cwnd = bbr->r_ctl.rc_saved_cwnd;
10536 bbr_log_type_cwndupd(bbr, 0, 0, 0, 12, 0, 0, __LINE__);
10537 }
10538 bbr->r_ctl.rc_bbr_state_atflight = max(cts, 1);
10539 bbr_log_exit_gain(bbr, cts, 3);
10540 }
10541 } else {
10542 /* Its a gain */
10543 if (bbr->r_ctl.rc_lost > bbr->r_ctl.bbr_lost_at_state) {
10544 bbr->r_ctl.rc_bbr_state_atflight = max(cts, 1);
10545 goto change_state;
10546 }
10547 if ((ctf_outstanding(bbr->rc_tp) >= bbr->r_ctl.rc_target_at_state) ||
10548 ((ctf_outstanding(bbr->rc_tp) + bbr->rc_tp->t_maxseg - 1) >=
10549 bbr->rc_tp->snd_wnd)) {
10550 bbr->r_ctl.rc_bbr_state_atflight = max(cts, 1);
10551 bbr_log_exit_gain(bbr, cts, 2);
10552 }
10553 }
10554 /**
10555 * We fall through and return always one of two things has
10556 * occurred.
10557 * 1) We are still not at target
10558 * <or>
10559 * 2) We reached the target and set rc_bbr_state_atflight
10560 * which means we no longer hit this block
10561 * next time we are called.
10562 */
10563 return;
10564 }
10565 change_state:
10566 if (TSTMP_LT(cts, bbr->r_ctl.rc_bbr_state_time))
10567 return;
10568 if ((cts - bbr->r_ctl.rc_bbr_state_time) < bbr_cur_cycle_time) {
10569 /* Less than a full time-period has passed */
10570 return;
10571 }
10572 if (bbr->r_ctl.rc_level_state_extra &&
10573 (bbr_state_val(bbr) > BBR_SUB_DRAIN) &&
10574 ((cts - bbr->r_ctl.rc_bbr_state_time) <
10575 (bbr_cur_cycle_time + bbr->r_ctl.rc_level_state_extra))) {
10576 /* Less than a full time-period + extra has passed */
10577 return;
10578 }
10579 if (bbr_gain_gets_extra_too &&
10580 bbr->r_ctl.rc_level_state_extra &&
10581 (bbr_state_val(bbr) == BBR_SUB_GAIN) &&
10582 ((cts - bbr->r_ctl.rc_bbr_state_time) <
10583 (bbr_cur_cycle_time + bbr->r_ctl.rc_level_state_extra))) {
10584 /* Less than a full time-period + extra has passed */
10585 return;
10586 }
10587 bbr_substate_change(bbr, cts, __LINE__, 1);
10588 }
10589
10590 static uint32_t
bbr_get_a_state_target(struct tcp_bbr * bbr,uint32_t gain)10591 bbr_get_a_state_target(struct tcp_bbr *bbr, uint32_t gain)
10592 {
10593 uint32_t mss, tar;
10594
10595 if (bbr->rc_use_google) {
10596 /* Google just uses the cwnd target */
10597 tar = bbr_get_target_cwnd(bbr, bbr_get_bw(bbr), gain);
10598 } else {
10599 mss = min((bbr->rc_tp->t_maxseg - bbr->rc_last_options),
10600 bbr->r_ctl.rc_pace_max_segs);
10601 /* Get the base cwnd with gain rounded to a mss */
10602 tar = roundup(bbr_get_raw_target_cwnd(bbr, bbr_get_bw(bbr),
10603 gain), mss);
10604 /* Make sure it is within our min */
10605 if (tar < get_min_cwnd(bbr))
10606 return (get_min_cwnd(bbr));
10607 }
10608 return (tar);
10609 }
10610
10611 static void
bbr_set_state_target(struct tcp_bbr * bbr,int line)10612 bbr_set_state_target(struct tcp_bbr *bbr, int line)
10613 {
10614 uint32_t tar, meth;
10615
10616 if ((bbr->rc_bbr_state == BBR_STATE_PROBE_RTT) &&
10617 ((bbr->r_ctl.bbr_rttprobe_gain_val == 0) || bbr->rc_use_google)) {
10618 /* Special case using old probe-rtt method */
10619 tar = bbr_rtt_probe_cwndtarg * (bbr->rc_tp->t_maxseg - bbr->rc_last_options);
10620 meth = 1;
10621 } else {
10622 /* Non-probe-rtt case and reduced probe-rtt */
10623 if ((bbr->rc_bbr_state == BBR_STATE_PROBE_BW) &&
10624 (bbr->r_ctl.rc_bbr_hptsi_gain > BBR_UNIT)) {
10625 /* For gain cycle we use the hptsi gain */
10626 tar = bbr_get_a_state_target(bbr, bbr->r_ctl.rc_bbr_hptsi_gain);
10627 meth = 2;
10628 } else if ((bbr_target_is_bbunit) || bbr->rc_use_google) {
10629 /*
10630 * If configured, or for google all other states
10631 * get BBR_UNIT.
10632 */
10633 tar = bbr_get_a_state_target(bbr, BBR_UNIT);
10634 meth = 3;
10635 } else {
10636 /*
10637 * Or we set a target based on the pacing gain
10638 * for non-google mode and default (non-configured).
10639 * Note we don't set a target goal below drain (192).
10640 */
10641 if (bbr->r_ctl.rc_bbr_hptsi_gain < bbr_hptsi_gain[BBR_SUB_DRAIN]) {
10642 tar = bbr_get_a_state_target(bbr, bbr_hptsi_gain[BBR_SUB_DRAIN]);
10643 meth = 4;
10644 } else {
10645 tar = bbr_get_a_state_target(bbr, bbr->r_ctl.rc_bbr_hptsi_gain);
10646 meth = 5;
10647 }
10648 }
10649 }
10650 bbr_log_set_of_state_target(bbr, tar, line, meth);
10651 bbr->r_ctl.rc_target_at_state = tar;
10652 }
10653
10654 static void
bbr_enter_probe_rtt(struct tcp_bbr * bbr,uint32_t cts,int32_t line)10655 bbr_enter_probe_rtt(struct tcp_bbr *bbr, uint32_t cts, int32_t line)
10656 {
10657 /* Change to probe_rtt */
10658 uint32_t time_in;
10659
10660 bbr->r_ctl.bbr_lost_at_state = bbr->r_ctl.rc_lost;
10661 bbr->r_ctl.flightsize_at_drain = ctf_flight_size(bbr->rc_tp,
10662 (bbr->r_ctl.rc_sacked + bbr->r_ctl.rc_lost_bytes));
10663 bbr->r_ctl.r_app_limited_until = (bbr->r_ctl.flightsize_at_drain
10664 + bbr->r_ctl.rc_delivered);
10665 /* Setup so we force feed the filter */
10666 if (bbr->rc_use_google || bbr_probertt_sets_rtt)
10667 bbr->rc_prtt_set_ts = 1;
10668 if (SEQ_GT(cts, bbr->r_ctl.rc_bbr_state_time)) {
10669 time_in = cts - bbr->r_ctl.rc_bbr_state_time;
10670 counter_u64_add(bbr_state_time[bbr->rc_bbr_state], time_in);
10671 }
10672 bbr_log_rtt_shrinks(bbr, cts, 0, 0, __LINE__, BBR_RTTS_ENTERPROBE, 0);
10673 bbr->r_ctl.rc_rtt_shrinks = cts;
10674 bbr->r_ctl.last_in_probertt = cts;
10675 bbr->r_ctl.rc_probertt_srttchktim = cts;
10676 bbr->r_ctl.rc_bbr_state_time = cts;
10677 bbr->rc_bbr_state = BBR_STATE_PROBE_RTT;
10678 /* We need to force the filter to update */
10679
10680 if ((bbr_sub_drain_slam_cwnd) &&
10681 bbr->rc_hit_state_1 &&
10682 (bbr->rc_use_google == 0) &&
10683 (bbr_state_val(bbr) == BBR_SUB_DRAIN)) {
10684 if (bbr->rc_tp->snd_cwnd > bbr->r_ctl.rc_saved_cwnd)
10685 bbr->r_ctl.rc_saved_cwnd = bbr->rc_tp->snd_cwnd;
10686 } else
10687 bbr->r_ctl.rc_saved_cwnd = bbr->rc_tp->snd_cwnd;
10688 /* Update the lost */
10689 bbr->r_ctl.rc_lost_at_startup = bbr->r_ctl.rc_lost;
10690 if ((bbr->r_ctl.bbr_rttprobe_gain_val == 0) || bbr->rc_use_google){
10691 /* Set to the non-configurable default of 4 (PROBE_RTT_MIN) */
10692 bbr->rc_tp->snd_cwnd = bbr_rtt_probe_cwndtarg * (bbr->rc_tp->t_maxseg - bbr->rc_last_options);
10693 bbr_log_type_cwndupd(bbr, 0, 0, 0, 12, 0, 0, __LINE__);
10694 bbr->r_ctl.rc_bbr_hptsi_gain = BBR_UNIT;
10695 bbr->r_ctl.rc_bbr_cwnd_gain = BBR_UNIT;
10696 bbr_log_set_of_state_target(bbr, bbr->rc_tp->snd_cwnd, __LINE__, 6);
10697 bbr->r_ctl.rc_target_at_state = bbr->rc_tp->snd_cwnd;
10698 } else {
10699 /*
10700 * We bring it down slowly by using a hptsi gain that is
10701 * probably 75%. This will slowly float down our outstanding
10702 * without tampering with the cwnd.
10703 */
10704 bbr->r_ctl.rc_bbr_hptsi_gain = bbr->r_ctl.bbr_rttprobe_gain_val;
10705 bbr->r_ctl.rc_bbr_cwnd_gain = BBR_UNIT;
10706 bbr_set_state_target(bbr, __LINE__);
10707 if (bbr_prtt_slam_cwnd &&
10708 (bbr->rc_tp->snd_cwnd > bbr->r_ctl.rc_target_at_state)) {
10709 bbr->rc_tp->snd_cwnd = bbr->r_ctl.rc_target_at_state;
10710 bbr_log_type_cwndupd(bbr, 0, 0, 0, 12, 0, 0, __LINE__);
10711 }
10712 }
10713 if (ctf_flight_size(bbr->rc_tp,
10714 (bbr->r_ctl.rc_sacked + bbr->r_ctl.rc_lost_bytes)) <=
10715 bbr->r_ctl.rc_target_at_state) {
10716 /* We are at target */
10717 bbr->r_ctl.rc_bbr_enters_probertt = cts;
10718 } else {
10719 /* We need to come down to reach target before our time begins */
10720 bbr->r_ctl.rc_bbr_enters_probertt = 0;
10721 }
10722 bbr->r_ctl.rc_pe_of_prtt = bbr->r_ctl.rc_pkt_epoch;
10723 BBR_STAT_INC(bbr_enter_probertt);
10724 bbr_log_exit_gain(bbr, cts, 0);
10725 bbr_log_type_statechange(bbr, cts, line);
10726 }
10727
10728 static void
bbr_check_probe_rtt_limits(struct tcp_bbr * bbr,uint32_t cts)10729 bbr_check_probe_rtt_limits(struct tcp_bbr *bbr, uint32_t cts)
10730 {
10731 /*
10732 * Sanity check on probe-rtt intervals.
10733 * In crazy situations where we are competing
10734 * against new-reno flows with huge buffers
10735 * our rtt-prop interval could come to dominate
10736 * things if we can't get through a full set
10737 * of cycles, we need to adjust it.
10738 */
10739 if (bbr_can_adjust_probertt &&
10740 (bbr->rc_use_google == 0)) {
10741 uint16_t val = 0;
10742 uint32_t cur_rttp, fval, newval, baseval;
10743
10744 /* Are we to small and go into probe-rtt to often? */
10745 baseval = (bbr_get_rtt(bbr, BBR_RTT_PROP) * (BBR_SUBSTATE_COUNT + 1));
10746 cur_rttp = roundup(baseval, USECS_IN_SECOND);
10747 fval = bbr_filter_len_sec * USECS_IN_SECOND;
10748 if (bbr_is_ratio == 0) {
10749 if (fval > bbr_rtt_probe_limit)
10750 newval = cur_rttp + (fval - bbr_rtt_probe_limit);
10751 else
10752 newval = cur_rttp;
10753 } else {
10754 int mul;
10755
10756 mul = fval / bbr_rtt_probe_limit;
10757 newval = cur_rttp * mul;
10758 }
10759 if (cur_rttp > bbr->r_ctl.rc_probertt_int) {
10760 bbr->r_ctl.rc_probertt_int = cur_rttp;
10761 reset_time_small(&bbr->r_ctl.rc_rttprop, newval);
10762 val = 1;
10763 } else {
10764 /*
10765 * No adjustments were made
10766 * do we need to shrink it?
10767 */
10768 if (bbr->r_ctl.rc_probertt_int > bbr_rtt_probe_limit) {
10769 if (cur_rttp <= bbr_rtt_probe_limit) {
10770 /*
10771 * Things have calmed down lets
10772 * shrink all the way to default
10773 */
10774 bbr->r_ctl.rc_probertt_int = bbr_rtt_probe_limit;
10775 reset_time_small(&bbr->r_ctl.rc_rttprop,
10776 (bbr_filter_len_sec * USECS_IN_SECOND));
10777 cur_rttp = bbr_rtt_probe_limit;
10778 newval = (bbr_filter_len_sec * USECS_IN_SECOND);
10779 val = 2;
10780 } else {
10781 /*
10782 * Well does some adjustment make sense?
10783 */
10784 if (cur_rttp < bbr->r_ctl.rc_probertt_int) {
10785 /* We can reduce interval time some */
10786 bbr->r_ctl.rc_probertt_int = cur_rttp;
10787 reset_time_small(&bbr->r_ctl.rc_rttprop, newval);
10788 val = 3;
10789 }
10790 }
10791 }
10792 }
10793 if (val)
10794 bbr_log_rtt_shrinks(bbr, cts, cur_rttp, newval, __LINE__, BBR_RTTS_RESETS_VALUES, val);
10795 }
10796 }
10797
10798 static void
bbr_exit_probe_rtt(struct tcpcb * tp,struct tcp_bbr * bbr,uint32_t cts)10799 bbr_exit_probe_rtt(struct tcpcb *tp, struct tcp_bbr *bbr, uint32_t cts)
10800 {
10801 /* Exit probe-rtt */
10802
10803 if (tp->snd_cwnd < bbr->r_ctl.rc_saved_cwnd) {
10804 tp->snd_cwnd = bbr->r_ctl.rc_saved_cwnd;
10805 bbr_log_type_cwndupd(bbr, 0, 0, 0, 12, 0, 0, __LINE__);
10806 }
10807 bbr_log_exit_gain(bbr, cts, 1);
10808 bbr->rc_hit_state_1 = 0;
10809 bbr->r_ctl.rc_rtt_shrinks = cts;
10810 bbr->r_ctl.last_in_probertt = cts;
10811 bbr_log_rtt_shrinks(bbr, cts, 0, 0, __LINE__, BBR_RTTS_RTTPROBE, 0);
10812 bbr->r_ctl.bbr_lost_at_state = bbr->r_ctl.rc_lost;
10813 bbr->r_ctl.r_app_limited_until = (ctf_flight_size(tp,
10814 (bbr->r_ctl.rc_sacked + bbr->r_ctl.rc_lost_bytes)) +
10815 bbr->r_ctl.rc_delivered);
10816 if (SEQ_GT(cts, bbr->r_ctl.rc_bbr_state_time)) {
10817 uint32_t time_in;
10818
10819 time_in = cts - bbr->r_ctl.rc_bbr_state_time;
10820 counter_u64_add(bbr_state_time[bbr->rc_bbr_state], time_in);
10821 }
10822 if (bbr->rc_filled_pipe) {
10823 /* Switch to probe_bw */
10824 bbr->rc_bbr_state = BBR_STATE_PROBE_BW;
10825 bbr->rc_bbr_substate = bbr_pick_probebw_substate(bbr, cts);
10826 bbr->r_ctl.rc_bbr_cwnd_gain = bbr_cwnd_gain;
10827 bbr_substate_change(bbr, cts, __LINE__, 0);
10828 bbr_log_type_statechange(bbr, cts, __LINE__);
10829 } else {
10830 /* Back to startup */
10831 bbr->rc_bbr_state = BBR_STATE_STARTUP;
10832 bbr->r_ctl.rc_bbr_state_time = cts;
10833 /*
10834 * We don't want to give a complete free 3
10835 * measurements until we exit, so we use
10836 * the number of pe's we were in probe-rtt
10837 * to add to the startup_epoch. That way
10838 * we will still retain the old state.
10839 */
10840 bbr->r_ctl.rc_bbr_last_startup_epoch += (bbr->r_ctl.rc_pkt_epoch - bbr->r_ctl.rc_pe_of_prtt);
10841 bbr->r_ctl.rc_lost_at_startup = bbr->r_ctl.rc_lost;
10842 /* Make sure to use the lower pg when shifting back in */
10843 if (bbr->r_ctl.rc_lost &&
10844 bbr_use_lower_gain_in_startup &&
10845 (bbr->rc_use_google == 0))
10846 bbr->r_ctl.rc_bbr_hptsi_gain = bbr_startup_lower;
10847 else
10848 bbr->r_ctl.rc_bbr_hptsi_gain = bbr->r_ctl.rc_startup_pg;
10849 bbr->r_ctl.rc_bbr_cwnd_gain = bbr->r_ctl.rc_startup_pg;
10850 /* Probably not needed but set it anyway */
10851 bbr_set_state_target(bbr, __LINE__);
10852 bbr_log_type_statechange(bbr, cts, __LINE__);
10853 bbr_log_startup_event(bbr, cts, bbr->r_ctl.rc_bbr_last_startup_epoch,
10854 bbr->r_ctl.rc_lost_at_startup, bbr_start_exit, 0);
10855 }
10856 bbr_check_probe_rtt_limits(bbr, cts);
10857 }
10858
10859 static int32_t inline
bbr_should_enter_probe_rtt(struct tcp_bbr * bbr,uint32_t cts)10860 bbr_should_enter_probe_rtt(struct tcp_bbr *bbr, uint32_t cts)
10861 {
10862 if ((bbr->rc_past_init_win == 1) &&
10863 (bbr->rc_in_persist == 0) &&
10864 (bbr_calc_time(cts, bbr->r_ctl.rc_rtt_shrinks) >= bbr->r_ctl.rc_probertt_int)) {
10865 return (1);
10866 }
10867 if (bbr_can_force_probertt &&
10868 (bbr->rc_in_persist == 0) &&
10869 (TSTMP_GT(cts, bbr->r_ctl.last_in_probertt)) &&
10870 ((cts - bbr->r_ctl.last_in_probertt) > bbr->r_ctl.rc_probertt_int)) {
10871 return (1);
10872 }
10873 return (0);
10874 }
10875
10876 static int32_t
bbr_google_startup(struct tcp_bbr * bbr,uint32_t cts,int32_t pkt_epoch)10877 bbr_google_startup(struct tcp_bbr *bbr, uint32_t cts, int32_t pkt_epoch)
10878 {
10879 uint64_t btlbw, gain;
10880 if (pkt_epoch == 0) {
10881 /*
10882 * Need to be on a pkt-epoch to continue.
10883 */
10884 return (0);
10885 }
10886 btlbw = bbr_get_full_bw(bbr);
10887 gain = ((bbr->r_ctl.rc_bbr_lastbtlbw *
10888 (uint64_t)bbr_start_exit) / (uint64_t)100) + bbr->r_ctl.rc_bbr_lastbtlbw;
10889 if (btlbw >= gain) {
10890 bbr->r_ctl.rc_bbr_last_startup_epoch = bbr->r_ctl.rc_pkt_epoch;
10891 bbr_log_startup_event(bbr, cts, bbr->r_ctl.rc_bbr_last_startup_epoch,
10892 bbr->r_ctl.rc_lost_at_startup, bbr_start_exit, 3);
10893 bbr->r_ctl.rc_bbr_lastbtlbw = btlbw;
10894 }
10895 if ((bbr->r_ctl.rc_pkt_epoch - bbr->r_ctl.rc_bbr_last_startup_epoch) >= BBR_STARTUP_EPOCHS)
10896 return (1);
10897 bbr_log_startup_event(bbr, cts, bbr->r_ctl.rc_bbr_last_startup_epoch,
10898 bbr->r_ctl.rc_lost_at_startup, bbr_start_exit, 8);
10899 return(0);
10900 }
10901
10902 static int32_t inline
bbr_state_startup(struct tcp_bbr * bbr,uint32_t cts,int32_t epoch,int32_t pkt_epoch)10903 bbr_state_startup(struct tcp_bbr *bbr, uint32_t cts, int32_t epoch, int32_t pkt_epoch)
10904 {
10905 /* Have we gained 25% in the last 3 packet based epoch's? */
10906 uint64_t btlbw, gain;
10907 int do_exit;
10908 int delta, rtt_gain;
10909
10910 if ((bbr->rc_tp->snd_una == bbr->rc_tp->snd_max) &&
10911 (bbr_calc_time(cts, bbr->r_ctl.rc_went_idle_time) >= bbr_rtt_probe_time)) {
10912 /*
10913 * This qualifies as a RTT_PROBE session since we drop the
10914 * data outstanding to nothing and waited more than
10915 * bbr_rtt_probe_time.
10916 */
10917 bbr_log_rtt_shrinks(bbr, cts, 0, 0, __LINE__, BBR_RTTS_WASIDLE, 0);
10918 bbr_set_reduced_rtt(bbr, cts, __LINE__);
10919 }
10920 if (bbr_should_enter_probe_rtt(bbr, cts)) {
10921 bbr_enter_probe_rtt(bbr, cts, __LINE__);
10922 return (0);
10923 }
10924 if (bbr->rc_use_google)
10925 return (bbr_google_startup(bbr, cts, pkt_epoch));
10926
10927 if ((bbr->r_ctl.rc_lost > bbr->r_ctl.rc_lost_at_startup) &&
10928 (bbr_use_lower_gain_in_startup)) {
10929 /* Drop to a lower gain 1.5 x since we saw loss */
10930 bbr->r_ctl.rc_bbr_hptsi_gain = bbr_startup_lower;
10931 }
10932 if (pkt_epoch == 0) {
10933 /*
10934 * Need to be on a pkt-epoch to continue.
10935 */
10936 return (0);
10937 }
10938 if (bbr_rtt_gain_thresh) {
10939 /*
10940 * Do we allow a flow to stay
10941 * in startup with no loss and no
10942 * gain in rtt over a set threshold?
10943 */
10944 if (bbr->r_ctl.rc_pkt_epoch_rtt &&
10945 bbr->r_ctl.startup_last_srtt &&
10946 (bbr->r_ctl.rc_pkt_epoch_rtt > bbr->r_ctl.startup_last_srtt)) {
10947 delta = bbr->r_ctl.rc_pkt_epoch_rtt - bbr->r_ctl.startup_last_srtt;
10948 rtt_gain = (delta * 100) / bbr->r_ctl.startup_last_srtt;
10949 } else
10950 rtt_gain = 0;
10951 if ((bbr->r_ctl.startup_last_srtt == 0) ||
10952 (bbr->r_ctl.rc_pkt_epoch_rtt < bbr->r_ctl.startup_last_srtt))
10953 /* First time or new lower value */
10954 bbr->r_ctl.startup_last_srtt = bbr->r_ctl.rc_pkt_epoch_rtt;
10955
10956 if ((bbr->r_ctl.rc_lost == 0) &&
10957 (rtt_gain < bbr_rtt_gain_thresh)) {
10958 /*
10959 * No loss, and we are under
10960 * our gain threhold for
10961 * increasing RTT.
10962 */
10963 if (bbr->r_ctl.rc_bbr_last_startup_epoch < bbr->r_ctl.rc_pkt_epoch)
10964 bbr->r_ctl.rc_bbr_last_startup_epoch++;
10965 bbr_log_startup_event(bbr, cts, rtt_gain,
10966 delta, bbr->r_ctl.startup_last_srtt, 10);
10967 return (0);
10968 }
10969 }
10970 if ((bbr->r_ctl.r_measurement_count == bbr->r_ctl.last_startup_measure) &&
10971 (bbr->r_ctl.rc_lost_at_startup == bbr->r_ctl.rc_lost) &&
10972 (!IN_RECOVERY(bbr->rc_tp->t_flags))) {
10973 /*
10974 * We only assess if we have a new measurement when
10975 * we have no loss and are not in recovery.
10976 * Drag up by one our last_startup epoch so we will hold
10977 * the number of non-gain we have already accumulated.
10978 */
10979 if (bbr->r_ctl.rc_bbr_last_startup_epoch < bbr->r_ctl.rc_pkt_epoch)
10980 bbr->r_ctl.rc_bbr_last_startup_epoch++;
10981 bbr_log_startup_event(bbr, cts, bbr->r_ctl.rc_bbr_last_startup_epoch,
10982 bbr->r_ctl.rc_lost_at_startup, bbr_start_exit, 9);
10983 return (0);
10984 }
10985 /* Case where we reduced the lost (bad retransmit) */
10986 if (bbr->r_ctl.rc_lost_at_startup > bbr->r_ctl.rc_lost)
10987 bbr->r_ctl.rc_lost_at_startup = bbr->r_ctl.rc_lost;
10988 bbr->r_ctl.last_startup_measure = bbr->r_ctl.r_measurement_count;
10989 btlbw = bbr_get_full_bw(bbr);
10990 if (bbr->r_ctl.rc_bbr_hptsi_gain == bbr_startup_lower)
10991 gain = ((bbr->r_ctl.rc_bbr_lastbtlbw *
10992 (uint64_t)bbr_low_start_exit) / (uint64_t)100) + bbr->r_ctl.rc_bbr_lastbtlbw;
10993 else
10994 gain = ((bbr->r_ctl.rc_bbr_lastbtlbw *
10995 (uint64_t)bbr_start_exit) / (uint64_t)100) + bbr->r_ctl.rc_bbr_lastbtlbw;
10996 do_exit = 0;
10997 if (btlbw > bbr->r_ctl.rc_bbr_lastbtlbw)
10998 bbr->r_ctl.rc_bbr_lastbtlbw = btlbw;
10999 if (btlbw >= gain) {
11000 bbr->r_ctl.rc_bbr_last_startup_epoch = bbr->r_ctl.rc_pkt_epoch;
11001 /* Update the lost so we won't exit in next set of tests */
11002 bbr->r_ctl.rc_lost_at_startup = bbr->r_ctl.rc_lost;
11003 bbr_log_startup_event(bbr, cts, bbr->r_ctl.rc_bbr_last_startup_epoch,
11004 bbr->r_ctl.rc_lost_at_startup, bbr_start_exit, 3);
11005 }
11006 if ((bbr->rc_loss_exit &&
11007 (bbr->r_ctl.rc_lost > bbr->r_ctl.rc_lost_at_startup) &&
11008 (bbr->r_ctl.rc_pkt_epoch_loss_rate > bbr_startup_loss_thresh)) &&
11009 ((bbr->r_ctl.rc_pkt_epoch - bbr->r_ctl.rc_bbr_last_startup_epoch) >= BBR_STARTUP_EPOCHS)) {
11010 /*
11011 * If we had no gain, we had loss and that loss was above
11012 * our threshould, the rwnd is not constrained, and we have
11013 * had at least 3 packet epochs exit. Note that this is
11014 * switched off by sysctl. Google does not do this by the
11015 * way.
11016 */
11017 if ((ctf_flight_size(bbr->rc_tp,
11018 (bbr->r_ctl.rc_sacked + bbr->r_ctl.rc_lost_bytes)) +
11019 (2 * max(bbr->r_ctl.rc_pace_max_segs, bbr->rc_tp->t_maxseg))) <= bbr->rc_tp->snd_wnd) {
11020 do_exit = 1;
11021 bbr_log_startup_event(bbr, cts, bbr->r_ctl.rc_bbr_last_startup_epoch,
11022 bbr->r_ctl.rc_lost_at_startup, bbr_start_exit, 4);
11023 } else {
11024 /* Just record an updated loss value */
11025 bbr->r_ctl.rc_lost_at_startup = bbr->r_ctl.rc_lost;
11026 bbr_log_startup_event(bbr, cts, bbr->r_ctl.rc_bbr_last_startup_epoch,
11027 bbr->r_ctl.rc_lost_at_startup, bbr_start_exit, 5);
11028 }
11029 } else
11030 bbr->r_ctl.rc_lost_at_startup = bbr->r_ctl.rc_lost;
11031 if (((bbr->r_ctl.rc_pkt_epoch - bbr->r_ctl.rc_bbr_last_startup_epoch) >= BBR_STARTUP_EPOCHS) ||
11032 do_exit) {
11033 /* Return 1 to exit the startup state. */
11034 return (1);
11035 }
11036 /* Stay in startup */
11037 bbr_log_startup_event(bbr, cts, bbr->r_ctl.rc_bbr_last_startup_epoch,
11038 bbr->r_ctl.rc_lost_at_startup, bbr_start_exit, 8);
11039 return (0);
11040 }
11041
11042 static void
bbr_state_change(struct tcp_bbr * bbr,uint32_t cts,int32_t epoch,int32_t pkt_epoch,uint32_t losses)11043 bbr_state_change(struct tcp_bbr *bbr, uint32_t cts, int32_t epoch, int32_t pkt_epoch, uint32_t losses)
11044 {
11045 /*
11046 * A tick occurred in the rtt epoch do we need to do anything?
11047 */
11048 #ifdef BBR_INVARIANTS
11049 if ((bbr->rc_bbr_state != BBR_STATE_STARTUP) &&
11050 (bbr->rc_bbr_state != BBR_STATE_DRAIN) &&
11051 (bbr->rc_bbr_state != BBR_STATE_PROBE_RTT) &&
11052 (bbr->rc_bbr_state != BBR_STATE_IDLE_EXIT) &&
11053 (bbr->rc_bbr_state != BBR_STATE_PROBE_BW)) {
11054 /* Debug code? */
11055 panic("Unknown BBR state %d?\n", bbr->rc_bbr_state);
11056 }
11057 #endif
11058 if (bbr->rc_bbr_state == BBR_STATE_STARTUP) {
11059 /* Do we exit the startup state? */
11060 if (bbr_state_startup(bbr, cts, epoch, pkt_epoch)) {
11061 uint32_t time_in;
11062
11063 bbr_log_startup_event(bbr, cts, bbr->r_ctl.rc_bbr_last_startup_epoch,
11064 bbr->r_ctl.rc_lost_at_startup, bbr_start_exit, 6);
11065 bbr->rc_filled_pipe = 1;
11066 bbr->r_ctl.bbr_lost_at_state = bbr->r_ctl.rc_lost;
11067 if (SEQ_GT(cts, bbr->r_ctl.rc_bbr_state_time)) {
11068 time_in = cts - bbr->r_ctl.rc_bbr_state_time;
11069 counter_u64_add(bbr_state_time[bbr->rc_bbr_state], time_in);
11070 } else
11071 time_in = 0;
11072 if (bbr->rc_no_pacing)
11073 bbr->rc_no_pacing = 0;
11074 bbr->r_ctl.rc_bbr_state_time = cts;
11075 bbr->r_ctl.rc_bbr_hptsi_gain = bbr->r_ctl.rc_drain_pg;
11076 bbr->rc_bbr_state = BBR_STATE_DRAIN;
11077 bbr_set_state_target(bbr, __LINE__);
11078 if ((bbr->rc_use_google == 0) &&
11079 bbr_slam_cwnd_in_main_drain) {
11080 /* Here we don't have to worry about probe-rtt */
11081 bbr->r_ctl.rc_saved_cwnd = bbr->rc_tp->snd_cwnd;
11082 bbr->rc_tp->snd_cwnd = bbr->r_ctl.rc_target_at_state;
11083 bbr_log_type_cwndupd(bbr, 0, 0, 0, 12, 0, 0, __LINE__);
11084 }
11085 bbr->r_ctl.rc_bbr_cwnd_gain = bbr_high_gain;
11086 bbr_log_type_statechange(bbr, cts, __LINE__);
11087 if (ctf_flight_size(bbr->rc_tp,
11088 (bbr->r_ctl.rc_sacked + bbr->r_ctl.rc_lost_bytes)) <=
11089 bbr->r_ctl.rc_target_at_state) {
11090 /*
11091 * Switch to probe_bw if we are already
11092 * there
11093 */
11094 bbr->rc_bbr_substate = bbr_pick_probebw_substate(bbr, cts);
11095 bbr_substate_change(bbr, cts, __LINE__, 0);
11096 bbr->rc_bbr_state = BBR_STATE_PROBE_BW;
11097 bbr_log_type_statechange(bbr, cts, __LINE__);
11098 }
11099 }
11100 } else if (bbr->rc_bbr_state == BBR_STATE_IDLE_EXIT) {
11101 uint32_t inflight;
11102 struct tcpcb *tp;
11103
11104 tp = bbr->rc_tp;
11105 inflight = ctf_flight_size(tp,
11106 (bbr->r_ctl.rc_sacked + bbr->r_ctl.rc_lost_bytes));
11107 if (inflight >= bbr->r_ctl.rc_target_at_state) {
11108 /* We have reached a flight of the cwnd target */
11109 bbr->rc_bbr_state = BBR_STATE_PROBE_BW;
11110 bbr->r_ctl.rc_bbr_hptsi_gain = BBR_UNIT;
11111 bbr->r_ctl.rc_bbr_cwnd_gain = BBR_UNIT;
11112 bbr_set_state_target(bbr, __LINE__);
11113 /*
11114 * Rig it so we don't do anything crazy and
11115 * start fresh with a new randomization.
11116 */
11117 bbr->r_ctl.bbr_smallest_srtt_this_state = 0xffffffff;
11118 bbr->rc_bbr_substate = BBR_SUB_LEVEL6;
11119 bbr_substate_change(bbr, cts, __LINE__, 1);
11120 }
11121 } else if (bbr->rc_bbr_state == BBR_STATE_DRAIN) {
11122 /* Has in-flight reached the bdp (or less)? */
11123 uint32_t inflight;
11124 struct tcpcb *tp;
11125
11126 tp = bbr->rc_tp;
11127 inflight = ctf_flight_size(tp,
11128 (bbr->r_ctl.rc_sacked + bbr->r_ctl.rc_lost_bytes));
11129 if ((bbr->rc_use_google == 0) &&
11130 bbr_slam_cwnd_in_main_drain &&
11131 (bbr->rc_tp->snd_cwnd > bbr->r_ctl.rc_target_at_state)) {
11132 /*
11133 * Here we don't have to worry about probe-rtt
11134 * re-slam it, but keep it slammed down.
11135 */
11136 bbr->rc_tp->snd_cwnd = bbr->r_ctl.rc_target_at_state;
11137 bbr_log_type_cwndupd(bbr, 0, 0, 0, 12, 0, 0, __LINE__);
11138 }
11139 if (inflight <= bbr->r_ctl.rc_target_at_state) {
11140 /* We have drained */
11141 bbr->rc_bbr_state = BBR_STATE_PROBE_BW;
11142 bbr->r_ctl.bbr_lost_at_state = bbr->r_ctl.rc_lost;
11143 if (SEQ_GT(cts, bbr->r_ctl.rc_bbr_state_time)) {
11144 uint32_t time_in;
11145
11146 time_in = cts - bbr->r_ctl.rc_bbr_state_time;
11147 counter_u64_add(bbr_state_time[bbr->rc_bbr_state], time_in);
11148 }
11149 if ((bbr->rc_use_google == 0) &&
11150 bbr_slam_cwnd_in_main_drain &&
11151 (tp->snd_cwnd < bbr->r_ctl.rc_saved_cwnd)) {
11152 /* Restore the cwnd */
11153 tp->snd_cwnd = bbr->r_ctl.rc_saved_cwnd;
11154 bbr_log_type_cwndupd(bbr, 0, 0, 0, 12, 0, 0, __LINE__);
11155 }
11156 /* Setup probe-rtt has being done now RRS-HERE */
11157 bbr->r_ctl.rc_rtt_shrinks = cts;
11158 bbr->r_ctl.last_in_probertt = cts;
11159 bbr_log_rtt_shrinks(bbr, cts, 0, 0, __LINE__, BBR_RTTS_LEAVE_DRAIN, 0);
11160 /* Randomly pick a sub-state */
11161 bbr->rc_bbr_substate = bbr_pick_probebw_substate(bbr, cts);
11162 bbr_substate_change(bbr, cts, __LINE__, 0);
11163 bbr_log_type_statechange(bbr, cts, __LINE__);
11164 }
11165 } else if (bbr->rc_bbr_state == BBR_STATE_PROBE_RTT) {
11166 uint32_t flight;
11167
11168 flight = ctf_flight_size(bbr->rc_tp,
11169 (bbr->r_ctl.rc_sacked + bbr->r_ctl.rc_lost_bytes));
11170 bbr->r_ctl.r_app_limited_until = (flight + bbr->r_ctl.rc_delivered);
11171 if (((bbr->r_ctl.bbr_rttprobe_gain_val == 0) || bbr->rc_use_google) &&
11172 (bbr->rc_tp->snd_cwnd > bbr->r_ctl.rc_target_at_state)) {
11173 /*
11174 * We must keep cwnd at the desired MSS.
11175 */
11176 bbr->rc_tp->snd_cwnd = bbr_rtt_probe_cwndtarg * (bbr->rc_tp->t_maxseg - bbr->rc_last_options);
11177 bbr_log_type_cwndupd(bbr, 0, 0, 0, 12, 0, 0, __LINE__);
11178 } else if ((bbr_prtt_slam_cwnd) &&
11179 (bbr->rc_tp->snd_cwnd > bbr->r_ctl.rc_target_at_state)) {
11180 /* Re-slam it */
11181 bbr->rc_tp->snd_cwnd = bbr->r_ctl.rc_target_at_state;
11182 bbr_log_type_cwndupd(bbr, 0, 0, 0, 12, 0, 0, __LINE__);
11183 }
11184 if (bbr->r_ctl.rc_bbr_enters_probertt == 0) {
11185 /* Has outstanding reached our target? */
11186 if (flight <= bbr->r_ctl.rc_target_at_state) {
11187 bbr_log_rtt_shrinks(bbr, cts, 0, 0, __LINE__, BBR_RTTS_REACHTAR, 0);
11188 bbr->r_ctl.rc_bbr_enters_probertt = cts;
11189 /* If time is exactly 0, be 1usec off */
11190 if (bbr->r_ctl.rc_bbr_enters_probertt == 0)
11191 bbr->r_ctl.rc_bbr_enters_probertt = 1;
11192 if (bbr->rc_use_google == 0) {
11193 /*
11194 * Restore any lowering that as occurred to
11195 * reach here
11196 */
11197 if (bbr->r_ctl.bbr_rttprobe_gain_val)
11198 bbr->r_ctl.rc_bbr_hptsi_gain = bbr->r_ctl.bbr_rttprobe_gain_val;
11199 else
11200 bbr->r_ctl.rc_bbr_hptsi_gain = BBR_UNIT;
11201 }
11202 }
11203 if ((bbr->r_ctl.rc_bbr_enters_probertt == 0) &&
11204 (bbr->rc_use_google == 0) &&
11205 bbr->r_ctl.bbr_rttprobe_gain_val &&
11206 (((cts - bbr->r_ctl.rc_probertt_srttchktim) > bbr_get_rtt(bbr, bbr_drain_rtt)) ||
11207 (flight >= bbr->r_ctl.flightsize_at_drain))) {
11208 /*
11209 * We have doddled with our current hptsi
11210 * gain an srtt and have still not made it
11211 * to target, or we have increased our flight.
11212 * Lets reduce the gain by xx%
11213 * flooring the reduce at DRAIN (based on
11214 * mul/div)
11215 */
11216 int red;
11217
11218 bbr->r_ctl.flightsize_at_drain = flight;
11219 bbr->r_ctl.rc_probertt_srttchktim = cts;
11220 red = max((bbr->r_ctl.bbr_rttprobe_gain_val / 10), 1);
11221 if ((bbr->r_ctl.rc_bbr_hptsi_gain - red) > max(bbr_drain_floor, 1)) {
11222 /* Reduce our gain again */
11223 bbr->r_ctl.rc_bbr_hptsi_gain -= red;
11224 bbr_log_rtt_shrinks(bbr, cts, 0, 0, __LINE__, BBR_RTTS_SHRINK_PG, 0);
11225 } else if (bbr->r_ctl.rc_bbr_hptsi_gain > max(bbr_drain_floor, 1)) {
11226 /* one more chance before we give up */
11227 bbr->r_ctl.rc_bbr_hptsi_gain = max(bbr_drain_floor, 1);
11228 bbr_log_rtt_shrinks(bbr, cts, 0, 0, __LINE__, BBR_RTTS_SHRINK_PG_FINAL, 0);
11229 } else {
11230 /* At the very bottom */
11231 bbr->r_ctl.rc_bbr_hptsi_gain = max((bbr_drain_floor-1), 1);
11232 }
11233 }
11234 }
11235 if (bbr->r_ctl.rc_bbr_enters_probertt &&
11236 (TSTMP_GT(cts, bbr->r_ctl.rc_bbr_enters_probertt)) &&
11237 ((cts - bbr->r_ctl.rc_bbr_enters_probertt) >= bbr_rtt_probe_time)) {
11238 /* Time to exit probe RTT normally */
11239 bbr_exit_probe_rtt(bbr->rc_tp, bbr, cts);
11240 }
11241 } else if (bbr->rc_bbr_state == BBR_STATE_PROBE_BW) {
11242 if ((bbr->rc_tp->snd_una == bbr->rc_tp->snd_max) &&
11243 (bbr_calc_time(cts, bbr->r_ctl.rc_went_idle_time) >= bbr_rtt_probe_time)) {
11244 /*
11245 * This qualifies as a RTT_PROBE session since we
11246 * drop the data outstanding to nothing and waited
11247 * more than bbr_rtt_probe_time.
11248 */
11249 bbr_log_rtt_shrinks(bbr, cts, 0, 0, __LINE__, BBR_RTTS_WASIDLE, 0);
11250 bbr_set_reduced_rtt(bbr, cts, __LINE__);
11251 }
11252 if (bbr_should_enter_probe_rtt(bbr, cts)) {
11253 bbr_enter_probe_rtt(bbr, cts, __LINE__);
11254 } else {
11255 bbr_set_probebw_gains(bbr, cts, losses);
11256 }
11257 }
11258 }
11259
11260 static void
bbr_check_bbr_for_state(struct tcp_bbr * bbr,uint32_t cts,int32_t line,uint32_t losses)11261 bbr_check_bbr_for_state(struct tcp_bbr *bbr, uint32_t cts, int32_t line, uint32_t losses)
11262 {
11263 int32_t epoch = 0;
11264
11265 if ((cts - bbr->r_ctl.rc_rcv_epoch_start) >= bbr_get_rtt(bbr, BBR_RTT_PROP)) {
11266 bbr_set_epoch(bbr, cts, line);
11267 /* At each epoch doe lt bw sampling */
11268 epoch = 1;
11269 }
11270 bbr_state_change(bbr, cts, epoch, bbr->rc_is_pkt_epoch_now, losses);
11271 }
11272
11273 static int
bbr_do_segment_nounlock(struct tcpcb * tp,struct mbuf * m,struct tcphdr * th,int32_t drop_hdrlen,int32_t tlen,uint8_t iptos,int32_t nxt_pkt,struct timeval * tv)11274 bbr_do_segment_nounlock(struct tcpcb *tp, struct mbuf *m, struct tcphdr *th,
11275 int32_t drop_hdrlen, int32_t tlen, uint8_t iptos, int32_t nxt_pkt,
11276 struct timeval *tv)
11277 {
11278 struct inpcb *inp = tptoinpcb(tp);
11279 struct socket *so = tptosocket(tp);
11280 int32_t thflags, retval;
11281 uint32_t cts, lcts;
11282 uint32_t tiwin;
11283 struct tcpopt to;
11284 struct tcp_bbr *bbr;
11285 struct bbr_sendmap *rsm;
11286 struct timeval ltv;
11287 int32_t did_out = 0;
11288 uint16_t nsegs;
11289 int32_t prev_state;
11290 uint32_t lost;
11291
11292 nsegs = max(1, m->m_pkthdr.lro_nsegs);
11293 bbr = (struct tcp_bbr *)tp->t_fb_ptr;
11294 /* add in our stats */
11295 kern_prefetch(bbr, &prev_state);
11296 prev_state = 0;
11297 thflags = tcp_get_flags(th);
11298 /*
11299 * If this is either a state-changing packet or current state isn't
11300 * established, we require a write lock on tcbinfo. Otherwise, we
11301 * allow the tcbinfo to be in either alocked or unlocked, as the
11302 * caller may have unnecessarily acquired a write lock due to a
11303 * race.
11304 */
11305 INP_WLOCK_ASSERT(tptoinpcb(tp));
11306 KASSERT(tp->t_state > TCPS_LISTEN, ("%s: TCPS_LISTEN",
11307 __func__));
11308 KASSERT(tp->t_state != TCPS_TIME_WAIT, ("%s: TCPS_TIME_WAIT",
11309 __func__));
11310
11311 tp->t_rcvtime = ticks;
11312 /*
11313 * Unscale the window into a 32-bit value. For the SYN_SENT state
11314 * the scale is zero.
11315 */
11316 tiwin = th->th_win << tp->snd_scale;
11317 #ifdef STATS
11318 stats_voi_update_abs_ulong(tp->t_stats, VOI_TCP_FRWIN, tiwin);
11319 #endif
11320
11321 if (m->m_flags & M_TSTMP) {
11322 /* Prefer the hardware timestamp if present */
11323 struct timespec ts;
11324
11325 mbuf_tstmp2timespec(m, &ts);
11326 bbr->rc_tv.tv_sec = ts.tv_sec;
11327 bbr->rc_tv.tv_usec = ts.tv_nsec / 1000;
11328 bbr->r_ctl.rc_rcvtime = cts = tcp_tv_to_usec(&bbr->rc_tv);
11329 } else if (m->m_flags & M_TSTMP_LRO) {
11330 /* Next the arrival timestamp */
11331 struct timespec ts;
11332
11333 mbuf_tstmp2timespec(m, &ts);
11334 bbr->rc_tv.tv_sec = ts.tv_sec;
11335 bbr->rc_tv.tv_usec = ts.tv_nsec / 1000;
11336 bbr->r_ctl.rc_rcvtime = cts = tcp_tv_to_usec(&bbr->rc_tv);
11337 } else {
11338 /*
11339 * Ok just get the current time.
11340 */
11341 bbr->r_ctl.rc_rcvtime = lcts = cts = tcp_get_usecs(&bbr->rc_tv);
11342 }
11343 /*
11344 * Parse options on any incoming segment.
11345 */
11346 tcp_dooptions(&to, (u_char *)(th + 1),
11347 (th->th_off << 2) - sizeof(struct tcphdr),
11348 (thflags & TH_SYN) ? TO_SYN : 0);
11349 if (tp->t_flags2 & TF2_PROC_SACK_PROHIBIT) {
11350 /*
11351 * We don't look at sack's from the
11352 * peer because the MSS is too small which
11353 * can subject us to an attack.
11354 */
11355 to.to_flags &= ~TOF_SACK;
11356 }
11357 /*
11358 * If timestamps were negotiated during SYN/ACK and a
11359 * segment without a timestamp is received, silently drop
11360 * the segment, unless it is a RST segment or missing timestamps are
11361 * tolerated.
11362 * See section 3.2 of RFC 7323.
11363 */
11364 if ((tp->t_flags & TF_RCVD_TSTMP) && !(to.to_flags & TOF_TS) &&
11365 ((thflags & TH_RST) == 0) && (V_tcp_tolerate_missing_ts == 0)) {
11366 retval = 0;
11367 m_freem(m);
11368 goto done_with_input;
11369 }
11370 /*
11371 * If echoed timestamp is later than the current time, fall back to
11372 * non RFC1323 RTT calculation. Normalize timestamp if syncookies
11373 * were used when this connection was established.
11374 */
11375 if ((to.to_flags & TOF_TS) && (to.to_tsecr != 0)) {
11376 to.to_tsecr -= tp->ts_offset;
11377 if (TSTMP_GT(to.to_tsecr, tcp_tv_to_msec(&bbr->rc_tv)))
11378 to.to_tsecr = 0;
11379 }
11380 /*
11381 * If its the first time in we need to take care of options and
11382 * verify we can do SACK for rack!
11383 */
11384 if (bbr->r_state == 0) {
11385 /*
11386 * Process options only when we get SYN/ACK back. The SYN
11387 * case for incoming connections is handled in tcp_syncache.
11388 * According to RFC1323 the window field in a SYN (i.e., a
11389 * <SYN> or <SYN,ACK>) segment itself is never scaled. XXX
11390 * this is traditional behavior, may need to be cleaned up.
11391 */
11392 if (bbr->rc_inp == NULL) {
11393 bbr->rc_inp = inp;
11394 }
11395 /*
11396 * We need to init rc_inp here since its not init'd when
11397 * bbr_init is called
11398 */
11399 if (tp->t_state == TCPS_SYN_SENT && (thflags & TH_SYN)) {
11400 if ((to.to_flags & TOF_SCALE) &&
11401 (tp->t_flags & TF_REQ_SCALE)) {
11402 tp->t_flags |= TF_RCVD_SCALE;
11403 tp->snd_scale = to.to_wscale;
11404 } else
11405 tp->t_flags &= ~TF_REQ_SCALE;
11406 /*
11407 * Initial send window. It will be updated with the
11408 * next incoming segment to the scaled value.
11409 */
11410 tp->snd_wnd = th->th_win;
11411 if ((to.to_flags & TOF_TS) &&
11412 (tp->t_flags & TF_REQ_TSTMP)) {
11413 tp->t_flags |= TF_RCVD_TSTMP;
11414 tp->ts_recent = to.to_tsval;
11415 tp->ts_recent_age = tcp_tv_to_msec(&bbr->rc_tv);
11416 } else
11417 tp->t_flags &= ~TF_REQ_TSTMP;
11418 if (to.to_flags & TOF_MSS)
11419 tcp_mss(tp, to.to_mss);
11420 if ((tp->t_flags & TF_SACK_PERMIT) &&
11421 (to.to_flags & TOF_SACKPERM) == 0)
11422 tp->t_flags &= ~TF_SACK_PERMIT;
11423 if (tp->t_flags & TF_FASTOPEN) {
11424 if (to.to_flags & TOF_FASTOPEN) {
11425 uint16_t mss;
11426
11427 if (to.to_flags & TOF_MSS)
11428 mss = to.to_mss;
11429 else
11430 if ((inp->inp_vflag & INP_IPV6) != 0)
11431 mss = TCP6_MSS;
11432 else
11433 mss = TCP_MSS;
11434 tcp_fastopen_update_cache(tp, mss,
11435 to.to_tfo_len, to.to_tfo_cookie);
11436 } else
11437 tcp_fastopen_disable_path(tp);
11438 }
11439 }
11440 /*
11441 * At this point we are at the initial call. Here we decide
11442 * if we are doing RACK or not. We do this by seeing if
11443 * TF_SACK_PERMIT is set, if not rack is *not* possible and
11444 * we switch to the default code.
11445 */
11446 if ((tp->t_flags & TF_SACK_PERMIT) == 0) {
11447 /* Bail */
11448 tcp_switch_back_to_default(tp);
11449 (*tp->t_fb->tfb_tcp_do_segment)(tp, m, th, drop_hdrlen,
11450 tlen, iptos);
11451 return (1);
11452 }
11453 /* Set the flag */
11454 bbr->r_is_v6 = (inp->inp_vflag & INP_IPV6) != 0;
11455 tcp_set_hpts(tp);
11456 sack_filter_clear(&bbr->r_ctl.bbr_sf, th->th_ack);
11457 }
11458 if (thflags & TH_ACK) {
11459 /* Track ack types */
11460 if (to.to_flags & TOF_SACK)
11461 BBR_STAT_INC(bbr_acks_with_sacks);
11462 else
11463 BBR_STAT_INC(bbr_plain_acks);
11464 }
11465 /*
11466 * This is the one exception case where we set the rack state
11467 * always. All other times (timers etc) we must have a rack-state
11468 * set (so we assure we have done the checks above for SACK).
11469 */
11470 if (thflags & TH_FIN)
11471 tcp_log_end_status(tp, TCP_EI_STATUS_CLIENT_FIN);
11472 if (bbr->r_state != tp->t_state)
11473 bbr_set_state(tp, bbr, tiwin);
11474
11475 if (SEQ_GT(th->th_ack, tp->snd_una) && (rsm = TAILQ_FIRST(&bbr->r_ctl.rc_map)) != NULL)
11476 kern_prefetch(rsm, &prev_state);
11477 prev_state = bbr->r_state;
11478 bbr->rc_ack_was_delayed = 0;
11479 lost = bbr->r_ctl.rc_lost;
11480 bbr->rc_is_pkt_epoch_now = 0;
11481 if (m->m_flags & (M_TSTMP|M_TSTMP_LRO)) {
11482 /* Get the real time into lcts and figure the real delay */
11483 lcts = tcp_get_usecs(<v);
11484 if (TSTMP_GT(lcts, cts)) {
11485 bbr->r_ctl.rc_ack_hdwr_delay = lcts - cts;
11486 bbr->rc_ack_was_delayed = 1;
11487 if (TSTMP_GT(bbr->r_ctl.rc_ack_hdwr_delay,
11488 bbr->r_ctl.highest_hdwr_delay))
11489 bbr->r_ctl.highest_hdwr_delay = bbr->r_ctl.rc_ack_hdwr_delay;
11490 } else {
11491 bbr->r_ctl.rc_ack_hdwr_delay = 0;
11492 bbr->rc_ack_was_delayed = 0;
11493 }
11494 } else {
11495 bbr->r_ctl.rc_ack_hdwr_delay = 0;
11496 bbr->rc_ack_was_delayed = 0;
11497 }
11498 bbr_log_ack_event(bbr, th, &to, tlen, nsegs, cts, nxt_pkt, m);
11499 if ((thflags & TH_SYN) && (thflags & TH_FIN) && V_drop_synfin) {
11500 retval = 0;
11501 m_freem(m);
11502 goto done_with_input;
11503 }
11504 /*
11505 * If a segment with the ACK-bit set arrives in the SYN-SENT state
11506 * check SEQ.ACK first as described on page 66 of RFC 793, section 3.9.
11507 */
11508 if ((tp->t_state == TCPS_SYN_SENT) && (thflags & TH_ACK) &&
11509 (SEQ_LEQ(th->th_ack, tp->iss) || SEQ_GT(th->th_ack, tp->snd_max))) {
11510 tcp_log_end_status(tp, TCP_EI_STATUS_RST_IN_FRONT);
11511 ctf_do_dropwithreset_conn(m, tp, th, tlen);
11512 return (1);
11513 }
11514 if (tiwin > bbr->r_ctl.rc_high_rwnd)
11515 bbr->r_ctl.rc_high_rwnd = tiwin;
11516 bbr->r_ctl.rc_flight_at_input = ctf_flight_size(tp,
11517 (bbr->r_ctl.rc_sacked + bbr->r_ctl.rc_lost_bytes));
11518 bbr->rtt_valid = 0;
11519 if (to.to_flags & TOF_TS) {
11520 bbr->rc_ts_valid = 1;
11521 bbr->r_ctl.last_inbound_ts = to.to_tsval;
11522 } else {
11523 bbr->rc_ts_valid = 0;
11524 bbr->r_ctl.last_inbound_ts = 0;
11525 }
11526 retval = (*bbr->r_substate) (m, th, so,
11527 tp, &to, drop_hdrlen,
11528 tlen, tiwin, thflags, nxt_pkt, iptos);
11529 if (nxt_pkt == 0)
11530 BBR_STAT_INC(bbr_rlock_left_ret0);
11531 else
11532 BBR_STAT_INC(bbr_rlock_left_ret1);
11533 if (retval == 0) {
11534 /*
11535 * If retval is 1 the tcb is unlocked and most likely the tp
11536 * is gone.
11537 */
11538 INP_WLOCK_ASSERT(inp);
11539 tcp_bbr_xmit_timer_commit(bbr, tp, cts);
11540 if (bbr->rc_is_pkt_epoch_now)
11541 bbr_set_pktepoch(bbr, cts, __LINE__);
11542 bbr_check_bbr_for_state(bbr, cts, __LINE__, (bbr->r_ctl.rc_lost - lost));
11543 if (nxt_pkt == 0) {
11544 if ((bbr->r_wanted_output != 0) ||
11545 (tp->t_flags & TF_ACKNOW)) {
11546
11547 bbr->rc_output_starts_timer = 0;
11548 did_out = 1;
11549 if (tcp_output(tp) < 0)
11550 return (1);
11551 } else
11552 bbr_start_hpts_timer(bbr, tp, cts, 6, 0, 0);
11553 }
11554 if ((nxt_pkt == 0) &&
11555 ((bbr->r_ctl.rc_hpts_flags & PACE_TMR_MASK) == 0) &&
11556 (SEQ_GT(tp->snd_max, tp->snd_una) ||
11557 (tp->t_flags & TF_DELACK) ||
11558 ((V_tcp_always_keepalive || bbr->rc_inp->inp_socket->so_options & SO_KEEPALIVE) &&
11559 (tp->t_state <= TCPS_CLOSING)))) {
11560 /*
11561 * We could not send (probably in the hpts but
11562 * stopped the timer)?
11563 */
11564 if ((tp->snd_max == tp->snd_una) &&
11565 ((tp->t_flags & TF_DELACK) == 0) &&
11566 (tcp_in_hpts(tp)) &&
11567 (bbr->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT)) {
11568 /*
11569 * keep alive not needed if we are hptsi
11570 * output yet
11571 */
11572 ;
11573 } else {
11574 if (tcp_in_hpts(tp)) {
11575 tcp_hpts_remove(tp);
11576 if ((bbr->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT) &&
11577 (TSTMP_GT(lcts, bbr->rc_pacer_started))) {
11578 uint32_t del;
11579
11580 del = lcts - bbr->rc_pacer_started;
11581 if (bbr->r_ctl.rc_last_delay_val > del) {
11582 BBR_STAT_INC(bbr_force_timer_start);
11583 bbr->r_ctl.rc_last_delay_val -= del;
11584 bbr->rc_pacer_started = lcts;
11585 } else {
11586 /* We are late */
11587 bbr->r_ctl.rc_last_delay_val = 0;
11588 BBR_STAT_INC(bbr_force_output);
11589 if (tcp_output(tp) < 0)
11590 return (1);
11591 }
11592 }
11593 }
11594 bbr_start_hpts_timer(bbr, tp, cts, 8, bbr->r_ctl.rc_last_delay_val,
11595 0);
11596 }
11597 } else if ((bbr->rc_output_starts_timer == 0) && (nxt_pkt == 0)) {
11598 /* Do we have the correct timer running? */
11599 bbr_timer_audit(tp, bbr, lcts, &so->so_snd);
11600 }
11601 /* Clear the flag, it may have been cleared by output but we may not have */
11602 if ((nxt_pkt == 0) && (tp->t_flags2 & TF2_HPTS_CALLS))
11603 tp->t_flags2 &= ~TF2_HPTS_CALLS;
11604 /* Do we have a new state */
11605 if (bbr->r_state != tp->t_state)
11606 bbr_set_state(tp, bbr, tiwin);
11607 done_with_input:
11608 bbr_log_doseg_done(bbr, cts, nxt_pkt, did_out);
11609 if (did_out)
11610 bbr->r_wanted_output = 0;
11611 }
11612 return (retval);
11613 }
11614
11615 static void
bbr_do_segment(struct tcpcb * tp,struct mbuf * m,struct tcphdr * th,int32_t drop_hdrlen,int32_t tlen,uint8_t iptos)11616 bbr_do_segment(struct tcpcb *tp, struct mbuf *m, struct tcphdr *th,
11617 int32_t drop_hdrlen, int32_t tlen, uint8_t iptos)
11618 {
11619 struct timeval tv;
11620 int retval;
11621
11622 /* First lets see if we have old packets */
11623 if (!STAILQ_EMPTY(&tp->t_inqueue)) {
11624 if (ctf_do_queued_segments(tp, 1)) {
11625 m_freem(m);
11626 return;
11627 }
11628 }
11629 if (m->m_flags & M_TSTMP_LRO) {
11630 mbuf_tstmp2timeval(m, &tv);
11631 } else {
11632 /* Should not be should we kassert instead? */
11633 tcp_get_usecs(&tv);
11634 }
11635 retval = bbr_do_segment_nounlock(tp, m, th, drop_hdrlen, tlen, iptos,
11636 0, &tv);
11637 if (retval == 0) {
11638 INP_WUNLOCK(tptoinpcb(tp));
11639 }
11640 }
11641
11642 /*
11643 * Return how much data can be sent without violating the
11644 * cwnd or rwnd.
11645 */
11646
11647 static inline uint32_t
bbr_what_can_we_send(struct tcpcb * tp,struct tcp_bbr * bbr,uint32_t sendwin,uint32_t avail,int32_t sb_offset,uint32_t cts)11648 bbr_what_can_we_send(struct tcpcb *tp, struct tcp_bbr *bbr, uint32_t sendwin,
11649 uint32_t avail, int32_t sb_offset, uint32_t cts)
11650 {
11651 uint32_t len;
11652
11653 if (ctf_outstanding(tp) >= tp->snd_wnd) {
11654 /* We never want to go over our peers rcv-window */
11655 len = 0;
11656 } else {
11657 uint32_t flight;
11658
11659 flight = ctf_flight_size(tp, (bbr->r_ctl.rc_sacked + bbr->r_ctl.rc_lost_bytes));
11660 if (flight >= sendwin) {
11661 /*
11662 * We have in flight what we are allowed by cwnd (if
11663 * it was rwnd blocking it would have hit above out
11664 * >= tp->snd_wnd).
11665 */
11666 return (0);
11667 }
11668 len = sendwin - flight;
11669 if ((len + ctf_outstanding(tp)) > tp->snd_wnd) {
11670 /* We would send too much (beyond the rwnd) */
11671 len = tp->snd_wnd - ctf_outstanding(tp);
11672 }
11673 if ((len + sb_offset) > avail) {
11674 /*
11675 * We don't have that much in the SB, how much is
11676 * there?
11677 */
11678 len = avail - sb_offset;
11679 }
11680 }
11681 return (len);
11682 }
11683
11684 static inline void
bbr_do_send_accounting(struct tcpcb * tp,struct tcp_bbr * bbr,struct bbr_sendmap * rsm,int32_t len,int32_t error)11685 bbr_do_send_accounting(struct tcpcb *tp, struct tcp_bbr *bbr, struct bbr_sendmap *rsm, int32_t len, int32_t error)
11686 {
11687 if (error) {
11688 return;
11689 }
11690 if (rsm) {
11691 if (rsm->r_flags & BBR_TLP) {
11692 /*
11693 * TLP should not count in retran count, but in its
11694 * own bin
11695 */
11696 KMOD_TCPSTAT_INC(tcps_tlpresends);
11697 KMOD_TCPSTAT_ADD(tcps_tlpresend_bytes, len);
11698 } else {
11699 /* Retransmit */
11700 tp->t_sndrexmitpack++;
11701 KMOD_TCPSTAT_INC(tcps_sndrexmitpack);
11702 KMOD_TCPSTAT_ADD(tcps_sndrexmitbyte, len);
11703 #ifdef STATS
11704 stats_voi_update_abs_u32(tp->t_stats, VOI_TCP_RETXPB,
11705 len);
11706 #endif
11707 }
11708 /*
11709 * Logs in 0 - 8, 8 is all non probe_bw states 0-7 is
11710 * sub-state
11711 */
11712 counter_u64_add(bbr_state_lost[rsm->r_bbr_state], len);
11713 if (bbr->rc_bbr_state != BBR_STATE_PROBE_BW) {
11714 /* Non probe_bw log in 1, 2, or 4. */
11715 counter_u64_add(bbr_state_resend[bbr->rc_bbr_state], len);
11716 } else {
11717 /*
11718 * Log our probe state 3, and log also 5-13 to show
11719 * us the recovery sub-state for the send. This
11720 * means that 3 == (5+6+7+8+9+10+11+12+13)
11721 */
11722 counter_u64_add(bbr_state_resend[BBR_STATE_PROBE_BW], len);
11723 counter_u64_add(bbr_state_resend[(bbr_state_val(bbr) + 5)], len);
11724 }
11725 /* Place in both 16's the totals of retransmitted */
11726 counter_u64_add(bbr_state_lost[16], len);
11727 counter_u64_add(bbr_state_resend[16], len);
11728 /* Place in 17's the total sent */
11729 counter_u64_add(bbr_state_resend[17], len);
11730 counter_u64_add(bbr_state_lost[17], len);
11731
11732 } else {
11733 /* New sends */
11734 KMOD_TCPSTAT_INC(tcps_sndpack);
11735 KMOD_TCPSTAT_ADD(tcps_sndbyte, len);
11736 /* Place in 17's the total sent */
11737 counter_u64_add(bbr_state_resend[17], len);
11738 counter_u64_add(bbr_state_lost[17], len);
11739 #ifdef STATS
11740 stats_voi_update_abs_u64(tp->t_stats, VOI_TCP_TXPB,
11741 len);
11742 #endif
11743 }
11744 }
11745
11746 static void
bbr_cwnd_limiting(struct tcpcb * tp,struct tcp_bbr * bbr,uint32_t in_level)11747 bbr_cwnd_limiting(struct tcpcb *tp, struct tcp_bbr *bbr, uint32_t in_level)
11748 {
11749 if (bbr->rc_filled_pipe && bbr_target_cwnd_mult_limit && (bbr->rc_use_google == 0)) {
11750 /*
11751 * Limit the cwnd to not be above N x the target plus whats
11752 * is outstanding. The target is based on the current b/w
11753 * estimate.
11754 */
11755 uint32_t target;
11756
11757 target = bbr_get_target_cwnd(bbr, bbr_get_bw(bbr), BBR_UNIT);
11758 target += ctf_outstanding(tp);
11759 target *= bbr_target_cwnd_mult_limit;
11760 if (tp->snd_cwnd > target)
11761 tp->snd_cwnd = target;
11762 bbr_log_type_cwndupd(bbr, 0, 0, 0, 10, 0, 0, __LINE__);
11763 }
11764 }
11765
11766 static int
bbr_window_update_needed(struct tcpcb * tp,struct socket * so,uint32_t recwin,int32_t maxseg)11767 bbr_window_update_needed(struct tcpcb *tp, struct socket *so, uint32_t recwin, int32_t maxseg)
11768 {
11769 /*
11770 * "adv" is the amount we could increase the window, taking into
11771 * account that we are limited by TCP_MAXWIN << tp->rcv_scale.
11772 */
11773 int32_t adv;
11774 int32_t oldwin;
11775
11776 adv = recwin;
11777 if (SEQ_GT(tp->rcv_adv, tp->rcv_nxt)) {
11778 oldwin = (tp->rcv_adv - tp->rcv_nxt);
11779 if (adv > oldwin)
11780 adv -= oldwin;
11781 else {
11782 /* We can't increase the window */
11783 adv = 0;
11784 }
11785 } else
11786 oldwin = 0;
11787
11788 /*
11789 * If the new window size ends up being the same as or less
11790 * than the old size when it is scaled, then don't force
11791 * a window update.
11792 */
11793 if (oldwin >> tp->rcv_scale >= (adv + oldwin) >> tp->rcv_scale)
11794 return (0);
11795
11796 if (adv >= (2 * maxseg) &&
11797 (adv >= (so->so_rcv.sb_hiwat / 4) ||
11798 recwin <= (so->so_rcv.sb_hiwat / 8) ||
11799 so->so_rcv.sb_hiwat <= 8 * maxseg)) {
11800 return (1);
11801 }
11802 if (2 * adv >= (int32_t) so->so_rcv.sb_hiwat)
11803 return (1);
11804 return (0);
11805 }
11806
11807 /*
11808 * Return 0 on success and a errno on failure to send.
11809 * Note that a 0 return may not mean we sent anything
11810 * if the TCB was on the hpts. A non-zero return
11811 * does indicate the error we got from ip[6]_output.
11812 */
11813 static int
bbr_output_wtime(struct tcpcb * tp,const struct timeval * tv)11814 bbr_output_wtime(struct tcpcb *tp, const struct timeval *tv)
11815 {
11816 struct socket *so;
11817 int32_t len;
11818 uint32_t cts;
11819 uint32_t recwin, sendwin;
11820 int32_t sb_offset;
11821 int32_t flags, abandon, error = 0;
11822 struct tcp_log_buffer *lgb;
11823 struct mbuf *m;
11824 struct mbuf *mb;
11825 uint32_t if_hw_tsomaxsegcount = 0;
11826 uint32_t if_hw_tsomaxsegsize = 0;
11827 uint32_t if_hw_tsomax = 0;
11828 struct ip *ip = NULL;
11829 struct tcp_bbr *bbr;
11830 struct tcphdr *th;
11831 struct udphdr *udp = NULL;
11832 u_char opt[TCP_MAXOLEN];
11833 unsigned ipoptlen, optlen, hdrlen;
11834 unsigned ulen;
11835 uint32_t bbr_seq;
11836 uint32_t delay_calc=0;
11837 uint8_t doing_tlp = 0;
11838 uint8_t local_options;
11839 #ifdef BBR_INVARIANTS
11840 uint8_t doing_retran_from = 0;
11841 uint8_t picked_up_retran = 0;
11842 #endif
11843 uint8_t wanted_cookie = 0;
11844 uint8_t more_to_rxt=0;
11845 int32_t prefetch_so_done = 0;
11846 int32_t prefetch_rsm = 0;
11847 uint32_t tot_len = 0;
11848 uint32_t maxseg, pace_max_segs, p_maxseg;
11849 int32_t csum_flags = 0;
11850 int32_t hw_tls;
11851 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
11852 unsigned ipsec_optlen = 0;
11853
11854 #endif
11855 volatile int32_t sack_rxmit;
11856 struct bbr_sendmap *rsm = NULL;
11857 int32_t tso, mtu;
11858 struct tcpopt to;
11859 int32_t slot = 0;
11860 struct inpcb *inp;
11861 struct sockbuf *sb;
11862 bool hpts_calling;
11863 #ifdef INET6
11864 struct ip6_hdr *ip6 = NULL;
11865 int32_t isipv6;
11866 #endif
11867 uint8_t app_limited = BBR_JR_SENT_DATA;
11868 bbr = (struct tcp_bbr *)tp->t_fb_ptr;
11869 /* We take a cache hit here */
11870 memcpy(&bbr->rc_tv, tv, sizeof(struct timeval));
11871 cts = tcp_tv_to_usec(&bbr->rc_tv);
11872 inp = bbr->rc_inp;
11873 hpts_calling = !!(tp->t_flags2 & TF2_HPTS_CALLS);
11874 tp->t_flags2 &= ~TF2_HPTS_CALLS;
11875 so = inp->inp_socket;
11876 sb = &so->so_snd;
11877 if (tp->t_nic_ktls_xmit)
11878 hw_tls = 1;
11879 else
11880 hw_tls = 0;
11881 kern_prefetch(sb, &maxseg);
11882 maxseg = tp->t_maxseg - bbr->rc_last_options;
11883 if (bbr_minseg(bbr) < maxseg) {
11884 tcp_bbr_tso_size_check(bbr, cts);
11885 }
11886 /* Remove any flags that indicate we are pacing on the inp */
11887 pace_max_segs = bbr->r_ctl.rc_pace_max_segs;
11888 p_maxseg = min(maxseg, pace_max_segs);
11889 INP_WLOCK_ASSERT(inp);
11890 #ifdef TCP_OFFLOAD
11891 if (tp->t_flags & TF_TOE)
11892 return (tcp_offload_output(tp));
11893 #endif
11894
11895 #ifdef INET6
11896 if (bbr->r_state) {
11897 /* Use the cache line loaded if possible */
11898 isipv6 = bbr->r_is_v6;
11899 } else {
11900 isipv6 = (inp->inp_vflag & INP_IPV6) != 0;
11901 }
11902 #endif
11903 if (((bbr->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT) == 0) &&
11904 tcp_in_hpts(tp)) {
11905 /*
11906 * We are on the hpts for some timer but not hptsi output.
11907 * Possibly remove from the hpts so we can send/recv etc.
11908 */
11909 if ((tp->t_flags & TF_ACKNOW) == 0) {
11910 /*
11911 * No immediate demand right now to send an ack, but
11912 * the user may have read, making room for new data
11913 * (a window update). If so we may want to cancel
11914 * whatever timer is running (KEEP/DEL-ACK?) and
11915 * continue to send out a window update. Or we may
11916 * have gotten more data into the socket buffer to
11917 * send.
11918 */
11919 recwin = lmin(lmax(sbspace(&so->so_rcv), 0),
11920 (long)TCP_MAXWIN << tp->rcv_scale);
11921 if ((bbr_window_update_needed(tp, so, recwin, maxseg) == 0) &&
11922 ((tcp_outflags[tp->t_state] & TH_RST) == 0) &&
11923 ((sbavail(sb) + ((tcp_outflags[tp->t_state] & TH_FIN) ? 1 : 0)) <=
11924 (tp->snd_max - tp->snd_una))) {
11925 /*
11926 * Nothing new to send and no window update
11927 * is needed to send. Lets just return and
11928 * let the timer-run off.
11929 */
11930 return (0);
11931 }
11932 }
11933 tcp_hpts_remove(tp);
11934 bbr_timer_cancel(bbr, __LINE__, cts);
11935 }
11936 if (bbr->r_ctl.rc_last_delay_val) {
11937 /* Calculate a rough delay for early escape to sending */
11938 if (SEQ_GT(cts, bbr->rc_pacer_started))
11939 delay_calc = cts - bbr->rc_pacer_started;
11940 if (delay_calc >= bbr->r_ctl.rc_last_delay_val)
11941 delay_calc -= bbr->r_ctl.rc_last_delay_val;
11942 else
11943 delay_calc = 0;
11944 }
11945 /* Mark that we have called bbr_output(). */
11946 if ((bbr->r_timer_override) ||
11947 (tp->t_state < TCPS_ESTABLISHED)) {
11948 /* Timeouts or early states are exempt */
11949 if (tcp_in_hpts(tp))
11950 tcp_hpts_remove(tp);
11951 } else if (tcp_in_hpts(tp)) {
11952 if ((bbr->r_ctl.rc_last_delay_val) &&
11953 (bbr->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT) &&
11954 delay_calc) {
11955 /*
11956 * We were being paced for output and the delay has
11957 * already exceeded when we were supposed to be
11958 * called, lets go ahead and pull out of the hpts
11959 * and call output.
11960 */
11961 counter_u64_add(bbr_out_size[TCP_MSS_ACCT_LATE], 1);
11962 bbr->r_ctl.rc_last_delay_val = 0;
11963 tcp_hpts_remove(tp);
11964 } else if (tp->t_state == TCPS_CLOSED) {
11965 bbr->r_ctl.rc_last_delay_val = 0;
11966 tcp_hpts_remove(tp);
11967 } else {
11968 /*
11969 * On the hpts, you shall not pass! even if ACKNOW
11970 * is on, we will when the hpts fires, unless of
11971 * course we are overdue.
11972 */
11973 counter_u64_add(bbr_out_size[TCP_MSS_ACCT_INPACE], 1);
11974 return (0);
11975 }
11976 }
11977 bbr->rc_cwnd_limited = 0;
11978 if (bbr->r_ctl.rc_last_delay_val) {
11979 /* recalculate the real delay and deal with over/under */
11980 if (SEQ_GT(cts, bbr->rc_pacer_started))
11981 delay_calc = cts - bbr->rc_pacer_started;
11982 else
11983 delay_calc = 0;
11984 if (delay_calc >= bbr->r_ctl.rc_last_delay_val)
11985 /* Setup the delay which will be added in */
11986 delay_calc -= bbr->r_ctl.rc_last_delay_val;
11987 else {
11988 /*
11989 * We are early setup to adjust
11990 * our slot time.
11991 */
11992 uint64_t merged_val;
11993
11994 bbr->r_ctl.rc_agg_early += (bbr->r_ctl.rc_last_delay_val - delay_calc);
11995 bbr->r_agg_early_set = 1;
11996 if (bbr->r_ctl.rc_hptsi_agg_delay) {
11997 if (bbr->r_ctl.rc_hptsi_agg_delay >= bbr->r_ctl.rc_agg_early) {
11998 /* Nope our previous late cancels out the early */
11999 bbr->r_ctl.rc_hptsi_agg_delay -= bbr->r_ctl.rc_agg_early;
12000 bbr->r_agg_early_set = 0;
12001 bbr->r_ctl.rc_agg_early = 0;
12002 } else {
12003 bbr->r_ctl.rc_agg_early -= bbr->r_ctl.rc_hptsi_agg_delay;
12004 bbr->r_ctl.rc_hptsi_agg_delay = 0;
12005 }
12006 }
12007 merged_val = bbr->rc_pacer_started;
12008 merged_val <<= 32;
12009 merged_val |= bbr->r_ctl.rc_last_delay_val;
12010 bbr_log_pacing_delay_calc(bbr, hpts_calling,
12011 bbr->r_ctl.rc_agg_early, cts, delay_calc, merged_val,
12012 bbr->r_agg_early_set, 3);
12013 bbr->r_ctl.rc_last_delay_val = 0;
12014 BBR_STAT_INC(bbr_early);
12015 delay_calc = 0;
12016 }
12017 } else {
12018 /* We were not delayed due to hptsi */
12019 if (bbr->r_agg_early_set)
12020 bbr->r_ctl.rc_agg_early = 0;
12021 bbr->r_agg_early_set = 0;
12022 delay_calc = 0;
12023 }
12024 if (delay_calc) {
12025 /*
12026 * We had a hptsi delay which means we are falling behind on
12027 * sending at the expected rate. Calculate an extra amount
12028 * of data we can send, if any, to put us back on track.
12029 */
12030 if ((bbr->r_ctl.rc_hptsi_agg_delay + delay_calc) < bbr->r_ctl.rc_hptsi_agg_delay)
12031 bbr->r_ctl.rc_hptsi_agg_delay = 0xffffffff;
12032 else
12033 bbr->r_ctl.rc_hptsi_agg_delay += delay_calc;
12034 }
12035 sendwin = min(tp->snd_wnd, tp->snd_cwnd);
12036 if ((tp->snd_una == tp->snd_max) &&
12037 (bbr->rc_bbr_state != BBR_STATE_IDLE_EXIT) &&
12038 (sbavail(sb))) {
12039 /*
12040 * Ok we have been idle with nothing outstanding
12041 * we possibly need to start fresh with either a new
12042 * suite of states or a fast-ramp up.
12043 */
12044 bbr_restart_after_idle(bbr,
12045 cts, bbr_calc_time(cts, bbr->r_ctl.rc_went_idle_time));
12046 }
12047 /*
12048 * Now was there a hptsi delay where we are behind? We only count
12049 * being behind if: a) We are not in recovery. b) There was a delay.
12050 * <and> c) We had room to send something.
12051 *
12052 */
12053 if (bbr->r_ctl.rc_hpts_flags & PACE_TMR_MASK) {
12054 int retval;
12055
12056 retval = bbr_process_timers(tp, bbr, cts, hpts_calling);
12057 if (retval != 0) {
12058 counter_u64_add(bbr_out_size[TCP_MSS_ACCT_ATIMER], 1);
12059 /*
12060 * If timers want tcp_drop(), then pass error out,
12061 * otherwise suppress it.
12062 */
12063 return (retval < 0 ? retval : 0);
12064 }
12065 }
12066 bbr->rc_tp->t_flags2 &= ~TF2_MBUF_QUEUE_READY;
12067 if (hpts_calling &&
12068 (bbr->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT)) {
12069 bbr->r_ctl.rc_last_delay_val = 0;
12070 }
12071 bbr->r_timer_override = 0;
12072 bbr->r_wanted_output = 0;
12073 /*
12074 * For TFO connections in SYN_RECEIVED, only allow the initial
12075 * SYN|ACK and those sent by the retransmit timer.
12076 */
12077 if ((tp->t_flags & TF_FASTOPEN) &&
12078 ((tp->t_state == TCPS_SYN_RECEIVED) ||
12079 (tp->t_state == TCPS_SYN_SENT)) &&
12080 SEQ_GT(tp->snd_max, tp->snd_una) && /* initial SYN or SYN|ACK sent */
12081 (tp->t_rxtshift == 0)) { /* not a retransmit */
12082 len = 0;
12083 goto just_return_nolock;
12084 }
12085 /*
12086 * Before sending anything check for a state update. For hpts
12087 * calling without input this is important. If its input calling
12088 * then this was already done.
12089 */
12090 if (bbr->rc_use_google == 0)
12091 bbr_check_bbr_for_state(bbr, cts, __LINE__, 0);
12092 again:
12093 /*
12094 * If we've recently taken a timeout, snd_max will be greater than
12095 * snd_max. BBR in general does not pay much attention to snd_nxt
12096 * for historic reasons the persist timer still uses it. This means
12097 * we have to look at it. All retransmissions that are not persits
12098 * use the rsm that needs to be sent so snd_nxt is ignored. At the
12099 * end of this routine we pull snd_nxt always up to snd_max.
12100 */
12101 doing_tlp = 0;
12102 #ifdef BBR_INVARIANTS
12103 doing_retran_from = picked_up_retran = 0;
12104 #endif
12105 error = 0;
12106 tso = 0;
12107 slot = 0;
12108 mtu = 0;
12109 sendwin = min(tp->snd_wnd, tp->snd_cwnd);
12110 sb_offset = tp->snd_max - tp->snd_una;
12111 flags = tcp_outflags[tp->t_state];
12112 sack_rxmit = 0;
12113 len = 0;
12114 rsm = NULL;
12115 if (flags & TH_RST) {
12116 SOCK_SENDBUF_LOCK(so);
12117 goto send;
12118 }
12119 recheck_resend:
12120 while (bbr->r_ctl.rc_free_cnt < bbr_min_req_free) {
12121 /* We need to always have one in reserve */
12122 rsm = bbr_alloc(bbr);
12123 if (rsm == NULL) {
12124 error = ENOMEM;
12125 /* Lie to get on the hpts */
12126 tot_len = tp->t_maxseg;
12127 if (hpts_calling)
12128 /* Retry in a ms */
12129 slot = 1001;
12130 goto just_return_nolock;
12131 }
12132 TAILQ_INSERT_TAIL(&bbr->r_ctl.rc_free, rsm, r_next);
12133 bbr->r_ctl.rc_free_cnt++;
12134 rsm = NULL;
12135 }
12136 /* What do we send, a resend? */
12137 if (bbr->r_ctl.rc_resend == NULL) {
12138 /* Check for rack timeout */
12139 bbr->r_ctl.rc_resend = bbr_check_recovery_mode(tp, bbr, cts);
12140 if (bbr->r_ctl.rc_resend) {
12141 #ifdef BBR_INVARIANTS
12142 picked_up_retran = 1;
12143 #endif
12144 bbr_cong_signal(tp, NULL, CC_NDUPACK, bbr->r_ctl.rc_resend);
12145 }
12146 }
12147 if (bbr->r_ctl.rc_resend) {
12148 rsm = bbr->r_ctl.rc_resend;
12149 #ifdef BBR_INVARIANTS
12150 doing_retran_from = 1;
12151 #endif
12152 /* Remove any TLP flags its a RACK or T-O */
12153 rsm->r_flags &= ~BBR_TLP;
12154 bbr->r_ctl.rc_resend = NULL;
12155 if (SEQ_LT(rsm->r_start, tp->snd_una)) {
12156 #ifdef BBR_INVARIANTS
12157 panic("Huh, tp:%p bbr:%p rsm:%p start:%u < snd_una:%u\n",
12158 tp, bbr, rsm, rsm->r_start, tp->snd_una);
12159 goto recheck_resend;
12160 #else
12161 /* TSNH */
12162 rsm = NULL;
12163 goto recheck_resend;
12164 #endif
12165 }
12166 if (rsm->r_flags & BBR_HAS_SYN) {
12167 /* Only retransmit a SYN by itself */
12168 len = 0;
12169 if ((flags & TH_SYN) == 0) {
12170 /* Huh something is wrong */
12171 rsm->r_start++;
12172 if (rsm->r_start == rsm->r_end) {
12173 /* Clean it up, somehow we missed the ack? */
12174 bbr_log_syn(tp, NULL);
12175 } else {
12176 /* TFO with data? */
12177 rsm->r_flags &= ~BBR_HAS_SYN;
12178 len = rsm->r_end - rsm->r_start;
12179 }
12180 } else {
12181 /* Retransmitting SYN */
12182 rsm = NULL;
12183 SOCK_SENDBUF_LOCK(so);
12184 goto send;
12185 }
12186 } else
12187 len = rsm->r_end - rsm->r_start;
12188 if ((bbr->rc_resends_use_tso == 0) &&
12189 (len > maxseg)) {
12190 len = maxseg;
12191 more_to_rxt = 1;
12192 }
12193 sb_offset = rsm->r_start - tp->snd_una;
12194 if (len > 0) {
12195 sack_rxmit = 1;
12196 KMOD_TCPSTAT_INC(tcps_sack_rexmits);
12197 KMOD_TCPSTAT_ADD(tcps_sack_rexmit_bytes,
12198 min(len, maxseg));
12199 } else {
12200 /* I dont think this can happen */
12201 rsm = NULL;
12202 goto recheck_resend;
12203 }
12204 BBR_STAT_INC(bbr_resends_set);
12205 } else if (bbr->r_ctl.rc_tlp_send) {
12206 /*
12207 * Tail loss probe
12208 */
12209 doing_tlp = 1;
12210 rsm = bbr->r_ctl.rc_tlp_send;
12211 bbr->r_ctl.rc_tlp_send = NULL;
12212 sack_rxmit = 1;
12213 len = rsm->r_end - rsm->r_start;
12214 if ((bbr->rc_resends_use_tso == 0) && (len > maxseg))
12215 len = maxseg;
12216
12217 if (SEQ_GT(tp->snd_una, rsm->r_start)) {
12218 #ifdef BBR_INVARIANTS
12219 panic("tp:%p bbc:%p snd_una:%u rsm:%p r_start:%u",
12220 tp, bbr, tp->snd_una, rsm, rsm->r_start);
12221 #else
12222 /* TSNH */
12223 rsm = NULL;
12224 goto recheck_resend;
12225 #endif
12226 }
12227 sb_offset = rsm->r_start - tp->snd_una;
12228 BBR_STAT_INC(bbr_tlp_set);
12229 }
12230 /*
12231 * Enforce a connection sendmap count limit if set
12232 * as long as we are not retransmiting.
12233 */
12234 if ((rsm == NULL) &&
12235 (V_tcp_map_entries_limit > 0) &&
12236 (bbr->r_ctl.rc_num_maps_alloced >= V_tcp_map_entries_limit)) {
12237 BBR_STAT_INC(bbr_alloc_limited);
12238 if (!bbr->alloc_limit_reported) {
12239 bbr->alloc_limit_reported = 1;
12240 BBR_STAT_INC(bbr_alloc_limited_conns);
12241 }
12242 goto just_return_nolock;
12243 }
12244 #ifdef BBR_INVARIANTS
12245 if (rsm && SEQ_LT(rsm->r_start, tp->snd_una)) {
12246 panic("tp:%p bbr:%p rsm:%p sb_offset:%u len:%u",
12247 tp, bbr, rsm, sb_offset, len);
12248 }
12249 #endif
12250 /*
12251 * Get standard flags, and add SYN or FIN if requested by 'hidden'
12252 * state flags.
12253 */
12254 if (tp->t_flags & TF_NEEDFIN && (rsm == NULL))
12255 flags |= TH_FIN;
12256 if (tp->t_flags & TF_NEEDSYN)
12257 flags |= TH_SYN;
12258
12259 if (rsm && (rsm->r_flags & BBR_HAS_FIN)) {
12260 /* we are retransmitting the fin */
12261 len--;
12262 if (len) {
12263 /*
12264 * When retransmitting data do *not* include the
12265 * FIN. This could happen from a TLP probe if we
12266 * allowed data with a FIN.
12267 */
12268 flags &= ~TH_FIN;
12269 }
12270 } else if (rsm) {
12271 if (flags & TH_FIN)
12272 flags &= ~TH_FIN;
12273 }
12274 if ((sack_rxmit == 0) && (prefetch_rsm == 0)) {
12275 void *end_rsm;
12276
12277 end_rsm = TAILQ_LAST_FAST(&bbr->r_ctl.rc_tmap, bbr_sendmap, r_tnext);
12278 if (end_rsm)
12279 kern_prefetch(end_rsm, &prefetch_rsm);
12280 prefetch_rsm = 1;
12281 }
12282 SOCK_SENDBUF_LOCK(so);
12283 /*
12284 * If snd_nxt == snd_max and we have transmitted a FIN, the
12285 * sb_offset will be > 0 even if so_snd.sb_cc is 0, resulting in a
12286 * negative length. This can also occur when TCP opens up its
12287 * congestion window while receiving additional duplicate acks after
12288 * fast-retransmit because TCP will reset snd_nxt to snd_max after
12289 * the fast-retransmit.
12290 *
12291 * In the normal retransmit-FIN-only case, however, snd_nxt will be
12292 * set to snd_una, the sb_offset will be 0, and the length may wind
12293 * up 0.
12294 *
12295 * If sack_rxmit is true we are retransmitting from the scoreboard
12296 * in which case len is already set.
12297 */
12298 if (sack_rxmit == 0) {
12299 uint32_t avail;
12300
12301 avail = sbavail(sb);
12302 if (SEQ_GT(tp->snd_max, tp->snd_una))
12303 sb_offset = tp->snd_max - tp->snd_una;
12304 else
12305 sb_offset = 0;
12306 if (bbr->rc_tlp_new_data) {
12307 /* TLP is forcing out new data */
12308 uint32_t tlplen;
12309
12310 doing_tlp = 1;
12311 tlplen = maxseg;
12312
12313 if (tlplen > (uint32_t)(avail - sb_offset)) {
12314 tlplen = (uint32_t)(avail - sb_offset);
12315 }
12316 if (tlplen > tp->snd_wnd) {
12317 len = tp->snd_wnd;
12318 } else {
12319 len = tlplen;
12320 }
12321 bbr->rc_tlp_new_data = 0;
12322 } else {
12323 len = bbr_what_can_we_send(tp, bbr, sendwin, avail, sb_offset, cts);
12324 if ((len < p_maxseg) &&
12325 (bbr->rc_in_persist == 0) &&
12326 (ctf_outstanding(tp) >= (2 * p_maxseg)) &&
12327 ((avail - sb_offset) >= p_maxseg)) {
12328 /*
12329 * We are not completing whats in the socket
12330 * buffer (i.e. there is at least a segment
12331 * waiting to send) and we have 2 or more
12332 * segments outstanding. There is no sense
12333 * of sending a little piece. Lets defer and
12334 * and wait until we can send a whole
12335 * segment.
12336 */
12337 len = 0;
12338 }
12339 if (bbr->rc_in_persist) {
12340 /*
12341 * We are in persists, figure out if
12342 * a retransmit is available (maybe the previous
12343 * persists we sent) or if we have to send new
12344 * data.
12345 */
12346 rsm = TAILQ_FIRST(&bbr->r_ctl.rc_map);
12347 if (rsm) {
12348 len = rsm->r_end - rsm->r_start;
12349 if (rsm->r_flags & BBR_HAS_FIN)
12350 len--;
12351 if ((bbr->rc_resends_use_tso == 0) && (len > maxseg))
12352 len = maxseg;
12353 if (len > 1)
12354 BBR_STAT_INC(bbr_persist_reneg);
12355 /*
12356 * XXXrrs we could force the len to
12357 * 1 byte here to cause the chunk to
12358 * split apart.. but that would then
12359 * mean we always retransmit it as
12360 * one byte even after the window
12361 * opens.
12362 */
12363 sack_rxmit = 1;
12364 sb_offset = rsm->r_start - tp->snd_una;
12365 } else {
12366 /*
12367 * First time through in persists or peer
12368 * acked our one byte. Though we do have
12369 * to have something in the sb.
12370 */
12371 len = 1;
12372 sb_offset = 0;
12373 if (avail == 0)
12374 len = 0;
12375 }
12376 }
12377 }
12378 }
12379 if (prefetch_so_done == 0) {
12380 kern_prefetch(so, &prefetch_so_done);
12381 prefetch_so_done = 1;
12382 }
12383 /*
12384 * Lop off SYN bit if it has already been sent. However, if this is
12385 * SYN-SENT state and if segment contains data and if we don't know
12386 * that foreign host supports TAO, suppress sending segment.
12387 */
12388 if ((flags & TH_SYN) && (rsm == NULL) &&
12389 SEQ_GT(tp->snd_max, tp->snd_una)) {
12390 if (tp->t_state != TCPS_SYN_RECEIVED)
12391 flags &= ~TH_SYN;
12392 /*
12393 * When sending additional segments following a TFO SYN|ACK,
12394 * do not include the SYN bit.
12395 */
12396 if ((tp->t_flags & TF_FASTOPEN) &&
12397 (tp->t_state == TCPS_SYN_RECEIVED))
12398 flags &= ~TH_SYN;
12399 sb_offset--, len++;
12400 if (sbavail(sb) == 0)
12401 len = 0;
12402 } else if ((flags & TH_SYN) && rsm) {
12403 /*
12404 * Subtract one from the len for the SYN being
12405 * retransmitted.
12406 */
12407 len--;
12408 }
12409 /*
12410 * Be careful not to send data and/or FIN on SYN segments. This
12411 * measure is needed to prevent interoperability problems with not
12412 * fully conformant TCP implementations.
12413 */
12414 if ((flags & TH_SYN) && (tp->t_flags & TF_NOOPT)) {
12415 len = 0;
12416 flags &= ~TH_FIN;
12417 }
12418 /*
12419 * On TFO sockets, ensure no data is sent in the following cases:
12420 *
12421 * - When retransmitting SYN|ACK on a passively-created socket
12422 * - When retransmitting SYN on an actively created socket
12423 * - When sending a zero-length cookie (cookie request) on an
12424 * actively created socket
12425 * - When the socket is in the CLOSED state (RST is being sent)
12426 */
12427 if ((tp->t_flags & TF_FASTOPEN) &&
12428 (((flags & TH_SYN) && (tp->t_rxtshift > 0)) ||
12429 ((tp->t_state == TCPS_SYN_SENT) &&
12430 (tp->t_tfo_client_cookie_len == 0)) ||
12431 (flags & TH_RST))) {
12432 len = 0;
12433 sack_rxmit = 0;
12434 rsm = NULL;
12435 }
12436 /* Without fast-open there should never be data sent on a SYN */
12437 if ((flags & TH_SYN) && !(tp->t_flags & TF_FASTOPEN))
12438 len = 0;
12439 if (len <= 0) {
12440 /*
12441 * If FIN has been sent but not acked, but we haven't been
12442 * called to retransmit, len will be < 0. Otherwise, window
12443 * shrank after we sent into it. If window shrank to 0,
12444 * cancel pending retransmit, pull snd_nxt back to (closed)
12445 * window, and set the persist timer if it isn't already
12446 * going. If the window didn't close completely, just wait
12447 * for an ACK.
12448 *
12449 * We also do a general check here to ensure that we will
12450 * set the persist timer when we have data to send, but a
12451 * 0-byte window. This makes sure the persist timer is set
12452 * even if the packet hits one of the "goto send" lines
12453 * below.
12454 */
12455 len = 0;
12456 if ((tp->snd_wnd == 0) &&
12457 (TCPS_HAVEESTABLISHED(tp->t_state)) &&
12458 (tp->snd_una == tp->snd_max) &&
12459 (sb_offset < (int)sbavail(sb))) {
12460 /*
12461 * Not enough room in the rwnd to send
12462 * a paced segment out.
12463 */
12464 bbr_enter_persist(tp, bbr, cts, __LINE__);
12465 }
12466 } else if ((rsm == NULL) &&
12467 (doing_tlp == 0) &&
12468 (len < bbr->r_ctl.rc_pace_max_segs)) {
12469 /*
12470 * We are not sending a full segment for
12471 * some reason. Should we not send anything (think
12472 * sws or persists)?
12473 */
12474 if ((tp->snd_wnd < min((bbr->r_ctl.rc_high_rwnd/2), bbr_minseg(bbr))) &&
12475 (TCPS_HAVEESTABLISHED(tp->t_state)) &&
12476 (len < (int)(sbavail(sb) - sb_offset))) {
12477 /*
12478 * Here the rwnd is less than
12479 * the pacing size, this is not a retransmit,
12480 * we are established and
12481 * the send is not the last in the socket buffer
12482 * lets not send, and possibly enter persists.
12483 */
12484 len = 0;
12485 if (tp->snd_max == tp->snd_una)
12486 bbr_enter_persist(tp, bbr, cts, __LINE__);
12487 } else if ((tp->snd_cwnd >= bbr->r_ctl.rc_pace_max_segs) &&
12488 (ctf_flight_size(tp, (bbr->r_ctl.rc_sacked +
12489 bbr->r_ctl.rc_lost_bytes)) > (2 * maxseg)) &&
12490 (len < (int)(sbavail(sb) - sb_offset)) &&
12491 (len < bbr_minseg(bbr))) {
12492 /*
12493 * Here we are not retransmitting, and
12494 * the cwnd is not so small that we could
12495 * not send at least a min size (rxt timer
12496 * not having gone off), We have 2 segments or
12497 * more already in flight, its not the tail end
12498 * of the socket buffer and the cwnd is blocking
12499 * us from sending out minimum pacing segment size.
12500 * Lets not send anything.
12501 */
12502 bbr->rc_cwnd_limited = 1;
12503 len = 0;
12504 } else if (((tp->snd_wnd - ctf_outstanding(tp)) <
12505 min((bbr->r_ctl.rc_high_rwnd/2), bbr_minseg(bbr))) &&
12506 (ctf_flight_size(tp, (bbr->r_ctl.rc_sacked +
12507 bbr->r_ctl.rc_lost_bytes)) > (2 * maxseg)) &&
12508 (len < (int)(sbavail(sb) - sb_offset)) &&
12509 (TCPS_HAVEESTABLISHED(tp->t_state))) {
12510 /*
12511 * Here we have a send window but we have
12512 * filled it up and we can't send another pacing segment.
12513 * We also have in flight more than 2 segments
12514 * and we are not completing the sb i.e. we allow
12515 * the last bytes of the sb to go out even if
12516 * its not a full pacing segment.
12517 */
12518 len = 0;
12519 }
12520 }
12521 /* len will be >= 0 after this point. */
12522 KASSERT(len >= 0, ("[%s:%d]: len < 0", __func__, __LINE__));
12523 tcp_sndbuf_autoscale(tp, so, sendwin);
12524 /*
12525 *
12526 */
12527 if (bbr->rc_in_persist &&
12528 len &&
12529 (rsm == NULL) &&
12530 (len < min((bbr->r_ctl.rc_high_rwnd/2), bbr->r_ctl.rc_pace_max_segs))) {
12531 /*
12532 * We are in persist, not doing a retransmit and don't have enough space
12533 * yet to send a full TSO. So is it at the end of the sb
12534 * if so we need to send else nuke to 0 and don't send.
12535 */
12536 int sbleft;
12537 if (sbavail(sb) > sb_offset)
12538 sbleft = sbavail(sb) - sb_offset;
12539 else
12540 sbleft = 0;
12541 if (sbleft >= min((bbr->r_ctl.rc_high_rwnd/2), bbr->r_ctl.rc_pace_max_segs)) {
12542 /* not at end of sb lets not send */
12543 len = 0;
12544 }
12545 }
12546 /*
12547 * Decide if we can use TCP Segmentation Offloading (if supported by
12548 * hardware).
12549 *
12550 * TSO may only be used if we are in a pure bulk sending state. The
12551 * presence of TCP-MD5, SACK retransmits, SACK advertizements and IP
12552 * options prevent using TSO. With TSO the TCP header is the same
12553 * (except for the sequence number) for all generated packets. This
12554 * makes it impossible to transmit any options which vary per
12555 * generated segment or packet.
12556 *
12557 * IPv4 handling has a clear separation of ip options and ip header
12558 * flags while IPv6 combines both in in6p_outputopts. ip6_optlen()
12559 * does the right thing below to provide length of just ip options
12560 * and thus checking for ipoptlen is enough to decide if ip options
12561 * are present.
12562 */
12563 #ifdef INET6
12564 if (isipv6)
12565 ipoptlen = ip6_optlen(inp);
12566 else
12567 #endif
12568 if (inp->inp_options)
12569 ipoptlen = inp->inp_options->m_len -
12570 offsetof(struct ipoption, ipopt_list);
12571 else
12572 ipoptlen = 0;
12573 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
12574 /*
12575 * Pre-calculate here as we save another lookup into the darknesses
12576 * of IPsec that way and can actually decide if TSO is ok.
12577 */
12578 #ifdef INET6
12579 if (isipv6 && IPSEC_ENABLED(ipv6))
12580 ipsec_optlen = IPSEC_HDRSIZE(ipv6, inp);
12581 #ifdef INET
12582 else
12583 #endif
12584 #endif /* INET6 */
12585 #ifdef INET
12586 if (IPSEC_ENABLED(ipv4))
12587 ipsec_optlen = IPSEC_HDRSIZE(ipv4, inp);
12588 #endif /* INET */
12589 #endif /* IPSEC */
12590 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
12591 ipoptlen += ipsec_optlen;
12592 #endif
12593 if ((tp->t_flags & TF_TSO) && V_tcp_do_tso &&
12594 (len > maxseg) &&
12595 (tp->t_port == 0) &&
12596 ((tp->t_flags & TF_SIGNATURE) == 0) &&
12597 ipoptlen == 0)
12598 tso = 1;
12599
12600 recwin = lmin(lmax(sbspace(&so->so_rcv), 0),
12601 (long)TCP_MAXWIN << tp->rcv_scale);
12602 /*
12603 * Sender silly window avoidance. We transmit under the following
12604 * conditions when len is non-zero:
12605 *
12606 * - We have a full segment (or more with TSO) - This is the last
12607 * buffer in a write()/send() and we are either idle or running
12608 * NODELAY - we've timed out (e.g. persist timer) - we have more
12609 * then 1/2 the maximum send window's worth of data (receiver may be
12610 * limited the window size) - we need to retransmit
12611 */
12612 if (rsm)
12613 goto send;
12614 if (len) {
12615 if (sack_rxmit)
12616 goto send;
12617 if (len >= p_maxseg)
12618 goto send;
12619 /*
12620 * NOTE! on localhost connections an 'ack' from the remote
12621 * end may occur synchronously with the output and cause us
12622 * to flush a buffer queued with moretocome. XXX
12623 *
12624 */
12625 if (((tp->t_flags & TF_MORETOCOME) == 0) && /* normal case */
12626 ((tp->t_flags & TF_NODELAY) ||
12627 ((uint32_t)len + (uint32_t)sb_offset) >= sbavail(&so->so_snd)) &&
12628 (tp->t_flags & TF_NOPUSH) == 0) {
12629 goto send;
12630 }
12631 if ((tp->snd_una == tp->snd_max) && len) { /* Nothing outstanding */
12632 goto send;
12633 }
12634 if (len >= tp->max_sndwnd / 2 && tp->max_sndwnd > 0) {
12635 goto send;
12636 }
12637 }
12638 /*
12639 * Sending of standalone window updates.
12640 *
12641 * Window updates are important when we close our window due to a
12642 * full socket buffer and are opening it again after the application
12643 * reads data from it. Once the window has opened again and the
12644 * remote end starts to send again the ACK clock takes over and
12645 * provides the most current window information.
12646 *
12647 * We must avoid the silly window syndrome whereas every read from
12648 * the receive buffer, no matter how small, causes a window update
12649 * to be sent. We also should avoid sending a flurry of window
12650 * updates when the socket buffer had queued a lot of data and the
12651 * application is doing small reads.
12652 *
12653 * Prevent a flurry of pointless window updates by only sending an
12654 * update when we can increase the advertized window by more than
12655 * 1/4th of the socket buffer capacity. When the buffer is getting
12656 * full or is very small be more aggressive and send an update
12657 * whenever we can increase by two mss sized segments. In all other
12658 * situations the ACK's to new incoming data will carry further
12659 * window increases.
12660 *
12661 * Don't send an independent window update if a delayed ACK is
12662 * pending (it will get piggy-backed on it) or the remote side
12663 * already has done a half-close and won't send more data. Skip
12664 * this if the connection is in T/TCP half-open state.
12665 */
12666 if (recwin > 0 && !(tp->t_flags & TF_NEEDSYN) &&
12667 !(tp->t_flags & TF_DELACK) &&
12668 !TCPS_HAVERCVDFIN(tp->t_state)) {
12669 /* Check to see if we should do a window update */
12670 if (bbr_window_update_needed(tp, so, recwin, maxseg))
12671 goto send;
12672 }
12673 /*
12674 * Send if we owe the peer an ACK, RST, SYN. ACKNOW
12675 * is also a catch-all for the retransmit timer timeout case.
12676 */
12677 if (tp->t_flags & TF_ACKNOW) {
12678 goto send;
12679 }
12680 if (flags & TH_RST) {
12681 /* Always send a RST if one is due */
12682 goto send;
12683 }
12684 if ((flags & TH_SYN) && (tp->t_flags & TF_NEEDSYN) == 0) {
12685 goto send;
12686 }
12687 /*
12688 * If our state indicates that FIN should be sent and we have not
12689 * yet done so, then we need to send.
12690 */
12691 if (flags & TH_FIN &&
12692 ((tp->t_flags & TF_SENTFIN) == 0)) {
12693 goto send;
12694 }
12695 /*
12696 * No reason to send a segment, just return.
12697 */
12698 just_return:
12699 SOCK_SENDBUF_UNLOCK(so);
12700 just_return_nolock:
12701 if (tot_len)
12702 slot = bbr_get_pacing_delay(bbr, bbr->r_ctl.rc_bbr_hptsi_gain, tot_len, cts, 0);
12703 if (bbr->rc_no_pacing)
12704 slot = 0;
12705 if (tot_len == 0) {
12706 if ((ctf_outstanding(tp) + min((bbr->r_ctl.rc_high_rwnd/2), bbr_minseg(bbr))) >=
12707 tp->snd_wnd) {
12708 BBR_STAT_INC(bbr_rwnd_limited);
12709 app_limited = BBR_JR_RWND_LIMITED;
12710 bbr_cwnd_limiting(tp, bbr, ctf_outstanding(tp));
12711 if ((bbr->rc_in_persist == 0) &&
12712 TCPS_HAVEESTABLISHED(tp->t_state) &&
12713 (tp->snd_max == tp->snd_una) &&
12714 sbavail(&so->so_snd)) {
12715 /* No send window.. we must enter persist */
12716 bbr_enter_persist(tp, bbr, bbr->r_ctl.rc_rcvtime, __LINE__);
12717 }
12718 } else if (ctf_outstanding(tp) >= sbavail(sb)) {
12719 BBR_STAT_INC(bbr_app_limited);
12720 app_limited = BBR_JR_APP_LIMITED;
12721 bbr_cwnd_limiting(tp, bbr, ctf_outstanding(tp));
12722 } else if ((ctf_flight_size(tp, (bbr->r_ctl.rc_sacked +
12723 bbr->r_ctl.rc_lost_bytes)) + p_maxseg) >= tp->snd_cwnd) {
12724 BBR_STAT_INC(bbr_cwnd_limited);
12725 app_limited = BBR_JR_CWND_LIMITED;
12726 bbr_cwnd_limiting(tp, bbr, ctf_flight_size(tp, (bbr->r_ctl.rc_sacked +
12727 bbr->r_ctl.rc_lost_bytes)));
12728 bbr->rc_cwnd_limited = 1;
12729 } else {
12730 BBR_STAT_INC(bbr_app_limited);
12731 app_limited = BBR_JR_APP_LIMITED;
12732 bbr_cwnd_limiting(tp, bbr, ctf_outstanding(tp));
12733 }
12734 bbr->r_ctl.rc_hptsi_agg_delay = 0;
12735 bbr->r_agg_early_set = 0;
12736 bbr->r_ctl.rc_agg_early = 0;
12737 bbr->r_ctl.rc_last_delay_val = 0;
12738 } else if (bbr->rc_use_google == 0)
12739 bbr_check_bbr_for_state(bbr, cts, __LINE__, 0);
12740 /* Are we app limited? */
12741 if ((app_limited == BBR_JR_APP_LIMITED) ||
12742 (app_limited == BBR_JR_RWND_LIMITED)) {
12743 /**
12744 * We are application limited.
12745 */
12746 bbr->r_ctl.r_app_limited_until = (ctf_flight_size(tp, (bbr->r_ctl.rc_sacked +
12747 bbr->r_ctl.rc_lost_bytes)) + bbr->r_ctl.rc_delivered);
12748 }
12749 if (tot_len == 0)
12750 counter_u64_add(bbr_out_size[TCP_MSS_ACCT_JUSTRET], 1);
12751 /* Dont update the time if we did not send */
12752 bbr->r_ctl.rc_last_delay_val = 0;
12753 bbr->rc_output_starts_timer = 1;
12754 bbr_start_hpts_timer(bbr, tp, cts, 9, slot, tot_len);
12755 bbr_log_type_just_return(bbr, cts, tot_len, hpts_calling, app_limited, p_maxseg, len);
12756 if (SEQ_LT(tp->snd_nxt, tp->snd_max)) {
12757 /* Make sure snd_nxt is drug up */
12758 tp->snd_nxt = tp->snd_max;
12759 }
12760 return (error);
12761
12762 send:
12763 if (doing_tlp == 0) {
12764 /*
12765 * Data not a TLP, and its not the rxt firing. If it is the
12766 * rxt firing, we want to leave the tlp_in_progress flag on
12767 * so we don't send another TLP. It has to be a rack timer
12768 * or normal send (response to acked data) to clear the tlp
12769 * in progress flag.
12770 */
12771 bbr->rc_tlp_in_progress = 0;
12772 bbr->rc_tlp_rtx_out = 0;
12773 } else {
12774 /*
12775 * Its a TLP.
12776 */
12777 bbr->rc_tlp_in_progress = 1;
12778 }
12779 bbr_timer_cancel(bbr, __LINE__, cts);
12780 if (rsm == NULL) {
12781 if (sbused(sb) > 0) {
12782 /*
12783 * This is sub-optimal. We only send a stand alone
12784 * FIN on its own segment.
12785 */
12786 if (flags & TH_FIN) {
12787 flags &= ~TH_FIN;
12788 if ((len == 0) && ((tp->t_flags & TF_ACKNOW) == 0)) {
12789 /* Lets not send this */
12790 slot = 0;
12791 goto just_return;
12792 }
12793 }
12794 }
12795 } else {
12796 /*
12797 * We do *not* send a FIN on a retransmit if it has data.
12798 * The if clause here where len > 1 should never come true.
12799 */
12800 if ((len > 0) &&
12801 (((rsm->r_flags & BBR_HAS_FIN) == 0) &&
12802 (flags & TH_FIN))) {
12803 flags &= ~TH_FIN;
12804 len--;
12805 }
12806 }
12807 SOCK_SENDBUF_LOCK_ASSERT(so);
12808 if (len > 0) {
12809 if ((tp->snd_una == tp->snd_max) &&
12810 (bbr_calc_time(cts, bbr->r_ctl.rc_went_idle_time) >= bbr_rtt_probe_time)) {
12811 /*
12812 * This qualifies as a RTT_PROBE session since we
12813 * drop the data outstanding to nothing and waited
12814 * more than bbr_rtt_probe_time.
12815 */
12816 bbr_log_rtt_shrinks(bbr, cts, 0, 0, __LINE__, BBR_RTTS_WASIDLE, 0);
12817 bbr_set_reduced_rtt(bbr, cts, __LINE__);
12818 }
12819 if (len >= maxseg)
12820 tp->t_flags2 |= TF2_PLPMTU_MAXSEGSNT;
12821 else
12822 tp->t_flags2 &= ~TF2_PLPMTU_MAXSEGSNT;
12823 }
12824 /*
12825 * Before ESTABLISHED, force sending of initial options unless TCP
12826 * set not to do any options. NOTE: we assume that the IP/TCP header
12827 * plus TCP options always fit in a single mbuf, leaving room for a
12828 * maximum link header, i.e. max_linkhdr + sizeof (struct tcpiphdr)
12829 * + optlen <= MCLBYTES
12830 */
12831 optlen = 0;
12832 #ifdef INET6
12833 if (isipv6)
12834 hdrlen = sizeof(struct ip6_hdr) + sizeof(struct tcphdr);
12835 else
12836 #endif
12837 hdrlen = sizeof(struct tcpiphdr);
12838
12839 /*
12840 * Compute options for segment. We only have to care about SYN and
12841 * established connection segments. Options for SYN-ACK segments
12842 * are handled in TCP syncache.
12843 */
12844 to.to_flags = 0;
12845 local_options = 0;
12846 if ((tp->t_flags & TF_NOOPT) == 0) {
12847 /* Maximum segment size. */
12848 if (flags & TH_SYN) {
12849 to.to_mss = tcp_mssopt(&inp->inp_inc);
12850 if (tp->t_port)
12851 to.to_mss -= V_tcp_udp_tunneling_overhead;
12852 to.to_flags |= TOF_MSS;
12853 /*
12854 * On SYN or SYN|ACK transmits on TFO connections,
12855 * only include the TFO option if it is not a
12856 * retransmit, as the presence of the TFO option may
12857 * have caused the original SYN or SYN|ACK to have
12858 * been dropped by a middlebox.
12859 */
12860 if ((tp->t_flags & TF_FASTOPEN) &&
12861 (tp->t_rxtshift == 0)) {
12862 if (tp->t_state == TCPS_SYN_RECEIVED) {
12863 to.to_tfo_len = TCP_FASTOPEN_COOKIE_LEN;
12864 to.to_tfo_cookie =
12865 (u_int8_t *)&tp->t_tfo_cookie.server;
12866 to.to_flags |= TOF_FASTOPEN;
12867 wanted_cookie = 1;
12868 } else if (tp->t_state == TCPS_SYN_SENT) {
12869 to.to_tfo_len =
12870 tp->t_tfo_client_cookie_len;
12871 to.to_tfo_cookie =
12872 tp->t_tfo_cookie.client;
12873 to.to_flags |= TOF_FASTOPEN;
12874 wanted_cookie = 1;
12875 }
12876 }
12877 }
12878 /* Window scaling. */
12879 if ((flags & TH_SYN) && (tp->t_flags & TF_REQ_SCALE)) {
12880 to.to_wscale = tp->request_r_scale;
12881 to.to_flags |= TOF_SCALE;
12882 }
12883 /* Timestamps. */
12884 if ((tp->t_flags & TF_RCVD_TSTMP) ||
12885 ((flags & TH_SYN) && (tp->t_flags & TF_REQ_TSTMP))) {
12886 to.to_tsval = tcp_tv_to_msec(&bbr->rc_tv) + tp->ts_offset;
12887 to.to_tsecr = tp->ts_recent;
12888 to.to_flags |= TOF_TS;
12889 local_options += TCPOLEN_TIMESTAMP + 2;
12890 }
12891 /* Set receive buffer autosizing timestamp. */
12892 if (tp->rfbuf_ts == 0 &&
12893 (so->so_rcv.sb_flags & SB_AUTOSIZE))
12894 tp->rfbuf_ts = tcp_tv_to_msec(&bbr->rc_tv);
12895 /* Selective ACK's. */
12896 if (flags & TH_SYN)
12897 to.to_flags |= TOF_SACKPERM;
12898 else if (TCPS_HAVEESTABLISHED(tp->t_state) &&
12899 tp->rcv_numsacks > 0) {
12900 to.to_flags |= TOF_SACK;
12901 to.to_nsacks = tp->rcv_numsacks;
12902 to.to_sacks = (u_char *)tp->sackblks;
12903 }
12904 #if defined(IPSEC_SUPPORT) || defined(TCP_SIGNATURE)
12905 /* TCP-MD5 (RFC2385). */
12906 if (tp->t_flags & TF_SIGNATURE)
12907 to.to_flags |= TOF_SIGNATURE;
12908 #endif /* TCP_SIGNATURE */
12909
12910 /* Processing the options. */
12911 hdrlen += (optlen = tcp_addoptions(&to, opt));
12912 /*
12913 * If we wanted a TFO option to be added, but it was unable
12914 * to fit, ensure no data is sent.
12915 */
12916 if ((tp->t_flags & TF_FASTOPEN) && wanted_cookie &&
12917 !(to.to_flags & TOF_FASTOPEN))
12918 len = 0;
12919 }
12920 if (tp->t_port) {
12921 if (V_tcp_udp_tunneling_port == 0) {
12922 /* The port was removed?? */
12923 SOCK_SENDBUF_UNLOCK(so);
12924 return (EHOSTUNREACH);
12925 }
12926 hdrlen += sizeof(struct udphdr);
12927 }
12928 #ifdef INET6
12929 if (isipv6)
12930 ipoptlen = ip6_optlen(inp);
12931 else
12932 #endif
12933 if (inp->inp_options)
12934 ipoptlen = inp->inp_options->m_len -
12935 offsetof(struct ipoption, ipopt_list);
12936 else
12937 ipoptlen = 0;
12938 ipoptlen = 0;
12939 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
12940 ipoptlen += ipsec_optlen;
12941 #endif
12942 if (bbr->rc_last_options != local_options) {
12943 /*
12944 * Cache the options length this generally does not change
12945 * on a connection. We use this to calculate TSO.
12946 */
12947 bbr->rc_last_options = local_options;
12948 }
12949 maxseg = tp->t_maxseg - (ipoptlen + optlen);
12950 p_maxseg = min(maxseg, pace_max_segs);
12951 /*
12952 * Adjust data length if insertion of options will bump the packet
12953 * length beyond the t_maxseg length. Clear the FIN bit because we
12954 * cut off the tail of the segment.
12955 */
12956 if (len > maxseg) {
12957 if (len != 0 && (flags & TH_FIN)) {
12958 flags &= ~TH_FIN;
12959 }
12960 if (tso) {
12961 uint32_t moff;
12962 int32_t max_len;
12963
12964 /* extract TSO information */
12965 if_hw_tsomax = tp->t_tsomax;
12966 if_hw_tsomaxsegcount = tp->t_tsomaxsegcount;
12967 if_hw_tsomaxsegsize = tp->t_tsomaxsegsize;
12968 KASSERT(ipoptlen == 0,
12969 ("%s: TSO can't do IP options", __func__));
12970
12971 /*
12972 * Check if we should limit by maximum payload
12973 * length:
12974 */
12975 if (if_hw_tsomax != 0) {
12976 /* compute maximum TSO length */
12977 max_len = (if_hw_tsomax - hdrlen -
12978 max_linkhdr);
12979 if (max_len <= 0) {
12980 len = 0;
12981 } else if (len > max_len) {
12982 len = max_len;
12983 }
12984 }
12985 /*
12986 * Prevent the last segment from being fractional
12987 * unless the send sockbuf can be emptied:
12988 */
12989 if ((sb_offset + len) < sbavail(sb)) {
12990 moff = len % (uint32_t)maxseg;
12991 if (moff != 0) {
12992 len -= moff;
12993 }
12994 }
12995 /*
12996 * In case there are too many small fragments don't
12997 * use TSO:
12998 */
12999 if (len <= maxseg) {
13000 len = maxseg;
13001 tso = 0;
13002 }
13003 } else {
13004 /* Not doing TSO */
13005 if (optlen + ipoptlen >= tp->t_maxseg) {
13006 /*
13007 * Since we don't have enough space to put
13008 * the IP header chain and the TCP header in
13009 * one packet as required by RFC 7112, don't
13010 * send it. Also ensure that at least one
13011 * byte of the payload can be put into the
13012 * TCP segment.
13013 */
13014 SOCK_SENDBUF_UNLOCK(so);
13015 error = EMSGSIZE;
13016 sack_rxmit = 0;
13017 goto out;
13018 }
13019 len = maxseg;
13020 }
13021 } else {
13022 /* Not doing TSO */
13023 if_hw_tsomaxsegcount = 0;
13024 tso = 0;
13025 }
13026 KASSERT(len + hdrlen + ipoptlen <= IP_MAXPACKET,
13027 ("%s: len > IP_MAXPACKET", __func__));
13028 #ifdef DIAGNOSTIC
13029 #ifdef INET6
13030 if (max_linkhdr + hdrlen > MCLBYTES)
13031 #else
13032 if (max_linkhdr + hdrlen > MHLEN)
13033 #endif
13034 panic("tcphdr too big");
13035 #endif
13036 /*
13037 * This KASSERT is here to catch edge cases at a well defined place.
13038 * Before, those had triggered (random) panic conditions further
13039 * down.
13040 */
13041 #ifdef BBR_INVARIANTS
13042 if (sack_rxmit) {
13043 if (SEQ_LT(rsm->r_start, tp->snd_una)) {
13044 panic("RSM:%p TP:%p bbr:%p start:%u is < snd_una:%u",
13045 rsm, tp, bbr, rsm->r_start, tp->snd_una);
13046 }
13047 }
13048 #endif
13049 KASSERT(len >= 0, ("[%s:%d]: len < 0", __func__, __LINE__));
13050 if ((len == 0) &&
13051 (flags & TH_FIN) &&
13052 (sbused(sb))) {
13053 /*
13054 * We have outstanding data, don't send a fin by itself!.
13055 */
13056 slot = 0;
13057 goto just_return;
13058 }
13059 /*
13060 * Grab a header mbuf, attaching a copy of data to be transmitted,
13061 * and initialize the header from the template for sends on this
13062 * connection.
13063 */
13064 if (len) {
13065 uint32_t moff;
13066
13067 /*
13068 * We place a limit on sending with hptsi.
13069 */
13070 if ((rsm == NULL) && len > pace_max_segs)
13071 len = pace_max_segs;
13072 if (len <= maxseg)
13073 tso = 0;
13074 #ifdef INET6
13075 if (MHLEN < hdrlen + max_linkhdr)
13076 m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR);
13077 else
13078 #endif
13079 m = m_gethdr(M_NOWAIT, MT_DATA);
13080
13081 if (m == NULL) {
13082 BBR_STAT_INC(bbr_failed_mbuf_aloc);
13083 bbr_log_enobuf_jmp(bbr, len, cts, __LINE__, len, 0, 0);
13084 SOCK_SENDBUF_UNLOCK(so);
13085 error = ENOBUFS;
13086 sack_rxmit = 0;
13087 goto out;
13088 }
13089 m->m_data += max_linkhdr;
13090 m->m_len = hdrlen;
13091 /*
13092 * Start the m_copy functions from the closest mbuf to the
13093 * sb_offset in the socket buffer chain.
13094 */
13095 if ((sb_offset > sbavail(sb)) || ((len + sb_offset) > sbavail(sb))) {
13096 #ifdef BBR_INVARIANTS
13097 if ((len + sb_offset) > (sbavail(sb) + ((flags & (TH_FIN | TH_SYN)) ? 1 : 0)))
13098 panic("tp:%p bbr:%p len:%u sb_offset:%u sbavail:%u rsm:%p %u:%u:%u",
13099 tp, bbr, len, sb_offset, sbavail(sb), rsm,
13100 doing_retran_from,
13101 picked_up_retran,
13102 doing_tlp);
13103
13104 #endif
13105 /*
13106 * In this messed up situation we have two choices,
13107 * a) pretend the send worked, and just start timers
13108 * and what not (not good since that may lead us
13109 * back here a lot). <or> b) Send the lowest segment
13110 * in the map. <or> c) Drop the connection. Lets do
13111 * <b> which if it continues to happen will lead to
13112 * <c> via timeouts.
13113 */
13114 BBR_STAT_INC(bbr_offset_recovery);
13115 rsm = TAILQ_FIRST(&bbr->r_ctl.rc_map);
13116 sb_offset = 0;
13117 if (rsm == NULL) {
13118 sack_rxmit = 0;
13119 len = sbavail(sb);
13120 } else {
13121 sack_rxmit = 1;
13122 if (rsm->r_start != tp->snd_una) {
13123 /*
13124 * Things are really messed up, <c>
13125 * is the only thing to do.
13126 */
13127 BBR_STAT_INC(bbr_offset_drop);
13128 SOCK_SENDBUF_UNLOCK(so);
13129 (void)m_free(m);
13130 return (-EFAULT); /* tcp_drop() */
13131 }
13132 len = rsm->r_end - rsm->r_start;
13133 }
13134 if (len > sbavail(sb))
13135 len = sbavail(sb);
13136 if (len > maxseg)
13137 len = maxseg;
13138 }
13139 mb = sbsndptr_noadv(sb, sb_offset, &moff);
13140 if (len <= MHLEN - hdrlen - max_linkhdr && !hw_tls) {
13141 m_copydata(mb, moff, (int)len,
13142 mtod(m, caddr_t)+hdrlen);
13143 if (rsm == NULL)
13144 sbsndptr_adv(sb, mb, len);
13145 m->m_len += len;
13146 } else {
13147 struct sockbuf *msb;
13148
13149 if (rsm)
13150 msb = NULL;
13151 else
13152 msb = sb;
13153 #ifdef BBR_INVARIANTS
13154 if ((len + moff) > (sbavail(sb) + ((flags & (TH_FIN | TH_SYN)) ? 1 : 0))) {
13155 if (rsm) {
13156 panic("tp:%p bbr:%p len:%u moff:%u sbavail:%u rsm:%p snd_una:%u rsm_start:%u flg:%x %u:%u:%u sr:%d ",
13157 tp, bbr, len, moff,
13158 sbavail(sb), rsm,
13159 tp->snd_una, rsm->r_flags, rsm->r_start,
13160 doing_retran_from,
13161 picked_up_retran,
13162 doing_tlp, sack_rxmit);
13163 } else {
13164 panic("tp:%p bbr:%p len:%u moff:%u sbavail:%u sb_offset:%u snd_una:%u",
13165 tp, bbr, len, moff, sbavail(sb), sb_offset, tp->snd_una);
13166 }
13167 }
13168 #endif
13169 m->m_next = tcp_m_copym(
13170 mb, moff, &len,
13171 if_hw_tsomaxsegcount,
13172 if_hw_tsomaxsegsize, msb,
13173 ((rsm == NULL) ? hw_tls : 0));
13174 if (len <= maxseg) {
13175 /*
13176 * Must have ran out of mbufs for the copy
13177 * shorten it to no longer need tso. Lets
13178 * not put on sendalot since we are low on
13179 * mbufs.
13180 */
13181 tso = 0;
13182 }
13183 if (m->m_next == NULL) {
13184 SOCK_SENDBUF_UNLOCK(so);
13185 (void)m_free(m);
13186 error = ENOBUFS;
13187 sack_rxmit = 0;
13188 goto out;
13189 }
13190 }
13191 #ifdef BBR_INVARIANTS
13192 if (tso && len < maxseg) {
13193 panic("tp:%p tso on, but len:%d < maxseg:%d",
13194 tp, len, maxseg);
13195 }
13196 if (tso && if_hw_tsomaxsegcount) {
13197 int32_t seg_cnt = 0;
13198 struct mbuf *foo;
13199
13200 foo = m;
13201 while (foo) {
13202 seg_cnt++;
13203 foo = foo->m_next;
13204 }
13205 if (seg_cnt > if_hw_tsomaxsegcount) {
13206 panic("seg_cnt:%d > max:%d", seg_cnt, if_hw_tsomaxsegcount);
13207 }
13208 }
13209 #endif
13210 /*
13211 * If we're sending everything we've got, set PUSH. (This
13212 * will keep happy those implementations which only give
13213 * data to the user when a buffer fills or a PUSH comes in.)
13214 */
13215 if (sb_offset + len == sbused(sb) &&
13216 sbused(sb) &&
13217 !(flags & TH_SYN)) {
13218 flags |= TH_PUSH;
13219 }
13220 SOCK_SENDBUF_UNLOCK(so);
13221 } else {
13222 SOCK_SENDBUF_UNLOCK(so);
13223 if (tp->t_flags & TF_ACKNOW)
13224 KMOD_TCPSTAT_INC(tcps_sndacks);
13225 else if (flags & (TH_SYN | TH_FIN | TH_RST))
13226 KMOD_TCPSTAT_INC(tcps_sndctrl);
13227 else
13228 KMOD_TCPSTAT_INC(tcps_sndwinup);
13229
13230 m = m_gethdr(M_NOWAIT, MT_DATA);
13231 if (m == NULL) {
13232 BBR_STAT_INC(bbr_failed_mbuf_aloc);
13233 bbr_log_enobuf_jmp(bbr, len, cts, __LINE__, len, 0, 0);
13234 error = ENOBUFS;
13235 /* Fudge the send time since we could not send */
13236 sack_rxmit = 0;
13237 goto out;
13238 }
13239 #ifdef INET6
13240 if (isipv6 && (MHLEN < hdrlen + max_linkhdr) &&
13241 MHLEN >= hdrlen) {
13242 M_ALIGN(m, hdrlen);
13243 } else
13244 #endif
13245 m->m_data += max_linkhdr;
13246 m->m_len = hdrlen;
13247 }
13248 SOCK_SENDBUF_UNLOCK_ASSERT(so);
13249 m->m_pkthdr.rcvif = (struct ifnet *)0;
13250 #ifdef MAC
13251 mac_inpcb_create_mbuf(inp, m);
13252 #endif
13253 #ifdef INET6
13254 if (isipv6) {
13255 ip6 = mtod(m, struct ip6_hdr *);
13256 if (tp->t_port) {
13257 udp = (struct udphdr *)((caddr_t)ip6 + sizeof(struct ip6_hdr));
13258 udp->uh_sport = htons(V_tcp_udp_tunneling_port);
13259 udp->uh_dport = tp->t_port;
13260 ulen = hdrlen + len - sizeof(struct ip6_hdr);
13261 udp->uh_ulen = htons(ulen);
13262 th = (struct tcphdr *)(udp + 1);
13263 } else {
13264 th = (struct tcphdr *)(ip6 + 1);
13265 }
13266 tcpip_fillheaders(inp, tp->t_port, ip6, th);
13267 } else
13268 #endif /* INET6 */
13269 {
13270 ip = mtod(m, struct ip *);
13271 if (tp->t_port) {
13272 udp = (struct udphdr *)((caddr_t)ip + sizeof(struct ip));
13273 udp->uh_sport = htons(V_tcp_udp_tunneling_port);
13274 udp->uh_dport = tp->t_port;
13275 ulen = hdrlen + len - sizeof(struct ip);
13276 udp->uh_ulen = htons(ulen);
13277 th = (struct tcphdr *)(udp + 1);
13278 } else {
13279 th = (struct tcphdr *)(ip + 1);
13280 }
13281 tcpip_fillheaders(inp, tp->t_port, ip, th);
13282 }
13283 /*
13284 * If we are doing retransmissions, then snd_nxt will not reflect
13285 * the first unsent octet. For ACK only packets, we do not want the
13286 * sequence number of the retransmitted packet, we want the sequence
13287 * number of the next unsent octet. So, if there is no data (and no
13288 * SYN or FIN), use snd_max instead of snd_nxt when filling in
13289 * ti_seq. But if we are in persist state, snd_max might reflect
13290 * one byte beyond the right edge of the window, so use snd_nxt in
13291 * that case, since we know we aren't doing a retransmission.
13292 * (retransmit and persist are mutually exclusive...)
13293 */
13294 if (sack_rxmit == 0) {
13295 if (len && ((flags & (TH_FIN | TH_SYN | TH_RST)) == 0)) {
13296 /* New data (including new persists) */
13297 th->th_seq = htonl(tp->snd_max);
13298 bbr_seq = tp->snd_max;
13299 } else if (flags & TH_SYN) {
13300 /* Syn's always send from iss */
13301 th->th_seq = htonl(tp->iss);
13302 bbr_seq = tp->iss;
13303 } else if (flags & TH_FIN) {
13304 if (flags & TH_FIN && tp->t_flags & TF_SENTFIN) {
13305 /*
13306 * If we sent the fin already its 1 minus
13307 * snd_max
13308 */
13309 th->th_seq = (htonl(tp->snd_max - 1));
13310 bbr_seq = (tp->snd_max - 1);
13311 } else {
13312 /* First time FIN use snd_max */
13313 th->th_seq = htonl(tp->snd_max);
13314 bbr_seq = tp->snd_max;
13315 }
13316 } else {
13317 /*
13318 * len == 0 and not persist we use snd_max, sending
13319 * an ack unless we have sent the fin then its 1
13320 * minus.
13321 */
13322 /*
13323 * XXXRRS Question if we are in persists and we have
13324 * nothing outstanding to send and we have not sent
13325 * a FIN, we will send an ACK. In such a case it
13326 * might be better to send (tp->snd_una - 1) which
13327 * would force the peer to ack.
13328 */
13329 if (tp->t_flags & TF_SENTFIN) {
13330 th->th_seq = htonl(tp->snd_max - 1);
13331 bbr_seq = (tp->snd_max - 1);
13332 } else {
13333 th->th_seq = htonl(tp->snd_max);
13334 bbr_seq = tp->snd_max;
13335 }
13336 }
13337 } else {
13338 /* All retransmits use the rsm to guide the send */
13339 th->th_seq = htonl(rsm->r_start);
13340 bbr_seq = rsm->r_start;
13341 }
13342 th->th_ack = htonl(tp->rcv_nxt);
13343 if (optlen) {
13344 bcopy(opt, th + 1, optlen);
13345 th->th_off = (sizeof(struct tcphdr) + optlen) >> 2;
13346 }
13347 tcp_set_flags(th, flags);
13348 /*
13349 * Calculate receive window. Don't shrink window, but avoid silly
13350 * window syndrome.
13351 */
13352 if ((flags & TH_RST) || ((recwin < (so->so_rcv.sb_hiwat / 4) &&
13353 recwin < maxseg)))
13354 recwin = 0;
13355 if (SEQ_GT(tp->rcv_adv, tp->rcv_nxt) &&
13356 recwin < (tp->rcv_adv - tp->rcv_nxt))
13357 recwin = (tp->rcv_adv - tp->rcv_nxt);
13358 if (recwin > TCP_MAXWIN << tp->rcv_scale)
13359 recwin = TCP_MAXWIN << tp->rcv_scale;
13360
13361 /*
13362 * According to RFC1323 the window field in a SYN (i.e., a <SYN> or
13363 * <SYN,ACK>) segment itself is never scaled. The <SYN,ACK> case is
13364 * handled in syncache.
13365 */
13366 if (flags & TH_SYN)
13367 th->th_win = htons((u_short)
13368 (min(sbspace(&so->so_rcv), TCP_MAXWIN)));
13369 else {
13370 /* Avoid shrinking window with window scaling. */
13371 recwin = roundup2(recwin, 1 << tp->rcv_scale);
13372 th->th_win = htons((u_short)(recwin >> tp->rcv_scale));
13373 }
13374 /*
13375 * Adjust the RXWIN0SENT flag - indicate that we have advertised a 0
13376 * window. This may cause the remote transmitter to stall. This
13377 * flag tells soreceive() to disable delayed acknowledgements when
13378 * draining the buffer. This can occur if the receiver is
13379 * attempting to read more data than can be buffered prior to
13380 * transmitting on the connection.
13381 */
13382 if (th->th_win == 0) {
13383 tp->t_sndzerowin++;
13384 tp->t_flags |= TF_RXWIN0SENT;
13385 } else
13386 tp->t_flags &= ~TF_RXWIN0SENT;
13387 /*
13388 * We don't support urgent data, but drag along
13389 * the pointer in case of a stack switch.
13390 */
13391 tp->snd_up = tp->snd_una;
13392 /*
13393 * Put TCP length in extended header, and then checksum extended
13394 * header and data.
13395 */
13396 m->m_pkthdr.len = hdrlen + len; /* in6_cksum() need this */
13397
13398 #if defined(IPSEC_SUPPORT) || defined(TCP_SIGNATURE)
13399 if (to.to_flags & TOF_SIGNATURE) {
13400 /*
13401 * Calculate MD5 signature and put it into the place
13402 * determined before. NOTE: since TCP options buffer doesn't
13403 * point into mbuf's data, calculate offset and use it.
13404 */
13405 if (!TCPMD5_ENABLED() || TCPMD5_OUTPUT(m, th,
13406 (u_char *)(th + 1) + (to.to_signature - opt)) != 0) {
13407 /*
13408 * Do not send segment if the calculation of MD5
13409 * digest has failed.
13410 */
13411 goto out;
13412 }
13413 }
13414 #endif
13415
13416 #ifdef INET6
13417 if (isipv6) {
13418 /*
13419 * ip6_plen is not need to be filled now, and will be filled
13420 * in ip6_output.
13421 */
13422 if (tp->t_port) {
13423 m->m_pkthdr.csum_flags = CSUM_UDP_IPV6;
13424 m->m_pkthdr.csum_data = offsetof(struct udphdr, uh_sum);
13425 udp->uh_sum = in6_cksum_pseudo(ip6, ulen, IPPROTO_UDP, 0);
13426 th->th_sum = htons(0);
13427 UDPSTAT_INC(udps_opackets);
13428 } else {
13429 csum_flags = m->m_pkthdr.csum_flags = CSUM_TCP_IPV6;
13430 m->m_pkthdr.csum_data = offsetof(struct tcphdr, th_sum);
13431 th->th_sum = in6_cksum_pseudo(ip6, sizeof(struct tcphdr) +
13432 optlen + len, IPPROTO_TCP, 0);
13433 }
13434 }
13435 #endif
13436 #if defined(INET6) && defined(INET)
13437 else
13438 #endif
13439 #ifdef INET
13440 {
13441 if (tp->t_port) {
13442 m->m_pkthdr.csum_flags = CSUM_UDP;
13443 m->m_pkthdr.csum_data = offsetof(struct udphdr, uh_sum);
13444 udp->uh_sum = in_pseudo(ip->ip_src.s_addr,
13445 ip->ip_dst.s_addr, htons(ulen + IPPROTO_UDP));
13446 th->th_sum = htons(0);
13447 UDPSTAT_INC(udps_opackets);
13448 } else {
13449 csum_flags = m->m_pkthdr.csum_flags = CSUM_TCP;
13450 m->m_pkthdr.csum_data = offsetof(struct tcphdr, th_sum);
13451 th->th_sum = in_pseudo(ip->ip_src.s_addr,
13452 ip->ip_dst.s_addr, htons(sizeof(struct tcphdr) +
13453 IPPROTO_TCP + len + optlen));
13454 }
13455 /* IP version must be set here for ipv4/ipv6 checking later */
13456 KASSERT(ip->ip_v == IPVERSION,
13457 ("%s: IP version incorrect: %d", __func__, ip->ip_v));
13458 }
13459 #endif
13460
13461 /*
13462 * Enable TSO and specify the size of the segments. The TCP pseudo
13463 * header checksum is always provided. XXX: Fixme: This is currently
13464 * not the case for IPv6.
13465 */
13466 if (tso) {
13467 KASSERT(len > maxseg,
13468 ("%s: len:%d <= tso_segsz:%d", __func__, len, maxseg));
13469 m->m_pkthdr.csum_flags |= CSUM_TSO;
13470 csum_flags |= CSUM_TSO;
13471 m->m_pkthdr.tso_segsz = maxseg;
13472 }
13473 KASSERT(len + hdrlen == m_length(m, NULL),
13474 ("%s: mbuf chain different than expected: %d + %u != %u",
13475 __func__, len, hdrlen, m_length(m, NULL)));
13476
13477 #ifdef TCP_HHOOK
13478 /* Run HHOOK_TC_ESTABLISHED_OUT helper hooks. */
13479 hhook_run_tcp_est_out(tp, th, &to, len, tso);
13480 #endif
13481
13482 /* Log to the black box */
13483 if (tcp_bblogging_on(tp)) {
13484 union tcp_log_stackspecific log;
13485
13486 bbr_fill_in_logging_data(bbr, &log.u_bbr, cts);
13487 /* Record info on type of transmission */
13488 log.u_bbr.flex1 = bbr->r_ctl.rc_hptsi_agg_delay;
13489 log.u_bbr.flex2 = (bbr->r_recovery_bw << 3);
13490 log.u_bbr.flex3 = maxseg;
13491 log.u_bbr.flex4 = delay_calc;
13492 log.u_bbr.flex5 = bbr->rc_past_init_win;
13493 log.u_bbr.flex5 <<= 1;
13494 log.u_bbr.flex5 |= bbr->rc_no_pacing;
13495 log.u_bbr.flex5 <<= 29;
13496 log.u_bbr.flex5 |= tp->t_maxseg;
13497 log.u_bbr.flex6 = bbr->r_ctl.rc_pace_max_segs;
13498 log.u_bbr.flex7 = (bbr->rc_bbr_state << 8) | bbr_state_val(bbr);
13499 /* lets poke in the low and the high here for debugging */
13500 log.u_bbr.pkts_out = bbr->rc_tp->t_maxseg;
13501 if (rsm || sack_rxmit) {
13502 if (doing_tlp)
13503 log.u_bbr.flex8 = 2;
13504 else
13505 log.u_bbr.flex8 = 1;
13506 } else {
13507 log.u_bbr.flex8 = 0;
13508 }
13509 lgb = tcp_log_event(tp, th, &so->so_rcv, &so->so_snd, TCP_LOG_OUT, ERRNO_UNK,
13510 len, &log, false, NULL, NULL, 0, tv);
13511 } else {
13512 lgb = NULL;
13513 }
13514 /*
13515 * Fill in IP length and desired time to live and send to IP level.
13516 * There should be a better way to handle ttl and tos; we could keep
13517 * them in the template, but need a way to checksum without them.
13518 */
13519 /*
13520 * m->m_pkthdr.len should have been set before cksum calcuration,
13521 * because in6_cksum() need it.
13522 */
13523 #ifdef INET6
13524 if (isipv6) {
13525 /*
13526 * we separately set hoplimit for every segment, since the
13527 * user might want to change the value via setsockopt. Also,
13528 * desired default hop limit might be changed via Neighbor
13529 * Discovery.
13530 */
13531 ip6->ip6_hlim = in6_selecthlim(inp, NULL);
13532
13533 /*
13534 * Set the packet size here for the benefit of DTrace
13535 * probes. ip6_output() will set it properly; it's supposed
13536 * to include the option header lengths as well.
13537 */
13538 ip6->ip6_plen = htons(m->m_pkthdr.len - sizeof(*ip6));
13539
13540 if (V_path_mtu_discovery && maxseg > V_tcp_minmss)
13541 tp->t_flags2 |= TF2_PLPMTU_PMTUD;
13542 else
13543 tp->t_flags2 &= ~TF2_PLPMTU_PMTUD;
13544
13545 if (tp->t_state == TCPS_SYN_SENT)
13546 TCP_PROBE5(connect__request, NULL, tp, ip6, tp, th);
13547
13548 TCP_PROBE5(send, NULL, tp, ip6, tp, th);
13549 /* TODO: IPv6 IP6TOS_ECT bit on */
13550 error = ip6_output(m, inp->in6p_outputopts,
13551 &inp->inp_route6,
13552 ((rsm || sack_rxmit) ? IP_NO_SND_TAG_RL : 0),
13553 NULL, NULL, inp);
13554
13555 if (error == EMSGSIZE && inp->inp_route6.ro_nh != NULL)
13556 mtu = inp->inp_route6.ro_nh->nh_mtu;
13557 }
13558 #endif /* INET6 */
13559 #if defined(INET) && defined(INET6)
13560 else
13561 #endif
13562 #ifdef INET
13563 {
13564 ip->ip_len = htons(m->m_pkthdr.len);
13565 #ifdef INET6
13566 if (isipv6)
13567 ip->ip_ttl = in6_selecthlim(inp, NULL);
13568 #endif /* INET6 */
13569 /*
13570 * If we do path MTU discovery, then we set DF on every
13571 * packet. This might not be the best thing to do according
13572 * to RFC3390 Section 2. However the tcp hostcache migitates
13573 * the problem so it affects only the first tcp connection
13574 * with a host.
13575 *
13576 * NB: Don't set DF on small MTU/MSS to have a safe
13577 * fallback.
13578 */
13579 if (V_path_mtu_discovery && tp->t_maxseg > V_tcp_minmss) {
13580 tp->t_flags2 |= TF2_PLPMTU_PMTUD;
13581 if (tp->t_port == 0 || len < V_tcp_minmss) {
13582 ip->ip_off |= htons(IP_DF);
13583 }
13584 } else {
13585 tp->t_flags2 &= ~TF2_PLPMTU_PMTUD;
13586 }
13587
13588 if (tp->t_state == TCPS_SYN_SENT)
13589 TCP_PROBE5(connect__request, NULL, tp, ip, tp, th);
13590
13591 TCP_PROBE5(send, NULL, tp, ip, tp, th);
13592
13593 error = ip_output(m, inp->inp_options, &inp->inp_route,
13594 ((rsm || sack_rxmit) ? IP_NO_SND_TAG_RL : 0), 0,
13595 inp);
13596 if (error == EMSGSIZE && inp->inp_route.ro_nh != NULL)
13597 mtu = inp->inp_route.ro_nh->nh_mtu;
13598 }
13599 #endif /* INET */
13600 if (lgb) {
13601 lgb->tlb_errno = error;
13602 lgb = NULL;
13603 }
13604
13605 out:
13606 /*
13607 * In transmit state, time the transmission and arrange for the
13608 * retransmit. In persist state, just set snd_max.
13609 */
13610 if (error == 0) {
13611 tcp_account_for_send(tp, len, (rsm != NULL), doing_tlp, hw_tls);
13612 if (TCPS_HAVEESTABLISHED(tp->t_state) &&
13613 (tp->t_flags & TF_SACK_PERMIT) &&
13614 tp->rcv_numsacks > 0)
13615 tcp_clean_dsack_blocks(tp);
13616 /* We sent an ack clear the bbr_segs_rcvd count */
13617 bbr->output_error_seen = 0;
13618 bbr->oerror_cnt = 0;
13619 bbr->bbr_segs_rcvd = 0;
13620 if (len == 0)
13621 counter_u64_add(bbr_out_size[TCP_MSS_ACCT_SNDACK], 1);
13622 /* Do accounting for new sends */
13623 if ((len > 0) && (rsm == NULL)) {
13624 int idx;
13625 if (tp->snd_una == tp->snd_max) {
13626 /*
13627 * Special case to match google, when
13628 * nothing is in flight the delivered
13629 * time does get updated to the current
13630 * time (see tcp_rate_bsd.c).
13631 */
13632 bbr->r_ctl.rc_del_time = cts;
13633 }
13634 if (len >= maxseg) {
13635 idx = (len / maxseg) + 3;
13636 if (idx >= TCP_MSS_ACCT_ATIMER)
13637 counter_u64_add(bbr_out_size[(TCP_MSS_ACCT_ATIMER - 1)], 1);
13638 else
13639 counter_u64_add(bbr_out_size[idx], 1);
13640 } else {
13641 /* smaller than a MSS */
13642 idx = len / (bbr_hptsi_bytes_min - bbr->rc_last_options);
13643 if (idx >= TCP_MSS_SMALL_MAX_SIZE_DIV)
13644 idx = (TCP_MSS_SMALL_MAX_SIZE_DIV - 1);
13645 counter_u64_add(bbr_out_size[(idx + TCP_MSS_SMALL_SIZE_OFF)], 1);
13646 }
13647 }
13648 }
13649 abandon = 0;
13650 /*
13651 * We must do the send accounting before we log the output,
13652 * otherwise the state of the rsm could change and we account to the
13653 * wrong bucket.
13654 */
13655 if (len > 0) {
13656 bbr_do_send_accounting(tp, bbr, rsm, len, error);
13657 if (error == 0) {
13658 if (tp->snd_una == tp->snd_max)
13659 bbr->r_ctl.rc_tlp_rxt_last_time = cts;
13660 }
13661 }
13662 bbr_log_output(bbr, tp, &to, len, bbr_seq, (uint8_t) flags, error,
13663 cts, mb, &abandon, rsm, 0, sb);
13664 if (abandon) {
13665 /*
13666 * If bbr_log_output destroys the TCB or sees a TH_RST being
13667 * sent we should hit this condition.
13668 */
13669 return (0);
13670 }
13671 if (bbr->rc_in_persist == 0) {
13672 /*
13673 * Advance snd_nxt over sequence space of this segment.
13674 */
13675 if (error)
13676 /* We don't log or do anything with errors */
13677 goto skip_upd;
13678
13679 if (tp->snd_una == tp->snd_max &&
13680 (len || (flags & (TH_SYN | TH_FIN)))) {
13681 /*
13682 * Update the time we just added data since none was
13683 * outstanding.
13684 */
13685 bbr_log_progress_event(bbr, tp, ticks, PROGRESS_START, __LINE__);
13686 bbr->rc_tp->t_acktime = ticks;
13687 }
13688 if (flags & (TH_SYN | TH_FIN) && (rsm == NULL)) {
13689 if (flags & TH_SYN) {
13690 /*
13691 * Smack the snd_max to iss + 1
13692 * if its a FO we will add len below.
13693 */
13694 tp->snd_max = tp->iss + 1;
13695 }
13696 if ((flags & TH_FIN) && ((tp->t_flags & TF_SENTFIN) == 0)) {
13697 tp->snd_max++;
13698 tp->t_flags |= TF_SENTFIN;
13699 }
13700 }
13701 if (sack_rxmit == 0)
13702 tp->snd_max += len;
13703 skip_upd:
13704 if ((error == 0) && len)
13705 tot_len += len;
13706 } else {
13707 /* Persists case */
13708 int32_t xlen = len;
13709
13710 if (error)
13711 goto nomore;
13712
13713 if (flags & TH_SYN)
13714 ++xlen;
13715 if ((flags & TH_FIN) && ((tp->t_flags & TF_SENTFIN) == 0)) {
13716 ++xlen;
13717 tp->t_flags |= TF_SENTFIN;
13718 }
13719 if (xlen && (tp->snd_una == tp->snd_max)) {
13720 /*
13721 * Update the time we just added data since none was
13722 * outstanding.
13723 */
13724 bbr_log_progress_event(bbr, tp, ticks, PROGRESS_START, __LINE__);
13725 bbr->rc_tp->t_acktime = ticks;
13726 }
13727 if (sack_rxmit == 0)
13728 tp->snd_max += xlen;
13729 tot_len += (len + optlen + ipoptlen);
13730 }
13731 nomore:
13732 if (error) {
13733 /*
13734 * Failures do not advance the seq counter above. For the
13735 * case of ENOBUFS we will fall out and become ack-clocked.
13736 * capping the cwnd at the current flight.
13737 * Everything else will just have to retransmit with the timer
13738 * (no pacer).
13739 */
13740 SOCK_SENDBUF_UNLOCK_ASSERT(so);
13741 BBR_STAT_INC(bbr_saw_oerr);
13742 /* Clear all delay/early tracks */
13743 bbr->r_ctl.rc_hptsi_agg_delay = 0;
13744 bbr->r_ctl.rc_agg_early = 0;
13745 bbr->r_agg_early_set = 0;
13746 bbr->output_error_seen = 1;
13747 if (bbr->oerror_cnt < 0xf)
13748 bbr->oerror_cnt++;
13749 if (bbr_max_net_error_cnt && (bbr->oerror_cnt >= bbr_max_net_error_cnt)) {
13750 /* drop the session */
13751 return (-ENETDOWN);
13752 }
13753 switch (error) {
13754 case ENOBUFS:
13755 /*
13756 * Make this guy have to get ack's to send
13757 * more but lets make sure we don't
13758 * slam him below a T-O (1MSS).
13759 */
13760 if (bbr->rc_bbr_state != BBR_STATE_PROBE_RTT) {
13761 tp->snd_cwnd = ctf_flight_size(tp, (bbr->r_ctl.rc_sacked +
13762 bbr->r_ctl.rc_lost_bytes)) - maxseg;
13763 if (tp->snd_cwnd < maxseg)
13764 tp->snd_cwnd = maxseg;
13765 }
13766 slot = (bbr_error_base_paceout + 1) << bbr->oerror_cnt;
13767 BBR_STAT_INC(bbr_saw_enobuf);
13768 if (bbr->bbr_hdrw_pacing)
13769 counter_u64_add(bbr_hdwr_pacing_enobuf, 1);
13770 else
13771 counter_u64_add(bbr_nohdwr_pacing_enobuf, 1);
13772 /*
13773 * Here even in the enobuf's case we want to do our
13774 * state update. The reason being we may have been
13775 * called by the input function. If so we have had
13776 * things change.
13777 */
13778 error = 0;
13779 goto enobufs;
13780 case EMSGSIZE:
13781 /*
13782 * For some reason the interface we used initially
13783 * to send segments changed to another or lowered
13784 * its MTU. If TSO was active we either got an
13785 * interface without TSO capabilits or TSO was
13786 * turned off. If we obtained mtu from ip_output()
13787 * then update it and try again.
13788 */
13789 /* Turn on tracing (or try to) */
13790 {
13791 int old_maxseg;
13792
13793 old_maxseg = tp->t_maxseg;
13794 BBR_STAT_INC(bbr_saw_emsgsiz);
13795 bbr_log_msgsize_fail(bbr, tp, len, maxseg, mtu, csum_flags, tso, cts);
13796 if (mtu != 0)
13797 tcp_mss_update(tp, -1, mtu, NULL, NULL);
13798 if (old_maxseg <= tp->t_maxseg) {
13799 /* Huh it did not shrink? */
13800 tp->t_maxseg = old_maxseg - 40;
13801 if (tp->t_maxseg < V_tcp_mssdflt) {
13802 /*
13803 * The MSS is so small we should not
13804 * process incoming SACK's since we are
13805 * subject to attack in such a case.
13806 */
13807 tp->t_flags2 |= TF2_PROC_SACK_PROHIBIT;
13808 } else {
13809 tp->t_flags2 &= ~TF2_PROC_SACK_PROHIBIT;
13810 }
13811 bbr_log_msgsize_fail(bbr, tp, len, maxseg, mtu, 0, tso, cts);
13812 }
13813 /*
13814 * Nuke all other things that can interfere
13815 * with slot
13816 */
13817 if ((tot_len + len) && (len >= tp->t_maxseg)) {
13818 slot = bbr_get_pacing_delay(bbr,
13819 bbr->r_ctl.rc_bbr_hptsi_gain,
13820 (tot_len + len), cts, 0);
13821 if (slot < bbr_error_base_paceout)
13822 slot = (bbr_error_base_paceout + 2) << bbr->oerror_cnt;
13823 } else
13824 slot = (bbr_error_base_paceout + 2) << bbr->oerror_cnt;
13825 bbr->rc_output_starts_timer = 1;
13826 bbr_start_hpts_timer(bbr, tp, cts, 10, slot,
13827 tot_len);
13828 return (error);
13829 }
13830 case EPERM:
13831 case EACCES:
13832 tp->t_softerror = error;
13833 /* FALLTHROUGH */
13834 case EHOSTDOWN:
13835 case EHOSTUNREACH:
13836 case ENETDOWN:
13837 case ENETUNREACH:
13838 if (TCPS_HAVERCVDSYN(tp->t_state)) {
13839 tp->t_softerror = error;
13840 error = 0;
13841 }
13842 /* FALLTHROUGH */
13843 default:
13844 slot = (bbr_error_base_paceout + 3) << bbr->oerror_cnt;
13845 bbr->rc_output_starts_timer = 1;
13846 bbr_start_hpts_timer(bbr, tp, cts, 11, slot, 0);
13847 return (error);
13848 }
13849 #ifdef STATS
13850 } else if (((tp->t_flags & TF_GPUTINPROG) == 0) &&
13851 len &&
13852 (rsm == NULL) &&
13853 (bbr->rc_in_persist == 0)) {
13854 tp->gput_seq = bbr_seq;
13855 tp->gput_ack = bbr_seq +
13856 min(sbavail(&so->so_snd) - sb_offset, sendwin);
13857 tp->gput_ts = cts;
13858 tp->t_flags |= TF_GPUTINPROG;
13859 #endif
13860 }
13861 KMOD_TCPSTAT_INC(tcps_sndtotal);
13862 if ((bbr->bbr_hdw_pace_ena) &&
13863 (bbr->bbr_attempt_hdwr_pace == 0) &&
13864 (bbr->rc_past_init_win) &&
13865 (bbr->rc_bbr_state != BBR_STATE_STARTUP) &&
13866 (get_filter_value(&bbr->r_ctl.rc_delrate)) &&
13867 (inp->inp_route.ro_nh &&
13868 inp->inp_route.ro_nh->nh_ifp)) {
13869 /*
13870 * We are past the initial window and
13871 * have at least one measurement so we
13872 * could use hardware pacing if its available.
13873 * We have an interface and we have not attempted
13874 * to setup hardware pacing, lets try to now.
13875 */
13876 uint64_t rate_wanted;
13877 int err = 0;
13878
13879 rate_wanted = bbr_get_hardware_rate(bbr);
13880 bbr->bbr_attempt_hdwr_pace = 1;
13881 bbr->r_ctl.crte = tcp_set_pacing_rate(bbr->rc_tp,
13882 inp->inp_route.ro_nh->nh_ifp,
13883 rate_wanted,
13884 (RS_PACING_GEQ|RS_PACING_SUB_OK),
13885 &err, NULL);
13886 if (bbr->r_ctl.crte) {
13887 bbr_type_log_hdwr_pacing(bbr,
13888 bbr->r_ctl.crte->ptbl->rs_ifp,
13889 rate_wanted,
13890 bbr->r_ctl.crte->rate,
13891 __LINE__, cts, err);
13892 BBR_STAT_INC(bbr_hdwr_rl_add_ok);
13893 counter_u64_add(bbr_flows_nohdwr_pacing, -1);
13894 counter_u64_add(bbr_flows_whdwr_pacing, 1);
13895 bbr->bbr_hdrw_pacing = 1;
13896 /* Now what is our gain status? */
13897 if (bbr->r_ctl.crte->rate < rate_wanted) {
13898 /* We have a problem */
13899 bbr_setup_less_of_rate(bbr, cts,
13900 bbr->r_ctl.crte->rate, rate_wanted);
13901 } else {
13902 /* We are good */
13903 bbr->gain_is_limited = 0;
13904 bbr->skip_gain = 0;
13905 }
13906 tcp_bbr_tso_size_check(bbr, cts);
13907 } else {
13908 bbr_type_log_hdwr_pacing(bbr,
13909 inp->inp_route.ro_nh->nh_ifp,
13910 rate_wanted,
13911 0,
13912 __LINE__, cts, err);
13913 BBR_STAT_INC(bbr_hdwr_rl_add_fail);
13914 }
13915 }
13916 if (bbr->bbr_hdrw_pacing) {
13917 /*
13918 * Worry about cases where the route
13919 * changes or something happened that we
13920 * lost our hardware pacing possibly during
13921 * the last ip_output call.
13922 */
13923 if (inp->inp_snd_tag == NULL) {
13924 /* A change during ip output disabled hw pacing? */
13925 bbr->bbr_hdrw_pacing = 0;
13926 } else if ((inp->inp_route.ro_nh == NULL) ||
13927 (inp->inp_route.ro_nh->nh_ifp != inp->inp_snd_tag->ifp)) {
13928 /*
13929 * We had an interface or route change,
13930 * detach from the current hdwr pacing
13931 * and setup to re-attempt next go
13932 * round.
13933 */
13934 bbr->bbr_hdrw_pacing = 0;
13935 bbr->bbr_attempt_hdwr_pace = 0;
13936 tcp_rel_pacing_rate(bbr->r_ctl.crte, bbr->rc_tp);
13937 tcp_bbr_tso_size_check(bbr, cts);
13938 }
13939 }
13940 /*
13941 * Data sent (as far as we can tell). If this advertises a larger
13942 * window than any other segment, then remember the size of the
13943 * advertised window. Any pending ACK has now been sent.
13944 */
13945 if (SEQ_GT(tp->rcv_nxt + recwin, tp->rcv_adv))
13946 tp->rcv_adv = tp->rcv_nxt + recwin;
13947
13948 tp->last_ack_sent = tp->rcv_nxt;
13949 if ((error == 0) &&
13950 (bbr->r_ctl.rc_pace_max_segs > tp->t_maxseg) &&
13951 (doing_tlp == 0) &&
13952 (tso == 0) &&
13953 (len > 0) &&
13954 ((flags & TH_RST) == 0) &&
13955 ((flags & TH_SYN) == 0) &&
13956 (IN_RECOVERY(tp->t_flags) == 0) &&
13957 (bbr->rc_in_persist == 0) &&
13958 (tot_len < bbr->r_ctl.rc_pace_max_segs)) {
13959 /*
13960 * For non-tso we need to goto again until we have sent out
13961 * enough data to match what we are hptsi out every hptsi
13962 * interval.
13963 */
13964 if (SEQ_LT(tp->snd_nxt, tp->snd_max)) {
13965 /* Make sure snd_nxt is drug up */
13966 tp->snd_nxt = tp->snd_max;
13967 }
13968 if (rsm != NULL) {
13969 rsm = NULL;
13970 goto skip_again;
13971 }
13972 rsm = NULL;
13973 sack_rxmit = 0;
13974 tp->t_flags &= ~(TF_ACKNOW | TF_DELACK);
13975 goto again;
13976 }
13977 skip_again:
13978 if ((error == 0) && (flags & TH_FIN))
13979 tcp_log_end_status(tp, TCP_EI_STATUS_SERVER_FIN);
13980 if ((error == 0) && (flags & TH_RST))
13981 tcp_log_end_status(tp, TCP_EI_STATUS_SERVER_RST);
13982 if (((flags & (TH_RST | TH_SYN | TH_FIN)) == 0) && tot_len) {
13983 /*
13984 * Calculate/Re-Calculate the hptsi slot in usecs based on
13985 * what we have sent so far
13986 */
13987 slot = bbr_get_pacing_delay(bbr, bbr->r_ctl.rc_bbr_hptsi_gain, tot_len, cts, 0);
13988 if (bbr->rc_no_pacing)
13989 slot = 0;
13990 }
13991 tp->t_flags &= ~(TF_ACKNOW | TF_DELACK);
13992 enobufs:
13993 if (bbr->rc_use_google == 0)
13994 bbr_check_bbr_for_state(bbr, cts, __LINE__, 0);
13995 bbr_cwnd_limiting(tp, bbr, ctf_flight_size(tp, (bbr->r_ctl.rc_sacked +
13996 bbr->r_ctl.rc_lost_bytes)));
13997 bbr->rc_output_starts_timer = 1;
13998 if (bbr->bbr_use_rack_cheat &&
13999 (more_to_rxt ||
14000 ((bbr->r_ctl.rc_resend = bbr_check_recovery_mode(tp, bbr, cts)) != NULL))) {
14001 /* Rack cheats and shotguns out all rxt's 1ms apart */
14002 if (slot > 1000)
14003 slot = 1000;
14004 }
14005 if (bbr->bbr_hdrw_pacing && (bbr->hw_pacing_set == 0)) {
14006 /*
14007 * We don't change the tso size until some number of sends
14008 * to give the hardware commands time to get down
14009 * to the interface.
14010 */
14011 bbr->r_ctl.bbr_hdwr_cnt_noset_snt++;
14012 if (bbr->r_ctl.bbr_hdwr_cnt_noset_snt >= bbr_hdwr_pacing_delay_cnt) {
14013 bbr->hw_pacing_set = 1;
14014 tcp_bbr_tso_size_check(bbr, cts);
14015 }
14016 }
14017 bbr_start_hpts_timer(bbr, tp, cts, 12, slot, tot_len);
14018 if (SEQ_LT(tp->snd_nxt, tp->snd_max)) {
14019 /* Make sure snd_nxt is drug up */
14020 tp->snd_nxt = tp->snd_max;
14021 }
14022 return (error);
14023
14024 }
14025
14026 /*
14027 * See bbr_output_wtime() for return values.
14028 */
14029 static int
bbr_output(struct tcpcb * tp)14030 bbr_output(struct tcpcb *tp)
14031 {
14032 int32_t ret;
14033 struct timeval tv;
14034
14035 NET_EPOCH_ASSERT();
14036
14037 INP_WLOCK_ASSERT(tptoinpcb(tp));
14038 (void)tcp_get_usecs(&tv);
14039 ret = bbr_output_wtime(tp, &tv);
14040 return (ret);
14041 }
14042
14043 static void
bbr_mtu_chg(struct tcpcb * tp)14044 bbr_mtu_chg(struct tcpcb *tp)
14045 {
14046 struct tcp_bbr *bbr;
14047 struct bbr_sendmap *rsm, *frsm = NULL;
14048 uint32_t maxseg;
14049
14050 /*
14051 * The MTU has changed. a) Clear the sack filter. b) Mark everything
14052 * over the current size as SACK_PASS so a retransmit will occur.
14053 */
14054
14055 bbr = (struct tcp_bbr *)tp->t_fb_ptr;
14056 maxseg = tp->t_maxseg - bbr->rc_last_options;
14057 sack_filter_clear(&bbr->r_ctl.bbr_sf, tp->snd_una);
14058 TAILQ_FOREACH(rsm, &bbr->r_ctl.rc_map, r_next) {
14059 /* Don't mess with ones acked (by sack?) */
14060 if (rsm->r_flags & BBR_ACKED)
14061 continue;
14062 if ((rsm->r_end - rsm->r_start) > maxseg) {
14063 /*
14064 * We mark sack-passed on all the previous large
14065 * sends we did. This will force them to retransmit.
14066 */
14067 rsm->r_flags |= BBR_SACK_PASSED;
14068 if (((rsm->r_flags & BBR_MARKED_LOST) == 0) &&
14069 bbr_is_lost(bbr, rsm, bbr->r_ctl.rc_rcvtime)) {
14070 bbr->r_ctl.rc_lost_bytes += rsm->r_end - rsm->r_start;
14071 bbr->r_ctl.rc_lost += rsm->r_end - rsm->r_start;
14072 rsm->r_flags |= BBR_MARKED_LOST;
14073 }
14074 if (frsm == NULL)
14075 frsm = rsm;
14076 }
14077 }
14078 if (frsm) {
14079 bbr->r_ctl.rc_resend = frsm;
14080 }
14081 }
14082
14083 static int
bbr_pru_options(struct tcpcb * tp,int flags)14084 bbr_pru_options(struct tcpcb *tp, int flags)
14085 {
14086 if (flags & PRUS_OOB)
14087 return (EOPNOTSUPP);
14088 return (0);
14089 }
14090
14091 static void
bbr_switch_failed(struct tcpcb * tp)14092 bbr_switch_failed(struct tcpcb *tp)
14093 {
14094 /*
14095 * If a switch fails we only need to
14096 * make sure mbuf_queuing is still in place.
14097 * We also need to make sure we are still in
14098 * ticks granularity (though we should probably
14099 * change bbr to go to USECs).
14100 *
14101 * For timers we need to see if we are still in the
14102 * pacer (if our flags are up) if so we are good, if
14103 * not we need to get back into the pacer.
14104 */
14105 struct timeval tv;
14106 uint32_t cts;
14107 uint32_t toval;
14108 struct tcp_bbr *bbr;
14109 struct hpts_diag diag;
14110
14111 tp->t_flags2 |= TF2_CANNOT_DO_ECN;
14112 tp->t_flags2 |= TF2_SUPPORTS_MBUFQ;
14113 tcp_change_time_units(tp, TCP_TMR_GRANULARITY_TICKS);
14114 if (tp->t_in_hpts > IHPTS_NONE) {
14115 return;
14116 }
14117 bbr = (struct tcp_bbr *)tp->t_fb_ptr;
14118 cts = tcp_get_usecs(&tv);
14119 if (bbr->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT) {
14120 if (TSTMP_GT(bbr->rc_pacer_started, cts)) {
14121 toval = bbr->rc_pacer_started - cts;
14122 } else {
14123 /* one slot please */
14124 toval = HPTS_USECS_PER_SLOT;
14125 }
14126 } else if (bbr->r_ctl.rc_hpts_flags & PACE_TMR_MASK) {
14127 if (TSTMP_GT(bbr->r_ctl.rc_timer_exp, cts)) {
14128 toval = bbr->r_ctl.rc_timer_exp - cts;
14129 } else {
14130 /* one slot please */
14131 toval = HPTS_USECS_PER_SLOT;
14132 }
14133 } else
14134 toval = HPTS_USECS_PER_SLOT;
14135 (void)tcp_hpts_insert_diag(tp, HPTS_USEC_TO_SLOTS(toval),
14136 __LINE__, &diag);
14137 bbr_log_hpts_diag(bbr, cts, &diag);
14138 }
14139
14140 struct tcp_function_block __tcp_bbr = {
14141 .tfb_tcp_block_name = __XSTRING(STACKNAME),
14142 .tfb_tcp_output = bbr_output,
14143 .tfb_do_queued_segments = ctf_do_queued_segments,
14144 .tfb_do_segment_nounlock = bbr_do_segment_nounlock,
14145 .tfb_tcp_do_segment = bbr_do_segment,
14146 .tfb_tcp_ctloutput = bbr_ctloutput,
14147 .tfb_tcp_fb_init = bbr_init,
14148 .tfb_tcp_fb_fini = bbr_fini,
14149 .tfb_tcp_timer_stop_all = bbr_stopall,
14150 .tfb_tcp_rexmit_tmr = bbr_remxt_tmr,
14151 .tfb_tcp_handoff_ok = bbr_handoff_ok,
14152 .tfb_tcp_mtu_chg = bbr_mtu_chg,
14153 .tfb_pru_options = bbr_pru_options,
14154 .tfb_switch_failed = bbr_switch_failed,
14155 .tfb_flags = TCP_FUNC_OUTPUT_CANDROP | TCP_FUNC_DEFAULT_OK,
14156 };
14157
14158 /*
14159 * bbr_ctloutput() must drop the inpcb lock before performing copyin on
14160 * socket option arguments. When it re-acquires the lock after the copy, it
14161 * has to revalidate that the connection is still valid for the socket
14162 * option.
14163 */
14164 static int
bbr_set_sockopt(struct tcpcb * tp,struct sockopt * sopt)14165 bbr_set_sockopt(struct tcpcb *tp, struct sockopt *sopt)
14166 {
14167 struct epoch_tracker et;
14168 struct inpcb *inp = tptoinpcb(tp);
14169 struct tcp_bbr *bbr;
14170 int32_t error = 0, optval;
14171
14172 switch (sopt->sopt_level) {
14173 case IPPROTO_IPV6:
14174 case IPPROTO_IP:
14175 return (tcp_default_ctloutput(tp, sopt));
14176 }
14177
14178 switch (sopt->sopt_name) {
14179 case TCP_RACK_PACE_MAX_SEG:
14180 case TCP_RACK_MIN_TO:
14181 case TCP_RACK_REORD_THRESH:
14182 case TCP_RACK_REORD_FADE:
14183 case TCP_RACK_TLP_THRESH:
14184 case TCP_RACK_PKT_DELAY:
14185 case TCP_BBR_ALGORITHM:
14186 case TCP_BBR_TSLIMITS:
14187 case TCP_BBR_IWINTSO:
14188 case TCP_BBR_STARTUP_PG:
14189 case TCP_BBR_DRAIN_PG:
14190 case TCP_BBR_PROBE_RTT_INT:
14191 case TCP_BBR_PROBE_RTT_GAIN:
14192 case TCP_BBR_PROBE_RTT_LEN:
14193 case TCP_BBR_STARTUP_LOSS_EXIT:
14194 case TCP_BBR_USEDEL_RATE:
14195 case TCP_BBR_MIN_RTO:
14196 case TCP_BBR_MAX_RTO:
14197 case TCP_BBR_PACE_PER_SEC:
14198 case TCP_DELACK:
14199 case TCP_BBR_PACE_DEL_TAR:
14200 case TCP_BBR_SEND_IWND_IN_TSO:
14201 case TCP_BBR_EXTRA_STATE:
14202 case TCP_BBR_UTTER_MAX_TSO:
14203 case TCP_BBR_MIN_TOPACEOUT:
14204 case TCP_BBR_FLOOR_MIN_TSO:
14205 case TCP_BBR_TSTMP_RAISES:
14206 case TCP_BBR_POLICER_DETECT:
14207 case TCP_BBR_USE_RACK_CHEAT:
14208 case TCP_DATA_AFTER_CLOSE:
14209 case TCP_BBR_HDWR_PACE:
14210 case TCP_BBR_PACE_SEG_MAX:
14211 case TCP_BBR_PACE_SEG_MIN:
14212 case TCP_BBR_PACE_CROSS:
14213 case TCP_BBR_PACE_OH:
14214 case TCP_BBR_TMR_PACE_OH:
14215 case TCP_BBR_RACK_RTT_USE:
14216 case TCP_BBR_RETRAN_WTSO:
14217 break;
14218 default:
14219 return (tcp_default_ctloutput(tp, sopt));
14220 break;
14221 }
14222 INP_WUNLOCK(inp);
14223 error = sooptcopyin(sopt, &optval, sizeof(optval), sizeof(optval));
14224 if (error)
14225 return (error);
14226 INP_WLOCK(inp);
14227 if (inp->inp_flags & INP_DROPPED) {
14228 INP_WUNLOCK(inp);
14229 return (ECONNRESET);
14230 }
14231 if (tp->t_fb != &__tcp_bbr) {
14232 INP_WUNLOCK(inp);
14233 return (ENOPROTOOPT);
14234 }
14235 bbr = (struct tcp_bbr *)tp->t_fb_ptr;
14236 switch (sopt->sopt_name) {
14237 case TCP_BBR_PACE_PER_SEC:
14238 BBR_OPTS_INC(tcp_bbr_pace_per_sec);
14239 bbr->r_ctl.bbr_hptsi_per_second = optval;
14240 break;
14241 case TCP_BBR_PACE_DEL_TAR:
14242 BBR_OPTS_INC(tcp_bbr_pace_del_tar);
14243 bbr->r_ctl.bbr_hptsi_segments_delay_tar = optval;
14244 break;
14245 case TCP_BBR_PACE_SEG_MAX:
14246 BBR_OPTS_INC(tcp_bbr_pace_seg_max);
14247 bbr->r_ctl.bbr_hptsi_segments_max = optval;
14248 break;
14249 case TCP_BBR_PACE_SEG_MIN:
14250 BBR_OPTS_INC(tcp_bbr_pace_seg_min);
14251 bbr->r_ctl.bbr_hptsi_bytes_min = optval;
14252 break;
14253 case TCP_BBR_PACE_CROSS:
14254 BBR_OPTS_INC(tcp_bbr_pace_cross);
14255 bbr->r_ctl.bbr_cross_over = optval;
14256 break;
14257 case TCP_BBR_ALGORITHM:
14258 BBR_OPTS_INC(tcp_bbr_algorithm);
14259 if (optval && (bbr->rc_use_google == 0)) {
14260 /* Turn on the google mode */
14261 bbr_google_mode_on(bbr);
14262 if ((optval > 3) && (optval < 500)) {
14263 /*
14264 * Must be at least greater than .3%
14265 * and must be less than 50.0%.
14266 */
14267 bbr->r_ctl.bbr_google_discount = optval;
14268 }
14269 } else if ((optval == 0) && (bbr->rc_use_google == 1)) {
14270 /* Turn off the google mode */
14271 bbr_google_mode_off(bbr);
14272 }
14273 break;
14274 case TCP_BBR_TSLIMITS:
14275 BBR_OPTS_INC(tcp_bbr_tslimits);
14276 if (optval == 1)
14277 bbr->rc_use_ts_limit = 1;
14278 else if (optval == 0)
14279 bbr->rc_use_ts_limit = 0;
14280 else
14281 error = EINVAL;
14282 break;
14283
14284 case TCP_BBR_IWINTSO:
14285 BBR_OPTS_INC(tcp_bbr_iwintso);
14286 if ((optval >= 0) && (optval < 128)) {
14287 uint32_t twin;
14288
14289 bbr->rc_init_win = optval;
14290 twin = bbr_initial_cwnd(bbr, tp);
14291 if ((bbr->rc_past_init_win == 0) && (twin > tp->snd_cwnd))
14292 tp->snd_cwnd = twin;
14293 else
14294 error = EBUSY;
14295 } else
14296 error = EINVAL;
14297 break;
14298 case TCP_BBR_STARTUP_PG:
14299 BBR_OPTS_INC(tcp_bbr_startup_pg);
14300 if ((optval > 0) && (optval < BBR_MAX_GAIN_VALUE)) {
14301 bbr->r_ctl.rc_startup_pg = optval;
14302 if (bbr->rc_bbr_state == BBR_STATE_STARTUP) {
14303 bbr->r_ctl.rc_bbr_hptsi_gain = optval;
14304 }
14305 } else
14306 error = EINVAL;
14307 break;
14308 case TCP_BBR_DRAIN_PG:
14309 BBR_OPTS_INC(tcp_bbr_drain_pg);
14310 if ((optval > 0) && (optval < BBR_MAX_GAIN_VALUE))
14311 bbr->r_ctl.rc_drain_pg = optval;
14312 else
14313 error = EINVAL;
14314 break;
14315 case TCP_BBR_PROBE_RTT_LEN:
14316 BBR_OPTS_INC(tcp_bbr_probertt_len);
14317 if (optval <= 1)
14318 reset_time_small(&bbr->r_ctl.rc_rttprop, (optval * USECS_IN_SECOND));
14319 else
14320 error = EINVAL;
14321 break;
14322 case TCP_BBR_PROBE_RTT_GAIN:
14323 BBR_OPTS_INC(tcp_bbr_probertt_gain);
14324 if (optval <= BBR_UNIT)
14325 bbr->r_ctl.bbr_rttprobe_gain_val = optval;
14326 else
14327 error = EINVAL;
14328 break;
14329 case TCP_BBR_PROBE_RTT_INT:
14330 BBR_OPTS_INC(tcp_bbr_probe_rtt_int);
14331 if (optval > 1000)
14332 bbr->r_ctl.rc_probertt_int = optval;
14333 else
14334 error = EINVAL;
14335 break;
14336 case TCP_BBR_MIN_TOPACEOUT:
14337 BBR_OPTS_INC(tcp_bbr_topaceout);
14338 if (optval == 0) {
14339 bbr->no_pacing_until = 0;
14340 bbr->rc_no_pacing = 0;
14341 } else if (optval <= 0x00ff) {
14342 bbr->no_pacing_until = optval;
14343 if ((bbr->r_ctl.rc_pkt_epoch < bbr->no_pacing_until) &&
14344 (bbr->rc_bbr_state == BBR_STATE_STARTUP)){
14345 /* Turn on no pacing */
14346 bbr->rc_no_pacing = 1;
14347 }
14348 } else
14349 error = EINVAL;
14350 break;
14351 case TCP_BBR_STARTUP_LOSS_EXIT:
14352 BBR_OPTS_INC(tcp_bbr_startup_loss_exit);
14353 bbr->rc_loss_exit = optval;
14354 break;
14355 case TCP_BBR_USEDEL_RATE:
14356 error = EINVAL;
14357 break;
14358 case TCP_BBR_MIN_RTO:
14359 BBR_OPTS_INC(tcp_bbr_min_rto);
14360 bbr->r_ctl.rc_min_rto_ms = optval;
14361 break;
14362 case TCP_BBR_MAX_RTO:
14363 BBR_OPTS_INC(tcp_bbr_max_rto);
14364 bbr->rc_max_rto_sec = optval;
14365 break;
14366 case TCP_RACK_MIN_TO:
14367 /* Minimum time between rack t-o's in ms */
14368 BBR_OPTS_INC(tcp_rack_min_to);
14369 bbr->r_ctl.rc_min_to = optval;
14370 break;
14371 case TCP_RACK_REORD_THRESH:
14372 /* RACK reorder threshold (shift amount) */
14373 BBR_OPTS_INC(tcp_rack_reord_thresh);
14374 if ((optval > 0) && (optval < 31))
14375 bbr->r_ctl.rc_reorder_shift = optval;
14376 else
14377 error = EINVAL;
14378 break;
14379 case TCP_RACK_REORD_FADE:
14380 /* Does reordering fade after ms time */
14381 BBR_OPTS_INC(tcp_rack_reord_fade);
14382 bbr->r_ctl.rc_reorder_fade = optval;
14383 break;
14384 case TCP_RACK_TLP_THRESH:
14385 /* RACK TLP theshold i.e. srtt+(srtt/N) */
14386 BBR_OPTS_INC(tcp_rack_tlp_thresh);
14387 if (optval)
14388 bbr->rc_tlp_threshold = optval;
14389 else
14390 error = EINVAL;
14391 break;
14392 case TCP_BBR_USE_RACK_CHEAT:
14393 BBR_OPTS_INC(tcp_use_rackcheat);
14394 if (bbr->rc_use_google) {
14395 error = EINVAL;
14396 break;
14397 }
14398 BBR_OPTS_INC(tcp_rack_cheat);
14399 if (optval)
14400 bbr->bbr_use_rack_cheat = 1;
14401 else
14402 bbr->bbr_use_rack_cheat = 0;
14403 break;
14404 case TCP_BBR_FLOOR_MIN_TSO:
14405 BBR_OPTS_INC(tcp_utter_max_tso);
14406 if ((optval >= 0) && (optval < 40))
14407 bbr->r_ctl.bbr_hptsi_segments_floor = optval;
14408 else
14409 error = EINVAL;
14410 break;
14411 case TCP_BBR_UTTER_MAX_TSO:
14412 BBR_OPTS_INC(tcp_utter_max_tso);
14413 if ((optval >= 0) && (optval < 0xffff))
14414 bbr->r_ctl.bbr_utter_max = optval;
14415 else
14416 error = EINVAL;
14417 break;
14418
14419 case TCP_BBR_EXTRA_STATE:
14420 BBR_OPTS_INC(tcp_extra_state);
14421 if (optval)
14422 bbr->rc_use_idle_restart = 1;
14423 else
14424 bbr->rc_use_idle_restart = 0;
14425 break;
14426 case TCP_BBR_SEND_IWND_IN_TSO:
14427 BBR_OPTS_INC(tcp_iwnd_tso);
14428 if (optval) {
14429 bbr->bbr_init_win_cheat = 1;
14430 if (bbr->rc_past_init_win == 0) {
14431 uint32_t cts;
14432 cts = tcp_get_usecs(&bbr->rc_tv);
14433 tcp_bbr_tso_size_check(bbr, cts);
14434 }
14435 } else
14436 bbr->bbr_init_win_cheat = 0;
14437 break;
14438 case TCP_BBR_HDWR_PACE:
14439 BBR_OPTS_INC(tcp_hdwr_pacing);
14440 if (optval){
14441 bbr->bbr_hdw_pace_ena = 1;
14442 bbr->bbr_attempt_hdwr_pace = 0;
14443 } else {
14444 bbr->bbr_hdw_pace_ena = 0;
14445 #ifdef RATELIMIT
14446 if (bbr->r_ctl.crte != NULL) {
14447 tcp_rel_pacing_rate(bbr->r_ctl.crte, tp);
14448 bbr->r_ctl.crte = NULL;
14449 }
14450 #endif
14451 }
14452 break;
14453
14454 case TCP_DELACK:
14455 BBR_OPTS_INC(tcp_delack);
14456 if (optval < 100) {
14457 if (optval == 0) /* off */
14458 tp->t_delayed_ack = 0;
14459 else if (optval == 1) /* on which is 2 */
14460 tp->t_delayed_ack = 2;
14461 else /* higher than 2 and less than 100 */
14462 tp->t_delayed_ack = optval;
14463 if (tp->t_flags & TF_DELACK) {
14464 tp->t_flags &= ~TF_DELACK;
14465 tp->t_flags |= TF_ACKNOW;
14466 NET_EPOCH_ENTER(et);
14467 bbr_output(tp);
14468 NET_EPOCH_EXIT(et);
14469 }
14470 } else
14471 error = EINVAL;
14472 break;
14473 case TCP_RACK_PKT_DELAY:
14474 /* RACK added ms i.e. rack-rtt + reord + N */
14475 BBR_OPTS_INC(tcp_rack_pkt_delay);
14476 bbr->r_ctl.rc_pkt_delay = optval;
14477 break;
14478
14479 case TCP_BBR_RETRAN_WTSO:
14480 BBR_OPTS_INC(tcp_retran_wtso);
14481 if (optval)
14482 bbr->rc_resends_use_tso = 1;
14483 else
14484 bbr->rc_resends_use_tso = 0;
14485 break;
14486 case TCP_DATA_AFTER_CLOSE:
14487 BBR_OPTS_INC(tcp_data_ac);
14488 if (optval)
14489 bbr->rc_allow_data_af_clo = 1;
14490 else
14491 bbr->rc_allow_data_af_clo = 0;
14492 break;
14493 case TCP_BBR_POLICER_DETECT:
14494 BBR_OPTS_INC(tcp_policer_det);
14495 if (bbr->rc_use_google == 0)
14496 error = EINVAL;
14497 else if (optval)
14498 bbr->r_use_policer = 1;
14499 else
14500 bbr->r_use_policer = 0;
14501 break;
14502
14503 case TCP_BBR_TSTMP_RAISES:
14504 BBR_OPTS_INC(tcp_ts_raises);
14505 if (optval)
14506 bbr->ts_can_raise = 1;
14507 else
14508 bbr->ts_can_raise = 0;
14509 break;
14510 case TCP_BBR_TMR_PACE_OH:
14511 BBR_OPTS_INC(tcp_pacing_oh_tmr);
14512 if (bbr->rc_use_google) {
14513 error = EINVAL;
14514 } else {
14515 if (optval)
14516 bbr->r_ctl.rc_incr_tmrs = 1;
14517 else
14518 bbr->r_ctl.rc_incr_tmrs = 0;
14519 }
14520 break;
14521 case TCP_BBR_PACE_OH:
14522 BBR_OPTS_INC(tcp_pacing_oh);
14523 if (bbr->rc_use_google) {
14524 error = EINVAL;
14525 } else {
14526 if (optval > (BBR_INCL_TCP_OH|
14527 BBR_INCL_IP_OH|
14528 BBR_INCL_ENET_OH)) {
14529 error = EINVAL;
14530 break;
14531 }
14532 if (optval & BBR_INCL_TCP_OH)
14533 bbr->r_ctl.rc_inc_tcp_oh = 1;
14534 else
14535 bbr->r_ctl.rc_inc_tcp_oh = 0;
14536 if (optval & BBR_INCL_IP_OH)
14537 bbr->r_ctl.rc_inc_ip_oh = 1;
14538 else
14539 bbr->r_ctl.rc_inc_ip_oh = 0;
14540 if (optval & BBR_INCL_ENET_OH)
14541 bbr->r_ctl.rc_inc_enet_oh = 1;
14542 else
14543 bbr->r_ctl.rc_inc_enet_oh = 0;
14544 }
14545 break;
14546 default:
14547 return (tcp_default_ctloutput(tp, sopt));
14548 break;
14549 }
14550 tcp_log_socket_option(tp, sopt->sopt_name, optval, error);
14551 INP_WUNLOCK(inp);
14552 return (error);
14553 }
14554
14555 /*
14556 * return 0 on success, error-num on failure
14557 */
14558 static int
bbr_get_sockopt(struct tcpcb * tp,struct sockopt * sopt)14559 bbr_get_sockopt(struct tcpcb *tp, struct sockopt *sopt)
14560 {
14561 struct inpcb *inp = tptoinpcb(tp);
14562 struct tcp_bbr *bbr;
14563 uint64_t loptval;
14564 int32_t error, optval;
14565
14566 bbr = (struct tcp_bbr *)tp->t_fb_ptr;
14567 if (bbr == NULL) {
14568 INP_WUNLOCK(inp);
14569 return (EINVAL);
14570 }
14571 /*
14572 * Because all our options are either boolean or an int, we can just
14573 * pull everything into optval and then unlock and copy. If we ever
14574 * add a option that is not a int, then this will have quite an
14575 * impact to this routine.
14576 */
14577 switch (sopt->sopt_name) {
14578 case TCP_BBR_PACE_PER_SEC:
14579 optval = bbr->r_ctl.bbr_hptsi_per_second;
14580 break;
14581 case TCP_BBR_PACE_DEL_TAR:
14582 optval = bbr->r_ctl.bbr_hptsi_segments_delay_tar;
14583 break;
14584 case TCP_BBR_PACE_SEG_MAX:
14585 optval = bbr->r_ctl.bbr_hptsi_segments_max;
14586 break;
14587 case TCP_BBR_MIN_TOPACEOUT:
14588 optval = bbr->no_pacing_until;
14589 break;
14590 case TCP_BBR_PACE_SEG_MIN:
14591 optval = bbr->r_ctl.bbr_hptsi_bytes_min;
14592 break;
14593 case TCP_BBR_PACE_CROSS:
14594 optval = bbr->r_ctl.bbr_cross_over;
14595 break;
14596 case TCP_BBR_ALGORITHM:
14597 optval = bbr->rc_use_google;
14598 break;
14599 case TCP_BBR_TSLIMITS:
14600 optval = bbr->rc_use_ts_limit;
14601 break;
14602 case TCP_BBR_IWINTSO:
14603 optval = bbr->rc_init_win;
14604 break;
14605 case TCP_BBR_STARTUP_PG:
14606 optval = bbr->r_ctl.rc_startup_pg;
14607 break;
14608 case TCP_BBR_DRAIN_PG:
14609 optval = bbr->r_ctl.rc_drain_pg;
14610 break;
14611 case TCP_BBR_PROBE_RTT_INT:
14612 optval = bbr->r_ctl.rc_probertt_int;
14613 break;
14614 case TCP_BBR_PROBE_RTT_LEN:
14615 optval = (bbr->r_ctl.rc_rttprop.cur_time_limit / USECS_IN_SECOND);
14616 break;
14617 case TCP_BBR_PROBE_RTT_GAIN:
14618 optval = bbr->r_ctl.bbr_rttprobe_gain_val;
14619 break;
14620 case TCP_BBR_STARTUP_LOSS_EXIT:
14621 optval = bbr->rc_loss_exit;
14622 break;
14623 case TCP_BBR_USEDEL_RATE:
14624 loptval = get_filter_value(&bbr->r_ctl.rc_delrate);
14625 break;
14626 case TCP_BBR_MIN_RTO:
14627 optval = bbr->r_ctl.rc_min_rto_ms;
14628 break;
14629 case TCP_BBR_MAX_RTO:
14630 optval = bbr->rc_max_rto_sec;
14631 break;
14632 case TCP_RACK_PACE_MAX_SEG:
14633 /* Max segments in a pace */
14634 optval = bbr->r_ctl.rc_pace_max_segs;
14635 break;
14636 case TCP_RACK_MIN_TO:
14637 /* Minimum time between rack t-o's in ms */
14638 optval = bbr->r_ctl.rc_min_to;
14639 break;
14640 case TCP_RACK_REORD_THRESH:
14641 /* RACK reorder threshold (shift amount) */
14642 optval = bbr->r_ctl.rc_reorder_shift;
14643 break;
14644 case TCP_RACK_REORD_FADE:
14645 /* Does reordering fade after ms time */
14646 optval = bbr->r_ctl.rc_reorder_fade;
14647 break;
14648 case TCP_BBR_USE_RACK_CHEAT:
14649 /* Do we use the rack cheat for rxt */
14650 optval = bbr->bbr_use_rack_cheat;
14651 break;
14652 case TCP_BBR_FLOOR_MIN_TSO:
14653 optval = bbr->r_ctl.bbr_hptsi_segments_floor;
14654 break;
14655 case TCP_BBR_UTTER_MAX_TSO:
14656 optval = bbr->r_ctl.bbr_utter_max;
14657 break;
14658 case TCP_BBR_SEND_IWND_IN_TSO:
14659 /* Do we send TSO size segments initially */
14660 optval = bbr->bbr_init_win_cheat;
14661 break;
14662 case TCP_BBR_EXTRA_STATE:
14663 optval = bbr->rc_use_idle_restart;
14664 break;
14665 case TCP_RACK_TLP_THRESH:
14666 /* RACK TLP theshold i.e. srtt+(srtt/N) */
14667 optval = bbr->rc_tlp_threshold;
14668 break;
14669 case TCP_RACK_PKT_DELAY:
14670 /* RACK added ms i.e. rack-rtt + reord + N */
14671 optval = bbr->r_ctl.rc_pkt_delay;
14672 break;
14673 case TCP_BBR_RETRAN_WTSO:
14674 optval = bbr->rc_resends_use_tso;
14675 break;
14676 case TCP_DATA_AFTER_CLOSE:
14677 optval = bbr->rc_allow_data_af_clo;
14678 break;
14679 case TCP_DELACK:
14680 optval = tp->t_delayed_ack;
14681 break;
14682 case TCP_BBR_HDWR_PACE:
14683 optval = bbr->bbr_hdw_pace_ena;
14684 break;
14685 case TCP_BBR_POLICER_DETECT:
14686 optval = bbr->r_use_policer;
14687 break;
14688 case TCP_BBR_TSTMP_RAISES:
14689 optval = bbr->ts_can_raise;
14690 break;
14691 case TCP_BBR_TMR_PACE_OH:
14692 optval = bbr->r_ctl.rc_incr_tmrs;
14693 break;
14694 case TCP_BBR_PACE_OH:
14695 optval = 0;
14696 if (bbr->r_ctl.rc_inc_tcp_oh)
14697 optval |= BBR_INCL_TCP_OH;
14698 if (bbr->r_ctl.rc_inc_ip_oh)
14699 optval |= BBR_INCL_IP_OH;
14700 if (bbr->r_ctl.rc_inc_enet_oh)
14701 optval |= BBR_INCL_ENET_OH;
14702 break;
14703 default:
14704 return (tcp_default_ctloutput(tp, sopt));
14705 break;
14706 }
14707 INP_WUNLOCK(inp);
14708 if (sopt->sopt_name == TCP_BBR_USEDEL_RATE)
14709 error = sooptcopyout(sopt, &loptval, sizeof loptval);
14710 else
14711 error = sooptcopyout(sopt, &optval, sizeof optval);
14712 return (error);
14713 }
14714
14715 /*
14716 * return 0 on success, error-num on failure
14717 */
14718 static int
bbr_ctloutput(struct tcpcb * tp,struct sockopt * sopt)14719 bbr_ctloutput(struct tcpcb *tp, struct sockopt *sopt)
14720 {
14721 if (sopt->sopt_dir == SOPT_SET) {
14722 return (bbr_set_sockopt(tp, sopt));
14723 } else if (sopt->sopt_dir == SOPT_GET) {
14724 return (bbr_get_sockopt(tp, sopt));
14725 } else {
14726 panic("%s: sopt_dir $%d", __func__, sopt->sopt_dir);
14727 }
14728 }
14729
14730 static const char *bbr_stack_names[] = {
14731 __XSTRING(STACKNAME),
14732 #ifdef STACKALIAS
14733 __XSTRING(STACKALIAS),
14734 #endif
14735 };
14736
14737 static bool bbr_mod_inited = false;
14738
14739 static int
tcp_addbbr(module_t mod,int32_t type,void * data)14740 tcp_addbbr(module_t mod, int32_t type, void *data)
14741 {
14742 int32_t err = 0;
14743 int num_stacks;
14744
14745 switch (type) {
14746 case MOD_LOAD:
14747 printf("Attempting to load " __XSTRING(MODNAME) "\n");
14748 bbr_zone = uma_zcreate(__XSTRING(MODNAME) "_map",
14749 sizeof(struct bbr_sendmap),
14750 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0);
14751 bbr_pcb_zone = uma_zcreate(__XSTRING(MODNAME) "_pcb",
14752 sizeof(struct tcp_bbr),
14753 NULL, NULL, NULL, NULL, UMA_ALIGN_CACHE, 0);
14754 sysctl_ctx_init(&bbr_sysctl_ctx);
14755 bbr_sysctl_root = SYSCTL_ADD_NODE(&bbr_sysctl_ctx,
14756 SYSCTL_STATIC_CHILDREN(_net_inet_tcp),
14757 OID_AUTO,
14758 #ifdef STACKALIAS
14759 __XSTRING(STACKALIAS),
14760 #else
14761 __XSTRING(STACKNAME),
14762 #endif
14763 CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
14764 "");
14765 if (bbr_sysctl_root == NULL) {
14766 printf("Failed to add sysctl node\n");
14767 err = EFAULT;
14768 goto free_uma;
14769 }
14770 bbr_init_sysctls();
14771 num_stacks = nitems(bbr_stack_names);
14772 err = register_tcp_functions_as_names(&__tcp_bbr, M_WAITOK,
14773 bbr_stack_names, &num_stacks);
14774 if (err) {
14775 printf("Failed to register %s stack name for "
14776 "%s module\n", bbr_stack_names[num_stacks],
14777 __XSTRING(MODNAME));
14778 sysctl_ctx_free(&bbr_sysctl_ctx);
14779 free_uma:
14780 uma_zdestroy(bbr_zone);
14781 uma_zdestroy(bbr_pcb_zone);
14782 bbr_counter_destroy();
14783 printf("Failed to register " __XSTRING(MODNAME)
14784 " module err:%d\n", err);
14785 return (err);
14786 }
14787 tcp_lro_reg_mbufq();
14788 bbr_mod_inited = true;
14789 printf(__XSTRING(MODNAME) " is now available\n");
14790 break;
14791 case MOD_QUIESCE:
14792 err = deregister_tcp_functions(&__tcp_bbr, true, false);
14793 break;
14794 case MOD_UNLOAD:
14795 err = deregister_tcp_functions(&__tcp_bbr, false, true);
14796 if (err == EBUSY)
14797 break;
14798 if (bbr_mod_inited) {
14799 uma_zdestroy(bbr_zone);
14800 uma_zdestroy(bbr_pcb_zone);
14801 sysctl_ctx_free(&bbr_sysctl_ctx);
14802 bbr_counter_destroy();
14803 printf(__XSTRING(MODNAME)
14804 " is now no longer available\n");
14805 bbr_mod_inited = false;
14806 }
14807 tcp_lro_dereg_mbufq();
14808 err = 0;
14809 break;
14810 default:
14811 return (EOPNOTSUPP);
14812 }
14813 return (err);
14814 }
14815
14816 static moduledata_t tcp_bbr = {
14817 .name = __XSTRING(MODNAME),
14818 .evhand = tcp_addbbr,
14819 .priv = 0
14820 };
14821
14822 MODULE_VERSION(MODNAME, 1);
14823 DECLARE_MODULE(MODNAME, tcp_bbr, SI_SUB_PROTO_DOMAIN, SI_ORDER_ANY);
14824 MODULE_DEPEND(MODNAME, tcphpts, 1, 1, 1);
14825