1 /*-
2 * Copyright (c) 2001-2007, by Cisco Systems, Inc. All rights reserved.
3 * Copyright (c) 2008-2012, by Randall Stewart. All rights reserved.
4 * Copyright (c) 2008-2012, by Michael Tuexen. All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions are met:
8 *
9 * a) Redistributions of source code must retain the above copyright notice,
10 * this list of conditions and the following disclaimer.
11 *
12 * b) Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in
14 * the documentation and/or other materials provided with the distribution.
15 *
16 * c) Neither the name of Cisco Systems, Inc. nor the names of its
17 * contributors may be used to endorse or promote products derived
18 * from this software without specific prior written permission.
19 *
20 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
21 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
22 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
24 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
25 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
26 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
27 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
28 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
29 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
30 * THE POSSIBILITY OF SUCH DAMAGE.
31 */
32
33 #include <sys/cdefs.h>
34 __FBSDID("$FreeBSD: releng/10.1/sys/netinet/sctp_cc_functions.c 271750 2014-09-18 09:49:49Z tuexen $");
35
36 #include <netinet/sctp_os.h>
37 #include <netinet/sctp_var.h>
38 #include <netinet/sctp_sysctl.h>
39 #include <netinet/sctp_pcb.h>
40 #include <netinet/sctp_header.h>
41 #include <netinet/sctputil.h>
42 #include <netinet/sctp_output.h>
43 #include <netinet/sctp_input.h>
44 #include <netinet/sctp_indata.h>
45 #include <netinet/sctp_uio.h>
46 #include <netinet/sctp_timer.h>
47 #include <netinet/sctp_auth.h>
48 #include <netinet/sctp_asconf.h>
49 #include <netinet/sctp_dtrace_declare.h>
50
51 #define SHIFT_MPTCP_MULTI_N 40
52 #define SHIFT_MPTCP_MULTI_Z 16
53 #define SHIFT_MPTCP_MULTI 8
54
55 static void
56 sctp_set_initial_cc_param(struct sctp_tcb *stcb, struct sctp_nets *net)
57 {
58 struct sctp_association *assoc;
59 uint32_t cwnd_in_mtu;
60
61 assoc = &stcb->asoc;
62 cwnd_in_mtu = SCTP_BASE_SYSCTL(sctp_initial_cwnd);
63 if (cwnd_in_mtu == 0) {
64 /* Using 0 means that the value of RFC 4960 is used. */
65 net->cwnd = min((net->mtu * 4), max((2 * net->mtu), SCTP_INITIAL_CWND));
66 } else {
67 /*
68 * We take the minimum of the burst limit and the initial
69 * congestion window.
70 */
71 if ((assoc->max_burst > 0) && (cwnd_in_mtu > assoc->max_burst))
72 cwnd_in_mtu = assoc->max_burst;
73 net->cwnd = (net->mtu - sizeof(struct sctphdr)) * cwnd_in_mtu;
74 }
75 if ((stcb->asoc.sctp_cmt_on_off == SCTP_CMT_RPV1) ||
76 (stcb->asoc.sctp_cmt_on_off == SCTP_CMT_RPV2)) {
77 /* In case of resource pooling initialize appropriately */
78 net->cwnd /= assoc->numnets;
79 if (net->cwnd < (net->mtu - sizeof(struct sctphdr))) {
80 net->cwnd = net->mtu - sizeof(struct sctphdr);
81 }
82 }
83 net->ssthresh = assoc->peers_rwnd;
84 SDT_PROBE(sctp, cwnd, net, init,
85 stcb->asoc.my_vtag, ((stcb->sctp_ep->sctp_lport << 16) | (stcb->rport)), net,
86 0, net->cwnd);
87 if (SCTP_BASE_SYSCTL(sctp_logging_level) &
88 (SCTP_CWND_MONITOR_ENABLE | SCTP_CWND_LOGGING_ENABLE)) {
89 sctp_log_cwnd(stcb, net, 0, SCTP_CWND_INITIALIZATION);
90 }
91 }
92
93 static void
94 sctp_cwnd_update_after_fr(struct sctp_tcb *stcb,
95 struct sctp_association *asoc)
96 {
97 struct sctp_nets *net;
98 uint32_t t_ssthresh, t_cwnd;
99 uint64_t t_ucwnd_sbw;
100
101 /* MT FIXME: Don't compute this over and over again */
102 t_ssthresh = 0;
103 t_cwnd = 0;
104 t_ucwnd_sbw = 0;
105 if ((asoc->sctp_cmt_on_off == SCTP_CMT_RPV1) ||
106 (asoc->sctp_cmt_on_off == SCTP_CMT_RPV2)) {
107 TAILQ_FOREACH(net, &asoc->nets, sctp_next) {
108 t_ssthresh += net->ssthresh;
109 t_cwnd += net->cwnd;
110 if (net->lastsa > 0) {
111 t_ucwnd_sbw += (uint64_t) net->cwnd / (uint64_t) net->lastsa;
112 }
113 }
114 if (t_ucwnd_sbw == 0) {
115 t_ucwnd_sbw = 1;
116 }
117 }
118 /*-
119 * CMT fast recovery code. Need to debug. ((sctp_cmt_on_off > 0) &&
120 * (net->fast_retran_loss_recovery == 0)))
121 */
122 TAILQ_FOREACH(net, &asoc->nets, sctp_next) {
123 if ((asoc->fast_retran_loss_recovery == 0) ||
124 (asoc->sctp_cmt_on_off > 0)) {
125 /* out of a RFC2582 Fast recovery window? */
126 if (net->net_ack > 0) {
127 /*
128 * per section 7.2.3, are there any
129 * destinations that had a fast retransmit
130 * to them. If so what we need to do is
131 * adjust ssthresh and cwnd.
132 */
133 struct sctp_tmit_chunk *lchk;
134 int old_cwnd = net->cwnd;
135
136 if ((asoc->sctp_cmt_on_off == SCTP_CMT_RPV1) ||
137 (asoc->sctp_cmt_on_off == SCTP_CMT_RPV2)) {
138 if (asoc->sctp_cmt_on_off == SCTP_CMT_RPV1) {
139 net->ssthresh = (uint32_t) (((uint64_t) 4 *
140 (uint64_t) net->mtu *
141 (uint64_t) net->ssthresh) /
142 (uint64_t) t_ssthresh);
143
144 }
145 if (asoc->sctp_cmt_on_off == SCTP_CMT_RPV2) {
146 uint32_t srtt;
147
148 srtt = net->lastsa;
149 /*
150 * lastsa>>3; we don't need
151 * to devide ...
152 */
153 if (srtt == 0) {
154 srtt = 1;
155 }
156 /*
157 * Short Version => Equal to
158 * Contel Version MBe
159 */
160 net->ssthresh = (uint32_t) (((uint64_t) 4 *
161 (uint64_t) net->mtu *
162 (uint64_t) net->cwnd) /
163 ((uint64_t) srtt *
164 t_ucwnd_sbw));
165 /* INCREASE FACTOR */ ;
166 }
167 if ((net->cwnd > t_cwnd / 2) &&
168 (net->ssthresh < net->cwnd - t_cwnd / 2)) {
169 net->ssthresh = net->cwnd - t_cwnd / 2;
170 }
171 if (net->ssthresh < net->mtu) {
172 net->ssthresh = net->mtu;
173 }
174 } else {
175 net->ssthresh = net->cwnd / 2;
176 if (net->ssthresh < (net->mtu * 2)) {
177 net->ssthresh = 2 * net->mtu;
178 }
179 }
180 net->cwnd = net->ssthresh;
181 SDT_PROBE(sctp, cwnd, net, fr,
182 stcb->asoc.my_vtag, ((stcb->sctp_ep->sctp_lport << 16) | (stcb->rport)), net,
183 old_cwnd, net->cwnd);
184 if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_CWND_MONITOR_ENABLE) {
185 sctp_log_cwnd(stcb, net, (net->cwnd - old_cwnd),
186 SCTP_CWND_LOG_FROM_FR);
187 }
188 lchk = TAILQ_FIRST(&asoc->send_queue);
189
190 net->partial_bytes_acked = 0;
191 /* Turn on fast recovery window */
192 asoc->fast_retran_loss_recovery = 1;
193 if (lchk == NULL) {
194 /* Mark end of the window */
195 asoc->fast_recovery_tsn = asoc->sending_seq - 1;
196 } else {
197 asoc->fast_recovery_tsn = lchk->rec.data.TSN_seq - 1;
198 }
199
200 /*
201 * CMT fast recovery -- per destination
202 * recovery variable.
203 */
204 net->fast_retran_loss_recovery = 1;
205
206 if (lchk == NULL) {
207 /* Mark end of the window */
208 net->fast_recovery_tsn = asoc->sending_seq - 1;
209 } else {
210 net->fast_recovery_tsn = lchk->rec.data.TSN_seq - 1;
211 }
212
213 sctp_timer_stop(SCTP_TIMER_TYPE_SEND,
214 stcb->sctp_ep, stcb, net, SCTP_FROM_SCTP_INDATA + SCTP_LOC_32);
215 sctp_timer_start(SCTP_TIMER_TYPE_SEND,
216 stcb->sctp_ep, stcb, net);
217 }
218 } else if (net->net_ack > 0) {
219 /*
220 * Mark a peg that we WOULD have done a cwnd
221 * reduction but RFC2582 prevented this action.
222 */
223 SCTP_STAT_INCR(sctps_fastretransinrtt);
224 }
225 }
226 }
227
228 /* Defines for instantaneous bw decisions */
229 #define SCTP_INST_LOOSING 1 /* Loosing to other flows */
230 #define SCTP_INST_NEUTRAL 2 /* Neutral, no indication */
231 #define SCTP_INST_GAINING 3 /* Gaining, step down possible */
232
233
234 static int
235 cc_bw_same(struct sctp_tcb *stcb, struct sctp_nets *net, uint64_t nbw,
236 uint64_t rtt_offset, uint64_t vtag, uint8_t inst_ind)
237 {
238 uint64_t oth, probepoint;
239
240 probepoint = (((uint64_t) net->cwnd) << 32);
241 if (net->rtt > net->cc_mod.rtcc.lbw_rtt + rtt_offset) {
242 /*
243 * rtt increased we don't update bw.. so we don't update the
244 * rtt either.
245 */
246 /* Probe point 5 */
247 probepoint |= ((5 << 16) | 1);
248 SDT_PROBE(sctp, cwnd, net, rttvar,
249 vtag,
250 ((net->cc_mod.rtcc.lbw << 32) | nbw),
251 ((net->cc_mod.rtcc.lbw_rtt << 32) | net->rtt),
252 net->flight_size,
253 probepoint);
254 if ((net->cc_mod.rtcc.steady_step) && (inst_ind != SCTP_INST_LOOSING)) {
255 if (net->cc_mod.rtcc.last_step_state == 5)
256 net->cc_mod.rtcc.step_cnt++;
257 else
258 net->cc_mod.rtcc.step_cnt = 1;
259 net->cc_mod.rtcc.last_step_state = 5;
260 if ((net->cc_mod.rtcc.step_cnt == net->cc_mod.rtcc.steady_step) ||
261 ((net->cc_mod.rtcc.step_cnt > net->cc_mod.rtcc.steady_step) &&
262 ((net->cc_mod.rtcc.step_cnt % net->cc_mod.rtcc.steady_step) == 0))) {
263 /* Try a step down */
264 oth = net->cc_mod.rtcc.vol_reduce;
265 oth <<= 16;
266 oth |= net->cc_mod.rtcc.step_cnt;
267 oth <<= 16;
268 oth |= net->cc_mod.rtcc.last_step_state;
269 SDT_PROBE(sctp, cwnd, net, rttstep,
270 vtag,
271 ((net->cc_mod.rtcc.lbw << 32) | nbw),
272 ((net->cc_mod.rtcc.lbw_rtt << 32) | net->rtt),
273 oth,
274 probepoint);
275 if (net->cwnd > (4 * net->mtu)) {
276 net->cwnd -= net->mtu;
277 net->cc_mod.rtcc.vol_reduce++;
278 } else {
279 net->cc_mod.rtcc.step_cnt = 0;
280 }
281 }
282 }
283 return (1);
284 }
285 if (net->rtt < net->cc_mod.rtcc.lbw_rtt - rtt_offset) {
286 /*
287 * rtt decreased, there could be more room. we update both
288 * the bw and the rtt here to lock this in as a good step
289 * down.
290 */
291 /* Probe point 6 */
292 probepoint |= ((6 << 16) | 0);
293 SDT_PROBE(sctp, cwnd, net, rttvar,
294 vtag,
295 ((net->cc_mod.rtcc.lbw << 32) | nbw),
296 ((net->cc_mod.rtcc.lbw_rtt << 32) | net->rtt),
297 net->flight_size,
298 probepoint);
299 if (net->cc_mod.rtcc.steady_step) {
300 oth = net->cc_mod.rtcc.vol_reduce;
301 oth <<= 16;
302 oth |= net->cc_mod.rtcc.step_cnt;
303 oth <<= 16;
304 oth |= net->cc_mod.rtcc.last_step_state;
305 SDT_PROBE(sctp, cwnd, net, rttstep,
306 vtag,
307 ((net->cc_mod.rtcc.lbw << 32) | nbw),
308 ((net->cc_mod.rtcc.lbw_rtt << 32) | net->rtt),
309 oth,
310 probepoint);
311 if ((net->cc_mod.rtcc.last_step_state == 5) &&
312 (net->cc_mod.rtcc.step_cnt > net->cc_mod.rtcc.steady_step)) {
313 /* Step down worked */
314 net->cc_mod.rtcc.step_cnt = 0;
315 return (1);
316 } else {
317 net->cc_mod.rtcc.last_step_state = 6;
318 net->cc_mod.rtcc.step_cnt = 0;
319 }
320 }
321 net->cc_mod.rtcc.lbw = nbw;
322 net->cc_mod.rtcc.lbw_rtt = net->rtt;
323 net->cc_mod.rtcc.cwnd_at_bw_set = net->cwnd;
324 if (inst_ind == SCTP_INST_GAINING)
325 return (1);
326 else if (inst_ind == SCTP_INST_NEUTRAL)
327 return (1);
328 else
329 return (0);
330 }
331 /*
332 * Ok bw and rtt remained the same .. no update to any
333 */
334 /* Probe point 7 */
335 probepoint |= ((7 << 16) | net->cc_mod.rtcc.ret_from_eq);
336 SDT_PROBE(sctp, cwnd, net, rttvar,
337 vtag,
338 ((net->cc_mod.rtcc.lbw << 32) | nbw),
339 ((net->cc_mod.rtcc.lbw_rtt << 32) | net->rtt),
340 net->flight_size,
341 probepoint);
342 if ((net->cc_mod.rtcc.steady_step) && (inst_ind != SCTP_INST_LOOSING)) {
343 if (net->cc_mod.rtcc.last_step_state == 5)
344 net->cc_mod.rtcc.step_cnt++;
345 else
346 net->cc_mod.rtcc.step_cnt = 1;
347 net->cc_mod.rtcc.last_step_state = 5;
348 if ((net->cc_mod.rtcc.step_cnt == net->cc_mod.rtcc.steady_step) ||
349 ((net->cc_mod.rtcc.step_cnt > net->cc_mod.rtcc.steady_step) &&
350 ((net->cc_mod.rtcc.step_cnt % net->cc_mod.rtcc.steady_step) == 0))) {
351 /* Try a step down */
352 if (net->cwnd > (4 * net->mtu)) {
353 net->cwnd -= net->mtu;
354 net->cc_mod.rtcc.vol_reduce++;
355 return (1);
356 } else {
357 net->cc_mod.rtcc.step_cnt = 0;
358 }
359 }
360 }
361 if (inst_ind == SCTP_INST_GAINING)
362 return (1);
363 else if (inst_ind == SCTP_INST_NEUTRAL)
364 return (1);
365 else
366 return ((int)net->cc_mod.rtcc.ret_from_eq);
367 }
368
369 static int
370 cc_bw_decrease(struct sctp_tcb *stcb, struct sctp_nets *net, uint64_t nbw, uint64_t rtt_offset,
371 uint64_t vtag, uint8_t inst_ind)
372 {
373 uint64_t oth, probepoint;
374
375 /* Bandwidth decreased. */
376 probepoint = (((uint64_t) net->cwnd) << 32);
377 if (net->rtt > net->cc_mod.rtcc.lbw_rtt + rtt_offset) {
378 /* rtt increased */
379 /* Did we add more */
380 if ((net->cwnd > net->cc_mod.rtcc.cwnd_at_bw_set) &&
381 (inst_ind != SCTP_INST_LOOSING)) {
382 /* We caused it maybe.. back off? */
383 /* PROBE POINT 1 */
384 probepoint |= ((1 << 16) | 1);
385 SDT_PROBE(sctp, cwnd, net, rttvar,
386 vtag,
387 ((net->cc_mod.rtcc.lbw << 32) | nbw),
388 ((net->cc_mod.rtcc.lbw_rtt << 32) | net->rtt),
389 net->flight_size,
390 probepoint);
391 if (net->cc_mod.rtcc.ret_from_eq) {
392 /*
393 * Switch over to CA if we are less
394 * aggressive
395 */
396 net->ssthresh = net->cwnd - 1;
397 net->partial_bytes_acked = 0;
398 }
399 return (1);
400 }
401 /* Probe point 2 */
402 probepoint |= ((2 << 16) | 0);
403 SDT_PROBE(sctp, cwnd, net, rttvar,
404 vtag,
405 ((net->cc_mod.rtcc.lbw << 32) | nbw),
406 ((net->cc_mod.rtcc.lbw_rtt << 32) | net->rtt),
407 net->flight_size,
408 probepoint);
409 /* Someone else - fight for more? */
410 if (net->cc_mod.rtcc.steady_step) {
411 oth = net->cc_mod.rtcc.vol_reduce;
412 oth <<= 16;
413 oth |= net->cc_mod.rtcc.step_cnt;
414 oth <<= 16;
415 oth |= net->cc_mod.rtcc.last_step_state;
416 SDT_PROBE(sctp, cwnd, net, rttstep,
417 vtag,
418 ((net->cc_mod.rtcc.lbw << 32) | nbw),
419 ((net->cc_mod.rtcc.lbw_rtt << 32) | net->rtt),
420 oth,
421 probepoint);
422 /*
423 * Did we voluntarily give up some? if so take one
424 * back please
425 */
426 if ((net->cc_mod.rtcc.vol_reduce) &&
427 (inst_ind != SCTP_INST_GAINING)) {
428 net->cwnd += net->mtu;
429 net->cc_mod.rtcc.vol_reduce--;
430 }
431 net->cc_mod.rtcc.last_step_state = 2;
432 net->cc_mod.rtcc.step_cnt = 0;
433 }
434 goto out_decision;
435 } else if (net->rtt < net->cc_mod.rtcc.lbw_rtt - rtt_offset) {
436 /* bw & rtt decreased */
437 /* Probe point 3 */
438 probepoint |= ((3 << 16) | 0);
439 SDT_PROBE(sctp, cwnd, net, rttvar,
440 vtag,
441 ((net->cc_mod.rtcc.lbw << 32) | nbw),
442 ((net->cc_mod.rtcc.lbw_rtt << 32) | net->rtt),
443 net->flight_size,
444 probepoint);
445 if (net->cc_mod.rtcc.steady_step) {
446 oth = net->cc_mod.rtcc.vol_reduce;
447 oth <<= 16;
448 oth |= net->cc_mod.rtcc.step_cnt;
449 oth <<= 16;
450 oth |= net->cc_mod.rtcc.last_step_state;
451 SDT_PROBE(sctp, cwnd, net, rttstep,
452 vtag,
453 ((net->cc_mod.rtcc.lbw << 32) | nbw),
454 ((net->cc_mod.rtcc.lbw_rtt << 32) | net->rtt),
455 oth,
456 probepoint);
457 if ((net->cc_mod.rtcc.vol_reduce) &&
458 (inst_ind != SCTP_INST_GAINING)) {
459 net->cwnd += net->mtu;
460 net->cc_mod.rtcc.vol_reduce--;
461 }
462 net->cc_mod.rtcc.last_step_state = 3;
463 net->cc_mod.rtcc.step_cnt = 0;
464 }
465 goto out_decision;
466 }
467 /* The bw decreased but rtt stayed the same */
468 /* Probe point 4 */
469 probepoint |= ((4 << 16) | 0);
470 SDT_PROBE(sctp, cwnd, net, rttvar,
471 vtag,
472 ((net->cc_mod.rtcc.lbw << 32) | nbw),
473 ((net->cc_mod.rtcc.lbw_rtt << 32) | net->rtt),
474 net->flight_size,
475 probepoint);
476 if (net->cc_mod.rtcc.steady_step) {
477 oth = net->cc_mod.rtcc.vol_reduce;
478 oth <<= 16;
479 oth |= net->cc_mod.rtcc.step_cnt;
480 oth <<= 16;
481 oth |= net->cc_mod.rtcc.last_step_state;
482 SDT_PROBE(sctp, cwnd, net, rttstep,
483 vtag,
484 ((net->cc_mod.rtcc.lbw << 32) | nbw),
485 ((net->cc_mod.rtcc.lbw_rtt << 32) | net->rtt),
486 oth,
487 probepoint);
488 if ((net->cc_mod.rtcc.vol_reduce) &&
489 (inst_ind != SCTP_INST_GAINING)) {
490 net->cwnd += net->mtu;
491 net->cc_mod.rtcc.vol_reduce--;
492 }
493 net->cc_mod.rtcc.last_step_state = 4;
494 net->cc_mod.rtcc.step_cnt = 0;
495 }
496 out_decision:
497 net->cc_mod.rtcc.lbw = nbw;
498 net->cc_mod.rtcc.lbw_rtt = net->rtt;
499 net->cc_mod.rtcc.cwnd_at_bw_set = net->cwnd;
500 if (inst_ind == SCTP_INST_GAINING) {
501 return (1);
502 } else {
503 return (0);
504 }
505 }
506
507 static int
508 cc_bw_increase(struct sctp_tcb *stcb, struct sctp_nets *net, uint64_t nbw, uint64_t vtag)
509 {
510 uint64_t oth, probepoint;
511
512 /*
513 * BW increased, so update and return 0, since all actions in our
514 * table say to do the normal CC update. Note that we pay no
515 * attention to the inst_ind since our overall sum is increasing.
516 */
517 /* PROBE POINT 0 */
518 probepoint = (((uint64_t) net->cwnd) << 32);
519 SDT_PROBE(sctp, cwnd, net, rttvar,
520 vtag,
521 ((net->cc_mod.rtcc.lbw << 32) | nbw),
522 ((net->cc_mod.rtcc.lbw_rtt << 32) | net->rtt),
523 net->flight_size,
524 probepoint);
525 if (net->cc_mod.rtcc.steady_step) {
526 oth = net->cc_mod.rtcc.vol_reduce;
527 oth <<= 16;
528 oth |= net->cc_mod.rtcc.step_cnt;
529 oth <<= 16;
530 oth |= net->cc_mod.rtcc.last_step_state;
531 SDT_PROBE(sctp, cwnd, net, rttstep,
532 vtag,
533 ((net->cc_mod.rtcc.lbw << 32) | nbw),
534 ((net->cc_mod.rtcc.lbw_rtt << 32) | net->rtt),
535 oth,
536 probepoint);
537 net->cc_mod.rtcc.last_step_state = 0;
538 net->cc_mod.rtcc.step_cnt = 0;
539 net->cc_mod.rtcc.vol_reduce = 0;
540 }
541 net->cc_mod.rtcc.lbw = nbw;
542 net->cc_mod.rtcc.lbw_rtt = net->rtt;
543 net->cc_mod.rtcc.cwnd_at_bw_set = net->cwnd;
544 return (0);
545 }
546
547 /* RTCC Algoritm to limit growth of cwnd, return
548 * true if you want to NOT allow cwnd growth
549 */
550 static int
551 cc_bw_limit(struct sctp_tcb *stcb, struct sctp_nets *net, uint64_t nbw)
552 {
553 uint64_t bw_offset, rtt_offset;
554 uint64_t probepoint, rtt, vtag;
555 uint64_t bytes_for_this_rtt, inst_bw;
556 uint64_t div, inst_off;
557 int bw_shift;
558 uint8_t inst_ind;
559 int ret;
560
561 /*-
562 * Here we need to see if we want
563 * to limit cwnd growth due to increase
564 * in overall rtt but no increase in bw.
565 * We use the following table to figure
566 * out what we should do. When we return
567 * 0, cc update goes on as planned. If we
568 * return 1, then no cc update happens and cwnd
569 * stays where it is at.
570 * ----------------------------------
571 * BW | RTT | Action
572 * *********************************
573 * INC | INC | return 0
574 * ----------------------------------
575 * INC | SAME | return 0
576 * ----------------------------------
577 * INC | DECR | return 0
578 * ----------------------------------
579 * SAME | INC | return 1
580 * ----------------------------------
581 * SAME | SAME | return 1
582 * ----------------------------------
583 * SAME | DECR | return 0
584 * ----------------------------------
585 * DECR | INC | return 0 or 1 based on if we caused.
586 * ----------------------------------
587 * DECR | SAME | return 0
588 * ----------------------------------
589 * DECR | DECR | return 0
590 * ----------------------------------
591 *
592 * We are a bit fuzz on what an increase or
593 * decrease is. For BW it is the same if
594 * it did not change within 1/64th. For
595 * RTT it stayed the same if it did not
596 * change within 1/32nd
597 */
598 bw_shift = SCTP_BASE_SYSCTL(sctp_rttvar_bw);
599 rtt = stcb->asoc.my_vtag;
600 vtag = (rtt << 32) | (((uint32_t) (stcb->sctp_ep->sctp_lport)) << 16) | (stcb->rport);
601 probepoint = (((uint64_t) net->cwnd) << 32);
602 rtt = net->rtt;
603 if (net->cc_mod.rtcc.rtt_set_this_sack) {
604 net->cc_mod.rtcc.rtt_set_this_sack = 0;
605 bytes_for_this_rtt = net->cc_mod.rtcc.bw_bytes - net->cc_mod.rtcc.bw_bytes_at_last_rttc;
606 net->cc_mod.rtcc.bw_bytes_at_last_rttc = net->cc_mod.rtcc.bw_bytes;
607 if (net->rtt) {
608 div = net->rtt / 1000;
609 if (div) {
610 inst_bw = bytes_for_this_rtt / div;
611 inst_off = inst_bw >> bw_shift;
612 if (inst_bw > nbw)
613 inst_ind = SCTP_INST_GAINING;
614 else if ((inst_bw + inst_off) < nbw)
615 inst_ind = SCTP_INST_LOOSING;
616 else
617 inst_ind = SCTP_INST_NEUTRAL;
618 probepoint |= ((0xb << 16) | inst_ind);
619 } else {
620 inst_ind = net->cc_mod.rtcc.last_inst_ind;
621 inst_bw = bytes_for_this_rtt / (uint64_t) (net->rtt);
622 /* Can't determine do not change */
623 probepoint |= ((0xc << 16) | inst_ind);
624 }
625 } else {
626 inst_ind = net->cc_mod.rtcc.last_inst_ind;
627 inst_bw = bytes_for_this_rtt;
628 /* Can't determine do not change */
629 probepoint |= ((0xd << 16) | inst_ind);
630 }
631 SDT_PROBE(sctp, cwnd, net, rttvar,
632 vtag,
633 ((nbw << 32) | inst_bw),
634 ((net->cc_mod.rtcc.lbw_rtt << 32) | rtt),
635 net->flight_size,
636 probepoint);
637 } else {
638 /* No rtt measurement, use last one */
639 inst_ind = net->cc_mod.rtcc.last_inst_ind;
640 }
641 bw_offset = net->cc_mod.rtcc.lbw >> bw_shift;
642 if (nbw > net->cc_mod.rtcc.lbw + bw_offset) {
643 ret = cc_bw_increase(stcb, net, nbw, vtag);
644 goto out;
645 }
646 rtt_offset = net->cc_mod.rtcc.lbw_rtt >> SCTP_BASE_SYSCTL(sctp_rttvar_rtt);
647 if (nbw < net->cc_mod.rtcc.lbw - bw_offset) {
648 ret = cc_bw_decrease(stcb, net, nbw, rtt_offset, vtag, inst_ind);
649 goto out;
650 }
651 /*
652 * If we reach here then we are in a situation where the bw stayed
653 * the same.
654 */
655 ret = cc_bw_same(stcb, net, nbw, rtt_offset, vtag, inst_ind);
656 out:
657 net->cc_mod.rtcc.last_inst_ind = inst_ind;
658 return (ret);
659 }
660
661 static void
662 sctp_cwnd_update_after_sack_common(struct sctp_tcb *stcb,
663 struct sctp_association *asoc,
664 int accum_moved, int reneged_all SCTP_UNUSED, int will_exit, int use_rtcc)
665 {
666 struct sctp_nets *net;
667 int old_cwnd;
668 uint32_t t_ssthresh, t_cwnd, incr;
669 uint64_t t_ucwnd_sbw;
670 uint64_t t_path_mptcp;
671 uint64_t mptcp_like_alpha;
672 uint32_t srtt;
673 uint64_t max_path;
674
675 /* MT FIXME: Don't compute this over and over again */
676 t_ssthresh = 0;
677 t_cwnd = 0;
678 t_ucwnd_sbw = 0;
679 t_path_mptcp = 0;
680 mptcp_like_alpha = 1;
681 if ((stcb->asoc.sctp_cmt_on_off == SCTP_CMT_RPV1) ||
682 (stcb->asoc.sctp_cmt_on_off == SCTP_CMT_RPV2) ||
683 (stcb->asoc.sctp_cmt_on_off == SCTP_CMT_MPTCP)) {
684 max_path = 0;
685 TAILQ_FOREACH(net, &stcb->asoc.nets, sctp_next) {
686 t_ssthresh += net->ssthresh;
687 t_cwnd += net->cwnd;
688 /* lastsa>>3; we don't need to devide ... */
689 srtt = net->lastsa;
690 if (srtt > 0) {
691 uint64_t tmp;
692
693 t_ucwnd_sbw += (uint64_t) net->cwnd / (uint64_t) srtt;
694 t_path_mptcp += (((uint64_t) net->cwnd) << SHIFT_MPTCP_MULTI_Z) /
695 (((uint64_t) net->mtu) * (uint64_t) srtt);
696 tmp = (((uint64_t) net->cwnd) << SHIFT_MPTCP_MULTI_N) /
697 ((uint64_t) net->mtu * (uint64_t) (srtt * srtt));
698 if (tmp > max_path) {
699 max_path = tmp;
700 }
701 }
702 }
703 if (t_path_mptcp > 0) {
704 mptcp_like_alpha = max_path / (t_path_mptcp * t_path_mptcp);
705 } else {
706 mptcp_like_alpha = 1;
707 }
708 }
709 if (t_ssthresh == 0) {
710 t_ssthresh = 1;
711 }
712 if (t_ucwnd_sbw == 0) {
713 t_ucwnd_sbw = 1;
714 }
715 /******************************/
716 /* update cwnd and Early FR */
717 /******************************/
718 TAILQ_FOREACH(net, &asoc->nets, sctp_next) {
719
720 #ifdef JANA_CMT_FAST_RECOVERY
721 /*
722 * CMT fast recovery code. Need to debug.
723 */
724 if (net->fast_retran_loss_recovery && net->new_pseudo_cumack) {
725 if (SCTP_TSN_GE(asoc->last_acked_seq, net->fast_recovery_tsn) ||
726 SCTP_TSN_GE(net->pseudo_cumack, net->fast_recovery_tsn)) {
727 net->will_exit_fast_recovery = 1;
728 }
729 }
730 #endif
731 /* if nothing was acked on this destination skip it */
732 if (net->net_ack == 0) {
733 if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_CWND_LOGGING_ENABLE) {
734 sctp_log_cwnd(stcb, net, 0, SCTP_CWND_LOG_FROM_SACK);
735 }
736 continue;
737 }
738 #ifdef JANA_CMT_FAST_RECOVERY
739 /*
740 * CMT fast recovery code
741 */
742 /*
743 * if (sctp_cmt_on_off > 0 && net->fast_retran_loss_recovery
744 * && net->will_exit_fast_recovery == 0) { @@@ Do something
745 * } else if (sctp_cmt_on_off == 0 &&
746 * asoc->fast_retran_loss_recovery && will_exit == 0) {
747 */
748 #endif
749
750 if (asoc->fast_retran_loss_recovery &&
751 (will_exit == 0) &&
752 (asoc->sctp_cmt_on_off == 0)) {
753 /*
754 * If we are in loss recovery we skip any cwnd
755 * update
756 */
757 return;
758 }
759 /*
760 * Did any measurements go on for this network?
761 */
762 if (use_rtcc && (net->cc_mod.rtcc.tls_needs_set > 0)) {
763 uint64_t nbw;
764
765 /*
766 * At this point our bw_bytes has been updated by
767 * incoming sack information.
768 *
769 * But our bw may not yet be set.
770 *
771 */
772 if ((net->cc_mod.rtcc.new_tot_time / 1000) > 0) {
773 nbw = net->cc_mod.rtcc.bw_bytes / (net->cc_mod.rtcc.new_tot_time / 1000);
774 } else {
775 nbw = net->cc_mod.rtcc.bw_bytes;
776 }
777 if (net->cc_mod.rtcc.lbw) {
778 if (cc_bw_limit(stcb, net, nbw)) {
779 /* Hold here, no update */
780 continue;
781 }
782 } else {
783 uint64_t vtag, probepoint;
784
785 probepoint = (((uint64_t) net->cwnd) << 32);
786 probepoint |= ((0xa << 16) | 0);
787 vtag = (net->rtt << 32) |
788 (((uint32_t) (stcb->sctp_ep->sctp_lport)) << 16) |
789 (stcb->rport);
790
791 SDT_PROBE(sctp, cwnd, net, rttvar,
792 vtag,
793 nbw,
794 ((net->cc_mod.rtcc.lbw_rtt << 32) | net->rtt),
795 net->flight_size,
796 probepoint);
797 net->cc_mod.rtcc.lbw = nbw;
798 net->cc_mod.rtcc.lbw_rtt = net->rtt;
799 if (net->cc_mod.rtcc.rtt_set_this_sack) {
800 net->cc_mod.rtcc.rtt_set_this_sack = 0;
801 net->cc_mod.rtcc.bw_bytes_at_last_rttc = net->cc_mod.rtcc.bw_bytes;
802 }
803 }
804 }
805 /*
806 * CMT: CUC algorithm. Update cwnd if pseudo-cumack has
807 * moved.
808 */
809 if (accum_moved ||
810 ((asoc->sctp_cmt_on_off > 0) && net->new_pseudo_cumack)) {
811 /* If the cumulative ack moved we can proceed */
812 if (net->cwnd <= net->ssthresh) {
813 /* We are in slow start */
814 if (net->flight_size + net->net_ack >= net->cwnd) {
815 uint32_t limit;
816
817 old_cwnd = net->cwnd;
818 switch (asoc->sctp_cmt_on_off) {
819 case SCTP_CMT_RPV1:
820 limit = (uint32_t) (((uint64_t) net->mtu *
821 (uint64_t) SCTP_BASE_SYSCTL(sctp_L2_abc_variable) *
822 (uint64_t) net->ssthresh) /
823 (uint64_t) t_ssthresh);
824 incr = (uint32_t) (((uint64_t) net->net_ack *
825 (uint64_t) net->ssthresh) /
826 (uint64_t) t_ssthresh);
827 if (incr > limit) {
828 incr = limit;
829 }
830 if (incr == 0) {
831 incr = 1;
832 }
833 break;
834 case SCTP_CMT_RPV2:
835 /*
836 * lastsa>>3; we don't need
837 * to divide ...
838 */
839 srtt = net->lastsa;
840 if (srtt == 0) {
841 srtt = 1;
842 }
843 limit = (uint32_t) (((uint64_t) net->mtu *
844 (uint64_t) SCTP_BASE_SYSCTL(sctp_L2_abc_variable) *
845 (uint64_t) net->cwnd) /
846 ((uint64_t) srtt * t_ucwnd_sbw));
847 /* INCREASE FACTOR */
848 incr = (uint32_t) (((uint64_t) net->net_ack *
849 (uint64_t) net->cwnd) /
850 ((uint64_t) srtt * t_ucwnd_sbw));
851 /* INCREASE FACTOR */
852 if (incr > limit) {
853 incr = limit;
854 }
855 if (incr == 0) {
856 incr = 1;
857 }
858 break;
859 case SCTP_CMT_MPTCP:
860 limit = (uint32_t) (((uint64_t) net->mtu *
861 mptcp_like_alpha *
862 (uint64_t) SCTP_BASE_SYSCTL(sctp_L2_abc_variable)) >>
863 SHIFT_MPTCP_MULTI);
864 incr = (uint32_t) (((uint64_t) net->net_ack *
865 mptcp_like_alpha) >>
866 SHIFT_MPTCP_MULTI);
867 if (incr > limit) {
868 incr = limit;
869 }
870 if (incr > net->net_ack) {
871 incr = net->net_ack;
872 }
873 if (incr > net->mtu) {
874 incr = net->mtu;
875 }
876 break;
877 default:
878 incr = net->net_ack;
879 if (incr > net->mtu * SCTP_BASE_SYSCTL(sctp_L2_abc_variable)) {
880 incr = net->mtu * SCTP_BASE_SYSCTL(sctp_L2_abc_variable);
881 }
882 break;
883 }
884 net->cwnd += incr;
885 if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_CWND_MONITOR_ENABLE) {
886 sctp_log_cwnd(stcb, net, incr,
887 SCTP_CWND_LOG_FROM_SS);
888 }
889 SDT_PROBE(sctp, cwnd, net, ack,
890 stcb->asoc.my_vtag,
891 ((stcb->sctp_ep->sctp_lport << 16) | (stcb->rport)),
892 net,
893 old_cwnd, net->cwnd);
894 } else {
895 if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_CWND_LOGGING_ENABLE) {
896 sctp_log_cwnd(stcb, net, net->net_ack,
897 SCTP_CWND_LOG_NOADV_SS);
898 }
899 }
900 } else {
901 /* We are in congestion avoidance */
902 /*
903 * Add to pba
904 */
905 net->partial_bytes_acked += net->net_ack;
906
907 if ((net->flight_size + net->net_ack >= net->cwnd) &&
908 (net->partial_bytes_acked >= net->cwnd)) {
909 net->partial_bytes_acked -= net->cwnd;
910 old_cwnd = net->cwnd;
911 switch (asoc->sctp_cmt_on_off) {
912 case SCTP_CMT_RPV1:
913 incr = (uint32_t) (((uint64_t) net->mtu *
914 (uint64_t) net->ssthresh) /
915 (uint64_t) t_ssthresh);
916 if (incr == 0) {
917 incr = 1;
918 }
919 break;
920 case SCTP_CMT_RPV2:
921 /*
922 * lastsa>>3; we don't need
923 * to divide ...
924 */
925 srtt = net->lastsa;
926 if (srtt == 0) {
927 srtt = 1;
928 }
929 incr = (uint32_t) ((uint64_t) net->mtu *
930 (uint64_t) net->cwnd /
931 ((uint64_t) srtt *
932 t_ucwnd_sbw));
933 /* INCREASE FACTOR */
934 if (incr == 0) {
935 incr = 1;
936 }
937 break;
938 case SCTP_CMT_MPTCP:
939 incr = (uint32_t) ((mptcp_like_alpha *
940 (uint64_t) net->cwnd) >>
941 SHIFT_MPTCP_MULTI);
942 if (incr > net->mtu) {
943 incr = net->mtu;
944 }
945 break;
946 default:
947 incr = net->mtu;
948 break;
949 }
950 net->cwnd += incr;
951 SDT_PROBE(sctp, cwnd, net, ack,
952 stcb->asoc.my_vtag,
953 ((stcb->sctp_ep->sctp_lport << 16) | (stcb->rport)),
954 net,
955 old_cwnd, net->cwnd);
956 if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_CWND_MONITOR_ENABLE) {
957 sctp_log_cwnd(stcb, net, net->mtu,
958 SCTP_CWND_LOG_FROM_CA);
959 }
960 } else {
961 if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_CWND_LOGGING_ENABLE) {
962 sctp_log_cwnd(stcb, net, net->net_ack,
963 SCTP_CWND_LOG_NOADV_CA);
964 }
965 }
966 }
967 } else {
968 if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_CWND_LOGGING_ENABLE) {
969 sctp_log_cwnd(stcb, net, net->mtu,
970 SCTP_CWND_LOG_NO_CUMACK);
971 }
972 }
973 }
974 }
975
976 static void
977 sctp_cwnd_update_exit_pf_common(struct sctp_tcb *stcb, struct sctp_nets *net)
978 {
979 int old_cwnd;
980
981 old_cwnd = net->cwnd;
982 net->cwnd = net->mtu;
983 SDT_PROBE(sctp, cwnd, net, ack,
984 stcb->asoc.my_vtag, ((stcb->sctp_ep->sctp_lport << 16) | (stcb->rport)), net,
985 old_cwnd, net->cwnd);
986 SCTPDBG(SCTP_DEBUG_INDATA1, "Destination %p moved from PF to reachable with cwnd %d.\n",
987 (void *)net, net->cwnd);
988 }
989
990
991 static void
992 sctp_cwnd_update_after_timeout(struct sctp_tcb *stcb, struct sctp_nets *net)
993 {
994 int old_cwnd = net->cwnd;
995 uint32_t t_ssthresh, t_cwnd;
996 uint64_t t_ucwnd_sbw;
997
998 /* MT FIXME: Don't compute this over and over again */
999 t_ssthresh = 0;
1000 t_cwnd = 0;
1001 if ((stcb->asoc.sctp_cmt_on_off == SCTP_CMT_RPV1) ||
1002 (stcb->asoc.sctp_cmt_on_off == SCTP_CMT_RPV2)) {
1003 struct sctp_nets *lnet;
1004 uint32_t srtt;
1005
1006 t_ucwnd_sbw = 0;
1007 TAILQ_FOREACH(lnet, &stcb->asoc.nets, sctp_next) {
1008 t_ssthresh += lnet->ssthresh;
1009 t_cwnd += lnet->cwnd;
1010 srtt = lnet->lastsa;
1011 /* lastsa>>3; we don't need to divide ... */
1012 if (srtt > 0) {
1013 t_ucwnd_sbw += (uint64_t) lnet->cwnd / (uint64_t) srtt;
1014 }
1015 }
1016 if (t_ssthresh < 1) {
1017 t_ssthresh = 1;
1018 }
1019 if (t_ucwnd_sbw < 1) {
1020 t_ucwnd_sbw = 1;
1021 }
1022 if (stcb->asoc.sctp_cmt_on_off == SCTP_CMT_RPV1) {
1023 net->ssthresh = (uint32_t) (((uint64_t) 4 *
1024 (uint64_t) net->mtu *
1025 (uint64_t) net->ssthresh) /
1026 (uint64_t) t_ssthresh);
1027 } else {
1028 uint64_t cc_delta;
1029
1030 srtt = net->lastsa;
1031 /* lastsa>>3; we don't need to divide ... */
1032 if (srtt == 0) {
1033 srtt = 1;
1034 }
1035 cc_delta = t_ucwnd_sbw * (uint64_t) srtt / 2;
1036 if (cc_delta < t_cwnd) {
1037 net->ssthresh = (uint32_t) ((uint64_t) t_cwnd - cc_delta);
1038 } else {
1039 net->ssthresh = net->mtu;
1040 }
1041 }
1042 if ((net->cwnd > t_cwnd / 2) &&
1043 (net->ssthresh < net->cwnd - t_cwnd / 2)) {
1044 net->ssthresh = net->cwnd - t_cwnd / 2;
1045 }
1046 if (net->ssthresh < net->mtu) {
1047 net->ssthresh = net->mtu;
1048 }
1049 } else {
1050 net->ssthresh = max(net->cwnd / 2, 4 * net->mtu);
1051 }
1052 net->cwnd = net->mtu;
1053 net->partial_bytes_acked = 0;
1054 SDT_PROBE(sctp, cwnd, net, to,
1055 stcb->asoc.my_vtag,
1056 ((stcb->sctp_ep->sctp_lport << 16) | (stcb->rport)),
1057 net,
1058 old_cwnd, net->cwnd);
1059 if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_CWND_MONITOR_ENABLE) {
1060 sctp_log_cwnd(stcb, net, net->cwnd - old_cwnd, SCTP_CWND_LOG_FROM_RTX);
1061 }
1062 }
1063
1064 static void
1065 sctp_cwnd_update_after_ecn_echo_common(struct sctp_tcb *stcb, struct sctp_nets *net,
1066 int in_window, int num_pkt_lost, int use_rtcc)
1067 {
1068 int old_cwnd = net->cwnd;
1069
1070 if ((use_rtcc) && (net->lan_type == SCTP_LAN_LOCAL) && (net->cc_mod.rtcc.use_dccc_ecn)) {
1071 /* Data center Congestion Control */
1072 if (in_window == 0) {
1073 /*
1074 * Go to CA with the cwnd at the point we sent the
1075 * TSN that was marked with a CE.
1076 */
1077 if (net->ecn_prev_cwnd < net->cwnd) {
1078 /* Restore to prev cwnd */
1079 net->cwnd = net->ecn_prev_cwnd - (net->mtu * num_pkt_lost);
1080 } else {
1081 /* Just cut in 1/2 */
1082 net->cwnd /= 2;
1083 }
1084 /* Drop to CA */
1085 net->ssthresh = net->cwnd - (num_pkt_lost * net->mtu);
1086 if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_CWND_MONITOR_ENABLE) {
1087 sctp_log_cwnd(stcb, net, (net->cwnd - old_cwnd), SCTP_CWND_LOG_FROM_SAT);
1088 }
1089 } else {
1090 /*
1091 * Further tuning down required over the drastic
1092 * orginal cut
1093 */
1094 net->ssthresh -= (net->mtu * num_pkt_lost);
1095 net->cwnd -= (net->mtu * num_pkt_lost);
1096 if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_CWND_MONITOR_ENABLE) {
1097 sctp_log_cwnd(stcb, net, (net->cwnd - old_cwnd), SCTP_CWND_LOG_FROM_SAT);
1098 }
1099 }
1100 SCTP_STAT_INCR(sctps_ecnereducedcwnd);
1101 } else {
1102 if (in_window == 0) {
1103 SCTP_STAT_INCR(sctps_ecnereducedcwnd);
1104 net->ssthresh = net->cwnd / 2;
1105 if (net->ssthresh < net->mtu) {
1106 net->ssthresh = net->mtu;
1107 /*
1108 * here back off the timer as well, to slow
1109 * us down
1110 */
1111 net->RTO <<= 1;
1112 }
1113 net->cwnd = net->ssthresh;
1114 SDT_PROBE(sctp, cwnd, net, ecn,
1115 stcb->asoc.my_vtag,
1116 ((stcb->sctp_ep->sctp_lport << 16) | (stcb->rport)),
1117 net,
1118 old_cwnd, net->cwnd);
1119 if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_CWND_MONITOR_ENABLE) {
1120 sctp_log_cwnd(stcb, net, (net->cwnd - old_cwnd), SCTP_CWND_LOG_FROM_SAT);
1121 }
1122 }
1123 }
1124
1125 }
1126
1127 static void
1128 sctp_cwnd_update_after_packet_dropped(struct sctp_tcb *stcb,
1129 struct sctp_nets *net, struct sctp_pktdrop_chunk *cp,
1130 uint32_t * bottle_bw, uint32_t * on_queue)
1131 {
1132 uint32_t bw_avail;
1133 unsigned int incr;
1134 int old_cwnd = net->cwnd;
1135
1136 /* get bottle neck bw */
1137 *bottle_bw = ntohl(cp->bottle_bw);
1138 /* and whats on queue */
1139 *on_queue = ntohl(cp->current_onq);
1140 /*
1141 * adjust the on-queue if our flight is more it could be that the
1142 * router has not yet gotten data "in-flight" to it
1143 */
1144 if (*on_queue < net->flight_size) {
1145 *on_queue = net->flight_size;
1146 }
1147 /* rtt is measured in micro seconds, bottle_bw in bytes per second */
1148 bw_avail = (uint32_t) (((uint64_t) (*bottle_bw) * net->rtt) / (uint64_t) 1000000);
1149 if (bw_avail > *bottle_bw) {
1150 /*
1151 * Cap the growth to no more than the bottle neck. This can
1152 * happen as RTT slides up due to queues. It also means if
1153 * you have more than a 1 second RTT with a empty queue you
1154 * will be limited to the bottle_bw per second no matter if
1155 * other points have 1/2 the RTT and you could get more
1156 * out...
1157 */
1158 bw_avail = *bottle_bw;
1159 }
1160 if (*on_queue > bw_avail) {
1161 /*
1162 * No room for anything else don't allow anything else to be
1163 * "added to the fire".
1164 */
1165 int seg_inflight, seg_onqueue, my_portion;
1166
1167 net->partial_bytes_acked = 0;
1168 /* how much are we over queue size? */
1169 incr = *on_queue - bw_avail;
1170 if (stcb->asoc.seen_a_sack_this_pkt) {
1171 /*
1172 * undo any cwnd adjustment that the sack might have
1173 * made
1174 */
1175 net->cwnd = net->prev_cwnd;
1176 }
1177 /* Now how much of that is mine? */
1178 seg_inflight = net->flight_size / net->mtu;
1179 seg_onqueue = *on_queue / net->mtu;
1180 my_portion = (incr * seg_inflight) / seg_onqueue;
1181
1182 /* Have I made an adjustment already */
1183 if (net->cwnd > net->flight_size) {
1184 /*
1185 * for this flight I made an adjustment we need to
1186 * decrease the portion by a share our previous
1187 * adjustment.
1188 */
1189 int diff_adj;
1190
1191 diff_adj = net->cwnd - net->flight_size;
1192 if (diff_adj > my_portion)
1193 my_portion = 0;
1194 else
1195 my_portion -= diff_adj;
1196 }
1197 /*
1198 * back down to the previous cwnd (assume we have had a sack
1199 * before this packet). minus what ever portion of the
1200 * overage is my fault.
1201 */
1202 net->cwnd -= my_portion;
1203
1204 /* we will NOT back down more than 1 MTU */
1205 if (net->cwnd <= net->mtu) {
1206 net->cwnd = net->mtu;
1207 }
1208 /* force into CA */
1209 net->ssthresh = net->cwnd - 1;
1210 } else {
1211 /*
1212 * Take 1/4 of the space left or max burst up .. whichever
1213 * is less.
1214 */
1215 incr = (bw_avail - *on_queue) >> 2;
1216 if ((stcb->asoc.max_burst > 0) &&
1217 (stcb->asoc.max_burst * net->mtu < incr)) {
1218 incr = stcb->asoc.max_burst * net->mtu;
1219 }
1220 net->cwnd += incr;
1221 }
1222 if (net->cwnd > bw_avail) {
1223 /* We can't exceed the pipe size */
1224 net->cwnd = bw_avail;
1225 }
1226 if (net->cwnd < net->mtu) {
1227 /* We always have 1 MTU */
1228 net->cwnd = net->mtu;
1229 }
1230 if (net->cwnd - old_cwnd != 0) {
1231 /* log only changes */
1232 SDT_PROBE(sctp, cwnd, net, pd,
1233 stcb->asoc.my_vtag,
1234 ((stcb->sctp_ep->sctp_lport << 16) | (stcb->rport)),
1235 net,
1236 old_cwnd, net->cwnd);
1237 if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_CWND_MONITOR_ENABLE) {
1238 sctp_log_cwnd(stcb, net, (net->cwnd - old_cwnd),
1239 SCTP_CWND_LOG_FROM_SAT);
1240 }
1241 }
1242 }
1243
1244 static void
1245 sctp_cwnd_update_after_output(struct sctp_tcb *stcb,
1246 struct sctp_nets *net, int burst_limit)
1247 {
1248 int old_cwnd = net->cwnd;
1249
1250 if (net->ssthresh < net->cwnd)
1251 net->ssthresh = net->cwnd;
1252 if (burst_limit) {
1253 net->cwnd = (net->flight_size + (burst_limit * net->mtu));
1254 SDT_PROBE(sctp, cwnd, net, bl,
1255 stcb->asoc.my_vtag,
1256 ((stcb->sctp_ep->sctp_lport << 16) | (stcb->rport)),
1257 net,
1258 old_cwnd, net->cwnd);
1259 if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_CWND_MONITOR_ENABLE) {
1260 sctp_log_cwnd(stcb, net, (net->cwnd - old_cwnd), SCTP_CWND_LOG_FROM_BRST);
1261 }
1262 }
1263 }
1264
1265 static void
1266 sctp_cwnd_update_after_sack(struct sctp_tcb *stcb,
1267 struct sctp_association *asoc,
1268 int accum_moved, int reneged_all, int will_exit)
1269 {
1270 /* Passing a zero argument in last disables the rtcc algoritm */
1271 sctp_cwnd_update_after_sack_common(stcb, asoc, accum_moved, reneged_all, will_exit, 0);
1272 }
1273
1274 static void
1275 sctp_cwnd_update_after_ecn_echo(struct sctp_tcb *stcb, struct sctp_nets *net,
1276 int in_window, int num_pkt_lost)
1277 {
1278 /* Passing a zero argument in last disables the rtcc algoritm */
1279 sctp_cwnd_update_after_ecn_echo_common(stcb, net, in_window, num_pkt_lost, 0);
1280 }
1281
1282 /* Here starts the RTCCVAR type CC invented by RRS which
1283 * is a slight mod to RFC2581. We reuse a common routine or
1284 * two since these algoritms are so close and need to
1285 * remain the same.
1286 */
1287 static void
1288 sctp_cwnd_update_rtcc_after_ecn_echo(struct sctp_tcb *stcb, struct sctp_nets *net,
1289 int in_window, int num_pkt_lost)
1290 {
1291 sctp_cwnd_update_after_ecn_echo_common(stcb, net, in_window, num_pkt_lost, 1);
1292 }
1293
1294
1295 static
1296 void
1297 sctp_cwnd_update_rtcc_tsn_acknowledged(struct sctp_nets *net,
1298 struct sctp_tmit_chunk *tp1)
1299 {
1300 net->cc_mod.rtcc.bw_bytes += tp1->send_size;
1301 }
1302
1303 static void
1304 sctp_cwnd_prepare_rtcc_net_for_sack(struct sctp_tcb *stcb SCTP_UNUSED,
1305 struct sctp_nets *net)
1306 {
1307 if (net->cc_mod.rtcc.tls_needs_set > 0) {
1308 /* We had a bw measurment going on */
1309 struct timeval ltls;
1310
1311 SCTP_GETPTIME_TIMEVAL(<ls);
1312 timevalsub(<ls, &net->cc_mod.rtcc.tls);
1313 net->cc_mod.rtcc.new_tot_time = (ltls.tv_sec * 1000000) + ltls.tv_usec;
1314 }
1315 }
1316
1317 static void
1318 sctp_cwnd_new_rtcc_transmission_begins(struct sctp_tcb *stcb,
1319 struct sctp_nets *net)
1320 {
1321 uint64_t vtag, probepoint;
1322
1323 if (net->cc_mod.rtcc.lbw) {
1324 /* Clear the old bw.. we went to 0 in-flight */
1325 vtag = (net->rtt << 32) | (((uint32_t) (stcb->sctp_ep->sctp_lport)) << 16) |
1326 (stcb->rport);
1327 probepoint = (((uint64_t) net->cwnd) << 32);
1328 /* Probe point 8 */
1329 probepoint |= ((8 << 16) | 0);
1330 SDT_PROBE(sctp, cwnd, net, rttvar,
1331 vtag,
1332 ((net->cc_mod.rtcc.lbw << 32) | 0),
1333 ((net->cc_mod.rtcc.lbw_rtt << 32) | net->rtt),
1334 net->flight_size,
1335 probepoint);
1336 net->cc_mod.rtcc.lbw_rtt = 0;
1337 net->cc_mod.rtcc.cwnd_at_bw_set = 0;
1338 net->cc_mod.rtcc.lbw = 0;
1339 net->cc_mod.rtcc.bw_bytes_at_last_rttc = 0;
1340 net->cc_mod.rtcc.vol_reduce = 0;
1341 net->cc_mod.rtcc.bw_tot_time = 0;
1342 net->cc_mod.rtcc.bw_bytes = 0;
1343 net->cc_mod.rtcc.tls_needs_set = 0;
1344 if (net->cc_mod.rtcc.steady_step) {
1345 net->cc_mod.rtcc.vol_reduce = 0;
1346 net->cc_mod.rtcc.step_cnt = 0;
1347 net->cc_mod.rtcc.last_step_state = 0;
1348 }
1349 if (net->cc_mod.rtcc.ret_from_eq) {
1350 /* less aggressive one - reset cwnd too */
1351 uint32_t cwnd_in_mtu, cwnd;
1352
1353 cwnd_in_mtu = SCTP_BASE_SYSCTL(sctp_initial_cwnd);
1354 if (cwnd_in_mtu == 0) {
1355 /*
1356 * Using 0 means that the value of RFC 4960
1357 * is used.
1358 */
1359 cwnd = min((net->mtu * 4), max((2 * net->mtu), SCTP_INITIAL_CWND));
1360 } else {
1361 /*
1362 * We take the minimum of the burst limit
1363 * and the initial congestion window.
1364 */
1365 if ((stcb->asoc.max_burst > 0) && (cwnd_in_mtu > stcb->asoc.max_burst))
1366 cwnd_in_mtu = stcb->asoc.max_burst;
1367 cwnd = (net->mtu - sizeof(struct sctphdr)) * cwnd_in_mtu;
1368 }
1369 if (net->cwnd > cwnd) {
1370 /*
1371 * Only set if we are not a timeout (i.e.
1372 * down to 1 mtu)
1373 */
1374 net->cwnd = cwnd;
1375 }
1376 }
1377 }
1378 }
1379
1380 static void
1381 sctp_set_rtcc_initial_cc_param(struct sctp_tcb *stcb,
1382 struct sctp_nets *net)
1383 {
1384 uint64_t vtag, probepoint;
1385
1386 sctp_set_initial_cc_param(stcb, net);
1387 stcb->asoc.use_precise_time = 1;
1388 probepoint = (((uint64_t) net->cwnd) << 32);
1389 probepoint |= ((9 << 16) | 0);
1390 vtag = (net->rtt << 32) |
1391 (((uint32_t) (stcb->sctp_ep->sctp_lport)) << 16) |
1392 (stcb->rport);
1393 SDT_PROBE(sctp, cwnd, net, rttvar,
1394 vtag,
1395 0,
1396 0,
1397 0,
1398 probepoint);
1399 net->cc_mod.rtcc.lbw_rtt = 0;
1400 net->cc_mod.rtcc.cwnd_at_bw_set = 0;
1401 net->cc_mod.rtcc.vol_reduce = 0;
1402 net->cc_mod.rtcc.lbw = 0;
1403 net->cc_mod.rtcc.vol_reduce = 0;
1404 net->cc_mod.rtcc.bw_bytes_at_last_rttc = 0;
1405 net->cc_mod.rtcc.bw_tot_time = 0;
1406 net->cc_mod.rtcc.bw_bytes = 0;
1407 net->cc_mod.rtcc.tls_needs_set = 0;
1408 net->cc_mod.rtcc.ret_from_eq = SCTP_BASE_SYSCTL(sctp_rttvar_eqret);
1409 net->cc_mod.rtcc.steady_step = SCTP_BASE_SYSCTL(sctp_steady_step);
1410 net->cc_mod.rtcc.use_dccc_ecn = SCTP_BASE_SYSCTL(sctp_use_dccc_ecn);
1411 net->cc_mod.rtcc.step_cnt = 0;
1412 net->cc_mod.rtcc.last_step_state = 0;
1413
1414
1415 }
1416
1417 static int
1418 sctp_cwnd_rtcc_socket_option(struct sctp_tcb *stcb, int setorget,
1419 struct sctp_cc_option *cc_opt)
1420 {
1421 struct sctp_nets *net;
1422
1423 if (setorget == 1) {
1424 /* a set */
1425 if (cc_opt->option == SCTP_CC_OPT_RTCC_SETMODE) {
1426 if ((cc_opt->aid_value.assoc_value != 0) &&
1427 (cc_opt->aid_value.assoc_value != 1)) {
1428 return (EINVAL);
1429 }
1430 TAILQ_FOREACH(net, &stcb->asoc.nets, sctp_next) {
1431 net->cc_mod.rtcc.ret_from_eq = cc_opt->aid_value.assoc_value;
1432 }
1433 } else if (cc_opt->option == SCTP_CC_OPT_USE_DCCC_ECN) {
1434 if ((cc_opt->aid_value.assoc_value != 0) &&
1435 (cc_opt->aid_value.assoc_value != 1)) {
1436 return (EINVAL);
1437 }
1438 TAILQ_FOREACH(net, &stcb->asoc.nets, sctp_next) {
1439 net->cc_mod.rtcc.use_dccc_ecn = cc_opt->aid_value.assoc_value;
1440 }
1441 } else if (cc_opt->option == SCTP_CC_OPT_STEADY_STEP) {
1442 TAILQ_FOREACH(net, &stcb->asoc.nets, sctp_next) {
1443 net->cc_mod.rtcc.steady_step = cc_opt->aid_value.assoc_value;
1444 }
1445 } else {
1446 return (EINVAL);
1447 }
1448 } else {
1449 /* a get */
1450 if (cc_opt->option == SCTP_CC_OPT_RTCC_SETMODE) {
1451 net = TAILQ_FIRST(&stcb->asoc.nets);
1452 if (net == NULL) {
1453 return (EFAULT);
1454 }
1455 cc_opt->aid_value.assoc_value = net->cc_mod.rtcc.ret_from_eq;
1456 } else if (cc_opt->option == SCTP_CC_OPT_USE_DCCC_ECN) {
1457 net = TAILQ_FIRST(&stcb->asoc.nets);
1458 if (net == NULL) {
1459 return (EFAULT);
1460 }
1461 cc_opt->aid_value.assoc_value = net->cc_mod.rtcc.use_dccc_ecn;
1462 } else if (cc_opt->option == SCTP_CC_OPT_STEADY_STEP) {
1463 net = TAILQ_FIRST(&stcb->asoc.nets);
1464 if (net == NULL) {
1465 return (EFAULT);
1466 }
1467 cc_opt->aid_value.assoc_value = net->cc_mod.rtcc.steady_step;
1468 } else {
1469 return (EINVAL);
1470 }
1471 }
1472 return (0);
1473 }
1474
1475 static void
1476 sctp_cwnd_update_rtcc_packet_transmitted(struct sctp_tcb *stcb SCTP_UNUSED,
1477 struct sctp_nets *net)
1478 {
1479 if (net->cc_mod.rtcc.tls_needs_set == 0) {
1480 SCTP_GETPTIME_TIMEVAL(&net->cc_mod.rtcc.tls);
1481 net->cc_mod.rtcc.tls_needs_set = 2;
1482 }
1483 }
1484
1485 static void
1486 sctp_cwnd_update_rtcc_after_sack(struct sctp_tcb *stcb,
1487 struct sctp_association *asoc,
1488 int accum_moved, int reneged_all, int will_exit)
1489 {
1490 /* Passing a one argument at the last enables the rtcc algoritm */
1491 sctp_cwnd_update_after_sack_common(stcb, asoc, accum_moved, reneged_all, will_exit, 1);
1492 }
1493
1494 static void
1495 sctp_rtt_rtcc_calculated(struct sctp_tcb *stcb SCTP_UNUSED,
1496 struct sctp_nets *net,
1497 struct timeval *now SCTP_UNUSED)
1498 {
1499 net->cc_mod.rtcc.rtt_set_this_sack = 1;
1500 }
1501
1502 /* Here starts Sally Floyds HS-TCP */
1503
1504 struct sctp_hs_raise_drop {
1505 int32_t cwnd;
1506 int32_t increase;
1507 int32_t drop_percent;
1508 };
1509
1510 #define SCTP_HS_TABLE_SIZE 73
1511
1512 struct sctp_hs_raise_drop sctp_cwnd_adjust[SCTP_HS_TABLE_SIZE] = {
1513 {38, 1, 50}, /* 0 */
1514 {118, 2, 44}, /* 1 */
1515 {221, 3, 41}, /* 2 */
1516 {347, 4, 38}, /* 3 */
1517 {495, 5, 37}, /* 4 */
1518 {663, 6, 35}, /* 5 */
1519 {851, 7, 34}, /* 6 */
1520 {1058, 8, 33}, /* 7 */
1521 {1284, 9, 32}, /* 8 */
1522 {1529, 10, 31}, /* 9 */
1523 {1793, 11, 30}, /* 10 */
1524 {2076, 12, 29}, /* 11 */
1525 {2378, 13, 28}, /* 12 */
1526 {2699, 14, 28}, /* 13 */
1527 {3039, 15, 27}, /* 14 */
1528 {3399, 16, 27}, /* 15 */
1529 {3778, 17, 26}, /* 16 */
1530 {4177, 18, 26}, /* 17 */
1531 {4596, 19, 25}, /* 18 */
1532 {5036, 20, 25}, /* 19 */
1533 {5497, 21, 24}, /* 20 */
1534 {5979, 22, 24}, /* 21 */
1535 {6483, 23, 23}, /* 22 */
1536 {7009, 24, 23}, /* 23 */
1537 {7558, 25, 22}, /* 24 */
1538 {8130, 26, 22}, /* 25 */
1539 {8726, 27, 22}, /* 26 */
1540 {9346, 28, 21}, /* 27 */
1541 {9991, 29, 21}, /* 28 */
1542 {10661, 30, 21}, /* 29 */
1543 {11358, 31, 20}, /* 30 */
1544 {12082, 32, 20}, /* 31 */
1545 {12834, 33, 20}, /* 32 */
1546 {13614, 34, 19}, /* 33 */
1547 {14424, 35, 19}, /* 34 */
1548 {15265, 36, 19}, /* 35 */
1549 {16137, 37, 19}, /* 36 */
1550 {17042, 38, 18}, /* 37 */
1551 {17981, 39, 18}, /* 38 */
1552 {18955, 40, 18}, /* 39 */
1553 {19965, 41, 17}, /* 40 */
1554 {21013, 42, 17}, /* 41 */
1555 {22101, 43, 17}, /* 42 */
1556 {23230, 44, 17}, /* 43 */
1557 {24402, 45, 16}, /* 44 */
1558 {25618, 46, 16}, /* 45 */
1559 {26881, 47, 16}, /* 46 */
1560 {28193, 48, 16}, /* 47 */
1561 {29557, 49, 15}, /* 48 */
1562 {30975, 50, 15}, /* 49 */
1563 {32450, 51, 15}, /* 50 */
1564 {33986, 52, 15}, /* 51 */
1565 {35586, 53, 14}, /* 52 */
1566 {37253, 54, 14}, /* 53 */
1567 {38992, 55, 14}, /* 54 */
1568 {40808, 56, 14}, /* 55 */
1569 {42707, 57, 13}, /* 56 */
1570 {44694, 58, 13}, /* 57 */
1571 {46776, 59, 13}, /* 58 */
1572 {48961, 60, 13}, /* 59 */
1573 {51258, 61, 13}, /* 60 */
1574 {53677, 62, 12}, /* 61 */
1575 {56230, 63, 12}, /* 62 */
1576 {58932, 64, 12}, /* 63 */
1577 {61799, 65, 12}, /* 64 */
1578 {64851, 66, 11}, /* 65 */
1579 {68113, 67, 11}, /* 66 */
1580 {71617, 68, 11}, /* 67 */
1581 {75401, 69, 10}, /* 68 */
1582 {79517, 70, 10}, /* 69 */
1583 {84035, 71, 10}, /* 70 */
1584 {89053, 72, 10}, /* 71 */
1585 {94717, 73, 9} /* 72 */
1586 };
1587
1588 static void
1589 sctp_hs_cwnd_increase(struct sctp_tcb *stcb, struct sctp_nets *net)
1590 {
1591 int cur_val, i, indx, incr;
1592
1593 cur_val = net->cwnd >> 10;
1594 indx = SCTP_HS_TABLE_SIZE - 1;
1595
1596 if (cur_val < sctp_cwnd_adjust[0].cwnd) {
1597 /* normal mode */
1598 if (net->net_ack > net->mtu) {
1599 net->cwnd += net->mtu;
1600 if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_CWND_MONITOR_ENABLE) {
1601 sctp_log_cwnd(stcb, net, net->mtu, SCTP_CWND_LOG_FROM_SS);
1602 }
1603 } else {
1604 net->cwnd += net->net_ack;
1605 if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_CWND_MONITOR_ENABLE) {
1606 sctp_log_cwnd(stcb, net, net->net_ack, SCTP_CWND_LOG_FROM_SS);
1607 }
1608 }
1609 } else {
1610 for (i = net->last_hs_used; i < SCTP_HS_TABLE_SIZE; i++) {
1611 if (cur_val < sctp_cwnd_adjust[i].cwnd) {
1612 indx = i;
1613 break;
1614 }
1615 }
1616 net->last_hs_used = indx;
1617 incr = ((sctp_cwnd_adjust[indx].increase) << 10);
1618 net->cwnd += incr;
1619 if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_CWND_MONITOR_ENABLE) {
1620 sctp_log_cwnd(stcb, net, incr, SCTP_CWND_LOG_FROM_SS);
1621 }
1622 }
1623 }
1624
1625 static void
1626 sctp_hs_cwnd_decrease(struct sctp_tcb *stcb, struct sctp_nets *net)
1627 {
1628 int cur_val, i, indx;
1629 int old_cwnd = net->cwnd;
1630
1631 cur_val = net->cwnd >> 10;
1632 if (cur_val < sctp_cwnd_adjust[0].cwnd) {
1633 /* normal mode */
1634 net->ssthresh = net->cwnd / 2;
1635 if (net->ssthresh < (net->mtu * 2)) {
1636 net->ssthresh = 2 * net->mtu;
1637 }
1638 net->cwnd = net->ssthresh;
1639 } else {
1640 /* drop by the proper amount */
1641 net->ssthresh = net->cwnd - (int)((net->cwnd / 100) *
1642 sctp_cwnd_adjust[net->last_hs_used].drop_percent);
1643 net->cwnd = net->ssthresh;
1644 /* now where are we */
1645 indx = net->last_hs_used;
1646 cur_val = net->cwnd >> 10;
1647 /* reset where we are in the table */
1648 if (cur_val < sctp_cwnd_adjust[0].cwnd) {
1649 /* feel out of hs */
1650 net->last_hs_used = 0;
1651 } else {
1652 for (i = indx; i >= 1; i--) {
1653 if (cur_val > sctp_cwnd_adjust[i - 1].cwnd) {
1654 break;
1655 }
1656 }
1657 net->last_hs_used = indx;
1658 }
1659 }
1660 if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_CWND_MONITOR_ENABLE) {
1661 sctp_log_cwnd(stcb, net, (net->cwnd - old_cwnd), SCTP_CWND_LOG_FROM_FR);
1662 }
1663 }
1664
1665 static void
1666 sctp_hs_cwnd_update_after_fr(struct sctp_tcb *stcb,
1667 struct sctp_association *asoc)
1668 {
1669 struct sctp_nets *net;
1670
1671 /*
1672 * CMT fast recovery code. Need to debug. ((sctp_cmt_on_off > 0) &&
1673 * (net->fast_retran_loss_recovery == 0)))
1674 */
1675 TAILQ_FOREACH(net, &asoc->nets, sctp_next) {
1676 if ((asoc->fast_retran_loss_recovery == 0) ||
1677 (asoc->sctp_cmt_on_off > 0)) {
1678 /* out of a RFC2582 Fast recovery window? */
1679 if (net->net_ack > 0) {
1680 /*
1681 * per section 7.2.3, are there any
1682 * destinations that had a fast retransmit
1683 * to them. If so what we need to do is
1684 * adjust ssthresh and cwnd.
1685 */
1686 struct sctp_tmit_chunk *lchk;
1687
1688 sctp_hs_cwnd_decrease(stcb, net);
1689
1690 lchk = TAILQ_FIRST(&asoc->send_queue);
1691
1692 net->partial_bytes_acked = 0;
1693 /* Turn on fast recovery window */
1694 asoc->fast_retran_loss_recovery = 1;
1695 if (lchk == NULL) {
1696 /* Mark end of the window */
1697 asoc->fast_recovery_tsn = asoc->sending_seq - 1;
1698 } else {
1699 asoc->fast_recovery_tsn = lchk->rec.data.TSN_seq - 1;
1700 }
1701
1702 /*
1703 * CMT fast recovery -- per destination
1704 * recovery variable.
1705 */
1706 net->fast_retran_loss_recovery = 1;
1707
1708 if (lchk == NULL) {
1709 /* Mark end of the window */
1710 net->fast_recovery_tsn = asoc->sending_seq - 1;
1711 } else {
1712 net->fast_recovery_tsn = lchk->rec.data.TSN_seq - 1;
1713 }
1714
1715 sctp_timer_stop(SCTP_TIMER_TYPE_SEND,
1716 stcb->sctp_ep, stcb, net, SCTP_FROM_SCTP_INDATA + SCTP_LOC_32);
1717 sctp_timer_start(SCTP_TIMER_TYPE_SEND,
1718 stcb->sctp_ep, stcb, net);
1719 }
1720 } else if (net->net_ack > 0) {
1721 /*
1722 * Mark a peg that we WOULD have done a cwnd
1723 * reduction but RFC2582 prevented this action.
1724 */
1725 SCTP_STAT_INCR(sctps_fastretransinrtt);
1726 }
1727 }
1728 }
1729
1730 static void
1731 sctp_hs_cwnd_update_after_sack(struct sctp_tcb *stcb,
1732 struct sctp_association *asoc,
1733 int accum_moved, int reneged_all SCTP_UNUSED, int will_exit)
1734 {
1735 struct sctp_nets *net;
1736
1737 /******************************/
1738 /* update cwnd and Early FR */
1739 /******************************/
1740 TAILQ_FOREACH(net, &asoc->nets, sctp_next) {
1741
1742 #ifdef JANA_CMT_FAST_RECOVERY
1743 /*
1744 * CMT fast recovery code. Need to debug.
1745 */
1746 if (net->fast_retran_loss_recovery && net->new_pseudo_cumack) {
1747 if (SCTP_TSN_GE(asoc->last_acked_seq, net->fast_recovery_tsn) ||
1748 SCTP_TSN_GE(net->pseudo_cumack, net->fast_recovery_tsn)) {
1749 net->will_exit_fast_recovery = 1;
1750 }
1751 }
1752 #endif
1753 /* if nothing was acked on this destination skip it */
1754 if (net->net_ack == 0) {
1755 if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_CWND_LOGGING_ENABLE) {
1756 sctp_log_cwnd(stcb, net, 0, SCTP_CWND_LOG_FROM_SACK);
1757 }
1758 continue;
1759 }
1760 #ifdef JANA_CMT_FAST_RECOVERY
1761 /*
1762 * CMT fast recovery code
1763 */
1764 /*
1765 * if (sctp_cmt_on_off > 0 && net->fast_retran_loss_recovery
1766 * && net->will_exit_fast_recovery == 0) { @@@ Do something
1767 * } else if (sctp_cmt_on_off == 0 &&
1768 * asoc->fast_retran_loss_recovery && will_exit == 0) {
1769 */
1770 #endif
1771
1772 if (asoc->fast_retran_loss_recovery &&
1773 (will_exit == 0) &&
1774 (asoc->sctp_cmt_on_off == 0)) {
1775 /*
1776 * If we are in loss recovery we skip any cwnd
1777 * update
1778 */
1779 return;
1780 }
1781 /*
1782 * CMT: CUC algorithm. Update cwnd if pseudo-cumack has
1783 * moved.
1784 */
1785 if (accum_moved ||
1786 ((asoc->sctp_cmt_on_off > 0) && net->new_pseudo_cumack)) {
1787 /* If the cumulative ack moved we can proceed */
1788 if (net->cwnd <= net->ssthresh) {
1789 /* We are in slow start */
1790 if (net->flight_size + net->net_ack >= net->cwnd) {
1791
1792 sctp_hs_cwnd_increase(stcb, net);
1793
1794 } else {
1795 if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_CWND_LOGGING_ENABLE) {
1796 sctp_log_cwnd(stcb, net, net->net_ack,
1797 SCTP_CWND_LOG_NOADV_SS);
1798 }
1799 }
1800 } else {
1801 /* We are in congestion avoidance */
1802 net->partial_bytes_acked += net->net_ack;
1803 if ((net->flight_size + net->net_ack >= net->cwnd) &&
1804 (net->partial_bytes_acked >= net->cwnd)) {
1805 net->partial_bytes_acked -= net->cwnd;
1806 net->cwnd += net->mtu;
1807 if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_CWND_MONITOR_ENABLE) {
1808 sctp_log_cwnd(stcb, net, net->mtu,
1809 SCTP_CWND_LOG_FROM_CA);
1810 }
1811 } else {
1812 if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_CWND_LOGGING_ENABLE) {
1813 sctp_log_cwnd(stcb, net, net->net_ack,
1814 SCTP_CWND_LOG_NOADV_CA);
1815 }
1816 }
1817 }
1818 } else {
1819 if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_CWND_LOGGING_ENABLE) {
1820 sctp_log_cwnd(stcb, net, net->mtu,
1821 SCTP_CWND_LOG_NO_CUMACK);
1822 }
1823 }
1824 }
1825 }
1826
1827
1828 /*
1829 * H-TCP congestion control. The algorithm is detailed in:
1830 * R.N.Shorten, D.J.Leith:
1831 * "H-TCP: TCP for high-speed and long-distance networks"
1832 * Proc. PFLDnet, Argonne, 2004.
1833 * http://www.hamilton.ie/net/htcp3.pdf
1834 */
1835
1836
1837 static int use_rtt_scaling = 1;
1838 static int use_bandwidth_switch = 1;
1839
1840 static inline int
1841 between(uint32_t seq1, uint32_t seq2, uint32_t seq3)
1842 {
1843 return (seq3 - seq2 >= seq1 - seq2);
1844 }
1845
1846 static inline uint32_t
1847 htcp_cong_time(struct htcp *ca)
1848 {
1849 return (sctp_get_tick_count() - ca->last_cong);
1850 }
1851
1852 static inline uint32_t
1853 htcp_ccount(struct htcp *ca)
1854 {
1855 return (htcp_cong_time(ca) / ca->minRTT);
1856 }
1857
1858 static inline void
1859 htcp_reset(struct htcp *ca)
1860 {
1861 ca->undo_last_cong = ca->last_cong;
1862 ca->undo_maxRTT = ca->maxRTT;
1863 ca->undo_old_maxB = ca->old_maxB;
1864 ca->last_cong = sctp_get_tick_count();
1865 }
1866
1867 #ifdef SCTP_NOT_USED
1868
1869 static uint32_t
1870 htcp_cwnd_undo(struct sctp_tcb *stcb, struct sctp_nets *net)
1871 {
1872 net->cc_mod.htcp_ca.last_cong = net->cc_mod.htcp_ca.undo_last_cong;
1873 net->cc_mod.htcp_ca.maxRTT = net->cc_mod.htcp_ca.undo_maxRTT;
1874 net->cc_mod.htcp_ca.old_maxB = net->cc_mod.htcp_ca.undo_old_maxB;
1875 return (max(net->cwnd, ((net->ssthresh / net->mtu << 7) / net->cc_mod.htcp_ca.beta) * net->mtu));
1876 }
1877
1878 #endif
1879
1880 static inline void
1881 measure_rtt(struct sctp_nets *net)
1882 {
1883 uint32_t srtt = net->lastsa >> SCTP_RTT_SHIFT;
1884
1885 /* keep track of minimum RTT seen so far, minRTT is zero at first */
1886 if (net->cc_mod.htcp_ca.minRTT > srtt || !net->cc_mod.htcp_ca.minRTT)
1887 net->cc_mod.htcp_ca.minRTT = srtt;
1888
1889 /* max RTT */
1890 if (net->fast_retran_ip == 0 && net->ssthresh < 0xFFFF && htcp_ccount(&net->cc_mod.htcp_ca) > 3) {
1891 if (net->cc_mod.htcp_ca.maxRTT < net->cc_mod.htcp_ca.minRTT)
1892 net->cc_mod.htcp_ca.maxRTT = net->cc_mod.htcp_ca.minRTT;
1893 if (net->cc_mod.htcp_ca.maxRTT < srtt && srtt <= net->cc_mod.htcp_ca.maxRTT + MSEC_TO_TICKS(20))
1894 net->cc_mod.htcp_ca.maxRTT = srtt;
1895 }
1896 }
1897
1898 static void
1899 measure_achieved_throughput(struct sctp_nets *net)
1900 {
1901 uint32_t now = sctp_get_tick_count();
1902
1903 if (net->fast_retran_ip == 0)
1904 net->cc_mod.htcp_ca.bytes_acked = net->net_ack;
1905
1906 if (!use_bandwidth_switch)
1907 return;
1908
1909 /* achieved throughput calculations */
1910 /* JRS - not 100% sure of this statement */
1911 if (net->fast_retran_ip == 1) {
1912 net->cc_mod.htcp_ca.bytecount = 0;
1913 net->cc_mod.htcp_ca.lasttime = now;
1914 return;
1915 }
1916 net->cc_mod.htcp_ca.bytecount += net->net_ack;
1917 if ((net->cc_mod.htcp_ca.bytecount >= net->cwnd - (((net->cc_mod.htcp_ca.alpha >> 7) ? (net->cc_mod.htcp_ca.alpha >> 7) : 1) * net->mtu)) &&
1918 (now - net->cc_mod.htcp_ca.lasttime >= net->cc_mod.htcp_ca.minRTT) &&
1919 (net->cc_mod.htcp_ca.minRTT > 0)) {
1920 uint32_t cur_Bi = net->cc_mod.htcp_ca.bytecount / net->mtu * hz / (now - net->cc_mod.htcp_ca.lasttime);
1921
1922 if (htcp_ccount(&net->cc_mod.htcp_ca) <= 3) {
1923 /* just after backoff */
1924 net->cc_mod.htcp_ca.minB = net->cc_mod.htcp_ca.maxB = net->cc_mod.htcp_ca.Bi = cur_Bi;
1925 } else {
1926 net->cc_mod.htcp_ca.Bi = (3 * net->cc_mod.htcp_ca.Bi + cur_Bi) / 4;
1927 if (net->cc_mod.htcp_ca.Bi > net->cc_mod.htcp_ca.maxB)
1928 net->cc_mod.htcp_ca.maxB = net->cc_mod.htcp_ca.Bi;
1929 if (net->cc_mod.htcp_ca.minB > net->cc_mod.htcp_ca.maxB)
1930 net->cc_mod.htcp_ca.minB = net->cc_mod.htcp_ca.maxB;
1931 }
1932 net->cc_mod.htcp_ca.bytecount = 0;
1933 net->cc_mod.htcp_ca.lasttime = now;
1934 }
1935 }
1936
1937 static inline void
1938 htcp_beta_update(struct htcp *ca, uint32_t minRTT, uint32_t maxRTT)
1939 {
1940 if (use_bandwidth_switch) {
1941 uint32_t maxB = ca->maxB;
1942 uint32_t old_maxB = ca->old_maxB;
1943
1944 ca->old_maxB = ca->maxB;
1945
1946 if (!between(5 * maxB, 4 * old_maxB, 6 * old_maxB)) {
1947 ca->beta = BETA_MIN;
1948 ca->modeswitch = 0;
1949 return;
1950 }
1951 }
1952 if (ca->modeswitch && minRTT > (uint32_t) MSEC_TO_TICKS(10) && maxRTT) {
1953 ca->beta = (minRTT << 7) / maxRTT;
1954 if (ca->beta < BETA_MIN)
1955 ca->beta = BETA_MIN;
1956 else if (ca->beta > BETA_MAX)
1957 ca->beta = BETA_MAX;
1958 } else {
1959 ca->beta = BETA_MIN;
1960 ca->modeswitch = 1;
1961 }
1962 }
1963
1964 static inline void
1965 htcp_alpha_update(struct htcp *ca)
1966 {
1967 uint32_t minRTT = ca->minRTT;
1968 uint32_t factor = 1;
1969 uint32_t diff = htcp_cong_time(ca);
1970
1971 if (diff > (uint32_t) hz) {
1972 diff -= hz;
1973 factor = 1 + (10 * diff + ((diff / 2) * (diff / 2) / hz)) / hz;
1974 }
1975 if (use_rtt_scaling && minRTT) {
1976 uint32_t scale = (hz << 3) / (10 * minRTT);
1977
1978 scale = min(max(scale, 1U << 2), 10U << 3); /* clamping ratio to
1979 * interval [0.5,10]<<3 */
1980 factor = (factor << 3) / scale;
1981 if (!factor)
1982 factor = 1;
1983 }
1984 ca->alpha = 2 * factor * ((1 << 7) - ca->beta);
1985 if (!ca->alpha)
1986 ca->alpha = ALPHA_BASE;
1987 }
1988
1989 /* After we have the rtt data to calculate beta, we'd still prefer to wait one
1990 * rtt before we adjust our beta to ensure we are working from a consistent
1991 * data.
1992 *
1993 * This function should be called when we hit a congestion event since only at
1994 * that point do we really have a real sense of maxRTT (the queues en route
1995 * were getting just too full now).
1996 */
1997 static void
1998 htcp_param_update(struct sctp_nets *net)
1999 {
2000 uint32_t minRTT = net->cc_mod.htcp_ca.minRTT;
2001 uint32_t maxRTT = net->cc_mod.htcp_ca.maxRTT;
2002
2003 htcp_beta_update(&net->cc_mod.htcp_ca, minRTT, maxRTT);
2004 htcp_alpha_update(&net->cc_mod.htcp_ca);
2005
2006 /*
2007 * add slowly fading memory for maxRTT to accommodate routing
2008 * changes etc
2009 */
2010 if (minRTT > 0 && maxRTT > minRTT)
2011 net->cc_mod.htcp_ca.maxRTT = minRTT + ((maxRTT - minRTT) * 95) / 100;
2012 }
2013
2014 static uint32_t
2015 htcp_recalc_ssthresh(struct sctp_nets *net)
2016 {
2017 htcp_param_update(net);
2018 return (max(((net->cwnd / net->mtu * net->cc_mod.htcp_ca.beta) >> 7) * net->mtu, 2U * net->mtu));
2019 }
2020
2021 static void
2022 htcp_cong_avoid(struct sctp_tcb *stcb, struct sctp_nets *net)
2023 {
2024 /*-
2025 * How to handle these functions?
2026 * if (!tcp_is_cwnd_limited(sk, in_flight)) RRS - good question.
2027 * return;
2028 */
2029 if (net->cwnd <= net->ssthresh) {
2030 /* We are in slow start */
2031 if (net->flight_size + net->net_ack >= net->cwnd) {
2032 if (net->net_ack > (net->mtu * SCTP_BASE_SYSCTL(sctp_L2_abc_variable))) {
2033 net->cwnd += (net->mtu * SCTP_BASE_SYSCTL(sctp_L2_abc_variable));
2034 if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_CWND_MONITOR_ENABLE) {
2035 sctp_log_cwnd(stcb, net, net->mtu,
2036 SCTP_CWND_LOG_FROM_SS);
2037 }
2038 } else {
2039 net->cwnd += net->net_ack;
2040 if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_CWND_MONITOR_ENABLE) {
2041 sctp_log_cwnd(stcb, net, net->net_ack,
2042 SCTP_CWND_LOG_FROM_SS);
2043 }
2044 }
2045 } else {
2046 if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_CWND_LOGGING_ENABLE) {
2047 sctp_log_cwnd(stcb, net, net->net_ack,
2048 SCTP_CWND_LOG_NOADV_SS);
2049 }
2050 }
2051 } else {
2052 measure_rtt(net);
2053
2054 /*
2055 * In dangerous area, increase slowly. In theory this is
2056 * net->cwnd += alpha / net->cwnd
2057 */
2058 /* What is snd_cwnd_cnt?? */
2059 if (((net->partial_bytes_acked / net->mtu * net->cc_mod.htcp_ca.alpha) >> 7) * net->mtu >= net->cwnd) {
2060 /*-
2061 * Does SCTP have a cwnd clamp?
2062 * if (net->snd_cwnd < net->snd_cwnd_clamp) - Nope (RRS).
2063 */
2064 net->cwnd += net->mtu;
2065 net->partial_bytes_acked = 0;
2066 htcp_alpha_update(&net->cc_mod.htcp_ca);
2067 if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_CWND_MONITOR_ENABLE) {
2068 sctp_log_cwnd(stcb, net, net->mtu,
2069 SCTP_CWND_LOG_FROM_CA);
2070 }
2071 } else {
2072 net->partial_bytes_acked += net->net_ack;
2073 if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_CWND_LOGGING_ENABLE) {
2074 sctp_log_cwnd(stcb, net, net->net_ack,
2075 SCTP_CWND_LOG_NOADV_CA);
2076 }
2077 }
2078
2079 net->cc_mod.htcp_ca.bytes_acked = net->mtu;
2080 }
2081 }
2082
2083 #ifdef SCTP_NOT_USED
2084 /* Lower bound on congestion window. */
2085 static uint32_t
2086 htcp_min_cwnd(struct sctp_tcb *stcb, struct sctp_nets *net)
2087 {
2088 return (net->ssthresh);
2089 }
2090
2091 #endif
2092
2093 static void
2094 htcp_init(struct sctp_nets *net)
2095 {
2096 memset(&net->cc_mod.htcp_ca, 0, sizeof(struct htcp));
2097 net->cc_mod.htcp_ca.alpha = ALPHA_BASE;
2098 net->cc_mod.htcp_ca.beta = BETA_MIN;
2099 net->cc_mod.htcp_ca.bytes_acked = net->mtu;
2100 net->cc_mod.htcp_ca.last_cong = sctp_get_tick_count();
2101 }
2102
2103 static void
2104 sctp_htcp_set_initial_cc_param(struct sctp_tcb *stcb, struct sctp_nets *net)
2105 {
2106 /*
2107 * We take the max of the burst limit times a MTU or the
2108 * INITIAL_CWND. We then limit this to 4 MTU's of sending.
2109 */
2110 net->cwnd = min((net->mtu * 4), max((2 * net->mtu), SCTP_INITIAL_CWND));
2111 net->ssthresh = stcb->asoc.peers_rwnd;
2112 htcp_init(net);
2113
2114 if (SCTP_BASE_SYSCTL(sctp_logging_level) & (SCTP_CWND_MONITOR_ENABLE | SCTP_CWND_LOGGING_ENABLE)) {
2115 sctp_log_cwnd(stcb, net, 0, SCTP_CWND_INITIALIZATION);
2116 }
2117 }
2118
2119 static void
2120 sctp_htcp_cwnd_update_after_sack(struct sctp_tcb *stcb,
2121 struct sctp_association *asoc,
2122 int accum_moved, int reneged_all SCTP_UNUSED, int will_exit)
2123 {
2124 struct sctp_nets *net;
2125
2126 /******************************/
2127 /* update cwnd and Early FR */
2128 /******************************/
2129 TAILQ_FOREACH(net, &asoc->nets, sctp_next) {
2130
2131 #ifdef JANA_CMT_FAST_RECOVERY
2132 /*
2133 * CMT fast recovery code. Need to debug.
2134 */
2135 if (net->fast_retran_loss_recovery && net->new_pseudo_cumack) {
2136 if (SCTP_TSN_GE(asoc->last_acked_seq, net->fast_recovery_tsn) ||
2137 SCTP_TSN_GE(net->pseudo_cumack, net->fast_recovery_tsn)) {
2138 net->will_exit_fast_recovery = 1;
2139 }
2140 }
2141 #endif
2142 /* if nothing was acked on this destination skip it */
2143 if (net->net_ack == 0) {
2144 if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_CWND_LOGGING_ENABLE) {
2145 sctp_log_cwnd(stcb, net, 0, SCTP_CWND_LOG_FROM_SACK);
2146 }
2147 continue;
2148 }
2149 #ifdef JANA_CMT_FAST_RECOVERY
2150 /*
2151 * CMT fast recovery code
2152 */
2153 /*
2154 * if (sctp_cmt_on_off > 0 && net->fast_retran_loss_recovery
2155 * && net->will_exit_fast_recovery == 0) { @@@ Do something
2156 * } else if (sctp_cmt_on_off == 0 &&
2157 * asoc->fast_retran_loss_recovery && will_exit == 0) {
2158 */
2159 #endif
2160
2161 if (asoc->fast_retran_loss_recovery &&
2162 will_exit == 0 &&
2163 (asoc->sctp_cmt_on_off == 0)) {
2164 /*
2165 * If we are in loss recovery we skip any cwnd
2166 * update
2167 */
2168 return;
2169 }
2170 /*
2171 * CMT: CUC algorithm. Update cwnd if pseudo-cumack has
2172 * moved.
2173 */
2174 if (accum_moved ||
2175 ((asoc->sctp_cmt_on_off > 0) && net->new_pseudo_cumack)) {
2176 htcp_cong_avoid(stcb, net);
2177 measure_achieved_throughput(net);
2178 } else {
2179 if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_CWND_LOGGING_ENABLE) {
2180 sctp_log_cwnd(stcb, net, net->mtu,
2181 SCTP_CWND_LOG_NO_CUMACK);
2182 }
2183 }
2184 }
2185 }
2186
2187 static void
2188 sctp_htcp_cwnd_update_after_fr(struct sctp_tcb *stcb,
2189 struct sctp_association *asoc)
2190 {
2191 struct sctp_nets *net;
2192
2193 /*
2194 * CMT fast recovery code. Need to debug. ((sctp_cmt_on_off > 0) &&
2195 * (net->fast_retran_loss_recovery == 0)))
2196 */
2197 TAILQ_FOREACH(net, &asoc->nets, sctp_next) {
2198 if ((asoc->fast_retran_loss_recovery == 0) ||
2199 (asoc->sctp_cmt_on_off > 0)) {
2200 /* out of a RFC2582 Fast recovery window? */
2201 if (net->net_ack > 0) {
2202 /*
2203 * per section 7.2.3, are there any
2204 * destinations that had a fast retransmit
2205 * to them. If so what we need to do is
2206 * adjust ssthresh and cwnd.
2207 */
2208 struct sctp_tmit_chunk *lchk;
2209 int old_cwnd = net->cwnd;
2210
2211 /* JRS - reset as if state were changed */
2212 htcp_reset(&net->cc_mod.htcp_ca);
2213 net->ssthresh = htcp_recalc_ssthresh(net);
2214 net->cwnd = net->ssthresh;
2215 if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_CWND_MONITOR_ENABLE) {
2216 sctp_log_cwnd(stcb, net, (net->cwnd - old_cwnd),
2217 SCTP_CWND_LOG_FROM_FR);
2218 }
2219 lchk = TAILQ_FIRST(&asoc->send_queue);
2220
2221 net->partial_bytes_acked = 0;
2222 /* Turn on fast recovery window */
2223 asoc->fast_retran_loss_recovery = 1;
2224 if (lchk == NULL) {
2225 /* Mark end of the window */
2226 asoc->fast_recovery_tsn = asoc->sending_seq - 1;
2227 } else {
2228 asoc->fast_recovery_tsn = lchk->rec.data.TSN_seq - 1;
2229 }
2230
2231 /*
2232 * CMT fast recovery -- per destination
2233 * recovery variable.
2234 */
2235 net->fast_retran_loss_recovery = 1;
2236
2237 if (lchk == NULL) {
2238 /* Mark end of the window */
2239 net->fast_recovery_tsn = asoc->sending_seq - 1;
2240 } else {
2241 net->fast_recovery_tsn = lchk->rec.data.TSN_seq - 1;
2242 }
2243
2244 sctp_timer_stop(SCTP_TIMER_TYPE_SEND,
2245 stcb->sctp_ep, stcb, net, SCTP_FROM_SCTP_INDATA + SCTP_LOC_32);
2246 sctp_timer_start(SCTP_TIMER_TYPE_SEND,
2247 stcb->sctp_ep, stcb, net);
2248 }
2249 } else if (net->net_ack > 0) {
2250 /*
2251 * Mark a peg that we WOULD have done a cwnd
2252 * reduction but RFC2582 prevented this action.
2253 */
2254 SCTP_STAT_INCR(sctps_fastretransinrtt);
2255 }
2256 }
2257 }
2258
2259 static void
2260 sctp_htcp_cwnd_update_after_timeout(struct sctp_tcb *stcb,
2261 struct sctp_nets *net)
2262 {
2263 int old_cwnd = net->cwnd;
2264
2265 /* JRS - reset as if the state were being changed to timeout */
2266 htcp_reset(&net->cc_mod.htcp_ca);
2267 net->ssthresh = htcp_recalc_ssthresh(net);
2268 net->cwnd = net->mtu;
2269 net->partial_bytes_acked = 0;
2270 if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_CWND_MONITOR_ENABLE) {
2271 sctp_log_cwnd(stcb, net, net->cwnd - old_cwnd, SCTP_CWND_LOG_FROM_RTX);
2272 }
2273 }
2274
2275 static void
2276 sctp_htcp_cwnd_update_after_ecn_echo(struct sctp_tcb *stcb,
2277 struct sctp_nets *net, int in_window, int num_pkt_lost SCTP_UNUSED)
2278 {
2279 int old_cwnd;
2280
2281 old_cwnd = net->cwnd;
2282
2283 /* JRS - reset hctp as if state changed */
2284 if (in_window == 0) {
2285 htcp_reset(&net->cc_mod.htcp_ca);
2286 SCTP_STAT_INCR(sctps_ecnereducedcwnd);
2287 net->ssthresh = htcp_recalc_ssthresh(net);
2288 if (net->ssthresh < net->mtu) {
2289 net->ssthresh = net->mtu;
2290 /* here back off the timer as well, to slow us down */
2291 net->RTO <<= 1;
2292 }
2293 net->cwnd = net->ssthresh;
2294 if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_CWND_MONITOR_ENABLE) {
2295 sctp_log_cwnd(stcb, net, (net->cwnd - old_cwnd), SCTP_CWND_LOG_FROM_SAT);
2296 }
2297 }
2298 }
2299
2300 struct sctp_cc_functions sctp_cc_functions[] = {
2301 {
2302 .sctp_set_initial_cc_param = sctp_set_initial_cc_param,
2303 .sctp_cwnd_update_after_sack = sctp_cwnd_update_after_sack,
2304 .sctp_cwnd_update_exit_pf = sctp_cwnd_update_exit_pf_common,
2305 .sctp_cwnd_update_after_fr = sctp_cwnd_update_after_fr,
2306 .sctp_cwnd_update_after_timeout = sctp_cwnd_update_after_timeout,
2307 .sctp_cwnd_update_after_ecn_echo = sctp_cwnd_update_after_ecn_echo,
2308 .sctp_cwnd_update_after_packet_dropped = sctp_cwnd_update_after_packet_dropped,
2309 .sctp_cwnd_update_after_output = sctp_cwnd_update_after_output,
2310 },
2311 {
2312 .sctp_set_initial_cc_param = sctp_set_initial_cc_param,
2313 .sctp_cwnd_update_after_sack = sctp_hs_cwnd_update_after_sack,
2314 .sctp_cwnd_update_exit_pf = sctp_cwnd_update_exit_pf_common,
2315 .sctp_cwnd_update_after_fr = sctp_hs_cwnd_update_after_fr,
2316 .sctp_cwnd_update_after_timeout = sctp_cwnd_update_after_timeout,
2317 .sctp_cwnd_update_after_ecn_echo = sctp_cwnd_update_after_ecn_echo,
2318 .sctp_cwnd_update_after_packet_dropped = sctp_cwnd_update_after_packet_dropped,
2319 .sctp_cwnd_update_after_output = sctp_cwnd_update_after_output,
2320 },
2321 {
2322 .sctp_set_initial_cc_param = sctp_htcp_set_initial_cc_param,
2323 .sctp_cwnd_update_after_sack = sctp_htcp_cwnd_update_after_sack,
2324 .sctp_cwnd_update_exit_pf = sctp_cwnd_update_exit_pf_common,
2325 .sctp_cwnd_update_after_fr = sctp_htcp_cwnd_update_after_fr,
2326 .sctp_cwnd_update_after_timeout = sctp_htcp_cwnd_update_after_timeout,
2327 .sctp_cwnd_update_after_ecn_echo = sctp_htcp_cwnd_update_after_ecn_echo,
2328 .sctp_cwnd_update_after_packet_dropped = sctp_cwnd_update_after_packet_dropped,
2329 .sctp_cwnd_update_after_output = sctp_cwnd_update_after_output,
2330 },
2331 {
2332 .sctp_set_initial_cc_param = sctp_set_rtcc_initial_cc_param,
2333 .sctp_cwnd_update_after_sack = sctp_cwnd_update_rtcc_after_sack,
2334 .sctp_cwnd_update_exit_pf = sctp_cwnd_update_exit_pf_common,
2335 .sctp_cwnd_update_after_fr = sctp_cwnd_update_after_fr,
2336 .sctp_cwnd_update_after_timeout = sctp_cwnd_update_after_timeout,
2337 .sctp_cwnd_update_after_ecn_echo = sctp_cwnd_update_rtcc_after_ecn_echo,
2338 .sctp_cwnd_update_after_packet_dropped = sctp_cwnd_update_after_packet_dropped,
2339 .sctp_cwnd_update_after_output = sctp_cwnd_update_after_output,
2340 .sctp_cwnd_update_packet_transmitted = sctp_cwnd_update_rtcc_packet_transmitted,
2341 .sctp_cwnd_update_tsn_acknowledged = sctp_cwnd_update_rtcc_tsn_acknowledged,
2342 .sctp_cwnd_new_transmission_begins = sctp_cwnd_new_rtcc_transmission_begins,
2343 .sctp_cwnd_prepare_net_for_sack = sctp_cwnd_prepare_rtcc_net_for_sack,
2344 .sctp_cwnd_socket_option = sctp_cwnd_rtcc_socket_option,
2345 .sctp_rtt_calculated = sctp_rtt_rtcc_calculated
2346 }
2347 };
Cache object: 006f57baf752add4416837b989ac5745
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