2 * Copyright (c) 2001-2007, by Cisco Systems, Inc. All rights reserved.
3 * Copyright (c) 2008-2011, by Randall Stewart. All rights reserved.
4 * Copyright (c) 2008-2011, by Michael Tuexen. All rights reserved.
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions are met:
9 * a) Redistributions of source code must retain the above copyright notice,
10 * this list of conditions and the following disclaimer.
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.
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.
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.
33 #include <netinet/sctp_os.h>
34 #include <netinet/sctp_var.h>
35 #include <netinet/sctp_sysctl.h>
36 #include <netinet/sctp_pcb.h>
37 #include <netinet/sctp_header.h>
38 #include <netinet/sctputil.h>
39 #include <netinet/sctp_output.h>
40 #include <netinet/sctp_input.h>
41 #include <netinet/sctp_indata.h>
42 #include <netinet/sctp_uio.h>
43 #include <netinet/sctp_timer.h>
44 #include <netinet/sctp_auth.h>
45 #include <netinet/sctp_asconf.h>
46 #include <netinet/sctp_dtrace_declare.h>
47 #include <sys/cdefs.h>
48 __FBSDID("$FreeBSD$");
50 #define SHIFT_MPTCP_MULTI_N 40
51 #define SHIFT_MPTCP_MULTI_Z 16
52 #define SHIFT_MPTCP_MULTI 8
55 sctp_set_initial_cc_param(struct sctp_tcb *stcb, struct sctp_nets *net)
57 struct sctp_association *assoc;
61 cwnd_in_mtu = SCTP_BASE_SYSCTL(sctp_initial_cwnd);
62 if (cwnd_in_mtu == 0) {
63 /* Using 0 means that the value of RFC 4960 is used. */
64 net->cwnd = min((net->mtu * 4), max((2 * net->mtu), SCTP_INITIAL_CWND));
67 * We take the minimum of the burst limit and the initial
70 if ((assoc->max_burst > 0) && (cwnd_in_mtu > assoc->max_burst))
71 cwnd_in_mtu = assoc->max_burst;
72 net->cwnd = (net->mtu - sizeof(struct sctphdr)) * cwnd_in_mtu;
74 if ((stcb->asoc.sctp_cmt_on_off == SCTP_CMT_RPV1) ||
75 (stcb->asoc.sctp_cmt_on_off == SCTP_CMT_RPV2)) {
76 /* In case of resource pooling initialize appropriately */
77 net->cwnd /= assoc->numnets;
78 if (net->cwnd < (net->mtu - sizeof(struct sctphdr))) {
79 net->cwnd = net->mtu - sizeof(struct sctphdr);
82 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,
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);
94 sctp_cwnd_update_after_fr(struct sctp_tcb *stcb,
95 struct sctp_association *asoc)
97 struct sctp_nets *net;
98 uint32_t t_ssthresh, t_cwnd;
101 /* MT FIXME: Don't compute this over and over again */
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;
110 if (net->lastsa > 0) {
111 t_ucwnd_sbw += (uint64_t) net->cwnd / (uint64_t) net->lastsa;
114 if (t_ucwnd_sbw == 0) {
119 * CMT fast recovery code. Need to debug. ((sctp_cmt_on_off > 0) &&
120 * (net->fast_retran_loss_recovery == 0)))
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) {
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.
133 struct sctp_tmit_chunk *lchk;
134 int old_cwnd = net->cwnd;
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);
145 if (asoc->sctp_cmt_on_off == SCTP_CMT_RPV2) {
150 * lastsa>>3; we don't need
157 * Short Version => Equal to
160 net->ssthresh = (uint32_t) (((uint64_t) 4 *
161 (uint64_t) net->mtu *
162 (uint64_t) net->cwnd) /
165 /* INCREASE FACTOR */ ;
167 if ((net->cwnd > t_cwnd / 2) &&
168 (net->ssthresh < net->cwnd - t_cwnd / 2)) {
169 net->ssthresh = net->cwnd - t_cwnd / 2;
171 if (net->ssthresh < net->mtu) {
172 net->ssthresh = net->mtu;
175 net->ssthresh = net->cwnd / 2;
176 if (net->ssthresh < (net->mtu * 2)) {
177 net->ssthresh = 2 * net->mtu;
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);
188 lchk = TAILQ_FIRST(&asoc->send_queue);
190 net->partial_bytes_acked = 0;
191 /* Turn on fast recovery window */
192 asoc->fast_retran_loss_recovery = 1;
194 /* Mark end of the window */
195 asoc->fast_recovery_tsn = asoc->sending_seq - 1;
197 asoc->fast_recovery_tsn = lchk->rec.data.TSN_seq - 1;
201 * CMT fast recovery -- per destination
204 net->fast_retran_loss_recovery = 1;
207 /* Mark end of the window */
208 net->fast_recovery_tsn = asoc->sending_seq - 1;
210 net->fast_recovery_tsn = lchk->rec.data.TSN_seq - 1;
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);
218 } else if (net->net_ack > 0) {
220 * Mark a peg that we WOULD have done a cwnd
221 * reduction but RFC2582 prevented this action.
223 SCTP_STAT_INCR(sctps_fastretransinrtt);
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 */
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)
238 uint64_t oth, probepoint;
240 probepoint = (((uint64_t) net->cwnd) << 32);
241 if (net->rtt > net->cc_mod.rtcc.lbw_rtt + rtt_offset) {
243 * rtt increased we don't update bw.. so we don't update the
247 probepoint |= ((5 << 16) | 1);
248 SDT_PROBE(sctp, cwnd, net, rttvar,
250 ((net->cc_mod.rtcc.lbw << 32) | nbw),
251 ((net->cc_mod.rtcc.lbw_rtt << 32) | net->rtt),
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++;
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;
266 oth |= net->cc_mod.rtcc.step_cnt;
268 oth |= net->cc_mod.rtcc.last_step_state;
269 SDT_PROBE(sctp, cwnd, net, rttstep,
271 ((net->cc_mod.rtcc.lbw << 32) | nbw),
272 ((net->cc_mod.rtcc.lbw_rtt << 32) | net->rtt),
275 if (net->cwnd > (4 * net->mtu)) {
276 net->cwnd -= net->mtu;
277 net->cc_mod.rtcc.vol_reduce++;
279 net->cc_mod.rtcc.step_cnt = 0;
285 if (net->rtt < net->cc_mod.rtcc.lbw_rtt - rtt_offset) {
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
292 probepoint |= ((6 << 16) | 0);
293 SDT_PROBE(sctp, cwnd, net, rttvar,
295 ((net->cc_mod.rtcc.lbw << 32) | nbw),
296 ((net->cc_mod.rtcc.lbw_rtt << 32) | net->rtt),
299 if (net->cc_mod.rtcc.steady_step) {
300 oth = net->cc_mod.rtcc.vol_reduce;
302 oth |= net->cc_mod.rtcc.step_cnt;
304 oth |= net->cc_mod.rtcc.last_step_state;
305 SDT_PROBE(sctp, cwnd, net, rttstep,
307 ((net->cc_mod.rtcc.lbw << 32) | nbw),
308 ((net->cc_mod.rtcc.lbw_rtt << 32) | net->rtt),
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;
317 net->cc_mod.rtcc.last_step_state = 6;
318 net->cc_mod.rtcc.step_cnt = 0;
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)
326 else if (inst_ind == SCTP_INST_NEUTRAL)
332 * Ok bw and rtt remained the same .. no update to any
335 probepoint |= ((7 << 16) | net->cc_mod.rtcc.ret_from_eq);
336 SDT_PROBE(sctp, cwnd, net, rttvar,
338 ((net->cc_mod.rtcc.lbw << 32) | nbw),
339 ((net->cc_mod.rtcc.lbw_rtt << 32) | net->rtt),
343 if ((net->cc_mod.rtcc.steady_step) && (inst_ind != SCTP_INST_LOOSING)) {
344 if (net->cc_mod.rtcc.last_step_state == 5)
345 net->cc_mod.rtcc.step_cnt++;
347 net->cc_mod.rtcc.step_cnt = 1;
348 net->cc_mod.rtcc.last_step_state = 5;
349 if ((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) &&
351 ((net->cc_mod.rtcc.step_cnt % net->cc_mod.rtcc.steady_step) == 0))) {
352 /* Try a step down */
353 if (net->cwnd > (4 * net->mtu)) {
354 net->cwnd -= net->mtu;
355 net->cc_mod.rtcc.vol_reduce++;
358 net->cc_mod.rtcc.step_cnt = 0;
362 if (inst_ind == SCTP_INST_GAINING)
364 else if (inst_ind == SCTP_INST_NEUTRAL)
367 return ((int)net->cc_mod.rtcc.ret_from_eq);
371 cc_bw_decrease(struct sctp_tcb *stcb, struct sctp_nets *net, uint64_t nbw, uint64_t rtt_offset,
372 uint64_t vtag, uint8_t inst_ind)
374 uint64_t oth, probepoint;
376 /* Bandwidth decreased. */
377 probepoint = (((uint64_t) net->cwnd) << 32);
378 if (net->rtt > net->cc_mod.rtcc.lbw_rtt + rtt_offset) {
380 /* Did we add more */
381 if ((net->cwnd > net->cc_mod.rtcc.cwnd_at_bw_set) &&
382 (inst_ind != SCTP_INST_LOOSING)) {
383 /* We caused it maybe.. back off? */
385 probepoint |= ((1 << 16) | 1);
386 SDT_PROBE(sctp, cwnd, net, rttvar,
388 ((net->cc_mod.rtcc.lbw << 32) | nbw),
389 ((net->cc_mod.rtcc.lbw_rtt << 32) | net->rtt),
393 if (net->cc_mod.rtcc.ret_from_eq) {
395 * Switch over to CA if we are less
398 net->ssthresh = net->cwnd - 1;
399 net->partial_bytes_acked = 0;
404 probepoint |= ((2 << 16) | 0);
405 SDT_PROBE(sctp, cwnd, net, rttvar,
407 ((net->cc_mod.rtcc.lbw << 32) | nbw),
408 ((net->cc_mod.rtcc.lbw_rtt << 32) | net->rtt),
412 /* Someone else - fight for more? */
413 if (net->cc_mod.rtcc.steady_step) {
414 oth = net->cc_mod.rtcc.vol_reduce;
416 oth |= net->cc_mod.rtcc.step_cnt;
418 oth |= net->cc_mod.rtcc.last_step_state;
419 SDT_PROBE(sctp, cwnd, net, rttstep,
421 ((net->cc_mod.rtcc.lbw << 32) | nbw),
422 ((net->cc_mod.rtcc.lbw_rtt << 32) | net->rtt),
426 * Did we voluntarily give up some? if so take one
429 if ((net->cc_mod.rtcc.vol_reduce) &&
430 (inst_ind != SCTP_INST_GAINING)) {
431 net->cwnd += net->mtu;
432 net->cc_mod.rtcc.vol_reduce--;
434 net->cc_mod.rtcc.last_step_state = 2;
435 net->cc_mod.rtcc.step_cnt = 0;
438 } else if (net->rtt < net->cc_mod.rtcc.lbw_rtt - rtt_offset) {
439 /* bw & rtt decreased */
441 probepoint |= ((3 << 16) | 0);
442 SDT_PROBE(sctp, cwnd, net, rttvar,
444 ((net->cc_mod.rtcc.lbw << 32) | nbw),
445 ((net->cc_mod.rtcc.lbw_rtt << 32) | net->rtt),
448 if (net->cc_mod.rtcc.steady_step) {
449 oth = net->cc_mod.rtcc.vol_reduce;
451 oth |= net->cc_mod.rtcc.step_cnt;
453 oth |= net->cc_mod.rtcc.last_step_state;
454 SDT_PROBE(sctp, cwnd, net, rttstep,
456 ((net->cc_mod.rtcc.lbw << 32) | nbw),
457 ((net->cc_mod.rtcc.lbw_rtt << 32) | net->rtt),
460 if ((net->cc_mod.rtcc.vol_reduce) &&
461 (inst_ind != SCTP_INST_GAINING)) {
462 net->cwnd += net->mtu;
463 net->cc_mod.rtcc.vol_reduce--;
465 net->cc_mod.rtcc.last_step_state = 3;
466 net->cc_mod.rtcc.step_cnt = 0;
470 /* The bw decreased but rtt stayed the same */
472 probepoint |= ((4 << 16) | 0);
473 SDT_PROBE(sctp, cwnd, net, rttvar,
475 ((net->cc_mod.rtcc.lbw << 32) | nbw),
476 ((net->cc_mod.rtcc.lbw_rtt << 32) | net->rtt),
479 if (net->cc_mod.rtcc.steady_step) {
480 oth = net->cc_mod.rtcc.vol_reduce;
482 oth |= net->cc_mod.rtcc.step_cnt;
484 oth |= net->cc_mod.rtcc.last_step_state;
485 SDT_PROBE(sctp, cwnd, net, rttstep,
487 ((net->cc_mod.rtcc.lbw << 32) | nbw),
488 ((net->cc_mod.rtcc.lbw_rtt << 32) | net->rtt),
491 if ((net->cc_mod.rtcc.vol_reduce) &&
492 (inst_ind != SCTP_INST_GAINING)) {
493 net->cwnd += net->mtu;
494 net->cc_mod.rtcc.vol_reduce--;
496 net->cc_mod.rtcc.last_step_state = 4;
497 net->cc_mod.rtcc.step_cnt = 0;
500 net->cc_mod.rtcc.lbw = nbw;
501 net->cc_mod.rtcc.lbw_rtt = net->rtt;
502 net->cc_mod.rtcc.cwnd_at_bw_set = net->cwnd;
503 if (inst_ind == SCTP_INST_GAINING) {
511 cc_bw_increase(struct sctp_tcb *stcb, struct sctp_nets *net, uint64_t nbw,
512 uint64_t vtag, uint8_t inst_ind)
514 uint64_t oth, probepoint;
517 * BW increased, so update and return 0, since all actions in our
518 * table say to do the normal CC update. Note that we pay no
519 * attention to the inst_ind since our overall sum is increasing.
522 probepoint = (((uint64_t) net->cwnd) << 32);
523 SDT_PROBE(sctp, cwnd, net, rttvar,
525 ((net->cc_mod.rtcc.lbw << 32) | nbw),
526 ((net->cc_mod.rtcc.lbw_rtt << 32) | net->rtt),
529 if (net->cc_mod.rtcc.steady_step) {
530 oth = net->cc_mod.rtcc.vol_reduce;
532 oth |= net->cc_mod.rtcc.step_cnt;
534 oth |= net->cc_mod.rtcc.last_step_state;
535 SDT_PROBE(sctp, cwnd, net, rttstep,
537 ((net->cc_mod.rtcc.lbw << 32) | nbw),
538 ((net->cc_mod.rtcc.lbw_rtt << 32) | net->rtt),
541 net->cc_mod.rtcc.last_step_state = 0;
542 net->cc_mod.rtcc.step_cnt = 0;
543 net->cc_mod.rtcc.vol_reduce = 0;
545 net->cc_mod.rtcc.lbw = nbw;
546 net->cc_mod.rtcc.lbw_rtt = net->rtt;
547 net->cc_mod.rtcc.cwnd_at_bw_set = net->cwnd;
551 /* RTCC Algoritm to limit growth of cwnd, return
552 * true if you want to NOT allow cwnd growth
555 cc_bw_limit(struct sctp_tcb *stcb, struct sctp_nets *net, uint64_t nbw)
557 uint64_t bw_offset, rtt_offset, rtt, vtag, probepoint;
558 uint64_t bytes_for_this_rtt, inst_bw;
559 uint64_t div, inst_off;
565 * Here we need to see if we want
566 * to limit cwnd growth due to increase
567 * in overall rtt but no increase in bw.
568 * We use the following table to figure
569 * out what we should do. When we return
570 * 0, cc update goes on as planned. If we
571 * return 1, then no cc update happens and cwnd
572 * stays where it is at.
573 * ----------------------------------
575 * *********************************
576 * INC | INC | return 0
577 * ----------------------------------
578 * INC | SAME | return 0
579 * ----------------------------------
580 * INC | DECR | return 0
581 * ----------------------------------
582 * SAME | INC | return 1
583 * ----------------------------------
584 * SAME | SAME | return 1
585 * ----------------------------------
586 * SAME | DECR | return 0
587 * ----------------------------------
588 * DECR | INC | return 0 or 1 based on if we caused.
589 * ----------------------------------
590 * DECR | SAME | return 0
591 * ----------------------------------
592 * DECR | DECR | return 0
593 * ----------------------------------
595 * We are a bit fuzz on what an increase or
596 * decrease is. For BW it is the same if
597 * it did not change within 1/64th. For
598 * RTT it stayed the same if it did not
599 * change within 1/32nd
601 bw_shift = SCTP_BASE_SYSCTL(sctp_rttvar_bw);
602 rtt = stcb->asoc.my_vtag;
603 vtag = (rtt << 32) | (((uint32_t) (stcb->sctp_ep->sctp_lport)) << 16) | (stcb->rport);
604 probepoint = (((uint64_t) net->cwnd) << 32);
606 if (net->cc_mod.rtcc.rtt_set_this_sack) {
607 net->cc_mod.rtcc.rtt_set_this_sack = 0;
608 bytes_for_this_rtt = net->cc_mod.rtcc.bw_bytes - net->cc_mod.rtcc.bw_bytes_at_last_rttc;
609 net->cc_mod.rtcc.bw_bytes_at_last_rttc = net->cc_mod.rtcc.bw_bytes;
611 div = net->rtt / 1000;
613 inst_bw = bytes_for_this_rtt / div;
614 inst_off = inst_bw >> bw_shift;
616 inst_ind = SCTP_INST_GAINING;
617 else if ((inst_bw + inst_off) < nbw)
618 inst_ind = SCTP_INST_LOOSING;
620 inst_ind = SCTP_INST_NEUTRAL;
621 probepoint |= ((0xb << 16) | inst_ind);
623 inst_bw = bytes_for_this_rtt / (uint64_t) (net->rtt);
624 /* Can't determine do not change */
625 inst_ind = net->cc_mod.rtcc.last_inst_ind;
626 probepoint |= ((0xc << 16) | inst_ind);
629 inst_bw = bytes_for_this_rtt;
630 /* Can't determine do not change */
631 inst_ind = net->cc_mod.rtcc.last_inst_ind;
632 probepoint |= ((0xd << 16) | inst_ind);
634 SDT_PROBE(sctp, cwnd, net, rttvar,
636 ((nbw << 32) | inst_bw),
637 ((net->cc_mod.rtcc.lbw_rtt << 32) | rtt),
641 /* No rtt measurement, use last one */
642 inst_ind = net->cc_mod.rtcc.last_inst_ind;
644 bw_offset = net->cc_mod.rtcc.lbw >> bw_shift;
645 if (nbw > net->cc_mod.rtcc.lbw + bw_offset) {
646 ret = cc_bw_increase(stcb, net, nbw, vtag, inst_ind);
649 rtt_offset = net->cc_mod.rtcc.lbw_rtt >> SCTP_BASE_SYSCTL(sctp_rttvar_rtt);
650 if (nbw < net->cc_mod.rtcc.lbw - bw_offset) {
651 ret = cc_bw_decrease(stcb, net, nbw, rtt_offset, vtag, inst_ind);
655 * If we reach here then we are in a situation where the bw stayed
658 ret = cc_bw_same(stcb, net, nbw, rtt_offset, vtag, inst_ind);
660 net->cc_mod.rtcc.last_inst_ind = inst_ind;
665 sctp_cwnd_update_after_sack_common(struct sctp_tcb *stcb,
666 struct sctp_association *asoc,
667 int accum_moved, int reneged_all, int will_exit, int use_rtcc)
669 struct sctp_nets *net;
671 uint32_t t_ssthresh, t_cwnd, incr;
672 uint64_t t_ucwnd_sbw;
673 uint64_t t_path_mptcp;
674 uint64_t mptcp_like_alpha;
678 /* MT FIXME: Don't compute this over and over again */
683 mptcp_like_alpha = 1;
684 if ((stcb->asoc.sctp_cmt_on_off == SCTP_CMT_RPV1) ||
685 (stcb->asoc.sctp_cmt_on_off == SCTP_CMT_RPV2) ||
686 (stcb->asoc.sctp_cmt_on_off == SCTP_CMT_MPTCP)) {
688 TAILQ_FOREACH(net, &stcb->asoc.nets, sctp_next) {
689 t_ssthresh += net->ssthresh;
691 /* lastsa>>3; we don't need to devide ... */
696 t_ucwnd_sbw += (uint64_t) net->cwnd / (uint64_t) srtt;
697 t_path_mptcp += (((uint64_t) net->cwnd) << SHIFT_MPTCP_MULTI_Z) /
698 (((uint64_t) net->mtu) * (uint64_t) srtt);
699 tmp = (((uint64_t) net->cwnd) << SHIFT_MPTCP_MULTI_N) /
700 ((uint64_t) net->mtu * (uint64_t) (srtt * srtt));
701 if (tmp > max_path) {
706 if (t_ucwnd_sbw == 0) {
709 if (t_path_mptcp > 0) {
710 mptcp_like_alpha = max_path / (t_path_mptcp * t_path_mptcp);
712 mptcp_like_alpha = 1;
715 /******************************/
716 /* update cwnd and Early FR */
717 /******************************/
718 TAILQ_FOREACH(net, &asoc->nets, sctp_next) {
720 #ifdef JANA_CMT_FAST_RECOVERY
722 * CMT fast recovery code. Need to debug.
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;
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);
738 #ifdef JANA_CMT_FAST_RECOVERY
740 * CMT fast recovery code
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) {
750 if (asoc->fast_retran_loss_recovery &&
752 (asoc->sctp_cmt_on_off == 0)) {
754 * If we are in loss recovery we skip any cwnd
760 * Did any measurements go on for this network?
762 if (use_rtcc && (net->cc_mod.rtcc.tls_needs_set > 0)) {
766 * At this point our bw_bytes has been updated by
767 * incoming sack information.
769 * But our bw may not yet be set.
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);
775 nbw = net->cc_mod.rtcc.bw_bytes;
777 if (net->cc_mod.rtcc.lbw) {
778 if (cc_bw_limit(stcb, net, nbw)) {
779 /* Hold here, no update */
783 uint64_t vtag, probepoint;
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) |
791 SDT_PROBE(sctp, cwnd, net, rttvar,
794 ((net->cc_mod.rtcc.lbw_rtt << 32) | net->rtt),
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;
806 * CMT: CUC algorithm. Update cwnd if pseudo-cumack has
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) {
817 old_cwnd = net->cwnd;
818 switch (asoc->sctp_cmt_on_off) {
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);
836 * lastsa>>3; we don't need
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 */
860 limit = (uint32_t) (((uint64_t) net->mtu *
862 (uint64_t) SCTP_BASE_SYSCTL(sctp_L2_abc_variable)) >>
864 incr = (uint32_t) (((uint64_t) net->net_ack *
870 if (incr > net->net_ack) {
873 if (incr > net->mtu) {
879 if (incr > net->mtu * SCTP_BASE_SYSCTL(sctp_L2_abc_variable)) {
880 incr = net->mtu * SCTP_BASE_SYSCTL(sctp_L2_abc_variable);
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);
889 SDT_PROBE(sctp, cwnd, net, ack,
891 ((stcb->sctp_ep->sctp_lport << 16) | (stcb->rport)),
893 old_cwnd, net->cwnd);
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);
901 /* We are in congestion avoidance */
905 net->partial_bytes_acked += net->net_ack;
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) {
913 incr = (uint32_t) (((uint64_t) net->mtu *
914 (uint64_t) net->ssthresh) /
915 (uint64_t) t_ssthresh);
922 * lastsa>>3; we don't need
929 incr = (uint32_t) ((uint64_t) net->mtu *
930 (uint64_t) net->cwnd /
933 /* INCREASE FACTOR */
939 incr = (uint32_t) ((mptcp_like_alpha *
940 (uint64_t) net->cwnd) >>
942 if (incr > net->mtu) {
951 SDT_PROBE(sctp, cwnd, net, ack,
953 ((stcb->sctp_ep->sctp_lport << 16) | (stcb->rport)),
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);
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);
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);
977 sctp_cwnd_update_exit_pf_common(struct sctp_tcb *stcb, struct sctp_nets *net)
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",
992 sctp_cwnd_update_after_timeout(struct sctp_tcb *stcb, struct sctp_nets *net)
994 int old_cwnd = net->cwnd;
995 uint32_t t_ssthresh, t_cwnd;
996 uint64_t t_ucwnd_sbw;
998 /* MT FIXME: Don't compute this over and over again */
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;
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 ... */
1013 t_ucwnd_sbw += (uint64_t) lnet->cwnd / (uint64_t) srtt;
1016 if (t_ucwnd_sbw < 1) {
1019 if (stcb->asoc.sctp_cmt_on_off == SCTP_CMT_RPV1) {
1020 net->ssthresh = (uint32_t) (((uint64_t) 4 *
1021 (uint64_t) net->mtu *
1022 (uint64_t) net->ssthresh) /
1023 (uint64_t) t_ssthresh);
1028 /* lastsa>>3; we don't need to divide ... */
1032 cc_delta = t_ucwnd_sbw * (uint64_t) srtt / 2;
1033 if (cc_delta < t_cwnd) {
1034 net->ssthresh = (uint32_t) ((uint64_t) t_cwnd - cc_delta);
1036 net->ssthresh = net->mtu;
1039 if ((net->cwnd > t_cwnd / 2) &&
1040 (net->ssthresh < net->cwnd - t_cwnd / 2)) {
1041 net->ssthresh = net->cwnd - t_cwnd / 2;
1043 if (net->ssthresh < net->mtu) {
1044 net->ssthresh = net->mtu;
1047 net->ssthresh = max(net->cwnd / 2, 4 * net->mtu);
1049 net->cwnd = net->mtu;
1050 net->partial_bytes_acked = 0;
1051 SDT_PROBE(sctp, cwnd, net, to,
1053 ((stcb->sctp_ep->sctp_lport << 16) | (stcb->rport)),
1055 old_cwnd, net->cwnd);
1056 if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_CWND_MONITOR_ENABLE) {
1057 sctp_log_cwnd(stcb, net, net->cwnd - old_cwnd, SCTP_CWND_LOG_FROM_RTX);
1062 sctp_cwnd_update_after_ecn_echo_common(struct sctp_tcb *stcb, struct sctp_nets *net,
1063 int in_window, int num_pkt_lost, int use_rtcc)
1065 int old_cwnd = net->cwnd;
1067 if ((use_rtcc) && (net->lan_type == SCTP_LAN_LOCAL) && (net->cc_mod.rtcc.use_dccc_ecn)) {
1068 /* Data center Congestion Control */
1069 if (in_window == 0) {
1071 * Go to CA with the cwnd at the point we sent the
1072 * TSN that was marked with a CE.
1074 if (net->ecn_prev_cwnd < net->cwnd) {
1075 /* Restore to prev cwnd */
1076 net->cwnd = net->ecn_prev_cwnd - (net->mtu * num_pkt_lost);
1078 /* Just cut in 1/2 */
1082 net->ssthresh = net->cwnd - (num_pkt_lost * net->mtu);
1083 if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_CWND_MONITOR_ENABLE) {
1084 sctp_log_cwnd(stcb, net, (net->cwnd - old_cwnd), SCTP_CWND_LOG_FROM_SAT);
1088 * Further tuning down required over the drastic
1091 net->ssthresh -= (net->mtu * num_pkt_lost);
1092 net->cwnd -= (net->mtu * num_pkt_lost);
1093 if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_CWND_MONITOR_ENABLE) {
1094 sctp_log_cwnd(stcb, net, (net->cwnd - old_cwnd), SCTP_CWND_LOG_FROM_SAT);
1097 SCTP_STAT_INCR(sctps_ecnereducedcwnd);
1099 if (in_window == 0) {
1100 SCTP_STAT_INCR(sctps_ecnereducedcwnd);
1101 net->ssthresh = net->cwnd / 2;
1102 if (net->ssthresh < net->mtu) {
1103 net->ssthresh = net->mtu;
1105 * here back off the timer as well, to slow
1110 net->cwnd = net->ssthresh;
1111 SDT_PROBE(sctp, cwnd, net, ecn,
1113 ((stcb->sctp_ep->sctp_lport << 16) | (stcb->rport)),
1115 old_cwnd, net->cwnd);
1116 if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_CWND_MONITOR_ENABLE) {
1117 sctp_log_cwnd(stcb, net, (net->cwnd - old_cwnd), SCTP_CWND_LOG_FROM_SAT);
1125 sctp_cwnd_update_after_packet_dropped(struct sctp_tcb *stcb,
1126 struct sctp_nets *net, struct sctp_pktdrop_chunk *cp,
1127 uint32_t * bottle_bw, uint32_t * on_queue)
1132 int old_cwnd = net->cwnd;
1134 /* need real RTT in msd for this calc */
1135 rtt = net->rtt / 1000;
1136 /* get bottle neck bw */
1137 *bottle_bw = ntohl(cp->bottle_bw);
1138 /* and whats on queue */
1139 *on_queue = ntohl(cp->current_onq);
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
1144 if (*on_queue < net->flight_size)
1145 *on_queue = net->flight_size;
1146 /* calculate the available space */
1147 bw_avail = (*bottle_bw * rtt) / 1000;
1148 if (bw_avail > *bottle_bw) {
1150 * Cap the growth to no more than the bottle neck. This can
1151 * happen as RTT slides up due to queues. It also means if
1152 * you have more than a 1 second RTT with a empty queue you
1153 * will be limited to the bottle_bw per second no matter if
1154 * other points have 1/2 the RTT and you could get more
1157 bw_avail = *bottle_bw;
1159 if (*on_queue > bw_avail) {
1161 * No room for anything else don't allow anything else to be
1162 * "added to the fire".
1164 int seg_inflight, seg_onqueue, my_portion;
1166 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) {
1172 * undo any cwnd adjustment that the sack might have
1175 net->cwnd = net->prev_cwnd;
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;
1182 /* Have I made an adjustment already */
1183 if (net->cwnd > net->flight_size) {
1185 * for this flight I made an adjustment we need to
1186 * decrease the portion by a share our previous
1191 diff_adj = net->cwnd - net->flight_size;
1192 if (diff_adj > my_portion)
1195 my_portion -= diff_adj;
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.
1202 net->cwnd -= my_portion;
1204 /* we will NOT back down more than 1 MTU */
1205 if (net->cwnd <= net->mtu) {
1206 net->cwnd = net->mtu;
1209 net->ssthresh = net->cwnd - 1;
1212 * Take 1/4 of the space left or max burst up .. whichever
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;
1222 if (net->cwnd > bw_avail) {
1223 /* We can't exceed the pipe size */
1224 net->cwnd = bw_avail;
1226 if (net->cwnd < net->mtu) {
1227 /* We always have 1 MTU */
1228 net->cwnd = net->mtu;
1230 if (net->cwnd - old_cwnd != 0) {
1231 /* log only changes */
1232 SDT_PROBE(sctp, cwnd, net, pd,
1234 ((stcb->sctp_ep->sctp_lport << 16) | (stcb->rport)),
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);
1245 sctp_cwnd_update_after_output(struct sctp_tcb *stcb,
1246 struct sctp_nets *net, int burst_limit)
1248 int old_cwnd = net->cwnd;
1250 if (net->ssthresh < net->cwnd)
1251 net->ssthresh = net->cwnd;
1253 net->cwnd = (net->flight_size + (burst_limit * net->mtu));
1254 SDT_PROBE(sctp, cwnd, net, bl,
1256 ((stcb->sctp_ep->sctp_lport << 16) | (stcb->rport)),
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);
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)
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);
1275 sctp_cwnd_update_after_ecn_echo(struct sctp_tcb *stcb, struct sctp_nets *net,
1276 int in_window, int num_pkt_lost)
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);
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
1288 sctp_cwnd_update_rtcc_after_ecn_echo(struct sctp_tcb *stcb, struct sctp_nets *net,
1289 int in_window, int num_pkt_lost)
1291 sctp_cwnd_update_after_ecn_echo_common(stcb, net, in_window, num_pkt_lost, 1);
1297 sctp_cwnd_update_rtcc_tsn_acknowledged(struct sctp_nets *net,
1298 struct sctp_tmit_chunk *tp1)
1300 net->cc_mod.rtcc.bw_bytes += tp1->send_size;
1304 sctp_cwnd_prepare_rtcc_net_for_sack(struct sctp_tcb *stcb,
1305 struct sctp_nets *net)
1307 if (net->cc_mod.rtcc.tls_needs_set > 0) {
1308 /* We had a bw measurment going on */
1309 struct timeval ltls;
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;
1318 sctp_cwnd_new_rtcc_transmission_begins(struct sctp_tcb *stcb,
1319 struct sctp_nets *net)
1321 uint64_t vtag, probepoint;
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) |
1327 probepoint = (((uint64_t) net->cwnd) << 32);
1329 probepoint |= ((8 << 16) | 0);
1330 SDT_PROBE(sctp, cwnd, net, rttvar,
1332 ((net->cc_mod.rtcc.lbw << 32) | 0),
1333 ((net->cc_mod.rtcc.lbw_rtt << 32) | net->rtt),
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;
1349 if (net->cc_mod.rtcc.ret_from_eq) {
1350 /* less aggressive one - reset cwnd too */
1351 uint32_t cwnd_in_mtu, cwnd;
1353 cwnd_in_mtu = SCTP_BASE_SYSCTL(sctp_initial_cwnd);
1354 if (cwnd_in_mtu == 0) {
1356 * Using 0 means that the value of RFC 4960
1359 cwnd = min((net->mtu * 4), max((2 * net->mtu), SCTP_INITIAL_CWND));
1362 * We take the minimum of the burst limit
1363 * and the initial congestion window.
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;
1369 if (net->cwnd > cwnd) {
1371 * Only set if we are not a timeout (i.e.
1381 sctp_set_rtcc_initial_cc_param(struct sctp_tcb *stcb,
1382 struct sctp_nets *net)
1384 uint64_t vtag, probepoint;
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) |
1393 SDT_PROBE(sctp, cwnd, net, rttvar,
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;
1418 sctp_cwnd_rtcc_socket_option(struct sctp_tcb *stcb, int setorget,
1419 struct sctp_cc_option *cc_opt)
1421 struct sctp_nets *net;
1423 if (setorget == 1) {
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)) {
1430 TAILQ_FOREACH(net, &stcb->asoc.nets, sctp_next) {
1431 net->cc_mod.rtcc.ret_from_eq = cc_opt->aid_value.assoc_value;
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)) {
1438 TAILQ_FOREACH(net, &stcb->asoc.nets, sctp_next) {
1439 net->cc_mod.rtcc.use_dccc_ecn = cc_opt->aid_value.assoc_value;
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;
1450 if (cc_opt->option == SCTP_CC_OPT_RTCC_SETMODE) {
1451 net = TAILQ_FIRST(&stcb->asoc.nets);
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);
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);
1467 cc_opt->aid_value.assoc_value = net->cc_mod.rtcc.steady_step;
1476 sctp_cwnd_update_rtcc_packet_transmitted(struct sctp_tcb *stcb,
1477 struct sctp_nets *net)
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;
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)
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);
1495 sctp_rtt_rtcc_calculated(struct sctp_tcb *stcb,
1496 struct sctp_nets *net, struct timeval *now)
1498 net->cc_mod.rtcc.rtt_set_this_sack = 1;
1501 /* Here starts Sally Floyds HS-TCP */
1503 struct sctp_hs_raise_drop {
1506 int32_t drop_percent;
1509 #define SCTP_HS_TABLE_SIZE 73
1511 struct sctp_hs_raise_drop sctp_cwnd_adjust[SCTP_HS_TABLE_SIZE] = {
1512 {38, 1, 50}, /* 0 */
1513 {118, 2, 44}, /* 1 */
1514 {221, 3, 41}, /* 2 */
1515 {347, 4, 38}, /* 3 */
1516 {495, 5, 37}, /* 4 */
1517 {663, 6, 35}, /* 5 */
1518 {851, 7, 34}, /* 6 */
1519 {1058, 8, 33}, /* 7 */
1520 {1284, 9, 32}, /* 8 */
1521 {1529, 10, 31}, /* 9 */
1522 {1793, 11, 30}, /* 10 */
1523 {2076, 12, 29}, /* 11 */
1524 {2378, 13, 28}, /* 12 */
1525 {2699, 14, 28}, /* 13 */
1526 {3039, 15, 27}, /* 14 */
1527 {3399, 16, 27}, /* 15 */
1528 {3778, 17, 26}, /* 16 */
1529 {4177, 18, 26}, /* 17 */
1530 {4596, 19, 25}, /* 18 */
1531 {5036, 20, 25}, /* 19 */
1532 {5497, 21, 24}, /* 20 */
1533 {5979, 22, 24}, /* 21 */
1534 {6483, 23, 23}, /* 22 */
1535 {7009, 24, 23}, /* 23 */
1536 {7558, 25, 22}, /* 24 */
1537 {8130, 26, 22}, /* 25 */
1538 {8726, 27, 22}, /* 26 */
1539 {9346, 28, 21}, /* 27 */
1540 {9991, 29, 21}, /* 28 */
1541 {10661, 30, 21}, /* 29 */
1542 {11358, 31, 20}, /* 30 */
1543 {12082, 32, 20}, /* 31 */
1544 {12834, 33, 20}, /* 32 */
1545 {13614, 34, 19}, /* 33 */
1546 {14424, 35, 19}, /* 34 */
1547 {15265, 36, 19}, /* 35 */
1548 {16137, 37, 19}, /* 36 */
1549 {17042, 38, 18}, /* 37 */
1550 {17981, 39, 18}, /* 38 */
1551 {18955, 40, 18}, /* 39 */
1552 {19965, 41, 17}, /* 40 */
1553 {21013, 42, 17}, /* 41 */
1554 {22101, 43, 17}, /* 42 */
1555 {23230, 44, 17}, /* 43 */
1556 {24402, 45, 16}, /* 44 */
1557 {25618, 46, 16}, /* 45 */
1558 {26881, 47, 16}, /* 46 */
1559 {28193, 48, 16}, /* 47 */
1560 {29557, 49, 15}, /* 48 */
1561 {30975, 50, 15}, /* 49 */
1562 {32450, 51, 15}, /* 50 */
1563 {33986, 52, 15}, /* 51 */
1564 {35586, 53, 14}, /* 52 */
1565 {37253, 54, 14}, /* 53 */
1566 {38992, 55, 14}, /* 54 */
1567 {40808, 56, 14}, /* 55 */
1568 {42707, 57, 13}, /* 56 */
1569 {44694, 58, 13}, /* 57 */
1570 {46776, 59, 13}, /* 58 */
1571 {48961, 60, 13}, /* 59 */
1572 {51258, 61, 13}, /* 60 */
1573 {53677, 62, 12}, /* 61 */
1574 {56230, 63, 12}, /* 62 */
1575 {58932, 64, 12}, /* 63 */
1576 {61799, 65, 12}, /* 64 */
1577 {64851, 66, 11}, /* 65 */
1578 {68113, 67, 11}, /* 66 */
1579 {71617, 68, 11}, /* 67 */
1580 {75401, 69, 10}, /* 68 */
1581 {79517, 70, 10}, /* 69 */
1582 {84035, 71, 10}, /* 70 */
1583 {89053, 72, 10}, /* 71 */
1584 {94717, 73, 9} /* 72 */
1588 sctp_hs_cwnd_increase(struct sctp_tcb *stcb, struct sctp_nets *net)
1590 int cur_val, i, indx, incr;
1592 cur_val = net->cwnd >> 10;
1593 indx = SCTP_HS_TABLE_SIZE - 1;
1595 printf("HS CC CAlled.\n");
1597 if (cur_val < sctp_cwnd_adjust[0].cwnd) {
1599 if (net->net_ack > net->mtu) {
1600 net->cwnd += net->mtu;
1601 if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_CWND_MONITOR_ENABLE) {
1602 sctp_log_cwnd(stcb, net, net->mtu, SCTP_CWND_LOG_FROM_SS);
1605 net->cwnd += net->net_ack;
1606 if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_CWND_MONITOR_ENABLE) {
1607 sctp_log_cwnd(stcb, net, net->net_ack, SCTP_CWND_LOG_FROM_SS);
1611 for (i = net->last_hs_used; i < SCTP_HS_TABLE_SIZE; i++) {
1612 if (cur_val < sctp_cwnd_adjust[i].cwnd) {
1617 net->last_hs_used = indx;
1618 incr = ((sctp_cwnd_adjust[indx].increase) << 10);
1620 if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_CWND_MONITOR_ENABLE) {
1621 sctp_log_cwnd(stcb, net, incr, SCTP_CWND_LOG_FROM_SS);
1627 sctp_hs_cwnd_decrease(struct sctp_tcb *stcb, struct sctp_nets *net)
1629 int cur_val, i, indx;
1630 int old_cwnd = net->cwnd;
1632 cur_val = net->cwnd >> 10;
1633 if (cur_val < sctp_cwnd_adjust[0].cwnd) {
1635 net->ssthresh = net->cwnd / 2;
1636 if (net->ssthresh < (net->mtu * 2)) {
1637 net->ssthresh = 2 * net->mtu;
1639 net->cwnd = net->ssthresh;
1641 /* drop by the proper amount */
1642 net->ssthresh = net->cwnd - (int)((net->cwnd / 100) *
1643 sctp_cwnd_adjust[net->last_hs_used].drop_percent);
1644 net->cwnd = net->ssthresh;
1645 /* now where are we */
1646 indx = net->last_hs_used;
1647 cur_val = net->cwnd >> 10;
1648 /* reset where we are in the table */
1649 if (cur_val < sctp_cwnd_adjust[0].cwnd) {
1650 /* feel out of hs */
1651 net->last_hs_used = 0;
1653 for (i = indx; i >= 1; i--) {
1654 if (cur_val > sctp_cwnd_adjust[i - 1].cwnd) {
1658 net->last_hs_used = indx;
1661 if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_CWND_MONITOR_ENABLE) {
1662 sctp_log_cwnd(stcb, net, (net->cwnd - old_cwnd), SCTP_CWND_LOG_FROM_FR);
1667 sctp_hs_cwnd_update_after_fr(struct sctp_tcb *stcb,
1668 struct sctp_association *asoc)
1670 struct sctp_nets *net;
1673 * CMT fast recovery code. Need to debug. ((sctp_cmt_on_off > 0) &&
1674 * (net->fast_retran_loss_recovery == 0)))
1676 TAILQ_FOREACH(net, &asoc->nets, sctp_next) {
1677 if ((asoc->fast_retran_loss_recovery == 0) ||
1678 (asoc->sctp_cmt_on_off > 0)) {
1679 /* out of a RFC2582 Fast recovery window? */
1680 if (net->net_ack > 0) {
1682 * per section 7.2.3, are there any
1683 * destinations that had a fast retransmit
1684 * to them. If so what we need to do is
1685 * adjust ssthresh and cwnd.
1687 struct sctp_tmit_chunk *lchk;
1689 sctp_hs_cwnd_decrease(stcb, net);
1691 lchk = TAILQ_FIRST(&asoc->send_queue);
1693 net->partial_bytes_acked = 0;
1694 /* Turn on fast recovery window */
1695 asoc->fast_retran_loss_recovery = 1;
1697 /* Mark end of the window */
1698 asoc->fast_recovery_tsn = asoc->sending_seq - 1;
1700 asoc->fast_recovery_tsn = lchk->rec.data.TSN_seq - 1;
1704 * CMT fast recovery -- per destination
1705 * recovery variable.
1707 net->fast_retran_loss_recovery = 1;
1710 /* Mark end of the window */
1711 net->fast_recovery_tsn = asoc->sending_seq - 1;
1713 net->fast_recovery_tsn = lchk->rec.data.TSN_seq - 1;
1716 sctp_timer_stop(SCTP_TIMER_TYPE_SEND,
1717 stcb->sctp_ep, stcb, net, SCTP_FROM_SCTP_INDATA + SCTP_LOC_32);
1718 sctp_timer_start(SCTP_TIMER_TYPE_SEND,
1719 stcb->sctp_ep, stcb, net);
1721 } else if (net->net_ack > 0) {
1723 * Mark a peg that we WOULD have done a cwnd
1724 * reduction but RFC2582 prevented this action.
1726 SCTP_STAT_INCR(sctps_fastretransinrtt);
1732 sctp_hs_cwnd_update_after_sack(struct sctp_tcb *stcb,
1733 struct sctp_association *asoc,
1734 int accum_moved, int reneged_all, int will_exit)
1736 struct sctp_nets *net;
1738 /******************************/
1739 /* update cwnd and Early FR */
1740 /******************************/
1741 TAILQ_FOREACH(net, &asoc->nets, sctp_next) {
1743 #ifdef JANA_CMT_FAST_RECOVERY
1745 * CMT fast recovery code. Need to debug.
1747 if (net->fast_retran_loss_recovery && net->new_pseudo_cumack) {
1748 if (SCTP_TSN_GE(asoc->last_acked_seq, net->fast_recovery_tsn) ||
1749 SCTP_TSN_GE(net->pseudo_cumack, net->fast_recovery_tsn)) {
1750 net->will_exit_fast_recovery = 1;
1754 /* if nothing was acked on this destination skip it */
1755 if (net->net_ack == 0) {
1756 if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_CWND_LOGGING_ENABLE) {
1757 sctp_log_cwnd(stcb, net, 0, SCTP_CWND_LOG_FROM_SACK);
1761 #ifdef JANA_CMT_FAST_RECOVERY
1763 * CMT fast recovery code
1766 * if (sctp_cmt_on_off > 0 && net->fast_retran_loss_recovery
1767 * && net->will_exit_fast_recovery == 0) { @@@ Do something
1768 * } else if (sctp_cmt_on_off == 0 &&
1769 * asoc->fast_retran_loss_recovery && will_exit == 0) {
1773 if (asoc->fast_retran_loss_recovery &&
1775 (asoc->sctp_cmt_on_off == 0)) {
1777 * If we are in loss recovery we skip any cwnd
1783 * CMT: CUC algorithm. Update cwnd if pseudo-cumack has
1787 ((asoc->sctp_cmt_on_off > 0) && net->new_pseudo_cumack)) {
1788 /* If the cumulative ack moved we can proceed */
1789 if (net->cwnd <= net->ssthresh) {
1790 /* We are in slow start */
1791 if (net->flight_size + net->net_ack >= net->cwnd) {
1793 sctp_hs_cwnd_increase(stcb, net);
1796 if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_CWND_LOGGING_ENABLE) {
1797 sctp_log_cwnd(stcb, net, net->net_ack,
1798 SCTP_CWND_LOG_NOADV_SS);
1802 /* We are in congestion avoidance */
1803 net->partial_bytes_acked += net->net_ack;
1804 if ((net->flight_size + net->net_ack >= net->cwnd) &&
1805 (net->partial_bytes_acked >= net->cwnd)) {
1806 net->partial_bytes_acked -= net->cwnd;
1807 net->cwnd += net->mtu;
1808 if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_CWND_MONITOR_ENABLE) {
1809 sctp_log_cwnd(stcb, net, net->mtu,
1810 SCTP_CWND_LOG_FROM_CA);
1813 if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_CWND_LOGGING_ENABLE) {
1814 sctp_log_cwnd(stcb, net, net->net_ack,
1815 SCTP_CWND_LOG_NOADV_CA);
1820 if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_CWND_LOGGING_ENABLE) {
1821 sctp_log_cwnd(stcb, net, net->mtu,
1822 SCTP_CWND_LOG_NO_CUMACK);
1830 * H-TCP congestion control. The algorithm is detailed in:
1831 * R.N.Shorten, D.J.Leith:
1832 * "H-TCP: TCP for high-speed and long-distance networks"
1833 * Proc. PFLDnet, Argonne, 2004.
1834 * http://www.hamilton.ie/net/htcp3.pdf
1838 static int use_rtt_scaling = 1;
1839 static int use_bandwidth_switch = 1;
1842 between(uint32_t seq1, uint32_t seq2, uint32_t seq3)
1844 return seq3 - seq2 >= seq1 - seq2;
1847 static inline uint32_t
1848 htcp_cong_time(struct htcp *ca)
1850 return sctp_get_tick_count() - ca->last_cong;
1853 static inline uint32_t
1854 htcp_ccount(struct htcp *ca)
1856 return htcp_cong_time(ca) / ca->minRTT;
1860 htcp_reset(struct htcp *ca)
1862 ca->undo_last_cong = ca->last_cong;
1863 ca->undo_maxRTT = ca->maxRTT;
1864 ca->undo_old_maxB = ca->old_maxB;
1865 ca->last_cong = sctp_get_tick_count();
1868 #ifdef SCTP_NOT_USED
1871 htcp_cwnd_undo(struct sctp_tcb *stcb, struct sctp_nets *net)
1873 net->cc_mod.htcp_ca.last_cong = net->cc_mod.htcp_ca.undo_last_cong;
1874 net->cc_mod.htcp_ca.maxRTT = net->cc_mod.htcp_ca.undo_maxRTT;
1875 net->cc_mod.htcp_ca.old_maxB = net->cc_mod.htcp_ca.undo_old_maxB;
1876 return max(net->cwnd, ((net->ssthresh / net->mtu << 7) / net->cc_mod.htcp_ca.beta) * net->mtu);
1882 measure_rtt(struct sctp_tcb *stcb, struct sctp_nets *net)
1884 uint32_t srtt = net->lastsa >> SCTP_RTT_SHIFT;
1886 /* keep track of minimum RTT seen so far, minRTT is zero at first */
1887 if (net->cc_mod.htcp_ca.minRTT > srtt || !net->cc_mod.htcp_ca.minRTT)
1888 net->cc_mod.htcp_ca.minRTT = srtt;
1891 if (net->fast_retran_ip == 0 && net->ssthresh < 0xFFFF && htcp_ccount(&net->cc_mod.htcp_ca) > 3) {
1892 if (net->cc_mod.htcp_ca.maxRTT < net->cc_mod.htcp_ca.minRTT)
1893 net->cc_mod.htcp_ca.maxRTT = net->cc_mod.htcp_ca.minRTT;
1894 if (net->cc_mod.htcp_ca.maxRTT < srtt && srtt <= net->cc_mod.htcp_ca.maxRTT + MSEC_TO_TICKS(20))
1895 net->cc_mod.htcp_ca.maxRTT = srtt;
1900 measure_achieved_throughput(struct sctp_tcb *stcb, struct sctp_nets *net)
1902 uint32_t now = sctp_get_tick_count();
1904 if (net->fast_retran_ip == 0)
1905 net->cc_mod.htcp_ca.bytes_acked = net->net_ack;
1907 if (!use_bandwidth_switch)
1910 /* achieved throughput calculations */
1911 /* JRS - not 100% sure of this statement */
1912 if (net->fast_retran_ip == 1) {
1913 net->cc_mod.htcp_ca.bytecount = 0;
1914 net->cc_mod.htcp_ca.lasttime = now;
1917 net->cc_mod.htcp_ca.bytecount += net->net_ack;
1919 if (net->cc_mod.htcp_ca.bytecount >= net->cwnd - ((net->cc_mod.htcp_ca.alpha >> 7 ? : 1) * net->mtu)
1920 && now - net->cc_mod.htcp_ca.lasttime >= net->cc_mod.htcp_ca.minRTT
1921 && net->cc_mod.htcp_ca.minRTT > 0) {
1922 uint32_t cur_Bi = net->cc_mod.htcp_ca.bytecount / net->mtu * hz / (now - net->cc_mod.htcp_ca.lasttime);
1924 if (htcp_ccount(&net->cc_mod.htcp_ca) <= 3) {
1925 /* just after backoff */
1926 net->cc_mod.htcp_ca.minB = net->cc_mod.htcp_ca.maxB = net->cc_mod.htcp_ca.Bi = cur_Bi;
1928 net->cc_mod.htcp_ca.Bi = (3 * net->cc_mod.htcp_ca.Bi + cur_Bi) / 4;
1929 if (net->cc_mod.htcp_ca.Bi > net->cc_mod.htcp_ca.maxB)
1930 net->cc_mod.htcp_ca.maxB = net->cc_mod.htcp_ca.Bi;
1931 if (net->cc_mod.htcp_ca.minB > net->cc_mod.htcp_ca.maxB)
1932 net->cc_mod.htcp_ca.minB = net->cc_mod.htcp_ca.maxB;
1934 net->cc_mod.htcp_ca.bytecount = 0;
1935 net->cc_mod.htcp_ca.lasttime = now;
1940 htcp_beta_update(struct htcp *ca, uint32_t minRTT, uint32_t maxRTT)
1942 if (use_bandwidth_switch) {
1943 uint32_t maxB = ca->maxB;
1944 uint32_t old_maxB = ca->old_maxB;
1946 ca->old_maxB = ca->maxB;
1948 if (!between(5 * maxB, 4 * old_maxB, 6 * old_maxB)) {
1949 ca->beta = BETA_MIN;
1954 if (ca->modeswitch && minRTT > (uint32_t) MSEC_TO_TICKS(10) && maxRTT) {
1955 ca->beta = (minRTT << 7) / maxRTT;
1956 if (ca->beta < BETA_MIN)
1957 ca->beta = BETA_MIN;
1958 else if (ca->beta > BETA_MAX)
1959 ca->beta = BETA_MAX;
1961 ca->beta = BETA_MIN;
1967 htcp_alpha_update(struct htcp *ca)
1969 uint32_t minRTT = ca->minRTT;
1970 uint32_t factor = 1;
1971 uint32_t diff = htcp_cong_time(ca);
1973 if (diff > (uint32_t) hz) {
1975 factor = 1 + (10 * diff + ((diff / 2) * (diff / 2) / hz)) / hz;
1977 if (use_rtt_scaling && minRTT) {
1978 uint32_t scale = (hz << 3) / (10 * minRTT);
1980 scale = min(max(scale, 1U << 2), 10U << 3); /* clamping ratio to
1981 * interval [0.5,10]<<3 */
1982 factor = (factor << 3) / scale;
1986 ca->alpha = 2 * factor * ((1 << 7) - ca->beta);
1988 ca->alpha = ALPHA_BASE;
1991 /* After we have the rtt data to calculate beta, we'd still prefer to wait one
1992 * rtt before we adjust our beta to ensure we are working from a consistent
1995 * This function should be called when we hit a congestion event since only at
1996 * that point do we really have a real sense of maxRTT (the queues en route
1997 * were getting just too full now).
2000 htcp_param_update(struct sctp_tcb *stcb, struct sctp_nets *net)
2002 uint32_t minRTT = net->cc_mod.htcp_ca.minRTT;
2003 uint32_t maxRTT = net->cc_mod.htcp_ca.maxRTT;
2005 htcp_beta_update(&net->cc_mod.htcp_ca, minRTT, maxRTT);
2006 htcp_alpha_update(&net->cc_mod.htcp_ca);
2009 * add slowly fading memory for maxRTT to accommodate routing
2012 if (minRTT > 0 && maxRTT > minRTT)
2013 net->cc_mod.htcp_ca.maxRTT = minRTT + ((maxRTT - minRTT) * 95) / 100;
2017 htcp_recalc_ssthresh(struct sctp_tcb *stcb, struct sctp_nets *net)
2019 htcp_param_update(stcb, net);
2020 return max(((net->cwnd / net->mtu * net->cc_mod.htcp_ca.beta) >> 7) * net->mtu, 2U * net->mtu);
2024 htcp_cong_avoid(struct sctp_tcb *stcb, struct sctp_nets *net)
2027 * How to handle these functions?
2028 * if (!tcp_is_cwnd_limited(sk, in_flight)) RRS - good question.
2031 if (net->cwnd <= net->ssthresh) {
2032 /* We are in slow start */
2033 if (net->flight_size + net->net_ack >= net->cwnd) {
2034 if (net->net_ack > (net->mtu * SCTP_BASE_SYSCTL(sctp_L2_abc_variable))) {
2035 net->cwnd += (net->mtu * SCTP_BASE_SYSCTL(sctp_L2_abc_variable));
2036 if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_CWND_MONITOR_ENABLE) {
2037 sctp_log_cwnd(stcb, net, net->mtu,
2038 SCTP_CWND_LOG_FROM_SS);
2041 net->cwnd += net->net_ack;
2042 if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_CWND_MONITOR_ENABLE) {
2043 sctp_log_cwnd(stcb, net, net->net_ack,
2044 SCTP_CWND_LOG_FROM_SS);
2048 if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_CWND_LOGGING_ENABLE) {
2049 sctp_log_cwnd(stcb, net, net->net_ack,
2050 SCTP_CWND_LOG_NOADV_SS);
2054 measure_rtt(stcb, net);
2057 * In dangerous area, increase slowly. In theory this is
2058 * net->cwnd += alpha / net->cwnd
2060 /* What is snd_cwnd_cnt?? */
2061 if (((net->partial_bytes_acked / net->mtu * net->cc_mod.htcp_ca.alpha) >> 7) * net->mtu >= net->cwnd) {
2063 * Does SCTP have a cwnd clamp?
2064 * if (net->snd_cwnd < net->snd_cwnd_clamp) - Nope (RRS).
2066 net->cwnd += net->mtu;
2067 net->partial_bytes_acked = 0;
2068 htcp_alpha_update(&net->cc_mod.htcp_ca);
2069 if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_CWND_MONITOR_ENABLE) {
2070 sctp_log_cwnd(stcb, net, net->mtu,
2071 SCTP_CWND_LOG_FROM_CA);
2074 net->partial_bytes_acked += net->net_ack;
2075 if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_CWND_LOGGING_ENABLE) {
2076 sctp_log_cwnd(stcb, net, net->net_ack,
2077 SCTP_CWND_LOG_NOADV_CA);
2081 net->cc_mod.htcp_ca.bytes_acked = net->mtu;
2085 #ifdef SCTP_NOT_USED
2086 /* Lower bound on congestion window. */
2088 htcp_min_cwnd(struct sctp_tcb *stcb, struct sctp_nets *net)
2090 return net->ssthresh;
2096 htcp_init(struct sctp_tcb *stcb, struct sctp_nets *net)
2098 memset(&net->cc_mod.htcp_ca, 0, sizeof(struct htcp));
2099 net->cc_mod.htcp_ca.alpha = ALPHA_BASE;
2100 net->cc_mod.htcp_ca.beta = BETA_MIN;
2101 net->cc_mod.htcp_ca.bytes_acked = net->mtu;
2102 net->cc_mod.htcp_ca.last_cong = sctp_get_tick_count();
2106 sctp_htcp_set_initial_cc_param(struct sctp_tcb *stcb, struct sctp_nets *net)
2109 * We take the max of the burst limit times a MTU or the
2110 * INITIAL_CWND. We then limit this to 4 MTU's of sending.
2112 net->cwnd = min((net->mtu * 4), max((2 * net->mtu), SCTP_INITIAL_CWND));
2113 net->ssthresh = stcb->asoc.peers_rwnd;
2114 htcp_init(stcb, net);
2116 if (SCTP_BASE_SYSCTL(sctp_logging_level) & (SCTP_CWND_MONITOR_ENABLE | SCTP_CWND_LOGGING_ENABLE)) {
2117 sctp_log_cwnd(stcb, net, 0, SCTP_CWND_INITIALIZATION);
2122 sctp_htcp_cwnd_update_after_sack(struct sctp_tcb *stcb,
2123 struct sctp_association *asoc,
2124 int accum_moved, int reneged_all, int will_exit)
2126 struct sctp_nets *net;
2128 /******************************/
2129 /* update cwnd and Early FR */
2130 /******************************/
2131 TAILQ_FOREACH(net, &asoc->nets, sctp_next) {
2133 #ifdef JANA_CMT_FAST_RECOVERY
2135 * CMT fast recovery code. Need to debug.
2137 if (net->fast_retran_loss_recovery && net->new_pseudo_cumack) {
2138 if (SCTP_TSN_GE(asoc->last_acked_seq, net->fast_recovery_tsn) ||
2139 SCTP_TSN_GE(net->pseudo_cumack, net->fast_recovery_tsn)) {
2140 net->will_exit_fast_recovery = 1;
2144 /* if nothing was acked on this destination skip it */
2145 if (net->net_ack == 0) {
2146 if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_CWND_LOGGING_ENABLE) {
2147 sctp_log_cwnd(stcb, net, 0, SCTP_CWND_LOG_FROM_SACK);
2151 #ifdef JANA_CMT_FAST_RECOVERY
2153 * CMT fast recovery code
2156 * if (sctp_cmt_on_off > 0 && net->fast_retran_loss_recovery
2157 * && net->will_exit_fast_recovery == 0) { @@@ Do something
2158 * } else if (sctp_cmt_on_off == 0 &&
2159 * asoc->fast_retran_loss_recovery && will_exit == 0) {
2163 if (asoc->fast_retran_loss_recovery &&
2165 (asoc->sctp_cmt_on_off == 0)) {
2167 * If we are in loss recovery we skip any cwnd
2173 * CMT: CUC algorithm. Update cwnd if pseudo-cumack has
2177 ((asoc->sctp_cmt_on_off > 0) && net->new_pseudo_cumack)) {
2178 htcp_cong_avoid(stcb, net);
2179 measure_achieved_throughput(stcb, net);
2181 if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_CWND_LOGGING_ENABLE) {
2182 sctp_log_cwnd(stcb, net, net->mtu,
2183 SCTP_CWND_LOG_NO_CUMACK);
2190 sctp_htcp_cwnd_update_after_fr(struct sctp_tcb *stcb,
2191 struct sctp_association *asoc)
2193 struct sctp_nets *net;
2196 * CMT fast recovery code. Need to debug. ((sctp_cmt_on_off > 0) &&
2197 * (net->fast_retran_loss_recovery == 0)))
2199 TAILQ_FOREACH(net, &asoc->nets, sctp_next) {
2200 if ((asoc->fast_retran_loss_recovery == 0) ||
2201 (asoc->sctp_cmt_on_off > 0)) {
2202 /* out of a RFC2582 Fast recovery window? */
2203 if (net->net_ack > 0) {
2205 * per section 7.2.3, are there any
2206 * destinations that had a fast retransmit
2207 * to them. If so what we need to do is
2208 * adjust ssthresh and cwnd.
2210 struct sctp_tmit_chunk *lchk;
2211 int old_cwnd = net->cwnd;
2213 /* JRS - reset as if state were changed */
2214 htcp_reset(&net->cc_mod.htcp_ca);
2215 net->ssthresh = htcp_recalc_ssthresh(stcb, net);
2216 net->cwnd = net->ssthresh;
2217 if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_CWND_MONITOR_ENABLE) {
2218 sctp_log_cwnd(stcb, net, (net->cwnd - old_cwnd),
2219 SCTP_CWND_LOG_FROM_FR);
2221 lchk = TAILQ_FIRST(&asoc->send_queue);
2223 net->partial_bytes_acked = 0;
2224 /* Turn on fast recovery window */
2225 asoc->fast_retran_loss_recovery = 1;
2227 /* Mark end of the window */
2228 asoc->fast_recovery_tsn = asoc->sending_seq - 1;
2230 asoc->fast_recovery_tsn = lchk->rec.data.TSN_seq - 1;
2234 * CMT fast recovery -- per destination
2235 * recovery variable.
2237 net->fast_retran_loss_recovery = 1;
2240 /* Mark end of the window */
2241 net->fast_recovery_tsn = asoc->sending_seq - 1;
2243 net->fast_recovery_tsn = lchk->rec.data.TSN_seq - 1;
2246 sctp_timer_stop(SCTP_TIMER_TYPE_SEND,
2247 stcb->sctp_ep, stcb, net, SCTP_FROM_SCTP_INDATA + SCTP_LOC_32);
2248 sctp_timer_start(SCTP_TIMER_TYPE_SEND,
2249 stcb->sctp_ep, stcb, net);
2251 } else if (net->net_ack > 0) {
2253 * Mark a peg that we WOULD have done a cwnd
2254 * reduction but RFC2582 prevented this action.
2256 SCTP_STAT_INCR(sctps_fastretransinrtt);
2262 sctp_htcp_cwnd_update_after_timeout(struct sctp_tcb *stcb,
2263 struct sctp_nets *net)
2265 int old_cwnd = net->cwnd;
2267 /* JRS - reset as if the state were being changed to timeout */
2268 htcp_reset(&net->cc_mod.htcp_ca);
2269 net->ssthresh = htcp_recalc_ssthresh(stcb, net);
2270 net->cwnd = net->mtu;
2271 net->partial_bytes_acked = 0;
2272 if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_CWND_MONITOR_ENABLE) {
2273 sctp_log_cwnd(stcb, net, net->cwnd - old_cwnd, SCTP_CWND_LOG_FROM_RTX);
2278 sctp_htcp_cwnd_update_after_ecn_echo(struct sctp_tcb *stcb,
2279 struct sctp_nets *net, int in_window, int num_pkt_lost)
2283 old_cwnd = net->cwnd;
2285 /* JRS - reset hctp as if state changed */
2286 if (in_window == 0) {
2287 htcp_reset(&net->cc_mod.htcp_ca);
2288 SCTP_STAT_INCR(sctps_ecnereducedcwnd);
2289 net->ssthresh = htcp_recalc_ssthresh(stcb, net);
2290 if (net->ssthresh < net->mtu) {
2291 net->ssthresh = net->mtu;
2292 /* here back off the timer as well, to slow us down */
2295 net->cwnd = net->ssthresh;
2296 if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_CWND_MONITOR_ENABLE) {
2297 sctp_log_cwnd(stcb, net, (net->cwnd - old_cwnd), SCTP_CWND_LOG_FROM_SAT);
2302 struct sctp_cc_functions sctp_cc_functions[] = {
2304 .sctp_set_initial_cc_param = sctp_set_initial_cc_param,
2305 .sctp_cwnd_update_after_sack = sctp_cwnd_update_after_sack,
2306 .sctp_cwnd_update_exit_pf = sctp_cwnd_update_exit_pf_common,
2307 .sctp_cwnd_update_after_fr = sctp_cwnd_update_after_fr,
2308 .sctp_cwnd_update_after_timeout = sctp_cwnd_update_after_timeout,
2309 .sctp_cwnd_update_after_ecn_echo = sctp_cwnd_update_after_ecn_echo,
2310 .sctp_cwnd_update_after_packet_dropped = sctp_cwnd_update_after_packet_dropped,
2311 .sctp_cwnd_update_after_output = sctp_cwnd_update_after_output,
2314 .sctp_set_initial_cc_param = sctp_set_initial_cc_param,
2315 .sctp_cwnd_update_after_sack = sctp_hs_cwnd_update_after_sack,
2316 .sctp_cwnd_update_exit_pf = sctp_cwnd_update_exit_pf_common,
2317 .sctp_cwnd_update_after_fr = sctp_hs_cwnd_update_after_fr,
2318 .sctp_cwnd_update_after_timeout = sctp_cwnd_update_after_timeout,
2319 .sctp_cwnd_update_after_ecn_echo = sctp_cwnd_update_after_ecn_echo,
2320 .sctp_cwnd_update_after_packet_dropped = sctp_cwnd_update_after_packet_dropped,
2321 .sctp_cwnd_update_after_output = sctp_cwnd_update_after_output,
2324 .sctp_set_initial_cc_param = sctp_htcp_set_initial_cc_param,
2325 .sctp_cwnd_update_after_sack = sctp_htcp_cwnd_update_after_sack,
2326 .sctp_cwnd_update_exit_pf = sctp_cwnd_update_exit_pf_common,
2327 .sctp_cwnd_update_after_fr = sctp_htcp_cwnd_update_after_fr,
2328 .sctp_cwnd_update_after_timeout = sctp_htcp_cwnd_update_after_timeout,
2329 .sctp_cwnd_update_after_ecn_echo = sctp_htcp_cwnd_update_after_ecn_echo,
2330 .sctp_cwnd_update_after_packet_dropped = sctp_cwnd_update_after_packet_dropped,
2331 .sctp_cwnd_update_after_output = sctp_cwnd_update_after_output,
2334 .sctp_set_initial_cc_param = sctp_set_rtcc_initial_cc_param,
2335 .sctp_cwnd_update_after_sack = sctp_cwnd_update_rtcc_after_sack,
2336 .sctp_cwnd_update_exit_pf = sctp_cwnd_update_exit_pf_common,
2337 .sctp_cwnd_update_after_fr = sctp_cwnd_update_after_fr,
2338 .sctp_cwnd_update_after_timeout = sctp_cwnd_update_after_timeout,
2339 .sctp_cwnd_update_after_ecn_echo = sctp_cwnd_update_rtcc_after_ecn_echo,
2340 .sctp_cwnd_update_after_packet_dropped = sctp_cwnd_update_after_packet_dropped,
2341 .sctp_cwnd_update_after_output = sctp_cwnd_update_after_output,
2342 .sctp_cwnd_update_packet_transmitted = sctp_cwnd_update_rtcc_packet_transmitted,
2343 .sctp_cwnd_update_tsn_acknowledged = sctp_cwnd_update_rtcc_tsn_acknowledged,
2344 .sctp_cwnd_new_transmission_begins = sctp_cwnd_new_rtcc_transmission_begins,
2345 .sctp_cwnd_prepare_net_for_sack = sctp_cwnd_prepare_rtcc_net_for_sack,
2346 .sctp_cwnd_socket_option = sctp_cwnd_rtcc_socket_option,
2347 .sctp_rtt_calculated = sctp_rtt_rtcc_calculated