1 /*- 2 * SPDX-License-Identifier: BSD-3-Clause 3 * 4 * Copyright (c) 2001-2007, by Cisco Systems, Inc. All rights reserved. 5 * Copyright (c) 2008-2012, by Randall Stewart. All rights reserved. 6 * Copyright (c) 2008-2012, by Michael Tuexen. All rights reserved. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions are met: 10 * 11 * a) Redistributions of source code must retain the above copyright notice, 12 * this list of conditions and the following disclaimer. 13 * 14 * b) Redistributions in binary form must reproduce the above copyright 15 * notice, this list of conditions and the following disclaimer in 16 * the documentation and/or other materials provided with the distribution. 17 * 18 * c) Neither the name of Cisco Systems, Inc. nor the names of its 19 * contributors may be used to endorse or promote products derived 20 * from this software without specific prior written permission. 21 * 22 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 23 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, 24 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 25 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE 26 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 27 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 28 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 29 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 30 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 31 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF 32 * THE POSSIBILITY OF SUCH DAMAGE. 33 */ 34 35 #include <netinet/sctp_os.h> 36 #include <netinet/sctp_var.h> 37 #include <netinet/sctp_sysctl.h> 38 #include <netinet/sctp_pcb.h> 39 #include <netinet/sctp_header.h> 40 #include <netinet/sctputil.h> 41 #include <netinet/sctp_output.h> 42 #include <netinet/sctp_input.h> 43 #include <netinet/sctp_indata.h> 44 #include <netinet/sctp_uio.h> 45 #include <netinet/sctp_timer.h> 46 #include <netinet/sctp_auth.h> 47 #include <netinet/sctp_asconf.h> 48 #include <netinet/sctp_kdtrace.h> 49 50 #define SHIFT_MPTCP_MULTI_N 40 51 #define SHIFT_MPTCP_MULTI_Z 16 52 #define SHIFT_MPTCP_MULTI 8 53 54 static void 55 sctp_enforce_cwnd_limit(struct sctp_association *assoc, struct sctp_nets *net) 56 { 57 if ((assoc->max_cwnd > 0) && 58 (net->cwnd > assoc->max_cwnd) && 59 (net->cwnd > (net->mtu - sizeof(struct sctphdr)))) { 60 net->cwnd = assoc->max_cwnd; 61 if (net->cwnd < (net->mtu - sizeof(struct sctphdr))) { 62 net->cwnd = net->mtu - sizeof(struct sctphdr); 63 } 64 } 65 } 66 67 static void 68 sctp_set_initial_cc_param(struct sctp_tcb *stcb, struct sctp_nets *net) 69 { 70 struct sctp_association *assoc; 71 uint32_t cwnd_in_mtu; 72 73 assoc = &stcb->asoc; 74 cwnd_in_mtu = SCTP_BASE_SYSCTL(sctp_initial_cwnd); 75 if (cwnd_in_mtu == 0) { 76 /* Using 0 means that the value of RFC 4960 is used. */ 77 net->cwnd = min((net->mtu * 4), max((2 * net->mtu), SCTP_INITIAL_CWND)); 78 } else { 79 /* 80 * We take the minimum of the burst limit and the initial 81 * congestion window. 82 */ 83 if ((assoc->max_burst > 0) && (cwnd_in_mtu > assoc->max_burst)) 84 cwnd_in_mtu = assoc->max_burst; 85 net->cwnd = (net->mtu - sizeof(struct sctphdr)) * cwnd_in_mtu; 86 } 87 if ((stcb->asoc.sctp_cmt_on_off == SCTP_CMT_RPV1) || 88 (stcb->asoc.sctp_cmt_on_off == SCTP_CMT_RPV2)) { 89 /* In case of resource pooling initialize appropriately */ 90 net->cwnd /= assoc->numnets; 91 if (net->cwnd < (net->mtu - sizeof(struct sctphdr))) { 92 net->cwnd = net->mtu - sizeof(struct sctphdr); 93 } 94 } 95 sctp_enforce_cwnd_limit(assoc, net); 96 net->ssthresh = assoc->peers_rwnd; 97 SDT_PROBE5(sctp, cwnd, net, init, 98 stcb->asoc.my_vtag, ((stcb->sctp_ep->sctp_lport << 16) | (stcb->rport)), net, 99 0, net->cwnd); 100 if (SCTP_BASE_SYSCTL(sctp_logging_level) & 101 (SCTP_CWND_MONITOR_ENABLE | SCTP_CWND_LOGGING_ENABLE)) { 102 sctp_log_cwnd(stcb, net, 0, SCTP_CWND_INITIALIZATION); 103 } 104 } 105 106 static void 107 sctp_cwnd_update_after_fr(struct sctp_tcb *stcb, 108 struct sctp_association *asoc) 109 { 110 struct sctp_nets *net; 111 uint32_t t_ssthresh, t_cwnd; 112 uint64_t t_ucwnd_sbw; 113 114 /* MT FIXME: Don't compute this over and over again */ 115 t_ssthresh = 0; 116 t_cwnd = 0; 117 t_ucwnd_sbw = 0; 118 if ((asoc->sctp_cmt_on_off == SCTP_CMT_RPV1) || 119 (asoc->sctp_cmt_on_off == SCTP_CMT_RPV2)) { 120 TAILQ_FOREACH(net, &asoc->nets, sctp_next) { 121 t_ssthresh += net->ssthresh; 122 t_cwnd += net->cwnd; 123 if (net->lastsa > 0) { 124 t_ucwnd_sbw += (uint64_t)net->cwnd / (uint64_t)net->lastsa; 125 } 126 } 127 if (t_ucwnd_sbw == 0) { 128 t_ucwnd_sbw = 1; 129 } 130 } 131 132 /*- 133 * CMT fast recovery code. Need to debug. ((sctp_cmt_on_off > 0) && 134 * (net->fast_retran_loss_recovery == 0))) 135 */ 136 TAILQ_FOREACH(net, &asoc->nets, sctp_next) { 137 if ((asoc->fast_retran_loss_recovery == 0) || 138 (asoc->sctp_cmt_on_off > 0)) { 139 /* out of a RFC2582 Fast recovery window? */ 140 if (net->net_ack > 0) { 141 /* 142 * per section 7.2.3, are there any 143 * destinations that had a fast retransmit 144 * to them. If so what we need to do is 145 * adjust ssthresh and cwnd. 146 */ 147 struct sctp_tmit_chunk *lchk; 148 int old_cwnd = net->cwnd; 149 150 if ((asoc->sctp_cmt_on_off == SCTP_CMT_RPV1) || 151 (asoc->sctp_cmt_on_off == SCTP_CMT_RPV2)) { 152 if (asoc->sctp_cmt_on_off == SCTP_CMT_RPV1) { 153 net->ssthresh = (uint32_t)(((uint64_t)4 * 154 (uint64_t)net->mtu * 155 (uint64_t)net->ssthresh) / 156 (uint64_t)t_ssthresh); 157 } 158 if (asoc->sctp_cmt_on_off == SCTP_CMT_RPV2) { 159 uint32_t srtt; 160 161 srtt = net->lastsa; 162 /* 163 * lastsa>>3; we don't need 164 * to devide ... 165 */ 166 if (srtt == 0) { 167 srtt = 1; 168 } 169 /* 170 * Short Version => Equal to 171 * Contel Version MBe 172 */ 173 net->ssthresh = (uint32_t)(((uint64_t)4 * 174 (uint64_t)net->mtu * 175 (uint64_t)net->cwnd) / 176 ((uint64_t)srtt * 177 t_ucwnd_sbw)); 178 /* INCREASE FACTOR */ ; 179 } 180 if ((net->cwnd > t_cwnd / 2) && 181 (net->ssthresh < net->cwnd - t_cwnd / 2)) { 182 net->ssthresh = net->cwnd - t_cwnd / 2; 183 } 184 if (net->ssthresh < net->mtu) { 185 net->ssthresh = net->mtu; 186 } 187 } else { 188 net->ssthresh = net->cwnd / 2; 189 if (net->ssthresh < (net->mtu * 2)) { 190 net->ssthresh = 2 * net->mtu; 191 } 192 } 193 net->cwnd = net->ssthresh; 194 sctp_enforce_cwnd_limit(asoc, net); 195 SDT_PROBE5(sctp, cwnd, net, fr, 196 stcb->asoc.my_vtag, ((stcb->sctp_ep->sctp_lport << 16) | (stcb->rport)), net, 197 old_cwnd, net->cwnd); 198 if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_CWND_MONITOR_ENABLE) { 199 sctp_log_cwnd(stcb, net, (net->cwnd - old_cwnd), 200 SCTP_CWND_LOG_FROM_FR); 201 } 202 lchk = TAILQ_FIRST(&asoc->send_queue); 203 204 net->partial_bytes_acked = 0; 205 /* Turn on fast recovery window */ 206 asoc->fast_retran_loss_recovery = 1; 207 if (lchk == NULL) { 208 /* Mark end of the window */ 209 asoc->fast_recovery_tsn = asoc->sending_seq - 1; 210 } else { 211 asoc->fast_recovery_tsn = lchk->rec.data.tsn - 1; 212 } 213 214 /* 215 * CMT fast recovery -- per destination 216 * recovery variable. 217 */ 218 net->fast_retran_loss_recovery = 1; 219 220 if (lchk == NULL) { 221 /* Mark end of the window */ 222 net->fast_recovery_tsn = asoc->sending_seq - 1; 223 } else { 224 net->fast_recovery_tsn = lchk->rec.data.tsn - 1; 225 } 226 227 sctp_timer_stop(SCTP_TIMER_TYPE_SEND, 228 stcb->sctp_ep, stcb, net, 229 SCTP_FROM_SCTP_CC_FUNCTIONS + SCTP_LOC_1); 230 sctp_timer_start(SCTP_TIMER_TYPE_SEND, 231 stcb->sctp_ep, stcb, net); 232 } 233 } else if (net->net_ack > 0) { 234 /* 235 * Mark a peg that we WOULD have done a cwnd 236 * reduction but RFC2582 prevented this action. 237 */ 238 SCTP_STAT_INCR(sctps_fastretransinrtt); 239 } 240 } 241 } 242 243 /* Defines for instantaneous bw decisions */ 244 #define SCTP_INST_LOOSING 1 /* Losing to other flows */ 245 #define SCTP_INST_NEUTRAL 2 /* Neutral, no indication */ 246 #define SCTP_INST_GAINING 3 /* Gaining, step down possible */ 247 248 static int 249 cc_bw_same(struct sctp_tcb *stcb, struct sctp_nets *net, uint64_t nbw, 250 uint64_t rtt_offset, uint64_t vtag, uint8_t inst_ind) 251 { 252 uint64_t oth __sdt_used, probepoint __sdt_used; 253 254 probepoint = (((uint64_t)net->cwnd) << 32); 255 if (net->rtt > net->cc_mod.rtcc.lbw_rtt + rtt_offset) { 256 /* 257 * rtt increased we don't update bw.. so we don't update the 258 * rtt either. 259 */ 260 /* Probe point 5 */ 261 probepoint |= ((5 << 16) | 1); 262 SDT_PROBE5(sctp, cwnd, net, rttvar, 263 vtag, 264 ((net->cc_mod.rtcc.lbw << 32) | nbw), 265 ((net->cc_mod.rtcc.lbw_rtt << 32) | net->rtt), 266 net->flight_size, 267 probepoint); 268 if ((net->cc_mod.rtcc.steady_step) && (inst_ind != SCTP_INST_LOOSING)) { 269 if (net->cc_mod.rtcc.last_step_state == 5) 270 net->cc_mod.rtcc.step_cnt++; 271 else 272 net->cc_mod.rtcc.step_cnt = 1; 273 net->cc_mod.rtcc.last_step_state = 5; 274 if ((net->cc_mod.rtcc.step_cnt == net->cc_mod.rtcc.steady_step) || 275 ((net->cc_mod.rtcc.step_cnt > net->cc_mod.rtcc.steady_step) && 276 ((net->cc_mod.rtcc.step_cnt % net->cc_mod.rtcc.steady_step) == 0))) { 277 /* Try a step down */ 278 oth = net->cc_mod.rtcc.vol_reduce; 279 oth <<= 16; 280 oth |= net->cc_mod.rtcc.step_cnt; 281 oth <<= 16; 282 oth |= net->cc_mod.rtcc.last_step_state; 283 SDT_PROBE5(sctp, cwnd, net, rttstep, 284 vtag, 285 ((net->cc_mod.rtcc.lbw << 32) | nbw), 286 ((net->cc_mod.rtcc.lbw_rtt << 32) | net->rtt), 287 oth, 288 probepoint); 289 if (net->cwnd > (4 * net->mtu)) { 290 net->cwnd -= net->mtu; 291 net->cc_mod.rtcc.vol_reduce++; 292 } else { 293 net->cc_mod.rtcc.step_cnt = 0; 294 } 295 } 296 } 297 return (1); 298 } 299 if (net->rtt < net->cc_mod.rtcc.lbw_rtt - rtt_offset) { 300 /* 301 * rtt decreased, there could be more room. we update both 302 * the bw and the rtt here to lock this in as a good step 303 * down. 304 */ 305 /* Probe point 6 */ 306 probepoint |= ((6 << 16) | 0); 307 SDT_PROBE5(sctp, cwnd, net, rttvar, 308 vtag, 309 ((net->cc_mod.rtcc.lbw << 32) | nbw), 310 ((net->cc_mod.rtcc.lbw_rtt << 32) | net->rtt), 311 net->flight_size, 312 probepoint); 313 if (net->cc_mod.rtcc.steady_step) { 314 oth = net->cc_mod.rtcc.vol_reduce; 315 oth <<= 16; 316 oth |= net->cc_mod.rtcc.step_cnt; 317 oth <<= 16; 318 oth |= net->cc_mod.rtcc.last_step_state; 319 SDT_PROBE5(sctp, cwnd, net, rttstep, 320 vtag, 321 ((net->cc_mod.rtcc.lbw << 32) | nbw), 322 ((net->cc_mod.rtcc.lbw_rtt << 32) | net->rtt), 323 oth, 324 probepoint); 325 if ((net->cc_mod.rtcc.last_step_state == 5) && 326 (net->cc_mod.rtcc.step_cnt > net->cc_mod.rtcc.steady_step)) { 327 /* Step down worked */ 328 net->cc_mod.rtcc.step_cnt = 0; 329 return (1); 330 } else { 331 net->cc_mod.rtcc.last_step_state = 6; 332 net->cc_mod.rtcc.step_cnt = 0; 333 } 334 } 335 net->cc_mod.rtcc.lbw = nbw; 336 net->cc_mod.rtcc.lbw_rtt = net->rtt; 337 net->cc_mod.rtcc.cwnd_at_bw_set = net->cwnd; 338 if (inst_ind == SCTP_INST_GAINING) 339 return (1); 340 else if (inst_ind == SCTP_INST_NEUTRAL) 341 return (1); 342 else 343 return (0); 344 } 345 /* 346 * Ok bw and rtt remained the same .. no update to any 347 */ 348 /* Probe point 7 */ 349 probepoint |= ((7 << 16) | net->cc_mod.rtcc.ret_from_eq); 350 SDT_PROBE5(sctp, cwnd, net, rttvar, 351 vtag, 352 ((net->cc_mod.rtcc.lbw << 32) | nbw), 353 ((net->cc_mod.rtcc.lbw_rtt << 32) | net->rtt), 354 net->flight_size, 355 probepoint); 356 if ((net->cc_mod.rtcc.steady_step) && (inst_ind != SCTP_INST_LOOSING)) { 357 if (net->cc_mod.rtcc.last_step_state == 5) 358 net->cc_mod.rtcc.step_cnt++; 359 else 360 net->cc_mod.rtcc.step_cnt = 1; 361 net->cc_mod.rtcc.last_step_state = 5; 362 if ((net->cc_mod.rtcc.step_cnt == net->cc_mod.rtcc.steady_step) || 363 ((net->cc_mod.rtcc.step_cnt > net->cc_mod.rtcc.steady_step) && 364 ((net->cc_mod.rtcc.step_cnt % net->cc_mod.rtcc.steady_step) == 0))) { 365 /* Try a step down */ 366 if (net->cwnd > (4 * net->mtu)) { 367 net->cwnd -= net->mtu; 368 net->cc_mod.rtcc.vol_reduce++; 369 return (1); 370 } else { 371 net->cc_mod.rtcc.step_cnt = 0; 372 } 373 } 374 } 375 if (inst_ind == SCTP_INST_GAINING) 376 return (1); 377 else if (inst_ind == SCTP_INST_NEUTRAL) 378 return (1); 379 else 380 return ((int)net->cc_mod.rtcc.ret_from_eq); 381 } 382 383 static int 384 cc_bw_decrease(struct sctp_tcb *stcb, struct sctp_nets *net, uint64_t nbw, uint64_t rtt_offset, 385 uint64_t vtag, uint8_t inst_ind) 386 { 387 uint64_t oth __sdt_used, probepoint __sdt_used; 388 389 /* Bandwidth decreased. */ 390 probepoint = (((uint64_t)net->cwnd) << 32); 391 if (net->rtt > net->cc_mod.rtcc.lbw_rtt + rtt_offset) { 392 /* rtt increased */ 393 /* Did we add more */ 394 if ((net->cwnd > net->cc_mod.rtcc.cwnd_at_bw_set) && 395 (inst_ind != SCTP_INST_LOOSING)) { 396 /* We caused it maybe.. back off? */ 397 /* PROBE POINT 1 */ 398 probepoint |= ((1 << 16) | 1); 399 SDT_PROBE5(sctp, cwnd, net, rttvar, 400 vtag, 401 ((net->cc_mod.rtcc.lbw << 32) | nbw), 402 ((net->cc_mod.rtcc.lbw_rtt << 32) | net->rtt), 403 net->flight_size, 404 probepoint); 405 if (net->cc_mod.rtcc.ret_from_eq) { 406 /* 407 * Switch over to CA if we are less 408 * aggressive 409 */ 410 net->ssthresh = net->cwnd - 1; 411 net->partial_bytes_acked = 0; 412 } 413 return (1); 414 } 415 /* Probe point 2 */ 416 probepoint |= ((2 << 16) | 0); 417 SDT_PROBE5(sctp, cwnd, net, rttvar, 418 vtag, 419 ((net->cc_mod.rtcc.lbw << 32) | nbw), 420 ((net->cc_mod.rtcc.lbw_rtt << 32) | net->rtt), 421 net->flight_size, 422 probepoint); 423 /* Someone else - fight for more? */ 424 if (net->cc_mod.rtcc.steady_step) { 425 oth = net->cc_mod.rtcc.vol_reduce; 426 oth <<= 16; 427 oth |= net->cc_mod.rtcc.step_cnt; 428 oth <<= 16; 429 oth |= net->cc_mod.rtcc.last_step_state; 430 SDT_PROBE5(sctp, cwnd, net, rttstep, 431 vtag, 432 ((net->cc_mod.rtcc.lbw << 32) | nbw), 433 ((net->cc_mod.rtcc.lbw_rtt << 32) | net->rtt), 434 oth, 435 probepoint); 436 /* 437 * Did we voluntarily give up some? if so take one 438 * back please 439 */ 440 if ((net->cc_mod.rtcc.vol_reduce) && 441 (inst_ind != SCTP_INST_GAINING)) { 442 net->cwnd += net->mtu; 443 sctp_enforce_cwnd_limit(&stcb->asoc, net); 444 net->cc_mod.rtcc.vol_reduce--; 445 } 446 net->cc_mod.rtcc.last_step_state = 2; 447 net->cc_mod.rtcc.step_cnt = 0; 448 } 449 goto out_decision; 450 } else if (net->rtt < net->cc_mod.rtcc.lbw_rtt - rtt_offset) { 451 /* bw & rtt decreased */ 452 /* Probe point 3 */ 453 probepoint |= ((3 << 16) | 0); 454 SDT_PROBE5(sctp, cwnd, net, rttvar, 455 vtag, 456 ((net->cc_mod.rtcc.lbw << 32) | nbw), 457 ((net->cc_mod.rtcc.lbw_rtt << 32) | net->rtt), 458 net->flight_size, 459 probepoint); 460 if (net->cc_mod.rtcc.steady_step) { 461 oth = net->cc_mod.rtcc.vol_reduce; 462 oth <<= 16; 463 oth |= net->cc_mod.rtcc.step_cnt; 464 oth <<= 16; 465 oth |= net->cc_mod.rtcc.last_step_state; 466 SDT_PROBE5(sctp, cwnd, net, rttstep, 467 vtag, 468 ((net->cc_mod.rtcc.lbw << 32) | nbw), 469 ((net->cc_mod.rtcc.lbw_rtt << 32) | net->rtt), 470 oth, 471 probepoint); 472 if ((net->cc_mod.rtcc.vol_reduce) && 473 (inst_ind != SCTP_INST_GAINING)) { 474 net->cwnd += net->mtu; 475 sctp_enforce_cwnd_limit(&stcb->asoc, net); 476 net->cc_mod.rtcc.vol_reduce--; 477 } 478 net->cc_mod.rtcc.last_step_state = 3; 479 net->cc_mod.rtcc.step_cnt = 0; 480 } 481 goto out_decision; 482 } 483 /* The bw decreased but rtt stayed the same */ 484 /* Probe point 4 */ 485 probepoint |= ((4 << 16) | 0); 486 SDT_PROBE5(sctp, cwnd, net, rttvar, 487 vtag, 488 ((net->cc_mod.rtcc.lbw << 32) | nbw), 489 ((net->cc_mod.rtcc.lbw_rtt << 32) | net->rtt), 490 net->flight_size, 491 probepoint); 492 if (net->cc_mod.rtcc.steady_step) { 493 oth = net->cc_mod.rtcc.vol_reduce; 494 oth <<= 16; 495 oth |= net->cc_mod.rtcc.step_cnt; 496 oth <<= 16; 497 oth |= net->cc_mod.rtcc.last_step_state; 498 SDT_PROBE5(sctp, cwnd, net, rttstep, 499 vtag, 500 ((net->cc_mod.rtcc.lbw << 32) | nbw), 501 ((net->cc_mod.rtcc.lbw_rtt << 32) | net->rtt), 502 oth, 503 probepoint); 504 if ((net->cc_mod.rtcc.vol_reduce) && 505 (inst_ind != SCTP_INST_GAINING)) { 506 net->cwnd += net->mtu; 507 sctp_enforce_cwnd_limit(&stcb->asoc, net); 508 net->cc_mod.rtcc.vol_reduce--; 509 } 510 net->cc_mod.rtcc.last_step_state = 4; 511 net->cc_mod.rtcc.step_cnt = 0; 512 } 513 out_decision: 514 net->cc_mod.rtcc.lbw = nbw; 515 net->cc_mod.rtcc.lbw_rtt = net->rtt; 516 net->cc_mod.rtcc.cwnd_at_bw_set = net->cwnd; 517 if (inst_ind == SCTP_INST_GAINING) { 518 return (1); 519 } else { 520 return (0); 521 } 522 } 523 524 static int 525 cc_bw_increase(struct sctp_tcb *stcb, struct sctp_nets *net, uint64_t nbw, uint64_t vtag) 526 { 527 uint64_t oth __sdt_used, probepoint __sdt_used; 528 529 /* 530 * BW increased, so update and return 0, since all actions in our 531 * table say to do the normal CC update. Note that we pay no 532 * attention to the inst_ind since our overall sum is increasing. 533 */ 534 /* PROBE POINT 0 */ 535 probepoint = (((uint64_t)net->cwnd) << 32); 536 SDT_PROBE5(sctp, cwnd, net, rttvar, 537 vtag, 538 ((net->cc_mod.rtcc.lbw << 32) | nbw), 539 ((net->cc_mod.rtcc.lbw_rtt << 32) | net->rtt), 540 net->flight_size, 541 probepoint); 542 if (net->cc_mod.rtcc.steady_step) { 543 oth = net->cc_mod.rtcc.vol_reduce; 544 oth <<= 16; 545 oth |= net->cc_mod.rtcc.step_cnt; 546 oth <<= 16; 547 oth |= net->cc_mod.rtcc.last_step_state; 548 SDT_PROBE5(sctp, cwnd, net, rttstep, 549 vtag, 550 ((net->cc_mod.rtcc.lbw << 32) | nbw), 551 ((net->cc_mod.rtcc.lbw_rtt << 32) | net->rtt), 552 oth, 553 probepoint); 554 net->cc_mod.rtcc.last_step_state = 0; 555 net->cc_mod.rtcc.step_cnt = 0; 556 net->cc_mod.rtcc.vol_reduce = 0; 557 } 558 net->cc_mod.rtcc.lbw = nbw; 559 net->cc_mod.rtcc.lbw_rtt = net->rtt; 560 net->cc_mod.rtcc.cwnd_at_bw_set = net->cwnd; 561 return (0); 562 } 563 564 /* RTCC Algorithm to limit growth of cwnd, return 565 * true if you want to NOT allow cwnd growth 566 */ 567 static int 568 cc_bw_limit(struct sctp_tcb *stcb, struct sctp_nets *net, uint64_t nbw) 569 { 570 uint64_t bw_offset, rtt_offset; 571 uint64_t probepoint __sdt_used, rtt, vtag; 572 uint64_t bytes_for_this_rtt, inst_bw; 573 uint64_t div, inst_off; 574 int bw_shift; 575 uint8_t inst_ind; 576 int ret; 577 578 /*- 579 * Here we need to see if we want 580 * to limit cwnd growth due to increase 581 * in overall rtt but no increase in bw. 582 * We use the following table to figure 583 * out what we should do. When we return 584 * 0, cc update goes on as planned. If we 585 * return 1, then no cc update happens and cwnd 586 * stays where it is at. 587 * ---------------------------------- 588 * BW | RTT | Action 589 * ********************************* 590 * INC | INC | return 0 591 * ---------------------------------- 592 * INC | SAME | return 0 593 * ---------------------------------- 594 * INC | DECR | return 0 595 * ---------------------------------- 596 * SAME | INC | return 1 597 * ---------------------------------- 598 * SAME | SAME | return 1 599 * ---------------------------------- 600 * SAME | DECR | return 0 601 * ---------------------------------- 602 * DECR | INC | return 0 or 1 based on if we caused. 603 * ---------------------------------- 604 * DECR | SAME | return 0 605 * ---------------------------------- 606 * DECR | DECR | return 0 607 * ---------------------------------- 608 * 609 * We are a bit fuzz on what an increase or 610 * decrease is. For BW it is the same if 611 * it did not change within 1/64th. For 612 * RTT it stayed the same if it did not 613 * change within 1/32nd 614 */ 615 bw_shift = SCTP_BASE_SYSCTL(sctp_rttvar_bw); 616 rtt = stcb->asoc.my_vtag; 617 vtag = (rtt << 32) | (((uint32_t)(stcb->sctp_ep->sctp_lport)) << 16) | (stcb->rport); 618 probepoint = (((uint64_t)net->cwnd) << 32); 619 rtt = net->rtt; 620 if (net->cc_mod.rtcc.rtt_set_this_sack) { 621 net->cc_mod.rtcc.rtt_set_this_sack = 0; 622 bytes_for_this_rtt = net->cc_mod.rtcc.bw_bytes - net->cc_mod.rtcc.bw_bytes_at_last_rttc; 623 net->cc_mod.rtcc.bw_bytes_at_last_rttc = net->cc_mod.rtcc.bw_bytes; 624 if (net->rtt) { 625 div = net->rtt / 1000; 626 if (div) { 627 inst_bw = bytes_for_this_rtt / div; 628 inst_off = inst_bw >> bw_shift; 629 if (inst_bw > nbw) 630 inst_ind = SCTP_INST_GAINING; 631 else if ((inst_bw + inst_off) < nbw) 632 inst_ind = SCTP_INST_LOOSING; 633 else 634 inst_ind = SCTP_INST_NEUTRAL; 635 probepoint |= ((0xb << 16) | inst_ind); 636 } else { 637 inst_ind = net->cc_mod.rtcc.last_inst_ind; 638 inst_bw = bytes_for_this_rtt / (uint64_t)(net->rtt); 639 /* Can't determine do not change */ 640 probepoint |= ((0xc << 16) | inst_ind); 641 } 642 } else { 643 inst_ind = net->cc_mod.rtcc.last_inst_ind; 644 inst_bw = bytes_for_this_rtt; 645 /* Can't determine do not change */ 646 probepoint |= ((0xd << 16) | inst_ind); 647 } 648 SDT_PROBE5(sctp, cwnd, net, rttvar, 649 vtag, 650 ((nbw << 32) | inst_bw), 651 ((net->cc_mod.rtcc.lbw_rtt << 32) | rtt), 652 net->flight_size, 653 probepoint); 654 } else { 655 /* No rtt measurement, use last one */ 656 inst_ind = net->cc_mod.rtcc.last_inst_ind; 657 } 658 bw_offset = net->cc_mod.rtcc.lbw >> bw_shift; 659 if (nbw > net->cc_mod.rtcc.lbw + bw_offset) { 660 ret = cc_bw_increase(stcb, net, nbw, vtag); 661 goto out; 662 } 663 rtt_offset = net->cc_mod.rtcc.lbw_rtt >> SCTP_BASE_SYSCTL(sctp_rttvar_rtt); 664 if (nbw < net->cc_mod.rtcc.lbw - bw_offset) { 665 ret = cc_bw_decrease(stcb, net, nbw, rtt_offset, vtag, inst_ind); 666 goto out; 667 } 668 /* 669 * If we reach here then we are in a situation where the bw stayed 670 * the same. 671 */ 672 ret = cc_bw_same(stcb, net, nbw, rtt_offset, vtag, inst_ind); 673 out: 674 net->cc_mod.rtcc.last_inst_ind = inst_ind; 675 return (ret); 676 } 677 678 static void 679 sctp_cwnd_update_after_sack_common(struct sctp_tcb *stcb, 680 struct sctp_association *asoc, 681 int accum_moved, int reneged_all SCTP_UNUSED, int will_exit, int use_rtcc) 682 { 683 struct sctp_nets *net; 684 int old_cwnd __sdt_used; 685 uint32_t t_ssthresh, incr; 686 uint64_t t_ucwnd_sbw; 687 uint64_t t_path_mptcp; 688 uint64_t mptcp_like_alpha; 689 uint32_t srtt; 690 uint64_t max_path; 691 692 /* MT FIXME: Don't compute this over and over again */ 693 t_ssthresh = 0; 694 t_ucwnd_sbw = 0; 695 t_path_mptcp = 0; 696 mptcp_like_alpha = 1; 697 if ((stcb->asoc.sctp_cmt_on_off == SCTP_CMT_RPV1) || 698 (stcb->asoc.sctp_cmt_on_off == SCTP_CMT_RPV2) || 699 (stcb->asoc.sctp_cmt_on_off == SCTP_CMT_MPTCP)) { 700 max_path = 0; 701 TAILQ_FOREACH(net, &stcb->asoc.nets, sctp_next) { 702 t_ssthresh += net->ssthresh; 703 /* lastsa>>3; we don't need to devide ... */ 704 srtt = net->lastsa; 705 if (srtt > 0) { 706 uint64_t tmp; 707 708 t_ucwnd_sbw += (uint64_t)net->cwnd / (uint64_t)srtt; 709 t_path_mptcp += (((uint64_t)net->cwnd) << SHIFT_MPTCP_MULTI_Z) / 710 (((uint64_t)net->mtu) * (uint64_t)srtt); 711 tmp = (((uint64_t)net->cwnd) << SHIFT_MPTCP_MULTI_N) / 712 ((uint64_t)net->mtu * (uint64_t)(srtt * srtt)); 713 if (tmp > max_path) { 714 max_path = tmp; 715 } 716 } 717 } 718 if (t_path_mptcp > 0) { 719 mptcp_like_alpha = max_path / (t_path_mptcp * t_path_mptcp); 720 } else { 721 mptcp_like_alpha = 1; 722 } 723 } 724 if (t_ssthresh == 0) { 725 t_ssthresh = 1; 726 } 727 if (t_ucwnd_sbw == 0) { 728 t_ucwnd_sbw = 1; 729 } 730 /******************************/ 731 /* update cwnd and Early FR */ 732 /******************************/ 733 TAILQ_FOREACH(net, &asoc->nets, sctp_next) { 734 #ifdef JANA_CMT_FAST_RECOVERY 735 /* 736 * CMT fast recovery code. Need to debug. 737 */ 738 if (net->fast_retran_loss_recovery && net->new_pseudo_cumack) { 739 if (SCTP_TSN_GE(asoc->last_acked_seq, net->fast_recovery_tsn) || 740 SCTP_TSN_GE(net->pseudo_cumack, net->fast_recovery_tsn)) { 741 net->will_exit_fast_recovery = 1; 742 } 743 } 744 #endif 745 /* if nothing was acked on this destination skip it */ 746 if (net->net_ack == 0) { 747 if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_CWND_LOGGING_ENABLE) { 748 sctp_log_cwnd(stcb, net, 0, SCTP_CWND_LOG_FROM_SACK); 749 } 750 continue; 751 } 752 #ifdef JANA_CMT_FAST_RECOVERY 753 /* 754 * CMT fast recovery code 755 */ 756 /* 757 * if (sctp_cmt_on_off > 0 && net->fast_retran_loss_recovery 758 * && net->will_exit_fast_recovery == 0) { @@@ Do something 759 * } else if (sctp_cmt_on_off == 0 && 760 * asoc->fast_retran_loss_recovery && will_exit == 0) { 761 */ 762 #endif 763 764 if (asoc->fast_retran_loss_recovery && 765 (will_exit == 0) && 766 (asoc->sctp_cmt_on_off == 0)) { 767 /* 768 * If we are in loss recovery we skip any cwnd 769 * update 770 */ 771 return; 772 } 773 /* 774 * Did any measurements go on for this network? 775 */ 776 if (use_rtcc && (net->cc_mod.rtcc.tls_needs_set > 0)) { 777 uint64_t nbw; 778 779 /* 780 * At this point our bw_bytes has been updated by 781 * incoming sack information. 782 * 783 * But our bw may not yet be set. 784 * 785 */ 786 if ((net->cc_mod.rtcc.new_tot_time / 1000) > 0) { 787 nbw = net->cc_mod.rtcc.bw_bytes / (net->cc_mod.rtcc.new_tot_time / 1000); 788 } else { 789 nbw = net->cc_mod.rtcc.bw_bytes; 790 } 791 if (net->cc_mod.rtcc.lbw) { 792 if (cc_bw_limit(stcb, net, nbw)) { 793 /* Hold here, no update */ 794 continue; 795 } 796 } else { 797 uint64_t vtag __sdt_used, probepoint __sdt_used; 798 799 probepoint = (((uint64_t)net->cwnd) << 32); 800 probepoint |= ((0xa << 16) | 0); 801 vtag = (net->rtt << 32) | 802 (((uint32_t)(stcb->sctp_ep->sctp_lport)) << 16) | 803 (stcb->rport); 804 805 SDT_PROBE5(sctp, cwnd, net, rttvar, 806 vtag, 807 nbw, 808 ((net->cc_mod.rtcc.lbw_rtt << 32) | net->rtt), 809 net->flight_size, 810 probepoint); 811 net->cc_mod.rtcc.lbw = nbw; 812 net->cc_mod.rtcc.lbw_rtt = net->rtt; 813 if (net->cc_mod.rtcc.rtt_set_this_sack) { 814 net->cc_mod.rtcc.rtt_set_this_sack = 0; 815 net->cc_mod.rtcc.bw_bytes_at_last_rttc = net->cc_mod.rtcc.bw_bytes; 816 } 817 } 818 } 819 /* 820 * CMT: CUC algorithm. Update cwnd if pseudo-cumack has 821 * moved. 822 */ 823 if (accum_moved || 824 ((asoc->sctp_cmt_on_off > 0) && net->new_pseudo_cumack)) { 825 /* If the cumulative ack moved we can proceed */ 826 if (net->cwnd <= net->ssthresh) { 827 /* We are in slow start */ 828 if (net->flight_size + net->net_ack >= net->cwnd) { 829 uint32_t limit; 830 831 old_cwnd = net->cwnd; 832 switch (asoc->sctp_cmt_on_off) { 833 case SCTP_CMT_RPV1: 834 limit = (uint32_t)(((uint64_t)net->mtu * 835 (uint64_t)SCTP_BASE_SYSCTL(sctp_L2_abc_variable) * 836 (uint64_t)net->ssthresh) / 837 (uint64_t)t_ssthresh); 838 incr = (uint32_t)(((uint64_t)net->net_ack * 839 (uint64_t)net->ssthresh) / 840 (uint64_t)t_ssthresh); 841 if (incr > limit) { 842 incr = limit; 843 } 844 if (incr == 0) { 845 incr = 1; 846 } 847 break; 848 case SCTP_CMT_RPV2: 849 /* 850 * lastsa>>3; we don't need 851 * to divide ... 852 */ 853 srtt = net->lastsa; 854 if (srtt == 0) { 855 srtt = 1; 856 } 857 limit = (uint32_t)(((uint64_t)net->mtu * 858 (uint64_t)SCTP_BASE_SYSCTL(sctp_L2_abc_variable) * 859 (uint64_t)net->cwnd) / 860 ((uint64_t)srtt * t_ucwnd_sbw)); 861 /* INCREASE FACTOR */ 862 incr = (uint32_t)(((uint64_t)net->net_ack * 863 (uint64_t)net->cwnd) / 864 ((uint64_t)srtt * t_ucwnd_sbw)); 865 /* INCREASE FACTOR */ 866 if (incr > limit) { 867 incr = limit; 868 } 869 if (incr == 0) { 870 incr = 1; 871 } 872 break; 873 case SCTP_CMT_MPTCP: 874 limit = (uint32_t)(((uint64_t)net->mtu * 875 mptcp_like_alpha * 876 (uint64_t)SCTP_BASE_SYSCTL(sctp_L2_abc_variable)) >> 877 SHIFT_MPTCP_MULTI); 878 incr = (uint32_t)(((uint64_t)net->net_ack * 879 mptcp_like_alpha) >> 880 SHIFT_MPTCP_MULTI); 881 if (incr > limit) { 882 incr = limit; 883 } 884 if (incr > net->net_ack) { 885 incr = net->net_ack; 886 } 887 if (incr > net->mtu) { 888 incr = net->mtu; 889 } 890 break; 891 default: 892 incr = net->net_ack; 893 if (incr > net->mtu * SCTP_BASE_SYSCTL(sctp_L2_abc_variable)) { 894 incr = net->mtu * SCTP_BASE_SYSCTL(sctp_L2_abc_variable); 895 } 896 break; 897 } 898 net->cwnd += incr; 899 sctp_enforce_cwnd_limit(asoc, net); 900 if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_CWND_MONITOR_ENABLE) { 901 sctp_log_cwnd(stcb, net, incr, 902 SCTP_CWND_LOG_FROM_SS); 903 } 904 SDT_PROBE5(sctp, cwnd, net, ack, 905 stcb->asoc.my_vtag, 906 ((stcb->sctp_ep->sctp_lport << 16) | (stcb->rport)), 907 net, 908 old_cwnd, net->cwnd); 909 } else { 910 if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_CWND_LOGGING_ENABLE) { 911 sctp_log_cwnd(stcb, net, net->net_ack, 912 SCTP_CWND_LOG_NOADV_SS); 913 } 914 } 915 } else { 916 /* We are in congestion avoidance */ 917 /* 918 * Add to pba 919 */ 920 net->partial_bytes_acked += net->net_ack; 921 922 if ((net->flight_size + net->net_ack >= net->cwnd) && 923 (net->partial_bytes_acked >= net->cwnd)) { 924 net->partial_bytes_acked -= net->cwnd; 925 old_cwnd = net->cwnd; 926 switch (asoc->sctp_cmt_on_off) { 927 case SCTP_CMT_RPV1: 928 incr = (uint32_t)(((uint64_t)net->mtu * 929 (uint64_t)net->ssthresh) / 930 (uint64_t)t_ssthresh); 931 if (incr == 0) { 932 incr = 1; 933 } 934 break; 935 case SCTP_CMT_RPV2: 936 /* 937 * lastsa>>3; we don't need 938 * to divide ... 939 */ 940 srtt = net->lastsa; 941 if (srtt == 0) { 942 srtt = 1; 943 } 944 incr = (uint32_t)((uint64_t)net->mtu * 945 (uint64_t)net->cwnd / 946 ((uint64_t)srtt * 947 t_ucwnd_sbw)); 948 /* INCREASE FACTOR */ 949 if (incr == 0) { 950 incr = 1; 951 } 952 break; 953 case SCTP_CMT_MPTCP: 954 incr = (uint32_t)((mptcp_like_alpha * 955 (uint64_t)net->cwnd) >> 956 SHIFT_MPTCP_MULTI); 957 if (incr > net->mtu) { 958 incr = net->mtu; 959 } 960 break; 961 default: 962 incr = net->mtu; 963 break; 964 } 965 net->cwnd += incr; 966 sctp_enforce_cwnd_limit(asoc, net); 967 SDT_PROBE5(sctp, cwnd, net, ack, 968 stcb->asoc.my_vtag, 969 ((stcb->sctp_ep->sctp_lport << 16) | (stcb->rport)), 970 net, 971 old_cwnd, net->cwnd); 972 if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_CWND_MONITOR_ENABLE) { 973 sctp_log_cwnd(stcb, net, net->mtu, 974 SCTP_CWND_LOG_FROM_CA); 975 } 976 } else { 977 if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_CWND_LOGGING_ENABLE) { 978 sctp_log_cwnd(stcb, net, net->net_ack, 979 SCTP_CWND_LOG_NOADV_CA); 980 } 981 } 982 } 983 } else { 984 if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_CWND_LOGGING_ENABLE) { 985 sctp_log_cwnd(stcb, net, net->mtu, 986 SCTP_CWND_LOG_NO_CUMACK); 987 } 988 } 989 } 990 } 991 992 static void 993 sctp_cwnd_update_exit_pf_common(struct sctp_tcb *stcb, struct sctp_nets *net) 994 { 995 int old_cwnd __sdt_used; 996 997 old_cwnd = net->cwnd; 998 net->cwnd = net->mtu; 999 SDT_PROBE5(sctp, cwnd, net, ack, 1000 stcb->asoc.my_vtag, ((stcb->sctp_ep->sctp_lport << 16) | (stcb->rport)), net, 1001 old_cwnd, net->cwnd); 1002 SCTPDBG(SCTP_DEBUG_INDATA1, "Destination %p moved from PF to reachable with cwnd %d.\n", 1003 (void *)net, net->cwnd); 1004 } 1005 1006 static void 1007 sctp_cwnd_update_after_timeout(struct sctp_tcb *stcb, struct sctp_nets *net) 1008 { 1009 int old_cwnd = net->cwnd; 1010 uint32_t t_ssthresh, t_cwnd; 1011 uint64_t t_ucwnd_sbw; 1012 1013 /* MT FIXME: Don't compute this over and over again */ 1014 t_ssthresh = 0; 1015 t_cwnd = 0; 1016 if ((stcb->asoc.sctp_cmt_on_off == SCTP_CMT_RPV1) || 1017 (stcb->asoc.sctp_cmt_on_off == SCTP_CMT_RPV2)) { 1018 struct sctp_nets *lnet; 1019 uint32_t srtt; 1020 1021 t_ucwnd_sbw = 0; 1022 TAILQ_FOREACH(lnet, &stcb->asoc.nets, sctp_next) { 1023 t_ssthresh += lnet->ssthresh; 1024 t_cwnd += lnet->cwnd; 1025 srtt = lnet->lastsa; 1026 /* lastsa>>3; we don't need to divide ... */ 1027 if (srtt > 0) { 1028 t_ucwnd_sbw += (uint64_t)lnet->cwnd / (uint64_t)srtt; 1029 } 1030 } 1031 if (t_ssthresh < 1) { 1032 t_ssthresh = 1; 1033 } 1034 if (t_ucwnd_sbw < 1) { 1035 t_ucwnd_sbw = 1; 1036 } 1037 if (stcb->asoc.sctp_cmt_on_off == SCTP_CMT_RPV1) { 1038 net->ssthresh = (uint32_t)(((uint64_t)4 * 1039 (uint64_t)net->mtu * 1040 (uint64_t)net->ssthresh) / 1041 (uint64_t)t_ssthresh); 1042 } else { 1043 uint64_t cc_delta; 1044 1045 srtt = net->lastsa; 1046 /* lastsa>>3; we don't need to divide ... */ 1047 if (srtt == 0) { 1048 srtt = 1; 1049 } 1050 cc_delta = t_ucwnd_sbw * (uint64_t)srtt / 2; 1051 if (cc_delta < t_cwnd) { 1052 net->ssthresh = (uint32_t)((uint64_t)t_cwnd - cc_delta); 1053 } else { 1054 net->ssthresh = net->mtu; 1055 } 1056 } 1057 if ((net->cwnd > t_cwnd / 2) && 1058 (net->ssthresh < net->cwnd - t_cwnd / 2)) { 1059 net->ssthresh = net->cwnd - t_cwnd / 2; 1060 } 1061 if (net->ssthresh < net->mtu) { 1062 net->ssthresh = net->mtu; 1063 } 1064 } else { 1065 net->ssthresh = max(net->cwnd / 2, 4 * net->mtu); 1066 } 1067 net->cwnd = net->mtu; 1068 net->partial_bytes_acked = 0; 1069 SDT_PROBE5(sctp, cwnd, net, to, 1070 stcb->asoc.my_vtag, 1071 ((stcb->sctp_ep->sctp_lport << 16) | (stcb->rport)), 1072 net, 1073 old_cwnd, net->cwnd); 1074 if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_CWND_MONITOR_ENABLE) { 1075 sctp_log_cwnd(stcb, net, net->cwnd - old_cwnd, SCTP_CWND_LOG_FROM_RTX); 1076 } 1077 } 1078 1079 static void 1080 sctp_cwnd_update_after_ecn_echo_common(struct sctp_tcb *stcb, struct sctp_nets *net, 1081 int in_window, int num_pkt_lost, int use_rtcc) 1082 { 1083 int old_cwnd = net->cwnd; 1084 1085 if ((use_rtcc) && (net->lan_type == SCTP_LAN_LOCAL) && (net->cc_mod.rtcc.use_dccc_ecn)) { 1086 /* Data center Congestion Control */ 1087 if (in_window == 0) { 1088 /* 1089 * Go to CA with the cwnd at the point we sent the 1090 * TSN that was marked with a CE. 1091 */ 1092 if (net->ecn_prev_cwnd < net->cwnd) { 1093 /* Restore to prev cwnd */ 1094 net->cwnd = net->ecn_prev_cwnd - (net->mtu * num_pkt_lost); 1095 } else { 1096 /* Just cut in 1/2 */ 1097 net->cwnd /= 2; 1098 } 1099 /* Drop to CA */ 1100 net->ssthresh = net->cwnd - (num_pkt_lost * net->mtu); 1101 if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_CWND_MONITOR_ENABLE) { 1102 sctp_log_cwnd(stcb, net, (net->cwnd - old_cwnd), SCTP_CWND_LOG_FROM_SAT); 1103 } 1104 } else { 1105 /* 1106 * Further tuning down required over the drastic 1107 * original cut 1108 */ 1109 net->ssthresh -= (net->mtu * num_pkt_lost); 1110 net->cwnd -= (net->mtu * num_pkt_lost); 1111 if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_CWND_MONITOR_ENABLE) { 1112 sctp_log_cwnd(stcb, net, (net->cwnd - old_cwnd), SCTP_CWND_LOG_FROM_SAT); 1113 } 1114 } 1115 SCTP_STAT_INCR(sctps_ecnereducedcwnd); 1116 } else { 1117 if (in_window == 0) { 1118 SCTP_STAT_INCR(sctps_ecnereducedcwnd); 1119 net->ssthresh = net->cwnd / 2; 1120 if (net->ssthresh < net->mtu) { 1121 net->ssthresh = net->mtu; 1122 /* 1123 * here back off the timer as well, to slow 1124 * us down 1125 */ 1126 net->RTO <<= 1; 1127 } 1128 net->cwnd = net->ssthresh; 1129 SDT_PROBE5(sctp, cwnd, net, ecn, 1130 stcb->asoc.my_vtag, 1131 ((stcb->sctp_ep->sctp_lport << 16) | (stcb->rport)), 1132 net, 1133 old_cwnd, net->cwnd); 1134 if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_CWND_MONITOR_ENABLE) { 1135 sctp_log_cwnd(stcb, net, (net->cwnd - old_cwnd), SCTP_CWND_LOG_FROM_SAT); 1136 } 1137 } 1138 } 1139 1140 } 1141 1142 static void 1143 sctp_cwnd_update_after_packet_dropped(struct sctp_tcb *stcb, 1144 struct sctp_nets *net, struct sctp_pktdrop_chunk *cp, 1145 uint32_t *bottle_bw, uint32_t *on_queue) 1146 { 1147 uint32_t bw_avail; 1148 unsigned int incr; 1149 int old_cwnd = net->cwnd; 1150 1151 /* get bottle neck bw */ 1152 *bottle_bw = ntohl(cp->bottle_bw); 1153 /* and whats on queue */ 1154 *on_queue = ntohl(cp->current_onq); 1155 /* 1156 * adjust the on-queue if our flight is more it could be that the 1157 * router has not yet gotten data "in-flight" to it 1158 */ 1159 if (*on_queue < net->flight_size) { 1160 *on_queue = net->flight_size; 1161 } 1162 /* rtt is measured in micro seconds, bottle_bw in bytes per second */ 1163 bw_avail = (uint32_t)(((uint64_t)(*bottle_bw) * net->rtt) / (uint64_t)1000000); 1164 if (bw_avail > *bottle_bw) { 1165 /* 1166 * Cap the growth to no more than the bottle neck. This can 1167 * happen as RTT slides up due to queues. It also means if 1168 * you have more than a 1 second RTT with a empty queue you 1169 * will be limited to the bottle_bw per second no matter if 1170 * other points have 1/2 the RTT and you could get more 1171 * out... 1172 */ 1173 bw_avail = *bottle_bw; 1174 } 1175 if (*on_queue > bw_avail) { 1176 /* 1177 * No room for anything else don't allow anything else to be 1178 * "added to the fire". 1179 */ 1180 int seg_inflight, seg_onqueue, my_portion; 1181 1182 net->partial_bytes_acked = 0; 1183 /* how much are we over queue size? */ 1184 incr = *on_queue - bw_avail; 1185 if (stcb->asoc.seen_a_sack_this_pkt) { 1186 /* 1187 * undo any cwnd adjustment that the sack might have 1188 * made 1189 */ 1190 net->cwnd = net->prev_cwnd; 1191 } 1192 /* Now how much of that is mine? */ 1193 seg_inflight = net->flight_size / net->mtu; 1194 seg_onqueue = *on_queue / net->mtu; 1195 my_portion = (incr * seg_inflight) / seg_onqueue; 1196 1197 /* Have I made an adjustment already */ 1198 if (net->cwnd > net->flight_size) { 1199 /* 1200 * for this flight I made an adjustment we need to 1201 * decrease the portion by a share our previous 1202 * adjustment. 1203 */ 1204 int diff_adj; 1205 1206 diff_adj = net->cwnd - net->flight_size; 1207 if (diff_adj > my_portion) 1208 my_portion = 0; 1209 else 1210 my_portion -= diff_adj; 1211 } 1212 /* 1213 * back down to the previous cwnd (assume we have had a sack 1214 * before this packet). minus what ever portion of the 1215 * overage is my fault. 1216 */ 1217 net->cwnd -= my_portion; 1218 1219 /* we will NOT back down more than 1 MTU */ 1220 if (net->cwnd <= net->mtu) { 1221 net->cwnd = net->mtu; 1222 } 1223 /* force into CA */ 1224 net->ssthresh = net->cwnd - 1; 1225 } else { 1226 /* 1227 * Take 1/4 of the space left or max burst up .. whichever 1228 * is less. 1229 */ 1230 incr = (bw_avail - *on_queue) >> 2; 1231 if ((stcb->asoc.max_burst > 0) && 1232 (stcb->asoc.max_burst * net->mtu < incr)) { 1233 incr = stcb->asoc.max_burst * net->mtu; 1234 } 1235 net->cwnd += incr; 1236 } 1237 if (net->cwnd > bw_avail) { 1238 /* We can't exceed the pipe size */ 1239 net->cwnd = bw_avail; 1240 } 1241 if (net->cwnd < net->mtu) { 1242 /* We always have 1 MTU */ 1243 net->cwnd = net->mtu; 1244 } 1245 sctp_enforce_cwnd_limit(&stcb->asoc, net); 1246 if (net->cwnd - old_cwnd != 0) { 1247 /* log only changes */ 1248 SDT_PROBE5(sctp, cwnd, net, pd, 1249 stcb->asoc.my_vtag, 1250 ((stcb->sctp_ep->sctp_lport << 16) | (stcb->rport)), 1251 net, 1252 old_cwnd, net->cwnd); 1253 if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_CWND_MONITOR_ENABLE) { 1254 sctp_log_cwnd(stcb, net, (net->cwnd - old_cwnd), 1255 SCTP_CWND_LOG_FROM_SAT); 1256 } 1257 } 1258 } 1259 1260 static void 1261 sctp_cwnd_update_after_output(struct sctp_tcb *stcb, 1262 struct sctp_nets *net, int burst_limit) 1263 { 1264 int old_cwnd = net->cwnd; 1265 1266 if (net->ssthresh < net->cwnd) 1267 net->ssthresh = net->cwnd; 1268 if (burst_limit) { 1269 net->cwnd = (net->flight_size + (burst_limit * net->mtu)); 1270 sctp_enforce_cwnd_limit(&stcb->asoc, net); 1271 SDT_PROBE5(sctp, cwnd, net, bl, 1272 stcb->asoc.my_vtag, 1273 ((stcb->sctp_ep->sctp_lport << 16) | (stcb->rport)), 1274 net, 1275 old_cwnd, net->cwnd); 1276 if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_CWND_MONITOR_ENABLE) { 1277 sctp_log_cwnd(stcb, net, (net->cwnd - old_cwnd), SCTP_CWND_LOG_FROM_BRST); 1278 } 1279 } 1280 } 1281 1282 static void 1283 sctp_cwnd_update_after_sack(struct sctp_tcb *stcb, 1284 struct sctp_association *asoc, 1285 int accum_moved, int reneged_all, int will_exit) 1286 { 1287 /* Passing a zero argument in last disables the rtcc algorithm */ 1288 sctp_cwnd_update_after_sack_common(stcb, asoc, accum_moved, reneged_all, will_exit, 0); 1289 } 1290 1291 static void 1292 sctp_cwnd_update_after_ecn_echo(struct sctp_tcb *stcb, struct sctp_nets *net, 1293 int in_window, int num_pkt_lost) 1294 { 1295 /* Passing a zero argument in last disables the rtcc algorithm */ 1296 sctp_cwnd_update_after_ecn_echo_common(stcb, net, in_window, num_pkt_lost, 0); 1297 } 1298 1299 /* Here starts the RTCCVAR type CC invented by RRS which 1300 * is a slight mod to RFC2581. We reuse a common routine or 1301 * two since these algorithms are so close and need to 1302 * remain the same. 1303 */ 1304 static void 1305 sctp_cwnd_update_rtcc_after_ecn_echo(struct sctp_tcb *stcb, struct sctp_nets *net, 1306 int in_window, int num_pkt_lost) 1307 { 1308 sctp_cwnd_update_after_ecn_echo_common(stcb, net, in_window, num_pkt_lost, 1); 1309 } 1310 1311 static void 1312 sctp_cwnd_update_rtcc_tsn_acknowledged(struct sctp_nets *net, 1313 struct sctp_tmit_chunk *tp1) 1314 { 1315 net->cc_mod.rtcc.bw_bytes += tp1->send_size; 1316 } 1317 1318 static void 1319 sctp_cwnd_prepare_rtcc_net_for_sack(struct sctp_tcb *stcb SCTP_UNUSED, 1320 struct sctp_nets *net) 1321 { 1322 if (net->cc_mod.rtcc.tls_needs_set > 0) { 1323 /* We had a bw measurement going on */ 1324 struct timeval ltls; 1325 1326 SCTP_GETPTIME_TIMEVAL(<ls); 1327 timevalsub(<ls, &net->cc_mod.rtcc.tls); 1328 net->cc_mod.rtcc.new_tot_time = (ltls.tv_sec * 1000000) + ltls.tv_usec; 1329 } 1330 } 1331 1332 static void 1333 sctp_cwnd_new_rtcc_transmission_begins(struct sctp_tcb *stcb, 1334 struct sctp_nets *net) 1335 { 1336 uint64_t vtag __sdt_used, probepoint __sdt_used; 1337 1338 if (net->cc_mod.rtcc.lbw) { 1339 /* Clear the old bw.. we went to 0 in-flight */ 1340 vtag = (net->rtt << 32) | (((uint32_t)(stcb->sctp_ep->sctp_lport)) << 16) | 1341 (stcb->rport); 1342 probepoint = (((uint64_t)net->cwnd) << 32); 1343 /* Probe point 8 */ 1344 probepoint |= ((8 << 16) | 0); 1345 SDT_PROBE5(sctp, cwnd, net, rttvar, 1346 vtag, 1347 ((net->cc_mod.rtcc.lbw << 32) | 0), 1348 ((net->cc_mod.rtcc.lbw_rtt << 32) | net->rtt), 1349 net->flight_size, 1350 probepoint); 1351 net->cc_mod.rtcc.lbw_rtt = 0; 1352 net->cc_mod.rtcc.cwnd_at_bw_set = 0; 1353 net->cc_mod.rtcc.lbw = 0; 1354 net->cc_mod.rtcc.bw_bytes_at_last_rttc = 0; 1355 net->cc_mod.rtcc.vol_reduce = 0; 1356 net->cc_mod.rtcc.bw_tot_time = 0; 1357 net->cc_mod.rtcc.bw_bytes = 0; 1358 net->cc_mod.rtcc.tls_needs_set = 0; 1359 if (net->cc_mod.rtcc.steady_step) { 1360 net->cc_mod.rtcc.vol_reduce = 0; 1361 net->cc_mod.rtcc.step_cnt = 0; 1362 net->cc_mod.rtcc.last_step_state = 0; 1363 } 1364 if (net->cc_mod.rtcc.ret_from_eq) { 1365 /* less aggressive one - reset cwnd too */ 1366 uint32_t cwnd_in_mtu, cwnd; 1367 1368 cwnd_in_mtu = SCTP_BASE_SYSCTL(sctp_initial_cwnd); 1369 if (cwnd_in_mtu == 0) { 1370 /* 1371 * Using 0 means that the value of RFC 4960 1372 * is used. 1373 */ 1374 cwnd = min((net->mtu * 4), max((2 * net->mtu), SCTP_INITIAL_CWND)); 1375 } else { 1376 /* 1377 * We take the minimum of the burst limit 1378 * and the initial congestion window. 1379 */ 1380 if ((stcb->asoc.max_burst > 0) && (cwnd_in_mtu > stcb->asoc.max_burst)) 1381 cwnd_in_mtu = stcb->asoc.max_burst; 1382 cwnd = (net->mtu - sizeof(struct sctphdr)) * cwnd_in_mtu; 1383 } 1384 if (net->cwnd > cwnd) { 1385 /* 1386 * Only set if we are not a timeout (i.e. 1387 * down to 1 mtu) 1388 */ 1389 net->cwnd = cwnd; 1390 } 1391 } 1392 } 1393 } 1394 1395 static void 1396 sctp_set_rtcc_initial_cc_param(struct sctp_tcb *stcb, 1397 struct sctp_nets *net) 1398 { 1399 uint64_t vtag __sdt_used, probepoint __sdt_used; 1400 1401 sctp_set_initial_cc_param(stcb, net); 1402 stcb->asoc.use_precise_time = 1; 1403 probepoint = (((uint64_t)net->cwnd) << 32); 1404 probepoint |= ((9 << 16) | 0); 1405 vtag = (net->rtt << 32) | 1406 (((uint32_t)(stcb->sctp_ep->sctp_lport)) << 16) | 1407 (stcb->rport); 1408 SDT_PROBE5(sctp, cwnd, net, rttvar, 1409 vtag, 1410 0, 1411 0, 1412 0, 1413 probepoint); 1414 net->cc_mod.rtcc.lbw_rtt = 0; 1415 net->cc_mod.rtcc.cwnd_at_bw_set = 0; 1416 net->cc_mod.rtcc.vol_reduce = 0; 1417 net->cc_mod.rtcc.lbw = 0; 1418 net->cc_mod.rtcc.vol_reduce = 0; 1419 net->cc_mod.rtcc.bw_bytes_at_last_rttc = 0; 1420 net->cc_mod.rtcc.bw_tot_time = 0; 1421 net->cc_mod.rtcc.bw_bytes = 0; 1422 net->cc_mod.rtcc.tls_needs_set = 0; 1423 net->cc_mod.rtcc.ret_from_eq = SCTP_BASE_SYSCTL(sctp_rttvar_eqret); 1424 net->cc_mod.rtcc.steady_step = SCTP_BASE_SYSCTL(sctp_steady_step); 1425 net->cc_mod.rtcc.use_dccc_ecn = SCTP_BASE_SYSCTL(sctp_use_dccc_ecn); 1426 net->cc_mod.rtcc.step_cnt = 0; 1427 net->cc_mod.rtcc.last_step_state = 0; 1428 } 1429 1430 static int 1431 sctp_cwnd_rtcc_socket_option(struct sctp_tcb *stcb, int setorget, 1432 struct sctp_cc_option *cc_opt) 1433 { 1434 struct sctp_nets *net; 1435 1436 if (setorget == 1) { 1437 /* a set */ 1438 if (cc_opt->option == SCTP_CC_OPT_RTCC_SETMODE) { 1439 if ((cc_opt->aid_value.assoc_value != 0) && 1440 (cc_opt->aid_value.assoc_value != 1)) { 1441 return (EINVAL); 1442 } 1443 TAILQ_FOREACH(net, &stcb->asoc.nets, sctp_next) { 1444 net->cc_mod.rtcc.ret_from_eq = cc_opt->aid_value.assoc_value; 1445 } 1446 } else if (cc_opt->option == SCTP_CC_OPT_USE_DCCC_ECN) { 1447 if ((cc_opt->aid_value.assoc_value != 0) && 1448 (cc_opt->aid_value.assoc_value != 1)) { 1449 return (EINVAL); 1450 } 1451 TAILQ_FOREACH(net, &stcb->asoc.nets, sctp_next) { 1452 net->cc_mod.rtcc.use_dccc_ecn = cc_opt->aid_value.assoc_value; 1453 } 1454 } else if (cc_opt->option == SCTP_CC_OPT_STEADY_STEP) { 1455 TAILQ_FOREACH(net, &stcb->asoc.nets, sctp_next) { 1456 net->cc_mod.rtcc.steady_step = cc_opt->aid_value.assoc_value; 1457 } 1458 } else { 1459 return (EINVAL); 1460 } 1461 } else { 1462 /* a get */ 1463 if (cc_opt->option == SCTP_CC_OPT_RTCC_SETMODE) { 1464 net = TAILQ_FIRST(&stcb->asoc.nets); 1465 if (net == NULL) { 1466 return (EFAULT); 1467 } 1468 cc_opt->aid_value.assoc_value = net->cc_mod.rtcc.ret_from_eq; 1469 } else if (cc_opt->option == SCTP_CC_OPT_USE_DCCC_ECN) { 1470 net = TAILQ_FIRST(&stcb->asoc.nets); 1471 if (net == NULL) { 1472 return (EFAULT); 1473 } 1474 cc_opt->aid_value.assoc_value = net->cc_mod.rtcc.use_dccc_ecn; 1475 } else if (cc_opt->option == SCTP_CC_OPT_STEADY_STEP) { 1476 net = TAILQ_FIRST(&stcb->asoc.nets); 1477 if (net == NULL) { 1478 return (EFAULT); 1479 } 1480 cc_opt->aid_value.assoc_value = net->cc_mod.rtcc.steady_step; 1481 } else { 1482 return (EINVAL); 1483 } 1484 } 1485 return (0); 1486 } 1487 1488 static void 1489 sctp_cwnd_update_rtcc_packet_transmitted(struct sctp_tcb *stcb SCTP_UNUSED, 1490 struct sctp_nets *net) 1491 { 1492 if (net->cc_mod.rtcc.tls_needs_set == 0) { 1493 SCTP_GETPTIME_TIMEVAL(&net->cc_mod.rtcc.tls); 1494 net->cc_mod.rtcc.tls_needs_set = 2; 1495 } 1496 } 1497 1498 static void 1499 sctp_cwnd_update_rtcc_after_sack(struct sctp_tcb *stcb, 1500 struct sctp_association *asoc, 1501 int accum_moved, int reneged_all, int will_exit) 1502 { 1503 /* Passing a one argument at the last enables the rtcc algorithm */ 1504 sctp_cwnd_update_after_sack_common(stcb, asoc, accum_moved, reneged_all, will_exit, 1); 1505 } 1506 1507 static void 1508 sctp_rtt_rtcc_calculated(struct sctp_tcb *stcb SCTP_UNUSED, 1509 struct sctp_nets *net, 1510 struct timeval *now SCTP_UNUSED) 1511 { 1512 net->cc_mod.rtcc.rtt_set_this_sack = 1; 1513 } 1514 1515 /* Here starts Sally Floyds HS-TCP */ 1516 1517 struct sctp_hs_raise_drop { 1518 int32_t cwnd; 1519 int8_t increase; 1520 int8_t drop_percent; 1521 }; 1522 1523 #define SCTP_HS_TABLE_SIZE 73 1524 1525 static const struct sctp_hs_raise_drop sctp_cwnd_adjust[SCTP_HS_TABLE_SIZE] = { 1526 {38, 1, 50}, /* 0 */ 1527 {118, 2, 44}, /* 1 */ 1528 {221, 3, 41}, /* 2 */ 1529 {347, 4, 38}, /* 3 */ 1530 {495, 5, 37}, /* 4 */ 1531 {663, 6, 35}, /* 5 */ 1532 {851, 7, 34}, /* 6 */ 1533 {1058, 8, 33}, /* 7 */ 1534 {1284, 9, 32}, /* 8 */ 1535 {1529, 10, 31}, /* 9 */ 1536 {1793, 11, 30}, /* 10 */ 1537 {2076, 12, 29}, /* 11 */ 1538 {2378, 13, 28}, /* 12 */ 1539 {2699, 14, 28}, /* 13 */ 1540 {3039, 15, 27}, /* 14 */ 1541 {3399, 16, 27}, /* 15 */ 1542 {3778, 17, 26}, /* 16 */ 1543 {4177, 18, 26}, /* 17 */ 1544 {4596, 19, 25}, /* 18 */ 1545 {5036, 20, 25}, /* 19 */ 1546 {5497, 21, 24}, /* 20 */ 1547 {5979, 22, 24}, /* 21 */ 1548 {6483, 23, 23}, /* 22 */ 1549 {7009, 24, 23}, /* 23 */ 1550 {7558, 25, 22}, /* 24 */ 1551 {8130, 26, 22}, /* 25 */ 1552 {8726, 27, 22}, /* 26 */ 1553 {9346, 28, 21}, /* 27 */ 1554 {9991, 29, 21}, /* 28 */ 1555 {10661, 30, 21}, /* 29 */ 1556 {11358, 31, 20}, /* 30 */ 1557 {12082, 32, 20}, /* 31 */ 1558 {12834, 33, 20}, /* 32 */ 1559 {13614, 34, 19}, /* 33 */ 1560 {14424, 35, 19}, /* 34 */ 1561 {15265, 36, 19}, /* 35 */ 1562 {16137, 37, 19}, /* 36 */ 1563 {17042, 38, 18}, /* 37 */ 1564 {17981, 39, 18}, /* 38 */ 1565 {18955, 40, 18}, /* 39 */ 1566 {19965, 41, 17}, /* 40 */ 1567 {21013, 42, 17}, /* 41 */ 1568 {22101, 43, 17}, /* 42 */ 1569 {23230, 44, 17}, /* 43 */ 1570 {24402, 45, 16}, /* 44 */ 1571 {25618, 46, 16}, /* 45 */ 1572 {26881, 47, 16}, /* 46 */ 1573 {28193, 48, 16}, /* 47 */ 1574 {29557, 49, 15}, /* 48 */ 1575 {30975, 50, 15}, /* 49 */ 1576 {32450, 51, 15}, /* 50 */ 1577 {33986, 52, 15}, /* 51 */ 1578 {35586, 53, 14}, /* 52 */ 1579 {37253, 54, 14}, /* 53 */ 1580 {38992, 55, 14}, /* 54 */ 1581 {40808, 56, 14}, /* 55 */ 1582 {42707, 57, 13}, /* 56 */ 1583 {44694, 58, 13}, /* 57 */ 1584 {46776, 59, 13}, /* 58 */ 1585 {48961, 60, 13}, /* 59 */ 1586 {51258, 61, 13}, /* 60 */ 1587 {53677, 62, 12}, /* 61 */ 1588 {56230, 63, 12}, /* 62 */ 1589 {58932, 64, 12}, /* 63 */ 1590 {61799, 65, 12}, /* 64 */ 1591 {64851, 66, 11}, /* 65 */ 1592 {68113, 67, 11}, /* 66 */ 1593 {71617, 68, 11}, /* 67 */ 1594 {75401, 69, 10}, /* 68 */ 1595 {79517, 70, 10}, /* 69 */ 1596 {84035, 71, 10}, /* 70 */ 1597 {89053, 72, 10}, /* 71 */ 1598 {94717, 73, 9} /* 72 */ 1599 }; 1600 1601 static void 1602 sctp_hs_cwnd_increase(struct sctp_tcb *stcb, struct sctp_nets *net) 1603 { 1604 int cur_val, i, indx, incr; 1605 int old_cwnd = net->cwnd; 1606 1607 cur_val = net->cwnd >> 10; 1608 indx = SCTP_HS_TABLE_SIZE - 1; 1609 1610 if (cur_val < sctp_cwnd_adjust[0].cwnd) { 1611 /* normal mode */ 1612 if (net->net_ack > net->mtu) { 1613 net->cwnd += net->mtu; 1614 } else { 1615 net->cwnd += net->net_ack; 1616 } 1617 } else { 1618 for (i = net->last_hs_used; i < SCTP_HS_TABLE_SIZE; i++) { 1619 if (cur_val < sctp_cwnd_adjust[i].cwnd) { 1620 indx = i; 1621 break; 1622 } 1623 } 1624 net->last_hs_used = indx; 1625 incr = (((int32_t)sctp_cwnd_adjust[indx].increase) << 10); 1626 net->cwnd += incr; 1627 } 1628 sctp_enforce_cwnd_limit(&stcb->asoc, net); 1629 if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_CWND_MONITOR_ENABLE) { 1630 sctp_log_cwnd(stcb, net, (net->cwnd - old_cwnd), SCTP_CWND_LOG_FROM_SS); 1631 } 1632 } 1633 1634 static void 1635 sctp_hs_cwnd_decrease(struct sctp_tcb *stcb, struct sctp_nets *net) 1636 { 1637 int cur_val, i, indx; 1638 int old_cwnd = net->cwnd; 1639 1640 cur_val = net->cwnd >> 10; 1641 if (cur_val < sctp_cwnd_adjust[0].cwnd) { 1642 /* normal mode */ 1643 net->ssthresh = net->cwnd / 2; 1644 if (net->ssthresh < (net->mtu * 2)) { 1645 net->ssthresh = 2 * net->mtu; 1646 } 1647 net->cwnd = net->ssthresh; 1648 } else { 1649 /* drop by the proper amount */ 1650 net->ssthresh = net->cwnd - (int)((net->cwnd / 100) * 1651 (int32_t)sctp_cwnd_adjust[net->last_hs_used].drop_percent); 1652 net->cwnd = net->ssthresh; 1653 /* now where are we */ 1654 indx = net->last_hs_used; 1655 cur_val = net->cwnd >> 10; 1656 /* reset where we are in the table */ 1657 if (cur_val < sctp_cwnd_adjust[0].cwnd) { 1658 /* feel out of hs */ 1659 net->last_hs_used = 0; 1660 } else { 1661 for (i = indx; i >= 1; i--) { 1662 if (cur_val > sctp_cwnd_adjust[i - 1].cwnd) { 1663 break; 1664 } 1665 } 1666 net->last_hs_used = indx; 1667 } 1668 } 1669 sctp_enforce_cwnd_limit(&stcb->asoc, net); 1670 if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_CWND_MONITOR_ENABLE) { 1671 sctp_log_cwnd(stcb, net, (net->cwnd - old_cwnd), SCTP_CWND_LOG_FROM_FR); 1672 } 1673 } 1674 1675 static void 1676 sctp_hs_cwnd_update_after_fr(struct sctp_tcb *stcb, 1677 struct sctp_association *asoc) 1678 { 1679 struct sctp_nets *net; 1680 1681 /* 1682 * CMT fast recovery code. Need to debug. ((sctp_cmt_on_off > 0) && 1683 * (net->fast_retran_loss_recovery == 0))) 1684 */ 1685 TAILQ_FOREACH(net, &asoc->nets, sctp_next) { 1686 if ((asoc->fast_retran_loss_recovery == 0) || 1687 (asoc->sctp_cmt_on_off > 0)) { 1688 /* out of a RFC2582 Fast recovery window? */ 1689 if (net->net_ack > 0) { 1690 /* 1691 * per section 7.2.3, are there any 1692 * destinations that had a fast retransmit 1693 * to them. If so what we need to do is 1694 * adjust ssthresh and cwnd. 1695 */ 1696 struct sctp_tmit_chunk *lchk; 1697 1698 sctp_hs_cwnd_decrease(stcb, net); 1699 1700 lchk = TAILQ_FIRST(&asoc->send_queue); 1701 1702 net->partial_bytes_acked = 0; 1703 /* Turn on fast recovery window */ 1704 asoc->fast_retran_loss_recovery = 1; 1705 if (lchk == NULL) { 1706 /* Mark end of the window */ 1707 asoc->fast_recovery_tsn = asoc->sending_seq - 1; 1708 } else { 1709 asoc->fast_recovery_tsn = lchk->rec.data.tsn - 1; 1710 } 1711 1712 /* 1713 * CMT fast recovery -- per destination 1714 * recovery variable. 1715 */ 1716 net->fast_retran_loss_recovery = 1; 1717 1718 if (lchk == NULL) { 1719 /* Mark end of the window */ 1720 net->fast_recovery_tsn = asoc->sending_seq - 1; 1721 } else { 1722 net->fast_recovery_tsn = lchk->rec.data.tsn - 1; 1723 } 1724 1725 sctp_timer_stop(SCTP_TIMER_TYPE_SEND, 1726 stcb->sctp_ep, stcb, net, 1727 SCTP_FROM_SCTP_CC_FUNCTIONS + SCTP_LOC_2); 1728 sctp_timer_start(SCTP_TIMER_TYPE_SEND, 1729 stcb->sctp_ep, stcb, net); 1730 } 1731 } else if (net->net_ack > 0) { 1732 /* 1733 * Mark a peg that we WOULD have done a cwnd 1734 * reduction but RFC2582 prevented this action. 1735 */ 1736 SCTP_STAT_INCR(sctps_fastretransinrtt); 1737 } 1738 } 1739 } 1740 1741 static void 1742 sctp_hs_cwnd_update_after_sack(struct sctp_tcb *stcb, 1743 struct sctp_association *asoc, 1744 int accum_moved, int reneged_all SCTP_UNUSED, int will_exit) 1745 { 1746 struct sctp_nets *net; 1747 1748 /******************************/ 1749 /* update cwnd and Early FR */ 1750 /******************************/ 1751 TAILQ_FOREACH(net, &asoc->nets, sctp_next) { 1752 #ifdef JANA_CMT_FAST_RECOVERY 1753 /* 1754 * CMT fast recovery code. Need to debug. 1755 */ 1756 if (net->fast_retran_loss_recovery && net->new_pseudo_cumack) { 1757 if (SCTP_TSN_GE(asoc->last_acked_seq, net->fast_recovery_tsn) || 1758 SCTP_TSN_GE(net->pseudo_cumack, net->fast_recovery_tsn)) { 1759 net->will_exit_fast_recovery = 1; 1760 } 1761 } 1762 #endif 1763 /* if nothing was acked on this destination skip it */ 1764 if (net->net_ack == 0) { 1765 if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_CWND_LOGGING_ENABLE) { 1766 sctp_log_cwnd(stcb, net, 0, SCTP_CWND_LOG_FROM_SACK); 1767 } 1768 continue; 1769 } 1770 #ifdef JANA_CMT_FAST_RECOVERY 1771 /* 1772 * CMT fast recovery code 1773 */ 1774 /* 1775 * if (sctp_cmt_on_off > 0 && net->fast_retran_loss_recovery 1776 * && net->will_exit_fast_recovery == 0) { @@@ Do something 1777 * } else if (sctp_cmt_on_off == 0 && 1778 * asoc->fast_retran_loss_recovery && will_exit == 0) { 1779 */ 1780 #endif 1781 1782 if (asoc->fast_retran_loss_recovery && 1783 (will_exit == 0) && 1784 (asoc->sctp_cmt_on_off == 0)) { 1785 /* 1786 * If we are in loss recovery we skip any cwnd 1787 * update 1788 */ 1789 return; 1790 } 1791 /* 1792 * CMT: CUC algorithm. Update cwnd if pseudo-cumack has 1793 * moved. 1794 */ 1795 if (accum_moved || 1796 ((asoc->sctp_cmt_on_off > 0) && net->new_pseudo_cumack)) { 1797 /* If the cumulative ack moved we can proceed */ 1798 if (net->cwnd <= net->ssthresh) { 1799 /* We are in slow start */ 1800 if (net->flight_size + net->net_ack >= net->cwnd) { 1801 sctp_hs_cwnd_increase(stcb, net); 1802 } else { 1803 if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_CWND_LOGGING_ENABLE) { 1804 sctp_log_cwnd(stcb, net, net->net_ack, 1805 SCTP_CWND_LOG_NOADV_SS); 1806 } 1807 } 1808 } else { 1809 /* We are in congestion avoidance */ 1810 net->partial_bytes_acked += net->net_ack; 1811 if ((net->flight_size + net->net_ack >= net->cwnd) && 1812 (net->partial_bytes_acked >= net->cwnd)) { 1813 net->partial_bytes_acked -= net->cwnd; 1814 net->cwnd += net->mtu; 1815 sctp_enforce_cwnd_limit(asoc, net); 1816 if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_CWND_MONITOR_ENABLE) { 1817 sctp_log_cwnd(stcb, net, net->mtu, 1818 SCTP_CWND_LOG_FROM_CA); 1819 } 1820 } else { 1821 if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_CWND_LOGGING_ENABLE) { 1822 sctp_log_cwnd(stcb, net, net->net_ack, 1823 SCTP_CWND_LOG_NOADV_CA); 1824 } 1825 } 1826 } 1827 } else { 1828 if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_CWND_LOGGING_ENABLE) { 1829 sctp_log_cwnd(stcb, net, net->mtu, 1830 SCTP_CWND_LOG_NO_CUMACK); 1831 } 1832 } 1833 } 1834 } 1835 1836 /* 1837 * H-TCP congestion control. The algorithm is detailed in: 1838 * R.N.Shorten, D.J.Leith: 1839 * "H-TCP: TCP for high-speed and long-distance networks" 1840 * Proc. PFLDnet, Argonne, 2004. 1841 * http://www.hamilton.ie/net/htcp3.pdf 1842 */ 1843 1844 static int use_rtt_scaling = 1; 1845 static int use_bandwidth_switch = 1; 1846 1847 static inline int 1848 between(uint32_t seq1, uint32_t seq2, uint32_t seq3) 1849 { 1850 return (seq3 - seq2 >= seq1 - seq2); 1851 } 1852 1853 static inline uint32_t 1854 htcp_cong_time(struct htcp *ca) 1855 { 1856 return (sctp_get_tick_count() - ca->last_cong); 1857 } 1858 1859 static inline uint32_t 1860 htcp_ccount(struct htcp *ca) 1861 { 1862 return (ca->minRTT == 0 ? htcp_cong_time(ca) : htcp_cong_time(ca) / ca->minRTT); 1863 } 1864 1865 static inline void 1866 htcp_reset(struct htcp *ca) 1867 { 1868 ca->undo_last_cong = ca->last_cong; 1869 ca->undo_maxRTT = ca->maxRTT; 1870 ca->undo_old_maxB = ca->old_maxB; 1871 ca->last_cong = sctp_get_tick_count(); 1872 } 1873 1874 #ifdef SCTP_NOT_USED 1875 1876 static uint32_t 1877 htcp_cwnd_undo(struct sctp_tcb *stcb, struct sctp_nets *net) 1878 { 1879 net->cc_mod.htcp_ca.last_cong = net->cc_mod.htcp_ca.undo_last_cong; 1880 net->cc_mod.htcp_ca.maxRTT = net->cc_mod.htcp_ca.undo_maxRTT; 1881 net->cc_mod.htcp_ca.old_maxB = net->cc_mod.htcp_ca.undo_old_maxB; 1882 return (max(net->cwnd, ((net->ssthresh / net->mtu << 7) / net->cc_mod.htcp_ca.beta) * net->mtu)); 1883 } 1884 1885 #endif 1886 1887 static inline void 1888 measure_rtt(struct sctp_nets *net) 1889 { 1890 uint32_t srtt = net->lastsa >> SCTP_RTT_SHIFT; 1891 1892 /* keep track of minimum RTT seen so far, minRTT is zero at first */ 1893 if (net->cc_mod.htcp_ca.minRTT > srtt || !net->cc_mod.htcp_ca.minRTT) 1894 net->cc_mod.htcp_ca.minRTT = srtt; 1895 1896 /* max RTT */ 1897 if (net->fast_retran_ip == 0 && net->ssthresh < 0xFFFF && htcp_ccount(&net->cc_mod.htcp_ca) > 3) { 1898 if (net->cc_mod.htcp_ca.maxRTT < net->cc_mod.htcp_ca.minRTT) 1899 net->cc_mod.htcp_ca.maxRTT = net->cc_mod.htcp_ca.minRTT; 1900 if (net->cc_mod.htcp_ca.maxRTT < srtt && srtt <= net->cc_mod.htcp_ca.maxRTT + sctp_msecs_to_ticks(20)) 1901 net->cc_mod.htcp_ca.maxRTT = srtt; 1902 } 1903 } 1904 1905 static void 1906 measure_achieved_throughput(struct sctp_nets *net) 1907 { 1908 uint32_t now = sctp_get_tick_count(); 1909 1910 if (net->fast_retran_ip == 0) 1911 net->cc_mod.htcp_ca.bytes_acked = net->net_ack; 1912 1913 if (!use_bandwidth_switch) 1914 return; 1915 1916 /* achieved throughput calculations */ 1917 /* JRS - not 100% sure of this statement */ 1918 if (net->fast_retran_ip == 1) { 1919 net->cc_mod.htcp_ca.bytecount = 0; 1920 net->cc_mod.htcp_ca.lasttime = now; 1921 return; 1922 } 1923 1924 net->cc_mod.htcp_ca.bytecount += net->net_ack; 1925 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)) && 1926 (now - net->cc_mod.htcp_ca.lasttime >= net->cc_mod.htcp_ca.minRTT) && 1927 (net->cc_mod.htcp_ca.minRTT > 0)) { 1928 uint32_t cur_Bi = net->cc_mod.htcp_ca.bytecount / net->mtu * hz / (now - net->cc_mod.htcp_ca.lasttime); 1929 1930 if (htcp_ccount(&net->cc_mod.htcp_ca) <= 3) { 1931 /* just after backoff */ 1932 net->cc_mod.htcp_ca.minB = net->cc_mod.htcp_ca.maxB = net->cc_mod.htcp_ca.Bi = cur_Bi; 1933 } else { 1934 net->cc_mod.htcp_ca.Bi = (3 * net->cc_mod.htcp_ca.Bi + cur_Bi) / 4; 1935 if (net->cc_mod.htcp_ca.Bi > net->cc_mod.htcp_ca.maxB) 1936 net->cc_mod.htcp_ca.maxB = net->cc_mod.htcp_ca.Bi; 1937 if (net->cc_mod.htcp_ca.minB > net->cc_mod.htcp_ca.maxB) 1938 net->cc_mod.htcp_ca.minB = net->cc_mod.htcp_ca.maxB; 1939 } 1940 net->cc_mod.htcp_ca.bytecount = 0; 1941 net->cc_mod.htcp_ca.lasttime = now; 1942 } 1943 } 1944 1945 static inline void 1946 htcp_beta_update(struct htcp *ca, uint32_t minRTT, uint32_t maxRTT) 1947 { 1948 if (use_bandwidth_switch) { 1949 uint32_t maxB = ca->maxB; 1950 uint32_t old_maxB = ca->old_maxB; 1951 1952 ca->old_maxB = ca->maxB; 1953 1954 if (!between(5 * maxB, 4 * old_maxB, 6 * old_maxB)) { 1955 ca->beta = BETA_MIN; 1956 ca->modeswitch = 0; 1957 return; 1958 } 1959 } 1960 1961 if (ca->modeswitch && minRTT > sctp_msecs_to_ticks(10) && maxRTT) { 1962 ca->beta = (minRTT << 7) / maxRTT; 1963 if (ca->beta < BETA_MIN) 1964 ca->beta = BETA_MIN; 1965 else if (ca->beta > BETA_MAX) 1966 ca->beta = BETA_MAX; 1967 } else { 1968 ca->beta = BETA_MIN; 1969 ca->modeswitch = 1; 1970 } 1971 } 1972 1973 static inline void 1974 htcp_alpha_update(struct htcp *ca) 1975 { 1976 uint32_t minRTT = ca->minRTT; 1977 uint32_t factor = 1; 1978 uint32_t diff = htcp_cong_time(ca); 1979 1980 if (diff > (uint32_t)hz) { 1981 diff -= hz; 1982 factor = 1 + (10 * diff + ((diff / 2) * (diff / 2) / hz)) / hz; 1983 } 1984 1985 if (use_rtt_scaling && minRTT) { 1986 uint32_t scale = (hz << 3) / (10 * minRTT); 1987 1988 scale = min(max(scale, 1U << 2), 10U << 3); /* clamping ratio to 1989 * interval [0.5,10]<<3 */ 1990 factor = (factor << 3) / scale; 1991 if (factor != 0) 1992 factor = 1; 1993 } 1994 1995 ca->alpha = 2 * factor * ((1 << 7) - ca->beta); 1996 if (ca->alpha != 0) 1997 ca->alpha = ALPHA_BASE; 1998 } 1999 2000 /* After we have the rtt data to calculate beta, we'd still prefer to wait one 2001 * rtt before we adjust our beta to ensure we are working from a consistent 2002 * data. 2003 * 2004 * This function should be called when we hit a congestion event since only at 2005 * that point do we really have a real sense of maxRTT (the queues en route 2006 * were getting just too full now). 2007 */ 2008 static void 2009 htcp_param_update(struct sctp_nets *net) 2010 { 2011 uint32_t minRTT = net->cc_mod.htcp_ca.minRTT; 2012 uint32_t maxRTT = net->cc_mod.htcp_ca.maxRTT; 2013 2014 htcp_beta_update(&net->cc_mod.htcp_ca, minRTT, maxRTT); 2015 htcp_alpha_update(&net->cc_mod.htcp_ca); 2016 2017 /* 2018 * add slowly fading memory for maxRTT to accommodate routing 2019 * changes etc 2020 */ 2021 if (minRTT > 0 && maxRTT > minRTT) 2022 net->cc_mod.htcp_ca.maxRTT = minRTT + ((maxRTT - minRTT) * 95) / 100; 2023 } 2024 2025 static uint32_t 2026 htcp_recalc_ssthresh(struct sctp_nets *net) 2027 { 2028 htcp_param_update(net); 2029 return (max(((net->cwnd / net->mtu * net->cc_mod.htcp_ca.beta) >> 7) * net->mtu, 2U * net->mtu)); 2030 } 2031 2032 static void 2033 htcp_cong_avoid(struct sctp_tcb *stcb, struct sctp_nets *net) 2034 { 2035 /*- 2036 * How to handle these functions? 2037 * if (!tcp_is_cwnd_limited(sk, in_flight)) RRS - good question. 2038 * return; 2039 */ 2040 if (net->cwnd <= net->ssthresh) { 2041 /* We are in slow start */ 2042 if (net->flight_size + net->net_ack >= net->cwnd) { 2043 if (net->net_ack > (net->mtu * SCTP_BASE_SYSCTL(sctp_L2_abc_variable))) { 2044 net->cwnd += (net->mtu * SCTP_BASE_SYSCTL(sctp_L2_abc_variable)); 2045 if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_CWND_MONITOR_ENABLE) { 2046 sctp_log_cwnd(stcb, net, net->mtu, 2047 SCTP_CWND_LOG_FROM_SS); 2048 } 2049 2050 } else { 2051 net->cwnd += net->net_ack; 2052 if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_CWND_MONITOR_ENABLE) { 2053 sctp_log_cwnd(stcb, net, net->net_ack, 2054 SCTP_CWND_LOG_FROM_SS); 2055 } 2056 } 2057 sctp_enforce_cwnd_limit(&stcb->asoc, net); 2058 } else { 2059 if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_CWND_LOGGING_ENABLE) { 2060 sctp_log_cwnd(stcb, net, net->net_ack, 2061 SCTP_CWND_LOG_NOADV_SS); 2062 } 2063 } 2064 } else { 2065 measure_rtt(net); 2066 2067 /* 2068 * In dangerous area, increase slowly. In theory this is 2069 * net->cwnd += alpha / net->cwnd 2070 */ 2071 /* What is snd_cwnd_cnt?? */ 2072 if (((net->partial_bytes_acked / net->mtu * net->cc_mod.htcp_ca.alpha) >> 7) * net->mtu >= net->cwnd) { 2073 /*- 2074 * Does SCTP have a cwnd clamp? 2075 * if (net->snd_cwnd < net->snd_cwnd_clamp) - Nope (RRS). 2076 */ 2077 net->cwnd += net->mtu; 2078 net->partial_bytes_acked = 0; 2079 sctp_enforce_cwnd_limit(&stcb->asoc, net); 2080 htcp_alpha_update(&net->cc_mod.htcp_ca); 2081 if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_CWND_MONITOR_ENABLE) { 2082 sctp_log_cwnd(stcb, net, net->mtu, 2083 SCTP_CWND_LOG_FROM_CA); 2084 } 2085 } else { 2086 net->partial_bytes_acked += net->net_ack; 2087 if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_CWND_LOGGING_ENABLE) { 2088 sctp_log_cwnd(stcb, net, net->net_ack, 2089 SCTP_CWND_LOG_NOADV_CA); 2090 } 2091 } 2092 2093 net->cc_mod.htcp_ca.bytes_acked = net->mtu; 2094 } 2095 } 2096 2097 #ifdef SCTP_NOT_USED 2098 /* Lower bound on congestion window. */ 2099 static uint32_t 2100 htcp_min_cwnd(struct sctp_tcb *stcb, struct sctp_nets *net) 2101 { 2102 return (net->ssthresh); 2103 } 2104 #endif 2105 2106 static void 2107 htcp_init(struct sctp_nets *net) 2108 { 2109 memset(&net->cc_mod.htcp_ca, 0, sizeof(struct htcp)); 2110 net->cc_mod.htcp_ca.alpha = ALPHA_BASE; 2111 net->cc_mod.htcp_ca.beta = BETA_MIN; 2112 net->cc_mod.htcp_ca.bytes_acked = net->mtu; 2113 net->cc_mod.htcp_ca.last_cong = sctp_get_tick_count(); 2114 } 2115 2116 static void 2117 sctp_htcp_set_initial_cc_param(struct sctp_tcb *stcb, struct sctp_nets *net) 2118 { 2119 /* 2120 * We take the max of the burst limit times a MTU or the 2121 * INITIAL_CWND. We then limit this to 4 MTU's of sending. 2122 */ 2123 net->cwnd = min((net->mtu * 4), max((2 * net->mtu), SCTP_INITIAL_CWND)); 2124 net->ssthresh = stcb->asoc.peers_rwnd; 2125 sctp_enforce_cwnd_limit(&stcb->asoc, net); 2126 htcp_init(net); 2127 2128 if (SCTP_BASE_SYSCTL(sctp_logging_level) & (SCTP_CWND_MONITOR_ENABLE | SCTP_CWND_LOGGING_ENABLE)) { 2129 sctp_log_cwnd(stcb, net, 0, SCTP_CWND_INITIALIZATION); 2130 } 2131 } 2132 2133 static void 2134 sctp_htcp_cwnd_update_after_sack(struct sctp_tcb *stcb, 2135 struct sctp_association *asoc, 2136 int accum_moved, int reneged_all SCTP_UNUSED, int will_exit) 2137 { 2138 struct sctp_nets *net; 2139 2140 /******************************/ 2141 /* update cwnd and Early FR */ 2142 /******************************/ 2143 TAILQ_FOREACH(net, &asoc->nets, sctp_next) { 2144 #ifdef JANA_CMT_FAST_RECOVERY 2145 /* 2146 * CMT fast recovery code. Need to debug. 2147 */ 2148 if (net->fast_retran_loss_recovery && net->new_pseudo_cumack) { 2149 if (SCTP_TSN_GE(asoc->last_acked_seq, net->fast_recovery_tsn) || 2150 SCTP_TSN_GE(net->pseudo_cumack, net->fast_recovery_tsn)) { 2151 net->will_exit_fast_recovery = 1; 2152 } 2153 } 2154 #endif 2155 /* if nothing was acked on this destination skip it */ 2156 if (net->net_ack == 0) { 2157 if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_CWND_LOGGING_ENABLE) { 2158 sctp_log_cwnd(stcb, net, 0, SCTP_CWND_LOG_FROM_SACK); 2159 } 2160 continue; 2161 } 2162 #ifdef JANA_CMT_FAST_RECOVERY 2163 /* 2164 * CMT fast recovery code 2165 */ 2166 /* 2167 * if (sctp_cmt_on_off > 0 && net->fast_retran_loss_recovery 2168 * && net->will_exit_fast_recovery == 0) { @@@ Do something 2169 * } else if (sctp_cmt_on_off == 0 && 2170 * asoc->fast_retran_loss_recovery && will_exit == 0) { 2171 */ 2172 #endif 2173 2174 if (asoc->fast_retran_loss_recovery && 2175 will_exit == 0 && 2176 (asoc->sctp_cmt_on_off == 0)) { 2177 /* 2178 * If we are in loss recovery we skip any cwnd 2179 * update 2180 */ 2181 return; 2182 } 2183 /* 2184 * CMT: CUC algorithm. Update cwnd if pseudo-cumack has 2185 * moved. 2186 */ 2187 if (accum_moved || 2188 ((asoc->sctp_cmt_on_off > 0) && net->new_pseudo_cumack)) { 2189 htcp_cong_avoid(stcb, net); 2190 measure_achieved_throughput(net); 2191 } else { 2192 if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_CWND_LOGGING_ENABLE) { 2193 sctp_log_cwnd(stcb, net, net->mtu, 2194 SCTP_CWND_LOG_NO_CUMACK); 2195 } 2196 } 2197 } 2198 } 2199 2200 static void 2201 sctp_htcp_cwnd_update_after_fr(struct sctp_tcb *stcb, 2202 struct sctp_association *asoc) 2203 { 2204 struct sctp_nets *net; 2205 2206 /* 2207 * CMT fast recovery code. Need to debug. ((sctp_cmt_on_off > 0) && 2208 * (net->fast_retran_loss_recovery == 0))) 2209 */ 2210 TAILQ_FOREACH(net, &asoc->nets, sctp_next) { 2211 if ((asoc->fast_retran_loss_recovery == 0) || 2212 (asoc->sctp_cmt_on_off > 0)) { 2213 /* out of a RFC2582 Fast recovery window? */ 2214 if (net->net_ack > 0) { 2215 /* 2216 * per section 7.2.3, are there any 2217 * destinations that had a fast retransmit 2218 * to them. If so what we need to do is 2219 * adjust ssthresh and cwnd. 2220 */ 2221 struct sctp_tmit_chunk *lchk; 2222 int old_cwnd = net->cwnd; 2223 2224 /* JRS - reset as if state were changed */ 2225 htcp_reset(&net->cc_mod.htcp_ca); 2226 net->ssthresh = htcp_recalc_ssthresh(net); 2227 net->cwnd = net->ssthresh; 2228 sctp_enforce_cwnd_limit(asoc, net); 2229 if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_CWND_MONITOR_ENABLE) { 2230 sctp_log_cwnd(stcb, net, (net->cwnd - old_cwnd), 2231 SCTP_CWND_LOG_FROM_FR); 2232 } 2233 lchk = TAILQ_FIRST(&asoc->send_queue); 2234 2235 net->partial_bytes_acked = 0; 2236 /* Turn on fast recovery window */ 2237 asoc->fast_retran_loss_recovery = 1; 2238 if (lchk == NULL) { 2239 /* Mark end of the window */ 2240 asoc->fast_recovery_tsn = asoc->sending_seq - 1; 2241 } else { 2242 asoc->fast_recovery_tsn = lchk->rec.data.tsn - 1; 2243 } 2244 2245 /* 2246 * CMT fast recovery -- per destination 2247 * recovery variable. 2248 */ 2249 net->fast_retran_loss_recovery = 1; 2250 2251 if (lchk == NULL) { 2252 /* Mark end of the window */ 2253 net->fast_recovery_tsn = asoc->sending_seq - 1; 2254 } else { 2255 net->fast_recovery_tsn = lchk->rec.data.tsn - 1; 2256 } 2257 2258 sctp_timer_stop(SCTP_TIMER_TYPE_SEND, 2259 stcb->sctp_ep, stcb, net, 2260 SCTP_FROM_SCTP_CC_FUNCTIONS + SCTP_LOC_3); 2261 sctp_timer_start(SCTP_TIMER_TYPE_SEND, 2262 stcb->sctp_ep, stcb, net); 2263 } 2264 } else if (net->net_ack > 0) { 2265 /* 2266 * Mark a peg that we WOULD have done a cwnd 2267 * reduction but RFC2582 prevented this action. 2268 */ 2269 SCTP_STAT_INCR(sctps_fastretransinrtt); 2270 } 2271 } 2272 } 2273 2274 static void 2275 sctp_htcp_cwnd_update_after_timeout(struct sctp_tcb *stcb, 2276 struct sctp_nets *net) 2277 { 2278 int old_cwnd = net->cwnd; 2279 2280 /* JRS - reset as if the state were being changed to timeout */ 2281 htcp_reset(&net->cc_mod.htcp_ca); 2282 net->ssthresh = htcp_recalc_ssthresh(net); 2283 net->cwnd = net->mtu; 2284 net->partial_bytes_acked = 0; 2285 if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_CWND_MONITOR_ENABLE) { 2286 sctp_log_cwnd(stcb, net, net->cwnd - old_cwnd, SCTP_CWND_LOG_FROM_RTX); 2287 } 2288 } 2289 2290 static void 2291 sctp_htcp_cwnd_update_after_ecn_echo(struct sctp_tcb *stcb, 2292 struct sctp_nets *net, int in_window, int num_pkt_lost SCTP_UNUSED) 2293 { 2294 int old_cwnd; 2295 2296 old_cwnd = net->cwnd; 2297 2298 /* JRS - reset hctp as if state changed */ 2299 if (in_window == 0) { 2300 htcp_reset(&net->cc_mod.htcp_ca); 2301 SCTP_STAT_INCR(sctps_ecnereducedcwnd); 2302 net->ssthresh = htcp_recalc_ssthresh(net); 2303 if (net->ssthresh < net->mtu) { 2304 net->ssthresh = net->mtu; 2305 /* here back off the timer as well, to slow us down */ 2306 net->RTO <<= 1; 2307 } 2308 net->cwnd = net->ssthresh; 2309 sctp_enforce_cwnd_limit(&stcb->asoc, net); 2310 if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_CWND_MONITOR_ENABLE) { 2311 sctp_log_cwnd(stcb, net, (net->cwnd - old_cwnd), SCTP_CWND_LOG_FROM_SAT); 2312 } 2313 } 2314 } 2315 2316 const struct sctp_cc_functions sctp_cc_functions[] = { 2317 { 2318 .sctp_set_initial_cc_param = sctp_set_initial_cc_param, 2319 .sctp_cwnd_update_after_sack = sctp_cwnd_update_after_sack, 2320 .sctp_cwnd_update_exit_pf = sctp_cwnd_update_exit_pf_common, 2321 .sctp_cwnd_update_after_fr = sctp_cwnd_update_after_fr, 2322 .sctp_cwnd_update_after_timeout = sctp_cwnd_update_after_timeout, 2323 .sctp_cwnd_update_after_ecn_echo = sctp_cwnd_update_after_ecn_echo, 2324 .sctp_cwnd_update_after_packet_dropped = sctp_cwnd_update_after_packet_dropped, 2325 .sctp_cwnd_update_after_output = sctp_cwnd_update_after_output, 2326 }, 2327 { 2328 .sctp_set_initial_cc_param = sctp_set_initial_cc_param, 2329 .sctp_cwnd_update_after_sack = sctp_hs_cwnd_update_after_sack, 2330 .sctp_cwnd_update_exit_pf = sctp_cwnd_update_exit_pf_common, 2331 .sctp_cwnd_update_after_fr = sctp_hs_cwnd_update_after_fr, 2332 .sctp_cwnd_update_after_timeout = sctp_cwnd_update_after_timeout, 2333 .sctp_cwnd_update_after_ecn_echo = sctp_cwnd_update_after_ecn_echo, 2334 .sctp_cwnd_update_after_packet_dropped = sctp_cwnd_update_after_packet_dropped, 2335 .sctp_cwnd_update_after_output = sctp_cwnd_update_after_output, 2336 }, 2337 { 2338 .sctp_set_initial_cc_param = sctp_htcp_set_initial_cc_param, 2339 .sctp_cwnd_update_after_sack = sctp_htcp_cwnd_update_after_sack, 2340 .sctp_cwnd_update_exit_pf = sctp_cwnd_update_exit_pf_common, 2341 .sctp_cwnd_update_after_fr = sctp_htcp_cwnd_update_after_fr, 2342 .sctp_cwnd_update_after_timeout = sctp_htcp_cwnd_update_after_timeout, 2343 .sctp_cwnd_update_after_ecn_echo = sctp_htcp_cwnd_update_after_ecn_echo, 2344 .sctp_cwnd_update_after_packet_dropped = sctp_cwnd_update_after_packet_dropped, 2345 .sctp_cwnd_update_after_output = sctp_cwnd_update_after_output, 2346 }, 2347 { 2348 .sctp_set_initial_cc_param = sctp_set_rtcc_initial_cc_param, 2349 .sctp_cwnd_update_after_sack = sctp_cwnd_update_rtcc_after_sack, 2350 .sctp_cwnd_update_exit_pf = sctp_cwnd_update_exit_pf_common, 2351 .sctp_cwnd_update_after_fr = sctp_cwnd_update_after_fr, 2352 .sctp_cwnd_update_after_timeout = sctp_cwnd_update_after_timeout, 2353 .sctp_cwnd_update_after_ecn_echo = sctp_cwnd_update_rtcc_after_ecn_echo, 2354 .sctp_cwnd_update_after_packet_dropped = sctp_cwnd_update_after_packet_dropped, 2355 .sctp_cwnd_update_after_output = sctp_cwnd_update_after_output, 2356 .sctp_cwnd_update_packet_transmitted = sctp_cwnd_update_rtcc_packet_transmitted, 2357 .sctp_cwnd_update_tsn_acknowledged = sctp_cwnd_update_rtcc_tsn_acknowledged, 2358 .sctp_cwnd_new_transmission_begins = sctp_cwnd_new_rtcc_transmission_begins, 2359 .sctp_cwnd_prepare_net_for_sack = sctp_cwnd_prepare_rtcc_net_for_sack, 2360 .sctp_cwnd_socket_option = sctp_cwnd_rtcc_socket_option, 2361 .sctp_rtt_calculated = sctp_rtt_rtcc_calculated 2362 } 2363 }; 2364