tcp_timer.c revision 1.79
1 /* $NetBSD: tcp_timer.c,v 1.79 2008/04/12 05:58:22 thorpej Exp $ */ 2 3 /* 4 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project. 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. Neither the name of the project nor the names of its contributors 16 * may be used to endorse or promote products derived from this software 17 * without specific prior written permission. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND 20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 22 * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE 23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29 * SUCH DAMAGE. 30 */ 31 32 /*- 33 * Copyright (c) 1997, 1998, 2001, 2005 The NetBSD Foundation, Inc. 34 * All rights reserved. 35 * 36 * This code is derived from software contributed to The NetBSD Foundation 37 * by Jason R. Thorpe and Kevin M. Lahey of the Numerical Aerospace Simulation 38 * Facility, NASA Ames Research Center. 39 * This code is derived from software contributed to The NetBSD Foundation 40 * by Charles M. Hannum. 41 * 42 * Redistribution and use in source and binary forms, with or without 43 * modification, are permitted provided that the following conditions 44 * are met: 45 * 1. Redistributions of source code must retain the above copyright 46 * notice, this list of conditions and the following disclaimer. 47 * 2. Redistributions in binary form must reproduce the above copyright 48 * notice, this list of conditions and the following disclaimer in the 49 * documentation and/or other materials provided with the distribution. 50 * 3. All advertising materials mentioning features or use of this software 51 * must display the following acknowledgement: 52 * This product includes software developed by the NetBSD 53 * Foundation, Inc. and its contributors. 54 * 4. Neither the name of The NetBSD Foundation nor the names of its 55 * contributors may be used to endorse or promote products derived 56 * from this software without specific prior written permission. 57 * 58 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 59 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 60 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 61 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 62 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 63 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 64 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 65 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 66 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 67 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 68 * POSSIBILITY OF SUCH DAMAGE. 69 */ 70 71 /* 72 * Copyright (c) 1982, 1986, 1988, 1990, 1993, 1995 73 * The Regents of the University of California. All rights reserved. 74 * 75 * Redistribution and use in source and binary forms, with or without 76 * modification, are permitted provided that the following conditions 77 * are met: 78 * 1. Redistributions of source code must retain the above copyright 79 * notice, this list of conditions and the following disclaimer. 80 * 2. Redistributions in binary form must reproduce the above copyright 81 * notice, this list of conditions and the following disclaimer in the 82 * documentation and/or other materials provided with the distribution. 83 * 3. Neither the name of the University nor the names of its contributors 84 * may be used to endorse or promote products derived from this software 85 * without specific prior written permission. 86 * 87 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 88 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 89 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 90 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 91 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 92 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 93 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 94 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 95 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 96 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 97 * SUCH DAMAGE. 98 * 99 * @(#)tcp_timer.c 8.2 (Berkeley) 5/24/95 100 */ 101 102 #include <sys/cdefs.h> 103 __KERNEL_RCSID(0, "$NetBSD: tcp_timer.c,v 1.79 2008/04/12 05:58:22 thorpej Exp $"); 104 105 #include "opt_inet.h" 106 #include "opt_tcp_debug.h" 107 108 #include <sys/param.h> 109 #include <sys/systm.h> 110 #include <sys/malloc.h> 111 #include <sys/mbuf.h> 112 #include <sys/socket.h> 113 #include <sys/socketvar.h> 114 #include <sys/protosw.h> 115 #include <sys/errno.h> 116 #include <sys/kernel.h> 117 118 #include <net/if.h> 119 #include <net/route.h> 120 121 #include <netinet/in.h> 122 #include <netinet/in_systm.h> 123 #include <netinet/ip.h> 124 #include <netinet/in_pcb.h> 125 #include <netinet/ip_var.h> 126 #include <netinet/ip_icmp.h> 127 128 #ifdef INET6 129 #ifndef INET 130 #include <netinet/in.h> 131 #endif 132 #include <netinet/ip6.h> 133 #include <netinet6/in6_pcb.h> 134 #endif 135 136 #include <netinet/tcp.h> 137 #include <netinet/tcp_fsm.h> 138 #include <netinet/tcp_seq.h> 139 #include <netinet/tcp_timer.h> 140 #include <netinet/tcp_var.h> 141 #include <netinet/tcp_private.h> 142 #include <netinet/tcp_congctl.h> 143 #include <netinet/tcpip.h> 144 #ifdef TCP_DEBUG 145 #include <netinet/tcp_debug.h> 146 #endif 147 148 /* 149 * Various tunable timer parameters. These are initialized in tcp_init(), 150 * unless they are patched. 151 */ 152 u_int tcp_keepinit = 0; 153 u_int tcp_keepidle = 0; 154 u_int tcp_keepintvl = 0; 155 u_int tcp_keepcnt = 0; /* max idle probes */ 156 157 int tcp_maxpersistidle = 0; /* max idle time in persist */ 158 159 /* 160 * Time to delay the ACK. This is initialized in tcp_init(), unless 161 * its patched. 162 */ 163 int tcp_delack_ticks = 0; 164 165 void tcp_timer_rexmt(void *); 166 void tcp_timer_persist(void *); 167 void tcp_timer_keep(void *); 168 void tcp_timer_2msl(void *); 169 170 const tcp_timer_func_t tcp_timer_funcs[TCPT_NTIMERS] = { 171 tcp_timer_rexmt, 172 tcp_timer_persist, 173 tcp_timer_keep, 174 tcp_timer_2msl, 175 }; 176 177 /* 178 * Timer state initialization, called from tcp_init(). 179 */ 180 void 181 tcp_timer_init(void) 182 { 183 184 if (tcp_keepinit == 0) 185 tcp_keepinit = TCPTV_KEEP_INIT; 186 187 if (tcp_keepidle == 0) 188 tcp_keepidle = TCPTV_KEEP_IDLE; 189 190 if (tcp_keepintvl == 0) 191 tcp_keepintvl = TCPTV_KEEPINTVL; 192 193 if (tcp_keepcnt == 0) 194 tcp_keepcnt = TCPTV_KEEPCNT; 195 196 if (tcp_maxpersistidle == 0) 197 tcp_maxpersistidle = TCPTV_KEEP_IDLE; 198 199 if (tcp_delack_ticks == 0) 200 tcp_delack_ticks = TCP_DELACK_TICKS; 201 } 202 203 /* 204 * Return how many timers are currently being invoked. 205 */ 206 int 207 tcp_timers_invoking(struct tcpcb *tp) 208 { 209 int i; 210 int count = 0; 211 212 for (i = 0; i < TCPT_NTIMERS; i++) 213 if (callout_invoking(&tp->t_timer[i])) 214 count++; 215 if (callout_invoking(&tp->t_delack_ch)) 216 count++; 217 218 return count; 219 } 220 221 /* 222 * Callout to process delayed ACKs for a TCPCB. 223 */ 224 void 225 tcp_delack(void *arg) 226 { 227 struct tcpcb *tp = arg; 228 int s; 229 230 /* 231 * If tcp_output() wasn't able to transmit the ACK 232 * for whatever reason, it will restart the delayed 233 * ACK callout. 234 */ 235 236 s = splsoftnet(); 237 callout_ack(&tp->t_delack_ch); 238 if (tcp_isdead(tp)) { 239 splx(s); 240 return; 241 } 242 243 tp->t_flags |= TF_ACKNOW; 244 (void) tcp_output(tp); 245 splx(s); 246 } 247 248 /* 249 * Tcp protocol timeout routine called every 500 ms. 250 * Updates the timers in all active tcb's and 251 * causes finite state machine actions if timers expire. 252 */ 253 void 254 tcp_slowtimo(void) 255 { 256 int s; 257 258 s = splsoftnet(); 259 tcp_iss_seq += TCP_ISSINCR; /* increment iss */ 260 tcp_now++; /* for timestamps */ 261 splx(s); 262 } 263 264 /* 265 * Cancel all timers for TCP tp. 266 */ 267 void 268 tcp_canceltimers(struct tcpcb *tp) 269 { 270 int i; 271 272 for (i = 0; i < TCPT_NTIMERS; i++) 273 TCP_TIMER_DISARM(tp, i); 274 } 275 276 const int tcp_backoff[TCP_MAXRXTSHIFT + 1] = 277 { 1, 2, 4, 8, 16, 32, 64, 64, 64, 64, 64, 64, 64 }; 278 279 const int tcp_totbackoff = 511; /* sum of tcp_backoff[] */ 280 281 /* 282 * TCP timer processing. 283 */ 284 285 void 286 tcp_timer_rexmt(void *arg) 287 { 288 struct tcpcb *tp = arg; 289 uint32_t rto; 290 int s; 291 #ifdef TCP_DEBUG 292 struct socket *so = NULL; 293 short ostate; 294 #endif 295 296 s = splsoftnet(); 297 callout_ack(&tp->t_timer[TCPT_REXMT]); 298 if (tcp_isdead(tp)) { 299 splx(s); 300 return; 301 } 302 303 if ((tp->t_flags & TF_PMTUD_PEND) && tp->t_inpcb && 304 SEQ_GEQ(tp->t_pmtud_th_seq, tp->snd_una) && 305 SEQ_LT(tp->t_pmtud_th_seq, (int)(tp->snd_una + tp->t_ourmss))) { 306 extern struct sockaddr_in icmpsrc; 307 struct icmp icmp; 308 309 tp->t_flags &= ~TF_PMTUD_PEND; 310 311 /* XXX create fake icmp message with relevant entries */ 312 icmp.icmp_nextmtu = tp->t_pmtud_nextmtu; 313 icmp.icmp_ip.ip_len = tp->t_pmtud_ip_len; 314 icmp.icmp_ip.ip_hl = tp->t_pmtud_ip_hl; 315 icmpsrc.sin_addr = tp->t_inpcb->inp_faddr; 316 icmp_mtudisc(&icmp, icmpsrc.sin_addr); 317 318 /* 319 * Notify all connections to the same peer about 320 * new mss and trigger retransmit. 321 */ 322 in_pcbnotifyall(&tcbtable, icmpsrc.sin_addr, EMSGSIZE, 323 tcp_mtudisc); 324 splx(s); 325 return; 326 } 327 #ifdef TCP_DEBUG 328 #ifdef INET 329 if (tp->t_inpcb) 330 so = tp->t_inpcb->inp_socket; 331 #endif 332 #ifdef INET6 333 if (tp->t_in6pcb) 334 so = tp->t_in6pcb->in6p_socket; 335 #endif 336 ostate = tp->t_state; 337 #endif /* TCP_DEBUG */ 338 339 /* 340 * Clear the SACK scoreboard, reset FACK estimate. 341 */ 342 tcp_free_sackholes(tp); 343 tp->snd_fack = tp->snd_una; 344 345 /* 346 * Retransmission timer went off. Message has not 347 * been acked within retransmit interval. Back off 348 * to a longer retransmit interval and retransmit one segment. 349 */ 350 351 if (++tp->t_rxtshift > TCP_MAXRXTSHIFT) { 352 tp->t_rxtshift = TCP_MAXRXTSHIFT; 353 TCP_STATINC(TCP_STAT_TIMEOUTDROP); 354 tp = tcp_drop(tp, tp->t_softerror ? 355 tp->t_softerror : ETIMEDOUT); 356 goto out; 357 } 358 TCP_STATINC(TCP_STAT_REXMTTIMEO); 359 rto = TCP_REXMTVAL(tp); 360 if (rto < tp->t_rttmin) 361 rto = tp->t_rttmin; 362 TCPT_RANGESET(tp->t_rxtcur, rto * tcp_backoff[tp->t_rxtshift], 363 tp->t_rttmin, TCPTV_REXMTMAX); 364 TCP_TIMER_ARM(tp, TCPT_REXMT, tp->t_rxtcur); 365 366 /* 367 * If we are losing and we are trying path MTU discovery, 368 * try turning it off. This will avoid black holes in 369 * the network which suppress or fail to send "packet 370 * too big" ICMP messages. We should ideally do 371 * lots more sophisticated searching to find the right 372 * value here... 373 */ 374 if (tp->t_mtudisc && tp->t_rxtshift > TCP_MAXRXTSHIFT / 6) { 375 TCP_STATINC(TCP_STAT_PMTUBLACKHOLE); 376 377 #ifdef INET 378 /* try turning PMTUD off */ 379 if (tp->t_inpcb) 380 tp->t_mtudisc = 0; 381 #endif 382 #ifdef INET6 383 /* try using IPv6 minimum MTU */ 384 if (tp->t_in6pcb) 385 tp->t_mtudisc = 0; 386 #endif 387 388 /* XXX: more sophisticated Black hole recovery code? */ 389 } 390 391 /* 392 * If losing, let the lower level know and try for 393 * a better route. Also, if we backed off this far, 394 * our srtt estimate is probably bogus. Clobber it 395 * so we'll take the next rtt measurement as our srtt; 396 * move the current srtt into rttvar to keep the current 397 * retransmit times until then. 398 */ 399 if (tp->t_rxtshift > TCP_MAXRXTSHIFT / 4) { 400 #ifdef INET 401 if (tp->t_inpcb) 402 in_losing(tp->t_inpcb); 403 #endif 404 #ifdef INET6 405 if (tp->t_in6pcb) 406 in6_losing(tp->t_in6pcb); 407 #endif 408 tp->t_rttvar += (tp->t_srtt >> TCP_RTT_SHIFT); 409 tp->t_srtt = 0; 410 } 411 tp->snd_nxt = tp->snd_una; 412 tp->snd_high = tp->snd_max; 413 /* 414 * If timing a segment in this window, stop the timer. 415 */ 416 tp->t_rtttime = 0; 417 /* 418 * Remember if we are retransmitting a SYN, because if 419 * we do, set the initial congestion window must be set 420 * to 1 segment. 421 */ 422 if (tp->t_state == TCPS_SYN_SENT) 423 tp->t_flags |= TF_SYN_REXMT; 424 425 /* 426 * Adjust congestion control parameters. 427 */ 428 tp->t_congctl->slow_retransmit(tp); 429 430 (void) tcp_output(tp); 431 432 out: 433 #ifdef TCP_DEBUG 434 if (tp && so->so_options & SO_DEBUG) 435 tcp_trace(TA_USER, ostate, tp, NULL, 436 PRU_SLOWTIMO | (TCPT_REXMT << 8)); 437 #endif 438 splx(s); 439 } 440 441 void 442 tcp_timer_persist(void *arg) 443 { 444 struct tcpcb *tp = arg; 445 uint32_t rto; 446 int s; 447 #ifdef TCP_DEBUG 448 struct socket *so = NULL; 449 short ostate; 450 #endif 451 452 s = splsoftnet(); 453 callout_ack(&tp->t_timer[TCPT_PERSIST]); 454 if (tcp_isdead(tp)) { 455 splx(s); 456 return; 457 } 458 459 #ifdef TCP_DEBUG 460 #ifdef INET 461 if (tp->t_inpcb) 462 so = tp->t_inpcb->inp_socket; 463 #endif 464 #ifdef INET6 465 if (tp->t_in6pcb) 466 so = tp->t_in6pcb->in6p_socket; 467 #endif 468 469 ostate = tp->t_state; 470 #endif /* TCP_DEBUG */ 471 472 /* 473 * Persistance timer into zero window. 474 * Force a byte to be output, if possible. 475 */ 476 477 /* 478 * Hack: if the peer is dead/unreachable, we do not 479 * time out if the window is closed. After a full 480 * backoff, drop the connection if the idle time 481 * (no responses to probes) reaches the maximum 482 * backoff that we would use if retransmitting. 483 */ 484 rto = TCP_REXMTVAL(tp); 485 if (rto < tp->t_rttmin) 486 rto = tp->t_rttmin; 487 if (tp->t_rxtshift == TCP_MAXRXTSHIFT && 488 ((tcp_now - tp->t_rcvtime) >= tcp_maxpersistidle || 489 (tcp_now - tp->t_rcvtime) >= rto * tcp_totbackoff)) { 490 TCP_STATINC(TCP_STAT_PERSISTDROPS); 491 tp = tcp_drop(tp, ETIMEDOUT); 492 goto out; 493 } 494 TCP_STATINC(TCP_STAT_PERSISTTIMEO); 495 tcp_setpersist(tp); 496 tp->t_force = 1; 497 (void) tcp_output(tp); 498 tp->t_force = 0; 499 500 out: 501 #ifdef TCP_DEBUG 502 if (tp && so->so_options & SO_DEBUG) 503 tcp_trace(TA_USER, ostate, tp, NULL, 504 PRU_SLOWTIMO | (TCPT_PERSIST << 8)); 505 #endif 506 splx(s); 507 } 508 509 void 510 tcp_timer_keep(void *arg) 511 { 512 struct tcpcb *tp = arg; 513 struct socket *so = NULL; /* Quell compiler warning */ 514 int s; 515 #ifdef TCP_DEBUG 516 short ostate; 517 #endif 518 519 s = splsoftnet(); 520 callout_ack(&tp->t_timer[TCPT_KEEP]); 521 if (tcp_isdead(tp)) { 522 splx(s); 523 return; 524 } 525 526 #ifdef TCP_DEBUG 527 ostate = tp->t_state; 528 #endif /* TCP_DEBUG */ 529 530 /* 531 * Keep-alive timer went off; send something 532 * or drop connection if idle for too long. 533 */ 534 535 TCP_STATINC(TCP_STAT_KEEPTIMEO); 536 if (TCPS_HAVEESTABLISHED(tp->t_state) == 0) 537 goto dropit; 538 #ifdef INET 539 if (tp->t_inpcb) 540 so = tp->t_inpcb->inp_socket; 541 #endif 542 #ifdef INET6 543 if (tp->t_in6pcb) 544 so = tp->t_in6pcb->in6p_socket; 545 #endif 546 KASSERT(so != NULL); 547 if (so->so_options & SO_KEEPALIVE && 548 tp->t_state <= TCPS_CLOSE_WAIT) { 549 if ((tp->t_maxidle > 0) && 550 ((tcp_now - tp->t_rcvtime) >= 551 tp->t_keepidle + tp->t_maxidle)) 552 goto dropit; 553 /* 554 * Send a packet designed to force a response 555 * if the peer is up and reachable: 556 * either an ACK if the connection is still alive, 557 * or an RST if the peer has closed the connection 558 * due to timeout or reboot. 559 * Using sequence number tp->snd_una-1 560 * causes the transmitted zero-length segment 561 * to lie outside the receive window; 562 * by the protocol spec, this requires the 563 * correspondent TCP to respond. 564 */ 565 TCP_STATINC(TCP_STAT_KEEPPROBE); 566 if (tcp_compat_42) { 567 /* 568 * The keepalive packet must have nonzero 569 * length to get a 4.2 host to respond. 570 */ 571 (void)tcp_respond(tp, tp->t_template, 572 (struct mbuf *)NULL, NULL, tp->rcv_nxt - 1, 573 tp->snd_una - 1, 0); 574 } else { 575 (void)tcp_respond(tp, tp->t_template, 576 (struct mbuf *)NULL, NULL, tp->rcv_nxt, 577 tp->snd_una - 1, 0); 578 } 579 TCP_TIMER_ARM(tp, TCPT_KEEP, tp->t_keepintvl); 580 } else 581 TCP_TIMER_ARM(tp, TCPT_KEEP, tp->t_keepidle); 582 583 #ifdef TCP_DEBUG 584 if (tp && so->so_options & SO_DEBUG) 585 tcp_trace(TA_USER, ostate, tp, NULL, 586 PRU_SLOWTIMO | (TCPT_KEEP << 8)); 587 #endif 588 splx(s); 589 return; 590 591 dropit: 592 TCP_STATINC(TCP_STAT_KEEPDROPS); 593 (void) tcp_drop(tp, ETIMEDOUT); 594 splx(s); 595 } 596 597 void 598 tcp_timer_2msl(void *arg) 599 { 600 struct tcpcb *tp = arg; 601 int s; 602 #ifdef TCP_DEBUG 603 struct socket *so = NULL; 604 short ostate; 605 #endif 606 607 s = splsoftnet(); 608 callout_ack(&tp->t_timer[TCPT_2MSL]); 609 if (tcp_isdead(tp)) { 610 splx(s); 611 return; 612 } 613 614 /* 615 * 2 MSL timeout went off, clear the SACK scoreboard, reset 616 * the FACK estimate. 617 */ 618 tcp_free_sackholes(tp); 619 tp->snd_fack = tp->snd_una; 620 621 #ifdef TCP_DEBUG 622 #ifdef INET 623 if (tp->t_inpcb) 624 so = tp->t_inpcb->inp_socket; 625 #endif 626 #ifdef INET6 627 if (tp->t_in6pcb) 628 so = tp->t_in6pcb->in6p_socket; 629 #endif 630 631 ostate = tp->t_state; 632 #endif /* TCP_DEBUG */ 633 634 /* 635 * 2 MSL timeout in shutdown went off. If we're closed but 636 * still waiting for peer to close and connection has been idle 637 * too long, or if 2MSL time is up from TIME_WAIT, delete connection 638 * control block. Otherwise, check again in a bit. 639 */ 640 if (tp->t_state != TCPS_TIME_WAIT && 641 ((tp->t_maxidle == 0) || 642 ((tcp_now - tp->t_rcvtime) <= tp->t_maxidle))) 643 TCP_TIMER_ARM(tp, TCPT_2MSL, tp->t_keepintvl); 644 else 645 tp = tcp_close(tp); 646 647 #ifdef TCP_DEBUG 648 if (tp && so->so_options & SO_DEBUG) 649 tcp_trace(TA_USER, ostate, tp, NULL, 650 PRU_SLOWTIMO | (TCPT_2MSL << 8)); 651 #endif 652 splx(s); 653 } 654
Indexes created Tue Sep 23 14:10:03 GMT 2025