tcp_timer.c revision 1.51
1 /* $NetBSD: tcp_timer.c,v 1.51 2001/09/10 20:15:14 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 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 * 40 * Redistribution and use in source and binary forms, with or without 41 * modification, are permitted provided that the following conditions 42 * are met: 43 * 1. Redistributions of source code must retain the above copyright 44 * notice, this list of conditions and the following disclaimer. 45 * 2. Redistributions in binary form must reproduce the above copyright 46 * notice, this list of conditions and the following disclaimer in the 47 * documentation and/or other materials provided with the distribution. 48 * 3. All advertising materials mentioning features or use of this software 49 * must display the following acknowledgement: 50 * This product includes software developed by the NetBSD 51 * Foundation, Inc. and its contributors. 52 * 4. Neither the name of The NetBSD Foundation nor the names of its 53 * contributors may be used to endorse or promote products derived 54 * from this software without specific prior written permission. 55 * 56 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 57 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 58 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 59 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 60 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 61 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 62 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 63 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 64 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 65 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 66 * POSSIBILITY OF SUCH DAMAGE. 67 */ 68 69 /* 70 * Copyright (c) 1982, 1986, 1988, 1990, 1993, 1995 71 * The Regents of the University of California. All rights reserved. 72 * 73 * Redistribution and use in source and binary forms, with or without 74 * modification, are permitted provided that the following conditions 75 * are met: 76 * 1. Redistributions of source code must retain the above copyright 77 * notice, this list of conditions and the following disclaimer. 78 * 2. Redistributions in binary form must reproduce the above copyright 79 * notice, this list of conditions and the following disclaimer in the 80 * documentation and/or other materials provided with the distribution. 81 * 3. All advertising materials mentioning features or use of this software 82 * must display the following acknowledgement: 83 * This product includes software developed by the University of 84 * California, Berkeley and its contributors. 85 * 4. Neither the name of the University nor the names of its contributors 86 * may be used to endorse or promote products derived from this software 87 * without specific prior written permission. 88 * 89 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 90 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 91 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 92 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 93 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 94 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 95 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 96 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 97 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 98 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 99 * SUCH DAMAGE. 100 * 101 * @(#)tcp_timer.c 8.2 (Berkeley) 5/24/95 102 */ 103 104 #include "opt_inet.h" 105 #include "opt_tcp_debug.h" 106 107 #include <sys/param.h> 108 #include <sys/systm.h> 109 #include <sys/malloc.h> 110 #include <sys/mbuf.h> 111 #include <sys/socket.h> 112 #include <sys/socketvar.h> 113 #include <sys/protosw.h> 114 #include <sys/errno.h> 115 #include <sys/kernel.h> 116 117 #include <net/if.h> 118 #include <net/route.h> 119 120 #include <netinet/in.h> 121 #include <netinet/in_systm.h> 122 #include <netinet/ip.h> 123 #include <netinet/in_pcb.h> 124 #include <netinet/ip_var.h> 125 126 #ifdef INET6 127 #ifndef INET 128 #include <netinet/in.h> 129 #endif 130 #include <netinet/ip6.h> 131 #include <netinet6/in6_pcb.h> 132 #endif 133 134 #include <netinet/tcp.h> 135 #include <netinet/tcp_fsm.h> 136 #include <netinet/tcp_seq.h> 137 #include <netinet/tcp_timer.h> 138 #include <netinet/tcp_var.h> 139 #include <netinet/tcpip.h> 140 #ifdef TCP_DEBUG 141 #include <netinet/tcp_debug.h> 142 #endif 143 144 int tcp_keepidle = TCPTV_KEEP_IDLE; 145 int tcp_keepintvl = TCPTV_KEEPINTVL; 146 int tcp_keepcnt = TCPTV_KEEPCNT; /* max idle probes */ 147 int tcp_maxpersistidle = TCPTV_KEEP_IDLE; /* max idle time in persist */ 148 int tcp_maxidle; 149 150 /* 151 * Time to delay the ACK. This is initialized in tcp_init(), unless 152 * its patched. 153 */ 154 int tcp_delack_ticks = 0; 155 156 void tcp_timer_rexmt(void *); 157 void tcp_timer_persist(void *); 158 void tcp_timer_keep(void *); 159 void tcp_timer_2msl(void *); 160 161 tcp_timer_func_t tcp_timer_funcs[TCPT_NTIMERS] = { 162 tcp_timer_rexmt, 163 tcp_timer_persist, 164 tcp_timer_keep, 165 tcp_timer_2msl, 166 }; 167 168 /* 169 * Callout to process delayed ACKs for a TCPCB. 170 */ 171 void 172 tcp_delack(void *arg) 173 { 174 struct tcpcb *tp = arg; 175 int s; 176 177 /* 178 * If tcp_output() wasn't able to transmit the ACK 179 * for whatever reason, it will restart the delayed 180 * ACK callout. 181 */ 182 183 s = splsoftnet(); 184 tp->t_flags |= TF_ACKNOW; 185 (void) tcp_output(tp); 186 splx(s); 187 } 188 189 /* 190 * Tcp protocol timeout routine called every 500 ms. 191 * Updates the timers in all active tcb's and 192 * causes finite state machine actions if timers expire. 193 */ 194 void 195 tcp_slowtimo() 196 { 197 struct inpcb *inp, *ninp; 198 struct tcpcb *tp; 199 #ifdef INET6 200 struct in6pcb *in6p, *nin6p; 201 #endif 202 int s; 203 long i; 204 static int syn_cache_last = 0; 205 int skip, mask; 206 207 skip = mask = 0; 208 209 s = splsoftnet(); 210 tcp_maxidle = tcp_keepcnt * tcp_keepintvl; 211 /* 212 * Search through tcb's and update active timers. 213 */ 214 mask |= 1; 215 inp = tcbtable.inpt_queue.cqh_first; 216 if (inp == (struct inpcb *)0) { /* XXX */ 217 skip |= 1; 218 goto dotcb6; 219 } 220 for (; inp != (struct inpcb *)&tcbtable.inpt_queue; inp = ninp) { 221 ninp = inp->inp_queue.cqe_next; 222 tp = intotcpcb(inp); 223 if (tp == 0 || tp->t_state == TCPS_LISTEN) 224 continue; 225 for (i = 0; i < TCPT_NTIMERS; i++) { 226 if (TCP_TIMER_ISEXPIRED(tp, i)) { 227 TCP_TIMER_DISARM(tp, i); 228 (*(tcp_timer_funcs[i]))(tp); 229 /* XXX NOT MP SAFE */ 230 if ((ninp == (void *)&tcbtable.inpt_queue && 231 tcbtable.inpt_queue.cqh_last != inp) || 232 ninp->inp_queue.cqe_prev != inp) 233 goto tpgone; 234 } 235 } 236 tpgone: 237 ; 238 } 239 dotcb6: 240 #ifdef INET6 241 mask |= 2; 242 in6p = tcb6.in6p_next; 243 if (in6p == (struct in6pcb *)0) { /* XXX */ 244 skip |= 2; 245 goto doiss; 246 } 247 for (; in6p != (struct in6pcb *)&tcb6; in6p = nin6p) { 248 nin6p = in6p->in6p_next; 249 tp = in6totcpcb(in6p); 250 if (tp == 0 || tp->t_state == TCPS_LISTEN) 251 continue; 252 for (i = 0; i < TCPT_NTIMERS; i++) { 253 if (TCP_TIMER_ISEXPIRED(tp, i)) { 254 TCP_TIMER_DISARM(tp, i); 255 (*(tcp_timer_funcs[i]))(tp); 256 /* XXX NOT MP SAFE */ 257 if ((nin6p == (void *)&tcb6 && 258 tcb6.in6p_prev != in6p) || 259 nin6p->in6p_prev != in6p) 260 goto tp6gone; 261 } 262 } 263 tp6gone: 264 ; 265 } 266 267 doiss: 268 #endif 269 if (mask == skip) 270 goto done; 271 tcp_iss_seq += TCP_ISSINCR; /* increment iss */ 272 tcp_now++; /* for timestamps */ 273 if (++syn_cache_last >= tcp_syn_cache_interval) { 274 syn_cache_timer(); 275 syn_cache_last = 0; 276 } 277 done: 278 splx(s); 279 } 280 281 /* 282 * Cancel all timers for TCP tp. 283 */ 284 void 285 tcp_canceltimers(tp) 286 struct tcpcb *tp; 287 { 288 int i; 289 290 for (i = 0; i < TCPT_NTIMERS; i++) 291 TCP_TIMER_DISARM(tp, i); 292 } 293 294 int tcp_backoff[TCP_MAXRXTSHIFT + 1] = 295 { 1, 2, 4, 8, 16, 32, 64, 64, 64, 64, 64, 64, 64 }; 296 297 int tcp_totbackoff = 511; /* sum of tcp_backoff[] */ 298 299 /* 300 * TCP timer processing. 301 */ 302 303 void 304 tcp_timer_rexmt(void *arg) 305 { 306 struct tcpcb *tp = arg; 307 uint32_t rto; 308 int s; 309 #ifdef TCP_DEBUG 310 struct socket *so; 311 short ostate; 312 #endif 313 314 s = splsoftnet(); 315 316 #ifdef TCP_DEBUG 317 #ifdef INET 318 if (tp->t_inpcb) 319 so = tp->t_inpcb->inp_socket; 320 #endif 321 #ifdef INET6 322 if (tp->t_in6pcb) 323 so = tp->t_in6pcb->in6p_socket; 324 #endif 325 ostate = tp->t_state; 326 #endif /* TCP_DEBUG */ 327 328 /* 329 * Retransmission timer went off. Message has not 330 * been acked within retransmit interval. Back off 331 * to a longer retransmit interval and retransmit one segment. 332 */ 333 334 if (++tp->t_rxtshift > TCP_MAXRXTSHIFT) { 335 tp->t_rxtshift = TCP_MAXRXTSHIFT; 336 tcpstat.tcps_timeoutdrop++; 337 tp = tcp_drop(tp, tp->t_softerror ? 338 tp->t_softerror : ETIMEDOUT); 339 goto out; 340 } 341 tcpstat.tcps_rexmttimeo++; 342 rto = TCP_REXMTVAL(tp); 343 if (rto < tp->t_rttmin) 344 rto = tp->t_rttmin; 345 TCPT_RANGESET(tp->t_rxtcur, rto * tcp_backoff[tp->t_rxtshift], 346 tp->t_rttmin, TCPTV_REXMTMAX); 347 TCP_TIMER_ARM(tp, TCPT_REXMT, tp->t_rxtcur); 348 #if 0 349 /* 350 * If we are losing and we are trying path MTU discovery, 351 * try turning it off. This will avoid black holes in 352 * the network which suppress or fail to send "packet 353 * too big" ICMP messages. We should ideally do 354 * lots more sophisticated searching to find the right 355 * value here... 356 */ 357 if (ip_mtudisc && tp->t_rxtshift > TCP_MAXRXTSHIFT / 6) { 358 struct rtentry *rt = NULL; 359 360 #ifdef INET 361 if (tp->t_inpcb) 362 rt = in_pcbrtentry(tp->t_inpcb); 363 #endif 364 #ifdef INET6 365 if (tp->t_in6pcb) 366 rt = in6_pcbrtentry(tp->t_in6pcb); 367 #endif 368 369 /* XXX: Black hole recovery code goes here */ 370 } 371 #endif /* 0 */ 372 /* 373 * If losing, let the lower level know and try for 374 * a better route. Also, if we backed off this far, 375 * our srtt estimate is probably bogus. Clobber it 376 * so we'll take the next rtt measurement as our srtt; 377 * move the current srtt into rttvar to keep the current 378 * retransmit times until then. 379 */ 380 if (tp->t_rxtshift > TCP_MAXRXTSHIFT / 4) { 381 #ifdef INET 382 if (tp->t_inpcb) 383 in_losing(tp->t_inpcb); 384 #endif 385 #ifdef INET6 386 if (tp->t_in6pcb) 387 in6_losing(tp->t_in6pcb); 388 #endif 389 tp->t_rttvar += (tp->t_srtt >> TCP_RTT_SHIFT); 390 tp->t_srtt = 0; 391 } 392 tp->snd_nxt = tp->snd_una; 393 /* 394 * If timing a segment in this window, stop the timer. 395 */ 396 tp->t_rtttime = 0; 397 /* 398 * Remember if we are retransmitting a SYN, because if 399 * we do, set the initial congestion window must be set 400 * to 1 segment. 401 */ 402 if (tp->t_state == TCPS_SYN_SENT) 403 tp->t_flags |= TF_SYN_REXMT; 404 /* 405 * Close the congestion window down to one segment 406 * (we'll open it by one segment for each ack we get). 407 * Since we probably have a window's worth of unacked 408 * data accumulated, this "slow start" keeps us from 409 * dumping all that data as back-to-back packets (which 410 * might overwhelm an intermediate gateway). 411 * 412 * There are two phases to the opening: Initially we 413 * open by one mss on each ack. This makes the window 414 * size increase exponentially with time. If the 415 * window is larger than the path can handle, this 416 * exponential growth results in dropped packet(s) 417 * almost immediately. To get more time between 418 * drops but still "push" the network to take advantage 419 * of improving conditions, we switch from exponential 420 * to linear window opening at some threshhold size. 421 * For a threshhold, we use half the current window 422 * size, truncated to a multiple of the mss. 423 * 424 * (the minimum cwnd that will give us exponential 425 * growth is 2 mss. We don't allow the threshhold 426 * to go below this.) 427 */ 428 { 429 u_int win = min(tp->snd_wnd, tp->snd_cwnd) / 2 / tp->t_segsz; 430 if (win < 2) 431 win = 2; 432 /* Loss Window MUST be one segment. */ 433 tp->snd_cwnd = tp->t_segsz; 434 tp->snd_ssthresh = win * tp->t_segsz; 435 tp->t_dupacks = 0; 436 } 437 (void) tcp_output(tp); 438 439 out: 440 #ifdef TCP_DEBUG 441 if (tp && so->so_options & SO_DEBUG) 442 tcp_trace(TA_USER, ostate, tp, NULL, 443 PRU_SLOWTIMO | (TCPT_REXMT << 8)); 444 #endif 445 splx(s); 446 } 447 448 void 449 tcp_timer_persist(void *arg) 450 { 451 struct tcpcb *tp = arg; 452 struct socket *so; 453 uint32_t rto; 454 int s; 455 #ifdef TCP_DEBUG 456 short ostate; 457 #endif 458 459 s = splsoftnet(); 460 461 #ifdef INET 462 if (tp->t_inpcb) 463 so = tp->t_inpcb->inp_socket; 464 #endif 465 #ifdef INET6 466 if (tp->t_in6pcb) 467 so = tp->t_in6pcb->in6p_socket; 468 #endif 469 470 #ifdef TCP_DEBUG 471 ostate = tp->t_state; 472 #endif 473 474 /* 475 * Persistance timer into zero window. 476 * Force a byte to be output, if possible. 477 */ 478 479 /* 480 * Hack: if the peer is dead/unreachable, we do not 481 * time out if the window is closed. After a full 482 * backoff, drop the connection if the idle time 483 * (no responses to probes) reaches the maximum 484 * backoff that we would use if retransmitting. 485 */ 486 rto = TCP_REXMTVAL(tp); 487 if (rto < tp->t_rttmin) 488 rto = tp->t_rttmin; 489 if (tp->t_rxtshift == TCP_MAXRXTSHIFT && 490 ((tcp_now - tp->t_rcvtime) >= tcp_maxpersistidle || 491 (tcp_now - tp->t_rcvtime) >= rto * tcp_totbackoff)) { 492 tcpstat.tcps_persistdrops++; 493 tp = tcp_drop(tp, ETIMEDOUT); 494 goto out; 495 } 496 tcpstat.tcps_persisttimeo++; 497 tcp_setpersist(tp); 498 tp->t_force = 1; 499 (void) tcp_output(tp); 500 tp->t_force = 0; 501 502 out: 503 #ifdef TCP_DEBUG 504 if (tp && so->so_options & SO_DEBUG) 505 tcp_trace(TA_USER, ostate, tp, NULL, 506 PRU_SLOWTIMO | (TCPT_PERSIST << 8)); 507 #endif 508 splx(s); 509 } 510 511 void 512 tcp_timer_keep(void *arg) 513 { 514 struct tcpcb *tp = arg; 515 struct socket *so; 516 int s; 517 #ifdef TCP_DEBUG 518 short ostate; 519 #endif 520 521 s = splsoftnet(); 522 523 #ifdef TCP_DEBUG 524 ostate = tp->t_state; 525 #endif /* TCP_DEBUG */ 526 527 /* 528 * Keep-alive timer went off; send something 529 * or drop connection if idle for too long. 530 */ 531 532 tcpstat.tcps_keeptimeo++; 533 if (TCPS_HAVEESTABLISHED(tp->t_state) == 0) 534 goto dropit; 535 #ifdef INET 536 if (tp->t_inpcb) 537 so = tp->t_inpcb->inp_socket; 538 #endif 539 #ifdef INET6 540 if (tp->t_in6pcb) 541 so = tp->t_in6pcb->in6p_socket; 542 #endif 543 if (so->so_options & SO_KEEPALIVE && 544 tp->t_state <= TCPS_CLOSE_WAIT) { 545 if ((tcp_maxidle > 0) && 546 ((tcp_now - tp->t_rcvtime) >= 547 tcp_keepidle + tcp_maxidle)) 548 goto dropit; 549 /* 550 * Send a packet designed to force a response 551 * if the peer is up and reachable: 552 * either an ACK if the connection is still alive, 553 * or an RST if the peer has closed the connection 554 * due to timeout or reboot. 555 * Using sequence number tp->snd_una-1 556 * causes the transmitted zero-length segment 557 * to lie outside the receive window; 558 * by the protocol spec, this requires the 559 * correspondent TCP to respond. 560 */ 561 tcpstat.tcps_keepprobe++; 562 if (tcp_compat_42) { 563 /* 564 * The keepalive packet must have nonzero 565 * length to get a 4.2 host to respond. 566 */ 567 (void)tcp_respond(tp, tp->t_template, 568 (struct mbuf *)NULL, NULL, tp->rcv_nxt - 1, 569 tp->snd_una - 1, 0); 570 } else { 571 (void)tcp_respond(tp, tp->t_template, 572 (struct mbuf *)NULL, NULL, tp->rcv_nxt, 573 tp->snd_una - 1, 0); 574 } 575 TCP_TIMER_ARM(tp, TCPT_KEEP, tcp_keepintvl); 576 } else 577 TCP_TIMER_ARM(tp, TCPT_KEEP, tcp_keepidle); 578 579 #ifdef TCP_DEBUG 580 if (tp && so->so_options & SO_DEBUG) 581 tcp_trace(TA_USER, ostate, tp, NULL, 582 PRU_SLOWTIMO | (TCPT_KEEP << 8)); 583 #endif 584 splx(s); 585 return; 586 587 dropit: 588 tcpstat.tcps_keepdrops++; 589 (void) tcp_drop(tp, ETIMEDOUT); 590 splx(s); 591 } 592 593 void 594 tcp_timer_2msl(void *arg) 595 { 596 struct tcpcb *tp = arg; 597 struct socket *so; 598 int s; 599 #ifdef TCP_DEBUG 600 short ostate; 601 #endif 602 603 s = splsoftnet(); 604 605 #ifdef INET 606 if (tp->t_inpcb) 607 so = tp->t_inpcb->inp_socket; 608 #endif 609 #ifdef INET6 610 if (tp->t_in6pcb) 611 so = tp->t_in6pcb->in6p_socket; 612 #endif 613 614 #ifdef TCP_DEBUG 615 ostate = tp->t_state; 616 #endif 617 618 /* 619 * 2 MSL timeout in shutdown went off. If we're closed but 620 * still waiting for peer to close and connection has been idle 621 * too long, or if 2MSL time is up from TIME_WAIT, delete connection 622 * control block. Otherwise, check again in a bit. 623 */ 624 if (tp->t_state != TCPS_TIME_WAIT && 625 ((tcp_maxidle == 0) || ((tcp_now - tp->t_rcvtime) <= tcp_maxidle))) 626 TCP_TIMER_ARM(tp, TCPT_2MSL, tcp_keepintvl); 627 else 628 tp = tcp_close(tp); 629 630 #ifdef TCP_DEBUG 631 if (tp && so->so_options & SO_DEBUG) 632 tcp_trace(TA_USER, ostate, tp, NULL, 633 PRU_SLOWTIMO | (TCPT_2MSL << 8)); 634 #endif 635 splx(s); 636 } 637
Indexes created Tue Sep 23 02:09:52 GMT 2025