1 /*- 2 * Copyright (c) 1982, 1986, 1988, 1990, 1993, 1995 3 * The Regents of the University of California. All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 4. Neither the name of the University nor the names of its contributors 14 * may be used to endorse or promote products derived from this software 15 * without specific prior written permission. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 20 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 27 * SUCH DAMAGE. 28 * 29 * @(#)tcp_timer.c 8.2 (Berkeley) 5/24/95 30 */ 31 32 #include <sys/cdefs.h> 33 __FBSDID("$FreeBSD$"); 34 35 #include "opt_inet6.h" 36 #include "opt_tcpdebug.h" 37 38 #include <sys/param.h> 39 #include <sys/kernel.h> 40 #include <sys/lock.h> 41 #include <sys/mbuf.h> 42 #include <sys/mutex.h> 43 #include <sys/protosw.h> 44 #include <sys/socket.h> 45 #include <sys/socketvar.h> 46 #include <sys/sysctl.h> 47 #include <sys/systm.h> 48 #include <sys/vimage.h> 49 50 #include <net/route.h> 51 52 #include <netinet/in.h> 53 #include <netinet/in_pcb.h> 54 #include <netinet/in_systm.h> 55 #ifdef INET6 56 #include <netinet6/in6_pcb.h> 57 #endif 58 #include <netinet/ip_var.h> 59 #include <netinet/tcp.h> 60 #include <netinet/tcp_fsm.h> 61 #include <netinet/tcp_timer.h> 62 #include <netinet/tcp_var.h> 63 #include <netinet/tcpip.h> 64 #ifdef TCPDEBUG 65 #include <netinet/tcp_debug.h> 66 #endif 67 68 int tcp_keepinit; 69 SYSCTL_PROC(_net_inet_tcp, TCPCTL_KEEPINIT, keepinit, CTLTYPE_INT|CTLFLAG_RW, 70 &tcp_keepinit, 0, sysctl_msec_to_ticks, "I", "time to establish connection"); 71 72 int tcp_keepidle; 73 SYSCTL_PROC(_net_inet_tcp, TCPCTL_KEEPIDLE, keepidle, CTLTYPE_INT|CTLFLAG_RW, 74 &tcp_keepidle, 0, sysctl_msec_to_ticks, "I", "time before keepalive probes begin"); 75 76 int tcp_keepintvl; 77 SYSCTL_PROC(_net_inet_tcp, TCPCTL_KEEPINTVL, keepintvl, CTLTYPE_INT|CTLFLAG_RW, 78 &tcp_keepintvl, 0, sysctl_msec_to_ticks, "I", "time between keepalive probes"); 79 80 int tcp_delacktime; 81 SYSCTL_PROC(_net_inet_tcp, TCPCTL_DELACKTIME, delacktime, CTLTYPE_INT|CTLFLAG_RW, 82 &tcp_delacktime, 0, sysctl_msec_to_ticks, "I", 83 "Time before a delayed ACK is sent"); 84 85 int tcp_msl; 86 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, msl, CTLTYPE_INT|CTLFLAG_RW, 87 &tcp_msl, 0, sysctl_msec_to_ticks, "I", "Maximum segment lifetime"); 88 89 int tcp_rexmit_min; 90 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, rexmit_min, CTLTYPE_INT|CTLFLAG_RW, 91 &tcp_rexmit_min, 0, sysctl_msec_to_ticks, "I", 92 "Minimum Retransmission Timeout"); 93 94 int tcp_rexmit_slop; 95 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, rexmit_slop, CTLTYPE_INT|CTLFLAG_RW, 96 &tcp_rexmit_slop, 0, sysctl_msec_to_ticks, "I", 97 "Retransmission Timer Slop"); 98 99 static int always_keepalive = 1; 100 SYSCTL_INT(_net_inet_tcp, OID_AUTO, always_keepalive, CTLFLAG_RW, 101 &always_keepalive , 0, "Assume SO_KEEPALIVE on all TCP connections"); 102 103 int tcp_fast_finwait2_recycle = 0; 104 SYSCTL_INT(_net_inet_tcp, OID_AUTO, fast_finwait2_recycle, CTLFLAG_RW, 105 &tcp_fast_finwait2_recycle, 0, 106 "Recycle closed FIN_WAIT_2 connections faster"); 107 108 int tcp_finwait2_timeout; 109 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, finwait2_timeout, CTLTYPE_INT|CTLFLAG_RW, 110 &tcp_finwait2_timeout, 0, sysctl_msec_to_ticks, "I", "FIN-WAIT2 timeout"); 111 112 113 static int tcp_keepcnt = TCPTV_KEEPCNT; 114 /* max idle probes */ 115 int tcp_maxpersistidle; 116 /* max idle time in persist */ 117 int tcp_maxidle; 118 119 /* 120 * Tcp protocol timeout routine called every 500 ms. 121 * Updates timestamps used for TCP 122 * causes finite state machine actions if timers expire. 123 */ 124 void 125 tcp_slowtimo(void) 126 { 127 128 tcp_maxidle = tcp_keepcnt * tcp_keepintvl; 129 INP_INFO_WLOCK(&V_tcbinfo); 130 (void) tcp_tw_2msl_scan(0); 131 INP_INFO_WUNLOCK(&V_tcbinfo); 132 } 133 134 int tcp_syn_backoff[TCP_MAXRXTSHIFT + 1] = 135 { 1, 1, 1, 1, 1, 2, 4, 8, 16, 32, 64, 64, 64 }; 136 137 int tcp_backoff[TCP_MAXRXTSHIFT + 1] = 138 { 1, 2, 4, 8, 16, 32, 64, 128, 256, 512, 512, 512, 512 }; 139 140 static int tcp_totbackoff = 2559; /* sum of tcp_backoff[] */ 141 142 static int tcp_timer_race; 143 SYSCTL_INT(_net_inet_tcp, OID_AUTO, timer_race, CTLFLAG_RD, &tcp_timer_race, 144 0, "Count of t_inpcb races on tcp_discardcb"); 145 146 /* 147 * TCP timer processing. 148 */ 149 150 void 151 tcp_timer_delack(void *xtp) 152 { 153 struct tcpcb *tp = xtp; 154 struct inpcb *inp; 155 156 INP_INFO_RLOCK(&V_tcbinfo); 157 inp = tp->t_inpcb; 158 /* 159 * XXXRW: While this assert is in fact correct, bugs in the tcpcb 160 * tear-down mean we need it as a work-around for races between 161 * timers and tcp_discardcb(). 162 * 163 * KASSERT(inp != NULL, ("tcp_timer_delack: inp == NULL")); 164 */ 165 if (inp == NULL) { 166 tcp_timer_race++; 167 INP_INFO_RUNLOCK(&V_tcbinfo); 168 return; 169 } 170 INP_WLOCK(inp); 171 INP_INFO_RUNLOCK(&V_tcbinfo); 172 if ((inp->inp_vflag & INP_DROPPED) || callout_pending(&tp->t_timers->tt_delack) 173 || !callout_active(&tp->t_timers->tt_delack)) { 174 INP_WUNLOCK(inp); 175 return; 176 } 177 callout_deactivate(&tp->t_timers->tt_delack); 178 179 tp->t_flags |= TF_ACKNOW; 180 V_tcpstat.tcps_delack++; 181 (void) tcp_output(tp); 182 INP_WUNLOCK(inp); 183 } 184 185 void 186 tcp_timer_2msl(void *xtp) 187 { 188 struct tcpcb *tp = xtp; 189 struct inpcb *inp; 190 #ifdef TCPDEBUG 191 int ostate; 192 193 ostate = tp->t_state; 194 #endif 195 /* 196 * XXXRW: Does this actually happen? 197 */ 198 INP_INFO_WLOCK(&V_tcbinfo); 199 inp = tp->t_inpcb; 200 /* 201 * XXXRW: While this assert is in fact correct, bugs in the tcpcb 202 * tear-down mean we need it as a work-around for races between 203 * timers and tcp_discardcb(). 204 * 205 * KASSERT(inp != NULL, ("tcp_timer_2msl: inp == NULL")); 206 */ 207 if (inp == NULL) { 208 tcp_timer_race++; 209 INP_INFO_WUNLOCK(&V_tcbinfo); 210 return; 211 } 212 INP_WLOCK(inp); 213 tcp_free_sackholes(tp); 214 if ((inp->inp_vflag & INP_DROPPED) || callout_pending(&tp->t_timers->tt_2msl) || 215 !callout_active(&tp->t_timers->tt_2msl)) { 216 INP_WUNLOCK(tp->t_inpcb); 217 INP_INFO_WUNLOCK(&V_tcbinfo); 218 return; 219 } 220 callout_deactivate(&tp->t_timers->tt_2msl); 221 /* 222 * 2 MSL timeout in shutdown went off. If we're closed but 223 * still waiting for peer to close and connection has been idle 224 * too long, or if 2MSL time is up from TIME_WAIT, delete connection 225 * control block. Otherwise, check again in a bit. 226 * 227 * If fastrecycle of FIN_WAIT_2, in FIN_WAIT_2 and receiver has closed, 228 * there's no point in hanging onto FIN_WAIT_2 socket. Just close it. 229 * Ignore fact that there were recent incoming segments. 230 */ 231 if (tcp_fast_finwait2_recycle && tp->t_state == TCPS_FIN_WAIT_2 && 232 tp->t_inpcb && tp->t_inpcb->inp_socket && 233 (tp->t_inpcb->inp_socket->so_rcv.sb_state & SBS_CANTRCVMORE)) { 234 V_tcpstat.tcps_finwait2_drops++; 235 tp = tcp_close(tp); 236 } else { 237 if (tp->t_state != TCPS_TIME_WAIT && 238 (ticks - tp->t_rcvtime) <= tcp_maxidle) 239 callout_reset(&tp->t_timers->tt_2msl, tcp_keepintvl, 240 tcp_timer_2msl, tp); 241 else 242 tp = tcp_close(tp); 243 } 244 245 #ifdef TCPDEBUG 246 if (tp != NULL && (tp->t_inpcb->inp_socket->so_options & SO_DEBUG)) 247 tcp_trace(TA_USER, ostate, tp, (void *)0, (struct tcphdr *)0, 248 PRU_SLOWTIMO); 249 #endif 250 if (tp != NULL) 251 INP_WUNLOCK(inp); 252 INP_INFO_WUNLOCK(&V_tcbinfo); 253 } 254 255 void 256 tcp_timer_keep(void *xtp) 257 { 258 struct tcpcb *tp = xtp; 259 struct tcptemp *t_template; 260 struct inpcb *inp; 261 #ifdef TCPDEBUG 262 int ostate; 263 264 ostate = tp->t_state; 265 #endif 266 INP_INFO_WLOCK(&V_tcbinfo); 267 inp = tp->t_inpcb; 268 /* 269 * XXXRW: While this assert is in fact correct, bugs in the tcpcb 270 * tear-down mean we need it as a work-around for races between 271 * timers and tcp_discardcb(). 272 * 273 * KASSERT(inp != NULL, ("tcp_timer_keep: inp == NULL")); 274 */ 275 if (inp == NULL) { 276 tcp_timer_race++; 277 INP_INFO_WUNLOCK(&V_tcbinfo); 278 return; 279 } 280 INP_WLOCK(inp); 281 if ((inp->inp_vflag & INP_DROPPED) || callout_pending(&tp->t_timers->tt_keep) 282 || !callout_active(&tp->t_timers->tt_keep)) { 283 INP_WUNLOCK(inp); 284 INP_INFO_WUNLOCK(&V_tcbinfo); 285 return; 286 } 287 callout_deactivate(&tp->t_timers->tt_keep); 288 /* 289 * Keep-alive timer went off; send something 290 * or drop connection if idle for too long. 291 */ 292 V_tcpstat.tcps_keeptimeo++; 293 if (tp->t_state < TCPS_ESTABLISHED) 294 goto dropit; 295 if ((always_keepalive || inp->inp_socket->so_options & SO_KEEPALIVE) && 296 tp->t_state <= TCPS_CLOSING) { 297 if ((ticks - tp->t_rcvtime) >= tcp_keepidle + tcp_maxidle) 298 goto dropit; 299 /* 300 * Send a packet designed to force a response 301 * if the peer is up and reachable: 302 * either an ACK if the connection is still alive, 303 * or an RST if the peer has closed the connection 304 * due to timeout or reboot. 305 * Using sequence number tp->snd_una-1 306 * causes the transmitted zero-length segment 307 * to lie outside the receive window; 308 * by the protocol spec, this requires the 309 * correspondent TCP to respond. 310 */ 311 V_tcpstat.tcps_keepprobe++; 312 t_template = tcpip_maketemplate(inp); 313 if (t_template) { 314 tcp_respond(tp, t_template->tt_ipgen, 315 &t_template->tt_t, (struct mbuf *)NULL, 316 tp->rcv_nxt, tp->snd_una - 1, 0); 317 free(t_template, M_TEMP); 318 } 319 callout_reset(&tp->t_timers->tt_keep, tcp_keepintvl, tcp_timer_keep, tp); 320 } else 321 callout_reset(&tp->t_timers->tt_keep, tcp_keepidle, tcp_timer_keep, tp); 322 323 #ifdef TCPDEBUG 324 if (inp->inp_socket->so_options & SO_DEBUG) 325 tcp_trace(TA_USER, ostate, tp, (void *)0, (struct tcphdr *)0, 326 PRU_SLOWTIMO); 327 #endif 328 INP_WUNLOCK(inp); 329 INP_INFO_WUNLOCK(&V_tcbinfo); 330 return; 331 332 dropit: 333 V_tcpstat.tcps_keepdrops++; 334 tp = tcp_drop(tp, ETIMEDOUT); 335 336 #ifdef TCPDEBUG 337 if (tp != NULL && (tp->t_inpcb->inp_socket->so_options & SO_DEBUG)) 338 tcp_trace(TA_USER, ostate, tp, (void *)0, (struct tcphdr *)0, 339 PRU_SLOWTIMO); 340 #endif 341 if (tp != NULL) 342 INP_WUNLOCK(tp->t_inpcb); 343 INP_INFO_WUNLOCK(&V_tcbinfo); 344 } 345 346 void 347 tcp_timer_persist(void *xtp) 348 { 349 struct tcpcb *tp = xtp; 350 struct inpcb *inp; 351 #ifdef TCPDEBUG 352 int ostate; 353 354 ostate = tp->t_state; 355 #endif 356 INP_INFO_WLOCK(&V_tcbinfo); 357 inp = tp->t_inpcb; 358 /* 359 * XXXRW: While this assert is in fact correct, bugs in the tcpcb 360 * tear-down mean we need it as a work-around for races between 361 * timers and tcp_discardcb(). 362 * 363 * KASSERT(inp != NULL, ("tcp_timer_persist: inp == NULL")); 364 */ 365 if (inp == NULL) { 366 tcp_timer_race++; 367 INP_INFO_WUNLOCK(&V_tcbinfo); 368 return; 369 } 370 INP_WLOCK(inp); 371 if ((inp->inp_vflag & INP_DROPPED) || callout_pending(&tp->t_timers->tt_persist) 372 || !callout_active(&tp->t_timers->tt_persist)) { 373 INP_WUNLOCK(inp); 374 INP_INFO_WUNLOCK(&V_tcbinfo); 375 return; 376 } 377 callout_deactivate(&tp->t_timers->tt_persist); 378 /* 379 * Persistance timer into zero window. 380 * Force a byte to be output, if possible. 381 */ 382 V_tcpstat.tcps_persisttimeo++; 383 /* 384 * Hack: if the peer is dead/unreachable, we do not 385 * time out if the window is closed. After a full 386 * backoff, drop the connection if the idle time 387 * (no responses to probes) reaches the maximum 388 * backoff that we would use if retransmitting. 389 */ 390 if (tp->t_rxtshift == TCP_MAXRXTSHIFT && 391 ((ticks - tp->t_rcvtime) >= tcp_maxpersistidle || 392 (ticks - tp->t_rcvtime) >= TCP_REXMTVAL(tp) * tcp_totbackoff)) { 393 V_tcpstat.tcps_persistdrop++; 394 tp = tcp_drop(tp, ETIMEDOUT); 395 goto out; 396 } 397 tcp_setpersist(tp); 398 tp->t_flags |= TF_FORCEDATA; 399 (void) tcp_output(tp); 400 tp->t_flags &= ~TF_FORCEDATA; 401 402 out: 403 #ifdef TCPDEBUG 404 if (tp != NULL && tp->t_inpcb->inp_socket->so_options & SO_DEBUG) 405 tcp_trace(TA_USER, ostate, tp, NULL, NULL, PRU_SLOWTIMO); 406 #endif 407 if (tp != NULL) 408 INP_WUNLOCK(inp); 409 INP_INFO_WUNLOCK(&V_tcbinfo); 410 } 411 412 void 413 tcp_timer_rexmt(void * xtp) 414 { 415 struct tcpcb *tp = xtp; 416 int rexmt; 417 int headlocked; 418 struct inpcb *inp; 419 #ifdef TCPDEBUG 420 int ostate; 421 422 ostate = tp->t_state; 423 #endif 424 INP_INFO_WLOCK(&V_tcbinfo); 425 headlocked = 1; 426 inp = tp->t_inpcb; 427 /* 428 * XXXRW: While this assert is in fact correct, bugs in the tcpcb 429 * tear-down mean we need it as a work-around for races between 430 * timers and tcp_discardcb(). 431 * 432 * KASSERT(inp != NULL, ("tcp_timer_rexmt: inp == NULL")); 433 */ 434 if (inp == NULL) { 435 tcp_timer_race++; 436 INP_INFO_WUNLOCK(&V_tcbinfo); 437 return; 438 } 439 INP_WLOCK(inp); 440 if ((inp->inp_vflag & INP_DROPPED) || callout_pending(&tp->t_timers->tt_rexmt) 441 || !callout_active(&tp->t_timers->tt_rexmt)) { 442 INP_WUNLOCK(inp); 443 INP_INFO_WUNLOCK(&V_tcbinfo); 444 return; 445 } 446 callout_deactivate(&tp->t_timers->tt_rexmt); 447 tcp_free_sackholes(tp); 448 /* 449 * Retransmission timer went off. Message has not 450 * been acked within retransmit interval. Back off 451 * to a longer retransmit interval and retransmit one segment. 452 */ 453 if (++tp->t_rxtshift > TCP_MAXRXTSHIFT) { 454 tp->t_rxtshift = TCP_MAXRXTSHIFT; 455 V_tcpstat.tcps_timeoutdrop++; 456 tp = tcp_drop(tp, tp->t_softerror ? 457 tp->t_softerror : ETIMEDOUT); 458 goto out; 459 } 460 INP_INFO_WUNLOCK(&V_tcbinfo); 461 headlocked = 0; 462 if (tp->t_rxtshift == 1) { 463 /* 464 * first retransmit; record ssthresh and cwnd so they can 465 * be recovered if this turns out to be a "bad" retransmit. 466 * A retransmit is considered "bad" if an ACK for this 467 * segment is received within RTT/2 interval; the assumption 468 * here is that the ACK was already in flight. See 469 * "On Estimating End-to-End Network Path Properties" by 470 * Allman and Paxson for more details. 471 */ 472 tp->snd_cwnd_prev = tp->snd_cwnd; 473 tp->snd_ssthresh_prev = tp->snd_ssthresh; 474 tp->snd_recover_prev = tp->snd_recover; 475 if (IN_FASTRECOVERY(tp)) 476 tp->t_flags |= TF_WASFRECOVERY; 477 else 478 tp->t_flags &= ~TF_WASFRECOVERY; 479 tp->t_badrxtwin = ticks + (tp->t_srtt >> (TCP_RTT_SHIFT + 1)); 480 } 481 V_tcpstat.tcps_rexmttimeo++; 482 if (tp->t_state == TCPS_SYN_SENT) 483 rexmt = TCP_REXMTVAL(tp) * tcp_syn_backoff[tp->t_rxtshift]; 484 else 485 rexmt = TCP_REXMTVAL(tp) * tcp_backoff[tp->t_rxtshift]; 486 TCPT_RANGESET(tp->t_rxtcur, rexmt, 487 tp->t_rttmin, TCPTV_REXMTMAX); 488 /* 489 * Disable rfc1323 if we havn't got any response to 490 * our third SYN to work-around some broken terminal servers 491 * (most of which have hopefully been retired) that have bad VJ 492 * header compression code which trashes TCP segments containing 493 * unknown-to-them TCP options. 494 */ 495 if ((tp->t_state == TCPS_SYN_SENT) && (tp->t_rxtshift == 3)) 496 tp->t_flags &= ~(TF_REQ_SCALE|TF_REQ_TSTMP); 497 /* 498 * If we backed off this far, our srtt estimate is probably bogus. 499 * Clobber it so we'll take the next rtt measurement as our srtt; 500 * move the current srtt into rttvar to keep the current 501 * retransmit times until then. 502 */ 503 if (tp->t_rxtshift > TCP_MAXRXTSHIFT / 4) { 504 #ifdef INET6 505 if ((tp->t_inpcb->inp_vflag & INP_IPV6) != 0) 506 in6_losing(tp->t_inpcb); 507 else 508 #endif 509 tp->t_rttvar += (tp->t_srtt >> TCP_RTT_SHIFT); 510 tp->t_srtt = 0; 511 } 512 tp->snd_nxt = tp->snd_una; 513 tp->snd_recover = tp->snd_max; 514 /* 515 * Force a segment to be sent. 516 */ 517 tp->t_flags |= TF_ACKNOW; 518 /* 519 * If timing a segment in this window, stop the timer. 520 */ 521 tp->t_rtttime = 0; 522 /* 523 * Close the congestion window down to one segment 524 * (we'll open it by one segment for each ack we get). 525 * Since we probably have a window's worth of unacked 526 * data accumulated, this "slow start" keeps us from 527 * dumping all that data as back-to-back packets (which 528 * might overwhelm an intermediate gateway). 529 * 530 * There are two phases to the opening: Initially we 531 * open by one mss on each ack. This makes the window 532 * size increase exponentially with time. If the 533 * window is larger than the path can handle, this 534 * exponential growth results in dropped packet(s) 535 * almost immediately. To get more time between 536 * drops but still "push" the network to take advantage 537 * of improving conditions, we switch from exponential 538 * to linear window opening at some threshhold size. 539 * For a threshhold, we use half the current window 540 * size, truncated to a multiple of the mss. 541 * 542 * (the minimum cwnd that will give us exponential 543 * growth is 2 mss. We don't allow the threshhold 544 * to go below this.) 545 */ 546 { 547 u_int win = min(tp->snd_wnd, tp->snd_cwnd) / 2 / tp->t_maxseg; 548 if (win < 2) 549 win = 2; 550 tp->snd_cwnd = tp->t_maxseg; 551 tp->snd_ssthresh = win * tp->t_maxseg; 552 tp->t_dupacks = 0; 553 } 554 EXIT_FASTRECOVERY(tp); 555 (void) tcp_output(tp); 556 557 out: 558 #ifdef TCPDEBUG 559 if (tp != NULL && (tp->t_inpcb->inp_socket->so_options & SO_DEBUG)) 560 tcp_trace(TA_USER, ostate, tp, (void *)0, (struct tcphdr *)0, 561 PRU_SLOWTIMO); 562 #endif 563 if (tp != NULL) 564 INP_WUNLOCK(inp); 565 if (headlocked) 566 INP_INFO_WUNLOCK(&V_tcbinfo); 567 } 568 569 void 570 tcp_timer_activate(struct tcpcb *tp, int timer_type, u_int delta) 571 { 572 struct callout *t_callout; 573 void *f_callout; 574 575 switch (timer_type) { 576 case TT_DELACK: 577 t_callout = &tp->t_timers->tt_delack; 578 f_callout = tcp_timer_delack; 579 break; 580 case TT_REXMT: 581 t_callout = &tp->t_timers->tt_rexmt; 582 f_callout = tcp_timer_rexmt; 583 break; 584 case TT_PERSIST: 585 t_callout = &tp->t_timers->tt_persist; 586 f_callout = tcp_timer_persist; 587 break; 588 case TT_KEEP: 589 t_callout = &tp->t_timers->tt_keep; 590 f_callout = tcp_timer_keep; 591 break; 592 case TT_2MSL: 593 t_callout = &tp->t_timers->tt_2msl; 594 f_callout = tcp_timer_2msl; 595 break; 596 default: 597 panic("bad timer_type"); 598 } 599 if (delta == 0) { 600 callout_stop(t_callout); 601 } else { 602 callout_reset(t_callout, delta, f_callout, tp); 603 } 604 } 605 606 int 607 tcp_timer_active(struct tcpcb *tp, int timer_type) 608 { 609 struct callout *t_callout; 610 611 switch (timer_type) { 612 case TT_DELACK: 613 t_callout = &tp->t_timers->tt_delack; 614 break; 615 case TT_REXMT: 616 t_callout = &tp->t_timers->tt_rexmt; 617 break; 618 case TT_PERSIST: 619 t_callout = &tp->t_timers->tt_persist; 620 break; 621 case TT_KEEP: 622 t_callout = &tp->t_timers->tt_keep; 623 break; 624 case TT_2MSL: 625 t_callout = &tp->t_timers->tt_2msl; 626 break; 627 default: 628 panic("bad timer_type"); 629 } 630 return callout_active(t_callout); 631 } 632