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