2 * Copyright (c) 2003, 2004 Jeffrey M. Hsu. All rights reserved.
3 * Copyright (c) 2003, 2004 The DragonFly Project. All rights reserved.
5 * This code is derived from software contributed to The DragonFly Project
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
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15 * documentation and/or other materials provided with the distribution.
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17 * contributors may be used to endorse or promote products derived
18 * from this software without specific, prior written permission.
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39 * modification, are permitted provided that the following conditions
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62 * @(#)tcp_timer.c 8.2 (Berkeley) 5/24/95
63 * $FreeBSD: src/sys/netinet/tcp_timer.c,v 1.34.2.14 2003/02/03 02:33:41 hsu Exp $
64 * $DragonFly: src/sys/netinet/tcp_timer.c,v 1.17 2008/03/30 20:39:01 dillon Exp $
67 #include "opt_compat.h"
68 #include "opt_inet6.h"
69 #include "opt_tcpdebug.h"
71 #include <sys/param.h>
72 #include <sys/systm.h>
73 #include <sys/kernel.h>
75 #include <sys/sysctl.h>
76 #include <sys/socket.h>
77 #include <sys/socketvar.h>
78 #include <sys/protosw.h>
79 #include <sys/thread.h>
80 #include <sys/globaldata.h>
81 #include <sys/thread2.h>
82 #include <sys/msgport2.h>
84 #include <machine/cpu.h> /* before tcp_seq.h, for tcp_random18() */
86 #include <net/route.h>
87 #include <net/netmsg2.h>
89 #include <netinet/in.h>
90 #include <netinet/in_systm.h>
91 #include <netinet/in_pcb.h>
93 #include <netinet6/in6_pcb.h>
95 #include <netinet/ip_var.h>
96 #include <netinet/tcp.h>
97 #include <netinet/tcp_fsm.h>
98 #include <netinet/tcp_seq.h>
99 #include <netinet/tcp_timer.h>
100 #include <netinet/tcp_timer2.h>
101 #include <netinet/tcp_var.h>
102 #include <netinet/tcpip.h>
104 #include <netinet/tcp_debug.h>
107 #define TCP_TIMER_REXMT 0x01
108 #define TCP_TIMER_PERSIST 0x02
109 #define TCP_TIMER_KEEP 0x04
110 #define TCP_TIMER_2MSL 0x08
111 #define TCP_TIMER_DELACK 0x10
113 static struct tcpcb
*tcp_timer_rexmt_handler(struct tcpcb
*);
114 static struct tcpcb
*tcp_timer_persist_handler(struct tcpcb
*);
115 static struct tcpcb
*tcp_timer_keep_handler(struct tcpcb
*);
116 static struct tcpcb
*tcp_timer_2msl_handler(struct tcpcb
*);
117 static struct tcpcb
*tcp_timer_delack_handler(struct tcpcb
*);
119 static const struct tcp_timer
{
121 struct tcpcb
*(*tt_handler
)(struct tcpcb
*);
122 } tcp_timer_handlers
[] = {
123 { TCP_TIMER_DELACK
, tcp_timer_delack_handler
},
124 { TCP_TIMER_REXMT
, tcp_timer_rexmt_handler
},
125 { TCP_TIMER_PERSIST
, tcp_timer_persist_handler
},
126 { TCP_TIMER_KEEP
, tcp_timer_keep_handler
},
127 { TCP_TIMER_2MSL
, tcp_timer_2msl_handler
},
132 sysctl_msec_to_ticks(SYSCTL_HANDLER_ARGS
)
136 tt
= *(int *)oidp
->oid_arg1
;
137 s
= (int)((int64_t)tt
* 1000 / hz
);
139 error
= sysctl_handle_int(oidp
, &s
, 0, req
);
140 if (error
|| !req
->newptr
)
143 tt
= (int)((int64_t)s
* hz
/ 1000);
147 *(int *)oidp
->oid_arg1
= tt
;
152 SYSCTL_PROC(_net_inet_tcp
, TCPCTL_KEEPINIT
, keepinit
, CTLTYPE_INT
|CTLFLAG_RW
,
153 &tcp_keepinit
, 0, sysctl_msec_to_ticks
, "I", "Time to establish TCP connection");
156 SYSCTL_PROC(_net_inet_tcp
, TCPCTL_KEEPIDLE
, keepidle
, CTLTYPE_INT
|CTLFLAG_RW
,
157 &tcp_keepidle
, 0, sysctl_msec_to_ticks
, "I", "Time before TCP keepalive probes begin");
160 SYSCTL_PROC(_net_inet_tcp
, TCPCTL_KEEPINTVL
, keepintvl
, CTLTYPE_INT
|CTLFLAG_RW
,
161 &tcp_keepintvl
, 0, sysctl_msec_to_ticks
, "I", "Time between TCP keepalive probes");
164 SYSCTL_PROC(_net_inet_tcp
, TCPCTL_DELACKTIME
, delacktime
,
165 CTLTYPE_INT
|CTLFLAG_RW
, &tcp_delacktime
, 0, sysctl_msec_to_ticks
, "I",
166 "Time before a delayed ACK is sent");
169 SYSCTL_PROC(_net_inet_tcp
, OID_AUTO
, msl
, CTLTYPE_INT
|CTLFLAG_RW
,
170 &tcp_msl
, 0, sysctl_msec_to_ticks
, "I", "Maximum segment lifetime");
173 SYSCTL_PROC(_net_inet_tcp
, OID_AUTO
, rexmit_min
, CTLTYPE_INT
|CTLFLAG_RW
,
174 &tcp_rexmit_min
, 0, sysctl_msec_to_ticks
, "I", "Minimum Retransmission Timeout");
177 SYSCTL_PROC(_net_inet_tcp
, OID_AUTO
, rexmit_slop
, CTLTYPE_INT
|CTLFLAG_RW
,
178 &tcp_rexmit_slop
, 0, sysctl_msec_to_ticks
, "I",
179 "Retransmission Timer Slop");
181 static int always_keepalive
= 1;
182 SYSCTL_INT(_net_inet_tcp
, OID_AUTO
, always_keepalive
, CTLFLAG_RW
,
183 &always_keepalive
, 0, "Assume SO_KEEPALIVE on all TCP connections");
185 /* max idle probes */
186 int tcp_keepcnt
= TCPTV_KEEPCNT
;
187 SYSCTL_INT(_net_inet_tcp
, OID_AUTO
, keepcnt
, CTLFLAG_RW
,
188 &tcp_keepcnt
, 0, "Maximum number of keepalive probes to be sent");
190 static int tcp_do_eifel_response
= 1;
191 SYSCTL_INT(_net_inet_tcp
, OID_AUTO
, eifel_response
, CTLFLAG_RW
,
192 &tcp_do_eifel_response
, 0, "Eifel response algorithm (RFC 4015)");
194 int tcp_eifel_rtoinc
= 2;
195 SYSCTL_PROC(_net_inet_tcp
, OID_AUTO
, eifel_rtoinc
, CTLTYPE_INT
|CTLFLAG_RW
,
196 &tcp_eifel_rtoinc
, 0, sysctl_msec_to_ticks
, "I",
197 "Eifel response RTO increment");
199 /* max idle time in persist */
200 int tcp_maxpersistidle
;
203 * Cancel all timers for TCP tp.
206 tcp_canceltimers(struct tcpcb
*tp
)
208 tcp_callout_stop(tp
, tp
->tt_2msl
);
209 tcp_callout_stop(tp
, tp
->tt_persist
);
210 tcp_callout_stop(tp
, tp
->tt_keep
);
211 tcp_callout_stop(tp
, tp
->tt_rexmt
);
215 * Caller should be in critical section
218 tcp_send_timermsg(struct tcpcb
*tp
, uint32_t task
)
220 struct netmsg_tcp_timer
*tmsg
= tp
->tt_msg
;
222 KKASSERT(tmsg
!= NULL
&& tmsg
->tt_cpuid
== mycpuid
&&
223 tmsg
->tt_tcb
!= NULL
);
225 tmsg
->tt_tasks
|= task
;
226 if (tmsg
->tt_msg
.lmsg
.ms_flags
& MSGF_DONE
)
227 lwkt_sendmsg_oncpu(tmsg
->tt_msgport
, &tmsg
->tt_msg
.lmsg
);
230 int tcp_syn_backoff
[TCP_MAXRXTSHIFT
+ 1] =
231 { 1, 1, 1, 1, 1, 2, 4, 8, 16, 32, 64, 64, 64 };
233 int tcp_syn_backoff_low
[TCP_MAXRXTSHIFT
+ 1] =
234 { 1, 1, 2, 4, 8, 8, 16, 16, 32, 64, 64, 64, 64 };
236 int tcp_backoff
[TCP_MAXRXTSHIFT
+ 1] =
237 { 1, 2, 4, 8, 16, 32, 64, 64, 64, 64, 64, 64, 64 };
239 static int tcp_totbackoff
= 511; /* sum of tcp_backoff[] */
241 /* Caller should be in critical section */
242 static struct tcpcb
*
243 tcp_timer_delack_handler(struct tcpcb
*tp
)
245 tp
->t_flags
|= TF_ACKNOW
;
246 tcpstat
.tcps_delack
++;
252 * TCP timer processing.
255 tcp_timer_delack(void *xtp
)
257 struct tcpcb
*tp
= xtp
;
258 struct callout
*co
= &tp
->tt_delack
->tc_callout
;
261 if (callout_pending(co
) || !callout_active(co
)) {
265 callout_deactivate(co
);
266 tcp_send_timermsg(tp
, TCP_TIMER_DELACK
);
270 /* Caller should be in critical section */
271 static struct tcpcb
*
272 tcp_timer_2msl_handler(struct tcpcb
*tp
)
279 ostate
= tp
->t_state
;
282 * 2 MSL timeout in shutdown went off. If we're closed but
283 * still waiting for peer to close and connection has been idle
284 * too long, or if 2MSL time is up from TIME_WAIT, delete connection
285 * control block. Otherwise, check again in a bit.
287 if (tp
->t_state
!= TCPS_TIME_WAIT
&&
288 (ticks
- tp
->t_rcvtime
) <= tp
->t_maxidle
) {
289 tcp_callout_reset(tp
, tp
->tt_2msl
, tp
->t_keepintvl
,
296 if (tp
&& (tp
->t_inpcb
->inp_socket
->so_options
& SO_DEBUG
))
297 tcp_trace(TA_USER
, ostate
, tp
, NULL
, NULL
, PRU_SLOWTIMO
);
303 tcp_timer_2msl(void *xtp
)
305 struct tcpcb
*tp
= xtp
;
306 struct callout
*co
= &tp
->tt_2msl
->tc_callout
;
309 if (callout_pending(co
) || !callout_active(co
)) {
313 callout_deactivate(co
);
314 tcp_send_timermsg(tp
, TCP_TIMER_2MSL
);
318 /* Caller should be in critical section */
319 static struct tcpcb
*
320 tcp_timer_keep_handler(struct tcpcb
*tp
)
322 struct tcptemp
*t_template
;
324 int ostate
= tp
->t_state
;
328 * Keep-alive timer went off; send something
329 * or drop connection if idle for too long.
331 tcpstat
.tcps_keeptimeo
++;
332 if (tp
->t_state
< TCPS_ESTABLISHED
)
334 if ((always_keepalive
|| (tp
->t_flags
& TF_KEEPALIVE
) ||
335 (tp
->t_inpcb
->inp_socket
->so_options
& SO_KEEPALIVE
)) &&
336 tp
->t_state
<= TCPS_CLOSING
) {
337 if ((ticks
- tp
->t_rcvtime
) >= tp
->t_keepidle
+ tp
->t_maxidle
)
340 * Send a packet designed to force a response
341 * if the peer is up and reachable:
342 * either an ACK if the connection is still alive,
343 * or an RST if the peer has closed the connection
344 * due to timeout or reboot.
345 * Using sequence number tp->snd_una-1
346 * causes the transmitted zero-length segment
347 * to lie outside the receive window;
348 * by the protocol spec, this requires the
349 * correspondent TCP to respond.
351 tcpstat
.tcps_keepprobe
++;
352 t_template
= tcp_maketemplate(tp
);
354 tcp_respond(tp
, t_template
->tt_ipgen
,
355 &t_template
->tt_t
, NULL
,
356 tp
->rcv_nxt
, tp
->snd_una
- 1, 0);
357 tcp_freetemplate(t_template
);
359 tcp_callout_reset(tp
, tp
->tt_keep
, tp
->t_keepintvl
,
362 tcp_callout_reset(tp
, tp
->tt_keep
, tp
->t_keepidle
,
367 if (tp
->t_inpcb
->inp_socket
->so_options
& SO_DEBUG
)
368 tcp_trace(TA_USER
, ostate
, tp
, NULL
, NULL
, PRU_SLOWTIMO
);
373 tcpstat
.tcps_keepdrops
++;
374 tp
= tcp_drop(tp
, ETIMEDOUT
);
377 if (tp
&& (tp
->t_inpcb
->inp_socket
->so_options
& SO_DEBUG
))
378 tcp_trace(TA_USER
, ostate
, tp
, NULL
, NULL
, PRU_SLOWTIMO
);
384 tcp_timer_keep(void *xtp
)
386 struct tcpcb
*tp
= xtp
;
387 struct callout
*co
= &tp
->tt_keep
->tc_callout
;
390 if (callout_pending(co
) || !callout_active(co
)) {
394 callout_deactivate(co
);
395 tcp_send_timermsg(tp
, TCP_TIMER_KEEP
);
399 /* Caller should be in critical section */
400 static struct tcpcb
*
401 tcp_timer_persist_handler(struct tcpcb
*tp
)
408 ostate
= tp
->t_state
;
411 * Persistance timer into zero window.
412 * Force a byte to be output, if possible.
414 tcpstat
.tcps_persisttimeo
++;
416 * Hack: if the peer is dead/unreachable, we do not
417 * time out if the window is closed. After a full
418 * backoff, drop the connection if the idle time
419 * (no responses to probes) reaches the maximum
420 * backoff that we would use if retransmitting.
422 if (tp
->t_rxtshift
== TCP_MAXRXTSHIFT
&&
423 ((ticks
- tp
->t_rcvtime
) >= tcp_maxpersistidle
||
424 (ticks
- tp
->t_rcvtime
) >= TCP_REXMTVAL(tp
) * tcp_totbackoff
)) {
425 tcpstat
.tcps_persistdrop
++;
426 tp
= tcp_drop(tp
, ETIMEDOUT
);
430 tp
->t_flags
|= TF_FORCE
;
432 tp
->t_flags
&= ~TF_FORCE
;
436 if (tp
&& tp
->t_inpcb
->inp_socket
->so_options
& SO_DEBUG
)
437 tcp_trace(TA_USER
, ostate
, tp
, NULL
, NULL
, PRU_SLOWTIMO
);
443 tcp_timer_persist(void *xtp
)
445 struct tcpcb
*tp
= xtp
;
446 struct callout
*co
= &tp
->tt_persist
->tc_callout
;
449 if (callout_pending(co
) || !callout_active(co
)){
453 callout_deactivate(co
);
454 tcp_send_timermsg(tp
, TCP_TIMER_PERSIST
);
459 tcp_save_congestion_state(struct tcpcb
*tp
)
462 * Record connection's current states so that they could be
463 * recovered, if this turns out to be a spurious retransmit.
465 tp
->snd_cwnd_prev
= tp
->snd_cwnd
;
466 tp
->snd_wacked_prev
= tp
->snd_wacked
;
467 tp
->snd_ssthresh_prev
= tp
->snd_ssthresh
;
468 tp
->snd_recover_prev
= tp
->snd_recover
;
471 * State for Eifel response after spurious timeout retransmit
472 * is detected. We save the current value of snd_max even if
473 * we are called from fast retransmit code, so if RTO needs
474 * rebase, it will be rebased using the RTT of segment that
475 * is not sent during possible congestion.
477 tp
->snd_max_prev
= tp
->snd_max
;
479 if (IN_FASTRECOVERY(tp
))
480 tp
->rxt_flags
|= TRXT_F_WASFRECOVERY
;
482 tp
->rxt_flags
&= ~TRXT_F_WASFRECOVERY
;
483 if (tp
->t_flags
& TF_RCVD_TSTMP
) {
484 /* States for Eifel detection */
485 tp
->t_rexmtTS
= ticks
;
486 tp
->rxt_flags
|= TRXT_F_FIRSTACCACK
;
489 tcp_sack_save_scoreboard(&tp
->scb
);
494 tcp_revert_congestion_state(struct tcpcb
*tp
)
496 tp
->snd_cwnd
= tp
->snd_cwnd_prev
;
497 tp
->snd_wacked
= tp
->snd_wacked_prev
;
498 tp
->snd_ssthresh
= tp
->snd_ssthresh_prev
;
499 tp
->snd_recover
= tp
->snd_recover_prev
;
500 if (tp
->rxt_flags
& TRXT_F_WASFRECOVERY
)
501 ENTER_FASTRECOVERY(tp
);
502 if (tp
->rxt_flags
& TRXT_F_FASTREXMT
) {
503 ++tcpstat
.tcps_sndfastrexmitbad
;
504 if (tp
->rxt_flags
& TRXT_F_EARLYREXMT
)
505 ++tcpstat
.tcps_sndearlyrexmitbad
;
507 ++tcpstat
.tcps_sndrtobad
;
508 tp
->snd_last
= ticks
;
509 if (tcp_do_eifel_response
)
510 tp
->rxt_flags
|= TRXT_F_REBASERTO
;
514 tp
->snd_nxt
= tp
->snd_max
;
516 tcp_sack_revert_scoreboard(&tp
->scb
, tp
->snd_una
);
520 /* Caller should be in critical section */
521 static struct tcpcb
*
522 tcp_timer_rexmt_handler(struct tcpcb
*tp
)
530 ostate
= tp
->t_state
;
533 * Retransmission timer went off. Message has not
534 * been acked within retransmit interval. Back off
535 * to a longer retransmit interval and retransmit one segment.
537 if (++tp
->t_rxtshift
> TCP_MAXRXTSHIFT
) {
538 tp
->t_rxtshift
= TCP_MAXRXTSHIFT
;
539 tcpstat
.tcps_timeoutdrop
++;
540 tp
= tcp_drop(tp
, tp
->t_softerror
?
541 tp
->t_softerror
: ETIMEDOUT
);
544 if (tp
->t_rxtshift
== 1) {
550 * State for "RTT based spurious timeout retransmit detection"
552 * RTT based spurious timeout retransmit detection:
553 * A retransmit is considered spurious if an ACK for this
554 * segment is received within RTT/2 interval; the assumption
555 * here is that the ACK was already in flight. See
556 * "On Estimating End-to-End Network Path Properties" by
557 * Allman and Paxson for more details.
559 tp
->t_badrxtwin
= ticks
+ (tp
->t_srtt
>> (TCP_RTT_SHIFT
+ 1));
562 * States for Eifel response after spurious timeout retransmit
565 tp
->t_rxtcur_prev
= tp
->t_rxtcur
;
566 tp
->t_srtt_prev
= tp
->t_srtt
+
567 (tcp_eifel_rtoinc
<< TCP_RTT_SHIFT
);
568 tp
->t_rttvar_prev
= tp
->t_rttvar
;
570 tcp_save_congestion_state(tp
);
571 tp
->rxt_flags
&= ~(TRXT_F_FASTREXMT
| TRXT_F_EARLYREXMT
|
574 if (tp
->t_state
== TCPS_SYN_SENT
|| tp
->t_state
== TCPS_SYN_RECEIVED
) {
576 * Record the time that we spent in SYN or SYN|ACK
579 * Needed by RFC3390 and RFC6298.
581 tp
->t_rxtsyn
+= tp
->t_rxtcur
;
583 /* Throw away SACK blocks on a RTO, as specified by RFC2018. */
584 tcp_sack_discard(tp
);
585 tcpstat
.tcps_rexmttimeo
++;
586 if (tp
->t_state
== TCPS_SYN_SENT
) {
587 if (tcp_low_rtobase
) {
588 rexmt
= TCP_REXMTVAL(tp
) *
589 tcp_syn_backoff_low
[tp
->t_rxtshift
];
591 rexmt
= TCP_REXMTVAL(tp
) *
592 tcp_syn_backoff
[tp
->t_rxtshift
];
595 rexmt
= TCP_REXMTVAL(tp
) * tcp_backoff
[tp
->t_rxtshift
];
597 TCPT_RANGESET(tp
->t_rxtcur
, rexmt
,
598 tp
->t_rttmin
, TCPTV_REXMTMAX
);
600 * If losing, let the lower level know and try for
601 * a better route. Also, if we backed off this far,
602 * our srtt estimate is probably bogus. Clobber it
603 * so we'll take the next rtt measurement as our srtt;
604 * move the current srtt into rttvar to keep the current
605 * retransmit times until then.
607 if (tp
->t_rxtshift
> TCP_MAXRXTSHIFT
/ 4) {
609 if (INP_ISIPV6(tp
->t_inpcb
))
610 in6_losing(tp
->t_inpcb
);
613 in_losing(tp
->t_inpcb
);
614 tp
->t_rttvar
+= (tp
->t_srtt
>> TCP_RTT_SHIFT
);
617 tp
->snd_nxt
= tp
->snd_una
;
618 tp
->snd_recover
= tp
->snd_max
;
620 * Force a segment to be sent.
622 tp
->t_flags
|= TF_ACKNOW
;
624 * If timing a segment in this window, stop the timer.
628 * Close the congestion window down to one segment
629 * (we'll open it by one segment for each ack we get).
630 * Since we probably have a window's worth of unacked
631 * data accumulated, this "slow start" keeps us from
632 * dumping all that data as back-to-back packets (which
633 * might overwhelm an intermediate gateway).
635 * There are two phases to the opening: Initially we
636 * open by one mss on each ack. This makes the window
637 * size increase exponentially with time. If the
638 * window is larger than the path can handle, this
639 * exponential growth results in dropped packet(s)
640 * almost immediately. To get more time between
641 * drops but still "push" the network to take advantage
642 * of improving conditions, we switch from exponential
643 * to linear window opening at some threshhold size.
644 * For a threshhold, we use half the current window
645 * size, truncated to a multiple of the mss.
647 * (the minimum cwnd that will give us exponential
648 * growth is 2 mss. We don't allow the threshhold
652 u_int win
= min(tp
->snd_wnd
, tp
->snd_cwnd
) / 2 / tp
->t_maxseg
;
656 tp
->snd_cwnd
= tp
->t_maxseg
;
658 tp
->snd_ssthresh
= win
* tp
->t_maxseg
;
661 EXIT_FASTRECOVERY(tp
);
666 if (tp
&& (tp
->t_inpcb
->inp_socket
->so_options
& SO_DEBUG
))
667 tcp_trace(TA_USER
, ostate
, tp
, NULL
, NULL
, PRU_SLOWTIMO
);
673 tcp_timer_rexmt(void *xtp
)
675 struct tcpcb
*tp
= xtp
;
676 struct callout
*co
= &tp
->tt_rexmt
->tc_callout
;
679 if (callout_pending(co
) || !callout_active(co
)) {
683 callout_deactivate(co
);
684 tcp_send_timermsg(tp
, TCP_TIMER_REXMT
);
689 tcp_timer_handler(netmsg_t msg
)
691 struct netmsg_tcp_timer
*tmsg
= (struct netmsg_tcp_timer
*)msg
;
692 const struct tcp_timer
*tt
;
697 KKASSERT(tmsg
->tt_cpuid
== mycpuid
&& tmsg
->tt_tcb
!= NULL
);
700 /* Save pending tasks and reset the tasks in message */
701 tmsg
->tt_running_tasks
= tmsg
->tt_tasks
;
702 tmsg
->tt_prev_tasks
= tmsg
->tt_tasks
;
706 lwkt_replymsg(&tmsg
->tt_msg
.lmsg
, 0);
708 if (tmsg
->tt_running_tasks
== 0) {
710 * All of the timers are cancelled when the message
711 * is pending; bail out.
717 for (tt
= tcp_timer_handlers
; tt
->tt_handler
!= NULL
; ++tt
) {
718 if ((tmsg
->tt_running_tasks
& tt
->tt_task
) == 0)
721 tmsg
->tt_running_tasks
&= ~tt
->tt_task
;
722 tp
= tt
->tt_handler(tp
);
726 if (tmsg
->tt_running_tasks
== 0) /* nothing left to do */
734 tcp_create_timermsg(struct tcpcb
*tp
, struct lwkt_port
*msgport
)
736 struct netmsg_tcp_timer
*tmsg
= tp
->tt_msg
;
738 netmsg_init(&tmsg
->tt_msg
, NULL
, &netisr_adone_rport
,
739 MSGF_DROPABLE
| MSGF_PRIORITY
, tcp_timer_handler
);
740 tmsg
->tt_cpuid
= mycpuid
;
741 tmsg
->tt_msgport
= msgport
;
747 tcp_destroy_timermsg(struct tcpcb
*tp
)
749 struct netmsg_tcp_timer
*tmsg
= tp
->tt_msg
;
751 if (tmsg
== NULL
|| /* listen socket */
752 tmsg
->tt_tcb
== NULL
) /* only tcp_attach() is called */
755 KKASSERT(tmsg
->tt_cpuid
== mycpuid
);
758 * This message is still pending to be processed;
759 * drop it. Optimized.
762 if ((tmsg
->tt_msg
.lmsg
.ms_flags
& MSGF_DONE
) == 0) {
763 lwkt_dropmsg(&tmsg
->tt_msg
.lmsg
);
769 tcp_callout_init(struct tcp_callout
*tc
, uint32_t task
)
771 callout_init_mp(&tc
->tc_callout
);
776 tcp_inittimers(struct tcpcb
*tp
)
778 tcp_callout_init(tp
->tt_rexmt
, TCP_TIMER_REXMT
);
779 tcp_callout_init(tp
->tt_persist
, TCP_TIMER_PERSIST
);
780 tcp_callout_init(tp
->tt_keep
, TCP_TIMER_KEEP
);
781 tcp_callout_init(tp
->tt_2msl
, TCP_TIMER_2MSL
);
782 tcp_callout_init(tp
->tt_delack
, TCP_TIMER_DELACK
);