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Back out tcp_timer.c:1.93 and associated changes that reimplemented the many

Browse Source 
TCP timers as a single timer, but retain the API changes necessary to
reintroduce this change.  This will back out the source of at least two
reported problems: lock leaks in certain timer edge cases, and TCP timers
continuing to fire after a connection has closed (a bug previously fixed and
then reintroduced with the timer rewrite).

In a follow-up commit, some minor restylings and comment changes performed
after the TCP timer rewrite will be reapplied, and a further change to allow
the TCP timer rewrite to be added back without disturbing the ABI.  The new
design is believed to be a good thing, but the outstanding issues are
leading to significant stability/correctness problems that are holding
up 7.0.

This patch was generated by silby, but is being committed by proxy due to
poor network connectivity for silby this week.

Approved by:	re (kensmith)
Submitted by:	silby
Tested by:	rwatson, kris
Problems reported by:	peter, kris, others
This commit is contained in:
Robert Watson 2007-09-07 09:19:22 +00:00
parent 2a2391c23c
commit 85d9437250
Notes: svn2git 2020-12-20 02:59:44 +00:00 
svn path=/head/; revision=172074
5 changed files with 273 additions and 341 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

24
sys/netinet/tcp_subr.c
View File

@ -214,7 +214,8 @@ static void tcp_isn_tick(void *);
*/
struct tcpcb_mem {
struct tcpcb tcb;
struct tcp_timer tt;
struct callout tcpcb_mem_rexmt, tcpcb_mem_persist, tcpcb_mem_keep;
struct callout tcpcb_mem_2msl, tcpcb_mem_delack;
};
static uma_zone_t tcpcb_zone;
@ -589,7 +590,6 @@ tcp_newtcpcb(struct inpcb *inp)
if (tm == NULL)
return (NULL);
tp = &tm->tcb;
tp->t_timers = &tm->tt;
/* LIST_INIT(&tp->t_segq); */ /* XXX covered by M_ZERO */
tp->t_maxseg = tp->t_maxopd =
#ifdef INET6
@ -598,8 +598,11 @@ tcp_newtcpcb(struct inpcb *inp)
tcp_mssdflt;
/* Set up our timeouts. */
callout_init_mtx(&tp->t_timers->tt_timer, &inp->inp_mtx,
CALLOUT_RETURNUNLOCKED);
callout_init(tp->tt_rexmt = &tm->tcpcb_mem_rexmt, CALLOUT_MPSAFE);
callout_init(tp->tt_persist = &tm->tcpcb_mem_persist, CALLOUT_MPSAFE);
callout_init(tp->tt_keep = &tm->tcpcb_mem_keep, CALLOUT_MPSAFE);
callout_init(tp->tt_2msl = &tm->tcpcb_mem_2msl, CALLOUT_MPSAFE);
callout_init(tp->tt_delack = &tm->tcpcb_mem_delack, CALLOUT_MPSAFE);
if (tcp_do_rfc1323)
tp->t_flags = (TF_REQ_SCALE|TF_REQ_TSTMP);
@ -671,15 +674,12 @@ tcp_discardcb(struct tcpcb *tp)
/*
* Make sure that all of our timers are stopped before we
* delete the PCB.
*
* XXX: callout_stop() may race and a callout may already
* try to obtain the INP_LOCK. Only callout_drain() would
* stop this but it would cause a LOR thus we can't use it.
* The tcp_timer() function contains a lot of checks to
* handle this case rather gracefully.
*/
tp->t_timers->tt_active = 0;
callout_stop(&tp->t_timers->tt_timer);
callout_stop(tp->tt_rexmt);
callout_stop(tp->tt_persist);
callout_stop(tp->tt_keep);
callout_stop(tp->tt_2msl);
callout_stop(tp->tt_delack);
/*
* If we got enough samples through the srtt filter,

558
sys/netinet/tcp_timer.c
View File

@ -35,9 +35,7 @@
#include <sys/param.h>
#include <sys/kernel.h>
#include <sys/ktr.h>
#include <sys/lock.h>
#include <sys/limits.h>
#include <sys/mbuf.h>
#include <sys/mutex.h>
#include <sys/protosw.h>
@ -115,20 +113,13 @@ int tcp_maxpersistidle;
/* max idle time in persist */
int tcp_maxidle;
static void tcp_timer(void *);
static int tcp_timer_delack(struct tcpcb *, struct inpcb *);
static int tcp_timer_2msl(struct tcpcb *, struct inpcb *);
static int tcp_timer_keep(struct tcpcb *, struct inpcb *);
static int tcp_timer_persist(struct tcpcb *, struct inpcb *);
static int tcp_timer_rexmt(struct tcpcb *, struct inpcb *);
/*
* Tcp protocol timeout routine called every 500 ms.
* Updates timestamps used for TCP
* causes finite state machine actions if timers expire.
*/
void
tcp_slowtimo(void)
tcp_slowtimo()
{
tcp_maxidle = tcp_keepcnt * tcp_keepintvl;
@ -149,300 +140,81 @@ static int tcp_timer_race;
SYSCTL_INT(_net_inet_tcp, OID_AUTO, timer_race, CTLFLAG_RD, &tcp_timer_race,
0, "Count of t_inpcb races on tcp_discardcb");
void
tcp_timer_activate(struct tcpcb *tp, int timer_type, u_int delta)
{
struct inpcb *inp = tp->t_inpcb;
struct tcp_timer *tt = tp->t_timers;
int tick = ticks; /* Stable time base. */
int next = delta ? tick + delta : 0;
INP_LOCK_ASSERT(inp);
CTR6(KTR_NET, "%p %s inp %p active %x delta %i nextc %i",
tp, __func__, inp, tt->tt_active, delta, tt->tt_nextc);
/* Set new value for timer. */
switch(timer_type) {
case TT_DELACK:
CTR4(KTR_NET, "%p %s TT_DELACK old %i new %i",
tp, __func__, tt->tt_delack, next);
tt->tt_delack = next;
break;
case TT_REXMT:
CTR4(KTR_NET, "%p %s TT_REXMT old %i new %i",
tp, __func__, tt->tt_rexmt, next);
tt->tt_rexmt = next;
break;
case TT_PERSIST:
CTR4(KTR_NET, "%p %s TT_PERSIST old %i new %i",
tp, __func__, tt->tt_persist, next);
tt->tt_persist = next;
break;
case TT_KEEP:
CTR4(KTR_NET, "%p %s TT_KEEP old %i new %i",
tp, __func__, tt->tt_keep, next);
tt->tt_keep = next;
break;
case TT_2MSL:
CTR4(KTR_NET, "%p %s TT_2MSL old %i new %i",
tp, __func__, tt->tt_2msl, next);
tt->tt_2msl = next;
break;
case 0: /* Dummy for timer rescan. */
CTR3(KTR_NET, "%p %s timer rescan new %i", tp, __func__, next);
break;
}
/* If some other timer is active and is schedules sooner just return. */
if (tt->tt_active != timer_type && tt->tt_nextc < next &&
callout_active(&tt->tt_timer))
return;
/* Select next timer to schedule. */
tt->tt_nextc = INT_MAX;
tt->tt_active = 0;
if (tt->tt_delack && tt->tt_delack < tt->tt_nextc) {
tt->tt_nextc = tt->tt_delack;
tt->tt_active = TT_DELACK;
}
if (tt->tt_rexmt && tt->tt_rexmt < tt->tt_nextc) {
tt->tt_nextc = tt->tt_rexmt;
tt->tt_active = TT_REXMT;
}
if (tt->tt_persist && tt->tt_persist < tt->tt_nextc) {
tt->tt_nextc = tt->tt_persist;
tt->tt_active = TT_PERSIST;
}
if (tt->tt_keep && tt->tt_keep < tt->tt_nextc) {
tt->tt_nextc = tt->tt_keep;
tt->tt_active = TT_KEEP;
}
if (tt->tt_2msl && tt->tt_2msl < tt->tt_nextc) {
tt->tt_nextc = tt->tt_2msl;
tt->tt_active = TT_2MSL;
}
/* Rearm callout with new timer if we found one. */
if (tt->tt_active) {
CTR4(KTR_NET, "%p %s callout_reset active %x nextc in %i",
tp, __func__, tt->tt_active, tt->tt_nextc - tick);
callout_reset(&tt->tt_timer,
tt->tt_nextc - tick, tcp_timer, (void *)inp);
} else {
CTR2(KTR_NET, "%p %s callout_stop", tp, __func__);
callout_stop(&tt->tt_timer);
tt->tt_nextc = 0;
}
return;
}
int
tcp_timer_active(struct tcpcb *tp, int timer_type)
{
switch (timer_type) {
case TT_DELACK:
CTR3(KTR_NET, "%p %s TT_DELACK %i",
tp, __func__, tp->t_timers->tt_delack);
return (tp->t_timers->tt_delack ? 1 : 0);
break;
case TT_REXMT:
CTR3(KTR_NET, "%p %s TT_REXMT %i",
tp, __func__, tp->t_timers->tt_rexmt);
return (tp->t_timers->tt_rexmt ? 1 : 0);
break;
case TT_PERSIST:
CTR3(KTR_NET, "%p %s TT_PERSIST %i",
tp, __func__, tp->t_timers->tt_persist);
return (tp->t_timers->tt_persist ? 1 : 0);
break;
case TT_KEEP:
CTR3(KTR_NET, "%p %s TT_KEEP %i",
tp, __func__, tp->t_timers->tt_keep);
return (tp->t_timers->tt_keep ? 1 : 0);
break;
case TT_2MSL:
CTR3(KTR_NET, "%p %s TT_2MSL %i",
tp, __func__, tp->t_timers->tt_2msl);
return (tp->t_timers->tt_2msl ? 1 : 0);
break;
}
return (0);
}
static void
tcp_timer(void *xinp)
{
struct inpcb *inp = (struct inpcb *)xinp;
struct tcpcb *tp = intotcpcb(inp);
struct tcp_timer *tt;
int tick = ticks;
int down, timer;
/* INP lock was obtained by callout. */
INP_LOCK_ASSERT(inp);
/*
* We've got a couple of race conditions here:
* - The tcpcb was converted into a compressed TW pcb. All our
* timers have been stopped while this callout already tried
* to obtain the inpcb lock. TW pcbs have their own timers
* and we just return.
*/
if (inp->inp_vflag & INP_TIMEWAIT)
return;
/*
* - The tcpcb was discarded. All our timers have been stopped
* while this callout already tried to obtain the inpcb lock
* and we just return.
*/
if (tp == NULL)
return;
tt = tp->t_timers; /* Initialize. */
CTR6(KTR_NET, "%p %s inp %p active %x tick %i nextc %i",
tp, __func__, inp, tt->tt_active, tick, tt->tt_nextc);
/*
* - We may have been waiting on the lock while the tcpcb has
* been scheduled for destruction. In this case no active
* timers remain and we just return.
*/
if (tt->tt_active == 0)
goto done;
/*
* - The timer was rescheduled while this callout was already
* waiting on the lock. This may happen when a packet just
* came in. Rescan and reschedule the the timer in case we
* just turned it off.
*/
if (tick < tt->tt_nextc)
goto rescan;
/*
* Mark as done. The active bit in struct callout is not
* automatically cleared. See callout(9) for more info.
* In tcp_discardcb() we depend on the correctly cleared
* active bit for faster processing.
*/
callout_deactivate(&tt->tt_timer);
/* Check which timer has fired and remove this timer activation. */
timer = tt->tt_active;
tt->tt_active = 0;
tt->tt_nextc = 0;
switch (timer) {
case TT_DELACK:
CTR2(KTR_NET, "%p %s running TT_DELACK", tp, __func__);
tt->tt_delack = 0;
down = tcp_timer_delack(tp, inp); /* down == 0 */
break;
case TT_REXMT:
CTR2(KTR_NET, "%p %s running TT_REXMT", tp, __func__);
tt->tt_rexmt = 0;
down = tcp_timer_rexmt(tp, inp);
break;
case TT_PERSIST:
CTR2(KTR_NET, "%p %s running TT_PERSIST", tp, __func__);
tt->tt_persist = 0;
down = tcp_timer_persist(tp, inp);
break;
case TT_KEEP:
CTR2(KTR_NET, "%p %s running TT_KEEP", tp, __func__);
tt->tt_keep = 0;
down = tcp_timer_keep(tp, inp);
break;
case TT_2MSL:
CTR2(KTR_NET, "%p %s running TT_2MSL", tp, __func__);
tt->tt_2msl = 0;
down = tcp_timer_2msl(tp, inp);
break;
default:
CTR2(KTR_NET, "%p %s running nothing", tp, __func__);
down = 0;
}
CTR4(KTR_NET, "%p %s down %i active %x",
tp, __func__, down, tt->tt_active);
/* Do we still exist? */
if (down)
goto shutdown;
rescan:
/* Rescan if no timer was reactivated above. */
if (tt->tt_active == 0)
tcp_timer_activate(tp, 0, 0);
done:
INP_UNLOCK(inp); /* CALLOUT_RETURNUNLOCKED */
return;
shutdown:
INP_UNLOCK(inp); /* Prevent LOR at expense of race. */
INP_INFO_WLOCK(&tcbinfo);
INP_LOCK(inp);
/*
* XXX: When our tcpcb went into TIMEWAIT, is gone or no
* longer the one we used to work with we've lost the race.
* This race is inherent in the current socket/inpcb life
* cycle system.
*/
if ((inp->inp_vflag & INP_TIMEWAIT) || inp->inp_ppcb == NULL ||
inp->inp_ppcb != tp) {
CTR3(KTR_NET, "%p %s inp %p lost shutdown race",
tp, __func__, inp);
tcp_timer_race++;
INP_UNLOCK(inp); /* CALLOUT_RETURNUNLOCKED */
INP_INFO_WUNLOCK(&tcbinfo);
return;
}
KASSERT(tp == inp->inp_ppcb, ("%s: tp changed", __func__));
/* Shutdown the connection. */
switch (down) {
case 1:
tp = tcp_close(tp);
break;
case 2:
tp = tcp_drop(tp,
tp->t_softerror ? tp->t_softerror : ETIMEDOUT);
break;
}
CTR3(KTR_NET, "%p %s inp %p after shutdown", tp, __func__, inp);
if (tp)
INP_UNLOCK(inp); /* CALLOUT_RETURNUNLOCKED */
INP_INFO_WUNLOCK(&tcbinfo);
return;
}
/*
* TCP timer processing.
*/
static int
tcp_timer_delack(struct tcpcb *tp, struct inpcb *inp)
void
tcp_timer_delack(void *xtp)
{
struct tcpcb *tp = xtp;
struct inpcb *inp;
INP_INFO_RLOCK(&tcbinfo);
inp = tp->t_inpcb;
/*
* XXXRW: While this assert is in fact correct, bugs in the tcpcb
* tear-down mean we need it as a work-around for races between
* timers and tcp_discardcb().
*
* KASSERT(inp != NULL, ("tcp_timer_delack: inp == NULL"));
*/
if (inp == NULL) {
tcp_timer_race++;
INP_INFO_RUNLOCK(&tcbinfo);
return;
}
INP_LOCK(inp);
INP_INFO_RUNLOCK(&tcbinfo);
if ((inp->inp_vflag & INP_DROPPED) || callout_pending(tp->tt_delack)
|| !callout_active(tp->tt_delack)) {
INP_UNLOCK(inp);
return;
}
callout_deactivate(tp->tt_delack);
tp->t_flags |= TF_ACKNOW;
tcpstat.tcps_delack++;
(void) tcp_output(tp);
return (0);
INP_UNLOCK(inp);
}
static int
tcp_timer_2msl(struct tcpcb *tp, struct inpcb *inp)
void
tcp_timer_2msl(void *xtp)
{
struct tcpcb *tp = xtp;
struct inpcb *inp;
#ifdef TCPDEBUG
int ostate;
ostate = tp->t_state;
#endif
/*
* XXXRW: Does this actually happen?
*/
INP_INFO_WLOCK(&tcbinfo);
inp = tp->t_inpcb;
/*
* XXXRW: While this assert is in fact correct, bugs in the tcpcb
* tear-down mean we need it as a work-around for races between
* timers and tcp_discardcb().
*
* KASSERT(inp != NULL, ("tcp_timer_2msl: inp == NULL"));
*/
if (inp == NULL) {
tcp_timer_race++;
INP_INFO_WUNLOCK(&tcbinfo);
return;
}
INP_LOCK(inp);
tcp_free_sackholes(tp);
if ((inp->inp_vflag & INP_DROPPED) || callout_pending(tp->tt_2msl) ||
!callout_active(tp->tt_2msl)) {
INP_UNLOCK(tp->t_inpcb);
INP_INFO_WUNLOCK(&tcbinfo);
return;
}
callout_deactivate(tp->tt_2msl);
/*
* 2 MSL timeout in shutdown went off. If we're closed but
* still waiting for peer to close and connection has been idle
@ -454,35 +226,62 @@ tcp_timer_2msl(struct tcpcb *tp, struct inpcb *inp)
* Ignore fact that there were recent incoming segments.
*/
if (tcp_fast_finwait2_recycle && tp->t_state == TCPS_FIN_WAIT_2 &&
tp->t_inpcb->inp_socket &&
tp->t_inpcb && tp->t_inpcb->inp_socket &&
(tp->t_inpcb->inp_socket->so_rcv.sb_state & SBS_CANTRCVMORE)) {
tcpstat.tcps_finwait2_drops++;
return (1); /* tcp_close */
tp = tcp_close(tp);
} else {
if (tp->t_state != TCPS_TIME_WAIT &&
(ticks - tp->t_rcvtime) <= tcp_maxidle)
tcp_timer_activate(tp, TT_2MSL, tcp_keepintvl);
else
return (1); /* tcp_close */
}
callout_reset(tp->tt_2msl, tcp_keepintvl,
tcp_timer_2msl, tp);
else
tp = tcp_close(tp);
}
#ifdef TCPDEBUG
if (tp->t_inpcb->inp_socket->so_options & SO_DEBUG)
tcp_trace(TA_USER, ostate, tp, (void *)0, (struct tcphdr *)0,
PRU_SLOWTIMO);
#endif
return (0);
if (tp != NULL)
INP_UNLOCK(inp);
INP_INFO_WUNLOCK(&tcbinfo);
}
static int
tcp_timer_keep(struct tcpcb *tp, struct inpcb *inp)
void
tcp_timer_keep(void *xtp)
{
struct tcpcb *tp = xtp;
struct tcptemp *t_template;
struct inpcb *inp;
#ifdef TCPDEBUG
int ostate;
ostate = tp->t_state;
#endif
INP_INFO_WLOCK(&tcbinfo);
inp = tp->t_inpcb;
/*
* XXXRW: While this assert is in fact correct, bugs in the tcpcb
* tear-down mean we need it as a work-around for races between
* timers and tcp_discardcb().
*
* KASSERT(inp != NULL, ("tcp_timer_keep: inp == NULL"));
*/
if (inp == NULL) {
tcp_timer_race++;
INP_INFO_WUNLOCK(&tcbinfo);
return;
}
INP_LOCK(inp);
if ((inp->inp_vflag & INP_DROPPED) || callout_pending(tp->tt_keep)
|| !callout_active(tp->tt_keep)) {
INP_UNLOCK(inp);
INP_INFO_WUNLOCK(&tcbinfo);
return;
}
callout_deactivate(tp->tt_keep);
/*
* Keep-alive timer went off; send something
* or drop connection if idle for too long.
@ -514,30 +313,65 @@ tcp_timer_keep(struct tcpcb *tp, struct inpcb *inp)
tp->rcv_nxt, tp->snd_una - 1, 0);
(void) m_free(dtom(t_template));
}
tcp_timer_activate(tp, TT_KEEP, tcp_keepintvl);
callout_reset(tp->tt_keep, tcp_keepintvl, tcp_timer_keep, tp);
} else
tcp_timer_activate(tp, TT_KEEP, tcp_keepidle);
callout_reset(tp->tt_keep, tcp_keepidle, tcp_timer_keep, tp);
#ifdef TCPDEBUG
if (inp->inp_socket->so_options & SO_DEBUG)
tcp_trace(TA_USER, ostate, tp, (void *)0, (struct tcphdr *)0,
PRU_SLOWTIMO);
#endif
return (0);
INP_UNLOCK(inp);
INP_INFO_WUNLOCK(&tcbinfo);
return;
dropit:
tcpstat.tcps_keepdrops++;
return (2); /* tcp_drop() */
tp = tcp_drop(tp, ETIMEDOUT);
#ifdef TCPDEBUG
if (tp != NULL && (tp->t_inpcb->inp_socket->so_options & SO_DEBUG))
tcp_trace(TA_USER, ostate, tp, (void *)0, (struct tcphdr *)0,
PRU_SLOWTIMO);
#endif
if (tp != NULL)
INP_UNLOCK(tp->t_inpcb);
INP_INFO_WUNLOCK(&tcbinfo);
}
static int
tcp_timer_persist(struct tcpcb *tp, struct inpcb *inp)
void
tcp_timer_persist(void *xtp)
{
struct tcpcb *tp = xtp;
struct inpcb *inp;
#ifdef TCPDEBUG
int ostate;
ostate = tp->t_state;
#endif
INP_INFO_WLOCK(&tcbinfo);
inp = tp->t_inpcb;
/*
* XXXRW: While this assert is in fact correct, bugs in the tcpcb
* tear-down mean we need it as a work-around for races between
* timers and tcp_discardcb().
*
* KASSERT(inp != NULL, ("tcp_timer_persist: inp == NULL"));
*/
if (inp == NULL) {
tcp_timer_race++;
INP_INFO_WUNLOCK(&tcbinfo);
return;
}
INP_LOCK(inp);
if ((inp->inp_vflag & INP_DROPPED) || callout_pending(tp->tt_persist)
|| !callout_active(tp->tt_persist)) {
INP_UNLOCK(inp);
INP_INFO_WUNLOCK(&tcbinfo);
return;
}
callout_deactivate(tp->tt_persist);
/*
* Persistance timer into zero window.
* Force a byte to be output, if possible.
@ -554,29 +388,59 @@ tcp_timer_persist(struct tcpcb *tp, struct inpcb *inp)
((ticks - tp->t_rcvtime) >= tcp_maxpersistidle ||
(ticks - tp->t_rcvtime) >= TCP_REXMTVAL(tp) * tcp_totbackoff)) {
tcpstat.tcps_persistdrop++;
return (2); /* tcp_drop() */
tp = tcp_drop(tp, ETIMEDOUT);
goto out;
}
tcp_setpersist(tp);
tp->t_flags |= TF_FORCEDATA;
(void) tcp_output(tp);
tp->t_flags &= ~TF_FORCEDATA;
out:
#ifdef TCPDEBUG
if (tp != NULL && tp->t_inpcb->inp_socket->so_options & SO_DEBUG)
tcp_trace(TA_USER, ostate, tp, NULL, NULL, PRU_SLOWTIMO);
#endif
return (0);
if (tp != NULL)
INP_UNLOCK(inp);
INP_INFO_WUNLOCK(&tcbinfo);
}
static int
tcp_timer_rexmt(struct tcpcb *tp, struct inpcb *inp)
void
tcp_timer_rexmt(void * xtp)
{
struct tcpcb *tp = xtp;
int rexmt;
int headlocked;
struct inpcb *inp;
#ifdef TCPDEBUG
int ostate;
ostate = tp->t_state;
#endif
INP_INFO_WLOCK(&tcbinfo);
headlocked = 1;
inp = tp->t_inpcb;
/*
* XXXRW: While this assert is in fact correct, bugs in the tcpcb
* tear-down mean we need it as a work-around for races between
* timers and tcp_discardcb().
*
* KASSERT(inp != NULL, ("tcp_timer_rexmt: inp == NULL"));
*/
if (inp == NULL) {
tcp_timer_race++;
INP_INFO_WUNLOCK(&tcbinfo);
return;
}
INP_LOCK(inp);
if ((inp->inp_vflag & INP_DROPPED) || callout_pending(tp->tt_rexmt)
|| !callout_active(tp->tt_rexmt)) {
INP_UNLOCK(inp);
INP_INFO_WUNLOCK(&tcbinfo);
return;
}
callout_deactivate(tp->tt_rexmt);
tcp_free_sackholes(tp);
/*
* Retransmission timer went off. Message has not
@ -586,8 +450,12 @@ tcp_timer_rexmt(struct tcpcb *tp, struct inpcb *inp)
if (++tp->t_rxtshift > TCP_MAXRXTSHIFT) {
tp->t_rxtshift = TCP_MAXRXTSHIFT;
tcpstat.tcps_timeoutdrop++;
return (2); /* tcp_drop() */
tp = tcp_drop(tp, tp->t_softerror ?
tp->t_softerror : ETIMEDOUT);
goto out;
}
INP_INFO_WUNLOCK(&tcbinfo);
headlocked = 0;
if (tp->t_rxtshift == 1) {
/*
* first retransmit; record ssthresh and cwnd so they can
@ -602,9 +470,9 @@ tcp_timer_rexmt(struct tcpcb *tp, struct inpcb *inp)
tp->snd_ssthresh_prev = tp->snd_ssthresh;
tp->snd_recover_prev = tp->snd_recover;
if (IN_FASTRECOVERY(tp))
tp->t_flags |= TF_WASFRECOVERY;
tp->t_flags |= TF_WASFRECOVERY;
else
tp->t_flags &= ~TF_WASFRECOVERY;
tp->t_flags &= ~TF_WASFRECOVERY;
tp->t_badrxtwin = ticks + (tp->t_srtt >> (TCP_RTT_SHIFT + 1));
}
tcpstat.tcps_rexmttimeo++;
@ -683,10 +551,78 @@ tcp_timer_rexmt(struct tcpcb *tp, struct inpcb *inp)
EXIT_FASTRECOVERY(tp);
(void) tcp_output(tp);
out:
#ifdef TCPDEBUG
if (tp != NULL && (tp->t_inpcb->inp_socket->so_options & SO_DEBUG))
tcp_trace(TA_USER, ostate, tp, (void *)0, (struct tcphdr *)0,
PRU_SLOWTIMO);
#endif
return (0);
if (tp != NULL)
INP_UNLOCK(inp);
if (headlocked)
INP_INFO_WUNLOCK(&tcbinfo);
}
void
tcp_timer_activate(struct tcpcb *tp, int timer_type, u_int delta)
{
struct callout *t_callout;
void *f_callout;
switch (timer_type) {
case TT_DELACK:
t_callout = tp->tt_delack;
f_callout = tcp_timer_delack;
break;
case TT_REXMT:
t_callout = tp->tt_rexmt;
f_callout = tcp_timer_rexmt;
break;
case TT_PERSIST:
t_callout = tp->tt_persist;
f_callout = tcp_timer_persist;
break;
case TT_KEEP:
t_callout = tp->tt_keep;
f_callout = tcp_timer_keep;
break;
case TT_2MSL:
t_callout = tp->tt_2msl;
f_callout = tcp_timer_2msl;
break;
default:
panic("bad timer_type");
}
if (delta == 0) {
callout_stop(t_callout);
} else {
callout_reset(t_callout, delta, f_callout, tp);
}
}
int
tcp_timer_active(struct tcpcb *tp, int timer_type)
{
struct callout *t_callout;
switch (timer_type) {
case TT_DELACK:
t_callout = tp->tt_delack;
break;
case TT_REXMT:
t_callout = tp->tt_rexmt;
break;
case TT_PERSIST:
t_callout = tp->tt_persist;
break;
case TT_KEEP:
t_callout = tp->tt_keep;
break;
case TT_2MSL:
t_callout = tp->tt_2msl;
break;
default:
panic("bad timer_type");
}
return callout_active(t_callout);
}

15
sys/netinet/tcp_timer.h
View File

@ -141,21 +141,11 @@ static const char *tcptimers[] =
#ifdef _KERNEL
struct tcp_timer {
struct callout tt_timer;
int tt_nextc; /* next callout time in time_uptime */
int tt_active; /* engaged callouts */
#define TT_DELACK 0x01
#define TT_REXMT 0x02
#define TT_PERSIST 0x04
#define TT_KEEP 0x08
#define TT_2MSL 0x10
int tt_delack;
int tt_rexmt;
int tt_persist;
int tt_keep;
int tt_2msl;
};
extern int tcp_keepinit; /* time to establish connection */
extern int tcp_keepidle; /* time before keepalive probes begin */
@ -173,8 +163,13 @@ extern int tcp_finwait2_timeout;
extern int tcp_fast_finwait2_recycle;
void tcp_timer_init(void);
void tcp_timer_2msl(void *xtp);
struct tcptw *
tcp_tw_2msl_scan(int _reuse); /* XXX temporary */
void tcp_timer_keep(void *xtp);
void tcp_timer_persist(void *xtp);
void tcp_timer_rexmt(void *xtp);
void tcp_timer_delack(void *xtp);
#endif /* _KERNEL */

11
sys/netinet/tcp_usrreq.c
View File

@ -1743,15 +1743,12 @@ db_print_tcpcb(struct tcpcb *tp, const char *name, int indent)
LIST_FIRST(&tp->t_segq), tp->t_segqlen, tp->t_dupacks);
db_print_indent(indent);
db_printf("t_inpcb: %p t_timers: %p tt_active: %x\n",
tp->t_inpcb, tp->t_timers, tp->t_timers->tt_active);
db_printf("tt_rexmt: %p tt_persist: %p tt_keep: %p\n",
tp->tt_rexmt, tp->tt_persist, tp->tt_keep);
db_print_indent(indent);
db_printf("tt_delack: %i tt_rexmt: %i tt_keep: %i "
"tt_persist: %i tt_2msl: %i\n",
tp->t_timers->tt_delack, tp->t_timers->tt_rexmt,
tp->t_timers->tt_keep, tp->t_timers->tt_persist,
tp->t_timers->tt_2msl);
db_printf("tt_2msl: %p tt_delack: %p t_inpcb: %p\n", tp->tt_2msl,
tp->tt_delack, tp->t_inpcb);
db_print_indent(indent);
db_printf("t_state: %d (", tp->t_state);

6
sys/netinet/tcp_var.h
View File

@ -96,7 +96,11 @@ struct tcpcb {
int t_segqlen; /* segment reassembly queue length */
int t_dupacks; /* consecutive dup acks recd */
struct tcp_timer *t_timers; /* retransmit timer */
struct callout *tt_rexmt; /* retransmit timer */
struct callout *tt_persist; /* retransmit persistence */
struct callout *tt_keep; /* keepalive */
struct callout *tt_2msl; /* 2*msl TIME_WAIT timer */
struct callout *tt_delack; /* delayed ACK timer */
struct inpcb *t_inpcb; /* back pointer to internet pcb */
int t_state; /* state of this connection */