/*
- * Copyright (c) 2000-2011 Apple Inc. All rights reserved.
+ * Copyright (c) 2000-2014 Apple Inc. All rights reserved.
*
* @APPLE_OSREFERENCE_LICENSE_HEADER_START@
*
#include <sys/mcache.h>
#include <sys/queue.h>
#include <kern/locks.h>
-
#include <kern/cpu_number.h> /* before tcp_seq.h, for tcp_random18() */
+#include <mach/boolean.h>
#include <net/route.h>
+#include <net/if_var.h>
#include <netinet/in.h>
#include <netinet/in_systm.h>
#endif
#include <sys/kdebug.h>
#include <mach/sdt.h>
+#include <netinet/mptcp_var.h>
extern void postevent(struct socket *, struct sockbuf *,
int);
panic("Bad link elm %p prev->next != elm", (elm)); \
} while(0)
+/* tcp timer list */
+struct tcptimerlist tcp_timer_list;
+
+/* List of pcbs in timewait state, protected by tcbinfo's ipi_lock */
+struct tcptailq tcp_tw_tailq;
+
static int background_io_trigger = 5;
SYSCTL_INT(_net_inet_tcp, OID_AUTO, background_io_trigger, CTLFLAG_RW | CTLFLAG_LOCKED,
&background_io_trigger, 0, "Background IO Trigger Setting");
SYSCTL_PROC(_net_inet_tcp, TCPCTL_KEEPINTVL, keepintvl, CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_LOCKED,
&tcp_keepintvl, 0, sysctl_msec_to_ticks, "I", "");
+int tcp_keepcnt;
+SYSCTL_INT(_net_inet_tcp, OID_AUTO, keepcnt, CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_LOCKED,
+ &tcp_keepcnt, 0, "number of times to repeat keepalive");
+
int tcp_msl;
SYSCTL_PROC(_net_inet_tcp, OID_AUTO, msl, CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_LOCKED,
&tcp_msl, 0, sysctl_msec_to_ticks, "I", "Maximum segment lifetime");
&tcp_broken_peer_syn_rxmit_thres, 0, "Number of retransmitted SYNs before "
"TCP disables rfc1323 and rfc1644 during the rest of attempts");
+/* A higher threshold on local connections for disabling RFC 1323 options */
+static int tcp_broken_peer_syn_rxmit_thres_local = 10;
+SYSCTL_INT(_net_inet_tcp, OID_AUTO, broken_peer_syn_rexmit_thres_local,
+ CTLFLAG_RW | CTLFLAG_LOCKED, &tcp_broken_peer_syn_rxmit_thres_local, 0,
+ "Number of retransmitted SYNs before disabling RFC 1323 options on local connections");
+
static int tcp_timer_advanced = 0;
SYSCTL_INT(_net_inet_tcp, OID_AUTO, tcp_timer_advanced, CTLFLAG_RD | CTLFLAG_LOCKED,
&tcp_timer_advanced, 0, "Number of times one of the timers was advanced");
SYSCTL_INT(_net_inet_tcp, OID_AUTO, pmtud_blackhole_mss, CTLFLAG_RW | CTLFLAG_LOCKED,
&tcp_pmtud_black_hole_mss, 0, "Path MTU Discovery Black Hole Detection lowered MSS");
-static int tcp_keepcnt = TCPTV_KEEPCNT;
-static int tcp_gc_done = FALSE; /* perfromed garbage collection of "used" sockets */
+/* performed garbage collection of "used" sockets */
+static boolean_t tcp_gc_done = FALSE;
+
/* max idle probes */
int tcp_maxpersistidle;
- /* max idle time in persist */
-int tcp_maxidle;
/* TCP delack timer is set to 100 ms. Since the processing of timer list in fast
* mode will happen no faster than 100 ms, the delayed ack timer will fire some where
*/
int tcp_delack = TCP_RETRANSHZ / 10;
-struct inpcbhead time_wait_slots[N_TIME_WAIT_SLOTS];
-int cur_tw_slot = 0;
-
-/* tcp timer list */
-struct tcptimerlist tcp_timer_list;
+#if MPTCP
+/*
+ * MP_JOIN retransmission of 3rd ACK will be every 500 msecs without backoff
+ */
+int tcp_jack_rxmt = TCP_RETRANSHZ / 2;
+#endif /* MPTCP */
/* The frequency of running through the TCP timer list in
* fast and slow mode can be configured.
static uint32_t tcp_run_conn_timer(struct tcpcb *tp, uint16_t *next_index);
static void tcp_sched_timers(struct tcpcb *tp);
static inline void tcp_set_lotimer_index(struct tcpcb *);
+static void tcp_rexmt_save_state(struct tcpcb *tp);
+void tcp_remove_from_time_wait(struct inpcb *inp);
/* Macro to compare two timers. If there is a reset of the sign bit, it is
* safe to assume that the timer has wrapped around. By doing signed comparision,
/* Returns true if the timer is on the timer list */
#define TIMER_IS_ON_LIST(tp) ((tp)->t_flags & TF_TIMER_ONLIST)
+/* Run the TCP timerlist atleast once every hour */
+#define TCP_TIMERLIST_MAX_OFFSET (60 * 60 * TCP_RETRANSHZ)
-void add_to_time_wait_locked(struct tcpcb *tp, uint32_t delay);
+static void add_to_time_wait_locked(struct tcpcb *tp, uint32_t delay);
void add_to_time_wait(struct tcpcb *tp, uint32_t delay) ;
-static void tcp_garbage_collect(struct inpcb *, int);
+static boolean_t tcp_garbage_collect(struct inpcb *, int);
-void add_to_time_wait_locked(struct tcpcb *tp, uint32_t delay)
+/*
+ * Add to tcp timewait list, delay is given in milliseconds.
+ */
+static void
+add_to_time_wait_locked(struct tcpcb *tp, uint32_t delay)
{
- int tw_slot;
- struct inpcbinfo *pcbinfo = &tcbinfo;
+ struct inpcbinfo *pcbinfo = &tcbinfo;
+ struct inpcb *inp = tp->t_inpcb;
uint32_t timer;
- /* pcb list should be locked when we get here */
- lck_rw_assert(pcbinfo->mtx, LCK_RW_ASSERT_EXCLUSIVE);
-
- LIST_REMOVE(tp->t_inpcb, inp_list);
-
- /* if (tp->t_timer[TCPT_2MSL] <= 0)
- tp->t_timer[TCPT_2MSL] = 1; */
-
- /*
- * Because we're pulling this pcb out of the main TCP pcb list,
- * we need to recalculate the TCPT_2MSL timer value for tcp_slowtimo
- * higher timer granularity.
- */
+ /* pcb list should be locked when we get here */
+ lck_rw_assert(pcbinfo->ipi_lock, LCK_RW_ASSERT_EXCLUSIVE);
- timer = (delay / TCP_RETRANSHZ) * PR_SLOWHZ;
- tp->t_rcvtime = (tp->t_rcvtime / TCP_RETRANSHZ) * PR_SLOWHZ;
+ /* We may get here multiple times, so check */
+ if (!(inp->inp_flags2 & INP2_TIMEWAIT)) {
+ pcbinfo->ipi_twcount++;
+ inp->inp_flags2 |= INP2_TIMEWAIT;
+
+ /* Remove from global inp list */
+ LIST_REMOVE(inp, inp_list);
+ } else {
+ TAILQ_REMOVE(&tcp_tw_tailq, tp, t_twentry);
+ }
- tp->t_rcvtime += timer & (N_TIME_WAIT_SLOTS - 1);
+ /* Compute the time at which this socket can be closed */
+ timer = tcp_now + delay;
+
+ /* We will use the TCPT_2MSL timer for tracking this delay */
- tw_slot = (timer & (N_TIME_WAIT_SLOTS - 1)) + cur_tw_slot;
- if (tw_slot >= N_TIME_WAIT_SLOTS)
- tw_slot -= N_TIME_WAIT_SLOTS;
+ if (TIMER_IS_ON_LIST(tp))
+ tcp_remove_timer(tp);
+ tp->t_timer[TCPT_2MSL] = timer;
- LIST_INSERT_HEAD(&time_wait_slots[tw_slot], tp->t_inpcb, inp_list);
+ TAILQ_INSERT_TAIL(&tcp_tw_tailq, tp, t_twentry);
}
-void add_to_time_wait(struct tcpcb *tp, uint32_t delay)
+void
+add_to_time_wait(struct tcpcb *tp, uint32_t delay)
{
- struct inpcbinfo *pcbinfo = &tcbinfo;
-
- if (!lck_rw_try_lock_exclusive(pcbinfo->mtx)) {
+ struct inpcbinfo *pcbinfo = &tcbinfo;
+
+ if (!lck_rw_try_lock_exclusive(pcbinfo->ipi_lock)) {
tcp_unlock(tp->t_inpcb->inp_socket, 0, 0);
- lck_rw_lock_exclusive(pcbinfo->mtx);
+ lck_rw_lock_exclusive(pcbinfo->ipi_lock);
tcp_lock(tp->t_inpcb->inp_socket, 0, 0);
}
add_to_time_wait_locked(tp, delay);
- lck_rw_done(pcbinfo->mtx);
+ lck_rw_done(pcbinfo->ipi_lock);
+
+ inpcb_gc_sched(pcbinfo, INPCB_TIMER_LAZY);
}
-static void
+/* If this is on time wait queue, remove it. */
+void
+tcp_remove_from_time_wait(struct inpcb *inp)
+{
+ struct tcpcb *tp = intotcpcb(inp);
+ if (inp->inp_flags2 & INP2_TIMEWAIT)
+ TAILQ_REMOVE(&tcp_tw_tailq, tp, t_twentry);
+}
+
+static boolean_t
tcp_garbage_collect(struct inpcb *inp, int istimewait)
{
+ boolean_t active = FALSE;
struct socket *so;
struct tcpcb *tp;
* overflow sockets that are eligible for garbage collection have
* their usecounts set to 1.
*/
- if (so->so_usecount > 1 || !lck_mtx_try_lock_spin(&inp->inpcb_mtx))
- return;
+ if (!lck_mtx_try_lock_spin(&inp->inpcb_mtx))
+ return (TRUE);
/* Check again under the lock */
if (so->so_usecount > 1) {
+ if (inp->inp_wantcnt == WNT_STOPUSING)
+ active = TRUE;
lck_mtx_unlock(&inp->inpcb_mtx);
- return;
+ return (active);
+ }
+
+ if (istimewait &&
+ TSTMP_GEQ(tcp_now, tp->t_timer[TCPT_2MSL]) &&
+ tp->t_state != TCPS_CLOSED) {
+ /* Become a regular mutex */
+ lck_mtx_convert_spin(&inp->inpcb_mtx);
+ tcp_close(tp);
}
/*
* only if we are called to clean up the time wait slots, since
* tcp_dropdropablreq() considers a socket to have been fully
* dropped after add_to_time_wait() is finished.
- * Also handle the case of connections getting closed by the peer while in the queue as
- * seen with rdar://6422317
- *
+ * Also handle the case of connections getting closed by the peer
+ * while in the queue as seen with rdar://6422317
+ *
*/
- if (so->so_usecount == 1 &&
+ if (so->so_usecount == 1 &&
((istimewait && (so->so_flags & SOF_OVERFLOW)) ||
- ((tp != NULL) && (tp->t_state == TCPS_CLOSED) && (so->so_head != NULL)
- && ((so->so_state & (SS_INCOMP|SS_CANTSENDMORE|SS_CANTRCVMORE)) ==
- (SS_INCOMP|SS_CANTSENDMORE|SS_CANTRCVMORE))))) {
+ ((tp != NULL) && (tp->t_state == TCPS_CLOSED) &&
+ (so->so_head != NULL) &&
+ ((so->so_state & (SS_INCOMP|SS_CANTSENDMORE|SS_CANTRCVMORE)) ==
+ (SS_INCOMP|SS_CANTSENDMORE|SS_CANTRCVMORE))))) {
if (inp->inp_state != INPCB_STATE_DEAD) {
/* Become a regular mutex */
lck_mtx_convert_spin(&inp->inpcb_mtx);
#if INET6
- if (INP_CHECK_SOCKAF(so, AF_INET6))
+ if (SOCK_CHECK_DOM(so, PF_INET6))
in6_pcbdetach(inp);
else
#endif /* INET6 */
- in_pcbdetach(inp);
+ in_pcbdetach(inp);
}
so->so_usecount--;
+ if (inp->inp_wantcnt == WNT_STOPUSING)
+ active = TRUE;
lck_mtx_unlock(&inp->inpcb_mtx);
- return;
+ return (active);
} else if (inp->inp_wantcnt != WNT_STOPUSING) {
lck_mtx_unlock(&inp->inpcb_mtx);
- return;
+ return (FALSE);
}
/*
- * We get here because the PCB is no longer searchable (WNT_STOPUSING);
- * detach (if needed) and dispose if it is dead (usecount is 0). This
- * covers all cases, including overflow sockets and those that are
- * considered as "embryonic", i.e. created by sonewconn() in TCP input
- * path, and have not yet been committed. For the former, we reduce
- * the usecount to 0 as done by the code above. For the latter, the
- * usecount would have reduced to 0 as part calling soabort() when the
+ * We get here because the PCB is no longer searchable
+ * (WNT_STOPUSING); detach (if needed) and dispose if it is dead
+ * (usecount is 0). This covers all cases, including overflow
+ * sockets and those that are considered as "embryonic",
+ * i.e. created by sonewconn() in TCP input path, and have
+ * not yet been committed. For the former, we reduce the usecount
+ * to 0 as done by the code above. For the latter, the usecount
+ * would have reduced to 0 as part calling soabort() when the
* socket is dropped at the end of tcp_input().
*/
if (so->so_usecount == 0) {
struct tcpcb *, tp, int32_t, TCPS_CLOSED);
/* Become a regular mutex */
lck_mtx_convert_spin(&inp->inpcb_mtx);
+
+ /*
+ * If this tp still happens to be on the timer list,
+ * take it out
+ */
+ if (TIMER_IS_ON_LIST(tp)) {
+ tcp_remove_timer(tp);
+ }
+
if (inp->inp_state != INPCB_STATE_DEAD) {
#if INET6
- if (INP_CHECK_SOCKAF(so, AF_INET6))
+ if (SOCK_CHECK_DOM(so, PF_INET6))
in6_pcbdetach(inp);
else
#endif /* INET6 */
- in_pcbdetach(inp);
+ in_pcbdetach(inp);
}
in_pcbdispose(inp);
- } else {
- lck_mtx_unlock(&inp->inpcb_mtx);
+ return (FALSE);
}
+
+ lck_mtx_unlock(&inp->inpcb_mtx);
+ return (TRUE);
}
+/*
+ * TCP garbage collector callback (inpcb_timer_func_t).
+ *
+ * Returns the number of pcbs that will need to be gc-ed soon,
+ * returnining > 0 will keep timer active.
+ */
void
-tcp_slowtimo(void)
+tcp_gc(struct inpcbinfo *ipi)
{
struct inpcb *inp, *nxt;
- struct tcpcb *tp;
+ struct tcpcb *tw_tp, *tw_ntp;
#if TCPDEBUG
int ostate;
#endif
-
#if KDEBUG
static int tws_checked = 0;
#endif
- struct inpcbinfo *pcbinfo = &tcbinfo;
-
- KERNEL_DEBUG(DBG_FNC_TCP_SLOW | DBG_FUNC_START, 0,0,0,0,0);
-
- tcp_maxidle = tcp_keepcnt * tcp_keepintvl;
+ KERNEL_DEBUG(DBG_FNC_TCP_SLOW | DBG_FUNC_START, 0, 0, 0, 0, 0);
- /* Update tcp_now here as it may get used while processing the slow timer */
+ /*
+ * Update tcp_now here as it may get used while
+ * processing the slow timer.
+ */
calculate_tcp_clock();
- /* Garbage collect socket/tcpcb: We need to acquire the list lock
+ /*
+ * Garbage collect socket/tcpcb: We need to acquire the list lock
* exclusively to do this
*/
- if (lck_rw_try_lock_exclusive(pcbinfo->mtx) == FALSE) {
- if (tcp_gc_done == TRUE) { /* don't sweat it this time. cleanup was done last time */
+ if (lck_rw_try_lock_exclusive(ipi->ipi_lock) == FALSE) {
+ /* don't sweat it this time; cleanup was done last time */
+ if (tcp_gc_done == TRUE) {
tcp_gc_done = FALSE;
- KERNEL_DEBUG(DBG_FNC_TCP_SLOW | DBG_FUNC_END, tws_checked, cur_tw_slot,0,0,0);
- return; /* Upgrade failed and lost lock - give up this time. */
+ KERNEL_DEBUG(DBG_FNC_TCP_SLOW | DBG_FUNC_END,
+ tws_checked, cur_tw_slot, 0, 0, 0);
+ /* Lock upgrade failed, give up this round */
+ atomic_add_32(&ipi->ipi_gc_req.intimer_fast, 1);
+ return;
}
- lck_rw_lock_exclusive(pcbinfo->mtx); /* Upgrade failed, lost lock now take it again exclusive */
+ /* Upgrade failed, lost lock now take it again exclusive */
+ lck_rw_lock_exclusive(ipi->ipi_lock);
}
tcp_gc_done = TRUE;
- /*
- * Process the items in the current time-wait slot
- */
-#if KDEBUG
- tws_checked = 0;
-#endif
- KERNEL_DEBUG(DBG_FNC_TCP_SLOW | DBG_FUNC_NONE, tws_checked,0,0,0,0);
-
- LIST_FOREACH(inp, &time_wait_slots[cur_tw_slot], inp_list) {
-#if KDEBUG
- tws_checked++;
-#endif
-
- if (in_pcb_checkstate(inp, WNT_ACQUIRE, 0) == WNT_STOPUSING)
- continue;
-
- tcp_lock(inp->inp_socket, 1, 0);
-
- if (in_pcb_checkstate(inp, WNT_RELEASE, 1) == WNT_STOPUSING)
- goto twunlock;
-
- tp = intotcpcb(inp);
- if (tp == NULL) /* tp already closed, remove from list */
- goto twunlock;
-
- if (tp->t_timer[TCPT_2MSL] >= N_TIME_WAIT_SLOTS) {
- tp->t_timer[TCPT_2MSL] -= N_TIME_WAIT_SLOTS;
- tp->t_rcvtime += N_TIME_WAIT_SLOTS;
- }
- else
- tp->t_timer[TCPT_2MSL] = 0;
-
- if (tp->t_timer[TCPT_2MSL] == 0) {
+ LIST_FOREACH_SAFE(inp, &tcb, inp_list, nxt) {
+ if (tcp_garbage_collect(inp, 0))
+ atomic_add_32(&ipi->ipi_gc_req.intimer_fast, 1);
+ }
- /* That pcb is ready for a close */
- tcp_free_sackholes(tp);
- tp = tcp_close(tp);
+ /* Now cleanup the time wait ones */
+ TAILQ_FOREACH_SAFE(tw_tp, &tcp_tw_tailq, t_twentry, tw_ntp) {
+ /*
+ * We check the timestamp here without holding the
+ * socket lock for better performance. If there are
+ * any pcbs in time-wait, the timer will get rescheduled.
+ * Hence some error in this check can be tolerated.
+ *
+ * Sometimes a socket on time-wait queue can be closed if
+ * 2MSL timer expired but the application still has a
+ * usecount on it.
+ */
+ if (tw_tp->t_state == TCPS_CLOSED ||
+ TSTMP_GEQ(tcp_now, tw_tp->t_timer[TCPT_2MSL])) {
+ if (tcp_garbage_collect(tw_tp->t_inpcb, 1))
+ atomic_add_32(&ipi->ipi_gc_req.intimer_lazy, 1);
}
-twunlock:
- tcp_unlock(inp->inp_socket, 1, 0);
}
+ /* take into account pcbs that are still in time_wait_slots */
+ atomic_add_32(&ipi->ipi_gc_req.intimer_lazy, ipi->ipi_twcount);
- LIST_FOREACH_SAFE(inp, &tcb, inp_list, nxt) {
- tcp_garbage_collect(inp, 0);
- }
+ lck_rw_done(ipi->ipi_lock);
- /* Now cleanup the time wait ones */
- LIST_FOREACH_SAFE(inp, &time_wait_slots[cur_tw_slot], inp_list, nxt) {
- tcp_garbage_collect(inp, 1);
- }
+ /* Clean up the socache while we are here */
+ if (so_cache_timer())
+ atomic_add_32(&ipi->ipi_gc_req.intimer_lazy, 1);
- if (++cur_tw_slot >= N_TIME_WAIT_SLOTS)
- cur_tw_slot = 0;
-
- lck_rw_done(pcbinfo->mtx);
- KERNEL_DEBUG(DBG_FNC_TCP_SLOW | DBG_FUNC_END, tws_checked, cur_tw_slot,0,0,0);
+ KERNEL_DEBUG(DBG_FNC_TCP_SLOW | DBG_FUNC_END, tws_checked,
+ cur_tw_slot, 0, 0, 0);
+
+ return;
}
/*
static int tcp_totbackoff = 511; /* sum of tcp_backoff[] */
+static void tcp_rexmt_save_state(struct tcpcb *tp)
+{
+ u_int32_t fsize;
+ if (TSTMP_SUPPORTED(tp)) {
+ /*
+ * Since timestamps are supported on the connection,
+ * we can do recovery as described in rfc 4015.
+ */
+ fsize = tp->snd_max - tp->snd_una;
+ tp->snd_ssthresh_prev = max(fsize, tp->snd_ssthresh);
+ tp->snd_recover_prev = tp->snd_recover;
+ } else {
+ /*
+ * Timestamp option is not supported on this connection.
+ * Record ssthresh and cwnd so they can
+ * be recovered if this turns out to be a "bad" retransmit.
+ * A retransmit is considered "bad" if an ACK for this
+ * segment is received within RTT/2 interval; the assumption
+ * here is that the ACK was already in flight. See
+ * "On Estimating End-to-End Network Path Properties" by
+ * Allman and Paxson for more details.
+ */
+ tp->snd_cwnd_prev = tp->snd_cwnd;
+ tp->snd_ssthresh_prev = tp->snd_ssthresh;
+ tp->snd_recover_prev = tp->snd_recover;
+ if (IN_FASTRECOVERY(tp))
+ tp->t_flags |= TF_WASFRECOVERY;
+ else
+ tp->t_flags &= ~TF_WASFRECOVERY;
+ }
+ tp->t_srtt_prev = (tp->t_srtt >> TCP_RTT_SHIFT) + 2;
+ tp->t_rttvar_prev = (tp->t_rttvar >> TCP_RTTVAR_SHIFT);
+ tp->t_flagsext &= ~(TF_RECOMPUTE_RTT);
+}
+
/*
* TCP timer processing.
*/
int timer;
{
register int rexmt;
- struct socket *so_tmp;
+ struct socket *so;
struct tcptemp *t_template;
int optlen = 0;
int idle_time = 0;
int isipv6 = (tp->t_inpcb->inp_vflag & INP_IPV4) == 0;
#endif /* INET6 */
- so_tmp = tp->t_inpcb->inp_socket;
+ so = tp->t_inpcb->inp_socket;
idle_time = tcp_now - tp->t_rcvtime;
switch (timer) {
tcp_free_sackholes(tp);
if (tp->t_state != TCPS_TIME_WAIT &&
tp->t_state != TCPS_FIN_WAIT_2 &&
- ((idle_time > 0) && (idle_time < tcp_maxidle))) {
- tp->t_timer[TCPT_2MSL] = OFFSET_FROM_START(tp, (u_int32_t)tcp_keepintvl);
- }
- else {
+ ((idle_time > 0) && (idle_time < TCP_CONN_MAXIDLE(tp)))) {
+ tp->t_timer[TCPT_2MSL] = OFFSET_FROM_START(tp,
+ (u_int32_t)TCP_CONN_KEEPINTVL(tp));
+ } else {
tp = tcp_close(tp);
return(tp);
}
* to a longer retransmit interval and retransmit one segment.
*/
case TCPT_REXMT:
- tcp_free_sackholes(tp);
/* Drop a connection in the retransmit timer
* 1. If we have retransmitted more than TCP_MAXRXTSHIFT times
* 2. If the time spent in this retransmission episode is more than
* retransmitted the FIN 3 times without receiving an ack
*/
if (++tp->t_rxtshift > TCP_MAXRXTSHIFT ||
- (tp->rxt_conndroptime > 0 && tp->rxt_start > 0 &&
- (tcp_now - tp->rxt_start) >= tp->rxt_conndroptime) ||
+ (tp->t_rxt_conndroptime > 0 && tp->t_rxtstart > 0 &&
+ (tcp_now - tp->t_rxtstart) >= tp->t_rxt_conndroptime) ||
((tp->t_flagsext & TF_RXTFINDROP) != 0 &&
(tp->t_flags & TF_SENTFIN) != 0 &&
tp->t_rxtshift >= 4)) {
tcpstat.tcps_timeoutdrop++;
}
tp->t_rxtshift = TCP_MAXRXTSHIFT;
+ postevent(so, 0, EV_TIMEOUT);
+ soevent(so,
+ (SO_FILT_HINT_LOCKED|SO_FILT_HINT_TIMEOUT));
tp = tcp_drop(tp, tp->t_softerror ?
tp->t_softerror : ETIMEDOUT);
- postevent(so_tmp, 0, EV_TIMEOUT);
+
break;
}
- if (tp->t_rxtshift == 1) {
- /*
- * first retransmit; record ssthresh and cwnd so they can
- * be recovered if this turns out to be a "bad" retransmit.
- * A retransmit is considered "bad" if an ACK for this
- * segment is received within RTT/2 interval; the assumption
- * here is that the ACK was already in flight. See
- * "On Estimating End-to-End Network Path Properties" by
- * Allman and Paxson for more details.
- */
- tp->snd_cwnd_prev = tp->snd_cwnd;
- tp->snd_ssthresh_prev = tp->snd_ssthresh;
- tp->snd_recover_prev = tp->snd_recover;
- if (IN_FASTRECOVERY(tp))
- tp->t_flags |= TF_WASFRECOVERY;
- else
- tp->t_flags &= ~TF_WASFRECOVERY;
- tp->t_badrxtwin = tcp_now + (tp->t_srtt >> (TCP_RTT_SHIFT));
+ tcpstat.tcps_rexmttimeo++;
- /* Set the time at which retransmission on this
- * connection started
- */
- tp->rxt_start = tcp_now;
+ if (tp->t_rxtshift == 1 &&
+ tp->t_state == TCPS_ESTABLISHED) {
+ /* Set the time at which retransmission started. */
+ tp->t_rxtstart = tcp_now;
+
+ /*
+ * if this is the first retransmit timeout, save
+ * the state so that we can recover if the timeout
+ * is spurious.
+ */
+ tcp_rexmt_save_state(tp);
}
- tcpstat.tcps_rexmttimeo++;
- if (tp->t_state == TCPS_SYN_SENT)
+#if MPTCP
+ if ((tp->t_rxtshift == mptcp_fail_thresh) &&
+ (tp->t_state == TCPS_ESTABLISHED) &&
+ (tp->t_mpflags & TMPF_MPTCP_TRUE)) {
+ mptcp_act_on_txfail(so);
+
+ }
+#endif /* MPTCP */
+
+ if (tp->t_adaptive_wtimo > 0 &&
+ tp->t_rxtshift > tp->t_adaptive_wtimo &&
+ TCPS_HAVEESTABLISHED(tp->t_state)) {
+ /* Send an event to the application */
+ soevent(so,
+ (SO_FILT_HINT_LOCKED|
+ SO_FILT_HINT_ADAPTIVE_WTIMO));
+ }
+
+ if (tp->t_state == TCPS_SYN_SENT) {
rexmt = TCP_REXMTVAL(tp) * tcp_syn_backoff[tp->t_rxtshift];
+ tp->t_stat.synrxtshift = tp->t_rxtshift;
+ }
else
rexmt = TCP_REXMTVAL(tp) * tcp_backoff[tp->t_rxtshift];
TCPT_RANGESET(tp->t_rxtcur, rexmt,
TCP_ADD_REXMTSLOP(tp));
tp->t_timer[TCPT_REXMT] = OFFSET_FROM_START(tp, tp->t_rxtcur);
+ if (INP_WAIT_FOR_IF_FEEDBACK(tp->t_inpcb))
+ goto fc_output;
+
+ tcp_free_sackholes(tp);
/*
* Check for potential Path MTU Discovery Black Hole
*/
if (tcp_pmtud_black_hole_detect && (tp->t_state == TCPS_ESTABLISHED)) {
- if (((tp->t_flags & (TF_PMTUD|TF_MAXSEGSNT)) == (TF_PMTUD|TF_MAXSEGSNT)) && (tp->t_rxtshift == 2)) {
+ if (((tp->t_flags & (TF_PMTUD|TF_MAXSEGSNT)) == (TF_PMTUD|TF_MAXSEGSNT)) &&
+ (tp->t_rxtshift == 2)) {
/*
* Enter Path MTU Black-hole Detection mechanism:
* - Disable Path MTU Discovery (IP "DF" bit).
* - Reduce MTU to lower value than what we negociated with peer.
*/
-
- tp->t_flags &= ~TF_PMTUD; /* Disable Path MTU Discovery for now */
- tp->t_flags |= TF_BLACKHOLE; /* Record that we may have found a black hole */
+ /* Disable Path MTU Discovery for now */
+ tp->t_flags &= ~TF_PMTUD;
+ /* Record that we may have found a black hole */
+ tp->t_flags |= TF_BLACKHOLE;
optlen = tp->t_maxopd - tp->t_maxseg;
- tp->t_pmtud_saved_maxopd = tp->t_maxopd; /* Keep track of previous MSS */
- if (tp->t_maxopd > tcp_pmtud_black_hole_mss)
- tp->t_maxopd = tcp_pmtud_black_hole_mss; /* Reduce the MSS to intermediary value */
- else {
+ /* Keep track of previous MSS */
+ tp->t_pmtud_saved_maxopd = tp->t_maxopd;
+ /* Reduce the MSS to intermediary value */
+ if (tp->t_maxopd > tcp_pmtud_black_hole_mss) {
+ tp->t_maxopd = tcp_pmtud_black_hole_mss;
+ } else {
tp->t_maxopd = /* use the default MSS */
#if INET6
isipv6 ? tcp_v6mssdflt :
tp->t_maxseg = tp->t_maxopd - optlen;
/*
- * Reset the slow-start flight size as it may depends on the new MSS
+ * Reset the slow-start flight size
+ * as it may depend on the new MSS
*/
if (CC_ALGO(tp)->cwnd_init != NULL)
CC_ALGO(tp)->cwnd_init(tp);
tp->t_maxopd = tp->t_pmtud_saved_maxopd;
tp->t_maxseg = tp->t_maxopd - optlen;
/*
- * Reset the slow-start flight size as it may depends on the new MSS
- */
+ * Reset the slow-start flight size as it
+ * may depend on the new MSS
+ */
if (CC_ALGO(tp)->cwnd_init != NULL)
CC_ALGO(tp)->cwnd_init(tp);
}
* broken terminal servers (most of which have hopefully been
* retired) that have bad VJ header compression code which
* trashes TCP segments containing unknown-to-them TCP options.
+ * Do this only on non-local connections.
*/
- if ((tp->t_state == TCPS_SYN_SENT) &&
- (tp->t_rxtshift == tcp_broken_peer_syn_rxmit_thres))
+ if (tp->t_state == TCPS_SYN_SENT &&
+ ((!(tp->t_flags & TF_LOCAL) &&
+ tp->t_rxtshift == tcp_broken_peer_syn_rxmit_thres) ||
+ ((tp->t_flags & TF_LOCAL) &&
+ tp->t_rxtshift == tcp_broken_peer_syn_rxmit_thres_local)))
tp->t_flags &= ~(TF_REQ_SCALE|TF_REQ_TSTMP|TF_REQ_CC);
+
/*
* If losing, let the lower level know and try for
* a better route. Also, if we backed off this far,
*/
tp->t_rtttime = 0;
- if (CC_ALGO(tp)->after_timeout != NULL)
+ EXIT_FASTRECOVERY(tp);
+
+ /* RFC 5681 says: when a TCP sender detects segment loss
+ * using retransmit timer and the given segment has already
+ * been retransmitted by way of the retransmission timer at
+ * least once, the value of ssthresh is held constant
+ */
+ if (tp->t_rxtshift == 1 &&
+ CC_ALGO(tp)->after_timeout != NULL)
CC_ALGO(tp)->after_timeout(tp);
- tp->t_dupacks = 0;
- EXIT_FASTRECOVERY(tp);
+ /* CWR notifications are to be sent on new data right after
+ * RTOs, Fast Retransmits and ECE notification receipts.
+ */
+ if ((tp->ecn_flags & TE_ECN_ON) == TE_ECN_ON) {
+ tp->ecn_flags |= TE_SENDCWR;
+ }
+fc_output:
DTRACE_TCP5(cc, void, NULL, struct inpcb *, tp->t_inpcb,
struct tcpcb *, tp, struct tcphdr *, NULL,
int32_t, TCP_CC_REXMT_TIMEOUT);
if ((tp->t_rxtshift == TCP_MAXRXTSHIFT &&
(idle_time >= tcp_maxpersistidle ||
idle_time >= TCP_REXMTVAL(tp) * tcp_totbackoff)) ||
- ((tp->t_persist_stop != 0) && (tp->t_persist_stop <= tcp_now))) {
+ ((tp->t_persist_stop != 0) &&
+ TSTMP_LEQ(tp->t_persist_stop, tcp_now))) {
tcpstat.tcps_persistdrop++;
- so_tmp = tp->t_inpcb->inp_socket;
+ postevent(so, 0, EV_TIMEOUT);
+ soevent(so,
+ (SO_FILT_HINT_LOCKED|SO_FILT_HINT_TIMEOUT));
tp = tcp_drop(tp, ETIMEDOUT);
- postevent(so_tmp, 0, EV_TIMEOUT);
break;
}
tcp_setpersist(tp);
*/
case TCPT_KEEP:
tcpstat.tcps_keeptimeo++;
+#if MPTCP
+ /*
+ * Regular TCP connections do not send keepalives after closing
+ * MPTCP must not also, after sending Data FINs.
+ */
+ struct mptcb *mp_tp = tp->t_mptcb;
+ if ((tp->t_mpflags & TMPF_MPTCP_TRUE) &&
+ (mp_tp == NULL)) {
+ goto dropit;
+ } else if (mp_tp != NULL) {
+ if ((mptcp_ok_to_keepalive(mp_tp) == 0))
+ goto dropit;
+ }
+#endif /* MPTCP */
if (tp->t_state < TCPS_ESTABLISHED)
goto dropit;
if ((always_keepalive ||
- tp->t_inpcb->inp_socket->so_options & SO_KEEPALIVE) &&
+ (tp->t_inpcb->inp_socket->so_options & SO_KEEPALIVE) ||
+ (tp->t_flagsext & TF_DETECT_READSTALL)) &&
(tp->t_state <= TCPS_CLOSING || tp->t_state == TCPS_FIN_WAIT_2)) {
- if (idle_time >= TCP_KEEPIDLE(tp) + (u_int32_t)tcp_maxidle)
+ if (idle_time >= TCP_CONN_KEEPIDLE(tp) + TCP_CONN_MAXIDLE(tp))
goto dropit;
/*
* Send a packet designed to force a response
unsigned int ifscope, nocell = 0;
if (tp->t_inpcb->inp_flags & INP_BOUND_IF)
- ifscope = tp->t_inpcb->inp_boundif;
+ ifscope = tp->t_inpcb->inp_boundifp->if_index;
else
ifscope = IFSCOPE_NONE;
tp->rcv_nxt, tp->snd_una - 1, 0, ifscope,
nocell);
(void) m_free(dtom(t_template));
+ if (tp->t_flagsext & TF_DETECT_READSTALL)
+ tp->t_rtimo_probes++;
}
- tp->t_timer[TCPT_KEEP] = OFFSET_FROM_START(tp, tcp_keepintvl);
- } else
- tp->t_timer[TCPT_KEEP] = OFFSET_FROM_START(tp, TCP_KEEPIDLE(tp));
+ tp->t_timer[TCPT_KEEP] = OFFSET_FROM_START(tp,
+ TCP_CONN_KEEPINTVL(tp));
+ } else {
+ tp->t_timer[TCPT_KEEP] = OFFSET_FROM_START(tp,
+ TCP_CONN_KEEPIDLE(tp));
+ }
+ if (tp->t_flagsext & TF_DETECT_READSTALL) {
+ /*
+ * The keep alive packets sent to detect a read
+ * stall did not get a response from the
+ * peer. Generate more keep-alives to confirm this.
+ * If the number of probes sent reaches the limit,
+ * generate an event.
+ */
+ if (tp->t_rtimo_probes > tp->t_adaptive_rtimo) {
+ /* Generate an event */
+ soevent(so,
+ (SO_FILT_HINT_LOCKED|
+ SO_FILT_HINT_ADAPTIVE_RTIMO));
+ tcp_keepalive_reset(tp);
+ } else {
+ tp->t_timer[TCPT_KEEP] = OFFSET_FROM_START(
+ tp, TCP_REXMTVAL(tp));
+ }
+ }
break;
case TCPT_DELACK:
if (tcp_delack_enabled && (tp->t_flags & TF_DELACK)) {
tp->t_timer[TCPT_DELACK] = 0;
tp->t_flags |= TF_ACKNOW;
- /* If delayed ack timer fired while we are stretching acks,
+ /* If delayed ack timer fired while stretching acks
* go back to acking every other packet
*/
if ((tp->t_flags & TF_STRETCHACK) != 0)
tcp_reset_stretch_ack(tp);
+ /* If we are measuring inter packet arrival jitter for
+ * throttling a connection, this delayed ack might be
+ * the reason for accumulating some jitter. So let's
+ * restart the measurement.
+ */
+ CLEAR_IAJ_STATE(tp);
+
tcpstat.tcps_delack++;
(void) tcp_output(tp);
}
break;
+#if MPTCP
+ case TCPT_JACK_RXMT:
+ if ((tp->t_state == TCPS_ESTABLISHED) &&
+ (tp->t_mpflags & TMPF_PREESTABLISHED) &&
+ (tp->t_mpflags & TMPF_JOINED_FLOW)) {
+ if (++tp->t_mprxtshift > TCP_MAXRXTSHIFT) {
+ tcpstat.tcps_timeoutdrop++;
+ postevent(so, 0, EV_TIMEOUT);
+ soevent(so,
+ (SO_FILT_HINT_LOCKED|
+ SO_FILT_HINT_TIMEOUT));
+ tp = tcp_drop(tp, tp->t_softerror ?
+ tp->t_softerror : ETIMEDOUT);
+ break;
+ }
+ tcpstat.tcps_join_rxmts++;
+ tp->t_flags |= TF_ACKNOW;
+
+ /*
+ * No backoff is implemented for simplicity for this
+ * corner case.
+ */
+ (void) tcp_output(tp);
+ }
+ break;
+#endif /* MPTCP */
+
#if TCPDEBUG
if (tp->t_inpcb->inp_socket->so_options & SO_DEBUG)
tcp_trace(TA_USER, ostate, tp, (void *)0, (struct tcphdr *)0,
#endif
dropit:
tcpstat.tcps_keepdrops++;
+ postevent(so, 0, EV_TIMEOUT);
+ soevent(so,
+ (SO_FILT_HINT_LOCKED|SO_FILT_HINT_TIMEOUT));
tp = tcp_drop(tp, ETIMEDOUT);
- postevent(so_tmp, 0, EV_TIMEOUT);
break;
}
return (tp);
tp->t_flags &= ~(TF_TIMER_ONLIST);
listp->entries--;
- lck_mtx_unlock(listp->mtx);
tp->tentry.le.le_next = NULL;
tp->tentry.le.le_prev = NULL;
+ lck_mtx_unlock(listp->mtx);
}
/* Function to check if the timerlist needs to be rescheduled to run
int32_t diff;
boolean_t is_fast;
- if (runtime == 0 || index == TCPT_NONE)
+ if (index == TCPT_NONE)
return FALSE;
is_fast = !(IS_TIMER_SLOW(index));
/* If the list is being processed then the state of the list is in flux.
* In this case always acquire the lock and set the state correctly.
*/
- if (listp->running) {
+ if (listp->running)
return TRUE;
- }
+
+ if (!listp->scheduled)
+ return (TRUE);
diff = timer_diff(listp->runtime, 0, runtime, 0);
if (diff <= 0) {
lck_mtx_assert(listp->mtx, LCK_MTX_ASSERT_OWNED);
+ offset = min(offset, TCP_TIMERLIST_MAX_OFFSET);
listp->runtime = tcp_now + offset;
+ if (listp->runtime == 0)
+ listp->runtime++;
clock_interval_to_deadline(offset, NSEC_PER_SEC / TCP_RETRANSHZ,
&deadline);
thread_call_enter_delayed(listp->call, deadline);
+ listp->scheduled = TRUE;
}
/* Function to run the timers for a connection.
* with another thread that can cancel or reschedule the timer that is
* about to run. Check if we need to run anything.
*/
- index = tp->tentry.index;
- timer_val = tp->t_timer[index];
-
- if (index == TCPT_NONE || tp->tentry.runtime == 0)
+ if ((index = tp->tentry.index) == TCPT_NONE)
goto done;
+ timer_val = tp->t_timer[index];
diff = timer_diff(tp->tentry.runtime, 0, tcp_now, 0);
if (diff > 0) {
tp->tentry.index = lo_index;
if (lo_index != TCPT_NONE) {
tp->tentry.runtime = tp->tentry.timer_start + tp->t_timer[lo_index];
- } else {
- tp->tentry.runtime = 0;
+ if (tp->tentry.runtime == 0)
+ tp->tentry.runtime++;
}
if (count > 0) {
if (needtorun[i]) {
tp->t_timer[i] = 0;
tp = tcp_timers(tp, i);
- if (tp == NULL)
+ if (tp == NULL) {
+ offset = 0;
+ *(next_index) = TCPT_NONE;
goto done;
+ }
}
}
tcp_set_lotimer_index(tp);
done:
if (tp != NULL && tp->tentry.index == TCPT_NONE) {
tcp_remove_timer(tp);
+ offset = 0;
}
tcp_unlock(so, 1, 0);
return offset;
LIST_FOREACH_SAFE(te, &listp->lhead, le, next_te) {
uint32_t offset = 0;
uint32_t runtime = te->runtime;
- if (TSTMP_GT(runtime, tcp_now)) {
+ if (te->index < TCPT_NONE && TSTMP_GT(runtime, tcp_now)) {
offset = timer_diff(runtime, 0, tcp_now, 0);
if (next_timer == 0 || offset < next_timer) {
next_timer = offset;
tcp_sched_timerlist(next_timer);
} else {
- /* No need to reschedule this timer */
- listp->runtime = 0;
+ /*
+ * No need to reschedule this timer, but always run
+ * periodically at a much higher granularity.
+ */
+ tcp_sched_timerlist(TCP_TIMERLIST_MAX_OFFSET);
}
listp->running = FALSE;
struct tcptimerentry *te = &tp->tentry;
uint16_t index = te->index;
struct tcptimerlist *listp = &tcp_timer_list;
- uint32_t offset = 0;
+ int32_t offset = 0;
boolean_t is_fast;
int list_locked = 0;
}
is_fast = !(IS_TIMER_SLOW(index));
- offset = te->runtime - tcp_now;
- if (offset == 0) {
+ offset = timer_diff(te->runtime, 0, tcp_now, 0);
+ if (offset <= 0) {
offset = 1;
tcp_timer_advanced++;
}
listp->maxentries = listp->entries;
/* if the list is not scheduled, just schedule it */
- if (listp->runtime == 0)
+ if (!listp->scheduled)
goto schedule;
}
if (is_fast) {
listp->pref_mode = TCP_TIMERLIST_FASTMODE;
} else if (listp->pref_offset == 0 ||
- ((int)offset) < listp->pref_offset) {
+ offset < listp->pref_offset) {
listp->pref_offset = offset;
}
} else {
- int32_t diff;
- diff = timer_diff(listp->runtime, 0, tcp_now, offset);
- if (diff <= 0) {
- /* The list is going to run before this timer */
- goto done;
+ /*
+ * The list could have got scheduled while this
+ * thread was waiting for the lock
+ */
+ if (listp->scheduled) {
+ int32_t diff;
+ diff = timer_diff(listp->runtime, 0,
+ tcp_now, offset);
+ if (diff <= 0)
+ goto done;
+ else
+ goto schedule;
} else {
goto schedule;
}
tp->tentry.index = lo_index;
if (lo_index != TCPT_NONE) {
tp->tentry.runtime = tp->tentry.timer_start + tp->t_timer[lo_index];
- } else {
- tp->tentry.runtime = 0;
+ if (tp->tentry.runtime == 0)
+ tp->tentry.runtime++;
}
}
lck_mtx_assert(&tp->t_inpcb->inpcb_mtx, LCK_MTX_ASSERT_OWNED);
+ if (tp->t_inpcb->inp_flags2 & INP2_TIMEWAIT)
+ return;
+
tcp_set_lotimer_index(tp);
tcp_sched_timers(tp);
projects / apple / xnu.git / blobdiff