/*
- * 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 <net/ntstat.h>
#include <netinet/in.h>
#include <netinet/in_systm.h>
#endif
#include <sys/kdebug.h>
#include <mach/sdt.h>
-
-extern void postevent(struct socket *, struct sockbuf *,
- int);
-#define DBG_FNC_TCP_FAST NETDBG_CODE(DBG_NETTCP, (5 << 8))
-#define DBG_FNC_TCP_SLOW NETDBG_CODE(DBG_NETTCP, (5 << 8) | 1)
+#include <netinet/mptcp_var.h>
#define TIMERENTRY_TO_TP(te) ((struct tcpcb *)((uintptr_t)te - offsetof(struct tcpcb, tentry.le.le_next)))
panic("Bad link elm %p prev->next != elm", (elm)); \
} while(0)
-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");
+#define TCP_SET_TIMER_MODE(mode, i) do { \
+ if (IS_TIMER_HZ_10MS(i)) \
+ (mode) |= TCP_TIMERLIST_10MS_MODE; \
+ else if (IS_TIMER_HZ_100MS(i)) \
+ (mode) |= TCP_TIMERLIST_100MS_MODE; \
+ else \
+ (mode) |= TCP_TIMERLIST_500MS_MODE; \
+} while(0)
+
+/* Max number of times a stretch ack can be delayed on a connection */
+#define TCP_STRETCHACK_DELAY_THRESHOLD 5
+
+/* 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
sysctl_msec_to_ticks SYSCTL_HANDLER_ARGS
}
int tcp_keepinit;
-SYSCTL_PROC(_net_inet_tcp, TCPCTL_KEEPINIT, keepinit, CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_LOCKED,
+SYSCTL_PROC(_net_inet_tcp, TCPCTL_KEEPINIT, keepinit,
+ CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_LOCKED,
&tcp_keepinit, 0, sysctl_msec_to_ticks, "I", "");
int tcp_keepidle;
-SYSCTL_PROC(_net_inet_tcp, TCPCTL_KEEPIDLE, keepidle, CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_LOCKED,
+SYSCTL_PROC(_net_inet_tcp, TCPCTL_KEEPIDLE, keepidle,
+ CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_LOCKED,
&tcp_keepidle, 0, sysctl_msec_to_ticks, "I", "");
int tcp_keepintvl;
-SYSCTL_PROC(_net_inet_tcp, TCPCTL_KEEPINTVL, keepintvl, CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_LOCKED,
+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,
+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");
/*
- * Avoid DoS via TCP Robustness in Persist Condition (see http://www.ietf.org/id/draft-ananth-tcpm-persist-02.txt)
- * by allowing a system wide maximum persistence timeout value when in Zero Window Probe mode.
- * Expressed in milliseconds to be consistent without timeout related values, the TCP socket option is in seconds.
+ * Avoid DoS via TCP Robustness in Persist Condition
+ * (see http://www.ietf.org/id/draft-ananth-tcpm-persist-02.txt)
+ * by allowing a system wide maximum persistence timeout value when in
+ * Zero Window Probe mode.
+ *
+ * Expressed in milliseconds to be consistent without timeout related
+ * values, the TCP socket option is in seconds.
*/
u_int32_t tcp_max_persist_timeout = 0;
-SYSCTL_PROC(_net_inet_tcp, OID_AUTO, max_persist_timeout, CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_LOCKED,
- &tcp_max_persist_timeout, 0, sysctl_msec_to_ticks, "I", "Maximum persistence timout for ZWP");
+SYSCTL_PROC(_net_inet_tcp, OID_AUTO, max_persist_timeout,
+ CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_LOCKED,
+ &tcp_max_persist_timeout, 0, sysctl_msec_to_ticks, "I",
+ "Maximum persistence timeout for ZWP");
static int always_keepalive = 0;
-SYSCTL_INT(_net_inet_tcp, OID_AUTO, always_keepalive, CTLFLAG_RW | CTLFLAG_LOCKED,
+SYSCTL_INT(_net_inet_tcp, OID_AUTO, always_keepalive,
+ CTLFLAG_RW | CTLFLAG_LOCKED,
&always_keepalive , 0, "Assume SO_KEEPALIVE on all TCP connections");
-/* This parameter determines how long the timer list will stay in fast mode even
- * though all connections are idle. In fast mode, the timer will fire more frequently
- * anticipating new data.
+/*
+ * This parameter determines how long the timer list will stay in fast or
+ * quick mode even though all connections are idle. In this state, the
+ * timer will run more frequently anticipating new data.
*/
-int timer_fastmode_idlemax = TCP_FASTMODE_IDLEGEN_MAX;
-SYSCTL_INT(_net_inet_tcp, OID_AUTO, timer_fastmode_idlemax, CTLFLAG_RW | CTLFLAG_LOCKED,
- &timer_fastmode_idlemax, 0, "Maximum idle generations in fast mode");
+int timer_fastmode_idlemax = TCP_FASTMODE_IDLERUN_MAX;
+SYSCTL_INT(_net_inet_tcp, OID_AUTO, timer_fastmode_idlemax,
+ CTLFLAG_RW | CTLFLAG_LOCKED,
+ &timer_fastmode_idlemax, 0, "Maximum idle generations in fast mode");
/*
* See tcp_syn_backoff[] for interval values between SYN retransmits;
* two options.
*/
static int tcp_broken_peer_syn_rxmit_thres = 7;
-SYSCTL_INT(_net_inet_tcp, OID_AUTO, broken_peer_syn_rxmit_thres, CTLFLAG_RW | CTLFLAG_LOCKED,
- &tcp_broken_peer_syn_rxmit_thres, 0, "Number of retransmitted SYNs before "
+SYSCTL_INT(_net_inet_tcp, OID_AUTO, broken_peer_syn_rxmit_thres,
+ CTLFLAG_RW | CTLFLAG_LOCKED,
+ &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, tcp_timer_advanced,
+ CTLFLAG_RD | CTLFLAG_LOCKED, &tcp_timer_advanced, 0,
+ "Number of times one of the timers was advanced");
static int tcp_resched_timerlist = 0;
-SYSCTL_INT(_net_inet_tcp, OID_AUTO, tcp_resched_timerlist, CTLFLAG_RD | CTLFLAG_LOCKED,
- &tcp_resched_timerlist, 0,
+SYSCTL_INT(_net_inet_tcp, OID_AUTO, tcp_resched_timerlist,
+ CTLFLAG_RD | CTLFLAG_LOCKED, &tcp_resched_timerlist, 0,
"Number of times timer list was rescheduled as part of processing a packet");
int tcp_pmtud_black_hole_detect = 1 ;
-SYSCTL_INT(_net_inet_tcp, OID_AUTO, pmtud_blackhole_detection, CTLFLAG_RW | CTLFLAG_LOCKED,
- &tcp_pmtud_black_hole_detect, 0, "Path MTU Discovery Black Hole Detection");
+SYSCTL_INT(_net_inet_tcp, OID_AUTO, pmtud_blackhole_detection,
+ CTLFLAG_RW | CTLFLAG_LOCKED, &tcp_pmtud_black_hole_detect, 0,
+ "Path MTU Discovery Black Hole Detection");
int tcp_pmtud_black_hole_mss = 1200 ;
-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");
+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");
+
+/* performed garbage collection of "used" sockets */
+static boolean_t tcp_gc_done = FALSE;
-static int tcp_keepcnt = TCPTV_KEEPCNT;
-static int tcp_gc_done = FALSE; /* perfromed garbage collection of "used" sockets */
- /* max idle probes */
+/* 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
- * between 100 and 200 ms.
+/*
+ * 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 between 100 and 200 ms.
*/
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;
-
-/* The frequency of running through the TCP timer list in
- * fast and slow mode can be configured.
+#if MPTCP
+/*
+ * MP_JOIN retransmission of 3rd ACK will be every 500 msecs without backoff
*/
-SYSCTL_UINT(_net_inet_tcp, OID_AUTO, timer_fastquantum, CTLFLAG_RW | CTLFLAG_LOCKED,
- &tcp_timer_list.fast_quantum, TCP_FASTTIMER_QUANTUM,
- "Frequency of running timer list in fast mode");
-
-SYSCTL_UINT(_net_inet_tcp, OID_AUTO, timer_slowquantum, CTLFLAG_RW | CTLFLAG_LOCKED,
- &tcp_timer_list.slow_quantum, TCP_SLOWTIMER_QUANTUM,
- "Frequency of running timer list in slow mode");
+int tcp_jack_rxmt = TCP_RETRANSHZ / 2;
+#endif /* MPTCP */
static void tcp_remove_timer(struct tcpcb *tp);
static void tcp_sched_timerlist(uint32_t offset);
-static uint32_t tcp_run_conn_timer(struct tcpcb *tp, uint16_t *next_index);
+static u_int32_t tcp_run_conn_timer(struct tcpcb *tp, u_int16_t *mode);
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);
+__private_extern__ void tcp_remove_from_time_wait(struct inpcb *inp);
+__private_extern__ void tcp_report_stats(void);
-/* 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,
- * we take care of wrap around such that the value with the sign bit reset is
- * actually ahead of the other.
+/*
+ * 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, we take care of wrap around such that the value
+ * with the sign bit reset is actually ahead of the other.
*/
-
-static inline int32_t
+inline int32_t
timer_diff(uint32_t t1, uint32_t toff1, uint32_t t2, uint32_t toff2) {
return (int32_t)((t1 + toff1) - (t2 + toff2));
};
+static u_int64_t tcp_last_report_time;
+#define TCP_REPORT_STATS_INTERVAL 345600 /* 4 days, in seconds */
+
/* 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);
-void add_to_time_wait(struct tcpcb *tp, uint32_t delay) ;
-static void tcp_garbage_collect(struct inpcb *, int);
+static void add_to_time_wait_locked(struct tcpcb *tp, uint32_t delay);
+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 (tp->t_inpcb->inp_socket->so_options & SO_NOWAKEFROMSLEEP)
+ socket_post_kev_msg_closed(tp->t_inpcb->inp_socket);
+
+ 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,
+
+ /*
+ * If this tp still happens to be on the timer list,
* take it out
*/
if (TIMER_IS_ON_LIST(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);
- KERNEL_DEBUG(DBG_FNC_TCP_SLOW | DBG_FUNC_START, 0,0,0,0,0);
-
- tcp_maxidle = tcp_keepcnt * tcp_keepintvl;
-
- /* 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);
+}
+
+/*
+ * Revert to the older segment size if there is an indication that PMTU
+ * blackhole detection was not needed.
+ */
+void tcp_pmtud_revert_segment_size(struct tcpcb *tp)
+{
+ int32_t optlen;
+
+ VERIFY(tp->t_pmtud_saved_maxopd > 0);
+ tp->t_flags |= TF_PMTUD;
+ tp->t_flags &= ~TF_BLACKHOLE;
+ optlen = tp->t_maxopd - tp->t_maxseg;
+ tp->t_maxopd = tp->t_pmtud_saved_maxopd;
+ tp->t_maxseg = tp->t_maxopd - optlen;
+ /*
+ * 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_pmtud_start_ts = 0;
+ tcpstat.tcps_pmtudbh_reverted++;
+}
+
/*
* TCP timer processing.
*/
register struct tcpcb *tp;
int timer;
{
- register int rexmt;
- struct socket *so_tmp;
+ int32_t rexmt, optlen = 0, idle_time = 0;
+ struct socket *so;
struct tcptemp *t_template;
- int optlen = 0;
- int idle_time = 0;
-
#if TCPDEBUG
int ostate;
#endif
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
- * the time limit set with TCP_RXT_CONNDROPTIME socket option
- * 3. If TCP_RXT_FINDROP socket option was set and we have already
- * retransmitted the FIN 3 times without receiving an ack
+ /*
+ * 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 the time limit set with TCP_RXT_CONNDROPTIME
+ * socket option
+ * 3. If TCP_RXT_FINDROP socket option was set and
+ * we have already 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_flagsext & TF_RXTFINDROP) != 0 &&
+ (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)) {
-
if ((tp->t_flagsext & TF_RXTFINDROP) != 0) {
tcpstat.tcps_rxtfindrop++;
} else {
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++;
+
+ 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);
+ }
+#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 this is a retransmit timeout after PTO, the PTO
+ * was not effective
+ */
+ if (tp->t_flagsext & TF_SENT_TLPROBE) {
+ tp->t_flagsext &= ~(TF_SENT_TLPROBE);
+ tcpstat.tcps_rto_after_pto++;
+ }
- /* Set the time at which retransmission on this
- * connection started
+ if (tp->t_flagsext & TF_DELAY_RECOVERY) {
+ /*
+ * Retransmit timer fired before entering recovery
+ * on a connection with packet re-ordering. This
+ * suggests that the reordering metrics computed
+ * are not accurate.
*/
- tp->rxt_start = tcp_now;
+ tp->t_reorderwin = 0;
+ tp->t_timer[TCPT_DELAYFR] = 0;
+ tp->t_flagsext &= ~(TF_DELAY_RECOVERY);
}
- tcpstat.tcps_rexmttimeo++;
- if (tp->t_state == TCPS_SYN_SENT)
+
+ if (tp->t_state == TCPS_SYN_SENT) {
rexmt = TCP_REXMTVAL(tp) * tcp_syn_backoff[tp->t_rxtshift];
- else
+ tp->t_stat.synrxtshift = tp->t_rxtshift;
+ } else {
rexmt = TCP_REXMTVAL(tp) * tcp_backoff[tp->t_rxtshift];
+ }
+
TCPT_RANGESET(tp->t_rxtcur, rexmt,
tp->t_rttmin, TCPTV_REXMTMAX,
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
+ * 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 (tcp_pmtud_black_hole_detect &&
+ !(tp->t_flagsext & TF_NOBLACKHOLE_DETECTION) &&
+ (tp->t_state == TCPS_ESTABLISHED)) {
+ 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.
+ * - Reduce MTU to lower value than what we
+ * negotiated with the 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;
+ tp->t_pmtud_start_ts = tcp_now;
+ if (tp->t_pmtud_start_ts == 0)
+ tp->t_pmtud_start_ts++;
+ /* 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);
}
/*
- * If further retransmissions are still unsuccessful with a lowered MTU,
- * maybe this isn't a Black Hole and we restore the previous MSS and
- * blackhole detection flags.
+ * If further retransmissions are still
+ * unsuccessful with a lowered MTU, maybe this
+ * isn't a Black Hole and we restore the previous
+ * MSS and blackhole detection flags.
*/
else {
- if ((tp->t_flags & TF_BLACKHOLE) && (tp->t_rxtshift > 4)) {
- tp->t_flags |= TF_PMTUD;
- tp->t_flags &= ~TF_BLACKHOLE;
- optlen = tp->t_maxopd - tp->t_maxseg;
- 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
- */
- if (CC_ALGO(tp)->cwnd_init != NULL)
- CC_ALGO(tp)->cwnd_init(tp);
+ if ((tp->t_flags & TF_BLACKHOLE) &&
+ (tp->t_rxtshift > 4)) {
+ tcp_pmtud_revert_segment_size(tp);
}
}
}
/*
- * Disable rfc1323 and rfc1644 if we haven't got any response to
- * our SYN (after we reach the threshold) to work-around some
- * 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.
+ * Disable rfc1323 and rfc1644 if we haven't got any
+ * response to our SYN (after we reach the threshold)
+ * to work-around some 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,
* Force a segment to be sent.
*/
tp->t_flags |= TF_ACKNOW;
- /*
- * If timing a segment in this window, stop the timer.
- */
+
+ /* If timing a segment in this window, stop the timer */
tp->t_rtttime = 0;
- if (CC_ALGO(tp)->after_timeout != NULL)
+ if (!IN_FASTRECOVERY(tp) && tp->t_rxtshift == 1)
+ tcpstat.tcps_tailloss_rto++;
+
+
+ /*
+ * 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);
- DTRACE_TCP5(cc, void, NULL, struct inpcb *, tp->t_inpcb,
- struct tcpcb *, tp, struct tcphdr *, NULL,
- int32_t, TCP_CC_REXMT_TIMEOUT);
+ /* 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:
+ tcp_ccdbg_trace(tp, NULL, TCP_CC_REXMT_TIMEOUT);
(void) tcp_output(tp);
break;
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);
- tp->t_force = 1;
+ tp->t_flagsext |= TF_FORCE;
(void) tcp_output(tp);
- tp->t_force = 0;
+ tp->t_flagsext &= ~TF_FORCE;
break;
/*
*/
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) &&
+ (tp->t_state > TCPS_ESTABLISHED)) {
+ 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
tcpstat.tcps_keepprobe++;
t_template = tcp_maketemplate(tp);
if (t_template) {
- unsigned int ifscope, nocell = 0;
+ struct inpcb *inp = tp->t_inpcb;
+ struct tcp_respond_args tra;
+ bzero(&tra, sizeof(tra));
+ tra.nocell = INP_NO_CELLULAR(inp);
+ tra.noexpensive = INP_NO_EXPENSIVE(inp);
+ tra.awdl_unrestricted = INP_AWDL_UNRESTRICTED(inp);
if (tp->t_inpcb->inp_flags & INP_BOUND_IF)
- ifscope = tp->t_inpcb->inp_boundif;
+ tra.ifscope = tp->t_inpcb->inp_boundifp->if_index;
else
- ifscope = IFSCOPE_NONE;
-
- /*
- * If the socket isn't allowed to use the
- * cellular interface, indicate it as such.
- */
- if (tp->t_inpcb->inp_flags & INP_NO_IFT_CELLULAR)
- nocell = 1;
-
+ tra.ifscope = IFSCOPE_NONE;
tcp_respond(tp, t_template->tt_ipgen,
&t_template->tt_t, (struct mbuf *)NULL,
- tp->rcv_nxt, tp->snd_una - 1, 0, ifscope,
- nocell);
+ tp->rcv_nxt, tp->snd_una - 1, 0, &tra);
(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_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));
}
- tp->t_timer[TCPT_KEEP] = OFFSET_FROM_START(tp, tcp_keepintvl);
- } else
- tp->t_timer[TCPT_KEEP] = OFFSET_FROM_START(tp, TCP_KEEPIDLE(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,
- * go back to acking every other packet
+ /*
+ * If delayed ack timer fired while stretching
+ * acks, count the number of times the streaming
+ * detection was not correct. If this exceeds a
+ * threshold, disable strech ack on this
+ * connection
+ *
+ * Also, go back to acking every other packet.
*/
- if ((tp->t_flags & TF_STRETCHACK) != 0)
+ if ((tp->t_flags & TF_STRETCHACK)) {
+ if (tp->t_unacksegs > 1 &&
+ tp->t_unacksegs < maxseg_unacked)
+ tp->t_stretchack_delayed++;
+
+ if (tp->t_stretchack_delayed >
+ TCP_STRETCHACK_DELAY_THRESHOLD) {
+ tp->t_flagsext |= TF_DISABLE_STRETCHACK;
+ /*
+ * Note the time at which stretch
+ * ack was disabled automatically
+ */
+ tp->rcv_nostrack_ts = tcp_now;
+ tcpstat.tcps_nostretchack++;
+ tp->t_stretchack_delayed = 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 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
+#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 */
+
+ case TCPT_PTO:
+ {
+ tcp_seq old_snd_nxt;
+ int32_t snd_len;
+ boolean_t rescue_rxt = FALSE;
+
+ tp->t_flagsext &= ~(TF_SENT_TLPROBE);
+
+ /*
+ * Check if the connection is in the right state to
+ * send a probe
+ */
+ if (tp->t_state != TCPS_ESTABLISHED ||
+ tp->t_rxtshift > 0 || tp->snd_max == tp->snd_una ||
+ !SACK_ENABLED(tp) || TAILQ_EMPTY(&tp->snd_holes) ||
+ (IN_FASTRECOVERY(tp) &&
+ (SEQ_GEQ(tp->snd_fack, tp->snd_recover) ||
+ SEQ_GT(tp->snd_nxt, tp->sack_newdata))))
+ break;
+
+ tcpstat.tcps_pto++;
+
+ /* If timing a segment in this window, stop the timer */
+ tp->t_rtttime = 0;
+
+ if (IN_FASTRECOVERY(tp)) {
+ /*
+ * Send a probe to detect tail loss in a
+ * recovery window when the connection is in
+ * fast_recovery.
+ */
+ old_snd_nxt = tp->snd_nxt;
+ rescue_rxt = TRUE;
+ VERIFY(SEQ_GEQ(tp->snd_fack, tp->snd_una));
+ snd_len = min((tp->snd_recover - tp->snd_fack),
+ tp->t_maxseg);
+ tp->snd_nxt = tp->snd_recover - snd_len;
+ tcpstat.tcps_pto_in_recovery++;
+ tcp_ccdbg_trace(tp, NULL, TCP_CC_TLP_IN_FASTRECOVERY);
+ } else {
+ /*
+ * If there is no new data to send or if the
+ * connection is limited by receive window then
+ * retransmit the last segment, otherwise send
+ * new data.
+ */
+ snd_len = min(so->so_snd.sb_cc, tp->snd_wnd)
+ - (tp->snd_max - tp->snd_una);
+ if (snd_len > 0) {
+ tp->snd_nxt = tp->snd_max;
+ } else {
+ snd_len = min((tp->snd_max - tp->snd_una),
+ tp->t_maxseg);
+ tp->snd_nxt = tp->snd_max - snd_len;
+ }
+ }
+
+ /* Note that tail loss probe is being sent */
+ tp->t_flagsext |= TF_SENT_TLPROBE;
+ tp->t_tlpstart = tcp_now;
+
+ tp->snd_cwnd += tp->t_maxseg;
+ (void )tcp_output(tp);
+ tp->snd_cwnd -= tp->t_maxseg;
+
+ tp->t_tlphighrxt = tp->snd_nxt;
+
+ /*
+ * If a tail loss probe was sent after entering recovery,
+ * restore the old snd_nxt value so that other packets
+ * will get retransmitted correctly.
+ */
+ if (rescue_rxt)
+ tp->snd_nxt = old_snd_nxt;
+ break;
+ }
+ case TCPT_DELAYFR:
+ tp->t_flagsext &= ~TF_DELAY_RECOVERY;
+
+ /*
+ * Don't do anything if one of the following is true:
+ * - the connection is already in recovery
+ * - sequence until snd_recover has been acknowledged.
+ * - retransmit timeout has fired
+ */
+ if (IN_FASTRECOVERY(tp) ||
+ SEQ_GEQ(tp->snd_una, tp->snd_recover) ||
+ tp->t_rxtshift > 0)
+ break;
+
+ VERIFY(SACK_ENABLED(tp));
+ if (CC_ALGO(tp)->pre_fr != NULL)
+ CC_ALGO(tp)->pre_fr(tp);
+ ENTER_FASTRECOVERY(tp);
+ if ((tp->ecn_flags & TE_ECN_ON) == TE_ECN_ON)
+ tp->ecn_flags |= TE_SENDCWR;
+
+ tp->t_timer[TCPT_REXMT] = 0;
+ tcpstat.tcps_sack_recovery_episode++;
+ tp->sack_newdata = tp->snd_nxt;
+ tp->snd_cwnd = tp->t_maxseg;
+ tcp_ccdbg_trace(tp, NULL, TCP_CC_ENTER_FASTRECOVERY);
+ (void) tcp_output(tp);
+ break;
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;
}
+#if 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 (tp);
}
lck_mtx_unlock(listp->mtx);
}
-/* Function to check if the timerlist needs to be rescheduled to run
+/*
+ * Function to check if the timerlist needs to be rescheduled to run
* the timer entry correctly. Basically, this is to check if we can avoid
* taking the list lock.
*/
static boolean_t
-need_to_resched_timerlist(uint32_t runtime, uint16_t index) {
+need_to_resched_timerlist(u_int32_t runtime, u_int16_t mode)
+{
struct tcptimerlist *listp = &tcp_timer_list;
int32_t diff;
- boolean_t is_fast;
-
- if (runtime == 0 || 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 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) {
- return TRUE;
- }
+ if (listp->running)
+ return (TRUE);
+
+ if (!listp->scheduled)
+ return (TRUE);
diff = timer_diff(listp->runtime, 0, runtime, 0);
if (diff <= 0) {
/* The list is going to run before this timer */
- return FALSE;
+ return (FALSE);
} else {
- if (is_fast) {
- if (diff <= listp->fast_quantum)
- return FALSE;
+ if (mode & TCP_TIMERLIST_10MS_MODE) {
+ if (diff <= TCP_TIMER_10MS_QUANTUM)
+ return (FALSE);
+ } else if (mode & TCP_TIMERLIST_100MS_MODE) {
+ if (diff <= TCP_TIMER_100MS_QUANTUM)
+ return (FALSE);
} else {
- if (diff <= listp->slow_quantum)
- return FALSE;
+ if (diff <= TCP_TIMER_500MS_QUANTUM)
+ return (FALSE);
}
}
- return TRUE;
+ return (TRUE);
}
void
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++;
+ offset++;
+ }
- clock_interval_to_deadline(offset, NSEC_PER_SEC / TCP_RETRANSHZ,
- &deadline);
+ clock_interval_to_deadline(offset, USEC_PER_SEC, &deadline);
thread_call_enter_delayed(listp->call, deadline);
+ listp->scheduled = TRUE;
}
-/* Function to run the timers for a connection.
+/*
+ * Function to run the timers for a connection.
*
* Returns the offset of next timer to be run for this connection which
* can be used to reschedule the timerlist.
+ *
+ * te_mode is an out parameter that indicates the modes of active
+ * timers for this connection.
*/
-uint32_t
-tcp_run_conn_timer(struct tcpcb *tp, uint16_t *next_index) {
+u_int32_t
+tcp_run_conn_timer(struct tcpcb *tp, u_int16_t *te_mode) {
- struct socket *so;
- uint16_t i = 0, index = TCPT_NONE, lo_index = TCPT_NONE;
- uint32_t timer_val, offset = 0, lo_timer = 0;
+ struct socket *so;
+ u_int16_t i = 0, index = TCPT_NONE, lo_index = TCPT_NONE;
+ u_int32_t timer_val, offset = 0, lo_timer = 0;
int32_t diff;
boolean_t needtorun[TCPT_NTIMERS];
int count = 0;
- VERIFY(tp != NULL);
- bzero(needtorun, sizeof(needtorun));
+ VERIFY(tp != NULL);
+ bzero(needtorun, sizeof(needtorun));
+ *te_mode = 0;
- tcp_lock(tp->t_inpcb->inp_socket, 1, 0);
+ tcp_lock(tp->t_inpcb->inp_socket, 1, 0);
- so = tp->t_inpcb->inp_socket;
+ so = tp->t_inpcb->inp_socket;
/* Release the want count on inp */
- if (in_pcb_checkstate(tp->t_inpcb, WNT_RELEASE, 1) == WNT_STOPUSING) {
+ if (in_pcb_checkstate(tp->t_inpcb, WNT_RELEASE, 1)
+ == WNT_STOPUSING) {
if (TIMER_IS_ON_LIST(tp)) {
tcp_remove_timer(tp);
}
goto done;
}
- /* Since the timer thread needs to wait for tcp lock, it may race
- * 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)
+ /*
+ * Since the timer thread needs to wait for tcp lock, it may race
+ * with another thread that can cancel or reschedule the timer
+ * that is about to run. Check if we need to run anything.
+ */
+ 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) {
if (tp->tentry.index != TCPT_NONE) {
offset = diff;
- *(next_index) = tp->tentry.index;
+ *(te_mode) = tp->tentry.mode;
}
goto done;
}
tp->t_timer[index] = 0;
if (timer_val > 0) {
tp = tcp_timers(tp, index);
- if (tp == NULL)
+ if (tp == NULL)
goto done;
}
- /* Check if there are any other timers that need to be run. While doing it,
- * adjust the timer values wrt tcp_now.
+ /*
+ * Check if there are any other timers that need to be run.
+ * While doing it, adjust the timer values wrt tcp_now.
*/
+ tp->tentry.mode = 0;
for (i = 0; i < TCPT_NTIMERS; ++i) {
if (tp->t_timer[i] != 0) {
- diff = timer_diff(tp->tentry.timer_start, tp->t_timer[i], tcp_now, 0);
+ diff = timer_diff(tp->tentry.timer_start,
+ tp->t_timer[i], tcp_now, 0);
if (diff <= 0) {
- tp->t_timer[i] = 0;
needtorun[i] = TRUE;
count++;
} else {
lo_timer = diff;
lo_index = i;
}
+ TCP_SET_TIMER_MODE(tp->tentry.mode, i);
}
}
}
tp->tentry.timer_start = tcp_now;
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;
+ VERIFY(tp->tentry.index == TCPT_NONE || tp->tentry.mode > 0);
+
+ if (tp->tentry.index != TCPT_NONE) {
+ tp->tentry.runtime = tp->tentry.timer_start +
+ tp->t_timer[tp->tentry.index];
+ if (tp->tentry.runtime == 0)
+ tp->tentry.runtime++;
}
if (count > 0) {
- /* run any other timers that are also outstanding at this time. */
+ /* run any other timers outstanding at this time. */
for (i = 0; i < TCPT_NTIMERS; ++i) {
if (needtorun[i]) {
tp->t_timer[i] = 0;
tp = tcp_timers(tp, i);
- if (tp == NULL)
+ if (tp == NULL) {
+ offset = 0;
+ *(te_mode) = 0;
goto done;
+ }
}
}
tcp_set_lotimer_index(tp);
if (tp->tentry.index < TCPT_NONE) {
offset = tp->t_timer[tp->tentry.index];
- *(next_index) = tp->tentry.index;
+ *(te_mode) = tp->tentry.mode;
}
done:
if (tp != NULL && tp->tentry.index == TCPT_NONE) {
tcp_remove_timer(tp);
+ offset = 0;
}
- tcp_unlock(so, 1, 0);
- return offset;
+
+ tcp_unlock(so, 1, 0);
+ return(offset);
}
void
tcp_run_timerlist(void * arg1, void * arg2) {
-
#pragma unused(arg1, arg2)
-
struct tcptimerentry *te, *next_te;
struct tcptimerlist *listp = &tcp_timer_list;
struct tcpcb *tp;
- uint32_t next_timer = 0;
- uint16_t index = TCPT_NONE;
- boolean_t need_fast = FALSE;
+ uint32_t next_timer = 0; /* offset of the next timer on the list */
+ u_int16_t te_mode = 0; /* modes of all active timers in a tcpcb */
+ u_int16_t list_mode = 0; /* cumulative of modes of all tcpcbs */
uint32_t active_count = 0;
- uint32_t mode = TCP_TIMERLIST_FASTMODE;
calculate_tcp_clock();
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;
}
+ list_mode |= te->mode;
continue;
}
- active_count++;
tp = TIMERENTRY_TO_TP(te);
- /* Acquire an inp wantcnt on the inpcb so that the socket won't get
- * detached even if tcp_close is called
+ /*
+ * Acquire an inp wantcnt on the inpcb so that the socket
+ * won't get detached even if tcp_close is called
*/
- if (in_pcb_checkstate(tp->t_inpcb, WNT_ACQUIRE, 0) == WNT_STOPUSING) {
- /* Some how this pcb went into dead state while on the timer list,
- * just take it off the list. Since the timer list entry pointers
- * are protected by the timer list lock, we can do it here
+ if (in_pcb_checkstate(tp->t_inpcb, WNT_ACQUIRE, 0)
+ == WNT_STOPUSING) {
+ /*
+ * Some how this pcb went into dead state while
+ * on the timer list, just take it off the list.
+ * Since the timer list entry pointers are
+ * protected by the timer list lock, we can
+ * do it here without the socket lock.
*/
if (TIMER_IS_ON_LIST(tp)) {
tp->t_flags &= ~(TF_TIMER_ONLIST);
}
continue;
}
+ active_count++;
- /* Store the next timerentry pointer before releasing the list lock.
- * If that entry has to be removed when we release the lock, this
- * pointer will be updated to the element after that.
+ /*
+ * Store the next timerentry pointer before releasing the
+ * list lock. If that entry has to be removed when we
+ * release the lock, this pointer will be updated to the
+ * element after that.
*/
listp->next_te = next_te;
lck_mtx_unlock(listp->mtx);
- index = TCPT_NONE;
- offset = tcp_run_conn_timer(tp, &index);
+ offset = tcp_run_conn_timer(tp, &te_mode);
lck_mtx_lock(listp->mtx);
next_te = listp->next_te;
listp->next_te = NULL;
- if (offset > 0) {
- if (index < TCPT_NONE) {
- /* Check if this is a fast_timer. */
- if (!need_fast && !(IS_TIMER_SLOW(index))) {
- need_fast = TRUE;
- }
+ if (offset > 0 && te_mode != 0) {
+ list_mode |= te_mode;
- if (next_timer == 0 || offset < next_timer) {
- next_timer = offset;
- }
- }
+ if (next_timer == 0 || offset < next_timer)
+ next_timer = offset;
}
}
if (!LIST_EMPTY(&listp->lhead)) {
- if (listp->mode == TCP_TIMERLIST_FASTMODE) {
- if (need_fast || active_count > 0 ||
- listp->pref_mode == TCP_TIMERLIST_FASTMODE) {
- listp->idlegen = 0;
- } else {
- listp->idlegen++;
- if (listp->idlegen > timer_fastmode_idlemax) {
- mode = TCP_TIMERLIST_SLOWMODE;
- listp->idlegen = 0;
- }
- }
- } else {
- if (!need_fast) {
- mode = TCP_TIMERLIST_SLOWMODE;
- }
- }
+ u_int16_t next_mode = 0;
+ if ((list_mode & TCP_TIMERLIST_10MS_MODE) ||
+ (listp->pref_mode & TCP_TIMERLIST_10MS_MODE))
+ next_mode = TCP_TIMERLIST_10MS_MODE;
+ else if ((list_mode & TCP_TIMERLIST_100MS_MODE) ||
+ (listp->pref_mode & TCP_TIMERLIST_100MS_MODE))
+ next_mode = TCP_TIMERLIST_100MS_MODE;
+ else
+ next_mode = TCP_TIMERLIST_500MS_MODE;
- if (mode == TCP_TIMERLIST_FASTMODE ||
- listp->pref_mode == TCP_TIMERLIST_FASTMODE) {
- next_timer = listp->fast_quantum;
+ if (next_mode != TCP_TIMERLIST_500MS_MODE) {
+ listp->idleruns = 0;
} else {
- if (listp->pref_offset != 0 &&
- listp->pref_offset < next_timer)
- next_timer = listp->pref_offset;
- if (next_timer < listp->slow_quantum)
- next_timer = listp->slow_quantum;
+ /*
+ * the next required mode is slow mode, but if
+ * the last one was a faster mode and we did not
+ * have enough idle runs, repeat the last mode.
+ *
+ * We try to keep the timer list in fast mode for
+ * some idle time in expectation of new data.
+ */
+ if (listp->mode != next_mode &&
+ listp->idleruns < timer_fastmode_idlemax) {
+ listp->idleruns++;
+ next_mode = listp->mode;
+ next_timer = TCP_TIMER_100MS_QUANTUM;
+ } else {
+ listp->idleruns = 0;
+ }
}
+ listp->mode = next_mode;
+ if (listp->pref_offset != 0)
+ next_timer = min(listp->pref_offset, next_timer);
- listp->mode = mode;
+ if (listp->mode == TCP_TIMERLIST_500MS_MODE)
+ next_timer = max(next_timer,
+ TCP_TIMER_500MS_QUANTUM);
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;
lck_mtx_unlock(listp->mtx);
}
-/* Function to verify if a change in timer state is required for a connection */
+/*
+ * Function to check if the timerlist needs to be reschduled to run this
+ * connection's timers correctly.
+ */
void
tcp_sched_timers(struct tcpcb *tp)
{
struct tcptimerentry *te = &tp->tentry;
- uint16_t index = te->index;
+ u_int16_t index = te->index;
+ u_int16_t mode = te->mode;
struct tcptimerlist *listp = &tcp_timer_list;
- uint32_t offset = 0;
- boolean_t is_fast;
- int list_locked = 0;
+ int32_t offset = 0;
+ boolean_t list_locked = FALSE;
if (tp->t_inpcb->inp_state == INPCB_STATE_DEAD) {
/* Just return without adding the dead pcb to the list */
}
if (index == TCPT_NONE) {
+ /* Nothing to run */
tcp_remove_timer(tp);
return;
}
- is_fast = !(IS_TIMER_SLOW(index));
- offset = te->runtime - tcp_now;
- if (offset == 0) {
+ /*
+ * compute the offset at which the next timer for this connection
+ * has to run.
+ */
+ offset = timer_diff(te->runtime, 0, tcp_now, 0);
+ if (offset <= 0) {
offset = 1;
tcp_timer_advanced++;
}
- if (is_fast)
- offset = listp->fast_quantum;
if (!TIMER_IS_ON_LIST(tp)) {
if (!list_locked) {
lck_mtx_lock(listp->mtx);
- list_locked = 1;
+ list_locked = TRUE;
}
LIST_INSERT_HEAD(&listp->lhead, te, le);
tp->t_flags |= TF_TIMER_ONLIST;
- listp->entries++;
- if (listp->entries > listp->maxentries)
- listp->maxentries = listp->entries;
+ listp->entries++;
+ if (listp->entries > listp->maxentries)
+ listp->maxentries = listp->entries;
/* if the list is not scheduled, just schedule it */
- if (listp->runtime == 0)
+ if (!listp->scheduled)
goto schedule;
-
}
- /* timer entry is currently on the list */
- if (need_to_resched_timerlist(te->runtime, index)) {
+ /*
+ * Timer entry is currently on the list, check if the list needs
+ * to be rescheduled.
+ */
+ if (need_to_resched_timerlist(te->runtime, mode)) {
tcp_resched_timerlist++;
if (!list_locked) {
lck_mtx_lock(listp->mtx);
- list_locked = 1;
+ list_locked = TRUE;
}
VERIFY_NEXT_LINK(te, le);
VERIFY_PREV_LINK(te, le);
if (listp->running) {
- if (is_fast) {
- listp->pref_mode = TCP_TIMERLIST_FASTMODE;
- } else if (listp->pref_offset == 0 ||
- ((int)offset) < listp->pref_offset) {
+ listp->pref_mode |= mode;
+ if (listp->pref_offset == 0 ||
+ 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 rescheduled 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;
}
goto done;
schedule:
- if (is_fast) {
- listp->mode = TCP_TIMERLIST_FASTMODE;
- listp->idlegen = 0;
+ /*
+ * Since a connection with timers is getting scheduled, the timer
+ * list moves from idle to active state and that is why idlegen is
+ * reset
+ */
+ if (mode & TCP_TIMERLIST_10MS_MODE) {
+ listp->mode = TCP_TIMERLIST_10MS_MODE;
+ listp->idleruns = 0;
+ offset = min(offset, TCP_TIMER_10MS_QUANTUM);
+ } else if (mode & TCP_TIMERLIST_100MS_MODE) {
+ if (listp->mode > TCP_TIMERLIST_100MS_MODE)
+ listp->mode = TCP_TIMERLIST_100MS_MODE;
+ listp->idleruns = 0;
+ offset = min(offset, TCP_TIMER_100MS_QUANTUM);
}
tcp_sched_timerlist(offset);
return;
}
-void
+static inline void
tcp_set_lotimer_index(struct tcpcb *tp) {
- uint16_t i, lo_index = TCPT_NONE;
+ uint16_t i, lo_index = TCPT_NONE, mode = 0;
uint32_t lo_timer = 0;
for (i = 0; i < TCPT_NTIMERS; ++i) {
- if (tp->t_timer[i] != 0 &&
- (lo_timer == 0 || tp->t_timer[i] < lo_timer)) {
- lo_timer = tp->t_timer[i];
- lo_index = i;
+ if (tp->t_timer[i] != 0) {
+ TCP_SET_TIMER_MODE(mode, i);
+ if (lo_timer == 0 || tp->t_timer[i] < lo_timer) {
+ lo_timer = tp->t_timer[i];
+ lo_index = i;
+ }
}
}
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;
+ tp->tentry.mode = mode;
+ VERIFY(tp->tentry.index == TCPT_NONE || tp->tentry.mode > 0);
+
+ if (tp->tentry.index != TCPT_NONE) {
+ tp->tentry.runtime = tp->tentry.timer_start
+ + tp->t_timer[tp->tentry.index];
+ 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);
return;
}
+
+__private_extern__ void
+tcp_report_stats(void)
+{
+ struct nstat_sysinfo_data data;
+ struct sockaddr_in dst;
+ struct sockaddr_in6 dst6;
+ struct rtentry *rt = NULL;
+ u_int64_t var, uptime;
+
+#define stat data.u.tcp_stats
+ if (((uptime = net_uptime()) - tcp_last_report_time) <
+ TCP_REPORT_STATS_INTERVAL)
+ return;
+
+ tcp_last_report_time = uptime;
+
+ bzero(&data, sizeof(data));
+ data.flags = NSTAT_SYSINFO_TCP_STATS;
+
+ bzero(&dst, sizeof(dst));
+ dst.sin_len = sizeof(dst);
+ dst.sin_family = AF_INET;
+
+ /* ipv4 avg rtt */
+ lck_mtx_lock(rnh_lock);
+ rt = rt_lookup(TRUE, (struct sockaddr *)&dst, NULL,
+ rt_tables[AF_INET], IFSCOPE_NONE);
+ lck_mtx_unlock(rnh_lock);
+ if (rt != NULL) {
+ RT_LOCK(rt);
+ if (rt_primary_default(rt, rt_key(rt)) &&
+ rt->rt_stats != NULL) {
+ stat.ipv4_avgrtt = rt->rt_stats->nstat_avg_rtt;
+ }
+ RT_UNLOCK(rt);
+ rtfree(rt);
+ rt = NULL;
+ }
+
+ /* ipv6 avg rtt */
+ bzero(&dst6, sizeof(dst6));
+ dst6.sin6_len = sizeof(dst6);
+ dst6.sin6_family = AF_INET6;
+
+ lck_mtx_lock(rnh_lock);
+ rt = rt_lookup(TRUE,(struct sockaddr *)&dst6, NULL,
+ rt_tables[AF_INET6], IFSCOPE_NONE);
+ lck_mtx_unlock(rnh_lock);
+ if (rt != NULL) {
+ RT_LOCK(rt);
+ if (rt_primary_default(rt, rt_key(rt)) &&
+ rt->rt_stats != NULL) {
+ stat.ipv6_avgrtt = rt->rt_stats->nstat_avg_rtt;
+ }
+ RT_UNLOCK(rt);
+ rtfree(rt);
+ rt = NULL;
+ }
+
+ /* send packet loss rate, shift by 10 for precision */
+ if (tcpstat.tcps_sndpack > 0 && tcpstat.tcps_sndrexmitpack > 0) {
+ var = tcpstat.tcps_sndrexmitpack << 10;
+ stat.send_plr = (var * 100) / tcpstat.tcps_sndpack;
+ }
+
+ /* recv packet loss rate, shift by 10 for precision */
+ if (tcpstat.tcps_rcvpack > 0 && tcpstat.tcps_recovered_pkts > 0) {
+ var = tcpstat.tcps_recovered_pkts << 10;
+ stat.recv_plr = (var * 100) / tcpstat.tcps_rcvpack;
+ }
+
+ /* RTO after tail loss, shift by 10 for precision */
+ if (tcpstat.tcps_sndrexmitpack > 0
+ && tcpstat.tcps_tailloss_rto > 0) {
+ var = tcpstat.tcps_tailloss_rto << 10;
+ stat.send_tlrto_rate =
+ (var * 100) / tcpstat.tcps_sndrexmitpack;
+ }
+
+ /* packet reordering */
+ if (tcpstat.tcps_sndpack > 0 && tcpstat.tcps_reordered_pkts > 0) {
+ var = tcpstat.tcps_reordered_pkts << 10;
+ stat.send_reorder_rate =
+ (var * 100) / tcpstat.tcps_sndpack;
+ }
+
+ nstat_sysinfo_send_data(&data);
+
+#undef stat
+}
projects / apple / xnu.git / blobdiff