xnu-2050.9.2.tar.gz

[apple/xnu.git] / bsd / netinet / tcp_timer.c

diff --git a/bsd/netinet/tcp_timer.c b/bsd/netinet/tcp_timer.c
index a8369ca71a164ccd805b78b92a2cd9c6348d4df8..a8df389472f99eb08bf47c24b5ff73bf3b3fb24d 100644 (file)
--- a/bsd/netinet/tcp_timer.c
+++ b/bsd/netinet/tcp_timer.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2000-2011 Apple Inc. All rights reserved.
+ * Copyright (c) 2000-2012 Apple Inc. All rights reserved.
  *
  * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
  * 
@@ -78,6 +78,7 @@
 #include <kern/cpu_number.h>   /* before tcp_seq.h, for tcp_random18() */
 
 #include <net/route.h>
+#include <net/if_var.h>
 
 #include <netinet/in.h>
 #include <netinet/in_systm.h>
@@ -536,7 +537,7 @@ tcp_timers(tp, timer)
        int timer;
 {
        register int rexmt;
-       struct socket *so_tmp;
+       struct socket *so;
        struct tcptemp *t_template;
        int optlen = 0;
        int idle_time = 0;
@@ -549,7 +550,7 @@ tcp_timers(tp, timer)
        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) {
@@ -581,7 +582,6 @@ tcp_timers(tp, timer)
         * 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
@@ -602,9 +602,12 @@ tcp_timers(tp, timer)
                                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;
                }
 
@@ -633,6 +636,7 @@ tcp_timers(tp, timer)
                        tp->rxt_start = tcp_now;
                }
                tcpstat.tcps_rexmttimeo++;
+
                if (tp->t_state == TCPS_SYN_SENT)
                        rexmt = TCP_REXMTVAL(tp) * tcp_syn_backoff[tp->t_rxtshift];
                else
@@ -642,12 +646,17 @@ tcp_timers(tp, timer)
                        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).
@@ -708,6 +717,7 @@ tcp_timers(tp, timer)
                if ((tp->t_state == TCPS_SYN_SENT) &&
                    (tp->t_rxtshift == tcp_broken_peer_syn_rxmit_thres))
                        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,
@@ -747,6 +757,13 @@ tcp_timers(tp, timer)
                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);
@@ -774,11 +791,13 @@ tcp_timers(tp, timer)
                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);
@@ -818,7 +837,7 @@ tcp_timers(tp, timer)
                                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;
 
@@ -851,6 +870,13 @@ tcp_timers(tp, timer)
                        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);
                }
@@ -863,8 +889,10 @@ tcp_timers(tp, timer)
 #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);