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can't reset it if not set up
[unix-history] / usr / src / sys / netinet / tcp_timer.c
diff --git a/usr/src/sys/netinet/tcp_timer.c b/usr/src/sys/netinet/tcp_timer.c
index c604849..0b0324a 100644 (file)
--- a/usr/src/sys/netinet/tcp_timer.c
+++ b/usr/src/sys/netinet/tcp_timer.c
@@ -1,27 +1,33 @@
-/*     tcp_timer.c     6.1     83/07/29        */
+/*
+ * Copyright (c) 1982, 1986 Regents of the University of California.
+ * All rights reserved.  The Berkeley software License Agreement
+ * specifies the terms and conditions for redistribution.
+ *
+ *     @(#)tcp_timer.c 7.1 (Berkeley) %G%
+ */
 
 
-#include "../h/param.h"
-#include "../h/systm.h"
-#include "../h/mbuf.h"
-#include "../h/socket.h"
-#include "../h/socketvar.h"
-#include "../h/protosw.h"
-#include "../h/errno.h"
+#include "param.h"
+#include "systm.h"
+#include "mbuf.h"
+#include "socket.h"
+#include "socketvar.h"
+#include "protosw.h"
+#include "errno.h"
 
 #include "../net/if.h"
 #include "../net/route.h"
 
 
 #include "../net/if.h"
 #include "../net/route.h"
 
-#include "../netinet/in.h"
-#include "../netinet/in_pcb.h"
-#include "../netinet/in_systm.h"
-#include "../netinet/ip.h"
-#include "../netinet/ip_var.h"
-#include "../netinet/tcp.h"
-#include "../netinet/tcp_fsm.h"
-#include "../netinet/tcp_seq.h"
-#include "../netinet/tcp_timer.h"
-#include "../netinet/tcp_var.h"
-#include "../netinet/tcpip.h"
+#include "in.h"
+#include "in_pcb.h"
+#include "in_systm.h"
+#include "ip.h"
+#include "ip_var.h"
+#include "tcp.h"
+#include "tcp_fsm.h"
+#include "tcp_seq.h"
+#include "tcp_timer.h"
+#include "tcp_var.h"
+#include "tcpip.h"
 
 int    tcpnodelack = 0;
 /*
 
 int    tcpnodelack = 0;
 /*
@@ -65,11 +71,11 @@ tcp_slowtimo()
                splx(s);
                return;
        }
                splx(s);
                return;
        }
-       while (ip != &tcb) {
+       for (; ip != &tcb; ip = ipnxt) {
+               ipnxt = ip->inp_next;
                tp = intotcpcb(ip);
                if (tp == 0)
                        continue;
                tp = intotcpcb(ip);
                if (tp == 0)
                        continue;
-               ipnxt = ip->inp_next;
                for (i = 0; i < TCPT_NTIMERS; i++) {
                        if (tp->t_timer[i] && --tp->t_timer[i] == 0) {
                                (void) tcp_usrreq(tp->t_inpcb->inp_socket,
                for (i = 0; i < TCPT_NTIMERS; i++) {
                        if (tp->t_timer[i] && --tp->t_timer[i] == 0) {
                                (void) tcp_usrreq(tp->t_inpcb->inp_socket,
@@ -83,9 +89,13 @@ tcp_slowtimo()
                if (tp->t_rtt)
                        tp->t_rtt++;
 tpgone:
                if (tp->t_rtt)
                        tp->t_rtt++;
 tpgone:
-               ip = ipnxt;
+               ;
        }
        tcp_iss += TCP_ISSINCR/PR_SLOWHZ;               /* increment iss */
        }
        tcp_iss += TCP_ISSINCR/PR_SLOWHZ;               /* increment iss */
+#ifdef TCP_COMPAT_42
+       if ((int)tcp_iss < 0)
+               tcp_iss = 0;                            /* XXX */
+#endif
        splx(s);
 }
 
        splx(s);
 }
 
@@ -101,9 +111,8 @@ tcp_canceltimers(tp)
                tp->t_timer[i] = 0;
 }
 
                tp->t_timer[i] = 0;
 }
 
-float  tcp_backoff[TCP_MAXRXTSHIFT] =
-    { 1.0, 1.2, 1.4, 1.7, 2.0, 3.0, 5.0, 8.0, 16.0, 32.0 };
-int    tcpexprexmtbackoff = 0;
+int    tcp_backoff[TCP_MAXRXTSHIFT+1] =
+    { 1, 2, 4, 6, 8, 10, 15, 20, 30, 30, 30, 30, 30 };
 /*
  * TCP timer processing.
  */
 /*
  * TCP timer processing.
  */
@@ -112,22 +121,28 @@ tcp_timers(tp, timer)
        register struct tcpcb *tp;
        int timer;
 {
        register struct tcpcb *tp;
        int timer;
 {
+       register int rexmt;
 
        switch (timer) {
 
        /*
 
        switch (timer) {
 
        /*
-        * 2 MSL timeout in shutdown went off.  Delete connection
-        * control block.
+        * 2 MSL timeout in shutdown went off.  If we're closed but
+        * still waiting for peer to close and connection has been idle
+        * too long, or if 2MSL time is up from TIME_WAIT, delete connection
+        * control block.  Otherwise, check again in a bit.
         */
        case TCPT_2MSL:
         */
        case TCPT_2MSL:
-               tp = tcp_close(tp);
+               if (tp->t_state != TCPS_TIME_WAIT &&
+                   tp->t_idle <= TCPTV_MAXIDLE)
+                       tp->t_timer[TCPT_2MSL] = TCPTV_KEEP;
+               else
+                       tp = tcp_close(tp);
                break;
 
        /*
         * Retransmission timer went off.  Message has not
         * been acked within retransmit interval.  Back off
                break;
 
        /*
         * Retransmission timer went off.  Message has not
         * been acked within retransmit interval.  Back off
-        * to a longer retransmit interval and retransmit all
-        * unacknowledged messages in the window.
+        * to a longer retransmit interval and retransmit one segment.
         */
        case TCPT_REXMT:
                tp->t_rxtshift++;
         */
        case TCPT_REXMT:
                tp->t_rxtshift++;
@@ -135,20 +150,28 @@ tcp_timers(tp, timer)
                        tp = tcp_drop(tp, ETIMEDOUT);
                        break;
                }
                        tp = tcp_drop(tp, ETIMEDOUT);
                        break;
                }
-               TCPT_RANGESET(tp->t_timer[TCPT_REXMT],
-                   (int)tp->t_srtt, TCPTV_MIN, TCPTV_MAX);
-               if (tcpexprexmtbackoff) {
-                       TCPT_RANGESET(tp->t_timer[TCPT_REXMT],
-                           tp->t_timer[TCPT_REXMT] << tp->t_rxtshift,
+               if (tp->t_srtt == 0)
+                       rexmt = tcp_beta * TCPTV_SRTTDFLT;
+               else
+                       rexmt = (int)(tcp_beta * tp->t_srtt);
+               rexmt *= tcp_backoff[tp->t_rxtshift - 1];
+               TCPT_RANGESET(tp->t_timer[TCPT_REXMT], rexmt,
                            TCPTV_MIN, TCPTV_MAX);
                            TCPTV_MIN, TCPTV_MAX);
-               } else {
-                       TCPT_RANGESET(tp->t_timer[TCPT_REXMT],
-                           tp->t_timer[TCPT_REXMT] *
-                               tcp_backoff[tp->t_rxtshift - 1],
-                           TCPTV_MIN, TCPTV_MAX);
-               }
+               /*
+                * If losing, let the lower level know
+                * and try for a better route.
+                */
+               if (tp->t_rxtshift >= TCP_MAXRXTSHIFT / 4 ||
+                   rexmt >= 10 * PR_SLOWHZ)
+                       in_losing(tp->t_inpcb);
                tp->snd_nxt = tp->snd_una;
                tp->snd_nxt = tp->snd_una;
-               /* this only transmits one segment! */
+               /*
+                * If timing a segment in this window,
+                * and we have already gotten some timing estimate,
+                * stop the timer.
+                */
+               if (tp->t_rtt && tp->t_srtt)
+                       tp->t_rtt = 0;
                (void) tcp_output(tp);
                break;
 
                (void) tcp_output(tp);
                break;
 
@@ -170,7 +193,8 @@ tcp_timers(tp, timer)
        case TCPT_KEEP:
                if (tp->t_state < TCPS_ESTABLISHED)
                        goto dropit;
        case TCPT_KEEP:
                if (tp->t_state < TCPS_ESTABLISHED)
                        goto dropit;
-               if (tp->t_inpcb->inp_socket->so_options & SO_KEEPALIVE) {
+               if (tp->t_inpcb->inp_socket->so_options & SO_KEEPALIVE &&
+                   tp->t_state <= TCPS_CLOSE_WAIT) {
                        if (tp->t_idle >= TCPTV_MAXIDLE)
                                goto dropit;
                        /*
                        if (tp->t_idle >= TCPTV_MAXIDLE)
                                goto dropit;
                        /*
@@ -185,8 +209,7 @@ tcp_timers(tp, timer)
                         */
                        tcp_respond(tp,
                            tp->t_template, tp->rcv_nxt-1, tp->snd_una-1, 0);
                         */
                        tcp_respond(tp,
                            tp->t_template, tp->rcv_nxt-1, tp->snd_una-1, 0);
-               } else
-                       tp->t_idle = 0;
+               }
                tp->t_timer[TCPT_KEEP] = TCPTV_KEEP;
                break;
        dropit:
                tp->t_timer[TCPT_KEEP] = TCPTV_KEEP;
                break;
        dropit:
Continuous source code history from original PDP-7 UNIX to FreeBSD 2, the first fully unencumbered FreeBSD release.