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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 22e77f1..0b0324a 100644 (file)
--- a/usr/src/sys/netinet/tcp_timer.c
+++ b/usr/src/sys/netinet/tcp_timer.c
@@ -1,32 +1,54 @@
-/* tcp_timer.c 4.6 81/12/12 */
+/*
+ * 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 "param.h"
+#include "systm.h"
+#include "mbuf.h"
+#include "socket.h"
+#include "socketvar.h"
+#include "protosw.h"
+#include "errno.h"
 
 
-#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 "../net/in.h"
-#include "../net/in_pcb.h"
-#include "../net/in_systm.h"
 #include "../net/if.h"
 #include "../net/if.h"
-#include "../net/ip.h"
-#include "../net/ip_var.h"
-#include "../net/tcp.h"
-#include "../net/tcp_fsm.h"
-#include "../net/tcp_seq.h"
-#include "../net/tcp_timer.h"
-#include "../net/tcp_var.h"
-#include "../net/tcpip.h"
-#include "../errno.h"
+#include "../net/route.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;
 /*
  * Fast timeout routine for processing delayed acks
  */
 tcp_fasttimo()
 {
 /*
  * Fast timeout routine for processing delayed acks
  */
 tcp_fasttimo()
 {
+       register struct inpcb *inp;
+       register struct tcpcb *tp;
+       int s = splnet();
 
 
-COUNT(TCP_FASTTIMO);
+       inp = tcb.inp_next;
+       if (inp)
+       for (; inp != &tcb; inp = inp->inp_next)
+               if ((tp = (struct tcpcb *)inp->inp_ppcb) &&
+                   (tp->t_flags & TF_DELACK)) {
+                       tp->t_flags &= ~TF_DELACK;
+                       tp->t_flags |= TF_ACKNOW;
+                       (void) tcp_output(tp);
+               }
+       splx(s);
 }
 
 /*
 }
 
 /*
@@ -36,11 +58,10 @@ COUNT(TCP_FASTTIMO);
  */
 tcp_slowtimo()
 {
  */
 tcp_slowtimo()
 {
-       register struct inpcb *ip;
+       register struct inpcb *ip, *ipnxt;
        register struct tcpcb *tp;
        int s = splnet();
        register int i;
        register struct tcpcb *tp;
        int s = splnet();
        register int i;
-COUNT(TCP_SLOWTIMO);
 
        /*
         * Search through tcb's and update active timers.
 
        /*
         * Search through tcb's and update active timers.
@@ -50,19 +71,31 @@ COUNT(TCP_SLOWTIMO);
                splx(s);
                return;
        }
                splx(s);
                return;
        }
-       for (; ip != &tcb; ip = ip->inp_next) {
+       for (; ip != &tcb; ip = ipnxt) {
+               ipnxt = ip->inp_next;
                tp = intotcpcb(ip);
                tp = intotcpcb(ip);
+               if (tp == 0)
+                       continue;
                for (i = 0; i < TCPT_NTIMERS; i++) {
                for (i = 0; i < TCPT_NTIMERS; i++) {
-                       if (tp->t_timer[i] && --tp->t_timer[i] == 0)
+                       if (tp->t_timer[i] && --tp->t_timer[i] == 0) {
                                (void) tcp_usrreq(tp->t_inpcb->inp_socket,
                                    PRU_SLOWTIMO, (struct mbuf *)0,
                                (void) tcp_usrreq(tp->t_inpcb->inp_socket,
                                    PRU_SLOWTIMO, (struct mbuf *)0,
-                                   (caddr_t)i);
+                                   (struct mbuf *)i, (struct mbuf *)0);
+                               if (ipnxt->inp_prev != ip)
+                                       goto tpgone;
+                       }
                }
                tp->t_idle++;
                if (tp->t_rtt)
                        tp->t_rtt++;
                }
                tp->t_idle++;
                if (tp->t_rtt)
                        tp->t_rtt++;
+tpgone:
+               ;
        }
        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);
 }
 
@@ -74,76 +107,114 @@ tcp_canceltimers(tp)
 {
        register int i;
 
 {
        register int i;
 
-COUNT(TCP_CANCELTIMERS);
-printf("tcp_canceltimers %x\n", tp);
        for (i = 0; i < TCPT_NTIMERS; i++)
                tp->t_timer[i] = 0;
 }
 
        for (i = 0; i < TCPT_NTIMERS; i++)
                tp->t_timer[i] = 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.
  */
+struct tcpcb *
 tcp_timers(tp, timer)
        register struct tcpcb *tp;
        int timer;
 {
 tcp_timers(tp, timer)
        register struct tcpcb *tp;
        int timer;
 {
+       register int rexmt;
 
 
-COUNT(TCP_TIMERS);
-printf("tcp_timers %x %d\n", tp, timer);
        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:
-               tcp_close(tp);
-               return;
+               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
 
        /*
         * 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++;
-               TCPT_RANGESET(tp->t_timer[TCPT_REXMT],
-                   ((int)(2 * tp->t_srtt)) << tp->t_rxtshift,
-                   TCPTV_MIN, TCPTV_MAX);
-printf("rexmt timer now %d\n", tp->t_timer[TCPT_REXMT]);
+               if (tp->t_rxtshift > TCP_MAXRXTSHIFT) {
+                       tp = tcp_drop(tp, ETIMEDOUT);
+                       break;
+               }
+               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);
+               /*
+                * 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);
                (void) tcp_output(tp);
-               return;
+               break;
 
        /*
         * Persistance timer into zero window.
         * Force a byte to be output, if possible.
         */
        case TCPT_PERSIST:
 
        /*
         * Persistance timer into zero window.
         * Force a byte to be output, if possible.
         */
        case TCPT_PERSIST:
+               tcp_setpersist(tp);
                tp->t_force = 1;
                (void) tcp_output(tp);
                tp->t_force = 0;
                tp->t_force = 1;
                (void) tcp_output(tp);
                tp->t_force = 0;
-               TCPT_RANGESET(tp->t_timer[TCPT_PERSIST],
-                   2 * tp->t_srtt, TCPTV_PERSMIN, TCPTV_MAX);
-printf("persist timer now %d\n", tp->t_timer[TCPT_PERSIST]);
-               return;
+               break;
 
        /*
         * Keep-alive timer went off; send something
         * or drop connection if idle for too long.
         */
        case TCPT_KEEP:
 
        /*
         * Keep-alive timer went off; send something
         * or drop connection if idle for too long.
         */
        case TCPT_KEEP:
-               if (tp->t_state < TCPS_ESTABLISHED ||
-                   tp->t_idle >= TCPTV_MAXIDLE) {
-printf("drop because of keep alive\n");
-                       tcp_drop(tp, ETIMEDOUT);
-                       return;
+               if (tp->t_state < TCPS_ESTABLISHED)
+                       goto dropit;
+               if (tp->t_inpcb->inp_socket->so_options & SO_KEEPALIVE &&
+                   tp->t_state <= TCPS_CLOSE_WAIT) {
+                       if (tp->t_idle >= TCPTV_MAXIDLE)
+                               goto dropit;
+                       /*
+                        * Saying tp->rcv_nxt-1 lies about what
+                        * we have received, and by the protocol spec
+                        * requires the correspondent TCP to respond.
+                        * Saying tp->snd_una-1 causes the transmitted
+                        * byte to lie outside the receive window; this
+                        * is important because we don't necessarily
+                        * have a byte in the window to send (consider
+                        * a one-way stream!)
+                        */
+                       tcp_respond(tp,
+                           tp->t_template, tp->rcv_nxt-1, tp->snd_una-1, 0);
                }
                }
-printf("send keep alive\n");
-               tcp_respond(tp->t_template, tp->rcv_nxt, tp->snd_una-1, 0);
                tp->t_timer[TCPT_KEEP] = TCPTV_KEEP;
                tp->t_timer[TCPT_KEEP] = TCPTV_KEEP;
-               return;
+               break;
+       dropit:
+               tp = tcp_drop(tp, ETIMEDOUT);
+               break;
        }
        }
+       return (tp);
 }
 }
Continuous source code history from original PDP-7 UNIX to FreeBSD 2, the first fully unencumbered FreeBSD release.