X-Git-Url: https://git.subgeniuskitty.com/unix-history/.git/blobdiff_plain/c124e99765d0f6dcbd313a3f51049048be62e9b6..763af25969e565386225b5d855c4c838855a107b:/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 831146f1e5..0b0324a6b0 100644
--- a/usr/src/sys/netinet/tcp_timer.c
+++ b/usr/src/sys/netinet/tcp_timer.c
@@ -1,25 +1,33 @@
-/* tcp_timer.c 4.19 82/03/29 */
+/*
+ * 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 "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/route.h"
-#include "../net/in_pcb.h"
-#include "../net/in_systm.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;
 /*
@@ -30,7 +38,6 @@ tcp_fasttimo()
 	register struct inpcb *inp;
 	register struct tcpcb *tp;
 	int s = splnet();
-COUNT(TCP_FASTTIMO);
 
 	inp = tcb.inp_next;
 	if (inp)
@@ -55,7 +62,6 @@ tcp_slowtimo()
 	register struct tcpcb *tp;
 	int s = splnet();
 	register int i;
-COUNT(TCP_SLOWTIMO);
 
 	/*
 	 * Search through tcb's and update active timers.
@@ -65,16 +71,16 @@ COUNT(TCP_SLOWTIMO);
 		splx(s);
 		return;
 	}
-	while (ip != &tcb) {
+	for (; ip != &tcb; ip = ipnxt) {
+		ipnxt = ip->inp_next;
 		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,
 				    PRU_SLOWTIMO, (struct mbuf *)0,
-				    (caddr_t)i);
+				    (struct mbuf *)i, (struct mbuf *)0);
 				if (ipnxt->inp_prev != ip)
 					goto tpgone;
 			}
@@ -83,9 +89,13 @@ COUNT(TCP_SLOWTIMO);
 		if (tp->t_rtt)
 			tp->t_rtt++;
 tpgone:
-		ip = ipnxt;
+		;
 	}
 	tcp_iss += TCP_ISSINCR/PR_SLOWHZ;		/* increment iss */
+#ifdef TCP_COMPAT_42
+	if ((int)tcp_iss < 0)
+		tcp_iss = 0;				/* XXX */
+#endif
 	splx(s);
 }
 
@@ -97,66 +107,84 @@ tcp_canceltimers(tp)
 {
 	register int i;
 
-COUNT(TCP_CANCELTIMERS);
 	for (i = 0; i < TCPT_NTIMERS; i++)
 		tp->t_timer[i] = 0;
 }
 
-int	tcprexmtprint;
+int	tcp_backoff[TCP_MAXRXTSHIFT+1] =
+    { 1, 2, 4, 6, 8, 10, 15, 20, 30, 30, 30, 30, 30 };
 /*
  * TCP timer processing.
  */
+struct tcpcb *
 tcp_timers(tp, timer)
 	register struct tcpcb *tp;
 	int timer;
 {
+	register int rexmt;
 
-COUNT(TCP_TIMERS);
 	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:
-		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
-	 * 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++;
 		if (tp->t_rxtshift > TCP_MAXRXTSHIFT) {
-			tcp_drop(tp, ETIMEDOUT);
-			return;
+			tp = tcp_drop(tp, ETIMEDOUT);
+			break;
 		}
-		TCPT_RANGESET(tp->t_timer[TCPT_REXMT],
-		    (int)tp->t_srtt, TCPTV_MIN, TCPTV_MAX);
-		TCPT_RANGESET(tp->t_timer[TCPT_REXMT],
-		    tp->t_timer[TCPT_REXMT] << tp->t_rxtshift,
-		    TCPTV_MIN, TCPTV_MAX);
-if (tcprexmtprint)
-printf("rexmt set to %d\n", tp->t_timer[TCPT_REXMT]);
+		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;
-		/* 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);
-		return;
+		break;
 
 	/*
 	 * 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;
-		TCPT_RANGESET(tp->t_timer[TCPT_PERSIST],
-		    tcp_beta * tp->t_srtt, TCPTV_PERSMIN, TCPTV_MAX);
-		return;
+		break;
 
 	/*
 	 * Keep-alive timer went off; send something
@@ -165,7 +193,8 @@ printf("rexmt set to %d\n", tp->t_timer[TCPT_REXMT]);
 	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;
 			/*
@@ -180,25 +209,12 @@ printf("rexmt set to %d\n", tp->t_timer[TCPT_REXMT]);
 			 */
 			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;
-		return;
+		break;
 	dropit:
-		tcp_drop(tp, ETIMEDOUT);
-		return;
-
-#ifdef TCPTRUEOOB
-	/*
-	 * Out-of-band data retransmit timer.
-	 */
-	case TCPT_OOBREXMT:
-		if (tp->t_flags & TF_NOOPT)
-			return;
-		(void) tcp_output(tp);
-		TCPT_RANGESET(tp->t_timer[TCPT_OOBREXMT],
-		    2 * tp->t_srtt, TCPTV_MIN, TCPTV_MAX);
-		return;
-#endif
+		tp = tcp_drop(tp, ETIMEDOUT);
+		break;
 	}
+	return (tp);
 }