on expiry of pmtu route, retry higher mtu. okay angelos@

6 files changed, 49 insertions, 13 deletions

diff --git a/sys/netinet/ip_icmp.c b/sys/netinet/ip_icmp.c
index 8f3070a5627..a17d58bb09a 100644
--- a/sys/netinet/ip_icmp.c
+++ b/sys/netinet/ip_icmp.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: ip_icmp.c,v 1.24 2000/09/20 19:11:09 angelos Exp $	*/
+/*	$OpenBSD: ip_icmp.c,v 1.25 2000/09/25 09:41:02 provos Exp $	*/
 /*	$NetBSD: ip_icmp.c,v 1.19 1996/02/13 23:42:22 christos Exp $	*/
 
 /*
@@ -817,8 +817,18 @@ icmp_mtudisc_timeout(rt, r)
 		panic("icmp_mtudisc_timeout:  bad route to timeout");
 	if ((rt->rt_flags & (RTF_DYNAMIC | RTF_HOST)) == 
 	    (RTF_DYNAMIC | RTF_HOST)) {
+		void *(*ctlfunc) __P((int, struct sockaddr *, void *));
+		extern u_char ip_protox[];
+		struct sockaddr_in sa;
+
+		sa = *(struct sockaddr_in *)rt_key(rt);
 		rtrequest((int) RTM_DELETE, (struct sockaddr *)rt_key(rt),
 		    rt->rt_gateway, rt_mask(rt), rt->rt_flags, 0);
+
+		/* Notify TCP layer of increased Path MTU estimate */
+		ctlfunc = inetsw[ip_protox[IPPROTO_TCP]].pr_ctlinput;
+		if (ctlfunc)
+			(*ctlfunc)(PRC_MTUINC,(struct sockaddr *)&sa, NULL);
 	} else {
 		if ((rt->rt_rmx.rmx_locks & RTV_MTU) == 0) {
 			rt->rt_rmx.rmx_mtu = 0;
diff --git a/sys/netinet/tcp_input.c b/sys/netinet/tcp_input.c
index afe65c4d4cb..14c135f7ee5 100644
--- a/sys/netinet/tcp_input.c
+++ b/sys/netinet/tcp_input.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: tcp_input.c,v 1.76 2000/09/23 01:07:38 chris Exp $	*/
+/*	$OpenBSD: tcp_input.c,v 1.77 2000/09/25 09:41:02 provos Exp $	*/
 /*	$NetBSD: tcp_input.c,v 1.23 1996/02/13 23:43:44 christos Exp $	*/
 
 /*
@@ -2871,8 +2871,10 @@ tcp_mss(tp, offer)
 	 * unless we received an offer at least that large from peer.
 	 * However, do not accept offers under 32 bytes.
 	 */
-	if (offer && offer != -1)
-		mss = min(mss, offer);
+	if (offer > 0)
+		tp->t_peermss = offer;
+	if (tp->t_peermss)
+		mss = min(mss, tp->t_peermss);
 	mss = max(mss, 64);		/* sanity - at least max opt. space */
 
 	/*
diff --git a/sys/netinet/tcp_output.c b/sys/netinet/tcp_output.c
index f1ab4a5ab05..63d9bd94111 100644
--- a/sys/netinet/tcp_output.c
+++ b/sys/netinet/tcp_output.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: tcp_output.c,v 1.33 2000/09/20 17:00:22 provos Exp $	*/
+/*	$OpenBSD: tcp_output.c,v 1.34 2000/09/25 09:41:03 provos Exp $	*/
 /*	$NetBSD: tcp_output.c,v 1.16 1997/06/03 16:17:09 kml Exp $	*/
 
 /*
@@ -512,8 +512,7 @@ send:
 
 			opt[0] = TCPOPT_MAXSEG;
 			opt[1] = 4;
-			mss = htons((u_int16_t) tcp_mss(tp, flags & TH_ACK ? 
-							tp->t_maxopd : 0));
+			mss = htons((u_int16_t) tcp_mss(tp, 0));
 			bcopy((caddr_t)&mss, (caddr_t)(opt + 2), sizeof(mss));
 			optlen = 4;
 
diff --git a/sys/netinet/tcp_subr.c b/sys/netinet/tcp_subr.c
index c9fa20fb9d6..836bda2197e 100644
--- a/sys/netinet/tcp_subr.c
+++ b/sys/netinet/tcp_subr.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: tcp_subr.c,v 1.32 2000/09/20 17:00:23 provos Exp $	*/
+/*	$OpenBSD: tcp_subr.c,v 1.33 2000/09/25 09:41:03 provos Exp $	*/
 /*	$NetBSD: tcp_subr.c,v 1.22 1996/02/13 23:44:00 christos Exp $	*/
 
 /*
@@ -811,6 +811,8 @@ tcp_ctlinput(cmd, sa, v)
 		notify = in_rtchange, ip = 0;
 	else if (cmd == PRC_MSGSIZE && ip_mtudisc)
 		notify = tcp_mtudisc, ip = 0;
+	else if (cmd == PRC_MTUINC)
+		notify = tcp_mtudisc_increase, ip = 0;
 	else if (cmd == PRC_HOSTDEAD)
 		ip = 0;
 	else if (errno == 0)
@@ -870,7 +872,7 @@ tcp_mtudisc(inp, errno)
 				tcp_mss(tp, -1);
 			}
 		}
-	    
+
 		/*
 		 * Resend unacknowledged packets.
 		 */
@@ -879,6 +881,26 @@ tcp_mtudisc(inp, errno)
 	}
 }
 
+void
+tcp_mtudisc_increase(inp, errno)
+	struct inpcb *inp;
+	int errno;
+{
+	struct tcpcb *tp = intotcpcb(inp);
+	struct rtentry *rt = in_pcbrtentry(inp);
+
+	if (tp != 0 && rt != 0) {
+		/*
+		 * If this was a host route, remove and realloc.
+		 */
+		if (rt->rt_flags & RTF_HOST)
+			in_rtchange(inp, errno);
+		
+		/* also takes care of congestion window */
+		tcp_mss(tp, -1);
+	}
+}
+
 #ifdef TCP_SIGNATURE
 int
 tcp_signature_tdb_attach()
diff --git a/sys/netinet/tcp_var.h b/sys/netinet/tcp_var.h
index 39c03b853d2..f6a2b2989d7 100644
--- a/sys/netinet/tcp_var.h
+++ b/sys/netinet/tcp_var.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: tcp_var.h,v 1.31 2000/09/20 17:00:23 provos Exp $	*/
+/*	$OpenBSD: tcp_var.h,v 1.32 2000/09/25 09:41:03 provos Exp $	*/
 /*	$NetBSD: tcp_var.h,v 1.17 1996/02/13 23:44:24 christos Exp $	*/
 
 /*
@@ -134,7 +134,8 @@ struct tcpcb {
 					 * for slow start exponential to
 					 * linear switch
 					 */
-	u_int	t_maxopd;		/* mss plus options */
+	u_short	t_maxopd;		/* mss plus options */
+	u_short	t_peermss;		/* peer's maximum segment size */
 
 /*
  * transmit timing stuff.  See below for scale of srtt and rttvar.
@@ -345,6 +346,7 @@ void	 tcp_input __P((struct mbuf *, ...));
 int	 tcp_mss __P((struct tcpcb *, int));
 void	 tcp_mss_update __P((struct tcpcb *));
 void	 tcp_mtudisc __P((struct inpcb *, int));
+void	 tcp_mtudisc_increase __P((struct inpcb *, int));
 struct tcpcb *
 	 tcp_newtcpcb __P((struct inpcb *));
 void	 tcp_notify __P((struct inpcb *, int));
diff --git a/sys/sys/protosw.h b/sys/sys/protosw.h
index a39e54a12f5..ebf4cfcfd08 100644
--- a/sys/sys/protosw.h
+++ b/sys/sys/protosw.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: protosw.h,v 1.3 1996/04/21 22:31:54 deraadt Exp $	*/
+/*	$OpenBSD: protosw.h,v 1.4 2000/09/25 09:41:02 provos Exp $	*/
 /*	$NetBSD: protosw.h,v 1.10 1996/04/09 20:55:32 cgd Exp $	*/
 
 /*-
@@ -170,6 +170,7 @@ char *prurequests[] = {
  */
 #define	PRC_IFDOWN		0	/* interface transition */
 #define	PRC_ROUTEDEAD		1	/* select new route if possible ??? */
+#define	PRC_MTUINC		2	/* increase in mtu to host */
 #define	PRC_QUENCH2		3	/* DEC congestion bit says slow down */
 #define	PRC_QUENCH		4	/* some one said to slow down */
 #define	PRC_MSGSIZE		5	/* message size forced drop */
@@ -196,7 +197,7 @@ char *prurequests[] = {
 
 #ifdef PRCREQUESTS
 char	*prcrequests[] = {
-	"IFDOWN", "ROUTEDEAD", "#2", "DEC-BIT-QUENCH2",
+	"IFDOWN", "ROUTEDEAD", "MTUINC", "DEC-BIT-QUENCH2",
 	"QUENCH", "MSGSIZE", "HOSTDEAD", "#7",
 	"NET-UNREACH", "HOST-UNREACH", "PROTO-UNREACH", "PORT-UNREACH",
 	"#12", "SRCFAIL-UNREACH", "NET-REDIRECT", "HOST-REDIRECT",