From 75570562e8ae0e62b8fc00be75f9aa4108e2e246 Mon Sep 17 00:00:00 2001
From: David du Colombier <0intro@gmail.com>
Date: Thu, 4 Sep 1997 00:00:00 +0000
Subject: [PATCH] Plan 9 from Bell Labs 1997-09-04

---
 ip/icmp.c | 36 ++++++++++++++++++++++++++++++------
 ip/udp.c  | 13 ++++++++++---
 2 files changed, 40 insertions(+), 9 deletions(-)

diff --git a/ip/icmp.c b/ip/icmp.c
index 57c25fb3a84e6cc6a34168182300660751bc4014..0708aa16cf5222e81d6b665b3a38a72548ecf68d 100644
--- a/ip/icmp.c
+++ b/ip/icmp.c
@@ -118,7 +118,7 @@ icmpkick(Conv *c, int l)
 	hnputs(p->icmpid, c->lport);
 	memset(p->cksum, 0, sizeof(p->cksum));
 	hnputs(p->cksum, ptclcsum(bp, ICMP_IPSIZE, blocklen(bp) - ICMP_IPSIZE));
-	ipoput(bp, 0, MAXTTL);
+	ipoput(bp, 0, c->ttl);
 }
 
 extern void
@@ -136,10 +136,11 @@ icmpnoconv(Block *bp)
 	memmove(np->data, bp->rp, ICMP_IPSIZE + 8);
 	np->type = Unreachable;
 	np->code = 3;
-	p->proto = IP_ICMPPROTO;
-	hnputs(p->icmpid, 0);
-	memset(p->cksum, 0, sizeof(p->cksum));
-	hnputs(p->cksum, ptclcsum(bp, ICMP_IPSIZE, blocklen(bp) - ICMP_IPSIZE));
+	np->proto = IP_ICMPPROTO;
+	hnputs(np->icmpid, 0);
+	hnputs(np->seq, 0);
+	memset(np->cksum, 0, sizeof(np->cksum));
+	hnputs(np->cksum, ptclcsum(nbp, ICMP_IPSIZE, blocklen(nbp) - ICMP_IPSIZE));
 	ipoput(nbp, 0, MAXTTL);
 }
 
@@ -275,6 +276,29 @@ raise:
 	freeblist(bp);
 }
 
+void
+icmpadvise(Block *bp, char *msg)
+{
+	Conv	**c, *s;
+	Icmp	*p;
+	Ipaddr	dst;
+	ushort	recid;
+
+	p = (Icmp *) bp->rp;
+	dst = nhgetl(p->dst);
+	recid = nhgets(p->icmpid);
+
+	for(c = icmp.conv; *c; c++) {
+		s = *c;
+		if(s->lport == recid && s->raddr == dst){
+			qhangup(s->rq, msg);
+			qhangup(s->wq, msg);
+			break;
+		}
+	}
+	freeblist(bp);
+}
+
 void
 icmpinit(Fs *fs)
 {
@@ -287,7 +311,7 @@ icmpinit(Fs *fs)
 	icmp.close = icmpclose;
 	icmp.rcv = icmpiput;
 	icmp.ctl = nil;
-	icmp.advise = nil;
+	icmp.advise = icmpadvise;
 	icmp.ipproto = IP_ICMPPROTO;
 	icmp.nc = 16;
 	icmp.ptclsize = 0;
diff --git a/ip/udp.c b/ip/udp.c
index ae23a86bcc6e09c29f4034e8998a7aa08443149c..57e34a1485efb2dfc341034027c78c4a494c2371 100644
--- a/ip/udp.c
+++ b/ip/udp.c
@@ -198,7 +198,7 @@ udpkick(Conv *c, int l)
 void
 udpiput(Media *m, Block *bp)
 {
-	int len;
+	int len, olen, ottl;
 	Udphdr *uh;
 	Conv *c, **p;
 	Udpcb *ucb;
@@ -210,9 +210,11 @@ udpiput(Media *m, Block *bp)
 	USED(m);
 	uh = (Udphdr*)(bp->rp);
 
-	/* Put back pseudo header for checksum */
+	/* Put back pseudo header for checksum (remember old values for icmpnoconv()) */
+	ottl = uh->Unused;
 	uh->Unused = 0;
 	len = nhgets(uh->udplen);
+	olen = nhgets(uh->udpplen);
 	hnputs(uh->udpplen, len);
 
 	raddr = nhgetl(uh->udpsrc);
@@ -244,7 +246,12 @@ udpiput(Media *m, Block *bp)
 	if(*p == nil) {
 		netlog(Logudp, "udp: no conv %I.%d -> %I.%d\n", src, rport,
 			dst, lport);
-		icmpnoconv(bp);
+		/* don't complain about broadcasts... */
+		if(Mediaforme(dst) > 0){
+			uh->Unused = ottl;
+			hnputs(uh->udpplen, olen);
+			icmpnoconv(bp);
+		}
 		freeblist(bp);
 		return;
 	}