Plan 9 from Bell Labs 2012-10-11

sys/src/9/port/devwd.c

@@ -76,8 +76,14 @@ wdautostart(void)
 {
 	if (wdautopet || !wd || !wdallowed())
 		return;
-	iprint("watchdog: on with clock strokes\n");
+	if (waserror()) {
+		iprint("watchdog: enable failed\n");
+		return;
+	}
 	wd->enable();
+	poperror();
+
+	iprint("watchdog: on with clock strokes\n");
 	wdautopet = watchdogon = 1;
 	if (!wdclock0called) {
 		addclock0link(wdpet, 200);
@@ -200,7 +206,12 @@ wdwrite(Chan* c, void* a, long n, vlong off)
 			*p = 0;
 
 		if(strncmp(a, "enable", n) == 0) {
+			if (waserror()) {
+				iprint("watchdog: enable failed\n");
+				nexterror();
+			}
 			wd->enable();
+			poperror();
 			watchdogon = 1;
 		} else if(strncmp(a, "disable", n) == 0)
 			wdshutdown();

sys/src/cmd/cdfs/buf.c

@@ -40,16 +40,16 @@ bread(Buf *b, void *v, long n, vlong off)
 	/* Refill buffer */
 	if(b->off > off || off >= b->off+b->ndata) {
 		noff = off - off % b->bs;
-		if(vflag)
+		if(vflag > 1)
 			fprint(2, "try refill at %lld...", noff);
 		if((m = b->fn(b, b->data, b->nblock, noff/b->bs)) <= 0) {
 			if (vflag)
-				fprint(2, "failed\n");
+				fprint(2, "read failed: %r\n");
 			return m;
 		}
 		b->ndata = b->bs * m;
 		b->off = noff;
-		if(vflag)
+		if(vflag > 1)
 			fprint(2, "got %ld\n", b->ndata);
 	}
 

sys/src/cmd/ip/6in4.c

@@ -160,7 +160,7 @@ setup(int *v6net, int *tunp)
 	char buf[128], path[64];
 
 	/*
-	 * gain access to IPv6-in-IPv4 packets
+	 * gain access to IPv6-in-IPv4 packets via ipmux
 	 */
 	p = seprint(buf, buf + sizeof buf, "%s/ipmux!proto=%2.2x|%2.2x;dst=%V",
 		net, IP_IPV6PROTO, IP_ICMPV6PROTO, myip + IPv4off);
@@ -269,6 +269,7 @@ main(int argc, char **argv)
 	procargs(argc, argv);
 	setup(&v6net, &tunnel);
 	runtunnel(v6net, tunnel);
+	exits(0);
 }
 
 /*
@@ -317,6 +318,7 @@ ip2tunnel(int in, int out)
 	op = (Iphdr*)buf;
 	op->vihl = IP_VER4 | 5;		/* hdr is 5 longs? */
 	memcpy(op->src, myip + IPv4off, sizeof op->src);
+	op->proto = IP_IPV6PROTO;	/* inner protocol */
 	op->ttl = 100;
 
 	/* get a V6 packet destined for the tunnel */
@@ -334,16 +336,20 @@ ip2tunnel(int in, int out)
 			n = m;
 
 		/* drop if v6 source or destination address is naughty */
-		if (badipv6(ip->src) ||
-		    (!equivip6(ip->dst, remote6) && badipv6(ip->dst))) {
-			syslog(0, "6in4", "egress filtered %I -> %I",
+		if (badipv6(ip->src)) {
+			syslog(0, "6in4", "egress filtered %I -> %I; bad src",
 				ip->src, ip->dst);
 			continue;
 		}
+		if ((!equivip6(ip->dst, remote6) && badipv6(ip->dst))) {
+			syslog(0, "6in4", "egress filtered %I -> %I; "
+				"bad dst not remote", ip->src, ip->dst);
+			continue;
+		}
 
-		op->proto = ip->proto;
 		if (debug > 1)
 			fprint(2, "v6 to tunnel %I -> %I\n", ip->src, ip->dst);
+
 		/* send 6to4 packets directly to ipv4 target */
 		if ((ip->dst[0]<<8 | ip->dst[1]) == V6to4pfx)
 			memcpy(op->dst, ip->dst+2, sizeof op->dst);
@@ -389,8 +395,12 @@ tunnel2ip(int in, int out)
 
 		/* if not IPv4 nor IPv4 protocol IPv6 nor ICMPv6, drop it */
 		if ((ip->vihl & 0xF0) != IP_VER4 ||
-		    ip->proto != IP_IPV6PROTO && ip->proto != IP_ICMPV6PROTO)
+		    ip->proto != IP_IPV6PROTO && ip->proto != IP_ICMPV6PROTO) {
+			syslog(0, "6in4",
+				"dropping pkt from tunnel with inner proto %d",
+				ip->proto);
 			continue;
+		}
 
 		/* check length: drop if too short, trim if too long */
 		m = nhgets(ip->length);
@@ -408,8 +418,8 @@ tunnel2ip(int in, int out)
 		 */
 		maskip(op->dst, localmask, a);
 		if (!equivip6(a, localnet)) {
-			syslog(0, "6in4", "ingress filtered %I -> %I",
-				op->src, op->dst);
+			syslog(0, "6in4", "ingress filtered %I -> %I; "
+				"dst not on local net", op->src, op->dst);
 			continue;
 		}
 		if (debug > 1)