libip: skip ipv6 loopback address (thanks mischief)

1 files changed, 19 insertions, 6 deletions

diff --git a/sys/src/libip/myipaddr.c b/sys/src/libip/myipaddr.c
index e1a2773bd..48a099ef6 100644
--- a/sys/src/libip/myipaddr.c
+++ b/sys/src/libip/myipaddr.c
@@ -14,6 +14,12 @@ static uchar loopbackmask[IPaddrlen] = {
 	0xff, 0xff, 0xff, 0xff,
 	0xff, 0, 0, 0
 };
+static uchar loopback6[IPaddrlen] = {
+	0, 0, 0, 0,
+	0, 0, 0, 0,
+	0, 0, 0, 0,
+	0, 0, 0, 1
+};
 
 // find first ip addr that isn't the friggin loopback address
 // unless there are no others
@@ -28,14 +34,21 @@ myipaddr(uchar *ip, char *net)
 	ifc = readipifc(net, ifc, -1);
 	for(nifc = ifc; nifc; nifc = nifc->next)
 		for(lifc = nifc->lifc; lifc; lifc = lifc->next){
+			/* unspecified */
+			if(ipcmp(lifc->ip, IPnoaddr) == 0)
+				continue;
+
+			/* ipv6 loopback */
+			if(ipcmp(lifc->ip, loopback6) == 0)
+				continue;
+
+			/* ipv4 loopback */
 			maskip(lifc->ip, loopbackmask, mynet);
-			if(ipcmp(mynet, loopbacknet) == 0){
+			if(ipcmp(mynet, loopbacknet) == 0)
 				continue;
-			}
-			if(ipcmp(lifc->ip, IPnoaddr) != 0){
-				ipmove(ip, lifc->ip);
-				return 0;
-			}
+
+			ipmove(ip, lifc->ip);
+			return 0;
 		}
 	ipmove(ip, IPnoaddr);
 	return -1;