gentoo-overlay/net-misc/netkit-talk/files/netkit-talk-0.17-ipv6.diff

--- a/talkd/talkd.c
+++ b/talkd/talkd.c
@@ -164,13 +164,14 @@
 	const char *theirip;
 
 	struct hostent *hp;
+	struct sockaddr_in6 addr;
 	struct sockaddr_in sn;
 	int cc, i, ok;
 	socklen_t addrlen;
 
-	addrlen = sizeof(sn);
+	addrlen = sizeof(addr);
 	cc = recvfrom(0, inbuf, sizeof(inbuf), 0,
-		      (struct sockaddr *)&sn, &addrlen);
+		      (struct sockaddr *)&addr, &addrlen);
 	if (cc<0) {
 		if (errno==EINTR || errno==EAGAIN) {
 			return;
@@ -185,14 +186,30 @@
 	 */
 	lastmsgtime = time(NULL);
 
-	if (addrlen!=sizeof(sn)) {
-		syslog(LOG_WARNING, "recvfrom: bogus address length");
-		return;
-	}
-	if (sn.sin_family!=AF_INET) {
+        sn.sin_family = AF_INET;
+	switch (addr.sin6_family)
+	{
+        case AF_INET:
+            sn.sin_addr=((struct sockaddr_in*)&addr)->sin_addr;
+            sn.sin_port=((struct sockaddr_in*)&addr)->sin_port;
+            break;
+	case AF_INET6:
+            // addr must be ::FFFF:x.x.x.x
+            if (addr.sin6_addr.s6_addr32[0]!=0 ||
+                addr.sin6_addr.s6_addr32[1]!=0 ||
+                addr.sin6_addr.s6_addr16[5]!=0xffff ||
+                addr.sin6_addr.s6_addr16[4]!=0)
+            {
+                syslog(LOG_WARNING, "IPv6 address family not supported by talkd");
+                return;
+            }
+            sn.sin_port=addr.sin6_port;
+            sn.sin_addr.s_addr=addr.sin6_addr.s6_addr32[3];
+            break;
+        default:
 		syslog(LOG_WARNING, "recvfrom: bogus address family");
 		return;
-	}
+        }
 
 	/* 
 	 * If we get here we have an address we can reply to, although