From: Guus Sliepen <guus@tinc-vpn.org>
Date: Fri, 15 May 2015 21:08:53 +0000 (+0200)
Subject: Be more liberal accepting ADD_EDGE messages with conflicting local address information.
X-Git-Tag: release-1.1pre12~161
X-Git-Url: https://www.tinc-vpn.org/git/browse?p=tinc;a=commitdiff_plain;h=54a8bd78e3fbe2de4d9daea748643f9c9b5b240e

Be more liberal accepting ADD_EDGE messages with conflicting local address information.

If the ADD_EDGE is for one of the edges we own, and if it is not the
same as we actually have, send a correcting ADD_EDGE back. Otherwise, if
the ADD_EDGE contains new information, update our idea of the local
address for that edge.

If the ADD_EDGE does not contain local address information, then we
never make a correction nor log a warning.
---

diff --git a/src/protocol_edge.c b/src/protocol_edge.c
index 43e32364..76e6eb48 100644
--- a/src/protocol_edge.c
+++ b/src/protocol_edge.c
@@ -125,7 +125,7 @@ bool add_edge_h(connection_t *c, const char *request) {
 	e = lookup_edge(from, to);
 
 	if(e) {
-		if(e->weight != weight || e->options != options || sockaddrcmp(&e->address, &address) || sockaddrcmp(&e->local_address, &local_address)) {
+		if(e->weight != weight || e->options != options || sockaddrcmp(&e->address, &address)) {
 			if(from == myself) {
 				logger(DEBUG_PROTOCOL, LOG_WARNING, "Got %s from %s (%s) for ourself which does not match existing entry",
 						   "ADD_EDGE", c->name, c->hostname);
@@ -137,6 +137,28 @@ bool add_edge_h(connection_t *c, const char *request) {
 				edge_del(e);
 				graph();
 			}
+		} else if(sockaddrcmp(&e->local_address, &local_address)) {
+			if(from == myself) {
+				if(e->local_address.sa.sa_family && local_address.sa.sa_family) {
+					// Someone has the wrong local address for ourself. Correct then.
+					logger(DEBUG_PROTOCOL, LOG_WARNING, "Got %s from %s (%s) for ourself which does not match existing entry",
+							   "ADD_EDGE", c->name, c->hostname);
+					send_add_edge(c, e);
+					return true;
+				}
+				// Otherwise, just ignore it.
+				return true;
+			} else if(local_address.sa.sa_family) {
+				// We learned a new local address for this edge.
+				sockaddrfree(&e->local_address);
+				e->local_address = local_address;
+
+				// Tell others about it.
+				if(!tunnelserver)
+					forward_request(c, request);
+
+				return true;
+			}
 		} else
 			return true;
 	} else if(from == myself) {