From: Guus Sliepen <guus@tinc-vpn.org>
Date: Sat, 25 Feb 2012 21:11:30 +0000 (+0100)
Subject: Stricter checks against routing loops.
X-Git-Tag: release-1.0.17~7
X-Git-Url: https://tinc-vpn.org/git/browse?p=tinc;a=commitdiff_plain;h=5140656de6bcfda72951a7827b05414ce306e3ca

Stricter checks against routing loops.

If a packet that had to be sent via an intermediate hop, and that intermediate
hop was the one that sent the packet, we drop it.
---

diff --git a/src/route.c b/src/route.c
index b2e1b7bd..666f48f6 100644
--- a/src/route.c
+++ b/src/route.c
@@ -400,6 +400,11 @@ static void route_ipv4_unicast(node_t *source, vpn_packet_t *packet) {
 		packet->priority = packet->data[15];
 
 	via = (subnet->owner->via == myself) ? subnet->owner->nexthop : subnet->owner->via;
+
+	if(via == source) {
+		ifdebug(TRAFFIC) logger(LOG_ERR, "Routing loop for packet from %s (%s)!", source->name, source->hostname);
+		return;
+	}
 	
 	if(directonly && subnet->owner != via)
 		return route_ipv4_unreachable(source, packet, ICMP_DEST_UNREACH, ICMP_NET_ANO);
@@ -552,6 +557,11 @@ static void route_ipv6_unicast(node_t *source, vpn_packet_t *packet) {
 
 	via = (subnet->owner->via == myself) ? subnet->owner->nexthop : subnet->owner->via;
 	
+	if(via == source) {
+		ifdebug(TRAFFIC) logger(LOG_ERR, "Routing loop for packet from %s (%s)!", source->name, source->hostname);
+		return;
+	}
+	
 	if(directonly && subnet->owner != via)
 		return route_ipv6_unreachable(source, packet, ICMP6_DST_UNREACH, ICMP6_DST_UNREACH_ADMIN);