From: Guus Sliepen <guus@tinc-vpn.org>
Date: Fri, 30 Mar 2018 09:50:40 +0000 (+0200)
Subject: Prevent an infinite loop in get_recent_address().
X-Git-Tag: release-1.1pre16~6
X-Git-Url: https://www.tinc-vpn.org/git/browse?p=tinc;a=commitdiff_plain;h=63fbaf7b4a33d5657cd3338b7ea91a173b9973fb

Prevent an infinite loop in get_recent_address().

When a node is offline, but we still have edges to it that have the same
address as we already have in our address cache, an infinite loop would
happen in get_recent_address(), because we forgot to advance the pointer
in the list of known addresses, and kept looking at the same one over
and over.

Thanks to Sven-Haegar Koch for spotting the bug and providing
diagnostics.
---

diff --git a/src/address_cache.c b/src/address_cache.c
index 2fa9baff..389615ea 100644
--- a/src/address_cache.c
+++ b/src/address_cache.c
@@ -129,12 +129,12 @@ const sockaddr_t *get_recent_address(address_cache_t *cache) {
 		if(cache->ai) {
 			if(cache->aip) {
 				sockaddr_t *sa = (sockaddr_t *)cache->aip->ai_addr;
+				cache->aip = cache->aip->ai_next;
 
 				if(find_cached(cache, sa) != NOT_CACHED) {
 					continue;
 				}
 
-				cache->aip = cache->aip->ai_next;
 				return sa;
 			} else {
 				free_known_addresses(cache->ai);