From: Guus Sliepen <guus@tinc-vpn.org>
Date: Thu, 11 Jun 2009 16:36:08 +0000 (+0200)
Subject: Don't try to send MTU probes to unreachable nodes.
X-Git-Tag: import-tinc-1.1~592^2~30
X-Git-Url: https://git.meshlink.io/?a=commitdiff_plain;h=36f8e4da8b1708474505f5a1fa8cf1ba848921de;p=meshlink

Don't try to send MTU probes to unreachable nodes.

If there is an outstanding MTU probe event for a node which is not reachable
anymore, a UDP packet would be sent to that node, which caused a key request to
be sent to that node, which triggered a NULL pointer dereference. Probes and
other UDP packets to unreachable nodes are now dropped.
---

diff --git a/src/meta.c b/src/meta.c
index a32d4137..b59f15b0 100644
--- a/src/meta.c
+++ b/src/meta.c
@@ -41,6 +41,11 @@ bool send_meta(connection_t *c, const char *buffer, int length)
 
 	cp();
 
+	if(!c) {
+		logger(LOG_ERR, _("send_meta() called with NULL pointer!"));
+		abort();
+	}
+
 	ifdebug(META) logger(LOG_DEBUG, _("Sending %d bytes of metadata to %s (%s)"), length,
 			   c->name, c->hostname);
 
diff --git a/src/net_packet.c b/src/net_packet.c
index 40d94518..9f612751 100644
--- a/src/net_packet.c
+++ b/src/net_packet.c
@@ -70,6 +70,11 @@ void send_mtu_probe(node_t *n)
 	n->mtuprobes++;
 	n->mtuevent = NULL;
 
+	if(!n->status.reachable) {
+		ifdebug(TRAFFIC) logger(LOG_INFO, _("Trying to send MTU probe to unreachable node %s (%s)"), n->name, n->hostname);
+		return;
+	}
+
 	if(n->mtuprobes >= 10 && !n->minmtu) {
 		ifdebug(TRAFFIC) logger(LOG_INFO, _("No response to MTU probes from %s (%s)"), n->name, n->hostname);
 		return;
@@ -328,6 +333,11 @@ static void send_udppacket(node_t *n, vpn_packet_t *origpkt)
 
 	cp();
 
+	if(!n->status.reachable) {
+		ifdebug(TRAFFIC) logger(LOG_INFO, _("Trying to send UDP packet to unreachable node %s (%s)"), n->name, n->hostname);
+		return;
+	}
+
 	/* Make sure we have a valid key */
 
 	if(!n->status.validkey) {