From: Etienne Dechamps <etienne@edechamps.fr>
Date: Sat, 12 Jul 2014 10:06:36 +0000 (+0100)
Subject: Handle the "no local address" case in send_sptps_data().
X-Git-Tag: release-1.1pre11~71
X-Git-Url: https://www.tinc-vpn.org/git/browse?p=tinc;a=commitdiff_plain;h=77e96c07912c2a8b280d3e812c71fa1f12efb0ff

Handle the "no local address" case in send_sptps_data().

If choose_local_address() is unable to find a local address (e.g.
because of old nodes that don't send their local address information),
then send_sptps_data() ends up using uninitialized variables for the
socket and address.

This regression was introduced in
415910897122da0073a862784d148802ca390020. The commit took care of
handling that case in send_udppacket() but was missing the same fix
for send_sptps_data().

This bug was found by the clang static analyzer tool:
http://clang-analyzer.llvm.org/
---

diff --git a/src/net_packet.c b/src/net_packet.c
index 6b3183da..609b4527 100644
--- a/src/net_packet.c
+++ b/src/net_packet.c
@@ -769,12 +769,12 @@ bool send_sptps_data(void *handle, uint8_t type, const char *data, size_t len) {
 
 	/* Otherwise, send the packet via UDP */
 
-	const sockaddr_t *sa;
+	const sockaddr_t *sa = NULL;
 	int sock;
 
 	if(to->status.send_locally)
 		choose_local_address(to, &sa, &sock);
-	else
+	if(!sa)
 		choose_udp_address(to, &sa, &sock);
 
 	if(sendto(listen_socket[sock].udp.fd, data, len, 0, &sa->sa, SALEN(sa->sa)) < 0 && !sockwouldblock(sockerrno)) {