From: Etienne Dechamps <etienne@edechamps.fr>
Date: Sat, 6 Sep 2014 09:43:15 +0000 (+0100)
Subject: Don't enable the device if the reachable count is zero.
X-Git-Tag: release-1.1pre11~47
X-Git-Url: https://www.tinc-vpn.org/git/browse?p=tinc;a=commitdiff_plain;h=7ac52637659b7f17ab5139010f0436aefcf9625c

Don't enable the device if the reachable count is zero.

A logic bug was introduced in bd451cfe1512fa69eac35a60dbe6df17bfc39154
in which running graph() several times with zero reachable nodes had
the effect of calling device_enable() (instead of keeping the device
disabled).

This results in weird behavior when DeviceStandby is enabled, especially
on Windows where calling device_enable() several times in a row corrupts
I/O structures for the device, rendering it unusable.
---

diff --git a/src/graph.c b/src/graph.c
index 8f601c21..690f4bd5 100644
--- a/src/graph.c
+++ b/src/graph.c
@@ -292,7 +292,7 @@ static void check_reachability(void) {
 	if (device_standby) {
 		if (reachable_count == 0 && became_unreachable_count > 0)
 			device_disable();
-		else if (reachable_count == became_reachable_count)
+		else if (reachable_count > 0 && reachable_count == became_reachable_count)
 			device_enable();
 	}
 }