From: Guus Sliepen <guus@tinc-vpn.org>
Date: Sat, 27 Feb 2016 13:46:01 +0000 (+0100)
Subject: Add warnings for bad combinations of Device and Interface.
X-Git-Tag: release-1.0.27~18
X-Git-Url: https://tinc-vpn.org/git/browse?a=commitdiff_plain;h=2f03a5d94c0bb6732fd65263217e3aa2b72f18ff;p=tinc

Add warnings for bad combinations of Device and Interface.

On Linux, the name of the tun/tap interface can be set freely. However,
on most other operating systems, tinc cannot change the name of the
interface. In those situations, it is possible to specify a Device and
an Interface that conflict with each other. On BSD, this can cause
$INTERFACE to be set incorrectly, on Windows, this results in a
potentially unreliable way in which a TAP-Win32 interface is selected.
---

diff --git a/src/bsd/device.c b/src/bsd/device.c
index 3e9cfb27..377d4a7b 100644
--- a/src/bsd/device.c
+++ b/src/bsd/device.c
@@ -75,6 +75,8 @@ static bool setup_device(void) {
 
 	if(!get_config_string(lookup_config(config_tree, "Interface"), &iface))
 		iface = xstrdup(strrchr(device, '/') ? strrchr(device, '/') + 1 : device);
+	else if(strcmp(iface, strrchr(device, '/') ? strrchr(device, '/') + 1 : device))
+		logger(LOG_WARNING, "Warning: Interface does not match Device. $INTERFACE might be set incorrectly.");
 
 	if(get_config_string(lookup_config(config_tree, "DeviceType"), &type)) {
 		if(!strcasecmp(type, "tun"))
diff --git a/src/cygwin/device.c b/src/cygwin/device.c
index b582a6a9..47867a49 100644
--- a/src/cygwin/device.c
+++ b/src/cygwin/device.c
@@ -61,6 +61,9 @@ static bool setup_device(void) {
 	get_config_string(lookup_config(config_tree, "Device"), &device);
 	get_config_string(lookup_config(config_tree, "Interface"), &iface);
 
+	if(device && interface)
+		logger(LOG_WARNING, "Warning: both Device and Interface specified, results may not be as expected");
+
 	/* Open registry and look for network adapters */
 
 	if(RegOpenKeyEx(HKEY_LOCAL_MACHINE, NETWORK_CONNECTIONS_KEY, 0, KEY_READ, &key)) {
diff --git a/src/mingw/device.c b/src/mingw/device.c
index 49b833ab..b77282ad 100644
--- a/src/mingw/device.c
+++ b/src/mingw/device.c
@@ -113,6 +113,9 @@ static bool setup_device(void) {
 	get_config_string(lookup_config(config_tree, "Device"), &device);
 	get_config_string(lookup_config(config_tree, "Interface"), &iface);
 
+	if(device && interface)
+		logger(LOG_WARNING, "Warning: both Device and Interface specified, results may not be as expected");
+
 	/* Open registry and look for network adapters */
 
 	if(RegOpenKeyEx(HKEY_LOCAL_MACHINE, NETWORK_CONNECTIONS_KEY, 0, KEY_READ, &key)) {