don't let 0.0.0.0 be valid for upnp because some devices that are not internet…

 don't let 0.0.0.0 be valid for upnp because some devices that are not internet gateways will return this ie printers 

git-svn-id: http://svn.freeswitch.org/svn/freeswitch/trunk@13720 d0543943-73ff-0310-b7d9-9358b9ac24b2

src/switch_nat.c

@@ -74,6 +74,7 @@ static int init_upnp (void)
 		}
 		if (!dev) {
 			dev = devlist; /* defaulting to first device */
+			switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_DEBUG, "No InternetGatewayDevice, using first entry as default.\n");
 		}
 		
 		descXML = miniwget(dev->descURL, &descXMLsize);
@@ -91,6 +92,12 @@ static int init_upnp (void)
 									   nat_globals.data.servicetype,
 									   nat_globals.pub_addr)) == UPNPCOMMAND_SUCCESS) {
 
+		if (!strcmp(nat_globals.pub_addr, "0.0.0.0")) {
+			switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_ERROR, 
+							  "uPNP Device (url: %s) returned an invalid external address of 0.0.0.0.  Disabling uPNP\n", nat_globals.urls.controlURL);
+			return -2;
+		}
+
 		nat_globals.nat_type = SWITCH_NAT_TYPE_UPNP;
 		return 0;
 	}