[packages] ddns-scripts: add an option to specify the used interface - default to wan to retain compatibility (#7570)

git-svn-id: svn://svn.openwrt.org/openwrt/packages@27657 3c298f89-4303-0410-b956-a3cf2f4a3e73

net/ddns-scripts/files/usr/lib/ddns/dynamic_dns_functions.sh

@@ -110,6 +110,8 @@ verbose_echo()
 
 start_daemon_for_all_ddns_sections()
 {
+	local event_interface="$1"
+
 	SECTIONS=""
 	config_cb() 
 	{
@@ -119,6 +121,9 @@ start_daemon_for_all_ddns_sections()
 
 	for section in $SECTIONS
 	do
+		local iface
+		config_get iface "$section" interface "wan"
+		[ "$iface" = "$event_interface" ] || continue
 		/usr/lib/ddns/dynamic_dns_updater.sh $section 0 > /dev/null 2>&1 &
 	done
 }