netifd: Add renew handler for proto dhcp

Signed-off-by: Helmut Schaa <helmut.schaa@googlemail.com>

git-svn-id: svn://svn.openwrt.org/openwrt/trunk@40385 3c298f89-4303-0410-b956-a3cf2f4a3e73

package/network/config/netifd/files/lib/netifd/proto/dhcp.sh

@@ -5,6 +5,8 @@
 init_proto "$@"
 
 proto_dhcp_init_config() {
+	renew_handler=1
+
 	proto_config_add_string 'ipaddr:ipaddr'
 	proto_config_add_string 'hostname:hostname'
 	proto_config_add_string clientid
@@ -51,6 +53,13 @@ proto_dhcp_setup() {
 		$clientid $broadcast $dhcpopts
 }
 
+proto_dhcp_renew() {
+	local interface="$1"
+	# SIGUSR1 forces udhcpc to renew its lease
+	local sigusr1="$(kill -l SIGUSR1)"
+	[ -n "$sigusr1" ] && proto_kill_command "$interface" $sigusr1
+}
+
 proto_dhcp_teardown() {
 	local interface="$1"
 	proto_kill_command "$interface"