[package] base-files: kill possibly existing udhcpc instance when bringing up a dhcp iface, utilize service_kill() in dhcp shutdown.

Based on patch by Stijn Tintel. Possibly related to #7314



git-svn-id: svn://svn.openwrt.org/openwrt/trunk@23092 3c298f89-4303-0410-b956-a3cf2f4a3e73

package/base-files/files/lib/network/config.sh

@@ -340,15 +340,10 @@ setup_interface() {
 			setup_interface_static "$iface" "$config"
 		;;
 		dhcp)
-			local lockfile="/var/lock/dhcp-$iface"
-			lock "$lockfile"
-
-			# prevent udhcpc from starting more than once
+			# kill running udhcpc instance
 			local pidfile="/var/run/dhcp-${iface}.pid"
-			local pid="$(cat "$pidfile" 2>/dev/null)"
-			if [ -d "/proc/$pid" ] && grep -qs udhcpc "/proc/${pid}/cmdline"; then
-				lock -u "$lockfile"
-			else
+			service_kill udhcpc "$pidfile"
+
 			local ipaddr netmask hostname proto1 clientid broadcast
 			config_get ipaddr "$config" ipaddr
 			config_get netmask "$config" netmask
@@ -371,9 +366,6 @@ setup_interface() {
 				${clientid:+-c $clientid} \
 				-b -p "$pidfile" $broadcast \
 				${dhcpopts:- -O rootpath -R &}
-
-				lock -u "$lockfile"
-			fi
 		;;
 		none)
 			setup_interface_none "$iface" "$config"
@@ -401,12 +393,7 @@ stop_interface_dhcp() {
 	remove_dns "$config"
 
 	local pidfile="/var/run/dhcp-${ifname}.pid"
-	local pid="$(cat "$pidfile" 2>/dev/null)"
-	[ -d "/proc/$pid" ] && {
-		grep -qs udhcpc "/proc/$pid/cmdline" && kill -TERM $pid && \
-			while grep -qs udhcpc "/proc/$pid/cmdline"; do sleep 1; done
-		rm -f "$pidfile"
-	}
+	service_kill udhcpc "$pidfile"
 
 	uci -P /var/state revert "network.$config"
 }