isc-dhcp: dhcrelay: Add more UCI options

Add more options to dhcrelay UCI and init script:

- enabled
- interfaces: Listen interfaces
- relay_mode: What to do about packets that already have a relay option

Also mark /etc/config/dhcrelay as conffile

Signed-off-by: Bruno Randolf <br1@einfach.org>

git-svn-id: svn://svn.openwrt.org/openwrt/packages@38446 3c298f89-4303-0410-b956-a3cf2f4a3e73

net/isc-dhcp/files/dhcrelay4.init

@@ -8,15 +8,39 @@ SERVICE_PID_FILE="/var/run/dhcrelay4.pid"
 SERVICE_USE_PID=1
 
 start() {
-    local relay_dhcpserver
+	. /lib/functions/network.sh
+	config_load dhcrelay
+	local args=""
 
-    config_load dhcrelay
-    config_get relay_dhcpserver ipv4 dhcpserver
+	local enabled
+	config_get_bool enabled ipv4 enabled 0
+	[ "$enabled" -eq 0 ] && return 0
 
-    service_start /usr/sbin/dhcrelay -4 -q \
-        -pf $SERVICE_PID_FILE $relay_dhcpserver
+	# listen interfaces
+	local interfaces
+	local ifname
+	config_get interfaces ipv4 interfaces
+	for net in $interfaces; do
+		if network_get_device ifname "$net"; then
+			append args "-i $ifname"
+		fi
+	done
+
+	# relay mode
+	local relay_mode
+	config_get relay_mode ipv4 relay_mode
+	[ -n "$relay_mode" ] && append args "-m $relay_mode"
+
+	# dhcp server address
+	local server
+	config_get server ipv4 dhcpserver
+	[ -n "$server" ] || return 0
+	append args "$server"
+
+	service_start /usr/sbin/dhcrelay -4 -q \
+		-pf $SERVICE_PID_FILE $args
 }
 
 stop() {
-    service_stop /usr/sbin/dhcrelay
+	service_stop /usr/sbin/dhcrelay
 }

net/isc-dhcp/files/etc/config/dhcrelay

@@ -1,10 +1,24 @@
 
 config dhcrelay ipv4
-    option dhcpserver '192.0.2.10'
+	option 'enabled' '0'
+
+	# IP address of the server
+	option 'dhcpserver' '192.0.2.10'
+
+	# network interfaces to listen on (e.g. lan or wan)
+	option 'interfaces' ''
+
+	# What to do about packets that already have a relay option:
+	# 'append': Forward and append our own relay option
+	# 'replace': Forward, but replace theirs with ours (default)
+	# 'forward': Forward without changes
+	# 'discard': Don't forward
+	option 'relay_mode' ''
+
 
 config dhcrelay ipv6
-#    option dhcpserver '2001:db8:1::1'
-    option upper 'eth1'
-    list lower 'eth0.2'
-    list lower 'eth0.3'
+#	option dhcpserver '2001:db8:1::1'
+	option upper 'eth1'
+	list lower 'eth0.2'
+	list lower 'eth0.3'