lldpd: Init config read on reload

Init script reload with trigger to detect config file update.
Reload command added to attempt non-impactful lldpd reload where
lldpcli can be used to update config without process restart.
Config hash function used to track whether process restart is needed.

Signed-off-by: Stephen Howell <howels@allthatwemight.be>

package/network/services/lldpd/files/lldpd.init

@@ -5,11 +5,17 @@ START=90
 STOP=01
 
 USE_PROCD=1
+LLDPDBIN=/usr/sbin/lldpd
 LLDPCLI=/usr/sbin/lldpcli
 LLDPSOCKET=/var/run/lldpd.socket
 LLDPD_CONF=/tmp/lldpd.conf
 LLDPD_CONFS_DIR=/tmp/lldpd.d
 
+LLDPD_RUN=/var/run/lldpd
+LLDPD_RESTART_HASH=${LLDPD_RUN}/lldpd.restart_hash
+
+. "$IPKG_INSTROOT/lib/functions/network.sh"
+
 find_release_info()
 {
 	[ -s /etc/os-release ] && . /etc/os-release
@@ -19,10 +25,27 @@ find_release_info()
 	echo "${PRETTY_NAME:-Unknown OpenWrt release} @ $(cat /proc/sys/kernel/hostname)"
 }
 
+get_config_restart_hash() {
+	local var="$1"
+	local _string _hash v
+
+	config_load 'lldpd'
+
+	config_get      v 'config' 'lldp_class'; append _string "$v" ","
+	config_get      v 'config' 'agentxsocket'; append _string "$v" ","
+	config_get_bool v 'config' 'readonly_mode'; append _string "$v" ","
+	config_get_bool v 'config' 'enable_lldp' 1; append _string "$v" ","
+	config_get_bool v 'config' 'enable_cdp'; append _string "$v" ","
+	config_get_bool v 'config' 'enable_edp'; append _string "$v" ","
+	config_get_bool v 'config' 'enable_fdp'; append _string "$v" ","
+	config_get_bool v 'config' 'enable_sonmp'; append _string "$v" ","
+
+	_hash=`echo -n "${_string}" | md5sum | awk '{ print \$1 }'`
+	export -n "$var=$_hash"
+}
+
 write_lldpd_conf()
 {
-	. /lib/functions/network.sh
-
 	local lldp_description
 
 	config_load 'lldpd'
@@ -60,10 +83,6 @@ write_lldpd_conf()
 	[ -e $LLDPD_CONFS_DIR ] || ln -s /etc/lldpd.d $LLDPD_CONFS_DIR
 }
 
-service_triggers() {
-	procd_add_reload_trigger "lldpd"
-}
-
 start_service() {
 
 	local enable_cdp
@@ -85,14 +104,15 @@ start_service() {
 	config_get_bool readonly_mode 'config' 'readonly_mode' 0
 	config_get agentxsocket 'config' 'agentxsocket'
 
-	mkdir -p /var/run/lldp
+	mkdir -p ${LLDPD_RUN}
-	chown lldp:lldp /var/run/lldp
+	chown lldp:lldp ${LLDPD_RUN}
 
 	# When lldpd starts, it also loads up what we write in this config file
 	write_lldpd_conf
 
 	procd_open_instance
-	procd_set_param command /usr/sbin/lldpd -d
+	procd_set_param command ${LLDPDBIN}
+	procd_append_param command -d
 
 	[ $enable_cdp -gt 0 ] && procd_append_param command '-c'
 	[ $enable_fdp -gt 0 ] && procd_append_param command '-f'
@@ -102,13 +122,38 @@ start_service() {
 	[ -n "$lldp_class" ] && procd_append_param command -M "$lldp_class"
 	[ -n "$agentxsocket" ] && procd_append_param command -x -X "$agentxsocket"
 
+    # Overwrite default configuration locations processed by lldpcli at start
+	procd_append_param command -O "$LLDPD_CONF"
+
+	local restart_hash
+	get_config_restart_hash restart_hash
+	echo -n "$restart_hash" > $LLDPD_RESTART_HASH
+
 	# set auto respawn behavior
 	procd_set_param respawn
 	procd_close_instance
 }
 
+service_triggers() {
+	procd_add_config_trigger "config.change" "lldpd" /etc/init.d/lldpd reload
+}
+
 reload_service() {
 	running || return 1
+	
+	local running_hash=""
+	local config_hash=""
+
+	get_config_restart_hash config_hash
+	if [ -f ${LLDPD_RESTART_HASH} ]; then running_hash=`cat $LLDPD_RESTART_HASH`; fi
+
+	if [ "x$running_hash" != "x$config_hash" ]; then
+		# Restart LLDPd
+		# Some parameters can't be configured at runtime
+		restart
+		return 0
+	fi
+	
 	$LLDPCLI -u $LLDPSOCKET &> /dev/null <<-EOF
 		pause
 		unconfigure lldp custom-tlv
@@ -130,5 +175,6 @@ reload_service() {
 }
 
 stop_service() {
-	rm -rf /var/run/lldp $LLDPSOCKET
+	rm -rf ${LLDPD_RUN} $LLDPSOCKET 2>/dev/null
 }
+