[Buildroot] [PATCH 2/2] package/lldpd: rework start script

[Joachim Wiberg <troglobit@gmail.com>]

check-package reports six warnings on S60lldpd: indentation with
spaces, no DAEMON variable, and shellcheck complaints.

The script also masks failures, the exit status of
"[ $? = 0 ] && echo OK || echo FAIL" is the one of echo, so start and
stop always return success.  Stopping does not wait for the daemon to
exit either, so a restart can race the instance on its way out.

Rewrite it after package/busybox/S01syslogd, as the manual asks.  lldpd
daemonizes and writes the PID file itself, but does not remove it on
exit, so pass the PID file to both start-stop-daemon and the daemon and
drop the stale file once the process is gone.  Also pick up arguments
from /etc/default/lldpd and add the customary reload alias.

Signed-off-by: Joachim Wiberg <troglobit@gmail.com>
---
 package/lldpd/S60lldpd | 80 ++++++++++++++++++++++++++++++------------
 1 file changed, 58 insertions(+), 22 deletions(-)

diff --git a/package/lldpd/S60lldpd b/package/lldpd/S60lldpd
index 3dfa6c1aa1..79605c2f02 100644
--- a/package/lldpd/S60lldpd
+++ b/package/lldpd/S60lldpd
@@ -1,25 +1,61 @@
 #!/bin/sh
-#
-# Controls lldpd.
-#
 
-case $1 in
-    start)
-	printf "Starting lldpd: "
-	start-stop-daemon -S -q -p /var/run/lldpd.pid --exec /usr/sbin/lldpd
-	[ $? = 0 ] && echo "OK" || echo "FAIL"
-	;;
-    stop)
-	printf "Stopping lldpd: "
-	start-stop-daemon -K -q -p /var/run/lldpd.pid
-	[ $? = 0 ] && echo "OK" || echo "FAIL"
-	;;
-    restart)
-	$0 stop
-	$0 start
-	;;
-    *)
-	echo "Usage: $0 {start|stop|restart}"
-	exit 1
-	;;
+DAEMON="lldpd"
+PIDFILE="/var/run/$DAEMON.pid"
+
+LLDPD_ARGS=""
+
+# shellcheck source=/dev/null
+[ -r "/etc/default/$DAEMON" ] && . "/etc/default/$DAEMON"
+
+# lldpd daemonizes and creates the PID file itself, so tell it where to
+# put it, but it does not remove it on exit.
+start() {
+	printf 'Starting %s: ' "$DAEMON"
+	# shellcheck disable=SC2086 # we need the word splitting
+	start-stop-daemon --start --pidfile "$PIDFILE" \
+		--exec "/usr/sbin/$DAEMON" \
+		-- -p "$PIDFILE" $LLDPD_ARGS
+	status=$?
+	if [ "$status" -eq 0 ]; then
+		echo "OK"
+	else
+		echo "FAIL"
+	fi
+	return "$status"
+}
+
+stop() {
+	printf 'Stopping %s: ' "$DAEMON"
+	start-stop-daemon --stop --pidfile "$PIDFILE" \
+		--exec "/usr/sbin/$DAEMON"
+	status=$?
+	if [ "$status" -eq 0 ]; then
+		echo "OK"
+	else
+		echo "FAIL"
+		return "$status"
+	fi
+	while start-stop-daemon --stop --test --quiet --pidfile "$PIDFILE" \
+		--exec "/usr/sbin/$DAEMON"; do
+		sleep 0.1
+	done
+	rm -f "$PIDFILE"
+	return "$status"
+}
+
+restart() {
+	stop
+	start
+}
+
+case "$1" in
+	start|stop|restart)
+		"$1";;
+	reload)
+		# Restart, since there is no true "reload" feature.
+		restart;;
+	*)
+		echo "Usage: $0 {start|stop|restart|reload}"
+		exit 1
 esac
-- 
2.43.0

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