From 1fd3f85d4fbcacd817383df479c5674c4ff13e3e Mon Sep 17 00:00:00 2001
From: Florian Eckert <fe@dev.tdt.de>
Date: Mon, 8 May 2017 11:43:27 +0200
Subject: [PATCH] net/mwan3: remove pid file use pgrep to get pid

If mwan3track will not stop immediately after sending the kill signal,
the clean_up handler will delete the pid file later while the new mwan3track is
already running.

This could result in a situation that mwan3track is running
more then once because the old mwan3track service could not be killed,
because the pid file is missing.

Using pgrep to kill all mwan3track for the tracked interface and not using
pid file should fix this issue.

Signed-off-by: Florian Eckert <fe@dev.tdt.de>
---
 net/mwan3/files/lib/mwan3/mwan3.sh     | 20 ++++++--------------
 net/mwan3/files/usr/libexec/rpcd/mwan3 | 12 ++++--------
 net/mwan3/files/usr/sbin/mwan3         |  4 +---
 net/mwan3/files/usr/sbin/mwan3track    |  7 +++----
 4 files changed, 14 insertions(+), 29 deletions(-)

diff --git a/net/mwan3/files/lib/mwan3/mwan3.sh b/net/mwan3/files/lib/mwan3/mwan3.sh
index f0ebcc42e..561aaede6 100644
--- a/net/mwan3/files/lib/mwan3/mwan3.sh
+++ b/net/mwan3/files/lib/mwan3/mwan3.sh
@@ -390,10 +390,7 @@ mwan3_track()
 	}
 	config_list_foreach $1 track_ip mwan3_list_track_ips
 
-	if [ -e /var/run/mwan3track-$1.pid ] ; then
-		kill $(cat /var/run/mwan3track-$1.pid) &> /dev/null
-	fi
-
+	kill $(pgrep -f "mwan3track $1") &> /dev/null
 	if [ -n "$track_ips" ]; then
 		[ -x /usr/sbin/mwan3track ] && /usr/sbin/mwan3track $1 $2 $track_ips &
 	fi
@@ -401,18 +398,13 @@ mwan3_track()
 
 mwan3_track_signal()
 {
-	local pid status
+	local pid
 
-	if [ -f "/var/run/mwan3track-${1}.pid" ]; then
-		pid="$(cat "/var/run/mwan3track-${1}.pid")"
-		status="$(pgrep -f mwan3track | grep "${pid}")"
-		if [ "${status}" != "" ]; then
-			kill -USR1 "${pid}"
-		else
-			$LOG warn "Unable to send signal USR1 to mwan3track on interface $1 with pid ${pid}"
-		fi
+	pid="$(pgrep -f "mwan3track $1")"
+	if [ "${pid}" != "" ]; then
+		kill -USR1 "${pid}"
 	else
-		$LOG warn "Unable to find \"/var/run/mwan3track-${1}.pid\" file for mwan3track on interface $1"
+		$LOG warn "Unable to send signal USR1 to mwan3track on interface $1 with pid ${pid}"
 	fi
 }
 
diff --git a/net/mwan3/files/usr/libexec/rpcd/mwan3 b/net/mwan3/files/usr/libexec/rpcd/mwan3
index 028dafe1d..2b8046068 100755
--- a/net/mwan3/files/usr/libexec/rpcd/mwan3
+++ b/net/mwan3/files/usr/libexec/rpcd/mwan3
@@ -34,16 +34,12 @@ get_mwan3_status() {
 	local iface="${1}"
 	local iface_select="${2}"
 	local running="0"
-	local pid=""
-	local status=""
+	local pid
 
 	if [ "${iface}" = "${iface_select}" ] || [ "${iface_select}" = "" ]; then
-		if [ -f "${MWAN3_PID_FILE}-${iface}.pid" ]; then
-			pid="$(cat "${MWAN3_PID_FILE}-${iface}.pid")"
-			status="$(pgrep -f mwan3track | grep "${pid}")"
-			if [ "${status}" != "" ]; then
-				running="1"
-			fi
+		pid="$(pgrep -f "mwan3track $iface_selected")"
+		if [ "${pid}" != "" ]; then
+			running="1"
 		fi
 
 		json_add_object "${iface}"
diff --git a/net/mwan3/files/usr/sbin/mwan3 b/net/mwan3/files/usr/sbin/mwan3
index 63617316c..10dc86f8f 100755
--- a/net/mwan3/files/usr/sbin/mwan3
+++ b/net/mwan3/files/usr/sbin/mwan3
@@ -42,9 +42,7 @@ ifdown()
 
 	ACTION=ifdown INTERFACE=$1 /sbin/hotplug-call iface
 
-	if [ -e /var/run/mwan3track-$1.pid ] ; then
-		kill $(cat /var/run/mwan3track-$1.pid)
-	fi
+	kill $(pgrep -f "mwan3track $1") &> /dev/null
 }
 
 ifup()
diff --git a/net/mwan3/files/usr/sbin/mwan3track b/net/mwan3/files/usr/sbin/mwan3track
index 0d7b5ab5d..58a31f0ca 100755
--- a/net/mwan3/files/usr/sbin/mwan3track
+++ b/net/mwan3/files/usr/sbin/mwan3track
@@ -10,8 +10,9 @@ IFDOWN_EVENT=0
 
 clean_up() {
 	$LOG notice "Stopping mwan3track for interface \"${INTERFACE}\""
-	rm "/var/run/mwan3track-${INTERFACE}.pid" &> /dev/null
-	rm -rf "/var/run/mwan3track/${INTERFACE}" &> /dev/null
+	if [ "$(pgrep -f "mwan3track ${INTERFACE}")" = "" ]; then
+		rm -rf "/var/run/mwan3track/${INTERFACE}" &> /dev/null
+	fi
 	if [ -z "$(ls -A "/var/run/mwan3track")" ]; then
 		rm -rf "/var/run/mwan3track"
 	fi
@@ -31,7 +32,6 @@ main() {
 
 	INTERFACE=$1
 	DEVICE=$2
-	echo "$$" > /var/run/mwan3track-$1.pid
 	mkdir -p /var/run/mwan3track/$1
 	trap clean_up SIGINT SIGTERM
 	trap if_down SIGUSR1
@@ -103,7 +103,6 @@ main() {
 			if [ $score -eq $up ]; then
 				$LOG notice "Interface $1 ($2) is online"
 				env -i ACTION=ifup INTERFACE=$1 DEVICE=$2 /sbin/hotplug-call iface
-				rm /var/run/mwan3track-$1.pid
 				rm -rf "/var/run/mwan3track/${1}" &> /dev/null
 				exit 0
 			fi