From 822bc96b7cb972e07e92647f11dfe01579d67ed7 Mon Sep 17 00:00:00 2001
From: Florian Eckert <fe@dev.tdt.de>
Date: Thu, 22 Jun 2017 11:48:01 +0200
Subject: [PATCH] net/mwan3: add lock for mwan3 hotplug script

If more then one interface get up/down at once mwan3 could be in a
undefined state, because more then one mwan3 hotplug script are running
and editing the iptables.

Lock the critical section should solve this issue.

Signed-off-by: Florian Eckert <fe@dev.tdt.de>
(cherry picked from commit b6e9debc1b97f9e4be70fb51404831ed870d844a)
---
 net/mwan3/files/etc/hotplug.d/iface/15-mwan3 | 3 +++
 net/mwan3/files/lib/mwan3/mwan3.sh           | 8 ++++++++
 2 files changed, 11 insertions(+)

diff --git a/net/mwan3/files/etc/hotplug.d/iface/15-mwan3 b/net/mwan3/files/etc/hotplug.d/iface/15-mwan3
index 51bba594f2..ae18f529f1 100644
--- a/net/mwan3/files/etc/hotplug.d/iface/15-mwan3
+++ b/net/mwan3/files/etc/hotplug.d/iface/15-mwan3
@@ -35,6 +35,7 @@ if [ "$ACTION" == "ifup" ]; then
 	[ -n "$gateway" ] || exit 9
 fi
 
+mwan3_lock
 $LOG notice "$ACTION interface $INTERFACE (${DEVICE:-unknown})"
 
 case "$ACTION" in
@@ -58,4 +59,6 @@ case "$ACTION" in
 	;;
 esac
 
+mwan3_unlock
+
 exit 0
diff --git a/net/mwan3/files/lib/mwan3/mwan3.sh b/net/mwan3/files/lib/mwan3/mwan3.sh
index 1e1de969fa..eae69b7293 100644
--- a/net/mwan3/files/lib/mwan3/mwan3.sh
+++ b/net/mwan3/files/lib/mwan3/mwan3.sh
@@ -7,6 +7,14 @@ IPT4="/usr/sbin/iptables -t mangle -w"
 IPT6="/usr/sbin/ip6tables -t mangle -w"
 LOG="/usr/bin/logger -t mwan3 -p"
 
+mwan3_lock() {
+	lock /var/run/mwan3.lock
+}
+
+mwan3_unlock() {
+	lock -u /var/run/mwan3.lock
+}
+
 mwan3_get_iface_id()
 {
 	local _tmp _iface _iface_count
-- 
2.30.2