From ec7ba74900b734f0c7f23b0634308e5b266ffedf Mon Sep 17 00:00:00 2001
From: Erik Karlsson <erik.karlsson@iopsys.eu>
Date: Mon, 25 Mar 2024 12:01:49 +0100
Subject: [PATCH] testnet: avoid potential race condition

Instead of running a second instance of testnet once and in parallel
with the background task on interface up/down, the background task is
woken up. The avoids the potential for a race where under certain
circumstances a ubus event for internet up or down may never be sent.

Also remove unused include and add missing quotation.
---
 testnet/files/etc/init.d/testnet |  2 +-
 testnet/files/sbin/testnet       | 33 +++++++++++++++++---------------
 2 files changed, 19 insertions(+), 16 deletions(-)

diff --git a/testnet/files/etc/init.d/testnet b/testnet/files/etc/init.d/testnet
index ae82f89ee..3922275f2 100755
--- a/testnet/files/etc/init.d/testnet
+++ b/testnet/files/etc/init.d/testnet
@@ -19,5 +19,5 @@ start_service() {
 }
 
 reload_service() {
-	[ -n "$TESTNET" ] && procd_running testnet && "$TESTNET" once
+	procd_send_signal testnet
 }
diff --git a/testnet/files/sbin/testnet b/testnet/files/sbin/testnet
index 96abe4179..751bc440b 100755
--- a/testnet/files/sbin/testnet
+++ b/testnet/files/sbin/testnet
@@ -1,6 +1,7 @@
 #!/bin/sh
 
-. /lib/functions.sh
+RELOAD=0
+WAITING=0
 
 NETCON=0
 LASTSTATUS=""
@@ -13,32 +14,32 @@ test_connection() {
 	local defroute="$(ip r | grep default | awk '{print$3}' | head -1)"
 	local def6route="$(ip -f inet6 r | grep default | awk '{print$3}')"
 	local ping6dev="$(ip -f inet6 r | grep default | awk '{print$5}')"
-	local resolvfile="$(uci -q get dhcp.@dnsmasq[0].resolvfile)"
+	local resolvfile="$(uci -q get 'dhcp.@dnsmasq[0].resolvfile')"
 
 	if [ -n "$addr" ]; then
-		ping -q -w 5 -c 1 $addr >/dev/null 2>&1 && return 0
+		ping -q -w 5 -c 1 "$addr" >/dev/null 2>&1 && return 0
 	elif [ -n "$defroute" ]; then
-		ping -q -w 5 -c 1 $defroute >/dev/null 2>&1 && return 0
+		ping -q -w 5 -c 1 "$defroute" >/dev/null 2>&1 && return 0
 		if [ -e "$resolvfile" ]; then
 			for nmsrv in $(grep nameserver "$resolvfile" | awk '{print$2}'); do
-				ping -q -w 5 -c 1 $nmsrv >/dev/null 2>&1 && return 0
+				ping -q -w 5 -c 1 "$nmsrv" >/dev/null 2>&1 && return 0
 			done
 		fi
 	elif [ -n "$def6route" -a -n "$ping6dev" ]; then
-		ndisc6 -w 5 -1 $def6route $ping6dev >/dev/null 2>&1 && return 0
+		ndisc6 -w 5 -1 "$def6route" "$ping6dev" >/dev/null 2>&1 && return 0
 	fi
 	return 1
 }
 
 internet_test() {
-	local link dest
+	local dest
 
 	# use the destination address given in config for connectivity check
 	dest="$(uci -q get testnet.global.destination)"
 	# for backwards compatibility
-	[ -n "$dest" ] || dest="$(uci -q get system.@system[0].netping_addr)"
+	[ -n "$dest" ] || dest="$(uci -q get 'system.@system[0].netping_addr')"
 
-	test_connection $dest
+	test_connection "$dest"
 
 	if [ "$?" -eq 0 ]; then
 		NETCON=1
@@ -52,7 +53,7 @@ internet_test() {
 connectivity_test() {
 	internet_test
 
-	if [ $NETCON -eq 1 ]; then
+	if [ "$NETCON" -eq 1 ]; then
 		CURSTATUS=1
 		[ "$CURSTATUS" == "$LASTSTATUS" ] || ubus send internet '{"status" : "online"}'
 		LASTSTATUS=1
@@ -63,12 +64,14 @@ connectivity_test() {
 	fi
 }
 
-if [ "$1" == "once" ]; then
-	connectivity_test
-	exit 0
-fi
+trap RELOAD=1 HUP
 
 while true; do
+	if [ "$WAITING" -eq 0 ]; then
+		sleep "$SLEEP_TIME" &
+		WAITING=1
+	fi
+	RELOAD=0
 	connectivity_test
-	sleep $SLEEP_TIME
+	[ "$RELOAD" -eq 0 ] && wait && WAITING=0
 done