#!/bin/sh
INTERVAL=10
PACKETS=1
UDHCPC="udhcpc -i vlan1 -p /var/run/udhcpc.pid -s /tmp/udhcpc"
IFACE=vlan1


ME=`basename $0`
RUNNING=`ps | awk '/'"$ME"'/ {++x}; END {print x+0}'`
if [ "$RUNNING" -gt 3 ]; then
echo "Another instance of \"$ME\" is running"
exit 1
fi

while sleep $INTERVAL
do
TARGET=`ip route | awk '/default via/ {print $3}'`
RET=`ping -c $PACKETS $TARGET 2> /dev/null | awk '/packets received/ {print $4}'`

if [ "$RET" -ne "$PACKETS" ]; then
echo "Ping failed, releasing IP address on $IFACE"
#send a RELEASE signal
kill -USR2 `cat /var/run/udhcpc.pid` 2> /dev/null
#ensure udhcpc is not running
killall udhcpc 2> /dev/null
echo "Renewing IP address: $IFACE"
$UDHCPC
echo "Waiting 10 s..."
sleep 10
else
echo "Network is up via $TARGET"
fi
done

INTERVAL=10
while true; do
while [ \! $gw ]; do
sleep 30
route -n >/tmp/routes
while read dest gw foo; do
if [ $dest = "0.0.0.0" ]; then
break
fi
done
done
logger "auto-repair: default gateway is $gw"
while ping -qc 2 $gw >/dev/null ; do
sleep $INTERVAL
done
logger "auto-repair: gateway down, restarting WAN"
kill -USR1 `cat /var/run/udhcpc.pid`
unset gw
done &