#!/bin/sh

renew_wan_lease=0

ip monitor link dev eth0 | while read event; do
	
	# logger "maintain-wan-lease detected eth0 event: "$event

	case $event in

	*'NO-CARRIER'* )
		if [ $renew_wan_lease -eq 0 ]; then
			logger "maintain-wan-lease detected eth0 state change to: 'NO-CARRIER', so forcing udhcpc to release wan lease."
			killall -SIGUSR2 udhcpc
			renew_wan_lease=1		
		fi
	;;

	*'LOWER_UP'* )
		if [ $renew_wan_lease -eq 1 ]; then
			logger "maintain-wan-lease detected eth0 state change from: 'NO-CARRIER' to: 'LOWER_UP', so forcing udhcpc to renew wan lease."
			killall -SIGUSR1 udhcpc
			renew_wan_lease=0
		fi
	;;
	esac

done