#!/bin/sh
#by cuma

[ ! -r /var/mod/etc/conf/ppp.cfg ] && exit 1
. /var/mod/etc/conf/ppp.cfg

[ -z "$PPP_FABALOG" ] && PPP_FABALOG='/dev/null'

willkommen() {
	[ "$PPP_FALLBACK" != 'yes' ] || echo -e "\n$(date): DIALIN" >> $PPP_FABALOG
	start-stop-daemon -n ppp_dialer -a /etc/default.ppp/ppp_dialer -b -q -S
}

bisbald () {
	HURET=1
	while [ $HURET -ne 0 ]; do
		[ "$PPP_FALLBACK" != 'yes' ] || echo -e "\n$(date): HANGUP" >> $PPP_FABALOG
		/etc/init.d/rc.ppp disconnect
		HURET=$?
	done
}

reanimiert () {
	[ -n "$ALIVEIP" ] && route del $ALIVEIP 2>/dev/null
	if [ -z "$ALIVEIP" -a -z "$CURRENT_ROUTE" ]; then
		echo "############################# CHECK NICHT MÖGLICH: Verbindung wird nicht automatisch getrennt!" >> $PPP_FABALOG
		exit 1
	fi
	$CURRENT_ROUTE
	NEXTCHK=$(( $(date +%s)+$PPP_CHECKINTERVAL ))
	BACKONLINE=0
	while [ "$BACKONLINE" != "1" ]; do
		SLEEPTIME=$(( $NEXTCHK-$(date +%s) ))
		if [ $SLEEPTIME -gt 0 ]; then
			echo "$(date): sleeping" >> $PPP_FABALOG
			sleep $SLEEPTIME
		fi
		NEXTCHK=$(( $(date +%s)+$PPP_CHECKINTERVAL ))
		ping -c 1 -W 2 -w 2 -q $ALIVEIP >/dev/null 2>&1
		[ $? -eq 0 ] && BACKONLINE=1
	done
	[ -n "$ALIVEIP" ] && route del $ALIVEIP 2>/dev/null
	bisbald
}

pinger() {
	for SINGLEHOST in $PPP_CHECKHOSTS; do
		echo -n "$(date): checking $SINGLEHOST" >> $PPP_FABALOG
		ping -c 1 -W 2 -w 2 -q $SINGLEHOST >/dev/null 2>&1
		if [ $? -eq 0 ]; then
			echo " OKAY" >> $PPP_FABALOG
			if [ -z "$ALIVEIP" ]; then
				ALIVEIP=$(nslookup $PPP_ALIVECHECK | tail -n1 | tr -s " " | cut -d" " -f3)
				if [ $? -ne 0 ]; then
					ALIVEIP=
				else
					CURRENT_IF=$(route -n | grep "^0.0.0.0" | tail -n1 | tr -s " " | cut -d " " -f8)
					CURRENT_GW=$(route -n | grep "^0.0.0.0" | tail -n1 | tr -s " " | cut -d " " -f2)
					if [ "$CURRENT_GW" != "0.0.0.0" ]; then
						CURRENT_ROUTE="route add $ALIVEIP gw $CURRENT_GW"
					else
						[ -n "$CURRENT_IF" ] && CURRENT_ROUTE="route add $ALIVEIP $CURRENT_IF"
					fi
					echo -e "\n$(date): CURRENT_ROUTE: $CURRENT_ROUTE\n"  >> $PPP_FABALOG
				fi
			fi
			return 0
		else
			echo " FAIL" >> $PPP_FABALOG
		fi
	done
	return 1
}

if [ "$PPP_FALLBACK" != 'yes' ]; then
	willkommen
else
	NEXTRUN=$(( $(date +%s)+$PPP_CHECKTIMEOUT ))
	LASTSUCCESS=$(( $NEXTRUN+$PPP_CHECKTIMEOUT ))
	while [ 1 ]; do
		SLEEPTIME=$(( $NEXTRUN-$(date +%s) ))
		[ $SLEEPTIME -gt 0 ] && sleep $SLEEPTIME
		NEXTRUN=$(( $(date +%s)+$PPP_CHECKINTERVAL ))
		pinger
			if [ $? -eq 0 ]; then
			LASTSUCCESS=$(date +%s)
		else
			if [ $(( $LASTSUCCESS+$PPP_CHECKTIMEOUT )) -lt $(date +%s) ]; then
				willkommen
				reanimiert
			fi
		fi
	done
fi