#!/sbin/runscript
# Copyright 1999-2008 Gentoo Foundation
# Distributed under the terms of the GNU General Public License v2
# $Header: $

depend() {
	need net
}

source /lib/rc/net/iproute2.sh

_checks() {
	if [ -z "${IFACE}" ]; then
		eerror 'You need to set $IFACE!'
		return 1
	fi
}

_flush_routes() {
	while true; do
			# using 'route' instead of 'ip route', because its output can be parsed easier
		ROUTER="$(route -n | awk '$8 == "'"${IFACE}"'"&& $5 == "'"${METRIC}"'" && $1 == "0.0.0.0" && $2 != "0.0.0.0" { print $2 }')"
		[ -z "${ROUTER}" ] && break

		ebegin "Disabling route through ${ROUTER}"
		ip route del default via "${ROUTER}" dev "${IFACE}" # not provided by iproute2.sh
		RET=$?
		eend ${RET}

		[ ${RET} -ne 0 ] && return ${RET}
	done
}

start() {
	_checks || return $?
	_flush_routes || return $? # we really always want to clear old route 'in case'

	SSDPADDR="${SSDPADDR:-$(_get_inet_address)}" # upnpc

	if [ -z "${IFACE}" ]; then
		eerror "I failed to determine IP of ${IFACE}. Please set \$SSDPADDR!"
		return 1
	fi

	ebegin "Trying to find any router using UPnP"
	eval "$(upnpc -m "${SSDPADDR%/*}" -s 2>/dev/null | perl -e '
		local $/;
		<> =~ /Found valid IGD\s+:\s+http:\/\/([\d\.]{7,}).*?ExternalIPAddress = ([\d\.]{7,})/s
			or exit 1;
		print "ROUTER=$1; MYIP=$2"
	')"

	[[ $? -eq 0 && -n "${ROUTER}" && -n "${MYIP}" ]]
	RET=$?
	eend ${RET}

	if [ "${ROUTER}" = "${SSDPADDR%/*}" ]; then
		eerror "Found UPnP router on local machine!"
		return 1
	fi

	[ ${RET} -ne 0 ] && return ${RET}

	ebegin "Adding route through ${ROUTER}"
	_add_route -net default via "${ROUTER}" metric "${METRIC}" # dev ${IFACE} implicit
	RET=$?
	eend ${RET}

	einfo "External IP: ${MYIP}"

	return ${RET}
}

stop() {
	_checks || return $?
	_flush_routes
	return $?
}