#!/bin/bash
###############################################################################
#                                                                             #
# IPFire.org - A linux based firewall                                         #
# Copyright (C) 2018  IPFire Network Development Team                         #
#                                                                             #
# This program is free software: you can redistribute it and/or modify        #
# it under the terms of the GNU General Public License as published by        #
# the Free Software Foundation, either version 3 of the License, or           #
# (at your option) any later version.                                         #
#                                                                             #
# This program is distributed in the hope that it will be useful,             #
# but WITHOUT ANY WARRANTY; without even the implied warranty of              #
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the               #
# GNU General Public License for more details.                                #
#                                                                             #
# You should have received a copy of the GNU General Public License           #
# along with this program.  If not, see <http://www.gnu.org/licenses/>.       #
#                                                                             #
###############################################################################

. /usr/lib/network/header-port

SUPPORTED_IP_TUNNEL_MODES="gretap"

HOOK_SETTINGS=(
	"ADDRESS"
	"MARK"
	"MODE"
	"PEER"
	"LOCAL_ADDRESS"
)

hook_check_settings() {
	assert isset MODE
	assert isoneof MODE ${SUPPORTED_IP_TUNNEL_MODES}

	assert isset ADDRESS
	assert mac_is_valid "${ADDRESS}"

	# Generate a random mark
	if ! isset MARK; then
		MARK="$(( ${RANDOM} & 0xffffffff ))"
	fi
}

hook_parse_cmdline() {
	while [ $# -gt 0 ]; do
		case "${1}" in
			--address=*)
				ADDRESS="$(cli_get_val "${1}")"

				if ! isset ADDRESS || ! mac_is_valid "${ADDRESS}"; then
					error "Invalid MAC address: ${ADDRESS}"
					return ${EXIT_ERROR}
				fi
				;;

			--local-address=*)
				LOCAL_ADDRESS="$(cli_get_val "${1}")"
				;;

			--mode=*)
				MODE="$(cli_get_val "${1}")"

				# MODE must be on the list of supported protocols
				if ! isoneof MODE ${SUPPORTED_IP_TUNNEL_MODES}; then
					error "Unsupported mode: ${mode}"
					return ${EXIT_ERROR}
				fi
				;;

			--peer=*)
				PEER="$(cli_get_val "${1}")"
				;;

			*)
				error "Unknown option: ${1}"
				return ${EXIT_ERROR}
				;;
		esac
		shift
	done

	# Generate a random MAC address if none is set
	if ! isset ADDRESS; then
		ADDRESS="$(mac_generate)"
	fi

	# If PEER is set, it must be a valid IP address
	if isset PEER && ! ip_is_valid "${PEER}"; then
		error "Peer ${PEER} is not a valid IP address"
		return ${EXIT_ERROR}
	fi

	# If LOCAL_ADDRESS is set, it must be a valid IP address
	# of the same protocol than PEER is
	if isset LOCAL_ADDRESS; then
		if ! ip_is_valid "${LOCAL_ADDRESS}"; then
			error "Local address ${LOCAL_ADDRESS} is not a valid IP address"
			return ${EXIT_ERROR}
		fi

		if ! ip_protocol_match "${PEER}" "${LOCAL_ADDRESS}"; then
			error "Peer and local address are of different IP protocols"
			return ${EXIT_ERROR}
		fi
	fi

	return ${EXIT_OK}
}

hook_create() {
	local port="${1}"
	assert isset port

	local ${HOOK_SETTINGS[*]}
	if ! port_settings_read "${port}"; then
		log ERROR "Could not read settings for port ${port}"
		return ${EXIT_ERROR}
	fi

	if ! ip_tunnel_add "${port}" \
			--mode="${MODE}" \
			--address="${ADDRESS}" \
			--remote-address="${PEER}" \
			--local-address="${LOCAL_ADDRESS}" \
			--ikey="${MARK}" \
			--okey="${MARK}"; then
		return ${EXIT_ERROR}
	fi

	exit ${EXIT_OK}
}

hook_remove() {
	local port="${1}"
	assert isset port

	# Remove the device
	if ! ip_tunnel_del "${port}"; then
		return ${EXIT_ERROR}
	fi

	exit ${EXIT_OK}
}

hook_hotplug_rename() {
	hook_hotplug_rename_by_address "$@"
}