#!/bin/bash
###############################################################################
#                                                                             #
# IPFire.org - A linux based firewall                                         #
# Copyright (C) 2010  Michael Tremer & Christian Schmidt                      #
#                                                                             #
# 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-config

HOOK_SETTINGS="HOOK ADDRESS PREFIX GATEWAY"

function hook_check() {
	assert isset ADDRESS
	assert isinteger PREFIX

	if [ ${PREFIX} -gt 30 ]; then
		error "PREFIX is greater than 30."
		exit ${EXIT_ERROR}
	fi
}

function hook_create() {
	local zone="${1}"
	assert isset zone
	shift

	while [ $# -gt 0 ]; do
		case "${1}" in
			--address=*)
				ADDRESS=${1#--address=}
				;;
			--netmask=*)
				NETMASK=${1#--netmask=}
				;;
			--prefix=*)
				PREFIX=${1#--prefix=}
				;;
			--gateway=*)
				GATEWAY=${1#--gateway=}
				;;
		esac
		shift
	done

	if [ -z "${PREFIX}" -a -n "${NETMASK}" ]; then
		PREFIX=$(ipv4_mask_to_cidr ${NETMASK})
	fi

	# XXX maybe we can add some hashing to identify a configuration again
	zone_config_settings_write "${zone}" "${HOOK}.$(uuid)" ${HOOK_SETTINGS}

	exit ${EXIT_OK}
}

function hook_up() {
	local zone=${1}
	local config=${2}
	shift 2

	if ! device_exists ${zone}; then
		error "Zone '${zone}' doesn't exist."
		exit ${EXIT_ERROR}
	fi

	zone_config_settings_read "${zone}" "${config}" ${HOOK_SETTINGS}

	ip_address_add ${zone} ${ADDRESS}/${PREFIX}

	# Save configuration
	routing_db_set ${zone} ipv4 type "${HOOK}"
	routing_db_set ${zone} ipv4 local-ip-address "${ADDRESS}/${PREFIX}"
	routing_db_set ${zone} ipv4 remote-ip-address "${GATEWAY}"
	routing_db_set ${zone} ipv4 active 1

	routing_update ${zone} ipv4
	routing_default_update

	exit ${EXIT_OK}
}

function hook_down() {
	local zone=${1}
	local config=${2}
	shift 2

	if ! device_exists ${zone}; then
		error "Zone '${zone}' doesn't exist."
		exit ${EXIT_ERROR}
	fi
	
	zone_config_settings_read "${zone}" "${config}" ${HOOK_SETTINGS}

	ip_address_del ${zone} ${ADDRESS}/${PREFIX}

	# Update routing tables.
	routing_default_update

	exit ${EXIT_OK}
}

function hook_status() {
	local zone=${1}
	local config=${2}
	shift 2

	if ! device_exists ${zone}; then
		error "Zone '${zone}' doesn't exist."
		exit ${EXIT_ERROR}
	fi

	zone_config_settings_read "${zone}" "${config}" ${HOOK_SETTINGS}

	local status
	if zone_has_ip ${zone} ${ADDRESS}/${PREFIX}; then
		status=${MSG_HOOK_UP}
	else
		status=${MSG_HOOK_DOWN}
	fi
	cli_statusline 3 "${HOOK}" "${status}"

	cli_print_fmt1 3 "IPv4 address" "${ADDRESS}/${PREFIX}"
	if [ -n "${GATEWAY}" ]; then
		cli_print_fmt1 3 "Gateway" "${GATEWAY}"
	fi
	cli_space

	exit ${EXIT_OK}
}

function ipv4_mask_to_cidr() {
	local mask=0

	local field
	for field in $(tr '.' ' ' <<<${1}); do
		mask=$(( $(( ${mask} << 8 )) | ${field} ))
	done

	local cidr=0
	local x=$(( 128 << 24 )) # 0x80000000

	while [ $(( ${x} & ${mask} )) -ne 0 ]; do
		[ ${mask} -eq ${x} ] && mask=0 || mask=$(( ${mask} << 1 ))
		cidr=$((${cidr} + 1))
	done

	if [ $(( ${mask} & 2147483647 )) -ne 0 ]; then # 2147483647 = 0x7fffffff
		echo "Invalid net mask: $1" >&2
	else
		echo ${cidr}
	fi
}