#!/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/>.       #
#                                                                             #
###############################################################################

HOOK_COMMANDS_CONFIG="hook_create hook_down hook_status hook_up"

HOOK_COMMANDS_PORT="hook_create hook_down hook_hotplug hook_hotplug_rename \
	hook_info hook_status hook_up"

HOOK_COMMANDS_ZONE="hook_add hook_create hook_discover hook_down hook_edit hook_help \
	hook_info hook_remove hook_status hook_up \
	\
	hook_config_create hook_config_edit hook_config_remove hook_config_show \
	\
	hook_port hook_port_add hook_port_edit hook_port_remove hook_port_show \
	hook_port_status hook_port_up hook_port_down \
	\
	hook_ppp_ip_pre_up hook_ppp_ipv4_down hook_ppp_ipv4_up \
	hook_ipv6_down hook_ipv6_up hook_ppp_write_config"

function hook_dir() {
	local type=${1}

	if [ -n "${type}" ]; then
		type="/${type}s"
	fi

	echo "${NETWORK_HOOKS_DIR}${type}"
}
NETWORK_HOOKS_DIR_ZONES="$(hook_dir zone)"

function hook_exists() {
	local type=${1}
	local hook=${2}

	assert isset type
	assert isset hook

	# Add the path prefix.
	hook="$(hook_dir ${type})/${hook}"

	[ ! -d "${hook}" ] && [ -x "${hook}" ]
}

function hook_exec() {
	local type="${1}"
	assert isset type

	local hook="${2}"
	assert isset hook

	local cmd="${3}"
	assert isset cmd

	assert hook_exists "${type}" "${hook}"
	shift 3

	# Complete the hook command by prepending "hook_"
	local hook_cmd="hook_${cmd}"

	# Check if the hook action is valid.
	local valid_commands
	case "${type}" in
		"config")
			valid_commands="${HOOK_COMMANDS_CONFIG}"
			;;
		"port")
			valid_commands="${HOOK_COMMANDS_PORT}"
			;;
		"zone")
			valid_commands="${HOOK_COMMANDS_ZONE}"
			;;
	esac
	isset valid_commands && assert list_match "${hook_cmd}" ${valid_commands}

	local hook_path="$(hook_dir ${type})/${hook}"

	# For performance reasons, all hooks are executed
	# in a subshell and so will inherit the currently
	# running environment.
	(
		# Set the name of the hook.
		HOOK=$(basename ${hook})

		# Source the code of the hook.
		source "${hook_path}"

		# Make sure HOOK is still properly set.
		assert isset HOOK

		# Execute the requested command.
		cmd "${hook_cmd}" "$@"
	)
	local ret=$?

	case "${ret}" in
		${EXIT_COMMAND_NOT_FOUND})
			log ERROR "Hook command not implemented: ${hook_command} ($@)"
			exit ${EXIT_COMMAND_NOT_FOUND}
			;;
		${EXIT_ERROR_ASSERT})
			log ERROR "Hook exited with an assertion error."
			exit ${EXIT_ERROR_ASSERT}
			;;
	esac

	return ${ret}
}

function config_get_hook() {
	local config=${1}

	assert isset config
	assert [ -e "${config}" ]

	(
		. ${config}
		echo "${HOOK}"
	)
}

function hook_zone_exists() {
	hook_exists zone $@
}

function hook_zone_port_exists() {
	local hook_zone=${1}
	local hook_port=${2}

	hook_exists zone "${hook_zone}.ports/${hook_port}"
}

function hook_zone_config_exists() {
	local hook_zone=${1}
	local hook_config=${2}

	hook_exists zone "${hook_zone}.configs/${hook_config}"
}

function hook_zone_has_ports() {
	local hook=${1}

	[ -d "${NETWORK_HOOKS_DIR_ZONES}/${hook}.ports" ]
}

function hook_zone_has_configs() {
	local hook=${1}

	[ -d "${NETWORK_HOOKS_DIR_ZONES}/${hook}.configs" ]
}

function hook_zone_exec() {
	hook_exec zone $@
}

function hook_zone_port_exec() {
	local hook_zone=${1}
	local hook_port=${2}
	shift 2

	hook_zone_exec "${hook_zone}.ports/${hook_port}" $@
}

function hook_zone_config_exec() {
	local hook_zone=${1}
	local hook_port=${2}
	shift 2

	hook_zone_exec "${hook_zone}.configs/${hook_port}" $@
}

function hook_zone_get_all() {
	local type=${1}

	local hook
	for hook in $(hook_dir zone)/*; do
		hook=$(basename ${hook})
		hook_zone_exists ${hook} && echo "${hook}"
	done
}

function hook_zone_ports_get_all() {
	local hook=${1}

	if ! hook_exists zone ${hook}; then
		error "Hook '${hook}' does not exist."
		return ${EXIT_ERROR}
	fi

	# If the zone hook has got no ports we exit silently
	if ! hook_zone_has_ports ${hook}; then
		return ${EXIT_OK}
	fi

	local h
	for h in $(hook_dir zone)/${hook}.ports/*; do
		h=$(basename ${h})
		if hook_zone_port_exists ${hook} ${h}; then
			echo "${h}"
		fi
	done
}

function hook_zone_configs_get_all() {
	local hook=${1}

	if ! hook_exists zone ${hook}; then
		error "Hook '${hook}' does not exist."
		return ${EXIT_ERROR}
	fi

	# If the zone hook has got no configurations we exit silently
	if ! hook_zone_has_configs ${hook}; then
		return ${EXIT_OK}
	fi

	local h
	for h in $(hook_dir zone)/${hook}.configs/*; do
		h=$(basename ${h})
		if hook_zone_config_exists ${hook} ${h}; then
			echo "${h}"
		fi
	done

	return ${EXIT_OK}
}