#!/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_dir() {
	local type=${1}

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

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

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}" ]
}

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.
	assert hook_valid_command "${type}" "${cmd}"

	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.
		"${hook_cmd}" "$@"
	)
	local ret=$?

	case "${ret}" in
		${EXIT_COMMAND_NOT_FOUND}|${EXIT_NOT_SUPPORTED})
			log ERROR "Hook '${hook}' does not implement the method '${cmd}':"
			log ERROR "  arguments: $@"
			return ${EXIT_COMMAND_NOT_FOUND}
			;;
		${EXIT_ERROR_ASSERT})
			log ERROR "Hook exited with an assertion error."
			return ${EXIT_ERROR_ASSERT}
			;;
	esac

	return ${ret}
}

hook_list() {
	local type="${1}"

	local dir="$(hook_dir "${type}")"
	assert isset dir

	local hook
	for hook in $(list_directory "${dir}"); do
		if hook_exists "${type}" "${hook}"; then
			echo "${hook}"
		fi
	done
}

# The default help function.
hook_help() {
	# If no man page has been configured, we print an error message.
	if [ -z "${HOOK_MANPAGE}" ]; then
		error "There is no help available for hook '${HOOK}'. Exiting."
		exit ${EXIT_ERROR}
	fi

	cli_show_man "${HOOK_MANPAGE}"

	exit $?
}

config_get_hook() {
	local config=${1}

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

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

hook_zone_exists() {
	hook_exists zone "$@"
}

hook_zone_exec() {
	hook_exec zone "$@"
}

hook_zone_get_all() {
	hook_list zone
}

hook_config_exists() {
	hook_exists config "$@"
}

hook_config_exec() {
	hook_exec config "$@"
}

hook_config_get_all() {
	hook_list config
}

hook_valid_command() {
	local type="${1}"
	local cmd="${2}"

	case "${type}" in
		config)
			hook_valid_command_config "${cmd}"
			return ${?}
			;;
		port)
			hook_valid_command_port "${cmd}"
			return ${?}
			;;
		zone)
			hook_valid_command_zone "${cmd}"
			return ${?}
			;;
	esac

	return ${EXIT_FALSE}
}

hook_valid_command_config() {
	local cmd="${1}"

	case "${cmd}" in
		new|destroy|edit|up|down|status|hid)
			return ${EXIT_TRUE}
			;;
	esac

	return ${EXIT_FALSE}
}

hook_valid_command_port() {
	local cmd="${1}"

	case "${cmd}" in
		# Configuration hooks
		new|edit|destroy)
			return ${EXIT_TRUE}
			;;

		# Control hooks
		create|remove|up|down)
			return ${EXIT_TRUE}
			;;

		# Hotplug
		hotplug|hotplug_rename)
			return ${EXIT_TRUE}
			;;

		# Status
		status|children)
			return ${EXIT_TRUE}
			;;
	esac

	return ${EXIT_FALSE}
}

hook_valid_command_zone() {
	local cmd="${1}"

	case "${cmd}" in
		# Configuration hooks
		new|edit|destroy)
			return ${EXIT_TRUE}
			;;

		config_new|config_destroy|config_edit|config_show)
			return ${EXIT_TRUE}
			;;

		# Control hooks
		up|down)
			return ${EXIT_TRUE}
			;;

		# Hotplug
		hotplug)
			return ${EXIT_TRUE}
			;;

		# Ports
		port_attach|port_detach|port_edit|port_create|port_remove|port_status|port_up|port_down)
			return ${EXIT_TRUE}
			;;

		# Status
		status|info|help)
			return ${EXIT_TRUE}
			;;

		# Discovery
		discover)
			return ${EXIT_TRUE}
			;;

		# PPP
		ppp_ip_pre_up|ppp_ipv[64]_up|ppp_ipv[64]_down|ppp_write_config)
			return ${EXIT_TRUE}
			;;
	esac

	return ${EXIT_FALSE}
}