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

PPP_SUPPORTED_AUTH_METHODS="chap pap"

function pppd_start() {
	local interface=${1}
	assert isset interface

	service_start "pppd@${interface}"
}

function pppd_stop() {
	local interface=${1}
	assert isset interface

	service_stop "pppd@${interface}"
}

function pppd_status() {
	local interface=${1}
	assert isset interface

	service_status "pppd@${interface}"
}

function ppp_common_ip_pre_up() {
	local zone=${1}
	shift

	if ! zone_exists ${zone}; then
		error "Zone '${zone}' does not exist."
		return ${EXIT_ERROR}
	fi

	routing_db_from_ppp ${zone} ipv4

	# Request firewall reload
	event_emit firewall-reload

	return ${EXIT_OK}
}

function ppp_common_ip_up() {
	local zone=${1}
	shift

	if ! zone_exists ${zone}; then
		error "Zone '${zone}' does not exist."
		return ${EXIT_ERROR}
	fi

	routing_db_set ${zone} ipv4 active 1
	routing_update ${zone} ipv4

	# Emit interface-up event
	event_interface_up ${zone}

	return ${EXIT_OK}
}

function ppp_common_ip_down() {
	local zone=${1}
	shift

	if ! zone_exists ${zone}; then
		error "Zone '${zone}' does not exist."
		return ${EXIT_ERROR}
	fi

	# Remove the information about this zone from the routing database
	# and update the routing table.
	routing_db_remove ${zone} ipv4
	routing_update ${zone} ipv4

	# Save accounting information
	ppp_accounting ${zone}

	# Emit interface-up event
	event_interface_down ${zone}

	return ${EXIT_OK}
}

function ppp_common_ipv6_up() {
	local zone=${1}
	shift

	if ! zone_exists ${zone}; then
		error "Zone '${zone}' does not exist."
		return ${EXIT_ERROR}
	fi

	# Add information about this zone to the routing database.
	routing_db_from_ppp ${zone} ipv6

	routing_db_set ${zone} ipv6 active 1
	routing_update ${zone} ipv6

	# Emit interface-up event
	event_interface_up ${zone}

	return ${EXIT_OK}
}

function ppp_common_ipv6_down() {
	local zone=${1}
	shift

	if ! zone_exists ${zone}; then
		error "Zone '${zone}' does not exist."
		return ${EXIT_ERROR}
	fi

	# Remove the information about this zone from the routing database
	# and update the routing table.
	routing_db_remove ${zone} ipv6
	routing_update ${zone} ipv6

	# Save accounting information
	ppp_accounting ${zone}

	# Emit interface-up event
	event_interface_down ${zone}

	return ${EXIT_OK}
}

function ppp_secret() {
	local USER=${1}
	local SECRET=${2}
	local a
	local secret
	local user

	# Updateing secret file
	> ${PPP_SECRETS}.tmp
	while read user a secret; do
		if [ "'${USER}'" != "${user}" ]; then
			echo "${user} ${a} ${secret}" >> ${PPP_SECRETS}.tmp
		fi
	done < ${PPP_SECRETS}
	echo "'${USER}' * '${SECRET}'" >> ${PPP_SECRETS}.tmp
	cat ${PPP_SECRETS}.tmp > ${PPP_SECRETS}
	rm -f ${PPP_SECRETS}.tmp
}

function ppp_accounting() {
	local zone=${1}
	shift

	db_ppp_update ${zone} --duration="${CONNECT_TIME}" \
		--rcvd="${BYTES_RCVD}" --sent="${BYTES_SENT}"
}

function pppd_exec() {
	log DEBUG "Running pppd with parameters '$@'."

	pppd $@ > /dev/null
}

function pppd_write_config() {
	local file=${1}; shift
	assert isset file

	local auth
	local interface
	local linkname
	local mtu mru
	local plugin plugin_options
	local user

	while [ $# -gt 0 ]; do
		case "${1}" in
			--auth=*)
				auth=$(cli_get_val ${1})
				;;
			# The name of the created ppp interface.
			--interface=*)
				interface=$(cli_get_val ${1})
				;;
			# Maximum Transmission Unit
			--mtu=*)
				mtu=$(cli_get_val ${1})
				;;
			# Maximum Receive Unit
			--mru=*)
				mru=$(cli_get_val ${1})
				;;
			--plugin=*)
				plugin=$(cli_get_val ${1})
				;;
			--plugin-options=*)
				plugin_options=$(cli_get_val ${1})
				;;
			--user=*)
				user=$(cli_get_val ${1})
				;;
			*)
				log WARNING "Unhandled argument: ${1}"
				;;
		esac
		shift
	done

	if [ -z "${interface}" ]; then
		log ERROR "You need to set the interface name: ${interface}"
		return ${EXIT_ERROR}
	fi
	linkname=${interface}

	if isset auth; then
		if ! isoneof ${auth} ${PPP_SUPPORTED_AUTH_METHODS}; then
			log ERROR "Unsupported auth method: ${auth}"
			return ${EXIT_ERROR}
		fi
	fi

	# Write the configuration header.
	mkdir -p $(dirname ${file}) 2>/dev/null
	config_header "PPP daemon configuration file" > ${file}

	# At first, set the name of the link.
	print "name ${linkname}\nlinkname ${linkname}\n" >> ${file}

	# Configure the interface name.
	print "# Interface name\nifname ${interface}\n" >> ${file}

	# Plugin settings
	if isset plugin; then
		(
			print "# Plugin settings"
			print "plugin ${plugin} ${plugin_options}"
			print
		) >> ${file}
	fi

	# User authentication
	if isset user; then
		(
			print "# User authentication"
			print "user ${user}"

			print "noauth"
			if isset auth; then
				print "require-${auth}"
			fi
			print
		) >> ${file}
	fi

	# MTU/MRU settings
	if isset mtu; then
		isset mru || mru=${mtu}

		(
			print "# MTU/MRU settings"
			print "mtu ${mtu}"
			print "mru ${mru}"
			print
		) >> ${file}
	fi

	# Add the default settings.
	(
		print "# Disable the compression"
		print "noccp noaccomp nodeflate nopcomp novj novjccomp nobsdcomp nomppe"

		print "noipdefault nodetach debug"
	) >> ${file}

	return ${EXIT_OK}
}