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

. /lib/network/header-zone

# Modems support all authentication methods, that pppd does support.
MODEM_ALLOWED_AUTH_METHODS="${PPP_ALLOWED_AUTH_METHODS}"

HOOK_SETTINGS="HOOK"

# Access Point Name.
APN=
HOOK_SETTINGS="${HOOK_SETTINGS} APN"

# Sets the authentication algortihm that must be used.
AUTH=
HOOK_SETTINGS="${HOOK_SETTINGS} AUTH"

# Baudrate.
BAUDRATE=921600
HOOK_SETTINGS="${HOOK_SETTINGS} BAUDRATE"

# The device name of the serial device.
# XXX how can we make sure that this does not change all the time?
DEVICE=
HOOK_SETTINGS="${HOOK_SETTINGS} DEVICE"

# A monitor device.
# Send AT commands to this device, when the primary device is
# connected.
MONITOR_DEVICE=
HOOK_SETTINGS="${HOOK_SETTINGS} MONITOR_DEVICE"

# Maximum transmission unit.
MTU=1492
HOOK_SETTINGS="${HOOK_SETTINGS} MTU"

# User credentials.
USERNAME=
PASSWORD=
HOOK_SETTINGS="${HOOK_SETTINGS} USERNAME PASSWORD"

# PIN code.
PIN=
HOOK_SETTINGS="${HOOK_SETTINGS} PIN"

# Phone number.
PHONE_NUMBER=
HOOK_SETTINGS="${HOOK_SETTINGS} PHONE_NUMBER"

# IMSI
IMSI=
HOOK_SETTINGS="${HOOK_SETTINGS} IMSI"

function hook_check() {
	assert isset DEVICE
	assert isset PHONE_NUMBER

	# Make sure the PIN code is an integer, when set.
	if isset PIN; then
		assert isinteger PIN
		assert [ ${#PIN} -ge 4 ]
		assert [ ${#PIN} -le 8 ]
	fi

	assert isoneof BAUDRATE ${SERIAL_BAUDRATES}

	isset AUTH && assert isoneof AUTH ${MODEM_ALLOWED_AUTH_METHODS}
}

function hook_parse_cmdline() {
	local value

	while [ $# -gt 0 ]; do
		case "${1}" in
			--apn=*)
				APN=$(cli_get_val ${1})
				;;
			--auth=*)
				AUTH=$(cli_get_val ${1})
				;;
			--baudrate=*)
				BAUDRATE=$(cli_get_val ${1})
				assert isoneif "${BAUDRATE}" ${SERIAL_BAUDRATES}
				;;
			--device=*)
				DEVICE=$(cli_get_val ${1})
				;;
			--imsi=*)
				IMSI="$(cli_get_val "${1}")"
				;;
			--monitor-device=*)
				MONITOR_DEVICE=$(cli_get_val ${1})
				;;
			--mtu=*)
				MTU=$(cli_get_val ${1})
				assert isinteger ${MTU}
				;;
			--password=*)
				PASSWORD=$(cli_get_val ${1})
				;;
			--phone-number=*)
				PHONE_NUMBER=$(cli_get_val ${1})
				;;
			--pin=*)
				PIN=$(cli_get_val ${1})
				;;
			--username=*)
				USERNAME=$(cli_get_val ${1})
				;;
			*)
				echo "Unknown argument: ${1}" >&2
				exit ${EXIT_ERROR}
				;;
		esac
		shift
	done
}

function hook_up() {
	local zone=${1}
	assert isset zone

	# Load configuration file.
	zone_config_read ${zone}

	# If we have got a PIN, we try to unlock the device first.
	if isset PIN; then
		if ! modem_sim_auto_unlock "${DEVICE}" "${PIN}"; then
			# Reset the PIN setting.
			PIN=""
			config_write $(zone_dir ${zone})/settings ${HOOK_SETTINGS}
			error "Could not unlock the SIM card. Removing PIN from settings."
		fi

	# For mobile devices, check if a PIN is required although none is set.
	elif modem_is_mobile ${DEVICE} && modem_sim_locked ${DEVICE}; then
		error "The SIM card is locked. Please configure the PIN code."
		exit ${EXIT_ERROR}
	fi

	# Start the PPP daemon.
	pppd_start ${zone}

	exit ${EXIT_OK}
}

function hook_down() {
	local zone=${1}
	assert isset zone

	# Stop the PPP daemon.
	pppd_stop ${zone}

	exit ${EXIT_OK}
}

function hook_status() {
	local zone=${1}
	assert isset zone

	cli_device_headline ${zone}

	zone_config_read ${zone}

	cli_headline 2 "Configuration"
	cli_print_fmt1 2 "Username" "${USERNAME}"
	cli_print_fmt1 2 "Password" "<hidden>"
	cli_space

	cli_headline 2 "Device settings"
	cli_print_fmt1 2 "Device" "${DEVICE}"
	if isset MONITOR_DEVICE; then
		cli_print_fmt1 2 "Monitor device" "${MONITOR_DEVICE}"
	fi
	cli_print_fmt1 2 "Baudrate" "${BAUDRATE}"
	cli_print_fmt1 2 "MTU/MRU" "${MTU}"
	cli_space

	# Exit if zone is down
	if ! zone_is_up ${zone}; then
		echo # Empty line
		exit ${EXIT_ERROR}
	fi

	cli_headline 2 "Carrier network"

	# If the device and the monitor device are both locked,
	# we cannot show any carrier information.
	local device dev
	for dev in ${DEVICE} ${MONITOR_DEVICE}; do
		if ! serial_exists ${dev}; then
			continue
		fi
		if serial_is_locked ${dev}; then
			continue
		fi

		device=${dev}
	done

	if isset device; then
		cli_print_fmt1 2 "Operator" \
			"$(modem_get_network_operator ${device})"
		cli_print_fmt1 2 "SIM IMSI" \
			"$(modem_get_sim_imsi ${device})"
		cli_print_fmt1 2 "Mode" \
			"$(modem_get_network_mode ${device})"
		cli_print_fmt1 2 "Signal strength" \
			"$(modem_get_signal_quality ${device}) dBm"
		local ber=$(modem_get_bit_error_rate ${device})
		isset ber || ber="unknown"
		cli_print_fmt1 2 "Bit error rate" "${ber}"
	else
		cli_print 2 "Device is locked."
	fi
	cli_space

	# XXX display time since connection started

	cli_headline 2 "Point-to-Point-over-Ethernet protocol"
	local proto
	for proto in ${IP_SUPPORTED_PROTOCOLS}; do
		routing_db_exists ${zone} ${proto} || continue

		local headline
		case "${proto}" in
			ipv6)
				headline="Internet Protocol Version 6"
				;;
			ipv4)
				headline="Internet Protocol Version 4"
				;;
			*)
				headline="Unkown protocol"
				;;
		esac
		cli_headline 3 "${headline}"

		cli_print_fmt1 3 "IP address"  "$(routing_db_get ${zone} ${proto} local-ip-address)"
		cli_print_fmt1 3 "Gateway"     "$(routing_db_get ${zone} ${proto} remote-ip-address)"
		cli_print_fmt1 3 "DNS servers" "$(routing_db_get ${zone} ${proto} dns)"
		cli_space
	done

	exit ${EXIT_OK}
}

function hook_ppp_write_config() {
	local zone=${1}
	assert isset zone

	local file=${2}
	assert isset file

	# Read in the configuration files.
	zone_config_read ${zone}

	pppd_write_config ${file} \
		--interface="${zone}" \
		--username="${USERNAME}" \
		--password="${PASSWORD}" \
		--mtu="${MTU}" \
		--auth="${AUTH}" \
		\
		--serial="true" \
		--serial-device="${DEVICE}" \
		--baudrate="${BAUDRATE}" \
		--connect-command="/usr/lib/network/dialer ${zone}"

	exit ${EXIT_OK}
}