#!/bin/bash
###############################################################################
#                                                                             #
# IPFire.org - A linux based firewall                                         #
# Copyright (C) 2011  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/functions

# Setup logging.
LOG_FACILITY="network-hotplug-serial"

# Associated hooks.
ASSOCIATED_HOOKS="modem"

# Read network settings
network_settings_read

log DEBUG "Called with ACTION='${ACTION}', DEVNAME='${DEVNAME}'."

# If DEVNAME is not set, we cannot handle anything here and will
# exit silently.
isset DEVNAME || exit ${EXIT_OK}

# Check if the udev environment variables are properly set.
assert isset ACTION

case "${ACTION}" in
	add|register)
		# Check if the device node already exists.
		if ! serial_exists ${DEVNAME}; then
			log DEBUG "Device node ${DEVNAME} does not exist"
			exit ${EXIT_ERROR}
		fi

		# USB modems often register multiple serial interfaces.
		# Some of them allow to send AT commands, some don't know.
		# However, there is only one interface that can actually be used
		# to connect to somewhere. This interface always runs in
		# interrupt mode. Exit for all interfaces, not in this mode.
		bus_type="$(serial_get_bus_type "${DEVNAME}")"
		if [ "${bus_type}" = "usb" ]; then
			# Find USB device.
			usb_device="$(usb_device_find_by_tty "${DEVNAME}")"

			# Find an interface in interrupt mode.
			if ! usb_device_has_interface_type_interrupt "${usb_device}"; then
				log DEBUG "USB device has no interface in interrupt mode: ${DEVNAME}"
				exit ${EXIT_OK}
			fi
		fi

		# Check if the device is actually a modem.
		if ! serial_is_modem ${DEVNAME}; then
			log DEBUG "${DEVNAME} does not look like a modem"
			exit ${EXIT_OK}
		fi

		# When we get here, the modem is alive and responds to
		# AT commands.
		log DEBUG "${DEVNAME} looks like a modem"

		# Initialize the modem here. Resets all established connections
		# and so on.
		modem_initialize "${DEVNAME}" --sleep=3

		# Unlock the SIM card if it has one.
		if modem_sim_locked "${DEVNAME}"; then
			log ERROR "SIM card is locked. Needs unlocking."
			exit ${EXIT_OK}
		fi

		# Try to find the zone configuration by the IMSI of the
		# SIM card.
		sim_imsi="$(modem_get_sim_imsi "${DEVNAME}")"
		isset sim_imsi || exit ${EXIT_OK}

		for zone in $(zones_get_all); do
			# Skip zones that are not enabled for auto-start.
			if ! zone_is_enabled "${zone}"; then
				continue
			fi

			# Skip unsupported hook types.
			hook="$(zone_get_hook "${zone}")"
			list_match "${hook}" ${ASSOCIATED_HOOKS} || continue

			# Read IMSI from zone configuration.
			zone_imsi="$(zone_settings_get "${zone}" IMSI)"

			# If IMSIs match, we start that zone.
			if [ "${zone_imsi}" = "${sim_imsi}" ]; then
				# Start the matching zone.
				zone_up "${zone}"
				break
			fi
		done

		exit ${EXIT_OK}
		;;

	remove|unregister)
		# After the interface has been removed/unplugged,
		# there are often daemons (like pppd) which need
		# to be stopped.
		;;
esac

exit ${EXIT_OK}