#!/bin/bash
###############################################################################
#                                                                             #
# IPFire.org - A linux based firewall                                         #
# Copyright (C) 2012  IPFire Network Development Team                         #
#                                                                             #
# 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/>.       #
#                                                                             #
###############################################################################

# Sets the global wireless country code. Default is 00 = world.
WIRELESS_REGULATORY_DOMAIN="00"
NETWORK_SETTINGS_FILE_PARAMS="${NETWORK_SETTINGS_FILE_PARAMS} WIRELESS_REGULATORY_DOMAIN"

WIRELESS_REGULATORY_DOMAIN_DATABASE="/usr/lib/crda/regulatory.bin"

wireless_create() {
	local device=${1}
	assert isset device
	shift

	local address
	local channel
	local phy
	local type="managed"

	while [ $# -gt 0 ]; do
		case "${1}" in
			--address=*)
				address=$(cli_get_val ${1})
				;;
			--channel=*)
				channel=$(cli_get_val "${1}")
				;;
			--phy=*)
				phy=$(cli_get_val ${1})
				phy=$(phy_get ${phy})
				;;
			--type=*)
				type=$(cli_get_val ${1})

				# ap --> __ap
				[ "${type}" = "ap" ] && type="__ap"
				;;
			*)
				error "Unrecognized argument: ${1}"
				return ${EXIT_ERROR}
				;;
		esac
		shift
	done

	case "${type}" in
		ibss|managed|monitor|__ap)
			;;
		mesh-point)
			type="mp"
			;;
		*)
			log ERROR "Unknown type: ${type}"
			return ${EXIT_ERROR}
			;;

	esac

	assert phy_exists ${phy}
	isset address || address=$(mac_generate)

	cmd_quiet iw phy ${phy} interface add ${device} type ${type}
	local ret=$?

	if [ ${ret} -eq ${EXIT_OK} ]; then
		log DEBUG "created wireless device '${device}' (${type})"

		if isset address; then
			device_set_address ${device} ${address}
		fi
	else
		log ERROR "could not create wireless device '${device}' (${type}): ${ret}"
	fi

	# Set the channel
	if isset channel; then
		wireless_set_channel "${device}" "${channel}" || return $?
	fi

	return ${ret}
}

wireless_remove() {
	local device=${1}
	assert isset device

	if ! device_exists ${device}; then
		return ${EXIT_OK}
	fi

	# Tear down the device (if necessary).
	device_set_down ${device}

	# Remove it.
	cmd_quiet iw dev ${device} del
	local ret=$?

	if [ ${ret} -eq ${EXIT_OK} ]; then
		log DEBUG "removed wireless device '${device}'"
	else
		log ERROR "could not remove wireless device '${device}': ${ret}"
	fi

	return ${ret}
}

wireless_get_reg_domain() {
	# Returns the country code for the wireless device.
	# Defaults to 00 = world if unset.
	print "${WIRELESS_REGULATORY_DOMAIN:-00}"
}

wireless_init_reg_domain() {
	local country_code="$(wireless_get_reg_domain)"

	wireless_set_reg_domain "${country_code}" --no-reset
}

wireless_set_reg_domain() {
	local country_code
	local reset="true"

	while [ $# -gt 0 ]; do
		case "${1}" in
			--no-reset)
				reset="false"
				;;
			-*)
				log ERROR "Ignoring invalid option: ${1}"
				;;
			*)
				country_code="${1}"
				;;
		esac
		shift
	done

	# Check if configuration value is valid
	if ! wireless_valid_reg_domain "${country_code}"; then
		log ERROR "Invalid wireless regulatory domain: ${country_code}"
		return ${EXIT_ERROR}
	fi

	# Before the wireless reg domain is set, it helps to reset to 00 first.
	if enabled reset; then
		iw reg set 00 &>/dev/null
	fi

	log INFO "Setting wireless regulatory domain country to '${country_code}'"
	iw reg set "${country_code}"
}

wireless_valid_reg_domain() {
	local country_code="${1}"

	# Empty country codes are invalid
	isset country_code || return ${EXIT_FALSE}

	local valid_country_codes="$(wireless_list_reg_domains)"

	if list_match "${country_code}" ${valid_country_codes}; then
		return ${EXIT_TRUE}
	fi

	return ${EXIT_FALSE}
}

wireless_list_reg_domains() {
	if [ ! -r "${WIRELESS_REGULATORY_DOMAIN_DATABASE}" ]; then
		log ERROR "Could not read ${WIRELESS_REGULATORY_DOMAIN_DATABASE}"
		return ${EXIT_ERROR}
	fi

	local line
	while read line; do
		# Check if line starts with "country"
		[ "${line:0:7}" = "country" ] || continue

		# Print country code
		print "${line:8:2}"
	done <<< "$(regdbdump ${WIRELESS_REGULATORY_DOMAIN_DATABASE})"
}

wireless_channel_to_frequency() {
	# http://en.wikipedia.org/wiki/List_of_WLAN_channels

	local channel=${1}
	assert isset channel

	# Channel number must be positive.
	assert [ "${channel}" -gt 0 ]

	# 2.4 GHz band
	case "${channel}" in
		[123456789]|1[0123])
			print "$(( 2407 + (${channel} * 5)))"
			return ${EXIT_OK}
			;;
		14)
			print "2484"
			return ${EXIT_OK}
			;;
	esac

	# 5 GHz band
	case "${channel}" in
		3[68]|4[02468]|5[26]|6[04]|10[048]|11[26]|12[048]|13[26]|14[09]|15[37]|16[15])
			print "$(( 5000 + (${channel} * 5)))"
			return ${EXIT_OK}
			;;
	esac

	return ${EXIT_ERROR}
}

wireless_frequency_to_channel() {
	local frequency=${1}

	assert isinteger frequency

	# Everything that is too high
	if [ ${frequency} -gt 5825 ]; then
		return ${EXIT_ERROR}

	# 5 GHz Band
	elif [ ${frequency} -gt 5000 ]; then
		(( frequency = frequency - 5000 ))

		# Must be divisible by 5
		[ "$(( frequency % 5 ))" -ne 0 ] && return ${EXIT_ERROR}

		print "$(( frequency / 5 ))"

	# 2.4 GHz Band - Channel 14
	elif [ ${frequency} -eq 2484 ]; then
		print "14"

	# 2.4 GHz Band
	elif [ ${frequency} -gt 2407 ]; then
		(( frequency = frequency - 2407 ))

		# Must be divisible by 5
		[ "$(( frequency % 5 ))" -ne 0 ] && return ${EXIT_ERROR}

		print "$(( frequency / 5 ))"

	# Everything else
	else
		return ${EXIT_ERROR}
	fi

	return ${EXIT_OK}
}

wireless_set_channel() {
	local device=${1}
	assert isset device

	local channel=${2}
	assert isset channel

	device_exists ${device} || return ${EXIT_ERROR}

	log DEBUG "Setting wireless channel on device '${device}' to channel '${channel}'"
	cmd_quiet iw dev ${device} set channel ${channel}
}

wireless_ibss_join() {
	local device=${1}
	assert isset device
	shift

	local bssid
	local essid
	local frequency

	while [ $# -gt 0 ]; do
		case "${1}" in
			--bssid=*)
				bssid="$(cli_get_val ${1})"
				;;
			--essid=*)
				essid="$(cli_get_val ${1})"
				;;
			--channel=*)
				local channel="$(cli_get_val ${1})"

				# Save the frequency of the channel instead
				# of the channel itself.
				if isset channel; then
					frequency="$(wireless_channel_to_frequency ${channel})"
				fi
				;;
		esac
		shift
	done

	# Check input.
	assert ismac bssid
	assert isset essid
	assert isinteger frequency

	# Set device up.
	device_set_up "${device}"

	log INFO "${device} joining ibss network: ${essid} (${bssid})"
	cmd_quiet iw dev "${device}" ibss join "${essid}" \
		"${frequency}" fixed-freq "${bssid}"
}

wireless_ibss_leave() {
	local device=${1}
	assert isset device

	log INFO "${device} leaving ibss network"
	cmd_quiet iw dev "${device}" ibss leave
}

wireless_is_radar_frequency() {
	local frequency="${1}"
	assert isset frequency

	[[ ${frequency} -ge 5260 ]] && [[ ${frequency} -le 5700 ]]
}

wireless_monitor() {
	local device="${1}"
	assert isset device
	shift

	local monitor_device="$(port_find_free "${PORT_PATTERN_WIRELESS_MONITOR}")"

	# Create an 802.11 monitoring device
	wireless_create "${monitor_device}" --phy="${device}" --type="monitor"
	local ret=$?

	case "${ret}" in
		0)
			# Bring up the device
			device_set_up "${monitor_device}"

			# Starting tcpdump
			tcpdump -i "${monitor_device}" "$@"

			# Remove the monitoring interface.
			wireless_remove "${monitor_device}"
			;;

		*)
			log ERROR "Could not create a monitoring interface on ${device}"
			return ${EXIT_ERROR}
			;;
	esac

	return ${EXIT_OK}
}