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

# A list of supported versions of the IP protocol
IP_SUPPORTED_PROTOCOLS=""

ip_split_prefix() {
	local address=${1}
	assert isset address

	echo "${address%%/*}"
}

ip_get_prefix() {
	local address=${1}
	assert isset address

	# Break if no prefix is provided
	[[ ${address} =~ \/ ]] || return ${EXIT_OK}

	echo "${address##*/}"
}

ip_detect_protocol() {
	local address="${1}"
	assert isset address

	# Remove prefix so that we can handle subnet, too
	address=$(ip_split_prefix ${address})

	local protocol
	for protocol in ${IP_SUPPORTED_PROTOCOLS}; do
		if ${protocol}_is_valid "${address}"; then
			echo "${protocol}"
			return ${EXIT_OK}
		fi
	done

	return ${EXIT_ERROR}
}

ip_protocol_is_supported() {
	local proto=${1}

	assert isset proto

	list_match ${proto} ${IP_SUPPORTED_PROTOCOLS}
}

# Returns true if all IP addresses are of the same protocol
ip_protocol_match() {
	local address="${1}"
	shift

	# Get protocol of the first address
	local protocol="$(ip_detect_protocol "${address}")"

	# Check if all other addresses match the protocol
	for address in $@; do
		local p="$(ip_detect_protocol "${address}")"

		if [ "${p}" != "${protocol}" ]; then
			return ${EXIT_FALSE}
		fi
	done

	return ${EXIT_TRUE}
}

ip_is_valid() {
	local address=${1}
	assert isset address

	local protocol
	for protocol in ${IP_SUPPORTED_PROTOCOLS}; do
		if ${protocol}_is_valid "${address}"; then
			return ${EXIT_TRUE}
		fi
	done

	return ${EXIT_FALSE}
}

ip_net_is_valid() {
	local network=${1}
	assert isset network

	local protocol
	for protocol in ${IP_SUPPORTED_PROTOCOLS}; do
		if ${protocol}_net_is_valid "${network}"; then
			return ${EXIT_TRUE}
		fi
	done

	return ${EXIT_FALSE}
}

ip_prefix_is_valid() {
	local proto=${1}
	assert isset proto

	local prefix=${2}

	case "${proto}" in
		ipv4)
			ipv4_prefix_is_valid ${prefix}
			return $?
			;;
		ipv6)
			ipv6_prefix_is_valid ${prefix}
			return $?
			;;
	esac

	assert ip_protocol_is_supported ${proto}
}

ip_get_network() {
	inetcalc -n "$@" && return ${EXIT_OK} || return ${EXIT_ERROR}
}

ip_network_is_subset_of() {
	assert [ $# -eq 2 ]

	inetcalc -s "$@" && return ${EXIT_TRUE} || return ${EXIT_FALSE}
}

ip_address_add() {
	local device=${1}
	local address=${2}

	assert isset address
	assert device_exists ${device}

	local prefix=$(ip_get_prefix ${address})
	address=$(ip_split_prefix ${address})

	assert isset prefix
	assert isset address

	echo "ADDRESS = $address"

	# Detect the protocol version
	local protocol=$(ip_detect_protocol "${address}")
	assert ip_protocol_is_supported "${protocol}"

	case "${protocol}" in
		ipv6)
			assert ipv6_prefix_is_valid "${prefix}"
			;;
		ipv4)
			assert ipv4_prefix_is_valid "${prefix}"
			;;
	esac

	case "${protocol}" in
		ipv4)
			if ipv4_detect_duplicate ${device} ${address}; then
				error_log "Duplicate address detected on zone '${device}' (${address})."
				error_log "Cannot continue."
				return ${EXIT_ERROR}
			fi
			;;
	esac

	if ! device_has_ip ${device} ${address}/${prefix}; then
		assert ip addr add ${address}/${prefix} dev ${device}

		log DEBUG "IP address '${address}' (${protocol}) was successfully configured on device '${device}'."

		case "${protocol}" in
			ipv4)
				# Announce our new address to the neighbours
				ipv4_update_neighbours ${device} ${address}
				;;
		esac
	else
		log DEBUG "IP address '${address}' (${protocol}) was already configured on device '${device}'."
	fi

	return ${EXIT_OK}
}

ip_address_del() {
	local device=${1}
	local address=${2}

	assert isset address
	assert device_exists ${device}

	local prefix=$(ip_get_prefix ${address})
	address=$(ip_split_prefix ${address})

	assert isset prefix

	# Detect the protocol version
	local protocol=$(ip_detect_protocol "${address}")
	assert ip_protocol_is_supported "${protocol}"

	if device_has_ip ${device} ${address}/${prefix}; then
		assert ip addr del ${address}/${prefix} dev ${device}

		log DEBUG "IP address '${address}' (${protocol}) was successfully removed from device '${device}'."
	else
		log DEBUG "IP address '${address}' (${protocol}) was not configured on device '${device}'."
	fi

	return ${EXIT_OK}
}

# Get all currently assigned addresse for a given network
ip_get_assigned_addresses_from_net() {
	local net=${1}
	shift
	local args="$@"

	if ! ip_net_is_valid ${net}; then
		log ERROR "IP net ${net} is invalid"
		return ${EXIT_ERROR}
	fi

	local line
	local addresses

	# We read the output of $(ip addr show to ${net} ${args})
	while read -r line; do
		# We are only interested in lines which start with inet or inet6
		[[ "${line}" =~ ^(inet6 |inet ) ]] || continue

		# We need the second word the line
		line=(${line})
		list_append "addresses" "$(ip_split_prefix "${line[1]}")"
	done <<< "$(ip addr show to "${net}" ${args})"

	# We sort the list to get the lowest IP as first item
	list_sort ${addresses}
}