[people/stevee/network.git] / src / functions / functions.ipsec

#!/bin/bash
###############################################################################
#                                                                             #
# IPFire.org - A linux based firewall                                         #
# Copyright (C) 2017  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/>.       #
#                                                                             #
###############################################################################

IPSEC_CONNECTION_CONFIG_SETTINGS="\
	AUTH_MODE \
	DPD_ACTION \
	DPD_DELAY \
	DPD_TIMEOUT \
	INACTIVITY_TIMEOUT \
	LOCAL_ADDRESS \
	LOCAL_ID \
	LOCAL_PREFIX \
	MODE \
	PEER \
	PSK \
	REMOTE_ID \
	REMOTE_PREFIX \
	SECURITY_POLICY \
	ENABLED"

# Default values
IPSEC_DEFAULT_AUTH_MODE="PSK"
IPSEC_DEFAULT_DPD_ACTION="restart"
IPSEC_DEFAULT_DPD_DELAY="30"
IPSEC_DEFAULT_DPD_TIMEOUT="120"
IPSEC_DEFAULT_ENABLED="true"
IPSEC_DEFAULT_INACTIVITY_TIMEOUT="0"
IPSEC_DEFAULT_MODE="tunnel"
IPSEC_DEFAULT_SECURITY_POLICY="system"
IPSEC_DEFAULT_START_ACTION="on-demand"

IPSEC_VALID_MODES="gre-transport tunnel vti"
IPSEC_VALID_AUTH_MODES="PSK"

cli_ipsec() {
	local action=${1}
	shift 1

	case "${action}" in
		connection)
			cli_ipsec_connection $@
			;;
		*)
			error "Unrecognized argument: ${action}"
			exit ${EXIT_ERROR}
			;;
	esac
}

cli_ipsec_connection() {
	if ipsec_connection_exists ${1}; then
		local connection=${1}
		local key=${2}
		key=${key//-/_}
		shift 2

		case "${key}" in
			authentication|down|disable|dpd|enable|inactivity_timeout|local|mode|peer|remote|security_policy|start_action|up)
				ipsec_connection_${key} ${connection} $@
				;;
			show)
				cli_ipsec_connection_show "${connection}"
				exit $?
				;;
			*)
				error "Unrecognized argument: ${key}"
				exit ${EXIT_ERROR}
				;;
		esac
	else
		local action=${1}
		shift

		case "${action}" in
			new)
				ipsec_connection_new $@
				;;
			destroy)
				ipsec_connection_destroy $@
				;;
			""|*)
				if [ -n "${action}" ]; then
					error "Unrecognized argument: '${action}'"
				fi
				exit ${EXIT_ERROR}
				;;
		esac
	fi
}

cli_ipsec_connection_show() {
	local connection="${1}"

	# Read the config settings
	local ${IPSEC_CONNECTION_CONFIG_SETTINGS}
	if ! ipsec_connection_read_config "${connection}"; then
		error "Could not read the connection configuration"
		return ${EXIT_ERROR}
	fi

	cli_headline 0 "IPsec VPN Connection: ${connection}"
	cli_space

	# Peer
	if isset PEER; then
		cli_print_fmt1 1 "Peer" "${PEER}"
	fi

	# Security Policy
	cli_print_fmt1 1 "Security Policy" "${SECURITY_POLICY-${IPSEC_DEFAULT_SECURITY_POLICY}}"
	cli_space

	cli_headline 2 "Authentication"
	case "${AUTH_MODE^^}" in
		PSK)
			cli_print_fmt1 2 "Mode" "Pre-Shared-Key"

			if isset PSK; then
				cli_print_fmt1 2 "Pre-Shared-Key" "****"
			else
				cli_print_fmt1 2 "Pre-Shared-Key" "- is not set -"
			fi
			;;
		X509)
			: # TODO
			;;
	esac
	cli_space

	local i
	for i in LOCAL REMOTE; do
		case "${i}" in
			LOCAL)
				cli_headline 2 "Local"
				;;
			REMOTE)
				cli_headline 2 "Remote"
				;;
		esac

		local id_var="${i}_ID"
		if [ -n "${!id_var}" ]; then
			cli_print_fmt1 2 "ID" "${!id_var}"
		fi

		local prefix_var="${i}_PREFIX"
		if isset ${prefix_var}; then
			cli_headline 3 "Prefix(es)"

			local prefix
			for prefix in ${!prefix_var}; do
				cli_print_fmt1 3 "${prefix}"
			done
		fi

		cli_space
	done

	cli_headline 2 "Misc."

	case "${MODE}" in
		gre-transport)
			cli_print_fmt1 2 "Transport Mode" "GRE Transport"
			;;
		tunnel)
			cli_print_fmt1 2 "Transport Mode" "Tunnel"
			;;
		vti)
			cli_print_fmt1 2 "Transport Mode" "Virtual Tunnel Interface"
			;;
		*)
			cli_print_fmt1 2 "Transport Mode" "- Unknown -"
			;;
	esac

	# Inactivity timeout
	if isset INACTIVITY_TIMEOUT && [ ${INACTIVITY_TIMEOUT} -gt 0 ]; then
		cli_print_fmt1 2 "Inactivity Timeout" "$(format_time ${INACTIVITY_TIMEOUT})"
	fi
	cli_space

	return ${EXIT_OK}
}

ipsec_connection_disable() {
	local connection=${1}

	if ! ipsec_connection_write_config_key "${connection}" "ENABLED" "false"; then
		log ERROR "Could not write configuration settings"
		return ${EXIT_ERROR}
	fi

	ipsec_reload ${connection}
}

ipsec_connection_enable() {
	local connection=${1}

	if ! ipsec_connection_write_config_key "${connection}" "ENABLED" "true"; then
		log ERROR "Could not write configuration settings"
		return ${EXIT_ERROR}
	fi

	ipsec_reload "${connection}"
}

# This function writes all values to a via ${connection} specificated VPN IPsec configuration file
ipsec_connection_write_config() {
	assert [ $# -ge 1 ]

	local connection="${1}"

	if ! ipsec_connection_exists "${connection}"; then
		log ERROR "No such VPN IPsec connection: ${connection}"
		return ${EXIT_ERROR}
	fi

	local path="${NETWORK_IPSEC_CONNS_DIR}/${connection}/settings"

	if ! settings_write "${path}" ${IPSEC_CONNECTION_CONFIG_SETTINGS}; then
		log ERROR "Could not write configuration settings for VPN IPsec connection ${connection}"
		return ${EXIT_ERROR}
	fi

	ipsec_reload ${connection}
}

# This funtion writes the value for one key to a via ${connection} specificated VPN IPsec connection configuration file
ipsec_connection_write_config_key() {
	assert [ $# -ge 3 ]

	local connection=${1}
	local key=${2}
	shift 2

	local value="$@"

	if ! ipsec_connection_exists "${connection}"; then
		log ERROR "No such VPN ipsec connection: ${connection}"
		return ${EXIT_ERROR}
	fi

	log DEBUG "Set '${key}' to new value '${value}' in VPN ipsec connection '${connection}'"

	local ${IPSEC_CONNECTION_CONFIG_SETTINGS}

	# Read the config settings
	if ! ipsec_connection_read_config "${connection}"; then
		return ${EXIT_ERROR}
	fi

	# Set the key to a new value
	assign "${key}" "${value}"

	if ! ipsec_connection_write_config "${connection}"; then
		return ${EXIT_ERROR}
	fi

	return ${EXIT_TRUE}
}

# Reads one or more keys out of a settings file or all if no key is provided.
ipsec_connection_read_config() {
	assert [ $# -ge 1 ]

	local connection="${1}"
	shift 1

	if ! ipsec_connection_exists "${connection}"; then
		log ERROR "No such VPN IPsec connection : ${connection}"
		return ${EXIT_ERROR}
	fi


	local args
	if [ $# -eq 0 ] && [ -n "${IPSEC_CONNECTION_CONFIG_SETTINGS}" ]; then
		list_append args ${IPSEC_CONNECTION_CONFIG_SETTINGS}
	else
		list_append args $@
	fi

	local path="${NETWORK_IPSEC_CONNS_DIR}/${connection}/settings"

	if ! settings_read "${path}" ${args}; then
		log ERROR "Could not read settings for VPN IPsec connection ${connection}"
		return ${EXIT_ERROR}
	fi
}

# This function checks if a vpn ipsec connection exists
# Returns True when yes and false when not
ipsec_connection_exists() {
	assert [ $# -eq 1 ]

	local connection=${1}

	local path="${NETWORK_IPSEC_CONNS_DIR}/${connection}"

	[ -d "${path}" ] && return ${EXIT_TRUE} || return ${EXIT_FALSE}
}

ipsec_strongswan_load() {
	if ! cmd swanctl --load-all; then
		log ERROR "Could not reload strongswan config"
		return ${EXIT_ERROR}
	fi
}

# Reloads the connection after config changes
ipsec_reload() {
	local connection=${1}

	local ENABLED

	if ! ipsec_connection_read_config "${connection}" "ENABLED"; then
		log ERROR "Could not read configuration for IPsec connection ${connection}"
		return ${EXIT_ERROR}
	fi

	if enabled ${ENABLED}; then
		if ! ipsec_connection_to_strongswan ${connection}; then
			log ERROR "Could not generate strongswan config for ${connnection}"
			return ${EXIT_ERROR}
		fi
	else
		unlink "${NETWORK_IPSEC_SWANCTL_CONNECTIONS_DIR}/${connection}.conf"
	fi

	ipsec_strongswan_load
}

# Handle the cli after authentification
ipsec_connection_authentication() {
	if [ ! $# -gt 1 ]; then
		log ERROR "Not enough arguments"
		return ${EXIT_ERROR}
	fi

	local connection=${1}
	local cmd=${2}
	shift 2

	case ${cmd} in
		mode)
			ipsec_connection_authentication_mode "${connection}" $@
			;;
		pre-shared-key)
			ipsec_connection_authentication_psk "${connection}" $@
			;;
		*)
			log ERROR "Unrecognized argument: ${cmd}"
			return ${EXIT_ERROR}
			;;
	esac
}

# Set the authentification mode
ipsec_connection_authentication_mode() {
	if [ ! $# -eq 2 ]; then
		log ERROR "Not enough arguments"
		return ${EXIT_ERROR}
	fi
	local connection=${1}
	local mode=${2}

	if ! isoneof mode ${IPSEC_VALID_AUTH_MODES}; then
		log ERROR "Auth mode '${mode}' is invalid"
		return ${EXIT_ERROR}
	fi

	if ! ipsec_connection_write_config_key "${connection}" "AUTH_MODE" ${mode^^}; then
		log ERROR "Could not write configuration settings"
		return ${EXIT_ERROR}
	fi
}

# Set the psk
ipsec_connection_authentication_psk() {
	if [ ! $# -eq 2 ]; then
		log ERROR "Not enough arguments"
		return ${EXIT_ERROR}
	fi

	local connection=${1}
	local psk=${2}

	local length=${#psk}

	if [ ${length} -lt 4 ]; then
		error "The PSK must be longer than four characters"
		return ${EXIT_ERROR}
	fi

	if [ ${length} -gt 128 ]; then
		error "The PSK cannot be longer than 128 characters"
		return ${EXIT_ERROR}
	fi

	if ! ipsec_connection_write_config_key "${connection}" "PSK" "${psk}"; then
		log ERROR "Could not write configuration settings"
		return ${EXIT_ERROR}
	fi

	return ${EXIT_OK}
}

ipsec_connection_up() {
	local connection="${1}"

	if ! ipsec_connection_exists "${connection}"; then
		error "No such VPN IPsec connection: ${connection}"
		return ${EXIT_ERROR}
	fi

	cmd swanctl --initiate --child "${connection}"
}

ipsec_connection_down() {
	local connection="${1}"

	if ! ipsec_connection_exists "${connection}"; then
		error "No such VPN IPsec connection: ${connection}"
		return ${EXIT_ERROR}
	fi

	cmd swanctl --terminate --ike "${connection}"
}

# Handle the cli after authentification
ipsec_connection_dpd() {
	if [ ! $# -gt 1 ]; then
		log ERROR "Not enough arguments"
		return ${EXIT_ERROR}
	fi

	local connection=${1}
	local cmd=${2}
	shift 2

	case ${cmd} in
		action)
			ipsec_connection_dpd_action "${connection}" $@
			;;
		delay)
			ipsec_connection_dpd_delay "${connection}" $@
			;;
		timeout)
			ipsec_connection_dpd_timeout "${connection}" $@
			;;
		*)
			log ERROR "Unrecognized argument: ${cmd}"
			return ${EXIT_ERROR}
			;;
	esac
}

# Set the default dpd action
ipsec_connection_dpd_action() {
	if [ ! $# -eq 2 ]; then
		log ERROR "Not enough arguments"
		return ${EXIT_ERROR}
	fi
	local connection=${1}
	local action=${2}

	if ! isoneof action "restart" "clear"; then
		log ERROR "dpd action '${action}' is invalid"
		return ${EXIT_ERROR}
	fi

	if ! ipsec_connection_write_config_key "${connection}" "DPD_ACTION" ${action}; then
		log ERROR "Could not write configuration settings"
		return ${EXIT_ERROR}
	fi
}

# Set the dpd delay
ipsec_connection_dpd_delay() {
	if [ ! $# -ge 2 ]; then
		log ERROR "Not enough arguments"
		return ${EXIT_ERROR}
	fi

	local connection=${1}
	shift 1
	local value=$@

	if ! isinteger value; then
		value=$(parse_time $@)
		if [ ! $? -eq 0 ]; then
			log ERROR "Parsing the passed time was not sucessful please check the passed values."
			return ${EXIT_ERROR}
		fi
	fi

	if [ ${value} -lt 0 ]; then
		log ERROR "The passed time value must be in the sum greater or equal zero seconds."
		return ${EXIT_ERROR}
	fi

	if ! ipsec_connection_write_config_key "${connection}" "DPD_DELAY" ${value}; then
		log ERROR "Could not write configuration settings"
		return ${EXIT_ERROR}
	fi

	return ${EXIT_OK}
}

# Set the dpd timeout
ipsec_connection_dpd_timeout() {
	if [ ! $# -ge 2 ]; then
		log ERROR "Not enough arguments"
		return ${EXIT_ERROR}
	fi

	local connection=${1}
	shift 1
	local value=$@

	if ! isinteger value; then
		value=$(parse_time $@)
		if [ ! $? -eq 0 ]; then
			log ERROR "Parsing the passed time was not sucessful please check the passed values."
			return ${EXIT_ERROR}
		fi
	fi

	if [ ${value} -le 0 ]; then
		log ERROR "The passed time value must be in the sum greater or equal zero seconds."
		return ${EXIT_ERROR}
	fi

	if ! ipsec_connection_write_config_key "${connection}" "DPD_TIMEOUT" ${value}; then
		log ERROR "Could not write configuration settings"
		return ${EXIT_ERROR}
	fi

	return ${EXIT_OK}
}

# Handle the cli after local
ipsec_connection_local() {
	if [ ! $# -ge 2 ]; then
		log ERROR "Not enough arguments"
		return ${EXIT_ERROR}
	fi

	local connection=${1}
	local cmd=${2}
	shift 2

	case ${cmd} in
		address)
			ipsec_connection_local_address "${connection}" $@
			;;
		id)
			ipsec_connection_id "${connection}" "LOCAL" $@
			;;
		prefix)
			ipsec_connection_prefix "${connection}" "LOCAL" $@
			;;
		*)
			log ERROR "Unrecognized argument: ${cmd}"
			return ${EXIT_ERROR}
			;;
	esac

	return ${EXIT_OK}
}

# Set the connection mode
ipsec_connection_mode() {
	if [ ! $# -eq 2 ]; then
		log ERROR "Not enough arguments"
		return ${EXIT_ERROR}
	fi
	local connection=${1}
	local mode=${2}

	if ! isoneof mode ${IPSEC_VALID_MODES}; then
		log ERROR "Mode '${mode}' is invalid"
		return ${EXIT_ERROR}
	fi

	if ! ipsec_connection_write_config_key "${connection}" "MODE" ${mode}; then
		log ERROR "Could not write configuration settings"
		return ${EXIT_ERROR}
	fi

	return ${EXIT_OK}
}

# Set the local address
ipsec_connection_local_address() {
	if [ ! $# -eq 2 ]; then
		log ERROR "Not enough arguments"
		return ${EXIT_ERROR}
	fi
	local connection=${1}
	local local_address=${2}

	if ! ipsec_connection_check_peer ${local_address}; then
		log ERROR "Local address '${local_address}' is invalid"
		return ${EXIT_ERROR}
	fi

	if ! ipsec_connection_write_config_key "${connection}" "LOCAL_ADDRESS" ${local_address}; then
		log ERROR "Could not write configuration settings"
		return ${EXIT_ERROR}
	fi

	return ${EXIT_OK}
}

# Set the peer to connect to
ipsec_connection_peer() {
	if [ ! $# -eq 2 ]; then
		log ERROR "Not enough arguments"
		return ${EXIT_ERROR}
	fi
	local connection=${1}
	local peer=${2}

	if ! ipsec_connection_check_peer ${peer}; then
		log ERROR "Peer '${peer}' is invalid"
		return ${EXIT_ERROR}
	fi

	if ! ipsec_connection_write_config_key "${connection}" "PEER" ${peer}; then
		log ERROR "Could not write configuration settings"
		return ${EXIT_ERROR}
	fi

	return ${EXIT_OK}
}

#Set the local or remote id
ipsec_connection_id() {
	if [ ! $# -eq 3 ]; then
		log ERROR "Not enough arguments"
		return ${EXIT_ERROR}
	fi
	local connection=${1}
	local type=${2}
	local id=${3}

	if ! ipsec_connection_check_id ${id}; then
		log ERROR "Id '${id}' is invalid"
		return ${EXIT_ERROR}
	fi
	
	if ! ipsec_connection_write_config_key "${connection}" "${type}_ID" ${id}; then
		log ERROR "Could not write configuration settings"
		return ${EXIT_ERROR}
	fi
	
	return ${EXIT_OK}
}

# Set the local or remote prefix 
ipsec_connection_prefix() {
	if [ ! $# -ge 3 ]; then
		log ERROR "Not enough arguments"
		return ${EXIT_ERROR}
	fi
	local connection=${1}
	local type=${2}
	shift 2
	
	local _prefix="${type}_PREFIX"
	local "${_prefix}"
	if ! ipsec_connection_read_config "${connection}" "${_prefix}"; then
		return ${EXIT_ERROR}
	fi

	# Remove duplicated entries to proceed the list safely
	assign "${_prefix}" "$(list_unique ${!_prefix} )"

	local prefixes_added
	local prefixes_removed
	local prefixes_set

	while [ $# -gt 0 ]; do
		local arg="${1}"

		case "${arg}" in
			+*)
				list_append prefixes_added "${arg:1}"
				;;
			-*)
				list_append prefixes_removed "${arg:1}"
				;;
			[A-Fa-f0-9]*)
				list_append prefixes_set "${arg}"
				;;
			*)
				error "Invalid argument: ${arg}"
				return ${EXIT_ERROR}
				;;
		esac
		shift
	done

	# Check if the user is trying a mixed operation
	if ! list_is_empty prefixes_set && (! list_is_empty prefixes_added || ! list_is_empty prefixes_removed); then
		error "You cannot reset the prefix list and add or remove prefixes at the same time"
		return ${EXIT_ERROR}
	fi

	# Set new prefix list
	if ! list_is_empty prefixes_set; then
		# Check if all prefixes are valid
		local prefix
		for prefix in ${prefixes_set}; do
			if ! ip_net_is_valid ${prefix}; then
				error "Unsupported prefix: ${prefix}"
				return ${EXIT_ERROR}
			fi
		done

		assign "${_prefix}" "${prefixes_set}"

	# Perform incremental updates
	else
		local prefix

		# Perform all removals
		for prefix in ${prefixes_removed}; do
			if ! list_remove "${_prefix}" ${prefix}; then
				warning "${prefix} was not on the list and could not be removed"
			fi
		done


		for prefix in ${prefixes_added}; do
			if ip_net_is_valid ${prefix}; then
				if ! list_append_unique "${_prefix}" ${prefix}; then
					warning "${prefix} is already on the prefix list"
				fi
			else
				warning "${prefix} is not a valid IP network and could not be added"
			fi
		done
	fi

	# Check if the list contain at least one valid prefix
	if list_is_empty ${_prefix}; then
		error "Cannot save an empty prefix list"
		return ${EXIT_ERROR}
	fi

	# Save everything
	if ! ipsec_connection_write_config_key "${connection}" "${_prefix}" ${!_prefix}; then
		log ERROR "Could not write configuration settings"
	fi

	return ${EXIT_OK}
}

# Handle the cli after remote
ipsec_connection_remote() {
	if [ ! $# -ge 2 ]; then
		log ERROR "Not enough arguments"
		return ${EXIT_ERROR}
	fi

	local connection=${1}
	local cmd=${2}
	shift 2

	case ${cmd} in
		id)
			ipsec_connection_id "${connection}" "REMOTE" $@
			;;

		prefix)
			ipsec_connection_prefix "${connection}" "REMOTE" $@
			;;
		*)
			log ERROR "Unrecognized argument: ${cmd}"
			return ${EXIT_ERROR}
			;;
	esac

	return ${EXIT_OK}
}

# Set the inactivity timeout
ipsec_connection_inactivity_timeout() {
	if [ ! $# -ge 2 ]; then
		log ERROR "Not enough arguments"
		return ${EXIT_ERROR}
	fi

	local connection=${1}
	shift 1
	local value=$@

	if ! isinteger value; then
		value=$(parse_time $@)
		if [ ! $? -eq 0 ]; then
			log ERROR "Parsing the passed time was not sucessful please check the passed values."
			return ${EXIT_ERROR}
		fi
	fi

	if [ ${value} -le 0 ]; then
		log ERROR "The passed time value must be in the sum greater zero seconds."
		return ${EXIT_ERROR}
	fi

	if ! ipsec_connection_write_config_key "${connection}" "INACTIVITY_TIMEOUT" ${value}; then
		log ERROR "Could not write configuration settings"
		return ${EXIT_ERROR}
	fi

	return ${EXIT_OK}
}

# Set the default start action
ipsec_connection_start_action() {
	if [ ! $# -eq 2 ]; then
		log ERROR "Not enough arguments"
		return ${EXIT_ERROR}
	fi
	local connection=${1}
	local action=${2}

	if ! isoneof action "on-demand" "always-on"; then
		log ERROR "Start action '${action}' is invalid"
		return ${EXIT_ERROR}
	fi

	if ! ipsec_connection_write_config_key "${connection}" "START_ACTION" ${action}; then
		log ERROR "Could not write configuration settings"
		return ${EXIT_ERROR}
	fi
}

# Set the security policy to use
ipsec_connection_security_policy() {
	if [ ! $# -eq 2 ]; then
		log ERROR "Not enough arguments"
		return ${EXIT_ERROR}
	fi
	local connection=${1}
	local security_policy=${2}

	if ! vpn_security_policy_exists ${security_policy}; then
		log ERROR "No such vpn security policy '${security_policy}'"
		return ${EXIT_ERROR}
	fi

	if ! ipsec_connection_write_config_key "${connection}" "SECURITY_POLICY" ${security_policy}; then
		log ERROR "Could not write configuration settings"
		return ${EXIT_ERROR}
	fi
}

# Check if a id is valid
ipsec_connection_check_id() {
	assert [ $# -eq 1 ]
	local id=${1}

	if [[ ${id} =~ ^@[[:alnum:]]+$ ]] || ip_is_valid ${id}; then
		return ${EXIT_TRUE}
	else
		return ${EXIT_FALSE}
	fi
}

# Checks if a peer is valid
ipsec_connection_check_peer() {
	assert [ $# -eq 1 ]
	local peer=${1}

	# TODO Accept also FQDNs
	if ip_is_valid ${peer}; then
		return ${EXIT_TRUE}
	else
		return ${EXIT_FALSE}
	fi
}

# This function checks if a VPN IPsec connection name is valid
# Allowed are only A-Za-z0-9
ipsec_connection_check_name() {
	assert [ $# -eq 1 ]

	local connection=${1}

	[[ "${connection}" =~ [^[:alnum:]$] ]]
}

# Function that creates one VPN IPsec connection
ipsec_connection_new() {
	if [ $# -gt 1 ]; then
		error "Too many arguments"
		return ${EXIT_ERROR}
	fi

	local connection="${1}"
	if ! isset connection; then
		error "Please provide a connection name"
		return ${EXIT_ERROR}
	fi

	# Check for duplicates
	if ipsec_connection_exists "${connection}"; then
		error "The VPN IPsec connection ${connection} already exists"
		return ${EXIT_ERROR}
	fi

	# Check if the name of the connection is valid
	if  ipsec_connection_check_name "${connection}"; then
		error "'${connection}' contains illegal characters"
		return ${EXIT_ERROR}
	fi

	log DEBUG "Creating VPN IPsec connection ${connection}"

	if ! mkdir -p "${NETWORK_IPSEC_CONNS_DIR}/${connection}"; then
		log ERROR "Could not create config directory for ${connection}"
		return ${EXIT_ERROR}
	fi

	local ${IPSEC_CONNECTION_CONFIG_SETTINGS}

	AUTH_MODE=${IPSEC_DEFAULT_AUTH_MODE}
	DPD_ACTION=${IPSEC_DEFAULT_DPD_ACTION}
	DPD_DELAY=${IPSEC_DEFAULT_DPD_DELAY}
	DPD_TIMEOUT=${IPSEC_DEFAULT_DPD_TIMEOUT}
	ENABLED=${IPSEC_DEFAULT_ENABLED}
	MODE=${IPSEC_DEFAULT_MODE}
	START_ACTION=${IPSEC_DEFAULT_START_ACTION}

	INACTIVITY_TIMEOUT=${IPSEC_DEFAULT_INACTIVITY_TIMEOUT}
	SECURITY_POLICY=${IPSEC_DEFAULT_SECURITY_POLICY}

	if ! ipsec_connection_write_config "${connection}"; then
		log ERROR "Could not write new config file"
		return ${EXIT_ERROR}
	fi
}

# Function that deletes based on the passed parameters one ore more vpn security policies
ipsec_connection_destroy() {
	local connection
	for connection in $@; do
		if ! ipsec_connection_exists "${connection}"; then
			log ERROR "The VPN IPsec connection ${connection} does not exist."
			continue
		fi

		log DEBUG "Deleting VPN IPsec connection ${connection}"
		if ! rm -rf "${NETWORK_IPSEC_CONNS_DIR}/${connection}"; then
			log ERROR "Deleting the VPN IPsec connection ${connection} was not sucessful"
			return ${EXIT_ERROR}
		fi
	done
}

# List all ipsec connections
ipsec_list_connections() {
	local connection
	for connection in ${NETWORK_IPSEC_CONNS_DIR}/*; do
		[ -d ${connection} ] || continue
		basename ${connection}
	done
}

ipsec_connection_to_strongswan() {
	local connection="${1}"

	# Read the config settings
	local ${IPSEC_CONNECTION_CONFIG_SETTINGS}
	if ! ipsec_connection_read_config "${connection}"; then
		error "Could not read the connection ${connection}"
		return ${EXIT_ERROR}
	fi

	local path="${NETWORK_IPSEC_SWANCTL_CONNECTIONS_DIR}/${connection}.conf"

	(
		# Write the connection section
		_ipsec_connection_to_strongswan_connection "${connection}"

		# Write the secrets section
		_ipsec_connection_to_strongswan_secrets "${connection}"

	) > ${path}
}

_ipsec_connection_to_strongswan_connection() {
	local connection="${1}"

	# Read the security policy
	local ${VPN_SECURITY_POLICIES_CONFIG_SETTINGS}
	if ! vpn_security_policies_read_config "${SECURITY_POLICY}"; then
		return ${EXIT_ERROR}
	fi

	# Is DPD enabled?
	local dpd="false"
	if isset DPD_DELAY && isinteger DPD_DELAY && [ ${DPD_DELAY} -gt 0 ]; then
		dpd="true"
	fi

	print_indent 0 "connections {"
	print_indent 1 "${connection} {"

	# IKE Version
	print_indent 2 "# IKE Version"
	case "${KEY_EXCHANGE^^}" in
		IKEV1)
			print_indent 2 "version = 1"
			;;

		# Fall back to IKEv2 for any random values
		IKEV2|*)
			print_indent 2 "version = 2"
			;;
	esac
	print # empty line

	# Always only keep one connection open at a time
	print_indent 2 "# Unique IDs"
	print_indent 2 "unique = replace"
	print

	# Local Address
	print_indent 2 "# Local Address"
	if isset LOCAL_ADDRESS; then
		print_indent 2 "local_addrs = ${LOCAL_ADDRESS}"
	else
		print_indent 2 "local_addrs = %any"
	fi
	print

	# Remote Address
	print_indent 2 "# Remote Address"
	if isset PEER; then
		print_indent 2 "remote_addrs = ${PEER}"
	else
		print_indent 2 "remote_addrs = %any"
	fi
	print

	# IKE Proposals
	print_indent 2 "# IKE Proposals"
	print_indent 2 "proposals = $(vpn_security_policies_make_ike_proposal ${SECURITY_POLICY})"
	print

	# DPD Settings
	if enabled dpd; then
		print_indent 2 "# Dead Peer Detection"
		print_indent 2 "dpd_delay = ${DPD_DELAY}"

		if isset DPD_TIMEOUT; then
			print_indent 2 "dpd_timeout = ${DPD_TIMEOUT}"
		fi

		print
	fi

	# Fragmentation
	print_indent 2 "# Fragmentation"
	print_indent 2 "fragmentation = yes"
	print

	# Local
	print_indent 2 "local {"

	# Local ID
	if isset LOCAL_ID; then
		print_indent 3 "id = ${LOCAL_ID}"
	fi

	# Authentication
	case "${AUTH_MODE}" in
		PSK)
			print_indent 3 "auth = psk"
			;;
	esac

	print_indent 2 "}"
	print

	# Remote
	print_indent 2 "remote {"

	# Remote ID
	if isset REMOTE_ID; then
		print_indent 3 "id = ${REMOTE_ID}"
	fi

	# Authentication
	case "${AUTH_MODE}" in
		PSK)
			print_indent 3 "auth = psk"
			;;
	esac

	print_indent 2 "}"
	print

	# Children

	print_indent 2 "children {"
	print_indent 3 "${connection} {"

	print_indent 4 "# ESP Proposals"
	print_indent 4 "esp_proposals = $(vpn_security_policies_make_esp_proposal ${SECURITY_POLICY})"
	print

	# Traffic Selectors

	case "${MODE}" in
		gre-*)
			print_indent 4 "local_ts = dynamic[gre]"
			print_indent 4 "remote_ts = dynamic[gre]"
			;;
		*)
			# Local Prefixes
			if isset LOCAL_PREFIX; then
				print_indent 4 "local_ts = $(list_join LOCAL_PREFIX ,)"
			else
				print_indent 4 "local_ts = dynamic"
			fi

			# Remote Prefixes
			if isset REMOTE_PREFIX; then
				print_indent 4 "remote_ts = $(list_join REMOTE_PREFIX ,)"
			else
				print_indent 4 "remote_ts = dynamic"
			fi
			;;
	esac
	print

	# Netfilter Marks
	print_indent 4 "# Netfilter Marks"
	print_indent 4 "mark_in = %unique"
	print_indent 4 "mark_out = %unique"
	print

	# Dead Peer Detection
	if enabled dpd; then
		print_indent 4 "# Dead Peer Detection"
		print_indent 4 "dpd_action = ${DPD_ACTION}"
		print
	fi

	# Rekeying
	if isset LIFETIME; then
		print_indent 4 "# Rekey Time"
		print_indent 4 "rekey_time = ${LIFETIME}"
		print
	fi

	# Updown Script
	print_indent 4 "updown = ${NETWORK_HELPERS_DIR}/ipsec-updown"
	print

	# Mode
	print_indent 4 "# Mode"
	case "${MODE}" in
		gre-transport)
			print_indent 4 "mode = transport"
			;;
		tunnel|vti|*)
			print_indent 4 "mode = tunnel"
			;;
	esac
	print

	# Compression
	print_indent 4 "# Compression"
	if enabled COMPRESSION; then
		print_indent 4 "ipcomp = yes"
	else
		print_indent 4 "ipcomp = no"
	fi
	print

	# Inactivity Timeout
	if isset INACTIVITY_TIMEOUT; then
		print_indent 4 "# Inactivity Timeout"
		print_indent 4 "inactivity = ${INACTIVITY_TIMEOUT}"
		print
	fi

	# Start Action
	print_indent 4 "# Start Action"
	case "${START_ACTION}" in
		on-demand)
			print_indent 4 "start_action = trap"
			print_indent 4 "close_action = trap"
			;;
		wait)
			print_indent 4 "start_action = none"
			print_indent 4 "close_action = none"
			;;
		always-on|*)
			print_indent 4 "start_action = start"
			print_indent 4 "close_action = start"
			;;
	esac
	print

	print_indent 3 "}"
	print_indent 2 "}"
	print

	print_indent 1 "}"
	print_indent 0 "}"
	print
}

_ipsec_connection_to_strongswan_secrets() {
	local connection="${1}"

	print_indent 0 "secrets {"

	case "${AUTH_MODE}" in
		PSK)
			print_indent 1 "ike {"

			# Secret
			print_indent 2 "secret = ${PSK}"

			# ID
			if isset REMOTE_ID; then
				print_indent 2 "id = ${REMOTE_ID}"
			fi

			print_indent 1 "}"
			;;
	esac

	print_indent 0 "}"
}