configure() {
	# check if gateway config exists
	if ! uci -q show gateway > /dev/null; then
		echo "ERROR: Gateway config could not be parsed or does not exist."

		return 1
	fi

	# check version of configuration
	local expected_version=1
	local config_version=$(uci -q get gateway.meta.config_version)

	if ! [ -n "$config_version" ]; then
		echo "ERROR: No config version given. Supported versions: '$expected_version'"

		return 1
	fi

	if [ "$config_version" != "$expected_version" ]; then
		echo "ERROR: Invalid config version. Expected '$expected_version', got '$config_version'."
		echo "Please check what has been changed and adjust your config appropriately."

		return 1
	fi

	return 0
}