#!/usr/bin/env python3 # # Copyright (C) 2018-2020 VyOS maintainers and contributors # # This program is free software; you can redistribute it and/or modify # it under the terms of the GNU General Public License version 2 or later as # published by the Free Software Foundation. # # 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/>. import os from sys import exit from vyos.config import Config from vyos.configdict import dict_merge from vyos.template import render from vyos.util import call from vyos.util import dict_search from vyos.xml import defaults from vyos import ConfigError from vyos import airbag airbag.enable() config_file = r'/run/dhcp-relay/dhcrelay.conf' def get_config(config=None): if config: conf = config else: conf = Config() base = ['service', 'dhcp-relay'] if not conf.exists(base): return None relay = conf.get_config_dict(base, key_mangling=('-', '_'), get_first_key=True) # We have gathered the dict representation of the CLI, but there are default # options which we need to update into the dictionary retrived. default_values = defaults(base) relay = dict_merge(default_values, relay) return relay def verify(relay): # bail out early - looks like removal from running config if not relay: return None if 'lo' in (dict_search('interface', relay) or []): raise ConfigError('DHCP relay does not support the loopback interface.') if 'server' not in relay : raise ConfigError('No DHCP relay server(s) configured.\n' \ 'At least one DHCP relay server required.') return None def generate(relay): # bail out early - looks like removal from running config if not relay: return None render(config_file, 'dhcp-relay/dhcrelay.conf.j2', relay) return None def apply(relay): # bail out early - looks like removal from running config service_name = 'isc-dhcp-relay.service' if not relay: call(f'systemctl stop {service_name}') if os.path.exists(config_file): os.unlink(config_file) return None call(f'systemctl restart {service_name}') return None if __name__ == '__main__': try: c = get_config() verify(c) generate(c) apply(c) except ConfigError as e: print(e) exit(1)