#!/usr/bin/env python3 # # Copyright (C) 2019-2022 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 netifaces import interfaces from vyos.base import Warning from vyos.config import Config from vyos.configdict import get_interface_dict from vyos.configdict import leaf_node_changed from vyos.configverify import verify_address from vyos.configverify import verify_bridge_delete from vyos.configverify import verify_mtu_ipv6 from vyos.configverify import verify_mirror_redirect from vyos.configverify import verify_source_interface from vyos.ifconfig import Interface from vyos.ifconfig import VXLANIf from vyos.template import is_ipv6 from vyos import ConfigError from vyos import airbag airbag.enable() def get_config(config=None): """ Retrive CLI config as dictionary. Dictionary can never be empty, as at least the interface name will be added or a deleted flag """ if config: conf = config else: conf = Config() base = ['interfaces', 'vxlan'] vxlan = get_interface_dict(conf, base) # VXLAN interfaces are picky and require recreation if certain parameters # change. But a VXLAN interface should - of course - not be re-created if # it's description or IP address is adjusted. Feels somehow logic doesn't it? for cli_option in ['external', 'gpe', 'group', 'port', 'remote', 'source-address', 'source-interface', 'vni', 'parameters ip dont-fragment', 'parameters ip tos', 'parameters ip ttl']: if leaf_node_changed(conf, cli_option.split()): vxlan.update({'rebuild_required': {}}) # We need to verify that no other VXLAN tunnel is configured when external # mode is in use - Linux Kernel limitation conf.set_level(base) vxlan['other_tunnels'] = conf.get_config_dict([], key_mangling=('-', '_'), get_first_key=True, no_tag_node_value_mangle=True) # This if-clause is just to be sure - it will always evaluate to true ifname = vxlan['ifname'] if ifname in vxlan['other_tunnels']: del vxlan['other_tunnels'][ifname] if len(vxlan['other_tunnels']) == 0: del vxlan['other_tunnels'] return vxlan def verify(vxlan): if 'deleted' in vxlan: verify_bridge_delete(vxlan) return None if int(vxlan['mtu']) < 1500: Warning('RFC7348 recommends VXLAN tunnels preserve a 1500 byte MTU') if 'group' in vxlan: if 'source_interface' not in vxlan: raise ConfigError('Multicast VXLAN requires an underlaying interface') verify_source_interface(vxlan) if not any(tmp in ['group', 'remote', 'source_address'] for tmp in vxlan): raise ConfigError('Group, remote or source-address must be configured') if 'vni' not in vxlan and 'external' not in vxlan: raise ConfigError( 'Must either configure VXLAN "vni" or use "external" CLI option!') if {'external', 'vni'} <= set(vxlan): raise ConfigError('Can not specify both "external" and "VNI"!') if {'external', 'other_tunnels'} <= set(vxlan): other_tunnels = ', '.join(vxlan['other_tunnels']) raise ConfigError(f'Only one VXLAN tunnel is supported when "external" '\ f'CLI option is used. Additional tunnels: {other_tunnels}') if 'gpe' in vxlan and 'external' not in vxlan: raise ConfigError(f'VXLAN-GPE is only supported when "external" '\ f'CLI option is used.') if 'source_interface' in vxlan: # VXLAN adds at least an overhead of 50 byte - we need to check the # underlaying device if our VXLAN package is not going to be fragmented! vxlan_overhead = 50 if 'source_address' in vxlan and is_ipv6(vxlan['source_address']): # IPv6 adds an extra 20 bytes overhead because the IPv6 header is 20 # bytes larger than the IPv4 header - assuming no extra options are # in use. vxlan_overhead += 20 lower_mtu = Interface(vxlan['source_interface']).get_mtu() if lower_mtu < (int(vxlan['mtu']) + vxlan_overhead): raise ConfigError(f'Underlaying device MTU is to small ({lower_mtu} '\ f'bytes) for VXLAN overhead ({vxlan_overhead} bytes!)') # Check for mixed IPv4 and IPv6 addresses protocol = None if 'source_address' in vxlan: if is_ipv6(vxlan['source_address']): protocol = 'ipv6' else: protocol = 'ipv4' if 'remote' in vxlan: error_msg = 'Can not mix both IPv4 and IPv6 for VXLAN underlay' for remote in vxlan['remote']: if is_ipv6(remote): if protocol == 'ipv4': raise ConfigError(error_msg) protocol = 'ipv6' else: if protocol == 'ipv6': raise ConfigError(error_msg) protocol = 'ipv4' verify_mtu_ipv6(vxlan) verify_address(vxlan) verify_mirror_redirect(vxlan) return None def generate(vxlan): return None def apply(vxlan): # Check if the VXLAN interface already exists if 'rebuild_required' in vxlan or 'delete' in vxlan: if vxlan['ifname'] in interfaces(): v = VXLANIf(vxlan['ifname']) # VXLAN is super picky and the tunnel always needs to be recreated, # thus we can simply always delete it first. v.remove() if 'deleted' not in vxlan: # Finally create the new interface v = VXLANIf(**vxlan) v.update(vxlan) return None if __name__ == '__main__': try: c = get_config() verify(c) generate(c) apply(c) except ConfigError as e: print(e) exit(1)