diff options
Diffstat (limited to 'src/conf_mode/protocols_bfd.py')
| -rwxr-xr-x | src/conf_mode/protocols_bfd.py | 166 |
1 files changed, 166 insertions, 0 deletions
diff --git a/src/conf_mode/protocols_bfd.py b/src/conf_mode/protocols_bfd.py new file mode 100755 index 000000000..04549f4b4 --- /dev/null +++ b/src/conf_mode/protocols_bfd.py @@ -0,0 +1,166 @@ +#!/usr/bin/env python3 +# +# Copyright (C) 2019 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 sys +import jinja2 +import copy +import os +import vyos.validate + +from vyos import ConfigError +from vyos.config import Config + +config_file = r'/tmp/bfd.frr' + +# Please be careful if you edit the template. +config_tmpl = """ +! +bfd +{% for peer in old_peers -%} + no peer {{ peer }} +{% endfor -%} +! +{% for peer in new_peers -%} + peer {{ peer.remote }}{% if peer.multihop %} multihop{% endif %}{% if peer.src_addr %} local-address {{ peer.src_addr }}{% endif %}{% if peer.src_if %} interface {{ peer.src_if }}{% endif %} + detect-multiplier {{ peer.multiplier }} + receive-interval {{ peer.rx_interval }} + transmit-interval {{ peer.tx_interval }} + {% if not peer.shutdown %}no {% endif %}shutdown +{% endfor -%} +! +""" + +default_config_data = { + 'new_peers': [], + 'old_peers' : [] +} + +def get_config(): + bfd = copy.deepcopy(default_config_data) + conf = Config() + if not (conf.exists('protocols bfd') or conf.exists_effective('protocols bfd')): + return None + else: + conf.set_level('protocols bfd') + + # as we have to use vtysh to talk to FRR we also need to know + # which peers are gone due to a config removal - thus we read in + # all peers (active or to delete) + bfd['old_peers'] = conf.list_effective_nodes('peer') + + for peer in conf.list_nodes('peer'): + conf.set_level('protocols bfd peer {0}'.format(peer)) + bfd_peer = { + 'remote': peer, + 'shutdown': False, + 'src_if': '', + 'src_addr': '', + 'multiplier': '3', + 'rx_interval': '300', + 'tx_interval': '300', + 'multihop': False + } + + # Check if individual peer is disabled + if conf.exists('shutdown'): + bfd_peer['shutdown'] = True + + # Check if peer has a local source interface configured + if conf.exists('source interface'): + bfd_peer['src_if'] = conf.return_value('source interface') + + # Check if peer has a local source address configured - this is mandatory for IPv6 + if conf.exists('source address'): + bfd_peer['src_addr'] = conf.return_value('source address') + + # Tell BFD daemon that we should expect packets with TTL less than 254 + # (because it will take more than one hop) and to listen on the multihop + # port (4784) + if conf.exists('multihop'): + bfd_peer['multihop'] = True + + # Configures the minimum interval that this system is capable of receiving + # control packets. The default value is 300 milliseconds. + if conf.exists('interval receive'): + bfd_peer['rx_interval'] = conf.return_value('interval receive') + + # The minimum transmission interval (less jitter) that this system wants + # to use to send BFD control packets. + if conf.exists('interval transmit'): + bfd_peer['tx_interval'] = conf.return_value('interval transmit') + + # Configures the detection multiplier to determine packet loss. The remote + # transmission interval will be multiplied by this value to determine the + # connection loss detection timer. The default value is 3. + if conf.exists('interval multiplier'): + bfd_peer['multiplier'] = conf.return_value('interval multiplier') + + bfd['new_peers'].append(bfd_peer) + + return bfd + +def verify(bfd): + if bfd is None: + return None + + for peer in bfd['new_peers']: + # Bail out early if peer is shutdown + if peer['shutdown']: + continue + + # IPv6 peers require an explicit local address/interface combination + if vyos.validate.is_ipv6(peer['remote']): + if not (peer['src_if'] and peer['src_addr']): + raise ConfigError('BFD IPv6 peers require explicit local address/interface setting') + + # multihop doesn't accept interface names + if peer['multihop'] and peer['src_if']: + raise ConfigError('multihop does not accept interface names') + + + return None + +def generate(bfd): + if bfd is None: + return None + + return None + +def apply(bfd): + if bfd is None: + return None + + tmpl = jinja2.Template(config_tmpl) + config_text = tmpl.render(bfd) + with open(config_file, 'w') as f: + f.write(config_text) + + os.system("sudo vtysh -d bfdd -f " + config_file) + if os.path.exists(config_file): + os.remove(config_file) + + return None + +if __name__ == '__main__': + try: + c = get_config() + verify(c) + generate(c) + apply(c) + except ConfigError as e: + print(e) + sys.exit(1) |