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#!/usr/bin/env python3
#
# Copyright (C) 2021 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/>.
from sys import exit
from vyos.config import Config
from vyos.configdict import dict_merge
from vyos.template import render_to_string
from vyos.util import dict_search
from vyos import ConfigError
from vyos import frr
from vyos import airbag
airbag.enable()
def get_config(config=None):
if config:
conf = config
else:
conf = Config()
base = ['policy']
policy = conf.get_config_dict(base, key_mangling=('-', '_'), get_first_key=True,
no_tag_node_value_mangle=True)
return policy
def verify(policy):
if not policy:
return None
for policy_type in ['access_list', 'access_list6', 'as_path_list',
'community_list', 'extcommunity_list', 'large_community_list',
'prefix_list', 'prefix_list6', 'route_map']:
# Bail out early and continue with next policy type
if policy_type not in policy:
continue
# instance can be an ACL name/number, prefix-list name or route-map name
for instance, instance_config in policy[policy_type].items():
# If no rule was found within the instance ... sad, but we can leave
# early as nothing needs to be verified
if 'rule' not in instance_config:
continue
# human readable instance name (hypen instead of underscore)
policy_hr = policy_type.replace('_', '-')
for rule, rule_config in instance_config['rule'].items():
mandatory_error = f'must be specified for "{policy_hr} {instance} rule {rule}"!'
if 'action' not in rule_config:
raise ConfigError(f'Action {mandatory_error}')
if policy_type == 'access_list':
if 'source' not in rule_config:
raise ConfigError(f'Source {mandatory_error}')
if int(instance) in range(100, 200) or int(instance) in range(2000, 2700):
if 'destination' not in rule_config:
raise ConfigError(f'Destination {mandatory_error}')
if policy_type == 'access_list6':
if 'source' not in rule_config:
raise ConfigError(f'Source {mandatory_error}')
if policy_type in ['as_path_list', 'community_list', 'extcommunity_list',
'large_community_list']:
if 'regex' not in rule_config:
raise ConfigError(f'Regex {mandatory_error}')
# route-maps tend to be a bit more complex so they get their own verify() section
if 'route_map' in policy:
for route_map, route_map_config in policy['route_map'].items():
if 'rule' not in route_map_config:
continue
for rule, rule_config in route_map_config['rule'].items():
# Specified community-list must exist
tmp = dict_search('match.community.community_list', rule_config)
if tmp and tmp not in policy.get('community_list', []):
raise ConfigError(f'community-list {tmp} does not exist!')
# Specified extended community-list must exist
tmp = dict_search('match.extcommunity', rule_config)
if tmp and tmp not in policy.get('extcommunity_list', []):
raise ConfigError(f'extcommunity-list {tmp} does not exist!')
# Specified large-community-list must exist
tmp = dict_search('match.large_community.large_community_list', rule_config)
if tmp and tmp not in policy.get('large_community_list', []):
raise ConfigError(f'large-community-list {tmp} does not exist!')
return None
def generate(policy):
if not policy:
policy['new_frr_config'] = ''
return None
policy['new_frr_config'] = render_to_string('frr/policy.frr.tmpl', policy)
return None
def apply(policy):
bgp_daemon = 'bgpd'
zebra_daemon = 'zebra'
# Save original configuration prior to starting any commit actions
frr_cfg = frr.FRRConfig()
# The route-map used for the FIB (zebra) is part of the zebra daemon
frr_cfg.load_configuration(bgp_daemon)
frr_cfg.modify_section(r'^bgp as-path access-list .*')
frr_cfg.modify_section(r'^bgp community-list .*')
frr_cfg.modify_section(r'^bgp extcommunity-list .*')
frr_cfg.modify_section(r'^bgp large-community-list .*')
frr_cfg.add_before('^line vty', policy['new_frr_config'])
frr_cfg.commit_configuration(bgp_daemon)
# The route-map used for the FIB (zebra) is part of the zebra daemon
frr_cfg.load_configuration(zebra_daemon)
frr_cfg.modify_section(r'^access-list .*')
frr_cfg.modify_section(r'^ipv6 access-list .*')
frr_cfg.modify_section(r'^ip prefix-list .*')
frr_cfg.modify_section(r'^ipv6 prefix-list .*')
frr_cfg.modify_section(r'^route-map .*')
frr_cfg.add_before('^line vty', policy['new_frr_config'])
frr_cfg.commit_configuration(zebra_daemon)
# If FRR config is blank, rerun the blank commit x times due to frr-reload
# behavior/bug not properly clearing out on one commit.
if policy['new_frr_config'] == '':
for a in range(5):
frr_cfg.commit_configuration(zebra_daemon)
# Save configuration to /run/frr/config/frr.conf
frr.save_configuration()
return None
if __name__ == '__main__':
try:
c = get_config()
verify(c)
generate(c)
apply(c)
except ConfigError as e:
print(e)
exit(1)
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