diff options
Diffstat (limited to 'src/conf_mode/zone_policy.py')
| -rwxr-xr-x | src/conf_mode/zone_policy.py | 213 |
1 files changed, 213 insertions, 0 deletions
diff --git a/src/conf_mode/zone_policy.py b/src/conf_mode/zone_policy.py new file mode 100755 index 000000000..070a4deea --- /dev/null +++ b/src/conf_mode/zone_policy.py @@ -0,0 +1,213 @@ +#!/usr/bin/env python3 +# +# Copyright (C) 2021-2022 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 json import loads +from sys import exit + +from vyos.config import Config +from vyos.configdict import dict_merge +from vyos.template import render +from vyos.util import cmd +from vyos.util import dict_search_args +from vyos.util import run +from vyos.xml import defaults +from vyos import ConfigError +from vyos import airbag +airbag.enable() + +nftables_conf = '/run/nftables_zone.conf' + +def get_config(config=None): + if config: + conf = config + else: + conf = Config() + base = ['zone-policy'] + zone_policy = conf.get_config_dict(base, key_mangling=('-', '_'), + get_first_key=True, + no_tag_node_value_mangle=True) + + zone_policy['firewall'] = conf.get_config_dict(['firewall'], + key_mangling=('-', '_'), + get_first_key=True, + no_tag_node_value_mangle=True) + + if 'zone' in zone_policy: + # 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 + ['zone']) + for zone in zone_policy['zone']: + zone_policy['zone'][zone] = dict_merge(default_values, + zone_policy['zone'][zone]) + + return zone_policy + +def verify(zone_policy): + # bail out early - looks like removal from running config + if not zone_policy: + return None + + local_zone = False + interfaces = [] + + if 'zone' in zone_policy: + for zone, zone_conf in zone_policy['zone'].items(): + if 'local_zone' not in zone_conf and 'interface' not in zone_conf: + raise ConfigError(f'Zone "{zone}" has no interfaces and is not the local zone') + + if 'local_zone' in zone_conf: + if local_zone: + raise ConfigError('There cannot be multiple local zones') + if 'interface' in zone_conf: + raise ConfigError('Local zone cannot have interfaces assigned') + if 'intra_zone_filtering' in zone_conf: + raise ConfigError('Local zone cannot use intra-zone-filtering') + local_zone = True + + if 'interface' in zone_conf: + found_duplicates = [intf for intf in zone_conf['interface'] if intf in interfaces] + + if found_duplicates: + raise ConfigError(f'Interfaces cannot be assigned to multiple zones') + + interfaces += zone_conf['interface'] + + if 'intra_zone_filtering' in zone_conf: + intra_zone = zone_conf['intra_zone_filtering'] + + if len(intra_zone) > 1: + raise ConfigError('Only one intra-zone-filtering action must be specified') + + if 'firewall' in intra_zone: + v4_name = dict_search_args(intra_zone, 'firewall', 'name') + if v4_name and not dict_search_args(zone_policy, 'firewall', 'name', v4_name): + raise ConfigError(f'Firewall name "{v4_name}" does not exist') + + v6_name = dict_search_args(intra_zone, 'firewall', 'ipv6-name') + if v6_name and not dict_search_args(zone_policy, 'firewall', 'ipv6-name', v6_name): + raise ConfigError(f'Firewall ipv6-name "{v6_name}" does not exist') + + if not v4_name and not v6_name: + raise ConfigError('No firewall names specified for intra-zone-filtering') + + if 'from' in zone_conf: + for from_zone, from_conf in zone_conf['from'].items(): + if from_zone not in zone_policy['zone']: + raise ConfigError(f'Zone "{zone}" refers to a non-existent or deleted zone "{from_zone}"') + + v4_name = dict_search_args(from_conf, 'firewall', 'name') + if v4_name: + if 'name' not in zone_policy['firewall']: + raise ConfigError(f'Firewall name "{v4_name}" does not exist') + + if not dict_search_args(zone_policy, 'firewall', 'name', v4_name): + raise ConfigError(f'Firewall name "{v4_name}" does not exist') + + v6_name = dict_search_args(from_conf, 'firewall', 'v6_name') + if v6_name: + if 'ipv6_name' not in zone_policy['firewall']: + raise ConfigError(f'Firewall ipv6-name "{v6_name}" does not exist') + + if not dict_search_args(zone_policy, 'firewall', 'ipv6_name', v6_name): + raise ConfigError(f'Firewall ipv6-name "{v6_name}" does not exist') + + return None + +def has_ipv4_fw(zone_conf): + if 'from' not in zone_conf: + return False + zone_from = zone_conf['from'] + return any([True for fz in zone_from if dict_search_args(zone_from, fz, 'firewall', 'name')]) + +def has_ipv6_fw(zone_conf): + if 'from' not in zone_conf: + return False + zone_from = zone_conf['from'] + return any([True for fz in zone_from if dict_search_args(zone_from, fz, 'firewall', 'ipv6_name')]) + +def get_local_from(zone_policy, local_zone_name): + # Get all zone firewall names from the local zone + out = {} + for zone, zone_conf in zone_policy['zone'].items(): + if zone == local_zone_name: + continue + if 'from' not in zone_conf: + continue + if local_zone_name in zone_conf['from']: + out[zone] = zone_conf['from'][local_zone_name] + return out + +def cleanup_commands(): + commands = [] + for table in ['ip filter', 'ip6 filter']: + json_str = cmd(f'nft -j list table {table}') + obj = loads(json_str) + if 'nftables' not in obj: + continue + for item in obj['nftables']: + if 'rule' in item: + chain = item['rule']['chain'] + handle = item['rule']['handle'] + if 'expr' not in item['rule']: + continue + for expr in item['rule']['expr']: + target = dict_search_args(expr, 'jump', 'target') + if not target: + continue + if target.startswith("VZONE") or target.startswith("VYOS_STATE_POLICY"): + commands.append(f'delete rule {table} {chain} handle {handle}') + for item in obj['nftables']: + if 'chain' in item: + if item['chain']['name'].startswith("VZONE"): + chain = item['chain']['name'] + commands.append(f'delete chain {table} {chain}') + return commands + +def generate(zone_policy): + data = zone_policy or {} + + if os.path.exists(nftables_conf): # Check to see if we've run before + data['cleanup_commands'] = cleanup_commands() + + if 'zone' in data: + for zone, zone_conf in data['zone'].items(): + zone_conf['ipv4'] = has_ipv4_fw(zone_conf) + zone_conf['ipv6'] = has_ipv6_fw(zone_conf) + + if 'local_zone' in zone_conf: + zone_conf['from_local'] = get_local_from(data, zone) + + render(nftables_conf, 'zone_policy/nftables.j2', data) + return None + +def apply(zone_policy): + install_result = run(f'nft -f {nftables_conf}') + if install_result != 0: + raise ConfigError('Failed to apply zone-policy') + + return None + +if __name__ == '__main__': + try: + c = get_config() + verify(c) + generate(c) + apply(c) + except ConfigError as e: + print(e) + exit(1) |