#!/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 . import os import re from glob import glob from json import loads from sys import exit from vyos.base import Warning from vyos.config import Config from vyos.configdict import dict_merge from vyos.configdict import node_changed from vyos.configdiff import get_config_diff, Diff # from vyos.configverify import verify_interface_exists from vyos.firewall import geoip_update from vyos.firewall import get_ips_domains_dict from vyos.firewall import nft_add_set_elements from vyos.firewall import nft_flush_set from vyos.firewall import nft_init_set from vyos.firewall import nft_update_set_elements from vyos.template import render from vyos.util import call from vyos.util import cmd from vyos.util import dict_search_args from vyos.util import dict_search_recursive from vyos.util import process_named_running from vyos.util import rc_cmd from vyos.xml import defaults from vyos import ConfigError from vyos import airbag airbag.enable() policy_route_conf_script = '/usr/libexec/vyos/conf_mode/policy-route.py' nftables_conf = '/run/nftables.conf' nftables_zone_conf = '/run/nftables_zone.conf' nftables6_zone_conf = '/run/nftables_zone6.conf' sysfs_config = { 'all_ping': {'sysfs': '/proc/sys/net/ipv4/icmp_echo_ignore_all', 'enable': '0', 'disable': '1'}, 'broadcast_ping': {'sysfs': '/proc/sys/net/ipv4/icmp_echo_ignore_broadcasts', 'enable': '0', 'disable': '1'}, 'ip_src_route': {'sysfs': '/proc/sys/net/ipv4/conf/*/accept_source_route'}, 'ipv6_receive_redirects': {'sysfs': '/proc/sys/net/ipv6/conf/*/accept_redirects'}, 'ipv6_src_route': {'sysfs': '/proc/sys/net/ipv6/conf/*/accept_source_route', 'enable': '0', 'disable': '-1'}, 'log_martians': {'sysfs': '/proc/sys/net/ipv4/conf/all/log_martians'}, 'receive_redirects': {'sysfs': '/proc/sys/net/ipv4/conf/*/accept_redirects'}, 'send_redirects': {'sysfs': '/proc/sys/net/ipv4/conf/*/send_redirects'}, 'source_validation': {'sysfs': '/proc/sys/net/ipv4/conf/*/rp_filter', 'disable': '0', 'strict': '1', 'loose': '2'}, 'syn_cookies': {'sysfs': '/proc/sys/net/ipv4/tcp_syncookies'}, 'twa_hazards_protection': {'sysfs': '/proc/sys/net/ipv4/tcp_rfc1337'} } valid_groups = [ 'address_group', 'domain_group', 'network_group', 'port_group' ] nested_group_types = [ 'address_group', 'network_group', 'mac_group', 'port_group', 'ipv6_address_group', 'ipv6_network_group' ] snmp_change_type = { 'unknown': 0, 'add': 1, 'delete': 2, 'change': 3 } snmp_event_source = 1 snmp_trap_mib = 'VYATTA-TRAP-MIB' snmp_trap_name = 'mgmtEventTrap' def get_firewall_zones(conf): used_v4 = [] used_v6 = [] zone_policy = conf.get_config_dict(['zone-policy'], key_mangling=('-', '_'), get_first_key=True, no_tag_node_value_mangle=True) if 'zone' in zone_policy: for zone, zone_conf in zone_policy['zone'].items(): if 'from' in zone_conf: for from_zone, from_conf in zone_conf['from'].items(): name = dict_search_args(from_conf, 'firewall', 'name') if name: used_v4.append(name) ipv6_name = dict_search_args(from_conf, 'firewall', 'ipv6_name') if ipv6_name: used_v6.append(ipv6_name) if 'intra_zone_filtering' in zone_conf: name = dict_search_args(zone_conf, 'intra_zone_filtering', 'firewall', 'name') if name: used_v4.append(name) ipv6_name = dict_search_args(zone_conf, 'intra_zone_filtering', 'firewall', 'ipv6_name') if ipv6_name: used_v6.append(ipv6_name) else: return None return {'name': used_v4, 'ipv6_name': used_v6} def geoip_updated(conf, firewall): diff = get_config_diff(conf) node_diff = diff.get_child_nodes_diff(['firewall'], expand_nodes=Diff.DELETE, recursive=True) out = { 'name': [], 'ipv6_name': [], 'deleted_name': [], 'deleted_ipv6_name': [] } updated = False for key, path in dict_search_recursive(firewall, 'geoip'): set_name = f'GEOIP_CC_{path[1]}_{path[3]}' if path[0] == 'name': out['name'].append(set_name) elif path[0] == 'ipv6_name': out['ipv6_name'].append(set_name) updated = True if 'delete' in node_diff: for key, path in dict_search_recursive(node_diff['delete'], 'geoip'): set_name = f'GEOIP_CC_{path[1]}_{path[3]}' if path[0] == 'name': out['deleted_name'].append(set_name) elif path[0] == 'ipv6-name': out['deleted_ipv6_name'].append(set_name) updated = True if updated: return out return False def get_config(config=None): if config: conf = config else: conf = Config() base = ['firewall'] firewall = conf.get_config_dict(base, key_mangling=('-', '_'), get_first_key=True, no_tag_node_value_mangle=True) # We have gathered the dict representation of the CLI, but there are # default options which we need to update into the dictionary retrived. # XXX: T2665: we currently have no nice way for defaults under tag # nodes, thus we load the defaults "by hand" default_values = defaults(base) for tmp in ['name', 'ipv6_name']: if tmp in default_values: del default_values[tmp] firewall = dict_merge(default_values, firewall) # Merge in defaults for IPv4 ruleset if 'name' in firewall: default_values = defaults(base + ['name']) for name in firewall['name']: firewall['name'][name] = dict_merge(default_values, firewall['name'][name]) # Merge in defaults for IPv6 ruleset if 'ipv6_name' in firewall: default_values = defaults(base + ['ipv6-name']) for ipv6_name in firewall['ipv6_name']: firewall['ipv6_name'][ipv6_name] = dict_merge(default_values, firewall['ipv6_name'][ipv6_name]) firewall['policy_resync'] = bool('group' in firewall or node_changed(conf, base + ['group'])) firewall['zone_policy'] = get_firewall_zones(conf) if 'config_trap' in firewall and firewall['config_trap'] == 'enable': diff = get_config_diff(conf) firewall['trap_diff'] = diff.get_child_nodes_diff_str(base) firewall['trap_targets'] = conf.get_config_dict(['service', 'snmp', 'trap-target'], key_mangling=('-', '_'), get_first_key=True, no_tag_node_value_mangle=True) firewall['geoip_updated'] = geoip_updated(conf, firewall) return firewall def verify_rule(firewall, rule_conf, ipv6): if 'action' not in rule_conf: raise ConfigError('Rule action must be defined') if 'fragment' in rule_conf: if {'match_frag', 'match_non_frag'} <= set(rule_conf['fragment']): raise ConfigError('Cannot specify both "match-frag" and "match-non-frag"') if 'limit' in rule_conf: if 'rate' in rule_conf['limit']: rate_int = re.sub(r'\D', '', rule_conf['limit']['rate']) if int(rate_int) < 1: raise ConfigError('Limit rate integer cannot be less than 1') if 'ipsec' in rule_conf: if {'match_ipsec', 'match_non_ipsec'} <= set(rule_conf['ipsec']): raise ConfigError('Cannot specify both "match-ipsec" and "match-non-ipsec"') if 'recent' in rule_conf: if not {'count', 'time'} <= set(rule_conf['recent']): raise ConfigError('Recent "count" and "time" values must be defined') tcp_flags = dict_search_args(rule_conf, 'tcp', 'flags') if tcp_flags: if dict_search_args(rule_conf, 'protocol') != 'tcp': raise ConfigError('Protocol must be tcp when specifying tcp flags') not_flags = dict_search_args(rule_conf, 'tcp', 'flags', 'not') if not_flags: duplicates = [flag for flag in tcp_flags if flag in not_flags] if duplicates: raise ConfigError(f'Cannot match a tcp flag as set and not set') if 'protocol' in rule_conf: if rule_conf['protocol'] == 'icmp' and ipv6: raise ConfigError(f'Cannot match IPv4 ICMP protocol on IPv6, use ipv6-icmp') if rule_conf['protocol'] == 'ipv6-icmp' and not ipv6: raise ConfigError(f'Cannot match IPv6 ICMP protocol on IPv4, use icmp') for side in ['destination', 'source']: if side in rule_conf: side_conf = rule_conf[side] if dict_search_args(side_conf, 'geoip', 'country_code'): if 'address' in side_conf: raise ConfigError('Address and GeoIP cannot both be defined') if dict_search_args(side_conf, 'group', 'address_group'): raise ConfigError('Address-group and GeoIP cannot both be defined') if dict_search_args(side_conf, 'group', 'network_group'): raise ConfigError('Network-group and GeoIP cannot both be defined') if 'group' in side_conf: if {'address_group', 'network_group'} <= set(side_conf['group']): raise ConfigError('Only one address-group or network-group can be specified') for group in valid_groups: if group in side_conf['group']: group_name = side_conf['group'][group] if group_name and group_name[0] == '!': group_name = group_name[1:] fw_group = f'ipv6_{group}' if ipv6 and group in ['address_group', 'network_group'] else group error_group = fw_group.replace("_", "-") group_obj = dict_search_args(firewall, 'group', fw_group, group_name) if group_obj is None: raise ConfigError(f'Invalid {error_group} "{group_name}" on firewall rule') if not group_obj: Warning(f'{error_group} "{group_name}" has no members!') if 'port' in side_conf or dict_search_args(side_conf, 'group', 'port_group'): if 'protocol' not in rule_conf: raise ConfigError('Protocol must be defined if specifying a port or port-group') if rule_conf['protocol'] not in ['tcp', 'udp', 'tcp_udp']: raise ConfigError('Protocol must be tcp, udp, or tcp_udp when specifying a port or port-group') def verify_nested_group(group_name, group, groups, seen): if 'include' not in group: return for g in group['include']: if g not in groups: raise ConfigError(f'Nested group "{g}" does not exist') if g in seen: raise ConfigError(f'Group "{group_name}" has a circular reference') seen.append(g) if 'include' in groups[g]: verify_nested_group(g, groups[g], groups, seen) def verify(firewall): if 'config_trap' in firewall and firewall['config_trap'] == 'enable': if not firewall['trap_targets']: raise ConfigError(f'Firewall config-trap enabled but "service snmp trap-target" is not defined') if 'group' in firewall: for group_type in nested_group_types: if group_type in firewall['group']: groups = firewall['group'][group_type] for group_name, group in groups.items(): verify_nested_group(group_name, group, groups, []) for name in ['name', 'ipv6_name']: if name in firewall: for name_id, name_conf in firewall[name].items(): if 'rule' in name_conf: for rule_id, rule_conf in name_conf['rule'].items(): verify_rule(firewall, rule_conf, name == 'ipv6_name') if 'interface' in firewall: for ifname, if_firewall in firewall['interface'].items(): # verify ifname needs to be disabled, dynamic devices come up later # verify_interface_exists(ifname) for direction in ['in', 'out', 'local']: name = dict_search_args(if_firewall, direction, 'name') ipv6_name = dict_search_args(if_firewall, direction, 'ipv6_name') if name and dict_search_args(firewall, 'name', name) == None: raise ConfigError(f'Invalid firewall name "{name}" referenced on interface {ifname}') if ipv6_name and dict_search_args(firewall, 'ipv6_name', ipv6_name) == None: raise ConfigError(f'Invalid firewall ipv6-name "{ipv6_name}" referenced on interface {ifname}') if firewall['zone_policy']: for fw_name, used_names in firewall['zone_policy'].items(): for name in used_names: if dict_search_args(firewall, fw_name, name) == None: raise ConfigError(f'Firewall {fw_name.replace("_", "-")} "{name}" is still referenced in zone-policy') return None def generate(firewall): if not os.path.exists(nftables_conf): firewall['first_install'] = True if os.path.exists(nftables_zone_conf): firewall['zone_conf'] = nftables_zone_conf if os.path.exists(nftables6_zone_conf): firewall['zone6_conf'] = nftables6_zone_conf render(nftables_conf, 'firewall/nftables.j2', firewall) return None def apply_sysfs(firewall): for name, conf in sysfs_config.items(): paths = glob(conf['sysfs']) value = None if name in firewall: conf_value = firewall[name] if conf_value in conf: value = conf[conf_value] elif conf_value == 'enable': value = '1' elif conf_value == 'disable': value = '0' if value: for path in paths: with open(path, 'w') as f: f.write(value) def post_apply_trap(firewall): if 'first_install' in firewall: return None if 'config_trap' not in firewall or firewall['config_trap'] != 'enable': return None if not process_named_running('snmpd'): return None trap_username = os.getlogin() for host, target_conf in firewall['trap_targets'].items(): community = target_conf['community'] if 'community' in target_conf else 'public' port = int(target_conf['port']) if 'port' in target_conf else 162 base_cmd = f'snmptrap -v2c -c {community} {host}:{port} 0 {snmp_trap_mib}::{snmp_trap_name} ' for change_type, changes in firewall['trap_diff'].items(): for path_str, value in changes.items(): objects = [ f'mgmtEventUser s "{trap_username}"', f'mgmtEventSource i {snmp_event_source}', f'mgmtEventType i {snmp_change_type[change_type]}' ] if change_type == 'add': objects.append(f'mgmtEventCurrCfg s "{path_str} {value}"') elif change_type == 'delete': objects.append(f'mgmtEventPrevCfg s "{path_str} {value}"') elif change_type == 'change': objects.append(f'mgmtEventPrevCfg s "{path_str} {value[0]}"') objects.append(f'mgmtEventCurrCfg s "{path_str} {value[1]}"') cmd(base_cmd + ' '.join(objects)) def resync_policy_route(): # Update policy route as firewall groups were updated tmp, out = rc_cmd(policy_route_conf_script) if tmp > 0: Warning(f'Failed to re-apply policy route configuration! {out}') def apply(firewall): if 'first_install' in firewall: run('nfct helper add rpc inet tcp') run('nfct helper add rpc inet udp') run('nfct helper add tns inet tcp') install_result, output = rc_cmd(f'nft -f {nftables_conf}') if install_result == 1: raise ConfigError(f'Failed to apply firewall: {output}') # set firewall group domain-group xxx if 'group' in firewall: if 'domain_group' in firewall['group']: # T970 Enable a resolver (systemd daemon) that checks # domain-group addresses and update entries for domains by timeout # If router loaded without internet connection or for synchronization call('systemctl restart vyos-domain-group-resolve.service') for group, group_config in firewall['group']['domain_group'].items(): domains = [] if group_config.get('address') is not None: for address in group_config.get('address'): domains.append(address) # Add elements to domain-group, try to resolve domain => ip # and add elements to nft set ip_dict = get_ips_domains_dict(domains) elements = sum(ip_dict.values(), []) nft_init_set(f'D_{group}') nft_add_set_elements(f'D_{group}', elements) else: call('systemctl stop vyos-domain-group-resolve.service') apply_sysfs(firewall) if firewall['policy_resync']: resync_policy_route() if firewall['geoip_updated']: # Call helper script to Update set contents if 'name' in firewall['geoip_updated'] or 'ipv6_name' in firewall['geoip_updated']: print('Updating GeoIP. Please wait...') geoip_update(firewall) post_apply_trap(firewall) return None if __name__ == '__main__': try: c = get_config() verify(c) generate(c) apply(c) except ConfigError as e: print(e) exit(1)