#!/usr/bin/env python3 # # Copyright (C) 2018-2024 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 netifaces import interfaces from sys import exit from glob import glob from vyos.config import Config from vyos.hostsd_client import Client as hostsd_client from vyos.template import render from vyos.template import bracketize_ipv6 from vyos.utils.process import call from vyos.utils.permission import chown from vyos import ConfigError from vyos import airbag airbag.enable() pdns_rec_user_group = 'pdns' pdns_rec_run_dir = '/run/pdns-recursor' pdns_rec_lua_conf_file = f'{pdns_rec_run_dir}/recursor.conf.lua' pdns_rec_hostsd_lua_conf_file = f'{pdns_rec_run_dir}/recursor.vyos-hostsd.conf.lua' pdns_rec_hostsd_zones_file = f'{pdns_rec_run_dir}/recursor.forward-zones.conf' pdns_rec_config_file = f'{pdns_rec_run_dir}/recursor.conf' pdns_rec_systemd_override = '/run/systemd/system/pdns-recursor.service.d/override.conf' hostsd_tag = 'static' def get_config(config=None): if config: conf = config else: conf = Config() base = ['service', 'dns', 'forwarding'] if not conf.exists(base): return None dns = conf.get_config_dict(base, key_mangling=('-', '_'), no_tag_node_value_mangle=True, get_first_key=True, with_recursive_defaults=True) dns['config_file'] = pdns_rec_config_file dns['config_dir'] = os.path.dirname(pdns_rec_config_file) # some additions to the default dictionary if 'system' in dns: base_nameservers = ['system', 'name-server'] if conf.exists(base_nameservers): dns.update({'system_name_server': conf.return_values(base_nameservers)}) if 'authoritative_domain' in dns: dns['authoritative_zones'] = [] dns['authoritative_zone_errors'] = [] for node in dns['authoritative_domain']: zonedata = dns['authoritative_domain'][node] if ('disable' in zonedata) or (not 'records' in zonedata): continue zone = { 'name': node, 'file': "{}/zone.{}.conf".format(pdns_rec_run_dir, node), 'records': [], } recorddata = zonedata['records'] for rtype in [ 'a', 'aaaa', 'cname', 'mx', 'ns', 'ptr', 'txt', 'spf', 'srv', 'naptr' ]: if rtype not in recorddata: continue for subnode in recorddata[rtype]: if 'disable' in recorddata[rtype][subnode]: continue rdata = recorddata[rtype][subnode] if rtype in [ 'a', 'aaaa' ]: if not 'address' in rdata: dns['authoritative_zone_errors'].append(f'{subnode}.{node}: at least one address is required') continue if subnode == 'any': subnode = '*' for address in rdata['address']: zone['records'].append({ 'name': subnode, 'type': rtype.upper(), 'ttl': rdata['ttl'], 'value': address }) elif rtype in ['cname', 'ptr', 'ns']: if not 'target' in rdata: dns['authoritative_zone_errors'].append(f'{subnode}.{node}: target is required') continue zone['records'].append({ 'name': subnode, 'type': rtype.upper(), 'ttl': rdata['ttl'], 'value': '{}.'.format(rdata['target']) }) elif rtype == 'mx': if not 'server' in rdata: dns['authoritative_zone_errors'].append(f'{subnode}.{node}: at least one server is required') continue for servername in rdata['server']: serverdata = rdata['server'][servername] zone['records'].append({ 'name': subnode, 'type': rtype.upper(), 'ttl': rdata['ttl'], 'value': '{} {}.'.format(serverdata['priority'], servername) }) elif rtype == 'txt': if not 'value' in rdata: dns['authoritative_zone_errors'].append(f'{subnode}.{node}: at least one value is required') continue for value in rdata['value']: zone['records'].append({ 'name': subnode, 'type': rtype.upper(), 'ttl': rdata['ttl'], 'value': "\"{}\"".format(value.replace("\"", "\\\"")) }) elif rtype == 'spf': if not 'value' in rdata: dns['authoritative_zone_errors'].append(f'{subnode}.{node}: value is required') continue zone['records'].append({ 'name': subnode, 'type': rtype.upper(), 'ttl': rdata['ttl'], 'value': '"{}"'.format(rdata['value'].replace("\"", "\\\"")) }) elif rtype == 'srv': if not 'entry' in rdata: dns['authoritative_zone_errors'].append(f'{subnode}.{node}: at least one entry is required') continue for entryno in rdata['entry']: entrydata = rdata['entry'][entryno] if not 'hostname' in entrydata: dns['authoritative_zone_errors'].append(f'{subnode}.{node}: hostname is required for entry {entryno}') continue if not 'port' in entrydata: dns['authoritative_zone_errors'].append(f'{subnode}.{node}: port is required for entry {entryno}') continue zone['records'].append({ 'name': subnode, 'type': rtype.upper(), 'ttl': rdata['ttl'], 'value': '{} {} {} {}.'.format(entrydata['priority'], entrydata['weight'], entrydata['port'], entrydata['hostname']) }) elif rtype == 'naptr': if not 'rule' in rdata: dns['authoritative_zone_errors'].append(f'{subnode}.{node}: at least one rule is required') continue for ruleno in rdata['rule']: ruledata = rdata['rule'][ruleno] flags = "" if 'lookup-srv' in ruledata: flags += "S" if 'lookup-a' in ruledata: flags += "A" if 'resolve-uri' in ruledata: flags += "U" if 'protocol-specific' in ruledata: flags += "P" if 'order' in ruledata: order = ruledata['order'] else: order = ruleno if 'regexp' in ruledata: regexp= ruledata['regexp'].replace("\"", "\\\"") else: regexp = '' if ruledata['replacement']: replacement = '{}.'.format(ruledata['replacement']) else: replacement = '' zone['records'].append({ 'name': subnode, 'type': rtype.upper(), 'ttl': rdata['ttl'], 'value': '{} {} "{}" "{}" "{}" {}'.format(order, ruledata['preference'], flags, ruledata['service'], regexp, replacement) }) dns['authoritative_zones'].append(zone) return dns def verify(dns): # bail out early - looks like removal from running config if not dns: return None if 'listen_address' not in dns: raise ConfigError('DNS forwarding requires a listen-address') if 'allow_from' not in dns: raise ConfigError('DNS forwarding requires an allow-from network') # we can not use dict_search() when testing for domain servers # as a domain will contains dot's which is out dictionary delimiter. if 'domain' in dns: for domain in dns['domain']: if 'name_server' not in dns['domain'][domain]: raise ConfigError(f'No server configured for domain {domain}!') if 'dns64_prefix' in dns: dns_prefix = dns['dns64_prefix'].split('/')[1] # RFC 6147 requires prefix /96 if int(dns_prefix) != 96: raise ConfigError('DNS 6to4 prefix must be of length /96') if ('authoritative_zone_errors' in dns) and dns['authoritative_zone_errors']: for error in dns['authoritative_zone_errors']: print(error) raise ConfigError('Invalid authoritative records have been defined') if 'system' in dns: if not 'system_name_server' in dns: print('Warning: No "system name-server" configured') return None def generate(dns): # bail out early - looks like removal from running config if not dns: return None render(pdns_rec_systemd_override, 'dns-forwarding/override.conf.j2', dns) render(pdns_rec_config_file, 'dns-forwarding/recursor.conf.j2', dns, user=pdns_rec_user_group, group=pdns_rec_user_group) render(pdns_rec_config_file, 'dns-forwarding/recursor.conf.j2', dns, user=pdns_rec_user_group, group=pdns_rec_user_group) render(pdns_rec_lua_conf_file, 'dns-forwarding/recursor.conf.lua.j2', dns, user=pdns_rec_user_group, group=pdns_rec_user_group) for zone_filename in glob(f'{pdns_rec_run_dir}/zone.*.conf'): os.unlink(zone_filename) if 'authoritative_zones' in dns: for zone in dns['authoritative_zones']: render(zone['file'], 'dns-forwarding/recursor.zone.conf.j2', zone, user=pdns_rec_user_group, group=pdns_rec_user_group) # if vyos-hostsd didn't create its files yet, create them (empty) for file in [pdns_rec_hostsd_lua_conf_file, pdns_rec_hostsd_zones_file]: with open(file, 'a'): pass chown(file, user=pdns_rec_user_group, group=pdns_rec_user_group) return None def apply(dns): systemd_service = 'pdns-recursor.service' # Reload systemd manager configuration call('systemctl daemon-reload') if not dns: # DNS forwarding is removed in the commit call(f'systemctl stop {systemd_service}') if os.path.isfile(pdns_rec_config_file): os.unlink(pdns_rec_config_file) for zone_filename in glob(f'{pdns_rec_run_dir}/zone.*.conf'): os.unlink(zone_filename) else: ### first apply vyos-hostsd config hc = hostsd_client() # add static nameservers to hostsd so they can be joined with other # sources hc.delete_name_servers([hostsd_tag]) if 'name_server' in dns: # 'name_server' is of the form # {'192.0.2.1': {'port': 53}, '2001:db8::1': {'port': 853}, ...} # canonicalize them as ['192.0.2.1:53', '[2001:db8::1]:853', ...] nslist = [(lambda h, p: f"{bracketize_ipv6(h)}:{p['port']}")(h, p) for (h, p) in dns['name_server'].items()] hc.add_name_servers({hostsd_tag: nslist}) # delete all nameserver tags hc.delete_name_server_tags_recursor(hc.get_name_server_tags_recursor()) ## add nameserver tags - the order determines the nameserver order! # our own tag (static) hc.add_name_server_tags_recursor([hostsd_tag]) if 'system' in dns: hc.add_name_server_tags_recursor(['system']) else: hc.delete_name_server_tags_recursor(['system']) # add dhcp nameserver tags for configured interfaces if 'system_name_server' in dns: for interface in dns['system_name_server']: # system_name_server key contains both IP addresses and interface # names (DHCP) to use DNS servers. We need to check if the # value is an interface name - only if this is the case, add the # interface based DNS forwarder. if interface in interfaces(): hc.add_name_server_tags_recursor(['dhcp-' + interface, 'dhcpv6-' + interface ]) # hostsd will generate the forward-zones file # the list and keys() are required as get returns a dict, not list hc.delete_forward_zones(list(hc.get_forward_zones().keys())) if 'domain' in dns: zones = dns['domain'] for domain in zones.keys(): # 'name_server' is of the form # {'192.0.2.1': {'port': 53}, '2001:db8::1': {'port': 853}, ...} # canonicalize them as ['192.0.2.1:53', '[2001:db8::1]:853', ...] zones[domain]['name_server'] = [(lambda h, p: f"{bracketize_ipv6(h)}:{p['port']}")(h, p) for (h, p) in zones[domain]['name_server'].items()] hc.add_forward_zones(zones) # hostsd generates NTAs for the authoritative zones # the list and keys() are required as get returns a dict, not list hc.delete_authoritative_zones(list(hc.get_authoritative_zones())) if 'authoritative_zones' in dns: hc.add_authoritative_zones(list(map(lambda zone: zone['name'], dns['authoritative_zones']))) # call hostsd to generate forward-zones and its lua-config-file hc.apply() ### finally (re)start pdns-recursor call(f'systemctl reload-or-restart {systemd_service}') if __name__ == '__main__': try: c = get_config() verify(c) generate(c) apply(c) except ConfigError as e: print(e) exit(1)