import dns.message import dns.name import dns.opcode import dns.query import dns.rdatatype import dns.rdataclass import dns.rrset import dns.tsig from django.conf import settings from django.utils import timezone from django.db import close_old_connections, OperationalError from netbox.jobs import JobRunner from netbox_dns.models import View, Zone, Record from netbox_dns_bridge.utils import get_logger from netbox_dns_bridge.models import SeenTransferClients, IntegerKeyValueSetting LOGGER = get_logger(__name__) SETTINGS = settings.PLUGINS_CONFIG.get("netbox_dns_bridge", {}) def _load_tsig_key(view_name: str) -> dns.tsig.Key: tsig_keys = SETTINGS.get("tsig_keys", {}) if view_name not in tsig_keys: raise RuntimeError(f"No TSIG key configured for view '{view_name}'") key_data = tsig_keys[view_name] raw_key_name = key_data.get("keyname") secret = key_data.get("secret") algorithm = key_data.get("algorithm") if not algorithm: raise RuntimeError( f"Missing 'algorithm' in TSIG key configuration for view '{view_name}'" ) if not raw_key_name or not secret: raise RuntimeError(f"Incomplete TSIG key configuration for view '{view_name}'") key_name = dns.name.from_text(raw_key_name, origin=None).canonicalize() if not key_name.is_absolute(): key_name = key_name.concatenate(dns.name.root) return dns.tsig.Key(name=key_name, secret=secret, algorithm=algorithm) class SendClientDNSNotify(JobRunner): class Meta: name = "Send DNS NOTIFY" def run(self, *args, **kwargs): notify_over_tcp = SETTINGS.get("notify_over_tcp", False) port = SETTINGS.get("notify_client_port", 53) view_name = kwargs["view_name"] try: catz_serial = IntegerKeyValueSetting.objects.get( key="catalog-zone-soa-serial" ).value zones = [ (kwargs["zone_name"], kwargs["soa_serial"]), ("catz", catz_serial), (f"{view_name}.catz", catz_serial), ] view = View.objects.get(name=view_name) tsig_key = _load_tsig_key(view_name) cutoff_hours = SETTINGS.get("notify_client_alive_threshold_hours", 24) seen_cutoff = timezone.now() - timezone.timedelta(hours=cutoff_hours) clients = SeenTransferClients.objects.filter( view=view, last_seen__gte=seen_cutoff ) for zone_name, soa_serial in zones: zone_name = dns.name.from_text(zone_name, dns.name.root).to_text() msg = dns.message.make_query(zone_name, dns.rdatatype.SOA) msg.flags |= dns.flags.AA # = 0 msg.set_opcode(dns.opcode.NOTIFY) soa_rdata = dns.rdata.from_text( dns.rdataclass.IN, dns.rdatatype.SOA, f"invalid. invalid. {soa_serial} 60 10 1209600 0", ) soa_rrset = dns.rrset.from_rdata(zone_name, 0, soa_rdata) msg.answer.append(soa_rrset) msg.use_tsig(keyring={tsig_key.name: tsig_key}, keyname=tsig_key.name) for client in clients: try: if notify_over_tcp: LOGGER.debug("Sending NOTIFY over TCP") dns.query.tcp(msg, client.source_ip, port=port, timeout=2) else: LOGGER.debug("Sending NOTIFY over UDP") dns.query.udp(msg, client.source_ip, port=port, timeout=2) LOGGER.info( f"NOTIFY sent: {client.source_ip} {view_name}/{zone_name} {soa_serial}" ) except Exception as e: LOGGER.error( f"NOTIFY failed: {client.source_ip}:{port}" f" {view_name}/{zone_name} {soa_serial}: {e}" ) except IntegerKeyValueSetting.DoesNotExist as e: LOGGER.error(f"Failed to get catalog zone serial: {e}") except OperationalError as e: LOGGER.error(f"NOTIFY failed due to unexpected error: {e}") close_old_connections() class SendNSNotify(JobRunner): """Send a NOTIFY straight to a zone's own nameservers. Unlike ``SendClientDNSNotify`` (which notifies clients that previously queried the transfer endpoint), this job resolves the addresses of the zone's configured nameservers from NetBox DNS itself and notifies each of them so they pick up the changed zone quickly. """ class Meta: name = "Send DNS NOTIFY to zone nameservers" def run(self, *args, **kwargs): notify_over_tcp = SETTINGS.get("notify_over_tcp", False) port = SETTINGS.get("notify_ns_port", 53) view_name = kwargs["view_name"] zone_name = kwargs["zone_name"] soa_serial = kwargs["soa_serial"] try: zone = Zone.objects.get(pk=kwargs["zone_id"]) except Zone.DoesNotExist: LOGGER.error(f"NS NOTIFY: zone id {kwargs['zone_id']} no longer exists") return except OperationalError as e: LOGGER.error(f"NS NOTIFY failed due to unexpected error: {e}") close_old_connections() return ns_targets = _resolve_zone_nameserver_ips(zone) if not ns_targets: LOGGER.warning( f"NS NOTIFY: no nameserver addresses found in NetBox DNS for " f"{view_name}/{zone_name} — skipping" ) return try: tsig_key = _load_tsig_key(view_name) except RuntimeError as e: LOGGER.error(f"NS NOTIFY aborted for {view_name}/{zone_name}: {e}") return fqdn = dns.name.from_text(zone_name, dns.name.root).to_text() msg = dns.message.make_query(fqdn, dns.rdatatype.SOA) msg.flags |= dns.flags.AA msg.set_opcode(dns.opcode.NOTIFY) soa_rdata = dns.rdata.from_text( dns.rdataclass.IN, dns.rdatatype.SOA, f"invalid. invalid. {soa_serial} 60 10 1209600 0", ) msg.answer.append(dns.rrset.from_rdata(fqdn, 0, soa_rdata)) msg.use_tsig(keyring={tsig_key.name: tsig_key}, keyname=tsig_key.name) for ip in ns_targets: try: if notify_over_tcp: LOGGER.debug("Sending NS NOTIFY over TCP") dns.query.tcp(msg, ip, port=port, timeout=2) else: LOGGER.debug("Sending NS NOTIFY over UDP") dns.query.udp(msg, ip, port=port, timeout=2) LOGGER.info(f"NS NOTIFY sent: {ip} {view_name}/{fqdn} {soa_serial}") except Exception as e: LOGGER.error( f"NS NOTIFY failed: {ip} {view_name}/{fqdn} {soa_serial}: {e}" ) def _get_soa_serial(zone: Zone): """Return the current SOA serial of a zone parsed from its SOA record.""" try: soa_record = Record.objects.filter(zone=zone, type="SOA", active=True).first() if soa_record is None: LOGGER.error(f"Zone {zone.name} has no active SOA record — skipping NOTIFY") return None return int(soa_record.value.split()[2]) except OperationalError as e: LOGGER.error(f"DB ERROR while fetching SOA for zone {zone.name}: {e}") close_old_connections() return None except (ValueError, IndexError) as e: LOGGER.error(f"Failed to parse SOA serial for zone {zone.name}: {e}") return None def _resolve_zone_nameserver_ips(zone: Zone) -> list: """Resolve the zone's nameserver hostnames to IPs using NetBox DNS records. For each nameserver assigned to the zone, matching active A/AAAA records within the same view are looked up in NetBox DNS. Returns a de-duplicated, order-preserving list of IP addresses. """ ips = [] try: nameservers = list(zone.nameservers.all()) view = zone.view for nameserver in nameservers: fqdn = dns.name.from_text(nameserver.name, dns.name.root).to_text() # Match both with and without a trailing dot to be resilient against # how the fqdn is stored on the Record model. candidates = {fqdn, fqdn.rstrip(".")} records = Record.objects.filter( fqdn__in=list(candidates), type__in=["A", "AAAA"], active=True, zone__view=view, ) for record in records: if record.value not in ips: ips.append(record.value) except OperationalError as e: LOGGER.error(f"DB ERROR while resolving nameservers for {zone.name}: {e}") close_old_connections() return ips def schedule_client_notify(zone: Zone): soa_serial = _get_soa_serial(zone) if soa_serial is None: return SendClientDNSNotify.enqueue( zone_name=zone.name, view_name=zone.view.name, soa_serial=soa_serial, ) def schedule_ns_notify(zone: Zone): soa_serial = _get_soa_serial(zone) if soa_serial is None: return SendNSNotify.enqueue( zone_id=zone.pk, zone_name=zone.name, view_name=zone.view.name, soa_serial=soa_serial, )