self.delete_record(self.custom_zone, "testrecord", record_type_str, record_str)
self.assert_num_records(self.custom_zone, "testrecord", record_type_str, 0)
- def test_dns_tombstoned(self):
- """
- See what happens when we set a record to be tombstoned.
- """
+ def test_dns_tombstoned_zero_timestamp(self):
+ """What happens with a zero EntombedTime tombstone?"""
+ # A zero-timestamp tombstone record has a special meaning for
+ # dns_common_replace(), which is the function exposed by
+ # samdb.dns_replace_by_dn(), and which is *NOT* a general
+ # purpose record replacement function but a specialised part
+ # of the dns update mechanism (for both DLZ and internal).
+ #
+ # In the earlier stages of handling updates, a record that
+ # needs to be deleted is set to be a tombstone with a zero
+ # timestamp. dns_common_replace() notices this specific
+ # marker, and if there are no other records, marks the node as
+ # tombstoned, in the process adding a "real" tombstone.
+ #
+ # If the tombstone has a non-zero timestamp, as you'll see in
+ # the next test, dns_common_replace will decide that the node
+ # is already tombstoned, and that no action needs to be taken.
+ #
+ # This test has worked historically, entirely by accident, as
+ # changing the wType appears to
record_str = "192.168.50.50"
- record_type_str = "A"
- self.add_record(self.custom_zone, "testrecord", record_type_str, record_str)
+ self.add_record(self.custom_zone, "testrecord", 'A', record_str)
dn, record = self.get_record_from_db(self.custom_zone, "testrecord")
record.wType = dnsp.DNS_TYPE_TOMBSTONE
- res = self.samdb.dns_replace_by_dn(dn, [record])
- if res is not None:
- self.fail("Unable to update dns record to be tombstoned.")
+ record.data = 0
+ self.samdb.dns_replace_by_dn(dn, [record])
+
+ # there should be no A record, and one TOMBSTONE record.
+ self.assert_num_records(self.custom_zone, "testrecord", 'A', 0)
+ # we can't make assertions about the tombstone count based on
+ # RPC calls, as ther are no tombstones in RPCs (there is
+ # "DNS_TYPE_ZERO" instead). Nor do tombstones show up if we
+ # use DNS_TYPE_ALL.
+ self.assert_num_records(self.custom_zone, "testrecord", 'ALL', 0)
+
+ # But we can use LDAP:
+ records = self.ldap_get_records(self.custom_zone, "testrecord")
+ self.assertEqual(len(records), 1)
+ r = records[0]
+ self.assertEqual(r.wType, dnsp.DNS_TYPE_TOMBSTONE)
+ self.assertGreater(r.data, 1e17) # ~ October 1916
+
+ # this should fail, because no A records.
+ self.delete_record(self.custom_zone, "testrecord", 'A', record_str,
+ assertion=False)
+
+ def test_dns_tombstoned_nonzero_timestamp(self):
+ """See what happens when we set a record to be tombstoned with an
+ EntombedTime timestamp.
+ """
+ # Because this tombstone has a non-zero EntombedTime,
+ # dns_common_replace() will decide the node was already
+ # tombstoned and there is nothing to be done, leaving the A
+ # record where it was.
- self.assert_num_records(self.custom_zone, "testrecord", record_type_str)
- self.delete_record(self.custom_zone, "testrecord", record_type_str, record_str)
- self.assert_num_records(self.custom_zone, "testrecord", record_type_str, 0)
+ record_str = "192.168.50.50"
+ self.add_record(self.custom_zone, "testrecord", 'A', record_str)
+
+ dn, record = self.get_record_from_db(self.custom_zone, "testrecord")
+ record.wType = dnsp.DNS_TYPE_TOMBSTONE
+ record.data = 0x123456789A
+ self.samdb.dns_replace_by_dn(dn, [record])
+
+ # there should be the A record and no TOMBSTONE
+ self.assert_num_records(self.custom_zone, "testrecord", 'A', 1)
+ self.assert_num_records(self.custom_zone, "testrecord", 'TOMBSTONE', 0)
+ # this should succeed
+ self.delete_record(self.custom_zone, "testrecord", 'A', record_str,
+ assertion=True)
+ self.assert_num_records(self.custom_zone, "testrecord", 'TOMBSTONE', 0)
+ self.assert_num_records(self.custom_zone, "testrecord", 'A', 0)
def get_record_from_db(self, zone_name, record_name):
"""
rec = ndr_unpack(dnsp.DnssrvRpcRecord, old_packed_record["dnsRecord"][0])
return (old_packed_record.dn, rec)
+ def ldap_get_records(self, zone, name):
+ zone_dn = (f"DC={zone},CN=MicrosoftDNS,DC=DomainDNSZones,"
+ f"{self.samdb.get_default_basedn()}")
+
+ expr = f"(&(objectClass=dnsNode)(name={name}))"
+ nodes = self.samdb.search(base=zone_dn,
+ scope=ldb.SCOPE_SUBTREE,
+ expression=expr,
+ attrs=["dnsRecord"])
+
+ records = nodes[0].get('dnsRecord')
+ return [ndr_unpack(dnsp.DnssrvRpcRecord, r) for r in records]
+
def test_duplicate_matching(self):
"""
Make sure that records which should be distinct from each other or duplicate