diff --git a/synapse/http/endpoint.py b/synapse/http/endpoint.py
index 87639b9151..00572c2897 100644
--- a/synapse/http/endpoint.py
+++ b/synapse/http/endpoint.py
@@ -12,8 +12,6 @@
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
-import socket
-
from twisted.internet.endpoints import HostnameEndpoint, wrapClientTLS
from twisted.internet import defer, reactor
from twisted.internet.error import ConnectError
@@ -33,7 +31,7 @@ SERVER_CACHE = {}
# our record of an individual server which can be tried to reach a destination.
#
-# "host" is actually a dotted-quad or ipv6 address string. Except when there's
+# "host" is the hostname acquired from the SRV record. Except when there's
# no SRV record, in which case it is the original hostname.
_Server = collections.namedtuple(
"_Server", "priority weight host port expires"
@@ -297,20 +295,13 @@ def resolve_service(service_name, dns_client=client, cache=SERVER_CACHE, clock=t
payload = answer.payload
- hosts = yield _get_hosts_for_srv_record(
- dns_client, str(payload.target)
- )
-
- for (ip, ttl) in hosts:
- host_ttl = min(answer.ttl, ttl)
-
- servers.append(_Server(
- host=ip,
- port=int(payload.port),
- priority=int(payload.priority),
- weight=int(payload.weight),
- expires=int(clock.time()) + host_ttl,
- ))
+ servers.append(_Server(
+ host=str(payload.target),
+ port=int(payload.port),
+ priority=int(payload.priority),
+ weight=int(payload.weight),
+ expires=int(clock.time()) + answer.ttl,
+ ))
servers.sort()
cache[service_name] = list(servers)
@@ -328,81 +319,3 @@ def resolve_service(service_name, dns_client=client, cache=SERVER_CACHE, clock=t
raise e
defer.returnValue(servers)
-
-
-@defer.inlineCallbacks
-def _get_hosts_for_srv_record(dns_client, host):
- """Look up each of the hosts in a SRV record
-
- Args:
- dns_client (twisted.names.dns.IResolver):
- host (basestring): host to look up
-
- Returns:
- Deferred[list[(str, int)]]: a list of (host, ttl) pairs
-
- """
- ip4_servers = []
- ip6_servers = []
-
- def cb(res):
- # lookupAddress and lookupIP6Address return a three-tuple
- # giving the answer, authority, and additional sections of the
- # response.
- #
- # we only care about the answers.
-
- return res[0]
-
- def eb(res, record_type):
- if res.check(DNSNameError):
- return []
- logger.warn("Error looking up %s for %s: %s", record_type, host, res)
- return res
-
- # no logcontexts here, so we can safely fire these off and gatherResults
- d1 = dns_client.lookupAddress(host).addCallbacks(
- cb, eb, errbackArgs=("A", ))
- d2 = dns_client.lookupIPV6Address(host).addCallbacks(
- cb, eb, errbackArgs=("AAAA", ))
- results = yield defer.DeferredList(
- [d1, d2], consumeErrors=True)
-
- # if all of the lookups failed, raise an exception rather than blowing out
- # the cache with an empty result.
- if results and all(s == defer.FAILURE for (s, _) in results):
- defer.returnValue(results[0][1])
-
- for (success, result) in results:
- if success == defer.FAILURE:
- continue
-
- for answer in result:
- if not answer.payload:
- continue
-
- try:
- if answer.type == dns.A:
- ip = answer.payload.dottedQuad()
- ip4_servers.append((ip, answer.ttl))
- elif answer.type == dns.AAAA:
- ip = socket.inet_ntop(
- socket.AF_INET6, answer.payload.address,
- )
- ip6_servers.append((ip, answer.ttl))
- else:
- # the most likely candidate here is a CNAME record.
- # rfc2782 says srvs may not point to aliases.
- logger.warn(
- "Ignoring unexpected DNS record type %s for %s",
- answer.type, host,
- )
- continue
- except Exception as e:
- logger.warn("Ignoring invalid DNS response for %s: %s",
- host, e)
- continue
-
- # keep the ipv4 results before the ipv6 results, mostly to match historical
- # behaviour.
- defer.returnValue(ip4_servers + ip6_servers)
diff --git a/tests/test_dns.py b/tests/test_dns.py
index d08b0f4333..af607d626f 100644
--- a/tests/test_dns.py
+++ b/tests/test_dns.py
@@ -33,8 +33,6 @@ class DnsTestCase(unittest.TestCase):
service_name = "test_service.example.com"
host_name = "example.com"
- ip_address = "127.0.0.1"
- ip6_address = "::1"
answer_srv = dns.RRHeader(
type=dns.SRV,
@@ -43,29 +41,9 @@ class DnsTestCase(unittest.TestCase):
)
)
- answer_a = dns.RRHeader(
- type=dns.A,
- payload=dns.Record_A(
- address=ip_address,
- )
- )
-
- answer_aaaa = dns.RRHeader(
- type=dns.AAAA,
- payload=dns.Record_AAAA(
- address=ip6_address,
- )
- )
-
dns_client_mock.lookupService.return_value = defer.succeed(
([answer_srv], None, None),
)
- dns_client_mock.lookupAddress.return_value = defer.succeed(
- ([answer_a], None, None),
- )
- dns_client_mock.lookupIPV6Address.return_value = defer.succeed(
- ([answer_aaaa], None, None),
- )
cache = {}
@@ -74,13 +52,10 @@ class DnsTestCase(unittest.TestCase):
)
dns_client_mock.lookupService.assert_called_once_with(service_name)
- dns_client_mock.lookupAddress.assert_called_once_with(host_name)
- dns_client_mock.lookupIPV6Address.assert_called_once_with(host_name)
- self.assertEquals(len(servers), 2)
+ self.assertEquals(len(servers), 1)
self.assertEquals(servers, cache[service_name])
- self.assertEquals(servers[0].host, ip_address)
- self.assertEquals(servers[1].host, ip6_address)
+ self.assertEquals(servers[0].host, host_name)
@defer.inlineCallbacks
def test_from_cache_expired_and_dns_fail(self):
|
