From 44be7513bff501055cc2e667a5cca3fb87c23f70 Mon Sep 17 00:00:00 2001 From: Richard van der Hoff Date: Mon, 21 Jan 2019 23:27:57 +0000 Subject: [PATCH 1/8] MatrixFederationAgent Pull the magic that is currently in matrix_federation_endpoint and friends into an agent-like thing --- .../federation/matrix_federation_agent.py | 114 ++++++++++++++++++ synapse/http/federation/srv_resolver.py | 33 +++++ 2 files changed, 147 insertions(+) create mode 100644 synapse/http/federation/matrix_federation_agent.py diff --git a/synapse/http/federation/matrix_federation_agent.py b/synapse/http/federation/matrix_federation_agent.py new file mode 100644 index 000000000000..32bfd68ed168 --- /dev/null +++ b/synapse/http/federation/matrix_federation_agent.py @@ -0,0 +1,114 @@ +# -*- coding: utf-8 -*- +# Copyright 2019 New Vector Ltd +# +# Licensed under the Apache License, Version 2.0 (the "License"); +# you may not use this file except in compliance with the License. +# You may obtain a copy of the License at +# +# http://www.apache.org/licenses/LICENSE-2.0 +# +# Unless required by applicable law or agreed to in writing, software +# distributed under the License is distributed on an "AS IS" BASIS, +# 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 logging + +from zope.interface import implementer + +from twisted.internet import defer +from twisted.internet.endpoints import HostnameEndpoint, wrapClientTLS +from twisted.web.client import URI, Agent, HTTPConnectionPool +from twisted.web.iweb import IAgent + +from synapse.http.endpoint import parse_server_name +from synapse.http.federation.srv_resolver import pick_server_from_list, resolve_service +from synapse.util.logcontext import make_deferred_yieldable + +logger = logging.getLogger(__name__) + + +@implementer(IAgent) +class MatrixFederationAgent(object): + """An Agent-like thing which provides a `request` method which will look up a matrix + server and send an HTTP request to it. + + Doesn't implement any retries. (Those are done in MatrixFederationHttpClient.) + + Args: + reactor (IReactor): twisted reactor to use for underlying requests + tls_client_options_factory (ClientTLSOptionsFactory|None): + factory to use for fetching client tls options, or none to disable TLS. + """ + + def __init__(self, reactor, tls_client_options_factory): + self._reactor = reactor + self._tls_client_options_factory = tls_client_options_factory + + self._pool = HTTPConnectionPool(reactor) + self._pool.retryAutomatically = False + self._pool.maxPersistentPerHost = 5 + self._pool.cachedConnectionTimeout = 2 * 60 + + @defer.inlineCallbacks + def request(self, method, uri, headers=None, bodyProducer=None): + """ + Args: + method (bytes): HTTP method: GET/POST/etc + + uri (bytes): Absolute URI to be retrieved + + headers (twisted.web.http_headers.Headers|None): + HTTP headers to send with the request, or None to + send no extra headers. + + bodyProducer (twisted.web.iweb.IBodyProducer|None): + An object which can generate bytes to make up the + body of this request (for example, the properly encoded contents of + a file for a file upload). Or None if the request is to have + no body. + + Returns: + Deferred[twisted.web.iweb.IResponse]: + fires when the header of the response has been received (regardless of the + response status code). Fails if there is any problem which prevents that + response from being received (including problems that prevent the request + from being sent). + """ + + parsed_uri = URI.fromBytes(uri) + server_name_bytes = parsed_uri.netloc + host, port = parse_server_name(server_name_bytes.decode("ascii")) + + # XXX disabling TLS is really only supported here for the benefit of the + # unit tests. We should make the UTs cope with TLS rather than having to make + # the code support the unit tests. + if self._tls_client_options_factory is None: + tls_options = None + else: + tls_options = self._tls_client_options_factory.get_options(host) + + if port is not None: + target = (host, port) + else: + server_list = yield resolve_service(server_name_bytes) + if not server_list: + target = (host, 8448) + logger.debug("No SRV record for %s, using %s", host, target) + else: + target = pick_server_from_list(server_list) + + class EndpointFactory(object): + @staticmethod + def endpointForURI(_uri): + logger.info("Connecting to %s:%s", target[0], target[1]) + ep = HostnameEndpoint(self._reactor, host=target[0], port=target[1]) + if tls_options is not None: + ep = wrapClientTLS(tls_options, ep) + return ep + + agent = Agent.usingEndpointFactory(self._reactor, EndpointFactory(), self._pool) + res = yield make_deferred_yieldable( + agent.request(method, uri, headers, bodyProducer) + ) + defer.returnValue(res) diff --git a/synapse/http/federation/srv_resolver.py b/synapse/http/federation/srv_resolver.py index c49b82c39433..ded0b32832b8 100644 --- a/synapse/http/federation/srv_resolver.py +++ b/synapse/http/federation/srv_resolver.py @@ -15,6 +15,7 @@ # limitations under the License. import logging +import random import time import attr @@ -51,6 +52,38 @@ class Server(object): expires = attr.ib(default=0) +def pick_server_from_list(server_list): + """Randomly choose a server from the server list + + Args: + server_list (list[Server]): list of candidate servers + + Returns: + Tuple[bytes, int]: (host, port) pair for the chosen server + """ + if not server_list: + raise RuntimeError("pick_server_from_list called with empty list") + + # TODO: currently we only use the lowest-priority servers. We should maintain a + # cache of servers known to be "down" and filter them out + + min_priority = min(s.priority for s in server_list) + eligible_servers = list(s for s in server_list if s.priority == min_priority) + total_weight = sum(s.weight for s in eligible_servers) + target_weight = random.randint(0, total_weight) + + for s in eligible_servers: + target_weight -= s.weight + + if target_weight <= 0: + return s.host, s.port + + # this should be impossible. + raise RuntimeError( + "pick_server_from_list got to end of eligible server list.", + ) + + @defer.inlineCallbacks def resolve_service(service_name, dns_client=client, cache=SERVER_CACHE, clock=time): """Look up a SRV record, with caching From 7871146667afd76576939c91986a8f8bacb49446 Mon Sep 17 00:00:00 2001 From: Richard van der Hoff Date: Mon, 21 Jan 2019 23:29:47 +0000 Subject: [PATCH 2/8] Make MatrixFederationClient use MatrixFederationAgent ... instead of the matrix_federation_endpoint --- synapse/http/matrixfederationclient.py | 37 +++------- tests/http/test_fedclient.py | 96 ++++++++++++++++++++++++++ 2 files changed, 106 insertions(+), 27 deletions(-) diff --git a/synapse/http/matrixfederationclient.py b/synapse/http/matrixfederationclient.py index 250bb1ef912a..980e912348cc 100644 --- a/synapse/http/matrixfederationclient.py +++ b/synapse/http/matrixfederationclient.py @@ -32,7 +32,7 @@ from twisted.internet.error import DNSLookupError from twisted.internet.task import _EPSILON, Cooperator from twisted.web._newclient import ResponseDone -from twisted.web.client import Agent, FileBodyProducer, HTTPConnectionPool +from twisted.web.client import FileBodyProducer from twisted.web.http_headers import Headers import synapse.metrics @@ -44,7 +44,7 @@ RequestSendFailed, SynapseError, ) -from synapse.http.endpoint import matrix_federation_endpoint +from synapse.http.federation.matrix_federation_agent import MatrixFederationAgent from synapse.util.async_helpers import timeout_deferred from synapse.util.logcontext import make_deferred_yieldable from synapse.util.metrics import Measure @@ -66,20 +66,6 @@ MAXINT = sys.maxint -class MatrixFederationEndpointFactory(object): - def __init__(self, hs): - self.reactor = hs.get_reactor() - self.tls_client_options_factory = hs.tls_client_options_factory - - def endpointForURI(self, uri): - destination = uri.netloc.decode('ascii') - - return matrix_federation_endpoint( - self.reactor, destination, timeout=10, - tls_client_options_factory=self.tls_client_options_factory - ) - - _next_id = 1 @@ -187,12 +173,10 @@ def __init__(self, hs): self.signing_key = hs.config.signing_key[0] self.server_name = hs.hostname reactor = hs.get_reactor() - pool = HTTPConnectionPool(reactor) - pool.retryAutomatically = False - pool.maxPersistentPerHost = 5 - pool.cachedConnectionTimeout = 2 * 60 - self.agent = Agent.usingEndpointFactory( - reactor, MatrixFederationEndpointFactory(hs), pool=pool + + self.agent = MatrixFederationAgent( + hs.get_reactor(), + hs.tls_client_options_factory, ) self.clock = hs.get_clock() self._store = hs.get_datastore() @@ -316,9 +300,9 @@ def _send_request( headers_dict[b"Authorization"] = auth_headers logger.info( - "{%s} [%s] Sending request: %s %s", + "{%s} [%s] Sending request: %s %s; timeout %fs", request.txn_id, request.destination, request.method, - url_str, + url_str, _sec_timeout, ) try: @@ -338,12 +322,11 @@ def _send_request( reactor=self.hs.get_reactor(), ) - response = yield make_deferred_yieldable( - request_deferred, - ) + response = yield request_deferred except DNSLookupError as e: raise_from(RequestSendFailed(e, can_retry=retry_on_dns_fail), e) except Exception as e: + logger.info("Failed to send request: %s", e) raise_from(RequestSendFailed(e, can_retry=True), e) logger.info( diff --git a/tests/http/test_fedclient.py b/tests/http/test_fedclient.py index 8426eee400be..d37f8f998155 100644 --- a/tests/http/test_fedclient.py +++ b/tests/http/test_fedclient.py @@ -15,6 +15,7 @@ from mock import Mock +from twisted.internet import defer from twisted.internet.defer import TimeoutError from twisted.internet.error import ConnectingCancelledError, DNSLookupError from twisted.test.proto_helpers import StringTransport @@ -26,11 +27,20 @@ MatrixFederationHttpClient, MatrixFederationRequest, ) +from synapse.util.logcontext import LoggingContext from tests.server import FakeTransport from tests.unittest import HomeserverTestCase +def check_logcontext(context): + current = LoggingContext.current_context() + if current is not context: + raise AssertionError( + "Expected logcontext %s but was %s" % (context, current), + ) + + class FederationClientTests(HomeserverTestCase): def make_homeserver(self, reactor, clock): @@ -43,6 +53,70 @@ def prepare(self, reactor, clock, homeserver): self.cl = MatrixFederationHttpClient(self.hs) self.reactor.lookups["testserv"] = "1.2.3.4" + def test_client_get(self): + """ + happy-path test of a GET request + """ + @defer.inlineCallbacks + def do_request(): + with LoggingContext("one") as context: + fetch_d = self.cl.get_json("testserv:8008", "foo/bar") + + # Nothing happened yet + self.assertNoResult(fetch_d) + + # should have reset logcontext to the sentinel + check_logcontext(LoggingContext.sentinel) + + try: + fetch_res = yield fetch_d + defer.returnValue(fetch_res) + finally: + check_logcontext(context) + + test_d = do_request() + + self.pump() + + # Nothing happened yet + self.assertNoResult(test_d) + + # Make sure treq is trying to connect + clients = self.reactor.tcpClients + self.assertEqual(len(clients), 1) + (host, port, factory, _timeout, _bindAddress) = clients[0] + self.assertEqual(host, '1.2.3.4') + self.assertEqual(port, 8008) + + # complete the connection and wire it up to a fake transport + protocol = factory.buildProtocol(None) + transport = StringTransport() + protocol.makeConnection(transport) + + # that should have made it send the request to the transport + self.assertRegex(transport.value(), b"^GET /foo/bar") + + # Deferred is still without a result + self.assertNoResult(test_d) + + # Send it the HTTP response + res_json = '{ "a": 1 }'.encode('ascii') + protocol.dataReceived( + b"HTTP/1.1 200 OK\r\n" + b"Server: Fake\r\n" + b"Content-Type: application/json\r\n" + b"Content-Length: %i\r\n" + b"\r\n" + b"%s" % (len(res_json), res_json) + ) + + self.pump() + + res = self.successResultOf(test_d) + + # check the response is as expected + self.assertEqual(res, {"a": 1}) + def test_dns_error(self): """ If the DNS lookup returns an error, it will bubble up. @@ -54,6 +128,28 @@ def test_dns_error(self): self.assertIsInstance(f.value, RequestSendFailed) self.assertIsInstance(f.value.inner_exception, DNSLookupError) + def test_client_connection_refused(self): + d = self.cl.get_json("testserv:8008", "foo/bar", timeout=10000) + + self.pump() + + # Nothing happened yet + self.assertNoResult(d) + + clients = self.reactor.tcpClients + self.assertEqual(len(clients), 1) + (host, port, factory, _timeout, _bindAddress) = clients[0] + self.assertEqual(host, '1.2.3.4') + self.assertEqual(port, 8008) + e = Exception("go away") + factory.clientConnectionFailed(None, e) + self.pump(0.5) + + f = self.failureResultOf(d) + + self.assertIsInstance(f.value, RequestSendFailed) + self.assertIs(f.value.inner_exception, e) + def test_client_never_connect(self): """ If the HTTP request is not connected and is timed out, it'll give a From fe212bbe4a6774e34b0a474e1d3c6aee4ae4e3c4 Mon Sep 17 00:00:00 2001 From: Richard van der Hoff Date: Mon, 21 Jan 2019 23:42:22 +0000 Subject: [PATCH 3/8] Kill off matrix_federation_endpoint this thing is now redundant. --- synapse/http/endpoint.py | 144 ------------------------ synapse/http/federation/srv_resolver.py | 1 - 2 files changed, 145 deletions(-) diff --git a/synapse/http/endpoint.py b/synapse/http/endpoint.py index 815f8ff2f72c..cd79ebab6225 100644 --- a/synapse/http/endpoint.py +++ b/synapse/http/endpoint.py @@ -13,15 +13,8 @@ # See the License for the specific language governing permissions and # limitations under the License. import logging -import random import re -from twisted.internet import defer -from twisted.internet.endpoints import HostnameEndpoint, wrapClientTLS -from twisted.internet.error import ConnectError - -from synapse.http.federation.srv_resolver import Server, resolve_service - logger = logging.getLogger(__name__) @@ -88,140 +81,3 @@ def parse_and_validate_server_name(server_name): )) return host, port - - -def matrix_federation_endpoint(reactor, destination, tls_client_options_factory=None, - timeout=None): - """Construct an endpoint for the given matrix destination. - - Args: - reactor: Twisted reactor. - destination (unicode): The name of the server to connect to. - tls_client_options_factory - (synapse.crypto.context_factory.ClientTLSOptionsFactory): - Factory which generates TLS options for client connections. - timeout (int): connection timeout in seconds - """ - - domain, port = parse_server_name(destination) - - endpoint_kw_args = {} - - if timeout is not None: - endpoint_kw_args.update(timeout=timeout) - - if tls_client_options_factory is None: - transport_endpoint = HostnameEndpoint - default_port = 8008 - else: - # the SNI string should be the same as the Host header, minus the port. - # as per https://github.com/matrix-org/synapse/issues/2525#issuecomment-336896777, - # the Host header and SNI should therefore be the server_name of the remote - # server. - tls_options = tls_client_options_factory.get_options(domain) - - def transport_endpoint(reactor, host, port, timeout): - return wrapClientTLS( - tls_options, - HostnameEndpoint(reactor, host, port, timeout=timeout), - ) - default_port = 8448 - - if port is None: - return SRVClientEndpoint( - reactor, "matrix", domain, protocol="tcp", - default_port=default_port, endpoint=transport_endpoint, - endpoint_kw_args=endpoint_kw_args - ) - else: - return transport_endpoint( - reactor, domain, port, **endpoint_kw_args - ) - - -class SRVClientEndpoint(object): - """An endpoint which looks up SRV records for a service. - Cycles through the list of servers starting with each call to connect - picking the next server. - Implements twisted.internet.interfaces.IStreamClientEndpoint. - """ - - def __init__(self, reactor, service, domain, protocol="tcp", - default_port=None, endpoint=HostnameEndpoint, - endpoint_kw_args={}): - self.reactor = reactor - self.service_name = "_%s._%s.%s" % (service, protocol, domain) - - if default_port is not None: - self.default_server = Server( - host=domain, - port=default_port, - ) - else: - self.default_server = None - - self.endpoint = endpoint - self.endpoint_kw_args = endpoint_kw_args - - self.servers = None - self.used_servers = None - - @defer.inlineCallbacks - def fetch_servers(self): - self.used_servers = [] - self.servers = yield resolve_service(self.service_name) - - def pick_server(self): - if not self.servers: - if self.used_servers: - self.servers = self.used_servers - self.used_servers = [] - self.servers.sort() - elif self.default_server: - return self.default_server - else: - raise ConnectError( - "No server available for %s" % self.service_name - ) - - # look for all servers with the same priority - min_priority = self.servers[0].priority - weight_indexes = list( - (index, server.weight + 1) - for index, server in enumerate(self.servers) - if server.priority == min_priority - ) - - total_weight = sum(weight for index, weight in weight_indexes) - target_weight = random.randint(0, total_weight) - for index, weight in weight_indexes: - target_weight -= weight - if target_weight <= 0: - server = self.servers[index] - # XXX: this looks totally dubious: - # - # (a) we never reuse a server until we have been through - # all of the servers at the same priority, so if the - # weights are A: 100, B:1, we always do ABABAB instead of - # AAAA...AAAB (approximately). - # - # (b) After using all the servers at the lowest priority, - # we move onto the next priority. We should only use the - # second priority if servers at the top priority are - # unreachable. - # - del self.servers[index] - self.used_servers.append(server) - return server - - @defer.inlineCallbacks - def connect(self, protocolFactory): - if self.servers is None: - yield self.fetch_servers() - server = self.pick_server() - logger.info("Connecting to %s:%s", server.host, server.port) - endpoint = self.endpoint( - self.reactor, server.host, server.port, **self.endpoint_kw_args - ) - connection = yield endpoint.connect(protocolFactory) - defer.returnValue(connection) diff --git a/synapse/http/federation/srv_resolver.py b/synapse/http/federation/srv_resolver.py index ded0b32832b8..a6e92fdf40c5 100644 --- a/synapse/http/federation/srv_resolver.py +++ b/synapse/http/federation/srv_resolver.py @@ -152,6 +152,5 @@ def resolve_service(service_name, dns_client=client, cache=SERVER_CACHE, clock=t expires=int(clock.time()) + answer.ttl, )) - servers.sort() # FIXME: get rid of this (it's broken by the attrs change) cache[service_name] = list(servers) defer.returnValue(servers) From c66f4bf7f134bb016343542f53f4f40f8ab9b803 Mon Sep 17 00:00:00 2001 From: Richard van der Hoff Date: Mon, 21 Jan 2019 23:54:22 +0000 Subject: [PATCH 4/8] changelog --- changelog.d/4428.misc | 1 + 1 file changed, 1 insertion(+) create mode 100644 changelog.d/4428.misc diff --git a/changelog.d/4428.misc b/changelog.d/4428.misc new file mode 100644 index 000000000000..9a51434755cb --- /dev/null +++ b/changelog.d/4428.misc @@ -0,0 +1 @@ +Move SRV logic into the Agent layer From 53a327b4d5bdcab36651aa86ddf1815ff86e5db2 Mon Sep 17 00:00:00 2001 From: Richard van der Hoff Date: Tue, 22 Jan 2019 17:35:09 +0000 Subject: [PATCH 5/8] Require that service_name be a byte string it is only ever a bytes now, so let's enforce that. --- synapse/http/federation/srv_resolver.py | 8 ++++---- tests/http/federation/test_srv_resolver.py | 8 ++++---- 2 files changed, 8 insertions(+), 8 deletions(-) diff --git a/synapse/http/federation/srv_resolver.py b/synapse/http/federation/srv_resolver.py index a6e92fdf40c5..e05f934d0b77 100644 --- a/synapse/http/federation/srv_resolver.py +++ b/synapse/http/federation/srv_resolver.py @@ -92,7 +92,7 @@ def resolve_service(service_name, dns_client=client, cache=SERVER_CACHE, clock=t but the cache never gets populated), so we add our own caching layer here. Args: - service_name (unicode|bytes): record to look up + service_name (bytes): record to look up dns_client (twisted.internet.interfaces.IResolver): twisted resolver impl cache (dict): cache object clock (object): clock implementation. must provide a time() method. @@ -100,9 +100,9 @@ def resolve_service(service_name, dns_client=client, cache=SERVER_CACHE, clock=t Returns: Deferred[list[Server]]: a list of the SRV records, or an empty list if none found """ - # TODO: the dns client handles both unicode names (encoding via idna) and pre-encoded - # byteses; however they will obviously end up as separate entries in the cache. We - # should pick one form and stick with it. + if not isinstance(service_name, bytes): + raise TypeError("%r is not a byte string" % (service_name,)) + cache_entry = cache.get(service_name, None) if cache_entry: if all(s.expires > int(clock.time()) for s in cache_entry): diff --git a/tests/http/federation/test_srv_resolver.py b/tests/http/federation/test_srv_resolver.py index 1271a495e187..de4d0089c8cb 100644 --- a/tests/http/federation/test_srv_resolver.py +++ b/tests/http/federation/test_srv_resolver.py @@ -83,7 +83,7 @@ def test_from_cache_expired_and_dns_fail(self): dns_client_mock = Mock() dns_client_mock.lookupService.return_value = defer.fail(error.DNSServerError()) - service_name = "test_service.example.com" + service_name = b"test_service.example.com" entry = Mock(spec_set=["expires"]) entry.expires = 0 @@ -106,7 +106,7 @@ def test_from_cache(self): dns_client_mock = Mock(spec_set=['lookupService']) dns_client_mock.lookupService = Mock(spec_set=[]) - service_name = "test_service.example.com" + service_name = b"test_service.example.com" entry = Mock(spec_set=["expires"]) entry.expires = 999999999 @@ -128,7 +128,7 @@ def test_empty_cache(self): dns_client_mock.lookupService.return_value = defer.fail(error.DNSServerError()) - service_name = "test_service.example.com" + service_name = b"test_service.example.com" cache = {} @@ -141,7 +141,7 @@ def test_name_error(self): dns_client_mock.lookupService.return_value = defer.fail(error.DNSNameError()) - service_name = "test_service.example.com" + service_name = b"test_service.example.com" cache = {} From 7021784d4612c328ef174963c6d5ca9a37d24bc7 Mon Sep 17 00:00:00 2001 From: Richard van der Hoff Date: Tue, 22 Jan 2019 17:42:26 +0000 Subject: [PATCH 6/8] put resolve_service in an object this makes it easier to stub things out for tests. --- .../federation/matrix_federation_agent.py | 16 ++- synapse/http/federation/srv_resolver.py | 133 ++++++++++-------- tests/http/federation/test_srv_resolver.py | 38 +++-- 3 files changed, 104 insertions(+), 83 deletions(-) diff --git a/synapse/http/federation/matrix_federation_agent.py b/synapse/http/federation/matrix_federation_agent.py index 32bfd68ed168..64c780a3410e 100644 --- a/synapse/http/federation/matrix_federation_agent.py +++ b/synapse/http/federation/matrix_federation_agent.py @@ -22,7 +22,7 @@ from twisted.web.iweb import IAgent from synapse.http.endpoint import parse_server_name -from synapse.http.federation.srv_resolver import pick_server_from_list, resolve_service +from synapse.http.federation.srv_resolver import SrvResolver, pick_server_from_list from synapse.util.logcontext import make_deferred_yieldable logger = logging.getLogger(__name__) @@ -37,13 +37,23 @@ class MatrixFederationAgent(object): Args: reactor (IReactor): twisted reactor to use for underlying requests + tls_client_options_factory (ClientTLSOptionsFactory|None): factory to use for fetching client tls options, or none to disable TLS. + + srv_resolver (SrvResolver|None): + SRVResolver impl to use for looking up SRV records. None to use a default + implementation. """ - def __init__(self, reactor, tls_client_options_factory): + def __init__( + self, reactor, tls_client_options_factory, _srv_resolver=None, + ): self._reactor = reactor self._tls_client_options_factory = tls_client_options_factory + if _srv_resolver is None: + _srv_resolver = SrvResolver() + self._srv_resolver = _srv_resolver self._pool = HTTPConnectionPool(reactor) self._pool.retryAutomatically = False @@ -91,7 +101,7 @@ def request(self, method, uri, headers=None, bodyProducer=None): if port is not None: target = (host, port) else: - server_list = yield resolve_service(server_name_bytes) + server_list = yield self._srv_resolver.resolve_service(server_name_bytes) if not server_list: target = (host, 8448) logger.debug("No SRV record for %s, using %s", host, target) diff --git a/synapse/http/federation/srv_resolver.py b/synapse/http/federation/srv_resolver.py index e05f934d0b77..71830c549d4b 100644 --- a/synapse/http/federation/srv_resolver.py +++ b/synapse/http/federation/srv_resolver.py @@ -84,73 +84,86 @@ def pick_server_from_list(server_list): ) -@defer.inlineCallbacks -def resolve_service(service_name, dns_client=client, cache=SERVER_CACHE, clock=time): - """Look up a SRV record, with caching +class SrvResolver(object): + """Interface to the dns client to do SRV lookups, with result caching. The default resolver in twisted.names doesn't do any caching (it has a CacheResolver, but the cache never gets populated), so we add our own caching layer here. Args: - service_name (bytes): record to look up dns_client (twisted.internet.interfaces.IResolver): twisted resolver impl cache (dict): cache object - clock (object): clock implementation. must provide a time() method. - - Returns: - Deferred[list[Server]]: a list of the SRV records, or an empty list if none found + get_time (callable): clock implementation. Should return seconds since the epoch """ - if not isinstance(service_name, bytes): - raise TypeError("%r is not a byte string" % (service_name,)) - - cache_entry = cache.get(service_name, None) - if cache_entry: - if all(s.expires > int(clock.time()) for s in cache_entry): - servers = list(cache_entry) - defer.returnValue(servers) - - try: - answers, _, _ = yield make_deferred_yieldable( - dns_client.lookupService(service_name), - ) - except DNSNameError: - # TODO: cache this. We can get the SOA out of the exception, and use - # the negative-TTL value. - defer.returnValue([]) - except DomainError as e: - # We failed to resolve the name (other than a NameError) - # Try something in the cache, else rereaise - cache_entry = cache.get(service_name, None) + def __init__(self, dns_client=client, cache=SERVER_CACHE, get_time=time.time): + self._dns_client = dns_client + self._cache = cache + self._get_time = get_time + + @defer.inlineCallbacks + def resolve_service(self, service_name): + """Look up a SRV record + + Args: + service_name (bytes): record to look up + + Returns: + Deferred[list[Server]]: + a list of the SRV records, or an empty list if none found + """ + now = int(self._get_time()) + + if not isinstance(service_name, bytes): + raise TypeError("%r is not a byte string" % (service_name,)) + + cache_entry = self._cache.get(service_name, None) if cache_entry: - logger.warn( - "Failed to resolve %r, falling back to cache. %r", - service_name, e + if all(s.expires > now for s in cache_entry): + servers = list(cache_entry) + defer.returnValue(servers) + + try: + answers, _, _ = yield make_deferred_yieldable( + self._dns_client.lookupService(service_name), ) - defer.returnValue(list(cache_entry)) - else: - raise e - - if (len(answers) == 1 - and answers[0].type == dns.SRV - and answers[0].payload - and answers[0].payload.target == dns.Name(b'.')): - raise ConnectError("Service %s unavailable" % service_name) - - servers = [] - - for answer in answers: - if answer.type != dns.SRV or not answer.payload: - continue - - payload = answer.payload - - servers.append(Server( - host=payload.target.name, - port=payload.port, - priority=payload.priority, - weight=payload.weight, - expires=int(clock.time()) + answer.ttl, - )) - - cache[service_name] = list(servers) - defer.returnValue(servers) + except DNSNameError: + # TODO: cache this. We can get the SOA out of the exception, and use + # the negative-TTL value. + defer.returnValue([]) + except DomainError as e: + # We failed to resolve the name (other than a NameError) + # Try something in the cache, else rereaise + cache_entry = self._cache.get(service_name, None) + if cache_entry: + logger.warn( + "Failed to resolve %r, falling back to cache. %r", + service_name, e + ) + defer.returnValue(list(cache_entry)) + else: + raise e + + if (len(answers) == 1 + and answers[0].type == dns.SRV + and answers[0].payload + and answers[0].payload.target == dns.Name(b'.')): + raise ConnectError("Service %s unavailable" % service_name) + + servers = [] + + for answer in answers: + if answer.type != dns.SRV or not answer.payload: + continue + + payload = answer.payload + + servers.append(Server( + host=payload.target.name, + port=payload.port, + priority=payload.priority, + weight=payload.weight, + expires=now + answer.ttl, + )) + + self._cache[service_name] = list(servers) + defer.returnValue(servers) diff --git a/tests/http/federation/test_srv_resolver.py b/tests/http/federation/test_srv_resolver.py index de4d0089c8cb..a872e2441e79 100644 --- a/tests/http/federation/test_srv_resolver.py +++ b/tests/http/federation/test_srv_resolver.py @@ -21,7 +21,7 @@ from twisted.internet.error import ConnectError from twisted.names import dns, error -from synapse.http.federation.srv_resolver import resolve_service +from synapse.http.federation.srv_resolver import SrvResolver from synapse.util.logcontext import LoggingContext from tests import unittest @@ -43,13 +43,13 @@ def test_resolve(self): dns_client_mock.lookupService.return_value = result_deferred cache = {} + resolver = SrvResolver(dns_client=dns_client_mock, cache=cache) @defer.inlineCallbacks def do_lookup(): + with LoggingContext("one") as ctx: - resolve_d = resolve_service( - service_name, dns_client=dns_client_mock, cache=cache - ) + resolve_d = resolver.resolve_service(service_name) self.assertNoResult(resolve_d) @@ -89,10 +89,9 @@ def test_from_cache_expired_and_dns_fail(self): entry.expires = 0 cache = {service_name: [entry]} + resolver = SrvResolver(dns_client=dns_client_mock, cache=cache) - servers = yield resolve_service( - service_name, dns_client=dns_client_mock, cache=cache - ) + servers = yield resolver.resolve_service(service_name) dns_client_mock.lookupService.assert_called_once_with(service_name) @@ -112,11 +111,12 @@ def test_from_cache(self): entry.expires = 999999999 cache = {service_name: [entry]} - - servers = yield resolve_service( - service_name, dns_client=dns_client_mock, cache=cache, clock=clock + resolver = SrvResolver( + dns_client=dns_client_mock, cache=cache, get_time=clock.time, ) + servers = yield resolver.resolve_service(service_name) + self.assertFalse(dns_client_mock.lookupService.called) self.assertEquals(len(servers), 1) @@ -131,9 +131,10 @@ def test_empty_cache(self): service_name = b"test_service.example.com" cache = {} + resolver = SrvResolver(dns_client=dns_client_mock, cache=cache) with self.assertRaises(error.DNSServerError): - yield resolve_service(service_name, dns_client=dns_client_mock, cache=cache) + yield resolver.resolve_service(service_name) @defer.inlineCallbacks def test_name_error(self): @@ -144,10 +145,9 @@ def test_name_error(self): service_name = b"test_service.example.com" cache = {} + resolver = SrvResolver(dns_client=dns_client_mock, cache=cache) - servers = yield resolve_service( - service_name, dns_client=dns_client_mock, cache=cache - ) + servers = yield resolver.resolve_service(service_name) self.assertEquals(len(servers), 0) self.assertEquals(len(cache), 0) @@ -162,10 +162,9 @@ def test_disabled_service(self): dns_client_mock = Mock() dns_client_mock.lookupService.return_value = lookup_deferred cache = {} + resolver = SrvResolver(dns_client=dns_client_mock, cache=cache) - resolve_d = resolve_service( - service_name, dns_client=dns_client_mock, cache=cache - ) + resolve_d = resolver.resolve_service(service_name) self.assertNoResult(resolve_d) # returning a single "." should make the lookup fail with a ConenctError @@ -187,10 +186,9 @@ def test_non_srv_answer(self): dns_client_mock = Mock() dns_client_mock.lookupService.return_value = lookup_deferred cache = {} + resolver = SrvResolver(dns_client=dns_client_mock, cache=cache) - resolve_d = resolve_service( - service_name, dns_client=dns_client_mock, cache=cache - ) + resolve_d = resolver.resolve_service(service_name) self.assertNoResult(resolve_d) lookup_deferred.callback(( From d02c4532c068efc54c6abce77e9ec55018b2d444 Mon Sep 17 00:00:00 2001 From: Richard van der Hoff Date: Tue, 22 Jan 2019 20:28:48 +0000 Subject: [PATCH 7/8] Add a test for MatrixFederationAgent --- .../test_matrix_federation_agent.py | 183 ++++++++++++++++++ tests/server.py | 13 +- 2 files changed, 195 insertions(+), 1 deletion(-) create mode 100644 tests/http/federation/test_matrix_federation_agent.py diff --git a/tests/http/federation/test_matrix_federation_agent.py b/tests/http/federation/test_matrix_federation_agent.py new file mode 100644 index 000000000000..eb963d80fb5c --- /dev/null +++ b/tests/http/federation/test_matrix_federation_agent.py @@ -0,0 +1,183 @@ +# -*- coding: utf-8 -*- +# Copyright 2019 New Vector Ltd +# +# Licensed under the Apache License, Version 2.0 (the "License"); +# you may not use this file except in compliance with the License. +# You may obtain a copy of the License at +# +# http://www.apache.org/licenses/LICENSE-2.0 +# +# Unless required by applicable law or agreed to in writing, software +# distributed under the License is distributed on an "AS IS" BASIS, +# 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 logging + +from mock import Mock + +import treq + +from twisted.internet import defer +from twisted.internet.protocol import Factory +from twisted.protocols.tls import TLSMemoryBIOFactory +from twisted.test.ssl_helpers import ServerTLSContext +from twisted.web.http import HTTPChannel + +from synapse.crypto.context_factory import ClientTLSOptionsFactory +from synapse.http.federation.matrix_federation_agent import MatrixFederationAgent +from synapse.util.logcontext import LoggingContext + +from tests.server import FakeTransport, ThreadedMemoryReactorClock +from tests.unittest import TestCase + +logger = logging.getLogger(__name__) + + +class MatrixFederationAgentTests(TestCase): + def setUp(self): + self.reactor = ThreadedMemoryReactorClock() + + self.mock_resolver = Mock() + + self.agent = MatrixFederationAgent( + reactor=self.reactor, + tls_client_options_factory=ClientTLSOptionsFactory(None), + _srv_resolver=self.mock_resolver, + ) + + def _make_connection(self, client_factory): + """Builds a test server, and completes the outgoing client connection + + Returns: + HTTPChannel: the test server + """ + + # build the test server + server_tls_protocol = _build_test_server() + + # now, tell the client protocol factory to build the client protocol (it will be a + # _WrappingProtocol, around a TLSMemoryBIOProtocol, around an + # HTTP11ClientProtocol) and wire the output of said protocol up to the server via + # a FakeTransport. + # + # Normally this would be done by the TCP socket code in Twisted, but we are + # stubbing that out here. + client_protocol = client_factory.buildProtocol(None) + client_protocol.makeConnection(FakeTransport(server_tls_protocol, self.reactor)) + + # tell the server tls protocol to send its stuff back to the client, too + server_tls_protocol.makeConnection(FakeTransport(client_protocol, self.reactor)) + + # finally, give the reactor a pump to get the TLS juices flowing. + self.reactor.pump((0.1,)) + + # fish the test server back out of the server-side TLS protocol. + return server_tls_protocol.wrappedProtocol + + @defer.inlineCallbacks + def _make_get_request(self, uri): + """ + Sends a simple GET request via the agent, and checks its logcontext management + """ + with LoggingContext("one") as context: + fetch_d = self.agent.request(b'GET', uri) + + # Nothing happened yet + self.assertNoResult(fetch_d) + + # should have reset logcontext to the sentinel + _check_logcontext(LoggingContext.sentinel) + + try: + fetch_res = yield fetch_d + defer.returnValue(fetch_res) + finally: + _check_logcontext(context) + + def test_get(self): + """ + happy-path test of a GET request + """ + self.reactor.lookups["testserv"] = "1.2.3.4" + test_d = self._make_get_request(b"matrix://testserv:8448/foo/bar") + + # Nothing happened yet + self.assertNoResult(test_d) + + # Make sure treq is trying to connect + clients = self.reactor.tcpClients + self.assertEqual(len(clients), 1) + (host, port, client_factory, _timeout, _bindAddress) = clients[0] + self.assertEqual(host, '1.2.3.4') + self.assertEqual(port, 8448) + + # make a test server, and wire up the client + http_server = self._make_connection(client_factory) + + self.assertEqual(len(http_server.requests), 1) + request = http_server.requests[0] + self.assertEqual(request.method, b'GET') + self.assertEqual(request.path, b'/foo/bar') + self.assertEqual( + request.requestHeaders.getRawHeaders(b'host'), + [b'testserv:8448'] + ) + content = request.content.read() + self.assertEqual(content, b'') + + # Deferred is still without a result + self.assertNoResult(test_d) + + # send the headers + request.responseHeaders.setRawHeaders(b'Content-Type', [b'application/json']) + request.write('') + + self.reactor.pump((0.1,)) + + response = self.successResultOf(test_d) + + # that should give us a Response object + self.assertEqual(response.code, 200) + + # Send the body + request.write('{ "a": 1 }'.encode('ascii')) + request.finish() + + self.reactor.pump((0.1,)) + + # check it can be read + json = self.successResultOf(treq.json_content(response)) + self.assertEqual(json, {"a": 1}) + + +def _check_logcontext(context): + current = LoggingContext.current_context() + if current is not context: + raise AssertionError( + "Expected logcontext %s but was %s" % (context, current), + ) + + +def _build_test_server(): + """Construct a test server + + This builds an HTTP channel, wrapped with a TLSMemoryBIOProtocol + + Returns: + TLSMemoryBIOProtocol + """ + server_factory = Factory.forProtocol(HTTPChannel) + # Request.finish expects the factory to have a 'log' method. + server_factory.log = _log_request + + server_tls_factory = TLSMemoryBIOFactory( + ServerTLSContext(), isClient=False, wrappedFactory=server_factory, + ) + + return server_tls_factory.buildProtocol(None) + + +def _log_request(request): + """Implements Factory.log, which is expected by Request.finish""" + logger.info("Completed request %s", request) diff --git a/tests/server.py b/tests/server.py index db43fa0db8df..3a4aa55645fd 100644 --- a/tests/server.py +++ b/tests/server.py @@ -1,4 +1,5 @@ import json +import logging from io import BytesIO from six import text_type @@ -22,6 +23,8 @@ from tests.utils import setup_test_homeserver as _sth +logger = logging.getLogger(__name__) + class TimedOutException(Exception): """ @@ -414,6 +417,11 @@ def write(self, byt): self.buffer = self.buffer + byt def _write(): + if not self.buffer: + # nothing to do. Don't write empty buffers: it upsets the + # TLSMemoryBIOProtocol + return + if getattr(self.other, "transport") is not None: self.other.dataReceived(self.buffer) self.buffer = b"" @@ -421,7 +429,10 @@ def _write(): self._reactor.callLater(0.0, _write) - _write() + # always actually do the write asynchronously. Some protocols (notably the + # TLSMemoryBIOProtocol) get very confused if a read comes back while they are + # still doing a write. Doing a callLater here breaks the cycle. + self._reactor.callLater(0.0, _write) def writeSequence(self, seq): for x in seq: From 6b574f3df7ec9ff2b92e85b34f055b50cd318930 Mon Sep 17 00:00:00 2001 From: Richard van der Hoff Date: Wed, 23 Jan 2019 11:25:36 +0000 Subject: [PATCH 8/8] fix python2 test failure --- tests/server.py | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/tests/server.py b/tests/server.py index 3a4aa55645fd..ed2a046ae679 100644 --- a/tests/server.py +++ b/tests/server.py @@ -342,7 +342,7 @@ def get_clock(): return (clock, hs_clock) -@attr.s +@attr.s(cmp=False) class FakeTransport(object): """ A twisted.internet.interfaces.ITransport implementation which sends all its data