diff options
Diffstat (limited to 'synapse/http/federation/matrix_federation_agent.py')
| -rw-r--r-- | synapse/http/federation/matrix_federation_agent.py | 107 |
1 files changed, 103 insertions, 4 deletions
diff --git a/synapse/http/federation/matrix_federation_agent.py b/synapse/http/federation/matrix_federation_agent.py index 4a6f634c8b..f81fcd4301 100644 --- a/synapse/http/federation/matrix_federation_agent.py +++ b/synapse/http/federation/matrix_federation_agent.py @@ -12,6 +12,7 @@ # 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 json import logging import attr @@ -20,7 +21,7 @@ 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.client import URI, Agent, HTTPConnectionPool, readBody from twisted.web.http_headers import Headers from twisted.web.iweb import IAgent @@ -43,13 +44,19 @@ class MatrixFederationAgent(object): tls_client_options_factory (ClientTLSOptionsFactory|None): factory to use for fetching client tls options, or none to disable TLS. + _well_known_tls_policy (IPolicyForHTTPS|None): + TLS policy to use for fetching .well-known files. None to use a default + (browser-like) implementation. + 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, _srv_resolver=None, + self, reactor, tls_client_options_factory, + _well_known_tls_policy=None, + _srv_resolver=None, ): self._reactor = reactor self._tls_client_options_factory = tls_client_options_factory @@ -62,6 +69,14 @@ class MatrixFederationAgent(object): self._pool.maxPersistentPerHost = 5 self._pool.cachedConnectionTimeout = 2 * 60 + agent_args = {} + if _well_known_tls_policy is not None: + # the param is called 'contextFactory', but actually passing a + # contextfactory is deprecated, and it expects an IPolicyForHTTPS. + agent_args['contextFactory'] = _well_known_tls_policy + _well_known_agent = Agent(self._reactor, pool=self._pool, **agent_args) + self._well_known_agent = _well_known_agent + @defer.inlineCallbacks def request(self, method, uri, headers=None, bodyProducer=None): """ @@ -114,7 +129,11 @@ class MatrixFederationAgent(object): class EndpointFactory(object): @staticmethod def endpointForURI(_uri): - logger.info("Connecting to %s:%s", res.target_host, res.target_port) + logger.info( + "Connecting to %s:%i", + res.target_host.decode("ascii"), + res.target_port, + ) ep = HostnameEndpoint(self._reactor, res.target_host, res.target_port) if tls_options is not None: ep = wrapClientTLS(tls_options, ep) @@ -127,7 +146,7 @@ class MatrixFederationAgent(object): defer.returnValue(res) @defer.inlineCallbacks - def _route_matrix_uri(self, parsed_uri): + def _route_matrix_uri(self, parsed_uri, lookup_well_known=True): """Helper for `request`: determine the routing for a Matrix URI Args: @@ -135,6 +154,9 @@ class MatrixFederationAgent(object): parsed with URI.fromBytes(uri, defaultPort=-1) to set the `port` to -1 if there is no explicit port given. + lookup_well_known (bool): True if we should look up the .well-known file if + there is no SRV record. + Returns: Deferred[_RoutingResult] """ @@ -169,6 +191,42 @@ class MatrixFederationAgent(object): service_name = b"_matrix._tcp.%s" % (parsed_uri.host,) server_list = yield self._srv_resolver.resolve_service(service_name) + if not server_list and lookup_well_known: + # try a .well-known lookup + well_known_server = yield self._get_well_known(parsed_uri.host) + + if well_known_server: + # if we found a .well-known, start again, but don't do another + # .well-known lookup. + + # parse the server name in the .well-known response into host/port. + # (This code is lifted from twisted.web.client.URI.fromBytes). + if b':' in well_known_server: + well_known_host, well_known_port = well_known_server.rsplit(b':', 1) + try: + well_known_port = int(well_known_port) + except ValueError: + # the part after the colon could not be parsed as an int + # - we assume it is an IPv6 literal with no port (the closing + # ']' stops it being parsed as an int) + well_known_host, well_known_port = well_known_server, -1 + else: + well_known_host, well_known_port = well_known_server, -1 + + new_uri = URI( + scheme=parsed_uri.scheme, + netloc=well_known_server, + host=well_known_host, + port=well_known_port, + path=parsed_uri.path, + params=parsed_uri.params, + query=parsed_uri.query, + fragment=parsed_uri.fragment, + ) + + res = yield self._route_matrix_uri(new_uri, lookup_well_known=False) + defer.returnValue(res) + if not server_list: target_host = parsed_uri.host port = 8448 @@ -190,6 +248,47 @@ class MatrixFederationAgent(object): target_port=port, )) + @defer.inlineCallbacks + def _get_well_known(self, server_name): + """Attempt to fetch and parse a .well-known file for the given server + + Args: + server_name (bytes): name of the server, from the requested url + + Returns: + Deferred[bytes|None]: either the new server name, from the .well-known, or + None if there was no .well-known file. + """ + # FIXME: add a cache + + uri = b"https://%s/.well-known/matrix/server" % (server_name, ) + uri_str = uri.decode("ascii") + logger.info("Fetching %s", uri_str) + try: + response = yield make_deferred_yieldable( + self._well_known_agent.request(b"GET", uri), + ) + except Exception as e: + logger.info("Connection error fetching %s: %s", uri_str, e) + defer.returnValue(None) + + body = yield make_deferred_yieldable(readBody(response)) + + if response.code != 200: + logger.info("Error response %i from %s", response.code, uri_str) + defer.returnValue(None) + + try: + parsed_body = json.loads(body.decode('utf-8')) + logger.info("Response from .well-known: %s", parsed_body) + if not isinstance(parsed_body, dict): + raise Exception("not a dict") + if "m.server" not in parsed_body: + raise Exception("Missing key 'm.server'") + except Exception as e: + raise Exception("invalid .well-known response from %s: %s" % (uri_str, e,)) + defer.returnValue(parsed_body["m.server"].encode("ascii")) + @attr.s class _RoutingResult(object): |