From 4903ccf159552319a36708069c8eb52ce53542dd Mon Sep 17 00:00:00 2001 From: Richard van der Hoff Date: Fri, 21 Apr 2017 00:46:54 +0100 Subject: [PATCH 1/5] Fix some lies, and other clarifications, in docstrings The documentation on get_json has been wrong ever since the very first commit to synapse... --- contrib/cmdclient/http.py | 16 +++----- synapse/federation/federation_client.py | 50 ++++++++++++++++++++++++- synapse/federation/transport/client.py | 20 ++++++++++ synapse/http/matrixfederationclient.py | 21 +++++++---- 4 files changed, 88 insertions(+), 19 deletions(-) diff --git a/contrib/cmdclient/http.py b/contrib/cmdclient/http.py index 418689731..c833f3f31 100644 --- a/contrib/cmdclient/http.py +++ b/contrib/cmdclient/http.py @@ -36,15 +36,13 @@ class HttpClient(object): the request body. This will be encoded as JSON. Returns: - Deferred: Succeeds when we get *any* HTTP response. - - The result of the deferred is a tuple of `(code, response)`, - where `response` is a dict representing the decoded JSON body. + Deferred: Succeeds when we get a 2xx HTTP response. The result + will be the decoded JSON body. """ pass def get_json(self, url, args=None): - """ Get's some json from the given host homeserver and path + """ Gets some json from the given host homeserver and path Args: url (str): The URL to GET data from. @@ -54,10 +52,8 @@ class HttpClient(object): and *not* a string. Returns: - Deferred: Succeeds when we get *any* HTTP response. - - The result of the deferred is a tuple of `(code, response)`, - where `response` is a dict representing the decoded JSON body. + Deferred: Succeeds when we get a 2xx HTTP response. The result + will be the decoded JSON body. """ pass @@ -214,4 +210,4 @@ class _JsonProducer(object): pass def stopProducing(self): - pass \ No newline at end of file + pass diff --git a/synapse/federation/federation_client.py b/synapse/federation/federation_client.py index deee0f490..861441708 100644 --- a/synapse/federation/federation_client.py +++ b/synapse/federation/federation_client.py @@ -474,8 +474,13 @@ class FederationClient(FederationBase): content (object): Any additional data to put into the content field of the event. Return: - A tuple of (origin (str), event (object)) where origin is the remote - homeserver which generated the event. + Deferred: resolves to a tuple of (origin (str), event (object)) + where origin is the remote homeserver which generated the event. + + Fails with a ``CodeMessageException`` if the chosen remote server + returns a 300/400 code. + + Fails with a ``RuntimeError`` if no servers were reachable. """ valid_memberships = {Membership.JOIN, Membership.LEAVE} if membership not in valid_memberships: @@ -528,6 +533,27 @@ class FederationClient(FederationBase): @defer.inlineCallbacks def send_join(self, destinations, pdu): + """Sends a join event to one of a list of homeservers. + + Doing so will cause the remote server to add the event to the graph, + and send the event out to the rest of the federation. + + Args: + destinations (str): Candidate homeservers which are probably + participating in the room. + pdu (BaseEvent): event to be sent + + Return: + Deferred: resolves to a dict with members ``origin`` (a string + giving the serer the event was sent to, ``state`` (?) and + ``auth_chain``. + + Fails with a ``CodeMessageException`` if the chosen remote server + returns a 300/400 code. + + Fails with a ``RuntimeError`` if no servers were reachable. + """ + for destination in destinations: if destination == self.server_name: continue @@ -635,6 +661,26 @@ class FederationClient(FederationBase): @defer.inlineCallbacks def send_leave(self, destinations, pdu): + """Sends a leave event to one of a list of homeservers. + + Doing so will cause the remote server to add the event to the graph, + and send the event out to the rest of the federation. + + This is mostly useful to reject received invites. + + Args: + destinations (str): Candidate homeservers which are probably + participating in the room. + pdu (BaseEvent): event to be sent + + Return: + Deferred: resolves to None. + + Fails with a ``CodeMessageException`` if the chosen remote server + returns a non-200 code. + + Fails with a ``RuntimeError`` if no servers were reachable. + """ for destination in destinations: if destination == self.server_name: continue diff --git a/synapse/federation/transport/client.py b/synapse/federation/transport/client.py index 15a03378f..8887c624d 100644 --- a/synapse/federation/transport/client.py +++ b/synapse/federation/transport/client.py @@ -193,6 +193,26 @@ class TransportLayerClient(object): @defer.inlineCallbacks @log_function def make_membership_event(self, destination, room_id, user_id, membership): + """Asks a remote server to build and sign us a membership event + + Note that this does not append any events to any graphs. + + Args: + destination (str): address of remote homeserver + room_id (str): room to join/leave + user_id (str): user to be joined/left + membership (str): one of join/leave + + Returns: + Deferred: Succeeds when we get a 2xx HTTP response. The result + will be the decoded JSON body (ie, the new event). + + Fails with ``HTTPRequestException`` if we get an HTTP response + code >= 300. + + Fails with ``NotRetryingDestination`` if we are not yet ready + to retry this server. + """ valid_memberships = {Membership.JOIN, Membership.LEAVE} if membership not in valid_memberships: raise RuntimeError( diff --git a/synapse/http/matrixfederationclient.py b/synapse/http/matrixfederationclient.py index 62b4d7e93..747a791f8 100644 --- a/synapse/http/matrixfederationclient.py +++ b/synapse/http/matrixfederationclient.py @@ -125,6 +125,8 @@ class MatrixFederationHttpClient(object): code >= 300. Fails with ``NotRetryingDestination`` if we are not yet ready to retry this server. + (May also fail with plenty of other Exceptions for things like DNS + failures, connection failures, SSL failures.) """ limiter = yield synapse.util.retryutils.get_retry_limiter( destination, @@ -302,8 +304,10 @@ class MatrixFederationHttpClient(object): Returns: Deferred: Succeeds when we get a 2xx HTTP response. The result - will be the decoded JSON body. On a 4xx or 5xx error response a - CodeMessageException is raised. + will be the decoded JSON body. + + Fails with ``HTTPRequestException`` if we get an HTTP response + code >= 300. Fails with ``NotRetryingDestination`` if we are not yet ready to retry this server. @@ -360,8 +364,10 @@ class MatrixFederationHttpClient(object): try the request anyway. Returns: Deferred: Succeeds when we get a 2xx HTTP response. The result - will be the decoded JSON body. On a 4xx or 5xx error response a - CodeMessageException is raised. + will be the decoded JSON body. + + Fails with ``HTTPRequestException`` if we get an HTTP response + code >= 300. Fails with ``NotRetryingDestination`` if we are not yet ready to retry this server. @@ -410,10 +416,11 @@ class MatrixFederationHttpClient(object): ignore_backoff (bool): true to ignore the historical backoff data and try the request anyway. Returns: - Deferred: Succeeds when we get *any* HTTP response. + Deferred: Succeeds when we get a 2xx HTTP response. The result + will be the decoded JSON body. - The result of the deferred is a tuple of `(code, response)`, - where `response` is a dict representing the decoded JSON body. + Fails with ``HTTPRequestException`` if we get an HTTP response + code >= 300. Fails with ``NotRetryingDestination`` if we are not yet ready to retry this server. From 736b9a478478f82ac27a9a6a4899aed66b0b64a8 Mon Sep 17 00:00:00 2001 From: Richard van der Hoff Date: Fri, 21 Apr 2017 00:51:01 +0100 Subject: [PATCH 2/5] Remove redundant function inline `reject_remote_invite`, which only existed to make tracing the callflow more difficult. --- synapse/handlers/room_member.py | 15 +++++---------- 1 file changed, 5 insertions(+), 10 deletions(-) diff --git a/synapse/handlers/room_member.py b/synapse/handlers/room_member.py index 2052d6d05..08fc6d678 100644 --- a/synapse/handlers/room_member.py +++ b/synapse/handlers/room_member.py @@ -139,13 +139,6 @@ class RoomMemberHandler(BaseHandler): ) yield user_joined_room(self.distributor, user, room_id) - def reject_remote_invite(self, user_id, room_id, remote_room_hosts): - return self.hs.get_handlers().federation_handler.do_remotely_reject_invite( - remote_room_hosts, - room_id, - user_id - ) - @defer.inlineCallbacks def update_membership( self, @@ -286,10 +279,12 @@ class RoomMemberHandler(BaseHandler): else: # send the rejection to the inviter's HS. remote_room_hosts = remote_room_hosts + [inviter.domain] - + fed_handler = self.hs.get_handlers().federation_handler try: - ret = yield self.reject_remote_invite( - target.to_string(), room_id, remote_room_hosts + ret = yield fed_handler.do_remotely_reject_invite( + remote_room_hosts, + room_id, + target.to_string(), ) defer.returnValue(ret) except SynapseError as e: From 838810b76af338ecd5d2a34409b4e6ca78daaddb Mon Sep 17 00:00:00 2001 From: Richard van der Hoff Date: Fri, 21 Apr 2017 01:22:07 +0100 Subject: [PATCH 3/5] Broaden the conditions for locally_rejecting invites The logic for marking invites as locally rejected was all well and good, but didn't happen when the remote server returned a 500, or wasn't reachable, or had no DNS, or whatever. Just expand the except clause to catch everything. Fixes https://github.com/matrix-org/synapse/issues/761. --- synapse/handlers/room_member.py | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/synapse/handlers/room_member.py b/synapse/handlers/room_member.py index 08fc6d678..28b2c80a9 100644 --- a/synapse/handlers/room_member.py +++ b/synapse/handlers/room_member.py @@ -287,7 +287,13 @@ class RoomMemberHandler(BaseHandler): target.to_string(), ) defer.returnValue(ret) - except SynapseError as e: + except Exception as e: + # if we were unable to reject the exception, just mark + # it as rejected on our end and plough ahead. + # + # The 'except' clause is very broad, but we need to + # capture everything from DNS failures upwards + # logger.warn("Failed to reject invite: %s", e) yield self.store.locally_reject_invite( From 0cdb32fc43aa2edbdd60fc9f092632a5edf8b348 Mon Sep 17 00:00:00 2001 From: Richard van der Hoff Date: Fri, 21 Apr 2017 01:24:17 +0100 Subject: [PATCH 4/5] Remove redundant try/except clauses The `except SynapseError` clauses were pointless because the wrapped functions would never throw a `SynapseError` (they either throw a `CodeMessageException` or a `RuntimeError`). The `except CodeMessageException` is now also pointless because the caller treats all exceptions equally, so we may as well just throw the `CodeMessageException`. --- synapse/handlers/federation.py | 34 +++++++++++----------------------- 1 file changed, 11 insertions(+), 23 deletions(-) diff --git a/synapse/handlers/federation.py b/synapse/handlers/federation.py index 2d9126dd8..52be5a402 100644 --- a/synapse/handlers/federation.py +++ b/synapse/handlers/federation.py @@ -1090,19 +1090,13 @@ class FederationHandler(BaseHandler): @defer.inlineCallbacks def do_remotely_reject_invite(self, target_hosts, room_id, user_id): - try: - origin, event = yield self._make_and_verify_event( - target_hosts, - room_id, - user_id, - "leave" - ) - event = self._sign_event(event) - except SynapseError: - raise - except CodeMessageException as e: - logger.warn("Failed to reject invite: %s", e) - raise SynapseError(500, "Failed to reject invite") + origin, event = yield self._make_and_verify_event( + target_hosts, + room_id, + user_id, + "leave" + ) + event = self._sign_event(event) # Try the host that we succesfully called /make_leave/ on first for # the /send_leave/ request. @@ -1112,16 +1106,10 @@ class FederationHandler(BaseHandler): except ValueError: pass - try: - yield self.replication_layer.send_leave( - target_hosts, - event - ) - except SynapseError: - raise - except CodeMessageException as e: - logger.warn("Failed to reject invite: %s", e) - raise SynapseError(500, "Failed to reject invite") + yield self.replication_layer.send_leave( + target_hosts, + event + ) context = yield self.state_handler.compute_event_context(event) From 91b39818007e955b15407c3dd9fd2d310d08842b Mon Sep 17 00:00:00 2001 From: Richard van der Hoff Date: Fri, 21 Apr 2017 01:50:36 +0100 Subject: [PATCH 5/5] Try harder when sending leave events When we're rejecting invites, ignore the backoff data, so that we have a better chance of not getting the room out of sync. --- synapse/federation/transport/client.py | 20 +++++++++++++++++++- 1 file changed, 19 insertions(+), 1 deletion(-) diff --git a/synapse/federation/transport/client.py b/synapse/federation/transport/client.py index 8887c624d..52b2a717d 100644 --- a/synapse/federation/transport/client.py +++ b/synapse/federation/transport/client.py @@ -221,11 +221,23 @@ class TransportLayerClient(object): ) path = PREFIX + "/make_%s/%s/%s" % (membership, room_id, user_id) + ignore_backoff = False + retry_on_dns_fail = False + + if membership == Membership.LEAVE: + # we particularly want to do our best to send leave events. The + # problem is that if it fails, we won't retry it later, so if the + # remote server was just having a momentary blip, the room will be + # out of sync. + ignore_backoff = True + retry_on_dns_fail = True + content = yield self.client.get_json( destination=destination, path=path, - retry_on_dns_fail=False, + retry_on_dns_fail=retry_on_dns_fail, timeout=20000, + ignore_backoff=ignore_backoff, ) defer.returnValue(content) @@ -252,6 +264,12 @@ class TransportLayerClient(object): destination=destination, path=path, data=content, + + # we want to do our best to send this through. The problem is + # that if it fails, we won't retry it later, so if the remote + # server was just having a momentary blip, the room will be out of + # sync. + ignore_backoff=True, ) defer.returnValue(response)