diff options
Diffstat (limited to 'synapse/federation')
| -rw-r--r-- | synapse/federation/federation_base.py | 10 | ||||
| -rw-r--r-- | synapse/federation/federation_client.py | 93 | ||||
| -rw-r--r-- | synapse/federation/transport/client.py | 70 |
3 files changed, 157 insertions, 16 deletions
diff --git a/synapse/federation/federation_base.py b/synapse/federation/federation_base.py index 896168c05c..fab6da3c08 100644 --- a/synapse/federation/federation_base.py +++ b/synapse/federation/federation_base.py @@ -47,6 +47,11 @@ class FederationBase: ) -> EventBase: """Checks that event is correctly signed by the sending server. + Also checks the content hash, and redacts the event if there is a mismatch. + + Also runs the event through the spam checker; if it fails, redacts the event + and flags it as soft-failed. + Args: room_version: The room version of the PDU pdu: the event to be checked @@ -55,7 +60,10 @@ class FederationBase: * the original event if the checks pass * a redacted version of the event (if the signature matched but the hash did not) - * throws a SynapseError if the signature check failed.""" + + Raises: + SynapseError if the signature check failed. + """ try: await _check_sigs_on_pdu(self.keyring, room_version, pdu) except SynapseError as e: diff --git a/synapse/federation/federation_client.py b/synapse/federation/federation_client.py index 48c90bf0bb..c2997997da 100644 --- a/synapse/federation/federation_client.py +++ b/synapse/federation/federation_client.py @@ -419,26 +419,90 @@ class FederationClient(FederationBase): return state_event_ids, auth_event_ids + async def get_room_state( + self, + destination: str, + room_id: str, + event_id: str, + room_version: RoomVersion, + ) -> Tuple[List[EventBase], List[EventBase]]: + """Calls the /state endpoint to fetch the state at a particular point + in the room. + + Any invalid events (those with incorrect or unverifiable signatures or hashes) + are filtered out from the response, and any duplicate events are removed. + + (Size limits and other event-format checks are *not* performed.) + + Note that the result is not ordered, so callers must be careful to process + the events in an order that handles dependencies. + + Returns: + a tuple of (state events, auth events) + """ + result = await self.transport_layer.get_room_state( + room_version, + destination, + room_id, + event_id, + ) + state_events = result.state + auth_events = result.auth_events + + # we may as well filter out any duplicates from the response, to save + # processing them multiple times. (In particular, events may be present in + # `auth_events` as well as `state`, which is redundant). + # + # We don't rely on the sort order of the events, so we can just stick them + # in a dict. + state_event_map = {event.event_id: event for event in state_events} + auth_event_map = { + event.event_id: event + for event in auth_events + if event.event_id not in state_event_map + } + + logger.info( + "Processing from /state: %d state events, %d auth events", + len(state_event_map), + len(auth_event_map), + ) + + valid_auth_events = await self._check_sigs_and_hash_and_fetch( + destination, auth_event_map.values(), room_version + ) + + valid_state_events = await self._check_sigs_and_hash_and_fetch( + destination, state_event_map.values(), room_version + ) + + return valid_state_events, valid_auth_events + async def _check_sigs_and_hash_and_fetch( self, origin: str, pdus: Collection[EventBase], room_version: RoomVersion, ) -> List[EventBase]: - """Takes a list of PDUs and checks the signatures and hashes of each - one. If a PDU fails its signature check then we check if we have it in - the database and if not then request if from the originating server of - that PDU. + """Checks the signatures and hashes of a list of events. + + If a PDU fails its signature check then we check if we have it in + the database, and if not then request it from the sender's server (if that + is different from `origin`). If that still fails, the event is omitted from + the returned list. If a PDU fails its content hash check then it is redacted. - The given list of PDUs are not modified, instead the function returns + Also runs each event through the spam checker; if it fails, redacts the event + and flags it as soft-failed. + + The given list of PDUs are not modified; instead the function returns a new list. Args: - origin - pdu - room_version + origin: The server that sent us these events + pdus: The events to be checked + room_version: the version of the room these events are in Returns: A list of PDUs that have valid signatures and hashes. @@ -469,11 +533,16 @@ class FederationClient(FederationBase): origin: str, room_version: RoomVersion, ) -> Optional[EventBase]: - """Takes a PDU and checks its signatures and hashes. If the PDU fails - its signature check then we check if we have it in the database and if - not then request if from the originating server of that PDU. + """Takes a PDU and checks its signatures and hashes. + + If the PDU fails its signature check then we check if we have it in the + database; if not, we then request it from sender's server (if that is not the + same as `origin`). If that still fails, we return None. + + If the PDU fails its content hash check, it is redacted. - If then PDU fails its content hash check then it is redacted. + Also runs the event through the spam checker; if it fails, redacts the event + and flags it as soft-failed. Args: origin diff --git a/synapse/federation/transport/client.py b/synapse/federation/transport/client.py index dca6e5c45d..7e510e224a 100644 --- a/synapse/federation/transport/client.py +++ b/synapse/federation/transport/client.py @@ -65,13 +65,12 @@ class TransportLayerClient: async def get_room_state_ids( self, destination: str, room_id: str, event_id: str ) -> JsonDict: - """Requests all state for a given room from the given server at the - given event. Returns the state's event_id's + """Requests the IDs of all state for a given room at the given event. Args: destination: The host name of the remote homeserver we want to get the state from. - context: The name of the context we want the state of + room_id: the room we want the state of event_id: The event we want the context at. Returns: @@ -87,6 +86,29 @@ class TransportLayerClient: try_trailing_slash_on_400=True, ) + async def get_room_state( + self, room_version: RoomVersion, destination: str, room_id: str, event_id: str + ) -> "StateRequestResponse": + """Requests the full state for a given room at the given event. + + Args: + room_version: the version of the room (required to build the event objects) + destination: The host name of the remote homeserver we want + to get the state from. + room_id: the room we want the state of + event_id: The event we want the context at. + + Returns: + Results in a dict received from the remote homeserver. + """ + path = _create_v1_path("/state/%s", room_id) + return await self.client.get_json( + destination, + path=path, + args={"event_id": event_id}, + parser=_StateParser(room_version), + ) + async def get_event( self, destination: str, event_id: str, timeout: Optional[int] = None ) -> JsonDict: @@ -1284,6 +1306,14 @@ class SendJoinResponse: servers_in_room: Optional[List[str]] = None +@attr.s(slots=True, auto_attribs=True) +class StateRequestResponse: + """The parsed response of a `/state` request.""" + + auth_events: List[EventBase] + state: List[EventBase] + + @ijson.coroutine def _event_parser(event_dict: JsonDict) -> Generator[None, Tuple[str, Any], None]: """Helper function for use with `ijson.kvitems_coro` to parse key-value pairs @@ -1411,3 +1441,37 @@ class SendJoinParser(ByteParser[SendJoinResponse]): self._response.event_dict, self._room_version ) return self._response + + +class _StateParser(ByteParser[StateRequestResponse]): + """A parser for the response to `/state` requests. + + Args: + room_version: The version of the room. + """ + + CONTENT_TYPE = "application/json" + + def __init__(self, room_version: RoomVersion): + self._response = StateRequestResponse([], []) + self._room_version = room_version + self._coros = [ + ijson.items_coro( + _event_list_parser(room_version, self._response.state), + "pdus.item", + use_float=True, + ), + ijson.items_coro( + _event_list_parser(room_version, self._response.auth_events), + "auth_chain.item", + use_float=True, + ), + ] + + def write(self, data: bytes) -> int: + for c in self._coros: + c.send(data) + return len(data) + + def finish(self) -> StateRequestResponse: + return self._response |