diff options
Diffstat (limited to 'synapse/federation/federation_client.py')
| -rw-r--r-- | synapse/federation/federation_client.py | 180 |
1 files changed, 170 insertions, 10 deletions
diff --git a/synapse/federation/federation_client.py b/synapse/federation/federation_client.py index 3b2f51baab..afdb5bf2fa 100644 --- a/synapse/federation/federation_client.py +++ b/synapse/federation/federation_client.py @@ -27,11 +27,13 @@ from typing import ( List, Mapping, Optional, + Sequence, Tuple, TypeVar, Union, ) +import attr from prometheus_client import Counter from twisted.internet import defer @@ -455,6 +457,7 @@ class FederationClient(FederationBase): description: str, destinations: Iterable[str], callback: Callable[[str], Awaitable[T]], + failover_on_unknown_endpoint: bool = False, ) -> T: """Try an operation on a series of servers, until it succeeds @@ -474,6 +477,10 @@ class FederationClient(FederationBase): next server tried. Normally the stacktrace is logged but this is suppressed if the exception is an InvalidResponseError. + failover_on_unknown_endpoint: if True, we will try other servers if it looks + like a server doesn't support the endpoint. This is typically useful + if the endpoint in question is new or experimental. + Returns: The result of callback, if it succeeds @@ -493,16 +500,31 @@ class FederationClient(FederationBase): except UnsupportedRoomVersionError: raise except HttpResponseException as e: - if not 500 <= e.code < 600: - raise e.to_synapse_error() - else: - logger.warning( - "Failed to %s via %s: %i %s", - description, - destination, - e.code, - e.args[0], - ) + synapse_error = e.to_synapse_error() + failover = False + + if 500 <= e.code < 600: + failover = True + + elif failover_on_unknown_endpoint: + # there is no good way to detect an "unknown" endpoint. Dendrite + # returns a 404 (with no body); synapse returns a 400 + # with M_UNRECOGNISED. + if e.code == 404 or ( + e.code == 400 and synapse_error.errcode == Codes.UNRECOGNIZED + ): + failover = True + + if not failover: + raise synapse_error from e + + logger.warning( + "Failed to %s via %s: %i %s", + description, + destination, + e.code, + e.args[0], + ) except Exception: logger.warning( "Failed to %s via %s", description, destination, exc_info=True @@ -1042,3 +1064,141 @@ class FederationClient(FederationBase): # If we don't manage to find it, return None. It's not an error if a # server doesn't give it to us. return None + + async def get_space_summary( + self, + destinations: Iterable[str], + room_id: str, + suggested_only: bool, + max_rooms_per_space: Optional[int], + exclude_rooms: List[str], + ) -> "FederationSpaceSummaryResult": + """ + Call other servers to get a summary of the given space + + + Args: + destinations: The remote servers. We will try them in turn, omitting any + that have been blacklisted. + + room_id: ID of the space to be queried + + suggested_only: If true, ask the remote server to only return children + with the "suggested" flag set + + max_rooms_per_space: A limit on the number of children to return for each + space + + exclude_rooms: A list of room IDs to tell the remote server to skip + + Returns: + a parsed FederationSpaceSummaryResult + + Raises: + SynapseError if we were unable to get a valid summary from any of the + remote servers + """ + + async def send_request(destination: str) -> FederationSpaceSummaryResult: + res = await self.transport_layer.get_space_summary( + destination=destination, + room_id=room_id, + suggested_only=suggested_only, + max_rooms_per_space=max_rooms_per_space, + exclude_rooms=exclude_rooms, + ) + + try: + return FederationSpaceSummaryResult.from_json_dict(res) + except ValueError as e: + raise InvalidResponseError(str(e)) + + return await self._try_destination_list( + "fetch space summary", + destinations, + send_request, + failover_on_unknown_endpoint=True, + ) + + +@attr.s(frozen=True, slots=True) +class FederationSpaceSummaryEventResult: + """Represents a single event in the result of a successful get_space_summary call. + + It's essentially just a serialised event object, but we do a bit of parsing and + validation in `from_json_dict` and store some of the validated properties in + object attributes. + """ + + event_type = attr.ib(type=str) + state_key = attr.ib(type=str) + via = attr.ib(type=Sequence[str]) + + # the raw data, including the above keys + data = attr.ib(type=JsonDict) + + @classmethod + def from_json_dict(cls, d: JsonDict) -> "FederationSpaceSummaryEventResult": + """Parse an event within the result of a /spaces/ request + + Args: + d: json object to be parsed + + Raises: + ValueError if d is not a valid event + """ + + event_type = d.get("type") + if not isinstance(event_type, str): + raise ValueError("Invalid event: 'event_type' must be a str") + + state_key = d.get("state_key") + if not isinstance(state_key, str): + raise ValueError("Invalid event: 'state_key' must be a str") + + content = d.get("content") + if not isinstance(content, dict): + raise ValueError("Invalid event: 'content' must be a dict") + + via = content.get("via") + if not isinstance(via, Sequence): + raise ValueError("Invalid event: 'via' must be a list") + if any(not isinstance(v, str) for v in via): + raise ValueError("Invalid event: 'via' must be a list of strings") + + return cls(event_type, state_key, via, d) + + +@attr.s(frozen=True, slots=True) +class FederationSpaceSummaryResult: + """Represents the data returned by a successful get_space_summary call.""" + + rooms = attr.ib(type=Sequence[JsonDict]) + events = attr.ib(type=Sequence[FederationSpaceSummaryEventResult]) + + @classmethod + def from_json_dict(cls, d: JsonDict) -> "FederationSpaceSummaryResult": + """Parse the result of a /spaces/ request + + Args: + d: json object to be parsed + + Raises: + ValueError if d is not a valid /spaces/ response + """ + rooms = d.get("rooms") + if not isinstance(rooms, Sequence): + raise ValueError("'rooms' must be a list") + if any(not isinstance(r, dict) for r in rooms): + raise ValueError("Invalid room in 'rooms' list") + + events = d.get("events") + if not isinstance(events, Sequence): + raise ValueError("'events' must be a list") + if any(not isinstance(e, dict) for e in events): + raise ValueError("Invalid event in 'events' list") + parsed_events = [ + FederationSpaceSummaryEventResult.from_json_dict(e) for e in events + ] + + return cls(rooms, parsed_events) |