# Copyright 2014-2022 The Matrix.org Foundation C.I.C. # Copyright 2020 Sorunome # # 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 import urllib from typing import ( Any, Callable, Collection, Dict, Generator, Iterable, List, Mapping, Optional, Tuple, Union, ) import attr import ijson from synapse.api.constants import Membership from synapse.api.errors import Codes, HttpResponseException, SynapseError from synapse.api.room_versions import RoomVersion from synapse.api.urls import ( FEDERATION_UNSTABLE_PREFIX, FEDERATION_V1_PREFIX, FEDERATION_V2_PREFIX, ) from synapse.events import EventBase, make_event_from_dict from synapse.federation.units import Transaction from synapse.http.matrixfederationclient import ByteParser from synapse.http.types import QueryParams from synapse.types import JsonDict from synapse.util import ExceptionBundle logger = logging.getLogger(__name__) class TransportLayerClient: """Sends federation HTTP requests to other servers""" def __init__(self, hs): self.server_name = hs.hostname self.client = hs.get_federation_http_client() self._faster_joins_enabled = hs.config.experimental.faster_joins_enabled async def get_room_state_ids( self, destination: str, room_id: str, event_id: str ) -> JsonDict: """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. 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. """ logger.debug("get_room_state_ids dest=%s, room=%s", destination, room_id) path = _create_v1_path("/state_ids/%s", room_id) return await self.client.get_json( destination, path=path, args={"event_id": event_id}, 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: """Requests the pdu with give id and origin from the given server. Args: destination: The host name of the remote homeserver we want to get the state from. event_id: The id of the event being requested. timeout: How long to try (in ms) the destination for before giving up. None indicates no timeout. Returns: Results in a dict received from the remote homeserver. """ logger.debug("get_pdu dest=%s, event_id=%s", destination, event_id) path = _create_v1_path("/event/%s", event_id) return await self.client.get_json( destination, path=path, timeout=timeout, try_trailing_slash_on_400=True ) async def backfill( self, destination: str, room_id: str, event_tuples: Collection[str], limit: int ) -> Optional[JsonDict]: """Requests `limit` previous PDUs in a given context before list of PDUs. Args: destination room_id event_tuples: Must be a Collection that is falsy when empty. (Iterable is not enough here!) limit Returns: Results in a dict received from the remote homeserver. """ logger.debug( "backfill dest=%s, room_id=%s, event_tuples=%r, limit=%s", destination, room_id, event_tuples, str(limit), ) if not event_tuples: # TODO: raise? return None path = _create_v1_path("/backfill/%s", room_id) args = {"v": event_tuples, "limit": [str(limit)]} return await self.client.get_json( destination, path=path, args=args, try_trailing_slash_on_400=True ) async def timestamp_to_event( self, destination: str, room_id: str, timestamp: int, direction: str ) -> Union[JsonDict, List]: """ Calls a remote federating server at `destination` asking for their closest event to the given timestamp in the given direction. Args: destination: Domain name of the remote homeserver room_id: Room to fetch the event from timestamp: The point in time (inclusive) we should navigate from in the given direction to find the closest event. direction: ["f"|"b"] to indicate whether we should navigate forward or backward from the given timestamp to find the closest event. Returns: Response dict received from the remote homeserver. Raises: Various exceptions when the request fails """ path = _create_v1_path( "/timestamp_to_event/%s", room_id, ) args = {"ts": [str(timestamp)], "dir": [direction]} remote_response = await self.client.get_json( destination, path=path, args=args, try_trailing_slash_on_400=True ) return remote_response async def send_transaction( self, transaction: Transaction, json_data_callback: Optional[Callable[[], JsonDict]] = None, ) -> JsonDict: """Sends the given Transaction to its destination Args: transaction Returns: Succeeds when we get a 2xx HTTP response. The result 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. Fails with ``FederationDeniedError`` if this destination is not on our federation whitelist """ logger.debug( "send_data dest=%s, txid=%s", transaction.destination, transaction.transaction_id, ) if transaction.destination == self.server_name: raise RuntimeError("Transport layer cannot send to itself!") # FIXME: This is only used by the tests. The actual json sent is # generated by the json_data_callback. json_data = transaction.get_dict() path = _create_v1_path("/send/%s", transaction.transaction_id) return await self.client.put_json( transaction.destination, path=path, data=json_data, json_data_callback=json_data_callback, long_retries=True, backoff_on_404=True, # If we get a 404 the other side has gone try_trailing_slash_on_400=True, ) async def make_query( self, destination: str, query_type: str, args: QueryParams, retry_on_dns_fail: bool, ignore_backoff: bool = False, prefix: str = FEDERATION_V1_PREFIX, ) -> JsonDict: path = _create_path(prefix, "/query/%s", query_type) return await self.client.get_json( destination=destination, path=path, args=args, retry_on_dns_fail=retry_on_dns_fail, timeout=10000, ignore_backoff=ignore_backoff, ) async def make_membership_event( self, destination: str, room_id: str, user_id: str, membership: str, params: Optional[Mapping[str, Union[str, Iterable[str]]]], ) -> JsonDict: """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: address of remote homeserver room_id: room to join/leave user_id: user to be joined/left membership: one of join/leave params: Query parameters to include in the request. Returns: 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. Fails with ``FederationDeniedError`` if the remote destination is not in our federation whitelist """ valid_memberships = {Membership.JOIN, Membership.LEAVE, Membership.KNOCK} if membership not in valid_memberships: raise RuntimeError( "make_membership_event called with membership='%s', must be one of %s" % (membership, ",".join(valid_memberships)) ) path = _create_v1_path("/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 return await self.client.get_json( destination=destination, path=path, args=params, retry_on_dns_fail=retry_on_dns_fail, timeout=20000, ignore_backoff=ignore_backoff, ) async def send_join_v1( self, room_version: RoomVersion, destination: str, room_id: str, event_id: str, content: JsonDict, ) -> "SendJoinResponse": path = _create_v1_path("/send_join/%s/%s", room_id, event_id) return await self.client.put_json( destination=destination, path=path, data=content, parser=SendJoinParser(room_version, v1_api=True), ) async def send_join_v2( self, room_version: RoomVersion, destination: str, room_id: str, event_id: str, content: JsonDict, ) -> "SendJoinResponse": path = _create_v2_path("/send_join/%s/%s", room_id, event_id) query_params: Dict[str, str] = {} if self._faster_joins_enabled: # lazy-load state on join query_params["org.matrix.msc3706.partial_state"] = "true" return await self.client.put_json( destination=destination, path=path, args=query_params, data=content, parser=SendJoinParser(room_version, v1_api=False), ) async def send_leave_v1( self, destination: str, room_id: str, event_id: str, content: JsonDict ) -> Tuple[int, JsonDict]: path = _create_v1_path("/send_leave/%s/%s", room_id, event_id) return await self.client.put_json( 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, ) async def send_leave_v2( self, destination: str, room_id: str, event_id: str, content: JsonDict ) -> JsonDict: path = _create_v2_path("/send_leave/%s/%s", room_id, event_id) return await self.client.put_json( 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, ) async def send_knock_v1( self, destination: str, room_id: str, event_id: str, content: JsonDict, ) -> JsonDict: """ Sends a signed knock membership event to a remote server. This is the second step for knocking after make_knock. Args: destination: The remote homeserver. room_id: The ID of the room to knock on. event_id: The ID of the knock membership event that we're sending. content: The knock membership event that we're sending. Note that this is not the `content` field of the membership event, but the entire signed membership event itself represented as a JSON dict. Returns: The remote homeserver can optionally return some state from the room. The response dictionary is in the form: {"knock_state_events": [, ...]} The list of state events may be empty. """ path = _create_v1_path("/send_knock/%s/%s", room_id, event_id) return await self.client.put_json( destination=destination, path=path, data=content ) async def send_invite_v1( self, destination: str, room_id: str, event_id: str, content: JsonDict ) -> Tuple[int, JsonDict]: path = _create_v1_path("/invite/%s/%s", room_id, event_id) return await self.client.put_json( destination=destination, path=path, data=content, ignore_backoff=True ) async def send_invite_v2( self, destination: str, room_id: str, event_id: str, content: JsonDict ) -> JsonDict: path = _create_v2_path("/invite/%s/%s", room_id, event_id) return await self.client.put_json( destination=destination, path=path, data=content, ignore_backoff=True ) async def get_public_rooms( self, remote_server: str, limit: Optional[int] = None, since_token: Optional[str] = None, search_filter: Optional[Dict] = None, include_all_networks: bool = False, third_party_instance_id: Optional[str] = None, ) -> JsonDict: """Get the list of public rooms from a remote homeserver See synapse.federation.federation_client.FederationClient.get_public_rooms for more information. """ if search_filter: # this uses MSC2197 (Search Filtering over Federation) path = _create_v1_path("/publicRooms") data: Dict[str, Any] = { "include_all_networks": "true" if include_all_networks else "false" } if third_party_instance_id: data["third_party_instance_id"] = third_party_instance_id if limit: data["limit"] = limit if since_token: data["since"] = since_token data["filter"] = search_filter try: response = await self.client.post_json( destination=remote_server, path=path, data=data, ignore_backoff=True ) except HttpResponseException as e: if e.code == 403: raise SynapseError( 403, "You are not allowed to view the public rooms list of %s" % (remote_server,), errcode=Codes.FORBIDDEN, ) raise else: path = _create_v1_path("/publicRooms") args: Dict[str, Union[str, Iterable[str]]] = { "include_all_networks": "true" if include_all_networks else "false" } if third_party_instance_id: args["third_party_instance_id"] = (third_party_instance_id,) if limit: args["limit"] = [str(limit)] if since_token: args["since"] = [since_token] try: response = await self.client.get_json( destination=remote_server, path=path, args=args, ignore_backoff=True ) except HttpResponseException as e: if e.code == 403: raise SynapseError( 403, "You are not allowed to view the public rooms list of %s" % (remote_server,), errcode=Codes.FORBIDDEN, ) raise return response async def exchange_third_party_invite( self, destination: str, room_id: str, event_dict: JsonDict ) -> JsonDict: path = _create_v1_path("/exchange_third_party_invite/%s", room_id) return await self.client.put_json( destination=destination, path=path, data=event_dict ) async def get_event_auth( self, destination: str, room_id: str, event_id: str ) -> JsonDict: path = _create_v1_path("/event_auth/%s/%s", room_id, event_id) return await self.client.get_json(destination=destination, path=path) async def query_client_keys( self, destination: str, query_content: JsonDict, timeout: int ) -> JsonDict: """Query the device keys for a list of user ids hosted on a remote server. Request: { "device_keys": { "": [""] } } Response: { "device_keys": { "": { "": {...} } }, "master_key": { "": {...} } }, "self_signing_key": { "": {...} } } Args: destination: The server to query. query_content: The user ids to query. Returns: A dict containing device and cross-signing keys. """ path = _create_v1_path("/user/keys/query") return await self.client.post_json( destination=destination, path=path, data=query_content, timeout=timeout ) async def query_user_devices( self, destination: str, user_id: str, timeout: int ) -> JsonDict: """Query the devices for a user id hosted on a remote server. Response: { "stream_id": "...", "devices": [ { ... } ], "master_key": { "user_id": "", "usage": [...], "keys": {...}, "signatures": { "": {...} } }, "self_signing_key": { "user_id": "", "usage": [...], "keys": {...}, "signatures": { "": {...} } } } Args: destination: The server to query. query_content: The user ids to query. Returns: A dict containing device and cross-signing keys. """ path = _create_v1_path("/user/devices/%s", user_id) return await self.client.get_json( destination=destination, path=path, timeout=timeout ) async def claim_client_keys( self, destination: str, query_content: JsonDict, timeout: Optional[int] ) -> JsonDict: """Claim one-time keys for a list of devices hosted on a remote server. Request: { "one_time_keys": { "": { "": "" } } } Response: { "device_keys": { "": { "": { ":": "" } } } } Args: destination: The server to query. query_content: The user ids to query. Returns: A dict containing the one-time keys. """ path = _create_v1_path("/user/keys/claim") return await self.client.post_json( destination=destination, path=path, data=query_content, timeout=timeout ) async def get_missing_events( self, destination: str, room_id: str, earliest_events: Iterable[str], latest_events: Iterable[str], limit: int, min_depth: int, timeout: int, ) -> JsonDict: path = _create_v1_path("/get_missing_events/%s", room_id) return await self.client.post_json( destination=destination, path=path, data={ "limit": int(limit), "min_depth": int(min_depth), "earliest_events": earliest_events, "latest_events": latest_events, }, timeout=timeout, ) async def get_room_complexity(self, destination: str, room_id: str) -> JsonDict: """ Args: destination: The remote server room_id: The room ID to ask about. """ path = _create_path(FEDERATION_UNSTABLE_PREFIX, "/rooms/%s/complexity", room_id) return await self.client.get_json(destination=destination, path=path) async def get_room_hierarchy( self, destination: str, room_id: str, suggested_only: bool ) -> JsonDict: """ Args: destination: The remote server room_id: The room ID to ask about. suggested_only: if True, only suggested rooms will be returned """ path = _create_v1_path("/hierarchy/%s", room_id) return await self.client.get_json( destination=destination, path=path, args={"suggested_only": "true" if suggested_only else "false"}, ) async def get_room_hierarchy_unstable( self, destination: str, room_id: str, suggested_only: bool ) -> JsonDict: """ Args: destination: The remote server room_id: The room ID to ask about. suggested_only: if True, only suggested rooms will be returned """ path = _create_path( FEDERATION_UNSTABLE_PREFIX, "/org.matrix.msc2946/hierarchy/%s", room_id ) return await self.client.get_json( destination=destination, path=path, args={"suggested_only": "true" if suggested_only else "false"}, ) async def get_account_status( self, destination: str, user_ids: List[str] ) -> JsonDict: """ Args: destination: The remote server. user_ids: The user ID(s) for which to request account status(es). """ path = _create_path( FEDERATION_UNSTABLE_PREFIX, "/org.matrix.msc3720/account_status" ) return await self.client.post_json( destination=destination, path=path, data={"user_ids": user_ids} ) def _create_path(federation_prefix: str, path: str, *args: str) -> str: """ Ensures that all args are url encoded. """ return federation_prefix + path % tuple(urllib.parse.quote(arg, "") for arg in args) def _create_v1_path(path: str, *args: str) -> str: """Creates a path against V1 federation API from the path template and args. Ensures that all args are url encoded. Example: _create_v1_path("/event/%s", event_id) Args: path: String template for the path args: Args to insert into path. Each arg will be url encoded """ return _create_path(FEDERATION_V1_PREFIX, path, *args) def _create_v2_path(path: str, *args: str) -> str: """Creates a path against V2 federation API from the path template and args. Ensures that all args are url encoded. Example: _create_v2_path("/event/%s", event_id) Args: path: String template for the path args: Args to insert into path. Each arg will be url encoded """ return _create_path(FEDERATION_V2_PREFIX, path, *args) @attr.s(slots=True, auto_attribs=True) class SendJoinResponse: """The parsed response of a `/send_join` request.""" # The list of auth events from the /send_join response. auth_events: List[EventBase] # The list of state from the /send_join response. state: List[EventBase] # The raw join event from the /send_join response. event_dict: JsonDict # The parsed join event from the /send_join response. This will be None if # "event" is not included in the response. event: Optional[EventBase] = None # The room state is incomplete partial_state: bool = False # List of servers in the room 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 to add them to a given dictionary. """ while True: key, value = yield event_dict[key] = value @ijson.coroutine def _event_list_parser( room_version: RoomVersion, events: List[EventBase] ) -> Generator[None, JsonDict, None]: """Helper function for use with `ijson.items_coro` to parse an array of events and add them to the given list. """ while True: obj = yield event = make_event_from_dict(obj, room_version) events.append(event) @ijson.coroutine def _partial_state_parser(response: SendJoinResponse) -> Generator[None, Any, None]: """Helper function for use with `ijson.items_coro` Parses the partial_state field in send_join responses """ while True: val = yield if not isinstance(val, bool): raise TypeError("partial_state must be a boolean") response.partial_state = val @ijson.coroutine def _servers_in_room_parser(response: SendJoinResponse) -> Generator[None, Any, None]: """Helper function for use with `ijson.items_coro` Parses the servers_in_room field in send_join responses """ while True: val = yield if not isinstance(val, list) or any(not isinstance(x, str) for x in val): raise TypeError("servers_in_room must be a list of strings") response.servers_in_room = val class SendJoinParser(ByteParser[SendJoinResponse]): """A parser for the response to `/send_join` requests. Args: room_version: The version of the room. v1_api: Whether the response is in the v1 format. """ CONTENT_TYPE = "application/json" # /send_join responses can be huge, so we override the size limit here. The response # is parsed in a streaming manner, which helps alleviate the issue of memory # usage a bit. MAX_RESPONSE_SIZE = 500 * 1024 * 1024 def __init__(self, room_version: RoomVersion, v1_api: bool): self._response = SendJoinResponse([], [], event_dict={}) self._room_version = room_version self._coros: List[Generator[None, bytes, None]] = [] # The V1 API has the shape of `[200, {...}]`, which we handle by # prefixing with `item.*`. prefix = "item." if v1_api else "" self._coros = [ ijson.items_coro( _event_list_parser(room_version, self._response.state), prefix + "state.item", use_float=True, ), ijson.items_coro( _event_list_parser(room_version, self._response.auth_events), prefix + "auth_chain.item", use_float=True, ), ijson.kvitems_coro( _event_parser(self._response.event_dict), prefix + "event", use_float=True, ), ] if not v1_api: self._coros.append( ijson.items_coro( _partial_state_parser(self._response), "org.matrix.msc3706.partial_state", use_float="True", ) ) self._coros.append( ijson.items_coro( _servers_in_room_parser(self._response), "org.matrix.msc3706.servers_in_room", use_float="True", ) ) def write(self, data: bytes) -> int: for c in self._coros: c.send(data) return len(data) def finish(self) -> SendJoinResponse: _close_coros(self._coros) if self._response.event_dict: self._response.event = make_event_from_dict( 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" # As with /send_join, /state responses can be huge. MAX_RESPONSE_SIZE = 500 * 1024 * 1024 def __init__(self, room_version: RoomVersion): self._response = StateRequestResponse([], []) self._room_version = room_version self._coros: List[Generator[None, bytes, None]] = [ 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: _close_coros(self._coros) return self._response def _close_coros(coros: Iterable[Generator[None, bytes, None]]) -> None: """Close each of the given coroutines. Always calls .close() on each coroutine, even if doing so raises an exception. Any exceptions raised are aggregated into an ExceptionBundle. :raises ExceptionBundle: if at least one coroutine fails to close. """ exceptions = [] for c in coros: try: c.close() except Exception as e: exceptions.append(e) if exceptions: # raise from the first exception so that the traceback has slightly more context raise ExceptionBundle( f"There were {len(exceptions)} errors closing coroutines", exceptions ) from exceptions[0]