Pass the requester during event serialization. (#15174)

This allows Synapse to properly include the transaction ID in the
unsigned data of events.

changelog.d/15174.bugfix

@@ -0,0 +1 @@
+Add the `transaction_id` in the events included in many endpoints responses.

synapse/events/utils.py

@@ -38,7 +38,7 @@
 )
 from synapse.api.errors import Codes, SynapseError
 from synapse.api.room_versions import RoomVersion
-from synapse.types import JsonDict
+from synapse.types import JsonDict, Requester
 
 from . import EventBase
 
@@ -316,8 +316,9 @@ class SerializeEventConfig:
     as_client_event: bool = True
     # Function to convert from federation format to client format
     event_format: Callable[[JsonDict], JsonDict] = format_event_for_client_v1
-    # ID of the user's auth token - used for namespacing of transaction IDs
-    token_id: Optional[int] = None
+    # The entity that requested the event. This is used to determine whether to include
+    # the transaction_id in the unsigned section of the event.
+    requester: Optional[Requester] = None
     # List of event fields to include. If empty, all fields will be returned.
     only_event_fields: Optional[List[str]] = None
     # Some events can have stripped room state stored in the `unsigned` field.
@@ -367,11 +368,24 @@ def serialize_event(
             e.unsigned["redacted_because"], time_now_ms, config=config
         )
 
-    if config.token_id is not None:
-        if config.token_id == getattr(e.internal_metadata, "token_id", None):
-            txn_id = getattr(e.internal_metadata, "txn_id", None)
-            if txn_id is not None:
-                d["unsigned"]["transaction_id"] = txn_id
+    # If we have a txn_id saved in the internal_metadata, we should include it in the
+    # unsigned section of the event if it was sent by the same session as the one
+    # requesting the event.
+    # There is a special case for guests, because they only have one access token
+    # without associated access_token_id, so we always include the txn_id for events
+    # they sent.
+    txn_id = getattr(e.internal_metadata, "txn_id", None)
+    if txn_id is not None and config.requester is not None:
+        event_token_id = getattr(e.internal_metadata, "token_id", None)
+        if config.requester.user.to_string() == e.sender and (
+            (
+                event_token_id is not None
+                and config.requester.access_token_id is not None
+                and event_token_id == config.requester.access_token_id
+            )
+            or config.requester.is_guest
+        ):
+            d["unsigned"]["transaction_id"] = txn_id
 
     # invite_room_state and knock_room_state are a list of stripped room state events
     # that are meant to provide metadata about a room to an invitee/knocker. They are

synapse/handlers/events.py

@@ -23,7 +23,7 @@
 from synapse.handlers.presence import format_user_presence_state
 from synapse.storage.databases.main.events_worker import EventRedactBehaviour
 from synapse.streams.config import PaginationConfig
-from synapse.types import JsonDict, UserID
+from synapse.types import JsonDict, Requester, UserID
 from synapse.visibility import filter_events_for_client
 
 if TYPE_CHECKING:
@@ -46,13 +46,12 @@ def __init__(self, hs: "HomeServer"):
 
     async def get_stream(
         self,
-        auth_user_id: str,
+        requester: Requester,
         pagin_config: PaginationConfig,
         timeout: int = 0,
         as_client_event: bool = True,
         affect_presence: bool = True,
         room_id: Optional[str] = None,
-        is_guest: bool = False,
     ) -> JsonDict:
         """Fetches the events stream for a given user."""
 
@@ -62,13 +61,12 @@ async def get_stream(
                 raise SynapseError(403, "This room has been blocked on this server")
 
         # send any outstanding server notices to the user.
-        await self._server_notices_sender.on_user_syncing(auth_user_id)
+        await self._server_notices_sender.on_user_syncing(requester.user.to_string())
 
-        auth_user = UserID.from_string(auth_user_id)
         presence_handler = self.hs.get_presence_handler()
 
         context = await presence_handler.user_syncing(
-            auth_user_id,
+            requester.user.to_string(),
             affect_presence=affect_presence,
             presence_state=PresenceState.ONLINE,
         )
@@ -82,10 +80,10 @@ async def get_stream(
                 timeout = random.randint(int(timeout * 0.9), int(timeout * 1.1))
 
             stream_result = await self.notifier.get_events_for(
-                auth_user,
+                requester.user,
                 pagin_config,
                 timeout,
-                is_guest=is_guest,
+                is_guest=requester.is_guest,
                 explicit_room_id=room_id,
             )
             events = stream_result.events
@@ -102,7 +100,7 @@ async def get_stream(
                     if event.membership != Membership.JOIN:
                         continue
                     # Send down presence.
-                    if event.state_key == auth_user_id:
+                    if event.state_key == requester.user.to_string():
                         # Send down presence for everyone in the room.
                         users: Iterable[str] = await self.store.get_users_in_room(
                             event.room_id
@@ -124,7 +122,9 @@ async def get_stream(
             chunks = self._event_serializer.serialize_events(
                 events,
                 time_now,
-                config=SerializeEventConfig(as_client_event=as_client_event),
+                config=SerializeEventConfig(
+                    as_client_event=as_client_event, requester=requester
+                ),
             )
 
             chunk = {

synapse/handlers/initial_sync.py

@@ -318,22 +318,26 @@ async def room_initial_sync(
         )
         is_peeking = member_event_id is None
 
-        user_id = requester.user.to_string()
-
         if membership == Membership.JOIN:
             result = await self._room_initial_sync_joined(
-                user_id, room_id, pagin_config, membership, is_peeking
+                requester, room_id, pagin_config, membership, is_peeking
             )
         elif membership == Membership.LEAVE:
             # The member_event_id will always be available if membership is set
             # to leave.
             assert member_event_id
 
             result = await self._room_initial_sync_parted(
-                user_id, room_id, pagin_config, membership, member_event_id, is_peeking
+                requester,
+                room_id,
+                pagin_config,
+                membership,
+                member_event_id,
+                is_peeking,
             )
 
         account_data_events = []
+        user_id = requester.user.to_string()
         tags = await self.store.get_tags_for_room(user_id, room_id)
         if tags:
             account_data_events.append(
@@ -350,7 +354,7 @@ async def room_initial_sync(
 
     async def _room_initial_sync_parted(
         self,
-        user_id: str,
+        requester: Requester,
         room_id: str,
         pagin_config: PaginationConfig,
         membership: str,
@@ -369,36 +373,44 @@ async def _room_initial_sync_parted(
         )
 
         messages = await filter_events_for_client(
-            self._storage_controllers, user_id, messages, is_peeking=is_peeking
+            self._storage_controllers,
+            requester.user.to_string(),
+            messages,
+            is_peeking=is_peeking,
         )
 
         start_token = StreamToken.START.copy_and_replace(StreamKeyType.ROOM, token)
         end_token = StreamToken.START.copy_and_replace(StreamKeyType.ROOM, stream_token)
 
         time_now = self.clock.time_msec()
+        serialize_options = SerializeEventConfig(requester=requester)
 
         return {
             "membership": membership,
             "room_id": room_id,
             "messages": {
                 "chunk": (
                     # Don't bundle aggregations as this is a deprecated API.
-                    self._event_serializer.serialize_events(messages, time_now)
+                    self._event_serializer.serialize_events(
+                        messages, time_now, config=serialize_options
+                    )
                 ),
                 "start": await start_token.to_string(self.store),
                 "end": await end_token.to_string(self.store),
             },
             "state": (
                 # Don't bundle aggregations as this is a deprecated API.
-                self._event_serializer.serialize_events(room_state.values(), time_now)
+                self._event_serializer.serialize_events(
+                    room_state.values(), time_now, config=serialize_options
+                )
             ),
             "presence": [],
             "receipts": [],
         }
 
     async def _room_initial_sync_joined(
         self,
-        user_id: str,
+        requester: Requester,
         room_id: str,
         pagin_config: PaginationConfig,
         membership: str,
@@ -410,9 +422,12 @@ async def _room_initial_sync_joined(
 
         # TODO: These concurrently
         time_now = self.clock.time_msec()
+        serialize_options = SerializeEventConfig(requester=requester)
         # Don't bundle aggregations as this is a deprecated API.
         state = self._event_serializer.serialize_events(
-            current_state.values(), time_now
+            current_state.values(),
+            time_now,
+            config=serialize_options,
         )
 
         now_token = self.hs.get_event_sources().get_current_token()
@@ -450,7 +465,10 @@ async def get_receipts() -> List[JsonDict]:
             if not receipts:
                 return []
 
-            return ReceiptEventSource.filter_out_private_receipts(receipts, user_id)
+            return ReceiptEventSource.filter_out_private_receipts(
+                receipts,
+                requester.user.to_string(),
+            )
 
         presence, receipts, (messages, token) = await make_deferred_yieldable(
             gather_results(
@@ -469,20 +487,23 @@ async def get_receipts() -> List[JsonDict]:
         )
 
         messages = await filter_events_for_client(
-            self._storage_controllers, user_id, messages, is_peeking=is_peeking
+            self._storage_controllers,
+            requester.user.to_string(),
+            messages,
+            is_peeking=is_peeking,
         )
 
         start_token = now_token.copy_and_replace(StreamKeyType.ROOM, token)
         end_token = now_token
 
-        time_now = self.clock.time_msec()
-
         ret = {
             "room_id": room_id,
             "messages": {
                 "chunk": (
                     # Don't bundle aggregations as this is a deprecated API.
-                    self._event_serializer.serialize_events(messages, time_now)
+                    self._event_serializer.serialize_events(
+                        messages, time_now, config=serialize_options
+                    )
                 ),
                 "start": await start_token.to_string(self.store),
                 "end": await end_token.to_string(self.store),

synapse/handlers/message.py

@@ -50,7 +50,7 @@
 from synapse.events import EventBase, relation_from_event
 from synapse.events.builder import EventBuilder
 from synapse.events.snapshot import EventContext, UnpersistedEventContextBase
-from synapse.events.utils import maybe_upsert_event_field
+from synapse.events.utils import SerializeEventConfig, maybe_upsert_event_field
 from synapse.events.validator import EventValidator
 from synapse.handlers.directory import DirectoryHandler
 from synapse.logging import opentracing
@@ -245,8 +245,11 @@ async def get_state_events(
                 )
                 room_state = room_state_events[membership_event_id]
 
-        now = self.clock.time_msec()
-        events = self._event_serializer.serialize_events(room_state.values(), now)
+        events = self._event_serializer.serialize_events(
+            room_state.values(),
+            self.clock.time_msec(),
+            config=SerializeEventConfig(requester=requester),
+        )
         return events
 
     async def _user_can_see_state_at_event(

synapse/handlers/pagination.py

@@ -579,7 +579,9 @@ async def get_messages(
 
         time_now = self.clock.time_msec()
 
-        serialize_options = SerializeEventConfig(as_client_event=as_client_event)
+        serialize_options = SerializeEventConfig(
+            as_client_event=as_client_event, requester=requester
+        )
 
         chunk = {
             "chunk": (

synapse/handlers/relations.py

@@ -20,6 +20,7 @@
 from synapse.api.constants import Direction, EventTypes, RelationTypes
 from synapse.api.errors import SynapseError
 from synapse.events import EventBase, relation_from_event
+from synapse.events.utils import SerializeEventConfig
 from synapse.logging.context import make_deferred_yieldable, run_in_background
 from synapse.logging.opentracing import trace
 from synapse.storage.databases.main.relations import ThreadsNextBatch, _RelatedEvent
@@ -151,16 +152,23 @@ async def get_relations(
         )
 
         now = self._clock.time_msec()
+        serialize_options = SerializeEventConfig(requester=requester)
         return_value: JsonDict = {
             "chunk": self._event_serializer.serialize_events(
-                events, now, bundle_aggregations=aggregations
+                events,
+                now,
+                bundle_aggregations=aggregations,
+                config=serialize_options,
             ),
         }
         if include_original_event:
             # Do not bundle aggregations when retrieving the original event because
             # we want the content before relations are applied to it.
             return_value["original_event"] = self._event_serializer.serialize_event(
-                event, now, bundle_aggregations=None
+                event,
+                now,
+                bundle_aggregations=None,
+                config=serialize_options,
             )
 
         if next_token: