diff --git a/changelog.d/10447.feature b/changelog.d/10447.feature
new file mode 100644
index 0000000000..df8bb51167
--- /dev/null
+++ b/changelog.d/10447.feature
@@ -0,0 +1 @@
+Update support for [MSC3083](https://github.com/matrix-org/matrix-doc/pull/3083) to consider changes in the MSC around which servers can issue join events.
diff --git a/synapse/federation/federation_client.py b/synapse/federation/federation_client.py
index dbadf102f2..b7a10da15a 100644
--- a/synapse/federation/federation_client.py
+++ b/synapse/federation/federation_client.py
@@ -22,6 +22,7 @@ from typing import (
Awaitable,
Callable,
Collection,
+ Container,
Dict,
Iterable,
List,
@@ -513,6 +514,7 @@ class FederationClient(FederationBase):
description: str,
destinations: Iterable[str],
callback: Callable[[str], Awaitable[T]],
+ failover_errcodes: Optional[Container[str]] = None,
failover_on_unknown_endpoint: bool = False,
) -> T:
"""Try an operation on a series of servers, until it succeeds
@@ -533,6 +535,9 @@ class FederationClient(FederationBase):
next server tried. Normally the stacktrace is logged but this is
suppressed if the exception is an InvalidResponseError.
+ failover_errcodes: Error codes (specific to this endpoint) which should
+ cause a failover when received as part of an HTTP 400 error.
+
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.
@@ -544,6 +549,9 @@ class FederationClient(FederationBase):
SynapseError if the chosen remote server returns a 300/400 code, or
no servers were reachable.
"""
+ if failover_errcodes is None:
+ failover_errcodes = ()
+
for destination in destinations:
if destination == self.server_name:
continue
@@ -558,11 +566,17 @@ class FederationClient(FederationBase):
synapse_error = e.to_synapse_error()
failover = False
- # Failover on an internal server error, or if the destination
- # doesn't implemented the endpoint for some reason.
+ # Failover should occur:
+ #
+ # * On internal server errors.
+ # * If the destination responds that it cannot complete the request.
+ # * If the destination doesn't implemented the endpoint for some reason.
if 500 <= e.code < 600:
failover = True
+ elif e.code == 400 and synapse_error.errcode in failover_errcodes:
+ failover = True
+
elif failover_on_unknown_endpoint and self._is_unknown_endpoint(
e, synapse_error
):
@@ -678,8 +692,20 @@ class FederationClient(FederationBase):
return destination, ev, room_version
+ # MSC3083 defines additional error codes for room joins. Unfortunately
+ # we do not yet know the room version, assume these will only be returned
+ # by valid room versions.
+ failover_errcodes = (
+ (Codes.UNABLE_AUTHORISE_JOIN, Codes.UNABLE_TO_GRANT_JOIN)
+ if membership == Membership.JOIN
+ else None
+ )
+
return await self._try_destination_list(
- "make_" + membership, destinations, send_request
+ "make_" + membership,
+ destinations,
+ send_request,
+ failover_errcodes=failover_errcodes,
)
async def send_join(
@@ -818,7 +844,14 @@ class FederationClient(FederationBase):
origin=destination,
)
+ # MSC3083 defines additional error codes for room joins.
+ failover_errcodes = None
if room_version.msc3083_join_rules:
+ failover_errcodes = (
+ Codes.UNABLE_AUTHORISE_JOIN,
+ Codes.UNABLE_TO_GRANT_JOIN,
+ )
+
# If the join is being authorised via allow rules, we need to send
# the /send_join back to the same server that was originally used
# with /make_join.
@@ -827,7 +860,9 @@ class FederationClient(FederationBase):
get_domain_from_id(pdu.content["join_authorised_via_users_server"])
]
- return await self._try_destination_list("send_join", destinations, send_request)
+ return await self._try_destination_list(
+ "send_join", destinations, send_request, failover_errcodes=failover_errcodes
+ )
async def _do_send_join(
self, room_version: RoomVersion, destination: str, pdu: EventBase
|
