Skip to content
This repository has been archived by the owner on Apr 26, 2024. It is now read-only.

Fix joining rooms you have been unbanned from #15323

Merged
merged 3 commits into from
Mar 29, 2023
Merged

Fix joining rooms you have been unbanned from #15323

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
3 commits
Select commit Hold shift + click to select a range
7bf026c
Fix joining rooms you have been unbanned from
deepbluev7 Mar 25, 2023
e3c5aea
Add changelog
deepbluev7 Mar 25, 2023
961b40f
Update changelog.d/15323.bugfix
reivilibre Mar 29, 2023
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
1 change: 1 addition & 0 deletions changelog.d/15323.bugfix
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -0,0 +1 @@
Fix a long-standing bug preventing users from joining rooms, that they had been unbanned from, over federation. Contributed by Nico.
2 changes: 1 addition & 1 deletion synapse/handlers/federation_event.py
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -583,7 +583,7 @@ async def process_remote_join(

await self._check_event_auth(origin, event, context)
if context.rejected:
raise SynapseError(400, "Join event was rejected")
raise SynapseError(403, "Join event was rejected")

# the remote server is responsible for sending our join event to the rest
# of the federation. Indeed, attempting to do so will result in problems
Expand Down
109 changes: 57 additions & 52 deletions synapse/handlers/room_member.py
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -850,63 +850,68 @@ async def update_membership_locked(
# `is_partial_state_room` also indicates whether `partial_state_before_join` is
# partial.

# TODO: Refactor into dictionary of explicitly allowed transitions
# between old and new state, with specific error messages for some
# transitions and generic otherwise
old_state_id = partial_state_before_join.get(
(EventTypes.Member, target.to_string())
)
if old_state_id:
old_state = await self.store.get_event(old_state_id, allow_none=True)
old_membership = old_state.content.get("membership") if old_state else None
if action == "unban" and old_membership != "ban":
raise SynapseError(
403,
"Cannot unban user who was not banned"
" (membership=%s)" % old_membership,
errcode=Codes.BAD_STATE,
)
if old_membership == "ban" and action not in ["ban", "unban", "leave"]:
raise SynapseError(
403,
"Cannot %s user who was banned" % (action,),
errcode=Codes.BAD_STATE,
)

if old_state:
same_content = content == old_state.content
same_membership = old_membership == effective_membership_state
same_sender = requester.user.to_string() == old_state.sender
if same_sender and same_membership and same_content:
# duplicate event.
# we know it was persisted, so must have a stream ordering.
assert old_state.internal_metadata.stream_ordering
return (
old_state.event_id,
old_state.internal_metadata.stream_ordering,
)
is_host_in_room = await self._is_host_in_room(partial_state_before_join)

if old_membership in ["ban", "leave"] and action == "kick":
raise AuthError(403, "The target user is not in the room")
# if we are not in the room, we won't have the current state
if is_host_in_room:
# TODO: Refactor into dictionary of explicitly allowed transitions
# between old and new state, with specific error messages for some
# transitions and generic otherwise
old_state_id = partial_state_before_join.get(
(EventTypes.Member, target.to_string())
)

# we don't allow people to reject invites to the server notice
# room, but they can leave it once they are joined.
if (
old_membership == Membership.INVITE
and effective_membership_state == Membership.LEAVE
):
is_blocked = await self.store.is_server_notice_room(room_id)
if is_blocked:
if old_state_id:
old_state = await self.store.get_event(old_state_id, allow_none=True)
old_membership = (
old_state.content.get("membership") if old_state else None
)
if action == "unban" and old_membership != "ban":
raise SynapseError(
HTTPStatus.FORBIDDEN,
"You cannot reject this invite",
errcode=Codes.CANNOT_LEAVE_SERVER_NOTICE_ROOM,
403,
"Cannot unban user who was not banned"
" (membership=%s)" % old_membership,
errcode=Codes.BAD_STATE,
)
if old_membership == "ban" and action not in ["ban", "unban", "leave"]:
raise SynapseError(
403,
"Cannot %s user who was banned" % (action,),
errcode=Codes.BAD_STATE,
)
else:
if action == "kick":
raise AuthError(403, "The target user is not in the room")

is_host_in_room = await self._is_host_in_room(partial_state_before_join)
if old_state:
same_content = content == old_state.content
same_membership = old_membership == effective_membership_state
same_sender = requester.user.to_string() == old_state.sender
if same_sender and same_membership and same_content:
# duplicate event.
# we know it was persisted, so must have a stream ordering.
assert old_state.internal_metadata.stream_ordering
return (
old_state.event_id,
old_state.internal_metadata.stream_ordering,
)

if old_membership in ["ban", "leave"] and action == "kick":
raise AuthError(403, "The target user is not in the room")

# we don't allow people to reject invites to the server notice
# room, but they can leave it once they are joined.
if (
old_membership == Membership.INVITE
and effective_membership_state == Membership.LEAVE
):
is_blocked = await self.store.is_server_notice_room(room_id)
if is_blocked:
raise SynapseError(
HTTPStatus.FORBIDDEN,
"You cannot reject this invite",
errcode=Codes.CANNOT_LEAVE_SERVER_NOTICE_ROOM,
)
else:
if action == "kick":
raise AuthError(403, "The target user is not in the room")

if effective_membership_state == Membership.JOIN:
if requester.is_guest:
Expand Down