@ -14,7 +14,17 @@
# limitations under the License.
import logging
from enum import Enum , auto
from typing import Collection , Dict , FrozenSet , List , Optional , Tuple
from typing import (
Collection ,
Dict ,
FrozenSet ,
List ,
Mapping ,
Optional ,
Sequence ,
Set ,
Tuple ,
)
import attr
from typing_extensions import Final
@ -565,29 +575,43 @@ async def filter_events_for_server(
storage : StorageControllers ,
target_server_name : str ,
local_server_name : str ,
events : List [ EventBase ] ,
redact : bool = True ,
check_history_visibility_only : bool = False ,
events : Sequence [ EventBase ] ,
* ,
redact : bool ,
filter_out_erased_senders : bool ,
filter_out_remote_partial_state_events : bool ,
) - > List [ EventBase ] :
""" Filter a list of events based on whether given server is allowed to
""" Filter a list of events based on whether the target server is allowed to
see them .
For a fully stated room , the target server is allowed to see an event E if :
- the state at E has world readable or shared history vis , OR
- the state at E says that the target server is in the room .
For a partially stated room , the target server is allowed to see E if :
- E was created by this homeserver , AND :
- the partial state at E has world readable or shared history vis , OR
- the partial state at E says that the target server is in the room .
TODO : state before or state after ?
Args :
storage
server_name
target_server_name
local_server_name
events
redact : Whether to return a redacted version of the event , or
to filter them out entirely .
check_history_visibility_only : Whether to only check the
history visibility , rather than things like if the sender has been
redact : Controls what to do with events which have been filtered out .
If True , include their redacted forms ; if False , omit them entirely .
filter_out_erased_senders : If true , also filter out events whose sender has been
erased . This is used e . g . during pagination to decide whether to
backfill or not .
filter_out_remote_partial_state_events : If True , also filter out events in
partial state rooms created by other homeservers .
Returns
The filtered events .
"""
def is_sender_erased ( event : EventBase , erased_senders : Dict [ str , bool ] ) - > bool :
def is_sender_erased ( event : EventBase , erased_senders : Mapping [ str , bool ] ) - > bool :
if erased_senders and erased_senders [ event . sender ] :
logger . info ( " Sender of %s has been erased, redacting " , event . event_id )
return True
@ -616,7 +640,7 @@ async def filter_events_for_server(
# server has no users in the room: redact
return False
if not check_history_visibility_only :
if filter_out_erased_senders :
erased_senders = await storage . main . are_users_erased ( e . sender for e in events )
else :
# We don't want to check whether users are erased, which is equivalent
@ -631,15 +655,15 @@ async def filter_events_for_server(
# otherwise a room could be fully joined after we retrieve those, which would then bypass
# this check but would base the filtering on an outdated view of the membership events.
partial_state_invisible_events = set ( )
if not check_history_visibility_only :
partial_state_invisible_event_id s : Set [ str ] = set ( )
if filter_out_remote_partial_state_events :
for e in events :
sender_domain = get_domain_from_id ( e . sender )
if (
sender_domain != local_server_name
and await storage . main . is_partial_state_room ( e . room_id )
) :
partial_state_invisible_events . add ( e )
partial_state_invisible_event_id s . add ( e . event_id )
# Let's check to see if all the events have a history visibility
# of "shared" or "world_readable". If that's the case then we don't
@ -658,17 +682,20 @@ async def filter_events_for_server(
target_server_name ,
)
to_return = [ ]
for e in events :
def include_event_in_output ( e : EventBase ) - > bool :
erased = is_sender_erased ( e , erased_senders )
visible = check_event_is_visible (
event_to_history_vis [ e . event_id ] , event_to_memberships . get ( e . event_id , { } )
)
if e in partial_state_invisible_events :
if e . event_id in partial_state_invisible_event_id s :
visible = False
if visible and not erased :
return visible and not erased
to_return = [ ]
for e in events :
if include_event_in_output ( e ) :
to_return . append ( e )
elif redact :
to_return . append ( prune_event ( e ) )
David Robertson
2 years ago
committed by