Delete stale non-e2e devices for users, take 3 (#15183)

This should help reduce the number of devices e.g. simple bots the repeatedly login rack up.

We only delete non-e2e devices as they should be safe to delete, whereas if we delete e2e devices for a user we may accidentally break their ability to receive e2e keys for a message.
This commit is contained in:
Erik Johnston 2023-03-29 12:07:14 +01:00 committed by GitHub
parent d0541e36c0
commit 78cdb72cd6
No known key found for this signature in database
GPG Key ID: 4AEE18F83AFDEB23
7 changed files with 134 additions and 7 deletions

1
changelog.d/15183.misc Normal file
View File

@ -0,0 +1 @@
Prune user's old devices on login if they have too many.

View File

@ -485,7 +485,7 @@ class DeviceHandler(DeviceWorkerHandler):
device_ids = [d for d in device_ids if d != except_device_id]
await self.delete_devices(user_id, device_ids)
async def delete_devices(self, user_id: str, device_ids: List[str]) -> None:
async def delete_devices(self, user_id: str, device_ids: StrCollection) -> None:
"""Delete several devices
Args:

View File

@ -16,7 +16,7 @@
"""Contains functions for registering clients."""
import logging
from typing import TYPE_CHECKING, Iterable, List, Optional, Tuple
from typing import TYPE_CHECKING, Iterable, List, Optional, Set, Tuple
from prometheus_client import Counter
from typing_extensions import TypedDict
@ -40,6 +40,7 @@ from synapse.appservice import ApplicationService
from synapse.config.server import is_threepid_reserved
from synapse.handlers.device import DeviceHandler
from synapse.http.servlet import assert_params_in_dict
from synapse.metrics.background_process_metrics import run_as_background_process
from synapse.replication.http.login import RegisterDeviceReplicationServlet
from synapse.replication.http.register import (
ReplicationPostRegisterActionsServlet,
@ -48,6 +49,7 @@ from synapse.replication.http.register import (
from synapse.spam_checker_api import RegistrationBehaviour
from synapse.types import RoomAlias, UserID, create_requester
from synapse.types.state import StateFilter
from synapse.util.iterutils import batch_iter
if TYPE_CHECKING:
from synapse.server import HomeServer
@ -110,6 +112,10 @@ class RegistrationHandler:
self._server_notices_mxid = hs.config.servernotices.server_notices_mxid
self._server_name = hs.hostname
# The set of users that we're currently pruning devices for. Ensures
# that we don't have two such jobs for the same user running at once.
self._currently_pruning_devices_for_users: Set[str] = set()
self.spam_checker = hs.get_spam_checker()
if hs.config.worker.worker_app:
@ -121,7 +127,10 @@ class RegistrationHandler:
ReplicationPostRegisterActionsServlet.make_client(hs)
)
else:
self.device_handler = hs.get_device_handler()
device_handler = hs.get_device_handler()
assert isinstance(device_handler, DeviceHandler)
self.device_handler = device_handler
self._register_device_client = self.register_device_inner
self.pusher_pool = hs.get_pusherpool()
@ -851,6 +860,9 @@ class RegistrationHandler:
# This can only run on the main process.
assert isinstance(self.device_handler, DeviceHandler)
# Prune the user's device list if they already have a lot of devices.
await self._maybe_prune_too_many_devices(user_id)
registered_device_id = await self.device_handler.check_device_registered(
user_id,
device_id,
@ -919,6 +931,40 @@ class RegistrationHandler:
"refresh_token": refresh_token,
}
async def _maybe_prune_too_many_devices(self, user_id: str) -> None:
"""Delete any excess old devices this user may have."""
if user_id in self._currently_pruning_devices_for_users:
return
# We also cap the number of users whose devices we prune at the same
# time, to avoid performance problems.
if len(self._currently_pruning_devices_for_users) > 5:
return
device_ids = await self.store.check_too_many_devices_for_user(user_id)
if not device_ids:
return
# Now spawn a background loop that deletes said devices.
async def _prune_too_many_devices_loop() -> None:
if user_id in self._currently_pruning_devices_for_users:
return
self._currently_pruning_devices_for_users.add(user_id)
try:
for batch in batch_iter(device_ids, 10):
await self.device_handler.delete_devices(user_id, batch)
await self.clock.sleep(60)
finally:
self._currently_pruning_devices_for_users.discard(user_id)
run_as_background_process(
"_prune_too_many_devices_loop", _prune_too_many_devices_loop
)
async def post_registration_actions(
self, user_id: str, auth_result: dict, access_token: Optional[str]
) -> None:

View File

@ -1599,6 +1599,73 @@ class DeviceBackgroundUpdateStore(SQLBaseStore):
return rows
async def check_too_many_devices_for_user(self, user_id: str) -> List[str]:
"""Check if the user has a lot of devices, and if so return the set of
devices we can prune.
This does *not* return hidden devices or devices with E2E keys.
"""
num_devices = await self.db_pool.simple_select_one_onecol(
table="devices",
keyvalues={"user_id": user_id, "hidden": False},
retcol="COALESCE(COUNT(*), 0)",
desc="count_devices",
)
# We let users have up to ten devices without pruning.
if num_devices <= 10:
return []
# We always prune devices not seen in the last 14 days...
max_last_seen = self._clock.time_msec() - 14 * 24 * 60 * 60 * 1000
# ... but we also cap the maximum number of devices the user can have to
# 50.
if num_devices > 50:
# Choose a last seen that ensures we keep at most 50 devices.
sql = """
SELECT last_seen FROM devices
LEFT JOIN e2e_device_keys_json USING (user_id, device_id)
WHERE
user_id = ?
AND NOT hidden
AND last_seen IS NOT NULL
AND key_json IS NULL
ORDER BY last_seen DESC
LIMIT 1
OFFSET 50
"""
rows = await self.db_pool.execute(
"check_too_many_devices_for_user_last_seen", None, sql, (user_id,)
)
if rows:
max_last_seen = max(rows[0][0], max_last_seen)
# Fetch the devices to delete.
sql = """
SELECT DISTINCT device_id FROM devices
LEFT JOIN e2e_device_keys_json USING (user_id, device_id)
WHERE
user_id = ?
AND NOT hidden
AND last_seen < ?
AND key_json IS NULL
ORDER BY last_seen
"""
def check_too_many_devices_for_user_txn(
txn: LoggingTransaction,
) -> List[str]:
txn.execute(sql, (user_id, max_last_seen))
return [device_id for device_id, in txn]
return await self.db_pool.runInteraction(
"check_too_many_devices_for_user",
check_too_many_devices_for_user_txn,
)
class DeviceStore(DeviceWorkerStore, DeviceBackgroundUpdateStore):
# Because we have write access, this will be a StreamIdGenerator
@ -1657,6 +1724,7 @@ class DeviceStore(DeviceWorkerStore, DeviceBackgroundUpdateStore):
values={},
insertion_values={
"display_name": initial_device_display_name,
"last_seen": self._clock.time_msec(),
"hidden": False,
},
desc="store_device",
@ -1702,7 +1770,15 @@ class DeviceStore(DeviceWorkerStore, DeviceBackgroundUpdateStore):
)
raise StoreError(500, "Problem storing device.")
async def delete_devices(self, user_id: str, device_ids: List[str]) -> None:
@cached(max_entries=0)
async def delete_device(self, user_id: str, device_id: str) -> None:
raise NotImplementedError()
# Note: sometimes deleting rows out of `device_inbox` can take a long time,
# so we use a cache so that we deduplicate in flight requests to delete
# devices.
@cachedList(cached_method_name="delete_device", list_name="device_ids")
async def delete_devices(self, user_id: str, device_ids: Collection[str]) -> dict:
"""Deletes several devices.
Args:
@ -1739,6 +1815,8 @@ class DeviceStore(DeviceWorkerStore, DeviceBackgroundUpdateStore):
for device_id in device_ids:
self.device_id_exists_cache.invalidate((user_id, device_id))
return {}
async def update_device(
self, user_id: str, device_id: str, new_display_name: Optional[str] = None
) -> None:

View File

@ -272,7 +272,7 @@ class ExfiltrateData(unittest.HomeserverTestCase):
self.assertIn("device_id", args[0][0])
self.assertIsNone(args[0][0]["display_name"])
self.assertIsNone(args[0][0]["last_seen_user_agent"])
self.assertIsNone(args[0][0]["last_seen_ts"])
self.assertEqual(args[0][0]["last_seen_ts"], 600)
self.assertIsNone(args[0][0]["last_seen_ip"])
def test_connections(self) -> None:

View File

@ -115,7 +115,7 @@ class DeviceTestCase(unittest.HomeserverTestCase):
"device_id": "xyz",
"display_name": "display 0",
"last_seen_ip": None,
"last_seen_ts": None,
"last_seen_ts": 1000000,
},
device_map["xyz"],
)

View File

@ -170,6 +170,8 @@ class ClientIpStoreTestCase(unittest.HomeserverTestCase):
)
)
last_seen = self.clock.time_msec()
if after_persisting:
# Trigger the storage loop
self.reactor.advance(10)
@ -190,7 +192,7 @@ class ClientIpStoreTestCase(unittest.HomeserverTestCase):
"device_id": device_id,
"ip": None,
"user_agent": None,
"last_seen": None,
"last_seen": last_seen,
},
],
)