Move Spam Checker callbacks to a dedicated file (#15453)

1 files changed, 0 insertions, 822 deletions

diff --git a/synapse/events/spamcheck.py b/synapse/events/spamcheck.py
deleted file mode 100644
index 765c15bb51..0000000000
--- a/synapse/events/spamcheck.py
+++ /dev/null
@@ -1,822 +0,0 @@
-# Copyright 2017 New Vector Ltd
-# Copyright 2019 The Matrix.org Foundation C.I.C.
-#
-# Licensed under the Apache License, Version 2.0 (the "License");
-# you may not use this file except in compliance with the License.
-# You may obtain a copy of the License at
-#
-#     http://www.apache.org/licenses/LICENSE-2.0
-#
-# Unless required by applicable law or agreed to in writing, software
-# distributed under the License is distributed on an "AS IS" BASIS,
-# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-# See the License for the specific language governing permissions and
-# limitations under the License.
-
-import inspect
-import logging
-from typing import (
-    TYPE_CHECKING,
-    Any,
-    Awaitable,
-    Callable,
-    Collection,
-    List,
-    Optional,
-    Tuple,
-    Union,
-)
-
-# `Literal` appears with Python 3.8.
-from typing_extensions import Literal
-
-import synapse
-from synapse.api.errors import Codes
-from synapse.logging.opentracing import trace
-from synapse.media._base import FileInfo
-from synapse.media.media_storage import ReadableFileWrapper
-from synapse.spam_checker_api import RegistrationBehaviour
-from synapse.types import JsonDict, RoomAlias, UserProfile
-from synapse.util.async_helpers import delay_cancellation, maybe_awaitable
-from synapse.util.metrics import Measure
-
-if TYPE_CHECKING:
-    import synapse.events
-    import synapse.server
-
-logger = logging.getLogger(__name__)
-
-CHECK_EVENT_FOR_SPAM_CALLBACK = Callable[
-    ["synapse.events.EventBase"],
-    Awaitable[
-        Union[
-            str,
-            Codes,
-            # Highly experimental, not officially part of the spamchecker API, may
-            # disappear without warning depending on the results of ongoing
-            # experiments.
-            # Use this to return additional information as part of an error.
-            Tuple[Codes, JsonDict],
-            # Deprecated
-            bool,
-        ]
-    ],
-]
-SHOULD_DROP_FEDERATED_EVENT_CALLBACK = Callable[
-    ["synapse.events.EventBase"],
-    Awaitable[Union[bool, str]],
-]
-USER_MAY_JOIN_ROOM_CALLBACK = Callable[
-    [str, str, bool],
-    Awaitable[
-        Union[
-            Literal["NOT_SPAM"],
-            Codes,
-            # Highly experimental, not officially part of the spamchecker API, may
-            # disappear without warning depending on the results of ongoing
-            # experiments.
-            # Use this to return additional information as part of an error.
-            Tuple[Codes, JsonDict],
-            # Deprecated
-            bool,
-        ]
-    ],
-]
-USER_MAY_INVITE_CALLBACK = Callable[
-    [str, str, str],
-    Awaitable[
-        Union[
-            Literal["NOT_SPAM"],
-            Codes,
-            # Highly experimental, not officially part of the spamchecker API, may
-            # disappear without warning depending on the results of ongoing
-            # experiments.
-            # Use this to return additional information as part of an error.
-            Tuple[Codes, JsonDict],
-            # Deprecated
-            bool,
-        ]
-    ],
-]
-USER_MAY_SEND_3PID_INVITE_CALLBACK = Callable[
-    [str, str, str, str],
-    Awaitable[
-        Union[
-            Literal["NOT_SPAM"],
-            Codes,
-            # Highly experimental, not officially part of the spamchecker API, may
-            # disappear without warning depending on the results of ongoing
-            # experiments.
-            # Use this to return additional information as part of an error.
-            Tuple[Codes, JsonDict],
-            # Deprecated
-            bool,
-        ]
-    ],
-]
-USER_MAY_CREATE_ROOM_CALLBACK = Callable[
-    [str],
-    Awaitable[
-        Union[
-            Literal["NOT_SPAM"],
-            Codes,
-            # Highly experimental, not officially part of the spamchecker API, may
-            # disappear without warning depending on the results of ongoing
-            # experiments.
-            # Use this to return additional information as part of an error.
-            Tuple[Codes, JsonDict],
-            # Deprecated
-            bool,
-        ]
-    ],
-]
-USER_MAY_CREATE_ROOM_ALIAS_CALLBACK = Callable[
-    [str, RoomAlias],
-    Awaitable[
-        Union[
-            Literal["NOT_SPAM"],
-            Codes,
-            # Highly experimental, not officially part of the spamchecker API, may
-            # disappear without warning depending on the results of ongoing
-            # experiments.
-            # Use this to return additional information as part of an error.
-            Tuple[Codes, JsonDict],
-            # Deprecated
-            bool,
-        ]
-    ],
-]
-USER_MAY_PUBLISH_ROOM_CALLBACK = Callable[
-    [str, str],
-    Awaitable[
-        Union[
-            Literal["NOT_SPAM"],
-            Codes,
-            # Highly experimental, not officially part of the spamchecker API, may
-            # disappear without warning depending on the results of ongoing
-            # experiments.
-            # Use this to return additional information as part of an error.
-            Tuple[Codes, JsonDict],
-            # Deprecated
-            bool,
-        ]
-    ],
-]
-CHECK_USERNAME_FOR_SPAM_CALLBACK = Callable[[UserProfile], Awaitable[bool]]
-LEGACY_CHECK_REGISTRATION_FOR_SPAM_CALLBACK = Callable[
-    [
-        Optional[dict],
-        Optional[str],
-        Collection[Tuple[str, str]],
-    ],
-    Awaitable[RegistrationBehaviour],
-]
-CHECK_REGISTRATION_FOR_SPAM_CALLBACK = Callable[
-    [
-        Optional[dict],
-        Optional[str],
-        Collection[Tuple[str, str]],
-        Optional[str],
-    ],
-    Awaitable[RegistrationBehaviour],
-]
-CHECK_MEDIA_FILE_FOR_SPAM_CALLBACK = Callable[
-    [ReadableFileWrapper, FileInfo],
-    Awaitable[
-        Union[
-            Literal["NOT_SPAM"],
-            Codes,
-            # Highly experimental, not officially part of the spamchecker API, may
-            # disappear without warning depending on the results of ongoing
-            # experiments.
-            # Use this to return additional information as part of an error.
-            Tuple[Codes, JsonDict],
-            # Deprecated
-            bool,
-        ]
-    ],
-]
-
-
-def load_legacy_spam_checkers(hs: "synapse.server.HomeServer") -> None:
-    """Wrapper that loads spam checkers configured using the old configuration, and
-    registers the spam checker hooks they implement.
-    """
-    spam_checkers: List[Any] = []
-    api = hs.get_module_api()
-    for module, config in hs.config.spamchecker.spam_checkers:
-        # Older spam checkers don't accept the `api` argument, so we
-        # try and detect support.
-        spam_args = inspect.getfullargspec(module)
-        if "api" in spam_args.args:
-            spam_checkers.append(module(config=config, api=api))
-        else:
-            spam_checkers.append(module(config=config))
-
-    # The known spam checker hooks. If a spam checker module implements a method
-    # which name appears in this set, we'll want to register it.
-    spam_checker_methods = {
-        "check_event_for_spam",
-        "user_may_invite",
-        "user_may_create_room",
-        "user_may_create_room_alias",
-        "user_may_publish_room",
-        "check_username_for_spam",
-        "check_registration_for_spam",
-        "check_media_file_for_spam",
-    }
-
-    for spam_checker in spam_checkers:
-        # Methods on legacy spam checkers might not be async, so we wrap them around a
-        # wrapper that will call maybe_awaitable on the result.
-        def async_wrapper(f: Optional[Callable]) -> Optional[Callable[..., Awaitable]]:
-            # f might be None if the callback isn't implemented by the module. In this
-            # case we don't want to register a callback at all so we return None.
-            if f is None:
-                return None
-
-            wrapped_func = f
-
-            if f.__name__ == "check_registration_for_spam":
-                checker_args = inspect.signature(f)
-                if len(checker_args.parameters) == 3:
-                    # Backwards compatibility; some modules might implement a hook that
-                    # doesn't expect a 4th argument. In this case, wrap it in a function
-                    # that gives it only 3 arguments and drops the auth_provider_id on
-                    # the floor.
-                    def wrapper(
-                        email_threepid: Optional[dict],
-                        username: Optional[str],
-                        request_info: Collection[Tuple[str, str]],
-                        auth_provider_id: Optional[str],
-                    ) -> Union[Awaitable[RegistrationBehaviour], RegistrationBehaviour]:
-                        # Assertion required because mypy can't prove we won't
-                        # change `f` back to `None`. See
-                        # https://mypy.readthedocs.io/en/latest/common_issues.html#narrowing-and-inner-functions
-                        assert f is not None
-
-                        return f(
-                            email_threepid,
-                            username,
-                            request_info,
-                        )
-
-                    wrapped_func = wrapper
-                elif len(checker_args.parameters) != 4:
-                    raise RuntimeError(
-                        "Bad signature for callback check_registration_for_spam",
-                    )
-
-            def run(*args: Any, **kwargs: Any) -> Awaitable:
-                # Assertion required because mypy can't prove we won't change `f`
-                # back to `None`. See
-                # https://mypy.readthedocs.io/en/latest/common_issues.html#narrowing-and-inner-functions
-                assert wrapped_func is not None
-
-                return maybe_awaitable(wrapped_func(*args, **kwargs))
-
-            return run
-
-        # Register the hooks through the module API.
-        hooks = {
-            hook: async_wrapper(getattr(spam_checker, hook, None))
-            for hook in spam_checker_methods
-        }
-
-        api.register_spam_checker_callbacks(**hooks)
-
-
-class SpamChecker:
-    NOT_SPAM: Literal["NOT_SPAM"] = "NOT_SPAM"
-
-    def __init__(self, hs: "synapse.server.HomeServer") -> None:
-        self.hs = hs
-        self.clock = hs.get_clock()
-
-        self._check_event_for_spam_callbacks: List[CHECK_EVENT_FOR_SPAM_CALLBACK] = []
-        self._should_drop_federated_event_callbacks: List[
-            SHOULD_DROP_FEDERATED_EVENT_CALLBACK
-        ] = []
-        self._user_may_join_room_callbacks: List[USER_MAY_JOIN_ROOM_CALLBACK] = []
-        self._user_may_invite_callbacks: List[USER_MAY_INVITE_CALLBACK] = []
-        self._user_may_send_3pid_invite_callbacks: List[
-            USER_MAY_SEND_3PID_INVITE_CALLBACK
-        ] = []
-        self._user_may_create_room_callbacks: List[USER_MAY_CREATE_ROOM_CALLBACK] = []
-        self._user_may_create_room_alias_callbacks: List[
-            USER_MAY_CREATE_ROOM_ALIAS_CALLBACK
-        ] = []
-        self._user_may_publish_room_callbacks: List[USER_MAY_PUBLISH_ROOM_CALLBACK] = []
-        self._check_username_for_spam_callbacks: List[
-            CHECK_USERNAME_FOR_SPAM_CALLBACK
-        ] = []
-        self._check_registration_for_spam_callbacks: List[
-            CHECK_REGISTRATION_FOR_SPAM_CALLBACK
-        ] = []
-        self._check_media_file_for_spam_callbacks: List[
-            CHECK_MEDIA_FILE_FOR_SPAM_CALLBACK
-        ] = []
-
-    def register_callbacks(
-        self,
-        check_event_for_spam: Optional[CHECK_EVENT_FOR_SPAM_CALLBACK] = None,
-        should_drop_federated_event: Optional[
-            SHOULD_DROP_FEDERATED_EVENT_CALLBACK
-        ] = None,
-        user_may_join_room: Optional[USER_MAY_JOIN_ROOM_CALLBACK] = None,
-        user_may_invite: Optional[USER_MAY_INVITE_CALLBACK] = None,
-        user_may_send_3pid_invite: Optional[USER_MAY_SEND_3PID_INVITE_CALLBACK] = None,
-        user_may_create_room: Optional[USER_MAY_CREATE_ROOM_CALLBACK] = None,
-        user_may_create_room_alias: Optional[
-            USER_MAY_CREATE_ROOM_ALIAS_CALLBACK
-        ] = None,
-        user_may_publish_room: Optional[USER_MAY_PUBLISH_ROOM_CALLBACK] = None,
-        check_username_for_spam: Optional[CHECK_USERNAME_FOR_SPAM_CALLBACK] = None,
-        check_registration_for_spam: Optional[
-            CHECK_REGISTRATION_FOR_SPAM_CALLBACK
-        ] = None,
-        check_media_file_for_spam: Optional[CHECK_MEDIA_FILE_FOR_SPAM_CALLBACK] = None,
-    ) -> None:
-        """Register callbacks from module for each hook."""
-        if check_event_for_spam is not None:
-            self._check_event_for_spam_callbacks.append(check_event_for_spam)
-
-        if should_drop_federated_event is not None:
-            self._should_drop_federated_event_callbacks.append(
-                should_drop_federated_event
-            )
-
-        if user_may_join_room is not None:
-            self._user_may_join_room_callbacks.append(user_may_join_room)
-
-        if user_may_invite is not None:
-            self._user_may_invite_callbacks.append(user_may_invite)
-
-        if user_may_send_3pid_invite is not None:
-            self._user_may_send_3pid_invite_callbacks.append(
-                user_may_send_3pid_invite,
-            )
-
-        if user_may_create_room is not None:
-            self._user_may_create_room_callbacks.append(user_may_create_room)
-
-        if user_may_create_room_alias is not None:
-            self._user_may_create_room_alias_callbacks.append(
-                user_may_create_room_alias,
-            )
-
-        if user_may_publish_room is not None:
-            self._user_may_publish_room_callbacks.append(user_may_publish_room)
-
-        if check_username_for_spam is not None:
-            self._check_username_for_spam_callbacks.append(check_username_for_spam)
-
-        if check_registration_for_spam is not None:
-            self._check_registration_for_spam_callbacks.append(
-                check_registration_for_spam,
-            )
-
-        if check_media_file_for_spam is not None:
-            self._check_media_file_for_spam_callbacks.append(check_media_file_for_spam)
-
-    @trace
-    async def check_event_for_spam(
-        self, event: "synapse.events.EventBase"
-    ) -> Union[Tuple[Codes, JsonDict], str]:
-        """Checks if a given event is considered "spammy" by this server.
-
-        If the server considers an event spammy, then it will be rejected if
-        sent by a local user. If it is sent by a user on another server, the
-        event is soft-failed.
-
-        Args:
-            event: the event to be checked
-
-        Returns:
-            - `NOT_SPAM` if the event is considered good (non-spammy) and should be let
-                through. Other spamcheck filters may still reject it.
-            - A `Code` if the event is considered spammy and is rejected with a specific
-                error message/code.
-            - A string that isn't `NOT_SPAM` if the event is considered spammy and the
-                string should be used as the client-facing error message. This usage is
-                generally discouraged as it doesn't support internationalization.
-        """
-        for callback in self._check_event_for_spam_callbacks:
-            with Measure(
-                self.clock, "{}.{}".format(callback.__module__, callback.__qualname__)
-            ):
-                res = await delay_cancellation(callback(event))
-                if res is False or res == self.NOT_SPAM:
-                    # This spam-checker accepts the event.
-                    # Other spam-checkers may reject it, though.
-                    continue
-                elif res is True:
-                    # This spam-checker rejects the event with deprecated
-                    # return value `True`
-                    return synapse.api.errors.Codes.FORBIDDEN, {}
-                elif (
-                    isinstance(res, tuple)
-                    and len(res) == 2
-                    and isinstance(res[0], synapse.api.errors.Codes)
-                    and isinstance(res[1], dict)
-                ):
-                    return res
-                elif isinstance(res, synapse.api.errors.Codes):
-                    return res, {}
-                elif not isinstance(res, str):
-                    # mypy complains that we can't reach this code because of the
-                    # return type in CHECK_EVENT_FOR_SPAM_CALLBACK, but we don't know
-                    # for sure that the module actually returns it.
-                    logger.warning(
-                        "Module returned invalid value, rejecting message as spam"
-                    )
-                    res = "This message has been rejected as probable spam"
-                else:
-                    # The module rejected the event either with a `Codes`
-                    # or some other `str`. In either case, we stop here.
-                    pass
-
-                return res
-
-        # No spam-checker has rejected the event, let it pass.
-        return self.NOT_SPAM
-
-    async def should_drop_federated_event(
-        self, event: "synapse.events.EventBase"
-    ) -> Union[bool, str]:
-        """Checks if a given federated event is considered "spammy" by this
-        server.
-
-        If the server considers an event spammy, it will be silently dropped,
-        and in doing so will split-brain our view of the room's DAG.
-
-        Args:
-            event: the event to be checked
-
-        Returns:
-            True if the event should be silently dropped
-        """
-        for callback in self._should_drop_federated_event_callbacks:
-            with Measure(
-                self.clock, "{}.{}".format(callback.__module__, callback.__qualname__)
-            ):
-                res: Union[bool, str] = await delay_cancellation(callback(event))
-            if res:
-                return res
-
-        return False
-
-    async def user_may_join_room(
-        self, user_id: str, room_id: str, is_invited: bool
-    ) -> Union[Tuple[Codes, JsonDict], Literal["NOT_SPAM"]]:
-        """Checks if a given users is allowed to join a room.
-        Not called when a user creates a room.
-
-        Args:
-            userid: The ID of the user wanting to join the room
-            room_id: The ID of the room the user wants to join
-            is_invited: Whether the user is invited into the room
-
-        Returns:
-            NOT_SPAM if the operation is permitted, [Codes, Dict] otherwise.
-        """
-        for callback in self._user_may_join_room_callbacks:
-            with Measure(
-                self.clock, "{}.{}".format(callback.__module__, callback.__qualname__)
-            ):
-                res = await delay_cancellation(callback(user_id, room_id, is_invited))
-                # Normalize return values to `Codes` or `"NOT_SPAM"`.
-                if res is True or res is self.NOT_SPAM:
-                    continue
-                elif res is False:
-                    return synapse.api.errors.Codes.FORBIDDEN, {}
-                elif isinstance(res, synapse.api.errors.Codes):
-                    return res, {}
-                elif (
-                    isinstance(res, tuple)
-                    and len(res) == 2
-                    and isinstance(res[0], synapse.api.errors.Codes)
-                    and isinstance(res[1], dict)
-                ):
-                    return res
-                else:
-                    logger.warning(
-                        "Module returned invalid value, rejecting join as spam"
-                    )
-                    return synapse.api.errors.Codes.FORBIDDEN, {}
-
-        # No spam-checker has rejected the request, let it pass.
-        return self.NOT_SPAM
-
-    async def user_may_invite(
-        self, inviter_userid: str, invitee_userid: str, room_id: str
-    ) -> Union[Tuple[Codes, dict], Literal["NOT_SPAM"]]:
-        """Checks if a given user may send an invite
-
-        Args:
-            inviter_userid: The user ID of the sender of the invitation
-            invitee_userid: The user ID targeted in the invitation
-            room_id: The room ID
-
-        Returns:
-            NOT_SPAM if the operation is permitted, Codes otherwise.
-        """
-        for callback in self._user_may_invite_callbacks:
-            with Measure(
-                self.clock, "{}.{}".format(callback.__module__, callback.__qualname__)
-            ):
-                res = await delay_cancellation(
-                    callback(inviter_userid, invitee_userid, room_id)
-                )
-                # Normalize return values to `Codes` or `"NOT_SPAM"`.
-                if res is True or res is self.NOT_SPAM:
-                    continue
-                elif res is False:
-                    return synapse.api.errors.Codes.FORBIDDEN, {}
-                elif isinstance(res, synapse.api.errors.Codes):
-                    return res, {}
-                elif (
-                    isinstance(res, tuple)
-                    and len(res) == 2
-                    and isinstance(res[0], synapse.api.errors.Codes)
-                    and isinstance(res[1], dict)
-                ):
-                    return res
-                else:
-                    logger.warning(
-                        "Module returned invalid value, rejecting invite as spam"
-                    )
-                    return synapse.api.errors.Codes.FORBIDDEN, {}
-
-        # No spam-checker has rejected the request, let it pass.
-        return self.NOT_SPAM
-
-    async def user_may_send_3pid_invite(
-        self, inviter_userid: str, medium: str, address: str, room_id: str
-    ) -> Union[Tuple[Codes, dict], Literal["NOT_SPAM"]]:
-        """Checks if a given user may invite a given threepid into the room
-
-        Note that if the threepid is already associated with a Matrix user ID, Synapse
-        will call user_may_invite with said user ID instead.
-
-        Args:
-            inviter_userid: The user ID of the sender of the invitation
-            medium: The 3PID's medium (e.g. "email")
-            address: The 3PID's address (e.g. "alice@example.com")
-            room_id: The room ID
-
-        Returns:
-            NOT_SPAM if the operation is permitted, Codes otherwise.
-        """
-        for callback in self._user_may_send_3pid_invite_callbacks:
-            with Measure(
-                self.clock, "{}.{}".format(callback.__module__, callback.__qualname__)
-            ):
-                res = await delay_cancellation(
-                    callback(inviter_userid, medium, address, room_id)
-                )
-                # Normalize return values to `Codes` or `"NOT_SPAM"`.
-                if res is True or res is self.NOT_SPAM:
-                    continue
-                elif res is False:
-                    return synapse.api.errors.Codes.FORBIDDEN, {}
-                elif isinstance(res, synapse.api.errors.Codes):
-                    return res, {}
-                elif (
-                    isinstance(res, tuple)
-                    and len(res) == 2
-                    and isinstance(res[0], synapse.api.errors.Codes)
-                    and isinstance(res[1], dict)
-                ):
-                    return res
-                else:
-                    logger.warning(
-                        "Module returned invalid value, rejecting 3pid invite as spam"
-                    )
-                    return synapse.api.errors.Codes.FORBIDDEN, {}
-
-        return self.NOT_SPAM
-
-    async def user_may_create_room(
-        self, userid: str
-    ) -> Union[Tuple[Codes, dict], Literal["NOT_SPAM"]]:
-        """Checks if a given user may create a room
-
-        Args:
-            userid: The ID of the user attempting to create a room
-        """
-        for callback in self._user_may_create_room_callbacks:
-            with Measure(
-                self.clock, "{}.{}".format(callback.__module__, callback.__qualname__)
-            ):
-                res = await delay_cancellation(callback(userid))
-                if res is True or res is self.NOT_SPAM:
-                    continue
-                elif res is False:
-                    return synapse.api.errors.Codes.FORBIDDEN, {}
-                elif isinstance(res, synapse.api.errors.Codes):
-                    return res, {}
-                elif (
-                    isinstance(res, tuple)
-                    and len(res) == 2
-                    and isinstance(res[0], synapse.api.errors.Codes)
-                    and isinstance(res[1], dict)
-                ):
-                    return res
-                else:
-                    logger.warning(
-                        "Module returned invalid value, rejecting room creation as spam"
-                    )
-                    return synapse.api.errors.Codes.FORBIDDEN, {}
-
-        return self.NOT_SPAM
-
-    async def user_may_create_room_alias(
-        self, userid: str, room_alias: RoomAlias
-    ) -> Union[Tuple[Codes, dict], Literal["NOT_SPAM"]]:
-        """Checks if a given user may create a room alias
-
-        Args:
-            userid: The ID of the user attempting to create a room alias
-            room_alias: The alias to be created
-
-        """
-        for callback in self._user_may_create_room_alias_callbacks:
-            with Measure(
-                self.clock, "{}.{}".format(callback.__module__, callback.__qualname__)
-            ):
-                res = await delay_cancellation(callback(userid, room_alias))
-                if res is True or res is self.NOT_SPAM:
-                    continue
-                elif res is False:
-                    return synapse.api.errors.Codes.FORBIDDEN, {}
-                elif isinstance(res, synapse.api.errors.Codes):
-                    return res, {}
-                elif (
-                    isinstance(res, tuple)
-                    and len(res) == 2
-                    and isinstance(res[0], synapse.api.errors.Codes)
-                    and isinstance(res[1], dict)
-                ):
-                    return res
-                else:
-                    logger.warning(
-                        "Module returned invalid value, rejecting room create as spam"
-                    )
-                    return synapse.api.errors.Codes.FORBIDDEN, {}
-
-        return self.NOT_SPAM
-
-    async def user_may_publish_room(
-        self, userid: str, room_id: str
-    ) -> Union[Tuple[Codes, dict], Literal["NOT_SPAM"]]:
-        """Checks if a given user may publish a room to the directory
-
-        Args:
-            userid: The user ID attempting to publish the room
-            room_id: The ID of the room that would be published
-        """
-        for callback in self._user_may_publish_room_callbacks:
-            with Measure(
-                self.clock, "{}.{}".format(callback.__module__, callback.__qualname__)
-            ):
-                res = await delay_cancellation(callback(userid, room_id))
-                if res is True or res is self.NOT_SPAM:
-                    continue
-                elif res is False:
-                    return synapse.api.errors.Codes.FORBIDDEN, {}
-                elif isinstance(res, synapse.api.errors.Codes):
-                    return res, {}
-                elif (
-                    isinstance(res, tuple)
-                    and len(res) == 2
-                    and isinstance(res[0], synapse.api.errors.Codes)
-                    and isinstance(res[1], dict)
-                ):
-                    return res
-                else:
-                    logger.warning(
-                        "Module returned invalid value, rejecting room publication as spam"
-                    )
-                    return synapse.api.errors.Codes.FORBIDDEN, {}
-
-        return self.NOT_SPAM
-
-    async def check_username_for_spam(self, user_profile: UserProfile) -> bool:
-        """Checks if a user ID or display name are considered "spammy" by this server.
-
-        If the server considers a username spammy, then it will not be included in
-        user directory results.
-
-        Args:
-            user_profile: The user information to check, it contains the keys:
-                * user_id
-                * display_name
-                * avatar_url
-
-        Returns:
-            True if the user is spammy.
-        """
-        for callback in self._check_username_for_spam_callbacks:
-            with Measure(
-                self.clock, "{}.{}".format(callback.__module__, callback.__qualname__)
-            ):
-                # Make a copy of the user profile object to ensure the spam checker cannot
-                # modify it.
-                res = await delay_cancellation(callback(user_profile.copy()))
-            if res:
-                return True
-
-        return False
-
-    async def check_registration_for_spam(
-        self,
-        email_threepid: Optional[dict],
-        username: Optional[str],
-        request_info: Collection[Tuple[str, str]],
-        auth_provider_id: Optional[str] = None,
-    ) -> RegistrationBehaviour:
-        """Checks if we should allow the given registration request.
-
-        Args:
-            email_threepid: The email threepid used for registering, if any
-            username: The request user name, if any
-            request_info: List of tuples of user agent and IP that
-                were used during the registration process.
-            auth_provider_id: The SSO IdP the user used, e.g "oidc", "saml",
-                "cas". If any. Note this does not include users registered
-                via a password provider.
-
-        Returns:
-            Enum for how the request should be handled
-        """
-
-        for callback in self._check_registration_for_spam_callbacks:
-            with Measure(
-                self.clock, "{}.{}".format(callback.__module__, callback.__qualname__)
-            ):
-                behaviour = await delay_cancellation(
-                    callback(email_threepid, username, request_info, auth_provider_id)
-                )
-            assert isinstance(behaviour, RegistrationBehaviour)
-            if behaviour != RegistrationBehaviour.ALLOW:
-                return behaviour
-
-        return RegistrationBehaviour.ALLOW
-
-    async def check_media_file_for_spam(
-        self, file_wrapper: ReadableFileWrapper, file_info: FileInfo
-    ) -> Union[Tuple[Codes, dict], Literal["NOT_SPAM"]]:
-        """Checks if a piece of newly uploaded media should be blocked.
-
-        This will be called for local uploads, downloads of remote media, each
-        thumbnail generated for those, and web pages/images used for URL
-        previews.
-
-        Note that care should be taken to not do blocking IO operations in the
-        main thread. For example, to get the contents of a file a module
-        should do::
-
-            async def check_media_file_for_spam(
-                self, file: ReadableFileWrapper, file_info: FileInfo
-            ) -> Union[Codes, Literal["NOT_SPAM"]]:
-                buffer = BytesIO()
-                await file.write_chunks_to(buffer.write)
-
-                if buffer.getvalue() == b"Hello World":
-                    return synapse.module_api.NOT_SPAM
-
-                return Codes.FORBIDDEN
-
-
-        Args:
-            file: An object that allows reading the contents of the media.
-            file_info: Metadata about the file.
-        """
-
-        for callback in self._check_media_file_for_spam_callbacks:
-            with Measure(
-                self.clock, "{}.{}".format(callback.__module__, callback.__qualname__)
-            ):
-                res = await delay_cancellation(callback(file_wrapper, file_info))
-                # Normalize return values to `Codes` or `"NOT_SPAM"`.
-                if res is False or res is self.NOT_SPAM:
-                    continue
-                elif res is True:
-                    return synapse.api.errors.Codes.FORBIDDEN, {}
-                elif isinstance(res, synapse.api.errors.Codes):
-                    return res, {}
-                elif (
-                    isinstance(res, tuple)
-                    and len(res) == 2
-                    and isinstance(res[0], synapse.api.errors.Codes)
-                    and isinstance(res[1], dict)
-                ):
-                    return res
-                else:
-                    logger.warning(
-                        "Module returned invalid value, rejecting media file as spam"
-                    )
-                    return synapse.api.errors.Codes.FORBIDDEN, {}
-
-        return self.NOT_SPAM